Asian Cardiovasc Thorac Ann 2006;14:377-381
© 2006 Asia Publishing EXchange Ltd
Classic Konno-Rastan Procedure: Indications and Results in the Current Era
Mohammad B Tabatabaie, MD,
Alireza A Ghavidel, MD,
Mohammad A Yousefnia, MD,
Saeed Hoseini, MD,
Seyed H Javadpour, FETCS,
Kamal Raesi, MD
Shahid Rajaee Heart Centre, Iran University of Medical Sciences, Tehran, Iran
For reprint information contact: Alireza A Ghavidel, MD Tel: 98 21 2264 2894 Fax: 98 21 2204 2037 Email: aaghavidel{at}yahoo.com, Shahid Rajaee Heart Centre, Vali-e-Asr Avenue, Tehran, Iran.
 |
ABSTRACT
|
|---|
Diffuse or unresectable subaortic stenosis is difficult to treat and needs aggressive resection to effectively relieve the obstruction. Anterior aortoventriculoplasty, known as the Konno-Rastan procedure, has been shown to effectively tackle the problems encountered in diffuse subaortic stenosis. A retrospective study was carried out on patients who had undergone a Konno-Rastan procedure at our institution from March 1997 to November 2003. There were 26 patients (16 males and 10 females). The mean age at operation was 12.8 ± 7 years. The mean follow-up period was 30.4 ± 14.5 months. Only mechanical valves were used in this group of patients. The overall 30-day mortality was 11.5% (3 patients). The mean preoperative peak systolic gradient decreased significantly from 91.3 ± 39.3 to 28.1 ± 17.7 mm Hg. Four patients developed permanent complete heart block and 2 had a residual ventricular septal defect in late follow-up. The classic Konno-Rastan procedure using a mechanical valve can be performed with acceptable morbidity and mortality in this difficult group of patients.
|
INTRODUCTION
|
|---|
Complex left ventricular outflow tract (LVOT) obstruction continues to pose a serious challenge to the surgeon. Diffuse or unresectable subaortic stenosis (SAS) requires aggressive treatment to achieve satisfactory relief of obstruction. However, the situation becomes even more problematic in multilevel LVOT obstruction that necessitates replacement of the aortic valve as well as aortic root enlargement. Anterior aortoventriculoplasty, described by Rastan and Koncz1 and by Konno and colleagues2 in 1975, is the most effective technique for enlargement of the aortic root. The disadvantage of the classic Konno-Rastan procedure is insertion of a mechanical or biologic aortic valve, with the need for long-term anticoagulation and the risks of endocarditis or degeneration. In addition, valve outgrowth in children raises the need for re-operations. To avoid some of these limitations, other procedures have been devised to preserve the aortic valve; however, they cannot be applied in situations where the aortic valve is abnormal and needs replacement.3,4 The Ross-Konno procedure is a promising technique and early results have been encouraging, but homograft availability may limit this procedure in certain parts of the world. For historical and other reasons, we have used the classic Konno-Rastan procedure for treatment of complex LVOT obstruction, and herein report our experience with this technique.
|
PATIENTS AND METHODS
|
|---|
All patients undergoing a Konno-Rastan procedure at the Rajaee Heart Center (Iran University of Medical Sciences) from March 1997 to November 2003 were identified through our surgical database. Medical records, echocardiography, catheterization reports, and findings at follow-up were reviewed retrospectively. There were 26 patients: 16 males and 10 females, who were followed up for a mean period of 30.4 ± 14.5 months (range, 6 to 84 months). The mean age at operation was 12.8 ± 7 years (range, 5 to 31 years). Nine patients were operated on for a small aortic root and the other 17 had various forms of diffuse LVOT obstruction. Associated conditions are listed in Table 1
. Twenty-one patients had previous interventions (Table 2).
All procedures were performed through a median sternotomy. Cardiopulmonary bypass was established using aortic cannulation in the majority of patients, and bicaval cannulation in all. Moderate hypothermia and multidose antegrade blood cardioplegia were used. The aortic valve and LVOT were evaluated through a vertical aortotomy (Figure 1), with a transverse incision in selected cases. When the aortic valve was deemed irreparable, it was excised and the aortotomy was extended through the aortic annulus between the right and noncoronary sinuses from the left side of the right coronary artery, as described by Rastan.5 The incision was continued through (and slightly to the left of) the right ventricular outflow tract, exposing the interventricular septum (Figure 1). The incision was carried over the thickened septum in the region of the crista supraventricularis, avoiding the conduction tissue and exposing the left ventricular cavity. Resection of fibrous tissue, web, or hypertrophied muscle was carried out if necessary to enlarge the LVOT. This was performed through the left side of the septal incision to avoid injury to the conduction system. The defect was reconstructed using half of an elliptical shaped autologous pericardial or Dacron patch that was secured with interrupted or running 4/0 polypropylene sutures, according to the preference of the surgeon (Figure 2). The mid-portion of this patch was used to complete and enlarge the aortic annulus. After excising the abnormal aortic valve, a suitably sized mechanical valve was inserted into the newly formed aortic annulus. The remainder of the same patch was used to repair the aortotomy. Finally, closure of the right ventricular outflow tract was performed using a second pericardial, Dacron, or Gore-Tex patch.
View larger version (58K):
[in this window]
[in a new window]
|
Figure 1. Incision through the ascending aorta, aortic annulus, and right ventricular outflow tract (RVOT), exposing the interventricular septum.
|
|
View larger version (47K):
[in this window]
[in a new window]
|
Figure 2. Insertion of a prosthetic aortic valve with patch enlargement of the left ventricular outflow tract and the aortic annulus, and a second patch to close the right ventricular outflow tract. IVS = interventricular septum.
|
|
|
RESULTS
|
|---|
In the immediate postoperative period, the mean peak systolic gradient decreased from the preoperative value of 91.3 ± 39.3 to 28.1 ± 17.7 mm Hg (t test, p < 0.001). Figure 3 illustrates the changes in gradient following surgery in each patient. Hospital (30-day) mortality was 11.5% (3 patients). A 5-year-old child died in the operating room because of pump failure and inability to wean off cardiopulmonary bypass. The second death was in a 9-year-old child who suffered a perioperative cerebrovascular accident and died of intractable tachyarrhythmia on the 9th postoperative day. The 3rd death was due to bleeding diatheses. There has been no late death among the 23 survivors.
View larger version (20K):
[in this window]
[in a new window]
|
Figure 3. Pre- and postoperative peak systolic left ventricular outflow tract gradient in patients who underwent the Konno-Rastan procedure.
|
|
Five patients had transient heart block, and 4 developed complete heart block requiring permanent epicardial pacemaker placement. Two patients were found to have a mild paravalvular leak and residual ventricular septal defect on transthoracic echocardiography immediately after the procedure; these resolved during follow-up. One patient developed a small residual ventricular septal defect (pressure gradient, 66 mm Hg) in the 5th month after the operation, although he had a fever 2 weeks after his surgery, we could not find any evidence of endocarditis. In all, 8.6% of our patients were found to have a residual ventricular septal defect. Two other patients had significant gradients (> 60 mmHg) across the LVOT in the immediate postoperative period, which decreased to < 30 mm Hg later in the follow-up period.
|
DISCUSSION
|
|---|
Discrete SAS is present in 8% to 30% of patients with LVOT obstruction.6 Chevers7 first reported this abnormality in 1842. Spencer and colleagues8,9 later described the diffuse tunnel form of SAS, and in 1958, repaired this defect using cardiopulmonary bypass. After the groups of Rastan1 and Konno2 devised the technique of anterior aortoventriculoplasty in 1975, effective treatment of diffuse SAS became possible. In the past 30 years, surgeons have developed other procedures to tackle the problems encountered in the classic Konno-Rastan operation. Kirklin and Barret-Boyes3 used a modified version to preserve the integrity of the aortic valve and annulus, thereby avoiding the disadvantages of mechanical or biologic aortic valves. Cooley and Garrett 4 reported the technique of septoplasty with similar aims. Vouhé and colleagues10 further advanced the concept of diffuse SAS repair with incision of the aortic annulus through the left fibrous trigone, resection of the obstruction, and reconstruction of the annulus and the conal septum, thereby preserving the native aortic valve.
Diffuse SAS may be present primarily or following resection of a discrete obstruction.11,12 In the latter situation, it is controversial whether this is a residual or recurrent phenomenon. Some series had a high incidence of recurrence after initial resection of discrete SAS, and this recurrence is often in the form of tunnel or diffuse SAS.13 These experiences point to the fact that differentiating a localized stenotic segment from a diffuse one is not always easy, and they emphasize the need for adequate resection of these lesions to achieve satisfactory results. Furthermore, the question of multilevel stenosis, including the state of the aortic valve and annulus, should be addressed before an appropriate surgical strategy can be determined. Children with multilevel LVOT obstruction may need an initial palliative procedure, such as open aortic valvotomy, balloon aortic valvuloplasty, or resection of a subaortic membrane or muscle. These procedures get the patient through the initial critical period and may have good long-term results. In addition, they provide a means of avoiding complex and lengthy operations during the first few years of life. Indeed, the majority of our patients (81%) underwent a palliative procedure as their initial treatment.
One of the main disadvantages of the classic Konno-Rastan operation is the morbidity associated with mechanical and biologic valves. We did not use any biological valves in our patients. Although avoiding anticoagulation is an advantage with these valves, they degenerate rapidly in children, and it has been shown that freedom from re-operation at 10 years is zero in these patients.14 Thromboembolism and anticoagulation-related hemorrhage appear to be less problematic in children with mechanical prosthetic valves; none of our patients developed either of these complications, and other series with long-term follow-up had similar findings.14–18 Prosthetic valve endocarditis and valve outgrowth are the two main reasons for re-operation in this group of patients, freedom from re-operation being 80% at 10 years and declining to 52% by 15 years.14 We have had no re-operation in our patients but we acknowledge that this is due to our short follow-up period. The one patient in our study who developed fever did not have any evidence of endocarditis, and his fever resolved with no untoward effects.
The incidence of complete heart block in our series was 15.3%, others have reported an incidence ranging from 9% to 12.5%.14–16 Cobanoglu and colleagues16 had no cases of complete heart block after anterior aortoventriculoplasty for aortic valve replacement in patients with a small aortic root; this might be due to the less extensive resection of the LVOT in this group of patients. Others using the Ross-Konno technique also report a reduced incidence of complete heart block of around 6%.14,18,19 Vouhé and colleagues10 had no cases of complete heart block; they used the aortoseptal approach with division of the aortic annulus through the left fibrous trigone, which allows the surgeon to keep further away from the conduction tissue.
Over the past 20 years, mortality from the Konno-Rastan operation using mechanical valves has declined from 25% to approximately 10%.14 For older children, the mortality ranges from 4.7% to 8.3%.15,16 The Ross-Konno procedure carries a lower mortality rate, whether this is because of more recent experience with this technique or due to the fact that homograft implantation results in lower postoperative LVOT gradients needs to be determined.14,19,20 The mortality in our series was 11.5% and we identified 2 factors that may have contributed to this: firstly, the mean gradient across the LVOT obstruction in our patients was > 90 mm Hg, which is higher than in other series cited in the literature; secondly, early operation was refused in some cases because of a lack of parental understanding of the child’s condition and consent was withheld until the child’s condition had deteriorated. In this regard, educating parents is one of our primary goals. In addition, the residual peak gradient was higher than in other series; this might indicate a need for more aggressive resection or insertion of a larger size of valve.
The Konno-Rastan procedure using a mechanical prosthesis for valve replacement can be performed with acceptable mortality and morbidity in this difficult group of patients. We acknowledge the limitations of this retrospective study with a small number of patients and short follow-up period. Even with current advances, the problems of mortality and heart block have not been overcome. Nevertheless, we recommend this procedure in patients with diffuse subaortic stenosis associated with an abnormal aortic valve, tunnel subaortic stenosis with hypoplastic aortic annulus, or multilevel LVOT obstruction, and in patients with a small aortic annulus requiring AVR. With the good experience obtained with the Ross-Konno technique and the aortoseptal approach, these operations probably will become more accepted in the future, especially in younger children and neonates, and the need for the classic Konno-Rastan procedure is diminishing. The modified Konno procedure should be reserved for those cases with a normal aortic valve and annulus. In patients with complex LVOT obstruction, the aims of the surgeon should be adequate relief of obstruction and preservation of the native aortic valve where possible, with all the above procedures in mind, the surgeon can choose the appropriate technique to achieve good results.
|
ACKNOWLEDGMENTS
|
|---|
We would like to thank Dr. G Omrani, Dr. N Givtaj, Dr. A Yaghoubi, Dr. B Baharestani, and Dr. M Gholampour for their contribution to this paper.
|
REFERENCES
|
|---|
- Rastan H, Koncz J. Plastic enlargement of the left ventricular outflow tract. A new operative method. Thoraxchir Vask Chir 1975;23:169–75.[Medline]
- Konno S, Imai Y, Iida Y, Nakajima M, Tatsuno K. A new method for prosthetic valve replacement in congenital aortic stenosis associated with hypoplasia of the aortic valve ring. J Thorac Cardiovasc Surg 1975;70:909–17.[Abstract]
- Kirklin JW, Barratt-Boyes BG. In: Kirklin JW, Barratt-Boyes BG, editors. Cardiac surgery. 2nd ed. NewYork: Churchill-Livingstone, 1993:1223.
- Cooley DA, Garrett JR. Septoplasty for left ventricular outflow obstruction without aortic valve replacement: a new technique. Ann Thorac Surg 1986;42:445–8.[Abstract]
- Rastan H, Koncz J. Aortoventriculoplasty: a new technique for the treatment of left ventricular outflow tract obstruction. J Thorac Cardiovasc Surg 1976;71:920–7.[Abstract]
- Kouchoukos NT, Blackstone EH, Doty DB, Hanley FL, Karp RB. In: Kirklin JW, Barratt-Boyes BG, editors. Cardiac surgery. Vol 2. 3rd ed. Salt Lake City: Churchill-Livingstone, 2003:1265–310.
- Chevers N. Observations of the disease of the orifice and valves of the aorta. Guys Hosp Rep 1842;7:387–442.
- Spencer FC, Neill CA, Bahnson HT. The treatment of congenital aortic stenosis with valvotomy during cardiopulmonary bypass. Surgery 1958;44:109–24.[Medline]
- Spencer FC, Neill CA, Sank L, Bahnson HT. Anatomical variations in 46 patients with congenital aortic stenosis. Am Surg 1960;26:204–16.[Medline]
- Vouhe PR, Neveux JY. Surgical management of diffuse subaortic stenosis: an integrated approach. Ann Thorac Surg 1991;52:654–62.[Abstract]
- Stewart JR, Merrill WH, Hammon JW Jr, Graham TP Jr, Bender HW Jr. Reappraisal of localized resection for subvalvar aortic stenosis. Ann Thorac Surg 1990;50:197–203.[Abstract]
- Somerville J, Stone S, Ross D. Fate of patients with fixed subaortic stenosis after surgical removal. Br Heart J 1980;43:629–47.[Abstract/Free Full Text]
- Cain T, Campbell D, Paton B, Clarke D. Operation for discrete subvalvular aortic stenosis. J Thorac Cardiovasc Surg 1984;87:366–70.[Abstract]
- Erez E, Kanter KR, Tam VK, Williams WH. Konno aortoventriculoplasty in children and adolescents: from prosthetic valves to the Ross operation. Ann Thorac Surg 2002;74:122–6.[Abstract/Free Full Text]
- Fleming WH, Sarafian LB. Aortic valve replacement with concomitant aortoventriculoplasty in children and young adults: long-term follow-up. Ann Thorac Surg 1987;43:575–8.[Abstract]
- Cobanoglu A, Thyagarajan GK, Dobbs J. Konno-aortoventriculoplasty with mechanical prosthesis in dealing with small aortic root: a good surgical option. Eur J Cardiothorac Surg 1997;12;766–70.[Abstract]
- Alexiou C, McDonald A, Langley SM, Dalrymple-Hay MJ, Haw MP, Monro JL. Aortic valve replacement in children: are mechanical prostheses a good option? Eur J Cardiothorac Surg 2000;17:125–33.[Abstract/Free Full Text]
- Mazzitelli D, Guenther T, Schreiber C, Wottke M, Michel J, Meisner H. Aortic valve replacement in children: are we on the right track? Eur J Cardiothorac Surg 1998;13:565–71.
- Reddy VM, Rajasinghe HA, Teitel DF, Haas GS, Hanley FL. Aortoventriculoplasty with pulmonary autograft: the "Ross-Konno" procedure. J Thorac Cardiovasc Surg 1996;111:158–67.[Abstract/Free Full Text]
- Starnes VA, Luciani GB, Wells WJ, Allen RB, Lewis AB. Aortic root replacement with the pulmonary autograft in children with complex left heart obstruction. Ann Thorac Surg 1996;62:442–9.[Abstract/Free Full Text]
This article has been cited by other articles:
|
|
|
|
 
M.-E. Nepveu, J. Cogan, R. Cartier, and A. Y. Denault
Severe Subaortic Stenosis
Anesth. Analg.,
July 1, 2007;
105(1):
34 - 35.
[Full Text]
[PDF]
|
|
|
TOP
ABSTRACT
INTRODUCTION
