**3. Patient selection**

*Cardiac Surgery Procedures*

**aortic valve surgery?**

36%, *p* = 0.042).

Potential advantages of MIAVR are:

life earlier compared to full sternotomy AVR [16].

anterior mini-thoracotomy approach in the USA.

Although results of many retrospective and prospective studies behold a bright future for this approach, the prevalence of minimally invasive aortic valve replacement (MIAVR) has not met potential expectations: 29% of AVRs are done minimally invasive in Germany [7] and 12% in the UK [8]. Kaneko et al. [9] reported that 12% patients had hemi sternotomy AVR and 3.6% patients were operated via an

A possibly long learning curve and complexity of the procedure may dissuade the widespread uptake of MIAVR. In an era of trans-catheter aortic valve implantation (TAVI) [10], sufficient motivation should be present for cardiac surgeons to adopt MIAVR in majority of patients, especially considering the recent promising results [11].

Minimally invasive cardiac surgery is a thought process that aims to minimize the extent of surgical invasiveness [12]. The American Heart Association (2008) defined it as "a small chest wall incision that does not include the conventional full sternotomy" [13]. The STS database defines minimally invasive cardiac surgery as "any procedure not performed with full sternotomy and cardiopulmonary bypass (CPB) support" [14]. The AHA definition is more realistic in the sense that an open heart surgery procedure is more likely to be conducted with cardiopulmonary bypass support. Based on the current STS definition, only TAVI can be included.

a.Cosmesis and wound complications: Improved cosmesis and esthetic scar is the unquestionable benefit of MIAVR. Although superficial wound infections have been reported [15], avoiding a full sternotomy leads to complete avoidance of deep sternal wound infection and risk of sternal non-union. Patients are discharged from ICU and hospital earlier and they return to an active work

b.Post-operative bleeding and blood transfusions: The need for blood transfusion was reported to be reduced in patients undergoing MIVAR compared to full sternotomy AVR (36 vs. 52.4%, <0.001) [17]. Burdett et al. [18] showed that MIAVR patients had significantly less post-operative blood loss (232 vs. 513 ml, *p* = 0.00021) and were less likely to require blood products (fresh frozen plasma and platelets) (24 vs.

c.Post-operative pain: Randomized control trials (RCTs) [19] and meta-analysis [20] have shown reduced pain scores with MIAVR. Limited spreading and retraction of the chest wall minimizes the disruption of the costo-chondral and costo vertebral joints. It leads to decreased use of narcotic analgesia in the post-operative period and early ambulation, leading to a more rapid return to an active work life.

d.Ventilation time: Stolinski et al. [21] reported ventilation time of 9.7 +/ 5.9 h after AVR and 7.2 +/ 3.2 h after ART-AVR (*p* < 0.001). Pulmonary function test results were lower in conventional AVR than RAMT-AVR (*p* = 0.001) for FEV1, vital capacity, total lung capacity. Phan et al. [17] also showed a reduc-

e.Cost-benefit analysis: Due to reduced ventilation time, blood transfusion requirements, shorter ICU and hospital stay, total hospital costs were lower in minimally

tion in ventilation time of more than 4 h with MIAVR.

AVR group (\$36,348 vs. \$38,239, *p* = 0.02) [22].

**2. Why cardiac surgeons should adopt minimally invasive** 

**54**

Optimum patient selection is essential for MIAVR. The factors to be taken into consideration include individual surgeon preference and skill sets, the patient's anatomical factors and comorbidities. The commitment and experience of the entire surgical team including anesthetists and perfusionists plays a critical role in the successful outcome.

#### **3.1 Indications**

Patients presenting with severe and/or symptomatic aortic valve stenosis or insufficiency requiring an isolated AVR are potential candidates for MIAVR.

### **3.2 Contraindications**

