MICROSURGICAL CLIPPING OF GIANT SACCULAR MIDDLE CEREBRAL ARTERY ANEURYSM: A CASE REPORT

Giant saccular middle cerebral artery aneurysm is rare vascular lesion and few cases have been reported in the literature. Microsurgical clipping is applied to treat a giant middle cerebral artery aneurysm .A 26 year-male presented with complain severe headache, mulple episodes of voming and one episode of sudden loss conscious since few hours prior to admission at emergency department. Cerebral Angiography showed a giant saccular middle cerebral artery (MCA) aneurysm. A standard right pterional approach applied to expose MCA and microsurgical clipping was performed. No any serious neurological complicaon was noted aer surgery except right facial palsy. Paent was discharged at the 12th day of surgery. Endovascular therapy as well as STA-MCA bypass surgery plus clipping are usually applied to manage the giant MCA aneurysm. However, alone microsurgical clipping is also eﬀecve and has beer result.


INTRODUCTION
Giant saccular middle cerebral artery aneurysms are rare lesion. Giant intracranial aneurysms are surgically complex and challenging lesion, with maximum diameter of 25mm or 1 more and mortality more than 60% within 2 year. The most common loca on of giant aneurysms is in internal caro d artery (ICA) and middle cerebral artery (MCA) region (16%-2 32%). MCA region is one of the most common sites for 3 rupture of giant aneurysm. Both endovascular and surgical management of giant MCA aneurysms are technically challenging issue due to its crucial natural history, unique anatomic features. The poor outcome or death in 30% of the pa ents has reported in direct surgical treatment of giant 4 MCA aneurysm. We describe a pa ent who underwent direct surgical clipping without bypass for ruptured giant aneurysm arising from bifurca on of M1 segment of right MCA with maximum diameter 2.8cm.

CASE PRESENTATION
A 26-year old male presented with complain of severe headache, mul ple episodes of vomi ng and one episode of loss of conscious (LOC) few hours prior to admission in emergency department. He was alert and neck s ffness without any neurological deficit, had past history right ear infec on. Computer Tomography (CT) scan demonstrated a large high density mass with subarachnoid hemorrhage (SAH) in right Sylvian cistern ( Figure A). Cerebral angiography disclosed aneurysm arising from bifurca on of M1 segment of right MCA measuring 2.8 x 2.4 cm having narrow neck at the origin measuring 2mm ( Figure B). Surgery was performed on the third day of ictus. A er performing right pterional craniotomy and opening dura, right MCA segment was then dissected in the Sylvian fissure to expose aneurysm beyond the origin of the len culostriate arteries. The MCA was persuaded distally to expose frontal, parietal and temporal segments were iden fied. The dome of aneurysm was punctured by a 25 gauze needle and 15ml bleed was aspirated. The aneurysm completely collapsed. The neck of aneurysm was seen and two fenestrated and one simple straight clipping were used a er applica on of temporary clips over parent vessels. Temporary clip was removed. Indocyanine Green (ICG) was used to be sure occlusion of the blood flow to aneurysm dome or not. A er being confirmed the complete occlusion of aneurysm, dome of aneurysm was cut off and sent for histopathology test. Pa ent developed right facial palsy and le upper and lower limb weakness as compared to right side of the body. Noncontrast CT was done a er 48 hours of surgery and right basal ganglia infarc on was noted ( Figure C). Tab clopilet 75mg was started and improvement in power was no ced slowly. Histopathology test reported that ssue with dilated and congested thin walled blood vessels and small thrombus th forma on. Pa ent was discharged on the 12 day of surgery.

DISCUSSION
Most of giant aneurisms are saccular variety and cons tute 5 approximately 5% of all intracranial aneurysm. Giant MCA aneurysms have always remained the most difficult lesion among cerebrovascular diseases to treat. Digital subtrac on angiography s ll provides most pivotal informa on to select the best treatment op on for complex aneurysm regardless of emerging 3D reconstruc on techniques of CT 6 angiography, MR-base flow modeling. Surgical therapy has grown up well with improvement in instrumenta ons, refinement of skull base microsurgical techniques, and applica on of anesthe c techniques like hypothermic circulatory arrest. Few giant aneurysms come to surgical management due to improved radiological imaging and earlier diagnosis of large aneurysm. The combined surgical morbidity and mortality for giant intracranial aneurysms have remained in the 20% to 50% 2 range in the recent years despite theMCA aneurysms have been described suitable for surgery. It may be due to cruel pathological anatomy, like aberrant arterial branches, intraluminal thrombus, wide aneurysm neck, atherosclero c aneurysm neck, and adherent perfora ng arteries. The management for giant cerebral aneurysm including MCA aneurysm with direct surgical procedure requires 1) exposure of aneurysm, 2) trapping of the parent artery, 3) incision of the aneurismal dome and removal of the thrombus, 4) 4 clipping of the aneurismal neck,5) release of the trapping. Complex aneurysms of the MCA are special challenge, to treat by surgical clipping, due to mul ple perforators that lead to difficult accessibility in M1 and M2 branches. A study done by Hideki et al reported that one case of ischemia was noted following clipping among four saccular giant MCA 7 aneurysms. Ischemia is unavoidable complica on. Therefore, intensive protec ve therapy for the brain as well as pre and intra-opera ve studies need to done well to evaluate cerebral tolerance to probable ischemia. Since the establishment of Guglielmi detachable coils in 1990, endless morbidity with surgical treatment and con nuous advancement in endovascular therapy have 8 inspired pursue at coiling of giant aneurysm. The indica on for Open microsurgery has been changed due to endovascular op on. However endovascular coiling is non invasive technique, complica on has been reported of a 10.5% morbidity rate and an 8% mortality rate in the recent series of large and giant aneurysm treated with endovascular coiling and higher rate of recurrence (52%) and retreatment 9 (47%) for giant aneurysm. Only smaller series or case reports have been studied treatment of giant MCA aneurysm. Few researchers have reported large series of revasculariza on in pa ent with 10 giant MCA aneurysm. A study done by Shi ZS et al that described applica on of endovascular coiling with bypass surgery for treatment of giant MCA aneurysm and 11 preserva on of perforator branches. There was no study discussed about ischemia well. Development of emboli at the occlusion site and inadequate flow from bypass may 12 lead to ischemic events and rupture of aneurysm. A study done by Hashi K et al that described that the ischemic complica ons occurred in 12 of the 137 cases within 24hours, in 11cases within 24-48hours, in 6 cases later 48 hours and at unknown mes in 5 cases; a total of 25% 13 (34/137) of all cases. In our pa ent, direct surgical clipping was essen al for the giant MCA aneurysm, since it had ruptured and had a mass effect over middle cranial fossa. So temporary clipping of MCA was applied over parent vessels. The dome of aneurysm was punctured by 25 gauze needle and 15ml of blood aspira on was done. It collapsed and permanent clipping of the giant aneurysm was applied. The dome of aneurysm was excised to decrease mass effect and sent for histopathology report. Although perfect outcome achieved by direct surgical clipping without bypass for giant M1 segment of MCA aneurysm, ischemia is an undeniable complica on encountered in treatment of giant MCA 13,14 aneurysm similar to other studies. This challenging issue should be studied well and overcome with the applica on of pre and intra-opera ve monitoring system. Enough studies with large number of cases of giant MCA segment aneurysm need to be researched for evalua on of outcome and complica ons.

CONCLUSION
Endovascular therapy as well as STA-MCA bypass surgery plus clipping are usually performed to manage the giant MCA aneurysm. Ischemic event is inevitable problem encountered during giant MCA aneurysm treatment whatever the surgical procedures are applied. Alone direct surgical clipping with excision of aneurysm is safe and effec ve for management of giant M1 segment of MCA aneurysm.

CONFLICT OF INTERESTS
There is no conflict of interests