(IP213) Cumulative Risks for Reoperation Due to Bleeding After Carotid Endarterectomy and The Associated Clinical Impact of Bleeding Events

Objectives: The purpose of this study is to identify all preoperative and intraoperative variables in the VQI CEA module that have a statistically significant association with reoperation for bleeding after CEA. A cumulative risk score for reoperation for bleeding will be developed. The impact of reoperation for bleeding on 30-day mortality and adverse perioperative events will be quantified.

Methods: The VQI CEA module was queried between 2003 and 2023 and 192,547 met study inclusion. An internal VQI validation cohort was created utilizing CEA performed in 2024 and 17,449 met inclusion. The primary study outcome was return to the operating room for bleeding after CEA. Univariable analysis was conducted followed by binary logistic regression analysis utilizing significant univariable factors. Regression beta-coefficient was used to create a weighted risk score for bleeding related reoperation and internal validation with testing at each risk score was conducted. Frequency of major adverse perioperative events for those who did and did not experience bleeding complication was analyzed.

Results: Variables which had a statistically significant multivariable association (P <.05) with reoperation for bleeding after CEA are displayed in Figure 1 with their respective weight values in the risk score. Patients with risk scores of zero or less had an only .006% risk of return to the operating room for bleeding. There was significant elevation in risk for return to the operating room for bleeding with escalating risk sores. Patients with risk scores 11 and higher had an absolute reoperation for bleeding event rate of 3.6%, or a total event rate 600 times higher than individuals with scores of 0 or less and 3.6 times as high as individuals with scores as high as 5. The internal VQI validation cohort experienced the event of return to the operating room for bleeding at very similar rates to the primary study source cohort with no statistically significant difference at any of the risk score points indicating quality accuracy for the risk score (Figure 1). Figure 2 displays the increased adverse event rates associated with reoperation for bleeding.

Conclusions: A quantitative risk score for reoperation for bleeding after carotid endarterectomy has been developed which has quality internal validation. The most impactful modifiable variables are intraoperative protamine utilization and avoidance of dual antiplatelet therapy. Reoperation for bleeding was associated with higher rates of 30 day mortality, MI, CHF, cranial nerve injury, SSI, cardiac dysrhythmia and perioperative neurological event.