Chapter 32: Minimally Invasive Aortic Valve Surgery

INTRODUCTION

Aortic valve surgery started with the implantation of the Hufnagel valve in the descending thoracic aorta in 1956. Its evolution over time has culminated with the establishment of percutaneous catheter-based aortic valve replacement techniques. As a new paradigm in aortic valve replacement is ushered, there will be new challenges for the cardiac surgeons to not only maintain the efficacy and outcomes of conventional valve replacement but to provide it in a less invasive approach. Modern techniques will be measured against conventional procedures, especially in the older patients with multiple comorbidities. Minimally invasive aortic valve surgery holds promise as an effective operation with reduced pain, improved respiratory function, early recovery, and an overall reduction in trauma.

ESSENTIALS OF MINIMAL ACCESS AORTIC VALVE SURGERY

Reoperative minimal access aortic valve surgery is discussed in detail at the end of this chapter. We will first outline the known benefits and salient principles of and the essential ingredients for the conduct of primary minimal access aortic valve surgery. There are many potential benefits of minimal access aortic valve surgery:

1. It provides a cosmetically superior incision

2. There is reduced postoperative pain

3. There is faster postoperative recovery

4. There is improved postoperative respiratory function from preservation of a part of the sternum and the integrity of the costal margin

5. It can be performed with the same degree of ease and speed as a conventional operation with no difference in mortality

6. It provides access to the relevant parts of the heart and reduces dissection of other areas

7. It greatly facilitates a reoperation at a later date as the lower part of the pericardium remains closed.

There are some salient inviolate principles of minimal access aortic valve surgery:

1. Ability to safely apply a stable aortic cross-clamp

2. Ability to visualize the aortic valve completely and perform a successful replacement with the standard techniques

3. Ability to achieve the same degree of myocardial protection as through a midline sternotomy approach

4. Ability to deal with issues of the aortic root, ascending and arch of the aorta with relative ease and without the need for conversion

5. Ability to quickly convert to a standard midline sternotomy if compromising situations arise

The safety and reproducibility of minimal access aortic valve surgery depend on:

1. Availability of experienced cardiac anesthesiologists

2. Availability of transesophageal echocardiography (TEE) in every case and an experienced echocardiographer to interpret findings

3. Ability to place pulmonary artery catheters with pacing capabilities and transjugular coronary sinus catheters, if and when necessary

4. Ability to place percutaneous arterial and venous cardiopulmonary bypass canulae

5. Ability to use vacuum-assisted venous drainage on cardiopulmonary bypass

6. Availability of minimal access retractors and other relevant instruments that facilitate this operation

7. Ability to remotely monitor myocardial protection and distention by TEE

8. Availability of surgeons experienced with conventional aortic valve surgery and minimal access surgery.

APPROACHES

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