Severe tricuspid regurgitation with chordae tendinae rupture in CABG surgery.

A 58-year-old male patient was admitted with chest pain and was diagnosed with coronary heart disease. He was scheduled for coronary artery bypass grafting (CABG) under cardiopulmonary bypass (CPB). Intraoperative real-time transesophageal echocardiography (TEE) showed that the tricuspid valves were well-aligned and subtle regurgitation. Real-time TEE after separation from CPB showed severe tricuspid regurgitation and prolapsed chordae tendineae. The tricuspid chordae tendineae rupture due to a right atrial venous return cannula. The use of negative pressure to improve venous drainage during CPB may result in the tricuspid valve being adsorbed to the cannula, increasing the likelihood of injury to the tricuspid valve.

Combination of an extremely rare and a common congenital valvular anomalies: Accessory mitral valve chordae from left atrium and bicuspid aortic valve.

Accessory chordae tendineae is an extremely rare anomaly. In this case report, we described a 61-year-old female patient newly diagnosed with the combination of an accessory mitral valve chordae extending from left atrium which is an extremely rare congenital anomaly and a bicuspid aortic valve. In our patient, three-dimensional echocardiography showed incremental value over two-dimensional echocardiography in the assessment of the exact localization and the extend of accessory chordea.

Feasibility of concomitant exclusion of left atrial appendage during novel transapical off-pump beating heart mitral valve repair.

The AtriClip device enables the safe and reproducible epicardial clipping of the left atrial appendage. Transapical off-pump beating heart mitral valve repair using NeoChord DS100 Artificial Chordae Delivery System has matured and become more standardized. We aim to evaluate the feasibility of combining NeoChord repair and left atrial appendage exclusion in a single procedure through the same minithoracotomy in patients with mitral valve prolapse and atrial fibrillation. From 2018 to 2019, seven patients with severe mitral regurgitation and atrial fibrillation underwent transesophageal echocardiography-guided transapical off-pump mitral valve repair with the novel NeoChord DS 1000 system and concomitant left atrial appendage exclusion using the AtriClip Pro II device. Both procedures were performed via left mini-thoracotomy. The AtriClip device was applied after the NeoChord repair was done. All seven patients had less than moderate mitral regurgitation after the NeoChord repair and successful left atrial appendage occlusion. There were no device or procedure-related complications. Clinical follow-up revealed significant symptomatic improvement, and no cardiovascular complications were reported. Transesophageal echocardiography at 6-12 months post-procedure showed stable left atrial appendage occlusion with no residual flow between the left atrium and the left atrial appendage and a stump of less than 5 mm. Beating heart epicardial clipping of the left atrial appendage using AtriClip concomitant with transapical mitral valve repair using Neochord DS 1000 system is a feasible and safe treatment option in mitral valve prolapse and atrial fibrillation in patients with limited indications. However, its safety needs to be confirmed in a larger series of patients.

Feasibility Study of a Novel Transapical Chordal Implantation System in a Porcine Model.

Transapical beating-heart mitral repair with chordal implantation system has been considered as an alternative treatment for degenerative mitral regurgitation. This study aimed to assess the feasibility and safety of the E-Chord system (Med-Zenith Medical, Beijing, China) for transapical beating-heart mitral valve repair in a porcine model. Artificial chordae were transapically implanted on the mitral valves of 12 anesthetized pigs under epicardial echocardiographic guidance and secured outside the left ventricular apex. The study endpoints included procedural success, device durability, and tissue response to the device. The procedural success rate was 100% (12/12). All animals were implanted with E-Chord in the anterior and posterior leaflets, respectively, and survived uneventfully until euthanized as planned. During the 180-day follow-up, no animal had significant mitral valve dysfunction. The gross observation showed no evidence of anchor detachment and chordal rupture, and there was no obvious damage or changes to mitral leaflets. Microscopic evaluation revealed that the endothelialization of anchor and chordae was completed 90 days after implantation and there was no evidence of chordal rupture, thrombosis, or infection during the 180-day follow-up. The E-Chord system was found to be feasible and safe for heart-beating mitral chordal implantation in a porcine model. The findings of this study suggest that the E-Chord system may be a potential alternative for the treatment of degenerative mitral regurgitation in humans.

Muscularization of the chordae tendinea of the mitral anterior papillary muscle.

The chordae tendineae, described as fibro-collagenous structures, support the leaflets of the atrioventricular valves of the heart in various ways. The chordae tendineae are composed of collagen and elastic fibers. They connect to the ventricular side of the valve leaflets' free border and hinder the leaflets from swinging back into the atrial cavity during systole. Mitral valve chordae tendineae have been classified using a variety of classification systems. To our knowledge, we report a variant chordae tendinea that has yet to be described in the literature. The variant, present only on the mitral anterior papillary muscle, did not show the characteristic appearance of the chorda tendineae. Muscular fibers were observed extending from a larger than usual mitral anterior papillary muscle, inserting into the rough zone of the anterior leaflet. Several tendinous primary and secondary true leaflet chordae emerge from the apical portion of the anterior papillary muscle, inserting into the anterior leaflet's free edge and rough zone. Contraction of this muscular chorda during systole could disrupt the mechanics of valvular closure and result in possible regurgitation across the mitral valve. Additionally, this structure may be subject to rupture during myocardial infarction, leading to valvular dysfunction. The developmental connection between the chordae and papillary muscles could explain the anomalous muscularization of the chordae tendineae observed in this case.

[Supra-annular Mitral Valve Replacement Using a Composite Valve for an Infant with Acute Rupture of Chordae Tendineae].

Acute rupture of the chordae tendineae of the mitral valve could lead to severe mitral regurgitation and circulatory collapse in infants. Mitral valve replacement may be often challenging because of the valve-annulus size mismatch in small infants when mitral valve repair cannot be accomplished. We present an infant with acute massive rupture of the chordae tendineae of the mitral valve who successfully underwent supra-annular mitral valve replacement using the short composite valve of an expanded polytetrafluoroethylene( ePTFE) graft and a mechanical valve. His mechanical valve has been functioning without complications such as thrombosis and pulmonary venous obstruction for 20 months after surgery. This technique could be helpful even infants with acute rupture of the chordae tendineae of the mitral valve whose left atrium may not be dilated.

Structural properties in ruptured mitral chordae tendineae measured by synchrotron-based X-ray phase computed tomography.

The link between the structural properties and the rupturing of chordae tendineae in the mitral valve complex is still unclear. Synchrotron-radiation-based X-ray phase computed tomography (SR-XPCT) imaging is an innovative way to quantitatively analyze three-dimensional morphology. XPCT has been employed in this study to evaluate the chordae tendineae from patients with mitral regurgitation and to analyze structural changes in the ruptured chordae tendineae in patients with this condition. Six ruptured mitral chordae tendineae were obtained during surgical repairs for mitral regurgitation and were fixed with formalin. In addition, 12 healthy chordae tendineae were obtained from autopsies. Employing XPCT (effective pixel size, 3.5 µm; density resolution, 1 mg cm-3), the density of the chordae tendineae in each sample was measured. The specimens were subsequently analyzed pathologically. The mean age was 70.2 ± 3.0 in the rupture group and 67.2 ± 14.1 years old in the control group (p = 0.4927). All scans of chorda tendineae with SR-XPCT were performed successfully. The mean densities were 1.029 ± 0.004 in the rupture group and 1.085 ± 0.015 g cm-3 in the control group (p < 0.0001). Density based on SR-XPCT in the ruptured mitral chordae tendineae was significantly lower compared with the healthy chorda tendinea. Histological examination revealed a change in the components of the connective tissues in ruptured chorda tendinea, in accordance with the low density measured by SR-XPCT. SR-XPCT made it possible to measure tissue density in mitral chordae tendineae. Low density in mitral chordae tendineae is associated with a greater fragility in ruptured mitral chordae tendineae.

A Computational Pipeline for Patient-Specific Prediction of the Postoperative Mitral Valve Functional State.

While mitral valve (MV) repair remains the preferred clinical option for mitral regurgitation (MR) treatment, long-term outcomes remain suboptimal and difficult to predict. Furthermore, pre-operative optimization is complicated by the heterogeneity of MR presentations and the multiplicity of potential repair configurations. In the present work, we established a patient-specific MV computational pipeline based strictly on standard-of-care pre-operative imaging data to quantitatively predict the post-repair MV functional state. First, we established human mitral valve chordae tendinae (MVCT) geometric characteristics obtained from five CT-imaged excised human hearts. From these data, we developed a finite-element model of the full patient-specific MV apparatus that included MVCT papillary muscle origins obtained from both the in vitro study and the pre-operative three-dimensional echocardiography images. To functionally tune the patient-specific MV mechanical behavior, we simulated pre-operative MV closure and iteratively updated the leaflet and MVCT prestrains to minimize the mismatch between the simulated and target end-systolic geometries. Using the resultant fully calibrated MV model, we simulated undersized ring annuloplasty (URA) by defining the annular geometry directly from the ring geometry. In three human cases, the postoperative geometries were predicted to 1 mm of the target, and the MV leaflet strain fields demonstrated close agreement with noninvasive strain estimation technique targets. Interestingly, our model predicted increased posterior leaflet tethering after URA in two recurrent patients, which is the likely driver of long-term MV repair failure. In summary, the present pipeline was able to predict postoperative outcomes from pre-operative clinical data alone. This approach can thus lay the foundation for optimal tailored surgical planning for more durable repair, as well as development of mitral valve digital twins.

An unusual origin of a papillary muscle of the right ventricle.

Knowledge of anatomical variations of the heart are important to cardiac surgeons, cardiologists, and radiologist. During routine dissection of a 77-year-old male cadaver, we observed an unusual origin of a papillary muscle of the right ventricle arising from the atrioventricular aspect of the moderator band. This papillary muscle was 6.7mm long and 2.6mm wide. It gave rise to two chordae tendineae: one to the inferior (posterior) papillary muscle of the right ventricle and one directly to the inferior (posterior) leaflet of the tricuspid valve. Variants of the internal anatomy of the heart as exemplified in the present case report should be born in mind during image interpretation and invasive procedures of the right ventricle of the heart.

Comparison of early and late postoperative outcomes between chordal reconstruction and quadrangular resection in patients with posterior mitral valve prolapse: a single-center retrospective study.

BACKGROUND: To compare the early and late postoperative outcomes of chordal reconstruction (CR) and quadrangular resection (QR) in patients with posterior mitral valve prolapse (PMPL). METHODS: Between January 2008 and December 2018, 305 patients with PMPL who underwent mitral valve plasty (MVP) were included in this retrospective analysis. The CR and QR procedures were performed in 169 patients (CR group) and 136 patients (QR group), respectively. Early and late postoperative outcomes were compared between the groups. RESULTS: Follow-up was complete in 96.4% (294/305) of patients, with a mean follow-up of 81.2 ± 30.4 months. No 30-day mortality was observed in any of the patients. The success rate of the mitral valve repair was similar in both groups (99.4% vs. 98.5%, P = 0.850). The incidence of early postoperative hemolysis was lower in the CR group than in the QR group (0.00% vs. 3.0%, P = 0.024). Postoperative left ventricular end-diastolic diameter (LVEDD) decreased more significantly in the CR group than in the QR group at 3 months (8.15 [1.30,12.65] vs. 3.25 [- 0.05, 8.75] mm, P < 0.001). During follow-up, the overall survival rates were 95.1% and 94.6% in the CR and QR groups, respectively. The incidence of reoperation for moderate or severe mitral regurgitation (MR) was similar in both groups (4.3% vs.5.4%, P = 0.653), but the time interval between the initial operation and reoperation was shorter in the QR group than in the CR group (84.3 ± 36.1 vs. 120.9 ± 27.6 months, P = 0.026). The LVEDD enlargement was more significant in the QR group than in the CR group (4.5 [3.6, 4.5] vs. 2.4 [1.3, 2.8] mm, P < 0.001). CONCLUSION: CR and QR are effective techniques for patients with PMPL. Both techniques resulted in a low incidence of recurrent MR. However, CR can reduce early postoperative hemolysis and LVEDD more significantly. During the long-term follow-up, reoperations due to recurrent MR were performed at a longer interval after the initial operation. LVEDD expansion was better avoided in the CR group.

Incidental TEE finding of aberrant chordae tendineae insertion into the basal septum.

A 65-year-old female with severe mitral regurgitation presenting for mitral valve replacement was found to have a previously undiagnosed aberrant papillary muscle with thickened chordae tendineae inserting into the basal septum during intra-operative TEE. Despite its anatomic location, there was no evidence that the aberrant papillary muscle was contributing to the mitral regurgitation or causing left ventricular outflow tract (LVOT) obstruction. The aberrant papillary muscle was resected during the operation and the patient was separated from cardiopulmonary bypass without complications.

Artificial chordae for mitral valve repair.

BACKGROUND: Mitral valve repair using expanded polytetrafluoroethylene sutures to replace mitral chordae tendineae is a well-established procedure. However, the incidence of neo-chordae failure causing recurrent mitral regurgitation is not well defined. METHODS: We have reviewed the reported cases of complications after mitral valve repair related to the use of neo-chordae. This study was mainly carried out through PubMed, Medline, and Google Chrome websites. RESULTS: We have identified a total of 26 patients presenting with rupture of polytetrafluoroethylene neo-chordae, mostly being described as isolated cases. Few other cases of recurrent mitral regurgitation with hemolysis were found, where reoperation was not caused by neo-chordal failure but most likely by technical errors. At pathological investigation the findings were substantially similar in all reported cases. The neo-chordae retained their length and pliability, became covered with host tissue and rupture was mainly related to suture size. Mild calcification was observed not interfering with chordal function; chordal infection did never occur. CONCLUSIONS: The use of artificial neo-chordae provides excellent late results with durable mitral valve repair stability. Chordal rupture may occur late postoperatively leading to reoperation because of recurrent mitral regurgitation. Despite its rarity, this potential complication should not be overlooked during follow-up of patients after mitral valve repair using artificial neo-chordae.

Actual perspective on off-pump transapical artificial chord implantation.

Mitral valve repair (MVR) is undisputedly associated with better clinical and functional outcomes than any other type of valve substitute. Conventional mitral valve surgery in dedicated high-volume centers can assure excellent results in terms of mortality and freedom from mitral regurgitation (MR) recurrence but requires cardiopulmonary bypass (CPB) and cardioplegic heart arrest. Trying to replicate the percentage of success of surgical MVR is the aim of all new transcatheter mitral dedicated devices. In particular, transapical beating-heart mitral valve repair by artificial chordae implantation with transesophageal echocardiography guidance is an expanding field. The safety and feasibility of the procedure have already been largely demonstrated with Neochord and more recently with Harpoon systems. Wang et al. present the outcomes of the first-in-human experience using a novel artificial chordae implantation device, the Mitralstitch system. Despite a quite small cohort of only 10 patients treated, 1-year results are satisfying and comparable with the early experience with former devices (4 patients with moderate or more MR recurrence). The comparison with surgical MVR is still unfavorable and requires further studies and significant procedure improvement. However, the device permits the treatment of anterior and posterior leaflets prolapse and performs quite easily edge-to-edge reparation. It will be interesting to evaluate longer follow-up in larger cohorts of patients as well as the possibility to shift to the transfemoral approach.

Acute aortic regurgitation due to fibrous strand rupture.

A 60-year-old male presented with sudden onset chest pain and pulmonary edema. The investigation confirmed torrential aortic regurgitation of a bicuspid valve. At surgery, a ruptured fibrous strand was identified which had been supporting the left-right cusp commissure with loss of attachment to the aortic wall. This case demonstrates that fibrous strands may be present as a supporting structure of the aortic valve, and rupture can be a rare cause of torrential aortic regurgitation, similar in pathogenesis to how it may be associated with acute severe mitral regurgitation and chordae tendineae rupture.

A new technique to adjust the length of artificial chordae during mitral anterior leaflet repair.

BACKGROUND: Length measurement of artificial chordae remains a critical step during mitral valve repair (MVr). The aim of this study is to assess the effectiveness of a new length measuring technique. METHODS: All consecutive patients with anterior leaflet prolapse/flail who underwent MVr using the described method between January 2020 and January 2022 at our institution were included in the analysis. Clinical and transesophageal echocardiography data were collected postoperatively and at 1-year follow-up. The primary outcome was freedom from mitral regurgitation (MR). Secondary outcomes were presentation with New York Heart Association (NYHA) class <2 and leaflet coaptation length ≥10 mm. RESULTS: Of 25 patients, 16 (64%) were males. A total of 15 (60%) had isolated anterior leaflet disease, while 10 (40%) had concomitant posterior involvement. Twenty patients with isolated MR (80%) underwent right anterior mini-thoracotomy, while 5 (20%) with associated valvular or coronary disease underwent sternotomy. The median number of chordae implanted was 2 [1-4]. Postrepair intraoperative MR grade was 0 in 23 patients (92%) and 1 in 2 (8%). Thirty-day mortality was 0%. De novo atrial fibrillation was 20%. At follow-up, mortality was 0%. No patients presented with moderate or severe MR. A total of 22 patients (88%) were in NYHA class I, while 3 (12%) in class II. The coaptation length was 11 ± 1 mm. CONCLUSIONS: The short-term outcomes of the described technique are good with adequate leaflet coaptation in all treated patients. Long-term results are needed to assess the stability and durability of this repair technique.

Mitral valve repair with artificial chords: Tips and tricks.

Mitral valve regurgitation (MR) is a common valvular disorder occurring in up to 10% of the general population. Mitral valve reconstructive strategies may address any of the components, annulus, leaflets, and chords, involved in the valvular competence. The classical repair technique involves the resection of the prolapsing tissue. Chordal replacement was introduced already in the '60, but in the mid '80, some surgeons started to use expanded polytetrafluoroethylene (ePTFE) Gore-Tex sutures. In the last years, artificial chords have been used also using transcatheter approach such as NeoChord DS 1000 (Neochord) and Harpoon TSD-5. The first step is to achieve a good exposure of the papillary muscles that before approaching the implant of the artificial chords. Then, the chords are attached to the papillary muscle, with or without the use of supportive pledgets. The techniques to correctly implant artificial chords are many and might vary considerably from one center to another, but they can be summarized into three big families of suturing techniques: single, running or loop. Regardless of how to anchor to the mitral leaflet, the real challenge that many surgeons have taken on, giving rise to some very creative solutions, has been to establish an adequate length of the chords. It can be established based on anatomically healthy chords, but it is important to bear in mind that surgeons work on the mitral valve when the heart is arrested in diastole, so this length could fail to replicate the required length in the full, beating heart. Hence, some surgeons suggested techniques to overcome this problem. Herein, we aimed to describe the current use of artificial chords in real-world surgery, summarizing all the tips and tricks.

Respect or resect in Barlow disease.

Mitral regurgitation in Barlow disease may still be challenging to be repaired. Most often it involves the posterior leaflet. Many techniques and concepts are currently available; the main goal being to restore a good surface of coaptation. Basic principles such as thorough analysis is still required whatever the approach to assess excess tissue height, width, and prolapse. Nowadays it seems that two different ways of treating mitral prolapse coexist: the nonresection one and the resection one. Both will be discussed and analyzed. Similarly, the use of artificial chordae seems to have a preponderant role to support the free edge and correct a prolapse. Native secondary chord transfer are easy and reliable but seem abandoned by many. Anterior leaflet prolapse is also dealt with and fewer options are available to address this leaflet. Then commissural prolapse is mentioned. It is an important area of the valve which should deserve better treatment than commissuroplasty. Finally, a special entity will be described; mitro annular disjunction. The approach is not or no longer an issue as only good long-term results are important in an era where percutaneous therapy is the only noninvasive technique.

Cutting the second order chords during mitral valve repair.

The chordae tendinae connect the papillary muscles (PMs) to the mitral valve. While the first-order chordae serve to secure the leaflets to maintain valve closure and prevent mitral valve prolapse, the second-order chordae are believed to play a role in maintaining normal left ventricle size and geometry. The PMs, from where the chordae tendinae originate, function as shock absorbers that compensate for the geometric changes of the left ventricular wall. The second-order chordae connect the PMs to both trigons under tension. The tension distributed towards the second-order chordae has been demonstrate to be more than threefold that in their first-order counterpart. Cutting the second-order chordae puts all the tension on the first-order chordae, which are then closer to their rupture point. However, it has been experimentally demonstrated that the tension at which the first-order chordae break is 6.8 newtons (N), by far higher than the maximal tension reached, that is 0.4 N. Even if the clinical reports have been favorable, the importance of cutting the second-order chordae to recover curvature of the anterior leaflet and increase the coaptation length between the mitral valve leaflets has been slowly absorbed by the surgical world. Nevertheless, there are progressive demonstrations that chordal tethering affects the anterior leaflet not only in secondary, but also in primary mitral regurgitation, having a not negligible role in the long-term outcome of mitral repair.

Initial experiences of transapical beating-heart mitral valve repair with a novel artificial chordal implantation device.

BACKGROUND: Severe mitral regurgitation (MR) is associated with progressive heart failure and impairment of survival. Degenerative MR accounts for most MV repair surgeries. Conventional mitral valve repair surgery requires cardiopulmonary bypass and is associated with significant morbidity and risks. Transapical beating-heart mitral valve repair by artificial chordae implantation with transesophageal echocardiography (TEE) guidance has the potential to significantly reduce surgical morbidity. We report the first-in-human experience of degenerative MR repair using a novel artificial chordae implantation device (MitralstitchTM system). METHODS: Ten patients with severe MR underwent transapical artificial chordae implantation using MitralstitchTM system. The procedure was performed through a small left thoracotomy under general anesthesia and TEE guidance. Patients underwent transthoracic echocardiography and other assessments during the follow-up. RESULTS: All 10 patients with an average age of 63.7 ± 9.6 years successfully received transapical artificial chordae implantation. Their MR reduced from severe to none or trace in five patients, mild in five patients before discharge. Five patients received one artificial chordal implantation, four patients received two, and one patient received three and edge-to-edge repair by locking two of them. The safety and efficacy endpoint were achieved in all patients at 1-month follow-up. At 1-year follow-up, six patients had mild MR, three patients had moderate MR, one patient had recurrence of severe MR and underwent surgical repair. CONCLUSIONS: The results of this first-in-human study show safety and feasibility of transapical mitral valve repair using MitralStitch system. Patient selection and technical refinement are crucial to improve the outcomes.

A rare congenital anomaly: Anomalous fibromuscular cord of the left atrium.

BACKGROUND: Left atrial anomalous fibromuscular cord is a rare congenital anomaly, which exists in a small proportion of the general population. Although its clinical significance remains largely unknown, it is generally considered a benign entity. We report a case of incidental finding of left atrial fibromuscular cord without structural cardiac abnormalities or hemodynamic obstruction. METHODS AND RESULTS: A-39-year-old female presented with palpitations for more than 10 years. Electrocardiogram and laboratory tests showed no unremarkable. Transthoracic echocardiography revealed an abnormal linear structure connecting the interatrial septum and the left atrial free wall, color Doppler flow imaging did not show hemodynamic obstruction. Cardiac contrast-enhanced computed tomography images showed the string-like structure associated with calcification, connecting the interatrial septum and the ridge around the orifice of the left inferior pulmonary vein. Sagittal multiplanar reconstructed image showed a dot-like structure located in the left atrial cavity. DISCUSSION: Left atrial anomalous fibromuscular cord is a rare congenital anomaly, which is also known as left atrial anomalous fibromuscular cord, left atrial false tendon, accessory chordae tendineae, or left atrial aberrant band. The clinical significance is unclear. Some cases have been reported that the fibromuscular cord, which do not have pathological significance. It has also been reported that it may be associated with supraventricular arrhythmias, patent foramen ovale, and Chiai's network. In some patients, attachment to the mitral chord can lead to mitral valve insufficiency and murmur. Nevertheless, a detailed understanding the anomalous anatomical characteristics of the anomalous cord may help us to better predict an unexpected difficulty in catheter manipulation, and potential arrhythmogenicity. CONCLUSION: Transthoracic echocardiography and cardiac computed tomography angiography have an important imaging value for the diagnosis of the left atrial anomalous fibromuscular cord, including its origin, course, or whether associated with other cardiovascular malformations.