Asymmetric Hypertrophy of Renal Graft after Transplantation

Isao Ishikawa, MD, Division of Nephrology, Department of Internal Medicine, Kanazawa Medical University, Uchinada, Kahoku, Ishikawa 920-02 (Japan) Since the cortical thickness of the graft is thinner at contact with the psoas muscle [1], it is suggested that the local mechanical effect of the recipient affects the graft hypertrophy, i.e. the upper part of the graft facing the upper abdomen hypertrophies more than the lower part facing the minor pelvis where there is no space to move. In order to prove this hypothesis, renal volume was measured using CT scan in its upper, hilar and lower parts. Six recipients (25.3 ± 7.9 years of age, mean ± SD) received grafts from their parents (53.2 ± 5.6 years of age). CT scans were performed from the upper pole to lower pole of the kidney sequentially with a constant slice width (8 mm), 77 ± 43 days before transplantation and 75 ± 28 days after transplantation for grafts and 42 ± 36 days after transplantation for donor’s remaining kidneys. The donor’s left kidney was transplanted in the right iliac fossa of the recipient inside out. The serum creatinine levels in 6 recipients were 1.0–1.5 mg/dl at the time of CT examination after transplantation. The upper or lower parts of the kidney were defined as kidney part above the uppermost scan level or below the lowest scan level where the hilus is included. The hilar part was defined as the renal part with scan slices including the renal hilus. The volumes of the upper, hilar and lower parts were measured in 35 recipients who received the donor’s left kidney in their right iliac fossa besides 6 donor and recipient pairs. The angle of the axis of the graft to the median line in 6 recipients (1.2 ± 5.7°) is significantly more upright than the axis of the left kidney in the donor (-12.4 ± 7.6°) (p < 0.05). Therefore, the volume of the upper part of the graft is underestimated and the volume of the lower part is overestimated because the axis of the graft is more upright.