Adverse effects of polyvinylidene fluoride-coated polypropylene mesh used for laparoscopic intraperitoneal onlay repair of incisional hernia

Open intraperitoneal onlay mesh repair with anterior component separation as a bail-out procedure in the management of complex hernias

PURPOSE

Surgical repair of complex abdominal wall hernias remains technically demanding and is widely recognized as a risk factor for unfavorable outcomes with high recurrence and morbidity rates. The objective is to assess short- and long-term complications after open intraperitoneal onlay mesh (IPOM) repair combined with bilateral anterior component separation (ACS) for large and difficult incisional hernias, alongside evaluating hernia recurrence rates.

METHODS

This retrospective analysis utilized data sourced from Hospital electronic health records and a prospective database at an academic tertiary referral center. Data collection was carried out from patients operated between January 2006 and December 2017. Eligible patients had complex incisional hernias measuring at least 10 cm in their transverse diameter and had an open IPOM repair with bilateral ACS.

RESULTS

In our study group of 45 patients, the 30-day surgical site occurrence (SSO) rate was high (37.8%), primarily consisting of superficial postoperative complications as seroma (17.8%) and wound dehiscence (6.7%). Among six patients (13.3%), wound complications escalated to chronic infected mesh-related problems, leading to complete mesh removal in four cases (8.9%) and partial mesh removal in two cases (4.4%). Regarding long-term complications, five patients (11.1%) developed enterocutaneous fistula. The recurrence rate was modest [5 out of 41 (12.2%)] over a median follow-up period of 99 months.

CONCLUSIONS

Despite a high SSO rate, application of the open IPOM technique with ACS could serve as a valuable rescue option for managing large and complex hernias, with acceptable hernia recurrence rates at long-term follow-up.

Does intraperitoneal mesh increase the risk of bowel obstruction? A nationwide French analysis

INTRODUCTION

Incisional hernias are associated with a reduced quality of life. Mesh reinforcement of the abdominal wall is the current standard for incisional hernia repair (IHR), since it reduces the risk of recurrence. The best position for the mesh remains controversial, and each position has advantages and disadvantages.

OBJECTIVE

In this nationwide population-based study, we aimed to determine whether IHR with intraperitoneal mesh is associated with an increased risk of bowel obstruction.

PATIENTS AND METHODS

Using the French hospital database (PMSI), which collects data from all public and private hospitals, two patient cohorts were created and compared. Patients having undergone a laparoscopic IHR with intraperitoneal mesh (IPOM) in 2013 or 2014 due to a laparotomy performed in the 4 previous years were the IPOM group. Patients hospitalized for any other acute disease (i.e., without IHR) in 2013 and 2014, but having a similar laparotomy in the 4 previous years were the control group. Both cohorts were followed until 2019 in search of any episode of bowel obstruction.

RESULTS

A total of 815 patients were included in the IPOM group and matched to 1630 control patients. The 5 year bowel obstruction rate was 7.36% in the IPOM group and 4.42% in the control group (p < 0.01). In the multivariate analysis, after adjustment on age and obesity, incisional hernia repair with laparoscopic IPOM increased the risk of bowel obstruction in the 5 years following surgery (HR = 1.712; 95% CI 1.208-2.427; p = 0.0025).

CONCLUSIONS

Patients having undergone laparoscopic IPOM have an increased risk of bowel obstruction compared with patients who have a similar surgical history but no IHR.

[Safety of mesh with fluoropolymer coating during intra-abdominal placement in large animals: results of the pilot study]

OBJECTIVE

When performing laparoscopic intraperitoneal hernioplasty (IPOM), endoprostheses made of fluoropolymers are often used. However, there is no data in the literature on the intra-abdominal use of inexpensive polyester prostheses with a fluoropolymer coating compared to composite implants. Thus, the aim of the pilot study was a preliminary assessment of the safety profile of FTOREX mesh endoprostheses during intra-abdominal placement in large animals.

MATERIAL AND METHODS

6 endoprostheses were installed laparoscopically intraperitoneally in each of the 3 pigs: 1) FTOREX; 2) FTOREX with a layer of carboxymethylcellulose; 3) REPEREN-16-2; 4) SYMBOTEX; 5) VENTRALIGHT ST; 6) decellularized pork peritoneum. Fixation was performed with a herniator, transfascial sutures were not used. Relaparoscopy was performed after 45 days, and withdrawal from the experiment was performed after 90 days. Performance characteristics, signs of deformation and retraction, parameters of spike formation were evaluated.

RESULTS

All the animals survived, no complications were observed. There were no clinical manifestations or behavioral reactions indicating the presence of adhesions. The most convenient to use were the SYMBOTEX and FTOREX implants (5.0 points each). By the end of the experiment, deformation and retraction were noted in both variants of the FTOREX implants and the REPEREN prosthesis. These changes were completely absent only when using the SYMBOTEX endoprosthesis. According to the number of implants with adhesions, by the end of the observation, both variants of FTOREX prostheses occupied an intermediate position between the Reference (the worst indicator) and VENTRALIGHT ST (the best indicator). However, both FTOREX endoprostheses showed the best performance among all implants in the integral assessment of adhesions, as well as in terms of parameters such as the area and appearance of adhesions, and in terms of the strength of the joints, they were second only to the VENTRALIGHT ST endoprosthesis (0.67 vs. 0.5 points). During the study, there was no reliable dependence of deformation, retraction and adhesion formation indicators on the type of implant.

CONCLUSION

The results of the pilot study showed that all the implants used did not cause any clinically significant adverse reactions or complications. FTOREX endoprostheses with their intraperitoneal installation have anti-adhesive properties that are not inferior to VENTRALIGHT ST or SYMBOTEX composite implants. However, having less rigidity, they are more often deformed and subjected to retraction.

Parastomal Hernia Repair Using a Silo Biologic Mesh

BACKGROUND

A parastomal hernia (PSH) is an enlargement of the stoma's original opening through the abdominal wall's musculature around a colostomy, ileostomy, or urostomy. Its incidence can be up to 48%. The described methods for its repair have high recurrence rate.This article presents a 3-dimensional silo technique for PSH repair (PSH-R). The aims of this technique are to enhance the structural strength of the tunnel wall, to reinforce both the sidewalls and the fascia above and below the muscular opening, and to maintain a stable stoma opening.

METHODS

All consecutive patients undergoing PSH-R with the silo technique between January 2009 and May 2018 by 2 plastic surgeons were included. The outcome parameters of interest were hernia recurrence and wound-related complications.

RESULTS

This study reports 22 patients (9 male, 13 female) with a mean age of 66.7 years and an average body mass index of 29.2. The variety of ostomy types included 10 colostomies, 7 ileostomies, and 5 urostomies. Postoperatively, there were 3 surgical site infections, 1 seroma, and 2 wound healing delays. Six patients were readmitted, 3 of those because of small bowel obstruction. These 3 cases all required reoperation, in addition to 1 operative revision for stoma retraction. During our average follow-up of 19.9 months, 3 cases of PSH recurrence were diagnosed for a recurrence rate of 13.6%.

CONCLUSIONS

This silo technique is associated with favorable complication and low recurrence rates compared with the available techniques in surgical literature. In our practice, it has established itself as a new and safe technique for complex or recurrent PSHs and should be considered in a surgeon's armamentarium. This technique has become our standard for treatment of recurrent PSHs.

Modified Laparoscopic Sugarbaker Repair of Parastomal Hernia With a Totally Extraperitoneal Technique

Purpose: Many patients develop a parastomal hernia within the first 2 years of stoma formation, and even surgical repair is associated with high recurrence rates. An intraperitoneal approach is typically used for the laparoscopic repair of parastomal hernia; it is unknown whether a totally extraperitoneal technique (TEP) is feasible. Here we describe a laparoscopic TEP approach using a modified Sugarbaker method for the repair of parastomal hernia.

Methods: Seven patients underwent parastomal hernia repair. The retrograde puncture technique was used to create the extrapneumoperitoneum, and the peritoneum was separated with a laparoscopic TEP approach; the mesh was placed using a modified Sugarbaker technique.

Results: All patients had an oncologic etiology for stoma creation. The mean (±SD) size of the hernia defect was 3.1 ± 2.7 cm and the mesh size was 303.4 ± 96.8 cm². The mean operative time was 195.5 ± 20.7 min and average length of hospital stay after surgery was 4.8 ± 2.1 days. One patient had intraoperative subcutaneous emphysema. The average follow-up time was 8.5 ± 2.7 months; mild pain occurred in 2 patients, 3 experienced seroma formation (with no special treatment required), and 1 had early intestinal obstruction (which was treated with conservative care). There was no hernia recurrence, wound complications, or infections of the surgical site or mesh during follow-up.

Conclusion: A laparoscopic TEP technique is technically challenging but feasible. Modified laparoscopic Sugarbaker repair of a parastomal hernia with the TEP technique is safe and effective, although the recurrence rate and late complications require confirmation in more cases with long-term follow-up.

Subxiphoid top-down endoscopic totally preperitoneal approach (eTPA) for midline ventral hernia repair

PURPOSE

Midline abdominal wall hernia repair is among the most common surgical interventions performed worldwide. However, the optimal surgical technique remains controversial. To overcome the disadvantages of both open and transabdominal procedures, we developed a totally endoscopic preperitoneal approach (eTPA) with placement of a large mesh.

METHODS

From December 2019 to October 2020, 20 consecutive patients with small to medium-sized midline ventral hernias underwent repair using a completely preperitoneal subxiphoid top-down approach. The preperitoneal space was entered directly below the xiphoid, and careful endoscopic development of the plane between the peritoneum and posterior sheath of the rectus fascia was then performed behind the linea alba. The hernia sac and its contents were identified and reduced. The hernia defect was closed with sutures, and a mesh with an adequate high defect: mesh ratio was placed in the newly created preperitoneal space.

RESULTS

Twenty patients were enrolled in this study, including 14 with primary umbilical hernias, 4 with primary epigastric hernias, and 2 with recurrent umbilical hernias. 15 patients suffered from a mild concomitant diastasis recti. All operations were successfully completed without conversion to open repair. The mean operative time was 105.3 min (range, 60-220 min). Postoperative pain was mild, and the mean visual analog scale score for pain was 1.8 on the first postoperative day. The average postoperative hospital stay was 1.8 days (range, 1-4 days). One patient developed a minor postoperative seroma, but it had no adverse impact on the final outcome. No patients developed recurrence during the 3- to 10-month follow-up period.

CONCLUSIONS

The subxiphoid top-down totally endoscopic preperitoneal approach (eTPA) technique is feasible and effective. It may become a valuable alternative for the treatment of primary small- (defect size < 2 cm) and medium-sized (2-4 cm) midline ventral hernias, particularly in presence of a concomitant diastasis recti.

Polymer Hernia Repair Materials: Adapting to Patient Needs and Surgical Techniques

Biomaterials and their applications are perhaps among the most dynamic areas of research within the field of biomedicine. Any advance in this topic translates to an improved quality of life for recipient patients. One application of a biomaterial is the repair of an abdominal wall defect whether congenital or acquired. In the great majority of cases requiring surgery, the defect takes the form of a hernia. Over the past few years, biomaterials designed with this purpose in mind have been gradually evolving in parallel with new developments in the different surgical techniques. In consequence, the classic polymer prosthetic materials have been the starting point for structural modifications or new prototypes that have always strived to accommodate patients’ needs. This evolving process has pursued both improvements in the wound repair process depending on the implant interface in the host and in the material’s mechanical properties at the repair site. This last factor is important considering that this site—the abdominal wall—is a dynamic structure subjected to considerable mechanical demands. This review aims to provide a narrative overview of the different biomaterials that have been gradually introduced over the years, along with their modifications as new surgical techniques have unfolded.

Endoscopic Totally Extraperitoneal Repair of Parastomal Hernia: A Case Report

A parastomal hernia is a type of incisional hernia that occurs in abdominal integuments in the proximity of a stoma. It is a frequent late complication following colostomy. Surgical repair is currently the only treatment option for parastomal hernia. Here we present the case of a 74-year-old patient with parastomal hernia and a history of open surgery treated with a totally extraperitoneal (TEP) endoscopic approach. There was no recurrence of the hernia at the 3-month follow-up. We discuss the feasibility and possible operative approaches for endoscopic repair of parastomal hernia with the TEP technique.

Laparoscopic Versus Open Incisional Hernia Repair: Long-Term Follow-up Results of a Randomized Clinical Trial

PURPOSE

Long-term extension of a previous randomized controlled clinical trial comparing open (OVHR) vs. laparoscopic (LVHR) ventral hernia repair, assessing recurrence, reoperation, mesh-related complications and self-reported quality of life with 10 years of follow-up.

METHODS

Eighty-five patients were followed up to assess recurrence (main endpoint), reoperation, mesh complications and death, from the date of index until recurrence, death or study completion, whichever was first. Recurrence, reoperation rates and death were estimated by intention to treat. Mesh-related complications were only assessed in the LVHR group, excluding conversions (intraperitoneal onlay; n = 40). Quality of life, using the European Hernia Society Quality of Life score, was assessed in surviving non-reoperated patients (n = 47).

RESULTS

The incidence rates with 10 person-years of follow-up were 21.01% (CI 13.24-33.36) for recurrence, 11.92% (CI: 6.60-21.53) for reoperation and 24.88% (CI 16.81-36.82) for death. Sixty-two percent of recurrences occurred within the first 2 years of follow-up. No significant differences between arms were found in any of the outcomes analyzed. Incidence rate of intraperitoneal mesh complications with 10 person-years of follow-up was 6.15% (CI 1.99-19.09). The mean EuraHS-QoL score with 13.8 years of mean follow-up for living non-reoperated patients was 6.63 (CI 4.50-8.78) over 90 possible points with no significant differences between arms.

CONCLUSION

In incisional ventral hernias with wall defects up to 15 cm wide, laparoscopic repair seems to be as safe and effective as open techniques, with no long-term differences in recurrence and reoperation rates or global quality of life, although lack of statistical power does not allow definitive conclusions on equivalence between alternatives.

TRIAL REGISTRATION NUMBER

ClinicalTrial.gov (NCT04192838).

Development of electrospun core-shell polymeric mat using poly (ethyl-2) cyanoacrylate/polyurethane to attenuate biological adhesion on polymeric mesh implants

Poly (ethyl-2) cyanoacrylate was used to create an adhesion-free biocompatible non-woven material reinforced by polyurethane core via a co-axial electrospinning set-up. The effect of relative humidity (RH) of (18, 30, 40, 60, and 68) % on the electrospinning process was examined, and found that in order to achieve well defined core-shell fiber structure, the optimal RH was 18%. If the RH is >18%, a phenomenon called Taylor cone cyclic destabilization occurs, which results in unfavorable surface and mechanical properties of the mat. The developed composite electrospun mat has the potential to be used in medical devices, such as repairing the viscera layer for intraperitoneal hernia mesh implants, which require the attenuation of biological elements, and adequate mechanical properties.

Re-do surgery after prosthetic abdominal wall repair: intraoperative findings of mesh-related complications

INTRODUCTION

Mesh repair is one of the most popular technique for the treatment of abdominal wall hernias, resulting in lower recurrence rates. However, it is associated with a high risk of mesh-related complications. The aim of the present study is to assess the impact of biomaterials on the intra-abdominal organs, in terms of adhesions and visceral complications, in a series of patients undergoing re-do surgery at our abdominal wall unit.

MATERIALS AND METHODS

We reviewed the clinical records of 301 patients who undergone laparotomy between June 2008 and May 2018, selecting 67 patients with one or more previous prosthetic abdominal wall repair (AWR).

RESULTS

The average number of previous repairs was 1.6 with a mean time interval of 66 months from the last repair. Clinical presentation included hernia recurrence (69%), mesh infection (26%), infection and recurrence (10%), and fistula (1%). Adhesions were intraoperatively observed in all patients, except for eight cases. Mesh was completely removed in 43 patients, partially in four. Postoperative complications were observed in 39% of cases, including wound dehiscence, hematoma, seroma, and mesh infection.

CONCLUSIONS

Long-term implant results in abdominal wall repair and are not completely known, and literature is still lacking on this topic. Re-do surgery for subsequent pathological events may represent a way to increase our knowledge.

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.

Endoscopic totally extraperitoneal approach (TEA) technique for primary ventral hernia repair

Background

Up to now the totally extraperitoneal (TEP) technique is limited to the treatment of inguinal hernias. Applying this anatomical repair concept to the treatment of other abdominal wall hernias, we developed an endoscopic totally extraperitoneal approach (TEA) to treat primary midline ventral hernias, including umbilical and epigastric hernias, in which for mesh placement, an anatomical space is developed between the peritoneum and the posterior rectus sheath in the ventral part of the abdominal wall (preperitoneal space).

Methods

Between September 2017 and December 2019 according to the selection criterions, 28 consecutive primary midline ventral hernias were repaired using TEA. After extensive endoscopic development of the midline extraperitoneal plane, which was started in the suprasymphysic area, and reduction of the hernia sac, the hernia defect was closed and a large mesh was placed in the preperitoneal position to enforce the anterior abdominal wall.

Results

All operations were successfully performed without conversion to open surgery. The mean operation time was 103.3 min (range 85–145 min). Patient-reported postoperative pain was qualitatively mild with a mean pain visual analogue scale score of 1.9 on postoperative day 1. The average hospital stay was 1.9 days (range 1–3 days). Three patients developed minor complications and were treated with no long-term adverse effects. Readmissions within 30 days or hernia recurrences were not observed with a mean follow-up period of 18 months (range 10–27 months).

Conclusion

In selected cases, TEA is a safe and feasible minimally invasive alternative in treating primary ventral hernias. This technique preserves the anatomical and physiological structure of the abdominal wall and may significantly reduce trauma and postoperative complications. Additionally, anti-adhesion-coated meshes and fixation tackers are not required, thus being cost-effective. Further studies are necessary to proof the true clinical efficacy in comparison to well-known alternative techniques.

Análisis multicéntrico del reparo de la hernia ventral en instituciones de IV nivel, 2015-2019

Introducción. La cirugía de hernia ventral implica una situación de complejidad, dadas las múltiples variables que se deben controlar para estimar los posibles factores determinantes del éxito quirúrgico y la aparición de complicaciones. Según la literatura científica mundial, la incidencia de hernia ventral se estima entre el 10 y el 15 %, y la tasa promedio de complicaciones de esta cirugía varía entre el 10 y el 37 %. El objetivo del presente estudio fue describir la experiencia y los resultados de la cirugía de hernia ventral en dos instituciones de IV nivel, en el periodo de enero de 2015 a marzo de 2019. Métodos. Se trata de un estudio observacional, descriptivo y de cohorte histórica, de pacientes mayores de edad sometidos a corrección de hernia ventral en la Clínica Colsanitas en los últimos cinco años. Los datos se tomaron del registro estadístico de las instituciones en mención. Resultados. Se incluyeron 612 pacientes en un periodo de cinco años, la mayoría de los cuales era de sexo femenino, con sobrepeso, y predominantemente, con defectos combinados mediales; la tasa general de complicaciones fue del 20 % y, el porcentaje de infección del sitio operatorio, de 9 %; para el desarrollo de esta infección, la técnica de separación de componentes se encontró como un factor de riesgo (p=0,01; RR=2,9; IC 95% 1,32-6,5). En este estudio, no se analizó la recidiva como factor de los diferentes resultados. Conclusiones. Existen pocos datos en la literatura nacional sobre los resultados de este tipo de procedimiento quirúrgico. Es por ello que se procuró brindar a la comunidad científica los resultados de morbimortalidad de esta muestra de pacientes intervenidos por hernia ventral en los últimos cinco años.

Assessment of ideal ratio of mesh area to number of fixation tacks in laparoscopic ventral and incisional IPOM Plus hernia repair

BACKGROUND

To clarify the optimum mesh-tack ratio MTR (mesh area in cm² divided by the number of fixation tacks) in laparoscopic ventral and incisional hernia repair, we compared IPOM Plus procedures with more intensive mesh fixation to those with standard mesh fixation.

METHODS

In a retrospective cohort study, 84 patients (mean hernia width 6.6 ± 4.4 cm) intraoperatively received an intensive mesh fixation I-IPOM Plus with MTR ≤ 4:1 (e.g. ,150 cm² mesh fixed by 50 tacks) and 74 patients (mean hernia width 6.7 ± 3.4 cm) received a standard mesh fixation S-IPOM Plus with MTR > 4:1 (e.g., 150 cm² mesh fixed by 30 tacks) at a community hospital between 2014 and 2017. Outcomes in recurrence rates, immediate and chronic postoperative pain, as well as long-term functionality of the abdominal wall were then evaluated.

RESULTS

After a mean follow-up time of 34 months, a 2.3% recurrence rate in I-IPOM Plus patients and a 13.5% recurrence rate in S-IPOM Plus patients were recorded (p = 0.018). The recurrence was associated with large hernia > 10 cm (OR 3.7, 95% CI 1.3-5.4) and MTR > 5 (OR 2.4, 95% CI 1.1-3.8) in the multivariate analysis. There was a positive correlation between immediate postoperative pain intensity measured on day 7 and number of fixation tacks placed (I-IPOM Plus: mean 4.5 ± 2.5 VAS versus S-IPOM Plus: mean 2.7 ± 2.0 VAS, p = 0.001). However, there were no outcome differences in terms of length of immediate postoperative pain experience, sick leave duration, chronic pain rate and long-term abdominal wall functionality between these two groups.

CONCLUSION

For ventral and incisional hernia patients with multiple recurrence risk factors, a mesh-tack ratio MTR ≤ 4:1 should be applied in laparoscopic IPOM Plus procedures.

Robotic intraperitoneal onlay versus totally extraperitoneal (TEP) retromuscular mesh ventral hernia repair: A propensity score matching analysis of short-term outcomes

BACKGROUND

Short-term outcomes of robotic intraperitoneal onlay mesh(rIPOM) versus robotic totally extraperitoneal retromuscular mesh(rTEP-RM) ventral hernia repair were compared.

METHODS

A retrospective review of prospectively collected data of patients was conducted. A one-to-one propensity score matching(PSM) analysis was performed to achieve two well-balanced groups in terms of preoperative variables. A univariate and multivariate analysis were conducted to determine factors influencing post-operative outcomes.

RESULTS

Of 291 rIPOM and rTEP-RM procedures, 68 patients were assigned to each group after PSM. Operative times were longer for the rTEP-RM group. Adhesiolysis was more frequently required in rIPOM. The rTEP-RM allowed for a greater mesh-to-defect ratio. The rate of overall perioperative complications, Clavien-Dindo grades, and surgical site events were higher for the rIPOM group than the rTEP-RM group. The Comprehensive Complication Index® morbidity scores were lower in favor of rTEP-RM group. Adhesiolysis, rIPOM, and craniocaudal defect size were predictors for post-operative complications.

CONCLUSION

Robotic TEP-RM repair has better early postoperative outcomes for ventral hernias, suggesting that it may be preferable over robotic IPOM repair. Further studies with longer follow-up are needed.

Histopathologic Analysis of Explanted KAMRA Corneal Inlays Demonstrating Adherent Fibroconnective Tissue Scar Formation

Objective

To investigate the histologic composition of opaque membranes associated with corneal intrastromal inlays implanted for the surgical treatment of presbyopia.

Methods

This is an observational case series of KAMRA corneal inlays explanted due to the presence of adherent opaque membranes associated with peri-inlay corneal stromal haze and sent for histopathologic analysis. Routine histology was performed in addition to immunohistochemical staining with myofibroblast and keratocyte markers.

Results

Eleven explanted inlay specimens were received, of which, after histologic processing, four demonstrated suf-ficient cellular material for histopathologic analysis. The opaque membranes surrounding the explanted inlays were composed of fibroconnective tissue, and myofibroblasts (positive for smooth muscle actin immunostain) were the predominant cell type. Immunostaining for the keratocyte marker CD34 was negative, confirming that the membranes were the result of a reactive scar-tissue formation process and not simply normal corneal stroma adherent to the explant.

Conclusions

Corneal inlay implantation can lead to the formation of an adherent fibroconnective tissue membrane, suggesting keratocyte-to-myofibroblast transdifferentiation and reactive fibroconnective tissue scar formation that could potentially impact visual potential. Prospective patients should be counseled regarding the risk of this complication, as this may be associated with some risk of incomplete reversibility of the procedure.

Evaluation of synthetic reticular hybrid meshes designed for intraperitoneal abdominal wall repair: Preclinical and in vitro behavior

Introduction

Reticular hybrid meshes represent an alternative material for intraperitoneal repair of abdominal hernias. These consist of a reticular mesh coated or interwoven/knitted with inert materials. This study assesses the performance of two reticular polypropylene-containing hybrid meshes, TiMESH (coated with titanium) and DynaMesh (interwoven with polyvinylidene fluoride), in vitro, as well as their efficiency in adhesion prevention and tissue incorporation in an intraperitoneal model.

Methods

The mesothelialization capacity of TiMESH and DynaMesh was evaluated in vitro and compared to that of Surgipro (reticular bare polypropylene) and Preclude (laminar expanded polytetrafluoroethylene). Mesh fragments were placed on the intact parietal peritoneum of New Zealand white rabbits (n = 24), and laparoscopy performed 7 days post-surgery. Fourteen days post-implantation, adhesions were evaluated and host tissue incorporation, macrophage response, collagen expression (immunohistochemistry/RT-PCR) and neoperitoneum formation assessed. Adhesions and omental tissue were also examined.

Results

Mesh pores in reticular meshes were devoid of cells in the in vitro study. TiMESH, DynaMesh and Surgipro showed similar adhesion rates at 7/14 days and optimal tissue integration, with significant differences in comparison to Preclude. The greatest presence of macrophages was observed for TiMESH and was significant versus that for Preclude. Hybrid meshes revealed significantly higher collagen 1 mRNA expression in implants, with no differences in the levels of collagen 3. Omental samples from animals with a reticular mesh showed significantly greater collagen 1 mRNA levels.

Conclusions

The reticular structure of a mesh limits the formation of a continuous mesothelial monolayer in vitro, regardless of its composition. The presence of titanium as a coating or polyvinylidene fluoride interwoven with polypropylene in a reticular structure did not prevent adhesions. The hybrid meshes showed proper integration and an increase in the mRNA Col 1 levels in the implant area compared to Surgipro or Preclude.

Biomaterial Implants in Abdominal Wall Hernia Repair: A Review on the Importance of the Peritoneal Interface

Biomaterials have long been used to repair defects in the clinical setting, which has led to the development of a wide variety of new materials tailored to specific therapeutic purposes. The efficiency in the repair of the defect and the safety of the different materials employed are determined not only by the nature and structure of their components, but also by the anatomical site where they will be located. Biomaterial implantation into the abdominal cavity in the form of a surgical mesh, such as in the case of abdominal hernia repair, involves the contact between the foreign material and the peritoneum. This review summarizes the different biomaterials currently available in hernia mesh repair and provides insights into a series of peculiarities that must be addressed when designing the optimal mesh to be used in this interface.

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.

The use of a composite synthetic mesh in the vicinity of bowel - For repair and prophylaxis of parastomal hernias. Does it increase the risk of short term infective complications?

AIMS

The use of synthetic meshes in potentially infected operative fields such as in the vicinity of large bowel, is controversial. This study describes our experience with the use of a synthetic composite mesh for prophylaxis and repair of parastomal hernias.

METHODS

Data were collected retrospectively over a 7-year period from 2008 to 2015. An IPOM (DynaMesh™) was used either during the formation of the stoma to reinforce the abdominal wall around the stoma or during the surgical repair of existing parastomal hernias, using keyhole or sandwich technique. Majority of meshes were placed laparoscopically. Clinical data and outcomes any stoma wound complications were collected.

RESULTS

Forty seven patients were included with a male to female ratio of 34:13. Median age was 66 years (38-91 years) with median follow-up of 17 months (3-73 months). Twenty seven patients had a prophylactic mesh placement (PMP) around colostomy after resection of colorectal cancer. None of these patients had any wound complications. Twenty patients had repair of parastomal hernias (RPH). One patient (1/20) in this group had a superficial wound infection around the stoma site and underwent an incision and drainage. One patient developed seroma and one had parastomal wound haematoma.

CONCLUSIONS

The use of a composite synthetic mesh using a laparoscopic IPOM technique for the prophylaxis and treatment of parastomal hernias, even in a clean contaminated surgical field, is safe and feasible.

From intraperitoneal onlay mesh repair to preperitoneal onlay mesh repair

Laparoscopic repair for ventral and incisional hernias was first reported in the early 1990s. It uses intraperitoneal only mesh placement to achieve a tension-free repair of the hernia. However, in recent years, there has been greater concern about long-term complication involving intraperitoneal mesh placement. Many case reports and case series have found evidence of mesh adhesion, mesh fistulation, and mesh migration into hollow organs including the esophagus, small bowel, and large bowel, resulting in various major acute abdominal events. Subsequent management of these complications may require major surgery that is technically demanding and difficult; in such cases, laparotomy and bowel resection have often been performed. Because of these significant, but not common, adverse events, many surgeons favor open sublay repair for ventral and incisional hernias. Investigators are therefore searching for a laparoscopic approach for ventral and incisional hernias that might overcome the mesh-induced visceral complications seen after intraperitoneal only mesh placement repair. Laparoscopic preperitoneal onlay mesh is one such approach. This article will explore the fundamental of intraperitoneal only mesh placement and its problems, the currently available peritoneal visceral-compatible meshes, and upcoming developments in laparoscopic ventral and incisional hernia repair. The technical details of preperitoneal onlay mesh, as well as its potential advantages and disadvantages, will also be discussed.

Symptom load and individual symptoms before and after repair of parastomal hernia: a prospective single centre study

AIM

The symptom load and individual symptoms before and after repair of parastomal hernia were investigated.

METHOD

Stoma-related symptoms were prospectively recorded before repair of a parastomal hernia and at 10 days and 6 months postoperatively: leakage, skin problems, difficulty with the appliance, limitation of activity, difficulty with clothing, cosmetic complaints, social restriction, erratic action of the stoma, a bearing-down sensation at the site of the stoma and pain. Episodes of intermittent bowel obstruction and difficulty with irrigation were also recorded. Patients were seen at 1, 2 and 3 years and were examined for recurrent parastomal herniation.

RESULTS

Of 131 consecutive patients referred to a specialized centre for treatment of parastomal bulging, 61 underwent parastomal hernia repair. Forty-eight patients were treated with the Sugarbaker technique. Six different symptoms were present in more than half the patients before surgery. The overall symptom load decreased significantly from a median of 4 [interquartile range (IQR) 2.5-6] preoperatively to 2 (IQR 1-3) on postoperative day 10 and 1 (IQR 0-2) at 6 months, P < 0.001. The number of symptoms decreased in 93% of patients; in 5% there was no change and in 2% symptoms increased. Skin problems and leakage were the only symptoms that were not significantly reduced. The overall recurrence rate of herniation was 5/48 (10%) at a median of 12 (IQR 6-24) months.

CONCLUSION

The preoperative symptom load was high and this fell after repair in over 90% of patients. Recurrence occurred in 10% of patients within 2 years of repair. The study emphasizes the importance of detailed knowledge of the symptoms of parastomal hernia when addressing and managing patients' problems and complaints.

Prophylactic mesh use during primary stoma formation to prevent parastomal hernia

Introduction Parastomal hernia (PSH) is a common problem following stoma formation. The optimal technique for stoma formation is unknown although recent studies have focused on whether placement of prophylactic mesh at stoma formation can reduce PSH rates. The aim of this study was to systematically review use of prophylactic mesh versus no mesh with regard to occurrence of PSH and peristomal complications. Methods A systematic search was performed using PubMed, Embase™ and the Cochrane Library to identify randomised controlled trials that analysed placement of prophylactic mesh versus no mesh at time of initial surgery. Meta-analysis was performed using random effects methods. Results A total of 506 studies were identified by our search strategy. Of these, 8 studies were included, involving 430 patients (217 mesh vs 213 no mesh). Prophylactic mesh placement resulted in a significantly lower rate of PSH formation (42/217 [19.4%] vs 92/213 [43.2%]) with a combined risk ratio of 0.40 (95% confidence interval [CI]: 0.21-0.75, p=0.004). Placement of prophylactic mesh did not result in increased peristomal complications (15/218 [6.9%] vs 16/227 [7.0%]) with a combined risk ratio of 1.0 (95% CI: 0.49-2.01, p=0.990). Conclusions Prophylactic placement of mesh at primary stoma formation may reduce the incidence of PSH, without an increase in peristomal complications. However, the overall quality of the randomised controlled trials included in the meta-analysis was poor, and should prompt caution regarding the applicability of the findings of the individual studies and the meta-analysis to everyday practice.

Parietex™ Composite mesh versus DynaMesh®-IPOM for laparoscopic incisional and ventral hernia repair: a retrospective cohort study

INTRODUCTION Laparoscopic incisional and ventral hernia repair (LIVHR) is widely accepted and safe but the type of mesh used is still debated. We retrospectively compared postoperative outcomes with two different meshes commonly used in LIVHR. METHODS This is a retrospective study of patients who underwent incisional hernia repair between January 2008 and December 2010. Two meshes were used: Parietex™ Composite (Covidien, New Haven, CT, USA) and the DynaMesh®-IPOM (FEG Textiltechnik mbH, Aachen, Germany). The two groups were compared with respect to recurrence rates, incidence of seroma and intestinal obstruction. RESULTS Among the 88 patients who underwent LIVHR, 75 patients (85.2%) presented with primary incisional hernia, 10 (11.4%) presented with a first recurrence and 3 (3.4%) presented with a second recurrence. Median follow-up was 53.6 months (range 40-61 months). 12.9% of patients had recurrence in the Parietex™ Composite mesh group (n=62) in comparison to 3.8% in the DynaMesh®-IPOM mesh group (n=26; P=0.20). DynaMesh®-IPOM was associated with a significantly higher incidence of intestinal obstruction secondary to adhesions (11.5% vs. 0%, P=0.006) and lower incidence of seroma and haematoma formation compared to Parietex™ composite mesh group (0% vs. 6.4% of patients; P=0.185). CONCLUSIONS LIVHR is a safe and feasible technique. Dynamesh®-IPOM is associated with a significantly higher incidence of adhesion related bowel obstruction, albeit with a lower incidence of recurrence, seroma and haematoma formation compared with Parietex™ Composite mesh. However, there is a need for further well-designed, multicentre randomised controlled studies to investigate the use of these meshes.

Adhesion prevention in ventral hernia repair: an experimental study comparing three lightweight porous meshes recommended for intraperitoneal use

BACKGROUND

In ventral hernia repair, when prosthetic material is placed intraperitoneally, it may lead to an inflammatory reaction resulting in adhesions between the mesh and abdominal viscera. Several meshes have been developed to minimize this process. In this experimental study, the ability of different combined meshes to attenuate the adhesion formation was examined.

METHODS

Three commercially available lightweight porous combined meshes were placed intraperitoneally to repair an abdominal wall defect in rats: DynaMesh-IPOM (PVDF + PP), TiMesh (titanium-coated filament PP) and C-QUR/FX (omega-3 fatty acid-coated filament PP). The DynaMesh-CICAT (PVDF) was implanted in the control group. Adhesion formation was macroscopically evaluated and scored after 7 and 21 days.

RESULTS

All animals except two presented intra-abdominal adhesions. None of the meshes examined in the study demonstrated to prevent adhesions. C-QUR/FX reduced adhesion formation at 7 days' follow-up compared with all other meshes but by 21 days this effect was diminished. Between 7 and 21 days adhesion extension significantly decreased for TiMesh. TAS did not show significant modifications between 7 and 21 days' follow-up for each mesh.

CONCLUSIONS

The combined porous meshes tested in the present study demonstrated to reduce but not to prevent the adhesion formation, even if with some differences. Combined porous meshes could be chosen instead of simple meshes for retro-rectus preperitoneal prosthetic ventral hernia repair.

Long-term assessment of parastomal hernia prevention by intra-peritoneal mesh reinforcement according to the modified Sugarbaker technique

BACKGROUND

Parastomal hernia (PSH) is a very frequent complication after creation of a permanent colostomy. The aim of that study is to assess the safety and the long-term efficacy of an intra-peritoneal onlay mesh (IPOM) positioned at the time of primary stoma formation to prevent PSH occurrence.

MATERIALS AND METHODS

That multicentre prospective study concerned 29 consecutive patients operated for cancer of the low rectum between 2008 and 2014. There were 14 men and 15 women with a median age of 73 years (range 39-88) and a BMI of 28 (range 21-43). All the patients had potentially curative abdominoperineal excision associated with IPOM reinforcement of the abdominal wall with a round non-slit composite mesh centred on the stoma site and covering the lateralized colon according to the modified Sugarbaker technique. The major outcomes analysed were operative time, complications related to mesh and PSH incidence. Patients were evaluated at 6-month intervals for the first 2 years and thereafter annually with physical examination and CT scan control. For PSH evaluation, we used the classification of Moreno-Matias.

RESULTS

Surgery was performed by laparoscopy in 24 patients and by laparotomy in 5; 17 had a trans-peritoneal colostomy and 12 an extra-peritoneal colostomy. The median size of the mesh was 15 cm (range 12-20), the operative time 225 min. (range 123-311) and the specific time for mesh placement 15 min. (range 10-30). With a median follow-up of 48 months (range 6-88), no mesh infection or complication requiring mesh removal were recorded. No patient developed a true PSH; two of them had a type Ia PSH (only containing the bowel forming the colostomy with a sac < 5 cm) and were totally asymptomatic.

CONCLUSION

In our series, the incidence of PSH was 7 % and no specific mesh-related complication was noted. Prophylactic mesh reinforcement according to the modified Sugarbaker is an effective technique that addresses the issues related to the occurrence of PSH.

Magnetic resonance-visible meshes for laparoscopic ventral hernia repair

Background and Objectives:

We aimed to evaluate the first human use of magnetic resonance–visible implants for intraperitoneal onlay repair of incisional hernias regarding magnetic resonance presentability.

Methods:

Ten patients were surgically treated with intraperitoneally positioned superparamagnetic flat meshes. A magnetic resonance investigation with a qualified protocol was performed on postoperative day 1 and at 3 months postoperatively to assess mesh appearance and demarcation. The total magnetic resonance–visible mesh surface area of each implant was calculated and compared with the original physical mesh size to evaluate potential reduction of the functional mesh surfaces.

Results:

We were able to show a precise mesh demarcation, as well as accurate assessment of the surrounding tissue, in all 10 cases. We documented a significant decrease in the magnetic resonance–visualized total mesh surface area after release of the pneumoperitoneum compared with the original mesh size (mean, 190 cm² vs 225 cm²; mean reduction of mesh area, 35 cm²; P < .001). At 3 months postoperatively, a further reduction of the surface area due to significant mesh shrinkage could be observed (mean, 182 cm² vs 190 cm²; mean reduction of mesh area, 8 cm²; P < .001).

Conclusion:

The new method of combining magnetic resonance imaging and meshes that provide enhanced signal capacity through direct integration of iron particles into the polyvinylidene fluoride base material allows for detailed mesh depiction and quantification of structural changes. In addition to a significant early postoperative decrease in effective mesh surface area, a further considerable reduction in size occurred within 3 months after implantation.

Nanofibrous biomimetic mesh can be used for pelvic reconstructive surgery: A randomized study

BACKGROUND

Implantation of nonabsorbable polypropylene (PP) mesh in the vagina is the main surgical treatment for pelvic organ prolapse (POP); however, clinical outcomes remain controversial and far from satisfactory. In particular, reducing the exposure or erosion of vaginal implants to obtain improved functional reconstruction is challenging. There is an urgent need for the development of new materials and/or products for POP treatment. A nanofibrous biomimetic mesh was recently developed to address this issue.

OBJECTIVE

In this study, the basic properties of the newly developed mesh, including structural characteristics, mechanical properties, biological response of human umbilical cord mesenchymal stem cells in vitro, and tissue regeneration and biocompatibility in vivo, were evaluated and compared with those of Gynemesh™PS.

METHODS

Scanning electron microscopy and uniaxial tensile methods were used to evaluate microstructure and mechanical properties, respectively. Mesenchymal stem cell growth on the meshes was observed by fluorescence microscopy to visualize the expression of enhanced red fluorescent protein. Twenty-four mature female Sprague Dawley rats were randomly assigned to two groups: group 1 (nanofibrous biomimetic mesh, Medprin, Germany, n=12) and group 2 (Gynemesh(TM)PS, Ethicon, USA; n=12). The posterior vaginal wall was incised from the introitus, and the mesh was then implanted. Three implants of each type were tested for 1, 4, 8 and 12 weeks. Connective tissue organization, inflammation, vascularization, and regenerated tissue were histologically assessed.

RESULTS

The nanofibrous biomimetic mesh is a relatively heavy material and exhibited lower porosity than Gynemesh(TM)PS. The new mesh was stiffer than Gynemesh(TM)PS (p<0.001) but supported human umbilical cord mesenchymal stem cell attachment. Erosion of the grafts did not occur in any animal. The nanofibrous biomimetic mesh was encapsulated by a thicker layer of connective tissue and was associated with significantly greater inflammatory scores compared with Gynemesh(TM)PS. At 12 weeks, the vascularization of the new mesh was greater than that of Gynemesh(TM)PS (p<0.05). No significant difference in the thickness of the smooth muscle layer following implantation was observed between the two groups (p>0.05).

CONCLUSIONS

The nanofibrous biomimetic mesh is a candidate for reinforcing pelvic reconstruction. The mesh could be improved by decreasing its weight and stiffness and increasing its porosity. This mesh could serve as a carrier for stem cells in future regenerative medicine and tissue engineering research.

Adhesion Prevention Efficacy of Composite Meshes Parietex®, Proceed® and 4DryField® PH Covered Polypropylene Meshes in an IPOM Rat Model

Background: Adhesions to intraperitoneally implanted meshes (IPOM) are a common problem following hernia surgery and may cause severe complications. Recently, we showed that missing peritoneal coverage of the intestine is a decisive factor for adhesion formation and 4DryField^® PH (4DF) gel significantly prevents intestine-to-mesh adhesions even with use of uncoated Ultrapro^® polypropylene mesh (UPM). The present study investigates adhesion prevention capability of coated Parietex^® mesh (PTM) and Proceed^® mesh (PCM) in comparison to 4DF treated UPM. Methods: 20 rats were randomized into two groups. A 1.5 x 2 cm patch of PTM or PCM was attached to the abdominal wall and the cecum was depleted from peritoneum by abrasion. After seven days incidence of intestine-to-mesh adhesions was evaluated using Lauder and Hoffmann adhesion scores. Histological specimens were evaluated; statistics were performed using student's t-test. The data were compared with recently published data of 4DF treated uncoated UPM. Results: Use of PTM or PCM did not significantly diminish development of intestine-to-mesh adhesions (adhesion reduction rate PTM: 29%, p = 0.069 and PCM: 25%, p = 0.078). Histological results confirmed macroscopic finding of agglutination of intestine and abdominal wall with the mesh in between. Compared to these data, the use of UPM combined with 4DF gel reveals significantly better adhesion prevention capability (p < 0.0001) as shown in earlier studies. However, in clinical situation interindividual differences in adhesion induction mechanisms cannot be excluded by this experimental approach as healing responses towards the different materials might vary. Conclusion: This study shows that in case of impaired intestinal peritoneum coated PTM and PCM do not provide significant adhesion prevention. In contrast, use of UPM combined with 4DF gel achieved a significant reduction of adhesions. Hence, in case of injury of the visceral peritoneum, application of a polysaccharide barrier device such as 4DF gel might be considered more effective in reducing intestine-to-mesh adhesions than coated mesh devices.

Prevention of parastomal hernias with 3D funnel meshes in intraperitoneal onlay position by placement during initial stoma formation

PURPOSE

In patients with terminal ostomies, parastomal hernias (PSHs) occur on a frequent basis. They are commonly associated with various degrees of complaints and occasionally lead to life-threatening complications. Various strategies and measures have been tested and evaluated, but to date there is a lack of published evidence with regard to the best surgical technique for the prevention of PSH development.

METHODS

We conducted a retrospective analysis of prospectively collected data of eighty patients, who underwent elective permanent ostomy formation between 2009 and 2014 by means of prophylactic implantation of a three-dimensional (3D) funnel mesh in intraperitoneal onlay (IPOM) position.

RESULTS

PSH developed in three patients (3.75%). No mesh-related complications were encountered and none of the implants had to be removed. Ostomy-related complications had to be noted in seven (8.75%) cases. No manifestation of ostomy prolapse occurred. Follow-up time was a median 21 (range 3-47) months.

CONCLUSION

The prophylactical implantation of a specially shaped, 3D mesh implant in IPOM technique during initial formation of a terminal enterostomy is safe, highly efficient and comparatively easy to perform. As opposed to what can be achieved with flat or keyhole meshes, the inner boundary areas of the ostomy itself can be well covered and protected from the surging viscera with the 3D implants. At the same time, the vertical, tunnel-shaped part of the mesh provides sufficient protection from an ostomy prolapse. Further studies will be needed to compare the efficacy of various known approaches to PSH prevention.

Novel superhydrophilic poly(l-lactic acid-co-ε-caprolactone)/fibrinogen electrospun patch for rat abdominal wall reconstruction

A novel superhydrophilic hybrid scaffold was created by electrospinning a mixture of poly(l-lactic acid-co-ε-caprolactone) and formulated fibrinogen. The hybrid scaffolds possess the combined benefits of each individual component, such as moderate mechanical strength and excellent biocompatibility. In vitro studies also revealed that endothelial cells seeded on the hybrid scaffolds achieved a relatively high level of cell attachment after three days of culture and a significant increase in the proliferation rate after seven days of culture, compared with pure fibrinogen or poly(l-lactic acid-co-ε-caprolactone) scaffolds. A comparative study of hybrid and pure poly(l-lactic acid-co-ε-caprolactone) patches was performed in an abdominal wall defect model in rats. In both groups, implants degraded by six months, but muscle reconstruction was only observed in the hybrid patch group.

Coated meshes for hernia repair provide comparable intraperitoneal adhesion prevention

BACKGROUND

Laparoscopic incisional hernia repair with intraperitoneal mesh is associated with a certain degree of adhesion formation to the mesh. This experimental study examined the efficacy of several coated meshes for adhesion reduction.

METHODS

Five commercially available meshes with a layered coating were placed intraperitoneally in rats and followed up for 90 days: polypropylene and polyester meshes, both coated with absorbable collagen (Parietene Composite and Parietex Composite, respectively), and three polypropylene meshes respectively coated with absorbable omega-3 fatty acids (C-Qur Edge), absorbable cellulose (Sepramesh IP), and nonabsorbable expanded polytetrafluoroethylene (Intramesh T1). Uncoated polypropylene and collagen meshs (Parietene and Permacol, respectively) served as the control condition. Adhesions, incorporation, and tissue reaction were evaluated macro- and microscopically. Additionally, the development of the neoperitoneum was examined.

RESULTS

All the coated meshes performed equally well in terms of adhesion reduction. The collagen mesh performed comparably, but the uncoated polypropylene mesh performed significantly worse. The different coatings led to very differing degrees of inflammation. Ingrowth was observed only at the place of suture but was comparable for all the meshes except C-Qur Edge, which showed the weakest incorporation. Development of a neoperitoneum on the mesh surface occurred independently of whether an absorbable or nonabsorbable coating or no coating at all was present.

CONCLUSIONS

Commercially available meshes with a layered coating deliver comparable adhesion reduction. The physical presence of a layered coating between the intraperitoneal content and the abdominal wall seems to be more important than the chemical properties of the coating in adhesion formation.

DynaMesh® in the repair of laparoscopic ventral hernia: a prospective trial

PURPOSE

To investigate mesh-related complications in patients undergoing laparoscopic ventral hernia repair using DynaMesh®.

METHODS

In the period 1 January 2005 through 31 December 2010, 181 consecutive patients undergoing laparoscopic ventral hernia repair in our day surgery unit using DynaMesh® were entered prospectively in the National Danish Hernia Database. Data concerning abdominal reoperations after hernia repair were later collected on all 181 patients from the National Danish Health Registry. Postoperative telephone interviews were conducted estimating postoperative pain and patient satisfaction.

RESULTS

Six % (11 patients) were reoperated because of mesh-related complications. Three had small bowel obstruction and one had a colonic fistula with mesh infection, all causing bowel resection and mesh removal. Mesh-related cutaneous fistula was seen in one patient. Six patients had a symptomatic recurrence requiring reoperation. Abdominal wall hematomas were seen in two cases, while two other patients had symptomatic large seromas, of which one was drained surgically. After a median follow-up of 34 months (range 12-63) in 140 patients, 66 % were pain free (0 on the Numeric Rating Scale (NRS)). Of 26 patients with moderate to severe pain (NRS > 3) at follow-up, only 4 regretted the operation. Sixteen patients thought they had a recurrence, of these only 3 regretted the operation.

CONCLUSION

The use of DynaMesh® in laparoscopic ventral hernia repair was associated with a 6 % risk of mesh-related reoperation in a high volume setting. Despite chronic pain in 19 %, after 34 months follow-up patient satisfaction was high.

Evaluation of a knitted polytetrafluoroethylene mesh placed intraperitoneally in a New Zealand white rabbit model

BACKGROUND

The intraperitoneal application of surgical mesh remains a controversial issue because of possible complications, especially adhesion and fistula formation. This study aimed to assess the potential of a knitted polytetrafluoroethylene (PTFE) mesh for intraabdominal implantation.

METHODS

Twenty-eight 5 × 5 cm samples of knitted macroporous PTFE mesh and light-weight polypropylene mesh (LW-PP) were implanted intraperitoneally in 14 New Zealand white rabbits in a randomized manner and fixed using eight polypropylene stitches. After 90 days, the adhesion formation, adhesion score, shrinkage, strength of fixation to the abdominal wall, and histologic biocompatibility were assessed.

RESULTS

No intraoperative or anesthesia-related complications or mesh infection were recorded. The average area covered by adhesions was 4.7 ± 7.2% for the PTFE and 36.4 ± 36.1% for the LW-PP. The median adhesion score was 0 for the PTFE and 8 for the LW-PP. Shrinkage was 36.9 ± 12.9% for the PTFE mesh and 12.6 ± 8.72% for the LW-PP. The mesh-to-abdominal wall fixation strength was almost the same for both materials (PTFE 3.6 ± 1.9 vs. LW-PP 3.6 ± 2.9). The inflammatory cell count was almost the same for the two groups, with no statistically significant difference. The width of the inner granuloma was equal (PTFE 10.5 ± 0.9 vs. LW-PP 11.1 ± 0.9). The outer granuloma was reduced significantly in the PTFE group (PTFE 23.0 ± 2.1 vs. LW-PP 33.6 ± 7.9). One of the animals in the PTFE group died on postoperative day 12 because of ileus. The reason was an adhesion of the small intestine to the polypropylene fixation stitch, which caused small intestine strangulation.

CONCLUSIONS

The knitted PTFE mesh induces fewer intraperitoneal adhesions of lower density than the light-weight polypropylene mesh. The strength of the knitted PTFE mesh fixation to the abdominal wall is comparable with that of the light-weight polypropylene mesh, but the shrinkage is greater. The biocompatibility of the knitted PTFE mesh is comparable with that of the light-weight polypropylene implant.

An elastomeric patch electrospun from a blended solution of dermal extracellular matrix and biodegradable polyurethane for rat abdominal wall repair

A biodegradable elastomeric scaffold was created by electrospinning a mixed solution of poly(ester urethane)urea (PEUU) and porcine dermal extracellular matrix (dECM) digest, with PEUU included to provide elasticity, flexibility, and mechanical support and dECM used to enhance bioactivity and biocompatibility. Micrographs and differential scanning calorimetry demonstrated partial miscibility between PEUU and dECM. With greater dECM content, scaffolds were found to possess lower breaking strains and suture retention strength, although initial modulus was greater with higher dECM concentrations. The hybrid scaffolds containing 0% to 50% dECM had tensile strengths of 5 to 7 MPa, breaking strains of 138% to 611%, initial moduli of 3 to 11 Mpa, and suture retention strengths of 35 to 59 MPa. When hydrated, scaffolds were found to contract markedly with 50% dECM content. When used in a rat full-thickness abdominal wall replacement model, no herniation, infection, or tissue adhesion was observed after 4 and 8 weeks with a scaffold containing 25% dECM or a control 100% PEUU scaffold. Scaffolds incorporating dECM were significantly thicker at the time of explant, with greater numbers of associated smooth muscle actin-positive staining cells than in the control, but minimal cellular infiltration and remodeling of the scaffold were detected regardless of dECM addition. The processing of dECM and PEUU from a mixed solution thus provided a scaffold with evidence of better bioactivity and with mechanical properties not achievable with digested dECM alone.