| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH | TABLE OF CONTENTS |
|
|
|
|||||||
|
|||||||||
Division of Cardiac Surgery, Children's Hospital Heart Institute, and Division of Cardiothoracic Surgery, Children's Hospital, Denver, Colorado
Accepted for publication March 18, 2008.
* Address correspondence to Dr Malhotra, 300 Pasteur Dr, Falk CVRB, Department of Cardiothoracic Surgery, Stanford University, Stanford, CA 94305 (Email: spm{at}stanford.edu).
Presented at the Fifty-fourth Annual Meeting of the Southern Thoracic Surgical Association, Bonita Springs, FL, Nov 7–10, 2007.
 |
Abstract |
|---|
 Top Abstract IntroductionPatients and MethodsResultsCommentDiscussionReferences |
|---|
Methods: Between January 1983 and March 2007, 31 patients underwent reoperation for LAVVR after AVSD repair (23 valve repairs and 8 valve replacements). Median age at primary repair was 5.0 months and time to reoperation was 5.0 months. The distribution of AVSD morphology was 9 primum, 5 transitional, and 17 complete.
Results: Early postoperative mortality was 6.4% (2 of 31). Survival at 10 years was 88.1%. At a mean follow-up of 8.2 years, 86% of hospital survivors were in New York Heart Association class I. Overall freedom from reintervention at 10 years was 67.2%. Among patients undergoing primary repair, 6 of 23 underwent subsequent replacement. Follow-up LAVVR in those who did not require subsequent valve replacement was mild or less in 92.8%. Factors that demonstrated a trend toward durable repair included the use of patch augmentation rather than primary cleft closure (p = 0.02) and earlier timing to repair (less than 2 months; p = 0.03). Significant cardiomyopathy developed in 21.4% of patients after prosthetic valve replacement (3 of 14).
Conclusions: Surgical management of LAVVR after AVSD repair can be performed with excellent midterm outcomes. However, both repair and replacement are associated with a high incidence of reoperation. Nonetheless, an aggressive reparative approach should be pursued to avoid the morbidity of pediatric left atrioventricular valve replacement that includes anticoagulation, inevitable reoperation, and cardiomyopathy.
|
Introduction |
|---|
|
TopAbstractIntroductionPatients and MethodsResultsCommentDiscussionReferences |
|---|
Management of LAVVR after AVSD repair presents challenges for the surgeon. As the morbidity of prosthetic left atrioventricular valve replacement in children is not trivial, a reparative approach is preferable. However, repair of a previously repaired valve subjected to the progressive volume load of ongoing LAVVR can be technically demanding, and occasionally valve replacement may be necessary. Not infrequently, the repaired valve may require subsequent reoperation for recurrent regurgitation.
This report examines the outcomes of patients reoperated for LAVVR after AVSD repair. The focus is on the factors impacting durability of repair and need for prosthetic valve replacement.
|
Patients and Methods |
|---|
|
TopAbstractIntroductionPatients and MethodsResultsCommentDiscussionReferences |
|---|
Data were collected from hospital records, operative reports, and echocardiographic studies. Follow-up information was obtained from the most recent patient assessment at the close of the study in March 2007 by the pediatric cardiologist or referring pediatrician at a median period of 7.0 years after surgery (range, 3 months to 23.1 years). Valve function was assessed before AVSD repair, after AVSD repair, before reoperation, and at follow-up. Regurgitation was quantified by color Doppler echocardiography, using the width of the vena contracta in two orthogonal planes to stratify severity into a scale of 0 to 4. Clinical status was determined from clinic notes and reported according to the New York Heart Association (NYHA) scale.
Patient Characteristics
Morphologically, 17 patients had a complete AVSD, 5 had a transitional defect, and 9 patients had a primum defect. There were 13 males and 18 females. Trisomy 21 was present in 48.3% (15 of 31). Six patients had coarctation of the aorta repaired at the time of AVSD repair. Four patients had greater than grade 2 LAVVR before AVSD repair. A double orifice left atrioventricular valve was present in 4 patients.
Repair of AVSD was performed at a median age of 5.0 months (range, 1.1 months to 7.0 years). The median age at reoperation on the left atrioventricular valve was 12.6 months (1.8 months to 33.0 years). The median interval from initial AVSD repair was 5.0 months (2 days to 26.0 years).
Surgical Technique
Initial AVSD repair was performed using standard techniques specific for the type of defect present. Complete AVSDs were repaired with either a one- or two-patch technique, depending on surgeon preference. Transitional defects were repaired by primary VSD closure and pericardial patch ASD closure. Isolated primum defects were closed with autologous pericardium. Closure of the zone of apposition was performed at initial repair in 21 patients (68%). This was accomplished using interrupted 6-0 polypropylene sutures at the point of coaptation after saline loading of the left ventricle.
At reoperation, the left atrioventricular valve was carefully inspected to assess feasibility of valve repair. Valve repair was successfully performed in 23 patients (74%) and 8 (26%) required valve replacement. Patient characteristics for both groups are outlined in Table 1. Repair techniques included isolated cleft closure in 15 (65%), cleft closure with patch leaflet augmentation in 6 (26%), and cleft closure with valvuloplasty in 2 (8.7%). Concomitant procedures among patients with initial valve repair included tricuspid valvuloplasty in 3, subaortic resection in 2, and residual VSD closure in 1.
|
Data Analysis
Statistical analysis was performed with Prism version 5.0 (Graphpad, San Diego, California). Data are described as median with ranges unless stated otherwise. Serial data are compared between groups using Student's t test. Risk factors were assessed using log-rank analysis. Survival and freedom from reoperation was determined by Kaplan-Meier analysis.
|
Results |
|---|
|
TopAbstractIntroductionPatients and MethodsResultsCommentDiscussionReferences |
|---|
Late death occurred in 1 patient in whom progressive cardiomyopathy developed after valve replacement, necessitating heart transplantation. This patient died of complications secondary to severe chronic rejection.
Survival
Overall survival at 1, 5, and 10 years was 93.4%, 89.0%, and 89.0%, respectively (Fig 1). There was no significant difference in survival at 10 years between patients who underwent valve repair or replacement (91.1% versus 83.3%, p = 0.82).
|
Among patients who underwent valve repair, 6 subsequently required prosthetic valve replacement and 1 underwent repeat valve repair. Among patients in the replacement group, 3 underwent repeat valve replacement. Freedom from mitral reoperation at 5 years was 76.4% in the repair group and 83.3% in the replacement group; however, this difference was not statistically significant (p = 0.62; Fig 2).
|
Need for Pacemaker Implantation
Pacemaker placement was required in 8 patients (25%). In this series, patients who underwent valve replacement had a significantly higher incidence of pacemaker insertion than did patients who underwent valve repair (62.5% versus 13.0%, p = 0.005).
Durability of Left Atrioventricular Valve Repair
At follow-up, 71.4% of operative survivors of valve repair (15 of 21) were free of prosthetic valve replacement. The median time to valve replacement after recurrent LAVVR was 3.3 years. Those with a durable repair had mild or less LAVVR in 93.3% (14 of 15) at recent echocardiography. The remaining patient had moderate LAVVR, was stable on serial echocardiograms, and was clinically asymptomatic.
Analysis of factors impacting durability of valve repair determined that cleft closure alone at the time of repair posed a higher risk for subsequent valve replacement than if leaflet patch augmentation was performed concomitantly (40% versus 0%, p = 0.02). Longer interval to repair (more than 2 months) was also an important predictor of repair failure (41.6% versus 9%, p = 0.03).
Change in Functional Status
Clinical status, as assessed by the NYHA classification, improved after surgery for LAVVR. At time of presentation, 48.9% (14 of 29) were in NYHA class I or II. After surgery, 90% (26 of 29) were in NYHA class I or II. Patients with an intact left atrioventricular valve repair had a trend toward improved NYHA status compared with patients requiring valve replacement at either the first or second reoperation. At follow-up, 86.7% patients (13 of 15) with a durable repair were in NYHA class I, compared with 57.1% (8 of 14) after valve replacement (Fig 3).
|
|
Comment |
|---|
|
TopAbstractIntroductionPatients and MethodsResultsCommentDiscussionReferences |
|---|
Management of recurrent left atrioventricular valve regurgitation in the pediatric population is especially problematic as the possibility of mechanical valve replacement and its attendant complications must be weighed judiciously. These results certainly confirm those concerns. Patients who required a mitral prosthesis either at initial reoperation or second reoperation were at risk for important systolic dysfunction. This cohort also had a significant incidence of complete heart block. Undoubtedly, the unpredictable location of the atrioventricular node in the setting of atrioventricular septal defects renders the node vulnerable to injury during reoperations on the left atrioventricular valve. Moran and colleagues [12] reported a 37% incidence of heart block after left atrioventricular valve replacement after correction of AVSDs. In addition to standard complications of mechanical prostheses including endocarditis and anticoagulant-related complications, somatic outgrowth must also be considered in the context of prosthetic valve replacement in the pediatric population.
In analyzing differences between the subgroups of patients undergoing repair or replacement at initial reoperation, the only factor with statistical significance was surgical era. Improvements in surgical technique, advances in myocardial protection, and experience with intraoperative transesophageal echocardiography all may contribute to the increased rate of valve repair at the time of surgery.
Interestingly, patients who required valve replacement had nearly double the interval to reoperation from time of AVSD repair than those who were reparable. Intuitively, this makes sense, as LAVVR leads to left ventricular failure from progressive volume overload. With time, this process will promote worsening LAVVR due to the pathological geometric adaptations of the ventricle and ongoing structural damage to the mitral leaflets and apparatus. This serves to further complicate the decision making for patients with LAVVR after AVSD, as deferring surgery may limit intraoperative reparative options.
This study revealed that the left atrioventricular valve reoperation rate was especially pronounced in those undergoing repair. However, it is important to realize that those who developed recurrent LAVVR after repair were able to defer valve replacement over 3 years, on average. Moran and coworkers [12] found a similar increase in reoperation rate in the valve repair group when compared with the valve replacement group.
An identifiable technical factor that limited repair durability was isolated cleft closure. When annuloplasty or leaflet patch augmentation was performed alone or in conjunction with cleft closure, no patients required subsequent valve replacement, and one underwent successful repaired at a second reoperation. Poirer and coworkers [13] reported favorable results in 8 patients who had leaflet augmentation with glutaraldehyde-treated pericardium for LAVVR after AVSD repair. Two of these patients had recurrent LAVVR and were successfully repaired, and no patient required valve replacement. The failure of simple cleft closure is instructive, as it is indicative of damaged or dysplastic valve leaflets that are vulnerable to progressive damage as a result of prolonged exposure to the increased volume load resulting from regurgitation of the systemic atrioventricular valve. In our experience, the addition of leaflet augmentation or other valvuloplasty measures act to promote valve competency.
In conclusion, reoperation for LAVVR after AVSD repair leads to a significant improvement in functional status with minimal operative mortality. In the majority of cases, a durable repair can be achieved using aggressive valvuloplasty techniques. Even in cases of recurrent LAVVR, valve replacement can be deferred until the patient is older, potentially decreasing the requirement for future replacements.
|
Discussion |
|---|
|
TopAbstractIntroductionPatients and MethodsResultsCommentDiscussionReferences |
|---|
First of all, only 68% of this patient series had closure of the cleft in the mitral valve at the initial surgical procedure. Their incidence of reoperations for mitral regurgitation is pretty low, with 31 of 378, or 8%. Only 50% of their patients had Down syndrome, and many of our patient populations with at least complete atrioventricular septal defect have a much higher incidence of Down syndrome. Forty-five percent of their reoperations were in children who initially had incomplete atrioventricular canals or transitional atrioventricular canals, which is a bit unusual. The primary risk factor for reoperation was the era of surgery. One third of the patients who had one reoperation also required a second reoperation, and they advocate that anterior leaflet extension with a pericardial patch eliminated the need for the second reoperation, and lastly, 30% of the patients who required a reoperation ended up with a mitral prosthesis.
My first question, since the only risk fact other for reoperation was the era of surgery and since 32% of the patients didn't have the cleft closed at the initial operation, did the later era of surgery have a higher incidence of cleft closure?
DR MALHOTRA: Thank you for those comments, Dr Brown. With respect to whether or not the cleft was closed, at least in the last 15 years, the practice has been to close the cleft in all patients and probably the majority of the patients before then in all the repairs. Most of the time, the cleft was left not closed is because it would have created stenosis, and that did not change over time. The preference was to close the cleft over the majority of the range of this study.
I agree that the percentage of patients with Down's is low among the patients who required a reoperation. I think that may speak to the fact that in just reviewing our patients with a complete defect, about three quarters of the patients had Down's syndrome. Non-Down's canals are more challenging to repair because of a lack of leaflet tissue, and as a result, may be more prone to require a reoperation.
DR BROWN: I would agree with that statement. The other thing that we have learned with time is that we have altered our cleft closure technique, and by using tiny little pericardial pledgets on the suture material, we have gone actually to Gore-Tex suture material because it becomes endothelialized, and we think that our incidence of cleft dehiscence has greatly decreased.
My next question is, will the pericardial patch augmentation of the anterior leaflet be durable since this tissue has a tendency to calcify over time? Do you think these anterior leaflet augmentations are really going to be a durable fix for these recurrent patients?
DR MALHOTRA: They have held up over time. That is a good question. I think, again, the number of patients who actually received a pericardial patch enlargement was too small to give a thorough analysis. But I know the group from Toronto has published this technique and is quite satisfied with their results.
DR BROWN: The only other comment I want to make is, I dread seeing patients with complete atrioventricular canal and mitral regurgitation because I think they have a deficiency in leaflet tissue oftentimes, and they are a much more difficult group to repair, and I think that is one time that the kids with Down syndrome get a little bit of a break.
Thank you.
DR CONSTANTINE MAVROUDIS (Chicago, IL): Doctor Brown, do you mind staying at the microphone so that you might address the following question as well? If you have a patient with non-Down's atrioventricular canal, do you do anything different with the left sided atrioventricular valve reconstruction? I believe that we all have a level of anxiety when we approach the non-Down's patient with complete atrioventricular canal even though there are no documented data to support that these valves are more difficult to repair. So do you do anything different at the first operation in this kind of patient to minimize atrioventricular valve regurgitation?
DR BROWN: Obviously, we go about the operation similarly. If we find out that there is a deficiency in the anterior leaflet tissue, we try to do something about it. Frequently, if we can, we will advance the posterior leaflet up so that it will meet the anterior leaflet as long as we don't produce a stenosis. But it is a tough group, and I have to admit that what I use on one patient I may not use on the other. I think this idea of anterior leaflet augmentation sounds good. I just don't have much experience with it and don't know whether it is going to be durable or not.
DR MALHOTRA: One other technique I think can be useful in that situation when you have a deficiency in one of the leaflet tissue is to use a suture annuloplasty, partial annuloplasty, to take the tension off and bring the leaflets better to coaptation.
DR ROSS M. UNGERLEIDER (Portland, OR): A couple of quick questions for you.
In your table of how you repaired the valves, it looked like it was exclusionary, that is, it was a cleft repair or an annuloplasty. Did you have patients in whom you did both?
DR MALHOTRA: Yes. That was not as clear as it should have been. I wanted to emphasize that there was a group that just had isolated cleft closure, that when you went to reoperate it was found that the cleft closure had dehisced, and I think just closing the cleft at that time is probably not ideal, but the other patients with the patch augmentation or annuloplasty, the majority of them had a cleft closure at the same time.
DR UNGERLEIDER: We have seen some of these patients come back in whom we have done a cleft closure, but there is deficiency of the tissue, and a little annuloplasty seems to help that, especially in these patients who are a little bit older when they come back for their re-repair.
The other question, and it may be in your manuscript, which I haven't seen, is, has there been a variation in the initial repair technique, that is, a one- versus a two-patch or a modified one-patch, and have you been able to correlate that with some of the late outcome in terms of valve function?
DR MALHOTRA: I think the literature has reflected that outcomes are generally similar among the one-patch, two-patch, and Australian techniques. But I do think in our series perhaps the earlier cases were done using a one-patch technique, and over the last 15 years at Denver a two-patch technique is usually preferred. I don't think the literature has borne that out to be a risk factor in terms of recurrent mitral regurgitation.
|
References |
|---|
|
TopAbstractIntroductionPatients and MethodsResultsCommentDiscussionReferences |
|---|
This article has been cited by other articles:
|
|
 |
|
  O. Birim, M. van Gameren, P. L. de Jong, M. Witsenburg, L. van Osch-Gevers, and A. J.J.C. Bogers Outcome after reoperation for atrioventricular septal defect repair Interactive CardioVascular and Thoracic Surgery, July 1, 2009; 9(1): 83 - 87. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 J. M. Stulak, H. M. Burkhart, J. A. Dearani, H. V. Schaff, F. Cetta, R. D. Barnes, and F. J. Puga Reoperations After Initial Repair of Complete Atrioventricular Septal Defect. Ann. Thorac. Surg., June 1, 2009; 87(6): 1872 - 1878. [Abstract] [Full Text] [PDF]
|
|
| ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH | TABLE OF CONTENTS |
| ANN THORAC SURG | ASIAN CARDIOVASC THORAC ANN | EUR J CARDIOTHORAC SURG |
| J THORAC CARDIOVASC SURG | ICVTS | ALL CTSNet JOURNALS |
