Evaluation of sepramesh biosurgical composite in a rabbit hernia repair model

BACKGROUND: In cases such as incisional hernia repair, polypropylene mesh (PPM) can be exposed to the underlying viscera and cause adhesions to the mesh. In this study, a composite prosthesis that was designed to be less susceptible to adhesion formation than PPM was evaluated in a rabbit incisional hernia repair model. MATERIALS AND METHODS: A 5 x 7-cm full-thickness defect was created in the abdominal wall of 30 female New Zealand White rabbits. Ten animals each were repaired with PPM, Bard Composix (PP/ePTFE), or Sepramesh biosurgical composite-a polypropylene mesh coated on one side with chemically modified sodium hyaluronate and carboxymethylcellulose (HA/CMC). The animals were sacrificed after 28 days and the overall performance, including adhesion formation and tissue integration by histology and mechanical testing, was evaluated. RESULTS: In the Sepramesh group, there was a significant reduction in the percentage of surface area covered by adhesions and a significant increase in the percentage of animals with no adhesions compared to standard materials. The tissue integration strength and overall cellular response were similar in all groups. A partially remesothelialized peritoneal surface was often apparent overlying the Sepramesh implant. CONCLUSIONS: Sepramesh biosurgical composite effectively repaired abdominal wall defects in rabbits and reduced adhesion development to the mesh compared to the use of a PPM and a PP/ePTFE composite.     

Experimental Evaluation of a New Layered Prosthesis Exhibiting a Low Tensile Modulus of Elasticity: Long-term Integration Response within the Rat Abdominal Wall

The use of a new type of prosthesis, Bard Composix (BC), constructed of two layers of polypropylene mesh (PP) and one layer of expanded polytetrafluoroethylene (ePTFE), could provide a good solution for hernia repair when both minimal adhesions and maximum collagenous infiltration are necessary. We experimentally evaluated long-term stability of this composite. In 15 Sprague-Dawley rats, a full thickness defect was created in the anterior abdominal wall and repaired with BC. Studies were performed over implantation intervals of 2, 4, and 6 months in strips obtained from the prosthesis-host tissue interfaces. Light microscopy, environmental scanning electron microscopy (ESEM), immunohistochemistry, and tensiometry were used. Overall findings provide evidence that PP and ePTFE association renders the alloy well suited for hernia repair, promoting a robust and durable alloplast-soft tissue union. At all points studied, the patch was well tolerated and meshes did not shrink, come loose, or migrate. Neovascularization continued 6 months after implantation. Ex vivo mechanical characterization demonstrated that the primary advantage of the new device stems from a low modulus of elasticity, a property that can be exploited to enhance mechanical load transfer from prosthetic materials to the relatively frail surrounding tissues. After implantation, adequate tensile strength and a low modulus of elasticity were detected in the restored zone, conferring great adaptability to the abdominal wall. In conclusion, the BC layered prosthesis proved suitable for implantation in abdominal wall defects, exhibiting favorable biocompatibility and integration with minimal side effects.     

Resistance to adhesion formation: A comparative study of treated and untreated mesh products placed in the abdominal cavity

Background: New materials have been devised to prevent postoperative adhesions when placing a prosthesis in contact with abdominal contents. Methods: Eighty rats underwent laparotomy and denudation of the serosa of the cecum and peritoneal covering of the abdominal wall. Five treated mesh products (Parietex Composite, Parietene Composite, Bard Composix E/X, Sepramesh, and Gore-Tex Dual Mesh) and one untreated mesh product (untreated Parietene) were randomly placed between the cecum and abdominal wall. A group without mesh was used as control. The animals were sacrificed at 21 days following surgery and analyzed for the presence of adhesions.Results: The incidence of adhesion formation, mean adhesion area, maximum adhesion length, and strength of adhesion separation were similar between Parietex Composite, Parietene Composite, and Bard Composix E/X, and they were significantly less than with Sepramesh, untreated Parietene, and the control group. Gore-Tex Dual Mesh resulted in less adhesions, adhesion area, mean strength of separation, and work of separation than the untreated Parietene group and the control group. Sepramesh resulted in less strength and work of separation compared to the control group. Conclusions: The incidence of adhesions and work and strength of adhesion separation are reduced when using a treated mesh, compared to the untreated mesh and the control group without mesh. Parietex Composite, Parietene Composite, Bard Composix E/X, and Gore-Tex Dual Mesh were superior to Sepramesh, untreated Parietene, and the control group in the prevention of adhesion formation.Disclosure statement: This study was sponsored by: Sofradim, Trévoux, France     

Tissue attachment strength of prosthetic meshes used in ventral and incisional hernia repair. A study in the New Zealand White rabbit adhesion model

Background: Many prosthetic materials are used in incisional hernia repair, including polypropylene (PP) and expanded polytetrafluoroethylene (ePTFE). However, PP forms severe adhesions and ePTFE has raised concerns about the adequacy of tissue attachment. Methods: The early tissue attachment strength of PP and two new forms of ePTFE (DLM and DLMC) was compared in a rabbit model (n = 12) in which disks of the three meshes (n = 8 of each material) were implanted against the abdominal wall for 3 days. Results: Tensiometer testing found that DLMC mesh had significantly greater attachment strength than PP (p = 0.02). Histologic studies indicated that this was due to cellular ingrowth. Tissue adhesions were observed with all eight PP disks, one DLMC disk, and none of the DLM disks. Conclusion: Modified forms of ePTFE mesh may provide abdominal wall repairs that are as strong or stronger than those obtained with PP, with early tissue attachment and without adhesions.     

Prevention of adhesion formation with use of sodium hyaluronate-based bioresorbable membrane in a rat model of ventral hernia repair with polypropylene mesh--a randomized, controlled study

BACKGROUND: There is a high incidence of adhesions after ventral hernia repair with polypropylene mesh. Hyaluronic acid (HA)-based membrane has been shown to reduce the incidence of adhesions in the absence of prosthetic mesh. The purpose of this study was to determine the effect of HA membrane on the quantity and grade of adhesions and its effect on strength of repair after abdominal wall repair with polypropylene mesh. METHODS: In 61 rats a full-thickness abdominal wall defect (excluding skin) was created, and a section of small bowel was abraded. The animals were randomized, receiving either HA membrane to cover the viscera or no membrane. The fascial defect was repaired with polypropylene mesh. Equal numbers of animals from each group were killed at 4 weeks and 8 weeks after surgery. Adhesion severity and percentage of mesh surface covered with adhesions were estimated. Tensile strength between mesh and muscle from each animal was measured. Sections of the mesh-muscle interface were examined histologically and measured for thickness and graded for inflammation and fibrosis. RESULTS: Fifty-five animals survived until the end point. Animals in the HA membrane group had a significant reduction in (1) grade of adhesions between small bowel and mesh at 4 weeks (P = .009) and 8 weeks (P = .000001), (2) grade of adhesions between colon and mesh at 8 weeks (P = .00003), and (3) percentage of mesh covered with adhesions at 4 weeks (P = .01) and 8 weeks (P = .0000002). There was no difference between the 2 groups in tensile strength of the repairs, tissue thickness, degree of inflammation, or degree of fibrosis. CONCLUSIONS: HA membrane reduces the quantity and grade of adhesions of both small and large bowel, to polypropylene mesh in a rat model of ventral hernia repair, without compromising strength of the repair.     

Hernia recurrence through a composite mesh secondary to transfascial suture holes

Laparoscopic ventral hernia repair is an accepted method for incisional hernia repair. Although techniques vary, transfascial suturing of the mesh to the abdominal wall has been proposed as a viable way to fixate the mesh and reduce recurrence rates. We report a 54-year-old woman who had previously undergone a laparoscopic ventral hernia repair following a laparoscopic tubal ligation using a Composix mesh. The patient presented with a symptomatic hernia recurrence. The computed tomography scan showed a periumbilical hernia containing fat. The patient underwent diagnostic laparoscopy and lysis of adhesions. During the lysis of adhesions, a recurrence through the previously placed composite mesh was encountered where holes had been made by the previously placed transfascial sutures. The hernia was reduced, mesh was removed, and an ePTFE mesh was used to repair the hernia. The mechanism of recurrence appeared to be improperly placed transfascial sutures; overly large bites of mesh caused excessive tension and ultimately a hole in the mesh. Hernia recurrence due to mesh or transfascial suture failure is rarely reported and most often caused by inadequate fixation. Our case highlights the need for meticulous placement of transfascial sutures and demonstrates a mechanism of recurrence due to inadequate placement.     

Peritoneal effects of prosthetic meshes used to repair abdominal wall defects: monitoring adhesions by sequential laparoscopy

BACKGROUND: The prosthetic materials currently used to repair abdominal wall defects sometimes have to be placed in contact with the visceral peritoneum. This interface is often a site of complications such as intestinal obstruction or fistulas due to adhesions. The aim of this study was to follow the process of adhesion formation in several prosthetic materials by sequential laparoscopy. MATERIAL AND METHODS: Defects (7 x 5 cm) were created in the abdominal wall of 30 New Zealand White rabbits and repaired using Surgipro polypropylene mesh (PP), Ultrapro monocryl-prolene mesh (UP), Dual Mesh expanded polytetrafluoroethylene (ePTFE), Composix (PP-ePTFE), Parietex Composite (polyester with collagen-polyethylene glycol-glycerol coating [PO-gl]), or PL-PU99 (PP-polyurethane) patches fixed to the edges of the defect by running polypropylene suture. Adhesions to the implants were laparoscopically determined at 3, 7, and 14 days after surgery. RESULTS: Percentage adhesion scores were significantly lower for ePTFE, PP-ePTFE, PO-gl, and PP-PU, compared to PP or UP. No differences were observed in adhesion scores recorded at 3, 7, and 14 days postimplant. Reticular prostheses were infiltrated by disorganized scar tissue with fibers concentric to the mesh filaments. In contrast, ePTFE implants were encapsulated by organized tissue, with fibers running parallel to the surface of biomaterial. All three composites achieved good recipient tissue integration and a homogeneous, organized, and well-vascularized neoperitoneum. CONCLUSION: At 14 days postimplant, laminar prostheses and composites showed similar results in terms of adhesion formation and integration within host tissue. Our findings suggest that both the composite prostheses and the laminar ePTFE performed very well in terms of reduced adhesion formation at the peritoneal interface.     

复合补片修补腹壁肿瘤切除后巨大腹壁缺损的临床疗效

目的探讨复合补片修补腹壁肿瘤切除后巨大腹壁缺损的临床疗效。 方法回顾性分析2015年2月至2017年8月,新疆医科大学第四附属医院收治的55例腹壁肿瘤切除术后巨大腹壁缺损患者临床资料,根据植入补片的不同分为试验组（35例）和对照组（20例）,2组患者均行腹壁肿瘤切除术,试验组植入Proceed补片,对照组植入Composix Kugel补片。比较2组手术相关临床参数、手术前后不同时间疼痛程度、切口愈合情况、并发症、肿瘤复发及转移情况。 结果2组铺置补片时间及术后自主活动时间比较,差异无统计学意义（P>0.05）。术后12 h至7 d,2组患者视觉模拟评分均呈逐渐降低趋势,且均明显低于术前（P<0.05）,但2组间均无明显差异（P>0.05）。拆线后伤口均达到一期愈合,2组总并发症发生率比较,差异无统计学意义（P>0.05）。随访1年,试验组肿瘤原位复发1例,对照组肿瘤远处转移1例,2组患者腹壁修复材料腹腔面光滑,且均未见腹壁修复材料与肠管黏连。 结论采用Proceed补片和Composix Kugel补片对腹壁肿瘤切除后巨大腹壁缺损进行修复和重建,效果均较好,安全性高。     

Ventral hernia repair by the laparoscopic approach

An analysis of these results indicates that laparoscopic hernia repair can be performed safely by experienced laparoscopic surgeons, and with lower perioperative complication rates than for open hernia repair. Although the follow-up period for the laparoscopic repair is only 2 or 3 years, the recurrence rate is likely lower than with open repair. Most patients with ventral hernias are candidates for this laparoscopic repair if safe access and trocar placement can be obtained. The choice of mesh often provokes a debate among surgeons, but little practical difference in the results seems to exist between the two types of mesh available. Although the ePTFE mesh has a good theoretic basis for promoting tissue ingrowth on the parietal side of the mesh and minimizing adhesions to the bowel side of the mesh, data indicate that no difference in outcome exists related to adhesions or fistula formation (Tables 1 and 2), so surgeon preference and cost of the prosthesis should be the deciding variables. Fistulas are of concern because of the experience with mesh in the trauma patient and in the treatment of severe abdominal wall infections, when abdominal wall reconstruction often is performed in contaminated wounds in the acute phases and leaves the mesh exposed without soft tissue coverage. These conditions do not apply for most cases of elective hernia repair. Laparoscopic ventral hernia repair offers advantages over the conventional open mesh repair and may decrease the hernia recurrence rate to 10% to 15%. When properly performed, the laparoscopic approach does not and should not compromise the principles for successful mesh repair of ventral hernias.     

Composite, non-resorbable parietal prosthesis with polyethylene terephtalate-polyurethane (HI-TEX PARP NT): prevention of intraperitoneal adhesions. Experimental study in rabbits

The authors report an experimental study in the rabbit with a new composite non absorbable mesh in Polyethylene Terephtalate-Polyurethane used for incisional hernia repair in intraperitoneal positioning. This new mesh has one permeable side in polyethylene terephtalate for rapid tissue fixation and another side in polyruethane, hydrophob in order to avoid cell penetration. Eighteen rabbits were operated. A wound was created in aponeurose, muscle and peritoneal abdominal wall. The mesh was placed in intraperitoneal positioning and was taken off at 4, 9 and 13 months for histologic examination and electronic microscopical examination. Tolerance, adhesion, tissular reaction and neoperitoneum formation have been studied. All the meshes were well integrated and without sepsis. In 18% of cases small and monocclusive intraperitoneal adhesions were found. This new composite mesh in intraperitoneal positioning gave good results at medium-term in the rabbit. It's an attractive alternative for incision hernias repair with intraperitoneal mesh.     

Perineal hernia as a rare complication after laparoscopic abdominoperineal resection: Report of a case

We report what seems to be the second documented case of perineal hernia after laparoscopic abdominoperineal resection (APR) and describe its successful repair with transperineal intraperitoneal mesh. An 89-year-old woman complained of a large, painful perineal swelling 4 months after APR for rectal cancer. Computed tomography (CT) showed small intestine protruding through the pelvic floor into the perineal area. However, opening of the hernia sac revealed no intra-abdominal adhesions. An oval, 8 × 12 cm Bard Composix Kugel Patch (Davol, Cranston, RI, USA) was inserted into the intraperitoneal space and secured over the defect in the pelvic floor; then firmly attached to the pelvic wall with 16 interrupted nonabsorbable sutures. There has been no sign of hernia recurrence in 10 months of follow-up. We speculate that because laparoscopic surgery is minimally invasive, fewer postoperative adhesions in the abdominal cavity can result in the small bowel sliding more readily into the perineal area. Based on our experience, perineal hernia after laparoscopic APR can be repaired easily and effectively with a Composix Kugel Patch.     

三种复合补片在污染环境下修补大鼠腹壁缺损的比较研究

目的观察聚丙交己内酯(polylactide-co-caprolactone,PLC)、透明质酸(hyaluronic acid,HA)、胶原蛋白与聚丙烯(polypropylene,PP)网片复合,在污染环境下修补大鼠腹壁缺损后粘连情况和修补效果,比较3种复合补片特点及一期修补可行性。方法成年雄性Wistar大鼠93只,体重150～250 g,随机分为3组(n=31):PP/PLC复合补片组(A组),PP/HA/PLC复合补片组(B组),PP/胶原蛋白/PLC复合补片组(C组)。各组取1只大鼠小肠制备污染源匀浆。其余大鼠制备直径约1 cm的腹壁疝模型后,根据分组将直径1.5 cm的复合补片缝合于腹壁缺损处。术后观察大鼠一般情况;于术后30、60、90 d处死大鼠,大体观察腹腔脏器粘连情况;切取补片及其周围组织进行组织学观察。结果术后10～70 d共6只大鼠死亡,其中A组2只,B组3只,C组1只;死亡原因均与补片修补无关。术后各时间点各组均见腹腔脏器与补片粘连,主要为肠管、网膜、肝。按照修正的Katada粘连评分方法,术后30、60 d各组间粘连评分比较,差异均无统计学意义(P>0.05);90 d时C组粘连评分显著低于A、B组(P<0.05)。组织学观察,术后30 d各组补片周围可见炎性细胞浸润,成纤维细胞出现且胶原分泌增加,可吸收材料残留;60 d时补片周围炎性细胞较前减少,成纤维细胞数量及胶原分泌较前增加,各组仅见PLC残留;90 d时成纤维细胞日趋成熟,可见胶原充填,腹腔面可见间皮层逐渐形成,各组残留PLC较前减少。结论 在污染环境下,PP/胶原蛋白/PLC复合补片在腹腔粘连及局部组织反应方面均优于PP/PLC及PP/HA/PLC复合补片,更适于一期修补大鼠腹壁缺损,但其远期效果及安全性仍待进一步确定。     

Comparison of adhesive properties of five different prosthetic materials used in hernioplasty.

This experimental study was designed to assess and to compare intra-abdominal adhesions following the use of five commercially available prosthetic mesh grafts in the repair if abdominal wall defects. Sixty Wistar albino rats were randomly divided into six groups (n = 10). A 2 x 1 cm defect at abdominal wall was created and defects were closed either primarily or with one of the following prosthetic mesh grafts: monofilament polypropylene, polytetrafluoroethylene, sodium hyaluronate/carboxymethylcellulose-coated polypropylene, polypropylene/polyglactin 910 composite, or resorbable hydrophilic collagen-coated multifiber polyester. The severity of adhesions was graded, tensile strengths of adhesions were measured, and histopathological grades of inflammation and fibrosis were evaluated. Polypropylene mesh resulted in more adhesion formation in comparison to primary repair and other grafts used in this study, except polypropylene/polyglactin 910 composite mesh. In addition, the highest tensile strength of omental adhesions was detected in the polypropylene group (chi2 = 26.249; p = .0001). Polyester composite mesh caused the least adhesion formation among the groups. Sodium hyaluronate/carboxymethylcellulose-coated polypropylene and polyester composite meshes revealed the highest fibrosis scores (chi2 = 50.776; p = .0001). The highest inflammatory activity was detected in the polytetrafluoroethylene mesh group (chi2 = 16.564; p = .005). Thus, sodium hyaluronate/carboxymethylcellulose-coated polypropylene and polytetrafluoroethylene meshes following polyester composite mesh were the minimal adhesion-forming grafts in this study. Disadvantages of the polytetrafluoroethylene mesh were lower fibrotic activity and higher inflammatory reaction to the graft.     

Adhesion formation and reherniation differ between meshes used for abdominal wall reconstruction

Incisional hernia is a common surgical problem, frequently requiring prosthetic mesh repair. The demands of the ideal mesh seem conflicting; ingrowth at the mesh–fascia interface, without development of adhesions at the visceral mesh surface. Various antiadhesives combined with macroporous mesh and composite meshes were studied for prevention of adhesions to mesh and ingrowth into the fascia. In 60 rats an abdominal wall defect was created and repaired with underlay mesh. Rats were divided into six groups and treated with polypropylene mesh (PPM, control), PPM with auto-cross-linked polymers (ACP) gel, PPM with fibrinogen glue (FG), polypropylene/expanded polytetrafluoroethylene (ePTFE) mesh, polypropylene/sodium hyaluronate/carboxymethylcellulose (HA/CMC) mesh, and polypropylene-collagen/polyethylene-glycol/glycerol (CPGG) mesh. Mesh infection was assessed in the postoperative period, adhesions and reherniations were scored at sacrifice 2 months after operation, and tensile strength of the mesh–tissue interface was measured. Six rats developed mesh infection, half of them were treated with PPM/ePTFE. The PPM/HA/CMC group showed a significant reduction in the amount and severity of adhesions. In animals treated with PPM/ACP and PPM/FG, severity of adhesions was reduced as well. Reherniation rate in the PPM/ACP group was 50% and significantly higher than that in other groups. Rats in the PPM/HA/CMC had the highest tensile strength. PPM/HA/CMC approaches the demands of the ideal mesh best, having superior antiadhesive properties, no reherniation and no infection in this rat model of incisional hernia.     

Does hyaluronic acid-carboxymethylcellulose (HA-CMC) membrane interfere with the healing of intestinal suture lines and abdominal incisions?

Although hyaluronic acid-carboxymethylcellulose (HA-CMC) membrane has the advantage of preventing intraabdominal adhesions, it has theoretical risk of negative effects on the healing of intestinal suture lines by forming a barrier between the suture lines and neighboring serosal surfaces. This study evaluated the effect of HA-CMC on bowel anastomoses, scar healing, and intraabdominal adhesion formation. Two groups of 10 male Sprague-Dawley rats were examined. In the first group, laparotomy was performed with a median incision. Colotomy on the cecum and a single-layer repair of the bowel wall was performed. HA-CMC membrane was placed on the cecal suture line and under the laparotomy incision before abdominal closure. The second group had the same procedure but no HA-CMC membrane was placed. The animals were killed on postoperative day 14. Intraabdominal adhesions, laparotomy suture line endurance, bursting pressure of the repaired cecal wall, and tissue hydroxyproline levels were determined. The repaired cecal wall was also examined histopathologically. The statistical analyses revealed that HA-CMC prevented intraabdominal adhesions significantly. No negative effects of this material on the healing of the bowel and laparotomy suture lines were observed. HA-CMC appears to be a safe material to prevent intraabdominal adhesions, without negative effects on the healing of abdominal incisions and bowel suture lines.     

Prevention of adhesion to prosthetic mesh: comparison of different barriers using an incisional hernia model

OBJECTIVE: To assess whether use of antiadhesive liquids or coatings could prevent adhesion formation to prosthetic mesh. SUMMARY BACKGROUND DATA: Incisional hernia repair frequently involves the use of prosthetic mesh. However, concern exists about development of adhesions between viscera and the mesh, predisposing to intestinal obstruction or enterocutaneous fistulas. METHODS: In 91 rats, a defect in the muscular abdominal wall was created, and mesh was fixed intraperitoneally to cover the defect. Rats were divided in five groups: polypropylene mesh only (control group), addition of Sepracoat or Icodextrin solution to polypropylene mesh, Sepramesh (polypropylene mesh with Seprafilm coating), and Parietex composite mesh (polyester mesh with collagen coating). Seven and 30 days postoperatively, adhesions were assessed and wound healing was studied by microscopy. RESULTS: Intraperitoneal placement of polypropylene mesh was followed by bowel adhesions to the mesh in 50% of the cases. A mean of 74% of the mesh surface was covered by adhesions after 7 days, and 48% after 30 days. Administration of Sepracoat or Icodextrin solution had no influence on adhesion formation. Coated meshes (Sepramesh and Parietex composite mesh) had no bowel adhesions. Sepramesh was associated with a significant reduction of the mesh surface covered by adhesions after 7 and 30 days. Infection was more prevalent with Parietex composite mesh, with concurrent increased mesh surface covered by adhesions after 30 days (78%). CONCLUSIONS: Sepramesh significantly reduced mesh surface covered by adhesions and prevented bowel adhesion to the mesh. Parietex composite mesh prevented bowel adhesions as well but increased infection rates in the current model.     

Laparoscopic incisional hernia repair in a porcine model: What do transfixion sutures add?

BACKGROUND: The aim of this study was to evaluate the need for transfixion sutures during laparoscopic ventral hernia repair with mesh. METHODS: Incisional hernias were created in 14 Yucatan mini-pigs. Animals were randomized to undergo laparoscopic hernia repair either with spiral tacks alone (Tacks) or with tacks and 4 Prolene transfixion sutures (Sutured) using Composix E/X mesh (Davol Inc.). At 4 weeks, exploratory laparoscopy was performed to assess the repair and score adhesions. The abdominal wall was harvested for tensile strength analysis and histologic evaluation. Continuous variables were compared using a two-tailed nonpaired t-test. Results are presented as mean +/- standard deviation. RESULTS: The mean hernia size was 8.5 +/- 0.5 cm by 5.5 +/- 0.7 cm, with no difference between groups. The operative time was significantly longer ( p = 0.006) for the Sutured group (62.1 +/- 16.8 min) than for the Tacks group (32.3 +/- 7.0 min). The number of tacks per repair was equivalent between groups. At necropsy, the mesh in all cases was well incorporated, reperitonealized, and without evidence of migration. No hernias recurred. However, the Sutured group had a significantly ( p < or = 0.05) higher adhesion score (5.4 +/- 3.3) than the Tacks group (2.0 +/- 2.7). The tensile strength of the repair zone was no different between groups (Sutured 4.8 +/- 1.5 N/cm, Tacks 3.8 +/- 1.4 N/cm). On histologic examination, the ratio of inflammatory cells to fibroblasts was similar between groups (Sutured 0.2 +/- 0.6, Tacks 0.2 +/- 0.3). Only 82% of tacks in each group penetrated the fascia, and the depth of tack penetration was similar between groups (Sutured 3.7 +/- 0.3 mm, Tacks 3.9 +/- 0.4 mm). CONCLUSIONS: In a porcine model, the use of transfixion sutures was associated with longer operative times and more adhesions, without improvement in tensile strength or mesh incorporation. A human clinical trial is needed to determine the optimal method of securing abdominal wall mesh.     

Evaluation of seprafilm and amniotic membrane as adhesion prophylaxis in mesh repair of abdominal wall hernia in rats

INTRODUCTION: Adhesion formation following abdominal wall hernia repair with prosthetic mesh may lead to intestinal obstruction and enterocutaneous fistula. Physical barriers, namely, human amniotic membrane (HAM) or Seprafilm (Genzyme, Cambridge, Mass., USA), a bio-absorbable, translucent membrane composed of carboxymethylcellulose and hyaluronic acid, have been reported to prevent postsurgical intra-abdominal adhesions. OBJECTIVE: Evaluating the effect of HAM and Seprafilm in preventing adhesion formation in the rat model of ventral hernia repair with polypropylene mesh (PPM). MATERIAL AND METHODS: Sixty female Sprague-Dawley rats were divided into three groups. A full-thickness abdominal wall defect was created in each animal. Control animals had the PPM sutured into the defect, whereas in the other two groups, either HAM or Seprafilm were laid over the abdominal viscera before the repair with PPM. Half of the animals in each group were sacrificed on the 21st postoperative day. The remaining rats of the same group were re-operated on the 42nd day for investigation and measurement of the adhesion area in relation to the graft area. RESULTS: Direct mesh repair showed 52.8 and 56% area adhesion formation 3 and 6 weeks postoperatively, respectively. The HAM barrier covered with mesh repair demonstrated 0 and 0.96% area adhesion formation, and the Seprafilm-covered mesh repair showed 0 and 0% area adhesion formation 3 and 6 weeks postoperatively, respectively. Uncovered mesh showed a significantly larger adhesion area than both covered mesh (p = 0.001 and 0.001). Both HAM and Seprafilm were equally effective in preventing postoperative adhesions. CONCLUSIONS: HAM and Seprafilm proved to be an effective antiadhesive barrier in PPM repair of abdominal wall hernia.     

纳米仿生防粘连复合补片修复大鼠腹壁缺损中胶原合成功能的研究

目的评估纳米仿生、防粘连复合型疝补片修复腹壁疝的胶原蛋白合成功能的优劣,为临床提供实验依据。 方法选择成年SD雄性大鼠90只,随机分为3组：纳米仿生、防粘连复合型疝补片（nano-bionic and anti-adhesive compound hernia patch,NT）组,聚丙烯补片（polypropylene patch,PP）组及聚酯补片（polyester patch,PE）组,构建腹壁疝模型。根据分组将大小约3 cm× 2 cm的3组补片缝合于腹壁缺损处。术后观察大鼠一般情况,分别于术后4、6、8周处死大鼠各10只,大体观察腹腹壁手术区域胶原组织形成情况;剪取补片及其周围组织进行组织学观察,分析胶原蛋白表达情况,并进行Western bolt分析各组腹壁修复区域Ⅰ型胶原蛋白及Ⅲ型胶原蛋白表达量。 结果各组大鼠术后一般情况均良好,未出现死亡等不良事件;腹壁手术区域,NT组触感柔软,异物感较少,未见明显腹腔脏器突出,纤维组织生长情况良好;PP组触感较僵硬,皮下可见大量新生血管长入,异物感较重,纤维组织生长情况一般;PE组大鼠腹壁修复区触感僵硬,皮下可见较多新生血管长入,纤维组织生长较好。组织学观察：术后各个时间点,NT组修补效果优于PP、PE组,NT组Ⅰ型胶原表达更多,Ⅲ胶原表达更少,比例更加合理,纤维结构更加成熟稳定。组织蛋白含量：随着时间推移,术后各组Ⅰ型胶原蛋白随着时间进展逐步增加,而且NT组在各个时间点明显高于PP组及PE组,差异有统计学意义;术后6周及术后8周NT组的Ⅰ/Ⅲ型胶原蛋白比例基本保持在4∶1左右,较术后4周明显增加,而且在各个时间点上NT组均高于PP、PE组,差异有统计学意义。 结论在常规腹壁缺损无张力修补术过程中,NT补片在组织重构过程中比PP及PE补片更早形成成熟稳定的纤维结构,提供更加稳固的修复效果,适用于目前常规的腹壁疝修补,尤其是巨大腹壁缺损引起的腹壁疝。     

Prevention of intraabdominal adhesions produced by polypropylene mesh

Polypropylene mesh (PPM) is widely used in ventral hernia repair, however is also associated with visceral adhesions when the mesh is exposed to intraabdominal organs. In this study, a composite mesh [ePTFE (expanded polytetrafluoroehylene) + PPM] and sodium hyaluronate/carboxymethyl cellulose (NaHA/CMC) membrane laid under PPM are evaluated in terms of adhesion formation in a rat model of ventral hernia repair. In this experimental study, a 2 x 1 cm of peritoneum and underlying muscle defect was created at the right side of the anterior abdominal wall of 37 male Wistar albino rats. These defects were repaired with 2.5 x 2 cm PPM in group 1 (n = 13), with composite mesh in group 2 (n = 12) and with PPM+NaHA/CMC in group 3 (n = 12). Rats were sacrificed after 14 days and the prosthetic materials were examined for the calculation of surface area percentage covered by adhesions, for organ involvement in the adhesions and for histological evaluation. There was a reduction in the adhesion-covered area in group 2 and group 3. Organ involvement was predominantly seen in group 1. Neoperitoneum was perfect in group 2. Fibrosis and inflammation were higher in group 1. All groups showed adhesiogenic potential to some extent. This potential was maximum with PPM. Both ePTFE and NaHA/CMC displayed similar effects in preventing adhesion formation.