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Renovascular Hypertension in an Infant with Segmental Renal Artery Stenosis and Hypoplasia of the Abdominal Aorta
0022-5347 /83/1301-0127$02.00/0 Vol. 130, July Printed in U.S.A.
THE JOURNAL OF UROLOGY
Copyright© 1983 by The Williams & Wilkins Co.
RENOVASCULAR HYPERTENSION IN AN INFANT WITH SEGMENTAL RENAL ARTERY STENOSIS AND HYPOPLASIA OF THE ABDOMINAL AORTA WATSON C. ARNOLD,* JORGE F. JIMENEZ, PHILLIP SMITH, J.B. NORTON AND JOHN F. REDMAN From the Departments of Pediatrics, Pathology, Radiology and Urology, University of Arkansas College of Medicine and Arkansas Children's Hospital, Little Rock, Arkansas
ABSTRACT
Hypoplasia of the abdominal aorta is a rare cause of renovascular hypertension. Arteriographic studies of the renal vasculature are presented from an infant with hypoplasia of the abdominal aorta and segmental renal artery stenosis. The renovascular hypertension was cured by partial nephrectomy. There was no difference in the parenchymal histology in the tissue from the congenitally ischemic lower pole of the kidney and the vascularized upper pole. In this unique case with decreased renal blood flow during fetal development there was no evidence that parenchymal ischemia can cause renal parenchymal hypoplasia. Vascular causes account for 90 per cent of the hypertension in children, with renal artery stenosis causing 10 to 15 per cent of the cases. 1 Although coarctation of the aorta is the cause of hypertension in only 2 per cent of all children it may be the most common etiology of hypertension in infancy. 2 Hypoplasia of the abdominal aorta is a rare congenital defect, especially when associated with renal artery stenosis and renovascular hypertension. 3- 6 Since few reports have discussed the renal parenchymal findings in congenital renal artery stenosis the presence of renal artery stenosis, especially with a segmental artery stenosis, provides an opportunity to determine if poor vascularization of the kidneys during fetal life can result in renal parenchymal hypoplasia. 7 We studied with arteriography a patient with congenital segmental renal artery stenosis associated with hypoplasia of the abdominal aorta. A renal biopsy was performed at the time of partial nephrectomy. Additional arteriograms were done 12 months postoperatively. CASE REPORT
R. S., a 4-month-old infant, was seen initially with acute otitis media, pneumonia and dehydration. Initially, the blood pressure measured with a proper-sized cuff in the upper extremities was 80/50 mm. Hg but after volume expansion the blood pressure increased to 220/120 mm. Hg. Blood pressure in the legs was 120/50. After receiving 1 mg./kg. intravenous hydralazine and 2.5 mg./kg. diazoxide, the pressure decreased to 110/ 80mm. Hg. Physical examination was normal except for decreased femoral pulses. There were no cardiac or abdominal murmurs. Generalized cardiomegaly was apparent on radiographic examination and electrocardiographic evidence of left ventricular hypertrophy was noted. An echocardiogram showed hypertrophy of the left ventricle and ventricular septum but was otherwise normal. Blood urea nitrogen was 8 mg. per cent, creatinine was 0.4 mg. per cent and electrolytes were normal. Clinical diagnosis was coarctation of the aorta. Arteriograms during cardiac catheterization showed a coarctation of the abdominal aorta with aortic hypoplasia below the renal arteries and a significant stenosis or hypoplasia of the inferior mesenteric artery (fig. 1). The artery supplying the left Accepted for publication November 12, 1982. * Requests for reprints: Division of Pediatric Nephrology, Arkansas Children's Hospital, 804 Wolfe St., Little Rock, Arkansas 72201.
kidney was normal and arose above the hypoplastic segment of the aorta. The right kidney was supplied by 2 renal arteries. The artery to the upper pole of the right kidney arose from above the hypoplastic segment of the aorta and filled normally. The lower pole of the right kidney was smaller and filled more slowly than the upper pole. Plasma renin concentration from the left renal vein was 84.9 ng./ml. per hour. The segmental renal vein renin from the right upper renal vein was 91 ng./ml. per hour and from the right lower renal vein it was 118 ng./ml. per hour. The inferior vena cava had a renin level of 83 ng./ml. per hour. The blood pressure was controlled with 5 mg. propranolol every 6 hours, 0.7 mg. minoxidil twice daily, 10 mg. hydralazine 3 times daily and 5 mg. furosemide twice daily. After a month of oral therapy significant hypertrichosis developed, which became a major concern of the parents. Because of the difficulty of medical management without minoxidil surgical intervention was planned. At operation the artery to the lower pole of the right kidney arose from the hypoplastic portion of the aorta and was stenotic 0.5 cm. from its point of origin. With cross-clamping the lower pole of the right kidney became cyanotic and a tangential resection of the cyanotic portion of the kidney allowed for removal of the parenchyma supplied by that vessel. A wedge biopsy of the upper pole of the right kidney also was accomplished. Microscopically, the upper pole sample showed normal glomeruli, tubules, interstitium and vasculature. In the lower pole the glomeruli appeared relatively smaller with no evidence of proliferative, membranous or fibrous changes (fig. 2). There were a few isolated glomeruli with features suggestive of fetal glomeruli. The juxtaglomerular apparatus was not prominent with routine staining of the kidney tissue. Special stains were not performed on the juxtaglomerular tissue. A few tubules showed luminal dilatation and contained proteinaceous material. There was no evidence of fibrous proliferation or unusual cellular infiltrate in the interstitium. The interlobar arteries were prominent with thickened muscular walls and relative narrowing of the lumen. There was no evidence of fibromuscular dysplasia. After surgical removal of the poorly vascularized portion of the kidney the blood pressure returned to normal and has remained normal without antihypertensive medications for 6 months. The plasma renin level was 2.4 ng./ml. per hour and the patient is growing normally with normal activity tolerance.
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FIG. 1. A, bolus aortogram reveals superior mesenteric artery (large arrow) larger than aorta. Right lower pole renal artery (small arrow) is occluded at its origin and fills through collateral vessels. B, origin of left renal artery and right upper pole renal artery are above hypoplastic segment. Right lower pole branch (small arrow) faintly fills in retrograde manner. Inferior mesenteric artery (large arrows) is stenotic at its origin within segment of coarctation.
small segmental renal arteries, renal parenchymal hypoplasia and hypertension. 10- 12 Although some authors have conjectured that the lesions in Ask-Upmark kidneys may represent developmental failure of the renal parenchyma from poor prenatal vascularization, 11' 13 Arant and associates14 recently presented convincing evidence that many children diagnosed with segmental hypoplasia have an acquired lesion secondary to vesicoureteral reflux and pyelonephritis. The morphological fmdings in segmental hypoplasia include renal dysplasia, interstitial fibrosis, tubular atrophy and thyroidization of the renal tubules in a segmental distribution. 15 Only rarely have these renal parenchymal findings been reported in children with renal artery stenosis and never in infancy.4· 7 In our patient we had the unique opportunity to determine the effect of congenital segmental renal artery stenosis on the development and maturation of the kidney. Although minor abnormalities were identified we found that the histopathologic conditions of both poles of the affected kidney were essentially normal. The abdominal aortic hypoplasia and segmental renal artery stenosis to the lower pole had most likely existed since early in gestation and perfusion was decreased during development. However, there was minimal evidence of dysplastic-hypoplastic renal parenchymal changes. Despite elevated renin values, there was no juxtaglomerular hyperplasia in this infant, unlike other reports of older children. 7 These findings indicate that during gestation poor renal vascularization alone does not lead to the development of hypoplastic-dysplastic abnormalities of the renal parenchyma. REFERENCES
Fm. 2. Right lower pole partial nephrectomy. A, overview of renal parenchyma without significant pathologic condition. H & E, reduced from X45. B, corticomedullary junction exhibits prominent vasculature and adjacent lymphatics with dilatation (asterisks). H & E, reduced from XllO. C, interlobar arteries with thickened muscular wall, relative narrowing of lumen and prominent endothelial lining (arrows). Note portion of fetal-like glomerulus. H & E, reduced from X500.
DISCUSSION
This case demonstrates several unique aspects in the evolution of renovascular hypertension. This is one of the few reports of abdominal aortic hypoplasia and hypertension diagnosed during infancy. To our knowledge, this is the only case in which renal tissue was obtained from both poles of an affected kidney. From these data we were able to compare the effect of decreased renal blood flow from early gestation on renal parenchymal development of the kidney. The differential diagnoses of hypertension in an infant include a coarctation of the thoracic aorta, 2 renal artery stenosis,4' 7 hypoplastic-dysplastic kidneys, 8 infantile polycystic kidneys1 and coarctation of the abdominal aorta. 3' 5, 6 Of the hypertensive children of all ages 12 per cent have associated renal artery stenosis, which is caused most commonly by fibromuscular dysplasia. 1' 9 ' 10 Hypoplastic-dysplastic kidneys show a spectrum of lesions, including cysts and disorganization of the renal parenchyma with immature glomeruli and tubular abnormalities. Dysplastic kidneys usually are associated with other congenital abnormalities of the urinary tract. 8 Children with segmental hypoplasia of the kidney (Ask-Upmark kidneys) present at a later age with
1. Londe, S.: Causes of hypertension in the young. Ped. Clin. N. Amer., 25: 55, 1978. 2. Nadas, A. S. and Fyler, D. C.: Pediatric Cardiology, 3rd ed. Philadelphia: W. B. Saunders Co., p. 452, 1972. 3. Fisher, E. R. and Corcoran, A. C.: Congenital coarctation of abdominal aorta with resultant renal hypertension. Arch. Intern. Med., 89: 943, 1952. 4. Lambeth, C. B., Derrick, J. R. and Hansen, A. E.: Stenosis of a branch of the renal artery causing hypertension in a child, including a complication of translumbar renal arteriography. Pediatrics, 26: 822, 1960. 5. Bjork, V. 0. and Intonti, F.: Coarctation of abdominal aorta with right renal artery stenosis. Ann. Surg., 160: 54, 1964. 6. De Bakey, M. E., Garrett, H. E., Howell, J. R. and Morris, G. C., Jr.: Coarctation of the abdominal aorta with renal arterial stenosis: surgical considerations. Ann. Surg., 165: 830, 1967. 7. Bennett, S. P., Levine, L. S., Siegal, E. J., Levy, J.E., Susin, M., Peterson, R. E. and New, M. I.: Juvenile hypertension caused by overproduction ofrenin within a renal segment. J. Ped., 84: 689, 1974. 8. Risdon, R. A., Young, L. W. and Chrispin, A. R.: Renal hypoplasia and dysplasia: a radiological and pathological correlation. Ped. Rad., 3: 213, 1975. 9. Fry, W. J., Ernst, C. B., Stanley, J. C. and Brink, B.: Renovascular hypertension in the pediatric patient. Arch. Surg., 107: 692, 1973. 10. Stoney, R. J., Cooke, P.A. and String, S. T.: Surgical treatment of renovascular hypertension in children. J. Ped. Surg., 10: 631, 1975. 11. Blyth, H. and Ockenden, B. G.: Polycystic disease of kidney and liver presenting in childhood. J. Med. Genet., 8: 257, 1971. 12. Himmelfarb, E., Rabinowitz, J. G., Parvey, L., Gammill, S. and Arant, B.: The Ask-Upmark kidney. Roentgenographic and pathological features. Amer. J. Dis. Child., 129: 1440, 1975. 13. Royer, P., Habib, R., Broyer, M. and Nouaille, Y.: Segmental hypoplasia of the kidney in children. Adv. Nephrol., 1: 145, 1971. 14. Arant, B. S., Jr., Sotelo-Avila, C. and Berstein, J.: Segmental "hypoplasia" of the kidney (Ask-Upmark). J. Ped., 95: 931, 1979. 15. Ljunggvist, A. and Lagergren, C.: The Ask-Upmark kidney. A congenital renal anomaly studied by micro-angiography and histology. Acta Path. Microbiol. Scand., 56: 277, 1962.
THE JOURNAL OF UROLOGY
Copyright© 1983 by The Williams & Wilkins Co.
RENOVASCULAR HYPERTENSION IN AN INFANT WITH SEGMENTAL RENAL ARTERY STENOSIS AND HYPOPLASIA OF THE ABDOMINAL AORTA WATSON C. ARNOLD,* JORGE F. JIMENEZ, PHILLIP SMITH, J.B. NORTON AND JOHN F. REDMAN From the Departments of Pediatrics, Pathology, Radiology and Urology, University of Arkansas College of Medicine and Arkansas Children's Hospital, Little Rock, Arkansas
ABSTRACT
Hypoplasia of the abdominal aorta is a rare cause of renovascular hypertension. Arteriographic studies of the renal vasculature are presented from an infant with hypoplasia of the abdominal aorta and segmental renal artery stenosis. The renovascular hypertension was cured by partial nephrectomy. There was no difference in the parenchymal histology in the tissue from the congenitally ischemic lower pole of the kidney and the vascularized upper pole. In this unique case with decreased renal blood flow during fetal development there was no evidence that parenchymal ischemia can cause renal parenchymal hypoplasia. Vascular causes account for 90 per cent of the hypertension in children, with renal artery stenosis causing 10 to 15 per cent of the cases. 1 Although coarctation of the aorta is the cause of hypertension in only 2 per cent of all children it may be the most common etiology of hypertension in infancy. 2 Hypoplasia of the abdominal aorta is a rare congenital defect, especially when associated with renal artery stenosis and renovascular hypertension. 3- 6 Since few reports have discussed the renal parenchymal findings in congenital renal artery stenosis the presence of renal artery stenosis, especially with a segmental artery stenosis, provides an opportunity to determine if poor vascularization of the kidneys during fetal life can result in renal parenchymal hypoplasia. 7 We studied with arteriography a patient with congenital segmental renal artery stenosis associated with hypoplasia of the abdominal aorta. A renal biopsy was performed at the time of partial nephrectomy. Additional arteriograms were done 12 months postoperatively. CASE REPORT
R. S., a 4-month-old infant, was seen initially with acute otitis media, pneumonia and dehydration. Initially, the blood pressure measured with a proper-sized cuff in the upper extremities was 80/50 mm. Hg but after volume expansion the blood pressure increased to 220/120 mm. Hg. Blood pressure in the legs was 120/50. After receiving 1 mg./kg. intravenous hydralazine and 2.5 mg./kg. diazoxide, the pressure decreased to 110/ 80mm. Hg. Physical examination was normal except for decreased femoral pulses. There were no cardiac or abdominal murmurs. Generalized cardiomegaly was apparent on radiographic examination and electrocardiographic evidence of left ventricular hypertrophy was noted. An echocardiogram showed hypertrophy of the left ventricle and ventricular septum but was otherwise normal. Blood urea nitrogen was 8 mg. per cent, creatinine was 0.4 mg. per cent and electrolytes were normal. Clinical diagnosis was coarctation of the aorta. Arteriograms during cardiac catheterization showed a coarctation of the abdominal aorta with aortic hypoplasia below the renal arteries and a significant stenosis or hypoplasia of the inferior mesenteric artery (fig. 1). The artery supplying the left Accepted for publication November 12, 1982. * Requests for reprints: Division of Pediatric Nephrology, Arkansas Children's Hospital, 804 Wolfe St., Little Rock, Arkansas 72201.
kidney was normal and arose above the hypoplastic segment of the aorta. The right kidney was supplied by 2 renal arteries. The artery to the upper pole of the right kidney arose from above the hypoplastic segment of the aorta and filled normally. The lower pole of the right kidney was smaller and filled more slowly than the upper pole. Plasma renin concentration from the left renal vein was 84.9 ng./ml. per hour. The segmental renal vein renin from the right upper renal vein was 91 ng./ml. per hour and from the right lower renal vein it was 118 ng./ml. per hour. The inferior vena cava had a renin level of 83 ng./ml. per hour. The blood pressure was controlled with 5 mg. propranolol every 6 hours, 0.7 mg. minoxidil twice daily, 10 mg. hydralazine 3 times daily and 5 mg. furosemide twice daily. After a month of oral therapy significant hypertrichosis developed, which became a major concern of the parents. Because of the difficulty of medical management without minoxidil surgical intervention was planned. At operation the artery to the lower pole of the right kidney arose from the hypoplastic portion of the aorta and was stenotic 0.5 cm. from its point of origin. With cross-clamping the lower pole of the right kidney became cyanotic and a tangential resection of the cyanotic portion of the kidney allowed for removal of the parenchyma supplied by that vessel. A wedge biopsy of the upper pole of the right kidney also was accomplished. Microscopically, the upper pole sample showed normal glomeruli, tubules, interstitium and vasculature. In the lower pole the glomeruli appeared relatively smaller with no evidence of proliferative, membranous or fibrous changes (fig. 2). There were a few isolated glomeruli with features suggestive of fetal glomeruli. The juxtaglomerular apparatus was not prominent with routine staining of the kidney tissue. Special stains were not performed on the juxtaglomerular tissue. A few tubules showed luminal dilatation and contained proteinaceous material. There was no evidence of fibrous proliferation or unusual cellular infiltrate in the interstitium. The interlobar arteries were prominent with thickened muscular walls and relative narrowing of the lumen. There was no evidence of fibromuscular dysplasia. After surgical removal of the poorly vascularized portion of the kidney the blood pressure returned to normal and has remained normal without antihypertensive medications for 6 months. The plasma renin level was 2.4 ng./ml. per hour and the patient is growing normally with normal activity tolerance.
127
128
ARNOLD AND ASSOCIATES
FIG. 1. A, bolus aortogram reveals superior mesenteric artery (large arrow) larger than aorta. Right lower pole renal artery (small arrow) is occluded at its origin and fills through collateral vessels. B, origin of left renal artery and right upper pole renal artery are above hypoplastic segment. Right lower pole branch (small arrow) faintly fills in retrograde manner. Inferior mesenteric artery (large arrows) is stenotic at its origin within segment of coarctation.
small segmental renal arteries, renal parenchymal hypoplasia and hypertension. 10- 12 Although some authors have conjectured that the lesions in Ask-Upmark kidneys may represent developmental failure of the renal parenchyma from poor prenatal vascularization, 11' 13 Arant and associates14 recently presented convincing evidence that many children diagnosed with segmental hypoplasia have an acquired lesion secondary to vesicoureteral reflux and pyelonephritis. The morphological fmdings in segmental hypoplasia include renal dysplasia, interstitial fibrosis, tubular atrophy and thyroidization of the renal tubules in a segmental distribution. 15 Only rarely have these renal parenchymal findings been reported in children with renal artery stenosis and never in infancy.4· 7 In our patient we had the unique opportunity to determine the effect of congenital segmental renal artery stenosis on the development and maturation of the kidney. Although minor abnormalities were identified we found that the histopathologic conditions of both poles of the affected kidney were essentially normal. The abdominal aortic hypoplasia and segmental renal artery stenosis to the lower pole had most likely existed since early in gestation and perfusion was decreased during development. However, there was minimal evidence of dysplastic-hypoplastic renal parenchymal changes. Despite elevated renin values, there was no juxtaglomerular hyperplasia in this infant, unlike other reports of older children. 7 These findings indicate that during gestation poor renal vascularization alone does not lead to the development of hypoplastic-dysplastic abnormalities of the renal parenchyma. REFERENCES
Fm. 2. Right lower pole partial nephrectomy. A, overview of renal parenchyma without significant pathologic condition. H & E, reduced from X45. B, corticomedullary junction exhibits prominent vasculature and adjacent lymphatics with dilatation (asterisks). H & E, reduced from XllO. C, interlobar arteries with thickened muscular wall, relative narrowing of lumen and prominent endothelial lining (arrows). Note portion of fetal-like glomerulus. H & E, reduced from X500.
DISCUSSION
This case demonstrates several unique aspects in the evolution of renovascular hypertension. This is one of the few reports of abdominal aortic hypoplasia and hypertension diagnosed during infancy. To our knowledge, this is the only case in which renal tissue was obtained from both poles of an affected kidney. From these data we were able to compare the effect of decreased renal blood flow from early gestation on renal parenchymal development of the kidney. The differential diagnoses of hypertension in an infant include a coarctation of the thoracic aorta, 2 renal artery stenosis,4' 7 hypoplastic-dysplastic kidneys, 8 infantile polycystic kidneys1 and coarctation of the abdominal aorta. 3' 5, 6 Of the hypertensive children of all ages 12 per cent have associated renal artery stenosis, which is caused most commonly by fibromuscular dysplasia. 1' 9 ' 10 Hypoplastic-dysplastic kidneys show a spectrum of lesions, including cysts and disorganization of the renal parenchyma with immature glomeruli and tubular abnormalities. Dysplastic kidneys usually are associated with other congenital abnormalities of the urinary tract. 8 Children with segmental hypoplasia of the kidney (Ask-Upmark kidneys) present at a later age with
1. Londe, S.: Causes of hypertension in the young. Ped. Clin. N. Amer., 25: 55, 1978. 2. Nadas, A. S. and Fyler, D. C.: Pediatric Cardiology, 3rd ed. Philadelphia: W. B. Saunders Co., p. 452, 1972. 3. Fisher, E. R. and Corcoran, A. C.: Congenital coarctation of abdominal aorta with resultant renal hypertension. Arch. Intern. Med., 89: 943, 1952. 4. Lambeth, C. B., Derrick, J. R. and Hansen, A. E.: Stenosis of a branch of the renal artery causing hypertension in a child, including a complication of translumbar renal arteriography. Pediatrics, 26: 822, 1960. 5. Bjork, V. 0. and Intonti, F.: Coarctation of abdominal aorta with right renal artery stenosis. Ann. Surg., 160: 54, 1964. 6. De Bakey, M. E., Garrett, H. E., Howell, J. R. and Morris, G. C., Jr.: Coarctation of the abdominal aorta with renal arterial stenosis: surgical considerations. Ann. Surg., 165: 830, 1967. 7. Bennett, S. P., Levine, L. S., Siegal, E. J., Levy, J.E., Susin, M., Peterson, R. E. and New, M. I.: Juvenile hypertension caused by overproduction ofrenin within a renal segment. J. Ped., 84: 689, 1974. 8. Risdon, R. A., Young, L. W. and Chrispin, A. R.: Renal hypoplasia and dysplasia: a radiological and pathological correlation. Ped. Rad., 3: 213, 1975. 9. Fry, W. J., Ernst, C. B., Stanley, J. C. and Brink, B.: Renovascular hypertension in the pediatric patient. Arch. Surg., 107: 692, 1973. 10. Stoney, R. J., Cooke, P.A. and String, S. T.: Surgical treatment of renovascular hypertension in children. J. Ped. Surg., 10: 631, 1975. 11. Blyth, H. and Ockenden, B. G.: Polycystic disease of kidney and liver presenting in childhood. J. Med. Genet., 8: 257, 1971. 12. Himmelfarb, E., Rabinowitz, J. G., Parvey, L., Gammill, S. and Arant, B.: The Ask-Upmark kidney. Roentgenographic and pathological features. Amer. J. Dis. Child., 129: 1440, 1975. 13. Royer, P., Habib, R., Broyer, M. and Nouaille, Y.: Segmental hypoplasia of the kidney in children. Adv. Nephrol., 1: 145, 1971. 14. Arant, B. S., Jr., Sotelo-Avila, C. and Berstein, J.: Segmental "hypoplasia" of the kidney (Ask-Upmark). J. Ped., 95: 931, 1979. 15. Ljunggvist, A. and Lagergren, C.: The Ask-Upmark kidney. A congenital renal anomaly studied by micro-angiography and histology. Acta Path. Microbiol. Scand., 56: 277, 1962.