Introduction: Although spleen volume (SV) has been thought to decrease after living donor liver transplantation (LDLT), there are a few cases in which SV gradually increases and the expansion can lead to life-threatening complications. However, it is unclear which patients have such a risk. This study was conducted to investigate factors associated with SV expansion after LDLT.
Materials: Patients with liver cirrhosis due to biliary atresia (BA), who had LDLT between March 2008 and July 2017 in our institute, were included in this study. CT scan was performed approximately 3 months (3±1 months) after LDLT. Those patients, who had splenectomy with LDLT simultaneously and who died within 3 months after LDLT, were excluded.
Methods: Age, sex, standard liver volume (SLV) for each patient, transplanted graft volume (GV), SV before and approximately 3 months after LDLT were evaluated. The major, minor and longitudinal diameter of spleen were measured on the cross-sectional surface with splenic hilar. SV was calculated by multiplying these values and evaluated as SV/body surface area (BSA) to compare patients with variable ages. Patients were divided into SV/BSA ≥1,000ml and <1,000ml. The volume reduction rate was calculated using the formula of [((Preoperative SV) – (Postoperative SV))/Preoperative SV]×100. Using this rate, patients were divided into two groups; SV reduction and SV expansion. Factors which could affect postoperative SV were evaluated using the univariable regression analysis. The impact of postoperative Plt on SV expansion was measured with the logistic regression analysis.
Results: 33 patients (11 males and 22 females) were enrolled.The mean age of these patients was 3.7±5.4 years old. The mean GV/SLV and GV/body weight were 76.8±22.1% and 2.47±0.94%, respectively. The mean SV/BSA before and after LDLT, and SV reduction rate were 780.8±287.0ml/m², 569.2±254.7ml/m² and 23.4±31.0%, respectively. There were five patients whose SV increased postoperatively. The mean age and postoperative Plt of patients with preoperative SV/BSA ≥1,000ml was significantly older and lower than those with <1,000ml (p=0.0016 and 0.039, respectively). All laboratory values except Plt were significantly improved after LDLT, and there was a significant difference in postoperative Plt between SV reduction and SV expansion groups (19.0±7.8 and 10.7±5.6 (×10⁴/μl), respectively (p=0.031)).In the univariable regression analysis, postoperative Plt had a significant effect on SV reduction rate (regression coefficient, 1.52 (CI 0.23-2.82; p=0.022)). In the logistic regression analysis, there was a significant impact of postoperative Plt on SV expansion after LDLT (OR 0.808 (CI 0.661-0.988; p=0.038)).
Discussion/Conclusion: Remaining low Plt after LDLT could indicate the poor SV reduction and may predict SV expansion. Adolescent patients with preoperative SV/BSA ≥1,000ml should undergo splenectomy with LDLT.