The Role of Biologic Mesh and Fundoplication in the Surgical Management of Hiatal Hernias: A Multicenter Evaluation.

INTRODUCTION: Hiatal hernia repair is associated with substantial recurrence of both hiatal hernia and symptoms of gastroesophageal reflux (GER). While small randomized controlled trials demonstrate limited differences in outcomes with use of mesh or fundoplication type, uncertainty remains. METHODS: A multicenter, retrospective review of patients undergoing surgical treatment of hiatal hernias between 2015 and 2020 was performed. Patients with mesh and with suture-only repair were compared, and partial versus complete fundoplication was compared. Primary outcomes were hernia recurrence and occurrence of postoperative GER symptoms and dysphagia. Multivariable regression was performed to assess the effect of each intervention on clinical outcomes. RESULTS: A total of 453 patients from four sites were followed for a median (IQR) of 17 (13) months. On multivariate analysis, mesh had no impact on hernia recurrence (odds ratio 0.993, 95% CI: 0.53-1.87, p = 0.982), and fundoplication type did not impact recurrence of postoperative GER symptoms (complete: odds ratio 0.607, 95% CI: 0.33-1.12, p = 0.112) or dysphagia (complete: odds ratio 1.17, 95% CI: 0.56-2.43, p = 0.677). CONCLUSION: During hiatal hernia repair, mesh and fundoplication type do not appear to have substantial impact on GER symptoms, dysphagia, or hernia recurrence. This multicenter study provides real-world evidence to support the findings of small RCTs.

Hernia Prevention Using Biologic Mesh and/or Small Bites: A Multispecialty 2 × 2 Factorial Randomized Controlled Trial.

BACKGROUND: Ventral incisional hernias are the most common complication after abdominal operation. Randomized trials have shown efficacy of prophylactic synthetic mesh and small bites. Adoption of these practices has been limited due to concerns with placement of synthetic mesh in contaminated cases and small bites in an overweight population. We sought to assess the efficacy of prophylactic biologic mesh and small bites to prevent postoperative major complications: ventral incisional hernias, surgical site infection, reoperation, and death. STUDY DESIGN: High-risk patients (overweight/obese, current smoker) undergoing abdominal operation with a midline incision (5 cm or greater) were randomized (2 × 2 factorial trial) to receive either sublay biologic mesh or no mesh and either small bites (0.5 × 0. 5cm) or large bites (1 × 1 cm) fascial closure. The primary outcome measure was major complications at 1 year postoperative. CONSORT guidelines were followed, and this study was registered on clinicaltrials.gov (NCT03148496). Assuming α = 0.05, ß = 0.20, and Δ = 20%, it was estimated that 105 patients were needed. Primary outcome was assessed using Fisher's exact test. RESULTS: A total of 107 patients were randomized: 52 (49%) to mesh, 55 (51%) to no mesh, 55 (51%) to small bites, and 52 (49%) to large bites. Of the patients, 16% were smokers, 31% were overweight, and 55% were obese. At 1 year postoperative, there were no differences in major complications between groups (mesh vs no mesh 21% vs 16%, p = 0.62; small vs large bites 18% vs 19%, p = 1.00). CONCLUSIONS: In this trial, biologic mesh and small bites appear to have no benefit. Further randomized trials are needed among high-risk patients before widespread adoption of prophylactic biologic mesh or small bites.

Biologic Versus Synthetic Mesh in Ventral Hernia Repair: Participant-Level Analysis of Two Randomized Controlled Trials at Twenty-Four to Thirty-Six Months.

Background: Biologic mesh has been used increasingly in complex ventral hernia repair despite limited evidence at low risk of bias supporting its use. Patients and Methods: We performed a participant-level analysis of published randomized controlled trials (RCTs) comparing biologic to synthetic mesh with complex ventral hernia repair at 24 to 36 months. Primary outcome was major complication (composite of mesh infection, recurrence, reoperation, or death) at 24 to 36 months post-operative. Secondary outcomes included length of index hospital stay, surgical site occurrence, surgical site infection, and death. Outcomes were assessed using both frequentist and Bayesian generalized linear regression models. Results: A total of 252 patients from two RCTs were included, 126 patients randomized to the intervention arm of biologic and 126 patients to the control of synthetic mesh with median follow-up of 29 (23, 38) months. Major complication occurred in 33 (33%) patients randomized to biologic, and 39 (38%) patients randomized to synthetic mesh, (relative risk [RR] 0.91, 95% confidence interval [CI] 0.63-1.31; p value = 0.600). Bayesian analysis demonstrated that compared with synthetic mesh, biologic mesh had similar probability of major complications at 24 to 36 months post-operative. The remainder of outcomes demonstrated slight benefit with synthetic mesh as opposed to biologic mesh except for mesh infection. However, under a frequentist framework, no outcome was statistically different. Conclusions: In patients undergoing open ventral hernia repair, there was no benefit for patients receiving biologic versus synthetic mesh at 24 to 36 months post-operative.

Robotic Versus Laparoscopic Ventral Hernia Repair: Two-Year Results From a Prospective, Multicenter, Blinded Randomized Clinical Trial.

OBJECTIVE: Report the 2-year outcomes of a multicenter randomized controlled trial comparing robotic versus laparoscopic intraperitoneal onlay mesh ventral hernia repair. BACKGROUND: Ventral hernia repair is one of the most common operations performed by general surgeons. To our knowledge, no studies have been published to date comparing long-term outcomes of laparoscopic versus robotic ventral hernia repair. METHODS: The trial was registered at clinicaltrials.gov (NCT03490266). Clinical outcomes included surgical site infection, surgical site occurrence, hernia occurrence, readmission, reoperation, and mortality. RESULTS: A total of 175 consecutive patients were approached that were deemed eligible for elective minimally invasive ventral hernia repair. In all, 124 were randomized and 101 completed follow-up at 2 years. Two-year follow-up was completed in 54 patients (83%) in the robotic arm and 47 patients (80%) in the laparoscopic arm. No differences were seen in surgical site infection or surgical site occurrence. Hernia recurrence occurred in 2 patients (4%) receiving robotic repair versus in 6 patients (13%) receiving laparoscopic repair (relative risk: 0.3, 95% CI: 0.06-1.39; P =0.12). No patients (0%) required reoperation in the robotic arm whereas 5 patients (11%) underwent reoperation in the laparoscopic arm ( P =0.019, relative risk not calculatable due to null outcome). CONCLUSIONS: Robotic ventral hernia repair demonstrated at least similar if not improved outcomes at 2 years compared with laparoscopy. There is potential benefit with robotic repair; however, additional multi-center trials and longer follow-up are needed to validate the hypothesis-generating findings of this study.

Evaluation of ICARUS Guidelines and Recommendations Not Supported by Randomized Controlled Trials.

BACKGROUND: The ICARUS guidelines are a systematic review and Delphi process that provide recommendations in the treatment and management of patients with gastroesophageal reflux disease (GERD). Many of the recommendations were supported by randomized trials; some were not. This study assesses guidelines with limited evidence and weak endorsement. METHODS: Four ICARUS guidelines were chosen: the role of fundoplication for patients with BMI > 35, regurgitation, chest pain, and extra-esophageal symptoms. A multicenter database of patients undergoing fundoplication surgery for GERD between 2015 and 2020 was used. Outcomes assessed were anatomic failure and symptom recurrence. Multivariable regression was performed. RESULTS: Five institutions performed a fundoplication on 461 patients for GERD with a median of follow-up of 14.7 months (IQR 14.2). On multivariate analysis, patients with the chosen pre-operative comorbidities achieved comparable post-operative benefits. Patients with a BMI > 35 were not more likely to experience anatomic failure. Patients with pre-operative regurgitation had similar symptom recurrence rates to those without. Patients with non-cardiac chest pain had comparable rates of symptom recurrence to those without. Reporting a pre-operative chronic cough attributable to reflux was not associated with higher rates of post-operative symptom recurrence. DISCUSSION: Among the ICARUS guidelines and recommendations, a small proportion was lacking evidence at low risk for bias and endorsement. The results of this multicenter study evaluated outcomes of patients with various pre-operative conditions: BMI > 35, chest pain attributable to reflux, extra-esophageal symptoms attributable to reflux, and regurgitation. Our findings endorse patients with these characteristics as candidates for anti-reflux surgery.

Systematic Review of Treatment of Patients with Achalasia: Heller Myotomy, Pneumatic Dilation, and Peroral Endoscopic Myotomy.

BACKGROUND: The aim of this systematic review is to assess all comparative randomized controlled trials evaluating Heller myotomy, pneumatic dilation, and peroral endoscopic myotomy. STUDY DESIGN: Achalasia is an esophageal motility disorder associated with degeneration of the myenteric plexus; it causes significant symptoms and impacts patient quality of life (QOL). The optimal treatment for patients with achalasia and the impact of these interventions on QOL remain unclear. PubMed, Embase, Scopus, and Cochrane were searched from inception to April 2020. Randomized controlled trials that compared the 3 interventions were included. Primary outcome was QOL at 12 to 36 months after the operation. Secondary outcomes included reintervention, dysphagia, leak/perforation, and GERD recurrence. RESULTS: Nine publications of 6 studies were included. Of the 9 publications, there was no significant difference in QOL at 12 to 36 months except for one study in which QOL was significantly higher in patients who underwent Heller myotomy as opposed to pneumatic dilation at 3 years; however, at 5 years there was no difference. Pneumatic dilation was associated with the highest rates of dysphagia recurrence and reintervention, but peroral endoscopic myotomy had the lowest. CONCLUSIONS: The treatment of achalasia should be chosen in accordance with patient goals. After any of the 3 interventions, QOL appears to be similar. However, peroral endoscopic myotomy may be associated with the lowest rates of perforation/leak, dysphagia, and reintervention and may be the lowest risk option. However, there are barriers to widespread use due to challenges in training and adoption.

Safety and Feasibility of Performing Antireflux Procedures at a Safety Net Hospital.

INTRODUCTION: One-half of Americans have limited access to health care; these patients often receive care through safety net hospitals, which are associated with worse medical outcomes. This study aims to compare the outcomes of patients who received foregut surgery at a safety net hospital to those at a private or university hospital. We hypothesized that patients treated at the safety net hospital will have a greater rate of radiographic recurrence and reoperations. METHODS: A retrospective study was conducted on patients who underwent hiatal hernia repair or fundoplication for gastroesophageal reflux disease at an affiliated safety net, private, or university hospital from June 2015 to May 2020. The primary outcome was radiographic recurrence. The secondary outcomes included reoperation and symptom recurrence. Analysis was performed using analysis of variance, chi-square, and logistic regression. RESULTS: A total of 499 patients were identified: 157 at a safety net hospital, 233 at a private hospital, and 119 at a university hospital. The median (interquartile range) follow-up was 16 (13) mo. The safety net hospital treated more Hispanics, females, and patients with comorbidities. Large hiatal hernias were more common at the safety net and private hospitals. Robotic surgery was more frequently at the university hospital. There was no difference in radiographic recurrence (13.4% versus 19.7% versus 17.6%; P = 0.269), reoperation (3.8% versus 7.2% versus 6.7%; P = 0.389), or postoperative dysphagia (15.3% versus 12.6% versus 15.1%; P = 0.696). On logistic regression, there were no differences in outcomes among institutions. CONCLUSIONS: This study suggests that despite the challenges faced at safety net hospitals, it could be feasible to safely perform minimally invasive foregut surgery with similar outcomes to private and university hospitals.

Prophylactic Mesh Reinforcement for Prevention of Midline Incisional Hernias: A Publication Bias Adjusted Meta-analysis.

OBJECTIVE: To systematically review the published literature on the use of prophylactic mesh reinforcement of midline laparotomy closures for prevention of VIH. SUMMARY OF BACKGROUND DATA: VIH are common complications of abdominal surgery. Prophylactic mesh has been proposed as an adjunct to prevent their occurrence. METHODS: PubMed, Embase, Scopus, and Cochrane were reviewed for RCTs that compared prophylactic mesh reinforcement versus conventional suture closure of midline abdominal surgery. Primary outcome was the incidence of VIH at postoperative follow-up ≥24 months. Secondary outcomes included surgical site infection and surgical site occurrence (SSO). Pooled risk ratios were obtained through random effect meta-analyses and adjusted for publication bias. Network meta-analyses were performed to compare mesh types and locations. RESULTS: Of 1969 screened articles, 12 RCTs were included. On meta-analysis there was a lower incidence of VIH with prophylactic mesh [11.1% vs 21.3%, Relative risk (RR) = 0.32; 95% confidence interval (CI) = 0.19-0.55, P < 0.001), however, publication bias was highly likely. When adjusted for this bias, prophylactic mesh had a more conservative effect (RR = 0.52; 95% CI = 0.39-0.70). There was no difference in risk of surgical site infection (9.1% vs 8.9%, RR = 1.08, 95% CI = 0.82-1.43; P = 0.118), however, prophylactic mesh increased the risk of SSO (14.2% vs 8.9%, RR = 1.57, 95% CI = 1.19-2.05; P < 0.001). CONCLUSION: Current RCTs suggest that in mid-term follow-up prophylactic mesh prevents VIH with increased risk for SSO. There is limited long-term data and substantial publication bias.

Expert Consensus for Key Features of Operative Reports of Ventral Hernia.

BACKGROUND: Operative reports are important documents; however, standards for critical elements of operative reports are general and often vague. Hernia surgery is one of the most common procedures performed by general surgeons, so the aim of this project was to develop a Delphi consensus on critical elements of a ventral hernia repair operative report. STUDY DESIGN: The Delphi method was used to establish consensus on key features of operative reports for ventral hernia repair. An expert panel was selected and questionnaires were distributed. The first round of voting was open-ended to allow participants to recommend what details should be included. For the second round the questionnaire was distributed with the items that did not have unanimous responses along with free text comments from the first round. RESULTS: Eighteen surgeons were approached, of which 11 completed both rounds. Twenty items were on the initial questionnaire, of which 11 had 100% agreement. Of the remaining 9 items, after the second questionnaire an additional 7 reached consensus. CONCLUSION: Ventral hernia repairs are a common and challenging problem and often require reoperations. Surgeons frequently refer to previous operative notes to guide future procedures, which requires detailed and comprehensive operative reports. This Delphi consensus was able to identify key components needed for an operative report describing ventral hernia repair.

Reproducing Statistics Performed in Published Randomized Controlled Trials.

INTRODUCTION: Randomized controlled trials (RCT) represent evidence at the lowest potential risk for bias. Clinicians in all specialties depend upon RCTs to guide patient care. Issues such as statistical discordance, or reporting statistical results that cannot be reproduced, should be uncommon. Our aim was to confirm the statistical reproducibility of published RCTs. METHODS: PubMed was searched using "randomized controlled trial." Studies were selected using a random number generator. Studies were included if the primary outcome could be reproduced using the data and statistical test reported in the manuscript. The reproduced p-value from our analysis and the published p-value were compared. Primary outcome was the number of studies that reported p-values that differed in statistical significance (crossed p-value=0.05) from the reproduction analysis. Assuming an alpha of 0.05, a beta of 0.80, an estimated rate of statistical discordance of 5% for RCTs, a total of at least 568 studies were required. RESULTS: Overall, 572 RCTs were selected involving six specialties. Of these, 45% were positive (p<0.05) studies. Eleven (2%) published results that differed from the reproduction analysis and crossed the p=0.05 threshold. All 11 studies were positive studies (while the reproduction analysis demonstrated p≥0.05). CONCLUSION: Less than 5% of published RCTs reported a discordant p-value that crossed the "p=0.05" threshold. Although the occurrence is uncommon, the existence of even one RCT publishing nonreproducible results is concerning. Future studies should seek to identify why some RCTs report discordant statistics and how to prevent this from occurring.

Self-selection vs Randomized Assignment of Treatment for Appendicitis.

Importance: For adults with appendicitis, several randomized clinical trials have demonstrated that antibiotics are an effective alternative to appendectomy. However, it remains unknown how the characteristics of patients in such trials compare with those of patients who select their treatment and whether outcomes differ. Objective: To compare participants in the Comparison of Outcomes of Antibiotic Drugs and Appendectomy (CODA) randomized clinical trial (RCT) with a parallel cohort study of participants who declined randomization and self-selected treatment. Design, Setting, and Participants: The CODA trial was conducted in 25 US medical centers. Participants were enrolled between May 3, 2016, and February 5, 2020; all participants were eligible for at least 1 year of follow-up, with all follow-up ending in 2021. The randomized cohort included 1094 adults with appendicitis; the self-selection cohort included patients who declined participation in the randomized group, of whom 253 selected appendectomy and 257 selected antibiotics. In this secondary analysis, characteristics and outcomes in both self-selection and randomized cohorts are described with an exploratory analysis of cohort status and receipt of appendectomy. Interventions: Appendectomy vs antibiotics. Main Outcomes and Measures: Characteristics among participants randomized to either appendectomy or antibiotics were compared with those of participants who selected their own treatment. Results: Clinical characteristics were similar across the self-selection cohort (510 patients; mean age, 35.8 years [95% CI, 34.5-37.1]; 218 female [43%; 95% CI, 39%-47%]) and the randomized group (1094 patients; mean age, 38.2 years [95% CI, 37.4-39.0]; 386 female [35%; 95% CI, 33%-38%]). Compared with the randomized group, those in the self-selection cohort were less often Spanish speaking (n = 99 [19%; 95% CI, 16%-23%] vs n = 336 [31%; 95% CI, 28%-34%]), reported more formal education (some college or more, n = 355 [72%; 95% CI, 68%-76%] vs n = 674 [63%; 95% CI, 60%-65%]), and more often had commercial insurance (n = 259 [53%; 95% CI, 48%-57%] vs n = 486 [45%; 95% CI, 42%-48%]). Most outcomes were similar between the self-selection and randomized cohorts. The number of patients undergoing appendectomy by 30 days was 38 (15.3%; 95% CI, 10.7%-19.7%) among those selecting antibiotics and 155 (19.2%; 95% CI, 15.9%-22.5%) in those who were randomized to antibiotics (difference, 3.9%; 95% CI, -1.7% to 9.5%). Differences in the rate of appendectomy were primarily observed in the non-appendicolith subgroup. Conclusions and Relevance: This secondary analysis of the CODA RCT found substantially similar outcomes across the randomized and self-selection cohorts, suggesting that the randomized trial results are generalizable to the community at large. Trial Registration: ClinicalTrials.gov Identifier: NCT02800785.

Review of SAGES GERD guidelines and recommendations.

BACKGROUND: The Society of American Gastrointestinal and Endoscopic Surgeons (SAGES) developed evidence-based guidelines for the management of patients with gastroesophageal reflux disease (GERD). The aim of this study is to evaluate guidelines lacking agreement among experts (grades B-D) or lacking support from randomized controlled trials (levels II-III). METHODS: Six guidelines were chosen for evaluation. A retrospective review of a multicenter database of patients undergoing fundoplication surgery for treatment of GERD between 2015 and 2020 was performed. Patients that underwent a concurrent gastrectomy or were diagnosed with pre-operative achalasia were excluded. Demographics, pre-operative, intra-operative, and post-operative variables were collected. Post-operative outcomes were evaluated based on selected SAGES guidelines. Outcomes were assessed using multivariable regression or stratified analysis for each guideline. RESULTS: A total of 444 patients from four institutions underwent surgery for the management of GERD with a median (interquartile range) follow-up of 16 (13) months. Guidelines supported by our data were (1) robotic repair has similar short-term outcomes to laparoscopic repair, (2) outcomes in older patients are similar to outcomes of younger patients undergoing antireflux surgery, and (3) following laparoscopic antireflux surgery, dysphagia has been reported to significantly improve from pre-operative values. Guidelines that were not supported were (1) mesh reinforcement may be beneficial in decreasing the incidence of wrap herniation, (2) a bougie has been found to be effective, and (3) the long-term effectiveness of fundoplication in obese individuals (BMI > 30) has been questioned due to higher failure rates. CONCLUSION: Many SAGES GERD guidelines not receiving Grade A or Level I recommendation are supported by large, multicenter database findings. However, further studies at low risk for bias are needed to further refine these guidelines.

Is expectant management warranted in patients with ventral hernias and co-morbidities? A prospective, 5 year follow-up, patient-centered study.

BACKGROUND: Our aim was to report the natural history of operative versus expectant management of patients with ventral hernias and co-morbidities at five years. METHODS: This was a prospective observational study. Patients were managed with elective repair or expectantly, based on co-morbidities and patient/surgeon choice. Primary outcome was functional status. Patients were matched using optimal matching. Outcomes were compared using multivariable regression. RESULTS: A total of 197 patients were included (78 operative, 119 expectant) with median follow-up of 5.1 (3.2-5.5) years. In the matched-cohort (n = 80), 58 vs 68% were obese, and 88% vs 95% had a major comorbidity. Both groups had similar baseline functional status (p = 0.788), but only those repaired initially had significantly improved scores at five years (p < 0.050). Half (20) of patients managed expectantly crossed over to repair, and 15% (3) were emergent/urgent. CONCLUSION: Initial repair improves long-term functional status significantly compared to expectant management. Repair by hernia experts should be considered for high-risk patients.

Randomized controlled trials published on patients with hernias have a high percentage of unreproducible statistics.

INTRODUCTION: Surgeons rely on randomized controlled trials (RCT) to compare the effectiveness of treatments. RCTs require careful planning and substantial effort to complete. Because of the careful study design, statistics performed are often easy to reproduce such as Chi-squared or t-test. Issues such as statistical discordance, or reporting statistical results that cannot be reproduced, should be uncommon. METHODS: RCTs pertaining to hernias were identified in PubMed using the search terms "hernia" and "randomized controlled trial." Studies were selected using a random number generator. Studies were included if the primary outcome could be reproduced using the data and statistical test reported in the manuscript. Discordance between the obtained p-value from our analysis and the published p-value was assessed. Primary outcome was the number of studies that reported p-values that crossed the level of statistical significance (p-value = 0.05) but on reproduction analysis did not. RESULTS: Of the 100 included RCTs, five reported p-values that crossed the "p = 0.05" threshold that our team was unable to reproduce using the statistical test reported in the manuscript. An additional three studies reported p-values that crossed the "p = 0.05" threshold that our team was unable to reproduce using the appropriate statistical test (i.e., Fisher's exact test when all expected cell counts < 5). All eight studies published p-values < 0.05, whereas, our re-analysis demonstrated p ≥ 0.05. CONCLUSION: Eight percent of the RCTs analyzed in this study reported p-values < 0.05 that on reproduction analysis was ≥ 0.05. The next steps should be to determine reasons for discordance and how to prevent this from happening.

Two-year Outcomes of Prehabilitation Among Obese Patients With Ventral Hernias: A Randomized Controlled Trial (NCT02365194).

OBJECTIVE: To determine if preoperative nutritional counseling and exercise (prehabilitation) improve outcomes in obese patients seeking ventral hernia repair (VHR)? SUMMARY BACKGROUND DATA: Obesity and poor fitness are associated with complications following VHR. It is unknown if preoperative prehabilitation improves outcomes of obese patients seeking VHR. METHODS: This is the 2-year follow-up of a blinded randomized controlled trial from 2015 to 2017 at a safety-net academic institution. Obese patients (BMI 30-40) seeking VHR were randomized to prehabilitation versus standard counseling. Elective VHR was performed once preoperative requirements were met: 7% total body weight loss or 6 months of counseling and no weight gain. Primary outcome was percentage of hernia-free and complication-free patients at 2 years. Complications included recurrence, reoperation, and mesh complications. Primary outcome was compared using chi-square. We hypothesize that prehabilitation in obese patients with VHR results in more hernia- and complication-free patients at 2-years. RESULTS: Of the 118 randomized patients, 108 (91.5%) completed a median (range) follow-up of 27.3 (6.2-37.4) months. Baseline BMI (mean±SD) was similar between groups (36.8 ±â€Š2.6 vs 37.0 ±â€Š2.6). More patients in the prehabilitation group underwent emergency surgery (5 vs 1) or dropped out of the program (3 vs 1) compared to standard counseling (13.6% vs 3.4%, P = 0.094). Among patients who underwent surgery, there was no difference in major complications (10.2% vs 9.1%, P = 0.438). At 2-years, there was no difference in percentage of hernia-free and complication-free patients (72.9% vs 66.1%, P = 0.424, 1.14, 0.88-1.47). CONCLUSION: There is no difference in 2-year outcomes of obese patients seeking VHR who undergo prehabilitation versus standard care. Prehabilitation may not be warranted in obese patients undergoing elective VHR.Clinical Trial Registration: This trial was registered with clinicaltrials.gov (NCT02365194).

The Evidence Behind Robot-Assisted Abdominopelvic Surgery : A Systematic Review.

BACKGROUND: Use of robot-assisted surgery has increased dramatically since its advent in the 1980s, and nearly all surgical subspecialties have adopted it. However, whether it has advantages compared with laparoscopy or open surgery is unknown. PURPOSE: To assess the quality of evidence and outcomes of robot-assisted surgery compared with laparoscopy and open surgery in adults. DATA SOURCES: PubMed, EMBASE, Scopus, and the Cochrane Central Register of Controlled Trials were searched from inception to April 2021. STUDY SELECTION: Randomized controlled trials that compared robot-assisted abdominopelvic surgery with laparoscopy, open surgery, or both. DATA EXTRACTION: Two reviewers independently extracted study data and risk of bias. DATA SYNTHESIS: A total of 50 studies with 4898 patients were included. Of the 39 studies that reported incidence of Clavien-Dindo complications, 4 (10%) showed fewer complications with robot-assisted surgery. The majority of studies showed no difference in intraoperative complications, conversion rates, and long-term outcomes. Overall, robot-assisted surgery had longer operative duration than laparoscopy, but no obvious difference was seen versus open surgery. LIMITATIONS: Heterogeneity was present among and within the included surgical subspecialties, which precluded meta-analysis. Several trials may not have been powered to assess relevant differences in outcomes. CONCLUSION: There is currently no clear advantage with existing robotic platforms, which are costly and increase operative duration. With refinement, competition, and cost reduction, future versions have the potential to improve clinical outcomes without the existing disadvantages. PRIMARY FUNDING SOURCE: None. (PROSPERO: CRD42020182027).

Thromboelastography-Based Profiling of Coagulation Status in Patients Undergoing Bariatric Surgery: Analysis of 422 Patients.

INTRODUCTION/PURPOSE: Some clinical indicators suggest hypercoagulability/hyperaggregability in patients with morbid obesity. Thromboelastography (TEG®) has been used to profile coagulation status in surgical patients. We aimed to assess coagulation profiles in patients with morbid obesity undergoing bariatric surgery by correlating demographic and patient characteristics to pre-operative TEG® values. MATERIALS AND METHODS: Pre-operative TEG® values from 422 patients undergoing bariatric surgery were evaluated. TEG® results were analyzed by gender, use of medications known to alter the coagulation profile, and body mass index (BMI). RESULTS: Patients have a mean of 45.03 ± 11.8 years, female (76.3%), and with a mean BMI of 42 kg/m 1. The overall coagulation profile of female patients was significantly different from males, even in the sub-cohort without use of medications known to alter coagulation. The majority of patients (94%) with a G value > 15 dynes/cm 1 (clot strength) were female. In females, there was no association between BMI and TEG® values; however, in men, there was a statistically significant difference in TEG® values for those with BMI < 40 kg/m 1 compared to those with BMI > 50 kg/m2. CONCLUSIONS: TEG®-based analysis of coagulation profiles offers unique insights. Compared to laboratory normal values (R time, angle, maximal amplitude, and G values), patients with morbid obesity may have a tendency for hypercoagulability/hyperaggregability, with mean values at the higher limit. A significant hypercoagulable difference in TEG® values was identified in female as compared to male patients. Male patients with a BMI greater than 50 kg/m2 were also found to be increasingly hypercoagulable.