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Aortoarteritis of abdominal aorta: An angiographic profile in 110 patients
Clinical Radiology(1993)48, 29 34
Aortoarteritis of Abdominal Aorta: An Angiographic Profile in 110 Patients K. R. M A N D A L A M , S. JOSEPH, V. R. K. RAO, A. K. GUPTA, N. M. UNNI, A. S. RAO, S. K U M A R * , R. SUBRAMANYAN~', S. HALBE, E. V. P. RAO, K. S. NEELAKANDHAN;~ and M. U N N I K R I S H N A N ~
Departments of Radiology and ~Cardiovascular and Thoracic Surgery, Sree Chitra Tirunal Institute for Medical Sciences and Technology, Trivandrum, India, *Department of Radiology, Sanjay Gandhi Post-Graduate Institute of Medical Sciences, Lucknow, India, and tDepartment of Cardiology, Royal Hospital, Sultanate of Oman The angiographic appearances in 110 patients (49 males, 61 females, age range 11-46 years, mean 27.8 years) with aortoarteritis involving the abdominal aorta and/or its branches were analysed. There were 41 aneurysms of the abdominal aorta in 37 patients and eight aneurysms of its branches in as many patients. In 50 patients, 53 obstructive lesions involved the abdominal aorta and were classified as stenoses of focal, segmental and diffuse types and total occlusions. Branch obstructions (182 lesions in 85 patients) affected in order of frequency, the renal, superior mesenteric, coeliac, iliac and the inferior mesenteric arteries. Mesenteric arterial lesions were significantly more common in males (P--0.01). Collateral circulation through a prominent mesenteric arcade was a distinctive angiographic feature in 28 patients. Computed tomography done in four patients showed peri-adventitial thickening and layered thrombus within aneurysms in three patients, and luminal occlusion of the upper abdominal aorta in one patient. Angiographic appearances in aortoarteritis of the abdominal aorta are characteristic and sufficiently distinctive for definitive diagnosis and appropriate management. Mandalam, K.R., Joseph, S., Rao, V.R.K., Gupta, A.K., Unni, N.M., Rao, A.S., Kumar, S., Subramanyan, R., Halbe, S., Rao, E.V.P., Neelakandhan, K.S. & Unnikrishnan, M. (1993). Clinical Radiology 48, 29-34. Aortoarteritis of Abdominal Aorta: An Angiographic Profile in 110 Patients
Accepted for Publication 4 January 1993
Nonspecific aortoarteritis is a chronic disease of unknown aetiology affecting the aorta and its major branches. The disease was originally described by Takayasu in 1908 and was, for a long time, thought to be an exotic Oriental disorder, confined to the aortic arch and its brachiocephalic branches. Subsequent reports, however, indicated a widespread geographic distribution of the disease and extensive involvement o f every part of the aorta and, occasionally, the pulmonary arteries. Based on the topography of the lesions, Lupi et al. [ 1] identified four types, namely those of the aortic arch, thoraco-abdominal aorta, combined type (arch and thoraco-abdominal) and the pulmonary arteries. Arteritis of the abdominal aorta was first reported by Harbitz in 1926. Since then, there have been a number of reports on this variant of the disease, particularly from South East Asia and India. However, a systematic angiographic analysis of its lesions has not been attempted to the best of our knowledge. This study exclusively deals with the detailed angiographic observations in aortoarteritis of the abdominal aorta in a large series of 110 patients. Computed tomographic findings in four patients are also briefly presented.
diagnosed to have aortoarteritis at our Institute. The criteria for diagnosis were: (a) young age at the onset of disease ( < 4 0 years); (b) clinical symptomatology of brachiocephalic, renal or lower limb ischaemia; (c) clinical signs such as diminished or absent pulsations, bruit and pulsatile masses; (d) laboratory findings of raised erythrocytic sedimentation rate and negative serological tests for syphilis, rheumatoid and anti-nuclear factors; and (e) angiographic features of stenosis, occlusion and/ or aneurysmal changes involving the aorta or its major branches or both. Patients with single vessel involvement and features suggestive o f other arteritides (Buerger's disease, collagen disorders) were excluded. Out of 262 patients, 1 l0 patients (49 males, 61 females, age range 1146 years, mean 27.8 years) with lesions involving the abdominal aorta form the subject of the study. All patients underwent angiography (panaortography: 88 patients; abdominal aortography: 22 patients). Four patients underwent computed tomography. The salient clinical features are summarized in Table 1 and angiographic findings in Fig. I.
RESULTS P A T I E N T S AND M E T H O D S .Between January 1976 and June 1992, 262 patients (inclusive of 13 5 patients from a previous report [13]) were Correspondenceto: Dr K. Ravi Mandalam, Additional Professorof Radiology, Sree Chitra Tirunal Institute for Medical Sciences and Technology,Trivandrum 695011, India.
The principal lesions were aneurysms, stenoses and occlusions involving either the abdominal aorta, or its branches or both. Besides tbese, six patients showed diffuse, cylindrical dilatation and 42 patients had marked contour irregularity of the abdominal aorta.
30
CLINICAL
RADIOLOGY
Table 1 - Clinical presentation
Clinicalfeatures
No. of patients
Symptoms Pertaining to hypertension Lower limb claudication Pain in abdomen Others
64 24 2 7
Signs Bruit over abdomen Diminished lower limb pulses Pulsatile mass
46 38 7
ANEURYSMS Supra renal
--
OBSTRUCTIONS 20
Branch
-- 5
Renal
--
105
Superior mesenteric - 34 Inferior mesenteric - 9
1~-21
}Rena~ - 3 t lilac -- 3
7
I
J u x t a renal saccular
Supra renal -- 15
lilac -- 16 l u.
Infra renal - 30 Infra renal -- 9
4
Fig. 3 - Aneurysm of the common hepatic artery in a 25-year-old female. The infrarenal aorta is also aneurysmal.
Fig. 1 - Distribution of lesions in the abdominal aorta in ! 10 patients.
Fig. 4 - Aneurysm of the left renal artery. Similar aneurysmal changes in the infrarenal segment. Abdominal aorta is diffusely irregular in contour.
Fig. 2 - Large fusiform suprarenal aneurysm which extended into the descending thoracic aorta. The right renal and superior mesenteric arteries are occluded.
aneurysms were juxtarenal in location. Fusiform aneurysms involving the hepatic artery (Fig. 3), the renal arteries (Fig. 4) and iliac arteries were seen in eight patients. Obstructions
Aneurysms
Abdominal Aorta
Fusiform aneurysms were overwhelmingly preponderant and affected the suprarenal segment more often than the infrarenal segment (Fig. 2). The entire abdominal aorta was aneurysmal in seven patients. All saccular
While there was considerable variation in the morphology of individual lesions, four types of obstructive lesions c o u l d b e b r o a d l y i d e n t i f i e d ( F i g . 5): (a) Focal stenoses: T h e s e w e r e t h e c o m m o n e s t t y p e a n d
ABDOMINAL AORTOARTERITIS
Focal
Segmental
Diffuse
31
Total occlusion
Fig. 5 - F o u r major types o f obstructive lesions in the abdominal aorta.
Fig. 7 - Tube-like segmental stenosis of the upper infrarenal aorta. Note the mesenterie arcade forming collateral pathway (arrow heads).
Fig. 6 - Focal, 'eoaret-like' stenosis of the aorta immediately above the renal arteries. T h e left renal artery is stenosed. The mesenteric arcade is prominent due to associated occlusion of the superior mesenteric artery.
were annular coarctation-like, local constrictions (Fig. 6)" seen with almost equal frequency in the suprarenal and infrarenal segments. (b) Segmental stenoses: Segments of tubular narrowing ( > 1 cm) of the abdominal aorta were mainly located in the infrarenal segment (10 patients) and mostly smooth in contour (Fig. 7). Such lesions were less common in the suprarenal segment and when located above the coeliac axis were continuous with stenoses in the descending thoracic aorta (Fig. 8). (c) Diffuse stenosis: The entire abdominal aorta showed diffuse luminal stenoses without any intervening normal segment in eight patients. The contour in such cases was often irregular (Fig. 9). (d) Total occlusions: Total occlusion of the lumen was uncommon, the point of occlusion being below the renal arteries in 11 patients. The angiographic appearance in such cases was indistinguishable from atherosclerotic, Leriche-type occlusions. In four cases, high occlusions above the renal arteries were observed. Involvement of the infrarenal aorta was a common feature of these four types of obstructive lesions accounting for 30 of the 53 lesions in 50 patients.
and iliac arteries (14 patients). The lesions were mostly ostial in location, occasionally extending to involve the mainstem of the vessels. Thirty-seven patients had involvement of both renal arteries, and 15 patients had lesions involving two of the three visceral arteries. The coeliac axis (18 patients) and superior mesenteric arteries (34 patients) were much more frequently involved than the inferior mesenteric artery (nine patients),
Branches
Collateral Circulation
The renal arteries were the most commonly involved (68 patients), followed by visceral arteries (40 patients)
Typical patterns of collateral circulation were observed in suprarenal, infrarenal aortic and branch obstructions.
Fig. 8 Long, tube-like stenosis of the upper abdominal aorta extending into the thoracic aorta.
32
CLINICAL RADIOLOGY
(a) (a)
(t,) Fig. 9 - (a) Diffuse narrowing o f the suprarenal aorta. (b) The infrarenal segment and the bifurcation are also diffusely stenosed. Narrowing of the inferior mesenteric artery at its origin.
Suprarenal Occlusions In four patients with high abdominal aortic obstructions, the major collateral pathways were the lower intercostal and lumbar arteries and the internal mammary-superior epigastric-inferior epigastric axis. The latter produced a characteristic 'beaded curtain' appearance (Fig. 10).
Infrarenal Occlusions The collateral circulation in these cases was similar to classic, Leriche-type occlusions, dependent on the lumbar, inferior mesenteric and internal iliac artery branches.
Branch Obstructions Renal artery occlusions were associated with extensive capsular and peri-ureteric collateral circulation, the latter
Fig. 10 - (a) High aortic occlusion above the level o f the renal arteries. The aorta above the occlusion is aneurysmal. (b) 'Beaded curtain' appearance o f collaterals in the rectus sheath and anterior abdominal wall.
often causing ureteral notching in the pyelogram. Mesenteric arterial lesions spared the inferior mesenteric artery in most of the cases, allowing it to become the principal collateral conduit. This route of circulation was also important for aortic occlusions located between the superior and inferior mesenteric arteries. The enlarged mesenteric arcade of Riolan was one of the striking angiographic features and was seen in 28 patients (Figs 6, 7).
CT Scan Findings Four patients, three with abdominal aortic aneutysms and one with thoraco-abdominal aortic occlusion underwent computed tomography. Fusiform aneurysmal dila-
ABDOMINAL AORTOARTERITIS
Fig. 11- Large fusiform abdominal aortic aneurysm with layered thrombus, adventitial calcification and peri-adventitial thickening.
tation with layered thrombus and periaortic thickening was seen in the first three patients (Fig. 11) while the fourth patient showed luminal occlusion. Sex Distribution We tested for any significant deviation of the sex ratio for different lesions, from that observed in the total number of patients, using the binomial distribution and whenever applicable, the normal approximation to the binomial. Most of the lesions conformed to the expected sex ratio of slight female preponderance. However, the male preponderance for visceral arterial lesions and their multiplicity (40 patients (26 male, 14 female): 61 lesions (43 male, 18 female)) was statistically significant (P value= 0.010; P value <0.001). DISCUSSION Arteritis of the abdominal aorta with extension into its mesenteric branches was first described by Harbitz in 1926. However, it was only in the 1950s and 1960s that this condition was recognized to be a part of the larger syndrome of nonspecific aortoarteritis. This form of the disease appears to be more prevalent in South East Asia [2] and India [3,4] in contrast to the aortic arch variety which is more common in Japan. Early reports on abdominal aortoarteritis were anecdotal and gave rise to an assortment of eponyms, such as, stenosing aortitis, coarctation of the abdominal aorta, primary arteritis of the abdominal aorta, etc. Sen e t al. [5] in a classic monograph based on a study of 101 cases gave the first comprehensive description of this form of aortoarteritis. They identified the descending thoracic aorta and the suprarenal abdominal aorta as a major site of predilection for this disease and labelled it as the 'middle aortic syndrome'. In our series the clinical and angiographic findings conformed, in general, to those reported in earlier works
33
[5-9]. There was female preponderance, which was, however, marginal. Hypertension and lower limb ischaemia were the common modes of clinical presentation. On angiography, stenoses and occlusions outnumbered aneurysms. Despite the plethora of lesions that this disease is notorious for, a careful analysis revealed some distinct disease patterns in the abdominal aorta that were remarkable. A m o n g aneurysms the fusiform variety was far more numerous than the saccular variety. This is readily explained by the diffuse nature of the disease affecting the entire circumference and lengthy segments of the vessel wall. There were no dissecting aneurysms involving the abdominal aorta in the present series, an understandable feature considering the dense cicatrization of the vessel wall that characterizes aortoarteritis leaving very few opportunities for intimal-medial separation [8]. Branch aneurysms were seen in a few patients and included two hepatic artery aneurysms hitherto unmentioned in the literature. In general, aneurysms were more common above the level of the renal arteries than below them. This is in sharp contrast to atherosclerotic aneurysms which mainly affect the infrarenal aorta. Among obstructive lesions of the abdominal aorta, four morphological types could be distinguished, namely, focal, segmental, and diffuse stenoses and total occlusions. Complete obstruction of the lumen was less common than stenoses, an observation that has been commented upon by other authors [5,10]. A sizeable number of lesions were either focal (single or multiple) or smooth, tubular constrictions. The infrarenal aorta was more involved by such lesions than the suprarenal segment. These observations assume significance in view of the emerging importance of balloon angioplasty in the management of aortoarteritis [9,11 ]. The frequency of involvement of the branches was similar to those in earlier reports [8,9], the vessels in descending order of involvement being the renal, superior mesenteric, coeliac, iliac and the inferior mesenteric arteries. Most of the lesions were ostial, distal branch lesions being exceptional. Stenoses and occlusions were equally frequent. An interesting observation was the significant male susceptibility for visceral branch involvement, contrary to the overall female dominance in aortoarteritis. The inferior mesenteric artery was relatively immune and was often enlarged to gigantic proportions. The dilated, serpentine mesenteric arcade is, perhaps, the most spectacular angiographic observation in abdominal aortoarteritis. This was first emphasized by Sen e t al. [5] and is considered characteristic of the disease [10]. This anastomotic channel serves as a collateral conduit not only for the abdominal viscera but also for the lower abdominal aorta below the inferior mesenteric ostium (Fig. 7). The pancreatico-duodenal arcade also plays an important role in collateral circulation between the coeliac axis and the superior mesenteric artery. As a result of such excellent, alternate pathways, visceral branch occlusions seldom manifest clinically [7,10,12]. In our series, only two patients had abdominal angina. Computed tomography (CT) is complimentary to angiography and helps to gauge the thickness of the periaortic mantle. This finding is of more than passing academic interest since it forewarns the surgeon about the difficulties during dissection prior to looping the aorta and graft placement. Occasional, totally thrombosed
34
CLINICAL RADIOLOGY
a ne ur ys m s that are occult o n a n g i o g r a p h y , are also best d e m o n s t r a t e d by C T [13]. T h e aet i o l o g y o f a o r t o a r t e r i t i s remains a mystery despite intensive research [14]. C o n s e q u e n t l y , no single l a b o r a t o r y investigation has e m e r g e d that can serve as a definite diagnostic index. A n g i o g r a p h y continues to be the m o s t reliable investigation, b o t h for diagnosis and m a n a g e m e n t . A p r o p e r awareness o f the m a n i f o l d angiographic changes is essential f o r r e c o g n i t i o n a n d t r e a t m e n t o f this disease. Acknowledgements. The authors thank the Director of the Institute for permitting them to publish this paper. The assistance rendered by Dr V. Raman Kutty, Scientist, SCTIMST, for statistical evaluation is gratefully acknowledged. The authors also thank P. J. George and Joy Abraham for the preparation of the illustrations. REFERENCES 1 Lupi-Herera E, Sanchez-Torres G, Marcushamer J, Mispireta J, Horwitz S, Vela JE. Takayasu's arteritis. Clinical study of 107 cases. American Heart Journal 1977;93:94-103. 2 Danaraj TJ, Wong HO. Primary arteritis of abdominal aorta in children causing bilateral stenosis of renal arteries and hypertension. Circulation 1959;20:856-863. 3 Basu AK. Occlusive disease of the aorta and its branches. British Journal of Surgcl'y 1961;49:148-156.
4 sen PK, Kinare SG, Engineer SG, Parulkar GB. The middle aortic syndrome. British Heart Journal 1963;25:610-618. 5 Sen PK. Non-specific aorto-arteritis. A monograph based on a study of I01 cases. Bombay-New Delhi: Tata McGraw Hill, 1972. 6 Lande A, Berkmen YM. Aortitis. Pathologic, clinical and arteriographic review. Radiologic Clinics of North America 1976;14: 219-240. 7 Liu YQ. Radiology of aortoarteritis. Radiologic Clinics o f North America 1985;23:671-688. 8 Yamato M, Lecky JW, Hiramatsu K, Eiichi K. Takayasu arteritis: radiographic and angiographic findings in 59 patients. Radiology 1986; 161:329-334. 9 Park JH, Hart MC, Kim SH, Oh BH, Park YB, Seo JD. Takayasu arteritis: angiographic findings and results of angioplasty. American Journal o f Roentgenology 1989;153:1069-1074. 10 Pokrovsky AV. Nonspecific aortoarteritis. In: Rutherford RB, ed. Vascular surgery. Philadelphia: WB Saunders, 1989:217-237. 11 Kumar S, Ravi Mandalam K, Rao VRK, Subramanyan R, Gupta AK, Joseph S e t al. Percutaneous transluminal angioplasty in nonspecific aortoarteritis (Takayasu's disease): experience of 16 cases. Cardiovascular andlnterventional Radiology 1990;12:321-325. 12 Parulkar GB, Kelkar MD. Nonspecific aortoarteritis. Iri: Rutherford RB, ed. Vascular surgery. Philadelphia: WB Saunders, 1984:731-744. 13 Kumar S, Subramanyan R, Ravi Mandalam K, Rao VRK, Gupta AK, Joseph Set al. Aneurysmal form of aortoarteritis (Takayasu's disease): analysis of thirty cases. Clinical Radiology 1990;42:342347. 14 Balakrishnan KG. Etiopathogenesis of nonspecific aortoarteritis. Editorial comment. Indian Heart Journal 1990;42:89-90.
Aortoarteritis of Abdominal Aorta: An Angiographic Profile in 110 Patients K. R. M A N D A L A M , S. JOSEPH, V. R. K. RAO, A. K. GUPTA, N. M. UNNI, A. S. RAO, S. K U M A R * , R. SUBRAMANYAN~', S. HALBE, E. V. P. RAO, K. S. NEELAKANDHAN;~ and M. U N N I K R I S H N A N ~
Departments of Radiology and ~Cardiovascular and Thoracic Surgery, Sree Chitra Tirunal Institute for Medical Sciences and Technology, Trivandrum, India, *Department of Radiology, Sanjay Gandhi Post-Graduate Institute of Medical Sciences, Lucknow, India, and tDepartment of Cardiology, Royal Hospital, Sultanate of Oman The angiographic appearances in 110 patients (49 males, 61 females, age range 11-46 years, mean 27.8 years) with aortoarteritis involving the abdominal aorta and/or its branches were analysed. There were 41 aneurysms of the abdominal aorta in 37 patients and eight aneurysms of its branches in as many patients. In 50 patients, 53 obstructive lesions involved the abdominal aorta and were classified as stenoses of focal, segmental and diffuse types and total occlusions. Branch obstructions (182 lesions in 85 patients) affected in order of frequency, the renal, superior mesenteric, coeliac, iliac and the inferior mesenteric arteries. Mesenteric arterial lesions were significantly more common in males (P--0.01). Collateral circulation through a prominent mesenteric arcade was a distinctive angiographic feature in 28 patients. Computed tomography done in four patients showed peri-adventitial thickening and layered thrombus within aneurysms in three patients, and luminal occlusion of the upper abdominal aorta in one patient. Angiographic appearances in aortoarteritis of the abdominal aorta are characteristic and sufficiently distinctive for definitive diagnosis and appropriate management. Mandalam, K.R., Joseph, S., Rao, V.R.K., Gupta, A.K., Unni, N.M., Rao, A.S., Kumar, S., Subramanyan, R., Halbe, S., Rao, E.V.P., Neelakandhan, K.S. & Unnikrishnan, M. (1993). Clinical Radiology 48, 29-34. Aortoarteritis of Abdominal Aorta: An Angiographic Profile in 110 Patients
Accepted for Publication 4 January 1993
Nonspecific aortoarteritis is a chronic disease of unknown aetiology affecting the aorta and its major branches. The disease was originally described by Takayasu in 1908 and was, for a long time, thought to be an exotic Oriental disorder, confined to the aortic arch and its brachiocephalic branches. Subsequent reports, however, indicated a widespread geographic distribution of the disease and extensive involvement o f every part of the aorta and, occasionally, the pulmonary arteries. Based on the topography of the lesions, Lupi et al. [ 1] identified four types, namely those of the aortic arch, thoraco-abdominal aorta, combined type (arch and thoraco-abdominal) and the pulmonary arteries. Arteritis of the abdominal aorta was first reported by Harbitz in 1926. Since then, there have been a number of reports on this variant of the disease, particularly from South East Asia and India. However, a systematic angiographic analysis of its lesions has not been attempted to the best of our knowledge. This study exclusively deals with the detailed angiographic observations in aortoarteritis of the abdominal aorta in a large series of 110 patients. Computed tomographic findings in four patients are also briefly presented.
diagnosed to have aortoarteritis at our Institute. The criteria for diagnosis were: (a) young age at the onset of disease ( < 4 0 years); (b) clinical symptomatology of brachiocephalic, renal or lower limb ischaemia; (c) clinical signs such as diminished or absent pulsations, bruit and pulsatile masses; (d) laboratory findings of raised erythrocytic sedimentation rate and negative serological tests for syphilis, rheumatoid and anti-nuclear factors; and (e) angiographic features of stenosis, occlusion and/ or aneurysmal changes involving the aorta or its major branches or both. Patients with single vessel involvement and features suggestive o f other arteritides (Buerger's disease, collagen disorders) were excluded. Out of 262 patients, 1 l0 patients (49 males, 61 females, age range 1146 years, mean 27.8 years) with lesions involving the abdominal aorta form the subject of the study. All patients underwent angiography (panaortography: 88 patients; abdominal aortography: 22 patients). Four patients underwent computed tomography. The salient clinical features are summarized in Table 1 and angiographic findings in Fig. I.
RESULTS P A T I E N T S AND M E T H O D S .Between January 1976 and June 1992, 262 patients (inclusive of 13 5 patients from a previous report [13]) were Correspondenceto: Dr K. Ravi Mandalam, Additional Professorof Radiology, Sree Chitra Tirunal Institute for Medical Sciences and Technology,Trivandrum 695011, India.
The principal lesions were aneurysms, stenoses and occlusions involving either the abdominal aorta, or its branches or both. Besides tbese, six patients showed diffuse, cylindrical dilatation and 42 patients had marked contour irregularity of the abdominal aorta.
30
CLINICAL
RADIOLOGY
Table 1 - Clinical presentation
Clinicalfeatures
No. of patients
Symptoms Pertaining to hypertension Lower limb claudication Pain in abdomen Others
64 24 2 7
Signs Bruit over abdomen Diminished lower limb pulses Pulsatile mass
46 38 7
ANEURYSMS Supra renal
--
OBSTRUCTIONS 20
Branch
-- 5
Renal
--
105
Superior mesenteric - 34 Inferior mesenteric - 9
1~-21
}Rena~ - 3 t lilac -- 3
7
I
J u x t a renal saccular
Supra renal -- 15
lilac -- 16 l u.
Infra renal - 30 Infra renal -- 9
4
Fig. 3 - Aneurysm of the common hepatic artery in a 25-year-old female. The infrarenal aorta is also aneurysmal.
Fig. 1 - Distribution of lesions in the abdominal aorta in ! 10 patients.
Fig. 4 - Aneurysm of the left renal artery. Similar aneurysmal changes in the infrarenal segment. Abdominal aorta is diffusely irregular in contour.
Fig. 2 - Large fusiform suprarenal aneurysm which extended into the descending thoracic aorta. The right renal and superior mesenteric arteries are occluded.
aneurysms were juxtarenal in location. Fusiform aneurysms involving the hepatic artery (Fig. 3), the renal arteries (Fig. 4) and iliac arteries were seen in eight patients. Obstructions
Aneurysms
Abdominal Aorta
Fusiform aneurysms were overwhelmingly preponderant and affected the suprarenal segment more often than the infrarenal segment (Fig. 2). The entire abdominal aorta was aneurysmal in seven patients. All saccular
While there was considerable variation in the morphology of individual lesions, four types of obstructive lesions c o u l d b e b r o a d l y i d e n t i f i e d ( F i g . 5): (a) Focal stenoses: T h e s e w e r e t h e c o m m o n e s t t y p e a n d
ABDOMINAL AORTOARTERITIS
Focal
Segmental
Diffuse
31
Total occlusion
Fig. 5 - F o u r major types o f obstructive lesions in the abdominal aorta.
Fig. 7 - Tube-like segmental stenosis of the upper infrarenal aorta. Note the mesenterie arcade forming collateral pathway (arrow heads).
Fig. 6 - Focal, 'eoaret-like' stenosis of the aorta immediately above the renal arteries. T h e left renal artery is stenosed. The mesenteric arcade is prominent due to associated occlusion of the superior mesenteric artery.
were annular coarctation-like, local constrictions (Fig. 6)" seen with almost equal frequency in the suprarenal and infrarenal segments. (b) Segmental stenoses: Segments of tubular narrowing ( > 1 cm) of the abdominal aorta were mainly located in the infrarenal segment (10 patients) and mostly smooth in contour (Fig. 7). Such lesions were less common in the suprarenal segment and when located above the coeliac axis were continuous with stenoses in the descending thoracic aorta (Fig. 8). (c) Diffuse stenosis: The entire abdominal aorta showed diffuse luminal stenoses without any intervening normal segment in eight patients. The contour in such cases was often irregular (Fig. 9). (d) Total occlusions: Total occlusion of the lumen was uncommon, the point of occlusion being below the renal arteries in 11 patients. The angiographic appearance in such cases was indistinguishable from atherosclerotic, Leriche-type occlusions. In four cases, high occlusions above the renal arteries were observed. Involvement of the infrarenal aorta was a common feature of these four types of obstructive lesions accounting for 30 of the 53 lesions in 50 patients.
and iliac arteries (14 patients). The lesions were mostly ostial in location, occasionally extending to involve the mainstem of the vessels. Thirty-seven patients had involvement of both renal arteries, and 15 patients had lesions involving two of the three visceral arteries. The coeliac axis (18 patients) and superior mesenteric arteries (34 patients) were much more frequently involved than the inferior mesenteric artery (nine patients),
Branches
Collateral Circulation
The renal arteries were the most commonly involved (68 patients), followed by visceral arteries (40 patients)
Typical patterns of collateral circulation were observed in suprarenal, infrarenal aortic and branch obstructions.
Fig. 8 Long, tube-like stenosis of the upper abdominal aorta extending into the thoracic aorta.
32
CLINICAL RADIOLOGY
(a) (a)
(t,) Fig. 9 - (a) Diffuse narrowing o f the suprarenal aorta. (b) The infrarenal segment and the bifurcation are also diffusely stenosed. Narrowing of the inferior mesenteric artery at its origin.
Suprarenal Occlusions In four patients with high abdominal aortic obstructions, the major collateral pathways were the lower intercostal and lumbar arteries and the internal mammary-superior epigastric-inferior epigastric axis. The latter produced a characteristic 'beaded curtain' appearance (Fig. 10).
Infrarenal Occlusions The collateral circulation in these cases was similar to classic, Leriche-type occlusions, dependent on the lumbar, inferior mesenteric and internal iliac artery branches.
Branch Obstructions Renal artery occlusions were associated with extensive capsular and peri-ureteric collateral circulation, the latter
Fig. 10 - (a) High aortic occlusion above the level o f the renal arteries. The aorta above the occlusion is aneurysmal. (b) 'Beaded curtain' appearance o f collaterals in the rectus sheath and anterior abdominal wall.
often causing ureteral notching in the pyelogram. Mesenteric arterial lesions spared the inferior mesenteric artery in most of the cases, allowing it to become the principal collateral conduit. This route of circulation was also important for aortic occlusions located between the superior and inferior mesenteric arteries. The enlarged mesenteric arcade of Riolan was one of the striking angiographic features and was seen in 28 patients (Figs 6, 7).
CT Scan Findings Four patients, three with abdominal aortic aneutysms and one with thoraco-abdominal aortic occlusion underwent computed tomography. Fusiform aneurysmal dila-
ABDOMINAL AORTOARTERITIS
Fig. 11- Large fusiform abdominal aortic aneurysm with layered thrombus, adventitial calcification and peri-adventitial thickening.
tation with layered thrombus and periaortic thickening was seen in the first three patients (Fig. 11) while the fourth patient showed luminal occlusion. Sex Distribution We tested for any significant deviation of the sex ratio for different lesions, from that observed in the total number of patients, using the binomial distribution and whenever applicable, the normal approximation to the binomial. Most of the lesions conformed to the expected sex ratio of slight female preponderance. However, the male preponderance for visceral arterial lesions and their multiplicity (40 patients (26 male, 14 female): 61 lesions (43 male, 18 female)) was statistically significant (P value= 0.010; P value <0.001). DISCUSSION Arteritis of the abdominal aorta with extension into its mesenteric branches was first described by Harbitz in 1926. However, it was only in the 1950s and 1960s that this condition was recognized to be a part of the larger syndrome of nonspecific aortoarteritis. This form of the disease appears to be more prevalent in South East Asia [2] and India [3,4] in contrast to the aortic arch variety which is more common in Japan. Early reports on abdominal aortoarteritis were anecdotal and gave rise to an assortment of eponyms, such as, stenosing aortitis, coarctation of the abdominal aorta, primary arteritis of the abdominal aorta, etc. Sen e t al. [5] in a classic monograph based on a study of 101 cases gave the first comprehensive description of this form of aortoarteritis. They identified the descending thoracic aorta and the suprarenal abdominal aorta as a major site of predilection for this disease and labelled it as the 'middle aortic syndrome'. In our series the clinical and angiographic findings conformed, in general, to those reported in earlier works
33
[5-9]. There was female preponderance, which was, however, marginal. Hypertension and lower limb ischaemia were the common modes of clinical presentation. On angiography, stenoses and occlusions outnumbered aneurysms. Despite the plethora of lesions that this disease is notorious for, a careful analysis revealed some distinct disease patterns in the abdominal aorta that were remarkable. A m o n g aneurysms the fusiform variety was far more numerous than the saccular variety. This is readily explained by the diffuse nature of the disease affecting the entire circumference and lengthy segments of the vessel wall. There were no dissecting aneurysms involving the abdominal aorta in the present series, an understandable feature considering the dense cicatrization of the vessel wall that characterizes aortoarteritis leaving very few opportunities for intimal-medial separation [8]. Branch aneurysms were seen in a few patients and included two hepatic artery aneurysms hitherto unmentioned in the literature. In general, aneurysms were more common above the level of the renal arteries than below them. This is in sharp contrast to atherosclerotic aneurysms which mainly affect the infrarenal aorta. Among obstructive lesions of the abdominal aorta, four morphological types could be distinguished, namely, focal, segmental, and diffuse stenoses and total occlusions. Complete obstruction of the lumen was less common than stenoses, an observation that has been commented upon by other authors [5,10]. A sizeable number of lesions were either focal (single or multiple) or smooth, tubular constrictions. The infrarenal aorta was more involved by such lesions than the suprarenal segment. These observations assume significance in view of the emerging importance of balloon angioplasty in the management of aortoarteritis [9,11 ]. The frequency of involvement of the branches was similar to those in earlier reports [8,9], the vessels in descending order of involvement being the renal, superior mesenteric, coeliac, iliac and the inferior mesenteric arteries. Most of the lesions were ostial, distal branch lesions being exceptional. Stenoses and occlusions were equally frequent. An interesting observation was the significant male susceptibility for visceral branch involvement, contrary to the overall female dominance in aortoarteritis. The inferior mesenteric artery was relatively immune and was often enlarged to gigantic proportions. The dilated, serpentine mesenteric arcade is, perhaps, the most spectacular angiographic observation in abdominal aortoarteritis. This was first emphasized by Sen e t al. [5] and is considered characteristic of the disease [10]. This anastomotic channel serves as a collateral conduit not only for the abdominal viscera but also for the lower abdominal aorta below the inferior mesenteric ostium (Fig. 7). The pancreatico-duodenal arcade also plays an important role in collateral circulation between the coeliac axis and the superior mesenteric artery. As a result of such excellent, alternate pathways, visceral branch occlusions seldom manifest clinically [7,10,12]. In our series, only two patients had abdominal angina. Computed tomography (CT) is complimentary to angiography and helps to gauge the thickness of the periaortic mantle. This finding is of more than passing academic interest since it forewarns the surgeon about the difficulties during dissection prior to looping the aorta and graft placement. Occasional, totally thrombosed
34
CLINICAL RADIOLOGY
a ne ur ys m s that are occult o n a n g i o g r a p h y , are also best d e m o n s t r a t e d by C T [13]. T h e aet i o l o g y o f a o r t o a r t e r i t i s remains a mystery despite intensive research [14]. C o n s e q u e n t l y , no single l a b o r a t o r y investigation has e m e r g e d that can serve as a definite diagnostic index. A n g i o g r a p h y continues to be the m o s t reliable investigation, b o t h for diagnosis and m a n a g e m e n t . A p r o p e r awareness o f the m a n i f o l d angiographic changes is essential f o r r e c o g n i t i o n a n d t r e a t m e n t o f this disease. Acknowledgements. The authors thank the Director of the Institute for permitting them to publish this paper. The assistance rendered by Dr V. Raman Kutty, Scientist, SCTIMST, for statistical evaluation is gratefully acknowledged. The authors also thank P. J. George and Joy Abraham for the preparation of the illustrations. REFERENCES 1 Lupi-Herera E, Sanchez-Torres G, Marcushamer J, Mispireta J, Horwitz S, Vela JE. Takayasu's arteritis. Clinical study of 107 cases. American Heart Journal 1977;93:94-103. 2 Danaraj TJ, Wong HO. Primary arteritis of abdominal aorta in children causing bilateral stenosis of renal arteries and hypertension. Circulation 1959;20:856-863. 3 Basu AK. Occlusive disease of the aorta and its branches. British Journal of Surgcl'y 1961;49:148-156.
4 sen PK, Kinare SG, Engineer SG, Parulkar GB. The middle aortic syndrome. British Heart Journal 1963;25:610-618. 5 Sen PK. Non-specific aorto-arteritis. A monograph based on a study of I01 cases. Bombay-New Delhi: Tata McGraw Hill, 1972. 6 Lande A, Berkmen YM. Aortitis. Pathologic, clinical and arteriographic review. Radiologic Clinics of North America 1976;14: 219-240. 7 Liu YQ. Radiology of aortoarteritis. Radiologic Clinics o f North America 1985;23:671-688. 8 Yamato M, Lecky JW, Hiramatsu K, Eiichi K. Takayasu arteritis: radiographic and angiographic findings in 59 patients. Radiology 1986; 161:329-334. 9 Park JH, Hart MC, Kim SH, Oh BH, Park YB, Seo JD. Takayasu arteritis: angiographic findings and results of angioplasty. American Journal o f Roentgenology 1989;153:1069-1074. 10 Pokrovsky AV. Nonspecific aortoarteritis. In: Rutherford RB, ed. Vascular surgery. Philadelphia: WB Saunders, 1989:217-237. 11 Kumar S, Ravi Mandalam K, Rao VRK, Subramanyan R, Gupta AK, Joseph S e t al. Percutaneous transluminal angioplasty in nonspecific aortoarteritis (Takayasu's disease): experience of 16 cases. Cardiovascular andlnterventional Radiology 1990;12:321-325. 12 Parulkar GB, Kelkar MD. Nonspecific aortoarteritis. Iri: Rutherford RB, ed. Vascular surgery. Philadelphia: WB Saunders, 1984:731-744. 13 Kumar S, Subramanyan R, Ravi Mandalam K, Rao VRK, Gupta AK, Joseph Set al. Aneurysmal form of aortoarteritis (Takayasu's disease): analysis of thirty cases. Clinical Radiology 1990;42:342347. 14 Balakrishnan KG. Etiopathogenesis of nonspecific aortoarteritis. Editorial comment. Indian Heart Journal 1990;42:89-90.