Use of an absorbable mesh to repair contaminated abdominal-wall defects

When polypropylene mesh (Marlex) is used to repair contaminated abdominal-wall hernias, a high incidence of mesh-related chronic infection, drainage, erosion, and bleeding is noted. As an alternative to placing polypropylene mesh in a contaminated field, in the past 18 months we have used an absorbable polyglycolic acid mesh (Dexon) to repair contaminated abdominal-wall defects in eight patients--three with necrotizing abdominal-wall infections, one with an extensive electrical burn of the abdominal wall, three with infected polypropylene mesh from a previous repair, and one whose hernia was covered by a chronically infected scar. In seven of the eight cases, a single sheet of polyglycolic acid mesh was sewn to the fascial margins. In four cases, skin was closed over the mesh; wound packing and subsequent skin grafting were required in the other four. In follow-up studies that ranged from three to 18 months, six of the eight patients developed abdominal-wall hernias at the site of absorbable mesh placement. None of the patients required an abdominal binder. Postoperative hernia development is probable in patients whose defects are repaired with absorbable mesh. However, this complication is balanced against the more serious complications of fistula, bleeding, skin erosion, drainage, and chronic infection, which require removal of the more rigid nonabsorbable meshes in 50% to 90% of cases when the latter are placed under contaminated conditions. Placement of absorbable mesh for temporary abdominal-wall support until wound contamination resolves enhances the likelihood of subsequent successful placement of a permanent mesh.     

Temporary closure of full-thickness abdominal-wall defects with mesh grafts

Introduction: A simple technique is presented here for temporarily covering massive, full-thickness, abdominal-wall defects, when they cannot be closed directly. Methods: The exposed viscera can be covered with a meshed split-thickness skin graft to close the wound and seal off the abdominal cavity from the outside. Once the patient's general condition improves, the epidermal layer of the mesh graft should be removed by dermabrasion to minimize the risk of epidermal cysts, and the defect should be closed either by primary closure or by a local or free flap, depending on the defect size. Received: 24 April 1998 Accepted: 13 October 1998     

Use of chemically extracted muscle grafts to repair extended nerve defects in rats

Nerve regeneration, measured as axonal outgrowth, Schwann cell migration, macrophage invasion, and neovascularisation, was compared after repair of a 15 mm gap in rats' sciatic nerves using autologous muscle grafts made acellular either by freezing and thawing or by chemical extraction. Both extracted and freeze-thawed acellular muscle grafts could be used to bridge the defect. However, axons and Schwann cells, as shown by immunohistochemical staining for neurofilaments and S-100 protein, respectively, grew faster into the extracted muscle grafts than into the freeze-thawed acellular muscle grafts and somewhat more axons were observed in the former graft. There were no significant differences between the two graft types with respect to neovascularisation as showed by staining for endothelial alkaline phosphatase, and limited differences concerning invasion of macrophages (ED1 and ED2) as detected by immunocytochemistry. The results showed that chemically extracted muscle grafts could be used to bridge an extended nerve defect and that such grafts in some aspects were superior to freeze-thawed muscle grafts for extended gaps.     

Use of chemically extracted muscle grafts to repair extended nerve defects in rats.

Nerve regeneration, measured as axonal outgrowth, Schwann cell migration, macrophage invasion, and neovascularisation, was compared after repair of a 15 mm gap in rats' sciatic nerves using autologous muscle grafts made acellular either by freezing and thawing or by chemical extraction. Both extracted and freeze-thawed acellular muscle grafts could be used to bridge the defect. However, axons and Schwann cells, as shown by immunohistochemical staining for neurofilaments and S-100 protein, respectively, grew faster into the extracted muscle grafts than into the freeze-thawed acellular muscle grafts and somewhat more axons were observed in the former graft. There were no significant differences between the two graft types with respect to neovascularisation as showed by staining for endothelial alkaline phosphatase, and limited differences concerning invasion of macrophages (ED1 and ED2) as detected by immunocytochemistry. The results showed that chemically extracted muscle grafts could be used to bridge an extended nerve defect and that such grafts in some aspects were superior to freeze-thawed muscle grafts for extended gaps.     

Use of collagen/chitosan sponges mineralized with hydroxyapatite for the repair of cranial defects in rats

In traumatology, we encounter several clinical challenges that involve extensive bone loss primarily related to trauma, conditions that can be treated with autologous grafts. A good alternative is the use of synthetic biomaterials as substitutes. These polymers provide a suitable environment for the growth of new bone and vascular tissue, which are essential for repair. Collagen/hydroxyapatite composites have proven to be biocompatible and to behave mechanically. Furthermore, the addition of chitosan contributes to the formation of a three-dimensional structure that permits cell adhesion and proliferation, thus improving osteogenesis. The aim of this study was to evaluate bone formation during the repair of bone defects experimentally induced in the skull of rats and grafted with a polymer blend consisting of bovine tendon collagen and chitosan combined with hydroxyapatite. Thirty animals were used for the creation of a defect in the left parietal bone and were divided into three groups of 10 animals each: a control group without biomaterial implantation, a group receiving the blend of collagen and chitosan, and a group receiving this blend combined with hydroxyapatite. Each group was subdivided and the animals were sacrificed 3 or 8 weeks after surgery. After sacrifice, the skulls were removed for macroscopic photodocumentation and radiographic examination. The samples were processed for histological evaluation of new bone formation at the surgical site. Macroscopic and radiographic analysis demonstrated the biocompatibility of the blends. Histologically, the formation of new bone occurred in continuity with the edges of the defect, with the observation of higher volumes in the grafted groups compared to control. Mineralization of sponges did not stimulate bone neoformation, with bone repair being incomplete over the experimental period. In conclusion, mineralization by the addition of hydroxyapatite should be better studied. However, the collagen/chitosan sponges used in this study are suitable to stimulate osteogenesis in cranial defects, although this process is slow and not sufficient to achieve complete bone regeneration over a short period of time.     

生物材料在修补复杂性腹壁缺损中的使用

感染、污染或可能污染的腹壁缺损一直是疝和腹壁外科的治疗难点,主要包括补片感染、肠瘘合并疝、腹腔内脓肿、粪便性腹膜炎病史、造口旁疝修补术、无肠坏死或穿孔的嵌顿性疝、疝修补过程中实施肠切除和复发性切口疝等,上述情况统称为复杂性腹壁缺损.采用传统的合成材料如聚丙烯、聚酯或聚四氟乙烯等来修补,面临着感染、再取出材料和复发的危险.成分分离技术、可吸收补片和自体组织移植等方法由于各种局限性和并发症的存在,应用受到一定的限制.近年来,脱细胞异体真皮基质(acellular dermal matrix,ADM)和其他生物材料的出现,使外科医生能够较安全地一期重建上述复杂性腹壁缺损[1-2].     

Functional repair of rabbit gastrocnemius tendons using carbon fibers

The ability of carbon fibers to form a secure anastomosis with soft tissue will have an important bearing on any future clinical uses. A secure anastomosis in rabbit Achilles tendons has been observed for up to 12 weeks after operation using a locking-weave suture, without immobilization. Impaired function occurred from slippage of the carbon fibers, which began by six weeks after operation, and which increased progressively at 13 and 42 weeks after operation. Satisfactory results were obtained using a modified Bunnell suture (with immobilization) in which the free ends of the carbon fibers were glued together with bone cement. In another study, carbon fibers that were weaved through intact rabbit Achilles tendons did not attach to the tendons during the postoperative time interval studied (18 weeks). It is possible, although difficult, to obtain a functional repair of the rabbit Achilles tendon using carbon fibers.     

The omentum–polypropylene sandwich technique: an attractive method to repair large abdominal-wall defects in the presence of contamination or infection

Background Repair of abdominal wall defects in the presence of contamination or infection continues to be a significant problem for surgeons. The loss of tissue warrants reinforcement of the abdominal wall, preferably by autologous material. However, autologous repair often requires extensive operations that carry a high morbidity. Moreover, the lack of sufficient fascia may be so extensive that insertion of a prosthetic material is inevitable. Polypropylene (PP) is the most appropriate material to use under these circumstances, but without coverage, the mesh will wrinkle and ultimately be extruded. The present report describes an alternative technique for repair of heavily contaminated abdominal-wall defects. Patients Two patients with a very large heavily contaminated abdominal wall defect due to necrotizing fasciitis in one patient and a lion’s bite in the other were treated with the omental sandwich technique. After radical debridement, resulting in a full thickness loss of the abdominal wall, the peritoneum was restored using absorbable polyglactin mesh. The fascial defect was bridged with a PP mesh that was fixed to the adjacent myoaponeurosis and covered with a pedicled omental flap. In both patients the omentum was covered with a split skin. Results Wound healing in both patients was without complications. Both patients had a sufficient abdominal wall, without signs of herniation after a follow up of 4 and 30 months, respectively. Conclusion The omental sandwich technique is an attractive method to repair large abdominal wall defects in the presence of contamination or overt infection.     

Use of Teflon mesh for repair of abdominal wall defects in neonates.

Since 1975, we have employed Teflon mesh sutured to the fascial rim in four newborns with giant omphaloceles, with approximation of skin flaps over the mesh. By stabilizing the anterior abdominal wall, the Teflon mesh has prevented formation of large ventral hernias. The mesh has been retained in place for a year or longer, until the growth of the child permits excision of the prosthesis and fascial approximation without difficulty. A similar technique has been successfully employed in a fifth neonate following transabdominal correction of congenital bilateral eventration of the diaphragm to avoid unacceptable increase in intra-abdominal pressure with primary closure of the abdominal wall. The Teflon mesh appears ideally suited for this technique. It is well incorporated into the fascial rim with minimal foreign body reaction. At the time of secondary repair, the mesh can easily excised from the smooth underlying pseudomembrane covering the bowel. All infants achieved stable abdominal walls by this technique. Three patients have undergone excision of the Teflon mesh and fascial repair at 12, 15, and 36 mo of age without difficulty.     

Systematic review of the use of fibrin sealant in abdominal-wall repair surgery

Purpose  

Our objective was to analyze the advantages and inconveniences associated with the use of fibrin sealant compared with mechanical means for mesh fixation following abdominal-wall surgery.     

Use of carbon fibers in the reconstruction of knee ligaments

Carbon fibers were used to reconstruct the anterior cruciate ligament and other knee ligaments in a consecutive series of 26 (mostly acute) patients who had suffered serious occupation-related injuries. After an average follow-up time of 52.4 months (one patient lost, one patient refused follow-up examination), the anterior drawer at 30 degrees was less than 5 mm (side-to-side difference) in 14 patients, 5-10 mm in six patients, and greater than 10 mm in four patients. Of 24 evaluatable patients, 22 returned to work, including 20 patients who work underground. Chronic pain, recurrent effusion, infection, and tender nodes did not occur in the series. Arthroscopic examination of five patients revealed minimal intraarticular debris.     

Use of tissue expanders in the repair of complex abdominal wall defects

Background/Purpose

Closure of abdominal wall defects in children poses a challenge for pediatric surgeons. We describe a technique using tissue expanders placed either intraperitoneally or in the abdominal wall to aid in the reconstruction of a variety of complex abdominal wall defects.

Methods

The tissue expanders are inserted under general anesthesia. Initial expansion is done in the operating room with attention to peak airway pressure, urine output, and end-tidal carbon dioxide. The expanders are inflated in the outpatient setting via percutaneous access until the calculated inflation volume is achieved. They are then removed; and definitive closure is accomplished using a combination of native tissue flaps, abdominal component separation techniques, biomaterials, and synthetic material.

Results

Six children underwent tissue expansion for treatment of abdominal wall defects (omphalocele, n = 3), trauma (n = 1), and thoracopagus twins (n = 1 pair). One to 4 expanders were used per patient, with all having a successful reconstruction of their abdominal walls. Two to 3 operations were required to restore abdominal domain and consisted of expander insertion, removal with reconstruction, and possible revision of the reconstruction.

Conclusions

Tissue expanders possess a broad range of applications for abdominal wall reconstruction and can be used in patients of all ages.     

Use of dorsal intercostal artery perforator flap in the repair of back defects

Background: The dorsal intercostal artery perforator (DICAP) flap is a well-vascularised flap that is elevated above the dorsal branch of the vertebral segments of the posterior intercostal artery. The aim of this study was to repair back defects using DICAP flaps.

Materials and methods: Eight patients who had undergone reconstruction with DICAP flaps for defects located on the back of the torso due to conditions of various aetiologies between 2011–2014 were included in this study. Patient age and gender, aetiology of the condition, dimensions of the defect and the flap, site of the defect, and postoperative complications were recorded.

Results: Three females and five males were included in this study. The age of the patients ranged between 19–71 years (mean?=?53.6 years). The aetiology was skin tumour in five patients and pressure wound, gunshot injury, and plate screw exposition subsequent to spinal surgery in one patient each. The sites of the defects were successfully closed in all patients, and no flap loss was observed in any patient.

Conclusions: DICAP flaps have some advantages compared to conventional muscle and muscle skin flaps, such as greater protection of muscle functions, less invasiveness, and lower donor site morbidity. This flap has a high mobilisation capacity due to its elevation above nine bilateral perforator arteries. Therefore, the DICAP flap is useful for the repair of median and paramedian back defects. Based on its advantages, it is suggested that the DICAP flap should be considered as a useful option for the repair of back defects.     

A comparison of intraperitoneal prostheses for the repair of abdominal muscular wall defects in rats.

We compared the tissue response to the intraperitoneal implantation of three different prostheses (Gore-Tex, Mersilène, Vicryl-Mersilène) used to repair abdominal wall defects in rats. Vicryl-Mersilène is a new experimental prosthesis made of Dacron (Mersilène) coated with absorbable polyglactin (Vicryl). The least amount of adhesions to omentum and gut was found with Mersilène. Gore-Tex was responsible for the accumulation of neutrophils rather than macrophages mostly collected in close contact with Mersilène and Vicryl-Mersilène. Fibrosis, evaluated by histology and computerized morphometry, was mostly found with Vicryl-Mersilène. This should allow a better incorporation of Mersilène and a tighter anchorage to the abdominal wall, after Vicryl resorption.     

Carbon-fibre versus Marlex mesh in the repair of experimental abdominal wall defects in rats

Large abdominal wall defects were created in Porton-Wistar rats and either left unrepaired (9 rats), or repaired with polypropylene (Marlex) mesh (11 rats), or with an open darn of filamentous carbon (11 rats). A further ten animals had a simple midline skin incision. At 5 months there were gross hernias in the unrepaired animals. Neither repair had resulted in gross recurrence although four of the carbon-repaired animals had bulges through the open weave. Tensiometry of the excised abdominal wall showed no difference in the strength of the two repairs. However, microscopy showed a striking difference-the Marlex had induced a chronic inflammatory response with disorganized collagen, whereas the carbon was not only well-tolerated but acted as a scaffold for well-organized and orientated collagen.