Surgical reconstruction of the mitral valve

Subannular repair for functional mitral regurgitation type IIIb in patients with ischaemic versus dilated cardiomyopathy

OBJECTIVES

Functional mitral regurgitation (FMR) is a sequel of left ventricular (LV) remodelling in heart failure patients. Relocation of both papillary muscles aims to specifically address mitral leaflet tethering to improve long-term durability of modern FMR repair. Nevertheless, the prognostic impact of the underlying cardiomyopathy on the outcome after FMR repair is unknown.

METHODS

We analysed 84 consecutive heart failure patients with severe FMR, LV ejection fraction <40%, LV end-diastolic diameter ≥55 mm and tenting height >10 mm, who underwent ring annuloplasty and simultaneous bilateral papillary muscles relocation between June 2016 and March 2019. One-year outcome of 54 patients with ischaemic cardiomyopathy ('ICM group') was prospectively compared to the remaining 30 patients with dilated cardiomyopathy ('DCM group').

RESULTS

One-year survival was similar in both groups (96% in the 'ICM group' vs 97% in the 'DCM group'; P = 0.93). Furthermore, primary composite outcome (i.e. freedom from death or mitral regurgitation ≥ 2) at 1-year postoperatively was comparable between the study groups (94%in the 'ICM group' vs 87% in the 'DCM group'; P = 0.10). LV end-diastolic diameter 1-year after surgery was significantly reduced, as compared to preoperative values, in the 'DCM group' (P = 0.018), but not in the 'ICM group' (P = 0.058). Improvement of New York Heart Association functional class and reduction of serum levels of N-terminal pro-B natriuretic peptide at 1 year was comparable in both study groups.

CONCLUSIONS

Standardized relocation of both papillary muscles to correct FMR resulted in very satisfactory in-hospital and 1-year outcomes, in both ICM and DCM. DCM patients showed similar improvement in heart failure symptoms and LV re-remodelling compared to ICM patients. Subannular repair is developing towards a valid therapeutic option in heart failure patients presenting with severe FMR.

Standardized subannular repair for type IIIb functional mitral regurgitation in a minimally invasive mitral valve surgery setting†

OBJECTIVES

Subannular repair techniques in addition to undersized ring annuloplasty have been developed to address high mitral regurgitation (MR) recurrence rates after mitral valve repair in type IIIb MR. We compared the results of annuloplasty with simultaneous standardized subannular repair versus isolated annuloplasty, focusing on the periprocedural outcomes of minimally invasive procedures.

METHODS

A consecutive series of 108 patients with type IIIb functional MR with severe signs of bileaflet tethering underwent an annuloplasty + subannular repair (group A; n = 60) versus isolated annuloplasty (group B; n = 48). The primary end point of this prospective, parallel cohort study was death or recurrent MR >2, 1 year postoperatively. The secondary end points were survival and clinical outcomes, with special regard for the minimally invasively treated subgroups.

RESULTS

Duration of surgery, cardiopulmonary bypass time and aortic cross-clamp time were comparable between both study groups. Procedural outcomes as well as echocardiographic outcome parameters were similar and independent of access (fully endoscopic versus full sternotomy). At the 12-month follow-up, death or MR >2 occurred in 3.3% (2/60) of patients in group A vs in 20.8% (10/48) of patients in group B (P = 0.037). The overall mortality rate during the follow-up period was 1.7% (1/60) in group A vs 12.5% (6/48) in group B (P = 0.041).

CONCLUSIONS

Standardized realignment of papillary muscles is feasible and reproducible via a minimally invasive approach, resulting in excellent periprocedural outcomes, and has a clear potential to significantly decrease MR recurrence and improve 1-year outcomes compared to isolated annuloplasty.

Standardized Subannular Repair Improves Outcomes in Type IIIb Functional Mitral Regurgitation

BACKGROUND

The major drawback of isolated annuloplasty in secondary mitral regurgitation (MR) is the reoccurrence of MR. We prospectively compared the results of isolated annuloplasty vs annuloplasty with simultaneous standardized subannular repair.

METHODS

The study comprised 101 patients with secondary type IIIb MR. Of these, 51 underwent annuloplasty plus standardized subannular repair with realignment of both papillary muscles (subannular repair) and 50 underwent isolated annuloplasty. The primary study end point was the reoccurrence of MR >2 at the 1-year follow-up. Secondary end points were survival, freedom from major adverse cardiac events, and residual leaflet tethering.

RESULTS

Baseline characteristics were comparable in both groups. There was no significant difference in in-hospital mortality (P = .3). Although postrepair MR was comparable between the subannular repair and isolated annuloplasty subgroups, the residual leaflet tethering (tenting area, 127.6 ± 35.8 mm² vs 166.3 ± 47.3 mm², P = .02; posterior mitral leaflet angle, 19.2 ± 4.7 degrees vs 24.8 ± 5.2 degrees, P = .001; anterior mitral leaflet angle, 25.4 ± 5.8 degrees vs 34.1 ± 4.0 degrees, P = .001; and tenting height, 5.9 ± 1.4 mm vs 9.2 ± 2.2 mm, P = .001) were significantly increased in the isolated annuloplasty group (P < .001). At the 1-year follow-up, we found a significant difference between the groups in the freedom from MR >2 of 98% (50 of 51) for subannular repair vs 86.7% (39 of 45) for isolated annuloplasty (P = .045) and mortality of 0% (0 of 51) for subannular repair vs 10% (5 of 50) for isolated annuloplasty (P = .025).

CONCLUSIONS

In secondary MR with reduced leaflet motion, the combination of annuloplasty and standardized subannular repair is associated with a significantly reduced MR reoccurrence, decreased residual leaflet tenting, and significantly improved 1-year outcome compared with annuloplasty alone.

Surgical Echocardiography of the MV: Focus on 3D

The mitral valve remains a complex structure where multiple forms of pathology can be seen. Mitral regurgitation continues to be one of the most common valvular diseases in the industrialized world. While intraoperative 2-dimensional transesophageal echocardiography has been commonplace for some time, 3-dimensional technology has emerged and has shown great benefit for diagnosis and guidance during mitral valve surgery. In the hands of a trained sonographer, high-quality real-time images can easily be obtained and correlate well with gross anatomical findings. The use of multiple angled views and color Doppler within 3-dimensional transesophageal echocardiography has become a valuable asset in the understanding and interpretation of the mitral valve for surgical interventions.

Subannular reconstruction in secondary mitral regurgitation: a meta-analysis

OBJECTIVE

Mitral valve repair using an undersized complete annuloplasty ring in secondary mitral regurgitation with restricted leaflet motion during systole (Carpentier's surgical classification of mitral valve pathology: type IIIb) only inadequately addresses the underlying left ventricular disease. This may lead to an ongoing ventricular remodelling and progressive papillary muscle displacement with increasing leaflet tethering. Several subannular techniques have been proposed to counteract the reoccurrence of mitral regurgitation after mitral valve repair. We aimed to evaluate the potential additive effect of such subannular techniques on the late reoccurrence rate of secondary mitral regurgitation.

METHODS

Systematic literature review and meta-analysis were performed on PubMed, Embase and Google Scholar for studies published up to March 2016 and reporting late reoccurrence of mitral regurgitation after mitral valve repair using standard annuloplasty (control group) versus annuloplasty with subannular correction (study group) cohorts. Primary endpoint was late reoccurrence of mitral regurgitation ≥2 after surgical mitral valve repair, as defined by follow-up echocardiography.

RESULTS

The cumulative number of 1093 patients in 12 included studies served as our study population. A total of 743 patients underwent combined mitral valve repair including annuloplasty and subannular manoeuvre (ie, study group), while the remaining 350 patients underwent an isolated ring annuloplasty (ie, control group). Secondary mitral regurgitation was caused by ischaemic heart disease in 733/743 patients in the study group and 334/350 patients in the control group. Mean echocardiographic follow-up was 42.7±13.9 months. Pooled outcome analysis demonstrated that the combination of subannular repair with ring annuloplasty was associated with a significantly lower reoccurrence rate of mitral regurgitation ≥2 as compared with annuloplasty alone (OR 0.27, 95% CI 0.19 to 0.38, P=0.0001).

CONCLUSION

The combination of subannular reconstruction and mitral valve annuloplasty is associated with a lower late reoccurrence of mitral regurgitation after surgical mitral valve repair, as compared with annuloplasty alone.

Robotic mitral valve repair

BACKGROUND

Mitral valve repair is the standard therapy for patients with severe mitral regurgitation. Currently, robotic mitral valve repair is the least invasive surgical approach and an alternative to the traditional sternotomy. Recent studies and newer guidelines on mitral valve repair advocate for earlier referral to surgery, resulting in better long-term outcomes of valve function and decreased left ventricular remodeling.

PURPOSE

Robotic mitral valve repair outcomes were compared with nonrobotic mitral repair outcomes through analysis of 4 recent studies, one of which was the Food and Drug Administration trial that granted approval of robotic cardiac surgery. Two studies included their own nonrobotic groups for comparison, with one comparing the robotic approach with complete sternotomy, partial sternotomy, and mini-anterolateral thoracotomy to assess all currently available techniques.

CONCLUSIONS

All 4 studies showed positive outcomes including decreased need for postoperative mechanical ventilation, intensive care unit length of stay, and hospital length of stay. The studies also showed that postrepair mitral regurgitation was equivalent to that of traditional open repairs at multiple different periods after surgery.

CLINICAL IMPLICATIONS

Patients should be given the option for minimally invasive robotic mitral valve repair if they have no other risk factors such as peripheral vascular disease that prevent femoral cannulation for cardiopulmonary bypass or the need for concomitant cardiac surgery such as coronary artery bypass. With the equality of robotic outcomes compared with full sternotomy valve surgery comes the need for more research into what kind of complex valve repairs can be done, which methods of repair work best with robotic techniques, whether the learning curve for robotic surgery can be shortened with more widespread use, and what outcomes can be improved upon from this standpoint. Healthcare professionals need to be aware of all choices for patients who need surgical intervention for their mitral regurgitation.

Mitral valve regurgitation and 3D echocardiography

The mitral valve is a complex, dynamic and functional apparatus that can be altered by a wide range of disorders leading to stenosis or regurgitation. Surgical management of mitral valve disease may be difficult. Planned intervention may not always be feasible when the surgeon is faced with complex pathology that cannot be assessed fully by conventional 2D echocardiography. Transthoracic and transesophageal 3D echocardiography can provide a more reliable functional and anatomical assessment of the different valve components and evaluation of its geometry, which can aid the surgeon in planning a more suitable surgical intervention and improve outcomes. Although 3D echocardiography is a new technology, it has proven to be an important modality for the accurate assessment of valvular heart disease and in the future, it promises to be an essential part in the routine assessment of cardiovascular patients.

Trends in cardiac surgery: exploring the past and looking into the future

Today's successes would not be possible without the foundation of yesterday's practitioners and patients. This article assists in the exploration of cardiac surgery procedures, provides a brief historical review of the significant changes in cardiothoracic surgery, and provides an overview of current and future methods of treatment for coronary revascularization and heart failure. It is difficult for one article to encompass all aspects of cardiothoracic surgery. This article highlights many of the transforming moments that have led us to where we are today and explores the current trends of cardiac surgery and possibilities for tomorrow.