Smoking May Increase Brain Aneurysm Recurrence

By Crystal Phend
PHILADELPHIA, March 20 -- Cerebral aneurysms recurred 4.53 times more often among smokers than nonsmokers despite successful endovascular coil embolization, researchers found. Smokers also comprised the majority of patients who required retreatment, Erol Veznedaroglu, M.D., of Thomas Jefferson University and Jefferson Hospital for Neuroscience here, and colleagues reported in the April issue of the Journal of Neurosurgery. These findings from the retrospective study suggest that surgery to clip off the aneurysm may be a better option than coiling for patients who smoke, Dr. Veznedaroglu said. "If the patient is a heavy smoker and has been a heavy smoker for many years," he said, "that really may make you lean toward doing a craniotomy for clip ligation, which is a more durable procedure."
Treatment with endovascular coil embolization rather than traditional surgical clipping improves survival without disability, but one disadvantage has been the higher risk of recurrence when the coils become compacted, the researchers said.
Smoking presents a greater risk for growth and rupture of known aneurysms than hypertension, family history, or any other factor, Dr. Veznedaroglu said. It is also the only environmental factor consistently linked to risk of developing brain aneurysm.
Although carbon monoxide in cigarette smoke likely is the likely culprit, damaging already weakened arterial wall lining in aneurysm patients, it was unknown whether it was a factor in aneurysm recurrence as well, Dr. Veznedaroglu said.
So his group retrospectively reviewed charts of all 23 men and 87 women with cerebral aneurysm who were admitted for coil embolization treatment at a single center over a one-year period.
During the average 30 months of follow-up, 60.9% of men and 36.8% of women had evidence of a change in shape of the coil mass and increased inflow to the aneurysm.
Overall, 69.6% of men and 51.7% of women had a history of smoking.
Among those with evidence of coil compaction, 12 of the 14 men and 23 of the 32 women had a history of smoking.
Smokers were 4.53 times more likely to have aneurysm recanalization after successful initial embolization overall (95% CI 1.95 to 10.52).
The risk for smokers was significantly elevated among women (OR 3.72, 95% CI 1.45 to 9.54) but not for men, likely because of the smaller sample size (OR 7.50, 95% CI 1.02 to 55.00), the researchers said.
Only 13% to 14% of patients required retreatment because regrowth was small (less than 10%). One man and two women underwent craniotomy with clip ligation and two men and 10 women underwent retreatment with detachable coils.
Two-thirds of the men and 58% of the women who needed retreatment were smokers.
Patients who quit smoking after aneurysm treatment did not appear to be at lower risk of recurrence, but the sample size was too small to have detected a difference, the researchers said.
Nevertheless, until prospective data is available, "patients should be counseled about smoking cessation by primary care physicians, neurosurgeons, neurologists, endovascular surgeons, and anyone involved in their care," the researchers concluded.
They noted that the study included only a fraction of patients who were treated at their institution for brain aneurysm because of missing follow-up or smoking status data or because their aneurysm was fusiform or treated with balloon occlusion.
Dr. Veznedaroglu reported no conflicts of interest.
Primary source: Journal of NeurosurgerySource reference:Ortiz R, et al "Cigarette smoking as a risk factor for recurrence of aneurysms treated by endosaccular occlusion" J Neurosurg 2008; 108: 672-675.