Abstract: The present disclosure provides a catheter assembly including a catheter tube and an expandable unit attached to the catheter tube. The expandable unit is configurable in a collapsed configuration for facilitating delivery of the catheter assembly through a body lumen and a fully expanded configuration for contacting an interior wall of the body lumen to cover a perforation. The expandable unit defines a longitudinal channel extending from a proximal end to a distal end of the expandable unit when in the fully expanded configuration, permitting blood flow past the expandable unit. The disclosure further provides a method of treating a perforation by delivering a catheter assembly with an expandable unit to a perforation site, expanding the expandable unit to contact an interior wall of a body lumen to cover the perforation, and permitting blood flow past the expandable unit while in contact with the interior wall covering the perforation.