The introduction of endoscopic heart valve surgery into the UK
Authors: S. Hashim
Journal: Journal of the Royal Society of Medicine (2005)

The last 20 years have witnessed the large-scale introduction of minimally invasive techniques in surgery. These have allowed a more patient-focused approach than conventional methods, with smaller incisions and minimal tissue retraction resulting in less pain, better cosmetic results and reduced recovery time. The drive to increase day-case procedures in order to reduce bed occupancy and hospital costs, coupled with advances such as the development of intravenous anaesthesia, digital endoscopic cameras, stapling devices and purpose-built narrow shafted instruments, has led to the virtual disappearance of some conventional open procedures such as cholecystectomy in favour of laparoscopic approaches.1

Despite the increasing popularity of endoscopic approaches in gynaecological, general and thoracic surgery, until recently no routine endoscopic cardiac surgery was being undertaken. There are several reasons why this may have been so, not the least of which is that endoscopic cardiac surgery is technically challenging. Difficulties include lack of depth perception while translating three-dimensional anatomy to two-dimensional images, especially with a moving target, leading to disconnected hand–eye coordination. The small working port through which instruments are introduced offers a limited range of motion and sensory feedback, with a loss of intuitive dexterity and a reduction in tactile cues. Most cardiac surgery takes place with the patient on cardiopulmonary bypass (CPB), which has to be instituted remotely via peripheral vessels if using port access. Furthermore, valve replacement or repair surgery entails tying large numbers of knots, which have to be accurately positioned and securely tightened intracorporeally. These factors inevitably increase the duration of any procedure over a more conventional approach and, despite modern methods of myocardial protection, the duration of cardioplegic arrest still influences the outcome of a cardiac operation. All of these considerations coupled with the already established excellent long-term results of conventional open first-time cardiac operations have led to some groups suggesting that endoscopic cardiac surgery is unnecessary and unsafe.

Endoscopic (port access) cardiac surgery was originally attempted as a method of performing coronary artery bypass grafting (CABG) in the 1990s when it was known as MIDCAB (minimally invasive direct coronary artery bypass).2 The cardiopulmonary bypass technique employed during MIDCAB involved cannulae inserted into peripheral arteries and veins such as the femoral and jugular vessels. Cardiac arrest was achieved with an endo-aortic balloon occlusion cannula inflated under radiographic guidance (subsequently employing transoesophageal echo guidance) in the ascending aorta, in place of an aortic cross clamp. Cardioplegia was then delivered into the aortic root via a central channel in the end-balloon. MIDCAB subsequently fell out of favour when the multiple incision sites required during access for multi-vessel grafting actually made a sternotomy an easier, safer and less invasive technique.

Despite abandoning endoscopic coronary artery operations, mainland Europe and USA continued to use the endoaortic balloon occlusion techniques, with an operating port via a limited right anterior thoracotomy, for mitral and tricuspid valve procedures. In the UK this approach was not popularized for reasons that remain unclear. A possible explanation relates to industry. Difficulties in procuring funding by NHS purchasers for the additional (high) cost of these disposable cannulae and possibly the reluctance of cardiac surgeons in the UK to embark on potentially hazardous new procedures in the post-Bristol era, led to a low volume of the port access coronary procedures being performed. This in turn made the necessarily expensive, industry-run programme for learning how to deploy these cannulae ineffective in terms of cost. The single company manufacturing the cannulae focused increasingly less on the UK and more on mainland Europe and the USA as these factors became apparent. Consequently, as endoscopic mitral valve surgery became more widely adopted elsewhere, it failed to find a place in UK (personal communication, D Walker, Director of Sales, Heartport Inc).

By year 2000 there were well-developed endoscopic valve programmes throughout mainland Europe but no such activity was taking place in the UK.3,4 Faced with a number of complex redo mitral procedures and recognizing the high risk associated with these operations when performed via a sternotomy (14.3% operative mortality), we decided to develop a port access mitral valve programme as we believed that avoiding incision through the frozen anterior mediastinum in such patients would reduce the associated mortality and morbidity.5,6 We have described our earlier techniques, as learned in Barcelona and Aalst, elsewhere.7 We have refined these over the last 4 years as technology has advanced. Cardiopulmonary bypass is now achieved entirely percutaneously using Seldinger techniques. The endoscope is now held rigidly in place and controlled precisely by use of a surgical robot. In order to reduce the cost of disposables and to ensure a more easily placed and secure method of aortic occlusion, a trans-thoracic aortic Chitwood clamp is now favoured over the endo balloon occlusion clamp for all surgery.

A great expansion in cardiac surgical technology was seen from the 1950s to 1970s. New developments in the specialty have appeared to slow down as clinical governance and cost issues have become increasingly important over the last two decades. In the UK, politically driven initiatives to increase cost efficiency in the NHS have been reported to have had a major and largely negative impact on academic surgery, research and training such that few surgeons have had the opportunity to apply new techniques.8,9 Paradoxically, the latest 'choice'-related political initiatives in the NHS will now lead to patients deciding what type of operation they want. As patient choice increases we anticipate an increased demand for minimally invasive procedures such as endoscopic valve surgery, which together with the current fall in numbers of coronary bypass procedures, may renew interest by UK surgeons who have lagged well behind their European and North American counterparts in this field.