You can try BoxWhiskerChart[{{1, 2, 3}, {2, 3, 4}}, {{"MedianMarker", 0,
Opacity[0]}, {"Whiskers", Opacity[0]}, {"Fences", 0, Opacity[0]}},
BarOrigin -> Left]`
Opacity[0]}, {"Whiskers", Opacity[0]}, {"Fences", 0, Opacity[0]}},
BarOrigin -> Left]`