METHODS: Data were collected on 640 consecutively enrolled AVMs in a database that included all patients not considered for surgery.

RESULTS: Patients with Spetzler-Martin grade 1 to 2 AVMs (n = 296) were treated with a sur- gical risk of 0.7% (95% confidence interval [CI], 0%-3%); patients with Spetzler-Martin grade 3 to 4 AVMs in noneloquent cortex (n = 65) were treated with a surgical risk of 17% (95% CI, 10%-28%). Patients with Spetzler-Martin grade 3 to 5 AVMs in eloquent cortex (n = 168) were treated with a surgical risk of 21% (95% CI, 15%-28%). However, because 14% of patients in this series with similar AVMs were refused surgery because of perceived surgical risk, these results are not generalizable to the population of patients with similar AVMs.

CONCLUSION: The results of this series suggest that it is reasonable to offer surgery as a preferred treatment option for Spetzler-Martin grade 1 to 2 AVMs. This study also rein- forces the predictive value of the Spetzler-Martin grading system, with some caveats.

This article was published the the journal called Neurosurgery (click here to see detailed list of publications).

METHODS:We reviewed 640 patients operated on by Professor Morgan.

RESULTS: The low grade AVMs had a risk of a permanent disablity or death of less than 1%.  However, for more complex AVMs the risk is significantly higher than this.  The risk of surgery in higher grade brain AVMs will not be less than 10% and depending on the characteristics, may be inoperable because the risks are too great. 

CONCLUSION: The results of this series suggest that it is reasonable to offer surgery as a preferred treatment option for low grade AVMs. This study also reinforces the predictive value of the Spetzler-Martin grading system, with some caveats.  However, the Spetzler-Martin grade is not always accurately applied by doctors.

OBJECTIVE: To assess in depth the variables contributing to adverse surgical outcome for repair of unruptured middle cerebral artery aneurysms.

METHODS: Prospectively collected data between October 1989 and June 2009 were examined retrospectively. Putative risk factors were investigated with univariate and multivariate logistic regression analyses.

RESULTS: In this study, 263 patients (339 aneurysms) underwent surgical clipping in 280 operations for unruptured middle cerebral artery aneurysms. The overall surgical mortality and morbidity rate was 5% (95% confidence interval [CI], 2.9-8.3). Multivariate logistic analysis of risk factors revealed that age and aneurysm size were independent predictors of surgical outcome. Patients < 60 years of age with an aneurysm ≤ 12 mm constituted a low-risk group with a procedure-related combined mortality and morbidity of 0.6% (95% CI, 0-3.8). Patients < 60 years of age with an aneurysm > 12 mm had a procedure-related combined mortality and morbidity of 7.4% (95% CI, 1-24.5). Patients ≥ 60 years of age with an aneurysm of ≤ 12 mm had a procedure-related combined mortality and morbidity of 9.3% (95% CI, 4.3-18.3). Patients ≥ 60 years of age with an aneurysm > 12 mm had a procedure-related combined mortality and morbidity of 22.2% (95% CI, 8.5-45.8).

CONCLUSION: Age and size of aneurysm were the only 2 independent predictors of surgical outcome.

We retrospectively investigated preoperative variables contributing to adverse surgical outcome for repair of unruptured posterior circulation aneurysms on data collected prospectively between October 1989 and March 2010. Putative risk factors including age, sex, smoking status, positive family history, modified Rankin Score prior to the surgery, size of the aneurysm, specific site (basilar caput and trunk, vertebral artery and posterior inferior cerebellar artery), midline location, presence of calcium, thrombus or irregularity in the aneurysm on preoperative imaging, associated arteriovenous malformation and preoperative coiling were investigated using regression analyses. In a total of 121 operations, surgical mortality and morbidity was 16.3%. For patients with aneurysms less than 9 mm this rate was 3.2%. Among the investigated variables we found that size, calcification of the aneurysm and age were each predictors of surgical outcome of unruptured posterior circulation aneurysms.

Comparative patency between intracranial arterial pedicle and vein bypass surgery.

This article was published the the journal called Neurosurgery (click here to see detailed list of publications).

High flow bypass needs to be performed on occasions when large arteries leading to the brain need to be removed to treat tumours and aneurysms.  These high flow bypass connect the carotid artery in the neck to large arteries at the base of the brain with vein removed from the leg or radial artery from the arm.  This is similar to heart bypass surgery.  Low flow bypass use a scalp artery to supplement the flow of blood to the brain when there are blockages within the arteries at the skull base or at the base of the brain.  This is typically used in moyamoya disease or internal carotid/middle cerebral artery blockage where it is thought that stroke is imminent without treatment.  There is a difference in the risks for these two types of bypass.  This is not surprising given the difference in the magnitude of the surgery.  However, it is reassuring that beyond the first week, that both bypasses appear to last for many years.  There is a 99% long-term patency after this first week danger period.