Aortic Valve Replacement Through Right Minithoracotomy Approach Using Central Cannulation and Sutureless Bioprosthesis

Introduction
The least invasive approach to surgical aortic valve replacement is through a right anterior minithoracotomy incision. Most groups using this approach cannulate either the femoral artery and vein or the ascending aorta and femoral vein to establish cardiopulmonary bypass. The authors, however, routinely cannulate the ascending aorta and superior vena cava, avoiding any incisions in the groin.

Technique
A 5 cm skin incision was made over the medial part of the second right intercostal space. Subcutaneous tissues were divided, the pectoral muscle was split along its muscular fibers, and the intercostal muscles were cut using cautery. Both the right internal thoracic artery and vein are doubly clipped and divided. Sometimes the access to the pericardium can be gained without opening the right pleural space by bluntly separating the parietal pleura from the chest wall. The mediastinal fat was removed and the pericardium was incised. The pericardial incision was placed toward the left side of the operative field so that the pericardium on the right side could be pulled to the skin level using three pericardial stay sutures on the right side and two on the left side. Adventitia between the ascending aorta and pulmonary artery was incised, and blunt dissection with the tip of the suction was performed to prepare the aorta for clamping. The superior vena cava was dissected cranially, in order to increase its length for central venous cannulation. Heparin was given and cannulation started. The ascending aorta was cannulated as cranially as possible by using a dry lap and index finger of the left hand to pull the ascending aorta caudally. Two 4-0 Prolene® (Ethicon, Sommerville, New Jersey, USA) purse-string sutures were placed, and then a small incision was made with an 11 blade followed by insertion of an EOPA® arterial cannula (Medtronic, Inc, Minneapolis, MN, USA). Central venous cannulation was performed. The authors’ preference is to cannulate the superior vena cava using either two 22 Fr Medtronic venous cannulas (L-type directed cranially, and straight-type directed caudally) (1) or by using a single 29 Fr Optiflow cannula (LivaNova PLC, London, UK). Cardiopulmonary bypass was established with negative pressure on the venous side. If the right heart and the pulmonary artery do not collapse, the venous cannulas may need to be repositioned. Antegrade cardioplegia cannula was then placed on the lateral part of the ascending aorta, and a purse-string suture was placed on the right superior pulmonary vein for later placement of the vent. The heart was then fibrillated, aortic cross-clamp was applied, and a single dose of antegrade del Nido cardioplegia (2) was given. While the cardioplegia was running, a vent was placed through the right superior pulmonary vein. In patients with severe aortic regurgitation, the ascending aorta is opened after applying the cross-clamp, and then the cardioplegia is delivered directly into the coronary ostia.

After finishing the cardioplegia, the ascending aorta was incised transversely approximately 2 cm above the sinotubular junction and the incision was extended as a lazy S-shape towards the non-coronary sinus. Commissural traction sutures (2-0 polyester) were placed to bring the aortic valve closer to the surgeon. The stenotic valve was then excised, taking care not to open the annulus, and the calcium was thoroughly debrided. In cases where defects in annular tissue are observed, these are closed with 4-0 or 5-0 Prolene® sutures. The annulus was then sized with Perceval sizers and the appropriate sized valve was implanted. The authors used balloon inflation at 2 atmospheres for 30 seconds to further expand the valve stent. The aortotomy was closed in two layers, which can be done with 4-0 or 5-0 Prolene® suture. An epicardial pacing wire was then placed, the heart was deaired, and the closs-clamp was released. With the heart beating and all lines still in place, transesophageal echocardiography was performed. As no paravalvular leakage was found, the vent and antegrade cardioplegia line were removed, and the patient was weaned off bypass and decannulated. After Protamin was administered and satisfactory hemostasis was achieved, a single 24 Fr chest tube was inserted. The right pleural space was opened during the procedure, and so the tube is inserted in the right pleural space. If this had not been the case, the authors would place the tube in the retrosternal space. The pericardial incision is usually not closed. The third rib was fixed to the sternum and second rib using two size 1 resorbable figure-of-eight sutures. The wound was then closed in layers and an analgesia catheter was placed in the wound.

Conclusion
This technique has been used successfully in over 250 cases of minimally invasive aortic valve replacements in the authors’ center. None of the patients experienced damage to the sinoatrial node or needed conversion to a different type of venous drainage. The technique is performed using standard surgical instrumentation.

References

1. Klokocovnik T, Jelenc M. Double superior vena cava cannulation for venous drainage in minimally invasive aortic valve surgery. June 2017. https://doi.org/10.25373/ctsnet.5104900
2. Matte GS, del Nido PJ. History and use of del Nido cardioplegia solution at Boston Children’s Hospital. J Extra Corpor Technol. 2012;44(3):98-103.