The impact of body mass index on early readmission and reoperation following endoscopic vs. open/microsurgical lumbar surgery: A nationwide analysis.

Publication/Presentation Date

6-26-2026

Abstract

OBJECTIVE: Lumbar degenerative spine disease (LDSD) often requires surgery when conservative treatments fail. Endoscopic lumbar discectomy (ELD) is a minimally invasive alternative to open discectomy, potentially improving recovery. While BMI influences surgical outcomes, its effect on early readmission and reoperation remains unclear. This study examines the relationship between BMI and 30-day postoperative outcomes in LDSD patients undergoing endoscopic versus open lumbar surgery.

METHODS: The ACS-NSQIP database (2017-2022) was analyzed to identify patients undergoing endoscopic (CPT 62380) or open/microsurgical (CPT 63030) lumbar decompression. BMI was categorized per WHO classifications. Primary outcomes were 30-day readmission and reoperation. Propensity score matching (1:1) on age group, sex, and functional status was performed, with standardized mean differences used to assess balance; logistic regression quantified BMI's association with early outcomes. Machine learning models, evaluated with internal cross-validation, identified candidate BMI thresholds for predicting complications.

RESULTS: Among 123,457 patients (mean BMI: 30.8 ± 6.5 kg/m²), obesity was common (41.4%). Open surgery accounted for 99.7% of cases (123,121 open vs. 336 endoscopic; 672 patients [336 per group] after 1:1 matching). Early reoperation and readmission rates were 2.5% and 4%, respectively. Endoscopic surgery was associated with younger patients, more outpatient procedures, and shorter hospital stays (0.9 ± 1.8 vs. 2 ± 2.5 days, p <  0.001). Severe obesity increased early readmission risk (OR: 1.25, p <  0.01), while underweight patients had the highest reoperation risk (OR: 1.55, p = 0.03). Machine learning identified candidate BMI thresholds for early readmission (open: 32.5 kg/m²; endoscopic: 39.5 kg/m²) and reoperation (open: 28.5 kg/m²; endoscopic: 29 kg/m²). Given the small endoscopic cohort (n = 336) and low event rates, all endoscopic findings, including endoscopic-specific thresholds, should be regarded as exploratory and hypothesis-generating rather than confirmatory.

CONCLUSION: BMI and surgical approach are associated with early surgical outcomes. In the matched cohort, the endoscopic group, which comprised younger, healthier, and more frequently ambulatory patients, was associated with shorter hospital stays and higher home discharge rates; however, because endoscopic cases represented only 0.3% of the cohort and residual confounding by indication is likely, these comparative observations should be interpreted with caution. Severely obese patients faced higher readmission risks, and underweight patients undergoing open surgery had the highest reoperation rates. Candidate BMI thresholds for risk stratification were identified, but require prospective external validation before they can inform individualized surgical planning.

Volume

269

First Page

109553

Last Page

109553

ISSN

1872-6968

Disciplines

Medicine and Health Sciences

PubMedID

42419172

Department(s)

Medical Education

Document Type

Article

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