Physical activity decreases in patients on the liver transplant waiting list and influences postoperative outcome-a prospective cohort study

Background

Physical deconditioning affects patients suffering from end-stage liver disease (ESLD). Liver transplantation (LT) is the only curative option for ESLD. Growing evidence suggests that pre-habilitation is beneficial in reducing post-surgical morbidity and mortality. We investigated physical activity (PA) in patients awaiting LT in a country with long waiting times.

Methods

Prospective, single center, longitudinal study in Bern, Switzerland between June 2019 and February 2020 (halted due to SARS-CoV-2 pandemic), with follow-up data up to six months post-transplant. Patients were instructed to use a wrist tracker (FitBit) to monitor PA, which was assessed using mixed-effects generalized linear models. The study was approved by the local ethics committee (BASEC ID 2019-00606).

Results

Thirty-five patients were included [71% male, median 59 years, body mass index (BMI) 28 kg/m2, lab Model End-Stage Liver Disease (MELD) 11], 17 (49%) pre-frail and 5 (14%) frail according to the Liver Frailty Index (LFI). Twenty-eight patients underwent transplantation with 0 ninety-day mortality and 15 (53.6%) composite adverse clinical outcome. Median daily steps were 4,661 [interquartile range (IQR), 1,685-8,609] and weekly moderate PA (MPA) was 41 min (IQR, 0-127 min). Longitudinal analysis showed that female patients and patients on nutritional support had an increase in MPA between weeks 20 and 40. A significant decrease was seen in MPA after week 40, whilst no significant association was seen with age, Child-Pugh Score, LFI or quality of life at time of inclusion. MPA was significantly associated with the occurrence of the composite clinical endpoint after week 30 of waiting time (odds ratio 0.882, P=0.026). World Health Organization (WHO)-recommended MPA was significantly associated with less adverse composite clinical outcomes (P<0.001).

Conclusions

In patients listed for LT, MPA decreased over time, showing a significant association with adverse outcome, specifically after week 30 on the waiting list. Our data support the implementation of routine pre-habilitation in patients awaiting LT.

Feasibility and safety of intraoperative bile duct clearance by antegrade transcystic balloon sphincteroplasty: A prospective observational pilot study

BACKGROUND

Concomitant cholecystolithiasis and choledocholithiasis are common. Standard treatments are endoscopic retrograde cholangiography (ERC) followed by cholecystectomy or laparoendoscopic rendezvous. Endoscopic retrograde cholangiography has drawbacks, such as post-ERC pancreatitis or bleeding, and potentially more than one intervention is required to address common bile duct (CBD) stones. Safety and feasibility of an intraoperative antegrade transcystic single-stage approach during cholecystectomy with balloon sphincteroplasty and pushing of stones to the duodenum has not been evaluated prospectively. The aim of this pilot study was to evaluate this procedure regarding safety, feasibility, and stone clearance rate.

METHODS

Prospective single-center intervention study (SUPER Reporting-Guideline). Main inclusion criterion was confirmed choledocholithiasis (stones ≤6 mm) at intraoperative cholangiography. Success of the procedure was defined as CBD stone clearance at intraoperative control cholangiography, absence of symptoms and no elevated cholestasis parameters at 6 weeks follow-up. Simon's two-stage design was used to determine sample size.

RESULTS

From January 2021 to April 2022, a total of 57 patients fulfilled the final inclusion criteria and were included. Mild pancreatitis or cholangitis were present upon admission in 15 (26%) and 15 (26%) patients, respectively. Median number of CBD-stones was 1 (1-6). Median stone diameter was 4 mm (0.1-6 mm). Common bile duct stone clearance was achieved in 54 patients (94%). The main reason for failed CBD clearance was the inability to push the guidewire along the biliary stone into the duodenum. Median intervention time was 28 minutes (14-129 minutes). While there was no postoperative pancreatitis, two patients (3.5%) had asymptomatic hyperlipasemia 4 hours postoperatively.

CONCLUSION

Intraoperative CBD stone clearance by antegrade balloon sphincteroplasty appears to be safe and highly feasible. Its overall superiority to the current standards warrants evaluation by a randomized controlled trial.

LEVEL OF EVIDENCE

Therapeutic/Care Management, Level V.

The trajectory of anti-recEm18 antibody levels determines follow-up after curative resection of hepatic alveolar echinococcosis

INTRODUCTION

Recurrence after curative resection of hepatic alveolar echinococcosis remains a clinical challenge. The current study tested if assessment of anti-recEm18 allows for postsurgical patient surveillance.

METHODS

A retrospective study with patients undergoing liver resection for alveolar echinococcosis (n = 88) at the University Hospital Bern from 2002 to 2020 and at the University Hospital and Medical Center Ulm from 2011 to 2017 was performed. Analysis was directed to determine a potential association of pre- and postoperative values of anti-recEm18 with clinical outcomes.

RESULTS

Anti-recEm18 had a linear correlation to the maximum lesion diameter (R2 = 0.558). Three trajectories of anti-recEm18 were identified based on a threshold of 10 AU/ml: "Em18-low" (n = 31), "responders" (n = 53) and "residual disease" (n = 4). The decline of anti-recEm18 in "responders" reached a plateau after 10.9 months at which levels decreased by 90%. The only patient with recurrence in the entire population was also the only patient with a secondary increase of anti-recEm18.

CONCLUSION

In patients with preoperative elevated values, anti-recEm18 confirms curative surgery at 12 months follow-up and allows for long-term surveillance.

Intestinal dysbiosis as an intraoperative predictor of septic complications: evidence from human surgical cohorts and preclinical models of peritoneal sepsis

Major surgery exposes the intestinal microbiota to inflammatory and antibiotic stressors, which alter the microbiota composition of the intestinal lumen and fecal contents. However, it is not sufficiently understood, if such dysbiosis develops already during surgery and if alterations in microbiota may be the cause of surgical complications. End-of-surgery composition of the microbiota in the rectum was assessed in 41 patients undergoing either rectal or duodenopancreatic resection and was compared to baseline before surgery using 16S-rRNA sequencing. A subset of patients developed severe dysbiosis at the end of surgery, which was characterized by an overgrowth of the Proteobacteria phylum that includes the facultative pathogen E. coli. To test if dysbiosis impacts on surgical outcomes, dysbiosis was modeled in mice by a single oral administration of vancomycin prior to cecal ligation and puncture. Dysbiosis was associated with impaired post-surgical survival, dysregulation of the host's immune response, elevated bacterial virulence and reduced bacterial metabolism of carbon sources. In conclusion, dysbiosis can be detected already at the end of surgery in a fraction of patients undergoing major surgery. Modelling surgery-associated dysbiosis in mice using single-shot administration of vancomycin induced dysbiosis and resulted in elevated mortality.

Comparison of transarterial bland embolization and drug-eluting beads transarterial chemoembolization for very early and early hepatocellular carcinoma not amenable for surgery or ablation: a single center retrospective data analysis

Background

Transarterial chemoembolization (TACE) is the accepted therapy for intermediate hepatocellular carcinoma (HCC). Although recent data suggests that bland transarterial embolization (TAE) is equally effective in intermediate HCC, not much is known about the efficacy in very early and early HCC not amenable for ablation or resection. We aimed to compare the outcome of patients with very early and early HCC treated by drug-eluting beads TACE (DEB-TACE), a specific technique of TACE using DC beads, and TAE using microparticles with a size of 100 µm up to 700 µm.

Methods

Clinical data of totally 95 patients with very early and early HCC not amenable for surgery or ablation, treated between 2009 and 2019 at the Department of Visceral Surgery and Medicine and the Interdisciplinary Center of Vascular Interventions, University Hospital Bern, Switzerland, were retrospectively analyzed (52 patients in DEB-TACE and 42 patients in TAE group, respectively). All images were assessed using the modified Response Evaluation Criteria in Solid Tumors (mRECIST). Primary endpoint was overall survival (OS). Secondary endpoints were local response rate and time to local progression.

Results

Most patients presented with Child-Pugh A. Thrombocytes were significantly lower in patients treated by TAE. Minor side effects occurred equally in both groups. No differences were detected in terms of OS, local tumor recurrence and response rate.

Conclusions

Compared with DEB-TACE, TAE is an equally effective and save therapy for very early and early HCC not amenable for resection or ablation without differences in local tumor control and OS.

Müller matrix polarimetry for pancreatic tissue characterization

Polarimetry is an optical characterization technique capable of analyzing the polarization state of light reflected by materials and biological samples. In this study, we investigate the potential of Müller matrix polarimetry (MMP) to analyze fresh pancreatic tissue samples. Due to its highly heterogeneous appearance, pancreatic tissue type differentiation is a complex task. Furthermore, its challenging location in the body makes creating direct imaging difficult. However, accurate and reliable methods for diagnosing pancreatic diseases are critical for improving patient outcomes. To this end, we measured the Müller matrices of ex-vivo unfixed human pancreatic tissue and leverage the feature-learning capabilities of a machine-learning model to derive an optimized data representation that minimizes normal-abnormal classification error. We show experimentally that our approach accurately differentiates between normal and abnormal pancreatic tissue. This is, to our knowledge, the first study to use ex-vivo unfixed human pancreatic tissue combined with feature-learning from raw Müller matrix readings for this purpose.

Predictors for surgical site infection in patients undergoing therapeutic or prophylactic intra-abdominal onlay mesh (IPOM) implantation in clean and contaminated surgical fields

BACKGROUND

Prophylactic intra-abdominal onlay mesh (IPOM) implantation has been shown to reduce the rate of fascial dehiscence and incisional hernia. However, surgical site infection (SSI) in presence of an IPOM remains a concern. The aim of this study was to assess predictors for SSI following IPOM placement in hernia and non-hernia abdominal surgery in clean and contaminated surgical fields.

METHODS

Observational study including patients undergoing IPOM placement at a Swiss tertiary care hospital 2007-2016. IPOM implantation was performed in hernia and non-hernia elective and emergency abdominal surgery, including contaminated and infected surgical fields. The incidence of SSI was prospectively assessed by Swissnoso according to CDC criteria. The effect of disease- and procedure-related factors on SSI was assessed in multivariable regression analysis, adjusting for patient-related factors.

RESULTS

A total of 1072 IPOM implantations were performed. Laparoscopy was performed in 415 patients (38.7%), laparotomy in 657 patients (61.3%). SSI occurred in 172 patients (16.0%). Superficial, deep, and organ space SSI were found in 77 (7.2%), 26 (2.4%), and 69 (6.4%) patients, respectively. Multivariable analysis revealed emergency hospitalization (OR 1.787, p = 0.006), previous laparotomy (1.745, p = 0.029), duration of operation (OR 1.193, p < 0.001), laparotomy (OR 6.167, p < 0.001), bariatric (OR 4.641, p < 0.001), colorectal (OR 1.941, p = 0.001), and emergency (OR 2.510, p < 0.001) surgery, wound class ≥ 3 (OR 3.878, p < 0.001), and non-polypropylene mesh (OR 1.818, p = 0.003) as independent predictors for SSI. Hernia surgery was independently associated with a lower risk for SSI (OR 0.165, p < 0.001).

CONCLUSION

This study revealed emergency hospitalization, previous laparotomy, duration of operation, laparotomy, as well as bariatric, colorectal, and emergency surgery, abdominal contamination or infection, and usage of non-polypropylene mesh as independent predictors for SSI. In contrast, hernia surgery was associated with a lower risk for SSI. The knowledge of these predictors will help to balance benefits of IPOM implantation against the risk for SSI.

A prospective multicentre trial on survival after Microwave Ablation VErsus Resection for Resectable Colorectal liver metastases (MAVERRIC)

AIM

This multi-centre prospective cohort study aimed to investigate non-inferiority in patients' overall survival when treating potentially resectable colorectal cancer liver metastasis (CRLM) with stereotactic microwave ablation (SMWA) as opposed to hepatic resection (HR).

METHODS

Patients with no more than 5 CRLM no larger than 30 mm, deemed eligible for both SMWA and hepatic resection at the local multidisciplinary team meetings, were deliberately treated with SMWA (study group). The contemporary control group consisted of patients with no more than 5 CRLM, none larger than 30 mm, treated with HR, extracted from a prospectively maintained nationwide Swedish database. After propensity-score matching, 3-year overall survival (OS) was compared as the primary outcome using Kaplan-Meier and Cox regression analyses.

RESULTS

All patients in the study group (n = 98) were matched to 158 patients from the control group (mean standardised difference in baseline covariates = 0.077). OS rates at 3 years were 78% (Confidence interval [CI] 68-85%) after SMWA versus 76% (CI 69-82%) after HR (stratified Log-rank test p = 0.861). Estimated 5-year OS rates were 56% (CI 45-66%) versus 58% (CI 50-66%). The adjusted hazard ratio for treatment type was 1.020 (CI 0.689-1.510). Overall and major complications were lower after SMWA (percentage decrease 67% and 80%, p < 0.01). Hepatic retreatments were more frequent after SMWA (percentage increase 78%, p < 0.01).

CONCLUSION

SMWA is a valid curative-intent treatment alternative to surgical resection for small resectable CRLM. It represents an attractive option in terms of treatment-related morbidity with potentially wider options regarding hepatic retreatments over the future course of disease.

Gastroesophageal Junction and Pylorus Distensibility Before and After Sleeve Gastrectomy-pilot Study with EndoFlipTM

Sleeve gastrectomy (SG) is the most frequently performed bariatric surgical intervention worldwide. Gastroesophageal reflux disease (GERD) is frequently observed after SG and is a relevant clinical problem. This prospective study investigated the gastroesophageal junction (GEJ) and pyloric sphincter by impedance planimetry (EndoFlipTM) and their association with GERD at a tertiary university hospital center. Between January and December 2018, patients undergoing routine laparoscopic SG had pre-, intra-, and postoperative assessments of the GEJ and pyloric sphincter by EndoFlipTM. The distensibility index (DI) was measured at different volumes and correlated with GERD (in accordance with the Lyon consensus guidelines). Nine patients were included (median age 48 years, preoperative BMI 45.1 kg/m2, 55.6% female). GERD (de novo or stable) was observed in 44.4% of patients one year postoperatively. At a 40-ml filling volume, DI increased significantly pre- vs. post-SG of the GEJ (1.4 mm2/mmHg [IQR 1.1-2.6] vs. 2.9 mm2/mmHg [2.6-5.3], p VALUE=0.046) and of the pylorus (6.0 mm2/mmHg [4.1-10.7] vs. 13.1 mm2/mmHg [7.6-19.2], p VALUE=0.046). Patients with postoperative de novo or stable GERD had a significantly increased preoperative DI at 40 ml of the GEJ (2.6 mm2/mmHg [1.9-3.5] vs. 0.5 mm2/mmHg [0.5-1.1], p VALUE=0.031). There was no significant difference in DI at 40 mL filling in the preoperative pylorus and postoperative GEJ or pylorus. In this prospective study, the DI of the GEJ and the pylorus significantly increased after SG. Postoperative GERD was associated with a significantly higher preoperative DI of the GEJ but not of the pylorus.

No signs of check-list fatigue - introducing the StOP? intra-operative briefing enhances the quality of an established pre-operative briefing in a pre-post intervention study

Background

The team timeout (TTO) is a safety checklist to be performed by the surgical team prior to incision. Exchange of critical information is, however, important not only before but also during an operation and members of surgical teams frequently feel insufficiently informed by the operating surgeon about the ongoing procedure. To improve the exchange of critical information during surgery, the StOP?-protocol was developed: At appropriate moments during the procedure, the leading surgeon briefly interrupts the operation and informs the team about the current Status (St) and next steps/objectives (O) of the operation, as well as possible Problems (P), and encourages questions of other team members (?). The StOP?-protocol draws attention to the team. Anticipating the occurrence of StOP?-protocols may support awareness of team processes and quality issues from the beginning and thus support other interventions such as the TTO; however, it also may signal an additional demand and contribute to a phenomenon akin to "checklist fatigue." We investigated if, and how, the introduction of the StOP?-protocol influenced TTO quality.

Methods

This was a prospective intervention study employing a pre-post design. In the visceral surgical departments of two university hospitals and one urban hospital the quality of 356 timeouts (out of 371 included operation) was assessed by external observers before (154) and after (202) the introduction of the StOP?-briefing. Timeout quality was rated in terms of timeout completeness (number of checklist items mentioned) and timeout quality (engagement, pace, social atmosphere, noise).

Results

As compared to the baseline, after the implementation of the StOP?-protocol, observed timeouts had higher completeness ratings (F = 8.69, p = 0.003) and were rated by observers as higher in engagement (F = 13.48, p < 0.001), less rushed (F = 14.85, p < 0.001), in a better social atmosphere (F = 5.83, p < 0.016) and less noisy (F = 5.35, p < 0.022).

Conclusion

Aspects of TTO are affected by the anticipation of StOP?-protocols. However, rather than harming the timeout goals by inducing "checklist fatigue," it increases completeness and quality of the team timeout.

Learning how to robustly estimate camera pose in endoscopic videos

PURPOSE

Surgical scene understanding plays a critical role in the technology stack of tomorrow's intervention-assisting systems in endoscopic surgeries. For this, tracking the endoscope pose is a key component, but remains challenging due to illumination conditions, deforming tissues and the breathing motion of organs.

METHOD

We propose a solution for stereo endoscopes that estimates depth and optical flow to minimize two geometric losses for camera pose estimation. Most importantly, we introduce two learned adaptive per-pixel weight mappings that balance contributions according to the input image content. To do so, we train a Deep Declarative Network to take advantage of the expressiveness of deep learning and the robustness of a novel geometric-based optimization approach. We validate our approach on the publicly available SCARED dataset and introduce a new in vivo dataset, StereoMIS, which includes a wider spectrum of typically observed surgical settings.

RESULTS

Our method outperforms state-of-the-art methods on average and more importantly, in difficult scenarios where tissue deformations and breathing motion are visible. We observed that our proposed weight mappings attenuate the contribution of pixels on ambiguous regions of the images, such as deforming tissues.

CONCLUSION

We demonstrate the effectiveness of our solution to robustly estimate the camera pose in challenging endoscopic surgical scenes. Our contributions can be used to improve related tasks like simultaneous localization and mapping (SLAM) or 3D reconstruction, therefore advancing surgical scene understanding in minimally invasive surgery.

Efficacy and Safety of Rivaroxaban for Postoperative Thromboprophylaxis in Patients After Bariatric Surgery: A Randomized Clinical Trial

Importance

Venous thromboembolism (VTE) is a leading cause of morbidity and mortality after bariatric surgery. Clinical end point studies on thromboprophylaxis with direct oral anticoagulants in patients undergoing bariatric surgery are lacking.

Objective

To assess the efficacy and safety of a prophylactic dose of 10 mg/d of rivaroxaban for both 7 and 28 days after bariatric surgery.

Design, Setting, and Participants

This assessor-blinded, phase 2, multicenter randomized clinical trial was conducted from July 1, 2018, through June 30, 2021, with participants from 3 academic and nonacademic hospitals in Switzerland.

Intervention

Patients were randomized 1 day after bariatric surgery to 10 mg of oral rivaroxaban for either 7 days (short prophylaxis) or 28 days (long prophylaxis).

Main Outcomes and Measures

The primary efficacy outcome was the composite of deep vein thrombosis (symptomatic or asymptomatic) and pulmonary embolism within 28 days after bariatric surgery. Main safety outcomes included major bleeding, clinically relevant nonmajor bleeding, and mortality.

Results

Of 300 patients, 272 (mean [SD] age, 40.0 [12.1] years; 216 women [80.3%]; mean body mass index, 42.2) were randomized; 134 received a 7-day and 135 a 28-day VTE prophylaxis course with rivaroxaban. Only 1 thromboembolic event (0.4%) occurred (asymptomatic thrombosis in a patient undergoing sleeve gastrectomy with extended prophylaxis). Major or clinically relevant nonmajor bleeding events were observed in 5 patients (1.9%): 2 in the short prophylaxis group and 3 in the long prophylaxis group. Clinically nonsignificant bleeding events were observed in 10 patients (3.7%): 3 in the short prophylaxis arm and 7 in the long prophylaxis arm.

Conclusions and Relevance

In this randomized clinical trial, once-daily VTE prophylaxis with 10 mg of rivaroxaban was effective and safe in the early postoperative phase after bariatric surgery in both the short and long prophylaxis groups.

Trial Registration

ClinicalTrials.gov Identifier: NCT03522259.

ILC3s restrict the dissemination of intestinal bacteria to safeguard liver regeneration after surgery

It is generally believed that environmental or cutaneous bacteria are the main origin of surgical infections. Therefore, measures to prevent postoperative infections focus on optimizing hygiene and improving asepsis and antisepsis. In a large cohort of patients with infections following major surgery, we identified that the causative bacteria are mainly of intestinal origin. Postoperative infections of intestinal origin were also found in mice undergoing partial hepatectomy. CCR6⁺ group 3 innate lymphoid cells (ILC3s) limited systemic bacterial spread. Such bulwark function against host invasion required the production of interleukin-22 (IL-22), which controlled the expression of antimicrobial peptides in hepatocytes, thereby limiting bacterial spread. Using genetic loss-of-function experiments and punctual depletion of ILCs, we demonstrate that the failure to restrict intestinal commensals by ILC3s results in impaired liver regeneration. Our data emphasize the importance of endogenous intestinal bacteria as a source for postoperative infection and indicate ILC3s as potential new targets.

The impact of perceived donor liver quality on post-transplant outcome

BACKGROUND

We analysed the impact of perceived liver donor quality on transplant recipient outcomes.

METHODS

this prospective cohort study included all deceased liver donors during 2008-2018 in the Swiss Transplant Cohort Study. Perceived low-quality liver donors were defined when refused for ≥5 top listed recipients or for all recipients in at least one centre before being transplanted. The effect of liver donor quality on relisting or recipient death at 1 week and 1 year after transplantation was analysed using Kaplan-Meier and Cox proportional hazard models. A 1:3 matching was also performed using a recipient score.

RESULTS

Of 973 liver donors, 187 (19.2%) had perceived poor-quality. Males, obesity, donation after circulatory death and alanine aminotransferase values were significantly associated with perceived poor-quality, with no significant effect of the perceived quality on re-listing or death within the first week and first year post-transplant [(aHR) = 1.45, 95% CI: (0.6, 3.5), P = 0.41 and aHR = 1.52 (95% CI 0.98-2.35), P = 0.06], adjusting by recipient age and gender, obesity, diabetes, prior liver transplantation and model for end-stage liver disease (MELD) score. At 1 year, prior liver transplantation and higher MELD score associated with higher risk of re-listing or death.

CONCLUSION

Comparable post-transplant outcomes with different perceived quality liver donors stresses the need to improve donor selection in liver transplantation.

Plasticity of the adult human small intestinal stoma microbiota

The human distal small intestine (ileum) has a distinct microbiota, but human studies investigating its composition and function have been limited by the inaccessibility of the ileum without purging and/or deep intubation. We investigated inherent instability, temporal dynamics, and the contribution of fed and fasted states using stoma samples from cured colorectal cancer patients as a non-invasive access route to the otherwise inaccessible small and large intestines. Sequential sampling of the ileum before and after stoma formation indicated that ileostoma microbiotas represented that of the intact small intestine. Ileal and colonic stoma microbiotas were confirmed as distinct, and two types of instability in ileal host-microbial relationships were observed: inter-digestive purging followed by the rapid postprandial blooming of bacterial biomass and sub-strain appearance and disappearance within individual taxa after feeding. In contrast to the relative stability of colonic microbiota, the human small intestinal microbiota biomass and its sub-strain composition can be highly dynamic.

Risk factors for chronic postsurgical pain in visceral surgery: a matched case–control analysis

Purpose

Chronic postsurgical pain (CPSP) after abdominal visceral surgery is an underestimated long-term complication with relevant impact on health-related quality of life and socioeconomic costs. Early identification of affected patients is important. We aim to identify the incidence and risk factors for CPSP in this patient population.

Methods

Retrospective case–control matched analysis including all patients diagnosed with CPSP after visceral surgery in our institution between 2016 and 2019. One-to-two case–control matching was based on operation category (HPB, upper-GI, colorectal, transplantation, bariatric, hernia and others) and date of surgery. Potential risk factors for CPSP were identified using conditional multivariate logistic regression.

Results

Among a cohort of 3730 patients, 176 (4.7%) were diagnosed with CPSP during the study period and matched to a sample of 352 control patients. Independent risk factors for CPSP were age under 55 years (OR 2.64, CI 1.51–4.61), preexisting chronic pain of any origin (OR 3.42, CI 1.75–6.67), previous abdominal surgery (OR 1.99, CI 1.11–3.57), acute postoperative pain (OR 1.29, CI 1.16–1.44), postoperative use of non-steroidal anti-inflammatory drugs (OR 3.73, OR 1.61–8.65), opioid use on discharge (OR 3.78, CI 2.10–6.80) and length of stay over 3 days (OR 2.60, CI 1.22–5.53). Preoperative Pregabalin intake was protective (OR 0.02, CI 0.002–0.21).

Conclusion

The incidence of CPSP is high and associated with specific risk factors, some of them modifiable. Special attention should be given to sufficient treatment of preexisting chronic pain and acute postoperative pain.

Performance of quick sequential organ failure assessment and modified age disease adjusted qadSOFA for the prediction of outcomes in emergency general surgery patients

BACKGROUND

Sepsis is a highly prevalent condition and is associated with a reported in-hospital mortality rate up to 40% in patients with abdominal sepsis requiring emergency general surgery (EGS). The quick sequential organ failure assessment score (qSOFA) has not been studied for EGS patients.

METHODS

Retrospective cohort study in adult patients undergoing abdominal EGS at a university tertiary care center from 2016 to 2018. The primary outcome was mortality. The effect of clinical variables on outcomes was assessed in univariable and multivariable logistic regression analyses. Based on these results, the qSOFA score was modified. The performance of scores was assessed using receiver operating characteristics.

RESULTS

Five hundred seventy-eight patients undergoing abdominal EGS were included. In-hospital mortality was 4.8% (28/578). Independent predictors for mortality were mesenteric ischemia (odds ratio [OR] 15.9; 95% confidence interval [CI] 5.2-48.6; p < 0.001), gastrointestinal tract perforation (OR 4.9; 95% CI 1.7-14.0; p = 0.003), 65 years or older (OR 4.1; 95% CI 1.5-11.4; p = 0.008), and increasing qSOFA (OR 1.8; 95% CI 1.2-2.8; p = 0.007). The modified qSOFA (qadSOFA) was developed. The area under the receiver operating characteristic curve of the qSOFA and qadSOFA for mortality was 0.715 and 0.859, respectively. Optimal cutoff value was identified as qadSOFA ≥ 3 (Youden Index 64.1%).

CONCLUSION

This is the first study investigating the qSOFA as a predictor for clinical outcomes in EGS. Compared with the qSOFA, the new qadSOFA revealed an excellent predictive power for clinical outcomes. Further validation of qadSOFA is warranted.

LEVEL OF EVIDENCE

Diagnostic test/criteria; Level II.

Laparoscopic resection of hepatic alveolar echinococcosis: A single-center experience

Introduction

Alveolar echinococcosis (AE) remains a very rare disease requiring complete radical resection for curative treatment. While open approaches are common, safety and efficacy of laparoscopic resections remain unknown.

Methods

This is a single-center, retrospective cohort study with patients undergoing liver resection for hepatic AE at the Department of Visceral Surgery and Medicine, Bern University Hospital from December 2002 to December 2020. Postoperative outcomes of patients following laparoscopic hepatectomy (LH) for hepatic AE were compared with those of patients undergoing open hepatectomy (OH).

Results

A total of 93 patients underwent liver resection for hepatic AE. Laparoscopic hepatectomy was performed in 23 patients and open hepatectomy in 70 patients. While there were no significant differences in terms of gender, age and diagnostic tools, the majority of patients of the LH cohort were PNM stage 1 (78%) in contrast to only 39% in the OH cohort (p = 0.002). Patients undergoing laparoscopic hepatectomy were treated by minor liver resections in 91% and in 9% by major liver resections in comparison to the open hepatectomy cohort with 61% major liver resections and 39% minor resections. Laparoscopic hepatectomy was associated with shorter mean operation time (127 minutes vs. 242 minutes, p <0.001), lower major complication rate (0% vs. 11%, p = 0.322) and shorter mean length of hospital stay (4 days vs. 13 days, p <0.001). Patients with LH had a distinct, but not significant lower recurrence rate (0% vs. 4%, p = 0.210) during a mean follow-up of 55 months compared with a follow-up of 76 months in the OH cohort. After subgroup analysis of PNM stage 1 patients, similar results are seen with persistent shorter mean operation time (120 minutes vs. 223 minutes, p <0.001), lower major complication rate (0% vs. 8%, p = 0.759) and shorter length of hospital stay (4 days vs. 12 days, p <0.001).

Conclusion

Laparoscopy appears as a feasible and safe approach for patients with PNM stage 1 alveolar echinococcosis without impact on early disease recurrence.

In this retrospective cohort study laparoscopic hepatectomy for hepatic alveolar echinococcosis had no negative impact on perioperative outcomes, disease recurrence or survival compared with open hepatectomy. The importance of this finding is that the laparoscopic approach is feasible and safe for selected patients with hepatic alveolar echinococcosis, especially those with PNM stage 1.

Empyema after image-guided percutaneous intercostal drainage of subdiaphragmatic collection: a case series

Background

Treatment of subdiaphragmatic collection by intercostal image-guided drain placement is associated with a risk of pleural complications including potentially life-threatening pleural empyema. Descriptions of patient characteristics and clinical course of postinterventional pleural empyema are lacking. We aim to present characteristics, clinical course and outcomes of patients with empyema after intercostal approach of drain placement.

Methods

Data was collected as a retrospective single center case series and included adult patients with decortication for treatment of pleural empyema after image-guided percutaneous intercostal drainage of a subdiaphragmatic collection between 01.01.2009 and 31.01.2021.

Results

We identified ten patients, nine male and one female, all suffering from subdiaphragmatic collection treated with intercostal drain. All patients developed pleural empyema after drain placement and received surgical decortication. Similarities between patients were drain placement under computed tomography (CT)-guidance (eight of ten patients), lateral position of the drain (seven of ten patients), drain insertion in the eighth intercostal space (ICS) (six of ten patients) and existing comorbidities as malnutrition (six of ten patients), diabetes (four of ten patients) and cancer (three of ten patients). The majority of patients had a prolonged length of hospital stay (LOS) with an average duration of 40 days. Nearly half of the patients needed intensive care unit (ICU) treatment and one patient died postoperatively from respiratory exhaustion.

Conclusions

In this series, empyema after intercostal drainage was associated with prolonged LOS and was potentially life-threatening. The most commonly shared features in our cohort were the high prevalence of comorbidities, drain insertion above ninth ICS as well as lateral position of the drain. These factors should be addressed in prospective studies to evaluate potential correlation with postinterventional empyema. For optimal management of patients with subdiaphragmatic collection treated by intercostal drainage, awareness of potential associated complications is crucial.

Combination of Sterile Injury and Microbial Contamination to Model Post-surgical Peritoneal Adhesions in Mice

Abdominal surgeries are frequently associated with the development of post-surgical adhesions. These are irreversible fibrotic scar bands that appear between abdominal organs and the abdominal wall. Patients suffering from adhesions are at risk of severe complications, such as small bowel obstruction, chronic pelvic pain, or infertility. To date, no cure exists, and the understanding of underlying molecular mechanisms of adhesion formation is incomplete. The current paradigm largely relies on sterile injury mouse models. However, abdominal surgeries in human patients are rarely completely sterile procedures. Here, we describe a modular surgical procedure for simultaneous or separate induction of sterile injury and microbial contamination. Combined, these insults synergistically lead to adhesion formation in the mouse peritoneal cavity. Surgical trauma is confined to a localized sterile injury of the peritoneum. Microbial contamination of the peritoneal cavity is induced by a limited perforation of the microbe-rich large intestine or by injection of fecal content. The presented protocol extends previous injury-based adhesion models by an additional insult through microbial contamination, which may more adequately model the clinical context of abdominal surgery. Graphical abstract.

Risk factors for chronic postsurgical pain in visceral surgery: A matched case-control analysis

Objective

Chronic postsurgical pain (CPSP) is defined as new and persisting pain three months after a surgical procedure, whereby other causes of pain have been excluded. Although CPSP following orthopedic or gynecological surgery has been well investigated, we are lacking data for patients undergoing abdominal visceral surgery. We aim to identify the risk factors for CPSP in this patient population.

Methods

We performed a retrospective case-control matched analysis including all patients diagnosed with CPSP after abdominal visceral surgery between 2016 and 2019, matched to a control group of patients who did not develop CPSP. Excluded were patients for whom no follow-up was available 3 months or more after surgery. Two-to-one case-control matching was based on operation category (hepato-pancreatico-biliary, upper gastrointestinal, colorectal, transplantation, bariatric and others) and date of surgery. The influence of personal, surgical and pain management factors were explored and multivariate logistic regression analysis was performed.

Results

176 patients were diagnosed with CPSP during the study period. They were matched to a sample of 394 control patients extracted from the cohort of 3554 patients without CPSP. The incidence proportion of CPSP was 4.7%. Multivariate logistic regression analysis showed that age under 65 years (OR 2.22, CI 1.34-3.69, p=0.002), preexisting chronic pain of any origin (OR 3.39, CI 2.04-5.62, p=0.000), previous abdominal surgery (OR 1.71, CI 1.07-2.71, p=0.024), acute postoperative pain (2.62, CI 1.55-4.42, p=0.000) and length of stay over three days (OR 2.11, CI 1.26-3.53, p=0.004) were independent risk factors for CPSP. Preoperative Pregabalin intake was protective (OR 0.04, CI 0.01-0.33, p=0.003).

Conclusion

The identification of these risk factors allows for a preventive and personalized health care approach to our at-risk patients, for whom the optimization of postoperative acute pain management and an additional follow-up consultation 3 months after surgery might be indicated to avoid a delay in diagnosing CPSP. A possible explanation for the protective effect of Pregabalin is that in these patients, preexisting chronic pain might be better controlled in the preoperative phase, and they might have additional follow-up in the postoperative phase, be it from a pain specialist or their general practitioner.

Outer membrane vesicles as carriers for bacterial extracellular ATP modulate local and remote inflammation in peritoneal sepsis

Objective

Adenosine triphosphate (ATP) may be released to the extracellular space and activate specific purinergic receptors to modulate inflammatory responses. In addition to eukaryotes, ATP is also released by bacteria. This bacterial extracellular ATP (eATP) subsequently may act as an inter-kingdom signaling molecule between bacteria and its host. How ATP is secreted by bacteria and its consequences in systemic infection such as sepsis remains unclear. This study aims to determine how ATP is secreted by bacteria and to elucidate its interaction with the host immune system in a model of peritoneal sepsis.

Methods

Bacteria from septic patients were isolated from peritoneal washes. Peritoneal sepsis in mice was induced by cecal ligation and puncture. Peritoneal fluid was collected, (an)aerobically plated and colonies were identified by 16S-sequencing. EATP was periodically measured from bacteria culture supernatant using a luciferin-luciferase assay. Bacteria in culture were counted by plating and the amount of live/dead bacteria was assessed using flow cytometry. To specifically assess the role of bacterial eATP in vivo, E. coli K-12 BW25113 parental strain from the keio collection was used, transformed with a plasmid coding for an apyrase and i.p. injected. Furthermore, a hypervesiculation mutant of this keio collection was used to collect outer membrane vesicles (OMV). These OMV were then loaded with ATP using electroporation and injected i.p in mice.

Results

All bacteria that were isolated from human or mouse peritoneal washes were able to secrete ATP in a growth-phase dependent manner in vitro. In addition to passive release by dying bacteria, we have identified that the amount of eATP is connected with the formation of outer membrane vesicles (OMV) as shown by the E. coliΔtolB hypervesiculation mutant. Whole bacterial eATP led to a significant worse outcome in mice suffering from peritoneal sepsis. In addition, bacterial eATP specifically delivered via OMV worsened septic outcome as well, critically modulating neutrophil recruitment. At the infection site, ATP-loaded OMV led to an impaired recruitment of neutrophils whereas in the lung they led to an elevated infiltration.

Conclusion

OMV serve as a carrier of bacterial wall LPS on its surface as well as bacterial eATP as its content and specifically alter the outcome during sepsis influencing neutrophils locally as well as at remote sites.

Intracellular Proprotein convertase subtilisin/kexin type 9: Recruitment and regulatory role in mitochondrial architecture and bioenergetic

Objective

Circulating Proprotein convertase subtilisin/kexin type 9 (PCSK9) captured the scientific community's attention as powerful target to fight against high serum cholesterol and its associated adverse consequences. Despite the well-described role of PCSK9 in impairing the recycling of low-density lipoprotein receptor (LDLR) on hepatocytes, its intracellular importance in metabolism modulations remain largely unexplored. Here, we describe a novel intracellular function of PCSK9 in hepatocyte metabolism and in liver regeneration.

Methods

A surgical model of partial hepatectomy (PH) was used to induce liver cell proliferation and serological and histological lipo- and glyco-metabolic perturbations were investigated in PCSK9 knockout and wild-type mice before and after PH. Mitochondrial bioenergetic level, compartmental architecture as well as intracellular localization and function of PCSK9 were further analyzed in vitro on murine primary isolated hepatocytes and PCSK9 lentiviral knockdown human liver cancer cell lines.

Results

Loss of PCSK9 expression led to a basal higher mitochondrial bioenergetic status in hepatocytes, characterized by a profound remodeling of mitochondrial architecture. Livers from PCSK9 knockout mice displayed a diffuse oxidative stress and a significant upregulation of cellular detoxification and superoxide radicals removal genes induced by the activation of c-Jun N-terminal kinase (JNK) pathway before PH. PCSK9 deficient mice showed a primed compensatory hepatic hyperplasia after PH, accompanied by an earlier transient regeneration-associated steatosis due to a higher LDLR expression and cholesterol uptake, with an increased β-oxidation, gluconeogenesis and glycolysis rate. Tetramethylrhodamine ethyl ester staining of isolated hepatocytes and liver cancer PCSK9 knockdown clones revealed a significantly reduced mitochondrial membrane potential when compared to controls. Confocal live-cell imaging and proteins immunoprecipitation showed respectively a mitochondrial recruitment of PCSK9 in proliferating cells and its interaction with mitochondrial membrane carriers and chaperons.

Conclusion

Despite the role played by circulating PCSK9 in regulating systemic cholesterol levels, our data shed light on its intracellular impact on mitochondrial architecture, membrane polarization and related metabolic perturbations in compartmental bioenergetics.

Intraperitoneal microbial contamination drives post-surgical peritoneal adhesions by mesothelial EGFR-signaling

Objective

Abdominal surgeries are lifesaving procedures but can be complicated by the formation of peritoneal adhesions, intra-abdominal scars that cause intestinal obstruction, pain, infertility, and significant health costs. Despite this burden, the mechanisms underlying adhesion formation remain unclear and no cure exists. Here, ask how contamination of gut microbes influences post-surgical adhesion formation.

Methods

We make use of an experimental mouse model that allows to investigate how wound repair and adhesion formation differs between sterile injury vs. sterile injury in combination with microbial contamination. We use genetic lineage tracing, bulk- and single-cell RNA-Sequencing to identify potential mechanisms of the observed differences. Next, we use two human cohort studies to confirm the target identified by RNA-Sequencing. Finally, the identified targets are experimentally confirmed by going back to the mouse model.

Results

We show that adhesion myofibroblasts arise from the mesothelium. This transformation is driven by epidermal growth factor receptor (EGFR) signaling. The EGFR ligands amphiregulin and heparin-binding epidermal growth factor, are sufficient to induce these changes. Correspondingly, EGFR inhibition leads to a significant reduction of adhesion formation in mice. Adhesions isolated from human patients are enriched in EGFR positive cells of mesothelial origin and human mesothelium shows an increase of mesothelial EGFR expression during bacterial peritonitis.

Conclusion

Bacterial contamination drives adhesion formation through mesothelial EGFR signaling. This mechanism may represent a therapeutic target for the prevention of adhesions after intra-abdominal surgery.

Impact of gender on surgical site infections in abdominal surgery: A multi-center study

Objective

Male sex is controversially discussed as a risk factor for surgical site infections (SSI). The aim of the present study was to evaluate the impact of gender on SSI in abdominal surgery under elimination of relevant confounders.

Methods

Clinicopathological data of 6603 patients undergoing abdominal surgery from a multi-center prospective database of four Swiss hospitals including patients between 2015 and 2018 were assessed. Patients were stratified according to postoperative SSI and risk factors for SSI were assessed using univariate and multivariate analysis.

Results

In 649 of 6603 patients SSI was reported (9.8%). SSI was significantly associated with increased risk of reoperation (22.7% vs. 3.4%, p &lt;0.001), higher mortality rate (4.6% vs. 0.9%, p &lt;0.001) and higher rate of length of hospital stay &gt; 75th percentile (57.0% vs. 17.9%, p &lt;0.001). In univariate analysis male sex was a significant risk factor for SSI (p = 0.01). In multivariate analysis including multiple confounders’ such as comorbidities and perioperative factors there was no association between male sex and risk of SSI (OR 1.1 [CI 0.8–1.4]). BMI &gt;= 30 kg/m2 (OR 1.8 [CI 1.3–2.3]), duration of surgery &gt; 75th percentile (OR 2.3 [1.8–2.9]), high contamination level (OR 1.3 [1.0–1.6]), laparotomy (OR 1.3 [1.0–1.7]), previous laparotomy (OR 1.4 [1.1–1.7]), blood transfusion (OR 1.7 [1.2–2.4]), cancer (OR 1.3 [1.0–1.8]), malnutrition (OR 2.5 [1.8–3.4]) were independent risk factors for SSI in multivariate analysis.

Conclusion

Under elimination of relevant confounders there is no significant correlation between gender and risk of SSI after abdominal surgery. Independent risk factors for SSI as BMI &gt;= 30 kg/m2, duration of surgery &gt; 75th percentile, high contamination level, surgical approach or malnutrition should be considered during treatment.

The Role of Surgical Expertise and Surgical Access in Retroperitoneal Sarcoma Resection – A Retrospective Study

Background

Retroperitoneal sarcoma (RPS) is a rare disease often requiring multi-visceral and wide margin resections for which a resection in a sarcoma center is advised. Midline incision seems to be the access of choice. However, up to now there is no evidence for the best surgical access. This study aimed to analyze the oncological outcome according to the surgical expertise and also the incision used for the resection.

Methods

All patients treated for RPS between 2007 and 2018 at the Department of Visceral Surgery and Medicine of the University Hospital Bern and receiving a RPS resection in curative intent were included. Patient- and treatment specific factors as well as local recurrence-free, disease-free and overall survival were analyzed in correlation to the hospital type where the resection occurred.

Results

Thirty-five patients were treated for RPS at our center. The majority received their primary RPS resection at a sarcoma center (SC = 23) the rest of the resection were performed in a non-sarcoma center (non-SC = 12). Median tumor size was 24 cm. Resections were performed via a midline laparotomy (ML = 31) or flank incision (FI = 4). All patients with a primary FI (n = 4) were operated in a non-SC (p = 0.003). No patient operated at a non-SC received a multivisceral resection (p = 0.004). Incomplete resection (R2) was observed more often when resection was done in a non-SC (p = 0.013). Resection at a non-SC was significantly associated with worse recurrence-free survival and disease-free survival after R0/1 resection (2 vs 17 months; Log Rank p-value = 0.02 respectively 2 vs 15 months; Log Rank p-value &lt; 0.001).

Conclusions

Resection at a non-SC is associated with more incomplete resection and worse outcome in RPS surgery. Inadequate access, such as FI, may prevent complete resection and multivisceral resection if indicated and demonstrates the importance of surgical expertise in the outcome of RPS resection.

LIM protein Ajuba promotes liver cell proliferation through its involvement in DNA replication and DNA damage control

The LIM-domain protein Ajuba is associated with cell proliferation, a fundamental process of tissue regeneration and cancer. We report that in the liver, Ajuba expression is increased during regeneration and in tumor cells and tissues. Knockout of Ajuba using CRISPR/Cas9 is embryonic lethal in mice. shRNA targeting of Ajuba reduces cell proliferation, delays cell entry into S-phase, reduces cell survival and tumor growth in vivo, and increases expression of the DNA damage marker γH2AX. Ajuba binding partners include proteins involved in DNA replication and damage, such as SKP2, MCM2, MCM7 and RPA70. Taken together, our data support that Ajuba promotes liver cell proliferation associated with development, regeneration, and tumor growth and is involved in DNA replication and damage repair.

Effects of structured intraoperative briefings on patient outcomes: multicentre before-and-after study

BACKGROUND

Operations require collaboration between surgeons, anaesthetia professionals, and nurses. The aim of this study was to determine whether intraoperative briefings influence patient outcomes.

METHODS

In a before-and-after controlled trial (9 months baseline; 9 months intervention), intraoperative briefings were introduced in four general surgery centres between 2015 and 2018. During the operation, the responsible surgeon (most senior surgeon present) briefed the surgical team using the StOP? protocol about: progress of the operation (Status), next steps (Objectives), possible problems (Problems), and encouraged asking questions (?). Differences between baseline and intervention were analysed regarding surgical-site infections (primary outcome), mortality, unplanned reoperations, and duration of hospital stay (secondary outcomes), using inverse probability of treatment (IPT) weighting based on propensity scores.

RESULTS

In total, 8256 patients underwent surgery in the study. Endpoint data were available for 7745 patients (93.8 per cent). IPT-weighted and adjusted intention-to-treat analyses showed no differences in surgical-site infections between baseline and intervention (9.8 versus 9.6 per cent respectively; adjusted difference (AD) -0.15 (95 per cent c.i. -1.45 to 1.14) per cent; odds ratio (OR) 0.92, 95 per cent c.i. 0.83 to 1.15; P = 0.797), but there were reductions in mortality (1.6 versus 1.1 per cent; AD -0.54 (-1.04 to -0.03) per cent; OR 0.60, 0.39 to 0.92; P = 0.018), unplanned reoperations (6.4 versus 4.8 per cent; AD -1.66 (-2.69 to -0.62) per cent; OR 0.72, 0.59 to 0.89; P = 0.002), and fewer prolonged hospital stays (21.6 versus 19.8 per cent; AD -1.82 (-3.48 to -0.15) per cent; OR 0.87, 0.77 to 0.98; P = 0.024).

CONCLUSION

Short intraoperative briefings improve patient outcomes and should be performed routinely.

Intraperitoneal microbial contamination drives post-surgical peritoneal adhesions by mesothelial EGFR-signaling

Abdominal surgeries are lifesaving procedures but can be complicated by the formation of peritoneal adhesions, intra-abdominal scars that cause intestinal obstruction, pain, infertility, and significant health costs. Despite this burden, the mechanisms underlying adhesion formation remain unclear and no cure exists. Here, we show that contamination of gut microbes increases post-surgical adhesion formation. Using genetic lineage tracing we show that adhesion myofibroblasts arise from the mesothelium. This transformation is driven by epidermal growth factor receptor (EGFR) signaling. The EGFR ligands amphiregulin and heparin-binding epidermal growth factor, are sufficient to induce these changes. Correspondingly, EGFR inhibition leads to a significant reduction of adhesion formation in mice. Adhesions isolated from human patients are enriched in EGFR positive cells of mesothelial origin and human mesothelium shows an increase of mesothelial EGFR expression during bacterial peritonitis. In conclusion, bacterial contamination drives adhesion formation through mesothelial EGFR signaling. This mechanism may represent a therapeutic target for the prevention of adhesions after intra-abdominal surgery.

3D Quantitative Ablation Margins for Prediction of Ablation Site Recurrence After Stereotactic Image-Guided Microwave Ablation of Colorectal Liver Metastases: A Multicenter Study

Background

Three-dimensional (3D) volumetric ablation margin assessment after thermal ablation of liver tumors using software has been described, but its predictive value on treatment efficacy when accounting for other factors known to correlate ablation site recurrence (ASR) remains unknown.

Purpose

To investigate 3D quantitative ablation margins (3D-QAMs) as an algorithm to predict ASR within 1 year after stereotactic microwave ablation (SMWA) for colorectal liver metastases (CRLM).

Materials and Methods

Sixty-five tumors in 47 patients from a prospective multicenter study of patients undergoing SMWA for CRLM were included in this retrospective 3D-QAM analysis. Using a previously developed algorithm, 3D-QAM defined as the distribution of tumor to ablation surface distances was assessed in co-registered pre- and post-ablation CT scans. The discriminatory power and optimal cutoff values for 3D-QAM were assessed using receiver operating characteristic (ROC) curves. Multivariable logistic regression analysis using generalized estimating equations was applied to investigate the impact of various 3D-QAM outputs on 1-year ASR while accounting for other known influencing factors.

Results

Ten of the 65 (15.4%) tumors included for 3D-QAM analysis developed ASR. ROC analyses identified i) 3D-QAM <1 mm for >23% of the tumor surface, ii) 3D-QAM <5 mm for >45%, and iii) the minimal ablation margin (MAM) as the 3D-QAM outputs with optimal discriminatory qualities. The multivariable regression model without 3D-QAM yielded tumor diameter and KRAS mutation as 1-year ASR predictors. When adding 3D-QAM, this factor became the main predictor of 1-year ASR [odds ratio (OR) 21.67 (CI 2.48, 165.21) if defined as >23% <1 mm; OR 0.52 (CI 0.29, 0.95) if defined as MAM].

Conclusions

3D-QAM allows objectifiable and standardized assessment of tumor coverage by the ablation zone after SMWA. Our data shows that 3D-QAM represents the most important factor predicting ASR within 1 year after SMWA of CRLM.

Stereotactic and Robotic Minimally Invasive Thermal Ablation of Malignant Liver Tumors: A Systematic Review and Meta-Analysis

Background

Stereotactic navigation techniques aim to enhance treatment precision and safety in minimally invasive thermal ablation of liver tumors. We qualitatively reviewed and quantitatively summarized the available literature on procedural and clinical outcomes after stereotactic navigated ablation of malignant liver tumors.

Methods

A systematic literature search was performed on procedural and clinical outcomes when using stereotactic or robotic navigation for laparoscopic or percutaneous thermal ablation. The online databases Medline, Embase, and Cochrane Library were searched. Endpoints included targeting accuracy, procedural efficiency, and treatment efficacy outcomes. Meta-analysis including subgroup analyses was performed.

Results

Thirty-four studies (two randomized controlled trials, three prospective cohort studies, 29 case series) were qualitatively analyzed, and 22 studies were included for meta-analysis. Weighted average lateral targeting error was 3.7 mm (CI 3.2, 4.2), with all four comparative studies showing enhanced targeting accuracy compared to free-hand targeting. Weighted average overall complications, major complications, and mortality were 11.4% (6.7, 16.1), 3.4% (2.1, 5.1), and 0.8% (0.5, 1.3). Pooled estimates of primary technique efficacy were 94% (89, 97) if assessed at 1–6 weeks and 90% (87, 93) if assessed at 6–12 weeks post ablation, with remaining between-study heterogeneity. Primary technique efficacy was significantly enhanced in stereotactic vs. free-hand targeting, with odds ratio (OR) of 1.9 (1.2, 3.2) (n = 6 studies).

Conclusions

Advances in stereotactic navigation technologies allow highly precise and safe tumor targeting, leading to enhanced primary treatment efficacy. The use of varying definitions and terminology of safety and efficacy limits comparability among studies, highlighting the crucial need for further standardization of follow-up definitions.

Parenchymal-sparing hepatectomy for colorectal liver metastases reduces postoperative morbidity while maintaining equivalent oncologic outcomes compared to non-parenchymal-sparing resection

BACKGROUND

Modern chemotherapy and repeat hepatectomy allow to tailor the surgical strategies for the treatment of colorectal liver metastases (CRLM). This study addresses the hypothesis that parenchymal-sparing hepatectomy reduces postoperative complications while ensuring similar oncologic outcomes compared to the standardized non-parenchymal-sparing procedures.

METHODS

Clinicopathological data of patients who underwent liver resection for CRLM between 2012 and 2019 at a hepatobiliary center in Switzerland were assessed. Patients were stratified according to the tumor burden score [TBS² = (maximum tumor diameter in cm)² + (number of lesions)²)] and were dichotomized in a lower and a higher tumor burden cohort according to the median TBS. Postoperative outcomes, overall survival (OS) and recurrence-free survival (RFS) of patients following parenchymal-sparing resection (PSR) for CRLM were compared with those of patients undergoing non-PSR.

RESULTS

During the study period, 153 patients underwent liver resection for CRLM with curative intent. PSR was performed in 79 patients with TBS <4.5, and in 42 patients with TBS ≥4.5. Perioperative chemotherapy was administered in equal rates in both groups (PSR vs. non-PSR) both in TBS ≥4.5 and TBS <4.5. In patients with lower tumor burden (TBS <4.5), PSR was associated with lower overall complication rate (15.2% vs. 46.2%, p = 0.009), a trend for lower major complication rate (8.9% vs. 23.1%, p = 0.123), and shorter length of hospital stay (5 vs. 9 days, p = 0.006) in comparison to non-PSR. For TBS <4.5, PSR resulted in equivalent 5-year OS (48% vs. 39%, p = 0.479) and equivalent 5-year RFS rates (44% vs. 29%, p = 0.184) compared to non-PSR. For TBS ≥4.5, PSR resulted in lower postoperative complication rate (33.3% vs. 63.2%, p = 0.031), a trend for lower major complication rate (23.8% vs. 42.2%, p = 0.150), lower length of hospital stay (6 vs. 9 days, p = 0.005), equivalent 5-year OS (29% vs. 22%, p = 0.314), and equivalent 5-year RFS rates (29% vs. 18%, p = 0.156) compared to non-PSR. Among all patients treated with PSR, patients undergoing minimal-invasive hepatectomy had equivalent 5-year OS (42% vs. 37%, p = 0.261) and equivalent 5-year RFS (34% vs. 34%, p = 0.613) rates compared to patients undergoing open hepatectomy.

CONCLUSIONS

PSR for CRLM is associated with lower postoperative morbidity, shorter length of hospital stay, and equivalent oncologic outcomes compared to non-PSR, independently of tumor burden. Our findings suggest that minimal-invasive PSR should be considered as the preferred method for the treatment of curatively resectable CRLM, if allowed by tumor size and location.

RefluxStopTM, a novel device to address gastroesophageal reflux disease: Short-term results

Objective

To report safety, feasibility, and patient’s functional short-term outcome of novel RefluxStop anti reflux operation.

Methods

All patients (n = 20) who received laparoscopic implantation of the RefluxStop device from September 2018 to November 2020 in a university hospital were included for retrospective analysis.

Incidence of adverse device-effects and procedure-related adverse events are reported as safety endpoints.

Feasibility was assessed reporting operation duration, rate of conversion to open surgery and technically correct position of the device by control radiography during patient’s follow up. Subjective (Gastroesophageal Reflux Disease - Health Related Quality of Life (GERD-HRQL) - questionnaires; after 6 weeks and every six-month thereof) and objective data (24h-pH-manometry, barium swallows and upper endoscopies) are reported as functional outcome parameters. Comparison between values at baseline versus post-procedure follow-up are performed using the paired samples T-test, if appropriate.

Results

Median follow up was 4 (1 – 22) month. Three out of 20 patients had previous upper gastrointestinal surgery (EndoStim implantation). No serious adverse device related events occurred. One patient with dysphagia required balloon dilatation at the oesophageal gastric junction 4 weeks postoperatively.

Median duration of surgery was 85 (59-188) minutes. There was no conversion to open surgery. There was significant reduction in the mean of total GERD-HRQL score at baseline compared to 6-weeks after surgery with 23.9 and 4.3 (p &lt; 0.001) as well as at baseline and 6 month after surgery with 28.4 and 6.8 (p = 0.021), respectively. At 6 weeks follow up, all of the subjects had over 50% improvement of the GERD-HRQL score compared to baseline. One patient with acceptable device positioning developed symptom recurrence and received conversion to laparoscopic Toupet fundoplication after 10 months.

Conclusion

RefluxStop procedure seems to be a safe operation with promising short-term results. For high-level recommendation, further studies looking for long-term results and randomized comparisons to the standard anti reflux procedures like Nissen or Toupet fundoplication are required.

Surgical skill assessment using machine learning algorithms

Objective

Surgical skill is correlated with clinical outcomes. Therefore, the assessment of surgical skill is of major importance to improve clinical outcomes and increase patient safety. However, surgical skill assessment often lacks objectivity and reproducibility. Furthermore, it is time-consuming and expensive. Therefore, we developed an automated surgical skill assessment using machine learning algorithms.

Methods

Surgical skills were assessed in videos of laparoscopic cholecystectomy using a three-step machine learning algorithm. First, a three-dimensional convolutional neural network was trained to localize and classify the instruments within the videos. Second, movement patterns of the instruments were recorded over time and extracted. Third, the movement patterns were correlated with human surgical skill ratings using a linear regression model to predict surgical skill ratings automatically. Machine ratings were compared against human ratings of four board certified surgeons using a score ranging from 1 (poor skills) to 5 (excellent skills).

Results

Human raters and machine learning algorithms assessed surgical skills in 242 videos. Inter-rater reliability for human raters was excellent (79%, 95%CI 72-85%). Instrument detection showed an average precision of 78% and average recall of 82%. Machine learning algorithms showed an 87% accuracy in predicting good or poor surgical skills, when compared to human raters.

Conclusion

Machine learning algorithms can be trained to distinguish good and poor surgical skills with high accuracy.

This work was published in Sci Rep 11, 5197 (2021). https://doi.org/10.1038/s41598-021-84295-6

Comparison of long-term survivals following hepatectomy for hepatocellular carcinoma according to the time-point of recurrence and treatment modalities for recurrent disease

Objective

Disease recurrence following curatively intended hepatectomy for hepatocellular carcinoma (HCC) limits oncologic outcome. Based on the extent, location and time-point of tumor recurrence, different therapeutic modalities are available to treat recurrent HCC. Therefore, our aim was to investigate the role of these treatments and the time-point of recurrence on long-term survival.

Methods

Clinicopathological data of patients, who underwent hepatectomy for HCC at a major hepatobiliary center in Switzerland between 2012 and 2019, were assessed. Patients suffering tumor recurrence were stratified according to the treatment modalities for recurrent HCC including surgical treatment (repeat hepatectomy or liver transplantation), interventional treatment, and conservative treatment (chemotherapy or best supportive care). Groups were compared regarding to overall survival (OS). Additionally, long-term outcomes were compared between patients with early (≤ 12 months) and late (&gt; 12 months) tumor recurrence.

Results

During the study period, 159 patients underwent hepatectomy for HCC. Median follow-up time was 53 months. After a median time of seven (1-64) months, 74 patients were diagnosed with tumor recurrence (47 %). The majority of patients developed early recurrence (n = 49) and 58 patients had intrahepatic recurrence only. Treatment options were re-resection, liver transplantation, interventional methods, and palliative therapy in 5, 15, 23, and 31 patients, respectively. Surgical treatment was significantly associated with improved OS compared to interventional and conservative treatment (5-year OS: 84% vs. 39% vs. 30%, p &lt; 0.0001). OS was significantly better among patients with late recurrence compared to patients with early recurrence, irrespective of the treatment modality used for the recurrent disease (5-year OS: 70% vs. 38%, p = 0.008).

Conclusion

Repeat hepatectomy or liver transplantation for recurrent HCC following hepatectomy is associated with better long-term survival compared to interventional or conservative therapies, especially for patients with late tumor recurrence. Patients with intrahepatic HCC recurrence should be evaluated according to the extent of tumor burden, liver function, and functional status to identify the best candidates for a surgical treatment.

Parenchymal-sparing hepatectomy for colorectal liver metastases reduces postoperative morbidity while maintaining equivalent oncologic outcomes compared to non-parenchymal-sparing resection

Objective

Modern chemotherapy and repeat hepatectomy allow to tailor the surgical strategies for the treatment of colorectal liver metastases (CRLM). This study addresses the hypothesis that parenchymal-sparing hepatectomy reduces postoperative complications while ensuring similar oncologic outcomes compared to the standardized non-parenchymal-sparing procedures.

Methods

Clinicopathological data of patients who underwent liver resection for CRLM between 2012 and 2019 at a major hepatobiliary center in Switzerland were assessed. Patients were stratified according to the tumor burden score [TBS2 = (maximum tumor diameter in cm)2 + (number of lesions)2)] and were dichotomized in a lower and a higher tumor burden cohort according to the median TBS. Postoperative outcomes, overall survival (OS) and disease-free survival (DFS) of patients following parenchymal-sparing resection (PSR) for CRLM were compared with those of patients undergoing non-PSR.

Results

During the study period, 153 patients underwent liver resection for CRLM with curative intent. PSR was performed in 79 patients with TBS &lt; 4.5, and in 42 patients with TBS ≥ 4.5. In patients with lower tumor burden (TBS &lt; 4.5), PSR was associated with lower complication rate (15.2% vs. 46.2%, p = 0.009), and shorter length of hospital stay (5 vs. 9 days, p = 0.006) in comparison to non-PSR. For TBS &lt; 4.5, PSR resulted in equivalent 5-year OS (48% vs. 39%, p = 0.479) and equivalent 5-year DFS rates (DFS, 44% vs. 29%, p = 0.184) compared to non-PSR. For TBS ≥ 4.5, PSR resulted in lower postoperative complication rate (33.3% vs. 63.2%, p = 0.031), lower length of hospital stay (6 vs. 9 days, p = 0.005), equivalent 5-year OS (29% vs. 22%, p = 0.314), and equivalent 5-year DFS rates (29% vs. 22%, p = 0.896) compared to non-PSR. Among all patients treated with PSR, patients undergoing minimal-invasive hepatectomy had equivalent 5-year OS (42% vs. 37%, p = 0.261) and equivalent 5-year DFS (34% vs. 34%, p = 0.613) rates compared to patients undergoing open hepatectomy.

Conclusion

PSR for CRLM is associated with lower postoperative morbidity, shorter length of hospital stay, and equivalent oncologic outcomes compared to non-PSR independently from tumor burden. Our findings suggest that minimal-invasive PSR should be considered as the preferred method for the treatment of curatively resectable CRLM if allowed by tumor size and location.

The effect of mesenteric defect closure on internal hernias and small bowel obstruction in patients undergoing colorectal surgery: A systematic review and meta-analysis

Objective

Internal hernias (IH) are potentially severe complications after colorectal surgery and may lead to small bowel obstruction (SBO). However, the impact of mesenteric defect closure (MDC) on IH and SBO is currently unclear. The aim of this systematic review and meta-analysis was, therefore, to investigate the effect of MDC on IH and SBO in patients undergoing laparoscopic and open colorectal surgery.

Methods

Ovid Medline, PubMed, and Embase databases were searched. Studies reporting MDC in colorectal surgery were enclosed in the systematic review. Meta-analysis included studies that assessed the effect of MDC vs. non-closure (non-MDC) on IH and SBO. Meta-analysis was performed using a random effect model. Results of individual studies were summarized as ranges. Effect sizes were described as odds ratios (OR) with 95% confidence intervals (CI).

Results

Literature search revealed a total of 344 abstracts. Of these, 16 studies met the inclusion criteria. Included studies comprised a total of 10,068 patients and were published between 2009 and 2019. The incidence of IH and SBO as a composite outcome ranged from 0.0 to 3.5%, whereas the incidence of IH and SBO as single outcomes ranged from 0.0 to 2.7% and 0.0 to 1.7%, respectively. If IH occurred, reoperation was required in 66-100% with additional bowel resections in 20-100% and stoma-formation in 17-50%. The complication rate after reoperations was 25-100% and mortality 0-25%. Meta-analysis including four studies revealed no statistically significant effect of MDC on the composite outcome of IH and SBO (OR 0.25, 95% CI 0.04-1.77) and SBO as a single outcome (three studies, OR 0.48, 95% CI 0.04-5.49). The risk for IH as a single outcome was significantly lower in the MDC group (three studies, OR 0.15, 95% CI 0.02-0.92). Heterogeneity of the studies included was low to moderate for the composite outcome, as well as for IH and SBO as single outcomes (I2 40.3%, 0.0%, and 45.7%, respectively).

Conclusion

In current meta-analysis, MDC was not significantly associated with the composite outcome of IH and SBO in patients undergoing colorectal surgery. However, MDC significantly reduced the risk for IH. Based on these results, the benefit of MDC in colorectal surgery remains unclear and needs to be addressed in further studies.

Damage-control surgery in patients with non-traumatic abdominal emergencies: A meta-analysis

Objective

After the successful implementation in trauma patients, damage control surgery (DCS) is being increasingly used in non-traumatic abdominal emergencies, too. However, non-trauma DCS (NT-DCS) is currently a matter of debate and has not yet been comprehensively assessed. The aim of this meta-analysis was to investigate the effect of NT-DCS on mortality in patients with abdominal emergencies.

Methods

Systematic literature search using PubMed. Original articles addressing mortality in patients undergoing NT-DCS or non-trauma conventional surgery (NT-CS) for abdominal emergencies were included. Descriptive statistics and two meta-analyses were performed. Meta-analysis 1 compared mortality in patients undergoing NT-DCS vs. NT-CS. Meta-analysis 2 assessed the observed vs. expected mortality rate, based on APACHE, POSSUM and SAPS scores, in the NT-DCS group. Continuous and categorical variables were reported as weighted means and proportions. Effect sizes were described as risk differences (RD) with 95% confidence intervals (CI).

Results

Literature search revealed 1314 articles. Of these, 21 studies published 2004-2019 were included. NT-DCS was performed in 1238 and NT-CS in 936 patients. In the NT-DCS vs. NT-CS group mean age was 61.0 vs. 64.9 years and the proportion of male patients 58.6% vs. 52.9%, respectively. Most frequent indications for NT-DCS were hollow viscus perforation (28.4%), mesenteric ischemia (26.5%), anastomotic leak (19.6%), haemorrhage (18.4%), abdominal compartment syndrome (17.4%), bowel obstruction (15.5%), and pancreatitis (13.1%). In meta-analysis 1, mortality was not significantly different in the NT-DCS vs. NT-CS group (RD 0.09, 95% CI -0.06/0.24). Meta-analysis 2 revealed a significantly lower observed than the expected mortality rate in patients undergoing NT-DCS (RD -0.18, 95 % CI -0.29/-0.06). Heterogeneity of included studies was high in both meta-analyses (I2=89.0% and 79.9%, respectively).

Conclusion

This meta-analysis revealed no significantly different mortality in patients with abdominal emergencies undergoing NT-DCS vs. NT-CS. However, observed mortality was significantly lower than the expected mortality rate in the NT-DCS group, suggesting a benefit of the DCS approach. Based on these results, the effect of DCS in patients with non-traumatic abdominal emergencies remains unclear. Further prospective investigation into this topic is warranted.

Major postoperative complications increase tumor recurrence rate and diminish long-term survival following resection for pancreatic ductal adenocarcinoma

Objective

Major complications have been associated with worse oncologic outcomes following resection for several gastrointestinal malignancies. However, the impact of major postoperative morbidity on the survival of patients undergoing resection for pancreatic ductal adenocarcinoma (PDAC) remains unclear.

Methods

Clinicopathological data of patients who underwent resection for PDAC between 2014 and 2019 in a major swiss hepatopancreatobiliary center were assessed. We evaluated the disease-free (DFS) and overall survival (OS) of patients suffering a major postoperative complication (grade-3 or higher within 90 days according to Clavien-Dindo classification) in comparison to those of patients without any major postoperative adverse events.

Results

During the study period, 186 patients underwent resection for PDAC with curative intent. Pancreatoduodenectomy, distal pancreatectomy, and total pancreatectomy were performed in 66%, 12%, and 22% of patients, respectively. Major 90-day postoperative morbidity and mortality rate were 21.5% and 4.3%, respectively. After excluding patients who died within 90 days, major postoperative morbidity significantly increased the length of hospital stay [median 22 (8-66) days vs. 13 (5-26) days, p &lt; 0.0001] resulting in a delay of returning to intended oncologic treatment and reducing the likelihood of receiving adjuvant chemotherapy (56% vs. 83%, p = 0.001). Postoperative major complications were associated with significantly worse DFS (median DFS 10 vs. 16 months, hazard ratio 1.9, 95% confidence interval 1.91-2.96, p = 0.004) and worse OS (median OS 14 vs. 37 months, hazard ratio 1.7, 95% confidence interval 1.02-2.75, p = 0.04) in multivariate analysis.

Conclusion

Major postoperative complications promote tumor recurrence following resection for PDAC, thus limiting long-term survival. Careful patient selection and optimized complication management may reduce postoperative morbidity, thereby lowering its negative impact on oncologic prognosis.

Optimal liver metabolism and proliferation require the tight junction protein claudin-3

Objective

The expression of hepatic tight junction proteins and their contribution to homeostasis and regeneration remained largely unexplored. Here, we determine the cell type specific expression of tight junction genes in murine livers. We further explore the regulation and functional importance of the transmembrane protein CLDN3 in normal and regenerating livers.

Methods

Murine livers were used for tissue- and single cell RNA-seq. CLDN3 localization was determined by immunofluorescence. CLDN3+/+ or CLDN3-/- livers were analysed by electron microscopy, fluorescence-activated cell sorting and liquid chromatography mass spectrometry. Lipid content was quantified with oil-red. Mice were subjected to 2/3 partial hepatectomy. Proliferation was quantified with Ki67 and pHH3 stainings. Cell cycle gene expression was determined by RT-qPCR. Barrier impairments were assessed with total bile acid measurements. Differential gene expression was analysed by tissue RNAseq with DESeq2.

Results

We determined the profile of tight junction gene expression the main liver cell types, showing that tight junction transcripts can be found in hepatocytes and cholangiocytes but also on non-parenchymal cell populations. CLDN3 was among the highly expressed- and regulated genes in native and regenerating livers. CLDN3 had a zonated expression pattern. CLDN3-/- mice had microscopically intact tight junctions, but showed significantly downregulated hepatic energy metabolism and suboptimal cell proliferation in the regeneration model.

Conclusion

Our data suggests a functional role of CLDN3 for maintenance of energy homeostasis and optimal regeneration, proving that the function of hepatic tight junction proteins extends beyond basic membrane sealing.

Endoscopic ultrasound-guided hepaticogastrostomy vs. ERCP for preoperative biliary drainage in patients undergoing pancreatic resection

Objective

Preoperative bile drainage in patients with obstructive jaundice due to pancreatic head malignancy is needed, if pancreatic head resection cannot be performed in a timely fashion. The safety and efficacy of ultrasound-guided hepaticogastrostomy (HGS) as an alternative to the established endoscopic retrograde cholangio-pancreatography (ERCP) with stent placement needs further investigation.

Methods

Clinicopathological data of patients who underwent partial or total pancreaticoduodenectomy between January 2017 and December 2019 in a major swiss hepatopancreatobiliary center were assessed. We compared the HGS with ERCP/stent regarding the kinetics of bilirubin decrease, the procedure-related morbidity, and the postoperative surgical outcomes.

Results

During the study period, 102 patients underwent pancreaticoduodenectomy or total pancreatectomy for pancreatic malignancy. Preoperative bile drainage was performed in 65 patients (20 HGS, 45 ERCP). HGS was associated with a faster (6 vs. 10 days, P = 0.042) and more effective (133 µmol/L vs. 101 µmol/L, P = 0.037) reduction of the serum bilirubin levels. HGS was safe and did not differ from ERCP with stent placement concerning post-interventional complications (P = 0.565), postoperative mortality (P = 0.996) and postoperative morbidity (P = 0.896), including infectious complications (wound infection, P = 0.662/ intra-abdominal abscess, P = 0.587), severe pancreatic fistula (P = 0.587), bile leak (P = 0.131), and postoperative hemorrhage (P = 0.886).

Conclusion

HGS performed in a specialized multidisciplinary hepatopancreatobiliary center is feasible and safe and may result in more accelerated and effective bile drainage compared to the established ERCP. In patients with obstructive jaundice related to pancreatic malignancy unable to undergo adequate bile drainage by ERCP, HGS may be an effective alternative method enabling surgery in a timely manner.

The human vault RNA enhances tumorigenesis and chemoresistance through the lysosome in hepatocellular carcinoma

The small non-coding VTRNA1-1 (vault RNA 1–1) is known to confer resistance to apoptosis in several malignant cell lines and to also modulate the macroautophagic/autophagic flux in hepatocytes, thus highlighting its pro-survival role. Here we describe a new function of VTRNA1-1 in regulating in vitro and in vivo tumor cell proliferation, tumorigenesis and chemoresistance. Knockout (KO) of VTRNA1-1 in human hepatocellular carcinoma cells reduced nuclear localization of TFEB (transcription factor EB), leading to a downregulation of the coordinated lysosomal expression and regulation (CLEAR) network genes and lysosomal compartment dysfunction. We demonstrate further that impaired lysosome function due to loss of VTRNA1-1 potentiates the anticancer effect of conventional chemotherapeutic drugs. Finally, loss of VTRNA1-1 reduced drug lysosomotropism allowing higher intracellular compound availability and thereby significantly reducing tumor cell proliferation in vitro and in vivo. These findings reveal a so far unknown role of VTRNA1-1 in the intracellular catabolic compartment and describe its contribution to lysosome-mediated chemotherapy resistance.

Abbreviations: ATP6V0D2: ATPase H+ transporting V0 subunit d2; BafA: bafilomycin A1; CLEAR: coordinated lysosomal expression and regulation; CQ: chloroquine; DMSO: dimethyl sulfoxide; GST-BHMT: glutathionine S-transferase N-terminal to betaine–homocysteine S-methyltransferase; HCC: hepatocellular carcinoma; LAMP1: lysosomal associated membrane protein 1; LLOMe: L-leucyl-L-leucine methyl ester; MAP1LC3B/LC3: microtubule associated protein 1 light chain 3 beta; MAPK: mitogen-activated protein kinase; MITF: melanocyte inducing transcription factor; MTT: 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide; ncRNA: non-coding RNA; RNP: ribonucleoprotein; SF: sorafenib; SQSTM1/p62: sequestosome 1; STS: staurosporine; tdRs: tRNA-derived RNAs; TFE3: transcription factor binding to IGHM enhancer 3; TFEB: transcription factor EB; vtRNA: vault RNA transcript.

Loss of Claudin-3 Impairs Hepatic Metabolism, Biliary Barrier Function, and Cell Proliferation in the Murine Liver

BACKGROUND & AIMS

Tight junctions in the liver are essential to maintain the blood-biliary barrier, however, the functional contribution of individual tight junction proteins to barrier and metabolic homeostasis remains largely unexplored. Here, we describe the cell type-specific expression of tight junction genes in the murine liver, and explore the regulation and functional importance of the transmembrane protein claudin-3 in liver metabolism, barrier function, and cell proliferation.

METHODS

The cell type-specific expression of hepatic tight junction genes is described using our mouse liver single-cell sequencing data set. Differential gene expression in Cldn3-/- and Cldn3+/+ livers was assessed in young and aged mice by RNA sequencing (RNA-seq), and hepatic tissue was analyzed for lipid content and bile acid composition. A surgical model of partial hepatectomy was used to induce liver cell proliferation.

RESULTS

Claudin-3 is a highly expressed tight junction protein found in the liver and is expressed predominantly in hepatocytes and cholangiocytes. The histology of Cldn3-/- livers showed no overt phenotype, and the canalicular tight junctions appeared intact. Nevertheless, by RNA-seq we detected a down-regulation of metabolic pathways in the livers of Cldn3-/- young and aged mice, as well as a decrease in lipid content and a weakened biliary barrier for primary bile acids, such as taurocholic acid, taurochenodeoxycholic acid, and taurine-conjugated muricholic acid. Coinciding with defects in the biliary barrier and lower lipid metabolism, there was a diminished hepatocyte proliferative response in Cldn3-/- mice after partial hepatectomy.

CONCLUSIONS

Our data show that, in the liver, claudin-3 is necessary to maintain metabolic homeostasis, retention of bile acids, and optimal hepatocyte proliferation during liver regeneration. The RNA-seq data set can be accessed at: https://www.ncbi.nlm.nih.gov/geo/query/acc.cgi?acc=GSE159914.

Synergistic effect of the TLR5 agonist CBLB502 and its downstream effector IL-22 against liver injury

The toll-like receptor 5 (TLR5) agonist, CBLB502/Entolimod, is a peptide derived from bacterial flagellin and has been shown to protect against radiation-induced tissue damage in animal models. Here we investigated the protective mechanism of CBLB502 in the liver using models of ischemia-reperfusion injury and concanavalin A (ConA) induced immuno-hepatitis. We report that pretreatment of mice with CBLB502 provoked a concomitant activation of NF-κB and STAT3 signaling in the liver and reduced hepatic damage in both models. To understand the underlying mechanism, we screened for cytokines in the serum of CBLB502 treated animals and detected high levels of IL-22. There was no transcriptional upregulation of IL-22 in the liver, rather it was found in extrahepatic tissues, mainly the colon, mesenteric lymph nodes (MLN), and spleen. RNA-seq analysis on isolated hepatocytes demonstrated that the concomitant activation of NF-κB signaling by CBLB502 and STAT3 signaling by IL-22 produced a synergistic cytoprotective transcriptional signature. In IL-22 knockout mice, the loss of IL-22 resulted in a decrease of hepatic STAT3 activation, a reduction in the cytoprotective signature, and a loss of hepatoprotection following ischemia-reperfusion-induced liver injury. Taken together, these findings suggest that CBLB502 protects the liver by increasing hepatocyte resistance to acute liver injury through the cooperation of TLR5-NF-κB and IL-22-STAT3 signaling pathways.

Primordial GATA6 macrophages function as extravascular platelets in sterile injury

Most multicellular organisms have a major body cavity that harbors immune cells. In primordial species such as purple sea urchins, these cells perform phagocytic functions but are also crucial in repairing injuries. In mammals, the peritoneal cavity contains large numbers of resident GATA6⁺ macrophages, which may function similarly. However, it is unclear how cavity macrophages suspended in the fluid phase (peritoneal fluid) identify and migrate toward injuries. In this study, we used intravital microscopy to show that cavity macrophages in fluid rapidly form thrombus-like structures in response to injury by means of primordial scavenger receptor cysteine-rich domains. Aggregates of cavity macrophages physically sealed injuries and promoted rapid repair of focal lesions. In iatrogenic surgical situations, these cavity macrophages formed extensive aggregates that promoted the growth of intra-abdominal scar tissue known as peritoneal adhesions.

Automation of surgical skill assessment using a three-stage machine learning algorithm

Surgical skills are associated with clinical outcomes. To improve surgical skills and thereby reduce adverse outcomes, continuous surgical training and feedback is required. Currently, assessment of surgical skills is a manual and time-consuming process which is prone to subjective interpretation. This study aims to automate surgical skill assessment in laparoscopic cholecystectomy videos using machine learning algorithms. To address this, a three-stage machine learning method is proposed: first, a Convolutional Neural Network was trained to identify and localize surgical instruments. Second, motion features were extracted from the detected instrument localizations throughout time. Third, a linear regression model was trained based on the extracted motion features to predict surgical skills. This three-stage modeling approach achieved an accuracy of 87 ± 0.2% in distinguishing good versus poor surgical skill. While the technique cannot reliably quantify the degree of surgical skill yet it represents an important advance towards automation of surgical skill assessment.

Mesh fixation to fascia during incisional hernia repair results in increased prevalence of pain at long-term follow up: a multicenter propensity score matched prospective observational study

BACKGROUND

Patient-reported outcomes such as postoperative pain are critical for the evaluation of outcomes after incisional hernia repair. The aim of this study is to determine the long-term impact of mesh fixation on postoperative pain in patients operated by open and laparoscopic technique.

METHODS

A multicenter prospective observational cohort study was conducted from September 2011 until March 2016 in nine hospitals across Switzerland. Patients undergoing elective incisional hernia repair were included in this study and stratified by either laparoscopic or open surgical technique. Propensity score matching was applied to balance the differences in baseline characteristics between the treatment groups. Clinical follow-up was conducted 3, 12 and 36 months postoperatively to detect hernia recurrence, postoperative pain and complications.

RESULTS

Three-hundred-sixty-one patients were included into the study. No significant differences in hernia recurrence and pain at 3, 12 and 36 months postoperatively were observed when comparing the laparoscopic with the open treatment group. Mesh fixation by sutures to fascia versus other mesh fixation led to significantly more pain at 36 months postoperatively (32.8% vs 15.7%, p = 0.025).

CONCLUSIONS

At long-term follow-up, no difference in pain was identified between open and laparoscopic incisional hernia repair. Mesh fixation by sutures to fascia was identified to be associated with increased pain 36 months after surgery. Omitting mesh fixation by sutures to the fascia may reduce long-term postoperative pain after hernia repair.

Colon cancer cells produce immunoregulatory glucocorticoids

Expression or release of immunosuppressive molecules may protect tumor cells from the recognition and destruction by the immune system. New findings indicate that colorectal tumors produce immunoregulatory glucocorticoids and thereby suppress immune cell activation. The nuclear receptor LRH-1 plays a critical role in the regulation of colorectal tumor proliferation and glucocorticoid synthesis.