Liver disease is an independent predictor of poor 30-day outcomes following surgery for degenerative disease of the cervical spine

Background and context: The impact of underlying liver disease on surgical outcomes has been recognized in a wide variety of surgical disciplines. However, less empiric data are available about the importance of liver disease in spinal surgery.

Purpose: To measure the independent impact of underlying liver disease on 30-day outcomes following surgery for the degenerative cervical spine.

Study design: Retrospective comparative study.

Patient sample: A cohort of 21,207 patients undergoing elective surgery for degenerative disease of the cervical spine from the American College of Surgeons National Surgical Quality Improvement Program.

Outcome measures: Outcome measures included mortality, hospital length of stay, and postoperative complications within 30 days of surgery.

Methods: The NSQIP dataset was queried for patients undergoing surgery for degenerative disease of the cervical spine from 2006 to 2015. Assessment of underlying liver disease was based on aspartate aminotransferase-to-platelet ratio index and Model of End-Stage Liver Disease-Sodium scores, computed from preoperative laboratory data. The effect of liver disease on outcomes was assessed by bivariate and multivariate analyses, in comparison with 16 other preoperative and operative factors.

Results: Liver disease could be assessed in 21,207 patients based on preoperative laboratory values. Mild liver disease was identified in 2.2% of patients, and advanced liver disease was identified in 1.6% of patients. The 30-day mortality rates were 1.7% and 5.1% in mild and advanced liver diseases, respectively, compared with 0.6% in patients with healthy livers. The 30-day complication rates were 11.8% and 31.5% in these patients, respectively, compared with 8.8% in patients with healthy livers. In multivariate analysis, the presence of any liver disease (mild or advanced) was independently associated with an increased risk of mortality (OR=2.00, 95% CI=1.12-3.55, p=.019), morbidity (OR=1.35, 95% CI=1.07-1.70, p=.012), and length of hospital stay longer than 7 days (OR=1.73, 95% CI=1.40-2.13, p<.001), when compared with 18 other preoperative and operative factors. Liver disease was also independently associated with perioperative respiratory failure (OR=1.80, 95% CI=1.21-2.68, p=.004), bleeding requiring transfusion (OR=1.43, 95% CI=1.01-2.02, p=.044), wound disruption (OR=2.82, 95% CI=1.04-7.66, p=.042), and unplanned reoperation (OR=1.49, 95% CI=1.05-2.11, p=.025).

Conclusions: Liver disease independently predicts poor perioperative outcome following surgery for degenerative disease of the cervical spine. Based on these findings, careful consideration of a patient's underlying liver function before surgery may prove valuable in surgical decision-making, preoperative patient counseling, and postoperative patient care.