The different approaches to Minimally Invasive Surgery for Mitral Valve Repair

Contributions of Minimally Invasive approaches to Mitral Repair

Mitral valve surgery has been performed for over 100 years, since Elliot Cutler’s first operation in 1923¹. Progress in this field over the years has led to techniques with the most conservative approach possible, reducing side effects for patients². Long-lasting repair techniques have gradually been developed, under the leadership of Dr Carpentier in the 1980s, and minimally invasive approaches were devised. The latest in these developments, the first robotic repair of the mitral valve was carried out by Carpentier’s team in 19982. 

The management of patients with mitral regurgitation and insufficiency has improved considerably, with an increasingly wide range of treatments available to cardiac surgeons.  The goal is to adapt the surgical technique according to the risk profile of patients, in order to reduce the operative risks and recovery time and improve patient comfort (reduction in post-operative pain and scar size)³. 

Multiple techniques available to surgeons

The most frequently used minimally invasive technique is the right minithoracotomy². Percutaneous approaches have developed around several available systems⁴. For the time being, robotic repair is limited to centres of excellence⁵. 

Table 1: the different minimally invasive mitral valve repairs, specifications and images – Image A: right minithoracotomy (Brüls 2020 ⁷), Image B: Edge-to-edge percutaneous repair (Schmidt 2022 ⁶) – Image C:  Robotic repair (Cuartas 2017 ⁸). 

The role of Minimally Invasive Mitral Valve Repair worldwide

The minimally invasive approaches for mitral valve repair have hugely developed in the last twenty years because of their benefits in terms of surgical morbidity and mortality, even though their technical nature requires advanced training for surgeons². The figures for minimally invasive versus traditional approaches vary widely around the world, from around 25% of surgeries in the United States to 50% in Germany². In Europe, the percentage of minimally invasive mitral surgeries varies by country, but also the size and experience of the surgical centres³. In Asia, although the proportion of minimally invasive techniques is increasing compared to traditional techniques, there is also a large disparity between countries. ³ 

The robotic approach is also progressing, with more and more centres of excellence being opened in Europe (in 2020: 30 centres in 12 countries⁵) compared to the United States, where around 1,700 robotic procedures are carried out every year¹. 

Patient eligibility criteria for Minimally Invasive Mitral Repair

Isolated mitral valve repair can be carried out in virtually all cases using a minimally invasive approach, provided that the surgeon and their team are trained in this technique. Minimally invasive surgeries provide limited operative visibility and surgeon mobility², and generally longer clamping and extra-corporeal circulation times⁷. There are certain absolute and relative contraindications to minimally invasive approaches (as shown in Table ²). Each patient needs to be carefully assessed to determine the best repair method².

Table reproduced and translated from Table 2 from Cuartas et al, 2019. ²

Medical devices with key properties throughout the procedure

The different repair techniques and materials used can have a decisive impact on the results of mitral surgery⁹. The mini- and micro-incisions used in minimally invasive approaches to mitral valve repair require appropriate surgical and endoscopic equipment². Here are some of the medical devices involved in mitral valve repair:

Non-absorbable monofilament sutures: Sutures will be used at various stages of the surgery, and their technical nature is essential to guarantee lasting attachment and good resistance to tissue stress, while ensuring sufficient tissue flexibility^{1, 2}. The cardiovascular sutures in the Peters Surgical range are the result of a long-standing collaboration with Prof. Alain Carpentier (Georges Pompidou European Hospital).

Clamps and clips: Tools specific to minimally invasive approaches will be used to control blood flow during repair. They will have to be able to offer suitable shapes, materials, and sometimes adapters to provide a good anastomosis under direct vision or by endoscopy. 

Annuloplasty rings: Implemented to remodel and stabilise the mitral valve, several ring shapes have been tested and proposed over the years with varying results⁹. 

Endoscopic instruments: There are a range of instruments that are currently available to cardiothoracic surgeons specifically adapted to endoscopic procedures, including scissors, clamps, and specialised needle holders². 

Robotic systems: All the systems used for robotic methods, including robotic arms and control consoles, are state-of-the-art equipment used in centres of excellence in cardiac surgery^{1, 5}

Inset: Cardionyl^® is a non-absorbable nylon 6.6 monofilament suture. Cardionyl^® has been used in various types of minimally invasive or more traditional mitral surgery (see Table 3). Its good flexibility, combined with good resistance to tissue stress, makes it easy to handle and ensures reliable suturing.  

Surgical techniques are constantly evolving for the benefit of patients and the comfort of surgeons². The medical devices that come with these advances, from sutures to the most advanced robotic systems, play a crucial role in the success of operations. Reliability, handling, and continuous innovation are key to improving clinical outcomes and providing the best possible care for patients with mitral disease.

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