Difficulty in accessing the ascending aorta has been one of the major challenges in minimally invasive coronary artery bypass grafting (MICS CABG). Stepwise technique of proximal anastomosis in MICS CABG had been reported. However, opening the intercostal space (ICS) suited for distal anastomosis for off-pump MICS CABG often causes the incision to be too distant from the ascending aorta to complete the proximal anastomosis. We introduce assistive techniques of proximal anastomosis via the fifth ICS in off-pump MICS CABG.
Preoperatively, we examine the condition of the ascending aorta, location of the left ventricular apex, intercostal space to be opened, and length of the internal thoracic arteries with an enhanced 3-dimensional computed tomography. A patient is positioned in 30 to 40 degrees right decubitus position. An 8-cm skin incision and left thoracotomy is made in the fifth ICS below the left nipple. After harvesting the internal thoracic arteries and saphenous vein grafts (SVGs), ThoraTrak retractor (Medtronic Inc, Minneapolis, MN USA) is used to open the thoracotomy and is pulled toward cephalad and rightward directions using Kent retractor toward the ascending aorta (see Video, http://links.lww.com/INNOV/A131). The pericardium is fully opened from the distal edge of the ascending aorta to the left ventricular apex and the inferior vena cava (video 0:00:03) (Fig. 1). Both sides of the pericardium near the ascending aorta are retracted to the skin incision to lift up the ascending aorta as described in a previous report (video 0:00:08).1 Two retraction sutures on the lateral pericardial edge are held on the skin to displace the heart laterally. After retracting the pericardium, the Octopus tissue stabilizer (Medtronic Inc, Minneapolis, MN USA) is placed with its suction tip bent 60 degrees (Fig. 2) to pull the pulmonary artery down caudally to expose the ascending aorta (video 0:00:14). The space between the ascending aorta and pulmonary artery were dissected carefully, enhancing the exposure (video 0:00:18). The adventitia around the ascending aorta is removed to avoid slipping of a clamp. A side-biting clamp, Cygnet Flexible Clamps Lambert-Kay Jaw (Vitalitec Inc, Plymouth, MA USA) (Fig. 3), is then placed on the ascending aorta (video 0:00:25). After SVGs are prepared for proximal anastomoses, we examine the side-biting clamp to ensure no slipping has occurred. The SVGs are anastomosed onto the ascending aorta with mono-axis fine forceps and a needle holder for MICS. After stitching the SVGs (video 0:00:37), sutures are tied down with a knot pusher (video 0:01:00).
A total of 31 proximal anastomoses in 22 cases were completed with this technique in off-pump MICS CABG between November 2013 and June 2015. We planned to anastomose SVG onto the ascending aorta with this technique in all 22 cases. All 31 proximal anastomoses were completed using this technique without any difficulty. The average number of anastomosis was 3.3 ± 1.2. All anastomosis was handsewn without using a proximal anastomosis device. There was no conversion to sternotomy or aborting of the proximal anastomosis.
Excellent outcomes of MICS CABG have been reported.2,3 However, cardiopulmonary bypass is required in some cases of MICS CABG, partly owing to the difficulty of completing the distal anastomosis. We believe our techniques are noteworthy because they allowed successful completion of off-pump MICS CABG in all cases, as intended, with our heart displacement technique.4 Preoperative 3-dimensional computed tomography scans assist in determining which ICS to open because we usually open the ICS just above the left ventricular apex. In almost all case, we opened the fifth ICS for off-pump MICS CABG. In our experience, the fifth ICS approach for distal anastomosis is often the most suited to complete MICS CABG without the assistance of cardiopulmonary bypass. However, when adapting a previously reported approach of completing the proximal anastomosis via the fifth ICS,1 we experienced technical hurdles because of a long distance from the thoracotomy to the proximal anastomosis. Therefore, we have developed supplemental techniques to overcome this challenge. In this technique, we first open the pericardium completely. And two retraction sutures attached to the lateral pericardial edge are held on the skin. This maneuver displaces the heart toward the left thoracic cavity and the ascending aorta subsequently approaches the thoracotomy. Next, the pulmonary artery is retracted caudally by the Octopus tissue stabilizer, of which the tip is bent 60 degrees. This approach of pulling down the pulmonary artery, rather than pressing on it, maintains the shape of the right ventricle outflow tract, allowing to maintain stable systemic blood pressure. This maneuver also moves the ascending aorta toward the thoracotomy and exposes the aortic root by displacing the pulmonary artery. In our technique, the aortic root is dissected out near the right coronary ostium. We protect the right coronary artery with a malleable retractor when the ascending aorta is side-clamped.
Retracting the ThoraTrak retractor to the cephalad and rightward direction, along with the use of the pericardial sutures, also make the ascending aorta to move toward the thoracotomy.
In this report, we describe assistive techniques for proximal anastomosis to facilitate a successful off-pump multivessel MICS CABG. This approach can be used safely to facilitate proximal anastomoses without using proximal anastomosis devices, aiding the seamless conduct of off-pump MICS CABG.
1. Chan V, Lapierre H, Sohmer B, Mesana TG, Ruel M. Handsewn proximal anastomoses onto the ascending aorta through a small left thoracotomy during minimally invasive multivessel coronary artery bypass grafting: a stepwise approach to safety and reproducibility. Semin Thorac Cardiovasc Surg
2. McGinn JT Jr, Usman S, Lapierre H, Pothula VR, Mesana TG, Ruel M. Minimally invasive coronary artery bypass grafting: dual-center experience in 450 consecutive patients. Circulation
3. Barsoum EA, Azab B, Shah N, et al. Long-term mortality in minimally invasive compared with sternotomy coronary artery bypass surgery in the geriatric population (75 years and older patients). Eur J Cardiothorac Surg
4. Kikuchi K, Une D, Suzuki K, et al. Off-pump minimally invasive coronary artery bypass grafting with a heart positioner: direct retraction for a better exposure. Innovations