Size and geometry of the interendothelial slit and resulting RBC deformation. (Ai) Transmission electron micrograph (original magnification ×2000) of RBCs squeezing through an interendothelial slit (ie, between 2 adjacent endothelial cells [EC], from the cord [Co] to the sinus lumen [SL], white star showing the anterior pole of the RBCs). (Aii) Width (red double-headed arrow) and length (black double-headed arrow) of the interendothelial slit at high original magnification (×5000) as measured on 11 pictures. (B) Dumbbell-shaped RBCs as observed on a transmission electron micrograph (Bi, white star showing the anterior pole of the RBCs), or as expected to occur as a RBCs squeeze between microbeads (Bii), or as observed under the contrast-phase microscope after formaldehyde fixation of RBCs engaged within the microbead layer (Biii). (Biv) Schematic flow routes and shape deformation of RBCs squeezing through a narrow and short interbead space interspersed in wider spaces (left route), or only through wide spaces (right route). (Bv) Schematic longitudinal elongation of RBCs flowing though a narrow and long channel in a polycarbonate sieve. (C) Morphologic aspect of RBCs on Giemsa-stained smears showing either a normal discoid aspect downstream from the microbead layer (Ci), or dacryocytes (vertical arrows), schizocytes (horizontal arrows), poikilocytes (stars), and anisocytosis downstream from a narrow, 2-μm-wide, 24-μm-long channels (Cii).