Revascularization and aneurysm surgery: current techniques, indications, and outcome

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.

Cerebral revascularization in skull base tumors

Skull base tumors involving the carotid artery pose a difficult surgical challenge. The potential for bypass grafting for cerebral revascularization carries inherent risks but may aid in tumor resection and control in those who warrant carotid sacrifice but have inappropriate natural cerebrovascular reserve. We include a review of the literature discussing the indications for carotid resection as part of skull base tumor surgery, indications for cerebral revascularization, balloon test occlusion, graft types and operative technique, complications, and results.

ELANA: Excimer Laser-Assisted Nonocclusive Anastomosis for extracranial-to-intracranial and intracranial-to-intracranial bypass: a review

ELANA, excimer laser-assisted nonocclusive anastomosis, is a technique using an excimer laser/catheter system for intracranial bypass surgery of the brain. The technique has been developed over the past 12 years by Tulleken and colleagues at UMC Utrecht in The Netherlands for treatment of primarily untreatable giant aneurysms. We review here the emergence of transplanted conduit bypass as a valuable technique for managing these lesions and the subsequent development of ELANA bypass. The ELANA technique allows the operating surgeon to perform an extracranial-to-intracranial or intracranial-to-intracranial bypass using a transplanted large caliber conduit without occlusion of the recipient artery, thus eliminating intraoperative ischemic insult related to temporary occlusion time. We describe the ELANA technique, illustrate it with intraoperative photos, and review the relevant literature. ELANA is shown to be safe; we discuss its advantages over conventional techniques.

Skull base approaches to the basilar artery

Posterior circulation lesions constitute approximately 10% of all intracranial aneurysms. Their distribution includes the basilar artery (BA) bifurcation, superior cerebellar artery, posterior inferior cerebellar artery, and anterior inferior cerebellar artery. The specific features of a patient's aneurysm and superb anatomical knowledge help the surgeon to choose the most appropriate approach and to tailor it to the patient's situation. The main principle that must be applied is maximization of bone resection. This allows the surgeon to work within a wider corridor, which facilitates the use of surgical instruments and minimizes retraction of the brain.

The management of aneurysms within the posterior circulation requires expertise in skull base and vascular surgery. Endovascular treatments have become increasingly important, but in this paper the authors focus on the surgical management of these difficult aneurysms. The paper is divided into three parts: the first section is a brief review of the anatomy of the BA; the second part is a review of the techniques associated with the management of posterior fossa aneurysms; and in the third section the authors describe the different approaches, their nuances and indications based on the location of the aneurysm, and its relationship to the surrounding bone (especially the clivus, dorsum sellae, and the free edge of the petrous apex).

In Situ Bypass in the Management of Complex Intracranial Aneurysms: Technique Application in 13 Patients

OBJECTIVE:

Cerebral revascularization is an important part of the treatment of complex intracranial aneurysms that require deliberate occlusion of a parent artery. In situ bypass brings together intracranial donor and recipient arteries that lie parallel and in close proximity to one another rather than using an extracranial donor artery. An experience with in situ bypasses was retrospectively reviewed.

METHODS:

Thirteen aneurysms were treated with in situ bypasses between 1997 and 2004. During this time, 1071 aneurysms were treated microsurgically and 46 bypasses were performed as part of the aneurysm treatment.

RESULTS:

Treated aneurysms were located at the middle cerebral artery (MCA) in five patients, posteroinferior cerebellar artery (PICA) in three patients, vertebral artery in three patients, and anterior communicating artery in two patients. Seven aneurysms were fusiform or dolichoectatic, and six aneurysms were saccular. Microsurgical revascularization techniques included side-to-side anastomosis of intracranial arteries in eight patients and aneurysm excision with end-to-end reanastomosis of the parent artery in five patients. In situ bypasses included A3–A3 anterior cerebral artery bypass in two patients, anterior temporal artery-MCA bypass in one patient, MCA–MCA bypass in one patient, and PICA–PICA bypass in four patients. Aneurysm excision with arterial reanastomosis included three MCA aneurysms and two PICA aneurysms. On angiography, all aneurysms were completely obliterated and 12 bypasses were patent.

CONCLUSION:

In situ bypass is a safe and effective alternative to extracranial-intracranial bypasses and high-flow bypasses using saphenous vein or radial artery grafts. Although in situ bypasses are more demanding technically, they do not require harvesting a donor artery, can be accomplished with one anastomosis, and are less vulnerable to injury or occlusion.

Recommendations for Comprehensive Stroke Centers

Background and Purpose— To develop recommendations for the establishment of comprehensive stroke centers capable of delivering the full spectrum of care to seriously ill patients with stroke and cerebrovascular disease. Recommendations were developed by members of the Brain Attack Coalition (BAC), which is a multidisciplinary group of members from major professional organizations involved with the care of patients with stroke and cerebrovascular disease.

Summary of Review— A comprehensive literature search was conducted from 1966 through December 2004 using Medline and Pub Med. Articles with information about clinical trials, meta-analyses, care guidelines, scientific guidelines, and other relevant clinical and research reports were examined and graded using established evidence-based medicine approaches for therapeutic and diagnostic modalities. Evidence was also obtained from a questionnaire survey sent to leaders in cerebrovascular disease. Members of BAC reviewed literature related to their field and graded the scientific evidence on the various diagnostic and treatment modalities for stroke. Input was obtained from the organizations represented by BAC. BAC met on several occasions to review each specific recommendation and reach a consensus about its importance in light of other medical, logistical, and financial factors.

Conclusions— There are a number of key areas supported by evidence-based medicine that are important for a comprehensive stroke center and its ability to deliver the wide variety of specialized care needed by patients with serious cerebrovascular disease. These areas include: (1) health care personnel with specific expertise in a number of disciplines, including neurosurgery and vascular neurology; (2) advanced neuroimaging capabilities such as MRI and various types of cerebral angiography; (3) surgical and endovascular techniques, including clipping and coiling of intracranial aneurysms, carotid endarterectomy, and intra-arterial thrombolytic therapy; and (4) other specific infrastructure and programmatic elements such as an intensive care unit and a stroke registry. Integration of these elements into a coordinated hospital-based program or system is likely to improve outcomes of patients with strokes and complex cerebrovascular disease who require the services of a comprehensive stroke center.

Management of the internal carotid artery in tumors of the lateral skull base: preoperative permanent balloon occlusion without reconstruction

OBJECTIVE

To present our experience with permanent preoperative balloon occlusion of the internal carotid artery while dealing with different abnormalities of the lateral skull base and a comparison with the results mentioned in the literature.

STUDY DESIGN

Retrospective case review.

SETTING

Private neurotologic and skull base tertiary referral center.

PATIENTS

Fifteen patients who underwent preoperative balloon occlusion of the internal carotid artery and surgery subsequently for various abnormalities of the lateral skull base between 1989 and 2002.

INTERVENTIONS

Each patient was subjected to four-vessel angiography along with the manual cross-compression test and balloon test occlusion to assess the efficacy of the collateral circulation. After angiography, each patient underwent a preoperative balloon occlusion, after which a lateral skull base procedure was performed for removal of the abnormality.

MAIN OUTCOME MEASURES

Only those patients showing evidence of adequate collateral cerebral circulation and a less than 1-second delay between the angiographic phases of the two cerebral hemispheres on angiography were considered fit for preoperative balloon occlusion. While under going the preoperative balloon occlusion, the patients were clinically assessed for the development of any neurologic symptoms and signs. Long-term follow-up after surgery was also based on the development of symptoms and signs of neurovascular compromise.

RESULTS

A major complication in the form of long-lasting hemiplegia occurred in one patient (6.7%). This complication was the result of technical factors rather than an effect of cerebral ischemia, because it was caused by an intimal dissection produced by the catheter. A defect in the visual field occurred in one patient (6.7%) that resolved partially after antiplatelet therapy. There was no mortality in our series related to preoperative balloon occlusion of the internal carotid artery.

CONCLUSION

Preoperative balloon occlusion of the internal carotid artery can still be considered a viable option for the management of the internal carotid artery during lateral skull base surgery. Proper preoperative evaluation of the adequacy and efficacy of the collateral cerebral circulation reduces the chances of postoperative neurovascular complications.

Experience from "double-insurance bypass." Surgical results and additional techniques to achieve complex aneurysm surgery in a safer manner

BACKGROUND

"Double-insurance bypass" was recently advocated to avoid the risk of cerebral ischemia during prolonged temporary occlusion of the carotid artery. For large aneurysms needing temporary but prolonged obliteration of the internal carotid artery (ICA). We have attempted the double-insurance bypass in 15 patients and, herein, report the efficacies and limitations of the procedure, and surgical techniques to make this procedure safer.

METHODS

We treated 15 patients with complex internal carotid aneurysms by clipping surgery with the aid of radial artery (RA) to proximal middle cerebral artery (MCA) bypass, so-called double-insurance bypass. We analyzed surgical results of the procedure.

RESULTS

In 11 patients, the duration of temporary occlusion of the ICA could be prolonged for as long as 110 minutes (mean, 45 minutes) without any ischemic complications. One patient in the earlier period of our experience suffered extended cerebral infarction due to possible restricted blood flow through the RA, because the brachial artery was compressed by the firm shoulder joint and neighboring structures. Thereafter, we routinely monitored the blood pressure of MCA (MCABP) and never experienced such cortical infarctions. Another 3 patients, however, experienced ischemia in the territory of perforating arteries that originated from a segment that could not be perfused by the RA-MCA bypass.

CONCLUSIONS

In combination with monitoring of MCABP, the double-insurance bypass can be a safer and more potent adjunctive procedure for the treatment of complex internal carotid aneurysms which require prolonged temporary occlusion of the ICA.

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.

Late morphological progression of a dissecting basilar artery aneurysm after staged bilateral vertebral artery occlusion: case report

BACKGROUND

The authors present a patient who experienced late (5-year follow-up) morphological progression of a dissecting aneurysm of the distal basilar artery after treatment with a combined microsurgical and neuroendovascular Hunterian strategy. In addition to postulating about the possible reasons underlying the evolution of this lesion, the role of stenting is discussed.

CASE DESCRIPTION

The patient was 37 years old when she suffered a subarachnoid hemorrhage from spontaneous basilar artery dissection. At the time of the hemorrhage, minimal aneurysmal enlargement was noted angiographically, and she was therefore treated nonoperatively. On reimaging 5 months later, massive enlargement of the aneurysm was noted. The patient was treated with staged bilateral vertebral artery sacrifice using a combination of microsurgical and neuroendovascular techniques. The dominant vertebral artery was clip-ligated distal to the posteroinferior cerebellar artery, whereas the contralateral vertebral artery was coil-occluded cervically 1 week later.

CONCLUSIONS

Despite the patient remaining asymptomatic, follow-up angiography 5 years after the initial hemorrhage revealed further enlargement of the aneurysm as well as a newly discovered inferiorly projecting daughter sac measuring 5 mm in diameter. Clearly, certain aneurysms exist for which indirect approaches involving hemodynamic attenuation fail to prevent progression. With greater refinements in stent technology, such lesions may be more effectively treated.

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.

Combined surgical and endovascular treatment of a recurrent A3–A3 junction aneurysm unsuitable for standalone clip ligation or coil occlusion

Recurrent aneurysms of the anterior circulation that are distal to the anterior communicating artery (ACoA) but proximal to the callosomarginal–pericallosal bifurcation can pose a treatment challenge. The authors present one such case, in which the patient was treated with pericallosal artery–pericallosal artery (PerA–PerA) side-to-side bypass, followed by endovascular obliteration of the proximal A2 parent vessel. This patient, in whom an ACoA aneurysm had been treated with clip ligation 5 years previously, presented with a new, mid-A2, right-sided aneurysm with the out-flow artery arising from the dome of the lesion.

The treatment plan included two steps: an interhemispheric transcallosal approach for PerA–PerA side-to-side anastomosis; and endovascular coil embolization of the right A2 branch feeding the aneurysm. Postprocedure angiography demonstrated no ipsilateral aneurysm filling and excellent bilateral distal outflow from the anterior cerebral artery (ACA).

The use of PerA–PerA side-to-side bypass for the treatment of an ACA aneurysm, followed by parent vessel occlusion, offers an elegant solution for the treatment of A2 aneurysms that are not amenable to stand-alone clip ligation or coil occlusion. Such combined methods are invaluable in the management of complex cerebral aneurysms.

Reconstruction Options for Complex Middle Cerebral Artery Aneurysms

OBJECTIVE:

To describe techniques of reconstruction for unclippable and uncoilable middle cerebral artery aneurysms.

METHODS:

A retrospective review was performed of seven patients who underwent eight operations during a 9-year period to treat complex middle cerebral artery bifurcation aneurysms not amenable to direct clipping or endovascular coiling. All preoperative and postoperative clinical and imaging data were reviewed. Follow-up was obtained for all patients via clinic visit and/or telephone.

RESULTS:

The operative techniques used included saphenous vein graft bypass (n = 1), radial artery graft interposition (n = 2), radial artery patch (n = 1), superficial temporal artery interposition graft (n = 1), superior thyroid artery interposition graft (n = 1), direct reimplantation of branch (n = 1), and reconstruction of trifurcation (n = 1). There was no mortality. Six patients had excellent outcomes with Glasgow Outcome Scale scores of 5, and one patient had a good outcome with a Glasgow Outcome Scale score of 4.

CONCLUSION:

Techniques for middle cerebral artery reconstruction may remain important and useful in the age of endovascular aneurysm treatment.

Microsurgical anatomy of cerebral revascularization. Part I: Anterior circulation

Object. Revascularization is an important component of treatment for complex aneurysms that require parent vessel occlusion, skull base tumors that involve major vessels, and certain ischemic diseases. In this study, the authors examined the microsurgical anatomy of cerebral revascularization in the anterior circulation by demonstrating various procedures for bypass surgery.

Methods. Twenty-five adult cadaveric specimens were studied, using 3 to 40 magnification, after the arteries and veins had been perfused with colored silicone. The microsurgical anatomy of cerebral revascularization in the anterior circulation was examined with the focus on the donor, recipient, and graft vessels. The techniques discussed in this paper include the superficial temporal artery (STA)—middle cerebral artery (MCA), middle meningeal artery (MMA)—MCA, and side-to-side anastomoses; short arterial and venous interposition grafting; and external carotid artery/internal carotid artery (ICA)—M2 and ICA—ICA bypasses. Bypass procedures for cerebral revascularization are divided into two categories depending on their flow volume: low-flow and high-flow bypasses. A low-flow bypass, such as the STA—MCA anastomosis, is used to cover a relatively small area, whereas a high-flow bypass, such as the ICA—ICA anastomosis, is used for larger areas. Cerebral revascularization techniques are also divided into two types depending on the graft materials: pedicled arterial grafts, such as STA and occipital artery grafts, and free venous or arterial grafts, which are usually saphenous vein and radial artery grafts. Pedicled arterial grafts are mainly used for low-flow bypasses, whereas venous or arterial grafts are used for high-flow bypasses.

Conclusions. It is important to understand the methods of bypass procedures and to consider indications in which cerebral revascularization is needed.

Progressive Growth of a Giant Dolichoectatic Vertebrobasilar Artery Aneurysm after Complete Hunterian Occlusion of the Posterior Circulation: Case Report

OBJECTIVE AND IMPORTANCE:

Dolichoectatic vertebrobasilar artery aneurysms are often extremely difficult, if not impossible, to treat with microneurosurgical clip reconstruction. As such, a Hunterian strategy via vertebral or basilar artery sacrifice is often used. We have encountered a patient in whom deliberate bilateral vertebral artery sacrifice was insufficient to avoid progressive expansion of a giant dolichoectatic vertebrobasilar artery aneurysm. On the basis of a review of the literature, we are unaware of another reported case.

CLINICAL PRESENTATION:

A 60-year-old man presented with signs and symptoms of brainstem compression from a large fusiform aneurysm involving the distal dominant vertebral and proximal basilar arteries. Results of angiographic evaluation were highly characteristic of underlying dolichoectasia.

INTERVENTION:

The patient was treated initially with staged bilateral vertebral artery occlusion and adjunctive posterior circulation revascularization. After this therapy failed, he underwent a trapping procedure and aneurysm deflation.

CONCLUSION:

Unclippable aneurysms of the vertebrobasilar system are formidable lesions. They are not uniformly treatable by direct surgical reconstruction, and their growth is not consistently stabilized by the implementation of a complete Hunterian strategy. Future developments related to the use of endovascular stent technology may offer a more successful treatment approach for patients with these complex cerebrovascular lesions.

Aneurysms of the petrous internal carotid artery: anatomy, origins, and treatment

Aneurysms arising in the petrous segment of the internal carotid artery (ICA) are rare. Although the causes of petrous ICA aneurysms remain unclear, traumatic, infectious, and congenital origins have been implicated in their development. These lesions can be detected incidentally on routine neuroimaging. Patients can also present with a wide spectrum of signs and symptoms, including cranial nerve palsies, Horner syndrome, pulsatile tinnitus, epistaxis, and otorrhagia. The treatment of petrous ICA aneurysms remains challenging. Treatment options include close observation, endovascular therapies, and surgical trapping with or without revascularization. Management dilemmas exist, particularly for incidental lesions found in asymptomatic patients. The authors review the literature and discuss the anatomy of the petrous ICA as well as the pathophysiological features of aneurysms arising in this region, and they propose a management paradigm with current treatment options.

Primary end-to-end anastomosis of anterior cerebral artery dissecting aneurysm: technical case report and review of literature

OBJECTIVE AND IMPORTANCE:

Subarachnoid hemorrhage caused by an isolated dissection of the anterior cerebral artery (ACA) is an extremely rare problem. The optimal treatment for patients with this clinical scenario varies and is controversial in the literature. We report a patient with a hemorrhage from a distal ACA dissecting aneurysm at presentation 2 years after an arteriovenous malformation resection, who was treated effectively with excision of the diseased segment and direct revascularization of the ACA. We report this as the first case of delayed hemorrhagic arterial dissection after arteriovenous malformation resection treated with early revascularization. We review this rare topic and present our perspective on the method of treatment of ACA dissection.

CLINICAL PRESENTATION:

A 32-year-old woman was transferred to the University of Texas Southwestern Medical Center and admitted with subarachnoid and intraventricular hemorrhage. Angiography revealed the source of the hemorrhage to be a dissecting aneurysm of the pericallosal artery.

INTERVENTION:

The patient underwent surgery on the third day after hemorrhage for excision of the dissecting aneurysm and in situ primary anastomosis of the pericallosal artery. Exposure and anastomosis of the pericallosal artery was facilitated by partial resection of the genu of the corpus callosum.

CONCLUSION:

On the basis of our experience and review of the literature regarding this topic, an optimal treatment for a dissecting aneurysm with hemorrhage involving the pericallosal portion of the ACA at presentation is excision of the diseased segment followed by revascularization. This treatment should prevent rehemorrhage from the aneurysm and avoid iatrogenic ischemic complications to the ACA territory that would be likely with trapping of the aneurysm without revascularization.

Superficial Temporal Artery-to-Middle Cerebral Artery Bypass Grafting for Cerebral Revascularization

SUPERFICIAL TEMPORAL ARTERY-to-middle cerebral artery bypass procedures are an important tool in the armamentarium of cerebrovascular surgeons for the treatment of carotid occlusion and revascularization for complex aneurysms and brain tumors. This article enumerates the essential steps in performing superficial temporal artery-to-middle cerebral artery bypass procedures. The nuances of this technique reflect the extensive experience of the senior authors (RFS, JMZ).

Treatment of vertebral artery aneurysms with posterior inferior cerebellar artery-posterior inferior cerebellar artery anastomosis combined with parent artery occlusion

BACKGROUND

In patients with aneurysms that involve the origin of the posterior inferior cerebellar artery (PICA) and require occlusion of the vertebral artery (VA), revascularization of the PICA is commonly performed. We present six patients with dissecting VA aneurysms who underwent PICA-PICA anastomosis combined with parent artery occlusion.

METHODS

After a lower lateral suboccipital craniectomy and partial resection of the jugular tubercle, anastomoses were performed in a side-to-side fashion at the posterior medullary segment of the PICA. The VA was subsequently occluded by clipping proximal and distal to the aneurysm, and the PICA was occluded by clipping distal to the aneurysm.

RESULTS

Postoperative cerebral angiography demonstrated patency of the anastomosis and regression of the aneurysm in five of six patients. The remaining patient experienced hemorrhage from contralateral VA dissection and subsequently died. One patient experienced myopathy of the lower extremities secondary to intraoperative fixed board compression and developed permanent lower extremity muscular weakness. The remaining four cases experienced no new neurologic deficits.

CONCLUSION

PICA-PICA anastomosis is a useful procedure for reconstruction of the PICA when parent vessel occlusion or trapping is necessary to exclude a VA aneurysm involving the origin of the PICA.

Traumatic aneurysm of the supraclinoid internal carotid artery and an associated carotid—cavernous fistula: vascular reconstruction performed using intravascular implantation of stents and coils

✓ This report documents the treatment of a traumatic aneurysm of the supraclinoid internal carotid artery (ICA) that was associated with a carotid—cavernous fistula (CCF), which appeared following closed head trauma. This life-threatening lesion, which is very rare, required aggressive management achieved using intravascular stents and coils. A 19-year-old man presented with severe traumatic intracerebral and subarachnoid hematoma after he had suffered a severe closed head injury in a motor vehicle accident. Cerebral angiography performed 11 days after the injury demonstrated a traumatic aneurysm and severe narrowing of the right supraclinoid ICA, which was consistent with a dissection-induced stenosis associated with a direct CCF. Both lesions were successfully obliterated with preservation of the parent artery by using stents in conjunction with coils. Follow-up angiography obtained 7 months postoperatively revealed persistent obliteration of the aneurysm and CCF as well as patency of the parent artery. The patient remained asymptomatic during the clinical follow-up period of 14 months. Endovascular treatment involving the use of a stent combined with coils appears to be a feasible, minimally invasive option for treatment of this hard-to-treat lesion.

Recurrence of a vertebral artery dissecting pseudoaneurysm after successful stent-supported coil embolization: case report

OBJECTIVE AND IMPORTANCE

Dissecting aneurysms of the intracranial vertebral artery are increasingly recognized as a cause of subarachnoid hemorrhage. We present a case involving technical success of the stent-supported coil embolization but with recurrence of the dissecting pseudoaneurysm of the intracranial vertebral artery. The implications for the endovascular management of ruptured dissecting pseudoaneurysms of the intracranial vertebral artery are discussed.

CLINICAL PRESENTATION

A 36-year-old man with a remote history of head injury had recovered functionally to the point of independent living. He experienced the spontaneous onset of severe head and neck pain, which progressed rapidly to obtundation. A computed tomographic scan of the head revealed subarachnoid hemorrhage centered in the posterior fossa. The patient underwent cerebral angiography, which revealed dilation of the distal left vertebral artery consistent with a dissecting pseudoaneurysm.

INTERVENTION

Transfemoral access was achieved under general anesthesia, and two overlapping stents (3 mm in diameter and 14 mm long) were placed to cover the entire dissected segment. Follow-up angiography of the left vertebral artery showed the placement of the stents across the neck of the aneurysm; coil placement was satisfactory, with no residual aneurysm filling. Approximately 6 weeks after the patient's initial presentation, he developed the sudden onset of severe neck pain. A computed tomographic scan showed no subarachnoid hemorrhage, but computed tomographic angiography revealed that the previously treated left vertebral artery aneurysm had recurred. Angiography confirmed a recurrent pseudoaneurysm around the previously placed Guglielmi detachable coils. A test balloon occlusion was performed for 30 minutes. The patient's neurological examination was stable throughout the test occlusion period. Guglielmi detachable coil embolization of the left vertebral artery was then performed, sacrificing the artery at the level of the dissection. After the procedure was completed, no new neurological deficits occurred. On the second day after the procedure, the patient was discharged from the hospital. He was alert, oriented, and able to walk.

CONCLUSION

We appreciate the value of preserving a parent vessel when a dissecting pseudoaneurysm of the intracranial vertebral artery ruptures in patients with inadequate collateral blood flow, in patients with disease involving the contralateral vertebral artery, or in patients with both. However, our case represents a cautionary note that patients treated in this fashion require close clinical follow-up. We suggest that parent vessel occlusion be considered the first option for treatment in patients who will tolerate sacrifice of the parent vessel along its diseased segment. In the future, covered stent technology may resolve this dilemma for many of these patients.

Treatment and outcome in 30 patients with posterior cerebral artery aneurysms

OBJECT

The records of 30 patients with posterior cerebral artery (PCA) aneurysms treated during a 12-year period were reviewed to determine outcome and the risk of visual field deficit associated with PCA sacrifice.

METHODS

Clinical data and treatment summaries for all patients were maintained in an electronic database. The Glasgow Outcome Scale (GOS) and modified Rankin Scale (mRS) scores were determined by an independent registrar. Visual field changes were determined by review of medical records. Twenty-eight patients were treated with open surgery, one of them after an attempt at detachable coil embolization failed. Two patients underwent successful endovascular PCA sacrifice. The mean GOS and mRS scores in 18 patients with unruptured aneurysms were 4 and 2, respectively, at discharge. Subarachnoid hemorrhage (SAH) from other aneurysms and neurological deficits caused by the PCA lesion or underlying disease contributed to poor outcomes in this group. The mean GOS and mRS scores in 12 patients with ruptured aneurysms were 4 and 4, respectively, at discharge. One patient died of severe vasospasm. Neurological deficits secondary to SAH and, in one patient, treatment of a concomitant arteriovenous malformation contributed to poor outcomes in the patients with ruptured aneurysms. Seven patients with normal visual function preoperatively underwent PCA occlusion. One patient (14%) developed a new visual field deficit.

CONCLUSIONS

Optimal treatment of PCA aneurysms is performed via one of several surgical approaches or by endovascular therapy. The approach is determined, in part, by the anatomical location and size of the aneurysm and the presence of underlying disease and neurological deficits.

Endoscopically assisted harvesting of the superficial temporal artery: technical note

OBJECTIVE

We developed an endoscopic method for harvesting the superficial temporal artery (STA) through a small incision away from the artery. This method was used to harvest the frontal branch of the STA through an incision made along the parietal branch.

METHODS

A 7-cm linear incision is made along the parietal branch of the STA. After the parietal branch has been exposed, the frontal branch is accessed through the incision with the use of an optical retractor and a 4-mm endoscope. The frontal branch is harvested subcutaneously, under endoscopic observation. Both branches of the STA are anastomosed to the middle cerebral artery via a small craniotomy made through the incision. This method was used for six patients who presented with ischemic symptoms attributable to hypoperfusion in the middle cerebral artery area.

RESULTS

The frontal branch of the STA, measuring 6 to 8 cm, was harvested subcutaneously. The procedure required 30 to 60 minutes. The patency of the artery was verified with postoperative angiography. Hair loss or scalp necrosis was not noted for any patient.

CONCLUSION

Our experience demonstrates that the STA can be harvested through a small incision distant from the artery. Postoperative scalp necrosis and hair loss can be avoided. This less-invasive method expands the use of the STA in revascularization surgery beyond the limitations imposed by its anatomic course.

Cerebral revascularization

During the last 10 years, there has been a revival of interest in cerebral revascularization procedures. Not only have significant progressions in surgical techniques been published, the use of more advanced diagnostic methods has led to a widening of the indications for cerebral bypass surgery. The purpose of this review is to outline the current techniques for extracranial-to-intracranial (EC/IC) and intracranial-to-intracranial (IC/IC) bypass surgery, as well as to identify the current indications for revascularization procedures based on the available literature. The excimer laser-assisted non-occlusive anastomosis (ELANA) technique is described in more detail because we think that this technique almost completely eliminates the risk of cerebral ischemia due to the temporary vessel occlusion which is currently used in conventional anastomosis techniques.

Double-insurance bypass for internal carotid artery aneurysm surgery

OBJECTIVE

The aim of this article is to present the usefulness of a double-bypass method in the surgical treatment of complex internal carotid artery (ICA) aneurysms. For patients with clippable but complex aneurysms of the ICA having poor collateral circulation, bypass surgery is needed before temporary occlusion of the ICA. We propose a double bypass for safety.

METHODS

The superficial temporal artery was anastomosed to the distal cortical branch of the middle cerebral artery (MCA), followed by anastomosis between the radial artery and the inferior trunk of the MCA. For patients with clippable ICA aneurysms, the radial artery was temporarily anastomosed to the inferior trunk of the MCA by raising the ipsilateral forearm to the head after the radial artery was harvested. After the aneurysm had been clipped, the anastomosed radial artery was cut close to the anastomosed site and repositioned back to the original arm.

RESULTS

This double-bypass procedure was performed in two patients, and no ischemic complications related to revascularization were observed. Temporary occlusion times of the MCA for superficial temporal artery-to-MCA anastomosis and radial artery-to-MCA anastomosis were 30 and 46 minutes in one patient and 28 and 55 minutes in another.

CONCLUSION

This surgical procedure, which we called "double-insurance bypass," can reduce the risk of ischemic complications associated with revascularization of the ICA.

Selective cerebral revascularization as an adjunct in the treatment of giant anterior circulation aneurysms

Cerebral revascularization, an indispensable component of neurovascular surgery, has been performed in the treatment of cranial base tumors, complex cerebral aneurysms, and occlusive cerebrovascular disease. The goal of a revascularization procedure is to augment blood flow distally. It can therefore be used as an adjunctive measure in the treatment of complex neurosurgical disease processes that require parent artery sacrifice for definitive treatment. In the treatment of giant anterior circulation aneurysms, for instance, a cerebral revascularization procedure may be considered in patients in whom the collateral circulation is marginal and in whom lesions may be treated either using a Hunterian-based strategy or clip-assisted reconstruction requiring a prolonged period of temporary occlusion. To date, there is no entirely effective method known to produce long-term tolerance to carotid artery (CA) sacrifice and, largely for that reason, some neurovascular surgeons advocate universal revascularization. The authors of this report, however, prefer to perform revascularization only in the limited subset of patients in whom preoperative assessment has revealed risk factors for cerebral ischemia due to hypoperfusion. In this paper, the authors introduce their protocol for assessing cerebrovascular reserve capacity, indications for cerebral revascularization in the treatment of complex anterior circulation aneurysms, and discuss their rationale for choosing to practice selective, rather than universal, revascularization.

Conduits for cerebrovascular bypass and lessons learned from the cardiovascular experience

Direct cerebral revascularization is an important procedure in the treatment of certain complex aneurysms and skull base tumors when acute sacrifice of the internal carotid artery is required. It likely remains an appropriate treatment in a small subgroup of patients with cerebral ischemia refractory to maximal medical management. Similar to cardiovascular surgery, the choice of a graft conduit is critical for a successful outcome. The standard conduits are interposition vein grafts (usually the greater saphenous vein), free arterial grafts (radial artery), and pedicled arterial grafts (superficial temporal artery). The goal of this review is to summarize the conduits commonly used in cerebral revascularization with emphasis on their patency rates and flow characteristics. Comparisons are made with similar data available in the cardiovascular literature.

Interpositional carotid artery bypass strategies in the surgical management of aneurysms and tumors of the skull base

Cerebral revascularization is an important component in the surgical management of complex skull base tumors and aneurysms. Patients who harbor complex aneurysms that cannot be clipped directly and in whom parent vessel occlusion cannot be tolerated may require cerebrovascular bypass surgery. In cases in which skull base tumors encase the carotid artery (CA) and a resection is desired, a cerebrovascular bypass may be necessary in planned CA occlusion or sacrifice. In this review the authors discuss options for performing high-flow anterograde interposition CA bypass for lesions of the skull base. The authors review three important bypass techniques involving saphenous vein grafts: the cervical-to-petrous internal carotid artery (ICA), petrous-to-supraclinoid ICA, and cervical-to-supraclinoid ICA bypass. These revascularization techniques are important tools in the surgical treatment of complex aneurysms and tumors of the skull base and cavernous sinus.

Combined microsurgical and endovascular management of complex intracranial aneurysms

OBJECTIVE

The disciplines of microneurosurgery and cranial base surgery have reached maturity, and technical advances in the surgical management of aneurysms are limited. Although most aneurysms can be clipped microsurgically or coiled endovascularly, a subset of patients may require a combined approach. A consecutive series of patients with aneurysms in one surgeon's cerebrovascular practice was reviewed retrospectively to analyze strategies for integrating microsurgical and endovascular techniques in the management of complex aneurysms.

METHODS

Between 1997 and 2001, 596 aneurysms in 491 patients were treated microsurgically by the senior author (MTL) at the University of California, San Francisco, and 77 of these patients (96 aneurysms) were managed with a multimodality approach comprising a total of eight different combinations: selective revascularization and aneurysm occlusion (n = 23), endovascular and surgical trapping (n = 1), clipping of the aneurysm after attempted or incomplete coiling (n = 22), coiling after attempted or incomplete clipping (n = 5), clipping of recurrent aneurysm after coiling (n = 6), coiling of recurrent aneurysm after clipping (n = 1), clipping and coiling of multiple remote aneurysms (n = 13), and coiling after previous surgery (n = 6).

RESULTS

A total of 96 aneurysms were treated with combined therapy, of which 43% were large or giant in size and 34% had fusiform or dolichoectatic morphology. Complete angiographic obliteration was achieved in 91 aneurysms (95%). Overall, 66 patients (86%) had good outcomes (Glasgow Outcome Scale score of 4 or 5; mean follow-up, 9 mo). The treatment mortality rate was 9.1% (seven patients), and permanent treatment-associated neurological morbidity rate was 5.2% (four patients).

CONCLUSION

Evolving endovascular technologies need to be integrated into the microsurgical management of aneurysms. Multimodality approaches are best used with complex aneurysms in which conventional therapy with a single modality has failed. Revascularization remains a unique surgical contribution to the overall management of aneurysms with which current endovascular techniques cannot be used. Multimodality management should be considered an elegant addition to the therapeutic armamentarium that, through simplification and increased safety, improves the treatment of complex aneurysms beyond what is achievable by performing clipping or coiling alone.

[The role of the extra-intracranial anastomosis and interventionist endovascular therapy in the treatment of complex cerebral aneurysms]

Cerebral revascularization is an useful tool in the treatment of giant or complex cerebral aneurysms that can not be clipped directly by different causes. In turn, interventionist endovascular therapy, an emergent technique with very good results in the treatment of cerebral aneurysms during the last five years, is a new complementary tool to cerebral revascularization for the treatment of complex aneurysms. In the present manuscript we emphasize the beneficial effect of revascularization, followed in a short period of time by the endovascular technique in order to either occlude the parent vessel or to exclude the aneurysm from cerebral circulation. Advantages of this form of therapy, as well as the selection of patients and the present revascularization procedures, are commented.

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.

Cerebral revascularization performed using posterior inferior cerebellar artery-posterior inferior cerebellar artery bypass. Report of four cases and literature review

Cerebral revascularization is often required for the surgical treatment of complex intracranial aneurysms. In certain anatomical locations, vascular anatomy and redundancy make in situ bypass possible. The authors present four patients who underwent revascularization performed using the rarely reported posterior inferior cerebellar artery (PICA)-PICA in situ bypass after their aneurysms had been trapped. At Barrow Neurological Institute, between 1991 and the present, four male patients underwent PICA-PICA by-passes to treat aneurysms involving the vertebral artery, the PICA, or both. The mean age of these patients was 34 years (range 5-49 years). Follow-up studies revealed patent bypasses and no evidence of infarction. Patient outcomes were excellent or good. Multiple surgical techniques have been described for revascularization of at-risk cerebral territories. Often, the blood supply must be derived from extracranial sources through a mobilized pedicle or interposited graft. Certain anatomical locations such as the vertebrobasilar junction, the anterior circle of Willis, and the middle cerebral artery bifurcation are amenable to in situ bypass because there is vessel redundancy or proximity to the contralateral analogous vessel. The advantages of an in situ bypass include one suture line, a short bypass distance, and a close match with the caliber of the recipient graft. Although technically challenging, this technique can be successful and should be considered for appropriate candidates.

Treatment of giant intracranial aneurysms with saphenous vein extracranial-to-intracranial bypass grafting: indications, operative technique, and results in 29 patients

OBJECTIVE

The treatment of giant intracranial aneurysms is a challenge because of the limitations and difficulty of direct surgical clipping and endovascular coiling. We describe the indications, surgical technique, and complications of saphenous vein extracranial-to-intracranial bypass grafting followed by acute parent vessel occlusion in the management of these difficult lesions.

METHODS

Between January 1990 and December 1999, 29 patients with giant intracranial aneurysms underwent 30 saphenous vein bypass grafts followed by immediate parent vessel occlusion. There were 11 men and 18 women with a mean follow-up period of 62 months. Twenty-five patients harbored aneurysms involving the internal carotid artery, 2 had middle cerebral artery aneurysms, and 2 had aneurysms in the basilar artery. Serial cerebral or magnetic resonance angiograms were obtained to assess graft patency and aneurysm obliteration.

RESULTS

All 30 aneurysms were excluded from the cerebral circulation, with 28 vein grafts remaining patent. Two patients had graft occlusions: one because of poor runoff and the other because of misplacement of a cranial pin during a bypass procedure on the contralateral side. Other surgical complications included one death from a large cerebral infarction, homonymous hemianopsia from thrombosis of an anterior choroidal artery after internal carotid artery occlusion, and temporary hemiparesis from a presumed perforator thrombosis adjacent to a basilar aneurysm.

CONCLUSION

With appropriate attention to surgical technique, a saphenous vein extracranial-to-intracranial bypass followed by acute parent vessel occlusion is a safe and effective method of treating giant intracranial aneurysms. A high rate of graft patency and adequate cerebral blood flow can be achieved. Thrombosis of perforating arteries caused by altered blood flow hemodynamics after parent vessel occlusion may be a continuing source of complications.

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.

Bypass to the intracranial internal carotid artery

Extracranial to intracranial internal carotid artery bypass surgery with vein is well described for a number of diverse conditions. They provide high blood flow with good initial patency. However, long term patencies for specific graft types remains unknown. This is an analysis of consecutive interposition saphenous vein bypass cases between the common carotid artery (CCA) and the intracranial internal carotid artery (ICA) where the distal anastomosis was placed end-to-end immediately proximal to the posterior communicating artery in 55 patients undergoing 57 bypass procedures (bilateral in 2 cases). Twenty-five patients underwent grafting for planned vessel obliteration where the pathology required vessel sacrifice. Twenty-eight patients had bypass grafting for stroke risk reduction in the setting of threatening stroke and 4 patients had bypass grafts for emergency revascularisation in the setting of stroke in evolution. Patients were assessed preoperatively and at follow-up with modified Rankin scores. Procedural related complications included a 7% mortality and 7% functional decline. Early graft occlusion occurred in 5% of grafts leading to death in each case. A further patient died of rupture at the distal anastomosis site. In surviving patients, patency was present in 100% at last follow-up (mean 5 years and maximum 11 years) with no patient sustaining new hemispheric ischemic events. One patient developed a delayed asymptomatic stenosis within the vein graft requiring stenting. Because of the high initial management risks this technique of common carotid to intracranial internal carotid artery saphenous vein bypass surgery should be reserved for patients at considerable risk by alternate management. However, once the acute postoperative period is past the bypass appears to be robust and capable of supplying the entire distribution of a normal internal carotid artery.

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.

Giant aneurysm treated by bilateral cervical carotid artery to proximal middle cerebral artery bypass and balloon embolisation: a case report

The authors describe a case of a 59 year-old Chinese lady with a history of spontaneous left caroticocavernous fistula in 1988 treated by left internal carotid artery clipping and muscle embolisation. She subsequently presented with a subarachnoid haemorrhage in November 1997 secondary to rupture of an unclippable giant right internal carotid artery aneurysm. This was treated satisfactorily with bilateral cervical carotid artery to proximal middle cerebral artery bypass followed by balloon occlusion. Postoperatively, the patient has no neurological deficit and CT angiogram shows good patency of both grafts 6 months after surgery.

Cerebral revascularization using radial artery grafts for the treatment of complex intracranial aneurysms: techniques and outcomes for 17 patients

OBJECTIVE

The goal of this report is to illustrate the use of radial artery grafts as bypass conduits in the management of complex intracranial aneurysms and to describe a new "pressure distension technique" to eliminate postoperative vasospasm, which was a common problem early in our experience.

METHODS

This study included a series of 17 patients who were surgically treated between 1994 and January 2001 for complex intracranial aneurysms. Five patients were surgically treated without the pressure distension technique; for 12 patients, the technique was used to reduce postoperative vasospasm. Fourteen of the patients had anterior circulation aneurysms, and three had posterior circulation aneurysms. Five of the patients had undergone previous attempts at direct clipping or excision and reconstruction of the aneurysm in question, and embolization had been performed for one patient with a carotid-cavernous fistula. Thirteen patients underwent permanent revascularization combined with proximal occlusion, trapping, or clipping, and four patients underwent temporary revascularization for cerebral protection during anticipated prolonged occlusion of the parent vessel during aneurysm dissection. Surgical techniques are described, with particular reference to vessel collection and bypass techniques.

RESULTS

The outcomes for this group of patients, considering the complexity of the aneurysms and their "inoperability," with respect to direct clipping, were satisfactory. The aneurysms were completely obliterated for all patients, and the grafts were patent for all except one patient on postoperative angiograms. There were two deaths, one attributable to systemic sepsis and the other attributable to cardiac arrest during a transbronchial biopsy. The postoperative Glasgow Outcome Scale scores were either better or the same for all other patients, compared with their preoperative scores. Three of the five patients treated before the institution of the pressure distension technique experienced vasospasm of the graft, with two of those patients requiring angioplasty. For one of those patients, angioplasty led to rupture of the graft. Vasospasm was not observed for any of the 12 patients for whom the pressure distension technique was used. We observed no morbidity related to radial artery collection.

CONCLUSION

Revascularization techniques are occasionally necessary for the surgical treatment of complicated intracranial aneurysms. The merits of the use of the radial artery as a bypass conduit are discussed. Radial artery grafts should be considered as alternatives to saphenous vein and superficial temporal artery grafts. The problem of vasospasm of the artery has been solved with the pressure distention technique.

The tandem bypass: subclavian artery-to-middle cerebral artery bypass with dacron and saphenous vein grafts. Technical case report

BACKGROUND

Fusiform or dolichoectatic intracranial aneurysms often cannot be managed with conventional surgical or endovascular techniques, and instead require trapping and revascularization techniques. On rare occasions in elderly patients, extracranial sites used for anastomosing the bypass have been previously repaired with synthetic vascular prostheses. This circumstance in an elderly subarachnoid hemorrhage patient led to a novel bypass procedure, the tandem bypass: a long extracranial-to-intracranial bypass with two grafts of different materials assembled in series.

CASE DESCRIPTION

A 71-year-old man with carotid artery atherosclerotic disease and a previous vascular reconstruction (subclavian artery-to-internal carotid artery Dacron interposition graft) presented with a subarachnoid hemorrhage from a dolichoectatic supraclinoid ICA aneurysm. The aneurysm was treated with trapping and distal revascularization. The final construct was a subclavian artery-to-middle cerebral artery bypass, with the graft being the previous Dacron prosthesis and a long saphenous vein. The vein graft was anastomosed end-to-side to the Dacron graft proximally, and end-to side to the middle cerebral artery distally. Subsequently, inflow to the aneurysm was occluded with clips on the Dacron graft beyond the proximal anastomosis of the vein graft, and outflow from the aneurysm was occluded with clips on the supraclinoid ICA.

CONCLUSIONS

The tandem bypass, which uses prosthetic graft material and saphenous vein in succession, is a technically straightforward technique in patients who need extracranial-to-intracranial bypasses and who also have pre-existing carotid reconstructions or lack sufficient saphenous vein to complete a long bypass.

Reversal of severe SPECT asymmetry after venous extra-intracranial high flow bypass in a patient submitted to therapeutic internal carotid occlusion: case report

Therapeutic occlusion of the internal carotid artery is the main option for the treatment of the symptomatic intracavernous internal carotid artery aneurysms, but the issue of the best way of doing the balloon test occlusion (BTO) regarding prediction of future ischemic events remains debatable. Single photon emission computerized tomography (SPECT) has been offered as one of the best option of monitoring regional cerebral blood flow (rCBF) during the BTO, where severe asymmetry is predictive of delayed ischemia. We describe a case of important SPECT asymmetry during BTO clinically negative and its complete reversal with carotid occlusion after extra-intracranial bypass with high flow safenous vein bypass between the cervical carotid artery and the middle cerebral artery.

Current multimodality management of infectious intracranial aneurysms

OBJECTIVE

To implement an algorithm for and assess multimodality (medical, endovascular, and microsurgical) treatment of patients with infectious intracranial aneurysms.

METHODS

Twenty patients with 27 infectious aneurysms were treated during a 10-year period. Bacterial endocarditis was the most common cause (65%). Most aneurysms presented with rupture (75%), and the middle cerebral artery was the most common location (70%).

RESULTS

Five patients were treated endovascularly, with direct coiling for three patients and parent artery occlusion for two patients. Ten patients (15 aneurysms) were treated surgically, with 6 aneurysms being trapped/resected, 2 trapped/bypassed, 4 clipped, and 3 wrapped. Five patients were treated medically. Treatment-associated neurological morbidity was observed for two patients (10%), and two patients died (10%). Good outcomes were observed for 16 patients (80%).

CONCLUSION

Factors that guide management decisions for these patients include aneurysm rupture, hematomas with increased intracranial pressure, and the eloquence of brain tissue supplied by the parent artery. Patients with unruptured infectious aneurysms are initially treated medically, with antibiotics and serial angiography. Patients with ruptured aneurysms that are not associated with hematomas and that do not involve eloquent vascular territory are treated endovascularly. Patients with ruptured aneurysms are treated surgically when there is a hematoma or the risk of ischemic complications in eloquent territory. Therefore, endovascular therapy is the first option for patients in stable condition with ruptured aneurysms; surgical therapy is the first option for patients in unstable condition with ruptured aneurysms and the second option for patients in stable condition who experience failure of endovascular therapy. Medically treated patients with enlarging or dynamic unruptured aneurysms also require direct surgical or endovascular intervention. Favorable patient outcomes can be achieved with this multimodality management.

Giant petrous carotid aneurysm treated by submandibular carotid—saphenous vein bypass

✓ Petrous and cavernous sinus carotid artery (CA) aneurysms that are not amenable to clip ligation or endovascular therapy may be successfully treated by a saphenous vein bypass, thereby preserving the patency of the CA. The authors report the unique case of a 47-year-old man with a giant fusiform aneurysm of the petrous CA, who presented with a rapid onset of a lateral rectus palsy and diplopia. The lesion was treated by trapping the aneurysm and performing a saphenous vein bypass from the cervical to the intracranial CA. The saphenous vein graft was routed beneath the condyle of the mandible to reduce the overall length of the graft, thereby increasing the likelihood of long-term patency and offering protection to the graft by the mandible, temporal muscle zygomatic process, and masseter and temporal muscles. The presentation and technical aspects of the bypass graft in this unique case are discussed.