Laparoscopic Roux-en-Y Gastric Bypass Surgery

Introduction

Gastric bypass was first developed in the 1960s as a means to combine restrictive, malabsorptive, and behavioral components to achieve weight loss. Physiologic changes in the gastrointestinal tract after gastric bypass (dumping, neuroendocrine responses, etc.) also appear to influence weight loss and comorbidity improvements which may precede weight loss. Since then, modifications have included use of a small lesser curvature-based gastric pouch, gastric transection, Roux-en-Y reconstruction, and variations in length of the alimentary limb. Feasibility of the laparoscopic approach to RGB was first shown in the early 1990s.

Technical considerations

The stomach is divided to form a small proximal gastric pouch and the small intestine is reconstructed using a Roux-en-Y to form an alimentary limb. Although accurate measurement of pouch volume is difficult and prospective data are lacking, a retrospective study has suggested that smaller pouches may be associated with greater weight loss. Most surgeons choose the transection point by measuring from the esophagogastric junction or by counting vascular arcades. When creating the Roux en-Y bypass, the jejunum is typically divided below the ligament of Treitz, and the distal segment is elevated and surgically connected to the gastric pouch to create the alimentary (Roux) limb, with variations on the path and method for anastomosis. The proximal bowel segment, also called the biliopancreatic limb, is usually connected to the alimentary limb 75- 150 cm distal to the gastrojejunostomy. This reconstruction serves to bypass the distal stomach, duodenum and a portion of jejunum to create malabsorption. Several authors have addressed the issue of limb length during RGB. In BMI 50 kg/m2 patients, both retrospective and prospective data fail to show a benefit for alimentary limbs longer than 150 cm. However, BMI >50 kg/m2 patients who were randomized to a 250 cm rather than a 150 cm alimentary limb did show improved weight loss at 18 months, though the study was not powered to confirm this benefit at longer follow-up. Other studies have examined the use of alimentary limbs longer than 300 cm for BMI > 50 kg/m2 patients, and have found improved weight loss over standard RGB, but with increased nutritional deficiencies and need for reoperation. Laparoscopic RGB is a technically demanding procedure; the available literature suggests an experience of 50-150 cases is required for surgeons to become safe and proficient.

Outcomes

The literature comparing laparoscopic RGB to open RGB and to contemporary medical and surgical treatments for obesity includes several prospective randomized controlled trials, a large prospective case-controlled cohort study, numerous case series, and four metaanalyses. Surgical therapy is clearly more effective than medical therapy in terms of weight loss and resolution of comorbidities. Morbidly obese patients employing behavioral and medical therapies alone actually gain weight in the long term. Surgical patients have lower 5 year mortality versus nonsurgical patients (0.68% versus 6.17%), despite 0.4% perioperative mortality. Patients who undergo laparoscopic RGB typically experience 60-70% EBWL, with >75% control of comorbidities. In general, these outcomes are better than banding procedures, which have 45-50% EBWL and less predictable improvement of comorbidities, but are less than BPD ± DS which has 70-80% EBWL with excellent control of comorbidities. Open and laparoscopic RGB have similar efficacy. In prospective randomized trials, there are no significant differences in weight loss up to 3 years follow-up. Similar results have been reported in cases series.

Postoperative

Close, long-term follow-up is recommended for patients after bariatric surgery. A typical example for recommendations of follow-up after laparoscopic RGB would be at 1-3 weeks, followed by quarterly visits during the first year and annually thereafter, to assess weight loss, resolution of comorbidities, long-term complications, and need for continuing education and support. Patients are counseled to eat small, frequent meals of high protein and low carbohydrate content. They should take long-term vitamin supplements (multivitamins, Vitamin B12, and calcium with some patients requiring iron supplementation) and undergo periodic blood testing to identify and treat deficiencies early. Patients should be encouraged to develop regular exercise practices. Two retrospective studies on the impact of follow-up on outcomes after laparoscopic RGB have been done; one suggests patient follow-up does not play an important role while the other reports improved weight loss in patients compliant with follow-up at 1 year.

Complications

The mortality rate after RGB ranges from 0.3% in case series to 1.0% in controlled trials, and the rate of preventable and nonpreventable adverse surgical events is 18.7%. The mortality rate in a review of selected laparoscopic RGB series ranged from 0.5% to 1.1%. Safety of laparoscopic RGB has been compared to open RGB, with laparoscopic patients having reduced incidence of iatrogenic splenectomy, wound infection, incisional hernia and perioperative mortality, but higher rates of bowel obstruction, intestinal hemorrhage, and stomal stenoses. The most frequently reported perioperative complications associated with laparoscopic RGB are wound infection (2.98%), anastomotic leak (2.05%), gastrointestinal tract hemorrhage (1.93%), bowel obstruction (1.73%), and pulmonary embolus (0.41%), while the most frequently reported late complications are stomal stenosis (4.73%), bowel obstruction (3.15%), and incisional hernia (0.47%).