Objective:

The American College of Surgeons (ACS) updated its guidelines on overlapping surgery in 2016. The objective was to examine differences in postoperative outcomes following overlapping cases either pre-ACS guideline revision or post-guideline revision, in a coarsened exact matching (CEM) sample.

Methods:

3,327 consecutive adult patients undergoing single-level, posterior lumbar fusion from 2013-2019 were retrospectively analyzed. Patients were separated into a pre-ACS guideline revision cohort (surgery before April 2016) or a post-guideline revision cohort (surgery after October 2016) for comparison. The primary outcomes were proportion of cases performed with any degree of overlap, and adverse events including 30-day and 90-day rates of readmission, reoperation, Emergency Department visit, morbidity, and mortality. Subsequently, CEM was employed among overlapping surgery patients only to assess the impact of the ACS guideline revision on overlapping outcomes, while controlling for attending surgeon and key patient characteristics known to affect surgical outcomes.

Results:

After the implementation of the ACS guidelines, fewer cases were performed with overlap (22.0% vs. 53.7%, p<0.001). Patients in the post-ACS guideline revision cohort experienced improved rates of readmission and reoperation within 30 and 90 days. However, when limited to overlapping cases only, no differences were observed in overlap outcomes pre- vs. post-ACS guideline revision. Similarly, when exact matched on risk-associated patient characteristics and attending surgeon, overlapping surgery patients pre- and post-ACS guideline revision experienced similar rates of 30- and 90-day outcomes.

Conclusion:

After the ACS guideline revision, no discernable impact was observed on postoperative outcomes following lumbar fusion cases performed with overlap.