Dilatation Of Pulmonary Autograft Research Articles

Pulmonary Autograft Dilatation and its Risk Factors After Classical Ross Procedure: a Retrospective Single Center Study

Introduction. Aortic valve replacement with pulmonary autograft (Ross procedure) demonstrated excellent immediate and long-term results. Dilation of the pulmonary autograft in the long-term period is the main reason for repeated surgery. Aim: to study the prevalence of pulmonary autograft dilatation and its risk factors. Materials and methods. From April 2009 to December 2022, 158 patients underwent classical Ross surgery. Inclusion criteria: patients aged 18 and older, patients who underwent classical surgery. Exclusion criteria: patients under 18, modifi ed methods of Ross procedure. Follow-up period: 104 (49–124) months. Results and discussion. The median age of patients was 33 (25–43) years. Hospital mortality accounted for 0.6 %. Perioperative myocardial injury was 3.8 %, conduction disorder requiring permanent pacemaker implantation accounted for 1.9 %, the incidence of strokes and acute kidney injury requiring hemodialysis was 0.6 %. Ten-year freedom from autograft reoperation was 88.4. Ten-year freedom from reoperation for aortic aneurysm accounted for 92 %. Predictors of autograft dilatation in the long-term period were: age (OR: 0.942; 95% CI: 0.901–0.984, p = 0.008) and the initial size of sinuses of Valsalva (OR: 1.18; 95% CI: 1.027–1.215, p = 0.01). Conclusion. Ten-year freedom from autograft reoperation due to aortic dilatation and freedom from aortic dilatation ≥ 45 mm was 92 % and 37.2 %, respectively. The main predictors of autograft dilatation in the postoperative period are the age and the initial diameter of the sinuses of Valsalva.

Modified Ross operation (literature review)

One of the surgical methods for treating aortic valve pathology is the Ross operation, which was proposed by the British cardiac surgeon D. Ross in 1967. Numerous studies have shown excellent long-term outcomes of this operation. However, in some patients, pulmonary autograft dilatation may occur in the long term. To avoid this complication, technical modifications of this procedure have been proposed. A literature review on modified Ross operation as a prevention of pulmonary autograft dilatation is presented.

The Ross procedure is an excellent operation in non-repairable aortic regurgitation: insights and techniques.

The Ross procedure is the best operation to treat aortic stenosis (AS) in young and middle-aged adults. However, its role in non-repairable aortic regurgitation (AR) remains debated since many historical series have reported an increased risk of pulmonary autograft dilatation and subsequent need for reintervention in these patients. Some have attributed these findings to an unrecognized and poorly characterized inherited genetic defect that prevents adaptive remodelling of the pulmonary autograft. Herein, we review the contemporary evidence surrounding the use of the Ross procedure in young adults with AR and put forth the argument that with proper technical refinements, the Ross procedure may still be the best operation to treat these patients. We believe that by tailoring the operation to the patient's anatomy and ensuring strict postoperative blood pressure control, one can achieve excellent results with the Ross procedure, including in this challenging patient population.

Distinct Expression of Nonmuscle Myosin IIB in Pulmonary Arteries of Patients With Aortic Stenosis vs Insufficiency Undergoing a Ross Procedure

BackgroundClinical studies have revealed a greater risk of pulmonary autograft dilation after the Ross procedure in patients with preoperative aortic insufficiency (AI). The present study examined whether the morphologic, biomechanical, and cellular properties of the pulmonary artery (PA) from patients with AI were phenotypically different compared with patients diagnosed with aortic stenosis (AS). MethodsPA segments were harvested from patients undergoing the Ross procedure for AS (n = 16) and AI (n = 6). Preoperative aortic annulus was significantly larger (P < 0.05) in patients with AI (28.5 ± 1.8 mm) vs AS (22.8 ± 1.2 mm). Morphologic, biomechanical, and cellular phenotypes of the PA were analyzed. ResultsCollagen and elastin content in the media of the PA wall were similar in patients with AS and AI. Elastic modulus and energy loss of the PA were not significantly different between the groups. In the media of the PA, expression of a panel of vascular smooth muscle cell–specific proteins were similar in patients with AS and AI. In contrast, nonmuscle myosin IIB protein levels in the PA of AS patients were significantly higher compared with AI patients, and immunofluorescence identified staining in α-smooth muscle actin–positive vascular smooth muscle cells. ConclusionsDespite similar morphological and biomechanical properties, the disparate expression of nonmuscle myosin IIB protein distinguishes the PA of patients with AI from patients with AS. The biological role in vascular smooth muscle cells and the potential contribution of nonmuscle myosin IIB to pulmonary autograft dilation in a subset of AI patients after the Ross procedure remain to be determined.

Biomechanical evaluation of a personalized external aortic root support applied in the Ross procedure.

A commonly heard concern in the Ross procedure, where a diseased aortic valve is replaced by the patient's own pulmonary valve, is the possibility of pulmonary autograft dilatation. We performed a biomechanical investigation of the use of a personalized external aortic root support or exostent as a possibility for supporting the autograft. In ten sheep a short length of pulmonary artery was interposed in the descending aorta, serving as a simplified version of the Ross procedure. In seven of these cases, the autograft was supported by an external mesh or so-called exostent. Three sheep served as control, of which one was excluded from the mechanical testing. The sheep were sacrificed six months after the procedure. Samples of the relevant tissues were obtained for subsequent mechanical testing: normal aorta, normal pulmonary artery, aorta with exostent, pulmonary artery with exostent, and pulmonary artery in aortic position for six months. After mechanical testing, the material parameters of the Gasser-Ogden-Holzapfel model were determined for the different tissue types. Stress-strain curves of the different tissue types show significantly different mechanical behavior. At baseline, stress-strain curves of the pulmonary artery are lower than aortic stress-strain curves, but at the strain levels at which the collagen fibers are recruited, the pulmonary artery behaves stiffer than the aorta. After being in aortic position for six months, the pulmonary artery tends towards aorta-like behavior, indicating that growth and remodeling processes have taken place. When adding an exostent around the pulmonary autograft, the mechanical behavior of the composite artery (exostent + artery) differs from the artery alone, the non-linearity being more evident in the former.

Abstract 12524: Changes in Pulmonary Autograft Wall Stresses Immediately After the Ross Operation: First Steps Towards Understanding Aneurysmal Remodeling

Introduction: Pulmonary autograft dilatation is the Achilles heel of the Ross operation, often necessitating reoperation. To understand normal and abnormal autograft remodeling, first biomechanical understanding of human autografts after exposure to systemic pressure is required. Our aim was to quantify biomechanical wall stresses on normal autografts after Ross operation prior to remodeling and dilatation. Hypothesis: Elevated pressure of systemic circulation results in increased autograft wall stress to drive biomechanical remodeling. Methods: We previously developed a normal human autograft model using micro-computed tomography to obtain zero-pressure luminal geometry. Material properties of normal human autografts (n=9) was obtained by bi-axial stretching. Patient-specific zero-pressure wall thickness was incorporated. Autograft diameter and wall stress were determined at pulmonic and systemic pressures using finite element analyses. Results: At systemic systole, mean autograft diameter was 35.0±1.7mm at sinuses and 33.4±1.3mm at sinotubular junction (STJ); while at pulmonary systole, they were 32.5±1.9mm and 30.5±1.4mm, respectively. Distensibility, percent change in diameter from diastole to systole, was 1.4% at systemic pressures versus 3.0% at pulmonary pressures. Peak von Mises wall stress was 581±449kPa at systemic systole compared to 89.7±65.3kPa at pulmonic systole. Average wall stress at systemic systole was 223±88.3kPa and at pulmonic systole was 37.4±16.8kPa (Fig 1). Conclusions: Normal human pulmonary autograft biomechanical responses to systemic pressure were quantified. Nearly 6 fold increase in peak and average wall stress was observed at systemic pressures. Regions of peak stresses were observed in the sinuses. This data will serve as a necessary control for future comparison to aneurysmal pulmonary autografts, and will enable better understanding of patient-specific risk for autograft dilatation.

An experimental model of the Ross operation: Development of resorbable reinforcements for pulmonary autografts

To circumvent the issue of pulmonary autograft (PA) dilation after the Ross procedure, surgical reinforcement strategies have been suggested in clinical or anecdotal series. However, no preclinical large-animal model of the Ross procedure is available, which is needed to enable full comprehension of the pathologic mechanisms and the effectiveness of reinforcement techniques during growth. Our aim was to develop a large-animal model of the Ross operation, to reproduce the clinical scenario in which this procedure might be applied, and allow for development and testing of various devices and techniques to improve PA performance. In addition, we aimed to test the effectiveness of a bioresorbable mesh for PA reinforcement. An experimental model of transposition of the pulmonary trunk as an autograft in the aortic position has been developed and performed under cardiopulmonary bypass in 20 growing lambs, aged 3 months. The experimental design included: a control group that underwent PA transposition; a group in which the PA was reinforced with an external, synthetic, nonresorbable, polypropylene grid; and a group that received various combinations of resorbable meshes. Animals were followed up during growth for 6 months by angiography and echocardiography and eventually killed for pathologic analysis. All animals survived the procedure with no complications. The model was easy and reproducible. Resorbable meshes prevented PA dilation and preserved its progressive growth process, aiding histologic remodelling. We developed an easy and reproducible model of the Ross procedure, allowing for a reliable simulation of the clinical scenario. Resorbable PA reinforcement may represent an interesting option in this context.

BIOMECHANICAL PROPERTIES OF PATIENT-SPECIFIC AORTAS AND PULMONARY ARTERIES ACCORDING TO AORTIC VALVE PHENOTYPE: RELEVANCE TO THE ROSS PROCEDURE

The Ross procedure consists of replacing a diseased aortic valve with the patient’s own pulmonary valve and root. In some instances, patients develop pulmonary autograft dilatation and regurgitation, requiring re-operation. It has been suggested that bicuspid aortic valves are associated with autograft dilatation, which has led some to contraindicate the Ross procedure in this patient population. However, bicuspid aortic valves are very prevalent in the age group that would benefit the most from this procedure. The aim of this study was to compare the biomechanical properties of aortas (Ao) and pulmonary arteries (PA) according to aortic valve phenotype (tricuspid, bicuspid and unicuspid), in patients undergoing the Ross procedure. At the time of surgery, segments of anterior aortic and PA wall (1x1cm) were obtained and categorized according to phenotype, from 27 patients undergoing the Ross procedure. The segments were subjected to displacement-controlled biaxial stretch testing within 8 hours of surgery, at 37 degrees Celsius in a physiological solution. Tissue stiffness (elastic modulus) at an engineering strain of 60% was evaluated in the longitudinal and circumferential axes. Fourteen patients were male (52%) and mean age was 47±13 years. Aortic valve phenotype was bicuspid in 17 patients (63%), unicuspid in 7 patients (26%) and tricuspid in 3 patients (11%). Surgical indication was aortic stenosis in 19 patients (70%), mixed disease in 5 patients (19%), aortic regurgitation in 2 patients (7%) and endocarditis in 1 patient (4%). When comparing PAs from patients with different aortic valve phenotypes, there were no significant differences in PA thickness (p=0.57), circumferential elastic modulus (p=0.7) and longitudinal elastic modulus (p=0.47). Comparisons between Ao and PA within each valve phenotype group showed no differences between Ao and PA longitudinal elastic moduli in unicuspid and bicuspid patients (p=0.11 and p=0.14, respectively). Similarly, circumferential elastic modulus between Ao and PA was similar in the unicuspid population (p=0.44). In contrast, PAs from the bicuspid population were significantly less stiff in the circumferential axis than their respective Ao (0.10±0.06 MPa vs 0.17±0.06 MPa, p=0.01). Despite the small sample size, current findings suggest that the biomechanical properties of PAs obtained from patients undergoing the Ross procedure are independent of aortic valve phenotype. These findings suggest that changes in autograft dimensions in the long term are not related to the intrinsic biomechanical properties of PAs. Further analyses are warranted to correlate these findings with histological sections and to determine their clinical significance.

A Single-Center Experience With the Ross Procedure Over 20 Years

The Ross procedure offers several potential advantages in a young patient population. The widespread use of the procedure is still limited due to the technical challenge. Pulmonary homograft stenosis and autograft dilatation remain a matter of concern. We present the long-term outcome in a single center with special emphasis on mortality and need for valvular reintervention. All patients who received a Ross procedure as freestanding root replacement (modified Yacoub technique) at our institution between 1991 and 2011 were followed. Descriptive statistical methods and Kaplan-Meier analyses were performed. A total of 246 patients (191 males, 55 females) underwent the Ross procedure during the study period. There were 176 adults and 70 pediatric patients with an average age of 36 ± 10 and 10 ± 5 years, respectively. The median follow-up was 10 years. Twelve (4.9%) subjects were lost to follow-up. Early mortality was 1.6%. Overall mortality was comparable with an age and sex matched population for adult patients. The linearized risk for reoperation per patient-year was 0.6% for the autograft and 0.6% for the right ventricular outflow tract, with a mean time to surgery of 6.4 ± 4.9 years. Overall freedom from reintervention was 95% at 5 years, 88% at 10 years, and 81% at 15 years. The Ross procedure provides good early results and an excellent long-term survival. It represents an excellent method of aortic valve replacement in children and young adults. Root reinforcement techniques and aortic reduction plasty may be beneficial, especially in adult patients with native aortic valve regurgitation.

2000 patient years of follow up after the Ross Procedure in a single center

Objective: The Ross Procedure offers several advantages in a young patient population requiring aortic valve replacement. Outcome data after the Ross Procedure are still conflicting. Reoperations are usually due to pulmonary homograft stenosis or autograft dilatation and are a matter of concern. This report focuses on the incidence of reoperation and mortality after the Ross Procedure in a single center.

The modified Ross operation using a Dacron prosthetic vascular jacket does prevent pulmonary autograft dilatation at 4.5-year follow-up

Following the Ross operation, pulmonary autografts tend to dilate over time. This study researches the fate of the pulmonary autograft - at 4.5 years following the modified Ross operation - with special reference to the impact of the modification on (a) pulmonary autograft dilatation, (b) the neo-aortic root geometry, (c) neo-aortic valve function and (d) the coronary artery reserve. A total of 26 patients who underwent the Ross operation were included in this study; of these, 13 consecutive patients underwent a modified Ross operation in which the free-standing autograft root was supported externally by a Dacron vascular prosthetic jacket (DVPJ). These patients were compared to a cohort of 13 matched patients who were operated on using the conventional Ross technique; all patients were followed up prospectively by echocardiography studies. The patients who underwent the modified Ross operation were also subjected to bicycle ergometry. At the 47-month median follow-up, there was no significant increase in the size of the entire neo-aortic root in the patients who underwent the modified Ross operation; in addition, the geometry of the neo-aortic root was also preserved and the left ventricular function had improved significantly, whilst the aortic valve function and excursion remained satisfactory. All patients, with one exception, in the modified Ross operation group exhibited normal exercise capacity. By contrast, there were significant differences in diameters of the aortic root - between the two surgical techniques in favour of the modified Ross technique - following a median follow-up of 23 months in the patients subjected to the conventional Ross operation. Provision of external support to the entire pulmonary autograft with a DVPJ prevents its dilatation following free-standing pulmonary autograft Ross operation when evaluated at the 4.5-year follow-up. The function and the geometry of the neo-aortic root are not affected negatively by this modification and the patients demonstrated normal exercise capacity.

A modification of the Ross procedure to prevent pulmonary autograft dilatation

We present our initial experience in 10 patients operated on using a modified Ross operation. In our modification of the Ross operation the pulmonary autograft root was inserted in the Gelweave Valsalva graft to prevent dilatation of the neoaortic root. This type of graft was selected to match the discrepancy between diameters of the annulus and the sinotubular junction of the autograft and to preserve the characteristic configuration of the native root. In our group of 10 patients operated consecutively by this technique there was no change in the geometry of the neoaortic root in the follow-up 3-19 months (mean 14.6 months).

Valve-Sparing Operation for Aortic Root Aneurysm Late After Mustard Procedure

The aortic valve reimplantation technique leads to excellent clinical outcome in patients with aortic valve incompetence and aneurysms of the ascending aorta. This technique is now applied for aneurysms of ascending aorta, aortic dissection type A, and even dilatation of pulmonary autograft after the Ross operation. We report a case of aortic root dilatation late after a Mustard operation for transposition of the great arteries that was successfully managed by valve-sparing aortic root reimplantation.

Incidence of and Risk Factors for Pulmonary Autograft Dilation After Ross Aortic Valve Replacement

The Ross procedure is an alternative to mechanical aortic valve replacement in the young. Early dilation of the pulmonary autograft root exposed to the systemic circulation has been reported. The aim of our study is to define the prevalence, risk factors, and consequences of autograft dilation. All consecutive adult and pediatric patients who underwent Ross procedure at our institution were retrospectively reviewed for autograft dilation. Between 1993 and 2005, 170 patients (mean age, 24.9 +/- 15.5 years; range, 1 month to 61 years) underwent Ross aortic valve replacement: 48% were younger than 19 years old. Eighty-seven additional procedures were performed in 58 patients (34%) at the time of the Ross procedure. End points of the study were freedom from autograft dilation (z value more than +2.0), autograft dysfunction, autograft reoperation, and autograft replacement. There were 2 early and 1 late deaths during a mean follow-up of 5.1 +/- 3.0 years (range, 1 month to 12 years). Actuarial survival at 10 years was 98%. Autograft dilation was identified in 31 patients (19%). Regurgitation (>2+) was identified in 12 patients (7%); all 12 had autograft dilation. At 10 years, freedom from autograft dilation was 82%, freedom from autograft dysfunction was 92%, freedom from reoperation on autograft was 92%, and freedom from autograft replacement was 96%. Cox proportional hazard analysis identified preoperative aortic annulus dilation (z value more than +2.0; p = 0.004), younger age (p = 0.05), time of surgery (before 2001; p = 0.002), and male sex (p = 0.01) as predictive of autograft dilation, whereas preoperative ascending aorta diameter (p = 0.01), male sex (p = 0.03), and postoperative systemic hypertension (p = 0.05) were predictive of autograft dysfunction. Significant autograft dilation is not common after the Ross procedure. Significant autograft dysfunction affects a minority of patients, but it is more prevalent in those with autograft dilation.

A modified Ross operation to prevent pulmonary autograft dilatation

A modification in Ross operation is described in which the free-standing pulmonary autograft root is suspended in a Dacron prosthetic vascular jacket with a view to prevent dilatation of the neo-aortic root. In a group of 13 patients operated consecutively using this technique, there was no significant increase in the diameters of the neo-aortic root after a mean 16-month follow-up. Aortic valve function remained also satisfactory.

Results of the Ross operation in a pediatric population

To analyse the results of the mid-term clinical and echocardiographic follow-up of the pediatric Ross operation. Echo-Doppler follow-up of 53 consecutive pediatric Ross procedures performed between 1994 and 2003. Median age was 9.7 years at time of operation (2 weeks-17.7 years). Six patients were younger than 3 months. Median age at follow-up was 15.6 years. Aortic valve/left ventricular outflow tract (LVOT) anomalies were congenital in 49 (92%). Seventy percent had previous surgery or balloon valvuloplasty. Root replacement was used in all. Thirteen patients (25%) had LVOT enlargement. Mean cross-clamp time was 113 (69-189) minutes. Early mortality occurred in 3 patients after emergency surgery following balloon failure (n=1) and extended Ross following interrupted arch/VSD repair (n=2). Late mortality was due to LV fibroelastosis in 2 patients and complicated pulmonary artery stenting in another. RVOT reoperations were required because of late homograft obstruction in 2 patients and because of pulmonary artery stenosis in another. Five patients (9.4%) were reoperated for pulmonary autograft dilatation (n=3) and for leaflet fibrosis or perforation (n=2). Autografts were repaired in two patients, while a mechanical valve was inserted in 3 cases. At 9 years the actuarial survival and event free survival were 89 and 74%, respectively. At last follow-up 90% of autograft diameters indexed to body surface area was above the 90th percentile of normal aortic root diameters. LVOT and RVOT gradients were low and autograft insufficiency was trivial to mild in 84% and mild to moderate in 16%. Autograft stenosis was not noticed. The pediatric Ross procedure remains an important tool but autograft dilatation also occurs in the pediatric population. The significance of this finding has yet to be determined.

Valve-sparing root replacement for pulmonary autograft dissection late after the Ross operation

Aortic valve replacement with the pulmonary autograft (ie, the Ross operation) is generally associated with satisfactory early and late results. Complications, however, can occur, including the tendency of the pulmonary autograft root to dilate with time. Whereas neoaortic root dilatation might be observed in as many as one third of patients late after the Ross operation, uncertainty still exists as to the rate of progression toward true aneurysmal disease (aortic diameter 5 cm). Furthermore, the actual risk of complications, such as neoaortic rupture or dissection, is also unknown. The yet undefined natural history of root dilatation after the Ross operation, the often satisfactory competence of the pulmonary autograft valve, the scarcity of valid therapeutic alternatives (particularly in the infant and child), and the complexity–risk of reintervention have thus far delayed standardization of therapeutic indications. In particular, timing and technique of reoperation on the aneurysmal neoaortic root are still controversial. Here we present a case of potentially lethal evolution of progressive pulmonary autograft dilatation (ie, neoaortic root dissection) successfully treated with valve-sparing root replacement. The implications in terms of natural history and indications for reintervention are discussed.

Structural and biomolecular changes in aorta and pulmonary trunk of patients with aortic aneurysm and valve disease: implications for the Ross procedure.

A higher incidence of pulmonary autograft dilatation is assumed in patients with ascending aortic dilatation and bicuspid aortic valve disease. To examine whether structural abnormalities are present in the ascending aorta as well as in the pulmonary trunk (PT) we specifically addressed molecular mechanisms and signalling pathways for aneurysm formation in ascending aortic aneurysms and PT of patients with different aortic valve pathology undergoing an extended Ross procedure. Wall segments resected from aortic aneurysms (20 patients, 7 bicuspid aortic valves BAV, and 13 tricuspid aortic valves TAV) and from PTs were submitted to analysis of leukocyte infiltration (immunohistochemistry), smooth muscle cell (SMC) apoptosis (in situ end-labelling of DNA-fragments TUNEL), and expression of death-promoting proteins perforin, granzyme B, Fas/FasL (immunoblotting). Degenerative changes including rarefication and apoptosis of SMCs were significantly more severe in BAV than TAV disease (apoptotic index 9.2+/-3.2 vs. 11.9+/-6.2, P = 0.02). Immunohistochemistry confirmed presence and activation of death-promoting mediators in aneurysmal tissue whereas pulmonary tissue displayed only few apoptotic cells, occasional Fas+cells, rarely colocalized with FasL. By Western blot analysis extracts from BAV and TAV but not pulmonary artery wall contained appreciable amounts of perforin, granzyme B, and Fas/FasL. Aneurysm formation is associated with SMC apoptosis and local signal expression of activated cells in patients with bicuspid as well as TAV. The PT itself is not pathologically involved with only minor degenerative changes. Although the disease process in the aorta appeared to be more severe in patients with BAV, there was similarity of histological and molecular changes of the pulmonary artery wall in all patients. Dilation of the pulmonary autograft seems not to be the result of histopathological and biomolecular mechanisms in the PT.

Aortic root reimplantation for successful repair of an insufficient pulmonary autograft valve after the Ross procedure

J Thorac Cardiovasc Surg 2002;124:1048-9

Dilation of the pulmonary autograft after the ross procedure

Objective: Dilation of pulmonary autograft after the Ross procedure is being recognized with increasing frequency. This study was undertaken to examine the extent of this problem and factors that may be associated with it. Methods: The clinical, operative, and echocardiographic data of 118 patients who underwent the Ross procedure were reviewed. The mean age of 79 men and 39 women was 34 ± 9 years, range 17 to 57 years. Bicuspid or other congenital aortic valve disease was present in 81% of patients. The pulmonary autograft was sutured as a valve in the subcoronary position in 2 patients, as a root inside of the aortic root in 45, and was used for complete aortic root replacement in 71. Teflon felt was not used to buttress the proximal or the distal anastomosis of the pulmonary autograft. The diameters of the sinuses of Valsalva, aortic anulus, and sinotubular junction were measured early and late after the operation with echocardiography. The mean follow-up was 44 months. Results: The diameter of the sinuses of Valsalva increased from 31.4 ± 0.4 mm to 33.7 ± 0.5 mm ( P = .01). Analysis of covariance revealed a significant change over time in this diameter, as well as a difference between operative techniques, with replacement of the aortic root being associated with a higher risk of dilation ( P = .0006). In 13 patients the diameter ranged from 40 to 51 mm. The diameter of the aortic anulus decreased in most patients and increased in 15, but there was no interaction between these changes and the operative technique. The diameter of the sinotubular junction increased in patients who had aortic root replacement and decreased in patients who had aortic root inclusion ( P = .007). Moderate aortic insufficiency developed in 7 patients, and 3 required replacement of the pulmonary autograft. All patients with moderate aortic insufficiency had dilation of the aortic anulus and/or sinotubular junction. Conclusions: Dilation of the pulmonary autograft after the Ross procedure may occur because of an intrinsic abnormality of the pulmonary root in patients with congenital aortic valve disease. The technique of aortic root replacement is associated with a higher risk of dilation of the sinuses of Valsalva and sinotubular junction than the technique of aortic root inclusion. (J Thorac Cardiovasc Surg 2000; 119:210-20)