A system for delivering a medical instrument into a bodily cavity is provided, including an outer shaft having an aperture in a side wall thereof, wherein the aperture is provided at a distal portion of the outer shaft, an inner shaft positioned inside the outer shaft and having an inflatable balloon disposed at a distal portion thereof, and a needle member movably disposed in the outer shaft, wherein the needle member extends outwardly from the outer shaft through the aperture when the balloon is inflated.