Towards a standardised classification system for giant inguinal hernia

INTRODUCTION

Whereas groin hernias can be found worldwide, the giant inguinal hernia (GIH) is more prevalent in developing countries, especially in sub-Saharan Africa.^[1] This is due to a delay in presentation among patients who have groin hernias due to a combination of financial constraints^[2,3] and cultural factors^[4,5] leading to complex complications and challenging outcomes. In addition, <50% of individuals with groin hernias are promptly operated upon in sub-Saharan Africa.^[6]

Given the higher complication rates of GIH compared to other groin hernias^[7], there is a need for careful preoperative risk stratification in patients with GIH to ensure an improvement in the outcomes of treatment. Risk stratification for GIH is highly dependent on an appropriate classification system. However, hernia specialists do not have a consensus on the best classification for both scrotal and GIHs, which are a spectrum of groin hernias, as the GIH will result from neglected, longstanding scrotal hernias, which have been progressively increasing in size.

There is a pressing need to systematically evaluate the existing classification systems for GIH and determine their limitations in clinical practice. A robust classification system should facilitate risk stratification, guide surgical planning, and enable meaningful comparisons in research, ultimately reducing perioperative morbidity and mortality.

This review aims to conduct a systematic literature search to identify all available classification systems for GIH, critically assess their limitations, and propose recommendations for a more comprehensive and clinically useful classification system.

A THREE-GRADE CLASSIFICATION SYSTEM FOR GIH

In longstanding inguinal hernias, there is an associated visceromegaly of the content of the hernia sac arising from increased blood supply. In the Classification of GIH by Trakarnsagna et al.,^[8] the authors did not consider the loss of domain nor the possibility of visceromegaly of the content of the hernia sac [Table 1]. Furthermore, there were no indications for either the resection of the sac content or the procedures for increasing the abdominal volume. Hence, this classification could not predict abdominal compartment syndrome in patients with GIH.

CLASSIFICATION BY THE EUROPEAN HERNIA SOCIETY (EHS)

The classification of scrotal hernias in 2021 by the EHS^[9] did not consider the definition of GIH, a scrotal hernia extending beyond the mid-thigh. In this classification, the S2 class of scrotal hernias lies in the middle third of the thigh. In addition, this classification does not allow for the perioperative risk stratification of patients and the early identification of patients with loss of domain who might develop abdominal compartment syndrome in the postoperative period. Patients with loss of domain may require different strategies, such as pre-operative progressive pneumoperitoneum or Botox injection, to prevent abdominal compartment syndrome [Table 2].

A FOUR-GRADE CLASSIFICATION SYSTEM FOR GIH

In the classification by Muhammad Hussain Laghari, the grade 1 GIH^[10] does not include a landmark for diagnosing GIH (the mid-thigh). Furthermore, the authors did not discuss which of the grades the hernia sac contents could be reduced without resection or increasing the intra-abdominal volume [Table 3].

CLASSIFICATION BASED ON ENGULFMENT OF PHALLUS BY REDUNDANT SCROTAL SKIN

The classification by Akpo ^[2] for bilateral giant inguinoscrotal hernia is mainly about the engulfment of the phallus by the redundant skin of the scrotum. This classification was based on the challenges patients with bilateral GIH had achieving vaginal penetration of their partners during coitus. Besides, a significant percentage presented due to their partners refusing coitus. It did not discuss the possible management options for reducing postoperative abdominal compartment syndrome.

CLASSIFICATION BASED ON SCROTAL VOLUME (SV)

In a study by Ertem et al.,^[11] it was reported that there was no difference between the SV measured by computed tomography (CT) scan and hand measurements. Giant scrotal hernias are diagnosed when the SV is more than 1000 mL. The authors suggested that SV of >3000 mL necessitates the comparison of abdominal compartment volume (ACV) to SV. If the SV/ACV ratio is >25%, there is a high risk of loss of domain, and this may predispose to abdominal compartment syndrome if precautionary procedures are not done. This classification might be impractical in most low-resource countries, where scrotal hernias are most prevalent and do not have consistent access to CT scan due to high cost.

In Dumbuya et al.’s classification,^[12] hernias were classified based on the sac volume. This classification requires a CT scan to determine the SV, which might not be readily available in a low-resource setting.

CLASSIFICATION OF THE RISK OF ABDOMINAL COMPARTMENT SYNDROME

In the classification by Oyewale et al., even though visceromegaly of the sac content and loss of domain were noted, there was no inclusion of the inguinoscrotal hernias above the mid-thigh level.^[1] Another drawback of this classification is the need for a CT scan to determine the visceromegaly of the content of the hernia sac.

We propose modifying the above classification to include massive inguinoscrotal hernias, which lie above the mid-thigh level [Table 4].

DISCUSSION

Without standardized criteria, what one surgeon considers a “giant inguinal hernia” may differ from another’s assessment, leading to management and research reporting inconsistencies. A standardized, universally accepted system is essential to improving clinical outcomes, enhancing research comparability, and facilitating international collaboration. Future consensus-driven revisions should prioritize clear definitions of the landmarks and provide practical utility to identify patients at risk of abdominal compartment syndrome after GIH repair.

Most available classification systems fail to account for critical factors such as hypertrophy of the content of the hernia sac, loss of domain, and the degree of scrotal wall distortion or ulceration. The EHS recently introduced a classification for inguinoscrotal hernias. However, the landmarks of the S2 type of scrotal Hernia overlapped the mid-thigh, the nodal point for defining giant inguinoscrotal hernias. While the EHS classification represents progress, it does not fully address the complexities of inguinoscrotal hernias, particularly giant cases. Understandably, most of the GIH cases are seen in sub-Saharan Africa. At the same time, many of the experts who drafted the EHS classification were Europeans who might not have managed such challenging cases of GIH.

Although “loss of domain” could be used to predict operative difficulty and success, there are multiple definitions among hernia surgeons.^[13] There has not been a uniform definition for this terminology among individuals who have had hernia repair for GIH. The eventration of the viscera causes disuse atrophy and irreversible muscular fibrosis.^[14] These predispose the patients to respiratory failure. In addition, there is an associated venous stasis, ischemia, and edematous bowel with consequent hypertrophy of the hernia sac content.^[15] Reduction of such hernia sac content will lead to abdominal compartment syndrome.

The classification of GIH was based on four broad groupings. These included skin redundancy,^[2] risks of abdominal compartment syndromes,^[1] SV,^[11,12] and lower-limb landmarks alone.^[8-10] The oldest article on GIH classification was published in 2014^[8] while the most cited article was Trakarnsagna et al.^[8]

There is still a need for a Delphi consensus study among academic hernia surgeons to standardize the available classification systems. Several of the participants for the proposed study should be based in low- and middle-income countries to provide experience with managing GIH. Finally, any new classification for GIH should incorporate the other three themes (risk of abdominal compartment syndrome, skin redundancy, and SVs) and the landmarks in the lower limbs.

CONCLUSION

All the available classification systems discussed above are plagued with varying limitations. Hence, the absence of a standard classification system for inguinoscrotal hernias has made comparison difficult. The recent classification of inguinoscrotal hernias by the EHS could not fill this gap because the authors did not factor in the landmark for defining giant inguinoscrotal hernias in their classification. Academic hernia surgeons need to revisit the classification for GIH in a future consensus meeting or study. This study will have to involve the hernia surgeons living in the LMIC.