FROM THE DEPARTMENT OF RADIOLOGY, VANDERBILT UNIVERSITY HOSPITAL, NASHVILLE, TENNESSEE 37232, U.S.A.
ROENTGENOLOGIC APPEARANCE OF FIBROMUSCULAR DYSPLASIA L . EKELUND, J. GERLOCK, J. M O L I N and C. SMITH
If Fibromuscular dysplasia of the renal arteries is a well recognized cause of reno vascular hypertension. Many reports have appeared dealing with this entity, but only a few with large series (PALUBINSKAS et coll. 1 9 6 6 — 7 0 cases, KINCAID et coll. 1 9 6 8 — 1 2 5 cases, GILL & MEANEY 1 9 6 9 — 2 0 3 cases, FOSTER et coll. 1 9 6 9 — 5 6 cases).
Certain characteristic angiographic appearances indicating fibromuscular disease of the renal arteries were early stressed (PALUBINSKAS & WYLIE 1 9 6 1 ) , and it is commonly
agreed that the angiographic abnormalities in a typical case are pathognomonic. In spite of the many reported cases, only a few authors have taken interest in the natural history of the disease (KINCAID et coll., MEANEY et coll. 1 9 6 8 ) . Also, only a few re
ports have dealt with the urographic findings in this particular entity. Vanderbilt University Hospital is a specialized center for the investigation and treatment (medical as well as surgical) of renovascular hypertension, with a large patient material. From this material 1 0 0 hypertensive patients with typical angiographic features of fibro muscular disease were selected, and clinical and roentgenologic findings in this material are now presented.
Material and Methods The material comprised 1 0 0 hypertensive patients: 8 3 females and 1 7 males, aged 8 to 6 9 years (mean 4 6 ) with angiographic findings consistent with fibromuscular disease of the renal arteries. Each patient was examined with rapid sequence uroSubmitted for publication 19 January 1977. Acta Radiologica Diagnosis 19 (1978) Fasc. 3 28-785835
433
434
L. EKELUND, J. GERLOCK, J. MOLIN A N D C. SMITH Per cent 50-
41
25+
Fig. 1. Age distribution. Mean age females, 47 years. Mean age males, 43 years.
0. 0-10
10-20
20-30
30-40
40-50
50-60
60-70
Years
graphy (MAXWELL et coll. 1964) and abdominal aortography. Selective nephroangio graphy was performed in most of the cases, usually in several projections in order to obtain optimum information regarding intrarenal arterial involvement. In some cases catheterization of other arteries was also performed (e.g. common carotid, celiac and superior mesenteric arteries). Blood samples from the renal vein were obtained simultaneously from both kidneys for renin determination. Arterial and venous catheterization were performed on different days. Twenty-three patients were operated upon receiving venous grafts. Microscopic documentation was available only in a few cases. Repeat angiography was performed in 28 patients within a time range of 1 to 9 years. In reviewing the urographic findings, the following criteria were evaluated: kidney size, appearance time of contrast medium in the renal pelvis and possible differences in contrast concentration on both sides. Regarding the angiograms, special attention was paid to the distribution of the fibromuscular abnormalities and to the appearance of collaterals. Attempts were also made to evaluate the degree of stenosis created by the disease.
Results There was a striking female sex preponderance, 83 per cent of the patients being women (Table). The mean age for the females was 47 years as compared with an average of 43 for the males (Fig. 1). The youngest patient in the material was an 8-year-old boy with a membraneous stenosis of the main stem of the right renal artery and with collaterals (Fig. 2 a). The peak incidence (41 %) occurred in the fourth decade (Fig. 1). Rapid sequence urography was pathologic in 22 cases (Fig. 3), the most common abnormality being size disparity (length of right kidney exceeding that of the left by more than 1.5 cm, or length of left kidney exceeding that of the right one by more than 2 cm). Delayed appearance of contrast medium in the calyces occurred in 18 patients. The typical 'string of beads' appearance as demonstrated by angiography was found in 73 patients. A short membraneous stenosis was the only abnormality in 5 patients. Bilateral involvement of the renal arteries was demonstrated in 67 cases. Out of the 33 cases with unilateral disease, 31 were found on the right side. The middle and distal third of the main stem of the renal artery was involved
1 IBROMUSCULAR DYSPLASIA
435
Fig. 2. a) Abdominal aortography in 8-year-old boy with hypertension. Short membraneous stenosis in right main renal artery with post stenotic dilation. Collaterals in renal hilum (-*•). b) Postoperative aortography following venous graft. Patient normotensive.
in 93 cases. Segmental arterial involvement to a varying degree was found in 60 patients. Multiple renal arteries were found supplying 32 kidneys, and fibromuscular in volvement was demonstrated in 5 of these supplementary arteries. Often it was difficult to evaluate the degree of stenosis and its hemodynamic significance. How ever, a marked stenosis was found in 29 cases. Collaterals were demonstrated in 17 cases. Adrenal and lumbar arteries were the most common source of these collaterals. Lateralizing renins (ratio > 1.5) were found in 27 patients (Fig. 3). Films from repeat angiography were available in 28 patients (time range 1 to 9 years). In 5 (32-year-old woman, 41-year-old woman, 44-year-old woman, 50-year-old man and 35-year-old woman, reexamined after 2, 2, 2, 5.5 and 9 years, respectively) progression of the disease was demonstrated. In two of these, arterial occlusion and ensuing infarction of the kidney were found (Fig. 5). In the remaining 23 patients no evidence of progression of disease was displayed. Renal ptosis was evident in 12 cases with ipsilateral involvement of the main stem of the renal artery. Aneurysm formation within the main stem of the renal artery or its intrarenal branches occurred in 9 cases (Figs 6, 7). Dissecting fibromuscular lesions existed in 3 renal arteries, in one case leading to partial infarction of the kidney (Fig. 8). Extrarenal manifestation of the disease was noticed in 12 patients, all of whom also
L. EKELUND, J. GERLOCK, J. MOL1N AND C. SMITH
436
83 73
67 60
37.5 31
27
254 17
12
12.5
1 )
23
22
—
IJU
ROENTGENOLOGIC APPEARANCE OF FIBROMUSCULAR DYSPLASIA L . EKELUND, J. GERLOCK, J. M O L I N and C. SMITH
If Fibromuscular dysplasia of the renal arteries is a well recognized cause of reno vascular hypertension. Many reports have appeared dealing with this entity, but only a few with large series (PALUBINSKAS et coll. 1 9 6 6 — 7 0 cases, KINCAID et coll. 1 9 6 8 — 1 2 5 cases, GILL & MEANEY 1 9 6 9 — 2 0 3 cases, FOSTER et coll. 1 9 6 9 — 5 6 cases).
Certain characteristic angiographic appearances indicating fibromuscular disease of the renal arteries were early stressed (PALUBINSKAS & WYLIE 1 9 6 1 ) , and it is commonly
agreed that the angiographic abnormalities in a typical case are pathognomonic. In spite of the many reported cases, only a few authors have taken interest in the natural history of the disease (KINCAID et coll., MEANEY et coll. 1 9 6 8 ) . Also, only a few re
ports have dealt with the urographic findings in this particular entity. Vanderbilt University Hospital is a specialized center for the investigation and treatment (medical as well as surgical) of renovascular hypertension, with a large patient material. From this material 1 0 0 hypertensive patients with typical angiographic features of fibro muscular disease were selected, and clinical and roentgenologic findings in this material are now presented.
Material and Methods The material comprised 1 0 0 hypertensive patients: 8 3 females and 1 7 males, aged 8 to 6 9 years (mean 4 6 ) with angiographic findings consistent with fibromuscular disease of the renal arteries. Each patient was examined with rapid sequence uroSubmitted for publication 19 January 1977. Acta Radiologica Diagnosis 19 (1978) Fasc. 3 28-785835
433
434
L. EKELUND, J. GERLOCK, J. MOLIN A N D C. SMITH Per cent 50-
41
25+
Fig. 1. Age distribution. Mean age females, 47 years. Mean age males, 43 years.
0. 0-10
10-20
20-30
30-40
40-50
50-60
60-70
Years
graphy (MAXWELL et coll. 1964) and abdominal aortography. Selective nephroangio graphy was performed in most of the cases, usually in several projections in order to obtain optimum information regarding intrarenal arterial involvement. In some cases catheterization of other arteries was also performed (e.g. common carotid, celiac and superior mesenteric arteries). Blood samples from the renal vein were obtained simultaneously from both kidneys for renin determination. Arterial and venous catheterization were performed on different days. Twenty-three patients were operated upon receiving venous grafts. Microscopic documentation was available only in a few cases. Repeat angiography was performed in 28 patients within a time range of 1 to 9 years. In reviewing the urographic findings, the following criteria were evaluated: kidney size, appearance time of contrast medium in the renal pelvis and possible differences in contrast concentration on both sides. Regarding the angiograms, special attention was paid to the distribution of the fibromuscular abnormalities and to the appearance of collaterals. Attempts were also made to evaluate the degree of stenosis created by the disease.
Results There was a striking female sex preponderance, 83 per cent of the patients being women (Table). The mean age for the females was 47 years as compared with an average of 43 for the males (Fig. 1). The youngest patient in the material was an 8-year-old boy with a membraneous stenosis of the main stem of the right renal artery and with collaterals (Fig. 2 a). The peak incidence (41 %) occurred in the fourth decade (Fig. 1). Rapid sequence urography was pathologic in 22 cases (Fig. 3), the most common abnormality being size disparity (length of right kidney exceeding that of the left by more than 1.5 cm, or length of left kidney exceeding that of the right one by more than 2 cm). Delayed appearance of contrast medium in the calyces occurred in 18 patients. The typical 'string of beads' appearance as demonstrated by angiography was found in 73 patients. A short membraneous stenosis was the only abnormality in 5 patients. Bilateral involvement of the renal arteries was demonstrated in 67 cases. Out of the 33 cases with unilateral disease, 31 were found on the right side. The middle and distal third of the main stem of the renal artery was involved
1 IBROMUSCULAR DYSPLASIA
435
Fig. 2. a) Abdominal aortography in 8-year-old boy with hypertension. Short membraneous stenosis in right main renal artery with post stenotic dilation. Collaterals in renal hilum (-*•). b) Postoperative aortography following venous graft. Patient normotensive.
in 93 cases. Segmental arterial involvement to a varying degree was found in 60 patients. Multiple renal arteries were found supplying 32 kidneys, and fibromuscular in volvement was demonstrated in 5 of these supplementary arteries. Often it was difficult to evaluate the degree of stenosis and its hemodynamic significance. How ever, a marked stenosis was found in 29 cases. Collaterals were demonstrated in 17 cases. Adrenal and lumbar arteries were the most common source of these collaterals. Lateralizing renins (ratio > 1.5) were found in 27 patients (Fig. 3). Films from repeat angiography were available in 28 patients (time range 1 to 9 years). In 5 (32-year-old woman, 41-year-old woman, 44-year-old woman, 50-year-old man and 35-year-old woman, reexamined after 2, 2, 2, 5.5 and 9 years, respectively) progression of the disease was demonstrated. In two of these, arterial occlusion and ensuing infarction of the kidney were found (Fig. 5). In the remaining 23 patients no evidence of progression of disease was displayed. Renal ptosis was evident in 12 cases with ipsilateral involvement of the main stem of the renal artery. Aneurysm formation within the main stem of the renal artery or its intrarenal branches occurred in 9 cases (Figs 6, 7). Dissecting fibromuscular lesions existed in 3 renal arteries, in one case leading to partial infarction of the kidney (Fig. 8). Extrarenal manifestation of the disease was noticed in 12 patients, all of whom also
L. EKELUND, J. GERLOCK, J. MOL1N AND C. SMITH
436
83 73
67 60
37.5 31
27
254 17
12
12.5
1 )
23
22
—
IJU
