Transdiaphragmatic Approach to Attenuate Porto‐Azygos Shunts Inserting in the Thorax

Abstract

If thoracic attenuation of a porto-azygos shunt is considered, a transdiaphragmatic approach exposes the insertion site for shunt attenuation. This approach is straightforward, without unnecessary abdominal organ manipulation, and since attenuates at the insertion, avoids missing additional contributing branches.

Implications of shunt morphology for the surgical management of extrahepatic portosystemic shunts

“…The authors acknowledge that certain of the more uncommon shunts types were not encountered in this study. For some of these, such as the previously described right gastro‐azygos EHPSS, the site of communication with the systemic vein is recognised to be in the same region as one or more of the common shunt types encountered in this current study . Typically, for the right gastro‐azygos EHPSS, this communication would be with the azygos vein in the region of the oesophageal/aortic hiatus in a similar manner to that seen with the more common left gastrophrenic and the left gastro‐azygos EHPSS .…”

“…If the stomach is subsequently retracted cranially, the portal vein and its tributaries may be identified running within the dorsal leaf of the omentum. Abnormal shunting vessels may be identified and, if applicable, traced to their communication site with the prehepatic CVC . In the current study, this approach to the prehepatic CVC and the epiploic foramen was not used or required; all shunts entering the prehepatic CVC at the level of the epiploic foramen were located and attenuated using the mesoduodenum as a mesenteric ‘dam’, as described.…”

“…Regardless of the technique used, it is recommended that the site of closure of the shunt be at its connection with the systemic circulation . Should the shunt be attenuated too far from this site of communication, there remains the possibility that portal tributary vessels exist distal to the point of attenuation, leading to the persistence of both portal shunting of blood and clinical signs of hepatic encephalopathy …”

Transdiaphragmatic pericardiectomy in dogs

“…The transdiaphragmatic approach was first described in dogs in 1986 for epicardial pacemaker implantation (Fingeroth and Birchard 1986) for which it is still considered to be the preferred method (Visser and others 2013, Tillson 2015). Presently, a transdiaphragmatic incision is used to access the posthepatic part of the caudal vena cava, the caudal part of the intrathoracic aorta, the caudal part of the thoracic duct (Hunt 2012, Tillson 2015), the caudal portion of the oesophagus (Hunt 2012) and the insertion of porto-azygos shunts (Or and others 2016). The location of the incision in the diaphragm is related to the area of interest in the thorax; central (ventral and dorsal), right, as well as left incisions have been reported (Hunt 2012, Tillson 2015, Or and others 2016).…”

“…Presently, a transdiaphragmatic incision is used to access the posthepatic part of the caudal vena cava, the caudal part of the intrathoracic aorta, the caudal part of the thoracic duct (Hunt 2012, Tillson 2015), the caudal portion of the oesophagus (Hunt 2012) and the insertion of porto-azygos shunts (Or and others 2016). The location of the incision in the diaphragm is related to the area of interest in the thorax; central (ventral and dorsal), right, as well as left incisions have been reported (Hunt 2012, Tillson 2015, Or and others 2016). The current study documented that the approach with an incision slightly to the left is suitable for subtotal pericardiectomy in dogs.…”