Problems related to vents after removal are usually related to bleeding , stenosis of tubular structures and rupture / pseudoaneurysms at vent sites. Bleeding can be avoided by appropriate purse strings and reinforcing all vent sites with a second suture which may need to be at times pledgeted. PA , Aortic root and LV Apical vents need to be particularly reinforced as they are at higher pressures.
The pulmonary artery vent especially needs to be particularly carefully closed as this can be exposed to sudden high pressures when coughing even if there is no pulmonary hypertension. LV apical venting sites need to be inspected at 50 % cardiopulmonary bypass so that any bleeding can be tackled by immediately going back on CPB. If CPB is to be avoided or not available for any reason the heart may be elevated using either packs or a DPRS suture used in OPCAB - but suturing a full beating bleedingheart is to be avoided. At times a limited left thoracotomy may be used.The presence of a mitral prosthesis mandates that the heart must not be lifted up to control the bleeding without decompressing it (using CPB) when approaching it from median sternotomy for fear of LV rupture. The aortic root vent site can be a place of troublesome bleeding as the ejectile force of the LV is usually directed towards it. A Thin aorta especially associated with post stenotic dilatation of AS can be a potent cause of bleeding. This cna leasdd todissection or further tearing. Sutures on this type of aorta are better placed on CPB with transient lowering of flows or by lowering the pressures transiently by giving boluses of sodium nitroprusside or elective cardiac fibrillation - defibrillation. Tears that extend may require cross clamping , debriding the margins of the tear and placing a pericardial / prosthetic patch rather than repeated futile attempts at direct closure.
Psuedoaneurysms can occur and these may need to be tackled on CPB and resection and patching of the pseudoaneurysm may be required.