**3.8 Atrial fibrillation**

54 Front Lines of Thoracic Surgery

state, and most importantly micro-emboli from CPB. Studies of s100 protein, a marker of neurological damage, have shown lowers s100 protein after OPCAB compared to those after on-pump CABG; however, the incidence of clinical neurocongnitive manifestation was similar between OPCAB and on-pump CABG (Lloyd et al., 2000). The benefit of OPCAB in relation to neurocongnitive disorder remains controversial (Van Dijk et al., 2002, Browne et

Contact between the blood and the CPB circuit triggers an inflammatory cascade. Cytokines, complements and coagulation-fibrinolytic system are activated by CPB, which inducing CPB-related inflammatory responses (Ngaage, 2003). This inflammatory response contributes to the increase in capillary permeability, fluid shift, and decrease in tissue perfusion. Systemic inflammatory response syndrome may cause multi-organ failure, including lung, brain, kidney and heart, which may promote patient mortality. Significant decrease in inflammatory markers has been observed in OPCAB compared to that in onpump CABG (Ascione et al., 2000). Avoidance of CBP reduces the inflammatory state and contributes to early patient recovery (Raga, 2004). CPB-related inflammatory response could cause pulmonary edema resulting in hypoxia, brain edema resulting in neurocognitive disorder, renal hypoperfusion resulting in acute renal failure, and edema of the heart

Perioperative anaemia among the patient undergoing CABG is common. Hemodilution may occur from the circuit and tubing of the CPB. The use of CPB activate fibrinolytic activity and reduce the actual number of platelet and function of the platelet, which aggregates perioperative blood loss anaemia (Khuri et al., 1992). Studies have shown that OPCAB has clear benefits in blood preservation. Postoperative blood loss and transfusion requirements are smaller in OPCAB than in on-pump CABG in almost all studies (Muneretto et al., 2003). Avoiding the need for transfusion is critical in caring for Jehovah's

Hypoperfusion of the kidney during CABG may cause postoperative renal dysfunction. Risk factors for renal dysfunction are often observed in patients who undergo CABG, such as patients with diabetes, hypertension and peripheral vascular disease. Non-pulsatile flow and low perfusion pressure due to CPB contribute to hypoperfusion of the kidney, causing postoperative kidney injury (Laffey et al., 2002). The duration of CPB has been known to be directly related to the incidence of postoperative renal failure. The postoperative rise in creatinine after OPCAB is less frequently observed than that after on-pump CABG (Celik et al., 2005). A lower incidence of postoperative renal failure is observed after OPCAB (Calafiore et al., 2003). This renal protection with OPCAB would be most beneficial for patients showing moderate or severe preoperative renal dysfunction (Hirose et al., 2001).

A randomized trial showed that OPCAB provides lower pulmonary compliance, better gas exchange after surgery than on-pump CABG (Staton et al., 2005). Clinically, intubation time

after surgery as shorter after OPCAB than after on-pump CABG (Puskas et al., 2008).

al., 1999, Marasco et al., 2008).

**3.4 Inflammatory reaction** 

**3.5 Blood transfusion** 

Witness patients.

**3.6 Renal function** 

**3.7 Respiratory function** 

resulting in low cardiac output syndrome.

Atrial fibrillation is the most common arrhythmia after cardiac surgery and occurs in 25-40 % of patients. The incidence of atrial fibrillation after OPCAB is known to be less than that for on-pump CABG (Ascione et al., 2000, Raga et al., 2004). Avoiding atrial cannulation and preserving the anterior epiaortic fat pad may contribute to lowering the incidence of postoperative atrial fibrillation (Cummings et al., 2004).
