Treatment of the Posterior Circulation Aneurysms / 대한뇌혈관외과학회지

OBJECTIVE: Endovascular treatment is now accepted as an initial treatment modality, especially in cases of posterior circulation aneurysms. The purpose of this study was to review the treatment outcomes and to emphasize the necessity of maintaining the surgical ability for posterior circulation aneurysms. METHODS: During the past 10 years, 570 patients have been treated for cerebral aneurysms at our institute. Among these patients, 34 harbored posterior circulation aneurysms. From January 2004 to June 2008, 13 of the 34 patients were treated by endovascular coiling. We retrospectively reviewed the clinical outcome, cerebral angiograms, and other radiological imagings through a comparative study of the pre- and post-endovascular treatment periods. RESULTS: Overall, 9 (69.2%) of the pre-endovascular treatment period group and 20 (95.2%) of the endovascular treatment period group had good outcomes. The mean post-operative hospital days for these groups were 38.6 and 21.1, respectively. Patients in the endovascular treatment period group had shorter post-operative hospital periods and better outcomes than those in the pre-endovascular treatment period group. CONCLUSION: It is recommended that multimodality treatment involving microsurgical clipping and endovascular coiling is used to obtain better results in the treatment of posterior circulation aneurysms. These results suggest that although the trend toward endovascular treatment as the initial aneurysm therapy for posterior circulation aneurysms is also enhancing, it might be necessary to maintain the surgical ability for posterior circulation aneurysm.

A comparative analysis of the outcome of surgical clipping and endovascular treatment in the ruptured posterior circulation aneurysms / 대한뇌혈관외과학회지

OBJECTIVE: Posterior circulation aneurysms are difficult lesions to treat surgically because they have a potential for high morbidity and mortality. We have used both surgical clipping and endovascular coiling techniques to treat posterior circulation aneurysms and report the comparative results of these two treatment modalities. METHOD: Of 999 patients with intracranial aneurysms admitted between January 1996 and May 2005, 77 (7.7%) had aneurysms of the posterior circulation. Forty-three cases of posterior circulation aneurysms (43/77 [55.8%]) who were treated with clipping or coiling were included in this study. These aneurysms were located in the following sites: 20 cases (46.5%) in the basilar bifurcation artery (BBA), 9 cases (20.9%) in the superior cerebellar artery (SCA), 7 cases (16.7%) in the vertebral artery (VA), 4 cases (9.5%) in the distal posterior inferior cerebellar artery (PICA), and 4 cases (9.5%) in the posterior cerebral artery (PCA). Fourteen (31%) aneurysms were treated with surgical clipping and 29 (69%) aneurysms were treated with endovascular coiling. The treatment outcomes from outpatient follow-up 12 months after treatment were analyzed according to Glasgow outcome scale (GOS). RESULT: Overall, 10 patients who were treated with surgical clipping and 22 (74.4%) patients who were treated with endovascular therapy had good outcomes (GOS, 4~5). The mortality of surgical treatment and endovascular coiling was approximately 7.1% (1/14) and 6.9% (2/29), respectively. The postoperative complications included two transient cranial nerve deficits in the patients who underwent surgical treatment, whereas the patients who underwent endovascular treatment had more serious complications (two intra-operative aneurysm ruptures and three embolic infarctions). CONCLUSION: Patients treated with endovascular coiling had more severe intra-procedure rebleeding than patients treated with surgical clipping; however, there was no statistical significant difference in overall outcome between the two treatment groups. Both surgical and endovascular approaches to posterior circulation aneurysms can achieve good outcomes, and appropriate choice depends on the judgment of the surgeon and neurointerventionist based on angiographic findings. More cautious judgment according to patient factors and angiographic findings can improve the final results.

Frequency of Aneurysmal Subarachnoid Hemorrhage in Perimesencephalic Subarachnoid Hemorrhage and Need of 4-vessel Angiography

OBJECTIVE: In this study, each of the frequency of nonaneurysmal perimesencephalic subarachnoid hemorrhage(N-PMSH), and the clinical and radiologic features, incidence and location of aneurysmal perimesencephalic subarachnoid hemorrhage(A-PMSH), based on aneurysmal rupture and nonaneurysmal subarachnoid hemorrhage in patients with spontaneous subarachnoid hemorrhage, are investigated for clinical application. METHODS: Patients who showed perimesencephalic subarachnoid hemorrhage, among the 388 patients with subarachnoid hemorrhage admitted into the our hospital from March 1994 to November 2002, were extracted ; and their charts and angiographies were examined retrospectively. They were divided into two groups - aneurysmal perimesencephalic subarachnoid hemorrhage group and nonaneurysmal perimesencephalic subarachnoid hemorrhage group - and comparative analysis was conducted on the clinical patterns and radiologic characteristics of each group. RESULTS: There were 22 patients(5.68%) with perimesencephalic subarachnoid hemorrhage(PMSH) among 388 patients with spontaneous subarachnoid hemorrhage. Of the 22 PMSH, 8 patients(36%) were aneurysmal PMSH(A-PMSH), 14 patients(64%) were nonaneurysmal PMSH(N-PMSH). N-PMSH occurred not only in the posterior circulation(5 cases), but also in the anterior circulation(3 cases). There was no difference in the CT features of PMSH between aneurysmal and nonaneurysmal cause. CONCLUSION: According to the above results, 4-vessel angiography is essential for patients with perimesencephalic subarachnoid hemorrhage, and CTA and MRA can be used as assisting diagnosis methods.

Posterior Circulation Aneurysm Surgery / 대한뇌혈관외과학회지

Surgical treatment of posterior circulation aneurysms are still challenging to the neurosurgeons, requiring highly skilled hands. Patients with intracranial aneurysms operated on from January 1984 to January 2003 have been reviewed retrospectively. During that period 104 patients with 110 posterior circulation aneurysms underwent operation in our institute. Among them 47 patients had 49 aneurysms at the basilar bifurcation. The posterior cerebral artery aneurysms (PCEAA) 11, the superior cerebellar artery aneurysms (SCAA) 18, the anterior inferior cerebellar aneurysms (AICAA) 6, the vertebral artery aneurysms (VAA) 8 and the posterior inferior cerebellar artery aneurysms (PICAA) 18. The surgical approaches for BBAA, SCAA and PCEAA (proximal to P4) were pterional route in 70 aneurysms and subtemporal in 4. Modified pterional approach was suitable for most of such aneurysms. For lower basilar trunk aneurysms (AICAA and VBJA), both far lateral suboccipital craniectomy and petrosal presigmoid approach had been tried and the presigmoid one seemed to be the choice of approach. The author achieved aneurysmal neck clipping in the 82 (73%) aneurysms, wrapping in other 15 and proximal clipping in the other 13. The operative mortality and morbidity were 6% and 17% each, which were comparable to the other series. Concerning surgical complications, transient oculomotor palsies were most frequent (38%), followed by transient hemiparesis, thalamic infarction, status epilepticus and peripheral infarction of the parent-arterial territory.

Management Outcome and Clinical Manifestation of Posterior Circulation Aneurysms VS. Anterior Circulation Aneurysm

OBJECT: With the recent variable treatment modalities and the development of microsurgical techniques, outcomes of surgical and medical management of aneurysm have shown much progress in the last 10 years. However, the management of posterior circulation aneurysm is still a debatable due to its difficulty in limited surgical approach, complicated anatomical structure and many small perforators to vital structure. The purpose of this study is to compare the results of clinical manifestation and outcome of surgery with respect to anterior and posterior circulation aneurysms. MATERIAL AND METHODS: We evaluated the 33 patients with PCAs(posterior circulation aneurysm) and 359 patients with ACAs(anterior circulation aneurysm) treated between 1994 and 1999, retrospectively. RESULTS: Posterior circulation aneurysms showed higher tendency(5 cases, 14.7%) to have unusual shapes, such as dissecting or fusiform compared with anterior circulation aneurysm(15 cases, 4.2%). There were more multiple aneurysms in posterior circulation aneurysm(8 cases, 26.5%) than anterior circulation aneurysm(59 cases, 16.2%). The number of patients with Hunt-Hess grade III or IV on admission were 91(25.3%) in anterior circulation aneurysms, and 14(42.4%) in posterior circulation aneurysms. There were higher incidences of vasospasm and acute hydrocephalus in patients with posterior circulation aneurysm. In cases of anterior circulation aneurysm, neck clipping was possible in 97%. But, in posterior circulation aneurysm, neck clipping was possible only in 67.7% of each. Two hundred forty four cases(85.0%) of all anterior circulation aneurysms and 22 cases(78.6%) of all posterior circulation aneurysms showed good recovery(GR) or moderate disability(MD). The postoperative mortality rates of anterior and posterior circulation aneurysms were 4.9% and 10.7%, respectively. CONCLUSION: These results indicate that there exist substantial differences with respect to that there were few difference in the aspect of surgery and management outcome between posterior circulation aneurysms and anterior circulation aneurysms.

Management Outcome in Cerebral Aneurysms of Posterior Circulation

A series of 51 consecutive patients with 55 cerebral aneurysms of the vertebrobasilar system is presented. Thirty aneurysms had their origins at the basilar artery(BA) bifurcation, 7 at the origin of the superior cerebellar artery (SCA), 4 at the posterior cerebral artery(PCA), 4 at the BA trunk, 8 from the vertebral artery(VA) at the origin of the posterior inferior cerebellar artery(PICA), and two from the PICA. The patient population consisted of 31 women and 21 men, with a mean age of 50 years(range 30-70 years). The overall mortality and morbidity rates at 6 months were 17.6%(9/51) and 13.7%(7/51), respectively. The most common cause of death was rebleeding(55.6%, 5/9). Nineteen patients had underwent only conservative treatment due to aneurysms classified as inoperable(6 cases), fatal rebleeding(5 cases), refusal against surgery(5 cases), poor Hunt and Hess grade that did not improve(2 cases), and one aneurysm that spontaneously disappeared. Treatments consisted of neck clipping in 16 patients, wrapping in 6, and endovascular therapy in 10. All of these treatment modalities were carried out after 2 weeks from initial insult. Treatment outcome was evaluated with Glasgow Outcome Scale(GOS) at 6 months after initial insult. Patients with Hunt and Hess(H-H) Grades I and II at admission had good outcome in 70.6%, whereas only 60% of patients with H-H Grades III and IV showed good outcome. But there was no statistically significant difference. Five patients with aneurysms which were located proximally had better outcome than those with distal aneurysm(100% good outcome vs 66.7%). All of ten patients who were treated with endovascular therapy showed good outcome, whereas only 13 out of 22(59.1%) patients who underwent either clipping or wrapping showed good outcome. There was statistically significant difference(p<0.05). As for the comparison of outcome according to the size of aneurysm and age of patients, we found no statistically significant difference. These results indicated that the location of aneurysm was one of important prognostic factor in vertebrobasilar system. Endovascular treatment may be a promising treatment option and considering the very high mortality from rebleeding early management may contribute to reduce the mortality and morbidity in posterior circulation aneurysm.

Surgical Treatment of Posterior Circulation Aneurysms

Aneurysms arising from the posterior circulation are 5-19% of total intracranial aneurysms. Althought many neurosurgeons have challended with various innovations but the confinned surgical space, complicated anatomical structure and many small perforators to vital organ of brain were remained the barrier that we we have to overcome. From July 1987 to December 1994, we have been operated on 23 cases of posterior circuation aneurysms among 409 cases of surgically treated all intracranial aneurysms. The present 5.6% of all intracranial aneurysms, the average age of these patients was 49 years old. The ratio of male to female was 1 : 1.8. The number of basilar bifurcation artery aneurysms(BBAA) were 14(61%), the posterior cerebral artery(PCA) aneurysms 3(13%), the upper basilar trunk aneurysm 1, posterior inferior cerebellar artery(PICA) aneurysm 3(13%), anterior inferior cerebellar artery(AICA) aneurysm 1 and vertebral artery aneurysm 1. Five patients had accompanined with anterior circulation aneurysm and one patient had concomitant arteriovenous malformation. We have successfully clipped 12 cases and wrapped 2 cases of BBAA aneurysms through modified pterional approach and subtemporal approach according to the hight of basilar bifurcation and the other posterior circulation aneurysms are all clipped through most available approaches including lateral, far-lateral suboccipital and interhemispheric approach. Surgical outcome was good in 15 cases, fair in 4 cases, poor in 3 cases and one patient expired.

Symptomatic Hydrocephalus after Subarachnoid Hemorrhage

Hydrocephauls is one if the important complication of subarachnoid hemorrhage. The incidence of significant hydrocephalus secondart to spontaneous subrachnoid hemorrhage was 7.9%, We analyzed several factors possibly related to hydrocephalus following subrarachnoid hemorrhage in 439 patients between 1990 and 1992. The development of hydrocephalus after subarachnoid hermorrhage is multifactorial. We found the following factors were significantly related with the development of hydrocephalus after subarachnoid hemorrhage ; intraventricular hemorrhage, level of consciousness on admission, increasing age, hypertension history before subarachnoid hemorrhage, subarachnoid blood noted on CT scan, posterior circulation site of aneurysm.

Surgical Experience of Posterior Circulation Aneurysms: Clinical Analysis of 64 Cases

Surgical treatment of posterior circulation aneurysms are still challenging to the neurosurgeons, requiring highly skilled hands. During the past 10 years, the senior author(DH Han) operated upon 64 posterior circulation aneurysms. The number of the basilar bifurcation aneurysms(BBAA) were 31(48%), the posterior cerebral artery aneurysms(PCEAA) 7, the superior cerebellar artery aneurysms(SCAA) 10, the anterior inferior cerebellar aneurysms(AICAA) 3, the vertebro-basilar junction aneurysms(VBJA) 2, the vertebral artery aneurysms(VAA) 5 and the posterior inferior cerebellar artery aneurysms(PICAA) 6. The surgical approaches for BBAA, SCAA and PCEAA(proxinal to P4) were pterional route in 41 aneurysms and subtemporal in 4. Modified pterional approach was suitable for most of such aneurysms. For lower basilar trunk aneurysms(AICAA and VBJA), both far lateral suboccipital craniectomy and petrosal presigmoid approach had been tried and the presigmoid one seemed to be the choice of approach. The authors achieved aneurysmal neck clipping in the 48(75%) aneurysms, wrapping in other 8 and proximal clipping in the other 8. The operative mortality and morbidity were 6% and 17% each, which were comparable to the other series. Concerning surgical complications, transient oculomotor palsies were most frequent(38%), followed by transient hemiparesis, thalamic infarction, status epilepticus and peripheral infarction of the parent-arterial territory.

Microsurgical Experience of Posterior Circulation Aneurysms

Aneurysms arising from the posterior circulation are relatively uncommon and are regarded as the most difficult aneurysms for surgical management because of its confined surgical space and complicated blood vessels around brain stem. Twenty cases of posterior circulation aneurysm were operated between Jan. 1984 and July, 1987. At the same period total surgically treated aneurysms were 181 cases. Among 20 cases, aneurysms at the basilar artery bifurcation were 12 cases, 4 cases at the SCA-basilar artery, 3 cases at the distal PICA and one case was at the PCA(P2-P3). Five patients had multiple aneurysms and one patient had concomitant arteriovenous malformation. For the operative management of these 20 cases, direct neck clipping was done in 16 cases and wrapping was done in 4 cases. Surgical outcome was evaluated: "good" in 10 cases, "fair" in 3 cases, "poor" in 6 cases and one patient expired. Surgical consideration of posterior circulation aneurysms was also disussed on the basis of personal experience.