LIVER SEGMENTS Sidoun M Surgery department MCC

ANATOMICAL CLASSIFICATION:the falciform ligament, the most obvious surface marker of the

liver, was used as the division of the right and left lobes of the liver, this description is inaccurate and of minimal usefulness to the surgeon and radiologist .

Surgical classification:(James Cantlie, Scottish surgeon1851-1926 ) cantlie line extending from the gallbladder to the left side of the inferior vena cava, representing bloodless area that can be considered to divide the liver into left and right parts.(The French surgeon and anatomist Claude Couinaud) classification system uses the vascular supply in the liver to separate the functional units (numbered I to VIII)The hepatic veins are at the periphery each segment, portal triad at center each segment

RIGHT LOBE :ANTERIOR 5,8 POSTERIOR 6,7LEFT LOBE :MEDIAL 4A AND B LATERAL 23SEGMENT 1 IS POSTERIOR TO THE LIVER ,ANTERIOR AND LATERAL TO IVC (CAUDATE)IN THE CENTER OF ALL SEGMENTS OF THE LIVER FROM POSTERIOR,

PORTAL VEIN BRANCHES :

IVC TRIBUTARIES FROM LIVER

The right hepatic vein runs at the right hepatic fissure and drains segments V, VI, VII and VIII. The plane of the right hepatic vein separates the segments VI and VII posterior and segments VIII and V anterior .

The middle hepatic vein runs at the middle hepatic fissure and drains segments IV, V and VIII. The plane of the middle hepatic vein separates the segments VIII and V from segment IV

left hepatic vein runs partially at the fissure for the ligamentum teres and at the left hepatic fissure , drains segments II, III, and IV. the plane of the left hepatic vein separates segment IV from segments II and III.

CT SCAN CLASSIFICATION OF LIVER :Important land marks :1. Caudate lobe :direct contact to the IVC2. Spleen ,stomach ,splenic and hepatic flexure ,ivc inside the liver,

____from medial to lateral 2,4a,8 ,7 (upper)3. Splenic vein,main portal vein,pancreas :the inferior segments 5,6 4. Gall bladder between s 4 ,5 5. Liver fissures :medially fissure for ligamentum teres ( start on the

costal surface of liver as falciforum ligament ) divide left lobe medially s and lateral s\ laterally is fissure for portal vein ,the gall bladder lies in this fissure (continuation anterior to the caudate) to be fissure for ligamentum venosum separate the caudate from the left lobe .

RIGHT HEPATECTOMY RIGHT HEPATIC FISSURE

Posterior segments

anterior segments

LEFT HEPATECTOMY

REFERENCES:

1. O. Al-Jiffry Bilal and Khayat H. Samah (2013). Segmental Oriented Liver Surgery, Hepatic Surgery, chapter 9

2. Craig Hacking , Omar Bashir et al. (n.d)hepatic veins , radiopedia.org , https://radiopaedia.org/articles/hepatic-veins

3. Segmental liver anatomy (n.d) retrived from http://snmmi.files.cms-plus.com/docs/PET_COE/off_the_wall/Segmental.pdf

4. Video retrived from tvasurg.com , http://pie.med.utoronto.ca/TVASurg/TVASurg_content/surg/PL_standardRightHepatectomy.html

5. Second video retrived from , https://www.youtube.com/channel/UCJQWLA8-dDPqJc3COrFYi-w