What is the Proper Place of the Ross
Procedure in Our Modern Armamentarium?
Duke E. Cameron, MD, and Luca A. Vricella, MD
Corresponding author
Duke E. Cameron, MD
Division of Cardiac Surgery, The Johns Hopkins Medical
Insitutions, 600 N. Wolfe Street, Blalock 618, Baltimore, MD
21287, USA.
E-mail: dcameron@jhmi.edu
Current Cardiology Reports 2007, 9:xx–xx
Current Medicine Group LLC ISSN 1523-3782
Copyright © 2007 by Current Medicine Group LLC
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.
“As I see it, you’re still short one valve.”
Norman Shumway
Introduction
The feasibility of replacement of the aortic valve with an
autologous pulmonary valve was first demonstrated in the
laboratory in a canine model by Stofer and Shumway [1]. Sir
Donald Ross performed the first clinical pulmonary valve
autograft in London in 1967, a procedure that now bears his
name [2]. The early iterations of the procedure differed
significantly from modern versions, mainly in that the pulmonary
autograft was sewn within the native aorta in a subcoronary
position (rather than as a free root replacement) and the
pulmonary valve was replaced with an aortic homograft (rather
than a cryopreserved pulmonary homograft) (Fig. 1) [3]. Within a
short time it became clear that the autologous pulmonary valve
satisfied several of the criteria of ideal valve replacement:
excellent hemodynamics, durability on par with a human
lifespan, freedom from thromboembolism and endocarditis, and
freedom from injury to blood elements [4–8].
However, widespread adoption of the procedure remained
elusive. Though reverent to Ross’s technical tour de force, most
surgeons were skeptical that the greater complexity and risk of
the procedure was offset by its advantages; this was particularly so
in an era of imperfect myocardial protection and
cardiopulmonary bypass, when longer operations carried
significantly greater rates of mortality. Indeed, 30 years after the
first Ross procedure, less than 100 cardiac surgeons worldwide
had performed the procedure [3].
The renaissance of the Ross procedure is generally credited
to Ronald Elkins of Oklahoma City, Oklahoma, who began a
series of aortic valve replacement (AVR) in children in the late
1980s using pulmonary autografts [9]. In this group of patients
the results with conventional valvuloplasty and replacement with
prostheses were often unsatisfactory. Mechanical prostheses in
particular had limited value, as none were suitable for small
infants, there was no potential for growth and it was technically
difficult to oversize an AVR in anticipation of somatic growth;
furthermore, a lifetime of therapeutic anticoagulation was
unattractive. On the other hand, biologic prostheses, including
aortic homografts and various xenografts, suffer accelerated
calcification and degeneration in the young, and durability was
poor [10]. Elkins et al. [11,12] were able to demonstrate low
operative risk and low rates of thromboembolism and
endocarditis, absence of need for anticoagulation, and indeed
growth of the autograft. Encouraged by these results, many
centers embarked on ambitious programs of pulmonary
autotransplantation, an experience that was tracked by an
international registry established in 1993 and maintained by
Oury [13] in Montana. The experience of several thousand cases
worldwide taught several valuable lessons. A consensus evolved
that 1) the operation was reproducible though technically
demanding [14,15]; 2) late autograft dilatation was common
though not necessarily problematic or associated with valve
incompetence [16]; 3) bicuspid aortic valve patients, patients with
a dilated native aortic annulus, and patients with severe aortic
insufficiency were at greater risk for late autograft dilatation and
insufficiency [17]; 4) patients with rheumatoid disease had
inferior results [18]; 5) the Ross procedure was effective in the
setting of endocarditis; and 6) connective tissue disorders such as
Marfan syndrome were a contraindication because of the
intrinsic weakness of the pulmonary root. In addition, the
procedure was eventually extended to neonates and small infants
[20]. {AU: ref #19 missing; please call out in order in
text} Several replacement options for the pulmonary valve were
also described, including xenograft roots, bovine jugular vein,
and man-made pericardial valves. In recent years, recognition
that results were suboptimal in some subgroups led to a
restriction of indications and a slight decrease in the number of
Ross procedures performed annually, which is now performed
by over 200 surgeons in over 150 centers worldwide [21].
How Does the Pulmonary Autograft Behave in the
Aortic Position?
Initial concerns that the pulmonary valve would fail when
subjected to systemic arterial pressure were not substantiated.
Ross has stated that there has never been a documented case of
acute neoaortic insufficiency following the autograft procedure in
the absence of technical error or failure to recognize pulmonary
insufficiency before the valve transfer. Studies comparing flow
dynamics in the pulmonary and aortic roots showed comparable
features [22]. Though the aortic media is thicker than pulmonary
media and the pulmonary root has more fragmentation of elastic
fibers, with time the pulmonary root thickens and adapts to
higher pressure. Furthermore, it remains viable, elicits no
immune response, and maintains its resistance to
thromboembolism. The incidence of endocarditis or
thromboembolism in several series is 0% to 1% at 15 to 20 years
[21]. When subclinical microemboli were measured by
transcervical Doppler ultrasonography, Ross procedure patients
had significantly fewer high-intensity transient signals when
compared with patients with mechanical prostheses [23].
Hemodynamic performance, as assessed by effective orifice
area and transvalvular {AU: “transvalvular” meant here?}
gradients, nearly match those of normal aortic valves, and are
slightly superior to aortic homografts; durability of the autografts,
however, is far superior to that of homografts, particularly in the
very young [23]. The advantage of the autograft is also
particularly evident in athletes in whom mechanical prostheses
become inefficient at high heart rates [21]. Equally important,
there was excellent regression of left ventricular mass in
hypertrophied hearts after the procedure in a study of 646 Ross
patients; only persistent arterial hypertension and smoking were
risk factors for incomplete mass regression [24•].
Approximately 95% of patients have pulmonary and aortic
annular diameters within 3 mm of one another, but large size
discrepancies are a risk factor for late regurgitation, particularly
when the aortic diameter is greater than the pulmonary
[25••,26]. Although some authors have described size
mismatch as a risk factor for late autograft insufficiency, others
have ascribed the insufficiency to technical error [27].
Techniques to reduce and stabilize the aortic diameter (aortic
annuloplasty using supporting prosthetic bands, purse-strings, or
commissural plication) have been described and have nearly
neutralized the effect of mismatch, at least when the aortic
annulus is appreciably larger than the pulmonary annulus
[25••]. Thus, the pulmonary root is uniquely qualified to
replace the aortic root, with mild inconsequential dilatation being
the only perturbance in the majority of patients.
Does the Autograft Grow?
Unlike Ross’s large personal series, the series reported by Elkins
was composed primarily of children and a limited number of
young adults [5,11]. That experience documented a previously
unrecognized property of pulmonary autografts, namely autograft
growth [12]. Serial follow-up showed this process was not simple
dilatation, as is seen in nearly all autografts, but rather an agedependant growth; this remarkable feature makes the Ross
procedure unique and firmly establishes it as the procedure of
choice in infants and small children because of the severe
limitations of all valve prostheses in this age group. Even
homografts, which maintain some viability for several years after
implantation, do not demonstrate growth [29,30]. {AU: ref #28
missing; please call out in order in text}
What is the Operative Risk?
Ross’s original series spanned more than 20 years and began in
an era when cardiopulmonary bypass was hazardous and
techniques for myocardial protection were underdeveloped.
Long-term results of the pioneering series spanning 1967 to 1984
were reported in 1984 and 1997 [8,9]. Operative mortality was
7.9% overall. In the International Ross registry, operative
mortality is 3.3%, but several large series have reported mortality
rates similar to isolated AVR, that is, 1% to 2% [13–15].
Variances reflect era of operation, surgical experience, and
patient selection. Mortality in pediatric series has been slightly
higher, at 4% to 5% [25••], but these patients often have
undergone several operations before the Ross procedure, and
often have more complex abnormalities of the left ventricular
outflow tract.
Reporting biases in the literature, and indeed even
reporting in voluntary registries, tend to underestimate operative
risk. It is reasonable to assume that operative risk for this more
complex procedure, which involves two valves and a coronary
transfer, will always be greater than simple AVR, but the
difference should be small in the hands of experienced and
proficient aortic root surgeons, and offset in most patients by the
long-term advantages.
results of the latter continue to improve with refinements in valve
design and tissue treatments that retard calcification and
degeneration. Mechanical valves carry a 1% to 2% per patientyear risk of thromboembolism, endocarditis, or anticoagulantrelated morbidity. Durability of bioprostheses is age-related and
to a lesser extent commercial valve design [10]. Although the
elderly typically see good bioprosthetic valve function to 15 years
and beyond in the aortic position, durability is less in young
adults and unsatisfactory in children. This is the principal reason
that the Ross procedure is primarily an operation for young
patients.
Bicuspid Aortic Valve and the Ross Procedure
What are the Modes of Failure?
Pulmonary autograft transplantations may fail late because of
complications related to the autograft root (aneurysmal dilatation,
valvular insufficiency, endocarditis) or the pulmonary outflow
tract (stenosis, regurgitation, endocarditis). At 14 years after
surgery, Ross {AU: Matsuki et al. [8] and Chambers et al.
[9] referred to here?} reported an event-free survival of 73%,
freedom from valve-related death of 82%, freedom from
endocarditis of 96% and thromboembolism of 100%, freedom
from reintervention on the right ventricular outflow tract
(RVOT) of 97%, and freedom from autograft reoperation of
93%; all autograft reoperations were attributed to technical error
or late endocarditis [8,9]. At 20 years, survival was 80% and
freedom from autograft replacement was 85%. These results
must be interpreted in light of the era of surgery and the fact that
the majority of these operations were performed as subcoronary
implants, with the autograft sewn within the native root, which
obviated the need for coronary transfer. Also, aortic homografts
were used for the right heart reconstructions. Most centers today
prefer full root replacement rather than the inclusion technique,
as technical error is less likely; data have also shown superior
durability of pulmonary homografts over aortic homografts for
right heart reconstruction [31].
The series by Yacoub et al. [15] of 264 adult pulmonary
autograft cases gives a more current view of the modern Ross
procedure. Operative mortality was 2.3%. Cumulative survival
was 96.8% at 5 years and 95.4% at 10 years. At 10 years, freedom
from pulmonary homograft reoperation was 92.9% and freedom
from autograft reoperation was 98.6%. No risk factors for early
and late mortality and reoperation were identified.
Elkins’ [25••] series of 201 pediatric patients had similar
results. Operative mortality was 5%. Freedom from autograft
degeneration was 83% at 14 years. Freedom from pulmonary
allograft degeneration was 67% at 14 years. Many of Elkins’
patients could be expected to experience more rapid pulmonary
homograft degeneration, as children reject these grafts more
quickly than adults. Also, Elkins’ series included a substantial
number of extensive root and left ventricular outflow tract
reconstructions, and many patients had multiple previous
operations.
The above results must be compared with those of
mechanical valve and conventional bioprosthesis procedures; late
Patients with bicuspid aortic valve have long been known to have
associated aneurysms of the ascending aorta and root [17,32].
Initially attributed to altered flow dynamics across an abnormal
valve, an intrinsic defect in the extracellular matrix of the aortic
media probably underlies the tendency of autografts to dilate
more in patients with bicuspid aortic valve. This has led some
surgeons to abandon the Ross procedure altogether for these
patients, citing a higher risk of autograft dilatation and valvular
insufficiency. However, both Slater et al. [33] and Koul et al. [34]
have described surgical techniques to stabilize the autograft with a
Dacron (InVista, Wichita, KS) tube to prevent dilatation, which
at short-term follow-up appear to be effective. The reinforcement
modifications to the Ross procedure, as well as the use of annular
remodeling techniques to minimize size discrepancy in aortic and
pulmonary annular diameters (in particular much larger aortic
diameters frequently seen in bicuspid aortic valves) may
ultimately negate bicuspid aortic valve as a risk factor for longterm complications.
Occasionally young patients are seen with large ascending
aortic aneurysm and functionally normal bicuspid valve.
Although aneurysm replacement is indicated when maximal
diameter exceed 5 to 5.5 cm, the disposition of the native valve is
often in debate, and hinges on prediction of future performance
of the native valve. The Ross procedure is sometimes suggested
in this scenario, but is probably not appropriate because of the
considerations above; valve-sparing aortic root replacement is a
more suitable alternative.
Is the Ross a Good Operation for Endocarditis?
The pulmonary valve autograft has features that make it ideal for
aortic endocarditis. The valve is nearly always an appropriate
size, and because it is autologous tissue and viable, is peculiarly
resistant to infection [21]. The RVOT tissue below the autograft
is helpful for reconstructing annular damage from root infection.
Most endocarditis patients are young and therefore benefit from
a tissue “prosthesis” with better durability.
Several large series have demonstrated excellent results with
the Ross procedure in the setting of endocarditis, especially
prosthetic valve endocarditis, which can be especially challenging
[21]. However, Stelzer et al. [35] have cautioned against use of
the Ross procedure in active endocarditis, based on a 70%
incidence of complications in their group of 11 patients [35].
Cryopreserved aortic root homografts, when available, are a
useful alternative; they spare the pulmonary root and are simpler
and quicker to implant, but do not compare favorably with the
Ross in durability.
The Future
The relative merits and disadvantages of the Ross procedure are
summarized in Table 1, but the procedure has always been in
evolution. Areas for future development of the Ross procedure
include modifications of the autograft to support it in an effort to
prevent autograft dilatation and improve long-term results in
bicuspid aortic valve patients. Several techniques have been
described but more follow-up is necessary to confirm their
efficacy and identify limitations. Also, because stenosis or
insufficiency within the RVOT is the most common reason for
reoperation, strategies to improve durability of neopulmonary
valve will likely receive more attention. Refinements in tissue
processing of xenograft tissue may encourage more use of
alternatives to homografts, especially in areas of the world where
homograft tissue is not available. Finally, percutaneous catheter
delivery of stented xenografts valves to the pulmonary position as
described by Khambadkone and Bonhoeffer [36•] may
minimize need for conventional surgical reintervention,
particularly in young adults who require a pulmonary valve for
more than 15 to 20 years but not necessarily a larger one.
In pediatrics catheter intervention for congenital aortic
valve disease have had a major impact on the natural history, and
valve repair techniques are more attractive as temporizing
measures. The interaction of catheter techniques and use of the
Ross has produced an interesting debate that will continue as
long-term results of both unfold [37•,38•].
Conclusions
Pulmonary valve autotransplantation (Ross procedure) offers
young patients the possibility of a durable operation with
excellent valve hemodynamics, avoidance of anticoagulation,
minimal risk of late endocarditis and thromboembolism and a
risk for reoperation lower than conventional bioprostheses. In
older patients in whom bioprostheses last longer, the Ross does
not confer significant advantage. The ideal Ross procedure
candidate is a child or young adult whose valve cannot be
repaired, who would benefit from growth of the prosthesis, and
who wishes to avoid anticoagulation, particularly for childbirth.
Absolute contraindications are regurgitant pulmonary valves and
connective tissue diseases that render the autograft weak and
unstable. In many series the pulmonary homograft is the Achilles
heel of the procedure, and modifications of the procedure to
produce more durable RVOT reconstruction, as well as newer
catheter interventions to replace the pulmonary valve
percutaneously, may further improve long-term results of the
Ross procedure.
References and Recommended Reading
Papers of particular interest, published recently,
have been highlighted as:
• Of importance
•• Of major importance
{AU: bullets and annotations are meant to highlight only the
most recent references, ie, nothing published prior to 2004}
1.
Ross DN: Replacement of aortic and mitral valves with a pulmonary
autograft. Lancet 1967, 2:956–958.
2.
Lower RR, Stofer RC, Shumway NE: A study of pulmonary valve
autotransplantation. Surgery 1960, 48:1090–1100.
3.
Westaby S, Bosher C: Landmarks in Cardiac Surgery. Oxford: Isis
medical Media; 1997.
4.
Elkins RC, Lane MM, McCue C: Pulmonary autograft reoperation:
incidence and management. Ann Thorac Surg 1996, 62:450–455.
5.
Elkins RC: Pulmonary autograft: the optimal substitute for the aortic
valve? N Engl J Med 1994, 330:59–60.
6.
Gula G, Wain WH, Ross DN: Ten years' experience with pulmonary
autograft replacements for aortic valve disease. Ann Thorac Surg 1979,
28:392–396.
7.
Ross DN: Replacement of the aortic valve with a pulmonary autograft:
the "switch' operation. Ann Thorac Surg 1991, 52:1346–1350.
8.
Matsuki O, Okita Y, Almeida RS, et al.: Two decades' experience with
aortic valve replacement with pulmonary autograft. J Thorac
Cardiovasc Surg 1988, 95:705–711.
9.
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.
10. Al-Khaja N, Belboul A, Rashid M, et al.: The influence of age on the
durability of Carpentier-Edwards biological valves. Eur J Cardiothorac
Surg 1991, 5:635–640.
11. Elkins RC, Knott-Craig CJ, Randolph JD, et al.: Medium-term followup of pulmonary autograft replacement of aortic valves in children.
Eur J Cardiothorac Surg 1994, 8:379–383.
12. Elkins RC, Knott-Craig CJ, Ward KE, et al.: Pulmonary autograft in
children: realized growth potential. Ann Thorac Surg 1994, 57:1387–
1394.
13. Oury JH: The international registry of the Ross procedure: 1996
results. J Heart Valve Dis 1997, 6:333–334.
14. Kouchoukos NT, Davila-Roman VG, Spray TL, et al.: Replacement
of the aortic root with a pulmonary autograft in children and young
adults with aortic valve disease. N Engl J Med 1994, 330:1–6.
15. Yacoub MH, Klieverik LM, Melina G, et al.: An evaluation of the
Ross procedure in adults. J Heart Valve Dis 2006, 15:531–539.
16. Kouchoukos NT, Masetti P, Nickerson NJ, et al.: The Ross
procedure: long-term clinical and echocardiographic follow-up. Ann
Thorac Surg 2004, 78:773–781.
17. Fedak PW, de Sa MP, Verma S, et al.: Vascular matrix remodeling in
patients with bicuspid aortic valve malformations: implications for
aortic dilatation. J Thorac Cardiovasc Surg 2003, 126:797–806.
18. Al-Halees Z, Kumar N, Gallo R, et al.: Pulmonary autograft for aortic
valve replacement in rheumatic disease: a caveat. Ann Thorac Surg
1995, 60:S172–S175.
19. Oswalt JD, Dewan SJ: Aortic infective endocarditis managed by the
Ross procedure. J Heart Valve Dis 1993, 2:380–384.
20. Calhoon JH, Bolton JW: Ross/Konno procedure for critical aortic
stenosis in infancy. Ann Thorac Surg 1995, 60(6 Suppl):S597–S599.
21. Oswalt J: Acceptance and versatility of the Ross procedure. Curr Opin
Cardiol 1999, 14:90–94.
22. Lansac E, Lim HS, Shomura Y, et al.: Aortic and pulmonary root, are
their dynamics similar? Euro J Cardiothoracic Surg 2002, 21:268–275.
23. Notzold A, Droste DW, Hagedorn G, et al.: circulating microemboli
in patients after aortic valve replacement with pulmonary autografts
and mechanical valve prosthesis. Circulation 1997, 96:1843–1846.
24.• Duebener LF, Sierle U, Erasmi A, et al.: Ross procedure and left
ventricular mass regression. Circulation 2005, 112(Suppl I):I-415–I422.
Shows superior benefits of hypertrophy regression.
25.•• Elkins RC: Valve replacement in children/Ross procedure. In Mastery
of Cardiothoracic Surgery. Edited by Kaiser LR, Kron IL, Spray TL.
Lippincott Williams & Wilkins: Philadelphia; 2006.
Important update of Elkins’ pediatric experience.
26.
Svensson G, Alijassim O, Svensson SE, et al.: Anatomical mismatch of
the pulmonary autograft in the aortic root may be the cause of early
aortic insufficiency after the Ross procedure. Eur J Cardiothoracic
Surg 2002, 21:1049–1054.
27. Reddy VM, McElhinney DB, Phoon CK, et al.: Geometric mismatch
of pulmonary and aortic annuli in children undergoing the Ross
procedure: implications for surgical management and autograft valve
function. J Thorac Cardiovasc Surg 1998, 115:1255–1263.
28. Elkins RC, Lane MM, McCue C. Pulmonary autograft reoperation,
incidence and management. Ann Thorac Surg 1996, 62:450–455.
29. O’Brien MF, McGiffin DC, Stafford EG, et al.: Allograft aortic valve
replacement: long-term comparative clinical analysis of the viable
cryopreserved and antibiotic 4 C stored valves. J Card Surg 1991,
6:534–543.
30. Christie GW, Barratt-Boyes BG: Identification of a failure mode of
the antibiotic sterilized aortic allograft after 10 years: implications for
their long-term survival. J Card Surg 1991, 6:462–467.
31. Bando K, Danielson GK, Schaff HV, et al.: Outcome of pulmonary
and aortic homografts for right ventricular outflow tract reconstruction.
J Thorac Cardiovasc Surg 1995, 109:509–517.
32. Fedak PWM, Verma S, David TE, et al.: Clinical and
pathophysiological implications of a bicuspid aortic valve. Circulation
2002, 106:900–904.
33. Slater M, Shen I, Welke K, et al.: Modification of the Ross Procedure
to prevent autograft dilatation. Semin Thorac Cardiovasc Surg Pediatr
Card Surg Ann 2005, 8:181–184.
34. Koul B, Al-Rashidi F, Bhat M, et al.: A modified Ross operation to
prevent pulmonary autograft dilatation. Eur J Cardiothorac Surg 2007,
31:127–128.
35. Stelzer P, Weinrauch S, Transbaugh RF: Ten years experience with
the modified Ross procedure. J Thorac Cardiovasc Surg 1998,
115:1091–1100.
36.• Khambadkone S, Bonhoeffer P: Percutaneous pulmonary valve
implantation. Semin Thorac Cardiovasc Surg Pediatr Card Surg Annu
2006, 9:23–28.
Demonstrates potential of catheter intervention on right heart
valves.
37.• Jonas RA: The Ross procedure is not the procedure of choice for the
teenager requiring aortic valve replacement. Semin Thorac Cardiovasc
Surg Pediatr Card Surg Annu 2005, 8:176–180.
An excellent debate on the cons of the Ross procedure in
adolescents.
38.• Khwaja S, Nigro JJ, Starnes VA: The Ross procedure is an ideal aortic
valve replacement operation for the teen patient. Semin Thorac
Cardiovasc Surg Pediatr Card Surg Annu 2005, 8:173–175.
An excellent debate on the pros of the Ross procedure in
adolescents.
39.
Permut LC, Ricci M, Cohen GA: Surgery for left ventricular outflow
tract obstruction in children. In Johns Hopkins Manual of
Cardiothoracic Surgery. Edited by Yuh D, Vricella L, Baumgartner
W. Columbus: McGraw-Hill; 2006.
Figure 1. Technique of pulmonary valve autotransplant (Ross
procedure). Ao—aorta; LCA—left coronary artery; PA—pulmonary
artery; RCA—right coronary artery. (From Permut et al. [39]; with
permission.)