Micronutrient supplementation is advised for all bariatric surgery patients [16, 17], though little has been published on specific postoperative deficiencies in sleeve gastrectomy patients. Consensus guidelines recommend supplementation with a multivitamin, calcium with vitamin D, folic acid, elemental iron, and vitamin B12, with regular monitoring of micronutrient levels postoperatively [12]. Vitamin B12 deficiency is thought to be due to insufficient production of intrinsic factor and inadequate B12 intake, while iron absorption may be affected by alterations in acid production [15]. Thiamine deficiency resulting in Wernicke’s encephalopathy has been described in case reports following sleeve gastrectomy [18] (Table 8.2).

Regular postoperative visits to the surgeon and dietician are designed to recognize complications such as nutritional deficiencies, but also to help eliminate poor dietary choices and avoid weight regain. Visits occur every 3 months for the first year, then annually thereafter. Many bariatric centers host regular seminars for their postoperative patients to encourage good dietary habits.

Weight loss is rapid following surgery. In the bariatric literature, weight goals are measured as the percent of excess weight lost (%EWL) . This measurement takes in to account the starting body weight, current body weight, and ideal body weight. At 12 months postoperatively, average %EWL is between 55 and 75 % [19–21], but has been reported as high as 84.8 % [22]. Peak weight loss is seen between 12 and 24 months (average 18 months) after surgery, with some patients experiencing an increase in weight thereafter. Braghetto et al. reported weight regain in 30 % of patients at 5 years postoperatively, with average %EWL of 57.3 [22]. Bohdjalian found similar results, with 19 % of patients regaining weight and %EWL falling to 55.0 % at 5 years [23]. This was corroborated by a review of the published data by Gagner et al. [24] (Table 8.3).

Weight regain may be a result of dilation of the sleeve over time, which results in less restriction. Patients find that they can eat larger volumes of food several years after surgery. While this may be the natural history of the sleeve gastrectomy, it can likely be prevented by avoiding carbonated liquids and mixing of solids and liquids, both of which stretch the pouch over time. Emphasis should be placed on prevention; however should medical management and counseling fail, surgical revision as a salvage maneuver remains an option. Revision from sleeve gastrectomy to gastric bypass addresses both weight regain and reflux disease [25]. Resizing or narrowing of the sleeve has also been described [26], as well as placement of an adjustable gastric band around the sleeve [27] .

Sleeve gastrectomy has proven to be very effective treatment for obesity-related comorbidities. Most studies report resolution or improvement of diabetes, hypertension, and hyperlipidemia in greater than 60 % of patients at 3–5-year follow-up [20, 22, 28]. Pequignot et al. found that comorbidities continued to improve between years 1 and 2 after surgery, despite no change in %EWL. In multivariate analysis, preoperative elevated systolic blood pressure was the only negative predictive factor for resolution of metabolic syndrome [28]. Studies report resolution of diabetes in 70–100 % of patients [22].