To assess long-term APV and split-appendix MACE durability and to compare split and intact appendix APVs in a large patient cohort.

This retrospective cohort study included consecutive patients ≤21 years old undergoing an APV at our institution (1990-2019). Main outcomes were stomal and subfascial revisions. Kaplan Meier survival and Cox proportional hazards analysis were used.

A total of 339 patients underwent APV creation at a median 7.4 years old (41% female vs. 59% male; 37% umbilical stoma vs. 63% other). In total, 36 patients underwent a stomal revision and 19 a subfascial revision (median channel follow-up 6.3 years). On survival analysis, the risk of stomal revision of the APV was 9.1% at 5 years, 12.6% at 10 years and 16.5% at 15 years. Risk of subfascial revision of the APV was 5.1% at 5 years, 7.0% at 10 years and 8.2% at 15 years. A split-appendix APV was performed in 118 (34.8%) of 339 patients. They had a shorter follow-up compared to those with an intact APV (5.1 vs. 7.0 years, p=0.03). After correcting for differential follow-up time, there was no significant difference between groups for stomal revisions (HR 1.11, p=0.76) or subfascial revisions (HR 0.80, p=0.67, Figure). Risk of APV stomal revision was independent of stomal location and age at surgery (p>=0.37). Similarly, risk of subfascial APV revision was independent of stomal location and age at surgery (p>=0.18). Risk of stomal revision for split-appendix MACE channels was 16.2% at 5, 10 and 15 years (similar to split-appendix APV and all APVs, p>=0.26). Risk of MACE subfascial revision was 5.5% at 5 years, 5.5% at 10 years and 14.7% at 15 years (similar to split-appendix APV and all APVs, p>=0.36).

We focused on surgical complications, as these entail the highest morbidity, however, we did not assess non-surgical, percutaneous or endoscopic management which also impact long-term outcome and patient quality of life. We did not compare the outcomes of the split-appendix MACE to an intact-appendix MACE cohort, as this patient population was not captured in this review.

The split-appendix technique has durable long-term results for both the APV and MACE channels, which are comparable to the technique utilizing the intact appendix. Channel complications occur over the channel’s lifetime, as 1 in 8 APVs in the entire cohort underwent a stomal revision and 1 in 14 APVs underwent a subfascial revision at 10 years after surgery.