Aortoventriculoplasty in children

Long-term results after reconstruction of the left ventricular outflow tract by aortoventriculoplasty

BACKGROUND

Aortoventriculoplasty is an established method of reconstruction of complex left ventricular outflow tract (LVOT) obstruction by insertion of a mechanical valve prosthesis after patch enlargement of the LVOT. Little data exist with respect to long-term outcome.

METHODS

Between March 1991 and June 2001, 24 patients with a median age of 10.7 (range, 2.1 to 66) years underwent aortoventriculoplasty, which was performed as a primary procedure in 4 and as a secondary intervention in 20 patients. On follow-up, all patients were restudied with an actual prospective evaluation. Data were statistically analyzed using a paired t test.

RESULTS

There was one early death from low cardiac output. Four patients had to be reoperated on for bleeding. All 23 postoperative survivors were followed up for 63 (range, 12 to 123) months. Aortic anulus size of 14 (7 to 19) mm could be significantly enlarged to a size of 24 (19 to 27) mm for insertion of a mechanical valve prosthesis (p < 0.001). Blood flow velocity across the LVOT significantly decreased to 1.8 (1.3 to 2.9) m/s (preoperative, 4.1 [2.7 to 5.8] m/s) (p < 0.001). There were no late deaths. One patient underwent late repair of a paraprosthetic leak. On follow-up, there was no hemorrhage related to anticoagulation observed, but there was one minor thromboembolic complication. Relief of LVOT obstruction and good function of the valve prostheses could be demonstrated in all patients.

CONCLUSIONS

Aortoventriculoplasty is an easily applicable, low-risk procedure for the effective relief of complex LVOT obstruction, and provides excellent long-term results.

Small aortic root in childhood: surgical options

Aortic valve replacement in the pediatric population is complicated by the often complex nature of the left ventricular outflow tract obstruction. Techniques to enlarge the annulus frequently are necessary. From 1977 to 1991, 32 children underwent an annular enlargement procedure at The Hospital for Sick Children, Toronto. During this same era, 110 children underwent a total of 138 aortic valve replacements. Eleven had the annulus enlarged with a posterior patch technique and implantation of a valve (mechanical 8, porcine heterograft 2, homograft 1) ranging from 20 to 25 mm in diameter. Twenty-two children had an anterior annular enlargement (aortoventriculoplasty) and aortic valve replacement with a valve (mechanical 8, porcine 2, homograft 12) 12 to 27 mm in diameter. One child had a posterior patch enlargement performed, followed by a second operation involving anterior annular enlargement. There was one early death in the posterior annuloplasty group and one late death due to failure of a bioprosthetic valve. There were five hospital deaths in the anterior annuloplasty group (22%; 70% confidence interval [CI], 14% to 32%) and two late deaths. Actuarial survival for the 32 children was 78% (70% CI, 70% to 86%) at 5 years and 65% (70% CI, 48% to 82%) at 10 years after repair. Younger children (age less than 1 year) had a significantly worse survival at 5 years (33%; 70% CI, 14% to 52%) than older children (88%; 70% CI, 82% to 95%). The survivors are well, and no reoperations have been necessary because of the children's outgrowing their valve.

Aortic valve prosthesis obstruction after aortoventriculoplasty: reconstruction with aortic allograft

An aortoventriculoplasty (Konno procedure) operation was performed for relief of tunnel-type subaortic stenosis using a Bjork-Shiley valve aortic prosthesis. The mechanical prosthesis thrombosed and cerebral embolism occurred when anticoagulant medication was stopped. The aortic root was successfully reconstructed with a cryopreserved aortic allograft using freehand implant technique. The cryopreserved aortic allograft is an excellent replacement device in the young adult patient in cases of failed prostheses, even in the presence of complex left ventricular outflow tract morphology or previous reconstruction operations.

Konno procedure for congenital aortic stenosis with a single coronary artery from the left coronary sinus

A right coronary artery originating from the left coronary sinus and traversing anteriorly is thought to be one of the contraindications for a Konno aortoventriculoplasty in congenital aortic stenosis because this procedure necessitates incision of the right ventricular outflow tract. The case of a 5-year-old girl with congenital aortic stenosis associated with a single coronary artery, successfully treated surgically by the Konno procedure and right coronary artery reimplantation, is reported. Preoperatively there was a pressure gradient between the left ventricle and the ascending aorta of 109 mmHg, which disappeared postoperatively. A postoperative angiography showed a patent right coronary artery.

Surgical management of congenital aortic stenosis in children and young adults

The surgical management of congenital aortic stenosis in 33 patients (age 2-20, mean 11 years) is described. The stenosis was valvular in 19 cases, subvalvular in eight and supravalvular in six. The primary procedures in valvular stenosis were valvotomy (12 cases), valve replacement (6) and exploration (1). Subvalvular stenosis was treated with resection of muscle (4), membrane (2) or both (2), and all six supravalvular lesions with patch aortoplasty. One death occurred during primary operation. Follow-up averaged 11.5 years. Of the 12 valvotomized patients, five required valve replacement after on average 10.6 years because of restenosis. Aortic regurgitation developed in six of the seven surviving patients treated for subvalvular stenosis, requiring reoperation in four. No mortality was associated with reoperation. All patients without valve replacement were reinvestigated. Of the seven with valvotomy, four had restenosis and three valves were in good condition. In supravalvular stenosis the gradients were low. Valvotomy and subvalvular resection can give effective palliation of aortic stenosis until the patient is old enough for definitive repair.

Aortic valve replacement with concomitant aortoventriculoplasty in children and young adults: long-term follow-up

Sixteen patients (9 male, 7 female) underwent aortic valve replacement (AVR) with a Konno aortoventriculoplasty at the University of Nebraska Medical Center from August, 1976, to May, 1986. There was 1 early death (6%), but no operative deaths have occurred since 1977. There was 1 late death from unknown cause 51 months postoperatively. One patient has been lost to follow-up. Long-term follow-up of 14 patients was 923 months (mean, 66 months; range, 9 to 120 months). Of the 16 patients, 12 (75%) had had previous cardiovascular procedures. A total of thirty-five operations, including the aortoventriculoplasties, were done in the 16 patients. Of the aortic valves inserted, 11 were tissue valves (Carpentier-Edwards, 10; Ionescu-Shiley, 1) and 5 were mechanical valves (St. Jude, 3; Björk-Shiley, 2). Patient age at the time of aortoventriculoplasty ranged from 2 years 3 months to 24 years (median, 11 years 8 months). Size of the aortic annulus ranged from 10 to less than 21 mm (median, 16 mm). Valves inserted ranged from 21 to 29 mm; 13 (81%) of them were 25 mm or larger. In 2 patients, degenerated tissue valves were replaced with mechanical valves after 110 and 33 months. At present, all patients are in New York Heart Association Functional Class I. One female patient married and delivered a normal child approximately five years after AVR with a Carpentier-Edwards valve plus aortoventriculoplasty; she never received anticoagulant medications. We conclude that AVR with a concomitant Konno aortoventriculoplasty can be safely performed in the pediatric and young-adult age groups with satisfactory results for up to ten years.