Accessory mitral valve tissue associated with situs inversus in an elderly patient

We report an unusual case of accessory mitral valve tissue associated with a situs inversus and missing obstruction of the left ventricular outflow tract. To our knowledge our patient is the only elderly patient with an accessory mitral valve with associated situs inversus undergoing surgical resection. The report emphasizes direct cardioscopy through the aortic annulus allowing precise excision of the abnormal tissue.     

Accessory Mitral Valve Tissue: A Case Report and an Updated Review of Literature

Abstract Accessory mitral valve tissue is an unusual congenital cardiac anomaly and a rare cause responsible for left ventricular outflow tract obstruction. An 18‐year‐old patient was referred to this hospital due to an occasionally noted heart murmur in a medical examination. Echocardiography facilitated the diagnosis of accessory mitral valve tissue. To relieve the left ventricular outflow tract obstruction, an operation including resection of the accessory mitral valve tissue, implantation of artificial chordae tendineae, and mitral valve annuloplasty was performed successfully. Postoperative echocardiography showed a complete relief of the mitral valve leaflets and a wide patent left ventricular outflow tract. However, transient ischemic attack and Horner's syndrome complicated the patient early postoperatively. He was administered with a high dose of aspirin, and he recovered shortly. Surgical removal is mandatory insomuch as a definite diagnosis of accessory mitral valve tissue with left ventricular outflow tract obstruction is established. A prophylactic treatment should be applied to the patients with accessory mitral valve tissue in virtue of their susceptibility to neurological events.     

Accessory mitral tissue - an unusual cause of left ventricular outflow tract obstruction

Accessory mitral valve tissue is one of the rare anomalies of embryonic development of the endocardial cushion. We describe here a case of a 9?year old male who presented with dyspnoea on exertion. Transthoracic and transesophageal echocardiography revealed aneurysm of membranous part of the interventricular septum producing left ventricular outflow obstruction. Left ventriculography showed a filling defect in the area of mitral aortic interventricular fibrosa probably a localized subaortic membrane. But intraopertive findings showed an accessory mitral valve tissue attached to the annulus of anterior leaflet with its chordal attachment to the papillary muscles of normal mitral valve and to the interventricular septum. The anomalous tissue was excised with its attachment through the aortotomy and left atriotomy. We emphasize, that fixed type of left ventricular outflow tract obstruction produced by an accessory mitral tissue can mimic an aneurysm of the interventricular septum on echocardiography and surgical excision through bicameral approach is recommended.     

Obstruction of left ventricular outflow tract after mechanical mitral valve replacement

We successfully operated on a patient with a rare complication of left ventricular outflow tract obstruction after mitral valve replacement. In a 57-year-old woman with previous mitral valve replacement, transthoracic echocardiography showed left ventricular outflow tract obstruction as a result of anterior displacement of the mitral prosthesis and local thickening of the interventricular septum. Cardiac surgery verified this rare lesion. During the operation, the anterior half of the prosthesis ring was cut away from hyperplastic tissue and sutured to the natural mitral annulus. Subaortic hyperplastic tissue was excised to enlarge the left ventricular outflow tract. The patient had an uneventful postoperative recovery, and left ventricular outflow tract obstruction disappeared on postoperative transthoracic echocardiography.     

Asymptomatic and isolated accessory mitral valve tissue in an adult

Accessory mitral valve (AMV) tissue is a congenital anomaly that occurs in association with other congenital anomalies, and is an uncommon cause of left ventricular outflow tract obstruction. It is usually detected in early childhood when accompanied by symptoms of obstruction of the left ventricular outflow tract, and is rarely diagnosed in adults. We present a case of a 53-year-old man who was referred to our institution for evaluation of a systolic heart murmur. Echocardiography disclosed a diagnosis of AMV tissue. This case was uncommon because of the lack of severe obstruction of left ventricular outflow, cardiac symptoms, or other cardiac anomalies. We were able to carry out surgical resection of AMV tissue to avert possible progression of aortic insufficiency and the risk of a cerebrovascular embolization. The patient’s postoperative course was uneventful, and postoperative echocardiography showed no residual accessory mitral tissue.     

Accessory mitral valve causing left ventricular outflow tract obstruction in an adult

Accessory mitral valve (AMV) is a rare congenital abnormality that, rarely, causes left ventricular outflow tract (LVOT) obstruction in adults. We report the case of a 47-year-old man with deteriorating exertional dizziness. Evaluations revealed that the left ventricular outflow tract obstruction was caused by the accessory mitral valve. The patient underwent a successful operation for removal of the accessory mitral valve.     

Left Ventricular Outflow Tract Obstruction After Mitral Valve Replacement

We describe a patient with left ventricular outflow tract obstruction after mitral valve replacement preserving the anterior subvalvular apparatus. Postoperative transesophageal echocardiography demonstrated systolic narrowing of the left ventricular outflow tract by a bulging septum and systolic anterior motion of the preserved anterior mitral leaflet. Septal myectomy and transaortic mitral apparatus resection enabled us to relieve the left ventricular outflow tract obstruction. This suggests that septal hypertrophy might be a relative contraindication to the preservation of the anterior mitral subvalvular apparatus in mitral replacement.     

Accessory mitral valve leaflet in an adult with coronary artery disease

Accessory mitral valve leaflet is a very rare cause of left ventricular outflow tract obstruction. We report a patient presenting this cardiac abnormality who undergone cardiac surgery. A 60-year-old man, presented coronary artery disease and moderate left ventricular tract obstruction due to accessory mitral valve leaflet. The accessory mitral valve leaflet had the typical morphology of a parachute-shaped attached partially to the anterior mitral valve leaflet, with chordae tendinae attached to: 1) an accessory papillary muscle inserted at the free-wall closed to the apex; 2) interconnected with the chordae tendinae of the anterior mitral valve leaflet; 3) a second accessory papillary muscle inserted to the interventricular septum. He underwent successful coronary revascularization of 2 vessels and accessory leaflet excision. A review of 21 cases with accessory mitral valve leaflet is reported.     

Nonobstructing Accessory Mitral Valve Tissue and Ventricular Septal Defect

A 4-month-old boy with ventricular septal defect was found to have accessory mitral valve tissue attached to the anterior leaflet of the mitral valve. Operation was successfully performed to excise the accessory mitral tissue in the left ventricular outflow tract and close the ventricular septal defect. Most previously reported cases with accessory mitral valve tissue were associated with left ventricular outflow tract obstruction. This boy had no pressure gradient across the left ventricular outflow tract. The indications for prophylactic excision of nonobstructing accessory mitral valve tissue in a patient with other forms of congenital cardiac disease are discussed.     

Septal ablation acutely reduces outflow obstruction after transcatheter mitral valve replacement

Transcatheter mitral valve replacement (TMVR) is an emerging treatment of mitral valve pathology in patients that are not candidates for conventional surgical approaches. Higher rates of left ventricular outflow tract obstruction (LVOTO) may occur following TMVR and its occurrence is an independent predictor of mortality. We present a case of severe mitral stenosis and annular calcification that was treated with a balloon‐expandable Sapien S3 valve in the mitral position delivered through surgical port‐access approach, which resulted in postoperative LVOTO. The LVOTO was successfully treated with alcohol septal ablation with immediate reduction in outflow tract gradients and long‐term resolution.     

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

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

Successful surgical treatment of subaortic stenosis caused by an accessory mitral valve

A 22-month-old boy with subaortic stenosis was found to have relatively mature mitral valve tissue beneath the aortic valve, associated with a hypertrophic and prominent interventricular septum. This tissue caused obstruction of the left ventricular outflow tract and resulted in a pressure gradient of 70 mmHg between the aorta and the left ventricle. Surgical treatment was successfully performed to excise the tissue and part of the hypertrophic ventricular septum. Results of microscopic examination of the resected specimen are shown and discussed.     

3-dimensional printing for the diagnosis of left ventricular outflow tract obstruction after mitral valve replacement

The objective of this study was to evaluate the use of the generation of 3D models and 3D prints of complex cases for physicians at the example of an intricate left ventricular outflow tract obstruction (LVOTO). LVOTO is a known complication of mitral valve surgery. A 38-year-old female patient with increasing dyspnoea after mitral valve replacement was referred to our centre. Echocardiography showed a strut of the bioprosthetic heart valve protruding into the left ventricular outflow tract. However, the diagnosis of a LVOTO was difficult based on echocardiography alone. Therefore, we fabricated a physical model of the left ventricular outflow tract, the mitral valve, the aortic valve and the left ventricle. With this physical model in hand, we were able to visualize the LVOTO and to discuss potential therapeutic options. Moreover, we were able to plan the subsequent redo surgery in detail using the model. This case shows the benefit of 3D printing technologies for surgeons and patients, not only for analysis, but also during the decision-making and pre-operative planning process.     

Surgical management of the straddling mitral valve in the biventricular heart

BACKGROUND: The straddling mitral valve in the biventricular heart is a rare condition that may complicate biventricular repair. METHODS: Treatment and outcomes in 5 consecutive patients who underwent primary repair between 1992 and 1997 were reviewed. Their ages at repair ranged from 2 months to 8 years. Three patients had a double-outlet right ventricle with a subaortic (n = 2) or subpulmonary (n = 1) ventricular septal defect. Two patients had transposition of the great arteries (S,D,D), a ventricular septal defect, and left ventricular outflow tract obstruction. The attachments of the papillary muscles of the straddling mitral valves were located on the right ventricular aspect of the ventricular septum. Four patients underwent baffle partitioning of the ventricular cavity. The baffle suture line was used to secure the chordae tendineae crossing the ventricular septal defect, or was intentionally omitted at the papillary muscle. The right ventricular outflow tract was reconstructed with patch augmentation, an extracardiac conduit, or an arterial switch operation. One patient with transposition who had a giant papillary muscle to the straddling mitral valve associated with abnormal insertion of the tricuspid valve on the conal septum underwent univentricular repair. RESULTS: There were no early or late postoperative deaths. There was no mitral valve dysfunction, left ventricular outflow tract obstruction, or heart block in the 4 patients who underwent biventricular repair. CONCLUSIONS: Although there are several exceptional situations in which ventricular partitioning may result in early and late complications, a straddling mitral valve does not preclude biventricular repair.     

Use of the Alfieri edge-to-edge technique to eliminate left ventricular outflow tract obstruction caused by mitral systolic anterior motion

A 68-year-old woman with concentric left ventricular hypertrophy, prosthetic valve endocarditis with aortic root abscess, and sepsis had aortic root replacement with an aortic allograft. On weaning from cardiopulmonary bypass, she had hemodynamic instability caused by systolic anterior motion of the mitral valve, which resulted in a left ventricular outflow tract obstruction; the peak pressure gradient across the left ventricular outflow tract was 130 mm Hg, and there was moderately severe (3+) mitral regurgitation. After reinstitution of cardiopulmonary bypass, a central Alfieri edge-to-edge stitch was placed between the anterior and posterior leaflets of the mitral valve. This reduced the gradient across the left ventricular outflow tract to 10 mm Hg and eliminated the mitral regurgitation, which enabled successful separation from cardiopulmonary bypass.     

Modified Konno procedure for a child with left ventricular outflow tract obstruction after repair of atrioventricular septal defect: a transaortic transpulmonary approach

A one-year-old infant underwent repair of atrioventricular septal defect with common orifice. About 2 years later, echocardiography revealed a left ventricular outflow tract obstruction for the first time. Because of progression of the obstructive lesion, a modified Konno procedure through a transaortic transpulmonary approach was later performed at 8 years old, and the postoperative course was uneventful. This is a useful procedure for left ventricular outflow tract obstruction with normal aortic valve and aortic annulus, because it can both preserve a native aortic valve and dose not necessitate right ventriculotomy in resection of hypertrophied muscle and patch enlargement of interventricular septum.     

Isolated accessory mitral valve tissue in an asymptomatic elderly patient

Accessory mitral valve tissue is a membranous or tumor-like structure observed in the left ventricular outflow tract. This congenital anomaly has been reported in more than 100 cases since 1842; however, most of them were found in patients with complex cardiac malformations. We report a 72-year-old Asian woman with isolated accessory mitral valve tissue incidentally found during the evaluation of hypertension and arrhythmia. Her left ventricular outflow tract obstruction was mild. Because worsening of the left ventricular outflow tract obstruction was reported in patients without significant obstruction at the time of diagnosis, periodical echocardiographic follow-up is necessary.     

Left ventricular outflow enlargement by the Konno procedure

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

Pseudoaneurysm in the mitral-aortic intervalvular fibrosa. A cause of mitral regurgitation

Left ventricular outflow tract pseudoaneurysm is an uncommon but potentially catastrophic complication of aortic valve surgery, aortic valve endocarditis or chest trauma. We describe a case of a left ventricular outflow tract pseudoaneurysm 1 month after an aortic valve replacement that caused a systolic compression of mitral valve and a severe regurgitation. The diagnosis was confirmed using transoesophageal echocardiography, magnetic resonance image and intraoperative endoscopy. Surgical repair of the pseudoaneurysm corrected the mitral regurgitation.     

Dynamic left ventricular outflow tract obstruction when the anterior leaflet is retained at prosthetic mitral valve replacement

Dynamic left ventricular outflow tract obstruction developed in a patient in whom the anterior leaflet was retained at mitral valve replacement. It was caused by systolic anterior movement of the native anterior leaflet. Reduced outflow tract diameter, resulting from both posterior displacement of the septum and anterior displacement of the native anterior leaflet by porcine stents, was likely instrumental in promoting dynamic obstruction.