Mitral-valve repair without annuloplasty rings: results after repair of anterior leaflet versus posterior-leaflet defects using polytetrafluoroethylene sutures for chordal replacement

Trends in the Management of Anterior Mitral Leaflet Regurgitation

Importance

The overall prevalence of mitral valve replacement (MVR) or MV repair at the time of cardiac surgery in the setting of isolated anterior mitral leaflet degenerative pathologic status in the US population is unknown.

Objective

To investigate the prevalence of MVR and MV repair using the Society of Thoracic Surgeons' Adult Cardiac Surgery Database.

Design, Setting, and Participants

In a cross-sectional study, all patients diagnosed with isolated anterior mitral leaflet degenerative regurgitation who underwent either surgical MVR or MV repair between July 1, 2011, and June 30, 2022, were identified. Linear regression analysis was used to assess trends over time.

Main Outcomes and Measures

Assessment of the trends in MV repair and MVR over time.

Results

A total of 16 259 patients (9624 [59.2%] men) were identified, and the median age was 68 (IQR, 58-74) years. A total of 7214 patients (44.4%) had MVR, and 9045 (55.6%) had MV repair. There was a declining trend of MV repair from 58.0% in 2011 to 51.6% in 2022 (P = .05). The MVR group was older (median [IQR] age, 70 [62-77] vs 67 [58-74] years; P < .001) and had more comorbidities. A total of 85.1% of all patients underwent concomitant procedures. In 81.7% of MVR cases, no attempt at MV repair was made. The median (IQR) annual hospital volume was lower with MVR vs MV repair (2.50 [1.50-5.00] vs 4.00 [2.00-7.00]; P < .001). Conventional surgical approaches were most common (91.5%) but with a declining trend (P < .001). Minimally invasive approaches were used in 13.1% (robotic, 4.6%), and with an inclining trend from 5.0% in 2011 to 12.0% in 2022 (P < .001). Annuloplasty was performed in 88.8% of MV repair cases. Its use as a sole mean of MV repair decreased from 48.0% in 2011 to 13.9% in 2022 (P < .001). Repair maneuvers in addition to annuloplasty were neochordae (overall 40.1%, increasing from 22.5% in 2011 to 62.3% in 2022; P < .001), leaflet resection (overall 10.2%, decreasing from 13.1% in 2011 to 7.9% in 2022, P = .002), edge-to-edge MV repair (overall 5.3%, decreasing from 6.9% in 2011 to 4.5% in 2022; P = 0.04), and chordal transfer (overall 2.4%, decreasing from 2.7% in 2011 to 0.7% in 2022; P = .004).

Conclusions and Relevance

In this cross-sectional study, MV repair was the preferred option for degenerative mitral valve disease but was only slightly more commonly performed than MVR for isolated anterior leaflet pathologic status. A large proportion of MVR was performed without an MV repair attempt, suggesting reluctance to repair this pathologic condition.

Outcomes of transapical mitral valve repair with neochordae implantation

OBJECTIVE

Transapical off-pump beating-heart neochord implantation (NC) has shown encouraging early results in patients with degenerative mitral regurgitation. The aim of this study was to evaluate clinical and echocardiographic 5-year outcomes of patients who underwent NC.

METHODS

All patients who underwent NC at our institution from November 2013 to March 2016 were included. Indications were severe symptomatic degenerative mitral regurgitation due to leaflet prolapse/flail. Patients were classified as having favorable anatomy (FA) and unfavorable anatomy (UA) on the basis of the extent and severity of mitral valve disease. All patients underwent clinical and echocardiographic follow-up at 1, 3, 6, and 12 months, and annually thereafter. Data were prospectively collected and retrospectively analyzed. Outcomes were on the basis of the Mitral Valve Academic Research Consortium guidelines.

RESULTS

One hundred consecutive patients were included in the analysis (FA: 81%; UA: 19%). Median age was 66 years (interquartile range, 58-76) and median European System for Cardiac Operative Risk Evaluation (EuroSCORE) II was 1.4% (interquartile range, 0.7-2.3). Technical and procedural success were 98% and 94%, respectively. Thirty-day mortality was 2%. Device success was 94%, 92%, and 78%, at 30 days, 1-year, and 5 years, respectively. Patient success at 1 year was 92%. Median follow-up was 5.1 years. At 5 years, overall survival was 83% with no difference between FA and UA patients. Cumulative incidence of severe mitral regurgitation recurrence at 5 years was 14% (95% CI, 6.5%-22.8%) in FA patients and 63% (95% CI, 39.7%-86.2%) in UA patients, respectively (P < .001). Patients with FA compared with UA had a lower incidence of reintervention (14.7% vs 43.4%; P < .001).

CONCLUSIONS

Transapical off-pump beating heart NC might represent an acceptable option in patients with degenerative mitral valve disease and FA.

Comparison of meta-analytical estimates of outcomes after Alfieri or neochordal repair in isolated anterior mitral prolapse

OBJECTIVES

Repair of the isolated degenerative anterior mitral leaflet has been considered more challenging and associated with compromised durability compared with isolated posterior leaflet in major series. Implantation of neochordae or Alfieri edge-to-edge is the most employed repair technique for isolated anterior repair currently, but little data exist comparing their relative durability. We sought to investigate this issue with this meta-analysis.

METHODS

A literature search was performed (Ovid MEDLINE, Ovid Embase and The Cochrane Library). The primary outcome was the incidence rate (IR) of reoperation, the secondary outcomes were recurrent moderately severe/severe mitral regurgitation (MR), in-hospital/30-day reoperation and mortality and follow-up mortality. A random-effect model was used. Leave-one-out, subgroup analysis (Alfieri versus neochordae) and meta-regression were done.

RESULTS

Seventeen studies (including 1358 patients) were included. At a weighted mean follow-up of 5.56 ± 3.31 years, the IR for reoperation was 14.45 event per 1000 person-year and significantly lower in Alfieri than neochordae repair (9.40 vs 18.61, P = 0.04) on subgroup analysis. The IR of follow-up moderately severe/severe MR was 19.89 event per 1000 person-year and significantly lower in Alfieri than neochordae repair (10.68 and 28.63, P = 0.01). In a sensitivity analysis comparing homogenous studies, a significant difference in the recurrence of regurgitation in favour of the Alfieri approach remained. There were no differences in operative outcomes or survival. There were significant associations between increased incidence of late reoperation and New York Heart Association class III/IV and associated coronary artery bypass graft procedure for whole cohort.

CONCLUSIONS

Alfieri repair may be associated with a lower incidence of recurrent MR compared with neochordae-based repair in the setting of isolated degenerative anterior mitral pathology. This is the first such meta-analysis and further inquiry into this area is needed.

A new technique to adjust the length of artificial chordae during mitral anterior leaflet repair

BACKGROUND

Length measurement of artificial chordae remains a critical step during mitral valve repair (MVr). The aim of this study is to assess the effectiveness of a new length measuring technique.

METHODS

All consecutive patients with anterior leaflet prolapse/flail who underwent MVr using the described method between January 2020 and January 2022 at our institution were included in the analysis. Clinical and transesophageal echocardiography data were collected postoperatively and at 1-year follow-up. The primary outcome was freedom from mitral regurgitation (MR). Secondary outcomes were presentation with New York Heart Association (NYHA) class <2 and leaflet coaptation length ≥10 mm.

RESULTS

Of 25 patients, 16 (64%) were males. A total of 15 (60%) had isolated anterior leaflet disease, while 10 (40%) had concomitant posterior involvement. Twenty patients with isolated MR (80%) underwent right anterior mini-thoracotomy, while 5 (20%) with associated valvular or coronary disease underwent sternotomy. The median number of chordae implanted was 2 [1-4]. Postrepair intraoperative MR grade was 0 in 23 patients (92%) and 1 in 2 (8%). Thirty-day mortality was 0%. De novo atrial fibrillation was 20%. At follow-up, mortality was 0%. No patients presented with moderate or severe MR. A total of 22 patients (88%) were in NYHA class I, while 3 (12%) in class II. The coaptation length was 11 ± 1 mm.

CONCLUSIONS

The short-term outcomes of the described technique are good with adequate leaflet coaptation in all treated patients. Long-term results are needed to assess the stability and durability of this repair technique.

Anterior versus posterior leaflet mitral valve repair: A propensity-matched analysis

OBJECTIVE

Mitral valve repair is superior to replacement for degenerative disease, but long-term outcomes of anterior versus posterior leaflet repair remain poorly defined. We propensity matched anterior and posterior repairs to compare long-term outcomes.

METHODS

Patients undergoing first-time degenerative mitral repair between 1992 and 2018 were identified. Primary outcome was overall survival. Secondary outcomes were postprocedural residual mitral regurgitation and reoperation. From 1025 patients, 1:1 propensity score matching was performed, yielding 309 anterior (isolated anterior = 85, bileaflet = 224) and 309 isolated posterior repairs.

RESULTS

Age was 58 ± 15 years, ejection fraction was 57% ± 10%, and matched groups were well balanced. Anterior repairs had longer bypass (122 ± 53 vs 109 ± 43 minutes, P = .001) and crossclamp (94 ± 44 vs 85 ± 62 minutes, P = .033) times. Mean residual mitral regurgitation grade was 0.44 (95% confidence interval, 0.24-0.65) for anterior repair and 0.30 (95% confidence interval, 0.13-0.47) for posterior repair (P = .31). Overall, 92% (569/618) of matched patients had no residual mitral regurgitation, with no differences in mitral regurgitation grade between groups (P = .77). Survival did not differ between anterior (10 years: 72% ± 7%; 15 years: 63% ± 7%) and posterior (10 years: 74% ± 7%; 15 years: 60% ± 8%) groups (log-rank P = .93). Linearized incidence of reoperation was 0.62% per patient-year, including 0.74% for anterior and 0.48% for posterior repairs. Cumulative incidence of reoperation at 15 years was 7.5% after anterior repair and 4.9% after posterior repair (Gray's test P = .26).

CONCLUSIONS

No long-term survival or reoperation difference was found between posterior and anterior repair. On the basis of these findings, surgeons at centers of excellence should aim for repair of both anterior and posterior leaflet pathology with the same decision-making threshold over valve replacement for degenerative mitral disease.

Mitral chordae tendineae force profile characterization using a posterior ventricular anchoring neochordal repair model for mitral regurgitation in a three-dimensional-printed ex vivo left heart simulator

OBJECTIVES

Posterior ventricular anchoring neochordal (PVAN) repair is a non-resectional technique for correcting mitral regurgitation (MR) due to posterior leaflet prolapse, utilizing a single suture anchored in the myocardium behind the leaflet. This technique has demonstrated clinical efficacy, although a theoretical limitation is stability of the anchoring suture. We hypothesize that the PVAN suture positions the leaflet for coaptation, after which forces are distributed evenly with low repair suture forces.

METHODS

Porcine mitral valves were mounted in a 3-dimensional-printed heart simulator and chordal forces, haemodynamics and echocardiography were collected at baseline, after inducing MR by severing chordae, and after PVAN repair. Repair suture forces were measured with a force-sensing post positioned to mimic in vivo suture placement. Forces required to pull the myocardial suture free were also determined.

RESULTS

Relative primary and secondary chordae forces on both leaflets were elevated during prolapse (P < 0.05). PVAN repair eliminated MR in all valves and normalized chordae forces to baseline levels on anterior primary (0.37 ± 0.23 to 0.22 ± 0.09 N, P < 0.05), posterior primary (0.62 ± 0.37 to 0.14 ± 0.05 N, P = 0.001), anterior secondary (1.48 ± 0.52 to 0.85 ± 0.43 N, P < 0.001) and posterior secondary chordae (1.42 ± 0.69 to 0.59 ± 0.17 N, P = 0.005). Repair suture forces were minimal, even compared to normal primary chordae forces (0.08 ± 0.04 vs 0.19 ± 0.08 N, P = 0.002), and were 90 times smaller than maximum forces tolerated by the myocardium (0.08 ± 0.04 vs 6.9 ± 1.3 N, P < 0.001).

DISCUSSION

PVAN repair eliminates MR by positioning the posterior leaflet for coaptation, distributing forces throughout the valve. Given extremely low measured forces, the strength of the repair suture and the myocardium is not a limitation.

Review of transapical off-pump mitral valve intervention with NeoChord implantation

PURPOSE OF REVIEW

Mitral valve repair surgery has recently shifted from resection-based techniques to leaflet sparing approaches using synthetic neochordae. This has facilitated the growth of a new strategy of transapical off-pump mitral valve intervention with neochord implantation.

RECENT FINDINGS

Minimally invasive approaches for mitral valve repair with robotic or video-assisted mini-right anterolateral thoracotomy have been developed to mitigate the morbidity associated with conventional median sternotomy. Recently, an alternative, less invasive surgical strategy has emerged. This transapical off-pump technique employs the NeoChord DS1000 (NeoChord, Inc., Minneapolis, MN, USA) system to achieve repair with neochordae via a left minithoracotomy incision. With appropriate patient selection, advanced cardiac imaging, and training in device deployment are important for procedural success.

SUMMARY

Early results suggest that transapical off-pump mitral valve intervention with NeoChord implantation is a safe procedure with favorable outcomes for select patients with degenerative mitral regurgitation. Continued experience and clinical trials will assess the potential of this minimally invasive strategy, but this technique is likely to become part of the surgical repertoire for managing chronic degenerative mitral valve disease.

Mitral Valve Repair: Is There Still a Place for Suture Annuloplasty?

Prosthetic ring annuloplasty is considered the gold standard technique for mitral valve repair, but it has been associated with some drawbacks. Suture annuloplasty is less expensive and may have some physiopathologic advantages. We reviewed the literature to assess clinical results of mitral suture annuloplasty. Thirteen series, each reporting more than 50 patients and published in the last 10 years, were included in the analysis. They comprised 1,648 patients with cumulative follow-up of 5,607 patient-years. Our review suggests that suture annuloplasty is a safe procedure, but a trend toward recurrence of annular dilatation with time was reported. In selected cases, suture annuloplasty is effective, and its mid-term clinical results are encouraging and compare well with those of prosthetic ring repair series. The quality of the results varies according to the particular annuloplasty technique used and to the mitral valve pathology treated. Recent technical modifications have been found to decrease the incidence of repair failure and promise to improve the reproducibility of the procedure. Further investigations are warranted to better assess the long-term results of suture annuloplasty, and to determine whether its theoretical functional advantages translate into a real clinical benefit.

Outcomes of mitral valve repair using artificial chordae

OBJECTIVES

The use of artificial chordae techniques has increased the number of mitral valve lesions which are amenable to repair. Artificial chordae can be adapted for a wide range of mitral valve pathologies including restricting the motion of overly mobile 'floppy' Barlow disease leaflets, replacing diseased chordae and improving coaptation in degenerative disease. There is continuing concern about the long-term performance of artificial chordae, which become endothelialized over time and may exhibit complications during the early or late follow-up period.

METHODS

To address these issues, we reviewed the literature and extracted 17 papers reporting outcomes following artificial chordae replacement. We discuss the evidence of the effect of artificial chordae on mortality, morbidity and valve performance as measured by echocardiography and complications related to the chordae. We discuss in detail studies comparing artificial chordae with more widely used quadrangular resection techniques.

RESULTS

In general, outcomes with respect to mortality, morbidity, rates of reoperation, long-term function and complications of artificial chordae implantation are excellent in a range of pathological settings and in both children and adults. These results are comparable with classical Carpentier techniques and there is some evidence that chordal replacement techniques can in some respects improve the risk-benefit ratio for outcomes compared with the classical Carpentier techniques.

CONCLUSIONS

A number of problems remain in the use of artificial chordae, especially the proper determination of their length. Techniques that solve these issues may enhance patient outcomes further.

A good surgical option for ischemic mitral regurgitation in co-morbid patients: semicircular reduction annuloplasty

BACKGROUND

Ring annuloplasty is the standard treatment of ischemic mitral regurgitation (MR), however, it has been associated with some drawbacks. It abolishes normal annular dynamics and freezes the posterior leaflet. In the present study, we evaluated Paneth suture annuloplasty in chronic ischemic MR and both early and mid-term outcomes of the technique on a selected population.

METHODS

The study period was from June 2010 to June 2012. We operated on 21 patients who had the diagnosis of coronary artery disease and MR of grade 3 or 4. The patients had both a coronary artery bypass operation and the mitral semicircular reduction annuloplasty described by Paneth-Burr. The data on the patients were retrospectively collected. Patients were contacted by outpatient clinic controls for mid-term results.

RESULTS

The male/female ratio was 10/11. The mean age of the patients was 71.0 ± 6.4 years. Preoperative and postoperative left ventricular ejection fraction was statistically similar (P = 0.973). Early postoperative MR grade (mean, 0.57 ± 0.51) was statistically lower than the preoperative MR grades (mean, 3.38 ± 0.50) (P < 0.001). There was no revision for excess bleeding. Two patients had prolonged hospitalization, one for sternal infection and the other for severe chronic obstructive pulmonary disease. No hospital or late postoperative deaths occurred. The mean late postoperative MR grade was 0.66 ± 0.97 degrees. One patient had progression of MR in the later follow-up, which was treated by mitral valve replacement.

CONCLUSION

Semicircular reduction annuloplasty is an effective, inexpensive and easy surgical annuloplasty technique with low mortality and morbidity in severe symptomatic ischemic 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.

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.

Increasing Mitral Valve Repair Rates with Nonresectional Techniques

In every common mitral pathology studied to date, repairing the patient's own diseased valve to adequate function has yielded superior long-term results as compared with prosthetic valve replacement with either tissue or mechanical devices. Thus, increasing rates of mitral repair across all valve pathologies would seem to be a logical clinical goal. Techniques for mitral valve repair have undergone continual evolution over the past 50 years. Recently, emphasis has been placed on preserving leaflet surface area and avoiding tissue resection, by combining the methods of Gore-Tex artificial chordal replacement, autologous pericardial leaflet augmentation, and full ring annuloplasty. Using combinations of these three techniques appropriate to the given valve pathology, acute mitral repair rates now are approximating 98% for all common mitral disease etiologies. Simultaneously, operative mortalities for mitral repair have fallen significantly and now are negligible, whereas long-term outcomes using these methods have been increasingly more stable. As a result of innovations from multiple sources, mitral valve surgery has been converted from a higher risk procedure to one of the safest operations in most centers. This review will detail the technical application of “nonresectional” mitral repair approaches to a broad range of mitral disease pathologies.

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.

Severe haemolytic anaemia after valvuloplasty and annuloplasty

Haemolytic anaemia is a well-recognised but rare complication of heart-valve prostheses. The authors report a case of an 80-year-old woman with severe haemolytic anaemia previously treated with valvuloplasty and annuloplasty without rings. To our knowledge, no cases of haemolysis have been described with this type of surgery.

Chordal replacement in mitral repair

Chordal replacement has been a tool in mitral repair for two decades and is a particularly suitable option for the treatment of anterior mitral leaflet (AML) prolapse. Chordal replacement has also become an alternative to more conventional techniques in posterior leaflet prolapse. It has proven to be safe and durable, and the mid- to long-term results in AML repair are approaching those achieved by conventional repair of the posterior leaflet.

Influence of involvement of anterior leaflet versus posterior leaflet on residual regurgitation as assessed by transesophageal echocardiography in patients undergoing valve repair for mitral regurgitation due to mitral valve prolapse

Background

Repair of anterior leaflet prolapse is technically more challenging and this might influence outcomes as compared to the repair of posterior leaflet prolapse in patients undergoing surgical correction of mitral regurgitation. We investigated the association of anterior leaflet prolapse with minor residual mitral regurgitation (MR) in patients with mitral valve prolapse (MVP) who underwent valve repair.

Methods

Eligible for this study were consecutive patients with severe MR due to MVP, who underwent mitral valve repair with residual MR by postpump transesophageal echocardiography ≤2+ during a 20-month period at Pasquinucci Hospital, Massa. Patients undergoing other cardiovascular surgical interventions were excluded. Two groups were defined according to the involvement of mitral valve leaflets: group 1, consisting of patients with anterior leaflet prolapse (isolated or not); and group 2, consisting of patients with isolated posterior leaflet prolapse.

Results

A total of 70 patients (18 in group 1 and 52 in group 2) were analyzed. Patients in group 2 were younger than those in group 1, but the difference was not significant (P = 0.052). There were no significant differences between the 2 study groups with respect to other variables. The proportion of patients with residual MR 1+/2+ was higher in group 1 than in group 2 (61.1% vs. 32.7%, respectively; P = 0.034). In a logistic regression model, anterior leaflet prolapse was an independent predictor of residual MR 1+/2+ (odds ratio, 4.0; 95% confidence interval, 1.14 to 14.04; P = 0.03).

Conclusion

In our study population, patients with anterior leaflet prolapse had a higher proportion of residual MR 1+/2+ as compared to those with posterior leaflet prolapse after repair of mitral valve.

Robotic Artificial Chordal Replacement for Repair of Mitral Valve Prolapse

Artificial chordal replacement (ACR) has emerged as a superior method of mitral valve repair with excellent early and late efficacy. It is also ideal to combine with robotic techniques for correction of mitral prolapse, and this article presents a current method of robotic Gore-Tex ACR. Patients with isolated posterior leaflet prolapse are approached with the fourth-generation DaVinci robotic system and endoaortic balloon occlusion. A pledgetted anchor stitch is placed in a papillary muscle, and a 2-o Gore-Tex suture is passed through the anchor pledget. After full annuloplasty ring placement, the Gore-Tex suture is woven into the prolapsing segment and positioned temporarily with robotic forceps. Chordal length is then “adjusted” by lengthening or shortening the temporary knot over 1-cm increments as the valve is tested by injection of cold saline into the ventricle. After achieving good leaflet position and valve competence, the chord is tied permanently. The “adjustable” ACR procedure preserves leaflet surface area and produces a competent valve in the majority of patients. Postoperative transesophageal echo shows a large surface area of coaptation. Patient recovery is facilitated by the minimally invasive approach, while long-term stability of similar open ACR techniques have been excellent with a 2% to 3% failure rate over 10 years of follow-up. Robotic Gore-Tex ACR without leaflet resection is a reproducible procedure that simplifies mitral repair for prolapse. The outcomes observed in early robotic applications have been excellent. It is suggested that most patients with simple prolapse might validly be approached in this manner.

Results of mitral valve annuloplasty with a standard-sized posterior band: is measuring important?

OBJECTIVE

This study was undertaken to determine hemodynamic and clinical outcomes of annuloplasty with a standard-sized (63 mm) posterior band in adult patients undergoing mitral valve repair for degenerative valve disease.

METHODS

We studied 511 patients who underwent isolated mitral valve repair for degenerative disease with a 63-mm posterior band used for annuloplasty. Operations were performed between 1994 and 2001, and average follow-up was 4.8 +/- 3.1 years. Echocardiographic data were reviewed, with specific focus on the relationship between patient size and residual mitral regurgitation and gradient.

RESULTS

Mean age at the time of operation was 59.3 +/- 13.5 years, and 72% were male. Body mass index was 25.8 +/- 4.1 kg/m(2), and body surface area was 1.97 +/- 0.24 m(2). Preoperative mean ejection fraction was 64% +/- 7%, and 96% of patients had severe mitral regurgitation on preoperative echocardiography. The 30-day mortality was 0.8%. At hospital discharge, the mean gradient was 4.7 +/- 3.1 mm Hg. Body surface area, body mass index, and weight were not associated with postoperative gradients or residual regurgitation at discharge. At last follow-up, 89% of patients had no or mild regurgitation, and the mean ejection fraction was 58% +/- 9%. At 5 years, survival was 95% and cumulative risk of reoperation was 3%.

CONCLUSION

A standard-sized (unmeasured) posterior annuloplasty band provided excellent intermediate results with good durability. There were neither excess gradients in larger patients nor excess regurgitation in smaller patients. Measured annuloplasty is unnecessary for most adults undergoing mitral valve repair.

Mitral annuloplasty

Annuloplasty is an essential component of surgical mitral valve repair to stabilize the repair and improve leaflet coaptation, decrease the stress on the leaflets and sutures, and increase the durability of the reconstructive procedure. Different annuloplasty methods and devices are available. The procedure can be carried out with minimal risks and satisfactory effects if choice of the appropriate device, sizing and implant technique follow a standardized approach which is described below.

Preoperative Determination of Artificial Chordae Length

We present a practical and accurate way to measure artificial chordae length in mitral valve repair. During preoperative transesophageal echocardiography, the distance between the head of the posterior papillary muscle and the mitral annulus plane at the coaptation of the leaflets is measured; this is the length of the new chorda. Every millimeter of braided 4-0 Gore-Tex (W.L. Gore & Assoc, Flagstaff, AZ) contains two tight reverse knots; therefore, the number of the knots determines the accurate length of the artificial chorda.

Annular-to-leaflet mismatch and the need for reductive annuloplasty in patients undergoing mitral repair for chronic mitral regurgitation due to mitral valve prolapse

Annular dilation is a common feature of chronic degenerative mitral regurgitation caused by leaflet prolapse. Accordingly, patients undergoing surgical repair usually undergo concomitant reductive annuloplasty to restore a normal annular-to-leaflet relation. With the evolution of transcatheter valve repair technologies, patient selection criteria for those who do not require annuloplasty are needed. A series of patients undergoing mitral repair was analyzed, and the role of annular-to-leaflet mismatch in identifying patients requiring reductive annuloplasty was explored. Preoperative data for 82 patients undergoing mitral repair with annuloplasty for degenerative mitral regurgitation were prospectively collected, including annular intercommissural (IC) and septolateral (SL) dimensions and heights of anterior (ALH) and posterior leaflets. An SL/ALH ratio >1.4 was used to define annular-to-leaflet mismatch. After mitral repair, the ratio between preoperative IC distance and the size of the implanted annular prosthesis (Seguin ring [SR], IC/SR <1.2) was used to identify patients for whom annuloplasty was nonreductive. All patients underwent successful mitral repair. Mean preoperative IC was 46 +/- 6 mm, SL was 42 +/- 5 mm, and ALH was 31 +/- 5 mm. Mean SR was 34 +/- 3 mm, with a mean IC/SR ratio of 1.34 +/- 0.14. Sixteen patients (19%) had an IC/SR ratio <1.2. IC/SR ratio <1.2 was predicted by a SL/ALH ratio < or =1.4 (p = 0.009). In conclusion, annular dilation is negligible in <20% of surgical candidates. In this subgroup, an isolated leaflet repair may be indicated. SL/ALH ratio is a good indicator of annular-to-leaflet mismatch and could be used as an adjunct to other methods of annular function assessment to select patients for ringless mitral repair.

Mitral valve repair for degenerative mitral regurgitation

Mitral valve repair for degenerative mitral regurgitation is nowadays one of the most common valvular procedures. Different technical modifications were added to the original Carpentier's method, trying to maximise the stability of the results and to reduce the incidence of immediate complications and of late failure of the correction. Survival is good, even if recent reports showed that recurrence of mitral regurgitation can be higher than expected. Prolapse of the anterior leaflet remains challenging and is related to higher reintervention rates. Nevertheless, the overall success rate is high, and the increasing experience of the different surgical teams approaching this procedure will help maintain satisfactory and stable long-term results.

Choice of artificial chordae length according to echocardiographic criteria

A simple way to identify artificial chordae length is reported. The distance A between the edge of the prolapsing anterior leaflet and the plane of the mitral annulus is measured during perioperative transesophageal echocardiography. When the mitral valve is exposed, the elongated chorda, corresponding to the scallop previously evaluated, is measured with a ruler and A is subtracted. This is the length of the new chorda that is measured with a ruler and tied at that level after being properly positioned.

Overreduction of the Posterior Annulus in Surgical Treatment of Degenerative Mitral Regurgitation

BACKGROUND

The concept of overreduction of the posterior annulus was applied in surgical treatment of degenerative mitral valve disease.

METHODS

From April 1993 to November 2004, 141 patients underwent overreduction of the posterior annulus of the mitral valve in mitral valve repair for degenerative disease. Mean scallop involvement per patient was 2.3 and increased to 3.0 in the last period. Correction of the prolapse of the posterior leaflet included resection with focal sliding (n = 100), or application of artificial chordae (n = 28), with (n = 11) or without (n = 17) plication of one or more scallops. The anterior leaflet prolapse was corrected with edge-to-edge technique (n = 20) or chordal replacement (n = 28). An overreducting ring, 40 (n = 81) or 50 (n = 60) mm long (autologous pericardium in 64 cases and Sovering Miniband [Sorin, Saluggia, Italy] in 77) was used in all the patients.

RESULTS

Three patients died in the early period (2.1%) and 3 (2.1%) were reoperated on from 3 to 24 months due to endocarditis (2 cases) and failure of repair (1 case). Ten-year freedom from death any cause was 91.6%, from reoperation 96.4%, from death any cause and reoperation 87.7%, from death any cause, reoperation, and New York Heart Association class III-IV 79.8%. Sixty-four patients out of 68 who survived more than 2 years (94.1%) at a mean follow up of 4.2 +/- 2.5 years had no or 1+ residual mitral regurgitation.

CONCLUSIONS

Although the complexity of mitral valve repair for degenerative disease increased, results of surgery remained stable. Apposition of a posterior overreductive ring was useful to cover any mistake performed during the correction.

Subvalvular repair: the key to repairing ischemic mitral regurgitation?

BACKGROUND

Residual or recurrent mitral regurgitation frequently occurs after mitral ring annuloplasty repair for ischemic mitral regurgitation (IMR), because annuloplasty primarily addresses annular dilatation. We describe a subvalvular repair technique addressing posterior papillary muscle (PPM) displacement.

METHODS AND RESULTS

Ten sheep had radiopaque markers placed on the left ventricle (LV) and mitral apparatus. A suture was anchored at the right fibrous trigone, passed through the PPM tip and LV wall, and exteriorized through a tourniquet (STRING-1). A second suture was anchored transmurally in the high septum (anterobasal LV wall) and passed through the PPM and LV wall (STRING-2). Reversible posterolateral ischemia was induced by temporarily occluding the proximal circumflex artery. Under open chest conditions, 3D marker coordinates were obtained with biplane videofluoroscopy at baseline and during acute ischemia before and after tightening of each STRING using transesophageal echocardiography to grade IMR. IMR decreased (mean+/-SEM, 2.0+/-0.1 to 1.2+/-0.1; P<0.05) when STRING-1 was tightened, did not change after tightening STRING-2 (2.3+/-0.1 to 2.3+/-0.1), and decreased after tightening both sutures (STRING-1+2, 2.3+/-0.2 to 1.3+/-0.2; P<0.05). STRING-1 and STRING-1+2 (STRING-1, 1.7+/-0.4 mm; STRING-2, 0.7+/-0.5 mm; STRING-1+2, 1.5+/-0.3 mm; P<0.05) resulted in significant PPM basal repositioning. Tightening of any STRING sutures did not affect anterior mitral leaflet excursion.

CONCLUSIONS

Basal repositioning of the PPM with STRING-1 reduced acute IMR without concomitant annular reduction. This technique may be a useful adjunct if residual IMR is likely after undersized ring annuloplasty.

Seven years’ experience with suture annuloplasty for mitral valve repair

OBJECTIVE

Our early experience with the mural annulus shortening suture procedure for mitral valve repair showed superior hemodynamic performance over ring annuloplasty. The aim of this study was to assess the durability of the mural annulus shortening suture procedure and evaluate our 7-year experience regarding valve function, hemodynamic performance, and clinical outcome.

METHODS

Between 1996 and 2003, 222 elective consecutive patients (58.1% males; age, 59 +/- 14 years) underwent simple or complex mitral valve repair. Minimal invasive reconstruction was performed in 150 patients. For correction of annular dilatation, we used double-running 2-0 polytetrafluoroethylene sutures to reinforce the posterior circumference of the annulus. Patients were investigated prospectively by means of transthoracic echocardiography before discharge and 1 and 5 years after the operation. The mean follow up was 32 +/- 21 months (range 1-77 months).

RESULTS

The operative mortality was 3.1%. Hemodynamic performance at 1 and 5 years showed low mean transvalvular gradients (2.1 +/- 0.9 and 2.0 +/- 0.8 mm Hg, respectively) and a calculated mitral valve orifice area of 3.3 +/- 0.9 cm2 and 3.1 +/- 0.6 cm2, respectively, with progressive annular dilatation from 31.2 +/- 3 mm to 33.9 +/- 4 mm at 1 year and 35.7 +/- 4 mm at 5 years (P < .01). Clinical status improved from New York Heart Association class 3.0 +/- 0.4 to 0.6 +/- 0.8 at 1 year and 0.8 +/- 0.8 at 5 years. Freedom form nontrivial residual mitral regurgitation was 82.3%, freedom from reoperation was 95.1% and actuarial survival was 87.2%, all at 77 months.

CONCLUSIONS

The midterm results show satisfactory hemodynamic performance and clinical improvement. Valve competence and reoperation rates are comparable with those of other reports. Durability of the mural annulus shortening suture procedure for mitral valve repair is questioned because progressive annular redilatation occurs.

Structural Characterization of the Chordae Tendineae in Native Porcine Mitral Valves

BACKGROUND

This study was aimed to characterize the different mitral valve chordae tendineae to provide additional understanding of their function.

METHODS

Mitral valve chordae tendineae from fresh porcine hearts were stained for collagen and elastin using either a Verhoeff and van Gieson stain or Verhoeff light green stain. Cellular distribution was determined using a hematoxylin and eosin stain. Immunohistochemistry was used to verify the findings of vasculature. Biochemical assays were performed to quantify DNA, collagen, and elastin content of each of the six different types of chordae tendineae.

RESULTS

Blood vessels were observed in the longitudinal and circumferential directions of the chordae. The strut chordae on the anterior leaflet of the mitral valve showed an increased degree of vascularization compared with the other chordae. All chordae had an inner layer characterized by a high concentration of collagen and an outer layer that was mostly elastin with interwoven collagen fibers. The collagen microstructure was characterized by directional crimping. Hematoxylin and eosin staining showed fibroblasts evenly distributed throughout the inner and outer layer of the chordae tendineae. Quantitative analysis showed significantly higher levels of DNA and collagen content in the anterior and posterior marginal chordae compared with the other chordae.

CONCLUSIONS

The chordae tendineae were seen to have different microstructures according to chordal type. The presence of vessels characterized the chordae tendineae as complex living components that work in coordination with the papillary muscles and mitral valve leaflets to prevent mitral valve prolapse and regurgitation. They may also function to supply nutrients to the valve leaflets.

Neochordal repair of the posterior mitral leaflet

BACKGROUND

Myxomatous mitral valve insufficiency is traditionally repaired by posterior leaflet quadrangular resection and reconstruction. A simplified repair technique without leaflet resection is described, and our initial experience is reviewed.

METHODS

Thirty-nine consecutive patients with significant mitral regurgitation underwent repair since January 2000 by placement of expanded polytetrafluoroethylene sutures between the leading (coapting) edge of the posterior leaflet and the corresponding papillary muscle. An annuloplasty ring was placed, and no leaflet tissue was resected. Patient medical records were obtained and retrospectively reviewed.

RESULTS

Twenty-five men and 14 women (median age, 61 years; range, 40-88 years) had their mitral valve repaired by a variety of surgical approaches, including robotic (18 patients), right thoracotomy (6 patients), and sternal (15 patients). Three patients have required valve replacement: 1 at the initial operation, 1 because of dehiscence of the annuloplasty ring, and 1 after subsequent rupture of a previously normal native chorda. At follow-up (median, 12 months), 92% (33/36) of the remaining patients had an intact mitral repair with no to mild regurgitation, 8.3% (3/36) of patients had moderate regurgitation, and 92% of all patients (36/39) were in New York Heart Association class I. There were no deaths.

CONCLUSIONS

Myxomatous mitral regurgitation due to posterior leaflet insufficiency can be repaired without leaflet resection by placement of neochordae. This repair technique is effective and is readily accomplished by traditional and minimally invasive surgical approaches.

Advances in Heart Valve Surgery

Heart valve surgery continues to evolve in a dynamic fashion. While the exact role of minimally invasive approaches still needs to be defined, progress has been made in the development of new bioprostheses and their durability. Most importantly, valve repair has been standardized for the mitral and introduced for the aortic valve with results that have been superior to valve replacement. Selection of the optimal procedure for the individual patient is now facilitated. In the future, a wider application of repair procedures and further improvements of biologic valves can be anticipated not only to influence long-term results but also the decision-making process for conservative or surgical treatment.

Midterm results of edge-to-edge mitral valve repair without annuloplasty

OBJECTIVE

Edge-to-edge mitral valve repair is usually performed in association with annuloplasty, with rare exceptions. We retrospectively analyzed the results of ringless edge-to-edge repair, particularly in view of minimally invasive and percutaneous approaches.

METHODS

From November 1993 to December 2001, 81 patients underwent edge-to-edge mitral repair without associated annuloplasty. The cause was degenerative in most patients. In 32 patients the annulus was severely calcified. Type I lesions were present in 6 patients, type II lesions in 60 patients, and type III lesions in 15 patients. A double-orifice repair was done in 69 patients, and paracommissural repair was done in 12 patients. In 5 patients edge-to-edge repair was used as a rescue procedure.

RESULTS

There were 3 hospital and 4 late deaths, for a 4-year survival of 85% +/- 6.7%. At latest follow-up, 63 patients were in New York Heart Association classes I or II, and 9 patients were in classes III or IV. Nine patients required reoperation (89% +/- 3.9% overall freedom from reoperation at 4 years). Annular calcification was associated with a greater reoperation rate (77% +/- 22% vs 95% +/- 4.6% freedom from reoperation, P =.03). Intraoperative water testing and postrepair transesophageal echocardiography predicted late failure. Only 1 of 42 patients required reoperation in the follow-up period when annular calcification, rheumatic disease, or rescue procedure were not present as risk factors.

CONCLUSIONS

Our data confirm overall suboptimal results of the edge-to-edge technique when annuloplasty is not added to the repair. Annular calcification, rheumatic cause, and edge-to-edge repair done as a rescue procedure were associated with the worst outcome. Midterm results in selected patients encourage future developments in catheter-based edge-to-edge procedures.

Late outcomes of mitral valve repair for floppy valves: Implications for asymptomatic patients

OBJECTIVES

We sought to evaluate the long-term results of mitral valve repair in patients with mitral regurgitation caused by floppy mitral valves and compare the outcomes of asymptomatic patients with those of symptomatic patients.

METHODS

A retrospective review of 488 consecutive patients who had mitral valve repair for floppy mitral valve disclosed 199 patients who were asymptomatic or had minimal symptoms and 289 patients who were symptomatic at the time of the operation. Asymptomatic patients were younger, had better ventricular function, had a lower incidence of coronary artery disease, and had higher rates of atrial fibrillation than symptomatic patients.

RESULTS

Survival at 15 years was 61% for all patients. Survival was 76% for asymptomatic patients, which was identical to that for the general population matched for age and sex, whereas the survival of symptomatic patients was 53% and significantly lower than that of the general population. Cox regression analyses validated by means of bootstrap methodology identified the following predictors of late death: age by increments of 5 years (risk ratio = 1.2), New York Heart Association functional classes 3 and 4 (risk ratio = 3.0), left ventricular ejection fraction of less than 40% (risk ratio = 2.7), preoperative stroke or transient ischemic attack (risk ratio = 3.1), previous cardiac operation (risk ratio = 4.6), and severe chronic obstructive pulmonary disease (risk ratio = 3.1). Freedom from reoperation at 15 years was 91%, and it was similar for asymptomatic and symptomatic patients. Freedom from mitral regurgitation of greater than 2+ at 15 years was 85% for all patients, 96% for asymptomatic patients, and 76% for symptomatic patients.

CONCLUSIONS

This study supports the recommendation of surgical intervention in asymptomatic patients with mitral regurgitation caused by a floppy mitral valve if mitral valve repair is feasible and associated with low operative mortality and morbidity.

Mitral valve repair for degenerative disease: is pericardial posterior annuloplasty a durable option?

OBJECTIVE

Biological and prosthetic rings are available for supporting mitral valve repair (MVR). Contrasting data are reported on the durability of pericardial ring annuloplasty. This retrospective study was undertaken to assess the durability of MVR for degenerative regurgitation with posterior annuloplasty performed with glutaraldehyde-treated autologous pericardium.

METHODS

From August 1995 through December 2000, 133 patients underwent mitral repair for degenerative regurgitation (86 men, age 62.9+/-11.5 years). Thirty patients (22.6%) underwent combined coronary artery bypass graft and fourteen (10.5%) underwent tricuspid annuloplasty. Associated aortic disease, previous cardiac surgery and endocarditis were considered exclusion criteria.

RESULTS

Seventy-seven patients (57.9%) received a Carpentier-Edwards ring and 56 received (42.1%) an autologous pericardium ring. Thirty-day mortality was 3.8%. Mean follow-up, 98.3% complete, was of 35.6+/-18.7 months. Five-year freedom from reoperation and recurrence of mitral regurgitation> or =3+/4+ was significantly higher in the prosthetic ring group (90.1% - CL90%: 81.9-98.3%) compared with the pericardial ring group (62.6% - CL90%: 43.1-82.1%; P=0.027). Prosthetic ring implantation (P=0.004; RR=0.11) and preoperative New York Heart Association (NYHA) class< or =II (P=0.011; RR=0.16) were independently related to a lower risk of reoperation and recurrence of mitral regurgitation> or =3+/4+, by multivariate analysis. Five-year overall survival was 91.4% (CL90%: 87.9.7-95%). A higher preoperative left ventricular end-diastolic diameter (P=0.006; RR=1.17) and the severity of associated coronary artery disease (P=0.021; RR=2.00) were independent predictive factors for poor survival by multivariate analysis.

CONCLUSIONS

Posterior pericardial annuloplasty can jeopardize reproducibility and durability of MVR for degenerative regurgitation.

Ischemic mitral regurgitation: intraventricular papillary muscle imbrication without mitral ring during left ventricular restoration

OBJECTIVES

Functional mitral regurgitation in ischemic cardiomyopathy carries a poor prognosis, and its surgical management remains problematic and controversial. The aim of this study was to report the results of our surgical approach to patients who have had myocardial infarctions and have ventricular dilatation, mitral regurgitation, reduced pump function, pulmonary hypertension and coronary artery disease. This surgical approach consists of endoventricular mitral repair without prosthetic ring, ventricular reconstruction with or without patch, and coronary artery bypass grafting.

PATIENTS

Forty-six patients (aged 64 +/- 10 years) with previous anterior transmural myocardial infarction and mitral regurgitation comprised the study group. Indication for surgery was heart failure in 93% of cases; 25 patients were in New York Heart Association functional class IV and 17 were in class III. Mitral regurgitation was moderate to severe in 32 cases (69%).

RESULTS

All patients underwent coronary artery bypass grafting, with a mean of 3.2 +/- 1.3 grafts. Associated aortic valve replacement was performed in 4 cases. Global operative mortality rate was 15.2%. End-diastolic and end-systolic volumes significantly decreased after surgery (from 140 +/- 40 to 98 +/- 36 mL/m(2) and from 98 +/- 32 to 63 +/- 22 mL/m(2), respectively, P =.001). Systolic pulmonary pressure decreased significantly (from 55 +/- 13 to 43 +/- 16 mm Hg, P =.001). Ejection fraction did not change significantly. Postoperative mitral regurgitation was absent or minimal in 84% of cases; 1 patient had severe mitral regurgitation necessitating valve replacement. New York Heart Association functional class significantly improved. The mean preoperative functional class was 3.4 +/- 0.6 (median 3, range 2-4); after the operation, this decreased to 1.9 +/- 0.7 (median 2, range 1-3, P <.001). Cumulative survival at a 30-month follow-up was 63%.

CONCLUSIONS

Our aggressive, combined surgical approach is aimed at correcting the three components of ischemic cardiomyopathy: relieving ischemia, reducing left ventricular wall tension by decreasing left ventricular volumes, and reducing volume overload and pulmonary hypertension by repairing the mitral valve. Despite a relatively high perioperative mortality rate, surviving patients benefitted from the operation, with improved clinical functional class and thus quality of life.

Chordal plication and free edge remodeling for mitral anterior leaflet prolapse repair: 8-year follow-up

BACKGROUND

Chordal suture plication and free edge remodeling represent a personal technique for the repair of anterior leaflet prolapse. We report the results of an 8-year experience.

METHODS

Sixty-one patients with degenerative mitral regurgitation caused by prolapse of the anterior leaflet (11) or both leaflets (50) underwent anterior leaflet prolapse repair. Twenty patients who had associated cardiac procedures are included.

RESULTS

There were two perioperative deaths. Postoperative mitral regurgitation fell to 0.4 +/- 0.7 versus 3.7 +/- 0.4 preoperative (p < 0.0001). Mean follow-up was 40.5 months. There were 3 late deaths and 3 mitral reoperations (1 of 3 repairs, 2 of 3 replacements). Thromboembolism and endocarditis occurred in 1 patient each. Actuarial overall survival, freedom from cardiac death, and freedom from mitral reoperation at 92 months were 85.1% +/- 7.9%, 88.9% +/- 7.7%, and 94.6% +/- 3.0%, respectively.

CONCLUSIONS

Our technique of anterior leaflet prolapse repair appears effective, safe, and durable at mid- to long-term follow-up, and may be used in the presence of extensive disease of both leaflets.

Long-term histologic features of synthetic chordal replacement for mitral valve repair: a case report

Expanded polytetrafluoroethylene (e-PTFE) sutures have been used with increasing frequency to replace chordae tendineae in mitral valves prolapsing because of myxoid change. A case is reported where fibrosis and calcification of the endocardial overgrowth covering the synthetic chordae led to severe mitral regurgitation 7 years after plastic repair and required mechanical prosthetic valve implantation.