From the annual meeting of the Society for Clinical Vascular Surgery.
Physicians often use medicines “off label,” and surgeons often move beyond the approved indications of surgical devices to use them in new ways. Sometimes this works out well, and sometimes not.
An example: Good outcomes from thoracic endovascular aortic aneurysm repair (TEVAR) since approval of the first thoracic stent-graft for aneurysm disease in 2005 have inspired surgeons to apply TEVAR to non-aneurysm pathologies. As they have done so, the number of treatment-related complications have increased, said Dr. Peter H. Lin of Baylor College of Medicine, Houston.
Dr. Lin and his team analyzed 7 years of data from his institution to identify factors that increased the risk for failed TEVARs, comparing 284 successful TEVARs with 19 failed procedures that necessitated explantation of the device.
They found that when surgeons didn’t follow the “Instructions for Use” of the stent-grafts produced by the manufacturer or the Food and Drug Administration, things were more likely to go wrong. The odds of a TEVAR failure increased five-fold after implantation of the device in a way that didn’t follow the Instructions for Use (predominantly by implanting a device that was undersized for a particular patient.) The risk of TEVAR failure increased eight-fold in patients treated for acute aortic dissection, and increased 12-fold in patients with connective tissue disorder. Neither of those subgroups of patients are included in the Instructions for Use, Dr. Lin said.
In patients with both aortic dissection and a connective tissue disorder, the TEVAR lasted only 2 weeks on average before the stent-graft had to be removed. Patients with those two conditions should no longer be considered for TEVAR, he said.
“Failure” had life-threatening consequences. Four years after the original surgery, only 36% of patients with failed TEVARs were alive, compared with 86% of those with successful TEVARs.
Medical and surgical progress requires that physicians think outside the box and explore new ways to use the drugs and tools at their disposal while searching for new treatments. But it’s equally important to let patients know the potential risks when a physician isn’t following instructions, and to do follow-up studies like Dr. Lin’s so that we get a clearer picture of what those risks might be.