M Bechtel

A Critical Reappraisal of the Ross Operation Renaissance of the Subcoronary Implantation Technique

Background— The autograft procedure, an option in aortic valve replacement, has undergone technical evolution. A considerable debate about the most favorable surgical technique in the Ross operation is still ongoing. Originally described as a subcoronary implant, the full root replacement technique is now the most commonly used technique to perform the Ross principle. Methods and Results— Between June of 1994 and June of 2005, the original subcoronary autograft technique was performed in 347 patients. Preoperative, perioperative, and follow-up data were collected and analyzed. Mean patient age at implantation was 44±13 years (range 14 to 71 years; 273 male, 74 female). Bicuspid valve morphology was present in 67%. The underlying valve disease was aortic regurgitation in 111 patients, stenosis in 46 patients, combined lesion in 188 patients, and active endocarditis in 22 patients (in 2 patients without stenosis or regurgitation). Concomitant procedures were performed in 130 patients. Clinical and echocardiographic follow-up visits were obtained annually (mean follow up 3.9±2.7 years, 1324 patient-years; completeness of follow-up 99.4%). The in-hospital mortality rate was 0.6% (n =2), and the late mortality was 1.7% (n=6), with 5 noncardiac deaths (4 cancer, 1 multiorgan failure after noncardiac surgery) and 1 cardiac death (sudden death). At last follow-up, 94% of the surviving patients were in New York Heart Association class I. Ross procedure–related valvular reoperations were necessary in 9 patients: Three received autograft explants, 5 received homograft explants, and 1 received a combined auto- and homograft explant. At last follow-up visit, autograft/homograft regurgitation grade II was present in 5/10 patients and grade III in 4/0. Maximum/mean pressure gradients were 7.4±6.2/3.7±2.1 mm Hg across the autograft and 15.3±9.4/7.6±5.0 mm Hg across the right ventricular outflow tract, respectively. Aortic root dilatation was not observed. Freedom from any valve-related intervention was 95% at 8 years (95% confidence interval 91% to 99%). Conclusion— Midterm follow-up of autograft procedures according to the original Ross subcoronary approach proves excellent clinical and hemodynamic results, with no considerable reoperation rates. Revival of the original subcoronary Ross operation should be taken into account when considering the best way to install the Ross principle.

Fourteen years' experience with 501 subcoronary Ross procedures: surgical details and results.

OBJECTIVE During the past decade the Ross procedure using the full root has become the predominant surgical technique. However, progressive autograft dilatation and eventual failure remain a concern. Here we report on the surgical techniques and results of the subcoronary technique over a 14-year period. METHODS A total of 501 patients (mean age, 44.9 ± 12.9 years; 117 female; 384 male) were operated on from June 1994 to December 2007. The follow-up database, with a completeness of 98.2%, was closed on December 2008, comprising of 2931 patient-years with a mean follow-up of 5.9 ± 3.6 years (range, 0.1-14.1 years). RESULTS Surgical details are presented. Early and late mortality were 0.4% (n = 2) and 4% (n = 20), respectively, valve-related mortality was 1.2% (n = 6), whereas the overall survival did not differ from that of the normal population. Neurologic events occurred in 22 patients, major bleeding in 9, autograft endocarditis in 8, and homograft endocarditis in 10. Freedom from autograft and homograft reoperation was 91.9% at 10 years. For the majority of patients, hemodynamics was excellent and no root dilatation was observed. CONCLUSIONS Midterm results after the original subcoronary Ross procedure are excellent, including normal survival and low risk of valve-related morbidity. Longer-term results are necessary for continuous judgment of the subcoronary technique.

Ross Procedure and Left Ventricular Mass Regression

Background—Return of left ventricular mass to normal is considered to be a favorable result of aortic valve replacement. The Ross procedure provides near normal hemodynamics and thus allows studies of left ventricular (LV) reverse remodeling. LV mass regression may be influenced by surgical technique (subcoronary [SC] versus root replacement [RR]). Methods and Results—Data from the German Ross Registry were analyzed. A total of 646 patients (mean age: 43.6±12.7 years, range: 16 to 71 years; SC technique n=295, RR technique n=351) underwent a Ross procedure in 7 participating centers from 1990 to 2004. The patients underwent preoperative and postoperative echocardiographic evaluations. Mean follow-up time was 3.5±2.5 years (range 0.12 to 13.7 years). Follow-up completeness was 97%. The LV mass index (LVMI) decreased significantly during follow-up in both groups (SC: 209±53 preoperatively to 154±48 at 1-year follow-up, [P<0.01 versus preoperative values] to 149±51g/m2 at 2-year follow-up, [P=NS 1-year versus 2-year follow-up] versus RR: from 195±56 preoperatively to 144±51 at 1-year follow-up [P<0.01 versus preoperative values] to 140±49g/m2 [P=NS 1-year versus 2-year follow-up]). LVMI regression remained stagnant 1 year after the Ross procedure in most patients in both groups. On the basis of multivariate analysis, predictors for incomplete LVMI regression after the autograft procedure were high preoperative LVMI, smoking, and uncontrolled diastolic hypertension. Conclusions—At mid-term echocardiographic follow-up, patients of both groups had favorable autograft hemodynamics. Risk factors for incomplete postoperative LVMI regression in our study were smoking and persistent diastolic hypertension. This emphasizes the importance of cessation of smoking and treatment of arterial hypertension, even in younger patients, after corrected aortic valve disease.

Decellularized pulmonary homograft (SynerGraft) for reconstruction of the right ventricular outflow tract: first clinical experience

Einleitung: Kryokonservierte klappentragende Homografts werden zur Rekonstruktion des rechts- und linksventrikulären Ausflusstraktes eingesetzt. In Langzeitverlauf treten degenerative Veränderungen auf, wobei immunologisch vermittelte Phänomene ähnlich der chronischen Abstoßung als Mitursache angenommen werden. Durch die Entwicklung von dezellularisierten, nicht-glutaraldehydfixierten klappentragenden Konduits sollte eine nicht-immunogene bindegewebige Matrix geschaffen werden, die als Basis der autologen Rezellularisierung durch den Träger dient. Ziel der Untersuchung war die klinische und hämodynamische Charakterisierung nach erstem Einsatzes von dezellularisierten pulmonalen Homografts (SynerGraft) beim Menschen. Methode: Eine Rekonstruktion des rechtsventrikulären Ausflusstraktes wurde bei 17 Patienten durchgeführt: 15 Patienten mit Aortenklappenerkrankungen und Ross-Operation und zwei Patienten mit Reoperationen bei Fallotscher Tetralogie und schwerer Pulmonalinsuffizienz. Als Kontrollgruppe dienten Patienten mit Ross-Operation unter Verwendung konventioneller, kryokonservierter Homografts. Während der Verlaufsbeobachtung bis sechs Monaten wurden echokardiographisch morphologische und dynamische Parameter charakterisiert: maximaler und mittlerer Druckgradient über dem rechten und linken Ausflusstrakt, effektive Öffnungsfläche des rechten und linken Ausflusstraktes, Bestimmung einer Regurgitation über der Neopulmonal- und Neoaortenklappe. Ergebnisse: Ein Patient verstarb sechs Wochen postoperativ an einer nicht klappen-assoziierten therapierefraktären kardiopulmonalen Erkrankung, alle Patienten waren frei von klappen-bezogenen Komplikationen während der Verlaufsbeobachtung. Die Ross-Patienten der Kontrollgruppe wiesen einen stetigen, signifikanten Anstieg des maximalen und mittleren Druckgradienten über dem konventionellen Homograft auf (ΔP max 5,5±2,5 auf 11,4±6,4 mmHg, p=0,002; ΔP mean 3,0±1,3 auf 6,2±3,9 mmHg, p=0,003), in der SynerGraft-Gruppe war eine frühe, statistisch insignifikante Druckgradientzunahme messbar (ΔP max 7,1±3,7 auf 10,1±3,9mmHg, p=0,11; ΔP mean 3,6±1,6 auf 5,5±2,3mmHg, p=0,12). Die effektive Öffnungsfläche der Neopulmonalklappe nahm innerhalb der Periode der Verlaufsbeobachtung in der Kontrollgruppe von 1,74±0,33 auf 1,18±0,36 cm2/m2 ab (p=0,001), in der SynerGraft-Gruppe war die zeitabhängige Reduktion der effektiven Öffnungsfläche signifikant geringer (1,51±0,37 auf 1,25±0,26 cm2/m2; p=0,08). Schlussfolgerung: Bis zu einem halben Jahr nach Implantation erwiesen sich die dezellularisierten Homografts zur Rekonstruktion des rechtsventrikulären Ausflusstraktes als sicher, stabil und erfolgsversprechend in Hinblick auf die effektive Klappenöffnungsfläche und ihre Flussdynamik. Introduction: Cryopreserved homograft valve conduits have been used to reconstruct the right and left ventricular outflow tract. Long-term studies have shown homograft degeneration and calcification, and it has been postulated that immunological mediated phenomena in a manner similar to that seen in chronic rejection may contribute to the degeneration process. The development of a decellularized, non-glutaraldehyde-fixed valve conduit creates a non-immunogenic connective tissue matrix for autologous recellularization by host cells. The aim of the study was to characterize the clinical and hemodynamic pattern in human implants of the novel decellularized pulmonary homografts (SynerGraft). Methods: Reconstruction of the right ventricular outflow tract was performed in 17 patients: 15 patients with aortic valve disease and the Ross procedure, and two patients with redo procedures following Fallot tetralogy and severe pulmonary regurgitation. Patients with the Ross procedure with standard cryopreserved homografts as neopulmonic conduits served as controls. Within the follow-up over six months morphological and hemodynamic parameters were characterized by echocardiography: maximal and mean pressure gradient across the right and left ventricular outflow tract, their effective orifice areas, determination of neopulmonic and neoaortic regurgitation. Results: One patient died six weeks following surgical treatment due to non-valve related end-stage cardiopulmonary failure; all patients were free of valve-related complications during the follow-up period. The matched Ross patients showed a gradual but significant increase of both the maximal and mean pressure gradient across the right ventricular outflow tract (ΔP max 5.5±2.5 to 11.4±6.4 mmHg, p=0.002; ΔP mean 3.0±1.3 to 6.2±3.9 mmHg, p=0.003), whereas in the SynerGraft group increase of pressure gradients were measurable but did not reach statistical significance (ΔP max 7.1±3.7 to 10.1±3.9 mmHg, p=0.11; ΔP mean 3.6±1.6 to 5.5±2.3 mmHg, p=0.12). The pulmonary effective orifice areas decreased in the control group from 1.74±0.33 to 1.18±0.36cm2/m2 (p=0.001). Within the SynerGraft group time dependent reduction of the orifice area was significantly less (1.51±0.37 to 1.25±0.26 cm2/m2; p=0.08). Conclusion: Up to six months after implantation reconstruction of the right ventricular outflow tract with decellularized homografts was safe, stable, and the morphological and hemodynamic features are promising.

Major adverse cardiac events after the Ross operation in 1606 patients: current status of the German-Dutch Ross registry with up to 19 years follow-up

Background: The Ross operation has reached the 5th decade with good long term results from the pioneer series. There is gaining concern however about autograft and allograft durability over time. Furthermore, reports about major adverse cardiac events (MACE) as required by the latest guidelines update, in a large Ross patient cohort are scarce in the literature. It was the aim of this study to report the MACE in patients being treated with the Ross procedure. Methods: 1606 patients (mean age 39.3±16.1, range 0.0 –70.5y), male=1202, female=404) underwent a Ross procedure with a mean follow-up of 5.4±3.9y (7817 pt years, range 0.1–18.7y). Data from the prospective German-Dutch Ross Registry with 12 participating centers were evaluated in accordance to the 2008 guidelines of reporting mortality and morbidity after cardiac valve interventions. Results: Follow-up was complete in 94.6%. All cause mortality was n=69 (4.3%, cardiac=40, 2.5%, unknown=1). Overall survival was 97.7% at 5y and 95.2% at 10y. Structural and non-structural autograft failure with the need of reoperation occurred in n=70 (4.4%), autograft endocarditis with reoperation was present in n=12 (0.8%) resulting in a freedom from autograft reoperation of 97,1% at 5y and 93.0 % at 10y (mean time to reoperation 6.1±4.72y, median 5.7y). Allograft failure with the need of reoperation occurred in n=56 (3.5%) with a freedom from allograft reoperation of 96.9% at 5y and 93.7% at 10y (mean time to reoperation 4,3±3.8y, median 2,6y). 10 valvuloplasties were included in these numbers. Freedom from autograft and allograft reoperation was 94.5% at 5y and 88.1% at 10y. Infective endocarditis (conservative or medically treated) occurred in n=45 (linearized occurrence rate 0.57%/patient-year), thrombotic and thromboembolic events (including transient ischemic attacks) were observed in n=38 (linearized occurrence rate 0.48%/patient-year). Conclusion: A low rate of MACE in the long term after the Ross operation was observed in the registry. The large cohort enables to define subsets of patients who could be at risk for autograft reoperation. Caution ought to be attended to allograft and autograft endocarditis, since almost one fifth of all reoperations were associated with infective endocarditis.