[Quality of indications in bariatric surgery]. / Indikationsqualität in der Adipositaschirurgie.

Bariatric and metabolic surgery is increasingly being utilized in Germany and also worldwide. Due to the increased perioperative risk compared to non-obese patients, a detailed and accurate preoperative assessment of the patient is pivotal to improve postoperative and long-term outcomes. The indications for bariatric surgery have shifted in recent years from a certain body mass index (BMI) to comorbidity-based indications. In 2018 the German S3 guidelines for metabolic surgery defined the indications for bariatric surgery as well as the preoperative assessment. The indications for bariatric metabolic operations should be assessed by an interdisciplinary team consisting of surgeons, internists, diabetologists, psychologists and dietitians. It is paramount that surgeon and patient define realistic goals of these operations. Also, the different types of bariatric operation and their long-term consequences should be discussed. Additionally, a thorough endocrinological assessment by an internist or diabetologist with respect to relevant comorbidities of obesity as well as the adjustment of existing therapies are important. An assessment by a mental health professional is also mandatory; however, psychological comorbidities are not a contraindication as long as the patient is being treated and the disease is controlled. A preoperative short-term high-protein and low-carbohydrate fluid nutrition helps to reduce the risk of postoperative complications, especially for patients with a high BMI. A preoperative weight loss in the sense of a mandatory loss of a defined proportion of the body weight is not useful.

Feasibility and effectiveness of laparoscopic transgastric stapler-assisted circumferential esophageal mucosectomy and simultaneous fundoplication in a pig model.

Laparoscopic transgastric stapler-assisted mucosectomy (SAM) has been described for minimally invasive circumferential en bloc resection of Barrett's esophagus (BE). Conceivably long-term disease control might be achieved by adding antireflux surgery after resection of BE by SAM. The aim of this study was to assess the feasibility of combined SAM and fundoplication in one laparoscopic procedure in six pigs. Furthermore, the competence of the gastroesophageal junction (GEJ) was assessed at baseline, after SAM, and after subsequent laparoscopic fundoplication. At each measuring point reflux measurements were repeated 6 times in each pig. Blue-colored water was infused into the stomach to provoke reflux. Intragastric yield pressure and volume were recorded until drainage of blue solution (DBS) was noted. Time to reflux was measured by DBS and by multichannel intraluminal impedance (MII). In all animals SAM followed by laparoscopic fundoplication was feasible in a single session. A weakening of the GEJ was found after SAM, indicated by decreased yield pressure (11.5 mmHg vs. 8.5 mmHg; P < 0.001), time to DBS (90 seconds vs. 60 seconds; P = 0.008) and MII (80 seconds vs. 33 seconds; P < 0.001). After additional Nissen fundoplication the GEJ competence was restored, with measurements returning to baseline values (time to DBS 99 seconds; P = 0.15; MII 76 seconds; P = 0.84). The yield pressure increased from 11.5 mmHg at baseline to 19.7 mmHg after SAM and fundoplication (P < 0.001). Laparoscopic fundoplication and SAM may be combined in a single laparoscopic session. Although the GEJ was weakened after SAM, Nissen fundoplication restored the GEJ as an effective reflux barrier in this experiment. For clinical validation, the results need to be confirmed in a prospective human trial.

Meta-analysis of hybrid natural-orifice transluminal endoscopic surgery versus laparoscopic surgery.

BACKGROUND: Hybrid natural-orifice transluminal endoscopic surgery (NOTES), combining access through a natural orifice with small-sized abdominal trocars, aims to reduce pain and enhance recovery. The objective of this systematic review and meta-analysis was to compare pain and morbidity in hybrid NOTES and standard laparoscopy. METHODS: A systematic literature search was performed to identify RCTs and non-RCTs comparing hybrid NOTES and standard laparoscopy. The main outcome was pain on postoperative day (POD) 1. Secondary outcomes were pain during the further postsurgical course, rescue analgesia, complications, and satisfaction with the cosmetic result. The results of meta-analysis in a random-effects model were presented as odds ratio (ORs) or standard mean differences (MDs) with 95 per cent confidence intervals. RESULTS: Six RCTs and 21 non-randomized trials including 2186 patients were identified. In hybrid NOTES the score on the numerical pain scale was lower on POD 1 (-0·75, 95 per cent c.i. -1·09 to -0·42; P = 0·001) and on POD 2-4 (-0·58, -0·91 to -0·26; P < 0·001) than that for standard laparoscopy. The need for rescue analgesia was reduced in hybrid NOTES (OR 0·36, 0·24 to 0·54; P < 0·001). The reduction in complications found for hybrid NOTES compared with standard laparoscopy (OR 0·52, 0·38 to 0·71; P < 0·001) was not significant when only RCTs were considered (OR 0·83, 0·43 to 1·60; P = 0·570). The score for cosmetic satisfaction was higher after NOTES (MD 1·14, 0·57 to 1·71; P < 0·001). CONCLUSION: Hybrid NOTES reduces postoperative pain and is associated with greater cosmetic satisfaction in selected patients.

Influence of cardiac flow rate on turbulent shear stress from a prosthetic heart valve.

Elevated turbulent shear stresses associated with sufficient exposure times are potentially damaging to blood constituents. Since these conditions can be induced by mechanical heart valves, the objectives of this study were to locate the maximum turbulent shear stress in both space and time and to determine how the maximum turbulent shear stress depends on the cardiac flow rate in a pulsatile flow downstream of a tilting disk valve. Two-component, simultaneous, correlated laser velocimeter measurements were recorded at four different axial locations and three different flow rates in a straight tube model of the aorta. All velocity data were ensemble averaged within a 15 ms time window located at approximately peak systolic flow over more than 300 cycles. Shear stresses as high as 992 dynes/cm2 were found 0.92 tube diameters downstream of the monostrut, disk valve. The maximum turbulent shear stress was found to scale with flow rate to the 0.72 power. A repeatable starting vortex was shed from the disk at the beginning of each cycle.