Men also spend more time in the hospital after the operation, according to the new study by researchers at the University of Michigan Medical School. They believe that sex should be taken into account, along with other factors, to provide the best possible estimates of risk for patients undergoing neurosurgery.
The researchers analyzed data on 918 patients undergoing neurosurgery between 2006 and 2009. About 64 percent underwent brain surgery while 36 percent underwent spinal surgery.
Overall, 20.3 percent of men had complications within 30 days after surgery, compared to 11.3 percent of women.
The complication rate remained twice as high in men after adjustment for other factors — including age, tobacco and alcohol use, and health problems like high blood pressure, coronary artery disease, and diabetes.
Complications were also more common in older patients and in patients with coronary artery disease, says the journasl.
Men spent more time in the hospital than women: average 7.5 versus 5.7 days. Sex did not affect the average length of stay in the intensive care unit after surgery.
There are important differences in health between men and women, with men having higher rates of chronic diseases and earlier death. However, little is known about how sex might affect the risk of complications after surgery.
It's especially important to understand the factors affecting the risk of complications after neurosurgical procedures, which are increasing in scale and scope.
Neurosurgery carries relatively high complication rates — in the new study, overall rates were 18.6 percent after brain surgery and 10.8 percent after spinal surgery.
While acknowledging some important study limitations, the authors write, they "think that our findings yield important insight with regard to the relationship between sex and postoperative outcomes" and that that multiple factors likely contribute to the sex difference in complication rates, including "psychosocial, hormonal, or underlying disease differences."
For example, the lower complication risk in women could reflect better social support, "neuroprotective" effects of estrogen, or lower rates of cardiovascular disease.
"Closer monitoring and more rapid response" for patients at highest risk may help health care providers to respond appropriately to developing complications, and "plausibly" to reduce the risk of postoperative complications and death, the researchers believe.