Motohiro Kawauchi

Male donor into female recipient increases the risk of pediatric heart allograft rejection

Sixty-one infants and children, 12 years old or younger, who received an orthotopic cardiac allograft between November 1985 and December 1989 were analyzed for the incidence of rejection. Rejection was diagnosed non-invasively within the first 3 months and during the first year. Rejection episodes were diagnosed by signs and symptoms according to previously reported criteria. Multiple regression analysis with recipient age, donor age, donor-recipient weight ratio, number of HLA mismatches, sex of the recipient, sex-encoded minor tissue antigen incompatibility (H-Y: female recipients receiving male donor organ), graft ischemic time, lowest cyclosporine level during the first 2 postoperative weeks, and prophylactic use of OKT3 showed that H-Y was the only significant contributing factor for rejection at 3 months and 1 year (r = 0.308, p < 0.02; r = 0.308, p < 0.02; respectively). Patients were divided into two groups: group 1, 45 patients who were H-Y compatible (male and female recipients receiving female donor hearts); and group 2, 16 patients who were H-Y incompatible (female recipients with male hearts). Patients in group 2 had significantly more episodes of graft rejection than did patients in group 1 by 3 months and by 12 months after heart transplantation (3 months: 2.75 +/- 1.48 versus 1.67 +/- 1.41, p < 0.05; 1 year: 4.80 +/- 1.87 versus 2.59 +/- 1.93, p < 0.01; respectively). There were six grafts lost due to rejection in group 2 (6/15, 37.5%) and 7 grafts lost (7/45, 15.5%) in Group 1 (not significant). Heart transplantation with H-Y incompatibility resulted in a significantly greater incidence of rejection episodes.

Pediatric cardiac xenograft growth in a rhesus monkey‐to‐baboon transplantation model

Abstract: It is unclear that organs from other species could grow successfully in the environment of another species. We evaluated the growth capacity of a cardiac xenograft in a rhesus monkey‐to‐juvenile baboon orthotopic heart transplantation model where there exists a discrepancy of the organ size and its growth rate between donor and recipient species. Eight recipient baboons who survived over 60 days were followed for body weight (BW) and the size of xenografts (left ventricular end‐diastolic volume, LVEDV; left ventricular mass, LVM; and left ventricular posterior wall thickness, LVPWT) by echocardiography at 1 week and monthly after xenotransplantation. One baboon is growing along the normal growth curve. The other three baboons gained BW in parallel with normal growth curve except for a few months after surgery. LVEDV, LVM, and LVPWT increased constantly in these four baboons. In one baboon, BW increased over 1 year to 5.5 kg (which was almost the same as BW of adult rhesus monkey) and then plateaued. LVEDV, LVM, and LVPWT increased until 1 year posttransplantation, but then stopped when BW plateaued. In the other four baboons who did not gain BW because of infectious complications or side effects by immunosuppressive therapy, LVEDV, LVM, and LVPWT did not change significantly. We conclude that a cardiac xenograft from a rhesus monkey can successfully grow and support normal growth of a juvenile baboon, but whether a recipient can grow beyond the donor size is yet unknown.

Visualization of Aortopulmonary Window by Transesophageal Echocardiography

Transthoracic two‐dimensional echocardiography, and Doppler and color flow imaging techniques were utilized to diagnose aortopulmonary window in an infant. Transesophageal echocardiography was used intraoperatively for precise definition of this lesion and its differentiation from other defects in aortopulmonary septation. (ECHOCARDIOGRAPHY, Volume 8, May 1991)