The biology of hernias and the abdominal wall

A novel electrospun polylactic acid silkworm fibroin mesh for abdominal wall hernia repair

Objective

Abdominal wall hernias are common abdominal diseases, and effective hernia repair is challenging. In clinical practice, synthetic meshes are widely applied for repairing abdominal wall hernias. However, postoperative complications, such as inflammation and adhesion, are prevalent. Although biological meshes can solve this problem to a certain extent, they face the problems of heterogeneity, rapid degradation rate, ordinary mechanical properties, and high-cost. Here, a novel electrospinning mesh composed of polylactic acid and silk fibroin (PLA-SF) for repairing abdominal wall hernias was manufactured with good physical properties, biocompatibility and low production cost.

Materials and methods

FTIR and EDS were used to demonstrate that the PLA-SF mesh was successfully synthesized. The physicochemical properties of PLA-SF were detected by swelling experiments and in vitro degradation experiments. The water contact angle reflected the hydrophilicity, and the stress‒strain curve reflected the mechanical properties. A rat abdominal wall hernia model was established to observe degradation, adhesion, and inflammation in vivo. In vitro cell mesh culture experiments were used to detect cytocompatibility and search for affected biochemical pathways.

Results

The PLA-SF mesh was successfully synthesized and did not swell or degrade over time in vitro. It had a high hydrophilicity and strength. The PLA-SF mesh significantly reduced abdominal inflammation and inhibited adhesion formation in rat models. The in vitro degradation rate of the PLA-SF mesh was slower than that of tissue remodeling. Coculture experiments suggested that the PLA-SF mesh reduced the expression of inflammatory factors secreted by fibroblasts and promoted fibroblast proliferation through the TGF-β1/Smad pathway.

Conclusion

The PLA-SF mesh had excellent physicochemical properties and biocompatibility, promoted hernia repair of the rat abdominal wall, and reduced postoperative inflammation and adhesion. It is a promising mesh and has potential for clinical application.

Awareness of Hernias and Their Risk Factors Among Adults in the Western Region of Saudi Arabia

Objective To assess the awareness of hernia and its risk factors among adults in the western region of Saudi Arabia. Our hypothesis was that the studied population was in need of education regarding this matter.  Methods This cross-sectional study was conducted in the western region of Saudi Arabia from November to December 2022, using a Google form. The generated questionnaire consisting of two parts was distributed electronically through social media platforms. The targeted population included adults from the western region of Saudi Arabia. The data were obtained using Microsoft Excel and analyzed using Statistical Package for Social Sciences (SPSS) v. 26 software (IBM Corp., Armonk, NY). Results A total of 1570 adults from the western region of Saudi Arabia were included in our study. We found that 13% of the participants had good overall knowledge about hernia, 31% had poor knowledge, and 56% had moderate knowledge. Alarmingly, 55% of the participants had a poor attitude, and 27% were evaluated as having poor practice. In addition, we found a significant association between people's level of knowledge and multiple factors, including age (p-value < 0.001), marital status (p-value< 0.001), and occupation (p-value< 0.001).  Conclusion Based on our research, more than half of our population had a moderate level of knowledge regarding hernias including their risk factors and complications, with alarming levels of poor attitudes toward the disease. Healthcare workers were our participants' leading source of medical information, which directs us towards fully equipping them with the knowledge to educate the public effectively.

Standardized suturing can prevent slackening or bursting suture lines in midline abdominal incisions and defects

Purpose

Incisional hernias often follow open abdominal surgery. A small-stitch–small-bite suture might close the incision durably. We analyzed specific details of this closure technique and assessed their influence on the closure stability.

Methods

The effects of cyclic loads, simulating coughs were investigated on a bench test. We prepared porcine bellies in the median line and bovine flanks parallel to the muscle fibers with 15 cm long incisions. Then we punched round or rhomboid defects with a diameter of 5–10 cm into the center of the incision. Monomax® 2–0 and Maxon® 1 and 2–0 were used as suture materials. We tested the durability of the closure with pressure impacts of 210 mmHg repeated 425 times. Throughout the experiments, we modified the suturing technique, the surgeon, the tissue tension, the defect size and shape and the suture diameter.

Results

Standardizing the suture technique improved the durability of the closure significantly. Any other variations showed minor influences after standardization. All incisions with round defects up to 7.5 cm width withstood 425 impacts using standardized suturing. Unstandardized sutures failed in all cases. When closing an incision with a 10 cm wide defect, the tissues ruptured frequently next to the suture line. We defined criteria to standardize this suturing technique. For the first time, we developed a suture factor related to the durability of a sutured tissue closure. We integrated the suture factor into the concept of biomechanically durable repairs.

Conclusions

Suturing the abdominal wall with a standardized suturing technique improves its durability significantly.

Primary and Recurrent Repair of Incisional Hernia Based on Biomechanical Considerations to Avoid Mesh-Related Complications

Aim: Mechanical principles successfully guide the construction of polymer material composites in engineering. Since the abdominal wall is a polymer composite augmented with a textile during incisional hernia repair we ask: can incisional hernia be repaired safely and durably based on biomechanical principles?

Material and Methods: Repair materials were assessed on a self-built bench test using pulse loads to elude influences on the reconstruction of the abdominal wall. Tissue elasticity was analyzed preoperatively as needed with computed tomography at rest and during Valsalva's maneuver. Preoperatively, the critical retention force of the reconstruction to pulse loads was calculated and a biomechanically durable repair was designed based on the needs of the individual patient. Intraoperatively, the design was adjusted as needed. Hernia meshes with high grip factors (Progrip^®, Dahlhausen^® Cicat) were used for the repairs. Mesh sizes, fixation elements and reconstructive details were oriented on the biomechanical design. All patients recieved single-shot antibiosis. Patients were discharged after full ambulation was achieved.

Results: A total of 163 patients (82 males and 81 females) were treated for incisional hernia in four hospitals by ten surgeons. Primary hernia was repaired in 119 patients. Recurrent hernia was operated on in 44 cases. Recurrent hernia was significantly larger (median 161 cm² vs. 78 cm²; u-test: p = 0.00714). Re-do surgery took significantly longer (median 229 min vs. 150 min; p < 0.00001) since recurrent disease required more often transversus abdominis release (70% vs. 47%). GRIP tended to be higher in recurrent repair (p = 0.01828). Complication rates (15%) and hospital stay were the same (6 vs. 6 days; p = 0.28462). After 1 year, no recurrence was detected in either group. Pain levels were equally low in both primary and recurrent hernia repairs (median NAS = 0 in both groups at rest and under load, p = 0.88866).

Conclusion: Incisional hernia can safely and durably be repaired based on biomechanical principles both in primary and recurrent disease. The GRIP concept provides a base for the application of biomechanical principles in incisional hernia repair.

New Insights into the Application of 3D-Printing Technology in Hernia Repair

Abdominal hernia repair using prosthetic materials is among the surgical interventions most widely performed worldwide. These materials, or meshes, are implanted to close the hernial defect, reinforcing the abdominal muscles and reestablishing mechanical functionality of the wall. Meshes for hernia repair are made of synthetic or biological materials exhibiting multiple shapes and configurations. Despite the myriad of devices currently marketed, the search for the ideal mesh continues as, thus far, no device offers optimal tissue repair and restored mechanical performance while minimizing postoperative complications. Additive manufacturing, or 3D-printing, has great potential for biomedical applications. Over the years, different biomaterials with advanced features have been successfully manufactured via 3D-printing for the repair of hard and soft tissues. This technological improvement is of high clinical relevance and paves the way to produce next-generation devices tailored to suit each individual patient. This review focuses on the state of the art and applications of 3D-printing technology for the manufacture of synthetic meshes. We highlight the latest approaches aimed at developing improved bioactive materials (e.g., optimizing antibacterial performance, drug release, or device opacity for contrast imaging). Challenges, limitations, and future perspectives are discussed, offering a comprehensive scenario for the applicability of 3D-printing in hernia repair.

Biomechanical Influences on Mesh-Related Complications in Incisional Hernia Repair

Aim: Hernia repair strengthens the abdominal wall with a textile mesh. Recurrence and pain indicate weak bonds between mesh and tissue. It remains a question which biomechanical factors strengthen the mesh-tissue interface, and whether surgeons can enhance the bond between mesh and tissue. Material and Methods: This study assessed the strength of the mesh-tissue interface by dynamic loads. A self-built bench test delivered dynamic impacts. The test simulated coughing. Porcine and bovine tissue were used for the bench test. Tissue quality, mesh adhesiveness, and fixation intensity influenced the retention power. The influences were condensed in a formula to assess the durability of the repair. The formula was applied to clinical work. The relative strength of reconstruction was related to the individual human abdominal wall. From computerized tomography at rest and during Valsalva's Maneuver, the tissue quality of the individual patient was determined before surgery. Results: The results showed that biomechanical parameters observed in porcine, bovine, and human tissue were in the same range. Tissues failed in distinct patterns. Sutures slackened or burst at vulnerable points. Both the load duration and the peak load increased destruction. Stress concentrations elevated failure rates. Regional areas of force contortions increased stress concentrations. Hernia repair improved strain levels. Measures for improvement included the closure of the defect, use of higher dynamic intermittent strain (DIS) class meshes, increased mesh overlap, and additional fixation. Surgeons chose the safety margin of the reconstruction as desired. Conclusion: The tissue quality has now been introduced into the concept of a critical and a gained resistance toward pressure-related impacts. A durable hernia repair could be designed from available coefficients. Using biomechanical principles, surgeons could minimize pain levels. Mesh-related complications such as hernia recurrence can potentially be avoided in incisional hernia repair.

Recommendations on Postoperative Activities After Abdominal Operations and Incisional Hernia Repair-A National and International Survey

Background: There is no conclusive data on postoperative recommendations after abdominal and hernia surgery, and there is significant variation in the literature on that question. Thus, this study evaluates the status quo of recommendations of postoperative activity restriction after abdominal surgery. Materials and Methods: A national (German) and international survey of general surgeons on postoperative recommendations after abdominal and hernia surgery was pooled and analyzed. Results: A total of 74.6% recommended postoperative reduced activity for 2 weeks or less after laparoscopy. For midline laparotomy, 48.8% considered a reduced activity of 4 weeks or less to be sufficient. A majority from the national survey recommended more than 4 weeks instead (60.2%), whereas only 31.5% from the international survey did so (p = 0.000). In the pooled analysis, 258 of 450 (57.3%) rated 4 weeks or less suitable. However, the recommendations differed significantly between the surveys (4 weeks or less: a national survey, 47.1% vs. international survey, 64.6%; p = 0.000). Conclusion: There was substantial variation in the given recommendations. However, we found no evidence against immediate mobilization, reduced physical activity, and lifting for up to 2 weeks after laparoscopic surgery and for up to 4 weeks after open abdominal surgery and open incisional/ventral hernia repair in uncomplicated and standard cases. There might be individual and socioeconomic benefits to allow patients to return to their whole personal level of activity and work without putting them at risk of complications. Due to lack of evidence, both retrospective and prospective, controlled studies are in need to develop reliable recommendations.

Large Bowel Obstruction

Nearly one-quarter of bowel obstructions occur in the large bowel. As with all bowel obstructions, large bowel obstructions have three defining characteristics: partial or complete, intrinsic or extrinsic, benign or malignant. The work-up for a large bowel obstruction should focus on the etiology of the obstruction as well as severity. Management strategy is contingent on the previous characteristics and can include endoscopy, diversion, or resection. This chapter will discuss common and rare etiologies of large bowel obstructions as well as management strategies for clinical guidance.

Experimental Study Comparing Structural Changes Induced by Biologic Versus Synthetic Mesh Implants in Nephropexy

Background: The study suggests that the use of the extracellular bovine-derived peritoneum matrix as a new biological implant opens up new prospects for nephropexy. Materials and Methods: Experimental nephropexy was performed in 64 white shorthaired adult rats, divided for 2 groups: extracellular bovine-derived peritoneum matrix, UltraPro mesh. Implants were 1,5*1,5cm per one animal. Observation periods were 7, 21, 30 and 180 days. The tissue was stain with H&E, Van Gieson’s with pikro-fuchin. Cellular infiltrate was evaluated by counting granulocytes, mononuclear cells, and foreign-body giant cells on five high-magnification images for each stained section (×400). Results: The use of the extracellular bovine-derived peritoneum matrix induced less intense and less prolonged chronic inflammatory response, as well as intense production of new collagen fibers more similar to the native connective tissue in terms of their histologic structure. The UltraPro mesh induced moderately persistent chronic inflammatory response throughout the 6- month study period. Conclusion: Histologic evaluation demonstrates high biocompatibility of both the extracellular bovine-derived peritoneum matrix, and the UltraPro mesh implants.The results of using  new biological material are not worse than synthetic mesh. The data obtained justify further research of the extracellular bovine-derived peritoneum matrix as a plastic material for nephropexy.

Recurrent incisional hernia repairs at a tertiary hernia center: Are outcomes really inferior to initial repairs?

BACKGROUND

Recurrent ventral hernia repairs are reported to have higher recurrence and complication rates than initial ventral hernia repairs. This is the largest analysis of outcomes for initial versus recurrent open ventral hernia repairs reported in the literature.

METHODS

A prospective, institutional database at a tertiary hernia center was queried for patients undergoing open ventral hernia repairs with complete fascial closure and synthetic mesh placement.

RESULTS

A total of 1,694 open ventral hernia repairs patients were identified, including 896 (52.9%) initial ventral hernia repairs and 798 (47.1%)recurrent ventral hernia repairs. Recurrent ventral hernia repair patients were more complex: older (P = .003), higher body mass index (P < .001), higher American Society of Anesthesiologists class (P < .001), incidence of diabetics (P = .003), comorbidities (P < .001), and larger hernia defects (133.3 ± 171.9 vs 220.2 ± 210.0; P < .001). Recurrent ventral hernia repairs also had longer operative times (161.6 ± 82.4 vs 188.2 ± 68.9 minutes; P < .001), increased use of preoperative botulinum toxin A injection (4.3% vs 10.1%; P = .01), components separation (19.2% vs 39.5%; P < .001), and panniculectomy (20.3% vs 35.8%; P < .001). The overall hernia recurrence rate was 4.4% at a mean follow-up of 36.6 ± 45.5 months. Between the initial ventral hernia repairs and recurrent ventral hernia repairs, the hernia recurrence rates were equivalent (4.2% vs 4.7%, P = .63). Rates of wound infection, seromas, hematomas, mesh infections, and wound related reoperations (P > .05) were nonsignificant.

CONCLUSION

At a tertiary hernia center, despite higher-risk patients, larger hernia defects, and increased components separation in recurrent ventral hernia repairs, early recurrence rates, wound complications, and reoperations are similar to initial ventral hernia repairs.

Postoperative ileus after laparoscopic primary and incisional abdominal hernia repair with intraperitoneal mesh (DynaMesh®-IPOM versus Parietex™ Composite): a single institution experience

PURPOSE

Laparoscopic primary or incisional abdominal hernia repair with intraperitoneal mesh placement is a well-accepted and safe technique. Evidence for complications however remains inconclusive, and little is known about the occurrence of postoperative ileus secondary to postoperative intra-abdominal adhesions with different types of IPOM meshes used. Therefore, we retrospectively compared the occurrence of postoperative ileus between two of the different meshes used in our center.

METHODS

Three hundred seventy-five patients who underwent ventral hernia repair with intraperitoneal mesh placement, either with a DynaMesh®-IPOM (FEG Textiltechnik mbH, Aachen, Nordrhein-Westfalen, Germany) or a Parietex™ Composite mesh (Medtronic, Minneapolis, MN, USA), at the Heilig-Hart Hospital in Lier (Antwerp, Belgium) between 2012 and 2017 were retrospectively compared with regard to the occurrence of postoperative ileus until 6 weeks postoperatively. Baseline demographics and clinical data up to 6 weeks postoperatively of the patients in the two mesh groups are provided.

RESULTS

The DynaMesh®-IPOM mesh group was associated with a significantly higher incidence of postoperative ileus compared with the Parietex™ Composite mesh group with a cutoff limit at postoperative day 1 (n = 17, 6.8% vs. n = 0, 0.0%; P = 0.003) and postoperative day 4 (n = 13, 5.2% vs. n = 0, 0.0%, P = 0.006), even with a mesh surface area of ≤ 300 cm² and when both meshes were fixated with the same method of fixation (Securestrap™) with a cutoff limit for postoperative ileus at postoperative day 1 (n = 4, 7.7% vs. n = 0, 0.0%; P = 0.013) and postoperative day 4 (n = 3, 5.8% vs. n = 0, 0.0%, P = 0.040). Of the 17 patients with a postoperative ileus, 9 (52.9%) had a suspicion of adhesive small bowel obstruction on CT scan (P = 0.033) with definitive confirmation of small bowel adhesions with the DynaMesh®-IPOM mesh at laparoscopy in 2 patients.

CONCLUSION

Our results confirm current literature available regarding postoperative ileus secondary to postoperative intra-abdominal adhesions with the DynaMesh®-IPOM mesh. However, further research with well-designed, multicenter randomized controlled studies to evaluate the use and related complications of these meshes is needed.

[Ventral hernias and extracellular matrix of connective tissue]

Ventral hernia is still one of the most common reason for scheduled and emergency surgery. The review is designed to reveal relationships between metabolism in extracellular matrix of connective tissue and pathogenesis of ventral hernias. These data will be valuable to develop a personalized approach to the treatment of these patients.

Results at 3-year follow-up of totally extraperitoneal (TEP) hernia surgery with long-term resorbable mesh

INTRODUCTION

Synthetic non-resorbable mesh is almost standard in hernia surgery. However, several studies have showed negative effects of permanent implants such as chronic inflammation and complications involving different organs bordering the mesh. Such complications can raise the risk of chronic post-operative pain (CPP). Recently promising results regarding CPP have been published in patients with Lateral Inguinal Hernia (LIH) using a slowly resorbable mesh in Lichtenstein technique. For this reason the aim of the present study was to find the effect of a slowly resorbable implant on the long-term rate of hernia recurrence and chronic post-operative pain in patients with LIH repaired with TEP procedure.

METHODS

Prospective pilot study of TEP repair using TIGR^® Matrix Surgical Mesh in 35 primary LIH. At 3-year follow-up the Visual Analogue Scale (VAS) and the Inguinal Pain Questionnaire were employed to assess pain. Recurrence was determined by ultrasound and clinical examination.

RESULTS

All patients completed the pain questionnaires but one patient did not attend the planned clinical examination for the 3-year follow-up. No patients had CPP, as defined in the World Guidelines for Groin Hernia Management. Almost all patients had lower VAS score in any activity 3 years following surgery in comparison to the preoperative period. Three patients (8.8%) suffered symptomatic recurrence during the 3-year follow-up.

CONCLUSION

TEP repair in patients with LIH using a synthetic long-term resorbable mesh was found to be encouraging respecting chronic post-operative pain at 3-year follow-up but at the cost of an increased risk of recurrence.

Optimal Suture Bite Size for Closure of Feline Linea Alba-A Cadaveric Study

Objective: This study aimed to determine the most appropriate suture bite and stitch interval (SBSI) size for closing feline linea alba.

Study design: Randomized ex vivo mechanical testing.

Sample population: Ventral abdominal walls from 35 male feline cadavers were harvested and separated into 125 segments.

Methods: Segments were incised along midline then sutured back together using 3-0 polydioxanone using one of the following SBSI: 3, 5, 7.5, or 10 mm whereby the distance represents the distance both between the suture bites, and from the bite to incision line. The location of segments as well as the weight of the cadaver were recorded. A single linear distraction mechanical breaking test was performed. Statistical analyses (logistic and linear regression) were performed to determine which factors were associated with visual and mechanical failure, as well as load at failure or maximum displacement.

Results: SBSI was significantly associated with load at failure or maximum displacement (p < 0.001). In particular, 5 mm SBSI had the highest load at failure amongst all the bite sizes (LSmeans = 27.55N, 95% Confidence Interval (CI): 23.65–31.44); this was significantly higher than 7.5 mm (LSmeans = 19.15N, 95% CI: 15.26–23.05, p = 0.016) and 10 mm (LSmeans = 16.55N, 95%CI:12.39–20.70, p = 0.0012) but not significantly higher than 3 mm (LSmeans = 23.78N, 95% CI: 19.69–27.86, p = 0.2). Increased SBSI increased the odds of visual failure (p < 0.001) whereas increased weight of the cadaver reduced the odds of visual failure (OR = 0.52, 95%CI: 0.30–0.88, p = 0.016).

Conclusion: The 5 mm SBSI had the highest load at failure and was not significantly different from the 3 mm SBSI when apposing feline linea alba using 3-0 polydioxanone.

Clinical significance: Using 5 mm SBSI is the preferred bite size compared to 7.5 or 10 mm SBSI when apposing feline linea alba with 3-0 polydioxanone.

Erratum: Addendum: Abdominal Wall Reconstruction: An Integrated Approach

[This corrects the article DOI: 10.1055/s-0038-1667062.].

Epigenetics-Shedding Light on the Path Ahead for Material Sciences

The harmonious regulation of bodily function is a necessity for healthy individuals. Looking from the viewpoint of material sciences, one can only marvel at the cellular factories, their renewal, and the overall control of messaging and control of responses. As aging progresses and/or pathologies arise, clinicians may be forced to look for replacement of organs/tissues with medical devices. Since all devices are tailored, a detailed understanding of developmental processes, including aberrant processes leading to pathologies, is crucial to provide clinicians with a suitable device. Although research in the field of epigenetics has produced effective therapeutics and diagnostic markers, our currently fragmented understanding of epigenetic processes as they relate to material development is inherently limited, with logical implications for the success of medical procedures. Here, we illustrate how material sciences for clinical applications, critically depend on all aspects of biomedical sciences, including the field of epigenetics.

Mesh materials and hernia repair

Hernia incidence has been observed since ancient time. Advancement in the medical textile industry came up with the variety of mesh materials to repair hernia, but none of them are without complications including recurrence of hernia. Therefore individuals once developed with the hernia could not lead a healthy and comfortable life. This drawn attention of surgeons, patients, researchers and industry to know the exact mechanism behind its development, complications and recurrence. Recent investigations highlighted the role of genetic factors and connective tissue disorders being the reason for the development of hernia apart from the abnormal pressure that is known to develop during other disease conditions. This review discusses different mesh materials, their advantages and disadvantages and their biological response after its implantation.

Biomimetic collagen/elastin meshes for ventral hernia repair in a rat model

Ventral hernia repair remains a major clinical need. Herein, we formulated a type I collagen/elastin crosslinked blend (CollE) for the fabrication of biomimetic meshes for ventral hernia repair. To evaluate the effect of architecture on the performance of the implants, CollE was formulated both as flat sheets (CollE Sheets) and porous scaffolds (CollE Scaffolds). The morphology, hydrophylicity and in vitro degradation were assessed by SEM, water contact angle and differential scanning calorimetry, respectively. The stiffness of the meshes was determined using a constant stretch rate uniaxial tensile test, and compared to that of native tissue. CollE Sheets and Scaffolds were tested in vitro with human bone marrow-derived mesenchymal stem cells (h-BM-MSC), and finally implanted in a rat ventral hernia model. Neovascularization and tissue regeneration within the implants was evaluated at 6weeks, by histology, immunofluorescence, and q-PCR. It was found that CollE Sheets and Scaffolds were not only biomechanically sturdy enough to provide immediate repair of the hernia defect, but also promoted tissue restoration in only 6weeks. In fact, the presence of elastin enhanced the neovascularization in both sheets and scaffolds. Overall, CollE Scaffolds displayed mechanical properties more closely resembling those of native tissue, and induced higher gene expression of the entire marker genes tested, associated with de novo matrix deposition, angiogenesis, adipogenesis and skeletal muscles, compared to CollE Sheets. Altogether, this data suggests that the improved mechanical properties and bioactivity of CollE Sheets and Scaffolds make them valuable candidates for applications of ventral hernia repair.

STATEMENT OF SIGNIFICANCE

Due to the elevated annual number of ventral hernia repair in the US, the lack of successful grafts, the design of innovative biomimetic meshes has become a prime focus in tissue engineering, to promote the repair of the abdominal wall, avoid recurrence. Our meshes (CollE Sheets and Scaffolds) not only showed promising mechanical performance, but also allowed for an efficient neovascularization, resulting in new adipose and muscle tissue formation within the implant, in only 6weeks. In addition, our meshes allowed for the use of the same surgical procedure utilized in clinical practice, with the commercially available grafts. This study represents a significant step in the design of bioactive acellular off-the-shelf biomimetic meshes for ventral hernia repair.

Laparoscopic ventral hernia repair: outcomes in primary versus incisional hernias: no effect of defect closure

PURPOSE

Supposing divergent aetiology, we found it interesting to investigate outcomes between primary (PH) versus incisional (IH) hernias. In addition, we wanted to analyse the effect of defect closure and mesh fixation techniques.

METHODS

37 patients with PH and 70 with IH were enrolled in a prospective cohort-study, treated with laparoscopic ventral hernia repair (LVHR) and randomised to ± transfascial sutures. In addition, we analysed results from a retrospective study with 36 PH and 51 IH patients. Mean follow-up time was 38 months in the prospective study and 27 months in the retrospective study.

RESULTS

35 % of PH's and 10 % of IH's were recurrences after previous suture repair. No late infections or mesh removals occurred. Recurrence rates in the prospective study were 0 vs. 4.3 % (p = 0.55) and the complication rates were 16 vs. 27 % (p = 0.24) in favour of the PH cohort. The IH group had a mesh protrusion rate of 13 vs. 5 % in the PH group (p = 0.32), and significantly (p < 0.01) larger hernias and adhesion score, longer operating time (100 vs. 79 min) and admission time (2.8 vs. 1.6 days). Closure of the hernia defect did not influence rate of seroma, pain at 2 months, protrusion or recurrence. An overall increased complication rate was seen after defect closure (OR 3.42; CI 1.25-9.33).

CONCLUSIONS

With PH, in comparison to IH treated with LVHR, no differences were observed regarding recurrence, protrusion or complication rates. Defect closure (raphe), when using absorbable suture, did not benefit long-term outcomes and caused a higher overall complication rate. (ClinicalTrials.gov number: NCT00455299).

Incidence of and risk factors for incisional hernia after abdominal surgery

BACKGROUND

Few larger studies have estimated the incidence of incisional hernia (IH) after abdominal surgery.

METHODS

Patients who had abdominal surgery between November 2009 and February 2011 were included in the study. The incidence rate and risk factors for IH were monitored for at least 180  days.

RESULTS

A total of 4305 consecutive patients were registered. Of these, 378 were excluded because of failure to complete follow-up and 3927 patients were analysed. IH was diagnosed in 318 patients. The estimated incidence rates for IH were 5·2 per cent at 12  months and 10·3 per cent at 24 months. In multivariable analysis, wound classification III and IV (hazard ratio (HR) 2·26, 95 per cent confidence interval 1·52 to 3·35), body mass index of 25 kg/m(2) or higher (HR 1·76, 1·35 to 2·30), midline incision (HR 1·74, 1·28 to 2·38), incisional surgical-site infection (I-SSI) (HR 1·68, 1·24 to 2·28), preoperative chemotherapy (HR 1·61, 1·08 to 2·37), blood transfusion (HR 1·46, 1·04 to 2·05), increasing age by 10-year interval (HR 1·30, 1·16 to 1·45), female sex (HR 1·26, 1·01 to 1·59) and thickness of subcutaneous tissue for every 1-cm increase (HR 1·18, 1·03 to 1·35) were identified as independent risk factors. Compared with superficial I-SSI, deep I-SSI was more strongly associated with the development of IH.

CONCLUSION

Although there are several risk factors for IH, reducing I-SSI is an important step in the prevention of IH.

REGISTRATION NUMBER

UMIN000004723 (University Hospital Medical Information Network, http://www.umin.ac.jp/ctr/index.htm).

Early outcome of incisional hernia repair using polypropylene mesh: A preliminary report

Background:

The use of prosthetics for open repair of incisional hernia is very recent in our practice. We highlight our experience repairing incisional hernias with polypropylene mesh.

Patients and Methods:

Patients presenting with incisional hernia >5 cm in length or width received open polypropylene mesh repair and were followed for two years. Data obtained included age, sex, primary surgery causing the hernia, the length of the fascial defect and previous attempts at repair. Post-operative wound complications were recorded. The integrity of the scar and patient satisfaction or concerns with the repair was assessed at each visit.

Results:

Nineteen females with a mean age of 35 years (range 30-54) underwent repair; most arising from obstetric or gynaecological procedures. Sixteen (82.2%) had midline, 2 (10.5) transverse and 1 (5.3) Pfannenstiel scars. One patient had no previous repair (R0), 7 had undergone one repair (R1), 9 had undergone two repairs (R2) and 1 had three previous repairs (R3). The length of fascial defects ranged from 8 to 18 cm and seroma collection and stitch sinus were the common problems encountered. Two (10.5%) recurrences were recorded in two years.

Conclusion:

Open mesh repair of incisional hernia carries a low risk of infection and recurrence in two years.

Abdominal closure reinforcement by using polypropylene mesh functionalized with poly-ε-caprolactone nanofibers and growth factors for prevention of incisional hernia formation

Incisional hernia affects up to 20% of patients after abdominal surgery. Unlike other types of hernia, its prognosis is poor, and patients suffer from recurrence within 10 years of the operation. Currently used hernia-repair meshes do not guarantee success, but only extend the recurrence-free period by about 5 years. Most of them are nonresorbable, and these implants can lead to many complications that are in some cases life-threatening. Electrospun nanofibers of various polymers have been used as tissue scaffolds and have been explored extensively in the last decade, due to their low cost and good biocompatibility. Their architecture mimics the natural extracellular matrix. We tested a biodegradable polyester poly-ε-caprolactone in the form of nanofibers as a scaffold for fascia healing in an abdominal closure-reinforcement model for prevention of incisional hernia formation. Both in vitro tests and an experiment on a rabbit model showed promising results.

Short- and long-term biomechanical and morphological study of new suture types in abdominal wall closure

To perform an abdominal-wall closure, a continuous suture is the preferred method. The suture materials that are most commonly employed in abdominal surgery are polypropylene and polydioxanone. However, in recent times, new products have been marketed, such as non-absorbable polyurethane with elastic properties (Assuplus(®), Assut Europe, Italy) and absorbable barbed polydioxanone (Filbloc(®), Assut Europe, Italy). The purpose of this study was to compare the ability of those against the standard polypropylene (Surgipro(TM), Covidien, USA) and polydioxanone (Assufil(®), Assut Europe, Italy) to mimic the biomechanical behavior of the abdominal wall closure. Comparison of the sutures was made first with the materials alone and later in a laparotomy closure of a rabbit abdomen, used as an animal model. The biomechanical analysis consisted of uniaxial tensile tests of threads and sutured samples of the animal abdomen. In the latter case, results were analyzed at short- (21days) and long- (180days) term intervals after the surgery. The morphology studies and collagen expression of the samples were also investigated. The results determined that polydioxanone and polypropylene sutures showed a linear elastic behavior, with barbed polydioxanone as the most compliant suture and polyurethane as the stiffest. The sutured samples showed a statistically significant loss of resistance, measured as the load needed to perform a certain stretch, when compared with the corresponding control tissue. Analysis of the stress-stretch curves showed that elastic polyurethane was the only suture able to reproduce the mechanical behavior of healthy tissue in the short term, while the rest of the sutures remained less stiff. This coincides with the expression of type I collagen observed in this group at this point in the study. In the long term, there was no difference among the sutures, and none was able to mimic control behavior.

Inguinal hernia repair using a synthetic long-term resorbable mesh: results from a 3-year prospective safety and performance study

PURPOSE

Conventional meshes for hernia repair and abdominal wall reinforcement are usually made from polypropylene, polyester or other synthetic plastic materials known to promote foreign body reactions and a state of chronic inflammation that may lead to long-term complications. A novel approach is to use long-term resorbable implants like TIGR(®) Matrix Surgical Mesh. Preclinical studies have shown that this mesh maintains mechanical integrity beyond the point in time where newly formed tissue is capable of carrying the abdominal loads.

METHODS

This was a first-in-man, prospective, pilot study performed during 2009, at two sites in Sweden. Forty patients with primary inguinal hernias were enrolled for Lichtenstein repair using TIGR(®) Matrix Surgical Mesh. The primary endpoint was safety as assessed by monitoring the incidence of adverse events and serious adverse events (SAEs) both related and unrelated to the mesh. The secondary endpoint was pain or discomfort. Visual Analogue Scale (VAS) 0-10 and Inguinal Pain Questionnaire were used for scoring pain and discomfort. Included patients have been followed for 36 months using ultrasound in combination with clinical examination.

RESULTS

All patients followed a normal early postoperative course. After 12 months no SAEs were reported. None of the patients with an isolated lateral inguinal hernia (LIH) had developed a recurrence but 4 (44 %) with medial and 4 (33 %) with combined hernias had recurred at 36-month follow-up. After 3-year follow-up none of the patients with LIH reported pain in the VAS-form and none of those patients could feel the sensation of a mesh in their groin. In the total study population 5 (16 %) patients experienced chronic pain in the form of mild sporadic pain and 3 (9.7 %) patients could feel the sensation of a mesh in their groin.

CONCLUSION

The use of a synthetic long-term resorbable mesh (TIGR(®) Matrix Surgical Mesh) in Lichtenstein repair was found to be safe, without recurrences, and promising regarding pain/discomfort at 3-year follow-up in patients with LIH. However, patients with medial and combined inguinal hernias had high recurrence rates.

Association of collagen type I alpha 1 gene polymorphism with inguinal hernia

PURPOSE

A positive family history is an important risk factor for inguinal hernia development, suggesting a genetic trait for hernia disease. However, gene mutations responsible for abdominal wall hernia formation in humans have not yet been studied. We aimed to evaluate whether the functional Sp1 binding site polymorphism within intron 1 of the collagen type I, alpha 1 (COL1A1) gene was associated specifically with inguinal hernia disease.

METHODS

85 participants with surgically diagnosed inguinal hernia disease, and 82 physically active controls without any history of connective tissue disease and hernia were recruited for this case-control genetic association study. Polymerase chain reaction and restriction fragment length polymorphism and agarose gel electrophoresis techniques were used to detect these polymorphisms.

RESULTS

Significantly, more patients gave a positive family history for an inguinal hernia compared to healthy controls (OR 3.646, 95 % CI 1.375-9.670, P = 0.006). COL1A1 Sp1 SNP (rs 1800012) was identified. Results demostrated statistically significant deviation from HWE for cases (P = 0.007), but not for the controls (P = 0.276). Our results revealed an increased frequency of COL1A1 Sp1 Ss genotype in inguinal hernia patients (OR 3.593, 95 % CI 1.867-6.915, P = 0.000).

CONCLUSIONS

This results suggest that polymorphism of the COL1A1 Sp1 binding site is associated with an increased risk for developing inguinal hernias. So, rs 1800012 locus is a potential candidate region for susceptibility in molecular mechanism of inguinal hernia pathophysiology.

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.

Reversibility of abdominal wall atrophy and fibrosis after primary or mesh herniorrhaphy

OBJECTIVE

To determine whether primary or mesh herniorrhaphy reverses abdominal wall atrophy and fibrosis associated with hernia formation.

BACKGROUND

We previously demonstrated that hernia formation is associated with abdominal wall atrophy and fibrosis after 5 weeks in an animal model.

METHODS

A rat model of chronic incisional hernia was used. Groups consisted of uninjured control (UC, n = 8), sham repair (SR, n = 8), unrepaired hernia (UR, n = 8), and 2 repair groups: primary repair (PR, n = 8) or tension-free polypropylene mesh repair (MR, n = 8) hernia repair on postoperative day (POD) 35. All rats were killed on POD 70. Intact abdominal wall strips were cut perpendicular to the wound for tensiometric analysis. Internal oblique muscles were harvested for fiber type and size determination.

RESULTS

No hernia recurrences occurred after PR or MR. Unrepaired abdominal walls significantly demonstrated greater stiffness, increased breaking and tensile strengths, yield load and yield energy, a shift to increased type IIa muscle fibers than SR (15.9% vs 9.13%; P < 0.001), and smaller fiber cross-sectional area (CSA, 1792 vs 2669 μm(2); P < 0.001). PR failed to reverse any mechanical changes but partially restored type IIa fiber (12.9% vs 9.13% SR; P < 0.001 vs 15.9% UR; P < 0.01) and CSA (2354 vs 2669 μm(2) SR; P < 0.001 vs 1792 μm(2) UR; P < 0.001). Mesh-repaired abdominal walls demonstrated a trend toward an intermediate mechanical phenotype but fully restored type IIa muscle fiber (9.19% vs 9.13% SR; P > 0.05 vs 15.9% UR; P < 0.001) and nearly restored CSA (2530 vs 2669 μm(2) SR; P < 0.05 vs 1792 μm(2) UR; P < 0.001).

CONCLUSIONS

Mesh herniorrhaphy more completely reverses atrophic abdominal wall changes than primary herniorrhaphy, despite failing to restore normal anatomic muscle position. Techniques for hernia repair and mesh design should take into account abdominal wall muscle length and tension relationships and total abdominal wall compliance.

Primary Closure of the Abdominal Wall After “Open Abdomen” Situation

“Open abdomen” is a strategy used to avoid or treat abdominal compartment syndrome. It has reduced mortality both in trauma and non-trauma abdominal catastrophes but also has created a challenging clinical problem. Traditionally, open abdomen is closed in two phases; primarily with a free skin graft and later with a flap reconstruction. A modern trend is to close the abdomen within the initial hospitalization. This requires multi-professional co-operation. Temporary abdominal closure methods, e.g. negative pressure wound therapy alone or combined with mesh-mediated traction, have been developed to facilitate direct fascial closure. Components separation technique, mesh reinforcement or bridging of the fascial defect with mesh and perforator saving skin undermining can be utilized in the final closure if needed. These techniques can be combined. Choice of the treatment depends on the condition of the patient and size of the fascia and skin defect, and the state of the abdominal contents.

In this paper we review the literature on the closure of an open abdomen and present the policy used in our institution in the open abdomen situations.

A prospective evaluation of the risk factors for development of wound dehiscence and incisional hernia

OBJECTIVE

Post-laparotomy wound dehiscence, evantration and evisceration are important complications leading to an increase in both morbidity and mortality. Incisional hernias are frequently observed following abdominal surgeries and their occurrence is related to various local and systemic factors. This study aims to analyze the factors affecting wound healing by investigating the parameters that may cause wound dehiscence, incisional hernia, sinus formation and chronic incisional pain.

MATERIAL AND METHODS

The records of 265 patients who underwent major abdominal surgery were analyzed. The data on patient characteristics, medication, surgical procedure type, type of suture and surgical instruments used and complications were recorded. The patients were followed up with respect to sinus formation, incisional hernia occurrence and presence of chronic incision pain. Statistical analysis was performed using SPSS 10.00 program. The groups were compared via chi-square tests. Significance was determined as p<0.05. Multi-variate analysis was done by forward logistic regression analysis.

RESULTS

115 (43.4%) patients were female and 150 (56.6%) were male. Ninety-four (35.5%) patients were under 50 years old and 171 (64.5%) were older than 50 years. The median follow-up period was 28 months (0-48). Factors affecting wound dehiscence were found to be; creation of an ostomy (p=0.002), postoperative pulmonary problems (p=0.001) and wound infection (p=0.001). Factors leading to incisional hernia were; incision type (p=0.002), formation of an ostomy (p=0.002), postoperative bowel obstruction (p=0.027), postoperative pulmonary problems (p=0.017) and wound infection (p=0.011).

CONCLUSION

Awareness of the factors causing wound dehiscence and incisional hernia in abdominal surgery, means of intervention to the risk factors and taking relevant measures may prevent complications. Surgical complications that occur in the postoperative period are especially related to wound healing problems.

Effects of prokinetic drugs on the abdominal wall wound healing of rats submitted to segmental colectomy and colonic anastomosis

PURPOSE

To assess the effect of prokinetic agents on abdominal wall wound healing in rats submitted to segmental colectomy and colonic anastomosis.

METHODS

Sixty rats were randomly allocated into three groups according to the agents they would receive in the postoperative period: M (metoclopramide); B (bromopride); and C (control, saline 0.9%). Surgical procedures were performed identically in all animals, and consisted of a midline laparotomy followed by resection of a 1-cm segment of large bowel with end-to-end anastomosis. The abdominal wall was closed in two layers with running stitches. Abdominal wall samples were collected on the 3rd or 7th postoperative day for measurement of breaking (tensile) strength and histopathological assessment.

RESULTS

There were no statistically significant differences in tensile strength of the abdominal wall scar between groups M, B, and C, nor between the three and seven days after surgery subgroups. On histopathological assessment, there were no statistically significant between-group differences in collagen deposition or number of fibroblasts at the wound site

CONCLUSION

Use of the prokinetic drugs metoclopramide or bromopride had no effect on abdominal wall healing in rats submitted to segmental colectomy and colonic anastomosis.

Incisional hernia recurrence through genomic profiling: a pilot study

PURPOSE

Although situational risk factors for incisional hernia formation are known, the methods used to determine who would be most susceptible to develop one are unreliable. We hypothesized that patients with recurrent incisional hernias may possess unique gene expression profiles.

METHODS

Skin and intact fascia were collected from 15 normal control (NC) patients with no hernia history and 18 patients presenting for recurrent incisional hernia (RH) repair. Microarray analysis was performed using whole genome microarray chips on NC (n = 8) and RH (n = 9). These samples were further investigated using a pathway-specific PCR array containing fibrosis-related genes.

RESULTS

Microarray data revealed distinct differences in the gene expression profiles between RH and NC patients. One hundred and sixty-seven genes in the skin and 7 genes in the fascia were differentially expressed, including 8 directly involved in collagen synthesis. In particular, GREMLIN1, or bone morphogenetic protein antagonist 1, was under expressed in skin (fold = 0.49, p < 10(-7), q = 0.0009) and fascia (fold = 0.23, p < 10(-4), q = 0.095) of RH patients compared with NC. The PCR array data supported previous reports of decreased collagen I/III ratios in skin of RH versus NC (mean = 1.51 ± 0.73 vs. mean = 2.26 ± 0.99; one-sided t test, p = 0.058).

CONCLUSION

To our knowledge, this is the first microarray-based analysis to show distinct gene expression profiles between the skin and fascia of RH and NC patients and the first report of an association between GREMLIN1 and incisional hernia formation. Our results suggest that gene expression profiles may act as surrogate markers that stratify patients into different groups at risk for hernia development prior to their initial surgery.

Altering surface characteristics of polypropylene mesh via sodium hydroxide treatment

Incisional hernias represent a serious and common complication following laparotomy. The use of synthetic (e.g. polypropylene) meshes to aid repair of these hernias has considerably reduced recurrence rates. While polypropylene is biocompatible and has a long successful clinical history in treating hernias and preventing reherniation, this material may suffer some limitations, particularly in challenging patients at risk of wound failure due to, for example, an exaggerated inflammation reaction, delayed wound healing, and infection. Surface modification of the polypropylene mesh without sacrificing its mechanical properties, critical for hernia repair, represents one way to begin to address these clinical complications. Our hypothesis is treatment of a proprietary polypropylene mesh with sodium hydroxide (NaOH) will increase in vitro NIH/3T3 cell attachment, predictive of earlier and improved cell colonization and tissue integration of polypropylene materials. Our goal is to achieve this altered surface functionality via enhanced removal of chemicals/oils used during material synthesis without compromising the mechanical properties of the mesh. We found that NaOH treatment does not appear to compromise the mechanical strength of the material, despite roughly a 10% decrease in fiber diameter. The treatment increases in vitro NIH/3T3 cell attachment within the first 72 h and this effect is sustained up to 7 days in vitro. This research demonstrates that sodium hydroxide treatment is an efficient way to modify the surface of polypropylene hernia meshes without losing the mechanical integrity of the material. This simple procedure could also allow the attachment of a variety of biomolecules to the polypropylene mesh that may aid in reducing the complications associated with polypropylene meshes today.

Loss of mechanical strain impairs abdominal wall fibroblast proliferation, orientation, and collagen contraction function

BACKGROUND

Laparotomy wound load forces are reduced when dehiscence and incisional hernia formation occur. The purpose of this study was to determine the effects of strain loss on abdominal fascial fibroblast proliferation, orientation, and collagen compaction function.

METHODS

Cultured rat linea alba fibroblasts were subjected to continuous cyclic strain (CS), CS interrupted at 24 or 48 hours followed by culture at rest (IS-24 and IS-48) or were cultured without mechanical strain (NS). Cell number was measured and images analyzed for cell orientation. Fibroblasts from these groups were seeded onto the surface of (FPCL-S) or mixed into (FPCL-M) a collagen gel matrix and gel area was measured over time.

RESULTS

Continuous strain stimulated proliferation when compared with the nonstrained cells. The loss of strain (IS) delayed proliferation compared with CS throughout (P < .05). CS fibroblasts aligned perpendicular to the direction of strain within 12 hours. Within 12 hours of strain loss, IS-48 fibroblasts became significantly less aligned (P < .0001), and seemed similar to the randomly organized NS fibroblasts 48 hours after strain removal. The CS and IS-24 groups demonstrated faster and greater overall FPCL-M compaction than both the IS-48 and NS groups (P < .0002). The CS group contracted the gel faster than the NS group in FPCL-S (P = .029).

CONCLUSION

Mechanical strain rapidly induces a proliferative, morphologic, and functional response in abdominal wall fibroblasts that is dependent on the continued presence of the strain signal and quickly lost when the load force is removed. The loss of wound edge tension that occurs during laparotomy wound separation and hernia formation may contribute to impaired wound healing through loss of a key stimulatory mechanical signal with important implications for abdominal wall reconstruction.

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.

Randomized clinical trial comparing polypropylene or polydioxanone for midline abdominal wall closure

BACKGROUND

Incisional hernia is a frequent complication of abdominal surgery, often requiring surgical intervention. This prospective randomized trial compared suture materials for closure of the fascia after abdominal surgery.

METHODS

In 456 patients the abdominal fascia was closed with either non-absorbable (polypropylene; Prolene(®)) or absorbable (polydioxanone; PDS(®)) suture material. Follow-up was by clinical examination and ultrasonography at 6-month intervals. Outcome measures were incisional hernia, surgical-site infection and suture sinus.

RESULTS

Some 223 patients were analysed after closure with Prolene(®) and 233 after PDS(®) . Median follow-up was 32 and 31 months respectively. There was no significant difference in the incidence of incisional hernia between the groups: 20·2 per cent (45 of 223) for Prolene(®) and 24·9 per cent (58 of 233) with PDS(®) (P = 0·229). Kaplan-Meier analysis showed a cumulative rate after 4 years of 23·7 and 30·2 per cent for Prolene(®) and PDS(®) respectively (P = 0·222). Secondary outcome measures showed no significant differences.

CONCLUSION

The incidence of incisional hernia in both groups was higher than expected from previous literature. There were no significant differences between the two suture methods.

REGISTRATION NUMBER

ISRCTN65599814 (http://www.clinical-trials.com).

Site-specific prolapse surgery. I. Reliability and durability of native tissue paravaginal repair

Introduction and hypothesis

This study aims to compare native tissue abdominal and vaginal paravaginal repair, and to investigate whether surgical outcome was independent of operative route.

Methods

Retrospective comparison of 111 displacement cysto-urethrocoeles, repaired between 1997 and 2007. Treatment was by surgeon assignment, 52 women having abdominal (APVR) and 59 vaginal paravaginal repairs. Main outcome measures were same-site prolapse recurrence, time to failure and surgical complications. Initial reliability was evaluated by chi-square test, 10-year durability by Kaplan–Meier survival analysis and Cox proportional hazards model.

Results

When examined in the Cox proportional hazards model, anatomic results of APVR were more durable than a mechanically analogous transvaginal operation done [95% CI = 1.029–2.708 (p value = 0.038)]. Kaplan–Meier curves plateaued within 38 months. Symptom resolution was broadly equivalent. Surgical complication rate was 3.6%.

Conclusions

Site-specific re-suture of torn native tissue has genuine curative potential. Most of the long-term success was attributable to site-specific repair, rather than non-specific scar formation.

Site-specific prolapse surgery. II. Vaginal paravaginal repair augmented with either synthetic mesh or remodelling xenograft

INTRODUCTION AND HYPOTHESIS

This study aims to answer the question, "Does tissue augmentation improve the mechanical repair of displacement cystourethrocoele?"

METHODS

A retrospective cohort study comparing 108 bridging graft vaginal paravaginal repairs (89 tissue-inductive xenografts and 19 polypropylene mesh) to 59 native tissue historical controls was conducted. Main outcome measures were same-site prolapse recurrence and time to failure. Initial reliability was evaluated by chi-squared test, 10-year durability by Kaplan-Meier survival analysis and risk factors by Cox regression.

RESULTS

Late recurrence was 17.7% lower with augmentation (logrank test χ (2) = 8.4, p value = 0.0038 < 0.05, adjusted regression analysis χ (2) = 2.94; p value = 0.0866 <0.10), implicating collagen degeneration in repair failure.

CONCLUSIONS

Rebuilding the pubocervical septum, from arcus to arcus and pubic ramus to pericervical ring, satisfies the mechanical but not the metabolic hernia principles. Bridging grafts simplify technical repair (reducing prolapse persistence from 10.2% to 4.6%), and also rejuvenate adjacent connective tissue (reducing late recurrence from 22.6% to 4.9%).