Morbid obesity is a common problem associated with serious medical complications. Various operative procedures have evolved due to poor success in achieving permanent weight loss in these patients with dietary and behavioral therapy. The number and variety of procedures that have been used reflect the creativity and ingenuity of their developers and attest to the variety of problems and complications associated with each of type of operation.
The rationale behind the surgical approach to obesity (bariatric) surgery is to reduce calories available for fat deposition, either through inducing malabsorption by creating a small-bowel shunt (i.e., jejun-oileal bypass) or by calorie deprivation by means of gastric restrictive surgery (i.e., gastric bypass, gastroplasty, bands).
The first surgical therapy for morbid obesity was in the early 1950s when Henriksson treated three patients with resection of a large portion of small bowel, as reported by Linner . Although success was achieved with regard to weight loss, this procedure was not accepted because of its irreversibility. Shortly thereafter, the jejunoileal bypass (JIB) was developed. Various modifications of this operation were made over the next 20 years, with its popularity peaking in the mid-1970s. The general principle is to significantly decrease the amount of functional small bowel by surgically bypassing a large segment of it. Various surgical configurations have been devised to achieve this goal. The radiographic findings will vary depending on which type of operation has been performed. By 1980, however, the JIB had been generally abandoned owing to the development of serious late complications in a fairly high percentage of patients. These included diarrhea, electrolyte disturbances, nephrolithiasis, cholelithiasis, liver abnormalities, and cirrhosis.
Gastric restrictive surgery was introduced in the 1960s by Mason and Ito . This type of surgery evolved because of the observation that patients who had undergone gastric resections for other reasons lost weight. With the advent of automatic stapling devices in the 1970s, these procedures became technically easier to perform and they therefore gained in popularity. The rationale for surgery is that with a small gastric pouch that emptied slowly, satiety would occur quickly and oral intake would therefore decrease. The aim of surgery is to limit gastric capacity and restrict gastric outflow while avoiding the long-term serious complications of the JIB. This operation is more difficult to perform than the JIB, however, and the complication rate in the early postoperative period is higher. Comparative studies have shown that gastric bypass procedures achieve weight loss equal to or greater than the JIB .
With the gastric bypass (GBP) a small-volume (15-30 ml) gastric pouch is created with an outlet or channel to the small bowel of approximately one centimeter. Approximately 90% of the stomach is excluded. The anastomosis may be either a loop gastrojejunostomy or a Roux-en-Y configuration (Figs. 3.64 and 3.65). The Roux-en-Y procedure is technically easier and decreases the incidence of the late complications of bile reflux gastritis and esophagitis . The gastric pouch is created by using a stapling device. Generally two rows of staples are placed adjacent and parallel to each other, extending completely across the stomach so that the distal stomach is functionally excluded from the pouch. Gastric transaction between the staple lines may be performed if desired. It is important to ensure that the pouch is appropriately sized and accommodates volumes of only about 15 to 30 ml. Some surgeons place a temporary decompressive gastrostomy in the distal stomach, which is removed before hospital discharge.
Esophagus Figure 3.66. Horizontal gastroplasty.
Gastroplasty or gastric partition procedures, which create small gastric pouches but without anastomoses, are technically easier to perform than the GBP. Over the years various configurations have been devised. The staples may be placed horizontally or, more commonly currently, vertically. With the horizontal orientation, the channel may be located centrally or along the greater curvature and should measure approximately 1 cm (Figs. 3.66 and 3.67). Reinforcement of the channel is necessary to prevent widening. The vertical banded gastroplasty (VBG) has essentially replaced horizontal stapling because there was a
Figure 3.67. Horizontal gastroplasty. Single-contrast film from an upper GI series shows the horizontally oriented staples and channel to the remainder of the stomach.
high incidence of failure with the horizontal orientation. In the VBG, staple lines are placed parallel to the lesser curvature so that a pouch 2 to 4 cm wide and 8 to 10 cm long is created. The 1cm channel must be reinforced with a Silastic or Marlex ring, which may or may not be radioopaque (Figs. 3.68 and 3.69). Most studies comparing the GBP and gastroplasty have found that GBP is more effective and durable than gastroplasty; GBP is technically more difficult, however, and has a higher perioperative morbidity rate.
Figure 3.69. Vertical banded gastroplasty. Spot film with compression from an upper GI series shows a small gastric pouch with a channel to the remainder of the stomach.
The biliopancreatic bypass is a malabsorption-producing procedure that includes a subtotal gastrectomy with a long-limb Roux-en-Y distal jejunoileostomy. The gastric remnant is approximately 200 to 400 ml, with a gastroenterostomy to a 250 cm Roux-en-Y limb. The biliopan-creatic limb is anastomosed 50 cm from the ileocecal valve, forming a common channel for food and biliopancreatic secretions. A cholecys-tectomy is also performed. This operation has fewer untoward side effects than the JIB.
Gastric banding was developed by Wilkinson about 30 years ago as a simpler alternative to bypass or gastroplasty procedures . In the original operation a prosthetic band is wrapped around the upper stomach, forming a channel between a small proximal pouch and the distal stomach (Fig. 3.70). There are no staple lines or anastomoses. Modifications of the banding technique and the material used have been made over the years. Complications include obstruction and/or narrowing of the channel or too large a channel and pouch dilatation resulting in weight gain.
Figure 3.71. Laparoscopic band.
An adjustable laparoscopic band technique has been developed in which a gastric pouch is created by laparoscopically placing a silicone band with an inflatable cuff around the proximal stomach (Fig. 3.71). A calibration tube is placed transesophageally during surgery to calibrate the size of the pouch and stoma. The cuff is connected to a port, which is implanted in the rectus muscle, and the cuff size can be increased or decreased via the port. The size of the stoma, which can be adjusted by percutaneous injection or withdrawal of saline solution into the port under fluoroscopic control, is determined by the patient's ability to eat and by the weight loss curve. Reported complications include slippage of the band, erosion of the band into the stomach, and migration of the access port [68-70].
The Garren gastric balloon was developed in the early 1980s as a noninvasive alternative to surgical approaches to address obesity . With this procedure a deflated bubble is placed in the stomach via a modified large oral gastric tube and then inflated with room air via an insufflation catheter. The tube and insufflation catheter are removed, leaving
Figure 3.72. Garren gastric bubble with migration to the small bowel. Plain film of the abdomen showing the deflated bubble as air-filled tubular structures in the small bowel.
the inflated bubble floating in the stomach. The principle of this procedure is similar to that of the surgical gastric restrictive procedures, and patients experience decreased appetite and early satiety. The main complication is deflation of the balloon with migration beyond the stomach, and rarely subsequent small-bowel obstruction (Fig. 3.72).
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