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Purpose: Surgical workflow and skill analysis are key technologies for the next generation of cognitive surgical assistance systems. These systems could increase the safety of the operation through context-sensitive warnings and semi-autonomous robotic assistance or improve training of surgeons via data-driven feedback. In surgical workflow analysis up to 91% average precision has been reported for phase recognition on an open data single-center video dataset. In this work we investigated the generalizability of phase recognition algorithms in a multicenter setting including more difficult recognition tasks such as surgical action and surgical skill. Methods: To achieve this goal, a dataset with 33 laparoscopic cholecystectomy videos from three surgical centers with a total operation time of 22 h was created. Labels included framewise annotation of seven surgical phases with 250 phase transitions, 5514 occurences of four surgical actions, 6980 occurences of 21 surgical instruments from seven instrument categories and 495 skill classifications in five skill dimensions. The dataset was used in the 2019 international Endoscopic Vision challenge, sub-challenge for surgical workflow and skill analysis. Here, 12 research teams trained and submitted their machine learning algorithms for recognition of phase, action, instrument and/or skill assessment. Results: F1-scores were achieved for phase recognition between 23.9% and 67.7% (n = 9 teams), for instrument presence detection between 38.5% and 63.8% (n = 8 teams), but for action recognition only between 21.8% and 23.3% (n = 5 teams). The average absolute error for skill assessment was 0.78 (n = 1 team). Conclusion: Surgical workflow and skill analysis are promising technologies to support the surgical team, but there is still room for improvement, as shown by our comparison of machine learning algorithms. This novel HeiChole benchmark can be used for comparable evaluation and validation of future work. In future studies, it is of utmost importance to create more open, high-quality datasets in order to allow the development of artificial intelligence and cognitive robotics in surgery.

Background: Incisional hernia is a frequent complication following loop ileostomy reversal. Incisional hernias are associated with morbidity, loss of health-related quality of life and costs and warrants the investigation of prophylactic measures. Prophylactic mesh implantation at the time of surgical stoma reversal has shown to be a promising and safe method to prevent incisional hernias in this setting. However, the efficacy of this method has not yet been investigated in a large multicentre RCT with adequate external validity. The P.E.L.I.O.N. trial will evaluate the efficacy of prophylactic mesh reinforcement after loop ileostomy closure in decreasing the rate of incisional hernia versus standard closure alone Methods: P.E.L.I.O.N. is a multicentre, prospective, randomized, patient- and observer-blind trial. Patients undergoing loop ileostomy closure will undergo intraoperative 1:1 randomization into either abdominal wall closure with a continuous slowly absorbable suture in small stitch technique without mesh reinforcement (control group) or abdominal wall closure with an additional reinforcement with a retromuscular non-absorbable, macro-pore (pore size ³ 1000 μm or effective porosity >0%) light-weight monofilament or mixed structure mesh. A total of 304 patients (152 per group) will need to be randomised in the study. Based on inclusion and exclusion criteria, 1014 patients are expected to be screened for eligibility in order to recruit the necessary number of patients. Primary endpoint will be the frequency of incisions hernias within 24 months according to the European Hernia Society definition. Secondary endpoints will be the frequency of surgical site occurrences (including surgical site infections, wound seromas and hematomas and enterocutaneous fistulas), postoperative pain, the number of revisions surgeries and health-related quality of life. Safety will be assessed by measuring postoperative complications ≥ grade 3 according to the Dindo-Clavien Classification. Discussion: Depending on the results of the P.E.L.I.O.N. trial prophylactic mesh implantation could become the new standard for loop ileostomy reversal. Trial registration: DRKS00027921, U1111-1273-4657

Purpose Patient-reported outcomes including health-related quality of life (HRQoL) are important oncological outcome measures. The validation of HRQoL instruments for patients with hepatocellular and cholangiocellular carcinoma is lacking. Furthermore, studies comparing different treatment options in respect to HRQoL are sparse. The objective of the systematic review and meta-analysis was, therefore, to identify all available HRQoL tools regarding primary liver cancer, to assess the methodological quality of these HRQoL instruments and to compare surgical, interventional and medical treatments with regard to HRQoL. Methods A systematic literature search was conducted in MEDLINE, the Cochrane library, PsycINFO, CINAHL and EMBASE. The methodological quality of all identified HRQoL instruments was performed according to the COnsensus-based Standards for the selection of health status Measurements INstruments (COSMIN) standard. Consequently, the quality of reporting of HRQoL data was assessed. Finally, wherever possible HRQoL data were extracted and quantitative analyses were performed. Results A total of 124 studies using 29 different HRQoL instruments were identified. After the methodological assessment, only 10 instruments fulfilled the psychometric criteria and could be included in subsequent analyses. However, quality of reporting of HRQoL data was insufficient, precluding meta-analyses for 9 instruments. Conclusion Using a standardized methodological assessment, specific HRQoL instruments are recommended for use in patients with hepatocellular and cholangiocellular carcinoma. HRQoL data of patients undergoing treatment of primary liver cancers are sparse and reporting falls short of published standards. Meaningful comparison of established treatment options with regard to HRQoL was impossible indicating the need for future research.

Background Patients undergoing relaparotomy are generally underrepresented in trials, despite how common the procedure is in clinical practice. The aim of this trial was to determine standard of care and gain evidence of intra- and postoperative outcomes for patients undergoing relaparotomy compared to primary laparotomy. Methods In this single-center controlled clinical trial, adult patients scheduled for elective abdominal surgery via relaparotomy or primary laparotomy were consecutively screened for eligibility. The perioperative course was monitored prospectively in five study visits during hospital stay and one study visit 1 year after surgery. Intraoperative standards, short and long-term outcomes were statistically explored at a level of significance of 5%. Results A total of 131 patients with relaparotomy and 50 patients with primary laparotomy were analyzed. In the relaparotomy group, the access to the abdomen took longer (23.5 min vs. 8.8 min; p = p = p = 0.002). The overall comprehensive complication index and rates of surgical site infection and wound dehiscence with evisceration were not different between the two groups. At long-term follow-up, rates of incisional hernia did not differ (relaparotomy: n = 12/104 (11.5%); primary laparotomy: n = 7/35 (20.0%); p = 0.208). Discussion In this first prospective comparison of relaparotomy with primary laparotomy, inadvertent enterotomies were more frequent in the relaparotomy group. However, contrary to previous retrospective studies, the risk of complications and incisional hernias was not increased compared to primary laparotomy. Trial Registration Deutsches Register Klinischer Studien (www.germanctr.de): DRKS00013001

Interprofessional training wards (IPTW) are a form of interprofessional education enabling trainees of different healthcare professions to work together in teams. Concerns about patient safety are a major barrier to the implementation of IPTWs. The objective of this retrospective study was to analyze patient relevant clinical outcomes on Germany's first IPTW (

Background Delayed gastric emptying (DGE) occurs in up to 40% of patients after esophageal resection and prolongs recovery and hospital stay. Surgically pyloroplasty does not effectively prevent DGE. Recently published methods include injection of botulinum toxin (botox) in the pylorus and mechanical interventions as preoperative endoscopic dilatation of the pylorus. The aim of this study was to investigate the efficacy of those methods with respect to the newly published Consensus definition of DGE. Methods A systematic literature search using CENTRAL, Medline, and Web of Science was performed to identify studies that described pre- or intraoperative botox injection or mechanical stretching methods of the pylorus in patients undergoing esophageal resection. Frequency of DGE, anastomotic leakage rates, and length of hospital stay were analyzed. Outcome data were pooled as odd’s ratio (OR) or mean difference using a random-effects model. Risk of bias was assessed using the Robins-I tool for non-randomized trials. Results Out of 391 articles seven retrospective studies described patients that underwent preventive botulinum toxin injection and four studies described preventive mechanical stretching of the pylorus. DGE was not affected by injection of botox (OR 0.87, 95% confidence interval [CI] 0.37–2.03, P = 0.75), whereas mechanical stretching resulted in significant reduction of DGE (OR 0.26, 95% CI 0.14–0.5, P Conclusion Mechanical stretching of the pylorus, but not injection of botox reduces DGE after esophageal cancer resection. A newly developed consensus definition should be used before the conduction of a large-scale randomized-controlled trial.

Minimally invasive oesophagectomy (MIO) for oesophageal cancer may reduce surgical complications compared with open oesophagectomy. MIO is, however, technically challenging and may impair optimal oncological resection. The aim of the present study was to assess if MIO for cancer is beneficial.A systematic literature search in MEDLINE, Web of Science and CENTRAL was performed and randomized controlled trials (RCTs) comparing MIO with open oesophagectomy were included in a meta-analysis. Survival was analysed using individual patient data. Random-effects model was used for pooled estimates of perioperative effects.Among 3219 articles, six RCTs were identified including 822 patients. Three-year overall survival (56 (95 per cent c.i. 49 to 62) per cent for MIO versus 52 (95 per cent c.i. 44 to 60) per cent for open; P = 0.54) and disease-free survival (54 (95 per cent c.i. 47 to 61) per cent versus 50 (95 per cent c.i. 42 to 58) per cent; P = 0.38) were comparable. Overall complication rate was lower for MIO (odds ratio 0.33 (95 per cent c.i. 0.20 to 0.53); P 0.010) mainly due to fewer pulmonary complications (OR 0.44 (95 per cent c.i. 0.27 to 0.72); P 0.010), including pneumonia (OR 0.41 (95 per cent c.i. 0.22 to 0.77); P 0.010).MIO for cancer is associated with a lower risk of postoperative complications compared with open resection. Overall and disease-free survival are comparable for the two techniques.Oesophagectomy for cancer is associated with a high risk of complications. A minimally invasive approach might be less traumatic, leading to fewer complications and may also improve oncological outcome. A meta-analysis of randomized controlled trials comparing minimally invasive to open oesophagectomy was performed. The analysis showed that the minimally invasive approach led to fewer postoperative complications, in particular, fewer pulmonary complications. Survival after surgery was comparable for the two techniques.Oesophagectomy for cancer is associated with a high risk of complications. A minimally invasive approach might be less traumatic, leading to fewer complications and may also improve oncological outcome. A meta-analysis of randomized controlled trials comparing minimally invasive to open oesophagectomy was performed. The analysis showed that the minimally invasive approach led to fewer postoperative complications, in particular, fewer pulmonary complications. Survival after surgery was comparable for the two techniques.

Physical exercise prehabilitation has been proposed to improve postoperative outcomes in patients undergoing major abdominal surgery. The aim of this systematic review was to investigate the effect of preoperative exercise training compared with standard care on postoperative outcomes in major abdominal surgery. Randomized controlled trials (RCT) comparing prehabilitation with standard care were identified by a systematic literature search of MEDLINE and CENTRAL. Qualitative and quantitative analyses of perioperative outcome data were conducted. Meta-analyses were performed wherever possible and meaningful. A total of eight trials including 442 patients met the inclusion criteria. These trials investigated the effect of prehabilitation in patient cohorts undergoing major liver, colorectal, gastroesophageal, and general abdominal surgery. Quantitative analyses of all included trials showed a significant reduction in postoperative pulmonary complications (OR 0.37; 0.20 to 0.67; p = 0.001) as well as in postoperative overall morbidity (OR 0.52; 0.30 to 0.88; p = 0.01) in the prehabilitation group compared with standard care. The length of hospital stay showed no significant differences between the groups (MD − 0.58; − 1.28 to 0.13; p = 0.11). Risk of bias and methodological quality varied substantially among the trials, most of which were small single-center studies. Prehabilitation including a physical exercise intervention may lead to a reduction of postoperative pulmonary complications as well as less overall morbidity compared with standard care in patients undergoing major abdominal surgery. Further, well-designed RCT are needed to evaluate these potential positive effects in more detail and to identify suitable target populations. PROSPERO 2017 CRD42017080366

Background Surgical resection is the mainstay of potential cure for patients with pancreatic cancer, however, local recurrence is frequent. Previously, we have described an extended resection technique for pancreatoduodenectomy aiming at a radical resection of the nerve and lymphatic tissue between celiac artery, superior mesenteric artery and mesenteric–portal axis (TRIANGLE operation). Until now, data on postoperative outcome have not been reported, yet. Methods Patients who underwent either partial (PD) or total pancreatoduodenectomy (TP) applying the TRIANGLE procedure were identified. These cohorts were compared to matched historic cohorts with standard resections. Results Overall, 330 patients were analysed (PDTRIANGLE and PDSTANDARD, each n = 108; TPTRIANGLE and TPSTANDARD, each n = 57). More lymph nodes were harvested in TRIANGLE compared to standard resection (PD: 27.5 (21–35) versus 31.5 (24–40); P = 0.0187, TP: 33 (28–49) versus 44 (29–53); P = 0.3174) and the rate of tumour positive resections margins, R1(direct), dropped. Duration of operation was significantly longer and blood loss higher. Postoperative mortality and complications did not differ significantly. Conclusion Pancreatoduodenectomy according to the TRIANGLE protocol can be performed without increased morbidity and mortality at a high-volume centre. Long-term survival and quality of life need to be investigated in prospective clinical trials with adequate sample size.

Background Patients undergoing relaparotomy are generally underrepresented in clinical trials, despite how common the procedure is in clinical practice. Specifically, techniques for re-do abdominal wall closure have never been evaluated in a randomised-controlled trial. The aim of this trial was to identify the optimal abdominal wall closure technique in patients undergoing relaparotomy. Methods In this monocentric, randomised feasibility trial, patients scheduled for elective relaparotomy were randomised to abdominal wall closure with either the small stitches technique, using Monomax® 2-0, or the large stitches technique, using PDS II® 1 loop. Patients’ postoperative courses were followed for 1 year after the index operation. Effectiveness and safety outcomes were compared at a level of significance of 5% between the two techniques. Results A total of 100 out of 131 patients (76.3%) were evenly randomised to the small stitches and large stitches groups. The time for abdominal wall closure did not differ between the two techniques (small stitches 27.5 ± 9.5 min versus large stitches 25.3 ± 12.4 min; p = 0.334). The overall comprehensive complication index was 14.4 ± 15.5 in the small stitches group and 19.9 ± 23.4 in the large stitches group (p = 0.168). Specifically, rates of surgical site infection (small stitches 30.0% versus large stitches 36.0%; p = 0.524) and burst abdomen (small stitches 4.0% versus large stitches 0.0%; p = 0.495) did not differ. After 1 year, incisional hernia rate was 7.5% in the small stitches group and 10.0% in the large stitches group (p > 0.999). Discussion Both abdominal wall closure techniques investigated in this trial were feasible in relaparotomy patients. This exploratory trial revealed no noticeable difference in the effectiveness or safety of the small stitches technique with Monomax® 2-0 versus the large stitches technique with PDS II® 1 loop. Therefore, surgeons should stay with their preferred suture technique in relaparotomy patients. Trial registration Deutsches Register Klinischer Studien (www.germanctr.de): DRKS00013001

While several trials have compared laparoscopic to open surgery for colon cancer showing similar oncological results, oncological quality of laparoscopic versus open rectal resection is not well investigated. A systematic literature search for randomized controlled trials was conducted in MEDLINE, the Cochrane Library, and Embase. Qualitative and quantitative meta-analyses of short-term (rate of complete resections, number of harvested lymph nodes, circumferential resection margin positivity) and long-term (recurrence, disease-free and overall survival) oncologic results were conducted. Fourteen randomized controlled trials were identified including 3528 patients. Patients in the open resection group had significantly more complete resections (OR 0.70; 95% CI 0.51–0.97; p = 0.03) and a higher number of resected lymph nodes (mean difference − 0.92; 95% CI − 1.08 to 0.75; p

The optimal surgical approach for adenocarcinoma directly at the esophagogastric junction (AEG II) is still under debate. This study aims to evaluate the differences between right thoracoabdominal esophagectomy (TAE) (Ivor–Lewis operation) and transhiatal extended gastrectomy (THG) for AEG II. From a prospective database, 242 patients with AEG II (TAE, n = 56; THG, n = 186) were included and analyzed according to characteristics and perioperative morbidity and mortality and overall survival (chi-square, Mann–Whitney U, log-rank, Cox regression). Groups were comparable at baseline with exception of age. Patients older than 70 years were more frequently resected by THG (p = 0.003). No differences in perioperative morbidity (p = 0.197) and mortality (p = 0.711) were observed, including anastomotic leakages (p = 0.625) and pulmonary complications (p = 0.494). There was no significant difference in R0 resection (p = 0.719) and number of resected lymph nodes (p = 0.202). Overall median survival was 38.4 months. Survival after TAE was significantly longer than after THG (median OS not reached versus 33.6 months, p = 0.02). Multivariate analysis revealed pN-category (p

Background: Incisional hernias are among the most frequent complications following abdominal surgery and cause substantial morbidity, impaired health-related quality of life and costs. Despite improvements in abdominal wall closure techniques the risk for developing an incisional hernia is reported to be between 10-30% following midline laparotomies. There have been two recent innovations with promising results to reduce hernia risks, namely the small stitches technique and the placement of a prophylactic mesh. So far, these two techniques have not been evaluated in combination. Methods: The HULC trial is a multicentre randomized controlled, observer and patient blinded surgical effectiveness trial with two parallel study groups. A total of 812 patients scheduled for elective abdominal surgery via a midline laparotomy will be randomized in 12 centres after informed consent. Patients will be randomly assigned to the control group receiving closure of the midline incision with a slowly absorbable monofilament suture in small stitches technique or to the intervention group that will receive a small stitches closure followed by augmentation with a light-weight polypropylen mesh in onlay technique. The primary endpoint will be the occurrence of incisional hernias as defined by the European Hernia Society within 24 months after surgery. Further perioperative parameters, as well as patient-reported outcomes, will be analysed as secondary outcomes. Discussion: The HULC trial will address the yet unanswered question whether a combination of small stitched fascial closure and onlay mesh augmentation after elective midline laparotomies reduces the risk of incisional hernias. The HULC trial marks the logical and innovative next step in the development of a safe abdominal closure technique.

Blinding reduces performance and detection bias in randomized controlled trials (RCT). There is evidence that lack of blinding leads to overestimation of treatment effects in pharmacological trials. Since surgical trials use interventions with a physical component, blinding is often complicated. The aim of this study was to analyze, in general and abdominal surgery RCT, the status of blinding, the potential for blinding, and the influence of blinding on outcomes. A systematic search of the literature in CENTRAL, MEDLINE, and Web of Science was conducted to identify RCT with a surgical intervention, starting in 1996, the year when the first CONSORT statement was published. Information on general study characteristics and blinding methods was extracted. The presence or absence of blinding of the study contributors—patients, surgeons, data collectors, outcome assessors, and data analysts—was analyzed. The association of blinding with the trial outcome was investigated for every study contributor. Out of 29,119 articles, 378 RCT were included in the analysis. These investigated a total of 62,522 patients, of whom 15,025 were blinded (24.0%). Contributors could have been blinded in far more trials, as the potential for blinding measures ranged from 69% for outcome assessors to 98% for data analysts. If blinding of surgeons would have been possible but had not been performed, this was associated with more significant trial outcomes (OR 13.670; 95% CI 1.308 to 142.840; p = 0.0289). The potential of blinding, an important quality measure in surgical RCT, has not been exhausted. This study summarizes the existing evidence on blinding in surgical trials and gives evidence-based recommendations for the use of blinding in future surgical trials. PROSPERO 2015:CRD42015026837.

Die klinische Forschung in der Chirurgie lasst sich nach der Definition der Deutschen Forschungsgemeinschaft in 3 Bereiche gliedern: grundlagen-, krankheits- und patientenorientierte Forschung 1 , 2 . Als Methoden werden klinische Studien aller Phasen sowie Studientypen der klinischen Epidemiologie angesehen. Neue operative Verfahren werden bis heute oft nicht uber einen wissenschaftlich belegbaren Weg in die Krankenversorgung eingefuhrt. Daher mussen vermehrt klinische Studien nach entsprechenden internationalen Standards durchgefuhrt werden, um fundierte, objektive Aussagen uber Effekt, Wirksamkeit und Risiken eines neuen chirurgischen Verfahrens machen zu konnen. Hierzu sind in der Chirurgie, wie auch in anderen medizinischen Fachbereichen, spezielle methodische Kenntnisse zur Planung, Durchfuhrung und Auswertung klinischer Studien zwingende Voraussetzung. Uber diese methodischen Grundlagen soll der folgende Artikel einen Uberblick geben.

Hintergrund Zu den haufigsten Komplikationen nach abdominalchirurgischen Eingriffen mittels Laparotomie gehoren Narbenhernien und Wundinfektionen, welche in mehr als 10–15 % der Falle auftreten. Das Risiko dieser Komplikationen lasst sich durch chirurgische Technik und die Verwendung von speziellem Nahtmaterial jedoch reduzieren. Im Jahr 2010 ergab die INLINE-Metaanalyse des Studienzentrums der Deutschen Gesellschaft fur Chirurgie (SDGC), dass eine fortlaufende Nahttechnik mit einem langsam resorbierbaren Nahtmaterial die besten Ergebnisse nach elektiver medianer Laparotomie in Bezug auf das Narbenhernienrisiko zeigt.

Introduction Esophageal foreign bodies are an important and serious cause of morbidity and mortality in both children and adults. Due to the possibility of serious complications, i.e. perforation, necrosis, mediastinitis, and fistulation, rapid and accurate diagnostic measures with subsequent therapy are necessary. Case report We are reporting a case of a 55-year-old, mentally impaired patient that has swallowed a foreign body, which subsequently became lodged in his esophagus. Due to the fact that endoscopic removal was not possible and there was a high risk of complications such as esophageal perforation or mediastinitis in this case, we performed cervical esophagotomy and successfully extracted the foreign body. The patient showed an uneventful postoperative process and could be discharged on Day 11 after the operation. Comprehensive review Furthermore, we performed a systematic review of the literature to identify all studies that described a surgical approach through esophagotomy in cases of foreign body ingestion and found 11 publications describing the cases of 29 patients. These studies reported an overall complication rate of 17.2% and a mortality rate of 0%. Conclusion Our findings suggest that esophagotomy could be a viable approach for the extraction of foreign bodies especially in some cases when endoscopic removal was not successful and the risk of esophageal perforation is high., Highlights • A case of cervical esophagotomy for foreign body extraction is described. • Systematic review of literature shows 29 patients undergoing esophagotomy. • Complication rates after esophagotomy are justifiable. • Cervical esophagotomy is a feasible surgical approach. • A clinical management guideline is provided.

The aim of this systematic review and meta-analysis was to compare the oncological and perioperative outcomes of transhiatally extended gastrectomy (TEG) and thoracoabdominal esophagectomy (TAE) for therapy of adenocarcinomas of the esophagogastric junction (AEG) with focus on AEG type II, as the optimal approach for these tumors is still unclear. MEDLINE, EMBASE, and the Cochrane Library (CENTRAL) were searched until July 24, 2018. Studies comparing TAE and TEG for surgical treatment of AEG type tumors have been included. Patient’s baseline and perioperative data have been extracted and meta-analyses have been conducted for the outcomes: number of dissected lymph nodes, R0-resection rate, anastomotic leak rate, postoperative morbidity, and 30-day mortality. Of 6709 articles identified, 8 studies have been included for further analysis. One thousand thirty-four patients underwent TAE, and 1177 patients TEG. No differences were found between the approaches in regard to number of dissected lymph nodes (MD − 0.96; 95% CI − 3.07 to 1.15; p = 0.37), R0-resection rates (OR 0.97; 95% CI 0.57 to 1.63; p = 0.90), anastomotic leak rates (OR 1.13; 95% CI 0.69 to 1.86; p = 0.63), and 30-day mortality (OR 1.53; 95% CI 0.90 to 2.61; p = 0.11). However, a higher rate of postoperative morbidity was found after TAE (OR 1.55; 95% CI 1.12 to 2.14; p = 0.008). The optimal approach to surgical therapy of AEG II still remains unclear. This study identified a significantly higher rate of postoperative morbidity after TAE at comparable surgical outcomes. Due to major limitations concerning the quality of included studies, current data strongly mandates a properly designed randomized controlled trial to identify the optimal surgical approach for AEG type II tumors.

Summary Lymphocele formation after kidney transplantation is a frequent complication which causes pain, secondary graft loss, rehospitalizations and reoperations. Therefore, prophylaxis of lymphocele formation is of utmost importance. To assess the effectiveness of peritoneal fenestration in renal transplantation to prevent lymphocele development. A systematic literature search was conducted combined with hand-searches on lymphocele prevention following renal transplantation using peritoneal fenestration. A qualitative and quantitative analysis of included trials was conducted. We identified three trials including 414 patients and 437 transplantations which studied peritoneal fenestration. Only one randomized controlled trial was identified. Critical appraisal uncovered a number of methodological flaws, predominantly in the nonrandomized studies. Most importantly endpoint definitions varied among trials, selection bias was high and interventions and follow-up were not standardized. Meta-analysis of the included trials showed a significant reduction of clinically symptomatic lymphoceles (OR: 0.23, 95% CI: 0.09–0.64, P = 0.005) and overall postoperative fluid collections (OR: 0.49, 95% CI: 0.28–0.88, P = 0.02) without a significant increase in other surgical complications. Although peritoneal fenestration is a promising technique to reduce lymphocele formation, only few studies have investigated this technique so far. Given the low methodological quality of included trials, more studies are necessary to evaluate the effectiveness and the risks and benefits of this technique.

Adrenalectomy can be performed via open and various minimally invasive approaches. The aim of this systematic review was to summarize the current evidence on surgical techniques of adrenalectomy. Systematic literature searches (MEDLINE, EMBASE, Web of Science, Cochrane Library) were conducted to identify randomized controlled trials (RCTs) and controlled clinical trials (CCTs) comparing at least two surgical procedures for adrenalectomy. Statistical analyses were performed, and meta-analyses were conducted. Furthermore, an indirect comparison of RCTs and a network meta-analysis of CCTs were carried out for each outcome. Twenty-six trials (1710 patients) were included. Postoperative complication rates did not show differences for open and minimally invasive techniques. Operation time was significantly shorter for open adrenalectomy than for the robotic approach (p

Anastomotic leakage is one of the most severe complications following esophageal resection. Among other strategies, gastric ischemic preconditioning has been proposed to improve anastomotic integrity. The aim of this systematic review is to investigate whether gastric preconditioning has influence on peri- or postoperative outcomes after esophageal resection. A systematic literature search was performed to identify studies comparing gastric preconditioning with non-preconditioned patients for any indication of esophageal resection. Random-effects meta-analyses were conducted for main outcomes. Gastric preconditioning did not reduce anastomotic leakages (OR 0.76; 95%-CI 0.51 to 1.13; p = 0.18), anastomotic strictures (OR 1.10; 95%-CI 0.58 to 2.10; p = 0.76;), major complications (OR 1.14; 95%-CI 0.60 to 2.14; p = 0.69), or in-hospital mortality (OR 0.62; 95%-CI 0.28 to 1.40; p = 0.25). However, preconditioning reduced the rate of severe leaks requiring reoperation (OR 0.20; 95%-CI 0.08 to 0.53; p = 0.001). Increasing the period between preconditioning and esophageal resection over 2 weeks did not reduce anastomotic leakage compared to shorter waiting times (OR 0.65; 95%-CI 0.38 to 1.13; p = 0.13). With current evidence, gastric preconditioning does not seem to reduce overall rates of anastomotic leakage after esophageal resection but seems to reduce severity of leakages.

Background Blinding is a measure in randomized controlled trials (RCT) to reduce detection and performance bias. There is evidence that lack of blinding leads to overestimated treatment effects. Because of the physical component of interventions, blinding is not easily applicable in surgical trials. This is a protocol for a systematic review and empirical study about actual impact on outcomes and future potential of blinding in general and abdominal surgery RCT. Methods/design A systematic literature search in CENTRAL, MEDLINE and Web of Science will be conducted to locate RCT between 1996 and 2015 with a surgical intervention. General study characteristics and information on blinding methods will be extracted. The risk of performance and detection bias will be rated as low, unclear or high according to the Cochrane Collaboration’s tool for assessing risk of bias. The main outcome of interest will be the association of a high risk of performance or detection bias with significant trial results and will be tested at a level of significance of 5 %. Further, trials will be meta-analysed in a Mantel-Haenszel model comparing trials with high risk of bias to other trials at a level of significance of 5 %. Discussion Detection and performance bias distort treatment effects. The degree of such bias in general and abdominal surgery is unknown. Evidence on influence of missing blinding would improve critical appraisal and conduct of general and abdominal surgery RCT. Systematic review registration PROSPERO 2015:CRD42015026837. Electronic supplementary material The online version of this article (doi:10.1186/s13643-016-0226-4) contains supplementary material, which is available to authorized users.