Assessment of Urostomy Parastomal Herniation Forces Using Incisional Prevention Strategies with an Abdominal Fascia Model

Diboro L Kanabolo; Adam D Maxwell; Yashwanth Nanda Kumar; George R Schade

doi:10.1016/j.euros.2023.05.019

Assessment of Urostomy Parastomal Herniation Forces Using Incisional Prevention Strategies with an Abdominal Fascia Model

Eur Urol Open Sci. 2023 Jun 21:54:66-71. doi: 10.1016/j.euros.2023.05.019. eCollection 2023 Aug.

Authors

Diboro L Kanabolo¹, Adam D Maxwell^{1

2}, Yashwanth Nanda Kumar², George R Schade¹

Affiliations

¹ Department of Urology, University of Washington Medical Center, Seattle, WA, USA.
² Center for Industrial and Medical Ultrasound, Applied Physics Laboratory, University of Washington, Seattle, WA, USA.

Abstract

Background: Approximately 10 000 patients undergo cystectomy/ileal conduit annually in the USA, of whom over 70% subsequently develop a parastomal hernia (PSH). Still, no well-established "best" practice for stoma creation to prevent a PSH exists.

Objective: To measure the relationship between incision size/type/material and axial tension force (ATF) as a surrogate for herniation force, using several models to mimic abdominal fascia.

Design setting and participants: Abdominal fascia models included silicone membrane, ex vivo porcine, and embalmed human cadaveric fascia. A dynamometer pulled a Foley catheter (20 mm/min) with the balloon inflated to 125% incision (linear, cruciate, and circular) diameter using a motorized positioning system. The maximum ATF before herniation was recorded. The study was repeated in unused silicone/tissue for suture reinforcement. We evaluated silicone, ex vivo porcine, and human abdominal fascia.

Intervention: Incision sizes (1-3 cm) in 0.5-cm increments were evaluated in silicone. A 3-cm incision was used in porcine/human tissue.

Outcome measurements and statistical analysis: ATF for herniation was recorded/compared across incision types/sizes using Mann-Whitney U and Kruskal-Wallis tests as appropriate, with α = 0.05.

Results and limitations: Linear incision ATF was significantly greater than cruciate and circular incisions. A cruciate incision had significantly greater ATF than a circular incision. In cadaveric tissue, incisions were significantly greater for linear (34.5 ± 12.8 N) versus cruciate (15.3 ± 2.9 N, p = 0.004) and for cruciate versus circular (p = 0.023) incisions. Results were similar in ex vivo porcine fascia and silicone. Reinforcement with a suture significantly increased ATF in all materials/incision sizes/types. The ex vivo nature is this study's main limitation.

Conclusions: This study suggests that urostomy fascial incision type may influence ATF required for herniation. Linear incisions may be preferable. Urostomy reinforcement may significantly increase ATF required for a PSH. These data may help establish best practices for PSH risk reduction.

Patient summary: The results of this study illustrate that urostomy fascia incision type may influence the force required to create a parastomal hernia. Linear incisions may be preferable.

Keywords: Bladder cancer; Ileal conduit; Incision; Parastomal hernia; Reconstruction; Urostomy.