Sutureless Repair of Left Primary Pulmonary Vein Stenosis — A Case Report

Primary left pulmonary vein stenosis is a very rare condition. It is associated with variable form of Pulmonary artery hypertension. Catheter based intervention is used to treat the disease like balloon dilation and stenting but this has high recurrence rate. Here is a case in which we did a sutureless repair of left pulmonary vein thus decreasing the possibility of recurrence. Sutureless surgical management is technically superior and less challenging than direct left atrial wall anastomosis and it provides better results than catheter based intervention in terms of recurrence of stenosis.


Introduction
Primary Pulmonary vein stenosis (PVS) occurs due to developmental aberrations in the incorporation of pulmonary veins into left atrial wall.It is a very rare anomaly and is present in 0.5% of autopsy in children.It may manifest as isolated lesion or associated with other cardiac defects (more than 50% of cases).Though the catheter based interventions like balloon dilation, stent insertion, excision of stenotic segment, patch grafting are used to correct such stenotic lesions, the re-stenosis rates are higher than the sutureless surgical management.We present a case, who underwent surgical sutureless repair for left side primary pulmonary vein (LSPV) stenosis and had an uneventful post operative recovery with no residual stenosis.

Case Report
A 4 year old female child, 14 kg was admitted for dyspnea, tachypnea and cya-nosis.Her SpO2 was 88%, heart rate 130 beats/min, systolic blood pressure 90 mmHg, and respiratory rate 45 per minute.The second heart sound was accentuated, while grade 2/6 pan-systolic murmur was audible over the lower left sternal border.Her jugular vein was distended and the liver was palpable 4 cm below the right costal margin complete blood count, electrolytes, renal, and hepatic profiles are normal.Chest X-ray showed marked pulmonary venous congestion with cardiomegaly (Figure 1).
Trans thoracic Echocardiogram (TTE) showed mild pulmonary hypertension (PAH) with a dilated right ventricle, bilateral shunting across the atrial septal defect (ASD) with obstructed left side pulmonary veins opening to left atrium.CT pulmonary angiography showed long segment LSPV stenosis (Figure 2 (a), Figure 2 (b)).
Patient was operated on cardiopulmonary bypass with cold cardioplegic arrest.Heart was retracted to right chest cavity.Incisions are made in the left atrium and extended to the base of left atrial appendage and in the left pulmonary venous confluence extended to both superior and inferior pulmonary veins across the stenosed segment (Figure 3 (a), Figure 3 (b)).
The divided edge of the atrial wall is then sutured to the pericardium (not the pulmonary vein) in a suture line remote from the divided edge of the pulmonary veins using a running 5 -0 non-absorbable suture.The suture line is technically easy to sew and hemostatic challenges are less as it connects the left atrial edge to the pericardium in a circle around the pulmonary veins and the suture line ignores the complex shapes of the pulmonary vein incisions.Pericardial patch closure of ASD done through right atriotomy.
Postoperatively, patient recovered well, extubated on 2 nd Post operative day with SpO2-100% and discharged on 7 th postoperative day.Post operative Cardiac CT scan revealed pulmonary vein confluence opening into left atrium with no residual stenosis with an intact neoatrial septum (Figure 4).Post operative TTE revealed mild Pulmonary artery hypertension (PAH) with non obstructive flow across the anastomosis.In our patient we did this procedure and postoperative result were good.Patient did not develop restenosis in 1 year follow up.

Discussion
Primary PVS is a rare disease.In such cases, patient becomes symptomatic because of pulmonary edema and hypoxemia resulting from increased hydrostatic pressure in the pulmonary venous system, which in turn triggers an increase in pulmonary vascular resistance and further worsen the symptoms.This vicious cycle is remarkable in first few years of life as the pulmonary vascular recruitment is very limited even in patients of unilateral disease.Patients present initially with tachypnea and recurrent pneumonia and with the progression of disease patient may develop a new murmur, right ventricular failure and pulmonary edema.Patient may develop failure to thrive and hemoptysis [1].Our patient had unilateral

Conclusion
A high index of clinical suspicion should be made for PVS in patients presenting with symptoms of PAH.Once the diagnosis is made, management is primarily surgical.Sutureless surgical management is technically superior and less challenging than direct left atrial wall anastomosis and it provides better results than catheter based intervention in terms of recurrence of stenosis.

Figure 1 .
Figure 1.Chest X-ray showing marked pulmonary venous congestion with cardiomegaly.

Figure 3
Figure 3 (a) Showing Incisions made in the left atrium and extended to the base of left atrial appendage and in the left pulmonary venous confluence extended to both superior and inferior pulmonary veins across the stenosed segment; (b) Pictorial presentation of incisions made in the left atrium and extended to the base of left atrial appendage and in the left pulmonary venous confluence extended to both superior and inferior pulmonary veins across the stenosed segment.

Figure 4 .
Figure 4. Post operative Cardiac CT scan revealing pulmonary vein confluence opening into left atrium with no residual stenosis with an intact neoatrial septum.