Erol Veznedaroglu

Endovascular coil embolization of ruptured and unruptured posterior circulation aneurysms: Review of a 10-year experience - Commentary

OBJECTIVETreatment of posterior circulation aneurysms poses a great technical challenge for the practicing neurosurgeon. The advent of endovascular techniques has made such treatment more feasible. We report our experience with the endovascular management of ruptured and unruptured posterior circulation aneurysms during the past 10 years. METHODSA retrospective analysis was performed on all patients with posterior circulation aneurysms undergoing endovascular treatment at Jefferson Hospital for Neuroscience between July 1995 and December 2005. This yielded 275 patients (67 men and 208 women). The degree of aneurysm occlusion was determined by the operating endovascular neurosurgeon at the time of the procedure. Successful embolization was defined as greater than 95% occlusion of the dome without any coil prolapsing into the parent vessel. Clinical outcome was evaluated using the modified Glasgow Outcome Scale. Clinical follow-up data was obtained for 262 patients (95.3%); the follow-up period ranged from 1 to 94 months (mean, 31.8 mo for procedures performed before 2004 and 13.3 mo for procedures performed during 2004 and 2005). Angiographic follow-up data was obtained for 224 patients (84.8%) for periods ranging from 6 to 94 months (mean, 31.3 mo for procedures performed before 2004 and 13.7 mo for procedures performed during 2004 and 2005). RESULTSBased on the Hunt and Hess grading scale, the patient population included 106 patients (38.5%) with unruptured aneurysms, 43 patients (15.6%) with Grade I aneurysms, 16 patients (5.8%) with Grade II aneurysms, 56 patients (20.5%) with Grade III aneurysms, and 54 patients (19.6%) with Grade IV aneurysms. The locations of the posterior circulation aneurysms included 189 (68.7%) in the basilar apex or posterior cerebral artery, 23 (8.4%) in the basilar trunk/anterior inferior cerebellar artery, 22 (8%) in the superior cerebellar artery, and 41 (14.9%) in the vertebral artery or posterior inferior cerebellar artery. Of the 275 patients, 208 (76%) were women and 67 (24%) were men. The mean age at the time of treatment was 53.9 years (range, 7–90 yr). Of all patients treated, 237 patients (87.8%) had successful embolization (>95% occlusion of the dome). On angiographic follow-up, 55 patients (24.5%) developed recanalization of at least 5%. Retreatment was required in 11 patients (4.9%; 0.01%/patient yr) and rehemorrhage occurred in three patients (1.1%; 0.003%/patient yr). Clinical follow-up was graded using the modified Glasgow Outcome Scale (mGOS) and revealed 229 patients (87.4%) in the mGOS I category, 12 patients (4.6%) in the mGOS II category, eight patients (3%) in the mGOS III category, two patients (0.8%) in the mGOS IV category, and 11 patients (4.2%) were deceased (mGOS V). Clinically significant vasospasm requiring angioplasty occurred in 11 patients (6.5%) with subarachnoid hemorrhage, and 120 patients (71%) with subarachnoid hemorrhage required ventricular shunts. Complications causing clinical morbidity occurred in 14 patients (5.1%) and ranged from postoperative ischemia to recurrent subarachnoid hemorrhage. Of all clinical factors evaluated, Hunt and Hess grade was the strongest predictor of good clinical outcome (P < 0.0001). CONCLUSIONEndovascular coil embolization of posterior circulation aneurysms is an effective treatment in the short term but is associated with recurrence, which requires close surveillance, possible retreatment, and can, albeit very rarely, lead to rehemorrhage. Future technological advancements such as the development of biologically active coils will be essential in the permanent obliteration of aneurysms.

Endovascular management of intracranial aneurysms: current experience and future advances.

OBJECTIVE:The past 15 years have seen a revolution in the treatment of intracranial aneurysms. Endovascular technology has evolved rapidly since the Food and Drug Administration approval of Guglielmi detachable coils in 1995, which now allows successful treatment of most aneurysms. The authors provide a review of their 11-year experience at Jefferson Hospital for Neuroscience with endovascular embolization of intracranial aneurysms and discuss clinical trial outcomes and future directions of this treatment method. METHODS:The authors reviewed the clinical and angiographic outcomes for 1307 patients undergoing endovascular treatment of intracranial aneurysms. Their analysis focuses on posterior circulation and middle cerebral artery aneurysms, as well as cases of stent-assisted coil embolization. They review their procedural protocol and patient selection criteria for endovascular management. RESULTS:Several large clinical trials have demonstrated the safety and efficacy of endovascular treatment of intracranial aneurysms. The International Subarachnoid Aneurysm Trial provides Level I evidence demonstrating a significant reduction in disability or death with endovascular treatment compared with surgical clipping. The most common procedural complications include intraprocedural rupture and thromboembolic events; avoidance strategies are also discussed. Vasospasm after subarachnoid hemorrhage causes neurological morbidity and mortality and can be successfully managed by early recognition and interventional treatment with angioplasty, pharmacologic agents, or both. CONCLUSION:Long-term studies evaluating experience with aneurysm coil embolization during the past decade indicate that this is a safe and durable treatment method. The introduction of stent-assist techniques has improved the management of wide-neck aneurysms. Future technology developments will likely improve the durability of endovascular treatment further by delivering bioactive agents that promote aneurysm thrombosis beyond the coil mass alone. It is clear that endovascular therapy of both ruptured and unruptured aneurysms is becoming a mainstay of practice in this patient population. Although not replacing open surgery, the continued improvements have allowed aneurysms that previously were amenable only to open clip ligation to be treated safely with durable long-term outcomes.

Defining the risk of retreatment for aneurysm recurrence or residual after initial treatment by endovascular coiling: a multicenter study.

OBJECTIVEEndovascular treatment of intracranial aneurysms is less invasive than surgical repair but poses a higher risk for aneurysm recurrence, which may necessitate retreatment, thus adding to the long-term risk. Cerebrovascular neurosurgeons from 8 institutions in the United States and Puerto Rico collaborated to assess the risk of retreatment for residual or recurrent aneurysms after the initial endovascular coiling. METHODSData were prospectively recorded for 311 patients with coiled intracranial aneurysms who underwent 352 retreatment procedures after angiographic or clinical recurrence (hemorrhage after initial coiling). Results analyzed included procedural complications and procedure-related morbidity. Morbidity was classified as major (modified Rankin scale score > 3) or minor, and temporary (<30 days) or permanent (>30 days). RESULTSRetreatment mortality was 0.85% per procedure and 0.96% per patient. Treatment-related rates were 0.32% per patient (0.28% per procedure) for permanent or temporary major disability; 1.29% for permanent minor disability (1.14% per procedure); and 1.61% for temporary minor disability (1.42% per procedure). Total risk for death or permanent major disability was 1.28% per patient and 1.13% per procedure. CONCLUSIONRetreatment poses a low risk for patients with recurrences of intracranial aneurysms after initial coiling; this risk is smaller than that posed by the initial endovascular therapy. The risk of disability associated with retreatment for aneurysm recurrence after coiling must be considered prospectively in the choice of treatment but with the recognition that its effects are low in the overall management risk.

Feasibility and limitations of endovascular coil embolization of anterior communicating artery aneurysms: morphological considerations.

OBJECTIVE The purpose of this study is to analyze anterior communicating artery (AComA) aneurysm morphology and its relationship to the limitations and feasibility of endovascular coil embolization. METHODS One hundred twenty-three patients were treated with endovascular coil embolization for AComA aneurysms. Aneurysm morphology was classified into six categories according to the projection of the aneurysm (anterior, posterior/superior, or inferior) and neck size (< 4 mm or >or= 4 mm). The following categories were used: Class A1, anterior projection and neck of aneurysm less than 4 mm; Class A2, anterior projection and neck of aneurysm 4 mm or more; Class B1, posterior (superior) projection and neck of aneurysm less than 4 mm; Class B2, posterior (superior) projection and neck of aneurysm 4 mm or more; Class C1, inferior projection and neck of aneurysm less than 4 mm; and Class C2, inferior projection and neck of aneurysm 4 mm or more. Endovascular procedures were categorized as either successful or unsuccessful according to specific criteria. In addition, patients were followed for recanalization. Clinical follow-up data was obtained at discharge and after 6 months and was classified according to the Glasgow Outcome Scale. RESULTS Complete or near complete aneurysm occlusion was observed in 108 (88%) patients, partial embolization was performed in three (2.4%) patients, and embolization was attempted in 12 (9.7%) patients. Successful embolization for AComA aneurysms was performed in 86 out of 123 (70%) patients or 77.5% (86 out of 111 patients) of those patients in whom embolization was possible. Statistical analysis demonstrated that anterior projecting aneurysms were more likely to be successfully coiled than either inferior or posterior/superior directed AComA aneurysms. In addition, inferiorly projecting AComA aneurysms and wide-neck aneurysms had a significantly higher rate of recanalization. CONCLUSION Endovascular coil embolization of AComA aneurysms shows good outcome in our study. Despite advanced modern techniques, there are limitations in the endovascular approach to AComA aneurysms. Consideration of aneurysm morphology may be used to guide approaches in the treatment of AComA aneurysms.

Endovascular treatment of spinal cord arteriovenous malformations.

SPINAL CORD ARTERIOVENOUS malformations are rare lesions that represent one-tenth of the brain arteriovenous malformations. Depending on their location and relationship to the dura, these lesions are divided into four categories. Their clinical manifestations may vary from mild symptoms to severe motor deficits. Spinal angiography remains the “gold standard” for diagnosing spinal cord vascular lesions. Although the type of shunting remains difficult to determine by the magnetic resonance imaging, it is well analyzed by spinal angiography. The cure of the shunting is not by itself a therapeutic goal, but the objective is the creation of a new hemodynamic equilibrium between the lesion and the spinal cord to decrease the risk of hemorrhage and prevent the progression of the spinal cord ischemia. The endovascular tools seem to be a reasonable therapeutic option for the treatment of the majority of the spinal cord arteriovenous malformations.

INITIAL EXPERIENCE WITH BIOACTIVE CERECYTE DETACHABLE COILS: IMPACT ON REDUCING RECURRENCE RATES

OBJECTIVEDespite proven safety of endovascular coil embolization of intracranial aneurysms, the potential need for retreatment remains criticized. The goal of this prospective study was to assess the safety, durability, and effect on recanalization rates of the Cerecyte (Micrus Corp., Sunnyvale, CA) bioactive coil. METHODSTwo hundred twelve ruptured and unruptured aneurysms in 176 patients were prospectively enrolled in a database registry during a 12-month period. Adverse clinical outcomes directly attributed to the use of the Cerecyte coil were documented. Angiographic outcomes were determined immediately after coil embolization and during follow-up studies. All patients who received stent assistance or a non-Cerecyte coil were excluded. Two independent endovascular surgeons reviewed follow-up films. Any discrepancy was deemed a recurrence. RESULTSAfter exclusion criteria, 81 patients with 89 aneurysms were available for a minimum of 6 months of follow-up. Of those 89 aneurysms, 65% were ruptured aneurysms and were treated in the acute setting. The mean size of the aneurysm was 7 mm. The mean angiographic follow-up period was 11.2 months. Recurrences requiring retreatment as a result of dome filling were identified in six aneurysms (6.7%). Four aneurysms (4%) developed compaction of more than 20%, which was defined as interstitial filling of the fundus. There was one thromboembolic event leading to permanent neurological deficit. No cases of chemical meningitis or delayed hydrocephalus occurred. CONCLUSIONThe Cerecyte bioactive coil seems to be safe and effective for use in both ruptured and unruptured aneurysms. The bioactive polymer within the coils allows similar handling characteristics of a bare platinum coil. Studies to assess long-term outcomes with direct comparison to platinum coils and alternative bioactive coils are warranted.

Management of distal anterior cerebral artery aneurysms: a single institution retrospective analysis (1997-2005).

OBJECTIVEOur goal was to assess the clinical and angiographic outcomes among patients undergoing treatment for distal anterior cerebral artery aneurysms at the Jefferson Hospital for Neuroscience (1997–2005). METHODSForty-one patients (1.5% of all aneurysms treated) with distal anterior cerebral artery aneurysms had undergone treatment. The clinical and angiographic outcomes of these patients were studied retrospectively using chart reviews, operative reports, and angiographic reports. The mean clinical and angiographic follow-up periods were 16 months (range, 3–74 mo) and 16.5 months (range, 6–81 mo), respectively. RESULTSTwenty-eight (68%) patients had undergone endovascular embolization (22 women, six men; mean age, 58.2 yr), whereas 13 (32%) had undergone microsurgery for clip ligation (six men, seven women; mean age, 47.4 yr). Within the coiled group, 50% of the patients belonged in the Hunt and Hess (HH) III and IV groups, whereas 46.2% of the patients in the clipped group were elective patients (HH Grade 0). The mean aneurysmal sizes among the clipped and coiled groups were 4.9 and 5.5 mm, respectively. Among the clipped patient population, 100% of the patients had successful clip ligation as evidenced by intraoperative cerebral angiography, there was a 0% recurrence rate among the two patients who have had long-term follow-up, 0% recurrent subarachnoid hemorrhage, and 92% patients achieved a modified Glasgow Outcome Scale score of I to II. Among the coiled patient population, there was an 89% rate of successful embolization, 18% recurrence rate, 0% recurrent subarachnoid hemorrhage, and 64% achieved a modified Glasgow Outcome Scale score of I to II. None of the patients had clinically symptomatic vasospasm. A strong correlation existed between having a ventriculostomy and requiring a shunt in patients with HH Grade IV compared with patients in HH Grades I through III. CONCLUSIONIn our analysis, clinical outcomes were better in the clipped group; however, the differences are not statistically significant (P = 0.3675) and are explained by the selection bias. Statistically significant predictors of outcomes were age (<60 yr), size of the aneurysm (>5 mm), absence of ventriculostomy, and presenting HH grade.

Does angiographic surveillance pose a risk in the management of coiled intracranial aneurysms? A multicenter study of 2243 patients.

OBJECTIVEEndovascular treatment of intracranial aneurysms is a less invasive alternative than surgical repair. However, the higher risk of recurrence after coiling necessitates regular angiographic surveillance, which has associated risks. To date, the risk of surveillance angiography has not been quantified in patients with intracranial aneurysms treated by endovascular embolization. METHODSAngiograms performed for the surveillance of coiled intracranial aneurysms in patients treated at 8 institutions were recorded prospectively. Of 3086 patients eligible for surveillance angiography according to each institutions protocol during the study period, 2243 patients (72.7%) underwent this procedure. Data were reviewed retrospectively, including the results of each angiogram, angiographic complications, and morbidity resulting from the procedure. Morbidity was classified as major (modified Rankin Scale score ≥3) or minor (modified Rankin Scale score <3) and as temporary (<30 days) or permanent (≥30 days). RESULTSOf 2814 diagnostic angiograms performed, 12 resulted in complications, including 1 (0.04%) permanent major morbidity, 2 (0.07%) temporary major morbidities, and 9 (0.32%) temporary minor morbidities; 6 of these were access site complications). No mortality or permanent minor morbidity was noted. CONCLUSIONIn this study, routine angiographic surveillance after endovascular treatment of aneurysms has a very low complication rate (0.43%). Incorporating these initial findings with the rate and risk of recurrent treatment or the risk of hemorrhage after coiling will provide a more accurate estimate of the global long-term risk of aneurysm coiling.

Endovascular management of acute symptomatic intracranial arterial occlusion.

OBJECTIVE:Acute ischemic stroke has reached epidemic proportions in the United States, affecting approximately 700,000 people annually. With the recent technological advancements in endovascular devices, clinicians now have tools capable of recanalizing acute intracranial occlusions. The combination of pharmacological thrombolysis and mechanical clot perturbation may result in increased rates of angiographic recanalization, which may lead to improvement in patient outcomes after acute stroke. METHODS:In this article, the various intra-arterial pharmacological and mechanical therapies used by interventionists to treat acute stroke are described. Strategies for using combinations of these therapies are discussed, as are preliminary radiographic and clinical outcomes. Techniques for complex mechanical stroke interventions are discussed in detail. RESULTS:Several advances in endovascular stroke technologies are becoming increasingly available. CONCLUSION:With proper patient selection, these therapies may lead to increased recanalization rates and better patient outcomes.

Spontaneous systolic blood pressure elevation during temporary balloon occlusion increases the risk of ischemic events after carotid artery occlusion.

OBJECTIVETemporary balloon occlusion (TBO) is the principal means to evaluate cerebrovascular reserve before carotid sacrifice (CS). Despite TBO, the incidence of ischemic events after CS remains a substantive problem. We hypothesized that differential alteration of systemic hemodynamic parameters during TBO could serve as measures of potential cerebral autoregulation-induced systemic compensatory responses. These responses indicate compromised cerebrovascular reserve, thereby predicting ischemic events after CS. METHODSWe conducted a retrospective review of patients who underwent TBO and CS from 1995 to the present. Demographics, neuroimaging including angiography, and hemodynamic parameters at baseline, during TBO, and after CS were reviewed. The incidence of ischemia after CS was evaluated. Multivariable logistic regression models were used to predict the risk of ischemic events. RESULTSOf 139 patients who underwent TBO, 128 (92.1%) passed according to established criteria. Of 65 patients who underwent CS, 11 patients had unchanged or decreased systolic blood pressure (SBP), whereas 54 patients had a spontaneous elevation of SBP during TBO. Only patients with a spontaneous elevation of SBP experienced ischemic events after CS (11 patients, 16.9%). All ischemic events occurred within 4 days. Men and individuals older than age 50 were at higher risk of ischemic complications, despite demonstration of tolerance to TBO. CONCLUSIONSBP changes during TBO are manifestations of systemic response to an adequate or a compromised cerebrovascular reserve. These systemic responses are crucial to predict outcome after CS. We strongly recommend adjunctive tests in the instances of spontaneous elevation of SBP during TBO, particularly in men and the elderly.