Treatment of aneurysms by excision or trapping with arterial reimplantation or interpositional grafting. Report of three cases

Sequential Extradural Release of the V3 Vertebral Artery to Facilitate Intradural V4 Vertebral Artery Reanastomosis: Feasibility of a Novel Revascularization Technique

BACKGROUND

Revascularization of the intradural vertebral artery (VA) usually involves V3-V4 bypass using an interposition graft. The interposition of a graft increases surgical time, adds risks, and requires 2 suture lines.

OBJECTIVE

To assess the feasibility of an excision-reanastomosis of V4 by sequentially releasing V3.

METHODS

Twenty specimens were prepared for surgical simulation of a far-lateral approach. The third and fourth segments of the VA were exposed through the far-lateral approach bilaterally. The V3 segment was divided into three subsegments: (1) V3 f : from entry to C1 transverse foramen to the point of exit from C1 transverse foramen; (2) V3 s : from V3 f to the distal point of V3 within the sulcus arteriosus; and (3) V3 d : from point V3 leaves the sulcus arteriosus to its dural entrance. After transecting the VA 2 mm proximal to the posterior inferior cerebellar artery origin, each subsegment was released sequentially. We measured the lengths obtained before and after releasing each segment by pulling the VA along its main axis to recreate a V3-V4 excision-reanastomosis.

RESULTS

The V3 could not be effectively mobilized without release. When totally released, an average length of 13.15 mm was available for completing V3-V4 reanastomosis.

CONCLUSION

Complete release of V3 from all its adhesions in its extracranial course can provide an average length of 13.15 mm for excision-reanastomosis. The present study shows the anatomic feasibility of the use of V3 segment in primary anastomosis after excision of a diseased segment of the intradural VA, laying the basis for future clinical application.

Variations of Occipital Artery-Posterior Inferior Cerebellar Artery Bypass: Anatomic Consideration

BACKGROUND

Advances in diagnosis of posterior inferior cerebellar artery (PICA) aneurysms have revealed the high frequency of distal and/or dissecting PICA aneurysms. Surgical treatment of such aneurysms often requires revascularization of the PICA including but not limited to its caudal loop.

OBJECTIVE

To examine the microsurgical anatomy involved in occipital artery (OA)-PICA anastomosis at various anatomic segments of the PICA.

METHODS

Twenty-eight PICAs in 15 cadaveric heads were examined with the operating microscope to take morphometric measurements and explore the specific anatomy of bypass procedures.

RESULTS

OA bypass to the p2, p3, p4, or p5 segment was feasible with a recipient vessel of sufficient diameter. The loop wandering near the jugular foramen in the p2 segment provided sufficient length without requiring cauterization of any perforating arteries to the brainstem. Wide dissection of the cerebellomedullary fissure provided sufficient exposure for the examination of some p3 segments and all p4 segments hidden by the tonsil. OA-p5 bypass was placed at the main trunk before the bifurcation in 5 hemispheres and at the larger hemispheric trunk in others.

CONCLUSION

Understanding the possible variations of OA-PICA bypass may enable revascularization of the appropriate portion of the PICA when the parent artery must be occluded. A detailed anatomic understanding of each segment clarifies important technical nuances for the bypass on each segment. Dissection of the cerebellomedullary fissure helps to achieve sufficient exposure for the bypass procedures on most of the segments.

Surgical Flow Alteration for the Treatment of Intracranial Aneurysms That Are Unclippable, Untrappable, and Uncoilable

OBJECTIVE

The treatment of complex intracranial aneurysms remains challenging. One approach is the application of surgical flow alteration to treat aneurysms that are neither clippable, trappable, or coilable. The efficacy and limitations of surgical flow alteration have not yet been established.

METHODS

Cases of complex aneurysms treated with surgical flow alteration (proximal occlusion with or without bypass, distal occlusion with or without bypass and bypass only) were included in this retrospective study.

RESULTS

Among a total of 16 cases, there were 7 giant aneurysms (≥25 mm diameter) and 9 large aneurysms (>10 mm diameter); 15 of 16 aneurysms were unruptured. There were 8 aneurysms located in the anterior circulation, while the other 8 were in the posterior circulation. Aneurysms were treated with proximal occlusion in 10 cases and distal occlusion in 5 cases; in 1 case, the aneurysm occluded spontaneously after bypass without parent artery occlusion. All but 2 cases underwent prior or concurrent bypass surgery. Complete obliteration of the aneurysm at the latest imaging follow-up was shown in 12 of 16 cases (75.0%). Bypass patency was confirmed in 13 of 15 cases (86.7%). Surgery-related morbidity developed in 3 cases (18.8%, Glasgow outcome scale of 4) and all were perforator infarctions. There were no mortalities.

CONCLUSION

Surgical flow alteration resulted in a high rate of aneurysmal obliteration with acceptable morbidity. Although several limitations remained, it could represent an alternative method for treating complex aneurysms.

Intracranial-to-intracranial bypass for posterior inferior cerebellar artery aneurysms: options, technical challenges, and results in 35 patients

OBJECT Intracranial-to-intracranial (IC-IC) bypasses are alternatives to traditional extracranial-to-intracranial (EC-IC) bypasses to reanastomose parent arteries, reimplant efferent branches, revascularize branches with in situ donor arteries, and reconstruct bifurcations with interposition grafts that are entirely intracranial. These bypasses represent an evolution in bypass surgery from using scalp arteries and remote donor sites toward a more local and reconstructive approach. IC-IC bypass can be utilized preferentially when revascularization is needed in the management of complex aneurysms. Experiences using IC-IC bypass, as applied to posterior inferior cerebellar artery (PICA) aneurysms in 35 patients, were reviewed. METHODS Patients with PICA aneurysms and vertebral artery (VA) aneurysms involving the PICA's origin were identified from a prospectively maintained database of the Vascular Neurosurgery Service, and patients who underwent bypass procedures for PICA revascularization were included. RESULTS During a 17-year period in which 129 PICA aneurysms in 125 patients were treated microsurgically, 35 IC-IC bypasses were performed as part of PICA aneurysm management, including in situ p3-p3 PICA-PICA bypass in 11 patients (31%), PICA reimplantation in 9 patients (26%), reanastomosis in 14 patients (40%), and 1 V3 VA-to-PICA bypass with an interposition graft (3%). All aneurysms were completely or nearly completely obliterated, 94% of bypasses were patent, 77% of patients were improved or unchanged after treatment, and good outcomes (modified Rankin Scale ≤ 2) were observed in 76% of patients. Two patients died expectantly. Ischemic complications were limited to 2 patients in whom the bypasses occluded, and permanent lower cranial nerve morbidity was limited to 3 patients and did not compromise independent function in any of the patients. CONCLUSIONS PICA aneurysms receive the application of IC-IC bypass better than any other aneurysm, with nearly one-quarter of all PICA aneurysms treated microsurgically at our center requiring bypass without a single EC-IC bypass. The selection of PICA bypass is almost algorithmic: trapped aneurysms at the PICA origin or p1 segment are revascularized with a PICA-PICA bypass, with PICA reimplantation as an alternative; trapped p2 segment aneurysms are reanastomosed, bypassed in situ, or reimplanted; distal p3 segment aneurysms are reanastomosed or revascularized with a PICA-PICA bypass; and aneurysms of the p4 segment that are too distal for PICA-PICA bypass are reanastomosed. Interposition grafts are reserved for when these 3 primary options are unsuitable. A constructive approach that preserves the PICA with direct clipping or replaces flow with a bypass when sacrificed should remain an alternative to deconstructive PICA occlusion and endovascular coiling when complete aneurysm occlusion is unlikely.

Multiple reimplantation technique for treatment of complex giant aneurysms of the middle cerebral artery: technical note

BACKGROUND

Giant middle cerebral artery (MCA) aneurysms are among the most challenging neurovascular lesions, especially when the M2 and M3 branches are incorporated into the aneurysm. Here we report on two cases with complex MCA aneurysms, in which double and triple arterial reimplantation of the efferent vessels into a saphenous vein graft (SVG) was applied to reconstruct the MCA tree, allowing final trapping of the aneurysm.

METHODS

In the first case, a 41-year-old woman presented with a partially thrombosed giant MCA aneurysm including three efferent branches. Two superior trunks were disconnected and reimplanted onto an SVG fed by the external carotid artery (ECA). Following anastomosis between the SVG and the inferior trunk, the aneurysm was trapped. The second case is a 67-year-old man with recurrent giant MCA aneurysm incorporating two efferent M2 branches. First, the superior trunk was reimplanted onto an SVG, then the SVG was anastomosed to the inferior trunk. Finally the afferent M1 was clipped. Intraoperative indocyanine green (ICG) videoangiography (FLOW 800) was used for studying bypass patency.

RESULTS

In both cases, successful bypass patency was demonstrated by ICG videoangiography. Postoperative digital subtraction angiography (DSA) confirmed bypass patency. The first case was discharged without any neurological deficit. The second case suffered from bleeding due to refilling of the aneurysm via the inferior M2. An additional clip was placed on the inferior M2 in a second step. The patient was discharged with weakness of the left arm.

CONCLUSION

Reconstructing an MCA bifurcation or trifurcation combining multiple arterial reimplantation is effective for treatment of selective cases of complex MCA aneurysms.

Extracranial-Intracranial Bypass and Vessel Occlusion for the Treatment of Unclippable Giant Middle Cerebral Artery Aneurysms

BACKGROUND:

Giant middle cerebral artery (MCA) aneurysms pose management challenges.

OBJECTIVE:

To review the outcomes of patients with giant MCA aneurysms not amenable to clipping or vessel reconstruction treated with extracranial-intracranial (EC-IC) bypass and vessel sacrifice.

METHODS:

We retrospectively reviewed a database of aneurysms treated at our institution between 1983 and 2011.

RESULTS:

Sixteen patients (11 males, 5 females) were identified. There were 10 saccular, 4 fusiform, and 2 serpentine aneurysms. The aneurysms predominantly involved the M1 segment in 5 cases, M2 in 9 cases, and both M1 and M2 in 2 cases. The EC-IC bypasses performed included 13 superficial temporal artery-MCA, 1 saphenous vein graft-MCA, and 2 radial artery grafts-MCA. The postoperative bypass patency rate was 93.8% (15/16). There were 3 cerebrovascular accidents (18.8%), but no perioperative deaths (0% mortality). The mean follow-up was 58.4 months (range, 1-265; median, 23.5 months). In 75% (12/16) of cases the aneurysms were occluded successfully. A small residual was noted in 3 cases with the use of this treatment strategy, and they were re-treated. In a fourth case treated with partial distal occlusion, reduced flow through the aneurysm was noted postoperatively, but the patient did not undergo further treatment. The mean modified Rankin scale and mean Glasgow Outcome Scale scores at last follow-up were 1.6 (range, 1-4; median, 1) and 4.8 (range, 3-5; median, 5), respectively.

CONCLUSION:

Giant MCA aneurysms are challenging lesions. EC-IC bypass with parent vessel occlusion can provide a durable form of treatment with acceptable rates of morbidity and mortality.

Surgical strategies using cerebral revascularization in complex middle cerebral artery aneurysms

OBJECTIVES

To describe surgical strategies using cerebral revascularization for complex middle cerebral artery aneurysms unsuitable to microsurgical clipping.

MATERIALS AND METHODS

In this study, the clinical features, case management, and results in 9 consecutive patients who underwent 10 cerebral revascularization procedures between January 1999 and April 2008 were retrospectively analyzed. The patient population consisted of 6 men and 3 women whose ages ranged from 15 to 71 years (mean, 42.4 years). The size of the aneurysms ranged from 12 to 35 mm (mean, 24.3 mm). Treated aneurysms were located in the M1 segment in 2 patients, the middle cerebral artery (MCA) bifurcation in 3 patients, the distal M3 segment in 3 patients, and the anterior temporal artery (ATA; the early cortical branch of the M1 segment) in 1 patient. A total of 10 revascularizations were performed. Three aneurysms were saccular and six aneurysms were fusiform. For the fusiform aneurysms of the M1 segment in 2 patients, superficial temporal artery (STA) trunk-saphenous vein (SV)-MCA bypasses followed by trapping were performed. For the large saccular MCA bifurcation aneurysms in 3 patients, STA-MCA bypasses followed by complete neck clipping, including the revascularized branch with the preservation of the flow of the other branch, were performed in 2 cases, and a STA trunk-SV-MCA bypass secondary to direct neck clipping with the preservation of both M2 branches was performed in 1 case. For the fusiform distal MCA aneurysms, STA-MCA bypasses in 2 patients and in situ MCA-MCA bypasses in 2 patients were performed. In one case involving distal MCA fusiform aneurysm, STA-MCA bypass and MCA-MCA bypass were performed simultaneously. In a case involving fusiform ATA aneurysm, primary reanastomosis after aneurysm excision was performed in 1 patient.

RESULTS

The post-operative 3-month Glasgow outcome scales were good recovery in 6 patients, severe disability in 1 patient, a vegetative state in 1 patient, and death in 1 patient. A follow-up angiography was performed in 6 patients and revealed a patent bypass in 5 patients. In one case treated by direct neck clipping secondary to cerebral revascularization, the angiography obtained 2 weeks later showed graft occlusion, but there were no neurologic symptoms. Among the unfavorable outcomes of 3 patients who did not undergo follow-up angiography, surgery-related morbidity secondary to cerebral infarction was due to the size discrepancy between the donor and recipient vessels in 1 patient with severe disability. In the other 2 patients, the preoperative conditions were Hunt and Hess grade V.

CONCLUSIONS

Cerebral revascularization is a safe and effective technique of treatment for selective cases of complex large or giant aneurysms and unclippable fusiform aneurysms in the MCA.

Large distal anterior cerebral artery aneurysm treated with resection and interposition graft: case report

OBJECTIVE

Distal anterior cerebral artery (DACA) aneurysms are rare, representing only 2% to 6.7% of all intracranial aneurysms. Most of them are small. Large and giant aneurysms are even rarer in this location. Only 26 giant pericallosal (PC) aneurysms have been reported thus far. Various surgical techniques have been used to treat these aneurysms, including direct aneurysm neck clipping, aneurysm trapping, proximal occlusion of the anterior cerebral artery, or a combination of clipping with coiling or a bypass procedure. The report presents an unusual case of a complex DACA aneurysm managed by resection and interposition arterial graft.

CLINICAL PRESENTATION

A 69-year-old woman presented with acute onset of a severe headache. A digital subtraction angiogram showed a partially thrombosed, complex broad-necked A2-A3 junction aneurysm involving the origin of PC and callosomarginal vessels with a probability of a dissection of the DACA. The left PC artery was significantly narrowed. Because of the complex neck and involvement of the origin of PC and callosomarginal arteries, endovascular treatment was not possible, and microsurgical treatment was planned.

TECHNIQUE

A large, partially thrombosed, and fusiform anterior cerebral artery A2-A3 aneurysm, with evidence of previous bleeding, was found and treated with resection and a short interposition graft using a segment of the superficial temporal artery.

CONCLUSION

Surgical treatment of a large DACA aneurysm may be difficult due to a complex neck and the involvement of the branch vessels. Resection and interposition grafting and A3-A3 or A4-A4 anastomoses are treatment options for such patients.

Hemorrhagic cerebral dissecting aneurysms: surgical treatments and results

INTRODUCTION

Cerebral dissecting aneurysms are an increasingly recognized etiology of subarachnoid hemorrhage SAH and cerebral stroke. Hemorrhagic dissecting aneurysms of the anterior circulation have been considered to be somewhat different to those of the posterior circulation not only in terms of their pathophysiology, but also in terms of their management. Herewith our series of hemorrhagic dissecting aneurysms of the internal carotid artery ICA, vertebral artery VA, basilar artery BA and some of those of distal cerebral arteries is presented and compared to the series reported in the literature. Therapeutic consideration in the light of our experiences emphasizing the significance of aneurysm entrapment in combination with bypass surgery is presented.

MATERIAL AND METHODS

During the last 13 years over 1000 patients with cerebral aneurysms were treated surgically in our department. Hemorrhagic dissecting aneurysms were diagnosed in 26 patients. Diagnosis was based on neuroradiological findings as well as intraoperative findings. All patients underwent surgical intervention. Clinical findings of these patients were analysed retrospectively. Follow-up outcomes were evaluated according to the Glasgow Outcome Scale GOS at 3 months after treatments.

RESULTS

Location of 26 dissecting aneurysms was: ICA 11 cases (42%), VA 9 cases (35%), BA 3 cases, MCA 2 cases and PCA (P1 segment) one case. Primary surgical treatments were performed on day 3.7 of SAH on average. Clinical manifestation of dissecting aneurysms of the ICA and their outcome was more severe compared with those of the VA (p < 0.01): WNFS grade 3.1 vs 2.4 and GOS score 3.4 vs 4.3. As a conventional neck clipping procedure was problematic or impossible (aneurysm recurrence after clipping, premature rupture at the time of exposure or clipping), entrapment (or proximal ligation) plus EC-IC bypass procedure was the most frequent final definitive method of surgical treatment (9/26 35%: ICA 6/11, VA 1/9 and MCA 2/2) followed by proximal ligation or trapping only 7/26, neck clipping 7/26 and coating 4/26.

CONCLUSIONS

Hemorrhagic dissecting aneurysms still remain problematic in their diagnosis and treatment. One has to be aware of the diagnostic possibility of dissecting aneurysms as an etiology of SAH. Neurosurgeons have to be prepared to be able to manage complex surgical situations also by the use of EC-IC bypass, as its combination with entrapment procedure can be the final treatment of choice. Less invasive endovascular technique is in evolution but its availability and superiority are still to be settled.

Revascularization with saphenous vein bypasses for complex intracranial aneurysms

Most intracranial aneurysms can be managed with either microsurgical clipping or endovascular coiling. A subset of complex aneurysms with aberrant anatomy or fusiform/dolichoectatic morphology may require revascularization as part of a strategy that occludes the aneurysm or parent artery or both. Bypass techniques have been invented to revascularize nearly every intracranial artery. An aneurysm that will require a saphenous vein bypass is one that cannot be treated with conventional microsurgical clipping or endovascular coiling and also requires deliberate sacrifice of a major intracranial artery as part of the alternative treatment strategy. In the past 7 years the senior author (MTL) has performed a total of 110 bypasses, of which 46 were for aneurysms. Twenty-two of these patients received high-flow extracranial-to-intracranial bypasses using saphenous vein grafts, of which 16 had aneurysms that were giant in size. We review the indications for saphenous vein bypasses for complex intracranial aneurysms, surgical techniques, and clinical management strategies.

Thrombotic Intracranial Aneurysms: Classification Scheme and Management Strategies in 68 Patients

OBJECTIVE:

Thrombotic aneurysms are a diverse collection of complex aneurysms characterized by organized intraluminal thrombus and solid mass. Consequently, their treatment often requires techniques other than conventional clipping, such as thrombectomy with clip reconstruction or bypass with parent artery occlusion. A single-surgeon experience with thrombotic aneurysms was analyzed to determine optimal treatment strategies. A classification scheme was devised on the basis of aneurysm, thrombus, and lumen morphology to relate these anatomic features to surgical therapy.

METHODS:

Sixty-eight patients with thrombotic aneurysms were managed during a period of 6.25 years. Thrombotic aneurysms were classified into six types: concentric (n = 17, 25%), eccentric (n = 14, 21%), lobulated (n = 2, 3%), complete (n = 2, 3%), canalized (n = 17, 25%), and coiled (n = 16, 24%).

RESULTS:

Aneurysm management consisted of direct clipping (n = 22, 32%), thrombectomy-clip reconstruction (n = 18, 26%), bypass-occlusion (n = 20, 29%), other (n = 6, 9%), or observation (n = 2, 3%). Complete angiographic obliteration was achieved in 97% of patients, and 47% of aneurysms were thrombectomized. The surgical mortality rate was 6%, and the permanent neurological morbidity rate was 7%. Overall, 87% of patients were improved or unchanged at follow-up, with 79% reaching a Glasgow Outcome Scale score of 5 or 4. Management strategy was influenced by thrombotic aneurysm type, but patient outcome was not. The best results were observed in patients treated with direct clipping and bypass-occlusion.

CONCLUSION:

Despite their solid mass, one-third of thrombotic aneurysms can be treated surgically with conventional clipping. Direct clipping is associated with the best surgical results, and the proposed classification scheme identifies thrombotic aneurysms that may be clippable. Patients with unclippable thrombotic aneurysms had more favorable results when treated with bypass and aneurysm occlusion than with thrombectomy and clip reconstruction. The classification scheme may provide conceptual clarity and therapeutic guidance with preoperative and intraoperative decision making.

Ruptured traumatic vertebral artery pseudoaneurysm in a child treated with trapping and posterior inferior cerebellar artery reimplantation

The authors present the case report of a pediatric patient with a ruptured traumatic pseudoaneurysm of the intracranial vertebral artery (VA) from which the posterior inferior cerebellar artery (PICA) emerged. After considering multiple therapeutic options, the patient was treated surgically by trapping of the aneurysm segment and direct reimplantation of the PICA distal to the rupture site. In addition to presenting this unique case, the authors discuss the treatment of VA pseudoaneurysms and the various techniques for PICA revascularization. A review of the literature on PICA reimplantation is provided as an adjunct in the treatment of complex VA aneurysms.

Surgical Management of Fusiform Aneurysms of the Peripheral Posteroinferior Cerebellar Artery

OBJECTIVE

To describe the management and outcomes of seven patients with fusiform aneurysms of the peripheral posteroinferior cerebellar artery (PICA).

METHODS

Medical records and neuroimaging studies of seven patients who underwent surgical treatment of fusiform aneurysms of the peripheral PICA were reviewed. Average follow-up time was 1.5 years, and no patient was lost to follow-up.

RESULTS

All patients presented with acute subarachnoid hemorrhage, and most had acute hydrocephalus. All underwent surgery, which entailed distal revascularization in six of the seven patients. Revascularization techniques included occipital artery–PICA bypass, side-to-side PICA-PICA anastomosis, and aneurysm excision with direct end-to-end PICA reanastomosis. Outcome was good in six patients and fair in one.

CONCLUSION

Fusiform, peripheral PICA aneurysms are rare lesions. Distal revascularization was used in most cases because of the uncertain adequacy of collateral supply. Careful, individualized management allows for a good outcome in the majority of cases.

Spontaneous fusiform middle cerebral artery aneurysms: characteristics and a proposed mechanism of formation

OBJECT

The goal of this study was to identify the origins of spontaneous fusiform middle cerebral artery (MCA) aneurysms.

METHODS

One hundred two cases of spontaneous fusiform MCA aneurysms were reviewed, including 40 from the authors' institutions and 62 identified from the literature. The mean age at symptom onset was 38 years, and the male/female ratio was 1.4:1. At presentation, the MCA lumen was stenosed or occluded in 12 patients, focally dilated in 57, and appeared "serpentine" in 33. Most lesions originated from the M1 or M2 segments, and most (80%) presented with nonhemorrhagic symptoms or were discovered incidentally. The presenting clinical features correlated with morphological findings in the aneurysms, which could be observed to progress from a small focal dilation or vessel narrowing to a serpentine channel. Hemorrhage was the most common presentation in small lesions; the incidence of bleeding progressively diminished with larger lesions. Patients with stenoses or occluded vessels most often presented with ischemic symptoms, and occasionally with hemorrhage. Giant focal dilations or serpentine aneurysms were rarely associated with acute bleeding; clinical presentation was most often prompted by mass effect or thromboembolic stroke.

CONCLUSIONS

Analysis of results after various treatments indicates that for symptomatic lesions, therapies that reverse intraaneurysmal blood flow and augment distal cerebral perfusion are associated with better outcomes than other strategies, including conservative management. Based on the spectrum of clinical, pathological, neuroimaging, and intraoperative findings, dissection is proposed as the underlying cause of these lesions.

Isolated dissections and dissecting aneurysms of the posterior inferior cerebellar artery: topic and literature review

Isolated dissections of the posterior inferior cerebellar artery (PICA) are rare. Thus, no large series of cases have been reported in the literature. Due to limited knowledge regarding the natural history of these lesions and the lack of high-quality evidence supporting various treatment options, management is controversial and practice parameters are ill defined. In order to offer a comprehensive reference for the diagnosis and management of isolated PICA dissections, the authors reviewed the National Library of Medicine from 1966 to October 2001. Twenty-seven patients averaging 43.6 years of age and including 14 males and 13 females were reported. Subarachnoid hemorrhage occurred in 20 patients, and two died. Dissections were located in the proximal PICA in 22 patients and were three times more common on the left side (left:right=3:1). Six patients were managed conservatively, and four with endovascular techniques. Seventeen had open surgery: five underwent resection, two went through trapping, and two had proximal clipping. Wrapping with muscle was performed in two patients, encasement with Sundt clips in two, and four had occipital artery (OA)-PICA bypass surgery. A meticulous analysis of reported cases with regard to clinical and pathological features, management strategies, and outcomes is presented.

Ruptured Infectious Aneurysm of the Distal Middle Cerebral Artery Manifesting as Intracerebral Hemorrhage and Acute Subdural Hematoma-Case Report-

A 21-year-old woman with severe mitral valve regurgitation due to infectious endocarditis was transferred to our institute in a deep coma with intracerebral hemorrhage and acute subdural hematoma. She had no history of head injury. Brain computed tomography revealed left frontoparietal intracerebral hematoma and adjacent acute subdural hematoma that were evacuated on the day of admission, but the distal middle cerebral artery (MCA) aneurysm remained undetected. Follow-up cerebral angiography demonstrated the distal MCA aneurysm, which had enlarged by 25% at 2 weeks following the first operation. The aneurysm originated from a branch of the angular artery and was successfully resected on Day 22. Histological examination of the aneurysm section showed no infectious nature, but the final diagnosis was infectious intracranial aneurysm based on the presence of infectious endocarditis.

Distal anterior inferior cerebellar artery aneurysms. Report of four cases

Aneurysms of the distal anterior inferior cerebellar artery (AICA) are rare; fewer than 100 cases have been reported. The authors detail their experience with four cases and present endovascular as well as microsurgical management options. The medical records and neuroimaging studies obtained in four patients who were treated at a single institution were reviewed. Clinical presentations, neuroimaging and intraoperative findings, and clinical outcomes were analyzed. There were three men and one woman; their mean age was 43 years. Two patients presented with acute subarachnoid hemorrhage (SAH), and two presented with ataxia and vertigo (one with tinnitus, the other with hearing loss). Angiographic studies demonstrated aneurysms of the distal segment of the AICA. In one patient with von Hippel-Lindau syndrome and multiple cerebellar hemangioblastomas, a feeding artery aneurysm was found on a distal branch of the AICA. Three of the patients underwent successful surgical obliteration of their aneurysms, one by clipping, one by trapping, and one by resection along with the tumor. The fourth patient underwent coil embolization of the distal AICA and the aneurysm. All patients made an excellent neurological recovery. Patients with aneurysms in this location may present with typical features of an acute SAH or with symptoms referable to the cerebellopontine angle. Evaluation with computerized tomography, magnetic resonance (MR) imaging, MR angiography, and digital subtraction angiography should be performed. For lesions distal to branches coursing to the brainstem, trapping and aneurysm resection are viable options that do not require bypass. Endovascular obliteration is also a reasonable option, although the possibility of retrograde thrombosis of the AICA is a concern.

Intracranial-to-intracranial vascular anastomosis created using a microanastomotic device for the treatment of distal middle cerebral artery aneurysms. Technical note

The use of a microanastomotic device for direct connection of intracranial vessels can be helpful to facilitate removal of distally located middle cerebral artery (MCA) aneurysms. The authors report on two patients who presented for treatment with large aneurysms distally located on the MCA. The aneurysms were completely excised and the proximal and distal portions of the parent vessel were connected in an end-to-end fashion by using a microanastomotic device. The time required to crossclamp the vessel for excision of the aneurysm and primary anastomosis was 10 minutes in one case and 15 minutes in the other. The short crossclamp time and high-quality anastomosis afforded by this device may be useful in the treatment of these difficult lesions and the prevention of cerebral ischemia.

Trapping and revascularization for a dissecting aneurysm of the proximal posteroinferior cerebellar artery: technical case report and review of the literature

OBJECTIVE AND IMPORTANCE

Subarachnoid hemorrhage caused by an isolated dissection of the proximal portion of the posteroinferior cerebellar artery (PICA) is a rare problem. The optimal treatment to use for patients presenting with this clinical scenario varies and therefore is controversial in the literature. We report a patient in whom this problem was treated effectively with trapping of the diseased segment and revascularization of the PICA. We report this case to review this rare topic and to present our perspective on the indications for and the effectiveness of trapping and revascularization for proximal PICA dissections that cause hemorrhage.

CLINICAL PRESENTATION

A 55-year-old man was transferred to our institution and admitted for Hunt and Hess Grade IV subarachnoid hemorrhage, which improved to Hunt and Hess Grade III after ventricular drainage. Imaging revealed the source of the hemorrhage to be a pseudoaneurysm related to the dissection of the proximal portion of the PICA.

INTERVENTION

Three days after the initial bleeding episode, we operated on the patient. After the occipital artery was prepared for bypass, the diseased segment was trapped. The occipital artery-to-PICA anastomosis was then immediately performed distal to the trapped segment.

CONCLUSION

On the basis of our experience, the literature regarding this topic, and the anatomy of the perforators of the PICA, we think that the best treatment for a pseudoaneurysm located within the first three segments of the PICA is trapping of the diseased segment followed by revascularization distal to the trapped segment. This approach should prevent rehemorrhage and should avoid iatrogenic ischemic complications of the brainstem.

Middle cerebral artery dissecting aneurysm causing intracerebral hemorrhage 4 years after the non-hemorrhagic onset: a case report

BACKGROUND

We report a case of dissecting middle cerebral artery (MCA) aneurysm causing intracerebral hemorrhage 4 years after the non-hemorrhagic onset.

CASE DESCRIPTION

A 30-year-old male was diagnosed with an unruptured dissecting MCA aneurysm after a severe pulsating headache in August 1993. Angiography revealed dilatation of the distal portion of the temporo-occipital artery. During 2 years of follow-up, there were no significant changes on magnetic resonance imaging. In August 1997, he became comatose because of massive intracerebral hemorrhage caused by a dilated fusiform dissecting aneurysm. Emergency surgery and postoperative mild hypothermia resulted in full recovery.

CONCLUSION

To date only 30 cases of dissecting MCA aneurysm have been reported and for unruptured aneurysms, surgical intervention was not chosen. However, the present case strongly suggests that long-term follow-up is necessary in patients with unruptured dissecting aneurysms of the anterior circulation, especially those with ectatic components.

Extracranial-intracranial vein graft bypass for giant intracranial aneurysm surgery for pediatric patients: two technical case reports

OBJECTIVE AND IMPORTANCE

Herein we describe two cases of extracranial-intracranial vein graft bypasses for the treatment of giant intracranial aneurysms in prepubertal pediatric patients. One patient is, we think, the youngest patient reported in the literature to have been successfully treated in such a manner, with a good long-term outcome. Such grafts seem to enlarge longitudinally during the growth spurt, making such techniques reasonable long-term therapeutic options for the management of complex intracranial aneurysms in pediatric patients.

CLINICAL PRESENTATION

Patient 1, a 13-year-old boy, presented with headaches and rapidly progressive right cavernous sinus syndrome. Computed tomography and cerebral angiography revealed a giant, fusiform, right intracavernous internal carotid artery aneurysm. Patient 2, a 23-month-old girl, was discovered to harbor an asymptomatic, recurrent, giant, fusiform, left M1 middle cerebral artery aneurysm 1 year after presenting with seizures related to subarachnoid hemorrhage from the aneurysm, for which she had been treated with clipping and an M2-M2 anastomosis.

INTERVENTION

Both patients underwent craniotomies, with sacrifice of the proximal parent vessel (the distal cervical internal carotid artery and the proximal middle cerebral artery, respectively), combined with cerebral revascularization through extracranial-intracranial saphenous vein bypass grafts. Both patients experienced excellent long-term clinical outcomes, have undergone significant growth, and exhibit excellent long-term graft patency and aneurysm obliteration.

CONCLUSION

These two cases highlight the safety and efficacy of extracranial-intracranial vein graft bypasses among prepubertal pediatric patients. The indications for bypass procedures to treat giant intracranial aneurysms are discussed, and the technical aspects of maximizing vein bypass graft patency are reviewed.

Cerebral revascularization for aneurysms and tumors

OBJECTIVE

To discuss the indications, techniques, pitfalls, complication avoidance, and management of cerebral revascularization techniques for the treatment of aneurysms and cranial base tumors.

METHODS

The indications for cerebral revascularization procedures included microsurgical occlusion of a parent vessel during the treatment of aneurysms and occlusion of a major vessel during the treatment of basal tumors. The techniques discussed include arterial patch grafting, end-to-end anastomosis, side-to-side anastomosis, arterial interposition grafting, and extracranial-to-intracranial bypass grafting, using radial artery grafts or saphenous vein grafts.

RESULTS

During the 15-year period between 1985 and 2000, the senior author performed 24 radial artery grafts, 105 saphenous vein grafts, and 8 other revascularization procedures, among 50 patients with aneurysms and 83 patients with cranial base tumors. The overall patency rate was 95.6%. Twenty-three patients experienced a cerebral infarction; among those patients, 17 (12.5%) exhibited symptoms but the majority demonstrated considerable recovery during the follow-up period. One hundred one patients recovered to an excellent (Glasgow Outcome Scale score of 5) or good (Glasgow Outcome Scale score of 4) condition. Fifteen patients died as a result of recurrence or progression of tumors during the follow-up period. There were five perioperative deaths. For the last 35 patients, the surgical mortality rate was 0%, with all patients returning to an excellent or good condition.

CONCLUSION

Although highly specialized, these sophisticated cerebral revascularization techniques should be learned and practiced by all neurosurgeons who wish to microsurgically treat intracranial aneurysms or cranial base tumors.

[Subarachnoid hemorrhage secondary to dissecting aneurysms of the vertebral artery. Description of 2 cases and review of the literature]

OBJECTIVES AND INTRODUCTION: The pathogenesis and natural history of intracranial vertebral artery dissection remain uncertain up to now due in part to its relative rarity. In this article we review the state of the art of this process and remark the good outcome obtained with embolization using Guglielmi detachable coiling (GDC).

METHODS

Two cases with subarachnoid hemorrhage secondary to rupture of a vertebral dissection aneurysms are described. The first patient initially suffered brain stem infarction, followed by a subarachnoid hemorrhage a year later. The second patient who had a severe subarachnoid hemorrhage with two early rebleedings was successfully treated with embolization using GDC.

CONCLUSIONS

Subarachnoid hemorrhage due to rupture of vertebral dissecting aneurysm is a relatively unknown disease with some important aspects that should be known. The high incidence of early rebleeding (up to 60%), makes early diagnosis and treatment important goals. Classically the preferred treatment has been proximal vertebral artery occlusion. However, the recent introduction of embolization with GDC has made possible the occlusion of the dissection with very good final outcome.

Long-term patency of radial artery graft bypass for reconstruction of the internal carotid artery. Technical note

Reconstruction of the carotid artery by using a radial artery graft is a useful option that can produce reliable long-term patency for the surgical treatment of giant and/or large aneurysms of the cavernous and paraclinoid internal carotid artery (ICA). During the past 10 years, 43 patients with intracavernous and paraclinoid giant aneurysms of the ICA have been treated by reconstruction of the ICA with radial artery grafts after ligation of the cervical ICA. The long-term patency of the grafted radial artery was evaluated over more than a 5-year period (mean 7.2 years) in 20 of these patients by using magnetic resonance angiography or conventional angiography. There was no late occlusion of the graft in any of these cases. Stenotic graft changes were observed in two cases.

Intracranial vascular anastomosis using the microanastomotic system. Technical note

The authors describe the use of a microanastomotic device to perform intracranial end-to-end vascular anastomoses. Direct end-to-end anastomosis was performed between the superficial temporal artery and branches of the middle cerebral artery (MCA) in three patients. Two patients had moyamoya disease, with severe proximal MCA disease, and one suffered an internal carotid artery occlusion with poor collateral flow. All patients reported a history of recent ischemic symptoms. Each anastomosis was accomplished in less than 15 minutes with technically satisfactory results. Postoperative angiographic studies demonstrated patency of the bypasses in all patients.

Vascular reconstruction using interposed small vessels

OBJECTIVE

This study presents the relationship between the patency of short-vessel graft bypasses and their diameter/length.

METHODS

The authors performed interposed graft bypass operations using small vessels for four patients with moyamoya disease, six patients with cerebral thrombosis, and one patient with aortitis syndrome. The donor artery was the superficial temporal artery (10 patients) or the occipital artery (1 patient), and the recipient artery was the cortical branch of the middle cerebral artery (8 patients) or the cortical branch of the anterior cerebral artery (3 patients). The interposed graft used between these donor and recipient vessels was the superficial temporal vein (seven patients), the superficial temporal artery (three patients), or the epigastric artery (one patient).

RESULTS

Good patency of the graft was confirmed for 7 of these 11 patients. Regarding the relationship between the diameter/length and the patency, we found that long-term patency could not be expected when the discriminant function of y = (15.39 x diameter) - (0.35 x length) - 14.37 was below zero.

CONCLUSION

Short-vessel graft bypass is a practical option for cerebral revascularization surgery when short large vessels are used.

A dissecting aneurysm of the posteroinferior cerebellar artery: case report

OBJECTIVE AND IMPORTANCE

We present a patient who experienced a subarachnoid hemorrhage secondary to a dissecting aneurysm of the right posteroinferior cerebellar artery (PICA). The use of an encircling clip in treating the aneurysm while preserving supply to brain stem perforators originating near the dissecting segment and the distal PICA territory was key in the operative management.

CLINICAL PRESENTATION

A 48-year-old patient with a history of hypertension presented with subarachnoid hemorrhage confirmed by computed tomography of the brain. Successive cerebral angiography revealed a dynamic change in the configuration of the dissection, with expansion of the associated focal ectasia.

OPERATIVE MANAGEMENT

At surgery, three brain stem perforators adjacent to the aneurysm were visualized. The dissecting segment was reconstructed with an encircling Sundt clip and muslin wrap, which preserved the flow through the PICA and brain stem perforators.

CONCLUSION

A patient suffering from a dissecting PICA aneurysm and subarachnoid hemorrhage was successfully treated with direct surgical reconstruction of the parent artery, sparing the perforators to the medulla.

Extradural origin of the posteroinferior cerebellar artery: an anatomic study with histological and radiographic correlation

OBJECTIVE

The posteroinferior cerebellar artery (PICA) usually arises from the intradural segment of the vertebral artery (VA). The extradural origin of the PICA is infrequent. Its preoperatory identification is important in surgical strategy during the exposure of the VA.

METHODS

During an anatomic prosection, the VA was exposed at the craniocervical junction in cadaveric adult specimens. The extradural origin of the PICA was encountered bilaterally in one specimen and on one side in a second specimen. An anatomic study with histological and radiographic correlation was performed.

RESULTS

Perforating branches originate from the PICA. They supply the middle and inferior third of the olive and the lateral aspect of the medulla. The PICA has cortical branches that lead to the cerebellum. Injury to the PICA can produce an infarction of these neural structures that can be asymptomatic or cause major neurological deficits. Radiographic results obtained using a lateral projection provided the most reliable delineation of the extradural origin of the PICA. When this artery originates at, or posterior to, the posterior aspect of the occipital condyle, an extradural origin is likely.

CONCLUSION

Bilateral selective vertebral angiography should be performed with special attention to the relationships of PICA origins before any surgical exposure of the VA at the craniocervical junction, unless magnetic resonance angiography provides this information without question. A thorough understanding of the relative dominance of the VAs and PICAs, the location of the PICA origin, and the collateral circulation of the posterior fossa are prerequisites to surgery in this region. The preoperative identification of an extradural PICA is important in planning surgical strategy and in avoiding complications during operations near the foramen magnum.