P23. The influence of preoperative controlling nutritional status on the occurrence of major complications following surgery for degenerative cervical myelopathy: a propensity score matching analysis

Major postoperative complications result in poor surgical outcomes and increased medical costs. Preoperative malnutrition has recently been focused on as a risk factor for postoperative complications in general surgery. This study aimed to assess the relationship between preoperative nutritional status, diagnosed using the controlling nutritional status (CONUT) score, and the occurrence of postoperative major complications in degenerative cervical myelopathy (DCM) using propensity score matching (PSM) analysis. N/A We retrospectively investigated the medical records of 220 patients (144 men and 76 women) who underwent surgery for DCM at our institution between 2014 and 2019. Clinical baseline data on the following were collected: age, sex, body mass index (BMI), comorbidities (such as diabetes mellitus, hypertension, and coronary artery disease), ongoing treatment (such as anticoagulation therapy and antiplatelet therapy), preoperative hemoglobin level, and American Society of Anesthesiologists (ASA) physical status classification. The CONUT score was calculated based on laboratory examination findings on serum albumin level, total lymphocyte count, and total serum cholesterol level, thus establishing the preoperative nutritional condition. Laboratory examinations were performed within three months before surgery. Surgical factors, including operative time, surgical approach, and use of implants, were considered. Regarding clinical outcomes, the length of hospital stay (LOS), from the day of surgery to the day of discharge, and the occurrence of the following postoperative major complications within 30 days of surgery were investigated: unplanned intubation for ≥48 h, bleeding requiring transfusion of >4 U red blood cells within 72 h after surgery, coronary artery disease, acute renal failure, stroke or cerebral hemorrhage, sepsis, pneumonia, severe delirium, deep venous thrombosis, pulmonary embolism, and wound disruption. Patients were categorized into the malnutrition group (preoperative CONUT score, 2–11) and the normal nutrition group (preoperative CONUT score, 0–1). The occurrence of major complications and LOS were compared between the groups. Further, 1:1 propensity score matching (PSM) was used to adjust for clinicopathological differences. The chi-square and Fisher's exact tests were used for categorical variables, and the Mann–Whitney test was used for continuous variables. Among the 220 patients, 75 (34%) were in the malnutrition group, and 145 (66%) were in the normal nutrition group. The malnutrition group was older and had a lower BMI, poorer ASA physical status, and more comorbidities than the normal nutrition group before PSM. After 1:1 PSM (63 matched pairs), the malnutrition group had a higher postoperative major complication rate (odds ratio, 3.84; 95% confidence interval, 1.18–12.5; p<.05) and a longer LOS (24 vs 19 days; p<.01) than the normal nutrition group. The CONUT score, easily calculated from preoperative laboratory examination findings, can reflect the preoperative nutritional and inflammatory status. Therefore, the preoperative CONUT score can predict the occurrence of major complications and prolonged LOS after surgery in patients with DCM. Preoperative nutritional intervention may prevent major postoperative complications in patients with high CONUT scores. Thus, regular monitoring of the CONUT score before surgery for DCM has its advantages. This abstract does not discuss or include any applicable devices or drugs.