Selective Management of Inguinal Canal Fat During TAPP Repair: Distinguishing True Lipoma from Preperitoneal Fat

Abstract

Background:

Inguinal canal fat encountered during inguinal hernia repair is frequently described as a lipoma, although many lesions are continuous with preperitoneal fat (PPF) rather than true neoplasms. The lack of clear intraoperative criteria has led to controversy regarding routine excision versus conservative management. This study aimed to determine whether intraoperative differentiation between true lipomas and PPF can guide selective surgical management.

Methods:

We retrospectively reviewed 2465 adult patients (aged ≥20 years) who underwent transabdominal preperitoneal (TAPP) repair between January 2019 and December 2023. Among them, 271 patients with fatty tissue in the inguinal canal were analyzed. Intraoperative fatty tissue was classified as either true lipoma or PPF based on encapsulation and continuity with the preperitoneal space. True lipomas were excised, and PPF was managed with reduction alone.

Results:

The presence of inguinal canal fat was not associated with differences in the demographic or hernia-related clinical characteristics. Recurrence was rare in both groups (0.3% versus 0.4%), with no significant difference between the patients with and without fatty tissue. Operative time was longer in patients with fatty tissue (35.6 ± 8.2 versus 28.9 ± 5.8 minutes, P < .001). Within the fat group, lipoma excision required longer operative time (41.8 ± 9.5 versus 34.9 ± 7.8 minutes, P = .001) and was associated with a higher complication rate (10.0% versus 1.2%, P = .005) than was PPF reduction, while recurrence and metachronous contralateral inguinal hernia were rare in both subgroups. Other postoperative outcomes were comparable between the strategies.

Conclusions:

Most fatty protrusions encountered in the inguinal canal during TAPP repair were continuous with the PPF layer rather than discrete encapsulated lipomas. In appropriately selected cases, reduction of PPF without excision appeared feasible and safe, with favorable short- and long-term outcomes.