The Impact of Endovascular Coiling versus Microsurgical Clipping on Short-Term Hospital Outcomes in Patients with Unruptured Cerebral Aneurysms

Background
Endovascular coiling and microsurgical clipping are two primary methods of intervention in unruptured cerebral aneurysms. Several studies have previously investigated the short-term in-hospital outcomes of patients with cerebral aneurysms from 1998-2007. This study aims to further examine the impact of endovascular coiling (EC) versus microsurgical clipping (MC) on short-term in-hospital outcomes among patients with cerebral aneurysms.

Methods
This retrospective cohort study utilized data from the Nationwide Inpatient Sample (NIS) to identify adult patients (18+) from 2012-2014 who had unruptured aneurysms that had also underwent EC or MC. ICD-9 codes identified these patients and were used to exclude patients who did not receive treatment. Patients missing important clinical identifiers (age, gender, death, race) were excluded. Hospital length of stay (LOS), total inpatient charges, inpatient mortality, and average age at admission were assessed.

Results
There were 25,433 encounters identified with a diagnosis of unruptured aneurysm. 8,350 patients underwent EC while 1,181 underwent MC. 15,902 of the 25, 433 encounters had no intervention (NI). Higher mortality was observed in patients who had undergone NI vs MC or EC (2.4% vs 1.6% , NI vs EC; 2.4% vs 0.9%, NI vs MC). Higher mortality was observed in patients who underwent EC (1.6%) vs MC (0.9%) (p = 0.000). Compared to the NI group, MC and EC had higher inpatient charges, with EC having the highest. ($51,003.07 vs $113,320.08 vs $122,882.36). Increased LOS was observed in the MC group vs the EC group. (6.09 vs 4.64 days). Compared to NI, the EC procedure has decreased LOS. (4.64 vs 5.09 days). Decreased age at admission was observed in MC and EC vs NI (56.07 vs 58.98 vs 66.52).

Conclusions
Patients with unruptured aneurysms that underwent EC and MC vs those with NI had lower mortality. Higher mortality was found in the EC group when comparing EC vs MC, however the NI group still had the highest. Both procedures had higher inpatient charges with EC having the highest overall charges. The EC procedure had the shortest length of stay vs NI and MC. The age of admission was decreased in both procedure groups vs NI. This data will assist physicians in making decisions regarding this population.