Abnormal primary tissue collagen composition in the skin of recurrent incisional hernia patients

Recurrence of incisional hernia may be as high as 50 per cent. Abnormal collagen I/III ratios have been observed within scar tissue of patients with recurrent incisional hernias. We sought to determine whether collagen composition in primary, nonscarred tissue was similarly affected in these patients. In this prospective, case-control study, nonscarred, primary abdominal wall skin and fascia biopsies were obtained in 12 patients with a history of recurrent incisional hernias and 11 control subjects without any history of hernia while undergoing abdominal laparoscopic surgery. Tissue protein expression of collagen I and III was assessed by immunohistochemistry followed by densitometry analysis. The collagen I/III ratio in skin biopsies from the recurrent hernia group was significantly less compared with control subjects (0.88 +/- 0.01 versus 0.98 +/- 0.04, respectively, P < 0.05). Fascia biopsies from patients with recurrent hernias was not significantly decreased in collagen I/III ratio compared with control subjects (0.90 +/- 0.04 versus 0.94 +/- 0.03, respectively, P = 0.17). Decreased collagen I/III ratios within the skin of patients with recurrent hernias not involved with scar or healing tissue suggest an underlying collagen composition defect. Such a primary collagen defect, in addition to abnormal scar formation, likely plays a significant role in the pathogenesis of recurrent incisional hernias.     

Abnormal collagen I to III distribution in the skin of patients with incisional hernia

The surgical mesh-free repair of incisional hernias has to face recurrence rates of up to 50%. Apart from technical faults this is probably due to collagen metabolic disorders, known to play an important role in the development of inguinal hernia. In particular an altered ratio of collagen types I and III with an increase in collagen type III has been claimed to reduce the mechanical strength of connective tissues. Therefore, we investigated the content of collagen types I and III in the skin of patients with incisional hernia (n = 7) and recurrent incisional hernia (n = 5) in comparison to controls with healthy skin (n = 7) and normal skin scar (n = 7) both by immunohistochemistry and Western blot analysis. Both immunohistochemistry and Western blot analysis revealed a decrease in the ratio of collagen I/III due to a concomitant increase in collagen III. The patients with incisional hernias and with recurrent incisional hernias showed a ratio of 1.0 +/- 0.1 and 0.8 +/- 0.1, respectively, whereas the controls exhibit a ratio of 2.1 +/- 0.2 in healthy skin and of 1.2 +/- 0.2 in normal skin scar, respectively. The decrease was highly significant (p < 0.01) between the patients with either primary or recurrent hernia and the controls or the normal scar, as well as between controls and normal scar, whereas there was not any significant difference between primary and recurrent hernia (p > 0.05). Our data for the first time confirmed that the presence of incisional hernia is accompanied by impaired collagen synthesis in the skin. The decreased tensile strength of collagen type III may play a key role in the development of incisional hernias. Furthermore, it might explain the high recurrence rates of hernia repair by simple closure, as a repetition of the primarily failing technique, and the improvement by the additional use of alloplastic material.     

BSAVA Manual of Canine and Feline Anaesthesia and Analgesia, 2nd Ed.

The late appearance of incisional hernias several years after laparotomy and the high recurrence rates after operation strongly imply the presence of a disorder of the connective tissue, although a specific defect in patients with incisional hernias has not yet been identified. In the present study we used both immunohistochemistry and Western blot analysis to evaluate the ratio of collagen I and III and the expression of the metalloproteinases (MMP) 1 and 13 in the fascia of patients with incisional or recurrent incisional hernias. Samples of healthy skin or stable skin scar in patients without hernias served as controls. Altogether, our data indicated a significantly decreased ratio of collagen I/III in the fascia of patients with incisional hernias and recurrent incisional hernias. Furthermore, in these patients the expression of MMP-1 was decreased compared to the controls, whereas MMP-13 could not be detected in any fascia sample, with or without hernias present. For the first time, our results give evidence of the existence of a possible collagen disorder in these patients. The decreased ratio of collagen I/III is explainable due to a relative increase of collagen type III, which is known to be characterized by thin fibril diameters and lowered mechanical strength. The altered collagen ratio might be the result of the decreased activity of MMP-1, whereas the absent MMP-13 expression did not seem to modify the scar formation. Thus, our data indicate the presence of collagen metabolic disorders in patients with incisional hernias and recurrent incisional hernias. Furthermore, these results might explain the poor results of a mesh-free hernia repair, which again builds up scar tissue of inadequate collagen composition and strength.     

Collagen I/III and matrix metalloproteinases (MMP) 1 and 13 in the fascia of patients with incisional hernias.

The late appearance ofincisional hernias several years after laparotomy and the high recurrence rates after operation strongly imply the presence of a disorder of the connective tissue, although a specific defect in patients with incisional hernias has not yet been identified. In the present study we used both immunohistochemistry and Western blot analysis to evaluate the ratio of collagen I and III and the expression of the metalloproteinases (MMP) 1 and 13 in the fascia of patients with incisional or recurrent incisional hernias. Samples of healthy skin or stable skin scar in patients without hernias served as controls. Altogether, our data indicated a significantly decreased ratio of collagen I/III in the fascia of patients with incisional hernias and recurrent incisional hernias. Furthermore, in these patients the expression of MMP-1 was decreased compared to the controls, whereas MMP-13 could not be detected in any fascia sample, with or without hernias present. For the first time, our results give evidence of the existence of a possible collagen disorder in these patients. The decreased ratio ofcollagen I/III is explainable due to a relative increase of collagen type III, which is known to be characterized by thin fibril diameters and lowered mechanical strength. The altered collagen ratio might be the result of the decreased activity of MMP-1, whereas the absent MMP-13 expression did not seem to modify the scar formation. Thus, our data indicate the presence of collagen metabolic disorders in patients with incisional hernias and recurrent incisional hernias. Furthermore, these results might explain the poor results of a mesh-free hernia repair, which again builds up scar tissue of inadequate collagen composition and strength.     

Skin as marker for collagen type I/III ratio in abdominal wall fascia

Purpose

An altered collagen metabolism could play an important role in hernia development. This study compared collagen type I/III ratio and organisation between hernia and control patients, and analysed the correlation in collagen type I/III ratio between skin and abdominal wall fascia.

Methods

Collagen organisation was analysed in Haematoxylin–Eosin sections of anterior rectus sheath fascia, and collagen type I/III ratio, by crosspolarisation microscopy, in Sirius-Red sections of skin and anterior rectus sheath fascia, of 19 control, 10 primary inguinal, 10 recurrent inguinal, 13 primary incisional and 8 recurrent incisional hernia patients.

Results

Compared to control patients [7.2 (IQR = 6.8–7.7) and 7.2 (IQR = 5.8–7.9)], collagen type I/III ratio was significantly lower in skin and anterior rectus sheath fascia of primary inguinal [5.2 (IQR = 3.8–6.3) and 4.2 (IQR = 3.8–4.7)], recurrent inguinal [3.2 (IQR = 3.1–3.6) and 3.3 (IQR = 3–3.7)], primary incisional [3.5 (IQR = 3–3.9) and 3.4 (IQR = 3.3–3.6)] and recurrent incisional hernia [3.2 (IQR = 3.1–3.9) and 3.2 (IQR = 2.9–3.2)] patients; also incisional and recurrent inguinal hernia had lower ratio than primary inguinal hernia patients. Furthermore, collagen type I/III ratio was significantly correlated (r = 0.81; P < 0.001) between skin and anterior rectus sheath fascia. Finally, collagen organisation was comparable between hernia and control patients.

Conclusions

Furthermore, in both skin and abdominal wall fascia of hernia patients, collagen type I/III ratio was lower compared to control patients, with more pronounced abnormalities in incisional and recurrent inguinal hernia patients. Importantly, collagen type I/III ratio in skin was representative for that in abdominal wall fascia.     

Analysis of collagen-interacting proteins in patients with incisional hernias

BACKGROUND: In recent years a disorder of the collagen metabolism has been suggested for the pathogenesis of abdominal wall hernias. Previous investigations of skin specimens revealed a reduction in the collagen I/III ratio and alterations in matrix metalloproteinases in patients with incisional hernias. We investigated known collagen-interacting proteins to further characterize connective tissue in these patients. PATIENTS AND METHODS: Skin scars from patients with either primary or recurrent incisional and recurrent inguinal hernias, as a subgroup of incisional hernias, were analyzed for overall collagen content and for the distribution of collagen types I and III by crosspolarization microscopy. The expression of collagen type V, collagen receptor discoidin domain receptor 2, matrix metalloproteinase 1, connective tissue-like growth factor, and tenascin was determined by immunohistochemistry. Mature abdominal skin scars from patients without evident hernia served as controls. RESULTS: Patients with recurrent incisional hernia showed lowest ratios of collagen types I to III. Contents of overall collagen and of collagen type V did not differ between the groups. In patients with either primary or recurrent incisional hernias the proportion of collagen receptor discoidin domain receptor 2 positive cells was increased. Matrix metalloproteinase 1 expression was more pronounced in patients with recurrent incisional or inguinal hernias than in controls. Connective tissue-like growth factor was significantly increased in recurrent inguinal hernia patients. The expression of tenascin was notably decreased in all hernia groups. CONCLUSIONS: The observed alterations in the expression of collagen-interacting proteins again indicate the possibility of a fundamental connective tissue disease as the causal factor in the pathogenesis of (recurrent) incisional hernias.     

增生性瘢痕和瘢痕疙瘩组织中TGF—β1及Ⅰ,Ⅲ型胶原基因 …

目的 检测增生性瘢痕（Ｈ）和瘢痕疙瘩（Ｋ）组织中ＴＧＦ－β１及Ⅰ、Ⅲ型前胶原ｍＲＮＡ的表达,了解其相互关系及意义。方法 斑点杂交分析检测Ｈ和Ｋ组织中Ⅰ、Ⅲ前胶原及ＴＧＦ－β１ｍＲＢＡ稳态水平的改变;原位杂交检测ＴＧＦ－β１ｍＲＮＡ在组织中的空间分布。结果 ①Ｋ和Ｈ组织中ＴＧＦ－β１ｍＲＮＡ稳态水平明显高于Ｎ组和Ｓ组;②Ｋ选择性Ｉ型前胶原ｍＲＮＡ表达增强,而Ｈ组织中Ⅰ、Ⅲ前胶原ｍＲＮＡ表达均增强。     

Modification of collagen formation using supplemented mesh materials

Background Formation of recurrent inguinal and incisional hernia shows an underlying defect in the wound healing process. Even following mesh repair an altered collagen formation and insufficient mesh integration has been found as main reason for recurrences. Therefore the development of bioactive mesh materials to achieve a local modification of the scar formation to improve patients outcome is advisable. Methods Thirty-six male Wistar rats were used within this study. A Mersilene ? mesh sample was implanted after midline skin incision and subcutaneous preparation. Before implantation mesh samples were incubated for 30 minutes with either one of the following agents: doxycycline, TGF-beta 3, zinc-hydrogeneaspartate, ascorbic acid, hyaluronic acid. Incubation with a physiologic 0.9 % NaCl solution served as control. Seven and 90 days after mesh implantation 3 animals from each group (n = 6) were sacrificed for morphological observations. Collagen quantity and quality was analyzed measuring the collagen/protein as well as the collagen type I/III ratio. Results Following an implantation interval of 90 days supplementation with doxycycline (39.3 ± 7.0 μg/mg) and hyaluronic acid (34.4 ± 5.8 μg/mg) were found to have a significantly increased collagen/protein ratio compared to implantation of the pure Mersilene ? mesh samples (28.3 ± 1.9 μg/mg). Furthermore, an overall increase of the collagen type I/III ratio was found in all groups indicating scar maturation over time. However, no significant differences were found after 7 and 90 days of implantation comparing collagen type I/III ratio of supplemented mesh samples and control group. Conclusions In summary, we found an influence of supplemented mesh materials on collagen deposition. However, the investigated bioactive agents with reported influence on wound healing were not associated with an improved quality in scar formation.     

Analysis of c-myc,PAI-1 and uPAR in patients with incisional hernias

BACKGROUND: Disturbed wound healing leading to alterations in collagen composition has been thought to play a key role in the pathogenesis of incisional hernia formation. The aim of the present study was to further characterise the scarring process in such patients. METHODS: Mature skin scars from patients with either primary or recurrent incisional hernias were compared to mature abdominal skin scars from patients without hernias. The distribution of collagen types I and III was analysed using crosspolarisation microscopy. Expression of c-myc-a parameter for cell differentiation and proliferation-and of PAI-1 and uPAR-parameters of the proteolytic cascade in wound healing-were determined by immunohistochemistry. RESULTS: In agreement with previous studies, decreased collagen I/III ratios were found in patients with incisional hernias. In these patients, c-myc levels were significantly elevated whereas plasminogen activator inhibitor-1 (PAI-1) and urokinase-plasminogen activator receptor (uPAR) levels were only slightly increased. In contrast to controls, a significant correlation between c-myc, PAI-1 and uPAR expression and collagen I/III ratios was found in patients with incisional hernias. CONCLUSION: The differential correlation of collagen types and expression of c-myc, PAI-1 and uPAR within the scar tissue might represent a causal factor in incisional hernia formation.     

Improved collagen type I/III ratio at the interface of gentamicin-supplemented polyvinylidenfluoride mesh materials

Background Formation of recurrent inguinal and incisional hernia shows an underlying defect in the wound-healing process with an insufficient quality of scar formation. Even after mesh repair an altered collagen formation and insufficient mesh integration has been found as main reason for recurrences. Therefore, the development of bioactive mesh materials to achieve a local modification of the scar formation to improve patients outcome is advisable. Materials and methods A polyvinylidenfluoride mesh material (PVDF) was constructed and surface modified by plasma-induced graft polymerization of acrylic acid (PVDF + PAAc). Surface supplementation was sought by binding of gentamicin to the provided active sites of the grafted mesh surfaces (PVDF+PAAc+Gentamicin). In vivo modulation of collagen formation was evaluated in a standardized animal model where an abdominal wall replacement was performed in 45 Sprague–Dawley rats. Seven, 21, and 90 days after mesh implantation, collagen/protein ratio and the collagen type I/III ratio as well as the expression of type I alpha 1 collagen mRNA (SYBR Green real-time RT-PCR) were analyzed at the perifilamentary region. Additionally, expression of matrix metalloproteinases (MMP-8/-13) has been investigated immunohistochemically. Results Implantation of the PVDF + PAAc + Gentamicin mesh induced a significantly decreased expression of MMP-8 and MMP-13 at the interface 21 and 90 days after implantation compared to the other groups. Whereas no significant effect was observed comparing the overall collagen/protein ratio, the quality of collagen formation expressed by the collagen type I/III ratio showed significantly higher ratios around the PVDF + PAAc + Gentamicin mesh 21 and 90 days after implantation. Correspondingly, an up to 5.3-fold expression of type I alpha 1 collagen mRNA was found. Conclusion The present data confirm that a surface modification of PVDF mesh samples using plasma-induced graft polymerization of acrylic acid and supplementation of gentamicin is able to improve scar quality and mesh integration.     

Type I and type III procollagen gene expressions in the early phase of ligament healing in rabbits: an in situ hybridization study.

The purpose of this study is to observe type I and type III procollagen gene expressions in the healing ligament using in situ hybridization histochemistry. The rabbit medial collateral ligaments were incised and harvested at 3, 7, 14, and 28 days postoperatively. The healing ligament showed increased expression of both procollagen genes through this period compared with the unoperated ligament. The peak expression level was observed at 7 or 14 days for type I and at 7 days for type III, respectively. The strongest expression of both genes was detected in the scar tissue created between the ends of the old ligament. Although type III procollagen gene expression was observed almost only in the newly created scar tissue, type I procollagen gene was expressed not only in the scar tissue, but also at the ends of the previously normal ligament. These results suggest that type I collagen synthesis begins shortly after ligament injury and occurs at the ends of the injured ligament as well as in the scar tissue, and that type III collagen is largely synthesized in the scar tissue around one week after injury but continues being synthesized for at least four weeks after injury.     

康宁克通对增生性瘢痕Ⅰ,Ⅲ型胶原蛋白及前胶原基因原？…

目的 探讨康宁克通在活体中对增生性瘢痕Ⅰ、Ⅲ型胶原合成及降解影响的机理。方法 用免疫组织化学及分子生物学技术,对６例增生性瘢痕局部注射康宁克通３及７ｄ后,Ⅰ、Ⅲ型胶原蛋白及相应前胶原ｍＲＮＡ的原位表达进行了研究。结果 （１）注射７ｄ后,１型胶原蛋白量降低（Ｐ〈０．０５）,Ⅲ型胶原蛋白量未见明显降低（Ｐ〉０．０５）,而Ⅰ、Ⅲ型前胶原ｍＲＮＡ在注射后３ｄ已被明显抑制（Ｐ〈０．０１）,至注射后７ｄ,表达     

前列腺素E2(PGE2)对瘢痕成纤维细胞Ⅰ、Ⅲ型前胶原基因表达的影响

目的　探索PGE     

重组人转化生长因子β3对成纤维细胞作用的观察

目的　观察重组人转化生长因子 β3(recombinehumantransforminggrowthfactorβ3,rhTGFβ3)对成纤维细胞的作用 ,探讨其可能机制。　 方法　取体外培养的人正常皮肤成纤维细胞(normalskinfibroblast,NSFb)和增生性瘢痕成纤维细胞 (hypertrophicscarfibroblast,HSFb) ,经不同浓度的rhTGFβ3处理 ;另设不含rhTGFβ3的DMEM培养液相应细胞组作为对照。通过放射免疫和Northernblot杂交法 ,观察NSFb和HSFb中Ⅰ、Ⅲ型胶原蛋白及转录水平mRNA表达的变化。　结果　 (1)NSFb和HSFb中Ⅰ、Ⅲ型前胶原的表达有明显不同 ;(2 )与对照组相比 ,经rhTGFβ3处理的各实验组Ⅰ、Ⅲ型前胶原合成明显增加 (P <0 .0 0 1) ,Ⅰ Ⅲ型前胶原的比例变小 ;(3)rhTGFβ3对NSFb和HSFb生物学作用的影响呈明显的量效关系。在相同剂量作用下 ,HSFb的PCⅠ、PCⅢ含量高于NSFb。　结论　rhTGFβ3能有效提高成纤维细胞中Ⅰ、Ⅲ型胶原的合成和Ⅰ、Ⅲ型构成比中Ⅲ型胶原的相对含量 ,可能对加速创面愈合及减少瘢痕形成具有重要的作用     

Increases in type III collagen gene expression and protein synthesis in patients with inguinal hernias.

OBJECTIVE: The aim of this study was to determine if alterations in fibrillar collagen synthesis were associated with the development of inguinal hernias. SUMMARY BACKGROUND DATA: Previous work has suggested that alterations in connective tissue accumulation may play a functional role in the development of inguinal hernias. In particular, several investigators have suggested that alterations in collagen synthesis, causally related to connective disorders such as osteogenesis imperfecta, may also be responsible for the inguinal herniation that is markedly increased in such patients. This study was undertaken therefore to study collagen synthesis in patients with inguinal hernia in the absence of any other connective tissue disease. METHODS: Skin fibroblasts from 9 patients with hernias and 15 control individuals were radiolabeled with 3H-proline. Trypsin-chymotrypsin-resistant type I and III collagens were isolated and analyzed by sodium dodecyl sulfate polyacrylamide gel electrophoresis, and recovery was quantified by laser densitometry. Steady-state levels of alpha 1(I) and alpha 1(III) procollagen mRNAs were also determined by northern and slot-blot hybridization analysis. RESULTS: The alpha 1(I)/alpha 1(III) collagen ratios were shown to be 6.3 +/- 0.34 in fibroblasts from control individuals and 3.0 +/- 0.25 in fibroblasts from patients with inguinal hernias. This statistically significant difference (p < 0.0001) was caused by an increase in the secretion of alpha 1(III) procollagen from the fibroblasts of patients with hernias. A concomitant increase in the steady-state levels of alpha 1(III) procollagen mRNA was observed in total RNA isolated from the patients' fibroblasts. CONCLUSIONS: A constitutive and systemic increase in type III collagen synthesis may result in reduced collagen fibril assembly in the abdominal wall, eventually leading to the development of herniation. Although it is not yet clear what genetic factors are responsible for the elevation in type III collagen synthesis in patients with hernias, this study represents the first attempt to define individuals with an abnormality in collagen production that may be specifically related to herniation. A clearer understanding of the possible genetic factors that influence the pathophysiology of this disease will be important to improve the treatment of patients in whom inguinal hernias develop.     

Effect of Sucrose on Collagen Metabolism in Keloid, Hypertrophic Scar, and Granulation Tissue Fibroblast Cultures

Sucrose has been used to treat wounds with excellent results and with minimal abnormal scarring. In this study the effects of sucrose on collagen metabolism in fibroblast culture was evaluated. Sucrose (5.5, 15, or 25 mM) was added to granulation tissue, hypertrophic scar, and keloid fibroblast cultures. mRNA levels and procollagen aminopropeptides for type I and III collagens in cell culture medium were studied. Sucrose decreased mRNA levels for proα1(I) and proα1(III) collagens in fibroblast cultures derived from hypertrophic scar and keloid. In normal granulation tissue fibroblast cultures, 5.5 mM sucrose increased mRNA levels for proα1(I) and proα1(III) collagen, and higher concentrations decreased them. The synthesis of type I collagen decreased dose-dependently in all cell strains, whereas the synthesis of type III collagen decreased only in granulation tissue fibroblasts. To conclude, in vitro high concentrations of sucrose down-regulate both collagen gene expression and synthesis in normal granulation tissue fibroblasts, whereas in fibroblasts derived from abnormal scar sucrose down-regulates only type I collagen gene expression and synthesis, changing the pattern of collagen metabolism toward normal.     

Decreased collagen type I/III ratio in patients with recurring hernia after implantation of alloplastic prostheses

Background Abnormal collagen metabolism is suspected to play an important role in the pathogenesis of recurring inguinal and incisional hernias. Whereas alloplastic prostheses are nowadays routinely used, the quantity and quality of collagen formation after repair in humans has not been analysed in a large cohort.Method Seventy-eight prostheses (Prolene, Atrium, Marlex, Vypro, Mersilene, Gore-Tex) implanted for inguinal and incisional hernia repair were explanted because of recurrence, chronic pain or infection. The mean implantation period was 17.9±11.2 (range 0.5–48) months. Collagen formation was investigated quantitatively (collagen–protein ratio) and qualitatively (collagen type I/III ratio). Results were related to clinical data that included gender, age, implantation period, indication for implantation/explantation, type and location of prosthesis.Results Mean collagen–protein ratio was 45.3±8.5 g/mg, with significant differences between male (43.8±9.1 g/mg) and female tissue samples (48.1±6.8 g/mg, P=0.033). The mean collagen type I/III ratio of all samples investigated was 2.1±1.4. Samples explanted for recurring hernias exhibited a significantly decreased ratio (1.3±0.7, P<0.05) compared to samples explanted because of pain (3.4±1.2) or infection (2.9±1.6). Multivariate analysis excluded independent effects of age, gender, indication for implantation of prostheses, location and implantation period on collagen type I/III ratio.Conclusion The present study confirms the importance of a biological approach, next to technical aspects, to the understanding of the pathogenesis of recurrent hernia formation and underscores the presence of a disturbed scarring process. The composition of scar tissue with a lowered collagen type I/III ratio and, therefore, reduced tensile strength may be a major contribution to hernia recurrence.