Its use was primarily widespread in Australia and European countries due to its relative simplicity, reversibility, and safety profile [12]. Since the approval of the LAP-BAND^® (Apollo Endosurgery, Austin, TX) system in the USA in 2001, its use has grown significantly and is now considered a well-established bariatric procedure with good medium and long-term results in terms of sustained weight loss [18, 19]. LAGB is a purely restrictive procedure that can be routinely performed in an outpatient setting; however, gastric banding is an implantable device that can be associated with late complications such as band slippage or erosion, gastric prolapse, pouch enlargement, and tubing/access port complication, which in the long term will require either band revision or explantation in a high percentage of patients [20–23].

Laparoscopic roux-en-Y gastric bypass (RYGB) is considered the gold standard for the surgical treatment of morbid obesity due to its greater weight loss and lower rates of weight regain when compared with other bariatric procedures, becoming one of the most commonly performed bariatric surgeries in the USA [17]. This combined, malabsorptive/restrictive procedure induces weight loss by several mechanisms: by gastric restriction and early satiety, the volume of food to be consumed is decreased and ultimately the amount of caloric intake and by malabsorption which is created by bypassing the foregut delivering enteral nutrition directly into the mid small intestine avoiding the nutrient absorptive circuit. Bypassing the foregut also induces anorexia by alteration of hormone secretion [24].

Sleeve Gastrectomy (SG), which is the fastest growing procedure in bariatric surgery [17], was first performed laparoscopically in 1999 [11]. Subsequently it was used as a first step in a staged concept for high-risk patients undergoing bariatric surgery. The rationale for this approach was to lower the morbidity of a complex surgical procedure by offering a less challenging operation, decreasing operative time, and allowing patients to lose weight before proceeding with the second stage. However, as a consequence of the proven outcomes in terms of excellent weight loss and resolution of comorbidities, it is now being increasingly favored as a stand-alone procedure [25–27]. Initially conceived of as a purely restrictive surgery, it has been shown that laparoscopic sleeve gastrectomy (LSG) has strong metabolic effects probably due to accelerated gastric emptying, early satiety, reduction of the ghrelin-producing cell mass after resection of the gastric fundus, and complex neurohormonal regulation of intestinal hormones [14, 28].

The latest systematic review and meta-analyses of robotic-assisted bariatric surgery was published in 2013 [51]. Two previous systematic reviews were published in 2011 [51] and 2012 [52], but the first one did not include SG in their analysis.

Even though the last systematic review and meta-analysis has major limitations such as the low quality of the studies, sample size, and lack of important information such as bariatric and metabolic outcomes, the study suggests that robotic bariatric surgery is feasible independently of the type of procedure performed and safe based on complications, reoperations, and 30-day postoperative mortality rates.

A lower complication profile, specifically anastomotic leak, strictures, and bleeding, a shorter learning curve, and the ease to carry out complex maneuvers such as gastrointestinal anastomosis in RYGB and vertical gastric resection in SG are named as the main advantages of robotic surgery over open and laparoscopic approaches. The main disadvantage was the cost of the robotic platform.

Thirty-day postoperative mortality was zero regardless of the procedure and the rate of postoperative complications was 4.26 % for major and 1 % for minor in RYGB and 1.2 and 0 % for SG. An updated systematic review and meta-analysis of laparoscopic and open bariatric surgery published in 2014 [53] showed a 30-day postoperative mortality rate between 0.11 and 0.07 % for RYGB and 0.50 and 0.29 % for SG. Complication rate for laparoscopic and open RYGB was 21 and 13 % for SG. Specific surgical complications were not mentioned in this meta-analysis.

The systematic review published in 2012 by Fourman and Saber compared the outcomes of robotic bariatric surgery versus laparoscopic bariatric surgery [52]. They found a mean complication rate for all robotic procedures of 10.2 % versus 12.6 % for the conventional laparoscopic approach. The learning curve was measured for RYGB and proved to be shorter for robotic than laparoscopic approach (10–15 vs. ≥100). No major differences were observed for mean hospital stay or excess body weight loss when these variables were reported. The strongest advantages of robotic surgery found in this study were the shorter learning curve, lower leak rate for gastrojejunal anastomosis, improved ergonomics, and less operator fatigue. The major drawback was also the cost of the robotic system and its maintenance.

The most recent systematic review of single-incision bariatric surgery was published by Moreno-Sanz and colleagues in 2014, and included 13 observational studies and 1 randomized control study with a total of 2,357 patients analyzed [52]. The study concluded that single-incision bariatric surgery is a feasible option when the patients are correctly selected and the procedure is carried out by an expert bariatric surgeon knowledgeable in single-incision techniques. Conversion rate to laparoscopic approach was 2.4 % for LAGB and 1.83 % for SG. No conversions were observed among the RYGB cases. The use of an additional trocar to complete the case was reported in 3 of 8 studies of LAGB, in 1 of 4 of SG, and in 1 of 2 studies for RYGB. Overall morbidity rate was 4.8 % for single-incision versus 5 % for conventional laparoscopic approach, and the predominance was for minor complications. Interestingly, no differences were observed in terms of wound complications. Mortality was 0.005 % of all single-incision cases and was represented by one case in the AGB group.

No differences were observed on percentage of weight loss and improvement of comorbidities.

The main advantages observed with single-incision approach were reduced analgesic consumption and improved cosmesis. Disadvantages were longer operative times in almost all single-incision groups. In terms of costs, no significant differences were found between groups; however, if lower morbidity rates, necessity of reoperations, and reduced length of stay associated with single-incision access are achieved, this technique could be more cost-effective.

Bariatric surgery has been continually evolving to shift from open procedures to minimally invasive approaches, considering laparoscopy as the gold standard nowadays. The state-of-the-art surgeries are still changing to improve their safety profile and technique, as the case of the laparoscopic gastric plication, a similar procedure to laparoscopic sleeve gastrectomy, which involves the creation of gastric folds by a suture line to reduce the size of the stomach.

Research interests are now focused on approaches and procedures that have similar mechanisms to surgery but less invasiveness aiming at developing durable, reversible, easier, and safer treatment options. Current and ongoing studies have delivered promising results with endoscopy, endoluminal surgery, and natural orifice translumenal endoscopic surgery; however, many of those techniques are still in there study phase or are considered as experimental due to the lack of controlled data, even when they have been used for several years already (Table 33.1).