Development of anterior inferior cerebellar artery pseudoaneurysm after gamma knife surgery for vestibular schwannoma. A case report and review of the literature

Abstract

Gamma knife surgery (GKS) is a well-established modality for controlling the progression of vestibular schwannomas. Adverse effects of this treatment are extremely rare but include cyst formation and malignant transformation. We report a case of anterior inferior cerebellar artery (AICA) pseudoaneurysm development rupture presenting as a poor WFNS grade subarachnoid haemorrhage. This is only the fourth case of aneurysm development (AICA aneurysm) following GKS reported but due to its serious nature we believe this potential complication warrants awareness in those offering this treatment.

Ruptured de novo Aneurysm following Gamma Knife Surgery for Arteriovenous Malformation: Case Report

“…The aneurysm wall showed disruption of the elastic lamina. The location and features of the aneurysm were consistent with the characteristics of a GKS-induced aneurysm [21,22,23,24,25,27]. As far as we know, this is the 3rd case of aneurysm formation and the 1st case of ruptured de novo aneurysm formation presenting with subarachnoid hemorrhage after GKS for AVM.…”

“…Seven cases of aneurysm formation after GKS have been documented in the literature [21,22,23,24,25,26,27]. Two of these cases involved using GKS for AVM [21,26].…”

“…In previous literature reports, among 7 patients who had de novo aneurysm formation after GKS, 2 patients underwent surgery, 4 patients received endovascular treatment, and another patient received conservative management to treat a thrombosis that occurred during endovascular treatment [21,22,23,24,25,26,27]. Our patient underwent endovascular treatment, which can be applied in cases of inaccessible aneurysm area and aneurysm with severe brain edema.…”

“…The demanding latency period from surgery to complete obliteration and radiation-induced changes are major disadvantages of the use of GKS for AVM [15,18,19,20,21,22,23,24,25,26,27]. Vasculopathy-related lesions, such as cysts, vessel occlusions, and aneurysms, are relatively late-onset problems of using GKS for AVM.…”

Incidentally Discovered Unruptured AICA Aneurysm After Radiosurgery for Vestibular Schwannoma

“…Of these, seven aneurysms were associated with SRS and four were in patients treated for VS (4,5,7,8). Since then, there have been two other cases (6,9), bringing the total to at least six reports of aneurysms discovered after SRS for posterior fossa tumors: five for VS (4Y8) and one for a cerebellopontine angle meningioma (9) ( Table 1). In the cases of patients with VS, all aneurysms were discovered after subarachnoid hemorrhage.…”