Figure 3. Venous flows of the IVC and left renal vein in early postoperative period after en bloc resection. (A-E) The IVC and LRV were resected for en bloc resection of PPT and actual findings of dynamic computed tomography at 13 days after surgery. Venous flow into the IVC was kept via developed collaterals in the pelvic space, gluteus maximus muscle, mesorectum and mesocolon, retroperitoneal space around the iliopsoas muscle and Gerota fascia (yellow arrows). These developed collaterals from the IVC flowed into the inferior and superior mesenteric veins and SV (yellow arrows). Venous flow of the LRV was kept mainly via splenorenal shunt (blue arrows), and other developed collaterals from the left renal vein flowed into the superior mesenteric vein and IVC (yellow arrows). Congestion or flow disorder was not observed in the left kidney. Hence, venous flow from the IVC and LRV were well preserved by developed collaterals and splenorenal shunt in the early postoperative period (Case 1). (F) The IVC was partially resected for en bloc resection of PPT, and actual findings of dynamic computed tomography at 14 days after surgery are shown. The patency of partially resected IVC was well kept from early postoperative period (Case 2). IVC – inferior vena cava; LRV – left renal vein; PPT – paraaortic and/or pelvic tumor; SAG – synthetic arterial graft; SV – splenic vein.