MYOCARDIAL BIOPSY

Trans-Septal Myocardial Biopsy in Hypertrophic Cardiomyopathy Using the Liwen Procedure: An Introduction of a Novel Technique

Objective

The purpose of this study was to evaluate the feasibility and safety of myocardial biopsy using a new approach, the Liwen procedure.

Background

Myocardial biopsy is essential when other methods could not differentiate other etiologies from hypertrophic obstructive cardiomyopathy (HOCM). Our previous work using intramyocardial radiofrequency ablation for hypertrophic obstructive cardiomyopathy (Liwen procedure) may provide another approach to obtain the myocardial samples.

Method

Seventeen patients with HOCM were enrolled for biopsies through percutaneously accessed intramyocardial septum and evaluated possible complications.

Results

We obtained 31 specimens from 17 patients with a success rate of sample acquisition 100.0%. The number of myocardial samples taken per patient was 1.8 ± 0.8, and the average length of all samples was 16.7 ± 5.6 mm which could be used for pathological diagnosis. The complications included pericardial effusion with and without tamponade in one patient (5.9%), and no incidence of nonsustained and sustained ventricular tachycardia, conduction abnormity, perforation, stroke, and pneumothorax. The inhospital and 30-day mortality was 0%.

Conclusion

This study has shown that myocardial biopsy of the Liwen procedure is relatively safe and technically feasible with adequate tissue sampling, which may help pathological diagnosis and further research of HOCM of diverse etiologies. This trial is registered with NCT04355260.

Endomyocardial biopsy: a review of the literature

A review of the literature relating to endomyocardial biopsy (EMB) is presented. This is considered important at this time since EMB is being utilized with increasing frequency, particularly for the diagnosis of myocarditis. The development of the technique is briefly outlined. Emphasis is placed on the clinical application of EMB in the various primary cardiomyopathies (dilated, hypertrophic, restrictive, and obliterative), the infiltrative secondary cardiomyopathies (amyloidosis, sarcoidosis, hemochromatosis), myocarditis, as well as such conditions as adriamycin cardiotoxicity, cardiac transplant rejection, and Kawasaki disease. More controversial application of EMB in primary mitral valve prolapse (Barlow's syndrome), idiopathic ventricular arrhythmias, and the elucidation of the enigmatic finding of angina with angiographically normal coronary arteries is detailed. Experience with immunological and biochemical investigation of biopsy material, as well as with virus isolation and drug assays in the myocardium, is alluded to. Complications encountered with this procedure are also discussed, and its future role is contemplated.

Effectiveness and hazard of endomyocardial biopsy in dogs: comparison of two methods

Two different methods of endomyocardial biopsy were evaluated. Compared to the Konno bioptome, a technique using a biopsy forceps originally designed for fiberoptic bronchoscopy and bronchial biopsy, passed through a No. 9 Fr. end-hole catheter, was easier to perform. The biopsy device is smaller than the Konno bioptome, has sharper teeth, and is easier to clean. The two techniques did not differ in arrhythmogenicity, hemorrhagic changes in the myocardium, or distortion of the specimens. Ventricular tachycardia as defined by three beats in a row was observed in 34 per cent. Epicardial hemorrhage was seen in nine of 14 animals, and the specimen distortion rate was 43 per cent. In one animal, perforation of the right ventricle and hemopericardium occurred.