Preoperative embolization of cerebral arteriovenous malformations with silk sutures: analysis and clinical correlation of complications revealed on computerized tomography scanning.

OBJECT: The aim of this study was to determine the incidence and clinical significance of complications related to preoperative embolization of cerebral arteriovenous malformations (AVMs) with silk sutures as documented on postprocedure computerized tomography (CT) scans. METHODS: The CT scans were obtained within 12 to 24 hours after 221 (96%) of 230 consecutive embolizations in 70 patients. These CT scans were evaluated for the presence of ischemia, infarction, hemorrhage, or contrast agent extravasation. Adverse patient outcomes were determined after each embolization and were correlated with CT findings. New abnormalities demonstrated on CT scans were also correlated with the Spetzler-Martin AVM grade, degree of arteriovenous shunting, and location. New abnormalities, the majority of them infarcts, resulted from 29 (13%) of 221 embolization procedures. In 11 (38%) of 29 cases of new CT findings, patients were asymptomatic, including 10 with new infarcts on CT scans. New neurological deficits occurred in 20 (8.7%) of 230 total embolization procedures in 19 patients, including one death. Permanent deficits occurred in nine patients (3.9% per embolization procedure, 12.8% per patient). Of the patients with new neurological deficits, 18 (90%) of 20 embolization procedures resulted in new abnormalities on CT scans. Two patients with new transient neurological deficits had no new findings on CT scans. Spetzler-Martin grade, AVM location, degree of arteriovenous shunting, and higher numbers of procedures were not statistically associated with a higher incidence of abnormalities on CT scans or new permanent neurological deficits. CONCLUSIONS: Silk sutures are an effective and relatively safe embolic agent. After brain AVM embolization with silk sutures, new abnormalities were found on CT scans obtained in one of eight procedures. When a new CT finding occurred, the patient had roughly equal chances of having no new symptoms, having new transient neurological deficits, or having new permanent neurological deficits.

Intracranial angioplasty and thrombolysis.

With careful patient selection, timely neuroendovascular therapy can improve the clinical outcome of patients suffering from cerebrovascular ischemic disease. The current indications, techniques, recent experiences, limitations, and future directions of balloon angioplasty and local intra-arterial/intravenous thrombolysis in the treatment of intracranial vasospasm, atherosclerotic disease, thromboembolism, and dural sinus thrombosis are reviewed.

Endovascular therapy for aneurysmal vasospasm.

Endovascular treatment of cerebral vasospasm induced by subarachnoid hemorrhage has become a useful therapy. The two main treatments that have been used are balloon angioplasty and intra-arterial papaverine infusion. Both treatments have been shown to reverse subarachnoid hemorrhage-induced vascular spasm, increase cerebral blood flow and improve delayed ischemic neurologic deficits induced by vasospasm. Balloon angioplasty is superior to papaverine for treatment of proximal vessel vasospasm by virtue of a more sustained effect on the vessels. Papaverine can be useful as an adjunct to balloon angioplasty and also for the treatment of distal vessels that are not accessible for balloon angioplasty.

Embolization of meningohypophyseal and inferolateral branches of the cavernous internal carotid artery.

BACKGROUND AND PURPOSE: Despite the continued improvements in endovascular techniques this decade, few dedicated studies addressing the feasibility of such procedures or their efficacy relative to risk have been conducted. The purpose of this study was to use current endovascular techniques to assess the feasibility, effectiveness, and safety of direct selective catheterization and embolization of the small branches of the cavernous segment of the internal carotid artery. METHODS: We retrospectively reviewed the findings in 10 patients with lesions (five meningiomas and five arteriovenous malformations) primarily or partly supplied by branches of the meningohypophyseal trunk or inferolateral trunk who had undergone endovascular embolization of the feeding arteries during the period from 1991 to 1997. In each case, the artery was selectively catheterized with a microcatheter/microguidewire system and embolized with polyvinyl alcohol particles (n = 5), n-butyl cyanoacrylate tissue adhesive (n = 4), or both (n = 1). RESULTS: In all 10 patients, the feeding artery from the meningohypophyseal trunk (eight patients) or inferolateral trunk (three patients; one patient with both) was successfully catheterized and embolized. In nine patients, embolization resulted in complete obliteration of the vascular territory; in the remaining patient, blood supply was decreased by an estimated 80%. No immediate or delayed complications occurred. CONCLUSION: Advances in microcatheter and microguidewire technology allow more efficient and safer selective catheterization and embolization of branches of the cavernous segment of the internal carotid artery than in the recent past. Meticulous technique and detailed knowledge of the vascular anatomy of the cavernous sinus region are necessary to maximize lesion devascularization and to minimize the risk of stroke, cranial nerve palsies, and blindness.

Balloon angioplasty of the A1 segment of the anterior cerebral artery narrowed by vasospasm. Technical note.

The authors describe a new endovascular technique that improves catheterization and balloon angioplasty of the A1 segment of the anterior cerebral artery after it has been narrowed by vasospasm. The technical results of using this method in seven patients are presented.

Complex right hemisphere developmental venous anomaly associated with multiple facial hemangiomas. Case report.

Complex developmental venous anomalies (DVAs) represent variations of normal cerebral venous drainage and consist of dilation of the superficial and/or deep venous system. These rare anomalies can occur unilaterally or bilaterally, supratentorially or infratentorially, focally or they can affect the entire hemisphere. Some DVAs are associated with cervicofacial venous malformations or facial lymphatic malformations. Anomalies of this type are generally clinically silent, and cerebral dysfunction is usually absent. Symptoms, when they occur, are most commonly headache or mild seizure disorders. The angiographic findings are striking, with well-formed but enlarged transcerebral medullary and deep and/or superficial cortical veins. Opacification of these venous structures occurs within the same time frame as a normal angiographic venous phase. The authors report the case of a 33-year-old man in whom a large inoperable arteriovenous malformation had been previously diagnosed and who presented with seizures. Repeated magnetic resonance imaging and angiography demonstrated abnormally dilated transcerebral, superficial, and deep venous structures involving the entire right hemisphere with no identifiable nidus. Additionally, multiple bilateral benign facial hemangiomas were present in this patient. It is important to recognize this rare venous appearance as a developmental variant and not mistake it for an arteriovenous malformation or a partially thrombosed vein of Galen malformation. Because these venous anomalies are extreme variants of the normal venous system, hemorrhage rarely, if ever, occurs and the patient can be reassured that no interventional or surgical therapy is necessary or warranted.

Transcatheter arterial embolization for intractable epistaxis secondary to gunshot wounds.

PURPOSE: To evaluate the efficacy of transcatheter arterial embolization for intractable epistaxis secondary to gunshot wounds. MATERIALS AND METHODS: Seven patients with intractable epistaxis secondary to penetrating trauma (gunshot wounds) were studied with angiography and subsequently underwent embolization with particles (polyvinyl alcohol, gelatin sponge) and/or microcoils. Clinical follow-up included standard hemodynamic monitoring, serial hematocrit determinations, and clinical observation for recurrent bleeding. RESULTS: Diagnostic angiography demonstrated evidence of acute arterial injury in all patients. All patients subsequently underwent embolization to complete angiographic stasis. Two patients had persistent bleeding following embolization. One of these patients required maintenance of his nasal packing for 7 days after embolization; no blood products were required during this time. The second patient's bleeding resolved following correction of his coagulopathy. No complications occurred in any of the patients. CONCLUSIONS: Transcatheter arterial embolization for epistaxis secondary to gunshot wounds is efficacious in the acute setting when conservative management fails.

Resolution of central pain after embolization of an arteriovenous malformation. Case report.

The authors describe a patient with right-sided central pain resulting from a left parietal arteriovenous malformation (AVM). The AVM was treated with staged embolization and stereotactic radiosurgery, and its obliteration was documented on follow-up angiographic studies. Surprisingly, the patient noted complete resolution of her pain syndrome after embolization, which is an extremely rare result. Central pain and its proposed mechanisms are discussed.

Interventional endovascular therapy: SPECT cerebral blood flow imaging compared with transcranial doppler monitoring of balloon angioplasty and intraarterial papaverine for cerebral vasospasm.

The effects of interventional endovascular treatment of cerebral vasospasm with balloon angioplasty or papaverine infusion were evaluated by single-photon emission computed tomography (SPECT) and transcranial Doppler (TCD) in 44 patients whose cerebral vasospasm was refractory to medical management. SPECT revealed blood flow improvements in 42% of patients with papaverine treated vessels and 70% of patients with balloon angioplasty (P=.037). TCD correlated with SPECT in 71% of patients in the papaverine group and 73% of patients in the balloon angioplasty group. TCD showed 93% of segments improved by angioplasty, whereas 43% of segments were improved with papaverine (P<.001). Disagreements were largely represented by patients with TCD velocity improvements in which SPECT blood flow imaging was, unchanged or worsened. Balloon angioplasty seems superior to papaverine infusion for treatment of vasospasm. SPECT and TCD are complementary tests in the evaluation of vasospasm and effect of interventional therapy.

Endovascular embolization of 150 basilar tip aneurysms with Guglielmi detachable coils: results of the Food and Drug Administration multicenter clinical trial.

OBJECT: To assess the safety and efficacy of aneurysm embolization performed using Guglielmi detachable coils (GDCs), the authors reviewed the results of a cohort of 150 patients with either ruptured (83 patients) or unruptured (67 patients) basilar tip aneurysms treated with these detachable platinum coil devices in the early part of the United States multicenter GDC clinical trial that led to Food and Drug Administration approval for the device. METHODS: The most common presentation in this cohort of patients was headache (53%). All patients were entered into the trial after neurosurgical assessment excluded them as candidates for surgical clipping of their aneurysms. Greater than 90% coil packing was achieved in 75% of the patients. For those patients in whom follow-up information was available, the mean angiographic and clinical evaluation follow-up time for 61 patients with ruptured aneurysms was 13.7 months (range 0-43 months) and that for the 49 patients with unruptured aneurysms was 9.8 (range 0-40 months). Conservative mortality rates included up to 23% for the ruptured aneurysm group and up to 12% for the unruptured aneurysm group; the rebleeding rate for treated ruptured aneurysms was up to 3.3% and the bleeding rate for unruptured aneurysms up to 4.1%. Permanent deficits due to stroke in patients with ruptured or unruptured aneurysms occurred in up to 5% and 9%, respectively. Vasospasm occurred in 8% of the patients; it was associated with two deaths. Periprocedural mortality was 2.7% (four patients with ruptured aneurysms). CONCLUSIONS: Detachable platinum coil embolization is a promising treatment for ruptured basilar tip aneurysms that are not surgically clippable; in selected patients it offers lower incidences of morbidity and mortality compared with conservative medical management. The role of this procedure in unruptured basilar tip aneurysms is unclear with less supportive results. More long-term follow-up evaluation is necessary and results are expected to improve.

Risks and benefits of diagnostic angiography after aneurysm surgery: a retrospective analysis of 597 studies.

INTRODUCTION: Cerebral angiography performed after aneurysm surgery can identify causes of morbidity and mortality that may be corrected. The risks and benefits of angiography that is performed after aneurysm surgery, however, have not been clearly defined. We therefore reviewed our experience with postoperative angiography to determine its dangers and benefits. METHODS: During 10 years, 543 consecutive patients received treatment for cerebral aneurysms. A retrospective analysis of 597 diagnostic angiograms obtained after aneurysm surgery for 494 of these patients was performed. RESULTS: Catheter-induced vessel spasm and dissection, occurring most frequently in the internal carotid artery, were observed in seven (1.2%) and six (1%) studies, respectively. No angiography-associated strokes were identified. No association between age, smoking, hypertension, blood pressure, atherosclerosis, or severe vasospasm and angiographic complications was observed. Aneurysm remnants were identified in 36 (5.7%) of the 637 aneurysms that were surgically treated. Atherosclerosis (P < 0.01) or multiple clip applications (P < 0.01) were significantly associated with aneurysm remnants. Angiographic vessel occlusion was observed in 28 (5.7%) patients and resulted in stroke in 14 of these patients. Vessel occlusion was significantly associated with increasing aneurysm size (P < 0.001), atherosclerosis (P < 0.001), temporary clips (P < 0.001), multiple clips (P=0.03), multiple clip applications (P=0.001), and a new postoperative neurological deficit (P=0.002). Severe vasospasm and newly identified aneurysms were observed in 51 and 16 patients, respectively. CONCLUSION: Angiography after aneurysm surgery is safe and can be routinely performed. Angiography after aneurysm surgery should be particularly considered for patients with large aneurysms or cerebrovascular atherosclerosis and for those who develop new postoperative neurological deficits.

Balloon angioplasty for the treatment of vasospasm: results of first 50 cases.

OBJECTIVE: To report the results of the first 50 consecutive patients with vasospasm secondary to subarachnoid hemorrhage treated with balloon angioplasty after failure of medical management. METHODS: Retrospective uncontrolled study of 50 consecutive patients treated with balloon angioplasty between February 1988 and July 1992. Forty-six had objective clinical deterioration despite maximal medical therapy, whereas four were treated on the basis of rapidly accelerating transcranial Doppler velocities and decreased regional blood perfusion detected by technetium-99m-exametazime brain single photon emission computed tomography. All patients had evidence of marked vasospasm demonstrated by angiography. Thirty-two (64%) and 46 (92%) patients underwent angioplasty within 12 and 18 hours, respectively. RESULTS: Of the patients with clinical evidence of vasospasm-induced ischemia, 28 (61%) showed sustained neurological improvement within 72 hours of angioplasty. Three (6%) patients deteriorated within 72 hours after angioplasty, with two (4%) patients dying immediately after angioplasty as a result of vessel rupture and the other patient's Glasgow Coma Scale score decreasing by 2. Two additional patients in poor condition with Hunt and Hess Grade V at the time of angioplasty subsequently died during hospitalization. Two other patients died as a result of unclipped aneurysms that subsequently bled 4 and 12 days after angioplasty, respectively. The improvement demonstrated clinically, angiographically, and by transcranial Doppler after angioplasty was sustained, with only one patient requiring subsequent angioplasty of a previously dilated segment (total, 170 vessel segments dilated). Two patients developed vasospasm in previously undilated segments. CONCLUSION: Timely balloon angioplasty can reverse delayed ischemic deficit caused by vasospasm in patients for whom medical therapy has failed.

Comparison of balloon angioplasty and papaverine infusion for the treatment of vasospasm following aneurysmal subarachnoid hemorrhage.

OBJECT: The purpose of this study was to test the hypothesis that balloon angioplasty is superior to papaverine infusion for the treatment of proximal anterior circulation arterial vasospasm following subarachnoid hemorrhage (SAH). Between 1989 and 1995, 125 vasospastic distal internal carotid artery or proximal middle cerebral artery vessel segments were treated in 52 patients. METHODS: Blood flow velocities of the involved vessels were assessed by using transcranial Doppler (TCD) monitoring in relation to the day of treatment with balloon angioplasty or papaverine infusion. Balloon angioplasty and papaverine infusion cohorts were compared based on mean pre- and posttreatment velocity at 24 and 48 hours using the one-tailed, paired-samples t-test. Balloon angioplasty alone was performed in 101 vessel segments (81%) in 39 patients (75%), whereas papaverine infusion alone was used in 24 vessel segments (19%) in 13 patients (25%). Although repeated treatment after balloon angioplasty was needed in only one vessel segment, repeated treatment following papaverine infusion was required in 10 vessel segments (42%) in six patients because of recurrent vasospasm (p < 0.001). Seven vessel segments (29%) with recurrent spasm following papaverine infusion were treated with balloon angioplasty. Although vessel segments treated with papaverine demonstrated a 20% mean decrease in blood flow velocity (p < 0.009) on posttreatment Day 1, velocities were not significantly lower than pretreatment levels by posttreatment Day 2 (p = 0.133). Balloon angioplasty resulted in a 45% mean decrease in velocity to a normal level following treatment (p < 0.001), a decrease that was sustained. CONCLUSIONS: Balloon angioplasty is superior to papaverine infusion for the permanent treatment of proximal anterior circulation vasospasm following aneurysmal SAH.

Neuroradiologic diagnosis and treatment of vasospasm.

For survivors of aneurysmal subarachnoid hemorrhage, cerebral vasospasm significantly contributes to its morbidity and mortality by causing delayed ischemic neurological deficit. Noninvasive evaluation with computed tomography, transcranial doppler and single photon emission computerized tomography helps guide clinical decisions. Endovascular therapy of symptomatic vasospasm with balloon angioplasty and to a lesser extent with intraarterial papaverine infusion has emerged as an important treatment adjunct to neurosurgical medical and operative management. Early and aggressive treatment with balloon angioplasty has resulted in sustained clinical improvement in about two-thirds of patients suffering from neurological deficits attributable to vasospasm. Encouraging long-term clinical and transcranial artery damage following angioplasty. Despite balloon angioplasty's 2% to 5% peri-procedure mortality rate, it remains under used.

Embolization of cerebral arteriovenous malformations with silk: histopathologic changes and hemorrhagic complications.

PURPOSE: To evaluate the safety of silk as an embolic agent for preoperative embolization of cerebral arteriovenous malformations (AVMs) by assessing the histopathologic changes and hemorrhagic complications associated with its use. METHODS: Histopathologic specimens, medical records, and radiologic records of 73 patients with AVMs embolized with silk (alone or in combination with other agents) were reviewed retrospectively. Forty-eight histologic specimens obtained at surgery were analyzed for inflammatory responses and compared with the time interval between embolization and surgery. Postembolization angiograms were assessed for vasculitis and CT scans were reviewed for evidence of hemorrhage after embolization. RESULTS: There was no angiographic evidence of vasculitis. Histologic evidence of vasculitis was absent or mild in 92% of cases and histologic evidence of perivascular inflammation was absent or mild in 73% of cases. The frequency of histologic changes associated with vasculitis, perivascular inflammation, and vessel necrosis varied with the time interval between embolization and AVM resection. Intracranial hemorrhage, as a direct complication of silk use, occurred in one patient. Another patient had subarachnoid hemorrhage 24 hours after embolization, caused by rupture of a posteroinferior cerebellar artery aneurysm. Intraventricular high-density material appeared on routine postembolization CT scans in two other patients who had intraventricular AVM extension. This high-density material was thought to be contrast extravasation from intrinsically leaky AVM nidus vessels and not frank hemorrhage. CONCLUSION: Embolization of AVMs with silk does not result in marked inflammation or increased hemorrhagic complications as compared with other agents.

Preoperative endovascular embolization of craniospinal hemangioblastomas.

PURPOSE: To determine whether hemangioblastomas, highly vascular tumors requiring surgery that is potentially complicated by excessive bleeding, can be embolized safely by using interventional techniques that furnish a more avascular surgical field. METHODS: Nine hemangioblastomas involving either the cerebellum or the spinal cord were embolized preoperatively. In each case the feeding artery was selectively catheterized with a microcatheter and the hypervascular tumor nidus was devascularized with polyvinyl alcohol particles. RESULTS: Two patients who had undergone recent attempts as surgical resection at another institution had repeat surgery after endovascular embolization rendered the tumor nidus avascular. At surgery, the tumor was completely removed in one case and markedly debulked in the other. In all nine cases, blood loss after embolization was reported to be less than expected by experienced surgeons. In addition, manipulation and removal of the tumor was reported to be subjectively easier in these embolized tumors. The embolization procedure caused no permanent complications; however, one patient with a posterior fossa hemangioblastoma and hydrocephalus worsened clinically within 12 hours of embolization. This event was thought to be caused by obstructive hydrocephalus resulting from tumor swelling. Emergency craniotomy, ventricular decompression, and surgical resection of the tumor produced complete resolution of the signs and symptoms. CONCLUSIONS: Our results indicate that preoperative embolization of hemangioblastomas is a safe procedure that is useful in aiding surgical resection of these highly vascular tumors.