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Hypertension in Childhood from Renal Vein Thrombosis
0022-534 7/79 /1223-0389$02.00/0
Vol. 122, September
THE JOURNAL OF UROLOGY
Copyright© 1979 by The Williams & Wilkins Co.
Printed in U.S.A.
HYPERTENSION IN CHILDHOOD FROIVI RENAL VEIN THROMBOSIS JOSEPH A. SMITH, JR., RICHARD E. LEE
AND
RICHARD G. MIDDLETON
From the Division of Urology, Department of Surgery, University of Utah College of Medicine, Salt Lake City, Utah
ABSTRACT
A case is presented of a the :right kidney. The The left
yp,e:rte11mon resulting from abnormal renin production infarction and atrophy to renal vein inferior vena cava thrombos:is because of the vrle1·teu,;10n was cured remains n.o.rmotem,i.ve and wi.th a normal serum creatin.ine at
occrns much less in children. than in However, as oppo,sea. to in which the majority of cases a1"e classified as essential, a cause can be found in children, Renovascula.r lesions am often 1nctp.!1c2,te,d, with primary glomernlar disease and renal ai"te:ry stenosis being among the most common etiologies. Renal vein thrombosis is a :ra:re but acknowledged cause of hypertension in children. Herein we report a case of the successful diagnosis and cure of hypertension in a child se,cm1euH to renal vein thrombosis.
cases occu:r in children, with the of them in neonates. has been rc,,no-rt~,n sel.dom as a vein thrombosis, t,;xpermneJ[lt~ll studies have shown that the fate of the kidney after :renal vein thrombosis upon the development of venous collaterals. After ligation of the renal vein in the dog 1 or in rabbits 2 the kidney undergoes passive congestion and there is a transient increase in blood pressure. However, after a few weeks satisfactory venous collaterals may develop, which decrease the congestion and allow the return of normal renal
CASE REPORT
M. H., a 1-year-old boy, was seen by the pediatrician because of an upper respiratory infection. A chest x-ray showed cardiomegaly with a left ventricular predominance. An electrocardiogram was normal but an echocardiogram revealed left ventricular hypertrophy. Blood pressure was 210/140. The child had been the product of a normal pregnancy and delivery and had normal developmental milestones. Physical examination was unremarkable except for the severe hypertension. were normal, blood urea nitrogen (BUN) 14, creatinine 0.5 and hematocrit 45 per cent. Urinalysis was normal. Excretory urogrnphy (IVP) showed non-visualization. of the right kidney and a somewhat hypertrophied but otherwise normal left kidney. A bullet-shaped calcification was noted just to the right of the Tll vertebra and was believed to represent a calcified inferior vena cava thrombus (fig. 1). Arte:riography disclosed an atrophic right kidney with a small, single renal artery. The left kidney had normal vasculatu:re (fig. 2, A). Inferior venacavog:raphy was attempted but an obstrnction was met at the most distal extent of the inferior vena cava. Injection of contrast material into the right common iliac vein confirmed the diagnosis of inferior vena cava and renal vein thrombosis. The venous system was filled via large collateral lumbar and paraverteb:ral vessels (fig. 2, B). The peripheral renin value was 6.5 ng./ml. (normal in this laboratory is 0.5 to 1.6 ng./ml.). A right nephrectomy was performed through a flank incision, Gentle palpation of the retroperitoneum in the area of the inferior vena cava :revealed a cord-like, rubbery structure that was the thrombosed inferior vena cavao Blood pressure was 140/90 when the patient was discharged from the hospital 5 days postoperatively and it was 110/70 3 weeks later. He has remained normotensive through 1 year of followup and the peripheral renin levels have :returned to normal. DISCUSSION
Renal vein thrombosis is not rare and about 80 per cent of all Urological
FIG. l. JVP dern.onstrates non-functioning right kidney. Note calci5.cation at Tl] vertehral body,
389
390
SMITH, LEE AND MIDDLETON
FIG. 2. A, arteriogram shows atrophic right kidney. B, injection of contrast material into right common iliac artery demonstrates obstruction of inferior vena cava with filling via large collateral veins.
function and blood pressure. However, if the kidney is wrapped in a cellophane container to prevent collateral development it will undergo hemorrhagic infarction and atrophy with a sustained elevation of blood pressure. Because of its more extensive potential for collateral development, the left kidney is more likely to recover than the right kidney after an acute renal vein thrombosis. 3 • 4 Both kidneys are drained by small, perirenal veins that perforate the renal capsule and communicate with the adrenal, gonadal, lumbar and ureteral veins. However, the gonadal, adrenal and inferior phrenic veins usually drain into the left renal vein, whereas on the right side they enter the inferior vena cava directly. Renal vein thrombosis most often develops in neonates during the periods of relative volume depletion, as may occur with bouts of enteritis or ileocolitis. Extension of the thrombus to the inferior vena cava is less common. When thrombosis of the inferior vena cava does occur the intrathoracic portion is involved rarely, since the proximal extension of the thrombus is limited by the high volume of blood from the hepatic veins. 5 The thrombus may calcify at this point just below the entrance of the hepatic veins. This typical bullet-shaped calcification at the level of Tll or T12, as seen in our case, is pathognomonic of inferior vena cava thrombosis. Our case demonstrates many of the points discussed. As is frequently the case, the acute thrombosis was undetected but involved both renal veins and the inferior vena cava. The left kidney developed venous collaterals sufficient to maintain normal renal function but the right kidney underwent infarction and atrophy. Because of relative ischemia of the remaining functional parenchyma of the right kidney it became a source of abnormal renin production, resulting in severe hypertension. REFERENCES 1. Friedberg, L.: The effect of renal vein occlusion on the blood
pressure of the dog. Amer. Heart J., 28: 786, 1944. 2. Bell, E. T. and Pederson, A. H.: The causes of hypertension. Ann. Intern. Med., 4: 277, 1930. 3. Bernie, J.E., Friedel, W. E., Fernandez, R. and Schutte, H.: Left renal vein thrombosis treated conservatively. J. Urol., 107: 517, 1972. 4. McDonald, P., Tarar, R., Gilday, D. and Reilly, B. J.: Some radiologic observations in renal vein thrombosis. Amer. J. Roentgen., 120: 368, 1974. 5. Harrison, C. V., Milne, M. D. and Steiner, R. E.: Clinical aspects of renal vein thrombosis. Quart. J. Med., 25: 285, 1956.
EDITORIAL COMMENT The authors have presented an unusual cause of hypertension in the pediatric age group, secondary renal atrophy following unrecognized renal vein thrombosis. Because hypertension commonly is secondary in children, one must search diligently for an etiology. The important diagnostic clue in this entity was the non-functioning right kidney in conjunction with a calcified thrombus in the inferior vena cava. Despite this report, the entity remains an uncommon cause of hypertension and does not justify early prophylactic nephrectomy in renal vein thrombosis in the infant. Ronald Rabinowitz Division of Urologic Surgery and Pediatrics University of Rochester Medical Center Rochester, New York
REPLY BY AUTHORS Although renal vein thrombosis in infants is fairly common renal atrophy and hypertension are rare. However, calcification of an inferior vena cava thrombus is an important radiologic finding of which urologists should be aware. Of course, the rarity of hypertension does not justify early prophylactic nephrectomy since the majority of these kidneys do not undergo atrophy.
Vol. 122, September
THE JOURNAL OF UROLOGY
Copyright© 1979 by The Williams & Wilkins Co.
Printed in U.S.A.
HYPERTENSION IN CHILDHOOD FROIVI RENAL VEIN THROMBOSIS JOSEPH A. SMITH, JR., RICHARD E. LEE
AND
RICHARD G. MIDDLETON
From the Division of Urology, Department of Surgery, University of Utah College of Medicine, Salt Lake City, Utah
ABSTRACT
A case is presented of a the :right kidney. The The left
yp,e:rte11mon resulting from abnormal renin production infarction and atrophy to renal vein inferior vena cava thrombos:is because of the vrle1·teu,;10n was cured remains n.o.rmotem,i.ve and wi.th a normal serum creatin.ine at
occrns much less in children. than in However, as oppo,sea. to in which the majority of cases a1"e classified as essential, a cause can be found in children, Renovascula.r lesions am often 1nctp.!1c2,te,d, with primary glomernlar disease and renal ai"te:ry stenosis being among the most common etiologies. Renal vein thrombosis is a :ra:re but acknowledged cause of hypertension in children. Herein we report a case of the successful diagnosis and cure of hypertension in a child se,cm1euH to renal vein thrombosis.
cases occu:r in children, with the of them in neonates. has been rc,,no-rt~,n sel.dom as a vein thrombosis, t,;xpermneJ[lt~ll studies have shown that the fate of the kidney after :renal vein thrombosis upon the development of venous collaterals. After ligation of the renal vein in the dog 1 or in rabbits 2 the kidney undergoes passive congestion and there is a transient increase in blood pressure. However, after a few weeks satisfactory venous collaterals may develop, which decrease the congestion and allow the return of normal renal
CASE REPORT
M. H., a 1-year-old boy, was seen by the pediatrician because of an upper respiratory infection. A chest x-ray showed cardiomegaly with a left ventricular predominance. An electrocardiogram was normal but an echocardiogram revealed left ventricular hypertrophy. Blood pressure was 210/140. The child had been the product of a normal pregnancy and delivery and had normal developmental milestones. Physical examination was unremarkable except for the severe hypertension. were normal, blood urea nitrogen (BUN) 14, creatinine 0.5 and hematocrit 45 per cent. Urinalysis was normal. Excretory urogrnphy (IVP) showed non-visualization. of the right kidney and a somewhat hypertrophied but otherwise normal left kidney. A bullet-shaped calcification was noted just to the right of the Tll vertebra and was believed to represent a calcified inferior vena cava thrombus (fig. 1). Arte:riography disclosed an atrophic right kidney with a small, single renal artery. The left kidney had normal vasculatu:re (fig. 2, A). Inferior venacavog:raphy was attempted but an obstrnction was met at the most distal extent of the inferior vena cava. Injection of contrast material into the right common iliac vein confirmed the diagnosis of inferior vena cava and renal vein thrombosis. The venous system was filled via large collateral lumbar and paraverteb:ral vessels (fig. 2, B). The peripheral renin value was 6.5 ng./ml. (normal in this laboratory is 0.5 to 1.6 ng./ml.). A right nephrectomy was performed through a flank incision, Gentle palpation of the retroperitoneum in the area of the inferior vena cava :revealed a cord-like, rubbery structure that was the thrombosed inferior vena cavao Blood pressure was 140/90 when the patient was discharged from the hospital 5 days postoperatively and it was 110/70 3 weeks later. He has remained normotensive through 1 year of followup and the peripheral renin levels have :returned to normal. DISCUSSION
Renal vein thrombosis is not rare and about 80 per cent of all Urological
FIG. l. JVP dern.onstrates non-functioning right kidney. Note calci5.cation at Tl] vertehral body,
389
390
SMITH, LEE AND MIDDLETON
FIG. 2. A, arteriogram shows atrophic right kidney. B, injection of contrast material into right common iliac artery demonstrates obstruction of inferior vena cava with filling via large collateral veins.
function and blood pressure. However, if the kidney is wrapped in a cellophane container to prevent collateral development it will undergo hemorrhagic infarction and atrophy with a sustained elevation of blood pressure. Because of its more extensive potential for collateral development, the left kidney is more likely to recover than the right kidney after an acute renal vein thrombosis. 3 • 4 Both kidneys are drained by small, perirenal veins that perforate the renal capsule and communicate with the adrenal, gonadal, lumbar and ureteral veins. However, the gonadal, adrenal and inferior phrenic veins usually drain into the left renal vein, whereas on the right side they enter the inferior vena cava directly. Renal vein thrombosis most often develops in neonates during the periods of relative volume depletion, as may occur with bouts of enteritis or ileocolitis. Extension of the thrombus to the inferior vena cava is less common. When thrombosis of the inferior vena cava does occur the intrathoracic portion is involved rarely, since the proximal extension of the thrombus is limited by the high volume of blood from the hepatic veins. 5 The thrombus may calcify at this point just below the entrance of the hepatic veins. This typical bullet-shaped calcification at the level of Tll or T12, as seen in our case, is pathognomonic of inferior vena cava thrombosis. Our case demonstrates many of the points discussed. As is frequently the case, the acute thrombosis was undetected but involved both renal veins and the inferior vena cava. The left kidney developed venous collaterals sufficient to maintain normal renal function but the right kidney underwent infarction and atrophy. Because of relative ischemia of the remaining functional parenchyma of the right kidney it became a source of abnormal renin production, resulting in severe hypertension. REFERENCES 1. Friedberg, L.: The effect of renal vein occlusion on the blood
pressure of the dog. Amer. Heart J., 28: 786, 1944. 2. Bell, E. T. and Pederson, A. H.: The causes of hypertension. Ann. Intern. Med., 4: 277, 1930. 3. Bernie, J.E., Friedel, W. E., Fernandez, R. and Schutte, H.: Left renal vein thrombosis treated conservatively. J. Urol., 107: 517, 1972. 4. McDonald, P., Tarar, R., Gilday, D. and Reilly, B. J.: Some radiologic observations in renal vein thrombosis. Amer. J. Roentgen., 120: 368, 1974. 5. Harrison, C. V., Milne, M. D. and Steiner, R. E.: Clinical aspects of renal vein thrombosis. Quart. J. Med., 25: 285, 1956.
EDITORIAL COMMENT The authors have presented an unusual cause of hypertension in the pediatric age group, secondary renal atrophy following unrecognized renal vein thrombosis. Because hypertension commonly is secondary in children, one must search diligently for an etiology. The important diagnostic clue in this entity was the non-functioning right kidney in conjunction with a calcified thrombus in the inferior vena cava. Despite this report, the entity remains an uncommon cause of hypertension and does not justify early prophylactic nephrectomy in renal vein thrombosis in the infant. Ronald Rabinowitz Division of Urologic Surgery and Pediatrics University of Rochester Medical Center Rochester, New York
REPLY BY AUTHORS Although renal vein thrombosis in infants is fairly common renal atrophy and hypertension are rare. However, calcification of an inferior vena cava thrombus is an important radiologic finding of which urologists should be aware. Of course, the rarity of hypertension does not justify early prophylactic nephrectomy since the majority of these kidneys do not undergo atrophy.