gms | German Medical Science

Objective: The morphology of cerebral aneurysms is highly variable. Complex aneurysms may result in difficult surgical exposure for clip ligation. Secure clip application is often not feasible without temporary intraaneurysmal pressure reduction. Softening of aneurysms can be accomplished with various techniques, and transient rapid ventricular pacing (RVP) has been shown to have several advantages. We describe here our experience with this technique in a series of 18 patients.

Methods: We analyzed demographic data, aneurysm characteristics, application characteristics, radiological and clinical outcome, and procedure specific complications.

Results: Eighteen patients (11 women, 7 men; mean age 54 years) underwent microsurgical clipping of intracranial aneurysms: anterior communicating artery (7 patients), paraclinoid internal carotid artery (4 patients), middle cerebral artery (2 patients), posterior communicating artery (2 patients), internal carotid artery bifurcation (2 patients) and anterior choroideal artery (1 patient). Eight patients (44%) had suffered subarachnoid hemorrhage from aneurysm rupture, 10 patients (56%) had carried incidental aneurysms. Mean aneurysm size was 12 mm (range 3-64). Reasons for transient RVP were impracticality of temporary proximal vessel clipping in paraclinoid internal carotid artery aneurysms (4 patients) and better visualization with softening of aneurysms (14 patients). Mean transient RVP lasted 110 sec (range 19-345) with modulating heart rate to 150-200 beats per minute. In 5 patients a single maneuver of RVP was carried out, in 7 patients a second, in 2 patients a third, in 2 patients a fourth and in 1 patient a fifth. In 16 patients (89%) transient RVP facilitated clip application, while in 2 patients aneurysm clipping still could not be achieved with RVP (1 patient with a subtotally calcified, partially thrombosed giant aneurysm and in 1 patient pace maker probe could not placed correctly). After RVP cessation all patients showed sinus rhythm without transient atrial fibrilliation. In 17 patients (94%) complete aneurysm occlusion was reached. In 2 patients postoperative cranial computed tomography revealed territorial cerebral infarction (Heubner and lentico-striate territory) with hemiparesis in one patient.

Conclusion: In selected patients RVP is a useful technique to facilitate clip ligation of complex aneurysms. The use of RVP is limited in patients with calcified and partially thrombosed aneurysms.