MORPHOLOGICAL STUDY OF ADULT HUMAN CADAVERIC LIVER

Address for Correspondence: Dr. Mohini M. Joshi, Associate Professor, Department of Anatomy, Rural Medical College, Pravara Institute of Medical Sciences Loni, Dist. Ahmadnagar Maharashtra, India. Mobile No: +919823064062, E-Mail: atharvamohini@gmail.com Background: The liver is the largest of the abdominal viscera, occupying a substantial portion of the upper abdominal cavity. It is essential to have knowledge of the normal and variant liver anatomy. Objective: Objective of the present study was to study morphology of liver and its variations. Materials and Methods: The hundred liver specimens available in the department of Anatomy were studied. The liver specimens were numbered and photographs were taken along with proper documentation. Caudate and quadrate lobes of the liver were studied in detail for the size, shape, accessory fissures, and accessory lobes. For each of the parameters, the mean, standard deviation (S.D.) and range (minimum value-maximum value) was calculated. Result: The mean length of the caudate lobe was 5.33±1.01, breadth 2.75 ±0.65 and depth 1.93±0.55 while length of the quadrate lobe was 5.91±1.18 and breadth 3.00±0.80. The mean length of the right lobe was 13.62±2.23, breadth 8.13±1.45 while length of the left lobe was 12.20±2.12 and breadth 7.65±1.51. Morphological variations like caudate process, accessory fissures, Pons Hepatis, lingual process, papillary process, accessory lobes and variations in shapes of caudate and quadrate lobes were observed and reported. Conclusion: This study highlights some of the variations in the lobes and fissures of the liver. Various shapes of the caudate lobe and quadrate lobe were encountered. Knowledge of anatomical and morphological variations of liver is important for anatomist as well as for radiologist and hepatobiliary surgeons.

quadrate lobes by the surface peritoneal and ligamental attachments [1].It is essential to have knowledge of the normal and variant liver anatomy as it is a prerequisite to having a favorable surgical outcome and commonly occurring variations assumes even more significance in the era of diagnostic imaging and minimally invasive surgical approaches.Hepatic The liver is the largest of the abdominal viscera, occupying a substantial portion of the upper abdominal cavity.It occupies most of the right hypochondrium, epigastrium, and frequently extends into the left hypochondrium as far as the left lateral line.The liver has been considered to be divided into right, left, caudate and imaging is usually performed to search for primary or metastatic liver diseases [2].The major fissures are important landmarks for interpreting the lobar anatomy and locating the liver lesions.Variations can have a clinical presentation or indicate an underlying pathological condition.Detailed studies of the macroscopic anatomy of cadaveric livers can still contribute to the identification of important anatomical variations.With this background in mind the present study was carried out on cadaveric liver to study morphology and its variations.

RESULTS
The study was approved by Institutional Ethical Committee.The 100 liver specimens were obtained from adult human embalmed cadavers during routine dissection in the department of anatomy at a tertiary care teaching hospital.They were preserved in 10% of formalin.Cadaveric liver in good state were utilized for study and those which are damaged were omitted from study.The liver specimens were numbered and photographs were taken along with proper documentation.Caudate and quadrate lobes of the liver were studied in detail for the size, shape, accessory fissures, and accessory lobes.The mean length of the right lobe was 13.62±2.23,breadth 8.13±1.45while length of the left lobe was 12.20±2.12and breadth 7.65± 1.51.(Table1) Six liver specimens were having right lobe smaller than left lobe and superficial veins on the surface of liver were observed in 15% of specimens.The Morphological features/ variations of liver can be seen in Table 2.These data suggest a high incidence of anatomical variation in the human liver.Caudate process was observed in 52%.Accessory fissure on inferior margin of caudate lobe was seen in 20% and accessory fissure along the middle of fissure for ligamentum teres             The shapes of the caudate lobe and quadrate lobe showed wide range of variations.The caudate lobe was rectangular in 68%, triangular in 16%, pear shaped and cuboidal in 4%.The quadrate lobe was rectangular in 74%, triangular in 9%, pear shaped and elongated in 5 % (Table 3).
In the present study, the caudate process was present between the porta hepatis anteriorly and the fossa for the inferior vena cava posteriorly in 52% of specimens.Sahni et al found that the caudate process was present in 119 (59.5%) specimens [3].Accessory fissure on inferior M.Joshi, Sushama K. Chavan.MORPHOLOGICAL STUDY OF ADULT HUMAN CADAVERIC LIVER.
margin of caudate lobe was seen in 20% while accessory fissure along the middle of fissure for ligamentum teres in 34% of quadrate lobe.Joshi et al reported an incidence of 30% [5].Sunitha et al reported an incidence 15.5% of accessory fissure on quadrate lobe [6].Auh et al reported that the accessory hepatic fissures are potential sources of diagnostic errors during imaging such as; collection of fluid in these fissures may be mistaken for a liver cyst, intrahepatic haematoma or liver abscess.[7] Accessory fissures can be caused by gastric volvulus, diaphragmatic hernia, portal hypertension, obstructive pulmonary disease, hypertrophic diaphragmatic bundles or rarely by the pressure of adjacent organs and structures (due to the fact that adjacent structures usually leave an impression but not a fissure) [5,8,9].They can be markers of hepatic "weak zone" -an area with low vascularization which can be useful during resection [10,11].These fissures are also important in today's laparoscopic minimally invasive techniques and segmental resection of liver.
Pons hepatis was found in 13% of specimens.Saritha et al [12] have reported the incidence of pons hepatis in 4% of livers while Patil et al [13] found it in 10% of specimens examined.Joshi et al found a higher incidence (30%) of Pons hepatis [5].Prominent papillary process was observed in 5(5%) of the livers.Joshi SD et al have reported prominent papillary process in 33% of the livers in their study [5].In present study, there was an absence of quadrate lobe in 2 and caudate lobe in one liver specimen.square and inverted pear-shaped.The shape of quadrate lobe was rectangular in 66% and in 6% of the cases, the quadrate lobe was very narrow [5].Sarla et al (2015) in their study found rectangular shape in 58%, pear shape in 10%, irregular in 20%, and triangular in 8% [16].Lingular process was observed in 10% of the livers.Ranjana Singh et al reported tongue like projection of left lobe in 9 livers (15%) [17].

REFERENCES
This study highlights some of the variations in the lobes and fissures of the liver.Occurrence of accessory fissures is very common.Various shapes of the caudate lobe and quadrate lobe were encountered.Knowledge of anatomical and morphological variations of liver is important for anatomist as well as for radiologist and hepatobiliary surgeons.

2 4 Accessory
Accessory fissure on inferior margin of caudate lobe 20(20) 3 Quadrate lobe-accessory fissure along the middle of fissure for ligamentum teres 34 (34) Fissure on the liver surface extending from the right margin of porta hepatis into the inferior surface of the right lobe 19 (19)5Fissure present along center of quadrate lobe 5 Mohini M.Joshi, Sushama K. Chavan.MORPHOLOGICAL STUDY OF ADULT HUMAN CADAVERIC LIVER. in 34% of quadrate lobe.Accessory Fissure on the liver surface extending from the right margin of porta hepatis into the inferior surface of the right lobe was observed in 19%.[Fig.1-6].Pons hepatis (PH) was found in 13%.[Fig.4-6]Accessory lobes were present in 5% of specimens.[Fig.6-7]Lingual process was found in 10% [Fig 2 & 8].Papillary process was present in 5% of specimens [Fig 9].Other variations noted were appendix of liver in one specimen, an absence of quadrate lobe in 2 and caudate lobe in one liver specimen and diaphragmatic or costal grooves in 2 specimens [Fig 10, 11 and 12].

Fig. 10 :
Fig. 10: Appendix of liver and fissure separating accessory lobe at the top of left lobe.

Table 1 :
Measurements of lobes of the liver.

Table 3 :
Shapes of the Quadrate and Caudate Lobes of the liver.