Long-term follow-up of a randomized controlled trial of Lichtenstein repair vs the Valenti technique for inguinal hernia

The concept of the PAD method (from Italian: Protesi Autoregolantesi Dinamica) introduced by the Italian surgeon Gabrielle Valenti in 1992 is based on an attempt to combine advantages of the Lichtenstein technique (low recurrence rate) with the comfort achieved following repair surgeries involving no suturing (minimal pain) [6]. In 1999, Valenti presented the results of treatment of a group of 500 patients with the new method [4]. At that time, he paid attention primarily to minor pain in the postoperative course. For the majority of patients, painkillers were necessary only on the first day after the repair procedure. Similar results were obtained by us. From the second postoperative day onwards, patients scored their pain below 3 on the VAS scale [7]. Based on an analysis of 585 hernioplasties, Valenti reported the presence of pain in just 5.1% of patients after 4 weeks and of persistent neuralgia in just 0.3% [5]. A small percentage of patients with persistent pain may be the result of using only two single sutures securing the mesh to the rectus sheath in the Valenti method. This avoids damage to the iliohypogastricus and the ilioinguinalis nerve fibers, which is possible in the Lichtenstein method [8, 9]. Other applied sutureless methods are also associated with less pain in the early postsurgical period. The comfort associated with the use of sutureless methods (e.g., PHS, UHS) is a result of the absence of nerve fiber compression. However, in those methods, a component of the mesh is introduced into the preperitoneal space. Treatment in this space is extremely difficult in cases of mesh infection [10]. The Valenti method does not involve interference with the preperitoneal space, and thus, these complications may be avoided. Additionally, newly introduced techniques involving adhesives for mesh fixing or self-gripping meshes offer the potential to minimize postsurgical pain, but there are concerns regarding their effect on the recurrence rate [11, 12].

In the presented material, Valenti did not find any recurrent hernia [4]. This may be due to the lack of tissue tension within the surgical area, which is consistent with the current guidelines for the treatment of hernias. A change in body position is associated with a significant change in the relative position of the inguinal ligament and broad muscles of the abdomen. The distance between the inguinal ligament and the rectus muscle is increased, and the abdominal wall bulges. For this reason, securing the mesh components to only one edge makes the mesh rest freely on the posterior wall of the inguinal canal, and after the patient changes position, it assumes a natural, free position, and only in this optimal position is the mesh overgrown by connective tissue. This avoids uncontrolled creasing of the mesh, which is possible with the Lichtenstein method. Maintaining the flat shape of the mesh components results in protection of the entire surface of Hesselbach’s triangle, thus preventing relapse.

Performing inguinal hernia repair using the Valenti method is an uncomplicated procedure. Valenti uses prefabricated polypropylene mesh components with a precisely defined shape. The use of a single standard model eliminates the need to trim mesh as in the Lichtenstein surgery. The size and shape of the meshes in the Valenti method were developed on the basis of anthropometric studies and constitute a universal solution for adult patients [4]. The use of only six single sutures securing the mesh components to anatomical structures in precisely defined places eliminates the variability associated with methods of mesh securing applied in other methods (continuous or single sutures, more or less dense points of passing the needle, etc.). Principles defined in the Valenti method result in uniformization of the course of the surgical procedure, even if performed in different centers. Simple principles and the absence of technical challenges make this surgical procedure clear, logical and easy to complete, even for less-experienced surgeons. The most important advantage of the Valenti method is the maintenance of all general assumptions of the Lichtenstein method [4, 6]. Those assumptions are a 2-cm margin over the pubic tubercle, at least a 3-cm margin beyond Hasselbach’s triangle, and a 5-cm mesh margin lateral to the deep ring. Therefore, the entire area of reduced strength is fully covered with mesh.

The use of two meshes in the Valenti method results in the creation of a valve system immediately after the surgery, reinforcing the area of the internal ring. A similar mechanism is used in the Desarda method, offering outcomes similar to those of the Lichtenstein method, despite the absence of a mesh [13]. This is also the reason for not creating a spermatic cord opening in the Lichtenstein method. In the original method, tails of the mesh are crossed, creating a valve mechanism suspending the spermatic cord at the level of the deep inguinal ring [4, 6]. In the Valenti method, with the increasing tension of abdominal muscles, the smaller mesh pulls the internal ring medially and upwards, while the larger mesh with the semi-circular cut holds the spermatic cord downwards and laterally (towards the inguinal ligament). Thus, both components form a valve preventing the bulging of the peritoneum.

Initially, we were concerned about the necessity for using two meshes, one on top of the other. This raises concerns about the increased risk of infections or the development of a seroma [14]. However, the results presented by Valenti indicated an absence of that type of correlation. It seems that a total absence of tension and creasing is responsible for that mechanism. In other methods involving the use of meshes, surgeons usually try to avoid creasing or stacking meshes due to concerns about dead spaces between mesh fibers. The results of our previous observations confirmed that laying two meshes flat, with no tension, one over the other, does not increase the risk of seroma and infections, even without the use of macropore meshes [7].

Recurrences after inguinal hernia repair may occur even after 5 years of follow-up, at a rate close to 4% [15]. However, that is still a significantly lower rate compared to that of suture repair. Hence, the number of recurrences is the basic parameter used for the assessment of the treatment outcome. Despite using a smaller mesh size than that usually used in the Lichtenstein method (6 × 11 cm for the Valenti vs 10 × 15 cm for the Lichtenstein method), the Valenti method ensures a low rate of recurrence. We observed four cases of recurrence in each study group, which constituted approx. 2%. The detailed analysis of the circumstances of the recurrence showed that for the Valenti method, in two cases, it was the result of a lack of identification of a concomitant oblique hernia while repairing only the medial defect in the bottom of the inguinal canal (early relapses). A flat position of both meshes and the absence of any deformations was observed during repeated surgical procedures in these patients. Both meshes were fused, and they could no longer be separated. The low, long-term recurrence rate confirms a similar efficacy of both methods.

In the face of similar results for treatment efficacy with both methods, the assessment of long-term pain may be important. It is estimated that pain of various intensities may occur in 0.3–32% of patients. At the same time, strong pain, affecting the patient’s everyday functioning, usually occurs in less than 3% of patients. The precise mechanism responsible for the development of pain is not fully understood, and its multifactorial etiology is postulated [16]. In the analyzed material, we demonstrated that the number of patients suffering persistent pain was similar in both groups. Considering the lack of correlation between chronic pain and the surgical technique, it can be presumed that the use of two complementary meshes in the Valenti method does not result in greater nerve damage that promotes chronic neuralgia.

The limitation of this work is the long-term assessment of just over 70% of patients, although the majority of patients lost to follow-up were not related to the treatment. At the same time, a comparative analysis of groups of patients lost and maintained in the study did not show differences between them. This is the largest available long-term analysis of treatment results using the Valenti method and the first long-term analysis of the use of two flat meshes placed on each other. However, additional studies are needed to confirm the results.