A deflation indicator system for visually indicating an inflation status of a balloon-type or other inflatable internal bolster of a medical device is disclosed. The indicator system enables an observer to ascertain from an external vantage point whether the internal bolster of the indwelling device is inflated. In one embodiment, the medical device comprises an elongate body defining a lumen, and an inflatable internal bolster for securing a portion of the medical device within the patient. A deflation indicator is also disclosed, including a flexible membrane in fluid communication with the internal bolster. The membrane is included in an external portion of the medical device. The membrane assumes a first concavely-shaped position when the internal bolster is deflated. Correspondingly, the membrane assumes a second convexly-shaped position when the internal bolster is inflated. The positions of the membrane are externally observable to indicate the inflation status of the internal bolster.