CONSIDERATIONS ON THE WORTHFUL RECOVERY OF RENAL FUNCTION IN HYDRONEPHROSIS

Abstract

We understand the term “worthful recovery” as that the kidney recovers to such an extent that it has the ability of maintaining healthy life by itself alone when the mate kidney happens to be severely damaged or removed in the future.
In this study, we have clinically studied the limitation of the preoperative renal function which promises the worthy recovery after surgery for removing obstruction in hydronephrosis. In other words, we have studied the indication of kidney conservative operation in hydronephrosis from the functional viewpoint
For the examination of the renal function, clearances of PAH, intrinsic inuline and osmorality were mainly employed.
In Tab. 1 clearances in healthy male adults are shown. Results in various degree of hydronephrosis are shown in Tab. 2. To know the tendency of renal function of each degree of hydronephrosis the average values are entered. Here, errors due to dead space of enlarged renal pelvis must naturally be considered: the larger the dead space, the greater the error.
To know the lower limit of renal function which can sustain healthy life we examined 3 groups of patients: chronic nephritis (Tab. 3), acquired healthy solitary kidney (Tab. 4) and nephrostomized hydronephrotic solitary kidney (Tab. 5). From the lowest values of clearance in these groups we found that the very limitation of renal function was as shown in Tab. 6.
For obtaining the data on renal function as exactly as possible in hydronephrosis, with least trouble due to the dead space, we performed nephrostomy for collecting urine. Since it was confirmed by us that the kidney reached an almost stable state 2 weeks to 20 days after nephrostomy (we called it “shortly after”) we evaluated the possibility of the worthful recovery from the renal functions at this stage.
Between the clearances and RA-ratio (relation of the size of renal artery to that of abdominal aorta at the level of branching of the latter) there was only a slight correlation ((Figs. 4, 5, 6).
In B-grade hydronephrosis (low degree) renal functions shortly after nephrostomy were far above the above mentioned limitation (Tab. 7) and all of the cases recovered well as expected (Fig. 7, for instance). In D-grade (middle degree) hydronephrosis renal functions shortly after nephrostomy were not under the limitation (Tab. 6) and also recovered satisfactorily. In E-grade (high degree) hydronephrosis, in which the indication of conservance of the kidney should be earnestly discussed (Tab. 9), only 2 of 6 cases recover ed satisfactorily. The renal functions shortly after nephrostomy were in these 2 cases above or around the limitation.
From the clinical estimations in hydronephrosis we are sure that the above mentioned limitation of renal functions for healthy life can be applicable for selecting the indication of conservative operation of hydronephrosis. If the renal functions shortly after nephrostomy below the limitation, saving the kidney is not worthwhile.
Two cases of interest are here demonstrated: Case 1, 32 yrs male. Advanced hydronephrosis and hydroureter with vesico-ureteral reflux in acquired solitary kidney. Cystography reveals the condition well (Fig. 1). Renal functions following the indwelling catheterization of the bladder are shown in Fig. 2. He is healthy thereafter. As to the consideration of error due to dead space in this case, clearances of 1 hour and 24-hour's examinations are shown in Fig. 3.
Case 2. (6th case in Tab. 9). 18 yrs male. E-grade hydronephrosis as shown in Figs. 8 and 9. On nephrostomy we found that about thick the half of the kidney became thin to 1 to 2mm thick and the remaining parenchyma was not more than 1cm thick. But, the renal functions shortly after nephrostomy were over the limitation, which rendered us to conserve the kidney. The course of renal function after nephrostomy is shown in Fig. 10. Pyelo-uretero-plasty brought good results in renal function.