Reconstruction of a friable posterior mitral annulus after removing a calcified artificial ring using flipover technique of the anterior mitral leaflet

We report a new technique for reinforcement of a friable posterior mitral annulus using the anterior leaflet after removing a calcified artificial ring. A 72-year-old woman underwent mitral valve replacement for mitral stenosis and recurrence of regurgitation after mitral valve repair at 53 years of age. She had been on chronic hemodialysis for 20 years. The posterior mitral annulus became highly friable after débridement of the calcified artificial ring. The anterior mitral leaflet was detached from its annulus and transferred to the posterior annulus to cover the defect. The anterior leaflet was anchored to the posterior annulus by valve sutures, and mitral valve replacement was performed successfully. Postoperative ultrasonic cardiography revealed preservation of left ventricular function with no perivalvular leakage.     

Left ventricular rupture following mitral valve replacement due to oversize prosthesis

Left ventricular rupture following mitral valve replacement is one of the most serious complications. We report our experience in successful treatment of type III left ventricular rupture following mitral valve replacement probably due to an oversize prosthesis. A 67-year-old woman, with the history of percutaneous transluminal mitral commissurotomy 11 years previously, underwent mitral valve replacement for mitral restenosis with a 27 mm CarboMedics mechanical bileaflet valve (Sulzer CarboMedics Inc., Austin, TX, U.S.A.). There were some difficulties in placing the entire prosthesis into the annulus at the posterior because of the oversize prosthesis. After the complete placement of the prosthesis, bulge of the left ventricular muscle was evident around the left lateral region. Following the cessation of cardio-pulmonary bypass, type III left ventricular rupture, half a circular rip between the papillary muscles and posterior mitral annulus, occurred. The rip was suture-closed and a 23 mm CarboMedics valve was placed. Postoperative ultrasonic cardiography showed no prosthetic stenosis, periprosthetic leak, left ventricular pseudoaneurysm, nor left ventricular asynergy. Under cardioplegic arrest, we should not select the oversize prosthesis to prevent left ventricular rupture.     

Redo mitral valve repair with complete ring implantation over an open band

We present a case of redo mitral valve surgery after failed repair that consisted of implantation of a complete ring over an open band implanted several years prior. The patient presented with severe central mitral regurgitation. During surgical intervention, the open band was identified consolidated with the native annulus. We elected not to remove the posterior annulus given the presence of calcification. Instead, a new complete ring was secured with single sutures posteriorly over the band and anterior to the native annulus. This approach was safe, fast, and achieved a significant reduction in annulus circumference with no residual mitral regurgitation.     

Mitral valve replacement with posterior transposition of the anterior mitral leaflet which covers and buttresses partially decalcified posterior mitral annular bed

Mitral valve replacement (MVR) in the presence of the extensive calcification of the mitral annulus is a technical challenge. The heavily calcified annulus can cause great difficulty in the insertion of a prosthetic valve and periprosthetic leakage later on. Vigorous annular decalcification may cause circumflex coronary artery injury, atrioventricular rupture and thromboembolic events. We herein describe a surgical technique for MVR in such cases while focusing on partial decalcification of the posterior mitral annulus and its reinforcement and buttressing with the transferred anterior mitral leaflet (AML). At the same time, the transferred AML supports the posterior annular region and maintains ventricular-annular continuity, thus preserving the left ventricular function.     

An in vitro investigation into the hemodynamic effects of orifice geometry and position on left ventricular vortex formation and turbulence intensity

In a healthy human cardiac system, a large asymmetric clockwise vortex present in the left ventricle (LV) efficiently diverts the filling jet from the mitral annulus to the left ventricular outflow track. However, prior clinical studies have shown that artificial mitral valve replacement can affect the formation of physiological vortex, resulting in overall flow instability in the LV. Lately, the findings from several recent hemodynamic studies seem to suggest that the native D-shaped mitral annulus might be a crucial factor in the development of this physiological flow pattern, with its inherent flow stability and formation of coherent structures within the LV. This study aims to investigate the effect of orifice shape and its position with respect to the posterior wall of the ventricle on vortical formation and turbulence intensity in the LV, by utilizing four separate orifice configurations within an in vitro left heart simulator. Stereo particle image velocimetry experiments were then carried out to characterize the downstream flow field of each configuration. Our findings demonstrate that the generation of the physiological left ventricular vortical flow was not solely dependent upon the orifice shape but rather the subsequent jet-wall interaction. The distance of the orifice geometric center from the left ventricular posterior wall plays a significant role in this jet-wall interaction, and thus, vortical flow dynamics.     

Use of the anterior mitral leaflet to reinforce the posterior mitral annulus after debridement of calcium.

In mitral valve surgery, preservation of continuity between the papillary muscles, chordae, and annulus is associated with preservation of left ventricular function and reduced risk of postoperative left ventricular rupture. However, at mitral valve replacement, extensive annulus and leaflet calcification can necessitate resection of the posterior mitral leaflet. We describe a technique in which the anterior mitral leaflet and its subvalvular apparatus are used to reinforce the posterior mitral annulus after extensive debridement of calcium along the same annulus.     

Mitral annular calcification and the serum osteocalcin level in patients with chronic kidney disease

Objective: To determine the relationships between inflammatory mediators, mitral annular calcification (MAC), and osteocalcin in patients with chronic kidney disease (CKD). Materials and methods: Echocardiographic data for 60 patients diagnosed as CKD were retrospectively evaluated. The patients were divided into 2 groups; patients with MAC (MAC+ group) and patients without MAC (MAC? group). The relationships between biochemical markers—including osteocalcin—and MAC were evaluated. Results: The study included 19 female and 41 male patients. In all, 29 patients were MAC+ and 31 were MAC?. High-sensitive C-reactive protein (hsCRP) and osteocalcin levels were significantly higher in the MAC+ group (p?0.05). The eGFR was lower, serum calcitonin (we could not obtain calcitonin data for 15 patients), Ca, PO4, CaxPO4, the erythrocyte sedimentation rate, red cell distribution width, the neutrophil/Lymphocyte rate, and PTH were higher in the MAC+ group; however, the differences between the groups were not significant (p?>?0.05). The mitral E/A ratio, mitral peak Ea velocity, tricuspid E/A ratio, hsCRP, and the osteocalcin level were strongly correlated with MAC. Multivariate logistic regression analysis showed that only the osteocalcin level and mitral E/A ratio were independent variables, each with an independent effect on MAC. Conclusion: CKD patients in the MAC+ group had higher osteocalcin levels than those in the MAC? group, and left ventricular diastolic dysfunction was more common in the MAC+ group.     

Etiology of left ventricular rupture following mitral valve replacement]

Two uncommon cases of left ventricular rupture that occurred during cardiac surgery were treated successfully. These cases may be useful in understanding the etiology of common left ventricular rupture following mitral valve replacement. One case occurred during coronary bypass surgery. The myocardium which is already abnormal seems to be weak to trauma such as bending, traction and torsion. In the other case, who underwent mitral valve replacement with preservation of the posterior leaflet with its attached chordae, the disruption was localized in the epicardial side of the left ventricular posterior wall, though direct injury by some instrument was excluded as a possibility, with a depth of half the thickness of the wall. In experiments using dogs, shape and movement of the mitral annulus were examined. The length of the annulus attached to the posterior leaflet in end-systole was shortened to 89.0 +/- 4.6% of that in late diastole. Furthermore, the annulus was distorted by the elevation of the heart. We approve of Cobbs' "untethered ventricle theory" and consider moreover as follows: In general, whether with or without preservation of the mitral loop, the mitral annulus and the left ventricular posterior wall after mitral valve replacement are severely constricted by the rigid prosthetic ring and become tense, which limits movement in both circular and longitudinal directions. Then even slight stress may cause a primary tear on the posterior wall of the left ventricle, resulting in rupture. In order to treat the rift, the prosthesis must be removed before the apex of the heart is lifted, to avoid excessive ventricular wall tension.     

Aorto-mitral annular dynamics

BACKGROUND: The aortic and mitral valves are coupled through fibrous aorto-mitral continuity, but their synchronous dynamic physiology has not been completely characterized. METHODS: Seven sheep underwent implantation of five radiopaque markers on the left ventricle, 10 on the mitral annulus, and 3 on the aortic annulus. One of the mitral annulus markers was placed at the center of aorto-mitral continuity (mitral annulus "saddle horn"). Animals were studied with bi-plane videofluoroscopy 7 to 10 days postoperatively. Total circumference and lengths of mitral fibrous annulus, mitral muscular annulus, aortic fibrous annulus, and aortic muscular annulus were calculated throughout the cardiac cycle from three dimensional marker coordinates as was mitral annular area and aortic annular area. Aorto-mitral angle was determined as the angle between the centroid of the aortic annulus markers, the saddle horn, and the centroid of the mitral annulus markers. Aortic annulus and mitral annulus flexion was expressed as the difference between maximum and minimum values of the aortic and mitral annulus angles during the cardiac cycle. RESULTS: Mitral and aortic annular areas changed in roughly a reciprocal fashion during late diastole and early systole with an overall 32 +/- 8% change in aortic annular area and a 13 +/- 13% change in mitral annular area. Aortic fibrous annulus changed much less than aortic muscular annulus (6 +/- 2% vs 18 +/- 4%; p = 0.0003) as did mitral fibrous annulus relative to mitral muscular annulus (4 +/- 1% vs 8 +/- 2%; p = 0.004). Aortic annulus and mitral annulus flexion was 8 +/- 2 degrees and increased to 11 +/- 2 degrees (p = 0.009) with inotropic stimulation. CONCLUSIONS: Dynamic aortic and mitral annular area changes were not mediated through the anatomic fibrous continuity. Aorto-mitral flexion, which increased with enhanced contractility, may facilitate left ventricle ejection. The effect of valvular surgical interventions on aorto-mitral flexion needs further investigation.     

Annular reconstruction for mitral valve replacement in a destroyed or calcified mitral annulus

Mitral valve replacement in the presence of severe annular calcification and an infectious lesion may be complicated by atrioventricular rupture, left circumflex coronary artery injury, and recurrence of infective endocarditis. Confronted with these circumstances, we have developed a technique of annular reconstruction for mitral valve replacement. The prosthetic valve is made by enlarging the circumference of the sewing ring with a Dacron collar. The collar can be sutured to the left atrial wall above the mitral annulus. This technique has been employed in five patients: three had extensive annular calcification, and two had acute valve endocarditis with destruction of mitral annulus. In all cases, the circumferential or partial annular reconstruction permitted secure implantation of the prosthetic valve. The one postoperative death was related to hemodialysis due to chronic renal failure. There were no other fatalities during the postoperative course, and the valves functioned normally. Our results suggest that this technique can be performed in high operative risk patients when mitral valve replacement is impossible using conventional techniques.     

Mitral valve replacement in the presence of massive posterior annular calcification

Replacement of the mitral valve in the presence of extensive calcification of the posterior annulus is a technical challenge. The heavily calcified annulus often results in difficulties of seating the prosthesis and later periprosthetic leakage. A radical calcium debridement may leave a friable and thin annulus that contributes to the risks of prosthesis dehiscence and ventricular perforation. To avoid technical difficulties and associated catastrophic complications, we devised a new technique of mitral valve replacement that allows a surgeon to implant a prosthesis securely. This technique involves inserting a larger single tilting disc mechanical valve (Medtronic Hall disc) with intra-atrial anchorage over the posterior sector of the calcified annulus, orienting the working (major) orifice of the mechanical valve anteriorly, and thereby tilting the lesser occluder segment of the disc upward into the atrium and away from the calcification in diastole. By utilizing this method, we have successfully performed mitral valve replacement in two patients who exhibited massive calcification of the posterior mitral annulus. Postoperative transeosophageal echocardiography showed excellent hemodynamic performance of the implanted valves. We therefore recommend this simple, safe, and time-saving procedure as a feasible method to deal with this surgical dilemma.     

非体外循环下采用自制二尖瓣成形装置手术治疗轻至中度缺血性二尖瓣关闭不全

目的尝试在非体外循环冠状动脉旁路移植术(OPCAB)期间对轻至中度缺血性二尖瓣反流(IMR)患者采用自制二尖瓣成形装置进行外科处理,并评估其疗效。方法回顾性分析自2009年9月至2011年8月北京安贞医院6例轻至中度IMR患者(男4例、女2例,年龄52～73岁)在OPCAB期间采用自制二尖瓣成形装置进行二尖瓣成形的临床资料。在处理IMR前及处理后通过经食管超声心动图测定IMR程度、二尖瓣瓣环前后径、左心室短轴径、左心室长轴径、左心室球形指数(左心室短轴径/左心室长轴径)等;通过Swan-Ganz导管测量并记录主动脉平均压、肺动脉平均压和中心静脉压等。比较围术期相关心功能指标。结果无住院死亡。二尖瓣成形后IMR均消失、二尖瓣瓣环前后径[(3.43±0.08)cm vs.(3.68±0.08)cm;t=5.430,P=0.001]、左心室短轴径[(4.80±0.21)cm vs.(5.53±0.11)cm;t=7.530,P=0.001]和左心室球形指数(0.64±0.02 vs.0.74±0.01;t=11.110,P=0.002)均较处理前明显减小;左心室长轴径无明显变化(P>0.05);术中血流动力学指标无明显变化。术后3个月6例患者(随访率100%)均在门诊复查,均无自主临床症状,心功能均改善至Ⅰ级(NYHA)。超声心动图提示:二尖瓣无反流4例,有微量反流2例。结论在OPCAB期间采用自制二尖瓣成形装置成形治疗IMR,直接完成了左心室塑型,规避了体外循环风险,即刻疗效确切,对循环指标影响甚小,有一定的临床应用价值。     

Successful repair of subvalvular annular aneurysm of the left ventricle

A 62-year-old woman was admitted to our hospital due to congestive heart failure. On the chest X-ray film, cardiomegaly and prominent pulmonary congestion were revealed. She became well with bed rest and medication of digitalis and diuretics. Echocardiogram established the diagnosis of severe mitral regurgitation. In addition, cineangiography of the left ventricule showed cystic left ventricular aneurysm which originated from below the posterior mitral annulus. Operation was performed on July 16, 1990. Under cardiopulmonary bypass, we reflected the apex of the LV upwards, but failed to identify the aneurysm. Then, left atrium was opened through Dubost incision. As regards mitral valve structures, there were no abnormal findings except moderate enlargement of it's orifice. After resection of the mitral valve, orifice of the aneurysm (0.5 X 2.0 cm) was recognized, which was closed with the buttressed sutures. Afterwards, MVR was performed with 25 mm Medtronic Hall valve. The patient had a smooth postoperative course without complication.     

Functional mitral regurgitation in chronic ischemic coronary artery disease: analysis of geometric alterations of mitral apparatus with magnetic resonance imaging

BACKGROUND: Patients with chronic coronary artery disease have double the mortality rate if the condition is combined with functional mitral regurgitation. An understanding based on geometric alterations of the mitral apparatus in functional mitral regurgitation is desirable. METHODS: Twenty-nine subjects were enrolled in the study, including 9 healthy volunteers (control group), 12 patients with chronic coronary artery disease without functional mitral regurgitation (CAD group), and 8 patients with chronic coronary artery disease with functional mitral regurgitation (CAD+FMR group). Cine magnetic resonance imaging was performed to acquire multiple short-axis cine images from base to apex. Left ventricular end-systolic volume, left ventricular ejection fraction, mitral area, and vertices of the mitral tetrahedron, defined by medial and lateral papillary muscle roots and anterior and posterior mitral annulus, were determined from reconstructed images at end-systole. Anterior-posterior annular distance, interpapillary distance, and annular-papillary distance (the distance from the anterior or posterior mitral annulus to the medial or lateral papillary muscle roots) were calculated. RESULTS: Left ventricular end-systolic volume was inversely associated with left ventricular ejection fraction (R(2) = 0.778). Left ventricular end-systolic volume was highly associated with distances related to ventricular geometry (R(2) = 0.742 for interpapillary distance, 0.792 for the distance from the anterior mitral annulus to the medial papillary muscle root, and 0.769 for distance from the anterior mitral annulus to the lateral papillary muscle root) but was moderately associated with distances related to annular geometry (R(2) = 0.458 for anterior-posterior annular distance and 0.594 for mitral area, respectively). Moreover, interpapillary distance of greater than 32 mm and distance from the anterior mitral annulus to the medial papillary muscle root of greater than 64 mm readily distinguished the CAD+FMR group from the other groups. CONCLUSION: In patients with coronary artery disease, an increase in left ventricular end-systolic volume is associated with inadequate approximation of the mitral tetrahedron during systole, which consequently leads to functional mitral regurgitation. Our study suggests that interpapillary distance and distance from the anterior mitral annulus to the medial papillary muscle root are sensitive to the increase in left ventricular end-systolic volume and reliably indicate the presence of functional mitral regurgitation.     

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.     

Mitral valve replacement for extensive calcification: half and half technique

A 50-year-old woman who had been undergoing hemodialysis for 18 years underwent mitral valve replacement because of mitral valve stenosis. Her mitral valve leaflet and annulus were highly calcified, and it was impossible to remove the posterior leaflet from the ventricular wall. At the time of surgery, noneverted horizontal mattress sutures were placed from the left ventricle to the left atrium on the anterior half of the mitral annulus and everted horizontal mattress sutures on the left atrial wall close to the calcified posterior annulus. A 25-mm St. Jude valve was seated successfully at a supra-annular position. The St. Jude valve is suitable for this technique because its leaflets protrude less into the left ventricle.     

Ischemia in three left ventricular regions: Insights into the pathogenesis of acute ischemic mitral regurgitation

BACKGROUND: Acute posterolateral left ventricular ischemia in sheep results in ischemic mitral regurgitation, but the effects of ischemia in other left ventricular regions on ischemic mitral regurgitation is unknown. METHODS: Six adult sheep had radiopaque markers placed on the left ventricle, mitral annulus, and anterior and posterior mitral leaflets at the valve center and near the anterior and posterior commissures. After 6 to 8 days, animals were studied with biplane videofluoroscopy and transesophageal echocardiography before and during sequential balloon occlusion of the left anterior descending, distal left circumflex, and proximal left circumflex coronary arteries. Time of valve closure was defined as the time when the distance between leaflet edge markers reached its minimum plateau, and systolic leaflet edge separation distance was calculated on the basis of left ventricular ejection. RESULTS: Only proximal left circumflex coronary artery occlusion resulted in ischemic mitral regurgitation, which was central and holosystolic. Delayed valve closure (anterior commissure, 58 +/- 29 vs 92 +/- 24 ms; valve center, 52 +/- 26 vs 92 +/- 23 ms; posterior commissure, 60 +/- 30 vs 94 +/- 14 ms; all P <.05) and increased leaflet edge separation distance during ejection (mean increase, 2.2 +/- 1.5 mm, 2.1 +/- 1.9 mm, and 2.1 +/- 1.5 mm at the anterior commissure, valve center, and posterior commissure, respectively; P <.05 for all) was seen during proximal left circumflex coronary artery occlusion but not during left anterior descending or distal left circumflex coronary artery occlusion. Ischemic mitral regurgitation was associated with a 19% +/- 10% increase in mitral annular area, and displacement of both papillary muscle tips away from the septal annulus at end systole. CONCLUSIONS: Acute ischemic mitral regurgitation in sheep occurred only after proximal left circumflex coronary artery occlusion along with delayed valve closure in early systole and increased leaflet edge separation throughout ejection in all 3 leaflet coaptation sites. The degree of left ventricular systolic dysfunction induced did not correlate with ischemic mitral regurgitation, but both altered valvular and subvalvular 3-dimensional geometry were necessary to produce ischemic mitral regurgitation during acute left ventricular ischemia.     

Preservation of All Chordae Tendineae and Papillary Muscle During Mitral Valve Replacement with a Tilting Disc Valve

Mitral valve replacement was performed in 21 patients using a surgical technique that preserves the entire papillary muscle and chordal apparatus. With this technique, the anterior mitral leaflet is split from the center of the free edge toward the annulus. Bilateral incisions are made from the proximal end of this split to the two mitral commissures, detaching the anterior leaflet from the annulus. These two halves of the leaflet, with all chordae intact (corresponding to the anterolateral and posteromedial papillary muscles), are judiciously trimmed to remove areas of leaflet untethered by chordae tendineae and (when necessary) fibrous thickening; then swung posteriorly and sutured to the posterior mitral annulus using mattress sutures with pledgets. This surgical technique is expected to favor the preservation of left ventricular function and avoid occurrence of irreversible left ventricular dilation/dysfunction, and has been used successfully for calcific and degenerative etiologies, using both tilting disc valves and porcine bioprostheses. It is especially useful in the implantation of tilting disc and bileaflet mechanical prostheses because anterior subvalvular chordae tissue may interfere with the disc excursion and relocated to the posterior leaflet annulus.     

Intra-atrial implantation of mitral valve prosthesis in 2 patients with active infective endocarditis complicated by mitral annular destruction]

This is a report of two patients with extensive destruction of the mitral annulus due to active infective endocarditis. Patient 1 was a 66-year-old female and the patient 2 was a 59-year-old male. In both patients medical therapy had failed to control endocarditis and emergency mitral valve replacements were carried out. At the operation special surgical techniques were necessitated, since insertion of artificial valves in the annulus was impossible because of the lack of the annular tissue due to destruction and excision. On the posterior commissure side, mitral valve prosthesis were sutured to the left atrial wall just above the anatomical mitral ring. Furthermore, in patient 2, a bovine pericardium collar attached to the prosthetic valve was sutured to the left atrial wall to secure fixation of the prosthetic valve. The postoperative courses were uneventful in both patients. This technique seems to be useful in patients with mitral annular destruction.