Diagnostic Conundrum - ? Budd Chiari

A 24 year old lady presented to our centre with c/o vague abdominal pain, acid eructations and poor apetite. She was seen by doctors in Madanapalle and treated with PPIs as well as Antacids.
A G3 P3, 1st child born through LSCS.
O/E: General Exam - was normal.
Abdomen: Tortuous dilated superficial abdominal veins, with hepatic flow. (The pictures below show you the location and size of the veins)

There was a 2 cm soft hepatomegaly, no splenomegaly or free fluid.

USG: Mild to moderate hepatomegaly, abdominal varices, prominent mid hepatic vein with absence of right and left hepatic veins.

Whats the Diagnosis and how will you proceed? Please help????