Effect of liver transplantation on spleen size, collateral veins, and platelet counts.

Background: The aim of this study was to evaluate the effect of liver transplantation on the spleen size, spontaneous splenorenal shunt (SRS) function, and platelet counts in patients with hypersplenism.
Methods: Between December 2001 and February 2007, 462 adult patients underwent orthotopic liver transplantations (OLTX) at our institution. Of these patients, CT or MRI information was reviewed retrospectively in 55 patients. Volume measurements of the spleen and liver, spleen/liver volume ratio (S/L ratio), presence and size of SRS, and platelet counts were evaluated before and after OLTX.
Results: Mean spleen volume decreased from 827 +/- 463 ml to 662 +/- 376 ml after OLTX (p < 0.01). Five (11%) patients returned to normal-range spleen size after OLTX. SRS was observed in 19 patients before OLTX (35%). The diameter of SRS also significantly decreased from 1.0 +/- 0.5 cm before OLTX to 0.7 +/- 0.5 cm after OLTX (p < 0.05). SRS disappeared in 16% of patients (3/19). S/L ratio significantly decreased from 0.65 +/- 0.33 to 0.38 +/- 0.17 (p < 0.01) after OLTX. Platelet counts significantly increased after OLTX (p < 0.01). Improvement of the platelet count in the group with postoperative S/L ratio >0.35 was not as good as that in the group with S/L ratio <0.35 (p < 0.01).
Conclusions: Spleen size and SRS size became significantly smaller after OLTX. However, patients with postoperative S/L ratio >0.35 tend to have lower platelet counts after OLTX.