WASHINGTON — Cannula obstruction and inflow valve regurgitation of left ventricular assist devices may contribute to recurrent heart failure in long-term users of the devices, according to findings from a small review study.
Among 61 patients who have been implanted with a left ventricular assist device (LVAD) at Sharp Memorial Hospital, San Diego, since 1995, 6 have developed recurrent heart failure. On catheterization of the heart, LVAD, and cannulae, 3 of the 6 patients had inflow cannula valve regurgitation seen on LVAD angiography.
Those 3 patients had received their LVADs between 309 and 696 days prior to the diagnosis of regurgitation.
All 3 of the patients recovered following replacement of the LVAD cannula, David A. Miller reported during a moderated poster session at the annual conference of the American Society for Artificial Internal Organs.
In three other patients, a two-catheter approach helped to identify obstruction of the inflow cannula as a result of a pressure gradient between the LVAD and the left ventricle that was identified during the filling phase. Their duration of LVAD use ranged from 40 to 81 days before they were diagnosed with obstruction of the inflow cannula.
Although the three patients underwent surgical repositioning of the cannula, only one recovered from the surgery, said Mr. Miller, who was a research associate at Sharp Memorial. He is now at the University of California at Irvine.
A control group of four LVAD patients without symptoms of heart failure who were undergoing catheterization for other reasons did not show any dysfunction of the inflow cannula.