Predictors of patency of excimer laser–assisted nonocclusive extracranial-to-intracranial bypasses

Abstract

Object Excimer laser–assisted nonocclusive anastomosis (ELANA) is a technique that can be used for extracranial-to-intracranial (EC-IC) bypasses, without the necessity of temporary occlusion of the donor or recipient artery. Information on predictors of patency of EC-IC bypasses in general and the ELANA bypass in particular is sparse. The authors studied 159 ELANA EC-IC bypasses to find predictors of patency. Methods From a prospective database of patients who underwent EC-IC bypass surgery, 143 consecutive patients who underwent a total of 159 ELANA bypasses were studied. The associations of patient characteristics, surgical aspects, and technical aspects specific to the ELANA technique with intraoperative and postoperative bypass patency were studied using logistic regression analysis. Results At the end of the operation, 146 (92%) of the 159 bypasses were patent. A first attempt to create a bypass was almost 8 times more likely (OR 7.6, 95% CI 2.1–27.5; p = 0.02) to result in a patent bypass than a second attempt. Administration of a small amount of heparin during the operation was also associated with bypass patency (OR 5.2, 95% CI 1.1–24.9; p = 0.04). One hundred twenty-three (77%) of the 159 bypasses were functional at patency assessments during the 1st month after the operation. Older age (OR 1.043 for every year of increase in age, 95% CI 1.010–1.076; p = 0.01), male sex (OR 2.9, 95% CI 1.3–6.5; p = 0.01), and high intraoperative bypass flow (OR 1.017 for every milliliter per minute increase in flow, 95% CI 1.004–1.030; p = 0.01) were associated with postoperative bypass patency. Conclusions Attempts to create a second EC-IC ELANA bypass after the first one are more likely to fail, whereas administration of heparin to the patient during the procedure increases the intraoperative bypass patency rate. Postoperative patency results are better in male and in older patients. Intraoperative bypass flow measurements are essential because high bypass flow is an important determinant of postoperative patency.