Objective To investigate the feasibility of a long-term left ventricular assist device placed in the aortic valve annulus for terminal cardiopathy. Methods An implantable aortic valve pump （23ram outer diameter, weighing 31g） was developed. There were a central rotor and a stator in the device. The rotor was consisted of driven magnets and an impeller, the stator was consisted of a motor coil with an iron core and outflow guide vanes. The device was implanted identical to an aortic valve replacement, occupying no additional anatomic space. The blood was delivered directly from left ventricle to the aortic root by aortic valve pump like natural ventricle, neither connecting conduits nor ＂bypass＂ circuits were necessary, therefore physiologic disturbances of natural circulation was less. Results Aortic valve pump was designed to cycle between a peak flow and zero net flow to approximate systole and diastole. Bench testing indicated that a blood flow of 7L/min with 50 mmHg（1kPa = 7.5mmHg） pressure could be produced by aortic valve pump at 15 000r/min. A diastole aortic pressure of 80mmHg could be maintained by aortic valve pump at 0L/min and the same rotating speed. Conclusions This paper exhibits the possibility that an aortic valve pump with sufficient hemodynamic capacity could be made in 23mm outer diameter, 31g and it could be implantable. This achievement is a great progress to extend the applications of aortic valve pump in clinic and finally in replacing the natural donor heart for heart transplantation. Meanwhile, this is only a little step, because many important problems, such as blood compatibility and durability, require further investigation.
Transcatheter aortic valve replacement (TAVR) is a mature technology. Because of the complicated valvular anatomy and the severe non-symmetrical valve calcification, the patient with bicuspid aortic valve stenosis (BAVs) once having a lower procedure successful rate, was considered as the relative contradiction for TAVR. However, with the application of the skirted and retrievable next generation prosthesis system, the outcomes of the treatment have been greatly improved. In this article, we summarized the current situation of TAVR applied in BAVs, and the outcomes difference of the old and new generation prosthesis systems.
ObjectiveTo summarize the indication and surgical experiences of valve replacement, high-risk factors and long-term results for aortic regurgitation and large left ventricle. MethodsWe retrospectively analyzed the clinical data of 42 patients with aortic regurgitation and left ventricle end-diastolic diameter (LVEDD) ≥70 mm and left ventricle end-systolic diameter (LVESD) ≥ 50 mm in our hospital from March 2004 through December 2012. There were 38 males and 4 females,aged 16-73 (45.86±14.99) years. The patients underwent aortic valve replacement, who were evaluated by echocardiography at pre-operation, pre-discharge and early follow-up. The follow up period was 12-132 months. ResultsEarly death occurred in one patient. And five patients died during the follow-up. One week after surgery in 41 patients, LVEDD (62.00±13.21 mm), LVESD (50.71±14.02 mm), indexed LVEDD (35.23±8.58 mm/m2), indexed LVESD (28.92±9.08 mm/m2), LVEF (46.41%±12.49%), were significantly smaller than those before the operation (P<0.01). Heart function grades, preoperative EF, LVEDD and indexed LVEDD were the predictors for left ventricular function recovery. One-year, 5-year, 10-year survival rate was 92.9%, 90.2%, 83.8%, respectively. ConclusionMost of patients with aortic regurgitation and large left ventricle still have indications for surgical treatment, but severe left ventricular dysfunction and ventricular arrhythmia are high risk factors for long-term survival.
Transcatheter aortic valve implantation (TAVI) is an important alternative in treating high-risk patients with aortic valve regurgitation. Transcatheter tricuspid valve implantation (TTVI) is also an important treatment option for high-risk patients with tricuspid regurgitation. We reported a 72-year male patient who underwent TAVI due to severe aortic valve regurgitation using a J-Valve. During a two-year follow-up, the patient developed secondary tricuspid regurgitation to atrial fibrillation, and subsequently received TTVI using a LuX-Valve. Following the interventions, the patient's symptoms were significantly improved, and echocardiography indicated good hemodynamic performance of both transcatheter heart valves. This case highlights the feasibility and effectiveness of performing multiple valve implantations via transcatheter approaches in high-risk elderly patients.
Objective To study the development of a physiologic fixation method and investigate the effect of physiologic fixation method on porcine aortic root and aortic valve leaflets. Methods Physiological fixer of aortic root was manufactured in a factory. The fixers with different diameter were made of organic glass. Porcine aortic root with ascending aorta and anterior leaflet of mitral valve and partial ventricular septum were dissected out from the fresh heart. The roots were attached to appropriately sized inflow and outflow spigots. Physiologic fixation was utilized to maintain aortic root and leaflets natural anatomical shape, the aortic root was pressurized to the inflow and outflow portions simultaneously, and the leaflets floated freely at zero-pressure differential with in the pressurized root. Results The process of physiologic fixation retained the properties of a native valve. The leaflets were much softer and extensible than those from valves fixed under low pressure. The results of pulsatile flow testing indicated that the effective orifice areas of predilation at 80mmHg were significantly greater than those of predilation at 40 mmHg（P〈0.05）, while mean pressure differences were found to be lower comparatively（P〈0.05）. This difference translates into a mode of valve function that more closely approximates that of the native aortic valve. Conclusion Physiologic fixation process retains the valve＇s natural anatomical shape as well as the underlying structure of the leaflets, providing improved flow characteristics.
Abstract:The use of pulmonary autograft was first reported in 1967 by Ross for the treatment of aortic valve disease in adults. Since that time, Ross procedure has been applied to a variety of forms of aortic stenosis and left ventricular outflow tract obstruction and mitral valve disease, Ross procedure has undergone several modifications, such as the root replacement method, inclusion cylinder technique, annular reduction, Konno root enlargement procedures and replacement of the mitral valve with a pulmonary autograft （Ross-Kabbani procedure or Ross Ⅱ procedure）. Advantages of Ross procedure in women of childbearing age, children and young adults include freedom from anticoagulation, appropriate sizing, cellular viability with growth potential proportional to somatic growth, acceptable long-term durability, excellent hemodynamic performance and decreased susceptibility to endocarditis. Surgical technical aspects, indications, selection criteria for the Ross procedure and its modifications, their applicability in the surgical management of aortic stenosis, left ventricular outflow tract obstruction and mitral valve disease and clinical outcome of Ross procedure are reviewed in this article.
Cardiac conduction block is one of the most common perioperative complications of transcatheter aortic valve replacement (TAVR), a proportion of which will resolve spontaneously over time, but its incidence has not decreased with the iteration of instruments. It is associated with poor prognosis of patients. The prevention and management strategies of cardiac conduction block after TAVR are still being explored. This paper expounds the mechanism, influence, incidence, predictors, management of cardiac conduction block and indications, timing of permanent pacemaker implantation to provide a reference for the prevention and management of cardiac conduction block after TAVR in clinical practice.
Abstract： Objective To summarize the methods and results of supra-annular aortic valve replacement（AVR） in patients with severely damaged aortic annulus. Methods Supra-annular AVR was performed in 5 patients between March 2008 and Dec. 2010 in Changhai Hospital, Second Military Medical University. There were 4 males and 1 female with their mean age of 46.3 years (ranging from 38 to 53 years). Non-specific infectious diseases were diagnosed in 4 patients who had severe paravalvular leakage after their first AVR operations (2 patients with Behcet’s disease and 2 patients with arteritis), and one patient had severe infectious endocarditis. All the patients had severely destroyed aortic annulus and could not undergo routine AVR. The prosthetic valves were fixed to the aortic sinus wall between the annulus and coronary arterial ostia, and the sutures passed through from the outside of aortic wall into the inside and prosthetic valve ring. Coronary artery bypass grafting was performed if the coronary ostium was involved. Results All patients recovered from the operations uneventfully, and were followed up from 6 months to 3 years. All patients were in New York Heart Association（NYHA） functional class Ⅰ or Ⅱ during the follow-up period, and paravalvalar leakage, pseudoaneurysm and aortic root aneurysm were not found by the examination of 3D computed tomographic angiography and echocardiography at 6 months（4 cases）, 1 year（2 cases）, and 3 years（1 case）, respectively . Conclusions Supra-annular AVR is an alternative surgical method for patients with severely damaged aortic annulus. The procedure is simple and effective to prevent paravalvular leakage and pseudoaneurysm formation.
Abstract: Objective To induce calcification in aortic valvular interstitial cells (VICs) in vitro and observe the shift of cellular phenotype during the process. Methods Porcine aortic VICs were isolated and expanded by collagenase methods. Fluorescent staining was performed to identify the interstitial cells. VICs at 48 passages were used for experiments. The cells were divided into two groups: the experimental group in which cells were cultured in osteogenic media supplemented with βglycerophosphate, vitamin C and dexamethasone, and the control group in which cells were cultured in normal media. After 2 weeks, calcified nodules were quantified. Calcium deposit was stained and measured by Alizarin Red S staining and assay. Real time reverse transcription polymerase chain reaction (RTPCR) was performed to measure expression of alpha smooth muscle actin (α-SMA) and calcification related factors such as osteocalcin, osteopontin and Corebinding factor α1/Runx2 (Cbfα1/Runx2). Results VICs were successfully harvested from porcine aortic valves, identified by positive staining of α-SMA, vimentin and negative staining of Von Willebrand factor (vWF). VICs could calcify after 2 weeks of osteogenic induction with calcified nodules formed. Quantification of calcified nodules and calcification deposit were significantly higher (Plt;0.05) in the experimental group than those in the control group (156.25±17.38 vs. 2.50±1.29, 17.52±2.04 vs. 1.00±0.22). Real Time RT-PCR indicated that expression of α-SMA, as well as calcification related markers like osteocalcin, osteopontin and Cbfα1/Runx2 was much higher in the experimental group than those in the control group (Plt;0.05). Conclusion VICs are activated during the progress of calcification with phenotype shifting to contraction and ossification, which might be the pathological basis of valvular calcification.
Abstract： Objective To investigate the longterm complications and preventions of rapid twostage arterial switch operation through longterm follow-up. Methods We reviewed the clinical information of 21 patients of rapid twostage arterial switch operation from September 2002 to September 2007 in Shanghai Children’s Medical Center. Among them, there were 13 males and 8 females with an average age of 75 d (29-250 d) and an average weight of 5 kg (3.5-7.0 kg). The data of left ventricle training period and the data before and after the twostage arterial switch operation were analyzed, and the risk factors influencing the aortic valve regurgitation were analyzed by the logistic multivariable regression analysis. Results The late diameter of anastomosis of pulmonary and aortic artery were increased compared with those shortly after operation (0.96±0.30 cm vs. 0.81±0.28 cm, t=-1.183,P=0.262; 1.06±0.25 cm vs. 0.09±0.21 cm, t=-1.833,P=0.094), but there was no significant difference. The late velocity of blood flow across the anastomoses was not accelerated, which indicated no obstruction. The late heart function was better than that shortly after operation, while there was no significant difference between left ventricular ejection fraction(LVEF) during these two periods (62.88%±7.28% vs. 67.92%±7.83%,t=1.362,P=0.202). The late left ventricular end diastolic dimension(LVDd) was significantly different from that shortly after operation (2.16±0.30 cm vs.2.92±0.60 cm，t=-5.281，P=0.003). Compared with earlier period after operation, the thickness of left ventricular posterior wall thickness（LVPWT）was also increased (0.39±0.12 cm vs. 0.36±0.10 cm,t=0.700,P=0.500), but there was no significant difference. The postoperative aortic valve regurgitation was worsened in 4 patients (30.77%, 4/13), not changed in 7 patients and alleviated in 2 patients compared with that before operation. There was no severe regurgitations during the followup. The logistic regression analysis showed that the small preoperative diameter ratio of aortic valve to pulmonary valve and long follow-up time were two risk factors for the [CM(159mm]aggravation of aortic regurgitation. Conclusion There is a relatively high aortic regurgitation rate after rapid two stage arterial switch operation, but there is no later death or reoperation and the survival conditions are satisfactory. All patients must be followed up periodically to check the anastomosis of pulmonary and aortic arteries and the aortic valve.