Cavitron ultrasonic surgical aspirator (CUSA) compared with conventional pancreatic transection in distal pancreatectomy: study protocol for the randomised controlled CUSA-1 pilot trial

BACKGROUND

Postoperative pancreatic fistula (POPF) remains the most common and serious complication after distal pancreatectomy. Many attempts at lowering fistula rates have led to unrewarding insignificant results as still up to 30% of the patients suffer from clinically relevant POPF. Therefore, the development of new innovative methods and procedures is still a cornerstone of current surgical research.The cavitron ultrasonic surgical aspirator (CUSA) device is a well-known ultrasound-based parenchyma transection method, often used in liver and neurosurgery which has not yet been thoroughly investigated in pancreatic surgery, but the first results seem very promising.

METHODS

The CUSA-1 trial is a randomised controlled pilot trial with two parallel study groups. This single-centre trial is assessor and patient blinded. A total of 60 patients with an indication for open distal pancreatectomy will be intraoperatively randomised after informed consent. The patients will be randomly assigned to either the control group with conventional pancreas transection (scalpel or stapler) or the experimental group, with transection using the CUSA device. The primary safety endpoint of this trial will be postoperative complications ≥grade 3 according to the Clavien-Dindo classification. The primary endpoint to investigate the effect will be the rate of POPF within 30 days postoperatively according to the ISGPS definition. Further perioperative outcomes, including postpancreatectomy haemorrhage, length of hospital stay and mortality will be analysed as secondary endpoints.

DISCUSSION

Based on the available literature, CUSA may have a beneficial effect on POPF occurrence after distal pancreatectomy. The rationale of the CUSA-1 pilot trial is to investigate the safety and feasibility of the CUSA device in elective open distal pancreatectomy compared with conventional dissection methods and gather the first data on the effect on POPF occurrence. This data will lay the groundwork for a future confirmatory multicentre randomised controlled trial.

ETHICS AND DISSEMINATION

The CUSA-1 trial protocol was approved by the ethics committee of the University of Heidelberg (No. S-098/2022). Results will be published in an international peer-reviewed journal and summaries will be provided in lay language to study participants and their relatives.

TRIAL REGISTRATION NUMBER

DRKS00027474.

Robotic versus open partial pancreatoduodenectomy (EUROPA): a randomised controlled stage 2b trial

Background

Open partial pancreatoduodenectomy (OPD) represents the current gold standard of surgical treatment of a wide range of diseases of the pancreatic head but is associated with morbidity in around 40% of cases. Robotic partial pancreatoduodenectomy (RPD) is being used increasingly, yet, no randomised controlled trials (RCTs) of RPD versus OPD have been published, leaving a low level of evidence to support this practice.

Methods

This investigator-initiated, exploratory RCT with two parallel study arms was conducted at a high-volume pancreatic centre in line with IDEAL recommendations (stage 2b). Patients scheduled for elective partial pancreatoduodenectomy (PD) for any indication were randomised (1:1) to RPD or OPD with a centralised web-based tool. The primary endpoint was postoperative cumulative morbidity within 90 days, assessed via the Comprehensive Complication Index (CCI). Biometricians were blinded to the intervention, but patients and surgeons were not. The trial was registered prospectively (DRKS00020407).

Findings

Between June 3, 2020 and February 14, 2022, 81 patients were randomly assigned to RPD (n = 41) or OPD (n = 40), of whom 62 patients (RPD: n = 29, OPD: n = 33) were analysed in the modified intention to treat analysis. Four patients in the OPD group were randomised, but did not undergo surgery in our department and one patient was excluded in the RPD group due to other reason. Nine patients in the RPD group and 3 patients in the OPD were excluded from the primary analysis because they did not undergo PD, but rather underwent other types of surgery. The CCI after 90 days was comparable between groups (RPD: 34.02 ± 23.48 versus OPD: 36.45 ± 27.65, difference in means [95% CI]: -2.42 [-15.55; 10.71], p = 0.713). The RPD group had a higher incidence of grade B/C pancreas-specific complications compared to the OPD group (17 (58.6%) versus 11 (33.3%); difference in rates [95% CI]: 25.3% [1.2%; 49.4%], p = 0.046). The only complication that occurred significantly more often in the RPD than in the OPD group was clinically relevant delayed gastric emptying. Procedure-related and overall hospital costs were significantly higher and duration of surgery was longer in the RPD group. Blood loss did not differ significantly between groups. The intraoperative conversion rate of RPD was 23%. Overall 90-day mortality was 4.8% without significant differences between RPD and OPD.

Interpretation

In the setting of a very high-volume centre, both RPD and OPD can be considered safe techniques. Further confirmatory multicentre RCTs are warranted to uncover potential advantages of RPD in terms of perioperative and long-term outcomes.

Funding

Federal Ministry of Education and Research (BMBF: 01KG2010).

Thoracic Epidural Analgesia Is Not Associated With Improved Survival After Pancreatic Surgery: Long-Term Follow-Up of the Randomized Controlled PAKMAN Trial

BACKGROUND

Perioperative thoracic epidural analgesia (EDA) and patient-controlled intravenous analgesia (PCIA) are common forms of analgesia after pancreatic surgery. Current guidelines recommend EDA over PCIA, and evidence suggests that EDA may improve long-term survival after surgery, especially in cancer patients. The aim of this study was to determine whether perioperative EDA is associated with an improved patient prognosis compared to PCIA in pancreatic surgery.

METHODS

The PAKMAN trial was an adaptive, pragmatic, international, multicenter, randomized controlled superiority trial conducted from June 2015 to October 2017. Three to five years after index surgery a long-term follow-up was performed from October 2020 to April 2021.

RESULTS

For long-term follow-up of survival, 109 patients with EDA were compared to 111 patients with PCIA after partial pancreatoduodenectomy (PD). Long-term follow-up of quality of life (QoL) and pain assessment was available for 40 patients with EDA and 45 patients with PCIA (questionnaire response rate: 94%). Survival analysis revealed that EDA, when compared to PCIA, was not associated with improved overall survival (OS, HR, 1.176, 95% HR-CI, 0.809-1.710, P = .397, n = 220). Likewise, recurrence-free survival did not differ between groups (HR, 1.116, 95% HR-CI, 0.817-1.664, P = .397, n = 220). OS subgroup analysis including only patients with malignancies showed no significant difference between EDA and PCIA (HR, 1.369, 95% HR-CI, 0.932-2.011, P = .109, n = 179). Similar long-term effects on QoL and pain severity were observed in both groups (EDA: n = 40, PCIA: n = 45).

CONCLUSIONS

Results from this long-term follow-up of the PAKMAN randomized controlled trial do not support favoring EDA over PCIA in pancreatic surgery. Until further evidence is available, EDA and PCIA should be considered similar regarding long-term survival.

Late Endograft Migration After Thoracic Endovascular Aortic Repair: A Systematic Review and Meta-analysis

PURPOSE

The objective of this systematic review was to report the cumulative incidence of endograft migration (EM), as well as the morbidity, reintervention rates, and mortality related to EM. This study aimed to provide evidence-based data on patient-relevant sequelae of EM after thoracic endovascular aortic repair (TEVAR) performed using contemporary aortic endografts.

MATERIALS AND METHODS

A systematic electronic search of literature in MEDLINE (via PubMed), Web of Science, and Cochrane Central Register of Controlled Trials was performed. The pooled synthesis of outcomes was performed using the inverse variance method.

RESULTS

Seven prospective non-randomized and 4 retrospective studies, including a total of 1783 patients presenting 70 EMs, were considered for the quantitative analysis. The pooled rate of EM was 4% (95% CI, 2%-7%; range, 0.2%-11%; I2=82%); pooled morbidity rate was 31% (95% CI, 12%-59%; range, 0%-100%; I2=64%) and pooled reintervention rate was 32% (95% CI, 15%-56%; range, 0%-100%; I2=55%). The pooled mortality rate due to EM was 5% (95% CI, 1%-21%; range, 0%-40%; I2=24%).

CONCLUSION

For the first time, this meta-analysis provides pooled reference estimates of EM after TEVAR. Thus, the results hold the potential to further characterize EM after TEVAR. The clinical relevance of EM is underlined by its association with high rates of endoleak-related morbidity, reintervention, and mortality. Close standardized surveillance after TEVAR for early detection of EM and prophylaxis of its sequelae is essential.

The PAncreatic Surgery Composite Endpoint PACE - Development and Validation of a Clinically Relevant Endpoint Requiring Lower Sample Sizes

OBJECTIVE

To provide a composite endpoint in pancreatic surgery.

SUMMARY BACKGROUND DATA

Single endpoints in prospective and randomized studies have become impractical due to their low frequency and the marginal benefit of new interventions.

METHODS

Data from prospective studies were used to develop (n=1273) and validate (n=544) a composite endpoint based on postoperative pancreatic fistula, post-pancreatectomy hemorrhage as well as reoperation and reinterventions. All patients had pancreatectomies of different extents. The association of the developed PAncreatic surgery Composite Endpoint (PACE) with prolonged length of hospital stay (LOS) >75th percentile and mortality was assessed. A single-institution database was used for external validation (n = 2666). Sample size calculations were made for single outcomes and the composite endpoint.

RESULTS

In the internal validation cohort, the PACE demonstrated an AUC of 78.0%, a sensitivity of 90.4% and a specificity of 67.6% in predicting a prolonged LOS. In the external cohort, the AUC was 76.9%, the sensitivity 73.8% and the specificity 80.1%. The 90-day mortality rate was significantly different for patients with a positive versus a negative PACE both in the development and internal validation cohort (5.1% vs 0.9%; P< 0.001), as well as in the external validation cohort (8.5% vs 1.2%, P< 0.001). The PACE enabled sample size reductions of up to 80.5% compared to single outcomes.

CONCLUSION

The PACE performed well in predicting prolonged hospital stays and can be used as a standardized and clinically relevant endpoint for future prospective trials enabling lower sample sizes and therefore improved feasibility compared to single outcome parameters.

A Systematic Review and Illustrative Case Presentation of Low-Grade Myofibroblastic Sarcoma (LGMS) of the Extremities

INTRODUCTION

Low-grade myofibroblastic sarcoma (LGMS) is a rare tumor entity which occurs in the subcutaneous and deep soft tissues; it is less common in the bone with a predilection for the extremities and the head and neck region. As confirming the diagnosis is difficult and treatment strategies are not standardized, we aimed to identify patient and tumor characteristics, and to summarize treatment strategies and their clinical outcomes to guide surgeons.

METHODS

Included were full articles reporting patients with histology of LGMS in the extremities, excluding tumors of the trunk. All patients underwent surgery but with different extend, from marginal to wide resection. Included studies should inform about local recurrence, metastasis, or evidence of disease, depending on the surgical treatment. We conducted a structured search using MEDLINE (via PubMed), Web of Science, EMBASE and Cochrane Central Register of Controlled Trials (CENTRAL) to identify studies on low-grade myofibroblastic sarcoma of the extremities. Study designs like randomized controlled trials, systematic reviews, prospective trials, retrospective studies, and case reports were included. Prospective studies and comparative studies were not available at all. Therefore, meta-analysis was not possible and statistical analysis was purely descriptive.

RESULTS

Of the 789 studies identified from our initial search, 17 studies including 59 cases reported LGMS of the extremities with the surgical treatment and clinical outcome and were therefore analyzed. In addition, we present the rare case and surgical management of a 28-year-old male patient with residual LGMS of the thumb after an initial incomplete resection. The current literature suggests that a wide excision with R0 margins should be considered the standard treatment for LGMS. In cases where surgery leads to significant functional impairment, individual options like free tissue transfer from a donor site have to be considered. Therefore, we also present an illustrative case. For all selected case series and case reports, a high risk of confounding, selection bias, information bias, and reporting bias must be anticipated. Nevertheless, this systematic review provides a comprehensive overview on surgical treatment and clinical outcomes in LGMS surgery of the extremities.

Active learning for extracting surgomic features in robot-assisted minimally invasive esophagectomy: a prospective annotation study

BACKGROUND

With Surgomics, we aim for personalized prediction of the patient's surgical outcome using machine-learning (ML) on multimodal intraoperative data to extract surgomic features as surgical process characteristics. As high-quality annotations by medical experts are crucial, but still a bottleneck, we prospectively investigate active learning (AL) to reduce annotation effort and present automatic recognition of surgomic features.

METHODS

To establish a process for development of surgomic features, ten video-based features related to bleeding, as highly relevant intraoperative complication, were chosen. They comprise the amount of blood and smoke in the surgical field, six instruments, and two anatomic structures. Annotation of selected frames from robot-assisted minimally invasive esophagectomies was performed by at least three independent medical experts. To test whether AL reduces annotation effort, we performed a prospective annotation study comparing AL with equidistant sampling (EQS) for frame selection. Multiple Bayesian ResNet18 architectures were trained on a multicentric dataset, consisting of 22 videos from two centers.

RESULTS

In total, 14,004 frames were tag annotated. A mean F1-score of 0.75 ± 0.16 was achieved for all features. The highest F1-score was achieved for the instruments (mean 0.80 ± 0.17). This result is also reflected in the inter-rater-agreement (1-rater-kappa > 0.82). Compared to EQS, AL showed better recognition results for the instruments with a significant difference in the McNemar test comparing correctness of predictions. Moreover, in contrast to EQS, AL selected more frames of the four less common instruments (1512 vs. 607 frames) and achieved higher F1-scores for common instruments while requiring less training frames.

CONCLUSION

We presented ten surgomic features relevant for bleeding events in esophageal surgery automatically extracted from surgical video using ML. AL showed the potential to reduce annotation effort while keeping ML performance high for selected features. The source code and the trained models are published open source.

Continuous versus interrupted abdominal wall closure after emergency midline laparotomy: CONTINT: a randomized controlled trial [NCT00544583]

BACKGROUND

High-level evidence regarding the technique of abdominal wall closure for patients undergoing emergency midline laparotomy is sparse. Therefore, we conducted a randomized controlled trial (RCT) to evaluate the efficacy and safety of two commonly applied abdominal wall closure strategies after primary emergency midline laparotomy.

METHODS/DESIGN

CONTINT was a multi-center pragmatic open-label exploratory randomized controlled parallel trial. Two different abdominal wall closure strategies in patients undergoing primary midline laparotomy for an emergency surgical intervention with a suspected septic focus in the abdominal cavity were compared: the continuous, all-layer suture and the interrupted suture technique. The primary composite endpoint was burst abdomen within 30 days after surgery or incisional hernia within 12 months. As reliable data on this composite primary endpoint were not available for patients undergoing emergency surgery, it was planned to initially recruit 80 patients and conduct an interim analysis after these had completed the 12 months follow-up.

RESULTS

From August 31, 2009, to June 28, 2012, 124 patients were randomized of whom 119 underwent surgery and were analyzed according to the intention-to-treat (ITT) principal. The primary composite endpoint did not differ between the continuous suture (C: 27.1%) and the interrupted suture group (I: 30.0%). None of the individual components of the primary endpoint (reoperation due to burst abdomen after 30 days (C: 13.5%, I: 15.1%) and reoperation due to incisional hernia (C: 3.0%, I:11.1%)) differed between groups. Time needed for fascial closure was longer in the interrupted suture group (C: 12.8 ± 4.5 min, I: 17.4 ± 6.1 min). BMI was associated with burst abdomen during the first 30 days with an OR of 1.17 (95% CI 1.04-1.32).

CONCLUSION

This RCT showed no difference between continuous suture with slowly absorbable suture versus interrupted rapidly absorbable sutures after primary emergency midline laparotomy in rates of postoperative burst abdomen and incisional hernia after one year. However, the trial was stopped after the interim analysis due to futility as there was no chance to show superiority of one suture technique.

Association of perioperative use of statins, metformin, and aspirin with recurrence after curative liver resection in patients with hepatocellular carcinoma: A propensity score matching analysis

BACKGROUND

Statins, metformin, and aspirin have been reported to reduce the incidence of hepatocellular carcinoma (HCC). However, the effect of their perioperative use on survival outcomes of HCC patients following curative liver resection still remains unclear.

METHOD

Three hundred and fifty three patients with a first diagnosis of HCC who underwent curative liver resection were included. Propensity score matching analysis with a users: nonusers ratio of 1:2 were performed for each of the medications (statins, metformin, and aspirin). Overall survival (OS) and recurrence-free survival (RFS) were evaluated and multivariable Cox proportional hazard analysis was performed.

RESULTS

Sixty two patients received statins, 48 patients used metformin, and 53 patients received aspirin for ≥90 days before surgery. None of the medications improved OS. RFS of statin users was significantly longer than that of nonusers (p = 0.021) in the matched cohort. Users of hydrophilic statins, but not lipophilic ones had a significantly longer RFS than nonusers. Multivariable analysis showed that statin use significantly improved RFS (hazard ratio [HR]: 0.41, 95% confidence interval [CI]: 0.17-0.97, p = 0.044). No difference was seen in RFS between metformin users and nonusers. Among patients with diabetes, RFS was nonsignificantly longer in metformin users than in non-metformin users (84.1% vs. 60.85%, p = 0.069) in the matched cohort. No difference in postoperative RFS was seen between aspirin users and nonusers.

CONCLUSION

Preoperative use of statins in patients with HCC can increase RFS after curative liver resection, but metformin and aspirin were not associated with improved survival. Randomized controlled trials are needed to confirm the findings of the present study.

Drainless robot-assisted minimally invasive oesophagectomy-randomized controlled trial (RESPECT)

BACKGROUND

The purpose of this randomized trial is to evaluate the early removal of postoperative drains after robot-assisted minimally invasive oesophagectomy (RAMIE). Evidence is lacking about feasibility, associated pain, recovery, and morbidity.

METHODS/DESIGN

This is a randomized controlled multicentric trial involving 72 patients undergoing RAMIE. Patients will be allocated into two groups. The "intervention" group consists of 36 patients. In this group, abdominal and chest drains are removed 3 h after the end of surgery in the absence of contraindications. The control group consists of 36 patients with conventional chest drain management. These drains are removed during the further postoperative course according to a standard algorithm. The primary objective is to investigate whether postoperative pain measured by NRS on the second postoperative day can be significantly reduced in the intervention group. Secondary endpoints are the intensity of pain during the first week, analgesic use, number of postoperative chest X-ray and CT scans, interventions, postoperative mobilization (steps per day as measured with an activity tracker), postoperative morbidity and mortality.

DISCUSSION

Until now, there have been no trials investigating different intraoperative chest drain strategies in patients undergoing RAMIE for oesophageal cancer with regard to perioperative complications until discharge. Minimally invasive approaches combined with enhanced recovery after surgery (ERAS) protocols lower morbidity but still include the insertion of chest drains. Reduction and early removal have been proposed after pulmonary surgery but not after RAMIE. The study concept is based on our own experience and the promising current results of the RAMIE procedure. Therefore, the presented randomized controlled trial will provide statistical evidence of the effectiveness and feasibility of the "drainless" RAMIE.

TRIAL REGISTRATION

ClinicalTrials.gov NCT05553795. Registered on 23 September 2022.

Top 10 research priorities in colorectal cancer: results from the Colorectal Cancer Priority-Setting Partnership

BACKGROUND

Colorectal cancer (CRC) is the third most frequent cause of cancer death in the word. Which aspects of research into CRC should be accorded the highest priority remains unclear, because relevant stakeholders, such as patients, nurses, and physicians, played hardly any part in the development of research projects. The goal in forming the CRC Priority-Setting Partnership (PSP) was to bring all relevant stakeholders together to identify and prioritize unresolved research questions regarding the diagnosis, treatment, and follow-up of CRC.

METHODS

The CRC PSP worked in cooperation with the British James Lind Alliance. An initial nationwide survey was conducted, and evidence uncertainties were collected, categorized, summarized, and compared with available evidence from the literature. The as-yet unresolved questions were (provisionally) ranked in a second national wide survey, and at a concluding consensus workshop all stakeholders came together to finalize the rankings in a nominal group process and compile a top 10 list.

RESULTS

In the first survey (34% patients, 51% healthcare professionals, 15% unknown), 1102 submissions were made. After exclusion of duplicates and previously resolved questions, 66 topics were then ranked in the second survey (56% patients, 39% healthcare professionals, 5% unknown). This interim ranking process revealed distinct differences between relatives and healthcare professionals. The final top 10 list compiled at the consensus workshop covers a wide area of research topics.

CONCLUSION

All relevant stakeholders in the CRC PSP worked together to identify and prioritize the top 10 evidence uncertainties. The results give researchers and funding bodies the opportunity to address the most patient-relevant research projects. It is the first detailed description of a PSP in Germany, and the first PSP on CRC care worldwide.

Systematic review and meta-analysis comparing proximal gastrectomy with double-tract-reconstruction and total gastrectomy in gastric and gastroesophageal junction cancer patients: Still no sufficient evidence for clinical decision-making

BACKGROUND

To compare proximal gastrectomy with double-tract reconstruction and total gastrectomy in patients with gastroesophageal junction (AEG II-III) and gastric cancer.

METHODS

We conducted systematic searches in Medline, Web of Science, and Cochrane Library until December 20, 2021 (PROSPERO registration number: CRD42021291500). Risk of bias was assessed using the revised Cochrane risk of bias tool and the ROBINS-I tool, as applicable. Evidence was rated by the Grading of Recommendations Assessment, Development, and Evaluation (GRADE) approach.

RESULTS

One randomized controlled trial (RCT) and 13 non-RCTs with 1,317 patients (715 patients with total gastrectomy and 602 patients with proximal gastrectomy with double-tract reconstruction) were included. Patients treated by total gastrectomy had a significantly higher proportion of advanced cancer stages International Union Against Cancer IB-III (odds ratio: 0.68, 95% confidence interval: 0.51-0.91, P = .01). This heterogeneity biases the observed improved overall survival of patients after proximal gastrectomy with double-tract reconstruction (odds ratio: 0.67, 95% confidence interval: 0.44-1.01, P = .05). Both procedures were comparably efficient regarding perioperative parameters. Postoperative/preoperative bodyweight ratio (mean difference: 3.56, 95% confidence interval: 1.32-5.79, P = .002), postoperative/preoperative serum-hemoglobin ratio (mean difference 3.73, 95% confidence interval: 1.59-5.88, P < .001), and postoperative serum vitamin B₁₂ levels (mean difference 42.46, 95% confidence interval: 6.37-78.55, P = .02) were superior after proximal gastrectomy with double-tract reconstruction, while postoperative/preoperative serum-albumin ratio (mean difference 1.24, 95% confidence interval: -4.76 to 7.24, P = .69) and postoperative/preoperative serum total protein ratio (mean difference 1.12, 95% confidence interval: -2.77 to 5.00, P = .57) were not different. Health-related quality of life data were reported in only 2 studies, which found no significant advantages for proximal gastrectomy with double-tract reconstruction.

CONCLUSION

Proximal gastrectomy with double-tract reconstruction offers advantages in postoperative nutritional parameters compared to total gastrectomy (GRADE: moderate quality of evidence). Oncological effectiveness of proximal gastrectomy with double-tract reconstruction cannot be assessed (GRADE: very low quality of evidence). Further thoroughly planned randomized controlled trials in Western patient cohorts are necessary to improve treatment for gastric cancer patients.

Minimally invasive versus open pancreatic surgery: meta-analysis of randomized clinical trials

BACKGROUND

Widespread implementation of the minimally invasive technique in pancreatic surgery has proven to be challenging. The aim of this study was to compare the perioperative outcomes of minimally invasive (laparoscopic and robotic) pancreatic surgery with open pancreatic surgery using data obtained from RCTs.

METHODS

A literature search was done using Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE, and Web of Science; all available RCTs comparing minimally invasive pancreatic surgery and open pancreatic surgery in adults requiring elective distal pancreatectomy or partial pancreatoduodenectomy were included. Outcomes were mortality rate, general and pancreatic surgery specific morbidity rate, and length of hospital stay.

RESULTS

Six RCTs with 984 patients were included; 99.0 per cent (486) of minimally invasive procedures were performed laparoscopically and 1.0 per cent (five) robotically. In minimally invasive pancreatic surgery, length of hospital stay (-1.3 days, -2 to -0.5, P = 0.001) and intraoperative blood loss (-137 ml, -182 to -92, P < 0.001) were reduced. In the subgroup analysis, reduction in length of hospital stay was only present for minimally invasive distal pancreatectomy (-2 days, -2.3 to -1.7, P < 0.001). A minimally invasive approach showed reductions in surgical site infections (OR 0.4, 0.1 to 0.96, P = 0.040) and intraoperative blood loss (-131 ml, -173 to -89, P < 0.001) with a 75 min longer duration of surgery (42 to 108 min, P < 0.001) only in partial pancreatoduodenectomy. No significant differences were found with regards to mortality rate and postoperative complications.

CONCLUSION

This meta-analysis presents level 1 evidence of reduced length of hospital stay and intraoperative blood loss in minimally invasive pancreatic surgery compared with open pancreatic surgery. Morbidity rate and mortality rate were comparable, but longer duration of surgery in minimally invasive partial pancreatoduodenectomy hints that this technique in partial pancreatoduodenectomy is technically more challenging than in distal pancreatectomy.

Systematic Review on Abdominal Penetrating Atherosclerotic Aortic Ulcers: Outcomes of Endovascular Repair

PURPOSE

To systematically review existing evidence on outcomes of endovascular repair of abdominal atherosclerotic penetrating aortic ulcers (PAUs).

MATERIAL AND METHODS

Cochrane Central Registry of Registered Trials (CENTRAL), MEDLINE (via PubMed), and Web of Science databases were systematically searched. The systematic review was performed according to the Preferred Reporting Items for Systematic Reviews and Meta-Analysis protocol (PRISMA-P 2020). The protocol was registered in the international registry of systematic reviews (PROSPERO CRD42022313404). Studies reporting on technical and clinical outcomes of endovascular PAU repair in 3 or more patients were included. Random effects modeling was used to estimate pooled technical success, survival, reinterventions, and type 1 and type 3 endoleaks. Statistical heterogeneity was assessed using the I² statistic. Pooled results are reported with 95% confidence intervals (CIs). Study quality was assessed using an adapted version of the Modified Coleman Methodology Score.

RESULTS

Sixteen studies including 165 patients with a mean/median age ranging from 64 to 78 years receiving endovascular therapy for PAU between 1997 and 2020 were identified. Pooled technical success was 99.0% (CI: 96.0%-100%). In all, 30-day mortality was 1.0% (CI: 0%-6.0%) with an in-hospital mortality of 1.0% (CI: 0.0%-13.0%). There were no reinterventions, type 1, or type 3 endoleaks at 30 days. Median/mean follow-up ranged from 1 to 33 months. Overall, there were 16 deaths (9.7%), 5 reinterventions (3.3%), 3 type 1 (1.8%), and 1 type 3 endoleak (0.6%) during follow-up. The quality of studies was rated low according to the Modified Coleman score at 43.4 (+/- 8.5) of 85 points.

CONCLUSION

There is low-level evidence on outcomes of endovascular PAU repair. While in the short-term endovascular repair of abdominal PAU seems safe and effective, mid-term and long-term data are lacking. Recommendations with regard to treatment indications and techniques in asymptomatic PAU should be made cautiously.

CLINICAL IMPACT

This systematic review demonstrated that evidence on outcomes of endovascular abdominal PAU repair is limited. While in the short-term endovascular repair of abdominal PAU seems safe and effective, mid-term and long-term data are lacking. In the context of a benign prognosis of asymptomatic PAU and lacking standardization in current reporting, recommendations with regard to treatment indications and techniques in asymptomatic PAUs should be made cautiously.

Middle Segment-Preserving Pancreatectomy to Avoid Pancreatic Insufficiency: Individual Patient Data Analysis of All Published Cases from 2003-2021

Middle segment-preserving pancreatectomy (MPP) can treat multilocular diseases in the pancreatic head and tail while avoiding impairments caused by total pancreatectomy (TP). We conducted a systematic literature review of MPP cases and collected individual patient data (IPD). MPP patients (N = 29) were analyzed and compared to a group of TP patients (N = 14) in terms of clinical baseline characteristics, intraoperative course, and postoperative outcomes. We also conducted a limited survival analysis following MPP. Pancreatic functionality was better preserved following MPP than TP, as new-onset diabetes and exocrine insufficiency each occurred in 29% of MPP patients compared to near-ubiquitous prevalence among TP patients. Nevertheless, POPF Grade B occurred in 54% of MPP patients, a complication avoidable with TP. Longer pancreatic remnants were a prognostic indicator for shorter and less eventful hospital stays with fewer complications, whereas complications of endocrine functionality were associated with older patients. Long-term survival prospects after MPP appeared strong (median up to 110 months), but survival was lower in cases with recurring malignancies and metastases (median < 40 months). This study demonstrates MPP is a feasible treatment alternative to TP for selected cases because it can avoid pancreoprivic impairments, but at the risk of perioperative morbidity.

Central pancreatectomy prevents postoperative diabetes

BACKGROUND

Central pancreatectomy (CP) can be performed as an alternative surgical approach to distal pancreatectomy (DP) in the treatment of benign or low-grade malignant lesions located in the neck and body of the pancreas, aiming to reduce loss of parenchyma and therefore organ failure. The objective of this study was to evaluate the short- and long-term outcome of CP in comparison to DP.

METHODS

Patients who received CP in a large tertiary care pancreatic surgery center between 2001 and 2020 were identified from a prospectively maintained database and compared via propensity score matching with patients receiving DP during the same time period. Perioperative rate of complications and long-term outcome of pancreatic endocrine and exocrine function were evaluated.

RESULTS

One hundred and seven patients undergoing open CP were compared to 107 patients with open DP. No significant difference in rates or severity of most surgical complications could be found including postoperative pancreatic fistula, intraabdominal fluid collection, delayed gastric emptying and wound infection. However, patients receiving CP had a significantly higher risk of grade C postpancreatectomy hemorrhage (PPH) (CP: 10 patients, 9.3% versus DP: 1 patient, 0.9%; p = .0019). Perioperative mortality was comparable. Long-term follow-up of 60 matched pairs revealed significantly less patients with new-onset diabetes after CP (eight patients, 13.3%) compared to DP (22 patients, 36.7%, p = .0056).

CONCLUSION

CP offers an improved endocrine long-term outcome at the expense of a higher risk of PPH without increased perioperative mortality. As evidence on this parenchyma sparing surgical technique is sparse, more prospective data are needed.

Perioperative prothrombin complex concentrate and fibrinogen administration are associated with thrombotic complications after liver transplant

BACKGROUND

Use of intraoperative prothrombin complex concentrates (PCC) and fibrinogen concentrate administration has been linked to thrombotic events. However, it is unknown if its use is associated with thrombotic events after liver transplant.

METHODS AND ANALYSIS

We conducted a post hoc analysis of a prospectively conducted registry database study on patients who underwent liver transplant between 2004 and 2017 at Heidelberg University Hospital, Heidelberg, Germany. Univariate and multivariate analyses were used to determine the association between PCC and fibrinogen concentrate administration and thrombotic complications.

RESULTS

Data from 939 transplantations were included in the analysis. Perioperative PCC or fibrinogen administration was independently associated with the primary composite endpoint Hepatic artery thrombosis (HAT), Portal vein thrombosis (PVT), and inferior vena cava thrombosis [adjusted HR: 2.018 (1.174; 3.468), p = 0.011]. PCC or fibrinogen administration was associated with the secondary endpoints 30-day mortality (OR 4.225, p < 0.001), graft failure (OR 3.093, p < 0.001), intraoperative blood loss, red blood cell concentrate, fresh frozen plasma and platelet transfusion, longer hospitalization, and longer length of stay in intensive care units (ICUs) (all p < 0.001). PCC or fibrinogen administration were not associated with pulmonary embolism, myocardial infarction, stroke, or deep vein thrombosis within 30 days after surgery.

CONCLUSION

A critical review of established strategies in coagulation management during liver transplantation is warranted. Perioperative caregivers should exercise caution when administering coagulation factor concentrate during liver transplant surgery. Prospective randomized controlled trials are needed to establish causality for the relationship between coagulation factors and thrombotic events in liver transplantation. Further studies should be tailored to identify patient subgroups that will likely benefit from PCC or fibrinogen administration.

Generating evidence for diagnosis and therapy of RarE LIVEr disease: the RELIVE Initiative for systematic reviews and meta-analyses

BACKGROUND

Rare liver lesions and diseases have seldomly aroused major interest of researchers. For most guidelines, presumably similar clinical conditions are pooled without detailed investigations of singularities that they present.

MAIN TEXT

A multidisciplinary project aiming to establish evidence-based therapies for rare liver diseases has been founded. A series of systematic reviews and meta-analyses will be the starting point for a structured development of guidelines for rare conditions of the liver affecting pediatric and adult populations. The novel approach will be focusing on case reports and small patient series with distinct rare liver diseases without pooling several presumably acceptably similar conditions. Thus, a vital resource of information will be utilized, which has been largely neglected hitherto.

CONCLUSION

Highly specific recommendations based on highest available evidence will therefore be developed for specific conditions, advancing the individualized medicine approach for the afflicted patients.

Minimally invasivE versus open total GAstrectomy (MEGA): study protocol for a multicentre randomised controlled trial (DRKS00025765)

INTRODUCTION

The only curative treatment for most gastric cancer is radical gastrectomy with D2 lymphadenectomy (LAD). Minimally invasive total gastrectomy (MIG) aims to reduce postoperative morbidity, but its use has not yet been widely established in Western countries. Minimally invasivE versus open total GAstrectomy is the first Western multicentre randomised controlled trial (RCT) to compare postoperative morbidity following MIG vs open total gastrectomy (OG).

METHODS AND ANALYSIS

This superiority multicentre RCT compares MIG (intervention) to OG (control) for oncological total gastrectomy with D2 or D2+LAD. Recruitment is expected to last for 2 years. Inclusion criteria comprise age between 18 and 84 years and planned total gastrectomy after initial diagnosis of gastric carcinoma. Exclusion criteria include Eastern Co-operative Oncology Group (ECOG) performance status >2, tumours requiring extended gastrectomy or less than total gastrectomy, previous abdominal surgery or extensive adhesions seriously complicating MIG, other active oncological disease, advanced stages (T4 or M1), emergency setting and pregnancy.The sample size was calculated at 80 participants per group. The primary endpoint is 30-day postoperative morbidity as measured by the Comprehensive Complications Index. Secondary endpoints include postoperative morbidity and mortality, adherence to a fast-track protocol and patient-reported quality of life (QoL) scores (QoR-15, EUROQOL EuroQol-5 Dimensions-5 Levels (EQ-5D), EORTC QLQ-C30, EORTC QLQ-STO22, activities of daily living and Body Image Scale). Oncological endpoints include rate of R0 resection, lymph node yield, disease-free survival and overall survival at 60-month follow-up.

ETHICS AND DISSEMINATION

Ethical approval has been received by the independent Ethics Committee of the Medical Faculty, University of Heidelberg (S-816/2021) and will be received from each responsible ethics committee for each individual participating centre prior to recruitment. Results will be published open access.

TRIAL REGISTRATION NUMBER

DRKS00025765.

Study protocol of REpeat versus SIngle ShoT Antibiotic prophylaxis in major Abdominal Surgery (RESISTAAS I): a prospective observational study of antibiotic prophylaxis practice for patients undergoing major abdominal surgery

INTRODUCTION

Surgical site infections (SSIs) are among the most common complications after abdominal surgery and develop in approximately 20% of patients. These patients suffer a 12% increase in mortality, underlying the need for strategies reducing SSI. Perioperative antibiotic prophylaxis is paramount for SSI prevention in major abdominal surgery. Yet, intraoperative redosing criteria are subjective and whether patients benefit from it remains unclear.

METHODS AND ANALYSIS

The REpeat versus SIngle ShoT Antibiotic prophylaxis in major Abdominal Surgery (RESISTAAS I) study is a single-centre, prospective, observational study investigating redosing of antibiotic prophylaxis in 300 patients undergoing major abdominal surgery. Adult patients scheduled for major abdominal surgery will be included. Current practice of redosing regarding number and time period will be recorded. Postoperative SSIs, nosocomial infections, clinically relevant infection-associated bacteria, postoperative antibiotic treatment, in addition to other clinical, pharmacological and economical outcomes will be evaluated. Differences between groups will be analysed with analysis of covariance.

ETHICS AND DISSEMINATION

RESISTAAS I will be conducted in accordance with the Declaration of Helsinki and internal, national and international standards of GCP. The Medical Ethics Review Board of Heidelberg University has approved the study prior to initiation (S-404/2021). The study has been registered on 7 February 2022 at German Clinical Trials Register, with identifier DRKS00027892. We plan to disseminate the results of the study in a peer-reviewed journal.

TRIAL REGISTRATION

German Clinical Trials Register (DRKS): DRKS00027892.

Intraoperative visualisation of pancreatic leakage (ViP): study protocol for an IDEAL Stage I Post Market Clinical Study

INTRODUCTION

Pancreatic resections are an important field of surgery worldwide to treat a variety of benign and malignant diseases. Postoperative pancreatic fistula (POPF) remains a frequent and critical complication after partial pancreatectomy and affects up to 50% of patients. POPF increases mortality, prolongs the postoperative hospital stay and is associated with a significant economic burden. Despite various scientific approaches and clinical strategies, it has not yet been possible to develop an effective preventive tool. The SmartPAN indicator is the first surgery-ready medical device for direct visualisation of pancreatic leakage already during the operation. Applied to the surface of pancreatic tissue, it detects sites of biochemical leak via colour reaction, thereby guiding effective closure and potentially mitigating POPF development.

METHODS AND ANALYSIS

The ViP trial is a prospective single-arm, single-centre first in human study to collect data on usability and confirm safety of SmartPAN. A total of 35 patients with planned partial pancreatectomy will be included in the trial with a follow-up of 30 days after the index surgery. Usability endpoints such as adherence to protocol and evaluation by the operating surgeon as well as safety parameters including major intraoperative and postoperative complications, especially POPF development, will be analysed.

ETHICS AND DISSEMINATION

Following the IDEAL-D (Idea, Development, Exploration, Assessment, and Long term study of Device development and surgical innovation) framework of medical device development preclinical in vitro, porcine in vivo, and human ex vivo studies have proven feasibility, efficacy and safety of SmartPAN. After market approval, the ViP trial is the IDEAL Stage I trial to investigate SmartPAN in a clinical setting. The study has been approved by the local ethics committee as the device is used exclusively within its intended purpose. Results will be published in a peer-reviewed journal. The study will provide a basis for a future randomised controlled interventional trial to confirm clinical efficacy of SmartPAN.

TRIAL REGISTRATION NUMBER

German Clinical Trial Register DRKS00027559, registered on 4 March 2022.

Safety and efficacy of TRIANGLE operation applied in pancreatic surgery: a protocol of the systematic review and meta-analysis

BACKGROUND

Pancreatic surgery is regarded as the only curative treatment for pancreatic cancer (PC). As the neoadjuvant therapy is applied widely nowadays, the proportion of patients with PC undergoing surgery also with locally advanced tumour findings has increased accordingly. Especially in these situations, a radical resection of all tumour tissues is challenging. A novel surgical strategy has been introduced recently to achieve this aim, namely the TRIANGLE operation which comprises the radical resection of all nerve and lymphatic tissue between coeliac artery, superior mesenteric artery and mesenteric-portal axis without including extended lymphadenectomy outside this area. Due to currently published studies, Triangle Operation is a safe and feasible procedure. However, this has not been systematically analysed to date. This systematic review and meta-analysis aim to evaluate surgical and postoperative outcomes of Triangle Operation in pancreatic surgery.

METHODS AND ANALYSIS

Pubmed, Web of Science and Cochrane Central Register of Controlled Trials in the Cochrane Library will be searched from inception until 31 December 2022. This study will include all articles comparing Triangle Operation versus non-Triangle Operation in pancreatic surgery to assess outcomes. The primary endpoints will be R0 resection rate and 1-year overall survival. The secondary endpoints will be delayed gastric emptying, postoperative pancreatic fistula, post pancreatectomy haemorrhages and reoperation incidence, overall complications, mortality and 3-year overall survival. The study selection, study quality assessment, data extraction and critical appraisal will be carried out by two reviewers. Inter-reviewer disagreements will be evaluated by discussion with a third reviewer. Besides, a subgroup analysis will be conducted focused on robotic surgery, laparoscopic surgery and open surgery in detail. Additionally, the Grading of Recommendations, Assessment, Development and Evaluations framework will be performed to evaluate the strength of evidence.

ETHICS AND DISSEMINATION

This systematic review and meta-analysis will not require ethical approval. Results will be published in a peer-reviewed scientific journal.

PROSPERO REGISTRATION NUMBER

CRD42021234721.

Immune features of the peritumoral stroma in pancreatic ductal adenocarcinoma

Background

The peritumoral stroma is a hallmark of pancreatic ductal adenocarcinoma (PDA) with implications for disease development, progression and therapy resistance. We systematically investigated immune features of the stroma in PDA patients to identify markers of clinical importance and potential therapeutic targets.

Methods

Tissue and blood samples of 51 PDA patients with clinical and follow-up information were included. Laser Capture Microdissection allowed us to analyze the stromal compartment in particular. Systematic immunohistochemistry, followed by software-based image analysis were conducted. Also, multiplex cytokine analyses (including 50 immune-related molecules) were performed. Functional analyses were performed using patient-derived 3D bioprints. Clinical information was used for survival analyses. Intercompartmental IL9 and IL18 gradients were assessed in matched samples of tumor epithelium, stroma, and serum of patients. Serum levels were compared to an age-matched healthy control group.

Results

Stromal IL9 and IL18 are significantly associated with patient survival. While IL9 is a prognostic favorable marker (p=0.041), IL18 associates with poor patient outcomes (p=0.030). IL9 correlates with an anti-tumoral cytokine network which connects regulation of T helper (Th) 9, Th1 and Th17 cells (all: p<0.05 and r>0.5). IL18 correlates with a Th1-type cytokine phenotype and stromal CXCL12 expression (all: p<0.05 and r>0.5). Further, IL18 associates with a higher level of exhausted T cells. Inhibition of IL18 results in diminished Th1- and Th2-type cytokines. Patients with high stromal IL9 expression have a tumor-to-stroma IL9 gradient directed towards the stroma (p=0.019). Low IL18 expression associates with a tumor-to-stroma IL18 gradient away from the stroma (p=0.007). PDA patients showed higher serum levels of IL9 than healthy controls while serum IL18 levels were significantly lower than in healthy individuals. The stromal immune cell composition is distinct from the tumor epithelium. Stromal density of FoxP3⁺ regulatory T cells showed a tendency towards improved patient survival (p=0.071).

Conclusion

An unexpected high expression of the cytokines IL9 and IL18 at different ends is of significance in the stroma of PDA and relates to opposing patient outcomes. Sub-compartmental cytokine analyses highlight the importance of a differentiated gradient assessment. The findings suggest stromal IL9 and/or IL18 as markers for patient stratification and as potential therapeutic targets. Future steps include investigating e. g. the role of local microbiota as both cytokines are also regulated by microbial compositions.

Finding the best available evidence in pancreatic surgery – the EVIglance randomised controlled trial

Objective

Profound and thorough literature search is a vital element of evidence-based medicine. However, increasing number of publications and limited time make it hard to find the best available evidence. The objective of this randomised controlled trial (RCT) was to demonstrate the superiority of the ISGPS Evidence Map of Pancreatic Surgery (via EVIglance on www.evidencemap.surgery) compared to a conventional literature search via PubMed for answering clinically relevant questions in pancreatic surgery.

Methods

A single-centre, blinded, cross-over RCT including medical students, residents and consultants as participants was performed. Participants conducted literature searches with two predefined PICO (Patient, Intervention, Control, Outcome) questions, one with PubMed and the other with EVIglance. The order of the search tools and the PICO questions were assigned by randomisation. Primary endpoint was time in minutes until a synopsis was made regarding the PICO question. The synopsis was characterised by the direction of the effect and the certainty of evidence. Three times 28 participants were needed to show a minimal difference of 3 minutes at a level of significance of alpha = 1.67%. Furthermore, the correct number of RCTs found by participants that were relevant to answer the PICO question was analysed.

Results

Each 28 medical students, residents and consultants were randomised and analysed. A synopsis for the PICO question was found with PubMed after 10.8 minutes and with EVIglance after 1.7 minutes (95%-CI for difference: 9.9 to 8.3 minutes; p&lt;0.001). EVIglance answered the PICO significantly faster in all groups (medical students, residents and consultants) even after Bonferroni correction. Participants were able to guess both the direction of the effect (95% vs 48%; p&lt;0.001) and the certainty of evidence (99% vs 30%; p&lt;0.001) better with EVIglance than with PubMed. The correct number of relevant RCTs to answer the PICO question was found more often with EVIglance compared to PubMed (99% vs 15%; p&lt;0.001).

Conclusion

Pancreatic surgeons find best available evidence faster via EVIglance on www.evidencemap.surgery. Furthermore, a synopsis made from EVIglance is more concise regarding direction of effect and certainty of evidence. Given the advantages of EVIglance it may be considered the new gold standard for finding best available evidence in pancreatic surgery.

Therapeutic lymphography for persistent chyle leak after pancreatic surgery

BACKGROUND

Chyle leak is a common complication following pancreatic surgery. After failure of conservative treatment, lymphography is one of the last therapeutic options. The objective of this study was to evaluate whether lymphography represents an effective treatment for severe chyle leak (International study Group on Pancreatic Surgery, grade C) after pancreatic surgery.

METHODS

Patients with grade C chyle leak after pancreatic surgery who received transpedal or transnodal therapeutic lymphography between 2010 and 2020 were identified from a prospectively maintained database. Clinical success of the lymphography was evaluated according to percent decrease of drainage output after lymphography (>50% decrease = partial success; >85% decrease = complete success).

RESULTS

Of the 48 patients undergoing lymphography, 23 had a clinically successful lymphography: 14 (29%) showed partial and 9 (19%) complete success. In 25 cases (52%) lymphography did not lead to a significant reduction of chyle leak. Successful lymphography was associated with earlier drain removal and hospital discharge [complete clinical success: 7.1 days (±4.1); partial clinical success: 12 days (±9.1), clinical failure: 19 days (±19) after lymphography; p = 0.006]. No serious adverse events were observed.

CONCLUSION

Therapeutic lymphography is a feasible, safe, and effective option for treating grade C chyle leak after pancreatic surgery.

Clinical outcomes of patients treated on the Heidelberg interprofessional training ward vs. care on a conventional surgical ward: A retrospective cohort study

Interprofessional training wards (IPTW) are a form of interprofessional education enabling trainees of different healthcare professions to work together in teams. Concerns about patient safety are a major barrier to the implementation of IPTWs. The objective of this retrospective study was to analyze patient relevant clinical outcomes on Germany's first IPTW (Heidelberger Interprofessionelle Ausbildungsstation; HIPSTA) in the Department of Surgery at University Hospital Heidelberg in comparison to a conventional surgical ward (CSW). The setting is a large tertiary care center with a focus on major oncological surgery. The endpoints were postoperative complications according to the Dindo-Clavien Classification and a set of patient-safety outcomes. In total, 232 patients treated on HIPSTA were retrospectively compared with 465 patients on a CSW. Baseline characteristics were comparable between groups. No significant difference between rate or severity of overall postoperative complications was observed. In-hospital mortality did not significantly differ between groups. However, the mean length of hospital stay was significantly shorter on HIPSTA. Furthermore, HIPSTA patients had less frequent reoperations. Patient safety in surgical IPTW was not compromised in comparison to a CSW, and there were some areas where significantly better outcomes were identified.

Prognostic relevance of the revised R status definition in pancreatic cancer: meta-analysis

BACKGROUND

The prognostic impact of margin status is reported with conflicting results after pancreatic cancer resection. While some studies validated an uninvolved resection margin (R0) 1 mm or more of tumour clearance, others have failed to show benefit. This systematic review and meta-analysis aimed to investigate the effects of margin definitions on median overall survival (OS).

METHODS

MEDLINE, Web of Science, and the Cochrane Central Register of Controlled Trials were searched for studies reporting associations between resection margins and OS between 2010 and 2021. Data regarding margin status (R0 circumferential resection margin (CRM) negative (CRM-), R0 CRM positive (CRM+), R0 direct, and R1 and OS were extracted. Hazard ratios (HRs) were pooled with a random-effects model. The risk of bias was evaluated with the Quality in Prognosis Studies (QUIPS) tool.

RESULTS

The full texts of 774 studies were screened. In total, 21 studies compromising 6056 patients were included in the final synthesis. In total, 188 (24 per cent) studies were excluded due to missing margin definitions. The R0 (CRM+) rate was 50 per cent (95 per cent confidence interval (c.i.) 0.40 to 0.61) and the R0 (CRM-) rate was 38 per cent (95 per cent c.i. 0.29 to 0.47). R0 (CRM-) resection was independently associated with improved OS compared to combined R1 and R0 (CRM+; HR 1.36, 95 per cent c.i. 1.23 to 1.56).

CONCLUSION

The revised R status was confirmed as an independent prognosticator compared to combined R0 (CRM+) and R1. The limited number of studies, non-standardized pathology protocols, and the varying number of margins assessed hamper comparability.

The TRIANGLE operation for pancreatic head and body cancers: early postoperative outcomes

BACKGROUND

Surgical resection is the mainstay of potential cure for patients with pancreatic cancer, however, local recurrence is frequent. Previously, we have described an extended resection technique for pancreatoduodenectomy aiming at a radical resection of the nerve and lymphatic tissue between celiac artery, superior mesenteric artery and mesenteric-portal axis (TRIANGLE operation). Until now, data on postoperative outcome have not been reported, yet.

METHODS

Patients who underwent either partial (PD) or total pancreatoduodenectomy (TP) applying the TRIANGLE procedure were identified. These cohorts were compared to matched historic cohorts with standard resections.

RESULTS

Overall, 330 patients were analysed (PD_TRIANGLE and PD_STANDARD, each n = 108; TP_TRIANGLE and TP_STANDARD, each n = 57). More lymph nodes were harvested in TRIANGLE compared to standard resection (PD: 27.5 (21-35) versus 31.5 (24-40); P = 0.0187, TP: 33 (28-49) versus 44 (29-53); P = 0.3174) and the rate of tumour positive resections margins, R1(direct), dropped. Duration of operation was significantly longer and blood loss higher. Postoperative mortality and complications did not differ significantly.

CONCLUSION

Pancreatoduodenectomy according to the TRIANGLE protocol can be performed without increased morbidity and mortality at a high-volume centre. Long-term survival and quality of life need to be investigated in prospective clinical trials with adequate sample size.

Tertiary lymphoid structures and their association to immune phenotypes and circulatory IL2 levels in pancreatic ductal adenocarcinoma

Pancreatic ductal adenocarcinoma (PDA) is usually unresponsive to immunotherapeutic approaches. However, tertiary lymphoid structures (TLS) are associated with favorable patient outcomes in PDA. A better understanding of the B cell infiltrate and biological features of TLS formation is needed to further explore their potential and improve patient management. We analyzed tumor tissues (n = 55) and corresponding blood samples (n = 51) from PDA patients by systematical immunohistochemistry and multiplex cytokine measurements. The tissue was compartmentalized in "tumor" and "stroma" and separately examined. Clinical patient information was used to perform survival analyses. We found that the mere number of B cells is not associated with patient survival, but formation of TLS in the peritumoral stroma is a prognostic favorable marker in PDA patients. TLS-positive tissues show a higher density of CD8+ T cells and CD20+ B cells and a higher IL2 level in the peritumoral stroma than tissues without TLS. Compartmental assessment shows that gradients of IL2 expression differ with regard to TLS formation: TLS presence is associated with higher IL2 levels in the stromal than in the tumoral compartment, while no difference is seen in patients without TLS. Focusing on the stroma-to-serum gradient, only patients without TLS show significantly higher IL2 levels in the serum than in stroma. Finally, low circulatory IL2 levels are associated with local TLS formation. Our findings highlight that TLS are prognostic favorable and associated with antitumoral features in the microenvironment of PDA. Also, we propose easily accessible serum IL2 levels as a potential marker for TLS prediction.

Is metabolic syndrome a risk factor in hepatectomy? A meta-analysis with subgroup analysis for histologically confirmed hepatic manifestations

BACKGROUND

Metabolic syndrome (MetS) is a risk factor in surgery. MetS can progress to metabolic (dysfunction)-associated fatty liver disease (MAFLD), a vast-growing etiology of primary liver tumors which are major indications for liver surgery. The aim of this meta-analysis was to investigate the impact of MetS on complications and long-term outcomes after hepatectomy.

METHODS

The protocol for this meta-analysis was registered at PROSPERO prior to data extraction. MEDLINE, Web of Science, and Cochrane Library were searched for publications on liver resections and MetS. Comparative studies were included. Outcomes encompassed postoperative complications, mortality, and long-term oncologic status. Data were pooled as odds ratio (OR) with a random-effects model. Risk of bias was assessed using the Quality in Prognostic Studies tool (QUIPS), and the certainty of the evidence was evaluated with GRADE. Subgroup analyses for patients with histopathologically confirmed non-alcoholic fatty liver disease (NAFLD) versus controls were performed.

RESULTS

The meta-analyses included fifteen comparative studies. Patients with MetS suffered significantly more overall complications (OR 1.55; 95% CI [1.05; 2.29]; p=0.03), major complications (OR 1.97 95% CI [1.13; 3.43]; p=0.02; I²=62%), postoperative hemorrhages (OR 1.76; 95% CI [1.23; 2.50]; p=0.01) and infections (OR 1.63; 95% CI [1.03; 2.57]; p=0.04). There were no significant differences in mortality, recurrence, 1- or 5-year overall or recurrence-free survivals. Patients with histologically confirmed NAFLD did not have significantly more overall complications; however, PHLF rates were increased (OR 4.87; 95% CI [1.22; 19.47]; p=0.04). Recurrence and survival outcomes did not differ significantly. The certainty of the evidence for each outcome ranged from low to very low.

CONCLUSION

Patients with MetS that undergo liver surgery suffer more complications, such as postoperative hemorrhage and infection but not liver-specific complications-PHLF and biliary leakage. Histologically confirmed NAFLD is associated with significantly higher PHLF rates, yet, survivals of these patients are similar to patients without the MetS. Further studies should focus on identifying the tipping point for increased risk in patients with MetS-associated liver disease, as well as reliable markers of MAFLD stages and early markers of PHLF.

TRIAL REGISTRATION

PROSPERO Nr: CRD42021253768.

Treatment of Postoperative Lymphatic Leakage Applying Transpedal Lymphangiography - Experience in 355 Consecutive Patients

PURPOSE

 Report of experience from a single institution in treating postoperative lymphatic leakage (PLL) applying conventional transpedal lymphangiography (TL).

MATERIALS AND METHODS

 453 patients with the initial diagnosis of PLL receiving TL between 03/1993 and 09/2018 were identified in the database. Only patients with confirmed PLL were included in the study. The technical success, safety, and treatment success of TL were evaluated. Independent predictors of TL treatment failure were examined using univariate and multivariate logistic regression analysis.

RESULTS

 355 consecutive patients (218 men, 137 women; median age of 62 years) who underwent TL for PLL (e. g., chylothorax) after ineffective conservative treatment were included. The median time between causal surgery and TL was 27 days. The median technical success rate of TL was 88.5 %, with a median volume of Lipiodol of 10.0 ml. No complication of TL was recorded. Three groups were defined according to the different clinical courses: group A (41/355, 11.5 %) - TL with technical failure; group B (258/355, 72.7 %) - "therapeutic" TL alone with technical success; and group C (56/355, 15.8 %) - "diagnostic" TL with simultaneously invasive treatment (incl. surgical revision and percutaneous sclerotherapy). Treatment success rate and median time to treatment success were higher in group C than in group B, but without significant differences (64.3 % vs. 61.6 %, p = 0.710; six vs. five days, p = 0.065). Univariate and multivariate logistic regression analyses for group B confirmed drainage volume (> 500 ml/d) and Lipiodol extravasation as independent predictors of TL clinical failure (odds ratios [ORs] of 2.128 and 2.372 [p = 0.005 and p = 0.003, respectively]).

CONCLUSION

 TL is technically reliable, safe, and effective in treating PLL. When conservative treatment fails, TL can be regarded as the next treatment option.

KEY POINTS

  · TL is technically reliable, safe, and effective for treating PLL.. · When conservative treatment fails, TL can be regarded as the next treatment option.. · Drainage volume > 500 ml/day is an independent predictor of clinical failure after TL.. · Lipiodol extravasation is an independent predictor of clinical failure after TL..

CITATION FORMAT

· Pan F, Richter GM, Do TD et al. Treatment of Postoperative Lymphatic Leakage Applying Transpedal Lymphangiography - Experience in 355 Consecutive Patients. Fortschr Röntgenstr 2022; DOI: 10.1055/a-1717-2467.

Inflammasome Targeted Therapy as Novel Treatment Option for Aortic Aneurysms and Dissections: A Systematic Review of the Preclinical Evidence

Both aortic aneurysm and dissection are life threatening pathologies. In the lack of a conservative medical treatment, the only therapy consists of modifying cardiovascular risk factors and either surgical or endovascular treatment. Like many other cardiovascular diseases, in particular atherosclerosis, aortic aneurysm and dissection have a strong inflammatory phenotype. Inflammasomes are part of the innate immune system. Upon stimulation they form multi protein complexes resulting mainly in activation of interleukin-1β and other cytokines. Considering the gathering evidence, that inflammasomes are decisively involved in the emergence and progression of aortic diseases, inflammasome targeted therapy provides a promising new treatment approach. A systematic review following the PRISMA guidelines on the current preclinical data regarding the potential role of inflammasome targeted drug therapy as novel treatment option for aortic aneurysms and dissections was performed. Included were all rodent models of aortic disease (aortic aneurysm and dissection) evaluating a drug therapy with direct or indirect inhibition of inflammasomes and a suitable control group with the use of the same aortic model without the inflammasome targeted therapy. Primary and secondary outcomes were incidence of aortic disease, aortic rupture, aortic related death, and the maximum aortic diameter. The literature search of MEDLINE (via PubMed), the Web of Science, EMBASE and the Cochrane Central Registry of Registered Trials (CENTRAL) resulted in 8,137 hits. Of these, four studies met the inclusion criteria and were therefore eligible for data analysis. In all of them, targeting of the NOD-, LRR- and pyrin domain-containing protein 3 (NLRP3) inflammasome effectively reduced the incidence of aortic disease and aortic rupture, and additionally reduced destruction of the aortic wall. Treatment strategies aiming at other inflammasomes could not be identified. In conclusion, inflammasome targeted therapies, more precisely targeting the NLRP3 inflammasome, have shown promising results in rodent models and deserve further investigation in preclinical research to potentially translate them into clinical research for the treatment of human patients with aortic disease. Regarding other inflammasomes, more preclinical research is needed to investigate their role in the pathophysiology of aortic disease.

Protocol Registration: PROSPERO 2021 CRD42021279893, https://www.crd.york.ac.uk/prospero/display_record.php?ID=CRD42021279893

Antecolic versus retrocolic reconstruction after partial pancreaticoduodenectomy

BACKGROUND

Pancreatic cancer remains one of the five leading causes of cancer deaths in industrialised nations. For adenocarcinomas in the head of the gland and premalignant lesions, partial pancreaticoduodenectomy represents the standard treatment for resectable tumours. The gastro- or duodenojejunostomy after partial pancreaticoduodenectomy can be reestablished via either an antecolic or retrocolic route. The debate about the more favourable technique for bowel reconstruction is ongoing.

OBJECTIVES

To compare the effectiveness and safety of antecolic and retrocolic gastro- or duodenojejunostomy after partial pancreaticoduodenectomy.

SEARCH METHODS

In this updated version, we conducted a systematic literature search up to 6 July 2021 to identify all randomised controlled trials (RCTs) in the Cochrane Central Register of Controlled Trials (CENTRAL), the Cochrane Library 2021, Issue 6, MEDLINE (1946 to 6 July 2021), and Embase (1974 to 6 July 2021). We applied no language restrictions. We handsearched reference lists of identified trials to identify further relevant trials, and searched the trial registries clinicaltrials.govand World Health Organization International Clinical Trials Registry Platform for ongoing trials.

SELECTION CRITERIA

We considered all RCTs comparing antecolic with retrocolic reconstruction of bowel continuity after partial pancreaticoduodenectomy for any given indication to be eligible.

DATA COLLECTION AND ANALYSIS

Two review authors independently screened the identified references and extracted data from the included trials. The same two review authors independently assessed risk of bias of included trials, according to standard Cochrane methodology. We used a random-effects model to pool the results of the individual trials in a meta-analysis. We used odds ratios (OR) to compare binary outcomes and mean differences (MD) for continuous outcomes.

MAIN RESULTS

Of a total of 287 citations identified by the systematic literature search, we included eight randomised controlled trials (reported in 11 publications), with a total of 818 participants. There was high risk of bias in all of the trials in regard to blinding of participants and/or outcome assessors and unclear risk for selective reporting in six of the trials. There was little or no difference in the frequency of delayed gastric emptying (OR 0.67; 95% confidence interval (CI) 0.41 to 1.09; eight trials, 818 participants, low-certainty evidence) with relevant heterogeneity between trials (I2=40%). There was little or no difference in postoperative mortality (risk difference (RD) -0.00; 95% CI -0.02 to 0.01; eight trials, 818 participants, high-certainty evidence); postoperative pancreatic fistula (OR 1.01; 95% CI 0.73 to 1.40; eight trials, 818 participants, low-certainty evidence); postoperative haemorrhage (OR 0.87; 95% CI 0.47 to 1.59; six trials, 742 participants, low-certainty evidence); intra-abdominal abscess (OR 1.11; 95% CI 0.71 to 1.74; seven trials, 788 participants, low-certainty evidence); bile leakage (OR 0.82; 95% CI 0.35 to 1.91; seven trials, 606 participants, low-certainty evidence); reoperation rate (OR 0.68; 95% CI 0.34 to 1.36; five trials, 682 participants, low-certainty evidence); and length of hospital stay (MD -0.21; 95% CI -1.41 to 0.99; eight trials, 818 participants, low-certainty evidence). Only one trial reported quality of life, on a subgroup of 73 participants, also without a relevant difference between the two groups at any time point. The overall certainty of the evidence was low to moderate, due to some degree of heterogeneity, inconsistency and risk of bias in the included trials.

AUTHORS' CONCLUSIONS

There was low- to moderate-certainty evidence suggesting that antecolic reconstruction after partial pancreaticoduodenectomy results in little to no difference in morbidity, mortality, length of hospital stay, or quality of life. Due to heterogeneity in definitions of the endpoints between trials, and differences in postoperative management, future research should be based on clearly defined endpoints and standardised perioperative management, to potentially elucidate differences between these two procedures. Novel strategies should be evaluated for prophylaxis and treatment of common complications, such as delayed gastric emptying.

Intraoperative Fractions of Inspiratory Oxygen Are Associated With Recurrence-Free Survival After Elective Cancer Surgery

Background: Choice of the fraction of inspiratory oxygen (FiO₂) is controversial. The objective of this analysis was to evaluate whether intraoperative FiO₂ was associated with recurrence-free survival after elective cancer surgery.

Methods and Analysis: In this single-center, retrospective study, we analyzed 1,084 patients undergoing elective resection of pancreatic (n = 652), colorectal (n = 405), or hepatic cancer (n = 27) at Heidelberg University Hospital between 2009 and 2016. Intraoperative mean FiO₂ values were calculated. For unstratified analyses, the study cohort was equally divided into a low- and a high-FiO₂ group. For cancer-stratified analyses, this division was done within cancer-strata. The primary outcome measure was recurrence-free survival until the last known follow-up. Groups were compared using Kaplan–Meier analysis. A stratified log rank test was used to control for different FiO₂ levels and survival times between the cancer strata. Cox-regression analyses were used to control for covariates. Sepsis, reoperations, surgical-site infections, and cardiovascular events during hospital stay and overall survival were secondary outcomes.

Results: Median FiO₂ was 40.9% (Q1–Q3, 38.3–42.9) in the low vs. 50.4% (Q1–Q3, 47.4–54.7) in the high-FiO₂ group. Median follow-up was 3.28 (Q1–Q3, 1.68–4.97) years. Recurrence-free survival was considerable higher in the high-FiO₂ group (p < 0.001). This effect was also confirmed when stratified for the different tumor entities (p = 0.007). In colorectal cancer surgery, increased FiO₂ was independently associated with increased recurrence-free survival. The hazard for the primary outcome decreased by 3.5% with every 1% increase in FiO₂. The effect was not seen in pancreatic cancer surgery and we did not find differences in any of the secondary endpoints.

Conclusions: Until definite evidence from large-scale trials is available and in the absence of relevant clinical conditions warranting specific FiO₂ values, perioperative care givers should aim for an intraoperative FiO₂ of 50% in abdominal cancer surgery as this might benefit oncological outcomes.

Peripheral blood and tissue assessment highlights differential tumor-circulatory gradients of IL2 and MIF with prognostic significance in resectable pancreatic ductal adenocarcinoma

Various reports have pointed out the potential of cytokines as diagnostic and prognostic biomarkers for pancreatic ductal adenocarcinoma (PDA). Nonetheless, the evidence is contradictory and the role of chronic inflammation and relationship between circulatory and corresponding tumoral cytokine levels remain elusive. Utilizing a broad array of cytokines, we identified two opposing parameters: serum levels of interleukin 2 (IL2) and macrophage migration inhibitory factor (MIF) are diagnostic and prognostic factors. While low IL2 levels are associated with PDA, they also relate to a favorable prognosis of patients. In contrast, high MIF levels are associated with PDA and simultaneously related to an unfavorable outcome. MIF levels are associated with the intratumoral density of M2 macrophages (CD163⁺). Focusing on the tumor-to-serum gradient, we unveiled a different pattern of compartmental cytokine expression between IL2 and MIF. Our findings indicate that an extra-tumoral source of IL2 exists in PDA patients leading to increased detectability in the circulatory system. In case of MIF, the tumor microenvironment is presumably the main site of production and thereby reflected by serum measurements. Taken together, our study describes IL2 and MIF levels as biomarker candidates for diagnosis and prognosis of PDA, highlighting the need for compartmental cytokine analyses. From the perspective of tumor immunobiology, we identify multiple inflammatory states (proposed as types I-III) and see that systemic chronic dysregulation, independent of tumor microenvironment, can be measured and is a possible tool for stratification. Thus, direct correlation of local cytokine levels to peripheral blood levels needs to be regarded with caution.

Systematic reviews in surgery-recommendations from the Study Center of the German Society of Surgery

Background

Systematic reviews are an important tool of evidence-based surgery. Surgical systematic reviews and trials, however, require a special methodological approach.

Purpose

This article provides recommendations for conducting state-of-the-art systematic reviews in surgery with or without meta-analysis.

Conclusions

For systematic reviews in surgery, MEDLINE (via PubMed), Web of Science, and Cochrane Central Register of Controlled Trials (CENTRAL) should be searched. Critical appraisal is at the core of every surgical systematic review, with information on blinding, industry involvement, surgical experience, and standardisation of surgical technique holding special importance. Due to clinical heterogeneity among surgical trials, the random-effects model should be used as a default. In the experience of the Study Center of the German Society of Surgery, adherence to these recommendations yields high-quality surgical systematic reviews.

Bowel dysfunction after elective spinal surgery: etiology, diagnostics and management based on the medical literature and experience in a university hospital

BACKGROUND

Bowel dysfunction after spinal surgery is often underestimated and if not treated in a timely manner can lead to undesirable surgical interventions or fatal complications. The current medical literature primarily focuses on bowel dysfunction as a result of spinal injury.

OBJECTIVE

The purpose of this review is to explore this topic in evaluating current evidence regarding the causes of acute bowel dysfunction after elective spinal surgery, primarily the thoracolumbar spine. Since available evidence for recommendations of treatment is scarce, an interdisciplinary management approach for treatment of bowel dysfunction following spinal surgery is also formulated.

MATERIAL AND METHODS

An extensive literature search was carried out on PubMed. Keywords that were used in the search included bowel dysfunction, obstruction, postoperative ileus, spinal surgery, spinal fusion, constipation, opioid-induced constipation, colonic pseudo-obstruction, ischemic colitis, immobility-induced bowel changes, epidural anesthesia and diet. Relevant studies were chosen and included in the review. The treatment approach used in the spine center of a university hospital was included.

RESULTS

Current research mainly focuses on investigating the nature and symptomatology of chronic bowel dysfunction after spinal cord injury. Emphasis on the acute phase of bowel dysfunction in patients after elective spinal surgery is lacking. The comorbidities that exacerbate bowel dysfunction postoperatively are well-defined. There has been refinement and expansion of the pharmacological and nonpharmacological treatment that could be implemented. Enough evidence exists to provide sufficient care.

CONCLUSION

Management of acute bowel dysfunction after spinal surgery requires a comprehensive and individualized approach, encompassing comorbidities, behavioral changes, medications and surgery. Close supervision and timely treatment could minimize further complications. Research is required to identify patients who are at a higher risk of developing bowel dysfunction after specific spinal procedures.

Feasibility, effectiveness, and safety of endoscopic vacuum therapy for intrathoracic anastomotic leakage following transthoracic esophageal resection

Background

Anastomotic leakage (AL) in the upper gastrointestinal (GI) tract is associated with high morbidity and mortality rates. Especially intrathoracic anastomotic leakage leads to life-threatening complications. Endoscopic vacuum therapy (EVT) for anastomotic leakage after transthoracic esophageal resection represents a novel concept. However, sound clinical data are still scarce. This retrospective, single-center study aimed to evaluate the feasibility, effectiveness, and safety of EVT for intrathoracic anastomotic leakage following abdomino-thoracic esophageal resection.

Methods

From March 2014 to September 2019 259 consecutive patients underwent elective transthoracic esophageal resection. 72 patients (27.8%) suffered from AL. The overall collective in-hospital mortality rate was 3.9% (n = 10). Data from those who underwent treatment with EVT were included.

Results

Fifty-five patients were treated with EVT. Successful closure was achieved in 89.1% (n = 49) by EVT only. The EVT-associated complication rate was 5.4% (n = 3): bleeding occurred in one patient, while minor sedation-related complications were observed in two patients. The median number of EVT procedures per patient was 3. The procedures were performed at intervals of 3–5 days, with a 14-day median duration of therapy. The mortality rate of patients with AL was 7.2% (n = 4). Despite successfully terminated EVT, three patients died because of multiple organ failure, acute respiratory distress syndrome, and urosepsis (5.4%). One patient (1.8%) died during EVT due to cardiac arrest.

Conclusions

EVT is a safe and effective approach for intrathoracic anastomotic leakages following abdomino-thoracic esophageal resections. It offers a high leakage-closure rate and the potential to lower leakage-related mortalities.

Trial registration: This trial was registered and approved by the Institutional Ethics Committee of the University of Heidelberg on 16.04.2014 (Registration Number: S-635/2013).

Evaluation of robotic versus open partial pancreatoduodenectomy-study protocol for a randomised controlled pilot trial (EUROPA, DRKS00020407)

Background

Partial pancreatoduodenectomy (PD) is the indicated surgical procedure for a wide range of benign and malignant diseases of the pancreatic head and distal bile duct and offers the only potential cure for pancreatic head cancer. The current gold standard, open PD (OPD) performed via laparotomy, is associated with morbidity in around 40% of cases, even at specialised centres. Robotic PD (RPD) might offer a viable alternative to OPD and has been shown to be feasible. Encouraging perioperative results have been reported for RPD in a number of small, non-randomised studies. However, since those studies showed a considerable risk of bias, a thorough comparison of RPD with OPD is warranted.

Methods

The EUROPA (EvalUation of RObotic partial PAncreatoduodenectomy) trial is designed as a randomised controlled unblinded exploratory surgical trial with two parallel study groups. A total of 80 patients scheduled for elective PD will be randomised after giving written informed consent. Patients with borderline or non-resectable carcinoma of the pancreatic head as defined by the National Comprehensive Cancer Network guidelines, distant metastases or an American Society of Anaesthesiologists (ASA) score > III will be excluded. The experimental intervention, RPD, will be compared with the control intervention, OPD. An intraoperative dropout of approximately eight patients per group is expected because they may receive another type of surgical procedure than planned. Overall, 64 patients need to be analysed. The primary endpoint of the trial is overall postoperative morbidity within 90 days after index operation, measured using the Comprehensive Complication Index (CCI). The secondary endpoints include the feasibility of recruitment and assessment of clinical, oncological and safety parameters and quality of life and cost-effectiveness.

Discussion

The EUROPA trial is the first randomised controlled trial comparing RPD with OPD. Differences in postoperative morbidity will be evaluated to design a future multicentre confirmatory efficacy trial.

Trial registration

German Clinical Trial Register DRKS00020407. Registered on 9 March 2020

Gastrointestinal Complications After Pancreatoduodenectomy With Epidural vs Patient-Controlled Intravenous Analgesia: A Randomized Clinical Trial

Importance

Morbidity is still high in pancreatic surgery, driven mainly by gastrointestinal complications such as pancreatic fistula. Perioperative thoracic epidural analgesia (EDA) and patient-controlled intravenous analgesia (PCIA) are frequently used for pain control after pancreatic surgery. Evidence from a post hoc analysis suggests that PCIA is associated with fewer gastrointestinal complications.

Objective

To determine whether postoperative PCIA decreases the occurrence of gastrointestinal complications after pancreatic surgery compared with EDA.

Design, Setting, and Participants

In this adaptive, pragmatic, international, multicenter, superiority randomized clinical trial conducted from June 30, 2015, to October 1, 2017, 371 patients at 9 European pancreatic surgery centers who were scheduled for elective pancreatoduodenectomy were randomized to receive PCIA (n = 185) or EDA (n = 186); 248 patients (124 in each group) were analyzed. Data were analyzed from February 22 to April 25, 2019, using modified intention to treat and per protocol.

Interventions

Patients in the PCIA group received general anesthesia and postoperative PCIA with intravenous opioids with the help of a patient-controlled analgesia device. In the EDA group, patients received general anesthesia and intraoperative and postoperative EDA.

Main Outcomes and Measures

The primary end point was a composite of pancreatic fistula, bile leakage, delayed gastric emptying, gastrointestinal bleeding, or postoperative ileus within 30 days after surgery. Secondary end points included 30-day mortality, other complications, postoperative pain levels, intraoperative or postoperative use of vasopressor therapy, and fluid substitution.

Results

Among the 248 patients analyzed (147 men; mean [SD] age, 64.9 [10.7] years), the primary composite end point did not differ between the PCIA group (61 [49.2%]) and EDA group (57 [46.0%]) (odds ratio, 1.17; 95% CI, 0.71-1.95 P = .54). Neither individual components of the primary end point nor 30-day mortality, postoperative pain levels, or intraoperative and postoperative substitution of fluids differed significantly between groups. Patients receiving EDA gained more weight by postoperative day 4 than patients receiving PCIA (mean [SD], 4.6 [3.8] vs 3.4 [3.6] kg; P = .03) and received more vasopressors (46 [37.1%] vs 31 [25.0%]; P = .04). Failure of EDA occurred in 23 patients (18.5%).

Conclusions and Relevance

This study found that the choice between PCIA and EDA for pain control after pancreatic surgery should not be based on concerns regarding gastrointestinal complications because the 2 procedures are comparable with regard to effectiveness and safety. However, EDA was associated with several shortcomings.

Trial Registration

German Clinical Trials Register: DRKS00007784.

Continuous wound infiltration versus epidural analgesia for midline abdominal incisions - a randomized-controlled pilot trial (Painless-Pilot trial; DRKS Number: DRKS00008023)

OBJECTIVES

To test the feasibility of a randomized controlled study design comparing epidural analgesia (EDA) with continuous wound infiltration (CWI) in respect to postoperative complications and mobility to design a future multicentre randomized controlled trial.

DESIGN, SETTING, PARTICIPANTS

CWI has been developed to address drawbacks of EDA. Previous studies have established the equivalent analgesic potential of CWI compared to EDA. This is a single centre, non-blinded pilot randomized controlled trial at a tertiary surgical centre. Patients undergoing elective non-colorectal surgery via a midline laparotomy were randomized to EDA or CWI. Endpoints included recruitment, feasibility of assessing postoperative mobility with a pedometer and morbidity. No primary endpoint was defined and all analyses were explorative.

INTERVENTIONS

CWI with local anaesthetics (experimental group) vs. thoracic EDA (control).

RESULTS

Of 846 patients screened within 14 months, 71 were randomized and 62 (31 per group) included in the intention-to-treat analysis. Mobility was assessed in 44 of 62 patients and revealed no differences within the first 3 postoperative days. Overall morbidity did not differ between the two groups (measured via the comprehensive complication index). Median pain scores at rest were comparable between the two groups, while EDA was superior in pain treatment during movement on the first, but not on the second and third postoperative day. Duration of preoperative induction of anaesthesia was shorter with CWI than with EDA. Of 17 serious adverse events, 3 were potentially related to EDA, while none was related to CWI.

CONCLUSION

This trial confirmed the feasibility of a randomized trial design to compare CWI and EDA regarding morbidity. Improvements in the education and training of team members are necessary to improve recruitment.

TRIAL REGISTRATION

DRKS00008023.

Abstract C02: Establishment of a human PDAC explant culture model for treatment prediction and characterization of the tumor microenvironment

Introduction: Pancreatic ductal adenocarcinoma (PDAC) is the fourth most common cause of death from cancer, with a 5-year survival of less than 8%. To date, the therapeutic approaches are chemotherapy regimens. Despite promising data from various preclinical models, new immunotherapeutic agents like checkpoint inhibitors (CPI), vaccines, oncolytic viruses, or TGFβ inhibitors do not show a benefit in the overall survival of patients. Thus, especially in PDAC and in respect to the immune system, there is an urgent need for sufficient preclinical systems that can mirror a human patient scenario. Therefore, we developed a human-based pipeline of whole explant tissue culture using PDAC to predict responses of the tumor to different types of treatments in a personalized manner.

Material and Methods: Human cancer tissue is taken into culture after surgery for several days. We tested different timings and technical variations (e.g., thickness of explants, medium changing protocols) to find superior conditions for tissue viability. In culture, the explants can be treated with (pre-) clinical-grade drugs and subsequently processed for quality controls via evaluation of the tissue integrity (on H&E slides) and cytokine stability. Also, histologic analyzes (e.g., cancer cells, T cells, B cells, macrophages) as well as multiplex cytokine analyzes are carried out. This combined approach enables us to study the impact of various drugs on the tissue in terms of tumor cell death, changes in the infiltration and activation of lymphocytes and macrophage polarization, etc. Results In vivo features of the tissue and the matrix architecture as well as the cytokine signatures are well maintained in the explants. Our model is reproducible among different explants of the same tissue in terms of infiltrating cells and cytokine expression. In addition, we were able to achieve an overview of the cytokine signature of PDAC in patients and to distinguish between clusters of patients by identifying different immune landscapes, for example, immunologically hot and cold subtypes.

Discussion: Our model is usable as a predictive system for the response of PDAC to different types of treatments and seems to be a reliable and sufficient preclinical extension alternative to mouse models, single-cell experiments, or organoid models. The whole context of the tissue is from human origin and we aim to expand our platform for multiscreening of drug responses for personalized decision-making. Furthermore, we described the tumor microenvironment in detail, unraveling the complex cytokine signature of PDAC, and subsequently identified different clusters of immune landscapes, which may be of prognostic value.

Citation Format: Azaz Ahmed, Dyke Ferber, Meggy Suarez-Carmona, Bénédicte Lenoir, Rosa Klotz, Thilo Hackert, Nathalia Giese, Inka Zörnig, Dirk Jäger, Niels Halama. Establishment of a human PDAC explant culture model for treatment prediction and characterization of the tumor microenvironment [abstract]. In: Proceedings of the AACR Special Conference on Pancreatic Cancer: Advances in Science and Clinical Care; 2019 Sept 6-9; Boston, MA. Philadelphia (PA): AACR; Cancer Res 2019;79(24 Suppl):Abstract nr C02.

Percutaneous versus surgical strategy for tracheostomy: a systematic review and meta-analysis of perioperative and postoperative complications

PURPOSE

Tracheostomy is one of the most frequently performed procedures in intensive care medicine. The two main approaches are open surgical tracheostomy (ST) and percutaneous dilatational tracheostomy (PDT). This systematic review summarizes and analyzes the existing evidence regarding perioperative and postoperative parameters of safety.

METHODS

A systematic literature search was conducted in the Cochrane Library, EMBASE, LILACS, and MEDLINE to identify all randomized controlled trials (RCTs) comparing complications of ST and PDT and to define the strategy with the lower risk of potentially life-threatening events. Risk of bias was assessed using the criteria outlined in the Cochrane Handbook.

RESULTS

Twenty-four citations comprising 1795 procedures (PDT: n = 926; ST: n = 869) were found suitable for systematic review. No significant difference in the risk of a potentially life-threatening event (risk difference (RD) 0.01, 95% CI - 0.03 to 0.05, P = 0.62, I ² = 47%) was found between PDT and ST. There was no difference in mortality (RD - 0.00, 95% CI - 0.01 to 0.01, P = 0.88, I ² = 0%). An increased rate of technical difficulties was shown for PDT (RD 0.04, 95% CI 0.01, 0.08, P = 0.01, I ² = 60%). Stomal infection occurred more often with ST (RD - 0.05, 95% CI - 0.08 to - 0.02, P = 0.003, I ² = 60%). Both techniques can be safely performed on the ICU. Meta-analysis of the duration of procedure was not possible owing to high heterogeneity (I ² = 99%).

CONCLUSION

ST and PDT are safe techniques with low incidence of complications. Both techniques can be performed successfully in an ICU setting. ST can be performed on every patient whereas PDT is restricted by several contraindications like abnormal anatomy, previous surgery, coagulopathies, or difficult airway of the patient.

SYSTEMATIC REVIEW REGISTRATION

PROSPERO CRD42015021967.

Antecolic versus retrocolic reconstruction after partial pancreaticoduodenectomy

BACKGROUND

Pancreatic cancer remains one of the five leading causes of cancer deaths in industrialized nations. For adenocarcinomas in the head of the gland and premalignant lesions, partial pancreaticoduodenectomy represents the standard treatment for resectable tumours. The gastro- or duodenojejunostomy after partial pancreaticoduodenectomy can be reestablished via either an antecolic or a retrocolic route. The debate about the more favourable technique for bowel reconstruction is ongoing.

OBJECTIVES

To compare the effectiveness and safety of antecolic and retrocolic gastro- or duodenojejunostomy after partial pancreaticoduodenectomy.

SEARCH METHODS

We conducted a systematic literature search on 29 September 2015 to identify all randomised controlled trials in the Cochrane Central Register of Controlled Trials (CENTRAL), The Cochrane Library 2015, issue 9, MEDLINE (1946 to September 2015), and EMBASE (1974 to September 2015). We applied no language restrictions. We handsearched reference lists of identified trials to identify further relevant trials, and searched the trial registry clinicaltrials.gov for ongoing trials.

SELECTION CRITERIA

We considered all randomised controlled trials that compared antecolic versus retrocolic reconstruction of bowel continuity after partial pancreaticoduodenectomy for any given indication to be eligible.

DATA COLLECTION AND ANALYSIS

Two review authors independently screened the identified references and extracted data from the included trials. The same two review authors independently assessed risk of bias of included trials, according to standard Cochrane methodology. We used a random-effects model to pool the results of the individual trials in a meta-analysis. We used odds ratios to compare binary outcomes and mean differences for continuous outcomes.

MAIN RESULTS

Of a total of 216 citations identified by the systematic literature search, we included six randomised controlled trials (reported in nine publications), with a total of 576 participants. We identified a moderate heterogeneity of methodological quality and risk of bias of the included trials. None of the pooled results for our main outcomes of interest showed significant differences: delayed gastric emptying (OR 0.60; 95% CI 0.31 to 1.18; P = 0.14), mortality (RD -0.01; 95% CI -0.03 to 0.02; P = 0.72), postoperative pancreatic fistula (OR 0.98; 95% CI 0.65 to 1.47; P = 0.92), postoperative haemorrhage (OR 0.79; 95% CI 0.38 to 1.65; P = 0.53), intra-abdominal abscess (OR 0.93; 95% CI 0.52 to 1.67; P = 0.82), bile leakage (OR 0.89; 95% CI 0.36 to 2.15; P = 0.79), reoperation rate (OR 0.59; 95% CI 0.27 to 1.31; P = 0.20), and length of hospital stay (MD -0.67; 95%CI -2.85 to 1.51; P = 0.55). Furthermore, the perioperative outcomes duration of operation, intraoperative blood loss and time to NGT removal showed no relevant differences. Only one trial reported quality of life, on a subgroup of participants, also without a significant difference between the two groups at any time point. The overall quality of the evidence was only low to moderate, due to heterogeneity, some inconsistency and risk of bias in the included trials.

AUTHORS' CONCLUSIONS

There was low to moderate quality evidence suggesting no significant differences in morbidity, mortality, length of hospital stay, or quality of life between antecolic and retrocolic reconstruction routes for gastro- or duodenojejunostomy. Due to heterogeneity in definitions of the endpoints between trials, and differences in postoperative management, future research should be based on clearly defined endpoints and standardised perioperative management, to potentially elucidate differences between these two procedures. Novel strategies should be evaluated for prophylaxis and treatment of common complications, such as delayed gastric emptying.