Quantitative approach to aortic valve-sparing surgery

Our goal was to understand why it is difficult to achieve reliable valve competence after aortic valve-sparing surgery, and to propose quantitative data aimed at improving the outcome of the procedure. Valve-sparing procedures were performed in patients with dilated aortic roots and aortic regurgitation, and reproduced in physical models to explore what should be the restored dimensions of the aortic root and leaflets for valve sparing to be successful. In parallel, a three-dimensional geometric model of the aortic valve was tested to evaluate its capability to predict the annulus diameter, sinotubular junction diameter, valve height, and leaflet free-edge length and height in competent spared valves. Valve sparing resulted in more or less severe residual regurgitation in all the patients considered. Successful valve-sparing was achieved in vitro by making further changes to the annulus diameter, the leaflet free-edge length and/or graft size. The changes needed were effectively predicted by the geometric model. Tabulated valve dimensions allowing restoration of competence were generated for convenient use by surgeons. A quantitative approach to aortic valve sparing is proposed, putting emphasis on the functional characteristics of the restored valve geometry.     

Aortic root remodeling in atheromatous aneurysms: the role of selected sinus repair.

OBJECTIVE: Atheromatous ascending aortic aneurysms (AAA) frequently present with aortic regurgitation (AR) from dilatation of the sino-tubular junction (STJ) and extension of the pathological process into the root. Experience suggests that root dilatation begins in the non-coronary, then right coronary sinus. Rather than employ aortic root replacement or the David procedure, we have elected to replace the ascending aorta and remodel the STJ and involved sinuses. We studied the outcome after selective sinus replacement in 29 consecutive AAA patients between 1995 and 2001. METHODS: There were nine male and 20 females. Age ranged from 47 to 79 years (mean 67.5). Seven had arch aneurysms and four coronary artery disease. Nineteen were NYHA III or IV. Grade of AR was IV in 20, III in five and II in four. The STJ was dilated >50% of annulus diameter in each case (5.3-10.0 cm, mean 6.4 cm). All valves had three cusps. All patients underwent ascending aortic replacement. Seven had arch replacement and four coronary artery bypass. Seven had replacement of both right and non-coronary sinuses with re-implantation of the right coronary ostium. Twelve had replacement of the non-coronary sinus alone whilst nine had right coronary sinus replacement. One with dextrocardia had left coronary sinus replacement with ostial re-implantation. The graft size was within 2 mm of annulus size except for two patients (24 mm 12, 26 mm 11, and 28 mm six). Post operative echocardiographic studies were performed. None of the patients received anticoagulation. RESULTS: There were no hospital or late deaths and no thromboembolic or infective complications. Two patients had mild to moderate aortic regurgitation. These had a size 28 graft, which in retrospect was too large. Others had no significant regurgitation. CONCLUSIONS: The native aortic valve can be preserved in the majority of patients with AAA. Remodelling of the STJ and selective sinus replacement restores valve competence. Anticoagulation and prosthesis related complications are thereby avoided.     

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.     

Mechanisms of aortic valve incompetence: finite-element modeling of Marfan syndrome.

OBJECTIVES: Progressive aortic root dilatation and an increased aortic root elastic modulus have been documented in persons with Marfan syndrome. To examine the effect of aortic root dilatation and increased elastic modulus on leaflet stress, strain, and coaptation, we used a finite-element model. METHODS: The normal model incorporated the geometry, tissue thickness, and anisotropic elastic moduli of normal human roots and valves. Four Marfan models were evaluated, in which the diameter of the aortic root was dilated by 5%, 15%, 30%, and 50%. Aortic root elastic modulus in the 4 Marfan models was doubled. Under diastolic pressure, regional stresses and strains were evaluated, and the percentage of leaflet coaptation was calculated. RESULTS: Root dilatation and stiffening significantly increased regional leaflet stress and strain compared with normal levels. Stress increases ranged from 80% to 360% and strain increases ranged from 60% to 200% in the 50% dilated Marfan model. Leaflet stresses and strains were disproportionately high at the attachment edge and coaptation area. Leaflet coaptation was decreased by approximately 20% in the 50% root dilatation model. CONCLUSIONS: Increasing root dilatation and root elastic modulus to simulate Marfan syndrome significantly increases leaflet stress and strain and reduces coaptation in an otherwise normal aortic valve. These alterations may influence the decision to use valve-sparing aortic root replacement procedures in patients with Marfan syndrome.     

The influence of size mismatch on the hemodynamic performance of the pulmonary autograft in vitro.

OBJECTIVES: We established an in vitro model to investigate the effect of size mismatch between the aortic and pulmonary root on the hydrodynamic performance and leaflet motion of the pulmonary autograft. METHODS: Ten fresh porcine pulmonary roots (annulus diameter: 19-25 mm) were tested in a pulsatile flow simulator. The autografts then were implanted in fresh porcine aortic roots (annulus diameter: 19-30 mm) and retested in the flow simulator. Three roots were oversized by 21-39%, three were undersized by 32-45% and there were four size for size implantations. The external diameter of the roots and autografts was measured at the sinotubular junction at hydrostatic pressures of 0 - 120 mmHg. The transvalvular gradient and regurgitation were also measured and the effective orifice area was calculated. The leaflet motion was recorded on video. RESULTS: The fresh pulmonary roots were more compliant than the fresh aortic roots (46 +/- 8.4% vs. 35 +/- 7.8% dilatation from 0 to 120 mmHg). The group of matching size autografts dilated by 43 +/- 4.9% in the same pressure range. The external diameter of the undersized autografts was 10 +/- 2.1% bigger than before implantation at 0 pressure and then the dilatation was 40 +/- 5.3% at 120 mmHg. The oversized implantation made the autografts 11 +/- 9.4% smaller in their relaxed state, but then they dilated by 65 +/- 11% as the pressure increased to 120 mmHg, resulting in a net dilatation of 54% over the original undilated state. The under or oversizing had little effect on the pressure gradient measured across the valves (5.6 +/- 2.57 mmHg before, 6.3 +/- 3.27 mmHg after implantation). Only the oversized valves showed significantly higher gradients than the native pulmonary valves. The effective orifice area of the undersized autografts was slightly bigger and the oversized autografts was slightly smaller after implantation, although the differences were not significant. The size mismatch did not cause regurgitation on the valves. The video images showed very low-open leaflet-bending deformation, both on the fresh pulmonary and the autograft valves. CONCLUSION: Under or oversizing the pulmonary autograft up to 40% of the annulus diameter did not affect the hydrodynamic parameters significantly. The compliance of the autograft root was able to compensate for the size mismatch without adversely influencing the valve performance.     

Mechanisms of aortic valve incompetence: finite element modeling of aortic root dilatation

Background. Idiopathic root dilatation often results in dysfunction of an otherwise normal aortic valve. To examine the effect of root dilatation on leaflet stress, strain, and coaptation, we utilized a finite element model.

Methods. The normal model incorporated the geometry, tissue thickness, stiffness, and collagen fiber alignment of normal human roots and valves. We evaluated four dilatation models in which diameters of the aortic root were dilated by 5%, 15%, 30%, and 50%. Regional stress and strain were evaluated and leaflet coaptation percent was calculated under diastolic pressure.

Results. Root dilatation significantly increased regional leaflet stress and strain beyond that found in the normal model. Stress increases ranged from 57% to 399% and strain increases ranged from 39% to 189% in the 50% dilatation model. Leaflet stress and strain were disproportionately high at the attachment edge and coaptation area. Leaflet coaptation was decreased by 18% in the 50% root dilatation model.

Conclusions. Idiopathic root dilatation significantly increases leaflet stress and strain and reduces coaptation in an otherwise normal aortic valve. These alterations may affect valve-sparing aortic root replacement procedures.     

Severe mitral regurgitation--relations between magnetic resonance imaging,echocardiography and natriuretic peptides

Objective - The validity of the Ross operation as freestanding root replacement in adult patients with bicuspid aortic valve disease has lately been questioned. We have analyzed retrospectively our results in 23 adult patients (19 males) operated for bicuspid aortic valve disease ad modum "Ross" employing a freestanding root replacement technique. Design - In 9 patients the dominant aortic valve lesion was stenotic (aortic stenosis group) and in the remaining 14 patients it was aortic insufficiency (aortic insufficiency group). The fate of the pulmonary autograft in the two groups was studied. The intraoperatively measured aortic and pulmonary annuli diameters from the two groups were compared with those from a population of normal looking aortic and pulmonary valves matched for body surface area. Results - The aortic insufficiency group needed significant reduction of the aortic annulus diameter to conform to the size of the pulmonary autograft. The pulmonary autograft annuli in this group were significantly larger in diameter than the ones in the aortic stenosis group. The mean pulmonary annulus diameter in the aortic stenosis group was, on the other hand, significantly smaller when compared with that in the normal matched population. After a mean follow-up period of about 19 months, the aortic insufficiency group showed significant dilatation of the neo-aortic sinuses. Between the two groups, the remaining echocardiographic variables remained either stable or improved at follow-up. Conclusion - Pre-existing larger diameters of the aortic and pulmonary annuli in the aortic insufficiency group combined with the significantly increased left ventricular end-diastolic diameters, may predispose these patients to significant dilatation of the unsupported aortic sinuses after a Ross operation. This dilatation does not, however, lead to increase in the autograft valve insufficiency at short-term follow-up if the aortic annulus and the distal ascending aorta are tailored to the size of the pulmonary autograft. Ross operation, employing freestanding aortic root replacement technique, may therefore be recommended in adult patients with bicuspid aortic valve disease with excellent short-term results.     

Anatomical mismatch of the pulmonary autograft in the aortic root may be the cause of early aortic insufficiency after the Ross procedure

Objective: Early aortic insufficiency can be a problem after the Ross procedure. Anatomical mismatch and an inexact surgical technique may lead to distortion of the normal pulmonary valve geometry and subsequent incorrect leaflet coaptation and valve insufficiency. In this study, we assessed the efficacy of changing and improving the surgical technique to minimize the early pulmonary autograft valve failure. The modifications and the strategy are discussed. Methods: From January 1995 to February 1999, a total of 77 adults underwent the Ross procedure for aortic valve replacement at Sahlgrenska University Hospital. The operative technique used was full free-standing aortic root replacement with a pulmonary autograft in all cases. In the first 24 cases, the diameter of the pulmonary roots was seldom measured, eye-balling was used to exclude anatomical mismatch due to a dilated aortic root, and only one attempt of correction was made, which failed. In the other 53 cases, the technique was improved by: (1) reducing the aortic anulus diameter in cases with moderate dilatation; (2) excluding cases with severe dilatation of the aortic annulus; (3) adjusting the diameter of the sinotubular junction of the aorta to the diameter of the sinotubular junction of the pulmonary artery; (4). reimplanting the left ostium in the autograft, and (5) changing the proximal anastomosis technique. Results: In this study, we had an early aortic incompetence of grade 2 in eight patients among the first 24 patients. In the other 53 patients, postoperative echocardiography at 1 week revealed aortic insufficiency of grade 2 in two patients. Conclusions: Aortic insufficiency after the Ross procedure can be minimized by patient selection, intraoperative correction of anatomical mismatch and improved surgical technique.     

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.     

The in vitro hydrodynamic characteristics of the porcine pulmonary valve and root with regard to the ross procedure

OBJECTIVE: The hydrodynamic parameters and leaflet motion of the porcine pulmonary root and valve and the performance of the pulmonary autograft implanted in subcoronary position or as a free-standing root were investigated at systemic and pulmonary pressures in vitro. METHODS: Ten fresh pulmonary and aortic roots (anulus diameter, 20-25 mm) were tested in a pulsatile flow simulator. Five free-sewn pulmonary valves were implanted in aortic roots in the subcoronary position, and 5 pulmonary roots were implanted as free-standing roots. The external diameter of the roots was measured at the sinotubular junction in a pressure range of 0 to 120 mm Hg. The transvalvular gradient and regurgitation were measured, and the effective orifice area was calculated. The leaflet motion was recorded on video tape. RESULTS: The fresh pulmonary roots were more compliant than their aortic counterparts (33% +/- 3. 0% vs 7% +/- 1.5% with dilatation at 0-30 mm Hg and 46% +/- 8.4% vs 35% +/- 7.8% with dilatation at 0-120 mm Hg). The pulmonary roots had a lower pressure drop at systemic than at pulmonary pressures. The pressure drops of the pulmonary roots were also lower than those of the aortic roots in the systemic pressure range. The leaflet opening of the pulmonary valve was triangular, with low bending deformation at all pressures. Implanting the free-sewn pulmonary valve in the subcoronary position or the pulmonary root as a free-standing root did not affect the hydrodynamic parameters and leaflet motion adversely. CONCLUSION: The pulmonary valve and root could easily withstand aortic pressures in vitro. A biphasic dilatation curve ensures that higher pressures did not overdilate the pulmonary root. Moreover, valve performance was better at systemic pressures.     

主动脉根部外科解剖及其与毗邻结构关系

目的：测量主动脉根部不同高度的口径大小，并观察主动脉窦与邻近结构的关系。方法：用30例正常成人甲醛固定心脏标本，测量主动脉根部不同高度的口径和主动脉瓣的大小，观察主动脉窦与邻近结构的关系。结果：（1）主动脉窦中部（Sinus)＞主动脉窦管结合部上1cm(STJ1)＞主动脉窦管结合处（STJ0）＞主动脉瓣环基底（Base）。经方差分析检验，P＜0．05，说明主动脉根部4个高度口径大小的差别具统计学意义。（2）主动脉瓣的瓣高、瓣附着缘长和瓣游离缘长的测量结果显示。（3）二尖瓣前瓣中轴线与主动脉窦的关系显示，二尖瓣前瓣中轴线86．6％位于左冠状动脉窦与无冠状动脉窦之间。（4）右心房主动脉隆凸与主动脉窦的关系显示，右心房主动脉隆凸由无冠状动脉窦形成者占73．3％，由无冠状动脉窦和右冠状动脉窦共同形成者占26．7％。（5）左、右肺动脉瓣交界点与主动脉窦的关系显示，左、右肺动脉瓣交界点对向左、右冠状动脉窦之间者占80％。结论：测量结果有助于心外科手术的开展。     

The myth of the aortic annulus: the anatomy of the subaortic outflow tract

Surgical repair of the small aortic root is limited in part by the very structure of the outflow tract from the left ventricle. The root is not constructed on the basis of a ringlike annulus supporting the leaflets of the aortic valve. The only truly circular structure within the outflow tract is the junction of the aortic wall with the underlying ventricular structures, themselves partly muscular and partly fibrous. This circular ventriculoarterial junction is crossed by the semilunar attachments of the leaflets of the aortic valve, producing an interlinking arrangement between the expanded aortic sinuses and three triangles of fibrous tissue placed beneath the apexes of the commissures between the valve leaflets. The triangles form extensions of the left ventricle that are related, in part, to the pericardial cavity surrounding the heart. The arrangements of the attachment of the leaflets in malformed valves with two (or only one) effective leaflets are highly abnormal, although these valves are usually produced on the template of three aortic sinuses. The valve with two leaflets rarely gives problems during childhood. In valves producing "critical stenosis", there is usually only one effective leaflet, a condition due to incomplete liberation of two of the anticipated three commissures. Detailed study shows that, in these malformed hearts, the attachment of the leaflets is much more annular than in normal valves, with inadequate formation of the fibrous triangles.     

Reduction of the sinotubular junction in patients undergoing ascending aortic replacement with coexisting aortic insufficiency

Abstract Background and Aim of the Study: Dilatation of the STJ may cause consequent aortic insufficiency (AI) in patients with normal aortic valve, in patients with ascending aortic aneurysm. In this study, we analyzed the results of ascending aorta replacement with STJ diameter reduction to correct consequent AI in patients with ascending aortic aneurysm. Methods: Forty‐five consecutive patients who had ascending aortic aneurysm underwent replacement of ascending aorta with reduction of the STJ diameter to correct AI. Mean age of the patients was 61.3 ± 5.2. Twenty‐six (57.8%) were female. Six patients had arch aneurysm. Postoperative echocardiographic studies were performed at discharge and annually thereafter. The mean duration of follow‐up was 4.6 ± 2.9 years. Results: Hospital mortality rate was 4.9% (n = 2). Three patients died during follow‐up. Three patients had late recurrence of AI that was caused by aortic root dilatation. One of these patients required aortic valve replacement because of severe aortic insufficiency. The five‐year survival and survival free from aortic insufficiency were 91.4%± 5.0% and 91.2%± 5.1%, respectively. Conclusions: Reduction of the diameter of STJ can be used to treat AI in patients with ascending aortic aneurysm with nearly normal aortic cusps. Midterm results of this procedure are encouraging. (J Card Surg 2011;26:88‐91)     

Effect of cryopreservation techniques on aortic valve glycosaminoglycans

This study was designed to evaluate the effect of cryopreservation on the glycosaminoglycan (GAG) content of the aortic allografts. Twenty-one porcine aortic valves were obtained. Five aortic roots were immediately analyzed without cryopreservation, eight were cryopreserved in closed leaflet position, and eight in open leaflet position. The groups were compared in terms of GAG concentration and subclass proportion in three different zones including the aortic root wall, the commissures, and the leaflets. GAG content at the commissures was significantly lower in the closed leaflet group than in the other groups (P = 0.001). The electrophoretic analysis did not show any significant difference in the zonal distribution of GAG classes between groups. Quantitative analysis in various aortic valve zones suggests that cryopreservation can alter the GAG content. Cryopreservation of the aortic valve in an open leaflet position can preserve the matrix more efficiently and might prolong the durability of the aortic allograft.     

Sorin Solo stentless valve: extended adaptability for sinotubular junction mismatch

Stentless valve continence is affected by the implantation technique, annular symmetry and dilatation of the sinotubular junction. We tested in vitro how the Sorin Solo stentless pericardial valve adapts to a slightly dilated sinotubular junction. Stentless Sorin Solo aortic valves (25 mm) were sutured into a 32-mm Valsalva graft suspending the commissures into the expandable region of the graft. The neo-aortic root was pressurized and sinotubular junction size progressively decreased by wrapping the neocommissural ridge with Dacron rings. Direct endoscopic view and ultrasound imaging were used to observe geometry and morphology of leaflets, regurgitation, height and level of leaflets coaptation. Fresh porcine valves of the same annular size were used as controls. Solo valves had mild regurgitation at baseline, became continent at 32 mm sinotubular junction size and remained continent at any size of reduction, with optimal coaptation height and level. Porcine valves had severe regurgitation at baseline, became continent at 30 mm and showed mild insufficiency and reduction of the coaptation level at a sinotubular junction of 28 mm. The Solo valve prevents residual valve regurgitation for a wider range of sinotubular junction mismatch when compared with natural porcine valves. This extended tolerance to sinotubular junction mismatch suggests a safe use of stentless valves even in suboptimal geometry roots.     

Aortic Valve Replacement with Stentless Porcine Bioprostheses

The implantation of stentless porcine valves (SPVs) is technically more demanding than implantation of stented bioprosthetic valves. Implantation of the Toronto SPV bioprosthesis requires an,understanding of the relationships between the leaflets and the aortic annulus and sinotubular junction. In addition to proper alignment of the three commissures within the aortic root, the diameter of sinotubular junction should not exceed the external diameter of the porcine aortic valve after completion of the operation. The Medtronic Freestyle porcine aortic root bioprosthesis can be used for subcoronary implantation as well as for aortic root replacement. Degenerative calcification of a tricuspid aortic valve is the most common cause of aortic valve disease in older patients. Implantation of stentless valves in the subcoronary position is usually feasible because the geometry of the aortic root is well maintained in these patients. The bicuspid aortic valve is the second most common cause of aortic valve disease in older patients and the most common in younger patients. These patients frequently have dilated aortic root, and the Medtronic Freestyle bioprosthesis is ideal for implantation using the root inclusion technique. Stentless porcine bioprostheses are minimally obstructive and associated with low mean systolic gradients. In addition, they have better hemodynamic performance during exercise than stented bioprostheses. For these reasons, patient-prosthesis mismatch has not been described with stentless valves. Left ventricular function after aortic valve replacement appears to be better with stentless than with stented bioprostheses. Comparative, nonrandomized studies of aortic valve replacement with stented and stentless valves suggest that the risk of cardiac death is reduced with stentless valves and the rates of valve-related complications also appear to be lower. What remains unknown is whether stentless valves are more durable than stented ones.     

Allograft aortic valve implantation: techniques for all types of aortic valve and root pathology

The geometry and degree of symmetry of the diseased aortic root and valve dictate the technical method of implantation of the allograft aortic valve. Five methods are available that are suitable for the full range of aortic root disease: the small aortic root with a valve annulus diameter less than 21 mm, the common aortic valve lesions (valve annulus diameter, 21 to 29 mm), the aneurysmal noncoronary sinus, the moderately large annulus (valve annulus diameter greater than 30 mm), and the aneurysmal aortic root and dilated annulus. Implantation methods include the subcoronary technique, miniroot inclusion technique, and aortic root replacement. Technical variations such as valve inversion during implantation, valve rotation, and continuous or interrupted suture methods are important in certain techniques. The allograft aortic valve is a versatile device that can be used in the surgical management of the full range of aortic valve and aortic root pathology.     

Further insights into normal aortic valve function: role of a compliant aortic root on leaflet opening and valve orifice area

BACKGROUND: This study aims to find the fundamental differences in the mechanism of opening and closing of a normal aortic valve and a valve with a stiff root, using a dynamic finite element model. METHODS: A dynamic, finite element model with time varying pressure was used in this study. Shell elements with linear elastic properties for the leaflet and root were used. Two different cases were analyzed: (1) normal leaflets inside a compliant root, and (2) normal leaflets inside a stiff root. RESULTS: A compliant aortic root contributes substantially to the smooth and symmetrical leaflet opening with minimal gradients. In contrast, the leaflet opening inside a stiff root is delayed, asymmetric, and wrinkled. However, this wrinkling is not associated with increased leaflet stresses. In compliant roots, the effective valve orifice area can substantially increase because of increased root pressure and transvalvular gradients. In stiff roots this effect is strikingly absent. CONCLUSIONS: A compliant aortic root contributes substantially to smooth and symmetrical leaflet opening with minimal gradients. The compliance also contributes much to the ability of the normal aortic valve to increase its effective valve orifice in response to physiologic demands of exercise. This effect is strikingly absent in stiff roots.     

Novel technique of aortic valvuloplasty.

OBJECTIVE: The present study was aimed to assess the results of newly developed aortic valve repair technique. METHODS: Between 1997 and 2004, 69 aortic valvuloplasties were performed with a new technique addressing the three main components of the aortic root; leaflets (L), sinotubular junction (STJ), and aortic annulus (A). For leaflet correction, additional leaflets were implanted and for STJ and annular reduction, an internal synthetic ring and strip along the fibrous annulus were implanted, respectively. The patients were divided into two groups: 30 patients with isolated aortic regurgitation (group IAR) were treated by correction of STJ+L (n=21) and STJ+A+L (n=9), and 39 aortic regurgitation patients with annuloaortic ectasia or ascending aortic aneurysm (group AAR) were treated with STJ correction only (n=16), STJ+A (n=6), STJ+L (n=9), and STJ+A+L (n=8). RESULTS: The mean age was 43.4 and 49.5 years for groups IAR and AAR, respectively. There was neither operative nor follow-up death in either group. Suture breakage caused one reoperation in group IAR. Mean follow-up was 13.8 and 20.3 months in groups IAR and AAR, respectively. The preoperative aortic regurgitation grade was 3.67 in group IAR and 2.67 in group AAR. The last follow-up aortic regurgitation grade was 1.1 in group IAR and 1.05 in group AAR. No patient, except for the reoperated patient had AR greater than grade 2. The postoperative pressure gradient was 19.3 mmHg in group IAR and 8. 4mmHg in group AAR. CONCLUSIONS: The results showed this technique to be safe and effective. Thus far broad application of this repair technique has been demonstrated to be highly feasible.     

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.