(Reuters Health) - - If you live in England and the largest blood vessel in your body is beginning to blow up like a balloon, you are more likely to receive surgery later, when the blood vessel is closer to bursting, and 3.6 times more likely to die because the problem wasn't corrected in time than if you were in the U.S., according to a new study.
In addition, the odds of being hospitalized in England because that blood vessel has ruptured are more than double those in the U.S., researchers found.
The observational study raises questions of whether treatment for the condition, known as an abdominal aortic aneurysm, is optimal, said chief author Dr. Alan Karthikesalingam, a clinical lecturer in vascular surgery at St. George’s University of London. But to suggest that the care is inadequate "is probably a bit strong. It would be stretching it to say that," he said.
Deciding when to do surgery can be tricky because some aneurysms are too small or too slow-growing to cause a problem, and the surgery to correct them can be risky. Thus, if the ballooning is small, doctors often just keep an eye on it.
International guidelines say that surgery, either with a traditional operation or through the blood vessel itself, should be considered when the diameter of the aneurysm has reached 55 millimeters (2.2 inches) in men or 50 mm (2 inches) in women. However, the practice varies by country.
"We know that the percentage of patients who undergo repair just above or underneath the guidelines varies quite a lot," Karthikesalingam said. "The impetus for this work was to establish whether the variation would have an impact at a population level in terms of mortality attributable to that disease process."
It appears that it does.
Using eight databases that tracked aneurysm-related deaths from 2005 through 2012, Karthikesalingam and his colleagues found that the rate of aneurysm repair was twice as high in the United States at 64.17 per 100,000 people versus 31.85 per 100,000 in England.
The rate of aneurysm rupture was 2.23 times higher in England than in the U.S., and the odds of dying from an aneurysm were 3.45 times higher in England than in the U.S.
The operation itself didn't seem to be the problem. The in-hospital and three-year survival rates among those who underwent a repair were comparable for patients in England and the U.S.
Although the guidelines recommend repair at 55 mm for men, the average aneurysm diameter at the time of repair was 64 mm in England versus 59 mm in the U.S. For women, where the recommendation is 50 mm, the average was 62 mm in England and 56 mm in the U.S.
"We're talking a difference of 5 mm on average in both countries. That difference is extremely subtle but it does seem to be associated with a very big difference in aneurysm-related death," Karthikesalingam told Reuters Health by phone.
"I think these findings provide support for my practice to recommend earlier aortic aneurysm repair at smaller aneurysm diameters," Dr. Pegge Halandras, an associate professor in the division of vascular surgery and endovascular therapy at Loyola University Chicago Stritch School of Medicine said by email.
"In the current endovascular era, this study will likely reinforce national trends for elective repair of smaller aortic aneurysms," said Halandras, who was not involved in the study. "I think it is important for consumers to know about these study results so that the risks and benefits of observation versus aortic aneurysm repair can be discussed with their physicians."
"It reinforces that the individual threshold should be discussed closely between the surgeon and the patient," Karthikesalingam said. "Ultimately it comes down to a balance of risk."
In 2012, the last year of data examined by the investigators, 67 percent of the repairs in England were done through the blood vessels. The rate in the United States was 75 percent.
SOURCE: bit.ly/2g3yBtx New England Journal of Medicine, online November 23, 2016.