Arterio-venous shunt

A study on monkeys with 15- and 35-pm spheres. Acta Physiol Scand 95 60-65 Bergmatm H, Bock F, Bretmer H, Hbfer R (1973) Quantitative evaluation of arterio-venous shunts in brain tumours. In Medical radioisotope scintigraphy 1972, vol. II, International Atomic Energy Agency, Vierma, p 487... 

Brakkee, A.J. and Vendrik, A.J., Arterio-venous shunts in peripheral vascular systems, Pflugers Arch., 1970, 314, 170. 

In the course of investigation into the blood vessels of the ulcerated stomach it became evident that the circulation through the gastric vessels is modified as the result of the conditions of surgical operation. The mucous membrane of stomachs removed at operation is observed to be excluded from the active circulation in the stomach wall, [and] further studies indicate that this is brought about by the arterio-venous shunt, similar to that described by Trueta et al. (1947) in the kidney. 

While in HCC arterio-portal and arterio-venous shunting by direct tumor invasion is not uncommon, in metastases shunts are rare. Since the particle size of Tc MAA (30-90 pm) parallels that of the microsphere, the distribution of the microspheres can be predicted by an intra-arterial MAA scan. After transcatheter injection of 4-5 mCi (148-185 MBq) TcMAA into the estimated vascular territory of the tumor, intrahepatic distribution and potential pulmonary and also extrapulmonary shunting by aberrant, occult vessels can be assessed by a single photon emission CT (SPECT) gamma... 

An arterial-portal venous shunt can be detected with helical CT or dynamic contrast-enhanced MR imaging. The findings consist of early parenchymal enhancement associated with early filling of the portal vein (Hanafusa et al. 1995). Arterio-portal shunts are found in 25% of hemangiomas. They are not related to the lesion size but they are more frequently seen in hemangiomas with rapid enhancement (Fig. 8.3) (Kim et al. 2001b). 

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