Insertion of a dedicated vent usually requires a separate cardiotomy. Venting also can be conveniently done through the surgical cardiotomy for eg via the aorta in case of AVR or the LA in an MV Repair or MVR. Most problems of insertion are usually due to an inadequate opening or due to perforation of the posterior wall of the structure in which the vent is being passed.
Difficulty in insertion is usually due to an inadequately large purse string or failing to incise the pulmonary vein endothelium and only incisng the pericardium. There have been rare cases of bronchial injury when an overenthusiastic incision or forceful thrusting of the vent has been done. It is important to place the purse string such that the horizontal component is well placed so that on tightening it does not produce a channel due to infolding through which continued bleeding can occur after tightening the purse string.
Pulmonary artery VentEdit
A common error is to try to place this vent on full bypass. This causes the PA to collpase and thus increasing the chance of posterior perforation and also causes difficulty in insertion of the vent.
Aortic Root VentEdit
The cardioplegia needle can also be used as a vent. Problems of insertion can occur if there is an atherosclerotic plaque and this can be avoided by Epiaortic screening. Dissections can occur if this vent is improperly positioned and also if the lateral eye of the cardioplegia needle is murally placed instead of being intraluminal.
LV Apical VentEdit
The correct method of creating an apical cardiotomy for a vent is to lift the apex on CPB and then place an epicardial incision. The tip of a dissecting forceps or an artery forceps is then passed into the muscle and into the LV cavity. IT IS IMPORTANT TO SELECT AN AREA DEVOID OF FAT. Failure to do this can cause a major problem in hemostasis at the end of surgery.The vent is then introduced carefully. This vent can be used for apical saline insufflation during miral valve repairs and canbe the troute of insertion of a transapical perfusion cannula through the aortic valve to perfuse the true lumen in an aortic dissection.
Trans PFO/Interatrial septumEdit
Usually this is not a problem unless the PFO/ stab incision is not wide enough.
Difficulty is mainly technical. An Endo vent is passed exactly like a Swan Ganz and acts as an Endo PA Vent. The heart port Endoballoon occluder has a port that can be used as a vent. These devices need TEE/fluoroscopy to help in placement and confirm their position.Kinetic assisted drainage or vacuum assisted drainage may be benefical in these cases.