HERNIAS AS A COLLAGEN MATURATION DEFECT

On the Nature of Stationary and Time-Resolved Fluorescence Spectroscopy of Collagen Powder from Bovine Achilles Tendon

This paper presents a more systematic study of steady-state and time-resolved autofluorescence spectroscopy of collagen isolated from bovine Achilles tendon. In steady-state fluorescence measurements, the excitation and emission spectra of collagen powder, recorded at different fluorescence excitation and detection wavelengths, were compared with the fluorescence excitation and emission spectra of the amino acids phenylalanine, tyrosine, and tryptophan, as well as with similar spectra for 13 autofluorescent collagen cross-links, which have been identified and described in the literature so far. In time-resolved studies, fluorescence was excited by the pulsed light of different wavelengths, and for each excitation wavelength, fluorescence decay was recorded for several detection wavelengths. Data analysis allowed recovery of the fluorescence decay times for each experimental excitation detection event. The obtained information on the decay times of the measured fluorescent signals was discussed, taking into account the available literature data from similar studies of isolated collagen and collagen-rich tissues. Based on the obtained results, it was found that the shape and position of the measured fluorescence excitation and emission spectra of collagen strongly depend on the emission and excitation wavelengths selected in the measurements. From the recorded excitation and emission bands of collagen, it can be concluded with high probability that there are additional, so far unidentified, collagen cross-links, which can be excited at longer excitation wavelengths. In addition, the collagen excitation spectra were measured at longer emission wavelengths at which the collagen cross-links emit fluorescent light. In addition to the emission spectra obtained for excitation in the deep-UV region, the results of time-resolved fluorescence studies with excitation in the deep-UV region and detection at longer wavelengths suggest that fluorescence excitation energy transfer processes occur from the amino acids to the collagen cross-links, and also between the cross-links themselves.

Evaluation of Ultrasound-guided Genitofemoral Nerve Block Combined with Ilioinguinal/iliohypogastric Nerve Block during Inguinal Hernia Repair in the Elderly

To evaluate the anesthetic effect of ultrasound-guided (USG) ilioinguinal/iliohypogastric nerve (II/IHN) block combined with genital branch of genitofemoral nerve (GFN) block in the elderly undergoing inguinal hernia repair, 54 old patients (aged 60-96years, ASA I-III) with indirect hernia were enrolled and scheduled for unilateral tension-free herniorrhaphy. Patients were grouped randomly to receive either USG II/IHN plus GFN block (Group G) or USG II/IHN block alone (Group I). The intraoperative visual analogue scale (VAS) scores were recorded at skin incision, at spermatic cord/round ligament traction and at sac ligation. The resting and dynamic VAS scores were recorded postoperatively. The requirements of extra sedatives and analgesics for intra- and postoperative analgesia were assessed. Occurrence of complications of the block, postoperative nausea and vomiting and femoral nerve palsy was also reported. Both groups showed similar sensory block. When stretching spermatic cord/round ligament, the patients in group G had significantly lower VAS scores than in group I. And group G used much fewer adjuvant sedatives and analgesics to achieve adequate anaesthesia. In addition, group G was presented with better intraoperative anaesthesia and lower postoperative dynamic VAS scores at all time points tested. No significant difference was found in the postoperative requirement of rescue medication. Both groups showed no complications related to the block and group G reported no femoral nerve palsy. The addition of GFN block to II/IHN block improves the quality of perioperative anesthesia and analgesia in the elderly and reduces the consumption of extra sedatives and analgesics during the surgery.

Tamoxifen induces the development of hernia in mice by activating MMP-2 and MMP-13 expression

Hernia is a disease with defects in collagen synthesis/metabolism. However, the underlying mechanisms for hernia formation have not been fully defined. Tamoxifen is a selective estrogen receptor modulator and used for patients with breast cancer. Tamoxifen also has pleiotropic and side effects. Herein, we report that tamoxifen treatment resulted in an appearance of a large bulge in the low abdomen between the hind legs in male but not in female mice. The autopsy demonstrated that the low abdominal wall was broken and a large amount of intestine herniated out of the abdominal cavity. Histological analysis indicated that tamoxifen caused structural abnormalities in the low abdominal wall which were associated with decreased type II collagen content. Furthermore, we determined increased matrix metalloproteinase-2 (MMP-2) and MMP-13 expression in the tissue. In vitro, tamoxifen induced MMP-2 and MMP-13 expression in fibroblasts. The promoter activity analysis and ChIP assay demonstrate that induction of MMP-13 expression was associated with activation of JNK-AP-1 and ERK1/2 signaling pathways while induction of MMP-2 expression was related to activation of the ERK1/2 signaling pathway. Taken together, our study establishes a novel murine hernia model, defines a severe side effect of tamoxifen, and suggests a caution to male patients receiving tamoxifen treatment.

[Historic analysis of complex incisional hernia: to an understanding of the double prosthetic repair technique]

The treatment of complex incisional hernias is, on occasions, a real social and professional, and still controversial, challenge. A multitude of techniques have been described over the years in an attempt to solve this problem. The social context and technological development of each period are essential to understand the continuous changes in the way of performing these techniques. This article caries out an historical review of the prosthetic treatment of incisional hernias, trying to understand and apply the basic principles of the treatment of all incisional hernias to the repair with a double mesh.

Are collagens the culprits in the development of incisional and inguinal hernia disease?

Incidence curves for the development of inguinal hernia disease and recurrences thereof exhibit a linear rise over the years and therefore suggest multi-factorial underlying causes. Several studies have revealed marked changes in the abundance and composition of interstitial collagens in patients with (recurrent) hernia diseases, adult groin hernia and incisional hernia. These observations led to the hypothesis that hernia formation and the recurrence of incisional hernia may be explained by disordered tissue renewal and by abnormal wound healing, respectively. Interstitial collagens, owing to their long half-lives and biomechanical strength, are most likely critical components of the biological system of tissue remodelling. An overview of the literature is provided, and the consequences for surgical practice are discussed.

The unified theory of hernia formation

The perusal of surgical journals suggests that the etiology and the treatment of hernias are still based on the understanding of a simple mechanical defect, an idiopathic happenstance requiring a reliable hernia repair, preferably with a prosthetic mesh or device. The need for additional elucidation does not constitute an aim that is pervasive in the surgical community or with the corporate manufacturers of surgical implements. This may well be because surgeons are not trained scientists and laboratory workers. Fortunately, several disciplines are injecting a healthy dose of curiosity matched by ingenuity. Among these contributors, we can count anatomists, electron microscopists, biochemists, organic chemists, pathologists, geneticists, and molecular biologists, who have looked at collagen, enzymes, tobacco smoke, congenital diseases, and chromosomal defects. Every aspect of the researchers' work has identified and converged onto a final common organ: collagen. It is the pathological changes in collagen that set the stage for the development of a hernia. The multiple theories on mechanisms of hernia formation have, at last, melded into one single Unified Theory of hernia formation.

Milestones in the history of hernia surgery: prosthetic repair

Billroth (1878) envisaged prostheses before Bassini's sutured cure (1887). Phelps (1894) reinforced with silver coils. Metals were replaced by plastic (Aquaviva 1944). Polypropylene (Usher 1962), resisting infection, became popular. Usher instituted tensionless, overlapping preperitoneal repair. Spermatic cord was parietalized, to obviate keyholing. Stoppa (1969) championed the sutureless Cheatle-Henry approach encasing the peritoneum. His technique, "La grande prosthese de renforcement du sac visceral" (GPRVS), was adopted by laparoscopists. Newman (1980) and Lichtenstein (1986) pioneered subaponeurotic positioning. Kelly (1898) inserted a plug into the femoral canal; Lichtenstein and Shore (1974) followed. Gilbert (1987) plugged the internal ring, and Robbins and Rutkow (1993) treated all groin herniae thus. Incisional herniation has been controlled by prefascial, retrorectus prosthetic placement (Rives-Flament 1973). ePTFE (Sher et al. 1980) is useful intraperitoneally, since it evokes few adhesions. Here, laparoscopy (Ger 1982) is competitive. Beginning in 1964 (Wirtschafter and Bentley), experimental and clinical studies have shown herniation may be associated with aging and genetic or acquired (smoking, etc.) systemic disease of connective tissue. These data, with prospective trials, all but mandate tensionless prosthetic repair.

Defective collagen metabolism in Saudi patients with hernia

Fibroblastic cell cultures were derived from the hernial sac and some of the surrounding muscles (rectus sheath, internal oblique, and/or cremasteric muscle) of 130 Saudi patients with different types of herniation, and from 21 control subjects. The rates of cell proliferation were studied for 39 days. Results suggested decreased rates of proliferation of cells derived from patients compared to controls. In vitro studies of the rates of incorporation of 14C proline into the muscle biopsies revealed decreased rates of label incorporation in the samples derived from patients compared to controls. However, no differences were detected between rates of collagenase activities of the biopsies obtained from patients compared to those of controls. These findings suggest that collagen synthesis is probably defective in the studied group of Saudi patients with hernia.

Etiology and biomechanics of hernial sac formation

This paper, to the authors' best knowledge, presents the first attempt on the understanding of the biomechanics of hernial sac formation. First, a brief survey of the selected etiological factors and their related theories on hernia is given. Next, the results of some preliminary tensile tests conducted on normal and sac peritoneum are discussed. The third part of the paper is concerned with a theoretical model which incorporates both material and geometric nonlinearities by considering deformation of circular membrane under internal fluid pressure. The influence of the material properties of the peritoneal sac, its thickness and its initial radius of curvature, as well as the internal fluid pressure on the growth of the sac are illustrated. The existence of a critical value for a non-dimensional parameter is shown and it is proposed that the herniation process can be viewed as a biomechanically unstable phenomenon in the light of the present model.

Subcutaneous extraperitoneal repair of ventral hernias: a biological basis for fascial transplantation

Two fundamental biological differences between normal fascia and scar tissue are rate of collagen turnover and physical weave of collagen subunits. Both factors account for unsatisfactory results following ventral hernia repair unless scar tissue is excised and normal fiscia used. Removal of scar and identification of normal fascia often require extensive dissection, entrance into the peritoneal cavity, and sometimes requires lysis of intestinal adhesions with occasional injury to bowel. Simple imbrication of the hernia sac, as in treatment of a direct inguinal hernia, without excision usually results in recurrence of the hernia because of remodeling and attenuation of scar tissue. A new procedure, based upon the technique of direct inguinal hernia repair without opening peritoneum, has been performed on 12 patients with large ventral hernias. The procedures, performed entirely in a subcutaneous plane, involves imbrication of scar, transfer of a massive fascial onlay graft, and use of an internal stent. Patients have been followed for one to 5 years; there have been no recurrences. Inductive influence of the fascial transplant has been measured in two patients; a tenfold increase in net collagen synthesis and deposition occurs for at least one year following transplantation of fascia to an imbricated scar recipient area.

Physiopathologic aspects of scleral stress-strain

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