K. Langer et al., ULTRASTRUCTURAL-STUDY OF THE DERMAL MICROVASCULATURE IN PATIENTS UNDERGOING RETROGRADE INTRAVENOUS PRESSURE INFUSIONS, Dermatology, 192(2), 1996, pp. 103-109
Background: Retrograde intravenous pressure infusion (RIPI) of drugs,
e.g. antibiotics, under arterial occlusion (Bier's block) allows high
local tissue concentrations in the extremities. This technique is of p
articular value in the antibiotic treatment of infected diabetic foot
lesions. Objective: The aim of our study was to look for morphological
changes of the dermal microvasculature induced by RIPI. Methods: In 7
patients with infected diabetic foot lesions, punch biopsies were tak
en from the calf skin before and at the end of RIPI and studied by lig
ht and electron microscopy. Results: RIPI induced a dilatation of veno
us capillaries and postcapillary venules, loosening of contacts betwee
n endothelial cells (EC) with focal formation of small gaps in the ves
sel wall and a widening of the space between EC and pericytes. Lymphat
ic vessels were markedly dilated. In contrast, arterioles did not exhi
bit signs of morphological alteration. RIPI did not produce cellular d
amage of blood and lymphatic vessels. Conclusions: The morphological c
hanges of dermal vessels induced by RIPI are presumably due to a rapid
rise in venous pressure. Our morphological observations support resul
ts of previous hemodynamic and nuclear medical investigations, which s
howed that RIPI enhances the filtration and diffusion of molecules int
o the interstitium, leading to high local tissue concentrations. The v
enous capillaries and postcapillary venules are involved in this proce
ss in particular.