Surgical management of severe aortic coarctation and interrupted aortic arch in neonates

Surgical management of severe aortic coarctation and interrupted aortic arch in neonates Forty-four infants, 2 to 90 days of age, with severe obstructive lesions of the aortic arch, underwent emergency surgical correction between Jan. 1, 1966, and April 1, 1975. The typical clinical presentation was severe congestive heart failure and acidemia. Resection of an aortic coarctation with end-to-end anastomosis was performed in 31 patients. Eight (26 per cent) died after the operation. Since 1969, the mortality rate has been reduced to 14 per cent (3 of 22 patients) even though the incidence of major associated cardiac lesions has remained essentially constant (56 per cent from 1966 through 1969, 64 per cent from 1970 through March, 1975). This suggests that the higher survival rate has resulted from improved surgical techniques and postoperative care. The mortality rate in the infants operated upon during the second and third months of life was twice as high as that in those operated upon before the age of 1 month. Eight patients with Type A interrupted aortic arch were operated upon and 5 survived. Five patients with Type B aortic arch were operated upon and 3 survived.

Noel H. Fishman, M.D., Merrill H. Bronstein, M.D. (by invitation), William Berman, Jr., M.D. (by invitation), Benson B. Roe, M.D., L. Henry Edmunds, Jr., M.D., Saul J. Robinson, M.D. (by invitation), and Abraham M. Rudolph, M.D. (by invitation), San Francisco, Calif.

X revious reports cite a mortality rate of forty to sixty per cent after repair of aortic coarctation in the neonatal period.8, 15, 23, 25 The operative mortality rate for patients with interrupted aortic arch is even higher. 17,28 The high incidence of associated intracardiac lesions and the immaturity of the patients have been suggested as the factors responsible for the poor surgical results. We have reviewed the results of surgery in our institution to assess the factors which might be important in determining the outcome in these infants. Clinical material Between 1966 and 1975, 44 infants aged 2 to 90 days were diagnosed as having severe aortic coarctation, hypoplastic aortic arch, or interrupted aortic arch. Diagnosis was established by catheterization and angioFrom the Departments of Surgery and Pediatrics, University of California, San Francisco, Calif. 94143. Read at the Fifty-fifth Annual Meeting of The American Association for Thoracic Surgery, New York, N. Y., April 14, 15, and 16, 1975. Address for reprints: Noel H. Fishman, M.D., Department of Surgery, University of California, San Francisco, Calif. 94143.

cardiography, and emergency repair was attempted. Surgery was performed in all patients because of severe symptoms and poor response to medical management. The sex, age, associated cardiovascular malformations, and method of treatment are summarized in Tables I, II, and III. All patients presented with congestive heart failure and many with progressive acidemia. Typically, a variable period of neonatal well being was followed by feeding problems, tachypnea, and sweating. An inadequate systemic blood flow was evidenced by cool extremities, mottled skin, reduced urinary output, and, ultimately, acidemia. Pulses in the upper extremities were stronger than those in the legs but were seldom bounding. Differential cyanosis was not recognized in any of our patients. The precordium was often active, with right ventricular prominence. Tachypnea, tachycardia, and hepatomegaly were present in all patients. On auscultation, the first heart sound was normal; the second heart sound was narrowly split, with an accentuated pulmonic component. Apical gallop rhythms were common. A systolic ejection murmur was usually heard well over the precordium and back. 35

The Journal of Thoracic and Cardiovascular Surgery

3 6 Fishman et al.

Table I. Coarctation not associated with major cardiac lesions Case No.

Sex

Date of operation

Age at operation

Assoicated minor cardiac lesions

1

M

1968

4 days

-

2 3 4

F F M

1968 1969 1969

20 days 34 days 21 days

5 6 7 8 9 10 11 12

M M F F M M M F

1970 1971 1971 1973 1974 1974 1975 1975

52 days 66 days 8 days 27 days 10 days 10 days 8 days 9 days

Chest roentgenograms usually showed cardiomegaly and pulmonary venous congestion. The electrocardiograms of infants with coarctation or interrupted aortic arch showed right axis deviation and right ventricular hypertrophy. Left ventricular hypertrophy was not noted in any patient. Thirty-one patients had coarctation of the aorta. The location of the coarctation was juxtaductal in most cases, often including the entire isthmus. In 22 cases the aortic isthmus was narrow, and there was diffuse narrowing of the isthmus in 5 infants. Thirteen patients had interruption of the aortic arch. In 5 cases the interruption was between the left subclavian and left carotid arteries (Type B), 3 and in 8 cases it between the origin of the left subclavian artery and the descending aorta (Type A). 3 One case in which there was a segment of tubular hypoplasia 2 mm. in diameter internally and 3 cm. in length is included in this group (Fig. 1, D). Associated major cardiac anomalies were present in 19 patients with aortic coarctations (61 percent) (Table II) and in every patient who had an interrupted aortic arch (Table III). Operative repair Aortic coarctation. Each coarctation was resected and an end-to-end anastomosis was performed. Prior to 1969 the ductus arteriosus was divided between clamps and the pulmonary arterial side was oversewn before the aorta was clamped. The clamps were then applied to the aorta and the coarctation was completely excised. A continuous suture was used posteriorly and interrupted sutures anteriorly. We now ligate the ductus arteriosus just before clamping and transecting the

-

Bicuspid aortic valve Bicuspid aortic valve, mild aortic stenosis

-

Bicuspid aortic vlave

-

Left to right atrial shunt Left to right atrial shunt Left to right atrial shunt

-

Results Died 11 days postop.; intercurrent Pseudomonas sepsis Survived Survived Died in operating room Survived Survived Survived Survived Survived Survived Survived Survived

aorta. The aortic anastomosis is now usually performed entirely with interrupted sutures. Because the aortic isthmus was narrow or hypoplastic, the anastomosis was performed at the base of the transverse arch at the origin of the left subclavian artery in 27 of the 31 cases. Pulmonary artery banding was performed in only 3 of the 13 patients who had a ventricular septal defect. Interrupted aortic arch (Table III, Figs. 1 and 2). In the Type A interrupted aortic arch, direct aortic anastomosis between the transverse arch and descending aorta was performed in 2 cases (Fig. 1, A and B). An end-to-side anastomosis between the left subclavian artery and the descending aorta (Blalock-Park shunt) was used in 4 cases (Fig. 1, C). An end-to-end anastomosis between the left subclavian artery and the descending aorta was used in one case (Fig. 1, D). In one patient the left subclavian artery was transected distally, opened lengthwise along its lateral margin, and used as a pedicle onlay patch graft to enlarge the elongated tubular hypoplastic isthmus (Fig. 1, E). Each Type B interrupted arch was treated in an individual manner (Fig. 2). In one instance the left carotid and subclavian arteries were joined end to end (Fig. 2, A). In another case the left subclavian artery was swung forward and anastomosed to the base of the aorta at the origin of the left carotid artery (Fig. 2, C). Complete one-stage correction of an interrupted arch and the associated ventricular and atrial septal defects was attempted in one case (Fig. 2, B). In one 3-day-old patient who had a Type B interrupted arch and ventricular septal defect, the position of the descending aorta was very low and the left subclavian artery was small in diameter and stenotic at its origin (Fig. 2, D). The left carotid artery

Volume 71 Number 1 January, 1976

Severe aortic coarctation and interrupted aortic arch

37

Table II. Coarctation in association with major cardiac lesions Case No.

Sex

Date of operation

Age at operation

I 2 3 4 5 6 7 8 9 10 II

M M M M M M F M M M F

1966 1967 1967 1969 1969 1970 1970 1970 1970 1971 1971

5 wk. 3 days 7 wk. 8 days 41 days 16 days 81 days 36 days 68 days 45 days 34 days

Subvalvar AS TGA, VSD VSD VSD (PFO), no PDA VSD (PFO) Subvalvar AS, valvular AS VSD (PFO) VSD VSD, increased PVR VSD, (PDA) Myocardopathy, subvalvar AS

12 13 14

M M M

1971 1972 1972

10 days 90 days 34 days

15 16 17 18 19

M M M M F

1973 1973 1973 1975 1975

42 days 10 days 17 days 10 days 3 days

VSD VSD, increased PVR, SEFE Mild AS, small mitral valve (ASD) Mild AS, increased PVR AS, SEFE, increased PVR TGA, single ventricle, ASD Single ventricle Mitral atresia, single ventricle

Associated major cardiac lesions

Results Died in operating room Survived Died in operating room Survived Died 2 days postop., renal failure Survived Survived Survived Died in operating room Died 9 days postop., renal failure Died 27 days postop. progressive LV failure Survived Survived Survived Survived Survived Survived Survived Died 8 hr. postop.

Legend: AS. Aortic stenosis. TGA. Transposition of the great arteries. VSD. Ventricular septal defect. PFO, Patent foramen ovale. PDA, Patent duclus arteriosus. PVR. Pulmonary vascular resistance. SEFE. Subendocardial fibroelastosis. ASD, Atrial septal defect. LV, Left ventricular.

Table III. Interrupted aortic arch Case No.

Sex

Date

Age at operation

Type

1 2 3

M M M

1969 1969 1970

5 days 4 days 2 days

A A B

VSD VSD, ASD, TGA VSD, ASD

4

F

1970

3 days

B

VSD, anomalous RSC

5 6 7

M F M

1970 1970 1971

6 wk. 3 wk. 2 days

A A A

8

F

1972

13 days

A

VSD, TGA (or DORV) DORV (or T-B), ASD Truncus, Type I, VSD, ASD, TI VSD, ASD

9

F

1972

9 days

B

VSD, ASD

10

F

1973

2 days

B

VSD, mitral regurgitation

II

M

1974

6 days

A

VSD, subvalvular AS

12

M

1974

36 days

A

13

F

1975

5 days

B

Tricuspid atresia, single ventricle, L transposition VSD, anomalous RSC

Associated lesions

Results

Repair B/P, PA band B/P, PA band End-to-end LCA to LSC anastomosis LSC to base of LCA (end-to-side), bilateral PA bands B/P, bilateral PA bands B/P, PA band Side-to-side aortic anastomosis, PA band End-to-end LSC to aorta, PA band End-to-end aortic anastomosis, closure VSD and ASD on CPBP End-to-end LCA to descending aorta (VSD repaired at 6 mo.) End-to-end aortic anastomosis, PA band Pedicled LSC onlay graft, PA band Formalin injection PDA, bilateral PA bands

Died 1 day postop. Survived Died 1 day postop. Survived Survived Died in operating room Died in operating room Survived Died in operating room Survived Survived Survived Survived

Legend: RSC, Right subcluvian artery. DORV, Double-outlet right ventricle. T-B. Taussig-Bing anomaly. TI, Tricuspid insufficiency. B/P, Blalock-Park end-to-side left subclavian artery—descending aorta anastomosis. PA, Pulmonary artery. LCA. Left carotid artery. LSC. Left subclavian artery. CPBP. Cardiopulmonary bypass. For other abbreviations, see Table II.

38

The Journal of Thoracic and Cardiovascular Surgery

Fishman et al.

A.

Direct a n a s t o m o s i s , side c l a m p t e c h n i q u e , 1 case. RSC

RCA

^Jl /T /) s c

^Jl //A JT

%]

LSC Ductui ligaled

PA Band B. D i r e c t a n a s t o m o s i s , o p e n t e c h n i q u e , 1 c a s e . RSC. RCA

LCA

f

Hypoplastic \ \ I arch \ ^ * Ligament

PA Band C. E n d to s i d e - l e f t s u b c l a v i a n a r t e r y

to d e s c e n d i n g

oorta, 4

coses.

RSCV RCA

LSC

PA Band

Fig. 1. Type A interrupted aortic arch, operative repair, 8 cases. A, Direct anastomosis between proximal and distal aortic segments with the use of side clamps; 1 case. B, Direct anastomosis between aortic segments with the use of an essentially open technique for more accurate placement of sutures (see text); I case. C, End-to-side anastomosis between the left subclavian artery and descending aorta with the use of an aortic side clamp; 4 cases. RSC, Right subclavian artery. RCA, Right carotid artery. LCA, Left carotid artery. LSC, Left subclavian artery. Ao, Aorta. VSD, Ventricular septal defect. PTr, Pulmonary trunk. LPA, Left pulmonary artery. DA, Ductus arteriosus. Desc Ao, Descending aorta. PA, Pulmonary artery. was relatively large, and an end-to-end anastomosis between the left carotid artery and descending aorta was easily achieved. Because of persistent congestive heart failure and failure to thrive, cardiac catheterization and cineangiography were repeated 3 months later to rule out anastomotic narrowing. The carotid artery and anastomosis had increased considerably in size, resembling a normal arch, but there was a large left-to-right shunt at the ventricular level. A large ventricular defect was closed electively with a Teflon patch at 6 months of age, after which the patient did very well.

In another case, a 2-day-old patient who presented with severe congestive heart failure and acidosis was found at catheterization to have a large ventricular septal defect, a moderately hypoplastic aortic valve annulus and ascending aorta, and a Type B interrupted aortic arch (Fig. 2, E). Both subclavian arteries arose from the descending aorta and were narrow. The left subclavian artery was stenotic at its origin from the aorta. The vertebral arteries were not visualized, and we thought that anastomosis of the left carotid artery to the descending aorta in this case might result in severe neurologic complications. Therefore, we elected to infil-

Volume 71 Number 1 January, 1976

Severe aortic coarctation and interrupted aortic arch

39

D. End to end - left subclavian artery to descending a o r t a , 1 c a s e . RSC.

RCA

LCA

PA Band

E. Pedicled o n l a y RS

V|

CA

LCA

graft , 1 case

asc

PA Band

Fig. 1. Cont'd. D, End-to-end anastomosis between the left subclavian artery and descending aorta; 1 case. £, Pedicle onlay graft; 1 case. Incision along lateral margin of left subclavian artery carried down through very long, diffusely narrowed aortic isthmus on to descending aorta. The artery was then turned downward and used as a gusset to enlarge the hypoplastic isthmus.

trate 10 per cent formalin into the subadventitial plane of the ductus arteriosus to prevent further constriction of the ductus.19 Pulmonary artery banding, either of the pulmonary trunk or individual main pulmonary arteries, was carried out in 10 of the 13 patients with interrupted aortic arch, and closure of the ventricular septal defect was performed (as mentioned) in 2 other cases. Results Aortic coarctation. The mortality rate after operative repair of aortic coarctation in the neonatal period was 26 per cent (8 of 31) for the entire period covered by this report (Fig. 3). Prior to December, 1969, the operative mortality rate was 57 per cent (5 of 9). Since 1969 the mortality rate has decreased to 14 per cent (3 of 22), and there has been only one death in the last 13 patients who were operated upon. Six of the eight deaths occurred in the operating room or during the early postoperative period. The other two deaths occurred 11 and 27 days after surgery and were not related to operative complications. The incidence of associated major intracardiac lesions was 57 per cent (5 of 9) in the earlier part of the

series and 64 per cent (14 of 22) in the patients operated upon since 1969 (Fig. 3). Six of the 8 patients who died had major associated cardiac lesions. The relationship between operative mortality rate and associated major cardiac lesions was not statistically significant by chi-square analysis. The mean age at operation during the past 3 years has been 8 days, whereas the mean age at operation for the entire series is 25 days. The operative mortality rate for patients operated upon during the first month of life was 18 per cent (3 of 17) compared to 36 per cent (5 of 14) for the remainder who were in their second and third months of life at the time of surgery (Fig. 4). Stenosis is known to have recurred within 1 year after repair of aortic coarctation in 6 patients. Two of them underwent repair of recurrent coarctation at the institution. One patient had a stenosis above and the other had one below the actual anastomosis. The anastomosis was not constricted in either case. In one of these patients the stenosis definitely occurred where the proximal aortic clamp had been applied during the first operation. Interrupted aortic arch. The operative mortality rate was 38 per cent (3 of 8) in patients with Type A

40

The Journal of

Fishman el al.

Thoracic and Cardiovascular Surgery

A. End to end - left carotid to subclavian artery, 1 case. RSC RCA

LCA ISC Ductus ligated PA Band

B. End to side - descending aorta to ascending aorta, VSD repair (cardiopulmonary bypass), 1 case. RSCA^CA

LCA

LCA

//

>sc

ISC ctus ligated d transected

VSD Patch - £ * - „

4f

C. End to side - left subclavian artery to ascending a o r t a , 1 case. RSC

RCA

LCA

LCA LSC

Ductus constricting, not ligated

Bilateral PA Banding

Fig. 2. Type B interrupted aortic arch, operative repair; 5 cases. A, End-to-end anastomosis between the left carotid and subclavian arteries; 1 case. B, One-stage correction of arch and intracardiac anomalies with the aid of cardiopulmonary bypass, profound hypothermia and circulatory arrest; 1 case. C, End-to-side anastomosis between the left subclavian artery and ascending aorta; 1 case. For abbreviations see Fig. I. and 40 per cent (2 of 5) in patients with Type B interrupted aortic arches (Fig. 5). Since January, 1971, 6 patients, 3 with Type A and 3 with Type B arch interruptions, have been operated upon with only one death (17 per cent mortality rate). Two of the deaths following repair of Type A interrupted aortic arch occurred postoperatively and were related to technical problems at surgery. Both occurred in patients in whom the left subclavian artery was turned down and anastomosed to the side of the descending aorta (Fig. 1, B). In the first case, the subclavian artery thrombosed; in the second, hemorrhage occurred through the pulmonary arterial end of a ductus that had been divided and oversewn. The third

death in this group of patients occurred in the operating room. The patient sustained a cardiac arrest during anesthetic induction and, although resuscitated, died after what appeared to be a technically satisfactory repair. Myocardial necrosis and fibrosis were found at autopsy. In the series of patients with Type B interrupted aortic arch, there were two deaths. In one case (Fig. 2, A) the left carotid and subclavian arteries were sewn end to end, but adequate perfusion to the lower body was never established. The other infant (Fig. 2, B), who underwent complete correction of the interrupted arch and ventricular and atrial septal defects on cardiopulmonary bypass, died in the operating room.

Volume 71 Number 1 January, 1976

Severe aortic coarctation and interrupted aortic arch

41

P. End to e n d , left carotid artery to descending a o r t a , 1 case. RSC RCA ICA

RCA LSC Ductus ligated

/ W { VSD ,

LPA

^Y

VSD De,c

Ao

r\

patched ■—__/;,»—. / ] at s e c o n d ! ? * >J operation Mk <,%£

E. Injection of formalin in subadventitial plane of ductus a n d bilateral PA b a n d i n g , 1 case. RCA

Hypoplastic ascending aorta—i

LCA

LSC

LSC Infiltration o l ductus with formalin.

Formalin infiltration

Hypoplastic annukis Bilateral

PA Banding

Fig. 2. Cont'd. D, Two-stage correction of arch and intracardiac anomalies. End-to-end anastomosis between the left carotid artery and descending aorta. Ventricular septal defect repaired at 6 months of age with the aid of cardiopulmonary bypass. E, Injection of 10 per cent formalin in subadventitial plane of ductus arteriosus to inhibit postnatal constriction of the ductus.19 For abbreviations see Fig. 1. At autopsy the ascending aorta was found to be narrowed significantly at the site of aortic cannulation. Stenosis of the aorta recurred in one patient (Fig. 1, E) after repair of a Type A interrupted aortic arch, but the lesion has not yet required repair. Discussion Clinical features. Infants with severe aortic coarctation or interrupted arch appear normal at birth, but after a variable period they develop signs and symptoms of congestive heart failure. The development of cardiorespiratory distress is often more rapid in patients with complete interruption of the arch than in those with aortic coarctation; postnatal closure of the ductus arteriosus may contribute to the development of symptoms.20 During fetal life, the ductus conducts most of the right ventricular output to the descending aorta, where it provides the bulk of aortic flow to the placenta and lower body. The aortic isthmus carries only 10 per cent of the combined ventricular output to the descending thoracic aorta18 (Fig. 6). Because a juxtaductal coarctation or preductal arch interruption has a minor impact on fetal cardiovascular dynamics, there is little stimulus to the development of collateral circulation. The ductus remains open for a variable

period after birth. As long as it remains widely patent the infant may be asymptomatic, and the presence of an obstructive aortic lesion may not be detected. With the fall in pulmonary vascular resistance that occurs after birth, pulmonary blood flow increases and flow through the ductus decreases. When the ductus begins to constrict, narrowing occurs first at its pulmonary attachment20 (Fig. 7). The aortic isthmus, if present, then carries a much greater volume of blood to the descending thoracic aorta. If the ductus remains patent at the aortic end, a relatively unobstructed path may exist for blood to flow around the coarcted segment (Fig. 7, A). However, when ductal constriction progresses to the aortic pole, the anatomic obstruction worsens, left ventricular afterload increases, and systemic output decreases. If left atrial pressure rises and pulmonary hypertension develops, right ventricular afterload increases and biventricular failure supervenes. In patients with interruption of the aortic arch (Fig. 7, B), ductal constriction at the pulmonary pole alone interferes abruptly with flow to the descending aorta and accounts in part for the earlier age at which symptoms occur. Ductal closure should be recognized as the precipitating hemodynamic event in infants with aortic

The Journal of Thoracic and Cardiovascular Surgery

4 2 Fishman et al.

Associated Major Cardiac Lesions

61%

56%

64%

Mortality

26%

56%

14%

Survived Died in Hospital

1966-1975

1966-1969

1970-1975

Fig. 3. Aortic coarctation in neonates. Results of surgery and correlation of results with incidence of associated major intracardiac lesions. coarctation or arch interruption who develop congestive heart failure in the first months of life. Because ductal constriction has been related experimentally to an increasing arterial Po 2 , n ' 16 oxygen therapy may be harmful to this group of patients. Although acidemia and congestive heart failure may be dramatic, hypoxemia is rarely part of the clinical presentation of neonates with severe aortic obstructive lesions. It is our practice, therefore, to maintain the infants in room air. Since atropine has been shown experimentally to decrease the constrictive effect of oxygen on the ductus,11, 16 we administered it intravenously in a dose of 0.01 mg. per kilogram in an effort to forestall closure of the ductus until surgery can be performed. However, we are not sure atropine has the same effect on the ductal tissue of humans as has been demonstrated in fetal lambs. Medical management alone is rarely effective in patients with severe aortic coarctation in the neonatal period.7 Of 34 patients with thoracic aortic coarctation who were referred to us in the first 3 months of life in whom intensive medical therapy was attempted, only 3 were successfully managed without surgical repair. Therefore, we recommend early operation for those infants who do not respond promptly to digitalis and diuretic therapy. The effective surgical management of aortic coarctation and arch interruption in neonates must include an appreciation of the importance of the ductus arteriosus. Flow to the lower body is markedly interfered with (or halted altogether in the case of an interrupted arch) the moment the ductus is clamped. Therefore, we ab-

breviate the time period over which flow to the lower body is obstructed by simply ligating the ductus, rather than dividing and oversewing it, just before applying the aortic clamps. Before we adopted this principle, 2 patients with coarctation had cardiac arrest during the period of aortic cross-clamping and 2 others died postoperatively of renal complications from prolonged ischemia to the lower body. In addition, one patient bled excessively from the suture line in the pulmonary arterial side of a ductus that had been divided between clamps and oversewn prior to reconstruction of the aorta. Tawes and associates25 reported a 58 per cent operative mortality rate (71 of 123) in patients operated upon for coarctation during the first 3 months of life. They attributed the high mortality rate to the effects of associated cardiovascular lesions which were present in 67 per cent of their patients. Our experience does not support their conclusions. The perioperative mortality rate in our series has steadily decreased, to 14 per cent since 1969 and to one death in the last 13 cases, while the incidence of complex lesions (61 per cent) has remained essentially unchanged over the period of this report (Fig. 5). A progressive decline with age in the operative mortality rate in aortic coarctation in neonates has been reported. 5,23,25 In our series the perioperative mortality rate was actually lower in the first month (18 per cent) than in the next 2 months of life (36 per cent) (Fig. 6). It may be that infants who have been chronically ill with congestive failure for several weeks tolerate

Volume 71

Severe aortic coarctation and interrupted aortic arch

Number 1

43

January, 1976

Mortality

40%

18%

25%

20-

Survived Died in Hospital

Number of

10-

Patients

0

1

2

3

Age at O p e r a t i o n

(months)

Fig. 4. Aortic coarctation in neonates. Results of surgery correlated with age of patient at time of surgery. Survived D i e d in H o s p i t a l 60%

1969 thru 1975

50%

1969 thru 1971

0%

33%

1972 t h r u 1975

Fig. 5. Interrupted aortic arch in neonates. Results of surgery. coarctation repair less well than younger infants who are seriously ill for a shorter period. There is evidence that long-standing systemic hypertension leads to rapid development of myocardial necrosis and fibrosis in young infants.4 Significant recurrent obstruction of the aorta was recognized in 19 per cent of our cases. In reviewing our experience we made two observations that might be helpful in understanding this complication. It is known that the size of the aortic arch is determined by the flow through it.6 The smaller the vessel's diameter, the more likely is stricture to develop. In 90 per cent of the patients with aortic coarctation in this series, a hypoplastic transverse arch of the same size as the left subclavian artery was described in the operative report, suggesting that the arch had been carrying only subclavian flow during fetal life. The other observation was that the constriction may occur where the vascular clamps were applied during repair of the coarctation.

Intimal damage has been shown to occur at the site of aortic clamping in other situations. It is possible that intimal necrosis may lead to narrowing of the small neonatal aorta during the healing process. Without surgery, the mortality rate from the presence of an interrupted aortic arch in the neonatal period is over 90 per cent.12, 28 Until recently, however, the survival rate was not measurably increased by attempts at surgical correction. Up to the present time only 9 cases in which arch interruption has been treated successfully by surgery in the first 3 months of life have been reported.1- 9- 13- 14- "■ 22- 26 " 28 This present report adds an additional 8 cases to that total. The over-all surgical mortality rate, 39 per cent in this series, and the reduction to one death in the last 6 cases (17 per cent mortality) are encouraging. Interruption of the aortic arch is a much more difficult technical problem than coarctation of the aorta, because the distance between the proximal and

The Journal of

4 4 Fishman et al.

Thoracic and Cardiovascular Surgery

RCA

LCA

SVC

IVC Normol fetal circulotion

IVC Fetal circulation in interrupted aortic arch

Fig. 6. Fetal circulation. Patterns of distribution of bloodflowbased on experimental data.18 Encircled numbers indicate percentage of total cardiac outputflowingthrough labeled cardiac chamber or blood vessel. A, Normal fetal lamb.18 Note that only 10 per cent of cardiac output traverses aortic isthmus. B, Fetal circulation with interrupted aortic arch. Left ventricular output contributes nothing to lower body flow, but flow into the descending aorta is little affected. Formation of aortic collaterals is not stimulated. RA, Right atrium. RV, Right ventricle. LA, Left atrium. LV, Left ventricle. SVC, Superior vena cava. IVC, Inferior vena cava. For other abbreviations see Fig. 1. distal aortic segments is usually too great for direct anastomosis. The Type A arch interruption is easier to treat surgically than Type B. The anatomy of Type A interruption resembles that of a very severe coarctation, except that the distance between the aortic arch and the descending aorta is much greater. Surgical techniques for dealing with this problem have been available since 1944.2 The left subclavian artery is often of sufficient length to turn downward to meet the descending aorta, and the lumen is usually equal to that of the arch between the left carotid and subclavian arteries. However, only 6 cases have been reported in which a Type A interrupted arch has been successfully treated surgically in the neonatal period.13, 21, 22, 27' 28 This reports adds 5 cases of Type A interruption which were successfully managed surgically, 3 of which were managed with left subclavian-aortic anastomosis. The major difficulty in performing a subclavianaortic shunt is the technical problem of performing an end-to-side shunt within the confines of a partially occluding aortic clamp. Because ductal flow is so obviously essential when the arch is completely interrupted, we formerly believed these infants would not tolerate ductal clampling for the period required to perform such a shunt. In order to preserve flow to the lower body through the ductus during the anastomosis, we applied a side-biting aortic clamp shallowly across the descending aorta, which itself is a very small

structure in neonates. The result was all too often an imperfect anastomosis through which flow was inadequate. We attempted four end-to-side and one side-to-side subclavian-aortic anastomoses within partially occluding clamps and were successful only twice. In the other 3 cases of Type A interruption in which we were successful, the ductus was ligated and an open anastomosis was performed: end-to-end subclavianaortic anastomosis in one, end-to-end aorto-aortic anastomosis in another, and left subclavian pedicle onlay patch graft in the third patient. We discovered that open reconstruction with interrupted sutures can be performed as rapidly (15 to 20 minutes) and as safely in this anomaly as in neonatal coarctation in which the ductus is equally important functionally. Type B interruptions present a greater technical challenge. Only 3 cases in which this anomaly was treated successfully have previously been reported1, 14, 26 ; we now add 3 additional cases from our experience. In type B interruptions the left subclavian artery which arises from the descending aorta is often smaller than normal and frequently is stenotic at it origin. Also, the right subclavian artery often has an abnormal origin from the descending aorta. The ascending aorta is narrow in Type B interruption, especially when it carries only carotid arterial flow. Although in one instance we were able to successfully anastomose the left subclavian artery to the ascending aorta at the base

Volume 71

Severe aortic coarctation and interrupted aortic arch

Number 1 January, 1976

A.

45

Coarctation LSC

-ischemic

Constriction at pulmonary pole

B.

Complete ductal constriction

Interrupted arch LCA

LCA LSC

LSC Ascending aorta often hypoplastic

ische

Constriction

at pulmonary

pole

Fig. 7. Importance of postnatal constriction of the ductus arteriosus on development of symptoms in neonates with obstructive lesions of the aortic arch. A, Coarctation. Flow through the aortic isthmus continues even after the ductus begins to constrict at the pulmonary pole;flowto the lower body is reduced when constriction of the ductus progresses toward the aorta.20 B, Interrupted aortic arch. Constriction of the ductus at the pulmonary pole immediately interferes with flow to the lower body. For abbreviations see Fig. 1. of the left carotid artery (Fig. 2, C), it is usually impossible in the neonate to perform a satisfactory anastomosis on the ascending aorta within a partial exclusion clamp. When both subclavian arteries originate from the descending aorta, the use of clamps requires temporary interruption of flow through at least one of the carotid arteries proximally amd both subclavian arteries distally; the risk of neurological damage is high. In one such case, Van Praagh and associates28 inserted a Teflon graft between the pulmonary trunk and descending aorta and thus preserved flow to the lower part of the body. The pulmonary arteries were banded separately. We achieved the same result by injecting formalin within the subadventitial plane of the ductus arteriosus19 in one of our cases to arrest the constriction which normally occurs shortly after birth, and we banded the pulmonary arteries separately (Fig. 2, E). The ideal management of an interrupted aortic arch consists of one-stage correction of the arch anomaly and the associated cardiac defects. This is now possible

with the use of cardiopulmonary bypass, profound hypothermia, and circulatory arrest, provided that aortic arch reconstruction can be performed without the use of prosthetic material or homografts. A direct anastomosis between aortic segments or between the aorta and one of its major brachiocephalic vessels is more likely than reconstruction of the arch with prosthetic material or vascular homograft to result in a satisfactory lumen over the long term, because there is a chance for the channel to increase in size with growth.24 In one of our cases we accomplished total correction in two stages (Fig. 2, D). The arch was first reconstructed by end-to-end anastomosis between the left carotid artery and the descending aorta; a ventricular septal defect was closed electively 6 months later. Both the carotid artery and the anastomosis have grown subsequently and, on cineangiography, closely resemble a normal aortic arch in contour and size. This is the fourth reported case of a patient with an interrupted aortic arch to have complete correction of both the arch and intracardiac anomalies within the first year of life.

46

Fishman et al.

This is the second reported case of complete correction in which the arch was reconstructed without using a homograft or prosthetic material. Whether one-stage repair or staged correction of the arch and intracardiac lesions is preferable remains to be shown by experience in a large number of cases. Use of the carotid artery might be cause for concern. Ligation of one carotid artery has been shown to produce neurologic deficits in more than 25 per cent of patients in the older age groups, 1 0 but not in neonates. Flow through both the ipsilateral carotid and vertebral arteries has been sacrificed in 3 cases of Type A interruption in neonates without neurologic complications. 12, 20 Summary Aortic coarctation and arch interruption can be repaired in the first 3 months of life. Attention to surgical details and understanding the physiology of the lesions are crucial for success. We gratefully acknowledge the assistance of Ms. Beverly Hill, who helped to prepare the manuscript for publication, and the contributions of Dr. Paul A. Ebert, who operated upon 2 of the patients with aortic coarctation. REFERENCES 1 Barratt-Boyes, B. G., Nicholls, T. T., Brandt, P. W. T., and Neutze, J. M.: Aortic Arch Interruption Associated With Patent Ductus Arteriosus, Ventricular Septal Defect, and Total Anomalous Pulmonary Venous Connection, J. THORAC. CARDIOVASC. SURG. 63: 367, 1972.

2 Blalock, A., and Park, E. A.: The Surgical Treatment of Experimental Coarctation (Atresia) of the Aorta, Ann. Surg. 119: 445, 1944. 3 Celoria, G. C , and Patton, R. B.: Congenital Absence of the Aortic Arch, Am. Heart J. 58: 407, 1959. 4 Esterly, J. R., and Oppenheimer, E. A.: Some Aspects of Cardiac Pathology in Infancy and Childhood. IV. Myocardial and Coronary Lesions in Cardiac Malformations, Pediatrics 39: 896, 1967. 5 Hallman, G. L., and Cooley, D. A.: Cardiovascular Surgery in Newborn Infants: Results in 1,050 Patients Less Than One-Year Old, Ann. Surg. 173: 1007, 1971. 6 Heymann, M. A., and Rudolph, A. M.: Effects of Congenital Heart Disease on Fetal and Neonatal Circulations, Progr. Cardiovasc. Dis. 15: 115, 1972. 7 Kilman, J. W., Williams, T. E., Jr., Breza, T. S., Craenen, J., and Hosier, D. M.: Reversal of Infant Mortality by Early Surgical Correction of Coarctation of the Aorta, Arch. Surg. 105: 865, 1972. 8 Lindesmith, G. G., Stanton, R. E., Stiles, Q. R., Meyer, B. W., and Jones, J. C : Coarctation of the Thoracic Aorta, Ann. Thorac. Surg. 11: 482, 1971. 9 Losman, J. G., Joffe, H. S., Beck, W., and Barnard, C : Successful Total Repair of Interrupted Aortic Arch Associated With Ventricular Septal Defect and Large

The Journal of Thoracic and Cardiovascular Surgery

Patent Ductus Arteriosus, Am. J. Cardiol. 33: 566, 1974. 10 Moore, O., and Baker, H. W.: Carotid Artery Ligation in Surgery of the Head and Neck, Cancer 8: 712, 1955. 11 McMurphy, D. M., Heymann, M. A., Rudolph, A. M., and Melmon, K. L.: Developmental Changes in Constriction of the Ductus Arteriosus: Responses to Oxygen and Vasoactive Agents in the Isolated Ductus Arteriosus of the Fetal Lamb, Pediatr. Res. 6: 231, 1972. 12 Moller, J. H., and Edwards, J. E.: Interruption of Aortic Arch: Anatomic Patterns and Associated Cardiac Malformations, Am. J. Roentgenol. Radium Ther. Nucl. Med. 95: 557, 1965. 13 Murphy, D. A., Collins, G., and Dobell, A. R. C : Surgical Correction of Type A Congenital Aortic Arch Interruption, Ann. Thorac. Surg. 11: 593, 1971. 14 Murphy, D. A., Lemire, G. G., Tessler, I., and Dunn, G. L.: Correction of Type B Aortic Arch Interruption With Ventricular and Atrial Septal Defects in a Three-Day-Old Infant, J. THORAC. CARDIOVASC. SURG. 65: 882, 1973.

15 Mustard, W. T., Bedarb, P., and Trusler, G. A.: Cardiovascular Surgery in the First Year of Life, J. THORAC. CARDIOVASC. SURG. 59: 761, 1970.

16 Oberhansli-Weiss, I., Heymann, M. A., Rudolph, A. M., and Melmon, K. L.: The Pattern and Mechanisms of Response to Oxygen by the Ductus Arteriosus and Umbilical Artery, Pediatr. Res. 6: 693, 1972. 17 Rochette, M., Stanley, P., F.-Ethier, M., and Davignon. A.: Complete Interruption of the Aortic Arch in Infancy, Can. Med. Assoc. J. 98: 131, 1968. 18 Rudolph, A. M., and Heymann, M. A.: Fetal and Neonatal Circulation and Respiration, Ann. Rev. Physiol. 36: 187, 1974. 19 Rudolph, A. M., Heymann, M. A., Fishman, N. H., and Lakier, J. B.: Formalin Infiltration of the Ductus Arteriosus: A New Method for Palliation of Infants With Selected Congenital Cardiac Lesions, New Engl. J. Med. 292: 1263, 1975. 20 Rudolph, A. M., Heymann, M. A., and Spitznas, U.: Hemodynamic Considerations in the Development of Narrowing of the Aorta, Am. J. Cardiol. 30: 514, 1972. 21 Sirak, H. D., Ressallat, M., Hosier, D. M., and deLorimier, A. A.: A New Operation for Repairing Aortic Arch Atresia in Infancy. Circulation 37: 43, 1968 (Suppl. II). 22 Sissmann, N. J.: Anomalies of the Aortic Arch Complex, in Moss, A. J. and Adams, F. H., editors: Heart Disease in Infants, Children, and Adolescents, Baltimore, 1968, The Williams & Wilkins Company, pp. 418-419. 23 Stark, J., Hucin, B., Aberdeen, E., and Waterston, D. J.: Cardiac Surgery in the First Year of Life: Experience With 1,049 Operations, Surgery 69: 483, 1971. 24 Tawes, R. L., Jr., Aberdeen, E., and Berry, C. L.: The Growth of an Aortic Anastomosis: An Experimental Study in Piglets, Surgery 64: 1122, 1968. 25 Tawes, R. L., Jr., Aberdeen, E., Waterston, D. J., and Bonham-Carter, R. E.: Coarctation of the Aorta in Infants and Children: A Review of 333 Operative Cases,

Volume 71 Number 1 January, 1976

Severe aortic coarctation and interrupted aortic arch

Including 179 Infants, Circulation 39, 40: 173, 1969 (Suppl. I). 26 Trusler, G. A., and Izukawa, T.: Interrupted Aortic Arch and Ventricular Septal Defect: Direct Repair Through a Median Sternotomy Incision in a 13-Day-Old Infant, J. THORAC. CARDIOVASC. SURG. 69: 126,

1975.

27 Tyson, K. R. T., Harris, L. C , and Nghiem, Q. X.: Repair of Aortic Arch Interruption in the Neonate, Surgery 67: 1006, 1970. 28 Van Praagh, R., Bernhard, W. F., Rosenthal, A., Parisi, L. F., and Fyler, D. C : Interrupted Aortic Arch: Surgical Treatment, Am. J. Cardiol. 27: 200, 1971. Discussion D R . A N T H O N Y R. C .

DOBELL

Montreal. Quebec. Canada

I would like to make a simple observation that is pertinent to aortic arch interruption based on our own experience, which is not as good as that reported by Dr. Fishman here today. The observation is that the prognosis depends on the size of the conduit that is constructed. Our survivors have been treated in one of two ways. In some, we have reconstructed the aorta with a homograft or fabric graft. Other patients have had a double innominate arterial tree, and we have turned down the left innominate artery, ligating the carotid and subclavian on that side. Reconstruction by bridging the interruption with a carotid or subclavian artery alone has not been satisfactory in our hands. We have found it easy to fool ourselves using magnifying glasses. However, these arteries are usually 2 mm. in diameter, and we believe the conduit should measure 4 mm. In our experience there has been no relationship to whether or not intracardiac repair has been carried out at the same time. I think the most important feature is the conduit. 1 would like to ask the authors if they have had any experience with renal problems postoperatively following repair of the aortic arch interruption, because we have. DR. R O N A L D J .

NELSON

Torrance, Calif.

I too would like to compliment the authors on their very fine presentation and results. My comments are directed toward the very challenging group of infants who have interruption of the aortic arch associated with complex intracardiac defects. Success in managing this group of infants has been elusive whether an initial palliative or definitive approach has been used. The choice of an early palliative approach with later correction versus an immediate definitive correction, often with the assistance of profound hypothermia, depends upon several factors: (1) the availability of a satisfactory palliative or corrective procedure, (2) the experience of the surgical team, and (3) the results of accumulating experience. Since few cases of either approach have been reported, I would like to present a follow-up of one of the infants in this well managed series. The infant was in very severe congestive heart failure due to a Type A interrupted aortic

47

arch in association with transposition of the great vessels, ventricular septal defect, and a patent ductus arteriosus. At 4 days of age, he underwent successful turndown of the left subclavian artery to the descending aorta, ligation of the patent ductus arteriosus and banding of the pulmonary artery, performed by Dr. Edmunds. At 3 years of age he suffered a right middle cerebral artery occlusion. Subsequently, the family moved to the Los Angeles area. Because of growth retardation and increasing cyanosis, he was restudied at 4 years of age. An aortogram was taken to visualize the turndown of the left subclavian artery to the descending thoracic aorta. In this case, the procedure provided a very satisfactory aortic arch for this 4-year-old child. The arch appeared to have grown with the patient and had no significant gradient across it. A left anterior oblique projection of a pulmonary ventriculogram revealed the tight pulmonary artery band with shunting across the ventricular septal defect into the anteriorly placed systemic ventricle and aorta. Following the study at age 4, he underwent correction of the transposition with an interatrial baffle of pericardium, closure of the ventricular septal defect through the tricuspid valve, and release of the pulmonary artery band with placement of a tube graft patch. At follow-up 1 year later he was doing well. This case illustrates one of the problems as well as the potential of early palliation followed by later correction in selected cases. DR. F R E D E R I C K O.

BOWMAN

New York. N. Y.

Let me also add my congratulations to the authors for their fine results and their excellent presentation. I rise to discuss the problem of interrupted aortic arch Type B with patent ductus arteriosus and ventricular septal defect, and I would like to advocate the approach that Dr. George Trusler has recently reported in our JOURNAL. This is an approach of total repair as the first operation, done with deep hypothermia and circulatory arrest. During the past year, I have had the opportunity of operating upon 3 patients with the Type B interrupted arch. By means of the technique Dr. Trusler described of deep hypothermia and total arrest, and via a median sternotomy, it has been quite feasible to perform an anastomosis between the descending aorta and the posterior wall of the left common carotid, to oversew the patent ductus, and then to close the ventricular septal defect. I suggest that it is not always necessary to use interposed conduits. It may be very feasible to do a complete repair. Obviously, a long-term follow-up will provide further information. D R . F I S H M A N (Closing) I would like to thank the discussers for their very pertinent remarks. I will try to frame a satisfactory reply to their comments and also to answer their specific questions.

48

Fishman et al.

Total correction of an interrupted aortic arch and associated intracardiac anomalies in one stage is theoretically superior to the use of two stages to achieve the same result. As in all previous discussions concerning staging of other surgical procedures, the final appraisal of the relative safety and effectiveness of each approach to the correction of the interrupted aortic arch must await accumulation of a greater surgical experience than is now available for analysis. Incidentally, in none of our cases of Type B arch interruption was the descending aorta high enough in the thorax or of sufficient length to reach the ascending aorta at any point. If one is forced to use a vascular prosthesis or homograft in order to perform a single-stage total correction, the advantage of a single-stage total correction may be lost. The need for another operation when the patient has grown and the graft has become relatively stenotic must be anticipated. On the other hand, we have evidence in follow-up from 2 cases (one of which Dr. Nelson kindly described) that even a vessel of relatively small diameter may increase in size rather quickly when used as a shunt.

The Journal of Thoracic and Cardiovascular Surgery

Dr. Dobell's reminder that the vessel used as a shunt must be of adequate size merits further emphasis. More important than the long-term adequacy of the shunt is the need for adequate flow to the lower body and immediate relief of left ventricular strain if the infant is to survive the postoperative period. In our experience the vessel must be at least 3 mm. in diameter to achieve this purpose in the neonatal period. Dr. Dobell asked about the etiology of renal failure following repair of an aortic interruption in neonates. None of our patients with interrupted aortic arch had this complication. Acute renal failure may be caused by a prolonged period of aortic cross-clamping or by an inadequate lumen at the anastomosis or of the vessel used for the shunt. It may also reflect the nephrotoxic effects of radiocontrast material used in the preoperative cardiac catheterization, which is especially dangerous when used in large doses in the presence of decreased renal blood flow. During cardiac catheterization in neonates, the smallest possible dose of diluted contrast material should be used, just enough to analyze the anatomic details needed to plan the approach to the surgical repair.