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These results indicate that 18 hr of ex vivo warm perfusion of kidneys is feasible. Furthermore, recovery of renal function during warm perfusion is demonstrated, resulting in immediate function after transplantation. The use of ex vivo warm perfusion to recover function in severe ischemically damaged kidneys could provide the basis for increasing the number of transplantable kidneys.

Background-The potential of a Mesenchymal Stem Cell (MSC) therapy to accelerate the repair of ischemically damaged human kidneys during 24 hours of warm perfusion was evaluated. The hypothesis was that by administering MSC directly to the renal tissue, there would be an improved opportunity for cellular repair mediated by intrarenal paracrine effects. Methods-Studies were performed using the Exsanguinous Metabolic Support (EMS) tissueengineering platform. Five pairs of human kidney allografts from donation after cardiac death (DCD) donors were studied. One human kidney was EMS perfused for 24 hours (control), while its paired kidney was EMS perfused with MSC (1×10 8). The kidneys were evaluated for DNA synthesis, cytokine/chemokine synthesis, cytoskeletal regeneration and mitosis. Results-Treatment with MSC resulted in reduced inflammatory cytokines synthesized by the kidneys. MSC treatment led to a significant increase in the synthesis of ATP and growth factors resulting in normalization of metabolism and the cytoskeleton. Toluidine Blue staining of MSC *

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The horseshoe kidney is the most common anatomical renal variation. It represents a fusion anomaly, mainly at the lower poles, occurring between the 4th and 6th week of gestation. Horseshoe kidneys display a great variation in origin, number and size of the vasculature. Transplantation of these deviant kidneys can be done en bloc or they can be split into two halves and transplanted into two recipients, depending on the number of vessels and the anatomy of the urinary collecting system. A literature review reveals 31 case histories, published between 1975 and 1998. Of these 21 were transplanted into 38 recipients after division and ten were implanted en bloc. Nineteen grafts (41%) showed immediate function and 21 grafts (46%) showed delayed function. Thrombosis and acute rejection, leading to non-function was seen in six grafts (13%). The overall success rate was 87%) with a mean follow-up of 22 months. The results of horseshoe kidney transplantation are good. provided that attention is paid to certain technical details. Because of donor scarcity, horseshoe kidneys should be used for transplantation.

Use of tissue expanders in adults with postpneumonectomy syndrome is an effective means of decompressing the remaining bronchus, thereby leading to a significant improvement in respiratory symptoms. Although 32% of patients required reoperation for complications, each complication was readily correctable.

A study was performed to determine the limiting factors to expanding the donor pool with warm ischemically (WI) damaged kidneys. Canine kidneys were damaged by 30 min of WI, and then either cold stored (CS) in ViaSpan (4 aeC) for 18 h, or warm perfused with exsanguineous metabolic support (EMS) technology (32 aeC) for 18 h, or subjected to combinations of both techniques. The kidneys were autotransplanted with contralateral nephrectomy. In kidneys with WI and CS alone, the mean peak serum creatinine value was 6.3 mg/dL and took 14 days to normalize. In contrast, kidneys where renal metabolism was resuscitated ex vivo during 18 h of warm perfusion demonstrated mild elevations in the serum chemistries (2.6 mg/dL). The damage in kidneys CS for 18 h was ameliorated with 3 h of subsequent warm perfusion and eliminated by 18 h of warm perfusion. In contrast, reversing the order with CS following WI and 18 h of warm perfusion resulted in a time-dependent increase in damage. These results identify hypothermia as a major limiting factor to expanding indications for kidney donation. While hypothermia represents the foundation of preservation in the heart-beating donor, its use in WI damaged organs appears to represent a limiting factor.

Background. Despite significant side effects, chronic systemic immunosuppression remains the backbone of clinical transplantation. We investigated the feasibility of preventing early allorecognition in canine renal allografts using a nonsystemic pretreatment. Methods. The renal vasculature was treated with a bioengineered interface consisting of a nano-barrier membrane during 3 hr of ex vivo warm perfusion. Results. Preliminary feasibility of the immunocloaking technology was established by the following criteria: it is possible to achieve approximately 90% coverage of the vasculature with nano-barrier membrane after 3 hr of ex vivo warm perfusion; covering the luminal surfaces prevents allorecognition as determined by mixed lymphocyte-vascular endothelial reaction; covering the luminal surfaces does not negatively affect renal function as determined by auto-transplant outcomes; and graft rejection is significantly postponed in canine kidneys treated with the immunocloaking technology. In the absence of systemic immunosuppression, untreated control dogs experienced a mean onset of rejection on day 6, whereas in the treated dogs with modified renal vascular luminal surfaces, the mean onset of rejection was significantly delayed until day 30. Conclusions. The ability to postpone, or eventually eliminate, the allorecognition that occurs immediately on reper-fusion could provide a new window of opportunity to introduce adjunct therapies to support tolerance induction. To our knowledge, this is the first time significantly prolonged canine renal allograft survival has been achieved in the absence of systemic immunosuppression or immunologic manipulation of the recipient.