Comparison of postoperative complications and outcomes following primary versus revision discectomy: A national database analysis

Background: Lumbar microdiscectomy is a surgical procedure that is frequently used in the treatment of symptomatic lumbar herniation. Differences in outcomes following primary and revision lumbar microdiscectomy have been previously studied, with reports of comparably satisfactory results from the Spine Patient Outcomes Research Trial. In this study, we further investigate these outcomes, including length of stay, bleeding events, and durotomy. We hypothesized that length of stay, incidence of bleeding events, and dural tear would be greater in the revision cohort.

Methods: The ACS-National Surgical Quality Improvement Program database was queried for patients undergoing single-level primary and revision lumbar microdiscectomy between 2019 and 2022. Eligibility for inclusion was determined by age >18 years and current procedural terminology codes 63030 and 63042. Patients with preoperative sepsis or cancer were excluded. Length of stay, wound infection, bleeding events requiring transfusion, cerebrospinal fluid leak, dural tear, and neurological injury were compared between the cohorts. Multivariable Poisson regression adjusted for demographics and comorbidities, including age, sex, race, body mass index, diabetes, smoking, and hypertension, was used to determine if revision was predictive of complications.

Results: A total of 37,669 patients were included, of whom 3,635 (9.6%) required revision surgery. Patients in the revision cohort were older (54.25 ± 15.7 vs. 50.85 ± 16.0 years, P < 0.001) and had higher proportions of male (59.0% vs. 55.7%, P < 0.001) and non-Hispanic White patients (82.0% vs. 77.4%, P < 0.001). Length of stay (1.11 ± 2.5 vs. 1.58 ± 2.7, P < 0.001) and rates of wound infection (2.1% vs. 1.4%, P = 0.002) and bleeding events requiring transfusion (1.3% vs. 0.7%, P < 0.001) were greater in the revision cohort compared to primary patients. Differences in cerebrospinal fluid leak (0.2% vs. 0.1%, P = 0.116), dural tear complication (0.01% vs. 0.01%, P = 0.092), and neurological injury (0.008% vs. 0.006%, P = 0.691) between the revision and primary cohorts were nonsignificant. Poisson log-linear regression adjusted for demographics and comorbidities demonstrated revision as a significant predictor for length of stay (χ ² = 462.95, P < 0.001), wound infection (χ ² = 9.22, P = 0.002), and bleeding events (χ ² = 9.74, P = 0.002), while it was a nonsignificant predictor of cerebrospinal fluid leak (χ ² = 2.61, P = 0.106), dural tear (χ ² = 2.37, P = 0.123), and neurological injury (χ ² = 0.229, P = 0.632).

Conclusion: Revision surgery was a significant predictor of increased length of stay, wound infection, and bleeding events requiring transfusion. Surgeons and patients alike should be aware of increased risk for complications following revision lumbar microdiscectomy compared to primary discectomy.