Minimally Invasive Direct Coronary Artery Bypass (MIDCAB) is a targeted form of cardiothoracic surgery (surgical treatment of organs inside the chest) designed to treat coronary artery disease (plaque buildup inside heart blood vessels). The primary mechanical objective of MIDCAB is to bypass a critical narrowing in the main front blood vessel of the heart, known as the left anterior descending artery. Surgeons accomplish this by rerouting an existing chest wall vessel, the left internal mammary artery (LIMA), directly to the heart muscle. By utilizing a small left-side thoracotomy (incision between the ribs) rather than opening the whole chest, the intervention achieves total surgical revascularization while preserving skeletal stability and eliminating the need for a heart-lung machine.

Under general anesthesia, a double-lumen endotracheal tube is placed to allow temporary collapse of the left lung. A 5-to-7-centimeter incision is made in the left fourth intercostal space between the ribs. The surgeon harvests the left internal mammary artery under direct visualization or micro-video assistance. A specialized mechanical suction stabilizer is applied to the heart wall to immobilize the left anterior descending artery while the heart continues beating normally. The surgeon performs a delicate micro-vascular anastomosis, sewing the internal mammary artery to the coronary vessel beyond the blockage using ultra-fine non-absorbable sutures. Intraoperative doppler flow probes confirm strong blood flow before a temporary chest tube is inserted and the chest wall layers are closed with dissolving sutures.

Clinical evidence demonstrates that MIDCAB provides key advantages over traditional open-chest bypass surgery, including lower risks of post-operative wound infection, reduced need for blood transfusions, shorter initial hospital stays, and quicker physical recovery. Because the procedure preserves the integrity of the breastbone, patients experience less structural chest pain and can resume normal activity, including driving and light exercise, weeks sooner than those undergoing full median sternotomy. Long-term vessel openness using the left internal mammary artery remains equal to traditional open surgery according to international surgical registries.

Hospital stay following MIDCAB averages 3 to 5 days, with initial surgical chest site healing occurring within 14 to 21 days. In contrast to traditional open-heart surgery, which requires 8 to 12 weeks for breastbone bone healing, MIDCAB allows patients to resume non-strenuous desk work and light driving by week 3 or 4. Complete physical recovery, including full exercise and participation in cardiac rehabilitation, is typically achieved within 6 to 8 weeks post-procedure.

MIDCAB treats severe focal atherosclerosis (hardening and narrowing of the arteries) located in the left anterior descending coronary artery. It is indicated for isolated single-vessel disease, proximal vessel blockages not ideal for catheter-based stents, and selected multi-vessel conditions managed through planned hybrid coronary revascularization (combining keyhole bypass surgery with stent placement). MIDCAB also serves patients with severe lung disease, advanced age, or prior chest operations who face high risks from traditional full-chest opening techniques.

Preoperative preparation includes comprehensive coronary angiography, chest computed tomography (CT) scanning to map arterial access, resting echocardiography, and pulmonary function testing. Patients undergo medication adjustments, including stopping specific antiplatelet drugs (such as clopidogrel or ticagrelor) 5 days prior to surgery based on surgical team instructions, while aspirin is often continued. Fasting begins at midnight prior to the operation, and targeted skin cleansing with chlorhexidine soap is completed the night before and morning of the procedure to minimize infection risks.

Complications after MIDCAB may include localized incision site pain, rib cartilage inflammation, minor wound bleeding, localized hematoma, or temporary atrial fibrillation (irregular heart rhythm). Less common but serious risks include perioperative myocardial infarction (heart attack), graft thrombosis (sudden bypass block), pneumothorax (air surrounding the lung), stroke, phrenic nerve trauma causing diaphragm weakness, deep wound infection, or urgent conversion to full open sternotomy due to unexpected surgical complexity or vessel anatomical challenge.

The clinical journey for MIDCAB begins with an outpatient evaluation, including detailed coronary angiography (heart vessel X-ray imaging) and respiratory function tests. On the day of surgery, general anesthesia is administered, and the patient undergoes a 2- to 3-hour operation in an operating room. Following surgery, the patient recovers in an intensive care unit for approximately 24 hours before moving to a standard post-surgical ward. Hospital discharge typically occurs within 3 to 5 days. Patients resume light daily walking immediately and complete a structured 6- to 8-week cardiac rehabilitation program to achieve full recovery.