Valvular surgery

Valvular surgery

Timing is important

Mitral surgery

· severely stenosed valve

· paroxysmal nocturnal dyspnoea

· pulmonary oedema

· significant pulmonary hypertension

Aortic surgery

· aortic pressure gradient > 50 mmHg

· severe left ventricular hypertrophy

· increased pulmonary hypertension

Myocardial revascularisation

Myocardial revascularisation is accomplished using reversed saphenous vein coronary artery bypass grafts and internal mammary artery bypass grafts. The decision of which method to use depends on age, pre-morbid status, prior surgical procedures, the number of vessels to be grafted and the adequacy of the saphenous vein or the internal mammary artery (IMA).

Advantages of IMA

· longer duration of patency

· no leg incision

Disadvantages of IMA

· extensive dissection of the IMA from the thoracic wall

· prolongation of operative time

· higher incidence of bleeding

· higher incidence of respiratory complications (basal collapse)

· higher incidence of sternal wound infection (devascularised sternum especially if bilateral IMA)

Procedure

· the saphenous vein is harvested and tested for patency

· the vein is reversed

· the vein is anastamosed to the distal portion of the diseased coronary artery

· the vein anastamosed to the ascending aorta (top end)

· if the internal mammary is to be used it is dissected from the chest wall and prepared in the same manner

· skip grafting may be used for multiple lesions in one artery

On completion of myocardial revascularisation

· the CPB is weaned off

· the left ventricle is vented

· mediastinal, pericardial and pleural chest tubes are placed

· wires are used to approximate sternum

Octopus (minimaly invasive CAS)

Advantages

· less invasive procedure

· no CPB

· <>

· <>

· fast tracking

· <>

· <>

Indications

· single/double blocks

· good runoff

· angioplasty failure/unsuitability

· high risk patients (renal failure, redo, COPD)

· combination

Contraindications

· multiple blocks

· site of blockage (too difficult to access)

· calcification

· diffuse disease

· endarterectomies

· intramyocardial arteries

· lack of surgical expertise (experience with this procedure)

Special considerations

· maintaining haemodynamics

· ischaemic preconditioning

· confirmation of patency

· early 12 lead ECG

Disadvantages

· ? long term patency

· steal syndrome

· learning curve

· applicability

· technically demanding

Limitations of myocardial revacularisation

· diffuse distal disease

· vessels too small

· vessels inaccessible

NB. Intra/post-operative coronary angioplasty may be indicated for vessels unable to be grafted due to the above.

Thoracic procedures

Minor procedures

Video assisted thoracotomy and pleurodesis

Thoracotomy – wedge resection

Major procedures

Thoracotomy – lobectomy

Pneumonectomy

Bilateral lung volume surgery

Care of patients following thoracic surgical procedures

Airway

On arrival from theatre the patient care nurse must immediately assess patency of airway

· the airway must be maintained using guedell airway and jaw support

· all patients must have supplemental oxygen

· SaO2 monitoring is mandatory

· ABG is indicated in patients with compromised airway

· gross hypoventilation/hypoxaemia is indicative of intubation and ventilation

NB. The anaesthetist must remain with patient until airway patent.

Complications

Sputum retention

· adequate pain relief must be maintained

· efficient deep breathing and coughing must be maintained

· humidification should be employed if sputum tenacious

· 2 hourly deep breathing & coughing

· bronchodilator therapy as indicated

· method of pain relief must be carefully selected (intravenous narcotics, subcutaneous narcotics, PCA, epidural analgesia)

· significant respiratory depression must be avoided

· frequent changes in position are important