Complications of Spine Surgery in Elderly Japanese Patients: Implications for Future of World Population Aging

Objective: To analyze the relationship between age and perioperative complications of spine surgery in a Japanese cohort with the longest average life expectancy in the world. Methods: Patients with spinal stenosis who underwent standard spine surgery without instrumented fusion were divided into 4 groups: adults (20-64 years), the young-old (6574), the middle old (75-84), and the oldest-old (>= 85). Data on medical complications, surgical complications, and deaths within 30 days of index surgery were compared across the groups. Risk factors for complications were identified through multivariate analysis. Results: A total of 584 patients underwent 673 operations: 35% were performed on adult patients, 33% on the young-old, 27% on the middle old, and 5% on the oldest-old. The rates of total or [major] medical complications significantly increased with age (8% [0.8%], 11% [0.9%], 27% [3.9%], 45% [9.1%], respectively; p<0.001 [p=0.003]), whereas those of surgical complications did not differ (11%, 8.1%, 14%, 9.1%, respectively; p=0.25). Independent risk factors for medical complications were an age of 75 years or older (75-84: odds ratio [OR], 5.1; >= 85: OR, 6.2) and American Society of Anesthesiologists (ASA) physical status classification III (OR, 5.4). Two patients older than 85 years died from medical complications. Conclusion: The complications of spine surgery increased in the middle and oldest-old patients because of medical complications; however, most were minor and treatable. Major complications were associated with preoperative medical comorbidities and their severities; therefore, most elderly patients with low ASA physical status classification (<= II) may benefit from spine surgery.