Causes of 30-day bariatric surgery mortality: with emphasis on bypass obstruction.

Background: This is a study of the causes of 30-day postoperative death following surgical treatment for obesity and a search for ways to decrease an already low mortality rate.

Methods: Data were contributed from 1986-2004 to the International Bariatric Surgery Registry by 85 sites, representing 137 surgeons. A spread-sheet was prepared with rows for causes and columns for patients. The 251 causes contributing to 93 deaths were then marked in cells wherever a patient was noted to have one of the causes. Rows and columns were then moved into positions that provided patterns of best fit.

Results: 11 patterns were found. 10 had well known initiating causes of death. Overall operative 30-day mortality was 0.24% (93 / 38,501). The most common cause of death was pulmonary embolism (32%, 30/93). 14 deaths were caused by leaks (15%, 14/93), and were equally prevalent after simple (15%, 2/14) or complex (15%, 12/79) operations. Small bowel obstruction caused 8 deaths, exclusively after complex operations. 5 of these involved the bypassed biliopancreatic limb and were defined as "bypass obstruction".

Conclusions: A spread-sheet study of cause of 30-day postoperative death revealed a rapidly lethal initiating complication of Roux-en-Y gastric bypass obstruction that requires the earliest possible recognition and treatment. Bypass obstruction needs a name and code to facilitate recognition, study, prevention and early treatment. Spread-sheet pattern analysis of all available data helped identify the initiating cause of death for individual patients when multiple data elements were present.