Is Prosthetic Anuloplasty Necessary for Durable Mitral Valve Repair?

Combination of the Modified Loop Technique and De Vega Annuloplasty in Dogs with Mitral Regurgitation

Background: Detailed surgical techniques for treating canine mitral regurgitation have not been previously reported. Method: This case series included six consecutive client-owned dogs with mitral regurgitation. All dogs underwent a combined protocol, including the modified loop technique and De Vega annuloplasty (MODEL surgery), in 2021. Artificial loops covering 80% of the length of the strut chordae tendineae were used for chordal replacement. Mitral annuloplasty was subjectively performed, targeting the circumference of the septal leaflet. Results: The breeds were Chihuahua-mixed breed, Spitz, Pomeranian, Cavalier King Charles Spaniel, and Chihuahua, with average ages and weights of 11.4 ± 2.3 years and 5.49 ± 2.98 kg, respectively. The aortic cross-clamp, pumping, and surgery times were 64.0 ± 7.5 min, 168.5 ± 39.1 min, and 321.0 ± 53.1 min, respectively. After MODEL surgery, left atrial-to-aortic ratios significantly decreased from 2.20 ± 0.18 to 1.26 ± 0.22 (p < 0.01), and left ventricular end-diastolic internal diameter normalized to body weight significantly decreased from 2.03 ± 0.26 to 1.48 ± 0.20 (p < 0.01). In all cases, the clinical signs disappeared or improved significantly. Conclusions: MODEL surgery increased mitral valve coaptation, normalized heart sizes, and significantly improved clinical signs in dogs with mitral regurgitation.

Institution representation in publications reporting mitral valve repair durability: A scoping review

BACKGROUND

Mitral valve repair durability currently plays a key role in operative decision making and in defining optimal surgical practice. However, mitral valve durability outcomes measures are not captured by national registries and limited to centers that publish their outcomes. In this study, we aim to describe the scope of institutions represented by reports describing durability outcomes after mitral valve repair within the contemporary literature.

METHODS AND RESULTS

A scoping review of the literature was performed to extract abstracts potentially reporting mitral valve operation outcomes published between 2000-2019. 370 full text articles reporting mitral valve durability outcomes by either reoperation rate or rate of recurrent mitral regurgitation met criteria for analysis. Study characteristics including case volume, country and institution of origin, and surgeon volume were extracted and used to calculate the proportion of total cases in the top 3, 5, and 10 represented countries and institutions by the sum of reported mitral valve repairs described. The top 5 of 21 countries represented 78.9% of the mitral valve repair cases described. The top 3 most represented institutions described 20,120 (37.3%) of all mitral valve repairs in 58 (33.9%) single-center studies.

CONCLUSION

Published mitral valve repair durability data must be interpreted with caution when used to derive policies and practice recommendations that govern the cardiovascular community at large.

The impact of transcatheter edge-to-edge repair on mitral valve annular geometry

PURPOSE OF REVIEW

Mitral valve transcatheter edge-to-edge repair (TEER) is becoming increasingly common to treat severe mitral regurgitation. However, the lack of concomitant annuloplasty raises concerns regarding its durability. As a result, there is an emerging body of literature evaluating the impacts of TEER on mitral annular geometry. In this review, we summarize the most recent literature evaluating the impacts of TEER on annular geometry in the acute, intermediate and long-term. We also review the relationship between changes in annular geometry and clinical endpoints.

RECENT FINDINGS

Current evidence suggests that TEER acutely induces favourable changes in mitral annular size and shape, which may persist for at least up to 1 year. Few studies suggest that TEER-induced annular remodelling is associated with positive clinical outcomes.

SUMMARY

The current body of literature is sparse and limited to primarily small case series. Data from the surgical literature suggest that ringless edge-to-edge repair is associated with eventual failure. Unfortunately, few studies evaluate TEER-induced annular changes beyond the acute postprocedural phase. Future research needs to focus on and evaluate the significance of TEER-induced changes in annular dimensions in the long-term.

Resurgence of the edge-to-edge repair of the mitral valve

PURPOSE OF REVIEW

To provide a critical review of the application and outcomes of surgical edge-to-edge (E2E) or Alfieri repair for mitral valvulopathy.

RECENT FINDINGS

The E2E repair is a surgical technique to address mitral regurgitation, particularly suited when the responsible mechanism is bileaflet prolapse combined with enlarged annular area. It can also be used for a range of mitral valve pathologies. Surgically, the technique has been employed as a bailout for unsuccessful repair including residual mitral regurgitation because of systolic anterior motion (SAM). E2E repair should be accompanied by a ring annuloplasty for long-term repair durability. The simplicity of this approach makes it an ideal strategy during minimally-invasive mitral valve repair. It may also be performed via a transaortic approach at the time of aortic valve surgery to address less-than-severe mitral regurgitation or to address residual SAM following myectomy for hypertrophic obstructive cardiomyopathy. We review the surgical indication, potential complications including risk of mitral stenosis and the long-term outcomes of E2E repair.

SUMMARY

The E2E surgical repair is a simple and effective surgical strategy to address a wide range of mitral regurgitation. This is an important technique in the surgical armamentarium especially in cases of minimally-invasive mitral valve surgery.

Transcatheter Repair of the Mitral Valve: Relevant Pathophysiology, Investigation, and Management

Mitral regurgitation (MR) is a common condition causing significant morbidity and mortality in the Western world. Although surgical therapy has developed over 5 decades to provide solutions, only a minority of patients undergo surgery. The last decade has seen the emergence and application of multiple transcatheter techniques in attempts to address this undertreated population with the large clinical experience of MitraClip providing the most insight. Clear understanding of the pathophysiology of different MR types as well as the role of particularly secondary MR on patient's clinical syndrome allow for better prediction as to which patient subgroups will benefit from different repair techniques or intervention at all. Most of the techniques are based on surgical technique and are applied as single-device/technique solutions, whether leaflet, chordal, or annular solutions, but with broadening experience, combination therapies are likely to find a place in creating a more complete and surgical-like solution.

Lessons from reoperations for mitral stenosis after mitral valve repair

BACKGROUND

The durability of mitral valve repair (MVr) is usually defined by the absence of recurrent significant mitral regurgitation. Postrepair mitral stenosis (MS) is a less frequent and less studied mode of failure of MVr. We analyzed our experience in patients who underwent reoperation for postrepair MS to characterize mechanisms resulting in MS and to summarize reoperative surgical strategies and mid-term outcomes.

METHODS

Using a prospective database, we retrospectively analyzed data on 35 consecutive patients who underwent reoperation for symptomatic moderate to severe MS between January 1, 2011, and February 1, 2020.

RESULTS

The mean patient age was 61.4 ± 11.4 years, and 69% were female. The median annuloplasty ring size used at the initial repair was 28 mm (interquartile range, 26-30 mm). Additional repair techniques at the initial operation included leaflet resection in 12 patients (34%) and commissuroplasty or edge-to-edge repair in 6 patients (18%). At reoperation, the most common mechanism of MS was pannus ingrowth in 20 patients (57%), leaflet calcification in 12 (34%), commissural fusion in 5 (14%), and tunnel effect (functional MS) in 3 (9%). Twenty-two patients (63%) underwent valve replacement, and 13 (37%) underwent valve re-repair. In patients who underwent re-repair, annuloplasty revision was performed in all patients, with 6 patients (46%) converted from complete ring to band, 4 (11%) converted from ring to pericardial annuloplasty, 2 (6%) converted to no annuloplasty, and 1 (8%) with annuloplasty ring upsizing. There were no in-hospital or 1-year mortalities. Survival at the 5-year follow-up was 93.9%.

CONCLUSIONS

MS causing late failure of MVr is frequently associated with smaller ring sizes and inflammatory or calcific changes in the valve. Highly selected patients may be good candidates for mitral valve re-repair.

Long-Term Results of Mitral Repair With Complete Semi-Rigid Rings vs Posterior Flexible Bands

BACKGROUND

The aim of the study was to evaluate whether the type of ring used had an impact on the long-term results of mitral repair for degenerative mitral regurgitation (MR), due to posterior leaflet prolapse, treated with quadrangular or triangular resection.

METHODS

From January 2002 to December 2008, 1406 patients with severe MR due to posterior leaflet prolapse underwent mitral repair. Of these patients, we selected 452 consecutive patients treated with the same repair approach. Mitral annuloplasty to complete the repair was performed with a posterior flexible band (n = 260) or a complete semi-rigid ring (n = 192). The 2 groups were comparable at baseline, and their clinical and echocardiographic outcomes were compared at long-term follow-up.

RESULTS

Overall survival at 14 years was similar (P = .29). The cumulative incidence function of cardiac death, with noncardiac death as competing risk, showed no difference (P = .71). At 14 years, probability of recurrence of MR greater than or equal to 3+ was 1.11% in the flexible band group and 3.25% in the semi-rigid ring group (P = .073). At 14 years, probability of recurrence of MR greater than or equal to 2 was 13.49% in the band group vs 10.78% in the semi-rigid ring group (P = .897).

CONCLUSIONS

In patients requiring mitral valve repair for posterior leaflet prolapse, treated with the same repair approach, the type of annuloplasty ring has no impact on the incidence of cardiac death and recurrence of MR at 14 years. Whether these findings remain stable at longer follow-up should be further investigated.

A novel system for the treatment of aortic annular dilation: an ex vivo investigation

OBJECTIVES

The main reason for aortic repair failures is recurrent annular dilatation. The fibrous portion of left ventricular outflow tract dilates. A novel device was designed to tackle this problem.

METHODS

The device consists of an internal ring applied at the aortic annulus plus an external flexible band at the level of the aortic root. The internal ring has a semi-rigid portion (40%, placed at ventriculo-arterial junction) and a flexible portion to allow it to conform along the curves of the non-coronary/right coronary leaflet and right coronary/left coronary leaflet commissures. The external band acts as a reinforcement to the internal ring. A pulsatile mock loop capable of housing porcine aortic valve was used. Working conditions were 60 bpm of heart rate, 75 of stroke volumes and 120-80 mmHg of simulated pressure. Mean gradient, effective orifice area, annular diameter, coaptation height and length were recorded on 11 aortic root units (ARUs). High-speed video and standard echocardiographic images were also recorded. All data were acquired in the following conditions: (i) basal (untreated ARU); (ii) pathological condition (left coronary/non-coronary triangle was dilated by suturing an aortic patch); and (iii) ARU treated with the device.

RESULTS

Gradients and effective orifice area were respectively 0.9 ± 0.64 mmHg and 3.1 ± 0.7cm2 (pathological) and 3.7 ± 1.1 mmHg and 1.5 ± 0.2cm2 (treated, P < 0.05). Left coronary/non-coronary diameter decreased from 2.4 ± 0.2 cm (pathological) to 2.0 ± 0.2 (treated, P < 0.05). Coaptation length and height were fully restored to basal values following treatment. Visual inspection showed proper dynamics of the leaflet, confirmed by high-speed video and echocardiography.

CONCLUSIONS

The device allowed for restoring physiologic-like coaptation in the experimental model, without inducing clinically relevant worsening of the haemodynamics of the treated ARU.

Computational virtual evaluation of the effect of annuloplasty ring shape

Mitral regurgitation (MR) is a result of mitral valve (MV) pathology. Its etiology can be categorized as degenerative or functional MR. Ring annuloplasty aims to reconfigure a dilated mitral annulus to its normal size and shape. We investigated the effect of annuloplasty ring shape on MR outcome using our established 3-dimensional (3-D) echocardiography-based computational MV evaluation protocols. Virtual patient MV models were created from 3-D transesophageal echocardiographic data in patients with MR because of mitral annular dilation. Two distinct annuloplasty rings (Physio II and GeoForm) were designed and virtually implanted to the patient MVs. Dynamic finite element simulations of MV function were performed for each MV after virtual ring annuloplasty of either ring, and physiologic and biomechanical characteristics of MV function were compared. Excessive stress values appeared primarily in the midanterior and midposterior regions, and lack of leaflet coaptation was found in pre-annuloplasty patient MVs. Both rings demonstrated marked reduction of stresses and efficient leaflet coaptation. The Physio II ring demonstrated more evenly distributed stress reduction across the leaflets and annulus compared with the GeoForm ring. Conversely, the highly nonplanar curvature of the GeoForm ring more effectively increased leaflet coaptation compared with the Physio II ring. This indicates that the shape of annuloplasty ring affects post-annuloplasty physiologic and biomechanical conditions, which can lead to tissue alteration over a longer period after ring annuloplasty. This virtual ring annuloplasty simulation strategy provides detailed physiologic and biomechanical information and may help better plan the optimal ring selection and improved patient-specific MV repairs.

Minimally Invasive Surgical Mitral Valve Repair: State of the Art Review

Minimally invasive surgical mitral valve repair (MVRepair) has become routine for the treatment of mitral valve regurgitation, and indications have been expanded to include reoperations. Current European Society of Cardiology/European Association for Cardio-Thoracic Surgery guidelines for the management of valvular heart disease recommended standards in terms of mitral valve disease differentiation, timing of intervention and surgical techniques to improve patient care. Numerous minimally invasive techniques to lessen the invasiveness have been described, such as the minimal-access J-sternotomy (ministernotomy), the parasternal incision, the port-access technique and the right minithoracotomy. Despite the development of catheter-based techniques, surgical repair remains the gold standard today for nearly all patients with degenerative valvular diseases and the majority of patients with other types of valvular diseases. Techniques include resection of the prolapsed segment, neo-chordae implantation and ring annuloplasty. In this review, the current indications for mitral valve surgery are summarised and state-of-the-art MVRepair techniques are highlighted.

Durability of mitral valve repair for mitral regurgitation due to degenerative mitral valve disease

Degenerative diseases of the mitral valve (MV) are the most common cause of mitral regurgitation in the Western world and the most suitable pathology for MV repair. Several studies have shown excellent long-term durability of MV repair for degenerative diseases. The best follow-up results are obtained with isolated prolapse of the posterior leaflet, however even with isolated prolapse of the anterior leaflet or prolapse of both leaflets the results are gratifying, particularly in young patients. The freedom from reoperation on the MV at 15 years exceeds 90% for isolated prolapse of the posterior leaflet and it is around 70-85% for prolapse of the anterior leaflet or both leaflets. The degree of degenerative change in the MV also plays a role in durability of MV repair. Most studies have used freedom from reoperation to assess durability of the repair but some studies that examined valve function late after surgery suggest that recurrent mitral regurgitation is higher than estimated by freedom from reoperation. We can conclude that MV repair for degenerative mitral regurgitation is associated with low probability of reoperation for up to two decades after surgery. However, almost one-third of the patients develop recurrent moderate or severe mitral regurgitation suggesting that surgery does not arrest the degenerative process.

Single-Center Experience With Adjustable Annuloplasty Ring in Degenerative Mitral Regurgitation

OBJECTIVE

Owing to the complex anatomy of the mitral valve, successful surgical repair of degenerative regurgitation remains a challenging procedure in cardiac surgery.

METHODS

This paper aimed to report on our single-center experience with 20 patients who received an adjustable annuloplasty ring (Cardinal ring, ValtechCardio Ltd, Or Yehuda, Israel) as part of their mitral valve repair procedure. The device allows for intraoperative echocardiography-guided ring size adjustments under beating-heart conditions.

RESULTS

All of the 20 patients left the operating room without any residual mitral regurgitation. There was no risk of systolic anterior movement (SAM) because of image-guided fine tuning of the ring before weaning the patient from bypass.

CONCLUSIONS

Further multicenter data are required to prove the concept of adjustable annuloplasty devices.

Lifting posterior mitral annuloplasty for enhancing leaflet coaptation in mitral valve repair: midterm outcomes

BACKGROUND

We evaluated the midterm outcomes of lifting posterior mitral annuloplasty for enhancing leaflet coaptation in mitral valve repair.

METHODS

Between October 2007 and December 2012, 341 consecutive patients with significant mitral regurgitation underwent lifting posterior mitral annuloplasty using a specially designed fabric annuloplasty strip that lifts the middle portion of the posterior annulus. Associated procedures for mitral valve repairs, such as patch valvuloplasty for posterior leaflet prolapse (n=80), new chord placement for anterior leaflet prolapse (n=33), commissurotomy (n=29), and posterior leaflet extension (n=23), were performed in 141 patients (41.3%).

RESULTS

Thirty-day mortality was 0.9%. Nine late deaths (2.6%) occurred. Mean overall survival at 5 years was 96.0%±1.1%. During the mean follow-up period of 38±17 months, six patients (1.8%) underwent valve-related reoperation (5-year freedom from valve-related reoperation, 98.1%±0.8%). At 5 years, mean freedom from recurrence of mitral regurgitation grade 3+ to 4+ (moderate to severe) was 95.1%±1.6%. The mean valve pressure gradient (PG) was 3.2±1.5 mmHg across all strip sizes at the time of follow-up.

CONCLUSIONS

Lifting posterior mitral annuloplasty using an innovative annuloplasty strip in mitral valve repair has a low rate of recurrent regurgitation or valve-related reoperation with rare relevant complications.

A novel finite element-based patient-specific mitral valve repair: virtual ring annuloplasty

Alterations of normal mitral valve (MV) function lead to mitral insufficiency, i.e., mitral regurgitation (MR). Mitral repair is the most popular and most efficient surgical intervention for MR treatment. An annuloplasty ring is implanted following complex reconstructive MV repairs to prevent potential reoccurrence of MR. We have developed a novel finite element (FE)-based simulation protocol to perform patient-specific virtual ring annuloplasty following the standard clinical guideline procedure. A virtual MV was created using 3D echocardiographic data in a patient with mitral annular dilation. Proper type and size of the ring were determined in consideration of the MV apparatus geometry. The ring was positioned over the patient MV model and annuloplasty was simulated. Dynamic simulation of MV function across the complete cardiac cycle was performed. Virtual patient-specific annuloplasty simulation well demonstrated morphologic information of the MV apparatus before and after ring implantation. Dynamic simulation of MV function following ring annuloplasty demonstrated markedly reduced stress distribution across the MV leaflets and annulus as well as restored leaflet coaptation compared to pre-annuloplasty. This novel FE-based patient-specific MV repair simulation technique provides quantitative information of functional improvement following ring annuloplasty. Virtual MV repair strategy may effectively evaluate and predict interventional treatment for MV pathology.

Minimally invasive mitral valve surgery: "The Leipzig experience"

BACKGROUND

Minimally invasive mitral valve surgery has become a routine procedure at our institution. The present study analyzed the early and long-term outcomes of patients undergoing minimally invasive mitral valve surgery over the last decade, with special focus on mitral valve repairs (MVRp).

METHODS

The preoperative variables, intraoperative data and postoperative outcomes of patients undergoing minimally invasive mitral valve surgery were prospectively collected in our database from May 1999 to December 2010. The survival and freedom from reoperation were evaluated with life tables and Kaplan-Meier analyses.

RESULTS

A total of 3,438 patients underwent minimally invasive mitral valve surgery, of which 2,829 were MVRps and 609 were mitral valve replacements (MVR). Forty-five patients (1.6%) required MVR due to failure of repair. The mean age was 60.3±13 years. More than a third of patients underwent concomitant procedures like tricuspid valve surgery, atrial septal defect (ASD) closure and cryoablation. The rate of conversion to sternotomy was less than 1.4%. The 30-day mortality was 0.8%. The 5- and 10-year survival of all patients (MVR and MVRp) undergoing minimally invasive mitral valve surgery was 85.7±0.6% and 71.5±1.2%, respectively. For MVRp, the survival was 87.0±0.7% and 74.2±1.4% at 5 and 10 years, respectively. Freedom from reoperation was 96.6±0.4% and 92.9±0.9% at 5 and 10 years, respectively.

CONCLUSIONS

Minimally invasive MVRp can be performed safely and effectively with very few perioperative complications. The early and long-term outcomes in these patients are acceptable.

Late Outcomes of Mitral Valve Repair for Mitral Regurgitation Due to Degenerative Disease

Background—

The pathological spectrum of degenerative diseases of the mitral valve (MV) that causes mitral regurgitation (MR) is broad, and there is limited information on late outcomes of MV repair in various subgroups of patients and pathologies. This study examines this issue.

Methods and Results—

All 840 patients who had MV repair for MR due to degenerative diseases from 1985 to 2004 were prospectively followed with clinical and echocardiographic evaluations at biennial intervals up to 26 years, median of 10.4 years. Clinical, hemodynamic, and pathological variables were evaluated for their association with outcomes. Age, left ventricular ejection fraction, and functional class were predictors of late cardiac- and valve-related deaths by multivariable analysis. MV repair failed to restore life span to normal in patients with functional class IV. Thirty-eight patients had repeat MV surgery, and the probability of reoperation at 20 years was 5.9%. During the follow-up, recurrent severe MR developed in 37 patients, and moderate MR developed in 61. Age, isolated prolapse of the anterior leaflet, the degree of myxomatous changes in the MV, lack of mitral annuloplasty, and duration of cardiopulmonary bypass were associated with increased risk of recurrent MR. At 20 years, the freedom from recurrent severe MR was 90.7%, and the freedom from moderate or severe MR was 69.2%.

Conclusions—

MV repair for degenerative MR restored life span to normal except in patients with symptoms at rest and impaired left ventricular function. Advanced age and complex mitral valve pathologies increased the risk of late recurrent MR.

Mitral valve repair under cardiopulmonary bypass in small-breed dogs: 48 cases (2006-2009)

OBJECTIVE

To determine whether mitral valve repair (MVR) under cardiopulmonary bypass would be an effective treatment for mitral regurgitation in small-breed dogs.

DESIGN

Retrospective case series.

ANIMALS

48 small-breed dogs (body weight, 1.88 to 4.65 kg [4.11 to 10.25 lb]; age, 5 to 15 years) with mitral regurgitation that underwent surgery between August 2006 and August 2009.

PROCEDURES

Cardiopulmonary bypass was performed with a cardiopulmonary bypass circuit. After induction of cardiac arrest, a mitral annuloplasty was performed, and the chordae tendineae were replaced with expanded polytetrafluoroethylene chordal prostheses. After closure of the left atrium and declamping to restart the heart, the thorax was closed.

RESULTS

Preoperatively, cardiac murmur was grade 3 of 6 to 6 of 6, thoracic radiography showed cardiac enlargement (median vertebral heart size, 12.0 vertebrae; range, 9.5 to 14.5 vertebrae), and echocardiography showed severe mitral regurgitation and left atrial enlargement (median left atrium-to-aortic root ratio, 2.6; range, 1.7 to 4.0). 45 of 48 dogs survived to discharge. Three months after surgery, cardiac murmur grade was reduced to 0/6 to 3/6, and the heart shadow was reduced (median vertebral heart size, 11.1 vertebrae, range, 9.2 to 13.0 vertebrae) on thoracic radiographs. Echocardiography confirmed a marked reduction in mitral regurgitation and left atrium-to-aortic root ratio (median, 1.7; range, 1.0 to 3.0).

CONCLUSIONS AND CLINICAL RELEVANCE

We successfully performed MVR under cardiopulmonary bypass in small-breed dogs, suggesting this may be an effective surgical treatment for dogs with mitral regurgitation. Mitral valve repair with cardiopulmonary bypass can be beneficial for the treatment of mitral regurgitation in small-breed dogs.

Time-dependent change in fresh autologous pericardium applied for posterior mitral annuloplasty: degree of calcification and its influence on the repaired mitral valve

OBJECTIVE

To investigate the degree of calcification of fresh autologous pericardium applied for posterior mitral annuloplasty and its influence on the repaired mitral valve.

METHODS

Thirty-nine patients (31 degenerative and 8 infective endocarditis; mean age at surgery: 62 ± 11 years) were enrolled in this study. Sixteen-slice multi-detector computed tomography was performed to identify calcification of autologous pericardium. The mean clinical follow-up was 4.6 ± 2.6 years (maximum 8.8 years) and the mean computed tomography follow-up period was 3.6 ± 2.5 years (maximum 7.6 years) after surgery.

RESULTS

Pericardial calcification was detected in 15 patients. The earliest detection of calcification was 2.5 years after surgery. There was a weak correlation between pericardial calcification and postoperative years (Pearson's product correlation coefficient: 0.476; p = 0.0019). However, severe calcification of autologous pericardium did not occur in any case. There was no association between pericardial calcification and recurrent mitral regurgitation (p = 0.1145). The mean mitral valve orifice area and the mean transmitral pressure gradient in the 15 patients with calcification were 3.0 ± 0.6 cm(2) and 2.1 ± 1.0 mmHg, respectively.

CONCLUSIONS

Calcification of the fresh autologous pericardium increased with postoperative years. It had no adverse effects on repaired mitral valve in the short-term follow-up period. We will report the findings once again when the follow-up reaches 10 years.

Mitral valve repair in dogs

Prognosis for dogs with severe mitral regurgitation is poor with medical therapy alone. Open surgical mitral valve repair consisting of circumferential mitral annuloplasty and artificial chordal replacement confers durability and improved long-term clinical outcome without a need for long-term antithrombotic therapies. This approach has been successfully used in canine patients, including small-breed dogs. Methods for mitral valve repair applicable to small dogs are described.

Local suture annuloplasty for posterior mitral valve repair: 18-year experience

We retrospectively reviewed 128 consecutive patients who underwent quadrangular resection of a prolapsed posterior mitral leaflet and local suture annuloplasty. The median age was 68.1 ± 10.0 years (range, 30-84 years) and 63.3% were male. Mean left ventricular ejection fraction was 63.8% ± 10.2% (range, 25%-80%). The etiology of mitral regurgitation was fibroelastic degeneration in 94 (73.4%) patients, myxomatous degeneration in 26 (20.3%), myxomatous infective endocarditis in 7 (5.5%), and post-infarction papillary rupture in one. There was 1 (0.8%) hospital death. The median follow-up was 4.7 ± 4.7 years (range, 0.01-18.29 years). The freedom from reoperation was 98%, 94%, 87%, and 79% at 1, 5, 10, and 15 years, respectively, improving for the most recent 107 patients, subsequent to technical modification, to: 100%, 96%, 94%, and 90% at 1, 5, 10, and 14 years, respectively. Ten- and 15-year freedom from severe mitral regurgitation was 91%, and 88%, respectively. The overall actuarial 1-, 5-, 10-, and 15-year survival rates were 98%, 90%, 70%, and 52%, respectively, similar to that of the age- and sex-matched United Kingdom population. The long-term results of this technique in selected patients with prolapsed posterior leaflet were considered acceptable.

Repair for mitral stenosis due to pannus formation after Duran ring annuloplasty

Mitral stenosis after mitral repair with using an annuloplasty ring is not common and it is almost always due to pannus formation. Mitral valve replacement was required in most of the previous cases of pannus covering the mitral valve leaflet, which could not be stripped off without damaging the valve leaflets. In two cases, we removed the previous annuloplasty ring and pannus without leaflet injury, and we successfully repaired the mitral valve. During the follow-up of 4 months and 39 months respectively, we observed improvement of the patients' symptoms and good valvular function. Redo mitral repair may be a possible method for treating mitral stenosis due to pannus formation after ring annuloplasty.

Annuloplasty ring removal from patients with hemolysis after mitral valve repair

We present a case of severe hemolysis following a mitral valve repair, which was successfully treated by removing the annuloplasty ring. The etiology of the hemolysis appeared to be a small regurgitant jet at the level of the annuloplasty ring.

Robot-Assisted Mitral Valve Repair a Single Institution Review

Objective

Mitral valve repair (MVR) is the definitive therapy for mitral myxomatous degeneration. Median sternotomy has been the traditional approach to repair until the advent of the da Vinci Surgical System (Intuitive Surgical, Inc., Sunnyvale, CA). Minimally invasive surgical approaches for mitral repair have been slow to gain acceptance in cardiac surgery. We review the MVR results from our single-institution academic robotic program.

Methods

From August 2004 through April 2008, patients who underwent a robotic-assisted (RA) MVR were identified. RA technique included a 4-cm right minithoracotomy, femoral cardiopulmonary bypass with transthoracic aortic occlusion, and RA-MVR. Repair types were combinations of quadrangular/triangular leaflet resection, sliding plasty, chordal transfer/replacement, and edge-to-edge approximation, with band annuloplasty in all cases. Postrepair echocardiography and morbidity follow-ups were completed in all patients. Our primary outcome was adequacy of repair, and secondary outcome was major complications.

Results

There were 43 patients (29 male and 14 female) who underwent RA-MVR for severe (4 +) mitral regurgitation during the 4-year review. Average operative time was 272.26 minutes. Only one patient had mild postoperative mitral regurgitation, whereas 20 had trace and 22 had no regurgitation after repair. Mean ventilator time was 32.1 hours, and length of stay was 5.7 days. One third of the patients (33%) received postoperative-packed red blood cell transfusions (average: 2.4 units per patient). Twenty-eight percent of patients developed atrial fibrillation after repair. Most of the patients (95.3%) were discharged home. There were no 30-day mortalities.

Conclusions

Based on our small single-institution experience, RA-MVR provides an effective treatment for severe mitral valve regurgitation. Although procedure durability is slowly being established, preliminary results are promising. Careful programmatic advances with an integrated team approach can facilitate acceptable postoperative outcomes and excellent MVR.

Combined mitral and tricuspid valve repair in rheumatic valve disease: fewer reoperations with prosthetic ring annuloplasty

BACKGROUND

We examined predictors of early and very long-term outcome after combined mitral and tricuspid valve repair for rheumatic disease.

METHODS AND RESULTS

Between 1974 and 2002, 153 consecutive patients (mean age, 46.0+/-13.2 years) underwent combined mitral and tricuspid valve repair for rheumatic disease. Mitral disease was predominantly stenosis (82.3%); 100% of patients had organic tricuspid valve disease, predominantly with regurgitation (53.6%) or some degree of tricuspid stenosis (46.4%). Mitral repair included commissurotomy in 132 patients (86.3%) associated with a flexible annuloplasty in 108. Tricuspid valve repair included flexible annuloplasty in 68 patients (44.4%) and suture annuloplasty in 20 patients (13.1%) combined with tricuspid commissurotomy in 62 patients (42.5%). Thirty-day mortality was 5.9%. Late mortality was 60.1%. The median follow-up was 15.8 years (interquartile range, 6 to 19 years). Follow-up was 97.9% complete. Age>65 years was the only predictor of late mortality. Kaplan-Meier survival probability was 74.4% at 10 years and 57.0% at 15 years. Sixty-three patients required valve reoperation (mitral valve, 59; tricuspid valve, 38). Predictors of valve reoperations were either mitral or tricuspid commissurotomy without associated prosthetic ring annuloplasty. At 20 years, Kaplan-Meier freedom from reoperation was 48.5+/-5.1%.

CONCLUSIONS

Combined mitral and tricuspid valve repair in rheumatic disease showed satisfactory early results. Long-term results were poor because of high mortality and a high number of valve-related reoperations. The use of prosthetic ring annuloplasty was significantly associated with a reduced incidence of both mitral and tricuspid valve reoperations.