Katsutoshi Tanda

Experience With Revascularizing Renal Artery Aneurysms: is it Feasible, Safe and Worth Attempting?

PURPOSE We retrospectively evaluated the feasibility and efficacy of surgical revascularization for renal artery aneurysms. MATERIALS AND METHODS Beginning in 1984, 12 patients with renal artery aneurysm underwent renal revascularization regardless of clinical features. Postoperative results were analyzed regarding split renal function, patency of the revascularized arteries, blood pressure control and surgical complications. RESULTS Postoperative renal function was stable or improved in all but 1 case and patency in branched arteries was preserved in 86%. Hypertension in 8 patients was cured in 7 (88%), including 2 with renovascular hypertension, and improved in 1 (12%). Complications were minimal with only 1 ureteral stricture that required reoperation. CONCLUSIONS The majority of renal artery aneurysm cases are amenable to surgical repair. Carefully performed renal revascularization is rewarding in that high blood pressure is better controlled, renal function is improved and the potential risk of rupture is obviated.

Paraganglioma of Urinary Bladder, Visualization with 131I-MIBG Scintigraphy

Three cases with paraganglioma of urinary bladder are described. All cases complained of palpitation, headache and paroxysmal hypertension after micturition. 131I metaiodobenzylguanidine scintigraphy successfully visualized the tumor of the bladder in all three cases.

Parturition in six renal allograft recipients.

Between 1983 and 1994, we studied renal function and neonatal conditions for eight pregnancies and births to six women who had received renal transplants in order to assess the effect of an allograft on pregnancy and its outcome. The gestation period was 34 to 39 weeks (mean 36 weeks and 4 days), and four pregnancies ended before term. All eight babies were delivered by cesarean section. Intrauterine growth retardation (IUGR) was found in both babies of one woman who had been treated with conventional (without cyclosporin) immunosuppression. The serum creatinine level did not change during gestation in any of the women but was elevated after delivery in four. Four mothers suffered from proteinuria (25–364 mg/dl) during gestation, but the proteinuria disappeared after delivery in all but one case. The one exception, persistent proteinuria of 100–200 mg/dl, was assumed to result from the recurrence of the original renal disease (IgA nephropathy). The reduction of creatinine clearance and hydronephrosis of one graft noted during gestation were later reversed. None of the eight babies (four females and four males) was congenitally malformed, and their Apgar scores were 6 to 9 (median 8). They are now 3 months to 11 years old, and seven of them are healthy and show good growth. One of the two IUGR babies has not grown well; her weight and height are more than 1 SD below the mean for her age, and she is mentally retarded and suffers from muscle weakness. Compared with dialysis patients, female renal allograft recipients have a better quality of life because they can safely deliver a child if they observe the criteria for pregnancy established for renal allograft recipients.

Further experience with one-stage repair of severe hypospadias and scrotal transposition. Modifications in the technique and its result in eight cases.

Further experience with one-stage repair of severe hypospadias and scrotal transposition performed in eight patients is reported. Primary success was obtained in six, while one patient was cured by secondary repair. While describing the operative technique with some modifications it was reassured that our parameatal preputial flap is a well vascularized one which can safely and easily be constructed into a neourethra. Advantages of improved “glanulomeatoplasty” and scrotoplasty are also discussed. The method is recommended as highly successful to attain excellent functional and cosmetic results in one stage for severe hypospadias.

Surgical Revascularization in Children with Renovascular Hypertension

Two boys, 11 and 10 years of age, respectively, having renovascular hypertension are reported. Diagnostically, captopril test and renal scintigraphy were useful as pharmacologic probes of the renal arterial stenosis and to determine its laterality, as well for examination of the operative outcome. Both children were rendered normotensive after renal revascularization, one by renal autotransplantation and the other by aortorenal bypass procedure. Renovascular hypertension in children is also discussed.

IN VIVO EFFECT OF A SELECTIVE ENDOTHELIN RECEPTOR ANTAGONIST, BQ‐123, ON RENAL FUNCTION IN CYCLOSPORIN A‐TREATED RATS

To inveslgate the possible involvement of endogenous endothelin (ET) in cyclosporin A (CsA) nephrotoxicity, we examined the renal effects of the selective [125I]ET‐1 binding to porcine aortic membrane (ETA) receptor antagonist, BQ‐123 (BQ), on CsA‐treated rats. An osmotic minipump filled with BQ or its vehicle (saline), was subcutaneously implanted and animals were treated with CsA (50mg/kg/d, i.p.) for 4 d. In both BQ‐and its vehicle‐treated rats, the 24‐hour urine volume, urinary N‐acetyl‐D‐glucosaminidase (NAG) excretion, urinaryCa/creatinine (Cr) and urinaryNAG/Cr ratios were significantly increased compared with those before administration of CsA. In contrast, after administration of CsA, urinary Cr excretion was significantly decreased in both rat groups. Although urinary NAG excretion and the NAG/Cr ratio in the rats treated with BQ were significantly increased compared with those treated with saline, the serum Cr levels in BQ‐treated rats were significantly lower than those in saline‐treated rats. Urinary immunoreactive ET‐1 (irET‐1) excretion in all animals was significantly increased after administration of CsA. There were no significant differences in urinary irET‐1 excretion in both BQ‐treated and saline‐treated rats with and without CsA. Expression of irET‐1 was seen in the cytoplasm of renal tubules, but the degree of expression was similar in the BQ‐treated and saline‐treated rats on CsA. In the BQ‐treated rats, small round areas with high grain densities over the glomeruli in the cortex and vesa recta bundles in the outer medulla were masked by the antagonist action of BQ. On microscopic examination of autoradiograms, the numbers of autoradiographic grains were clearly decreased in the glomeruli and vessels, which confirmed the presence of ETA. It was concluded that: (1) BQ had no effect on the products and release of ET‐1; (2) BQ could not entirely prevent CsA nephrotoxicity in rats; (3) BQ increased the tubular damage caused by CsA.

Endothelin A receptor antagonist reduces renal vasoconstriction induced by mechanical manipulation of renal artery.

The purpose of this study was to make a model of renal vasoconstriction induced by mechanical manipulation of the renal artery and to investigate the influence of endothelin (ET) in renal vasoconstriction. Renal arteries of anesthetized rats were stretched with a 30-gram weight for 5 min, and released. Renal blood flow (RBF) was monitored with a laser flowmeter. To determine the role of ET, a selective ETA receptor antagonist, BQ-123 (0.1 and 1 mg/kg) was administered into the aorta. The manipulation was invariably followed by a flow reduction of about 57% after temporary hyperemia. RBF returned to the basal level 5 min after the release. BQ-123 partially, but significantly, inhibited the mechanical manipulation-induced reduction of RBF in a dose-dependent manner. These results suggest that endogeneous ET may play an important role in renal vasoconstriction induced by mechanical manipulation of the renal artery.