Brief History and Summary of Bariatric Surgery

Chapter 3.

GASTRIC BYPASS

Drs. Mason and Ito initially developed this procedure in the 1960s. The gastric bypass was based on the weight loss observed among patients undergoing partial stomach removal for ulcers. Over several decades, the gastric bypass has been modified into its current form, using a Roux-en-Y limb of intestine (RYGBP). The RYGBP is the most commonly performed operation for weight loss in the United States. In the U.S, approximately 140,000 gastric bypass procedures will be performed in 2005, far outnumbering the LAP-BAND®, duodenal switch, and vertical banded gastroplasty procedures.

Initially the operation was performed as a loop bypass with a much larger stomach. Because of bile reflux that occurred with the loop configuration, the operation is now performed as a “Roux-en-Y” with a limb of intestine connected to a very small stomach pouch which prevents the bile from entering the upper part of the stomach and esophagus.

The remaining stomach and first segment of small intestine are bypassed. In the standard RYGBP, the amount of intestine bypassed is not enough to create malabsorption of protein or other macronutrients. However, because the bypassed portion of intestine is where the majority of calcium and iron absorption takes place, anemia and osteoporosis are the most common long-term complications of the RYGBP. Therefore, lifelong mineral supplementation is mandatory. Other clinically important deficiencies that may occur include deficiencies of Vitamin B 1 (thiamine) and Vitamin B 12. Lifelong follow-up with a bariatric program and daily multi-vitamins are strongly recommended prevent nutritional complications.

The RYGBP has been proven in numerous studies to result in durable weight loss and an improvement in weight-related medical illnesses. Half of the weight loss often occurs during the first six months after surgery; weight loss usually peaks at 18-24 months. The obesity-related comorbidities that may be improved or cured with the RYGBP include diabetes mellitus of the adult onset type (so-called insulin resistant), hypertension, high cholesterol, arthritis, venous stasis disease, bladder incontinence, liver disease, certain types of headaches, heartburn, sleep apnea and many other disorders. Furthermore, the RYGBP has resulted in marked improvements in quality of life.

Although the most commonly performed RYGBP (sometimes called the proximal gastric bypass) involves little malabsorption, some surgeons modify the RYGBP to incorporate an element of malabsorption for the purpose of augmenting weight loss in special circumstances. This modification is sometimes called a distal gastric bypass, which may result in more severe nutritional complications than the proximal RYGBP . Whether long-term weight loss is superior to the proximal RYGBP or whether the malabsorptive complications are worth the possible improvements in weight loss has not been well established . Many surgeons reserve the distal RYGBP for very select circumstances.

The mechanism in which the RYGBP works is complex. After surgery, patients often experience marked changes in their behavior. Most patients have a reduction in hunger and feel full sooner after eating. Patients often state that they enjoy healthy foods and lose many of their improper food cravings. Rarely do people feel deprived of food. These complex behavioral changes are partially due to alterations in several hormones (ghrelin, GIP, GLP, PYY) and neural signals produced in the GI tract that communicate with the hunger centers in the brain. Another mechanism for weight loss after the RYGBP is referred to as the dumping syndrome. Dumping may result in lightheadedness, flushing, heart palpitations, diarrhea and other symptoms early (within 10 to 30 minutes) after eating sweets or foods with a high concentration of sugar. Some people remain extremely sensitive to sweets for the rest of their lives; most patients lose some or all of their sweets sensitivity over time.

The risk of dying in the first month after a RYGBP from complications of the operation is about 0.2 to 0.5% in expert centers. Studies have demonstrated that the mortality rate from hospitals with a low experience with the procedure is far higher than that reported by expert centers. The American Society of Bariatric Surgeons fully supports the initiative of the Surgical Review Committee to establish rigid criteria to certify that hospitals with quality programs will be designated as a “Center of Excellence.”

Advantages of RYGBP:

Better weight loss than after purely restrictive procedures
Low incidence of protein-calorie malnutrition and diarrhea
Rapid improvement or resolution of weight-related comorbidities
Appetite reduction

Complications of RYGBP:

Early:
Anastomotic Leak
Pulmonary embolism
Wound infection
Gastrointestinal hemorrhage
Respiratory insufficiency
Mortality
Late:
Incisional hernia
Bowel obstruction
Internal hernia
Stomal stenosis
Micronutrient deficiencies
Marginal ulcer

LAPAROSCOPIC GASTRIC BYPASS

Although the open RYGBP can be performed with a relatively low morbidity and mortality, the wound-related complications such as infection and incisional hernia can be troublesome. Wound infection occurs in as many as 8% of patients after open RYGBP and late incisional hernia occurs in as many as 20% of patients. However, some surgeons have reported a much lower rate. The laparoscopic approach to RYGBP was initiated in an effort to improve the early outcomes including a reduction in postoperative complications arising from a large incision in a severely obese patient.

In 1994, Drs. Wittgrove and Clark reported the first case series of laparoscopic RYGBP. The primary differences between laparoscopic and open RYGBP are the method of access and method of exposure. Laparoscopic RYGBP is normally performed through 5-6 small abdominal incisions (0.5-2.0 cm), the peritoneal cavity (abdomen) is insufflated with carbon dioxide gas which creates a space within which to work, allowing exposure of the operative field (Figure 1a). In contrast, open RYGBP is performed through a larger incision and abdominal wall retractors are used for exposure (Figure 1b). By reducing the size of the surgical incision and the trauma associated with the operative exposure, the surgical insult has been shown to be less after laparoscopic compared to open RYGBP. However, not all patients are candidates for a laparoscopic approach based on body habitus, previous intra-abdominal surgery, etc.

Figure 1a. Figure 1b.

Clinical studies have demonstrated that laparoscopic RYGBP is a safe and effective alternative to open RYGBP for the treatment of morbid obesity. Higa and colleagues reported the largest laparoscopic RYGBP experience with 1,500 operations. There have been three prospective, randomized trials comparing the outcomes of laparoscopic vs open RYGBP. The largest trial was reported by Nguyen and colleagues in 2001. In 2004, a group from Murcia, Spain published their results. Long-term weight loss after laparoscopic and open RYGBP should not differ, as the primary differences between the two techniques is largely in the method of access and not the gastrointestinal reconstruction.

Despite the advantages of the laparoscopic approach, open bariatric surgery still plays a prominent role in management of morbidly obese patients. Relative contraindications for laparoscopic bariatric surgery include patients with extremely high body mass index, patients with multiple previous upper abdominal surgeries, and patients with prior bariatric surgery. Another limitation of the laparoscopic approach is the steep learning curve of this technically challenging procedure for the surgeon, so it is not an operation for the surgeon who has not been trained specifically in this technique. The advantages and disadvantages of laparoscopic RYGBP are listed below.

Advantages of laparoscopic compared to open RYGBP

Lesser intraoperative blood loss
Shorter hospitalization
Reduced postoperative pain
Less pulmonary complications (atelectasis)
Faster recovery
Better cosmesis
Fewer wound complications (incisional hernias and infections)

Disadvantages of laparoscopic compared to open RYGBP

Complex laparoscopic operation associated with a steep learning curve
Possible increase in the rate of internal hernia

SILASTIC ® RING GASTRIC BYPASS

The Silastic® ring gastric bypass is a banded pouch RYGBP. A Silastic® ring is placed around the vertically constructed gastric pouch above the anastomosis between the pouch and intestinal Roux limb. The band controls stoma size by prevention of dilatation of the gastric pouch outlet, and is thought to provide better long-term control of the rate of emptying of the pouch and caloric intake. This procedure also includes placement of a gastrostomy tube for decompression of the distal stomach; a radio-opaque ring marker may be placed around the gastrostomy site to facilitate future percutaneous access to the distal stomach. A small percentage (3%) of patients may have band erosion or obstruction, necessitating reoperations and band removal.

REFERENCES

Gastric bypass

Mason, EE and Ito C. Gastric bypass in obesity. Surg Clin North Am 1967;47:1345-51.

MacDonald KG Jr, Long SD, Swanson MS,et al. The gastric bypass operation reduces the progression and mortality of non-insulin-dependent diabetes mellitus. J Gastrointest Surg 1997;1:213-220.

Sugerman HJ, Starkey JV, Birkenhauer R. A randomized prospective trial of gastric bypass versus vertical banded gastroplasty for morbid obesity and their effects on sweets versus non-sweets eaters. Ann Surg 1987;205:613-24.

Wittgrove AC, Clark GW, Tremblay LJ. Laparoscopic gastric bypass, Roux-en-Y: preliminary report of five cases. Obes Surg 4:353-357, 1994.

Higa KD, Ho T, Boone KB. Laparoscopic Roux-en-Y gastric bypass: technique and 3-year follow-up. J Laparoendosc Adv Surg Tech 2001;11:377-382.

Nguyen NT, Goldman C, Rosenquist CJ, et al: Laparoscopic versus open gastric bypass: a randomized study of outcomes, quality of life, and costs. Ann Surg 2001;234:279-289.

Lugan JA, Frutos D, Hernandez Q, et al. Laparoscopic versus open gastric bypass in the treatment of morbid obesity: a randomized prospective study. 2004;239:433-437.

Podnos YD, Jimenez JC, Wilson SE, Stevens M, Nguyen NT. Complications after laparoscopic gastric bypass. Arch Surg 2003;138:957-961.

Banded gastric bypass

Fobi MAL, Lee H, Holness R, Cabinda D. Gastric bypass operation for obesity. World J Surg 1998;22:925-935.

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TABLE OF CONTENTS

• Chapter 1. INTRODUCTION

• Chapter 2. JEJUNOILEAL BYPASS

• Chapter 3. GASTRIC BYPASS & LAPAROSCOPIC GASTRIC BYPASS

• Chapter 4. BILIOPANCREATIC DIVERSION DUODENAL SWITCH

• Chapter 5. GASTROPLASTY

• Chapter 6. GASTRIC BANDING & LAPAROSCOPIC ADJUSTABLE GASTRIC BANDING

• Chapter 7. ON THE HORIZON & SUMMARY

• References

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