Long-term outcomes and cost effectiveness of high-dose dexamethasone for cardiac surgery: a randomised trial.

Prophylactic intra-operative administration of dexamethasone may improve short-term clinical outcomes in cardiac surgical patients. The purpose of this study was to evaluate long-term clinical outcomes and cost effectiveness of dexamethasone versus placebo. Patients included in the multicentre, randomised, double-blind, placebo-controlled DExamethasone for Cardiac Surgery (DECS) trial were followed up for 12 months after their cardiac surgical procedure. In the DECS trial, patients received a single intra-operative dose of dexamethasone 1 mg.kg-1 (n = 2239) or placebo (n = 2255). The effects on the incidence of major postoperative events were evaluated. Also, overall costs for the 12-month postoperative period, and cost effectiveness, were compared between groups. Of 4494 randomised patients, 4457 patients (99%) were followed up until 12 months after surgery. There was no difference in the incidence of major postoperative events, the relative risk (95%CI) being 0.86 (0.72-1.03); p = 0.1. Treatment with dexamethasone reduced costs per patient by £921 [€1084] (95%CI £-1672 to -137; p = 0.02), mainly through reduction of postoperative respiratory failure and duration of postoperative hospital stay. The probability of dexamethasone being cost effective compared with placebo was 97% at a threshold value of £17,000 [€20,000] per quality-adjusted life year. We conclude that intra-operative high-dose dexamethasone did not have an effect on major adverse events at 12 months after cardiac surgery, but was associated with a reduction in costs. Routine dexamethasone administration is expected to be cost effective at commonly accepted threshold levels for cost effectiveness.

The role of exercise echocardiography in the management of mitral valve disease.

PURPOSE: Exercise echocardiography can assess the dynamic component of mitral valve (MV) disease and may therefore be helpful for the clinical decision-making by the heart team. The purpose of this study is to determine the role of exercise echocardiography in the management of disproportionately symptomatic or otherwise atypical patients with mitral regurgitation (MR) and stenosis (MS) in clinical practice. METHODS: Data of 14 MR and 14 MS patients, including echocardiograms at rest, were presented retrospectively to an experienced heart team to determine treatment strategy. Subsequently, exercise echo data were provided whereupon once again the treatment strategy was determined. This resulted in: value of exercise echo by means of 1) alteration or 2) confirmation of treatment strategy or 3) no additional value. RESULTS: During exercise the echocardiographic severity of MV disease increased in 9 (64 %) MR and 8 (57 %) MS patients. Based upon alteration or confirmation of the treatment strategy, the value of exercise echocardiography in the management of MR and MS was 86 % and 57 %, respectively. CONCLUSION: This study showed that physical exercise echo can have an important role in the clinical decision-making of challenging patients with MV disease. Exercise echocardiography had additional value to the treatment strategy in 71 % of these patients.

Bicuspid stenotic aortic valves: clinical characteristics and morphological assessment using MRI and echocardiography.

BACKGROUND: Bicuspid aortic valve (BAV) is one of the most common congenital heart defects with a population prevalence of 0.5% to 1.3%. Identifying patients with BAV is clinically relevant because BAV is associated with aortic stenosis, endocarditis and ascending aorta pathology. METHODS AND RESULTS: Patients with severe aortic stenosis necessitating aortic valve replacement surgery were included in this study. All dissected aortic valves were stored in the biobank of the University Medical Centre Utrecht. Additionally to the morphological assessment of the aortic valve by the surgeon and pathologist, echocardiographic and magnetic resonance imaging (MRI) images were evaluated. A total of 80 patients were included of whom 32 (40%) were diagnosed with BAV by the surgeon (gold standard). Patients with BAV were significantly younger (55 vs 71 years) and were more frequently male. Notably, a significant difference was found between the surgeon and pathologist in determining valve morphology. MRI was performed in 33% of patients. MRI could assess valve morphology in 96% vs 73% with echocardiography. The sensitivity of MRI for BAV in a population of patients with severe aortic stenosis was higher than echocardiography (75% vs 55%), whereas specificity was better with the latter (91% vs 79%). Typically, the ascending aorta was larger in patients with BAV. CONCLUSION: Among unselected patients with severe aortic valve stenosis, a high percentage of patients with BAV were found. Imaging and assessment of the aortic valve morphology when stenotic is challenging.

Infection after ICD implantation: operating room versus cardiac catheterisation laboratory.

BACKGROUND/OBJECTIVES: Since the insertion of an implantable cardioverter-defibrillator (ICD) has become technically comparable to pacemaker implantation, these procedures are increasingly being performed in a cardiac catheterisation laboratory (CCL) instead of the operating room (OR). This study aims to describe the relationship between incidence of ICD infection and procedure setting and to describe the characteristics of ICD infection. METHODS: A retrospective study was performed of first ICD implantation in 677 patients admitted to our hospital between 1996 and 2006. Implantations were performed in the OR until 2003, after 2003 they were carried out in the CCL. The follow-up was censored at one year after implantation. ICD infections were defined as pocket infection or ICD-related endocarditis and a descriptive analysis was performed. RESULTS: Cardiothoracic surgeons implanted 366 ICDs in the OR Electrophysiologists performed 301 implantations in the CCL. Pulse generators were inserted using a pectoral approach with transvenous lead systems. We identified seven ICD infections (incidence rate 1.2/100 person-years), three of which had been implanted in the OR and four in the CCL. CONCLUSION: In this single-centre study no difference in the incidence of ICD infection was observed between implantation in OR and CCL. However, a larger study will be necessary to rule out a relationship with certainty. (Neth Heart J 2009;17:95-100.).

Recommended transoesophageal echocardiographic evaluation of mitral valve regurgitation.

Valve replacement in patients with mitral valve regurgitation is indicated when symptoms occur or left ventricular function becomes impaired. Using different surgical techniques, mitral valve reconstruction has lead to earlier interventions with good clinical results. In order to determine the possibility of a mitral valve reconstruction, echocardiographic parameters are necessary. With transoesophageal echocardiography a segmental analysis of the entire mitral valve can be performed; mitral valve motion abnormalities and severity and direction of the regurgitation jet can be judged. From this analysis clues for underlying pathology can be derived as well as the eligibility of a successful mitral valve reconstruction. This article focuses on transoesophageal examination with segmental analysis in patients with mitral valve regurgitation.

A patient with four artificial heart valves after ergotamine therapy.

A 67-year-old female was evaluated in the out-patient clinic because of shortness of breath on exertion and regular spells of fever. She had been taking ergotamine tartrate to treat migraine for more than 30 years. The patient had undergone aortic-valve replacement for aortic insufficiency three years before. On echocardiographic evaluation, severe retraction and insufficiency of the remaining native heart valves was demonstrated. Endocarditis and carcinoid syndrome were excluded. The mitral, tricuspid and pulmonary valves were all replaced by a mechanical valvular prosthesis. Pathological-anatomical evaluation of the three replaced valves and the aortic valve replaced three years earlier disclosed identical findings, compatible with long-term ergotamine use. Nine months after surgery, a sick sinus syndrome developed necessitating implantation of a DDDR pacemaker with a right atrial and a coronary sinus lead. Functional class according to the New York Heart Association improved from class III to I. After stopping the ergotamine, the fever disappeared. However, the migraine spells reoccurred which are now being treated with paracetamol.

Heart transplantation in the Netherlands: quo vadis?

Heart transplantation is limited by the lack of donor organs. Twenty years after the start of the Dutch transplant programmes in Rotterdam and Utrecht the situation has even worsened, despite efforts to increase the donor pool. The Dutch situation seems to be worse than in other surrounding countries, and several factors that may influence donor organ availability and organ utilisation are discussed. The indications and contraindications for heart transplantation are presented, which are rather restrictive in order to select optimal recipients for the scarce donor hearts. Detailed data on donor hearts, rejected for transplantation, are shown to give some insight into the difficult process of dealing with marginal donor organs. It is concluded that with the current low numbers of acceptable quality donor hearts, there is no lack of capacity in the two transplanting centres nor is the waiting list limiting the number of transplants. The influence of our current legal system on organ donation, which requires (prior) permission from donor and relatives, is probably limited. The most important determinants of donor organ availability are: 1. The potential donor pool, consisting of brain dead victims of (traffic) accidents and CVAs and 2. Lack of consent to a request for donation. The potential donor pool is remarkably small in the Netherlands, due to relatively low numbers of (traffic) accidents, with an almost equal number of CVA-related brain dead patients compared with neighbouring countries. Lack of consent can only be pushed back by improved public awareness of the importance of donation and improved skills of professionals in asking permission in case there is no previous consent.

Human tissue valves in aortic position: determinants of reoperation and valve regurgitation.

BACKGROUND: Human tissue valves for aortic valve replacement have a limited durability that is influenced by interrelated determinants. Hierarchical linear modeling was used to analyze the relation between these determinants of durability and valve regurgitation measured by serial echocardiography. METHODS AND RESULTS: In adult patients, 218 cryopreserved aortic allografts were implanted with the subcoronary (85) or the root replacement technique (133), and 81 patients had root replacement with a pulmonary autograft. Mean follow-up was 4.2 years (SD 2.7; range, 0 to 10.5). Patient age, operator experience with subcoronary implantation, and allograft diameter were independent predictors for reoperation. With repeated color Doppler echocardiography, the severity of aortic regurgitation was assessed by the jet length method and the jet diameter ratio. Multilevel hierarchical linear modeling was used to estimate initial aortic regurgitation (intercept), its change over time (slope), and the effect of 11 potential determinants of durability on aortic regurgitation. With the jet length method, the intercept was 0.94 grade and the slope was 0.11 grade per year. With the jet diameter ratio, the intercept was 0.34 and the annual increase was 0.01. Subcoronary implanted valves had more initial aortic regurgitation, but progression of aortic valve regurgitation did not differ from root replacement. At midterm follow-up, recipient age <40 years was the only independent predictor of aortic regurgitation. CONCLUSIONS: Subcoronary implantation has a learning curve, resulting in more initial aortic regurgitation and early reoperation compared with root replacement. In both techniques, progression of aortic regurgitation over time is small but accelerated in young adults.

Prognosis after aortic valve replacement with a bioprosthesis: predictions based on meta-analysis and microsimulation.

BACKGROUND: Bioprostheses are widely used as an aortic valve substitute, but knowledge about prognosis is still incomplete. The purpose of this study was to provide insight into the age-related life expectancy and actual risks of reoperation and valve-related events of patients after aortic valve replacement with a porcine bioprosthesis. METHODS AND RESULTS: We conducted a meta-analysis of 9 selected reports on stented porcine bioprostheses, including 5837 patients with a total follow-up of 31 874 patient-years. The annual rates of valve thrombosis, thromboembolism, hemorrhage, and nonstructural dysfunction were 0.03%, 0.87%, 0.38%, and 0.38%, respectively. The annual rate of endocarditis was estimated at 0.68% for >6 months of implantation and was 5 times as high during the first 6 months. Structural valve deterioration was described with a Weibull model that incorporated lower risks for older patients. These estimates were used to parameterize, calibrate, and validate a mathematical microsimulation model. The model was used to predict life expectancy and actual risks of reoperation and valve-related events after implantation for patients of different ages. For a 65-year-old male, these figures were 11.3 years, 28%, and 47%, respectively. CONCLUSIONS: The combination of meta-analysis with microsimulation enabled a detailed insight into the prognosis after aortic valve replacement with a bioprosthesis for patients of different ages. This information will be useful for patient counseling and clinical decision making. It also could serve as a baseline for the evaluation of newer valve types.

Intraoperative two-dimensional echocardiography in congenital heart disease.

Intraoperative epicardial two-dimensional echocardiography was used in 195 patients undergoing surgery for congenital heart disease to evaluate its potential to identify new diagnostic information immediately before and after surgical correction. In 168 patients the preoperative diagnosis was confirmed by intraoperative echocardiography. In four patients, unsuspected findings were revealed, which resulted in modification of the surgical approach. In 18 patients additional morphologic information was obtained which contributed to alteration or refinement of surgical management. The adequacy of cardiac repair was assessed before closure of the chest in all patients. In six patients this information led to immediate reoperation and in four other patients to inotropic drug therapy. During congenital heart surgery, epicardial two-dimensional echocardiography may yield important information for surgical management. The technique is an essential adjunct when preoperative diagnostic studies are not conclusive or when the initial response to repair is unsatisfactory.

Transesophageal Doppler color flow imaging in the detection of native and Björk-Shiley mitral valve regurgitation.

Regurgitant blood flow of mitral valves was studied by transesophageal Doppler color flow echocardiographic imaging in 11 healthy volunteers (Group 1), 25 cardiac patients with a native mitral valve (Group 2), 10 patients with a normally functioning Björk-Shiley mitral prosthesis without clinical evidence of mitral regurgitation (Group 3) and 10 patients with angiographic or surgical evidence of Björk-Shiley mitral valve regurgitation (Group 4). Holosystolic regurgitant color jets were classified as type I or type II. The data were compared with results obtained with precordial techniques, i.e., continuous wave and Doppler color flow echocardiographic imaging (Groups 1 to 4) and left ventricular angiography or surgery (Groups 2 and 4). In Group 1, transesophageal Doppler color flow imaging revealed no mitral regurgitant flow in 7 of the 11 patients and a type I jet in 4 patients that was detected in only 1 patient by precordial techniques. In Group 2, angiography showed no mitral regurgitation in 20 patients and documented mitral regurgitation in 5. Transesophageal Doppler color flow imaging detected in 4 of the 20 patients a type I jet that was not visualized with precordial techniques in 2 patients. Type II jets were detected by the transesophageal technique in all five patients with proven mitral regurgitation and were also visualized with precordial echocardiography. All patients in Group 3 showed two identical type I jets that were not detected with precordial echocardiography.(ABSTRACT TRUNCATED AT 250 WORDS)

Smoking cessation reduces mortality after coronary artery bypass surgery: a 20-year follow-up study.

OBJECTIVES: The goal of this study was to determine the influence of smoking cessation on mortality after coronary artery bypass graft surgery (CABG), which has still not been established clearly. BACKGROUND: Cigarette smoking is one of the known major risk factors of coronary artery disease. METHODS: One thousand and forty-one patients underwent CABG between 1971 and 1980. The preoperative and postoperative smoking habits of 985 patients (95%) could be retrieved and were analyzed in a multivariate Cox analysis. RESULTS: The median follow-up was 20 years (range 13 to 26 years). Smoking status before surgery did not entail an increased risk of mortality: patients who had smoked before surgery and those who had not smoked in the year before surgery had a similar probability of survival. However, smoking cessation after surgery was an important independent predictor of a lower risk of death and coronary reintervention during the 20-year follow-up when compared with patients who continued smoking. In analyses adjusted for baseline characteristics, the persistent smokers had a greater relative risk (RR) of death from all causes (RR 1.68 [95% confidence interval 1.33 to 2.13]) and cardiac death (RR 1.75 [1.30 to 2.37]) as compared with patients who stopped smoking for at least one year after surgery. The estimated benefit of survival for the quitters increased from 3% at five years to 14% at 15 years. The quitters were less likely to undergo repeat CABG or a percutaneous coronary angioplasty procedure (RR 1.41 [1.02 to 1.94]). CONCLUSIONS: Patients who continued to smoke after CABG had a greater risk of death than patients who stopped smoking. They also underwent repeat revascularization procedures more frequently. Cessation of smoking is therefore strongly recommended after CABG. Clinicians are encouraged to start or to continue smoking-cessation programs in order to help smokers to quit smoking, especially after CABG.

Assessment of ventricular septal defect closure by intraoperative epicardial ultrasound.

Intraoperative epicardial two-dimensional echocardiographic imaging, color flow mapping and contrast echocardiography were used in 31 patients after patch closure of a ventricular septal defect to determine their respective values in the assessment of residual shunting after cardiopulmonary bypass and for the prediction of long-term results. Epicardial imaging showed no incidence of patch dehiscence. Residual shunting detected by color flow mapping or contrast echocardiography was graded into one of four categories (0 to III). Real time analysis of color flow mapping studies suggested no shunting (grade 0) in 2 patients, grade I shunting in 20, grade II in 8 and grade III in 1; contrast studies suggested grade 0 in 15, grade I in 6, grade II in 8 and grade III in 2. Interobserver variation in real time encoding of grade I or II shunting was 25% by color flow mapping and 6% by contrast echocardiography. Subsequent frame by frame analysis revealed that both diastolic and early systolic right ventricular turbulence gave rise to false positive results during real time analysis of color flow mapping studies. Color flow mapping allowed exact localization of residual shunting, whereas contrast echocardiography allowed better semiquantification. Postbypass results were correlated in 30 patients with late postoperative precordial studies (mean interval 7.5 months). Persistent shunts were found in 6 (20%) of 30 patients. No patient required reoperation for residual shunting. The predictive value of immediate grade I or II shunting as a marker for persistent long-term shunting was poor, whereas both patients with immediate grade III shunting had shunt persistence, indicating that immediate revision should be considered in such patients. Intraoperative epicardial ultrasound is valuable for the immediate exclusion of important residual shunting after ventricular septal defect closure. Maximal information is obtained when color flow mapping and contrast echocardiography are used in combination.

Transesophageal two-dimensional echocardiography: its role in solving clinical problems.

The diagnostic value of transesophageal two-dimensional echocardiography is described in 32 patients in whom precordial echocardiography or angiography, or both, failed to establish a definitive diagnosis. All attempted transesophageal studies were completed without complication and the referral question was definitively answered. Nineteen patients were subsequently submitted to surgery. In 18 of them, the transesophageal echocardiographic diagnoses were proven correct; in 1 patient, the diagnosis was proven partially incorrect. In the 13 unoperated patients the transesophageal echocardiographic diagnoses were not independently confirmed but were assumed correct because incontrovertible images were obtained. These results indicate that transesophageal echocardiography significantly extends the diagnostic capabilities of echocardiography.

Initial results of combined anterior mitral leaflet extension and myectomy in patients with obstructive hypertrophic cardiomyopathy.

OBJECTIVES: The purpose of this study was to describe the clinical and functional results of combined anterior mitral leaflet extension and myectomy in patients with hypertrophic obstructive cardiomyopathy. BACKGROUND: Septal myectomy is the most commonly performed surgical procedure in patients with hypertrophic cardiomyopathy and left ventricular outflow tract obstruction. Because of the role of the mitral valve in creating the outflow tract gradient, mitral valve replacement or plication is performed in selected cases in combination with myectomy, often with better hemodynamic results than those of myectomy alone. Mitral valve leaflet extension, in which a glutaraldehyde-preserved autologous pericardial patch is used to enlarge the mitral valve along its horizontal axis, is a novel surgical approach in patients with hypertrophic obstructive cardiomyopathy. METHODS: Eight patients with hypertrophic obstructive cardiomyopathy were treated with mitral leaflet extension and myectomy. Preoperative and postoperative data (New York Heart Association functional class, number of drugs prescribed, width of the interventricular septum, severity of mitral valve regurgitation severity of systolic anterior motion of the mitral valve and outflow tract gradient) were compared with those of 12 patients undergoing myectomy alone. RESULTS: Preoperative evaluation demonstrated that mitral regurgitation and systolic anterior motion of the mitral valve were more severe in the group undergoing mitral valve extension (p < 0.001 and p < 0.05, respectively). There were no deaths associated with either surgical procedure. Two patients, both treated by myectomy alone, died during the follow-up period. Postoperatively, patients treated with mitral valve extension had less mitral regurgitation (p < 0.005), less residual systolic anterior motion (p < 0.001), greater improvement in functional class (p = 0.05) and greater reduction in the number of drugs (p < 0.005) and in septal thickness (p < 0.05). CONCLUSIONS: Mitral leaflet extension in combination with myectomy is a promising new surgical approach that may provide superior results to those of myectomy alone. Further studies are needed to determine the clinical value of this procedure.

Usefulness of three-dimensional transesophageal echocardiographic imaging for evaluating narrowing in the coronary arteries.

Coronary artery (CA) imaging has relied on invasive techniques for diagnosing stenotic lesions. Two-dimensional techniques are limited in obtaining optimal longitudinal views of all segments of the CA because of their spatial orientations. Three-dimensional echocardiography (3DE) may produce any desired cross-sectional views and reconstruct 3-dimensional images from a volumetric data set. Its role in CA imaging has not been fully explored. The aim of this study was to evaluate the potential of 3DE in visualizing CAs and in assessing the severity of stenosis. We performed transesophageal 3DE in 46 patients. Images were collected sequentially with the transducer rotated through 180 degrees. From the 3DE data sets of all 46 patients, cross-sectional views and 3-dimensional images of CAs were reconstructed. For segment-by-segment comparison between CA angiography and 3DE in semiquantitative analysis of coronary stenosis, 5 segments were defined for the proximal CA tree in 20 patients who underwent both procedures. The left main, anterior descending, circumflex, and right CAs were visualized from 3DE in 100%, 100%, 98%, and 72%. The available lengths of these segments from 3DE were 12+/-4 mm (range 4 to 22), 15+/-6 mm (range 6 to 36), 30+/-12 mm (range 13 to 60), and 18+/-9 mm (range 6 to 36), respectively. Comparison between 3DE and CA angiography in semiquantitative estimation of CA stenosis resulted in complete agreement in 83% of the segments (kappa value = 0.7). The sensitivity and specificity of 3DE in detecting significant stenosis (> or =50%) were 84% and 97%. In conclusion, transesophageal 3DE allows imaging of the proximal CA, detection of stenotic lesions, and estimation of the severity of stenosis.

Does the pulmonary autograft in the aortic position in adults increase in diameter? An echocardiographic study.

OBJECTIVE: The objective of this study was to discern the fate of the pulmonary autograft diameter over time in adults and its relation to aortic regurgitation in the setting of aortic root replacement. METHODS: From January 1989 to May 1995, 36 consecutive adult patients underwent aortic root replacement with a pulmonary autograft for aortic valve disease. The mean age of 20 male and 16 female patients was 29.1 years (range 19.3 to 52.1 years). The mean follow-up was 2.3 years (range 0.3 to 6.0 years). Two patients died in the hospital. One other patient had a second operation for stenosis at the distal suture line of the allograft in the pulmonary position. Pulmonary autograft anulus and sinus diameters were measured with epicardial echocardiography before (only anulus) and after cardiopulmonary bypass, with transthoracic echocardiography at hospital discharge, and with transesophageal echocardiography during follow-up. RESULTS: The mean autograft anulus diameter did not increase immediately after cardiopulmonary bypass (mean diameter 26.2 mm before and 26.4 mm after cardiopulmonary bypass). The mean autograft sinus diameter after cardiopulmonary bypass was 36.5 mm. The mean autograft anulus diameter increased to 31.5 mm at follow-up, an increase of 5.1 mm (19%). The mean autograft sinus diameter increased to 43.9 mm at follow-up, an increase of 7.4 mm (20%). Fifty-nine percent of the anulus diameter increase and 40% of the sinus diameter increase was already reached at hospital discharge (7 to 10 days after the operation); the other part of the increase occurred during follow-up. Diameter increase was associated with neither the length of follow-up (follow-up less than 1 year compared with a longer follow-up) or severity of aortic regurgitation. CONCLUSION: Pulmonary autograft anulus and sinus diameters increase the first year after aortic root replacement with a pulmonary autograft. This occurs rapidly within 10 days after the operation, with a further increase during follow-up, without causing significant aortic regurgitation at medium-term follow-up.

Intraoperative two-dimensional echocardiography in complicated infective endocarditis of the aortic valve.

Six patients with complicated native and prosthetic aortic valve endocarditis were operated on. The data from cineangiocardiography and from precordial and intraoperative two-dimensional echocardiography were compared with the surgical findings. Surgical inspection revealed a mycotic aneurysm in six patients. In addition, a fistulous connection to the right atrium, an abscess in the interventricular septum, and mitral valve endocarditis were found in one of the patients. The pathologic conditions disclosed during the operation were correctly visualized with two-dimensional epicardial echocardiography, done before cardiopulmonary bypass. Cineangiography provided this information in one patient, and precordial two-dimensional echocardiographic analysis was correct in two patients. Thus, intraoperative two-dimensional echocardiography provides detailed information in complicated native and prosthetic aortic valve endocarditis that is of importance in the surgical management.

Repair of commissural prolapse by extended leaflet sliding.

Three patients had chronic mitral regurgitation due to commissural chorda rupture with commissural prolapse. Two of them had myxomatous valve disease and 1 had fibroelastic deficiency. Characteristic intraoperative epicardial and transesophageal echocardiographic findings are demonstrated. A technique is proposed that involves creating a new commissure and avoiding annular plication by extended sliding plasty and rotating the posterior mitral leaflet.

Progressive pulmonary autograft root dilatation and failure after Ross procedure.

We present a case of progressive pulmonary autograft root dilatation and subsequent failure after a Ross procedure. The explanted autograft vessel wall revealed striking histologic findings indicative of chronic media rupture. Examination of another explanted pulmonary autograft root showed similar histologic changes, suggesting a common phenomenon in pulmonary autograft roots. It may be the cause of progressive root dilatation as observed after Ross operations.