“…IVC obstruction is prevalent in Asia, Nepal, South Africa, India, and China, whereas pure HVs obstruction predominates in Western countries. 31 This study showed that HVs obstruction was the most common pattern of venous obstruction (80%), combined HVs and IVC obstruction was similar to isolated IVC obstruction and were observed in 10%, while in another Egyptian study by Sakr et al, HVs obstruction, IVC obstruction, and combined HVs and IVC obstruction were found in 43%, 3%, and 21% of patients, respectively. 11 Darwish Murad reported isolated obstruction of HV, IVC, and both veins in 62%, 7%, and 31% of patients, respectively.…”