Intrarenal backflow during retrograde pyelography following kidney transplantation

At the transplantation center of Rigshospitalet , Copenhagen, retrograde pyelography is routinely performed via a ureteral catheter inserted during the operation. Ninety-nine retrograde pyelographies performed within the first days after renal transplantation were reviewed. The clinical records of 30 additional patients who had not been subjected to pyelography were also reviewed. Intrarenal backflow (IRB) was seen in 14 per cent of the pyelograms. Upper urinary tract obstruction (29 cases) was observed with equal frequency in the groups with and without IRB. No relationship was observed between IRB and length of warm and cold ischemia of the graft, urinary tract infection (UTI), donor kidney age and graft function on the day of retrograde pyelography. In 40 per cent of the grafts with irreversible rejection within 60 days after transplantation IRB was found at pyelography in the first days after operation. IRB occurred in only 5 per cent of the kidneys with good long term function. Most frequently IRB was localized to the upper pole but was also observed in other parts of the kidney. IRB may be an early radiographic sign of an impending and irreversible graft rejection. There was no evidence that retrograde pyelography increased the frequency of UTI or the number of episodes of irreversible rejection.