13 Endomyocardial Biopsy
Indications
Indications for endomyocardial biopsy are discussed in more detail in the chapters dealing with specific diseases. Clinical indications include:
Follow-up after cardiac transplantation
Differentiation of restrictive versus constrictive cardiomyopathy
Suspected myocarditis (infectious or noninfectious)
Systemic diseases with cardiac involvement (sarcoidosis, amyloidosis, hemochromatosis)
Anthracycline-induced cardiomyopathy
Whether or not an endomyocardial biopsy should be performed depends crucially on the expected impact the findings will have on patient management. While biopsy results clearly affect treatment after cardiac transplantation, in other clinical settings the results of a biopsy may be without consequences.
Prerequisite for a proper interpretation of the biopsies is the prior determination of the following processing and examination requirements, which depend on the clinical questions:
Histology
Electron microscopy
Immunohistochemistry
Molecular biology (in situ hybridization, virus detection with PCR)
For example, histopathological and immunohistochemical processing and specific staining of the endomyocardial biopsies is sufficient to detect a specific cardiac disease (amyloidosis) or to diagnose and determine the extent of inflammation and can be performed by most pathologists. In contrast, the molecular biological diagnosis of myocarditis with in situ hybridization and virus detection is possible only in specialized centers. Prior consultation with the institute to harmonize clinical questions and examinations is recommended.
Site of Biopsy
Depending on the clinical question, the following structures can be biopsied:
Interventricular septum from the right ventricle via a transvenous access
Lateral or posterolateral wall of the left ventricle transarterially and retrogradely via the aortic valve
Personal view
If inflammatory changes have been detected in the lateral wall segments of the left ventricle by cardiac MRI, we prefer to take left ventricular biopsies specifically from the pathological areas, whereas for generalized processes we take biopsies from the interventricular septum transvenously.
Material
8F sheath
Guidewire: 0.035 in., 135 cm, J-tip
Endomyocardial biopsy forceps (bioptome): various manufacturers (Fig. 13.1). Length for femoral access: 104 cm
Guiding catheter: long sheath (7F or 8F; length 98 cm) with hemostatic valve and straight or curved tip (alternatively, a 8F multipurpose PTCA guiding catheter or 8F RCA guiding catheter in the left ventricle for lateral biopsy) can be used—however, there is a risk of air embolization (no hemostatic valve))
Biopsy container: Sample processing as arranged with the consulting pathologist: