Hemodynamic performance during maximum exercise in adult patients with the ross operation and comparison with normal controls and patients with aortic bioprostheses

This study examines the resting and exercise hemodynamic performance of the pulmonary autografts in the aortic position as well as of the homografts used for right ventricular outflow reconstruction in patients undergoing the Ross operation. Previous studies have reported excellent resting hemodynamics in patients who underwent aortic valve replacement with a pulmonary autograft. However, there are very few studies of their hemodynamic performance during exercise. Twenty adult subjects who underwent the Ross operation and 12 normal control subjects were submitted to maximum romp bicycle exercise. The valve effective orifice areas and transvalvular gradients of both aortic (autograft) and pulmonary (homograft) valves were measured at rest and at peak of maximum exercise using Doppler echocardiography. Valve areas were indexed for body surface area. The hemodynamics of the aortic valve were very similar in Ross subjects and in control subjects at rest and during exercise. However, the indexed valve area of the pulmonary valve at rest was significantly (p < 0.001) lower in the Ross subjects (1.10 +/- 0.46 cm2/ m2) than in the control subjects (1.95 +/- 0.41 cm2/m2), resulting in higher (p = 0.004) mean gradients at rest (Ross: 9 +/- 7 mm Hg vs control: 2 +/- 1 mm Hg) and at peak exercise (Ross: 21 +/- 14 mm Hg vs control: 7 +/- 2 mm Hg). The pulmonary autograft provided excellent hemodynamics in the aortic position either at rest or during maximum exercise, whereas moderately high gradients were found during exercise across the homograft implanted in the pulmonary valve position. Future improvement of the Ross procedure should be oriented toward the search of new methods to prevent the deterioration of the homografts.     

Exercise hemodynamic performance of the pulmonary autograft following the Ross procedure.

BACKGROUND AND AIMS OF THE STUDY: The Ross procedure, in which the aortic valve is replaced with the patient's own pulmonary valve (pulmonary autograft), is considered an excellent alternative for younger patients requiring elective aortic valve replacement. Although resting pulmonary autograft hemodynamics are excellent, exercise hemodynamic data are lacking. The study aim was to measure the hemodynamic performance of the pulmonary autograft with exercise Doppler echocardiography (DE). METHODS: Twenty-four Ross procedure patients (20 males, four females; mean age 46 +/- 11 years) were studied at 25 +/- 14 months after aortic valve replacement with a pulmonary autograft. Patients had baseline supine DE to measure the maximum velocity (Vmax), and the peak and mean pressure gradient across the pulmonary autograft. Effective orifice area was calculated from the continuity equation and indexed to body surface area (EOAi). Patients then underwent symptom-limited upright bicycle exercise with supine DE repeated immediately on stopping exercise. For comparison, 10 normal controls (age 41 +/-10 years) and five mechanical aortic valve patients (mean age 55 +/- 10 years) were studied. RESULTS: At rest: Ross procedure patients had similar Vmax (1.2 +/- 0.2 m/s), peak gradient (6 +/- 2 mmHg), mean gradient (4 +/- 1 mmHg) and EOAi (1.7 +/- 0.4 cm2/m2) to those of normal controls. Mechanical-valve patients had significantly higher Vmax (2.5 +/- 0.2 m/s, p <0.001), peak gradient (25 +/- 4 mmHg, p <0.001) and mean gradient (14 +/- 3 mmHg, p <0.001) than Ross patients and normal controls. At exercise: Ross procedure patients had similar Vmax (1.8 +/- 0.4 m/s versus 2.1 +/- 0.2, p = NS), peak gradient (14 +/- 6 mmHg versus 17 +/- 4, p = NS) and mean gradient (8 +/- 4 mmHg versus 10 +/- 2, p = NS) to normal controls, with no significant change in EOAi. Mechanical-valve patients had significantly higher Vmax (3.4 +/- 0.3, p <0.001), peak gradient (48 +/- 7 mmHg, p <0.001) and mean gradient (30 +/- 5 mmHg, p <0.001) than Ross patients and normal controls. CONCLUSIONS: Aortic valve replacement using the Ross procedure provides excellent hemodynamic results at rest and on exercise, with DE parameters indistinguishable from those of normal controls. This study provides further support for the use of the Ross procedure as a preferred method of aortic valve replacement in younger patients.     

Hemodynamic performance following the Ross operation: comparison of two different techniques

BACKGROUND AND AIM OF THE STUDY: The Ross operation as aortic valve replacement has undergone technical evolution. Originally described as a subcoronary implant, the full-root replacement technique is now more common worldwide. It remains unclear which of the two techniques has the better results. Hence, the hemodynamic performances of the two implantation methods, as applied by two experienced centers, were compared as part of the German Ross Registry. METHODS: In total, 132 (Group 1, root replacement, mean age 40 +/- 14 years) and 249 (Group 2, subcoronary implant, mean age 48 +/- 14 years) consecutively operated patients were compared clinically and echocardiographically. Data were analyzed focusing on pulmonary autograft and homograft function at mid-term (2.78 +/- 1.89 versus 2.26 +/- 2.11 years). RESULTS: Echocardiography revealed autograft peak systolic gradients of 5.0 +/- 2.7 mmHg for Group 1 and 6.7 +/- 3.7 mmHg for Group 2 (p < 0.05), and an indexed effective orifice area (EOA) of 1.98 +/- 0.57 cm2/m2 and 1.64 +/- 0.43 cm2/m2 (p < 0.05), respectively. Homograft peak systolic gradients were 15.6 +/- 9.0 mmHg and 11.7 +/- 6.8 mmHg for Groups 1 and 2 (p < 0.05) respectively, and the indexed EOA with regard to the homograft was 1.08 +/- 0.49 cm2/m2 and 1.26 +/- 0.50 cm2/m2 (p < 0.05). Autograft insufficiency grade > I was present in 1.5% (2/132) of Group 1 and 2.8% (7/249) of Group 2 patients. Pulmonary insufficiency grade > I was 17.4% (23/132) for Group 1 and 4.8% (12/249) for Group 2 (p < 0.05). CONCLUSION: Although both groups enjoyed excellent hemodynamics in the mid-term, the root replacement technique had the advantage of larger annulus diameters and greater aortic EOA. Clinically relevant autograft regurgitation in both groups was gratifyingly rare, and seemed to be independent of surgical technique. Long-term durability of the more demanding subcoronary technique versus the problems of larger dimensions of the sinus of Valsalva and sinotubular junction in the free-root technique, remains to be proven. Apparent differences in pulmonary homograft hemodynamics can most likely be explained by surgical differences, younger patients in Group 1, and by homograft variation.     

The influence of prosthesis size and design on exercise dynamics after aortic valve replacement

BACKGROUND AND AIM OF THE STUDY: Residual gradient following aortic valve replacement (AVR) may adversely affect clinical outcome. The size and design of the valve may influence these characteristics. The study aim was to determine the influence of prosthesis physical size and leaflet design on hemodynamic performance after mechanical AVR. METHODS: After AVR, two patient groups with a range of valve sizes were studied. Group 1 patients (n=19) each received a monoleaflet valve; group 2 patients (n=18) each received a bileaflet valve. Transthoracic echocardiography was performed at rest and after graded bicycle ergometry to assess prosthetic valve parameters, including mean and peak transvalvular gradient and effective orifice area (EOA). RESULTS: Transprosthetic gradients (mean and peak) measured at rest, maximum exercise and 3-min recovery were related to indexed geometric orifice area (IGOA) by an exponential decay function, with no significant advantage for either valve design. However, in valve sizes < or =25 mm the bileaflet valves demonstrated lower gradients, both at rest and under exercise conditions (mean gradient during exercise, bileaflet versus monoleaflet 19.9 +/- 7.2 mmHg versus 25.6 +/- 6.3 mmHg, p = 0.01). Similarly, EOAs were larger in the bileaflet group when equivalent GOAs < or =2.5 cm2 were compared (EOA: bileaflet versus monoleaflet 1.51 +/- 0.33 cm2 versus 1.14 +/- 0.26 cm2, p = 0.018). The total work performed correlated with prosthesis diameter (r2 = 0.81, p = 0.037) and was not influenced by valve design. CONCLUSION: The hemodynamic performance of mechanical aortic valves, including transprosthetic gradient and maximum exercise work performed, related principally to the prosthesis physical size. However, within the smaller valve sizes, the bileaflet design appeared to offer hemodynamic advantages.     

Hemodynamics of semilunar valves at rest and exercise at an average of more than two years after the Ross procedure

BACKGROUND AND AIM OF THE STUDY: Rest, and especially exercise, hemodynamics are valuable determinants to assess outcome of the Ross procedure. In this study, the degree of insufficiency and pressure gradients at rest across the autograft and homograft, as well as the pressure gradients at exercise, were measured. METHODS: Among 115 patients operated on between February 1990 and February 1999, 67 were evaluated echocardiographically at rest and moderate exercise. The mean patient age at subcoronary implantation was 52 +/- 13 years. The mean interval between surgery and investigation was 27.3 +/- 17.4 months. The exercise level was 100 W (n = 47), 75 W (n = 14) or 50 W (n = 6). RESULTS: Fifty-two patients had no or trace aortic insufficiency, 23 were grade I/IV, and two were grade II/IV. Pulmonary insufficiency was graded as none (n = 45), mild (n = 21), and moderate (n = 1). Heart rate increased from 70 +/- 12 beats/min at rest to 108 +/- 19 beats/min at exercise. The maximal pressure gradient across the autograft increased from 6.1 +/- 2.3 mmHg at rest to 8.7 +/- 4.1 mmHg at exercise. The maximal pressure gradient across the homograft increased from 11.8 +/- 5.3 mmHg at rest to 17.7 +/- 8.2 mmHg at exercise. A pressure gradient across the homograft >25 mmHg was measured in 13 patients. CONCLUSION: In most patients, hemodynamics at rest and moderate exercise at an average of more than two years after the Ross procedure were excellent. Some homografts developed pressure gradients at exercise; this finding will form the target of future surgical and scientific investigations.     

应用自体肺动脉瓣置换病变主动脉瓣（附4例报告）

应用自体肺动脉瓣置换病变主动脉瓣、同种肺动脉瓣原拉重建右室流出道（Ross手术）治疗4例主动脉瓣病变患者,成功3例。1例主动脉瓣二瓣化畸形术后存在轻度主动脉瓣返流。超声心动图均提示主动脉根部及同种瓣良好。1例术中误伤自体肺动脉瓣,改机械瓣置换。认为用自体肺动脉瓣置换病变主动脉瓣效果满意,术中预防自体肺动脉瓣损伤和主动脉瓣返流是手术成功的关键,同种肺动脉瓣原位重建右室流出道可为常规选择的管道。     

Echocardiographic follow-up study of the Ross procedure in older versus younger patients

OBJECTIVES: This study was designed to determine echocardiographic follow-up results of the Ross procedure in older adult patients with aortic valve disease. BACKGROUND: The excellent long-term results of the Ross procedure from several institutions have indicated that the pulmonary autograft may be the best available substitute for the diseased aortic valve in children and adolescents. The advantages of this operation include optimal hemodynamics and elimination of thromboembolic complications. These features may benefit older adult patients as well. METHODS: We reviewed data from 49 consecutive patients who had a Ross procedure between 1991 and 1996. Preoperative and postoperative Doppler echocardiographic studies were available for 44 patients (22 men, 22 women; mean [+/-SD] age 36 +/- 14 years) who were grouped into <40 (n = 25) and > or =40 years old (n = 19). Measurements included left ventricular diastolic volume (LVDV), mass, and ejection fraction (EF); a peak pressure gradient across autograft in the aortic position and homograft in the pulmonary position; and valvular regurgitation. RESULTS: The mean length of echocardiographic follow-up was 36 +/- 16 months. Postoperatively, there was a reduction in LVDV and left ventricular mass in both age groups: 153 +/- 99 mL to 111 +/- 72 mL (P =.015) and 210 +/- 93 g to 152 +/- 54 g (P =.002) for younger patients, 174 +/- 115 mL to 126 +/- 43 mL (P =.17) and 233 +/- 71 g to 215 +/- 65 g (P =.19) for older patients. No significant change in EF was noted in the younger age group. However, in the older age group a significant decrease to EF <25% was found in 2 patients 1 year after surgery. Moderate autograft regurgitation was also detected in 2 patients: 1 in each age group. Pressure gradients across the autograft remained within the normal range in both age groups. Two younger patients had severe homograft stenosis with peak gradients of 100 and 62 mm Hg. The older patients did not demonstrate homograft dysfunction. CONCLUSIONS: The Ross procedure can be performed in selected older adults with aortic valve disease and provides durable valves in both aortic and pulmonic positions for at least 3 years after surgery but may result in less favorable left ventricular remodeling compared with that in the younger patients. Further follow-up will be necessary to determine the long-term outcome of the Ross procedure in this older adult patient population.     

Ross operation in aortic valve diseases

Currently used standard mechanical and bioprosthetic heart valves all have limitations that produce less than optimal results. The pulmonary autograft offers a promising alternative with theoretical advantages that have to be proven for final judgement of this innovative surgical technique. METHODS AND RESULTS: A survey including the international registry with 2523 patients enrolled since 1987 is provided along with the author's 10 years experience of 157 patients. The age of the patients ranges between one and 79 years. The indication is expanding integrating concomitant procedures like repair or replacement of aneurysms of the aortic root and ascending aorta, mitral valve reconstruction, coronary bypass grafting, etc. The operative mortality ranges between 0.6 and 2.5%. No anticoagulation is necessary. The function of the autograft is excellent. Late incidence of significant aortic insufficiency (> 2+) remains less than 5%. Even at exercise there is no pressure gradient across the autograft. Autograft failure with autograft revision or replacement stands at 1-4%. Homograft function is also found to be excellent. Right ventricular outflow tract revision rate ranges between 1-1.3%. In a few patients (7%), maximal pressure gradients between 20 and 35 mmHg developed across the homograft without major impairment of right ventricular function. CONCLUSIONS: The multicenter data confirm the superior performance of the autograft not matched by any other biological or mechanical valve replacement. Scientific efforts are required to further improve long-term function especially of the neopulmonary valve.     

Ross operation in children: late results.

BACKGROUND AND AIM OF THE STUDY: Although the Ross operation has become the accepted aortic valve replacement in children, the long-term fate of the pulmonary autograft valve remains unknown. To assess mid-term and late results of autograft valve durability, patient survival and valve-related morbidity, a retrospective review of patients (age range: 3 days to 17 years) having a Ross operation between November 1986 and May 2001 were reviewed. METHODS: Medical records and patient contacts with all but two of 167 current survivors of 178 consecutive patients having an aortic valve replacement as a Ross operation have been completed during the past two years. The most recent echocardiographic evaluation was reviewed for autograft valve and homograft valve function. RESULTS: Operative mortality was 4.5% (8/178), with three late deaths (two were non-valve-related) for an actuarial survival of 92+/-3% at 12 years. Actuarial freedom from autograft valve degeneration (reoperation or severe insufficiency of autograft valve or valve-related death) was 90+/-4% at 12 years. Autograft valve degeneration was not affected by technique of insertion (141 root replacement, 37 intra-aortic), aortic valve morphology (157 bicuspid or unicuspid, 26 tricuspid), or age at operation. Autograft valve degeneration was worse in patients with a primary lesion of aortic insufficiency than in those with aortic stenosis (p = 0.03). Autograft valve reoperation was required in 12 patients, with autograft valve replacement in seven. Actuarial freedom from autograft replacement was 93+/-3% at 12 years. Homograft valve replacement was required in seven patients, with actuarial freedom from replacement of 90+/-4% at 12 years. Eight additional patients have homograft valve obstruction (gradient > or =50 mmHg), and seven have severe pulmonary insufficiency. CONCLUSION: Survival and freedom from aortic valve replacement are excellent in children. Homograft valve late function remains a concern, and efforts to improve homograft durability should be encouraged.     

The Ross procedure as the surgical treatment of active aortic valve endocarditis

BACKGROUND AND AIM OF THE STUDY: The authors' experience is reported of aortic valve replacement (AVR) using the pulmonary autograft in patients with active aortic valve endocarditis, including an urgent Ross procedure in infants with the acute condition. METHODS: Nine patients aged between 8 months and 38 years, with a diagnosis of aortic valve endocarditis, have undergone AVR using the Ross procedure at the authors' institution since October 1997. The diagnosis was established by clinical and echocardiographic findings. Indications for surgery were severe aortic insufficiency and congestive heart failure in all patients, with the addition of thromboembolic events (n = 3), persistent hyperpyrexia (n = 3) and vegetations (n = 5). Four infants with no history of congenital cardiac malformation underwent urgent surgery because of acute bacterial endocarditis and rapid hemodynamic deterioration. Blood cultures were positive for Streptococcus pneumoniae in three patients, and Kingella kingi and Staphylococcus aureus in one patient each. Four patients were culture-negative. All patients were treated with intravenous antibiotics for four to six weeks postoperatively. RESULTS: There were no perioperative or late deaths, and no recurrent endocarditis at the implanted valves. Echocardiographic evaluation at discharge showed trivial to mild aortic insufficiency, with no stenosis at the left ventricular outflow tract. Similar findings were found across the right ventricular outflow tract. At follow up (range: 4 months to 5.5 years), none of the patients showed progression of aortic valve insufficiency or developed stenosis; three had mild and moderate homograft stenosis (Doppler gradient 20-40 mmHg), and all children had moderate homograft insufficiency. CONCLUSION: The Ross procedure is an excellent therapeutic option for active aortic valve endocarditis in young patients, and demonstrates low morbidity and mortality. Early surgery may be indicated in patients with acute aortic valve endocarditis because of the rapidly progressive nature of this disease.     

Effect of prior aortic valve intervention on results of the Ross operation

BACKGROUND AND AIM OF THE STUDY: Patient-related factors, aortic insufficiency, bicuspid aortic valve, aortic annulus dilatation, ascending aortic dilatation or aneurysm, and aortic valve endocarditis have been suggested as affecting the results of the Ross operation. The study aim was to assess the impact of prior aortic valve intervention on early and late results of a Ross operation. METHODS: A total of 399 patients who underwent surgery between August 1986 and September 2000 were reviewed retrospectively. The patients were grouped as: no prior aortic valve intervention (NOAVI, n = 219); prior aortic valvuloplasty (AVP, n = 106); prior balloon aortic valvuloplasty (AVB, n = 40); and prior aortic valve replacement (AVR, n = 34). Details of operative and late mortality, autograft valve function, and homograft valve function were analyzed. RESULTS: Operative mortality was higher for AVB (10%; three deaths in neonates) than the other groups (from 2.3% to 5.9%) (p = 0.084). Freedom from autograft valve degeneration, defined as severe autograft valve insufficiency, non-endocarditis autograft valve reoperation or valve-related death, ranged from 93 +/- 3% for AVP to 76 +/- 8% for NOAVI at 10 years (p = 0.43). Freedom from homograft reoperation in the pulmonary position was 100% for AVB at six years, and 99 +/- 1% for AVP, 82 +/- 8% for NOAVI, and 70 +/- 13% for AVR at 10 years (p = 0.0026). CONCLUSION: There appears to be no significant difference between patients with and without prior aortic valve surgery, with respect to operative mortality or late autograft function. However, patients with prior AVR appear to have a significantly higher homograft reoperation rate after a Ross operation, the reasons for which are uncertain.     

The Ross procedure in children under ten years of age

BACKGROUND AND AIMS OF THE STUDY: The potential advantages of the Ross procedure in children under 10 years of age have yet to be validated. Concerns remain regarding progressive dilatation of the pulmonary autograft and potential homograft stenosis. We present our experience in this age population. METHODS: A retrospective analysis of aortic root replacement using the Ross procedure in 11 young children (nine males, two females; median age 84 months; range 3 months to 10 years) between January 1996 and January 1999 was performed jointly in two pediatric surgical centers. RESULTS: There were no operative deaths. Mean hospital stay was 12 +/- 4 days, and mean follow up 14.5 +/- 8 months. The event-free survival (death, reoperation, endocarditis, arrhythmia) was 100%. Currently, nine children are in NYHA functional class I, and two in class II. The autograft and homograft were evaluated by serial echocardiography. There was no sign of progressive dilatation of the autograft. Aortic regurgitation was trivial in four children and mild in seven. No growth of the autograft was noted; this was consistent with minimal somatic growth. Homograft peak gradients remained low during the follow up. CONCLUSIONS: Although the pulmonary autograft procedure is more complex than other types of aortic valve replacement, it can be safely applied in children. Early follow up indicates satisfactory performance of the autograft. If dilatation will not occur, pulmonary root autograft may be an attractive substitute for diseased aortic valves in children.     

Stentless xenograft aortic valves

Replacement of the diseased aortic valve represents one of the triumphs of cardiac surgery; however, the perfect valve substitute continues to elude surgeons after almost four decades of clinical experience. The characteristics of the ideal valve substitute include the following: central flow capacity, low transvalvular gradient, low thrombogenicity, durability, easy availability, resistance to infection, non-immunogenicity, and easy implantability. The pulmonary autograft first performed by Ross (Lancet 1967, 2:956-958) came closest to achieving these goals, but creates a double valve procedure for single valve disease. Aortic valve replacement (AVR) with homograft aortic valve was introduced by Ross in 1962 (Lancet 1962, 2:487) and Barratt-Boyes in 1964 (Thorax 1964, 19:131-150). Like the pulmonary autograft, homograft AVR results in an excellent hemodynamic outcome but suffers from limitations of graft availability, lack of durability, and difficulty with implantation. Mechanical valves and stented tissue valves allow "off the shelf" easy availability as well as easy implantability. These valves are unfortunately intrinsically obstructed to some extent because of the space occupied by the stent and sewing ring. Stent mounted tissue valves also continue to exhibit limited durability. Stentless xenograft aortic valves have been developed as a compromise between these ends of the valve spectrum to allow excellent hemodynamics and hopefully improved durability while allowing "off the shelf" availability in a variety of standard sizes. We examine the rationale for use of the stentless xenograft aortic valve, the clinical development of this valve, and the surgical techniques of implantation.     

Aortic valve replacement with pulmonary autograft (the Ross procedure) in adult and pediatric patients

Aortic valve replacement with pulmonary autograft was first performed by Donald Ross in 1967. Initially, the procedure was not widely accepted, by Cardiologists and Cardiac surgeons fundamentally due to its complexity and demanding surgical technique, and because innumerous series two cardiac valves were at risk. The results published in the last 10-15 years established the pulmonary autograft as one of the best methods of aortic valve replacement, especially in pediatric patients and young adults. In the present article, we reviewed present indications and contraindications, and our clinical experience with 26 patients (pediatrics and adults). Analysis of the first 22 the patients with a minimum of 6 months of follow-up (180-620 days) was performed. Follow-up is complete (100%). Mean age was 31.4 +/- 12.6 years. Five patients were pediatrics (<= 14 years). Three patients (11%) with previous percutaneous procedures and 4 patients (14%) with previous surgical procedures. There was no early or late mortality. In the last follow-up, 19 of 22 (86.36%) had no autograft insufficiency (>= grade 1), and in one patient it was moderate (grade 2). The 2 remaining patients developed severe autograft insufficiency (grade 4) and were reoperated on, with satisfactory postoperative outcome. Mean maximal gradient was 7.85 +/- 5 mmHg at 18 months (3-29). Patients with preoperative aortic stenosis showed a significant reduction in myocardial mass index (208.7 +/- 32 a 95.8 +/- 28.8 g/m2) at 18 months. In these patients, septal and posterior wall thickness decreased significantly, in the first month. Two pediatric patients have developed transpulmonar gradient > 50 mmHg. One of them underwent successful stent implantation. We have not observed significant homograft insufficiency in any of our patients. All our patients remain asymptomatic (functional class I) without medical treatment. We have not observed either thromboembolic or haemorrhagic episodes, nor endocarditis. No patient is receiving anticoagulants. Clinical and echocardiographic mid term results in pulmonary autograft and homograft in our series, are excellent after the Ross procedure.     

Fate of the autograft and homograft following Ross aortic valve replacement: reoperative frequency, outcome, and management

BACKGROUND AND AIM OF THE STUDY: The optimal hemodynamic performance and potential for growth of the pulmonary autograft has led to expanded indications for the Ross aortic valve replacement (AVR) procedure in some centers. The authors' institutional mid-term experience was reviewed to assess autograft and homograft hemodynamics, growth profile of the autograft, and reoperative frequency following Ross AVR. METHODS: Between June 1993 and June 2005, 167 consecutive patients (mean age 24.9 +/- 15.5 years; range: 1 month to 61 years) underwent Ross AVR: 48% of patients were aged < 19 years. Additional procedures (n = 78) were performed in 55 patients (33%) at the time of the Ross procedure. In total, 151 patients had isolated aortic valve disease and 16 pediatric patients had more complex, multi-level left ventricular outflow tract obstruction. RESULTS: There were two early deaths (1.2%) and one late death (0.6%) over a mean follow up of 5.1 +/- 3.0 years (range: 1 month to 11 years). Actuarial survival at 10 years was 98%. In pediatric patients with Konno procedure (n = 16), the pulmonary autograft mean annulus diameter increased from 10.2 to 19.9 mm. Twelve patients underwent 12 reoperations without mortality for autograft insufficiency or an ascending aortic aneurysm at a median interval of 5 years (range: 2 to 8 years): aortic annuloplasty and ascending aorta replacement (n = 4), composite aortic root replacement (n = 7), and repair of left ventricular pseudoaneurysm (n = 1). Freedom from replacement of the pulmonary autograft was 96% at 10 years. Five of the 164 surviving patients (3%) developed significant obstruction of the pulmonary homograft and required conduit replacement at a median of four years. CONCLUSION: The Ross AVR can be performed with good mid-term results, including the pediatric age group. The potential for development of significant autograft insufficiency and homograft stenosis warrants annual follow up through the intermediate and late terms.     

Medium-term follow up of pulmonary autograft aortic valve replacement: technical advances and echocardiographic follow up

BACKGROUND AND AIM OF THE STUDY: The Ross procedure (aortic valve replacement (AVR) with pulmonary autograft and pulmonary homograft replacement of pulmonary valve) was developed as a durable aortic valve substitute that avoids the need for anticoagulation and provides young patients with a long-lasting aortic valve substitute. Our seven-year follow up echocardiography data are reviewed. METHODS: Between May 1993 and March 2000, 40 adult patients (28 males, 12 females; mean age 33.3 years) underwent the Ross procedure at the Brigham and Women's Hospital for congenital aortic stenosis (n = 6), aortic insufficiency (n = 17) and mixed disease (n = 17). All patients had aortic root replacement with the pulmonary autograft and had no regurgitation after operation. Postoperative evaluation was conducted by transthoracic echocardiography, office visit and/or telephone interview. NYHA functional class, aortic and pulmonary valve function and aortic root dimensions were evaluated. RESULTS: One patient died postoperatively as a result of a low output state related to global left ventricular dysfunction. Four patients (10%) developed pulmonary homograft stenosis with a peak gradient >40mmHg; and six developed mild pulmonary stenosis. One patient had aortic insufficiency seven years postoperatively that required valve replacement. Eight patients developed mild dilatation (>37 mm) of the neoaortic root, and five of these had aortic insufficiency. One patient required transplantation at 40 months for restrictive cardiomyopathy. CONCLUSION: The Ross procedure is an effective means of AVR that can be accomplished with low perioperative morbidity and mortality if certain technical modifications are carried out. In this series of 40 patients with mid-term follow up, a significant number developed moderate pulmonary trunk stenosis, though echo characterization demonstrated good valve function.     

Rest and exercise hemodynamics before and after valve replacement--a combined Doppler/catheter study

BACKGROUND: Hemodynamic improvement is a common finding following valve replacement. However, despite a normally functioning prosthesis and normal left ventricular ejection fraction, some patients may show an abnormal hemodynamic response to exercise. METHODS: In a combined catheter/Doppler study, rest and exercise hemodynamics were evaluated in 23 patients following aortic (n = 12) (Group 1) or mitral valve (n = 11) (Group 2) replacement and compared with preoperative findings. Patient selection was based on absence of coronary artery disease and left ventricular failure as shown by preoperative angiography. Cardiac output, pulmonary artery pressure, pulmonary capillary pressure, and pulmonary resistance were measured by right heart catheterization, whereas the gradient across the valve prosthesis was determined by Doppler echocardiography. Postoperative evaluation was done at rest and during exercise. The mean follow-up was 8.2 +/- 2.2 years in Group 1 and 4.2 +/- 1 years in Group 2. RESULTS: With exercise, there was a significant rise in cardiac output in both groups. In Group 1, mean pulmonary pressure/capillary pressure decreased from 24 +/- 9/18 +/- 9 mmHg preoperatively to 18 +/- 2/12 +/- 4 mmHg postoperatively (p < 0.05), and increased to 43 +/- 12/30 +/- 8 mmHg with exercise (p < 0.05). The corresponding values for Group 2 were 36 +/- 12/24 +/- 6 mmHg preoperatively, 24 +/- 7/17 +/- 6 mmHg postoperatively (p < 0.05), and 51 +/- 2/38 +/- 4 mmHg with exercise (p < 0.05). Pulmonary vascular resistance was 109 +/- 56 dyne.s.cm-5 preoperatively, 70 +/- 39 dyne.s.cm-5 postoperatively (p < 0.05), and 70 +/- 36 dyne.s.cm-5 with exercise in Group 1. The corresponding values for Group 2 were 241 +/- 155 dyne.s.cm-5, 116 +/- 39 dyne.s.cm-5 (p < 0.05), and 104 +/- 47 dyne.s.cm-5. There was a significant increase in the gradients across the valve prosthesis in both groups, showing a significant correlation between the gradient at rest and exercise. No correlation was found between valve prosthesis gradient and pulmonary pressures. CONCLUSION: Exercise-induced pulmonary hypertension and abnormal left ventricular filling pressures seem to be a frequent finding following aortic or mitral valve replacement. Both hemodynamic abnormalities seem not to be determined by obstruction to flow across the valve prosthesis and may be concealed, showing nearly normal values at rest but a pathologic response to physical stress.     

Intermediate-term results of Medtronic freestyle valve for right ventricular outflow tract reconstruction in the Ross procedure

BACKGROUND AND AIM OF THE STUDY: The Ross procedure has become the first choice for aortic valve replacement in children and young adults at many institutions. Since 1997, a lack of availability of homograft valves in Turkey has prompted the use of alternative substitutes for right ventricular outflow tract (RVOT) reconstruction during the Ross procedure. METHODS: Before April 2005, among 20 patients (age range: 14 months to 45 years) at the present authors' institution, the Ross procedure was performed in 14 and a Ross-Konno procedure in six. Sixteen patients underwent RVOT repair using alternative methods for homograft valve replacement. Fourteen patients received a Medtronic Freestyle valve and one patient a Medtronic Contegra bovine jugular vein conduit. An autologous RVOT repair was used in one patient. Ten of the Medtronic Freestyle valve patients were aged <16 years. In all patients who received a Medtronic Freestyle valve echocardiographic evaluations were conducted shortly after surgery and during follow up. RESULTS: There was no early mortality. One patient died from pneumonia after six months, and another (asymptomatic) patient died suddenly at 34 months after surgery. Before hospital discharge the mean peak pressure gradient across the Freestyle valve was 12.1 +/- 11.0 mmHg, and this increased to 24.1 +/- 20.0 mmHg after a mean follow up of 51.2 +/- 6.9 months (range: 6 to 101 months) (p <0.002). Mild pulmonary regurgitation was seen in two patients. One asymptomatic adult patient was reoperated on at another center because of a 60-mmHg echocardiographic peak gradient at four years postoperatively. CONCLUSION: Although long-term follow up is required to explain the durability of the Medtronic Freestyle valve, the present results show that the valve can be used with intermediate-term success in the Ross procedure - and even in children as an alternative - if homograft valves are not available.     

Feasibility of the ross procedure: its relationship with the bicuspid aortic valve

BACKGROUND AND AIM OF THE STUDY: The feasibility of the Ross procedure, and which patients benefit most from its performance, have not yet been fully established. The study aim was to analyze the relationship between the etiology of aortic valve disease, the feasibility of performing the Ross procedure, and late pulmonary autograft performance. METHODS: Between June 1995 and June 2001, 117 patients (77 males, 40 females; mean age 37+/-12 years) underwent the Ross procedure at the authors' institution. Of these patients, 53 (45.3%) had severe aortic stenosis, 53 (45.3%) had significant aortic insufficiency, four (3.4%) had active endocarditis, two (1.7%) had subaortic stenosis, and five (4.3%) had prosthesis dysfunction. Eighty-one patients (69%) had a bicuspid aortic valve. Pulmonary autograft dysfunction was defined as regurgitation grade > or =2, as registered by Doppler echocardiography. RESULTS: The Ross procedure was successful in 100 patients (85.5%); hospital mortality was 2.6% (n = 3). The procedure was not feasible in 17 patients (14.5%); of these, seven had bicuspid pulmonary valve, six had >3 mm multiple pulmonary valve fenestrations, three had severe pulmonary insufficiency, and one patient had dissection-related pulmonary valve injury. Twelve of 16 patients presenting with pulmonary valve defects had bicuspid aortic valve (p = 0.04). At six-year follow up, the probability of not requiring reoperation was 93% (confidence interval 86-100%). During follow up (30+/-14 months; range: 2-72 months), six patients presented with grade 2 pulmonary autograft insufficiency, three with grade 3, and two with grade 4. Six of the latter 11 patients (p = 0.03) had a history of bicuspid aortic valve with aortic regurgitation. Freedom from autograft dysfunction was 87% (confidence interval 82-92%). Patients with bicuspid aortic valve and aortic valve regurgitation had a higher tendency towards autograft dysfunction than those with bicuspid aortic valve and aortic stenosis (65% versus 100%, p = 0.004). CONCLUSION: The feasibility of performing the Ross procedure is high, unless there is presence of bicuspid aortic valve. Patients with bicuspid aortic valve and a history of aortic insufficiency tend to develop moderate autograft dysfunction during long-term follow up.     

Assessing options for the small aortic root

Valve selection for the small aortic root is a multifactorial process. Considerations include the effective orifice (EOA) of the implanted valve, annular size, body surface area (BSA), and valvular outflow tract of each patient. To decide if a valve is adequate for a patient, the valve EOA and patient BSA are used to calculate the indexed EOA (EOA/BSA). An indexed EOA <0.85 is associated with significant increases in mean systolic gradient with increase in cardiac output. The gradient remains low when indexed EOA is >0.85, leading to improved left ventricular mass reduction and decreased long-term risk of arrhythmias, congestive heart failure, and death. Biologic valves are usually used in patients aged over 65 years. Stented biologic valves tend to have a low EOA for their size. A 21-mm pericardial valve has an indexed EOA of 0.81 when implanted in a 1.6-m, 58-kg woman, and 0.69 in a 1.7-m, 72-kg man. Stentless valves (xenograft and homograft) have excellent EOAs and consequently very low gradients with good ventricular mass reduction. This allows for insertion of a larger valve, and results in more normal opening and flow dynamics. Hence, the best approach in over 65-year-old aortic valve patients when using a biologic valve is a stentless subcoronary implant. If this is not possible for anatomic reasons, a stented valve with an indexed EOA >0.85 is the best alternative. An option is root replacement with a xenograft or homograft, but the operative risk is significantly increased. The decision in younger patients (aged <65 years) is more complex. In-vivo EOAs for mechanical valves vary greatly; the St. Jude HP and Regent valves have consistently excellent EOAs. Recent results with the St. Jude Regent valve show gradients and left ventricular mass reduction close to those for stentless biologic valves. In a small aortic annulus, the decision must be made to use a more efficient valve (e.g. the Regent) or a biologic stentless valve, to perform annular enlargement (increasing surgical risk), or to tilt the stented valve to be supra-annular in the non-coronary cusp. The subvalvular outflow tract should not be ignored. Septal hypertrophy is not uncommon, and may increase the gradient across the outflow tract just below the valve. Finally, suture techniques (e.g. pledgetted versus interrupted simple sutures) can affect the long-term gradient. Pledgetted sutures can draw tissue underneath the valve and reduce the EOA. In conclusion, multiple factors must be evaluated when deciding which valve to use as a replacement in the small aortic root. These include patient age, lifestyle, pregnancy status, and drug compliance, as well as the indexed EOA of available prosthetic valves and the surgical procedure required for implant.