The etiology of indirect inguinal hernia in adults: congenital, acquired or both?

Abstract

We have read the paper ‘‘The etiology of indirect inguinal hernia in adults: congenital or acquired?’’ by Jiang et al. [1] with great attention and interest. A most significant finding published in the paper is the presence of smooth muscle cells (SMC) in the neck of most hernia sacs (HS) of adult patients with indirect inguinal hernia (IIH). They describe these SMCs as forming bundles, a characteristic formation observed in our specimens as well, harvested from a pediatric population [2]. These data support, a posteriori, the theory on the etiology of pediatric IIH proposed by several authors, including ourselves [2, 3] and offer important arguments for the extension of the theory to the adult type IIH. In fact, a unified theory on the development of both pediatric and adult types IIH could be suggested. More precisely, we consider that the quantity and distribution of the SMCs on the processus vaginalis peritonei (PV) play an important role in its development. The SMCs that are distributed all over the PV wall, hinder its natural course towards obliteration, transforming it into a funiculum through which abdominal viscera protrude, thus creating the infantile type of IIH. On the contrary, if SMCs are located only in the neck of the PV (having regressed in the rest of the PV through the process of apoptosis), the obliteration of the PV is hindered only at this point. In these circumstances, IIH does not appear during infancy or early childhood (infantile type of IIH). Instead, after a considerable time period of pressure on the remnant of the PV, which acts as a focal point of pressure accumulation, a protrusion is gradually created through its unobliterated neck, leading to the formation of the adult type IIH. Finally, which one is the correct answer to the question asked by Jiang et al. in the title of their paper? If we accept that with the term ‘‘congenital indirect hernia’’ we describe any clinically observed hernia, appearing at any age, caused by a PV remaining open in any part [4], then, according to the above mentioned theory, the adult type IIH can be considered as a congenital hernia. But we choose to be more pragmatic. Jiang et al. recognized two parts with different characteristics in the HS that they examined, and considered them as having developed in separate timing caused by a different stimulus. One part is congenital and primary in nature and the other is secondary and acquired. So, we consider answering the question as follows: adult type IIH is both, congenital and acquired, at least in those cases where SMCs are found in the neck of HS.