A long-term report in Circulation by Chambers et al. [8] in London with a collaboration by Ross reports that the pulmonary homograft was free of replacement 69% at 25 years; the autograft was free of replacement 88% at 10 years and 75% at 20 years.
8. Chambers JC, Somerville J, Stone S, Ross DN: Pulmonary autograft procedure for aortic valve disease, long term results of the pioneer series. Circulation 1997, 96:2206-2214
Thus the patient implanted with a mechanical aortic valve continues to run some long term risks of either a stroke or major bleeding episode in the range of 4 to 8% (combined) per year. Despite several generations of new valve materials and designs, the risk of these adverse events over time has not been reduced significantly.
Xenograft (animal tissue) valves usually begin to degenerate within 8 to 10 years after implantation. Within 15 years, over 30% of tissue valve recipients will need another valve replacement operation. In patients less than 60 years of age, the degenerative process occurs more quickly. In patients less than 40 years of age, animal tissues valves may degenerate within 5 years of implantation.
Most studies now indicate that a patient surviving more than 10 years after valve replacement surgery is better off with a mechanical replacement than a porcine or bovine tissue valve, even despite the added problems of chronic Coumadin®.
The freedom from reoperation for recipients of a pulmonary homograft was 83% at 18 years [Ross 1996].
At 20 years, only 15% of patients required another valve operation, usually replacement of the homograft reconstruction of the right ventricle [Ross 1996]. Patient survival at 18 years is an impressive 70%, making this operation superior to all other forms of aortic valve or root reconstruction.
In summary, there are many unique advantages to consider when recommending the Ross operation for patients with aortic valve disease, including:
Virtual absence of anticoagulation
Virtual absence of late thromboembolism (clots, strokes)
Absence transvalvar gradients (< 30 mmHg in every case)
Highly resistant to endocarditis.
Superior long term durability in the aortic position.
Low reoperation rate (15% at 20 years).
Documented growth after Ross operation when performed in children.
No sudden valve failures or sudden death from aortic valve malfunction.
The only aortic valve replacement made from living, viable tissue.
No possibility of rejection by the recipient (of the pulmonary autotransplant)
Low failure rate in the pulmonary homograft replacement.
Replacement of a failed pulmonary homograft is much lower risk than a redo aortic valve.
Improved safety (and long term durability) in women of child bearing age.
Analysis of the data, however, does reveal that premature failure of the homograft is much more common when human aortic tissue was used in the right side reconstruction, as opposed to human pulmonary tissue. There was only a 74% freedom from reoperation at 5 years when aortic homografts were used for the right ventricular reconstruction. However, there is a 94% freedom from reoperation at 5 years (and 83% at 20 years) when a pulmonary homograft is implanted into the right ventricular outflow tract. The reasons for this dramatic difference are not known. However, the pulmonic valve and supporting structures appears to be more tolerant, and possible less antigenic.
In summary, the major disadvantages of this operation for the surgical treatment of aortic valve disease are outlined below.
Lengthy operative times (over 2 and 1/2 hours to complete the repair)
Technically more demanding on the surgeons skills.
Cannot be used in every patient (such as those with Marfans syndrome or other connective tissue disorders)
Cannot be effectively combined with other valve operations or coronary bypass (due to the lengthy operative times required).
Limitations in availability of appropriate sized pulmonary homografts for replacing the donor site (particularly in children).
Theoretically converts a single valve patient to a double valve patient.
The main advantages of the pulmonary autotransplant (as compared with a prosthetic valve implant) are:
No artificial material is used for the "new" aortic valve.
All reconstructions are done with natural materials.
The crucial aortic valve reconstruction is performed entirely with the patients own pulmonary valve.
No matter the size of the patient, a gradient free aortic valve reconstruction can be obtained.
The only natural, potentially curative replacement for the aortic valve in small children or infants.
In growing children, the autotransplant is the only aortic valve replacement that provides a living, viable graft which will grow as the child grows.
The patients pulmonary valve is the right size and always available as a sterile graft.
The autotransplant is not rejected (since it comes from the patients own tissues),
No blood thinners are required
The autotransplant is noiseless (unlike most mechanical valves).
Patients can participate in any level of physical exertion they desire, including professional sports.
The current operative morbidity and mortality rates are very low, and nearly equal to prosthetic valve implants.
Currently, the Ross procedure is recommended primarily for patients with aortic valve disease and no other major cardiac problem. Within this group, the pulmonary autotransplant is an excellent choice for patients...
Who are less than 55 years of age (at the time of anticipated surgery) ... and ..
Who have a life expectancy of 20 years or more ... or ...
Who have a definate contraindication to anticoagulation, such as a history of bleeding . (regardless of age)
Woman of childbearing years
No other major cardiac lesion needing correction (multivessel coronary disease, mitral disease) except ascending aneurysm or mild to moderate root dilatation.
The following conditions are considered relative contraindications to using the pulmonary autotransplant procedure...
Coronary Artery Disease (due to the length of operation and limited life expectancy concerns).
Simultaneous mitral valve disease requiring surgical correction.
Obesity (medical comorbidity plus added operative risk).
Chronic Obstructive Pulmonary Disease (C.O.P.D) or Emphysema.
Marfans' syndrome (since pulmonary valve is also affected).
Connective tissue disorders (Systemic Lupus Erythematosis (SLE, Rheumatoid Arthritis (RA) since they can also affect the pulmoary valve).
Any structural abnormality of the pulmonic valve (as evidenced by preoperative exam or echocardiogram).
Postoperative patient survival at 20 years is an impressive 70% overall, making this operation the ideal choice for younger patients with aortic valve disease, or anyone with an anticipated life expectancy of more than 20 years following surgery.
More than 2 decades following surgery, only 15% of patients required any additional valve procedures and most of these were replacement of the right ventricular reconstruction, not the aortic substitute. Fortunately, it is easier and less morbid to replace the right ventricular substitute. Follow-up of recent Ross cases where a human pulmonary artery homograft was initially used to reconstruct the right ventricular outflow tract has shown a remarkable freedom from failure (94% at 5 years, 83% at 20 years).
I'm chatting with Stelzer about a Ross, and have done a fair amount or research, but I'm not hearing much about miserable results.
