Comparing a virtual reality head-mounted display to on-screen three-dimensional visualization and two-dimensional computed tomography data for training in decision making in hepatic surgery: a randomized controlled study

OBJECTIVE

Evaluation of the benefits of a virtual reality (VR) environment with a head-mounted display (HMD) for decision-making in liver surgery.

BACKGROUND

Training in liver surgery involves appraising radiologic images and considering the patient's clinical information. Accurate assessment of 2D-tomography images is complex and requires considerable experience, and often the images are divorced from the clinical information. We present a comprehensive and interactive tool for visualizing operation planning data in a VR environment using a head-mounted-display and compare it to 3D visualization and 2D-tomography.

METHODS

Ninety medical students were randomized into three groups (1:1:1 ratio). All participants analyzed three liver surgery patient cases with increasing difficulty. The cases were analyzed using 2D-tomography data (group "2D"), a 3D visualization on a 2D display (group "3D") or within a VR environment (group "VR"). The VR environment was displayed using the "Oculus Rift ™" HMD technology. Participants answered 11 questions on anatomy, tumor involvement and surgical decision-making and 18 evaluative questions (Likert scale).

RESULTS

Sum of correct answers were significantly higher in the 3D (7.1 ± 1.4, p < 0.001) and VR (7.1 ± 1.4, p < 0.001) groups than the 2D group (5.4 ± 1.4) while there was no difference between 3D and VR (p = 0.987). Times to answer in the 3D (6:44 ± 02:22 min, p < 0.001) and VR (6:24 ± 02:43 min, p < 0.001) groups were significantly faster than the 2D group (09:13 ± 03:10 min) while there was no difference between 3D and VR (p = 0.419). The VR environment was evaluated as most useful for identification of anatomic anomalies, risk and target structures and for the transfer of anatomical and pathological information to the intraoperative situation in the questionnaire.

CONCLUSIONS

A VR environment with 3D visualization using a HMD is useful as a surgical training tool to accurately and quickly determine liver anatomy and tumor involvement in surgery.

Clinical Research in Renal Transplantation: A Bibliometric Perspective on a Half-century of Innovation and Progress

BACKGROUND

Groundbreaking biomedical research has transformed renal transplantation (RT) into a widespread clinical procedure that represents the mainstay of treatment for end-stage kidney failure today. Here, we aimed to provide a comprehensive bibliometric perspective on the last half-century of innovation in clinical RT.

METHODS

The Web of Science Core Collection was used for a comprehensive screening yielding 123 303 research items during a 50-y period (January 1973-October 2022). The final data set of the 200 most-cited articles was selected on the basis of a citation-based strategy aiming to minimize bias.

RESULTS

Studies on clinical and immunological outcomes (n = 63 and 48), registry-based epi research (n = 38), and randomized controlled trials (n = 35) dominated the data set. Lead US authors have signed 110 of 200 articles. The overall level of evidence was high, with 84% of level1 and -2 reports. Highest numbers of these articles were published in New England Journal of Medicine , Transplantation , and American Journal of Transplantation. Increasing trend was observed in the number of female authors in the postmillennial era (26% versus 7%).

CONCLUSIONS

This study highlights important trends in RT research of the past half-century. This bibliometric perspective identifies the most intensively researched areas and shift of research interests over time; however, it also describes important imbalances in distribution of academic prolificacy based on topic, geographical aspects, and gender.

Evaluation of quality and quantity of randomized controlled trials in hepatobiliary surgery: A scoping/mapping review

AIM

To evaluate the quantity and quality of randomized controlled trials (RCTs) in hepatobiliary surgery and for identifying gaps in current evidences.

METHODS

A systematic search was conducted in MEDLINE (via PubMed), Web of Science, and Cochrane Controlled Register of Trials (CENTRAL) for RCTs of hepatobiliary surgery published from inception until the end of 2023. The quality of each study was assessed using the Cochrane risk-of-bias (RoB) tool. The associations between risk of bias and the region and publication date were also assessed. Evidence mapping was performed to identify research gaps in the field.

RESULTS

The study included 1187 records. The number and proportion of published randomized controlled trials (RCTs) in hepatobiliary surgery increased over time, from 13 RCTs (.0005% of publications) in 1970-1979 to 201 RCTs (.003% of publications) in 2020-2023. There was a significant increase in the number of studies with a low risk of bias in RoB domains (p < .01). The proportion of RCTs with low risk of bias improved significantly after the introduction of CONSORT guidelines (p < .001). The evidence mapping revealed a significant research focus on major and minor hepatectomy and cholecystectomy. However, gaps were identified in liver cyst surgery and hepatobiliary vascular surgery. Additionally, there are gaps in the field of perioperative management and nutrition intervention.

CONCLUSION

The quantity and quality of RCTs in hepatobiliary surgery have increased over time, but there is still room for improvement. We have identified gaps in current research that can be addressed in future studies.

Promising Results of Associating Liver Partition and Portal Vein Ligation for Staged Hepatectomy for Perihilar Cholangiocarcinoma in a Systematic Review and Single-Arm Meta-Analysis

BACKGROUND

ALPPS popularity is increasing among surgeons worldwide and its indications are expanding to cure patients with primarily unresectable liver tumors. Few reports recommended limitations or even contraindications of ALPPS in perihilar cholangiocarcinoma (phCC). Here, we discuss the results of ALPPS in patients with phCC in a systematic review as well as a pooled data analysis.

METHODS

MEDLINE and Web of Science databases were systematically searched for relevant literature up to December 2023. All studies reporting ALPPS in the management of phCC were included. A single-arm meta-analysis of proportions was carried out to estimate the overall rate of outcomes.

RESULTS

After obtaining 207 articles from the primary search, data of 18 studies containing 112 phCC patients were included in our systematic review. Rates of major morbidity and mortality were calculated to be 43% and 22%, respectively. The meta-analysis revealed a PHLF rate of 23%. One-year disease-free survival was 65% and one-year overall survival was 69%.

CONCLUSIONS

ALPPS provides a good chance of cure for patients with phCC in comparison to alternative treatment options, but at the expense of debatable morbidity and mortality. With refinement of the surgical technique and better perioperative patient management, the results of ALPPS in patients with phCC were improved.

Assessing textbook outcomes following major liver surgery in association with obesity at a referral academic center

INTRODUCTION

Outcomes of major surgeries in tertiary educational hospitals have been complicated by the referral of high-risk patients and the participation of trainees in surgical procedures. We analyzed outcomes of major hepatectomies in a tertiary academic setting emphasizing the role of training and obesity on textbook outcomes (TO).

MATERIALS AND METHODS

971 adult patients who underwent open major hepatectomy (Mesohepatectomy [n = 111], hemihepatectomy [n = 610], and extended hepatectomy [n = 250]) were evaluated. A TO was defined as: a negative resection margin, no grade B/C bile leak, no major complications, no in-hospital mortality, and no 30-day readmission. TOs were compared following operations performed by senior surgeons and those performed by junior surgeons under the supervision of senior surgeons and between patients with and without obesity.

RESULTS

TO was achieved in 70.1% of patients overall (78.4% in mesohepatectomy, 73.1% in hemihepatectomy, and 59.2% in extended hepatectomy). The rate of TO was similar following operations performed by and supervised by a senior surgeon (69.3% vs 71.0%, p = 0.570). The rate of TO was significantly lower in patients with obesity (41.5% vs 74.6%, p < 0.001). Factors including increased age (odds ratio [OR] for 10-year increase = 0.83, 95% confidence interval [CI]: 0.73-0.96, p = 0.009), obesity (OR = 0.25, 95%CI: 0.16-0.37, p < 0.001), biliodigestive anastomosis (OR = 0.27, 95%CI: 0.19-0.40, p < 0.001), and portal vein resection (OR = 0.49, 95%CI: 0.28-0.87, p = 0.014) lower the rate of TO.

CONCLUSION

Promising outcomes are possible after major hepatectomy in an academic setting. Obese patients and those undergoing more complex surgeries had a higher risk of poor postoperative outcomes.

Robot-assisted versus laparoscopic living donor nephrectomy: superior outcomes after completion of the learning curve

The use of robots in donor nephrectomy has increased in recent years. However, whether robot-assisted methods have better outcomes than traditional laparoscopic methods and how surgical experience influences these outcomes remains unclear. This meta-analysis compares the outcomes of robot-assisted donor nephrectomy (RADN) with those of laparoscopic donor nephrectomy (LDN) and to investigate the effects of surgical experience on these outcomes. A systematic literature search was conducted in Medline (through PubMed) and Web of Science databases. Perioperative data were extracted for meta-analysis. To assess the impact of the learning curve, a subgroup analysis was performed to compare outcomes between inexperienced and experienced surgeons. Seventeen studies with 6970 donors were included. Blood loss was lower (mean difference [MD] = - 13.28, p < 0.01) and the warm ischemia time was shorter (MD = - 0.13, p < 0.05) in the LDN group than the RADN group. There were no significant differences in terms of conversion to open surgery, operation time, surgical complications, hospital stay, costs, and delayed graft function between the groups. Subgroup analysis revealed that operation time (MD = - 1.09, p < 0.01) and length of hospital stay (MD = - 1.54, p < 0.05) were shorter and the rate of conversion to open surgery (odds ratios [OR] = 0.14, p < 0.0001) and overall surgical complications (OR = 0.23, p < 0.05) were lower in experienced RADN surgeons than in experienced LDN surgeons. Surgical experience enhances the perioperative outcomes following RADN more than it does following LDN. This suggests that RADN could be the method of choice for living donor nephrectomy as soon as surgeons gain sufficient experience in robotic surgery.

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.

Surgical management of primary liver cancers during the COVID-19 pandemic: overcoming the dilemma with standardization

BACKGROUND

The present study evaluates the impact of the pandemic on outcomes after surgical treatment for primary liver cancer in a high-volume hepatopancreatobiliary surgery center.

METHODS

Patients, who underwent liver resection for primary liver resection between January 2019 and February 2020, comprised pre-pandemic control group. The pandemic period was divided into two timeframes: early pandemic (March 2020-January 2021) and late pandemic (February 2021-December 2021). Liver resections during 2022 were considered as the post-pandemic period. Peri-, and postoperative patient data were gathered from a prospectively maintained database.

RESULTS

Two-hundred-eighty-one patients underwent liver resection for primary liver cancer. The number of procedures decreased by 37.1% during early phase of pandemic, but then increased by 66.7% during late phase, which was comparable to post-pandemic phase. Postoperative outcomes were similar between four phases. The duration of hospital stay was longer during the late phase, but not significantly different compared to other groups.

CONCLUSION

Despite an initial reduction in number of surgeries, COVID-19 pandemic had no negative effect on outcomes of surgical treatment for primary liver cancer. The structured standard operating protocol in a high-volume and highly specialized surgical center can withstand negative effects, a pandemic may have on treatment of patients.

Comparison of the modified piggyback with standard piggyback and conventional orthotopic liver transplantation techniques: a network meta-analysis

BACKGROUND

In conventional orthotopic liver transplantation (OLT), the recipient's retrohepatic inferior vena cava (IVC) is completely clamped and replaced with the donor IVC. The piggyback technique has been used to preserve venous return, either via an end-to-side or standard piggyback (SPB), or via a side-to-side or modified piggyback (MPB) anastomosis, using a venous cuff from the recipient hepatic veins with partially clamping and preserves the recipient's inferior vena cava. However, whether these piggyback techniques improve the efficacy of OLT is unclear. To address the low quality of the available evidence, we performed a meta-analysis to compare the efficacy of conventional, MPB, and SPB techniques.

METHODS

Literature was searched in Medline and Web of Science databases for relevant articles published until 2021 without any time restriction. A Bayesian network meta-analysis was performed to compare the intra- and postoperative outcomes of conventional OLT, MPB, and SPB techniques.

RESULTS

Forty studies were included, comprising 10,238 patients. MPB and SPB had significantly shorter operation times and fewer transfusions of red blood cell and fresh frozen plasma than conventional techniques. However, there were no differences between MPB and SPB in operation time and blood product transfusion. There were also no differences in primary non-function, retransplantation, portal vein thrombosis, acute kidney injury, renal dysfunction, venous outflow complications, length of hospital and intensive care unit stay, 90-day mortality rate, and graft survival between the three techniques.

CONCLUSION

MBP and SBP techniques reduce the operation time and need for blood transfusion compared with conventional OLT, but postoperative outcomes are similar. This indicates that all techniques can be implemented based on the experience and policy of the transplant center.

Declined Organs for Liver Transplantation: A Right Decision or a Missed Opportunity for Patients with Hepatocellular Carcinoma?

BACKGROUND

Liver transplantation is the only promising treatment for end-stage liver disease and patients with hepatocellular carcinoma. However, too many organs are rejected for transplantation.

METHODS

We analyzed the factors involved in organ allocation in our transplant center and reviewed all livers that were declined for transplantation. Reasons for declining organs for transplantation were categorized as major extended donor criteria (maEDC), size mismatch and vascular problems, medical reasons and risk of disease transmission, and other reasons. The fate of the declined organs was analyzed.

RESULTS

1086 declined organs were offered 1200 times. A total of 31% of the livers were declined because of maEDC, 35.5% because of size mismatch and vascular problems, 15.8% because of medical reasons and risk of disease transmission, and 20.7% because of other reasons. A total of 40% of the declined organs were allocated and transplanted. A total of 50% of the organs were completely discarded, and significantly more of these grafts had maEDC than grafts that were eventually allocated (37.5% vs. 17.7%, p < 0.001).

CONCLUSION

Most organs were declined because of poor organ quality. Donor-recipient matching at time of allocation and organ preservation must be improved by allocating maEDC grafts using individualized algorithms that avoid high-risk donor-recipient combinations and unnecessary organ declination.

Efficacy of Technical Modifications to the Associating Liver Partition and Portal Vein Ligation for Staged Hepatectomy (ALPPS) Procedure: A Systematic Review and Meta-Analysis

To compare the outcomes of modified-Associating Liver Partition and Portal vein Ligation for Staged hepatectomy (ALPPS) techniques with those of conventional-ALPPS.

Background

ALPPS is an established technique for treating advanced liver tumors.

Methods

PubMed, Web of Science, and Cochrane databases were searched. The outcomes were assessed by single-arm and 2-arm analyses.

Results

Seventeen studies containing 335 modified-ALPPS patients were included in single-arm meta-analysis. The estimated blood loss was 267 ± 29 mL (95% confidence interval [CI], 210-324 mL) during the first and 662 ± 51 mL (95% CI, 562-762 mL) during the second stage. The operation time was 166 ± 18 minutes (95% CI, 131-202 minutes) during the first and 225 ± 19 minutes (95% CI, 188-263 minutes) during the second stage. The major morbidity rate was 14% (95% CI, 9%-22%) after the first stage. The future liver remnant hypertrophy rate was 65.2% ± 5% (95% CI, 55%-75%) and the interstage interval was 16 ± 1 days (95% CI, 14-17 days). The dropout rate was 9% (95% CI, 5%-15%). The overall complication rate was 46% (95% CI, 37%-56%) and the major complication rate was 20% (95% CI, 14%-26%). The postoperative mortality rate was 7% (95% CI, 4%-11%). Seven studies containing 215 patients were included in comparative analysis. The hypertrophy rate was not different between 2 methods (mean difference [MD], -5.01; 95% CI, -19.16 to 9.14; P = 0.49). The interstage interval was shorter for partial-ALPPS (MD, 9.43; 95% CI, 3.29-15.58; P = 0.003). The overall complication rate (odds ratio [OR], 10.10; 95% CI, 2.11-48.35; P = 0.004) and mortality rate (OR, 3.74; 95% CI, 1.36-10.26; P = 0.01) were higher in the conventional-ALPPS.

Conclusions

The hypertrophy rate in partial-ALPPS was similar to conventional-ALPPS. This shows that minimizing the first stage of the operation does not affect hypertrophy. Moreover, the postoperative overall morbidity and mortality rates were lower following partial-ALPPS.

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.

Prognostic Value of Red Blood Cell Distribution Width (RDW) in the Recurrence of Hepatocellular Carcinoma Following Curative Resection

Purpose

Although surgery is associated with an acceptable cure rate, tumor recurrence is still a challenging issue in hepatocellular carcinoma (HCC) patients. Red blood cell distribution width (RDW) is considered an inflammatory marker for predicting overall mortality in a wide spectrum of malignancies. In the current study, the prognostic role of pre- and postoperative RDW in HCC recurrence after liver resection (LRx) is investigated.

Patients and Methods

In 395 patients, RDW levels were evaluated preoperatively as well as six and twelve months after curative LRx. The RDW cutoff values were determined using receiver operating characteristic curves (ROCs) according to the recurrence-free survival (RFS). Survival analyses were performed using the Kaplan-Meier, and differences were compared using the Log rank test.

Results

The RFS was significantly higher among patients with low RDW at the 6th month and 12th month, postoperatively (P < 0.001 and P = 0.028). RDW levels of higher than 16.15% at the 6th (HR: 2.047, P <0.001) and higher than 15.85% at 12th (HR: 3.105, P < 0.002) months after liver resection were independent predictors of RFS.

Conclusion

Postoperative RDW values seem to be predictive of tumor recurrence in HCC patients. RDW levels at the 6th and 12th months postoperatively were independent predictors of recurrence after LRx.

SmartPAN: in vitro and in vivo proof-of-safety assessments for an intra-operative predictive indicator of postoperative pancreatic fistula

Pancreatic surgery is complicated by untreated fluid leakage, but no tenable techniques exist to detect and close leakage sites during surgery. A novel hydrogel called SmartPAN has been developed to meet this need and is here assessed for safety before trials on human patients. Firstly, resazurin assays were used to test the cytotoxic effects of SmartPAN's active bromothymol blue (BTB) indicator and its solution of phosphate-buffered saline (PBS) on normal (HPDE: Human Pancreatic Duct Epithelial) or carcinomic (FAMPAC) human pancreatic cells. Cells incubated with BTB showed no significant reduction in cell viability below threshold safety levels. However, PBS had a mild cytotoxic effect on FAMPAC cells. Secondly, SmartPAN's pathological effects were evaluated in vivo by applying 4 mL SmartPAN to a porcine (Sus scrofa domesticus) model of pancreatic resection. There were no significant differences in macroscopic and microscopic pathologies between pigs treated with SmartPAN or saline. Thirdly, measurements using HPLC-MS/MS demonstrate that BTB does not cross into the bloodstream and was eliminated from the body within two days of surgery. Overall, SmartPAN appears safe in the short-term and ready for first-in-human trials because its components are either biocompatible or quickly neutralized by dilution and drainage.

pVHL-mediated SMAD3 degradation suppresses TGF-β signaling

Transforming growth factor β (TGF-β) signaling plays a fundamental role in metazoan development and tissue homeostasis. However, the molecular mechanisms concerning the ubiquitin-related dynamic regulation of TGF-β signaling are not thoroughly understood. Using a combination of proteomics and an siRNA screen, we identify pVHL as an E3 ligase for SMAD3 ubiquitination. We show that pVHL directly interacts with conserved lysine and proline residues in the MH2 domain of SMAD3, triggering degradation. As a result, the level of pVHL expression negatively correlates with the expression and activity of SMAD3 in cells, Drosophila wing, and patient tissues. In Drosophila, loss of pVHL leads to the up-regulation of TGF-β targets visible in a downward wing blade phenotype, which is rescued by inhibition of SMAD activity. Drosophila pVHL expression exhibited ectopic veinlets and reduced wing growth in a similar manner as upon loss of TGF-β/SMAD signaling. Thus, our study demonstrates a conserved role of pVHL in the regulation of TGF-β/SMAD3 signaling in human cells and Drosophila wing development.

A systematic review and meta-analysis of randomized controlled trials comparing laparoscopic and open liver resection

BACKGROUND/PURPOSE

The dissemination of laparoscopic liver resection (LLR) has been based on non-randomized studies and reviews of these. Aim of this study was to evaluate if the randomized evidence comparing LLR to open liver resection (OLR) supports these findings.

METHODS

A prospectively registered (reviewregistry866) systematic review and meta-analysis following Cochrane and PRISMA guidelines comparing LLR to OLR for benign and malignant diseases was performed via Medline, Web of Science, CENTRAL up to 31.12.2020. The main outcome was postoperative complications. Risk of bias was assessed with the Cochrane Risk of Bias tool 2.0, certainty of evidence was assessed using the GRADE approach.

RESULTS

The search yielded 2080 results. 13 RCTs assessing mostly minor liver resections with 1457 patients were included. There were reduced odds of experiencing any complication (Odds ratio (OR) [95% confidence interval (CI)]: 0·42 [0·30, 0·58]) and severe complications (OR[CI]: 0·51 [0·31, 0·84]) for patients undergoing LLR. LOS was shorter (Mean difference (MD) [CI]: -2·90 [-3·88, -1·92] days), blood loss was lower (MD: [CI]: -115·41 [-146·08, -84·75] ml), and functional recovery was better for LLR. All other outcomes showed no significant differences.

CONCLUSIONS

LLR shows significant postoperative benefits. RCTs assessing long-term outcomes and major resections are needed.

Applying an intraoperative predictive indicator for postoperative pancreatic fistula: randomized preclinical trial

Leaking pancreatic fluid can contribute to postoperative pancreatic fistula (POPF), which can complicate pancreatic surgery. Surgeons lack reliable tools to identify pancreatic leaks, so a novel hydrogel indicator called SmartPAN was developed for intraoperative application. In this preclinical efficacy assessment study, SmartPAN was capable of detecting sites associated with biochemical leak and POPF-related symptoms, thereby guiding effective closure. Thus, SmartPAN may help to reduce POPF development in upcoming clinical trials.

A fast and easy-to-learn technique for liver resection in a porcine model

Objective

Despite the recent advances in surgical techniques and perioperative care, liver resection (especially extended hepatectomy) is still a high-risk procedure with considerable morbidity and mortality. Experimental large animal models are the best option for studies in this regard. The present study was performed to present an easy-to-learn, fast, and multipurpose model of liver resection in a porcine model.

Method

Stepwise liver resections (resection of segments II/III, IVa/IVb, and VIII/IV) were performed in eight pigs with intraoperative monitoring of hemodynamic parameters. The technical aspects, tips, and tricks of this method are explained in detail.

Results

Based on the specific anatomical characteristics of the porcine liver, all resection types including segmental resection, hemihepatectomy, and extended hepatectomy could be performed in one animal in an easy-to-learn and fast technique. All animals were hemodynamically stable following stepwise liver resection.

Conclusion

Stepwise liver resection using stapler in a porcine model is a fast and easy-to-learn method with which junior staff and research fellows can perform liver resection up to extended hepatectomy under stable conditions.

Portal vein arterialization as a salvage procedure in hepatopancreatobiliary surgery: a systematic review

Background

Portal vein arterialization (PVA) is a possible option when hepatic artery reconstruction is impossible during liver resection. The aim of this study was to review the literature on the clinical application of PVA in hepatopancreatobiliary (HPB) surgery.

Methods

We performed a systematic review according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. We systematically searched the PubMed, Embase and Web of Science databases until December 2019. Experimental (animal) studies, review articles and letters were excluded.

Results

Twenty studies involving 57 patients were included. Cholangiocarcinoma was the most common indication for surgery (40 patients [74%]). An end-to-side anastomosis between a celiac trunk branch and the portal vein was the main PVA technique (35 patients [59%]). Portal hypertension was the most common long-term complication (12 patients [21%] after a mean of 4.1 mo). The median follow-up period was 12 (range 1–87) months. The 1-, 3- and 5-year survival rates were 64%, 27% and 20%, respectively.

Conclusion

Portal vein arterialization can be considered as a rescue option to improve the outcome in patients with acute liver de-arterialization when arterial reconstruction is not possible. To prevent portal hypertension and liver injuries due to thrombosis or overarterialization, vessel calibre adjustment and timely closure of the anastomosis should be considered. Further prospective experimental and clinical studies are needed to investigate the potential of this procedure in patients whose liver is suddenly de-arterialized during HPB procedures.

Case Report: Successful DaVinci-Assisted Major Liver Resection for Alveolar Echinococcosis

We report a case of successful robot-assisted major liver resection in a patient with liver alveolar echinococcosis (AE). A 62-year-old male patient was incidentally diagnosed with a large infiltrative lesion in the right liver lobe suspicious for AE. A radical surgical resection as a right-sided hemihepatectomy was indicated. The operation was carried out via a robotic-assisted procedure using the DaVinci Xi Surgical System. The tumor measured 12.4 × 8.8 cm and was successfully resected through a suprapubic incision of 13 cm. The patient was free of pain after the second post-operative day. A fluid collection near the resection plate was easily drained without bile leakage. The patient had no surgical complications. Radical resection is inevitable for adequate curative therapy of AE and provides clear margins. Robotic surgery is a relatively new and safe option for curative resection of AE lesions, with remarkable advantages for patients and surgeons.

HBV-infection rate and long-term outcome after liver-transplantation of anti-HBc-positive liver-grafts to HBV-naïve recipients: A retrospective study

BACKGROUND

Anti-HBc only positive liver grafts may be suitable for HBV-naive recipients insofar as an appropriate infection prophylaxis is performed. Therefore, we investigated the effect of prophylactic regimens on HBV infection prevention and long-term outcome of anti-HBc-positive graft recipients.

PATIENTS AND METHODS

This retrospective monocenter study consisted of a cohort of 1912 patients who underwent deceased donor liver transplantation at our transplant center between June 1987 and July 2019. 81 HBV-naïve patients after reception of an anti-HBc-positive liver-graft and consecutive HBV prophylaxis were selected for further examination. HBV infection rate and host- and graft-survival rates were compared to a matched control group consisting of 162 HBV-naïve patients after reception of anti-HBc-negative grafts. Pharmaceutical HBV prophylaxis included: only HBIG, only NUCs, or combined HBIG and NUCs.

RESULTS

Compared to control cases of HBV-naïve anti-HBc-negative graft recipients, no differences in host- and graft-survival rate were determined.13 of 81 anti-HBc-positive graft recipients (16%) developed HBV-infection after liver transplantation. No patient suffered from HBV infection after receiving modern NUCs. Survival analysis showed no statistical differences between patients with and without infection concerning host- and graft-survival.

CONCLUSION

Especially in times of organ shortage, anti-HBc-positive liver grafts may be useful for liver transplantation in HBV-naïve recipients. Efficient prophylactic regimens can prevent HBV-infection.

PREventive effect of FENestration with and without clipping on post-kidney transplantation lymphatic complications (PREFEN): study protocol for a randomised controlled trial

INTRODUCTION

Peritoneal fenestration is an effective preventive method for reducing the rate of lymphatic complications in kidney transplantation (KTx). The size of the fenestration plays an important role in its effectiveness. A large peritoneal window is no longer indicated, due to herniation and difficulties in performing biopsies. Small preventive fenestration is effective but will be closed too early. The aim of this study is to evaluate whether metal clips around the edges of a small fenestration result in optimal effects with minimum fenestration size.

METHODS AND ANALYSIS

This trial has been initiated in July 2019 and is expected to last for 2 and a half years. All patients older than 18 years, who receive kidneys from deceased donors, will be included. The kidney recipients will be randomly allocated to either a control arm (small fenestration alone) or an intervention arm (small fenestration with clipping). All fenestrations will be round, maximum 2 cm, and close to the kidney hilum. Clipping will be performed with eight metal clips around the peritoneal window (360°) in every 45° in an oblique position. The primary endpoint is the incidence of symptomatic post-KTx lymphatic complications, which require interventional treatment within 6 months after KTx. Secondary endpoints are intraoperative and postoperative outcomes, including blood loss, operation time, severity grade of lymphocele/lymphorrhea and relative symptoms.

ETHICS AND DISSEMINATION

This protocol study received approval from the Ethics Committee of the University of Heidelberg (Registration Number S-318/2017). A Standard Protocol Items: Recommendations for Interventional Trials checklist is available for this protocol. The results will be disseminated through peer-reviewed journals and conference presentations.

TRIAL REGISTRATION NUMBER

ClinicalTrials.gov Registry (NCT03682627).

Simulating Surgical Skills in Animals: Systematic Review, Costs & Acceptance Analyses

Background: Modern surgery demands high-quality and reproducibility. Due to new working directives, resident duty hours have been restricted and evidence exists that pure on-the-job training provides insufficient exposure. We hypothesize that supplemental simulations in animal models provide a realistic training to augment clinical experiences. This study reviews surgical training models, their costs and survey results illustrating academic acceptance.

Methods: Animal models were identified by literature research. Costs were analyzed from multiple German and Austrian training programs. A survey on their acceptance was conducted among faculty and medical students.

Results: 915 articles were analyzed, thereof 91 studies described in-vivo animal training models, predominantly for laparoscopy (30%) and microsurgery (24%). Cost-analysis revealed single-training costs between 307€ and 5,861€ depending on model and discipline. Survey results illustrated that 69% of the participants had no experience, but 66% would attend training under experienced supervision. Perceived public acceptance was rated intermediate by medical staff and students (4.26; 1–low, 10 high).

Conclusion: Training in animals is well-established and was rated worth attending in a majority of a representative cohort to acquire key surgical skills, in light of reduced clinical exposure. Animal models may therefore supplement the training of tomorrow's surgeons to overcome limited hands-on experience until virtual simulations can provide such educational tools.

Oral Preconditioning of Donors After Brain Death With Calcineurin Inhibitors vs. Inhibitors of Mammalian Target for Rapamycin in Pig Kidney Transplantation

Background: The systemic inflammatory cascade triggered in donors after brain death enhances the ischemia-reperfusion injury after organ transplantation. Intravenous steroids are routinely used in the intensive care units for the donor preconditioning. Immunosuppressive medications could be potentially used for this purpose as well. Data regarding donor preconditioning with calcineurin inhibitors or inhibitors of mammalian target for Rapamycin is limited. The aim of this project is to investigate the effects of (oral) donor preconditioning with a calcineurin inhibitor (Cyclosporine) vs. an inhibitor of mammalian target for Rapamycin (Everolimus) compared to the conventional administration of steroid in the setting of donation after brain death in porcine renal transplantation.

Methods: Six hours after the induction of brain death, German landrace donor pigs (33.2 ± 3.9 kg) were randomly preconditioned with either Cyclosporine (n = 9) or Everolimus (n = 9) administered via nasogastric tube with a repeated dose just before organ procurement. Control donors received intravenous Methylprednisolone (n = 8). Kidneys were procured, cold-stored in Histidine-Tryptophane-Ketoglutarate solution at 4°C and transplanted in nephrectomized recipients after a mean cold ischemia time of 18 h. No post-transplant immunosuppression was given to avoid confounding bias. Blood samples were obtained at 4 h post reperfusion and daily until postoperative day 5 for complete blood count, blood urea nitrogen, creatinine, and electrolytes. Graft protocol biopsies were performed 4 h after reperfusion to assess early histological and immunohistochemical changes.

Results: There was no difference in the hemodynamic parameters, hemoglobin/hematocrit and electrolytes between the groups. Serum blood urea nitrogen and creatinine peaked on postoperative day 1 in all groups and went back to the preoperative levels at the conclusion of the study on postoperative day 5. Histological assessment of the kidney grafts revealed no significant differences between the groups. TNF-α expression was significantly lower in the study groups compared with Methylprednisolone group (p = 0.01) Immunohistochemistry staining for cytochrome c showed no difference between the groups.

Conclusion: Oral preconditioning with Cyclosporine or Everolimus is feasible in donation after brain death pig kidney transplantation and reduces the expression of TNF-α. Future studies are needed to further delineate the role of oral donor preconditioning against ischemia-reperfusion injury.

Consensus on definition and severity grading of lymphatic complications after kidney transplantation

BACKGROUND

The incidence of lymphatic complications after kidney transplantation varies considerably in the literature. This is partly because a universally accepted definition has not been established. This study aimed to propose an acceptable definition and severity grading system for lymphatic complications based on their management strategy.

METHODS

Relevant literature published in MEDLINE and Web of Science was searched systematically. A consensus for definition and a severity grading was then sought between 20 high-volume transplant centres.

RESULTS

Lymphorrhoea/lymphocele was defined in 32 of 87 included studies. Sixty-three articles explained how lymphatic complications were managed, but none graded their severity. The proposed definition of lymphorrhoea was leakage of more than 50 ml fluid (not urine, blood or pus) per day from the drain, or the drain site after removal of the drain, for more than 1 week after kidney transplantation. The proposed definition of lymphocele was a fluid collection of any size near to the transplanted kidney, after urinoma, haematoma and abscess have been excluded. Grade A lymphatic complications have a minor and/or non-invasive impact on the clinical management of the patient; grade B complications require non-surgical intervention; and grade C complications require invasive surgical intervention.

CONCLUSION

A clear definition and severity grading for lymphatic complications after kidney transplantation was agreed. The proposed definitions should allow better comparisons between studies.

SmartPAN: A novel polysaccharide-microsphere-based surgical indicator of pancreatic leakage

Postoperative pancreatic fistula is a major surgical complication that can follow pancreatic resection. Postoperative pancreatic fistula can develop as a consequence of leaking pancreatic fluid, which calls for an intraoperative indicator of leakage. But suitable indicators of pancreatic leakage have yet to be found. This study details the evidence-based development and early efficacy assessments of a novel pancreatic leakage indicator (SmartPAN), following the IDEAL framework of product development. We developed 41 SmartPAN prototypes by combining indicators of pancreatic fluid with a polysaccharide-microsphere matrix. The prototypes were assessed in vitro using porcine ( Sus scrofa domesticus) pancreatic tissue and ex vivo with human pancreatic fluid. From these initial tests, we chose a hydrogel-based compound that uses the pH indicator bromothymol blue to detect alkali pancreatic fluid. This prototype was then assessed in vivo for usability, effectiveness and reliability using a porcine model. Treatment groups were defined by SmartPAN-reaction at initial pancreatic resection: indicator-positive or negative. Indicator-positive individuals randomly received either targeted closure of leakage sites or no further closure. We assessed SmartPAN’s reliability and effectiveness by monitoring abdominal drainage for amylase and with relaparotomy after 48 h. SmartPAN responses were consistent between both surgical procedures and conformed to amylase measurements. In conclusion, we have developed the first surgery-ready indicator for predicting the occurrence of pancreatic leakage during pancreatic resection. SmartPAN can enable targeted prophylactic closure in a simple and reliable way, and thus may reduce the impact of postoperative pancreatic fistula by guiding peri- and post-operative management.

Evaluation of the role of transhepatic flow in postoperative outcomes following major hepatectomy (THEFLOW): study protocol for a single-centre, non-interventional cohort study

INTRODUCTION

Liver resection is the only curative treatment for primary and secondary hepatic tumours. Improvements in perioperative preparation of patients and new surgical developments have made complex liver resections possible. However, small for size and flow syndrome (SFSF) is still a challenging issue, rendering patients inoperable and causing postoperative morbidity and mortality. Although the role of transhepatic flow in the postoperative outcome has been shown in small partial liver transplantation and experimental studies of SFSF, this has never been studied in the clinical setting following liver resection. The aim of this study is to systematically evaluate transhepatic flow changes following major liver resection and its correlation with postoperative outcomes.

METHODS AND ANALYSIS

The TransHEpatic FLOW (THEFLOW) study is a single-centre, non-interventional cohort study, and aims to enrol 50 patients undergoing major hepatectomy (defined as hemihepatectomy or extended hepatectomy based on the Brisbane classification) with or without prior chemotherapy. The portal venous flow, hepatic artery flow and portal venous pressure are measured before and after each resection. All patients are followed-up for 3 months after the operation. During each evaluation, standard clinical data, posthepatectomy liver failure and overall morbidity and mortality will be recorded. THEFLOW study was initiated on 25 March 2018 and is expected to progress for 2 years.

ETHICS AND DISSEMINATION

This protocol study received approval from the Ethics Committee of the University of Heidelberg (registration number: S576/2017). The results of this study will be published in a peer-reviewed journal, and will also be presented at medical meetings.

TRIAL REGISTRATION NUMBER

NCT03762876.

Pre-transplant CD200 and CD200R1 concentrations are associated with post-transplant events in kidney transplant recipients

CD200 is an immunoglobulin superfamily membrane protein that binds to a myeloid cell-specific receptor and induces inhibitory signaling. The aim of this study was to investigate the role of CD200 and its receptor (CD200R1) on kidney transplant (KTx) outcome. In a collective of 125 kidney recipients (University hospital, Heidelberg, Germany), CD200 and CD200R1 concentrations were evaluated immediately before transplantation. Recipient baseline and clinical characteristics and KTx outcome, including acute rejection (AR), acute tubular necrosis, delayed graft function, cytomegalovirus (CMV) and human polyomaviridae (BK) virus infections, and graft loss were evaluated during the first post-transplant year. The association of CD200 and CD200R1 concentrations and CD200R1/CD200 ratios with the outcome of KTx was investigated for the first time in a clinical setting in a prospective cohort. There was a positive association between pre-transplant CD200R1 concentrations and CMV (re)activation (P = .041). Also, increased CD200R1 concentration was associated with a longer duration of CMV infection (P = .049). Both the frequency of AR and levels of creatinine (3 and 6 months after KTx) were significantly higher in patients with an increased CD200R1/CD200 ratio (median: 126 vs 78, P = .008). Increased pre-transplant CD200R1/CD200 ratios predict immunocompetence and risk of AR, whereas high CD200R1 concentrations predict immunosuppression and high risk of severe CMV (re)activation after KTx.

Standardized endocystectomy technique for surgical treatment of uncomplicated hepatic cystic echinococcosis

BACKGROUND

Two surgical options are available for cystic echinococcosis (CE). The two principal approaches are radical (resection of the cyst) and conservative (evacuation of the cyst content and partial removal of the cyst capsule). Here, we describe a standardized endocystectomy technique for hepatic echinococcosis.

SUBJECTS AND METHODS

Twenty-one patients (male/female: 4/3; median age: 28 years) with uncomplicated, isolated hepatic CE (cyst stages WHO CE1, 2, 3a, and 3b) that were treated with the standardized endocystectomy described in this paper. Before the operation and during the follow-up period (mean: 33.8 months, median: 24 months), patients underwent clinical and sonographical and/or magnetic resonance imaging assessment during regular visits managed by an interdisciplinary team.

RESULTS

Forty-seven cysts were treated with the standardized endocystectomy technique. The median number of cysts per patient was two (range: 1-8). Nine patients (43%) had a single cystic lesion. The median operation time was 165 minutes and the median intraoperative bleeding volume was 200 mL. The median hospital stay was nine days (range: 6-28 days). Morbidity (Clavien-Dindo III) occurred in four patients (19%). No mortality and no recurrence were found during the median follow-up time of 24 months.

CONCLUSIONS

The standardized endocystectomy technique presented is a safe procedure with acceptable morbidity, no mortality, and without recurrences in our patient series. Important components of our CE management are interdisciplinary patient care, adequate diagnostic work-ups, and regular pre- and postoperative visits, including long-term follow-up for early and reliable capture of recurrences.

Technical Aspects of Stapled Hepatectomy in Liver Surgery: How We Do It

There are diverse approaches to parenchymal transection and the preferred approach remains controversial among liver surgeons. Stapling devices, which were initially established for vascular control, have been the standard parenchymal transection technique in many departments for more than 15 years. This article describes the technical aspects, tips, and tricks of stapled hepatectomy using right hemihepatectomy as an example. The existing literature on this topic is also reviewed.

Surgical outcomes after pediatric kidney transplantation at the University of Heidelberg

BACKGROUND

Kidney transplantation (KTx) is the treatment of choice for children with end-stage renal disease (ESRD).

OBJECTIVE

An update of 48 years of surgical experience with pediatric KTx (PKTx) is presented, and the results between recipients of organs from deceased donors (DDs) and living donors (LDs) are compared.

STUDY DESIGN

All patients younger than 18 years who underwent KTx between 1967 and 2015 were evaluated. Data from 540 PKTx operations (409 DD and 131 LD) were obtained from the transplant center database. Peri-operative data and graft and patient survival were analyzed in the DD and LD groups.

RESULTS

Fewer recipients in the LD group underwent dialysis before PKTx than those in the DD group (50.8% in LD vs. 94.9% in DD, P < 0.001). The mean duration of dialysis (DD: 798 ± 525 days vs. LD: 625 ± 650 days, P = 0.03), time on the waiting list (DD: 472 ± 435 days vs. LD: 120 ± 243 days, P < 0.001), cold ischemia time (CIT) (DD: 1206 ± 368 min vs. LD: 140 ± 63 min, P < 0.001), operation time, and hospital stay were lower in the LD group. Except for arterial stenosis, the rates of postoperative vascular and urological complications were not different between the two groups. The cumulative 25-year graft and patient survival rates were 46.4% and 84.1% in the DD group and 76.5% and 96.1% in the LD group, respectively.

DISCUSSION

PKTx is the treatment of choice for children with ESRD. Graft quality has a direct impact on KTx outcome and rate of graft failure. Better HLA compatibility and shorter CIT reduce the impairment of graft function after LD PKTx. In addition, Establishment of an interdisciplinary approach using an individualized risk assessment and prevention model can improve PKTx outcomes.

CONCLUSION

Compared with DD PKTx, LD PKTx has better graft survival associated with a shorter duration of preceding dialysis, waiting time, and CIT and seems to be more beneficial for children.

Prophylactic onlay reinforcement with absorbable mesh (polyglactin) is associated with less early wound complications after kidney transplantation: A preliminary study

Incidence of wound complications after kidney transplantation (KTx) is still considerable. Here, we report the impact of prophylactic absorbable polyglactin (Vicryl®) mesh reinforcement on the incidence of short-term post-KTx wound complications. Sixty-nine patients were analyzed; 23 with and 46 without preventive onlay mesh reinforcement. Surgical site infections (SSI) were seen in six (26%) patients in the mesh group and in 17 (37%) patients in no-mesh group. A lower, but not statistically significant, rate of early postoperative wound complications occurred in the mesh group. Wound complications were observed in seven (30%) patients in the mesh group and in 23 (50%) patients in the no-mesh group. There was no association between mesh placement and SSI incidence (odds ratios [OR] 0.60, 95% confidence interval [CI] 0.20-1.82, p = 0.369) and wound complications (OR 0.44, 95% CI 0.15-1.26, p = 0.126). Therefore, we conclude that mesh reinforcement does not increase the risk of SSI and overall wound complications. Long-term outcomes have to be evaluated in a randomized trial setting. © 2019 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater 108B:67-72, 2020.

Preoperative Thrombocytopenia May Predict Poor Surgical Outcome after Extended Hepatectomy

Background

It is a novel idea that platelet counts may be associated with postoperative outcome following liver surgery. This may help in planning an extended hepatectomy (EH), which is a surgical procedure with high morbidity and mortality.

Aim

The aim of this study was to evaluate the predictive potential of platelet counts on the outcome of EH in patients without portal hypertension, splenomegaly, or cirrhosis.

Methods

A series of 213 consecutive patients underwent EH (resection of ≥ five liver segments) between 2001 and 2016. The association of preoperative platelet counts with posthepatectomy liver failure (PHLF), morbidity (based on Clavien-Dindo classification), and 30-day mortality was evaluated using multivariate analysis.

Results

PHLF was detected in 26.3% of patients, major complications in 26.8%, and 30-day mortality in 11.3% of patients. Multivariate analysis revealed that the preoperative platelet count is an independent predictor of PHLF (odds ratio [OR] 4.4, 95% confidence interval [CI] 1.3-15.0, p=0.020) and 30-day mortality (OR 4.4, 95% CI 1.1-18.8, p=0.043).

Conclusions

Preoperative platelet count is associated with PHLF and mortality following extended liver resection. This association was independent of other related parameters. Prospective studies are needed to evaluate the predictive role and to determine the impact of preoperative correction of platelet count on postoperative outcomes after EH.

Hand-Assisted laparoscopic donor nephrectomy PERiumbilical versus Pfannenstiel incision and return to normal physical ACTivity (HAPERPACT): study protocol for a randomized controlled trial

Background

Hand-assisted laparoscopic living donor nephrectomy (HALDN) using a periumbilical or Pfannenstiel incision was developed to improve donor outcome after a kidney transplant. The aim of this study was to investigate two methods of hand assistance and kidney removal during HALDN and their effect on the time it takes for the donor to return to normal physical activity.

Methods/design

This study was initiated in November 2017 and is expected to last for 2 years. To be eligible for the study, donors must be more than 20 years of age and must not be receiving permanent pain therapy. Only donors with a single artery and vein in the graft are being enrolled in this trial. Donors with infections or scars in the periumbilical or hypogastric area, bleeding disorders, chronic use of immunosuppressive agents, or active infection will be excluded. Donors will be randomly allocated to either a control arm (periumbilical incision) or an intervention arm (Pfannenstiel incision). The sample size was calculated as 26 organ donors in each group. The primary endpoint is the number of days it takes the donor to return to normal physical activity (up to 4 weeks after the operation). Secondary endpoints are intraoperative outcomes, including estimated blood loss, warm ischemia time, and duration of the operation. Postoperative pain will be assessed using the visual analog scale, rescue analgesic use, and peak expiratory flow rate. Length of hospital stay, physical activity score, time to return to work, donor satisfaction, cosmetic score, postoperative complications, and all-cause mortality in living donors will also be reported. Delayed graft function, primary non-function, serum creatinine levels, and glomerular filtration rate will also be assessed in the recipients after transplantation.

Discussion

This is the first randomized controlled trial to compare the time it takes the living donor to return to normal physical activity after HALDN using two different types of incision. The comprehensive findings of this study will help decide which nephrectomy procedure is best for living donors with regard to patient comfort and satisfaction as well as graft function in the recipient after transplantation.

Trial registration

ClinicalTrials.gov, NCT03317184. Registered on 23 October 2017.

Electronic supplementary material

The online version of this article (10.1186/s13063-018-2775-4) contains supplementary material, which is available to authorized users.

Meta-analysis of the prognostic role of perioperative platelet count in posthepatectomy liver failure and mortality

BACKGROUND

Emerging evidence suggests that the perioperative platelet count (PLT) can predict posthepatectomy liver failure (PHLF). In this systematic review and meta-analysis, the impact of perioperative PLT on PHLF and mortality was evaluated.

METHODS

MEDLINE and Web of Science databases were searched systematically for relevant literature up to January 2018. All studies comparing PHLF or mortality in patients with a low versus high perioperative PLT were included. Study quality was assessed using methodological index for non-randomized studies (MINORS) criteria. Meta-analyses were performed using Mantel-Haenszel tests with a random-effects model, and presented as odds ratios (ORs) with 95 per cent confidence intervals.

RESULTS

Thirteen studies containing 5260 patients were included in the meta-analysis. Two different cut-off values for PLT were used: 150 and 100/nl. Patients with a perioperative PLT below 150/nl had higher PHLF (4 studies, 817 patients; OR 4·79, 95 per cent c.i. 2·89 to 7·94) and mortality (4 studies, 3307 patients; OR 3·78, 1·48 to 9·62) rates than patients with a perioperative PLT of 150/nl or more. Similarly, patients with a PLT below 100/nl had a significantly higher risk of PHLF (4 studies, 949 patients; OR 4·65, 2·60 to 8·31) and higher mortality rates (7 studies, 3487 patients; OR 6·35, 2·99 to 13·47) than patients with a PLT of 100/nl or greater.

CONCLUSION

A low perioperative PLT correlates with higher PHLF and mortality rates after hepatectomy.

The optimal intestinal segment length for experimental size-mismatched intestinal transplantation: Defining the maximum length with the lowest blood flow needs in a porcine model

Transplanted Intestinal Segments (IS) must match the perfusion capacities of the recipient. This can be challenging during a size-mismatched SBTX. In this study, we defined the maximum IS length with lowest blood flow needs in a porcine model by evaluating the physiological perfusion rates of different IS lengths. Blood flow in the SMA, aorta segment four, and general circulatory parameters were monitored before and after sequential intestinal resection. IS lengths of 30 cm, 60 cm, 120 cm, and 300 cm (n = 8 each) were compared. The IS blood flow requirements increased with IS length (30 cm: 19.5 ± 3.4 mL/min; 60 cm: 16.9 ± 6.7 mL/min; 120 cm: 34.9 ± 8.5 mL/min; 300 cm: 62.9 ± 11.6 mL/min). Absolute IS blood flow (P = .004), percentage IS blood flow uptake from the SMA (P = .001), and percentage IS blood flow uptake from the aorta (P = .005) increased significantly between 60 cm and 120 cm. We concluded that 60 cm was the maximum IS length before blood flow demands significantly increased in a porcine model.

Does acid-base equilibrium correlate with remnant liver volume during stepwise liver resection?

Small for size and flow syndrome (SFSF) is one of the most challenging complications following extended hepatectomy (EH). After EH, hepatic artery flow decreases and portal vein flow increases per 100 g of remnant liver volume (RLV). This causes hypoxia followed by metabolic acidosis. A correlation between acidosis and posthepatectomy liver failure has been postulated but not studied systematically in a large animal model or clinical setting. In our study, we performed stepwise liver resections on nine pigs to defined SFSF limits as follows: step 1: segment II/III resection, step 2: segment IV resection, step 3: segment V/VIII resection (RLV: 75, 50, and 25%, respectively). Blood gas values were measured before and after each step using four catheters inserted into the carotid artery, internal jugular vein, hepatic artery, and portal vein. The pH, [Formula: see text], and base excess (BE) decreased, but [Formula: see text] values increased after 75% resection in the portal and jugular veins. EH correlated with reduced BE in the hepatic artery. Pco₂ values increased after 75% resection in the jugular vein. In contrast, arterial Po₂ increased after every resection, whereas the venous Po₂ decreased slightly. There were differences in venous [Formula: see text], BE in the hepatic artery, and Pco₂ in the jugular vein after 75% liver resection. Because 75% resection is the limit for SFSF, these noninvasive blood evaluations may be used to predict SFSF. Further studies with long-term follow-up are required to validate this correlation.NEW & NOTEWORTHY This is the first study to evaluate acid-base parameters in major central and hepatic vessels during stepwise liver resection. The pH, [Formula: see text], and base excess (BE) decreased, but [Formula: see text] values increased after 75% resection in the portal and jugular veins. Extended hepatectomy correlated with reduced BE in the hepatic artery. Because 75% resection is the limit for small for size and flow syndrome (SFSF), postresection blood gas evaluations may be used to predict SFSF.

Indocyanine green fluorescence imaging in hepatobiliary surgery

Indocyanine green (ICG) is a fluorescent dye that has been widely used for fluorescence imaging during hepatobiliary surgery. ICG is injected intravenously, selectively taken up by the liver, and then secreted into the bile. The catabolism and fluorescence properties of ICG permit a wide range of visualization methods in hepatobiliary surgery. We have characterized the applications of ICG during hepatobiliary surgery into: 1) liver mapping, 2) cholangiography, 3) tumor visualization, and 4) partial liver graft evaluation. In this literature review, we summarize the current understanding of ICG use during hepatobiliary surgery. Intra-operative ICG fluorescence imaging is a safe, simple, and feasible method that improves the visualization of hepatobiliary anatomy and liver tumors. Intravenous administration of ICG is not toxic and avoids the drawbacks of conventional imaging. In addition, it reduces post-operative complications without any known side effects. ICG fluorescence imaging provides a safe and reliable contrast for extra-hepatic cholangiography when detecting intra-hepatic bile leakage following liver resection. In addition, liver tumors can be visualized and well-differentiated hepatocellular carcinoma tumors can be accurately identified. Moreover, vascular reconstruction and outflow can be evaluated following partial liver transplantation. However, since tissue penetration is limited to 5-10mm, deeper tissue cannot be visualized using this method. Many instances of false positive or negative results have been reported, therefore further characterization is required.

YouTube as a Potential Training Resource for Laparoscopic Fundoplication

OBJECTIVE

To analyze the surgical proficiency and educational quality of YouTube videos demonstrating laparoscopic fundoplication (LF).

DESIGN

In this cross-sectional study, a search was performed on YouTube for videos demonstrating the LF procedure. The surgical and educational proficiency was evaluated using the objective component rating scale, the educational quality rating score, and total video quality score. Statistical significance was determined by analysis of variance, receiver operating characteristic curve, and odds ratio analysis.

RESULTS

A total of 71 videos were included in the study; 28 (39.4%) videos were evaluated as good, 23 (32.4%) were moderate, and 20 (28.2%) were poor. Good-rated videos were significantly longer (good, 22.0 ± 5.2min; moderate, 7.8 ± 0.9min; poor, 8.5 ± 1.0min; p = 0.007) and video duration was predictive of good quality (AUC, 0.672 ± 0.067; 95% CI: 0.541-0.802; p = 0.015). For good quality, the cut-off video duration was 7:42 minute. This cut-off value had a sensitivity of 67.9%, a specificity of 60.5%, and an odds ratio of 3.23 (95% CI: 1.19-8.79; p = 0.022) in predicting good quality. Videos uploaded from industrial sources and with a higher views/days online ratio had a higher objective component rating scale and total video quality score. In contrast, the likes/dislikes ratio was not predictive of video quality.

CONCLUSIONS

Many videos showing the LF procedure have been uploaded to YouTube with varying degrees of quality. A process for filtering LF videos with high surgical and educational quality is feasible by evaluating the video duration, uploading source, and the views/days online ratio. However, alternative videos platforms aimed at professionals should also be considered for educational purposes.

Small for Size and Flow (SFSF) syndrome: An alternative description for posthepatectomy liver failure

Small for Size Syndrome (SFSS) syndrome is a recognizable clinical syndrome occurring in the presence of a reduced mass of liver, which is insufficient to maintain normal liver function. A definition has yet to be fully clarified, but it is a common clinical syndrome following partial liver transplantation and extended hepatectomy, which is characterized by postoperative liver dysfunction with prolonged cholestasis and coagulopathy, portal hypertension, and ascites. So far, this syndrome has been discussed with focus on the remnant size of the liver after partial liver transplantation or extended hepatectomy. However, the current viewpoints believe that the excessive flow of portal vein for the volume of the liver parenchyma leads to over-pressure, sinusoidal endothelial damages and haemorrhage. The new hypothesis declares that in both extended hepatectomy and partial liver transplantation, progression of Small for Size Syndrome is not determined only by the "size" of the liver graft or remnant, but by the hemodynamic parameters of the hepatic circulation, especially portal vein flow. Therefore, we suggest the term "Small for Size and Flow (SFSF)" for this syndrome. We believe that it is important for liver surgeons to know the pathogenesis and manifestation of this syndrome to react early enough preventing non-reversible tissue damages.

Hepatic Hemodynamic Changes Following Stepwise Liver Resection

AIM

Extended liver resection has increased during the last decades. However, hepatic hemodynamic changes after resection and the consequent complications like post hepatectomy liver failure are still a challenging issue. The aim of this study was to systematically evaluate the role of stepwise liver resection on hepatic hemodynamic changes.

METHODS

To evaluate this effect we performed 25, 50, and 75 % sequential liver resections in 10 pigs. Before and after each resection, the hepatic artery flow and portal vein flow in relation to the remnant liver volume (RLV) as well as hepatic vascular pressures were measured and compared between the groups.

RESULTS

Following sequential liver resection, the hepatic artery flow /100 g decreases and the portal vein flow increases up to 17 and 167 % following extended liver resection (75 %), respectively. Also, during stepwise liver resection, the portal vein pressure increases gradually up to 33 % following extended hepatectomy (75 %).

CONCLUSION

Sequential decrease in the RLV decreases the hepatic artery flow /100 g and increases the portal vein flow /100 g and portal vein pressure. As the consequence, the liver goes under more poor-oxygenated blood supply and higher pressure. This may be one of the most important mechanisms of the post hepatectomy liver failure in case of extended liver resection.

Long-Term Follow-Up of Kidney Transplant Recipients With Polycystic Kidney Disease

OBJECTIVES

Patients with polycystic kidney disease are candidates for kidney transplant. We report the results of our single center study of 250 first transplant recipients with polycystic kidney disease (autosomal dominant [64%], medullary cystic [16%], autosomal recessive [6%], and nonspecified [14%]).

MATERIALS AND METHODS

Patient groups were divided and analyzed according to the origin of the graft (deceased donor or living donor). We also analyzed demographic data of donors and recipients, waiting time, duration of dialysis, transfusion, nephrectomy, hospitalization, morbidities, and graft and patient survival. The study was approved by the Ethical Review Committee of the Institute. All of the protocols conformed to the ethical guidelines of the 1975 Helsinki Declaration.

RESULTS

The deceased-donor group comprised 79% and the living-donor group comprised 21% of the cases. Nephrectomy was performed on 21% of the recipients. The deceased-donor group showed significantly higher values than the living-donor group regarding rate of hemodialysis (82% vs 68%), duration of dialysis (1571 vs 1002 days), waiting time (1129 vs 33 days), and blood transfusions (45% vs 27%). In deceased-donor versus living-donor transplant recipients, surgical complications included arterial stenosis (1% vs 0%), venous thrombosis (1% vs 0%), urine leakage (0.5% vs 1.9%), ureteral stenosis (0.5% vs 0%), reflux (0% vs 1.9%), lymphocele (11.7% vs 8.1%), and hernia (5.2% vs 8.1%), with no statistically significant differences shown between the groups. The living-donor group had graft and patient survival rates as high as the deceased-donor group.

CONCLUSIONS

The low rate of morbidity and excellent survival rates make kidney transplant an excellent option for patients with polycystic kidney disease. Although fear of future appearance of polycystic kidney disease may reduce the rate of related living donors, our study showed that graft and patient survival rates in the living-donor group were as high as in the deceased-donor group.