Preoperative embolization of cerebral arteriovenous malformations with silk sutures: analysis and clinical correlation of complications revealed on computerized tomography scanning.

OBJECT: The aim of this study was to determine the incidence and clinical significance of complications related to preoperative embolization of cerebral arteriovenous malformations (AVMs) with silk sutures as documented on postprocedure computerized tomography (CT) scans. METHODS: The CT scans were obtained within 12 to 24 hours after 221 (96%) of 230 consecutive embolizations in 70 patients. These CT scans were evaluated for the presence of ischemia, infarction, hemorrhage, or contrast agent extravasation. Adverse patient outcomes were determined after each embolization and were correlated with CT findings. New abnormalities demonstrated on CT scans were also correlated with the Spetzler-Martin AVM grade, degree of arteriovenous shunting, and location. New abnormalities, the majority of them infarcts, resulted from 29 (13%) of 221 embolization procedures. In 11 (38%) of 29 cases of new CT findings, patients were asymptomatic, including 10 with new infarcts on CT scans. New neurological deficits occurred in 20 (8.7%) of 230 total embolization procedures in 19 patients, including one death. Permanent deficits occurred in nine patients (3.9% per embolization procedure, 12.8% per patient). Of the patients with new neurological deficits, 18 (90%) of 20 embolization procedures resulted in new abnormalities on CT scans. Two patients with new transient neurological deficits had no new findings on CT scans. Spetzler-Martin grade, AVM location, degree of arteriovenous shunting, and higher numbers of procedures were not statistically associated with a higher incidence of abnormalities on CT scans or new permanent neurological deficits. CONCLUSIONS: Silk sutures are an effective and relatively safe embolic agent. After brain AVM embolization with silk sutures, new abnormalities were found on CT scans obtained in one of eight procedures. When a new CT finding occurred, the patient had roughly equal chances of having no new symptoms, having new transient neurological deficits, or having new permanent neurological deficits.

Sacral plexus: optimal imaging planes for MR assessment.

PURPOSE: To identify the optimal imaging planes for magnetic resonance (MR) evaluation of the sacral plexus (SP) and proximal sciatic nerve (SN). MATERIALS AND METHODS: The SPs of 10 health adult volunteers were prospectively studied with T1-weighted MR imaging with custom-built pelvic phased-array coils. The conspicuity of 12 anatomic characteristics (comprising the SP and their relationship to normal pelvic anatomy) on a series of coronal, axial, and oblique images was graded. Results were evaluated with the Kruskal-Wallis and Wilcoxon signed rank tests. RESULTS: At least two planes were necessary to assess the anatomy of the SP and SN. Analysis of average conspicuity scores showed that the direct coronal and direct axial planes were the best overall and were superior to other imaging planes in the demonstration of the L-4 and L-5 ventral rami, the lumbosacral trunk, the S-1 contribution to the SN, and the SN in the greater sciatic foramen. The sacral coronal plane was best for the visualization of the bony sacrum, sacral foramina, and proximal S-1 to S-4 nerve roots. The remaining imaging planes had limited utility. CONCLUSION: MR imaging with a combination of direct coronal and direct axial planes enables thorough evaluation of all components of the SP and proximal SN.

Color flow sonographic mapping of intravascular extension of malignant renal tumors.

The purpose of this study was to evaluate the possible role of CDFI in identifying malignant renal tumor thrombus in the renal vein or the IVC. This study involved 24 tumors in 23 patients, including 19 renal cell carcinomas, four Wilms' tumors, and one rhabdoid tumor. CDFI had an overall sensitivity of 95% in predicting combined renal vein and IVC tumor involvement but was more sensitive in the renal vein alone (100%) than in the IVC alone (89%). Specificity of CDFI was nearly equal for both renal vein and IVC thrombus at 85%. The main limitation of CDFI was its inability to predict venous tumor extension in large or bulky tumors. We would recommend CDFI as a method of detecting renal vein or IVC thrombus at the time of initial real-time sonographic detection of tumor. When CT or MR imaging is equivocal, CDFI may be used to predict tumor thrombus in the renal vein or IVC.