Incontinence rates after cutting seton treatment for anal fistula.

OBJECTIVE: To determine the incidence of anal incontinence after the use of cutting seton treatment for anal fistula. METHOD: Literature searches were performed on PubMed, MEDLINE and Google Scholar using the words 'cutting seton(s)', 'seton(s)' and 'anal fistula'. An analysis of the data in the collected references was performed. RESULTS: The average rate of incontinence following cutting seton use was 12%. The rate of incontinence increased as the location of the internal opening of the fistula moved more proximally. In the studies that described the types of incontinence, liquid stool was the most common followed closely by flatus incontinence. Incontinence associated with the treatment of fistulas defined as nonspecific cryptoglandular in nature was 18%. CONCLUSION: The high incontinence rates that result from the use of cutting setons suggest that this commonly used therapy can damage the continence musculature. Other techniques that do not involve cutting the sphincter, when available, should be preferred, especially for higher fistulas.

Repair of experimental Achilles tenotomy with porcine renal capsule material in a rat model.

Porcine small intestinal submucosa (SIS) is a collagenous acellular matrix which has found substantial utility as a tissue growth scaffold. In the present study, the utility of porcine renal capsule matrix (RCM) was compared to SIS in a rat Achilles tenotomy repair model. Groups of rats underwent surgical tenotomy followed by either no repair, repair with a SIS graft, or repair with a RCM graft. The weight-bearing ability of the manipulated limb was evaluated for 10 days following surgery using a subjective scale. Tenotomy sites sampled 28 days after surgery were numerically graded for degree of histologic change. There were no statistically significant differences between groups with respect to return to weight-bearing ability (p >or= 0.05) or degree of histologic change (p >or= 0.001); however, a non-significant trend suggested that rats treated with SIS or RCM experienced a faster return to limb function than untreated rats, and RCM-treated rats had slightly higher scores for degree of histologic change, suggesting a more rapid repair of the tenotomy site than in SIS-treated or untreated rats. The harvested tenotomy sites in all treatment groups were characterized by marked fibroplasia and presence of macrophages. Remnants of SIS surrounded by macrophages and multi-nucleated giant cells were still present in some rats, however remnants of RCM were not observed, suggesting more rapid incorporation of RCM. The results show that RCM is equivalent to SIS as a material for repair of Achilles tendon injury and merits further study in other tendon injury models.

Use of porcine renal capsule matrix as a full-thickness dermal wound-healing material in rats.

OBJECTIVE: To compare the utility of porcine renal capsule matrix (RCM) with porcine small intestinal mucosa (SIS) in a rat full-thickness skin wound model. METHOD: Groups of rats had surgically-created wounds filled with either SIS or RCM. On each rat a contralateral wound was left unfilled (RCM-U or SIS-U). Wound diameter was measured 3, 7, 12, 17, 26 and 30 days after creation. Wound sites sampled 3, 7, 14, 28, 42 and 56 days after wound creation were numerically graded for degree of histologic change and for collagen content, based on intensity of trichrome staining. RESULTS: Wounds in all groups rapidly contracted to less than 50% of the original diameter within 12 days. There were no differences in wound diameter between RCM- and SIS-treated wounds at any time point, but these wounds had significantly greater (p < 0.001) diameters than their unfilled counterparts on days 7, 12 and 17. There were no differences in histologic scores or trichrome-staining scores between RCM- and SIS-treated wounds and their unfilled counterparts at any time point, except for a greater (p < 0.05) histologic score in SIS-treated wounds compared with unfilled controls on day 14. In both treatment groups an acute inflammatory response at the wound site was soon replaced by an influx of macrophages and fibroblasts. CONCLUSION: The results show that RCM is equivalent to SIS for the treatment of full-thickness wounds and that these materials may enhance wound healing in terms of wound-tissue collagenisation and maturation. These materials therefore merit further study in other wound-care models.

An investigation of the long-term bioactivity of endogenous growth factor in OASIS Wound Matrix.

OBJECTIVE: To examine the retention and bioactivity of endogenous FGF-2 after prolonged storage within a complex matrix. FGF-2 is a growth factor found in OASIS Wound Matrix, a purified collagen wound-care product containing other endogenous components of the extracellular matrix. METHOD: FGF-2 content was measured by ELISA. FGF-2 activity was measured using an in vitro bioassay in rat pheochromocytoma (PC12) cells. RESULTS: FGF-2 content ranged from 15.3 ng/g to 84.3 ng/g. The bioassay showed that the FGF-2 retained in the matrix was present in a bioactive form able to cause differentiation of cells in culture. CONCLUSION: The results demonstrate that wound-care products can be developed to retain their bioactivity over time and that inherently unstable purified growth factors are preserved if stored as bound factors within their natural extracellular matrix. The results also suggest that use of acellular matrices containing active growth factors would have advantages in terms of simplicity and cost over purified recombinant growth factor therapies.

Vascular endothelial growth factor in porcine-derived extracellular matrix.

An extracellular matrix (ECM) derived from the submucosa of the porcine small intestine (SIS) has been shown to induce angiogenesis and host tissue remodeling when used as a xenogeneic bioscaffold in animal models of wound repair. In the present study, we compared the in vitro effects of SIS ECM extracts to several purified angiogenic growth factors on human dermal microvascular endothelial cell (HMEC) growth patterns. The SIS ECM was shown to induce tube formation from HMEC in a three-dimensional fibrin-based angiogenesis assay in a manner similar to that caused by the addition of vascular endothelial growth factor (VEGF). This tube formation was blocked in the presence of anti-VEGF neutralizing antibody. Western blots and ELISA procedures showed that the SIS ECM contains as much as 0.77 ng VEGF/g SIS. The closely related endothelial cell mitogen, platelet-derived growth factor (PDGF), was not detectable in the SIS extracts. We conclude that VEGF is present in the SIS extracellular matrix. The role of VEGF in SIS-induced wound repair remains unknown, but its presence in the ECM makes it a possible contributor to the angiogenic effect of SIS when this ECM is used as a tissue repair scaffold in animal models of wound repair.

Glycosaminoglycan content of small intestinal submucosa: a bioscaffold for tissue replacement.

Small intestinal submucosa (SIS) is a resorbable biomaterial that induces tissue remodeling when used as a xenogeneic tissue graft in animal models of vascular, urologic, dermatologic, neurologic, and orthopedic injury. Determination of the composition and structure of naturally occurring biomaterials such as SIS that promote tissue remodeling is necessary for the greater understanding of their role in wound healing. Since glycosaminoglycans (GAGs) are important components of extracellular matrix (ECM) and SIS is primarily an ECM-based material, studies were performed to identify the species of glycosaminoglycans present in SIS. Porcine SIS was chemically extracted and the extracts were analyzed for uronic acid. The extractable uronic acid content was determined to be 47.7 micromol/g (approximately 21 microg GAG/mg) of the dry weight of the SIS tissue. Using electrophoretic separation of GAGs on cellulose acetate membranes, hyaluronic acid, heparin, heparan sulfate, chondroitin sulfate A, and dermatan sulfate were identified. Digestion of specific GAGs with selective enzymes confirmed the presence of these GAG species. Two GAGs common to other tissues with large basement membrane ECM components, keratan sulfate and chondroitin sulfate C, were not detected in the SIS extracts. Identification of specific GAGs in the composition of the ECM-rich SIS provides a starting point toward a more comprehensive understanding of the structure and function of this naturally occurring biomaterial with favorable in vivo tissue remodeling properties.

Infective endocarditis in a collegiate wrestler.

A 21-year-old collegiate wrestler was admitted to the hospital suffering from acute left lower quadrant abdominal pain. Blood cultures taken at the time of admission showed Staphylococcus aureus. The results of a computed tomography scan and a two-dimensional echocardiogram were consistent with a diagnosis of infective endocarditis. Therapy consisted of a 14-day hospitalization, a 28-day course of parenteral antibiotics, and subsequent follow-up visits. He returned to full participation in wrestling after 15 weeks.