ORLANDO — Superobese males and patients with anastomotic leak have a fourfold increased risk of pulmonary embolism after gastric bypass surgery, according to a study presented at the annual meeting of the American Society for Bariatric Surgery.
Pulmonary embolism (PE) remains a leading cause of death following gastric bypass surgery, occurring with a 1% incidence in these patients (Arch. Surg. 2003;138:957–61). Extending prophylaxis after discharge, including the use of prophylactic inferior vena cava (IVC) filters, is gaining wide acceptance for high-risk patients, Dr. Fadi Abou-Nukta said.
Dr. Abou-Nukta and his associates studied 1,225 patients who had open Roux-en-Y gastric bypass at the Hospital of Saint Raphael in New Haven, Conn. All procedures were performed between 1998 and 2003. A total of 78% of these morbidly obese participants were female. Age and body mass index (BMI) for the morbidly obese group were compared with those of a randomly selected group of open gastric bypass patients.
The researchers diagnosed PE using computed tomography, ventilation-perfusion scanning, or autopsy. There were 11 patients with a PE, 6 male (2.3% incidence) and 5 female (0.5% incidence).
Prophylaxis consisted of heparin 5,000 IU, which was administered preoperatively, and intermittent use of pneumatic compression stockings in the operating room. Patients received enoxaparin (Lovenox) 40 mg, every 12 hours, until discharge, and early postoperative ambulation was encouraged.
Nine of the 11 patients developed a PE after discharge from the hospital, all within 30 days of undergoing gastric bypass surgery. The average BMI of 61 kg/m
However, superobese males—those with a BMI of 50 or more—and those with an anastomotic leak had the greatest incidence of PE (4% in each group).
Most of the 11 patients presented with multiple risk factors for PE, Dr. Abou-Nukta said. “Sixty percent of patients who experienced this complication had three or more risk factors.” Risk factors include male gender, a BMI over 50, venous stasis disease, truncal obesity, sleep apnea, and immobility.
Patients are considered at high risk preoperatively if they have sepsis or two or more of these risk factors, Dr. Abou-Nukta said.
“For these patients, we extend the chemical prophylaxis to several weeks after discharge. Very high risk patients also get an [inferior vena cava] filter,” he added.