Bartonella henselae endocarditis of percutaneously implanted pulmonary valve: a case report

Percutaneous pulmonary valve implantation (PPVI) has revolutionized the management of right ventricular outflow tract dysfunction after repaired congenital heart disease. The technology is considered to be safe, with a relatively low complication rate. Infection is one of the described complications of PPVI, and to date five cases of culture-positive infective endocarditis of percutaneously implanted pulmonary valve have been reported worldwide. Herein is reported the first ever case of culture-negative endocarditis of a percutaneously implanted pulmonary valve, caused by Bartonella henselae, five years after implantation in a 15-year-old patient with a repaired truncus arteriosus.

Late aortic dilatation and regurgitation after Ross operation

The Ross operation, a procedure of replacement of the diseased aortic valve with an autologous pulmonary valve, has many advantages such as no need for anticoagulation therapy and similar valve function and growth potential as native valves. However secondary aortic disease has emerged as a significant complication and indication for reoperation. We report a 48-year-old woman who had Ross operation in 1997 for a damaged bicuspid aortic valve and severe aortic regurgitation due to subacute bacterial endocarditis complicated by aortic root abscess. In 2009, 12 years later, progressive severe aortic regurgitation with incomplete coaptation and mild dilatation of the aortic root was shown on echocardiography and contrasted CT, while the pulmonary homograft retained normal function. She subsequently underwent aortic valve replacement. Histopathological examination of the explanted neo-aortic valve and neo-arterial wall revealed pannus formation at the nodulus Arantii area of the three valve cusps, ventricularis, and arterialis. The amount of elastic fibres in the neo-aorta media was less than usual for an aorta of this patient's age but was similar to a pulmonary artery. The pathological findings were not different from other studies of specimens removed between 7 to 12 years after Ross operation. However, the pathophysiology and long-term implications of these findings remain debatable. Considering the anatomical and physiological changes induced by the procedure, separate mechanisms for aortic dilatation and regurgitation are worthy of consideration.

Long-term outcomes after autograft versus homograft aortic root replacement in adults with aortic valve disease: a randomised controlled trial

BACKGROUND

The ideal substitute for aortic valve replacement in patients with aortic valve disease is not known. Our hypothesis was that the regulatory and adaptive properties of a living valve substitute could improve the long-term outcomes in patients. We therefore compared these outcomes after autograft aortic root replacement (Ross procedure) versus homograft aortic root replacement in adults.

METHODS

Male and female patients (<69 years) requiring aortic valve surgery were randomly assigned in a one-to-one ratio to receive an autograft or a homograft aortic root replacement in one centre in the UK. The random allocation sequence was computer generated. Treatment was not masked. The primary endpoint was survival of patients at 10 years after surgery. This study is registered as an International Standard Randomised Controlled Trial, number ISRCTN03530985.

FINDINGS

228 patients were randomly assigned to receive an autograft or a homograft aortic root replacement. 12 patients were excluded because they were younger than 18 years; 108 in each group received the surgery they were assigned to and were analysed. There was one (<1%) perioperative death in the autograft group versus three (3%) in the homograft group (p=0.621). At 10 years, four patients died in the autograft group versus 15 in the homograft group. Actuarial survival at 10 years was 97% (SD 2) in the autograft group versus 83% (4) in the homograft group. Hazard ratio for death in the homograft group was 4.61 (95% CI 1.71-16.03; p=0.0060). Survival of patients in the autograft group was similar to that in an age-matched and sex-matched British population (96%).

INTERPRETATION

Our findings support the hypothesis that a living valve implanted in the aortic position can significantly improve the long-term outcomes in patients.

FUNDING

Funding Magdi Yacoub Institute.

Ross operation in a patient with juvenile rheumatoid arthritis

A 32-year-old woman with juvenile rheumatoid arthritis underwent a redo aortic valve replacement 7 years after a Ross procedure for severe aortic valve regurgitation. Interestingly, the cause of autograft failure was not related to the rheumatoid inflammation process.

Superior results following the Ross procedure in patients with congenital heart disease

BACKGROUND AND AIM OF THE STUDY

The Ross procedure is a versatile operation that can be applied for aortic valve replacement (AVR) in patients with congenital heart disease (CHD), including small infants and those with complex left ventricular outflow tract (LVOT) obstruction. Herein, the clinical outcome is reported following the Ross procedure in patients with CHD at the authors' institution.

METHODS

The medical records of patients who underwent the Ross procedure for CHD between 1991 and 2007 were reviewed. A competing-risks methodology was used to determine the time-related prevalence and associated factors for three mutually exclusive end states after the Ross procedure, namely death prior to subsequent cardiac reoperation, cardiac reoperation, and survival without subsequent reoperation.

RESULTS

A total of 151 patients (98 males, 53 females) was identified. The median age at the time of surgery was 8.6 years (range: 4 days to 33 years). Previously, 103 patients (68%) had undergone cardiac interventions, and 43 (28%) required LVOT enlargement (modified Ross-Konno procedure). A competing-risk analysis showed that, at 10 years after the Ross procedure, 8% of patients had died without subsequent reoperation, 26% underwent cardiac reoperation, and 66% remained alive without further reoperation. The 10-year freedom from autograft and homograft reoperation was 95% and 71%, respectively. Factors associated with early risk of mortality were age < 1 year and no prior surgical/percutaneous intervention at the time of the Ross procedure. Surgical factors associated with cardiac reoperation were concurrent cardiac surgery and the use of fresh homografts. There were no bleeding or thromboembolic complications, and the 15-year freedom from endocarditis was 95%. Ultimately, 99% of the survivors were in NYHA class I or II.

CONCLUSION

The Ross procedure remains the authors' procedure of choice for AVR in patients with CHD. Outcomes in infants aged < 1 year may improve with better patient selection and palliative surgical/percutaneous interventions prior to valve replacement. The late survival was excellent and valve-related complications were minimal. The high autograft longevity led to few patients requiring late reoperation for graft replacement.

Clinical experience with expanded use of the Ross procedure: a paradigm shift?

BACKGROUND AND AIM OF THE STUDY

The study aim was to evaluate the short-term survival and functional outcome after the Ross procedure, with expanded inclusion criteria.

METHODS

A total of 91 patients (21 females, 70 males; mean age 57.3 +/- 13.1 years; range: 0.1-74 years) underwent aortic valve replacement (AVR) with a Ross procedure at the authors' institution during the year 2007. The underlying valve diseases were stenosis in 60 patients, regurgitation in 17, and a mixed lesion in 14. Seven patients suffered from acute infective endocarditis, and in five patients the Ross operation was a reoperative procedure. Forty-four patients (48%) underwent surgery in association with concomitant procedures, which included predominantly coronary artery bypass surgery, mitral valve repair or replacement, or procedures of the ascending aorta.

RESULTS

The mean cardiopulmonary bypass and aortic cross-clamp times were 147 +/- 31 min (range: 87-246 min) and 124 +/- 26 min (range: 73-195 min), respectively. Hospital mortality was 2.2%. No patient died during the follow up period. The aortic gradient was decreased from 5.1 +/- 2 mmHg at discharge, to 3.2 +/- 1 mmHg during follow up (p < 0.05); at the same times, the mean gradient of the decellularized tissue-engineered pulmonary valve was 2.8 +/- 1 mmHg and 2.7 +/- 1 mmHg, respectively. An echocardiographic examination of neo-aortic valve competence at 12 months revealed no or trivial aortic valve regurgitation in 80 patients, and mild (grade 1+) regurgitation in nine patients. No patient required reoperation of the autograft during follow up. Two patients underwent reconstruction of the right ventricular outflow tract. At 12 months' follow up, all patients enjoyed normal social interactions, were in NYHA functional class I or II, and free from complications.

CONCLUSION

The Ross procedure can be offered as an alternative to standard prosthetic AVR with an excellent short-term outcome. The former inclusion/exclusion criteria for this procedure should be re-evaluated.

In vivo monitoring of function of autologous engineered pulmonary valve

OBJECTIVES

Clinical translation of tissue-engineered heart valves requires valve competency and lack of stenosis in the short and long term. Early studies of engineered valves showed promise, although lacked complete definition of valve function. Building on prior experiments, we sought to define the in vivo changes in structure and function of autologous engineered pulmonary valved conduits.

METHODS

Mesenchymal stem cells were isolated from neonatal sheep bone marrow and seeded onto a bioresorbable scaffold. After 4 weeks of culture, valved conduits were implanted. Valve function, cusp, and conduit dimensions were evaluated at implantation (echocardiography), at the experimental midpoint (magnetic resonance imaging), and at explant, at 1 day, and 1, 6, 12, or 20 weeks postoperatively (direct measurement, echocardiography). Histologic evaluation was performed.

RESULTS

Nineteen animals underwent autologous tissue-engineered valved conduit replacement. At implantation, valved conduit function was excellent; maximum transvalvular pressure gradient by Doppler echocardiography was 17 mm Hg; most valved conduits showed trivial pulmonary regurgitation. At 6 postoperative weeks, valve cusps appeared less mobile; pulmonary regurgitation was mild to moderate. At 12 weeks or more, valved conduit cusps were increasingly attenuated and regurgitant. Valved conduit diameter remained unchanged over 20 weeks. Dimensional measurements by magnetic resonance imaging correlated with direct measurement at explant.

CONCLUSIONS

We demonstrate autologous engineered tissue valved conduits that function well at implantation, with subsequent monitoring of dimensions and function in real time by magnetic resonance imaging. In vivo valves undergo structural and functional remodeling without stenosis, but with worsening pulmonary regurgitation after 6 weeks. Insights into mechanisms of in vivo remodeling are valuable for future iterations of engineered heart valves.

[Ross operation in Chile]

BACKGROUND

Donald Ross introduced the pulmonary autograft for aortic valve replacement with reconstruction of the right ventricular outflow tract with a homograft. Despite its advantages over conventional valve prostheses, the Ross Operation is performed in a minority of patients who need an aortic valve replacement throughout the world.

AIM

To report the operative and long term results of a series of patients subjected to Ross operation in Chile.

PATIENTS AND METHODS

Between 1996 and 2006, 131 patients aged 35+/-11 years (62% males) were subjected to an aortic root replacement with a pulmonary autograft and reconstruction of the right ventricular outflow tract with a pulmonary homograft. Seventy percent had congenital valve disease. Associated procedures were done in 39%. Patients were followed for a mean of 56+/-30 months.

RESULTS

Operative mortality was 2.3%. Two patients had the autografts replaced intraoperatively because of tears in the proximal suture line and one within a month of the operation after suffering autograft endocarditis. At last follow up all patients are in functional class 1 or 2. Autograft reoperations were done in two patients who developed dilation with valve regurgitation (both had aortic regurgitation as primary indication for aortic valve replacement). Three patients required reoperation for pulmonary homograft dysfunction. Another three patients had uneventful pregnancies with normal newborns. Actuarial freedom from any reoperation at 10 years is 93%.

CONCLUSIONS

The Ross Operation has low operative morbidity and mortality with excellent long term results. Reoperations have been rare within 10 years of follow up both for the autograft or the homograft.

Preservation of the pulmonary autograft after failure of the Ross procedure

OBJECTIVE

Failure of the pulmonary autograft following the Ross Procedure is mainly due to dilatation and/or cusp prolapse causing insufficiency. We analysed the result of pulmonary autograft valve sparing and repair, using techniques developed for native aortic root and valve.

METHODS

Of a total of 275 patients who underwent Ross operation between 1991 and 2009, 31 needed autograft re-operation. Of the 28 patients re-operated in our centre, 26 (93%) had autograft valve preservation and they represent the study cohort. At the initial Ross procedure, root remplacement technique was performed in 20 patients and autograft inclusion technique was performed in 6. Mean redo interval was 9.3 + or - 3.5 years and mean age at redo was 44 + or - 13 years. Indications for re-operations were neo-aorta dilatation (n=12; 46%), autograft insufficiency (n=4; 15%) and dilatation with autograft insufficiency (n=10; 40%). Neo-aorta dilatation was repaired using valve-sparing root replacement (n=12, 46%) or ascending aorta replacement (n=10; 40%). Cusp prolapse was repaired by commissural re-suspension (n=1), free margin plication (n=10) or re-suspension with polytetrafluoroethylene (PTFE; n=6). Cusp repair was performed in isolation (n=4) or in association with sparing (n=5) or ascending aorta replacement (n=4).

RESULTS

There was no in-hospital mortality. Two patients having undergone isolated cusp repair needed valve replacement for recurrent insufficiency after 5 days and 8 years postoperatively. At follow-up (100% complete, median: 27 months) all patients were alive, in New York Heart Association (NYHA) class I (n=22; 84%) or II (n=4; 16%). No autograft regurgitation was present in nine patients (five sparing and four ascending aorta replacement); grade I insufficiency was present in 11 (six sparing and five ascending aorta replacement), grade 2 in two (one sparing and one isolated cusp repair) and grade 3 in two (one ascending aorta replacement and one isolated cusp repair). At 3 years, overall freedom from autograft insufficiency > or = grade 3 was 80%.

CONCLUSION

Preservation of the pulmonary autograft valve can be safely performed in selected patients. At midterm, repair of neo-aorta dilatation using valve-sparing root replacement or ascending aorta replacement showed acceptable results. In contrast, results of cusp repair for isolated autograft insufficiency were unsatisfactory.

Anti-HLA antibodies and pulmonary valve allograft function after the Ross procedure

BACKGROUND AND AIM OF THE STUDY

Rejection is a plausible cause of failure of allograft valves, but has not been demonstrated unequivocally in humans. A cross-sectional study has been conducted on the frequency of anti-human leukocyte antigen (HLA) antibodies in order to identify any correlation with allograft function in adult patients, following the Ross procedure.

METHODS

Anti-HLA antibodies were determined during regular follow up (median 1.1 years postoperatively) in a random sample of 197 patients (151 males, 46 females; mean age 46 +/- 13 years). Panel-reactive antibodies (PRA) were determined by cytotoxicity testing; anti-HLA class 2 antibodies (HLA2AB) were determined by ELISA in a subgroup of 94 patients. Echocardiographic examinations were performed during the first visit and at a median of 6.8 years postoperatively.

RESULTS

The prevalence of positive antibody tests was 47% for PRA and 52% for HLA2AB. A slight deterioration of allograft valve function occurred between the two examinations (median maximal pressure gradient increased from 9 mmHg to 13 mmHg, p < 0.001; median degree of regurgitation increased from zero to trivial, p = 0.020). The degree of regurgitation was slightly, but significantly, higher in PRA-positive patients at both examinations (p = 0.008 and p = 0.038). No relationship was observed between PRA status and pressure gradients, nor between HLA2AB status and allograft valve function. Neither were any other risk factors for allograft valve deterioration identified.

CONCLUSION

Subtle, clinically irrelevant and temporally stable differences with regard to regurgitation across the allograft were observed between PRA-positive and -negative patients. These findings neither proved nor disproved rejection, but rather suggested that a slow deterioration of allograft valve function was complex, and most likely multifactorial.

Ross and Ross-Konno procedures in infants, children and adolescents: a 13-year experience

BACKGROUND AND AIM OF THE STUDY

Due to hemodynamic performance and potential for growth of the pulmonary autograft, the Ross operation is considered to be the surgery of choice for irreparable aortic valve disease in pediatric patients. The study aim was to analyze the long-term clinical and echocardiographic results of the Ross operation.

METHODS

Between February 1993 and July 2006, 55 consecutive patients (mean age 10.0 +/- 6.2 years; range: 3 months to 18 years) underwent eithera Ross operation (n=46) or a Ross-Konno procedure (n=9). The underlying left ventricular outflow tract pathology was mainly congenital (n=47). Among patients, 23 (42%) had undergone a previous aortic valve procedure. Concomitant procedures were performed in 16 patients (29%). The Ross operation was performed as a root replacement in all cases; the mean cross-clamp time was 132 min (range: 100-188 min). The autograft diameter was indexed to the body surface area and compared to normal values. The mean follow up was 5.5 +/- 3.8 years, and was 100% complete.

RESULTS

There was one early death (2%) and two late deaths (4%). The actuarial patient survival was 93% at 10 years. None of the patients developed moderate or severe autograft regurgitation. All measured maximal root diameters were above the 90th percentile of normal aortic diameter, without correlation to autograft regurgitation. Five patients (9%) had a mean homograft gradient > or = 40 mmHg, and two (4%) were reoperated on. The freedom from reoperation for homograft degeneration was 91% at 10 years.

CONCLUSION

Autograft regurgitation after the Ross and Ross-Konno procedures is uncommon, and the risk of homograft degeneration appears low. Autograft dilatation is common but does not correlate with autograft regurgitation. When considering long-term freedom from autograft and homograft degeneration, the results of the present study confirm the Ross operation as the surgery of choice for irreparable aortic valve disease in infants, children and young adults.

Thirteen years' experience with the Ross Operation

BACKGROUND AND AIM OF THE STUDY

The study aim was to evaluate 13 years' results of the Ross operation, with special attention paid to the late function of the pulmonary autograft (PA) and the right ventricular outflow tract (RVOT) allograft, in an attempt to identify risk factors that might significantly influence their late performance.

METHODS

Between May 1995 and March 2006, a total of 272 patients (mean age 30 +/- 11 years) was submitted to a Ross operation at the authors' institution. The most prevalent etiology was rheumatic disease (47%). The PA was implanted as a root replacement in 236 cases, and as an intraluminal cylinder in 36. The RVOT was reconstructed with a cryopreserved allograft in conventional fashion (n=142), with a proximal extension of the allograft with pericardium (n=46), with an allograft decellularized with deoxycholic acid (n=39), or an allograft decellularized with sodium dodecylsulfate (SDS) (n=44). The mean follow up was 67 months (range: 1-153 months: the total follow up was 1,525 patient-years.

RESULTS

Hospital mortality was 2.9% and late survival 93% at 12 years. There were two episodes of cerebral thromboembolism, and six patients developed bacterial endocarditis. Sixteen patients required reoperation for problems involving the PA and/or the RVOT allograft, progression of rheumatic mitral valve disease and iatrogenic coronary insufficiency. After 12 years, 97% and 95% of patients were free from reoperation with the PA and allograft, respectively. Over time, the PA showed increasing dimensions, and 10 patients had a diameter >45 mm. Univariate analysis revealed degenerative disease and aortic annulus >25 mm as significant risk factors for late PA dilatation. Female gender and bicuspid aortic valve were borderline factors for this type of complication. Another 14 patients had late moderate PA insufficiency, and this was correlated with a preoperative diagnosis of aortic insufficiency. Reconstruction of the RVOT with allografts decellularized with SDS were associated with lower gradients at late follow up.

CONCLUSION

Late results with the Ross operation were associated with excellent long-term survival and a low incidence of reoperations up to 13 years. Due to late PA dilatation and/or progressive valvar insufficiency, some reoperations may be expected with a longer follow up. For the RVOT reconstruction, the use of decellularized allografts with SDS may prove to be a good alternative to RVOT reconstruction.

Effect of pulmonary autograft transplantation in the surgical treatment of aortic valve disease

BACKGROUND

Aortic root replacement with pulmonary autograft (Ross procedure) has the advantages of good haemodynamics and growth potential without the need for anticoagulation. In this study, we reviewed our experience of the Ross procedure for patients with aortic valve disease.

METHODS

From October 1994 to January 2005, 42 Ross procedures were performed in our centre. There were 30 males and 12 females. The mean age was 28 +/- 15 years (range, 5-56 years). Congenital heart disease (CHD) with aortic valve stenosis (AS) and/or aortic valve insufficiency (AI) in 40 cases including one associated with ventricular septal defect (VSD), degenerated aortic valve disease with AS in 1 and subacutive bacterial endocarditis (SBE) with AI in 1 were studied. The diagnosis was made by ultracardiography (UCG) in all patients. The mean aortic valve annulus diameter (AVD) was (2.45 +/- 0.31) cm and pulmonary valve annulus diameter (MPVD) was (2.34 +/- 0.21) cm. All patients had normal pulmonary valves. The New York Heart Association (NYHA) function class was II in 36 cases and III in 6 cases. The operation was performed under moderate hypothermic cardiopulmonary bypass (CPB) with aortic root replacement using pulmonary autograft and pulmonary valve replacement with a homograft.

RESULTS

There was no early hospital mortality. Postoperative UCG showed normal aortic valve function in all our patients. The mean gradient across the aortic valve was (6.11 +/- 0.12) mmHg. The left ventricular diastole diameter (LVDD) decreased significantly from (62 +/- 5) mm to (56 +/- 3) mm (P < 0.001). The mean postoperative left ventricular ejective fraction (LVEF) was 0.49 +/- 0.23. All patients were in NYHA class I-II. Follow-up was completed in 38 cases for a mean period of 3.2 years (range 1-10 years). All survivors were in NYHA class I with normal neo-aortic and pulmonary valve function. One patient died after secondary operation due to homograft fungal endocarditis 1 year after the Ross procedure. The cause of death was uncontrolled bleeding. Another patient suffered from cardiogenic shock and was on extracorporeal membrane oxygenation (ECMO) for 10 days postoperatively. This patient was subsequently self-discharged from hospital due to financial issues and he was excluded from follow-up.

CONCLUSION

The Ross procedure is an excellent technique to treat aortic valve disease. Our data show that it can be performed safely with good early and mid-term clinical outcomes.

Early outcome after surgery for active native and prosthetic aortic valve endocarditis

BACKGROUND AND AIM OF THE STUDY

Today, the in-hospital mortality of patients treated surgically for active aortic native and prosthetic valve endocarditis remains high. The study aim was to identify the preoperative and intraoperative predictors of early outcome.

METHODS

Between January 2004 and December 2006, 75 patients (57 males, 18 females; mean age 61.6 +/- 14.1 years) underwent surgery for active native valve (NVE) or prosthetic aortic valve endocarditis (PVE).

RESULTS

Active aortic NVE was present in 49 patients (65.3%), and PVE in 26 (34.7%). Staphylococcus species were the most common infecting microorganisms in both groups, while 20 cases (26.7%) were culture-negative. Except for significantly higher preoperative renal failure (RF) in patients with PVE (p = 0.01), the clinical characteristics were equally distributed. Four patient subsets were identified based on the extent of the infectious process: (i) locally controlled NVE (38.7%); (ii) locally uncontrolled NVE (26.7%); (iii) locally controlled PVE (14.6%); and (iv) locally uncontrolled PVE (20%). Aortic valve replacement (AVR) was performed with a stentless bioprosthesis in 53 cases (70.7%), a mechanical prosthesis in eight (10.6%), and a Ross procedure in 14 (18.7%). Concomitant active mitral valve endocarditis was treated in 17 patients (22.7%). Associated procedures were performed in 14 cases (18.7%). The in-hospital mortality was 24% (n = 18). Female gender (p = 0.0147), preoperative septic or cardiogenic shock (p = 0.0275) and previous embolic events (p = 0.0129) were identified as independent predictors for in-hospital mortality. Eight late deaths occurred; the estimated overall actuarial survival was 66.6 +/- 5.6% at 12 months and 60.7 +/- 6.5% at 24 months. On Cox multiple regression, age > 70 years (p = 0.0113), preoperative RF (p = 0.0015) and mitral valve surgery due to concomitant infective endocarditis (p = 0.0363) were significant adverse predictors of late death.

CONCLUSION

Surgery for active aortic valve infective endocarditis is associated with high operative mortality and morbidity. Failure of antibiotic therapy causing septic or cardiogenic shock and delayed referral to surgery may have a detrimental effect on early outcome. Surgical eradication of cardiac infections should always be associated with the treatment of extracardiac septic foci, which could maintain a septic state and adversely influence early outcome. Adhesion to surgical guidelines, together with a multidisciplinary approach, may have a major impact on the early prognosis of these high-risk patients.

Aortic valve replacement: ten-year follow up of the Ross procedure

BACKGROUND AND AIM OF THE STUDY

The study aim was to assess the long-term results of the Ross procedure in the treatment of aortic valve disease.

METHODS

Between July 1995 and May 2006, a total of 165 patients (131 males, 34 females; mean age 39 +/- 13 years) underwent the Ross procedure using the freestanding root technique. Both, clinical and echocardiographic follow ups were conducted, with valve-associated events (death, endocarditis, thromboembolism, reoperation, valvular dysfunction) being analyzed using Kaplan-Meier curves. Log-rank tests, chi-square tests and the Cox model were used for variable analysis.

RESULTS

The mean preoperative left ventricular ejection fraction was 55 +/- 12%. Surgery was indicated for aortic stenosis (54%) or aortic insufficiency (46%). The aortic valve was bicuspid in 125 patients, while in four patients surgery was indicated in the setting of active infective endocarditis, and in six for prosthetic dysfunction. The in-hospital mortality was 2.5% (n = 4). Survival at one and 10 years was 97% (95% CI, 93-99) and 94.8% (95% CI, 89-98), respectively. Freedom from endocarditis at 10 years was 95% (95% CI, 84-98), and from valve-related events was 95% (95% CI, 90-98) and 88% (95% CI, 75-94) at one and 10 years, respectively. Four patients required reoperation (one case of recurrent mitral regurgitation after previous mitral valve repair; three cases of autograft dysfunction and disease of other valves). Based on this experience, and during the follow up period, the presence of aortic regurgitation as a baseline aortic lesion was not associated with any need for reoperation.

CONCLUSION

As a surgical technique, the Ross procedure has a low event rate at 10 years after surgery, and may be considered a valid alternative for the treatment of aortic valve disease.

[Freestyle valve for right ventricular reconstruction in Ross operation; report of a case]

A 28-year-old man with active aortic valve endocarditis underwent emergency surgery. Because he had progressive congestive heart failure and uncontrolled infection. Aortic root replacement for Ross procedure was required because of complete debridment of infective tissue. His operation were performed under extracorporeal circulation and moderate hypothermia, the operation procedure was following, (1) taking off auto-pulmonary artery valve, (2) removing dysfunctional aortic valve and auto-transplantation of pulmonary valve on aortic root, (3) putting a pulmonary Freestyle Aortic Valve to rebuild right ventricular outflow tract. Follow-up showed heart function was in class I (New York Heart Association) , aortic and pulmonary valve function was very well. Streptococcus milleri group was isolated from his blood and infectious aortic valve postoperatively. We believed that a Ross operation with Freestyle Aortic Valve is more resistant to infection, therefore, it might be an option for infective endocarditis with aortic valve endocarditis.

Fifty-two months' mean follow up of decellularized SynerGraft-treated pulmonary valve allografts

BACKGROUND AND AIM OF THE STUDY

It has been reported previously that the use of a decellularized pulmonary allograft (SynerGraft; CryoLife Inc.) for right ventricular outflow tract reconstruction in adults is associated with reduced immunization. The implantation appeared to be safe, but was not associated with any detectable clinical or echocardiographic advantage. The study aim was to follow further the outcome of SynerGraft patients.

METHODS

Twenty-three adult patients (19 males, four females) each received a SynerGraft-allograft during a Ross procedure. A further 49 patients (37 males, 12 females) who underwent a Ross procedure using a conventional pulmonary allograft during the same period served as controls. Follow up examinations using transthoracic echocardiography in standard views was performed on a regular basis. The latest follow up was performed after a mean of 52 months.

RESULTS

Directly after implantation, there were no echocardiographic differences between the two groups, but with time the pressure gradients increased significantly (p <0.001) in both groups. At the latest follow up, pressure gradients were slightly higher across the SynerGraft-allograft valves than across conventional allografts (Pmax 18.2 +/- 9.0 versus 14.0 +/- 6.9 mmHg, respectively; p = 0.049). On regression analysis (considering pre- and intraoperative variables), 'SynerGraft-allograft' was the only variable predicting the increase in pressure gradient from its postoperative value to that at follow up. However, no clinical differences were observed between the groups.

CONCLUSION

The present results relate to the longest follow up on decellularized pulmonary SynerGraft-allografts conducted to date. No reoperations were required after a mean follow up of 52 months, and the echocardiographic results were stable after the first postoperative year. Based on these data, the use of pulmonary SynerGraft-allograft valves in adults appears not to provide any advantage over conventional allografts, although further follow up is warranted before any final judgment is made regarding this new technology.

Prosthetic heart valves: Types and echocardiographic evaluation

In the last five decades multiple different models of prosthetic valves have been developed. The purpose of this article is to provide a comprehensive source of information for the types and the echocardiographic evaluation of the prosthetic heart valves.

Analysis of 92 mitral pulmonary autograft replacement (Ross II) operations

OBJECTIVE

The study objective was to find a mitral valve substitute that does not require lifelong anticoagulation and is not affected by tissue degeneration in the long term.

METHODS

Between July 14, 1997, and August 8, 2004, a total of 92 patients with irreparable mitral valve disease underwent mitral valve replacement with the pulmonary autograft encased within a Dacron tubing for support. In 4 patients, the autograft had to be sacrificed at the initial operation. Of the remaining 88 patients, 62 were female, and the age ranged from 4 to 64 years (mean 39 years). Eighty-six patients had rheumatic mitral disease, and 2 patients had congenital mitral disease.

RESULTS

Operative transesophageal echocardiography initially showed adequate valve characteristics (mean valve area 2.8 cm2, mean gradient 3.9 mm Hg, no significant regurgitation) in all 88 patients. Operative mortality was 4.6%, and late mortality definitely related to the operation was 7.9%. Four patients were lost to follow-up; the mean follow-up was 60 months. Progressive regurgitation and stenosis developed in 9 patients over 2 to 5 years, 4 of whom had their grafts explanted. The autograft was explanted in 1 patient because of endocarditis. Mild pulmonic stenosis developed in 3 patients, and critical pulmonic stenosis developed in 1 patient. At 5 years follow-up, freedom from degeneration was 93.4%, freedom from reoperation was 94.2%, and freedom from all death was 86.0%.

CONCLUSION

Although the Ross II operation is difficult and harbors significant risk, it remains an option for patients with irreparable mitral disease who have a long life expectancy and who cannot be placed on lifelong anticoagulation.

Are heart valves from donors over 65 years of age morphologically suitable for transplantation?

Since there is no upper age limit for general organ donation, unlike heart valve donation, and since a quarter of all organ donors are 65 years and older, we examined whether the heart valves from these donors are suitable as allografts. In the period 1999-2004 the aortic valve and pulmonary valve of 100 organ donors above 65 years of age were examined to establish whether they would have been suitable as valve grafts. To compare the valve grafts above and below the age limit of 65 years, we used data on the aortic and pulmonary valves of 380 organ donors below the age limit in the same time period. Examination of the 200 heart valves showed that - just like valves from donors below the age limit - 100 of them would have met the medical quality standards for transplantation, which discriminate among optimal, suitable and unsuitable tissue morphology. The morphological suitability of the aortic valves decreases rapidly during the 4th decade of life and near to the age limit only 6% of them are accepted as grafts. The rate of potentially acceptable aortic valve grafts from organ donors aged over 65 years of 15% is also small. By contrast, the pulmonary valves are not affected by age-related tissue changes that might reduce their transplantability. The predominant majority (85%) of potential pulmonary valve grafts from organ donors over 65 years of age fulfilled the acceptance criteria, half of them (48%) even showing good tissue quality. In light of these results the age limit was raised to 70 years in 2005.

Mid-Term Clinical Results Using a Tissue-Engineered Pulmonary Valve to Reconstruct the Right Ventricular Outflow Tract During the Ross Procedure

BACKGROUND

The Ross procedure is mainly limited by the durability of the valve prostheses used to reconstruct the right ventricular outflow tract. This study was performed to collect prospective safety and effectiveness data of the Ross procedure using a tissue-engineered heart valve to reconstruct the right ventricular outflow tract.

METHODS

Between May 2000 and February 2003, 23 patients received tissue-engineered heart valves. Two to four weeks before the Ross operation, a piece of forearm or saphenous vein was harvested to isolate, characterize, and expand endothelial cells. A pulmonary allograft (n = 11) or xenograft (n = 12) was decellularized, coated with fibronectin, and seeded with autologous vascular endothelial cells, using a specially developed bioreactor. Follow-up was performed by clinical evaluation, transthoracic echocardiography, magnetic resonance imaging, and multislice computed tomography.

RESULTS

The patient mean age was 44.0 +/- 13.7 years. Cell seeding density was 1.1 x 10(5) +/- 0.5 x 10(5) cells/cm2, with a viability of 90.2% +/- 8.9%. All patients survived the operation. One patient died during follow-up, and 1 patient required reoperation. All surviving patients are currently in New York Heart Association functional class I. Transthoracic echocardiographic evaluation of the tissue-engineered heart valve showed a mean flow velocity of 0.9 +/- 0.4 m/s at 5 years. Multislice computed tomography showed no calcification up to 5 years postoperatively.

CONCLUSIONS

Tissue-engineered heart valves showed excellent hemodynamic performance during mid-term follow-up. Decellularization of heart valves and seeding with autologous vascular endothelial cells may prevent tissue degeneration and improve valve durability.

Long-term morphological changes in a cryopreserved pulmonary valve homograft

Pulmonary homografts (PHs) are frequently used to replace the native pulmonary valve in the Ross procedure, and in the reconstruction of the right ventricular outflow tract. The case of a 25-year-old man whose PH was replaced 12 years after undergoing the Ross procedure is reported. The clinical cause of the PH failure was stenosis. Morphological studies showed cusp tissue degeneration with tears and calcification, as well as pannus growth on the flow and nonflow surfaces of the cusps and the pulmonary artery graft. The durability of this PH was likely due to a combination of low pressure on the right side of the heart and the patient's age at surgery.

Surgical strategy for the bicuspid aortic valve: tricuspidization with cusp extension versus pulmonary autograft

OBJECTIVE

The congenitally bicuspid aortic valve is the most common etiologic factor associated with clinically significant aortic stenosis and/or regurgitation in pediatric patients. Beyond infancy, surgical intervention typically involves valve repair with cusp thinning and commissurotomy or valve replacement, primarily with pulmonary autograft in the current era. An aortic valve repair technique using tricuspidization with cusp extension was introduced in 1999. This study compares the midterm clinical outcome in patients undergoing valve repair by tricuspidization with cusp extension with those receiving a pulmonary autograft (Ross).

METHODS

A retrospective study was performed on all consecutive patients with symptomatic bicuspid aortic valve disease who underwent tricuspidization with cusp extension or a Ross procedure between 1999 and 2005. In both groups, all patients were at least 1 year of age at time of the operation.

RESULTS

During this period, 21 children (median age 12.6 years, range 2.6-18 years) underwent tricuspidization with cusp extension (TCE group) and 25 children (median age 10.2 years, range 11.5 months-20.1 years) underwent the Ross procedure. Prior balloon valvuloplasty was performed in 5 (24%) of the children in the TCE group and 16 (64%) of the children in the Ross group. Prior surgical commissurotomy was performed in 4 (19%) TCE patients and in 9 (36%) Ross patients. During a median follow-up period of 36.4 months (range 2.5 months-7.4 years), 2 (10%) patients in the TCE group required valve-preserving early revision of the repair, 2 (10%) TCE patients required subsequent aortic valve replacement at 16 and 33 months, 1 (4%) Ross patient required subsequent valve repair at 5 years, and 1 (4%) Ross patient underwent cardiac transplantation at 46 months. At 36 months, the actuarial freedom from reintervention on the aortic valve or autograft was 90% in the TCE group, with 11 patients at risk, and 100% in Ross patients, with 13 patients at risk (P = .39); the freedom from moderate valve dysfunction or reintervention was 66% for TCE patients and 95% for Ross patients (P = .07). There were no deaths, and all but 1 Ross patient remain in New York Heart Association class I.

CONCLUSIONS

Reintervention rates in patients undergoing tricuspidization with cusp extension or a primary Ross procedure are similar. Valve performance in the TCE group is satisfactory at midterm follow-up, but the Ross repair appears to provide greater stability of valve function. These results suggest that repair with valve tricuspidization and cusp extension provides reliable palliation of the symptomatic bicuspid aortic valve.

In-vivo repopularization of a tissue-engineered heart valve in a human subject

A 63-year-old male with a massively calcified aortic valve showed an active lifestyle. Therefore, valve replacement was completed using the Ross procedure. During postoperative echocardiographic control, a ventricular septal defect was noted which was closed surgically. During this reoperation, a biopsy sample was taken from the wall of the tissue-engineered heart valve which was used to reconstruct the right ventricular outflow tract. A persistent monolayer of endothelial cells and host recellularization of the deeper layer was demonstrated histologically. The postoperative course was uneventful, and the patient rapidly recovered. After six years, he remains in excellent health.

The Ross operation for aortic valve disease: previous sternotomy results in improved long-term outcome

BACKGROUND AND AIM OF THE STUDY

Progressive pulmonary autograft dilatation and failure following a Ross operation continues to be of major concern. It is hypothesized that the pulmonary autograft may perform better over the longer follow up period if the Ross operation is performed as a reoperation rather than a primary operation. The basis for this hypothesis is that the epicardial and mediastinal fibrosis encountered at reoperation may inadvertently provide additional support for the pulmonary autograft during the follow up period.

METHODS

To test this hypothesis, 281 patients (mean age 24 +/- 9 years) who underwent a Ross operation over a 16-year period were retrospectively analyzed. The patient population was divided into two subgroups in whom the Ross operation was performed: (i) as the first cardiac operation, through a sternotomy incision (primary-Ross; n = 180); and (ii) after the patient had undergone a previous sternotomy (prior-sternotomy; n = 101). A recent follow up examination was achieved in 93% of patients.

RESULTS

Early and overall mortality was 2.1% and 6.4%, respectively, and there was no significant difference between the subgroups. At 12-year follow up, freedom from reoperation on the autograft, or valve-related death was 87 +/- 6% versus 71 +/- 9% in favor of the prior-sternotomy subgroup (p = 0.06). At 12-year follow up, freedom from valve-related death, or reoperation on the pulmonary autograft, or severe aortic regurgitation was 87 +/- 5% versus 71 +/- 7% (p = 0.03) in favor of the prior-sternotomy subgroup.

CONCLUSION

The results of a preliminary analysis suggest that additional benefit is accrued when the Ross operation is performed during re-sternotomy. This should encourage surgeons to attempt repair of the aortic valve during the initial surgery, with the knowledge that - if needed - the Ross operation can be performed safely at later surgery, and with possible additional benefit to the patient during the follow up period.

Outcome of pregnancy in women after pulmonary autograft valve replacement for congenital aortic valve disease

BACKGROUND AND AIM OF THE STUDY

The pulmonary autograft has been recommended as the valve of choice for aortic valve replacement (AVR) in young women contemplating pregnancy. However, current information on maternal and perinatal outcome of pregnancy in women with pulmonary autograft valve replacement is limited.

METHODS

Using a nationwide Dutch registry (CONCOR) and a local Belgian tertiary care center database, 17 women (age range: 18 to 45 years) with pulmonary autograft valve replacement were enrolled into the study. Twelve pregnancies were observed among five different women, including one miscarriage and one elective abortion.

RESULTS

Clinically significant (non-)cardiac complications were documented in two of 10 completed pregnancies. Complications included: (i) placental abruption necessitating Cesarean delivery at 29 weeks' gestation, further complicated by postpartum hemorrhage; and (ii) preterm premature rupture of the membranes resulting in premature delivery at 29 weeks' gestation with postpartum demise of the immature born child. Two women reported primary female infertility, but both became pregnant after hormonal substitution therapy. Four women reported irregularities of their natural menstrual cycle (menorrhagia, dysmenorrhea, polymenorrhea, oligomenorrhea, or amenorrhea).

CONCLUSION

Successful pregnancy in women with pulmonary autograft valve replacement is possible, although serious and clinically significant events occurred during gestation. Infertility and menstrual cycle disorders appear to be more prevalent.

The Ross Procedure: Clinical and Echocardiographic Follow-Up in 219 Consecutive Patients

BACKGROUND

The replacement of the diseased aortic valve with a pulmonary autograft has been shown to provide excellent hemodynamic results and to be associated with low morbidity and mortality rates.

METHODS

From 1991 to 2005, 219 patients undergoing the Ross operation were identified. All patients underwent transthoracic echocardiography at discharge and were scheduled for a yearly study thereafter. The echocardiographic study consisted of a morphologic analysis of the pulmonary autograft with measurement of end-systolic diameters at three levels: annulus, sinuses of Valsalva, and origin of the ascending aorta 2 cm above the sinotubular junction. The dynamic analysis evaluated the function of the aortic autograft and the pulmonary homograft. Maximal and mean aortic and pulmonary transvalvular pressure gradients were investigated.

RESULTS

The 30-day mortality was 1.8% (n = 4). Cardiac deaths were not related to the autograft. The 10-year actuarial survival was 95.7% +/- 2.1%. Six patients (2.8%) had grade 2 autograft valve regurgitation. No grade 3 or 4 pulmonary regurgitation was identified. At their most recent follow-up, 28 patients (13.1%) had grade 1 insufficiency of the pulmonary homograft, and 10 patients (4.6%) had a peak transvalvular gradient of 17.9 +/- 10.2 mm Hg.

CONCLUSIONS

Our current experience suggests that replacement of the aortic root with a pulmonary autograft can be safely performed in infants, children, and adults and is associated with low mortality and morbidity rates. It constitutes an elegant alternative to the use of prosthetic valves in the treatment of aortic valve diseases.

What is the proper place of the ross procedure in our modern armamentarium?

Despite nearly four decades of experience, the role of pulmonary valve autotransplantation (Ross procedure) in the treatment of aortic valve disease in adults and children continues to evolve and remains controversial. As the picture of late results has unfolded, alternating waves of enthusiasm and caution have characterized its use and have led to ongoing refinements in indications and operative technique. At present, it is seen as indispensable in the treatment of aortic valve disease in infants and small children (for whom no satisfactory replacement alternative exists and for whom growth is essential), attractive for adolescents and young adults who wish to avoid anticoagulants because of childbirth and lifestyle considerations, a reasonable option for selected adults who desire biologic solutions with potentially better durability than conventional bioprostheses, and contraindicated for the elderly and those with connective tissue disorders. Young patients with bicuspid aortic valve are the most common potential recipients, but also the most controversial, because of the risk of autograft dilatation. Optimal matching of prosthesis to patient is a clinical challenge for all caretakers involved in the treatment of valvular heart disease; this review provides guidelines to identify those patients who will benefit most from the Ross procedure, and those for whom it is inadvisable.

Predicting outcome of pulmonary valve replacement in adult tetralogy of Fallot patients

BACKGROUND

Predicting changes in right ventricular (RV) size and function after pulmonary valve replacement (PVR) is important for timely reintervention in adult tetralogy of Fallot patients.

METHODS

We analyzed the influence of pulmonary regurgitation severity and RV size and function before PVR on the outcome of RV size and function after PVR in 27 adult Fallot patients who had cardiac magnetic resonance imaging before and after PVR. RV dimensions were indexed for body surface area.

RESULTS

Pulmonary regurgitation (48% +/- 11% of RV stroke volume) was not related to RV dimensions and function before PVR. Moreover, severity of pulmonary regurgitation did not influence changes in RV dimensions after PVR. The indexed RV end-systolic volume before PVR (mean, 98 mL/m2; range, 52 to 235 mL/m2) best predicted the indexed RV end-systolic volume after PVR (mean, 59 mL/m2; range, 24 to 132 mL/m2, r = 0.78, p < 0.001) and the indexed RV end-diastolic volume after PVR (mean, 107 mL/m2; range, 70 to 170 mL/m2, r = 0.73, p < 0.001). Baseline RV ejection fraction corrected for valvular insufficiencies and shunting (21% +/- 7%) best predicted the RV ejection fraction after PVR (43% +/- 10%, r = 0.77, p < 0.001).

CONCLUSIONS

Timing of PVR should be based on indexed RV end-systolic volume and corrected RV ejection fraction rather than on severity of pulmonary regurgitation.

Chronic type A dissection in a pulmonary autograft

A 37-year-old patient presented with severe aortic valve insufficiency due to massive dilatation of the neo-aortic root (77 mm diameter) 14 years after a Ross procedure. Intraoperatively, the dilatation appeared to be caused by a localized chronic dissection of the pulmonary autograft. Surgery consisted of a modified Bentall procedure with a mechanical composite valve, with an uncomplicated postoperative course.

[Long-term results of the Ross procedure]

Aortic valve replacement with a pulmonary autograft (Ross procedure) was pioneered by Donald Ross in 1967. The advantages of the autograft valve include freedom from anticoagulation, hemolysis, and infection, optimal hemodynamic performance, and growth potential. Various materials have been used for the right ventricular outflow tract (RVOT). Currently, a cryopreserved pulmonary allograft is accepted worldwide as a useful material for this procedure. Pulmonary allografts cannot be utilized in Japan, and thus other valves and materials must be used instead. The acceptance of these procedures has been slow because of the technical demands of the operations and the inherent need for reconstruction of the RVOT, thereby placing two valves at risk. In the past 20 years, the Ross procedure has been increasingly considered for pediatric patients with a wide spectrum of congenital abnormalities.

The Ross operation: a Trojan horse?†

AIMS

The Ross operation is the operation of choice for children who require aortic valve replacement (AVR) and may also provide a good option in selected adult patients. Although the autograft does not require anticoagulation and has a superior haemodynamic profile, concern regarding autograft and allograft longevity has risen. In this light, we report the 13-year results of our prospective autograft cohort study.

METHODS AND RESULTS

Between 1988 and 2005, 146 consecutive patients underwent AVR with a pulmonary autograft at Erasmus Medical Center Rotterdam. Mean age was 22 years (SD 13; range 4 months-52 years), 66% were male. Hospital mortality was 2.7% (N = 4); during follow-up four more patients died. Thirteen-year survival was 94 +/- 2%. Over time, 22 patients required autograft reoperation for progressive neo-aortic root dilatation. In addition, eight patients required allograft reoperation. Freedom from autograft reoperation at 13 years was 69 +/- 7%. Freedom from allograft reoperation for structural failure at 13 years was 87 +/- 5%. Risk factors for autograft reoperation were previous AVR and adult patient age.

CONCLUSION

Although survival of the Rotterdam autograft cohort is excellent, over time a worrisome increase in reoperation rate is observed. Given the progressive autograft dilatation, careful follow-up of these patients is warranted in the second decade after operation.

Time-related Histopathologic Analyses of Immunologically Untreated Porcine Valved Conduits Implanted in a Porcine-to-Goat Model

This study was performed to evaluate the clinical feasibility of use of immunologically nontreated xenogenic valves, using a porcine-to-goat pulmonary valved conduit implantation model. Porcine pulmonary valve conduits were prepared with no specific immunological treatment and implanted in the right ventricular outflow tract of goats under cardiopulmonary bypass. The goats were assigned at predetermined intervals (1 day, 1 week, and 3, 6, and 12 months) as two animals for each interval. Echocardiographic examinations of the valves were performed before sacrifice. Upon retrieving the xenograft specimens, they were inspected visually and microscopically. Ten of the 12 animals survived the predetermined observation periods. Variable degrees of pulmonary regurgitation were the main findings on echocardiographic evaluations. On gross examination of the explanted specimens, all leaflets, except in one animal that prematurely died, were fairly well preserved. They were slightly shortened but free of thrombosis or vegetation. Aneurysmal dilatations of the anterior wall of the implanted pulmonary artery were observed in one of 12-month-survival animals and in another one of 3-month-survival animals. Microscopically, the three components of implanted xenografts (the pulmonary artery, valve, and infundibulum) were shown to be gradually replaced with host cells in time, while maintaining structural integrity. The nuclei of the donor tissue disappeared through pyknosis and karyolysis. In conclusion, immnunologically untreated xenogenic pulmonary valved conduits can be an alternative potential as valve substitutes with distinctive advantages of providing self-healing potential, despite a few problems observed in the current study such as occurrences of pulmonary regurgitation and sporadic cases of aortic aneurysm.

Autografts, homografts, and xenografts: overview on stentless aortic valve surgery

Stentless valves, either human (autografts, homografts) or animal (porcine xenografts), were historically among the first substitutes to be used to replace the diseased aortic valve. Forty years after those pioneering days and 15 years after revival of such valves, stentless grafts have become a mainstay in aortic surgery. Although limitations associated with the use of autografts, homografts and xenografts remain, stentless valves have profoundly improved quality of life after aortic valve/root replacement. In addition, stentless surgery has greatly advanced the understanding of aortic root anatomy, physiology and pathology among surgeons.

Ten-year experience with the Ross operation

OBJECTIVE

To evaluate the 10-year outcomes of the Ross Operation, analyzing survival rate, incidence of reoperations, and late performance of pulmonary autografts and homografts in the reconstruction of the right ventricular outflow tract.

METHODS

Two hundred and twenty seven patients with a mean age of 29.1 +/- 11 years underwent Ross operation from May 1995 to February 2005. The most prevalent etiology was rheumatic disease in 61% of the cases. Autografts were implanted using the total root replacement technique in 202 cases, with intraluminal cylinder in 20, and in the subcoronary position in 5. The right ventricular outflow tract was conventionally reconstructed with cryopreserved homografts (n = 160), with proximal extension of the homograft with pericardium (n = 41), and with decellularized homografts (n = 26). The postoperative follow-up ranged from 1 to 118 months (mean = 45.5 months).

RESULTS

Hospital mortality was 3.5%, and long-term survival was 96.9% at ten years. No episodes of thromboembolism and only two cases of endocarditis occurred. Eleven patients underwent reoperation because of problems related to the auto and/or homograft, progression of rheumatic mitral valve disease, and iatrogenic coronary insufficiency. After 10 years, 96.4% and 96.2% of the patients were free from reoperation in the autograft and homograft groups, respectively. No late autograft dilatation was observed. Reconstruction of the left ventricular outflow tract with decellularized homografts significantly reduced the incidence of gradients on late follow-up.

CONCLUSION

Late outcomes with the Ross Operation were associated with an excellent long-term survival and a low incidence of reoperations and late morbidity. We consider this procedure the best option for the surgical treatment of aortic valve disease in children and young adults.

Modified (Valsalva graft) aortic root reimplantation for successful repair of pulmonary autograft aneurysm after Ross procedure

Dilatation of the pulmonary autograft after the Ross procedure is a possible complication, necessitating aortic valve replacement. We present a case of a patient who developed pulmonary autograft dilatation and was treated successfully with valve-sparing aortic root reimplantation with a Valsalva graft.

Pulmonary homograft muscle reduction to reduce the risk of homograft stenosis in the Ross procedure

OBJECTIVE

The Ross procedure has gained increasing interest as an attractive alternative for aortic valve replacement. Despite its advantages, there is a certain risk of structural valve deterioration, especially of the pulmonary homograft as a result of shrinkage and subsequent stenosis predominantly at the muscular annulus. Theoretically, reduction of homograft muscle tissue could reduce this risk.

METHODS

From February 1996 through December 2002, a total of 238 patients (mean age 44 +/- 13.2 years) underwent the Ross procedure with the subcoronary technique with follow-up investigations before discharge and after 12 and 24 months. To estimate the importance of homograft muscle reduction within our institution-specific risk factor scale for change of transhomograft pressure gradient with time, we performed a generalized estimating equation approach, which identified homograft muscle reduction, higher body surface area in male patients, younger patient age, smaller homograft diameter, blood transfusions, and follow-up time as independent risk factors demonstrating a high beta value (-2.8638) for muscle reduction. To find out whether muscle reduction influences transhomograft pressure gradient, we compared patients with (group A, n = 39) and without (group B, n = 199) muscle reduction. The other mentioned independent risk factors were not different between groups, except for blood transfusions (group A greater than B, P < .01), indicating a negative bias for group A.

RESULTS

The maximum pressure gradient across the homograft was lower in patients with muscle reduction before discharge (4.5 +/- 2.8 mm Hg group A vs 6.2 +/- 3.8 mm Hg group B, P = .004) and after 1 (9.3 +/- 5.8 vs 13.1 +/- 8.4 mm Hg, P = .028) and 2 years (10.8 +/- 7.6 vs 13.7 +/- 7.5 mm Hg, P = .013). No significant differences were found concerning homograft insufficiency.

CONCLUSIONS

We provide some evidence that transhomograft pressure gradient can be reduced significantly within the first 2 years after operation by homograft muscle reduction. Longer term follow-up is necessary to evaluate this promising operative technique further.

Subcoronary Ross Procedure in Patients With Active Endocarditis

BACKGROUND

The Ross procedure has gained increasing interest as an attractive alternative to a prosthetic aortic valve substitute within the last decade. Because of a probably better resistance to infection as one of its advantages, the pulmonary autograft is theoretically preferable for active endocarditis.

METHODS

Between June 1994 and July 2003, the Ross procedure was performed using the subcoronary and inclusion technique in 296 patients (231 male, 65 female). Twenty patients had an active endocarditis of the aortic valve at the time of operation. A bicuspid valve was present in 10 patients. One patient had previous aortic valve surgery. Clinical and echocardiographic follow-up was complete.

RESULTS

Early mortality was 1, late mortality was 0. There were no recurrence of endocarditis and no neurologic events during the mean follow-up of 47.3 +/- 28.6 months. All patients were in New York Heart Association class I. Mean and maximum pressure gradient across the autograft was 3.5 +/- 2.0 and 6.5 +/- 3.4, respectively, with no autograft insufficiency in 15, 1+ in 4. Comparing postoperative with the last investigations, there were no significant changes of pressure gradients or grade of regurgitation. Mean and maximum homograft pressure gradients were 7.9 +/- 3.7 and 16.2 +/- 8.1 mm Hg, respectively, at last investigation; most patients had no or mild homograft regurgitation (0+, n = 13; 1+, n = 5; 2+, n = 1).

CONCLUSIONS

Native valve endocarditis can be treated with excellent results using the Ross procedure with the subcoronary and inclusion technique, with low mortality and morbidity rates and a very low recurrence rate of endocarditis.

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.

Degeneration of the pulmonary autograft: An explant study

OBJECTIVE

We sought to determine the histologic features of pulmonary autografts explanted after the Ross operation.

METHODS

Histologic sections of 30 explanted autografts and 8 normal heart valves were compared and semiquantitatively scored by a blinded cardiovascular pathologist.

RESULTS

Pulmonary autografts (n = 30) were explanted on average 6.1 +/- 0.6 years (median, 6.6 years; range, 0.1-11.7 years) after the Ross operation (n = 28) or removed at autopsy (n = 2). Twelve (43%) of the patients undergoing reoperation had no or negligible autograft insufficiency on early transthoracic echocardiography, 12 (43%) had grade 1 autograft insufficiency, and 4 (14%) had grade 1-2 autograft insufficiency. Valve regurgitation with root dilatation was the most common indication for reoperation after root replacement (n = 26 [93%]) and regurgitation after subcoronary implanted autografts (n = 2 [7%]). Microscopy of the autograft explants revealed normal laminar architecture and cellularity. Wall specimens were characterized by reduced and fragmented elastin and increased collagen levels (fibrosis). Medial elastin changes were associated with the presence of hypertrophic smooth muscle cells. Fibrosis was most severe in the adventitia. Intimal thickening was a common finding. Valve explants showed significant thickening caused by fibrocellular tissue on the ventricular surface and marked thickening of the free margin. An autopsy explant with normal function before death showed similar features.

CONCLUSIONS

Pulmonary autograft explants showed severe aneurysmal degeneration of the wall, which was characterized by intimal thickening, medial elastin fragmentation, and adventitial fibrosis. Valve leaflets were thickened. The presence of these features in a nonfailing explant suggests these changes represent a common mode of remodeling.

Geometric models of the aortic and pulmonary roots: suggestions for the Ross procedure

OBJECTIVE

To discuss geometric factors, which may influence long-term results relating to homograft competence following the Ross procedure, we describe the 3D morphology of the pulmonary and aortic roots.

MATERIALS

Measurements were made on 25 human aortic and pulmonary roots. Inter-commissural distances and the heights of the sinuses were measured. For geometrical reconstruction the three commissures and their vertical projections at the root base were used as reference points.

RESULTS

In the pulmonary root, the three inter-commissural distances were of similar dimensions (17.9+/-1.6mm, 17.5+/-1.4mm and 18.6+/-1.5mm). In the aortic root, the right inter-commissural distance was greatest (18.8+/-1.9mm), followed by the non-coronary (17.4+/-2.0mm) and left coronary sinus commissures (15.2+/-1.9mm). The mean height of the left pulmonary sinus was greatest (20+/-1.7mm) followed by the anterior (17.5+/-1.4mm) and right pulmonary sinus (18+/-1.66mm). In the aortic root, the height of the right coronary sinus was the greatest (19.4+/-1.9mm) followed by the heights of the non-coronary (17.7+/-1.8mm) and left coronary sinus (17.4+/-1.4mm). Measured differences between parameters determine the tilt angle and direction of the root vector. The tilt angle in the pulmonary root averaged 16.26 degrees , respectively; for the aortic roots, it was 5.47 degrees .

CONCLUSIONS

Herein we suggest that the left pulmonary sinus is best implanted in the position of the right coronary sinus, the anterior pulmonary in the position of the non-coronary sinus and the right pulmonary sinus in the position of the left coronary sinus. In this way, the direction of the pulmonary root vector will be parallel to that of the aortic root vector.

Medium-term results from pulmonary autografts after the Ross procedure in children and adolescents

INTRODUCTION

The Ross procedure is being used increasingly for the treatment of aortic valve problems in children, but the long-term prospects of the pulmonary autograft and its ability to grow continue to be controversial. This study summarises the experience of our centre from using the Ross procedure in children and adolescents.

METHODS

During the period November 1996 to March 2004, 35 children aged 3 months to 18 years (mean 10.6 +/- 5.4 years) and weighing 3.2-71 kg (mean 35.4 +/- 19.8 kg) underwent the Ross procedure for the treatment of aortic valve disease (stenosis--25, 71.4%; regurgitation--5, 14.3%; mixed--5). The majority of patients (n=26, 74.2%) had a history of aortic valve procedures. The technique employed was replacement of the aortic root with the pulmonary autograft. All patients were followed for 16-87 months (mean 37 months) with clinical and echocardiographic examinations, which were performed before discharge, 3-6 months later, and then every year.

RESULTS

Perioperative mortality was zero. There was one late (sudden) death 3 years after the procedure. Actuarial 7-year survival was 97.1 +/- 2.9% and freedom from reoperation for any reason was 100%. Two patients (5.7%) needed balloon dilatation because of pulmonary stenosis. All patients were in New York Heart Association functional class I. Haemodynamic parameters at the last follow-up examination were similar to those immediately post procedure: 12 patients (versus 11) had trivial and 3 mild aortic regurgitation. The pulmonary autograft followed the patient's body growth. The diameter of the aortic annulus increased from 19.1 +/- 3.9 mm to 21.6 +/- 2.8 mm and the diameter of the sinuses of Valsalva from 25.6 +/- 5.8 mm to 28.7 +/- 4.6 mm.

CONCLUSIONS

The Ross procedure seems to be the ideal solution for aortic valve problems in children, because of the small perioperative risk, the excellent haemodynamic results, and the potential of the autograft to grow, as shown by medium-term follow up.