Asymptomatic Preoperative Leukocytosis Before Carotid Endarterectomy is Associated With Increased Risk of Stroke: A Study From NSQIP Database

Abstract

Carotid endarterectomy (CEA) is the gold standard operation for treating carotid artery stenosis in patients with symptomatic carotid stenosis of more than 50% and asymptomatic carotid stenosis of more than 80%. Asymptomatic leukocytosis before CEA represents a clinical dilemma for surgeons about the management options. The objectives of this study are to identify the relationship between asymptomatic preoperative leukocytosis and postoperative complications in patients undergoing CEA and to assess the relationship between asymptomatic preoperative leukocytosis and postoperative complications in the cohort of patients with symptomatic carotid stenosis. The American College of Surgeons National Surgical Quality Improvement Program database for the years 2011-2019 was utilized for this analysis. Patients with preoperative sepsis, septic shock, pneumonia, wound infections, disseminated cancer, renal failure, and history of chronic steroid use were excluded. The remaining patients were sub-grouped based on white blood cell (WBC) count: Normal WBC (<11k/µL) and High WBC (≥11k/µL). Bivariate analysis between the patient characteristics and preoperative WBC levels was performed following simple and multiple regression analysis. A P-value of <0.05 was set as significant. Of the 26,332 patients in the study cohort, 7.4% (n =1,946) had preoperative leukocytosis. Patients with preoperative leukocytosis were relatively younger (mean age: 41.5 +/- 9.7 vs 44.3 +/- 9.1; P< 0.001) and more likely to be females (43% vs. 38.5; P< 0.001) than patients with normal WBC count. Patients with preoperative leukocytosis were also more likely to have DM, COPD, a bleeding disorder, be smokers, and be functionally dependent. The analysis revealed that patients with preoperative leukocytosis had a significantly higher rate of stroke, length of stay (LOS)>1- week, acute occlusion or revision, acute renal failure, and return to OR when compared to patients with normal WBC count. Furthermore, patients with high WBC count also experienced higher occurrences of infectious complications, such as wound dehiscence, wound infections, pneumonia, and sepsis. However, there was no difference in the overall 30-day mortality. Multivariate regression analysis showed patients with preoperative leukocytosis had anincreased risk of stroke (AOR 1.5, CI: 1.1-1.9, P = 0.009), LOS>1 week (AOR 1.3, CI: 1.1-1.5, P = 0.003), and return to OR (AOR 1.3, CI: 1.0-1.8, P = 0.030). The increased LOS was especially more pronounced in symptomatic carotid stenosis patients with preoperative leukocytosis. The occurrence of LOS>1 week was 4.91% in asymptomatic stenosis patients with high WBC count compared to 21.5% in symptomatic stenosis patients with high WBC count (P< 0.001). Patients with asymptomatic preoperative leukocytosis undergoing CEA have a significantly higher risk of stroke and infectious complications in the postoperative period. Furthermore, patients with symptomatic carotid disease are especially at an increased risk of prolonged LOS. A routine preoperative hematological evaluation may be recommended as a risk assessment tool for patients undergoing CEA, and postponing the elective operation in patients with asymptomatic CEA may be advised unless a thorough preoperative infectious workup is completed.