Lower limb venous ultrasonographic examination for possible deep venous thrombosis among evacuees after the large-scale flood and landslide disaster in the Kii Peninsula

On August 25, 2011, Typhoon No.12 hit the village of Kitamata in Nosegawa, Nara Prefecture, Japan.Residents were forced to seek long-term shelter in evacuation facilities because of sediment runoff in the district.Authorities feared that these residents might have developed deep venous thrombosis (DVT).Thus, DVT screening was conducted among the residents in order to examine factors related to the occurrence of DVT among residents in landslide-affected areas.Methods: Among the residents, 33 were eligible for DVT screening.A portable ultrasonography equipment was used to explore for possible DVT in the soleal vein on both sides and measure its maximum diameter.Results: Of the 33 subjects, 3 (9.1%)had DVT, out of which 2 had fresh thrombi.On ultrasonography, all 3 patients (100%) had soleal vein extension of greater than 8mm and tested positive for DVT.However, no significant difference in soleal vein extension was found in comparison with the 11 patients (36.7%) who tested negative for DVT (p=0.0667). Conclusion:In the residents in this study who stayed in evacuation facilities over a long period after the landslide in their area, fresh DVT was confirmed.In addition, we identified soleal vein extension as a possible factor for the occurrence of DVT.