Case report
A 1-year-old patient was brought into our hospital with easily induced fatigue and dyspnoea. About 6 months earlier, at another hospital, the patient had undergone pulmonary balloon valvotomy twice in 3 months owing to pulmonary stenosis. At the current examination, auscultation revealed a systolic ejection and regurgitant murmur. Transthoracic echocardiography revealed severe pulmonary stenosis and insufficiency that was due to prolapse and incomplete coaptation of the leaflets of the pulmonary valves. Pulmonary artery valvular transgradient pressure was 100 mmHg and mean pressure was 51 mmHg. The other echocardiographic findings were as follows: a left ventricular ejection fraction of 0.60, normal-sized left chambers, enlarged right chambers, and a dilated main pulmonary artery after stenosis.
Standard cardiopulmonary bypass was performed. After pulmonary arteriotomy, we saw right pulmonary leaflet perforation from the commissure line adjacent to the anterior pulmonary leaflet, anterior leaflet seemed thickened, and there was perforation from the adjacent commissural line of the right pulmonary leaflet. The left pulmonary leaflet seemed thickened and retracted. Because of the near-normal morphology of the leaflets, we made the decision to repair them. The incision was extended from the basal mid cusp line of the anterior leaflet to below the annulus to provide adequate enlargement of the right ventricular outflow tract. Enlargement of the pulmonary annulus remained under control via passing a hegar bougie (13 mm), which was calculated in accordance with the body surface area. Polytetrafluoroethylene was used as a patch. Patch size to enlarge the anterior leaflet and right ventricular outflow tract was estimated by using the hegar bougie. Right pulmonary leaflet was repaired using a 0.1-mm polytetrafluoroethylene patch. The left pulmonary leaflet was opened towards the annulus level, and the 0.1-mm polytetrafluoroethylene patch was used to enlarge the coaptation zone (Fig 1). Perioperative pulmonary artery was then filled with saline solution so as to complete the assessment of the leaflets. After the operation, control transthoracic echocardiography showed minimal pulmonary insufficiency. As well as 18 mmHg gradient at the pulmonary artery was detected with decrease in the size of the right chambers and it showed an improved left ventricular systolic function. After this, the patient was discharged without any problems. During the 1st month’s control, echocardiography revealed a 15-mmHg gradient at the level of the valve and 1st-degree regurgitation (Fig 2).
Discussion
Congenital pulmonary valve stenosis is a common CHD. Isolated pulmonary valve stenosis comprises 8–10% of all the CHDs.Reference Moss and Adams 1 Valvar stenosis is the most common type of pulmonary stenosis, and is typically characterised by fused or absent commissures with thickened leaflets of the pulmonary valve.Reference Moss and Adams 1
Surgical treatment was the only option for valvular pulmonary stenosis before the use of balloon angioplasty.Reference Kan, White, Mitchell, Andersen and Gardner 2 The surgical approach evolved from closed valvulotomy, which was first performed in 1948, to open valvulotomy using inflow occlusion, and finally open valvulotomy with the use of cardiopulmonary bypass.Reference Brock 3 With the latter technique, the extent of surgery can be adapted to the needs of each individual patient and can vary from a simple commissurotomy to a complete right ventricular outflow tract reconstruction. Between 2–4 years of age is the most ideal age for pulmonary valvuloplasty, and the ideal age for surgery is 5–12 years.Reference Yadav 4
While surgically recognising potential advantages of a less invasive approach, the first attempts at percutaneous catheter-based dilation of stenotic pulmonary valves were performed in the 1950sReference Rubio-Alvarez, Limon and Soni 5 , Reference Rubio and Limon-Lason 6 . Balloon pulmonary valvuloplasty has significantly improved and the approach has become the standard of care for treating pulmonary valve stenosis.Reference Rao 7
Although pulmonary valvuloplasty remains the preferred treatment for isolated pulmonary valve stenosis, it is not definitive therapy in the setting of complex CHD. However, it can occasionally be applied to these more complex patients as a palliative treatment until more definitive surgical repair can be performed.
The mortality and major complications rate of transcatheter balloon valvuloplasty have been found in range between 0.24 and 0.35%, respectively, in a multi-centre study.Reference Stanger, Cassidy, Girod, Kan and Lababidi 8
Recurrent pulmonary valve stenosis is observed in the frequency of 8--14% after initial interventionReference Karagoz, Asoh, Hickey, Chaturvedi and Lee 9 , Percentage of re-intervention as high as 30% was noted in neonates compared with older children who are mostly suffered from re-stenosis. The incidence of pulmonary valve regurgitation after pulmonary balloon valvuloplasty is reported to be between 41 and 88%.Reference Karagoz, Asoh, Hickey, Chaturvedi and Lee 9 , Reference Rao, Galal, Patnana, Buck and Wilson 10 Our patient had severe pulmonary insufficiency after balloon valvuloplasty owing to the incomplete coaptation of the leaflets.
Because of higher percentage of re-stenosis after transcathater balloon valvotomy in neonates and young children, surgical valvotomy has been the preferred treatment for pulmonary valve stenosis in most occasions. Here we reported a 1-year-old infant who had balloon re-intervention twice. After transcatheter balloon valvuloplasty, she had severe pulmonary regurgitation and recurrent stenosis. She approximately had 100 mmHg transvalvular pulmonary valve gradient, and thus we had to operate as soon as possible.
Especially dysplastic pulmonary valves are resistant to balloon valvuloplasty and simple valvotomy is usually not enough. Occasionally, transannular patch is required to relieve the right ventricular outflow tract obstruction but it might cause significant pulmonary insufficiency. In the long term after valvotomy, freedom from re-stenosis is excellent.Reference Hayes, Gersony, Driscoll, Keane and Kidd 11 Nonetheless, severe pulmonary insufficiency is common and ranges between 57 and 90% in different studies.Reference Hayes, Gersony, Driscoll, Keane and Kidd 11 , Reference Nugent, Freedom, Nora, Ellison and Rowe 12 In our patient’s situation, three cusp augmentations prevent pulmonary insufficiency.
When correcting pulmonary stenosis or insufficiency, most surgeons use a homograft or xenograft; however, they sometimes use a mechanical prosthesis or a self-expanding stented valve.
Leaflet augmentation, valved homografts, and xenografts were proposed as the most anatomic and physiologic ways to resolve right ventricular outflow tract stenosis and insufficiency, but all will eventually need replacement because of patient growth and conduit deterioration.Reference Sano, Karl and Mee 13 Pulmonary allografts were extensively used for right ventricular outflow tract reconstruction. They were not always readily available, were less durable, and developed higher degrees of pulmonary stenosis particularly in patients under the age of 2 years. Children with allograft right ventricular outflow tract reconstruction frequently required early valve reoperation.Reference Homann, Haehnel and Mendler 14
The use of a monocusp valve created from pericardium, xenograft valve cusps, fascia lata, autologous pulmonary artery wall, or polytetrafluoroethylene has been shown to decrease short-term pulmonary insufficiency.Reference Gundry, Razzouk, Boskind, Bansal and Bailey 15 However, even the monocusp has limited durability. Gundry et alReference Gundry, Razzouk, Boskind, Bansal and Bailey 15 reported that by 24 months only 14% of their patients with a homograft monocusp-bearing transannular patch had a competent valve despite excellent short-term function. Similarly, in a report from the University of Indiana, most of the patients had deterioration of the polytetrafluoroethylene monocusp valve function by the 3rd year, even though the valve function was still better when compared with the free pulmonary insufficiency experienced by the patients with a transannular patch. However, Sasikumar et alReference Sasikumar, Sasidharan, Tharakan, Dharan, Mathew and Karunakaran 16 reported that calcification and loss of mobility were observed in a significant number of patients 1 year after the operation.
Bileaflet hand-sewn pulmonary valves were seen in previous publications; polytetrafluoroethylene (PTFE) patches may be preferable in the augmentation of heart valves in this age group because of its ease of use. Their shape and size allow placement in young children with a reasonable expectation that they will remain competent with growth of the native annulus and not require replacement.Reference Nunn, Bennetts and Onikul 17 Hand-sewn pulmonary valve augmentation with PTFE is more durable at long-term follow-up.
The augmentation of the three pulmonary valve cusps with polytetrafluoroethylene is simple, it does not significantly prolong the operation, reduces the degree of pulmonic regurgitation in the immediate postoperative period, and improves the early outcome. However, our technique presented here reduces pulmonic regurgitation while avoiding risks such as calcification associated with the use of homografts and heterografts. Use of a polytetrafluoroethylene augmentation of all pulmonary valves prevent short-term pulmonary valve insufficiency and significantly reduces long-term pulmonary valve insufficiency. It is inexpensive, easy to construct, and demonstrates no evidence of stenosis, calcification, or embolisation. Despite slightly longer cardiopulmonary bypass times, it reduces ICU stay and minimises operative morbidity and mortality.
Acknowledgements
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This research received no specific grant from any funding agency, commercial, or not-for-profit sectors.
Conflicts of Interest
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Ethical Standards
The authors assert that all procedures contributing to this work comply with the ethical standards of the relevant national guidelines and with the Helsinki Declaration of 1975, as revised in 2008, and has been approved by the institutional committees (Boston Children’s Hospital).