HOW TO DO IT

Coarctation of the Aorta: Anastomotic Enlargement with Subclavian Artery: Two New Surgicalaptions Charles A. Dietl, M.D., and Albert0 R. Torres, M.D.

ABSTRACT Recoarctation is still observed following sur- gical treatment of coarctation in small infants. Modifica- tions to conventional surgical techniques are suggested to avoid this serious complication. Coarctectomy is per- formed. To obtain a much wider noncircumferential anas- tomosis, the subclavian artery is used to enlarge it either as a flap or by reimplantation. No residual pathological tissue is left behind, and this should help prevent recurrence.

Neonates and small infants with aortic coarctation and congestive heart failure have a poor prognosis. Prompt surgical relief of the obstruction is usually necessary to assure survival [l, 21. Several surgical procedures, in- cluding coarctectomy with end-to-end anastomosis [3, 41, prosthetic patch aortoplasty [5, 61, and subclavian flap repair [2, 7-10], have been employed to obtain re- lief. Mortality and rates of recoarctation used to be ele- vated when the end-to-end anastomosis was employed in infants [4, 5, 8-10]. With new surgical techniques, mortality has been reported to range between 0 and 29%, and the risk is usually attributed to associated com- plex intracardiac anomalies or to a poor preoperative condition [2, 4, 5-10].

Despite improved results, there is still no optimal sur- gical procedure for repair of coarctation, especially in small infants, and the risk of recurrence persists. Cur- rently, the subclavian flap is widely used because the anastomosis has the potential for growth [7-101. How- ever, in patients younger than 3 months, the incidence of recoarctation ranges from 6 to 25% with this technique [2, 8-11] and from 0 to 32% when a prosthetic patch is used [l, 5, 61.

Inadequate excision of the coarctation membrane may lead to residual obstruction [9]. In small infants, how- ever, this tissue is often very friable, and complete exci- sion is impossible. Inevitably, residual coarctation tissue or a rough surface is left inside the aorta. Either can result in granulation or thrombosis, and become an area of restenosis [12]. The area may also become weak and be a source of aneurysms if excessive tissue is peeled off [8, 9, 121.

This same critique is applicable to the subclavian flap and patch arterioplasty. The therapeutic implication is that in young infants, all coarctation tissue should be excised completely to prevent recurrence [ll]. Conse-

From the Department of Pediatric Cardiovascular Surgery, Sanatorio Giiemes and Fundaci6n Favaloro, Buenos Aires, Argentina.

Accepted for publication May 9, 1986.

Address reprint requests to Dr. Dietl, Fundaci6n Favaloro, Solis 453, Buenos Aires 1078, Argentina.

quently, in many centers, the preferred procedure for small infants is coarctectomy and end-to-end anastomo- sis [ll, 131, the goal being to avoid recurrence by using microvascular techniques and absorbable sutures. How- ever, residual gradients are seen in 8 to 9% of these patients [ll, 131.

The purpose of this presentation is to report the early results with enlarged end-to-end anastomoses, which theoretically may be more advantageous than the proce- dures currently being used [14].

Techniques A left posterolateral thoracotomy incision is made. Ade- quate mobilization of the aorta and subclavian artery is essential. While dissection is carried out, the body tem- perature is lowered to 35°C with a cooling blanket. The first technique consists of distal ligation of the subcla- vian artery and the vertebral branch (Fig 1). The ductus arteriosus is ligated close to the pulmonary artery. The aorta is then clamped proximal to the origin of the left subclavian artery and distal to the coarctation. The entire coarctation segment is excised. The ends of the divided aorta are sewn together with running 7-0 monofilament suture, except for a small area anteriorly. A longitudinal incision is made in the anterior surface of the distal aorta and along the entire left subclavian artery, which is di- vided distally. The opened subclavian flap is turned down and sutured to the longitudinal incision proximal and distal to the transverse anastomosis.

The end-to-end anastomosis is therefore enlarged con- siderably with the subclavian flap. The method simulta- neously avoids a circumferential suture line and allows potential growth of the anastomosis. No traction is ap- plied to the subclavian flap, and all the pathological coarctation tissue is completely excised to eliminate pos- sible causes of recoarctation (9, 11, 141.

Subclavian artery ligation can cause upper limb isch- emic and trophic changes in a small number of patients [15]. Therefore, we now prefer to reimplant the left sub- clavian artery, a technique similar to one described by Mendonca and colleagues [ 161. However, to avoid re- stenosis, we recommend coarctectomy as well. This sec- ond technique consists of resection of the coarctation segment and an end-to-end anastomosis with running 7-0 monofilament suture, except for a small area pos- terolaterally (Fig 2). The subclavian artery is divided at its origin, and is sutured longitudinally both proximal and distal to the transverse aortic anastomosis.

Comment The first technique was used on 5 patients from May to December, 1985, including 1 infant with hypoplastic

224 Ann Thorac Surg 43:224-225, Feb 1987

225 How to Do It: Dietl and Torres: Anastomotic Enlargement for Aortic Coarctation

Fig 1 . Coarctectomy and end-to-end anastomosis enlarged with sub- clavian artery Pap. (LSA = left subclavian artery; COA = coarcta- tion; AN = anastomosis; LSF = left subclavian flap.)

Fig 2 . Coarctectomy and end-to-end anastomosis enlarged with reim- planted subclavian artery. (LSA = left subclavian artery; COA = coarctation; AN = anastomosis.)

isthmus. Their ages ranged from 3 weeks to 12 months (mean, 4.1 months) and their weights, from 2.6 to 7.5 kg (mean, 4.4 kg). Three of the patients had associated de- fects. Pulmonary artery banding was not done in any patient. The second technique was utilized on a 3- month-old infant with isolated coarctation of the aorta and severe hypertension.

Short-term results are very satisfactory. All patients survived the operation, and all are asymptomatic. They have no detectable arm-leg pressure gradient by Dop- pler study.

The second technique also enlarges the end-to-end anastomosis and has the additional advantage of avoiding ligation of a major artery. We now prefer this option when the origin of the subclavian artery is fairly close to the coarctation.

Occasionally, a patient may be seen with unsuitable anatomy for either of these two techniques (e.g., a very small subclavian artery or a very long hypoplastic isth- mus). In such patients, we would use a coarctectomy combined with an end-to-end anastomosis posteriorly, enlarged anteriorly with a prosthetic patch, rather than patch angioplasty alone. In other words, we emphasize that in small infants, coarctectomy is an essential part of the procedure, and the aortic anastomosis should be en- larged by any modification described.

A long-term follow-up of several years is needed to help determine whether these techniques are advanta- geous or not.

References 1. Hesslein PS, Gutgesell HP, McNamara DG: Prognosis of

symptomatic coarctation of the aorta in infancy. Am J Car- diol 51:299, 1983

2. Kamau P, Miles V, Toews W, et al: Surgical repair of coarc- tation of the aorta in infants less than six months of age. J Thorac Cardiovasc Surg 81:171, 1981

3. Crafoord C, Nylin G: Congenital coarctation of the aorta and its surgical treatment. J Thorac Surg 14:347, 1945

4. Williams WG, Shindo G, Trusler GA, et al: Results of repair of coarctation of the aorta during infancy. J Thorac Cardio- vasc Surg 79:603, 1980

5. Fleming WH, Sarafian LB, Clark EB, et al: Critical aortic coarctation: patch aortoplasty in infants less than age 3 months. Am J Cardiol 44:687, 1979

6. Yee ES, Soifer S, Turley K, et al: Infant coarctation: a spec- trum in clinical presentation and treatment. Ann Thorac Surg 42:488, 1986

7. Waldhausen JA, Nahrwold DL: Repair of coarctation of the aorta with a subclavian flap. J Thorac Cardiovasc Surg 51:532, 1966

8. Bergdahl LAL, Blackstone EH, Kirklin JW, et al: Determi- nants of early success in repair of aortic coarctation in in- fants. J Thorac Cardiovasc Surg 83:736, 1982

9. Moulton AL, Brenner JI, Roberts G, et al: Subclavian flap repair of coarctation of the aorta in neonates: realization of growth potential? J Thorac Cardiovasc Surg 87:220, 1984

10. Penkoske PA, Williams WG, Olley PM, et al: Subclavian

11.

12.

13.

14.

15.

16.

arterioplasty: repair of coarctation of the aorta in the first year of life. J Thorac Cardiovasc Surg 872394, 1984 Cobanoglu A, Teply JF, Grunkemeier GL, et al: Coarctation of the aorta in patients younger than three months: a cri- tique of the subclavian flap operation. J Thorac Cardiovasc Surg 89:128, 1985 Pellegrino A, Deverall PB, Anderson RH, et al: Aortic co- arctation in the first three months of life: an anatomo- pathological study with respect to treatment. J Thorac Car- diovasc Surg 89:121, 1985 Harlan JL, Doty DB, Brandt B, Ehrenhaft JL: Coarctation of the aorta in infants. J Thorac Cardiovasc Surg 88:1012, 1984 Dietl CA, Torres AR, Cazzaniga M: Coarctectomy and anas- tomotic enlargement with subclavian artery. Rev Latina de Card Inf 1:207, 1985 [Span] Lodge FA, Lamberti JJ, Goodman AH, et al: Vascular conse- quences of subclavian artery transection for the treatment of congenital heart disease. J Thorac Cardiovasc Surg 86:18, 1983 Mendonca IT, Carvalho MR, Costa RK, Filho EF: Coarcta- tion of the aorta: a new surgical technique. J Thorac Car- diovasc Surg 90445, 1985