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.
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.
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 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.
ObjectiveBy comparing the difference between different stenosed degree of aortic valve in flow field uniformity and turbulent shear stress (TSS), to explore the relation between flow field uniformity and different stenosed degree of aortic valve, and probe the clinical value for deciding the operation timing, and analyze the possible role of TSS in the progress of the disease.MethodsThe flow field uniformity values and TSS in parasternal long axis plane and apical five cavity plane on each point were measured and calculated by pulse wave Doppler echocardiography technique for 33 patients with different stenosed degree of aortic valve.ResultsThere were significant difference between the different stenosed degree of aortic valve in maximal velocity difference(ΔV max )and TSS( P lt;0.05, 0.01). The more severe the aortic stenosis was, the worse the flow field uniformity was, the lower the TSS was.ConclusionsThere are significant difference between the patients of different stenosed degree of aortic valve in flow field uniformity. Flow field uniformity has important value in classifying the degree of aortic stenosis and deciding the timing of operation. The more severe the aortic stenosis is ,the lower TSS is. It can be thought that low TSS distribution has important role in pathological process of constriction in cardiovascular system diseases.
Objective To evaluate the effectiveness of unsupported reduction ascending aortoplasty for dilatation of the ascending aorta. Methods Between September 2005 and May 2011, 53 patients with aortic valve disease and dilatation of the ascending aorta underwent aortic valve replacement with unsupported reduction ascending aortoplasty. There were 41males and 12 females, aged 22-75 years (mean, 52 years). The disease duration was 1 month to 14 years. The color Doppler echocardiography showed that the diameter of the ascending aorta before surgery was (45.9 ± 3.3) mm; bicuspid aortic valve and tri-aortic valve were observed in 13 and 40 cases respectively. The heart functions were graded as II level in 19 cases, III level in 33 cases, and IV level in 1 case according to the standard of New York Heart Disease Academy (NYHA). Results After operation, mediastinum errhysis occurred in 1 case, pneumonia in 3 cases, and III degree atrioventricular block in 1 case. There was no related complication of the aortoplasty. All the patients were followed up 3-68 months (mean, 15 months), and had no obvious chest tightness and palpitation. At last follow-up, the NYHA heart functions were graded as I level in 22 cases, II level in 31 cases; the diameter of the ascending aorta was (35.2 ± 4.0) mm, showing significant difference when compared with the preoperative one (P=0.000), but no significant difference when compared with the one at discharge (34.0 ± 2.5) mm (P=0.245). There was significant difference in the diameter of the ascending aorta between last follow-up and preoperation, at discharge in the patients who were followed up more than 60 months (P lt; 0.05); significant difference was found between last followup and preoperation in patients with bicuspid aortic valve (P lt; 0.05), but no significant difference between last follow-up and preoperation (P gt; 0.05) in patients whose diameter of the ascending aorta was more than 50 mm before operation. Conclusion Unsupported reduction ascending aortoplasty has good short- and mid-term results in treating aortic valve disease with mild to moderate dilatation (diameter range, 40-50 mm) of the ascending aorta. Inclusion criteria of the aortoplasty should be strict. Long-term results need further follow-up.
With the development of transcatheter aortic valve replacement, it has become the first-line treatment for elderly patients with aortic valve stenosis. A case of transcatheter aortic valve replacement in a patient at high risk of coronary artery occlusion was reported. The use of intravascular ultrasound to observe the spatial relationship between the coronary ostia and the valve was the characteristic of this case. This patient was an elderly male who was assessed as a high risk of acute coronary artery occlusion before transcatheter aortic valve replacement. After fully evaluation of the patient’s surgical risks\benefits, the strategy was formulated. Percutaneous coronary intervention was the first step. At the same time, intravascular ultrasound was used to observe the spatial relationship between the coronary ostia and the valve, and balloon was embedded for coronary protection. The procedure went smoothly.
ObjectiveTo assess mid- and long-term outcomes and share our clinical method of reduction ascending aortoplasty (RAA) in adult patients undergoing aortic valve replacement (AVR).MethodsWe retrospectively analyzed clinical data of 41 adult patients with aortic valve disease and ascending aortic dilatation before and after operation of RAA+AVR in Fuwai Hospital from January 2010 to July 2017. There were 28 male and 13 female patients aged 28-76 (53.34±12.06) years. Twenty-three patients received AVR+RAA using the sandwich technique (a sandwich technique group), while other 18 patients received AVR+ascending aorta wrap (a wrapping technique group). Ascending aorta diameter (AAD) was measured by echocardiography or CT scan preoperatively and postoperatively.ResultsThere was no perioperative death. The mean preoperative AAD in the sandwich technique group and the wrapping technique group (47.04±3.44 mm vs. 46.67±2.83 mm, P=0.709) was not statistically different. The mean postoperative AAD (35.87±3.81 mm vs. 35.50±5.67 mm, P=0.804), and the mean AAD at the end of follow-up (41.26±6.54 mm vs. 38.28±4.79 mm, P=0.113) were also not statistically different between the two groups. There were statistical differences in AAD before, after operation and at follow-up in each group. All 41 patients were followed up for 23-108 (57.07±28.60) months, with a median follow-up of 51.00 months. Compared with that before discharge, the AAD growth rate at the last follow-up was –1.50-6.78 mm/year, with a median growth rate of 0.70 mm/year, and only 3 patients had an annual growth rate of above 3 mm/year.ConclusionMid- and long-term outcomes of RAA in adult patients undergoing AVR with both methods are satisfying and encouraging.
ObjectiveTo summarize the clinical experience of aortic valve replacement surgery with minimally invasive procedure. MethodsWe retrospectively analyzed the clinical data of 72 patients underwent isolated aortic valve replacement in our hospital between January 2011 and August 2013. The patients undergoing minimally invasive procedure were as a minimally invasive group(30 patients with 18 males and 12 females at age of 60.2±13.4 years). The patients undergoings conventional procedure were as a control group(42 patients with 27 males and 15 females at age of 61.3±14.5 years). The outcomes of the two groups were compared. ResultsThere was no death and severe complication in both groups. Postoperative echocardiography showed no paravalvular leakage, no valve dysfunction in both groups. There were no significant statistically differences between the two groups in cardiopulmonary bypass time, aortic crossclamping time, ventilation time, postoperative left ventricle ejection fraction, the length of ICU stay and hospital stay (P>0.05). Blood transfusion ratio, blood transfusion volume and blood loss volume were lower in the minimally invasive group than those in the control group (P<0.05). The length of incision, chest closure time, operative duration were shorter in the minimally invasive group than those in the control group (P<0.05). ConclusionUpper median sternotomy is a safe and feasible procedure for minimally invasive aortic valve replacement surgery. Compared with conventional aortic valve replacement, its advantages include less surgical trauma, stable sternum, rapid recovery, less blood loss and blood transfusion, and cosmetic outcomes.