Carotid endarterectomy with regional anesthesia.

The senior author (REH) has changed his technique for performing carotid endarterectomy from the use of general anesthesia to the use of cervical block anesthesia. Because a randomized study was not performed, it is difficult to separate effects of increased surgical experience from those caused by a change in anesthetic regimen. Nonetheless, there has been a substantial decrease in complications, length of hospital stay, and costs concomitant with the change to regional anesthesia; we think there is a causal relationship. The use of cervical block anesthesia has practically eliminated the non-stroke-related complications associated with carotid endarterectomy in our practice. The technique for performing carotid endarterectomy under cervical block anesthesia is described in detail.

Clinical outcomes of aneurysmal subarachnoid hemorrhage patients treated with oral diltiazem and limited intensive care management.

BACKGROUND: Aneurysmal subarachnoid hemorrhage (SAH) patients are frequently treated with prophylactic nimodipine and undergo invasive monitoring of blood pressure and volume status in an intensive care unit (ICU) setting to decrease the incidence of delayed ischemic neurological deficit (DIND) and improve functional outcomes. The goal of this study was to examine the incidence of DIND and poor functional outcomes in a consecutive series of SAH patients treated with a different regimen of prophylactic oral diltiazem and limited use of intensive care monitoring. METHODS: The study involved a consecutive series of 123 aneurysmal SAH patients treated by the senior author who were admitted within 72 hours of hemorrhage and who never received nimodipine or nicardipine. Functional outcomes were graded using the Glasgow Outcome Scale (GOS). RESULTS: Of the 123 patients identified, favorable outcomes (GOS 4 and 5) were achieved in 74.8%. The incidence of DIND was 19.5%. Hypertensive, hypervolemic, hemodilutional (HHH) therapy was used in 10 patients (8.1%) and no patients were treated for DIND by endovascular means. Seven patients (5.7%) had a poor functional outcome or death because of DIND and two of these were related to complications of HHH therapy. These results were compared to contemporary series of SAH patients managed with other treatment protocols. CONCLUSIONS: Functional outcomes of patients treated with a regimen of oral diltiazem, limited use of ICU monitoring and HHH therapy for DIND compare favorably with other contemporary series of SAH patients.

History of outcomes measures in neurosurgery.

This article provides a brief overview of the history of the origin of surgical outcomes studies in North America as exemplified by the career of E. A. Codman, MD. The influence of Harvey Cushing on Codman's interest in documenting the end results of surgical care is reported. The lessons gained from Codman's experience and difficulties are related to the efforts of the American Association of Neurological Surgeons/Congress of Neurological Surgeons Outcomes Committee to develop an international neurosurgical outcome reporting system.

Decision analysis for small, asymptomatic intracranial arteriovenous malformations.

OBJECT: Asymptomatic intracranial arteriovenous malformations (AVMs) represent a clinically challenging problem because of the complex decision making that must be undertaken prior to beginning any type of treatment. In addition, the relative infrequency of these lesions means that there is relatively little experience reported in the literature. The authors use a decision-analysis technique to model the considerations that go into determining the treatment of these lesions in an effort to quantify the various risks and overall benefits conferred by the following three treatment strategies: observation/natural history, microsurgery, and stereotactic radiosurgery. METHODS: The authors conducted a thorough literature search to elucidate the risks and outcomes associated with each treatment option. These values were used to build and run a comprehensive Markov model to determine a base-case analysis. All of the input variables were also subjected to sensitivity analysis to identify the most influential input variables and the crossover points in which favored strategies changed. The base-case analysis suggested that microsurgery was the favored treatment option because this hypothetical cohort accumulated 21.53 quality-adjusted life years (QALYs) over the course of the model compared with the 16.97 QALYs and 16.40 QALYs for stereotctic radiosurgery and observation, respectively. Sensitivity analysis demonstrated that overall major neurological morbidity and mortality were the most influential input variables both perioperatively and during the radiosurgical "latent" period (that is, up to 2 years posttreatment). The maximum acceptable perioperative combined major neurological morbidity and mortality rate was 6.8%. The latent period combined major neurological morbidity and mortality would need to be 0.7% to make radiosurgery favorable in this analysis. CONCLUSIONS: Results of this decision analysis model suggest that microsurgery in the hands of experienced cerebrovascular surgeons, who can expect a less than 6.8% combined rate of major neurological morbidity and mortality, offers patients a greater overall quality of life over time.

Quality assurance in neurosurgery: United States concepts.

At present, quality assurance in United States neurosurgery is based primarily on neurosurgeons meeting requirements for certification by the American Board of Neurological Surgery and residency training programs meeting requirements for approval by the neurosurgical Residency Review Committee. These organizations, plus a number of other private, autonomous, physician directed groups have assumed responsibility for assuring neurosurgical quality. There are, however, no reliable data that such processes are effective and it is likely that neurosurgical quality assurance will move toward outcomes based documentation in the future. This article presents a brief review of the concepts of quality assurance and assessment as they are applied in the healthcare system of the United States. A more detailed review of the process of neurosurgical credentialing is also presented and a paradigm for evaluating and improving neurosurgical quality is proposed. It must be clearly stated that the opinions expressed in this article are those of the author and do not represent the official position of any neurosurgical organization.

Pure lesionectomy versus tailored epilepsy surgery in treatment of cavernous malformations presenting with epilepsy.

Cerebral cavernous malformations (CM) are well-circumscribed vascular malformations that often present with epileptic seizures. Although patients may initially benefit from antiepileptic drugs, surgical treatment may become necessary due to medically intractable seizures. However, it is unclear whether lesionectomy alone or tailored epilepsy surgery with previous invasive monitoring is the optimal strategy in such cases. We report two patients with epileptic seizures due to CM. One patient with few seizures prior to surgery became seizure-free following resection of the CM and the surrounding tissue. In the second patient with long-lasting epilepsy, lesionectomy was performed because of the proximity to a functioning left hippocampus. This limited resection failed and the patient still had seizures. Subsequently, invasive monitoring with intracranial depth and strip electrodes was performed in order to localize the epileptogenic area and determine whether the left hippocampus could be spared. The invasive study showed the seizure origin in the tissue around the former CM but no epileptic discharges in the hippocampus. In a second operation, an anterior temporal resection was performed with removal of the epileptogenic surrounding tissue and the patient became seizure-free without cognitive deficits. The optimal surgical strategy for CM presenting with epileptic seizures must take into account various factors such as underlying mechanisms and duration of epilepsy, and location of the lesion.

Carotid endarterectomy using regional anesthesia.

The author has had considerable experience with the use of general anesthesia and regional anesthesia for patients undergoing carotid endarterectomy. His experience and a review of the literature indicate that the use of regional anesthesia significantly reduces the incidence of nonsurgical complications following operation. A particularly robust effect is placed on reducing cardiopulmonary complications.

Outcomes analysis of the treatment of carotid artery disease.

The author presents a brief review of the methodologies of outcomes analysis. Recent large database outcomes studies on patients undergoing carotid endarterectomy are also reviewed and compared with the data generated from two prospective randomized studies, and large database outcomes analysis are discussed. The efforts of the American Association of Neurological Surgeons and the Congress of Neurological Surgeons Outcomes Committee to perform online, multicenter outcomes studies are reviewed.

Clinical outcomes after carotid endarterectomy: comparison of the use of regional and general anesthetics.

OBJECT: The authors analyzed their series of carotid endarterectomies (CEAs), which were performed after administration of either a general or regional anesthetic, to determine whether the choice of anesthetic affected patients' clinical outcomes and length of hospital stay. METHODS: A series of 803 consecutive CEAs performed between July 1990 and February 1999 was reviewed. Cases were analyzed for patient demographics, comorbid medical states, and perioperative complications. Contingency-table statistical analysis was used to compare the incidence of comorbid medical states and perioperative complications between patients who underwent CEA in which either a regional or general anesthetic was used. Student's t-test was used to compare the length of hospital stay and mean patient age. A regional anesthetic was used for 632 CEAs, and a general anesthetic was used for 171 operations. There were no statistically significant intergroup differences in demographics or comorbid medical states. The incidence of perioperative stroke and death did not differ significantly between the regional (2.7%) and the general anesthetic groups (2.3%). However, the incidence of nonneurological, nonfatal complications was significantly less in the regional anesthetic (1.6%) than in the general anesthetic group (14.6%, p<0.0001). Patients undergoing CEA in which a regional anesthetic was used had a significantly lower incidence of cardiopulmonary complications (myocardial infarction and postoperative intubation), cervical complications (neck hematomas and cranial nerve injuries), and urological complications (urinary retention) than patients who underwent surgery after receiving a general anesthetic. CONCLUSIONS: Patients undergoing CEA in which a regional anesthetic was used had significantly fewer nonneurological, nonfatal complications, particularly cardiopulmonary complications, than similar patients surgically treated after induction of general anesthesia.

Clinical outcomes for patients at high risk who underwent carotid endarterectomy with regional anesthesia.

OBJECTIVE: To compare the clinical outcomes for patients with carotid artery stenosis with advanced age, diabetes mellitus, atherosclerotic coronary vascular disease, and contralateral internal carotid artery occlusion who underwent carotid endarterectomy (CEA), using regional anesthesia, with the outcomes for patients without these risk factors. METHODS: A prospective series of 600 CEAs performed using regional anesthesia was analyzed. All patients were surgically treated under the direction of one neurosurgeon, in an academic medical center. Clinical outcome measures were any stroke, death, or cardiac morbidity within 30 days after surgery. All patients were monitored until a clinical end point was reached and/or 6 weeks had elapsed after surgery. The incidence of adverse clinical outcomes among the suspected high-risk patients was compared with the incidence for the entire series using contingency-table analysis (chi2 and Fisher's exact tests). RESULTS: Fifteen strokes (2.5%), three cardiac complications (0.5%), and two deaths (0.3%) occurred within 30 days after CEA. None of the suspected risk factors was associated with a significantly (P < 0.05) increased risk of perioperative morbidity or death. CONCLUSION: CEA using regional anesthesia can be performed for patients with advanced age, diabetes mellitus, atherosclerotic coronary vascular disease, and contralateral internal carotid artery occlusion, with acceptably low perioperative morbidity rates.

Venous hypertension associated with a posterior fossa dural arteriovenous fistula: another cause of bithalamic lesions on MR images.

We report a case of a posterior fossa arteriovenous fistula (AVF) with bithalamic hyperintensity of MR images. The thalamic abnormality improved after surgery, suggesting reversible venous hypertension as the pathogenesis of the finding, as opposed to infarction. This manifestation of a posterior fossa AVF should be considered in the differential diagnosis of bilateral thalamic disease.

Colloid cyst of the third ventricle: sometimes more conspicuous on CT than MR.

We present two cases of surgically proved colloid cysts that were more apparent on CT scans than on MR images. These cysts, while hyperdense on CT scans, were nearly isointense with brain on multiple MR sequences. This relative lack of visibility represents a potential pitfall when imaging a patient with headache.

Microsurgical treatment of arteriovenous malformations: analysis and comparison with stereotactic radiosurgery.

OBJECT: To compare microsurgical and stereotactic radiosurgical treatment of arteriovenous malformations (AVMs), the authors analyzed a prospective series of 72 consecutive patients who were treated microsurgically for cerebral AVMs by one neurosurgeon. The authors then compared the results of microsurgical treatment with published results of stereotactic radiosurgical treatment of small AVMs. METHODS: Patients were categorized by age, gender, presentation, and preoperative neurological status. The AVMs were categorized by size, location, presence of deep venous drainage, and Spetzler-Martin grade. Outcome was assessed for angiographic obliteration, hemorrhage following treatment, presence of a new, persistent postoperative neurological deficit, and Glasgow Outcome Scale (GOS) score. Ordinal logistic regression was used to model the GOS score and to predict new postoperative deficits. Generalized estimating equations were used to compare published results of microsurgical and stereotactic radiosurgical treatment of AVMs. Kaplan-Meier event-free survival plots were generated to compare the two modalities with respect to hemorrhage following treatment. Overall, six patients (8.3%) exhibited a new persistent neurological deficit postoperatively. Sixty-five patients (90.3%) had a GOS score of 5. Three patients were moderately disabled and four patients were severely disabled. No patient was observed to be in a vegetative state and there were no treatment-related deaths. Seventy-one patients (98.6%) underwent intra- or postoperative angiography. Total excision of the AVM was angiographically confirmed in 70 patients (98.6% of those who underwent angiography). To date no patient has suffered from hemorrhage since the microsurgical treatment. When analysis was confined to patients whose AVMs were smaller than 3 cm in maximum diameter, the authors found a 100% angiographic obliteration rate, no new postoperative neurological deficit, and a good recovery in all patients. An analysis of all patients with Spetzler-Martin Grades I to III resulted in a 100% rate of angiographic obliteration, one patient with a new postoperative neurological deficit, and good recovery in 93% of the patients. Size of the AVM, preoperative neurological status, and patient age are associated with GOS score (for all, p < 0.02). The Spetzler-Martin grading system as well as each component of this system are associated with the development of a new postoperative neurological deficit (for all, p < 0.01). For the entire series there were fewer postoperative hemorrhages and deaths than those mentioned in published series of small AVMs treated with stereotactic radiosurgery. When these patients and published series of patients with microsurgically treated AVMs classified as Grade I to III were compared with similar patients treated radiosurgically there were significantly fewer postoperative hemorrhages (odds ratio = 0.210, p = 0.001), fewer deaths (odds ratio = 0.659, p = 0.019), fewer new posttreatment neurological deficits (odds ratio = 0.464, p = 0.013), and a higher incidence of obliteration (odds ratio = 28.2, p = 0.001) for the microsurgical group. Lifetable analysis confirms the statistically significant difference in hemorrhage-free survival time between the two groups (p = 0.002). CONCLUSIONS: Based on this analysis, microsurgical treatment of Grades I to III AVMs is superior to stereotactic radiosurgery.