Aortoplasty with the left subclavian flap in older children

J THORAC CARDIOVASC SURG 82:103-106, 1981

Aortoplasty with the left subclavian flap in older children Ten patients between 8 months and 9 years of age (average 4.3 years) underwent surgical relief of coarctation of the aorta by the technique of left subclavian flap aortoplasty. Before operation, nine patients had systolic hypertension in the upper extremity (average 145 mm Hg) and all had a significant pressure gradient across the coarctated aortic segment (average 45 mm Hg). The hospital and late mortality were zero. The follow-up over 7 years has shown complete relief of the coarctation and no ischemic impairment or functional limitation of the left upper extremity. The blood pressure returned to normal in all patients. Hemodynamic and angiographic studies, performed in one case, demonstrated adequate growth of the repaired segment and absence of a pressure gradient across the previously narrowed area. The time interval between the peak of the femoral pulse and the dicrotic notch of the carotid pulse, recorded postoperatively, was normal. We consider the left subclavian flap technique to be the operation of choice in infancy and also in older children, whenever the anatomic configuration of the coarctation suggests that subsequent growth would be severely restricted if other techniques were used.

David I. Hamilton, M.B., B.S., F.R.C.S., Dante Medici, M.D.,* Miguel Oyonarte, M.D., and David F. Dickinson, M.B., Ch.B., M.R.C.P., D.C.H., Liverpool, United Kingdom

DesPite wide experience with the surgical relief of coarctation of the aorta in children over the age of six months, "recoarctation ' and residual hypertension occur in a significant proportion of cases. I. 2 Of the several techniques available for the repair of coarctation in infancy, subclavian flap aortoplasty" offers certain advantages at the time of operation, which have been described previously in a series of forty-five babies under the age of six months." Experience with conventional coarctation repair in this group has shown a high frequency of residual or recurrent coarctation. 5- l o However, follow-up over a period of up to 7 years in our patients having coarctation repair by the subclavian flap procedure shows an absence of recoarctation and normal blood pressure for age in the right upper limb in all cases." Because of our favorable iniFrom the Royal Liverpool Children's Hospital, Liverpool, United Kingdom. Supported by the National Heart Research Fund. Received for publication Nov. 10, 1980. Accepted for publication Dec. 29, 1980. Address for reprints: David I. Hamilton, M.B., B.S., F.R.C.S., Consultant Cardiothoracic Surgeon, the Royal Liverpool Children's Hospital, Myrtle 'Street, Liverpool L7 7DG, United Kingdom. 'Present address: Istituto di Chirurgia del Cuore e dei Grossi Vasi, University of Parma, Italy.

tial experience with this procedure and the similar experience of others, 11 we have widened its application to selected older children. This report reviews our experience in this group of patients.

Patients and methods Between 1954 and 1978, 287 children of all ages were operated upon for coarctation of the aorta at the Royal Liverpool Children's Hospital. Of these, 85 were infants under 6 months of age in whom the left subclavian artery flap technique was used. A further 10 children (six boys and four girls) between 8 months and 9 years of age (mean 4.3 years) underwent operation for coarctation by this same technique. These older patients are the subject of this report. At the time of operation all the patients were asymptomatic. Systolic hypertension in the upper extremity was present in nine patients, with systolic blood pressures ranging from 125 to 170 mm Hg, mean 140 mm Hg (Fig. I). The preoperative electrocardiogram showed evidence of left ventricular hypertrophy in seven patients, right ventricular hypertrophy in one patient, and no abnormalities in the remaining two patients. Cardiac catheterization data were available in all 10 patients. The mean gradient across the site of coarc-

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The Journal of Thoracic and Cardiovascular Surgery

104 Hamilton et al.

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Fig. 1. Preoperative and postoperative peak systolic blood pressure (B .P .) measured in the right upper limb against age of child at operation. Broken lines denote 2 standard deviations from normal blood pressure for the age of the child. Table I. Mean time interval between peak of femoral pulse and dicrotic notch of carotid pulse (PF/CDN) in patients who had had coarctation repair and in normal control subjects PF-CDN time interval (se c)

Mean

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Controls (n = 7)

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0.09 ::!:0.020 0.06 to 0.1 3

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tation was 45 mm Hg (range 20 to 75 mm Hg) . Associated cardiac lesions (pate nt ductus two patients , valvular aortic stenosis one patient, and mitral stenosis one patient) were noted in four children , and in three patients a ventricular septal defect documented by cardiac catheterization in infancy was shown to have closed spontaneously . In two patients a previous attempt had been made to repair the coarctation-by an isthrnoplastic procedure 12 in one case and by a Dacron gusset repair in the other. In all patients , the subclavian flap procedure was used, as previously described." Following operation, indirect carotid and femoral arterial pulse tracings were recorded simultaneously in seven patients by the technique of Laurencet and Bussrnan.P Our 14 experience with this technique for the assessment of patients who have had coarctation repair has been reported previously . The time interval

Fig. 2. Angiogram showing area of reconstruction of aortic coarctation 3'/2 years postoperatively. between the peak of the femoral pulse and the dicrotic notch of the carotid pulse was measured and compared with that of a group of seven normal children matched for age with the coarctation patients .

Results and follow-up Surgical anatomy. In the two youngest patients . aged 8 and 14 months, the coarctation was localized and the aortic isthmus was of relatively normal diameter for the age of the patient. The two patients who had had previous coarctation operations showed evidence of failure of growth of the previously repaired area, for there was a long narrow segment distal to the left subcla vian artery. The remaining six patients had hypoplasia of the aortic isthmus , varying from an external diameter of 5 mm in a 4-year-old patient to 8 mm in a 9-year-old child. In all cases the length of the hypo plastic segment would have made direct end-to-end anastomosis after resection impractical. There was no operative mortality among the 10 patients , and postoperative complications were limited to Horner 's syndrome in one patient.

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Aortoplasty with left subclavian flap

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Fig. 3. Simultaneous indirect tracings of the femoral and carotid arterial pulses from a patient who had had coarctation repair. A phonocardiogram and Lead II of the electrocardiogram (ECG II) are also shown. Time lines are 0.04 second apart. The time interval between the peak of the femoral pulse and dicrotic notch of the carotid pulse is 0.11 second. The period of follow-up extended from 2.7 to 7 years (mean 4.5 years). The blood pressure measured by a sphygmomanometer in the right upper limb was within normal limits for age I S in all cases (Fig. I). No patient had a pressure gradient between the right arm and leg exceeding 10 mm Hg at the time of the most recent follow-up visit. In seven patients the electrocardiogram was normal. Two patients showed a reduction of the left ventricular voltages from the preoperative levels, and in the patient with aortic stenosis the electrocardiogram was unchanged. Angiographic and hemodynamic studies were performed on one patient 3.5 years after operation . No pressure gradient was recorded across the site of the repair and the angiographic appearances were satisfactory (Fig . 2). Indirect carotid and femoral artery pulse tracings were recorded simultaneously in seven children 1.1 to 5 years (mean 3.5 years) following operation . The time intervals between the peak of the femoral pulse and the dicrotic notch of the carotid pulse in these patients were not significantly different from those of the age matched-control subjects (Table I). Fig. 3 shows the tracing obtained after operation in one patient.

Discussion In children the potential for growth of a reconstructed aortic segment is questionable , whether repair has been effected by end-to-end anastomosis, patch graft , or an isthmoplastic procedure . 6- 8. 16-1 8 Our' ex-

perience at the Royal Liverpool Children's Hospital since 1969 in infants under 6 months of age suggests that hypertension can be avoided and subsequent normal growth of the repaired aorta can be achieved by using the left subclavian flap aortoplasty . In five infants under 6 months of age at the time of operation" and in one patient in the present series, follow-up cardiac catheterization has confirmed the absence of a pressure gradient and angiograms have demonstrated satisfactory growth of the repaired aortic segment. In patients with normal blood pressure and no pressure gradient demonstrable by sphygmomanometry following repair of coarctation , invasive investigation does not seem justifiable , particularly in the pediatric age group. Therefore, we have used indirect pulse pressure recordings 13. 14 . 19 to asses s the transmission of the arterial pulse wave to the lower extremity. The finding of a normal time interval between the peak of the femoral pulse and the dicrotic notch of the carotid pulse after operation in seven of our patients suggests that the pulse wave transmission in these patients is normal and provides further evidence of a satisfactory repair. Ischemic impairment of the left arm has not caused any concern in our patients , and some children have recovered palpable left radial pulsation . A slight volume and length difference of the left arm in comparison with the right arm has been observed, but there have been no functional limitations. 20 Although the duration of follow-up of both the present patients and the infant group" is relat ively short, the initial results are en-

I 06 Hamilton et al.

couraging. Because of these considerations, it is the current policy at the Royal Liverpool Children's Hospital to use a left subclavian flap technique in infants as well as in selected older children when the anatomic configuration of the coarctation, particularly long tubular narrowing of the isthmus, suggests that its potential for growth would be severely restricted by either end-to-end anastomosis or insertion of nonviable graft material. In these circumstances, the viable pedicle flap appeals to us as the most likely method of ensuring adequate growth in girth of the aorta and diminishes the possibility of recoarctation with its attendant problems. REFERENCES

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The Journal of Thoracic and Cardiovascular Surgery

Lennox SX, Cleland WP, Lincoln C, Joseph MC, Anderson RH: Coarctation of the aorta in infancy and childhood. Br Heart J 38:375-380, 1976 9 Tawes RL, Aberdeen E, Waterston DJ, Bonham-Carter RE: Coarctation of the aorta in infants and children. A review of 333 operative cases, including 173 infants. Circulation 39, 40:Suppl I: 173, 1969 10 Williams WG, Shindo G, Trusler GA, Dische MR, Olley PM: Results of repair of coarctation of the aorta during infancy. J THORAC CARDIOVASC SURG 79:603-608, 1980 II Pierce WS, Waldhausen JA, Berman W, Whitman V: Late results of the subclavian flap procedure in infants with coarctation of the thoracic aorta. Circulation 58: Suppl 1:78-82, 1978 12 Vossschuite K: Surgical correction of coarctation of the aorta by an isthmusplastic operation. Thorax 16:338-345, 1961 13 Laurencet FL, Bussman WD: Valeur de la mecanographie dans Ie diagnostique de la stenose isthmique de 1'aorte. Arch Mal Coeur 63:532-536, 1972 14 Oyonarte M, Dickinson DF, Medici D, Hamilton 01: Indirect arterial pulse tracings in children with coarctation of the aorta before and after operation. Thorax 35: 128132, 1980 15 Nadas AS, Fyler PC: Paediatric Cardiology, Philadelphia, 1972, W. B. Saunders Company, p 665 16 Ibarra-Perez C, Castaneda AR, Varco RL, Lillehei CW: Recoarctation of the aorta. Nineteen year clinical experience. Am J Cardiol 23:778-784, 1969 17 Lindesmith GL, Stanton RE, Stiles AR, Meyer BW, Jones JC: Coarctation of the thoracic aorta. Ann Thorac Surg 11:482-497, 1971 18 Pelletier C, Davignon A, Ethier MF, Stanley P: Coarctation of the aorta in infancy. Postoperative follow-up. J THORAC CARDIOVASC SURG 57:171-179, 1969 19 Kuhn LA, Sapon SO, Grishman A, Donoso E: The use of indirect arterial pulse tracing in the diagnosis of congenital heart disease. Coarctation of the aorta. Pediatrics 18: 193-204, 1956 20 Todd PJ, Wright JOC, Hamilton 01, Dangerfield P, Wilkinson JL: Late effects on the left arm of subclavian flap aortoplasty, Proceedings-World Congress of Paediatric Cardiology, London, June, 1980