| JOURNAL HOME | CME HOME | THIS MONTH | PAST ISSUES | ETOC | COLLECTIONS |
| AUTHORS | REVIEWERS | EDITORIAL BOARD | FEEDBACK | RSS | HELP |
 
|
|
|
||
|
|
Anesth Analg 2003;97:650-653 © 2003 International Anesthesia Research Society
|
|||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
hsan Ayik, MD*
lu, MD
 |
Abstract |
|---|
 Top Abstract IntroductionCase ReportDiscussionReferences |
|---|
We describe a 45-yr-old woman with an intermediate type atrioventricular septal defect associated with a double-orifice left atrioventricular valve (DOLAV). We diagnosed this exceptional anomaly by intraoperative transesophageal echocardiography (TEE) during surgery that was scheduled for only a primum type atrial septal defect (ASD) repair. Preoperative transthoracic echocardiography and angiography revealed the ASD but could not demonstrate the DOLAV. We were able to repair this rare and challenging abnormality successfully under the guidance of TEE imaging during the operation. TEE provides valuable information about both anatomy and functional aspect of the valvular structures. Besides its proven role in cardiac surgery, intraoperative use of TEE also serves as a useful tool for diagnosis of such unexpected and potentially missed abnormalities.
Intraoperative transesophageal echocardiography facilitated diagnosis of a double-orifice left atrioventricular valve that was undetected by preoperative transthoracic echocardiography and angiography before repair of an atrial septal defect.
|
Introduction |
|---|
|
TopAbstractIntroductionCase ReportDiscussionReferences |
|---|
Double-orifice left atrioventricular valve (DOLAV) is a rare congenital malformation characterized by the presence of two orifices in the left ventricular valve area, each having an independent chordal attachment to papillary muscle. This exceptional and rare anomaly is usually discovered at autopsy or at surgical procedures for accompanying anomalies incidentally (1–3). In our case, DOLAV was associated with both an intermediate type atrioventricular septal defect and a ventricular septal defect (VSD), and it was not detected with either perioperative transthoracic echocardiography (TTE) or angiography. Intraoperative transesophageal echocardiography (TEE) facilitated incidental diagnosis of DOLAV and was valuable in guiding decisions about intraoperative management.
|
Case Report |
|---|
|
TopAbstractIntroductionCase ReportDiscussionReferences |
|---|
A 45-yr-old woman was admitted to our hospital complaining of retrosternal pain with exertion for 4–5 yr. Physical examination revealed a normotensive woman in no distress with a heart rate of 80 bpm. On auscultation, a 2/6 systolic murmur was noted at the pulmonic area and radiated to other parts of the chest. Further examination was unremarkable, and she was considered as New York Heart Association functional class II. Chest radiography revealed an increased heart-size, including left atrium and atrial appendage. The electrocardiogram showed first-degree atrioventricular block and right bundle branch block. TTE had shown a cleft mitral valve and a large atrial septal defect (ASD), yielding a preoperative diagnosis of a partial type atrioventricular septal defect (Primum type ASD). Ventriculography revealed a valvular structure with a gooseneck appearance and demonstrated movement of contrast medium from the left atrium to the right atrium then to the right ventricle, consistent with the presence of primum ASD. Table 1 presents the oxygen saturation and pressure measurements obtained during cardiac catheterization. Based on these findings, an open cardiac surgical repair of the primum ASD was planned.
|
After general anesthesia was established with fentanyl, midazolam, and pancuronium, TEE was performed (Hewlett Packard Sonos 1000, Palo Alto, CA). During the examination with TEE, we diagnosed abnormally configured chordae tendineae of the left atrioventricular valve including the two inlets to the left ventricle and (1–2/4 degree) mitral regurgitation (Fig. 1). The surgical team was informed of the findings and likelihood of a DOLAV.
|
Standard aorta-bicaval cannulation was accomplished, and cardiopulmonary bypass was instituted with 2.4 L · min-1 · m2 of flow. The perfusate was cooled to 28°C. After the aorta was cross-clamped, cardiac arrest was achieved with cold crystalloid St. Thomas 2 solution and maintained with intermittent cold blood cardioplegia and topical hypothermia. When the surgeons opened the right atrium, a large (4 x 5.5 cm) defect in the inferior (posterior) portion of atrial septum just above the atrioventricular valves and a small defect (1 x 1 cm) in the inflow portion of ventricular septum just below the atrioventricular valves were seen. A large ovoid shaped annular structure in communication with both ventricles was observed (Fig. 2). This annular structure had two atrioventricular orifices on the left side, supported three papillary muscles inside the left ventricle, and one ventricular orifice on the right side was supported by three papillary muscles inside the right ventricle. There were five leaflets: a superior bridging leaflet, an inferior bridging leaflet, a left mural leaflet, a right mural leaflet, and an antero-superior leaflet. These five leaflets were arranged as a quadrifoliate right atrioventricular valve and trifoliate left atrioventricular valve. A fibrous tongue tissue, which was supported by ventricular septum, was connecting the inferior and superior bridging leaflets and separated atrioventricular valve into right and left atrioventricular orifices. Another fibrous tongue tissue, which was supported by chorda and accessory papillary muscle, connected the left mural and inferior bridging leaflets and divided the left atrioventricular orifice into 2 almost equal anteromedial (3 x 2 cm) and posterolateral (2.5 x 2 cm) orifices (Fig. 2). This cardiac malformation was evaluated as intermediate-transitional type atrioventricular septal defect (atrioventricular canal defect) with a DOLAV. The antero-medial orifice showed mild regurgitation between superior and inferior leaflets.
|
The surgical procedure was planned according to the findings of TEE that showed two well-developed orifices at the left atrioventricular valve, normal pliability and motion of leaflets, and no stenosis at the level of left atrioventricular valve. Regurgitation 1–2/4 degrees was observed because of asynchronous closing of leaflets at the level of septal commissure (cleft mitrale), which was formed by fusion of inferior and superior bridging leaflets. The septal commissure was not supported by subvalvular apparatus (chorda or papillary muscle) and for this reason was not a true commissure.
The ASD was closed with a 4 x 6 cm Gore-Tex® (W.L. Gore and Associates, Newark, DE) patch, leaving the left atrioventricular valve and coronary sinus on the left atrial side. Primer sutures supported by Teflon were used for VSD repair. The septal commissure was partially repaired with a single suture that established the synchronous closing of leaflets and a competent atrioventricular valve. To determine the efficacy of surgical repair of ASD, VSD, and DOLAV and possible residual shunting, a confirmatory TEE was performed during the warming period and compared with previous recordings. There was no residual shunting and no gradient or regurgitation at the level of left atrioventricular valve area.
The patient was taken from the operating room with sinus rhythm. She had a smooth recovery and was discharged from the hospital on the seventh postoperative day with antibiotic prophylaxis for infective endocarditis. We examined angiography records retrospectively, and even in this reevaluation, the presence of DOLAV could not be demonstrated. Preoperative TTE was not recorded, so retrospective evaluation was not possible.
During her first and second follow-up visits (postoperative second and sixth month, respectively), the patient was evaluated with both TEE and TTE, and no regurgitation or stenosis were observed at the level of left atrioventricular valve.
|
Discussion |
|---|
|
TopAbstractIntroductionCase ReportDiscussionReferences |
|---|
Incidental diagnosis of this rare anomaly by intraoperative TEE has not been reported. Although in limited cases, it had been possible to diagnose this anomaly preoperatively by TEE or TTE or by cardiac angiography (4–7), most reported DOLAV cases were generally found during cardiac surgery or at autopsy. This typically incidental finding suggests that this anomaly usually remains clinically silent or the preoperative evaluation is insufficient.
The state of the art for preoperative evaluation of atrioventricular septal defect involves careful evaluation of the mitral valve anatomy. Precise evaluation of mitral valve diseases requires adequate visualization of all associated structures including the annulus, leaflets, chordae tendineae, papillary muscles, left atrium, and left ventricular free wall. Echocardiography is the method of choice for analysis of valve diseases; however, detailed anatomic analysis of the mitral valve is not always possible with transthoracic images. There is always a possibility of encountering unexpected and undiagnosed pathologies during surgical procedures. Even during open-heart surgery, DOLAV can remain unrecognized (8).
The use of TEE during surgery became very popular in recent years. Previous studies have documented well that intraoperative TEE provides additional information about cardiac pathology in a significant number of patients (12.8%–38.6%) (9).
Atrioventricular septal defects are characterized by varying degrees of incomplete development of the septal tissue surrounding the atrioventricular valves along with varying degrees of abnormalities of the atrioventricular valves structures. Debate in the literature continues concerning whether to name the left atrioventricular valve in this lesion as mitral valve or just left atrioventricular valve. Another debate is whether to identify the cleft as "cleft" or as "commissure" (10). There is some difficulty in naming the defect as commissure because no annulus is present at that area, and it is not supported by chordae. Strong arguments have been made that left atrioventricular valve and septal commissure are better terms (10). In nomenclature for basic atrioventricular septal defect treatment options, there is frequently use of the phrase "...with/without cleft mitral valve repair." In our case, besides the left atrioventricular abnormality arising from an atrioventricular septal defect, there was an additional intrinsic anomaly of the valve itself, justifying use of the term DOLAV.
More than 200 cases of DOLAV have been reported. The anomaly has also been called various names, such as double mitral valve orifice, dual orifice mitral valve, double-orifice mitral valve, double parachute mitral valve, duplicated mitral valve, or double mitral valve. This anomaly is characterized by the division of the atrioventricular valve in two functioning units opening into the left ventricle. Unlike the fenestrations in the valve, the valve leaflet of the two orifices is supported by chordae tendinea arising from papillary muscles or atrioventricular wall. Various classifications for DOLAV have been proposed based on the size and location of the two orifices (1,7). In the case presented here, the orifices were separated with a fibromuscular tongue tissue into almost equal sizes and were located anteromedially and posterolaterally. The embryologic basis of DOLAV is not yet well understood; however, it is thought to be a result of abnormal fusion of endocardial cushions and abnormal development of the left atrioventricular valve from the primary fold and primitive left ventricle during a delaminating process.
Although isolated cases have been reported, most cases of this rare anomaly are associated with other congenital malformations, mainly with ASD, VSD, or coarctation of aorta (11,12). Depending on reports, DOLAV is found in 3%–10% of all cases of persistent atrioventricular canal (11–13).
The hemodynamic effects of this malformation are variable. Functioning of the valves is usually normal; however, it may cause significant stenosis (6) or regurgitation (2,14). The intraoperative anesthetic management of DOLAV is primarily based on the physiologic status of the valve, whether it is normal, stenotic, or regurgitant. Basic considerations (response to volume loading, control of heart rate, and adjustment of preload and afterload) of exclusive mitral regurgitation and stenosis are also valid for DOLAV. The accompanying pathologies, if any, should also be considered in anesthetic management.
Antibiotic prophylaxis is usually indicated in patients with valvular heart diseases, but because of the rarity of DOLAV, there is insufficient experience and consensus about this issue. We consider that patients with apparent regurgitation or stenosis are at increased risk for infective endocarditis. However, if an isolated, asymptomatic DOLAV is diagnosed during a routine examination and to remain uncorrected, then antibiotic prophylaxis is probably unnecessary, although periodic observation is advisable because of the risk of deterioration of the functioning valve.
According to the severity of lesions and the clinical status, treatment of DOLAV includes leaving the valve uncorrected, surgical valvular repair, or valve replacement (14–17). Surgical procedures for the DOLAV should be individualized with careful intraoperative evaluation of the structure and function of this abnormal valve. The noncleft orifice of a double-orifice mitral valve usually is competent; however, if one orifice is incompetent, surgical correction may be considered. If the valve is regurgitant because of cleft leaflet, the cleft may be sutured, but it should be recognized that total closure of the cleft and the accessory orifice can result in acute iatrogenic mitral stenosis (11), so partial closure may be a better approach. If the valve is severely damaged, valve replacement should be considered (2,17). When the mitral valve cleft is left intact, there is always a probability of progression of important mitral regurgitation leading to reoperation (18). In the case presented here, the orifices were almost equal in size; therefore, the surgical team decided to partially close the cleft with a single suture to avoid possible progression of regurgitation and to minimize the risk of acute iatrogenic stenosis. We were able to successfully repair this rare and challenging abnormality with the help of TEE imaging during operation. Intraoperative TEE determination of exact leaflet anatomy and the mechanism of valve dysfunction has been a key factor in predicting successful surgical repair. TEE features of interest include the presence and degree of calcification or fibrosis, adequacy and mobility of individual leaflets, site and direction of the regurgitant jet, and presence of leaflet clefts and papillary muscle anomalies.
Notwithstanding its infrequency, the potential presence of a DOLAV should be recognized, especially in patients with atrioventricular septal defects, where its diagnosis may occur during surgery and surgical management modified accordingly. This case supports the concept that routine use of TEE is valuable to guide intraoperative management during cardiac surgery, especially for congenital abnormalities.
|
References |
|---|
|
TopAbstractIntroductionCase ReportDiscussionReferences |
|---|
- Bano-Rodrigo A, Van Praagh S, Trowitzsch E, Van Praagh R. Double orifice mitral valve: a study of 27 postmortem-cases with developmental, diagnostic and surgical correction. Am J Cardiol 1988; 61: 152–60.[Web of Science][Medline]
- Kron J, Standerfer RJ, Starr A. Severe mitral regurgitation in a woman with double orifice mitral valve. Br Heart J 1986; 55: 109–11.
[Abstract/Free Full Text] - Reed GE, Cortes LE, Claus RH, Peppert EH. The surgical repair of duplication of mitral orifice. Ann Thorac Surg 1970; 9: 81–5.[Medline]
- Hoffman P, Stumper O, Groundstroem K, Sutherland G. The transesophageal echocardiographic features of double-orifice left atrioventricular valve. J Am Soc Echocardiogr 1993; 6: 94–100.[Medline]
- Purnode P, Rombaut E, Gerard M, et al. Double orifice mitral valve with flail leaflet: a transesophageal echocardiographic examination. Eur J Echocardiogr 2000; 1: 144–6.
[Abstract/Free Full Text] - Yesilbursa D, Miller A, Nanda NC, et al. Echocardiographic diagnosis of a stenotic double orifice parachute mitral valve with a single papillary muscle. Echocardiography 2000; 17: 349–52.[Web of Science][Medline]
- Trowitzsch E, Bano-Rodrigo A, Burger BM, et al. Two-dimensional echocardiographic findings in double orifice mitral valve. J Am Coll Cardiol 1985; 6: 383–7.[Abstract]
- Linka AZ, Renata F, Jost CA. Double orifice mitral valve: images in cardiology. Heart 2000; 84: 244.
[Free Full Text] - Thys DM. Echocardiography and anesthesiology successes and challenges. Anesthesiology 2001; 95: 1313–4.[Web of Science][Medline]
- Jacops JP, Burke RP, Quintessenza JA, Mavrouidis C. Congenital heart surgery nomenclature and database project: atrioventricular canal defect. Ann Thorac Surg 2000; 69: 36–43.
- Warnes C, Somerville J. Double mitral valve orifice in atrioventricular defects. Br Heart J 1983; 49: 59–64.
[Abstract/Free Full Text] - Wakai CS, Edwards JE. Pathologic study of persistent common atrioventricular canal. Am Heart J 1958; 56: 779–94.
- Ilbawi MN, Idriss FS, DeLeon SY, et al. Unusual mitral valve abnormalities complicating surgical repair of endocardial cushion defects. J Thorac Cardiovasc Surg 1983; 85: 697–704.[Abstract]
- Matsuwaka R, Sasakibara T, Mitsuno M, et al. Valve repair for mitral regurgitation associated with isolated double orifice mitral valve. J Thorac Cardiovasc Surg 1996; 112: 1666–7.
[Free Full Text] - Majid AA. Double orifice mitral valve: a case report and review of management. J Cardiovasc Surg (Torino) 1991; 32: 837–9.[Medline]
- Reed GE, Cortes LE, Claus RH, Peppert EH. The surgical repair of duplication of mitral orifice. Ann Thorac Surg 1970; 9: 81–5.
- Yurdakul Y, Arsan S, Karapinar K, et al. Congenital double-orifice mitral valve. Turk J Pediatr 1995; 37: 173–6.[Web of Science][Medline]
- Abbruzzese PA, Livermore J, Sunderland CO. Mitral repair in complete atrioventricular canal. J Thorac Cardiovasc Surg 1983; 85: 388–95.[Abstract]
| ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
