**2. Aortic valve replacement and radiofrequency isolation of the posterior wall of the left atrium in a high surgical risk patient: How we do it**

Patients with aortic stenosis and atrial fibrillation who are considered to be at high surgical risk typically exhibit a range of clinical features and comorbidities. Here are some of the key factors that are often considered when determining surgical risk:


Cardiopulmonary bypass (CPB) duration plays a significant role in the outcomes in this group. The length of CPB has been linked with several potential complications, including organ dysfunction, postoperative bleeding and increased mortality. A study by Ranucci et al. demonstrated that CPB duration is an independent predictor of overall mortality and major complications following cardiothoracic surgeries [40]. According to their analysis, every additional 10 minutes of CPB increases the risk of overall mortality by 16%, the risk of significant complications by 18%, and the risk of postoperative bleeding by 12%. An article by Gansera and colleagues (2007) emphasized that CPB duration is associated with the risk of postoperative renal dysfunction and thrombocytopenia [41]. This finding reinforces the importance of minimizing CPB time in aortic valve replacement surgeries. In another study by Raja and co-authors (2005), CPB duration was an independent risk factor for developing postoperative acute lung injury [42].

In order to reduce the duration of cardiopulmonary bypass in such patients, we employ the Perceval-S sutureless valve, Box-Lesion radiofrequency ablation protocol with an additional line in the Ridge zone, and Marshall ligament destruction. The Perceval-S valve is an artificial valve made from bovine pericardium, implanted within a self-expanding nitinol frame that secures the valve in the implantation site. The valve is stored in an antibacterial solution, eliminating the need for pre-rinsing. The valve implantation involves three guiding sutures, which are subsequently removed. These factors combined allow us to achieve a myocardial ischaemic time of 15–18 minutes.

*Surgical Treatment of Patients with Aortic Valve Disease in Association with Atrial Fibrillation DOI: http://dx.doi.org/10.5772/intechopen.112888*

Along with ablation and left atrial appendage occlusion, the total duration of cardiopulmonary bypass in our clinic for such procedures averages around 40 minutes.


It should be noted that the main contraindications for using the valve are aortic root dilation and disruption of the fibrous annulus integrity. Many surgical teams have successfully used Perceval-S in cases of bicuspid aortic valve.

### **3. Operation**

The first step involves the Box-Lesion ablation procedure. For RFA, we used a Cardioblate Gemini-S ablative device. The procedure is performed under parallel cardiopulmonary bypass due to hemodynamic instability during pulmonary vein occlusion. The right atrium is cannulated with a two-stage cannula. The aorta is cannulated as high as possible from the sinotubular ridge. After initiation of cardiopulmonary bypass using a dissector and forceps, the connective tissue in the area of the transverse sinus is separated by a blunt manoeuvre between the superior right pulmonary vein and the superior vena cava, and the inferior vena cava is mobilized. For the convenience and safety of bipolar clamp-ablator placement, we utilize specialized guides that minimize the risk of damaging surrounding anatomical structures. The guides are inserted similarly to the "Galaxy" procedure (**Figure 1**) [43]. The first guide is passed through the transverse sinus and removed behind the left atrial appendage. The second guide is passed through the oblique sinus of the pericardium between the inferior vena cava and the right inferior pulmonary vein. Since the ablation clamp and guidewires have a flexible structure, there is no need to rotate the heart at this stage. Next, the Cardioblate Gemini-S electrode is attached to the guidewires, and the electrode branches are introduced into the oblique and transverse sinuses of the pericardium on the left side to perform ablation of the left pulmonary veins and the posterior wall of the left atrium (**Figure 2**). The ablation of the right pulmonary vein orifices and the posterior wall of the left atrium is performed similarly (**Figure 3**). To create complete lines, we perform about 10 applications lasting about 10 minutes on each side. After completion of the ablation of the left atrium posterior wall, it is mandatory to perform an Exit-block test. Gemini-S electrodes allow ablation of the entire posterior wall of the left atrium as a single block according to the "box-lesion" scheme in the minimum amount of time (**Figure 4**). Additionally, the infusion of physiological solution into the clamp branches enables conducting ablation without charring the myocardium.

The second step involves a prosthetic implantation. Carbon dioxide gas insufflation is carried out into the surgical wound to prevent air embolism. Valve implantation is typically performed in a single session of blood cardioplegia. During the implantation of a sutureless valve, the aortotomy should be performed approximately

#### **Figure 1.**

*Flexible guides in pericardial cavity. (A) Ascendence part of the aorta, (B) right atrium canula, (C) flexible guides, (D) superior right pulmonary vein, and (E) inferior right pulmonary vein.*

**Figure 2.** *Performing left-side ablation.*

3–3.5 cm above the coronary artery ostia to ensure a safe aortotomy closure at the end of the procedure without interfering with the upper edge of the valve frame. After decalcification, we leave a rim of approximately 3 mm and provide valve sizing. We do not open the specific size of the prosthesis until we evaluate the patient's valve and measure its fibrous annulus. It is worth noting that a fibrous annulus larger than 27 mm is a contraindication for valve implantation.

After valve sizing, the prosthesis is prepared on a separate surgical table. The valve must be loaded into the delivery system to accomplish this. A valve holder and a collapser are set up on the stand (**Figure 5**). The collapser compresses the valve on the holder. In this state, the valve is presented to the operating surgeon (**Figure 6**).

*Surgical Treatment of Patients with Aortic Valve Disease in Association with Atrial Fibrillation DOI: http://dx.doi.org/10.5772/intechopen.112888*

**Figure 3.** *Performing right-side ablation.*

**Figure 4.** *Final ablation scheme. Trasmural injury marked with a blue line.*

Following decalcification of the valve and preparation of the prosthesis for implantation, we proceed with suture occlusion of the left atrial appendage. At this point in the operation, creating an additional ablation line connecting the Ridge zone and the left pulmonary vein collector is possible. In patients with persistent atrial

**Figure 5.** *Perceval-S fixed in collapser.*

fibrillation, we disrupt the adipose tissue in the Waterston's groove area and perform ablation of this zone with a Cardioblate MAPS monopolar electrode. Then we proceed with aortic valve implantation. Guiding sutures are sewn in the nadir of the leaflets. Incorrect distribution of guiding sutures can lead to the formation of paravalvular fistulas.

The sutures are passed through the valve ears (**Figure 7**). The valve is positioned at the fibrous annulus. The lower portion of the valve is opened first, followed by the upper portion. This sequence of unfolding allows us to verify the correct positioning of the lower part while it is still visually accessible. After unfolding the upper part,

*Surgical Treatment of Patients with Aortic Valve Disease in Association with Atrial Fibrillation DOI: http://dx.doi.org/10.5772/intechopen.112888*

**Figure 7.** *Fixation of the guide sutures.*

any changes in the prosthesis position can only be made through explanation of the prosthesis. After removing the holder, the position of the prosthesis relative to the fibrous ring and coronary artery ostia is visually evaluated (**Figure 8**). The final step of the implantation is balloon dilation, inserted into the valve lumen to a pressure of 4 ATM for 40–60 seconds. During this process, warm physiological saline is used to irrigate the valve frame for complete expansion of the nitinol frame. The main stage of the operation concludes with the formation of a double-row suture on the aortotomy. At this stage, it is critically important to visualize each suture to avoid capturing the prosthesis frame in the suture.

**Figure 8.** *Perceval-S implanted in aortic root.*
