Pulmonary Thrombo-Endartercetomy (P.T.E)
Pulmonary Thrombo-Endartercetomy -AN ALTERNATIVE TO LUNG TRANSPLANTATION?
Sign and symptoms Of CTEPH
Occlusion + increase resistance = Pulmonary Hypertension.
Decrease in pulmonary compliance = hypoxaemia and secondary polycythemia.
Increase in Right ventricular wall = Left ventricular and right coronary artery compression = Right ventricular infarction.
Failing right heart = reduction in left ventricular filling pressures with subsequent decrease in cardiac output and systemic arterial pressure.
The superior defining technique for evaluating CTEPH is pulmonary angiography that shows the extent of the disease and the decision to proceed to P.T.E. is undertaken by a chest physician and surgeon.
Pulmonary vascular obstruction is causing haemodynamically significant increase in pulmonary vascular resistance.
Proximal thrombi extending into main lobar and segmental arteries (further disease is inoperable)
No co-existing disease.
Patient and family willing to accept morbidity old procedure (currently 10%)
Median sternotomy allowing bilateral approach. Bicaval cannulation.
SVC dissected free as far as the inominate vein. Incision to the right PA, from aorta to the division of the lower lobe branches.
Endarterectomy, to dissect enough diseased endothelium thus restoring pulmonary arterial patency.
Dissection begins and continues while still on CBP, until back bleeding impairs visualization.
At 20 C distal and proximal Aortic X-clamps are applied allowing cerebral circulation (2litres/min at 40mmHg). The heart is then arrested using 4:1 blood cardioplegia.
Specific Perfusion requirements for PTE
Leucocyte depleting filter
Venous Saturation monitor
Cold circuit reservoir for cooling jacket.
Venous/Arterial temperature probes
Primed with Albumin, Mannitol, Bicarbonate, Trasylol, calcium and Heparin.
Cerebral Saturation monitor
End Tidal CO2 monitor and inline Arterial saturation monitoring
Haemodilution to Hct 20%- blood collection/ addition of Albumin
Raised CO2 during profound hypothermic period.
10 min interval warnings during arrest periods.
Reperfusion after 1st endarterectomy needs to be at SVO2 of >85% and with addition of bolus HCO3.
Re-warming gradient kept at 8-10C between water and bladder temperature.
Haemoconcentration back to 32-34%
Nasopharyngeal temp. Maintained at 37oc for 20 mins.
Slow wean off C.P.B.
PTE is a potential curative procedure for giving long term results of sustained decreases in Pulmonary Vascular resistance regression of Tri-cuspid valve regurgitation and remodeling of the right ventricle
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