SAN FRANCISCO — The number of hospitals at which external carotid to internal carotid bypass procedures are performed is increasing, but so is associated mortality, Sepideh Amin-Hanjani, M.D., said at the annual meeting of the Congress of Neurological Surgeons.
Growth of external carotid to internal carotid (EC-IC) bypass procedures is greatest at low-volume centers and among inexperienced surgeons, said Dr. Amin-Hanjani, of Harvard Medical School, Boston.
In an analysis of 558 operations performed at 158 American hospitals by 145 surgeons between 1992 and 2001, the annual number of admissions for EC-IC bypass almost doubled from 190 per year from 1992 to 1996, to 360 per year from 1997 to 2001. Mortality more than doubled, from 2.5% to 5.9%, Dr. Amin-Hanjani said.
The median numbers of procedures per hospital and per surgeon were 3 and 2, respectively, over the decade. For 29% of patients, their EC-IC bypass was the only one recorded at the hospital for the year, and for 42% of patients, their surgeon performed no other EC-IC bypass.
Cerebral ischemia was the indication in 74% of procedures, followed by unruptured aneurysms (19%), and ruptured aneurysms (7%). Mortality was highest (21%) in patients with ruptured aneurysms, followed by those with unruptured aneurysms (7.7%), and cerebral ischemia (2.4%).
These findings were based on data from the Healthcare Cost and Utilization Project's third Nationwide Inpatient Sample.
“This technically demanding procedure has become a very low-volume operation at nearly all U.S. centers,” Dr. Amin-Hanjani said. Surgeons need experience with at least 20-30 cases to achieve patency rates of 90%-100%.