Aortic root dilatation may alter the dimensions of the valve leaflets

Objective: Valve-sparing surgery can be used in patients with dilated aortic roots and aortic insufficiency (AI) but has not become a common practice, in part because the spared valve may be incompetent. Our goal was to study how the dimensions of the aortic root and leaflets have changed in such patients. Methods: Fourteen patients with dilated aortic root and AI were examined by transesophageal echocardiography. The annulus diameter, sinotubular junction (STJ) diameter, sinus height, leaflet free-edge length, and leaflet height were measured. Correlations among these dimensions and with the AI grades were explored. Measurements were also made in 19 normal human aortic valves from silicone molds. Results: There was no evident change in the average diameter of the annulus between the normal valves and those in the dilated aortic roots. The STJ diameter was obviously increased in the dilated aortic roots; the aortic sinuses also appeared to be taller and the leaflets larger than normal. The leaflet free-edge length, the leaflet height, and the sinus height were found to increase with the dilated STJ diameter. The degree of AI was not found to correlate well with any of the dimensions measured. Conclusions: The dimensions of the leaflets may change parallel to aortic root dilatation with AI. Therefore, during valve sparing, it may be necessary to correct both the dilatation of the root and the leaflet free-edge length to achieve a competent valve.     

Midterm results after aortic valve-sparing operation

OBJECTIVES: We have conducted aortic valve-sparing operation for patients having aortic root dilatation and almost normal aortic valve leaflets since August 1998, and here report midterm results. METHODS: Patients with dilated aortic annulus or Marfan's syndrome were treated with reimplantation, and the remaining patients with remodeling. Either 24 or 26 mm graft was selected based on aortic annular diameter and leaflet size. Aortic valve competence was assessed regularly with echocardiography. RESULTS: Five patients (age: 29 +/- 13 yr), including 4 with Marfan's syndrome, had undergone reimplantation, and 3 (age: 46 +/- 18 yr) remodeling by December 2000. Mean follow-up was 18 (range: 10-32) months, and no postoperative death has occurred and no reintervention has been required thus far. All the patients in the remodeling group showed only a small pressure gradient through the aortic valve and decreased left ventricular diameter. Two in the reimplantation group showed a pressure gradient exceeding 20 mmHg. Two Marfan's syndrome patients in the reimplantation group showed slightly increased diastolic left ventricular diameter and 3 slightly increased systolic left ventricular diameter. Although aortic regurgitation had diminished in all patients by discharge, moderate aortic regurgitation recurred in 1 non-Marfan's syndrome patient in the reimplantation group because of degenerated aortic valve. CONCLUSION: Although postoperative aortic valve function was not perfect in all patients undergoing reimplantation, midterm results after aortic valve-sparing operation were generally satisfactory. Proper selection of patients, procedures, and graft size was thought to be important to ensure a favorable surgical outcome.     

Correction of discrete subaortic stenosis with abnormal chordae tendineae

The case of a 52-year-old woman with subvalvular aortic stenosis and aortic regurgitation is presented. Mitral regurgitation was associated, due to insertion of two abnormal chordae tendineae at the apex of the anterior papillary muscle and at the free border of the subvalvular membranous annulus. This abnormality displaced the anterior papillary muscle, thus applying a traction at the mitral leaflet. The patient was operated on through a valve-sparing approach, in which the discrete subaortic stenosis was removed through aortotomy and the ectopic chordae were excised. Suture mitral annuloplasty completed the procedure. Aortic and mitral insufficiency almost disappeared at follow-up. From the examination of this case and from a review of pertinent literature it emerges that in event of similar complex congenital abnormalities without intrinsic valve disease, a conservative approach should be chosen so that valve replacement can be avoided.     

Bicuspidization of the tricuspid valve for the treatment of posterior leaflet endocarditis: a case report

Patients who require surgical therapy for the treatment of tricuspid valve regurgitation can avoid undergoing tricuspid valve replacement if valve-sparing repair techniques are employed. Tricuspid valvular endocarditis frequently requires valvectomy, leaving the right side of the heart and pulmonary system vulnerable to unregulated blood flow. We present a case of complete posterior leaflet excision and plication of the involved portion of the tricuspid annulus, which resulted in "bicuspidization" of the valve, for the treatment of tricuspid valve endocarditis localized to the posterior leaflet.     

Echocardiographic characteristics of the cryopreserved allograft aortic valve replacement assessed by intraoperative transoesophageal echocardiography

Improvements in cryopreservation techniques have made possible excellent long-term results using aortic valve allografts. Few studies, however, have examined the echocardiographic characteristics of allograft aortic valves and postoperative valve function. Aortic allograft function was eveluated in 16 patients by intraoperative transoesophageal echocardiography, postoperative catheterization, and angiography. The mean(s.d.) coaptation zone length of the allograft leaflet was significantly greater (7.3(1.4) mm) than that of the normal aortic valve (3.2(0.8) mm) (P < 0.01). No regurgitation was noted in any patients with coaptation zone length of 7–11 mm (P < 0.01). The increment of the leaflet coaptation zone length did not produce a significant pressure gradient during exercise and appeared to be one of the important mechanisms for the prevention of postoperative aortic regurgitation, because commissural orientations may be distorted in the new aortic position. This finding is consistent with the report that allografts with the largest diameter implantable in the recipient annulus should be selected for use.     

Valve-sparing aortic root replacement with repair of leaflet prolapse after Ross operation

The need for reoperation remains a principal limitation of the Ross procedure and most commonly includes replacement of the neo-aortic valve. Valve-preserving aortic root replacement has recently evolved into an increasingly accepted treatment modality for patients with neo-aortic valve regurgitation. Leaflet prolapse, however, may be present, making composite replacement the most frequent choice. Alternatively, valve preservation may be combined with correction of leaflet prolapse. We describe the use of a valve-sparing procedure with correction of leaflet prolapse in a patient with progressive dilatation of the pulmonary autograft and severe regurgitation of the neo-aortic valve.     

Aortic prosthetic ring annuloplasty: a useful adjunct to a standardized aortic valve-sparing procedure?

OBJECTIVE: Dilation of aortic annulus, sinuses of Valsalva, and sinotubular junction (STJ) diameters are the characteristic lesions of aortic root aneurysm. The remodeling technique reduces STJ diameter and creates three neosinuses of Valsalva. Alternatively, the reimplantation technique reduces both annulus and STJ diameters to the detriment of aortic root dynamics. Although the remodeling technique is recognized as the most physiological valve-sparing procedure, aortic annulus dilation may jeopardize its results. A standardized approach that combines an external subvalvular aortic prosthetic ring annuloplasty with the remodeling technique is suggested. METHODS: Eighty-three patients underwent an elective aortic root remodeling procedure, either isolated (group 1, n=34) or combined with an external subvalvular aortic prosthetic ring annuloplasty (group 2, n=49). Preoperative aortic regurgitation was 1.59+/-1.1 (group 1) and 1.97+/-1.3 (group 2) (NS). The aortic annulus was more dilated in group 2 than in group 1 (27+/-2.77 mm vs 26.4+/-2.3 mm, p<0.01). Residual aortic regurgitation > or =grade II was the conversion criteria for aortic valve replacement. RESULTS: Operative mortality was 3.6% (n=3). Intraoperative conversion for valve replacement was 32.7% in group 1 (n=11) versus 4.2% in group 2 (n=2) (p<0.001). In group 1, preoperative annulus diameter was larger for converted than for valve-spared patients (27.6+/-1.7 mm vs 25.2+/-1.5 mm, p<0.02). In group 2, implanted aortic ring significantly reduced annulus diameter (20.6+/-1.8 mm) without significant aortic valve gradient (8.3+/-3 mmHg). Follow-up was 17.2+/-13.4 months (group 1) and 10.41+/-7.95 months (group 2). Reoperation for recurrent aortic regurgitation was 13% in group 1 (n=3) versus 4.2% in group 2 (n=2). Echocardiographic follow-up found residual aortic regurgitation < or =grade I in 17 patients in group 1 (90%) versus 43 patients in group 2 (95.5%) and of grade II in two patients in group 1 (10%) and two patients in group 2 (4.5%). CONCLUSION: The addition of external aortic prosthetic ring annuloplasty improves the remodeling technique's operative reproducibility and short-term results. Therefore, its use as a systematical adjunct to the remodeling procedure is suggested. However, further long-term evaluation comparing this valve-sparing procedure to composite graft replacement should define the best surgical strategy for aortic root aneurysm.     

Intermediate-term durability of bicuspid aortic valve repair for prolapsing leaflet.

OBJECTIVE: To determine the durability of repair of a bicuspid aortic valve with leaflet prolapse, and to identify factors associated with repair failure. METHODS: From November 1988 to January 1997, 94 patients with a bicuspid aortic valve and regurgitation from leaflet prolapse had aortic valve repair. In 66 patients, the repair employed triangular resection of the prolapsing leaflet. The remainder underwent mid-leaflet plication of the prolapsing leaflet. Mean age was 38 +/- 10 years and 93% were male. Median follow-up was 5.5 years (range 0.2-9 years). Factors associated with aortic valve competence and durability were identified by multivariable logistic and hazard function analyses. RESULTS: Early valve competence was more difficult to achieve in patients with large, poor functioning ventricles (P = 0.02). Aortic valve reoperation was necessary in 12 patients that included three re-repairs and nine aortic valve replacements. Freedom from reoperation was 95, 87 and 84% at 1, 5 and 7 years, respectively. The instantaneous risk of reoperation was highest immediately after operation, and fell rapidly to approximately 2% per year and less after 2 years. The only risk factor identified was the presence of residual aortic regurgitation (trace to mild in 35 cases) on immediate intraoperative post-repair transesophageal echocardiography. Late aortic regurgitation did not progress detectably across time (P = 0.3). There were no deaths, early or late. CONCLUSION: Bicuspid aortic valve repair for prolapsing leaflet is a safe procedure with good intermediate-term outcome. However, any residual aortic regurgitation jeopardizes repair durability and initial repair achievement is more difficult in patients with dilated, poor functioning ventricles.     

Analysis of valve motion after the reimplantation type of valve-sparing procedure (David I) with a new aortic root conduit

BACKGROUND: The reimplantation type of valve-sparing procedure does not allow proper reconstruction of the sinuses of Valsalva. We assessed the valve motion after a reimplantation type (David I) of valve-sparing procedure using a new Dacron conduit that incorporates sinuses of Valsalva. METHODS: Nine consecutive patients undergoing an aortic valve-sparing procedure using the new conduit were studied using two-dimensional transesophageal echocardiography shortly (2 +/- 1 months) after operation to determine root distensibility, expressed as percent change in radius and as pressure strain of the elastic modulus. Next, monodimensional view was used to assess valve motion in its various phases (rapid valve opening velocity, slow closing leaflet displacement, rapid valve closing velocity, maximal leaflet displacement, and leaflet displacement before valve closure). Seven healthy individuals served as control subjects. RESULTS: Root distensibility was reduced at the level of the annulus and sinotubular junction but was similar to control subjects at the level of the sinuses (percent change in radius, 4.1% +/- 0.8% versus 4.5% +/- 1.2%; pressure strain of the elastic modulus, 1,286 +/- 674 g/cm2 versus 1,195 +/- 628 g/cm2). Rapid valve opening (69 +/- 34.4 cm/s versus 51 +/- 11.9 cm/s) and closing (47.6 +/- 16 cm/s versus 36.4 +/- 9 cm/s) velocity as well as slow closing leaflet displacement (24% +/- 4.7% versus 22.1% +/- 7.9%), maximal leaflet displacement (20.1 +/- 4 mm versus 22.7 +/- 1.9 mm), and leaflet displacement before valve closure (15.2 +/- 3 mm versus 17.6 +/- 0.8 mm) were similar to control subjects. CONCLUSIONS: The new aortic root conduit used in a reimplantation type of valve-sparing procedure allows the anatomic reconstruction of the aortic root with leaflet motion similar to that of normal subjects.     

Aortic valve reconstruction in the young infants and children

Considering the structure and function of the aortic root, changes in the aortic valve leaflets and changes in the geometry of the aortic root are the two primary causes of aortic valve dysfunction. In adults, aortic valve sparing reconstruction has a long history beginning in the 1970s, where tensor fascia was used for leaflet repair in patients with isolated aortic regurgitation and ascending aortic replacement was used in patients with ascending aortic aneurysms or aortic ectasia. Subsequent progress in the 1980s and 1990s led to pericardial leaflet replacement and aortic root re-implantation and remodeling. However, it has not been until the last decade that these concepts and techniques have been applied in younger patients focusing on the conotruncus, valvar apparatus, sino-tubular junction, and ascending aorta.     

Nicks operation for aortic valve dysfunction with pannus formation; report of a case

A 58-year-old female who underwent an aortic valve replacement 3 years ago was admitted to our hospital. She developed dyspnea in a month. Urgent reoperation was scheduled because an echocardiography demonstrated severe aortic valve regurgitation, and because a cinefluoroscopy showed that a leaflet of the prosthetic valve was restricted. Pannus formation from left ventricular outflow tract caused prosthetic valve insufficiency. An ATS 18 aortic prosthesis was replaced after removing old sewing cuff and surrounding tissue of the aortic annulus as much as possible. However, the coronary orifices were partially covered with the prosthesis. The leaflet rubbed onto the left ventricular outflow muscle specially in opening position. Therefore, an annular enlargement was required. In case of re-replacement of prosthetic valve for small aortic annulus, the annulus was at most same size or smaller than it of the previous operation. It was harmful for the patient whose body surface area was 1.74 m2 to utilize smaller prosthesis because of patient-prosthesis mismatch. We conclude that annular enlargement is useful for reoperarion of small aortic annulus associate with left ventricular outflow hypertrophy.     

Morphometric analysis of miniature swine hearts as potential human xenografts

Abstract: Miniature swine are considered to be potential donors for clinical cardiac transplantation. However, it is unclear how an appropriately sized porcine donor will be selected for a particular human recipient. To address this issue, we performed a morphometric study of the swine heart using transthoracic echocardiography (n = 26) to determine the diameters of the aortic annulus and root, pulmonary artery annulus, and mitral valve annulus. We also obtained direct ex vivo measurements of swine heart weight and linear dimensions (n = 71). Relationships between a swine's height, weight, length, chest circumference and these internal and external cardiac dimensions are described. The strongest correlations were found between a pig's body length and its aortic annulus and root diameters (r-values = 0.97). These relationships are accurately described by univariate linear regression models. By cross-relating our morphometric measurements of aortic annulus diameter in the miniature swine with normative human data, we were able to develop a nomogram, relating swine length and human height, which predicts which miniature swine would donate the best size-matched heart for a particular human recipient.     

Methods for graft size selection in aortic valve-sparing operations

Simple and reproducible methods for accurate restoration of aortic root dimensions during aortic valve-sparing operations are described. The methods are based on choice of an appropriate size vascular graft based on the measured or desired diameter of the aortic annulus.     

In vitro investigation of aortic valve annuloplasty using prosthetic ring devices

Objectives: The remodeling of the dilatated valve annulus with a prosthetic ring for the repair of valve insufficiency is a well-established concept in mitral valve surgery, and may also be suitable for aortic valve reconstruction. In this study, two models of prosthetic aortic annuloplasty devices were investigated. Methods: Fresh porcine aortic roots (n = 16) were investigated in a pulsatile flow simulator after patch dilatation of the annulus and subsequent reconstruction using both an external and an internal prosthetic ring. For each configuration, leakage was determined by ultrasonic flow measurements and leaflet co-aptation by transesophageal echocardiography. In addition, valves’ motions were recorded by high-speed video. Results: By the use of the prosthetic annuloplasty rings, leakage volumes decreased significantly compared with the dilatated root, more pronounced with the intra-annular ring. Similarly, the co-aptation height of the leaflets increased. Pressure gradients were not significantly influenced by the ring application, but leaflet motion patterns changed from the usual trapezoid to a more rectangular opening characteristic, visible at both echocardiographic and high-speed video analysis. Conclusions: The reconstruction of a dilatated aortic valve annulus using external and internal ring devices is feasible and effective for reduction of regurgitation at which the internal ring provides a greater potential to decrease valve insufficiency.     

Manouguian法瓣环增宽加主动脉瓣置换术治疗成人小主动脉瓣环

目的总结成人主动脉瓣狭窄伴小主动脉瓣环行瓣环增宽并替换主动脉瓣的经验。方法 12例病人行主动脉瓣环增宽并替换主动脉瓣。手术径路均采用Manouguian法：将主动脉斜切口下延伸,经无冠瓣与左冠瓣交界处向下,垂直切开瓣环至二尖瓣基部。采用绦纶片内衬自体心包片作为增宽材料,替换23 mm或25 mm主动脉瓣;同期行二尖瓣替换4例。结果 1例同期行二尖瓣置换者因严重低心排死于手术当晚;1例术后第7 d因心包填塞经剑突下引流后痊愈;肺部感染并发呼吸功能不全1例,经气管切开及呼吸机支持1周后痊愈;1例主动脉根部明胶海绵物填充后感染于术后12 d再次开胸清除腐烂明胶海绵,并留管冲洗引流而愈。本组术后住院13~20 d,平均（16.2±1.5）d;11例患者均获随访,时间5~84个月,平均（36.7±21.2）个月,心功能恢复至Ⅰ级5例,Ⅱ级6例,无远期死亡。结论对大多数小主动脉瓣环,采用Manouguian术式简单易行,不需切开二尖瓣基部,已能满足替换23 mm或25 mm瓣膜,增宽材料易得,效果可靠。     

Tricuspidisation of the aortic valve with creation of a crown-like annulus is able to restore a normal valve function in bicuspid aortic valves

Objective: To evaluate the early results of a new method to repair malfunctioning bicuspid aortic valves by creating a tricuspid valve with a crown-like (i.e. anatomic) annulus. Material and methods: Twelve patients (ages from 10 to 27 years) with chronic regurgitation (and flow-dependent stenosis) of a bicuspid aortic valve underwent repair with the principle of creating a tricuspid valve and a crown-like annulus. The fused leaflets were trimmed and reinserted underneath the existing aortic annulus to create one new native cusp. The third leaflet was fashioned out of a xenopericard patch and was inserted underneath the existing annulus as well to restore the crown-like anatomy of a normal aortic annulus. A tricuspid aortic valve with a morphologically normal annulus was thus created, which resulted in improved coaptation of the leaflets. The repair was immediately assessed by transesophageal echocardiography (TEE) with the heart loaded at 50%. In two patients, a second run helped fine-tune the repair. Median cross-clamping time was 82 min. Follow-up ranged from 3 to 46 months (median 13 months). Results: No significant complication occurred. The function of the aortic valve was excellent with trivial or mild regurgitation in 11 patients and moderate regurgitation in 1 patient. There was no stenosis across the valve. The repair remained stable over time. Remodelling of the left ventricle occurred as expected. Conclusions: Aortic valve repair is feasible in some dysfunctioning bicuspid aortic valves. Tricuspidisation of the valve can result in excellent systolic and diastolic functions. The creation of a crown-like annulus results in improved coaptation of the cusps and could lead to more reliable outcome. Although long-term results are needed, this anatomic correction seems to be a good alternative to valvular replacement in certain sub-groups of patients.     

Toward standardization of valve-sparing root replacement and annuloplasty

Introduction

The current guidelines for surgical intervention of aortic regurgitation were developed by assuming aortic valve replacement. However, when aortic valve repair is considered, earlier intervention may provide more durable repair. Standardization of the procedures may be required to achieve stable outcomes. The possibility of standardization of valve-sparing root replacement (VSRR) and annuloplasty will be discussed.

Methods and results

The differences between the two VSRRs have decreased with technical modifications, reimplantation using a graft with sinuses, and remodeling with annuloplasty. The minor differences are the maintenance of root distensibility, less root dissection, shorter procedure time, and higher risk of bleeding in the latter. Stable outcomes may be expected by choosing the appropriate graft size according to the root dimensions in the former. In the latter, postoperative commissure height depends on the skill of the surgeon, which can be resolved using a graft with sinuses. There is still controversy regarding the equal arrangement of the commissure heights and angle, but it has been accepted in clinical use provided that postoperative effective heights of each cusp are set equally. External suture annuloplasty maintains the advantages of remodeling because it requires less root dissection and a shorter procedure time. It can accurately predict postoperative annulus diameter. External ring annuloplasty can stabilize the basal ring exactly, but it is time-consuming and postoperative annulus diameter cannot be predicted accurately.

Conclusions

Standardization of VSRR may be feasible, and VSRR is expected to be more widely adopted, which will improve the guidelines.

     

Valve-sparing aortic root re-implantation for commissural detachment with fibrous strand

Both aortic valve commissural detachment and commissural fenestration are rare causes of aortic regurgitation. In general, aortic valve replacement is the mainstay treatment for aortic regurgitation caused by commissural detachment or commissural fenestration. We herein describe valve-sparing aortic root re-implantation and aortic valve repair for aortic regurgitation and aortic root dilatation in an extremely rare case accompanied by both commissural detachment and commissural fibrous strand of fenestrated cusp.     

Successful aortic root remodeling for repair of a dilated pulmonary autograft after a Ross-Konno procedure in early childhood

We report a case of successful reoperation for pulmonary autograft root dilatation causing severe regurgitation after a Ross-Konno procedure in an infant. The procedure consisted of reduction of the circumference of the sinotubular junction and the autograft annulus. This technique is an effective alternative to prolong the transition period after a Ross procedure prior to other definitive surgeries, such as valve-sparing aortic root replacement or prosthetic valve replacement, which are preferably avoided at this young age.     

Results of surgery for aortic root aneurysm in patients with Marfan syndrome

OBJECTIVES: This study was undertaken to examine the long-term results of surgery for aortic root aneurysm in patients with Marfan syndrome. METHODS: Forty-four patients underwent aortic root replacement and 61 underwent aortic valve-sparing operations for aortic root aneurysm. Patients who underwent aortic root replacement had more severe symptoms, worse left ventricular function, more severe aortic insufficiency, and larger aortic root aneurysms than did patients who had aortic valve-sparing operations. Two types of valve-sparing operations were performed: reimplantation of the aortic valve in 39 patients and remodeling of the aortic root in 22 patients. Echocardiography was performed annually during follow-up. The mean follow-ups were 75 +/- 54 months for the aortic root replacement group and 49 +/- 38 months for the aortic valve-sparing group. RESULTS: There were 1 early death and 7 late deaths; 6 deaths were in the aortic root replacement group and 2 were in the aortic valve-sparing group. Survivals at 10 years were 87% in the aortic root replacement group and 96% in the aortic valve-sparing group (P =.3). Freedoms from reoperation at 10 years were 75% in the root replacement group and 100% in the valve-sparing group (P =.1). Freedoms from valve-related mortality and morbidity were 65% after root replacement and 100% after valve-sparing operation (P =.02). Freedom from aortic insufficiency greater than 2+ after aortic valve-sparing operations was 75% at 10 years and was similar for both types of valve-sparing operations; however, the diameters of the aortic annulus and neoaortic sinuses increased only after the remodeling procedure. CONCLUSIONS: This study suggests that aortic valve-sparing operations provide similar survival but lower rates of valve-related complications than aortic root replacement for patients with Marfan syndrome. Reimplantation of the aortic valve may be more appropriate than remodeling of the aortic root to prevent dilation of the aortic annulus, and for this reason we now use only this technique to treat patients with Marfan syndrome.