Laparoscopic Adjustable Gastric Banding Surgery

Introduction

In the 1980s, gastroplasty was the most common restrictive bariatric procedure, with the most commonly performed iteration being the vertical banded gastroplasty. However, due to poor long-term weight loss and a high rate of late complications, alternatives to this operation were sought. Open gastric banding procedures inspired laparoscopic AGB, first described in 1993, which involves the placement of a restrictive inflatable balloon device around the gastric cardia, approximately 1 cm below the gastroesophageal junction. This balloon is connected by tubing to a subcutaneous port which is attached to the rectus sheath. Saline injected into the port will cause balloon inflation which results in narrowing of the stomach at the level of the balloon. Various brands of laparoscopic AGB exist, though only the LAP-BAND system and the REALIZE adjustable gastric band (Ethicon Endosurgery, Cincinnati, OH) currently have Food and Drug Administration (FDA) approval for use in the USA. The equivalence between the two FDA-approved devices in the USA has been demonstrated, but comparative trials with others devices do not yet exist.

Technical considerations

The laparoscopic AGB is best placed via a pars flaccida approach, that is, via a retrogastric tunnel between the pars flaccida medially and the angle of His laterally. This has equivalent efficacy to the initially described perigastric approach, but has a significantly decreased rate of band slippage (i.e., gastric prolapse). The pars flaccida approach results in more extraneous tissue, particularly the lesser curvature fat pad, being incorporated into the band. Compensation by placing a band of greater diameter may be required to limit stomal obstruction. At the time of placement, a peroral calibration balloon may be placed into the stomach, filled with 15-25 cc of saline, allowing the band is to be fastened below this level. A 15-25 cc pouch is thereby created. AGB avoids the risks of gastrointestinal stapling and anastomosis and allows complete reversibility. Most authors agree laparoscopic AGB is less technically demanding and less morbid than laparoscopic RGB. However, potential disadvantages of laparoscopic AGB compared to laparoscopic RGB include the ongoing need for band adjustments, delayed or unsatisfactory weight loss, and unique indications for reoperation such as pouch dilation, esophageal dilation, band slippage, band erosion, port-site complications, or leaks from the device.

Outcomes

Laparoscopic AGB has been compared to intensive pharmacotherapy, behavioral modification, diet modification, and exercise in patients with BMI 30-35 kg/m2. In this population, laparoscopic AGB was seen to be more effective in reducing weight, resolving metabolic derangements, and improving quality of life. Laparoscopic AGB is very effective at producing weight loss, with patients losing approximately 50% of their excess body weight. This weight loss occurs in a gradual manner, with approximately 35% EBWL by 6 months, 40% by 12 months, and 50% by 24 months. This percentage appears to remain stable after 3-8 years based on the few studies providing this length of follow-up. However, as many as 25% of laparoscopic AGB patients fail to lose 50% of their excess body weight by 5 years. Laparoscopic AGB has positive effects on the comorbidities of obesity. Type 2 diabetes is improved in about 90% of patients, due to increased insulin sensitivity and increased pancreatic beta-cell function, and diabetic medications are eliminated in 64%. Following AGB, resolution of type 2 diabetes mirrors weight loss, and therefore is slower to occur than after RGB or BPD where the diabetes is seen to begin to improve before significant weight loss. Symptoms of gastroesophageal reflux disease may be eliminated in at least 89% at 12 months, even in patients with large hiatal hernias, but with the side-effect of impaired lower esophageal sphincter relaxation and possible altered esophageal motility. Rate of obstructive sleep apnea drops from 33% to 2% in laparoscopic AGB patients. Major quality-of-life improvements are seen after AGB placement, with all subscales of the SF-36 general quality-of-life questionnaire significantly improved, particularly in areas of bodily pain, general health perception, and mental health perception. The short-term (< 12 months) weight loss of laparoscopic AGB is inferior to RGB. This discrepancy is seen to continue, with a randomized controlled trial illustrating that EBWL at 5 years was 47.5% for AGB versus 66.6% for RGB. Still, life-threatening complications are less frequent in laparoscopic AGB as compared to laparoscopic RGB.

Postoperative

Successful weight loss after laparoscopic AGB requires close follow-up for band adjustments, education, and support. In the absence of comparative data, guidelines for follow-up and adjustment are based on manufacturer recommendations and expert opinion. Physicians with extensive experience placing and managing the AGB adhere to a number of basic tenets necessary for successful weight loss. Immediately after operation, oral intake is restricted to liquids and soft foods to prevent vomiting and dislodgment of the band. After a recovery period, the diet is transitioned to solid foods that induce satiety and no-calorie liquids between meals. Eventually, a wide range of foods is tolerated, though whole meats and heavy breads may always cause dysphagia or regurgitation. To avoid protein-calorie malnutrition and loss of lean body mass, diets should focus on protein and complex carbohydrate intake, with a limited quantity of simple sugars and fats. Physical activity is recommended to maintain lean body mass and to improve cardiovascular fitness and total weight loss. In the initial postoperative period, most advocate leaving the band unfilled. The first adjustment usually occurs about 6 weeks after placement with initial and subsequent fill volumes determined by band type and patient factors. Fluid should be added if weight loss falls below expectations, or if meal volumes increase with loss of satiety. Adjustment is not needed if there is adequate weight loss, satiety, and tolerance. Fluid should be removed for vomiting, coughing, choking, or significant solid food intolerance. Bands may be adjusted with or without radiographic guidance with acceptable results.

Complications

Case series and systematic reviews put early mortality rates after laparoscopic AGB at 0.05-0.4%, compared with laparoscopic RGB at 0.5-1.1%, open RGB at 0.5-1.0%, open BPD at 1.1%, and laparoscopic BPD at 2.5-7.6%. Regarding relative morbidity rates, comparative data are few. Overall complications and major complications are less common in laparoscopic AGB than laparoscopic RGB or laparoscopic BPD, in a single-center experience.

Mortality/ morbidity after laparoscopic bariatric procedures

Recent review of a multicenter, prospective US trial of laparoscopic AGB placement by the perigastric approach found uncommon occurrence of gastrointestinal perforation (1%) or other visceral injury (1%). Band-related complications accumulated over 5-year follow-up, such as slippage/ pouch dilatation (24%), esophageal dilatation (8%) and stomal obstruction (14%). Port-site complications, including pain, port displacement, and leak, arose in about 7% of patients. Mean explantation or major revision rate by 9 years was 33%. In contrast, parallel review of a subsequent trial which implemented the pars flaccida technique found reduced slippage/ pouch dilatation (7%), esophageal dilatation (1%), and stomal obstruction (2%) at 1-year. Non-US surgeons have also championed the pars flaccida method to reduce band-specific complications. One pure pars flaccida series with 7-year follow-up reported 12% slippage/ pouch dilatation, however the cumulative reoperation rate was 32%.