Surgery is more effective than nonsurgical treatment for weight loss and control of some comorbid conditions in patients with a BMI of 40 kg/m2 or greater. More data are needed to determine the efficacy of surgery relative to nonsurgical therapy for less severely obese people. Procedures differ in efficacy and incidence of complications.
IMPORTANCE
Bariatric surgery is an accepted treatment for obesity. Despite extensive literature, few studies report long-term follow-up in cohorts with adequate retention rates.
OBJECTIVE
To assess the quality of evidence and treatment effectiveness 2 years after bariatric procedures for weight loss, type 2 diabetes, hypertension, and hyperlipidemia in severely obese adults.
EVIDENCE REVIEW
MEDLINE and Cochrane databases were searched from 1946 through May 15, 2014. Search terms included bariatric surgery, individual bariatric procedures, and obesity. Studies were included if they described outcomes for gastric bypass, gastric band, or sleeve gastrectomy performed on patients with a body mass index of 35 or greater, had more than 2 years of outcome information, and had follow-up measures for at least 80% of the initial cohort. Two investigators reviewed each study and a third resolved study inclusion disagreements.
FINDINGS
Of 7371 clinical studies reviewed, 29 studies (0.4%, 7971 patients) met inclusion criteria. All gastric bypass studies (6 prospective cohorts, 5 retrospective cohorts) and sleeve gastrectomy studies (2 retrospective cohorts) had 95% confidence intervals for the reported mean, median, or both exceeding 50% excess weight loss. This amount of excess weight loss occurred in 31% of gastric band studies (9 prospective cohorts, 5 retrospective cohorts). The mean sample-size–weighted percentage of excess weight loss for gastric bypass was 65.7% (n = 3544) vs 45.0% (n = 4109) for gastric band. Nine studies measured comorbidity improvement. For type 2 diabetes (glycated hemoglobin <6.5% without medication), sample-size–weighted remission rates were 66.7% for gastric bypass (n = 428) and 28.6% for gastric band (n = 96). For hypertension (blood pressure <140/90 mm Hg without medication), remission rates were 38.2% for gastric bypass (n = 808) and 17.4% for gastric band (n = 247). For hyperlipidemia (cholesterol <200 mg/dL, high-density lipoprotein >40 mg/dL, low-density lipoprotein <160 mg/dL, and triglycerides <200 mg/dL), remission rates were 60.4% for gastric bypass (n = 477) and 22.7% for gastric band (n = 97).
CONCLUSIONS AND RELEVANCE
Very few bariatric surgery studies report long-term results with sufficient patient follow-up to minimize biased results. Gastric bypass has better outcomes than gastric band procedures for long-term weight loss, type 2 diabetes control and remission, hypertension, and hyperlipidemia. Insufficient evidence exists regarding long-term outcomes for gastric sleeve resections.
Bariatric surgery is not a guarantee of successful weight loss and maintenance. Increasingly, patients regain weight, especially those undergoing restrictive surgeries such as laparoscopic banding rather than malabsorptive surgeries such as Roux-en-Y bypass. Active nutritional patient education and clinical management to prevent and detect nutritional deficiencies are recommended for all patients undergoing bariatric surgery. Management of potential nutritional deficiencies is particularly important for patients undergoing malabsorptive procedures, and strategies should be employed to compensate for food intolerance in patients who have had a malabsorptive procedure to reduce the risk for clinically important nutritional deficiencies. To enhance the transition to life after bariatric surgery and to prevent weight regain and nutritional complications, all patients should receive care from a multidisciplinary team including an experienced primary care physician, endocrinologist, or gastroenterologist and consider enrolling postoperatively in a comprehensive program for nutrition and lifestyle management. Future research should address the effectiveness of intensive postoperative nutritional and endocrine care in reducing morbidity and mortality from obesity-associated chronic diseases.
Postoperative ileus follows any operation. Although worsened if the peritoneum is entered, the length and duration of surgery does not influence the severity of postoperative ileus. Inhibitory alpha 2-adrenergic reflexes with peptidergic afferents contribute to postoperative ileus. Clinically, treatment of ileus centers around symptomatic relief with nasogastric suction. Trials of adrenergic blockade combined with cholinergic stimulation have met with limited success. Prokinetic drugs have not been proved effective in the treatment of this disorder. Two types of ileus exist: postoperative and paralytic. Postoperative ileus resolves spontaneously after two to three days, and probably reflects inhibition of colonic motility. Paralytic ileus is more severe, last more than three days, and seems to represent inhibition of small bowel activity. No discrete structural changes cause postoperative ileus and the role of peptidergic neuronal systems of the enteric nervous system has not been elucidated. Possible central or humoral mechanisms have not been studied extensively. The possible direct inhibition of enteric or spinal nerves by anesthetic agents not cleared from these tissues remains to be studied. Also in need of study is the potential alteration of neurotransmitter receptor activity within the enteric nervous plexus after manipulation of the bowel.
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