Phd in EXPERIMENTAL AND CLINICAL HEPATO-GASTROENTEROLOGY

Thesis title: L’USO DELLA FLUORANGIOGRAFIA CON ICG DURANTE SADI-S LAPAROSCOPICA DI REVISIONE, SLEEVE GASTRECTOMY E BYPASS GASTRICO ROUX-EN-Y

Bariatric surgery is the optimal treatment for obesity and related diseases. Nevertheless, many patients regain weight, especially if they have undergone restrictive procedures, or develop gastroesophageal reflux symptoms, requiring bariatric re-surgery. The most performed revision procedures are Roux-en-Y gastric bypass (RYGB) or One Anastomosis Gastric Bypass (OAGB), with good long-term results, but there are still insufficient data to identify the standard procedure to use in these cases. One of the most recently introduced procedures, also proposed as revision surgery, is the Single Anastomosis Duodeno-Ileal Switch (SADI-S). SADIS was introduced with the aim of both simplifying the classic technique of Biliopancreatic Diversion with Duodenal Switch (DS) and preventing the onset of bile reflux after OAGB by preserving the pylorus. SADI-S is a less demanding procedure than classic DS due to the presence of a single anastomosis and it has good results in terms of both weight loss and of resolution of related comorbidities, whether performed as primary surgery or revision surgery. The aim of this prospective observational study is to evaluate intraoperatively the vascularization of the first portion of the duodenum during SADIS using intraoperative indocyanine green (ICG) fluorangiography (ICG) in patients undergoing bariatric revision surgery, and comparison with the assessment of vascularization during Laparoscopic Sleeve Gastrectomy (LSG) and RYGB. Secondary outcomes are body weight loss at a mean follow-up of six months and resolution or improvement of obesity-related comorbidities. Intraoperative fluoroscopy with ICG was evaluated in 25 patients undergoing primary or revision bariatric surgery at the Departmental Unit of Bariatric Surgery, Department of General, Specialized Surgery, and Anesthesiology, Policlinico Umberto I, Sapienza University of Rome. Based on the preoperative study and after multidisciplinary evaluation, patients candidates for primary bariatric surgery and without Gastroesophageal reflux disease (GERD) underwent SGL (10 patients), patients candidates for primary bariatric surgery and with GERD underwent RYGB (10 patients), and patients candidates for revision surgery and without Barrett's esophagus, reflux esophagitis, or large hiatal hernia underwent SADI-S (5 patients). Patients underwent postoperative follow-up at 3, 6, and 12 months. Each patient was administered with 0.2 ml/kg of ICG intravenously, after receiving intravenous desensitizing premedication 30 minutes prior to the ICG injection. Intravenous administration of ICG was performed after creation of the gastric tube during SGL, after gastro-jejunal anastomosis during RYGB, after skeletonization of the first duodenal portion, and after duodeno-ileal anastomosis during SADI-S. The degree of vascularization was assessed using a visual scale, assigning a score from 1 to 5 based on the intensity of fluorescence of the vascularized structures, as perceived by the surgical team. A score of 1-2 was considered unsatisfactory and led to a change in surgical strategy; a score of 3 or higher was considered satisfactory and allowed the planned surgical strategy to continue. Preoperative variables (gender, age, BMI, comorbidities, ASA class, data from gastroscopy such as the presence of hiatal hernia, cardial incompetence, and the presence of esophagitis and/or gastritis, Helicobacter pylori eradication, and previous abdominal surgery), intraoperative variables (type of surgery performed, associated procedures, ICG fluorescence score, methylene blue test result, conversion rate to open surgery, operating time, postoperative complications, postoperative hospital stay, and mortality) and postoperative variables at 3, 6, and 12 months after surgery (BMI, percentage of excess body mass loss, trend in associated comorbidities) were analysed. No anastomotic leaks were observed in this study; however, ICG-enhanced fluoroscopy allowed the identification of possible areas of dehiscence in three patients (12%) that would otherwise have remained undetected, thus enabling the prevention of complications through a change in the intraoperative surgical strategy. Furthermore, it showed that during SADI-S, the use of ICG is extremely helpful in recognizing the anatomy, as well as the vascularization, presenting a series of patients that is still poorly described in the literature. The small sample size is a limitation of the study; however, if our results are confirmed by studies with a larger sample of patients, the use of ICG could be a valid option in the prevention of dehiscence in bariatric surgery. In conclusion, based on this study, ICG-enhanced fluoroscopy in bariatric surgery is a safe and easy-to-perform procedure that could reduce the number of leaks, especially in patients undergoing revision surgery, although a standardized protocol for its use is still lacking. Further prospective studies with a larger number of patients and randomized controlled trials are needed to compare ICG with other leak tests and reduce the risk of leaks in bariatric surgery, as well as to create a standardized protocol for its use.