Guidewire-assisted successful closure of mis-punctured transverse colon during endoscopic ultrasound-guided cyst drainage.

Endoscopic ultrasound-guided cyst drainage (EUS-CD) was performed for walled-off pancreatic necrosis. Computed tomography performed the next day showed that the tip of the external drainage tube was located in the transverse colon, confirming an accidental EUS-CD-associated complication of mis-puncture. A colonoscopy was performed to confirm the puncture site, which was identified as a defect measuring 2 mm in diameter. The external drainage tube was removed immediately via a guidewire. We intentionally retained the guidewire as a landmark for the puncture site in the colon. The defect was approximated using an endoclip under full vision, with the guidewire covered with surrounding mucosa. After removing the guidewire smoothly, complete closure was achieved with additional endoclips. Four days later, EUS-CD was successfully repeated, resulting in the resolution of the walled-off pancreatic necrosis. This is the first known case in which an accidental puncture of the transverse colon occurred during EUS-CD for walled-off pancreatic necrosis, and guidewire-guided clip closure of the colon contributed to troubleshooting.