Scientific Literature
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Muscle degeneration in inguinal hernia specimens
Amato G., Agrusa A., Romano G., Salamone G., Gulotta G., Silvestri F., Bussani R.
Published online October 2011
Link
Abstract
Background
There are few articles in the literature reporting on the histological changes of the 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 report aims to recognize 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 standardized procedure. The histological examination was focused on the detection of structural changes in the muscle tissues. The results were compared with biopsy specimens resected from correspondent places 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 have been recognized. Pathological alterations such as atrophy, hyaline and fibrotic degeneration, as well as fatty dystrophy of the myocytes were detected. These findings were constantly observed in a contest of multistructral damages also involving vessels and nerves. In cadavers with hernia these alterations were always present independently of hernia type. No comparable damages have been found in the control cadavers without hernia.
Conclusions
The high degree of degenerative changes of the muscle fibers in the inguinal area involved by the hernia protrusion described in this report, seems to be consistent with a chronic compressive damage. These alterations could embody one important factor among the multifactorial sources of hernia genesis. Conjectures concerning its impact in the physiology and biodynamics of the inguinal region are made. The relationship between the depicted degenerative injuries and the genesis of inguinal hernia also focuses the discussion in the article.
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A New Prosthetic Implant for Inguinal Hernia Repair: Its Features in a Porcine Experimental Model
Amato G., Lo Monte AI., Cassata G., Damiano G., Romano G., Bussani R.
Published August 2011
Link
Abstract
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.
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New mesh shape and improved implantation procedure to simplify and standardize open ventral hernia repair: a preliminary reportl
Amato G., Romano G., Goetze T., Salamone G., Agrusa A., Gulotta G., Paolucci V.
Published July 2011
Link
Abstract
Introduction
Issues in ventral hernia repair are represented by the need for mesh fixation and how to assure a sufficient mesh overlap of the defect. Aiming to resolve these problems, this study describes a modified technique for ventral and incisional hernia repair based upon a newly developed mesh with a special design. This new type of implant allows broader coverage of the abdominal wall and results in tension- and fixation-free repair.
Materials and methods
A unique geometrically shaped mesh consisting of a large central body and radiating arms was used to repair ventral or incisional hernia. The mesh was intended not to be point-fixated. The friction of the straps passing through the tissues was hypothesized to be adequate to maintain the mesh firmly fastened in the abdominal wall, ensuring a wide coverage far from the hernia border. The newly designed mesh was placed in the preperitoneal sublay in 22 patients with ventral or incisional hernia. All straps were passed laterally through the transverse and oblique muscles. In all patients, a defect overlap of at least 8–12 cm was achieved.
Results
In a midterm follow-up of 18–24 (mean 22) months, three seromas and one infection occurred, which were successfully managed without mesh removal. No hematoma, chronic pain, or recurrence has been reported to date.
Conclusions
The described arm system of the implant allowed for a much smaller incision and eliminated the complicated maneuvers associated with suturing the mesh. The fixation arms seemed to have ensured the mesh stayed orientated in all patients. A very wide lateral mesh placement was accomplished, assuring sufficient defect overlap when shrinkage occurs.
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Damage to the vascular structures in inguinal hernia specimens
Amato G., Romano G., Salamone G., Agrusa A., Saladino V. A., Silvestri F., Bussani R.
Published July 2011
Link
Abstract
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.
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Nerve degeneration in inguinal hernia specimens
Amato G., Ober E., Romano G., Salamone G., Agrusa A., Gulotta G., Bussani R.
Published October 2010
Link
Abstract
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.
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Prosthetic strap system for simplified ventral hernia repair:results of a porcine experimental model
Amato G., Romano G., Agrusa A., Cassata G., Salamone G., Gulotta G.
Published March 2010
Link
Abstract
Introduction
Aiming to achieve a simplified ventral hernia repair, a proprietary oval-shaped mesh was experimentally tested in a porcine model. The mesh is structured with a large central body and radiating straps. The friction of the straps passing through the tissues are hypothesized to be adequate to maintain the position of the mesh during tissue ingrowth, avoiding classic point fixation while ensuring a wide coverage of the abdomen.
Methods
The mesh, having six radial straps, was placed using a sublay preperitoneal technique in four pigs. All straps were passed laterally through the abdominal wall and exteriorized from the skin. The straps were trimmed at the level of the skin, allowing the stumps to recoil into the subcutaneous space. The animals were euthanized at 1 and 4 months to determine the integration of the straps.
Results
Macroscopically, all 24 straps were firmly incorporated within the abdominal wall. The tension-free placement of the mesh by using the straps was effective. The friction of the straps passing through the tissues was adequate to keep the mesh well orientated. No dislocation of the implants was observed. The strap system also allowed a broader coverage of the abdominal wall, far beyond the wound opening.
Conclusions
The described arm system of the aforementioned implant seems to be effective in eliminating point fixation of the mesh. The fixation arms seemed to have ensured that the mesh stayed orientated in all of the animals. A very wide lateral mesh placement was accomplished, assuring sufficient defect overlap when shrinkage occurs.
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Histological findings of the internal inguinal ring in patients having indirect inguinal hernia
Amato G., Marasa L., Sciacchitano T., Bell S. G.,Romano G., Gioviale M. C., Lo Monte A. I., Romano M.
Published February 2009
Link
Abstract
Background
Aiming to deepen the understanding of the factors involved in the genesis of groin hernia, this study is focused on identifying the histological changes within the muscle fibers of the internal inguinal ring in patients having indirect inguinal hernia.
Methods
In eight patients with primary or recurrent bilateral indirect inguinal hernia who underwent a Stoppa open posterior inguinal hernia repair, a tissue specimen from the edge of the internal inguinal ring was biopsied and histologically examined.
Results
In all of the tissue samples, remarkable degenerative changes such as fibrohyaline degeneration of the muscle fibers, vascular congestion, and phlogistic infiltration through lymphohistiocytary elements was constantly detected. Also, in the patients with recurrent hernia, the key characteristic of the muscular change was that of fibrohyaline and, occasionally, myxoid degeneration of the myocytes. Nerve endings were frequently detected within the muscular structures of the internal inguinal ring.
Conclusions
The degenerative fibrohyaline alteration, as well as the evidence of phlogistic elements within the examined structures, could represent a reason for a contractile incompetence of the internal inguinal ring. Consequently, the described findings lead the authors to depict this inflammatory degenerative structural weakness of the internal inguinal ring as a possible culprit of indirect inguinal hernia formation.
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Sphincter-like motion following mechanical dilationof the internal inguinal ring during indirect inguinal herniaprocedure
Amato G., Sciacchitano T., Bell S. G., Romano G., Cocchiara G., Lo Monte A. I., Romano M.
Published October 2008
Link
Abstract
Introduction
Even today, there is still great speculation as to the underlying pathogenesis of inguinal hernia. As a result, it could be extrapolated that the vast majority of repairs are based upon conjecture. Most current repairs are founded upon the principle of “closing the defect” in the anatomy, either by suturing closed under tension, covering with a mesh or obliterating the defect with a plug. Many variants of each method are refined to achieve better clinical outcomes. Yet few, if any, strive to understand a fundamental question: “What has gone wrong with the normal physiological and anatomical mechanisms that prevent abdominal structures protruding through the abdominal wall?” We consider, in the normal subject, the muscular structures that converge and wrap around the inguinal canal as a highly dynamic structure, which forms a reactive barrier to the augmentation of intra-abdominal pressures. In effect, the structures work together like a “striated sphincter complex.” Through years of surgical experience, we have seen the formation of adhesions and fibrosis in these delicate and key structures, and hypothesised that they may impair its shuttering action, thus, creating a patency of this jammed inguinal ring leading to hernia. Based upon these observations, we have created a hernia repair variant that tries to “unblock” the muscles prior to repair, thus, hopefully restoring a degree of physiologic function.
Materials and methods
A retrospective study describes the results of 47 patients operated for indirect inguinal hernia with a standardised procedure consisting of meticulous adhesiolysis of the hernia area and mechanical dilation (divulsion) of the inguinal orifice in order to break stiff fibres within the muscle, allowing viable muscle fibres to contract freely once more. After dilation, a proprietary lamellar-shaped implant was delivered into the canal. Its form and function are designed to eliminate impingement of the cord structures and give a gentle outwards force to induce a reactive contraction of the sphincter-like muscle complex during healing. This gentle contraction offers the possibility to eliminate fixation of the implant.
Results
The removal of scar tissue, dilation and the introduction of the implant into the internal inguinal ring induced a forceful “gripping” contraction by the sphincter complex in all patients. Even without fixation, it became almost impossible to pull the implant out of the canal. After obliterating the orifice with the lamellar implant, it was clear that there was no dilative compression upon the cord structures.
Conclusions
The results of this combined procedure, scar removal, dilation and implant delivery, led to thoughtful suggestions regarding the anatomy and the physiology of the inguinal canal. The procedural adhesiolysis during indirect inguinal hernia repair has always shown the well described concentric muscular arrangement formed by the internal oblique and transversus muscles. This circular-shaped muscular structure is often recognised as a static barrier that, due to weakness and/or together with other causes, fails in its role and allows indirect inguinal hernia protrusion. According to the results of our observations, we consider this concentric muscular complex as a dynamic formation: we will use the term “striated sphincter complex.” Its steady tightening motion after divulsion and the insertion of a lamellar implant is always accompanied by a strong gripping action, which is not seen prior to divulsion. This indicates that it could correspond to a sphincter: the “inguinal sphincter.” The impairment of this sphincter could be the cause of the inguinal canal’s patency and the development of hernia.