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Coarctation in the first year of life
J
THoRAc CARDIOVASC SURG
86:9-17, 1983
Coarctation in the first year of life Patterns of postoperative effect From 1975 to 1982. 31 infants were operated upon in the first year of life for aortic coarctation and congestive heart failure. Operations performed were resection and end-to-end anastomosis (RETE) in 14. subclavianflap aortoplasty (SFA) in six. patch aortoplasty (PA) in five, and other procedures in six. Thirty of the thirty-one (97%) survived the operation. To assess the effect of operation, 26 infants were studied noninvasively with Doppler arm-to-leg pressure measurements at rest and with stress. Preoperatively, the median arm-to-leg gradient at rest was 77 mm Hg. Serial postoperative Doppler studies demonstrated progressive changes in arm-to-leg pressure gradients: 69% had residual arm-to-leg gradients that spontaneously resolved. 13% had residual gradients that persisted. 13% had progressive increase in gradient. and one child had neither early nor late gradient. Stress testing often unmasked gradients not present in the resting state. No differences were noted among the three surgical groups: RETE. SFA, and PA. From our experience, we have made four conclusions with regard to repair of coarctation of the aorta in infants. First. surgical survival is expected. Second. the effect of the operation is dynamic, with four patterns defined: (1) complete relief of coarctation, (2) transient residual coarctation, (3) persistent residual coarctation, and (4) recurrent coarctation. Third, optimal surgical therapy seems to be an eclectic approach. Fourth, physiological evaluation of coarctation in infants can be obtained by Doppler techniques in conjunction with stress testing.
1. Deane Waldman, M.D., John J. Lamberti, M.D., Allan H. Goodman, M.D., James W. Mathewson, M.D., Stanley E. Kirkpatrick, M.D., Lily George, M.D., Searle W. Turner, M.D., and Stanley J. Pappelbaum, M.D., San Diego. Calif.
Er infants with coarctation of the aorta, two issues of controversy persist: timing and type of operation. Some recommend delaying operation until the child is older and larger.' Proponents of early operation have strong and divergent preferences as to the best surgical technique." We considered a review of our patients instructive because our center has employed multiple surgical techniques and has conducted follow-up studies of the infants by simultaneous Doppler arm-leg pressures at rest and with stress. Patient population From January, 1975, through May, 1982,32 infants presented in congestive heart failure during the first year From the Pediatric Cardiology Medical Group and the Division of Cardiology, Children's Hospital of San Diego. the Earl Taylor Vascular Laboratory and the Cardiac Center, D. N. Sharp Hospital, San Diego, Calif. Received for publication Aug. II, 1982. Accepted for publication Oct. 7. 1982. Address for reprints: J. Deane Waldman, M.D., Division of Cardiology, Children's Hospital of San Diego, 8001 Frost St., San Diego, Calif. 92123.
of life at the Children's Hospital of San Diego with coarctation of the aorta or interrupted aortic arch. Urgent operation was performed in 31; operation was refused by the parents of one child with complex heart disease. In 13 of the 31 children, coarctation was an isolated defect; the other 18 children had multiple defects (Table I). Operations performed were resection and end-to-end anastomosis (RETE; 14), subclavian flap aortoplasty (SFA; six), patch aortoplasty (PA; five), combination of SFA and PA (one), combination of RETE and PA (one), ascending aortadescending aorta tube graft (two), and anastomosis of the left subclavian artery to the descending aorta (two). For analysis of surgical survival, the patient population includes all those operated upon in the first year of life (N = 31). The physiological effect of operation was evaluated by postoperative Doppler studies in 26 children. Eight normal neonates, chosen at random, were studied by the simultaneous Doppler technique to provide a control population. Mean age was 1.4 days and average weight was 4.0 kg. 9
The Journal of Thoracic and Cardiovascular Surgery
10 Waldman et al.
Table I. Infants operated upon at Children's Hospital of San Diego in the first year of life for coarctation of the aorta, 1975 through 1982 Case No. I 2 3
4 5 6
Diagnosis plus CoA MS, Sub-AS TGA, YSD, Sub-AS
Operation Age
2 wk 2 wk 1 mo
I
Doppler arm-to-leg gradient Procedure
RETE RETE RETE
AS, MS
1 mo
YSD
1 mo 2 mo
RETE RETE RETE
2 mo 3 mo
RETE RETE
7 8
9
3 mo
RETE
10
3 mo
RETE
II
AS
6 mo
RETE
12 13
TGA, YSD, Sub-AS
7 mo 8 mo
RETE RETE
14
YSD
9 mo
RETE
15
SY, SOCH, d-TGA
5 days
SFA+ PAB
16
20 days
SFA
17
1 mo
SFA
18
SY, d-TGA, SOCH
1 mo
SFA+ PAB
Time
I
Resting
I
Stress
Preop. 2 hr 8 days 9 mo 6 yr S days 2 yr 5 yr
77 16 3 -10 -8 -5 -13 -5
132
Preop.
118 -20 -19 -5 I 70 12 -10 -6 -10
X -7 -42 43 25 X X X -5 -10
62 50 -10 -4 -13 20 5 25 26 -2 -5 100 45 20 8 -5 118 40 6 0
115
2'/2 yr 5'/2 yr 3 yr 6 yr Preop. 3 hr 3 days 3 yr 5 yr Preop. 3 hr 10 mo Preop. 13 days 2 yr 3 yr 3 days 24 days 3'/2 mo 8 mo Preop. 6 days 4 mo 8 mo 15 mo Preop. 4 days 19 days 2 mo 15 mo Preop. 1 day 10 days 2 mo
0
80 52 25 5
12 -5 2 0 -7 3
-35 54 -6 48 25 55 47 -28 -11 X 50 30 X -13 92 18 7 -5 100 58 18 10
Legend: IAA, Interrupted aortic arch. VSD, Ventricular septal defect. Tube, Use of a prosthetic tube graft to bypass the coarctation. PAS, Pulmonary artery band. Times: Preop. indicates studies done within 48 hours before operation. All other times refer to the interval after operation. SFA. Subclavian nap aortoplasty. DOLV. Double-outlet left ventricle. PDA, Patent ductus arteriosus. PA, Prosthetic patch aortoplasty. RETE, Resection and end-to-end anastomosis. SV, Single ventricle.SOCH, Small outlet chamber. AS. Aortic stenosis. MS, Mitral stenosis. LCA-RV fistula, Left coronary artery to right ventricular fistula. S/IV, Superoinferior ventricles. LSA-DAo, End-ta-end anastomosis of the left subclavian artery to the descending aorta. I-MGA, Leva-malposition of the great arteries. Sub-AS. Subaortic stenosis. d-TGA, Dextra-transposition of the great arteries. 'This is the one child who died. Autopsy was not done.
Volume 86 Number 1 July, 1983
Coarctation operation in infants 1 1
Table I. Cont'd Case No.
Diagnosis plus CoA
Operation Age
I
Doppler arm-to-leg gradient Procedure
Time
I
Resting
I
Stress
The Journal of
12 Waldman et al.
Thoracic and Cardiovascular Surgery
+100 +80 Initial postoperative
+60
Arm-to-Leg Gradient
+40
at rest and
+20
with stress
0 -20
f'. · I ~V:-------#
--------------~----~----~---
:.---
R_S
R_S
R-S
R-S
SFA
PA
RETE
Other
Fig. 1. Arm-to-leg gradients early after coarctation repair, at rest (R) and with stress (S). Measurements were made prior to hospital discharge for three surgical procedures: subclavian flap aortoplasty (SFA), patch aortoplasty (PA), and resection with end-to-end anastomosis (RETE). Many infants have residual gradients which are exacerbated by stress.
electrocardiogram, mercury manometric calibration signal, and pulse appearance times of brachial and posterior tibial arteries during rapid bleed-off of occlusive pneumatic pressure to both respective limbs. Following several basal measurements "at rest," noxious stimuli were applied to increase the heart rate to at least 50% over the basal level. Resection with end-to-end anastomosis was performed in the standard fashion with a posterior running suture, anterior interrupted sutures, and oblique incisions made proximally and distally to splay open the site of anastomosis. Patch aortoplasty was performed as described by Vossschulte" with polytetrafluoroethylene* as the prosthetic material. Subclavian flap aortoplasty was performed in the fashion of Waldhausen and Nahrwold. Results Survival after coarctation operation. Of the 31 patients operated upon for coarctation in the first year of life, one died within 30 days of operation (No. 24, Table I). This infant with isolated coarctation presented at 3 months of age and had two preoperative cardiac arrests. Autopsy permission was not granted. Doppler findings. Normal neonates. At rest, mean systolic blood pressure in the right arm was 109 ± 19.6 mm Hg and simultaneous mean posterior tibial pressure was 111 ± 20.0 mm Hg. With crying, these pressures were 122 and *Manufactured by W. L. Gore & Associates, Inc., Elkton, Md., and Impra, Inc., Tempe, Ariz.
135 mm Hg, respectively. In seven of eight infants, the arm pressure at rest was lower than the leg pressure; in one child the blood pressure was 4 mm Hg higher in the right arm than in the leg. With crying, all infants had higher leg pressure than arm pressure. Coarctation children before operation. Before operation, 12 of 18 infants had large arm-to-leg gradients at rest (mean gradient 77 mm Hg); stress uniformly increased the arm-to-Ieg gradient (median gradient 92 mm Hg) in those tested. One child with a -4 mm Hg gradient at rest had a 54 mm Hg gradient with stress (No. 14, Table I). No correlation was found between the preoperative arm blood pressure and the arm-to-leg gradient. Coarctation children after operation. In the first 20 days after operation (Fig. 1), most infants had gradients over 10 mm Hg either at rest (11/20) or with stress (13/17). Stress testing uniformly increased the armto-leg gradient; in many cases, large gradients were found during stress testing of infants who had small or no gradient at rest. Early postoperative gradients were seen in all surgical groups: SFA, PA, RETE, and "other." Serial postoperative Doppler studies demonstrated gradual resolution of most gradients found early after operation (Fig. 2). The progressive decrease in gradient was sometimes evident in resting data, whereas in other cases the decrease in gradient was seen only in stress data (Table I). Spontaneous reduction in gradient was seen after RETE, SFA, and PA. Late follow-up Doppler data were available in 21 of 26 patients an average of 29 months after operation; in
Volume 86 Number 1
Coarctation operation in infants
July. 1983
AT REST
WITH STRESS
·100 f
-10
RETE
-.0
• '12.
Arm
• • • 10
rill
2
--
,
A
1
•
To
Preaaure
+10
B
• • 10 II ~
+100
+100
+10
RETE
'"0
-20
Syatolle
100
'"0
'"0
Leg
13
SFA
Gradient (mm Hg)
Ilau
• 1 a 10
D
c
2
+100
+100
PA
+10
+10
PA
+10
-20
•
'-'~ •• ' • 1 110.". • • ' ..... --......---.... DAYS' MO~THS YEARS
- ••
TIME AFTER SURGERY
F
E ....
YEARS
TIME AFTER SURGERY
Fig. 2. Serial arm-to-leg gradients at rest and with stress after coarctation operations in infants. RETE, Resection and end-to-end anastomosis. SFA, Subclavian flap aortoplasty. PA, Patch aortoplasty. Left-hand panels demonstrate data at rest after RETE (Panel A), SFA (Panel C}, and PA (Panel E). Right-hand panels demonstrate data with stress after RETE (Panel B), SFA (Panel D), and PA (Panel E).
five infants only perioperative studies were performed. An increase in the gradient over time was noted in two patients: Patient 14, who had an RETE, and Patient 30, who had a combination of SFA and PA. Late Doppler studies showed gradients of less than 10 mm Hg at rest in 19 of 21 children; resting gradients of 10 and 45 mm
Hg were found in two infants. Fifteen of 21 continued to have gradients less than Or equal to 10 mm Hg during stress, whereas five had stress gradients of 20 to 30 mm Hg; one child with a resting gradient of 45 mm Hg had a stress gradient of 90 mm Hg. Operations performed in the six children with late stress gradients were tube graft
14
The Journal of Thoracic and Cardiovascular Surgery
Waldman et af.
\>..
® 1\ "', I,
I,.,.
to Leg
<,
1\ \. © ....,..... ....-?,/
Gradient
(mm Hg)
A
1\\
Arm
o
\ ~-~-
../
. . .» :
.,.----
- . """"
... - - --+-- - - - . - - -_.!::':':'~
@
Fig. 3. Possible effects of coarctation operations performed in infancy. Pattern A, Persistent residual coarctation. Pattern B, Transient residual coarctation. Pattern C, Recurrent coarctation. Pattern D, "Cure" of coarctation (neither residual nor recurrent coarctation).
insertion (two), RETE (two), SFA plus PA (one), and PA (one). Discussion Optimal management for infants with coarctation and congestive heart failure continues to be controversial, the focuses being surgical survival and recoarctation. Surgical survival. Mortality considerations have played a major role in timing and choice of operation for infants with coarctation. Preoperative mortality rates for operations in the first year of life-l4% to 45% in the 1960s and early 1970s1O• 13-have decreased to 4% to 17% in more recent reports.v5,14 Since surgical mortality has been lower in older children," 7,13,15-17 some prefer to delay the operation. Bergdahl and associates,' reporting experience from the University of Alabama from 1967 to 1981, concluded that SFA resulted in a better operative survival rate than RETE. Our experience shows equally good survival rates with either procedure (15/15 with RETE and 8/8 with the SFA). We believe that the disparity in surgical survival noted by these authors may be related to the earlier time when RETE was used, when prostaglandin EI> rapid blood gas analysis, and other neonatal intensive care modalities were not available. Our one perioperative death occurred in a child who had had two cardiac arrests before the operation and died in low cardiac output. Fifty-eight percent (18/31) of our infants had major associated intracardiac defects; all were in congestive heart failure. Nonetheless, 30 of 31 (97%) infants survived, and we strongly believe that the child who died would have survived if he had reached medical attention before having had a cardiac
arrest. In short, we believe that surgical survival can be expected after coarctation repair at any age. Therefore, the operation need not be deferred in order to improve chances of survival. In a recent editorial, Waldhausen and co-workers" cited one sudden death and one acute collapse in two asymptomatic infants who had coarctation with congestive heart failure that had responded completely to medical therapy. These authors indicated that deferring the operation is not a risk-free option, and they recom-' mended prompt operation after the patient's condition is stabilized. We agree with Waldhausen's group that the operation should be performed promptly after work-up and institution of medical therapy. Recoarctation. The word "reeoarctation" can mean either coarctation once more (recurrent) or coarctation still (residual). Thus the presence of a gradient years after operation may indicate (1) initial relief of obstruction but no subsequent growth at the surgical site (recurrent coarctation, Fig. 3, pattern C), (2) inadequate relief of obstruction but relative subsequent growth (residual coarctation, Fig. 3, pattern A), or (3) a combination of residual and recurrent obstruction. In addition to ambiguity of meaning, recoarctation has been quantified in different ways, from "weak femoral pulses'? to a gradient at rest of over 35 mm Hg. 19 Thus both imprecise denotation as well as divergent quantitative definitions have led to reports of recoarctation ranging from 7% to 60% after repair of coarctation in infancy. 1.3, 5, 6,12,14,19·23 Data from our study indicate that the effect of coarctation procedures is a dynamic, ongoing phenomenon rather than a fixed, permanent status. Many infants have residual obstruction initially after operation, which may be due to hypoplasia of the transverse aortal, 24 (Fig. 4, A and B), edema from surgical manipulation, or disruption of elasticity and pulse wave propagation resulting from operation itself. However, over weeks or months, this obstruction may spontaneously resolve, so that at late postoperative follow-up (mean 29 months) most children (15/21) have gradients less than 10 mm Hg even with stress. This pattern of gradual spontaneous resolution of residual obstruction (Fig. 3, pattern B), not previously described, forces a reappraisal of the definition of surgical result. Some patients initially appear to have a poor surgical result (i.e., residual coarctation); on later evaluation, these same patients may have a good surgical result if obstruction is no longer present. Thus the word "recoarctation" appears to be excessively ambiguous; even the more precise terms of residual and recurrent coarctation must be considered points on a
Volume 86 Number 1 July. 1983
Coarctation operation in infants 1 5
RETE
PA
SFA
.
I'Ig. 4. Aortic images before (left) and after (right) various reparative procedures for coarctation of the aorta in infants. Panel A, Aortogram in 5-month-old child with discrete coarctation (white arrow). Panel B, Aortogram 6 years after resection and end-to-end anastomosis in patient seen in Panel A. Panel C, Right ventriculography in infant with dextro-transposition of the great arteries, ventricular septal defect, and coarctation. Panel D, Aortogram 7 months after patch aortoplasty, when stress gradient was 20 nun Hg. Panel E, Aortogram in Patient 25 (Table I) showing discrete coarctation and hypoplasia of the transverse aorta. Panel F, Six weeks after subclavian flap aortoplasty in Patient 25., there is no significant residual obstruction. Note absence of left subclavian artery compared to Panel E. AAo, AScending aorta. CoA, Coarctation. RETE, Resection and end-to-end anastomosis. MPA, Main pulmonary artery. RV, Right ventricle. LV, Left ventricle. PA, Patch aortoplasty. DAo, Descending aorta. SFA, Subclavian flap aortoplasty. LSA, Left subclavian artery .
dynamic continuum rather than permanent, immutable results. Treadmill or bicycle exercise stress testing after coarctation repair is increasingly?' 23, 25. 26 being utilized to evaluate aortic physiology with increased cardiac output. We have extended the use of stress testing to the infant and even the neonate. Absolute simultaneity of arm and leg pressure measurements is crucial because of
the extreme lability of blood pressure in very young children. Although the degree of stress was not exactly comparable between infants, the increase in cardiac output during stress often provided clinically useful information. For example, Patient 29 (Table I) had interrupted aortic arch, superoinferior ventricles, and multiple ventricular septal defects. After anastomosis of the left subclavian artery to the descending aorta and
The Journal of Thoracic and Cardiovascular Surgery
1 6 Waldman et al.
banding of the pulmonary artery in this infant, initial Doppler studies suggested excellent relief of obstruction, and clinically the child did well. However, the baby's condition began to deteriorate at 2 months of age, and even cardiac catheterization did not clearly indicate whether the coarctation repair should be revised or the pulmonary artery band should be tightened. Doppler studies suggested a mild degree of obstruction at rest but severe stenosis (105 mm Hg arm-to-leg gradient) with crying. The coarctation repair was revised and the child has subsequently done well, the "transient residual coarctation" having gradually resolved. Thus the lack of a large gradient at rest may falsely suggest the absence of obstruction, which can be unmasked by stress testing. Surgical techniques. Although it is more appealing to champion one operative approach over another, our Doppler data indicate that RETE, SFA, and PA can all yield good results when done during infancy. The choice of operation should be based on anatomy rather than personal preference. When there is a discrete area of narrowing (Fig. 4, A), RETE is still our operation of choice. There were no deaths, and late follow-up of these patients shows that none (0/9) has a significant gradient at rest. These findings are in contrast to reports of 16% to 50% recoarctation rates after RETE in infancy. 12,19,20 When stressed, seven of the nine continued to have no significant gradient. Two had gradients of 25 mm Hg with stress: In one, this was a residual gradient; in the other, the obstruction was recurrent. In patients with long-segment narrowing (Fig. 4, C), RETE may not be a suitable approach. Our results and those of others-v 5. 14, 25. 27 have shown that both SFA and PA can relieve obstruction and allow for growth. Both procedures have disadvantages: SFA causes permanent hypoperfusion of the left arm" and PA requires insertion of prosthetic material. In some cases, innovative approaches to relief of coarctation of the aorta have been useful. In two infants, the immediate effect of operation was considered inadequate in the surgical theater, and PA was added to the initial procedure. In two others, an end-to-side anastomosis between the subclavian artery and descending aorta for interrupted aortic arch was successful in restoring aortic continuity and allowing for growth. Tube graft insertion was efficacious in two infants with single ventricle, levo-malposition of the great arteries, and long-segment coarctation; the left-sided aorta allowed both graft insertion and banding of the pulmonary artery to be done concurrently. Of interest is the angiographically proven growth of the hypoplastic aorta
in a patient with an 8 mm conduit inserted between the ascending and descending aorta at 3 months of age.
2
3
4
5
6
7
8
9
10
II
12
13
14
REFERENCES Hartmann AF, Goldring D, Hernandez A, Behrer RM, Schad N, Ferguson T, Burford T, Crawford C: Recurrent coarctation of the aorta after successful repair in infancy. Am J Cardiol 25:405-410, 1970 Bergdahl LAL, Blackstone EH, Kirklin JW, Pacifico AD, Bargeron LM: Determinants of early success in repair of aortic coarctation in infants. J THORAC CARDIOVASC SURG' 83:736-742,1982 Hamilton DI, Di Eusanio G, Sandrasagra FA, Donnelly RJ: Early and late results of aortoplasty with a left subclavian flap for coarctation of the aorta in infancy. J THORAC CARDIOVASC SURG 75:699-704, 1978 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 Sade RB, Taylor AB, Chariker EP: Aortoplasty compared with resection for coarctation of the aorta in young children. Ann Thorac Surg 28:346-351, 1979 Hesslein PS, McNamara DG, Morriss MJH, Hallman GL, Cooley DA: Comparison of resection versus patch aortoplasty for repair of coarctation in infants and children. Circulation 64: 164-168, 1981 Waldman JD, Goodman AH, Tumeo AR, Lamberti JJ, Turner SW: Coarctation of the aorta. Noninvasive physiological assessment in infants and children before and after operation. J THORAC CARDIOVASC SURG 80:187-197, 1980. Vossschuite K: Surgical correction of coarctation of the aorta by an "isthmus-plastic" operation. Thorax 16:338345, 1961 Waldhausen JA, Nahrwold DL: Repair of coarctation of the aorta with a subclavian flap. J THORAC CARDIOVASC SURG 51:532-533, 1966 Fishman NH, Bronstein MH, Berman W, Roe BB, Edmunds LH, Robinson SJ, Rudolph AM: Surgical management of severe aortic coarctation and interrupted aortic arch in neonates. J THORAC CARDIOVASC SURG 71:35-47, 1976 Kilman JW, Williams TE, Breza TS, Craenen J, Hosier DM: Reversal of infant mortality by early surgical correction of coarctation of the aorta. Arch Surg 105:865-868, 1972 Connors JP, Hartmann AF, Weldon CS: Considerations in the surgical management of infantile coarctation of aorta. Am J Cardiol 36:489-492, 1975 Chiariello L, Agosti J, Subramanian S: Coarctation of the aorta in children and adolescents. Chest 70:621-626, 1976 Fleming WH, Sarafian LB, Clark EB, Dooley KJ, Hofschire PJ, Hopeman AR, Ruckman RN, Mooring PK: Critical aortic coarctation. Patch aortoplasty in infants less than age three months. Am J Cardiol 44:687-690, 1979
Volume 86 Number 1 July, 1983
15 Chen S, Fagan LF, Mudd GJF, Willman VL: Prognosis of infants with coarctation of the aorta. Am Heart J 94:557561, 1977 16 Liberthson RR, Pennington DG, Jacobs ML, Daggett WM: Coarctation of the aorta. Review of 234 patients and clarification of management problems. Am J Cardiol 43:835-840, 1979 17 Shinebourne EA, Tam ASY, Elseed AM, Paneth M, Lennox SC, Cleland WP, Lincoln C, Joseph MC, Anderson RH: Coarctation of the aorta in infancy and childhood. Br Heart J 38:375-380, 1976 18 Waldhausen JA, Whitman V, Werner JC, Pierce WS: Surgical intervention in infants with coarctation of the aorta. J THORAC CARDIOVASC SURG 81:323-325, 1981 19 Eshaghpour R, Olley PM: Recoaretation of the aorta following coarctectomy in the first year of life. J Pediatr 80:809-814, 1972 20 Pelletier C, Davingnon A, F-Ethier M, Stanley P: Coarctation ofthe aorta in infancy. J THORAC CARDIOVASC SURG 57: 171-179, 1969 21 Tawes RL, Aberdeen E, Waterston DJ, Bonham-Carter RE: Coarctation of the aorta in infants and children. Circulation 39:Suppl I: 173-184, 1969 22 Nanton MA, Olley PM: Residual hypertension after coarctectomy in children. Am J Cardiol 37:769-772, 1976
Coarctation operation in infants
17
23 Freed MD, Rocchini A, Rosenthal A, Nadas AS, Castaneda AR: Exercise-induced hypertension after surgical repair of coarctation of the aorta. Am J Cardiol 43:253258, 1979 24 Sinha SN, Kardatzke ML, Cole RB, Muster AJ, Wessel HU, Paul MH: Coarctation of the aorta. Circulation 40:385-398, 1969 25 Smith RT, Sade RM, Riopel DA, Taylor AB, Hohn AR, Crawford FA: Comparison of patch aortoplasty with resection for repair of coarctation in childhood by stress testing (abstr). Am J Cardiol 49:1048, 1982 26 Connor TM, Baker WP: A comparison of coarctation resection and patch angioplasty using post-exercise blood pressure measurements. Circulation 64:567-572, 1981 27 Reul GJ, Kabbani SS, Sandiford FM, Wukasch DC, Cooley DA: Repair of coarctation of the thoracic aorta by patch graft aortoplasty. J THORAC CARDIOVASC SURG 68:696-703, 1974 28 Lamberti JJ, Lodge FA, Waldman JD, Goodman AH: Vascular consequences of subclavian artery transection for Blalock-Taussig shunt (abstr). J Cardiovasc Surg 22:502, 1981 29 Shearer WT, Rutman JY, Weinberg WA, Godring D: Coarctation of the aorta and cerebrovascular accident. A proposal for early corrective surgery. J Pediatr 77:10041009, 1970
THoRAc CARDIOVASC SURG
86:9-17, 1983
Coarctation in the first year of life Patterns of postoperative effect From 1975 to 1982. 31 infants were operated upon in the first year of life for aortic coarctation and congestive heart failure. Operations performed were resection and end-to-end anastomosis (RETE) in 14. subclavianflap aortoplasty (SFA) in six. patch aortoplasty (PA) in five, and other procedures in six. Thirty of the thirty-one (97%) survived the operation. To assess the effect of operation, 26 infants were studied noninvasively with Doppler arm-to-leg pressure measurements at rest and with stress. Preoperatively, the median arm-to-leg gradient at rest was 77 mm Hg. Serial postoperative Doppler studies demonstrated progressive changes in arm-to-leg pressure gradients: 69% had residual arm-to-leg gradients that spontaneously resolved. 13% had residual gradients that persisted. 13% had progressive increase in gradient. and one child had neither early nor late gradient. Stress testing often unmasked gradients not present in the resting state. No differences were noted among the three surgical groups: RETE. SFA, and PA. From our experience, we have made four conclusions with regard to repair of coarctation of the aorta in infants. First. surgical survival is expected. Second. the effect of the operation is dynamic, with four patterns defined: (1) complete relief of coarctation, (2) transient residual coarctation, (3) persistent residual coarctation, and (4) recurrent coarctation. Third, optimal surgical therapy seems to be an eclectic approach. Fourth, physiological evaluation of coarctation in infants can be obtained by Doppler techniques in conjunction with stress testing.
1. Deane Waldman, M.D., John J. Lamberti, M.D., Allan H. Goodman, M.D., James W. Mathewson, M.D., Stanley E. Kirkpatrick, M.D., Lily George, M.D., Searle W. Turner, M.D., and Stanley J. Pappelbaum, M.D., San Diego. Calif.
Er infants with coarctation of the aorta, two issues of controversy persist: timing and type of operation. Some recommend delaying operation until the child is older and larger.' Proponents of early operation have strong and divergent preferences as to the best surgical technique." We considered a review of our patients instructive because our center has employed multiple surgical techniques and has conducted follow-up studies of the infants by simultaneous Doppler arm-leg pressures at rest and with stress. Patient population From January, 1975, through May, 1982,32 infants presented in congestive heart failure during the first year From the Pediatric Cardiology Medical Group and the Division of Cardiology, Children's Hospital of San Diego. the Earl Taylor Vascular Laboratory and the Cardiac Center, D. N. Sharp Hospital, San Diego, Calif. Received for publication Aug. II, 1982. Accepted for publication Oct. 7. 1982. Address for reprints: J. Deane Waldman, M.D., Division of Cardiology, Children's Hospital of San Diego, 8001 Frost St., San Diego, Calif. 92123.
of life at the Children's Hospital of San Diego with coarctation of the aorta or interrupted aortic arch. Urgent operation was performed in 31; operation was refused by the parents of one child with complex heart disease. In 13 of the 31 children, coarctation was an isolated defect; the other 18 children had multiple defects (Table I). Operations performed were resection and end-to-end anastomosis (RETE; 14), subclavian flap aortoplasty (SFA; six), patch aortoplasty (PA; five), combination of SFA and PA (one), combination of RETE and PA (one), ascending aortadescending aorta tube graft (two), and anastomosis of the left subclavian artery to the descending aorta (two). For analysis of surgical survival, the patient population includes all those operated upon in the first year of life (N = 31). The physiological effect of operation was evaluated by postoperative Doppler studies in 26 children. Eight normal neonates, chosen at random, were studied by the simultaneous Doppler technique to provide a control population. Mean age was 1.4 days and average weight was 4.0 kg. 9
The Journal of Thoracic and Cardiovascular Surgery
10 Waldman et al.
Table I. Infants operated upon at Children's Hospital of San Diego in the first year of life for coarctation of the aorta, 1975 through 1982 Case No. I 2 3
4 5 6
Diagnosis plus CoA MS, Sub-AS TGA, YSD, Sub-AS
Operation Age
2 wk 2 wk 1 mo
I
Doppler arm-to-leg gradient Procedure
RETE RETE RETE
AS, MS
1 mo
YSD
1 mo 2 mo
RETE RETE RETE
2 mo 3 mo
RETE RETE
7 8
9
3 mo
RETE
10
3 mo
RETE
II
AS
6 mo
RETE
12 13
TGA, YSD, Sub-AS
7 mo 8 mo
RETE RETE
14
YSD
9 mo
RETE
15
SY, SOCH, d-TGA
5 days
SFA+ PAB
16
20 days
SFA
17
1 mo
SFA
18
SY, d-TGA, SOCH
1 mo
SFA+ PAB
Time
I
Resting
I
Stress
Preop. 2 hr 8 days 9 mo 6 yr S days 2 yr 5 yr
77 16 3 -10 -8 -5 -13 -5
132
Preop.
118 -20 -19 -5 I 70 12 -10 -6 -10
X -7 -42 43 25 X X X -5 -10
62 50 -10 -4 -13 20 5 25 26 -2 -5 100 45 20 8 -5 118 40 6 0
115
2'/2 yr 5'/2 yr 3 yr 6 yr Preop. 3 hr 3 days 3 yr 5 yr Preop. 3 hr 10 mo Preop. 13 days 2 yr 3 yr 3 days 24 days 3'/2 mo 8 mo Preop. 6 days 4 mo 8 mo 15 mo Preop. 4 days 19 days 2 mo 15 mo Preop. 1 day 10 days 2 mo
0
80 52 25 5
12 -5 2 0 -7 3
-35 54 -6 48 25 55 47 -28 -11 X 50 30 X -13 92 18 7 -5 100 58 18 10
Legend: IAA, Interrupted aortic arch. VSD, Ventricular septal defect. Tube, Use of a prosthetic tube graft to bypass the coarctation. PAS, Pulmonary artery band. Times: Preop. indicates studies done within 48 hours before operation. All other times refer to the interval after operation. SFA. Subclavian nap aortoplasty. DOLV. Double-outlet left ventricle. PDA, Patent ductus arteriosus. PA, Prosthetic patch aortoplasty. RETE, Resection and end-to-end anastomosis. SV, Single ventricle.SOCH, Small outlet chamber. AS. Aortic stenosis. MS, Mitral stenosis. LCA-RV fistula, Left coronary artery to right ventricular fistula. S/IV, Superoinferior ventricles. LSA-DAo, End-ta-end anastomosis of the left subclavian artery to the descending aorta. I-MGA, Leva-malposition of the great arteries. Sub-AS. Subaortic stenosis. d-TGA, Dextra-transposition of the great arteries. 'This is the one child who died. Autopsy was not done.
Volume 86 Number 1 July, 1983
Coarctation operation in infants 1 1
Table I. Cont'd Case No.
Diagnosis plus CoA
Operation Age
I
Doppler arm-to-leg gradient Procedure
Time
I
Resting
I
Stress
The Journal of
12 Waldman et al.
Thoracic and Cardiovascular Surgery
+100 +80 Initial postoperative
+60
Arm-to-Leg Gradient
+40
at rest and
+20
with stress
0 -20
f'. · I ~V:-------#
--------------~----~----~---
:.---
R_S
R_S
R-S
R-S
SFA
PA
RETE
Other
Fig. 1. Arm-to-leg gradients early after coarctation repair, at rest (R) and with stress (S). Measurements were made prior to hospital discharge for three surgical procedures: subclavian flap aortoplasty (SFA), patch aortoplasty (PA), and resection with end-to-end anastomosis (RETE). Many infants have residual gradients which are exacerbated by stress.
electrocardiogram, mercury manometric calibration signal, and pulse appearance times of brachial and posterior tibial arteries during rapid bleed-off of occlusive pneumatic pressure to both respective limbs. Following several basal measurements "at rest," noxious stimuli were applied to increase the heart rate to at least 50% over the basal level. Resection with end-to-end anastomosis was performed in the standard fashion with a posterior running suture, anterior interrupted sutures, and oblique incisions made proximally and distally to splay open the site of anastomosis. Patch aortoplasty was performed as described by Vossschulte" with polytetrafluoroethylene* as the prosthetic material. Subclavian flap aortoplasty was performed in the fashion of Waldhausen and Nahrwold. Results Survival after coarctation operation. Of the 31 patients operated upon for coarctation in the first year of life, one died within 30 days of operation (No. 24, Table I). This infant with isolated coarctation presented at 3 months of age and had two preoperative cardiac arrests. Autopsy permission was not granted. Doppler findings. Normal neonates. At rest, mean systolic blood pressure in the right arm was 109 ± 19.6 mm Hg and simultaneous mean posterior tibial pressure was 111 ± 20.0 mm Hg. With crying, these pressures were 122 and *Manufactured by W. L. Gore & Associates, Inc., Elkton, Md., and Impra, Inc., Tempe, Ariz.
135 mm Hg, respectively. In seven of eight infants, the arm pressure at rest was lower than the leg pressure; in one child the blood pressure was 4 mm Hg higher in the right arm than in the leg. With crying, all infants had higher leg pressure than arm pressure. Coarctation children before operation. Before operation, 12 of 18 infants had large arm-to-leg gradients at rest (mean gradient 77 mm Hg); stress uniformly increased the arm-to-Ieg gradient (median gradient 92 mm Hg) in those tested. One child with a -4 mm Hg gradient at rest had a 54 mm Hg gradient with stress (No. 14, Table I). No correlation was found between the preoperative arm blood pressure and the arm-to-leg gradient. Coarctation children after operation. In the first 20 days after operation (Fig. 1), most infants had gradients over 10 mm Hg either at rest (11/20) or with stress (13/17). Stress testing uniformly increased the armto-leg gradient; in many cases, large gradients were found during stress testing of infants who had small or no gradient at rest. Early postoperative gradients were seen in all surgical groups: SFA, PA, RETE, and "other." Serial postoperative Doppler studies demonstrated gradual resolution of most gradients found early after operation (Fig. 2). The progressive decrease in gradient was sometimes evident in resting data, whereas in other cases the decrease in gradient was seen only in stress data (Table I). Spontaneous reduction in gradient was seen after RETE, SFA, and PA. Late follow-up Doppler data were available in 21 of 26 patients an average of 29 months after operation; in
Volume 86 Number 1
Coarctation operation in infants
July. 1983
AT REST
WITH STRESS
·100 f
-10
RETE
-.0
• '12.
Arm
• • • 10
rill
2
--
,
A
1
•
To
Preaaure
+10
B
• • 10 II ~
+100
+100
+10
RETE
'"0
-20
Syatolle
100
'"0
'"0
Leg
13
SFA
Gradient (mm Hg)
Ilau
• 1 a 10
D
c
2
+100
+100
PA
+10
+10
PA
+10
-20
•
'-'~ •• ' • 1 110.". • • ' ..... --......---.... DAYS' MO~THS YEARS
- ••
TIME AFTER SURGERY
F
E ....
YEARS
TIME AFTER SURGERY
Fig. 2. Serial arm-to-leg gradients at rest and with stress after coarctation operations in infants. RETE, Resection and end-to-end anastomosis. SFA, Subclavian flap aortoplasty. PA, Patch aortoplasty. Left-hand panels demonstrate data at rest after RETE (Panel A), SFA (Panel C}, and PA (Panel E). Right-hand panels demonstrate data with stress after RETE (Panel B), SFA (Panel D), and PA (Panel E).
five infants only perioperative studies were performed. An increase in the gradient over time was noted in two patients: Patient 14, who had an RETE, and Patient 30, who had a combination of SFA and PA. Late Doppler studies showed gradients of less than 10 mm Hg at rest in 19 of 21 children; resting gradients of 10 and 45 mm
Hg were found in two infants. Fifteen of 21 continued to have gradients less than Or equal to 10 mm Hg during stress, whereas five had stress gradients of 20 to 30 mm Hg; one child with a resting gradient of 45 mm Hg had a stress gradient of 90 mm Hg. Operations performed in the six children with late stress gradients were tube graft
14
The Journal of Thoracic and Cardiovascular Surgery
Waldman et af.
\>..
® 1\ "', I,
I,.,.
to Leg
<,
1\ \. © ....,..... ....-?,/
Gradient
(mm Hg)
A
1\\
Arm
o
\ ~-~-
../
. . .» :
.,.----
- . """"
... - - --+-- - - - . - - -_.!::':':'~
@
Fig. 3. Possible effects of coarctation operations performed in infancy. Pattern A, Persistent residual coarctation. Pattern B, Transient residual coarctation. Pattern C, Recurrent coarctation. Pattern D, "Cure" of coarctation (neither residual nor recurrent coarctation).
insertion (two), RETE (two), SFA plus PA (one), and PA (one). Discussion Optimal management for infants with coarctation and congestive heart failure continues to be controversial, the focuses being surgical survival and recoarctation. Surgical survival. Mortality considerations have played a major role in timing and choice of operation for infants with coarctation. Preoperative mortality rates for operations in the first year of life-l4% to 45% in the 1960s and early 1970s1O• 13-have decreased to 4% to 17% in more recent reports.v5,14 Since surgical mortality has been lower in older children," 7,13,15-17 some prefer to delay the operation. Bergdahl and associates,' reporting experience from the University of Alabama from 1967 to 1981, concluded that SFA resulted in a better operative survival rate than RETE. Our experience shows equally good survival rates with either procedure (15/15 with RETE and 8/8 with the SFA). We believe that the disparity in surgical survival noted by these authors may be related to the earlier time when RETE was used, when prostaglandin EI> rapid blood gas analysis, and other neonatal intensive care modalities were not available. Our one perioperative death occurred in a child who had had two cardiac arrests before the operation and died in low cardiac output. Fifty-eight percent (18/31) of our infants had major associated intracardiac defects; all were in congestive heart failure. Nonetheless, 30 of 31 (97%) infants survived, and we strongly believe that the child who died would have survived if he had reached medical attention before having had a cardiac
arrest. In short, we believe that surgical survival can be expected after coarctation repair at any age. Therefore, the operation need not be deferred in order to improve chances of survival. In a recent editorial, Waldhausen and co-workers" cited one sudden death and one acute collapse in two asymptomatic infants who had coarctation with congestive heart failure that had responded completely to medical therapy. These authors indicated that deferring the operation is not a risk-free option, and they recom-' mended prompt operation after the patient's condition is stabilized. We agree with Waldhausen's group that the operation should be performed promptly after work-up and institution of medical therapy. Recoarctation. The word "reeoarctation" can mean either coarctation once more (recurrent) or coarctation still (residual). Thus the presence of a gradient years after operation may indicate (1) initial relief of obstruction but no subsequent growth at the surgical site (recurrent coarctation, Fig. 3, pattern C), (2) inadequate relief of obstruction but relative subsequent growth (residual coarctation, Fig. 3, pattern A), or (3) a combination of residual and recurrent obstruction. In addition to ambiguity of meaning, recoarctation has been quantified in different ways, from "weak femoral pulses'? to a gradient at rest of over 35 mm Hg. 19 Thus both imprecise denotation as well as divergent quantitative definitions have led to reports of recoarctation ranging from 7% to 60% after repair of coarctation in infancy. 1.3, 5, 6,12,14,19·23 Data from our study indicate that the effect of coarctation procedures is a dynamic, ongoing phenomenon rather than a fixed, permanent status. Many infants have residual obstruction initially after operation, which may be due to hypoplasia of the transverse aortal, 24 (Fig. 4, A and B), edema from surgical manipulation, or disruption of elasticity and pulse wave propagation resulting from operation itself. However, over weeks or months, this obstruction may spontaneously resolve, so that at late postoperative follow-up (mean 29 months) most children (15/21) have gradients less than 10 mm Hg even with stress. This pattern of gradual spontaneous resolution of residual obstruction (Fig. 3, pattern B), not previously described, forces a reappraisal of the definition of surgical result. Some patients initially appear to have a poor surgical result (i.e., residual coarctation); on later evaluation, these same patients may have a good surgical result if obstruction is no longer present. Thus the word "recoarctation" appears to be excessively ambiguous; even the more precise terms of residual and recurrent coarctation must be considered points on a
Volume 86 Number 1 July. 1983
Coarctation operation in infants 1 5
RETE
PA
SFA
.
I'Ig. 4. Aortic images before (left) and after (right) various reparative procedures for coarctation of the aorta in infants. Panel A, Aortogram in 5-month-old child with discrete coarctation (white arrow). Panel B, Aortogram 6 years after resection and end-to-end anastomosis in patient seen in Panel A. Panel C, Right ventriculography in infant with dextro-transposition of the great arteries, ventricular septal defect, and coarctation. Panel D, Aortogram 7 months after patch aortoplasty, when stress gradient was 20 nun Hg. Panel E, Aortogram in Patient 25 (Table I) showing discrete coarctation and hypoplasia of the transverse aorta. Panel F, Six weeks after subclavian flap aortoplasty in Patient 25., there is no significant residual obstruction. Note absence of left subclavian artery compared to Panel E. AAo, AScending aorta. CoA, Coarctation. RETE, Resection and end-to-end anastomosis. MPA, Main pulmonary artery. RV, Right ventricle. LV, Left ventricle. PA, Patch aortoplasty. DAo, Descending aorta. SFA, Subclavian flap aortoplasty. LSA, Left subclavian artery .
dynamic continuum rather than permanent, immutable results. Treadmill or bicycle exercise stress testing after coarctation repair is increasingly?' 23, 25. 26 being utilized to evaluate aortic physiology with increased cardiac output. We have extended the use of stress testing to the infant and even the neonate. Absolute simultaneity of arm and leg pressure measurements is crucial because of
the extreme lability of blood pressure in very young children. Although the degree of stress was not exactly comparable between infants, the increase in cardiac output during stress often provided clinically useful information. For example, Patient 29 (Table I) had interrupted aortic arch, superoinferior ventricles, and multiple ventricular septal defects. After anastomosis of the left subclavian artery to the descending aorta and
The Journal of Thoracic and Cardiovascular Surgery
1 6 Waldman et al.
banding of the pulmonary artery in this infant, initial Doppler studies suggested excellent relief of obstruction, and clinically the child did well. However, the baby's condition began to deteriorate at 2 months of age, and even cardiac catheterization did not clearly indicate whether the coarctation repair should be revised or the pulmonary artery band should be tightened. Doppler studies suggested a mild degree of obstruction at rest but severe stenosis (105 mm Hg arm-to-leg gradient) with crying. The coarctation repair was revised and the child has subsequently done well, the "transient residual coarctation" having gradually resolved. Thus the lack of a large gradient at rest may falsely suggest the absence of obstruction, which can be unmasked by stress testing. Surgical techniques. Although it is more appealing to champion one operative approach over another, our Doppler data indicate that RETE, SFA, and PA can all yield good results when done during infancy. The choice of operation should be based on anatomy rather than personal preference. When there is a discrete area of narrowing (Fig. 4, A), RETE is still our operation of choice. There were no deaths, and late follow-up of these patients shows that none (0/9) has a significant gradient at rest. These findings are in contrast to reports of 16% to 50% recoarctation rates after RETE in infancy. 12,19,20 When stressed, seven of the nine continued to have no significant gradient. Two had gradients of 25 mm Hg with stress: In one, this was a residual gradient; in the other, the obstruction was recurrent. In patients with long-segment narrowing (Fig. 4, C), RETE may not be a suitable approach. Our results and those of others-v 5. 14, 25. 27 have shown that both SFA and PA can relieve obstruction and allow for growth. Both procedures have disadvantages: SFA causes permanent hypoperfusion of the left arm" and PA requires insertion of prosthetic material. In some cases, innovative approaches to relief of coarctation of the aorta have been useful. In two infants, the immediate effect of operation was considered inadequate in the surgical theater, and PA was added to the initial procedure. In two others, an end-to-side anastomosis between the subclavian artery and descending aorta for interrupted aortic arch was successful in restoring aortic continuity and allowing for growth. Tube graft insertion was efficacious in two infants with single ventricle, levo-malposition of the great arteries, and long-segment coarctation; the left-sided aorta allowed both graft insertion and banding of the pulmonary artery to be done concurrently. Of interest is the angiographically proven growth of the hypoplastic aorta
in a patient with an 8 mm conduit inserted between the ascending and descending aorta at 3 months of age.
2
3
4
5
6
7
8
9
10
II
12
13
14
REFERENCES Hartmann AF, Goldring D, Hernandez A, Behrer RM, Schad N, Ferguson T, Burford T, Crawford C: Recurrent coarctation of the aorta after successful repair in infancy. Am J Cardiol 25:405-410, 1970 Bergdahl LAL, Blackstone EH, Kirklin JW, Pacifico AD, Bargeron LM: Determinants of early success in repair of aortic coarctation in infants. J THORAC CARDIOVASC SURG' 83:736-742,1982 Hamilton DI, Di Eusanio G, Sandrasagra FA, Donnelly RJ: Early and late results of aortoplasty with a left subclavian flap for coarctation of the aorta in infancy. J THORAC CARDIOVASC SURG 75:699-704, 1978 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 Sade RB, Taylor AB, Chariker EP: Aortoplasty compared with resection for coarctation of the aorta in young children. Ann Thorac Surg 28:346-351, 1979 Hesslein PS, McNamara DG, Morriss MJH, Hallman GL, Cooley DA: Comparison of resection versus patch aortoplasty for repair of coarctation in infants and children. Circulation 64: 164-168, 1981 Waldman JD, Goodman AH, Tumeo AR, Lamberti JJ, Turner SW: Coarctation of the aorta. Noninvasive physiological assessment in infants and children before and after operation. J THORAC CARDIOVASC SURG 80:187-197, 1980. Vossschuite K: Surgical correction of coarctation of the aorta by an "isthmus-plastic" operation. Thorax 16:338345, 1961 Waldhausen JA, Nahrwold DL: Repair of coarctation of the aorta with a subclavian flap. J THORAC CARDIOVASC SURG 51:532-533, 1966 Fishman NH, Bronstein MH, Berman W, Roe BB, Edmunds LH, Robinson SJ, Rudolph AM: Surgical management of severe aortic coarctation and interrupted aortic arch in neonates. J THORAC CARDIOVASC SURG 71:35-47, 1976 Kilman JW, Williams TE, Breza TS, Craenen J, Hosier DM: Reversal of infant mortality by early surgical correction of coarctation of the aorta. Arch Surg 105:865-868, 1972 Connors JP, Hartmann AF, Weldon CS: Considerations in the surgical management of infantile coarctation of aorta. Am J Cardiol 36:489-492, 1975 Chiariello L, Agosti J, Subramanian S: Coarctation of the aorta in children and adolescents. Chest 70:621-626, 1976 Fleming WH, Sarafian LB, Clark EB, Dooley KJ, Hofschire PJ, Hopeman AR, Ruckman RN, Mooring PK: Critical aortic coarctation. Patch aortoplasty in infants less than age three months. Am J Cardiol 44:687-690, 1979
Volume 86 Number 1 July, 1983
15 Chen S, Fagan LF, Mudd GJF, Willman VL: Prognosis of infants with coarctation of the aorta. Am Heart J 94:557561, 1977 16 Liberthson RR, Pennington DG, Jacobs ML, Daggett WM: Coarctation of the aorta. Review of 234 patients and clarification of management problems. Am J Cardiol 43:835-840, 1979 17 Shinebourne EA, Tam ASY, Elseed AM, Paneth M, Lennox SC, Cleland WP, Lincoln C, Joseph MC, Anderson RH: Coarctation of the aorta in infancy and childhood. Br Heart J 38:375-380, 1976 18 Waldhausen JA, Whitman V, Werner JC, Pierce WS: Surgical intervention in infants with coarctation of the aorta. J THORAC CARDIOVASC SURG 81:323-325, 1981 19 Eshaghpour R, Olley PM: Recoaretation of the aorta following coarctectomy in the first year of life. J Pediatr 80:809-814, 1972 20 Pelletier C, Davingnon A, F-Ethier M, Stanley P: Coarctation ofthe aorta in infancy. J THORAC CARDIOVASC SURG 57: 171-179, 1969 21 Tawes RL, Aberdeen E, Waterston DJ, Bonham-Carter RE: Coarctation of the aorta in infants and children. Circulation 39:Suppl I: 173-184, 1969 22 Nanton MA, Olley PM: Residual hypertension after coarctectomy in children. Am J Cardiol 37:769-772, 1976
Coarctation operation in infants
17
23 Freed MD, Rocchini A, Rosenthal A, Nadas AS, Castaneda AR: Exercise-induced hypertension after surgical repair of coarctation of the aorta. Am J Cardiol 43:253258, 1979 24 Sinha SN, Kardatzke ML, Cole RB, Muster AJ, Wessel HU, Paul MH: Coarctation of the aorta. Circulation 40:385-398, 1969 25 Smith RT, Sade RM, Riopel DA, Taylor AB, Hohn AR, Crawford FA: Comparison of patch aortoplasty with resection for repair of coarctation in childhood by stress testing (abstr). Am J Cardiol 49:1048, 1982 26 Connor TM, Baker WP: A comparison of coarctation resection and patch angioplasty using post-exercise blood pressure measurements. Circulation 64:567-572, 1981 27 Reul GJ, Kabbani SS, Sandiford FM, Wukasch DC, Cooley DA: Repair of coarctation of the thoracic aorta by patch graft aortoplasty. J THORAC CARDIOVASC SURG 68:696-703, 1974 28 Lamberti JJ, Lodge FA, Waldman JD, Goodman AH: Vascular consequences of subclavian artery transection for Blalock-Taussig shunt (abstr). J Cardiovasc Surg 22:502, 1981 29 Shearer WT, Rutman JY, Weinberg WA, Godring D: Coarctation of the aorta and cerebrovascular accident. A proposal for early corrective surgery. J Pediatr 77:10041009, 1970