Functional and morphometric platelet abnormalities may be influenced by
splenectomy and thus contribute to postoperative thrombohaemorrhagic complications, especially in patients with
splenomegaly and/or platelet defects. We investigated platelet function, platelet secretion, and platelet morphometry before and one week after
splenectomy in seven patients with normal platelet production and normal spleen size (
Hodgkin's disease) and five patients with
splenomegaly and platelet abnormalities (4 with
myeloproliferative disorders and 1 with
chronic myelomonocytic leukemia). Severe postoperative thrombohaemorrhagic complications occurred only in patients with
myeloproliferative disorders, although platelet count and mean platelet volume increased in almost all patients after
splenectomy. Four patients with
myeloproliferative disorders had impaired platelet aggregation before
splenectomy that improved in only one patient after surgery. Platelet buoyant density in this patient group was decreased before
splenectomy and normalised thereafter. Concomitantly, intraplatelet concentrations of alpha-granular
proteins increased. Before
splenectomy, there was a positive correlation between platelet density and platelet volume in patients with
Hodgkin's disease (r = 0.59, p less than 0.001), but not in patients with
myeloproliferative disorders. There was no correlation between platelet density and platelet volume after
splenectomy in either patient group. In conclusion, morphometric platelet abnormalities were found in all patients after
splenectomy. In patients with myeloproliferative/myelodysplastic disorders, decreased platelet buoyant density normalised and intraplatelet concentrations of alpha-granule
proteins were elevated after
splenectomy. However, platelet function defects in this patient group were not corrected and may have been a major cause of thrombohaemorrhagic complications in the postoperative period.