The standardization of surgical procedures is essential to improve outcomes and offer a predictable and competitive therapeutic alternative. Streamlining these procedures also democratizes them, positioning surgical options as a forward-looking choice aligned with modern advancements. Among cardiac valves, the aortic valve has received most of the surgical innovation over the past decades, culminating in rapid-deployment and/or sutureless prostheses that enabled the expansion of less invasive approaches. Mitral valve repair, in contrast, has shifted towards less invasive approaches but remains largely reliant on adapted instruments to replicate conventional repair techniques. 

Leaving conflicts of interest appart, in modern healthcare, it is evident that the primary R&D thrust across all specialties is largely driven by private funding from the biomedical industry, without involving conflicts of interest. Innovation produces techniques that, with appropriate clinical judgment and training, are applied daily in patient care. Although these innovations may introduce additional costs, we aim to employ them responsibly and with confidence that they can enhance the outcomes of traditional procedures. This creates a feedback loop that strengthens the treatment of a specific pathology or even an entire specialty. While the regulations of this world may unfortunately demand such alignment, diverging from these norms would condemn us to professional obsolescence. This fate looms even closer as our interventional competitors stay attuned to these dynamics, while we risk falling behind if we fail to follow the guidelines shaping cardiac surgery trends internationally. 

The study under review represents the culmination of a one-year follow-up of three devices aimed at simplifying mitral valve repair. These devices are all products from LSI Solutions®, including the well-known titanium clip knotting system COR-KNOT®, as well as lesser-known systems for self-suturing PTFE neochords (Mi-STITCH®) and for mini-clip knotting (Mi-KNOT®). These systems are adaptable to both conventional open approaches and less invasive methods (as described by the authors). The Mi-STITCH® device anchors a neochord loop via two simultaneous suture passes through the free edge of the leaflet and subsequently to the papillary muscle. Its head functions similarly to thoracoscopy systems, with 360º rotation and up to 15º flexion, allowing optimal perpendicularity at the targeted suture sites on the leaflet and papillary muscle. Once the correct chord length is determined, it is secured to the free edge using a titanium mini-clip (Mi-KNOT®). Annuloplasty follows the conventional approach but is simplified by knotting the sutures using the COR-KNOT® system. Studies have shown that up to half or more of the time required for mitral valve repair is spent on annuloplasty suturing, with knotting particularly time-consuming in less invasive approaches. 

The experience, documented in ClinicalTrials.gov, was conducted at a single center with 12 low-surgical-risk patients with primary mitral regurgitation. Cases with flail segments were not excluded, and a total of 29 neochords were implanted. Of these, 2 were entirely removed and 6 were removed but replaced using the same system. Four procedures were performed via minithoracotomy, with 7 patients undergoing additional procedures such as tricuspid valve repair, left atrial appendage closure, surgical ablation, or coronary revascularization. No alternative neochord implantation methods were used, but other repair techniques were applied, including leaflet resection in two cases, Alfieri edge-to-edge suturing in one, and cleft closure in five. This variety was likely due to the absence of a restricted case selection, for example, limited to simple posterior leaflet P2 prolapse repairs. At one-year follow-up, all patients had minimal or mild residual regurgitation at discharge and exhibited good functional status, with only one case showing recurrence of grade 2+ or higher regurgitation. 

The authors conclude that the initial outcomes with automated PTFE suture and titanium knotting systems are highly satisfactory, warranting continued follow-up to assess long-term stability. 

COMMENTARY: 

The experience with LSI Solutions® products is remarkably positive and, with proper training, may further democratize mitral valve repair, even through less invasive approaches. The authors commendably address the inclusion of diverse repair mechanisms in the study, emphasizing that the necessary tools for addressing mitral regurgitation must extend beyond a single technique (such as edge-to-edge repair), highlighting the feasibility of applying classic resection and suturing techniques alongside these devices. 

However, it appears that the Mi-STITCH® system may be specifically tailored for P2 prolapse repairs, potentially limiting its versatility for commissural prolapses, multiple posterior leaflet prolapses, or anterior leaflet involvement. Neochord implantation should adhere to the principle of placement in the tributary papillary muscle region (fan-like, without crossing the midline) to avoid interference with the subvalvular apparatus. While this system meets the classic neochord implantation principles, technologies like NeoChord® or Edwards HARPOON®—although off-pump systems—do not. Additionally, the system requires loop configuration measurements, necessitating adaptation by surgeons accustomed to using figure-of-eight or single-step techniques for papillary muscle passage. In this regard, the Mi-KNOT® device presents a promising option by allowing implantation at the precise point determined to be the correct chord length. Indeed, it could potentially be used independently of the other systems. The authors validate chord length determination with the saline test. A critique of the device is its irreversible knotting mechanism, unlike alternatives such as figure-of-eight or Dubai stitch configurations, which are popular for their flexibility. It also violates two classic principles of neochord implantation: 

• Neochords were traditionally anchored using another PTFE suture in loop techniques, as materials like polypropylene may eventually sever them. The titanium clip may compromise long-term repair durability. 

• The proximity of the metal clip to the coaptation surface, despite its small size, could lead to leaflet erosion and repair failure. 

The COR-KNOT® system is an effective option for anchoring annuloplasty sutures, particularly for annuloplasty but also increasingly used in prosthetic implantation techniques. 

LSI Solutions® is likely to continue innovating to develop these systems, which appear well-received within the surgical community. With this study and these reflections, I aim not to endorse indiscriminate spending on new tools at the expense of clinical judgment, but rather to encourage responsible innovation. As surgeons, we must demonstrate exemplary stewardship of costly resources for patient treatment. From an efficiency perspective, avoiding waste is as crucial as preventing nocebo effects, yet I am certain that the latter will consign us to clinical irrelevance without the support of the biomedical industry. 

REFERENCE: 

Werner P, Poschner T, Gross C, Russo M, Laufer G, Sauer J, et al. Evaluation of a Novel Automated Suturing Technology for Mitral Chordal Implantation: 1-Year Results. Ann Thorac Surg. 2024 Feb;117(2):474-478. doi: 10.1016/j.athoracsur.2023.10.014.