Endovascular Coiling of Ruptured Very Small Dissecting Fusiform Aneurysm of Posterior Inferior Cerebellar Artery with Parent Artery Preservation by Microcatheter Auto-Assistance

The Safety and Efficacy of Endovascular Treatment for Very Small Ruptured Anterior Communicating Artery Aneurysms: A Large Single-Center Experience With 81 Consecutive Cases

OBJECTIVE

This study aimed to investigate the safety and efficacy of endovascular embolization for very small ruptured anterior communicating artery (AcomA) aneurysms.

METHODS

From August 2015 to June 2020, 81 patients with very small (≤3 mm) ruptured AcomA aneurysms treated endovascularly were enrolled in this study. Clinical and radiographic data were analyzed retrospectively, including the aneurysm occlusion rate, complications, and clinical outcome.

RESULTS

Among 81 patients, simple coiling embolization was performed in 52 cases and stent-assisted embolization in 29 cases. Immediate angiography demonstrated complete occlusion in 59 (72.8%) aneurysms, residual neck in 20 (24.7%) aneurysms, and residual lumen in 2 (2.5%). Procedure-related complications rate was 2.5% (2 of 81), all of which were transient thromboembolic events. Angiographic follow-up outcomes of 60 patients (mean: 6.8 ± 3.2 months) revealed complete occlusion in 91.7% (55 of 60), with recurrence in 1 patient. The mean clinical follow-up time was 22.6 ± 11.4 months and good prognosis rates (6-month modified Rankin Scale score: 0-2) reached 90.2% (73 of 81). The differences in aneurysm occlusion and procedure-related complications between the simple coiling group and the stent-assisted coiling group were not statistically significant.

CONCLUSIONS

Coiling with or without stent-assisted technique for the treatment of very small ruptured AcomA aneurysms was safe and effective.

Surgical Management and Outcomes of Aneurysms of Posterior Inferior Cerebellar Artery: Location-Based Approaches with Review of Literature

Background  Posterior inferior cerebellar artery (PICA) is a tortuous, variable, and uncommon site for aneurysms. Surgical management of PICA aneurysms involves careful selection of approach based on the location of the aneurysm and meticulous dissection of the neurovascular structures and perforators.

Materials and Methods  We did a retrospective review of all the PICA aneurysms operated at our institute in the past 10 years along with the site, presentation, and approach used for the same. Preoperative World Federation of Neurosurgical Society scores and follow-up modified Rankin scores (mRS) were also evaluated. During the same period, data for intervention cases of PICA aneurysm were also collected with follow-ups for a comparative analysis.

Results  A total of 20 patients with 21 PICA aneurysms were reviewed. All the reviewed cases presented with subarachnoid hemorrhage, and the most common location was the lateral medullary segment and vertebral artery (VA)–PICA junction. Midline approaches were used for distal PICA cases, with far-lateral approach reserved for anterior medullary/VA–PICA junction. No lower cranial nerve palsies were recorded at follow-up. Four cases needed cerebrospinal fluid diversion and two developed cerebellar infarcts. All cases were mRS 0 to 2 at follow-up.

Conclusion  Our series compares well with some of the larger surgical series of PICA aneurysms. This may be due to early referral patterns and early surgery (<24 hours) policy at our institution. Anatomical knowledge of PICA anatomy and sound perioperative management are keys to good outcomes in these cases.

Clinical Importance of the Posterior Inferior Cerebellar Artery: A Review of the Literature

The posterior inferior cerebellar artery (PICA), with its unique anatomical complexity, is of great clinical importance and involved in many diseases including aneurysm, ischemic stroke, neurovascular compression syndrome (NVCS), arteriovenous malformation (AVM), and brain tumor. However, a comprehensive systematic review of the importance of the PICA is currently lacking. In this study, we perform a literature review of PICA by searching all the associated papers in the PUBMED database hoping to provide a better understanding of the artery. The PICA has tortuous and variable course and territory, divided into 5 segments. Various aneurysms involving PICA were not uncommon, of which the treatment is challenging. The PICA infarct typically manifests lateral medullary syndrome (LMS) and is more likely to cause mass effects. The PICA frequently compresses the medulla and the cranial nerves resulting in various neurovascular compression syndromes (NVCS). Arteriovenous malformation (AVM) fed by PICA are associated with aneurysm and dissection which have high risk of rupture and worse outcome. PICA injured by head trauma can cause fatal SAH. VA terminating in PICA probably cause Bow hunter's syndrome (BHS). The PICA supplies many brain tumors and can be used in intracerebellar chemotherapy. The PICA can be exposed and injured during surgeries especially in telovelar approach, and it also plays an important role in bypass surgeries, hinting the surgical importance of PICA. In conclusion, PICA is very important in clinical practice.

Vertebral artery and posterior inferior cerebellar artery aneurysms: Results of microsurgical treatment of eighty patients

Background

The choice of surgical approaches and options for the microsurgical vertebral artery (VA) and posterior inferior cerebellar artery (PICA) aneurysms repair remains controversial.

Methods

A retrospective analysis of the clinical, surgical, and angiographic data of 80 patients with VA and PICA aneurysms treated from 2012 to 2018 was performed.

Results

The aneurysms were saccular in 50 cases (62.5%) and fusiform in 30 cases (37.5%). The median suboccipital craniotomy was the most common approach (73.8%). Retrosigmoid craniotomy was performed in 25% of patients. There were the following types of microsurgical operations: neck clipping (61.25%), clipping with the artery lumen formation (13.75%), trapping (10%), proximal clipping (5%), and deconstruction with anastomosis (10%). Fifty-seven (71.3%) patients were discharged without worsening of the clinical signs after surgery. The most common postoperative neurological disorder was palsy of IX and X cranial nerve revealed in 14 (17.5%) patients. No fatal outcomes or patients in vegetative state were identified. The complete occlusion of PICA and VA aneurysms according angiography was in 77 (96.3%) cases.

Conclusion

Microsurgical treatment is an effective method for VA and PICA aneurysms. The majority of VA and PICA aneurysms do not require complex basal approaches. A thorough preoperative planning, reconstructive clipping techniques, and anastomoses creation, as well as patient selection based on the established algorithms and consultations with endovascular surgeons, may reduce the number of complications and increase the rate of complete microsurgical occlusion in VA and PICA aneurysms.

[Microsurgical treatment of aneurysms of vertebral and posterior-lower cerebellar arteries: surgical approaches, exclusion options, treatment results]

Aneurysms of vertebral (VA) and posterior inferior cerebellar arteries (PICA) are relatively rare pathologies and account for 3.4% of the total number of intracranial aneurysms.

MATERIAL AND METHODS

The experience of microsurgical treatment of 67 patients with VA and PICA aneurysms in N.N. Burdenko National Medical Research Center for Neurosurgery of the RF Ministry of Health from 2012 to 2017 is presented.

RESULTS

Most patients underwent reconstructive microsurgical interventions: clipping of the aneurysm neck in 42 (62.7%) patients and complex clipping with the formation of arterial opening - in 10 (14.9%). Exclusion of the aneurysm together with the carrier artery (trapping, proximal clipping) was performed on 10 (14.9%) patients. In 5 (7.5%) patients, deconstruction of the carrier artery of the aneurysm was performed after creating local anastomoses. The radical exclusion of aneurysms in the studied group was 95.5%. Postoperative dysfunction of the caudal group of cranial nerves was detected in 11 (16.4%) patients. There were no lethal outcomes, or cases with vegetative status outcomes.

CONCLUSION

Microsurgical intervention is an effective way to treat VA and PICA aneurysms, subject to the principles of patient selection based on existing treatment algorithms as well as adherence to an interdisciplinary approach.