Minimally Invasive Edge-to-Edge Mitral Repair With or Without Artificial Chordae

Elevated gradient after mitral valve repair: The effect of surgical technique and relevance of postoperative atrial fibrillation

OBJECTIVES

We sought to investigate the effect of surgical technique in mitral valve repair on postoperative transmitral gradient (PTMG) and the relationship between PTMG and postoperative atrial fibrillation (AF).

METHODS

In this retrospective study, 390 patients who underwent mitral valve repair for degenerative mitral regurgitation without AF were included. PTMG was measured using transthoracic echocardiography before patient discharge. At follow-up, occurrences of AF within 6 months of surgery (early AF) and 6 months after surgery (late AF), as well as clinical and echocardiographic data were documented and investigated.

RESULTS

The in-hospital mortality was 0, and the mean gradient was 3.1 ± 1.2 mm Hg before patient discharge. The risks for higher PTMG included cleft closure, edge-to-edge technique, full ring annuloplasty, and smaller indexed prosthetic size (P < .05 for all). After a median follow-up of 46 months, stable sinus rhythm was maintained in 73.1% of the overall cohort and early AF occurred in 22.7% of patients. A total of 32 patients (8.5%) had late AF, which was significantly associated with PTMG (odds ratio, 3.93; P = .004). The minimum P value approach identified a mean gradient of ≥4.5 mm Hg as the best threshold for predicting late AF (χ² = 40.704; P < .001).

CONCLUSIONS

Patients who undergo mitral valve repair for degenerative mitral insufficiency might benefit from modification of the existing leaflet repair and annuloplasty techniques to achieve a lower PTMG level, which is associated with a decreased incidence of late AF during midterm follow-up.

Management of Incomplete Initial Repair in the Treatment of Degenerative Mitral Insufficiency

We sought to present our institutional protocol to manage incomplete initial repair of degenerative mitral regurgitation and to evaluate its mid-term outcomes. Eight hundred and fifteen patients with degenerative mitral insufficiency undergoing mitral valve repair were investigated in this study. The initial repair attempt was incomplete in 48 patients, leaving a degree of residual regurgitation > mild, and an elevated transmitral gradient or systolic anterior motion (SAM). These patients were further treated with medication or mitral valve re-repair or replacement under reinstituted cardiopulmonary bypass. Transesophageal echocardiographic reports and operational records were reviewed to identify morphological causes and establish management of incomplete initial repair. Mid-term outcomes of patients with re-repair and complete initial repair were evaluated and compared. Residual mitral regurgitation > mild was detected in 25 patients, an elevated transmitral gradient was detected in seven patients, and SAM was detected in 16 patients. The condition of eight patients with SAM was resolved with medication only. Mitral valve re-repair was performed in 23 patients and replacement was performed in 17, with comparable early mortality and morbidity. At 60.3 ± 25.5 months after surgery, late mitral stenosis and reoperation rate were significantly higher in re-repair patients than in patients with complete initial repair, despite comparable survival, left chamber reverse remodeling, and degree of residual regurgitation. Based on our institutional protocol, acceptable outcomes can be achieved for patients with incomplete initial mitral valve repair. Management should be tailored based on the characteristics of the mitral valve complex, expected repair durability, and operative risk.

Mitral Valve Surgery: Current Minimally Invasive and Transcatheter Options

The mitral valve is a highly complex structure, the competency and function of which relies on the harmonious action of its component parts. Minimally invasive cardiac surgery (MICS) for mitral valve repair or replacement (MVR/r) has been performed successfully with incremental improvements in techniques over the past decade. These minimally invasive procedures, while attractive to patients and referring physicians, should meet the same high bar for optimal clinical outcomes and long-term durability of valve repair as traditional sternotomy procedures. The majority of MICS MVR/r procedures are performed via a right minithoracotomy approach with direct or camera-assisted visualization, with a minority of centers performing robotic MVR/r. Outcomes with MICS MVR/r have been shown to have similar morbidity and mortality rates as traditional sternotomy MV procedures but with the advantage of reduced transfusions, postoperative atrial fibrillation, and time to recovery. More recently, transcatheter mitral valve repair and replacement (TMVR/r) has become a reality. Percutaneous MV repair technology is currently FDA approved for patients with nonsurgical high-risk degenerative mitral regurgitation. Other TMVR/r technology is at various levels of preclinical and clinical investigation, although these devices are proving to be more challenging compared to transcatheter aortic valve replacement (TAVR) due to the significantly more complex mitral anatomy and the greater heterogeneity of mitral disease requiring treatment. In this article, we review current techniques for MICS MVR/r and upcoming catheter-based therapies for the mitral valve.

Comparison of the Outcomes of Modified Artificial Chordae Technique for Mitral Regurgitation through Right Minithoracotomy or Median Sternotomy

Background:

Right minithoracotomy (RM) has been proven to be a safe and effective approach for mitral valve surgery, but the differences of artificial chordae technique between RM and median sternotomy (MS) were seldom reported. Here, we compared the outcomes of modified artificial chordae technique for mitral regurgitation (MR) through RM or MS approaches.

Methods:

One hundred and eighteen consecutive adult patients who received mitral valve repair with artificial chordae and annuloplasty for MR through RM (n = 58) or MS (n = 60) from January 2006 to January 2015 were analyzed.

Results:

All of the selected patients underwent mitral valve repair successfully without any complication during the surgery. There was no significant difference between RM group and MS group in cardiopulmonary bypass time, aortic cross-clamp time, and early postoperative complications. However, compared with the MS group, the RM group had shorter hospital stay and faster surgical recovery. At a mean follow-up of 44.8 ± 25.0 months, the freedom from more than moderate MR was 93.9% ± 3.5% in RM group and 94.8% ± 2.9% in MS group at 3 years postoperatively. Log-rank test showed that there was no significant difference in the freedom from recurrent significant MR between the two groups (χ² = 0.247, P = 0.619). Multivariate analysis revealed that the presence of mild MR at discharge was the independent risk factor for the recurrent significant MR.

Conclusion:

Right minithoracotomy can achieve the similar therapeutic effects with MS for the patients who received modified artificial chordae technique for treating MR.