Surgery for Severe Obesity
http://www.100md.com
《新英格兰医药杂志》
The epidemic of obesity in the United States has spawned a second epidemic — of bariatric surgery. The number of gastrointestinal surgeries performed annually for severe obesity increased from about 16,000 in the early 1990s to about 103,000 in 2003 (see Figure 1). This increase has been fueled by the increase in the number of people who are extremely obese; the failure of diets, exercise, and medical therapy; and the advent of laparoscopic procedures. Surgeons and hospitals are having difficulty keeping up. The number of practicing surgeons who are members of the American Society for Bariatric Surgery (ASBS) increased from 258 in 1998 to 1070 in 2003.
Figure 1. Estimated Number of Bariatric Operations Performed in the United States, 1992–2003.
Data are from the American Society for Bariatric Surgery.
The growth also reflects publicity in the popular press about the successful, high-profile operations of celebrities such as the singer Carnie Wilson, whose surgery was broadcast live on the Internet in 1999, Al Roker of NBC's Today show, and Randy Jackson of Fox's American Idol. One example of the sort of publicity that fuels business is a recent cover story in People magazine that featured a photograph of a slimmed-down Jackson and the headline "How I Lost 100 Lbs!" Inside the magazine, however, was a story about "when surgery goes wrong," which discussed a patient who died from postoperative complications.
Bariatric surgery is not cosmetic surgery. It is major gastrointestinal surgery performed in extremely large patients whose obesity puts them at risk for complications and death — both from the medical problems associated with obesity and from the surgery itself. There are concerns that the surge in demand for these operations and the potential financial opportunities for physicians and hospitals that perform them are placing some patients at risk. One of these concerns is that some procedures are being performed by surgeons who have had inadequate training — as in the early days of laparoscopic cholecystectomy — and at centers with insufficient experience in the medical, dietary, and social dimensions of the care that is needed both before and after surgery. In Massachusetts, the state Department of Public Health has responded to widely publicized reports of surgery-related deaths by convening an expert panel to review the performance of the operations and to recommend improvements.
There are other issues as well. One is insurance coverage and the high cost of the surgery. Depending on the procedure and the program, the surgery and related care may cost $20,000 to $50,000. Although most of these operations are covered by health insurance, coverage varies depending on the company, the procedure, and the patient's medical situation. Surgery is also being performed more frequently in adolescents with severe coexisting conditions, although these operations account for only a small percentage of all bariatric surgeries. The performance of major gastrointestinal surgery in adolescents raises social, psychological, and developmental issues; some hospitals have specialized programs for younger patients.
For adults, overweight has been defined by a body-mass index (the weight in kilograms divided by the square of the height in meters) of 25 or higher, obesity by an index of 30 or higher, and extreme or "morbid" obesity by an index of 40 or higher.1 A body-mass index of 40 or higher represents at least 100 pounds of overweight for men and 80 pounds for women. In the United States, the age-adjusted prevalence of overweight in adults increased from 55.9 to 64.5 percent between the period from 1988 to 1994 and the period from 1999 to 2000. The prevalence of obesity increased from 22.9 to 30.5 percent; the prevalence of extreme obesity increased from 2.9 to 4.7 percent.1 Among people 12 to 19 years of age, the prevalence of overweight increased from 10.5 to 15.5 percent, according to the Centers for Disease Control and Prevention, which categorizes adolescents only as overweight, not as obese or extremely obese.
According to the Technology Evaluation Center of the Blue Cross and Blue Shield Association, "surgery improves health outcomes for patients with morbid obesity as compared to nonsurgical treatment."2 The most recent National Institutes of Health (NIH) consensus conference about surgery for severe obesity was held 13 years ago, in March 1991.3 It recommended that surgery "be considered only for well-informed and motivated patients in whom the operative risks are acceptable" and after the failure of a nonsurgical program integrating diet, exercise, behavior modification, and psychological support. Potential candidates are patients with a body-mass index that exceeds 40, or with an index greater than 35 and serious coexisting conditions such as severe sleep apnea or other life-threatening cardiopulmonary problems, type 2 diabetes, or joint disease. The panel made "no recommendation for surgery" in children and adolescents because its use in young people had "not been sufficiently studied."
Although there are various bariatric operations, two dominate surgical practice in the United States (see Figure 2). One is gastric bypass, the construction of a proximal gastric pouch whose outlet is a Y-shaped limb of small bowel of varying lengths (Roux-en-Y gastric bypass). The proximal stomach is separated from the remaining part of the stomach with staples. The other is a gastric-banding procedure, in which a band is placed around the stomach near its upper end, creating a small pouch and a restricted passage to the larger remaining part of the stomach. In general, gastric bypass results in more weight loss and is more likely to reverse the medical problems associated with severe obesity, such as diabetes. Vomiting is a common risk associated with both procedures, and patients who have gastric bypass are at greater risk for nutritional deficiencies and the dumping syndrome.
Figure 2. Commonly Used Bariatric Surgical Procedures.
The left panel shows a Roux-en-Y gastric bypass in which a small proximal gastric pouch is connected to a Y-shaped loop of the small bowel. The proximal stomach is separated from the remaining part of the stomach with staples. The right panel shows a gastric banding procedure. The band, which can be adjusted by the infusion of saline, is placed around the stomach near its upper end, creating a small pouch and a restricted passage to the larger remaining part of the stomach. In both procedures, the gastric pouch is generally less than 30 ml in volume.
Minimally invasive techniques have been used in bariatric surgery since 1993; advanced surgical skills are required. Although not all patients are candidates for this approach, laparoscopic surgery can speed recovery and the patient's return to normal activities.4 In 2003, about 56 percent of all bariatric operations were laparoscopic procedures, according to the ASBS. Currently, the most common laparoscopic procedure is gastric bypass, according to Dr. Alan C. Wittgrove, medical director of the Alvarado Center for Surgical Weight Control in San Diego, California, and president of the ASBS. Laparoscopic gastric banding, which is less complex technically, is being used increasingly. In 2001, the Food and Drug Administration approved the Lap-Band adjustable gastric band (Inamed Health), a saline-filled prosthetic device that can be used in the procedure.
The major complications of bariatric surgery include pulmonary embolism, respiratory failure, gastrointestinal leaks from the breakdown of the staple or suture line, stomal obstruction or stenosis, and bleeding. The level of risk is related to the specific procedure and the patient's age, degree of obesity, and other medical conditions; some patients are at greater risk than others. There is no comprehensive registry. Thus, it is difficult to obtain accurate data about the specific rates of serious complications and death that can be anticipated — and that may occur even with excellent care. Postoperative mortality is thought to range from as low as 0.1 percent to as high as 1 to 2 percent. Shifting mortality rates to the low end of this range would have a major effect on the overall safety of the operations.
With the demand for bariatric surgery likely to continue to increase, physicians and health officials face twin challenges. The first is to improve safety. The second is to learn more about the long-term outcome, which approaches are best, the mechanisms through which bariatric surgery results in weight reduction, and the effects on coexisting conditions. Surgeons are being trained through residency programs in general surgery and expanded continuing-education activities. In 2003, the ASBS issued guidelines for granting bariatric-surgery privileges. These include recommendations for proctored cases and the documentation of successful outcomes — 10 cases for open procedures and 15 cases as primary surgeon for laparoscopic procedures — with "an acceptable peri-operative complication rate." Later this year, the Surgical Review Corporation, which has been established by ASBS, will begin a "centers of excellence" program through which hospitals with expertise in the surgery as well as comprehensive programs will be identified. One of the criteria is expected to be an annual volume of at least 125 cases.
The National Institutes of Diabetes and Digestive and Kidney Diseases (NIDDK) has established a clinical research consortium, known as the Longitudinal Assessment of Bariatric Surgery, to answer key questions about the risks and benefits of the operations and their physiological effects. The consortium will receive $15 million in funding over a five-year period; the participating medical centers were selected in September 2003.
Leading bariatric surgeons have tried to persuade the NIH to organize another consensus conference. The NIDDK, however, concluded that the field was not ready, because "there was still a lack of data and many of the same research questions remained unanswered," according to Elizabeth H. Singer, a spokesperson for the institutes. "While we have seen from uncontrolled studies and case series that surgical procedures can produce larger and more sustained weight loss than non-surgical treatment, there has been little systematic research on the basic mechanisms, physiology and outcomes," she said in a written statement. In addition, the Technology Evaluation Center of the Blue Cross and Blue Shield Association has been skeptical about laparoscopic and other newer techniques. In September 2003, the program reported, "There is insufficient evidence to conclude whether these procedures (i.e., laparoscopic gastric bypass, laparoscopic gastric banding, bilio-pancreatic diversion, long-limb gastric bypass) either improve the net health outcome or whether they are as beneficial as current established surgery, open gastric bypass with Roux-en-Y anastomosis."5
As a result of such developments, the ASBS is organizing its own consensus conference, modeled on the approach of NIH conferences. "This is very necessary," Wittgrove, the president of the society, said in an interview. "So much has changed in 13 years." The conference will be held in Washington, D.C., in May of this year.
Because bariatric surgery is increasingly common, there may be more deaths overall, even if the risk associated with each individual procedure decreases. According to Dr. Robert E. Brolin, a New Jersey surgeon and a former president of the ASBS, physicians and the public "have to reconcile the fact that the operation has a real mortality and it will continue to have a real mortality under the best of circumstances. Some of these patients are just profound risks for any kind of surgical intervention for any reason. The sickest ones are the ones who benefit the most, but they are also the highest risk."
References
Flegal KM, Carroll MD, Ogden CL, Johnson CL. Prevalence and trends in obesity among US adults, 1999-2000. JAMA 2002;288:1723-1727.
Blue Cross and Blue Shield Association Technology Evaluation Center. Special report: the relationship between weight loss and changes in morbidity following bariatric surgery for morbid obesity. September 2003. (Accessed February 12, 2004, at http://www.bcbs.com/tec/vol18/18_09.html.)
Consensus Development Conference Panel. Gastrointestinal surgery for severe obesity. Ann Intern Med 1991;115:956-961.
SAGES/ASBS guidelines for laparoscopic and conventional surgical treatment of morbid obesity. Gainesville, Fla.: American Society for Bariatric Surgery, May 2000. (Accessed February 12, 2004, at http://www.asbs.org/html/lab_guidelines.html.)
Blue Cross and Blue Shield Association Technology Evaluation Center. Newer techniques in bariatric surgery for morbid obesity. September 2003. (Accessed February 12, 2004, at http://www.bcbs.com/tec/vol18/18_10.html.)(Robert Steinbrook, M.D.)
Figure 1. Estimated Number of Bariatric Operations Performed in the United States, 1992–2003.
Data are from the American Society for Bariatric Surgery.
The growth also reflects publicity in the popular press about the successful, high-profile operations of celebrities such as the singer Carnie Wilson, whose surgery was broadcast live on the Internet in 1999, Al Roker of NBC's Today show, and Randy Jackson of Fox's American Idol. One example of the sort of publicity that fuels business is a recent cover story in People magazine that featured a photograph of a slimmed-down Jackson and the headline "How I Lost 100 Lbs!" Inside the magazine, however, was a story about "when surgery goes wrong," which discussed a patient who died from postoperative complications.
Bariatric surgery is not cosmetic surgery. It is major gastrointestinal surgery performed in extremely large patients whose obesity puts them at risk for complications and death — both from the medical problems associated with obesity and from the surgery itself. There are concerns that the surge in demand for these operations and the potential financial opportunities for physicians and hospitals that perform them are placing some patients at risk. One of these concerns is that some procedures are being performed by surgeons who have had inadequate training — as in the early days of laparoscopic cholecystectomy — and at centers with insufficient experience in the medical, dietary, and social dimensions of the care that is needed both before and after surgery. In Massachusetts, the state Department of Public Health has responded to widely publicized reports of surgery-related deaths by convening an expert panel to review the performance of the operations and to recommend improvements.
There are other issues as well. One is insurance coverage and the high cost of the surgery. Depending on the procedure and the program, the surgery and related care may cost $20,000 to $50,000. Although most of these operations are covered by health insurance, coverage varies depending on the company, the procedure, and the patient's medical situation. Surgery is also being performed more frequently in adolescents with severe coexisting conditions, although these operations account for only a small percentage of all bariatric surgeries. The performance of major gastrointestinal surgery in adolescents raises social, psychological, and developmental issues; some hospitals have specialized programs for younger patients.
For adults, overweight has been defined by a body-mass index (the weight in kilograms divided by the square of the height in meters) of 25 or higher, obesity by an index of 30 or higher, and extreme or "morbid" obesity by an index of 40 or higher.1 A body-mass index of 40 or higher represents at least 100 pounds of overweight for men and 80 pounds for women. In the United States, the age-adjusted prevalence of overweight in adults increased from 55.9 to 64.5 percent between the period from 1988 to 1994 and the period from 1999 to 2000. The prevalence of obesity increased from 22.9 to 30.5 percent; the prevalence of extreme obesity increased from 2.9 to 4.7 percent.1 Among people 12 to 19 years of age, the prevalence of overweight increased from 10.5 to 15.5 percent, according to the Centers for Disease Control and Prevention, which categorizes adolescents only as overweight, not as obese or extremely obese.
According to the Technology Evaluation Center of the Blue Cross and Blue Shield Association, "surgery improves health outcomes for patients with morbid obesity as compared to nonsurgical treatment."2 The most recent National Institutes of Health (NIH) consensus conference about surgery for severe obesity was held 13 years ago, in March 1991.3 It recommended that surgery "be considered only for well-informed and motivated patients in whom the operative risks are acceptable" and after the failure of a nonsurgical program integrating diet, exercise, behavior modification, and psychological support. Potential candidates are patients with a body-mass index that exceeds 40, or with an index greater than 35 and serious coexisting conditions such as severe sleep apnea or other life-threatening cardiopulmonary problems, type 2 diabetes, or joint disease. The panel made "no recommendation for surgery" in children and adolescents because its use in young people had "not been sufficiently studied."
Although there are various bariatric operations, two dominate surgical practice in the United States (see Figure 2). One is gastric bypass, the construction of a proximal gastric pouch whose outlet is a Y-shaped limb of small bowel of varying lengths (Roux-en-Y gastric bypass). The proximal stomach is separated from the remaining part of the stomach with staples. The other is a gastric-banding procedure, in which a band is placed around the stomach near its upper end, creating a small pouch and a restricted passage to the larger remaining part of the stomach. In general, gastric bypass results in more weight loss and is more likely to reverse the medical problems associated with severe obesity, such as diabetes. Vomiting is a common risk associated with both procedures, and patients who have gastric bypass are at greater risk for nutritional deficiencies and the dumping syndrome.
Figure 2. Commonly Used Bariatric Surgical Procedures.
The left panel shows a Roux-en-Y gastric bypass in which a small proximal gastric pouch is connected to a Y-shaped loop of the small bowel. The proximal stomach is separated from the remaining part of the stomach with staples. The right panel shows a gastric banding procedure. The band, which can be adjusted by the infusion of saline, is placed around the stomach near its upper end, creating a small pouch and a restricted passage to the larger remaining part of the stomach. In both procedures, the gastric pouch is generally less than 30 ml in volume.
Minimally invasive techniques have been used in bariatric surgery since 1993; advanced surgical skills are required. Although not all patients are candidates for this approach, laparoscopic surgery can speed recovery and the patient's return to normal activities.4 In 2003, about 56 percent of all bariatric operations were laparoscopic procedures, according to the ASBS. Currently, the most common laparoscopic procedure is gastric bypass, according to Dr. Alan C. Wittgrove, medical director of the Alvarado Center for Surgical Weight Control in San Diego, California, and president of the ASBS. Laparoscopic gastric banding, which is less complex technically, is being used increasingly. In 2001, the Food and Drug Administration approved the Lap-Band adjustable gastric band (Inamed Health), a saline-filled prosthetic device that can be used in the procedure.
The major complications of bariatric surgery include pulmonary embolism, respiratory failure, gastrointestinal leaks from the breakdown of the staple or suture line, stomal obstruction or stenosis, and bleeding. The level of risk is related to the specific procedure and the patient's age, degree of obesity, and other medical conditions; some patients are at greater risk than others. There is no comprehensive registry. Thus, it is difficult to obtain accurate data about the specific rates of serious complications and death that can be anticipated — and that may occur even with excellent care. Postoperative mortality is thought to range from as low as 0.1 percent to as high as 1 to 2 percent. Shifting mortality rates to the low end of this range would have a major effect on the overall safety of the operations.
With the demand for bariatric surgery likely to continue to increase, physicians and health officials face twin challenges. The first is to improve safety. The second is to learn more about the long-term outcome, which approaches are best, the mechanisms through which bariatric surgery results in weight reduction, and the effects on coexisting conditions. Surgeons are being trained through residency programs in general surgery and expanded continuing-education activities. In 2003, the ASBS issued guidelines for granting bariatric-surgery privileges. These include recommendations for proctored cases and the documentation of successful outcomes — 10 cases for open procedures and 15 cases as primary surgeon for laparoscopic procedures — with "an acceptable peri-operative complication rate." Later this year, the Surgical Review Corporation, which has been established by ASBS, will begin a "centers of excellence" program through which hospitals with expertise in the surgery as well as comprehensive programs will be identified. One of the criteria is expected to be an annual volume of at least 125 cases.
The National Institutes of Diabetes and Digestive and Kidney Diseases (NIDDK) has established a clinical research consortium, known as the Longitudinal Assessment of Bariatric Surgery, to answer key questions about the risks and benefits of the operations and their physiological effects. The consortium will receive $15 million in funding over a five-year period; the participating medical centers were selected in September 2003.
Leading bariatric surgeons have tried to persuade the NIH to organize another consensus conference. The NIDDK, however, concluded that the field was not ready, because "there was still a lack of data and many of the same research questions remained unanswered," according to Elizabeth H. Singer, a spokesperson for the institutes. "While we have seen from uncontrolled studies and case series that surgical procedures can produce larger and more sustained weight loss than non-surgical treatment, there has been little systematic research on the basic mechanisms, physiology and outcomes," she said in a written statement. In addition, the Technology Evaluation Center of the Blue Cross and Blue Shield Association has been skeptical about laparoscopic and other newer techniques. In September 2003, the program reported, "There is insufficient evidence to conclude whether these procedures (i.e., laparoscopic gastric bypass, laparoscopic gastric banding, bilio-pancreatic diversion, long-limb gastric bypass) either improve the net health outcome or whether they are as beneficial as current established surgery, open gastric bypass with Roux-en-Y anastomosis."5
As a result of such developments, the ASBS is organizing its own consensus conference, modeled on the approach of NIH conferences. "This is very necessary," Wittgrove, the president of the society, said in an interview. "So much has changed in 13 years." The conference will be held in Washington, D.C., in May of this year.
Because bariatric surgery is increasingly common, there may be more deaths overall, even if the risk associated with each individual procedure decreases. According to Dr. Robert E. Brolin, a New Jersey surgeon and a former president of the ASBS, physicians and the public "have to reconcile the fact that the operation has a real mortality and it will continue to have a real mortality under the best of circumstances. Some of these patients are just profound risks for any kind of surgical intervention for any reason. The sickest ones are the ones who benefit the most, but they are also the highest risk."
References
Flegal KM, Carroll MD, Ogden CL, Johnson CL. Prevalence and trends in obesity among US adults, 1999-2000. JAMA 2002;288:1723-1727.
Blue Cross and Blue Shield Association Technology Evaluation Center. Special report: the relationship between weight loss and changes in morbidity following bariatric surgery for morbid obesity. September 2003. (Accessed February 12, 2004, at http://www.bcbs.com/tec/vol18/18_09.html.)
Consensus Development Conference Panel. Gastrointestinal surgery for severe obesity. Ann Intern Med 1991;115:956-961.
SAGES/ASBS guidelines for laparoscopic and conventional surgical treatment of morbid obesity. Gainesville, Fla.: American Society for Bariatric Surgery, May 2000. (Accessed February 12, 2004, at http://www.asbs.org/html/lab_guidelines.html.)
Blue Cross and Blue Shield Association Technology Evaluation Center. Newer techniques in bariatric surgery for morbid obesity. September 2003. (Accessed February 12, 2004, at http://www.bcbs.com/tec/vol18/18_10.html.)(Robert Steinbrook, M.D.)