[Scintigraphic study (81mKr) of venous return activation using intravenous dihydroergotamine].

We study by 81mKr radionuclide phlebography 13 normal lower limbs and 22 limbs suffering from sequelae of deep vein thrombosis. We assess the spontaneous venous return and the effect of an intravenous injection of 0.5 mg dihydroergotamine (DHE), a powerful venoconstrictor agent. The phlebograms are analysed on a morphological basis. Dynamic data are also collected: the delay of arrival of the radioactivity at the groin and the regional radioactivity level at steady state (during the steady 81mKr perfusion). This segmental radioactivity is a positive marker of the venous stasis because it increases when the venous system dilates and when the flow goes down. It is normalized with regard to the radioactivity measured in the proximal segment (lower vena cava and proximal iliac vein). The influence of DHE on the delay of arrival of the radioactivity in the groin is variable: it is regularly and significantly shortened in the normal limbs (mean decrease of 6.5 s, table II). The segmental radioactivity is relatively low among these limbs (2.76 at the pelvic level, 9.68 at the high, tables IV and V). It drops significantly with DHE in all segments (tables IV and V: -44% in the pelvic veins, -57% in the great saphenous vein and -46% in the femoral tract). The post-thrombotic limbs showing spontaneously an abnormal deep network are characterized by a high radioactivity level (total in the high: 14.25, deep system 5.70 and 8.55 in the saphenous vein, table V). This segmental total radioactivity does not decrease significantly under the influence of DHE; even more it increases in the deep tract (+24%, table V).(ABSTRACT TRUNCATED AT 250 WORDS)