Methods of estimation of mitral valve regurgitation for the cardiac surgeon

Mitral valve regurgitation is a relatively common and important heart valve lesion in clinical practice and adequate assessment is fundamental to decision on management, repair or replacement. Disease localised to the posterior mitral valve leaflet or focal involvement of the anterior mitral valve leaflet is most amenable to mitral valve repair, whereas patients with extensive involvement of the anterior leaflet or incomplete closure of the valve are more suitable for valve replacement. Echocardiography is the recognized investigation of choice for heart valve disease evaluation and assessment. However, the technique is depended on operator experience and on patient's hemodynamic profile, and may not always give optimal diagnostic views of mitral valve dysfunction. Cardiac catheterization is related to common complications of an interventional procedure and needs a hemodynamic laboratory. Cardiac magnetic resonance (MRI) seems to be a useful tool which gives details about mitral valve anatomy, precise point of valve damage, as well as the quantity of regurgitation. Finally, despite of its higher cost, cardiac MRI using cine images with optimized spatial and temporal resolution can also resolve mitral valve leaflet structural motion, and can reliably estimate the grade of regurgitation.     

Intraoperative transesophageal color-coded Doppler echocardiography for evaluation of residual regurgitation after mitral valve repair

Because mitral valve competence after mitral valve reconstruction is awkward to assess during this procedure, we evaluated in this respect transesophageal color-coded Doppler echocardiography in 23 patients undergoing mitral valve reconstruction for severe mitral regurgitation. Transesophageal echocardiographic examinations were performed after induction of anesthesia but before sternotomy (baseline), after mitral valve repair before decannulation, and at sternal closure, all at similar mean aortic pressure and echocardiographic instrument settings. The degree of mitral regurgitation by transesophageal color Doppler flow mapping was visually quantified on a 5-point scale (0 to 4), pending the left atrial extent of the regurgitant jet. This was compared with the degree of mitral regurgitation by left ventricular cineangiography performed within several weeks after operation and also visually quantified on a 5-point scale (0 to 4), with use of the right anterior oblique projection. There was good correlation between the two methods (r = 0.83; p less than 0.001). We conclude that residual mitral regurgitation, as assessed by transesophageal color flow mapping in the operating room, highly correlates with the ultimate mitral regurgitation by cineangiography. Therefore transesophageal echocardiography can be helpful for evaluation of mitral valve competence during mitral valve reconstruction, and hence, in case of repair failure, allow valve replacement in the same surgical session, thus avoiding reoperation.     

Long-term results of mitral valve repair for non-rheumatic mitral regurgitation

The durability of mitral valve repaired with reconstructive techniques is variable. If the durability continues to be good, mitral valve repair may be the procedure of choice in many patients with mitral regurgitation. Between December 1970 and June 1993, 54 patients had mitral valve repair for non-rheumatic mitral regurgitation. There were 38 men and 16 women with a mean age of 46.8 (range 19–68) years. The pathology which required surgical treatment was torn chordae in 38 patients, elongation of the chordae in five, valve prolapse without elongation or rupture of the chordae in six, infective endocarditis in three, and annular dilatation in two. Forty-four patients had triangular or quadrangular resection of the mitral leaflet, and seven had annuloplasty alone. Choral reconstruction was performed on three patients. There were no operative deaths. Five patients (9%) died late after operation. The actuarial survival rate and the valve-related death-free rate at 10 years were 83.9% and 90.0%, respectively. Seven patients (13%) required reoperation. Freedom from reoperation at 10 years was 84.5%. Improper evaluation of residual regurgitation during operation and suture dehiscence were the principal causes of reoperation. It was concluded that mitral valve repair for non-rheumatic mitral regurgitation showed low operative mortality and stable long-term results. It is suggested that intraoperative transoesophageal colour Doppler echocardiography provides accurate assessment of mitral valve competence and may be helpful in reducing the need for reoperation.     

Incidence, associated factors and evolution of non-severe functional mitral regurgitation in patients with severe aortic stenosis undergoing aortic valve replacement.

INTRODUCTION: In order to improve the prognosis, repair of severe mitral regurgitation should be undertaken at the same time as aortic valve replacement in patients with severe aortic valve stenosis. However, mitral regurgitation may be secondary to pressure overload or ventricular dysfunction and improve after surgery. AIM: To assess the incidence of non-severe functional mitral regurgitation before and after isolated aortic valve replacement and determine its influence on the postoperative course. METHODS: The clinical and surgical characteristics were compared in a cohort of 577 consecutive patients who underwent isolated aortic valve replacement. RESULTS: The mean age was 68.4+/-9.2 years (44% women). Non-severe functional mitral valve regurgitation was detected prior to surgery in 26.5% of the patients. These patients were older (p=0.009), more often had ventricular dysfunction (p=0.005) and pulmonary hypertension (0.002), and had been admitted more frequently for heart failure (0.002), with fewer of them conserving sinus rhythm (p<0.001). Additionally, the pre-surgery existence of mitral regurgitation was associated with greater morbidity and mortality (10.5% vs 5.6%; p=0.025). The mitral regurgitation disappeared or improved prior to hospital discharge in 56.2% and 15.6%, respectively. Independent factors predicting this improvement were the presence of coronary lesions (OR 3.7, p=0.038), and the absence of diabetes (OR 0.28, p=0.011) and pulmonary hypertension (0.33, p=0.046). CONCLUSIONS: The presence of intermediate degree mitral regurgitation in patients undergoing isolated aortic valve replacement increases morbidity and mortality. However, a high percentage of those who do survive experience disappearance or improvement of the mitral regurgitation.     

完全性房室通道的外科治疗

目的总结94例完全性房室通道(com p lete atrioven tricu lar cana l defect,CAVCD)的外科治疗经验。方法一期手术矫治CAVCD 94例,房、室间隔缺损修补用双片法(涤纶片+心包片)65例,单片法29例,术中行房室瓣成形,并同期修补合并畸形。结果全组死亡10例(10.6%),其中<6个月者4例。4例术后出现二尖瓣中至大量反流,心肺功能衰竭死亡,3例因肺动脉高压危象死亡,3例分别死于低心排血量、脑并发症和气胸。随访84例,随访时间3~6个月,超声心动图复查二尖瓣轻度反流18例,轻至中度反流12例。结论严重二尖瓣关闭不全和肺动脉高压危象是CAVCD矫治术后主要的死亡原因,早期手术矫治和确切的房室瓣成形可获得较好的手术效果,术中常规使用食管超声心动图对提高手术疗效具有重要的作用。     

Surgical treatment of ischemic mitral valve regurgitation.

In cases of old myocardial infarction, the presence of mitral valve regurgitation is one of the predicting factors of long-term prognosis. The mechanism of ischemic mitral regurgitation consists of mitral annular dilatation, left ventricular (LV) dilatation followed by tethering of the mitral valve, etc. Since long-term prognosis of the patients in whom the degree of mitral valve regurgitation is 2+ or more is typically poor, the mitral valve procedure should be considered at the time of coronary artery bypass grafting (CABG) or more. In this type of surgery, the treatment essentially involves the use of an artificial ring implantation as the basic technique. In the chronic stage, a significant degree of mitral regurgitation persists in approximately 20% of the cases if they have been treated by ring annuloplasty alone. Additional surgical procedures that reduce or eradicate the tethering are essential for the control of the regurgitation completely in cases with strong tethering. We recently employed two new surgical techniques, namely, cutting the secondary chordae to the anterior mitral valve leaflet and the anterior and posterior papillary muscle reapproximation. The surgical results of the acute phase appear to be promising; however, the long-term results of such new methods are yet to be determined. If the mitral valve regurgitation cannot be controlled even by various operative techniques of mitral valve repair, mitral valve replacement should be considered. This is because the long-term survival rate of the suboptimal repair surgical patients is lower when compared with that of mitral valve replacement patients.     

Papillary muscle sandwich plasty for the treatment of functional mitral valve regurgitation

We evaluated the availability of original "sandwich plasty" for the treatment of functional mitral regurgitation (FMR) associated with ischemic heart disease (IHD) and aortic valve disease (AVD). Forty-three patients were reviewed, including 27 IHD patients and 16 AVD patients. Preoperatively severe FMR was detected in 14 patients, moderate FMR in 26, and mild FMR in 3. The papillary muscle heads of anterior leaflets and posterior leaflets were approximated using Teflon-pledgeted 3-0 Ticron sutures at anterolateral and posteromedial commissural portions. After surgery, residual moderate FMR was observed in 1 patient and mild FMR in 3 patients. Tenting height of the mitral valve significantly decreased. FMR free rates 2 years after surgery were 93% among IHD patients and 83% in AVD patients. "Sandwich plasty" was simple and effective for the treatment of functional FMR caused by tethering effects due to left ventricular dilatation.     

Management and outcome of patients with abnormal ventriculo-arterial connections and mitral valve cleft

BACKGROUND: In patients with abnormal ventriculo-arterial connections, a mitral valve cleft different from an atrioventricular canal is occasionally associated. It may cause outflow obstruction, mitral regurgitation, and complicate biventricular repair. METHODS: A retrospective review identified 21 patients operated upon with mitral valve cleft, abnormal ventriculo-arterial connections, and two well-developed ventricles. Eight patients had a ventricular outflow obstruction due to the mitral valve, whereas 2 had more than mild mitral regurgitation. One patient required initial mitral valve surgery. Eleven patients underwent biventricular repair, associated with mitral valve repair in 2 cases: arterial switch operation (n = 4), Senning operation (n = 3) associated with an arterial switch operation in one case, intraventricular repair (n = 3), and Rastelli-type extracardiac conduit repair (n = 1). Single-ventricle palliation was preferred in 10 patients with major mitral valve straddling (n = 5), outflow tract obstruction (n = 2), and noncommitted or multiple VSDs (n = 3). RESULTS: There were three hospital deaths, two of which occurred after biventricular repair and one after an early reoperation after a bidirectional cavopulmonary anastomosis. Postoperatively after biventricular repair, 1 patient required permanent pacemaker implantation and 3 patients were reoperated on for subaortic stenosis (n = 1) and mitral regurgitation (n = 2), with one late death. By multivariate analysis, patients with a double-outlet right ventricle were at greater risk of death (p = 0.04). After a mean follow-up period of 60.7 months (+/- 68.6 months), 16 patients are in New York Heart Association (NYHA) class I. One patient with a moderate mitral regurgitation on Doppler study is in NYHA class II. CONCLUSIONS: The surgical management remains controversial in patients with abnormal ventriculo-arterial connections and mitral valve cleft. Biventricular repair may not always be feasible, especially in cases of complex intracardiac anatomy associated with mitral valve straddling. Single-ventricle palliation can be achieved in these patients, although it is unknown whether the long-term results are as good as those obtained with biventricular repair.     

Transcatheter mitral valve therapies: State of the art

Mitral regurgitation (MR) is one of the most prevalent valvular pathologies in the developed world. There continues to be a growing population of aging patients with MR who may be too high risk for surgical management. The rapid adoption and remarkable success of transcatheter aortic valve replacement (TAVR) generated enthusiasm for transcatheter mitral valve therapies; however, the complex anatomy and pathophysiology of the mitral valve confers several unique challenges for a fully percutaneous approach. Nevertheless, several devices are under development and in various phases of preclinical or clinical testing, both for transcatheter mitral valve replacement and repair. MitraClip (Abbott Vascular), which has received FDA approval, is the most established percutaneous repair strategy and has been performed in over 80,000 patients as of 2019. The following article serves as a review of the available and upcoming devices for the various etiologies of mitral valvular disease, as well as the unique challenges and potential complications of transcatheter mitral valve intervention.     

复杂性二尖瓣反流的外科修复

目的 评价多技术综合运用治疗复杂性二尖瓣反流的近、中期疗效.方法 2000年1月至2006年7月,34例综合应用多技术治疗多区域复杂性二尖瓣反流者,男24例,女10例.年龄23～65岁,平均(42.8±11.7)岁.其中退行性变29例,外伤(包括可疑病史)2例,马方综合征2例,缺血性1例.术前超声提示二尖瓣反流中度11例(32.4%),重度23例(67.6%).术前心功能(NYHA)分级:Ⅱ级9例(26.5%),Ⅲ级16例(47.1%),Ⅳ级9例(26.5%),平均(3.00±0.74)级.比较其术前、术后心功能、左心室、左心房直径和二尖瓣反流程度的变化.结果 无住院死亡,无手术并发症.随访1～54 个月,平均(31.2±19.4)个月.随访期无死亡,无并发症,无再次手术者.术后左心房直径从术前(53.23±7.69)mm减至(38.25±6.32)mm(P<0.05),左心室舒张末径从术前(63.74±9.64)mm减小至(48.76±7.56)mm(P<0.05),左心室收缩末径从术前(49.39±7.14)mill减小至(35.49±6.21)mm(P<0.05).术后心功能较术前明显改善,平均降至(1.62±0.78)级(P<0.05).射血分数(EF)术前0.55±0.11,术后0.57±0.10,无明显提高(P>0.05).二尖瓣反流程度术后明显减轻,术中食管超声0.91±0.90,随访期间1.18±0.99(P<0.05).结论 合理综合应用多技术可以有效治疗复杂性多区域二尖瓣反流,中期疗效满意.     

影像学定量分析二尖瓣研究进展

二尖瓣反流是一种常见的心脏瓣膜疾病。二尖瓣的三维立体结构复杂,各组成部分协调工作,使血液顺利从左心房泵入左心室。全面、准确定量评估二尖瓣结构有利于制定最佳治疗方案,选择手术时机及评估预后。本文对影像学定量测量二尖瓣研究进展进行综述。     

Surgical results for mitral regurgitation from coronary artery disease

Results of coronary artery bypass grafting with and without mitral valve replacement were analyzed retrospectively in 101 patients with preoperative ischemic mitral regurgitation to determine the effects of severity and surgical treatment of mitral regurgitation on survival. Between 1980 and 1984, a total of 1,475 patients (mean age 59, 77% male) underwent coronary bypass. These patients were divided into three groups: (1) patients without ischemic mitral regurgitation who underwent isolated coronary bypass (1,374; 93%), (2) patients with ischemic mitral regurgitation who underwent isolated coronary bypass without valve replacement (85; 6%), and (3) patients with ischemic mitral regurgitation who underwent combined mitral valve replacement and coronary bypass (16; 1%). Preoperatively, patients with ischemic mitral regurgitation compared to those without regurgitation were significantly older (+6 years, p less than 0.001), had more severe coronary artery disease (p less than 0.001), a higher incidence of congestive heart failure (24% versus 5%, p less than 0.001) and recent myocardial infarction (16% versus 8%, p less than 0.01), and a lower mean ejection fraction (45% versus 61%, p less than 0.001). Operative mortality was significantly increased in patients with ischemic mitral regurgitation who underwent coronary bypass alone (p less than 0.01) and in those who underwent coronary bypass and mitral valve replacement (p less than 0.01)--11% and 19%, respectively--than in the coronary bypass patients without ischemic mitral regurgitation (3.7%). The severity of mitral regurgitation (0 to 4+) proved to be the most significant predictor of operative mortality. The actuarial survival rate at 5 years for the coronary bypass patients without ischemic mitral regurgitation was 85% compared to 91% (p less than 0.05) for the coronary bypass patients without ischemic mitral regurgitation. These results indicate that patients with ischemic mitral regurgitation have a higher prevalence of cardiac risk factors and are at an increased risk of operative mortality. Although the severity of the ischemic mitral regurgitation was strongly predictive of early survival, it proved to have an unexpectedly modest effect on long-term survival after surgical treatment.     

Current surgical treatment for acquired valvular heart disease

We discuss the current status of surgical treatment for acquired valvular heart disease. Mitral valve repair for organic and functional mitral regurgitation is the first choice instead of valve replacement. It is important that surgery for functional mitral regurgitation restores the geometry of the left ventricle and mitral valve. The reduction of mitral valve tethering for functional mitral regurgitation is a current topic of discussion. At present, the surgical procedure for both aortic stenosis and aortic regurgitation is valve replacement in most cases, although aortic valve repair has been attempted for aortic regurgitation in recent years. The early results of aortic valve repair are excellent, but the long-term results have not been clarified. The durability of valve repair in both the mitral and aortic position is a future issue and it may be improved by revising the indications for valve repair and using new surgical techniques.     

Die interventionelle Therapie der Mitralklappeninsuffizienz

Surgical mitral valve repair remains the gold standard treatment for significant mitral regurgitation achieving excellent results especially in degenerative mitral valve disease. Due to comorbidities and high surgical risk, a substantial number of patients are left untreated. It is especially for these patients that interventional and less invasive devices need to be explored. Most of the currently investigated technologies mimic surgical methods of valvuloplasty, annuloplasty, and valve replacement. Edge-to-edge repair with the MitraClip? device imitates the Alfieri stitch and obtained encouraging results in a randomized trial compared with surgical mitral valve repair. Due to its high safety profile, this approach can already be seen as complimentary to surgery for patients with functional mitral regurgitation and poor left ventricular function. A close interdisciplinary collaboration of cardiologists and cardiac surgeons is essential for a successful interventional mitral valve program.     

Repair of prosthetic mitral valve paravalvular leak using an off-pump transapical approach

Patients who present with significant paravalvular regurgitation after mitral valve replacement remain a difficult patient population and high-risk surgical candidates. We present 3 cases of transapical closure of mitral valve paravalvular leak (PVL) after mitral valve replacement using Amplatzer closure devices (AGA Medical Corp, Plymouth, MN). All 3 patients experienced decreased regurgitation at the site of the closure as well as symptomatic improvement in their heart failure.     

Accurate quantitation of regurgitant volume with MRI in patients selected for mitral valve repair.

OBJECTIVE: Echocardiography, the currently preferred diagnostic approach for mitral valve regurgitation, cannot accurately quantify the amount of regurgitation. Flow quantification with MRI is possible, but the conventional method (1-directional velocity-encoding) acquires the flow at a fixed location during the cardiac cycle, which is not necessarily the location of the mitral valve during the whole cycle. In this study, the exact flow through the mitral valve was quantified with a 3-directional velocity-encoded MRI approach. METHODS: Ten patients with severe mitral valve regurgitation (class 3-4+with echocardiography) resulting from systolic restrictive motion of both leaflets (Carpentier IIIb) which were selected for valve repair and 10 healthy volunteers without cardiac valvular disease confirmed with echocardiography were included in this study. The intra-ventricular flow was sampled with a radial stack of six acquisition planes parallel to the long-axis of the left ventricle. Three-directional velocity-encoded MRI was performed resulting in the intra-ventricular flow velocity vector field for 30 phases during the cardiac cycle. The position of the mitral valvular plane in this vector field was indicated manually for each phase. Velocity values perpendicular to this plane determined the flow through the mitral valve. Both the 3-directional encoded mitral valve flow and the 1-directional encoded mitral valve flow were compared with the flow determined with MRI at the ascending aorta. RESULTS: One-directional velocity-encoded MRI showed a mean overestimation (P<0.01) of 25 ml/cycle compared to the aortic flow. Correlation was very poor (r(P)=0.15, P=0.68). The 3-directional velocity-encoded MRI on the other hand, showed no over/underestimation and a good correlation (r(P)=0.91, P<0.01 for volunteers, r(P)=0.90, P<0.01 for patients). The regurgitant flow fractions were between 3 and 30%. CONCLUSION: With 3-directional velocity-encoded MRI, measurement of the flow through the mitral valve is accurate and reproducible. This is a valuable tool for diagnosing and absolute quantification of regurgitant volume.     

Does the additive risk of mitral valve repair in patients with ischemic cardiomyopathy prohibit surgical intervention?

OBJECTIVE: To assess the surgical risk of additional mitral valve repairs in patients with ischemic cardiomyopathy. SUMMARY BACKGROUND DATA: Severe mitral regurgitation in patients with ischemic cardiomyopathy increases the death rate and symptomatic status. The 1-year survival rate for medical therapy in this subset of patients is less than 20%. Transplantation is usually not feasible because of donor shortage and death while on the waiting list. METHODS: To assess additive risk, a retrospective chart review from 1993 to 1998 was performed comparing patients with ischemic cardiomyopathy (ejection fraction [EF] <25%) and severe mitral regurgitation undergoing mitral valve repair and coronary artery bypass graft operations with patients with an EF of <25% undergoing coronary artery bypass graft alone. These groups were also compared with 140 patients receiving heart transplants since 1993 (group 3). RESULTS: The overall hospital death rate for group 1 was 6.3%. The one death occurred 2 weeks after surgery secondary to sepsis. This was not significantly different from the death rate of 4.1% in group 2. In group 1, there were two deaths at 1 year (87% survival rate), one related to heart failure. One patient was New York Heart Association (NYHA) class IV at 1 year; the remainder of patients were NYHA class I-II. These results were not significantly different than the 8% death rate noted with transplantation. There was no change in EF and minimal residual mitral regurgitation in group 1 based on postoperative transesophageal echocardiography, whereas group 2 had an average 11.7% improvement in EF. CONCLUSIONS: Previously, severe mitral regurgitation in the setting of ischemic cardiomyopathy has been associated with poor survival. In these authors' experience, repairing the mitral valve along with coronary artery bypass grafting does not increase the surgical risk, yields improvement in symptomatic status, and compares favorably to coronary artery bypass grafting alone and cardiac transplantation. However, the lack of change in EF in these patients probably represents an overestimation of the EF before surgery secondary to severe mitral regurgitation.     

Partial tricuspid valve transfer for repair of mitral insufficiency due to ruptured chordae tendineae

BACKGROUND: A new technique is suggested for the reconstructive surgical treatment of mitral regurgitation. It involves partial transfer of the tricuspid valve of the patient to the mitral valve, in order to provide chordae to correct anterior leaflet prolapse of the mitral valve, secondary to rupture of the chordae tendineae. METHODS: From January 1991 to May 1997, 20 patients with mitral insufficiency due to rupture of the chordae were operated on. The prevailing cause was myxomatous degeneration (70%). Patients were in New York Heart Association functional class III and IV. RESULTS: There were no hospital deaths. Two patients were reoperated on. Eighteen patients (90%) are alive with their own valves (class I and II). Doppler echocardiogram mean values were: ejection fraction, 0.65; left atrial diameter, 4.2 cm; mitral area, 2.4 cm2; mitral transvalvular gradient, 3.3 mm Hg. No regurgitation or mild regurgitation was observed in 16 (94.1%) of the 17 cases evaluated. Mean tricuspid valvular area was 3.3 cm2. In all cases, no tricuspid regurgitation was present or it was mild. CONCLUSIONS: Partial transfer of the tricuspid valve to the mitral valve is an effective procedure for the surgical treatment of mitral valve insufficiency secondary to ruptured chordae tendineae of the anterior leaflet.     

Mitral valve surgery for patients after undergoing percutaneous transvenous mitral commissurotomy (PTMC)--investigation on indication of PTMC based on the intraoperative findings]

Ten patients underwent open heart surgery for mitral valve after PTMC because of post PTMC MS (n = 4) and MR (n = 6) out of 150 patients undergoing PTMC in our hospital between June 1987 and October 1991. Intraoperative findings of 4 patients with residual mitral stenosis included severe thickening, stiffening and calcification on anterior and posterior leaflets, commissures and subvalvular apparatus. Mitral valve repair was possible in 2 and mitral valve replacement (MVR) was necessary in the other 2. In all 6 cases who massive mitral regurgitation after PTMC, in repairable tears in the mitral leaflets necessitated MVR. Since in these cases changes in the leaflets were less severe than those of the commissures or subvalvular apparatus, surgical repair could have been possible if open mitral commissurotomy (OMC) was done primarily. Patients selection for PTMC versus OMC based on precise morphological evaluation of mitral valve would reduce occurrence of massive MR resulting in surgical replacement.     

Mitral valve surgery in infants and children

The pre-operative findings and surgical results of forty-three patients under thirteen years of age undergoing mitral valve surgery, are presented. Eight underwent surgery for mitral stenosis. Four had open mitral valvotomy with a satisfactory result, one developed severe regurgitation which required mitral valve replacement. Two had primary valve replacement and two had excision of a mitral subvalvar diaphragm. Thirty five children underwent surgery for mitral regurgitation. Twelve had a mitral annuloplasty. Two of these developed further regurgitation which required mitral valve replacement. Twenty one children had primary mitral valve replacement. The results and choice of valve replacement are discussed.