Renal Dilatation Research Articles

Renal pelvicalyceal dilation in antepartum pyelonephritis: Ultrasonographic findings

The purpose of the present study was to determine whether pregnant women with pyelonephritis have differences of pelvicalyceal systems, compared with normal pregnant control subjects, that might predispose to upper urinary tract infection. Ultrasonographic examination of both kidneys in coronal and axial planes of 24 women with clinical pyelonephritis and positive urine cultures was compared with results in control subjects matched for gestational age, parity, and race. Women with right or bilateral pyelonephritis had increased dilation of the right calyceal system, compared with controls (1.7 em vs 0.8 em, p \\lt 0.001). Renal pelvis volume was increased as well (29.3 vs 5.5 cm3, p \\lt 0.001 ). Renal pelvicalyceal dilation in antepartum pyelonephritis was significantly increased compared with normal physiologic dilation of pregnancy. Follow-up nephrosonography in a small number of women (N = 10) after treatment of pyelonephritis did not reveal a consistent decrease in renal dilation, suggesting that dilation of the renal pelvis may antedate pyelonephritis. Further study of this phenomenon is warranted.

Oxalate crystal deposits in renal tubules and cystic changes in 5/6 nephrectomized and normal rats.

Although the mechanism responsible for the genesis of acquired renal cysts in hemodialysis patients has not been clearly defined, the authors suggested that obstruction of the nephron by deposition of oxalate crystals may be an important factor. The present study was undertaken to examine this possibility in an experimental setting. Ten 5/6 nephrectomized rats were given daily subcutaneous injections of 5 mg sodium oxalate and allowed free access to saccharin sweetened water containing 2 mg/ml sodium oxalate. Six other 5/6 nephrectomized rats were controls. In addition, eight healthy rats received 10 mg sodium oxalate for 30 days. The earlier appearance and severe degree of tubular dilatation in oxalate-treated 5/6 nephrectomized compared with untreated 5/6 nephrectomized rats and the presence of renal tubular dilatation with oxalate deposits in normal rats treated with oxalate sodium are likely to be due to tubular obstruction or stenosis caused by oxalate deposition. In conclusion, oxalate deposits in the renal tubules seem to be an important factor in the formation of acquired renal cysts in chronic renal failure.

Results of Renal Artery Balloon Angioplasty Limit its Indications

Abstract Percutaneous transluminal balloon angioplasty (PTA) of 83 renal artery lesions in 55 patients was done because of renal failure in eight patients, hypertension in 35, renal failure and hypertension in 11, and polycythemia in one patient. Early results in 38 patients with arteriosclerosis showed five (13%) were worse and 13 (34%) were unchanged. Twenty patients (53%) with arteriosclerosis were initially cured or improved; however, seven of these patients had recurrence in 4 to 48 months. Ultimately, only 13 of 38 patients with arteriosclerosis (34%) were cured or improved (mean follow-up 22 months). Nine patients with fibromuscular dysplasia required 17 dilatations of arteries (three bilateral and five repeat), resulting in eight patients (89%) who were cured or improved. Selection of patients with hypertension by medical failure while receiving three or more hypertension medications or by lateralizing renal vein renin values yielded benefit in 17 of 26 patients (65%). Five of six patients with transplant stenosis of the renal artery and hypertension were cured or improved at mean follow-up of 18 months. Overall technical results of 83 artery dilatations were as follows: good, 58 (69%); fair, 10 (12%); poor or unsatisfactory, 16 (19%); these were judged with a blinded radiologic review. No patient suffered main renal artery thrombosis. There were 16 patients with complications of dilatation (morbidity rate of 29%). Nine patients subsequently had renal artery surgery from the same day to 64 days later with good results in all patients except one. We conclude that transluminal renal artery dilatation is a technique that should be restricted to use in patients with fibromuscular dysplasia, transplant stenosis, and very few arteriosclerotic lesions. (J VASC SURG 1988;8:300-6.)

Fetal ureteric reflux.

Seven babies (six male, one female) with ureteric reflux, all of whom had antenatal renal dilatation, are described together with one other baby who was found to have gross ureteric reflux when investigated following an acute urinary infection at the age of 9 days. There was a strong probability that all of the babies had fetal ureteric reflux (FUR). Radioisotope studies demonstrated parenchymal damage in three of seven and reduced function in four of 10 refluxing kidneys. Subsequent investigation showed no increase in the areas of parenchymal damage but there was evidence that function in some kidneys had deteriorated. It was thought that this was due to disturbances in inter-renal or renal-child related growth velocities. A plea is put forward for more detailed postnatal examination of babies whose urinary tracts show evidence of dilatation antenatally.

Preclinical toxicology studies with the lipid-regulating agent gemcadiol

Gemcadiol is a medium-length diol moiety with lipid-regulating properties in animals and man. The compound was not toxic when single doses were administered to rodents with the lethal dose greater than 7000 mg/kg in rats and mice. Rats treated for 13 or 52 weeks with 30 to 300 mg/kg had reversible food intake suppression and weight gain inhibition, decreased blood cholesterol, slight anemia, and generally dose-related but reversible decreases in glucose, and increases in alkaline phosphatase and blood urea nitrogen. Liver weights were increased, and there was accompanying hypertrophy and increased cytoplasmic eosinophilia of hepatocytes with associated peroxisome proliferation. Rats treated for 52 weeks also had mild renal tubular dilatation. Dogs given 25 to 300 mg/kg of gemcadiol for up to 52 weeks tolerated the compound better than rats. Effects related to compound administration were elevated serum alanine aminotransferase activity in female animals only, and microscopic cytoplasmic vacuolation and hyaline body formation in both sexes. Monkeys given 25 to 300 mg/kg gemcadiol for 13 weeks had slightly decreased serum cholesterol and slightly increased serum creatine phosphokinase. Teratology studies in rats or rabbits indicated no teratogenic response. Gemcadiol affects principally the liver, and the hepatic alterations seen in rats and dogs may reflect compensatory manifestations of altered metabolism related to the lipid-regulating activity of the compound.

Ochratoxin A Carcinogenesis in the (C57BL/6J × C3H)F<sub>1</sub> Mouse<xref ref-type="fn" rid="FN1">2</xref><xref ref-type="fn" rid="FN2">3</xref>

The potential carcinogenic effects of the mycotoxin ochratoxin A [(OA); CAS: 303-47-9] were assessed in a 24-month feeding study in male and female (C57BL/6J X C3H)F1 (B6C3F1) mice. The mice were assigned to 3 groups of 50 males and 50 females each; group 1 mice were the controls, group 2 mice were fed 1 ppm OA, and group 3 mice were fed 40 ppm OA. Renal neoplasms, both carcinomas and adenomas, were found only in male mice of the 40-ppm dose group. Fourteen of 49 animals that survived at least 20 months had neoplasms morphologically consistent with renal carcinoma. Renal adenomas were present in some of these mice and in other 40-ppm-group males, making a total of 26 mice with renal adenomas. All male mice of the 40-ppm dose group had nephropathy characterized by varying degrees of renal tubular dilation, attenuation and hyperplasia of lining epithelium, and proliferation of regenerative tubules. Females of the 40-ppm dose group had similar but less severe renal changes but no carcinomas or adenomas. Compound-related renal lesions were absent in the 1-ppm dose group. The incidence of hepatocellular neoplasms was slightly increased in male and female mice fed diets containing OA. These results indicate that OA is a renal carcinogen in male B6C3F1 mice and a hepatic carcinogen in female mice of this strain.

Percutaneous transluminal renal artery dilatation for fibromuscular dysplasia with special reference to the acute effects on the renin-angiotensin-aldosterone system and blood pressure.

Twelve hypertensive patients (mean age 46.6 years, range 37-55 years) with fibromuscular dysplasia of the renal artery were treated with percutaneous transluminal renal angioplasty (PTRA) and the effects on the renin-angiotensin-aldosterone system and blood pressure were studied in the acute phase. The technical result of PTRA measured by angiography and reduction of PRA and aldosterone excretion was satisfactory in 11 patients. In spite of this only three patients were cured of their hypertension and two patients were improved at six months follow-up. During PTRA an immediate rise in plasma renin activity was noted in patients without beta-receptor blockade but not in patients treated with beta-receptor blocking agents suggesting a beta-receptor mediated release. This peak in renin release was not accompanied by any rise in systemic blood pressure. The blood pressure response in the acute phase did not show any regular pattern. We conclude that PTRA can serve as a model for studying effects of 'clamping' and 'declamping' of the renal artery in man.

Renal function after urinary diversion. A study of continent caecal reservoir, ileal conduit and colonic conduit.

Total and separate renal function, renal parenchymal thickness and dilatation of the upper urinary tract were studied in 40 patients preoperatively and 24 to 67 months after urinary diversion, using 51Cr-EDTA clearance test, scintillation camera renography and urography. In ten patients a continent caecal reservoir was used for diversion. In the other patients, an ileal or a colonic conduit (15 patients with each method) was used, one ureter being implanted with an anti-reflux method and the other with direct technique. Renal function following urinary diversion showed little or no deterioration in most patients. The functional outcome was not related to the method of diversion or, in the conduit groups, to the mode of ureteral implantation. Serum creatinine tests and urography were not adequate for determining loss of renal function. Radionuclide studies proved to be valuable for assessing renal function after urinary diversion.

Renal Artery Dilation

When patients with renal vascular lesions are not good candidates for surgery, percutaneous transluminal angioplasty (PTA), a new nonsurgical approach, may help. In the hands of a skilled cardiovascular radiologist, this technique is safe, well-tolerated by the patient, and cost-effective. With PTA, the stenosed or occluded renal vessel is mechanically dilated under fluoroscopy using a specially constructed balloon catheter. The catheter, refined by Griintzig in 1976, has a polyvinyl chloride balloon that can be expanded to a predetermined size, thus effectively widening the arterial lumen without overdistending the vessel(1). In current clinical practice, the anatomic lesions that have proved most amenable to treatment with PTA include the following: 1. renal artery stenosis in patients with hypertension or deteriorating renal function; 2. single or multiple focal stenoses of iliac and femoral arteries; 3. coronary artery stenosis or occlusion; 4. subclavian or axillary artery stenosis in patients who have ischemic symptoms.

Use of internal urethrotomy to reverse upper renal tract dilatation in children with neurogenic bladder dysfunction.

Summary— Internal urethrotomy was used to treat 12 patients, aged 1 month to 10 years, with upper renal tract dilatation secondary to a congenital neurogenic bladder. A satisfactory response was achieved in 8, with the best and most consistent results in patients under 4 years of age. It is concluded that internal urethrotomy has a limited but useful role to play in the management of the neurogenic bladder.

Generalized Cardiovascular and Regional Hemodynamic Effects of Meperidine in Conscious Dogs

Changes in both total cardiovascular function and regional hemodynamics associated with large doses of intravenous meperidine were studied in conscious dogs in the absence of other drugs or recent surgery. The animals had previously been surgically prepared by placement of aortic catheters and implantation of chronic indwelling electro-magnetic and Doppler ultrasonic flow probes on the aorta and on mesenteric, renal, and iliac arteries. Meperidine, 2 mg/kg, produced mild renal vascular dilation (10% maximum decreases in resistances and 5% increases in blood flow), but did not alter the resistances and flows in the mesenteric or iliac vascular beds. Meperidine, 6 mg/kg, again resulted in renal dilation (maximum 22% decreases in resistance and 18% increase in blood flow). The iliac vasculature also dilated (maximum 39% decreases in resistance and 40% increases in blood flow). However, the mesenteric vasculature constricted (89% increases in resistance and 40% decreases in blood flow). Following 2 mg/kg of meperidine cardiac output and aortic pressure decreased significantly while total peripheral resistance increased significantly. Heart rate remained unchanged. Following 6 mg/kg of meperidine total peripheral resistance and aortic pressure decreased significantly while heart rate increased. Cardiac output increased during the first part of the observation period then subsequently decreased significantly. It is concluded that in unmedicated dogs meperidine has significant effects on total cardiovascular function and on regional blood flow.

Morphine effects on cardiac output and regional blood flow distribution in conscious dogs.

This study documents the changes in selected regional hemodynamics occurring in response to large doses of intravenous morphine. It was performed in normal conscious dogs. Their cardiovascular systems was unaltered by the presence of other drugs or recent surgery. The animals had been surgically prepared previously by implantation of chronic indwelling electromagnetic and Doppler ultrasonic flow probes on the aorta and the cranial mesenteric, renal and iliac arteries and placement of aortic catheters. Morphine, 1 mg/kg, produced mesenteric vascular dilation (30 per cent maximum decrease in resistance), renal vascular dilation (11 per cent maximum decrease in resistance) and nonsignificant changes in iliac vascular resistance. Morphine, 3 mg/kg, resulted in a similar amount of renal dilation (maximum 12 per cent decrease in resistance) but constricted the mesenteric vasculature (maximum 120 per cent increase in resistance) and the iliac vasculature (68 per cent maximum increase in resistance). These changes were observed despite the lack of sustained major changes in cardiac output, blood pressure, total peripheral resistance, or heart rate. It is therefore concluded that morphine has only minimal effects on systemic hemodynamics, but has significant effects when the alterations it produces in regional hemodynamics are considered. Such alterations may be physiologically significant when perfusion to these individual organs is a concern. The minimal systemic effects of high dose morphine is a phenomenon, for the most part, common to both dogs and humans. Whether similar regional hemodynamics changes as these occur in humans cannot be determined at this time since continuous flow monitoring techniques have, as yet, not been applied to humans.

The axillary approach to percutaneous renal artery dilatation.

The axillary approach to percutaneous transluminal angioplasty of the renal arteries is described. This technique simplifies renal dilatation in patients with severe atherosclerotic disease in the vessels distal to the renal arteries.

Acute renal haemodynamic and renin‐angiotensin system responses to graded renal artery stenosis in the dog.

1. The acute renal haemodynamic and renin-angiotensin system responses to graded renal artery stenosis were studied in chronically instrumented, unanaesthetized dogs. 2. Stenosis was induced over 30 sec by inflation of a cuff around the renal artery to lower distal pressure to 60, 40 or 20 mmHg, with stenosis maintained for 1 hr. This resulted in an immediate fall in renal vascular resistance, but over the next 5--30 min both resistance and renal artery pressure were restored back towards prestenosis values. Only transient increases in systemic arterial blood pressure and plasma renin and angiotensin levels were seen with the two milder stenoses. Despite restoration of renal artery pressure, renal blood flow remained reduced at all grades of stenosis. 3. Pre-treatment with angiotensin I converting enzyme inhibitor or sarosine1, isoleucone8 angiotensin II greatly attenuated or abolished the restoration of renal artery pressure and renal vascular resistance after stenosis, and plasma renin and angiotensin II levels remained high. Renal dilatation was indefinitely maintained, but the normal restoration of resistance and pressure could be simulated by infusing angiotensin II into the renal artery. 4. The effective resistance to blood flow by the stenosis did not remain constant but varied with changes in the renal vascular resistance.

Active surgical management of primary vesicoureteral reflux in adults.

Of 27 adults with primary vesicoureteral reflux, 23 were treated surgically. These patients had suffered from chronic urinary-tract infections with poor response to conservative therapy. Urography revealed inflammatory changes in one or both kidneys in 18 patients, as well as other renal or ureteral deformities. Micturition cystography showed reflux reaching the renal pelvis and dilatation of the pelvis and ureter in 18 patients (28 ureters). An antireflux operation was performed on 32 ureters and in all cases was followed by disappearance of the reflux. No ureteral stricture developed postoperatively. During an observation period averaging more than three years only three patients had postoperative urinary-tract infections. These occurred when a short period of medication was terminated. On the basis of present experience we consider that antireflux surgery is indicated for all adults with vesicoureteral reflux and urinary-tract infections or progressive dilatation of the upper urinary tract.

Furosemide induced release of prostaglandin E to increase renal blood flow.

Levels of PGE in renal venous blood were found to be significantly elevated at the time RBF was increased by furosemide. Following indomethacin, a second dose of furosemide failed to increase RBF and levels of PGE in renal venous blood were not elevated. Levels of PGF and PGA were not affected by furosemide. The increase of PGE in renal venous blood at the time of renal dilation supports the hypothesis that furosemide increases RBF by releasing PGE. An intrarenal action of the released PGE is implied by this mechanism.

Effects of hemorrhage on regional blood flow distribution in dogs and primates.

The effects of hemorrhage on arterial pressure, blood flows, and resistances in the coronary, mesenteric, renal, and iliac beds of healthy, conscious dogs and intact, tranquilized baboons were studied. Mild nonhypotensive hemorrhage (14+/-2 ml/kg) increased heart rate and mesenteric and iliac resistances slightly but significantly, and decreased renal resistance (-13+/-2%). Moderate hypotensive hemorrhage, 26+/-2 ml/kg, reduced mean arterial pressure (-23+/-2 mm Hg) and blood flows to the mesenteric (-56+/-3%), iliac (-58+/-5%), and coronary (-39+/-4%) vascular beds, and increased heart rate (+89+/-9 beats/min) and resistances in the mesenteric (+73+/-15%), iliac (+102+/-19%), and coronary (+27+/-5%) beds. In contrast to the other beds, renal flow rose 11+/-6% above control and renal resistance fell 31+/-2% below control. Renal vasodilatation with hemorrhage was also observed in five baboons. The increases in mesenteric and iliac resistances were blocked almost completely by phentolamine, while the increase in coronary resistance was only partially blocked by phentolamine. The renal dilatation was not blocked by phentolamine, propranolol, atropine, or tripelennamine, but was prevented by indomethacin, suggesting that this dilatation was mediated by a prostaglandin-like compound. Thus the peripheral vascular responses to hemorrhage involve intense vasoconstriction in the mesenteric and iliac beds. In the normal conscious dog and the intact, tranquilized primate, the renal bed does not share in the augmentation of total peripheral resistance with nonhypotensive and moderate hypotensive hemorrhage, but does with more severe hemorrhage. In fact, renal vasodilatation occurs with nonhypotensive or moderate hypotensive hemorrhage, which can be prevented by blockade of prostaglandin synthetase with indomethacin.

Effects of Obstruction of the Mitral Orifice or Distention of the Pulmonary Vein-Atrial Junctions on Renal and Hind-Limb Vascular Resistance in the Dog

This investigation attempted to determine whether stimulation of intrathoracic receptors, including those in the left atrium, is associated with changes in renal vascular resistance. In 19 dogs, the left kidney was perfused at constant pressure and the right hind limb was perfused at constant flow. A partial obstruction of the mitral orifice that increased left atrial pressure by less than 20 cm H 2 O caused tachycardia, hypotension, renal vasodilatation (5% increase in flow), and hind-limb vasoconstriction (10% increase in pressure). A partial obstruction of the orifice that raised left atrial pressure more than 20 cm H 2 O caused tachycardia, hypotension, and more hind-limb vasoconstriction (20% increase in pressure), but renal vascular resistance did not change. After bilateral vagotomy in either the thorax or the neck, partial obstruction of the mitral orifice caused constriction in both the renal and the hind-limb vascular beds. In 10 dogs, localized distention of three pulmonary vein-left atrial junctions caused an increase in heart rate and a small but significant increase in renal blood flow but had no effect on hind-limb vascular resistance. At least a part of the reflex renal dilatation caused by mitral obstruction probably resulted from stimulation of left atrial receptors.

Insuffisance rénale à cause d’une bilharziose urinaire chronique

In more than 50% of the reported cases of urinary bilharziasis, upper urinary dilation was due to a stenosis of the ureters or the loss of their tonicity. Out of 125 patients treated for urinary bilharziasis during the last 17 years in Hopital Necker, Paris, 8 cases presented renal insufficiency (6.4%). Intravenous urography showed bilateral hydronephrosis in 4 cases and unilateral renal dilation of the sole functioning kidney in the remaining cases. Treatment consisted of (1) anthiomaline, cortisone, ureteral catheters (4 cases), (2) colocystoplasty (2 cases), (3) uretero ileo cystoplasty (2 cases) allowing normalization of renal function in 7 cases. Seven surviving patients were followed for an average period of 19 months. One patient died from septicemia on the fourth day after retrograde pyelogram. Prognosis of the disease depends on the degree of renal dilation. Patients should be operated upon before ureteral tonicity and renal function become severely impaired.