Percutaneous Transvenous Coil Embolization (PTCE) of Congenital Intrahepatic Portosystemic Shunts
Portosystemic shunts (PSSs) are anomalous vascular communications between the portal venous and systemic circulations that result in a clinical syndrome with various neurological, biochemical, and hematological consequences. Single, extrahepatic PSSs are amenable to relatively uncomplicated surgical attenuation with a reported success rate of 90-95%. Alternatively, single intrahepatic PSSs are consistently more challenging to treat surgically. Numerous techniques have been described for intrahepatic PSS attenuation, ranging from careful liver dissection around the shunting vessel to more technically demanding and complicated procedures involving temporary vascular hepatic inflow occlusion for intravascular repair. A review of some of the major veterinary reports on canine intrahepatic PSSs reveals mortality rates following surgical treatment as high as 60% and post-operative complications rates of 77%.4-12 Interestingly, the majority of mortalities occurred peri-operatively. The goal of treating intrahepatic PSSs with interventional radiology is to reduce the unacceptably high, peri-operative morbidity and mortality rates associated with traditional open surgical techniques and hopefully improve the outcome for these cases. Intrahepatic portosystemic shunt PTCE has been reported to have reduced peri-operative morbidity rates with similar long-term success as that reported for many open surgical procedures.13 (FIGURE 3)
Figure 3. Percutaneous transvenous coil embolization of right divisional intrahepatic portosystemic shunt. (A) DSA of portal vein (PV), shunt (PSS), and caudal vena cava (CVC) through transjugular catheter. (B) Simultaneous DSA of CVC and PV through two separate transjugular catheters demonstrating location of shunt entrance into CVC. (C) Radiograph following caval stent deployment across shunt orifice. (D) DSA of PSS via catheter passed through stent interstices demonstrating appropriate stent position across. shunt entrance. (E) DSA of PSS following placement of multiple thrombogenic coils (white arrows) within PSS. (F) Final radiograph of caval stent and coils prior to catheter removal.
Foreign Body Retrieval
Image-guided removal of vascular foreign bodies (catheter-fragments, etc.) can be performed relatively rapidly and minimally-invasively using IR techniques in order to avoid more aggressive surgical techniques or the risk associated with leaving these foreign materials in vivo. Similar to the human experience, the increased use of vascular access and implantable devices in veterinary patients will likely result in an increased frequency of dislodged or migrated vascular foreign bodies encountered and diagnosed by veterinarians.14