In vitro evaluation of papaverine hydrochloride incompatibilities: a simulation of intraarterial infusion for cerebral vasospasm.

PURPOSE: To elucidate, in light of reports of complications associated with intraarterial infusion of papaverine hydrochloride, the known propensity of papaverine hydrochloride to form precipitate in combination with other solutions or pharmaceuticals. METHODS: Initially simulating a situation experienced during an intraarterial papaverine infusion for cerebral vasospasm, we mixed various concentrations of papaverine with serum, nonheparinized and heparinized saline, and nonionic contrast material. RESULTS: Papaverine in concentrations of 0.3% (300 mg/100 mL of normal saline) or greater formed a precipitate when mixed with human serum (blood). The precipitate crystals were 50 to 100 microns in size and could be returned to solution simply by the addition of more serum. CONCLUSION: Crystal emboli are a possible transient cause of complications experienced during treatment of vasospasm with its attendant altered flow dynamics.

Hydrophilic coatings diminish adhesion of glue to catheter: an in vitro simulation of NBCA embolization.

PURPOSE: To determine whether new hydrophilic microcatheter coatings exhibit characteristics that diminish the chance of permanent endovascular glue adhesion during liquid acrylic embolization. METHODS: Common hydrophilic and nonhydrophilic microcatheters (both flow-directed and over-the-wire) used in neurointerventional procedures were evaluated in vitro for liquid acrylic (Histoacryl and Avacryl)-to-catheter bond strength, catheter endovascular friction, and catheter stretch (tensile strength). Sufficient test repetitions were acquired to achieve statistical significance. RESULTS: The bond strength between hydrophilically coated catheters and NBCA was significantly weaker than between nonhydrophilic catheters and NBCA. Hydrophilic catheter coating reduced dynamic endovascular friction by 30% to 35%. All flow-directed catheters exhibited considerably more stretch (less tensile strength) and therefore were more prone to fracture during withdrawal than over-the-wire systems. Histoacryl bonded to both hydrophilic and nonhydrophilic catheters with a significantly greater force than did Avacryl. CONCLUSION: Hydrophilically coated catheters should be less likely to exhibit permanent endovascular fixation during acrylic embolization because of a weaker catheter-NBCA bond and because of reduced catheter friction (allowing a larger portion of any applied catheter withdrawal force to be transmitted to the catheter tip with less force dissipated along the catheter resulting in stretch). A significant difference in NBCA types (Histoacryl and Avacryl) was discovered: Avacryl developed a significantly weaker bond with all catheter types.

Role of intraoperative angiography in the surgical treatment of cerebral aneurysms.

UNLABELLED: The benefit of using intraoperative angiography (IA) during aneurysm surgery is still uncertain. OBJECT: In this prospective study, the authors evaluate the radiographically demonstrated success of surgical treatment in 151 consecutive patients harboring 173 aneurysms who selectively underwent IA examination. The authors also assess the frequency with which IA led to repositioning of the aneurysm clip. METHODS: Intraoperative angiography was used selectively in this series, based on the surgeon's concern about the potential for residual aneurysm, distal branch occlusion, or parent vessel stenosis. Specific variables were analyzed to determine their impact on the incidence of clip repositioning and the accuracy of IA was evaluated by direct comparison with postoperative angiography (PA) in 90% of the cases in which IA was used. CONCLUSIONS: The selective use of IA led to successful treatment as shown by PA, with a low incidence of unexpected residual aneurysm (3.2%), distal branch occlusion (1.9%), and parent vessel stenosis (0%). Intraoperative angiography led to immediate repositioning of the aneurysm clip in 27% of the cases. Anterior cerebral artery aneurysms required clip repositioning less often and superior hypophyseal artery aneurysms required repositioning more often than aneurysms in other locations. Large and giant aneurysms required clip repositioning more often than small aneurysms; however, they were also more likely to display false success on IA as determined by PA. Aneurysms arising along the internal carotid artery were more likely to display successful clipping on IA, as determined by PA, than were aneurysms in other locations. The results of this series support the selective use of IA in the treatment of complex aneurysms, particularly large and giant aneurysms as well as superior hypophyseal artery aneurysms. As measured by PA, IA will improve the outcome of these patients.

Ruptured Giant Basilar Artery Aneurysm in a Comatose Adolescent: Successful Obliteration Using Intraoperative SSEP, BAER, and MEP Monitoring. A Case Report.

SUMMARY: Giant basilar aneurysms are infrequently seen in children. We present the endovascular management of an adolescent who presented comatose with pinpoint pupils due to a ruptured giant basilar trunk aneurysm. A noncontrast head CT disclosed a large prepontine lesion with brainstem hemorrhage. Catheter angiography showed a 4.5 cm irregular, fusiform basilar trunk aneurysm. With SSEP, BAER, and MEP monitoring, the patient underwent bilateral temporary vertebral artery occlusion, followed by GDC embolization of the aneurysm. Postprocedure internal carotid angiograms showed adequate blood supply to the basilar apex via patent posterior communicating arteries. On postprocedure day two, the patient was following commands. The remainder of his hospital course was uneventful. Postoperative angiograms showed no residual filling of the aneurysm. At 12 months the patient was neurologically intact and at baseline function as an honor student and follow-up angiogram showed persistent occlusion of the aneurysm from the circulation. Successful endovascular treatment has been considered a less invasive and safer alternative to surgical management of some complex vascular lesions. While most reports on reversing basilar artery flow have been carried out in awake patients with neurological examinations, this is not possible in a patient presenting in a comatose state. This report suggests that SSEPs, BAERs and MEP may be of use in such patients in safely carrying out basilar artery occlusion.

Arteriovenous fistula of the scalp after hair transplantation treated by endovascular embolization.

A 27-year-old patient acquired an arteriovenous fistula after punch graft hair transplantation. This lesion was treated by (percutaneous) puncture and injection of a liquid acrylic (N-butyl-2-cyanoacrylate). The fistula was completely obliterated by the endovascular therapy without the need for additional vascular or cosmetic surgery. Endovascular therapy may be helpful as an adjunctive or primary treatment modality for iatrogenic or post-trauma fistulas.