A proposed classification of incisional hernias after kidney transplantation

Incisional hernia (IH) following kidney transplantation is underdiagnosed, with reported incidence rates of 1-7%. This study aimed to evaluate IH prevalence using computed tomography (CT), propose a novel classification system correlated with symptomatology, and evaluate its effect on interobserver IH detection rates.

A retrospective review of adults undergoing kidney-alone transplantation (2010-2017) at two Swedish centres was conducted. Patients with previous ipsilateral transplantation or poor-quality CT were excluded. Abdominal CT scans obtained ≥ 30 days postoperatively were reviewed by a multidisciplinary team (radiologist, transplant surgeon, and hernia specialist, all with > 20 years of experience), blinded to clinical data. Four subtypes of IHs after kidney transplantation were identified: 1A (normal contour, incomplete hernia), 1B (normal contour, complete hernia), 2A (abnormal contour, incomplete hernia), and 2B (abnormal contour, complete hernia). Symptomatology was assessed via medical records. Four external radiologists evaluated the classification's impact on detection rates.

Of 673 participants, 361 (54%) had evaluable CT scans. IHs were detected in 243 (68%), of which 36% were symptomatic. The proposed classification improved detection rates from 54% to 76% (p = 0.03) after an educational intervention. Symptom prevalence increased with hernia severity: 11% in type 1A, 13% in type 1B, 36% in type 2A, and 86% in type 2B (p < 0.01). Only 55% of symptomatic participants referred for IH mapping were correctly diagnosed prior to study reassessment.

IHs are prevalent and underdiagnosed after kidney transplantation. The proposed classification improves diagnostic accuracy, correlates with symptomatology, and facilitates clinical management and research.

Question The lack of a generally accepted definition of lateral abdominal wall defects (IH) results in a low detection rate after kidney transplantation. Findings The low detection rate of lateral abdominal wall defects (IH) improved significantly after self-study of the new classification system presented here. Clinical relevance Accurate detection of lateral abdominal wall defects will facilitate surgical repair and improvement of surgical suture techniques.