Ventral abdominal wall defect correction in rats with contaminated meshes.

PURPOSE:: To investigate whether there is a difference between Marlex(r) and Dynamesh PP-light Marlex(r) meshes, in the abdominal wall defect correction, on rats in contaminated surgical site. METHODS:: Twenty-eight Wistar rats were divided into two groups of 14, and four subgroups of seven animals. All subgroups underwent similar surgical procedure. One group received the mesh Marlex(r) and the other Dynamesh PP-light(r) for correction of the defect. Before implanting, the meshes went through a contamination process, on which was used standard solution containing 10 UFC of Escherichia coli. Fragments of the animal's abdominal wall received macroscopic, microscopic and microbiological analysis. RESULTS:: There was no statistical significance in the analysis of macroscopic variables. Accentuated inflammatory process was shown in all subgroups. The foreign body type reaction was mild in all subgroups, except Dynamesh(r)-14, which was moderate with no statistical significance. The microbiological analysis of the meshes was also similar between the subgroups. CONCLUSION:: There was no difference between the meshes of Marlex(r) and Dynamesh PP-light(r) in the ventral abdominal wall defect correction on rats in contaminated surgical site.

Ventral abdominal wall defect correction in rats with contaminated meshes

PURPOSE:To investigate whether there is a difference between Marlex(r) and Dynamesh PP-light Marlex(r) meshes, in the abdominal wall defect correction, on rats in contaminated surgical site.METHODS:Twenty-eight Wistar rats were divided into two groups of 14, and four subgroups of seven animals. All subgroups underwent similar surgical procedure. One group received the mesh Marlex(r) and the other Dynamesh PP-light(r) for correction of the defect. Before implanting, the meshes went through a contamination process, on which was used standard solution containing 10 UFC of Escherichia coli. Fragments of the animal's abdominal wall received macroscopic, microscopic and microbiological analysis.RESULTS:There was no statistical significance in the analysis of macroscopic variables. Accentuated inflammatory process was shown in all subgroups. The foreign body type reaction was mild in all subgroups, except Dynamesh(r)-14, which was moderate with no statistical significance. The microbiological analysis of the meshes was also similar between the subgroups.CONCLUSION:There was no difference between the meshes of Marlex(r) and Dynamesh PP-light(r) in the ventral abdominal wall defect correction on rats in contaminated surgical site.(AU)

Ventral abdominal wall defect correction in rats with contaminated meshes

ABSTRACT PURPOSE: To investigate whether there is a difference between Marlex(r) and Dynamesh PP-light Marlex(r) meshes, in the abdominal wall defect correction, on rats in contaminated surgical site. METHODS: Twenty-eight Wistar rats were divided into two groups of 14, and four subgroups of seven animals. All subgroups underwent similar surgical procedure. One group received the mesh Marlex(r) and the other Dynamesh PP-light(r) for correction of the defect. Before implanting, the meshes went through a contamination process, on which was used standard solution containing 10 UFC of Escherichia coli. Fragments of the animal's abdominal wall received macroscopic, microscopic and microbiological analysis. RESULTS: There was no statistical significance in the analysis of macroscopic variables. Accentuated inflammatory process was shown in all subgroups. The foreign body type reaction was mild in all subgroups, except Dynamesh(r)-14, which was moderate with no statistical significance. The microbiological analysis of the meshes was also similar between the subgroups. CONCLUSION: There was no difference between the meshes of Marlex(r) and Dynamesh PP-light(r) in the ventral abdominal wall defect correction on rats in contaminated surgical site.

A retrospective analysis of surgical treatment of mesh infection after repair of ventral hernia or defect.

This study aimed to summarize our experience in surgical treatment of mesh infection after repair of ventral hernia or defect. A retrospective analysis was conducted on clinical data of 22 patients who accepted surgical treatment of mesh infection after ventral hernia or defect repair. Included were 16 cases of infection after incisional hernia repair, 5 cases of infection after abdominal wall defect repair following abdominal wall tumor resection, and 1 case of infection with fistula caused by a parastomal hernia of an ileal neobladder repair with a prosthetic patch. All patients had received local dressing treatment for 2 to 24 months but were not healed. The affected mesh was removed successfully in all patients. Six patients had abdominal wall repair using the component separation technique; 4 patients were treated by strengthened repair with polypropylene mesh; 10 patients were repaired with human acellular dermal matrix; 1 patient received local dressing changes and vacuum sealing drain treatment without repair; and 1 patient received wound closure without strengthened repair. The postoperative hospital stay was 9-29 days (mean 16 days). After treatment, 19 patients recovered with primary wound healing and 3 patients recovered with secondary healing. All patients were followed up for 6-38 months (mean 26 months), and no ventral hernia or defect recurred except 1 case of lower abdominal bulge. Mesh infections after ventral hernia or defect repair are difficult to treat using prosthetic materials. For satisfactory results, surgery should be performed according to the specific condition of the individual.

Infections associated with prosthetic repairs of abdominal wall hernias: pathology, management and results.

PURPOSE: To analyse clinical and demographic factors of patients who suffered infection of the surgical site requiring mesh removal as a complication of prosthetic repairs, details of the hernioplasties in which meshes were implanted and their management and outcomes. METHODS: Factors related to infection (demographic variables and characteristics of the repairs and mesh utilised) and the management before proceeding to mesh removal were obtained from patient charts. Collected specimens (meshes and tissues) from 32 consecutive patients were cultured and observed microscopically. The outcomes after mesh removal were prospectively evaluated. RESULTS: Twenty-two patients underwent incisional hernioplasties and ten inguinal hernioplasties; most of the procedures took a long time, and 28 patients presented early wound complications (seroma or haematoma). During the "implantation­removal" interval, some conservative treatments, such as drainages or sinus resection, were attempted under local anaesthesia. Twenty-two meshes were totally removed (nine after partial extraction); in the remaining ten cases partially removal was successful. Most of the meshes (24) were made of multi-filament polypropylene; microscopic observation of neighbouring tissues showed leucocyte infiltration, giant cell reaction, disorganisation of the collagen fibres and abscedation. Treatment of 32 patients required 51 operations. Following mesh removal, there were six recurrences and two fistulas of the bowel. The average follow-up was 40 months (30­97). CONCLUSIONS: Most of the infections requiring mesh removal were related to prolonged repair operations that presented untreated early postoperative wound complications. Partial extraction of meshes frequently leads to failures and complications. Surgical exploration should be performed under general anaesthesia to accomplish complete mesh extraction.

Infection on polypropylene mesh implantation site in the abdominal wall of rats with induced bacterial peritonitis.

PURPOSE: Evaluate incidence of bacterial growth on implanted meshes in the abdominal wall of rats after to induce bacterial peritonitis. METHODS: 36 rats were used. They were allocated in two groups: group B, experiment group (n =18) and group S, control group (n =18). They were submitted to the implant of polypropylene meshes on the abdominal wall, at the preperitoneal space. Then, in the animals of the experiment group, the induction of peritonitis was made through the inoculation in the peritoneal cavity of standardized solution of Escherichia coli. In the animals of the control group it was made through the inoculation of physiologic solution. The animals of both groups were reallocated in three subgroups of six animals and observed until the reoperations time, for evaluation of the implantation sites, collection of the meshes for cultures, evaluation of the abdominal cavity and peritoneal lavage for cultures. The reoperations occurred in 24, 48 and 72 hours. RESULTS: All the animals of the experiment group presented clinical symptoms of peritonitis. The cultures of the meshes taken off from the implantation sites were positive in 83% of the animals when the moment of the evaluations was of 24 hours, decreasing to 33% in 48 hours and 17% in 72 hours. Globally, it was of 44%. In the animals of the control group there was no case of positive culture neither in the meshes, nor in the peritoneal lavages. CONCLUSIONS: The experimental model used was effective, producing 100% of peritonitis. The incidence of bacterial growth on the implanted polypropylene meshes was 83% in 24 hours, decreasing with the time.

Infection on the meshes implantation area in the abdominal wall of rats with induced bacterial peritonitis

OBJETIVO: Avaliar a incidência do crescimento bacteriano em telas de polipropileno implantadas na parede abdominal de ratos, após a indução de peritonite bacteriana.MÉTODOS: Utilizaram-se 36 animais alocados em dois grupos: grupo B, experimento (n=18) e grupo S, controle (n=18). Os ratos foram submetidos ao implante de telas de polipropileno na parede abdominal, no espaço pré-peritoneal. Em seguida, nos animais do grupo experimento, procedeu-se à indução de peritonite pela inoculação na cavidade peritoneal de solução padronizada de Escherichia coli. Nos animais do grupo controle procedeu-se à inoculação de solução fisiológica. Os animais de ambos os grupos foram realocados em três subgrupos de seis animais e acompanhados até as reoperações para avaliação dos sítios de implantação, coleta das telas para culturas, avaliação da cavidade e lavados peritoneais para culturas. As reoperações ocorreram com 24, 48 e 72 horas.RESULTADOS: Todos os animais do grupo experimento apresentaram quadro de peritonite. As culturas das telas retiradas dos sítios de implantação mostraram-se positivas em 83% dos animais quando o momento das avaliações foi de 24 horas, diminuindo para 33% em 48 horas e 17% em 72 horas, globalmente foi de 44%. Nos animais do grupo controle não houve nenhum caso de cultura positiva, tanto nas telas quanto nos lavados peritoneais. CONCLUSÕES: O modelo experimental utilizado foi efetivo produzindo 100% de peritonites. A incidência de crescimento bacteriano nas telas de polipropileno implantadas foi de 83% com 24 horas, decrescendo com o passar do tempo.