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Double-Orifice Left Atrioventricular Valve in Patients With Atrioventricular Septal Defects: Surgical Strategies and Outcome
Double-Orifice Left Atrioventricular Valve in Patients With Atrioventricular Septal Defects: Surgical Strategies and Outcome Vikas Sharma, MD, Harold M. Burkhart, MD, Hartzell V. Schaff, MD, Allison K. Cabalka, MD, Martha A. Grogan, MD, and Joseph A. Dearani, MD
Background. The surgical management of double orifice left atrioventricular valve (DOLAVV) in atrioventricular septal defects (AVSD) can be challenging and has important surgical implications. Methods. Between 1961 and 2009, 44 patients with DOLAVV associated with AVSD were reviewed; this constituted 6.7% of cases of AVSD. The median age at operation was 6.6 years (range 2 months–70 years). DOLAVV was associated with partial, intermediate, and complete AVSD in 28 patients (64%), 1 patient (2%), and 15 patients (34%), respectively. Results. Forty-one patients (93%) had partial or complete closure of the zone of apposition (ZOA), and in 3 patients (7%), the ZOA was left open. The accessory orifice was found to be regurgitant in 4 patients, and in all 4 patients it was closed. Four patients had partial annuloplasties. Early mortality consisted of 1 death (2.2%). This was a patient in whom the tissue bridge was
divided and severe regurgitation resulted. Median follow-up was 10.3 years (maximum, 36 years). Three adult patients required mitral valve replacement for severe mitral regurgitation (MR) at 3, 11, and 20 years, respectively. Two of these patients experienced progression of MR resulting from an unsutured ZOA. There were 3 late deaths (6%). One death occurred after mitral valve replacement and the others died of noncardiac causes. No patient had hemodynamically significant mitral stenosis. Conclusions. Repair of DOLAVV in AVSD can be performed with low risk, excellent late survival, and freedom from reoperation. The ZOA is typically closed unless the valve area appears small. In the majority of patients, the accessory orifice is competent and can be left alone. Late repeated repair may be difficult because of leaflet dysplasia. (Ann Thorac Surg 2012;93:2017–21) © 2012 by The Society of Thoracic Surgeons
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DOLAVV in AVSD to identify important surgical modifications necessary to achieve a good result.
ouble-orifice left atrioventricular valve (DOLAVV) is a rare congenital cardiac abnormality. DOLAVV was found in 1% of autopsied cases of congenital heart disease in the cardiac registry of Children’s Hospital, Boston [1]. It can be found as an isolated anomaly [2] or with other associated heart diseases, most commonly atrioventricular septal defects (AVSDs) [3, 4]. Since its first recognition by Greenfield [5] in 1867, more than 230 cases have been described in the literature [6]. The hemodynamic significance of DOLAVV in AVSD ranges from a normally functioning valve that is recognized as an incidental finding on autopsy, open heart surgical procedures, or echocardiography, to a less frequent mitral valve regurgitation or stenosis. Irrespective of whether the valve is stenotic or regurgitant, DOLAVV may present a challenge to any surgeon because of its atypical anatomy. Hence recognition of DOLAVV and awareness of the anatomic variations is important. We reviewed our outcomes of surgical management of
Accepted for publication Feb 14, 2012. Presented at the Fifty-eighth Annual Meeting of the Southern Thoracic Surgical Association, San Antonio, TX, Nov 9 –12, 2011. Address correspondence to Dr Burkhart, Division of Cardiovascular Surgery, Mayo Clinic College of Medicine, 200 First St SW, Rochester, MN 55905; e-mail: [email protected].
© 2012 by The Society of Thoracic Surgeons Published by Elsevier Inc
Patients and Methods Demographic and other patient-related data were obtained from Mayo Clinic medical records. Follow-up information was obtained from subsequent clinic visits, written correspondence from local physicians, and questionnaires mailed to patients or families. The Mayo Foundation Institutional Review Board approved this study, and all patients or their families gave written informed consent. Between 1961 and 2009, 657 patients underwent repair of AVSD at the Mayo Clinic. A review of operative notes identified 44 patients who had associated DOLAVV, an incidence of 6.7%. The median age at operation was 6.6 years (range 2 months–70 years). There were 28 female patients (64%) and 16 male patients (36%). Of the 44 patients with DOLAVV, 28 patients (64%) had partial, 1 patient (2%) had intermediate, and 15 patients (34%) had complete AVSD. Forty-one patients (93%) had an eccentric variety of DOLAVV with a small accessory orifice, whereas 3 patients (7%) had almost equally sized orifices. The accessory orifice was located near the posterior bridging leaflet in 37 patients (90%) and near the anterior 0003-4975/$36.00 doi:10.1016/j.athoracsur.2012.02.055
PEDIATRIC CARDIAC
Divisions of Cardiovascular Surgery, Pediatric Cardiology, and Divisions of Cardiovascular Diseases, Mayo Clinic, Rochester, Minnesota
2018
SHARMA ET AL DOUBLE-ORIFICE LEFT ATRIOVENTRICULAR VALVE
Ann Thorac Surg 2012;93:2017–21
Table 1. Associated Anomalies (n ⫽ 7) Anomaly
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Fig 1. Eccentric variety of double-orifice left atrioventricular valve (DOLAVV) with accessory orifice near anterior bridging leaflet (ABL). (AAO ⫽ anterior accessory orifice; ML ⫽ mural leaflet; PBL ⫽ posterior bridging leaflet; TBATO ⫽ tissue bridge between accessory and true orifices; TV ⫽ tricuspid valve.)
bridging leaflet in 4 patients (10%) (Figs 1, 2). Preoperative echocardiography demonstrated trivial or no mitral regurgitation (MR) in 9 patients (20%) and moderate to severe regurgitation in 35 patients (80%). No patient had significant mitral stenosis preoperatively. Associated anomalies were present in 7 patients (16%) (Table 1). Our operative management evolved during the course of this experience. The basic principles involved a careful assessment of the mitral valve anatomy by routine use of intraoperative transesophageal echocardiography (TEE), to look especially for preoperative left atrioventricular valve (LAVV) stenosis and the site of regurgitation, eg, the zone of apposition (ZOA) or the accessory orifice. The ZOA was typically completely closed. Partial closure was carried out in patients who had closure of the accessory orifice when there was a concern for creation of a stenotic valve. The valve was tested so that the appropriate compromise could be reached whereby the MR was eliminated without causing significant mitral stenosis. A competent accessory orifice was left untouched. In a few patients in whom there was MR through a small accessory orifice, the orifice was closed with a pericardial patch. Residual areas of valve leakage were treated by
Common atrium Persistent left superior vena cava Patent ductus arteriosus Anomalous pulmonary venous drainage Cor triatriatum Dextrocardia Pulmonary stenosis Wolff-Parkinson-White syndrome
No. of Patients 4 3 2 1 1 1 1 1
localized annuloplasty. After weaning from bypass, all valves were checked by intraoperative TEE.
Statistical Analysis Statistical analysis was done using JMP 9 analytical software, Windows version (SAS Institute, Cary, NC). Results are presented as absolute numbers with respective percentages when appropriate. Continuous variables with skewed distribution are reported as median range. The KaplanMeier product-limit model has been used to estimate late survival as well as late freedom from reoperation.
Results Early Results Of the 44 patients who underwent repair, 42 (95%) had primary repair and 2 (5%) had repeated repair of LAVV for a failed repair done elsewhere. Complete closure of the ZOA was performed in 32 patients (73%), whereas 9 patients (20%) had partial cleft closure. In 3 patients (7%), the cleft was left open. In 4 patients (9%), the accessory orifice was found to be regurgitant and was closed in all 4 patients. Four patients underwent eccentric annuloplasties for residual leaks after repair. In the 2 patients who underwent repeated repair, the regurgitation was through the accessory orifice and it was closed with a pericardial patch. Ten patients underwent associated cardiac procedures (Table 2). Early mortality occurred in 1 patient (2.2%). This patient was operated on in 1967 at the age of 5 months for a partial AV canal defect with severe MR. The accessory orifice was thought to be a perforation; the connecting bridge was divided back to the commissure and closed with a pericardial patch. This resulted in severe mitral Table 2. Associated Procedures (n ⫽ 10) Procedure
Fig 2. Pathologic specimen showing accessory orifice (A) and cleft in left atrioventricular valve (B).
Tricuspid annuloplasty Pulmonary artery debanding Ligation of patent ductus arteriosus Division of accessory conduction bundles Excision of cor triatriatum Intraatrial baffle repair Pulmonary valvotomy and infundibulotomy
No. of Patients 4 3 2 1 1 1 1
valve regurgitation that proved to be unrepairable despite multiple attempts. The patient was unable to be weaned from cardiopulmonary bypass.
Late Results Follow-up was complete, with a median of 10.3 years (maximum, 36 years). There were 3 late deaths (6%). One patient underwent LAVV replacement for severe MR, with tricuspid regurgitation and patch dehiscence 3 years after the original repair. This patient died postoperatively as a result of low cardiac output syndrome with multisystem organ failure. The other 2 patients died of noncardiac causes. Overall actuarial survival was estimated at 93% and 86% at 5 and 15 years, respectively. Postoperative echocardiography showed no or trivial LAVV regurgitation in 17 patients (41%) and mild regurgitation in 21 patients (49%). Moderate to severe regurgitation was present in 5 patients (12%). Three adult patients required LAVV replacement for progressive MR at 3, 11, and 20 years, respectively. The mechanism of regurgitation was through the unsutured ZOA in 2 patients and through the accessory orifice in 1 patient. Repeated repair was unsuccessful because of concomitant leaflet dysplasia and an inability to achieve a competent valve without creating stenosis. Freedom from reoperation was estimated at 96% and 87% at 5 and 15 years, respectively. LAVV stenosis was uncommon; 4 patients (9%) had mild (mean gradient ⬍ 5 mm Hg) LAVV stenosis. No patients had hemodynamically significant stenosis requiring intervention. Of the 40 late survivors who have been followed up, all are in New York Heart Association functional class I (80%) or class II (20%).
Comment DOLAVV is a rare malformation first described in a postmortem study in 1876 [5]. Since then only 2 published series of DOLAVV have appeared [7, 8] in addition to a number of case reports [9 –11]. DOLAVV is characterized by 2 valve orifices, usually with a separate subvalvular apparatus for each orifice. The presence of tendinous attachments to both openings distinguishes DOLAVV from acquired lesions such as perforation or partial fusion of valve leaflets caused by inflammatory lesions, perforated aneurysm of a leaflet, traumatic ruptures, and complications of interventional procedures (eg, balloon valvotomy) [12]. The morphogenetic mechanism of DOLAVV is explained by an abnormal union into a single structure between the dorsal endocardial and left lateral endocardial cushions during the early developmental stage [13]. The most common associated anomalies reported in the literature are, in decreasing order of frequency, AVSD, bicuspid aortic valve, and coarctation of the aorta, which was the same in our series. Various classification schemes have been published on the basis of size and location of 2 orifices [6, 14]. Eccentric or hole type is the most common variety of DOLAVV (accounting for about 85% of cases), which is characterized by a small accessory orifice situated at either the anterolateral or posteromedial commissure. Other anomalies of the
SHARMA ET AL DOUBLE-ORIFICE LEFT ATRIOVENTRICULAR VALVE
2019
valve apparatus, such as accessory papillary muscles, fused papillary muscles, and crossing chordae tendineae, are commonly present. In about 15% of patients, a central bridge of fibrous or abnormal leaflet tissue connects the 2 leaflets of the mitral valve, dividing the orifice into medial and lateral parts; this is the central or bridge type. These 2 openings may be equal or unequal. The papillary muscles are usually normal, with chordae surrounding each orifice inserting into 1 papillary muscle. In some patients, 2 mitral annuluses and valves— each with its own set of leaflets, commissures, chordae, and papillary muscles—are present. In our series, the eccentric variety was present in 41 patients (93%). According to the severity of lesions and clinical status, the treatment includes leaving the valve uncorrected, valvular repair, or valve replacement. The surgical series reporting repair of DOLAVV in AVSD are few, and repair techniques are varied. The type of operation should depend on the anatomic abnormality in the LAVV apparatus. Our surgical approach has been structured on a few basic principles. Routine use of intraoperative TEE determines the exact leaflet and subvalvular anatomy and the mechanism of valve dysfunction (usually regurgitation). As is clear from the embryologic characteristics, the bridging tissue is important in maintaining the competency of the valve, as it is a part of the leaflet complex with chordal attachments, so no attempt is made to convert the dual orifice into a single one. Division of the bridging tissue results in severe regurgitation that is not amenable to repair. We experienced this in 1 patient in the early part of this series, and it has been shown in other series in which complex repairs resulting from division of bridging tissue had disastrous consequences [15]. Our surgical approach to the DOLAVV is described here (Table 3). In general, we close the ZOA completely because studies have shown progression of LAVV regurgitation through the unsutured ZOA [16, 17]. Partial or no closure of the ZOA is performed when the overall valve area appears small, eg, a dysplastic mural leaflet, single papillary muscle, and so on. The small regurgitant accessory orifice is treated with a patch closure. When the accessory orifice is closed, we prefer partial ZOA closure to avoid valve stenosis. If the valve is severely dysplastic, which is most commonly seen after initial repair, repeated repair can be difficult. Standard mitral valve repair techniques that are used for acquired diseases (eg, artificial Gore-Tex [W. L. Gore and Associates, Newark, DE] chordae, annuloplasty bands) can be applied as needed, and valve replacement is considered as a last Table 3. Mayo Clinic Management of DOLAVV Do not divide the tissue bridge Cleft closure is routine Partial or no cleft closure if valve area is small, ie, dysplastic mural leaflet, single papillary muscle Leave a competent accessory orifice alone Regurgitant accessory orifice should be closed with a patch If accessory orifice is closed, do partial cleft closure DOLAVV ⫽ double orifice left atrioventricular valve.
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Ann Thorac Surg 2012;93:2017–21
2020
SHARMA ET AL DOUBLE-ORIFICE LEFT ATRIOVENTRICULAR VALVE
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resort. When valve replacement is necessary, some or all of the dysplastic leaflet tissue and the subvalvular apparatus should be resected to facilitate proper seating and function of the prosthesis. In conclusion, the potential presence of DOLAVV should be recognized. It occurs most commonly in patients with AVSD, and the diagnosis may not be apparent until the operation is being performed. The accessory orifice is competent in most cases and should be left untouched. Repair of DOLAVV in AVSD can be performed with a low operative risk. The ZOA is usually closed unless the valve area appears small. Late repeated repair may be difficult because of leaflet dysplasia. Longterm survival and freedom from reoperation are favorable, but lifelong surveillance is necessary.
References 1. Bano- Rodrigo A, Van Pragh S, Trowitzsch E, Van Praagh R. Double- orifice mitral valve: a study of 27 post mortem cases with developmental, diagnostic and surgical consideration. Am J Cardiol 1988;61:152– 60. 2. Lee DI, Ha JW, Chung B, Kim Y, et al. Double orifice mitral valve. Clin Cardiol 1999;22:425. 3. Warnes C, Somerville J. Double mitral valve orifice in atrioventricular defects. Br Heart J 1983;49:59 – 64. 4. Trowitzsch E, Bano Rodrigo A, Burgrer BM, Colan SD, Sanders SP. Two- dimensional echocardiographic findings in double orifice mitral valve. J Am Coll Cardiol 1985;6:383–7. 5. Greenfield W. Double mitral valve. Trans Pathol Soc (London) 1876;27:128 –9. 6. Anwar AM, McGhie JS, Meijboom FJ, Ten Cate FJ. Double orifice mitral valve by three- dimensional echocardiography. Eur J Echocardiogr 2008;9:731–2.
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7. Zalzstein E, Hamilton R, Zuker N, Levitas A, Gross GJ. Presentation, natural history and outcome in children and adolescents with double orifice mitral valve. Am J Cardiol 2004;93:1067–9. 8. Sugiyama H, Hoshiai M, Toda T, Nakazawa S. Doubleorifice mitral valve associated with noncompaction of left ventricular myocardium. Pediatrics 2006;27:746 –9. 9. Buuren FV, Faber L, Bogunovic N. Double orifice mitral valve with a normal function: an echocardiographic and MRI study of a rare finding. Eur Heart J 2011;32:137. 10. Westendorp IC, de Bruin- Bon HA, Hrudova J. Double orifice mitral valve; a coincidental finding. Eur J Echocardiogr 2006;7:463– 4. 11. Congin S, Josa M, Friexa X, Azqueta M, Mestres C, Mulet J. Mitral insufficiency with double- orifice mitral valve in an adult patient. J Thorac Cardiovasc Surg 2007;134:250 –1. 12. Das BB, Pauliks LB, Knudson OA, et al. Double-orifice mitral valve with intact atrioventricular septum: an echocardiographic study with anatomic and functional considerations. J Am Soc Echocardiogr 2005;18:231– 6. 13. Weninck ACG, Gittenberger-de Groot AC. Left and right ventricular trabecular patterns. Consequence of ventricular septation and valve development. Br Heart J 1982;48: 462– 8. 14. Warnes C, Somerville J. Double mitral valve orifice in atrioventricular defects. Br Heart J 1983;49:59 – 64. 15. Hoohenkerk GJF, Weninck ACG, Schoof PH, et al. Results of surgical repair of atrioventricular septal defects with doubleorifice left atrioventricular valve. J Thorac Cardiovasc Surg 2009;138:1167–71. 16. McGrath LB, Gonzalez LL. Actuarial survival, freedom from reoperation, and other events after repair of atrioventricular septal defects. J Thorac Cardiovasc Surg 1987; 94:582–90. 17. Pozzi M, Remig J, Fimmers R, Urban AE. Atrioventricular septal defects. Analysis of short- and medium-term results. J Thorac Cardiovasc Surg 1991;101:138 – 42.
DISCUSSION DR KARLA CHRISTIAN (Nashville, TN): Dr. Sharma, thank you for providing me with a copy of your manuscript for review in advance. This is a large series of a rare lesion with care taken to accumulate complete data with excellent results, which you presented very nicely. I have 3 questions for you, and the first question you have likely already answered but I just want clarification for my own understanding. Other than the 3 patients you presented that underwent mitral valve replacement, were there any other patients with AV canal and double-orifice mitral valve that required reoperation for residual mitral regurgitation, mitral stenosis, or other cardiac lesions in your series in either the short term or in the long term?
during redo surgery for mitral regurgitation, the valve orifice was too small. In other patients, the leaflet tissues were dysplastic and required replacement.
DR SHARMA: There were 2 patients who had subaortic stenosis and underwent surgery for relieving subaortic obstruction during follow-up. Only 3 patients underwent mitral valve replacement. There was no other intervention done for left AV valve.
DR SHARMA: Yes.
DR CHRISTIAN: On the 3 patients you mentioned who had the mitral valve replacement, did you attempt rerepairs in those patients prior to replacing the mitral valve? DR SHARMA: All 3 patients underwent attempted repairs. In 1 patient, the accessory orifice was closed in the first operation. When closure of the zone of apposition (ZOA) was attempted
DR CHRISTIAN: Were the replacements done at the time of attempted rerepair, or were those done as separate operations? DR SHARMA: No. We attempted repair and ultimately did the replacement. DR CHRISTIAN: All at the same operation?
DR CHRISTIAN: My second question is how do you assess intraoperatively for adequate size of the primary mitral orifice during cleft closure in a patient with an AV canal double-orifice mitral valve to ensure that mitral stenosis is avoided given that the primary orifice may be smaller than a patient without a double-orifice mitral valve? I am referring specifically to when the cross-clamp is on and the sutures are being placed, because you don’t want to wait until the clamp comes off and your echocardiographer is reporting that you have created mitral stenosis causing you to have to put the clamp on and take out some sutures.
DR SHARMA: Around 75% to 80% of the left AV valve area should be adequate in the postoperative period, but it might be very difficult to assess actually the size, especially with 2 separate orifices present. So we rely heavily on the preoperative TEE regarding presence of preoperative stenosis in these valves like small mural leaflet, chordal apparatus abnormalities causing subvalvular obstruction. We usually try to close the ZOA completely, unless there are compelling indications as mentioned not to close it. If we close the regurgitant accessory orifice, we try to do a partial closure of ZOA. In addition we have a very low threshold for going back on pump, if there is stenosis after coming off. DR CHRISTIAN: Thank you. My last question is, how do you address the patient with an AV canal double-orifice mitral valve with a single papillary muscle? DR SHARMA: Although in our series we didn’t have any patients who had this abnormality, this is an inherently stenotic valve. This is 1 indication in which we would like to leave the ZOA open. DR CHRISTIAN: Thank you, and these are excellent results. DR SHARMA: Thank you. DR MUHAMMAD MUMTAZ (Norfolk, VA): I really enjoyed your presentation. This is a very rare abnormality and it was very educational to hear what you have done to understand the anatomy. I have a suggestion. You made your presentation mostly as a clinical outcome series, whereas intraoperatively sometimes these are surprise findings. It may be worthwhile if you have echo pictures and other echo findings to describe findings in more detail eg, how much chordal support it had, which pap muscle did it go to, whatever information you can get, just because this is a rare abnormality. My question is specifically, did you find any patients not in an AV canal setting, because double-orifice mitral valve can occur with or without AV canal, and here you are discussing the ones that are in an AV canal setting. Have you seen any that are not in an AV canal setting, and if you have, what is the long-term outcome with them? DR SHARMA: We actually had a total of 56 patients during the retrospective review, and most of the other cases were with the left-sided obstructive lesions, like coarctation and aortic stenosis. There were few patients with single ventricle physiology and double-orifice left AV valve. The mortality was high in these cases. DR CARL L. BACKER (Chicago, IL): I want to congratulate you. I don’t know if everyone in the audience realizes this, but, to my knowledge, this is the largest series of double-orifice left AV valves ever reported. Is that accurate? DR SHARMA: Yes. This is the largest series of double-orifice left AV valve in AVSD, although there were 46 patients reported in a combined study from Israel and Sick Kids, Canada, which was a heterogeneous group of patients. DR BACKER: So this is the largest series ever reported. I want to make just a couple of comments. It looks like between writing your abstract and making your slides you made some nomen-
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2021
clature changes, which I approve of, but I would ask you to go 1 step further. It looks like you have changed double-orifice mitral valve to double-orifice left AV valve. It also looks like you have changed from “AV canal” to “atrioventricular septal defect.” Both are changes which I think Professor Anderson would be very pleased to see. You also probably need to change, though, calling the “cleft,” which is a structure that we see in an anatomically otherwise normal mitral valve without AV septal defect, to “zone of apposition,” which is the current preferred terminology. If you are going to be completely “Andersonian,” you will need to go with “zone of apposition.” I can see that Dr Jeffrey Jacobs is saying thumbs up on that one. I have a few additional comments. It is interesting that as you go through your career there are a few things that will suddenly pop into your brain that you remember from what your professors told you. I still remember what Farouk Idriss, who trained me, told me the 1 time that I saw a double-orifice left AV valve while operating with him. He said, “Carl, never, never divide that bridge of tissue.” I have always heeded that advice and I am glad to see that you are emphasizing that. For any congenital heart surgeon who suddenly sees this for the first time, that is a very important message. I am glad you have emphasized that the outcome in the 1 patient in your series where the tissue bridge was divided was not good. The second comment I will make is that a double-orifice left atrioventricular valve can be a nice opportunity for success when there is a lot of AV valve insufficiency. I recently operated on a child who had their original AVSD repair overseas, came to the United States, and had severe left AV valve insufficiency. The insufficiency was all through 1 of the 2 orifices and I closed that orifice with a small pericardial patch. It was a very nice result. The final comment I will make relates to that same patient where we applied 3-dimensional echo. I am sure that at the Mayo Clinic you are doing 3-dimensional echo on these patients, but the 3-dimensional echo was just spectacular in showing us where the AV valve insufficiency was and that it was all coming through the smaller orifice. Closing that orifice with a little piece of pericardium relieved the left AV valve insufficiency. Again, I congratulate you on reporting the world’s largest series of patients with double-orifice left AV valve. DR PETER B. MANNING (Cincinnati, OH): Really good results. I think my take home message from your study is that you treat this just like any other garden variety AV canal and the outcomes are just like any other garden variety AV canal. It would be really helpful to report outcome data from the rest of your AV canal series. Are the outcomes really the same—with the same institution, same group of surgeons? If they are, I think that would really solidify the point you are trying to make. My second question is, were most of these recognized intraoperatively or preoperatively? In my experience, many times the cardiologists don’t call this in advance and it is up to the surgeon to really look at the valve carefully before you start putting stitches in and do something silly like divide the bridging leaflet, which you have shown is a bad thing to do. DR SHARMA: This was a study spanning over 42 years, with TEE available in the later part of series. Going through the operative notes, in most of the cases it was a chance finding during the surgery.
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Ann Thorac Surg 2012;93:2017–21
Background. The surgical management of double orifice left atrioventricular valve (DOLAVV) in atrioventricular septal defects (AVSD) can be challenging and has important surgical implications. Methods. Between 1961 and 2009, 44 patients with DOLAVV associated with AVSD were reviewed; this constituted 6.7% of cases of AVSD. The median age at operation was 6.6 years (range 2 months–70 years). DOLAVV was associated with partial, intermediate, and complete AVSD in 28 patients (64%), 1 patient (2%), and 15 patients (34%), respectively. Results. Forty-one patients (93%) had partial or complete closure of the zone of apposition (ZOA), and in 3 patients (7%), the ZOA was left open. The accessory orifice was found to be regurgitant in 4 patients, and in all 4 patients it was closed. Four patients had partial annuloplasties. Early mortality consisted of 1 death (2.2%). This was a patient in whom the tissue bridge was
divided and severe regurgitation resulted. Median follow-up was 10.3 years (maximum, 36 years). Three adult patients required mitral valve replacement for severe mitral regurgitation (MR) at 3, 11, and 20 years, respectively. Two of these patients experienced progression of MR resulting from an unsutured ZOA. There were 3 late deaths (6%). One death occurred after mitral valve replacement and the others died of noncardiac causes. No patient had hemodynamically significant mitral stenosis. Conclusions. Repair of DOLAVV in AVSD can be performed with low risk, excellent late survival, and freedom from reoperation. The ZOA is typically closed unless the valve area appears small. In the majority of patients, the accessory orifice is competent and can be left alone. Late repeated repair may be difficult because of leaflet dysplasia. (Ann Thorac Surg 2012;93:2017–21) © 2012 by The Society of Thoracic Surgeons
D
DOLAVV in AVSD to identify important surgical modifications necessary to achieve a good result.
ouble-orifice left atrioventricular valve (DOLAVV) is a rare congenital cardiac abnormality. DOLAVV was found in 1% of autopsied cases of congenital heart disease in the cardiac registry of Children’s Hospital, Boston [1]. It can be found as an isolated anomaly [2] or with other associated heart diseases, most commonly atrioventricular septal defects (AVSDs) [3, 4]. Since its first recognition by Greenfield [5] in 1867, more than 230 cases have been described in the literature [6]. The hemodynamic significance of DOLAVV in AVSD ranges from a normally functioning valve that is recognized as an incidental finding on autopsy, open heart surgical procedures, or echocardiography, to a less frequent mitral valve regurgitation or stenosis. Irrespective of whether the valve is stenotic or regurgitant, DOLAVV may present a challenge to any surgeon because of its atypical anatomy. Hence recognition of DOLAVV and awareness of the anatomic variations is important. We reviewed our outcomes of surgical management of
Accepted for publication Feb 14, 2012. Presented at the Fifty-eighth Annual Meeting of the Southern Thoracic Surgical Association, San Antonio, TX, Nov 9 –12, 2011. Address correspondence to Dr Burkhart, Division of Cardiovascular Surgery, Mayo Clinic College of Medicine, 200 First St SW, Rochester, MN 55905; e-mail: [email protected].
© 2012 by The Society of Thoracic Surgeons Published by Elsevier Inc
Patients and Methods Demographic and other patient-related data were obtained from Mayo Clinic medical records. Follow-up information was obtained from subsequent clinic visits, written correspondence from local physicians, and questionnaires mailed to patients or families. The Mayo Foundation Institutional Review Board approved this study, and all patients or their families gave written informed consent. Between 1961 and 2009, 657 patients underwent repair of AVSD at the Mayo Clinic. A review of operative notes identified 44 patients who had associated DOLAVV, an incidence of 6.7%. The median age at operation was 6.6 years (range 2 months–70 years). There were 28 female patients (64%) and 16 male patients (36%). Of the 44 patients with DOLAVV, 28 patients (64%) had partial, 1 patient (2%) had intermediate, and 15 patients (34%) had complete AVSD. Forty-one patients (93%) had an eccentric variety of DOLAVV with a small accessory orifice, whereas 3 patients (7%) had almost equally sized orifices. The accessory orifice was located near the posterior bridging leaflet in 37 patients (90%) and near the anterior 0003-4975/$36.00 doi:10.1016/j.athoracsur.2012.02.055
PEDIATRIC CARDIAC
Divisions of Cardiovascular Surgery, Pediatric Cardiology, and Divisions of Cardiovascular Diseases, Mayo Clinic, Rochester, Minnesota
2018
SHARMA ET AL DOUBLE-ORIFICE LEFT ATRIOVENTRICULAR VALVE
Ann Thorac Surg 2012;93:2017–21
Table 1. Associated Anomalies (n ⫽ 7) Anomaly
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Fig 1. Eccentric variety of double-orifice left atrioventricular valve (DOLAVV) with accessory orifice near anterior bridging leaflet (ABL). (AAO ⫽ anterior accessory orifice; ML ⫽ mural leaflet; PBL ⫽ posterior bridging leaflet; TBATO ⫽ tissue bridge between accessory and true orifices; TV ⫽ tricuspid valve.)
bridging leaflet in 4 patients (10%) (Figs 1, 2). Preoperative echocardiography demonstrated trivial or no mitral regurgitation (MR) in 9 patients (20%) and moderate to severe regurgitation in 35 patients (80%). No patient had significant mitral stenosis preoperatively. Associated anomalies were present in 7 patients (16%) (Table 1). Our operative management evolved during the course of this experience. The basic principles involved a careful assessment of the mitral valve anatomy by routine use of intraoperative transesophageal echocardiography (TEE), to look especially for preoperative left atrioventricular valve (LAVV) stenosis and the site of regurgitation, eg, the zone of apposition (ZOA) or the accessory orifice. The ZOA was typically completely closed. Partial closure was carried out in patients who had closure of the accessory orifice when there was a concern for creation of a stenotic valve. The valve was tested so that the appropriate compromise could be reached whereby the MR was eliminated without causing significant mitral stenosis. A competent accessory orifice was left untouched. In a few patients in whom there was MR through a small accessory orifice, the orifice was closed with a pericardial patch. Residual areas of valve leakage were treated by
Common atrium Persistent left superior vena cava Patent ductus arteriosus Anomalous pulmonary venous drainage Cor triatriatum Dextrocardia Pulmonary stenosis Wolff-Parkinson-White syndrome
No. of Patients 4 3 2 1 1 1 1 1
localized annuloplasty. After weaning from bypass, all valves were checked by intraoperative TEE.
Statistical Analysis Statistical analysis was done using JMP 9 analytical software, Windows version (SAS Institute, Cary, NC). Results are presented as absolute numbers with respective percentages when appropriate. Continuous variables with skewed distribution are reported as median range. The KaplanMeier product-limit model has been used to estimate late survival as well as late freedom from reoperation.
Results Early Results Of the 44 patients who underwent repair, 42 (95%) had primary repair and 2 (5%) had repeated repair of LAVV for a failed repair done elsewhere. Complete closure of the ZOA was performed in 32 patients (73%), whereas 9 patients (20%) had partial cleft closure. In 3 patients (7%), the cleft was left open. In 4 patients (9%), the accessory orifice was found to be regurgitant and was closed in all 4 patients. Four patients underwent eccentric annuloplasties for residual leaks after repair. In the 2 patients who underwent repeated repair, the regurgitation was through the accessory orifice and it was closed with a pericardial patch. Ten patients underwent associated cardiac procedures (Table 2). Early mortality occurred in 1 patient (2.2%). This patient was operated on in 1967 at the age of 5 months for a partial AV canal defect with severe MR. The accessory orifice was thought to be a perforation; the connecting bridge was divided back to the commissure and closed with a pericardial patch. This resulted in severe mitral Table 2. Associated Procedures (n ⫽ 10) Procedure
Fig 2. Pathologic specimen showing accessory orifice (A) and cleft in left atrioventricular valve (B).
Tricuspid annuloplasty Pulmonary artery debanding Ligation of patent ductus arteriosus Division of accessory conduction bundles Excision of cor triatriatum Intraatrial baffle repair Pulmonary valvotomy and infundibulotomy
No. of Patients 4 3 2 1 1 1 1
valve regurgitation that proved to be unrepairable despite multiple attempts. The patient was unable to be weaned from cardiopulmonary bypass.
Late Results Follow-up was complete, with a median of 10.3 years (maximum, 36 years). There were 3 late deaths (6%). One patient underwent LAVV replacement for severe MR, with tricuspid regurgitation and patch dehiscence 3 years after the original repair. This patient died postoperatively as a result of low cardiac output syndrome with multisystem organ failure. The other 2 patients died of noncardiac causes. Overall actuarial survival was estimated at 93% and 86% at 5 and 15 years, respectively. Postoperative echocardiography showed no or trivial LAVV regurgitation in 17 patients (41%) and mild regurgitation in 21 patients (49%). Moderate to severe regurgitation was present in 5 patients (12%). Three adult patients required LAVV replacement for progressive MR at 3, 11, and 20 years, respectively. The mechanism of regurgitation was through the unsutured ZOA in 2 patients and through the accessory orifice in 1 patient. Repeated repair was unsuccessful because of concomitant leaflet dysplasia and an inability to achieve a competent valve without creating stenosis. Freedom from reoperation was estimated at 96% and 87% at 5 and 15 years, respectively. LAVV stenosis was uncommon; 4 patients (9%) had mild (mean gradient ⬍ 5 mm Hg) LAVV stenosis. No patients had hemodynamically significant stenosis requiring intervention. Of the 40 late survivors who have been followed up, all are in New York Heart Association functional class I (80%) or class II (20%).
Comment DOLAVV is a rare malformation first described in a postmortem study in 1876 [5]. Since then only 2 published series of DOLAVV have appeared [7, 8] in addition to a number of case reports [9 –11]. DOLAVV is characterized by 2 valve orifices, usually with a separate subvalvular apparatus for each orifice. The presence of tendinous attachments to both openings distinguishes DOLAVV from acquired lesions such as perforation or partial fusion of valve leaflets caused by inflammatory lesions, perforated aneurysm of a leaflet, traumatic ruptures, and complications of interventional procedures (eg, balloon valvotomy) [12]. The morphogenetic mechanism of DOLAVV is explained by an abnormal union into a single structure between the dorsal endocardial and left lateral endocardial cushions during the early developmental stage [13]. The most common associated anomalies reported in the literature are, in decreasing order of frequency, AVSD, bicuspid aortic valve, and coarctation of the aorta, which was the same in our series. Various classification schemes have been published on the basis of size and location of 2 orifices [6, 14]. Eccentric or hole type is the most common variety of DOLAVV (accounting for about 85% of cases), which is characterized by a small accessory orifice situated at either the anterolateral or posteromedial commissure. Other anomalies of the
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valve apparatus, such as accessory papillary muscles, fused papillary muscles, and crossing chordae tendineae, are commonly present. In about 15% of patients, a central bridge of fibrous or abnormal leaflet tissue connects the 2 leaflets of the mitral valve, dividing the orifice into medial and lateral parts; this is the central or bridge type. These 2 openings may be equal or unequal. The papillary muscles are usually normal, with chordae surrounding each orifice inserting into 1 papillary muscle. In some patients, 2 mitral annuluses and valves— each with its own set of leaflets, commissures, chordae, and papillary muscles—are present. In our series, the eccentric variety was present in 41 patients (93%). According to the severity of lesions and clinical status, the treatment includes leaving the valve uncorrected, valvular repair, or valve replacement. The surgical series reporting repair of DOLAVV in AVSD are few, and repair techniques are varied. The type of operation should depend on the anatomic abnormality in the LAVV apparatus. Our surgical approach has been structured on a few basic principles. Routine use of intraoperative TEE determines the exact leaflet and subvalvular anatomy and the mechanism of valve dysfunction (usually regurgitation). As is clear from the embryologic characteristics, the bridging tissue is important in maintaining the competency of the valve, as it is a part of the leaflet complex with chordal attachments, so no attempt is made to convert the dual orifice into a single one. Division of the bridging tissue results in severe regurgitation that is not amenable to repair. We experienced this in 1 patient in the early part of this series, and it has been shown in other series in which complex repairs resulting from division of bridging tissue had disastrous consequences [15]. Our surgical approach to the DOLAVV is described here (Table 3). In general, we close the ZOA completely because studies have shown progression of LAVV regurgitation through the unsutured ZOA [16, 17]. Partial or no closure of the ZOA is performed when the overall valve area appears small, eg, a dysplastic mural leaflet, single papillary muscle, and so on. The small regurgitant accessory orifice is treated with a patch closure. When the accessory orifice is closed, we prefer partial ZOA closure to avoid valve stenosis. If the valve is severely dysplastic, which is most commonly seen after initial repair, repeated repair can be difficult. Standard mitral valve repair techniques that are used for acquired diseases (eg, artificial Gore-Tex [W. L. Gore and Associates, Newark, DE] chordae, annuloplasty bands) can be applied as needed, and valve replacement is considered as a last Table 3. Mayo Clinic Management of DOLAVV Do not divide the tissue bridge Cleft closure is routine Partial or no cleft closure if valve area is small, ie, dysplastic mural leaflet, single papillary muscle Leave a competent accessory orifice alone Regurgitant accessory orifice should be closed with a patch If accessory orifice is closed, do partial cleft closure DOLAVV ⫽ double orifice left atrioventricular valve.
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resort. When valve replacement is necessary, some or all of the dysplastic leaflet tissue and the subvalvular apparatus should be resected to facilitate proper seating and function of the prosthesis. In conclusion, the potential presence of DOLAVV should be recognized. It occurs most commonly in patients with AVSD, and the diagnosis may not be apparent until the operation is being performed. The accessory orifice is competent in most cases and should be left untouched. Repair of DOLAVV in AVSD can be performed with a low operative risk. The ZOA is usually closed unless the valve area appears small. Late repeated repair may be difficult because of leaflet dysplasia. Longterm survival and freedom from reoperation are favorable, but lifelong surveillance is necessary.
References 1. Bano- Rodrigo A, Van Pragh S, Trowitzsch E, Van Praagh R. Double- orifice mitral valve: a study of 27 post mortem cases with developmental, diagnostic and surgical consideration. Am J Cardiol 1988;61:152– 60. 2. Lee DI, Ha JW, Chung B, Kim Y, et al. Double orifice mitral valve. Clin Cardiol 1999;22:425. 3. Warnes C, Somerville J. Double mitral valve orifice in atrioventricular defects. Br Heart J 1983;49:59 – 64. 4. Trowitzsch E, Bano Rodrigo A, Burgrer BM, Colan SD, Sanders SP. Two- dimensional echocardiographic findings in double orifice mitral valve. J Am Coll Cardiol 1985;6:383–7. 5. Greenfield W. Double mitral valve. Trans Pathol Soc (London) 1876;27:128 –9. 6. Anwar AM, McGhie JS, Meijboom FJ, Ten Cate FJ. Double orifice mitral valve by three- dimensional echocardiography. Eur J Echocardiogr 2008;9:731–2.
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7. Zalzstein E, Hamilton R, Zuker N, Levitas A, Gross GJ. Presentation, natural history and outcome in children and adolescents with double orifice mitral valve. Am J Cardiol 2004;93:1067–9. 8. Sugiyama H, Hoshiai M, Toda T, Nakazawa S. Doubleorifice mitral valve associated with noncompaction of left ventricular myocardium. Pediatrics 2006;27:746 –9. 9. Buuren FV, Faber L, Bogunovic N. Double orifice mitral valve with a normal function: an echocardiographic and MRI study of a rare finding. Eur Heart J 2011;32:137. 10. Westendorp IC, de Bruin- Bon HA, Hrudova J. Double orifice mitral valve; a coincidental finding. Eur J Echocardiogr 2006;7:463– 4. 11. Congin S, Josa M, Friexa X, Azqueta M, Mestres C, Mulet J. Mitral insufficiency with double- orifice mitral valve in an adult patient. J Thorac Cardiovasc Surg 2007;134:250 –1. 12. Das BB, Pauliks LB, Knudson OA, et al. Double-orifice mitral valve with intact atrioventricular septum: an echocardiographic study with anatomic and functional considerations. J Am Soc Echocardiogr 2005;18:231– 6. 13. Weninck ACG, Gittenberger-de Groot AC. Left and right ventricular trabecular patterns. Consequence of ventricular septation and valve development. Br Heart J 1982;48: 462– 8. 14. Warnes C, Somerville J. Double mitral valve orifice in atrioventricular defects. Br Heart J 1983;49:59 – 64. 15. Hoohenkerk GJF, Weninck ACG, Schoof PH, et al. Results of surgical repair of atrioventricular septal defects with doubleorifice left atrioventricular valve. J Thorac Cardiovasc Surg 2009;138:1167–71. 16. McGrath LB, Gonzalez LL. Actuarial survival, freedom from reoperation, and other events after repair of atrioventricular septal defects. J Thorac Cardiovasc Surg 1987; 94:582–90. 17. Pozzi M, Remig J, Fimmers R, Urban AE. Atrioventricular septal defects. Analysis of short- and medium-term results. J Thorac Cardiovasc Surg 1991;101:138 – 42.
DISCUSSION DR KARLA CHRISTIAN (Nashville, TN): Dr. Sharma, thank you for providing me with a copy of your manuscript for review in advance. This is a large series of a rare lesion with care taken to accumulate complete data with excellent results, which you presented very nicely. I have 3 questions for you, and the first question you have likely already answered but I just want clarification for my own understanding. Other than the 3 patients you presented that underwent mitral valve replacement, were there any other patients with AV canal and double-orifice mitral valve that required reoperation for residual mitral regurgitation, mitral stenosis, or other cardiac lesions in your series in either the short term or in the long term?
during redo surgery for mitral regurgitation, the valve orifice was too small. In other patients, the leaflet tissues were dysplastic and required replacement.
DR SHARMA: There were 2 patients who had subaortic stenosis and underwent surgery for relieving subaortic obstruction during follow-up. Only 3 patients underwent mitral valve replacement. There was no other intervention done for left AV valve.
DR SHARMA: Yes.
DR CHRISTIAN: On the 3 patients you mentioned who had the mitral valve replacement, did you attempt rerepairs in those patients prior to replacing the mitral valve? DR SHARMA: All 3 patients underwent attempted repairs. In 1 patient, the accessory orifice was closed in the first operation. When closure of the zone of apposition (ZOA) was attempted
DR CHRISTIAN: Were the replacements done at the time of attempted rerepair, or were those done as separate operations? DR SHARMA: No. We attempted repair and ultimately did the replacement. DR CHRISTIAN: All at the same operation?
DR CHRISTIAN: My second question is how do you assess intraoperatively for adequate size of the primary mitral orifice during cleft closure in a patient with an AV canal double-orifice mitral valve to ensure that mitral stenosis is avoided given that the primary orifice may be smaller than a patient without a double-orifice mitral valve? I am referring specifically to when the cross-clamp is on and the sutures are being placed, because you don’t want to wait until the clamp comes off and your echocardiographer is reporting that you have created mitral stenosis causing you to have to put the clamp on and take out some sutures.
DR SHARMA: Around 75% to 80% of the left AV valve area should be adequate in the postoperative period, but it might be very difficult to assess actually the size, especially with 2 separate orifices present. So we rely heavily on the preoperative TEE regarding presence of preoperative stenosis in these valves like small mural leaflet, chordal apparatus abnormalities causing subvalvular obstruction. We usually try to close the ZOA completely, unless there are compelling indications as mentioned not to close it. If we close the regurgitant accessory orifice, we try to do a partial closure of ZOA. In addition we have a very low threshold for going back on pump, if there is stenosis after coming off. DR CHRISTIAN: Thank you. My last question is, how do you address the patient with an AV canal double-orifice mitral valve with a single papillary muscle? DR SHARMA: Although in our series we didn’t have any patients who had this abnormality, this is an inherently stenotic valve. This is 1 indication in which we would like to leave the ZOA open. DR CHRISTIAN: Thank you, and these are excellent results. DR SHARMA: Thank you. DR MUHAMMAD MUMTAZ (Norfolk, VA): I really enjoyed your presentation. This is a very rare abnormality and it was very educational to hear what you have done to understand the anatomy. I have a suggestion. You made your presentation mostly as a clinical outcome series, whereas intraoperatively sometimes these are surprise findings. It may be worthwhile if you have echo pictures and other echo findings to describe findings in more detail eg, how much chordal support it had, which pap muscle did it go to, whatever information you can get, just because this is a rare abnormality. My question is specifically, did you find any patients not in an AV canal setting, because double-orifice mitral valve can occur with or without AV canal, and here you are discussing the ones that are in an AV canal setting. Have you seen any that are not in an AV canal setting, and if you have, what is the long-term outcome with them? DR SHARMA: We actually had a total of 56 patients during the retrospective review, and most of the other cases were with the left-sided obstructive lesions, like coarctation and aortic stenosis. There were few patients with single ventricle physiology and double-orifice left AV valve. The mortality was high in these cases. DR CARL L. BACKER (Chicago, IL): I want to congratulate you. I don’t know if everyone in the audience realizes this, but, to my knowledge, this is the largest series of double-orifice left AV valves ever reported. Is that accurate? DR SHARMA: Yes. This is the largest series of double-orifice left AV valve in AVSD, although there were 46 patients reported in a combined study from Israel and Sick Kids, Canada, which was a heterogeneous group of patients. DR BACKER: So this is the largest series ever reported. I want to make just a couple of comments. It looks like between writing your abstract and making your slides you made some nomen-
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clature changes, which I approve of, but I would ask you to go 1 step further. It looks like you have changed double-orifice mitral valve to double-orifice left AV valve. It also looks like you have changed from “AV canal” to “atrioventricular septal defect.” Both are changes which I think Professor Anderson would be very pleased to see. You also probably need to change, though, calling the “cleft,” which is a structure that we see in an anatomically otherwise normal mitral valve without AV septal defect, to “zone of apposition,” which is the current preferred terminology. If you are going to be completely “Andersonian,” you will need to go with “zone of apposition.” I can see that Dr Jeffrey Jacobs is saying thumbs up on that one. I have a few additional comments. It is interesting that as you go through your career there are a few things that will suddenly pop into your brain that you remember from what your professors told you. I still remember what Farouk Idriss, who trained me, told me the 1 time that I saw a double-orifice left AV valve while operating with him. He said, “Carl, never, never divide that bridge of tissue.” I have always heeded that advice and I am glad to see that you are emphasizing that. For any congenital heart surgeon who suddenly sees this for the first time, that is a very important message. I am glad you have emphasized that the outcome in the 1 patient in your series where the tissue bridge was divided was not good. The second comment I will make is that a double-orifice left atrioventricular valve can be a nice opportunity for success when there is a lot of AV valve insufficiency. I recently operated on a child who had their original AVSD repair overseas, came to the United States, and had severe left AV valve insufficiency. The insufficiency was all through 1 of the 2 orifices and I closed that orifice with a small pericardial patch. It was a very nice result. The final comment I will make relates to that same patient where we applied 3-dimensional echo. I am sure that at the Mayo Clinic you are doing 3-dimensional echo on these patients, but the 3-dimensional echo was just spectacular in showing us where the AV valve insufficiency was and that it was all coming through the smaller orifice. Closing that orifice with a little piece of pericardium relieved the left AV valve insufficiency. Again, I congratulate you on reporting the world’s largest series of patients with double-orifice left AV valve. DR PETER B. MANNING (Cincinnati, OH): Really good results. I think my take home message from your study is that you treat this just like any other garden variety AV canal and the outcomes are just like any other garden variety AV canal. It would be really helpful to report outcome data from the rest of your AV canal series. Are the outcomes really the same—with the same institution, same group of surgeons? If they are, I think that would really solidify the point you are trying to make. My second question is, were most of these recognized intraoperatively or preoperatively? In my experience, many times the cardiologists don’t call this in advance and it is up to the surgeon to really look at the valve carefully before you start putting stitches in and do something silly like divide the bridging leaflet, which you have shown is a bad thing to do. DR SHARMA: This was a study spanning over 42 years, with TEE available in the later part of series. Going through the operative notes, in most of the cases it was a chance finding during the surgery.
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