A working cannula is advanced through the urethra into the bladder. Gas is infused through the cannula into the bladder, pressurizing the bladder. A fenestrating shunt catheter is then advanced through the urethra into the bladder and against the wall of the bladder, fenestrating it. A distal segment of the shunt catheter is then advanced through the wall into the peritoneal space, while a more proximal segment of the shunt catheter remains in the bladder. Shunt holes are formed in both the distal segment and more proximal segment so that gas from the pressurized bladder flows through the shunt holes into the peritoneal space, insufflating the peritoneal space.
