Mitral valve repair: moving towards a personalized ring

The Application of Precision Medicine in Structural Heart Diseases: A Step towards the Future

The personalized applications of 3D printing in interventional cardiology and cardiac surgery represent a transformative paradigm in the management of structural heart diseases. This review underscores the pivotal role of 3D printing in enhancing procedural precision, from preoperative planning to procedural simulation, particularly in valvular heart diseases, such as aortic stenosis and mitral regurgitation. The ability to create patient-specific models contributes significantly to predicting and preventing complications like paravalvular leakage, ensuring optimal device selection, and improving outcomes. Additionally, 3D printing extends its impact beyond valvular diseases to tricuspid regurgitation and non-valvular structural heart conditions. The comprehensive synthesis of the existing literature presented here emphasizes the promising trajectory of individualized approaches facilitated by 3D printing, promising a future where tailored interventions based on precise anatomical considerations become standard practice in cardiovascular care.

DynaRing: A Patient-Specific Mitral Annuloplasty Ring With Selective Stiffness Segments

Annuloplasty ring choice and design are critical to the long-term efficacy of mitral valve (MV) repair. DynaRing is a selectively compliant annuloplasty ring composed of varying stiffness elastomer segments, a shape-set nitinol core, and a cross diameter filament. The ring provides sufficient stiffness to stabilize a diseased annulus while allowing physiological annular dynamics. Moreover, adjusting elastomer properties provides a mechanism for effectively tuning key MV metrics to specific patients. We evaluate the ring embedded in porcine valves with an ex-vivo left heart simulator and perform a 150 million cycle fatigue test via a custom oscillatory system. We present a patient-specific design approach for determining ring parameters using a finite element model optimization and patient MRI data. Ex-vivo experiment results demonstrate that motion of DynaRing closely matches literature values for healthy annuli. Findings from the patient-specific optimization establish DynaRing's ability to adjust the anterior-posterior and intercommissural diameters and saddle height by up to 8.8%, 5.6%, 19.8%, respectively, and match a wide range of patient data.

Totally endoscopic aortic valve replacement with concomitant trans-aortic mitral valve repair for mitral regurgitation

Background

Minimally invasive aortic valve procedures through a hemi-sternotomy or a right anterior mini-thoracotomy have gained popularity over the last several years. Totally endoscopic aortic valve replacement (TEAVR) is an innovative and a less invasive (incision-wise) surgical aortic valve replacement technique. The operative steps of TEAVR have been reported previously from our group. Mitral regurgitation (MR) frequently accompanies aortic valve disease that at times may also require repair. Totally endoscopic surgery in such cases has not been tested.

Presentation of the technique

We present a surgical technique for a totally endoscopic approach to aortic valve replacement and concomitant mitral valve repair for primary and secondary MR. An aortotomy incision was used avoiding an atriotomy, which results in an increase in cross-clamp (XC) and cardiopulmonary bypass (CPB) times that could be associated with higher mortality and morbidity. Neochords (artificial chordae tendineae) were used for primary MR and an edge-to-edge approach for secondary MR.

Conclusion

TEAVR and concomitant mitral valve repair can be performed successfully with reasonable XC and CPB times with excellent short-term results.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13019-021-01694-6.

Preoperative determination of artificial chordae tendineae length by transoesophageal echocardiography in totally endoscopic mitral valve repair

OBJECTIVES

Artificial chordae tendineae are widely used for surgical repair in patients with mitral regurgitation due to floppy mitral valve/mitral valve prolapse. Expanded polytetrafluoroethylene has been used to construct these artificial chordae; however, the determination of the optimal length of the chordae prior to surgery has been an issue. For this reason, such a method was developed and the results of its use are presented.

METHODS

Forty-seven consecutive patients with significant mitral regurgitation due to floppy mitral valve/mitral valve prolapse who underwent totally endoscopic mitral valve surgery were studied. The chordae length was predetermined using transoesophageal echocardiography. The length between the top of the fibrous body of the papillary muscle and the coaptation line of the 2 leaflets of the mitral valve was measured and used to define the length of the chordae to be used for repair. Then under stereoscopic vision, a total endoscopic mitral valve repair was performed.

RESULTS

The predicted mean length of chordal loops was 19.76 ± 0.71 mm (median 20, range 16-28) and the actual mean length of chordal loops used was 19.68 ± 0.74 mm (median 20, range 16-26) demonstrating an excellent correlation between the two (r = 0.959). The mean number of chordae loops used per patient was 5.12 ± 0.62 (median 4, range 2-12). All patients at the time of discharge had no or trivial mitral regurgitation on transoesophageal echocardiography.

CONCLUSIONS

The chordae length used for mitral valve repair can be determined prior to surgery using transoesophageal echocardiography with a high degree of accuracy. Further, total endoscopic repair in this group of patients provides excellent results. For these reasons, it is expected that this method will replace most traditional approaches to cardiac surgeries in the years to come.

Early outcomes of mitral valvuloplasty by minimally invasive surgery or sternotomy

BACKGROUND

Disagreement exists regarding methods for repair of the mitral valve. We compared early outcomes of mitral valvuloplasty by a minimally invasive technique and by a median sternotomy.

METHODS

The data of 507 patients (mean age 47.9 ± 15.2 years) undergoing mitral valvuloplasty from January 2015 to June 2018 were analyzed retrospectively. In the study group (n = 225), mitral valvuloplasty via a totally thoracoscopic approach was performed by a single surgeon. In the control group (n = 282), mitral valvuloplasty via the traditional median sternotomy was carried out by other cardiac surgeons in our hospital. Clinical data, surgical results, and follow-up findings in the two groups were comparatively analyzed.

RESULTS

In the study group, the blood transfusion rate (5.3% vs. 20.9%, p < 0.05) and incidences of poor wound healing (0 vs. 5.3%, p < 0.05) and respiratory tract infection (4.4% vs. 16.3%, p < 0.05) were lower, and postoperative hospitalization was shorter (5.9 ± 4.0 vs. 10.7 ± 8.4 days, p < 0.05). Within 30 days after surgery, no patient died in the study group while one died in the control group. The duration of follow-up was 12-36 months (mean 22.9 ± 8.8 months). During follow-up, there were 1 and 0 cases of redo surgery and 1 and 3 deaths in the study group and control group, respectively.

CONCLUSION

Mitral valvuloplasty via a minimally invasive approach is superior to the traditional median sternotomy in terms of early outcomes, especially when performed by experienced surgeons.