Evaluation of tissue engineering products for the management of neuropathic diabetic foot ulcers: an interim analysis.

OBJECTIVE: The objective of this prospective, multicentre clinical study is to assess the application of MatriStem MicroMatrix (MSMM) and MatriStem Wound Matrix (MSWM) (porcine urinary bladder derived extracellular matrix) compared with Dermagraft (DG) (human fibroblast-derived dermal substitute) for the management of non-healing diabetic foot ulcers (DFUs). METHOD: A randomised, multicentre study was conducted at thirteen centers throughout the US. It was designed to evaluate the incidence of ulcer closure, rate of ulcer healing, wound characteristics, patient quality of life, cost-effectiveness, and recurrence. Those subjects whose DFUs decreased in size by ≤30% or increased by ≤50% during the standard of care (SOC) phase were randomised into the treatment phase of the study. The study evaluated complete wound closure by eight weeks with weekly device application. A two-week post treatment SOC phase followed the treatment phase for any wounds that did not heal by the end of eight weeks, and wound closure was also evaluated at the end of that period. Ulcer recurrence at 6 months post-treatment was evaluated in the subjects that showed wound healing by the end of the post-treatment SOC phase. Standard adjunctive therapy, including debridement, saline irrigation and foot off-loading, was provided to both arms during the four-week screening period, after which eligible subjects were randomised in a 1:1 ratio, to either the MatriStem (MS) or DG treatment arm. This study was developed to evaluate the hypothesis that the wound outcomes observed after wound management with MS were non-inferior to those of DG after eight weeks. The authors present the planned interim results of this study after one half of the projected enrolment was completed. RESULTS: There were 95 subjects consented and entered into the SOC four-week screening phase of the trial and 56 were randomised into the treatment phase. At the planned interim analysis, there was a significantly lower cost per subject and significant improvement in patient quality of life for the subjects treated with MS compared with those managed with DG. However, there was not a statistically significant difference found during the analysis of the interim data between the two study groups for rate of wound healing or number of subjects with complete wound closure. CONCLUSION: The data from this interim analysis show that MSMM and MSWM provide results for healing DFUs that are similar to the results obtained for DG at a significant quality of life and economic advantage. DECLARATION OF INTEREST: The opinions expressed are those of the authors and not necessarily those of the Department of Veterans Affairs or the United States Government. T.W. Gilbert is employed as the Chief Science Officer and is a stockholder in ACell, Inc., which commercializes MatriStem Wound Matrix and MicroMatrix. None of the other authors have a conflict of interest to declare.

Early report of a randomized comparative clinical trial of Strattice™ reconstructive tissue matrix to lightweight synthetic mesh in the repair of inguinal hernias.

PURPOSE: Biologic grafts are rarely used for inguinal herniorrhaphy. The aim of this study was to compare the clinical outcomes between patients undergoing a Lichtenstein's hernioplasty with a porcine mesh versus a standard synthetic. METHODS: A prospective, randomized, double-blinded multicenter, evaluation of inguinal hernia repair was conducted between 2008 and 2010. Lichtenstein hernioplasty was performed using Strattice™ or lightweight polypropylene (Ultrapro) mesh. Quality of life, pain, overall complication rate, and recurrence were measured. RESULTS: One hundred and seventy-two patients were randomized to Strattice™ (n = 84) or Ultrapro (n = 88). At 3 months postoperatively, there were no differences on the occurrence or type of wound events [RR: 0.98 (95% CI 0.52-1.86, p = 0.69), Strattice™ (15 events) vs. Ultrapro (16 events)]. The mean level of impairment caused by the hernia, assessed by Activities Assessment Scale (AAS), significantly decreased postoperatively in both groups at 3 months (31% Strattice™ and 37% Ultrapro). Patients in the Strattice group reported significantly less postoperative pain during postoperative days 1 through 3 compared to Ultrapro patients. However, the amount of postoperative pain at 3 months, as assessed by the mean worst pain score on a visual analog scale and the Brief Pain Index, was similar between groups (95% CI 1.0-29.3). No hernia recurrences were observed in either group. CONCLUSIONS: Strattice™ is safe and effective in repairing inguinal hernia, with comparable intra-operative and early postoperative morbidity to synthetic mesh. Long-term follow-up is necessary in order to know whether the clinical outcomes of Strattice are equivalent to standard synthetic mesh in patients undergoing Lichtenstein's hernioplasty.

Prophylactic photopheresis and chronic rejection: effects on graft intimal hyperplasia in cardiac transplantation.

BACKGROUND: Despite the decreased incidence of acute rejection episodes and improvements in short and intermediate term graft survival with current immunosuppressive agents, there has been little progress in decreasing the morbidity and mortality from chronic rejection. This phenomenon may, in part, be related to the development of a humoral immune response with increases in anti-HLA antibodies, which presents as accelerated graft arteriopathy with intimal hyperplasia. METHODS: Based on prior experimental work, a pilot, prospective, randomized study was performed in 23 primary cardiac transplant recipients to determine whether the addition of prophylactic photopheresis to a cyclosporine, azathioprine and prednisone regimen was safe and resulted in decreased levels of panel reactive antibodies (PRA) and transplant arteriopathy. RESULTS: There was no difference between the two groups in regard to infection or acute rejection incidence. The photopheresis group had a significant reduction in PRA levels at two time points within the first 6 postoperative months. Coronary artery intimal thickness was significantly reduced in the photopheresis group at 1-yr (0.23 vs. 0.49 mm, p < 0.04) and 2-yr (0.28 vs. 0.46 mm, p < 0.02) follow-up compared with the control group. CONCLUSION: In this small pilot study, photopheresis is a safe, well-tolerated immunomodulatory technique that is capable of decreasing the severity of chronic rejection manifesting as post-transplant graft intimal hyperplasia.

Sirolimus (rapamycin) potentiates cyclosporine in prevention of acute lung rejection.

BACKGROUND: Cyclosporine-based immunosuppressive regimens (INN: ciclosporin) in human lung transplantation continue to result in a high incidence of acute cellular rejection. We investigated the use of sirolimus, a macrolide with structural similarity to tacrolimus, as monotherapy and in combination with cyclosporine in a rodent lung transplant model. METHODS: Orthotopic left lung transplantation was performed in Lewis recipients from Brown-Norway donor rats with syngeneic Lewis-to-Lewis controls. Open biopsies were performed on postoperative day 7, and the severity of acute lung rejection was graded by a pathologist blinded to the protocol. RESULTS: All recipients survived despite the amount of acute rejection seen on examination of the biopsy tissue. Lewis-to-Lewis isografts demonstrated near normal pulmonary architecture. Allogeneic recipients receiving high-dose cyclosporine (25 mg/kg) monotherapy showed mild to moderate acute rejection with some perivascular focal interstitial infiltrates. Recipients receiving low-dose cyclosporine (5 mg/kg) monotherapy or low- or high-dose sirolimus (0.5 or 2.0 mg/kg, respectively) monotherapy demonstrated massive cellular infiltration leading to necrosis and infarction and could not be graded. However, the addition of low-dose sirolimus (0.5 mg/kg) to low-dose cyclosporine (5 mg/kg) demonstrated a significant potentiating immunosuppressive effect, and the addition of high-dose sirolimus (2.0 mg/kg) to low-dose cyclosporine (5.0 mg/kg) demonstrated an even greater effect, with rejection scores better than those obtained with high-dose cyclosporine monotherapy and similar to those obtained with isografts. CONCLUSIONS: This study demonstrates that low-dose sirolimus has a cyclosporine-sparing effect and that a higher dose of sirolimus in combination with cyclosporine strongly protects lung allografts from acute cellular rejection. These results suggest that sirolimus may be indicated as an adjunct to current cyclosporine-based immunosuppressive regimens in clinical lung transplantation.