Histological findings of the internal inguinal ring in patients having indirect inguinal hernia

Physiologic Cyclical Load on Inguinal Hernia Scaffold ProFlor Turns Biological Response into Tissue Regeneration

Surgical repair of groin protrusions is one of the most frequently performed procedures. Currently, open or laparoscopic repair of inguinal hernias with flat meshes deployed over the hernial defect is considered the gold standard. However, fixation of the implant, poor quality biologic response to meshes and defective management of the defect represent sources of continuous debates. To overcome these issues, a different treatment concept has recently been proposed. It is based on a 3D scaffold named ProFlor, a flower shaped multilamellar device compressible on all planes. This 3D device is introduced into the hernial opening and, thanks to its inherent centrifugal expansion, permanently obliterates the defect in fixation-free fashion. While being made of the same polypropylene material as conventional hernia implants, the 3D design of ProFlor confers a proprietary dynamic responsivity, which unlike the foreign body reaction of flat/static meshes, promotes a true regenerative response. A long series of scientific evidence confirms that, moving in compliance with the physiologic cyclical load of the groin, ProFlor attracts tissue growth factors inducing the development of newly formed muscular, vascular and nervous structures, thus re-establishing the inguinal barrier formerly wasted by hernia disease. The development up to complete maturation of these highly specialized tissue elements was followed thanks to biopsies excised from ProFlor from the short-term up to years post implantation. Immunohistochemistry made it possible to document the concurrence of specific growth factors in the regenerative phenomena. The results achieved with ProFlor likely demonstrate that modifying the two-dimensional design of hernia meshes into a 3D outline and arranging the device to respond to kinetic stresses turns a conventional regressive foreign body response into advanced probiotic tissue regeneration.

Dynamic Responsive Inguinal Scaffold Activates Myogenic Growth Factors Finalizing the Regeneration of the Herniated Groin

BACKGROUND

Postoperative chronic pain caused by fixation and/or fibrotic incorporation of hernia meshes are the main concerns in inguinal herniorrhaphy. As inguinal hernia is a degenerative disease, logically the treatment should aim at stopping degeneration and activating regeneration. Unfortunately, in conventional prosthetic herniorrhaphy no relationship exists between pathogenesis and treatment. To overcome these incongruences, a 3D dynamic responsive multilamellar scaffold has been developed for fixation-free inguinal hernia repair. Made of polypropylene like conventional flat meshes, the dynamic behavior of the scaffold allows for the regeneration of all typical inguinal components: connective tissue, vessels, nerves, and myocytes. This investigation aims to demonstrate that, moving in tune with the groin, the 3D scaffold attracts myogenic growth factors activating the development of mature myocytes and, thus, re-establishing the herniated inguinal barrier.

METHODS

Biopsy samples excised from the 3D scaffold at different postoperative stages were stained with H&E and Azan-Mallory; immunohistochemistry for NGF and NGFR p75 was performed to verify the degree of involvement of muscular growth factors in the neomyogenesis.

RESULTS

Histological evidence of progressive muscle development and immunohistochemical proof of NFG and NFGRp75 contribution in neomyogenesis within the 3D scaffold was documented and statistically validated.

CONCLUSION

The investigation appears to confirm that a 3D polypropylene scaffold designed to confer dynamic responsivity, unlike the fibrotic scar plate of static meshes, attracts myogenic growth factors turning the biological response into tissue regeneration. Newly developed muscles allow the scaffold to restore the integrity of the inguinal barrier.

Fixation free laparoscopic obliteration of inguinal hernia defects with the 3D dynamic responsive scaffold ProFlor

Laparoscopic TAPP/TEP approaches are well-established options for the cure of inguinal hernias. As in the open approach, mesh fixation and poor-quality biologic response represent controversial questions and are a source of concerns. Furthermore, hernia defect patency represents another problem which seems not well acknowledged among surgeons. These problems are considered the cause of frequent intra and postoperative complications. To overcome these concerns, recently a different concept of cure has emerged. Based on a newly developed dynamic responsive 3D scaffold named ProFlor, a permanent hernia defect obliteration has been finalized. Following its inherent centrifugal expansion due to its dynamic responsivity, this hernia device is positioned fixation free within the defect and induces a probiotic biological response allowing for the re-establishment of the degenerated inguinal barrier. A laparoscopic approach with the 3D scaffold has been tested on 71 patients to demonstrate its effectiveness in reducing intra and postoperative complications. The operated patients presented with bilateral and/or recurrent inguinal hernia. Overall, 122 hernia defects were obliterated with 119 dynamic responsive scaffolds. The procedures were carried out from January 2018 to January 2022 with a defined protocol and detailed procedural steps. The laparoscopic technique with the 3D hernia scaffold allowed for fixation free placement, permanent defect obliteration and dynamically induced regenerative effects. The technique proved effective in reducing intra and postoperative complications. In particular, early postoperative pain and discomfort significantly decreased. No chronic pain and no recurrences were reported during follow up. The results achieved with the described laparoscopic technique seem to embody an innovative concept for inguinal hernia repair. Fixation free, dynamic responsive, permanent defect obliteration, histologically proven regenerative effects are the distinctive features of this 3D scaffold. It seems to embody a more physiological and pathogenetically coherent concept of cure, thus improving treatment results of this widespread disease.

A regenerative 3D scaffold for inguinal hernia repair. MR imaging and histological cross evidence. Qualitative study

BACKGROUND

Inguinal hernia is a degenerative disease occurring in a high motile surround. Stopping degeneration and promoting tissue regeneration should be the treatment goal. Groin hernias are conventionally managed with static flat meshes, mostly fixated to the delicate inguinal environment. Far from a regenerative effect, the biologic response of conventional hernia meshes is characterized by a foreign body reaction leading to a stiff/shrunken scar plate, which is often the source of unpleasant complications. Recently, a newly engineered 3D device for inguinal hernia repair - ProFlor-has been developed to produce a regenerative biological response. Unlike conventional hernia meshes, this regenerative 3D hernia scaffold seems to demonstrate suitable features for a pathogenetical and physiological coherent treatment of the disease. The aim of this manuscript is to cross evidence these features through magnetic resonance imaging (MRI) and histology.

STUDY DESIGN

The biological response of ProFlor at three defined post-implantation stages has been evaluated through MRI signal intensity and compared to neighbouring muscles and fat. As additional proof, histology of tissue specimens excised at the same post-implantation periods from porcine models during an experimental attempt were also evaluated.

RESULTS

MRI of newly ingrown tissue in ProFlor demonstrated similar signal intensity of muscles while fat tissue showed remarkably higher values. These data matched with the histology of ProFlor biopsies excised from pigs.

CONCLUSIONS

The motile compliance to groin movements of ProFlor appears to induce a probiotic biologic response comparable to a regenerative scaffold, allowing to physiologically resolve the degenerative source of inguinal hernia disease.

Inguinal Hernia: Defect Obliteration with the 3D Dynamic Regenerative Scaffold Proflor™

Prosthetic inguinal hernia repair presents significant challenges. Some of these, such as mesh fixation and quality of the biologic response, are still debated among surgeons. For example, there is no strong consensus regarding a specific condition that characterizes the surgical procedure during herniorrhaphy. This issue concerns management of the hernia defect, which in conventional hernia repair with flat meshes remains patent. However, a critical analysis of typical postoperative complications after inguinal hernia repair reveals that some of these adverse events are related to patency of the hernial opening. Postoperative discomfort, pain with specific movements and even hernia recurrence can be caused by incomplete or defective management of the hernia defect. For this reason, a deeper understanding of this topic would be useful for improving postoperative outcomes. A recently updated concept for inguinal hernia repair takes this technical aspect into consideration. It is based on the use of a newly developed 3D scaffold-ProFlor™ (Insightra Medical, Inc., Clarksville, TN, USA)-that is intended to be deployed into the defect. This novel hernia repair device has interesting and original features, such as dynamic responsivity in compliance with inguinal movement, fixation-free mode and regenerative behavior that counteracts the degenerative effects of the disease. Another additional proprietary feature of this 3D scaffold is the full and permanent obliteration of the defect, which is a crucial aspect to improve outcomes by avoiding the typical adverse effects of this surgical procedure. Obliteration of the hernia defect with the 3D dynamic regenerative scaffold ProFlor™ appears to be superior to coverage by means of static (passive) flat meshes/plugs used in conventional hernia repair. This report highlights the principles of this procedural approach.

Enhanced angiogenesis in the 3D dynamic responsive implant for inguinal hernia repair ProFlor

Biologic response to hernia prostheses represents a continuous source of debate. Conventional hernia meshes, in their typical static, passive configuration have been used for decades to reinforce the herniated abdominal wall. These flat implants, mainly fixated with sutures or tacks, induce poor quality fibrotic ingrowth that shrinks the mesh. In groin hernia repair, flat meshes are applied in the delicate inguinal surrounding where uncontrolled development of a scar plate can impair movement and may incorporate the sensitive nerves crossing this area. Complications deriving from mesh fixation and nerve entrapment are frequent and unpleasant for patients. To remedy these problems, a multilamellar shaped 3D device with a dynamic responsive behavior has recently been developed to repair inguinal hernia. Its inherent dynamic compliance during inguinal movements has shown to induce enhanced biological response with ingrowth of newly formed connective tissue, muscle fibers, and nerves. The function of these highly specialized tissue structures is supported by the contextual development of newly formed arteries and veins. The scope of the study was to assess quantity and quality of vessels, which had ingrown in the 3D hernia device in the short-term, medium-term, and long-term post-implantation, in biopsy specimens gathered from inguinal hernia patients operated with the 3D device. Starting from an early stage, widespread angiogenesis was evident within the 3D structure. Arteries and veins increased in quantity showing progressive development until full maturation of all specific vascular components throughout the mid-term, to long-term, post-implantation. High quality biologic ingrowth in hernia prosthetics needs an adequate vascular support. The broad network of mature arteries and veins evidenced herewith seems to confirm the enhanced biological features of the dynamic responsive 3D device whose features resemble a regenerative scaffold, an ideal feature for the treatment of the degenerative source of inguinal hernia disease.

The Septum Inguinalis: A Clue to Hernia Genesis?

Purpose: Double ipsilateral inguinal ("pantaloon") hernias and also the more advanced "combined" inguinal hernia involve disruption of the inguinal floor. In the case of pantaloon hernias, the medial boundary of the internal ring remains intact but in combined hernias this is fully disrupted, producing a single hernial protrusion. Deepening the pathophysiology of these hernias may be helpful in addressing hernia genesis, thus improving strategies for the treatment of this disease. Materials and Methods: A cohort of 22 patients who underwent inguinal hernia repair showed double ipsilateral (pantaloon) hernia, comprising distinct direct and indirect protrusions separated by a tissue septum. In 19 patients, the septal arrangement dividing the 2 hernias showed macroscopically evident structural damages, then excised and histologically studied. Different tissue markers were used for the identification of the structural damages. Results: Macroscopically, the divisor septum represents the boundary between internal ring and Hesselbach's triangle. Anteriorly it is composed by fibers of the internal oblique and transverse muscles, which form a complex with the inferior epigastric vessels on the corresponding posterior side of the inguinal floor. In the patient cohort studied, this anatomical structure showed a progressive sufferance characterized by chronic compressive damage. Conclusion: The anatomical structure which separates the indirect and direct components of a pantaloon hernia, herein referred to as the "septum inguinalis", has been shown progressively alter in both macro- and microscopically until it f undergoes disruption with development of a combined hernia. Understanding of this anatomical concept may help surgeons to perform sound repairs of these complex hernias.

Shift from androgen to estrogen action causes abdominal muscle fibrosis, atrophy, and inguinal hernia in a transgenic male mouse model

Inguinal hernia is one of the most common disorders that affect elderly men. A major pathology underlying inguinal hernia is the fibrosis and other degenerative changes that affect the lower abdominal muscle strength adjacent to the inguinal canal. Here we describe a critical role of estrogen and its nuclear receptor that enhance fibroblast proliferation and muscle atrophy, leading to inguinal hernia. Further research may reveal a potential role of estrogen ablation to prevent muscle fibrosis or hernia in a subset of elderly men.

Inguinal hernia develops primarily in elderly men, and more than one in four men will undergo inguinal hernia repair during their lifetime. However, the underlying mechanisms behind hernia formation remain unknown. It is known that testosterone and estradiol can regulate skeletal muscle mass. We herein demonstrate that the conversion of testosterone to estradiol by the aromatase enzyme in lower abdominal muscle (LAM) tissue causes intense fibrosis, leading to muscle atrophy and inguinal hernia; an aromatase inhibitor entirely prevents this phenotype. LAM tissue is uniquely sensitive to estradiol because it expresses very high levels of estrogen receptor-α. Estradiol acts via estrogen receptor-α in LAM fibroblasts to activate pathways for proliferation and fibrosis that replaces atrophied myocytes, resulting in hernia formation. This is accompanied by decreased serum testosterone and decreased expression of the androgen receptor target genes in LAM tissue. These findings provide a mechanism for LAM tissue fibrosis and atrophy and suggest potential roles of future nonsurgical and preventive approaches in a subset of elderly men with a predisposition for hernia development.

Muscle degeneration in inguinal hernia specimens

BACKGROUND

There are few articles in the literature reporting the histological changes of groin structures affected by inguinal hernia. A deeper knowledge of this matter could represent an important step forward in the identification of the causes of hernia protrusion. This study aimed to recognise the pathological modifications of muscular structures in autopsy specimens excised from tissues surrounding the hernia orifice.

METHODS

Inguinal hernia was identified in 30 autopsied cadavers, which presented different varieties of hernia, including indirect, direct and mixed. Tissue specimens were resected for histological study from structures of the inguinal area surrounding the hernia opening, following a standardised procedure. The histological examination was focussed on the detection of structural changes in the muscle tissues. The results were compared with biopsy specimens resected from corresponding sites of the inguinal region in a control group of 15 fresh cadavers without hernia.

RESULTS

Significant modification of the muscular arrangement of the inguinal area was recognized. Pathological alterations such as atrophy, hyaline and fibrotic degeneration, as well as fatty dystrophy of the myocytes were detected. These findings were observed consistently in the context of multistructural damage also involving vessels and nerves. In cadavers with hernia these alterations were always present independent of hernia type. No comparable damage was found in control cadavers without hernia.

CONCLUSIONS

The high degree of degenerative changes in the muscle fibres in the inguinal area involved in hernia protrusion described in this report seems to be consistent with chronic compressive damage. These alterations could embody one important factor among the multifactorial sources of hernia genesis. Conjectures concerning its impact on the physiology and biodynamics of the inguinal region are made. The relationship between the depicted degenerative injuries and the genesis of inguinal hernia is also a focus of discussion in this article.

A new prosthetic implant for inguinal hernia repair: its features in a porcine experimental model

Even after more than 100 years of inguinal hernia repair, the rate of complications and recurrence remains unacceptably high. In the last decades, few effective advances in surgical technique and materials have been made. The authors see them as minor adjustments in the shape and materials of the prosthetic implants. Still, the underlying genesis of inguinal hernia remains undefined. Based upon this, it seems the surgical repair of inguinal protrusions cannot be based upon the pathogenesis because the etiology to date has not been addressed. Most hernia repairs are performed with some degree of point fixation (sutures/tacks) to stop the mesh from migrating and creating high recurrence rates. This should be a priority for our considerations, as fixating mesh puts it in stark contrast to the physiology and dynamics of the myotendineal structures of the groin. Following years of surgical practice, implant fixation, mesh shrinkage, and poor quality of tissue ingrowth still represent an unresolved issue in modern hernia repair. Conventional prosthetics used for inguinal hernia repair are static and passive. They do not move in harmony with the dynamic elements of the groin structure and, as a result, induce the ingrowth of thin scar plates or shrinking regressive tissue that colonizes the implants. The authors strongly believe that these characteristics may be a contributing factor for recurrences and patient discomfort. Other complications are reported in the literature to be a direct result of fixation of the implants, such as bleeding, nerve entrapment, hematoma, pain, discomfort, and testicular complications. To improve results by respecting the physiology and kinetics of the inguinal region, we felt that a new type of prosthesis should be designed that induces a more structured tissue ingrowth similar to the natural biologic components of the abdominal wall. This prosthetic device was specifically designed to be placed with no point fixation. This was achieved by using inherent radial recoil, vertical buffering, friction, and delivering the device in a constrained state. A secondary benefit of this "dynamic" design is that the implant moves in a three-dimensional way in unison with the movements of the myotendineal structures of the groin. The results appear to show that the three-dimensional structure not only acts as a suitable scaffold for a full thickness ingrowth of a tissue barrier but also seems to induce an ordered, supple, elastic tissue, which allows for neorevascularization and neoneural growth. The outcomes indicate a reduced impact of fibrotic shrinkage on the implant/scar tissue when compared with shrinkage of polypropylene meshes reported in the literature. This pilot study shows the features of such an implant in a porcine experimental model.

Damage to the vascular structures in inguinal hernia specimens

BACKGROUND

Few scientific reports to date describe the histological modification of structures outlining a hernia opening. This article is focused on the identification of the pathological changes in vascular structures in tissues excised from cadavers with inguinal hernia. A deeper comprehension of this topic could lead to essential improvements in the detection of hernia genesis.

MATERIALS AND METHODS

Different kinds of hernia, including indirect, direct and mixed, were identified in 30 autopsied subjects. Tissue samples were resected for histological study from abdominal wall structures close to the hernia opening. Histological examination focused on the detection of structural changes in arteries and veins. The results were compared with tissue specimens excised from equivalent sites of the inguinal area in a control group of 15 fresh cadavers without hernia.

RESULTS

Significant modification of vascular structures were identified in the tissue specimens examined. The veins demonstrated parietal fibrosis, perivascular edema and vascular dilation due to congestion and stasis. The arterial structures detected showed thickening of the media due to medial hyperplasia, ranging from luminal sub-occlusion to a manifest artery occlusion. These findings are present independent of hernia type in cadavers with inguinal hernia. These pathological changes were lacking in the control group of cadavers without hernia.

CONCLUSIONS

The notable changes in vascular structures described in the report could be the result of a steady compressive effect exerted by the abdominal viscera in the inguinal area. These pathological changes could represent one of the factors involved in the weakening of the inguinal region leading to hernia protrusion.

Toxoplasma gondii infection and abdominal hernia: evidence of a new association

BACKGROUND

We performed a retrospective, observational study in 1156 adult subjects from the general population of Durango City, Mexico, Fifty five subjects with a history of abdominal hernia repair and 1101 subjects without hernia were examined with enzyme-linked immunoassays for the presence of anti-Toxoplasma IgG and IgM antibodies.

RESULTS

The seroprevalence of anti-Toxoplasma IgG antibodies and IgG titers was significantly higher in subjects with abdominal hernia repair than those without hernia. There was a tendency for subjects with hernia repair to have a higher seroprevalence of anti-Toxoplasma IgM antibodies than subjects without hernia. The seroprevalence of anti-Toxoplasma IgG antibodies in subjects with hernia repair was significantly higher in subjects ≥ 50 years old than those < 50 years old. Further analysis in subjects aged ≥ 50 years showed that the seroprevalence of anti-Toxoplasma IgG antibodies was also significantly higher in individuals with hernia repair than those without hernia (OR = 2.72; 95% CI: 1.10-6.57). Matching by age and sex further showed that the seroprevalence of Toxoplasma infection was significantly higher in patients with hernia repair than those without hernia (OR: 4.50; 95% CI: 1.22-17.33).

CONCLUSIONS

Results indicate that infection with Toxoplasma is associated with abdominal hernia. The contributing role of infection with Toxoplasma in abdominal hernia was observed mainly in subjects aged ≥ 50 years old. Our results might have clinical, prevention and treatment implications and warrant for further investigation.

Nerve degeneration in inguinal hernia specimens

BACKGROUND

The histological study of the herniated inguinal area is rare in the literature. This report is focused on the detection of structural changes of the nerves within tissues bordering the inguinal hernia of cadavers. Their physiopathological consequences are hypothesized.

MATERIALS AND METHODS

Primary inguinal hernia was diagnosed in 30 fresh cadavers. Tissue specimens from the inguinal region close to and around the hernia opening were excised for histological examination. A control of the data was achieved through tissue samples excised from equivalent sites of the inguinal region in 15 cadavers without hernia.

RESULTS

The detected nerves in the inguinal area demonstrated pathological changes such as fibrotic degeneration, atrophy, and fatty dystrophy of the axons. The thickening of the perineural sheath was constantly seen. These findings were consistently present, independent of the hernia type.

CONCLUSIONS

The detected nerve alterations lead us to imagine a worsening, or even the cessation, of the nervous impulse to the muscles, leading to atrophy and weakening of the abdominal wall. This could represent one of the multifactorial causes of hernia genesis.

Internal Ring Occlusion and Floor Support: A Novel Technique for Inguinal Hernia Mesh Repair

Tension-free, open-mesh, inguinal herniorrhaphies have gained wide acceptance. Current mesh techniques reinforcing the internal ring do not provide a comfortable lay to the mesh. To address this, we used the internal ring occlusion and floor support (IROFS) technique. A retrospective review was undertaken of all hernias operated on with the IROFS technique from January 2001 to December 2006. Five hundred twenty-five inguinal hernia repairs were done in 477 male patients. Telephone questionnaires looking into their postoperative course and recurrence were recorded. We contacted 275 (58%) patients. Patients’ ages ranged from 29 to 81 years (mean, 57 years). The hernia was indirect in 50 per cent (n = 146), direct in 35 per cent (n = 102), or both in 15 per cent (n = 44) of patients. The average operative time was 40 minutes. Acute wound pain lasted for less than 1 week in 55 per cent (n = 151) and for 1 to 2 weeks in 24 per cent (n = 66). Postoperative analgesic requirement was less than 1 week in 54 per cent (n = 147) and 1 to 2 weeks in 27 per cent (n = 74). Most patients returned to their daily activities in 2 weeks (75%) and to work in 3 weeks (74%). Chronic pain lasted for 6 to 48 months (mean, 20 months) in only seven patients. No recurrence of hernia was observed during follow-up visits (range, 26-96 months; mean, 53 months). In conclusion, IROFS can be performed with little difficulty, is cost-effective, and is well tolerated by the patient.