Incisional hernia repair following pancreatic surgery-open vs laparoscopic approach

INTRODUCTION

For pancreatic procedures, transverse and midline or combined approaches are used. Having an increased morbidity after pancreatic surgery, these patients have an increased risk of developing an incisional hernia. In the following, we will analyze how the results of incisional hernia surgery after pancreatic surgery are presented in the Herniamed Registry.

METHODS

Hospitals and surgeons from Germany, Austria and Switzerland can voluntarily enter all routinely performed hernia operations prospectively into the Herniamed Registry. All patients sign a special informed consent declaration that they agree to the documentation of their treatment in the Herniamed Registry. Perioperative complications (intraoperative complications, postoperative complications, complication-related reoperations and general complications) are recorded up to 30 days after surgery. After 1, 5, and 10 years, patients and primary care physicians are contacted and asked about any pain at rest, pain on exertion, chronic pain requiring treatment or recurrence. This retrospective analysis of prospectively collected data compares the outcomes of minimally invasive vs open techniques in incisional hernia repair after pancreatic surgery.

RESULTS

Relative to the total number of all incisional hernia patients in the Herniamed Registry, the proportion after pancreatic surgery with 1-year follow-up was 0.64% (n = 461) patients. 95% of previous pancreatic surgeries were open. Minimally invasive incisional hernia repair was performed in 17.1% and open repair in 82.9% of cases. 23.2% of the defects were larger than 10 cm and 32.8% were located laterally or were a combination of lateral and medial defects. Among the few differences between the collectives, a significantly higher rate of defect closure (58.1% vs 25.3%; p < 0.001) and drainage (72.8% vs 13.9%; p < 0.001) was found in the open repairs, and larger meshes were seen in the minimally invasive procedures (340.6 cm2 vs 259.6 cm2; p < 0.001). No difference deemed a risk factor for chronic postoperative pain was seen in the rate of preoperative pain between the open and minimally invasive procedures (Appendix Table 4) No significant differences were found in either the perioperative complications or at 1-year follow-up.

CONCLUSIONS

Incisional hernias after complex pancreatic surgery can be repaired safely and with a low recurrence rate in both open and minimally invasive techniques.

Surgical complications requiring late surgical revisions after pancreatoduodenectomy increase postoperative morbidity and mortality

BACKGROUND

Pancreatoduodenectomies are complex surgical procedures with considerable postoperative morbidity and mortality. Here, we describe complications and outcomes in patients requiring surgical revisions following pancreatoduodenectomy.

METHODS

A total of 1048 patients undergoing a pancreatoduodenectomy at our institution between 2002 and 2019 were analyzed retrospectively. All patients with surgical revisions were included. Revisions were divided into early and late using a cut-off of 5 days after the first surgery. Statistical significance was examined by using chi-square tests and Fisher's exact tests. Survival analysis was performed using Kaplan-Meier curves and log-rank tests.

RESULTS

A total of 150 patients with at least 1 surgical revision after pancreatoduodenectomy were included. Notably, 64 patients had a revision during the first 5 days and were classified as early revision. Compared with the 86 patients with late revisions, we found no differences concerning wound infections, delayed gastric emptying, or acute kidney failure. After late revisions, we found significantly more cases of sepsis (31.4% late versus 15.6% early, p = 0.020) and reintubation due to respiratory failure (33.7% versus 18.8%, p = 0.031). Postoperative mortality was significantly higher within the late revision group (23.2% versus 9.4%, p = 0.030).

CONCLUSION

Arising complications after pancreatoduodenectomy should be addressed as early as possible as patients requiring late surgical revisions frequently developed septic complications and multiorgan failure.

Oncological recurrence following pathological complete response after neoadjuvant treatment in patients with esophageal cancer - a retrospective cohort study

BACKGROUND

To evaluate recurrence in patients with post-neoadjuvant pathological complete response (pCR) and in patients with complete response of primary tumor but persisting lymphatic spread of disease (non-pCR, ypT0ypN +) of esophageal cancer.

METHODS

Seventy-five patients (63 pCR, 12 non-pCR) were analyzed retrospectively. Pattern and incidence of local and distant recurrence as well as the impact on overall (OS) and disease-free survival (DFS) were evaluated. The efficacy of neoadjuvant chemotherapy according to FLOT protocol was compared to neoadjuvant chemoradiation according to CROSS protocol.

RESULTS

In the pCR group, isolated local recurrence was diagnosed in 3%, while no isolated local recurrence was observed in the non-pCR group due to the high incidence of distant recurrence. Distant recurrence was most common in both cohorts (isolated distant recurrence: pCR group 10% to non-pCR group 55%; simultaneous distant and local recurrence: pCR group 3% to non-pCR group 18%). Median time to distant recurrence was 5.5 months, and median time to local recurrence was 8.0 months. Cumulative incidence of distant recurrence (with and without simultaneous local recurrence) was 16% (± 6%) in pCR patients and 79% (± 13%) in non-pCR patients (hazard ratio (HR) 0.123) estimated by Kaplan-Meier method. OS (HR 0.231) and DFS (HR 0.226) were significantly improved in patients with pCR compared to patients with non-pCR. Advantages for FLOT protocol compared to CROSS protocol, especially with regard to distant control of disease (HR 0.278), were observed (OS (HR 0.361), DFS (HR 0.226)).

CONCLUSION

Distant recurrence is the predominant site of treatment failure in patients with pCR and non-pCR grade 1a regression, whereby recurrence rates are much higher in patients with non-pCR.

Postoperative Hiatal Hernia after Ivor Lewis Esophagectomy-A Growing Problem in the Age of Minimally Invasive Surgery

BACKGROUND

Even though minimally invasive esophagectomy is a safe and oncologically effective procedure, several authors have reported an increased risk of postoperative hiatal hernia (PHH). This study evaluates the incidence and risk factors of PHH after hybrid minimally invasive (HMIE) versus open esophagectomy (OE).

METHODS

A retrospective single-center analysis was performed on patients who underwent Ivor Lewis esophagectomy between January 2009 and April 2018. Computed tomography scans and patient files were reviewed to identify the PHH.

RESULTS

306 patients were included (152 HMIE; 154 OE). Of these, 23 patients (8%) developed PHH. Most patients (13/23, 57%) were asymptomatic at the time of diagnosis and only 4 patients (17%) presented in an emergency setting with incarceration. The rate of PHH was significantly higher after HMIE compared to OE (13.8% vs. 1.3%, p < 0.001). No other risk factors for the development of PHH were identified in uni- or multi-variate analysis. Surgical repair of PHH was performed in 19/23 patients (83%). The recurrence rate of PHH after surgical repair was 32% (6/19 patients).

CONCLUSIONS

The development of PHH is a relevant complication after hybrid minimally invasive esophagectomy. Although most patients are asymptomatic, surgical repair is recommended to avoid incarceration with potentially fatal outcomes. Innovative techniques for the prevention and repair of PHH are urgently needed.

Proximal gastrectomy and double-tract reconstruction vs total gastrectomy in gastric and gastro-esophageal junction cancer patients - a systematic review and meta-analysis protocol (PROSPERO registration number: CRD42021291500)

BACKGROUND

In Germany and Western Europe, gastroesophageal junction cancer (AEG) and proximal gastric cancer are currently treated with (transhiatal-extended) total gastrectomy (TG) according to the latest treatment guidelines. TG leads to a severe and long-lasting impairment of postoperative health-related quality of life (HRQoL) of the treated patients. Recent studies have suggested that HRQoL of these patients could be improved by proximal gastrectomy with double-tract reconstruction (PG-DTR) without compromising oncologic safety. Our aim is therefore to conduct a randomized controlled non-inferiority trial comparing PG-DTR with TG in AEG II/III and gastric cancer patients with overall survival as primary endpoint and HRQoL as key secondary endpoint.

METHODS

This protocol is written with reference to the Preferred Reporting Items for Systematic Review and Meta-Analysis Protocols (PRISMA-P 2015) statement. We will conduct searches in the electronic databases MEDLINE, Web of Science Core Collection, ScienceDirect, and Cochrane Library. We will also check references of relevant studies and perform a cited reference research. Titles and abstracts of the records identified by the searches will be screened, and full texts of all potentially relevant articles will be obtained. We will consider randomized trials and non-randomized studies. The selection of studies, data extraction, and assessment of risk of bias of the included studies will be conducted independently by two reviewers. Meta-analysis will be performed using RevMan 5.4 (Review Manager (RevMan) Version 5.4, The Cochrane Collaboration).

DISCUSSION

This systematic review will identify the current study pool concerning the comparison of TG and PG-DTR and help to finally refine the research questions and to allow an evidence-based trial design of the planned multicenter randomized-controlled trial.

ETHICS AND DISSEMINATION

Ethical approval is not required for this systematic review. Study findings will be shared by publication in a peer-reviewed journal.

SYSTEMATIC REVIEW REGISTRATION

PROSPERO CRD42021291500.

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.

Pathological complete response in multimodal treatment of esophageal cancer: a retrospective cohort study

To evaluate pathological complete response (pCR, ypT0ypN0) after neoadjuvant treatment compared with non-complete response (non-CR) in patients with esophageal cancer (EC), and 393 patients were retrospectively analyzed. Survival probability was analyzed in patients with: (i) pCR vs non-CR; (ii) complete response of the primary tumor but persisting lymphatic metastases (non-CR-T0N+) and (iii) pCR and tumor-free lymphnodes exhibiting signs of postneoadjuvant regression vs. no signs of regression. (i) Median overall survival (mOS) was favorable in patients with pCR (pCR: mOS not reached vs. non-CR: 41 months, P < 0.001). Multivariate analysis revealed that grade of regression was not an independent predictor for prolonged survival. Instead, the achieved postneoadjuvant TNM-stage (T-stage: Hazard ratio [HR] ypT3-T4 vs. ypT0-T2: 1.837; N-stage: HR ypN1-N3 vs. ypN0: 2.046; Postneoadjuvant M-stage: HR ypM1 vs. ycM0: 2.709), the residual tumor (R)-classification (HR R1 vs. R0: 4.195) and the histologic subtype of EC (HR ESCC vs. EAC: 1.688) were prognostic factors. Patients with non-CR-T0N+ have a devastating prognosis, similar to those with local non-CR and lymphatic metastases (non-CR-T + N+) (non-CR-T0N+: 22.0 months, non-CR-T + N-: mOS not reached, non-CR-T + N+: 23.0 months; P-values: non-CR-T0N+ vs. non-CR-T + N-: 0.016; non-CR-T0N+ vs. non-CR-T + N+: 0.956; non-CR-T + N- vs. non-CR-T + N+: <0.001). Regressive changes in lymphnodes after neoadjuvant treatment did not influence survival-probability in patients with pCR (mOS not reached in each group; EAC-patients: P = 0.0919; ESCC-patients: P = 0.828). Particularly, the achieved postneoadjuvant ypTNM-stage influences the survival probability of patients with EC. Patients with non-CR-T0N+ have a dismal prognosis, and only true pathological complete response with ypT0ypN0 offers superior survival probabilities.

Study Protocol of a Prospective Multicenter Study on Patient Participation for the Clinical Trial: Surgery as Needed Versus Surgery on Principle in Post-Neoadjuvant Complete Tumor Response of Esophageal Cancer (ESORES)

Ideally, patient-centered trial information material encourages the discussion with the treating physician, and helps patients making trade-offs regarding treatment decisions In a situation of possible equivalent treatment options in terms of overall survival (OS), it can make it easier to weigh up advantages and disadvantages. Preferences for choice of treatment in esophageal cancer (EC) are complex, and no standardized assessment tools are available. We will explore patient’s factors for treatment choice and develop a comprehensive patient information leaflet for the inclusion into randomized controlled trials (RCT) on EC. We conduct a cross-sectional, observational study based on a mixed-methods design with patients suffering from non-metastatic EC with post-neoadjuvant complete response after neoadjuvant chemotherapy (nCT) or neoadjuvant chemoradiation (nCRT), to develop patient-centered trial information material. This pilot study is performed in a concept development phase and a subsequent pilot phase. We start with patient interviews (n = 10–15) in the concept development phase to evaluate patients’ needs, and develop a Preference and Decision Aid Questionnaire (PDAQ). We pre-test the PDAQ with another n = 10 patients with EC after nCT or nCRT, former patients from a self-help organization, and n = 10 medical experts for their comments on the questionnaire. In the pilot phase, a multicenter trial using the PDAQ and additional measures is carried out (n = 120). Based on evidence of a possible equivalence in terms of OS of the treatment options “surgery as needed” and “surgery on principle” in patients with post-neoadjuvant complete response of EC, this pilot study on patient participation is conducted to assess patient’s needs and preferences, and optimize patients’ inclusion in a planned RCT. The aim is to develop patient-centered trial information material for the RCT to increase patients’ consent and compliance with the randomized treatment. The trial is registered at the German Clinical Trials Register (DRKS00022050, October 15, 2020).

[Complete response after neoadjuvant therapy for esophageal cancer : Implications for surgery]

A relevant number of patients with locally advanced esophageal squamous cell carcinoma and adenocarcinoma show a locoregional complete response of the tumor in the resected material after neoadjuvant therapy with modern chemotherapy and chemoradiation protocols. Due to a high rate of perioperative morbidity and decreased long-term quality of life following esophagectomy, the current treatment algorithm with neoadjuvant therapy and post-neoadjuvant esophagectomy on principle is critically questioned. An individualized treatment algorithm with extended clinical evaluation of post-neoadjuvant remission status and esophagectomy as needed is discussed. Patients with complete remission after neoadjuvant therapy are identified in an extended restaging protocol. Cases of clinical complete remission are treated with an active surveillance concept with esophagectomy as needed, i.e. surgery only when a local tumor recurrence is detected. Retrospective cohort studies have suggested that the active surveillance concept with esophagectomy as needed does not lead to a deterioration of overall survival rates in the patient collective. European prospective randomized, controlled, noninferiority studies with an oncological endpoint are currently evaluating the possibilities of organ-preserving concepts for clinical complete remission of esophageal cancer.

Perioperative cell-free mutant KRAS dynamics in patients with pancreatic cancer

This prospective observational biomarker trial evaluated the diagnostic and prognostic value of circulating KRAS mutations (cmKRAS) and their perioperative dynamics in patients with resectable pancreatic ductal adenocarcinoma (PDAC). Plasma cmKRAS samples (G12D, G12V, G12R, and G12C) were analysed by droplet digital PCR in 51 patients with resectable PDAC, 20 with advanced PDAC, and 34 with non-malignant pancreatic pathology. Preoperative detection of cmKRAS alone did not correlate with poorer overall and disease-free survival in this patient cohort. However, a perioperative change in cmKRAS, particularly accurate when an intraoperative sample was included, was identified as a new and useful marker for prediction of prolonged survival.

Promising biomarker

Postneoadjuvant surveillance and surgery as needed compared with postneoadjuvant surgery on principle in multimodal treatment for oesophageal cancer: a scoping review protocol

INTRODUCTION

In current medical practice of curative treatment for non-metastatic oesophageal cancer, surgery on principle is carried out by oesophagectomy after neoadjuvant treatment. However, oesophagectomy is often associated with postoperative morbidity and mortality. Taking into account that modern neoadjuvant therapy is effective and many of patients show no vital tumour cells in the operative specimens, we aim to perform a scoping review as part of the development phase for a prospectively planned multicentre randomised controlled trial investigating 'surgery as needed vs surgery on principle in patients with postneoadjuvant complete response of oesophageal cancer' (Prospective trial registration number DRKS00022801). This scoping approach will allow us to finally define and/or adapt the research question including the design and methodology of the randomised controlled trial taking into account the findings for example, research gaps and/or pitfalls in the currently available study pool addressing this or very similar questions.

METHODS AND ANALYSIS

To identify relevant research, we will conduct searches in the electronic databases Medline, Web of Science Core Collection, Cochrane Library and Science Direct. We will also check references of relevant studies and perform a cited reference research (forward citation tracking). Titles and abstracts of the records identified by the searches will be screened and full texts of all potentially relevant articles will be obtained. We will consider randomised trials and non-randomised controlled studies. Data extraction tables will be set up, including study and patients' characteristics, aim of study and reported outcomes. We will summarise the data using tables and figures (eg, bubble plots) to present the research landscape and to describe potential clusters and/or gaps to support the planning of a randomised trial in this patient population.

ETHICS AND DISSEMINATION

Ethical approval is not required for this scoping review. Study findings will be shared by publication in a peer-reviewed journal and by presentation to key stakeholders on scientific meetings.

Post-Neoadjuvant Surveillance and Surgery as Needed Compared with Post-Neoadjuvant Surgery on Principle in Multimodal Treatment for Esophageal Cancer: A Scoping Review

Simple Summary

A substantial fraction of patients with esophageal cancer show post-neoadjuvant pathological complete response (pCR). Principal esophagectomy after neoadjuvant treatment is the standard of care for all patients, including those with pCR. Surveillance and surgery as needed may be a treatment alternative for these patients. We performed a scoping review and described all relevant clinical studies addressing these two treatment approaches. We identified three completed randomized controlled trials (RCTs) including 468 participants, three planned/ongoing RCTs with a planned sample size of 752 participants, one non-randomized controlled study with 53 participants, ten retrospective cohort studies (2228 participants) and one survey on patients’ preferences (100 participants). The current scoping review reveals that although surveillance and surgery as needed has been investigated within different study designs, the available study pool show methodological limitations and clinical results are heterogeneous. A thoroughly planned RCT considering these limitations will be of great importance to provide these patients with the best treatment.

Abstract

Background: A substantial fraction of patients with esophageal cancer show post-neoadjuvant pathological complete response (pCR). Principal esophagectomy after neoadjuvant treatment is the standard of care for all patients, although surveillance and surgery as needed in case of local recurrence may be a treatment alternative for patients with complete response (CR). Methods: We performed a scoping review to describe key characteristics of relevant clinical studies including adults with non-metastatic esophageal cancer receiving multimodal treatment. Until September 2020, relevant studies were identified through systematic searches in the bibliographic databases Medline, Web of Science, Cochrane Library, Science Direct, ClinicalTrials, the German study register, and the WHO registry platform. Results: In total, three completed randomized controlled trials (RCTs, with 468 participants), three planned/ongoing RCTs (with a planned sample size of 752 participants), one non-randomized controlled study (NRS, with 53 participants), ten retrospective cohort studies (with 2228 participants), and one survey on patients’ preferences (with 100 participants) were identified. All studies applied neoadjuvant chemoradiation protocols. None of the studies examined neoadjuvant chemotherapeutic protocols. Studies investigated patient populations with esophageal squamous cell carcinoma, adenocarcinoma, and mixed cohorts. Important outcomes reported were overall, disease-free and local recurrence-free survival. Limitations of the currently available study pool include heterogeneous chemoradiation protocols, a lack of modern neoadjuvant treatment protocols in RCTs, short follow-up times, the use of heterogeneous diagnostic methods, and different definitions of clinical CR. Conclusion: Although post-neoadjuvant surveillance and surgery as needed compared with post-neoadjuvant surgery on principle has been investigated within different study designs, the currently available results are based on a wide variation of diagnostic tools to identify patients with pCR, short follow-up times, small sample sizes, and variations in therapeutic procedures. A thoroughly planned RCT considering the limitations in the currently available literature will be of great importance to provide patients with CR with the best and less harmful treatment.

Longitudinal analysis of cell-free mutated KRAS and CA 19-9 predicts survival following curative resection of pancreatic cancer

Background

Novel biomarkers and molecular monitoring tools hold potential to improve outcome for patients following resection of pancreatic ductal adenocarcinoma (PDAC). We hypothesized that the combined longitudinal analysis of mutated cell-free plasma KRAS (cfKRAS^mut) and CA 19–9 during adjuvant treatment and follow-up might more accurately predict disease course than hitherto available parameters.

Methods

Between 07/2015 and 10/2018, we collected 134 plasma samples from 25 patients after R0/R1-resection of PDAC during adjuvant chemotherapy and post-treatment surveillance at our institution. Highly sensitive discriminatory multi-target ddPCR assays were employed to screen plasma samples for cfKRAS^mut. cfKRAS^mut and CA 19–9 dynamics were correlated with recurrence-free survival (RFS) and overall survival (OS). Patients were followed-up until 01/2020.

Results

Out of 25 enrolled patients, 76% had undergone R0 resection and 48% of resected PDACs were pN0. 17/25 (68%) of patients underwent adjuvant chemotherapy. Median follow-up was 22.0 months, with 19 out of 25 (76%) patients relapsing during study period. Median RFS was 10.0 months, median OS was 22.0 months. Out of clinicopathologic variables, only postoperative CA 19–9 levels and administration of adjuvant chemotherapy correlated with survival endpoints. cfKRAS^mut. was detected in 12/25 (48%) of patients, and detection of high levels inversely correlated with survival endpoint. Integration of cfKRAS^mut and CA 19–9 levels outperformed either individual marker. cfKRAS^mut outperformed CA 19–9 as dynamic marker since increase during adjuvant chemotherapy and follow-up was highly predictive of early relapse and poor OS.

Conclusions

Integrated analysis of cfKRAS^mut and CA 19–9 levels is a promising approach for molecular monitoring of patients following resection of PDAC. Larger prospective studies are needed to further develop this approach and dissect each marker’s specific potential.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12885-020-07736-x.

Curative-intent pancreas resection for pancreatic metastases: surgical and oncological results

Background

Pancreatic metastasis is a rare cause for pancreas surgery and often a sign of advanced disease no chance of curative-intent treatment. However, surgery for metastasis might be a promising approach to improve patients’ survival. The aim of this study was to analyze the surgical and oncological outcome after pancreatic resection of pancreatic metastasis.

Methods

This is a retrospective cohort analysis of a prospectively-managed database of patients undergoing pancreatic resection at the University of Freiburg Pancreatic Center from 2005 to 2017.

Results

In total, 29 of 1297 (2%) patients underwent pancreatic resection due to pancreatic metastasis. 20 (69%) patients showed metastasis of renal cell carcinoma (mRCC), followed by metastasis of melanoma (n = 5, 17%), colon cancer (n = 2, 7%), ovarian cancer (n = 1, 3%) and neuroendocrine tumor of small intestine (n = 1, 3%). Two (7%) patients died perioperatively. Median follow-up was 76.4 (range 21–132) months. 5-year and overall survival rates were 82% (mRCC 89% vs. non-mRCC 67%) and 70% (mRCC 78% vs. non-mRCC 57%), respectively. Patients with mRCC had shorter disease-free survival (14 vs. 22 months) than patients with other primary tumor entities.

Conclusion

Despite malignant disease, overall survival of patients after metastasectomy for pancreatic metastasis is acceptable. Better survival appears to be associated with the primary tumor entity. Further research should focus on molecular markers to elucidate the mechanisms of pancreatic metastasis to choose the suitable therapeutic approach for the individual patient.

Management and outcomes of intraductal papillary mucinous neoplasms

Background

This study evaluated the outcome and survival of patients with radiologically suspected intraductal papillary mucinous neoplasms (IPMNs).

Methods

IPMN management was reviewed according to Fukuoka risk factors and IPMN localization, differentiating main‐duct (MD), mixed‐type (MT) and branch‐duct (BD) IPMNs. Perioperative results were compared with those of patients undergoing resection of pancreatic ductal adenocarcinoma (PDAC) over the same interval (2010–2014). Overall (OS) and disease‐specific (DSS) survival rates were calculated and subgroups compared.

Results

Of 142 patients with IPMNs, 26 had MD‐IPMN, eight had MT‐IPMN and 108 had BD‐IPMN. Some 74 per cent of patients with MD‐ and MT‐IPMN were managed by primary resection, whereas this was used in only 27·8 per cent of those with BD‐IPMN. The risk of secondary resection and malignant transformation for BD‐IPMNs smaller than 20 mm was 8 and 2 per cent respectively during follow‐up. Pancreatic head resection of IPMNs was associated with an increased risk of postoperative pancreatic fistula grade B/C compared with resection of PDAC (12 of 33 (36 per cent) versus 41 of 221 (18·6 per cent) respectively; P = 0·010), and greater morbidity and mortality (Clavien–Dindo grade III: 15 of 33 (45 per cent) versus 56 of 221 (25·3 per cent) respectively; grade IV: 1 (3 per cent) versus 7 (3·2 per cent); grade V: 2 (6 per cent) versus 2 (0·9 per cent); P = 0·008). Five‐year OS and DSS rates in patients with MD‐IPMN were worse than those for MT‐ and BD‐IPMN (OS: 44, 86 and 97·4 per cent respectively, P < 0·001; DSS: 60, 100 and 98·6 per cent; P < 0·001). Patients with invasive IPMN had worse OS and DSS rates than those with non‐invasive dysplasia (OS: IPMN‐carcinoma (10 patients) 33 per cent, high‐grade dysplasia 100 per cent, intermediate‐grade dysplasia 63 per cent, low grade‐dysplasia 100 per cent, P < 0·001; DSS: IPMN‐carcinoma 43 per cent, all grades of dysplasia 100 per cent, P < 0·001). Patients with high‐risk stigmata had poorer survival than those without risk factors (OS: high‐risk stigmata (35 patients) 55 per cent, worrisome features (31) 95 per cent, no risk factors (76) 100 per cent, P < 0·001; DSS: 71, 100 and 100 per cent respectively, P < 0·001).

Conclusion

The risk of malignant transformation was very low for BD‐IPMNs, but the development of high‐risk stigmata was associated with disease‐specific mortality. Patients with IPMN had greater morbidity after resection than those having resection of PDAC.

Management and outcome of esophageal stenting for spontaneous esophageal perforations

Treatment of spontaneous esophageal perforation (SEP) consists of different conservative, surgical and endoscopic treatment modalities. In this study, we evaluated the clinical efficacy and the outcome of covered self-expanding stent (CSES) treatment of SEP. All patients with SEP treated by CSES at our institution between 2005 and 2014 were included in this prospective single-center study. The data were collected from a prospective database based on clinical, endoscopic and operative reports. Follow-up data were procured by contacting the patients or their family doctors. The patient data were analyzed concerning course of treatment, leakage sealing rate, complications, and mortality. Patients with iatrogenic or malignant perforations were excluded. In total, 16 patients underwent endoscopic CSES placement for SEP between 2005 and 2014. Sealing of the leakage was immediately successful in 50% (8 patients). A second stent was placed in 5 patients, but did not achieve sealing of the perforation in any case, requiring a switch in treatment to a surgical procedure (n=4) or drainage of the persisting leakage (n=4). In-hospital mortality was 13%. Only delayed treatment was identified as a risk factor for inferior outcome. Patients with successful CSES treatment had a shorter ICU- and hospital stay and had a reduced risk of developing esophageal stenosis (RR: 0.4) or persisting dysphagia despite treatment (RR: 0.33). Endoscopic treatment of SEP is beneficial to the patient if immediately successful, but in our experience, failure rates are higher than described in the literature. Secondary placement of CSES was not successful when initial stent treatment failed, while both surgical intervention and drainage of the perforation showed good results in sealing the leakage.

Prediction of successful discectomy using MRI quantitation of dural sac and herniated disc dimensions

OBJECTIVE

To evaluate the ability of magnetic resonance imaging (MRI) quantitation of disc prolapse and dural sac to identify those who would benefit from discectomy.

METHODS

Thirty consecutive patients with disc herniation and leg pain who had MRI of lumbar spine and subsequently underwent discectomy were prospectively enrolled and compared with 30 controls. The anteroposterior (AP) diameter and the cross-sectional area of disc prolapse and of dural sac were measured. The ratios of AP diameters and cross-sectional areas were calculated. The measurements were correlated with the relief of symptoms based on a visual analogue scale assessment preoperatively and 1 week postoperatively.

RESULTS

All patients preoperatively had a pain score of seven or higher (mean +/- SD = 7.9 +/- 0.3) and postoperatively a score of < or = 2(mean +/- SD = 1.1 +/- 0.2). The AP diameter of disc prolapse and the ratio of AP diameters demonstrated the highest sensitivity and specificity: an AP diameter of 3.3 mm was 99% sensitive and specific and a ratio of the AP diameters of 0.37 was 100% sensitive and 99% specific.

CONCLUSION

Quantitative measurements of MRI can improve significantly the ability to identify the patients who would benefit from discectomy.

Wall shear stress in intracranial self-expanding stents studied using ultra-high-resolution 3D reconstructions

BACKGROUND AND PURPOSE

Imaging of intracranial stents is constrained by resolution limits of current clinical imaging techniques providing insufficient visualization of deployment details and impeding its use for computational hemodynamic (CHD) simulations. The purpose of our study was to evaluate whether ultra-high-resolution MicroCT scans can illuminate detailed aspects of realistic in vitro stent deployment and serve as a reliable basis for CHD simulations of blood flow through self-expanding intracranial stents.

MATERIALS AND METHODS

A Neuroform Treo (NF) stent and an Enterprise (ENT) stent were deployed in identical straight polytetrafluoroethylene tubes filled with contrast agent. MicroCT scans were obtained at a spatial resolution of 14 mum and used for ultra-high-resolution 3D reconstructions. CHD simulations were performed, with particular emphasis on local flow behavior near the wall and struts. Flow differences between the geometrically different stents were studied.

RESULTS

MicroCT data revealed strut prolapse near the markers for the closed-cell design (ENT) stent and at some of the unconnected vertices of the open-cell design (NF) stent, which also showed some misalignments. CHD simulations showed that reverse wall shear stress occurred near some of the strut vertices and markers for the NF but only near the markers for the ENT.

CONCLUSIONS

This work demonstrates the feasibility of ultra-high-resolution MicroCT imaging in elucidating important details of intracranial stent deployment as a basis for accurate CHD simulations and in enabling a structural and hemodynamic study of realistically deployed stents with different geometry and design.

Cytotoxic T cell immunity against telomerase reverse transcriptase in humans

Telomerase is a ribonucleoprotein enzyme which has been linked to malignant transformation in human cells. Telomerase activity is increased in the vast majority of human tumors, making its gene product the first molecule common to all human tumors. The generation of endogenously processed telomerase peptides bound to Class I MHC molecules could therefore target cytotoxic T lymphocytes (CTL) to tumors of different origins. This could advance vaccine therapy against cancer provided that precursor CTL recognizing telomerase peptides in normal adults and cancer patients can be expanded through immunization. We demonstrate here that the majority of normal individuals and patients with prostate cancer immunized in vitro against two HLA-A2.1 restricted peptides from telomerase reverse transcriptase (hTRT) develop hTRT-specific CTL. This suggests the existence of precursor CTL for hTRT in the repertoire of normal individuals and in cancer patients. Most importantly, the CTL of cancer patients specifically lysed a variety of HLA-A2(+) cancer cell lines, demonstrating immunological recognition of endogenously processed hTRT peptides. Moreover, in vivo immunization of HLA-A2.1 transgenic mice generated a specific CTL response against both hTRT peptides. Based on the induction of CTL responses in vitro and in vivo, and the susceptibility to lysis of tumor cells of various origins by hTRT CTL, we suggest that hTRT could serve as a universal cancer vaccine for humans.

Synthesis and structure-activity relationships of 3,7-dimethyl-1-propargylxanthine derivatives, A2A-selective adenosine receptor antagonists

A series of 8-substituted derivatives of 3,7-dimethyl-1-propargylxanthine (DMPX) was synthesized and investigated as A2A adenosine receptor antagonists. Different synthetic strategies for the preparation of DMPX derivatives and analogues were explored. A recently developed synthetic procedure starting from 3-propargyl-5,6-diaminouracil proved to be the method of choice for the preparation of this type of xanthine derivatives. The novel compounds were investigated in radioligand binding studies at the high-affinity adenosine receptor subtypes A1 and A2A and compared with standard A2A adenosine receptor antagonists. Structure-activity relationships were analyzed in detail. 8-Styryl-substituted DMPX derivatives were identified that exhibit high affinity and selectivity for A2A adenosine receptors, including 8-(m-chlorostyryl)-DMPX (CS-DMPX, Ki A2A = 13 nM, 100-fold selective), 8-(m-bromostyryl)-DMPX (BS-DMPX, Ki A2A = 8 nM, 146-fold selective), and 8-(3,4-dimethoxystyryl)-DMPX (Ki A2A = 15 nM, 167-fold selective). These and other novel compounds are superior to the standard A2A adenosine receptor antagonists KF17837 (4) and CSC (5) with respect to A2A affinity and/or selectivity.

Reinterpretation of endothelial cell gaps induced by vasoactive mediators in guinea-pig, mouse and rat: many are transcellular pores

1. In response to vascular permeabilizing agents, particulates circulating in the blood extravasate from venules through endothelial cell openings. These openings have been thought to be intercellular gaps though recently this view has been challenged. 2. To define the precise location of endothelial cell gaps, serial section electron microscopy and three-dimensional reconstructions were performed in skin and cremaster muscle of guinea-pigs, mice and rats injected locally with agents that enhance microvascular permeability: vascular permeability factor, histamine or serotonin. Ferritin and colloidal carbon were injected intravenously as soluble and particulate macromolecular tracers, respectively. 3. Both tracers extravasated from venules in response to all three permeability enhancing agents. The soluble plasma protein ferritin extravasated primarily by way of vesiculo-vacuolar organelles (VVOs), interconnected clusters of vesicles and vacuoles that traverse venular endothelium. In contrast, exogenous particulates (colloidal carbon) and endogenous particulates (erythrocytes, platelets) extravasated from plasma through transendothelial openings. 4. Serial electron microscopic sections and three-dimensional reconstructions demonstrated that eighty-nine of ninety-two openings were transendothelial pores, not intercellular gaps. Pore frequency increased 3- to 33-fold when carbon was used as tracer. 5. The results demonstrate that soluble and particulate tracers extravasate from venules by apparently different transcellular pathways in response to vasoactive mediators. However, some pores may derive from rearrangements of VVOs.

Vesiculo-vacuolar organelles and the regulation of venule permeability to macromolecules by vascular permeability factor, histamine, and serotonin

In contrast to normal microvessels, those that supply tumors are strikingly hyperpermeable to circulating macromolecules such as plasma proteins. This leakiness is largely attributable to a tumor-secreted cytokine, vascular permeability factor (VPF). Tracer studies have shown that macromolecules cross tumor vascular endothelium by way of a recently described cytoplasmic organelle, the vesiculo-vacuolar organelle or VVO (VVOs are grapelike clusters of interconnected, uncoated vesicles and vacuoles). However, equivalent VVOs are also present in the cytoplasm of normal venules that do not leak substantial amounts of plasma protein. To explain these findings, we hypothesized that VPF increased the permeability of tumor blood vessels by increasing VVO function and that the VVOs of normal venules were relatively impermeable in the absence of VPF stimulation. To test this hypothesis, VPF was injected intradermally in normal animals after intravenous injection of a soluble macromolecular tracer, ferritin, whose extravasation could be followed by electron microscopy. VPF caused normal venules to leak ferritin, and, as predicted by our hypothesis, ferritin extravasated by way of VVOs, just as in hyperpermeable tumor microvessels. Ultrathin (14-nm) serial electron microscopic sections and computer-aided three-dimensional reconstructions better defined VVO structure. VVOs occupied 16-18% of endothelial cytoplasm in normal venules. Individual VVOs were clusters of numerous (median, 124) interconnected vesicles and vacuoles that formed complex pathways across venular endothelium with multiple openings to both luminal and abluminal surfaces. Like VPF, histamine and serotonin also stimulated ferritin extravasation across venules by way of VVOs. Together, these data establish VVOs as the major pathway by which soluble plasma proteins exit venules in response to several mediators that increase venular hyperpermeability. These same mediators also increased the extravasation of colloidal carbon, but this large particulate nonphysiological tracer exited venules primarily through endothelial gaps.

Healing segmental femoral defects in sheep using recombinant human bone morphogenetic protein

A middiaphyseal, 2.5-cm osteoperiosteal segmental defect stabilized by plate fixation was created in the right femur of 17 sheep. Four treatment groups were included: Group I, no implant; Group II, inactive bone matrix; Group III, recombinant human bone morphogenetic protein (rhBMP-2) mixed with inactive bone matrix; and Group IV, autogeneic bone graft. Three animals had early failure of fixation, and the remaining 14 were evaluated at three months after implantation. Radiographs showed bony union of all defects treated with rhBMP-2 (six) and a lack of bony union in the negative-control groups treated with no implant (three) and inactive bone matrix without BMP (three). Both defects treated with autograft healed. New bone formation in the defect sites treated with rhBMP-2 first appeared one month after implantation and had a mean bending strength (expressed as a percentage of the contralateral femur) of 91% +/- 59% (mean +/- standard deviation) for defects treated with BMP-2, 77% +/- 34% for autograft, 9% +/- 8% for no implant, and 11% +/- 7% for inactive matrix without BMP. Three sheep treated with rhBMP-2 had their fixation plates removed at four months and were followed for one year. Their bone defect sites remained solidly healed one year after the initial operation.