Bariatric Surgery: VTE Risk Lingers

GRAPEVINE, TEX. — The period of increased risk for venous thromboembolic events following bariatric surgery lasts far longer than previously recognized, according to a study of more than 17,000 patients.

Indeed, three-quarters of patients who developed venous thromboembolism (VTE) during the year following bariatric surgery did so after hospital discharge. And while the risk was greatest during the first 30 postoperative days, it's worth emphasizing that more than one-third of all VTEs occurred after that time frame, Dr. Thomas H. Magnuson stated at the annual meeting of the American Society for Metabolic and Bariatric Surgery.

“Since most bariatric surgery patients receive VTE prophylaxis only during the index admission, strategies need to be developed to address the high risk of VTE events occurring after discharge. By identifying and treating high-risk patients, extended prophylaxis with agents such as low-molecular-weight heparin or retrievable inferior vena cava filters may help to minimize the occurrence and impact of these late VTE events,” said Dr. Magnuson of Johns Hopkins University, Baltimore.

In their analysis of eight Blue Cross/Blue Shield insurance claims databases covering seven states, Dr. Magnuson and his associates identified 17,434 patients who had bariatric surgery during 2002–2006. Of those, 63% underwent open gastric bypass, 33% laparoscopic gastric bypass, and 4% laparoscopic adjustable gastric banding.

Within 1 year after surgery, 579 patients experienced VTE, a leading cause of mortality associated with bariatric surgery. The incidence of VTE was 0.88% during the index hospitalization, 2.17% within 30 days post surgery, 2.99% by 6 months, and 3.42% by 12 months. Pulmonary embolism accounted for roughly one-third of VTEs at all time points.

Obesity is a known risk factor for VTE. “Bariatric surgery patients will often have three or four risk factors for VTE and are generally considered to be at high risk,” he noted.

A multivariate analysis identified additional VTE risk factors beyond obesity. Before VTE emerged as the strongest risk factor for VTE within 6 months of bariatric surgery, it was associated with more than a sevenfold increased risk. The second strongest risk factor was age older than 55 years, conferring a greater than twofold increased risk. Other independent risk factors for VTE were male gender, hospital length of stay in excess of 5 days, smoking, and gastric bypass as opposed to laparoscopic adjustable banding.

VTE occurred by 6 months in 0.8% of the laparoscopic adjustable gastric band group, significantly less than the 2.7% rate in those who underwent laparoscopic gastric bypass and the 3.3% rate following open gastric bypass.

The 6-month VTE rate rose from 1% in patients under 24 years to 2.95% in those aged 35–44 years, 3.1% in 45- to 54-year-olds, and 4.7% in those aged 55 years or more.

Dr. George Eid of the University of Pittsburgh said the rate of VTE occurring later than 1 month post surgery in this study was “alarming,” but he wondered whether factors not captured in the administrative database might have contributed to the late cases.

Dr. Magnuson replied that he suspects some of the patients who had VTEs late in the year underwent further surgery, such as body contouring or revisional bariatric procedures. Such information is contained in the billing database, which is still being analyzed.

Dr. Harvey J. Sugerman of Sanibel, Fla., editor in chief of the journal Surgery for Obesity and Related Diseases, commented that the new study raises but cannot answer a number of key questions, including which patients need extended prophylaxis, in what form, and for how long. Answers should be forthcoming from a couple of ongoing prospective major initiatives, including the Bariatric Outcomes Longitudinal Database (BOLD) and the National Institutes of Health-sponsored Longitudinal Assessment of Bariatric Surgery (LABS).

Dr. Magnuson reported having no conflicts of interest in connection with this study.

“Strategies need to be developed to address the high risk of VTE events occurring after discharge,” Dr. Thomas H. Magnuson said.

Source BRUCE JANCIN ELSEVIER GLOBAL MEDICAL NEWS

GRAPEVINE, TEX. — The period of increased risk for venous thromboembolic events following bariatric surgery lasts far longer than previously recognized, according to a study of more than 17,000 patients.

Indeed, three-quarters of patients who developed venous thromboembolism (VTE) during the year following bariatric surgery did so after hospital discharge. And while the risk was greatest during the first 30 postoperative days, it's worth emphasizing that more than one-third of all VTEs occurred after that time frame, Dr. Thomas H. Magnuson stated at the annual meeting of the American Society for Metabolic and Bariatric Surgery.

“Since most bariatric surgery patients receive VTE prophylaxis only during the index admission, strategies need to be developed to address the high risk of VTE events occurring after discharge. By identifying and treating high-risk patients, extended prophylaxis with agents such as low-molecular-weight heparin or retrievable inferior vena cava filters may help to minimize the occurrence and impact of these late VTE events,” said Dr. Magnuson of Johns Hopkins University, Baltimore.

In their analysis of eight Blue Cross/Blue Shield insurance claims databases covering seven states, Dr. Magnuson and his associates identified 17,434 patients who had bariatric surgery during 2002–2006. Of those, 63% underwent open gastric bypass, 33% laparoscopic gastric bypass, and 4% laparoscopic adjustable gastric banding.

Within 1 year after surgery, 579 patients experienced VTE, a leading cause of mortality associated with bariatric surgery. The incidence of VTE was 0.88% during the index hospitalization, 2.17% within 30 days post surgery, 2.99% by 6 months, and 3.42% by 12 months. Pulmonary embolism accounted for roughly one-third of VTEs at all time points.

Obesity is a known risk factor for VTE. “Bariatric surgery patients will often have three or four risk factors for VTE and are generally considered to be at high risk,” he noted.

A multivariate analysis identified additional VTE risk factors beyond obesity. Before VTE emerged as the strongest risk factor for VTE within 6 months of bariatric surgery, it was associated with more than a sevenfold increased risk. The second strongest risk factor was age older than 55 years, conferring a greater than twofold increased risk. Other independent risk factors for VTE were male gender, hospital length of stay in excess of 5 days, smoking, and gastric bypass as opposed to laparoscopic adjustable banding.

VTE occurred by 6 months in 0.8% of the laparoscopic adjustable gastric band group, significantly less than the 2.7% rate in those who underwent laparoscopic gastric bypass and the 3.3% rate following open gastric bypass.

The 6-month VTE rate rose from 1% in patients under 24 years to 2.95% in those aged 35–44 years, 3.1% in 45- to 54-year-olds, and 4.7% in those aged 55 years or more.

Dr. George Eid of the University of Pittsburgh said the rate of VTE occurring later than 1 month post surgery in this study was “alarming,” but he wondered whether factors not captured in the administrative database might have contributed to the late cases.

Dr. Magnuson replied that he suspects some of the patients who had VTEs late in the year underwent further surgery, such as body contouring or revisional bariatric procedures. Such information is contained in the billing database, which is still being analyzed.

Dr. Harvey J. Sugerman of Sanibel, Fla., editor in chief of the journal Surgery for Obesity and Related Diseases, commented that the new study raises but cannot answer a number of key questions, including which patients need extended prophylaxis, in what form, and for how long. Answers should be forthcoming from a couple of ongoing prospective major initiatives, including the Bariatric Outcomes Longitudinal Database (BOLD) and the National Institutes of Health-sponsored Longitudinal Assessment of Bariatric Surgery (LABS).

Dr. Magnuson reported having no conflicts of interest in connection with this study.

“Strategies need to be developed to address the high risk of VTE events occurring after discharge,” Dr. Thomas H. Magnuson said.

Source BRUCE JANCIN ELSEVIER GLOBAL MEDICAL NEWS

GRAPEVINE, TEX. — The period of increased risk for venous thromboembolic events following bariatric surgery lasts far longer than previously recognized, according to a study of more than 17,000 patients.

Indeed, three-quarters of patients who developed venous thromboembolism (VTE) during the year following bariatric surgery did so after hospital discharge. And while the risk was greatest during the first 30 postoperative days, it's worth emphasizing that more than one-third of all VTEs occurred after that time frame, Dr. Thomas H. Magnuson stated at the annual meeting of the American Society for Metabolic and Bariatric Surgery.

“Since most bariatric surgery patients receive VTE prophylaxis only during the index admission, strategies need to be developed to address the high risk of VTE events occurring after discharge. By identifying and treating high-risk patients, extended prophylaxis with agents such as low-molecular-weight heparin or retrievable inferior vena cava filters may help to minimize the occurrence and impact of these late VTE events,” said Dr. Magnuson of Johns Hopkins University, Baltimore.

In their analysis of eight Blue Cross/Blue Shield insurance claims databases covering seven states, Dr. Magnuson and his associates identified 17,434 patients who had bariatric surgery during 2002–2006. Of those, 63% underwent open gastric bypass, 33% laparoscopic gastric bypass, and 4% laparoscopic adjustable gastric banding.

Within 1 year after surgery, 579 patients experienced VTE, a leading cause of mortality associated with bariatric surgery. The incidence of VTE was 0.88% during the index hospitalization, 2.17% within 30 days post surgery, 2.99% by 6 months, and 3.42% by 12 months. Pulmonary embolism accounted for roughly one-third of VTEs at all time points.

Obesity is a known risk factor for VTE. “Bariatric surgery patients will often have three or four risk factors for VTE and are generally considered to be at high risk,” he noted.

A multivariate analysis identified additional VTE risk factors beyond obesity. Before VTE emerged as the strongest risk factor for VTE within 6 months of bariatric surgery, it was associated with more than a sevenfold increased risk. The second strongest risk factor was age older than 55 years, conferring a greater than twofold increased risk. Other independent risk factors for VTE were male gender, hospital length of stay in excess of 5 days, smoking, and gastric bypass as opposed to laparoscopic adjustable banding.

VTE occurred by 6 months in 0.8% of the laparoscopic adjustable gastric band group, significantly less than the 2.7% rate in those who underwent laparoscopic gastric bypass and the 3.3% rate following open gastric bypass.

The 6-month VTE rate rose from 1% in patients under 24 years to 2.95% in those aged 35–44 years, 3.1% in 45- to 54-year-olds, and 4.7% in those aged 55 years or more.

Dr. George Eid of the University of Pittsburgh said the rate of VTE occurring later than 1 month post surgery in this study was “alarming,” but he wondered whether factors not captured in the administrative database might have contributed to the late cases.

Dr. Magnuson replied that he suspects some of the patients who had VTEs late in the year underwent further surgery, such as body contouring or revisional bariatric procedures. Such information is contained in the billing database, which is still being analyzed.

Dr. Harvey J. Sugerman of Sanibel, Fla., editor in chief of the journal Surgery for Obesity and Related Diseases, commented that the new study raises but cannot answer a number of key questions, including which patients need extended prophylaxis, in what form, and for how long. Answers should be forthcoming from a couple of ongoing prospective major initiatives, including the Bariatric Outcomes Longitudinal Database (BOLD) and the National Institutes of Health-sponsored Longitudinal Assessment of Bariatric Surgery (LABS).

Dr. Magnuson reported having no conflicts of interest in connection with this study.

“Strategies need to be developed to address the high risk of VTE events occurring after discharge,” Dr. Thomas H. Magnuson said.

Source BRUCE JANCIN ELSEVIER GLOBAL MEDICAL NEWS