Gelatin-impregnated nonporous sealed grafts were introduced in the inflow and outflow conduits for use with the HeartMate II (HMII) to eliminate preclotting procedures and to reduce operative bleeding. We compared results of 67 patients who received first-time left ventricular assist devices (LVADs) with sealed inflow and outflow grafts (S-graft group) with a preceding 65 patients who received an LVAD with nonsealed grafts (NS-graft group). Overall, the amount of blood product transfusions was less in the S-graft group than that in the NS-graft group (red blood cells, 4.9 ± 4.5 vs. 8.0 ± 9.4 units, p = 0.022; fresh-frozen plasma, 5.0 ± 3.0 vs. 8.7 ± 9.3 units, p = 0.004; platelets, 2.9 ± 1.1 vs. 4.5 ± 3.5 units, p = 0.001; and cryoprecipitate, 1.2 ± 0.9 vs. 2.01 ± 1.9 units, p = 0.002). Within a follow-up period of 6 months, no device-related infections or strokes occurred in the S-group, but the NS-group had one (1.5%) driveline infections and four (6%) strokes. The 30 days survival rate was not significantly different between groups (p = 0.053), but favored the S-group (97%) over the NS-group (88%). Use of a HMII with a sealed graft on the inflow and outflow conduits is associated with less postoperative bleeding and may have helped to decrease the frequency of postoperative adverse events.