Pediatric Radiology

Pediat. Radiol. 6, 168-171 (1977)

9 by Springer-Veflag1977

Application of Aortography and Ultrasound in Evaluation of Renal Agenesis F. B. Toomeyl, P. Fritzsche, E. Carlsen, H. Caggiano, N. Vyhmeister, and V. Kullman Departments of Radiology and Pediatrics, Loma Linda University Medical Center, Loma Linda, California, USA

Abstract. Ultrasound followed by aortography, if necessary, has been a useful approach in the diagnosis of suspected renal agenesis.

Key words: Potter's Syndrome - Ultrasound Aortography Previous reports have alerted the clinician to the diagnosis of Potter's Syndrome on the basis of the facial appearance and pulmonary hypoplasia [2, 3, 4, 5]. This paper reports seven infants who had renal agenesis. In four infants, the diagnosis was confirmed utilizing aortography; three of these also were studied with ultrasound.

Report of Cases Seven infants having Potter's Syndrome were studied, including autopsy examination at Loma Linda University Medical Center from 1973 to 1975. Birth weight varied from 1600 to 2890 grams. Duration of survival ranged between three hours and eight days. Four had Potter facies and the other three had low set ears. Limb anomalies were common, including club feet. All had respiratory distress at birth and five had pneumothorax. All infants had hypoplastic lungs. One infant had an imperforate anus and absent penis. In five cases, the bladder was rudimentary and the urethra not patent. In two males, no prostate was noted and the testes were high in the abdomen, while three males had normal prostate, testes and epididymes. Of the two female infants, one had agenesis of the uterus, oviducts, ovaries and vagina and the other had normal ovaries and hypoplastic uterus. All cases showed absent kidneys and renal arteries. The adrenals of all seven were flat, oval and normal in weight (3 to 5 grams each).

1 Associate Professor of Radiology

Roentgen Findings Aortography was performed using the Judkins' technique [1]. The examination was obtained without moving the patient from the Intensive Care Unit and without sedation. An umbilical arterial catheter tip was placed at the thoracolumbar junction. Three cc's of Renografin 60 was injected through the umbilical arterial catheter and a film obtained at the end of the rapid injection. An immediate follow-up abdominal film was obtained, to determine the presence or absence ofa nephrogram. The normal newborn renal arteries arise opposite the first lumbar vertebra (Fig. 1). The renal arteries may be multiple and small or they may be obscured by overlying vessels, usually branches of the superior mesenteric or lumbar arteries. Renal arteries may be confused with large arteries supplying the adrenal glands. Renal artery absence can usually be determined when no vessel arises from the anticipated site of origin in the aorta, in spite of filling the usual abdominal aortic branches (Fig. 2). In questionable cases of renal artery presence, the radiographs must be scrutinized carefully for an arcade of intrarenal arteries and a nephrogram. Renal disease such as multicystic kidney or renal vein thrombosis may delay filling of the intrarenal arcade, visualized on the delayed film. Grey scale ultrasound can be used to demonstrate renal structure. The technique is noninvasive and requires essentially no preparation. A warm, quiet baby is more conducive to a good study, but sedation is unnecessary. The technique is best performed by using a relatively high frequency near-focused transducer (3.5 MHz or 5 MHz). Single pass scanning, with

F. B. Toomey et al.: Potter's Syndrome

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Fig. 1. Normal newborn infant aortogram. The renal arteries arise opposite the second lumbar vertebra. The caliber of the renal arteries is approximately two times that of the lumbar arteries. There is incidental pulmonary artery filling from a patent ductus arteriosus

Fig. 3. Ultrasound longitudinal section on normal newborn infant. Note normal renal, (open arrow) and adrenal echoes, (curved arrows) against the posterior abdominal wall and beneath the liver

Fig. 2. Aortogram on patient with renal agenesis. Note absent renal arteries with visualization of the hepatic, splenic, and lumbar vessels. The aorta does not show a decrease in caliber distal to the anticipated site of the renal arteries

Fig. 4. Ultrasound longitudinal section on infant with renal agenesis. No renal echo seen, but adrenal echo noted, (curved arrows)

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Fig. 5. Autopsy specimen of infant with renal agenesis. The adrenal glands are large, fiat, oval discs on the posterior wall of the abdominal cavity. No renal arteries arise from the aorta. One lumbar artery is visible. The right adrenal vein courses inferiorly into the vena cava

Fig. 6. Ultrasound longitudinal section on infant showing a unilateral, small mass with irregular margins and absence of normal parenchymal echoes. This proved to be a small dysplastic, kidney, (arrows)

F.B. Toomey et al.: Potter's Syndrome

appropriate time compensated gain will provide a readable scan even with some patient motion. To assure adequate evaluation of the kidney bed, views from the right and left decubitus positions should also be performed. Frequently, the right kidney bed may be studied with anteroposterior technique, using the liver as a window. If the examination must be performed at the bedside, a portable real time scanner with high frequency probes can be utilized. The kidneys are oval, well-marginated masses, which produce on ultrasound, a characteristic pattern (Fig. 3). The renal collecting system produces a bright central echo. The kidney cortex reveals a softer, finer echo pattern than the liver. It is important not to confuse the enlarged adrenals of the neonate for kidneys. W h e n there is no kidney tissue present, adrenal glands do not have a normal triangular cap shape [3]. In one patient with renal agenesis, we misinterpreted the adrenal echo for a kidney echo, (Fig. 4). In this sonogram, there is a mass with a partial, wellmarginated border. Other sections confirm the presence of a cylindrical structure containing bright hilar echoes. Typical stronger and coarser liver echoes surround the mass. A portion of the diaphragm can be seen in the left lower corner. We interpreted this density as the right kidney. However, the specimen, (Fig. 5) on this patient reveals absent kidneys and normal large adrenals.

Fig. 7. Aortogram showing displaced renal arteries, (arrows). Anuric newborn with ureteropelvic obstruction and bilateral urinomas, in addition to anterior urethral valve

F. B. Toomey et al.: Potter's Syndrome

The newborn adrenal is approximately ninety percent cortex, and regresses to its more usual size within a few days. In the absence of kidneys, adrenal shape changes to a more renal type appearance. For best confirmation of the presence of kidneys, both adrenal and kidney echoes should be identified. The presence of kidneys is easier to confirm than their absence. Potter-like facies and pulmonary hypoplasia may be encountered without bilateral renal agenesis. In some instances, one kidney is missing and the other hypoplastic and multicystic. We encountered one such infant who had peculiar facies, anuria, and pulmonary hypoplasia. Aortography and ultrasound (Fig. 6) confirmed the presence of one small renal artery and a small mass on the same side. On ultrasound, the margins appeared irregular and there was absence of normal parenchymal internal echoes. This proved to be a small multicystic kidney. More importantly, some anuric conditions are compatible with longevity. In one anuric infant, there were bilateral abdominal masses. Echoes showed large cystic masses, and there were displaced, normal-sized renal arteries on aortography (Fig. 7). This infant proved to have an anterior urethral valve, bilateral ureteropelvic obstruction with secondary polycystic disease and also, large urinomas. After surgical treatment, renal function improved.

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renal abnormalities may be differentiated from renal agenesis. Limitation of expensive medical therapy in an inevitably lethal disease is expedited. Acknowledgement. We wish to thank Carl Jansen, M. D. and Frederick Orr, M. D. of San Bernardino County Hospital, San Bemardino, California, for contribution of their case.

References 1. Judkins, M. P., Dotter, C. T.: Angiographic Evaluation of anuria in the newborn. Am. J. Roentgenol. Radium Ther. Nucl. Med. 97, 239 (1966) 2. Leonidas, J. C., Fellows, R. A., Hall, R. T., Rhodes, P. G., Beatty, E. C.: Value of chest radiography in the diagnosis of Potter's syndrome at birth. Am. J. Roentgenol. Radium Ther. Nucl. Med. 123, 716 (1975) 3. Potter, E. L., Craig, J. M.: Pathology of the Fetus and infant. Chicago: Year Book Publishers 1975 4. Renert, W. A., Berdon, W. E., Baker, D. H., Rose, J. S.: Obstructive urologic malformations of fetus and infantrelation to neonatal pneumomediastinum and pneumothorax: (air-block). Radiology 105, 97 (1972) 5. Stern, L., Fletcher, B. D., Dunbar, J. S., Levant, M. N., Faucett, J. S.: Pneumothorx and pneumomediastinum associated with renal malformations in newborn infants. Am. J. Roentgenol. Radium Ther. Nucl. Med. 116, 785 (1972)

Date of final acceptance: August 2, 1977

Summary Ultrasound and/or aortography are useful techniques for documenting the existence of kidneys in anuric newborn infants. Surgically correctable

F. B. Toomey, M.D. Department of Radiology Loma Linda University Medical Center Loma Linda, CA 92354 USA

Application of aortography and ultrasound in evaluation of renal agenesis.

Pediatric Radiology Pediat. Radiol. 6, 168-171 (1977) 9 by Springer-Veflag1977 Application of Aortography and Ultrasound in Evaluation of Renal Age...
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