Recurrent Incisional Hernia Research Articles

The use of mesh and collagen in incisional hernias

Dear Editor We read with much interest the article by Vidovic et al., titled “Factors aVecting recurrence after incisional hernia repair [1]”. We fully agree with the authors’ conclusion that it is important to become familiar with the risk factors for recurrence of incisional hernia to eliminate or decrease recurrence, but we have a few remarks concerning the article. The authors claim that the routine use of synthetic mesh is not justiWed because of its potential for complications, and that the results of sutured repair of small to medium-sized hernias are satisfactory. However, according to a well-conducted randomized controlled trial that compared suture versus mesh repair of incisional hernia in patients with a primary or Wrst-time recurrent incisional hernia, the conclusion was that the routine use of mesh is superior to suture repair for both small and large incisional hernias, and the use of mesh repair results in lower recurrence rates. Mesh reduces the morbidity and costs associated with incisional hernias. In patients with small incisional hernias, the recurrence rates were 67% after suture repair and 17% after mesh repair (P = 0.003). Hence, concerning the potential for complications in the mesh repair group, 17% had a complication, compared with 8% in the suture repair group (P = 0.17), not a statistically signiWcant diVerence [2]. The authors also did not discuss collagen metabolism disorders in hernia patients. Collagen disorders play an important role in the development of inguinal hernia [3]; impaired proportions result in tissue alterations, and are one of the factors that lead to hernia formation. Collagen plays an important role in the pathogenesis of incisional hernias and is not mentioned. A recent study, conducted in our department, comparing the qualitative and quantitative aspects of total and types I and III collagen samples of linea alba aponeurosis in patients with hernias on the anterior abdominal wall, including incisional ones, and from cadavers without hernias, showed that individuals with hernia have a small amount of total and type I collagen. The amount of total collagen was 18.05% smaller and type I collagen was 20.50% smaller in patients with hernias (P < 0.05) [4]. The results of these and other studies [5] indicate a relationship between incisional hernias and collagen disorder. In the evaluations of incisional hernia repair we should never forget the important role of collagen imbalance in the pathophysiology of hernia formation. The use of mesh should be increasingly encouraged to avoid unnecessarily high rates of recurrence.

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.

Incisional hernia: challenge of re-operations after mesh repair

The widespread use of meshes for the repair of incisional hernia is currently followed by an increasing number of re-operations. The incidence of incisional hernia recurrence after mesh repair varies between 3 and 32%. The problem of mesh failure and options for another surgical intervention seem rather unattended. We present our experience of 77 re-operations after previous mesh repair that were performed between 1995 and 2004 out of a total of 1,070 operations for incisional hernia. The retrospective analysis focused on recurrence in relation to location, material of the previous mesh repair and the surgical procedure to resolve the problem. The locations of the preceding meshes were epifascial as onlays (n=23), retromuscular as sublays (n=46), within the defect as inlays (n=6) or intraperitoneally (n=2). The direction of the incision was vertical medial (n=41) or horizontal crossing the linea semilunaris (n=36). Recurrences after median incisional hernia mesh repair mainly occurred at the cranial border of the mesh subxiphoidal. Except for two patients, all recurrences manifested at the margin of the enclosed mesh. Re-operation after previous mesh repair is a surgical challenge. The type of revision procedure has to consider the position and material of the previous mesh. In our clinic recurrences, heavyweight polypropylene meshes were mostly treated with mesh exchange and lightweight polypropylene meshes could be treated by extension with a second mesh. In contrast to suture techniques, deficient mesh repairs are more evidently related to technical problems.

Obesity-Related Factors in the Repair and Healing of Recurrent Incisional Hernia: A Summary of Risk Factors and Perioperative Strategies

Recurrent incisional hernias are a clinical and surgical challenge in obese patients. In addition to tension on the repair created by abdominal girth, poor wound healing and immobility also contribute to recurrence in these patients. Specific postoperative nursing care strategies to prevent complications in complex hernia repairs are discussed. Surgical considerations including concomitant repair of hernia with bariatric surgery, panniculectomy, and individual care planning are also discussed.

Factors affecting recurrence after incisional hernia repair

Incisional hernias occur primarily as a result of high tension and inadequate healing of a previous incision, the latter of which is frequently related to infection at the surgical site. Despite recent advances in operative techniques, the recurrence rate remains unacceptably high. To evaluate the impact of different predisposing factors for the recurrence of incisional hernia, we reviewed retrospectively the medical records of 297 patients who had undergone incisional herniorrhaphy (188 tissue repairs, 109 mesh repairs) in our hospital. Demographic data (age and gender), type of repair, body mass index, hernia size, presence of chronic illnesses and wound complications were evaluated in a univariate and multivariate manner analysis. The overall recurrence rate was 30.3%, with the recurrence rate in patients who underwent tissue repair being 39.4% and that in patients following prosthetic repair 14.6%. The recurrence rate was significantly influenced by type of repair, obesity, hernia size, wound healing disorders and some chronic comorbidities. We conclude that it is necessary to become familiar with the risk factors for recurrence of incisional hernia in order to eliminate or decrease their effect on the positive outcome of incisional herniorrhaphy.

Preliminary results of a two-layered prosthetic repair for recurrent inguinal and ventral hernias combining open and laparoscopic techniques

The use of prosthetic mesh has become the standard of care in the management of hernias because of its association with a low rate of recurrence. However, despite its use, recurrence rates of 1% have been reported in primary inguinal repair and rates as high as 15% with ventral hernia repair. When dealing with difficult recurrent hernias, the two-layer prosthetic repair technique is a good option. In the event of incarcerated or strangulated hernias, however; placement of prosthetic material is controversial due to the increased risk of infection. The same is true when hernia repairs are performed concurrently with potentially contaminated procedures such as cholecystectomy, appendectomy, or colectomy. The purpose of this study is to report our preliminary results on the treatment of recurrent hernias by combining laparoscopic and open techniques to construct a two-layered prosthetic repair using a four ply mesh of porcine small intestine submucosa (Surgisis, Cook Surgical, Bloomington, IN, USA) in a potentially infected field and a combination of polypropylene and ePTFE (Gore-Tex, W.L. Gore and Associates, Flagstaff, AZ, USA) in a clean field. From September 2002 to January 2004, nine patients (three males and six females) underwent laparoscopic and open placement of surgisis mesh in a two layered fashion for either recurrent incisional or inguinal hernias in a contaminated field. A total of eight recurrent hernia repairs were performed (five incisional, three inguinal) and one abdominal wall repair after resection of a metastatic tumor following open colectomy for colon carcinoma. Six procedures were performed in a potentially contaminated field (incarcerated or strangulated bowel within the hernia), two procedures were performed in a contaminated field because of infected polypropylene mesh, and one was in a clean field. Mean patient age was 56.4 years. The average operating time was 156.8 min. Operative findings included seven incarcerated hernias (four incisional and three inguinal), one strangulated inguinal hernia, and one ventral defect after resection of an abdominal wall metastasis for a previous colon cancer resection. In two of the cases, there was an abscess of a previously placed polypropylene mesh. All procedures were completed with two layers of mesh (eight cases with surgisis and one with combination of polypropylene/ePTFE). Median follow up was 10 months. Complications included two seromas, one urinary tract infection, two cases of atelectasis and one prolonged ileus. There were no wound infections. The average postoperative length of stay was 7.8 days. There have been no mesh-related complications or recurrent hernias in our early postoperative follow-up period. The use of a new prosthetic device in infected or potentially infected fields, and the two-layered approach shows promising results. This is encouraging and provides an alternative approach for the management of difficult, recurrent hernias.

Rives-Stoppa retromuscular repair for incisional hernias

Background: Incisional hernias are a prevalent problem in abdominal surgery and occur in 11% of patients who undergo laparotomy. Primary suture closure of an incisional hernia results in a 31- 58% recurrence and the addition of a prosthetic mesh implant decreases recurrence rates to 8%-10%. Popularized in Europe by Rives and Stoppa, the sublay technique has proven to be very effective with low recurrence rates (0-23%) and minimal complications. The purpose of the study was to evaluate the experience of a single surgeon at a large tertiary care center performing a modified Rives-Stoppa repair for abdominal incisional hernias. Materials & Methods: The records of all patients undergoing a modified Rives-Stoppa incisional hernia repair between January 2000 and August 2003 were retrospectively reviewed. Outpatient clinic notes, discharge summaries, operative reports, and laboratory data were reviewed for patient demographics, surgical data and postoperative complications. All data was collected with previous written consent of the patient and approval by the hospital institutional review board. Statistical analysis was conducted using SPSS for Windows. Results: During the study period, 83 patients underwent a modified Rives-Stoppa incisional hernia repair. Nineteen patients were excluded due to incomplete medical records. The majority of incisional hernias were midline and supraumbilical, with several (n=3) flank hernias. Forty-five percent (n=29) of the incisional hernias were recurrent (mean 2, range 1-7, S.D.± 1.6). No patient required postoperative exploration for an intra-abdominal catastrophe. Follow-up information was available for 61 patients, with mean follow-up of 20 weeks (range 1-144 weeks, S.D.± 30.1) and mean number of follow-up visits of three (range 1-13, S.D. ± 2.9). Twenty-five percent (n=16) of patients had a complication as a result of the hernia repair. Six patients (9.4%) had superficial wound or deep mesh infections. None required removal of the prosthetic mesh and were successfully managed with antibiotics and/or drainage. One patient suffered a reaction to staples, four (6.3%) developed seromas, and three developed (4.7%) hematomas. Four patients (6.3%) were noted to have early postoperative small bowel obstructions and all of these were successfully managed conservatively. Only two patients (3.1%) developed recurrent incisional hernias. Conclusions: The results presented here confirm that the modified Rives-Stoppa retromuscular repair is an effective method for the repair of incisional hernias. The complication and recurrence rates compare favorably to published results for alternative techniques.

Biomaterial-dependent MMP-2 expression in fibroblasts from patients with recurrent incisional hernias

With regard to the pathogenesis of recurrent incisional hernia, an impaired connective tissue quality leading to an aberrant scarring process has been proposed. For the matrix metalloproteinase (MMP-2) a pathogenetic involvement in direct inguinal hernia development is reported. With mesh implantation as the gold standard treatment for incisional hernias, the aim of the present study was to investigate the MMP-2 expression in patients with recurrent incisional hernias with and without mesh-materials. In primary fibroblast cultures obtained from skin scars in patients with and without recurrent incisional hernias, MMP-2 synthesis and gene expression were investigated. Furthermore, MMP-2 synthesis and gene expression of fibroblasts were compared after incubation with two different mesh materials: polypropylene and absorbable polyglactin filaments. MMP-2 enzyme activity was determined by semiquantitative zymography and mRNA synthesis by quantitative RT-PCR. Both MMP-2 enzyme activity and mRNA expression were similar in hernia and control fibroblasts in vitro. In control fibroblasts mesh incubation did not significantly affect MMP-2 expression, whereas polypropylene mesh contact of fibroblasts from patients with recurrent incisional hernias led to a major decrease of MMP-2 activity and of mRNA expression. In the absence of biomaterials fibroblasts from recurrent incisional hernia, patients have no alterations of their MMP-2 synthesis compared to control fibroblasts, whereas a specific response was found after biomaterial contact hereby indicating differences in fibroblast phenotype.

Presentation and outcome of strangulated external hernia in a district general hospital.

Two hundred consecutive emergency hernia operations are reviewed. Mortality from this condition has not significantly altered in the past 30 years. Half of the patients presented 48 h or more from the onset of symptoms. Mortality and bowel resection were clearly linked with the duration of symptoms prior to admission. There were no reliable clinical signs to predict the likelihood of bowel strangulation. Recurrent incisional and femoral hernias were associated with high resection rates and mortality. Right-sided hernias appeared to strangulate more frequently than left-sided hernias.

Use of the Omentum Flap as Additional Soft-Tissue Cover for Abdominal Wall Defects Reconstructed with Gore-Tex

Use of alloplastic materials such as Gore-Tex and locoregional flaps for reconstruction of large abdominal wall defects has been well described. The purpose of this article is to present a novel technique of using the omentum as an interpositional flap to protect the Gore-Tex repair of the abdominal wall. Four patients with large abdominal wall defects underwent reconstruction with Gore-Tex and omentum flap. These defects resulted from tumor resection and recurrent incisional hernia. Their dimensions ranged from 15 x 10 cm to 25 x 27 cm. The Gore-Tex patch was inset using an underlay technique. The omentum was tunneled through a separate opening in the abdominal wall into the subcutaneous plane and used to cover the Gore-Tex. Skin coverage was accomplished by direct closure or myocutaneous flaps. The mean follow-up was 17 months. All wounds healed, with no hernias. One patient developed a subcutaneous abscess 6 months postoperatively, and this was treated successfully by percutaneous drainage, as the omentum had walled-off the abscess. The omentum flap served as an additional soft-tissue cover over the Gore-Tex repair to prevent exposure in the event of infection or flap breakdown. This technique is useful in situations in which delayed wound healing is anticipated or when large quantities of prosthetic material are used.

One year results of a randomised controlled multi-centre study comparing Prolene and Vypro II-mesh in Lichtenstein hernioplasty

A standard polypropylene mesh used in Lichtenstein's operation induces a strong foreign tissue reaction with potential harmful effects. A mesh with less polypropylene could possibly be beneficial. Six hundred men with primary unilateral inguinal hernias were randomised to Lichtenstein's operation using a Prolene- or Vypro II-mesh in six centres. The patients were blinded to which mesh they received. A validated questionnaire assessing recurrence and pain along with SF-36 Health Survey was sent after 1 year to all patients and a selected group was clinically examined. Of the 591 operated patients, 526 (89.0%) returned the questionnaire. 188 patients had some complaints or sensations of which 111 patients were clinically examined. The mean follow-up time was 13.6 (SD. 4.0) months. The incidence of hernia recurrence (four vs. four patients) and neuralgia (three vs. four patients) did not differ between Prolene and Vypro II-groups, respectively. One Vypro II-patient was re-operated due to neuralgia. There was no difference in the SF-36 scores. The results of Lichtenstein's operation with either Prolene or Vypro II do not seem to differ significantly.

Incisional hernia—comparison of mesh repair with Cardiff repair: an university hospital experience

Incisional hernia is a frequent complication of abdominal surgery. Various types of repair are recommended for incisional hernia. Suture and mesh repair are compared in the present study. One hundred seventy one patients with incisional hernia underwent Cardiff repair (far and near sutures with reinforcement sutures) which was used as an open suture repair while onlay polypropylene mesh was used in the mesh repair technique. Cardiff repair was performed in 116 patients with no mortality with recurrence in two patients with mean follow up of 7.1 years. Both these patients with recurrence had a defect measuring more than 10 cm in width. Mesh repair was carried out in 55 patients with no recurrence in mean follow up of 37 months. Seroma formation was noted in 7 (12.72%) with mesh repair as compared to 4 (3.44%) patients with Cardiff repair. We recommend Cardiff repair for primary and small to medium size incisional hernias. Onlay polypropylene mesh is ideal for tension-free hernia repair, recurrent incisional hernia and hernia defects wider than 10 cm.

Subxiphoid Incisional Hernias after Median Sternotomy

Subxiphoid hernias are difficult to repair. This study attempts to identify risk factors associated with incisional hernia formation after median sternotomy. A retrospective review was conducted on patients undergoing subxiphoid incisional hernia repair between 1995 and 2002. The study group was compared with a group undergoing similar cardiothoracic procedures as to body mass index (BMI), comorbidities, complications, tobacco use, length of stay, ICU stay, bypass time, transfusion requirements, and wound infections. Statistical analysis utilized Student's t-test, chi-square, and Kaplan-Meier analysis. A total of 117 subxiphoid hernias were repaired; 45 were used for comparison with a matched cohort of 79 patients. Average time between sternotomy and hernia repair was 24.3 months (+/-16.8) with 22 (49%) patients developing hernias within 2 years. Mean followup was 48 months. The study group differed significantly from the nonhernia group in age (56.6 +/- 13.0 versus 62.2 +/- 8.9, p = 0.01), mean length of stay (16.3 +/- 22.8 versus 10.2 +/- 6.7, p = 0.03), BMI (29.6 +/- 4.5 versus 27.2 +/- 4.5, p = 0.01), number of transplantation patients (10 versus 1, p = 0.0003), and presence of sternal wound infection (18% versus 3.9%, p = 0.02). Multivariate analysis revealed significance in regard to transfusion requirements (p = 0.015) and approached statistical significance with BMI (p = 0.058). Of the 45 patients undergoing hernia repair, 31(69%) had a mesh repair and 10 (32%) patients recurred. Six (43%) patients without a mesh repair recurred. Seventy-five percent of the patients with sternal wound infections developed recurrent hernias. Transfusion requirements, BMI, and sternal wound infections might be associated with subxiphoid hernias after median sternotomy. Sternal wound infection increases the risk of recurrent incisional hernia.

Component separation technique to repair large midline hernias

In patients with omphalocele, several different techniques are performed for repair of the abdominal wall defect. We present the case of a staged abdominal closure of a giant incisional hernia after repair of a ruptured omphalocele. At birth, skin flap coverage associated with silo formation occurred, but the abdominal wall defect remained, resulting in a giant abdominal hernia. To expand the layers of the abdominal wall, tissue expanders were placed between the bilateral internal oblique and transverses abdominis muscles. Postoperatively, a modified components separation technique was performed. The abdominal wall was closed in the midline. Upon closure of the skin in the midline, bilateral relaxing incisions were performed, covering the remaining defect with artificial dermis. At the age of one year and 7 months, the patient had no recurrent incisional hernia nor any wound complications.

Incisional Hernioplasty with Extraperitoneal Onlay Polyester Mesh

Recurrent incisional hernia remains a major problem for the general surgeon. The high recurrence rate of incisional hernias after primary closure by tissue approximation led to the development of tension-free procedures using prosthetic materials. The goal of this study is to present the results of an extraperitoneal tension-free technique using a polyester mesh (Mersilene). A total of 43 patients with incisional hernias were surgically treated during a 9-year period in our department. Twenty-four patients (56%) had recurrent incisional hernias, 21 had primary repair by tissue approximation, and 3 had prolene mesh tension-free repair with wound infection. Patients' mean age was 68.2 years, and the mean postoperative follow-up was 54.4 months. Immediate postoperative complications were noticed in 9 patients (21%) subcutaneous seroma in 6 (14%) and wound infection in 3 (7%). Recurrence was noticed in 4 patients (9%) during the first 9 postoperative months. Late minor complications such as restriction of abdominal wall motility and chronic pain was noticed in 3 (7%) patients. In conclusion, the extraperitoneal onlay tension-free incisional hernia repair using polyester mesh is an easy and safe procedure with no major morbidity or recurrence rate.

The prevention of incisional hernia formation using a delayed-release polymer of basic fibroblast growth factor.

We sought to reduce the high incidence of abdominal wall incisional hernias using sustained release growth factor therapy. Incisional hernias complicate 11% of abdominal wall closures, resulting in 200,000 incisional hernia repairs in the United States each year. Mechanical improvements alone in mesh, suture material, and surgical technique have failed to reduce the high rate of fascial wound failure. Sprague-Dawley rats underwent midline celiotomies that were closed with fast-absorbing suture to induce early biomechanical wound failure and incisional hernia formation. In primary wounds, fascial incisions were closed adjacent to a continuous release polygalactone polymer rod containing basic fibroblast growth factor (bFGF), no growth factor (control-rod), or without rods. In a second group, incisional hernias were repaired with either bFGF or control-rod therapy. Breaking strength was measured on postoperative day (POD) 7, and the incidence of incisional hernia formation was determined on POD 28. Treatment with bFGF rods significantly increased fascial wound breaking strength. In the "hernia-prevention" experiments, incisional hernias developed in 90% of untreated incisions, 60% of control-rod incisions, and only 30% of bFGF-rod incisions (P < 0.05). In the "hernia-treatment" experiments, recurrent incisional hernias developed in 86% of control-rod incisions compared with only 23% of bFGF-rod treated incisions (P < 0.05). Immunohistochemistry demonstrated increased angiogenesis and collagen protein production in bFGF treated incisions. The treatment of abdominal fascial incisions with a sustained-release bFGF polymer significantly lowered the incidence of incisional hernias and the recurrence rate after repair.

Repair of paracolostomy hernias with a prosthetic mesh in the intraperitoneal onlay position: modified Sugarbaker technique.

The disappointing outcome of local fascial repair and stoma relocation in parastomal hernias has stimulated a variety of new techniques that use a prosthetic mesh for herniorrhaphy. Many of these procedures either carry the risk of mesh contamination or allow only a local repair. We established a method that allows both an aseptic operation and the management of concurrent incisional hernias. In a retrospective study we evaluated all patients who had undergone operation for a paracolostomy hernia with an expanded polytetrafluoroethylene (PTFE) mesh in the intraperitoneal onlay position in our Department of General Surgery from 1994 until 2002. Twenty patients with large paracolostomy hernias and 10 additional ventral hernias, mostly large incisional or recurrent incisional hernias, were identified. We combined the Sugarbaker and the Rives-Stoppa techniques by covering the defects with an ePTFE mesh after laparotomy and fixing the mesh with traction sutures. Postoperatively, there was no incidence of mesh infection. After a mean follow-up of 3 1/2 years we found three recurrences of paracolostomy hernias and two recurrences of incisional hernias. Another two hernias emerged in the previously intact midline. All these hernias were small, without tendency to enlargement, and did not warrant reoperation. Patients with symptomatic paracolostomy hernias or a combination of abdominal wall defects should properly be managed surgically with an intraperitoneally placed mesh that covers all hernias. Our results, with a recurrence rate of only 15 percent for the parastomal site and 20 percent for combined defects, support this approach.

Abdominal ventral incisional herniorrhaphy: a brief review

Despite ongoing research in wound healing and adoption of innovative closure and reparative techniques, abdominal incisional hernia remains a persistent problem. There have been few operative challenges more vexing in the history of surgery than the incisional hernia. It is a common long-term complication of laparotomy, occurring in 2% to 11% of patients after an abdominal operation. Until very recently, innovations in reparative techniques over the last century have shown relatively little improvement in outcome and recurrence rates, which have approached 50% after multiple corrective attempts. In addition, controversy surrounds those factors postulated to predispose patients to this surgical outcome. Some recently developed technical options, both open and laparoscopic, reportedly decrease the rate of incisional hernia recurrence. This review will discuss predisposing factors, diagnosis, and surgical options in the repair of abdominal incisional hernias.

Hernia - A Collagen Disease?

Background: The reparation of abdominal wall hernias is one of the most frequently performed operations in surgery worldwide. Besides primary hernias, recurrent and incisional hernias are of particular interest in abdominal surgery. Knowledge about the pathogenesis and successful treatment of abdominal wall hernias are of major socioeconomic importance. Various risk factors for hernia formation have been proposed in the past. In recent years, turnover of connective tissue, particularly collagen, in hernia patients has been the focus of research. Methods: This article reviews the findings concerning collagen metabolism and expression in patients with (recurrent) inguinal and incisional hernia. Results: A disorder of the collagen metabolism is supposed to play a pivotal role in the pathogenesis of primary or recurrent inguinal and incisional hernias. Conclusions: Further research on collagen metabolism in these patients should be transposed into optimized surgical repair procedures.

Analysis of collagen-interacting proteins in patients with incisional hernias.

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. 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. 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. 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.