How does it work?

Endoscopic aortic valve replacement

Mr Toufan Bahrami, senior cardiac consultant surgeon at Royal Brompton & Harefield Hospitals, on a pioneering endoscopic cardiac procedure that delivers significant benefits for the patients

Interview: Viel Richardson The aortic valve is a structure in the heart that sits between the ventricle and the aorta. In a healthy heart, oxygen-rich blood is pumped from the ventricle chambers through the aortic valve into the aorta, which then distributes the blood into general circulation. The aortic valve has three flaps called ‘leaflets’ which open each time the heart pumps to let blood flow into the aorta. They then close, sealing the valve to prevent any flow back into the ventricle.

There are two main disease conditions that might lead to someone needing a valve replacement. One is aortic valve stenosis, where the valve becomes narrowed and the leaflets cannot open fully. Instead of an opening of around 1.5-2.5cm, it might be around 0.6-0.9cm, meaning the heart has to work much harder. With stenosis, the leaflets can also become calcified, losing their flexibility. They are usually so thin and flexible they appear transparent, but once calcified they’re like wood, with very restricted movement, meaning they don’t make an effective seal to stop blood flowing back into the ventricle.

The second disease is aortic valve regurgitation or leakage. With this, the leaflets have normal flexibility but the ring holding the leaflets is dilated, so they don’t close properly. A leaflet can also become too flexible, so the seal is again compromised and blood can get back into the ventricle

The traditional and still most common approach to aortic valve replacement is a sternotomy. This involves making a 20-25cm incision down from the top of the sternum. We then use retractors to spread the ribs apart. This allows us to gain access to the heart and place the cannula tubes that go to the heart-lung bypass machines needed during the procedure.

A sternotomy is a major operation. We are creating a large opening of the chest cavity and a significant displacement of the ribs, and this leads to problems even after a very successful procedure. Patients can suffer from serious back and neck pain or pain in the ribs. They often have some difficulty breathing. This all means a long stay in hospital and a slow recovery. It can take the patient several months to get back to a fully active life.

There is also the option of a ministernotomy, which is the same as the standard treatment, but done through a smaller opening. The recovery time is a little better, but you still have most of the issues of the full sternotomy. There have been other attempts to limit these issues, but I decided to try a completely different approach.

Ventricle chambers The heart has four chambers. The top two chamber are the right atrium and left atrium. The bottom two chambers are the right ventricle and left ventricle. Each of these chambers has a valve that keeps blood flowing in one direction. Leaflets Flaps of tissue that make up the aortic valve. They act as one-way inlets for blood coming into a ventricle and one-way outlets for blood leaving a ventricle. Minimally invasive A form of surgery performed through one or more small incisions, using small tubes, tiny cameras and surgical instruments. Catheter A flexible tube that is inserted into the body, allowing liquid to flow to or from an organ.

To heart bypass machine

Sternal retractor used to separate ribs 3cm camera access 3cm opening for procedure

Specialised endoscope with surgical tools

To heart bypass machine

I have been a minimally invasive endoscopic surgeon for 22 years and at every stage of cardiac surgery I have tried to be less invasive in my work, as I have seen the benefits this brings to patients. I started developing a technique through which I could replace the aortic valve with a fully endoscopic procedure, therefore avoiding opening the ribcage and the trauma this causes. For the past two years, I have been doing the procedure totally endoscopically. All that’s need is a soft tissue opening about 3cm wide for the procedure and another opening on the side of the chest for us to insert the camera. The whole operation is done on the screen, similar to robotic surgery. This is the only centre in the UK where this procedure is carried out.

First, we carry out a very detailed investigation using equipment such as high-resolution CT scanners to create 3D reconstructions of the area. The idea is to spot any potential complications and create a clear plan before starting the procedure. For the operation itself, we make those two small incisions – the opening for the new valve and the surgical instruments to go through and the incision for the camera. We use the groin vessels in order to bypass the heart function, so there is no need for catheters in the chest area.

Once inside, we cut away the damaged or calcified tissue to create room for the new valve. After the area has been prepared, we insert the replacement valve, which can be made from either tissue or metal, and suture it in place. The whole operation takes about two to three hours.

It is a very different operation from a sternotomy. It requires new skills. You operate with much longer instruments – 30cm instead of 10-15cm. The surgeon works while looking up at the screens, not down at the heart. That takes training and experience. But the view the screens give you is so much better than looking at the heart directly, as you can manipulate both the camera and the image to get precisely the angle you need.

This a personal opinion, but I think the result is much better. The clarity of view you get on the screen is so superior that I believe it improves the quality of your work, as long as you have been properly trained in endoscopic surgery. Also, we are achieving the introduction of a new valve through a 3cm opening and not a 30cm one, which is better. With the full sternotomy, patients are often not woken until the following day and then spend two to three days in intensive care, then time in a recovery ward before going home. My patients often go home about four days after the procedure.

I’m passionate about this procedure because I have seen what it does for my patients, especially during their recovery. I have performed both types of procedure and at three weeks, for example, there is an incredible difference between the two. I have mentioned the problems such as back pain that sternotomy patients can suffer from for months afterwards – many struggle to walk for more than 10 to 15 minutes a day as they build their fitness back up. With endoscopic surgery, it is a completely different story. At three weeks some are back to work, they start driving again, they are fully active and getting their fitness back. One patient in his sixties send me a picture of himself hiking in the Pyrenees. It was remarkable.

Royal Brompton & Harefield Hospitals Specialist Care 77 Wimpole Street, London W1G 9RU 020 3553 9648 rbhh-specialistcare.co.uk