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Pulmonary Valve Disease

a)Pulmonary Stenosis

The obstruction may be valvar, infundibular or supra valvar.

Indications for Surgery

Congenital pulmonic stenosis is the most common lesion requiring relief. Very rarely it could be due to rheumatic involvement along with disease of other cardiac valves. Carcinoid syndrome can cause thickening and fusion of the valve cusps and also produce outflow obstruction. Extrinsic pulmonary obstruction could be caused by cardiac tumors or aneurysm of sinus of Valsalva.

Quantification of Pulmonary Stenosis
Quantification by ECHO

By Valve area

Mild > 1.5 cm 2

Moderate 0.5-1.5 cm 2

Severe ~ 0 . cm

By Peak pressure gradient

Trivial < 25 mms of Hg

Mild 25-50mms of Hg

Moderate 50 -80mrns of Hg

Severe > 80 mrns of HgNeonates presenting with critical pulmonary stenosis and intact ventriculai.septum usually present within two weeks and need urgent treatment.

Pulmonary stenosis may be present in infants, children or adults. Mild stenosis can be left alone and followed up. Moderate stenosis is treated at the time of surgery of associated lesions. If the stenosis is severe and isolated, it has to be treated by balloon valvotomy.

Types of Surgery

Open Pulmonary Valvotomy


Open pulmonary valvotomy by technique of inflow occlusion is done without cardio pulmonary bypass. Surface hypothermia is used and illflow occlusion(SVC and IVC) aild vertical pulmonary arteriotoiny is done. Fused pulnlonary valve commissures are divided upto their attachment at pulmonary annulus.

The incision is done with a knife as much as possible as one is not worried even if it produces mild regurgitation. These days valvotomy is done on CP bypass.

Pulmoltary Valvotolny 012 Cardio ~ u l m o r t a Bypass

Patient is connected to cardio pulmonary bypass using ascending aortic cannula and single 01- double (prefersed) venous cannulae. Aorta is not clamped and cardioplegia is not givcn. On an empty beating heart. vertical pulmonary arteriotoiny is done and [used colnmissures ase inciscd upto the annulus. In some cases, the fused commissures are also attached to the wall of pulinonary artery. The commissures are released from the artery by sharp dissection and one can incise the conmissures for another 2 or 3 mms.

Pulmonary Valwto~ny oiz Car& Pulrnorzary Bypass and use of Cardioplegia Single aortic ca~~nulation and separate SVC and IVC cannulation arc donc.The cavae are snared to have total cardio pu1mona1.y by pass. Aorta is clamped and root cardioplegia is administered to achieve cardiac arrest.Vertical pulmonaiy arteriotoiny and pulmonary valvotomy arc done. Small right atriotomy is done and ASD or PFO, if present is closed. Pulmonary ateriotomy is closed with 6'0' .or '5' prolene sut~~res.

Pulmonary Valvotomy with Infirzdibular Resectiorz
Infundibular obstruction in cases of pulmonary valvar stenosis could be primary or secondary. 11' this obstn~ction is significant, surgical resection has to be done at the time of pulinonary valvotomy. It can be done tl~rougli the right atrium after retracting the tiicuspid valve or trans pulinonasy after retracting that valve or through a sinall vertical right ventriculotoiny. After ventriculas resection vertical ventriculotoiny is sutured either dircctly or with a small pericardial patch.

Open pzllmonary Valvotonzy, b;fundibular Resection and Trclrzs Annulai. Patch The pulmonary annulus may be narrow based on pre-operative investigations and on measurement with Hegar's dilator after valvotomy. The pulmonary arteriotomy incision is extended across the annulus on to the infundibuluin for 2 or 3 cms. Pulmonary valve cusps are excised leaving the posterior cusp, if it is normal. Hypertrophied infundibular muscle is excised. 111 babies, this resection- is kept to a minimum. A fresh or gluteraldehyde treated pericardial patch is then sutured to the right ventriculas outflow using 5 '0' prolcne sutures.

Results

In critical pulmonary stenosis in infancy, surgical mortality is 6 per cent. For children and adults with isolated pulmonary valve stenosis, the mortality approaches 0 per cent.

b)Pulmonary Regurgitation

Most of the clinical cases are after balloon valvotomy or surgical valvotomy using a trans annular patch. It can be quantified by Echocardiography and Doppler.

 
Indications for Surgery

Patients usually present with fatigue, dyspnoea and ventricular arrhythmias. If they have additional tricuspid regurgitation, pulmonary valve replacement should be considered. After correction of Tetralogy of Fallot the progression of pulmonary regurgitation is time related and depends on other lesions like RV obstruction or residual ventricular septa1 defect.

In the Toronto experience, 1-2 per cent of patients after coirection of Tetralogy required re-operation after a mean interval of 12 years. 66 per cent of them had a trans annular patch and they required pulmoilary valve replacemeat.

Types of Surgery

Pulmonary valve replacement using pulmonary or aortic allograft is the procedure of choice. It increases R.V. ejection fraction, decreases R.V. end diastolic pressure and improves symptoms.

Operative mortality is low - 1-2 pkr cent.

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