Repair of cloacal exstrophy, omphalocele, and gastroschisis using porcine small-intestinal submucosa or cadaveric skin homograft

Use of Cadaveric Skin Graft for Staged Gastroschisis Repair in a Premature Infant

Gastroschisis is a congenital abdominal wall defect that, when simple, has excellent overall outcomes. However, morbidity increases with prematurity. A staged approach to closure is often needed until the infant can tolerate definitive repair. We demonstrate the novel use of cadaveric skin allograft as a defect patch, exploiting a tolerant neonatal immune system for long-term durable coverage. A 580-g, 26-week-gestation boy was born with gastroschisis. Primary closure was not possible, necessitating staged closure. After initial silo placement, neither the fascia nor the skin could be closed. Therefore, cadaveric skin was utilized for coverage: there was 100% take, no wound care needs, and no acute rejection. He was discharged at 4 months tolerating full feeds. At 6 months signs of rejection ultimately manifested, and he underwent uneventful elective graft excision and fascial closure. We offer this as a useful option for management of staged gastroschisis closure in an extremely premature infant.

Are biologic grafts effective for hernia repair?: a systematic review of the literature

Biologic grafts for hernia repair are a relatively new development in the world of surgery. A thorough search of the Medline database for uses of various biologic grafts in hernia shows that the evidence behind their application is plentiful in some areas (ventral, inguinal) and nearly absent in others (parastomal). The assumption that these materials are only suited for contaminated or potentially contaminated surgical fields is not borne out in the literature, with more than 4 times the experience being reported in clean fields and the average success rates being higher (93% vs 87%). Outcomes prove to be highly dependent on material source, processing methods and implant scenarios with failure rates ranging from zero to more than 30%. Small intestinal submucosa (SIS) grafts have an aggregate failure rate of 6.7% at 19 months whereas acellular human dermis (AHD) grafts have a failure rate of 13.6% at 12 months. Chemically cross-linked grafts have much less published data than the non-cross-linked materials. In particular, the search found 33 articles for SIS, 32 for AHD, and 13 for cross-linked porcine dermis. Furthermore, the cumulative level of evidence for each graft material was fairly low (2.6 to 2.9), and only 1 material (SIS) had level 1 evidence reported in any hernia type (inguinal and hiatal). Together, biologic grafts have published evidence showing success rates better than 90% overall and more than 2000 years of cumulative implant time. Improvements in materials, techniques, and patient selection are likely to improve these numbers as this field of surgery matures.

Contemporary postnatal surgical management strategies for congenital abdominal wall defects

Early definitive closure of abdominal wall defects is possible in most cases. Staged reduction does offer distinct advantages, and mortality and morbidity may be better. Risk stratification may produce outcome and tailor management of difficult cases in the form of a clinical pathway. Stem cell technology may, in the future, offer the ideal allogenic prosthesis in complex cases.

The use of Surgisis for abdominal wall reconstruction in the separation of omphalopagus conjoined twins

Abdominal wall reconstruction in omphalopagus twins poses a difficult reconstructive challenge, as separation often results in a large abdominal wall defect. A number of options are available for closure, including tissue flaps, expanders and patches made of foreign material. Surgisis is a new biodegradable small intestine scaffolding substrate that permits tissue in-growth and results in a permanent durable scar. We describe its use in abdominal wall reconstruction after separation of a set of conjoined twins. A set of omphalopagus conjoined twins shared liver and abdominal wall. After separation at 6 months of age, Twin A's abdomen could be closed primarily, but Twin B could not. A 4-ply Surgisis mesh was used in the upper abdominal closure, and a skin flap was created, to completely cover the patch. Both twins survived the operation. A small portion of the skin flap over the Surgisis broke down, healing by secondary intention. In follow up of over 18 months post procedure, there have been no wound infections and the abdominal wall is intact with no evidence of a hernia. Surgisis can be successfully used for the reconstruction of complex abdominal wall defects in the pediatric patient, including reconstruction after separation of conjoined twins.

Delayed three-stage closure of giant omphalocele using pericard patch

The management of giant omphaloceles in a single operative approach is quite difficult. If performed as a single-stage procedure, postoperative complications are encountered, which are usually related to significant changes in intra-abdominal pressures, compromise of interior venous blood return ,and hemodynamic and respiratory instability due to diaphragmatic elevation. We report the case of a giant omphalocele that required a three-stage delayed closure and was managed using bovine pericard patches. The procedure of staged application of pericard patches is described. Delayed staged closure has the advantage of avoiding multiple surgical procedures in the neonatal period and reduces morbidity in the management of giant omphaloceles.

Extracellular matrix as a bioactive material for soft tissue reconstruction

The extracellular matrix (ECM) directs all phases of healing following trauma or disease and is therefore a natural source of prosthetic mesh material that can be used strategically to induce the repair and restoration of soft tissues following surgery. Biomaterials such as Surgisis (Cook Biotech Incorporated, West Lafayette, IN, USA), which are derived from natural ECM, provide the extracellular components necessary to direct the healing response, allow for the proliferation of new, healthy tissue and restore tissue integrity to the damaged site. The 3-D organization of these extracellular components distinguishes the Surgisis mesh from synthetic materials and is associated with constructive tissue remodelling instead of scar tissue. Common features of this ECM-assisted tissue remodelling include angiogenesis, recruitment of circulating progenitor cells and constructive remodelling of damaged tissue structures. The tissue response to this biologic mesh is discussed in the context of recent reports on clinical hernia repair.

Repair of the abdominal donor-site fascial defect with small intestinal submucosa (Surgisis) after TRAM flap breast reconstruction

We report the successful use of Surgisis in the repair of the abdominal donor site fascial defect following a free transverse rectus abdominis myocutaneous (TRAM) flap breast reconstruction. No abdominal wall weakness in the flap donor site was evidenced by a series of clinical examinations to at least 14 months after Surgisis placement. A well-formed and thickened fascial layer at the abdominal donor fascial repair site was revealed by computed tomography scan. This objective finding, along with our clinical observation, supports the use of Surgisis for repair of the abdominal donor site fascial defect following a TRAM flap harvesting.

Management of complicated gastroschisis with porcine small intestinal submucosa and negative pressure wound therapy

INTRODUCTION

In almost all cases of gastroschisis, fascial closure may be achieved primarily or after silo reduction. Rarely, fascial and skin closure are impossible. We report our experience with visceral coverage in complicated cases of gastroschisis with porcine small intestinal submucosa (SIS) augmented by negative pressure wound therapy (NPWT).

METHODS

Over a 3-year period, 55 infants with gastroschisis were managed. In 3 of these cases, fascia and skin could not be approximated safely after complete reduction of abdominal viscera with a spring-loaded silo. Visceral coverage in each case was achieved with 0.42-mm-thickness Surgisis ES (Cook Surgical, Bloomington, Ind) that was sewn to the fascial edges. Negative pressure wound therapy was then initiated at 75 mm Hg over the exposed SIS using vacuum-assisted closure.

RESULTS

In each case, granulation tissue developed quickly and was followed by complete epithelialization. Two patients subsequently developed umbilical hernias.

CONCLUSION

We have successfully used SIS augmented by NPWT in the management of 3 infants with complicated gastroschisis. In the rare situation in which fascial closure cannot be achieved, the combination of SIS and NPWT can provide a safe and effective means of abdominal wall closure.

Human embryoid body-derived stem cells in co-culture with bladder smooth muscle and urothelium

OBJECTIVES

Human pluripotent stem cells have excellent regenerative abilities, making them attractive in bladder regeneration. Porcine small intestinal submucosa (SIS) is an established matrix well-suited to the urinary tract. We evaluated the ability of human embryonic germ (hEG) cell-derived stem cells to form a composite graft on SIS, grown alone or in combination with human bladder smooth muscle cells (SMCs) or urothelial (URO) cells.

METHODS

The hEG cell-derived cell line SDEC had the best-fit profile for smooth muscle, as determined by its gene and protein expression. SDEC cells were seeded on SIS, either on its serosal or mucosal surface, and cultured for 7 or 14 days. Co-cultures of stem cells with URO cells or SMCs were also assessed under similar conditions. The grafts were analyzed by histologic examination for cell growth, morphology, and matrix penetration.

RESULTS

SDEC cells grew in a monolayer on SIS, with a marked increase in three-dimensional growth when co-cultured with URO cells or SMCs. Penetration of the matrix was evident when seeded on the rough surface of the SIS, progressing with time. Stratification of the cell layers occurred on the smooth side of the SIS.

CONCLUSIONS

This is the first description of hEG cell-derived stem cells in co-culture with bladder cells. hEG cell-derived stem cells grow well on SIS even when seeded at low concentrations in the presence of bladder cells (URO cells or SMCs). These composite grafts will be ideal to evaluate the in vivo functional characteristics of stem cells using an animal model of bladder regeneration.