Due to the development of medical technology, during the last 30 years cardiac surgeons can choose between open surgeries and less invasive transcatheter interventions on the aortic valve. Each technique has its own advantages, therefore, the proper selection of patients with attention to aims of the operation and its possible risks is extremely important.
Open surgeries provide extensive surgical access, through which the cardiac surgeons can simultaneously perform interventions on several valves or other cardiac structures. However, these are serious and invasive interventions, which require thoracotomy and using the heart-lung machine for 3-6 hours.
Transcatheter interventions are more sparing, they maintain the integrity of the thorax, heart walls, and large vessels. The catheter delivers the valve prosthesis and miniature surgical instruments directly to the target area. This technology allows the surgeon to carry out the operation even in patients with high risk, preventing the development of irreversible changes in the left ventricle.
Aortic valve replacement techniques
The indications for aortic valve replacement include severe stenosis, birth defects (an isolated defect of the aortic valve or, more often, a combined heart defect), severe degenerative or rheumatic lesions of the valve.
Replacement of the affected valve with a biological or mechanical prosthesis. Biological prostheses are manufactured using tissue engineering technology, most often they are based on the bovine pericardium tissue. For example, this group includes various modifications of the aortic valves of the Carpentier-Edwards PERIMOUNT series.
Another option for the preparation of a biological prosthesis is an operation according to the Ozaki technique, when a new valve is made from the patient's own pericardium (pericardial sac). In this case, the structure of the biological valve is similar to patient's tissues, so it does not cause immunological rejection and can be used in young women who are planning to have children in the future.
Mechanical prostheses are predominantly made of pyrolytic carbon with the addition of tungsten (it makes the valve visible to the x-ray machine). The lifelong anticoagulant therapy is required after the implantation of a mechanical prosthesis. Moreover, such valves are considered to be more durable, their service life exceeds 20-30 years.
The transplantation of a vascular valve homograft is similar to the implantation of a biological prosthesis, except that the allogeneic vessels (namely, tissues which are taken from the body of a deceased donor) serve as material for the manufacture of homografts. The sampling, processing, and storage of vascular homografts are regulated by the international guidelines of the European Homograft Bank. In order to improve the mechanical characteristics, valve homografts can be placed in an additional frame made of synthetic polymeric materials.
Most often, this treatment method is used in young patients, as well as in presence of contraindications to prolonged use of anticoagulants. The research results have confirmed the excellent long-term efficacy and safety of using vascular homografts for aortic valve replacement.
Ross procedure. During Ross procedure, the healthy pulmonary valve is switched with the affected aortic valve. The pulmonary valve ideally substitutes the structure and function of the aortic one. The pulmonary valve is harvested from the patient at the first stage of surgical intervention. It ensures the complete immunological compatibility of prosthesis and absence of the rejection risk.
An epoxy-coated donor valve is implanted instead of the pulmonary valve. Effectiveness of the Ross procedure is explained by a lower load on the pulmonary valve in comparison with the aortic valve. On average, blood pressure in the aorta is always above 120 mm Hg, while the normal blood pressure in the pulmonary artery does not exceed 30 mm Hg, even during the physical load. In addition, in performing Ross procedure in the childhood, the replaced valve proportionately grows as the child becomes older.
Plastic techniques which preserve patient's own aortic valve
In some cases, cardiac surgeons prefer the reconstruction of patient's own aortic valve to its replacement. The indications for plastic surgery of the aortic valve include the isolated aortic insufficiency or stenosis with preservation of the left ventricle function, and small structural valve defects.
"Suturing" of the aortic valve. Normally, the aortic valve has three identical leaflets which take equal part in its work. In case of deformation or destruction of the leaflet or its part, two of them can be "sutured" together. It provides a more complete closure of the valve during the contraction of the left ventricle. At the same time, the valve function does not suffer, since the bicuspid aortic valve also develop in the norm, being an individual feature.
David procedure. Standard surgical tactics in aortic root aneurysms (exactly here the aortic valve is normally located) includes complete replacement of the affected area. During David procedure, the aortic valve is carefully removed from the affected aorta and subsequently transplanted into a new vascular prosthesis.
The operations in disruption of the anatomical integrity of the valve leaflets. In case of rupture or perforation of the aortic valve leaflets, the cardiac surgeon restores their integrity using synthetic materials or biological tissue based on the pericardium. During the intervention, a "patch" is installed on the damaged area, which is subsequently fully integrated into the tissue of the valve leaflet.
Surgical techniques for the interventions on the aortic valve
In modern surgical practice, the doctors use 2 basic techniques of interventions on the aortic valve. It is an open surgery and transcatheter procedure for plastic surgery or replacement of the affected valve.
An open surgery is performed under the general anesthesia, with the obligatory connection of a patient to the heart-lung machine. The cardiac surgeon makes a 25 cm cut on the sternum and opens the thorax. The open surgery provides an excellent surgical field. The heart with all its valves, adjacent large blood and lymphatic vessels are perfectly visible. The procedure takes from 3 to 6 hours.
In some cases, the invasiveness of the operation can be reduced by choosing a more sparing access, such as:
- Mini-thoracotomy – the 5-7 cm long incision is made along the right edge of the sternum, followed by muscle separation and dissection of blood vessels.
- Mini-sternotomy – the surgeon cuts only the upper part of the sternum, providing limited access to the aortic valve.
- Robot-assisted intervention – the miniature endoscopic instruments are inserted into the thoracic cavity through 2-4 small incisions; further actions of the surgeon are guided by a computer and displayed on the monitor in the operating room.
Transcatheter aortic valve implantation (TAVI or TAVR) is performed without a sternotomy and connection of a patient to the heart-lung machine. It is more sparing intervention which can be performed in high-risk patients – in old age, impaired liver and kidney function, and severe heart and lung diseases.
During the procedure, a catheter is inserted into the femoral artery. The aortic valve prosthesis is compactly folded at its end. Moving along the vascular system under the control of imaging techniques (echocardiography or radiography), the catheter reaches the aorta. Here, the prosthesis is disconnected from the catheter and opened, pressing the leaflets of damaged aortic valve to the walls of the aorta and replacing them. At the same time, unlike the open operation, the prosthesis is securely fixed in the vessel without removing the old valve. The entire procedure takes no more than 2 hours.
The efficacy and safety of the open and transcatheter aortic valve implantation was studied in several randomized multicenter clinical trials. In particular, these are PARTNER 2A and SURTAVI. According to their results, TAVI demonstrates similar or higher efficacy compared with traditional surgery. According to the current international recommendations of European and American communities, the range of indications for carrying out transcatheter procedures has significantly expanded. Since 2017, patients from moderate and low risk groups are also eligible for such treatment.
Choosing a hospital for proper treatment selection and performing
Today, drug and surgical treatment of aortic heart defects is carried out in cardiological hospitals around the world. It is important to choose an appropriate medical facility with the specialists who will provide an excellent therapeutic result, since repeated cardiac interventions are associated with high risks.
While studying information about specialized cardiological centers, you should not limit yourself to hospitals in your home country. In case of properly prepared documentation, leading hospitals in European countries with developed healthcare systems accept foreign patients for a treatment. If you are planning treatment abroad for the first time, it will be more convenient and reliable to use services of the company Booking Health.
Booking Health is the only certified provider of medical tourism (ISO 9001:2015 certification) which has been organizing treatment of cardiac patients from 75 countries in the world’s leading specialized hospitals for more than 10 years. Our specialists will provide you with constant support and will help you in such important moments:
- Choosing the right clinic based on the annual qualification profile
- Establishing communication directly with your doctor
- Preparing medical program in advance, without repeating previous examinations
- Providing favorable costs, without overpricing and additional coefficients for foreign patients (saving up to 50%)
- Booking the appointment on the necessary date, the possibility of urgent hospitalization
- Independent monitoring of a medical program at all stages
- Help in buying and forwarding of medicines
- Communication with the clinic after treatment completion
- Control of invoices and return of unspent funds
- Organization of additional examinations and cardiac rehabilitation
- Offering service of the highest level: booking hotels and plane tickets, transfer organization, interpreting services
Please, leave a request with medical and contact information on the official website of Booking Health, and a competent medical advisor or medical coordinator will contact you the same day.
Choose treatment abroad and you will for sure get the best results!
Author: Dr. Nadezhda Ivanisova