  Aims. With an observing time span of more than 20 years, the CORALIE
radial-velocity survey is able to detect long-term trends in data corresponding
to companions with masses and separations accessible to direct imaging.
Combining exoplanet detection techniques such as radial velocities from the
CORALIE survey, astrometric accelerations from Hipparcos and Gaia eDR3, and
relative astrometry from direct imaging, removes the degeneracy of unknown
orbital parameters. This allows precise model-independent masses of detected
companions to be derived, which provides a powerful tool to test models of
stellar and substellar mass-luminosity relations. Methods. Long-term precise
Doppler measurements with the CORALIE spectrograph reveal radial-velocity
signatures of companions on long-period orbits. The long baseline of
radial-velocity data allows the detectability of such companion candidates to
be assessed with direct imaging. We combine long-period radial-velocity data
with absolute astrometry from Hipparcos and Gaia eDR3 and relative astrometry
derived from new direct imaging detections with VLT/SPHERE to fit orbital
parameters and derive precise dynamical masses of these companions. Results. In
this paper we report the discovery of new companions orbiting HD~142234,
HD~143616, and HIP~22059, as well as the first direct detection of HD~92987~B,
and update the dynamical masses of two previously directly imaged companions;
HD~157338~B and HD~195010~B. The companions span a period range of 32 to 279
years and are all very low mass stellar companions, ranging from 218 to
487~$M_{\rm{Jup}}$. We compare the derived dynamical masses to mass-luminosity
relations of very low mass stars (<0.5~$M_{\odot}$), and discuss the importance
of using precursor radial-velocity and astrometric information to inform the
future of high-contrast imaging of exoplanets and brown dwarfs
