Ventricular Septal Defect Closure
Updated On: July 28, 2026
Anesthetic Approaches
The infant in heart failure - a large VSD means pulmonary overcirculation, so expect a small, tachypnoeic baby with poor feeding, failure to thrive and recent chest infections. Most are on diuretics with an ACE inhibitor or digoxin, so check potassium, weight and the last feed.
Weight-based everything - dilute drug syringes dosed in mcg/kg and mL/kg, drawn up before induction, and fluids through pumps and burettes, because a careless 50 mL flush is a significant volume load in a 5 kg patient.
Pulmonary vascular resistance before bypass - oxygen and hypocarbia are pulmonary vasodilators, so a high FiO2 and enthusiastic hyperventilation drop PVR, increase the left-to-right shunt and drown the lungs. Run the lowest FiO2 that holds saturation, PaCO2 high-normal.
Full saturation as a warning - a saturation of 100% in this baby is not a win. It means PVR has fallen, the shunt has grown, and pulmonary flow is stealing cardiac output from the systemic circulation.
Induction as a hemodynamic decision - inhalational uptake is essentially unchanged with a left-to-right shunt, so a parent-present sevoflurane induction suits a stable child, while a decompensated infant or an adult goes IV and cardiostable.
Air discipline on every line - this is an open intracardiac communication and even a small bolus of air can cross to the systemic side and reach the coronaries or brain. Filter every infusion, purge stopcocks, and never flush a line you have not cleared.
Pulmonary hypertensive crisis - PVR spikes acutely, the right ventricle fails and cardiac output collapses. The triggers are predictable: hypoxemia, hypercarbia, acidosis, hypothermia, pain, light anesthesia and endotracheal suctioning.
Pre-empting and treating a crisis - deepen before you stimulate, give extra opioid before suctioning, and have inhaled nitric oxide or prostacyclin rigged and tested. Treat with hand ventilation on 100% oxygen, the vasodilator and right ventricular support.
Complete heart block - the conduction bundle runs along the posteroinferior rim of a perimembranous defect and a suture close to it can produce transient or permanent block. Confirm epicardial pacing wires before separation, have the pacing box checked and set, and know the underlying rhythm.
Post-bypass TEE - color Doppler across the septum plus a saturation step-up between right atrium and pulmonary artery says the patch is leaking, and a meaningful residual shunt means going back on bypass now. Look at the tricuspid and aortic valves too.
Temperature and glucose - an open chest loses heat fast and hypothermia worsens acidosis, coagulopathy and PVR, so warm the room and control rewarming on bypass. Glycogen stores are limited, so check glucose regularly.
Bypass prime and heparinization - the prime is a large fraction of an infant's blood volume, so settle its composition, target hematocrit and the antifibrinolytic regimen with perfusion beforehand. Heparin is about 300 to 400 units/kg, with the clotting time confirmed before cannulation.
Post-infarction VSD in an adult - cardiogenic shock days after infarction, often already on a balloon pump, with the shunt on an infarcted ventricle. Induction is where they die, so go slow and cardiostable with vasoactives running first, and expect right ventricular failure and prolonged support. Treat the transfer to ICU as part of the case.
Emergence plan and handover - decide in advance between early extubation in a well child and an intubated transfer on infusions; long bypass, pulmonary hypertension or an open sternum go to ICU sedated. Hand over pacing settings, rhythm, residual shunt and the PVR plan.
Tucked Arms (general considerations): Consider a second IV – once the procedure has started, it's going to be VERY difficult to handle IV issues – especially if your only IV has problems. Ensure the IV is running and monitors are still functioning after tucking the patient's arms.
Long procedure (general considerations): Procedures anticipated to last longer than 2 hours generally require a urinary catheter. Also, consider checking lines and positioning regularly as the risks of infiltration and nerve damage are increased with procedure time. Consider an IV fluid warmer and a forced air warmer to keep the patient euthermic.
High post-operative pain (general considerations): Plan ahead to treat pain in the postoperative period. If not contraindicated, consider hydromorphone or other long-acting analgesics along with adjuncts such as Ofirmev and/or toradol. Where possible, give during the operative period to limit pain in the postoperative period. Where applicable, consider peripheral nerve blocks and/or epidural interventions.
Fluoroscopy / Xray (general considerations): Have lead aprons and thyroid shields available. Alternatively, distancing yourself 3 to 6 feet will reduce scatter radiation to 0.1% to 0.025% respectively. Occupational maximum exposure to radiation should be limited to a maximum average of 20 Sv (joules per kilogram - otherwise known as the Sievert/Sv) per year over a 5 year period. Limits should never exceed 50 Sv in a single year.
Arterial line (general considerations): Preoperatively check pulses to gauge the best side to attempt the A-line. Perform an Allen test to ensure adequate blood flow. Have the A-line equipment set up and ready in the room.
Off-site (general considerations): Extra precaution should be taken preoperatively if the surgery is planned off-site (away from the OR or your normal work spaces). Depending on your facility setup, it's wise to take emergency airway equipment and drugs with you that would be necessary to treat the gamut of anesthesia emergencies.
Bispectral Index Scale (BIS) monitor (general considerations): The recommended values under general anesthesia are 40-65. Values of 65-85 are recommended for sedation.
A ventricular septal defect (VSD) is a hole in the interventricular septum and the most common congenital cardiac anomaly. Left ventricular pressure exceeds right, so blood shunts left to right in proportion to the size of the defect and the ratio of pulmonary to systemic vascular resistance. A large, nonrestrictive defect floods the pulmonary circulation and volume-loads the left atrium and left ventricle, which is why the infant presents with tachypnea, poor feeding, failure to thrive, and recurrent chest infections rather than with cyanosis. Sustained overcirculation remodels the pulmonary arterioles; once pulmonary vascular resistance exceeds systemic, the shunt reverses and the child becomes cyanotic - Eisenmenger physiology, which is irreversible and takes closure off the table. Perimembranous defects sit against the aortic valve and the conduction bundle. In adults, septal rupture after myocardial infarction produces the same shunt acutely on an already failing ventricle.
Approach - median sternotomy. Pericardium is opened and a patch of it is often harvested to close the defect.
Cannulation and bypass - systemic heparinization, then aortic and bicaval venous cannulation for cardiopulmonary bypass (CPB) with moderate hypothermia. Deep hypothermia with circulatory arrest is reserved for the smallest neonates, where cannulae get in the way of the repair.
Cardioplegic arrest - aortic cross-clamp applied and cardioplegia delivered, giving a still, bloodless septum to work on.
Exposure - right atriotomy, with the tricuspid leaflets retracted (and sometimes detached and re-suspended) to bring the defect into view. Supracristal defects are exposed through a pulmonary arteriotomy; some apical or inferior muscular defects need a right ventriculotomy.
Patch closure - a Dacron, Gore-Tex, or autologous pericardial patch is sutured over the defect. Sutures are kept deliberately off the posteroinferior rim of a perimembranous defect, where the conduction bundle runs, and away from the aortic valve cusps.
De-airing and reperfusion - atriotomy closed, standard de-airing maneuvers performed, cross-clamp released and the heart reperfused.
Pacing wires and monitoring lines - temporary epicardial ventricular (often atrial as well) pacing wires are placed, and the surgeon may place transthoracic right atrial, left atrial, or pulmonary artery lines.
Separation from bypass - weaned with inotropic support as needed, transoesophageal echocardiography (TEE) used to look for residual shunt, tricuspid and aortic regurgitation, and ventricular function. Protamine given, decannulation, hemostasis.
Closure - chest tube in the pericardial space and sternal wiring. In a small or edematous infant the sternum may be left open under a patch and closed in ICU a day or two later.
Variant routes - transcatheter device closure in the cath lab for selected muscular defects; pulmonary artery banding as palliation for a Swiss-cheese septum with later definitive closure; in adults, post-infarction septal rupture repaired with an exclusion or infarct-excluding patch, often on an intra-aortic balloon pump.
Once the patch is in, the physiology flips. The pre-bypass rule of keeping PVR high to limit the shunt is obsolete the moment the septum is closed, and after bypass you want PVR low to unload a right ventricle that has been working against a reactive pulmonary bed. Say the change out loud at separation so the whole room, and later the ICU, is running the same plan.