Learning curves in robot-assisted minimally invasive liver surgery at a high-volume center in Denmark: Report of the first 100 patients and review of literature

BACKGROUND AND OBJECTIVE

Minimally invasive liver surgery is evolving worldwide, and robot-assisted liver surgery (RLS) can deliver obvious benefits for patients. However, so far no large case series have documented the learning curve for RLS.

METHODS

We conducted a retrospective study for robotic liver surgery (RLS) from June 2019 to June 2022 where 100 patients underwent RLS by the same surgical team. Patients' variables, short-term follow-up, and the learning curve were analyzed. A review of the literature describing the learning curve in RLS was also conducted.

RESULTS

Mean patient age was 63.1 years. The median operating time was 246 min and median estimated blood loss was 100 mL. Thirty-two patients underwent subsegmentectomy, 18 monosegmentectomies, 25 bisegmentectomies, and 25 major hepatectomies. One patient (1.0%) required conversion to open surgery. Five patients (5%) experienced postoperative major complications, and no mortalities occurred. Median length of hospital stay was 3 days. R0 resection was achieved in 93.4% of the malignant cases. The learning curve consisted of three stages; there were no significant differences in operative time, transfusion rate, or complication rate among the three groups. Postoperative complications were similar in each group despite an increase in surgical difficulty scores. The learning effect was highlighted by significantly shorter hospital stays in cohorts I, II, and III, respectively. The included systematic review suggested that the learning curve for RLS is similar to, or shorter, than that of laparoscopic liver surgery.

CONCLUSIONS

In our experience, RLS has achieved good clinical results, albeit in the short term. Standardization of training leads to increasing proficiency in RLS with reduced blood loss and low complication rates even in more advanced liver resections. Our study suggests that a minimum of 30 low-to-moderate difficulty robotic procedures should be performed before proceeding to more difficult resections.

[Robotics in Liver Surgery - Tips and Tricks]

Since minimally invasive liver surgery has proven benefits over open surgery, this technique should also be implemented more broadly in Germany. With the dramatic development in minimally invasive and robotic liver surgery, this approach has been established in recent years. Most recent analyses suggest lower complication rates, blood loss and hospital stay compared to open and laparoscopic liver surgery. In contrast to laparoscopic surgery, the technical setting of robotic liver surgery is widely independent of the type of resection. The laparoscopic and robotic technologies should be considered to be equal at the moment, although most recent analyses even suggest additional advantages of robotic over laparoscopic liver surgery. Moreover, robotics has a greater potential for technical refinements, including the inclusion of artificial intelligence and machine learning. Most steps can be transferred from open and laparoscopic liver surgery, but a dissection device such as the CUSA has not yet been developed. Consequently, different techniques have been reported for parenchymal transsection. Due to the special technical features of robotic surgery, intensive training programs should be used prior to the establishment of a robotic liver surgery program.

Robot-assisted minimally invasive liver surgery in elderly patients: A single-centre, propensity score- matched study

BACKGROUND

The aim was to evaluate the short-term results of robot-assisted minimally invasive liver surgery(Robot-assisted liver surgery (RLS)) in elderly patients.

METHODS

Between November 2019 and July 2022, RLS was performed on 100 consecutive patients. Patients were divided into a middle-aged group (Group1:＜75years) and an elderly group(Group2:≧75years). A propensity score matching(PSM) analysis with a ratio of 1:1 was performed.

RESULTS

After PSM, there were 28 patients in each group. There were no significant differences in clinicopathologic characteristics, type of resection and intraoperative variables. Postoperative complications and length of hospital stay were comparable in Groups 1 and 2. In a comparison between minor and major hepatectomy in Group 2, there were no significant differences in any of the factors.

CONCLUSIONS

The study showed that RLS for patients over 75years had similar short-term outcomes as for younger patients down to middle-aged, especially the risk of perioperative complications was comparable.

Enhanced recovery for liver transplantation: recommendations from the 2022 International Liver Transplantation Society consensus conference

There is much controversy regarding enhanced recovery for recipients of liver transplants from deceased and living donors. The objectives of this Review were to summarise current knowledge on individual enhanced recovery elements on short-term outcomes, identify key components for comprehensive pathways, and create internationally accepted guidelines on enhanced recovery for liver-transplant recipients. The ERAS4OLT.org collaborative partnered by the International Liver Transplantation Society performed systematic literature reviews on the effect of 32 relevant enhanced perioperative recovery elements on short-term outcomes, and global specialists prepared expert statements on deceased and living donor liver transplantation. The Grading Recommendations, Assessment, Development and Evaluations approach was used for rating of quality of evidence and grading of recommendations. A virtual international consensus conference was held in January, 2022, in which results were presented, voted on by the audience, and discussed by an independent international jury of eight members, applying the Danish model of consensus. 273 liver transplantation specialists from 30 countries prepared expert statements on elements of enhanced recovery for liver transplantation based on the systematic literature reviews. The consensus conference yielded 80 final recommendations, covering aspects of enhanced recovery for preoperative assessment and optimisation, intraoperative surgical and anaesthetic conduct, and postoperative management for the recipients of liver transplants from both deceased and living donors, and for the living donor. The recommendations represent a comprehensive overview of the relevant elements and areas of enhanced recovery for liver transplantation. These internationally established guidelines could direct the development of enhanced recovery programmes worldwide, allowing adjustments according to local resources and practices.

Robotic Distal Pancreatectomy, a Novel Standard of Care? Benchmark Values for Surgical Outcomes from 16 International Expert Centers

BACKGROUND AND OBJECTIVE

Robotic distal pancreatectomy (DP) is an emerging attractive approach, but its role compared to laparoscopic or open surgery remains unclear. Benchmark values are novel and objective tools for such comparisons. The aim of this study was to identify benchmark cutoffs for many outcome parameters for DP with or without splenectomy beyond the learning curve.

METHODS

This study analyzed outcomes from international expert centers from patients undergoing robotic DP for malignant or benign lesions. After excluding the first 10 cases in each center to reduce the effect of the learning curve, consecutive patients were included from the start of robotic DP up to June 2020. Benchmark patients had no significant comorbidities. Benchmark cutoff values were derived from the 75th or the 25th percentile of the median values of all benchmark centers. Benchmark values were compared to a laparoscopic control group from four high-volume centers and published open DP landmark series.

RESULTS

Sixteen centers contributed 755 cases, whereof 345 benchmark patients (46%) were included the analysis. Benchmark cut-offs included: operation time ≤300min, conversion rate ≤3%, clinically relevant POPF ≤32%, 3 months major complication rate ≤26.7% and lymph node retrieval ≥9. The CCI® at 3 months was ≤8.7 without deterioration thereafter. Compared to robotic DP, laparoscopy had significantly higher conversion rates (5x) and overall complications, while open DP was associated with more blood loss and longer hospital stay.

CONCLUSION

This first benchmark study demonstrates that robotic DP provides superior postoperative outcomes compared to laparoscopic and open DP. Robotic DP may be expected to become the approach of choice in minimally invasive DP.

Robotic distal pancreatectomy, a novel standard of care? First benchmark values for surgical outcomes from 14 international expert centers

Objective

Robotic distal pancreatectomy (DP) is emerging as the preferred treatment for body and tail tumors of the pancreas. To enable conclusive comparisons with the standard open or laparoscopic approaches and robotic surgery among centers, novel benchmark outcome values are urgently needed. Therefore, the aim of this study was to identify benchmark values from expert centers beyond the learning curve.

Methods

This multicenter study analyzed outcomes from consecutive patients undergoing robotic DP for resectable malignant or benign lesions from 14 international expert centers. After the learning curve, defined as the first 10 cases of robotic DP, all consecutive patients were included from the start of the program up to June 2020 with a minimum follow-up of 1 year. Benchmark patients were those without significant comorbidities including obesity (BMI >35 kg/m2) cardiac disease, chronic pulmonary disease.

Benchmark cutoff values were derived from the 75th or the 25th percentile of the median values of all benchmark centers.

Results

After reaching the learning curve, 289 (47%) of a total of 614 consecutive patients qualified as benchmark cases. The proportion of benchmark patients varied between 24%-64% per center. Benchmark cut-offs showed a low 6 month- postoperative mortality (<0.6%), but high overall morbidity (<58.3%). Benchmark cutoffs for operative time (<300 min), conversion rate (<3%), clinically relevant pancreatic fistulas (<26.9%), CCI at 90-days (<14.8), hospital stay (<7 days) and readmission rate (<22.9%). Benchmark cut-offs for complications remained unchanged after 3 months follow-up. For ductal adenocarcinoma benchmark cutoffs for number of lymph nodes were > 19 with an R0 resection rate of > 85%, and an overall survival of >86% and >52% after 1- and 5-years, respectively. Centers with a low cohort of benchmark patients (more difficult cases) had less clinically relevant pancreatic fistula (9% vs. 23%) and less overall complications (32% vs. 48%).

Conclusion

This benchmark analysis sets novel reference values for robotic DP, indicating favorable outcomes as compared to laparoscopic and open DP. These references values may serve for quality control of surgery in centers embarking in robotic DP, and include the procedure in the standard of care.

Robotic Revision of Hepaticojejunostomy for Benign Biliary Stricture

Surgical revision of biliary enteric anastomoses (BEA) can be a challenging undertaking and a robotic platform may provide advantages that address many of the technical obstacles. We present our technical approach and outcomes for patients undergoing robotic revision of BEA for benign strictures. A retrospective review was performed for robot-assisted benign BEA revision at our institution. Operative details, perioperative metrics, and outcomes are reported. Four patients underwent anastomotic revision following previously failed non-operative management. There were no intraoperative complications, mean length of stay was 4-days, and all patients experienced resolution of presenting clinical signs and symptoms. No patients required reoperation and there was no mortality. Postoperative outcomes were consistent with findings reported for other interventional modalities. Based on our experience we conclude robotic intervention in this context is safe and improves the technical feasibility of this complex procedure.

Robotic liver resection in Denmark: Report of the first 50 cases at Rigshospitalet Copenhagen

While most centers around the globe still consider open hepatic resection as the standard, innovative centers step in light of future developments of the robotic platform forward and introduce a robotic liver program while skipping the laparoscopic approach for its technological flaws. This applies also for our Department of Surgery and Transplantation at Rigshospitalet, Copenhagen University Hospital in Denmark. We herewith present as-to our best knowledge-the first center in Scandinavia our experience with the initial 50 robotic liver resections.

Learning Curves in Open, Laparoscopic, and Robotic Pancreatic Surgery: A Systematic Review and Proposal of a Standardization

Objective

To depict and analyze learning curves for open, laparoscopic, and robotic pancreatoduodenectomy (PD) and distal pancreatectomy (DP).

Background

Formal training is recommended for safe introduction of pancreatic surgery but definitions of learning curves vary and have not been standardized.

Methods

A systematic search on PubMed, Web of Science, and CENTRAL databases identified studies on learning curves in pancreatic surgery. Primary outcome was the number needed to reach the learning curve as defined by the included studies. Secondary outcomes included endpoints defining learning curves, methods of analysis (statistical/arbitrary), and classification of learning phases.

Results

Out of 1115 articles, 66 studies with 14,206 patients were included. Thirty-five studies (53%) based the learning curve analysis on statistical calculations. Most often used parameters to define learning curves were operative time (n = 51), blood loss (n = 17), and complications (n = 10). The number of procedures to surpass a first phase of learning curve was 30 (20-50) for open PD, 39 (11-60) for laparoscopic PD, 25 (8-100) for robotic PD (P = 0.521), 16 (3-17) for laparoscopic DP, and 15 (5-37) for robotic DP (P = 0.914). In a three-phase model, intraoperative parameters improved earlier (first to second phase: operating time -15%, blood loss -29%) whereas postoperative parameters improved later (second to third phase: complications -46%, postoperative pancreatic fistula -48%). Studies with higher sample sizes showed higher numbers of procedures needed to overcome the learning curve (rho = 0.64, P < 0.001).

Conclusions

This study summarizes learning curves for open-, laparoscopic-, and robotic pancreatic surgery with different definitions, analysis methods, and confounding factors. A standardized reporting of learning curves and definition of phases (competency, proficiency, mastery) is desirable and proposed.

Prehabilitation in patients undergoing colorectal surgery fails to confer reduction in overall morbidity: results of a single-center, blinded, randomized controlled trial

BACKGROUND

Currently, there are solely weak recommendations in the enhanced recovery after surgery (ERAS) protocol regarding the role of preoperative physical activity and prehabilitation in patients undergoing colorectal surgery. Studies in heterogenous groups showed contradictory results regarding the impact of prehabilitation on the reduction of postoperative complications. The aim of this study was to assess the impact of prehabilitation on postoperative complications in patients undergoing colorectal surgery within an ERAS protocol.

METHODS

Between July 2016 and June 2019, a single-center, blinded, randomized controlled trial designed to test whether physiotherapeutic prehabilitation vs. normal physical activities prior to colorectal surgery may decrease morbidity within a stringent ERAS protocol was carried out. The primary endpoint was postoperative complications assessed by Comprehensive Complications Index (CCI®). Primary and secondary endpoints for both groups were analyzed and compared.

RESULTS

A total of 107 patients (54 in the prehabilitation enhanced recovery after colorectal surgery [pERACS] group and 53 in the control group) were included in the study and randomized. Dropout rate was 4.5% (n = 5). Baseline characteristics were comparable between the pERACS and control groups. The percentage of colorectal adenocarcinoma was low in both groups (pERACS 32% vs. control 23%, p = 0.384). Almost all patients underwent minimally invasive surgery in both groups (96% vs. 98%, p = 1.000). There was no between-group difference in the primary outcome, as the mean CCI at 30-day postoperative in the pERACS group was 18 (SD 0-43) compared to 15 (SD 0-49) in the control group (p = 0.059). Secondary outcome as complications assessed according to Clavien-Dindo, length of hospital stay, reoperation rate, and mortality showed no difference between both groups.

CONCLUSIONS

Routine physiotherapeutic prehabilitation has no additional benefit for patients undergoing colorectal surgery within an ERAS protocol.

TRIAL REGISTRATION

ClinicalTrial.gov: ID: NCT02746731; Institution Ethical Board Approval: KEK-ZH Nr. 2016-00,229.

Impact of enhanced recovery protocols after pancreatoduodenectomy: meta-analysis

BACKGROUND

This individual-patient data meta-analysis investigated the effects of enhanced recovery after surgery (ERAS) protocols compared with conventional care on postoperative outcomes in patients undergoing pancreatoduodenectomy.

METHODS

The Cochrane Library, MEDLINE, Embase, Scopus, and Web of Science were searched systematically for articles reporting outcomes of ERAS after pancreatoduodenectomy published up to August 2020. Comparative studies were included. Main outcomes were postoperative functional recovery elements, postoperative morbidity, duration of hospital stay, and readmission.

RESULTS

Individual-patient data were obtained from 17 of 31 eligible studies comprising 3108 patients. Time to liquid (mean difference (MD) -3.23 (95 per cent c.i. -4.62 to -1.85) days; P < 0.001) and solid (-3.84 (-5.09 to -2.60) days; P < 0.001) intake, time to passage of first stool (MD -1.38 (-1.82 to -0.94) days; P < 0.001) and time to removal of the nasogastric tube (3.03 (-4.87 to -1.18) days; P = 0.001) were reduced with ERAS. ERAS was associated with lower overall morbidity (risk difference (RD) -0.04, 95 per cent c.i. -0.08 to -0.01; P = 0.015), less delayed gastric emptying (RD -0.11, -0.22 to -0.01; P = 0.039) and a shorter duration of hospital stay (MD -2.33 (-2.98 to -1.69) days; P < 0.001) without a higher readmission rate.

CONCLUSION

ERAS improved postoperative outcome after pancreatoduodenectomy. Implementation should be encouraged.

Robotic Resection of Gallbladder Cancer: A Single-Center Retrospective Comparative Study to Open Resection

BACKGROUND

Minimally invasive surgery is gaining support for resection of gallbladder cancer (GBC). This study aims to compare operative and early outcomes of robotic resection (RR) to open resection (OR) from a single institution performing a high volume of robotic HPB surgery.

METHODS

Twenty patients with GBC underwent RR from January 2013 to August 2019. Outcomes were compared to a historical control of 23 patients with OR. Radical cholecystectomy for suspected GBC and completion operations for incidental GBC after routine cholecystectomy were both included.

RESULTS

Robotic resection had lower blood loss compared to OR (150 vs 350 mL, P = .002) and shorter postoperative length of stay (2.5 vs 6 days, P < .001), while median operative time was similar (193 vs 208 min, P = .604). There were no statistical differences in 30-day major complications or readmissions. No 30-day mortalities occurred. There was no statistical difference in survival trend (P = .438) or median lymph node harvest (5 vs 3, P = .189) for RR compared to OR.

CONCLUSION

Robotic resection of GBC is safe and efficient, with lower length of hospital stay and blood loss compared to OR. Technical benefits of robotic-assisted surgery may prove advantageous though larger studies are still needed.

Robotic-assisted completion cholecystectomy: A safe and effective approach to a challenging surgical scenario - A single center retrospective cohort study

BACKGROUND

Reoperation following a previous subtotal or aborted cholecystectomy presents a challenging surgical scenario that has traditionally required an open completion cholecystectomy. The aim of this study was to describe an institutional experience with a robotic-assisted approach to completion cholecystectomy.

METHODS

A database was retrospectively audited to identify all patients who underwent robotic-assisted cholecystectomy performed by two hepatopancreatobiliary surgeons at a single centre from 2010 to 2019.

RESULTS

Twenty six patients who underwent a robotic-assisted completion cholecystectomy were identified. Median operative time was 142 min (48-247 min) with a blood loss of 50 cc (0-500 cc). Minor complications (Clavien-Dindo ≤ II 90 days) occurred in three patients (11.5%) with no major complication or mortality reported. Median hospital length of stay was 1 day (0-6 days) with one patient readmitted.

CONCLUSION

This study represents to our knowledge the largest series of robotic-assisted completion cholecystectomies to date. The robotic approach appears to be a safe and effective procedure associated with a low morbidity and high success rate.

Prehabilitation in patients undergoing colorectal surgery fails to confer reduction in overall morbidity: Results of a single-center, single-blinded, randomized controlled trial

Objective

Patients undergoing major surgery are prone to a functional decline due to the impairment of muscle, cardiorespiratory and neurological function as a response to surgical stress. Currently, there are solely weak recommendations in the ERAS protocol regarding the role of preoperative physical activity and prehabilitation in patients undergoing colorectal surgery. Studies in heterogenous cohorts showed contradictory results regarding the impact of prehabilitation on the reduction of postoperative complications. This randomized controlled trial assesses the impact of prehabilitation on postoperative complications in patients undergoing colorectal surgery within an ERAS protocol.

Methods

Between July 2016 and June 2019, a single-center, single-blinded , randomized controlled trial designed to test whether physiotherapeutic prehabilitation vs. normal physical activities prior to colorectal surgery may decrease morbidity within a stringent ERAS protocol was carried out. The primary endpoint was postoperative complications assessed by Comprehensive Complications Index (CCI®). Primary and secondary endpoints for both groups were analyzed and compared.

Results

A total of 107 patients (54 in the pERACS and 53 in the control cohort) were included in the study and randomized. Dropout rate was 4.5% (n = 5). Mean age (SD) in the control cohort was 65 (29–86) and 66 (24–90) years in pERACS cohort. The pERACS cohort contained more female patients (40% vs. 55%, p = 0.123) and a higher percentage of colorectal adenocarcinoma (32% vs. 23%, p = 0.384) although not significant. Almost all patients underwent minimally invasive surgery in both cohorts (96% vs 98%, p = 1.000). There was no between-cohort difference in the primary outcome measure 30-day Comprehensive Complications Index (15 [0 – 49] vs. 18 [0 – 43], p = 0.059). Secondary outcome as complications assessed according to Clavien-Dindo, length of hospital stay, reoperation rate and mortality showed no difference between both cohorts.

Conclusion

Routine physiotherapeutic prehabilitation cannot be recommended for patients undergoing colorectal surgery within an ERAS protocol (Grade A recommendation). To eliminate other confounders like geographical difference or difference in surgical technique, further multicenter RCTs are needed.

Association of a prehabilitation program with anxiety and depression before colorectal surgery: a post hoc analysis of the pERACS randomized controlled trial

PURPOSE

Hospital-associated anxiety and depression are major preoperative stressors and common in colorectal cancer surgery and major abdominal surgery. The prehabilitation Enhanced Recovery After Colorectal Surgery (pERACS) study is a single-center, single-blinded randomized controlled trial (RCT) evaluating the effect of a structured prehabilitation program. We evaluate within this RCT the association of a prehabilitation program with anxiety and depression before colorectal surgery.

METHODS

Treatment allocation randomized and single-blinded. Regardless of group allocation, patients were treated according to our institutional Enhanced Recovery After Surgery (ERAS) protocol. Inclusion criteria consisted of adult patients suffering from colorectal disease requiring surgical treatment and who were treated according to the ERAS protocol. Anxiety and depression scores were assessed at baseline and at admission according to the Hospital Anxiety and Depression Scale (HADS), with its subcomponents for depression (HADS-D) and for anxiety (HADS-A).

RESULTS

A total of 23 patients randomized to prehabilitation (mean age: 64.8±11.5 years) and 25 patients randomized to the control group (64.0±11.9 years) were included. There was no statistically significant difference in HADS-Anxiety improvement (Prehabilitation: -1.7±2.8 points vs. control: -0.4±3.4 points, p=0.132). Similarly, the difference in HADS-Depression improvement among the prehabilitation (1.0±2.4 points) and control (-0.3 ± 4.0 points) groups (p = 0.543) was non-significant. Clinically meaningful improvement in anxiety (60.9%/40.0%, p=0.149) and depression (34.8%/20.0%, p=0.250) was similar among the groups.

CONCLUSION

In a post hoc analysis of a randomized trial, prehabilitation had no effect on preoperative reduction of anxiety and depression measures.

TRIAL REGISTRATION NUMBER

Clinicaltrials.gov NCT02746731. Date of registration: April 21, 2016.

Multimodal treatment strategies for colorectal liver metastases

Colorectal cancer is the third most common cancer worldwide. Half of CRC patients develop liver metastases during the course of the disease, with a 5-year survival rate close to zero in the absence of therapy. Surgical resection remains the only possible curative option, and current guidelines recommend adjuvant chemotherapy, resulting in a 5-year survival rate exceeding 50%. Neoadjuvant systemic therapy is not indicated in cases with simple resection but should be offered to all patients with extensive bilobar disease. Personalised systemic treatment is essential to convert upfront non-resectable lesions to resectable ones. Anatomical resections, non-anatomical resections and two-stage hepatectomies can be performed though open or minimally invasive (laparoscopic or robotic) surgery. The extent of a hepatic resection is limited by the risk of postoperative liver failure due to a too small liver remnant, inflow or outflow obstruction or insufficient biliary drainage. About 75% of patients are diagnosed with non-resectable liver metastases not amenable to a standard upfront resection. In recent years, effective therapeutic approaches have revolutionised liver surgery and new strategies have enabled the conversion of primarily non-resectable metastatic disease for resection. These strategies include oncological and surgical therapies, as well as combinations of the two. From an oncological perspective, colorectal liver metastases&nbsp; may be treated by systemic chemotherapy or immunotherapy, or selective intra-hepatic arterial infusion chemotherapy, depending on the extent of the disease and the mutational status. In surgery, we often apply two-stage strategies using portal vein occlusion, such as portal vein embolisation or ligation, or complex two-stage hepatectomy such as associating liver partition and portal vein ligation for staged hepatectomy. Other additive tools to reach curative resection are tumour ablations (electroporation, microwave or radiofrequency). The role of stereotactic radiation of liver metastases is not yet well defined. Modern radiation techniques, including image guidance, breath hold and gating, were only introduced for a larger patient population in recent years. Therefore, prospective studies with larger patient cohorts are still pending. Over the last decade, liver transplantation has gained increasing attention in selective cases of non-resectable colorectal liver metastases, with promising cohort studies, but definitive recommendations must await the results of ongoing randomised controlled trials. The optimal treatment of patients with colorectal liver metastases requires the timely association of various strategies, and all cases must be discussed at multidisciplinary team conferences. While colorectal liver metastases was a uniformly lethal condition a few decades ago, it has become amenable to curative therapies, with excellent quality of life in many scenarios. This review reports on up-to-date treatment modalities and their combinations in the treatment algorithm of colorectal liver metastases. &nbsp; &nbsp.

When Echinococcus granulosus transmigrates from the liver into the pericardium: a case report

Infection with Echinococcus granulosus is a common helminthic disease worldwide with endemic in a region with high endemic areas in Africa, Asia, Middle East, South America and southern Europe.

We report a rare case of a young patient with cystic echinococcal disease of the liver invading the pericardium. The patient initially presented with life-threatening cardiac tamponade, which resulted in the discovery of the underlying parasitic disease. He successfully underwent en-bloc hepatic pericystectomy and pericardiac resection with closure of the pericardial defect using a xenogeneic patch. After this procedure, he recovered well and had no cardiac complications in the long term. Under treatment with albendazol, the patient showed no signs of recurrent disease.

Cases of complex cystic echinococcosis, which invade adjacent organs or body cavities, often need radical surgery for definitive treatment embedded in a multidisciplinary approach in highly specialized centers.

Pancreatic fistulas following distal pancreatectomy are unrelated to the texture quality of the pancreas

PURPOSE

The relevance of pancreatic texture for pancreatic fistula (POPF) formation after distal pancreatectomy (DP) remains ill defined. Recent POPF definition adjustments and common subjective pancreatic texture assessment are further drawbacks in the investigation of pancreatic texture as a factor for POPF development after DP.

METHODS

The predictive value of pancreatic texture by histologic assessment was investigated for POPF formation after DP, respecting the updated 2016 fistula definition. Histologic evaluation at the resection margin included amount of steatosis, degree of fibrosis, and pancreatic duct size.

RESULTS

A total of 102 patients who underwent DP were included. Thirty-six patients developed POPF. There was no difference in histologic variables in patients with and without POPF. In the univariate analysis, none of the three histologic features showed significant correlation with POPF formation. The ROC (receiver operating characteristic) curve demonstrated poor utility for the grade of steatosis 0.481 ± 0.058 (p = 0.75) and grade of fibrosis 0.466 ± 0.058 (p = 0.57) as predictive factors for POPF formation.

CONCLUSION

Results indicate that pancreatic texture does not predict POPF formation following DP. This is particularly relevant in the context of the increasing use of robotic and laparoscopic approaches for DPs with limited clinical pancreatic texture assessment by palpation.

Current trends in vena cava reconstructive techniques with major liver resection: a systematic review

PURPOSE

Historically, invasion of the inferior vena cava (IVC) represented advanced and often unresectable hepatic disease. With surgical and anesthetic innovations, IVC resection and reconstruction have become feasible in selected patients. This review assesses technical variations in reconstructive techniques and post-operative management.

METHODS

A comprehensive literature search was performed according to PRISMA. Inclusion criteria were (i) peer-reviewed articles in English; (ii) at least three cases; (iii) hepatic IVC resection and reconstruction (January 2015-March 2020). Primary outcomes were reconstructive technique, anti-thrombotic regimen, post-operative IVC patency, and infection. Secondary outcomes included post-operative complications and malignant disease survival.

RESULTS

Fourteen articles were included allowing for investigation of 351 individual patients. Analysis demonstrated significant heterogeneity in surgical reconstructive technique, anti-thrombotic management, and post-operative monitoring of patency. There was increased utilization of ex vivo approaches and decreased use of venovenous bypass compared with previously published reviews.

CONCLUSION

This review of literature published between 2015 and 2020 reveals persistent heterogeneity of hepatic IVC reconstructive techniques and peri-operative management. Increased utilization of ex vivo approaches and decreased use of venovenous bypass point towards improved operative techniques, peri-operative management, and anesthesia. In order to gain evidence for consensus on management, a registry would be beneficial.

Oncologic Outcomes of Robotic Left Pancreatectomy for Pancreatic Adenocarcinoma: A Single-Center Comparison to Laparoscopic Resection

BACKGROUND

Feasibility and safety of robotic surgery for pancreatic disease has been well demonstrated; however, there is scarce literature on long-term oncologic outcomes. We compared perioperative and oncologic outcomes between robotic left pancreatectomy (RLP) and laparoscopic left pancreatectomy (LLP) for pancreatic adenocarcinoma.

METHODS

A retrospective review evaluated left pancreatectomies performed for pancreatic adenocarcinoma from 2009 to 2019 in a tertiary institution. Baseline characteristics, operative and oncologic outcomes were compared between RLP and LLP.

RESULTS

There were 75 minimally invasive left pancreatectomy cases for pancreatic adenocarcinoma identified of which 33 cases were done robotically and 42 laparoscopically. Baseline characteristics demonstrated no difference in gender, age, BMI, T stage, N stage, neoadjuvant, or adjuvant chemotherapy. An analysis of operative variables demonstrated no difference in blood loss, increased duration, and higher lymph node yield with RLP (20 vs 12; P = .0029). Postoperatively, both cohorts had 30% pancreatic fistulas and no difference in complications. There were no differences in length of stay (LOS), 30- or 90-day readmission rates, or 90-day mortality. The analysis of oncologic outcomes demonstrated similar R0 resections (RLP: 72% vs OLP: 67%), recurrence rates (RLP: 36% vs OLP: 41%), and time to recurrence (RLP: 324 vs OLP 218 days). There was increased survival in the RLP cohort that was not significant (32 vs 19 months).

CONCLUSION

This analysis demonstrates RLP is at least equivalent to LLP in perioperative and oncologic outcomes. The significantly higher lymph node yield and trend toward an improved survival suggests oncologic advantage. Randomized controlled studies are needed to clarify benefit.

Attitudes and acceptance of patients undergoing visceral surgery towards an open access electronic medical record - a Swiss-German single-centre study

INTRODUCTION

With the digitalisation of patient medical records, providing patients with free access to their electronic medical record (EMR) has become an important topic of debate in many countries. Recent studies show that the quality of treatment in healthcare may be improved by encouraging patients to take an active part in their care. Providing patients with access to their EMR may also improve the patient-doctor relationship, adherence to treatment and patient satisfaction. In June 2015, the Swiss government passed a law to set the framework for a nationally coordinated EMR system. A major stipulation to this legislation is that patients and doctors must consent to having an open access EMR (oEMR). The aim of this study was to assess patients' attitudes towards an oEMR.

METHODS

Consecutive patients attending the outpatient clinic of our department within two months were included in this study. Patients were asked to complete a questionnaire consisting of 43 items, including amongst others disease characteristics, their expectations regarding an oEMR and its implementation. This study was approved by the ethics committee of the Canton Zurich (BASEC-Nr. Req-2016-00383).

RESULTS

149 patients were included with a mean age of 52 (standard deviation 17) years. 42% suffered from abdominal diseases (benign or malignant), 26% from hernias, and 17% from anorectal disorders. 76% of the responding patients fully supported an oEMR. Among all items, a higher educational degree (odds ratio [OR] 55, 95% confidence interval [CI] 39-70), patients with general or half-private insurance (OR 10, 95% CI 0.99-100) and patients with suspected cancer (OR 6, 95% CI 0.93-42) were independent predictors for a positive attitude regarding an oEMR on multivariate analysis.

CONCLUSION

To our knowledge, this is the first study conducted in a hospital in the German-speaking part of Switzerland evaluating patients' opinions regarding an oEMR. Overall a large majority of the patients support an oEMR. Patients with cancer, a higher educational degree and general or half-private insured patients were more likely to support an oEMR. An important next step would be to conduct studies investigating opinions of medical professionals during the implementation of an oEMR.

Exercise Improves Outcomes of Surgery on Fatty Liver in Mice: A Novel Effect Mediated by the AMPK Pathway

OBJECTIVE

To investigate whether exercise improves outcomes of surgery on fatty liver, and whether pharmacological approaches can substitute exercising programs.

SUMMARY OF BACKGROUND DATA

Steatosis is the hepatic manifestation of the metabolic syndrome, and decreases the liver's ability to handle inflammatory stress or to regenerate after tissue loss. Exercise activates adenosine monophosphate-activated kinase (AMPK) and mitigates steatosis; however, its impact on ischemia-reperfusion injury and regeneration is unknown.

METHODS

We used a mouse model of simple, diet-induced steatosis and assessed the impact of exercise on metabolic parameters, ischemia-reperfusion injury and regeneration after hepatectomy. The same parameters were evaluated after treatment of mice with the AMPK activator 5-aminoimidazole-4-carboxamide ribonucleotide (AICAR). Mice on a control diet served as age-matched controls.

RESULTS

A 4-week-exercising program reversed steatosis, lowered insulin levels, and improved glucose tolerance. Exercise markedly enhanced the ischemic tolerance and the regenerative capacity of fatty liver. Replacing exercise with AICAR was sufficient to replicate the above benefits. Both exercise and AICAR improved survival after extended hepatectomy in mice challenged with a Western diet, indicating protection from resection-induced liver failure.

CONCLUSIONS

Exercise efficiently counteracts the metabolic, ischemic, and regenerative deficits of fatty liver. AICAR acts as an exercise mimetic in settings of fatty liver disease, an important finding given the compliance issues associated with exercise. Exercising, or its substitution through AICAR, may provide a feasible strategy to negate the hepatic consequences of energy-rich diet, and has the potential to extend the application of liver surgery if confirmed in humans.

Perioperative omega-3 fatty acids fail to confer protection in liver surgery: Results of a multicentric, double-blind, randomized controlled trial

BACKGROUND & AIMS

In a variety of animal models, omega-3 polyunsaturated fatty acids (Ω3-FAs) conferred strong protective effects, alleviating hepatic ischemia/reperfusion injury and steatosis, as well as enhancing regeneration after major tissue loss. Given these benefits along with its safety profile, we hypothesized that perioperative administration of Ω3-FAs in patients undergoing liver surgery may ameliorate the postoperative course. The aim of this study was to investigate the perioperative use of Ω3-FAs to reduce postoperative complications after liver surgery.

METHODS

Between July 2013 and July 2018, we carried out a multicentric, double-blind, randomized, placebo-controlled trial designed to test whether 2 single intravenous infusions of Omegaven® (Ω3-FAs) vs. placebo may decrease morbidity. The primary endpoints were postoperative complications by severity (Clavien-Dindo classification) integrated within the comprehensive complication index (CCI).

RESULTS

A total of 261 patients (132 in the Omegaven and 129 in the placebo groups) from 3 centers were included in the trial. Most cases (87%, n = 227) underwent open liver surgery and 56% (n = 105) were major resections (≥3 segments). In an intention-to-treat analysis including the dropout cases, the mortality rate was 4% and 2% in the Omegaven and placebo groups (odds ratio0.40;95% CI 0.04-2.51; p = 0.447), respectively. Any complications and major complications (Clavien-Dindo ≥ 3b) occurred in 46% vs. 43% (p = 0.709) and 12% vs. 10% (p = 0.69) in the Omegaven and placebo groups, respectively. The mean CCI was 17 (±23) vs.14 (±20) (p = 0.417). An analysis excluding the dropouts provided similar results.

CONCLUSIONS

The routine perioperative use of 2 single doses of intravenous Ω3-FAs (100 ml Omegaven) cannot be recommended in patients undergoing liver surgery (Grade A recommendation).

LAY SUMMARY

Despite strong evidence of omega-3 fatty acids having liver-directed, anti-inflammatory and pro-regenerative action in various rodent models, 2 single omega-3 fatty acid infusions given to patients before and during liver surgery failed to reduce complications. Because single omega-3 fatty acid infusions failed to confer liver protection in this trial, they cannot currently be recommended.

TRIAL REGISTRATION

ClinicalTrial.gov: ID: NCT01884948; Institution Ethical Board Approval: KEK-ZH-Nr. 2010-0038; Swissmedic Notification: 2012DR3215.

Allocation of liver grafts worldwide - Is there a best system?

BACKGROUND & AIMS

An optimal allocation system for scarce resources should simultaneously ensure maximal utility, but also equity. The most frequent principles for allocation policies in liver transplantation are therefore criteria that rely on pre-transplant survival (sickest first policy), post-transplant survival (utility), or on their combination (benefit). However, large differences exist between centers and countries for ethical and legislative reasons. The aim of this study was to report the current worldwide practice of liver graft allocation and discuss respective advantages and disadvantages.

METHODS

Countries around the world that perform 95 or more deceased donor liver transplantations per year were analyzed for donation and allocation policies, as well as recipient characteristics.

RESULTS

Most countries use the model for end-stage liver disease (MELD) score, or variations of it, for organ allocation, while some countries opt for center-based allocation systems based on their specific requirements, and some countries combine both a MELD and center-based approach. Both the MELD and center-specific allocation systems have inherent limitations. For example, most countries or allocation systems address the limitations of the MELD system by adding extra points to recipient's laboratory scores based on clinical information. It is also clear from this study that cancer, as an indication for liver transplantation, requires special attention.

CONCLUSION

The sickest first policy is the most reasonable basis for the allocation of liver grafts. While MELD is currently the standard for this model, many adjustments were implemented in most countries. A future globally applicable strategy should combine donor and recipient factors, predicting probability of death on the waiting list, post-transplant survival and morbidity, and perhaps costs.

LAY SUMMARY

An optimal allocation system for scarce resources should simultaneously ensure maximal utility, but also equity. While the model for end-stage liver disease is currently the standard for this model, many adjustments were implemented in most countries. A future globally applicable strategy should combine donor and recipient factors predicting probability of death on the waiting list, post-transplant survival and morbidity, and perhaps costs.

Appendectomy in Switzerland: how is it done?

More than 10,000 appendectomies are performed every year in Switzerland. The aim of this study was to investigate the treatment strategy for appendicitis among Swiss surgeons with particular interest in laparoscopic technique, method of appendiceal stump closure, and abdominal lavage. We performed an anonymous survey among 540 members of the Swiss Surgical Society. Technical details and differences between the surgical procedures in adults and children as well as in complicated and non-complicated appendicitis were investigated. The overall response rate was 45% (n = 243). 78% of the surgeons perform laparoscopic appendectomies in children and 95% in adult patients. Only 3% use a single incision site technique. Surgeons consider pus or stool in the abdomen (94%), an abscess (86%) or perforation of the appendix (82%), but not an inflamed appendiceal base (16%) as complicated appendicitis. 41% of surgeons use endoloops, 36% a stapling device, and 20% polymeric clips in non-complicated appendicitis for appendiceal stump closure. However, 82% of the surgeons use a stapler in complicated appendicitis. Most (76%) of surgeons do not plunge the appendiceal stump. 24% of surgeons lavage the abdomen with > 1 L of fluid independent of the intraabdominal finding. Most Swiss surgeons perform multiport laparoscopic appendectomies. Endoloops and staplers are mostly used for appendiceal stump closures in uncomplicated appendicitis, and staplers in complicated appendicitis. Only a minor part of surgeons plunge the appendiceal stump or perform routine abdominal lavage.

Yes-associated protein promotes early hepatocyte cell cycle progression in regenerating liver after tissue loss

The ability of the liver to restore its original volume following tissue loss has been associated with the Hippo‐YAP1 pathway, a key controller of organ size. Yes‐associated protein 1 (YAP1)—a growth effector usually restrained by Hippo signaling—is believed to be of particular importance; however, its role in liver regeneration remains ill‐defined. To explore its function, we knocked down YAP1 prior to standard 70%‐hepatectomy (sHx) using a hepatocyte‐specific nanoformulation. Knockdown was effective during the major parenchymal growth phase (S‐phase/M‐phase peaks at 32 hours/48 hours post‐sHx). Liver weight gain was completely suppressed by the knockdown at 32 hours, but was reaccelerated toward 48 hours. Likewise, proliferative markers, Ccna2/b2 and YAP1 target gene expression were downregulated at 32 hours, but re‐elevated at 48 hours post‐sHx. Nonetheless, knockdown slightly compromised survival after sHx. When assessing a model of resection‐induced liver failure (extended 86%‐hepatectomy, eHx) featuring deficient S‐ and M‐phase progression, YAP1 was not induced at 32 hours, but upregulated at 48 hours post‐eHx, confirming its dissociation from M‐phase regulation. Therefore, YAP1 is vital to push hepatocytes into cycle and through the S‐phase, but is not required for further cell cycle progression during liver regeneration. The examination of YAP1 in human livers suggested its function is conserved in the regenerating mammalian liver.

Systematic review and meta-analysis of postoperative pancreatic fistula rates using the updated 2016 International Study Group Pancreatic Fistula definition in patients undergoing pancreatic resection with soft and hard pancreatic texture

BACKGROUND

In 2016, the International Study Group of Pancreatic Fistula (ISGPS) proposed an updated definition for postoperative pancreatic fistula (POPF). Pancreas texture (PT) is an established risk factor of POPF. The definition of soft vs. hard texture, however, remains elusive.

METHODS

A systematic search was performed to identify PT definitions and a meta-analysis linking POPF to PT using the updated ISGPS definition.

RESULTS

122 studies including 22 376 patients were identified. Definition criteria for PT varied among studies and most classified PT in hard and soft based on intraoperative subjective assessment. The total POPF rate (pooled grades B and C) after pancreatoduodenectomy was 14.5% (n = 10 395) and 15.5% (n = 3767) after distal pancreatectomy. In pancreatoduodenectomy, POPF rate was higher in soft compared to hard pancreas (RR, 4.4, 3.3 to 6.1; p < 0.001; n = 6393), where PT grouped as soft and hard. No data were available for intermediate PT.

CONCLUSION

The reported POPF rates may be used in planning future prospective studies. A widely accepted definition of PT is lacking and a correlation with the risk of POPF is based on subjective evaluation, which is still acceptable. Classification of PT into 2-groups is more reasonable than classification into 3-groups.

Assessing the Value of Prehabilitation in Patients Undergoing Colorectal Surgery According to the Enhanced Recovery After Surgery (ERAS) Pathway for the Improvement of Postoperative Outcomes: Protocol for a Randomized Controlled Trial

Background

A key element in the postoperative phase of the standardized Enhanced Recovery After Surgery (ERAS) treatment pathways is mobilization. Currently, there are no recommendations in the ERAS guidelines for preoperative physical activity. Patients undergoing major surgery are prone to functional decline due to the impairment of muscle, cardiorespiratory, and neurological function as a response to surgical stress. It has been shown that preoperative physical training reduces postoperative complications. To date, there are limited studies that investigate preoperative physical training combined with ERAS.

Objective

The aim of this study is to assess the impact of tailored physical training prior to colorectal surgery conducted according to an ERAS protocol on overall morbidity. This study proposes the initial hypothesis that 3-6 weeks of prehabilitation before elective colorectal surgery may improve postoperative outcome and reduce complication rates, assessed using the Comprehensive Complication Index. The primary objective is to evaluate overall morbidity due to postoperative complications. Additionally, complications are assessed according to the Clavien-Dindo classification, length of stay, readmission rate, mortality rate, and treatment-related costs.

Methods

The prehabilitation Enhanced Recovery After colorectal Surgery (pERACS) study is a single-center, single-blinded prospective randomized controlled trial. Patients scheduled for colorectal resections are randomly assigned either to the prehabilitation group or the control group. All patients are treated with the ERAS pathway for colorectal resections according to a standardized study schedule. Sample size calculation performed by estimating a clinically relevant 25% reduction of postoperative complications (alpha=.05, power 80%, dropout rate of 10%) resulted in 56 randomized patients per group.

Results

Following ethical approval of the study protocol, the first patient was included in June 2016. At this time, a total of 40 patients have been included; 27 patients terminated the study by the end of March 2017. Results are expected to be published in 2018.

Conclusions

The pERACS trial is a single-center, single-blinded prospective randomized controlled trial to assess the impact of tailored physical training prior to colorectal surgery, conducted according to an ERAS protocol, in order to evaluate overall morbidity.

Trial Registration

Clinicaltrials.gov NCT02746731; https://clinicaltrials.gov/ct2/show/NCT02746731 (Archived by WebCite at http://www.webcitation.org/6tzblGwge)

PTEN Down-Regulation Promotes β-Oxidation to Fuel Hypertrophic Liver Growth After Hepatectomy in Mice

In regenerating liver, hepatocytes accumulate lipids before the major wave of parenchymal growth. This transient, regeneration-associated steatosis (TRAS) is required for liver recovery, but its purpose is unclear. The tumor suppressor phosphatase and tensin homolog (PTEN) is a key inhibitor of the protein kinase B/mammalian target of rapamycin axis that regulates growth and metabolic adaptations after hepatectomy. In quiescent liver, PTEN causes pathological steatosis when lost, whereas its role in regenerating liver remains unknown. Here, we show that PTEN down-regulation promotes liver growth in a TRAS-dependent way. In wild-type mice, PTEN reduction occurred after TRAS formation, persisted during its disappearance, and correlated with up-regulated β-oxidation at the expense of lipogenesis. Pharmacological modulation revealed an association of PTEN with TRAS turnover and hypertrophic liver growth. In liver-specific Pten^-/- mice shortly after induction of knockout, hypertrophic regeneration was accelerated and led to hepatomegaly. The resulting surplus liver mass was functional, as demonstrated by raised survival in a lethal model of resection-induced liver failure. Indirect calorimetry revealed lipid oxidation as the primary energy source early after hepatectomy. The shift from glucose to lipid usage was pronounced in Pten^-/- mice and correlated with the disappearance of TRAS. Partial inhibition of β-oxidation led to persisting TRAS in Pten^-/- mice and abrogated hypertrophic liver growth. PTEN down-regulation may promote β-oxidation through β-catenin, whereas hypertrophy was dependent on mammalian target of rapamycin complex 1.

CONCLUSION

PTEN down-regulation after hepatectomy promotes the burning of TRAS-derived lipids to fuel hypertrophic liver regeneration. Therefore, the anabolic function of PTEN deficiency in resting liver is transformed into catabolic activities upon tissue loss. These findings portray PTEN as a node coordinating liver growth with its energy demands and emphasize the need of lipids for regeneration. (Hepatology 2017;66:908-921).

Constitutive androstane receptor (Car)-driven regeneration protects liver from failure following tissue loss

BACKGROUND & AIMS

Liver can recover following resection. If tissue loss is too excessive, however, liver failure will develop as is known from the small-for-size-syndrome (SFSS). The molecular processes underlying liver failure are ill-understood. Here, we explored the role and the clinical potential of Nr1i3 (constitutive androstane receptor, Car) in liver failure following hepatectomy.

METHODS

Activators of Car, various hepatectomies, Car(-/-) mice, humanized CAR mice, human tissue and ex vivo liver slice cultures were used to study Car in the SFSS. Pathways downstream of Car were investigated by in vivo siRNA knockdown.

RESULTS

Excessive tissue loss causing liver failure is associated with deficient induction of Car. Reactivation of Car by an agonist normalizes all features associated with experimental SFSS. The beneficial effects of Car activation are relayed through Foxm1, an essential promoter of the hepatocyte cell cycle. Deficiency in the CAR-FOXM1 axis likewise is evident in human SFSS. Activation of human CAR mitigates SFSS in humanized CAR mice and improves the culture of human liver slices.

CONCLUSIONS

Impaired hepatic Car-Foxm1 signaling provides a first molecular characterization of liver that fails to recover after tissue loss. Our findings place deficient regeneration as a principal cause behind the SFSS and suggest CAR agonists may bear clinical potential against liver failure.

LAY SUMMARY

The unique regenerative capacity of liver has its natural limits. Following tissue loss that is too excessive, such as through extended resection in the clinic, liver failure may develop. This is known as small-for-size-syndrome (SFSS) and represents the most frequent cause of death due to liver surgery. Here we show that deficient induction of the protein Car, a central regulator of liver function and growth, is a cause of liver failure following extended resection; reactivation of Car through pharmacological means is sufficient to prevent or rescue the SFSS.

Selective portal vein injection for the design of syngeneic models of liver malignancy

Liver metastases are the most frequent cause of death due to colorectal cancer (CRC). Syngeneic orthotopic animal models, based on the grafting of cancer cells or tissue in host liver, are efficient systems for studying liver tumors and their (patho)physiological environment. Here we describe selective portal vein injection as a novel tool to generate syngeneic orthotopic models of liver tumors that avoid most of the weaknesses of existing syngeneic models. By combining portal vein injection of cancer cells with the selective clamping of distal liver lobes, tumor growth is limited to specific lobes. When applied on MC-38 CRC cells and their mouse host C57BL6, selective portal vein injection leads with 100% penetrance to MRI-detectable tumors within 1 wk, followed by a steady growth until the time of death (survival ∼7 wk) in the absence of extrahepatic disease. Similar results were obtained using CT-26 cells and their syngeneic Balb/c hosts. As a proof of principle, lobe-restricted liver tumors were also generated using Hepa1-6 (C57BL6-syngeneic) and TIB-75 (Balb/c-syngeneic) hepatocellular cancer cells, demonstrating the general applicability of selective portal vein injection for the induction of malignant liver tumors. Selective portal vein injection is technically straightforward, enables liver invasion via anatomical routes, preserves liver function, and provides unaffected liver tissue. The tumor models are reproducible and highly penetrant, with survival mainly dependent on the growth of lobe-restricted liver malignancy. These models enable biological studies and preclinical testing within short periods of time.

"A randomized, double-blind study of the effects of omega-3 fatty acids (Omegaven) on outcome after major liver resection"

Background

The body is dependent on the exogenous supply of omega-3 polyunsaturated fatty acids (n3-PUFA). These essential fatty acids are key players in regulating metabolic signaling but also exert anti-inflammatory and anti-carcinogenic properties. The liver is a major metabolic organ involved in fatty acid metabolism. Under experimental conditions, n3-PUFA exert beneficial effect on hepatic steatosis, regeneration and inflammatory insults such as ischemic injury after surgery. Some of these effects have also been observed in human subjects. However, it is unclear whether perioperative administration of n3-PUFA is sufficient to protect the liver from ischemic injury. Therefore, we designed a randomized controlled trial (RCT) assessing n3-PUFA (pre-) conditioning strategies in patients scheduled for liver surgery.

Methods/Design

The Omegaven™ trial is a multi-centric, double-blind, randomized, placebo- controlled trial applying two single doses of Omegaven™ or placebo on 258 patients undergoing major liver resection. Primary endpoints are morbidity and mortality one month after hospital discharge, defined by the Clavien- Dindo classification of surgical complications (Ann Surg 240(2):205–13, 2004) as well as the Comprehensive Complication Index (CCI) (Ann Surg 258(1):1–7, 2013). Secondary outcome variables include length of Intensive Care Unit (ICU) and hospital stay, postoperative liver function tests, fatty acid and eicosanoid concentration, inflammatory markers in serum and in liver tissue. An interim analysis is scheduled after the first 30 patients per randomization group.

Discussion

Long-term administration of n3-PUFA have a beneficial effect on metabolism and hepatic injury. Patients often require surgery without much delay, thus long-term n3-PUFA uptake is not possible. Also, lack of compliance may lead to incomplete n3-PUFA substitution. Hence, perioperative Omegaven™ may provide an easy and controllable way to ensure hepaative application of tic protection.

Trial registration

ClinicalTrial.gov: ID: NCT01884948, registered June 14, 2013; Institution Ethical Board Approval: KEK-ZH-Nr. 2010–0038; Swissmedic Notification: 2012DR3215.

Epidural analgesia and perioperative kidney function after major liver resection

BACKGROUND

Epidural analgesia (EDA) is a common analgesia regimen in liver resection, and is accompanied by sympathicolysis, peripheral vasodilatation and hypotension in the context of deliberate intraoperative low central venous pressure. This associated fall in mean arterial pressure may compromise renal blood pressure autoregulation and lead to acute kidney injury (AKI). This study investigated whether EDA is a risk factor for postoperative AKI after liver surgery.

METHODS

The incidence of AKI was investigated retrospectively in patients who underwent liver resection with or without EDA between 2002 and 2012. Univariable and multivariable analyses were performed including recognized preoperative and intraoperative predictors of posthepatectomy renal failure.

RESULTS

A series of 1153 patients was investigated. AKI occurred in 8·2 per cent of patients and was associated with increased morbidity (71 versus 47·3 per cent; P = 0·003) and mortality (21 versus 0·3 per cent; P <  0·001) rates. The incidence of AKI was significantly higher in the EDA group (10·1 versus 3·7 per cent; P = 0·003). Although there was no significant difference in the incidence of AKI between patients undergoing minor hepatectomy with or without EDA (5·2 versus 2·7 per cent; P = 0·421), a substantial difference in AKI rates occurred in patients undergoing major hepatectomy (13·8 versus 5·0 per cent; P = 0·025). In multivariable analysis, EDA remained an independent risk factor for AKI after hepatectomy (P = 0·040).

CONCLUSION

EDA may be a risk factor for postoperative AKI after major hepatectomy.

ALPPS offers a better chance of complete resection in patients with primarily unresectable liver tumors compared with conventional-staged hepatectomies: results of a multicenter analysis

BACKGROUND

Portal vein occlusion to increase the size of the future liver remnant (FLR) is well established, using portal vein ligation (PVL) or embolization (PVE) followed by resection 4-8 weeks later. Associating liver partition with portal vein ligation for staged hepatectomy (ALPPS) combines PVL and complete parenchymal transection, followed by hepatectomy within 1-2 weeks. ALPPS has been recently introduced but remains controversial. We compare the ability of ALPPS versus PVE or PVL for complete tumor resection.

METHODS

A retrospective review of all patients undergoing ALPPS or conventional staged hepatectomies using PVL or PVE at four high-volume HPB centres between 2003 and 2012 was performed. Patients with primary liver tumors and liver metastases were included. Primary endpoint was complete tumor resection. Secondary endpoints include 90-day mortality, complications, FLR increase, time to resection, and tumor recurrence.

RESULTS

Forty-eight patients with ALPPS were compared with 83 patients with conventional-staged hepatectomies. Eighty-three percent (40/48 patients) of ALPPS patients achieved complete resection compared with 66 % (55/83 patients) in PVE/PVL (odds ratio 3.34, p = 0.027). Ninety-day mortality in ALPPS and PVE/PVL was 15 and 6 %, respectively (p = 0.2). Extrapolated growth rate was 11 times higher in ALPPS (34.8 cc/day; interquartile range (IQR) 26-49) compared with PVE/PVL (3 cc/day; IQR2-6; p = 0.001). Tumor recurrence at 1 year was 54 versus 52 % for ALPPS and PVE/PVL, respectively (p = 0.7).

CONCLUSIONS

This study provides evidence that ALPPS offers a better chance of complete resection in patients with primarily unresectable liver tumors at the cost of a high mortality. The technique is promising but should currently not be used outside of studies and registries.

Systematic review and meta-analysis of feasibility, safety, and efficacy of a novel procedure: associating liver partition and portal vein ligation for staged hepatectomy

BACKGROUND

Associating liver partition and portal vein ligation for staged hepatectomy (ALPPS) is a novel strategy to resect liver tumors despite the small size of the liver remnant. It is an hepatectomy in two stages, with PVL and parenchymal transection during the first stage, which induces rapid growth of the remnant liver exceeding any other technique. Despite high postoperative morbidity and mortality in most reports, the technique was adopted by a number of surgeons.

MATERIALS AND METHODS

This systematic review explores current data regarding the feasibility, safety, and oncologic efficacy of ALPPS; the search strategy has been published online. A meta-analysis of hypertrophy, feasibility (ALPPS stage 2 performed), mortality, complications, and R0 (complete) resection was performed.

RESULTS

A literature search revealed a total of 13 publications that met the search criteria, reporting data from 295 patients. Evidence levels were low, with the highest Oxford evidence level being 2c. The most common indication was colorectal liver metastasis in 203 patients. Hypertrophy in the meta-analysis was 84 %, feasibility (ALPPS stage 2 performed) 97 % (CI 94-99 %), 90-day mortality 11 % (CI 8-16 %), and complications grade IIIa or higher occured in 44 % (CI 38-50 %) of patients. A standardized reporting format for complications is lacking despite the widespread use of the Clavien-Dindo classification. Oncological outcome is not well-documented. The most common topics in the selected studies published were technical feasibility and indications for the procedures. Publication bias due to case-series and single-center reports is common.

CONCLUSION

A systematic exploration of this novel operation with a rigid methodology, such as registry analyses and a randomized controlled trial, is highly advised.

Systematic review and meta-analysis of feasibility, safety, and efficacy of a novel procedure: associating liver partition and portal vein ligation for staged hepatectomy

BACKGROUND

Associating liver partition and portal vein ligation for staged hepatectomy (ALPPS) is a novel strategy to resect liver tumors despite the small size of the liver remnant. It is an hepatectomy in two stages, with PVL and parenchymal transection during the first stage, which induces rapid growth of the remnant liver exceeding any other technique. Despite high postoperative morbidity and mortality in most reports, the technique was adopted by a number of surgeons.

MATERIALS AND METHODS

This systematic review explores current data regarding the feasibility, safety, and oncologic efficacy of ALPPS; the search strategy has been published online. A meta-analysis of hypertrophy, feasibility (ALPPS stage 2 performed), mortality, complications, and R0 (complete) resection was performed.

RESULTS

A literature search revealed a total of 13 publications that met the search criteria, reporting data from 295 patients. Evidence levels were low, with the highest Oxford evidence level being 2c. The most common indication was colorectal liver metastasis in 203 patients. Hypertrophy in the meta-analysis was 84 %, feasibility (ALPPS stage 2 performed) 97 % (CI 94-99 %), 90-day mortality 11 % (CI 8-16 %), and complications grade IIIa or higher occured in 44 % (CI 38-50 %) of patients. A standardized reporting format for complications is lacking despite the widespread use of the Clavien-Dindo classification. Oncological outcome is not well-documented. The most common topics in the selected studies published were technical feasibility and indications for the procedures. Publication bias due to case-series and single-center reports is common.

CONCLUSION

A systematic exploration of this novel operation with a rigid methodology, such as registry analyses and a randomized controlled trial, is highly advised.

Nonsurgical Strategies in Patients With NET Liver Metastases: A Protocol of Four Systematic Reviews

BACKGROUND

Patients diagnosed with neuroendocrine tumors (NETs) with hepatic metastases generally have a worse prognosis as compared with patients with nonmetastasized NETs. Due to tumor location and distant metastases, a surgical approach is often not possible and nonsurgical therapeutic strategies may apply.

OBJECTIVE

The aim of these systematic reviews is to evaluate the role of nonsurgical therapy options for patients with nonresectable liver metastases of NETs.

METHODS

An objective group of librarians will provide an electronic search strategy to examine the MEDLINE, EMBASE, and The Cochrane Library (Cochrane Database of Systematic Reviews, Database of Abstracts of Reviews of Effects, Cochrane Central Register of Controlled Trials [CENTRAL]) databases. There will be no restriction concerning language and publication date. The qualitative and quantitative synthesis of the systematic review will be conducted with randomized controlled trials (RCT), prospective, and retrospective comparative cohort, and case-control studies. Case series will be collected in a separate database and only used for descriptive purposes.

RESULTS

This study is ongoing and presents a protocol of four systematic reviews to assess the role of nonsurgical treatment options in patients with neuroendocrine liver metastases.

CONCLUSIONS

These systematic reviews, performed according to this protocol, will assess the value of noninvasive therapy options for patients with nonresectable liver metastases of NETs in combination with invasive techniques, such as percutaneous liver-directed techniques and local ablation techniques.

TRIAL REGISTRATION

International Prospective Register of Systematic Reviews (PROSPERO): CRD42012002657; http://www.metaxis.com/PROSPERO/full_doc.asp?RecordID=2657 (Archived by WebCite at http://www.webcitation.org/6NDlYi37O); CRD42012002658; http://www.metaxis.com/PROSPERO/full_doc.asp?RecordID=2658 (Archived by WebCite at http://www.webcitation.org/6NDlfWSuD); CRD42012002659; www.metaxis.com/PROSPERO/full_doc.asp?RecordID=2659 (Arichived by Webcite at http://www.webcitation.org/6NDlmWAFM); and CRD42012002660; http://www.metaxis.com/PROSPERO/full_doc.asp?RecordID=2660 (Archived by WebCite at http://www.webcitation.org/6NDmnylzp).

Transplantation and surgical strategies in patients with neuroendocrine liver metastases: protocol of four systematic reviews

Background

Hepatic metastases of neuroendocrine tumors (NETs) are considered a major prognostic factor associated with significantly reduced survival compared to patients without liver metastases. Several surgical and nonsurgical strategies are present to treat resectable and nonresectable liver metastases, some of which have the potential to cure liver mestatases.

Objective

The aims of the four systematic reviews presented in the paper are to determine the effectiveness of liver resection versus nonsurgical treatment of patients with NET liver metastases, to investigate the impact of neoadjuvant and adjuvant treatment options on the tumor-free survival, to assess the role of liver transplantation in patients presenting with unresectable bilateral hepatic metastases, and to evaluate the role of primary tumor resection in presence of unresectable liver metastases.

Methods

Literature search was performed on Medical Literature Analysis and Retrieval System Online, Excerpta Medica Database, and the Cochrane Library (Cochrane Database of Systematic Reviews, Database of Abstracts of Reviews of Effects, and Cochrane Central Register of Controlled Trials). No language restrictions were applied. Randomized controlled trials, prospective and retrospective comparative cohort studies, and case-control studies will be used for the qualitative and quantitative synthesis of the systematic reviews. Case series will be only included in a separate database for descriptive purposes.

Results

This study is ongoing and presents a protocol system of four systematic reviews that will assist in determining the effectiveness of liver resection versus nonsurgical treatment of patients with NET liver metastases. This study is also assumed to investigate the impact of neoadjuvant and adjuvant treatment options on the tumor-free survival, the role of liver transplantation, and the relevance of primary tumor resection in presence of unresectable liver metastasis.

Conclusions

The systematic reviews will show the current evidence based on the effectiveness of surgical strategies in patients with NET liver metastases and serve as basis for clinical practice guidelines.

Trial Registration

The systematic reviews have been prospectively registered with the International Prospective Register of Systematic Reviews: liver resection (CRD42012002652); http://www.crd.york.ac.uk/prospero/display_record.asp?ID=CRD42012002652 (Archived by WebCite at http://www.webcitation.org/6LQUqMnqL,). neoadjuvant and adjuvant treatment strategies (CRD42012002656); http://www.crd.york.ac.uk/prospero/display_record.asp?ID=CRD42012002656 (Archived by WebCite at http://www.webcitation.org/6LQVvEHuf). liver transplantation (CRD42012002655); http://www.crd.york.ac.uk/prospero/display_record.asp?ID=CRD42012002655 (Archived by WebCite at http://www.webcitation.org/6LQW7WFo3,). resection of the locoregional primary NET (CRD42012002654); http://www.crd.york.ac.uk/prospero/display_record.asp?ID=CRD42012002654 (Archived by WebCite at http://www.webcitation.org/6LQWEIuGe).

Diagnosis and prediction of neuroendocrine liver metastases: a protocol of six systematic reviews

Background

Patients with hepatic metastases from neuroendocrine tumors (NETs) benefit from an early diagnosis, which is crucial for the optimal therapy and management. Diagnostic procedures include morphological and functional imaging, identification of biomarkers, and biopsy.

Objective

The aim of six systematic reviews discussed in this study is to assess the predictive value of Ki67 index and other biomarkers, to compare the diagnostic accuracy of morphological and functional imaging, and to define the role of biopsy in the diagnosis and prediction of neuroendocrine tumor liver metastases.

Methods

An objective group of librarians will provide an electronic search strategy to examine the following databases: MEDLINE, EMBASE and The Cochrane Library (Cochrane Database of Systematic Reviews, Cochrane Central Register of Controlled Trials (CENTRAL), Database of Abstracts of Reviews of Effects). There will be no restriction concerning language and publication date. The qualitative and quantitative synthesis of the systematic review will be conducted with randomized controlled trials (RCT), prospective and retrospective comparative cohort studies, and case-control studies. Case series will be collected in a separate database and only used for descriptive purposes.

Results

This study is ongoing and presents a protocol of six systematic reviews to elucidate the role of histopathological and biochemical markers, biopsies of the primary tumor and the metastases as well as morphological and functional imaging modalities for the diagnosis and prediction of neuroendocrine liver metastases.

Conclusions

These systematic reviews will assess the value and accuracy of several diagnostic modalities in patients with NET liver metastases, and will provide a basis for the development of clinical practice guidelines.

Trial Registration

The systematic reviews have been prospectively registered with the International Prospective Register of Systematic Reviews (PROSPERO): CRD42012002644; http://www.metaxis.com/prospero/full_doc.asp?RecordID=2644 (Archived by WebCite at http://www.webcitation.org/6LzCLd5sF), CRD42012002647; http://www.metaxis.com/prospero/full_doc.asp?RecordID=2647 (Archived by WebCite at http://www.webcitation.org/6LzCRnZnO), CRD42012002648; http://www.metaxis.com/prospero/full_doc.asp?RecordID=2648 (Archived by WebCite at http://www.webcitation.org/6LzCVeuVR), CRD42012002649; http://www.metaxis.com/prospero/full_doc.asp?RecordID=2649 (Archived by WebCite at http://www.webcitation.org/6LzCZzZWU), CRD42012002650; http://www.metaxis.com/prospero/full_doc.asp?RecordID=2650 (Archived by WebCite at http://www.webcitation.org/6LzDPhGb8), CRD42012002651; http://www.crd.york.ac.uk/PROSPERO/display_record.asp?ID=CRD42012002651#.UrMglPRDuVo (Archived by WebCite at http://www.webcitation.org/6LzClCNff).

Pheochromocytoma crisis

Key Clinical Message

Adrenergic crisis induced by a pheochromocytoma leads to life-threatening catecholamine-induced hemodynamic disturbances. Successful treatment of a pheochromocytoma crisis demands prompt diagnosis, vigorous pharmacological therapy and emergent tumor removal, if the patient continues to deteriorate

Liver failure after extended hepatectomy in mice is mediated by a p21-dependent barrier to liver regeneration

BACKGROUND & AIMS

Extended liver resection leads to hepatic failure because of a small remnant liver volume. Excessive parenchymal damage has been proposed as the principal cause of this failure, but little is known about the contribution of a primary deficiency in liver regeneration. We developed a mouse model to assess the regenerative capacity of a critically small liver remnant.

METHODS

Extended (86%) hepatectomy (eHx) was modified to minimize collateral damage; effects were compared with those of standard (68%) partial hepatectomy (pHx) in mice. Markers of liver integrity and survival were evaluated after resection. Liver regeneration was assessed by weight gain, proliferative activity (analyses of Ki67, proliferating cell nuclear antigen, phosphorylated histone 3, mitosis, and ploidy), and regeneration-associated molecules. Knockout mice were used to study the role of p21.

RESULTS

Compared with pHx, survival of mice was reduced after eHx, and associated with cholestasis and impaired liver function. However, no significant differences in hepatocyte death, sinusoidal injury, oxidative stress, or energy depletion were observed between mice after eHx or pHx. No defect in the initiation of hepatocyte proliferation was apparent. However, restoration of liver mass was delayed after eHx and associated with inadequate induction of Foxm1b and a p21-dependent delay in cell-cycle progression. In p21(-/-) mice, the cell cycle was restored, the gain in liver weight was accelerated, and survival improved after eHx.

CONCLUSIONS

Significant parenchymal injury is not required for liver failure to develop after extended hepatectomy. Rather, liver dysfunction after eHx results from a transient, p21-dependent block before hepatocyte division. Therefore, a deficiency in cell-cycle progression causes liver failure after extended hepatectomy and can be overcome by inhibition of p21.

The value of pancreatic stone protein in predicting acute appendicitis in patients presenting at the emergency department with abdominal pain

Background

Pancreatic Stone Protein (PSP) is a protein naturally produced mainly in the pancreas and the gut. There is evidence from experimental and clinical trials that blood PSP levels rise in the presence of inflammation or infection. However, it is not known whether PSP is superior to other established blood tests (e.g. White Blood Count, Neutrophils or C - reactive protein) in predicting appendicitis in patients presenting with abdominal pain and a clinical suspicion of appendicitis at the emergency room.

Methods/design

The PSP Appendix Trial is a prospective, multi-center, cohort study to assess the value of PSP in the diagnostic workup of acute appendicitis. 245 patients will be prospectively recruited. Interim analysis will be performed once 123 patients are recruited. The primary endpoint of the study concerns the diagnostic accuracy of PSP in predicting acute appendicitis and therefore the evidence of appendicitis on the histopathological specimen after appendectomy.

Discussion

The PSP Appendix Trial is a prospective, multi-center, cohort study to assess the value of PSP in the diagnostic workup of acute appendicitis.

Trial registration

ClinicalTrials.gov: NCT01610193; Institution Ethical Board Approval ID: KEKZH- Nr. 2011–0501