Yoshiki Kuwatsuru

Background The extent of renal angiomyolipoma (AML) volume reduction after renal transcatheter arterial embolization (TAE) varies between patients, with no predictive measure available. Purpose To determine whether the serum lactate dehydrogenase (LDH) concentration shortly after TAE correlates with the extent of tumor shrinkage. Material and Methods In a cohort of 36 patients undergoing prophylactic renal TAE for unruptured renal AML, we retrospectively acquired data from patient medical records, including serum LDH before and within 7 days after TAE and the tumor volume before and 12–36 months after TAE. The relationship between the serum level of LDH and reduction in tumor volume was evaluated using Spearman correlation analysis. Results The median LDH concentration was significantly higher after TAE than before (909.0 U/L vs. 186.5 U/L). This early post-TAE serum LDH level and LDH index (post-TAE LDH / pre-TAE LDH) correlated significantly and positively with the absolute decrease in tumor volume (both P < 0.0001). We observed no significant correlation between the relative tumor volume reduction and serum LDH level or LDH index. Conclusion Serum LDH elevation occurs shortly after TAE and correlates with the extent of absolute decrease in AML volume at 12–36 months after TAE. Further large-scale studies are warranted to confirm the predictive role of post-TAE serum LDH level and LDH index in tumor shrinkage in patients with unruptured renal AML.

Objective To examine the effect of supplementary microcoil embolization on the long-term progression of angiomyolipomas embolized using gelatin sponge particles (GSPs). Methods This retrospective study included 29 unruptured angiomyolipomas in 25 patients, treated by complete embolization and radiological follow-up for ≥3 years. Embolization was performed using GSPs and supplementary microcoils. Supplementary microcoil embolization affecting >90% of the tumor vasculature was defined as microcoil embolization. Tumor volumes pre- and post-embolization were measured by computed tomography or magnetic resonance imaging. Results Eleven tumors received supplementary microcoil embolization and 18 tumors did not. Relative tumor reduction at >3 years post-embolization was significantly greater in tumors with supplementary microcoil embolization compared with tumors without microcoil embolization (81% ± 8% vs. 55% ± 29%). Fourteen tumors tended to show volume regrowth and the volumes of the remaining 15 tumors continued to decline. Tumors without supplementary microcoil embolization were more likely to show volume regrowth during follow-up than tumors with supplementary microcoil embolization (78% vs. 0%, respectively). Conclusions When using a combination of GSPs and microcoils, supplementary microcoil embolization should be carried out to ensure maximum long-term reduction in tumor volume in patients with angiomyolipomas.