RESUMO
The authors have studied 86 patients with staghorn calculi who underwent preoperative quantitative renal scintigraphy. 50 of them (63 kidneys) had one or two follow-up scans between 1 and 9 years after the operation. These scintigraphic data were compared with those of I.V.U. These 50 patients had undergone surgery on 60 kidneys (12 pyelotomies only, 26 pyelotomies associated with limited nephrotomies, 18 extended nephrotomies and finally 4 bi-value nephrotomies). In 46 of these patients, the urine became definitively sterile and there was no recurrence of lithiasis in any of them. These quite exceptional conditions were such that it is possible to bear in mind only the operative technique in assessing the possible harmful consequences of each type of operation. The authors clearly show that the threat to function of the kidney which has been operated upon is more threatened when there has been a nephrotomy and when such a nephrotomy has been more extensive. A limited nephrotomy is associated with a mean loss of (% of renal function. Extended nephrotomies or more than 3 cm result in a loss of function of approximately 22%. Large bi-value nephrotomies result in a 36% loss of function. Simultaneous study of scintigraphic scans and I.V.U. revealed that a loss of 1 cm in height of the renal parenchyma corresponds to a functional loss of 10% as determined by scintigraphy. Of basic importance is the fact that the impairment caused by nephrotomies remains stable and does not worsen with the passage of time.
