The liver is the largest gland in the body and consists of both exocrine and endocrine parts. It is wedge shaped with broad base directed to the right. It occupies whole of the Rt.hypochondrium, upper part of the epigastric and part of the left hypochondrium up to left lateral plane. In male it is usually weighs from 1.4 to 1.8 kg and in female it weighs from 1.2 to 1.4 kg. Owing to great vascularity, wounds of liver cause considerable haemorrhage. In spite of its great weight it is maintained in position by falciform ligeament, which is a fold of peritoneum streching from posterior aspect of anterior abdominal wall and goes under surface of the diaphragm the comes down and attach to the antero - superior surface of the liver and secondly the three main hepatic veins which drains blood from the liver to interior venacava and lastly supported by intra - abdominal pressure to keep the liver in its position.

Biliary drainage of liver flows into the right and left hepatic ducts, which joins to form the common hepatic duct ( CBD) located near the portal vein. The hepatic venous drainage consists of a few sizable and several smaller branches that flow directly into the inferior venacava. The posterior edge of caudate lobe on the left side commonly exhibits a fibrous attachment expanding behind the venacava towards 7^th segment. In a substantial number of individuals the filrons band is replacd by liver paren - chyma thay can circumferentially envelope the inferior vena - cava.

Knowledge of normal and variant anatomy of caudate lobe is prerequisite for better surgical outcome. Morphology of caudate has significance in diagnostic imaging and also minimally invasive surgical approaches.

REVIEW OF LITERATURE

1. Kupffer (1898) The hepatic sinusoids are lined by endothelium instead of the endothelium macrophages. They are present called as stellate cells of
2. Regarding the hepatic lobes, the classical studies of Hjortsjo (1948, 1951, and 1956) upon the segmental branching of bile ducts, hepatic artery and portal vein within the liver have emphasized that the primary anatomical and functional lobation is better defined by the distribution of the right and left hepatic ducts
3. Hilliard J Catz , A Justin Williams ( 1952 ) investigated on Accessory lobes of liver and their significance in roentgen diagnosis.
4. Glancer (1953) There is no anastomosis between hepatic arterial territories and hence each branch is an end artery.
5. The hepatic artery, portal vein and common bile duct divide and sub divide upon a common pattern as is implied in the classical observation of Glission (1954)
6. Doljansky(1960) The nucleus present in the hepatocytes is spheroid and euchromatic, polyploidy or multiples within each cell.
7. Sutherland (1965) Nerve fiber both myelinated and non myelinated also reach the liver parenchyma from nerves in the various peritoneal folds of the organ.
8. Rapport (1969) has also proposed multiple units (compound portal acini) for more complex groups of hepatic units
9. Nidden et.aI (1973) The importance of the trans diaphragmatic lymph drainage of the liver into the internal mammary and diaphragmatic lymph nodes.
10. Dawson (1974) and others considered resection of less than a lobe as hazardous while others such as Ryncki (1974) have recorded succesfull segmental resection.
11. Yong Ho Auh et al. (1983) conducted a detailed study on CT of papillary process of the caudate lobe of liver. For the purpose abdominal CT scans of 50 consecutive patients were reviewed. For each examination, the appearance of papillary process was noted as well as its relation to the adjacent liver, portal vein, inferior venacava, pancreatic body and gastric antrum. Along with this frequency and morphology of papillary — caudate process separation were analyzed.
12. P P Anthony and P U Telesinghe ( 1986 ) studied Inflammatory Pseudo tumour of liver
13. Ryuji Mizumoto et al. (1988) investigated the portal triad around the hepatic hilum including the caudate lobe using 106 adult cadavers. Branching pattern of portal vein at hepatic hilum, hepatic artery, cystic artery, accessory bile duct and attachments of round ligament were encountered in this study.
14. 1Wylie J Dodds et al. (1990) deals with the anatomy, embryology and pathology of caudate lobe. The pitfalls in clinical imaging were also noted.
15. Fosterin (1995) in his review of liver surgery in 1991, total hepatectomy with liver transplantations said that it may be most difficult operations ever divised technically and physiologically.
16. Ernerst E More , Thomas H Cogbill , Grigory J Jurkovich et.all ( 1995 ) analysed Organ injury Scaling (OIS) , Spleen and Liver in order to devise injury severity scores for individual organs to facilitate clinical investigation.
17. K Kogure et al (2000) performed a study to clarify the interrelations among portal segmentation, hepatic venous system and external notch of caudate lobe. A total of 88 formalin fixed human livers were dissected to visualize the same. The patterns of portal branches were also classified. In this study Kumon's segmentation was applied to the anatomical description of caudate lobe.
18. Murakami and F Hata (2002) give special emphasis on parts of caudate lobe and its surgical importance in their study on human liver caudate lobe and segment. They had also described the margins of the lobe, border branches of portal vein, and other topics closely relating to the surgery within these contexts.
19. Eddie K Abdulla et al. (2002) describes the implications of embryology and anatomy for surgery in the caudate lobe. To enhance the knowledge base of relevant surgical anatomy and to support the indications for partial or total caudate lobe resection, this article presents a synthesis of the existing anatomic, embryologic and clinical data about caudate lobe.
20. Arne Jorn Lemke , Martin Julius Brinkman , Thomas schott and Stefan Markus Niehues ( 2006 ) worked on Preoperative CT Volumetric Measurement for Calculation of Intraoperative Weight and Volume of a living donors right liver lobe.
21. Nagato et al. (2011) carried out a medical investigation in anatomical variations exhibited by 61 formalinised and glycerinated adult human liver. They classified the vast majority into 7 morphological liver types and also two additional liver types were identified and described. Parameters associated with the normal morphological aspects of organ surfaces were also assessed.
22. Ghanshyam Dev, Reshmi Sharma and Bhawna Sharma (2014) reported variations in hepatic papillary process using CT scans in patients undergone cholecystectomy and some other surgical procedures. Hepatic mass lesion, hepatosplenomegaly and other clinical conditions along with chances of misinterpretations in CT scans were also considered in this study.
23. Sarala HS, Jyothilakshmi TK and Subha R (2015) taken up a study on morphological variations of caudate lobe of liver and their clinical implications. For the purpose 100 formalin fixed adult livers were taken into consideration. Morphological variations such as various shapes, prominent processes, presence of fissures etc were encountered.
24. Mandeep Gill Sagoo, Claire and Edward Gosden (2015) had done a detailed study on caudate lobe of liver by considering its morphology and morphometry in two different populations, North West and UK. This study shows that significant population differences exist in several metrics and morphological features of liver and how it affects the calculation of hepatic indices resulting in a greater percentage of false positives of cirrhosis in northwest population.
25. D . Kemp , Kurt L Zimmerman , D L Panceira , W E Monorie and M S Leib ( 2015 ) Histopathologic variations between liver lobes in dogs .

METHODOLOGY

The present study deals with morphological variations of caudate lobe of liver in 108 formaline fixed adult livers. The study started from the department of anatomy, Kanyakumari medical mission college and research, Muttom, Tamilnadu. By collecting and analysing the samples and collected detail data of caudate lobe and its morphology. Since my medical college 2 year old. I have collected only the 8 samples from the college. The remaining samples from various medical colleges of South India. In which 30 samples collected from JSS medical college Mysore, Karnataka and analysed  the data, another 20 from Alazar medical college and super speciality hospital, Thodapuzha, Kerala under the supervision of H.O.D anatomy and again took help from sree - gokulam medical college and research foundation, vanjaramood, Trivendrum Kerala under the guidence and supervision of prof, Anilkumar K V helped to provide 20 specimans.

To conclude my sample collection, finally I went to srinivasa institute of medical sciences under the supervision by Dr. Sathiskumar prof of anatomy and vivekananda institute of medical college Tiruchengud, Tamil nadu, Narayana medical college and hospitals, Nellore and under the guidence of my proffessor lastly, the entire my sample collection helped by Dr. Parikanksh S V and which is more useful for carry out my research work from above said colleges collected 10 samples under the supervision by their  H O D of anatomy. Each sample is analysed throughtly and find out variations in shapes of caudate lobe, prominence of vertical fissure, presence and absence of processes etc were noted clear photographs of caudate lobe of all the 108 samples were taken and added to my data.

DISCUSSION

In classic description, the caudate lobe is a projection from the posterior hepatic surface that is elongated vertically. It is bounded on the left by the fissure for ligamentum venosum, anteriorly by porta - hepatis and on the right by the groove for inferior venacava. With recent progress in hepato - billary surgery, the importance of caudate lobe in human liver has been increasingly recognised and anatomical peculiarities of caudate lobe resection have been reported. Caudate lobectomy, either as an isolated procedure or more frequently as a component of major hepatectomy is frequently indispensible in radial tumous elimination. The papillary process of caudate lobe is a potential source of pitfalls in interpretation of CT images. These errors can be avoided if the CT images are analysed carefully with reference of morpholgical variations of caudate lobe of liver. Many authors have previously described variations in the morphology of caudate lobe as it is important information for any clinical practioners treating liver disorders. The incidence of morphological variation of caudate lobe is very high in this study. These variations should be kept mind in order to achieve correct pre - operative diagnosis.

The variations are clinically important for hepato - biliary surgery, liver transplantation and radiological interpretation understanding the anatomical diversity of the caudate lobe can help surgeons and clinicians to avoid complications during hepatic procedure.

RESULTS

Hense by analysing the variation in shape of caudate lobe of the liver concluded that the most common shape was recangular which was founded to be 35% in the study population followed by the analysis of presence and absence of vertical  fissures concluded that when 50% showed prominent vertical fissures while in the other 50% it was absent. The study of caudate and papillary processes concluded that the caudate processes was prominent in 44% of liver specimens while 42% showed prominent papillary process.

CONCLUSION

The caudate lobe demonstrates significant anatomical diversity due to its unique anatomical location in the liver and its characterstic configuration which resembly a joining pin of a fan. Knowledge of these variations is important for all Anatomists, radiologists and hepato billiary surgeons particularly in liver resection and transplantation procedures and also combined with major hepatectomy procedure, so treat hepato - cellular carcinoma and hepatic hilar bile duct cancer. So this study has been taken up to briefly review the morphology of caudate lobe resection and combined with major hepatectomy procedures, so treat hepato cellular carcinoma and hepatic hilar bileduct cancer.Hence I have taken up this study to brief and review the morphology of the caudate lobe of the liver.

REFERENCES

1. Sagoo M G, ALAND R C, Gosden E. Morphology and morphometry of the caudate lobe of the liver in two populations. Anatomical Science International. 2018;93(1):48-57. DOI: 10.1007/s12565-016-0365-7.
2. Sarala HS, Kariyappa JT, Shubha R. Morphological variations of caudate lobe of the liver and their clinical implications. International Journal of Anatomy and Research. 2015;3(2):980-983. DOI: 10.16965/ijar.2015.119.
3. Sabnis A. Anatomical variation in caudate lobe of liver A cadaveric study. Journal of Population Therapeutics and Clinical Pharmacology. Discusses rectangular, square, triangular, oval, pyriform, and irregular caudate lobes with accessory fissures and processes.
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7. Donoso L, Martinez-Noguera A, Zidan A, Lora F. Papillary process of the caudate lobe of the liver: Sonographic appearance. Radiology. 1989;173(3):631-633. DOI: 10.1148/radiology.173.3.2682770.
8. Abdalla EK, Vauthey JN, Couinaud C. The caudate lobe of the liver: implications of embryology and anatomy for surgery. Surgical Oncology Clinics of North America. 2002:11:835-848.
9. Gray's Anatomy Standard reference for gross anatomy of liver and caudate lobe boundaries.
10. Couinaud Claude Couinaud's segmental anatomy classification is essential for discussing Segment I (caudate lobe).
11. Standring S (Ed.). Gray's Anatomy: The Anatomical Basis of Clinical Practice. Latest edition.