Preface

Article Outline

• Copyright

It has been over 13 years since Seminars in Pediatric Surgery last reviewed the status of pediatric organ transplantation. Since that time, there have been great strides in transplantation in general and in pediatric transplantation in particular. The papers solicited for this issue focus on the advances in immunosuppression and the impact these advances have on the medical and surgical outcomes. They also focus on issues that are specific for the pediatric population.

The first paper on immunosuppression will highlight the unique differences in pharmacokinetics and side-effect concerns in children. For example, children have a higher metabolic rate, thereby requiring twice daily dosing of sirolimus. The impact of corticosteroids on growth has been a primary impetus for steroid-free immunosuppressive protocols. Next, a review on infectious issues in the pediatric population is provided. Children are unique in that many of the infectious agents are being encountered for the first time after transplant. Some, such as CMV and EBV, carry a high degree of morbidity but can be prevented with oral drugs. Others can be prevented by timely vaccination of transplant candidates.

Historically, a major problem with children after transplant was growth retardation. The extraordinarily high doses of steroids used previously resulted in a population of children who were far below the norm for height. This created various social problems and often led to noncompliance with medication and graft loss. This is now addressable by two approaches: steroid elimination and growth hormone therapy. The results of growth hormone and the possibility of increased rates of rejection are reviewed in depth in the paper by Fuqua. His review suggests that the best combination would be growth hormone before transplant and then maintenance of as low a level of steroids as possible after transplant.

As Succato and Murray note, with the improved graft function and long-term survival, attention can turn to improving quality of life of the transplant recipients. These authors provide a review on puberty and sexuality. Always a hard issue with teens, the added risk of infectious disease resulting from the immunosuppression and interactions of the immunosuppressive medications with birth control and pregnancy make discussions of sexuality that much more important. Although abstinence is the best recommendation, they provide useful information in the selection of birth control and in screening and management of sexually transmitted disease.

As Buell and colleagues point out, a major concern with children who receive a transplant is the extended period of time during which they will be exposed to the malignant potential of immunosuppressive drugs. As noted in both the infectious disease and immunosuppression papers, EBV-associated lymphoma is a much greater problem in children than in adults. This results primarily from the EBV naïve status of the pediatric recipient, who then is exposed to EBV in the face of immunosuppression. The application of potent antivirals, such as ganciclovir and valganciclovir, may lead to a reduction in this disease. With the increased sexuality as children go through their teens, the risk of human papilloma virus (HPV) exposure with its risk of gynecologic cancer is an area of concern. Perhaps over the next several years, as HPV vaccines become part of clinical practice, this particular cancer could be reduced.

This Seminars issue will conclude with five organ-specific reviews by recognized experts in their respective fields. In particular, reviews of the current status of heart, lung, renal, liver, and intestinal transplantation are provided. Although at first glance these reviews have little in common, themes can be identified that are specific for pediatric patients. Although the operations are anatomically very similar to those performed in adults, subtleties necessitated by the small size of the recipients who often receive adult organs increase the complexity of the operations. Specifics of postoperative care, such as particular attention to fluid management in kidney recipients, also differ. But probably the major difference in pediatric transplantation from adults is the spectrum of diseases for which transplantation is offered. For example, biliary atresia is an indication for liver transplantation that is restricted to the pediatric population, whereas hepatitis C, a disease that constitutes the major indication for liver transplantation, in adults is rare. Pancreas transplantation is not even discussed, even though diabetes is the cause of renal failure in about one-third of patients.

In conclusion, the field of pediatric transplantation has matured over the past 13 years. There are still many areas for advancement and perfection of the field. We look forward to seeing where this review stands in relation to those future reviews to come.