Management Of Intracranial Arteriovenous Malformations Research Articles

Huge Intracranial arteriovenous malformations

We report the case of a 27-year-old man presented to the emergency room with a 3-years history of progressive headache and epileptic seizures. His physical examination, was without anomalies. Cranial magnetic resonance imaging (MRI) with angiography (A,B,C) showed a huge and complex Intracranial arteriovenous malformations (AVMs). AVMs are abnormalities of the intracranial vessels that compose tortuous arteries and veins, and lack an intervening capillary bed. AVMs are the most common type of intracranial vascular malformations, and the leading cause of nontraumatic intracerebral hemorrhages in young people less than 35 years old. Ideal management of intracranial arteriovenous malformations (AVMs) remains poorly defined. Decisions regarding management of AVMs are based on the expected natural history of the lesion and risk prediction for peritreatment morbidity. Microsurgical resection, stereotactic radiosurgery, and endovascular embolization alone or in combination are all viable treatment options, each with different risks.

Microsurgery for intracranial arteriovenous malformation: Long-term outcomes in 445 patients.

BackgroundThe management of intracranial arteriovenous malformations(AVMs) poses challenges to the cerebrovascular specialists.ObjectiveTo review the long-term outcomes of intracranial AVMs treated with microsurgical resections.MethodsWe performed a retrospective review of 445 patients with intracranial AVMs treated in our hospital from January 1st, 2008 to December 31st, 2014. The extracted data included demographic characteristics, clinical presentations, Spetzler-Martin (SM) grades, Supplemented Spetzler-Martin (SM-Supp) Grades, treatment modalities, long-term outcomes, and obliteration rates. Outcome was assessed with a post-operative modified Rankin Scale (mRS) score at the last follow-up visit.ResultsOf the 445 patients treated with microsurgery, 298 (67.0%) patients initially presented with hemorrhage. Based on the SM grading system, the patients were graded as follows: 83(18.6%) Grade I, 156(35.1%) Grade II, 132(29.7%) Grade III, 61(13.7%) Grade IV and 13(2.9%) Grade V. Overall, 344(77.3%) patients had a favorable outcome (mRS score of 0–2). The favorable outcome for Grade I and II were 92.8% and 85.9%, respectively, sharply reducing to 52.5% in patients with Grade IV and 15.4% in patients with Grade V AVMs. 388(87.2%) patients achieved complete obliteration of the AVMs. 63(14.2%) patients experienced recurrent hemorrhage, and the frequency of rehemorrhage was highest in Grade V patients (77.0%), dropping to 3.6% and 3.8% in patients with Grade I and II lesions, respectively. Permanent neurological deficits occurred in 66(14.8%) patients and death in 35(7.9%) patients. There was no difference of AUROC values between SM grading system and SM-supp grading system (0.726 and 0.734, respectively, p = .715).ConclusionThe Spetzler-Martin grading system is a simple and effective method to estimate the risk of surgery and to evaluate the prognosis. Microsurgical resection for AVMs depends on the SM grades, and the morbidity-mortality rate increases with an increasing SM grade.

Management of Intracranial Arteriovenous Malformations (AVMs) at a Tertiary Center

Management of Intracranial Arteriovenous Malformations (AVMs) at a Tertiary Center

Diagnosis and evaluation of intracranial arteriovenous malformations.

Background:Ideal management of intracranial arteriovenous malformations (AVMs) remains poorly defined. Decisions regarding management of AVMs are based on the expected natural history of the lesion and risk prediction for peritreatment morbidity. Microsurgical resection, stereotactic radiosurgery, and endovascular embolization alone or in combination are all viable treatment options, each with different risks. The authors attempt to clarify the existing literature's understanding of the natural history of intracranial AVMs, and risk-assessment grading scales for each of the three treatment modalities.Methods:The authors conducted a literature review of the existing AVM natural history studies and studies that clarify the utility of existing grading scales available for the assessment of peritreatment risk for all three treatment modalities.Results:The authors systematically outline the diagnosis and evaluation of patients with intracranial AVMs and clarify estimation of the expected natural history and predicted risk of treatment for intracranial AVMs.Conclusion:AVMs are a heterogenous pathology with three different options for treatment. Accurate assessment of risk of observation and risk of treatment is essential for achieving the best outcome for each patient.

Stereotactic radiosurgery for intracranial arteriovenous malformations: A review.

Stereotactic radiosurgery (SRS) has proven to be an effective strategy in the management of intracranial arteriovenous malformations (AVMs) in children and adults over the past three decades. Its application has resulted in lowering the morbidity and mortality associated with treatment of deep-seated AVMs. SRS has been used as a primary modality of therapy as well as in conjunction with embolization and microsurgery in the management of AVMs. The obliteration rate after SRS has been reported to range from 35% to 92%. Smaller AVMs receiving higher marginal doses have obliteration rates of 70% and more. The median follow-up reported in most series is approximately 36-40 months. The median time to obliteration has been reported to be approximately 24-36 months in most series. Radiation-induced neurological complications have been reported in less than 10% of patients, with a 1.5%-6% risk of developing a new permanent neurological deficit. The bleeding rate during the latency to obliteration has been reported to be approximately 5%. This review describes the experience reported in literature with respect to the indications, dosage, factors affecting obliteration rate of AVMs, and complications after SRS.

Linear Accelerator Stereotactic Radiosurgery in the Management of Intracranial Arteriovenous Malformations: Long-Term Outcome

Background: Arteriovenous malformation (AVM) is one of the cerebrovascular diseases that bear a high risk of hemorrhage. The treatment modalities include microsurgical resection, endovascular embolization, stereotactic radiosurgery, or combinations that vary widely. Several large series have been reported, while data from Asian populations were few. The aim of this study was to examine the efficacy of linear accelerator stereotactic radiosurgery (LINAC SRS) for the treatment of intracranial AVMs, to evaluate the hemorrhage rate and to analyze associated factors. Methods: One hundred and sixteen patients with AVM were treated with LINAC SRS in a single institute between September 1994 and May 2005 and were retrospectively evaluated. The demographics of patients, clinical characteristics of AVM, the treatment modalities, and the parameters of the LINAC SRS were analyzed. Delayed toxicity and hemorrhage rate after treatment were also evaluated. The AVM obliteration and bleed rates were calculated using the Kaplan-Meier method and Cox regression analyses. Results: The efficacy rate with total obliteration after treatment was 81.9% (95 of 116 patients). The median interval to achieve total obliteration was 49 months. Microsurgical resection combined with SRS for residual AVMs achieved better obliteration rates compared to SRS alone (statistically significant, p = 0.001), while no significant difference was found between the embolization group and the group with no prior treatment (p = 0.895). The Spetzler-Martin grade of AVM is a relative factor of obliteration, higher grades resulting in a worse outcome (p = 0.009). Obliteration was significantly influenced by AVM volume in univariate analysis (p = 0.034), and volume <5 cm³ contributed to improved obliteration (p = 0.01). There was no statistically significant difference in the hemorrhagic rate and the complication rate between ruptured and unruptured AVMs, while the unruptured group had a higher obliteration rate (p = 0.024). The annual hemorrhage rate after LINAC SRS treatment was 1.9%. The bleeding rate was 3.3% in the first year after radiosurgery, 2.1% in the second year, 1.9% between the second and fifth year, and 1.5% between the fifth and tenth year. Patients with hemorrhagic events before radiosurgery appeared to have a higher rebleeding risk during the latency period. Twenty-three patients (19.8%) had late adverse effects with regard to posttreatment radiological follow-up, but only 1 (0.8%) had newly developed neurological deficits. Conclusion: LINAC SRS achieved a high obliteration rate and reduced the risk of hemorrhage effectively in ruptured and unruptured intracranial AVMs. Prior microsurgical resection provided better outcome, while embolization showed no benefit. Adverse effects after treatment are acceptable and require long-term follow-up.

Combined management of intracranial arteriovenous malformations with embolization and Gamma Knife radiosurgery: comparative evaluation of the long-term results

Background Volume reduction of large AVMs attained with endovascular embolization can be potentially helpful for their subsequent radiosurgical management. The objective of the present retrospective analysis was comparative evaluation of the long-term outcome after GKR for intracranial AVM performed with and without initial embolization of the nidus. Methods The long-term outcome in 15 patients with intracranial AVM treated with initial embolization and subsequent GKR was evaluated and compared with the series of 237 patients treated during the same period solely with GKR. All patients were followed at least 2 years after radiosurgery. Results Mean reductions of the nidus volume and score of the radiosurgery-based grading system for AVMs after embolization constituted 6.9 ± 2.4 mL and 0.7 ± 0.2, respectively ( P < .001). Complete obliteration of the nidus after GKR was marked in 10 cases (67%). It was attained in 9 (90%) of 10 AVMs with postembolization nidus volume less than 12 mL, and in 1 (20%) of 5 with postembolization nidus volume more than 12 mL ( P < .05). Delayed cyst formation was met once (7%). Obliteration and long-term morbidity rates did not differ significantly in patients treated with and without preradiosurgical nidus embolization, whereas nidus volume was seemingly larger in the former cohort. Conclusions Combined management with embolization and GKR may be effective for selected cases of large intracranial AVM. Radiosurgery preceded by partial nidus embolization does not associate with increased rate of long-term complications.

INTRAOPERATIVE ANGIOGRAPHY IN THE MANAGEMENT OF NEUROVASCULAR DISORDERS *

The advantages of high‐quality intraoperative angiography in cerebrovascular surgery are readily apparent. Intraoperative assessment of the vascular anatomy before the wound is closed allows for recognition and correction of technical defects and reduced the need for another operation. Apart from verifying a perfect surgical result after clipping of cerebral aneurysms or excision of arteriovenous malformation (AVM), this technique can assist in the intraoperative localization of small vascular malformations; document the patency of bypass graft; and demonstrate inadvertent occlusion of normal arteries.Lussenhop and Spence7 were among the pioneers to present their experiences with intraoperative angiographic studies, primarily in the management of intracranial arteriovenous malformations. Others extended the indications of intraoperative angiography in treating cerebral aneurysms, cerebral revascularization procedures and carotid endarterectomy surgery.In this retrospective review, we reported our early experience in using intraoperative angiography after surgical treatment of arteriovenous malformation, cerebral aneurysms and extracranial‐intracranial (ECIC) bypass procedures.From April 1999 to November 2000, 30 intraoperative digital substraction angiography were performed at Queen Mary Hospital. Of these 30 procedures (Table 1), 19 were done for cerebral aneurysm surgery; 10 were done for cerebral arteriovenous malformations; one was done for ECIC bypass surgery. Tables 1 outlines the neurovascular procedures included in this series.From April 1999 to November 2000, a total of 32 intraoperative angiography were attempted. Two out of 32 were failed due to technical problem. In one patient the machine break down during the procedure and in the other patient intimal tear of the femoral artery was noted during the angiographic studies. The procedure was abandoned to avoid further damage to the femoral artery. Thirty patients had intraoperative angiography successfully done with no complication. Four studies were performed in prone position; one study in park bench position; 25 studies in supine position.Our experience found that intraoperative angiography was safe and that it frequently revealed unclipped aneurysm, unexpected major vessels occlusion. The cost, time, effort, and complications of intraoperative angiography appear to be less than the cost, in financial terms, of reoperations and devastating postoperative complications.

Radiosurgery for childhood intracranial arteriovenous malformations.

The optimal management of intracranial arteriovenous malformations (AVMs) in children remains controversial. Children with intracranial AVMs present a special challenge in therapeutic decision-making because of the early recognition of their future life-long risks of hemorrhage if they are treated conservatively. The goals of radiosurgery are to achieve complete AVM obliteration and to preserve neurological function. We present long-term outcomes for a series of children treated using radiosurgery. The findings for 53 consecutive children who underwent at least 36 months of imaging follow-up monitoring after radiosurgery were reviewed. The median age at the time of treatment was 12 years (range, 2-17 yr). Thirty-one children (58%) presented after their first intracranial hemorrhaging episodes, two (4%) after their second hemorrhaging episodes, and one (2%) after five hemorrhaging episodes. Nineteen children (36%) presented with unruptured AVMs, and a total of 25 children (47%) exhibited neurological deficits. AVMs were graded as Spetzler-Martin Grade I (2%), Grade II (23%), Grade III (36%), Grade IV (9%), or Grade VI (30%). The median AVM volume was 1.7 ml (range, 0.11-10.2 ml). The median marginal dose was 20 Gy (range, 15-25 Gy). Results were stratified according to AVM volumes (Group 1, < or =3 ml; Group 2, >3 ml to < or =10 ml; Group 3, >10 ml). Twenty-eight patients (80%) in Group 1 and 11 (64.7%) in Group 2 achieved complete obliteration. The only patient in Group 3 did not achieve obliteration. Complications included brainstem edema (n = 1) and transient pulmonary edema (n = 1). Four patients experienced hemorrhaging episodes, 30, 40, 84, and 96 months after radiosurgery. Multivariate logistic regression analysis demonstrated that only volume was significantly correlated with obliteration rates (P = 0.0109). Radiosurgery is safe and efficacious for selected children with AVMs. The obliteration rates and the attendant low morbidity rates suggest a primary role for stereotactic radiosurgery for pediatric AVMs.

Acute Surgical Management of Intracranial Arteriovenous Malformations

Acute Surgical Management of Intracranial Arteriovenous Malformations

Acute Surgical Management of Intracranial Arteriovenous Malformations

The majority of intracranial arteriovenous malformations (AVMs) do not require acute surgical intervention. Some patients, however, require emergent surgical treatment because of a profound neurological deterioration from a mass effect. We report 10 patients who underwent emergency AVM surgery after experiencing neurological deterioration from an intracranial hemorrhage. Two patients bled spontaneously, whereas eight had an intracranial hemorrhage secondary to an embolization procedure. When the patients demonstrated neurological deterioration, they were intubated, hyperventilated, and underwent osmotic diuresis. Barbiturate anesthesia was initiated, and surgery was performed within 30 minutes in most cases. The hematomas were evacuated, and an attempt was made to excise the AVMs at the same time. Postoperatively, intracranial pressure was monitored, and barbiturate coma was maintained until the intracranial pressure returned to normal. Cerebral perfusion pressure was maintained above 55 mm Hg. The operation was confined to evacuating the hematoma in two patients with inoperable AVMs. The other eight patients underwent concomitant total AVM resection. Because of the severity of neurological deterioration, one patient who bled spontaneously underwent surgery based only on a computed tomographic scan of the brain. Nine patients made a good-to-excellent recovery. One patient with a large motor-strip AVM remained hemiplegic. We conclude that in patients presenting with profound neurological deterioration after a spontaneous intracranial hemorrhage or one associated with an embolization procedure, prompt hematoma evacuation with simultaneous AVM excision as well as perioperative intracranial pressure control with mannitol and barbiturates can yield a good-to-excellent outcome.

Intracranial arteriovenous malformations: an 11‐year experience

A consecutive series of 107 patients with an intracranial arteriovenous malformation who were considered for surgical treatment over the 11-year period between 1974 and 1985 is analysed. In 71 (66.4%) patients complete obliteration (which in some cases was combined with pre- or peroperative embolization) by surgery was attempted and was achieved in all but two patients. Five patients were treated by embolization alone and three patients by radiotherapy alone. Twenty-eight patients were managed conservatively for one of four reasons: an expectation of a good outcome without treatment (six patients); the refusal of recommended surgical treatment (five patients); poor condition at presentation (eight patients); or the risks of operative treatment were thought to be too great (nine patients). There was a 9.9% mortality in the surgically-treated series and significant morbidity in 16 (22.3%) patients. In all but two of these 16 patients, morbidity was related directly to the initial intracerebral haemorrhage. The one-year mortality in the group that did not undergo operation was significantly higher than in those patients who were treated surgically. Some general guide-lines for the management of intracranial arteriovenous malformations are proposed.