Surgical Complications

Cardiac

Most post operative patients have some degree of cardiac dysfunction. In general like most of the complications of cardiac surgery it is related to the length of bypass, myocardial preservation techniques and the operative procedure. It usually quickly recovers with supportive treatment. Diuretics are often required for a few weeks. Occasionally ACE inhibitors are also used – especially those with persistent LV dysfunction, post cavo-pulmonary shunt or establishment of a Fontan circulation.

Pericardial Effusion

Small effusions are common postoperatively. They may be due to a resolving haemo-pericardium or the post cardiotomy syndrome. The management is usually diuretics plus anti-inflammatory agents (indometacin or aspirin). Large effusions may cause incipient tamponade and require drainage.
On discharge parents should know that if their child is unwell they should immediately seek Hospital help.

Sternal Wires

These are used to ensure stability of the sternum until bony union has occurred. They are usually stainless steel wires. Removal is not necessary unless problems occur. These include pain, irritation and sometimes persistent sterile discharge. A short general anaesthetic is required for removal.

Wound

Localised wound infections can usually be treated by regular dressings and rarely require systemic antibiotics. More severe infections may require debridement and re-suturing. If deep the sternum may become unstable and require re-wiring.

Keloid formation may be a problem and can cause unsightly scarring. It may be difficult to treat.

Respiratory

Chylothorax may be due to injury to the thoracic duct drainage following cardiothoracic surgery or following percutaneous central venous access. Raised central venous pressure (e.g. following cavo-pulmonary operations) or subclavian vein thrombosis (secondary to venous lines) may also cause a chylothorax by preventing drainage of the low pressure lymphatic system. The diagnosis is made when a pleural effusion has high lymphocyte and lipid content. It may cause respiratory embarrassment and significant protein and fluid loss. Initially a chest drain is required. The dietician should be involved from the outset. The patient is placed on a minimal fat intake (1g/year age daily to a maximum of 5g) to reduce chyle flow. Monogen (SHS) is a complete formula feed used up to one year of age. In children older than one year a skimmed milk based feed with Maxijul (SMS) and Liquigen (SMS) may suffice with Paediatric Seravit (SMS) added to provide vitamins and minerals and walnut oil to provide essential fatty acids. If solids are required these must contain minimal fat. Re-introduction of fat takes place gradually when the flow of chyle has stopped for at least one month. Increase the amount of fat slowly over a period of two weeks.

If conservative treatment fails then total parenteral nutrition, allowing only water by mouth, may be successful. Ultimately a thoracotomy can be undertaken to try and identify the thoracic duct and ligate it or undertake a pleurodeisis. As a last resort the chyle may be diverted to the abdomen via a special shunt.

Prolonged collapse/consolidation may be a problem. It usually responds to physiotherapy. If the collapse is in the lower lobes consider the possibility of damage to the phrenic nerve.
Stridor & Hoarse Cry may be due to recurrent laryngeal nerve damage or tracheal stenosis following intubation. It usually improves spontaneously but an ENT opinion may be required if severe or persistent.

Neurological

Nerve damage occurs not infrequently following cardiac surgery. Phrenic nerve palsy is usually recognised only when there is difficulty extubating the patient as positive pressure ventilation masks the clinical & radiological effect of paralysis. It may produce little in the way of symptoms – especially in older children, but neonates and infants may have difficulty breathing and require plication.

Right diaphragmatic palsy

Diaphragmatic palsy post diaphragmatic plication

Recurrent laryngeal nerve damage may also cause problems. Typically following coarctation and or PDA ligation as the nerve loops around the ductus and is easily damaged. Presentation is usually with a soft voice and weak cough in a child or weak or absent cry in a baby. Care must be taken as aspiration may occur as the vocal cords cannot be adducted properly. Fortunately it usually improves with time and rarely causes a long term problem.

Cervical sympathetic plexus injury (Horner Syndrome) can occur causing ptosis, meiosis and anhydria of that side of the face. Insertion of a BT shunt is the commonest operative cause. It is usually of no consequence to the patient.

Left Horner's (of congenital rather than post surgical aetiology in this case)

Cardiopulmonary bypass and post-operative complications may cause global neurological damage. Fortunately this usually improves with time and may recover completely. A cautiously optimistic approach to counseling can thus be employed.

Renal

Renal function is often compromised in the postoperative period following cardiopulmonary bypass and often exacerbated by poor cardiac output, the capillary leak syndrome and drug therapy. It is customary for a PD catheter to be placed in the abdomen at the time of surgery to enable dialysis to be rapidly instituted if it becomes necessary.

This page was last edited 19/2/2004

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