Daniel L. Barrow

Intraoperative angiography in the management of neurovascular disorders.

Intraoperative angiography is useful in verifying the goals of neurovascular operations during the procedure and before the wound is closed. We report on our technique of intraoperative angiography in 115 neurovascular operations, including obliteration of intracranial aneurysms, resection of brain and spinal arteriovenous malformations, creation of extracranial-to-intracranial bypass grafts, and carotid endarterectomy. Of these 115 procedures, intraoperative angiograms provided information that altered the operative procedure on 19 occasions. There were two complications in the 115 cases that may be related to the intraoperative angiographic procedure. Overall, however, the quality of image provided by portable digital subtraction intraoperative angiography makes this technique a safe adjunct to neurovascular surgery.

Aggressive mechanical clot disruption and low-dose intra-arterial third-generation thrombolytic agent for ischemic stroke: a prospective study.

OBJECTIVE We prospectively evaluated the safety and effectiveness of aggressive mechanical disruption of clot in conjunction with intra-arterial administration of a low-dose third-generation thrombolytic agent (reteplase) to treat ischemic stroke in patients who were considered poor candidates for intravenous alteplase therapy or who failed to improve after intravenous thrombolysis. Mechanical clot disruption was used if low-dose pharmacological thrombolysis was ineffective. This strategy was adopted to increase the recanalization rate without increasing the risk of intracerebral hemorrhage. METHODS Patients were considered poor candidates for intravenous therapy because of severity of neurological deficits, interval from symptom onset to presentation of at least 3 hours, or recent major surgery. We administered a maximum total dose of 4 U of reteplase intra-arterially in 1-U increments via superselective catheterization. After the initial doses were administered, we performed mechanical angioplasty (for proximal occlusion) or snare manipulation (for distal occlusion) at the occlusion site if recanalization had not occurred. The remaining doses of thrombolytics were subsequently administered if required for further recanalization. Angiographic responses were graded using modified Thrombolysis in Myocardial Infarction (TIMI) criteria. Clinical evaluations were performed before and 24 hours, 7 to 10 days, and 1 to 3 months after treatment. RESULTS Nineteen consecutive patients were treated (mean age, 64.3 ± 16.2 yr; 10 were men). Initial National Institutes of Health Stroke Scale scores ranged from 11 to 42. Time from onset to treatment ranged from 1 to 9 hours. Occlusion sites were in the following arteries: cervical internal carotid (n = 7), intracranial internal carotid (n = 1), middle cerebral (n = 9), and basilar (n = 2). Of the 19 patients, thrombolysis alone was used in 5 patients, angioplasty was performed in 11 patients, and snare maneuvers were used in 5 patients. Complete restoration of blood flow (modified TIMI Grade 4) was observed in 12 patients, near-complete restoration of flow (modified TIMI Grade 3) in 4 patients, minimal response (modified TIMI Grade 1) in 1 patient, and no response in 2 patients (modified TIMI Grade 0). Neurological improvement at 24 hours (decline of at least 4 points in National Institutes of Health Stroke Scale score) was observed in seven patients. Five other patients experienced further improvement in National Institutes of Health Stroke Scale score at 7 to 10 days. No vessel rupture, dissection, or symptomatic intracranial hemorrhages were observed. At the time of follow-up evaluation, 7 of 19 patients were functionally independent. CONCLUSION A high rate of recanalization and clinical improvement can be observed in patients with ischemic stroke using low-dose thrombolytic agents with adjunctive mechanical disruption of clot. Moreover, this strategy may reduce the risk of intracerebral hemorrhage observed with thrombolytics.

Recommendations for the Endovascular Treatment of Intracranial Aneurysms A Statement for Healthcare Professionals from the Committee on Cerebrovascular Imaging of the American Heart Association Council on Cardiovascular Radiology

Intracranial aneurysms are common, with a prevalence of 0.5% to 6% in adults, according to angiography and autopsy studies.1 Most intracranial aneurysms are asymptomatic and are never detected. Some are discovered incidentally in neuroimaging studies and some produce symptoms due to compression of neighboring nerves or adjacent brain tissue. Others are detected only after they have ruptured and caused subarachnoid hemorrhage, a devastating type of stroke asso-ciated with 32% to 67% case fatality and 10% to 20% long-term dependence in survivors due to brain damage.2 To prevent subarachnoid hemorrhage, physicians have developed methods to treat aneurysms. For ruptured aneurysms, early treatment within 24 to 72 hours has been recommended because the risk of subsequent rupture is high, with approximately 20% risk of rerupture in the first 2 weeks after subarachnoid hemorrhage.3 Each additional rupture substantially increases the risk of mortality and morbidity. Treatment has also been recommended for most unruptured aneurysms,4 although there is uncertainty about treatment of some small aneurysms <10 mm because their risk of rupture appears low.5,6⇓ The American Heart Association formed this special writing group to summarize the literature and create recommendations on endovascular therapy of ruptured and unruptured intracranial aneurysms. This statement is meant to extend previous statements on treatment of subarachnoid hemorrhage3 and on treatment of unruptured aneurysms.4 During the review, it became evident that any recommendations would be based primarily on expert opinion weighing evidence only from nonrandomized cohort studies and case series. In 1937, Walter Dandy reported the first successful surgical clipping of the neck of an aneurysm. Microsurgical techniques have steadily evolved since then, with development of a variety of surgical approaches and metal aneurysm clips. Repair of aneurysms in nearly all intracranial locations is possible by placing a clip made from a …

Cushing's Disease Associated with an lntrasellar Gangliocytoma Producing Corticotrophin-Releasing Factor

A 58-year-old woman had Cushings disease with elevated plasma adrenocorticotrophin and an intrasellar tumor. Light microscopy showed that the tumor was a gangliocytoma containing immunoreactive corticotrophin-releasing factor accompanied by pituitary corticotroph hyperplasia. Ultrastructural examination identified an intimate association and desmosomal attachments between interdigitating cell processes of neurons and corticotrophs. It is suggested that Cushings disease was due to the effect of corticotrophin-releasing factor on corticotrophs; this case represents a syndrome supporting the concept that, in some patients, Cushings disease may have a hypothalamic origin.

Evolution of the management of tentorial dural arteriovenous malformations

OBJECTIVETentorial dural arteriovenous malformations (DAVMs) are uncommon lesions associated with an aggressive natural history. Controversy exists regarding their optimal treatment. We present a single-institution series of tentorial DAVMs treated during a 12-year period, address the current controversies, and present the rationale for our current therapeutic strategy. METHODSTwenty-two patients with tentorial DAVMs were treated between 1988 and 2000. Treatment consisted of transarterial or transvenous embolization, surgical resection, disconnection of venous drainage, or a combination of these therapies. The clinical presentations, radiological features, treatment strategies, and results were studied. RESULTSEighteen patients (82%) presented with intracranial hemorrhage or progressive neurological deficits. Retrograde leptomeningeal venous drainage was documented in 22 cases (100%), classifying the lesions as Borden Type III. Angiographic follow-up monitoring was performed for 0 to 120 months and clinical follow-up monitoring for 1 to 120 months. Posttreatment angiography demonstrated obliteration in 22 cases (100%). Two patients experienced neurological decline after endovascular treatment and died. All of the 20 surviving patients exhibited clinical improvement; there were no episodes of rehemorrhage or new neurological deficits. Outcomes were excellent in 17 cases (77%), good in 2 cases (9%), and fair in 1 case (5%), and there were 2 deaths (9%). CONCLUSIONTentorial DAVMs are aggressive lesions that require prompt total angiographic obliteration. Disconnection of the venous drainage from the fistula may be accomplished with transarterial embolization to the venous side, transvenous embolization, or surgical disconnection of the fistula. We think that extensive nidal resections carry more risk and are unnecessary. We do not think there is a role for stereotactic radiosurgery in the treatment of these lesions.

Infectious intracranial aneurysms: comparison of groups with and without endocarditis.

A series of 12 patients with infectious intracranial aneurysms is presented, and a number of unusual features of the disorder are emphasized. A comparison of characteristics of the aneurysms and clinical course is made between patients with and without infective endocarditis. Most of the unusual characteristics of infectious aneurysms, including rare locations, causative organisms, and predisposing medical conditions, occurred in the group without endocarditis. The relationship of atypical features of infectious aneurysms to the etiology of aneurysm formation is discussed, and an approach to treatment is presented.

Combined transsphenoidal and pterional craniotomy approach to giant pituitary tumors.

OBJECTIVE We describe a combined simultaneous approach to giant pituitary tumors and present a review of 10 patients undergoing this procedure with emphasis on patient selection, surgical technique, and results. METHODS A retrospective review was performed of patients who had undergone a combined, simultaneous transsphenoidal and pterional craniotomy approach to a giant pituitary adenoma. Visual findings, endocrine presentation, and tumor type were compiled. Tumor stage and grade (Hardy classification) were based on MRI and intraoperative findings. RESULTS Gross total resection of tumor was achieved in 4 of 10 patients, near total (>90%) in 2 of 10, and subtotal (80-90%) in 4. At the time of follow-up (average, 29.7 months; range, 17-44 months), stereotactic radiosurgery had been performed in 2 patients. Of the 9 patients who presented with visual field loss, all had improvement at 1-month follow-up. At 6 months follow-up, resolution was complete in 5 patients and partial in 4. No patient had worsening of vision. Hypopituitarism persisted in all 5 patients who presented with it preoperatively. CONCLUSION The combined, simultaneous transsphenoidal and pterional approach described is indicated for a small subset of patients with giant (>3 cm) clinically nonfunctional pituitary tumors who meet the criteria of tumor configuration outlined where the surgeon cannot achieve complete resection by a single approach. We propose adding a new Hardys scheme subtype, Stage B-a, to describe giant pituitary tumors with a dumbbell configuration. Combining both craniotomy and transsphenoidal approaches may achieve the goal of tumor resection with less need for multiple sequential operations.

Symptomatic Rathke's cleft cysts located entirely in the suprasellar region: review of diagnosis, management, and pathogenesis.

Three cases of an entirely suprasellar symptomatic Rathkes cleft cyst, two of which were associated with normal sella turcicas, are reported. In all cases, the cysts caused compression of the optic chiasm, and two produced hypothalamic dysfunction. The diagnosis of these entirely suprasellar masses was enhanced by metrizamide cisternography. Two cases were treated by frontal craniotomy and one was treated transsphenoidally, with good results in all cases. The radiology, pathology, and surgical treatment of these unusual cases is presented. An embryological pathogenesis for the occurrence of an entirely suprasellar Rathkes cleft cyst is discussed.

The blood supply of the intracavernous cranial nerves: an anatomic study.

Cranial nerve deficits are the most common complications of cavernous sinus surgery. Often the deficit occurs despite anatomic preservation of the nerve, and ischemic injury is thought to be the cause. A better understanding of the blood supply of these nerves may help to prevent such complications. The authors performed a cadaveric microsurgical study of the intracavernous cranial nerves and their blood supply in 20 cavernous sinuses. The oculomotor nerve received branches from the inferolateral trunk or its equivalent in all specimens (100%). The proximal trochlear nerve received branches from the inferolateral trunk in 80% of the specimens and from the tentorial artery of the meningohypophyseal trunk in 20%. The distal half was supplied by the branches from the inferolateral trunk only. In the region of Dorellos canal, the proximal third of the abducens nerve received branches from the dorsal clival artery of the meningohypophyseal trunk. The middle and distal thirds received branches from the inferolateral trunk. The ophthalmic and proximal maxillary segments of the trigeminal nerve received branches from the inferolateral trunk. The distal maxillary segment was supplied by the artery of the foramen rotundum. In the majority of cases, the medial third of the Gasserian ganglion received branches from both the inferolateral trunk and the tentorial artery. The middle third of the ganglion received branches from either the inferolateral trunk or the middle meningeal artery. Our findings indicate the important role the intracavernous branches of the internal carotid artery play in the blood supply of the intracavernous cranial nerves, and stress the need to preserve these branches to prevent or minimize postoperative deficits.

Neurosurgical management of intracranial aneurysms previously treated with endovascular therapy.

OBJECTIVEWith the increased use of endovascular therapy, an increasing number of patients with incompletely treated intracranial aneurysms are presenting for further surgical management. This study reviews our experiences with such patients. METHODSDuring a 7-year period, 38 patients with 40 intracranial aneurysms who were initially treated with endovascular therapy underwent surgical obliteration of refractory or recurrent lesions. All patients were recorded in a prospective registry, and their clinical data and imaging studies were analyzed retrospectively. RESULTSTwenty-six anterior and 14 posterior circulation aneurysms were treated. Four aneurysms were on the cavernous internal carotid artery, 13 were on the distal internal carotid artery, 6 were on the anterior communicating artery complex, 2 were on the middle cerebral artery, 3 were on the posteroinferior cerebellar artery, 1 was at the vertebrobasilar junction, 3 were on the superior cerebellar artery, 4 were at the basilar apex, 2 were on the posterior cerebral artery, and 1 was on the distal vertebral artery. Two pseudoaneurysms—one on the petrocavernous segment of the internal carotid artery and one on the distal VA—also were treated. The median time until recurrence was 6 months. Thirty-one aneurysms were clip-ligated, and six were treated with trapping. Three extracranial-intracranial bypasses were performed. One aneurysm was treated with muslin wrapping. Two aneurysms required the use of surgical approaches that involved hypothermic circulatory arrest. Nine aneurysms required coil mass extraction and/or complex vascular reconstruction to complete lesion obliteration. All aneurysms except the single wrapped aneurysm were successfully excluded from the intracranial circulation. Two deaths occurred as a result of the operative procedures, and another patient died as a result of subarachnoid hemorrhage-induced massive myocardial infarction. Ultimately, 86.8% of patients achieved an excellent or good recovery. CONCLUSIONWith endovascular therapy assuming an increasing role in the treatment of patients with intracranial aneurysms, more lesions that are refractory to initial treatment will require surgical management. Our experience indicates that good results are attainable, although technical challenges are frequently encountered.