Total endoscopic valve surgery with the Ram device in combined mitral and tricuspid valve disease

The patient is a 47-year-old female presenting with progressive dyspnoea on exertion (New York Heart Association functional class III) based on rheumatic mitral valve disease. She has a medical history of long-standing atrial fibrillation, hypertension and obesity (body mass index of 35 kg/m2). Preoperative echocardiography revealed a severely calcified posterior leaflet with severe mitral stenosis [mitral valve area 1.2 cm2; mean pressure gradient (MPG) 11.5 mmHg, maximum upstroke velocity (Vmax) 2.6 m/s), a severely dilated left atrial area (LAA 40.9 cm2)] and a preserved ejection fraction. Tricuspid valve regurgitation was classified as moderate to severe, and systolic pulmonary pressure was measured at 38 mmHg. An intraoperative transoesophageal echocardiogram revealed severe tricuspid regurgitation, which prompted the combined tricuspid valve repair. Coronary angiography revealed no significant coronary artery disease. We assessed the patient’s eligibility for ACC and peripheral groin cannulation via a preoperative CT scan.

• RAM device 5.0 mm
• RAM Quick Load 5.0 mm
• SEW-EASY device 5.0 mm
• SEW-EASY cassettes 5.0 mm
• Cor-Knot device (LSI Solutions, Victor, NY, USA)
• Cor-Knot Quick Load (LSI Solutions)
• multiSTATION System
• RAM ring

Before starting the suturing, the RAM device must be loaded by attaching a RAM Quick Load unit to its tip, securing the suture in the designated slots and gently pulling on the suture ends, allowing the needle caps to retract into position at the jaw of the device.

By squeezing the handle, the curved needles of the RAM device pass through the tissue, picking up and pulling the suture ends through the annulus, placing a horizontal mattress stitch.

A SEW-EASY cassette is then positioned at the tip of the RAM device to transfer the suture ends to the cassette. By pulling back the handle and retracting the sutures into position, the cassette can be removed and positioned at the RAM ring.

After loading the SEW-EASY cassette into the SEW-EASY device, the device is then used to pass the sutures through the sewing cuff of a prosthetic heart valve.

Anaesthesia

The patient was intubated after the initiation of anaesthesia using a double lumen tube. A transoesophageal echocardiogram probe was placed for continuous echocardiographic monitoring. Arterial monitoring was performed via the radial artery.

Access site

Operative access was established through right anterior minithoracotomy over the fourth intercostal space (ICS). After dissecting muscular tissue, the right lung was deflated, and the pleural space was opened. We then inserted a soft tissue retractor and made an incision for the camera using the same ICS. To reduce the risk of air embolism, we established carbon dioxide infusion through the camera port. Another skin incision was made to insert the Chitwood aortic clamp through the second ICS.

Peripheral cannulation

Cardiopulmonary bypass was established through percutaneous cannulation of the right femoral vessels and the right jugular vein using the Seldinger technique. After the femoral puncture was performed, a full heparin dosage was administered. For later haemostasis, three (Abbott Vascular, Santa Clara, CA, USA) vascular sutures were applied (2 arterial, 1 venous). Then, a 19 Fr long arterial cannula was inserted into the descending aorta through the common femoral artery. A 6 Fr distal cannula was placed to ensure antegrade distal limb perfusion. For venous cannulation, we placed a 27 Fr venous cannula in the femoral vein, and an additional 18 Fr venous cannula was inserted into the right internal jugular vein to facilitate adequate venous drainage.

After initiation of the CPB, the pericardium was opened superior to the phrenic nerve horizontally up to the innominate vein. The pericardiotomy was then expanded towards the inferior vena cava, and pericardial stay sutures were placed to better expose the heart by retracting the pericardial edges and advancing the heart closer to the surgical window.

A long cardioplegia cannula was placed into the ascending aorta. The transthoracic aortic clamp (Chitwood clamp) was inserted through the second ICS. Under video guidance, the aorta was cross-clamped, and antegrade cardioplegia with Custodiol was initiated.

Once cardiac arrest was achieved, the left atrium was opened via the interatrial groove. A vent was then placed into the left ventricle and an atrial retractor (Geister, Tuttlingen, Germany) was inserted via the thoracotomy. A supporting arm was introduced parasternally (at the level of the fourth/fifth ICS) while sparing the right mammary artery. Careful traction on the supporting arm achieves adequate visualization of the valve. If visualization is insufficient, further tension on the pericardial stay sutures can be applied to improve visualization.

A closer examination of the mitral valve showed a severely degenerated posterior mitral valve leaflet. After the excision of the anterior leaflet, we performed a commissurotomy and cut the posterior mitral valve leaflet to enlarge the annulus size and ensure enough space for the mitral valve prosthesis. Sizing led to the decision for an On-X 25/33 mm prosthesis.

Starting at the 6 o’clock position at the P2 segment, the pledgeted mattress annular sutures were placed counterclockwise using the 5.0 mm RAM device. Each suture end was transferred to a SEW-EASY cassette and positioned at the RAM ring.

Once the annular sutures were completed, the SEW-EASY device was used to pass the sutures through the sewing cuff of the valve prothesis. To avoid entanglement of the sutures, the SEW-EASY cassettes were secured in a clamp according to the order of the stitches. The valve prosthesis was then parachuted onto the mitral annulus.

A Cor-Knot device, which automatically crimps a titanium fastener around the sutures and cuts off the ends, was used to secure the valve to the annulus. The sutures were fastened alternately on each side, distributing the tension on the prosthesis and ensuring an optimal position. After fixing the valve prosthesis, the atriotomy was closed using a 4-0 Prolene suture in a classic two-layer method.

The right atrium was opened for the tricuspid annuloplasty, and the anterior wall was retracted. We chose a 26-mm Contour 3D ring (Medtronic, Minneapolis, MN, USA). Directly after each annular stitch, the suture was passed through the sewing cuff of the annuloplasty ring. The ring was later parachuted onto the tricuspid annulus. After securely seating the ring, the sutures were tied with the Cor-Knot device, and the atriotomy was closed with 4-0 Prolene suture in standard fashion. The tricuspid valve repair was performed without snaring the caval veins.

After de-airing and closing the right atrium, ventricular pacing wires were placed. The left ventricle was de-aired through the cardioplegia cannula, and the aortic clamp was opened. Intrathoracic haemostasis was ensured. The patient was successfully weaned off the CPB machine. The venous cannula was removed, and protamine was administered before removing the arterial cannula. Haemostasis in the groin was achieved using the placed Perclosure ProStyle (Abbott Vascular). The procedure was completed after readapting the ribs and closing the wound in layers. The skin was closed using an intracutaneous suture.

The postoperative echocardiographic examination 6 months after discharge showed a satisfying result with no mitral (MPG 4.5 mmHg, Vmax 1.78 m/s) or tricuspid regurgitation. No late complications or adverse events have been reported.

The total time for valve replacement was 30 minutes, with 15 minutes for annular suturing (RAM device) and 7 minutes each for passing the sutures through the sewing cuff (SEW-EASY device) and suture fixation (Cor-Knot device), respectively. Sixteen sutures were placed for the mitral valve prosthesis, with two insufficiently positioned and therefore replaced, requiring less than a minute for each suture.

The cross-clamp time was 116 minutes, and the CPB time was 175 minutes.

The patient was transferred to the intensive care unit, where she could be extubated on the day of the operation. During the stay in the ICU, she required a transfusion of 1 unit of red blood cells. On the fourth postoperative day, she was transferred to the general ward, where two additional units of red blood cells were administered. We reinitiated the antiarrhythmic therapy with a β-blocker due to episodes of tachycardic atrial fibrillation. With pharmacologic cardioversion, atrial fibrillation was successfully converted into a sinus rhythm before discharge.

Final echocardiographic examination showed an excellent result for the mitral valve (Vmax 2 m/s, MPG 4 mmHg), and no residual tricuspid regurgitation was observed. A mild pericardial effusion with no haemodynamic relevance was detected.

The patient was discharged on POD 11 in good general condition.