Subclavian Artery Revascularization for Myocardial Ischemia Thierry Reix, MD, G. Jarry, MD, Marie Antoinette Sevestre Pi6tri, MD, J a c q u e s Pi6tri, MD, Amiens, France
A 54-year-old woman had a secondary occlusion of the subclavian artery proximal to the internal mammary artery, which had been used for an anterior interventricular artery bypass, and was the source of recurrent angina. A left carotid-to-subclavian bypass was performed with success. This rare complication underscores the need for careful selection and surveillance of candidates for myocardial revascularization using the internal mammary artery. (Ann Vasc Surg 1991 ;5:546-548). KEY WORDS: Subclavian artery; internal mammary artery; ischemia, myocardial; anterior interventricular artery bypass.
T h e internal m a m m a r y artery l I M A ) is widely used for myocardial r e v a s c u l a r i z a t i o n b e c a u s e o f its excellent long-term p a t e n c y [1]. A m o n g the causes o f failure o f this r e v a s c u l a r i z a t i o n technique is the p r e s e n c e or ulterior d e v e l o p m e n t of p a t h o l o g y in the native subclavian artery (SCA) [2-9]. We report the case o f a patient with c o r o n a r y artery disease w h o relapsed after s e c o n d a r y occlusion of her subclavian artery and w h o r e c o v e r e d when the subclavian artery was restored.
CASE REPORT A 54-year-old woman was hospitalized in September 1989 for unstable angina in the anteroseptal area. Emergency coronary arteriograms were obtained and showed a 90% double stenosis of the anterior descending (interventricular) (ADA) and circumflex arteries. Myocardial revascularization had been performed in another institution. The ADA was revascularized through the left IMA whereas the left marginal (lateral) artery was restored through a reversed saphenous vein graft originating from the aorta. The patient's postoperative course was unFrom the Service de ('hirur~,,ie Thoracique et Cardiovasculaire, ItOpital Sud, Amiens, France. Reprint requests: J. PiOtri, MD, Service de Chirurgie Thoracique et Cardio-Vasculaire, Hbpital Sud, CHRU d'Arniens, BP 3009, 80030 Amiens Cddex, France.
eventful and all symptoms of coronary artery disease disappeared. One month after operation, electrocardiograms and cardiac sonograms revealed a small infarction of the cardiac apex. Follow-up coronary arteriograms through the retrograde femoral route showed that the aorta-tomarginal artery bypass was patent. During attempted catheterization of the left SCA, however, acute dissection occurred and was complicated by occlusion of the left SCA without immediate compromise in the vertebrobasilar, myocardial, or upper limb arterial beds. In December 1989, the patient was readmitted for iterative unstable angina. No pulses could be palpated in the left upper limb. Arterial blood pressure was 170/90 mmHg in the right arm, 120/60 mmHg in the left. Supraaortic Doppler investigation showed an occlusion of the prevertebral left SCA associated with a vertebral artery steal syndrome. Thoracic aortograms were obtained and demonstrated a short proximal occlusion of the prevertebral segment of the left SCA associated with vertebral steal (Figs. 1, 2). The IMA was patent with anterograde flow. There were no other lesions in the supraaortic trunks. Revascularization was perlbrmed through the cervical route. A 30 mmHg pressure drop was tound between the left SCA and common carotid which increased to 60 mmHg when the vertebral artery was clamped. No partitular protective measures were taken with regard to the cerebral or myocardial vasculature except for the maintenance of normotension. Because of a long patent subclavian stump, it was possible to retain the vertebrocor546
VOLUME 5 NO 6 - 1991
S UBCLA VIAN A R T E R Y REVASCULARIZA T10N
Fig. 1. Arch aortogram by femoral route: thrombosis of prevertebral left subclavian artery. onary collaterality by placing the clamp on the SCA proximal to the vertebral artery. The left SCA was transposed to the left common carotid artery. Postoperatively, coronary artery symptoms disappeared. Left upper limb pulses returned and blood pressure was the same in both upper limbs. Follow-up aortograms were obtained and showed that revascularization was satisfactory with anterograde peffusion of the 1MA
Fig. 2. Vertebral-subclavian steal syndrome and anterograde perfusion of left internal mammary artery.
547
Fig. 3. Follow-up arteriograms show carotid-subclavian reimplantation with good perfusion of left internal mammary artery, (Fig. 3). The patient was symptom-free three months after operation.
DISCUSSION Vertebrobasilar or upper limb ischemia constitute the usual indications for SCA revascularization. Myocardial ischemia after IMA bypass is exceptional, We found nine similar observations in the literature whether associated or not with coronarysubclavian artery steal syndrome (Table I). Five of these patients had recurrent coronary symptoms five months to t3 years after initial operation. One patient, in whom the diagnosis of coronary-subclavian artery steal was made retrospectively, died of myocardial ischemia during an attempt at myocardial revascularization. Three patients were entirely free of symptoms and subclavian lesions were s u s p e c t e d as based on the blood pressure gradient between the two upper limbs. This gradient seems to be the best clinical criteria for significant stenosis of the SCA as it was found in all the observations except that of Brown [3]. Preoperative evaluation for myocardial revascularization with IMA bypass should include blood pressure measurement of both upper limbs and research for cervical bruit, upper limb claudication or vertebrobasilar insufficiency. In case of abnormal findings, supraaortic arteriograms should be obtained. Moderate, occasionally evolving lesions of the SCA or those with well developed collaterality can escape detection [4].
548
ANNALS OF
SUBCLA V1AN A R T E R Y REVASCULARIZATION
VASCULARSURGERY
TABLE I.~Symptoms, treatment and outcome of subclavian lesions for myocardial ischemia
Author
Age Sex
Delay
Pressure Angiography gradient Subclavian Mammary Angina (mm Hg) lesion flow Operation Outcome
Harjola
57
M
11 months
No
50
LSC-S 50%
inverted
CSCB
Brown (3)
57
M
0
Yes
0
inverted
No
Tyras (4)
42 40 38
M M F
3 years 15 months
No No Yes
40 50 20
RSC-S 50% post-mortem LSC-S 95% LSC-S 99% LSC-S 80%
inverted inverted direct
CSCB CSCB CSCB
Favorable Favorable Favorable
3 years
Tarazi (6)
55
M
5 months
Yes
20
inverted
CSCB
Favorable
NG
Niemera
68
F
13 years
Yes
20
LSC-S 95% V-O LSC-S 90%
inverted
CSCB
Favorable
3 months
Valentine
57
M
10 years
Yes
50
LSC-O
inverted
CSCB
Favorable 21 months
Olsen (9)
51
F
10 months
Yes
30
inverted
CSCB
Favorable
8 months
Present case
54
F
1 month
Yes
30
LSC-O V-O LSC-O
direct
CSCT
Favorable
3 months
(2)
Bashour
(5) (7) (8)
Favorable
Followup NG
Death NG NG
LSC = left subclavianartery;RSC = rightsubclavianartery;V = vertebralartery;S = stenosis:O = totalocclusion:CSCB = carotido-subclavianbypass;CSCT = transpositionof the subclavianartery intothe carotid:NG - not gvven.
Rather than obtaining routine arteriograms of the supraaortic trunks as proposed by Harjola and associates [2], we use exertional Doppler examination of the upper limb. In addition, this procedure can be used during long-term surveillance of coronary artery bypass. Uncorrected proximal lesions of the SCA preclude the use of the ipsilateral IMA for revascularization, at least in situ. Alternative procedures which can be used in this setting include contralateral IMA bypass, vein graft bypass, or the ipsilateral IMA as a free transplant [3].
CONCLUSION When the SCA is found to be pathological after myocardial revascularization, restoration of the SCA is necessary because of the risk of fatal complications [3]. The procedure of choice is certainly the carotid-to-subclavian bypass which was employed with success in eight of nine patients described in the literature. In our case. the absence of clamping of the vertebral artery allowed us to perform a subclavian-carotid artery transposition without increasing myocardial ischemia. The incidence of this complication, rarely described in the literature, is probably underestimated. Careful selection and surveillance of pa-
InN
tients are mandatory for myocardial revascularization using the in situ IMA.
REFERENCES ! OKIES JE. PAGE US. BIGELOW JC. et al. The left internal mammary artery: the grafl of choice. Circulation 1984:70(Suppl 1):213-221. 2. HARJOLA PT. UALLE M. The importance of aortic arch or subclavian anglography before coronary reconstruction. Chest 1974:66:436-438. 3. BROYN AH. Coronary steal by internal mammary graft with subclavian stenosis. J Thorac Cardiovasc Surg 1977; 73:690-693. 4. TYRAS PH BARNER HB Coronary--subclavian steal. Arch Surg 1977;112:1125-1127. 5. BASHOUR TT. CREY J. KABBANI SS. e t a l . Symptomatic coronary and cerebral steal after internal mammary-coronary bypass. Am Heart J 1984:108:177-178. 6. FARAZI RY. O'HARA PJ. LOOP FD. Symptomatic coronary subclavian steal corrected by carotid--subclavian bypass. J Vas~ Surg !986:3:663-672. 7. NIEMERA ML. HAFT JL. GOLDSTEIN JE. et al. Reirograde internal mammary artery flow and resistant angina pectoris: clues to the coronary-subclavian steal syndrome. Cathet Cardiovasc Diagn 1986:12:93-95. 8. VALENTINE RJ, FRY RE. WHEELAN KR et al. Coronary-subclavian steal from reversed flow in an internal mammary artery used for coronary bypass. Am J Cardiol 1987:59:719-720. 9. OLSEN CO. DUNTON RF. MAGGS PR, et al. Review of coronary-subclavian steal following internal mammary-coronary artery bypass surgery. Ann Thorac Surg 1988:46:675-678.
A 54-year-old woman had a secondary occlusion of the subclavian artery proximal to the internal mammary artery, which had been used for an anterior interventricular artery bypass, and was the source of recurrent angina. A left carotid-to-subclavian bypass was performed with success. This rare complication underscores the need for careful selection and surveillance of candidates for myocardial revascularization using the internal mammary artery. (Ann Vasc Surg 1991 ;5:546-548). KEY WORDS: Subclavian artery; internal mammary artery; ischemia, myocardial; anterior interventricular artery bypass.
T h e internal m a m m a r y artery l I M A ) is widely used for myocardial r e v a s c u l a r i z a t i o n b e c a u s e o f its excellent long-term p a t e n c y [1]. A m o n g the causes o f failure o f this r e v a s c u l a r i z a t i o n technique is the p r e s e n c e or ulterior d e v e l o p m e n t of p a t h o l o g y in the native subclavian artery (SCA) [2-9]. We report the case o f a patient with c o r o n a r y artery disease w h o relapsed after s e c o n d a r y occlusion of her subclavian artery and w h o r e c o v e r e d when the subclavian artery was restored.
CASE REPORT A 54-year-old woman was hospitalized in September 1989 for unstable angina in the anteroseptal area. Emergency coronary arteriograms were obtained and showed a 90% double stenosis of the anterior descending (interventricular) (ADA) and circumflex arteries. Myocardial revascularization had been performed in another institution. The ADA was revascularized through the left IMA whereas the left marginal (lateral) artery was restored through a reversed saphenous vein graft originating from the aorta. The patient's postoperative course was unFrom the Service de ('hirur~,,ie Thoracique et Cardiovasculaire, ItOpital Sud, Amiens, France. Reprint requests: J. PiOtri, MD, Service de Chirurgie Thoracique et Cardio-Vasculaire, Hbpital Sud, CHRU d'Arniens, BP 3009, 80030 Amiens Cddex, France.
eventful and all symptoms of coronary artery disease disappeared. One month after operation, electrocardiograms and cardiac sonograms revealed a small infarction of the cardiac apex. Follow-up coronary arteriograms through the retrograde femoral route showed that the aorta-tomarginal artery bypass was patent. During attempted catheterization of the left SCA, however, acute dissection occurred and was complicated by occlusion of the left SCA without immediate compromise in the vertebrobasilar, myocardial, or upper limb arterial beds. In December 1989, the patient was readmitted for iterative unstable angina. No pulses could be palpated in the left upper limb. Arterial blood pressure was 170/90 mmHg in the right arm, 120/60 mmHg in the left. Supraaortic Doppler investigation showed an occlusion of the prevertebral left SCA associated with a vertebral artery steal syndrome. Thoracic aortograms were obtained and demonstrated a short proximal occlusion of the prevertebral segment of the left SCA associated with vertebral steal (Figs. 1, 2). The IMA was patent with anterograde flow. There were no other lesions in the supraaortic trunks. Revascularization was perlbrmed through the cervical route. A 30 mmHg pressure drop was tound between the left SCA and common carotid which increased to 60 mmHg when the vertebral artery was clamped. No partitular protective measures were taken with regard to the cerebral or myocardial vasculature except for the maintenance of normotension. Because of a long patent subclavian stump, it was possible to retain the vertebrocor546
VOLUME 5 NO 6 - 1991
S UBCLA VIAN A R T E R Y REVASCULARIZA T10N
Fig. 1. Arch aortogram by femoral route: thrombosis of prevertebral left subclavian artery. onary collaterality by placing the clamp on the SCA proximal to the vertebral artery. The left SCA was transposed to the left common carotid artery. Postoperatively, coronary artery symptoms disappeared. Left upper limb pulses returned and blood pressure was the same in both upper limbs. Follow-up aortograms were obtained and showed that revascularization was satisfactory with anterograde peffusion of the 1MA
Fig. 2. Vertebral-subclavian steal syndrome and anterograde perfusion of left internal mammary artery.
547
Fig. 3. Follow-up arteriograms show carotid-subclavian reimplantation with good perfusion of left internal mammary artery, (Fig. 3). The patient was symptom-free three months after operation.
DISCUSSION Vertebrobasilar or upper limb ischemia constitute the usual indications for SCA revascularization. Myocardial ischemia after IMA bypass is exceptional, We found nine similar observations in the literature whether associated or not with coronarysubclavian artery steal syndrome (Table I). Five of these patients had recurrent coronary symptoms five months to t3 years after initial operation. One patient, in whom the diagnosis of coronary-subclavian artery steal was made retrospectively, died of myocardial ischemia during an attempt at myocardial revascularization. Three patients were entirely free of symptoms and subclavian lesions were s u s p e c t e d as based on the blood pressure gradient between the two upper limbs. This gradient seems to be the best clinical criteria for significant stenosis of the SCA as it was found in all the observations except that of Brown [3]. Preoperative evaluation for myocardial revascularization with IMA bypass should include blood pressure measurement of both upper limbs and research for cervical bruit, upper limb claudication or vertebrobasilar insufficiency. In case of abnormal findings, supraaortic arteriograms should be obtained. Moderate, occasionally evolving lesions of the SCA or those with well developed collaterality can escape detection [4].
548
ANNALS OF
SUBCLA V1AN A R T E R Y REVASCULARIZATION
VASCULARSURGERY
TABLE I.~Symptoms, treatment and outcome of subclavian lesions for myocardial ischemia
Author
Age Sex
Delay
Pressure Angiography gradient Subclavian Mammary Angina (mm Hg) lesion flow Operation Outcome
Harjola
57
M
11 months
No
50
LSC-S 50%
inverted
CSCB
Brown (3)
57
M
0
Yes
0
inverted
No
Tyras (4)
42 40 38
M M F
3 years 15 months
No No Yes
40 50 20
RSC-S 50% post-mortem LSC-S 95% LSC-S 99% LSC-S 80%
inverted inverted direct
CSCB CSCB CSCB
Favorable Favorable Favorable
3 years
Tarazi (6)
55
M
5 months
Yes
20
inverted
CSCB
Favorable
NG
Niemera
68
F
13 years
Yes
20
LSC-S 95% V-O LSC-S 90%
inverted
CSCB
Favorable
3 months
Valentine
57
M
10 years
Yes
50
LSC-O
inverted
CSCB
Favorable 21 months
Olsen (9)
51
F
10 months
Yes
30
inverted
CSCB
Favorable
8 months
Present case
54
F
1 month
Yes
30
LSC-O V-O LSC-O
direct
CSCT
Favorable
3 months
(2)
Bashour
(5) (7) (8)
Favorable
Followup NG
Death NG NG
LSC = left subclavianartery;RSC = rightsubclavianartery;V = vertebralartery;S = stenosis:O = totalocclusion:CSCB = carotido-subclavianbypass;CSCT = transpositionof the subclavianartery intothe carotid:NG - not gvven.
Rather than obtaining routine arteriograms of the supraaortic trunks as proposed by Harjola and associates [2], we use exertional Doppler examination of the upper limb. In addition, this procedure can be used during long-term surveillance of coronary artery bypass. Uncorrected proximal lesions of the SCA preclude the use of the ipsilateral IMA for revascularization, at least in situ. Alternative procedures which can be used in this setting include contralateral IMA bypass, vein graft bypass, or the ipsilateral IMA as a free transplant [3].
CONCLUSION When the SCA is found to be pathological after myocardial revascularization, restoration of the SCA is necessary because of the risk of fatal complications [3]. The procedure of choice is certainly the carotid-to-subclavian bypass which was employed with success in eight of nine patients described in the literature. In our case. the absence of clamping of the vertebral artery allowed us to perform a subclavian-carotid artery transposition without increasing myocardial ischemia. The incidence of this complication, rarely described in the literature, is probably underestimated. Careful selection and surveillance of pa-
InN
tients are mandatory for myocardial revascularization using the in situ IMA.
REFERENCES ! OKIES JE. PAGE US. BIGELOW JC. et al. The left internal mammary artery: the grafl of choice. Circulation 1984:70(Suppl 1):213-221. 2. HARJOLA PT. UALLE M. The importance of aortic arch or subclavian anglography before coronary reconstruction. Chest 1974:66:436-438. 3. BROYN AH. Coronary steal by internal mammary graft with subclavian stenosis. J Thorac Cardiovasc Surg 1977; 73:690-693. 4. TYRAS PH BARNER HB Coronary--subclavian steal. Arch Surg 1977;112:1125-1127. 5. BASHOUR TT. CREY J. KABBANI SS. e t a l . Symptomatic coronary and cerebral steal after internal mammary-coronary bypass. Am Heart J 1984:108:177-178. 6. FARAZI RY. O'HARA PJ. LOOP FD. Symptomatic coronary subclavian steal corrected by carotid--subclavian bypass. J Vas~ Surg !986:3:663-672. 7. NIEMERA ML. HAFT JL. GOLDSTEIN JE. et al. Reirograde internal mammary artery flow and resistant angina pectoris: clues to the coronary-subclavian steal syndrome. Cathet Cardiovasc Diagn 1986:12:93-95. 8. VALENTINE RJ, FRY RE. WHEELAN KR et al. Coronary-subclavian steal from reversed flow in an internal mammary artery used for coronary bypass. Am J Cardiol 1987:59:719-720. 9. OLSEN CO. DUNTON RF. MAGGS PR, et al. Review of coronary-subclavian steal following internal mammary-coronary artery bypass surgery. Ann Thorac Surg 1988:46:675-678.
