Percutaneous transluminal valvuloplasty of the mitral valve

Percutaneous transluminal balloon valvuloplasty for mitral stenosis represents an alternative method of treatment to standard surgical procedures of open or closed commissurotomy as well as valve replacement. In this overview, our results will be reported with respect to derivation of a summary of indications and contraindications for the procedure. Valvuloplasty for mitral stenosis was carried out in 62 patients, mean age 43 +/- 17 years, 48 women and 14 men. In 14 of the patients surgical procedures had been performed previously including an open or closed commissurotomy or isolated aortic valve replacement. Nine patients were in NYHA class II, 50 in class III and three in class IV. Markedly impaired motion of the valve and calcification was present in 15 patients. In 47 patients, the valve motion was relatively good and associated with mild changes in the subvalvular apparatus in 29 and marked changes in 18. In 54 patients the valvuloplasty was carried out with a combination of two balloon catheters, one 3 X 10 mm trefoil catheter and a single-balloon catheter of 15 mm (n = 16) or 19 mm (n = 38) diameter. Both catheters were inserted via the right femoral vein. The procedure required an average of one and one-half hours. Before and after valvuloplasty, complete right heart catheterization with oxymetric determinations were carried out to detect possible shunts at the atrial level and left ventriculography for detection of mitral regurgitation was performed in addition to echocardiography and Doppler examinations with continuous, pulsed-wave and color Doppler studies.(ABSTRACT TRUNCATED AT 250 WORDS)     

Mitral valve repair versus mitral valve replacement

Zusammenfassung In den letzten 40 Jahren hat die Mitralklappenchirurgie einen grundlegenden Wandel erfahren. Der initialen Begeisterung nach der Einführung von Klappenprothesen in den 60er Jahren folgte eine Renaissance der Rekonstruktion der Mitralklappe mit der Vorstellung der Ringannuloplastie-Technik in den 70er Jahren. Die Rekonstruktion der Mitralklappe erhält die Integrität der subvalvluären Strukturen, die eine entscheidende Rolle für die linksventrikuläre Funktion spielen. Große Studien, die sowohl Früh- als auch Langzeitergebnisse nach Mitralklappenrekonstruktionen gegenüber prothetischem Klappenersatz betrachteten, zeigten eine geringere Operationsmortalität sowie eine deutlich höhere Langzeitüberlebensrate bei Patienten nach Mitralklappenrekonstruktion. Weiterhin sind spezifische Probleme, wie Thromboembolien oder Endokarditis, die bei Klappenersatzverfahren auftreten können, zu nennen. In Anbetracht dieser Tatsachen sind klappenerhaltende Rekonstruktionstechniken von Vorteil. Jedoch ist die Entscheidung für eine Mitralklappenrekonstruktion von unterschiedlichen Faktoren abhängig, wie der Ätiologie der Mitralklappenerkrankung und der daraus folgenden Pathomorphologie der Klappe, sowie patientenabhängigen Einflüssen, wie z.B. Alter oder Kontraindikationen für eine Antikoagulationstherapie und nicht zuletzt der Erfahrung des Chirurgen. Somit ist der Prozess der Wahl eines geeigneten Operationsverfahrens sehr komplex und individuell von jedem Patienten abhängig zu machen. Sowohl Studiendaten als auch Datenbanken großer Patientenkollektive reflektieren die Vorteile der Mitralklappenrekonstruktion mit einem Rekonstruktionsanteil von bis zu 75 % in der gesamten Mitralklappenchirurgie. In den letzten 5 Jahren wurde der videoassistierte Zugang zur Mitralklappe über eine rechtslaterale Minithorakotomie zu einem etablierten Verfahren entwickelt. Dieser minimalinvasive Zugang erlaubt sowohl komplexe Rekonstruktions- als auch Klappenersatzverfahren unter anderem mit gerüstfreien Bioprothesen. Zusätzliche chirurgische Verfahren, wie die linksatriale Hochfrequenzablation zur Herstellung eines Sinusrhythmus bei Patienten mit Vorhofflimmern, verbessern das Operationsergebnis nach Mitralklappenchirurgie sowohl hinsichtlich der kardialen Funktion als auch der Lebensqualität für den Patienten deutlich und können ebenfalls über den minimalinvasiven Zugang durchgeführt werden. Summary Over the past 40 years mitral valve surgery has changed dramatically. After initial enthusiasm with the introduction of valve prostheses in the 1960s, a renewed interest in repair techniques began in the 1970s with the introduction of annuloplasty rings. These repair techniques revealed that the integrity of the subvalvular apparatus plays an important role in left ventricular function. When considering the major series comparing early and late results of mitral valve repair versus prosthetic mitral valve replacement, operative mortality rate is lower for patients with mitral valve repair. Long-term results also show a superior survival rate after mitral valve reconstruction. In addition, several problems can occur with the prosthetic valve, such as thromboembolism and endocarditis. All of these factors favor valve repair over replacement. The success of mitral valve repair depends on many factors: etiology of the mitral valve disease and the resultant pathomorphology of the valve, patient's circumstances such as age or contraindication for anticoagulation, and the experience of the surgeon. The decision whether to repair or replace the mitral valve depends on these factors. Data in the literature and in large collective databases reflect the advantages of mitral valve repair, with over 75 % of current mitral valve surgeries being repairs. In the past 5 years the exposure of the mitral valve through a right lateral minithoracotomy using video assistance has developed into a widespread technique. This approach allows complex mitral valve repair as well as mitral valve replacement even with biological stentless prostheses, with decreased morbidity. The addition of radiofrequency ablation for restoration of sinus rhythm enhances the outcome after mitral valve surgery, and can also be easily performed through a minithoracotomy technique.     

Mitral valve repair versus replacement in simultaneous aortic and mitral valve surgery

BACKGROUND:

Double valve replacement for concomitant aortic and mitral valve disease is associated with substantial morbidity and mortality. Excellent results with valve repair in isolated mitral valve lesions have been reported; therefore, whether its potential benefits would translate into better outcomes in patients with combined mitral-aortic disease was investigated.

METHODS:

A retrospective observational study was performed involving 341 patients who underwent aortic valve replacement with either mitral valve repair (n=42) or double valve replacement (n=299). Data were analyzed for early mortality, late valve-related complications and survival.

RESULTS:

The early mortality rate was 11.9% for valve repair and 11.0% for replacement (P=0.797). Survival (± SD) was 67±11% in mitral valve repair with aortic valve replacement and 81±3% in double valve replacement at five years of follow-up (P=0.187). The percentage of patients who did not experience major adverse valve-related events at five years of follow-up was 83±9% in those who underwent mitral valve repair with aortic valve replacement and 89±2% in patients who underwent double valve replacement (P=0.412). Age >70 years (HR 2.4 [95% CI 1.1 to 4.9]; P=0.023) and renal dysfunction (HR 1.9 [95% CI 1.2 to 3.7]; P=0.01) were independent predictors of decreased survival.

CONCLUSIONS:

In patients with double valve disease, both mitral valve repair and replacement provided comparable early outcomes. There were no significant differences in valve-related reoperations, anticoagulation-related complications or prosthetic valve endocarditis. Patient-related factors appear to be the major determinant of late survival, irrespective of the type of operation.     

Mitral valve repair for significant mitral insufficiency.

There has been skepticism since the early days of open heart surgery that good long-term or even short-term results were possible with repair of pure mitral insufficiency. The authors report 145 patients in whom a markedly insufficient mitral valve was repaired 6 months to 17 years previously and another 55 patients in whom repair of the insufficient mitral valve was performed along with myocardial revascularization from 6 months to 7 years previously. Comparative data with other published work reveals superior results with repair than with replacement with Starr-Edwards and Hancock glutaraldehyde-treated porcine valves and with far less emboli. Conservatism is urged in operating upon patients with mitral insufficiency. Repair of the valve rather than replacement is stressed for those patients requiring surgery.     

Percutaneous transluminal valvuloplasty in aortic valve stenosis in children

Percutaneous transluminal balloon valvuloplasty has been used in children since 1983 to treat tight aortic valve stenosis. Although more than 100 cases have been published, its indications compared with those of surgical valvulotomy have not yet been clearly defined. Twelve patients with tight aortic valve stenosis underwent transluminal balloon valvuloplasty: 3 were infants whose ages ranged from 1 month and 24 days to 3 months and 23 days (mean 80 +/- 13.7 days), and 9 were children aged from 4 to 17 years (mean 10.44 +/- 4.61 years). Aortic regurgitation grade I (5) or grade III (1) was present in 6 cases. An 8-year old child had previously undergone surgical aortic valvulotomy simultaneously with repair of aortic coarctation. Other associated malformations were congenital grade III mitral regurgitation in 1 case and Turner's syndrome in 1 case. Dilatation was performed with one or two successive balloons in 11 patients and with two balloons concomitantly in 1 patient. The diameter of the balloon (or the sum of those of the two balloons) was 77 to 112 percent of the diameter of the aortic annulus, but in one case this figure rose to 119 percent after failure of dilatation with a smaller balloon. One infant died at the end of the dilatation, due to perforation of the left ventricle. Another infant developed inferior myocardial infarction which followed a favourable course and left minimal sequelae.(ABSTRACT TRUNCATED AT 250 WORDS)     

Percutaneous transluminal balloon valvuloplasty for pulmonary valve stenosis

Transluminal balloon valvuloplasty was used to treat congenital pulmonary valve stenosis in 20 patients. Follow-up cardiac catheterization was performed in 11 patients at intervals of from 2 to 12 months after the procedure. Peak systolic pressure gradient across the pulmonic valve decreased from 68 +/- 27 to 23 +/- 5 mm Hg (p less than .001) after valvuloplasty. There were no complications. Follow-up catheterization demonstrated persistent relief of right ventricular hypertension in the patients with typical pulmonary valve stenosis.     

Percutaneous transluminal balloon valvuloplasty in congenital pulmonary valve stenosis

From March 1984 to September 1986, 49 transluminal balloon valvuloplasties (TBVs) were performed in 44 consecutive patients with congenital pulmonary valve stenosis, aged 1 day to 60 years. Seventeen of the patients were infants aged less than 1 year, five of whom were neonates. The peak systolic gradient was greater than 50 mm Hg (mean, 80.0 mm Hg) in 36 patients and was less than 50 mm Hg (mean, 35.4 mm Hg) in eight. A single balloon catheter was used in 41 cases, and two balloon catheters were used in eight cases. In patients with a gradient greater than 50 mm Hg, the mean right ventricular peak systolic pressure was reduced from 99.8 to 51.8 mm Hg, and the mean transvalvular gradient was reduced from 80.0 to 22.4 mm Hg. In infants and neonates, the mean right ventricular pressure expressed as a percentage of systemic pressure decreased from 122.2% to 63.5%. Follow-up cardiac catheterization 1 to 17 months later (in 19 cases) revealed no significant change in the right ventricular systolic pressure (which had decreased from 53.0 to 48.5 mm Hg) or the peak systolic pressure gradient (which had decreased from 29.0 to 24.5 mm Hg), in comparison with the changes seen immediately after TBV. Thus, TBV is an effective method of relieving pulmonary stenosis in patients of all ages, including neonates.     

Aortic and mitral valve replacement in a patient with hemophilia B

A 25-year-old man with factor IX deficiency had an aortic and mitral valve replacement using a 2M Starr Edwards valve in the mitral position and a 22 Medtronic valve in the aortic position under cover of factor IX concentrate. The surgical procedure and the immediate postoperative period were uneventful except for a pericardial effusion which required a pericardiostomy. He was anticoagulated with heparin in the immediate postoperative period while the factor IX concentrate was being administered. Oral anticoagulation with acenocoumarol (Acitrom) was started, maintaining the international normalized ratio between 1.5 and 2. He was doing well at follow-up 9 months later.     

Mitral valve repair versus replacement

When considering all the major series comparing the early and late results of mitral valve repair versus prosthetic or bioprosthetic mitral valve replacement, the operative mortality rate is slightly lower for patients undergoing valve reconstruction. Late survival is also superior after valve repair. Although these modest differences may be related to patient selection bias, a lower rate of thromboembolic and endocarditis-related complications and improved LV function remain as rather compelling factors favoring valve repair. The durability of valve repair is comparable to valve replacement in terms of reoperation rate, except in cases of rheumatic valve abnormality (in which reoperation rates are higher after valvuloplasty). Definitive, objective evidence favoring mitral valve repair is lacking given the short period of followup in all studies and absence of controlled, randomized clinical trials. The success of mitral valve reconstruction relies heavily on the experience and technical expertise of the surgeon. The wide variability in observed survival rates, however, is unlikely to be due to differences in surgical skill between experienced groups; it more likely represents the results of differing criteria for mitral valve repair, various followup intervals, and comparisons between distinctly different cohorts. Although a prospective randomized trial would be ideal to compare the results of mitral valve reconstruction versus mitral valve replacement for patients with mitral valve regurgitation, it is unlikely and unrealistic that such a study will ever be conducted. The universal applicability of the results of such a study would also be dubious, given the widely varying extent of surgical expertise with mitral valve repair. Furthermore, not all types of mitral regurgitation are amendable to reconstruction short of using patch techniques (usually autologous pericardium treated with glutaraldehyde) or resorting to artificial chordae (e.g., extensive leaflet destruction from rheumatic changes or infective endocarditis, and substantial anterior leaflet redundancy). In cases in which mitral valve replacement is necessary, preservation of the mitral subvalvular apparatus promises to be an important concept to preserve optimal systolic LV function postoperatively.     

Mitral valve repair for mitral regurgitation

We analyzed the results of mitral valve repair in 81 consecutive patients with severe mitral regurgitation. Of these patients, 66.6% had myxomatous degeneration, 11% ischemic disease, 8% chordal rupture, 5% congenital disease, and 3.7% endocarditis. Repair could not be achieved in five patients, and valve replacement was necessary. Six died during surgery (mortality 7%). During follow-up (mean 30 [8] months), there was one death due to refractory ischemic heart failure and mitral regurgitation (>or= 2/4) was observed in 11 patients. A good result (i.e., survival without a prosthesis, major complications, or mitral regurgitation >1/4) was obtained in 78% of patients with myxomatous degeneration versus 48% of those with other etiologies (P=.023). A good result was obtained more frequently in cases of isolated posterior cusp degeneration than in those involving degeneration of both cusps (85% vs 70%; P=.03).     

Percutaneous edge-to-edge mitral valve repair

In the past few years, a myriad of technologies have been developed for percutaneous repair of the mitral valve for patients with severe mitral regurgitation (MR) and at high risk for traditional open-heart mitral valve surgery. Among them, MitraClip has emerged as the only clinically safe and effective method for percutaneous mitral valve repair. This device mimics the surgical edge-to-edge mitral valve repair initially described by Dr. Alfieri. In this article, we review the current clinical evidence on the use of the MitraClip—from the randomized control trial EVEREST II to the information derived from expert high-volume centers.     

Percutaneous balloon valvuloplasty for bioprosthetic mitral valve stenosis

Percutaneous transcatheter mitral valvuloplasty is the indicated treatment of choice for symptomatic native mitral valve stenosis, but there have been limited reports of successful procedures of balloon valvuloplasty for bioprosthetic mitral valve stenosis. We present the case of a 62-year-old woman suffering from progressive dyspnea due to bioprosthetic mitral valve stenosis. The measured mean pressure gradient across the mitral valve was 30 mmHg and the mitral valve area was 0.73 cm². Redoing mitral replacement was considered high risk and was refused by the patient. Percutaneous balloon valvuloplasty was performed with an Inoue balloon catheter inflated to 20 mm. The patient’s symptoms immediately improved after the procedure, with no procedure-related complications. The mean pressure gradient across the valve decreased to 19 mmHg, and the mitral valve area increased to 1.21 cm² in postprocedural echocardiography. We conducted a literature search and identified 26 cases of balloon valvuloplasty for degenerated bioprosthetic valves. Of these, 14 cases were bioprosthetic mitral valves, and the results were favorable. However, more case reports are required to establish an evidence base for future expert recommendation of balloon valvuloplasty of prosthetic mitral valve. Meanwhile, balloon valvuloplasty will serve a niche role in highly selected patients with prosthetic mitral valve stenosis.     

Percutaneous transarterial balloon valvuloplasty for mitral valve stenosis

A new technique was developed that allows mitral commissurotomy without surgery. A balloon catheter was inserted percutaneously from the left femoral artery over a long guidewire introduced into the right femoral vein and advanced transseptally through the Brockenbrough catheter to the left ventricle and drawn out of the body through the left femoral artery using an intravascular retriever set. This procedure was performed in 3 patients with moderate mitral stenosis. After the procedure, the mean diastolic pressure gradient across the mitral valve was reduced and left ventriculography revealed no resultant mitral regurgitation in any of the patients. The procedure was easy to perform and caused no complications.     

Percutaneous mitral valve repair for mitral regurgitation

Mitral regurgitation (MR) associated with, ischemic, and degenerative (prolapse) disease, contributes to left ventricular (LV) dysfunction due to remodeling, and LV dilation, resulting in worsening of MR. Mitral valve (MV) surgical repair has provided improvement in survival, LV function and symptoms, especially when performed early. Surgical repair is complex, due to diverse etiologies and has significant complications. The Society for Thoracic Surgery database shows that operative mortality for a 1st repair is 2% and for re-do repair is 4 times that. Cardiopulmonary bypass and cardiac arrest are required. The attendant morbidity prolongs hospitalization and recovery. Alfieri simplified mitral repair using an edge-to-edge technique which subsequently has been shown to be effective for multiple etiologies of MR. The MV leaflers are typically brought together by a central suture producing a double orifice MV without stenosis. Umana reported that MR decreased from grade 3.6 +/- 0.5 to 0.8 +/- 0.4 (P < 0.0001) and LV ejection fraction increased from 33 +/- 13% to 45 +/- 11% (P = 0.0156). In 121 patients, Maisano reported freedom from re-operation of 95 +/- 4.8% with up to 6 year follow-up. Oz developed a MV "grasper" that is directly placed via a left ventriculotomy and coapts both leaflets which are then fastened by a graduated spiral screw. An in-vitro model using explanted human valves showed significant reduction in MR and in canine studies, animals followed by serial echo had persistent MV coaptation. At 12 weeks the device was endothelialized. These promising results have paved the way for a percutaneous or minimally invasive-off pump mitral repair. Evalve has developed catheter-based technology, which, by apposing the edges of a regurgitant MV, results in edge-to-edge repair. Release of the device is done after echo and fluoroscopic evaluation under normal loading conditions. If the desired effect is not produced the device can be repositioned or retrieved. Animal studies show excellent healing, with incorporation of the device into the leaflets at 6-10 weeks with persistent coaptation. Another percutaneous approach has been to utilize the proximity of the coronary sinus (CS) to the mitral annulus (MA). Placement of a self-compressing device in the CS along the region of the posterior MA has, in canine models, reduced MR and addresses the issues of MA dilation and its contribution to MR. Ongoing studies are underway for both techniques.