Lung transplantation in patients in mechanical ventilation before transplantation

Mechanical ventilation before lung transplantation has been identified as a risk factor for early death after surgery. However, several studies have reported patient series in which ventilation assistance was given preoperatively without increasing the rates of postoperative complications and death, apart from increasing time of postoperative intubation. The present retrospective analysis of the postoperative course of patients who had been mechanically ventilated before transplantation encompasses a period of 5 years in our hospital. Eight transplants (7 double- and 1 single-lung procedures) were performed. Six patients (75%) required extracorporeal oxygenation during surgery. Three patients (37.5%) died within 30 days of receiving the transplanted lung. The mean time of intubation after the operation was 10.3 days and the mean stay in the postoperative recovery and intensive care unit was 27.5 days. The most common postoperative complications were respiratory colonization (100%), with infection in 3 patients, and reimplantation injury (50%). Pretransplant mechanical ventilation was associated with high risk in the patient series we report; however, the survival rate observed suggest that such patients should be considered acceptable candidates to receive grafts if indicated.     

Mycophenolates in transplantation

The discovery of mycophenolic acid (MPA) as a potent immunosuppressant, able to inhibit B- and T-cell proliferation by blocking production of guanosine nucleotides required for DNA synthesis, allowed its potential in the field of transplantation to be realized. Mycophenolate mofetil (MMF), an MPA prodrug, has been shown to be an effective immunosuppressant in transplant therapy. Clinical trials in renal, heart, and liver transplant recipients have demonstrated that, in combination with cyclosporine and steroids, MMF therapy can reduce the incidence and severity of acute rejection episodes and improve graft and patient survival as well as graft function. Although MMF is generally well tolerated, optimal therapy may be limited by associated side effects, in particular gastrointestinal (GI) toxicity, which may occur in over 40% of patients. Dose changes resulting from GI side effects may potentially lead to sub-therapeutic dosing and impaired clinical outcomes. An enteric-coated formulation delivering MPA - enteric-coated mycophenolate sodium (EC-MPS) has been developed to improve MPA-related upper GI adverse events. EC-MPS delays the release of MPA, consistent with a functional enteric-coating. Recent clinical trials have demonstrated that EC-MPS is as effective and safe as MMF in both de novo and maintenance renal transplant patients.     

Kidney transplantation. Modern trends in kidney transplantation.

Trends in renal transplantation stem from recognition of the virtues and drawbacks of this kind of treatment and from a better appreciation of the interrelationship between transplantation and dialysis.     

Split-liver transplantation: an underused resource in liver transplantation

Split-liver transplantation is an efficient tool to increase the number of liver grafts available for transplantation. More than 15 years after its introduction only the classical splitting technique has reached broad application. Consequently children are benefiting most from this possibility. Full-right full-left splitting for two adult recipients has been shown to work but is hampered mainly by the dangers of small-for-size transplantation. A solution to this last problem would completely change the scope of split-liver transplantation. Organ allocation systems and collaboration between centers play a crucial role in the chances to let suitable patients profit from this valuable source of extra grafts.     

Combined liver and kidney transplantation in a multicenter transplantation program in Chile

INTRODUCTION: Combined liver and kidney transplantation (CLKT) is an exceptional therapeutic procedure limited to a few diseases with advanced compromise of these organs. Hyperoxaluria type I and polycystic disease are the most frequent indications. The aim of this article was to report our indications and results of CLKT in a multicenter transplantation program in Chile. MATERIAL AND METHODS: Our Excel database was reviewed to select patients who were treated with CLKT between 1993 and July 2004. RESULTS: Among 242 liver transplantations (LT) and 48 kidney transplantations (KT), 7 were CLKT, representing 2.8% of LT and 14.5% of KT. Four patients were women and 3 were male of average age 46.8 years. One patient was a child. Most frequent indications were chronic renal failure associated with terminal liver disease and polycystic disease. One patient needed liver retransplantation due to hepatic vein thrombosis. One patient had a biliary fistula and another had a urinary fistula, treated conservatively. Acute liver rejection took place in 3 cases, 1 of which required antibodies. Two patients died, 1 due to aspergillosis and the other due to vascular complications in the transplanted liver. Actuarial survival rates were 71.4% at 1 and 5 years. Chronic renal failure is not a contraindication to LT. CONCLUSION: CLKT is an acceptable option for these patients.     

Immunosuppression in uterine transplantation

Uterine transplantation (UTx) is the only effective treatment for uterine infertility patients to become genetic mothers. After decades of research, the surgical methods of UTx are very developed. There are numerous factors that affect the results of UTx, such as selection of the donor uterus before transplantation, immunosuppressive therapy post-transplantation, rejection monitoring, and immune tolerance. Studies have shown that immune rejection is a crucial factor affecting the survival rate after organ transplantation. Unlike liver or kidney transplantation, the aim of UTx is to obtain a functional uterus that is able to support successful pregnancy and birth of a healthy fetus. Because of the unique purpose of UTx, its immunosuppressive program is relatively specialized. Some immunosuppressive agents can cause perinatal complications, and inducing immune tolerance is necessary to resolve these side effects. Further understanding of the immune mechanism of UTx and the continuous development of new immunosuppressive agents, combined with the application of assisted reproductive technology, will be more conducive to the realization of UTx to breed offspring.