Extended aortic root replacement with cryopreserved allografts: do they hold up?

The extended aortic root replacement technique is used for the surgical repair of left ventricular outflow tract obstruction complicated by concurrent hypoplastic aortic annulus, multiple levels of obstruction, or aortic insufficiency. Extended aortic root replacement incorporates the concepts of aortic root replacement and aortoventriculoplasty to create a comparatively simple procedure. Unique features of the technique include the implantation of an allograft, which makes the need for anticoagulation obsolete, and use of the donor mitral leaflet to enlarge the outflow tract. Since 1985, 32 patients in Denver have undergone placement of a cryopreserved aortic valve allograft as part of extended aortic root replacement. There were four hospital deaths (13%), and 1 child underwent cardiac transplantation 30 hours after operation. In 6 months to 4.8 years of follow-up, a 14-year-old boy with familial hyperlipidemia required coronary artery bypass grafting, and 3 children experienced allograft calcification with progressive insufficiency, which prompted allograft replacement. The other 23 patients are clinically well.     

Allograft aortic valve replacement for bicuspid aortic valves with 180-degree coronary ostia

Congenital bicuspid aortic stenosis is often an indication for aortic valve replacement in young adults and children. However, when the coronary ostia are exactly 180 degrees opposite each other, placing a trileaflet human allograft with freehand technique can be difficult. The described technique enlarges the left ventricular outflow tract beginning at the annulus level, using only allograft tissue. In addition to allowing placement of a larger allograft, this method rotates the coronary ostia toward each other, converting the aortic root to three-sinus anatomy.     

Issues and outcomes in the management of supravalvar aortic stenosis

BACKGROUND: Supravalvar stenosis of the aorta is an uncommon congenital cardiac anomaly that involves not only the supravalvar aorta but the entire aortic root. Despite considerable attention to the importance of maintaining the integrity of the aortic root during supravalvar reconstruction, there has been little focus on the management of other components of the aortic root and left ventricular outflow tract, including the aortic valve, subvalvar region, and coronary arteries. METHODS: We reviewed the records of 36 consecutive patients with supravalvar aortic stenosis who underwent repair from 1992-1998 (median age, 4 years). Discrete stenosis was present in 29 patients, whereas the remaining 7 had the diffuse form of the disease. Associated anomalies of the aortic root and adjacent structures were present in 23 patients. The median pressure gradient across the left ventricular outflow tract was 70 mm Hg. Supravalvar stenosis was relieved by extended aortoplasty with a Y-shaped patch in 18 patients, resection of the stenotic segment of ascending aorta at the sinotubular junction with end-to-end anastomosis of the ascending aorta in 7, the Ross procedure in 4, and other techniques in 7. Additional procedures included aortic valvuloplasty in 10 patients, resection of subvalvar stenosis in 11, and procedures on the coronary arteries in 2. RESULTS: There was 1 perioperative death, and no reoperations or other significant complications. During follow-up (median 33 months), there were no deaths and 3 reoperations for replacement of the aortic valve with a pulmonary autograft (n = 1) or mechanical prosthesis (n = 2). The median pressure gradient across the left ventricular outflow tract was 10 mm Hg. CONCLUSIONS: In patients with supravalvar aortic stenosis, abnormalities of the aortic valve, subaortic region, and coronary arteries are frequently present as well. Management of these issues is as critical to the long-term outcome of these patients as reconstruction of the supravalvar aorta. Aggressive valvuloplasty may help decrease the incidence of late aortic valve replacement, whereas the Ross procedure may be a preferable approach in some patients with complex outflow tract obstruction.     

Subvalvar aortic stenosis: timing of operation

Subvalvar aortic stenosis can be associated with progressive left ventricular outflow tract obstruction, aortic insufficiency, and infective endocarditis. We reviewed the records of 36 surgical patients who underwent 39 operations for subaortic stenosis. Seventeen patients had associated congenital cardiac anomalies. One perioperative death occurred in a patient with tetralogy of Fallot. The mean preoperative left ventricular outflow tract systolic pressure gradient was 64 +/- 5 mm Hg (+/- standard error of the mean) and decreased to 9 +/- 2 mm Hg postoperatively (p less than 0.001). Reliable preoperative and postoperative information regarding aortic valve function was available for 27 patients. Aortic insufficiency was found in 17 (63%) of those patients preoperatively. Postoperatively, insufficiency increased in 3 patients and decreased in 4; none of these changes was major. Severity of preoperative aortic insufficiency increased significantly with age (p less than 0.05), but did not correlate with left ventricular outflow tract gradient. The information from this study and previous studies suggests that resection of subaortic stenosis is safe and effective, and operation at the time of diagnosis, regardless of left ventricular outflow tract gradient or symptomatic status, is a reasonable therapeutic alternative.     

Diagnosis, transport, and outcome in fetuses with left ventricular outflow tract obstruction

Between March 1986 and April 1990, 22 consecutive fetuses (at gestational ages of 21 to 38 weeks) with a suspected diagnosis of critical (ductus-dependent) left ventricular outflow tract obstruction on fetal echocardiogram were referred to our center for delivery and surgical treatment. Diagnoses were hypoplastic left heart syndrome (n = 16), valvular aortic stenosis (n = 2), common atrioventricular canal with subaortic stenosis (n = 3), and single ventricle with subaortic stenosis (n = 1). Postnatal echocardiography revealed that fetal echocardiography was correct in predicting left ventricular outflow tract obstruction to be critical in all but one patient, for a positive predictive value of 96%. Of the 21 patients with true, critical left ventricular outflow tract obstruction, 17 patients underwent cardiac surgery as neonates (birth to 6 days of age, median 2 days); 13 (or 77%) survived and were discharged from the hospital. In addition, one patient underwent successful balloon aortic valvotomy for critical valvular aortic stenosis but later died of sepsis. Lethal chromosomal and congenital abnormalities should be sought and are contraindications for this approach. In utero transport of fetuses with suspected critical left ventricular outflow tract obstruction to a neonatal cardiac surgical center can result in improved neonatal condition and may improve overall survival.     

Aortic Valve Prosthesis Obstruction After Aortoventriculoplasty: Reconstruction with Aortic Allograft

An aortoventrlculoplasty (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 falled prostheses, even in the presence of complex left ventricular outflow tract morphology or previous reconstruction operations. (J Card Surg 1994;9:348–352)     

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.     

Recurrent discrete subaortic stenosis and small aortic annulus successfully repaired by the Konno procedure in a young woman

A 24-year-old woman who had undergone excision of the membrane for discrete subaortic stenosis when 6 years old displayed recurrent subaortic stenosis and had a small aortic annulus, with a peak pressure gradient of 60 mmHg. We chose to perform the Konno operation with a mechanical valve. This released the left ventricular outflow tract obstruction adequately, and she recovered uneventfully with New York Heart Association functional class I. In our experience, an aggressive strategy such as myectomy is an appropriate initial procedure for preventing recurrence when the geometry of the problem may lead to recurrence in the left ventricular outflow tract. The Konno operation is a good option for recurrent subaortic stenosis with small aortic annulus.     

Results of aortoventriculoplasty in 21 consecutive patients with left ventricular outflow tract obstruction

Results of aortoventriculoplasty (AVP) are reported in 21 patients with various types of left ventricular outflow tract obstruction (LVOTO). The concept of AVP is based on creating a surgical aortoseptal defect which is patched to provide the largest possible outflow tract to the left ventricle. Lesions consisted of isolated diffuse fibromuscular subaortic stenosis in six patients, diffuse subaortic stenosis and associated other cardiovascular anomalies in five, hypoplastic aortic anulus in two, idiopathic hypertrophic subaortic stenosis (IHSS) in two, and stenosis of a previously implanted aortic valvular prosthesis in three patients. Ten patients had had at least one unsuccessful previous surgical attempt to relieve the LVOTO. The coexisting mitral incompetence in IHSS disappeared after AVP alone. Immediate postoperative hemodynamic results were excellent in all cases. Postoperative death in five patients was due to advance myocardial failure in two, brain damage in one, transection of a dominant septal artery in one, and severe acidosis with renal failure in the last case. However, in the last 16 patients (17 operations) the only death (5.8 percent) was that caused by uncontrollable acidosis. Follow-up results indicate that 16 patients are clinically doing well, and hemodynamic studies in 14 patients are rated as excellent or good from 1 to 25 months postoperatively. It is concluded that AVP is an effective operation for managing all types of LVOTO and can be used routinely with an acceptably low mortality rate.     

Acquired supravalvular aortic stenosis.

Severe supravalvular aortic stenosis was discovered at reoperation in 3 children with recurrent stenosis of the left ventricular outflow tract. The lesion consisted of gross thickening of the sinus ridge, most marked at the site of the previous aortotomy. The thickening had shortened the free edge of one or more leaflets and had distorted adjacent commissures. Preoperative angiography had indicated valve stenosis, but little commissural fusion was found at operation and the outflow tract obstruction was relieved by inserting a prosthetic patch in the ascending aorta. Recognition of this iatrogenic pathology is important to avoid supravalvular stenosis after aortic valvotomy and unnecessary valve replacement in children requiring reoperation for recurrent left ventricular outflow tract obstruction.     

Aortoventriculoplasty after a prior posterior root enlargement (Manougian): case report

A patient with congenital bicuspid aortic stenosis had an open commissurotomy followed 3 years later by a Manougian's operation along with an aortic valve replacement. Nine years later, due to residual aortic stenosis, a Konno's anterior root enlarging procedure with an aortic valve replacement was successfully done. Good relief of aortic and subaortic stenosis and the absence of significant gradient across the left ventricular outflow tract led us to believe that successful and effective relief could be obtained by adding a Konno-type of enlargement to a previously performed posterior enlargement procedure.     

Left ventricular outflow enlargement by the Konno procedure

The optimal management of patients with small aortic anulus or left ventricular outflow tract obstruction remains unclear. Between 1976 and March, 1982; 18 patients have undergone enlargement of their left ventricular outflow tract by means of the Konno or a modification of the Konno procedure. Fourteen of these 18 patients had previous operations for aortic stenosis or tunnel left ventricular outflow tract, and two patients had undergone three previous operations. All 18 patients had symptoms of either heart failure of chest pain, or had electrocardiographic evidence of strain. They ranged in age from 4 years to 58 years, with 13 of the 18 patients being less than 20 years of age. A Dacron patch was used to enlarge the left ventricular outflow tract after incising down the ventricular septum. In all patients, at least a 21 mm valve could be placed, with between 50% and 65% of the valve anulus being made up of natural tissue. The remaining portion of the valve anulus was constructed from the Dacron patch. The patch was extended up to enlarge the ascending aorta, and a pericardial patch was used to close the defect in the right ventricular outflow tract. In all 18 patients the gradient was obliterated at the time of operation. There was one early death in a patient who had previous insertion of a left ventricular apical-aortic conduit in which the heterograft valve had degenerated. There has been one late death because of bacterial endocarditis in a child who also had a parachute mitral valve and evidence of pulmonary hypertension. The remaining 16 patients are functioning well after the Konno procedure. Three are receiving warfarin sodium, and 13 are receiving aspirin. These results suggest that this is an acceptable method of treating patients with small aortic anulus or left ventricular outflow tract obstructions and would appear to have advantages over a left ventricular apical-aortic conduit.     

Aortoventriculoplasty in a patient with complex left ventricular outflow tract obstruction,mitral valve stenosis and aneurysm of the ascending aorta

We describe a new method of aortoventriculoplasty in a patient with calcified mitral stenosis, aortic valvular stenosis, severe left ventricular outflow tract obstruction, and aneurysm of the ascending aorta. This complex pathology was successfully treated with replacement of both the valves and a tubular dacron graft. The proximal end of the dacron tube was tailored as a patch for the repair of the ventricular septum and the aortic root, and the distal end was anastomosed to the distal ascending aorta. The patient had an uneventful recovery and postoperative echocardiography showed no significant residual gradient on the left ventricular outflow tract.     

Apico-aortic conduits in children with severe left ventricular outflow tract obstruction

BACKGROUND: Infrequently, congenital heart defects are complicated by left ventricular outflow tract obstruction (LVOTO) not amenable to conventional reconstruction. Apico-aortic conduits provide a means of palliating such patients until definitive repair is possible. The purpose of this study was to review a single institution's current experience with apico-aortic conduits. METHODS: The medical records of pediatric patients receiving apico-aortic conduits were reviewed. Demographics, operative techniques, preoperative and postoperative physiologic variables, morbidity, mortality, and functional class were recorded. Off-pump and on-pump procedures were categorized for comparison. RESULTS: Ten cases of apico-aortic conduits for left ventricular outflow tract obstruction were identified. Indications included congenital aortic stenosis, aortic atresia, and subaortic stenosis. Six procedures were performed off-pump and four required median sternotomy with cardiopulmonary bypass as necessitated by concomitant procedures. There was one operative death. The remaining patients demonstrated hemodynamic improvements and are all alive to date. One patient required conduit valve replacement. All patients are in New York Heart Association classification I or II at the time of last follow-up. CONCLUSIONS: Apico-aortic conduits provide a safe and effective treatment alternative for select cases of left ventricular outflow tract obstruction. Off-pump techniques are feasible in the majority of cases. This valuable adjunct should be considered whenever conventional repair of left ventricular outflow tract obstruction is considered prohibitive.     

Ross procedure for complex left ventricular outflow tract obstruction

BACKGROUND: Complex left ventricular outflow tract (LVOT) obstruction in children continues to pose a significant therapeutic challenge to cardiac surgeons. The Ross procedure, in combination with resection of subaortic stenosis or a Konno type septal incision, is an important option for these difficult patients. METHODS: Recently two children aged 14 and 5 years with LVOT obstruction involving combined subaortic and valvar stenosis underwent surgical correction using the pulmonary autograft. Clinical presentation, operative technique, outcome and intermediate follow-up are detailed. RESULTS: One patient had resection of an isolated subaortic membrane in combination with a pulmonary autograft and the second a Ross Konno procedure. Postoperative hospital stays were without complication. Both patients were discharged at 5 days and have no significant obstruction nor semilunar valve insufficiency at 3 years' follow-up. CONCLUSIONS: Pulmonary autografts can be used in combination with resection of subaortic tissue or a septal incision for reconstruction of complex left ventricular outflow tract obstruction. This technique renders excellent short term valve function, relief of obstruction, avoids anticoagulation and provides potential for future growth.     

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.     

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.     

Septoplasty for left ventricular outflow obstruction without aortic valve replacement: a new technique

A new technique is described for relief of diffuse obstruction in the left ventricular outflow tract without aortic valve replacement. Left ventricular septoplasty was performed, preserving the aortic valve. The supra-valve stenosis was repaired using a Y-shaped extension of the aortotomy proximally and a pantaloon-shaped patch of woven Dacron fabric. A 10-year-old girl with "tunnel" or diffuse stenosis obtained striking relief of left ventricular hypertension by this technique.     

Conal enlargement for diffuse subaortic stenosis

Twelve patients underwent conal enlargement for diffuse subaortic stenosis over a 3 1/2-year period. The subaortic stenosis was due to tunnel outflow in 11 and malattached mitral valve in one. Mean age was 4.4 +/- 4 years and mean subaortic gradient was 50 +/- 21 mm Hg. Three infants had a malalignment ventricular septal defect. In eight patients significant obstruction occurred 2 to 7 years (mean 4 +/- 2) after simple resection of subaortic stenosis (n = 2), ventricular septal defect closure (n = 2), ventricular septal defect closure and subaortic stenosis resection (n = 2), and canal repair (n = 2). In three infants the tunnel outflow distal to a malalignment ventricular septal defect was enlarged and closed with the defect. In three patients with subaortic stenosis proximal to a previously repaired ventricular septal defect, transatrial conal enlargement through the ventricular septal defect was performed. Another patient without a ventricular septal defect had transatrial conal enlargement. The remaining five patients had the modified Konno procedure. Two patients had postoperative complete heart block and one infant had insertion of an apicoaortic conduit for aortic anulus hypoplasia 9 months later. One patient died of pneumonia during the follow-up period. Postoperative echographic outflow gradients up to 3 1/2 years (mean 1.2 +/- 1) ranged up to 25 mm Hg (mean 7 +/- 11) and were mainly at the aortic level. The 11 surviving patients are doing well up to 3 1/2 years of follow-up (mean 1.5 +/- 1). We conclude that conal enlargement procedures with aortic valve preservation are preferable, effective, and can be safely performed for diffuse subaortic stenosis in infants and children.     

Extended aortic root replacement with aortic allografts or pulmonary autografts in children.

OBJECTIVES: To evaluate the early results and effectiveness of left ventricular outflow tract enlargement with aortic allograft or pulmonary autograft in children with complex left ventricular outflow tract obstruction. METHOD: The records of 30 children who underwent aortic root enlargement and replacement with either an aortic allograft (22 patients) or pulmonary autograft (8 patients) between January 1987 and June 1997 were reviewed. The predominant diagnosis was complex left ventricular outflow tract obstruction (n = 19), associated with aortic incompetence in 11 children. Before root enlargement, 27 children underwent surgical valvotomy (14 patients), balloon dilatation (10 patients), or both interventions (3 patients). Mean age at root enlargement was 5.4 +/- 3.5 years (range, 2 days-16 years). Most of the children (27 patients) underwent a Konno aortoventriculoplasty. Concomitant septal myectomy was performed in 4 children, mitral valve procedure in 5 children, and endocardial fibroelastosis resection in 1 child. RESULTS: Five children (17%) died in hospital. Four of these were infants less than 2 months old. All had acute aortic incompetence as the result of recent intervention necessitating urgent operation. The fifth child, aged 10 years, died of myocardial failure 2 weeks after the operation. During the follow-up period (mean length, 4.1 +/- 2.8 years), sudden death occurred in 1 child 3 months after the operation. Follow-up echocardiograms (obtained for 23 of the surviving 24 children within 3 +/- 2.3 years) showed a left ventricular outflow tract gradient reduced from a mean of 65 to 11 mm Hg (P =.001); Z value increased from a mean of -0.5 to 4.1 (P <. 001), and aortic incompetence was trivial or mild except in 2 children. CONCLUSION: Urgent aortic root enlargement in decompensating neonates carries higher mortality rates. In older children, the early results of root enlargement and implantation of allograft or autograft are good.