Treatment of ruptured intracranial aneurysms: Report from a low-volume center

Caseload as a factor for outcome in aneurysmal subarachnoid hemorrhage: a systematic review and meta-analysis

Object

Increasing evidence exists that treatment of complex medical conditions in high-volume centers is found to improve outcome. Patients with subarachnoid hemorrhage (SAH), a complex disease, probably also benefit from treatment at a high-volume center. The authors aimed to determine, based on published literature, whether a higher hospital caseload is associated with improved outcomes of patients undergoing treatment after aneurysmal subarachnoid hemorrhage.

Methods

The authors identified studies from MEDLINE, Embase, and the Cochrane Library up to September 28, 2012, that evaluated outcome in high-volume versus low-volume centers in patients with SAH who were treated by either clipping or endovascular coiling. No language restrictions were set. The compared outcome measure was in-hospital mortality. Mortality in studies was pooled in a random effects meta-analysis. Study quality was reported according to the GRADE (Grading of Recommendations Assessment, Development and Evaluation) criteria.

Results

Four articles were included in this analysis, representing 36,600 patients. The quality of studies was graded low in 3 and very low in 1. Meta-analysis using a random effects model showed a decrease in hospital mortality (OR 0.77 [95% CI 0.60–0.97]; p = 0.00; I2 = 91%) in high-volume hospitals treating SAH patients. Sensitivity analysis revealed the relative weight of the 1 low-quality study. Removal of the study with very low quality increased the effect size of the meta-analysis to an OR of 0.68 (95% CI 0.56–0.84; p = 0.00; I2 = 86%). The definition of hospital volume differed among studies. Cutoffs and dichotomizations were used as well as division in quartiles. In 1 study, low volume was defined as 9 or fewer patients yearly, whereas in another it was defined as fewer than 30 patients yearly. Similarly, 1 study defined high volume as more than 20 patients annually, and another defined it as more than 50 patients a year. For comparability between studies, recalculation was done with dichotomized data if available. Cross et al., 2003 (low volume ≤ 18, high volume ≥ 19) and Johnston, 2000 (low volume ≤ 31, high volume ≥ 32) provided core data for recalculation. The overall results of this analysis revealed an OR of 0.85 (95% CI 0.72–0.99; p = 0.00; I2 = 87%).

Conclusions

Despite the shortcomings of this study, the mortality rate was lower in hospitals with a larger caseload. Limitations of the meta-analysis are the not uniform cutoff values and uncertainty about case mix.

Can a “novice” do aneurysm surgery? Surgical outcomes in a low-volume, non-subspecialised neurosurgical unit

The objective of this paper is to review the results of a junior general neurosurgeon performing aneurysm surgery and compare these to the remainder of his low-volume unit. Prospectively collected data was analysed for 114 aneurysms clipped in 99 patients between July 2001 and May 2005. Overall there was a 0.9% mortality rate and 10.8% complication rate. The favourable outcome rate for the unit was 100% for unruptured aneurysms, 90.4% for grades 1-3 patients and 30% for poor grade patients (grades 4 and 5). The novice neurosurgeon had no mortality and a favourable outcome rate of 94.7% for grades 1-3 patients and 50% for poor grade patients. Acceptable results can be obtained with cerebral aneurysm surgery in a low-volume centre by Australian-trained, non-subspecialty neurosurgeons.