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Coarctation of the aorta in infants
J
THoRAc CARDIOVASC SURG
88:1012-1019, 1984
Coarctation of the aorta in infants Repair of coarctation of the aorta in the first year of life by resection and end-to-end anastomosis has been reported to have a high rate of recurrence, and recent studies favor angioplasty techniques. Forty-sevenconsecutive infants less than 1 year of age whowereoperated upon overa 20 year periodwere analyzed. The hospital mortality was analyzed in three groups: Group I-two of 11 patients (18%) with coarctation; Group II-one of nine patients (11 %) with coarctation and ventricularseptal defect; Group m-12 of 27 patients (44%) with coarctation and major intracardiac anomalies.There was no difference in age or body surface area betweensurvivors and nonsurvivors. Repair was pedormed by a resection and end-to-end anastomosis to the distal aortic arch in 43 and by patch angioplastyin four. Anastomosiswas pedormed with >0 silk suture prior to 1972. Since then, 7-0 polypropylene suture has generally been used. Arm/leg pressure gradient was assessed at rest by the Doppler technique in 31 long-term survivors of the end-to-end anastomosis technique; 24 of them had polypropylene suture used and seven bad silk suture. Recurrence of coarctation was defmed as arm/leg gradient >- 20 mm Hg. Actuarial freedomfrom recurrence at 5 and 10 years was 91 % in the polypropylene group versus57% and 44% in the silk group. Good long-term results with low incidence of recurrent coarctation achieved by end-to-end anastomosis with fine polypropylene suture justify continued use of this technique in preference to angioplasty techniques, whichsacrifice the left subclavian artery or introduce prosthetic materials. Techniqueschosen for coarctation repair should be compared with current operative techniques and not older studies. John L. Harlan, M.D., Donald B. Doty, M.D., * Berkeley Brandt III, M.D., and Johann L. Ehrenhaft, M.D., Iowa City, Iowa
Coarctation of the aorta has been a correctable surgical lesion for nearly 40 years. Since the pioneering operation of Crafoord and Nylin,' resection of coarctation of the aorta and end-to-end anastomosis has been the most widely practiced surgical method. Recurrence of the coarctation, defined as a resting gradient of 20 mm Hg or greater in blood pressure measured in the arm and leg, seems to be an important problem with this surgical technique, especially when the repair is done in the first year of life. Williams and associates' found the actuarial incidence of recurrence of coarctation to be 42% at 5 years in a group of infants having repair of coarctation of the aorta at less than 1 year of age. Tawes From the Division of Thoracic and Cardiovascular Surgery, Department of Surgery, University of Iowa Hospitals and Clinics, Iowa City, Iowa. Received for publication Aug. 31, 1983. Accepted for publication Jan. 26, 1984. Address for reprints: Division of Thoracic and Cardiovascular Surgery, University of Iowa Hospitals and Clinics, Iowa City, Iowa 52242. *Current address: Donald B. Doty, M.D., 324 Tenth Ave., Salt Lake City, Utah 84103.
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and associates' reported an alarming 14 of 20 patients with recurrent coarctation when the repair was performed in the first 3 months of life. The cause of recurrent coarctation is obscure. The various theories postulated have included inadequate growth of the anastomosis and actual residual coarctation at the time of repair.t' In order to alleviate the former problem, the anterior row of sutures has traditionally been interrupted to permit growth of the aorta at the anastomosis.The latter problem, which represents inadequate repair, has been addressed by techniques that assure the widest possible initial anastomosis. The subclavian flap technique as proposed by Waldhausen and Nahrwold," in which the left subclavian artery is turned down as a flap patch to widen the unresected coarcted segment of aorta, has recently become popular. This has been advocated by some authors as the method of choice in repair of coarctation of the aorta in
infants." 7,8
This study reviews a 20 year experiencewith repair of coarctation of the aorta, which has been accomplished in most cases by resection and creation of the largest possible end-to-end anastomosis, in a group of infants less than 1 year of age.
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Coarctation of aorta
December, 1984
Table I. Anatomic distribution in infants less
Table II. Infants less than 1 year of age with
than 1 year of age undergoing coarctation repair
coarctation and major cardiac anomalies
Hospital deaths* Group Group I: Coarctation Group II: Coarctation with isolated VSD Group III: Coarctation with major cardiac anomalies
No. II
No.
I% I
70% CL
9
2 I
18 II
5%-32% 1%-23%
27
12
44
34%-55%
47
15
32
250/0-39%
Legend: CL, Confidencelimits.
• Hospital death includes operative mortality and mortality associated with second procedureduring same hospitalization.
Patients and methods The hospital records of all patients less than 1 year of age undergoing repair of coarctation of the aorta at The University of Iowa Hospitals for the 20 year period from June, 1962, to June, 1982, were reviewed. Forty-seven patients were identified for analysis. Sixteen of these had mild transverse arch hypoplasia on cineangiogram. Eight other patients with marked hypoplasia of the transverse arch and coarctation or aortic atresia and coarctation were not included. The patients were divided into three categories (Table I): Group I-patients with isolated coarctation of the aorta and without major intracardiac anomalies; Group II-patients with coarctation and ventricular septal defect; and Group 111patients with coarctation and associated major intracardiac anomalies (Table 11). Patent ductus arteriosus was commonly associated with coarctation of the aorta in all three groups. Seven patients in Group I, seven patients in Group II, and 20 patients in Group III had closure of the ductus arteriosus, when present, at the time of repair of the coarctation. All patients had congestive heart failure prior to operation. Two patients had central nervous system irritability manifest by seizures preoperatively, and one patient had severe myocardial failure with hypotension (cardiogenic shock) and respiratory failure necessitating endotracheal intubation prior to emergency operation. Forty-one patients had cardiomegaly on chest roentgenogram prior to operation, and 31 had increased pulmonary vascular markings. Electrocardiogram revealed cardiac hypertrophy in nearly all patients, with combined ventricular hypertrophy in 21, left ventricular hypertrophy in eight, and right ventricular hypertrophy in 13. One infant had dextrocardia, making interpretation of hypertrophy criteria obscure, and one had left axis deviation. Only two patients had normal electrocardiograms.
Congenital aortic stenosis Subvalvular Valvular Congenital aortic stenosis and infundibular pulmonic stenosis Congenital mitral incompetence With VSD VSD and ASD MUltiple VSDs Single ventricle with transposition Transposition With VSD and ASD With hypoplastic right heart With hypoplastic left heart With dextrocardia, VSD, and ASD Double-outlet right ventricle Totals
EJ 6
10 1 3
Hospital deaths 3
I 5
3 4 4 2
I 3
6
3
3 I I I
I 27
I 12 (44%) (70% CL 340/0-55%)
Legend: VSD, Ventricular septal defect. ASD, Atrial septal defect.
Cardiac catheterization. Three of the 47 patients were operated upon prior to the use of cardiac catheterization. Routinely, catheterization included' oximetry, pressure determinations, ventriculography, and aortography. In 20 patients the pressure gradient across the coarctation was measured. In the remaining 24 patients the diagnosis was confirmed by cineangiogram, as the coarctation did not allow retrograde passage of the catheter from the descending aorta. Operative technique. The operation was performed in all patients through a posterolateral thoracotomy on the left side. The chest was entered through the intercostal space or bed of the unresected fourth rib. The aorta was completely mobilized, including the distal arch, the left subclavian artery, and the upper half of the descending thoracic aorta. Intercostal arteries were sacrificed only as required for adequate mobilization and control of the anastomotic site. The ductus arteriosus was mobilized and ligated when present. Vascular occlusiveclamps were placed across the distal portion of the arch near or across the origin of the left common carotid artery (occasionally proximal to it) and the upper descending thoracic aorta distal to the coarctation (Fig. 1, A). The stenotic segment was excised in a fashion to achieve maximal aortic diameter. The proximal incision was made across the aorta just distal to the left subclavian artery and extended into the lateral wall of the left subclavian artery or more proximally into the inferior aspect of the distal aortic arch. The distal
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The Journal of Thoracic and Cardiovascular Surgery
Harlan et al.
Table IV. Management of infants less than 1 year of age with coarctation and major cardiac anomalies (Group III) Hospital deaths
Coarctation repair only Coarctation repair and PA banding Coarctation repair and one-stage primary repair Coarctation repair and two-stage repair during same hospitalization Totals
Fig. 1. Technique of operative repair. Proximal incision extends from undersurface of the transverse arch of the aorta to the lateral wall of the left subclavian artery. (See text for details.)
Table m. Management of infants less than 1 year of age with coarctation and isolated VSD (Group II) Hospital deaths
Coarctation Coarctation Coarctation one-stage Totals
o
repair only repair and PA banding repair and primary VSD repair
1
o 9
1 (11%) (70% CL 1%-23%)
Legend: VSD, Ventricular septal defect. PA, Pulmonary artery.
incision was made into the wide portion of the upper thoracic aorta at an appropriate 30 to 40 degree angle to match the orientation of the proximal incision and assure the widest possible aortic diameter for anastomosis (Fig. 1, B). The anastomosis was performed with a fme running suture on the posterior aspect, and the anterior row of sutures was interrupted to allow for growth of the aorta (Fig. 1, C). Prior to 1972, 5-0 silk suture was used, and subsequently anastomoses were performed with 7-0 or 6-0 polypropylene suture. In four patients the coarctation was repaired by patch grafting with the excised subclavian artery, which was split longitudinally for an aortoplasty that extended from the left common carotid artery through the coarctation to the upper descending thoracic aorta. This method is no longer used. Pulmonary artery banding was performed simultaneously with repair of the coarctation in only one of the
4
27
4
12 (44%) (70% CL 340/0-55%)
nine patients who had coarctation associated with isolated ventricular septal defect. Four of these nine patients had primary one-stage repair of both defects. Coarctation resection and anastomosis was followed by repositioning for a median sternotomy for closure of the ventricular septal defect at the same operation (Table III). In seven of the patients with coarctation associated with other complex lesions, pulmonary artery banding was performed in addition to the coarctation repair. Only three of the 27 patients in this group, however, had a primary one-stage repair (Table IV). Four patients subsequently required staged repair of associated intracardiac anomalies during the same hospitalization for intractable congestive heart failure from 3 to 8 weeks after coarctation repair, and all four subsequently died during hospitalization. Statistical methods. The data were arranged in contingency tables. Analysis was performed with a two-sample t test or chi square test where applicable. The data for survival and recurrence were analyzed by the actuarial method of Kaplan and Meier." Mean values are expressed with standard error of mean and proportions are shown with their 70% confidence limits (CL). Results There was no statistical difference in hospital mortality between Group I (18%) and Group II (11%). The combined mortality for these two groups (15%, 3/20, 70% CL = 60/0-24%) was significantly different (p < 0.05 by chi square) from the mortality for Group III (44%, 12/27, 70% CL = 34%-55%). The average age of hospital survivors at operation was 10.4 ± 1.98 weeks (± SEM), whereas those dying averaged 5.3 ± 1.17 weeks. Although these data were suggestive of difference, statistical analysis was not
Volume 88 Number 6
Coarctation of aorta
December. 1984
10 1 5
100 20 90
17
1
1
_.I
1
20
± S.L
10
O+---.----.--,-.-----.----.-----,,-.-----.----.-----,r--.---o----.-----,--.---o----.--, o 2 3 4 5 6 7 8 9 W n u u ~ ~ ~ V ~ ~ Years After Operation
Fig. 2. Actuarial survival following coarctation repair in the first year of life. 0, Groups 1 and II. III.
significant. Likewise, body surface area was not significantly different between those that died and those that survived. The mortality rates among the three groups are presented in Table I. Two patients in Group I died. One patient died on the second postoperative day, and autopsy demonstrated partial thrombosis of the aorta at the repair site. The other patient had Turner's syndrome and developed exsanguinating hemorrhage from the chest tube while in the intensive care unit. Emergency thoracotomy failed to disclose a bleeding point and the infant died. The single death in Group II occurred in an infant who had pulmonary artery banding performed at the repair of the coarctation. This infant had severe congestive failure and cardiac arrhythmias preoperatively with episodes of bradycardia and was receiving antibiotic therapy for a gram-negative pneumonia at the time of operation. Mortality was highest in Group III, as might be expected. Two of the deaths resulted from ventricular fibrillation during the operation. Additionally, one patient died of a medication error the evening after the operation. Five others died of heart failure with low cardiac output syndrome up to 6 days postoperatively. Four patients in this group underwent subsequent definitive repair during the same hospitalization for intractable congestive heart failure. Two of the four died
~,
Group
Table V. Late results of coarctation repair in infants less than 1 year of age Good: Arm/leg gradient < 20 mm Hg* Poor: Arm/leg gradient ~ 20 mm Hgt 'One infant continued to have hypertension despite absence of an arm/leg pressure differential. tThree patients had hypertension.
at the time of the second operation. The third patient died of low cardiac output the following day. The fourth patient died of pneumonia 4 weeks after repair of congenital mitral incompetence. Two of the 12 patients in Group III undergoing only coarctation resection required subsequent pulmonary artery banding 1 month and 5 months postoperatively. The latter patient subsequently underwent closure of multiple ventricular septal defects 3 years after the pulmonary artery banding procedure. Both patients are alive and doing well, with the former patient awaiting a further operation. Postoperative complications occurred in nine patients, and three patients required reoperation on this basis. In one patient, a lymph fistula with chylothorax failed to resolve with dietary manipulation and chest tube drainage. Subsequent thoracotomy and ligation of the lymphatic vessel resolved the problem. A second patient had
The Journal of Thoracic and Cardiovascular Surgery
1016 Harlan et al.
100
O+----.---,----r----,r-.--.----.--.-----r-r-.------.---,----r----,r-.--.----.--.----,
o
1
2
3
•
5
6
7
89m
"
U
Years After Operation
U
~
~
~
u
~
~
~
Fig. 3. Probability of freedom from recoarctation in infants undergoing repair in the first year of life. • , Polypropylene suture. ...., Silk suture.
a large left pleural effusion and underwent thoracotomy for a presumed hemothorax. The third patient had thrombosis of the right common femoral artery at the site of the previous cardiac catheterization and required a thrombectomy. Other complications included one case of pneumonia and one case of seizures following closure of a ventricular septal defect with circulatory arrest at the time of coarctation repair. One patient had a superficial wound infection that resolved with local care and antibiotics. Two patients had renal failure. One case was mild, but the second patient required peritoneal dialysis, and the infant died on the sixth postoperative day of continued low cardiac output. One patient developed paraplegia following a primary one-stage repair of ventricular septal defect and coarctation. Femoral pulse quality that was judged as "good" in the early postoperative period was not necessarily a good indicator of a satisfactory result. Seven of the 31 patients with "good" femoral pulses early after the operation died during the hospital period. Inadequate pulse quality, on the other hand, was associated with poor results. Four patients had "fair" or "poor" femoral pulses recorded early postoperatively, and two of these patients died. Neither of the two survivors subsequently had a good result and both had an increased arm/leg pressure gradient. Thirty-two patients were available for follow-up an average of 54.7 ± 10.38 months (range 4 to 240 months) postoperatively. One patient died 7 months
after the operation of severe congestive heart failure. This patient had a hypoplastic left heart and transposition and was not considered a candidate for a further operation. Another patient underwent placement of a left ventricle-aorta conduit for severe subvalvular aortic stenosis 3Y2 years after the coarctation repair. Catheterization revealed no gradient from the ascending to descending aorta. Twenty-four patients were identified as having a good result, meaning an arm/leg pressure gradient of less than 20 mm Hg by the Doppler technique. One patient had no arm/leg gradient but continued to have hypertension in the follow-up period. Seven patients were identified as having poor results (Table V). These seven patients had important arm/leg gradients, and three of this group had associated hypertension. All seven of the patients with poor results have had repeat catheterization studies based on Doppler assessment of the arm/leg blood pressure gradient. Catheterization data confirmed important gradients in all. Two of the seven patients with recurrent coarctation (arm/ leg gradients >20 mm Hg) had reoperation. One patient had done well 51 months after re-resection and end-to-end anastomosis. The second patient continued to have hypertension despite a Dacron patch angioplasty across the recurrent coarctation. At a third operation, a bypass graft from the ascending aorta to the supraceliac aorta relieved hypertension. The five other patients have not yet had reoperation. In five of the seven the
Volume 88 Number 6 December, 1984
anastomosis was made with silk suture, and in only two patients with recurrent coarctation was the anastomosis made with fine polypropylene suture. The cumulative survival rate of Groups I and II is compared to that of Group III in Fig. 2. After the initial hospital deaths, there were no late deaths in Groups I and II. The 10 year actuarial survival rate of 50% in Group III patients is evidence that, even with their more severe cardiac disease, satisfactory long-term results may be achieved for hospital survivors. The actuarial incidence of freedom from important recurrent coarctation (arm/leg gradient <20 mm Hg) is shown in Fig. 3 for the entire group. There was a marked difference when silk or [me polypropylene suture was used for the anastomosis. Actuarial incidence of freedom from recurrent coarctation in the group with silk sutures was 57% at 5 years and 44% at 10 years. At the same intervals, the probability of a good result in the group with fine polypropylene sutures was 91%.
Discussion Repair of coarctation of the aorta in infancy continues to be an important surgical problem. Patients requiring operation in this age group are all seriously compromised with congestive heart failure prior to operation, manifest by frank cardiac decompensation or by failure of growth and weight gain. Coarctation of the aorta may be repaired with an acceptable mortality in infancy, with results that have improved in recent years. Tawes and associates' reported that the risk of hospital death had declined to 51% for the period 1963 to 1967 from a rate of 80% in their patient group from 1953 to 1962. Macmanus and colleagues'? reported a 31% operative mortality in a series of 44 infants less than 3 months of age undergoing repair of coarctation. Overall mortality in their series was 50% when a mean follow-up of 3.5 years was included. Thus, subsequent operative intervention for unrelieved congestive heart failure was attendant with an important mortality rate. Lerberg and co-workers" demonstrated a lOO-fold increase in operative mortality when comparing the results in infants less than 1 year to those 1 year of age or older. The former group of 95 patients had a 43% mortality, whereas in the latter group of 239 patients there was only one death (0.4%). The present study demonstrates a satisfactory mortality for repair of coarctation in infants with or without an associated ventricular septal defect. There was also no increase in mortality in the group of infants having closure of ventricular septal defect at the time of coarctation repair. The actuarial survival of these two
Coarctation of aorta 1 0 I 7
groups demonstrated a continued satisfactory course. It was interesting that of four patients with associated ventricular septal defect having only repair of the coarctation, two have had spontaneous closure of the intracardiac defect so that no further operation was required. Thus, present policy for this combined defect is to repair the coarctation only as the initial operative intervention and to intervene to close the ventricular septal defect as the clinical course dictates. Our own series demonstrates that operative mortality is high in the group of patients with complex cardiac anomalies. Operative death related to coarctation repair occurred in eight of the 27 patients in Group III (30%). An additional four patients died after further required operations for associated intracardiac defects causing continued severe congestive heart failure during the same hospitalization as the coarctation repair. These deaths resulted in an overall mortality of 44% and emphasize the marginal cardiac reserve in this group of patients. The actuarial survival rate of these infants in Group III with complex defects demonstrates a satisfactory course for those patients surviving the initial hospitalization (one late death at 7 months). Subsequently staged correction of associated cardiac defects after coarctation repair is usually well tolerated. The actuarial analysis showing 91% incidence of freedom from recurrent coarctation with follow-up to 10 years in this series demonstrates the adequacy of the current end-to-end anastomosis technique. In 24 of the 31 patients available for late follow-up, the anastomosis was performed with fine polypropylene suture. Twentytwo of these patients had good results, with an arm/leg gradient less than 20 mm Hg. In 19 of the 24 patients, 7-0 polypropylene suture was used, and in five of them, 6-0 polypropylene was used to construct the anastomosis. The remaining seven of the 31 patients had the anastomosis performed with 5-0 silk, and only two of the seven have had a good result on long-term follow-up. Ideally, there should be no arm/leg pressure differential following coarctation repair. A gradient often does exist after repair by end-to-end anastomosis, but a pressure differential of less than 20 mm Hg is usually considered compatible with a good result. Certainly a postrepair gradient of 20 mm Hg or more is a surgical failure whether or not hypertension is present. Pressure gradients are accentuated by exercise, but little is known regarding long-term prognosis of exercise-induced arm/ leg pressure gradients. Thus, some caution must be observed in interpreting the results of this or (' «er studies in which the gradient is determined at rest. Indeed, Fripp and associates" reported on a grot <' of eight children having subclavian flap repair in the first
1018
Harlan et al.
year of life, and the mean resting arm/leg gradient was 17 ± 12 mm Hg. Three of the eight had resting arm/leg gradients of 26, 26, and 38 mm Hg. Recently, the subclavian flap technique has been advocated as the procedure of choice for coarctation repair in infants. 2.7. 8 Waldhausen and co-workers" reported no operative deaths in nine patients under 1 year of age undergoing coarctation repair without major cardiac anomalies. Hamilton and colleagues7 have an extensive experience with this technique and reported an overall mortality of 24% in 45 infants less than 6 months of age, with no deaths in the 19 infants without major intracardiac anomalies. These excellent results have led to the conclusion that the flap technique has favorably affected mortality. Improved operative results seen over the past decade, however, are probably related to many factors in addition to the manner or technique of operative repair. Improved preparation of the infant and perioperative management would seem to have contributed importantly to improved results. Although complete relief of aortic obstruction is likely the most important factor in achieving a successful result, it does not seem appropriate to conclude that this can best be achieved by angioplasty techniques, as these data from this series indicate that end-to-end anastomosis can also achieve good mortality results and good long-term relief of aortic obstruction. The technique of subclavian flap angioplasty necessarily allows abnormal aortic tissue to remain, as many of these infants have an associated patent ductus arteriosus. Late follow-up of patch grafting with Dacron by Bergdahl and Ljungqvist" showed aneurysmal development on the wall opposite to the patch. The same may not be true for the subclavian flap, but longer follow-up is necessary. Present data of patients undergoing subclavian flap angioplasty demonstrates that residual aortic obstruction occurs. Hamilton and associates' reported weak femoral pulses in two of 27 survivors (7.4%), but arm/leg gradients were not given in the study. Thibault, Sperling, and Gazzaniga" reported a 20% incidence of important recoarctation in a group of infants less than 1 year of age undergoing subclavian flap angioplasty when followed an average of 22 months postoperatively. The incidence of recoarctation may be less with current subclavian flap technique when compared to previous studies using end-to-end anastomosis, as suggested by Pierce and Waldhausen." The late actuarial incidence of important recoarctation with the subclavian flap angioplasty method is not yet known but likely will show very good results based on present early follow-up studies. The 91% 10 year probability of freedom from
The Journal of Thoracic and Cardiovascular Surgery
recurrence using end-to-end anastomosis with fme polypropylene in this series compares favorably to other reports in the literature to date and suggests that abandonment of the traditional technique for the flap method of repair is not essential at present. We suspect that the good results are related to use of 7-0 polypropylene suture, which probably fractures to allow growth of the aorta, so as not to inhibit expansion of the aortic circumference. Perhaps current flap angioplasty techniques will share this mechanism, but in this procedure, good results must necessarily come at the expense of sacrificing a normal arterial blood flow pathway to the left arm with removal of an important collateral route should coarctation recur. New absorbable monofilament suture may be the next advance toward total prevention of recoarctation. Myers and associates," studying growing pigs subjected to anastomosis of the abdominal aorta with polydiaxanone suture, observed no late stenosis at 6 months and no inherent weakness of the anastomotic area when tested at an intraluminal pressure to 300 mm Hg. The anastomotic areas grew well, and relative stenosis was encountered less often the later the anastomosis was studied because of absorption of the suture material. Use of an absorbable monofilament suture for creation of a satisfactory end-to-end anastomosis while preserving growth potential of the aorta would seem to be the optimal method hemodynamically. This method would preserve the left subclavian artery and thereby eliminate the possibility of differential left arm growth rate, as reported by Todd and colleagues." These authors found a 1 to 2 em decrease in left arm length in all 10 patients evaluated from 2 to 9 years after subclavian flap angioplasty. Also, the threat of ischemic injury to the brachial plexus, as reported by Lawless and associates,19 would not be present. We gratefully acknowledge the help of Thomas O'Gorman, M.S., and David A. Gosse, B.S., in the statistical and graphic analysis, and Jacqueline J. Hartling for the preparation of the manuscript. REFERENCES Crafoord C, Nylin G: Congenital coarctation of the aorta and its surgical treatment. J THORAC SURG 14:347-361, 1945 2 Williams WG, Shindo G, Trusler GA, Dische MR, Olley PM: Results of repair of coarctation of the aorta during infancy. J THORAC CARDIOVASC SURG 79:603-608, 1980 3 Tawes RL, Aberdeen E, Waterston DJ, Bonham-Carter RE: Coarctation of the aorta in infants and children. A review of 333 operative cases, including 179 infants. Circulation 39, 40:Suppl 1:173-184, 1969
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4 Hartmann AF, Goldring D, Hernandez A, Behrer MR, Schad N, Ferguson T, Burford T: Recurrent coarctation of the aorta after successful repair in infancy. Am J Cardiol 25:405-410, 1970 5 Pelletier C, Davignon A, Ethier MF, Stanley P: Coarctation of the aorta in infancy. J THORAC CARDIOVASC SURG 57:171-179,1969 6 Waldhausen JA, Nahrwold DL: Repair of coarctation of the aorta with a subclavian flap. J THORAC CCARDIOVASC SURG 51:532-533, 1966 7 Hamilton OJ, 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 8 Bergdahl LA, Blackstone nr, 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 9 Kaplan E, Meier P: Non-parametric estimation from incomplete observations. Am Stat Assoc J 53:457-481, 1958 10 Macmanus Q, Starr A, Lambert LE, Grunkemeier G: Correction of aortic coarctation in neonates. Mortality and late results. Ann Thorac Surg 24:544-549, 1977. II Lerberg DB, Hardesty RL, Siewers RD, Zuberbuhler JR, Bahnson HT: Coarctation of the aorta in infants and children: 25 years of experience. Ann Thorac Surg 33: 159170, 1982 12 Fripp RR, Whitman V, Werner JC, Nicholas GG,
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Waldhausen JA: Blood pressure response to exercise in children following the subclavian flap procedure for coarctation of the aorta. J THORAC CARDIOVASC SURG 85:682685, 1983 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 Bergdahl L, Ljungqvist A: Long-term results after repair of coarctation of the aorta by patch grafting. J THORAC CARDIOVASC SURG 80: 177-181, 1981 Thibault WN, Sperling DR, Gazzaniga AB: Subclavian artery patch angioplasty. Arch Surg 110:1095-1098, 1975 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 Meyers JL, Waldhausen JA, Pae WE, Abt AB, Prophet GA, Pierce WS: Vascular anastomoses in growing vessels. The use of absorbable sutures. Ann Thorac Surg 34:529537, 1982 Todd PJ, Dangerfield PH, Hamilton OJ, Wilkinson JL: Late effect on the left upper limb of subclavian flap aortoplasty. J THORAC CARDIOVASC SURG 85:678-681, 1983 Lawless CE, Sapsford RN, Pallis C, Hallidie-Smith KA: Ischemic injury to the brachial plexus following subclavian flap aortoplasty. J THORAC CARDIOVASC SURG 84:779-782, 1982
THoRAc CARDIOVASC SURG
88:1012-1019, 1984
Coarctation of the aorta in infants Repair of coarctation of the aorta in the first year of life by resection and end-to-end anastomosis has been reported to have a high rate of recurrence, and recent studies favor angioplasty techniques. Forty-sevenconsecutive infants less than 1 year of age whowereoperated upon overa 20 year periodwere analyzed. The hospital mortality was analyzed in three groups: Group I-two of 11 patients (18%) with coarctation; Group II-one of nine patients (11 %) with coarctation and ventricularseptal defect; Group m-12 of 27 patients (44%) with coarctation and major intracardiac anomalies.There was no difference in age or body surface area betweensurvivors and nonsurvivors. Repair was pedormed by a resection and end-to-end anastomosis to the distal aortic arch in 43 and by patch angioplastyin four. Anastomosiswas pedormed with >0 silk suture prior to 1972. Since then, 7-0 polypropylene suture has generally been used. Arm/leg pressure gradient was assessed at rest by the Doppler technique in 31 long-term survivors of the end-to-end anastomosis technique; 24 of them had polypropylene suture used and seven bad silk suture. Recurrence of coarctation was defmed as arm/leg gradient >- 20 mm Hg. Actuarial freedomfrom recurrence at 5 and 10 years was 91 % in the polypropylene group versus57% and 44% in the silk group. Good long-term results with low incidence of recurrent coarctation achieved by end-to-end anastomosis with fine polypropylene suture justify continued use of this technique in preference to angioplasty techniques, whichsacrifice the left subclavian artery or introduce prosthetic materials. Techniqueschosen for coarctation repair should be compared with current operative techniques and not older studies. John L. Harlan, M.D., Donald B. Doty, M.D., * Berkeley Brandt III, M.D., and Johann L. Ehrenhaft, M.D., Iowa City, Iowa
Coarctation of the aorta has been a correctable surgical lesion for nearly 40 years. Since the pioneering operation of Crafoord and Nylin,' resection of coarctation of the aorta and end-to-end anastomosis has been the most widely practiced surgical method. Recurrence of the coarctation, defined as a resting gradient of 20 mm Hg or greater in blood pressure measured in the arm and leg, seems to be an important problem with this surgical technique, especially when the repair is done in the first year of life. Williams and associates' found the actuarial incidence of recurrence of coarctation to be 42% at 5 years in a group of infants having repair of coarctation of the aorta at less than 1 year of age. Tawes From the Division of Thoracic and Cardiovascular Surgery, Department of Surgery, University of Iowa Hospitals and Clinics, Iowa City, Iowa. Received for publication Aug. 31, 1983. Accepted for publication Jan. 26, 1984. Address for reprints: Division of Thoracic and Cardiovascular Surgery, University of Iowa Hospitals and Clinics, Iowa City, Iowa 52242. *Current address: Donald B. Doty, M.D., 324 Tenth Ave., Salt Lake City, Utah 84103.
1012
and associates' reported an alarming 14 of 20 patients with recurrent coarctation when the repair was performed in the first 3 months of life. The cause of recurrent coarctation is obscure. The various theories postulated have included inadequate growth of the anastomosis and actual residual coarctation at the time of repair.t' In order to alleviate the former problem, the anterior row of sutures has traditionally been interrupted to permit growth of the aorta at the anastomosis.The latter problem, which represents inadequate repair, has been addressed by techniques that assure the widest possible initial anastomosis. The subclavian flap technique as proposed by Waldhausen and Nahrwold," in which the left subclavian artery is turned down as a flap patch to widen the unresected coarcted segment of aorta, has recently become popular. This has been advocated by some authors as the method of choice in repair of coarctation of the aorta in
infants." 7,8
This study reviews a 20 year experiencewith repair of coarctation of the aorta, which has been accomplished in most cases by resection and creation of the largest possible end-to-end anastomosis, in a group of infants less than 1 year of age.
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Coarctation of aorta
December, 1984
Table I. Anatomic distribution in infants less
Table II. Infants less than 1 year of age with
than 1 year of age undergoing coarctation repair
coarctation and major cardiac anomalies
Hospital deaths* Group Group I: Coarctation Group II: Coarctation with isolated VSD Group III: Coarctation with major cardiac anomalies
No. II
No.
I% I
70% CL
9
2 I
18 II
5%-32% 1%-23%
27
12
44
34%-55%
47
15
32
250/0-39%
Legend: CL, Confidencelimits.
• Hospital death includes operative mortality and mortality associated with second procedureduring same hospitalization.
Patients and methods The hospital records of all patients less than 1 year of age undergoing repair of coarctation of the aorta at The University of Iowa Hospitals for the 20 year period from June, 1962, to June, 1982, were reviewed. Forty-seven patients were identified for analysis. Sixteen of these had mild transverse arch hypoplasia on cineangiogram. Eight other patients with marked hypoplasia of the transverse arch and coarctation or aortic atresia and coarctation were not included. The patients were divided into three categories (Table I): Group I-patients with isolated coarctation of the aorta and without major intracardiac anomalies; Group II-patients with coarctation and ventricular septal defect; and Group 111patients with coarctation and associated major intracardiac anomalies (Table 11). Patent ductus arteriosus was commonly associated with coarctation of the aorta in all three groups. Seven patients in Group I, seven patients in Group II, and 20 patients in Group III had closure of the ductus arteriosus, when present, at the time of repair of the coarctation. All patients had congestive heart failure prior to operation. Two patients had central nervous system irritability manifest by seizures preoperatively, and one patient had severe myocardial failure with hypotension (cardiogenic shock) and respiratory failure necessitating endotracheal intubation prior to emergency operation. Forty-one patients had cardiomegaly on chest roentgenogram prior to operation, and 31 had increased pulmonary vascular markings. Electrocardiogram revealed cardiac hypertrophy in nearly all patients, with combined ventricular hypertrophy in 21, left ventricular hypertrophy in eight, and right ventricular hypertrophy in 13. One infant had dextrocardia, making interpretation of hypertrophy criteria obscure, and one had left axis deviation. Only two patients had normal electrocardiograms.
Congenital aortic stenosis Subvalvular Valvular Congenital aortic stenosis and infundibular pulmonic stenosis Congenital mitral incompetence With VSD VSD and ASD MUltiple VSDs Single ventricle with transposition Transposition With VSD and ASD With hypoplastic right heart With hypoplastic left heart With dextrocardia, VSD, and ASD Double-outlet right ventricle Totals
EJ 6
10 1 3
Hospital deaths 3
I 5
3 4 4 2
I 3
6
3
3 I I I
I 27
I 12 (44%) (70% CL 340/0-55%)
Legend: VSD, Ventricular septal defect. ASD, Atrial septal defect.
Cardiac catheterization. Three of the 47 patients were operated upon prior to the use of cardiac catheterization. Routinely, catheterization included' oximetry, pressure determinations, ventriculography, and aortography. In 20 patients the pressure gradient across the coarctation was measured. In the remaining 24 patients the diagnosis was confirmed by cineangiogram, as the coarctation did not allow retrograde passage of the catheter from the descending aorta. Operative technique. The operation was performed in all patients through a posterolateral thoracotomy on the left side. The chest was entered through the intercostal space or bed of the unresected fourth rib. The aorta was completely mobilized, including the distal arch, the left subclavian artery, and the upper half of the descending thoracic aorta. Intercostal arteries were sacrificed only as required for adequate mobilization and control of the anastomotic site. The ductus arteriosus was mobilized and ligated when present. Vascular occlusiveclamps were placed across the distal portion of the arch near or across the origin of the left common carotid artery (occasionally proximal to it) and the upper descending thoracic aorta distal to the coarctation (Fig. 1, A). The stenotic segment was excised in a fashion to achieve maximal aortic diameter. The proximal incision was made across the aorta just distal to the left subclavian artery and extended into the lateral wall of the left subclavian artery or more proximally into the inferior aspect of the distal aortic arch. The distal
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The Journal of Thoracic and Cardiovascular Surgery
Harlan et al.
Table IV. Management of infants less than 1 year of age with coarctation and major cardiac anomalies (Group III) Hospital deaths
Coarctation repair only Coarctation repair and PA banding Coarctation repair and one-stage primary repair Coarctation repair and two-stage repair during same hospitalization Totals
Fig. 1. Technique of operative repair. Proximal incision extends from undersurface of the transverse arch of the aorta to the lateral wall of the left subclavian artery. (See text for details.)
Table m. Management of infants less than 1 year of age with coarctation and isolated VSD (Group II) Hospital deaths
Coarctation Coarctation Coarctation one-stage Totals
o
repair only repair and PA banding repair and primary VSD repair
1
o 9
1 (11%) (70% CL 1%-23%)
Legend: VSD, Ventricular septal defect. PA, Pulmonary artery.
incision was made into the wide portion of the upper thoracic aorta at an appropriate 30 to 40 degree angle to match the orientation of the proximal incision and assure the widest possible aortic diameter for anastomosis (Fig. 1, B). The anastomosis was performed with a fme running suture on the posterior aspect, and the anterior row of sutures was interrupted to allow for growth of the aorta (Fig. 1, C). Prior to 1972, 5-0 silk suture was used, and subsequently anastomoses were performed with 7-0 or 6-0 polypropylene suture. In four patients the coarctation was repaired by patch grafting with the excised subclavian artery, which was split longitudinally for an aortoplasty that extended from the left common carotid artery through the coarctation to the upper descending thoracic aorta. This method is no longer used. Pulmonary artery banding was performed simultaneously with repair of the coarctation in only one of the
4
27
4
12 (44%) (70% CL 340/0-55%)
nine patients who had coarctation associated with isolated ventricular septal defect. Four of these nine patients had primary one-stage repair of both defects. Coarctation resection and anastomosis was followed by repositioning for a median sternotomy for closure of the ventricular septal defect at the same operation (Table III). In seven of the patients with coarctation associated with other complex lesions, pulmonary artery banding was performed in addition to the coarctation repair. Only three of the 27 patients in this group, however, had a primary one-stage repair (Table IV). Four patients subsequently required staged repair of associated intracardiac anomalies during the same hospitalization for intractable congestive heart failure from 3 to 8 weeks after coarctation repair, and all four subsequently died during hospitalization. Statistical methods. The data were arranged in contingency tables. Analysis was performed with a two-sample t test or chi square test where applicable. The data for survival and recurrence were analyzed by the actuarial method of Kaplan and Meier." Mean values are expressed with standard error of mean and proportions are shown with their 70% confidence limits (CL). Results There was no statistical difference in hospital mortality between Group I (18%) and Group II (11%). The combined mortality for these two groups (15%, 3/20, 70% CL = 60/0-24%) was significantly different (p < 0.05 by chi square) from the mortality for Group III (44%, 12/27, 70% CL = 34%-55%). The average age of hospital survivors at operation was 10.4 ± 1.98 weeks (± SEM), whereas those dying averaged 5.3 ± 1.17 weeks. Although these data were suggestive of difference, statistical analysis was not
Volume 88 Number 6
Coarctation of aorta
December. 1984
10 1 5
100 20 90
17
1
1
_.I
1
20
± S.L
10
O+---.----.--,-.-----.----.-----,,-.-----.----.-----,r--.---o----.-----,--.---o----.--, o 2 3 4 5 6 7 8 9 W n u u ~ ~ ~ V ~ ~ Years After Operation
Fig. 2. Actuarial survival following coarctation repair in the first year of life. 0, Groups 1 and II. III.
significant. Likewise, body surface area was not significantly different between those that died and those that survived. The mortality rates among the three groups are presented in Table I. Two patients in Group I died. One patient died on the second postoperative day, and autopsy demonstrated partial thrombosis of the aorta at the repair site. The other patient had Turner's syndrome and developed exsanguinating hemorrhage from the chest tube while in the intensive care unit. Emergency thoracotomy failed to disclose a bleeding point and the infant died. The single death in Group II occurred in an infant who had pulmonary artery banding performed at the repair of the coarctation. This infant had severe congestive failure and cardiac arrhythmias preoperatively with episodes of bradycardia and was receiving antibiotic therapy for a gram-negative pneumonia at the time of operation. Mortality was highest in Group III, as might be expected. Two of the deaths resulted from ventricular fibrillation during the operation. Additionally, one patient died of a medication error the evening after the operation. Five others died of heart failure with low cardiac output syndrome up to 6 days postoperatively. Four patients in this group underwent subsequent definitive repair during the same hospitalization for intractable congestive heart failure. Two of the four died
~,
Group
Table V. Late results of coarctation repair in infants less than 1 year of age Good: Arm/leg gradient < 20 mm Hg* Poor: Arm/leg gradient ~ 20 mm Hgt 'One infant continued to have hypertension despite absence of an arm/leg pressure differential. tThree patients had hypertension.
at the time of the second operation. The third patient died of low cardiac output the following day. The fourth patient died of pneumonia 4 weeks after repair of congenital mitral incompetence. Two of the 12 patients in Group III undergoing only coarctation resection required subsequent pulmonary artery banding 1 month and 5 months postoperatively. The latter patient subsequently underwent closure of multiple ventricular septal defects 3 years after the pulmonary artery banding procedure. Both patients are alive and doing well, with the former patient awaiting a further operation. Postoperative complications occurred in nine patients, and three patients required reoperation on this basis. In one patient, a lymph fistula with chylothorax failed to resolve with dietary manipulation and chest tube drainage. Subsequent thoracotomy and ligation of the lymphatic vessel resolved the problem. A second patient had
The Journal of Thoracic and Cardiovascular Surgery
1016 Harlan et al.
100
O+----.---,----r----,r-.--.----.--.-----r-r-.------.---,----r----,r-.--.----.--.----,
o
1
2
3
•
5
6
7
89m
"
U
Years After Operation
U
~
~
~
u
~
~
~
Fig. 3. Probability of freedom from recoarctation in infants undergoing repair in the first year of life. • , Polypropylene suture. ...., Silk suture.
a large left pleural effusion and underwent thoracotomy for a presumed hemothorax. The third patient had thrombosis of the right common femoral artery at the site of the previous cardiac catheterization and required a thrombectomy. Other complications included one case of pneumonia and one case of seizures following closure of a ventricular septal defect with circulatory arrest at the time of coarctation repair. One patient had a superficial wound infection that resolved with local care and antibiotics. Two patients had renal failure. One case was mild, but the second patient required peritoneal dialysis, and the infant died on the sixth postoperative day of continued low cardiac output. One patient developed paraplegia following a primary one-stage repair of ventricular septal defect and coarctation. Femoral pulse quality that was judged as "good" in the early postoperative period was not necessarily a good indicator of a satisfactory result. Seven of the 31 patients with "good" femoral pulses early after the operation died during the hospital period. Inadequate pulse quality, on the other hand, was associated with poor results. Four patients had "fair" or "poor" femoral pulses recorded early postoperatively, and two of these patients died. Neither of the two survivors subsequently had a good result and both had an increased arm/leg pressure gradient. Thirty-two patients were available for follow-up an average of 54.7 ± 10.38 months (range 4 to 240 months) postoperatively. One patient died 7 months
after the operation of severe congestive heart failure. This patient had a hypoplastic left heart and transposition and was not considered a candidate for a further operation. Another patient underwent placement of a left ventricle-aorta conduit for severe subvalvular aortic stenosis 3Y2 years after the coarctation repair. Catheterization revealed no gradient from the ascending to descending aorta. Twenty-four patients were identified as having a good result, meaning an arm/leg pressure gradient of less than 20 mm Hg by the Doppler technique. One patient had no arm/leg gradient but continued to have hypertension in the follow-up period. Seven patients were identified as having poor results (Table V). These seven patients had important arm/leg gradients, and three of this group had associated hypertension. All seven of the patients with poor results have had repeat catheterization studies based on Doppler assessment of the arm/leg blood pressure gradient. Catheterization data confirmed important gradients in all. Two of the seven patients with recurrent coarctation (arm/ leg gradients >20 mm Hg) had reoperation. One patient had done well 51 months after re-resection and end-to-end anastomosis. The second patient continued to have hypertension despite a Dacron patch angioplasty across the recurrent coarctation. At a third operation, a bypass graft from the ascending aorta to the supraceliac aorta relieved hypertension. The five other patients have not yet had reoperation. In five of the seven the
Volume 88 Number 6 December, 1984
anastomosis was made with silk suture, and in only two patients with recurrent coarctation was the anastomosis made with fine polypropylene suture. The cumulative survival rate of Groups I and II is compared to that of Group III in Fig. 2. After the initial hospital deaths, there were no late deaths in Groups I and II. The 10 year actuarial survival rate of 50% in Group III patients is evidence that, even with their more severe cardiac disease, satisfactory long-term results may be achieved for hospital survivors. The actuarial incidence of freedom from important recurrent coarctation (arm/leg gradient <20 mm Hg) is shown in Fig. 3 for the entire group. There was a marked difference when silk or [me polypropylene suture was used for the anastomosis. Actuarial incidence of freedom from recurrent coarctation in the group with silk sutures was 57% at 5 years and 44% at 10 years. At the same intervals, the probability of a good result in the group with fine polypropylene sutures was 91%.
Discussion Repair of coarctation of the aorta in infancy continues to be an important surgical problem. Patients requiring operation in this age group are all seriously compromised with congestive heart failure prior to operation, manifest by frank cardiac decompensation or by failure of growth and weight gain. Coarctation of the aorta may be repaired with an acceptable mortality in infancy, with results that have improved in recent years. Tawes and associates' reported that the risk of hospital death had declined to 51% for the period 1963 to 1967 from a rate of 80% in their patient group from 1953 to 1962. Macmanus and colleagues'? reported a 31% operative mortality in a series of 44 infants less than 3 months of age undergoing repair of coarctation. Overall mortality in their series was 50% when a mean follow-up of 3.5 years was included. Thus, subsequent operative intervention for unrelieved congestive heart failure was attendant with an important mortality rate. Lerberg and co-workers" demonstrated a lOO-fold increase in operative mortality when comparing the results in infants less than 1 year to those 1 year of age or older. The former group of 95 patients had a 43% mortality, whereas in the latter group of 239 patients there was only one death (0.4%). The present study demonstrates a satisfactory mortality for repair of coarctation in infants with or without an associated ventricular septal defect. There was also no increase in mortality in the group of infants having closure of ventricular septal defect at the time of coarctation repair. The actuarial survival of these two
Coarctation of aorta 1 0 I 7
groups demonstrated a continued satisfactory course. It was interesting that of four patients with associated ventricular septal defect having only repair of the coarctation, two have had spontaneous closure of the intracardiac defect so that no further operation was required. Thus, present policy for this combined defect is to repair the coarctation only as the initial operative intervention and to intervene to close the ventricular septal defect as the clinical course dictates. Our own series demonstrates that operative mortality is high in the group of patients with complex cardiac anomalies. Operative death related to coarctation repair occurred in eight of the 27 patients in Group III (30%). An additional four patients died after further required operations for associated intracardiac defects causing continued severe congestive heart failure during the same hospitalization as the coarctation repair. These deaths resulted in an overall mortality of 44% and emphasize the marginal cardiac reserve in this group of patients. The actuarial survival rate of these infants in Group III with complex defects demonstrates a satisfactory course for those patients surviving the initial hospitalization (one late death at 7 months). Subsequently staged correction of associated cardiac defects after coarctation repair is usually well tolerated. The actuarial analysis showing 91% incidence of freedom from recurrent coarctation with follow-up to 10 years in this series demonstrates the adequacy of the current end-to-end anastomosis technique. In 24 of the 31 patients available for late follow-up, the anastomosis was performed with fine polypropylene suture. Twentytwo of these patients had good results, with an arm/leg gradient less than 20 mm Hg. In 19 of the 24 patients, 7-0 polypropylene suture was used, and in five of them, 6-0 polypropylene was used to construct the anastomosis. The remaining seven of the 31 patients had the anastomosis performed with 5-0 silk, and only two of the seven have had a good result on long-term follow-up. Ideally, there should be no arm/leg pressure differential following coarctation repair. A gradient often does exist after repair by end-to-end anastomosis, but a pressure differential of less than 20 mm Hg is usually considered compatible with a good result. Certainly a postrepair gradient of 20 mm Hg or more is a surgical failure whether or not hypertension is present. Pressure gradients are accentuated by exercise, but little is known regarding long-term prognosis of exercise-induced arm/ leg pressure gradients. Thus, some caution must be observed in interpreting the results of this or (' «er studies in which the gradient is determined at rest. Indeed, Fripp and associates" reported on a grot <' of eight children having subclavian flap repair in the first
1018
Harlan et al.
year of life, and the mean resting arm/leg gradient was 17 ± 12 mm Hg. Three of the eight had resting arm/leg gradients of 26, 26, and 38 mm Hg. Recently, the subclavian flap technique has been advocated as the procedure of choice for coarctation repair in infants. 2.7. 8 Waldhausen and co-workers" reported no operative deaths in nine patients under 1 year of age undergoing coarctation repair without major cardiac anomalies. Hamilton and colleagues7 have an extensive experience with this technique and reported an overall mortality of 24% in 45 infants less than 6 months of age, with no deaths in the 19 infants without major intracardiac anomalies. These excellent results have led to the conclusion that the flap technique has favorably affected mortality. Improved operative results seen over the past decade, however, are probably related to many factors in addition to the manner or technique of operative repair. Improved preparation of the infant and perioperative management would seem to have contributed importantly to improved results. Although complete relief of aortic obstruction is likely the most important factor in achieving a successful result, it does not seem appropriate to conclude that this can best be achieved by angioplasty techniques, as these data from this series indicate that end-to-end anastomosis can also achieve good mortality results and good long-term relief of aortic obstruction. The technique of subclavian flap angioplasty necessarily allows abnormal aortic tissue to remain, as many of these infants have an associated patent ductus arteriosus. Late follow-up of patch grafting with Dacron by Bergdahl and Ljungqvist" showed aneurysmal development on the wall opposite to the patch. The same may not be true for the subclavian flap, but longer follow-up is necessary. Present data of patients undergoing subclavian flap angioplasty demonstrates that residual aortic obstruction occurs. Hamilton and associates' reported weak femoral pulses in two of 27 survivors (7.4%), but arm/leg gradients were not given in the study. Thibault, Sperling, and Gazzaniga" reported a 20% incidence of important recoarctation in a group of infants less than 1 year of age undergoing subclavian flap angioplasty when followed an average of 22 months postoperatively. The incidence of recoarctation may be less with current subclavian flap technique when compared to previous studies using end-to-end anastomosis, as suggested by Pierce and Waldhausen." The late actuarial incidence of important recoarctation with the subclavian flap angioplasty method is not yet known but likely will show very good results based on present early follow-up studies. The 91% 10 year probability of freedom from
The Journal of Thoracic and Cardiovascular Surgery
recurrence using end-to-end anastomosis with fme polypropylene in this series compares favorably to other reports in the literature to date and suggests that abandonment of the traditional technique for the flap method of repair is not essential at present. We suspect that the good results are related to use of 7-0 polypropylene suture, which probably fractures to allow growth of the aorta, so as not to inhibit expansion of the aortic circumference. Perhaps current flap angioplasty techniques will share this mechanism, but in this procedure, good results must necessarily come at the expense of sacrificing a normal arterial blood flow pathway to the left arm with removal of an important collateral route should coarctation recur. New absorbable monofilament suture may be the next advance toward total prevention of recoarctation. Myers and associates," studying growing pigs subjected to anastomosis of the abdominal aorta with polydiaxanone suture, observed no late stenosis at 6 months and no inherent weakness of the anastomotic area when tested at an intraluminal pressure to 300 mm Hg. The anastomotic areas grew well, and relative stenosis was encountered less often the later the anastomosis was studied because of absorption of the suture material. Use of an absorbable monofilament suture for creation of a satisfactory end-to-end anastomosis while preserving growth potential of the aorta would seem to be the optimal method hemodynamically. This method would preserve the left subclavian artery and thereby eliminate the possibility of differential left arm growth rate, as reported by Todd and colleagues." These authors found a 1 to 2 em decrease in left arm length in all 10 patients evaluated from 2 to 9 years after subclavian flap angioplasty. Also, the threat of ischemic injury to the brachial plexus, as reported by Lawless and associates,19 would not be present. We gratefully acknowledge the help of Thomas O'Gorman, M.S., and David A. Gosse, B.S., in the statistical and graphic analysis, and Jacqueline J. Hartling for the preparation of the manuscript. REFERENCES Crafoord C, Nylin G: Congenital coarctation of the aorta and its surgical treatment. J THORAC SURG 14:347-361, 1945 2 Williams WG, Shindo G, Trusler GA, Dische MR, Olley PM: Results of repair of coarctation of the aorta during infancy. J THORAC CARDIOVASC SURG 79:603-608, 1980 3 Tawes RL, Aberdeen E, Waterston DJ, Bonham-Carter RE: Coarctation of the aorta in infants and children. A review of 333 operative cases, including 179 infants. Circulation 39, 40:Suppl 1:173-184, 1969
Volume 88 Number 6 December, 1984
4 Hartmann AF, Goldring D, Hernandez A, Behrer MR, Schad N, Ferguson T, Burford T: Recurrent coarctation of the aorta after successful repair in infancy. Am J Cardiol 25:405-410, 1970 5 Pelletier C, Davignon A, Ethier MF, Stanley P: Coarctation of the aorta in infancy. J THORAC CARDIOVASC SURG 57:171-179,1969 6 Waldhausen JA, Nahrwold DL: Repair of coarctation of the aorta with a subclavian flap. J THORAC CCARDIOVASC SURG 51:532-533, 1966 7 Hamilton OJ, 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 8 Bergdahl LA, Blackstone nr, 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 9 Kaplan E, Meier P: Non-parametric estimation from incomplete observations. Am Stat Assoc J 53:457-481, 1958 10 Macmanus Q, Starr A, Lambert LE, Grunkemeier G: Correction of aortic coarctation in neonates. Mortality and late results. Ann Thorac Surg 24:544-549, 1977. II Lerberg DB, Hardesty RL, Siewers RD, Zuberbuhler JR, Bahnson HT: Coarctation of the aorta in infants and children: 25 years of experience. Ann Thorac Surg 33: 159170, 1982 12 Fripp RR, Whitman V, Werner JC, Nicholas GG,
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Waldhausen JA: Blood pressure response to exercise in children following the subclavian flap procedure for coarctation of the aorta. J THORAC CARDIOVASC SURG 85:682685, 1983 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 Bergdahl L, Ljungqvist A: Long-term results after repair of coarctation of the aorta by patch grafting. J THORAC CARDIOVASC SURG 80: 177-181, 1981 Thibault WN, Sperling DR, Gazzaniga AB: Subclavian artery patch angioplasty. Arch Surg 110:1095-1098, 1975 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 Meyers JL, Waldhausen JA, Pae WE, Abt AB, Prophet GA, Pierce WS: Vascular anastomoses in growing vessels. The use of absorbable sutures. Ann Thorac Surg 34:529537, 1982 Todd PJ, Dangerfield PH, Hamilton OJ, Wilkinson JL: Late effect on the left upper limb of subclavian flap aortoplasty. J THORAC CARDIOVASC SURG 85:678-681, 1983 Lawless CE, Sapsford RN, Pallis C, Hallidie-Smith KA: Ischemic injury to the brachial plexus following subclavian flap aortoplasty. J THORAC CARDIOVASC SURG 84:779-782, 1982