Tissue reaction to porcine intestinal Submucosa (CorMatrix) implants in pediatric cardiac patients: a single-center experience.

BACKGROUND: Decellularized porcine small intestine submucosa (CorMatrix, Atlanta, GA) patches have been used in the repair of congenital heart malformations. Tissue reaction to the material may create hemodynamic dysfunction and necessitate explantation. We reviewed our series of congenital cardiac patients who had a reoperation after the implantation of CorMatrix patches. METHODS: Medical records of pediatric cardiac patient who received CorMatrix patches and those of patients who underwent reoperation were reviewed. Routine histologic sections of explanted CorMatrix specimens were examined. RESULTS: Of 25 patients who had received CorMatrix patches during cardiac operations at our institution, 6 patients had undergone reoperations. All patients had hemodynamically significant lesions at the site of the CorMatrix implantation. Explanted specimens were associated with an intense inflammatory reaction consisting of numerous eosinophils, histiocytes, and plasma cells, with accompanying granulation tissue and fibrosis. CONCLUSIONS: Reaction to implanted CorMatrix patches may cause hemodynamic dysfunction and produce an intense, predominantly eosinophilic inflammatory response with developing fibrosis. Although our report is limited to a small sample of congenital cardiac patients, one should take precautions in its use in pediatric cardiac patients, and long-term follow-up is warranted.

Understanding acute apophyseal spinous process avulsion injuries.

Apophyseal spinous process avulsion injury was first described in 1941. Since then, there have been sparse additional reports in the literature. The authors report their second case, involving an elite adolescent tennis player. The patient underwent surgical excision of the avulsed spinous process 12 weeks after initial presentation and experienced complete resolution of back pain. The authors provide the first reported histopathological analysis of the avulsion fracture site in the literature for both of their cases. The avulsion injury of the interspinous ligament was characterized by hypercellular fibrocartilage tissue, similar to that seen in severe Osgood-Schlatter's disease. The key physical examination finding in patients with avulsion spinous process fractures is acute tenderness directly over the fracture site that worsens with flexion rather than extension (unlike in spondylolysis). Patients should have routine radiographs, including dynamic flexion-extension views, magnetic resonance imaging, and computed tomography. The authors conclude that after 6 months of nonsurgical management for an athlete, surgical excision should be offered as an alternative. In both of their cases, nonsurgical management failed. Surgical excision offers definitive and simple treatment, as well as early return to athletic activities. Both patients were allowed to return to their competitive level of performance 6 weeks after surgery.