Clinical Radiology (1990) 42, 116-117
Aortic Dissection Presenting as Acute Leg Ischaemia N . R A B Y , J. G I L E S a n d H . W A L T E R S
Departments of Radiology, Dulwich and King's College Hospitals, Denmark Hill, London Lower limb ischaemia as the only or main clinical manifestation of aortic dissection is a rare event. Two cases are presented where this occurred resulting in attempted embolectomy before the correct diagnosis was made. The diagnosis should be considered when embolectomy fails to retrieve thrombus and when angiography demonstrates spiral lucencies within the lumen of large vessels or non-filling of major vascular branches. The value of pre-operative angiography is emphasized. R a b y , N . , Giles, J. & W a l t e r s , H . (1990). Clinical Radiology 42, 116-117. C a s e R e p o r t : A o r t i c D i s s e c t i o n P r e s e n t i n g as A c u t e L e g I s c h a e m i a
T h e p r e s e n t i n g f e a t u r e s o f a c u t e e x t e n s i v e a o r t i c dissect i o n a r e e x t r e m e l y v a r i a b l e . W e p r e s e n t t w o cases o f a o r t i c d i s s e c t i o n in w h o m t h e m a i n f e a t u r e at p r e s e n t a t i o n w a s a c u t e leg i s c h a e m i a r e s u l t i n g in a t t e m p t e d e m e r g e n c y e m b o l e c t o m y b e f o r e t h e t r u e d i a g n o s i s was established.
CASE REPORTS
Case 1. A 58-year-old female patient presented to a district general hospital with a history of acute onset of pain in the right leg. Direct questioning elicited a complaint of a dull aching pain in the chest and abdomen. On examination the right leg was cold and white and all pulses were absent. Brachial and radial pulses were present bilaterally and the left leg pulses were normal. ECG showed sinus rhythm with no acute changes. She had a history of hypertension, diabetes and chronic renal failure presumed to be due to reflux nephropathy based on previous IVU findings. A diagnosis of acute right common iliac occlusion was made and embolectomy was attempted under local anaesthesia. The fogarty catheter could not be advanced more than 10 cm proximal to the incision over the right superficial femoral artery. No clot was retrieved and the procedure was abandoned. The patient was referred to the vascular surgeons at our hospital who requested an arteriogram. This was interpreted as showing thrombus within the right common iliac artery, and distal aortic irregularity consistent with atheroma (Fig. 1). The significance of the spiral lucencies in the left superficial femoral artery was not appreciated. The renal arteries were not seen. An operation was delayed as the right leg improved clinically. The patient was treated with heparin (10 000 units/24 h). Over the next 24 h there were difficulties in maintaining her blood pressure. It was necessary to give inotropic support monitored by central arterial and venous line. On this regime the diastolic blood pressure was maintained at 40-60 mmHg with some difficulty. It was then noted that the patient had developed neck and facial swelling and that the right arm pulses were increasingly difficult to feel. Review of her chest radiographs since admission showed that the mediastinum had widened. An aortic dissection was suspected and an arch aortogram was performed (Fig. 2). This confirmed an extensive dissection of the thoracic aorta extending inferiorly. The patient died one hour later. A post-mortem examination confirmed the aortic dissection from a point 2 cm distal to the aortic valve and extending to the upper abdominal aorta. A re-entry point was not identified. The renal arteries were stenosed at their origins. The media was separated from the intima by blood clot, extending from the lower aorta into the right common iliac artery which contained extensive organized thrombus. Case 2. A 72-year-old male patient with a history of hypertension presented to a district general hospital following an acute episode of 'tearing' central chest pain associated with pain in both legs. The only significant finding on examination was absence of all pulses in both legs. ECG showed acute ischaemia and atrial fibrillation. A chest radiograph was unremarkable. A possible diagnosis of aortic dissection was Correspondence to: Dr N. Raby, Department of Radiology, King's College Hospital, London SE5 9RS.
considered but discarded in favour of a saddle embolus secondary to myocardial infarction since it was felt that a dissection would not account for the lower limb ischaemia. An embolectomy from the left groin was attempted but abandoned when it was found that the Fogarty catheter could not be advanced and no clot was retrieved. The patient was referred to our hospital. Ultrasound of the abdominal aorta showed an intimal flap. Angiography was attempted via a right femoral puncture but the guide wire and catheter were seen to lie within a false lumen. A second attempt was made from the right arm but the same situation was encountered at the aortic arch and the procedure abandoned. The patient died 2 h later. Post-mortem examination confirmed an extensive dissection from the aortic root to the mid superficial femoral arteries.
DISCUSSION T h e s e t w o cases i l l u s t r a t e h o w a c u t e leg i s c h a e m i a may be t h e d o m i n a n t f e a t u r e at p r e s e n t a t i o n o f a o r t i c dissect i o n . B o t h p a t i e n t s h a d a D e B a k e y T y p e 1 dissection ( D e B a k e y et al., 1965), c o m m e n c i n g in t h e ascending a o r t a a n d e x t e n d i n g distal to t h e l i g a m e n t u m arteriosurn. I n case 1 the a b s e n c e o f severe c h e s t p a i n delayed d i a g n o s i s o f a dissection. T h i s is a r e l a t i v e l y r a r e b u t well r e c o g n i z e d s i t u a t i o n o c c u r r i n g in o n l y 5 15% o f cases ( H i r s t et al., 1958; D e B a k e y et al., 1982). It is i m p o s s i b l e to d e t e r m i n e t h e e x a c t s e q u e n c e o f events, e s p e c i a l l y why loss o f a r m pulses o c c u r r e d so late in t h e p r o c e s s . This m a y h a v e b e e n d u e to l a t e r a l e x t e n s i o n o f the arch d i s s e c t i o n w h i c h in the e a r l y stages h a d s p a r e d t h e great vessels. T h e s e c o n d p a t i e n t h a d a m o r e t y p i c a l h i s t o r y of a d i s s e c t i o n w i t h c h e s t p a i n as t h e d o m i n a n t s y m p t o m , but c l i n i c a l l y t h e m o s t u r g e n t p r o b l e m w a s leg ischaemia w h i c h p r o m p t e d i m m e d i a t e s u r g i c a l a c t i o n . T h e combin a t i o n o f c h e s t p a i n a n d leg i s c h a e m i a was n o t t h o u g h t to i n d i c a t e a n a o r t i c dissection. E x t e n s i o n i n t o the iliac vessels o c c u r s in a l m o s t 50% of T y p e 1 d i s s e c t i o n s ( L i n d s a y a n d H u r s t , 1967) b u t clinically a p p a r e n t leg i s c h a e m i a is seen in o n l y 6 % ( D e B a k e y et al., 1982); c h e s t p a i n r e m a i n s t h e d o m i n a n t feature h o w e v e r . T h e r e are few p r e v i o u s ~eports o f leg ischaemia as t h e initial m a n i f e s t a t i o n o f d i s s e c t i o n ( S c h n e i d e r e m a n et al., 1978; W h i t e et al., 1980; Y o u n g et al., 1980). The t h r e e cases r e p o r t e d by W h i t e et al. (1980) b e a r a r e m a r k a b l e s i m i l a r i t y to o u r first p a t i e n t . T h e y p o i n t out t h e pitfalls in p e r f o r m i n g a n g i o g r a p h y o f t h e l o w e r limbs in s u c h p a t i e n t s . U n l e s s d i s s e c t i o n is c o n s i d e r e d in the d i f f e r e n t i a l d i a g n o s i s t h e subtle r a d i o l o g i c a l clues present in t h e l o w e r a o r t a m a y be missed. A s the f i n d i n g s in the
AORTIC DISSECTION PRESENTING AS ACUTE LEG ISCHAEMIA
(a)
1 17
Fig. 2 - Arch aortogram confirms dissection just distal to the aortic root (arrow) extending spirally around the arch into the descending aorta. There is no filling of the left common carotid or subclavian arteries. On the original film occlusion of the right subclavian artery at its origin could also be appreciated.
Although computerized tomography may be utilized in the diagnosis of aortic dissection (Danza et al., 1984) its role is primarily to demonstrate the dissection in the arch region. The full extent of the dissection (particularly in the cases under discussion) is likely to be underestimated since even by scanning at multiple levels it is unlikely that extension into the iliac vessels will be demonstrated. Aortic dissection should be included as a rare cause of limb ischaemia even if there is no history of chest pain. Acknowledgements:We would like to thank Dr D. Taube, Mr J. Keats and Professor V. Kakkar for allowing us to report on these patients who were admitted under their care.
REFERENCES
(b) Fig. 1 - ( a ) Left transfemoral angiogram. Thrombus (T) within right common iliac artery. A spiral lucency (L) is seen in the distal aorta and at the origin of the right internal iliac artery. No contrast is seen in the external iliac artery. (b) Further spiral lucencies are seen in the left superficial femoral artery. The profunda fernoris (P) is occluded at its origin. Delayed flow of contrast is noted in the right external iliac artery.
iliac vessels can explain the clinical situation, the rest of the films may not be examined carefully, as was the case in the first patient. Signs that should besought include: 1 Varying degrees of compression of the lower aortic lumen; .2 Spiral linear lucency of the involved vessels representlng the intimal flap; 3 Occlusion of branches of the main vessels. The first Cluemaybe that the embolectomy is unusually difficult or Unproductive.
Danza, FM, Fusco, A & Falappa, P (1984). Role of CT in the evaluation of dissecting aortic aneurysms. Radiology, 152, 828-832. DeBakey, ME, Henly, WS, Cooley, DA, Morris, GC Jr, Crawford, ES & Beau, AC (1965). Surgical management of dissecting aneurysms of the aorta. Journal of Thoracic & Cardiovascular Surgery, 49, 130149. DeBakey, ME, McCollum, CH & Crawford, ES (1982). Dissection and dissecting aneurysms of the aorta: twenty year follow up of 527 patients treated surgically. Surgery, 92, 11 l 8-1134. Hirst, AE Jr, Johns, VJ Jr & Kime, SW Jr (1958). Dissecting aneurysms of the aorta: review of 505 cases. Medicine, 37, 217-219. Lindsay, J Jr & Hurst, JW (1967). Clinical features and prognosis in dissecting aneurysm of the aorta. Circulation, 35, 880 887. Schneidereman, J, Walden, R & Adar, R (1978). Dissecting aneurysm of the thoracic aorta presenting as iliac artery occlusion. Vascular Surgery, 11, 52-54. White, T J, Pinsten, ML, Scott, RL & Gold, RE (1980). Aortic dissection manifested as leg ischemia. American Journal of Roentgenology, 135, 353-356. Young, JR, Dramer, J & Humphries, A W (1980). Aortic dissection manifested as leg ischemia. American Journal of Roentgenology, 135, 353-356.
Aortic Dissection Presenting as Acute Leg Ischaemia N . R A B Y , J. G I L E S a n d H . W A L T E R S
Departments of Radiology, Dulwich and King's College Hospitals, Denmark Hill, London Lower limb ischaemia as the only or main clinical manifestation of aortic dissection is a rare event. Two cases are presented where this occurred resulting in attempted embolectomy before the correct diagnosis was made. The diagnosis should be considered when embolectomy fails to retrieve thrombus and when angiography demonstrates spiral lucencies within the lumen of large vessels or non-filling of major vascular branches. The value of pre-operative angiography is emphasized. R a b y , N . , Giles, J. & W a l t e r s , H . (1990). Clinical Radiology 42, 116-117. C a s e R e p o r t : A o r t i c D i s s e c t i o n P r e s e n t i n g as A c u t e L e g I s c h a e m i a
T h e p r e s e n t i n g f e a t u r e s o f a c u t e e x t e n s i v e a o r t i c dissect i o n a r e e x t r e m e l y v a r i a b l e . W e p r e s e n t t w o cases o f a o r t i c d i s s e c t i o n in w h o m t h e m a i n f e a t u r e at p r e s e n t a t i o n w a s a c u t e leg i s c h a e m i a r e s u l t i n g in a t t e m p t e d e m e r g e n c y e m b o l e c t o m y b e f o r e t h e t r u e d i a g n o s i s was established.
CASE REPORTS
Case 1. A 58-year-old female patient presented to a district general hospital with a history of acute onset of pain in the right leg. Direct questioning elicited a complaint of a dull aching pain in the chest and abdomen. On examination the right leg was cold and white and all pulses were absent. Brachial and radial pulses were present bilaterally and the left leg pulses were normal. ECG showed sinus rhythm with no acute changes. She had a history of hypertension, diabetes and chronic renal failure presumed to be due to reflux nephropathy based on previous IVU findings. A diagnosis of acute right common iliac occlusion was made and embolectomy was attempted under local anaesthesia. The fogarty catheter could not be advanced more than 10 cm proximal to the incision over the right superficial femoral artery. No clot was retrieved and the procedure was abandoned. The patient was referred to the vascular surgeons at our hospital who requested an arteriogram. This was interpreted as showing thrombus within the right common iliac artery, and distal aortic irregularity consistent with atheroma (Fig. 1). The significance of the spiral lucencies in the left superficial femoral artery was not appreciated. The renal arteries were not seen. An operation was delayed as the right leg improved clinically. The patient was treated with heparin (10 000 units/24 h). Over the next 24 h there were difficulties in maintaining her blood pressure. It was necessary to give inotropic support monitored by central arterial and venous line. On this regime the diastolic blood pressure was maintained at 40-60 mmHg with some difficulty. It was then noted that the patient had developed neck and facial swelling and that the right arm pulses were increasingly difficult to feel. Review of her chest radiographs since admission showed that the mediastinum had widened. An aortic dissection was suspected and an arch aortogram was performed (Fig. 2). This confirmed an extensive dissection of the thoracic aorta extending inferiorly. The patient died one hour later. A post-mortem examination confirmed the aortic dissection from a point 2 cm distal to the aortic valve and extending to the upper abdominal aorta. A re-entry point was not identified. The renal arteries were stenosed at their origins. The media was separated from the intima by blood clot, extending from the lower aorta into the right common iliac artery which contained extensive organized thrombus. Case 2. A 72-year-old male patient with a history of hypertension presented to a district general hospital following an acute episode of 'tearing' central chest pain associated with pain in both legs. The only significant finding on examination was absence of all pulses in both legs. ECG showed acute ischaemia and atrial fibrillation. A chest radiograph was unremarkable. A possible diagnosis of aortic dissection was Correspondence to: Dr N. Raby, Department of Radiology, King's College Hospital, London SE5 9RS.
considered but discarded in favour of a saddle embolus secondary to myocardial infarction since it was felt that a dissection would not account for the lower limb ischaemia. An embolectomy from the left groin was attempted but abandoned when it was found that the Fogarty catheter could not be advanced and no clot was retrieved. The patient was referred to our hospital. Ultrasound of the abdominal aorta showed an intimal flap. Angiography was attempted via a right femoral puncture but the guide wire and catheter were seen to lie within a false lumen. A second attempt was made from the right arm but the same situation was encountered at the aortic arch and the procedure abandoned. The patient died 2 h later. Post-mortem examination confirmed an extensive dissection from the aortic root to the mid superficial femoral arteries.
DISCUSSION T h e s e t w o cases i l l u s t r a t e h o w a c u t e leg i s c h a e m i a may be t h e d o m i n a n t f e a t u r e at p r e s e n t a t i o n o f a o r t i c dissect i o n . B o t h p a t i e n t s h a d a D e B a k e y T y p e 1 dissection ( D e B a k e y et al., 1965), c o m m e n c i n g in t h e ascending a o r t a a n d e x t e n d i n g distal to t h e l i g a m e n t u m arteriosurn. I n case 1 the a b s e n c e o f severe c h e s t p a i n delayed d i a g n o s i s o f a dissection. T h i s is a r e l a t i v e l y r a r e b u t well r e c o g n i z e d s i t u a t i o n o c c u r r i n g in o n l y 5 15% o f cases ( H i r s t et al., 1958; D e B a k e y et al., 1982). It is i m p o s s i b l e to d e t e r m i n e t h e e x a c t s e q u e n c e o f events, e s p e c i a l l y why loss o f a r m pulses o c c u r r e d so late in t h e p r o c e s s . This m a y h a v e b e e n d u e to l a t e r a l e x t e n s i o n o f the arch d i s s e c t i o n w h i c h in the e a r l y stages h a d s p a r e d t h e great vessels. T h e s e c o n d p a t i e n t h a d a m o r e t y p i c a l h i s t o r y of a d i s s e c t i o n w i t h c h e s t p a i n as t h e d o m i n a n t s y m p t o m , but c l i n i c a l l y t h e m o s t u r g e n t p r o b l e m w a s leg ischaemia w h i c h p r o m p t e d i m m e d i a t e s u r g i c a l a c t i o n . T h e combin a t i o n o f c h e s t p a i n a n d leg i s c h a e m i a was n o t t h o u g h t to i n d i c a t e a n a o r t i c dissection. E x t e n s i o n i n t o the iliac vessels o c c u r s in a l m o s t 50% of T y p e 1 d i s s e c t i o n s ( L i n d s a y a n d H u r s t , 1967) b u t clinically a p p a r e n t leg i s c h a e m i a is seen in o n l y 6 % ( D e B a k e y et al., 1982); c h e s t p a i n r e m a i n s t h e d o m i n a n t feature h o w e v e r . T h e r e are few p r e v i o u s ~eports o f leg ischaemia as t h e initial m a n i f e s t a t i o n o f d i s s e c t i o n ( S c h n e i d e r e m a n et al., 1978; W h i t e et al., 1980; Y o u n g et al., 1980). The t h r e e cases r e p o r t e d by W h i t e et al. (1980) b e a r a r e m a r k a b l e s i m i l a r i t y to o u r first p a t i e n t . T h e y p o i n t out t h e pitfalls in p e r f o r m i n g a n g i o g r a p h y o f t h e l o w e r limbs in s u c h p a t i e n t s . U n l e s s d i s s e c t i o n is c o n s i d e r e d in the d i f f e r e n t i a l d i a g n o s i s t h e subtle r a d i o l o g i c a l clues present in t h e l o w e r a o r t a m a y be missed. A s the f i n d i n g s in the
AORTIC DISSECTION PRESENTING AS ACUTE LEG ISCHAEMIA
(a)
1 17
Fig. 2 - Arch aortogram confirms dissection just distal to the aortic root (arrow) extending spirally around the arch into the descending aorta. There is no filling of the left common carotid or subclavian arteries. On the original film occlusion of the right subclavian artery at its origin could also be appreciated.
Although computerized tomography may be utilized in the diagnosis of aortic dissection (Danza et al., 1984) its role is primarily to demonstrate the dissection in the arch region. The full extent of the dissection (particularly in the cases under discussion) is likely to be underestimated since even by scanning at multiple levels it is unlikely that extension into the iliac vessels will be demonstrated. Aortic dissection should be included as a rare cause of limb ischaemia even if there is no history of chest pain. Acknowledgements:We would like to thank Dr D. Taube, Mr J. Keats and Professor V. Kakkar for allowing us to report on these patients who were admitted under their care.
REFERENCES
(b) Fig. 1 - ( a ) Left transfemoral angiogram. Thrombus (T) within right common iliac artery. A spiral lucency (L) is seen in the distal aorta and at the origin of the right internal iliac artery. No contrast is seen in the external iliac artery. (b) Further spiral lucencies are seen in the left superficial femoral artery. The profunda fernoris (P) is occluded at its origin. Delayed flow of contrast is noted in the right external iliac artery.
iliac vessels can explain the clinical situation, the rest of the films may not be examined carefully, as was the case in the first patient. Signs that should besought include: 1 Varying degrees of compression of the lower aortic lumen; .2 Spiral linear lucency of the involved vessels representlng the intimal flap; 3 Occlusion of branches of the main vessels. The first Cluemaybe that the embolectomy is unusually difficult or Unproductive.
Danza, FM, Fusco, A & Falappa, P (1984). Role of CT in the evaluation of dissecting aortic aneurysms. Radiology, 152, 828-832. DeBakey, ME, Henly, WS, Cooley, DA, Morris, GC Jr, Crawford, ES & Beau, AC (1965). Surgical management of dissecting aneurysms of the aorta. Journal of Thoracic & Cardiovascular Surgery, 49, 130149. DeBakey, ME, McCollum, CH & Crawford, ES (1982). Dissection and dissecting aneurysms of the aorta: twenty year follow up of 527 patients treated surgically. Surgery, 92, 11 l 8-1134. Hirst, AE Jr, Johns, VJ Jr & Kime, SW Jr (1958). Dissecting aneurysms of the aorta: review of 505 cases. Medicine, 37, 217-219. Lindsay, J Jr & Hurst, JW (1967). Clinical features and prognosis in dissecting aneurysm of the aorta. Circulation, 35, 880 887. Schneidereman, J, Walden, R & Adar, R (1978). Dissecting aneurysm of the thoracic aorta presenting as iliac artery occlusion. Vascular Surgery, 11, 52-54. White, T J, Pinsten, ML, Scott, RL & Gold, RE (1980). Aortic dissection manifested as leg ischemia. American Journal of Roentgenology, 135, 353-356. Young, JR, Dramer, J & Humphries, A W (1980). Aortic dissection manifested as leg ischemia. American Journal of Roentgenology, 135, 353-356.
