Adult groin hernias: new insight into their biomechanical characteristics

Collagenopathies-Implications for Abdominal Wall Reconstruction: A Systematic Review

Background:

The etiology of hernia formation is strongly debated and includes mechanical strain, prior surgical intervention, abnormal embryologic development, and increased intraabdominal pressure. Although the most common inciting cause in ventral hernias is previous abdominal surgery, many other factors contribute. We explore this etiology through an examination of the current literature and existing evidence on patients with collagen vascular diseases, such as Ehlers–Danlos syndrome.

Methods:

A systematic review of the published literature was performed of all available Spanish and English language PubMed and Cochrane articles containing the key words “collagenopathies,” “collagenopathy,” “Ehlers-Danlos,” “ventral hernia,” and “hernia.”

Results:

Three hundred fifty-two articles were identified in the preliminary search. After review, 61 articles were included in the final review.

Conclusions:

Multiple authors suggest a qualitative or quantitative defect in collagen formation as a common factor in hernia formation. High-level clinical data clearly linking collagenopathies and hernia formation are lacking. However, a trend in pathologic studies suggests a link between abnormal collagen production and/or processing that is likely associated with hernia development.

An evidence-based approach for laparoscopic inguinal hernia repair: lessons learned from over 1,000 repairs

In this educational article, we aim to provide a literature review on laparoscopic anatomy of the inguinal region. We share the lessons learnt from the 1,194 laparoscopic hernia operations we have performed in 16 years of experience, trying to provide an anatomical and physiological basis for surgeons. The current study reports a personal experience with a transabdominal preperitoneal (TAPP) hernioplasty procedure. A literature review using the keywords "hernia," "laparoscopic approach," and "hernia repair" was performed using the electronic biomedical database PubMed, Medline Extra, Embase, Biosis, Science Citation Index, Ovid and text books. Between January 1994 and December 2010, a total of 1,194 patients, males and females (average age, 56.7 years), underwent laparoscopic TAPP inguinal hernia repair. Following reduction of the hernia sac and creation of the preperitoneal flap, a polypropylene mesh (10 × 16) and four spiral tacks were placed. TAPP is easy to learn and perform. Through this approach, a much better view from the inguinal anatomy is achieved, and the procedure also offers a brief learning curve. Our patients reported minimal postoperative pain and returned to work after 5-10 days, which is in accordance with the general anesthesia series. During the follow-up period, 10% of seromas, 3% of scrotal hematomas, 1% of hemorrhages, and 3% of recurrent hernias were observed. It should be emphasized that we have not observed abscess formation or acute infection related to the presence of mesh.

Ultrastructural differences in rectus sheath of hernia patients and healthy controls

BACKGROUND

The etiology of inguinal hernia remains unclear. Research data indicate the presence of pathologic alterations within the connective tissue; their exact character remains the subject of dispute. The search for new methods to diagnose connective tissue abnormalities, and thoroughly explain the character of the ultrastructural alterations, continues.

MATERIALS AND METHODS

The study group included 10 male patients aged 18-60 y (five with primary inguinal hernia and five with acute appendicitis with no history of hernia). A specimen of the rectus muscle sheath was harvested from all of them upon surgery. The tissue samples were fixed and examined by spectrofluorometry and fluorescence microscopy, yielding fluorescence spectra and microscopic fluorescence images.

RESULTS

Both techniques have demonstrated significant differences between the biopsy samples harvested from hernia patients and healthy controls. The groups of fluorescence spectra were shifted relative to each other and showed maximum emission at different wavelengths after excitation with 350 nm light (arbitrarily chosen for one of the cross-link proteins). The spectra obtained for healthy controls were more homogenous, while the spectra of the hernia samples differed even between each other. In microscopic images, the difference was a more chaotic distribution of fluorophores in the samples obtained from hernia patients.

CONCLUSIONS

The evidence of significant differences between the samples harvested from the same location from hernia patients and healthy controls, found by fluorescence techniques, indicates the presence of abnormalities in the connective tissue forming the rectus muscle sheath. This area is not a part of the hernial defect, therefore, we can assume that the changes can be attributed to a generalized process.

Connective tissue alteration in abdominal wall hernia

BACKGROUND

The aetiology and pathogenesis of abdominal wall hernia formation is complex. Optimal treatment of hernias depends on a full understanding of the pathophysiological mechanisms involved in their formation. The aim of this study was to review the literature on specific collagen alterations in abdominal wall hernia formation.

METHODS

A computer-assisted search of the medical databases PubMed and Embase was performed, together with a cross-reference search of eligible papers.

RESULTS

Fifty-two papers were included. Collagen alteration depended on the type of hernia; there were more pronounced changes in patients with a direct inguinal hernia than in those with an indirect inguinal hernia, recurrent inguinal hernia or incisional hernia. A consistent finding was a significant increase in immature type III collagen relative to the stronger type I collagen in patients with a hernia. This resulted in thinner collagen fibres with a correspondingly diminished biomechanical strength. It has been suggested that these alterations are due to variation in the synthesis, maturation or degradation of collagen by matrix metalloproteinases, in combination or alone.

CONCLUSION

Hernia formation and recurrence is associated with altered collagen metabolism manifested by a decreased type I:III collagen ratio.

Role of TIMP-2 in Fascia Transversalis on Development of Inguinal Hernias

The exact reason for the development of inguinal hernia has not been completely determined. However, it is known that the fascia transversalis (FT) is one of the structures preventing development of hernias. In the etiology of the inguinal hernia, disorders in collagen metabolism have been proposed, and the role of metalloproteinases in remodeling the collagen has recently been of great importance. We could not encounter any study where the role of metalloproteinase inhibitors was evaluated in inguinal hernia. We obtained samples of FT from patients with direct and indirect hernia and used an immunohistochemical method to determine tissue inhibitor of metalloproteinase-2 (TIMP-2) expression. In the study group, samples of FT were taken during the operation from 45 patients, of which 35 were indirect and 10 were direct inguinal hernias. In the control group, samples of FT from various abdominal incisions were also taken from 45 patients with no hernia and operated upon for another pathology. TIMP-2 scores of a direct inguinal hernia were significantly less than those of the control group. However, no difference has been found between the TIMP-2 scores of an indirect inguinal hernia and those of the control group. Decreased TIMP-2 scores in patients with a direct inguinal hernia, compared with both the indirect inguinal hernia group and the control group, explain the reason for the increase in matrix metalloproteinase-2 (MMP-2) that has been proposed in some studies. Therefore, it can be expressed that a decreased activity of TIMP-2 plays a role in inguinal hernia development.

Lysyl oxidase like-1 dysregulation and its contribution to direct inguinal hernia

OBJECTIVE

The aetiology of inguinal hernia involves changes in collagen turnover and metalloproteinase expression; yet it is not known whether the elastic fibre system could also be affected. This study was designed to compare the expression of tropoelastin (TE), lysyl oxidase-like 1 (LOXL-1) and elastase in the transversalis fascia of patients with and without inguinal hernia.

MATERIAL AND METHODS

Transversalis fascia (TF) specimens were obtained from patients undergoing surgery for direct or indirect inguinal hernia (n = 20 each) and from multi-organ donors during organ procurement (controls, n = 16). The specimens were divided according to age (20-40/41-60 years). Tissues were immunohistochemically labelled using anti-tropoelastin, anti-LOXL-1 and anti-elastase antibodies and subjected to Western blot analysis. Relative amounts of LOXL-1 and TE mRNA were determined by real time RT-PCR in cultured cells obtained from the TF of patients and controls.

RESULTS

Significantly lower TE and LOXL-1 levels were observed in patients with direct inguinal hernia compared with controls or those with indirect hernia. In contrast, patients with direct inguinal hernia showed significantly higher elastase expression. In fibroblasts isolated from the TF, relative amounts of tropoelastin mRNA were lower for the hernia groups but differences were not significant. LOXL-1 mRNA levels were significantly lower in the direct hernia group compared to controls.

CONCLUSIONS

Our findings suggest that impaired elastic fibre function in the transversalis fascia of patients with direct inguinal hernia, reflected by diminished elastin synthesis and its enhanced enzyme degradation, contributes to the development of this type of hernia.

Work related aspects of inguinal hernia: a literature review

INTRODUCTION

There is a traditional belief that that an inguinal hernia can be the result of increased intra-abdominal pressure (IAP) and therefore the development of a hernia may be attributed to single strenuous or recurrent strenuous events. As a result of this, litigation in this area is frequent.

METHODS

Medline was searched for English language publications using the keywords of 'hernia' or 'hernia AND recurrence' combined with 'work related', 'physical activity' and 'intra abdominal pressure'. The reference lists of appropriate papers identified on the original search were also checked to identify all related publications.

RESULTS

The search revealed 268 papers of which 59 were identified as appropriate to the subject of this review. Although publications in this area are scarce, from the literature available to date, there is no evidence to support the idea that single or recurrent strenuous events or early return to work related activity should result in the formation or recurrence of an inguinal hernia.

CONCLUSION

Although immediate pain at the time of an intensive or recurrent activity followed by a new diagnosis of a hernia supports a link between the activity and the hernia occurrence, it is likely that a congenital or acquired weakness in the connective tissue or muscles of the patient meant that hernia occurrence was almost inevitable. This may have significant implications regarding 'work related' hernia and its associated litigation.

Quantitative and qualitative analysis of collagen types in the fascia transversalis of inguinal hernia patients

BACKGROUND

Inguinal hernia is the second most common surgical case in our field. The anatomical factors alone are not enough to explain the inguinal hernia. Studies show changes in the proportion and quantity of collagen fibers in the developing of inguinal hernia. The greater production of collagen type III compared to the type I could justify the thinning of the fascia transversalis and its weakness.

AIM

To determine the quantitative and qualitative changes of collagen in the fascia transversalis in inguinal hernia patients and compare them to findings from corpses without inguinal hernia.

METHOD

Prospective case-control study based on the biopsy of fascia transversalis of 27 patients and 24 corpses. The technique used was hematoxylin-eosin and picrosirius colorimetry.

RESULTS

The medium percent area of collagen (types I + III) and collagen type I, in both groups, show no statistic difference. The quantity of collagen type III was greater in the patients. Patients classified with Nyhus IIIa presented greater quantity of collagen type III.

CONCLUSION

There is no significant difference in the quantity of collagen in the fascia transversalis of patients compared to the controls. An increase in the quantity of collagen type III was found in patients with inguinal hernia and a greater quantity in those patients classified with Nyhus IIIa.

Systemic and vaginal biomechanical properties of women with normal vaginal support and pelvic organ prolapse

OBJECTIVE

The objective of the study was to compare the biomechanical properties of vaginal and systemic skin in women with and without pelvic organ prolapse.

STUDY DESIGN

In this cross-sectional study, 25 women with pelvic organ prolapse and 23 age-matched women with normal pelvic support were recruited from an office setting. A Cutometer MPA 580 and DermaLab skin probe were used to measure systemic biomechanical parameters and a 1.5 mm offset DermaLab skin probe was used for vaginal biomechanical measurements.

RESULTS

There were no significant differences in the baseline demographic, obstetrical, or gynecologic information between the 2 groups. There were no significant differences in the systemic biomechanical parameters between the 2 groups. Women with pelvic organ prolapse had significantly more extensible vaginal skin than women with normal pelvic support (initial stiffness index 7.3 vs 10.9 kpa, final stiffness index 5.9 vs 10.7 kpa; all P values less than .01). Furthermore, vaginal extensibility was related to pelvic organ prolapse quantification stage in a linear fashion.

CONCLUSION

Our findings suggest that local, rather than systemic, alterations in biomechanical skin properties are associated with pelvic organ prolapse.

Hernia fibroblasts lack beta-estradiol-induced alterations of collagen gene expression

BACKGROUND

Estrogens are reported to increase type I and type III collagen deposition and to regulate Metalloproteinase 2 (MMP-2) expression. These proteins are reported to be dysregulated in incisional hernia formation resulting in a significantly decreased type I to III ratio. We aimed to evaluate the beta-estradiol mediated regulation of type I and type III collagen genes as well as MMP-2 gene expression in fibroblasts derived from patients with or without history of recurrent incisional hernia disease. We compared primary fibroblast cultures from male/female subjects without/without incisional hernia disease.

RESULTS

Incisional hernia fibroblasts (IHFs) revealed a decreased type I/III collagen mRNA ratio. Whereas fibroblasts from healthy female donors responded to beta-estradiol, type I and type III gene transcription is not affected in fibroblasts from males or affected females. Furthermore beta-estradiol had no influence on the impaired type I to III collagen ratio in fibroblasts from recurrent hernia patients.

CONCLUSION

Our results suggest that beta-estradiol does not restore the imbaired balance of type I/III collagen in incisional hernia fibroblasts. Furthermore, the individual was identified as an independent factor for the beta-estradiol induced alterations of collagen gene expression. The observation of gender specific beta-estradiol-dependent changes of collagen gene expression in vitro is of significance for future studies of cellular response.

Etiology of inguinal hernia: ultrastructure of rectus sheath revisited

In the last decade, in the search for abdominal-wall hernia etiology, attention has been brought to alterations in the connective tissue ultrastructure as the probable etiological factor. These may cause weakening of connective tissue, which in turn may form ground for hernia formation. To investigate this hypothesis in depth, we compared the ultrastructure of the connective tissue in hernia patients and the control group. The study group consisted of five patients with primary inguinal hernia (Nyhus II = 4, Nyhus IIIa = 1). Another five patients posted for emergency appendectomy created the control group. Tissue specimens, harvested intraoperatively from the rectus muscle sheath (RAMS) and fixed in 4% glutaraldehyde, underwent staining by the Masson, H-E and methylene blue techniques and were assessed by microscopy (light and scanning electron). The examinations showed significant differences in the rectus sheath ultrastructure. They included altered architecture, placement and quantity of collagen and elastic fibers, differences in the caliber of individual fibers and disrupted ground matter-to-fiber ratio. In patients with hernias, chaotic arrangement of collagen fibers was seen, as well as their thinning and a decrease in the general amount of elastic fibers, replaced by ground matter. Our research has shown significant differences in the structure of the RAMS between patients with hernias and healthy individuals. This supports the theory linking connective tissue alterations with the etiology of hernia, and stating that these alterations include connective tissue at locations distant from the hernia site as well, as the rectus sheath itself does not form a hernial defect.

Evaluation of Skin Viscoelasticity in Type 1 Neurofibromatosis Patients

Neurofibromatosis type 1 (NF1) is a frequent autosomal dominant disease characterized by cutaneous benign tumors called neurofibromas. Surgery takes an important place in managing these skin disorders. However, skin distensibility and softness of NF1 patients quickly offset the surgical benefit. The aim of this study was to determine the rheological behavior of neurofibromas and compare it with healthy skin in an attempt to comprehend what leads to this phenomenon. Thirty patients were admitted to this study. A group of 24 healthy control subjects was also included. The skin elasticity was assessed by a noninvasive in vivo suction device (Cutometer) including 5 consecutive suctions. The assessments were performed on neurofibroma skin, the supposedly healthy skin around neurofibromas and the healthy skin of control subjects. The extensibility at the first and the fifth traction in NF1 patients (neurofibromas and the supposedly healthy skin around it) was significantly different compared to the healthy skin of control subjects. The viscoelastic parameters obtained from the neurofibromas were significantly different in comparison to those obtained from the supposedly healthy skin of NF1 patients and the healthy skin of control subjects. The rheological profiles of the neurofibromas and the apparent healthy skin of NF1 patients demonstrated a hyperextensibility behavior, but in neurofibromas, the skin was unable to return to its initial position at the end of the stretch.

Inguinal hernia: measurement of the biomechanics of the lower abdominal wall and the inguinal canal

BACKGROUND

The stability of the lower abdominal wall may play a considerable role in the development of inguinal hernia. Therefore, the strength of the individual wall layers needs to be quantified. Despite numerous advances in hernia repair, comparatively few systematic biomechanic and morphometric analyses have been performed. Our aim was to establish and apply a standardised procedure for testing the abdominal wall layers' stability.

METHODS

After dissecting the abdominal walls of 16 cadavers into separate layers, we used a spherical punch and a force transducer to investigate the forces necessary to foraminate the layer. In addition, maximum tensile-strength and suction tests and histologic morphometry were performed.

RESULTS

The transversalis fascia was torn up on an average of 10.5 N, the peritoneum including pre- and subperitoneal tissue on 46.6 N, the aponeurosis of obliquus internus abdominis muscle on 51.7 N, and the aponeurosis of obliquus externus abdominis muscle on 92.6 N. Tensile tests of tissue strips obtained from defined areas showed comparable results. In contrast, surgical mesh revealed values between 60 and 150 N in punching tests. Left-right comparisons, as well as comparisons of the individual areas, revealed considerable intra- and inter-individual differences.

CONCLUSIONS

Biological hernia repair should focus on a reinforcement of the tissue layers with the highest biomechanic stability. Reinforcement of the transversal fascia must be questioned according to our results of poor mechanical resistance.

Avaliação histoquímica quantitativa do colágeno na fascia transversalis e na bainha anterior do músculo reto abdominal em doentes com hérnia inguinal

OBJETIVO: Avaliar a participação do colágeno na etiopatogenia das hérnias inguinais, através da análise quantitativa histoquímica do colágeno na bainha anterior do músculo reto abdominal e na fascia transversalis MÉTODO: Foram operados quarenta doentes do sexo masculino, na faixa etária entre 20 e 60 anos, portadores de hérnia inguinal tipo II e IIIA de Nyhus e realizadas autópsias em dez cadáveres frescos, na mesma faixa etária. Em ambos os grupos, amostras da bainha anterior do músculo reto abdominal e da fascia transversalis foram colhidas, coradas pela técnica histoquímica do picrocírius e submetidas a análise morfométrica quantitativa através de sistema computadorizado com a finalidade de identificar possíveis alterações quantitativas do colágeno, em cada um dos dois tipos de hérnias em comparação com indivíduos sem hérnias. RESULTADOS: Encontramos maior concentração do colágeno na bainha anterior do músculo reto abdominal, em comparação a fascia transversalis em todos os grupos estudados, embora esta diferença tenha sido estatisticamente significante apenas no grupo controle. Não encontramos diferenças na concentração do colágeno, na bainha anterior do músculo reto abdominal e na fascia transversalis, entre os doentes com hérnias tipo II e tipo IIIA de Nyhus. Não encontramos diferenças na concentração do colágeno quando comparamos os grupos com hérnias com o grupo controle. CONCLUSÃO: Não encontramos diferenças na quantidade do colágeno na bainha anterior do músculo reto abdominal e na fascia transversalis entre os pacientes portadores de hérnia inguinal tipo II e IIIA de Nyhus em comparação com indivíduos sem hérnias.

Estudo histoquímico das proteoglicanas da fáscia transversal e bainha anterior do músculo reto abdominal em homens adultos, portadores de hérnia inguinal tipo II e IIIA de NYHUS

OBJETIVO: Avaliar, de maneira quantitativa, as proteoglicanas na fáscia transversal e na bainha anterior do músculo reto abdominal de pacientes homens, adultos, portadores de hérnia inguinal tipo II e IIIA de NYHUS. MÉTODO: Foram constituídos três grupos de estudo: um grupo controle, composto por dez cadáveres com óbito até 24 horas e de dois grupos, cada um com vinte pacientes, portadores de hérnias tipo II e IIIA de NYHUS. Foram retiradas amostras da fáscia transversal e da bainha anterior do músculo reto abdominal que foram coradas com Alcian Blue, pH 2,5. As lâminas foram analisadas no programa IMAGELAB de avaliação histológica informatizada. RESULTADOS: Observou-se menor quantidade de proteoglicanas nos pacientes com hérnia inguinal, em relação ao grupo controle. Essa diferença foi estatisticamente significante. CONCLUSÃO: A concentração de proteoglicanas na matriz extracelular está diminuída na fáscia transversal e na bainha anterior do músculo reto abdominal de pacientes homens adultos, portadores de hérnia inguinal tipo II e IIIA de NYHUS, em relação ao grupo controle, constituído por cadáveres não portadores de hérnia inguinal.

Joint mobility in adult patients with groin hernias

The basic mechanisms of hernia formation remain mostly unknown, but several studies suggest that a connective-tissue pathology, affecting mainly the collagen metabolism, could play a role in the genesis of groin hernias. It would be interesting to know if this pathology can express some clinical signs other than the hernia. Our study focused on the joint mobility and the diagnostic criteria for benign joint hypermobility syndrome. Sixty male adult patients with inguinal hernias and 62 control subjects without hernias, age-matched, were compared, taking into account anamnestic criteria (family history of groin hernia, joint sprain, joint dislocation, skin striae, major arthralgia) and joint mobility. This was assessed by using Beighton criteria and measuring the range of movement of five joints (extension of the fifth finger, thumb, wrist, elbow, and knee). The frequency of the positive anamnestic criteria was not statistically different between the two groups. Nevertheless, a family history of groin hernia was observed in 25% of the hernia patients, against 16% in the control subjects ( P=0.23). The mean Beighton score was 0.30 in the hernia patients and 0.29 in the control population. The movement range of the five examined joints was similar in the two groups. In conclusion, patients with a groin hernia presented neither joint hypermobility nor clinical evidence of a benign joint hypermobility syndrome. Although abnormal collagen metabolism is likely implicated in hernia formation, this pathology does not seem to have clinical repercussion on joint mobility.

Quantitative analysis of collagen and elastic fibers in the transversalis fascia in direct and indirect inguinal hernia

PURPOSE

Our previous studies demonstrated structural and quantitative age-related changes of the elastic fibers in transversalis fascia, which may play a role in inguinal hernia formation. To verify whether there were differences in the extracellular matrix between direct and indirect inguinal hernia, we studied the amount of collagen and elastic fibers in the transversalis fascia of 36 male patients with indirect inguinal hernia and 21 with direct inguinal hernia.

MATERIAL AND METHODS

Transversalis fascia fragments were obtained during surgical intervention and underwent histological quantitative analysis of collagen by colorimetry and analysis of elastic fibers by histomorphometry.

RESULTS

We demonstrated significantly lower amounts of collagen and higher amounts of elastic fibers in transversalis fascia from patients with direct inguinal hernia compared to indirect inguinal hernia patients. The transversalis fascia from direct inguinal hernia patients showed structural changes of the mature and elaunin elastic fibers, which are responsible for elasticity, and lower density of oxytalan elastic fibers, which are responsible for resistance. These changes promoted loss of resiliency of the transversalis fascia.

CONCLUSION

These results improve our understanding of the participation of the extracellular matrix in the genesis of direct inguinal hernia, suggesting a relationship with genetic defects of the elastic fiber and collagen synthesis.

Biochemical study of collagen in adult groin hernias

BACKGROUND

Previous works have suggested that a defect in collagen fiber structure may play a role in inguinal hernia formation. These studies focused mainly on the rectus sheath or the skin, while only few reports dealt with the transversalis fascia. According to these findings and to our previous biomechanical and histological studies suggesting that a connective tissue pathology could play a role in the genesis of groin hernias, we performed a biochemical investigation of the collagen in the transversalis fascia and rectus sheath.

MATERIALS AND METHODS

The samples were collected from 40 adult patients with uni- or bilateral hernias and from 20 control subjects without hernia (autopsies and organ donors). A constant area of tissue was taken by using a calibrator. The wet and dry weights per 100 mm(2) were determined and the total collagen concentration as well as its sequential extractibility in NaCl, acetic acid, and pepsin was measured. The ratios of alpha(1)/alpha(2) chains (I) and of type I/III collagen were assessed by polyacrylamide gel electrophoresis.

RESULTS

Samples collected in the control and patient sheaths showed an increased wet weight per 100 mm(2) in the patients. The wet and dry weights per unit area were increased in the patient fascias. The collagen concentration was increased in the indirect hernias. The fascias from the direct hernias (DH) presented a significantly increased collagen extractibility after pepsin digestion (5.6%), when compared to the control fascias (2.6%). The extractibility was 3.4% in the nonherniated (NH) sides. The qualitative study (ratios alpha(1)/alpha(2) (I) and I/III collagen) showed no difference between the fascia groups.

CONCLUSIONS

The significant increase of collagen extractibility with pepsin in the DH fascias and at a lesser degree in the NH fascias suggests that molecular alterations of collagen could be involved in the genesis of groin hernias. This connective tissue pathology would express preferentially its effects in the inguinal region, since we have observed no major difference between the rectus sheaths of controls and those of patients.

[New prospects in the etiology of groin hernias]

AIM OF THE STUDY

To explore new etiological hypotheses of groin hernias, using a biomechanical and histochemical study of the transversalis fascia and of the rectus sheath.

PATIENTS AND METHODS

The samples were collected from 63 patients with uni- or bilateral hernias and from 30 control subjects without hernia. The biomechanical properties were assessed using a computerized-suction device (Cutometer). Sections were stained with hematoxylin and eosin, Masson-trichrome and double-stained with sirius red and orcein.

RESULTS

There was no major biomechanical and histological difference between the control and patient aponeuroses. The patient fasciae from the non-herniated sides presented an increased extensibility and elasticity, as compared with the control fasciae. Those fasciae also showed a collagen framework with disorganized areas and an increased number of isolated fibers.

CONCLUSION

The transversalis fascia from the nonherniated side appears to be a pathological fascia. Therefore, a connective tissue pathology seems to be involved in the genesis of groin hernias, with a preferential manifestation in the inguinal region which affects mainly the collagen fibers.