Valve preserving surgery in patients with bicuspid aortic valve

Bicuspid aortic valve can be associated with clinically important aortic regurgitation and dilatation of ascending aorta. Aortic valve repair seems to be optimal therapeutic option how to avoid valve-related and anticoagulation-related complications. We have analyzed midterm outcomes of patients after bicuspid aortic valve repair.MethodsBetween January 2008 and December 2015, 91 patients (mean age 40.9 ± 12.2) with bicuspid aortic valve (type 0 or 1) underwent valve-sparing surgery for aortic valve insufficiency or aortic aneurysm. Urgent procedures and patients of age more than 65 were not included. The cohort of patients was retrospectively divided into two groups. Forty-nine patients underwent aortic valve-sparing procedure with root replacement (group 1). Forty-two patients underwent aortic valve repair without root replacement (group 2). The mean length of follow-up was 57.5 months.ResultsThere was no death in connection with aortic valve repair during follow up. Three patients from group 2 required in-hospital reoperation for early repair failure. Another seven patients (4 from group 1 and 3 from group 2) were reoperated for recurrent aortic insufficiency during follow-up period. Freedom from aortic valve reoperation at 5 years was 90% in group 1 and 87% in group 2. Freedom from recurrent aortic insufficiency (>2°) at 5 years was 85% in group 1 and 78% in group 2.ConclusionBicuspid aortic valve repair is a safe procedure, which can be performed with acceptable midterm results. Risk of repair failure depends on preoperative valve morphology and choice of repair technique. Repair technique needs to be tailored to the specific anatomy of the valve.     

Aortic valve repair in patients with aortic regurgitation: Experience with the first 100 cases

IntroductionThe aim of this study was to analyze short- and mid-term results of aortic valve repair.Material and methodsOne hundred consecutive patients (24 females; mean age 50.3 years, range 23–77 years) with aortic regurgitation underwent aortic valve repair between November 2007 and October 2012. Sixty patients had bicuspid aortic valve, and 82 patients demonstrated aortic regurgitation greater than mild (> grade 2). The ascending aorta/aortic root was replaced in 67 patients. Aortic cusp repair was necessary in 74 patients and additional aortic annulus stabilization was required in 48 cases. Follow-up ranged from 1 to 59 months (cumulative of 220 patient-years, median 25 months) and was complete in 100%.ResultsThere was no 30-day mortality and two patients died in the follow-up. The overall 4-year survival was 98% and freedom from cardiac death was 99% at 4 years. During the follow-up eight patients underwent aortic valve-related reoperation due to progression of aortic regurgitation and another six patients showed aortic regurgitation more than mild (> grade 2). In both aspects there was no statistically significant difference between patients without and with aortic root replacement (p=0.402 and p=0.650). There were no significant bleeding or thromboembolic events during the follow-up.ConclusionsShort- and mid-term data analysis revealed an excellent survival and acceptable results of aortic repair, comparable with other larger published studies. We think, therefore, aortic valve repair should be a part of contemporary cardio-surgical armamentarium, especially in younger patients with an appropriate indication.     

Multiple pseudo-abscesses following aortic valve replacement.

Prosthetic aortic valve endocarditis is associated with valve ring abscess, conduction abnormalities and a grave prognosis. Aortic root abscess is a serious complication of infective endocarditis with high mortality. We report a case of a patient who had echocardiographic features resembling aortic root abscess along with severe aortic regurgitation, 6 weeks following aortic valve replacement. Valvular dehiscence led to perivalvular abscess like appearance. Infective endocarditis was exluded. He underwent a successful redo aortic valve surgery with slow recovery.     

主动脉根部瘤合并二尖瓣病变的外科治疗

目的:总结主动脉根部瘤合并二尖瓣病变的外科治疗经验。方法:2009年2月至2011年12月,我科实施主动脉根部替换手术合并二尖瓣置换/成形术38例。主动脉根部2例行Wheat术,其余均行Bentall术;二尖瓣6例行二尖瓣成形术(MVP),32例行二尖瓣置换术(MVR)。同期行冠状动脉旁路移植术(CABG)2例,孙氏手术4例。结果:围手术期死亡1例,病死率2.6%(1/38);1例患者发生Ⅲ°房室传导阻滞,术后植入永久起搏器;1例患者接受主动脉内球囊反搏(IABP)治疗,2例患者接受连续性肾脏替代治疗(CRRT),1例患者并发真菌感染。2例患者因术后引流多行二次开胸探查术。术后超声心动图:左心室舒张末期内径(55±11)mm(36-83mm),较术前明显缩小。结论:主动脉根部联合二尖瓣手术治疗是安全有效的,对于主动脉瓣环较大的患者,经主动脉瓣口行二尖瓣手术能够取得满意的结果。     

Prolapse of the "floppy" aortic valve as a cause of aortic regurgitation. A clinico-morphologic study

A clinico-pathologic study was performed in 25 patients undergoing aortic valve replacement because of regurgitation, caused by myxoid degeneration of the valve leaflets. Associated cardiac anomalies were floppy mitral valve (2 cases), floppy mitral valve and idiopathic hypertrophic subaortic stenosis (1), left atrial myxoma (1), and aortic coarctation at the isthmus (1). Three patients died (2 immediately and 1 on the 30th postoperative day). Pathological studies of the explanted valves showed deformities characterized by redundant thin leaflets which appeared soft and gelatinous. On histologic examination the fibrous layer of the leaflets was seen to be infiltrated by myxomatous tissue. Echocardiography showed the aortic root to be dilated in 13 patients and normal in the others. In those with normal aortic root, the histological examination of aortic wall disclosed minimal cystic medial necrosis in two cases. In contrast, more severe forms of cystic medial necrosis were evident in all patients having a dilated aortic root. Aortic valve replacement was performed in all cases. It was accompanied by a Bentall procedure (1 case), repair of ascending aorta dissection (2), replacement of the ascending aorta (1), mitral valve replacement (2), mitral valve replacement and apico-ascending aorta conduit (1) and excision of a left atrial myxoma (1). Our experience suggests that prolapse of the aortic valve due to floppy leaflets is a common degenerative disease which is generally associated with noninflammatory aortic root degeneration. This, together with aortic root dilatation, contributes to valve insufficiency. Nevertheless, the disease, when isolated (with normal aortic root), is liable in itself to produce aortic regurgitation. The need for early diagnosis is stressed, so as to be able to perform valve replacement.     

Aortic root dilation prior to valve opening explained by passive hemodynamics

BACKGROUND AND AIM OF STUDY: During the June 1999 World Symposium on Heart Valve Disease, the mechanism by which the aortic valve opens was discussed. It was suggested, indirectly, that the recently discovered contractile elements within the aortic valve may be responsible. We propose that aortic root dilation does not require any active mechanism within the leaflets or aortic wall, and provide an explanation based entirely on the passive hemodynamics of the aortic valve and root. METHODS AND RESULTS: Previous studies using cine fluoroscopy and sonomicrometry have reported a 5-7% expansion of the aortic root during ventricular contraction, prior to aortic valve opening. Simplified force calculations indicate that the mechanical interactions between the aortic valve and root produce an inward pull on the commissures, constraining the aorta from fully dilating. During systole, as the pressure in the ventricle increases and the aortic valve becomes unloaded, the inward pull on the commissures is reduced and the aorta is able to dilate fully. Aortic dilation therefore occurs before the aortic valve opens. CONCLUSION: We conclude that this mechanism of aortic root dilation prior to valve opening is purely passive, and does not require any active process by the aortic valve or the aortic root.     

The role of transesophageal echocardiography in aortic valve preserving procedures

In selected cases of aortic regurgitation, aortic valve (AV) repair and AV sparing root reconstruction viable alternatives to aortic valve replacement. Repair and preservation of the native valve avoids the use of long-term anticoagulation, lowers the incidence of subsequent thromboembolic events and reduces the risk of endocarditis. Additionally repair has a low operative mortality with reasonable mid-term durability. The success and longer term durability of AVPP has improved with surgical experience. An understanding of the mechanism of the AR is integral to determining feasibility and success of an AVPP. Assessment of AV morphology, anatomy of the functional aortic annulus (FAA) and the aortic root with transesophageal echocardiography (TEE) improves the understanding of the mechanisms of AR. Pre- and intra-operative TEE plays a pivotal role in guiding case selection, surgical planning, and in evaluating procedural success. Post-operative transthoracic echocardiography is useful to determine long-term success and monitor for recurrence of AR.     

Successful repair of a large aortic abscess causing apical displacement of the anterior mitral valve

Anatomic continuity between the anterior mitral leaflet and the aortic root may predispose those patients with aortic root pathology to functional changes of the mitral valve without any involvement of this valve. A 34-year-old man presented with aortic valve endocarditis. Transthoracic echocardiograpy showed severe aortic regurgitation with a large aortic root abscess. The anterior leaflet of the mitral valve was displaced towards the apex of the heart causing moderate mitral regurgitation. The patient underwent aortic valve replacement with reconstruction of the aortic annulus and ventriculoaortic continuity. This procedure alone restored the mitral valve structure and function without any need for intervention on the mitral valve. Aortic abscess is a serious complication of aortic valve endocarditis and may alter the function of other structures of the heart, especially the mitral valve. Restoration of aortic wall integrity and left ventricular – aortic continuity usually restores the mitral valve structure and function if the valve is unaffected by the infection. A decision on the mitral valve should be made following correction of the aortic pathology.     

Minimally invasive aortic valve surgery

Aortic valve disease is a prevalent disorder that affects approximately 2% of the general adult population. Surgical aortic valve replacement is the gold standard treatment for symptomatic patients. This treatment has demonstrably proven to be both safe and effective. Over the last few decades, in an attempt to reduce surgical trauma, different minimally invasive approaches for aortic valve replacement have been developed and are now being increasingly utilized. A narrative review of the literature was carried out to describe the surgical techniques for minimally invasive aortic valve surgery and report the results from different experienced centers. Minimally invasive aortic valve replacement is associated with low perioperative morbidity, mortality and a low conversion rate to full sternotomy. Long-term survival appears to be at least comparable to that reported for conventional full sternotomy. Minimally invasive aortic valve surgery, either with a partial upper sternotomy or a right anterior minithoracotomy provides early- and long-term benefits. Given these benefits, it may be considered the standard of care for isolated aortic valve disease.     

保留主动脉瓣主动脉根部替换术的临床应用评价

目的评价保留自身主动脉瓣的主动脉根部替换的可行性和疗效。方法自1998年1月至2004年9月,对我院24例主动脉病变导致主动脉瓣关闭不全但瓣膜本身无明显异常的患者,实施了保留主动脉瓣的主动脉根部替换术,并术后随访观察主动脉瓣反流和心功能改善情况。结果全组无住院死亡。除1例仍为中度反流外,术后主动脉瓣反流均明显改善。随访中有2例非手术相关死亡,无主动脉瓣反流需再次手术者。全组心功能恢复满意。结论主动脉根部替换手术时,对由于主动脉根部瘤或升主动脉瘤导致的主动脉瓣反流者,可优选采用保留主动脉瓣的主动脉根部替换术。     

In vitro study of coronary flow occlusion in transcatheter aortic valve implantation

Background

Transcatheter aortic valve implantation (TAVI) has been developed recently for patients with high morbidities and who are believed to be not tolerate standard surgical aortic valve replacement. Nevertheless, the TAVI is associated with complications such as potential obstruction of coronary ostia, mitral valve insufficiency, and stent migration although it seems promising. Impairment of the coronary blood flow after TAVI is catastrophic and it was believed to be associated with the close position of the coronary orifice and the aortic leaflets and valve stent. However, few data was available as to the anatomic relationship between valve stent and aortic root anatomic structures including the coronary arterial ostia, aortic leaflets.

Methods

The aortic roots were observed in 40 hearts specimens. The width of aortic leaflet, height of aortic sinus annulus to the sinutubular junction (STJ), distance between aortic sinus annulus to its corresponding coronary ostia, and coronary arterial ostia to its corresponding STJ level were measured. Moreover, the relationships of valve stent, aortic leaflets and coronary ostia before/post stent implantation and after the open of aorta were evaluated respectively.

Results

Approximate three quarters of the coronary ostia were located below the STJ level. The mean distances from left, right and posterior aortic sinus annulus to the related STJ level was comparable, which was 18.5±2.7, 18.9±2.6, 18.7±2.6 mm, respectively. Meanwhile, the height of left and right aortic sinus annulus to its corresponding coronary ostia was 16.6±2.8 and 17.2±3.1 mm for left and right side respectively.

Conclusions

Most of the coronary ostia were located below the STJ level and could be covered by the leaflets. This highlights the need of modified stents to prevent occlusion of coronary flow after TAVI.     

Aortic elasticity and size in bicuspid aortic valve syndrome.

AIMS: To investigate the relation between aortic elastic properties and size in bicuspid aortic valves (BAVs). METHODS AND RESULTS: 127 BAV outpatients (121 males; age 23 +/- 10 years) with no or mild valvular impairment, were recruited with 114 control subjects comparable for age, gender, and body size. Aortic distensibility (DIS) and stiffness index (SI) were derived by M-mode evaluation of the aortic root together with blood pressure measured by cuff sphygmomanometer. BAVs vs. controls had increased aortic diameter (P < 0.0001), higher systolic (P = 0.02) and pulse (P = 0.04) pressures. DIS was lower in BAVs than in controls (4.71 +/- 3.67 vs. 7.44 +/- 3.94 10(-6) cm(2)dyne(-1), respectively; P < 0.0001) and SI was greater in BAVs (7.21 +/- 4.93 vs. 3.57 +/- 1.88, respectively; P < 0.0001). Definite impairment in aortic elasticity was present in 53 (42%) BAVs. Both DIS and SI were related (P < 0.0001) to aortic size in BAVs and controls. After adjusting for aortic size and blood pressure, the regression relations between SI and aortic diameter of BAVs were significantly different from controls (P = 0.0052). CONCLUSION: Abnormal aortic elasticity is a common finding in BAVs with no or mild aortic valve impairment. However, impaired aortic stiffness is not due to aortic dilation. Simple assessment of aortic size may thus fail to identify early abnormal load bearing characteristics of the aortic wall in BAVs.     

Results of valve preservation and repair for bicuspid aortic valve insufficiency

BACKGROUND AND AIM OF THE STUDY: There is increasing interest in aortic valve-sparing and repair techniques for the treatment of aortic insufficiency (AI) and/or root aneurysm. The results of bicuspid aortic valve (BAV) repair at the authors' institution were evaluated. An attempt was made to assess the mode of failure and to identify surgical methods that provide durable repair results. METHODS: Aortic valve repair for BAV was performed in 71 patients (62 men, nine women; mean age 41.5 +/- 13.2 years) between 1993 and 2005. Repair techniques included cusp free margin plication (n = 47), subcommissural annuloplasty (n = 27), free margin reinforcement (n = 10), and cusp triangular resection (n = 7). Thirteen patients had remodeling of one or both aortic sinuses, and 16 had reimplantation of the aortic valve. The ascending aorta and arch were replaced in 29 and five patients, respectively. Concomitant mitral and coronary bypass surgeries were performed in 10 and three patients, respectively. RESULTS: There were no operative deaths. Early postoperative echocardiography revealed no or trace AI in 54 patients and mild AI in 17. There was only one late death which was non-cardiac-related. Eight-year freedom from endocarditis, thromboembolism and anticoagulation-related hemorrhage was 90%, 100% and 100%, respectively. Eight-year freedom from AI grade > or =3+ (moderate) and aortic valve replacement were 44% and 82%, respectively. At the latest follow up, 89% of patients were in NYHA functional class I. Patients who underwent aortic valve-sparing procedures had more stable valve function than those who had cusp repair and subcommissural plication. CONCLUSION: BAV repair is a safe procedure with good early functional results. However, recurrent AI remains a problem at five to eight years of follow up. Since dilation of the aortic root is a common cause of AI and a common feature of patients with BAV, aortic valve-sparing reimplantation operations should provide better long-term outcomes.     

主动脉瓣人工瓣膜置换术156例分析

目的总结成人主动脉瓣人工机械瓣膜置换手术的经验.方法1996年1月至2005年1月对156例成人行主动脉瓣置换,术中均行人工机械瓣膜置换,其中双叶瓣125例,单叶瓣31例.13例行瓣膜侧倾缝合,6例行主动脉瓣瓣环加宽.结果存活151例,死亡7例,死亡率4.48%.结论对主动脉瓣膜行人工机械瓣瓣膜置换手术术前充分估计瓣环大小,术中良好的灌注、心肌保护、选择合适瓣膜和恰当手术方法,可降低死亡率.     

Etiology of bicuspid aortic valve disease: Focus on hemodynamics

The bicuspid aortic valve (BAV) is the most common form of inheritable cardiac defect. Although this abnormality may still achieve normal valvular function, it is often associated with secondary valvular and aortic complications such as calcific aortic valve disease and aortic dilation. The clinical significance and economic burden of BAV disease justify the need for improved clinical guidelines and more robust therapeutic modalities, which address the root-cause of those pathologies. Unfortunately, the etiology of BAV valvulopathy and aortopathy is still a debated issue. While the BAV anatomy and its secondary complications have been linked historically to a common genetic root, recent advances in medical imaging have demonstrated the existence of altered hemodynamics near BAV leaflets prone to calcification and BAV aortic regions vulnerable to dilation. The abnormal mechanical stresses imposed by the BAV on its leaflets and on the aortic wall could be transduced into cell-mediated processes, leading ultimately to valvular calcification and aortic medial degeneration. Despite increasing evidence for this hemodynamic etiology, the demonstration of the involvement of mechanical abnormalities in the pathogenesis of BAV disease requires the investigation of causality between the blood flow environment imposed on the leaflets and the aortic wall and the local biology, which has been lacking to date. This editorial discusses the different hypothetical etiologies of BAV disease with a particular focus on the most recent advances in cardiovascular imaging, flow characterization techniques and tissue culture methodologies that have provided new evidence in support of the hemodynamic theory.     

瓣叶增补法在主动脉瓣成形术中的应用

目的 探讨瓣叶增补技术在主动脉瓣成形术中应用的效果.方法 2007年1月至2009年12月,应用瓣叶增补法完成主动脉瓣成形术26例,患者平均年龄11.5岁.术前四肢动脉压差58～103 mm Hg.主动脉瓣病变包括瓣叶脱垂或感染性心内膜炎造成的瓣叶损害;彩色多普勒显示主动脉瓣有中-重度反流.全组均在病变瓣叶边缘缝合心包片增补瓣叶形成正常瓣兜,使三个瓣叶边缘对合良好.结果 全组无手术及术后早期死亡.术后全组均无心力衰竭发生,动脉压差36～51 mm Hg.彩色超声心动图提示主动脉瓣无明显反流5例,有微少反流12例、轻度反流9例.随访3～38个月,复查超声心动图显示主动脉瓣无反流加重者.结论 瓣叶增补技术能有效地减少或避免主动脉瓣反流.     

Hemodynamic study of the effect of the geometric height of leaflets on the performance of the aortic valve under aortic valve reconstruction

BackgroundAlthough aortic valve reconstruction has become an alternative treatment for aortic valve disease, the design of the geometric parameters of the reconstructed leaflet still mainly depends on the experience of doctors. The present study investigates the effects of the height of the leaflets on the performance and biomechanical states of the reconstructed aortic valve.MethodsThis numerical study was carried out using the finite element approach and the lattice Boltzmann method. The dynamic and biomechanical characteristics of the leaflets were evaluated by using the finite element approach, while the blood flow in the aortic sinus was evaluated by applying the lattice Boltzmann method. Three types of leaflets with different heights were designed. Then the dynamic characteristics, stress distribution, and effective orifice area (EOA) of the aortic valve and flow pattern were calculated as the indicators.ResultsThe results demonstrated that the height of the leaflets could indeed regulate the performance and the biomechanical states of the aortic valve. The rapid valve opening times of the 3 types of leaflets gradually reduced along with the decrease of the height ratio (HR_0.8: 120 ms vs. HR_1.0: 68 ms vs. HR_1.2: 31 ms), while the rapid valve closing times (RVCTs) of the 3 types of leaflets were similar to each other (approximately 75 ms). Moreover, the radial displacement of the leaflet at the fully open time increased along with the decrease of the HR of the leaflets (HR_0.8: 8 mm vs. HR_1.0: 6 mm vs. HR_1.2: 4 mm). In addition, the stress level of the leaflets also increased with the increase of the height of the leaflets (max stress, HR_0.8: 0.5 MPa, vs. HR_1.0: 1.1 MPa, vs. HR_1.2: 1.8 MPa). Similarly, the low velocity region near the ascending aortic wall and the wall shear stress (WSS) level on the ventricular side of the leaflets also increased along with the increase of the HR of the leaflets.ConclusionsIn short, the height of the leaflets mainly affects the opening performance of the reconstructed aortic leaflets. The HR of the reconstructed leaflets for adults should be less than 1.0 to balance the opening and closing performance of aortic leaflets.     

Aortic dimensions in patients with bicuspid aortic valve without significant valve dysfunction

The dimensions of the entire aorta at different anatomic levels were measured by transthoracic 2-dimensional echocardiography in 162 consecutive patients with isolated bicuspid aortic valves (BAVs) without significant aortic valve dysfunction. Aortic dilation involved the aortic root and the ascending aorta but was not present in the descending and abdominal aorta. A significant increase in the dimensions of the aortic arch was found in patients with BAVs aged >40 years. Ascending aortic diameter and the extension of aortic dilation were significantly correlated with age, but no correlation was found between aortic dimensions and aortic valve morphology.     

Rates and determinants of progressive aortic valve dysfunction in aortic coarctation

Purpose

Aortic valve dysfunction is common in coarctation patients(CoA). Bicuspid aortic valve (BAV) in CoA is associated with aortic valve stenosis (AS), aortic valve regurgitation (AR), and ascending aortic dilatation. The aim of this study was to evaluate the progression of and predictors for aortic valve dysfunction in CoA.

Methods

96 CoA patients prospectively underwent echocardiography twice between 2001 and 2010. AS was defined as an aortic valve gradient ≥ 20 mm Hg, AR as none/minor, or moderate/severe. Aortic dilatation as an ascending aortic diameter ≥ 37 mm.

Results

All patients (median age 28.0 years, range 17–61 years; male 57%) were followed with a median follow-up of 7.0 years. Sixty patients (63%) had BAV. At baseline 10 patients had AS (10%, 9 BAV), 6 patients AR (6%, 3 BAV) and 11 patients aortic dilatation (11%, 11 BAV). At follow-up 15 patients had AS (15%, 13 BAV) and 12 patients AR. (13%, 8 BAV).Median AS progression was 1.1 mm Hg/5 years (range — 13–28). Determinants for AS at follow-up were age (ß = 0.20, P = 0.01), aortic dilatation (ß = 4.6, P = 0.03), and baseline aortic valve gradient (ß = 0.93, P < 0.001). BAV was predictive for AR. (ß = 0.91, P = 0.049).

Conclusion

Progression of AS in adult CoA patients is mild in this young population. Older age, aortic dilatation and the baseline aortic valve gradient are determinants for AS at follow-up. BAV is predictive for AR. These findings point towards a common embryological pathway of both valvular and aortic disease in CoA.     

Congenital quadricuspid aortic valve in children

Quadricuspid aortic valves are rare congenital anomalies, usually diagnosed in adult patients affected by severe aortic regurgitation. We have now encountered three such valves in children undergoing transthoracic echocardiography. All children were asymptomatic. The first child possessed a valve with two larger leaflets, and smaller leaflets of equal size. In the second child, 3 leaflets were of equal size, with 1 small accessory leaflet. The third child had a valve with four leaflets of approximately equal size. In one child, the aortic valve was functioning normally, and came to attention because of mitral valvar prolapse causing mild regurgitation. In the remaining two children, central mild aortic regurgitation was detected using colour flow analysis, and associated dilation of the aortic root was revealed by measurements of the cross-sectional images.