Let’s look at each in detail.

There are two outcomes which should be evaluated with any weight-loss procedure – excess weight loss (EWL) and reduction in medical comorbidities. LSG has been cited as providing superior weight loss to the laparoscopic adjustable gastric band (LAGB) (EWL 66 % vs. 48 %) [2]. Approximately 66–80 % of patients can expect complete remission of type II diabetes, hypertension, and hyperlipidemia with an even higher percentage experiencing partial remission [2]. This can be compared to the 70–80 % EWL and remission of comorbidities seen in the LRYGB [3].

Fifty-seven percent of morbidly obese individuals will have some form of nutritional deficiency preoperatively [4]. In this already malnourished population, the use of malabsorptive procedures (LRYGB and duodenal switch) can lead to increased deficiencies postoperatively. Nutritional deficiencies can occur over the short and long term in up to 35 % of patients undergoing a malabsorptive procedure. Vitamins A, B1, B6, B12, and D3 and macronutrients such as protein and micronutrients including zinc and iron are most commonly affected [4, 5]. While patients undergoing LSG can still experience nutritional deficiencies (specifically in protein), the overall rate is lower [4, 6].

Sleeve gastrectomy has been associated with significant hormonal effects. Most commonly implicated are more rapid gastric emptying, increase in postprandial cholecystokinin and glucagon-like peptide-1 concentrations, and reduced ghrelin release [7]. Together these have been implicated in increased satiety and weight loss as well as improved glucose metabolism.

The LSG is generally considered to be a less technically challenging procedure than the LRYGB. Operative times vary by surgeon, but studies have found the operative time for an LSG (82–101 min) to be significantly less than for the LRYGB (98–133 min) [8–10]. The overall rate of morbidity and mortality of the LSG has been found to be 5.2 % and 0.4 %, respectively [8]. This falls between that of the LAGB and the RNYGB. Most significant complications from the LSG occur as leaks or bleeding along the staple line created.

As previously discussed, the LSG was initially intended as the first stage of a staged procedure. The shorter operative time allows it to be safely performed on sicker patients with higher BMIs. While patients and their physicians are overwhelmingly pleased with initial outcomes, conversion to a second stage (RNYGB or DS) is still performed in approximately 2.2 % of patients to improve weight loss or reduce GERD symptoms [8].

There were initially concerns about the long-term durability of weight loss with the LSG. A recent review cited %EWL 62.3 %, 53.8 %, 43 %, and 54.8 % at 5, 6, 7, and 8 or more years after LSG, respectively [11]. Multiple other studies have demonstrated %EWL at 5 years to be around 60 %, and in most studies, it was not significantly different than LRYGB [2, 11]. The 5-year results have shown both LSG and LRYGB to each have a sustained effect on medical comorbidities. Most analyses find a slightly more robust improvement in type II diabetes with the LRYGB [9].

Barrett’s esophagus is an intestinal metaplasia of the esophagus and is a major risk factor for the development of esophageal adenocarcinoma. It is a result of long-term exposure of the esophagus to gastric acids. 50–70 % of patients undergoing bariatric surgery have symptoms of gastroesophageal reflux disease (GERD), and a hiatal hernia is present in 15 % [12]. Most studies find continued or even worsening GERD following LSG [1]. In comparison, LRYGB resolves GERD in the majority of cases [13]. Expert consensus is that the presence of severe GERD or Barrett’s esophagus is an absolute contraindication to sleeve gastrectomy [14].