How to Perform a MIDCAB Procedure Step-by-Step in Single Vessel Disease

Introduction

Since the first reports of the off-pump technique and minimally invasive access (1, 2), coronary artery bypass grafting (CABG) performed through a small anterior lateral thoracotomy without cardiopulmonary bypass has become an increasingly popular technique worldwide. The minimally invasive direct coronary artery bypass (MIDCAB) has been used for patients with a single vessel disease when a coronary stent placement failed. In this step-by-step video, the authors show their technique for this procedure.

Case Presentation

A 73-year-old female patient with severe chest pain was brought to the emergency room. The electrocardiogram (ECG) did not show ST elevation, and the cardiac enzyme levels were normal. A catheterization was performed on the coronary arteries and a 100% stenosis of the left anterior descending artery (LAD) was observed. Due to the impossibility of stent placement, a surgical solution was decided. Through a left anterior small thoracotomy, a video-assisted single bypass from the left internal mammary artery (LIMA) to LAD was performed with a good postoperative outcome.

Operative Technique

1. A small anterior thoracotomy was performed in the left fifth intercostal space. Transesophageal echocardiography (TEE) and ECG were used to monitor ventricular function during the whole procedure.
2. A special rib retractor (ThoraGate™, Geister®, Germany) was selected to elevate the fifth rib for improved visualization for LIMA harvesting. It is not mandatory, but in some cases a video camera can be helpful for a better harvesting technique.
3. The artery was mobilized as high as possible, which is important to ensure an adequate length to reach the coronary artery without tension.
4. The pericardium was opened. A silk suture can be used for traction of the pericardium.
5. The anterior descending artery was identified.
6. A stabilization device was positioned to expose the descending artery.
7. A longitudinal incision was made in the coronary artery and bleeding was controlled with carbon dioxide.
8. A 1.2 mm shunt was inserted into the coronary artery.
9. The LIMA was prepared for bypass. Continuous stitches of 7.0 polypropylene (Prolene®, Ethicon) were used to construct an end-to-side anastomosis from the LIMA to LAD.
10. The shunt was removed and the anastomosis was finished.
11. The bulldog clamp was removed from the LIMA.
12. The TEE and ECG showed no complications during the entire procedure.

Discussion

A small thoracotomy instead of the classical sternotomy could reduce notorious thorax trauma. Shorter hospital stay, less postoperative pain, and faster recovery to activities have been described by some authors who compared CABG to MIDCAB and described the latter as a feasible technique (3-5). Nonetheless, a minimally invasive thoracotomy represents a very different approach when compared to sternotomy because the operative field is external, the anatomical relationships are different, and with a small approach, the structures are difficult to observe and control. Another disadvantage is that while dissecting the mammary artery, direct vision may sometimes not be enough, so a video camera can be very useful to reach 5 to 8 cm more of this artery. A short pedicle, associated with pulmonary excursion and intimate contact with the endothoracic fascia, may cause an early bypass occlusion (6). In addition, the potential benefits of MIDCAB, the low incidence of bleeding, early mobilization, and aesthetic results may be only weak factors for promoting the adoption of this technique. The authors argue that today's development is supported by factors that are not based on evidence, such as increased demand from patients and referring physicians (7).
Conclusions

The MIDCAB technique through a left anterior small thoracotomy is an excellent choice when a single coronary vessel is affected.

References

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2. Subramanian VA, Sani G, Benetti FJ, Calafiore AM. Minimally invasive coronary bypass surgery: a multicentre report of preliminary clinical experience. Circulation. 1995;92(Suppl 1):645.
3. Detter C, Reichenspurner H, Boehm DH, et al. Minimally invasive direct coronary artery bypass grafting (MIDCAB) and off-pump coronary artery bypass grafting (OPCAB): two techniques for beating heart surgery. Heart Surg Forum. 2002;5(2):157-162.
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