Sutureless Aortic Valve Replacement in a High Risk Octagenerian

Recent advances in aortic bioprostheses involve deployment of suture less Aortic Valves. The sutureless Perceval aortic valve replacement (AVR) has been used in more than 20,000 cases worldwide and has excellent haemodynamics. Its other positive features include deployment in smaller aortic roots. In this case we describe an 82 year old lady presenting with significant symptoms attributable to a degenerating bioprosthesis. Previous surgery involved a bioprosthetic valve (21 Hancock bioprosthesis) and a Mitral Valve repair. Redo surgery and concomitant procedures are better served with a suture less AVR which can be deployed rapidly and presenting a larger effective orifice area. These characteristics also make minimal access surgery more feasible.

A chest Computerized Tomogram (CT) scan was carried out to exclude significant calcification in the ascending aorta.This showed calcification in the arch and descending aorta.The Sinotubular (ST) to annulus ratio was less than 1.3.
A decision to proceed with AVR was made with the patient and her family.Options of TAVI were considered as were conventional and sutureless AVR.The decision to proceed with a sutureless AVR was made after presenting the risks and benefits of the various options.
An intra-operative Trans Esophageal Echo (TEE) confirmed a diseased bioprosthesis with only mild Mitral regurgitation.The gradient across the valve was 120 mmHg.The ST junction to annulus ratio was measured as 1.14:1.
Surgery was commenced with exposure of the right femoral artery and the vein.The sternum was opened using an oscillating saw.The heart was partially freed.The aorta, the right atrium and the right superior pulmonary vein were completely freed.Cannulation of the ascending aorta and the right atrium allowed the commencement of Cardiopulmonary Bypass (CPB).A left ventricular vent was passed via the right superior pulmonary vein (RSPV).A cardioplegia cannula was placed into the ascending aorta.

Introduction
There are currently two suturesless Aortic bioprostheses available.These include the Intuity valve from Edwards (California, USA) and the Perceval valve (LivaNova, London, UK).The latter has 10 year clinical experience with more than 22,000 implants worldwide.Clinical data is highly promising.This is borne out by the first clinical data at 5 years [1].A consensus working group has further defined the indications and contra-indications for its use [2].
Particular advantages are the reproducibility of the haemodynamics, ease of implantation, reduced invasiveness of the procedure, shorter ICU and hospital stays.Lower blood transfusion and lower costs compared to Transcatheter aortic valve replacement (TAVI) is also present [3].After cross clamping and delivery of cardioplegia into the aortic root, a high transverse aortotomy was made.The degenerated Hancock prosthesis was explanted.Further debridement of the annulus was carried out.The mitral valve was observed to be close to the aortic annulus and care had to be taken to preserve its integrity.
The native aortic annulus admitted a large Perceval sizer (equivalent to a 23-25 valve).Using 3, 4/0 Polypropylene sutures placed at the nadir of each sinus, further sizing was carried out.The 3 sutures were deemed to be 120 degrees apart.A valve was collapsed on the side table.The 3 sutures were passed through 3 eyelet sutures on the collapsed valve (Figure 1).The valve was deployed, a balloon was used to re-expand it and an inspection of the valve position was carried out (Figure 2).The aortotomy was closed.After thorough de-airing the cross clamp was released.Spontaneous cardiac activity commenced, in heart block.The PPM was recommenced.After filling an effective ejection, the valve was inspected by TEE.This showed excellent valve function with no para-valvular leak and a mean gradient of 2 mmHg (Figure 3).
The post-operative period was uneventful; the patient was transferred to the ward on the 2 nd day and discharged home on the 5 th day.Post-operative echo showed equally good haemodynamics to the intra-operative TOE.

Discussion
Transcatheter Aortic valve Implantation (TAVI) has made AVR possible in the higher risk group of patients.Costs associated with this therapy are however a deterrent.Sutureless valves have also been introduced [4].The three valves introduced onto the market include the Enable (3F), Perceval (LivaNova) and Intuity (Edwards).The Enable has since been withdrawn.
Transcatheter Aortic Valve Implantation (TAVI) has added to the surgical therapies available for severe aortic stenosis.However, concerns about durability, haemodynamics, subclinical thrombosis and occult intra-cerebral bleeding should be taken into context.The price also presents limitations to applicability.
The Perceval valve offers as less invasive a procedure as possible, with the advantages of great haemodynamics and satisfactory durability.Its unique design of proven pericardial leaflets mounted on a Nitinol stent allow for a wide range of indications in patients with severe aortic stenosis or mixed aortic valve disease.
The Perceval valve remains a widely used valve with more than 22, 000 implants worldwide.It has attained FDA approval in January 2016.The Perceval valve is easy to implant reducing the complexity even in challenging and time consuming procedures.It is safe and is therefore a valuable option to reduce post-operative complications.Perceval valve allows reproducible results both in Minimal Invasive Cardiac Surgery [5] and conventional sternotomy.The main categories of patients that will benefit from sutureless AVR are:

Figure 1 :
Figure 1: Intraoperative picture-A low profile valve with a large effective orifice area.Stability comes from a snug fit in the aortic root.

Figure 3 :
Figure 3: TEE-Mid-esophageal short axis view-A short axis TEE reveals a prosthesis that is very similar to a native valve.

Figure 2 :
Figure 2: Intraoperative picture-The properly deployed valve mimics a native valve closely.The lack of a sewing cuff aids haemodynamics.
The indications for use are aortic stenosis or stenoinsufficiency.Contra-indications include aneurysmal dilatation of the aortic root and bicuspid aortic valve.Due to the design of the valve, the ratio of the Sinotubular (ST) junction to the aortic annulus must not exceed 1.3.