The impact of the international subarachnoid aneurysm trial (ISAT) on the management of aneurysmal subarachnoid haemorrhage in a neurosurgical unit in the UK

OBJECTIVE To review the changes in the management of aneurysmal subarachnoid haemorrhage (SAH) in a single neurosurgical unit in the UK, following the publication of the international subarachnoid aneurysm trial (ISAT). METHODS The presentation, investigations, treatments and outcome data of all patients admitted with SAH to the neurosurgical unit between February 2001 and May 2003 were prospectively recorded in a database. The total period studied was split in to three blocks, around the time of publication of the ISAT in October 2002 (period 1=February-December, 2001; period 2=January-September, 2002 and period 3=October 2002 to May 2003). RESULTS Of the 177 patients admitted with presumed SAH, 130 patients with evidence of an aneurysm on angiograms were included in the study. The mean age was 53+/-1 years, 92 (71%) patients were WFNS grade 1 or 2 and 77 (60%) were Fischer grade 2 or 3. These parameters were unchanged over the study period. Overall, 60 patients (46%) underwent a craniotomy for clipping or wrapping of aneurysm, 60 (46%) underwent endovascular embolisation of the aneurysm and 10 patients (8%) were managed conservatively. Over the study periods 1-3, the proportion of patients undergoing open surgery decreased (from 51 to 31%) while endovascular treatment of aneurysms increased (35-68%; p<0.01). Over the same time points there was a non-significant trend towards better Glasgow outcome scores at 6 months follow-up. The management mortality for all WFNS grades of patients with SAH was eight deaths (14%). The mortality in the surgical group was 3 patients (5%) and there were no deaths in the endovascular group. Over the study periods 1-3, there was a decrease in the mean total duration of hospital stay (from 23.6 to 15.5 days; p<0.05) in WFNS grade 1 and 2 patients and this was related to a shorter duration of hospital stay in the endovascular than surgical group of patients (p<0.05). The mean delay in obtaining an angiogram increased over the study periods 1-3 (1.1-2.3 days; p<0.05). CONCLUSIONS This observational study highlights the changing pattern of management of SAH and the potential difficulties that could be encountered. The proportion of patients undergoing endovascular treatment of aneurysms has increased following the publication of the ISAT study. The associated increase in the delay in obtaining an angiogram may reflect the increased workload encountered by the neuroradiologists.