The clover technique for the treatment of complex tricuspid valve insufficiency: midterm clinical and echocardiographic results in 66 patients

Current management of tricuspid regurgitation: a focus on the spiral suspension approach

The indication for surgery for tricuspid regurgitation (TR) has reached a major turning point. It has become clear that the presence of moderate or severe TR alone worsens the prognosis of life, and the previous guidelines of Japanese Circulation Society, in which the indication for surgery was recommended at the timing of "right heart failure difficult to treat medically," now recommends surgery with a trigger of "repeated right heart failure" in the 2020 edition. In addition, a new repair technique targeting at subvalvular structure has been developed for end-stage TR to overcome a high TR recurrence rate that is associated with severe right ventricular enlargement and leaflet tethering. This review focuses on the spiral suspension technique, in which the papillary muscles are spirally suspended towards the septal leaflet annulus to correct tethering and enhances the understanding of its application in the context of TR management.

Long-term Results of Clover and Edge-to-Edge Leaflet Repair for Complex Tricuspid Regurgitation

BACKGROUND

The aim of this study was to report the long-term results of the clover and edge-to-edge repair techniques for complex tricuspid regurgitation (TR).

METHODS

This was a single-center observational study. A competing risks proportional-hazards regression model, using the Fine and Gray model, was performed to analyze the time to TR ≥2+, considering death as a competing risk.

RESULTS

A total of 145 consecutive patients (57% female) with severe or moderately severe TR secondary to leaflet prolapse or flail (115 patients), tethering (27 patients), or mixed (3 patients) lesions underwent clover (110 patients) or edge-to-edge repair(35 patients). The TR origin was degenerative in 75% of cases, posttraumatic in 8%, and secondary to dilated cardiomyopathy in 17%. Ring (64%) or suture (31%) annuloplasty was performed in 95% of patients. Concomitant procedures (mainly mitral surgery) were performed in 80% of cases. Hospital death was 5.5%. Follow-up was 98% complete, and median was 15 years (interquartile range, 14-17 years). The 16-year overall survival was 56% ± 5%. Previous cardiac surgery (hazard ratio [HR], 2.83; 95% CI, 1.15-6.93; P = .023) and right ventricular dysfunction (HR, 2.24; 95% CI, 1.01-4.95; P = .046) were identified as predictors of death. The 16-year cumulative incidence function (CIF) of cardiac death with noncardiac death as a competing risk was 19.6%, and previous cardiac surgery (HR, 3.44; 95% CI, 1.23-9.65; P = .019) was detected as the only predictor of the event. At 16 years, the CIF of TR ≥2+ with death as a competing risk was 23.8%. In particular, TR ≥3+ was detected in 4 patients (3%).

CONCLUSIONS

When TR could not be treated by annuloplasty alone, concomitant leaflet repair with the clover or edge-to-edge technique effectively restored valve competence with very satisfactory long-term results and a low rate of moderate or greater TR recurrence.

A Novel Transcatheter Device for the Edge-to-Edge Treatment of Tricuspid Regurgitation: A Preliminary Evaluation

Tricuspid regurgitation (TR) is the most common pathology of the tricuspid valve (TV), with significant mortality in severe cases. A well-established strategy to treat TR is represented by the clover surgical technique, which consists of stitching together the free edges of TV leaflets, producing a clover-shaped valvular orifice. Transcatheter treatments for TR constitute a valuable alternative for high-risk patients. In this work we investigated haemodynamic performances and safety of a novel device (StarTric device (STD)) aiming to perform the clover technique via percutaneous access. To assess haemodynamic performances, STD and clover were applied on porcine pathological TVs and tested. Fluid dynamic indexes of both strategies were compared to the pathological model. To evaluate device safety, forces exchanged between device and leaflets were compared to the extraction force (EF) required to STD to completely pass through the leaflet. Clover technique and STD induced a comparable TV backflow reduction (48% and 47%, respectively), with associated increase of TV flow in all tested conditions. Diastolic transvalvular pressure similarly increased indicating a reduction, though not significant, of the valvular orifice. Forces ranged from 1N to 1.71N, compared to an EF of 22.16 ± 8.6N. Force varied significantly amongst different working conditions (normotensive, mild, and severe hypertensive) for each leaflet, whilst no significative variation was found on different leaflets in the same working condition. In the adopted experimental scenario, STD demonstrated comparable efficacy to the surgical strategy in restoring TV haemodynamic. The forces acting on the leaflets following STD implantation were far lower when compared to EFs.

Unveiling Sex Differences in Tricuspid Valve Disease: A Systematic Review and Meta-Analysis of Surgical Management

Tricuspid regurgitation (TR) is a heart condition where blood flows backward through the tricuspid valve. Tricuspid valve disease constitutes a major valvular heart condition that is receiving heightened attention due to tailored treatment options and sex-specific differences in treatment outcomes. The study aims to investigate whether biological sex has a significant influence on the development, progression, and treatment outcomes of tricuspid valve disease in adults. We conducted a comprehensive search to identify studies examining the impact of sex on the pathophysiology of TR as well as treatment outcomes in patients with TR. We searched PUBMED/MEDLINE, SCOPUS, and Excerpta Medica dataBASE (EMBASE) from inception to September 2023 to identify relevant studies. Twelve studies totaling 22,574 patients met our eligibility criteria. These studies were categorized into three subgroups: patients with TR without intervention (3,848 patients, with 48.1% males and 51.9% females), those who underwent open heart surgery (17,498 patients: 46.2% males and 53.8% females), and those who underwent transcatheter tricuspid valve repair/replacement (TTVR; 1,687 patients: 41.6% males and 58.4% females). Analysis revealed no major differences in terms of TR etiology. Males tended to have a slightly lower mean age difference (mean difference (MD): -0.60 years; 95% confidence interval (CI) (-1.49, -0.04); p = 0.10) but had more frequent chronic lung disease (risk ratio (RR): 1.12, 95% CI (1.01, 1.25), p = 0.03). Males showed higher baseline TR volume (MD: 4.11, 95% CI (0.53, 7.68), p = 0.02) and lower left ventricular ejection fraction (MD: -5.85, 95% CI (-6.97, -4.73), p < 0.00001). Following open heart surgery for TR treatment, males required more frequent permanent pacemaker implantation (PPM; RR: 1.57, 95% CI (1.21, 2.03), p = 0.0006). Similarly, TTVR showed a higher need for PPM in males (RR: 1.45, 95% CI (1.10, 1.93), p = 0.010). In-hospital mortality exhibited no sex differences, but males had a slightly elevated late mortality risk. Sex differences in TR patients were notable in baseline characteristics, with males having a higher risk of certain conditions. The more frequent requirement for PPM was a major sex-based difference in terms of prognosis.

Tricuspid Edge-to-Edge Repair Versus Tricuspid Valve Replacement for Severe Tricuspid Regurgitation

BACKGROUND AND OBJECTIVES

Tricuspid valve (TV) repair techniques other than annuloplasty remain challenging and frequently end in tricuspid valve replacement (TVR) in complicated cases. However, the results of TVR are suboptimal compared with TV repair. This study aimed to evaluate the clinical effectiveness of TV edge-to-edge repair (E2E) compared to TVR for severe tricuspid regurgitation (TR).

METHODS

We retrospectively reviewed 230 patients with severe TR who underwent E2E (n=139) or TVR (n=91) from 2001 to 2020. Clinical and echocardiographic results were analyzed using inverse probability of treatment weighting analysis and propensity score matching.

RESULTS

The two groups showed no significant differences in early mortality and morbidities. During the mean follow-up of 106.2±68.8 months, late severe TR and TV reoperation rates were not significantly different between groups. E2E group, however, showed better outcomes in overall survival (p=0.023), freedom from significant tricuspid stenosis (TS) (trans-tricuspid pressure gradient ≥5 mmHg, p=0.021), and freedom from TV-related events (p<0.001). Matched analysis showed consistent results.

CONCLUSIONS

E2E for severe TR presented more favorable clinical outcomes than TVR. Our study supports that E2E might be a valuable option in severe TR surgery, avoiding TVR.

1-Year Outcomes of Transcatheter Tricuspid Valve Repair

BACKGROUND

Surgical management of isolated tricuspid regurgitation (TR) is associated with high morbidity and mortality, thereby creating a significant need for a lower-risk transcatheter solution.

OBJECTIVES

The single-arm, multicenter, prospective CLASP TR (Edwards PASCAL TrAnScatheter Valve RePair System in Tricuspid Regurgitation [CLASP TR] Early Feasibility Study) evaluated 1-year outcomes of the PASCAL transcatheter valve repair system (Edwards Lifesciences) to treat TR.

METHODS

Study inclusion required a previous diagnosis of severe or greater TR and persistent symptoms despite medical treatment. An independent core laboratory evaluated echocardiographic results, and a clinical events committee adjudicated major adverse events. The study evaluated primary safety and performance outcomes, with echocardiographic, clinical, and functional endpoints. Study investigators report 1-year all-cause mortality and heart failure hospitalization rates.

RESULTS

Sixty-five patients were enrolled: mean age of 77.4 years; 55.4% female; and 97.0% with severe to torrential TR. At 30 days, cardiovascular mortality was 3.1%, the stroke rate was 1.5%, and no device-related reinterventions were reported. Between 30 days and 1 year, there were an additional 3 cardiovascular deaths (4.8%), 2 strokes (3.2%), and 1 unplanned or emergency reintervention (1.6%). One-year postprocedure, TR severity significantly reduced (P < 0.001), with 31 of 36 (86.0%) patients achieving moderate or less TR; 100% had at least 1 TR grade reduction. Freedom from all-cause mortality and heart failure hospitalization by Kaplan-Meier analyses were 87.9% and 78.5%, respectively. Their New York Heart Association functional class significantly improved (P < 0.001) with 92% in class I or II, 6-minute walk distance increased by 94 m (P = 0.014), and overall Kansas City Cardiomyopathy Questionnaire scores improved by 18 points (P < 0.001).

CONCLUSIONS

The PASCAL system demonstrated low complication and high survival rates, with significant and sustained improvements in TR, functional status, and quality of life at 1 year. (Edwards PASCAL TrAnScatheter Valve RePair System in Tricuspid Regurgitation [CLASP TR] Early Feasibility Study [CLASP TR EFS]; NCT03745313).

Surgical edge-to-edge repair for tricuspid regurgitation: Impact of the concomitant annuloplasty

BACKGROUND

Surgical edge-to-edge repair has been suggested for tricuspid regurgitation (TR) with complex tricuspid valve (TV) pathologies. Nevertheless, the impact of concomitant TAP has not been well established. This study aimed to compare the outcomes of tricuspid edge-to-edge repair according to the implementation of concomitant TAP.

METHODS

A total of 264 patients who underwent tricuspid edge-to-edge repair between January 2001 and December 2020 were enrolled in the study, and 23 patients who had undergone previous TV repair were excluded. The remaining 241 patients were categorized into two groups: TAP (n = 190) and non-TAP (n = 51). Inverse probability of treatment weighting (IPTW) was used to adjust the baseline differences between the two groups.

RESULTS

Early mortality and morbidity did not differ between the two groups. The mean follow-up duration was 111.5 ± 72.4 months. IPTW-adjusted survival analysis did not reveal a difference between the two groups in late significant tricuspid stenosis (trans-tricuspid pressure gradient ≥5 mmHg) and TV reoperations. However, freedom from overall mortality and late severe TR were significantly higher in the TAP group (p = 0.033 and 0.006, respectively). The sensitivity analysis, including propensity score matching, showed consistent results.

CONCLUSION

The long-term outcomes of surgical tricuspid edge-to-edge repair were better when performed with concomitant TAP.

Chordae Tendineae Approximation Technique for Severe Tricuspid Regurgitation with Severe Leaflet Tethering Using a Totally Endoscopic Beating-Heart Strategy: A Case Report

Untreated severe tricuspid regurgitation (TR) is associated with poor outcomes. Functional TR occurs secondary to dilatation of the annulus and tethering of the leaflets. Ring annuloplasty alone can correct most cases, but is insufficient in cases of severe annular dilatation due to severe leaflet tethering. In such cases, a tricuspid edge-to-edge technique may be an option. However, stitching of the leaflet tips alone is likely to result in tearing of the leaflets. Approximation of the durable chordae tendineae is considered helpful for this problem. Herein, we present the case of a 39-year-old man who had undergone openheart surgery for acute type A aortic dissection 13 months earlier. A right mini-thoracotomy approach with a beating-heart strategy was used, which did not require unnecessary pericardial adhesiolysis and dissection. This technique had the advantage of reducing the operation time and the risk of bleeding. To summarize, we present a case of tricuspid valve repair in a high-risk patient with severe leaflet tethering that was successfully managed using these methods.

Traumatic avulsion of the tricuspid valve: an unusual cardiac complication of an equine accident

A stablehand in his 20s presented with increasing dyspnoea on exertion and chest pain months after being kicked directly in the chest by a horse. Further investigations revealed severe isolated, primary tricuspid regurgitation due to partial avulsion of the anterior leaflet. Open surgical repair was successfully performed from which he recovered uneventfully with resolution of his symptoms and minimal residual tricuspid regurgitation. Although uncommon, blunt force trauma to the chest is becoming increasingly recognised as a rare cause of tricuspid regurgitation. Symptoms may be insidious, and a high index of suspicion is required to avoid missing the diagnosis.

Transcatheter tricuspid valve repair and replacement: a landscape review of current techniques and devices for the treatment of tricuspid valve regurgitation

Background and ObjectiveTricuspid regurgitation is a prevalent and undertreated cardiac pathology impacting millions across the globe. While historically surgical interventions for isolated tricuspid regurgitation were largely avoided due to data citing poor surgical outcomes, advances in transcatheter techniques and imaging modalities have reframed the approach to tricuspid valve disease in promising new ways.MethodsHere we sought to provide a landscape review of the current state of the field for transcatheter tricuspid valve interventions. We first start with a descriptive overview of the tricuspid valve, reviewing the anatomy, imaging characteristics, and the current guidelines for tricuspid interventions. We then review both transcatheter valve repair and valve replacement modalities, highlighting the devices, techniques, and valves currently under investigation, summarizing available outcomes data for each modality when possible.Results and ConclusionOur aim in writing this landscape review is the create an all-encompassing, up-to-date resource for clinicians to refer to when seeking to learn about the current state of transcatheter tricuspid valve interventions. We also hope to highlight the exciting promise of transcatheter tricuspid valve replacement in appropriate patients, and review the valves currently under development for use in the tricuspid position.

Long-term Clinical and Hemodynamic Outcomes of Edge-to-Edge Repair for Tricuspid Regurgitation

BACKGROUND

The edge-to-edge technique (Alfieri stitch) has been widely adopted in mitral valve but not tricuspid valve (TV) repair. We evaluated long-term clinical and hemodynamic outcomes of tricuspid edge-to-edge repair.

METHODS

We retrospectively reviewed 237 patients (mean age, 58.4 ± 13.9 years) who had undergone tricuspid edge-to-edge repair from January 2001 to March 2019 in our institution. Tricuspid annuloplasty was performed in 175 patients (73.8%) using ring (91 [38.4%]) or suture (84 [35.4%]) annuloplasty. Concomitant procedures were mitral valve replacement (133 [56.1%]), mitral valve repair (52 [21.9%]), aortic valve replacement (41 [17.3%]), and maze operation (138 [58.2%]).

RESULTS

Postoperative echocardiography revealed mild or less tricuspid regurgitation (TR) in 220 patients (92.8%). Early mortality (<30 days) occurred in 9 patients (3.8%), reoperation for bleeding in 16 (6.8%), and low cardiac output syndrome in 15 (6.4%). Freedom from all-cause mortality was 87.2% at 5 years and 80.6% at 10 years. Freedom from moderate or severe TR was 97.1% at 5 years and 84.9% at 10 years. Transtricuspid pressure gradient was 3.8 ± 4.2 mm Hg at discharge and 3.2 ± 5.6 mm Hg at the last follow-up (P = .60). Freedom from significant tricuspid stenosis (transtricuspid pressure gradient ≥5 mm Hg) was 96.4% and 88.4% at 5 and 10 years, respectively. There was 1 early TV reoperation for severe TR on postoperative day 3 (0.4%). Freedom from TV reoperation was 99.1% at 10 years.

CONCLUSIONS

Tricuspid edge-to-edge repair showed acceptable long-term clinical and hemodynamic results and is an effective and safe option in TV surgery.

Functional tricuspid regurgitation: indications, techniques, and outcomes

Functional tricuspid regurgitation (TR) results from asymmetric dilation of the tricuspid valve annulus. This often occurs due to right ventricular enlargement and dysfunction as a consequence of myocardial or valvular abnormalities of the left heart. Even mild TR at the time of left-sided valvular surgery may worsen postoperatively, which carries poor prognostic implications. In spite of data revealing poor outcomes associated with residual TR, surgery for functional TR remains underutilized. Surgical repair techniques for TR include placement of a rigid or semi-rigid tricuspid annular ring, which has been shown to provide superior longevity compared with suture and flexible band repair techniques. Additionally, emerging percutaneous annuloplasty techniques to correct functional TR can expand interventional treatment options to patients who would otherwise carry prohibitive operative risk.

New Insights into Valve Hemodynamics

Heart valve diseases are common disorders with five million annual diagnoses being made in the United States alone. All heart valve disorders alter cardiac hemodynamic performance; therefore, treatments aim to restore normal flow. This paper reviews the state-of-the-art clinical and engineering advancements in heart valve treatments with a focus on hemodynamics. We review engineering studies and clinical literature on the experience with devices for aortic valve treatment, as well as the latest advancements in mitral valve treatments and the pulmonic and tricuspid valves on the right side of the heart. Upcoming innovations will potentially revolutionize treatment of heart valve disorders. These advancements, and more gradual enhancements in the procedural techniques and imaging modalities, could improve the quality of life of patients suffering from valvular disease who currently cannot be treated.

Effectiveness of Artificial Neochordae Implantation in Tricuspid Valve Repair

Various techniques for treating tricuspid regurgitation have been described; however, because of scarce data about the long-term outcomes of different repairs, the optimal technique has not been established. We evaluated the effectiveness and durability of artificial neochordae implantation in the treatment of tricuspid regurgitation. From 2009 through 2014, 507 patients underwent tricuspid valve repair at our institution. Of those, 48 patients implanted with artificial neochordae were included in our study. The median age of the participants was 62 years (range, 4-77 yr) and 50% were women. Thirty patients (63%) were in New York Heart Association functional class III, and 11 (23%) were in class II. The cause of tricuspid regurgitation was functional in 33 patients (69%) and rheumatic in 15 (31%). In 46 patients, neochordae implantation was performed in addition to Kay annuloplasty (n=13) or ring annuloplasty (n=33). Forty-two patients were discharged from the hospital with absent or mild tricuspid regurgitation. The mean follow-up period was 44.3 ± 20.2 months. Follow-up echocardiograms revealed that tricuspid regurgitation was absent, minimal, or mild in 38 patients (80.8%), moderate in 7, and severe in 2. Our results indicate that the use of artificial neochordae implantation as an adjunct procedure to annuloplasty leads to effective and durable repair in comparison with conventional techniques for treating tricuspid regurgitation.

Mechanics of the Tricuspid Valve-From Clinical Diagnosis/Treatment, In-Vivo and In-Vitro Investigations, to Patient-Specific Biomechanical Modeling

Proper tricuspid valve (TV) function is essential to unidirectional blood flow through the right side of the heart. Alterations to the tricuspid valvular components, such as the TV annulus, may lead to functional tricuspid regurgitation (FTR), where the valve is unable to prevent undesired backflow of blood from the right ventricle into the right atrium during systole. Various treatment options are currently available for FTR; however, research for the tricuspid heart valve, functional tricuspid regurgitation, and the relevant treatment methodologies are limited due to the pervasive expectation among cardiac surgeons and cardiologists that FTR will naturally regress after repair of left-sided heart valve lesions. Recent studies have focused on (i) understanding the function of the TV and the initiation or progression of FTR using both in-vivo and in-vitro methods, (ii) quantifying the biomechanical properties of the tricuspid valve apparatus as well as its surrounding heart tissue, and (iii) performing computational modeling of the TV to provide new insight into its biomechanical and physiological function. This review paper focuses on these advances and summarizes recent research relevant to the TV within the scope of FTR. Moreover, this review also provides future perspectives and extensions critical to enhancing the current understanding of the functioning and remodeling tricuspid valve in both the healthy and pathophysiological states.

Surgical Techniques for Tricuspid Valve Disease

Tricuspid valve disease affects millions of patients worldwide. It has always been considered less relevant than the left-side valves of the heart, but this “forgotten valve” still represents a great challenge for the cardiac surgeons, especially in the most difficult symptomatic scenarios. In this review we analyze the wide spectrum of surgical techniques for the treatment of a diseased tricuspid valve.

Percutaneous tricuspid valve therapies: the new frontier

Moderate-to-severe tricuspid regurgitation (TR) affects ∼1.6 million patients in the USA, of whom only 8000 undergo tricuspid surgery annually; this results in an extremely large number of untreated patients with significant TR. Therefore, there is a large unmet clinical need for patients with severe TR who are not referred for conventional surgery, mainly due to expected high surgical risk. Percutaneous procedures are an attractive alternative to surgery for patients deemed to be high-risk surgical candidates. Whereas over the past few years, the development and clinical use of percutaneous approaches to the aortic valve and mitral valve have been widespread, few data are available about the feasibility and the efficacy of the percutaneous tricuspid valve treatment. This review will explore the available technologies, which are today under evaluation and the preliminary clinical results.

Ex vivo hydrodynamics after central and paracommissural edge-to-edge technique: A further step toward transcatheter tricuspid repair?

OBJECTIVES

Transcatheter approaches in heart valve disease became tremendously important and are currently established in the aortic position, but transcatheter tricuspid repair is still in its beginning and remains challenging. Replicating the surgical edge-to-edge technique, for example, with the MitraClip System (Abbott Vascular, Santa Clara, Calif), represents a promising option and has been reported successfully in small numbers of cases. However, up to now, few data considering the edge-to-edge technique as a transcatheter approach are available. This study aims to determine the ex vivo hydrodynamics after the central and paracommissural edge-to-edge technique in different pathologies.

METHODS

Because of basal or apical dislocation of papillary muscles, leaflet prolapse or tethering was simulated in porcine tricuspid valves mounted on a flexible holding device. Central and paracommissural edge-to-edge techniques were evaluated successively in these pathologies. Regurgitant volume and mean transvalvular gradient were determined in a pulse duplicator.

RESULTS

In this ex vivo model, the isolated edge-to-edge technique reduced tricuspid regurgitation. In the prolapse model, regurgitant volume decreased significantly after central edge-to-edge technique (from 49.4 ± 13.6 mL/stroke to 39.3 ± 14.1 mL/stroke). In the tethering model, both the central and the paracommissural edge-to-edge techniques led to a significant decrease (from 48.7 ± 13.9 to 43.6 ± 15.6 and to 41.1 ± 13.8 mL/stroke). In all cases, the reduction of regurgitant volume was achieved at the cost of significantly increased mean transvalvular gradient.

CONCLUSIONS

This study provides a reduction of tricuspid regurgitation after the edge-to-edge technique in the specific experimental setup. Whether this reduction is sufficient to treat tricuspid regurgitation successfully in clinical practice remains to be established. Transcatheter approaches need to be evaluated further, probably with regard to concomitant annuloplasty for higher reduction of tricuspid regurgitation.

First transfemoral percutaneous edge-to-edge repair of the tricuspid valve using the MitraClip system

AIMS

While severe tricuspid regurgitation contributes significantly to morbidity and a poor prognosis in heart failure patients, isolated surgical repair of the tricuspid valve is associated with a high mortality, especially in patients with prior surgery. Percutaneous tricuspid valve repair could contribute to the solution of this dilemma. A recently published report demonstrated the feasibility of tricuspid edge-to-edge repair with the MitraClip® system (Abbott Vascular, Santa Clara, CA, USA) using a transjugular route. In a highly symptomatic patient with severe functional tricuspid regurgitation unsuitable for surgery, we aimed to reduce tricuspid regurgitation using a modified deployment technique for the MitraClip system using a femoral access.

METHODS AND RESULTS

A 78-year-old male patient with dilated cardiomyopathy was admitted for his fifth episode of acutely decompensated, predominantly right-sided, heart failure in ten months. Echocardiography showed a moderately to severely reduced left ventricular function and severe functional tricuspid regurgitation. Two clips were deployed in the anterior-septal and posterior-septal commissure of the tricuspid valve, resulting in a significant reduction of the effective regurgitant orifice area. The midterm clinical state of the patient improved.

CONCLUSIONS

In our patient with severe functional tricuspid regurgitation and suitable anatomy, transfemoral percutaneous tricuspid valve repair was technically feasible and safe by using a modified deployment technique of a widely used repair system developed for the mitral valve. The procedure can be performed without technical modification of the device via a transfemoral route and under echocardiographic guidance. However, particular anatomic and technical aspects can compromise an initial procedural success and demand specific considerations in the future.

Diagnosis and treatment of tricuspid valve disease: current and future perspectives

The assessment and management of tricuspid valve disease have evolved substantially during the past several years. Whereas tricuspid stenosis is uncommon, tricuspid regurgitation is frequently encountered and is most often secondary in nature and caused by annular dilatation and leaflet tethering from adverse right ventricular remodelling in response to any of several disease processes. Non-invasive assessment of tricuspid regurgitation must define its cause and severity; advanced three-dimensional echocardiography, MRI, and CT are gaining in clinical application. The indications for tricuspid valve surgery to treat tricuspid regurgitation are related to the cause of the disorder, the context in which it is encountered, its severity, and its effects on right ventricular function. Most operations for tricuspid regurgitation are done at the time of left-sided heart valve surgery. The threshold for restrictive ring annuloplasty repair of secondary tricuspid regurgitation at the time of left-sided valve surgery has decreased over time with recognition of the risk of progressive tricuspid regurgitation and right heart failure in patients with moderate or lesser degrees of tricuspid regurgitation and tricuspid annular dilatation, as well as with appreciation of the high risks of reoperative surgery for severe tricuspid regurgitation late after left-sided valve surgery. However, many patients with unoperated severe tricuspid regurgitation are also deemed at very high or prohibitive surgical risk. Novel transcatheter therapies have begun to emerge for the treatment of tricuspid regurgitation in such patients. Experience with such therapies is preliminary and further studies are needed to determine their role in the management of this disorder.

Annulus Tension on the Tricuspid Valve: An In-Vitro Study

Annulus tension (AT) is defined as leaflet tension per unit length of the annulus circumference. AT was investigated to understand tricuspid valve (TV) annulus mechanics. Ten porcine TVs were mounted on a right ventricle rig with an annulus plate to simulate TV closure. The TVs were mounted on the annulus plate in a normal and dilated TV annulus sizes, and closed under transvalvular pressure of 40 mmHg with the annulus held peripherally by wires. Anterior papillary muscle (PM) and septal PM were displaced in the dilated annulus. Wire forces were measured, and ATs (N/m) were calculated. Clover repair was performed in the dilated TV state subsequently, and AT was calculated again. A one-way ANOVA and Tukey's HSD test were used to test significances between the different TV states along each annulus segment with p < 0.05. Average ATs for the normal annulus, dilated annulus, and clover repair were 10.75 ± 1.87, 28.81 ± 10.51, and 26.93 ± 11.44 N/m, respectively. Septal annulus segments had the highest ATs when compared to the other segments. For the clover repair, there were no significant changes in AT values. ATs and leaflet forces increased roughly 3-4 times with annulus dilation. AT decelerates annulus dilation as previously shown in the mitral valve. Clover repair does not prevent further annulus dilation by AT change and should be accompanied by annuloplasty. AT improves annulus contraction during a cardiac cycle and should be considered when designing annuloplasty in the future.

Management of tricuspid regurgitation

Secondary tricuspid regurgitation is the most frequent type of tricuspid insufficiency in western countries. Its surgical treatment is still an object of debate both in terms of timing and surgical techniques. Until recently, the avoidance of surgery for tricuspid repair was commonly accepted in patients with less than severe secondary tricuspid regurgitation undergoing left-sided valve surgery. More recently, compelling evidence in favour of a more aggressive surgical approach in this setting has emerged. The surgical technique should be tailored to the stage of disease. Ring annuloplasty is more durable than suture annuloplasty and represents the method of choice in the presence of isolated annular dilatation. In patients in whom the dilatation of the tricuspid annulus is combined with significant leaflet tethering, annuloplasty alone is unlikely to be durable and additional procedures have been proposed in order to achieve a more durable repair. In this review, pathophysiology, surgical indications, techniques of repair and outcomes of secondary tricuspid regurgitation will be discussed. We will also focus on the challenging issue of significant tricuspid regurgitation occurring late after left-sided valve surgery. Finally, the current and future role of percutaneous tricuspid valve technologies will be briefly described.

The growing clinical importance of secondary tricuspid regurgitation

Functional or secondary tricuspid regurgitation (STR) is the most frequent etiology of tricuspid valve pathology in Western countries. Surgical tricuspid repair has been avoided for years, because of the misconception that tricuspid regurgitation should disappear once the primary left-sided problem is treated; this results in a large number of untreated patients with STR. Over the past few years, many investigators have reported evidence in favor of a more aggressive surgical approach to STR. Consequently, interest has been growing in the physiopathology and treatment of STR. The purpose of this review is to explore the anatomical basis, pathophysiology, therapeutic approach, and future perspectives with regard to the management of STR.

Absence of posterior tricuspid valve leaflet and valve reconstruction

We report a rare case of the absence of a posterior tricuspid valve leaflet. A male patient, aged 46, suffering from severe tricuspid valve regurgitation (TR) of unknown aetiology and atrial septal aneurysm was referred to our hospital for surgery. On surgical inspection, the posterior tricuspid valve leaflet and its subvalvular apparatus were completely absent and only the valve annulus was seen in the corresponding position. The anterior and septal leaflets were normal. We successfully reconstructed the tricuspid valve as follows: the head of an anterior papillary muscle was approximated to the ventricular septum (Sebening stitch). After the approximation of the centre of the tricuspid annulus of the anterior leaflet to the tricuspid annulus on the opposite side, a sizer of 29 mm in diameter was easily passed through the anterior orifice. The posterior orifice was closed with running sutures (posterior annulorrhaphy after Hetzer). Before these procedures, we attempted to reconstruct the tricuspid valve with a posterior annulorrhaphy alone; however, valve competence was insufficient. A Sebening stitch was necessary to improve the valve competence. Echocardiography showed TR grade 1 at the patient's discharge from hospital and TR grade 1 to 2 at the follow-up, 10 months after the operation.

Evolving indications for tricuspid valve surgery

More attention has been paid to the mitral valve (MV) than the tricuspid valve (TV), and this relative paucity of data has led to confusion regarding the timing of TV surgery. We review the American College of Cardiology/American Heart Association and European Society of Cardiology guidelines to identify areas of concordance (severe tricuspid regurgitation [TR] in a patient undergoing mitral valve surgery); discordance (less than severe TR but with markers for late TR recurrence such as pulmonary hypertension, a dilated TV annulus, atrial fibrillation, permanent transtricuspid pacing wires and others); and disagreement (surgery for primary TR). We provide our perspective from Northwestern University on these issues and where the guidelines are silent (TR in patients undergoing non-mitral valve operations). Finally, we review recent publications on the results of TV repair and replacement. Although there have been scant publications in the past, there have been more useful publications in recent years to guide our decision making.

Valve repair for functional tricuspid valve regurgitation: anatomical and surgical considerations

Functional tricuspid regurgitation (TR) primarily arises from asymmetric dilation of the tricuspid annulus in the setting of right ventricular dysfunction and enlargement in response to left-sided myocardial and valvular abnormalities. Even if TR is not severe at the time of mitral valve surgery, TR can worsen and even appear late after successful mitral valve surgery, which portends a poor prognosis. Despite data demonstrating inferior outcomes in the presence of residual TR, surgical repair for functional TR remains underused. However, "benign neglect" of TR, especially in the presence of tricuspid annular dilation, is unacceptable. Surgical repair should consist of placement of a rigid or semirigid annular ring, which has been shown to provide superior durability compared with suture and flexible band-based therapies. Finally, minimally invasive and percutaneous approaches for correcting functional TR may increase the delivery of therapy and allow treatment of patients with recurrent TR at high risk for reoperation.