OBJECTIVE To date, treatment of complex unruptured
intracranial aneurysms (UIAs) remains challenging. Therefore, advanced techniques are required to achieve an optimal result in treating these patients safely. In this study, the safety and efficacy of rapid ventricular pacing (RVP) to facilitate microsurgical
clip reconstruction was investigated prospectively in a joined neurosurgery, anesthesiology, and cardiology study. METHODS Patients with complex UIAs were prospectively enrolled. Both the safety and efficacy of RVP were evaluated by recording cardiovascular events and outcomes of patients as well as the amount of
aneurysm occlusion after the
surgical clip reconstruction procedure. A questionnaire was used to evaluate
aneurysm preparation and
clip application under RVP. RESULTS Twenty patients (mean age 51.6 years, range 28-66 years) were included in this study.
Electrode positioning was easy in 19 (95%) of 20 patients, and removal of
electrodes was easily accomplished in all patients (100%). No complications associated with the placement of the pacing
electrodes occurred, such as cardiac perforation or
cardiac tamponade. RVP was applied in 16 patients. The mean
aneurysm size was 11.1 ± 5.5 mm (range 6-30 mm). RVP proved to be a very helpful tool in
aneurysm preparation and
clip application in 15 (94%) of 16 patients. RVP was used for a mean duration of 60 ± 25 seconds, a mean heart rate of 173 ± 23 bpm (range 150-210 bpm), and a reduction of mean arterial pressure to 35-55 mm Hg. RVP leads to softening of the
aneurysm sac facilitating its mobilization,
clip application, and closure of the
clip blades. In 2 patients,
cardiac events were documented that resolved without permanent sequelae in both. In every patient with successful RVP (n = 14) a total or near-total
aneurysm occlusion was documented. In the 1 patient in whom the second RVP failed due to pacemaker
electrode dislocation, additional temporary clipping was required to secure the
aneurysm, but was not as sufficient as RVP. This led to an incomplete clipping of the
aneurysm and finally a remnant on postoperative digital subtraction angiography. A pacemaker lead dislocation occurred in 3 (19%) of 16 patients, but intraoperative repositioning requires less than 20 seconds. Outcome was favorable in all patients according to the modified Rankin Scale. CONCLUSIONS To the best of the authors' knowledge this is the first prospective interdisciplinary study of RVP use in patients with UIAs. RVP is an elegant technique that facilitates
clip reconstruction in complex UIAs. The safety of the procedure is good. However, because this procedure requires extensive preoperative cardiological workup of the patient and an experienced neurosurgery and neuroanesthesiology team with much cerebrovascular expertise, actually it remains reserved for selected elective cases and highly specialized centers. Clinical trial registration no.: NCT02766972 (clinicaltrials.gov).