Heart, Lung and Circulation (2014) 23, e96–e99

1443-9506/04/$36.00

http://dx.doi.org/10.1016/j.hlc.2013.10.097

CLINICAL SPOTLIGHT

Aortoventriculoplasty f

or Correction of Patient-Prosthesis Mismatch Examples

Kerem M. Vural, MD, FETCS*, Sertan Ozyalcin, MD, Ufuk Turkmen, MD,Tezcan Bozkurt, MD

Department of Cardiovascular Surgery, Turkiye Yuksek Ihtisas Hospital, Ankara, Turkey

Received 23 September 2013; received in revised form 25 October 2013; accepted 31

October 2013; online published-ahead-of-print 16 November 2013

Objective Patient-prosthesis mismatch is often considered as an important cause of adverse outcome following aortic

valve replacement. A small annulus represents a challenge for the surgeon; yet can be best managed at the

initial operation using relatively simple techniques, as later-on correction is often far more challenging.

Corrective reoperations necessitate drastic root enlargement, along with the relief of subvalvular muscular

obstruction.

Patients and

methods

The Konno-type aorto-ventriculoplasty is preferred in the present case series in order to achieve a radical

aortic annulus enlargement in difficult reoperation settings and to address the accompanying subvalvular

obstruction due to muscular hypertrophy simultaneously as well, with the septal patch included in the

technique.

Results This approach provides satisfactory relief of the obstruction at both valvular and subvalvular level and the

benefits are immediately evident, as symptoms abruptly end in all cases.

Conclusion Long-term outcome is also excellent in both clinical and haemodynamic terms, as reflected by the significant

left ventricle mass regression, absence of symptoms and improved quality of life.

Keywords Aortic valve � Heart valve prosthesis � Prosthesis fitting � Reoperation � Treatment outcome� Patient-prosthesis mismatch

IntroductionPatient-prosthesis mismatch (PPM), first described in 1978 by

Rahimtoola [1,2], can be defined as implanting too small a

prosthetic valve for the patient’s size, causing high trans-

valvular gradients [1,2]. Among the most helpful diagnostic

parameters, is the effective orifice area index (EOAI), mea-

sured in vivo following aortic valve replacement (AVR) by

echocardiographic examination. It is generally accepted that,

when the EOAI is less than 0.85 cm2/m2, there is some PPM,

and if it is less than 0.65, the mismatch is severe [1]. The

interpretation of PPM, its clinical importance, and even its

actual existence are still controversial; however, it has been

reported by many as an important cause of adverse outcome

following AVR [1,3], in terms of left ventricle mass regression

[4], and survival [5]. A stenotic prosthetic valve may cause

© 2013 Australian and New Zealand Society of Cardiac and Thoracic Surgeons (ANZSCTS) a

Inc. All rights reserved.

*Corresponding author at: N. Tandogan cad. 5/6 Kavaklidere, 06540 Ankara, Turke

unsatisfactory symptom relief, and less evident improve-

ments in functional capacity, life quality and life expectancy

[6], ending up with congestive heart failure [7] or sudden

death [8].

From this perspective, a small native aortic valve annulus

represents a challenge for the surgeon who attempts to

replace the aortic valve with an adequately large prosthesis;

yet can be best managed at the initial operation using

relatively simple techniques. Later-on correction is often

far more challenging. The corrective reoperations should

include drastic aortic annulus enlargement, in order to

replace the previously implanted stenotic valve with a

considerably larger one. Several such techniques involving

posterior (Nicks, Manougian) or anterior (Konno)

approaches have been described; however, we usually pre-

fer a Konno-type aorto-ventriculoplasty (AVPL) since it

nd the Cardiac Society of Australia and New Zealand (CSANZ). Published by Elsevier

y. Tel.: +90 312 426 7574; fax: +90 312 426 6181., Email: kvural@tr.net

Figure 1 The explanted 19 mm prosthetic mechanicalvalve, responsible for symptomatic, severe patient-prosthesis mismatch. A pencil is provided for size-comparison purposes.

Correction of Prosthesis Mismatch e97

generally provides the most satisfactory root enlargement

along with the relief of subvalvular muscular obstruction,

which is caused by the long-standing obstacle at the valve

level. This procedure, first described by Konno and asso-

ciates in 1975 [9], starts with a vertical incision encompass-

ing the anterior aorta, aortic valve annulus, and muscular

interventricular septum. This creates a ventricular septal

defect (VSD). A second extension of this incision is carried

onto the right ventricular outflow tract in order to provide

exposure. Enlargement of the proximal aorta, aortic annu-

lus and septal part of the left ventricular outflow tract is

achieved by an anteriorly positioned "trans-annular’’ lon-

gitudinal patch. This patch, oriented so as to make about

one third of the annular circumference for enlargement

purposes, also closes the surgically created VSD. After

suturing the prosthetic valve to the neo-annulus, a second

patch closes the "exposure-providing’’ incision on the right

ventricular outflow muscle, again providing some enlarge-

ment against any possible right ventricular outflow narrow-

ing. This second patch is then attached to the former to close

the remaining part of the incision. As this brief description

demonstrates, the Konno-AVPL is an immense operation of

a "high risk-high benefit’’ nature, and necessitates consid-

erable experience. It is generally associated with moder-

ately prolonged aortic cross-clamping durations (about two

hours in our reoperations experience), nevertheless this is

often well-tolerated by the left ventricle. Among the poten-

tial complications are low cardiac output state, right ven-

tricular failure, septal infarction, conduction disturbances,

pulmonary valve insufficiency, right ventricle outflow tract

obstruction, or inter-ventricular shunt due to leaks through

the septal patch. The Konno-AVPL was first introduced for

paediatric patients, in order to overcome the difficulty in

implanting a sufficiently large prosthesis in this group

having rapid growth potential. Nevertheless, we consider

it also ideal for the adult reoperations performed for PPM

correction, as it makes it possible to replace the stenotic

prosthesis with a considerably larger one in difficult reop-

eration circumstances. In addition, septal patch insertion is

a part of the procedure that effectively relieves the fre-

quently accompanying subvalvular muscular obstruction.

The benefits of satisfactory relief at both levels were imme-

diately evident, as symptoms abruptly ended in all our

cases. Long-term outcome was also excellent in both clinical

and haemodynamic terms, as reflected by the significant left

ventricle mass regression, absence of symptoms and

improved quality of life.

Technical details of this procedure can be found elsewhere,

and are beyond the scope of this study. It is not this paper’s

main objective to revisit the well-established technique, but

rather to contribute to the awareness for increasing number

of patients with PPM, to emphasise the importance of

implanting an adequately large prosthesis at the initial oper-

ation, and to remind practitioners of the perfect applicability

of aorto-ventriculoplasty procedure in these complicated

cases. From this perspective, the following text provides

several examples of PPM: a neglected root enlargement

during the initial operation; an exceedingly narrow aortic

root of congenital origin which was not addressed in the

previous operation; and a childhood aortic valve replace-

ment which subsequently led to a stenotic prosthesis in the

adult life. The technique was used in the following case series

with success, for correcting the actual mismatch in two cases,

and for avoiding a highly potential mismatch in another.

Case Series

Case-1A 23 year-old woman was admitted to our institution with

chest pain, exertional dyspnoea and syncope episodes in the

preceding three months. Her functional capacity was limited

to New York Heart Association (NYHA) Class-III. She had

undergone AVR with a 19 mm Sorin bileaflet mechanical

prosthesis (Sorin Group, Milan, Italy) (Fig. 1) for moderate

aortic insufficiency in a private hospital, four years ago. The

relevant data is presented in Table 1 in detail. This patient,

referred to our institution for severe PPM (effective orifice

area index-EOAI = 0.4 cm2/m2), underwent repeat AVR

with Konno-type enlargement of the anterior annulus and

outflow tract. With this approach: (1) the stenotic prosthesis

enveloped in the densely fibrotic ring could be explanted; (2)

the retracted and rigidly remodelled annulus could be

enlarged to an extent to receive a much larger new prosthetic

valve; (3) replacement of the previous 19 mm mechanical

prosthesis (Fig. 1) with a 23 mm ATS bileaflet mechanical

prosthesis (ATS Medical, Inc., Minneapolis, MN) became

possible; and (4) the subvalvular obstruction caused by mus-

cular hypertrophy due to prolonged valve-level obstacle was

simultaneously relieved. The patient was discharged without

any complication. As of her seventh postoperative year, she

is asymptomatic with a NYHA Class-I functional capacity

Figure 2 The left ventriculography, demonstratingremarkable myocardial hypertrophy, as well as criticalnarrowing at the annulus. The diameter is 14 mm asmeasured at the valve level.

Table 1 Patient Characteristics Summary.

Patient No. 1 Patient No. 2 Patient No. 3

Age at initial operation 19 12 10

Initial diameter (annulus/implant) 19 mm 14 mm 20 mm

Age at reoperation 23 17 22

Body surface area 1.70 m2 1.75 m2 1.72 m2

Presenting symptoms Angina, syncope Disabling angina Angina, syncope

NYHA Class Class III Class III Class III

Effective orifice area index (EOAI) 0.4 cm2/m2 N.A. 0.5 cm2/m2

Subvalvular septal muscular hypertrophy +++ ++++ ++++

Corrective procedure Konno-AVPL Konno-AVPL Konno-AVPL

Replacement device 23 mm ATSM 19 mm STJMreg 25 mm STJMreg

LV mass index (before Konno) 221 g/m2 193 g/m2 224 g/m2

LV mass index (1 year after Konno) 102 g/m2 125 g/m2 139 g/m2

Postoperative LV mass regression (%) 54% 35% 38%

Symptoms at last follow-up None None None

NYHA Class at last follow-up Class I Class I Class I

Abbreviations: NYHA, New York Heart Association; N.A., not available; AVPL, aortoventriculoplasty; ATSM, ATS bileaflet mechanical aortic valve prosthesis

(ATS Medical, Inc., Minneapolis, MN); STJMreg, St. Jude Medical Regent bileaflet mechanical aortic valve prosthesis (St. Jude Medical, Minneapolis, MN); LV, left

ventricular.

e98 K.M. Vural et al.

with a 54% reduction in left ventricular mass index (from

221 g/m2 to 102 g/m2).

Case-2A 17 year-old female patient was admitted to our institution

with chest pain, and with limited exercise capacity (NYHA

Class-III). She had undergone a coronary artery bypass graft-

ing (CABG) operation (in situ left internal mammary artery

(LIMA)-to-left anterior descending coronary artery (LAD))

with off-pump technique in another institution five years

ago, for premature coronary atherosclerosis due to a meta-

bolic defect causing significant stenosis in the proximal left

anterior descending artery. On echocardiographic examina-

tion, there was severe aortic valve stenosis with critically

elevated systolic pressure gradients across the valve (peak

140, mean 95 mmHg). Notably, the aortic annulus diameter

was only 14 mm. Her aortic stenosis was not addressed in the

previous, off-pump operation. She had remarkable left ven-

tricular hypertrophy, and critical narrowing at the annulus

(Fig. 2). The present operation started with femoral arterial

cannulation. The previously constructed LIMA-to-LAD graft

was patent. Aortic valve was highly dysplastic, and the

annulus was so narrow that any conservative attempt (val-

votomy, repair, etc.) was pointless. The native valve was

resected and, by performing a Konno type aorto-ventriculo-

plasty, a 19 mm St. Jude Regent mechanical prosthesis (St.

Jude Medical, Minneapolis, MN) was implanted. With the

septal patch included in the technique, the massively thick-

ened subvalvular septal musculature was relieved. The

patient was discharged uneventfully and her anginal symp-

toms were abruptly ended with this operation. As of her third

postoperative year, she is asymptomatic and her left ventric-

ular mass decreased from 193 g/m2 to 125 g/m2 (Table 1).

Case-3A 22 year-old female patient was admitted to our institution

with dyspnoea, chest pain and syncope-equivalent symp-

toms during physical activity, which deteriorated in the

preceding six months. Her medical history revealed an

AVR 12 years prior, when she was ten years old. At that

time, a 20 mm Medtronic-Hall monoleaflet, tilting disc,

mechanical prosthesis (Medtronic Inc., Minneapolis, MN)

Correction of Prosthesis Mismatch e99

had been implanted. This prosthetic valve apparently

became stenotic as the child grew, and the symptoms became

manifest in the following years. In line with our strategy, the

patient underwent repeat AVR with Konno-type enlarge-

ment of the annulus and outflow tract. The previous

20 mm monoleaflet mechanical valve was replaced with a

25 mm St. Jude Regent (St. Jude Medical, Minneapolis, MN)

bileaflet mechanical prosthesis. The significant post-stenotic

dilatation (6 cm) and thinned aortic wall of the ascending

aorta was dealt with concomitant ascending aorta replace-

ment with a 30 mm � 5 cm Dacron interposition graft. The

postoperative course was uneventful and the patient’s symp-

toms disappeared following the operation. At the second

postoperative year, the left ventricular mass regression

was obvious as in the previous cases, with a significant

reduction in left ventricular mass index (from 224 g/m2 to

139 g/m2; Table 1).

DiscussionThe incidence of PPM is increasing with the current liberal use

of small size (17–19 mm) mechanical prostheses in aortic posi-

tion (Fig. 1). The incidental reports denying the importance of

PPM or overstating the haemodynamic performance of small-

size prosthetic valves encourage this trend. The true incidence

of PPM is not known in many series, however reported as high

as 34–70% among AVR survivors [1,10]. In addition, currently

popularised TAVI procedures seem to be associated with a

high incidence of PPM, reported as high as 61% in some

studies [11]. While small aortic annulus represents a challenge

to the surgeon, it can be best managed at the initial operation

using relatively simple techniques. An evasive manoeuver,

such as implanting an easy-fit, but too small-diameter pros-

thesis, may result in an unsatisfactory outcome. A stenotic

prosthetic valve may cause unsatisfactory symptom relief and

left ventricle mass regression, less evident improvements in

functional capacity, life quality and life expectancy, resulting

with congestive heart failure or sudden death, as reported by

many. As later-on correction can be considerably difficult, a

preventive strategy should be adopted.

The diagnosis of ever-controversial PPM is not easy in the

absence of symptoms and signs. Echocardiography may be

misleading, especially when the valve is small and there is

subvalvular obstruction. In vague situations, the patient’s

symptoms, perhaps provoked with an exercise test, may

be informative. The EOAI may be used as a guide, as men-

tioned above; however in female, obese, and sedentary

patients, may become misleading as well [10,12]. On the

other hand, in the older, inactive population, the true benefit

of surgical correction of PPM with radical root enlargement

techniques may be limited, therefore may not be worth

risking potential mortality/morbidity. However, it appears

that active, young people having small-diameter prosthetic

valves despite a large body surface area, or patients with

poor left ventricular functions are more prone to manifest

adverse effects of mismatch. Therefore, it may be prudent to

advise that the surgeons familiar with aortic root enlarge-

ment be involved in the aortic valve operations of this par-

ticular group.

The patients with severe PPM are candidates for a future

reoperation. Unfortunately, this is often denied by cardiolo-

gists or patients themselves for the fear of increased mortality

and morbidity. Indeed, replacement of a stenotic prosthesis

with a two or three size larger one is considerably more

difficult and technically demanding. Apart from the known

risks of reoperations, the previously implanted small valve

creates a new surrounding annulus of its own size, which is

rigid enough to make some radical kind of annular enlarge-

ment mandatory in order to implant a larger prosthesis. This

enlargement should be satisfactory and also should address

the secondary subvalvular muscular hypertrophy. All these

objectives can be achieved with a Konno-type approach with

excellent early and long-term results by clinical and haemo-

dynamic means.

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