Ultrastructural study of the dermal microvasculature in patients undergoing retrograde intravenous pressure infusions.
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 particular 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 taken from the calf skin before and at the end of RIPI and studied by light and electron microscopy.


RESULTS
RIPI induced a dilatation of venous capillaries and postcapillary venules, loosening of contacts between endothelial cells (EC) with focal formation of small gaps in the vessel wall and a widening of the space between EC and pericytes. Lymphatic vessels were markedly dilated. In contrast, arterioles did not exhibit signs of morphological alteration. RIPI did not produce cellular damage of blood and lymphatic vessels.


CONCLUSIONS
The morphological changes of dermal vessels induced by RIPI are presumably due to a rapid rise in venous pressure. Our morphological observations support results of previous hemodynamic and nuclear medical investigations, which showed that RIPI enhances the filtration and diffusion of molecules into the interstitium, leading to high local tissue concentrations. The venous capillaries and postcapillary venules are involved in this process in particular.
Langer
K
K
Department of Dermatology, Wilhelminenspital, Vienna, Austria.
Seidler
C
C
Partsch
H
H
D000368:Aged; D000369:Aged, 80 and over; D000900:Anti-Bacterial Agents / Q000008:administration & dosage* / Q000627:therapeutic use; D001706:Biopsy; D002199:Capillary Permeability; D010478:Chemotherapy, Cancer, Regional Perfusion / Q000379:methods; D017719:Diabetic Foot / Q000188:drug therapy* / Q000473:pathology; D005260:Female; D006801:Humans; D007262:Infusions, Intravenous; D008297:Male; D008833:Microcirculation / Q000648:ultrastructure; D008854:Microscopy, Electron; D008875:Middle Aged; D011312:Pressure; D012867:Skin / Q000098:blood supply* / Q000473:pathology
D000900:Anti-Bacterial Agents