The Konno aortoventriculoplasty for repeat aortic valve replacement

Objective: To evaluate the outcome of aortic root augmentation by the Konno-aortoventriculoplasty technique as part of reoperative aortic valve replacement. Methods: Since 1983, 15 patients, 12 males and three females, had repeat aortic valve replacement (AVR) with concomitant Konno aortoventriculoplasty. Age ranged from 1.2 to 18 years (mean 12.5 years). The underlying anatomic diagnoses were valve and subvalvar aortic stenosis in 11, truncal valve insufficiency in one, endocarditis in one, Shone's complex in one and severe aortic insufficiency associated with a ventricular septal defect in one patient. All patients had had previous AVR. The causes for reoperation were prosthetic valve stenosis due to growth in ten and paravalvular leak in one, homograft failure in two, xenograft failure in one, and left ventricular outflow tract obstruction (LVOTO) after mitral valve replacement in one patient. The mean size of explanted prostheses was 19.2 mm (13–23 mm) while the mean size of the implanted prostheses was 24.3 mm (19–27 mm) (P<0.01). Previous aortic root enlargement had been performed in 11 patients in conjunction with AVR. The Manougian technique was used previously in two, Konno aortoventriculoplasty in eight, and both techniques in one patient. The newly implanted aortic valves were a homograft in one patient and mechanical prostheses in 14 patients. Results: There was one operative death (1 of 15 or 6.6%) in a 17.5 year old patient with previous AVR and posterior root enlargement, due to low cardiac output state. Follow-up ranged from 6 months to 17 years (mean 7.2 years). The only late death occurred in an 11.6-year-old patient due to prosthetic valve endocarditis. Two patients had complete heart block and had permanent pacemaker insertion (2 of 15 or 13.3%). One patient had pulmonary valve replacement because of combined stenosis and insufficiency 5 years after operation. All 13-surviving patients are asymptomatic at latest follow up. Conclusion: Konno aortoventriculoplasty with repeat AVR may be safely performed. Excellent results may be achieved despite previous aortic root enlargement. It is a good surgical option for complex LVOTO and may even reduce reoperation in children by allowing placement of a larger prosthesis.     

Reoperation for prosthetic valve degeneration after Konno aortoventriculoplasty

Since the introduction of the aortoventriculoplasty procedure by Konno in 1975, 16 patients have undergone aortic root augmentation by this method at the Woodruff Medical Center of Emory University. In four patients bioprosthetic valve degeneration 2 to 5 years after the Konno procedure has necessitated repeat operation and replacement of the prosthetic aortic valve. Modification of the septal patch or repeat right ventriculotomy has not been required. One patient required an additional lateral anulus-enlargement procedure (Manouguian) whereas the other three have demonstrated stability or growth of the aortic anulus. We have not observed recurrent subvalvular stenosis or problems with the right ventricular outflow tract. Repeat operation after aortoventriculoplasty has been relatively simple and has usually involved only the supra-annular aorta.     

Aortoventriculoplasty for different types of left ventricular outflow tract obstructions

Since the first clinical application of aortoventriculoplasty for tunnel subaortic stenosis in 1974 the indication for this method was extended to other types of left ventricular outflow tract stenoses (LVOTO). The operative technique consists of enlarging both the left and right ventricular outflow tracts and inserting an aortic prosthetic valve. 47 operations have been performed in patients with various types of LVOTO: 8 narrow annulus, 23 diffuse subaortic stenosis (multiple level stenosis), 9 complex forms of tunnel subaortic stenosis (Shone complex) 3 outgrown prosthesis, 4 obstructive idiopathic hypertrophic subaortic stenosis. Patients ages ranged from 4 to 35 years. Overall mortality was 13%, there were no late deaths, in the last 34 patients there was no death. In 25 patients there had been 1, and in 13 patients 2 previous procedures. As a result of the operation 9 patients developed complete right bundle branch block or left anterior hemi-block; 2 patients developed total a-v block with the need of a permanent pacemaker 25 patients had catheterization postoperatively. The mean gradient across the left ventricular outflow tract was significantly reduced from 91.5 +/- 21 mm Hg to 13.1 +/- 15 mm Hg. According to our experience aortoventriculoplasty can be used routinely in all forms of diffuse subaortic stenosis, narrow aortic annulus, reoperation in HOCM, multiple level stenosis and outgrown aortic prosthesis.     

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; Bj?rk-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.     

The Ross/Konno Procedure

The technique of aortic valve replacement with the pulmonary autograft was originally described by Ross in 1967. Aortoventriculoplasty was first described by Konno in 1975 and was used for aortic valve replacement using a mechanical prosthesis. Since then, various refinements in both procedures as well as wider availability of cryopreserved allografts have permitted increasing application of the combined surgical approach in infants and small children. The Ross-Konno combination became particularly appealing in the treatment of complex left ventricular tract obstruction that is often not amenable to simpler techniques such as open valvulotomy or balloon valvuloplasty. The Ross-Konno technique offers a number of advantages over the two alternatives of mechanical or allograft valve replacement. It has a low risk of thromboembolism and prosthetic valve endocarditis, and avoids the lifetime anticoagulation requirement and the size limitation seen with the mechanical valves. It also seems to be free of the rapid degeneration observed with the allografts, particularly when placed in the aortic position. However, the primary advantage of the pulmonary autograft over the other two choices is its apparent potential for growth in the aortic position. Confirmed in a number of short to intermediate term follow-up studies, the Ross-Konno technique is at this time the superior option for definitive treatment of a complex LVOTO at an early age.     

A new aortoventriculoplasty for prosthetic aortic valve replacement

BACKGROUND: Konno aortoventriculoplasty demands a complex double patch reconstruction of left and right ventricular outflow tracts and is subjected to a risk of permanent heart block. A modified technique was used to overcome these difficulties.Patient and methods A 42-year-old woman with congenital aortic stenosis, a diminutive aortic annulus, and severe subaortic muscular obstruction had undergone aortic valve commissurotomy 24 years ago. At reoperation, a 19-mm St Jude Medical sizer had a very tight fit after removal of the calcified aortic valve. To enlarge the aortic annulus and septum, the pulmonary artery valve was first partly separated from the right ventricle, exposing the interventricular septum. The aortic wall, annulus, and septum were then split along the intercoronary commissure, a location that clears the aortoventriculoplasty from the path of the major conducting tissue. Once the septum was reconstructed with a Dacron patch, the enlarged orifice accepted a St Jude Medical Flex 23. The mobilized pulmonary artery valve was then sutured back to its original position, only changed by the width of the septal Dacron patch. RESULT: Discharge echocardiogram recorded a 7 mm Hg mean transprosthetic gradient with a normally functioning pulmonary valve. The electrocardiogram showed permanent sinus rhythm. CONCLUSIONS: The described aortoventriculoplasty has several advantages, including: a simple exposure obtained by partly separating the pulmonary artery valve from the right ventricle; clear septal opening landmarks that avoid the conducting tissue; easy reconstruction with a single septal patch; and an anatomically restored right ventricular outflow tract.     

Aortoventriculoplasty ad modum Konno. Experience with five cases

We have performed Konno's aortoventriculoplasty in 5 children with congenital valvular aortic stenosis and extreme annular narrowing. There was one hospital death, unrelated to the surgical procedure per se. Bleeding from the stitch holes along the patches immediately after bypass was the sole problem associated with the Konno operation in our 4 surviving patients. Preclotting of the dacron patch or use of calf pericardium did not significantly influence this type of bleeding complication. Konno's aortoventriculoplasty permitted considerable enlargement of the original annular circumference and insertion of a size of prosthesis appropriate for adult life (at least 21 mm tissue diameter) in the 4 survivors. The results were still good 1 to 5 (mean 3) years after surgery. The Konno operation is a safe procedure, which widens the hypoplastic aortic annulus to a possible maximum, relieves most forms of ventricular outflow tract obstruction and maintains the prosthetic valve in anatomic sub-coronary position, so that a left ventricular apical-aortic conduit is not required.     

Aortic root replacement following combined Konno and intracardiac repair of tetralogy of Fallot with aortic stenosis

We present a rare association of tetralogy of Fallot (TOF) with congenital aortic valvar stenosis who needed an aortoventriculoplasty for aortic root enlargement along with repair of TOF. The patient subsequently developed prosthetic valve endocarditis for which he underwent successful aortic root replacement with a porcine aortic root. Aortic root replacement for endocarditis following a Konno operation is previously undescribed.     

Transaortic mitral valve replacement

A 34-year follow-up is described after a Konno aortoventriculoplasty to correct a restricted aortic annulus and a recurrent aortic prosthetic valve endocarditis with subannular and interventricular abscesses.     

Surgical treatment of subaortic obstruction in adolescent and adults: long-term follow-up

Subaortic stenosis (SAS) is a wide spectrum of anatomical derangements ranging from a discrete fibrous membrane to tortuous fibrous tunnel with or without aortic annulus hypoplasia. We have reviewed 88 patients undergoing surgery for SAS over a 15-year period. There were 47 male and 41 female patients with a mean age of 19.8 +/- 10.6 years (range 11 to 39). Fifty-eight patients had discrete subaortic membrane, and 30 patients had diffuse tunnel subvalvular stenosis. The mean systolic pressure gradients were found to be 86.5 +/- 31.4 mmHg (range 48 to 145 mmHg). Ten patients had mild and 13 patients had moderate-to-severe aortic insufficiency (AI) preoperatively. Nine patients had bicuspid aortic valve. Forty patients (45.4%) had associated cardiac lesions. Isolated membranectomy was performed in six patients. Membranectomy associated with septal myectomy was done in 52 patients. Fifteen patients of them associated hypoplasia of the aortic orifice necessitated aortic valve replacement (AVR) using the Konno-Rastan procedure. Fifteen patients with tunnel SAS and normal aortic valves underwent a combined approach for valve sparing, a modified Konno procedure with patch septoplasty. Also eight patients required AVR because of the severity of AI and five patients aortic reconstruction procedures. Aortic commissurotomy was performed to relief of stenosis in four patients. There were three early deaths (3.4%) and one late death (1.1%) all after the Konno-Rastan procedure. Eight patients (9.1%) had permanent conduction abnormalities. Postoperative left ventricle-aorta gradient was significantly decreased at early postoperative period (p < 0.001) and ranged from 10 to 25 mmHg (mean 14.1 +/- 4.3). Fourteen patients (16.5%) were reoperated for recurrent obstruction or progression of AI. The mean reoperation interval was 4.4 +/- 1.7 years (range 2 to 8 years). Five-year reoperation-free survival was 88.0 +/- 3.6% and 12.5-year reoperation-free survival was 75.5 +/- 7.0%. Our results of aggressive surgical approach of subvalvular aortic stenosis produces relief of obstruction and frees the valve leaflets, significantly reducing associated AI with long-term survival and long-term adequate relief of left ventricular outflow tract obstruction.     

Aortoventriculoplasty in the management of an infected Cabrol graft.

This report describes use of a modified aortoventriculoplasty (Konno procedure) for reoperation on a patient with prosthetic aortic valve conduit endocarditis. The modified Konno procedure was necessary to expose the mid-left ventricular outflow tract to reconstruct an aortic annulus.     

Surgical management of complex and tunnel-like subaortic stenosis

Background: Relief of primary or secondary subaortic stenosis (SAS) remains a surgical challenge. Heart block, aortic valve regurgitation and recurrent obstruction have been persistent problems. Methods: Forty six patients who underwent surgery for complex and tunnel-like SAS between January 1990 and November 1998 were reviewed. In 45 of the 46 patients SAS developed following repair of a primary congenital heart defect and only one patient presented with de novo tunnel-like SAS. Fifteen of the 45 patients had undergone repair of double-outlet right ventricle (DORV) and the remaining 30 had undergone repair of a variety of defects. The median age at the time of surgery was 5 years. The modified Konno procedure was performed in 15 patients, Konno procedure in three, Ross–Konno procedure in two and resection of the conal septum in 12 patients. Five patients with DORV underwent replacement of the intraventricular baffle and two patients underwent an aortic valve-preserving procedure in conjunction with mitral valve replacement. Results: There were no deaths. None of the patients had an exacerbation of aortic regurgitation and none developed complete heart block. The median follow-up was 3 years (range 1 month–8.5 years). Two patients developed recurrent SAS defined as a gradient of 40 mmHg or greater diagnosed by transthoracic echocardiography. Freedom from SAS at 1, 3 and 5 years was 100, 94 and 86%, respectively. Conclusions: We favor the modified Konno procedure and conal resection to the Konno or the Ross procedure, since insertion of a prosthetic valve or homograft is avoided and aortic valve function is preserved. Excellent relief of tunnel-like SAS can be achieved without damage to the conduction tissue.     

Repair of complex left ventricular outflow tract obstruction in children

BACKGROUND: Complex obstruction of the left ventricular outflow tract (LVOTO) in children may be treated with surgical procedures like the Ross-Konno or Koncz-Konno procedures, or modifications thereof. We present our results from the last 10 years. MATERIAL AND METHOD: During the period from December 1991 to April 2002, 17 patients/children with complex LVOTO were operated on. Patients treated with balloon valvuloplasty, open commisurotomy or simple valve replacement are excluded. The procedures performed were: Koncz-Konno (KK) or modified KK (n = 10), Ross-Konno (RK) (n = 2) and Ross (RO) (n = 5). Concomitant procedures included mitral valve replacement (n = 1), aortic arc plasty (n = 1), subvalvular myotomi (n = 1), resection of subvalvular membrane (n = 1) and aorto-coronary bypass (n = 1). Patients' ages ranged from 1 to 178 months, median 71 months. Body weights ranged from 3.8 to 50.0 kg, median 19.4 kg. Eight cases were redo procedures. RESULTS: Three early deaths occurred. One patient in the KK group, one in the modified KK group and one in the RK group. One patient died 8 years postoperatively of unknown reasons; no autopsy was performed. The rest of our patients who survived the initial major surgical treatment show normal physical performance and their quality of life seems to be good. CONCLUSION: Patients with complex LVOTO can be operated with biventricular repair in selected cases. Early and late mortality are acceptable.     

Successful surgical treatment by Konno aortoventriculoplasty in 2 cases of congenital aortic valvular stenosis]

Konno's aortoventriculoplasty was performed in two children aged 6 years and 10 years old with congenital aortic valvular stenosis. One had previous aortic valvotomy at 21 days of age. Preoperative peak systolic pressure gradients between the left ventricle and the aorta were 120 and 140 mmHg, respectively. The original diameter of the aortic valve ring were 12 mm and 16 mm and one had supra-annular aortic stenosis whose diameter was 7 mm. The 19 mm and 23 mm SJM prosthetic valves were inserted in the subcoronary position. The postoperative course was uneventful. Their ECG showed sinus rhythm with complete right bundle branch block. Both two patients made good recovery regarding clinical data and symptoms.     

Reappraisal of localized resection for subvalvar aortic stenosis

Between June 1972 and August 1989, we operated on 45 patients with fixed subaortic stenosis. Discrete membranous stenosis was present in 28 patients and tunnel stenosis, in 13. Four patients had subvalvar stenosis complicating double-outlet right ventricle. There were 33 male and 12 female patients. Mean age at operation was 7.1 +/- 4.3 years (range, 6 months to 21 years). Local resection of the fibrous membrane was performed in 26 patients. Local resection was combined with myectomy in 18 patients. Aortoventriculoplasty (modified Konno procedure) was required at operation in 3 patients. There were three perioperative deaths at initial operation and two deaths at the time of reoperation. Follow-up ranges from 1 month to 17 years (average follow-up, 47.0 months). Reoperation for recurrent obstruction has been required in 12 patients (27%), and 3 patients have required a second reoperation. Mild to moderate aortic regurgitation was present in 17 patients. Subaortic stenosis is a spectrum of anatomical derangements ranging from a discrete fibrous membrane to a long, tortuous fibrous tunnel with aortic annulus hypoplasia. Successful removal of a discrete fibrous membrane can be followed later by recurrent stenosis necessitating myectomy or aortoventriculoplasty. Correction of subvalvar aortic stenosis can be followed by recurrent stenosis necessitating reoperation as long as 17 years after the initial procedure.     

Aortic valve replacement for aortic stenosis with a small mechanical prosthetic valve

BACKGROUND: Although aortic valve replacement (AVR) is the only effective treatment for patients with aortic stenosis (AS), it is recognized that the use of small prosthetic valves due to a small aortic root often affects postoperative course after AVR. The aim of this study was to determine whether the use of small prosthetic valves was a risk factor of AVR for AS. METHODS: We compared various perioperative factors and operative outcomes between patients with a small mechanical prosthetic valve (small group) and patients with a large mechanical prosthetic valve (large group). RESULTS: Early mortality was 0% in each group and the 5-year mortality was 25% in the small group and 10% in the large group. There were no significant differences in perioperative factors between the two groups. The small group patients were significantly older and smaller compared to the large group patients. The valve size was significantly correlated with age and BSA. CONCLUSIONS: The use of small mechanical prostheses was not a risk factor of AVR for AS when it was proportionate to the BSA even for elderly patients. AVR using a small mechanical prosthetic valve may be performed with good results in the short- and long-term.     

Successful biventricular repair after initial Norwood operation for interrupted aortic arch with severe left ventricular outflow tract obstruction

Background. Management of newborns with interrupted aortic arch (IAA) remains challenging. Associated severe left ventricular outflow tract obstruction (LVOTO) have often led to increased mortality with neonatal biventricular repair. We review our experience with an alternative approach for this complex surgical problem.

Methods. From May 1991 to June 1999, 28 neonates were treated for IAA. Thirteen of 28 neonates (46%) had type B IAA, ventricular septal defect (VSD) and severe LVOTO (Z value –2 to –7; mean –5 ± 1.7). Mean age was 8 days (3 to 23 days old) with average weight of 3.3 kg (2.4 to 4.2 kg). Eight of 13 (62%) had anomalous right subclavian artery. Ten of 13 (77%) had thymic aplasia and chromosome 22 region q11 deletion. All 13 patients were treated initially with a modified Norwood procedure.

Results. There were no perioperative deaths. Complications included 2 patients with recurrent arch stenosis treated with balloon dilatation. Two patients had systemic arterial shunt revision. Follow-up ranged from 2 to 99 months old (mean 39 months). There were 2 late deaths unrelated to any operation. Nine of 12 patients had a second stage palliation consisting of a bidirectional Glenn shunt. Six patients went on to have biventricular repairs (3 Ross-Konno, 2 Rastelli, 1 VSD closure with LVOT resection). One patient had a modified Fontan operation and 5 patients are awaiting potential biventricular repair.

Conclusions. Children with IAA and severe LVOTO may be managed by initial Norwood palliation with an excellent outcome likely. This initial “univentricular” approach has enabled eventual successful biventricular repair despite severe LVOTO.     

Surgical treatment of subaortic stenosis: a seventeen-year experience

OBJECTIVE: The aim of the study was to analyze the long-term results of subaortic stenosis relief and the risk factors associated with recurrence and reoperation. METHODS: One hundred sixty patients with subaortic stenosis underwent biventricular repair. Before the operation the mean left ventricle-aorta gradient was 80 +/- 35 mm Hg, 57 patients had aortic regurgitation, and 34 were in New York Heart Association functional class III or IV. Median age at repair was 10 years. For discrete subaortic stenosis (n = 120), 39 patients underwent isolated membranectomy, 67 underwent membranectomy with associated septal myotomy, and 14 underwent septal myectomy. Tunnel subaortic stenosis (n = 34) was treated by myotomy in 10 cases, myectomy in 12, septoplasty in 7, Konno procedure in 3, and apical conduit in 2. Aortic valve replacement was performed in 6 cases, mitral valve replacement in 2 cases, and mitral valvuloplasty in 4 cases. RESULTS: There were 5 early (3.1%) and 4 late (4.4%) deaths. Within 3.6 +/- 3.3 years a recurrent gradient greater than 30 mm Hg was found in 42 patients (27%), 20 of whom had 26 reoperations. According to multivariable Cox regression analysis survival was influenced by hypoplastic aortic anulus (P =.01) and mitral stenosis (P =.048); recurrence and reoperation were influenced by coarctation and immediate postoperative left ventricular outflow tract gradients. At a median follow-up of 13.3 years, mean left ventricle-aorta gradient was 20 +/- 13 mm Hg. Relief of the subaortic stenosis improved the degree of aortic regurgitation in 86% of patients with preoperative aortic regurgitation. Actuarial survival and freedom from reoperation rates at 15 years were 94% +/- 1.3% and 85% +/- 6%, respectively. CONCLUSION: Although surgical treatment provides good results, recurrence and reoperation are significantly influenced by previous coarctation repair and by the quality of initial relief of subaortic stenosis.     

The modified Konno procedure for complex left ventricular outflow tract obstruction

BACKGROUND: Complex left ventricular outflow tract (LVOT) obstruction with normal aortic valve function requires aggressive resection in the subaortic region and preservation of the aortic valve. The modified Konno procedure allows generous exposure of the LVOT from the left ventricular apex to the inter leaflet trigones of the aortic valve. Widespread use of this procedure has been limited by concern over injury to the aortic valve, the conduction system, and possibility of residual ventricular septal defect (VSD). METHODS: Retrospective analysis of pertinent data for all patients undergoing the modified Konno procedure (1994 to 2001) at the University of Iowa were reviewed. RESULTS: The modified Konno procedure was used in 18 patients (age 1 to 31) for LVOT obstruction associated with diffuse narrowing of the LVOT (n = 7), a discrete fibrous ring (n = 7), or a fibrous ring associated with abnormal mitral attachments (n = 4). Eight patients had previously undergone LVOT resection. There were no perioperative deaths. Estimated LVOT peak gradients by echocardiogram were 70.4 +/- 24.2 mm Hg (preoperative) and 19.2 +/- 20.4 mm Hg (postoperative) at most recent followup (p < 0.001 vs preop). Aortic insufficiency was moderate in one patient (present preop) and mild or less in all other patients. There were no cases of permanent heart block. Small residual VSDs were present in five patients (28%). Median follow-up is 3.1 years. CONCLUSIONS: The modified Konno procedure can effectively relieve complex LVOT obstruction and preserve aortic valve function. Extension of this procedure for use in the initial presentation of LVOT may be appropriate in cases at increased risk of recurrent LVOT obstruction.     

Surgical management of diffuse subaortic stenosis: an integrated approach

An integrated approach to the surgical management of diffuse subaortic stenosis has been designed to provide adequate relief of left ventricular outflow tract obstruction whatever the anatomical features encountered at operation. This approach was used in 22 patients with tunnel subaortic stenosis (19 patients) or diffuse hypertrophic obstructive cardiomyopathy (3 patients). The obstructive tissue was resected through an aortoseptal approach. In 18 patients, associated hypoplasia of the aortic orifice necessitated aortic valve replacement using the Konno procedure; in 4 patients with a normal-sized aortic orifice, the native aortic valve was preserved. There were two early deaths and one late death (all after a Konno operation). Long-term adequate relief of left ventricular outflow tract obstruction was achieved in all survivors. Operation for diffuse subaortic stenosis should be performed with two main goals: (1) to obtain complete relief of the left ventricular outflow tract obstruction by the appropriate procedure and (2) to preserve the native aortic valve whenever possible, particularly in young patients.