|Home | About | Journals | Submit | Contact Us | Français|
In children, coarctation of the aorta is often repaired by use of the initial segment of the left subclavian artery as a patch to widen the narrow segment.1 The left arm then relies on development of collateral vessels.
A woman of 22 sought advice about a cold left hand and exercise-related left arm pain. She was a postgraduate student and had found it difficult to type her thesis. There was a history of cardiovascular surgery in early life. At the age of three weeks a localized pre-ductal aortic coarctation had been diagnosed in association with a patent ductus arteriosus and a large ventricular septal defect (VSD). Initially, the aortic coarctation had been repaired by a subclavian flap angioplasty technique (this included ligation of the left vertebral artery), with simultaneous ligation of the ductus arteriosus. 4 years later the persistent VSD had been repaired.
On examination, her left arm was normally developed but the hand felt cold and none of the arm pulses was palpable. With a hand-held doppler the left brachial pressure was 95 mmHg compared with 120 mmHg on the right. An angiogram confirmed absence of the left subclavian artery at its origin (Figure 1). The artery re-formed 3 cm distally and was hypoplastic in appearance (Figure 2). There was no recurrence of the aortic coarctation or VSD (on echocardiography). In view of the severity of symptoms, a left carotid to subclavian arterial bypass (with 6 mm diameter Dacron graft) was performed via a single supraclavicular incision, and she was discharged five days later with a warm hand and palpable arm pulses. An arterial duplex scan at two months confirmed that the bypass was functioning, with equivalent arm pressures.
Coarctation of the aorta accounts for 3-8% of all congenital cardiac abnormalities, and is associated with at least one other cardiac abnormality in 59-92% of cases.1,2 Most infants born with a large VSD and coarctation develop severe congestive cardiac failure in the first month of life, necessitating urgent cardiac surgery.3,4 The repair of aortic coarctation in neonates and infants can be undertaken either by resection and end-to-end anastomosis or by use of the proximal left subclavian artery to patch and widen the coarctation.1,2,4 The latter technique was introduced in 1966 and is associated with better survival and lower rates of recurrence.3 When it is used in neonates and infants, the general view is that adequate collateral circulation develops to prevent any clinically important morbidity, with an adverse event rate of around 0.2%.3,5 However, there are a few reports of impaired left arm blood flow leading to limb shortening, decrease in limb girth and mild symptoms of ischaemia on strenuous exercise.4,5
In our patient, symptoms become troublesome 22 years after repair of her coarctation. We have found only one other case report of such late presentation; in that report the patient had an acute juxta-vertebral thrombosis of the subclavian artery which caused symptoms despite a collateral supply from the intercostal arteries, the thyrocervical trunk and the costocervical system.6 The vertebral artery is an important source of collateral supply in the presence of disease at the origin of the subclavian artery. It is not routine practice to ligate this during subclavian flap angioplasty of aortic coarctation. Sacrifice of this at the initial procedure in our patient may account for the inadequate development of collateral supply. With improved long-term survival and the increasing cohort of patients with subclavian flap angioplasty reaching adulthood, clinicians should be aware of their potential susceptibility to arterial insufficiency.