Minimal invasive mitral valve repair is a standard, well-established surgical technique.1,2 In patients with excessive valve tissue, as in myxomatous or Barlow disease, it can be cumbersome to visualize and access the subvalvular mitral valve apparatus. This is needed for papillary muscle shortening or the implantation of artificial chords. Several techniques, such as rings or stay sutures to fold away the mitral leaflets, have been described but hamper flexible use.
In this report, we describe an adaptive, easy and cheap, but effective method for pushing away the leaflets, thus allowing free view and perfect access to the subvalvular apparatus.
MATERIALS AND METHODS
Between April 2014 and December 2016, this technique was performed in 34 consecutive patients (mean ± SD age = 57.2 ± 11.5 years; 22 male) undergoing minimal invasive mitral valve repair through a 5- to 6-centimeter-long anterior thoracotomy. Sixteen of them underwent additional procedures, such as tricuspid valve repair (n = 8), atrial septal defect closure (n = 5), or MAZE procedure (n = 9). The underlying valve pathology was prolapse of the posterior and anterior leaflet in 21 and 6 patients respectively, Barlow disease with bileaflet prolapse in seven patients.
The calculated risk score for additive EuroScore, logistic EuroScore, and EuroScore II was 4 ± 2, 3.2 ± 2.1, and 2.5 ± 5.4, respectively.
Visualization of the mitral valve was accomplished with a 10-mm 30-degree endoscope 2D in the first 31 patients (Olympus Europa SE & Co. KG, Hamburg, Germany) and 3D in the last three patients (B.Braun Aesculap, Tuttlingen, Germany). After mitral valve analysis of the underlying pathology, a simple sterile paper ruler (ArcRoyal, Ireland) was curled to a roll 1 centimeter in diameter and inserted through the mitral valve (Fig. 1A). By means of two endo forceps, the paper roll was unrolled to the desired diameter, thus pushing the valve leaflets away, allowing for a direct view onto the subvalvular apparatus (Video, Supplemental Digital Content 1, http://links.lww.com/INNOV/A205).
Extracorporeal circulation time was 199 ± 47, and aortic cross-clamp time was 131 ± 23 minutes. No patient died within the first 30 days or in hospital. All patients presented mitral valve insufficiency grade 0 to 1 postoperatively.
This technique was successfully used in all patients. Implantation of artificial chords (Implant Chordae Loops; Santec, Grosswallstadt, Germany) was performed in every patient (3.6 ± 1.8 chordae per patient). In addition, a semi-rigid, full anuloplasty ring was implanted in all patients (mean ± SD size = 33.5 ± 1.9 mm, 30–36 mm). Shortening of the posterior papillary muscle and transfer of secondary chords was performed in two patients.
The artificial chords could be anchored at the desired spot of the papillary muscles without the need of any stay sutures (Fig. 1B).
The minimal invasive approach through a right-sided minithoracotomy for mitral valve surgery is a well-established procedure with low conversion rates and a high proportion of mitral valve repair. The implementation of 3D endoscopes further improved the visualization of the valve. However, excessive valve tissue especially in myxomatous and Barlow disease can be cumbersome during surgery, because the minimal invasive nonrib-spreading approach reduces the operating range and flexibility of surgical instruments significantly. When applying surgical techniques to the papillary muscles, valve tissue most likely hinders free sighting.
That was the reason why we developed a simple method to overcome these shortcomings.
This new utility accomplishes, the excessive mitral valve tissue to be pushed toward the annulus creating a tunnel of free vision. Thus, the surgeon can freely use his two endo instruments for operating on the subvalvular apparatus, such as papillary muscle shortening or placement of artificial chords. Tying knots is a simple task because the threads can no longer entangle with the leaflets or chords, when being slided down with the knot pusher.
A similar technique has been described,3 using a fixed ring built from a paper ruler. This works well for pushing away the mitral leaflets; however, our curled paper roll is somewhat more adaptive during surgery, because the exact diameter needed can be changed while using it. In contrast to a fixed ring, it can be curled to smaller diameters or unfurled while in place in the mitral valve. No preprocedural measurements are needed to estimate the correct size in advance.
Some other devices are commercially available such as Dr. Lamelas4 papillary muscle exposure device (Miami Instruments; Collar, Miami Lakes, FL USA). Recently, Tudorache and Haverich5 reported on a reusable leaflet retractor. This nickel-titanium mesh allows vision to the leaflets underneath the mesh but carry some risk of capturing structures within the metal grate. It can be rolled to a 15-mm cylinder, which might be a limitation when using it for complete endoscopic mitral valve repair.
The paper roll can be even curled to smaller diameters without compromising its function, and it can be pulled out and repositioned whenever needed, thus allowing a versatile workflow (Fig. 2). An additional advantage is the curled shape: when removing the paper roll, no sutures such as chordae anchored to the papillary muscle have to be passed through a fixed ring, because of the open curl. Furthermore, the curled shape distributes the radial force evenly to the mitral leaflets.
This inexpensive technique reduces trauma to the leaflets by stay sutures, is easy to position and withdraw, and allows multiple reuse whenever needed. It does not need any specific preparation before use and diminishes the risk of entanglement of any sutures. It might likewise be helpful for new as well as experienced centers to reduce movement and improve sight and workflow.
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: Wakka technique. Ann Thorac Surg
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