Evaluation of four mesh fixation methods in an experimental model of ventral hernia repair

Establishment and evaluation of rat models of parastomal hernia

PURPOSE

Parastomal hernia poses a challenging problem in the field of hernia surgery. The high incidence and recurrence rates of parastomal hernia necessitate surgeons to enhance surgical techniques and repair materials. This study aimed to develop a rat model of parastomal hernia by inducing various types of defects on the abdominal wall with colostomy. This established method has potential for future studies on parastomal hernia.

METHODS

In this study, 32 male rats were included and randomly divided into four groups: the oblique abdominis excision (OE), oblique abdominis dissection (OD), rectus abdominis excision (RE), and rectus abdominis dissection (RD) groups. In each group, colostomy was performed and an abdominal wall defect was induced. The rats were observed for 28 days following surgery. The survival rate, body weight, parastomal hernia model scores, abdominal wall adhesion and inflammation, and collagen level in the hernial sac were compared.

RESULTS

No significant differences in survival rate and weight were observed among the four groups. The parastomal hernia model scores in the RE and RD groups were significantly higher than those in the OE and OD groups. The ratio of collagen I/III in the RE and RD groups was significantly lower than that in the OE and OD groups. Adhesion and inflammation levels were lower in the RE group than in the RD group.

CONCLUSION

Based on a comprehensive comparison of the findings, RE with colostomy emerged as the optimal approach for establishing parastomal hernia models in rats.

Safety and tissue remodeling assay of small intestinal submucosa meshes using a modified porcine surgical hernia model

In studies to date, meshes based on extracellular matrix (ECM) have been extensively used in clinical applications. Unfortunately, little is known about the function of the immunogenic residual, absorbable profile during the tissue repair process. Moreover, there needs to be a recognized preclinical animal model to investigate the safety and efficacy of extracellular matrix meshes. Herein, we designed and fabricated a kind of SIS mesh followed by a scanned electron micrograph characterization and tested α-Gal antigen clearance rate and DNA residual. In order to prove the biocompatibility of the SIS mesh, cell viability, chemotaxis assay and local tissue reaction were assessed by MTT and RTCA cytotoxicity test in vitro as well as implantation and degradation experiments in vivo. Furthermore, we developed a stable preclinical animal model in the porcine ventral hernia repair investigation, which using laparoscopic plus open hybridization method to evaluate tissue adhesion, explant mechanical performance, and histologic analysis after mesh implantation. More importantly, we established a semi-quantitative scoring system to examine the ECM degradation, tissue remodeling and regeneration in the modified porcine surgical hernia model for the first time. Our results highlight the application prospect of the improved porcine ventral hernia model for the safety and efficacy investigation of hernia repair meshes.

Safety and efficacy of absorbable and non-absorbable fixation systems for intraperitoneal mesh fixation: an experimental study in swine

PURPOSE

Choice of the best possible fixation system in terms of safety and effectiveness for intraperitoneal mesh placement in hernia surgery remains controversial. The aim of the present study was to compare the performance of four fixation systems in a swine model of intraperitoneal mesh fixation.

METHODS

Fourteen Landrace swine were utilized in the study. The experiment included two stages. Initially, four pieces of mesh (Ventralight ™ ST) sizing 10 × 5 cm were placed and fixed intraperitoneally to reinforce 4 small full thickness abdominal wall defects created with diathermy. These defects were repaired primarily with absorbable suture before mesh implantation. Each mesh was anchored with a different tack device between Absorbatack™, Protack™, Capsure™, or Optifix™. The second stage took place after 60 days and included euthanasia, laparoscopy, and laparotomy via U-shaped incision to obtain the measurements for the outcome parameters. The primary endpoint of the study was to compare the peel strength of the compound tack/mesh from the abdominal wall. Secondary parameters were the extent and quality of visceral adhesions to the mesh, the degree of mesh shrinkage and the histological response around the tacks.

RESULTS

Thirteen out of 14 animals survived the experiment and 10 were included in the final analysis. Capsure™ tacks had higher peel strength when compared to Absorbatack™ (p = 0.028); Protack™ (p = 0.043); and Optifix™ (p = 0.009). No significant differences were noted regarding the extent of visceral adhesions (Friedman's test p value 0.854), the adhesion quality (Friedman's test p value 0.506), or the mesh shrinkage (Friedman's test p value = 0.827). Four out of the ten animals developed no adhesions at all 2 months after implantation.

CONCLUSION

Capsure™ fixation system provided higher peel strength that the other tested devices in our swine model of intraperitoneal mesh fixation. Our findings generate the hypothesis that this type of fixation may be superior in a clinical setting. Clinical trials with long-term follow-up are required to assess the safety and efficacy of mesh fixation systems in hernia surgery.

Strategies for Mesh Fixation in Abdominal Wall Reconstruction: Concepts and Techniques

SUMMARY

Ventral hernias have numerous causes, ranging from sequelae of surgical procedures to congenital deformities. Patients suffering from these hernias experience a reduced quality of life through pain, associated complications, and physical disfigurement. Therefore, it is important to provide these patients with a steadfast repair that restores functionality and native anatomy. To do this, techniques and materials for abdominal wall reconstruction have advanced throughout the decades, leading to durable surgical repairs. At the cornerstone of this lies the use of mesh. When providing abdominal wall reconstruction, a surgeon must make many decisions with regard to mesh use. Along with the type of mesh and plane of placement of mesh, a surgeon must decide on the method of mesh fixation. Fixation of mesh provides an equal distribution of tension and a more robust tissue-mesh interface, which promotes integration. There exist numerous modalities for mesh fixation, each with its own benefits and drawbacks. This Special Topic article aims to compare and contrast methods of mesh fixation in terms of strength of fixation, clinical outcomes, and cost-effectiveness. Methods included in this review are suture, tack, fibrin glue, mesh strip, and self-adhering modes of fixation.

Dual Tack Mesh Fixation System on a Cadaveric Porcine Model-Creation of a Mesh Fixation System for Hernia Treatment and Prevention

BACKGROUND

Onlay mesh repair (OMR) has proven to be a widely used, simple, and effective technique for treatment and prevention of hernia occurrence. Despite established benefits, there is still a lack of widespread adoption. In this study, we present the Dual Tacker Device (DTD), an enabling technology that directly addresses the limitations to the adoption of OMR, saving surgical time and effort and making OMR more reproducible across a wide range of patients.

METHODS

The DTD mesh fixation system is a semiautomated, hand-held, disposable, multipoint onlay mechanical mesh fixation system that is able to rapidly and uniformly tension and fixate mesh for both hernia treatment and prevention. A cadaveric porcine model was used as a pilot test conducted during a 2 day session to assess the usability of the device and to show that the DTD provided equivalent or superior biomechanical support compared with the standard of care (hand-sewn, OptiFix).

RESULTS

Our study included 37 cadaveric porcine incisional closure abdominal wall models. These were divided into four groups: DTD-mediated OMR (n = 14), hand-sewn OMR (n = 7), OptiFix OMR (n = 9), and suture-only repair (no mesh) (n = 7). Eight surgical residents performed device-mediated and hand-sewn OMR. Average time to completion was fastest in the DTD cohort (45.6s) with a statistically significant difference compared with the hand-sewn cohort (343.1s, P < 0.01). No difference in tensile strength was noted between DTD (195.32N), hand-sewn (200.48N), and OptiFix (163.23N). Discreet hand movements were smallest in the DTD (29N) and significant (P < 0.01) when compared with hand-sewn (202N) and OptiFix (35N).

CONCLUSIONS

The use of the DTD is not only feasible, but demonstrated improvement in time to completion and economy of movement over current standard of care. While more testing is needed and planned, compared with conventional approaches, the DTD represents a robust proof of principle with promising implications for clinical feasibility and adoptability.

[Application of adhesive compositions in surgery (in Russian only)]

New adhesive compositions will almost completely prevent leakage of surgical sutures and undue tissue damage, improve healing and postoperative rehabilitation. At present time there is no universal type of bioadhesives that is suitable for all tissues and types of sutures because of various surgeries and their specificity. The article describes the advantages and disadvantages of all common types of bioadhesives, as well as the ways to overcome their disadvantages.

Laparoscopic management of recurrent ventral hernia: an experience of 222 patients

BACKGROUND

To evaluate the predisposing factors and characteristics of recurrent ventral hernia (RVH) along with the feasibility and outcome of laparoscopy in managing RVH.

METHODS

This study is a retrospective analysis of all patients with reducible or irreducible, uncomplicated RVH who underwent surgical management from January 2012 to June 2018.

RESULTS

Out of 222 patients, 186 (83.8%) were female, and 36 (16.2%) were male. The mean age was 54.1 ± 10.1 years; an average body mass index was 31 kg/m² (19-47.9). The most common previous abdominal operations among female patients were cesarean sections (43.5%) and abdominal hysterectomy (36.6%). Most of the patients had a history of open mesh repair (43.7%) and open anatomical repair (36.9%). The median time of recurrence was 4 years (1-33 years). The median defect size was 10 cm² (range 2-150 cm²), and 73% defects were in the midline. Total 181 of 222 (81.6%) patients underwent laparoscopic intraperitoneal onlay mesh plus (L-IPOM+), 19 (8.5%) laparoscopic-assisted IPOM+, 17(7.7%) laparoscopic anatomical repair, while remaining 5 (2.3%) patients required open mesh reconstruction. The median size of the composite mesh used was 300 cm² (150-600 cm²). The mean operating time was 145 (30-330) min, and median blood loss was 15 (5-110) ml. The median hospital stay was 3 days, and median follow-up period was 37 months. The post-operative symptomatic seroma rate was 3.1%, and re-recurrence rate was 1.4%.

CONCLUSION

Obesity, old age, female sex, previous lower abdominal surgeries, and previous open repair of a hernia are factors associated with recurrence. Laparoscopic repair is feasible with excellent outcome in most of the patients.

Fibrin glue mesh fixation combined with mesenchymal stem cells or exosomes modulates the inflammatory reaction in a murine model of incisional hernia

Surgical meshes are effective and frequently used to reinforce soft tissues. Fibrin glue (FG) has been widely used for mesh fixation and is also considered an optimal vehicle for stem cell delivery. The aim of this preclinical study was to evaluate the therapeutic effect of MSCs and their exosomes combined with FG for the treatment of incisional hernia. A murine incisional hernia model was used to implant surgical meshes and different treatments with FG, MSCs and exo-MSCs were applied. The implanted meshes were evaluated at day 7 by anatomopathology, cellular analysis of infiltrating leukocytes and gene expression analysis of TH1/TH2 cytokines, MMPs, TIMPs and collagens. Our results demonstrated a significant increase of anti-inflammatory M2 macrophages and TH2 cytokines when MSCs or exo-MSCs were used. Moreover, the analysis of MMPs, TIMPs and collagen exerted significant differences in the extracellular matrix and in the remodeling process. Our in vivo study suggests that the fixation of surgical meshes with FG and MSCs or exo-MSCs will have a beneficial effect for the treatment of incisional hernia in terms of improved outcomes of damaged tissue, and especially, in the modulation of inflammatory responses towards a less aggressive and pro-regenerative profile.

STATEMENT OF SIGNIFICANCE

The implantation of surgical meshes is the standard procedure to reinforce tissue defects such as hernias. However, an exacerbated and persistent inflammatory response secondary to this implantation is frequently observed, leading to a strong discomfort and chronic pain in the patients. In many cases, an additional surgical intervention is needed to remove the mesh. This study shows that mesenchymal stem cells and their exosomes, combined with a fibrin sealant, can be used for the successful fixation of these meshes. This new therapeutic approach, assayed in a murine model of incisional hernia, favors the modulation of the inflammatory response towards a less aggressive and pro-regenerative profile.

Is there difference in chronic pain after Suture and Stapler fixation method of mesh in Ventral Hernia? Is stapler fixation method quicker? A randomized controlled trial

Background & Objective:

Chronic pain occurs in 20–30% of patients after hernia surgery. As a consequence of this chronic pain, almost one third of patients have limitations in daily activities. Frequency and severity of this pain varies with different techniques of hernia repair. The objective of this study was to compare polypropylene suture and skin staples for securing mesh in uncomplicated ventral hernioplasty in terms of acute and chronic postoperative pain and to compare the time taken for mesh fixation between polypropylene sutures and skin stapler in ventral hernioplasty.

Methods:

This study was conducted in Surgery Department of Dow University Hospital, Dow University of Health Sciences, Ojha Campus and included 53 patients from Jan 2015 to Dec 2016, after taking informed consent. All patients were operated under general anesthesia by the same surgical team. Patients were randomized into two groups; in one group mesh fixed with 2/0 polypropylene suture while in other group mesh stapler was used. Time taken to apply mesh was noted in minutes from laying the mesh over anterior rectus sheath to completion of fixation by either method. The severity of post-operative pain was measured with VAS (1-10) after one week, one month and after one year after surgery. Data was analysed using SPSS version 17.

Results:

Patient characteristics and operative outcome were similar in the two groups and statistically non-significant in both. Early postoperative pain was more after suture fixation but it was not statistically significant. Mean ± SD pain score was after one week 3.47±2.7 after sutures while 2.91±1.88 after stapler. After four weeks, 0.40±0.49 after suture while 0.35±0.48 after stapler fixation. In both study groups 30–34% of the patients felt some pain in follow-up after one year. Severity of pain was 0.60±0.62 after suture while 1.65±1.94 after stapler fixation which is statistically significant as well (p<0.007). Mean operative time was 15.33±6.33 minutes for suture fixation while 1.56±0.41 minutes for fixation by staples, p-value < 0.001.

Conclusion:

The method of fixation does not appear to cause significant difference in early post-operative pain but chronic pain is more after stapler fixation of mesh. However, operative time was reduced significantly in staple fixation group as compared to suture fixation group

Prospective cohort study on mesh shrinkage measured with MRI after laparoscopic ventral hernia repair with an intraperitoneal iron oxide-loaded PVDF mesh

BACKGROUND

Current data on shrinkage of intraperitoneal meshes come mainly from animal studies. High-quality human data in prospective studies are scarce.

METHODS

We used the ability to visualize intraperitoneal PVDF meshes enhanced with iron particles (DynaMesh IPOM visible) with magnetic resonance imaging (MRI) to determine the amount of shrinkage between 1 and 13 months postoperatively. All measurements of the width, length, and surface area of the mesh were performed with a standardized methodology independently by four radiologists blinded for the timing of the MRI.

RESULTS

Of the 15 patients undergoing laparoscopic ventral hernia repair, 13 patients received an MRI both at 1 and at 13 months. Evaluation of inter-rater reliability between the radiologists showed intra-class correlations of 0.95 (95% CI 0.92-0.98) for the width, 0.96 (95% CI 0.93-0.98) for the length, and 0.99 (90% CI 0.99-1.00) for the surface area of the mesh. The change between measurement at implantation and 1-month MRI was - 0.7 cm (P = 0.023; - 3.6%) for the width and - 1.9 cm (P = 0.001; - 7.2%) for the length. The change between 1 and 13 months was - 0.06 cm (P = 0.74; shrinkage = 0.3%) for the width, - 0.12 cm (P = 0.56; shrinkage = 0.5%) for the length, and - 4.0 cm² (P = 0.20; shrinkage = 1.0%) for the surface area of the mesh.

CONCLUSION

There is excellent inter-rater reliability between radiologists when measuring width, length, and surface area of visible intraperitoneal PVDF mesh with MRI. There is no significant shrinkage between 1 and 13 months of intraperitoneal PVDF mesh after laparoscopic ventral hernia repair.