Evaluating the Impact of Preoperative Hematological and Renal Parameters on Postoperative Outcomes in Patients with Adult Degenerative Scoliosis Undergoing Spinal Fusion

Introduction: Adult Degenerative Scoliosis (ADS) often necessitates spinal fusion due to its intricate nature. This study examines the correlation between preoperative factors such as INR, Platelet count (Plt), Hemoglobin (Hgb), Hematocrit (Hct), Creatinine (Cr), and Blood Urea Nitrogen (BUN), and postoperative outcomes including like Estimated Blood Loss (EBL), ICU and total Length of Stay (LOS), Postoperative Day (POD) initiation walking, anesthesia duration, and change in Oswestry Disability Index (deltaODI).

Methods: All ADS patients who underwent long segment thoracolumbar fusion for abnormal spinal curvature over a period of five years, from 2016 to 2020 were included. Overall, this yielded 235 patient records. A linear regression model assessed the relationships between preoperative factors and postoperative outcomes in patients with ADS undergoing spinal fusion. Normal threshold levels were defined as: Hgb at 12.4 g/dL, INR at 1.3, Hct at 34, Plt at 150 x 10^9/L, and Cr at 1.25 mg/dL.

Results: Our analysis of the ADS cohort revealed that elevated Preoperative INR significantly correlated with increased EBL (coefficient=504.80, CI=100.43–909.16, p=0.015). Preoperative Plt was inversely related to EBL (coefficient=-708.90, CI=-1247.02–-170.79, p=0.01) and anesthesia duration (coefficient=-41.59, CI=-81.54–-1.65, p=0.041), and significantly influenced POD initiation walking (coefficient=-2.34, CI=-3.85–-0.84, p=0.002). Preoperative Hgb and Hct levels were associated with decreased ICU LOS (Hgb coefficient=-17.99, CI=-33.74–-2.24, p=0.025; Hct coefficient=-30.86, CI=-56.85–-4.87, p=0.02). Additionally, normal Plt and Hgb levels, along with normal Hct, correlated with favorable outcomes like shorter total LOS (Plt coefficient=-3.30, CI=-5.08–-1.52, p< 0.001; Hgb coefficient=-1.13, CI=-2.17–-0.10, p=0.031) and earlier POD initiation walking. Abnormal preoperative BUN levels were associated with increased anesthesia duration (coefficient=33.36, CI=5.60–61.11, p=0.019) and deltaODI (coefficient=7.56, CI=0.40–14.72, p=0.039). Preoperative Cr showed a significant correlation with total LOS (coefficient=0.07, CI=0.01–0.14, p=0.031).

Conclusion : This study emphasizes the significance of preoperative factors in determining postoperative outcomes in ADS spinal surgeries. Elevated INR, abnormal BUN, and low levels of Plt, Hgb, and Hct were linked with various postoperative outcomes, highlighting the importance of optimizing these factors preoperatively to improve postoperative outcomes in ADS.