Use of porcine dermal collagen graft (Permacol) for hernia repair in contaminated fields

Background Complicated hernias often involve contaminating surgical procedures in which the use of polypropylene meshes can be hazardous. Prostheses made of porcine dermal collagen (PDC) have recently been proposed as a means to offset the disadvantages of polypropylene meshes and have since been used in humans for hernia repairs. The aim of our study was to evaluate the safety and efficacy of incisional hernia repair using PDC as a mesh in complicated cases involving contamination. Methods A prospective study of hernia repair of complicated incisional hernias with contamination using PDC grafts was carried out at the Department of General, Emergency and Transplant Surgery of St Orsola-Malpighi University Hospital. Results From January 2004 up to the writing of this article, seven patients were treated for complicated incisional hernias with a PDC prosthesis. In six out of seven patients a bowel resection was carried out. There were not surgical complications. Morbidity was 14.2%. No recurrences and wound infections were observed. Conclusions Incisional hernioplasty using PDC grafts is a potentially safe and efficient approach in complicated cases with contamination.     

Laparoscopic repair of a Littre’s hernia with porcine dermal collagen implant (Permacol)

Background Littre’s hernia was originally defined as “the presence of a Meckel’s diverticulum in any hernia sac” by Rieke in 1841. It is a rare finding at any age, and its true incidence is unknown. The conventional treatment for Littre’s hernia is wedge resection of the diverticulum and repair of the hernia from within the sac. However, the advent of laparoscopic surgery has altered the management of all abdominal hernias, including Littre’s hernia. Case report We present a case of a 55-year-old woman who presented as an emergency with right iliac fossa pain and tenderness. A CT scan demonstrated a 46 × 25 × 25 mm lesion related to the distal ileum extending towards the inguinal canal. At laparoscopy she was found to have a Meckel’s diverticulum herniating through the deep inguinal ring into the right inguinal canal. We report the laparoscopic excision of the Meckel’s diverticulum using an endoscopic stapling device and repair of this hernia with Permacol, an acellular porcine collagen mesh. The patient made a quick recovery and was discharged 5 days post-operatively. A complication of an umbilical port site infection was treated 2 weeks post-operatively with oral antibiotics. To date there has been no recurrence of the hernia and no right inguinal pain. Laparoscopic repair of Littre’s hernia using Permacol has not been reported previously. Conclusions Laparoscopy is a safe, inexpensive and efficient method for the diagnosis and treatment of Littre’s hernia. Permacol is a strong yet supple material for hernia repair.     

Biocompatibility of bacterial contaminated prosthetic meshes and porcine dermal collagen used to repair abdominal wall defects

Background and aims A contaminated or infected surgical site is considered a contraindication for the use of the nonabsorbable alloplastic materials employed to repair abdominal wall defects. Therefore, the biocompatibility of new prosthetic materials was investigated. Materials and methods Meshes measuring 1.5×1.5 cm made of conventional and titanium-coated polypropylene, polyglycol, or porcine dermal collagen were implanted under the abdominal wall of 96 rats (eight groups of 12 animals each) employing the inlay technique. Implantation of all four materials was performed both under semisterile conditions and bacterial contamination of the mesh. The meshes were explanted after 28 days. Results All the materials implanted under semisterile conditions were incorporated into the abdominal wall with only few intraabdominal adhesions (mean adhesion scores: 1.0, 1.2, 1.0, 0.8 points, respectively, not significant). With the porcine dermal collagen, proliferation rate and the proportion of inflammatory cells were statistically lower (p<0.01). In the bacterial contamination group, all meshes were associated with a suppurating infection and strong adhesions between the bowel and mesh, which were most prominent in the case of dermal collagen (mean adhesion scores: 1.6, 1.7, 1.7, and 1.9 points, respectively, not significant). In this group, two animals died of peritonitis. In comparison with the other materials, the proliferation rate was significantly elevated (p=0.03). No significant differences were seen between the other materials employed. Conclusion Irrespective of the material employed, implantation of alloplastic meshes in an abdominal wall contaminated with bacteria, is associated with suppurating infections, in particular in the case of the membrane-like porcine dermal collagen. Nonabsorbable alloplastic meshes and dermal skin grafts should therefore not be used to repair infected abdominal wall defects.     

Effectiveness of porcine dermal collagen in giant hernia closure in patients with deleterious fascia constitution after orthotopic liver transplantation

Incisional hernias (IHs) occur universally after orthotopic liver transplantation (OLT). This study aimed to investigate the effectiveness of porcine dermal collagen (PDC) as a closing aid in giant hernias after OLT in a prospective trial. If direct closure (DC) was not feasible due to the hernia size and abdominal wall constitution, a PDC mesh was implanted. All patients from the PDC and DC groups were followed prospectively for 24 months. IH recurrence rates served as the primary endpoint, and the development of infections and wound healing disorders served as the secondary endpoints. Recurrence rate was 21% (4/19) in DC patients and 12% (2/16) in PDC patients (P = 0.045). Implant site infections occurred in five of PDC and one of DC patients (P < 0.05). All of them were managed with antibiotics; two of the PDC patients required surgical drainage. Histological analysis of PDC mesh biopsies indicated good angiogenesis and integration of the PDC into the abdominal wall. PDC was effective in our study for incisional hernia repair, and our results compared favourably with those of patients in whom direct hernia closure was feasible.     

Acellular dermal matrix in the management of high-risk abdominal wall defects

BACKGROUND: Ventral hernia repair in the face of a contaminated field or with questionable skin coverage requires either complex abdominal wall flaps or a staged repair. The development of biologic prostheses has altered the approach to these difficult clinical problems. METHODS: The study population consisted of human acellular dermal matrix (HADM) implantation into wounds considered high risk, defined as either infected or with poor skin coverage. Patient demographics, preoperative risk factors and infection data, postoperative wound complications, and long-term results were collected. RESULTS: Twenty-nine patients were identified in whom ADM was implanted into high-risk hernia defects. Forty-five percent developed a postoperative wound occurrence, with 31% requiring the wound to be either treated open or with a percutaneous drain. Ninety-six percent went on to heal without event. The follow-up evaluation averaged 182 days. Eighty-nine percent were repaired successfully with one surgery. Three recurrences have been identified. CONCLUSIONS: The use of ADM allowed for successful primary closure in 90% of patients with intermediate- to long-term follow-up evaluation. A postoperative wound occurrence rate of 45% shows the use of this material in resisting infection. ADM can be used in ventral hernia repair in high-risk wounds with a high degree of success.     

Use of porcine dermal collagen as a prosthetic mesh in a contaminated field for ventral hernia repair: a case report

Chronic infection of a prosthetic mesh implant is a severe complication of ventral hernia repair, and mesh explantation is usually required in these cases. Biologic mesh implants have a possible role in ventral hernia repair in this setting. Here we present a case of chronic mesh infection following ventral hernia repair and the use of a biologic mesh to repair the existing defect following explantation of the infected mesh. Analysis of the explant material demonstrated possible oxidative degradation of the original polypropylene. A review of the literature follows. An erratum to this article can be found at     

Adverse effects associated with the use of porcine cross-linked collagen implants in an experimental model of incisional hernia repair

BACKGROUND: Porcine cross-linked collagen (PermaCol, PCL; TSL, Aldershot, United Kingdom) has been proposed as permanent biomaterial in incisional hernia repair. We evaluated the biocompatibility of PCL in an established animal model. MATERIAL AND METHODS: In 10 Sprague Dawley rats, two hernias per animal were created in the abdominal wall left and right of the linea alba (1.5 cm in diameter), and the peritoneum was spared. The lesions were left untreated for 10 days, until incisional hernias developed. These defects were covered with non-perforated (out-of-the-box, n = 12) or perforated (modified; n = 8) PCL (2 x 2 cm). In a first step, 12 non-perforated implants were tested in a short-term observation period of 17 days. Eight of these non-perforated implants were fibrin sealed (0.3 mL, Tissucol; Baxter, Vienna, Austria), whereas four non-perforated implants were sutured with non-resorbable material. In a second step, perforations were added as modification to PCL to facilitate drainage of fluids, cell ingrowth, and transgression of fibrin sealant. All perforated implants were fibrin sealed and included in a long-term observation period of 3 months. The observation periods allowed the evaluation of the complete degradation of the fibrin sealant fixation after 2 weeks and of the implant integration in a chronic timeframe. Implant sites were analyzed macroscopically and histologically. RESULTS: All PCL samples elicited strong local inflammation with signs of foreign body reaction. Integration of perforated PCL appeared limited after 3 months. Three animals had to be euthanized prior to intended time points because of transcutaneous migration of implants. CONCLUSIONS: In an experimental model of incisional hernia repair, PCL does not integrate well in the abdominal wall and shows poor biocompatibility.     

Fractal analysis of rat dermal tissue in the different injury states

Scar formation and chronic ulcers can develop following a skin injury. They are the result of the over‐ or underproduction of collagen. It is very important to evaluate the quality and quantity of the collagen that is produced during wound healing, especially with respect to its structure, as these factors are very important to a complicated outcome. However, there is no standard way to quantitatively analyse dermal collagen. As prior work characterised some potentially fractal properties of collagen, it was hypothesised that collagen structure could be evaluated with fractal dimension analysis. Small‐angle X‐ray scattering technology (SAXS) was used to evaluate the dermis of rats exposed to graft harvest, burn, and diabetic pathologic states. It was found that almost all collagen structures could be quantitatively measured with fractal dimension analysis. Further, there were significant differences in the three‐dimensional (3‐D) structure of normal collagen versus that measured in pathologic tissues. There was a significant difference in the 3‐D structure of collagen at different stages of healing. The findings of this work suggest that fractal analysis is a good tool for wound healing analysis, and that quantitative collagen analysis is very useful for assessing the structure of dermal collagen.     

Randomized trial of porcine dermal sling (Pelvicol<Superscript>™</Superscript> implant) vs. Tension-free Vaginal Tape (TVT) in the Surgical treatment of stress incontinence: a questionnaire-based study

 The objective of this study was to compare porcine dermal sling (Pelvicol^™ implant, Bard) with tension-free vaginal tape (TVT) in the surgical treatment of stress incontinence. One hundred and forty-two women with genuine stress incontinence (GSI) were randomly assigned to either Pelvicol^™ implant pubovaginal sling (n=74) or TVT (n=68). They were followed up at a minimum of 6 months (range 6–24 months), with a median follow-up of 12 months. The majority (n=109) of procedures were carried out in a day surgery unit. The median operation time was 35 minutes (range 15–60) in the TVT group and 30 minutes (range 20–80) in the Pelvicol^™ implant group; 81% of the TVT group and 77% of the Pelvicol^™ implant group were able to void urine within 24 hours, and had insignificant residual bladder volumes. The prevalence of postoperative symptomatic voiding dysfunction was 3.4% after TVT and 1.4% after Pelvicol^™ implant. Nine percent of the TVT group developed de novo urge incontinence and 6% of the Pelvicol^™ implant group had de novo urge incontinence 6 months after the procedure. Postoperative evaluation was done at the outpatient department, and a postal questionnaire was also completed to determine subjective continence status. The patient-determined cure rate was 85% in the TVT group and 89% in the Pelvicol^™ implant group. The Pelvicol^™ implant sling had a comparable patient- determined success rate with TVT and should be considered in the surgical treatment of women with genuine stress incontinence. Received: 15 January 2002 / Accepted: 1 July 2002     

Histological and biochemical analysis of the fibrous tissue induced by implantation of synthetic ligament (Dacron): An experimental study in a rat model

We conducted a comparative study to evaluate the quality and true nature of the fibrous tissue formed around synthetic grafts when used in ligament replacement. In one group of Lewis rats, a patellar ligament was replaced with a Dacron prosthesis; the comparison group received a tail tendon isograft. Two-, 4-, 8-, 12-, and 24-week comparisons showed histological and biochemical changes in the Dacron group alone that were consistent with foreign-body reaction. Specifically, the Dacron group showed infiltration by large numbers of macrophages and foreign-body, multinucleated giant cells. In addition, the capsule of fibrous tissue that developed around the Dacron ligaments was characterized by lower collagen solubility, a higher content of noncollagenous protein, and a higher proportion of type III collagen than that comprising the isografted tendons. The results of this study call into question the suitability of synthetics for ligament replacement.     

微囊化雪旺细胞/神经组织移植促进周围神经再生的实验研究

目的:探讨免疫隔离技术应用在神经细胞/组织移植促进周围神经再生的可行性.方法:采用静电液滴法制备海藻酸钠/聚赖氨酸/海藻酸钠(alginate-polysien-alginate,APA)微胶囊,包埋分离自SD大鼠周围神经的雪旺细胞(SChwann cells,SCs)/神经组织;采用台盼蓝拒染法和ELISA法检测其培养后活性和分泌神经生长因子情况.制备坐骨神经横断损伤的SD大鼠模型,将微囊化SCs/神经组织移植到实验组坐骨神经吻合口处.结果:微囊化SCs/神经组织培养一定时间后,仍保持活力和分泌神经生长因子的功能;4周后实验组吻合口远端可见到再生的阳性纤维,明显大于对照组,瘢痕明显少于对照组;实验组再生的神经纤维和新生的微小血管远较对照组密集.结论:微囊化SCs/神经组织移植后在局部持续分泌神经生长因子,有促进周围神经修复的作用.