Search Results

You are looking at 1 - 10 of 71 items for

  • Author or Editor: Cameron McDougall x
Clear All Modify Search
Free access

Bradley A. Gross, Felipe C. Albuquerque, Karam Moon and Cameron G. McDougall


Many small series and technical reports chronicle the evolution of endovascular techniques for cranial dural arteriovenous fistulas (dAVFs) over the past 3 decades, but reports of large patient series are lacking. The authors provide a thorough analysis of clinical and angiographic outcomes across a large patient cohort.


The authors reviewed their endovascular database from January 1996 to September 2015 to identify patients harboring cranial dAVFs who were treated initially with endovascular approaches. They extracted demographic, presentation, angiographic, detailed treatment, and long-term follow-up data, and they evaluated natural history, initial angiographic occlusion, complications, recurrence, and symptomatic resolution rates.


Across a cohort of 251 patients with 260 distinct dAVFs, the overall initial angiographic occlusion rate was 70%; recurrence or occult residual lesions were seen on subsequent angiography in 3% of cases. The overall complication rate was 8%, with permanent neurological complications occurring in 3% of cases. Among 102 patients with dAVFs without cortical venous reflux, rates of resolution/improvement of pulsatile tinnitus and ocular symptoms were 79% and 78%, respectively. Following the introduction of Onyx during the latter half of the study period, the number of treated dAVFs doubled; the initial angiographic occlusion rate increased significantly from 60% before the use of Onyx to 76% after (p = 0.01). In addition, during the latter period compared with the pre-Onyx period, the rate of dAVFs obliterated via a transarterial-only approach was significantly greater (43% vs 23%, p = 0.002), as was the number of dAVFs obliterated via a single arterial pedicle (29% vs 11%, p = 0.002).


Overall, in the Onyx era, the rate of initial angiographic occlusion was approximately 80%, as was the rate of meaningful clinical improvement in tinnitus and/or ocular symptoms after initial endovascular treatment of cranial dAVFs.

Full access

Adib A. Abla, Cameron M. McDougall, Jonathan D. Breshears and Michael T. Lawton


Intracranial-to-intracranial (IC-IC) bypasses are alternatives to traditional extracranial-to-intracranial (EC-IC) bypasses to reanastomose parent arteries, reimplant efferent branches, revascularize branches with in situ donor arteries, and reconstruct bifurcations with interposition grafts that are entirely intracranial. These bypasses represent an evolution in bypass surgery from using scalp arteries and remote donor sites toward a more local and reconstructive approach. IC-IC bypass can be utilized preferentially when revascularization is needed in the management of complex aneurysms. Experiences using IC-IC bypass, as applied to posterior inferior cerebellar artery (PICA) aneurysms in 35 patients, were reviewed.


Patients with PICA aneurysms and vertebral artery (VA) aneurysms involving the PICA’s origin were identified from a prospectively maintained database of the Vascular Neurosurgery Service, and patients who underwent bypass procedures for PICA revascularization were included.


During a 17-year period in which 129 PICA aneurysms in 125 patients were treated microsurgically, 35 IC-IC bypasses were performed as part of PICA aneurysm management, including in situ p3-p3 PICA-PICA bypass in 11 patients (31%), PICA reimplantation in 9 patients (26%), reanastomosis in 14 patients (40%), and 1 V3 VA-to-PICA bypass with an interposition graft (3%). All aneurysms were completely or nearly completely obliterated, 94% of bypasses were patent, 77% of patients were improved or unchanged after treatment, and good outcomes (modified Rankin Scale ≤ 2) were observed in 76% of patients. Two patients died expectantly. Ischemic complications were limited to 2 patients in whom the bypasses occluded, and permanent lower cranial nerve morbidity was limited to 3 patients and did not compromise independent function in any of the patients.


PICA aneurysms receive the application of IC-IC bypass better than any other aneurysm, with nearly one-quarter of all PICA aneurysms treated microsurgically at our center requiring bypass without a single EC-IC bypass. The selection of PICA bypass is almost algorithmic: trapped aneurysms at the PICA origin or p1 segment are revascularized with a PICA-PICA bypass, with PICA reimplantation as an alternative; trapped p2 segment aneurysms are reanastomosed, bypassed in situ, or reimplanted; distal p3 segment aneurysms are reanastomosed or revascularized with a PICA-PICA bypass; and aneurysms of the p4 segment that are too distal for PICA-PICA bypass are reanastomosed. Interposition grafts are reserved for when these 3 primary options are unsuitable. A constructive approach that preserves the PICA with direct clipping or replaces flow with a bypass when sacrificed should remain an alternative to deconstructive PICA occlusion and endovascular coiling when complete aneurysm occlusion is unlikely.

Full access

Ruth E. Bristol, Felipe C. Albuquerque and Cameron G. McDougall

✓ Endovascular therapy for arteriovenous malformations (AVMs) remains a relatively new approach. Beginning in the 1960s with the use of flow-directed techniques for selective embolization, hemodynamic alterations have been used to treat these lesions. In every aspect of treatment, technological advances, including catheters, embolic materials, angiography suites, and pharmacological agents, have improved outcomes while lowering the risk to patients.

In this article, the authors review the technical evolution of endovascular AVM therapy. Developments in embolic materials, beginning with foreign bodies and autografts and continuing through to highly engineered contemporary substances, are discussed. Finally, changes in treatment paradigms that have occurred over the years are traced. Within neurosurgery, this specialty has shown some of the fastest growth and development in recent decades. As minimally invasive approaches are embraced in all areas of medicine, it is clear that this treatment modality will continue to be refined.

Restricted access


The Barrow Ruptured Aneurysm Trial

Giuseppe Lanzino

Restricted access

Wouter I. Schievink, A. Giancarlo Vishteh, Cameron G. McDougall and Robert F. Spetzler

Object. The use of intraoperative angiography of the spine has become available to neurosurgeons as an adjunct in the management of complex spinal vascular malformations. These vascular malformations are rare, and the use of intraoperative angiography of the spine has not been well described. The authors report their recent experience with the use of this diagnostic modality.

Methods. Between 1995 and 1997, nine consecutive patients with type II or Type IV spinal arteriovenous malformations (AVMs) underwent intraoperative spinal angiography. The cervical spine was involved in three patients, the thoracic spine in five, and the thoracolumbar junction in one. In three patients, intraoperative spinal angiography revealed an unexpected finding (residual filling of the AVM). The results obtained using postoperative spinal angiography in all patients showed complete agreement with the intraoperative studies. No complications arose from obtaining the intraoperative spinal angiograms.

Conclusions. Intraoperative spinal angiography is technically feasible, can be performed safely, and has adequate resolution. It detects unexpected residual AVM in one-third of cases.

Free access

Tim E. Darsaut and Jean Raymond

Full access

Louis J. Kim, Felipe C. Albuquerque, Cameron McDougall and Robert F. Spetzler

Recurrent aneurysms of the anterior circulation that are distal to the anterior communicating artery (ACoA) but proximal to the callosomarginal–pericallosal bifurcation can pose a treatment challenge. The authors present one such case, in which the patient was treated with pericallosal artery–pericallosal artery (PerA–PerA) side-to-side bypass, followed by endovascular obliteration of the proximal A2 parent vessel. This patient, in whom an ACoA aneurysm had been treated with clip ligation 5 years previously, presented with a new, mid-A2, right-sided aneurysm with the out-flow artery arising from the dome of the lesion.

The treatment plan included two steps: an interhemispheric transcallosal approach for PerA–PerA side-to-side anastomosis; and endovascular coil embolization of the right A2 branch feeding the aneurysm. Postprocedure angiography demonstrated no ipsilateral aneurysm filling and excellent bilateral distal outflow from the anterior cerebral artery (ACA).

The use of PerA–PerA side-to-side bypass for the treatment of an ACA aneurysm, followed by parent vessel occlusion, offers an elegant solution for the treatment of A2 aneurysms that are not amenable to stand-alone clip ligation or coil occlusion. Such combined methods are invaluable in the management of complex cerebral aneurysms.