Local Effects of Papaverine on Normal, Atherosclerotic, and Vasospastic Carotid Arteries of Rabbits: An Experimental Study

Objective: Papaverine is a direct-acting vasodilating agent that is frequently used in the treatment of vasospasm after subarachnoid hemorrhage. However, not much knowledge is available about the effect of papaverine on atherosclerotic vessels.Material and Methods: Twenty-four New Zealand-type male rabbits were divided into 4 groups: normal, atherosclerotic, normal vasospastic, and atherosclerotic vasospastic vessels. The atherosclerotic groups (2 and 4) were fed with high cholesterol diet and the other groups with a normal diet for 4 weeks. Cholesterol levels were measured before and after exposure to these diets. In groups 3 and 4, a vasospasm model for common carotid arteries was established. In all subjects, papaverine was applied topically on the left common carotid artery (study subgroups a) and serum physiologic on the right (control subgroups b). Before and 10, 20, 30, 40, 50, and 60 minutes after topical application, vessel diameter was measured and compared between the groups. Histological evaluation of the artery was also performed in all subjects.Results: In the atherosclerosis groups (Groups 2 and 4), blood cholesterol levels were significantly higher after 4 weeks of high cholesterol diet. Atherosclerosis and vasospasm development were confirmed with histological examination in the respective groups. Papaverine application lead to significant dilation in all groups according to the SF application. Its most prominent vasodilating effect was seen in normal vessels, while its effect gradually decreased from groups 2 to 4.Conclusions: The vasodilating effect of papaverine decreased in the presence of atherosclerosis. New experimental and clinical studies are required to determine the effective local papaverine doses in atherosclerotic cases

Toxicity of Radiosurgery for Brainstem Metastases

Background Although stereotactic radiosurgery (SRS) is an effective modality in the treatment of brainstem metastases (BSM), radiation-induced toxicity remains a critical concern. To better understand how severe or life-threatening toxicity is affected by the location of lesions treated in the brainstem, a review of all available studies reporting SRS treatment for BSM was performed. Methods Twenty-nine retrospective studies investigating SRS for BSM were reviewed. Results The rates of grade 3 or greater toxicity, based on the Common Terminology Criteria for Adverse Events, varied from 0 to 9.5% (mean 3.4 ± 2.9%). Overall, the median time to toxicity after SRS was 3 months, with 90% of toxicities occurring before 9 months. A total of 1243 cases had toxicity and location data available. Toxicity rates for lesions located in the medulla were 0.8% (1/131), compared with midbrain and pons, respectively, 2.8% (8/288) and 3.0% (24/811). Conclusions Current data suggest that brainstem substructure location does not predict for toxicity and lesion volume within this cohort with median tumor volumes 0.04–2.8 cc does not predict for toxicity

Utilization of Intraoperative Motor Mapping in Glioma Surgery with High-Field Intraoperative Magnetic Resonance Imaging

Background/Aims: The main goal of glioma surgery is to maximize tumor resection while minimizing neurologic injury. The use of high-field intraoperative magnetic resonance imaging (iMRI) and intraoperative cortical mapping (IOM) together enable the surgeon to increase the extent of tumor resection (EOR) and preserve the neurological function. However, there is insufficient evidence to validate the use of IOM with high-field iMRI. Methods: To study the safety and utility of IOM in a high-field (1.5 T) iMRI suite, we retrospectively studied 38 patients with glioma who underwent surgery with IOM in the iMRI suite. Results: We were able to use IOM in the iMRI suite without any adverse side effects or difficulty. Median EOR was 97%. A new or worsening motor deficit occurred in 14 (37%) patients immediately after the surgery, with 3 (8%) patients exhibiting persistent deficit at 6 months. Conclusion: Our findings suggest that IOM can be successfully used in a high-field MRI environment and can help minimize postoperative motor deficit with a higher EOR. Copyright (C) 2010 S. Karger AG, Base