Percutaneous aortic valve replacement

  Percutaneous Aortic Valve Replacement (PAVR) is a new, minimally invasive valve replacement technique that has been developed and adopted in recent years. Since the valve is not replaced like a surgical procedure, it has recently become known as transcatheter aortic valve implantation (TVAI). The first and second studies on percutaneous aortic valve replacement were performed by Andersen and others in 1992, and progressive improvements were made to the device.  A. Cribier, a French physician, was the first to treat PAVR in humans in 2002. The PAVR pathway includes the cis (transvenous puncture of the atrial septum via the left atrium-micuspid valve-left ventricle pathway), the retrograde (femoral artery-aortic pathway), and the transcatheter approach.  Currently, the main indications for PAVR are: ①symptomatic severe aortic stenosis (orifice area < 1 cm2 ); ②European Cardiac Surgical Risk Score (EuroSCORE) ≥ 20% or American College of Thoracic Surgeons risk (STS) score ≥ 10%; and anatomic suitability for TAVI (mainly aortic annular internal diameter and peripheral arterial internal diameter in the appropriate range). The vast majority of patients currently enrolled in clinical trials are those who are too old (>70-75 years) and have severe comorbidities to undergo surgery.  To date, more than 35,000 patients worldwide have undergone percutaneous aortic valve replacement. The number of cases reported in recent studies is increasing, and the results of the procedure are becoming more encouraging. The results of large PAVR studies published in the last 2 years show a high success rate for PAVR (between 93.3% and 98.4%) and a 30-day mortality rate of 8.5% to 12.7%. This is still an acceptable mortality rate due to the enrollment of high-risk patients of very high age.  Common complications include atrioventricular block requiring pacemaker placement, stroke, and local vascular complications. Although there are more and rapid progress of TAVI research abroad, our country is late in this aspect of research. Happily, on October 3, 2010, Professor Ge Junbo’s of Zhongshan Hospital of Fudan University has successfully completed the first case of TAVI in China, creating a precedent of PAVR in China.  PAVR has achieved more satisfactory results in the current clinical application, but there are still many problems to be solved. The aortic root anatomy is complex and difficult to operate, the complication rate of stroke and slow arrhythmia is still high, the current technology cannot make the placed stent valve completely adhere to the wall of the autologous aorta, some patients may still have valve displacement and serious perivalvular leakage, there are potential risks of thromboembolism and limited stent life, the surgical instruments are expensive and there are no domestic instruments yet.  However, with advances in materials engineering and the growing experience of surgeons, it is believed that some of the existing technical challenges will be overcome, allowing interventional treatment of aortic valve disease to evolve and even replace valve replacement surgery as a routine procedure,” says Dr. Grube. This has led to a significant improvement in the procedure (with a significant reduction in local vascular complications).  The procedure is less invasive, does not require a ventricular assist device, and does not require general anesthesia or surgical incision preparation, resulting in a significant reduction in operative time. The third-generation valve allows us to achieve a true percutaneous aortic valve replacement, which in the near future will change the standard of care for aortic stenosis, especially for those patients at high surgical risk for active severe aortic stenosis.