  Our Keck/NIRC2 imaging survey searches for stellar companions around 144
systems with radial velocity (RV) detected giant planets to determine whether
stellar binaries influence the planets' orbital parameters. This survey, the
largest of its kind to date, finds eight confirmed binary systems and three
confirmed triple systems. These include three new multi-stellar systems (HD
30856, HD 86081, and HD 207832) and three multi-stellar systems with newly
confirmed common proper motion (HD 43691, HD 116029, and HD 164509). We combine
these systems with seven RV planet-hosting multi-stellar systems from the
literature in order to test for differences in the properties of planets with
semimajor axes ranging between 0.1-5 au in single vs multi-stellar systems. We
find no evidence that the presence or absence of stellar companions alters the
distribution of planet properties in these systems. Although the observed
stellar companions might influence the orbits of more distant planetary
companions in these systems, our RV observations currently provide only weak
constraints on the masses and orbital properties of planets beyond 5 au. In
order to aid future efforts to characterize long period RV companions in these
systems, we publish our contrast curves for all 144 targets. Using four years
of astrometry for six hierarchical triple star systems hosting giant planets,
we fit the orbits of the stellar companions in order to characterize the
orbital architecture in these systems. We find that the orbital plane of the
secondary and tertiary companions are inconsistent with an edge-on orbit in
four out of six cases.
