The LAP-BAND System is a long-term implantable medical device designed to induce weight loss in severely obese patients by restricting food consumption. The slip-through buckle design band is designed to ease laparoscopic placement around the stomach and form a small gastric pouch and stoma. No cutting or stapling of the stomach is required and there is no bypassing of portions of the stomach or intestines. The initial pouch and stoma size are determined during surgery and are defined by the use of a calibration tube (pouch size) and pressure sensitive sensor tip (stoma size).
After surgery, the stoma outlet from the small upper stomach pouch to the rest of the stomach can be adjusted percutaneously. The inner surface of the band is inflatable and connected by kink-resistant tubing to a subcutaneous access port. By injecting or withdrawing saline via the access port, the size of the stoma can be decreased or decreased, respectively, enabling weight loss to be adjusted to individual requirements and preferences without the need for additional surgery.
EVOLUTION OF SURGICAL TECHNIQUE:
BioEnterics Corporation requires surgeons to undertake a training course before using the LAP-BAND System and encourages and promotes surgeon dialogue.
Early experience with the LAP-BAND System in Europe led to a modification of the surgical technique resulting in a significant improvement in results (20)(22)(33)(34)(35). Dr. Belachew (22), who pioneered the introduction of the LAP-BAND System, has published the results of his series of 350 LAP-BAND System patients. The results show that the most frequent complication is the post-operative development of a large upper pouch. The mean time of this occurrence was 10.48 months (2-29 months post surgery). Ultimately, Dr. Belachew reported a pouch-related complication rate of 82% in his first 39 patients. Dr. Belachew’s early experience, as well as that of other international surgeons, indicated the reason for late pouch-related complications. Dr. Belachew reported that "Pouch dilatation or stomach slippage was caused by an initially too-large pouch with the posterior wall mobile due to placement of the band within the lesser sac. The anterior wall was partially mobile due to insufficient suturing, and the stoma was relatively tight due to postoperative edema". Starting in 1995, Dr. Belachew and other international surgeons changed their surgical technique to prevent the pouch-related complications.
The modifications to the surgical technique were: reducing the upper stomach pouch to 15cc in volume; creating a retrogastric passage for the band through and within the layers of the phrenogastric ligament above the bursa omentalis (higher on the stomach than previously); placing at least four anterior fundus to fundus sutures over the band; and reducing the amount of saline in the band at surgery (leaving the band and stoma more open).
The result of these changes was a significant improvement in short-term and long-term operative results. Dr. Belachew reported that 36 of his 46 pouch related complications occurred during the years 1993 and 1994 before he modified the surgical technique. After he modified his surgical technique Dr. Belachew reported a significant decrease in pouch-related complications and an overall complication rate of 4.2% (22). Similar results have been reported by Dr. Belva who has presented the results of a collective European study involving 3,800 subjects where the post-operative complication rate requiring re-operation decreased from 18% to 8.9% after adoption of the new surgical technique (36). Dr. O’Brien (20), with a prospective study of 302 LAP-BAND System patients in Australia, reported that the complication rate for pouch enlargement for the first 50 patients in his consecutive study was 30% with this rate falling to 2.5% with the modification of the surgical technique in the last 200 patients.
LEARNING CURVE AND IMPACT ON STUDY RESULTS:
Laparoscopic band placement is an advanced laparoscopic procedure requiring laparoscopic skills of the level comparable to that of a Nissen fundoplication. As with all advanced laparoscopic techniques , there is a learning curve which varies from surgeon to surgeon. As discussed below, publications reporting early results and fewer procedures often note higher complications and less efficacy relative to reports of more extensive and frequent experience.
Dr. De Jong (37) and others (36)(38) have noted the impact of the learning curve on operative results. Dr. De Jong experienced a 30% re-operation rate for his first 50 patients and a significantly reduced 13% re-operation rate for his subsequent 47 patients. Although his complication rate is still high he notes "In our experience there seems to be a learning curve in the laparoscopic gastric banding technique." Also Dr. Elmore in an abstract (39) reported the results of 64 LAP-BAND System patients and noted that the majority of his complications occurred during the "learning curve" period (1-25 patients). For this reason, papers that report the results of smaller studies may report significantly poorer results. Morino et al. have reported "disappointing long term results" after placing 7 ASGB bands and 8 LAP-BAND System bands laparoscopically (40). Also, Angrisani et al. (41) reported a 14.3% post-operative proximal gastric pouch dilatation rate in a small study (n=35) where the initial pouch size was 20mL in the first 5 (14.3%) patients and then reduced to 15mL in the remaining 30 (85.6%) patients. The results of this study may have been adversely affected not only by the small number of subjects, but also by the large pouch created at surgery in 14.3% of the patients.