In another first for two leading Western Cape heart units, a team of specialists from Vergelegen Medi-Clinic and Panorama Medi-Clinic jointly performed highly sophisticated aortic valve implantation procedures on five high-risk patients.
These transcatheter aortic valve implants enable specialists to replace diseased aortic valves in severely ill patients affected by aortic stenosis. The procedure is accomplished in a minimally invasive way, while the heart continues to beat and without the use of a heart-lung machine.
Aortic stenosis is commonly described as the narrowing of the aortic valve opening that results in lower blood flow through the valve. Patients suffering from aortic stenosis generally present with symptoms such as chest pain, fatigue, shortness of breath, light-headedness or fainting, or difficulty when exercising.
Comprehensive studies in the United States, Europe and Canada have enrolled more than 3 000 patients to date. It was, however, performed for the first time in Africa during October. Vergelegen Medi-Clinic and Panorama Medi-Clinic were identified as the preferred venues for these initial training cases due to their recognised and well-established heart units and the highly-regarded and experienced heart specialists associated with them.
Dr Tom Mabin, cardiologist at Vergelegen Medi-Clinic and team leader of this specialist group, explained the process: During this procedure a prosthetic transcatheter valve is positioned either via transfemoral (via an artery in a patient’s groin) or transapical delivery (via a small chest incision and through the apex of the heart), depending on the patient’s condition. The replacement valve pushes away the diseased valve and, once in place, takes over the valve functionality automatically.
The Edwards SAPIEN® valve was manufactured by United States company Edwards Lifesciences, and received its CE mark in 2007. The valve is a highly sophisticated device constructed from a surgical stainless steel frame and bovine pericardial tissue (the protective sac that surrounds a cow’s heart), and measures either 23 mm or 26 mm depending on the patient's aortic annulus diameter. The valve is crimped down on top of a balloon and delivered via a catheter under careful guidance on a fluoroscopic screen. Once at the site of the diseased valve, the balloon is inflated and the valve expanded into place.
These procedures demand a combined effort by a multidisciplinary team. Our team consisted of two cardiologists, two cardiothoracic surgeons, an anaesthetist, a clinical technologist and various support staff and radiographers, explains Dr Helmut Weich, cardiologist at Panorama Medi-Clinic and Tygerberg Hospital, where he is involved with the training of future cardiologists in the Faculty of Health Sciences, Stellenbosch University.
The team underwent rigorous training in Switzerland as part of a bigger group of 21 specialists from South Africa in August this year. “All future procedures in the Western Cape will be conducted by the same team as a dedicated specialist entity due to the intricate nature of the procedure, in line with international training requirements,” Dr Weich explains.
Drs Mabin and Weich performed the transfemoral deliveries, whilst the two cardiothoracic surgeons, Dr Wynand van Zyl of Vergelegen Medi-Clinic and Dr Jacques van Wyk of Panorama Medi-Clinic, took charge of the transapical deliveries. The anaesthetist was Dr Rocco Viviers of Panorama Medi-Clinic.
“Whilst conventional surgical valve replacement remains the gold standard for patients affected by aortic stenosis, this procedure is considered a breakthrough for elderly and severely ill patients who would generally would not be considered for conventional open-chest surgery due to the risk of surgery posed to them” Dr Mabin explained.
“This is a beating heart procedure and does not require cardiopulmonary bypass. Implant time is also reduced significantly. These procedures are typically performed in less than 45 minutes, and the effect on patients is almost immediate,” Dr Mabin continued.
During these first five training cases, this specialist group was assisted by two specialists from St Thomas Hospital in London, who acted as mentors. The team will be required to perform a total of 20 guided procedures before they will be certified to perform these operations on a continued basis without any mentorship.