Surgical excision of giant cerebellar hemispheric arteriovenous malformations following preoperative embolization. Report of two cases

Giant diffuse cerebellar AVM: managing ultimate intraoperative challenges

Surgery within the posterior cranial fossa uniquely requires excellence in microsurgical technique, given the complexity of the neurovascular structures housed within this region. Arteriovenous malformations (AVMs) within this region represent the greatest surgical challenge because of the difficulty in resecting an AVM completely while preserving the highly eloquent surrounding structures. The AVM in this video exemplifies a surgeon's "most challenging case," a surgery that spanned two stages, including 14 hours of resection, but concluded with complete resection despite the complexity of deep arterial and dural feeders. The video can be found here: https://youtu.be/WNBuwFHSrQ0.

Combined embolization and microsurgery for cerebral arteriovenous malformation

Thirty-seven of 396 patients with arteriovenous malformations (AVMs) were treated by preoperative embolization and surgical excision in our medical center between 1991 and 1997. The AVMs were Spetzler-Martin grade I in six, grade II in 11, grade III in 12, grade IV in four, and Grade V in four. A total of 69 embolization procedures were performed using estrogen alcohol and polyvinyl acetate as liquid embolization materials. AVM grades improved following embolization in 10 patients. Three hemorrhages occurred several days after the final embolization, probably due to hemodynamic stress on the unoccluded perforating feeders or drainer occlusion. Surgical resection was performed under guidance of intraoperative digital subtraction angiography. Although the AVMs were excised totally in one stage with no major neurological deficits, normal perfusion pressure breakthrough occurred in a patient with prominent collateral circulation of the AVM which developed after the main feeder embolization. Preoperative staged embolization with estrogen alcohol and polyvinyl acetate is effective to expand the surgical indication and to achieve complete resection of difficult AVMs. Direct surgery should be performed as soon as possible if hemodynamic changes are observed following embolization.

Persistent feeding arteries to angiographically completely embolized arteriovenous malformation demonstrated by intraoperative color-flow Doppler testing: report of two cases

Two cases of arteriovenous malformation (AVM) treated preoperatively by endovascular embolization that appeared to be completely occluded after embolization are presented. Seven and 12 days later, respectively, these patients underwent resection of their AVM. At the time of surgery, intraoperative color-flow Doppler studies revealed persistent feeding arteries to an active residual nidus of the AVM. The significance of this finding is presented in light of previous published literature.

Hydrophilic polymer-coated guide wire combined with progressive suppleness pursil catheter for safer, more definitive embolisation of arteriovenous malformations

For safe, more definitive embolisation of arteriovenous malformations, improved selectivity of the catheter is desirable. This report describes the advantage of the combined use of a progressive suppleness pursil catheter and a hydrophilic polymer-coated guide wire, together with precaution against complications. In 14 patients, 27 vessels were catheterised with this. Chemical embolisation using oestrogen alcohol and polyvinyl acetate was carried out only if sufficiently superselective catheterization was achieved with negative results on a provocation test. Chemical embolisation was successful in 25 vessels, but in three vessels catheterised very distally, it required much more time to withdraw the catheter because of the friction between it and the wall of the vessel.

Combined endovascular and neurosurgical approach for paraclinoid internal carotid artery aneurysms

The authors review the surgical management of nine complex paraclinoid aneurysms treated with the endovascular balloon catheter technique. With the patient under general anesthesia, the balloon catheter was guided into the feeding artery of the aneurysm by the Seldinger technique. After the aneurysm was exposed, the balloon was inflated temporarily to prevent premature rupture and to facilitate the dissection of the aneurysm. For the larger paraclinoid aneurysm, the double-lumen catheter was introduced into the cervical internal carotid artery (ICA). After temporarily trapping the aneurysm by balloon occlusion of the cervical ICA and clipping the intracranial ICA distal to the aneurysm, retrograde aspiration was performed to collapse the aneurysm. The complete collapse of the large aneurysm by this technique allows an easier dissection of the aneurysm and a safer application of suitable clips. Such a retrograde suction decompression method was used in six large aneurysms. Intraoperative digital subtraction angiography was performed in all cases after the aneurysmal clipping; in three aneurysms, repositioning the clip was required. Only one case of embolic complication was related to the vessel catheterization in this series, which was discovered during the operation. An embolectomy was performed immediately, and there were no postoperative sequelae. We conclude that the combined endovascular and neurosurgical approach, particularly for the large ICA aneurysms, which are difficult to control proximally, can be a useful method of treatment. To prevent complications related to thrombus formation, further refinement in the balloon catheter itself is still needed.

The combined management of cerebral arteriovenous malformations. Experience with 100 cases and review of the literature

A series of 100 patients treated for a cerebral arteriovenous malformation (AVM) is presented. Patients were admitted between 1985 and April 1992. Two groups are considered: the first group including 52 patients treated before the availability of radiosurgery (1985-1988), and the second group including 48 patients treated after the availability of radiosurgery (1989-1992). AVM's were classified in five grades according to the Spetzler's Grading System. Three techniques of treatment were used: surgical resection, intravascular embolization (with cyanoacrylate), and radiosurgery (linear accelerator). These three techniques were used either alone or in association, giving four types of management: surgical resection alone, embolization and resection, embolization alone, and radiosurgery (alone, or after embolization, or after surgical resection). From 1989 on, the availability of radiosurgery was responsible for the decrease of the "embolization and resection" group, which until then was predominantly used as well for low-grade (I, II, III) as for high-grade AVM's (IV, V). Overall, for the low-grade AVM's, the treatment of choice was surgical resection (79% of cases), with pre-operative embolization in one-half of these cases; the other low-grade AVM's were irradiated, with various combinations. For the high-grade AVM's, the treatment of choice was intravascular embolization (95% of cases), either alone, or followed by resection (45%) or radiosurgery (9%). Results were evaluated in terms of deterioration following treatment, in five groups: no deterioration (59%), minor deterioration (20%), long-lasting deficit (10%), major deterioration (5%), and death (6%). Overall, results improved after 1989: favourable outcome (no deterioration and minor deterioration) increased from 67% to 90%. Results were not related to the patients' age. More favourable results were obtained for low-grade AVM's (93%) than for high-grade AVM's (60%). For the low-grade AVM's the evolution from 1989 on (favourable outcomes increasing from 89% to 96%) occurred with the lowering of the mortality rate. For the high-grade AVM's, the evolution from 1989 onwards (favourable outcome increasing from 46% to 78%) occurred with the decrease of the cases with deficits. The angiographic results were strongly related to the management: 95% of complete eradication after surgical resection and 5% only after embolization alone. Concerning the results in irradiated cases, the follow-up is not long enough. The review of the neurosurgical literature since 1972 demonstrates progressive modifications in the therapeutic attitude as regards AVM's. The surgical management which was predominantly used at the beginning gave way progressively to a combined management, with a combination of embolization, surgery, and lately radiosurgery.(ABSTRACT TRUNCATED AT 400 WORDS)