Increase in diameters of vasospastic intracranial arteries by intraarterial papaverine administration

Object. This study was conducted to determine if there is a change in intracranial arterial diameters after papaverine infusion for vasospasm and to determine whether the change occurs in proximal, intermediate, and distal arteries. Methods. The authors measured arterial diameters retrospectively in all patients who received intraarterial papaverine for treatment of vasospasm between November 1992 and August 1995. Patients who received papaverine in the same session with or following angioplasty were excluded. Measurements were made in a blinded manner with the aid of a magnification loupe at 12 predetermined sites on each angiogram before and after papaverine infusion. Eighty-one treatments in 34 patients were included. Angiograms obtained at the time of presentation with subarachnoid hemorrhage (SAH) were examined in 26 of the 34 patients. Nine carotid territories visualized by repeated angiography on the day after infusion were examined to determine the duration of the papaverine effect. Conclusions. In all treatment groups an increase was found in the average arterial diameters ranging from 2.8 to 73.9%, with a mean increase of 26.5%. Increases in diameter were observed in proximal, intermediate, and distal arteries. The timing of treatments ranged from Day 3 to Day 19 post-SAH, and there was no relationship between timing and arterial responsiveness (r = -0.06). There was a moderately good correlation between the degree of vasospasm in an artery and its responsiveness to papaverine (r = -0.54, -0.66, and -0.66, for proximal, intermediate, and distal arteries, respectively). The effect of papaverine did not persist until the following day in patients in whom repeated angiography was performed.