ABSTRACT
Clearances of inulin and para-aminohippurate (PAH) were studied before as well as three to nine years (average 5½) after surgery in 35 cases of primary hyperparathyroidism. The preoperative inulin clearance ranged from 18 to 105 (average 67) and the PAH clearance from 61 to 666 (349) ml/min/1.73 m2 BSA. In the follow-up studies clearances of inulin and PAH were, on the whole, well maintained both in subjects with normal as well as in cases showing depressed clearance values before surgery. In fact, a slight but statistically significant increase of inulin clearance was demonstrated in the material as a whole, whereas no significant change occurred in PAH clearance.
The renal concentrating capacity was estimated before and after operation in 22 of the patients. An increase was almost regularly observed postoperatively but the concentrating capacity remained subnormal in almost half of the subjects studied. The changes in the concentrating capacity and clearances of inulin and PAH did not always run parallel.
The renal clearance of phosphate was studied simultaneously with inulin and PAH clearances. Phosphate clearance decreased after surgery concomitantly with an elevation of serum phosphorus. However, restoration to the normal was not always obtained.
Arterial hypertension was present in 40 per cent of the patients before and/or after surgery. Only grade I-II eye ground changes were found. Blood pressure was easily controlled by hypotensive drugs.
A spontaneous disappearance or a decrease in the number of kidney stones was demonstrated radiologically at the follow-up studies in almost half of the patients. In only two subjects were additional kidney stones found. It is concluded that, following surgical treatment of hyperparathyroidism, the long-term outcome regarding renal function may be more favourable than has hitherto been thought.