Relationship between tissue ingrowth and mesh contraction

Mesh shrinkage after transabdominal preperitoneal inguinal hernia repair

Synthetic mesh is now used for inguinal hernia repair in most cases. It is well known that the indwelling mesh contracts after placement in the body, regardless of the material. The aim of this study was to develop a method for indirect measurement of the mesh area postoperatively that allows for easy comparison with the condition of the mesh immediately after surgery. X-ray-impermeable tackers were used to fix the mesh, and changes of the indwelling mesh after surgery were measured indirectly using two mesh materials. This study involved 26 patients who underwent inguinal hernia repair with a polypropylene or polyester mesh (13 patients each). Polypropylene showed a stronger tendency to shrink, but there was no significant difference between the materials. For both materials, some patients showed relatively strong shrinkage and others showed relatively weak shrinkage. The group with the strong shrinkage had significantly higher body mass index. The results of the present study showed that mesh surly shrinked over time and there was no adverse effect of mesh shrinkage on the patients outcomes in this population. Mesh would shrink over time regardless of the sort of mesh but it did not affect the patients outcomes.

Losartan modifies mesh integration after abdominal wall repair: an experimental study

PURPOSE

Angiotensin II (AT II) receptor blockers have previously shown to reduce inflammatory response in many settings. We aimed to assess the effects of ATII receptor blocker (Losartan) on mesh integration after abdominal wall repair in a rat model.

METHODS

A total of 16 Wistar-Kyoto (WKY) and 16 previously hypertensive (SHRSP) rats were isolated. An acute ventral hernia followed by a bridged repair with heavyweight polypropylene mesh was performed. Subjects received either normal saline (WKY-C n = 8 and SHRPS-C n = 8) or 40 mg/kg losartan (WKY-L n = 8) and SHRPS-L n = 8) in the postoperative period. Blood pressure was recorded preoperatively and weekly after surgery. Necropsy with en-bloc resection of the abdominal wall was performed at postoperative day 30. Macroscopic and microscopic evaluations of the specimens were conducted. H&E and Masson's trichrome were used for histologic evaluation.

RESULTS

Both groups receiving Losartan showed a significant reduction of blood pressure after surgery (WKY-L: 130/85 vs 116/81 mmHg, SHRPS-L: 176/137 vs 122/101 mmHg, p < 0.01). A significant reduction in mesh incorporation and adherence scores were also observed on macroscopic analysis in Losartan groups (p < 0.01 and p   = 0.02, respectively). Microscopically, higher immature fibroplasia was observed after Losartan, with a significant reduction in scar plate formation and inflammatory response on the prosthetic surface (p = 0.04 and p  = 0.02, respectively).

CONCLUSION

Losartan modifies the interaction between the host tissue and the prosthesis. An impairment in mesh integration and immature fibroplasia in both normotensive and hypertensive rats detected in our model warrants further research.

Mesh shrinkage is the potential pathogenesis of chronic somatic pain following transabdominal preperitoneal repair: Report of two cases

Although mesh-related pain, termed "somatic pain," is a well-known pain syndrome following Lichtenstein repair, few reports are available on somatic pain following transabdominal preperitoneal repair (TAPP) and its pathogenesis remains unclear. We report on two patients with refractory somatic chronic pain following TAPP. In the present two cases, both mesh fixation with rigid permanent metal tackers and mesh shrinkage resulting in contractile forces on the groin musculature could be considered as potential mechanisms in the etiology of chronic somatic pain following TAPP. The lessons learned from these two cases are: (a) mesh shrinkage resulting in contractile forces on the groin musculature could be considered as potential mechanisms in the etiology of chronic somatic pain following TAPP; (b) partial mesh removal would be an effective alternative to total mesh removal in those patients for remedial surgery.

Laparoscopic latero-abdominal colposuspension: Description of the technique, advantages and preliminary results

INTRODUCTION

There are currently various fixation or suspension techniques for pelvic organ prolapse (POP) surgery. Laparoscopic colposacropexy is considered the gold standard. We present the surgical steps of the laparoscopic latero-abdominal colposuspension (LACS) technique and the preliminary results obtained.

MATERIAL AND METHODS

Patients with anterior and/or apical compartment symptomatic POP undergoing LACS are included. The Baden-Walker scale, the Overactive Bladder Questionnaire-Short Form (OAB-q SF), the Pelvic Organ Prolapse/Urinary Incontinence Sexual Questionnaire (PISQ-12) and the Patient Global Impression of Improvement (PGI-I) scale were used to assess the degree of prolapse, urinary filling and sexual symptoms and the level of satisfaction before and after surgery, respectively. Conventional laparoscopic material and a polyvinylidene fluoride (PVDF) mesh were used.

RESULTS

Eighteen patients were included with a minimum follow-up time of 6months. The mean surgical time was 70.3±23.8min. Anatomic correction of prolapse was seen in all cases. Only one recurrence was detected. High levels of patient satisfaction were achieved.

CONCLUSION

LACS allowed the anatomical reconstruction of the pelvic floor and proved to be a minimally invasive, fast, effective, safe and reproducible technique. More series are needed to evaluate its role against laparoscopic colposacropexy.

Efficacy of robotic versus open transversus abdominis release in a porcine model

PURPOSE

Transversus abdominis muscle release (TAR) combines retromuscular mesh placement with posterior component separation and muscle release. TAR is usually an open technique for abdominal wall reconstruction; however, several centers have performed this operation robotically and claim better clinical outcomes when compared to open surgery. We sought to compare robotic versus open TAR utilizing a porcine model.

METHODS

Animals were randomized to open versus robotic TAR with mesh placement, survived for 4 weeks, then underwent diagnostic laparoscopy to assess adhesive burden and adhesion tenacity. T-peel testing was utilized to assess mesh ingrowth. The primary outcome was adhesive burden; secondary outcomes included mesh incorporation, contraction, and operative time.

RESULTS

Nine robotic and eight open TARs were performed. Mean operative time was significantly shorter for the open cases compared to robotic cases (88.6 ± 12.9 min versus 228.3 ± 46.2, p < 0.01). Operative time in the robotic arm of the study decreased over time, from 300 to 165 min. No difference was seen in the mean adhesion area between the two groups. Adhesion tenacity and mesh flatness were similar. The work required to peel the mesh off surrounding tissue was significantly higher in the open TAR than in the robotic TAR group: 52.6 ± 15.5 and 32.9 ± 10.6 mJ/cm2, respectively (p < 0.01).

CONCLUSIONS

There were no differences in adhesions between the robotic and open approaches, but greater mesh contraction and ingrowth was observed in the open TAR group. Though operative time was longer in the robotic group, time dropped by about 40% from the first case to the last.

Long-term follow-up of endoscopic totally extraperitoneal direct inguinal hernia repair using the Endoloop technique

INTRODUCTION

The pre-tied suture Endoloop™ technique for plication of the weakened transversalis fascia is efficient in post-operative seroma prevention, after laparoscopic/endoscopic direct inguinal hernia repair. No studies have evaluated long-term tolerability of this new technique in regards to chronic pain and hernia recurrence.

METHODS

Prospective longitudinal evaluation study of consecutive patients treated with Endoloop™ for M2 or M3 direct defects, during endoscopic totally extraperitoneal approach. Meshes were secured with fibrin sealant only. All patients had a minimum 2.8 years (median 5.9 years) follow-up. First outcome was chronic groin/testicular pain; secondary outcome parameters included hernia recurrence and Quality of Life (QoL). Patients were assessed by phone interview using the validated Carolinas Comfort Scale (CCS), questioned regarding recurrence and asked to present for clinical review as needed.

RESULTS

112 patients (median age 57 years) with 141 direct hernia defects were included during the study period of 2008-2014. An Endoloop™ was used on 127 occasions-79 M2 and 48 M3 direct hernias. One patient had an early recurrence requiring an open repair and was therefore excluded. Thirty-three of the remaining one hundred and eleven patients (29.7%) were lost to long-term follow-up. According to their CCS range, 70 patients (88.6%) were very satisfied with their results, 8 (10.1%) were satisfied, and only one patient (1.3%) who reported chronic groin pain was unsatisfied. There was no reported long-term hernia recurrence.

CONCLUSION

The PDS Endoloop™ technique for closure of direct inguinal hernia defects is well tolerated with low risk of hernia recurrence, chronic pain, and excellent QoL. This reliability persists to long-term follow-up.

Surgical perspectives regarding application of biomaterials for the management of large congenital diaphragmatic hernia defects

This review focuses on the surgical viewpoints on patch repairs in neonates with large congenital diaphragmatic hernia defects. The main focus  is on the various biomaterials that have been employed to date with regard to their source of origins, degradation properties as well as tissue integration characteristics. Further focus  is on the present knowledge on patch integration when biomaterials are placed in the diaphragmatic defect. The review will also look at the present evidence on the biomechanical characteristics of the most commonly used biomaterials and compares these materials to diaphragmatic tissue to offer more  insight on the present practice of patch repairs in large defects. Since tissue engineering and regenerative medicine has offered another dimension to diaphragmatic replacement, a detailed overview of this technology will be undertaken with regard to cell sourcing, scaffolds, in vitro versus in vivo implants as well as quality of tissue produced, to explore the limitations and the feasibility facing the scientific community in its clinical implementation of skeletal muscle-engineered tissue beyond laboratory research for diaphragmatic replacement.

Effects of suture tecnique on mesh shrinkage

OBJECTIVE

Polypropylene meshes are one of the most frequently used patches in inguinal hernia repairs. This material was proved to be not completely inert, and may cause inflammatory responses like foreign body reactions. One of the physical results of these inflammatory reactions against the mesh is mesh shrinkage which is responsible for recurrence and pain. In this study, we aimed to investigate the effects of the suture technique on mesh shrinkage.

METHODS

36 animals were used for the study. Subjects were divided into 3 groups. In the first group the mesh (onlay) was not fixated by any means. In the second group, mesh was placed on the abdomen wall, after which the mesh was fixated with interrupted suturing. In the third group, continuous suturing was applied after the placement of the mesh. Mesh shrinkage was measured macroscopically, and the mesh site reaction was evaluated microscopically. At the end of the second month, 18 subjects were sacrificed again to conduct the same procedure.

RESULTS AND CONCLUSION

When meshes are used for hernia repairs, shrinkage may be observed in meshes placed on fascia. In the first group without mesh fixation, mesh shrinkage was more significant in the second month compared to the first month. The amount of shrinkage of without fixation group was found to significantly differ during the second month from interrupted and continuous suture groups. Even though statistically not significant, fixation of the mesh with interrupted sutures seems to be more advantageous compared to fixation with continuous sutures.

Modifying hernia mesh design to improve device mechanical performance and promote tension-free repair

PURPOSE

Approximately 348,000 ventral hernia repairs are performed annually in the United States and the incisional hernia recurrence rate is approximately 20% as a result of suture and mesh device failure. Device failure is related to changes at the suture/tissue interface that leads to acute or chronic suture pull-through and surgical failure. To better manage mechanical tension, we propose a modified mesh design with extensions and demonstrate its mechanical superiority.

METHODS

Comparative uniaxial static tensile testing was conducted on polypropylene suture and a modified mesh. Subsequently, a standard of care (SOC) mesh and modified mesh were evaluated using a tensometer in an acute hernia bench-top model.

RESULTS

Modified mesh breaking strength, extension knot breaking strength, extension disruption, and extension anchoring were superior to suture (p < .05). Modified mesh ultimate tensile strength of anchoring was superior to SOC mesh (p < .05). Various stitch patterns and modifications in device design significantly improved device tension-free performance far beyond clinically relevant benchmarks (p < .05).

CONCLUSIONS

Testing demonstrates that the modified mesh outperforms SOC mesh and suture in all tested failure modes. SOC hernia mesh tears through tissue at stress levels below maximum physiologic stress, whereas, the modified hernia mesh is up to 200% stronger than SOC mesh at resisting suture tearing through tissue and maintains anchoring at stresses far beyond clinically relevant benchmarks. Modifying hernia mesh design significantly improves device mechanical performance and enhances tension-free repair.

Biomimetic implants for pelvic floor repair

BACKGROUND

Polypropylene implants are used for the reconstructive surgery of urogynaecological disorders like pelvic organ prolapse, but severe complications associated with their use have been reported. There is evidence that surface properties and a difference in mechanical stiffness between the implant and the host tissue contribute to these adverse events. Electrospinning is an innovative engineering alternative that provides a biomimetic microstructure for implants, resulting in a different mechano-biological performance.

AIM

The main objective of this review is to inform about the potential of electrospun matrices as an alternative modality for pelvic floor repair.

METHODS

Publications with the following studies of electrospun matrices were reviewed: (i) the technique; (ii) in vitro use for soft tissue engineering; (iii) in vivo use for reconstruction of soft tissues in animals; and (iv) clinical use in humans.

RESULTS

Electrospun matrices provide a synthetic mimic of natural extracellular matrix (ECM), favoring cellular attachment, proliferation and matrix deposition, through which a proper, low-inflammatory tissue-implant interaction can be established. Electrospun sheets can also be created with sufficient mechanical strength and stiffness for usage in prolapse surgery.

CONCLUSION

Electrospun matrices mimic the structural topography of the extracellular matrix and can be functionalized for better biological performance. As such, they have great potential for the next generation of urogynecological implants. However, their long-term safety and efficacy must still be established in vivo.

Long-term retromuscular and intraperitoneal mesh size changes within a randomized controlled trial on incisional hernia repair, including a review of the literature

Abstract

Purpose Ingrowth of fibroblasts in a polypropylene mesh may cause contraction and a later recurrence. We assessed mesh contraction in intraabdominal and retromuscular implantation after incisional hernia repair.

Methods

A cohort of patients within an RCT on laparoscopic (LHR) versus open hernia repair (OHR) had their mesh borders marked with metal clips. X-ray was performed on postoperative day 1 and after 1 year. Total length, width, and dislocation were measured. A tacker fixated large-pore polypropylene mesh was used in LHR, and a retromuscular small-pore heavy-weight mesh was sutured to the midline in OHR. Patient’s pain was assessed before surgery and after 1 year.

Results

For analysis 37/47 patients remained: 20 LHR and 17 OHR. Hernia defect area was median 41 cm² in LHR and 25 cm² in OHR (p < 0.140). Implanted mesh size was 300 cm² for LHR and 240 cm² for OHR (p < 0.341). After 1 year the mesh area decreased by 4.4% and 0.5% in LHR and OHR, respectively (p < 0.063). Longitudinal distance decreased by 2.8% in LHR and by 2.6% in OHR (p < 0.269). Transverse distance decreased by 1.6% in LHR but increased by 3.1% in OHR (p < 0.005). Dislocation was seen in four LHR and one OHR. Two recurrent and one port-site hernia were diagnosed after LHR. Measurements between observers were identical in 58% and consensus was made in the remainder. Pain was not correlated to mesh area change.

Conclusions

Mesh contraction after 1 year is not a clinical issue for an intraperitoneal large-pore mesh or a retromuscular small-pore mesh. It is not correlated to postoperative pain.

Recombinant human lubricin for prevention of postoperative intra-abdominal adhesions in a rat model

BACKGROUND

Postoperative intra-abdominal adhesions are a major cause of morbidity and mortality and contribute to a heavy burden on health care resources. At present, numerous introduced adhesion prevention products have demonstrated some benefit but none are consistently effective. The aim of this study was to examine the effectiveness of recombinant human lubricin in preventing intra-abdominal adhesion formation.

MATERIALS AND METHODS

A total of 62 male Wistar Albino rats were randomly assigned to the study. Six rats were used to the initial pilot study and 56 rats were randomized into four groups: (1) control cecal abrasion; (2) treatment cecal abrasion with 0.5 mg/mL lubricin solution; (3) control cecal enterotomy and primary closure; and (4) treatment cecal enterotomy and primary closure with 0.5 mg/mL lubricin solution. Rats were sacrificed at 3 d and 21 d postoperatively for the pilot and main studies, respectively. Macroscopic and microscopic adhesion severity was graded by blinded investigators.

RESULTS

For the pilot study, all six rats successfully reached the end point indicating safety of the lubricin gel. In the main randomized study, adhesions in the treated cecal abrasion group were significantly reduced both macroscopically (P = 0.001) and microscopically (fibrosis P = 0.009, inflammation P < 0.0001), when compared with the control group. In the cecal enterotomy group, adhesions were reduced for the treatment group in macroscopic (P = 0.011) and microscopic grading (fibrosis P = 0.500, inflammation P = 0.206) compared with the control group.

CONCLUSIONS

Recombinant human lubricin significantly reduced both macroscopic and microscopic intra-abdominal adhesions in the cecal abrasion group. The cecal enterotomy group showed modest macroscopic adhesion reduction. Future study using higher concentration of lubricin solution are needed to investigate its toxicity and more profound antiadhesion properties in significant operations.

In vitro analysis of biopolymer coating with glycidoxypropyltrimethoxysilane on hernia meshes

Certain coatings may improve the biocompatibility of hernia meshes. The coating with self-assembled monolayers, such as glycidoxypropyltrimethoxysilane (GOPS) can also improve the materials characteristics of implants. This approach was not yet explored in hernia meshes. It was the aim of this work to clarify if and how hernia meshes with their three-dimensional structure can be coated with GOPS and with which technique this coating can be best characterized. Commercially available meshes made from polypropylene (PP), polyester (PE), and expanded polytetrafluorethylene (ePTFE) have been coated with GOPS. The coatings were analyzed via X-ray photoelectron spectroscopy (XPS), confocal laser scanning microscopy (CLSM), and cell proliferation test (mouse fibroblasts). Cell viability and cytotoxicity were tested by MTT test. With the GOPS surface modification, the adherence of mouse fibroblasts on polyester meshes and the proliferation on ePTFE meshes were increased compared to noncoated meshes. Both XPS and CLSM are limited in their applicability and validity due to the three-dimensional mesh structure while CLSM was overall more suitable. In the MTT test, no negative effects of the GOPS coating on the cells were detected after 24 h. The present results show that GOPS coating of hernia meshes is feasible and effective. GOPS coating can be achieved in a fast and cost-efficient way. Further investigations are necessary with respect to coating quality and adverse effects before such a coating may be used in the clinical routine. In conclusion, GOPS is a promising material that warrants further research as coating of medical implants. © 2016 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 105B: 1083-1090, 2017.

Synthetic surgical meshes used in abdominal wall surgery: Part I-materials and structural conformation

Surgical implants are commonly used in abdominal wall surgery for hernia repair. Many different prostheses are currently offered to surgeons, comprising permanent synthetic polymer meshes and biologic scaffolds. There is a wide range of synthetic meshes currently available on the market with differing chemical compositions, fiber conformations, and mesh textures. These chemical and structural characteristics determine a specific biochemical and mechanical behavior and play a crucial role in guaranteeing a successful post-operative outcome. Although an increasing number of studies report on the structural and mechanical properties of synthetic surgical meshes, nowadays there are no consistent guidelines for the evaluation of mechanical biocompatibility or common criteria for the selection of prostheses. The aim of this work is to review synthetic meshes by considering the extensive bibliography documentation of their use in abdominal wall surgery, taking into account their material and structural properties, in Part I, and their mechanical behavior, in Part II. The main materials available for the manufacture of polymeric meshes are described, including references to their chemical composition, fiber conformation, and textile structural properties. These characteristics are decisive for the evaluation of mesh-tissue interaction process, including foreign body response, mesh encapsulation, infection, and adhesion formation. © 2015 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 105B: 689-699, 2017.

Materials characterization of explanted polypropylene hernia mesh: Patient factor correlation

This study quantitatively assessed polypropylene (PP) hernia mesh degradation and its correlation with patient factors including body mass index, tobacco use, and diabetes status with the goal of improving hernia repair outcomes through patient-matched mesh. Thirty PP hernia mesh explants were subjected to a tissue removal process followed by assessment of their in vivo degradation using Fourier transform infrared, differential scanning calorimetry, and thermogravimetric analysis analyses. Results were then analyzed with respect to patient factors (body mass index, tobacco use, and diabetes status) to determine their influence on in vivo hernia mesh oxidation and degradation. Twenty of the explants show significant surface oxidation. Tobacco use exhibits a positive correlation with modulated differential scanning calorimetry melt temperature and exhibits significantly lower TGA decomposition temperatures than non-/past users. Chemical and thermal characterization of the explanted meshes indicate measurable degradation while in vivo regardless of the patient population; however, tobacco use is correlated with less oxidation and degradation of the polymeric mesh possibly due to a reduced inflammatory response.

Short-term results of open inguinal hernia repair with self-gripping Parietex ProGrip mesh in China: A retrospective study of 90 cases

OBJECTIVES

This study investigated short-term outcomes of Lichtenstein hernia repair using self-gripping Parietex ProGrip mesh in Chinese patients with inguinal hernias.

METHODS

Retrospective analysis of patients undergoing Lichtenstein hernia repair using the Parietex ProGrip mesh at a single hospital in China between July 2012 and June 2013. All patients completed the EuroQol-five dimensions (EuroQoL-5D) and short form-36 questionnaires and were followed up at 1 day, 7 days, 1 month. and 6 months, postoperatively.

RESULTS

Ninety cases (66 males, 24 females) were studied. Mean ± standard deviation (SD) patient age was 48.7 ± 16.8 (range, 21-87) years. Most hernias were Gilbert's type II (23%) or III (31%). During 6 months of follow-up, none of the patients had recurrent hernia or systemic postoperative complications. The mean ± SD pain visual analog scale score decreased from 32 ± 10.6 at postoperative Day 1 to 0.67 ± 2.5 at 6 months. From postoperative Day 1 to 6 months, there were marked improvements in health and health-related quality of life; mean ± SD visual analog scale EuroQoL score increased from 55.3 ± 8 to 95.2 ± 3 and mean ± SD HR EuroQoL score from 0.31 ± 0.07 to 0.95 ± 0.02. At 6 months, mean scores in all eight dimensions of the short form-36 questionnaires had increased from baseline.

CONCLUSION

The use of self-fixating Parietex ProGrip mesh in open inguinal hernia repair is simple, rapid, effective, and safe, and is associated with low postoperative pain and improved quality life among patients.

New minimally invasive technique of parastomal hernia repair - methods and review

INTRODUCTION

Parastomal hernia is described as the most common complication in patients with ostomy. It is reported that its incidence varies from 3% to 39% for colostomies and 0 to 6% for ileostomies. Surgical repair remains the treatment of choice. There are three types of surgical treatment - fascial repair, stoma relocation and repair using prosthetic mesh via a laparoscopic or open approach. Recently there have been several meta-analyses and systematic reviews aiming to compare the results of surgical treatment, and the authors agreed that the quality of evidence precludes firm conclusions.

AIM

To describe the novel concept of parastomal hernia repair - HyPER/SPHR technique (hybrid parastomal endoscopic re-do/Szczepkowski parastomal hernia repair) and its early results in 12 consecutive cases.

MATERIAL AND METHODS

Twelve consecutive patients were operated on due to parastomal hernia using the new HyPER hybrid technique between June 2013 and May 2014. The patients' condition was evaluated during the perioperative period, 6 weeks and then every 3 months after surgery.

RESULTS

After 6 weeks of follow-up we have not observed any mesh-related complications. All 12 patients were examined 3 months and 6 months after repair surgery for evaluation. No recurrence, stoma site infection or stoma-related problems were found. None of the patients complained of pain and none of them needed to be hospitalized again. Reported quality of life on a 0-10 scale after 6 weeks of follow-up was 8 (range: 7-10).

CONCLUSIONS

The HyPER procedure for treatment of parastomal hernias proposed by the authors is a safe and feasible surgical technique with a high patient satisfaction rate and a low number of complications. The hybrid procedure seems to be a promising method for parastomal hernia repair.

Results of bony chest wall reconstruction with expanded polytetrafluoroethylene soft tissue patch

PURPOSE

The early and long-term outcomes of bony chest wall reconstruction with expanded polytetrafluoroethylene (Gore-Tex) soft tissue patch remain a concern. No clinical study has reported the shrinkage of Gore-Tex following reconstruction to date.

METHODS

Thirty-seven patients who underwent bony chest wall reconstruction from 1994 to 2012 were retrospectively reviewed. Postoperative chest computed tomography images of 17 patients were examined, and shrinkage of reconstruction materials was measured and compared.

RESULTS

Gore-Tex was used for reconstruction in 18 patients, autologous materials were used in 14, Marlex mesh was used in four, and Medifit felt was used in one. No surgery-related deaths were observed. Twenty patients experienced early postoperative complications. Four patients experienced local infection. One patient with Marlex-mesh experienced empyema 33 days postoperatively. Chest drainage time in the Gore-Tex patients was significantly lower than in patients with other types of prosthetic reconstruction. No dislocation or dehiscence was found. Shrinkage of Gore-Tex was absent in 4 patients and acceptable in seven patients. No granulation formation was evident around the Gore-Tex, No significant difference in shrinkage was seen between the different materials used.

CONCLUSION

Chest wall reconstruction with Gore-Tex was feasible with favorable early and long-term results.

Evaluation of three purely polypropylene meshes of different pore sizes in an onlay position in a New Zealand white rabbit model

BACKGROUND

The aim of the study was to evaluate the influence of the pore size of a polypropylene mesh on the shrinkage and elasticity of the mesh-tissue complex and the inflammatory reaction to the implant in an open onlay hernia repair.

MATERIALS AND METHODS

Twenty-one 10 × 10 cm samples of polypropylene meshes of a different pore size (3.0 × 2.8 mm-PP3, 1.0 × 0.8 mm-PP1 and 0.6 × 0.5 mm-PP.5) were implanted in an onlay position in 21 New Zealand white rabbits. After 90 days of implantation the shrinkage, elasticity and foreign body reaction (FBR) were assessed.

RESULTS

The shrinkage of PP3 was 30.6 ± 4.3 %, PP1 49.3 ± 2.9 % and PP.5 49.5 ± 2.6 %. The shrinkage of PP3 was significantly lower (PP3 × PP1 p = 0.007, PP3 × PP.5 p = 0.005), PP1 and PP.5 were similar. The elasticity was similar. The strength of FBR in mesh pores was similar. The width of foreign body granuloma layers at the mesh-tissue interface was significantly reduced with increasing pore size (inner: PP3 10.1 ± 1.2; PP1 12.5 ± 2.9; PP.5 17.4 ± 5.2 and outer: PP3 21.2 ± 2.5; PP1 30.6 ± 6.3; PP.5 60.4 ± 14.9). All differences between the widths of granuloma layers were statistically significant (p < 0.010). One animal (PP1) was excluded because of a mesh infection.

CONCLUSIONS

Implantation of polypropylene mesh of a pore size of 3 mm in an onlay position is associated with a significant reduction of shrinkage in comparison to a 1 mm pore lightweight and 0.5 mm pore heavyweight mesh. A pore size increase to 3 mm is not sufficient for an improvement of mesh-tissue complex elasticity in comparison to a 1 mm pore lightweight and 0.5 mm heavyweight mesh. Polypropylene mesh with enlarged pores to 3 mm is associated with a similar strength of FBR in mesh pores and a reduced foreign body granuloma in comparison to a 1 mm pore lightweight and 0.5 mm pore heavyweight mesh.

Giant midline abdominal incisional herniae repair through combined retro-rectus mesh placement and components separation: experience from a single centre

AIMS

Giant midline abdominal wall incisional herniae require repair/reconstruction to restore the structural and functional continuity of the anterior abdominal wall. We describe here our approach to these demanding cases through a combined retro-rectus mesh placement and components separation and their overall functional outcome.

METHODS

A retrospective analysis of a prospectively collected data was carried out and 28 patients who underwent giant (≥15 cm) midline incisional hernia reconstruction were identified in a large district general hospital between 2007 and 2013 with a median follow-up of 34 (6-76) months.

RESULTS

Demographic data of our series include age of 60 (median) (30-87) years with a M:F ratio of 12:16, length of symptomatic hernia 18 (median) (12-36) months, more than two previous laparotomies (15), bowel obstructive symptoms (7) and recurrent herniation (7). BMI recorded was 32 (median) (24-46) and ASA of II (median) (I-III). Co-morbidities included cardiac disease (6), diabetes (6), respiratory disease (4) and systemic immunocompromise (2). Operative and technical details showed operative duration to be 180 (median) min, cranio-caudal rectus sheath defect 21 (median) cm, transverse rectus sheath defect 15 (median) cm, cross-sectional area of fascial defect 300 (median) cm(2) and size of mesh 690 (median) cm(2). Seven (25 %) developed short-term post operative complications: grade I seromata all resolving spontaneously (5); grade II superficial wound infections (2). Twenty-five (89 %) were completely asymptomatic at 34 (median) months' follow-up; 2 (7 %) reported mild pain, but not limiting any activity; 1 (4 %) described pain occasionally limiting activity. There was no clinical recurrence with one patient developing global bulging.

CONCLUSIONS

Our series is comparable to the literature in patient cohort demographics, co-morbidity and risk factor profile; however, we demonstrate an excellent intermediate term outcome with no clinical recurrence and an improvement in quality of life, through their ability to perform normal day to day activities.

Preventing intraperitoneal adhesions with linezolid and hyaluronic acid/carboxymethylcellulose: a comparative study in cecal abrasion model

BACKGROUND

We aimed to compare the effectiveness of linezolid in preventing intraperitoneal adhesions with hyaluronic acid + carboxymethylcellulose (Seprafilm).

METHODS

Thirty rats were divided randomly into 3 groups: Group I (control), untreated; Group II (Seprafilm); and Group III (linezolid). All rats were sacrificed on the 14th day after surgery. Macroscopic adhesion, inflammation, and fibrosis were evaluated.

RESULTS

The multiple comparisons between groups showed a statistically significant difference for adhesion. There were statistically significant differences between Group I and II and I and III, but no statistically significant difference between Group II and III. The multiple comparisons between the groups showed a statistically significant difference for inflammation and fibrosis. For inflammation and fibrosis, there was a statistically significant difference between Group I and II and I and III, but no statistically significant difference between Group II and III.

CONCLUSION

The efficiency of linezolid in reducing the formation of intraperitoneal adhesions was statistically significant compared with the control group.

Biocompatibility and tissue integration of a novel shape memory surgical mesh for ventral hernia: in vivo animal studies

Approximately 400,000 ventral hernia repair surgeries are performed each year in the United States. Many of these procedures are performed using laparoscopic minimally invasive techniques and employ the use of surgical mesh. The use of surgical mesh has been shown to reduce recurrence rates compared to standard suture repairs. The placement of surgical mesh in a ventral hernia repair procedure can be challenging, and may even complicate the procedure. Others have attempted to provide commercial solutions to the problems of mesh placement, but these have not been well accepted by the clinical community. In this article, two versions of shape memory polymer (SMP)-modified surgical mesh, and unmodified surgical mesh, were compared by performing laparoscopic manipulation in an acute porcine model. Also, SMP-integrated polyester surgical meshes were implanted in four rats for 30-33 days to evaluate chronic biocompatibility and capacity for tissue integration. Porcine results show that the modified mesh provides a controlled, temperature-activated, automated deployment when compared to an unmodified mesh. In rats, results indicate that implanted SMP-modified meshes exhibit exceptional biocompatibility and excellent integration with surrounding tissue with no noticeable differences from the unmodified counterpart. This article provides further evidence that an SMP-modified surgical mesh promises reduction in surgical placement time and that such a mesh is not substantially different from unmodified meshes in chronic biocompatibility.

Low-density polypropylene meshes coated with resorbable and biocompatible hydrophilic polymers as controlled release agents of antibiotics

The application of bioactive meshes in abdominal surgery for the repair of hernias is an increasing clinical activity in a wide sector of the population. The main secondary effect is the appearance of infections from bacteria, specifically Staphylococcus aureus and S. epidermidis. This paper describes the development and application of low-density polypropylene meshes coated with a biocompatible and resorbable polymer as a controlled release system of the antibiotic vancomycin. The polymeric coating (a non-cross-linked copolymer of 2-hydroxyethyl methacrylate and 2-acrylamido-2-methylpropanesulfonic acid) has a thickness of 14-15μm and contains 0.32mgcm(-2) of the antibiotic vancomycin. The in vitro experiments demonstrate the excellent inhibitory character of the coated meshes loaded with the antibiotic, following the standard protocol of inhibition of halo in agar diffusion test. This inhibitory effect is maintained for a relatively long period (at least 14days) with a low concentration of antibiotic. The acrylic polymer system regulates the release of the antibiotic with a rate of 24μgh(-1), due to its slow dissolution in the medium. Experiments in vivo, based on the implantation of coated meshes, demonstrate that the system controls the infection in the animal (rabbits) for at least 30days. The concentration of antibiotic in the blood stream of the rabbits was below the detection limit of the analytical technique (<1-2μgml(-1)), which demonstrates that the antibiotic is released in the local area of the implant and remains concentrated at the implantation site, without diffusion to the blood stream. The systems can be applied to other medical devices and implants for the application of new-generation antibiotics in a controlled release and targeted applications.

Mesh fixation with fibrin sealant during endoscopic totally extraperitoneal inguinal hernia approach: a review of 640 repairs

PURPOSE

Endoscopic repair of inguinal hernia can decrease the incidence of chronic groin pain. Staple mesh fixation is the surgical technique preferentially used but may also cause residual pain. Although a substantial number of specialists advocate no mesh fixations, concerns are that this could lead to an increase in recurrence rates. This study aimed to assess the safety and the effectiveness of fibrin sealant, as an alternative technique to staple mesh fixation after totally extraperitoneal (TEP) inguinal hernia repair.

METHODS

A total of 472 patients underwent elective TEP inguinal hernia repair between February 2005 and July 2011. Mesh fixation was achieved using fibrin sealant. Patients were reviewed postoperatively at Week 2, Week 6, and Month 6. Patient satisfaction was assessed in a subgroup of 116 patients using a comprehensive scoring system designed for hernia repairs, and pain was assessed using a standard Visual Analog pain Scale.

RESULTS

No conversion to open surgery was observed. There were two cases of major morbidities and no mortality. Three months after surgery, only three patients (0.6 %) experienced chronic groin or testicular discomfort. At Week 6, 98.9 % of the patients were either satisfied or very satisfied with their outcome, and 96.8 % denied any residual pain. Finally, only six hernia recurrences (0.9 %) were reported, of which five occurred during the first months of the study.

CONCLUSIONS

Fibrin sealant is safe and reliable for mesh fixation of inguinal hernia during TEP repair with a very high satisfaction index and limited risk of developing chronic pain.

History of methicillin-resistant Staphylococcus aureus (MRSA) surgical site infection may not be a contraindication to ventral hernia repair with synthetic mesh: a preliminary report

PURPOSE

A history of methicillin-resistant Staphylococcus aureus (MRSA) surgical site infection presents a significant surgical dilemma as to the risk of subsequent mesh infection, even if no active infection is present. We investigated the outcomes of ventral hernia repair with synthetic mesh in patients with prior MRSA surgical site infections (SSIs).

METHODS

All patients with a clean wound but prior MRSA SSI undergoing open ventral hernia repair with mesh by a single surgeon over a 3-year period were reviewed for the development of any major (need for readmission, operative debridement, or mesh removal) or minor SSI. All patients received peri-operative intravenous vancomycin and prolonged suppressive oral trimethoprim/sulfamethoxazole or doxycycline.

RESULTS

Ten patients (male = 7, female = 3) with clean wounds and a history of MRSA SSI underwent open ventral hernia repair with retrorectus synthetic mesh placement. Mean follow-up was 13.5 ± 3.3 months. Overall, two patients (20 %) developed SSIs (minor = 2, major = 0). Both SSIs were successfully managed with therapeutic oral antibiotics and local wound care without need for surgical debridement or mesh removal. There have been no hernia recurrences in any of the patients.

CONCLUSIONS

Preliminary results suggest that history of MRSA infection may not be a contraindication to the use of synthetic mesh for ventral hernia repair. Macroporous lightweight meshes, combined with use of prolonged suppressive antibiotics and sublay retromuscular mesh placement that provides complete tissue coverage, should be further investigated as an acceptable prosthetic choice when planning a complex ventral hernia repair in the setting of prior MRSA SSI.

Reconstructive laparoscopic prolapse surgery to avoid mesh erosions

Introduction: The objective of the study is to examine the efficacy of the purely laparoscopic reconstructive management of cystocele and rectocele with mesh, to avoid the risk of erosion by the graft material, a well known complication in vaginal mesh surgery.

Material and methods: We performed a prospective, single-case, non-randomized study in 325 patients who received laparoscopic reconstructive management of pelvic organe prolaps with mesh. The study was conducted between January 2004 and December 2012 in a private clinic in India. The most common prolapse symptoms were reducible vaginal lump, urinary stress incontinence, constipation and flatus incontinence, sexual dysfunction and dypareunia. The degree e of the prolaps was staged according to POPQ system. The approach was purely laparoscopic and involved the use of polypropylene (Prolene) or polyurethane with activated regenerated cellulose coating (Parietex) mesh.

Results: The mean age was 55 (30–80) years and the most of the patients were multiparous (272/325). The patients received a plastic correction of the rectocele only (138 cases), a cystocele and rectocele (187 cases) with mesh. 132 patients had a concomitant total hysterectomy; in 2 cases a laparoscopic supracervical hysterectomy was performed and 190 patients had a laparoscopic colposuspension. The mean operation time was 82.2 (60–210) minutes. The mean follow up was 3.4 (3–5) years. Urinary retention developed in 1 case, which required a new laparoscopical intervention. Bladder injury, observed in the same case was in one session closed with absorbable suture. There were four recurrences of the rectocele, receiving a posterior vaginal colporrhaphy. Erosions of the mesh were not reported or documented.

Conclusion: The pure laparoscopic reconstructive management of the cystocele and rectocele with mesh seems to be a safe and effective surgical procedure potentially avoiding the risk of mesh erosions.

Complications of synthetic slings used in female stress urinary incontinence and applicability of the new IUGA-ICS classification

OBJECTIVES

To analyze different complications of synthetic suburethral slings, and to apply the new "IUGA-ICS classification of complications directly related to the insertion of prosthesis (meshes, implants, tapes) and grafts in female pelvic floor surgery" to the list of complications, check its applicability, and give suggestions regarding possible improvements.

STUDY DESIGN

This study is an analysis of complications of synthetic suburethral slings. Data on type of complication, time interval between the insertion of the prosthesis and the onset of symptoms of complication, type and nature of prosthesis, and management process were documented. Additional descriptions of the sling position in relation to lower urinary tract, shrinkage or prominence of the prosthesis, and intra-operative nature of the prosthetic material were collected for analysis.

RESULTS

From the year 2003 to 2010, 376 women with complications of synthetic suburethral slings were managed surgically and the data were analyzed. Overactive bladder (OAB) at 54%, lower urinary tract obstruction (48%), vaginal exposure (19%), and pain (14%) were the most frequent complications. Infection, fistulae, urinary tract penetration, and groin/thigh pain were other complications. The new IUGA-ICS classification could be applied to most of the types of complications, a notable exception being de novo development of overactive bladder. Also category 4B of IUGA-ICS classifications encompasses a wide clinical variety of complications and may need reconsideration.

CONCLUSION

De novo OAB seems to be the commonest complication of synthetic suburethral slings, followed by obstruction, vaginal exposure, and long term pain. The new IUGA-ICS classification on complications has good general applicability; some minor changes may be useful in the future.

Ventral hernia repair with synthetic, composite, and biologic mesh: characteristics, indications, and infection profile

BACKGROUND

A variety of mesh materials are available for ventral hernia repair (VHR), each with a unique set of characteristics. Surgeons are offered an ever-expanding selection of products, making a review of the available materials timely.

METHODS

Current surgical literature is reviewed to describe the different types of synthetic mesh, the indications for the use of each type, their relative risks of infection, and other benefits and shortcomings. We also review clinical studies demonstrating outcomes, efficacy, and use of the meshes in different surgical settings, including laparoscopic hernia repair and special situations such as infection or large abdominal wall defects.

RESULTS

Three main types of prosthetic mesh are available. Synthetic mesh, such as polypropylene (PP) or polyester, is characterized by high tensile strength and vigorous tissue ingrowth, but is unsuitable for intra-abdominal placement because of its tendency to induce bowel adhesions. Composite, or barrier-coated, mesh is a dual-sided prosthetic having a synthetic parietal side to promote a strong repair and a visceral surface that repels tissue ingrowth and decreases adhesion formation. Biologic mesh is a collagen-based human, porcine, or bovine scaffold that may be implanted in the extra- or intra-peritoneal position. Biologic mesh is used frequently in the setting of infected or contaminated surgical incisions.

CONCLUSIONS

Synthetic PP mesh is an appropriate, durable material for extra-peritoneal placement in uncomplicated, clean VHR. Expanded polytetrafluoroethylene and composite meshes are suitable for intraperitoneal placement during laparoscopic VHR. Biologic meshes may be appropriate for contaminated fields or other special situations, but there is no consensus on when or how to use them.

Biocompatibility comparison of novel soft tissue implants vs commonly used biomaterials in a pig model

OBJECTIVE

To develop a model to evaluate biocompatibility, integration, and substrate independence of novel porous bioscaffolds for maxillofacial and plastic reconstruction using sphere-templated angiogenic regeneration technology compared with currently available synthetic and biologic soft tissue implants.

STUDY DESIGN

A prospective pilot study using animals.

SETTING

Military medical center.

SUBJECTS AND METHODS

Five pigs underwent dorsal subcutaneous implantation of a polypropylene-based material coated with precision pore silicone granules (sphere-templated scaffold), expanded polytetrafluoroethylene, human dermis, and porcine dermis. Sham and undissected sites were also used as controls. Specimens were harvested 7, 21, 90, and 180 days after surgery and evaluated histologically for inflammation, neovascularization, and collagen deposition.

RESULTS

All materials and sham sites induced a mild to moderate inflammation that decreased over time, except for human dermis, which elicited a moderate to severe inflammatory response. The responses were varied and measurable using subjective scoring methods. The sphere-templated scaffold demonstrated numerous foreign body giant cells adjacent to the silicone granules, which were not seen in any of the other specimens.

CONCLUSION

Subjective scoring of pathology slides and measurement of capsule thickness appeared to show differences between the materials, but these differences require a larger number of subjects and proper statistical analysis to assess. The robust foreign body reaction elicited by the polypropylene/silicone-based scaffold argues against the use of this material in future studies. The authors advocate using inert biodegradable substances for future bioscaffold constructs.

Laparoscopic ventral hernia repair: does primary repair in addition to placement of mesh decrease recurrence?

BACKGROUND

The advent of laparoscopic ventral hernia repair (LVHR) not only reduced the morbidity associated with open repair but also led to a decrease in the hernia recurrence rate. However, the rate continues to remain significant.

METHODS

A retrospective observational study was conducted on 193 patients who were treated with LVHR by two minimally invasive surgeons in a 24-month period. The patient population was broadly divided into two groups based on the laparoscopic repair of the fascial defect with mesh underlay, or with primary suture repair and mesh underlay (PSR + MU). Patient demographics, rates of hernia recurrence, and other associated complications were compared between the two groups. Patient variables and the clinical outcomes were analyzed with descriptive statistics and chi-square test.

RESULTS

One hundred ninety-three consecutive patients underwent LVHR for incisional (n = 136), umbilical (n = 44), epigastric (n = 9), and parastomal (n = 4) hernia. Hernia recurrence was documented in eight patients (4.1%). The mean follow-up period was 10.5 months (range 1-36 months). Incisional hernias accounted for all eight recurrences. The rate of recurrence in those treated with PSR + MU was 3% (two of 67 cases) in comparison with 4.8% (six of 126 patients) associated with mesh alone. The rate of recurrence in the recurrent hernia group, treated with mesh only, was 10.5% (four of 38 patients) compared with 4.8% (one of 21 patients) in the PSR + MU group.

CONCLUSIONS

Primary laparoscopic repair along with mesh placement for the management of ventral hernia was found to be effective in selected cases as evidenced by the low rate of recurrence when compared with conventional laparoscopic repair with mesh alone. Further retrospective and prospective studies, with larger patient enrollment, are warranted to confirm the benefit of this technique over traditional repair.

Evaluation of composite mesh for ventral hernia repair

INTRODUCTION

Composite mesh prostheses incorporate the properties of multiple materials for ventral hernia repair. This study evaluated a polypropylene/ePTFE composite mesh with a novel internal polydioxanone (PDO) absorbable ring.

METHODS

Composite mesh was placed intraperitoneally in 16 pigs through an open laparotomy and explanted at 2, 4, 8, and 12 weeks. Intraabdominal adhesions were measured laparoscopically. Host tissue in-growth was assessed histologically and tensiometrically. Degradation of the internal PDO ring component was also measured tensiometrically. Appropriate statistical tests were used, and P ≤.05 indicated significance.

RESULTS

No adhesions were formed in 50% of the grafts explanted at 8 weeks and 25% of grafts explanted at 12 weeks. There were significantly more vascular structures at 8 weeks, 73.5 ± 28, compared with 2 weeks, 6.75 ± 2 (P ≤.01). The T-peel force at the mesh-host tissue interface was not significantly different among time points. The absorbable PDO ring underwent complete degradation by 12 weeks.

CONCLUSIONS

This composite mesh was associated with minimal intraabdominal adhesions, progressive in-growth of host tissues, and complete degradation of a novel internal PDO ring that aided mesh positioning. This composite hernia mesh showed a favorable performance in a porcine model of open ventral hernia repair.

NiTiNol hernia device stability in inguinal hernioplasty without fixation

BACKGROUND AND OBJECTIVE

To determine whether the NiTiNol frame of a novel hernia repair device utilizing polypropylene mesh for inguinal hernioplasty remains stable and intransient without fixation after a minimum of 6 months.

METHODS

Twenty patients had 27 inguinal hernias repaired using a novel hernia repair device that has a NiTiNol frame without any fixation. Initial single-view, postoperative X-rays were compared with a second X-ray obtained at least 6 months later. The NiTiNol frame, which can be easily visualized on a plain X-ray, was measured in 2 dimensions, as were anatomic landmarks. The measurements obtained and the appearances of the 2 X-rays were compared to determine the percentage of change in device size and device stability with regard to device location and shape.

RESULTS

There were minimal changes noted between the 2 sets of measurements obtained with an overall trend towards a slight increase in the size of the hernia repair device. The devices demonstrated intransience of position and stability of shape.

CONCLUSIONS

The NiTiNol frame of a novel hernia repair device utilizing polypropylene mesh exhibits radiographic evidence of size and shape stability and intransience of position without fixation when used in inguinal hernioplasty after a minimum follow-up of 6 months.

Tension free open inguinal hernia repair using an innovative self gripping semi-resorbable mesh

AIMS

Inguinal hernia repair according to Lichtenstein technique has become the most common procedure performed by general surgeons. Heavy weight polypropylene meshes have been reported to stimulate inflammatory reaction responsible for mesh shrinkage when scar tissue evolved. Additionally, some concerns remain regarding the relationship between chronic pain and mesh fixation technique. In order to reduce those drawbacks, we have developed a new mesh for anterior tension free inguinal hernia repair which exhibits self-gripping absorbable properties.

MATERIALS AND METHODS

52 patients (69 hernias) were prospectivly operated with this mesh (SOFRADIM-France) made of low-weight isoelastic large pores knitted fabric which incorporated resorbable micro hooks that provides self gripping properties to the mesh during the first months post-implantation. The fixation of the mesh onto the tissues is significantly facilitated. The mesh is secured around the cord with a self gripping flap. After complete tissular ingrowth and resorption of the PLA hooks, the low-weight (40 g/m(2)) polypropylene mesh insures the long term wall reinforcement.

RESULTS

Peroperativly, no complication was reported, the mesh was easy to handle and to fix. Discharge was obtained at Day 1. No perioperative complication occurred, return to daily activities was obtained at Day 5.5. At one month, no neurological pain or other complications were described.

CONCLUSIONS

Based on the first results of this clinical study, this unique concept of low density self gripping mesh should allows an efficient treatment of inguinal hernia. It should reduce postoperative complications and the extent of required suture fixation, making the procedure more reproducible.

Influence of mesh materials on the expression of mediators involved in wound healing

The use of synthetic mesh for ventral hernia repair is widely accepted, but mesh-induced inflammatory responses may lead to postoperative complications. Molecular mechanisms that direct the extent of the foreign body reaction to implanted materials are poorly understood. This study compares the influence of three macroporous meshes on the expression of genes critical for wound healing and extracellular matrix remodeling in a rat model. Full thickness abdominal wall defects were corrected with polypropylene, polyester, polytetrafluoroethylene (PTFE), or suture repair with no mesh. Explants were harvested 7 or 90 days after repair and were divided for histological, immunohistochemical, and mRNA analyses. Real-time quantitative polymerase chain reaction arrays were used to profile the expression of 84 genes involved in angiogenesis at the tissue-mesh interface. Evaluation of gene expression profiles and histologic specimens revealed that polypropylene and polyester induced a greater and more persistent inflammatory response than PTFE, which elicited a response most similar to that induced by suture repair. Mesh implantation induced the differential expression (>3-fold change and p < .01) of genes encoding inflammatory cytokines, growth factors, and extracellular matrix proteins relative to suture repair without mesh. Genes most markedly upregulated included the neutrophil chemoattractant CXCL2 and matrix metalloproteinases 3 and 9. Polyester induced the greatest number of differentially expressed genes relative to suture repair both at 7 and 90 days after implantation. Results from this study suggest that the particular type of mesh used in a hernia repair may affect the patient's wound healing response and clinical outcome.

A review of available prosthetics for ventral hernia repair

OBJECTIVE

To review mesh products currently available for ventral hernia repair and to evaluate their efficacy in complex repair, including contaminated and reoperative fields.

BACKGROUND

Although commonly referenced, the concept of the ideal prosthetic has never been fully realized. With the development of newer prosthetics and approaches to the ventral hernia repair, many surgeons do not fully understand the properties of the available prosthetics or the circumstances that warrant the use of a specific mesh.

METHODS

A systematic review of published literature from 1951 to June of 2009 was conducted to identify articles relating to ventral hernia repairs and the use of prosthetics in herniorrhaphy.

RESULTS

Important differences exist between the synthetics, composites, and biologic prosthetics used for ventral hernia repair in terms of mechanics, cost, and the ideal situation in which each should be used.

CONCLUSIONS

The use of synthetic mesh remains an appropriate solution for most ventral hernia repairs. Laparoscopic ventral hernia repair has created a niche for both expanded polytetrafluoroethylene and composite mesh, as they are suited to intraperitoneal placement. Preliminary studies have demonstrated that the newer biologic prosthetics are reasonable options for hernia repair in contaminated fields and for large abdominal wall defects; however, more studies need to be done before advocating the use of these biologics in other settings.

Open inguinal hernia repair with the use of a polyglycolic acid-trimethylene carbonate absorbable mesh: a pilot study

PURPOSE

Tension-free repair with mesh placement has become the gold standard for open inguinal hernia surgery. Traditionally, non absorbable materials have been used for mesh manufacture. The purpose of this pilot study was to evaluate the efficacy of using a totally absorbable prosthetic mesh for open inguinal hernia repair.

METHODS

Ten patients with elective inguinal hernias were set to undergo open tension-free inguinal hernia repair with the use of polyglycolic acid-trimethylene carbonate absorbable mesh. In this pilot study, we looked primarily at recurrence and chronic pain assessed 1 year after the operation, while immediate postoperative complications were also recorded.

RESULTS

All patients were discharged from the hospital the day after surgery. In three patients (30%), a Foley catheter was inserted to relieve symptoms of urinary retention. None of the patients had any immediate postoperative complication. At the 1st year follow up, none of the patients had clinical signs of recurrence. However, one patient experienced intermittent pain in the operated inguinal area.

CONCLUSIONS

Open inguinal hernia repair with the use of polyglycolic acid-trimethylene absorbable mesh proved efficient in the given patient sample. Further studies with a larger number of patients and longer follow up are needed in order to confirm the possible favourable effects of this mesh type.

Searching for the best polypropylene mesh to be used in bowel contamination

PURPOSE

There is still some concern about the use of polypropylene in case of infection or contamination. The biocompatibility of the recently introduced light-weight polypropylene meshes seems to be promising. This experimental study was designed to evaluate three different weights and pore sizes of polypropylene meshes in a contamination model.

METHODS

Thirty rabbits were operated through a pararectal incision. The abdomen, wound and mesh were contaminated with faecal fluid aspirated from the appendix. Groups of ten animals were studied according to three different pore sizes of polypropylene mesh implanted as an inlay technique: very large pore, large pore and medium pore. Five animals of each group were sacrificed on days 21 and 90. Incisional surgical site infection and microbiologic cultures on the 21st and 90th days were the main outcome measures. Tissue integration, shrinkage and biomechanical properties were also tested.

RESULTS

Two rabbits died on day 1. There were six incisional surgical site infections (21.4%). Four animals had positive cultures with no macroscopic infection. None of the surviving rabbits with very large pore mesh had clinical infection or positive microbiologic cultures. Very large pore meshes shrank significantly more on day 21. There were no differences in the tensiometric test results.

CONCLUSIONS

In our experimental model, low-weight, very large pore polypropylene meshes seem to be the best polypropylene mesh in case of intestinal contamination. These results encourage clinical investigation on the use of low-weight, very large pore polypropylene meshes in the treatment and prevention of hernias in the presence of clean-contaminated or contaminated fields.