Intrinsic pulmonary sealing, its mechanisms and impact on validity and translational value of lung sealant studies: a pooled analysis of animal studies.

Background: No validated and standardized animal models of pulmonary air leakage (PAL) exist for testing aerostatic efficacy of lung sealants. Lack of negative control groups in published studies and intrinsic sealing mechanisms of healthy animal lungs might contribute to a translational gap, leading to poor clinical results. This study aims to address the impact of intrinsic sealing mechanisms on the validity of PAL models, and investigate the conditions required for an ovine model of PAL for lung sealant testing. Methods: An ovine acute aerostasis model was developed, consisting of a bilateral thoracotomy with lesion creation, chest tube insertion and monitoring of air leaks using digital drains (≥80 minutes), under spontaneous respiration. Healthy mixed-breed adult female sheep were used and all in vivo procedures were performed under terminal anesthesia. Superficial parenchymal lesions were tested post-mortem and in vivo, extended lesions including bronchioles (deep bowl-shaped and sequential lung amputation lesions) were tested in vivo. Experiment outcomes include air leakage (AL), minimal leaking pressure (MLP) and histology. Results: Two post-mortem (N=4 superficial parenchymal lesions) and 10 in vivo experiments (N=5 superficial parenchymal and N=16 lesions involving bronchioles) were performed. In contrast to the post-mortem model, superficial parenchymal lesions in vivo showed less air leak [mean flow ± standard deviation (SD): 760±693 vs. 42±33 mL/min, P=0.055]. All superficial parenchymal lesions in vivo sealed intrinsically within a median time of 20 minutes [interquartile range (IQR), 10-75 minutes]. Histology of the intrinsic sealing layer revealed an extended area of alveolar collapse below the incision with intra-alveolar hemorrhage. Compared to superficial parenchymal lesions in vivo, lesions involving bronchioles induced significantly higher air leak post-operatively (normalized mean flow ± SD: 459±221 mL/min, P=0.003). At termination, 5/9 (55.6%) were still leaking (median drain time: 273 minutes, IQR, 207-435 minutes), and intrinsic sealing for the remaining lungs occurred within a median of 115 minutes (IQR, 52-245 minutes). Conclusions: Lung parenchyma of healthy sheep shows a strong intrinsic sealing mechanism, explained pathologically by an extended area of alveolar collapse, which may contribute to a translational gap in lung sealant research. A meaningful ovine model has to consist of deep lesions involving bronchioles of >⌀1.5 mm. Further research is needed to develop a standardized PAL model, to improve clinical effectiveness of lung sealants.

[Adhesions after abdominal surgery: developments in diagnosis and treatment]. / Adhesies na een buikoperatie.

Adhesions are a form of internal scar tissue, that develops in 70-90% of patients undergoing abdominal surgery. Although most adhesions are asymptomatic, adhesions cause a lifelong risk for complications, including adhesive small bowel obstruction (ASBO), chronic pain, infertility and difficulties during reoperations. ASBO is an abdominal emergency, resulting in hospital readmissions and a reoperation in 30-50% of cases. ASBO is associated with a high risk of recurrence. The risk of recurrence can be reduced by the use of adhesion barriers during operative treatment. Recent studies have demonstrated that elective adhesiolysis with use of adhesion barrier for pain is effective in selected patients. Novel imaging techniques, such as cineMRI, can help select patients in whom adhesiolysis is safe and effective. Reconstructive surgery with adhesiolysis is seldom performed for acquired infertility. However, this treatment has potential benefits over IVF in young couples.

ECLAPTE: Effective Closure of LAParoTomy in Emergency-2023 World Society of Emergency Surgery guidelines for the closure of laparotomy in emergency settings.

Laparotomy incisions provide easy and rapid access to the peritoneal cavity in case of emergency surgery. Incisional hernia (IH) is a late manifestation of the failure of abdominal wall closure and represents frequent complication of any abdominal incision: IHs can cause pain and discomfort to the patients but also clinical serious sequelae like bowel obstruction, incarceration, strangulation, and necessity of reoperation. Previous guidelines and indications in the literature consider elective settings and evidence about laparotomy closure in emergency settings is lacking. This paper aims to present the World Society of Emergency Surgery (WSES) project called ECLAPTE (Effective Closure of LAParoTomy in Emergency): the final manuscript includes guidelines on the closure of emergency laparotomy.

Variation in the management of adhesive small bowel obstruction in the Netherlands: a prospective cross-sectional study.

BACKGROUND: ASBO is a frequent abdominal surgical emergency and a leading cause of morbidity and mortality in emergency surgery. The aim of this study is to provide insight into the current management of adhesive small bowel obstruction (ASBO) and associated outcomes. METHODS AND MATERIALS: A nationwide prospective cross-sectional cohort study was conducted. All patients with clinical signs of ASBO admitted to participating Dutch hospitals were included during a 6 months inclusion period between April 2019 and December 2020. Ninety-day clinical outcomes were described and compared for nonoperative management (NOM) and laparoscopic and open surgery. RESULTS: In 34 participating hospitals, 510 patients were included, of whom 382 (74.9%) had a definitive diagnosis of ASBO. Initial management consisted of emergency surgery in 71 (18.6%) patients and NOM in 311 (81.4%) patients, 119 (31.1%) of whom required delayed surgery after failure of NOM. Surgical interventions started laparoscopically in 51.1%, of which 36.1% were converted to laparotomy. Intentional laparoscopy resulted in shorter hospital stays compared with open surgery (median 8.0 vs. 11.0 days; P <0.001) and comparable hospital mortality (5.2 vs. 4.3%; P =1.000). Oral water-soluble contrast use was associated with a decreased length of stay ( P =0.0001). Hospital stay for surgical patients was shorter in patients who were operated on within 72 h of admission ( P <0.001). CONCLUSION: This nationwide cross-sectional study demonstrates shorter hospital stay in ASBO patients who received water-soluble contrast, were operated within 72 h of admission or were operated with minimally invasive techniques. Results may support the standardization of ASBO treatment.

Quantifiable Measures of Abdominal Wall Motion for Quality Assessment of Cine-MRI Slices in Detection of Abdominal Adhesions.

Abdominal adhesions present a diagnostic challenge, and classic imaging modalities can miss their presence. Cine-MRI, which records visceral sliding during patient-controlled breathing, has proven useful in detecting and mapping adhesions. However, patient movements can affect the accuracy of these images, despite there being no standardized algorithm for defining sufficiently high-quality images. This study aims to develop a biomarker for patient movements and determine which patient-related factors influence movement during cine-MRI. Included patients underwent cine-MRI to detect adhesions for chronic abdominal complaints, data were collected from electronic patient files and radiologic reports. Ninety slices of cine-MRI were assessed for quality, using a five-point scale to quantify amplitude, frequency, and slope, from which an image-processing algorithm was developed. The biomarkers closely correlated with qualitative assessments, with an amplitude of 6.5 mm used to distinguish between sufficient and insufficient-quality slices. In multivariable analysis, the amplitude of movement was influenced by age, sex, length, and the presence of a stoma. Unfortunately, no factor was changeable. Strategies for mitigating their impact may be challenging. This study highlights the utility of the developed biomarker in evaluating image quality and providing useful feedback for clinicians. Future studies could improve diagnostic quality by implementing automated quality criteria during cine-MRI.

Predicting long-term risk of reoperations following abdominal and pelvic surgery: a nationwide retrospective cohort study.

BACKGROUND: The risk of reoperations after abdominal and pelvic surgery is multifactorial and difficult to predict. The risk of reoperation is frequently underestimated by surgeons as most reoperations are not related to the initial procedure and diagnosis. During reoperation, adhesiolysis is often required, and patients have an increased risk of complications. Therefore, the aim of this study was to provide an evidence-based prediction model based on the risk of reoperation. MATERIALS AND METHODS: A nationwide cohort study was conducted including all patients undergoing an initial abdominal or pelvic operation between 1 June 2009 and 30 June 2011 in Scotland. Nomograms based on multivariable prediction models were constructed for the 2-year and 5-year overall risk of reoperation and risk of reoperation in the same surgical area. Internal cross-validation was applied to evaluate reliability. RESULTS: Of the 72 270 patients with an initial abdominal or pelvic surgery, 10 467 (14.5%) underwent reoperation within 5 years postoperatively. Mesh placement, colorectal surgery, diagnosis of inflammatory bowel disease, previous radiotherapy, younger age, open surgical approach, malignancy, and female sex increased the risk of reoperation in all the prediction models. Intra-abdominal infection was also a risk factor for the risk of reoperation overall. The accuracy of the prediction model of risk of reoperation overall and risk for the same area was good for both parameters ( c -statistic=0.72 and 0.72). CONCLUSIONS: Risk factors for abdominal reoperation were identified and prediction models displayed as nomograms were constructed to predict the risk of reoperation in the individual patient. The prediction models were robust in internal cross-validation.

Evaluating and developing sealants for the prevention of pulmonary air leakage: A systematic review of animal models.

Sealants may provide a solution for pulmonary air leakage (PAL), but their clinical application is debatable. For sealant comparison, standardized animal models are lacking. This systematic review aims to assess methodology and quality of animal models for PAL and sealant evaluation. All animal models investigating lung sealing devices (e.g., staplers, glues, energy devices) to prevent or treat PAL were retrieved systematically from Embase, Pubmed and Web of science. Methodological study characteristics, risk of bias, reporting quality and publication bias were assessed. A total of 71 studies were included (N = 75 experiments, N = 1659 animals). Six different species and 18 strains were described; 92% of experiments used healthy animals, disease models were used in only six studies. Lesions to produce PAL were heterogenous, and only 11 studies used a previously reported technique, encompassing N = 5 unique lesions. Clinically relevant outcomes were used in the minority of studies (imaging 16%, air leak 10.7%, air leak duration 4%). Reporting quality was poor, but revealed an upward trend per decade. Overall, high risk of bias was present, and only 18.7% used a negative control group. All but one study without control groups claimed positive outcomes (95.8%), in contrast to 84.3% using positive or negative control groups, which also concluded equivocal, adverse or inconclusive outcomes. In conclusion, animal studies evaluating sealants for prevention of PAL are heterogenous and of poor reporting quality. Using negative control groups, disease models and quantifiable outcomes seem important to increase validity and relevance. Further research is needed to reach consensus for model development and standardization.

Efficacy of a novel polyoxazoline-based hemostatic patch in liver and spleen surgery.

BACKGROUND: A new hemostatic sealant based on a N-hydroxy-succinimide polyoxazoline (NHS-POx) polymer was evaluated to determine hemostatic efficacy and long-term wound healing and adverse effects in a large animal model of parenchymal organ surgical bleeds. METHODS: Experiment 1 included 20 pigs that were treated with two NHS-POx patch prototypes [a gelatin fibrous carrier (GFC) with NHS-POx and an oxidized regenerated cellulose (ORC) with poly(lactic-co-glycolic acid)-NHS-POx:NU-POx (nucleophilically activated polyoxazoline)], a blank gelatin patch (GFC Blank), TachoSil® and Veriset™ to stop moderate liver and spleen punch bleedings. After various survival periods (1-6 weeks), pigs were re-operated to evaluate patch degradation and parenchymal healing. During the re-operation, experiment 2 was performed: partial liver and spleen resections with severe bleeding, and hemostatic efficacy was evaluated under normal and heparinized conditions of the two previous prototypes and one additional NHS-POx patch. In the third experiment an improved NHS-POx patch (GATT-Patch; GFC-NHS-POx and added 20% as nucleophilically activated polyoxazoline; NU-POx) was compared with TachoSil®, Veriset™ and GFC Blank on punch bleedings and partial liver and spleen resections for rapid (10s) hemostatic efficacy. RESULTS: NHS-POx-based patches showed better (GFC-NHS-POx 83.1%, ORC-PLGA-NHS-POx: NU-POx 98.3%) hemostatic efficacy compared to TachoSil® (25.0%) and GFC Blank (43.3%), and comparable efficacy with Veriset™ (96.7%) on moderate standardized punch bleedings on liver and spleen. All patches demonstrated gradual degradation over 6 weeks with a reduced local inflammation rate and an improved wound healing. For severe bleedings under non-heparinized conditions, hemostasis was achieved in 100% for Veriset™, 40% for TachoSil and 80-100% for the three NHS-POx prototypes; similar differences between patches remained for heparinized conditions. In experiment 3, GATT-Patch, Veriset™, TachoSil and GFC Blank reached hemostasis after 10s in 100%, 42.8%, 7.1% and 14.3%, respectively, and at 3 min in 100%, 100%, 14.3% and 35.7%, respectively, on all liver and spleen punctures and resections. CONCLUSIONS: NHS-POx-based patches, and particularly the GATT-Patch, are fast in achieving effective hemostatic sealing on standardized moderate and severe bleedings without apparent long-term adverse events.

Inter- and Intra-Observer Variability and the Effect of Experience in Cine-MRI for Adhesion Detection.

Cine-MRI for adhesion detection is a promising novel modality that can help the large group of patients developing pain after abdominal surgery. Few studies into its diagnostic accuracy are available, and none address observer variability. This retrospective study explores the inter- and intra-observer variability, diagnostic accuracy, and the effect of experience. A total of 15 observers with a variety of experience reviewed 61 sagittal cine-MRI slices, placing box annotations with a confidence score at locations suspect for adhesions. Five observers reviewed the slices again one year later. Inter- and intra-observer variability are quantified using Fleiss' (inter) and Cohen's (intra) κ and percentage agreement. Diagnostic accuracy is quantified with receiver operating characteristic (ROC) analysis based on a consensus standard. Inter-observer Fleiss' κ values range from 0.04 to 0.34, showing poor to fair agreement. High general and cine-MRI experience led to significantly (p < 0.001) better agreement among observers. The intra-observer results show Cohen's κ values between 0.37 and 0.53 for all observers, except one with a low κ of -0.11. Group AUC scores lie between 0.66 and 0.72, with individual observers reaching 0.78. This study confirms that cine-MRI can diagnose adhesions, with respect to a radiologist consensus panel and shows that experience improves reading cine-MRI. Observers without specific experience adapt to this modality quickly after a short online tutorial. Observer agreement is fair at best and area under the receiver operating characteristic curve (AUC) scores leave room for improvement. Consistently interpreting this novel modality needs further research, for instance, by developing reporting guidelines or artificial intelligence-based methods.

Effect modifiers of virtual reality in pain management: a systematic review and meta-regression analysis.

ABSTRACT: There is a rapidly growing body of evidence for the application of virtual reality (VR) in pain management, however, with varying effectiveness. Little is known about patient-related and VR-related factors affecting efficacy of VR. A systematic review and meta-analysis was performed including 122 randomised controlled trials (9138 patients), reporting on subjectively reported pain scores comparing an immersive VR intervention to a non-VR control group. Virtual reality significantly reduced pain in the pooled analysis (standardized mean difference = -0.65, 95% CI -0.76 to -0.54, P < 0.001). Subgroup analyses showed no significant differences between type of pain, ie, VR effects were similar in acute, chronic, and procedural pain conditions. Univariate and multivariate meta-regression analyses were performed to investigate the effect of intervention, patient, and pain characteristics on VR. Virtual reality effectively reduced pain, especially in patients reporting moderate to severe pain and in younger subjects. Studies comparing VR with a control group receiving no distraction methods were associated with higher effect sizes. The effect of VR was not related to a specific frequency or duration of use. Type of software and interaction level were related to VR effects in the univariable, but not in the multivariable, meta-regression analysis. Heterogeneity was considerable for all meta-analyses, and risk of bias was moderate to high in most included studies. Studies on mechanisms behind VR analgesia in younger patients and patients reporting moderate to severe pain are recommended to confirm our hypotheses while taking into account risk of bias and the comparator. Optimal application of VR using treatment modules for long-term pain conditions are an important issue for future research.

Elective adhesiolysis for chronic abdominal pain reduces long-term risk of adhesive small bowel obstruction.

BACKGROUND: Selected patients with adhesion-related chronic abdominal pain can be treated effectively by adhesiolysis with the application of adhesion barriers. These patients might also have an increased risk to develop adhesive small bowel obstruction (ASBO). It is unknown how frequently these patients develop ASBO, and how elective adhesiolysis for pain impacts the risk of ASBO. METHODS: Patients with adhesion-related chronic pain were included in this cohort study with long-term follow-up. The diagnosis of adhesions was confirmed using CineMRI. The decision for operative treatment of adhesions was made by shared agreement based on the correlation of complaints with CineMRI findings. The primary outcome was the 5-years incidence of readmission for ASBO. Incidence was compared between patients with elective adhesiolysis and those treated non-operatively and between patients with and without previous ASBO. Univariable and multivariable Cox regression analysis was performed to identify predictive factors for ASBO. Secondary outcomes included reoperation for ASBO and self-reported pain and other abdominal symptoms. RESULTS: A total of 122 patients were included, 69 patients underwent elective adhesiolysis. Thirty patients in both groups had previous episodes of ASBO in history. During 5-year follow-up, the readmission rate for ASBO was 6.5% after elective adhesiolysis compared to 26.9% after non-operative treatment (p = 0.012). These percentages were 13.3% compared to 40% in the subgroup of patients with previous episodes of ASBO (p = 0.039). In multivariable analysis, elective adhesiolysis was associated with a decreased risk of readmission for ASBO with an odds ratio of 0.21 (95% CI 0.07-0.65), the risk was increased in patients with previous episodes with a odds ratio of 19.2 (95% CI 2.5-144.4). There was no difference between the groups in the prevalence of self-reported abdominal pain. However, in surgically treated patients the impact of pain on daily activities was lower, and the incidence of other symptoms was lower. CONCLUSION: More than one in four patients with chronic adhesion-related pain develop episodes of ASBO when treated non-operatively. Elective adhesiolysis reduces the incidence of ASBO in patients with chronic adhesion-related symptoms, both in patients with and without previous episodes of ASBO in history. Trial registration The study was registered at Clinicaltrials.gov under NCT01236625.

The Influence of Irreversible Electroporation Parameters on the Size of the Ablation Zone and Thermal Effects: A Systematic Review.

Introduction: The aim of this study was to review the effect of irreversible electroporation parameter settings on the size of the ablation zone and the occurrence of thermal effects. This insight would help to optimize treatment protocols and effectively ablate a tumor while controlling the occurrence of thermal effects. Methods: Various individual studies report the influence of variation in electroporation parameters on the ablation zone size or occurrence of thermal effects. However, no connections have yet been established between these studies. With the aim of closing the gap in the understanding of and personalizing irreversible electroporation parameter settings, a systematic review was performed according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. A quality assessment was performed using an in-house developed grading tool based on components of commonly used grading domains. Data on the electroporation parameters voltage, number of electrodes, inter-electrode distance, active needle length, pulse length/number/protocol/frequency, and pulse interval were extracted. Ablation zone size and temperature data were grouped per parameter. Spearman correlation and linear regression were used to define the correlation with outcome measures. Results: A total of 7661 articles were screened, of which 18 preclinical studies (animal and phantom studies) met the inclusion criteria. These studies were graded as moderate (4/18) and low (14/18) quality. Only the applied voltage appeared to be a significant linear predictor of ablation zone size: length, surface, and volume. The pulse number was moderately but nonlinearly correlated with the ablation zone length. Thermal effects were more likely to occur for higher voltages (≥2000 V), higher number of electrodes, and increased active needle length. Conclusion: Firm conclusions are limited since studies that investigated and precisely reported the influence of electroporation parameters on the ablation zone size and thermal effects were scarce and mostly graded low quality. High-quality studies are needed to improve the predictability of the combined effect of variation in parameter combinations and optimize irreversible electroporation treatment protocols.

Long-Term Oncological Outcomes After Colorectal Anastomotic Leakage: A Retrospective Dutch Population-based Study.

OBJECTIVE: The aim was to evaluate the impact of anastomotic leak (AL) after colon cancer (CC) and rectal cancer (RC) surgery on 5-year relative survival, disease-free survival (DFS), and disease recurrence. BACKGROUND: AL after CC and RC resection is a severe postoperative complication with conflicting evidence whether it deteriorates long-term outcomes. METHODS: Patients with stage I to IV CC and RC who underwent resection with primary anastomosis were included from the Netherlands Cancer Registry (2008-2018). Relative survival, measured from day of resection, and multivariable relative excess risks (RERs) were analyzed. DFS and recurrence were evaluated in a subset with stage I to III patients operated in 2015. All analyses were performed with patients who survived 90 days postoperatively. RESULTS: A total of 65,299 CC and 22,855 RC patients were included. Five-year relative survival after CC resection with and without AL was 95% versus 100%, 89% versus 94%, 66% versus 76%, and 28% versus 25% for stage I to IV disease. AL was associated with a significantly higher RER for death in stage II and III CC patients. Stage-specific 5-year relative survival in RC patients with and without AL was 97% versus 101%, 90% versus 95%, 74% versus 83%, and 32% versus 41%. AL was associated with a significantly higher RER for death in stage III and IV RC patients. DFS was significantly lower in CC patients with AL, but disease recurrence was not associated with AL after colorectal cancer resection. CONCLUSION: AL has a stage-dependent negative impact on survival in both CC and RC, but no independent association with disease recurrence.

Abdominal wall hernia is a frequent complication of polycystic liver disease and associated with hepatomegaly.

BACKGROUND AND AIM: Polycystic liver disease (PLD) is related to hepatomegaly which causes an increased mechanical pressure on the abdominal wall. This may lead to abdominal wall herniation (AWH). We set out to establish the prevalence of AWH in PLD and explore risk factors. METHODS: In this cross-sectional cohort study, we assessed the presence of AWHs from PLD patients with at least 1 abdominal computed tomography or magnetic resonance imaging scan. AWH presence on imaging was independently evaluated by two researchers. Data on potential risk factors were extracted from clinical files. RESULTS: We included 484 patients of which 40.1% (n = 194) had an AWH. We found a clear predominance of umbilical hernias (25.8%, n = 125) while multiple hernias were present in 6.2% (n = 30). Using multivariate analysis, male sex (odds ratio [OR] 2.727 p < .001), abdominal surgery (OR 2.575, p < .001) and disease severity according to the Gigot classification (Type 3 OR 2.853, p < .001) were identified as risk factors. Height-adjusted total liver volume was an independent PLD-specific risk factor in the subgroup of patients with known total liver volume (OR 1.363, p = .001). Patients with multiple hernias were older (62.1 vs. 55.1, p = .001) and more frequently male (22.0% vs. 50.0%, p = .001). CONCLUSION: AWHs occur frequently in PLD with a predominance of umbilical hernias. Hepatomegaly is a clear disease-specific risk factor.

Adhesion-related readmissions after open and laparoscopic colorectal surgery in 16 524 patients.

AIM: Colorectal surgery is associated with a high risk of adhesion formation and subsequent complications. Laparoscopic colorectal surgery reduces adhesion formation by 50%; however, the effect on adhesion-related complications is still unknown. This study aims to compare differences in incidence rates of adhesion-related readmissions after laparoscopic and open colorectal surgery. METHOD: Population data from the Scottish National Health Service were used to identify patients who underwent colorectal surgery between June 2009 and June 2011. Readmissions were registered until December 2017 and categorized as being either directly or possibly related to adhesions, or as reoperations potentially complicated by adhesions. The primary outcome measure was the difference in incidence of directly adhesion-related readmissions between the open and laparoscopic cohort. RESULTS: Colorectal surgery was performed in 16 524 patients; 4455 (27%) underwent laparoscopic surgery. Patients undergoing laparoscopic surgery were readmitted less frequently for directly adhesion-related complications, 2.4% (95% CI 2.0%-2.8%) versus 7.5% (95% CI 7.1%-7.9%) in the open cohort. Readmissions for possibly adhesion-related complications were less frequent in the laparoscopic cohort, 16.8% (95% CI 15.6%-18.0%) versus 21.7% (95% CI 20.9%-22.5%), as well as reoperations potentially complicated by adhesions, 9.7% (95% CI 8.9%-10.5%) versus 16.9% (95% CI 16.3%-17.5%). CONCLUSION: Overall, any adhesion-related readmissions occurred in over one in three patients after open colorectal surgery and one in four after laparoscopic colorectal surgery. Compared with open surgery, incidence rates of adhesion-related complications decrease but remain substantial after laparoscopic surgery.

Trends in risk factors of anastomotic leakage after colorectal cancer surgery (2011-2019): A Dutch population-based study.

AIM: Anastomotic leakage (AL) after colon cancer (CC) and rectal cancer (RC) surgery often requires reintervention. Prevalence and morbidity may change over time with evolutions in treatment strategies and changes in patient characteristics. This nationwide study aimed to evaluate changes in the incidence, risk factors and mortality from AL during the past nine years. METHODS: Data of CC and RC resections with primary anastomosis were extracted from the Dutch Colorectal Audit (2011-2019). AL was registered if requiring reintervention. Three consecutive cohorts were compared using logistic regression analysis. RESULTS: Incidence of AL after CC surgery decreased from 6.6% in 2011-2013 to 4.8% in 2017-2019 and increased from 8.6% to 11.9% after RC surgery. In 2011-2013, male sex, ASA ≥3, (y)pT3-4, neoadjuvant therapy, emergency surgery and multivisceral resection were identified as risk factors for AL after CC surgery. In 2017-2019, only male sex and ASA ≥3 were risk factors for AL. For RC patients, male sex and neoadjuvant therapy were a risk factor for AL in 2011-2013. In 2017-2019, transanal approach was also a risk factor for AL. Postoperative mortality rate after AL was 12% (CC) and 2% (RC) in 2017-2019, without significant changes over time. CONCLUSION: Contradictory trends in incidence and mortality for AL were observed among CC and RC surgery with changing risk factors over the past 9 years. High mortality after AL is only observed after CC surgery and remains unchanged. Continued efforts should be made to improve early detection and treatment of AL for these patients.

Diagnosis and management of small bowel obstruction in virgin abdomen: a WSES position paper.

BACKGROUND: Small bowel obstruction (SBO) is a common surgical emergency, causing high morbidity and healthcare costs. The majority of SBOs are caused by adhesions that result from previous surgeries. Bowel obstruction, however, also occurs in patients without previous operation or known pathology, a so called virgin abdomen. It is unknown if small bowel obstruction in the virgin abdomen (SBO-VA) can be managed according to the same principles as other cases of small bowel obstruction. The aim of this position paper is to evaluate the available evidence on etiology and management of small bowel obstruction in the virgin abdomen. METHODS: This is a narrative review with scoping aspects. Clinical topics covered in this review include epidemiology and etiology of SBO-VA, diagnosis and imaging, initial assessment, the role of surgical management in SBO-VA, and the role of non-operative management in SBO-VA. RESULTS: Our scoping search revealed seven original studies reporting original patient data related to SBO-VA. All the included studies are retrospective cohorts, with populations ranging between 44 and 103 patients with SBO-VA. Adhesions were found to be the cause of the obstruction in approximately half of the reported cases of SBO-VA. A relatively high number of cases of SBO-VA were managed surgically with studies reporting 39-83%. However, in cases where a trial of non-operative management was started, this was generally successful. CONCLUSION: The data available suggest that etiology and treatment results for patients with SBO-VA are largely comparable to the results in patients with SBO after previous abdominal surgery. We therefore propose that patients with a virgin abdomen could be treated according to existing guidelines for SBO and adhesive small bowel obstruction.

Oncological outcomes of unsuspected pN2 in patients with non-small-cell lung cancer: a systematic review and meta-analysis.

OBJECTIVES: Optimal treatment of stage IIIA (N2) non-small-cell lung cancer (NSCLC) is controversial. Guidelines advise induction therapy before surgical resection. A proportion of patients with cN0 NSCLC are postoperatively upstaged due to unsuspected N2 disease. Survival of unsuspected N2 NSCLC treated with surgery varies and technical feasibility of video-assisted thoracic surgery (VATS) is unknown. The purpose of this study was to assess prevalence and survival of unsuspected N2 NSCLC treated with thoracotomy or VATS. METHODS: A systematic review and meta-analysis was performed of all available literatures through Pubmed, Cochrane, EMBASE, Web of Science, Trials registries and System for Information on Grey Literature (SIGLE) from 2000 to 2019. Outcomes of interest were prevalence, overall survival (OS) and disease-free survival of unsuspected N2 NSCLC. Secondary outcomes were number of harvested lymph nodes, postoperative complications and survival of unsuspected N2 NSCLC treated with VATS. RESULTS: Seventeen studies with patients with clinical stage N0-1 and unsuspected pN2 NSCLC were included. Prevalence of unsuspected pN2 was 8.6%. Three- and 5-year OS was 58% [95% confidence interval (CI) 37-78%) (N = 4337] and 35% (95% CI 28-43%) (N = 4337). Three- and 5-y ear disease-free survival was 48% (95% CI 30-66%) (N = 109) and 35% (95% CI 24-46%) (N = 517). VATS resulted in a low complication rate with similar 5-year OS as thoracotomy. CONCLUSIONS: In patients with cN0-1 NSCLC, a minority has unsuspected pN2 NSCLC. Even for these patients, 5-year OS and disease-free survival are reasonable. VATS with adequate lymph node dissection is the treatment of choice when in experienced hands. Adjuvant therapy should be provided in absence of relevant comorbidity.