Absence of Anatomic Arteriovenous Shunts in Paget's Disease of Bone

Longitudinal study of calcium and bone metabolism in paraplegic patients

“…They are temporarily blocked at the arteriolar level. The presence in the leg of arteriovenous communications greater than 30 microns leads to the embolisation of the beads into the lungs (Rhodes et al, 1972). The activity profile along the long axis of the body enables us to determine the arteriovenous shunt of the leg (activity in the lungs divided by the total activity) and a distal vascularisation index obtained by dividing activity in the foot by that in the leg (R1/R2).…”

Regulation of blood flow in Paget's disease of bone.

“…However, several studies utilizing different techniques have failed to demonstrate arteriovenous fistulas (3)(4)(5). The present study may provide an alternative explanation for the elevated venous oxygen tension in Paget's disease.…”

“…Previous studies (4,5) flow to bone have not been reported. We suggest that there probably is a modest increase in blood flow to bone in Paget's disease (as indicated by previous studies), but that most of the increase in blood flow to extremities is the result of cutaneous vasodilatation.…”

“…It has been suggested that the increase in blood flow can be explained by arteriovenous fistulas in bone (3), since the oxygen tension in venous blood from "Pagetic" extremities is elevated (2). Although there is proliferation of vessels in bones with Paget's disease (2), neither histologic studies (3), arteriograms (4), nor injection of isotope-labeled microspheres (5) has demonstrated arteriovenous fistulas.…”

Complications of Paget’s Disease of Bone

“…Observations on this and other cases consistently showed an increased heart rate, cardiac output, and pulse pressure and re duced arteriovenous oxygen difference. A more recent isotopic study using intravascu lar injection of technetium-99m labelled hu man albumin microspheres [Rhodes et al, 1972] has likewise failed to produce any evi dence of anatomical vascular fistulae. It is concluded that the increased flow is due to a normally constituted but quantitatively in creased osseous vascular bed.…”