Acute bioprosthetic mitral valve stenosis in a patient with HITS

Acute thrombosis involving the left atrium and a bioprosthetic valve during the early postoperative period is an extremely rare complication of heparin-induced thrombocytopenia syndrome (HITS). We present a patient with early bioprosthetic mitral valve stenosis complicated by HITS in a patient with severe mitral regurgitation, atrial fibrillation, and severe left ventricular dysfunction.     

Left atrial reduction plasty: a novel technique

We describe a novel technique of left atrial volume reduction in a patient presenting with severe dyspnea from severe mitral insufficiency, giant left atrium, and compressive symptoms of dysphagia and dysphonia. Resection involved circumferential excision of the left atrium anterior to the pulmonary venous vestibule and posterior to the mitral valve and fossa ovalis, including the left atrial appendage. A chordal-sparing bioprosthetic mitral valve replacement, tricuspid valve annuloplasty, and coronary bypass were also performed. Significant reduction of left atrial volume by 50% was achieved and clinical resolution of compressive symptoms was seen at 6-month follow-up.     

Acute early failure of a bioprosthesis after mitral valve replacement with completely preserved annuloventricular continuity

We report a case of acute early bioprosthetic failure after mitral valve replacement with completely preserved annuloventricular continuity. A 77-year-old man with left ventricular dysfunction underwent double valve replacement with Carpentier-Edwards pericardial bioprostheses. Routine postoperative echocardiography revealed 1.4 cm² of estimated mitral valve area, and computed tomography revealed a large thrombus in the left atrium. Transesophageal echocardiography showed a restricted opening of the bioprosthetic leaflets. After a month of strict anticoagulation therapy, cusp mobility improved, with a calculated mitral valve area of 3.5 cm²; and the left atrial thrombus had almost disappeared 2 months after initiation of therapeutic anticoagulation. Surgeons should be watchful for bioprosthetic thrombosis in patients with left ventricular dysfunction who undergo mitral valve replacement with a preserved mitral subvalvular apparatus.     

Bioprosthetic mitral valve thrombosis less than one year after replacement and an ablative MAZE procedure: a case report

Occurrence of bioprosthetic valve thrombosis less than a year after replacement is very uncommon. Here, we describe a case of a 57 year old male, who presented 10 months after receiving a bioprosthetic mitral valve replacement with a two week history of dyspnea on exertion, worsening orthopnea and decreased exercise tolerance. Echocardiography revealed severe mitral regurgitation (MR), thrombosis of the posterior mitral leaflet, left atrial (LA) mural thrombus and a depressed left ventricular ejection fraction of twenty-five percent. Given severe clot burden and decompensated heart failure (New York Heart Association - NYHA class III) repeat sternotomy was done to replace the bioprosthetic mitral valve and remove LA mural thrombus. MR was resolved postoperatively. This brief report further reviews promoting factors, established guidelines and management strategies of bioprosthetic valve thrombosis.     

Enlarged coronary sinus thrombosis after repair of Ebstein's anomaly

A 58-year-old woman was referred to our hospital with progressively increasing breathlessness. She reported a history of bioprosthetic valve implantation for tricuspid valve replacement and direct closure of an atrial septal defect for Ebstein's anomaly, 31 years before presentation. Transthoracic echocardiography revealed prosthetic valve failure, an enlarged coronary sinus, and severe mitral regurgitation. Computed tomography revealed a giant coronary sinus with thrombosis and persistent left superior vena cava. She underwent successful mitral and tricuspid valve replacement; however, severe hemodynamic deterioration necessitated mechanical ventilatory support with extracorporeal membrane oxygenation.     

Direct transatrial transcatheter SAPIEN valve implantation through right minithoracotomy in a degenerated mitral bioprosthetic valve

Transcatheter valve implantation into failing surgical mitral bioprosthetic valves have been reported. This strategy avoids performing high-risk repeat cardiac surgery in elderly patients with multiple comorbidities. All these patients have been treated by a transapical approach. We report a case of failing bioprosthetic mitral valve in an 82-year-old woman successfully treated with a 29-mm Edwards SAPIEN balloon expandable bioprosthesis (Edwards Lifesciences, Irvine, CA) with direct left atrial approach through a right anterior thoracotomy. Our experience demonstrates the technical feasibility and safety of this approach. Therefore, mitral valve-in-surgical valve implantation may be a viable treatment alternative in carefully selected patients.     

Left atrial myxoma causing mitral insufficiency. Report of a case treated with mitral valve replacement.

A case of left atrial myxoma causing mitral insufficiency treated with valve replacement and diagnosed preoperatively as mitral stenosis is presented. The presence of mitral regurgitation is very rare in atrial myxomas and requires mitral valve replacement. In our case mitral regurgitaion was due to the mechanical trauma of the valve by the tumor mass because the patient had no history of rheumatic fever and the pathologic examination of the valve displayed neither rheumatic nor myxomatous degeneration.     

胸腔镜下二尖瓣生物瓣置换术32例分析

目的探讨胸腔镜下二尖瓣生物瓣置换的经验,评价其临床效果。方法回顾性分析2013年3～12月在广东省人民医院心血管外科行胸腔镜下二尖瓣生物瓣置换术32例患者的临床资料。其中男14例、女18例,年龄19～80（55.6±17.3）岁,体重37～78（55.7±9.7）kg,体表面积1.30～1.95（1.67±0.16）m^2;合并心房颤动5例,术前心功能分级（NYHA）Ⅱ级20例,Ⅲ级11例,Ⅳ级1例;二尖瓣风湿性病变16例,二尖瓣退行性病变11例,感染性心内膜炎4例,合并先天性心脏病1例。结果所有患者均行胸腔镜下二尖瓣生物瓣置换术,其中采用Medtronic HancockⅡ人工生物瓣27例,Medtronic Mosaic生物瓣5例。同期行三尖瓣成形术13例,房间隔缺损修补术1例。全组患者住院期间无死亡,均顺利出院,住院期间未并发低心排血量综合征及左心室破裂。术后复查心脏彩色超声心动图提示,所有患者人工二尖瓣功能良好,无瓣周漏发生。术后患者心功能较术前明显改善,心功能恢复至Ⅰ级9例,Ⅱ级17例,Ⅲ级6例。术后早期及术后3个月左心房内径及左心室舒张期末内径与术前相比均明显减小。而术后早期及术后3个月左心室射血分数（LVEF）与术前相比有所降低。结论胸腔镜下二尖瓣生物瓣置换术创伤小,并发症少,安全可行,使用特殊类型生物瓣可明显减小手术切口大小。     

Transaortic delivery of the transmitral lesion in a complete maze procedure

A 68-year-old hypertensive diabetic woman with chronic atrial fibrillation presented with progressive congestive symptomatology. She was diagnosed with severe aortic stenosis, moderate mitral regurgitation, and critical right coronary artery stenosis. In addition to coronary revascularization and bioprosthetic aortic valve replacement, she underwent a mitral valve repair and a complete cryoMaze procedure through a transaortic approach. This technique obviates a separate left atriotomy for the mitral repair and Maze procedure. It affords excellent exposure, while reducing cross clamp and cardiopulmonary bypass time as well as avoiding the potential sequelae of bleeding and traction injuries resulting from a left atriotomy.     

Endoventricular pocket repair of type I myocardial rupture after mitral valve replacement: a new technique using pericardial patch, Teflon felt, and BioGlue

Left ventricular (LV) rupture is an infrequent but potentially lethal complication of mitral valve replacement and repair. We report the case of an 82-year-old man who underwent mitral valve replacement and the repair of an atrial septal defect. Both valve leaflets were excised and the annulus was extensively decalcified, followed by the implantation of a bioprosthetic valve. LV rupture was diagnosed after weaning from cardiopulmonary bypass (CPB). CPB was resumed and the bioprosthetic valve was removed. The patient then underwent a unique repair using a pericardial patch, Teflon felt (Meadox Medical Inc, Oakland, NJ), and BioGlue (CryoLife Inc, Kennesaw, GA). A second valve was implanted with a successful outcome.     

A novel technique for giant left atrium reduction.

We herein describe a safe and reproducible technique for left atrial volume reduction in patients with a giant left atrium. In a 56-year-old patient undergoing redo mitral valve replacement, the left atrium measured 18 x 20 x 17 cm occupying the middle-lower segment of the right hemithorax with compression of the adjacent organs. The left atrial volume was reduced by triangular resections of the atrial wall and the mitral valve was replaced using a mechanical prosthesis. The postoperative course was uneventful and the left atrial diameter was 11.2 cm at the latest control.     

Free floating ball thrombus of left atrium developing late after closed mitral commissurotomy - a case report

Left atrial ball thrombus is very rare entity and it is even rare to find a large free floating ball thrombus of left atrium in a post-operative patient. Thrombus of left atrium usually occurs in atrial fibrillation or in mitral valve stenosis. Here we are presenting a case of large ball thrombus of left atrium in a patient who underwent closed mitral commissurotomy 21 years back. A 50 years old female patient was admitted with history of breathlessness, palpitation and cough of one month duration. She was doing well after mitral valve commissurotomy. Her pre-operative trans-thoracic echocardiography showed a left atrial thrombus and severe mitral stenosis with valvular area of 0.7 cm² and atrial fibrillation. Per-operative trans-oesophageal echocardiography showed a large free floating ball thrombus of left atrium. She underwent removal of left atrial thrombus and mitral valve replacement using Sorin Bicarbon valve.     

Left circumflex coronary artery to left atrial fistula in a patient with mitral regurgitation after excision of a left atrial myxoma.

Acquired coronary artery to left atrial fistulas are rare and previously only described in mitral stenosis associated with left atrial thrombus or coronary arteriosclerosis. We present the case of a patient who developed a left circumflex coronary artery to left atrial fistula associated with mitral regurgitation 12 years after excision of a left atrial myxoma. This was successfully ligated at the time of mitral valve replacement.     

Cardiac valve replacement in patients on dialysis: influence of prosthesis on survival

BACKGROUND: Mechanical valves have been recommended for patients on dialysis because of purported accelerated bioprosthesis degeneration. This study was undertaken to determine time-related outcomes in dialysis patients requiring cardiac valve replacement. METHODS: From 1986 to 1998, 42 patients on chronic preoperative dialysis underwent valve replacement; 17 received mechanical valves and 25 received bioprostheses. Age was similar in both groups: 54+/-18.5 years (mechanical) and 59+/-15.5 years (bioprosthetic, p = 0.4). Sites of valve replacement were aortic (27), mitral (11), and aortic and mitral (4). Follow-up was 100% complete. RESULTS: Survival at 3 and 5 years was 50% and 33% after mechanical valve replacement, and 36% and 27% after bioprosthetic valve replacement (p = 0.3). Four patients with bioprostheses required reoperation: 3 for allograft endocarditis and 1 at 10 months for mitral bioprosthesis degeneration. One patient who received a mechanical valve required reoperation. CONCLUSIONS: Prosthetic valve-related complications in patients on dialysis were similar for both mechanical and bioprosthetic valves. Because of the limited life expectancy of patients on dialysis, bioprosthesis degeneration will be uncommon. Therefore, surgeons should not hesitate to implant bioprosthetic valves in these patients.     

Implantation of a mechanical valve in a previously implanted mitral bioprosthetic orifice in a patient with mitral bioprosthetic failure

Complete removal of a previously implanted dysfunctional mitral bioprosthesis could result in extensive damage. Therefore, a 66-year-old female patient with a deteriorated mitral bioprosthesis had leaflet excision, and a “new” mechanical valve was sewn onto the previously implanted bioprosthetic sewing cuff. On postoperative echocardiography, the implanted valve had good hemodynamic performance with no paravalvular leakage. The patient's clinical condition improved after surgery.     

LVAD support in patients with bioprosthetic valves

The presence of mechanical or bioprosthetic valves has traditionally excluded patients from mechanical circulatory support. However, several centers have now developed algorithms for the surgical management of native or prosthetic valve disease in patients requiring left ventricular assist device insertion. We report adverse events associated with bioprosthetic valves in the mitral and tricuspid positions in 2 patients who received long-term mechanical support. We recommend anticoagulation for all patients with prosthetic valves in the mitral or tricuspid position to avoid thromboembolism, inflow conduit occlusion, or valvular incompetence.     

A giant left atrial myxoma with severe mitral valve regurgitation: report of a case

A 76-year-old female underwent operation with a diagnosis of a left atrial myxoma with accompanied mitral regurgitation. Although no clinical findings of mitral regurgitation were noticed preoperatively, degenerative changes to the anterior leaflet as well as chordae tendinae possibly due to mechanical damage by the movement of the giant tumor through the mitral valve complex were observed in operation. Resection of the tumor and mitral valve replacement were successfully performed. Our case suggests that it is indispensable to investigate the mitral valve during operation even in case of the left atrial tumor with no preoperative findings of mitral regurgitation.     

Replacement of degenerated mitral and aortic bioprostheses without explantation.

BACKGROUND: The most common indication for reoperation in patients with a bioprosthetic valve is primary tissue failure. Explantation of the bioprosthesis is time consuming, and for a mitral valve, may be complicated by cardiac rupture at the atrioventricular junction or the posterior left ventricular wall where a strut is imbedded, injury to the circumflex artery, and late perivalvular leak; for an aortic valve, annular disruption and perivalvular leak may complicate explantation. A new approach to simplify these procedures and avoid these complications, by excising only the bioprosthetic tissue and attaching a bileaflet mechanical valve to the intact stent, was developed in 1991 and was evaluated over a 9-year period in 50 patients who had had one (34), two (10), three (4), or four (2) previous open cardiac operations. METHODS: Since 1991, we have replaced degenerated mitral bioprostheses in 34 patients (25 to 84 years of age; 12 male, 22 female) by preserving the stent and suturing a St. Jude or Carbomedics bileaflet valve to the atrial side of the bioprosthetic cuff; the mitral valve was exposed through a median sternotomy in 21 patients and through a right anterolateral thoracotomy in 13. Using a similar approach, starting in 1995, 16 additional patients (55 to 73 years of age; 11 male, 5 female) with degenerated aortic bioprostheses had the aortic valve replaced by excising the bioprosthetic tissue and amputating the struts, then suturing a Carbomedics valve to the aortic side of the bioprosthetic cuff. This allows the use of a bileaflet valve similar in size to the bioprosthesis with exact matching of the orifices. RESULTS: Bypass time averaged 61 +/- 14 minutes and aortic cross-clamp time 43 +/- 12 minutes. There has been no operative mortality. Three late deaths occurred at 9, 37, and 58 months, and were not valve related. No gradients of hemodynamic significance have been detected on transesophageal echocardiographic follow-up. CONCLUSIONS: Leaving the bioprosthetic cuff intact eliminates the need for extensive dissection, thus shortening and simplifying the procedure and diminishing its attendant mortality and morbidity. This valve-on-valve approach also allows replacement of a degenerated bioprosthesis with a bileaflet valve of comparable size rather than a smaller one jammed into the orifice of the bioprosthetic stent, thus avoiding undue trauma to the bileaflet valve and maintaining excellent hemodynamic function.     

Comparison of outcomes after mitral valve replacement with a mechanical versus a bioprosthetic valve in patients between forty and sixty years of age

Background  The American College of Cardiology/American Heart Association (ACC/AHA), guidelines for choice of prosthetic valve based on patients’ age are difficult to apply to the developing world because of a lower life expectancy and difficulty in maintaining correct levels of anticoagulation for a variety of reasons. While there is general agreement on the choice of prosthetic valves for patients below 40 years of age (mechanical) and above 60 years of age (biologic), the 40 to 60 age group remains a grey zone. The goal of our study was to compare outcomes after mitral valve replacement with a mechanical versus a bioprosthetic valve in patients between forty and sixty years of age. Methods  From Jan 2003 to July 2008, 250 patients between the ages of 40 and 60, undergoing mitral valve replacement at our institution were randomized to receive either a mechanical or a bioprosthetic valve. Outcomes in the form of incidence of valve thrombosis and thromboembolism, bleeding complications, incidence of prosthetic valve endocarditis and survival were compared in the two groups. Results  Out of 250 patients, 135 patients received mechanical valve and 115 patients were implanted with a bioprosthetic valve. Patients were followed up for a mean period of 3 years (range 6 months to 4.8 years). The incidence of valve thrombosis was higher in mechanical valve as compared to bioprosthetic valve (6% vs. 0.9%, p= 0.04). Similarly there was a higher incidence of thromboembolism in mechanical valves as compared to bioprosthetic valves (4.5% vs. 0%, p=0.03). Bleeding complications occurred more frequently in mechanical than bioprosthetic valve (6% vs. 0.9%, p=0.04). There was no significant difference in the incidence of prosthetic valve endocarditis (2.2% vs. 2.7%, p >0.05) or survival at three years (96.2% vs. 97.2%, p > 0.05) in the two groups. Conclusions  Patients in the age group of 40 to 60 years undergoing mitral valve replacement with a mechanical valve have a higher incidence of thrombotic and bleeding complications as compared to bioprosthetic valve, even though short term survival is similar. This favours implantation of a bioprosthetic valve in this age group.     

Late incidence and determinants of reoperation in patients with prosthetic heart valves.

OBJECTIVES: Reoperation is a relatively common event in patients with prosthetic heart valves, but its actual occurrence can vary widely from one patient to another. With a focus on bioprosthetic valves, this study examines risk factors for reoperation in a large patient cohort. METHODS: Patients (N=3233) who underwent a total of 3633 operations for aortic (AVR) or mitral valve replacement (MVR) between 1970 and 2002 were prospectively followed (total 21,179 patient-years; mean 6.6+/-5.0 years; maximum 32.4 years). The incidence of prosthetic valve reoperation and the impact of patient- and valve-related variables were determined with actual and actuarial methods. RESULTS: Fifteen-year actual freedom from all-cause reoperation was 94.1% for aortic mechanical valves, 61.4% for aortic bioprosthetic valves, 94.8% for mitral mechanical valves, and 63.3% for mitral bioprosthetic valves. In both aortic and mitral positions, current bioprosthesis models had significantly better durability than discontinued bioprostheses (15-year reoperation odds-ratio 0.11+/-0.04; P<0.01 for aortic, and 0.42+/-0.14; P=0.009 for mitral). Current bioprostheses were significantly more durable in the aortic position than in the mitral position (14.3+/-6.8% more freedom from 15-year reoperation; (P=0.018)). Older age was protective, but smoking was an independent risk factor for reoperation after bioprosthetic AVR and MVR (hazard ratio for smoking 2.58 and 1.78, respectively). In patients with aortic bioprostheses, persistent left ventricular hypertrophy at follow-up and smaller prosthesis size predicted an increased incidence of reoperation, while this was not observed in patients with mitral bioprostheses. CONCLUSIONS: These analyses indicate that current bioprostheses have significantly better durability than discontinued bioprostheses, reveal a detrimental impact for smoking after AVR and MVR, and indicate an increased reoperation risk in patients with a small aortic bioprosthesis or with persistent left ventricular hypertrophy after AVR.