Anatomical study of the tricuspid valve and its variations

Septal annular dilation in chronic ovine functional tricuspid regurgitation

INTRODUCTION

Annular reduction with prosthetic rings represents the current surgical treatment of functional tricuspid regurgitation (FTR). However, alterations of annular geometry and dynamics associated with FTR are not well characterized.

METHODS

FTR was induced in 29 adult sheep with either 8 weeks of pulmonary artery banding (PAB, n = 15) or 3 weeks of tachycardia-induced cardiomyopathy (TIC, n = 14). Eight healthy sheep served as controls (CTL). At the terminal procedure, all animals underwent sternotomy, epicardial echocardiography, and implantation of sonomicrometry crystals on the tricuspid annulus (TA) and right ventricular free wall while on cardiopulmonary bypass. Simultaneous hemodynamic, sonomicrometry, and echocardiographic data were acquired after weaning from cardiopulmonary bypass and stabilization. Annular geometry and dynamics were calculated from 3-dimensional crystal coordinates.

RESULTS

Mean FTR grade (0-4) was 3.2 ± 1.2 and 3.2 ± 0.5 for PAB and TIC, respectively, with both models of FTR associated with similar degree of right ventricular dysfunction (right ventricular fractional area contraction 38 ± 7% and 37 ± 9% for PAB and TIC, respectively). Left ventricular ejection fraction was significantly reduced in TIC versus baseline (33 ± 9%, vs 58 ± 4%, P = .0001). TA area was 651 ± 109 mm2, 881 ± 242 mm2, and 995 ± 232 mm2 for CTL, FTR, and TIC, respectively (P = .006) with TA area contraction of 16.6 ± 4.2%, 11.5 ± 8.0%, and 6.0 ± 4.0%, respectively (P = .003). Septal annulus increased from 33.8 ± 3.1 mm to 39.7 ± 6.4 mm and 43.1 ± 3.2 mm for CTL, PAB, and TIC, respectively (P < .0001).

CONCLUSIONS

Ovine FTR was associated with annular dilation and reduced annular area contraction. Significant dilation of septal annulus was observed in both models of FTR. As tricuspid rings do not completely stabilize the septal annulus, continued remodeling may contribute to recurrent FTR after repair.

Tricuspid Annulus Dilation in Patients With Combined Functional Tricuspid Regurgitation and Left-Heart Valvular Disease: Does Septal Annulus Not Dilate?

Background

This study aimed to investigate the course of tricuspid annulus dilation in functional tricuspid regurgitation with varied severities by direct intraoperative assessment.

Methods

A total of 317 patients who underwent left heart surgery and concomitant tricuspid repair were divided into three groups according to the severity of the functional tricuspid regurgitation (mild, moderate and severe). Demographic and echocardiographic data were collected. The length of each tricuspid annulus segment was measured intraoperatively. The risk factors for preoperative severe functional tricuspid regurgitation and its postoperative recurrence were identified, and the impact of each tricuspid annulus segment on postoperative recurrence was compared.

Results

In the course of tricuspid annulus dilation, the posterior annulus dilated 17% (group 1: 33.31 ± 6.94 mm vs. group 2: 35.56 ± 7.63 vs. group 3: 38.98 ± 8.70, p < 0.01), the anterior annulus dilated 13.4% (group 1: 36.71 ± 6.30 mm vs. group 2: 38.21 ± 8.35 vs. group 3: 41.63 ± 9.20, p < 0.01), and the septal annulus dilated 11.4% (group 1: 38.11 ± 5.28 mm vs. group 2: 39.76 ± 6.90 vs. group 3: 42.46 ± 7.50, p < 0.01). Tricuspid annulus circumference index (p < 0.01) independently correlated with preoperative severe tricuspid regurgitation and postoperative recurrence. When patients were grouped based on the length of each segment, the septal annulus demonstrated significantly higher sensitivity (p < 0.001) to postoperative recurrence than the anterior (p = 0.085) or posterior annulus (p = 0.262).

Conclusions

This study revealed that each segment of tricuspid annulus could dilate in functional tricuspid regurgitation and highlighted the potential benefits of septal annulus plication in tricuspid annuloplasty, which may aid in the development of a methodology for prosthetic ring annuloplasty.

3-Dimensional Echocardiography in Imaging the Tricuspid Valve

Tricuspid regurgitation (TR) is an independent predictor of death. Lately, emerging technologies for the treatment of TR have increased the interest of physicians. Due to the complex 3-dimensional (3D) geometry of the tricuspid valve (TV) and its anterior position in the mediastinum, conventional 2D echocardiography is unsuitable to study the anatomy and pathophysiologic mechanisms of the regurgitant TV. 3D echocardiography has emerged as a very cost-effective imaging modality with which to: 1) visualize the TV anatomy; 2) define the mechanism of TR; 3) measure the size and geometry of the tricuspid annulus; 4) analyze the anatomic relationships between TV apparatus and surrounding cardiac structures; 5) assess volumes and function of the right atrium and ventricle; and 6) plan surgical repair or guide and monitor transcatheter interventional procedures.

Strategies for tricuspid re-repair in Ebstein malformation using the cone technique

BACKGROUND

Successful tricuspid repair for Ebstein malformation (EM) is challenging. Cone repair has recently emerged as the most anatomic repair technique. There are no data on tricuspid re-repair in EM. We reviewed our experience with tricuspid valve (TV) re-repair using a cone technique.

METHODS

Between June 2007 and October 2012, 134 patients underwent cone repair. Prior TV repair was performed in 20 patients (10 female, 50%). Median age was 15 years (range, 4 to 68 years). Four patients (20%) had prior bidirectional cavopulmonary anastomosis (BDCPA). Preoperative heart failure was present in 8 patients (40%). Recurrent tricuspid regurgitation (TR) was due to incomplete leaflet coaptation with tethered anterior leaflet in all patients; and 10 patients (50%) had diminutive septal leaflet. Prior repair techniques consisted of annuloplasty maneuvers in all patients with no or incomplete surgical delamination in all patients.

RESULTS

The TV re-repair using cone technique was possible in all patients. Plication of atrialized right ventricle was done in 6 patients (30%). Modifications included annuloplasty band in 16 patients (80%) and TV leaflet augmentation in 8 (40%). The BDCPA was performed in 3 patients (15%) and modified Cox-maze procedure was done in 10 (50%). There were no mortalities or reoperations. Mean follow-up was 7.7 ± 10.7 months; during follow-up, 18 patients had no or mild TR and 2 had moderate TR.

CONCLUSIONS

TV re-repair in EM using the cone technique is feasible, particularly when there has been no surgical leaflet delamination at initial operation. Leaflet augmentation facilitates and annuloplasty band stabilizes a competent TV re-repair. Longer follow-up is required to assess durability.