Incisional hernia treatment with polypropylene graft: results of 10 years

Polypropylene-based composite mesh versus standard polypropylene mesh in the reconstruction of complicated large abdominal wall hernias: a prospective randomized study

PURPOSE

To compare polypropylene mesh positioned onlay supported by omentum and/or peritoneum versus inlay implantation of polypropylene-based composite mesh in patients with complicated wide-defect ventral hernias.

METHODS

This was a prospective randomized study carried out on 60 patients presenting with complicated large ventral hernia in the period from January 2012 to January 2016 in the department of Gastrointestinal Surgery unit and Surgical Emergency of the Main Alexandria University Hospital, Egypt. Large hernia had an abdominal wall defect that could not be closed. Patients were divided into two groups of 30 patients according to the type of mesh used to deal with the large abdominal wall defect.

RESULTS

The study included 38 women (63.3 %) and 22 men (37.7 %); their mean age was 46.5 years (range, 25-70). Complicated incisional hernia was the commonest presentation (56.7 %).The operative and mesh fixation times were longer in the polypropylene group. Seven wound infections and two recurrences were encountered in the propylene group. Mean follow-up was 28.7 months (2-48 months).

CONCLUSIONS

Composite mesh provided, in one session, satisfactory results in patients with complicated large ventral hernia. The procedure is safe and effective in lowering operative time with a trend of low wound complication and recurrence rates.

Carbon nanotubes as VEGF carriers to improve the early vascularization of porcine small intestinal submucosa in abdominal wall defect repair

Insufficient early vascularization in biological meshes, resulting in limited host tissue incorporation, is thought to be the primary cause for the failure of abdominal wall defect repair after implantation. The sustained release of exogenous angiogenic factors from a biocompatible nanomaterial might be a way to overcome this limitation. In the study reported here, multiwalled carbon nanotubes (MWNT) were functionalized by plasma polymerization to deliver vascular endothelial growth factor₁₆₅ (VEGF₁₆₅). The novel VEGF₁₆₅-controlled released system was incorporated into porcine small intestinal submucosa (PSIS) to construct a composite scaffold. Scaffolds incorporating varying amounts of VEGF₁₆₅-loaded functionalized MWNT were characterized in vitro. At 5 weight percent MWNT, the scaffolds exhibited optimal properties and were implanted in rats to repair abdominal wall defects. PSIS scaffolds incorporating VEGF₁₆₅-loaded MWNT (VEGF–MWNT–PSIS) contributed to early vascularization from 2–12 weeks postimplantation and obtained more effective collagen deposition and exhibited improved tensile strength at 24 weeks postimplantation compared to PSIS or PSIS scaffolds, incorporating MWNT without VEGF₁₆₅ loading (MWNT–PSIS).

A modified sublay-keyhole technique for in situ parastomal hernia repair

OBJECTIVE

The surgical treatment of a parastomal hernia is always challenging due to the high incidence of recurrence following primary repair, or stoma relocation and severe morbidities in prosthetic repair with polypropylene materials. We therefore developed a modified sublay-keyhole technique employing a polypropylene material to minimize the associated high risk of the procedure. We herein describe our initial clinical experience with this modified procedure.

METHODS

A retrospective review was performed to obtain the clinical data for 11 patients with parastomal hernias who underwent the modified in situ Sublay-keyhole repair from November 2008 to August 2010.

RESULTS

The mean hernia size was 58.7 cm(2) (range 30-96 cm(2)), with an average polypropylene mesh size of 376.3 cm(2) (range 270-464 cm(2)). The mean length of the operation was 147.9 min (range 120-195.0 min), and the mean postoperative hospital stay was 11 days (range 9-14 days). All patients had an uneventful incisional recovery, with no infections. Two seromas and one hematoma were found and treated with conservative management, such as with aspiration, physical therapy and compression. All patients had been followed up, with a mean length of follow-up of 23.5 months (range 11-39 months). One parastomal hernia recurrence was seen 11 months postoperatively. Breakdown of the sutures and an over-sized aperture cut in the mesh were detected as the causes of the recurrence during the secondary repair procedure. Only re-sutures in both the mesh aperture and myofascial dehiscence were executed for this patient, and no re-recurrence was observed during an additional follow-up of 15 months. No recurrence of the parastomal hernia or presentation of an incisional hernia was detected during the follow-up.

CONCLUSIONS

The modified Sublay-keyhole repair appears to be an effective procedure for parastomal hernias, with a low incidence of recurrence and risk of morbidities. Collection of more cases and further follow-up examinations will be needed to confirm our findings.

Which mesh for hernia repair?

INTRODUCTION

The concept of using a mesh to repair hernias was introduced over 50 years ago. Mesh repair is now standard in most countries and widely accepted as superior to primary suture repair. As a result, there has been a rapid growth in the variety of meshes available and choosing the appropriate one can be difficult. This article outlines the general properties of meshes and factors to be considered when selecting one.

MATERIALS AND METHODS

We performed a search of the medical literature from 1950 to 1 May 2009, as indexed by Medline, using the PubMed search engine (www.pubmed.gov). To capture all potentially relevant articles with the highest degree of sensitivity, the search terms were intentionally broad. We used the following terms: 'mesh, pore size, strength, recurrence, complications, lightweight, properties'. We also hand-searched the bibliographies of relevant articles and product literature to identify additional pertinent reports.

RESULTS AND CONCLUSIONS

The most important properties of meshes were found to be the type of filament, tensile strength and porosity. These determine the weight of the mesh and its biocompatibility. The tensile strength required is much less than originally presumed and light-weight meshes are thought to be superior due to their increased flexibility and reduction in discomfort. Large pores are also associated with a reduced risk of infection and shrinkage. For meshes placed in the peritoneal cavity, consideration should also be given to the risk of adhesion formation. A variety of composite meshes have been promoted to address this, but none appears superior to the others. Finally, biomaterials such as acellular dermis have a place for use in infected fields but have yet to prove their worth in routine hernia repair.

Retraction and fibroplasia in a polypropylene prosthesis: experimental study in rats

BACKGROUND

The treatment of hernia, independent of anatomical site and technique utilized, generally involves using prostheses, which may cause complications, despite their unarguable advantage in allowing safe reinforcement. An example of this is possible retraction, which causes discomfort and hernia recurrence. Polypropylene is still the most often used biomaterial of the great number available. The purpose of this study is to evaluate the amount of retraction of the polypropylene mesh, as well as the histological reactions that accompany this phenomenon.

METHODS

Polypropylene meshes (Marlex) were inserted in an anterior position to the whole abdominal aponeurosis of 25 Wistar rats (Rattus norvegicus albinus). The animals were divided into groups and another intervention was performed 7, 28, and 90 days later to measure the dimensions of the prostheses and to calculate the final area. Histological analysis was performed with hematoxylin-eosin to evaluate neutrophils, macrophages, giant cells, and lymphocytes surrounding the mesh threads in ten random fields of each slide.

RESULTS

Seven days after the mesh was inserted, the mean rate of retraction was 1.75% (P = 0.64); at 28 days, it was 3.75% (P = 0.02); and at 90 days, it was 2.5% (P = 0.01). As to the histological analysis, there was a total decline of neutrophils and a progressive increase of macrophages, giant cells, and lymphocytes proportional to the post-implant time of the mesh (P < 0.05).

CONCLUSION

There was a statistically significant retraction of 3.75% at 28 days and 2.5% at 90 days after the prosthesis was inserted. There is a well-established sequence of cellular events which aim at synthesizing new connective tissue to reinforce the mesh.

How safe is the use of prosthetic materials in the repair of abdominal-wall defects in malnourished subjects?

Incisional hernias and abdominal-wall defects consume large amounts of healthcare resources. Use of mesh is effective in treatment of these disorders and can decrease the rate of recurrence. This experimental study focused on the safety of mesh use in the setting of malnutrition, a condition that impairs wound healing. Rats were divided into two groups: normally fed and food-restricted. An abdominal-wall defect, 2 by 2 cm, was covered with polypropylene mesh, 2.5 by 2.5 cm. After sacrifice of the rats at the 21st and 60th days, tissue samples were sent for tensiometric and histopathological studies. No significant difference in infectious complications was observed between the two groups. Tensiometry revealed no significant differences between the groups. On histopathological examination, the only difference noted was in the vascularization scores of normally fed rats. For malnourished subjects that survived after surgery, the use of polypropylene mesh appeared safe in the closure of abdominal-wall defects, with no increase in infection rate and satisfactory wound healing.

The role of suture fixation on mesh contraction after abdominal hernia repair

Mesh contraction is a threat for hernia repair. Our aim is to analyze the effects of fixation techniques on mesh contraction. Forty-eight rats with abdominal wall defects were equally divided into four groups (G): G1 (control) with no repair, G2 defects were repaired with free polypropylene mesh, and G3 and G4 defects were reinforced with prolene mesh fixed by running and interrupted sutures, respectively. The corners of the defect and prolene mesh were marked with silver clips. The contraction rate was calculated by radiological measurement of distances between corner clips and by measuring the mesh areas after harvesting abdominal wall containing the patch. Host reaction was histhopathologically and biochemically examined by inflammation score, fibroblast count, thickness of the granulation tissue, and tissue hydroxyproline level. Distances between corner clips and mesh area have decreased by 31.5% and 26.4% respectively in G2, while in G3 the decrease was 24.4% (p = .008) and 22% (p = .01), respectively. Granulation tissue thickness was highest in the group with mesh fixed by running suture. The tissue hydroxyproline levels were similar in mesh repair groups. Our study suggests that mesh contraction, which reduces mesh surface, occurs during the wound healing process. In order to decrease the contraction rate, it is important to keep the mesh in place until its incorporation into the surrounding tissue. Our results suggest that mesh contraction is minimized by suture fixation, and running fixation suture, which provides more balanced tension around the mesh, seems more beneficial for decreasing contraction rate.