Mechanical Thrombectomy Performed at High Volume Institutions Results in Better Patient Outcomes

Introduction: Mortality, patient outcomes, procedural efficacy, morbidity, and complications have all been shown to be better in patient undergoing mechanical thrombectomy (MT) at high-volume centers. The benefit of reduced mortality rate is maintained even for patient transferred to high-volume centers. This study examines the relationship between patient outcomes and MT volumes using the NIS national sample.

Methods: Data were obtained from the National Inpatient Sample (NIS) maintained by the Agency for Healthcare Research and Quality (AHRQ). The annual volumes of MT were calculated during the 2017- 2020 using the International Classification of Diseases, 10th revision and clinical modification codes (ICD-10 CM).

Results: There were 20,715 MT cases identified in the NIS during 2017-2020, which corresponds to a national estimate of 103,575 total cases during this timeframe. Case volumes increased every year from 2017 to 2020. Institutions performing less than 105 MT annually had a significantly greater rate of mortality (OR (95% CI); 1.132 (1.012, 1.267), corresponding to a 13% increase in likelihood of death, p=0.030) after controlling for age, race, bed size, region, and teaching hospital status. Mean mortality rate for MT was 11.91% (SE 0.03%) for institutions performing greater than 105 MT annually, and 13.25% (SE 0.03%) for those performing less than 105.

Conclusion : All major randomized controlled MT trials, which demonstrate benefit for MT over medical management, were conducted at high-volume stroke centers. This study continues to show that optimal results are generalizable to high-volume stroke centers. Expanding MT capabilities to lower-volume hospitals must be weighed against patient outcomes and may not be warranted where high-volume comprehensive stroke centers are readily accessible.