Faculty Bibliography

BACKGROUND AND PURPOSE: Hypotension and bradycardia are common in carotid artery stenting (CAS) and are particularly worrisome in the high risk patient who is typically referred for CAS. The purpose of this work was to assess the incidence and predictors of hypotension and bradycardia and the risk of their delayed occurrence after CAS. MATERIALS AND METHODS: A total of 53 men and 40 women (median age, 71 years) with symptomatic (57%) or asymptomatic (42%) carotid artery stenosis had CAS performed in our institution between December 2002 and January 2007. Patient vital sign records for the 12 hours post-CAS were analyzed. The relative decrease of blood pressure and pulse rate were used as primary end points, and the requirement of pressor or anticholinergic drugs was used as a surrogate end point. Significant predictors of hypotension and bradycardia were analyzed with a logistic regression model. Cumulative freedom from hypotension and bradycardia was calculated by using the Kaplan-Meier method. Negative predictive value (NPV) of screening for early hypotension and bradycardia was determined. RESULTS: The incidence of hypotension, bradycardia, and both was 14%, 23%, and 15%, respectively. Drug intervention was required in 45 patients (48%). Asymptomatic stenosis was an independent predictor of hypotension and bradycardia. Stenosis proximity to the bifurcation and dilation percentage were independent predictors of the drug intervention requirement. Seven patients (8%) had new onset of hypotension or bradycardia later than 6 hours post-CAS. The NPV of early hypotension and bradycardia was 97% and 93%, respectively. CONCLUSION: In this retrospective study, the risk of hypotension or bradycardia after CAS is significantly influenced by the degree of dilation performed, and the risk of their delayed occurrence may justify a minimum of 12 hours postprocedural vital sign monitoring

OBJECTIVE: To compare cost-effectiveness of different strategies for completion angiography after cerebral aneurysm clipping. METHODS: A literature search was used to determine the outcome probabilities and costs of various strategies. The pooled results were used in a Markov cost-effectiveness model to compare quality-adjusted life-years and costs of each strategy. Sensitivity (threshold) analyses and Monte Carlo simulation were used to test variation in the model. RESULTS: Routine (for all cases) intraoperative angiography proved to be slightly more cost-effective than selective (only for cases deemed 'high risk') intraoperative angiography, being both less costly and more effective. Routine postoperative angiography was the least cost-effective. However, in centers whose rates of clip-induced arterial compromise are much lower than the averages reported in the literature, selective angiography might be warranted. CONCLUSION: Routine intraoperative angiography remains the most cost-effective form of completion angiography after aneurysm clipping, at least at our present state of technology

OBJECTIVE: To evaluate the midterm results of intracranial stent-assisted coil embolization in the treatment of wide-necked cerebral aneurysms and to assess the efficacy of various strategies used in stent deployment. METHODS: A retrospective study of 42 patients with 46 wide-necked cerebral aneurysms enrolled in a prospective single-center registry of patients treated with a Neuroform stent (Boston Scientific/Target, Fremont, CA), a flexible self-expanding nitinol stent, was performed. Twenty-seven of 46 aneurysms were unruptured aneurysms, 14 were recanalized aneurysms, and five were acutely ruptured. Thirty-nine aneurysms were located in the anterior and seven in the posterior circulation. Mean aneurysm size was 9.8 mm. Stenting before coiling was performed in 13 of 45 aneurysms (29%), coiling before stenting in 27 of 45 aneurysms (60%), and stenting alone in five of 45 aneurysms (11%). The balloon remodeling technique for coiling before stenting was performed in 77% of patients. Angiographic and clinical follow up was available in 31 patients with 33 aneurysms and ranged from 3 to 24 months. RESULTS: Neuroform stenting was attempted in 46 wide-necked aneurysms (42 patients). Forty-nine stent sessions were performed, including three poststent retreatments. In 46 of 49 sessions (94%), successful deployment of 47 stents for 45 aneurysms was obtained. In 40 aneurysms treated with stent-assisted coiling, angiographic results showed 14 (35%) aneurysm occlusions, 18 (45%) neck remnants, and eight (20%) residual aneurysms. In five recanalized aneurysms treated with stenting alone, no changes were observed in four (80%) aneurysms and one (20%) neck remnant reduced in size. At angiographic follow-up in 30 aneurysms treated with stent-assisted coiling, there were 17 (57%) aneurysm occlusions, seven (23%) neck remnants, and six (20%) residual aneurysms. In three recanalized aneurysms treated with stent alone, two (67%) neck remnants remained unchanged and one (33%) neck remnant decreased in size. Procedural morbidity was observed in two of 42 patients (4.8%) and one patient died. On clinical follow-up, the modified Rankin Scale score was 0 in 27 patients (87%), 1 in three patients (10%), and 2 (3%) in one patient. No aneurysm bled during the follow-up period. CONCLUSION: These results indicate that Neuroform stent-assisted coil embolization is a safe and effective technique in the treatment of wide-necked cerebral aneurysms. Further studies are needed to evaluate the long-term durability of stent-assisted aneurysm occlusion and tolerance to the stent

This 65-year-old man presented to the authors' institution reporting neck swelling. Stage IIIA Hodgkin disease was diagnosed, and a computed tomography scan of the neck revealed a vertebrobasilar artery aneurysm. His medical history was significant for subarachnoid hemorrhage and coma 2 years earlier. Subsequent digital subtraction angiography demonstrated a giant fusiform vertebrobasilar junction aneurysm with associated basilar artery (BA) fenestration. Endovascular treatment of the giant aneurysm was performed by left vertebral artery (VA) occlusion and placement of two Jo-stent coronary stent grafts from the right VA to the BA. The postprocedure course was uneventful. Follow-up angiography performed 1 week postoperatively demonstrated complete exclusion of the aneurysm. This unique case is described and a review of the relevant literature is presented

BACKGROUND: The false-negative rate of DSA in the setting of a ruptured cerebral aneurysm is approximately 15% (Topcuoglu M, Ogilvy C, Carter B, et al. Subarachnoid hemorrhage without evident cause on initial angiography studies: diagnostic yield of subsequent angiography and other neuroimaging tests. J Neurosurg 2003;98:1235-1240). Detecting these aneurysms is imperative to avoid repeat hemorrhage. Rarely, one is able to document the phenomenon of the disappearance and subsequent reappearance of the ruptured aneurysm. CASE DESCRIPTION: This is a case report of subarachnoid hemorrhage (SAH) in which a cerebral aneurysm of the M1 segment of the left proximal middle cerebral artery was initially detected by CTA at an outside hospital only to evade detection with both CTA and DSA at our institution. Repeat DSA 1 week later revealed the culprit aneurysm, which was then treated endovascularly. CONCLUSIONS: Patients with significant SAH and negative DSA findings should be considered for further diagnostic testing including CTA or repeat DSA. The current literature supports the strategy used at our institution of initial CTA and DSA in the setting of SAH, and then subsequent repeat DSA as warranted if the initial studies are nondiagnostic. Timing of repeat examination, as demonstrated in this case, should favor a shorter time course

OBJECTIVE: The outcomes reported in the International Subarachnoid Aneurysm Trial (ISAT), a multicenter, prospective, randomized trial to directly compare surgical clipping with endovascular coiling as treatments for ruptured intracranial aneurysms, have been misinterpreted by many to indicate the superiority of coiling to surgical clipping in all instances. To better understand the results of ISAT and their implications for practice patterns, we compared the ISAT results with the results of other published studies regarding the treatment of ruptured intracranial aneurysms. METHODS: Data from 19 published studies were compared with each other and with ISAT results. Outcomes examined were overall rates of mortality, rebleeding, poor outcome (disability and death), procedural complication rates, and rates of reoperation and nontotal occlusion. RESULTS: In the 19 published studies, mean procedural complication rates were similar (surgical clipping, 11%; endovascular coiling, 9%); ISAT did not report procedural complications. ISAT rates were within the range of the other studies for overall mortality, total rebleeding, and poor outcome. Reoperation rates in the other studies were similar to those of ISAT (endovascular coiling, 12.5%; surgical clipping, 3.4%). The ISAT rate for less than 100% occlusion for endovascular coiling (6%) was below the range in the other studies (8.3-70.4%). CONCLUSION: Discrepancies with the results of other published studies, procedural limitations in study design, and lack of some data endpoints and subgroup analysis raise concerns regarding extracting generalizations from the conclusions of ISAT. We think that the creation of a national registry would further the study of treatment of ruptured intracranial aneurysms

Cerebral vasospasm is a major cause of morbidity and mortality associated with subarachnoid hemorrhage (SAH). Advances in neuroimaging and development of newer intraparenchymal monitoring devices have improved the prediction and diagnosis of cerebral vasospasm significantly. Recent experimental and clinical trials have increased the armamentarium of preventive and treatment strategies for cerebral vasospasm. Vasospasm refractory to medical therapy usually is treated endovascularly with percutaneous transluminal balloon angioplasty (PTA) for proximal vessel vasospasm and vasodilator infusion for distal vessel vasospasm. Although vasospasm usually does not recur after PTA, recurrence is frequent after vasodilator infusion. The development of newer microballoon catheters has led to improvements in treatment of not only proximal but also distal vessel vasospasm with balloon angioplasty. This article reports on current knowledge in the diagnosis, prediction, prevention, and management of cerebral vasospasm

The authors report a case of preoperative embolization and resection of a choroid plexus papilloma of the lateral ventricle in a 4-month-old boy. These vascular tumors of the central nervous system present a significant intraoperative bleeding risk. Attempts at preoperative embolization to reduce the bleeding risk have rarely succeeded because of the small and tortuous vessels feeding these tumors in infants. The case presented here supports the feasibility of preoperative embolization as a therapeutic adjunct in infants

Cerebral vasospasm remains a serious complication of aneurysmal subarachnoid hemorrhage. Efforts in improving its clinical outcome have been focused on early diagnosis and applying effective treatment regimens. Standard diagnostic modalities currently used do not fully address this complex disease. The use of CT angiography and CT perfusion are discussed, with emphasis on its potential role in not only detecting vasospasm, but also in guiding management decisions and assessing clinical outcome

OBJECTIVE: The role of intraoperative angiography (IA) in the surgical treatment of cerebral aneurysms has remained extremely controversial. We determine the frequency and predictors of unanticipated findings necessitating clip adjustment established on postoperative angiography (PA) in a consecutive series of 147 aneurysms. On the basis of published series, we discuss the utility, safety, accuracy, and cost effectiveness of adjunct IA in the surgical treatment of cerebral aneurysms. METHODS: We retrospectively examined the charts of 124 consecutive patients harboring 147 aneurysms that were surgically clipped between December 2000 and March 2005 and had PA available for review. Patient demographics, aneurysm size, location, Hunt and Hess score, Fisher grade, mode of aneurysm discovery, time between discovery and surgery, and PA results, as determined by a blinded independent neuroradiologist, were recorded. RESULTS: PA demonstrated two (1.4%) unexpected residuals, four anticipated residuals (2.7%), and four (2.7%) vessel compromises. Of the six unanticipated outcomes, two of two (100%) unexpected residuals and three of four (75%) vessel compromises were from large aneurysms (P = 0.0001 each). Middle cerebral artery aneurysms comprised 5 of 10 (50%) imperfect outcomes (three expected remnants and two vessel occlusions), which trended toward significance (P = 0.06). CONCLUSION: IA is recommended during the surgical clipping of complex or large aneurysms and some middle cerebral artery aneurysms. High cost-benefit ratio, false-negative rate, and moderate risk, however, preclude routine use. With future technological advances, IA may warrant broader use by replacing postoperative studies in the neurosurgical management of intracranial aneurysms