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Intrahepatic Vascular Anatomy in Rats and Mice--Variations and Surgical Implications.

Sänger C, Schenk A, Schwen LO, Wang L, Gremse F, Zafarnia S, Kiessling F, Xie C, Wei W, Richter B, Dirsch O, Dahmen U - PLoS ONE (2015)

Bottom Line: Surgically relevant variations were primarily observed in portal venous supply.We showed that lobar borders of the liver do not always match vascular territorial borders.These findings are of importance for the design of new surgical procedures and for understanding eventual complications following hepatic surgery.

View Article: PubMed Central - PubMed

Affiliation: Universitätsklinikum Jena, Klinik für Allgemein-, Viszeral- und Gefäßchirurgie, Experimentelle Transplantationschirurgie, Jena, Germany.

ABSTRACT

Introduction: The intra-hepatic vascular anatomy in rodents, its variations and corresponding supplying and draining territories in respect to the lobar structure of the liver have not been described. We performed a detailed anatomical imaging study in rats and mice to allow for further refinement of experimental surgical approaches.

Methods: LEWIS-Rats and C57Bl/6N-Mice were subjected to ex-vivo imaging using μCT. The image data were used for semi-automated segmentation to extract the hepatic vascular tree as prerequisite for 3D visualization. The underlying vascular anatomy was reconstructed, analysed and used for determining hepatic vascular territories.

Results: The four major liver lobes have their own lobar portal supply and hepatic drainage territories. In contrast, the paracaval liver is supplied by various small branches from right and caudate portal veins and drains directly into the vena cava. Variations in hepatic vascular anatomy were observed in terms of branching pattern and distance of branches to each other. The portal vein anatomy is more variable than the hepatic vein anatomy. Surgically relevant variations were primarily observed in portal venous supply.

Conclusions: For the first time the key variations of intrahepatic vascular anatomy in mice and rats and their surgical implications were described. We showed that lobar borders of the liver do not always match vascular territorial borders. These findings are of importance for the design of new surgical procedures and for understanding eventual complications following hepatic surgery.

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Hepatic vein variations of the right lobe and surgical implications in rats. 3D visualization.A) Visualization of hepatic vein vascular tree. One single stem of left median HV was observed in 7/15 cases. B) Visualization of hepato venous territories. Transection of median lobe along umbilical fissure with low risk of outflow obstruction of left median lobe possible. C) Visualization of hepatic vein vascular tree. Two left median HV stems were observed in 8/15 cases. D) Visualization of hepatovenous territories. Transection of median lobe along umbilical fissure with high risk of outflow obstruction of left median lobe. Red line is umbilical transection line. Encircled is the median lobe. HV-Hepatic vein, ICL-inferior caudate lobe, LML-left median lobe, LLL-left lateral lobe, ML-Median lobe, RIL-right inferior lobe, RML-right median lobe, RSL-right superior lobe, SCL-superior caudate lobe.
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pone.0141798.g004: Hepatic vein variations of the right lobe and surgical implications in rats. 3D visualization.A) Visualization of hepatic vein vascular tree. One single stem of left median HV was observed in 7/15 cases. B) Visualization of hepato venous territories. Transection of median lobe along umbilical fissure with low risk of outflow obstruction of left median lobe possible. C) Visualization of hepatic vein vascular tree. Two left median HV stems were observed in 8/15 cases. D) Visualization of hepatovenous territories. Transection of median lobe along umbilical fissure with high risk of outflow obstruction of left median lobe. Red line is umbilical transection line. Encircled is the median lobe. HV-Hepatic vein, ICL-inferior caudate lobe, LML-left median lobe, LLL-left lateral lobe, ML-Median lobe, RIL-right inferior lobe, RML-right median lobe, RSL-right superior lobe, SCL-superior caudate lobe.

Mentions: The median lobe was drained by three hepatic veins in all cases (Fig 1B). The territory of the right median hepatic vein was always well defined. The middle median hepatic vein is also anatomically well-defined and drains the middle median sector. The left median hepatic vein showed a higher degree of variability. In 7 of 15 cases we observed a single left median hepatic vein forming a confluence with the branches of left lateral hepatic vein (Fig 4A and 4B). In 8 of 15 cases we observed two branches, one draining into middle median hepatic vein and the other one formed the confluence with left lateral hepatic vein. This is potentially of surgical importance when creating a surgical transection model using the median lobe as applied for revascularisation studies after ALPPS. Transection along the umbilical fissure leaves the right and middle median hepatic vein to the large right “hemi”-liver, whereas the left median hepatic vein ensures the drainage of the small left “hemi”-liver. In case of one left median hepatic vein, the risk of outflow obstruction after transection is low (Fig 4A and 4B). In contrast and in case of two left median hepatic veins the risk for outflow obstruction is rather high (Fig 4C and 4D).


Intrahepatic Vascular Anatomy in Rats and Mice--Variations and Surgical Implications.

Sänger C, Schenk A, Schwen LO, Wang L, Gremse F, Zafarnia S, Kiessling F, Xie C, Wei W, Richter B, Dirsch O, Dahmen U - PLoS ONE (2015)

Hepatic vein variations of the right lobe and surgical implications in rats. 3D visualization.A) Visualization of hepatic vein vascular tree. One single stem of left median HV was observed in 7/15 cases. B) Visualization of hepato venous territories. Transection of median lobe along umbilical fissure with low risk of outflow obstruction of left median lobe possible. C) Visualization of hepatic vein vascular tree. Two left median HV stems were observed in 8/15 cases. D) Visualization of hepatovenous territories. Transection of median lobe along umbilical fissure with high risk of outflow obstruction of left median lobe. Red line is umbilical transection line. Encircled is the median lobe. HV-Hepatic vein, ICL-inferior caudate lobe, LML-left median lobe, LLL-left lateral lobe, ML-Median lobe, RIL-right inferior lobe, RML-right median lobe, RSL-right superior lobe, SCL-superior caudate lobe.
© Copyright Policy
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4664386&req=5

pone.0141798.g004: Hepatic vein variations of the right lobe and surgical implications in rats. 3D visualization.A) Visualization of hepatic vein vascular tree. One single stem of left median HV was observed in 7/15 cases. B) Visualization of hepato venous territories. Transection of median lobe along umbilical fissure with low risk of outflow obstruction of left median lobe possible. C) Visualization of hepatic vein vascular tree. Two left median HV stems were observed in 8/15 cases. D) Visualization of hepatovenous territories. Transection of median lobe along umbilical fissure with high risk of outflow obstruction of left median lobe. Red line is umbilical transection line. Encircled is the median lobe. HV-Hepatic vein, ICL-inferior caudate lobe, LML-left median lobe, LLL-left lateral lobe, ML-Median lobe, RIL-right inferior lobe, RML-right median lobe, RSL-right superior lobe, SCL-superior caudate lobe.
Mentions: The median lobe was drained by three hepatic veins in all cases (Fig 1B). The territory of the right median hepatic vein was always well defined. The middle median hepatic vein is also anatomically well-defined and drains the middle median sector. The left median hepatic vein showed a higher degree of variability. In 7 of 15 cases we observed a single left median hepatic vein forming a confluence with the branches of left lateral hepatic vein (Fig 4A and 4B). In 8 of 15 cases we observed two branches, one draining into middle median hepatic vein and the other one formed the confluence with left lateral hepatic vein. This is potentially of surgical importance when creating a surgical transection model using the median lobe as applied for revascularisation studies after ALPPS. Transection along the umbilical fissure leaves the right and middle median hepatic vein to the large right “hemi”-liver, whereas the left median hepatic vein ensures the drainage of the small left “hemi”-liver. In case of one left median hepatic vein, the risk of outflow obstruction after transection is low (Fig 4A and 4B). In contrast and in case of two left median hepatic veins the risk for outflow obstruction is rather high (Fig 4C and 4D).

Bottom Line: Surgically relevant variations were primarily observed in portal venous supply.We showed that lobar borders of the liver do not always match vascular territorial borders.These findings are of importance for the design of new surgical procedures and for understanding eventual complications following hepatic surgery.

View Article: PubMed Central - PubMed

Affiliation: Universitätsklinikum Jena, Klinik für Allgemein-, Viszeral- und Gefäßchirurgie, Experimentelle Transplantationschirurgie, Jena, Germany.

ABSTRACT

Introduction: The intra-hepatic vascular anatomy in rodents, its variations and corresponding supplying and draining territories in respect to the lobar structure of the liver have not been described. We performed a detailed anatomical imaging study in rats and mice to allow for further refinement of experimental surgical approaches.

Methods: LEWIS-Rats and C57Bl/6N-Mice were subjected to ex-vivo imaging using μCT. The image data were used for semi-automated segmentation to extract the hepatic vascular tree as prerequisite for 3D visualization. The underlying vascular anatomy was reconstructed, analysed and used for determining hepatic vascular territories.

Results: The four major liver lobes have their own lobar portal supply and hepatic drainage territories. In contrast, the paracaval liver is supplied by various small branches from right and caudate portal veins and drains directly into the vena cava. Variations in hepatic vascular anatomy were observed in terms of branching pattern and distance of branches to each other. The portal vein anatomy is more variable than the hepatic vein anatomy. Surgically relevant variations were primarily observed in portal venous supply.

Conclusions: For the first time the key variations of intrahepatic vascular anatomy in mice and rats and their surgical implications were described. We showed that lobar borders of the liver do not always match vascular territorial borders. These findings are of importance for the design of new surgical procedures and for understanding eventual complications following hepatic surgery.

Show MeSH
Related in: MedlinePlus