To identify patients at risk and assess management strategies, nine Datascope intraaortic balloon (IAB) ruptures in 8 patients were reviewed. This is a 2.4% incidence for this complication (382 insertions over 75 months). Time to initial rupture was 4.7 days, range 1.1 to 6.8 days. This was 1.3 days after the average intact device was removed. Women were three times more likely to sustain rupture than men (4 vs. 1.3%, P less than 0.05). Rupturing IABs were characterized by a greater magnitude of diastolic augmentation than intact IABs, 69.4 +/- 24.9 vs. 25.5 +/- 12.6 Torr (P = 0.01). A hypertensive treatment history was more prevalent in patients rupturing (83 vs. 41%) (P less than 0.05). Rupture was diagnosed by finding blood in the safety chamber in all patients. There was no gas embolization nor did any patient become infected. Ruptured devices showed abrasion wear in the most distal portion of the IAB, where the aorta is smallest. In vitro testing with CO2 showed no driving gas loss but withdrawal of the surrounding fluid into the IAB system. Ruptured IAB replacement in four patients was associated with three survivors. In four patients the device was not replaced and two patients survived. There were no complications as a consequence of IAB rupture (all values +/- SD).