Hello dear, thanks for your question on HCM.
I can understand your situation and problem.
Old age patients with congestive cardiac failure ( CCF ) and moderate
kidney failure tend to retain fluid due to ppor pumping of heart and poor excretion of fluids through kidneys.
So fluid tends to accumulate in the body.
These excess fluid retain in dependent part of the body like lower
limbs, abdomen and lungs.
Excess fluid in the lungs in known as
pulmonary edema and this can trouble patients with
cough and breathlessness.
So these excess fluid must be removed from the body.
So pigtail catheter is used for this. It is tiny, hollow rubber tube inserted in the chest (
stent like thing) for the removal of excess fluid.
So the treating doctor is mostly explained about pigtail catheter to your mother.