In article , Nick Maclaren
writes

Most of my tomato plants are strongly waisted, from the cold spell
a while back, and that seems to attract aphids. I have repotted
more deeply, but are they beyond hope? One was so badly waisted
that it broke, and is resprouting a little.

They may recover given time. If any of them have put out side-shoots,
those can be taken to propagate new plants which will be true to the
parent plant.
--
Alan & Joan Gould - North Lincs.