Makindo Medical Notes.com

Elective Operative mortality is approximately 2%, but this is increased in patients with IHD (when it is usually combined with CABG), lung disease and the elderly.

About

• Cardiac valves both tissue and metal are used to replace diseased, damaged and infected valves
• May be metal valves or tissue valves (Xenografts and allografts)

Xenografts and allografts

• Either from pig or bovine heart
• Generally do not require lifelong anticoagulation
• Remain functional for 10-15 years so maybe preferred in elderly
• Porcine aortic tissue valves usually produce no abnormal added sounds.
• Porcine mitral may cause a diastolic flow murmur and opening snap.

Mechanical valves

• The caged ball valve (Starr-Edwards)
• The tilting disc (single leaflet) valve, and the bi leaflet valve
• Most mechanical valves will remain functional for 20-30 years
• Require Warfarinisation so avoided in those who cannot take Warfarin
• Heparin may be used instead in some cases for short term treatment
• Those in whom Warfarin required - AF

Complications

• Valve replacement provides marked symptomatic relief and improvement in survival.
• Endocarditis early < 60 days related to operation
• Endocarditis late > 60 days post operative typical endocarditis type organisms.
• Most prosthetic valve endocarditis requires valve removal and reoperation.
• Valve failure - mitral valves and younger patients more prone
• Embolisation - mitral and caged valves more so
• Valve Thrombosis - replace valve
• Anaemia and haemolysis
• Arrhythmias also occur.

Long term

• Endocarditis: all prosthetic valves require antibiotic prophylaxis against infective endocarditis during non-sterile procedures, e.g. dental treatment, lower gastrointestinal or urogenital procedures
• Anticoagulation for metal valves with Warfarin (NOACS not licensed)