Paper of the Month for April looks at a trial comparing the parastomal hernia rates one year after the construction of an end colostomy by three surgical techniques: cruciate incision, circular incision in the fascia and using prophylactic mesh.

Methods of Colostomy Construction: No Effect on Parastomal Hernia Rate. Results from Stoma-const-A Randomized Controlled Trial

A Correa Martinez, D Bock, S Erestam, A Engström, P Kärlebo, Y Wirenfeldt Nielsen, J Rosenberg, E Haglind, E Angenete

Ann Surg 2021; Apr 1; 273(4):640-647. doi: 10.1097/SLA.0000000000003843

What is known about the subject?

Parastomal hernias are a significant complication after stoma formation. Reported parastomal hernia rates vary widely between 5 to 50 percent mainly due to heterogeneity of definition and method of diagnosis. Risk factors for parastomal hernia are age, diabetes, high body mass index and cancer diagnosis. A parastomal hernia may be defined as a 'protrusion in the abdominal wall in the proximity of the stoma'. Clinical assessment may be challenging, and computed tomography (CT), preferably carried out in prone position with Valsalva manoeuvre, increases the chances of accurate diagnosis. Parastomal hernias may cause emergency presentation due to obstruction or strangulation but most commonly impact on the patients' quality of life due to pain, skin irritation, leakage and issues with appliance fitting. In the literature, up to 75 percent of patients with parastomal hernias are suggested to be symptomatic.

What the study adds?

Parastomal hernia rates were investigated one year postoperatively after creation of an end colostomy, regardless of surgical indication, by three different surgical techniques: cruciate incision in the fascia, circular incision in the fascia or using prophylactic mesh (sub-lay lightweight partially absorbable). The study was a randomized, multicentre trial where patients were examined clinically and with CT abdomen in prone position 12 months postoperatively. Two hundred nine patients were randomized to one of the three arms and 185 patients were available for follow-up. Observed parastomal hernia rates at one year postoperatively were: 50.8 percent (cruciate incision), 37.5 percent (circular incision) and 39.7 percent (prophylactic mesh) with increased non-significant risk ratios between cruciate and circular (1.25, 0.83-1.88) and between cruciate and mesh (1.22, 0.81-1.84). Age and body mass index were related to development of a parastomal hernia.

Lack of systematic blinding, incomplete data concerning the primary endpoint in 10 percent of patients, early closure of the trial due to low dropout rate, and no validated radiological valuation were some study limitations. Furthermore, a longer follow-up time may have influenced the results.

Implications for colorectal practice

There is a burning need to establish the most favourable treatment for parastomal hernias, however prevention is optimal as explored in the present study. Moreover, the patient perspective is essential since parastomal hernias are ultimately very much a question about quality of life.

There is broad volatility in surgical practice regarding parastomal hernias including use of mesh for reinforcement purpose, the ideal mesh material, trephine shape and size, as assessed in the present study, and plane of placement. New techniques have been published in small series with promising results, but overall outcomes after both prophylactic measures and surgical repair remain discouraging. Additionally, issues with the definition and diagnosis of parastomal hernias also cause challenges when trying to assess whether an intervention or treatment for parastomal hernias has been successful. This study concludes that there is no clear advantage in using any of the tested surgical techniques. This is consistent with the STOMAMESH study, thus prophylactic mesh may not be the magic universal solution, although it is recommended as routine by the European Hernia Society.

ESCP has an ongoing trial, the PROPHER trial, recently highlighted at the Global Reach webinar, which examines which patients should undergo parastomal hernia repair and the best technique to use. The PROPHER trial includes both operative and non-operative interventions as well as patient reported outcomes.

Aside from encouraging our patients to strive toward a normal body mass index, as colorectal surgeons we are still unsure how to avoid parastomal hernias and what treatment to offer if hernias develop. For now, we need to carefully monitor our own outcomes and join studies on parastomal hernias to gather more knowledge on how to best guide and treat our patients.

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