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.     

Dynamic analysis of the aortic valve using a finite element model

BACKGROUND: The major aim of this study was to examine the leaflet/aortic root interaction during the cardiac cycle, including the stresses developed during the interaction. METHODS: Dynamic finite element analysis was used along with a geometrically accurate model of the aortic valve and the sinuses. Shell elements along with proper contact conditions were also used in the model. Pressure patterns during the cardiac cycle were given as an input, and a linear elastic model was assumed for the material. RESULTS: We found that aortic root dilation starts before the opening of the leaflet and is substantial by the time leaflet opens. Dilation of the root alone helps in opening the leaflet to about 20%. The equivalent stress pattern shows an instantaneous increase in stress at the coaptation surface during closure. Stresses increase as the point of attachment is approached from the free surface. CONCLUSIONS: The complex interplay of the geometry of the valve system can be effectively analyzed using a sophisticated dynamic finite element model. Results not previously brought out by the earlier static analysis shed new light on the root/valve interaction.     

Opening and closing characteristics of the aortic valve after valve-sparing procedures using a new aortic root conduit

BACKGROUND: The durability of aortic valve-sparing procedures is negatively affected by increased leaflet stress in the absence of normally shaped sinuses of Valsalva. We compared valve motion after remodeling procedures using a standard conduit and a specifically designed aortic root conduit. METHODS: Echocardiographic studies of the aortic valve dynamics were performed in 14 patients after remodeling of the aortic root (7 standard conduits, group A; 7 new conduits, group B) and in 7 controls (group C). Opening and closing leaflet velocities and percent of slow closing leaflet displacement were measured. Root distensibility and the pressure strain of the elastic modulus were measured at all root levels. RESULTS: Root distensibility and the pressure strain of the elastic modulus were different in group A and B only at the sinuses (p < 0.001). Opening and closing leaflet velocities were not different among groups. Slow closing leaflet displacement was markedly more evident in group B patients (24.2%+/-1.9% versus 2.5%+/-1.9% in group A, p < 0.001) and similar to controls (22.1%+/-7.9%). CONCLUSIONS: The new conduit guarantees dynamic features of the aortic valve leaflets superior to those obtained with standard conduits and more similar to normal subjects.     

Correction of leaflet prolapse in valve-preserving aortic replacement: pushing the limits?

BACKGROUND: For aortic dilatation with morphologically intact leaflets, valve-preserving aortic replacement has become an accepted treatment modality. Leaflet prolapse, however, may be present, making composite replacement the most frequent choice. Alternatively, valve preservation may be combined with correction of leaflet prolapse. The results of this approach should be comparable with those of valve-preserving aortic surgery in the presence of normal leaflets. METHODS: Between 1995 and 2002, 156 patients were treated by valve-preserving surgery. The aortic valve was bicuspid in 46, and tricuspid in 110 instances. In 88 aortic valves, apparently normal leaflet coaptation (normal, 12 bicuspid and 76 tricuspid), and in 68 instances, prolapse of one or more leaflets, was observed. Root remodeling (n = 133) or aortic replacement with valve reimplantation (n = 23) were performed. Leaflet prolapse was corrected by triangular resection (n = 16) or plicating sutures (n = 59), mostly placed in the central portion of the leaflet. RESULTS: Neither operative mortality nor 5-year survival were influenced by the additional correction of prolapse. Freedom from reoperation at 1 year (normal, 98.8%; prolapse, 96.5%) and 5 years (normal, 97.3%; prolapse, 96.5%) were comparable in both cohorts, as was freedom from aortic regurgitation > or = II at 1 year (normal, 98.8%; prolapse, 94.2%) and 5 years (94.4%). CONCLUSIONS: Surgical correction of leaflet prolapse in combination with proximal aortic replacement is feasible with good results. Midterm results are identical with those known for morphologically normal leaflets. Repair of prolapse allows for preservation of the native valve in most patients with aortic regurgitation and aortic pathology, and thus appears a beneficial addition to valve-preserving surgery.     

The influence of mechanical properties on wall stress and distensibility of the dilated ascending aorta

OBJECTIVES: We sought to determine how intrinsic mechanical properties of dilated ascending aorta influence in vivo distensibility and wall stress, potential contributing factors to the risk of aortic rupture and dissection. METHODS: Fresh tissue from patients undergoing ascending aortic replacement for Marfan syndrome (n = 8, age 38 +/- 14 years), bicuspid aortic valve with associated aneurysm (n = 20, age 55 +/- 12 years), or idiopathic degenerative aneurysm (n = 7, age 64 +/- 9 years) was analyzed for elastic properties and circumferential residual stress. Histologic specimens were graded for elastin fragmentation, cystic changes, fibrosis, and necrosis. Distensibility and wall stresses were predicted with a cylindrical mathematical model of the aorta. RESULTS: Elastic properties of aortic tissue were nonlinear and extensibility decreased with age. Moderate or severe elastin fragmentation was prevalent in tissue from patients with the Marfan syndrome and more common in tissue from younger patients. Model-predicted mean circumferential stress did not vary significantly with age or patient group, but increased with aortic lumen diameter and systolic blood pressure. Model-predicted distensibility decreased with age in bicuspid aortic valve and degenerative aneurysm groups. Differences in distensibility were correlated with differences in elastic properties. CONCLUSIONS: The age dependence of elastic properties of dilated ascending aorta is consistent with that of normal aorta observed in previous studies. Increases in mean circumferential stress with blood pressure and diameter support the clinical importance of blood pressure control and serial evaluation of aortic diameter. Declining wall strength with age may increase the risk of rupture or dissection.     

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.     

Comparison of the in vivo and in vitro mechanical properties of aortic valve leaflets

The mechanical properties of aortic valve leaflets are responsible for the efficiency and longevity of the valve. These properties in the radial direction were investigated in vivo in dogs. During cardiopulmonary bypass, radiopaque markers were placed on the leaflets. Later, from a normally functioning valve, the marker positions were recorded on videotape during fluoroscopy, and the leaflet length was determined. Leaflet length in the radial direction increased 31% from systole to diastole. During diastole, leaflet length increased by 3.9% as the pressure gradient increased from 60 to 200 mm Hg. During systole, the leaflet had a low elastic modulus. In vitro, the stress-strain properties of the leaflets were studied. For an increase in stress in vitro that corresponded to an increase in pressure gradient from 60 to 200 mm Hg, the leaflet length increased 8.7%. This increase was more than twice that measured in vivo, which indicates that during diastole the leaflet is much stiffer in vivo than in vitro. This stiffening appears to be due to stress in the circumferentially oriented collagen fibers of the leaflet, which prevents stretching in the radial direction. In systole, the lower elastic modulus reduces the flexion stresses, and in diastole, stiffening prevents the leaflet from prolapsing under pressure.     

The effect of sizing on the hydrodynamic parameters of the Medtronic freestyle valve in vitro

BACKGROUND: An in vitro model has been established to investigate the effect of sizing on the hydrodynamic characteristics and leaflet motion of the Medtronic Freestyle valve. METHODS: The valves were tested in fresh porcine aortic roots. Two or three different sizes of valves were implanted in the same aortic root one after the other. The compliance of the fresh aortic and the composite roots was measured in the pressure range of 0 to 120 mm Hg, and the composite roots were then tested in a pulsatile flow simulator. The transvalvular gradient and degree of regurgitation were measured and the effective orifice area and performance index were calculated. Leaflet motion was recorded on video. RESULTS: The fresh aortic roots dilated by average 39.4% as the hydrostatic pressure rose from 0 to 120 mm Hg. Implantation of the Medtronic Freestyle valve did not change the distensibility of the aortic root significantly. The sizing protocol did not affect significantly the hydrodynamic performance. However, a significantly lower open leaflet bending deformation was found in the undersized valves. Regurgitation was found only at 2-mm undersized valves. CONCLUSIONS: Leaflet motion of the Medtronic Freestyle valve in vitro was best if 1 mm undersized, and this may be beneficial to long-term durability.     

Aortic valve repair and root preservation by remodeling, reimplantation, and tailoring: technical aspects and early outcome

OBJECTIVES: Evaluate aortic root preserving/sparing procedures for various pathologies associated with ascending aortic aneurysms, including aortic valve regurgitation. METHODS: From the end of 1990 through end of 2004, 388 patients had aortic root preserving procedures (reimplantation 72, remodeling 77, tailoring 239) +/- leaflet repair. Preoperatively, in-house grade aortic regurgitation was 1(+) in 58, 2(+) in 110, 3(+) in 101, and 4(+) in 66. Concurrent leaflet repairs were done in 197 (50.8%, Cabrol/Trusler commissure stitch 158, leaflet plication 36, supracommissure stitch 42, leaflet resection and repair 16, perforation repair 18, and debridement 11). Additional procedures included arch repair in 227 (58%), coronary bypass in 83 (21.4%), elephant trunk in 33 (8.5%), and minimally invasive approach in 30 (7.7%). Pathologies included dissection in 140 (36%; 86 acute), Marfan syndrome in 39 (10%), bicuspid valve in 78 (20%), and degenerative aneurysm in 142 (36.6%). The CLASS (Commissure, Leaflet, Annulus, Sinuses, Sinotubular) evaluation schema is described that is used for selecting either reimplantation, remodeling, or tailoring of the aortic root according to underlying pathology. RESULTS: Hospital survival was 97.4% (378/388) and stroke occurred in 4.6% (18/388, four permanent, [1%]). On postoperative echocardiography, patients had either no (0) or 1(+) regurgitation (1(+)= 98);13 (3.4%) had 2(+). Three patients (1%) required reoperation for aortic valve failure before discharge (two tailoring, one remodeling). CONCLUSIONS: Excellent early results can be achieved by aortic root preserving procedures and concurrent aortic valve leaflet repairs when appropriately selected for a diverse class of pathologies.     

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

OBJECTIVE: To evaluate the results of two operations, aortic valve-sparing and aortic root replacement, in patients with aortic root aneurysm and the Marfan syndrome. METHODS: A retrospective review of 78 consecutive patients with aortic root aneurysm and the Marfan syndrome according to the Gent criteria indicated that 42 patients with normal aortic cusps had an aortic valve-sparing operation, and 36 patients had aortic root replacement (mechanical valve in 25 patients and biological valve in 11). The mean age was similar in both groups, but patients who had aortic root replacement had larger aneurysms, higher grade aortic insufficiency, worse left ventricular function and more cardiac co-morbidity than patients who had aortic valve-sparing operations. The mean follow-up was 41+/-35 months for patients who had aortic valve-sparing, and 65+/-50 months for those who had aortic root replacement. RESULTS: Kaplan-Meyer estimates of survival at 5 years was 100% for patients who had aortic valve-sparing, and 88+/-6% for those who had aortic root replacement (P=0.04). Five patients who had aortic root replacement required seven aortic root re-replacements: three for endocarditis and four for valve failure (biological valves). There have been no reoperations in patients who had aortic valve-sparing operations and annual Doppler echocardiography revealed mild or no aortic insufficiency in 39 patients and moderate aortic insufficiency in three. CONCLUSIONS: These data suggest that aortic valve-sparing operations are safe in patients with the Marfan syndrome and may provide better clinical outcomes than aortic root replacement. Since the size of the aneurysm often determines the feasibility of a valve-sparing procedure, we now recommend surgery when the diameter of the aortic root reaches 50 mm in patients with the Marfan syndrome who have echocardiographically normal aortic valve cusps.     

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.     

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.     

Prophylactic aortic root surgery in patients with Marfan syndrome: 10 years' experience with a protocol based on body surface area.

Background: Current guidelines recommending prophylactic aortic root replacement in Marfan syndrome are based on absolute diameters of the aortic root. However, aortic root diameter is a function of body surface area (BSA). Here, we report our experience with a protocol for prophylactic aortic root replacement based on BSA. Methods: Patients with established Marfan syndrome (Ghent criteria) and without prior aortic surgery were eligible for our study. Aortic root ratio was defined as the ratio between the observed aortic root diameter (as measured during annual echocardiography) and the maximum predicted aortic root diameter as calculated according to age and BSA. Replacement surgery was performed if dilatation of the aortic root during follow-up resulted in an aortic root ratio >/=1.3. Results: Fifty-three patients fulfilled the entry criteria (24men/29 women, median age at baseline 27 years, range 18-59 years). During follow-up between 1997 and 2007 (mean 4.7+/-3.2 years) four patients underwent uncomplicated aortic root replacement; two had an aortic root ratio >/=1.3 (aortic root diameters were 4.9 and 5.2cm, respectively), one had aortic root dilatation of 0.4cm/year and a positive family history for aortic dissection and one had an aneurysm of the ascending aorta as the primary indication. None of the patients in the whole group suffered from type A aortic dissection and there was no mortality. Conclusions: Although numbers are small, our protocol for prophylactic aortic root replacement in patients with Marfan syndrome based on BSA was effective in terms of preventing aortic dissection and mortality.     

Síndrome de Marfan en gestante a término con dilatación de la raíz aórtica entre 40 y 45 mm

Marfan syndrome is a hereditary connective tissue disorder. The main cause of mortality in these patients is due to cardiovascular complications related to dilation of an aneurysm and dissection of the aortic root, a situation that increases their risk due to the physiological changes that occur during pregnancy, childbirth and puerperium. The case is presented of a pregnant woman with Marfan syndrome and aortic root dilatation of 42 mm. The issues are discussed, such as the mode of delivery (vaginal delivery vs. caesarean section) depending on the aortic root diameter or the choice of type of anaesthesia (general vs. neuraxial) in these cases.     

Diagnostic power of aortic elastic properties in young patients with Marfan syndrome

BACKGROUND: In patients with Marfan syndrome, progressive aortic dilation implicates a still-unpredictable risk of life-threatening aortic dissection and rupture. We sought to quantify aortic wall dysfunction noninvasively, determine the diagnostic power of various aortic parameters, and establish a diagnostic model for the early detection of aortic abnormalities associated with Marfan syndrome. METHODS: In 19 patients with Marfan syndrome (age, 17.7 +/- 9.5 years) and 19 age- and sex-matched healthy control subjects, computerized ascending and abdominal aortic wall contour analysis with continuous determination of aortic diameters was performed out of transthoracic M-mode echocardiographic tracings. After simultaneous oscillometric blood pressure measurement, aortic elastic properties were determined automatically. RESULTS: The following ascending aortic elastic parameters showed statistically significant differences between the Marfan group and the control group: (1) decreased aortic distensibility ( P < .001), (2) increased wall stiffness index ( P < .01), (3) decreased systolic diameter increase ( P < .01), and (4) decreased maximum systolic area increase ( P < .001). The diagnostic power of all investigated parameters was tested by single logistic regression models. A multiple logistic regression model including solely aortic parameters yielded a sensitivity of 95% and a specificity of 100%. CONCLUSIONS: In young patients with Marfan syndrome, a computerized image-analyzing technique revealed decreased aortic elastic properties expressed by parameters showing high diagnostic power. A multiple logistic regression model including merely aortic parameters can serve as useful predictor for Marfan syndrome.     

Aortic repair in Marfan's syndrome: prevention of mechanical leaflets damage

Aortic incompetence in Marfan's syndrome results from distortion or dilatation of the sinuses of Valsalva, annuloaortic ectasia or a combination of these problems. Valve leaflets in these patients are macroscopically normal in spite of aortic insufficiency. Replacement of the ascending aorta, root and aortic valve with a composite graft was, for a long time, the treatment of choice for Marfan patients. Valve-preserving procedures (remodeling or reimplantation) provide the advantages of avoiding the shortcomings of standard surgical techniques, and maintaining the functional integrity of the left ventricular (LV) outflow tract, aortic root and ascending aorta. We developed a modified valve-sparing reimplantation technique for avoiding leaflet damage. This was achieved by leaving a 'cushion' of aortic wall (8--10 mm) that, sewn on the Dacron graft, works as a 'damper' and prevents leaflets injury during the systolic opening of the valve. For final judgment of this operative method long-term results are necessary.     

One-staged operation for mitral regurgitation and annuloaortic ectasia without aortic regurgitation with Marfan syndrome; report of a case

A 32-year-old man with Marfan syndrome was admitted to our hospital for detail examination of congestive heart failure. Doppler echocardiography showed severe mitral regurgitation due to prolapse of posterior mitral leaflet. Annuloaortic ectasia without aortic regurgitation was also detected by aortography. Considering the future operative need for aortic root and ascending aorta, we performed mitral valve replacement with a mechanical valve and preventive concomitant aortic root replacement with a composite valve graft. His postoperative course was uneventful. Optimal surgical treatment of mitral regurgitation and annuloaortic ectasia in Marfan syndrome is controversial because the underlying connective tissue defect theoretically might compromise repair durability. Several surgical options for mitral regurgitation and annuloaortic ectasia in Marfan syndrome are discussed.     

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.     

Surgery of the dilated aortic root and ascending aorta in pediatric patients: techniques and results.

OBJECTIVE: Dilatation of the aortic root is a well-known cardiovascular manifestation in children and adult patients with connective tissue disease (e.g. Marfan syndrome). Dilatation of the ascending aorta is extremely rare and may be associated with bicuspid aortic valve. This report evaluates the incidence of dilatative aortic root and ascending aortic pathology in patients younger than 18 years and analyzes the results obtained after repair and replacement strategies. METHODS: Between 1/1995 and 12/2002, a total of 752 operations on the thoracic aorta were performed in adult and pediatric patients. We present our experience with a group of 26 patients <18 years of age, who required isolated surgery of the aortic root and/or ascending aorta because of a dilatative lesion. Fifteen patients had isolated aortic root dilatation (13 of them suffered from Marfan syndrome), eight patients presented with an idiopathic dilatation of the ascending aorta and three patients had dilatation in association with a bicuspid aortic valve. Mean age was 10 +/- 4.8 years (4-18 years). Repair of the aortic root with preservation of the aortic valve (Yacoub, David or selective sinus repair) was performed in nine patients, replacement using a homograft was performed in five patients, composite graft with mechanical prosthesis in two patients, with biological prosthesis in one patient and Ross operation was performed in one case. Isolated supracoronary graft replacement was performed in eight patients. RESULTS: Two patients died during hospitalization: a 10-year old girl developed respiratory failure on the 2nd postoperative day and autopsy revealed Ehlers-Danlos syndrome with a massive intrapulmonary emphysema. A 14-year-old Marfan patient with severely depressed preoperative LV function died from low cardiac output following composite-graft, mitral and tricuspid valve repair. One patient required aortic valve replacement 7 days after an aortic valve sparing root repair. There was no additional perioperative morbidity. In the long-term, two patients died from rupture of the thoracic aorta, both following minor non-cardiovascular surgical procedures. Both had normal sized descending and abdominal aorta. CONCLUSION: Repair of the aortic root and/or ascending aorta in children and adolescent patients can be performed with acceptable early and late results. While the presence of severe comorbidity may adversely affect early outcome, long-term survival was mainly determined by rupture of the descending aorta.     

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.