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Thoracic aortic aneurysm (TAA) is common among hypertension patients and is one of the top leading causes of death in Hong Kong. Treatments for TAA may include surgical repair or removal of the aneurysm, or the insertion of a covered metallic stent to support the blood vessel and prevent rupture.

The Cardiothoracic Surgery team of The Chinese University of Hong Kong (CUHK)’s Faculty of Medicine (CU Medicine) has been taking a leading role in aortic arch surgery in Asia, providing a testing ground for the latest surgical devices in the field. The team has, for the first time in Asia, performed one-stage hybrid aortic arch surgery on patients with multi-segment aortic diseases using a new E-vita® OPEN NEO device. So far they have treated 25 patients and reported satisfactory outcomes. Results have been published on the Cardiothoracic Surgery Network and in the Journal of Cardiac Surgery.

TAA accounts for 300 deaths every year in Hong Kong

TAA is the second most common aortic disease worldwide after atherosclerosis. It accounts for more than 1,400 hospital admissions and 300 deaths every year in Hong Kong. The CU Medicine team previously reported that the prevalence of TAA among Chinese hypertensive patients was 7.5%. TAA is defined as a permanent dilation of the aorta with an increase of over 50% in diameter relative to the diameter of the adjacent normal segment, or with a diameter of 4.5cm or above.

Dr Jacky Ho Yan-kit, Clinical Assistant Professor (honorary) in the Division of Cardiothoracic Surgery of the Department of Surgery at CU Medicine, explained, “Aortic aneurysm is a silent killer, as 95% of cases carry no symptoms prior to presentation of the lethal complications. Our unit is seeing an increase in the number of aorta-related diseases from about 20 cases per year 10 years ago to currently about 100 cases per year, and there is an increasing incidence of patients aged 50 or below developing aortic dissection.”

CU Medicine’s Cardiothoracic Surgery team is a pioneer in aortic arch surgery in Asia

The aorta is the body’s main artery in a cane shape which carries blood from the heart to other parts of the body. The aortic arch is the winding part of the “cane”, and surgery on it is one of the most complicated procedures among all types of aortic surgery, involving complex neurological perfusion of head and neck vessels, cardiac myocardial protection, and a period of visceral circulatory arrest under cardiopulmonary bypass support. The total aortic arch replacement with frozen elephant trunk (TAR FET) technique is one of the mainstream surgical options for aortic arch surgery developed over recent decades. 

CU Medicine’s Cardiothoracic Surgery team has been a pioneer in aortic arch surgery in Asia. It introduced the first-of-its-kind TAR FET procedure with Thoraflex™ Device in August 2014 and published the results in an international journal in 2020. In October 2020, the team also performed Asia’s first TAR FET procedure using the E-vita® OPEN NEO branched graft via a virtual proctoring platform during the COVID-19 pandemic. The new device has been designed to prevent stent shortening after surgery and has various configurations to adapt different aortic anatomies and diseases.

Dr Takuya Fujikawa, Clinical Assistant Professor (honorary) in the Division of Cardiothoracic Surgery of the Department of Surgery at CU Medicine, commented, “Using the E-vita® OPEN NEO TAR FET device, we have treated 25 patients who usually required multi-stage operations, converting them into a single-stage procedure, in the past two years. Patients who have multiple segments aortic aneurysm involving the ascending, arch and descending thoracic aorta, require multi-stage operations. Conventionally, the first stage is to replace the ascending aorta and the aortic arch, the patient will then need to have a second operation, either endovascular or open descending replacement to treat the aneurysm and avoid further dissection or rupture. The advancement of the surgical graft allowed all these to be done in a single operation. This reduced the number of operations and total hospital stay of patients and achieved 0% mortality with very few complications such as bleeding, stroke or spinal cord injury.”

The CU Medicine team has performed more than 140 arch replacements in the past 10 years. In the initial phase of the adoption of the TAR FET procedure, it achieved an operative mortality of 9%, which was already better than the international results. Dr Fujikawa added that the team has proved virtual proctoring is a feasible approach to introduce new surgical devices, and that detailed pre-operative planning and training, well-executed intra-operative surgical procedure and careful post-operative monitoring are the keys to achieving and maintaining excellent clinical outcomes.

Challenges in introducing new device during COVID-19 pandemic

The training on the new device was performed solely via virtual proctoring amid the COVID-19 pandemic, which researchers described as an unprecedented challenge. Professor Randolph Wong Hung-leung, Professor and Chief in the Division of Cardiothoracic Surgery of the Department of Surgery at CU Medicine, said, “Our team always strives to search for ways to improve our surgical outcomes, and one of the most effective ways is to introduce state-of-the-art devices from around the world. In the past, surgeons travelled to overseas hospitals to receive training as the first stage, followed by on-site training by overseas proctors. However, after travel restrictions were imposed during the pandemic, CU Medicine adopted an innovative approach of using a virtual proctoring platform to conduct procedural planning and intra-operative coaching by a proctor from Germany. The procedure was smooth and the patient outcome is good.”