Cardiovascular Journal of Africa: Vol 26 No 4 (July/August 2015)

CARDIOVASCULAR JOURNAL OF AFRICA • Volume 26, No 4, July/August 2015

198

AFRICA

Pre-dilation and pre-stenting was performed in all three cases.

This was achieved using BIB

(NuMED, Hopkins, NY, USA)

balloons and bare-metal stents (IntraStent

LD Max

, ev3

Endovascular, Plymouth, USA) in cases 1 and 2. Both patients

needed only one pre-stent to obtain a stable RVOT with no recoil

of stent during balloon deflation and no residual stenosis.

Case 3 was more complicated due to the direct retrosternal

position of the RVOT. The RVOT was severely calcified

and residual stenosis and recoil of a 45-mm covered CP

stent (NuMED, Hopkinton, NY, USA) using a 22-mm BIB

warranted a second stent implantation to secure a stable landing

zone. This was achieved using a 36-mm IntraStent

LD Max

(ev3 Endovascular, Plymouth, USA) on a 22-mm BIB

. Residual

indentation of the stents was abolished using a high-pressure

balloon (Bard Atlas

PTA dilatation catheter, Bard Peripheral

Vascular, Tempe, AZ, USA) (Fig. 3).

Once RVOT rehabilitation was completed, the Melody

valves were successfully implanted. Patient 3 needed post-valve

implant dilatation due to the residual stenosis and gradient.

Post-stent implantation gradients were measured using a Multi-

track

angiographic catheter (NuMED, Hopkinton, NY,

USA). At the time of implantation, the decision was made

that the results were satisfactory and no further dilatation was

indicated. Melody

valve implantation was successful in all three

patients, with reduction of RVOT gradients and elimination of

the PR (Fig. 5).

Post valve implantation coronary angiograms were

normal with no vessel obstruction. There were no ischaemic

changes on ECG for 48 hours and no pericardial effusion on

echocardiography. The patients were observed overnight and

discharged home within 48 hours.

The patients have now been followed up for two years and

demonstrated RV size and function improvements with normal

pulmonary valve function. Subjectively all patients reported

improved exercise tolerance.

Discussion

Percutaneous pulmonary valve implantation has become an

accepted alternative to surgical pulmonary re-valvulation, with

low morbidity and mortality rates.

4,5

More than 7 000 Melody

valves have been implanted in 156 centres worldwide, and these are

the first cases in Africa (direct correspondence with Medtronic).

Indications for percutaneous valve implantation are identical

to surgical indications. Classic indications for Melody

valve

implantation include: patients above 20 kg, conduit dysfunction

with stenosis or moderate regurgitation, conduit size

16 mm

and

22 mm, and favourable RVOT morphology.

4-8

Contra-

indications consist of active endocarditis and a conduit size that

is incompatible with the valve size.

4,7

Helpful information obtained from CTA includes the

anatomical aspects of the RVOT and its spatial relationship to

the coronary arteries. The risk of coronary artery compression

is the most frequent exclusion factor and cause of procedure-

related deaths. Major procedural complications include

dislodgement of the valve, coronary artery compression, rupture

of the homograft, and haemothorax due to pulmonary artery

perforation. Follow-up complications include stent fracture and

endocarditis.

4-6,8,9

Stent fracture rates diminished after the practice

of presenting became common place.

Case 3 demonstrates that percutaneous valve implantation

may be a useful alternative to surgery. The transient chest pain

in this patient was secondary to RVOT stretching and similar to

that of surgery. The benefits of percutaneous valve implantation

include short hospital stay and no ICU care. The availability of

these valves may reduce the duration of RV dysfunction and the

total number of RV–PA conduit replacements.

Conclusion

Introduction of the Melody

valve has been proven a safe

and effective alternative to surgery for RVOT re-valvulation.

Fig. 4.

Simultaneous inflation of a compliant balloon (small

arrow) in the RVOT and coronary artery angiogram

(large arrow) with no coronary artery obstruction.

Fig. 5.

Melody

valve competency was demonstrated using a

Multi-tract

catheter.