Introduction: Subarachnoid hemorrhage(SAH)associated with cervical arteries dissection(CAD)is believed to be uncommon.In one case series, it was reported that up to 0.3% of all cases of SAH were attributable to a dissecting aneurysm of the internal carotid artery.Currently no large epidemiological study has addressed the incidence of CAD associated with SAH.In this study we sought to determine the incidence and risk factors for CAD in SAH.

Methods: The National Inpatient Sample(NIS)was queried for ICD-9 codes for SAH, from 2003 to 2008. Patients with CAD were selected between those who had SAH.

Results: During 6 year period the NIS recorded 13,227 SAH cases (6131 coiled and 7023 clipped aneurysms), whom 73 cases were associated with dissection.CAD was significantly more common in coil comparing to clip [(56 coiled and 17 clipped (P-value =0.004)].In those who coiled, the dissection were significantly more in vertebral artery, and in those who clipped the dissection was more common in carotid artery( P value=0.004).Linear regression analysis found that the number of SAH patients who developed CAD and specially rate of dissection in coiling increased over time, with the total number of CAD increasing from 0.123% to 0.287% and from 0.67% to 1.35% for coiling. Risk of CAD was lower in older patients(OR0.97;95%CI,0.96-0.99, p=0.023),blacks (OR0.119;95%CI,0.016-0.875,P=0.036),medium size hospitals(OR 0.15; 95% CI,0.027-0.857,P=0.032).CAD was significantly more common in coil compare to clip(OR 3.53;95% CI,1.79- 7.04,P=0.0002).In-hospital mortality didn’t change by CAD.In-hospital mortality was increasing with craniotomy(OR 2.24;95%CI,1.83-2.74,P=0.0000),coil(OR1.22;95%CI,1.10- 1.35,P=0.0001),hypertension(OR1.117;95%CI,1.00-1.24, P=0.036)and age(OR1.029;95% CI,1.025- 1.033,P=0.0000).

Conclusions: Our study demonstrates that the incidence of CAD in SAH patients is increasing in the United States. The risk of CAD was higher in coiling and less in older patients, blacks, and in those in medium size hospitals. Although CAD doesn’t change the rate of mortality in SAH, overall CAD related mortality, in SAH increases with craniotomy, coiling, HTN and age.

Patient Care: Knowing that the CAD happens more during coiling in SAH management, could aware the neuro-interventionist to prevent iatrogenic dissections.

Learning Objectives: THe rate of CAD in SAH is increasing during past several years and is specially associated with coiling in SAH.

References: Smith GA et al;Geographic variation and regional trends in adoption of endovascular techniques for cerebral aneurysms. J of Neurosurg,2011 Feb 11