TYPES OF SURGERY
Operations to assist with weight loss can be broken down loosely into gastric restrictive operations and malabsorptive operations.
In general, malabsorptive operations are more effective than gastric restrictive operations, but carry a high incidence of serious complications and are very rarely performed any longer.
Malabsorptive operations work by bypassing the majority of the small intestine and sometimes the stomach as well. Their basic mechanism of action is to produce continuous diarrhea and inability to absorb food. Unfortunately, though quite effective at producing weight loss, these operations are also recognized to produce metabolic side effects that may be devastating, irreversible, and even fatal. They are seldom performed any longer.
Gastric BypassThis operation works by bypassing the distal stomach, by restricting the size of the gastric reservoir, and by producing undesirable side-effects if sweets, especially sweet liquids, are taken. It is more effective than the Vertical Banded Gastroplasty, but may rarely produce serious long-term metabolic consequences, especially relating to Vitamin B-12 absorption, calcium and iron absorption, and anemia.
This surgery is not a cure for obesity, but a tool to allow you to achieve healthy weight maintenance. Without your effort, this operation may not produce any significant weight loss at all.
LAP - BAND SurgeryThis procedure works by placing a band around the upper most part of the stomach, separating the stomach into one small and one large portion. The band is then adjusted after surgery to either increase or decrease restriction by injecting a port placed underneath your skin on your abdomen.
Unlike the gastric bypass procedure, the lap band can be reversed and digestion and absorption are normal. Despite the lack of malabsorption, we still encourage daily vitamin intake as part of your healthy lifestyle.
Weight loss is slower and less with the lap band. You will lose 50 percent of your excess weight at two years. Potentially, with continued adjustments of the band and better eating and exercise habits, you may lose more weight. Like the gastric bypass, without your effort this operation may not produce any significant weight loss at all. It is possible for most people to eat enough, even with this operation, to maintain their preoperative weight or to regain any weight loss.
It will be critical that you begin and continue an exercise program for the rest of your life. This should be 30 minutes of exercise five to seven days a week. In addition, it is critical that you maintain a diet for the rest of your life that consists of no sweets, very small amounts of carbohydrates, small volumes of food and high protein intake. You will need to eat 40 - 60 grams of protein a day and it will be very important for you to watch food labels to do this.
Laparoscopic SurgeryFor most patients we have been willing to perform these procedures laparoscopically. Using a small video telescope and fine, long instruments approximately the diameter of your little finger, we can perform these procedures with several small punctures of the abdominal wall, rather than a long, upper abdominal incision.
The main advantage of this surgery is that recovery may be faster than with traditional open surgery. It requires no more operative time than the open surgery and it is as safe as the open surgery. There is a 2% chance of requiring a conversion to an open procedure. This would entail an incision from the xiphoid to the belly button. Conversion would only be needed to ensure a safe operation.
Robotic Gastric Bypass SurgeryStanford University Medical Center was the first institution to perform a totally robotic laparoscopic roux-en-y gastric bypass. They first reported their findings in the Archives of Surgery (PDF) and further reports of their experience can be found in Surgery for Obesity and Related Disorders with a summary of our first 75 patients published in Obesity Surgery in June 2006. The Chief of the Division of Bariatric Surgery here at the University of Nevada School of Medicine has trained with those at Stanford in this technique. Dr. Lau has also co-founded the robotic gastric bypass program at the Palo Alto VA while at Stanford for his fellowship training.
The laparoscopic roux-en-y gastric bypass is arguably the most challenging minimally invasive procedure in general surgery. Because the procedure demands advanced laparoscopic skills such as suturing, intracorporeal knot-tying, stapling, two-handed tissue manipulation, and the ability to operate in multiple quadrants of the abdomen, the learning curve for physicians is 75 - 100 cases even for experienced laparoscopic surgeons. Furthermore, limitations in conventional laparoscopic equipment such as two-dimensional visualization, counter-intuitive instrument movement, limited range of motion of the instruments, and surgeon fatigue serve as impediments for surgeons wishing to adopt the laparoscopic approach.
In 2000, the FDA approved the da Vinci® Surgical System (Intuitive Surgical, Inc. Sunnyvale, CA) for applications in general laparoscopic surgery. The “robot” is a telemanipulator instrument that allows the surgeon, from a remote console, to control up to 3 robotic arms and a binocular camera, rendering fine 3-D imaging. The system uses instruments with a total of seven degrees of freedom, including X, Y, Z tip positioning, shaft rotation, wrist pitch (up-down), wrist yaw (left-right) and grip.
Sleeve GastrectomyThe newest weight loss procedure to be provided at the University of Nevada School of Medicine’s Division of Bariatric Surgery is the laparoscopic sleeve gastrectomy. This procedure was first described as the first step of a more complicated procedure, the duodenal switch. Initial weight loss from the sleeve gastrectomy alone was found to be very good (50-60% excess weight loss) at one year without the need for further intervention. The sleeve gastrectomy provides some advantages namely no anastomoses (connections between the bowel), no adjustments as needed with the Lap-Band, and may later be converted to the either the gastric bypass or Lap-Band. The complications appear to be less than the gastric bypass; however, long-term data are lacking for this procedure. The sleeve gastrectomy appears to be a viable option in addition to the Lap Band or gastric bypass for surgical weight loss.