Hydronephrosis

Obstructive nephropathy in the pig. Possible roles for insulin-like growth factor I

Kidney growth was investigated in 30-kg pigs after 72 h of unilateral ureteral obstruction. The data were compared to control kidneys from normal non-operated pigs at same weight. Kidney wet weight was determined. Cortex and medulla were separated, and from both regions RNA, DNA, protein and kidney tissue insulin-like growth factor I was determined. Unilateral obstruction caused a doubling of the wet hydronephrotic kidney weight and an ipsilateral 76% increase in total kidney protein content. RNA increased by 45% in the cortex and 76% in the medulla. Kidney protein in the contralateral cortex increased by 23% and RNA by 42%. In the hydronephrotic kidney DNA was reduced by 13% in the cortex and by 21% in the medulla. Contralaterally, DNA was the same as in the controls. Mean kidney insulin-like growth factor I increased sevenfold in the ipsilateral medulla but in the cortex it was the same as in the controls. Serum insulin-like growth factor I concentration was 1.7 +/- 1.1 micrograms/l in the hydronephrotic animals and 1.2 +/- 0.8 micrograms/l in controls. At this stage of obstruction, our data demonstrate (1) hydronephrotic growth that is most probably hyperplastic in the medulla, associated with an increase in medullary insulin-like growth factor I, (2) hyperplastic growth in the cortex, and (3) contralateral kidney growth that is mainly hypertrophic after 72 h of contralateral ureteral obstruction.

Urographic Appearances in Renal Failure Due to Intraluminal Ureteric Obstruction

With reference to a series of 13 patients, the urographic signs seen in the conditions of acute, post-acute, chronic and acute-on-chronic obstruction are described. These are seen in a relatively pure form in patients with renal failure due to ureteric calculi. Patients in renal failure with acute, post-acute, or acute-on-chronic obstruction are anuric or oliguric; patients with chronic obstruction due to bilateral ureteric stones are polyuric. After removal of the stones the urine output returns to normal in cases of acute obstruction, is reduced in chronic obstruction but is increased in post-acute obstruction. A further case is described which illustrates the importance of recognizing post-acute obstruction unaccompanied by pain: The kidney may be completely obstructed and so be destroyed. The different types of obstruction are recognized by considering the nephrographic and pyelographic signs together with the presence or absence of pain.

The urographic signs of acute on chronic obstruction of the kidney

The signs of acute obstruction of the kidney and of chronic obstruction are well recognised and the combination of these signs enables a group of patients with acute-on-chronic obstruction to be recognised. The signs of acute obstruction are entirely nephrographic. They are manifested by an increasingly dense nephrogram, which may become striated, followed by an anatomically normal pyelogram. The signs of chronic obstruction are both pyelographic and nephrographic. The pyelographic signs are a dilated pelvicalyceal system. The nephrographic signs are a normal or low density nephrogram. Crescents may appear; these are due to opacification of the distorted medulla which retains its ability to concentrate the urine. In acute-on-chronic obstruction the signs of both conditions are present. Thus there is an increasingly dense nephrogram with a negative pyelogram. Crescents may appear. There is a slow flow in the dilated pelvicalyceal system.

Radiograph measurements and contralateral renal size in primary pelvic hydronephrosis

Renal size was estimated from the radiographs in 47 cases of primary pelvic hydronephrosis. The area of functioning renal tissue of the side opposite to the disease was greater in patients with severe hydronephrosis treated by pheloplasty, compared with those with moderate disease (P less than 0.05). This suggests that compensatory hypertrophy had occurred in the contralateral kidney. This finding did not appear to affect the outcome of pyeloplasty. It is suggested that the finding of compensatory hypertrophy in the kidney opposite to a severe hydronephrosis is not a contra-indication to conservative surgery.

Pyonephrosis

The clinical and radiological features of pyonephrosis are reviewed, based on a consecutive series of 40 cases. There were 32 female and eight male patients, with a peak incidence in the 50-59 year age group. In 63% of cases the right kidney was involved. Almost all patients complained of loin pain and 48% had lower urinary tract symptoms. In 58% of cases a renal mass was palpable. An anaemia, pyuria and elevated blood sedimentation rate were usual. Plain films of the abdomen revealed enlargement of the outline of the involved kidney in 75%, ipsilateral absence of the psoas shadow in 63% and urinary tract calculi in 60%. At high-dose excretion urography a nephrogram was obtained in 58% of cases and a pyelogram produced in 34%. No single clinical or radiological entity emerged, there being an unbroken spectrum of disease ranging from infected hydronephrosis to xanthogranulomatous pyelonephritis. There is an increasing incidence of calculi, loss of the renal and psoas outlines and reduced renal function with increasing chronicity of disease. High-dose excretion urography is the investigation of choice since not only may the diagnosis be established but also there precise pathological state of the involved kidney. Further radiological investigation is infrequently required.

Transitional cell carcinoma of the kidney

Transitional cell carcinoma is an uncommon disease of the renal pelvis, the diagnosis of which depends largely upon radiological investigation. Thirty-eight such tumours in 37 patients have been reviewed to establish the examination of choice. High-dose excretion urography, tailored to the presenting problems, is the primary investigation and the results fall into five main groups. Each presents different differential diagnostic problems. Discrete filling defects within the pyelogram (group I) may be overlooked, but, when seen, can be diagnosed on urography alone. Filling defects with dilated calyces (group II) are easily seen and readily diagnosed. Calyceal obliteration (group III) presents more difficulty in diagnosis and may require retrograde pyelography and selective renal angiography. Hydronephrosis with renal enlargement (group IV) is easily confused with uncomplicated primary pelvic hydronephrosis and will usually require antegrade pyelography for diagnosis. Reduced function without renal enlargement (group V) cannot be diagnosed on excretion urography and requires both retrograde pyeloureterography and selective renal angiography.

Renal cyst puncture: a non-diagnostic procedure in the infant

A case of metastatic Wilms tumor in a newborn is presented. Cyst puncture was included in the preoperative evaluation and the merits of this procedure in infants are questioned. The differential diagnosis of intrarenal masses in the neonate is discussed.

The layered pyelogram in hydronephrosis

Fifty patients were studied with erect films at excretory urography. Twenty-eight had hydronephrosis, bilateral in two cases; a total of 30 hydronephrotic kidneys were therefore investigated. Thin layers of contrast medium were shown in the dilated calyces in 29 of the 30 kidneys. The layered pyelogram is a simple, sensitive urographic sign of hydronephrosis, which may be demonstrated in the absence of a discernible pyelogram in the routine film or tomograph. The basis of layering has been investigated by simple experiments. Since the layered pyelogram may be the only urographic evidence of a poorly excreting hydronephrotic kidney, erect films should be routinely used at excretory urography when this condition is to be diagnosed or excluded.