Defining proficiency in THD-Anolift: a CUSUM analysis of the learning curve in 51 consecutive cases

Transanal hemorrhoidal dearterialization (THD) with Anolift mucopexy is a validated non-excisional procedure for hemorrhoidal disease. Although surgeon experience is acknowledged as a determinant of THD outcomes, no formal learning curve analysis exists. This study aimed to characterize the learning curve of a single surgeon adopting THD-Anolift.

Retrospective analysis of 60 consecutive THD-Anolift cases (May 2023-February 2026). Nine patients with incomplete outcome data were excluded, leaving 51 for analysis. Median follow-up was 12 months (range 3-33). Cumulative sum (CUSUM) charts were constructed for a composite failure endpoint (recurrence and/or any complication) and for operative time. The proficiency point was identified at the CUSUM inflection. Sensitivity analyses included CUSUM on recurrence alone, CUSUM restricted to recurrence and Clavien-Dindo ≥ II complications, best-case/worst-case imputation for excluded patients, and risk-adjusted CUSUM controlling for hemorrhoid grade and previous procedures.

Median age was 53 years; 72.5% were male; 80.4% had grade III hemorrhoids. The overall composite failure rate was 37.3% (19/51) and the recurrence rate 15.7% (8/51). Mean operative time was 23.5 ± 7.4 min. The composite outcome CUSUM identified a proficiency point at case 23: the failure rate decreased from 52.2% in Phase 1 (cases 1-23) to 25.0% in Phase 2 (cases 24-51; p = 0.080, not statistically significant at the conventional threshold). Operative time decreased from 27.1 ± 7.4 to 20.4 ± 6.0 min (p < 0.001). On sensitivity analysis, both the recurrence-only CUSUM and the risk-adjusted CUSUM confirmed an identical proficiency point at case 23, and worst-case/best-case imputation for excluded patients moved the inflection only to cases 25 and 22 respectively, indicating that the finding was robust to endpoint definition and case-mix variation, as well as to plausible patterns of missing data.

CUSUM analysis identified an inflection at approximately 23 cases, with a statistically significant reduction in operative time and a clinically relevant but underpowered reduction in composite failure that did not reach the conventional threshold for statistical significance. Rather than a fixed competency threshold, these findings provide an initial benchmark to help structure supervised adoption-suggesting that the 10 mentored cases conventionally proposed in industry-sponsored teaching may be insufficient- and to inform future multicenter validation.