Proposal and multicentric validation of a laparoscopic Roux-en-Y gastric bypass surgery ontology.

BACKGROUND: Phase and step annotation in surgical videos is a prerequisite for surgical scene understanding and for downstream tasks like intraoperative feedback or assistance. However, most ontologies are applied on small monocentric datasets and lack external validation. To overcome these limitations an ontology for phases and steps of laparoscopic Roux-en-Y gastric bypass (LRYGB) is proposed and validated on a multicentric dataset in terms of inter- and intra-rater reliability (inter-/intra-RR). METHODS: The proposed LRYGB ontology consists of 12 phase and 46 step definitions that are hierarchically structured. Two board certified surgeons (raters) with > 10 years of clinical experience applied the proposed ontology on two datasets: (1) StraBypass40 consists of 40 LRYGB videos from Nouvel Hôpital Civil, Strasbourg, France and (2) BernBypass70 consists of 70 LRYGB videos from Inselspital, Bern University Hospital, Bern, Switzerland. To assess inter-RR the two raters' annotations of ten randomly chosen videos from StraBypass40 and BernBypass70 each, were compared. To assess intra-RR ten randomly chosen videos were annotated twice by the same rater and annotations were compared. Inter-RR was calculated using Cohen's kappa. Additionally, for inter- and intra-RR accuracy, precision, recall, F1-score, and application dependent metrics were applied. RESULTS: The mean ± SD video duration was 108 ± 33 min and 75 ± 21 min in StraBypass40 and BernBypass70, respectively. The proposed ontology shows an inter-RR of 96.8 ± 2.7% for phases and 85.4 ± 6.0% for steps on StraBypass40 and 94.9 ± 5.8% for phases and 76.1 ± 13.9% for steps on BernBypass70. The overall Cohen's kappa of inter-RR was 95.9 ± 4.3% for phases and 80.8 ± 10.0% for steps. Intra-RR showed an accuracy of 98.4 ± 1.1% for phases and 88.1 ± 8.1% for steps. CONCLUSION: The proposed ontology shows an excellent inter- and intra-RR and should therefore be implemented routinely in phase and step annotation of LRYGB.

Tailored access to the hepatobiliary system in post-bariatric patients: a tertiary care bariatric center experience.

BACKGROUND: In bariatric surgery patients, pancreaticobiliary access via endoscopic retrograde cholangiopancreatography (ERCP) is technically challenging and the optimal approach for the evaluation and treatment of biliary tree-related pathologies has been debated. Besides laparoscopy-assisted ERCP (LA-ERCP) as standard of care, EUS-directed transgastric ERCP (EDGE) and hepaticogastrostomy (HGS) with placement of a fully covered metal stent have emerged as novel techniques. The objective of this study was to evaluate safety and efficacy of three different endoscopic approaches (LA-ERCP, EDGE, and HGS) in bariatric patients. METHODS: In this retrospective review, consecutive patients with Roux-en-Y gastric bypass (RYGB) and Sleeve Gastrectomy (SG) who underwent from 2013 to 2019 a LA-ERCP, an EDGE, or a HGS at a tertiary care reference center for bariatric surgery were analyzed. Patient demographics, type of procedure and indication, data regarding cannulation and therapeutic intervention of the common bile duct (procedure success), and clinical outcomes were analyzed. RESULTS: A total of 19 patients were included. Indications for LA-ERCP, EDGE, or HGS were mostly choledocholithiasis (78.9%) and in a few cases papillitis stenosans. Eight patients (57.1%) with LA-ERCP underwent concomitant cholecystectomy. Procedure success was achieved in 100%. Adverse events (AEs) were identified in 15.7% of patients (all ERCP related). All AEs were rated as moderate and there were no serious AEs. CONCLUSION: This case series indicates that ERCP via a transgastric approach (LA-ERCP, EDGE, or HGS) is a minimally invasive, effective, and feasible method to access the biliary tree in bariatric patients. These techniques offer an appealing alternative treatment option compared to percutaneous transhepatic cholangiography and drainage- or deep enteroscopy-assisted ERCP. In bariatric patients who earlier had a cholecystectomy, EUS-guided techniques were the preferred treatment options for biliary pathologies.

[Internal hernias after bariatric and metabolic surgery]. / Innere Hernien nach bariatrischer und metabolischer Chirurgie.

Internal hernias after bariatric and metabolic surgery Abstract. Internal hernias are among the most common long-term complications of morbid obesity following gastric bypass procedures. The diagnosis of an internal hernia after a gastric bypass is often uncertain due to unspecific clinical symptoms and is difficult despite various diagnostic procedures. This fact requires special attention in the postbariatric follow-up after gastric bypass surgery and the knowledge of the possibility of the development of internal hernias. In addition, the recurrence rate after surgical treatment is not insignificant.

Pharmacokinetics and pharmacodynamics of single doses of rivaroxaban in obese patients prior to and after bariatric surgery.

AIMS: Venous thromboembolism is an important cause of postoperative morbidity and mortality in bariatric surgery. Studies of direct oral anticoagulants (DOACs) are not available in this surgical field. The objective of this phase 1 clinical trial was to investigate pharmacokinetic and pharmacodynamic (PK/PD) parameters of rivaroxaban in bariatric patients. METHODS: In this single-centre study, obese patients received single oral doses of rivaroxaban (10 mg) 1 day prior to and 3 days after bariatric surgery. PK and PD parameters were assessed at baseline and during 24 h after drug ingestion. RESULTS: Six Roux-en-Y gastric bypass patients and six sleeve gastrectomy patients completed the study. Mean rivaroxaban area under plasma concentration-time curve, peak plasma concentration, time to peak plasma concentration and terminal half-life were 971.9 µg·h l-1 (coefficient of variation: 10.6), 135.3 µg l-1 (26.7), 1.5 h and 13.1 h (34.1) prior to and 1165.8 (21.9), 170.0 (15.9), 1.5 and 8.9 (44.6) postsurgery for SG patients and 933.7 µg·h l-1 (22.3), 136.5 µg l-1 (10.7), 1.5 h und 13.8 h (46.6) prior to and 1029.4 (7.4), 110.8 (31.8), 2.5 and 15 (60.0) postsurgery for Roux-en-Y gastric bypass patients, respectively. Prothrombin fragments (F1 + 2) decreased during the first 12 hours and increased thereafter in the pre- and the postbariatric setting. Thrombin-antithrombin complexes dropped within 1-3 h in the prebariatric setting and remained low after surgery until they increased at 24 h postdose. Rivaroxaban was well tolerated and no relevant safety issues were observed. CONCLUSIONS: Bariatric surgery does not appear to alter PK of rivaroxaban in a clinically relevant way. Effective prophylactic postbariatric anticoagulation is supported by changes in PD.

Re-sleeve gastrectomy as revisional bariatric procedure after biliopancreatic diversion with duodenal switch.

BACKGROUND: Re-sleeve gastrectomy (re-SG) is a possible option to increase weight loss after biliopancreatic diversion with duodenal switch (BPD-DS). We report the feasibility, efficacy and safety of re-SG in patients presenting with long-term weight regain after BPD-DS. METHODS: From October 2010 to December 2013, a total of 17 patients (12 female, 5 male) with a mean age of 42.1 ± 19.4 years underwent re-SG, mainly because of weight regain after BPD-DS. Re-SG was performed laparoscopically over a 32 French stomach tube. RESULTS: At the time of BPD-DS, the mean weight and BMI of all patients were 130.1 ± 17.9 kg and 46.1 ± 6.5 kg/m(2), respectively. The mean time interval between BPD-DS and re-SG was 63.1 ± 20.3 months. At the time of re-SG, the mean weight and BMI were 115.4 ± 14.2 kg and 39.8 ± 5.3 kg/m(2), and the %EWL after BPD-DS was 22.9 ± 17.4 %. Three conversions (17.6 %) to open surgery were required. No mortality occurred. One patient (5.9 %) developed a leak within the first week after re-SG that was treated conservatively with an endoluminal stent. The mean follow-up was 37.2 ± 7.1 months after re-SG. One- and three-year follow-up showed a mean weight, BMI, and cumulative %EWL of 96.0 ± 17.1 kg, 33.8 ± 7.3 kg/m(2), and 53.1 ± 18.3 % (17/17 patients; 100 %), and 100.3 ± 21.1 kg, 35.1 ± 8.3 kg/m(2), and 47.2 ± 19.7 % (13/17 patients; 76 %) after re-SG, respectively. CONCLUSIONS: This study shows that re-SG in patients with weight regain after BPD-DS is a feasible, effective and safe option as a revisional bariatric procedure. However, patients have to be carefully considered for revisional surgery since re-SG is associated with the potential risk of surgical complications.

Challenges in multi-centric generalization: phase and step recognition in Roux-en-Y gastric bypass surgery.

PURPOSE: Most studies on surgical activity recognition utilizing artificial intelligence (AI) have focused mainly on recognizing one type of activity from small and mono-centric surgical video datasets. It remains speculative whether those models would generalize to other centers. METHODS: In this work, we introduce a large multi-centric multi-activity dataset consisting of 140 surgical videos (MultiBypass140) of laparoscopic Roux-en-Y gastric bypass (LRYGB) surgeries performed at two medical centers, i.e., the University Hospital of Strasbourg, France (StrasBypass70) and Inselspital, Bern University Hospital, Switzerland (BernBypass70). The dataset has been fully annotated with phases and steps by two board-certified surgeons. Furthermore, we assess the generalizability and benchmark different deep learning models for the task of phase and step recognition in 7 experimental studies: (1) Training and evaluation on BernBypass70; (2) Training and evaluation on StrasBypass70; (3) Training and evaluation on the joint MultiBypass140 dataset; (4) Training on BernBypass70, evaluation on StrasBypass70; (5) Training on StrasBypass70, evaluation on BernBypass70; Training on MultiBypass140, (6) evaluation on BernBypass70 and (7) evaluation on StrasBypass70. RESULTS: The model's performance is markedly influenced by the training data. The worst results were obtained in experiments (4) and (5) confirming the limited generalization capabilities of models trained on mono-centric data. The use of multi-centric training data, experiments (6) and (7), improves the generalization capabilities of the models, bringing them beyond the level of independent mono-centric training and validation (experiments (1) and (2)). CONCLUSION: MultiBypass140 shows considerable variation in surgical technique and workflow of LRYGB procedures between centers. Therefore, generalization experiments demonstrate a remarkable difference in model performance. These results highlight the importance of multi-centric datasets for AI model generalization to account for variance in surgical technique and workflows. The dataset and code are publicly available at https://github.com/CAMMA-public/MultiBypass140.

[Bariatric and metabolic surgery]. / Bariatrische und metabolische chirurgie.

The prevalence of obesity and its comorbidities is constantly rising and is one of the most threatening global health and economic problems worldwide. Whereas bariatric surgery is well accepted in the treatment of morbid obesity, surgical treatment for ist comorbidities (metabolic surgery) such as type 2 diabetes mellitus, dyslipidemia and other diseases are still under discussion. A more profound knowledge of its physiologic mechanisms is crucial for the future implementation of the bariatric and metabolic surgery to treat obesity-related comorbidities.

[Aftercare following bariatric surgery]. / Nachsorge nach bariatrischen operationen.

With the increase of patients after bariatric and metabolic surgery the long-term follow-up of this population will become a challenge. Bariatric patients require regular and life-long follow-up in order to affect the long-term achievements of this therapy in a positive way. For that reason bariatric patients should be followed in the first phase by a multidisciplinary team of the bariatric centre. Taking into account some fundamental considerations general practinioner should be involved in the care of these patients when a stable situation occured.

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

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

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

Importance: Venous thromboembolism (VTE) is a leading cause of morbidity and mortality after bariatric surgery. Clinical end point studies on thromboprophylaxis with direct oral anticoagulants in patients undergoing bariatric surgery are lacking. Objective: To assess the efficacy and safety of a prophylactic dose of 10 mg/d of rivaroxaban for both 7 and 28 days after bariatric surgery. Design, Setting, and Participants: This assessor-blinded, phase 2, multicenter randomized clinical trial was conducted from July 1, 2018, through June 30, 2021, with participants from 3 academic and nonacademic hospitals in Switzerland. Intervention: Patients were randomized 1 day after bariatric surgery to 10 mg of oral rivaroxaban for either 7 days (short prophylaxis) or 28 days (long prophylaxis). Main Outcomes and Measures: The primary efficacy outcome was the composite of deep vein thrombosis (symptomatic or asymptomatic) and pulmonary embolism within 28 days after bariatric surgery. Main safety outcomes included major bleeding, clinically relevant nonmajor bleeding, and mortality. Results: Of 300 patients, 272 (mean [SD] age, 40.0 [12.1] years; 216 women [80.3%]; mean body mass index, 42.2) were randomized; 134 received a 7-day and 135 a 28-day VTE prophylaxis course with rivaroxaban. Only 1 thromboembolic event (0.4%) occurred (asymptomatic thrombosis in a patient undergoing sleeve gastrectomy with extended prophylaxis). Major or clinically relevant nonmajor bleeding events were observed in 5 patients (1.9%): 2 in the short prophylaxis group and 3 in the long prophylaxis group. Clinically nonsignificant bleeding events were observed in 10 patients (3.7%): 3 in the short prophylaxis arm and 7 in the long prophylaxis arm. Conclusions and Relevance: In this randomized clinical trial, once-daily VTE prophylaxis with 10 mg of rivaroxaban was effective and safe in the early postoperative phase after bariatric surgery in both the short and long prophylaxis groups. Trial Registration: ClinicalTrials.gov Identifier: NCT03522259.

The impact of bariatric and metabolic surgery on cancer development.

Obesity (BMI ≥ 30 kg/m2) with related comorbidities such as type 2 diabetes mellitus, cardiovascular disease, sleep apnea syndrome, and fatty liver disease is one of the most common preventable risk factors for cancer development worldwide. They are responsible for at least 40% of all newly diagnosed cancers, including colon, ovarian, uterine, breast, pancreatic, and esophageal cancer. Although various efforts are being made to reduce the incidence of obesity, its prevalence continues to spread in the Western world. Weight loss therapies such as lifestyle change, diets, drug therapies (GLP-1-receptor agonists) as well as bariatric and metabolic surgery are associated with an overall risk reduction of cancer. Therefore, these strategies should always be essential in therapeutical concepts in obese patients. This review discusses pre- and post-interventional aspects of bariatric and metabolic surgery and its potential benefit on cancer development in obese patients.

Vasoconstrictor nasal spray causing life-threatening complications after bariatric surgery: A case report.

INTRODUCTION AND IMPORTANCE: Bariatric surgery is an evolving surgical field with increasing cases per year, as obesity is prevalent, especially in developed countries. Complication diagnosis and management can be challenging. Marginal ulcers and anastomosis perforation are rare, but their incidence is likely underestimated. CASE PRESENTATION: To the best of our knowledge, we present the first case with a two and a half years history of recurrent ischemia, marginal ulcers, and recurrent perforation after laparoscopic omega loop gastric bypass, most likely due to an abuse of an over-the-counter (OTC) sympathomimetic nasal spray. The complications (Clavien-Dindo classification IIIb) caused the necessity of recurrent hospitalizations and diagnostic interventions and an open conversion into Roux-Y gastric bypass in a damage control manner. CLINICAL DISCUSSION AND CONCLUSION: Conclusively, we advocate evaluating drug abuse, including OTC medications that patients might not report on a daily-based medical history, as an etiology for marginal ulcers and anastomosis perforation, especially in late and recurrent cases.

Ulcer Disease in the Excluded Segments after Roux-en-Y Gastric Bypass: a Current Review of the Literature.

Ulcer disease in excluded segments after Roux-Y gastric bypass (RYGB) is rare but can evolve into a life-threatening situation. The excluded segments exhibit a different behavior from that of non-altered anatomy; perforated ulcers do not result in pneumoperitoneum or free fluid, and therefore must be met with a low threshold for surgical exploration. The anatomical changes after RYGB impede routine access to the remnant stomach and duodenum. There are various options to address bleeding or perforated ulcers. While oversewing and drainage preserves the anatomy and forgoes resection, remnant gastrectomy offers a definitive solution. The importance of traditional risk factors such as smoking or use of non-steroidal anti-inflammatory drugs is unclear. Eradication of Helicobacter pylori and secondary prophylaxis with proton-pump inhibitors is advisable, albeit in double-dose.

Mental Illness Has a Negative Impact on Weight Loss in Bariatric Patients: a 4-Year Follow-up.

BACKGROUND: Mental health disorders are highly prevalent among bariatric surgery patients. Bariatric surgery induces weight loss with continuous health improvements. However, long-term follow-up data on weight loss and quality of life data of patients who have a mental illness after bariatric surgery are scarce, and it is not clear whether mental illness is associated with more pronounced weight regain. The aim was to investigate the impact of preoperative mental illness on the course of long-term weight changes after bariatric surgery. METHODS: Patients with sleeve gastrectomy (SG) or Roux-en-Y gastric bypass surgery (RYGB) between 2005 and 2013 with a follow-up of at least 3 years were included. The study population was divided into two groups: patients with mental illness (MI) and patients without (No-MI). Weight loss outcomes over time were compared using mixed models up to 4 years after surgery. RESULTS: In total, 254 patients (RYGB 61.0%, SG 39%) were included. The distribution of baseline characteristics was similar between the MI (n = 108) and No-MI groups (n = 146). The most prevalent mental illness was depressive disorder (63.9%). In the MI group, the percent of total weight loss (%TWL) was significantly smaller over the study period. After 36 months, the predicted mean group-difference of %TWL was 4.6% (95% CI 1.9, 7.2; p = 0.001), and the predicted odds ratio for weight regain was 4.9 (95% CI 1.6, 15.1) for patients in the MI group. CONCLUSION: Preoperative mental illness leads to lower long-term weight loss and an increased risk of weight regain after bariatric surgery.

Expression and hypoxic regulation of the endothelin system in endocrine cells of human and rat pancreatic islets.

CONTEXT: The success of pancreatic islet transplantation depends largely on the capacity of the islet graft to survive the initial phase immediately after transplantation until revascularization is completed. Endothelin-1 (ET-1) is a strong vasoconstrictor which has been involved in solid organ graft failure but is also known to be a potent mitogenic/anti-apoptotic factor which could also potentially enhance the survival of the transplanted islets. OBJECTIVE: Characterization of the endothelin system with regard to a potential endothelin agonist/antagonist treatment. DESIGN: Regulated expression of the endothelin system in human and rat pancreatic islets and beta-cell lines was assessed by means of immunohistochemistry, competition binding studies, western blot, RT-PCR, real-time PCR and transplant studies. RESULTS: ET-1, ETA- and ETB-receptor immunoreactivity was identified in the endocrine cells of human and rat pancreatic islets. The corresponding mRNA was detectable in rat beta-cell lines and isolated rat and human pancreatic islets. Competition binding studies on rat islets revealed binding sites for both receptor types. ET-1 stimulated the phosphorylation of mitogen-activated protein kinase, which was prevented by ETA- and ETB-receptor antagonists. After exposure to hypoxia equal to post-transplant environment oxygen tension, mRNA levels of ET-1 and ETB-receptor of human islets were robustly induced whereas ETA-receptor mRNA did not show significant changes. Immunostaining signals for ET-1 and ETA-receptor of transplanted rat islets were markedly decreased when compared to native pancreatic sections. CONCLUSIONS: In pancreatic islets, ET-1 and its receptors are differentially expressed by hypoxia and after transplantation. Our results provide the biological basis for the study of the potential use of endothelin agonists/antagonists to improve islet transplantation outcome.

Radiologic, endoscopic, and functional patterns in patients with symptomatic gastroesophageal reflux disease after Roux-en-Y gastric bypass.

BACKGROUND: Roux-en-Y gastric bypass (RYGB) is considered the gold standard in treatment of morbid obesity and gastroesophageal reflux disease (GERD). Resolution of GERD symptoms is reported to be approximately 85% to 90%. OBJECTIVE: To evaluate patients with persistent GERD symptoms after RYGB and to identify contributing factors. SETTING: University hospital, cross-sectional study. METHODS: Data of patients evaluated for persistent GERD with a history of RYGB between January 2012 and December 2015 were reviewed. GERD was assessed with questionnaires, endoscopy, 24-hour pH-impendance manometry, and barium swallow. RESULTS: Of 47 patients, 44 (93.6%) presented with typical GERD, 18 (38.3%) with obstruction, 8 (17%) with pulmonary symptoms, and 21 (44.7%) with pain. The interval between RYGB and evaluation was a median of 3.8 years (range .8-12.6); median patient age was 36.5 years (19.1-67.2). Median body mass index was 30.3 kg/m2 (20.3-47.2). Pouch gastric fistulas were seen in 2 (5.1%), enlarged pouches in 5 (10.6%), and hiatal hernias in 25 patients (53.2%). Twelve (23.4%) had esophagitis>Los Angeles (LA) grade B. Manometry was performed in 45 (95.7%) and off-proton pump inhibitor 24-hour pH-impedance-metry in 44 patients (94.6%). Seventeen patients (37.8%) had esophageal hypomotility or aperistalsis; hypotensive lower esophageal sphincter was seen in 26 patients (57.8%). Increased esophageal acid exposure (>4% pH<4) was found in 27 (61.4%), an increased number of reflux episodes (>53) in 30 patients (68.2%). Symptoms were deemed as functional in 6 (12.8%). CONCLUSION: The evaluation for persistent GERD after RYGB revealed a high percentage of hiatal hernias, hypotensive lower esophageal sphincter, and severe esophageal motility disorders. These findings might have an influence on hiatal hernia closure concomitant with RYGB and the role of pH manometry in the preoperative bariatric assessment.

The effect of bariatric surgery on the direct oral anticoagulant rivaroxaban: the extension study.

BACKGROUND: Thromboembolic disease is a potentially serious complication in bariatric surgery patients. Direct oral anticoagulants (DOAC) have been investigated in orthopedic surgery patients. DOAC data after bariatric surgery are still limited to the early postsurgical period. Whether postsurgical midterm adaptations due to anatomic and physiologic alterations influence drug pharmacology is currently not known. OBJECTIVE: The aim of this study was to investigate the influence of weight loss and type of bariatric surgery on midterm postsurgical pharmacokinetic and pharmacodynamic parameters of rivaroxaban. SETTING: University hospital. METHODS: In this monocentric study, bariatric patients received a single oral dose of rivaroxaban (10 mg) 6 to 8 months after sleeve gastrectomy (SG) or Roux-en-Y-gastric bypass (RYGB). Pharmacokinetic and pharmacodynamic parameters were assessed and compared with prebariatric surgery results. RESULTS: We included 6 RYGB and 6 SG patients. Percent excess weight loss was 71.4% (interquartile range 56.4, 87.9) in the SG group and 76.6% (64.5, 85.7) in the RYGB group. Rivaroxaban mean areas under the curve 6 to 8 months after the bariatric procedure (922.4 µg × h/L, coefficient of variation 43.2) were comparable to those measured preoperatively (952.6 µg × h/L, 16.8). There was no relevant difference between the 2 surgical procedure groups. Rivaroxaban led to a decrease of prothrombin fragments F1+2 over 12 hours after oral intake confirming in vivo efficacy. CONCLUSIONS: Significant weight loss and altered anatomy after RYGB and SG procedures do not appear to affect the pharmacokinetics and pharmacodynamics of prophylactic rivaroxaban. A single dose of Rivaroxaban was well tolerated and considered safe in this trial.

Prevalence and Prediction of Obstructive Sleep Apnea Prior to Bariatric Surgery-Gender-Specific Performance of Four Sleep Questionnaires.

PURPOSE: Bariatric surgery (BS) is a treatment option for morbid obesity leading to substantial and sustained weight loss in adults. As obstructive sleep apnea (OSA) is highly prevalent in obese subjects and may increase the perioperative risk, screening for OSA is recommended prior to BS. In clinical routine, BS is performed more frequently in women. Therefore, we sought to assess the gender-specific performance of four sleep questionnaires (Epworth Sleepiness Scale (ESS), Fatigue Severity Scale (FSS), STOPBang, and NoSAS) to predict moderate to severe OSA in the morbidly obese population. MATERIAL AND METHODS: We applied all four questionnaires to patients scheduled for BS with polygraphic OSA screening at our institution between 2012 and 2015 and performed gender-specific sensitivity analyses. RESULTS: We included 251 bariatric patients (76% female, median age 39 years, median BMI 42.0 kg/m2). OSA (AHI > 5/h; AHI > 15/h) was present in 43% (females 35%, males 68%; p < 0.001) and 21% (females 13%, males 45%; p < 0.001). STOPBang and NoSAS performed markedly better than ESS and FSS. With the exception of the ESS, all sleep questionnaires allowed better OSA prediction in women than in men. CONCLUSION: In obese patients scheduled for BS, a gender-specific difference was observed in the performance of the evaluated OSA screening questionnaires. This needs to be considered when these questionnaires are used. Our results underline the need for better gender-specific OSA screening algorithms in morbidly obese patients.

Impaired vascular function in normoglycemic mice prone to autoimmune diabetes: role of nitric oxide.

Type 1 diabetes is an immuno-inflammatory condition which increases the risk of cardiovascular disease, particularly in young adults. This study investigated whether vascular function is altered in mice prone to autoimmune diabetes and whether the nitric oxide (NO)-cyclic GMP axis is involved. Aortic rings suspended in organ chambers and precontracted with phenylephrine were exposed to cumulative concentrations of acetylcholine. To investigate the role of NO, some experiments were performed in the presence of either 1400W (N-(3-aminomethyl)benzyl-acetamidine hydrochloride), a selective inhibitor of the iNOS-isoform, L-NAME (N(G)-nitro-L-arginine methyl ester hydrochloride), an inhibitor of all three NOS-isoforms, or ODQ (1H-[1,2,4]oxadiazolo[4,3-a]quinoxalin-1-one), a selective inhibitor of guanylate cyclase. Moreover, contractility to phenylephrine, big endothelin-1, and endothelin-1 was assessed and histological analysis and iNOS immunohistochemistry were performed. Endothelium-dependent relaxation was reduced in prediabetic NOD mice (78+/-4 vs. 88+/-2%, respectively, P<0.05 vs. control) despite normal plasma glucose levels (n.s. vs. control). Preincubation with 1400W further attenuated responses in prediabetic (P<0.05 vs. untreated) but not in diabetic or in control mice. In contrast, basal NO bioactivity remained unaffected until the onset of diabetes in NOD mice. Contractile responses to big endothelin-1 and endothelin-1 were reduced in prediabetic animals (P<0.05 vs. control), whereas in diabetic mice only responses to big endothelin-1 were decreased (P<0.05 vs. control). These data demonstrate that endothelium-dependent and -independent vascular function in NOD mice is abnormal already in prediabetes in the absence of structural injury. Early proinflammatory activation due to iNOS in diabetes-prone NOD mice appears to be one of the mechanisms contributing to impaired vasoreactivity.