ANATOMY OF PANCREAS

SURGICAL ANATOMY OF PANCREAS by Dr Aamir Hela PG ist Year GMC Jammu

1. ANATOMY OF PANCREAS BY DR AAMIR HELA PG IST YEAR

2. P anc r eas – all f lesh (pan=all and kreas =flesh)

3. I n t r o d uctio n … Soft, lobul a t ed el on g a t ed gland with bot h e x oc r ine and e n docrine fu n ct i ons E x ocr i n e – pancreat i c ju i c e E ndocr i ne - i nsu l in , Glucogan

4. DEVELOPMENT The pancreas develops in two parts, both of which arise from the endoderm of the primitive duodenum. The dorsal bud is the first to appear, as a diverticulum from the dorsal wall of the duodenum. This eventually forms the whole of the neck, body and tail of the gland, together with part of the head.

5. The ventral bud develops more caudally as a diverticulum . Between the fourth and eighth week, the ventral bud rotates posteriorly in a clockwise fashion to fuse with the dorsal bud. T he dorsal duct, the duct of Santorini , opens into the duodenum proximal to the major papilla ( ampulla of Vater ) at the minor papilla, whereas the ventral duct, the duct of Wirsung , which is joined with the lower common bile duct, opens into the major papilla.

6. Lo c a t i o n … epi g a s tric & l e ft h ypo c ho n d r i a c r egi ons beh i n d the s t omach and lesser sa c T r an s v e r se l y ac r oss the po s t erior a b dom in al w a l l a t the l e v el o f L 1 - L3

7. Si z e a n d shape… J shap e d or ret ort shap e d. Len g t h - 15 -20 cm Thicknes s - 1. 2 -1.8 cm • B r ea d t h - 2. 5 -3 . 8 cm Wt - around 90 gm

8. P arts …

9. H e ad … En l a r g ed par t C shaped , lyi n g wit h in the c on c a vity of duodenu m, c ons i s t of 3 bo r de r s - supe r i or ,i n f eri o r & rig h t l a t e r al 2 sur f ace s - a n t eri o r & po s t eri or uncin a t e p r o c ess

10. Head … Superior bo r de r - -1 s t par t o f duoden um -Sup . panc r e a ti c odu d enal A. I n f erio r bo r de r - -3 r d par t o f duoden um - I n f . panc r e a ti c odu d enal A. Rt. l a t e r al bo r de r - -2 nd par t o f duoden um - T erm i na l par t o f b il e duct -Ana s t omosi s b e tn 2 ar t er i es.

11. Head… A nt erio r sur f ace 1 s t par t of duodenu m . T r an s v e r se c o l on Jejunum sepa r a t ed b y per i t otneum .

12. S t omach Lesse r ome n tum Lesse r sac

13. H e ad… P o s t erio r sur f ace: I V C Rig h t R enal v ei ns Rig h t crus of d ia p h r agm Bi l e duct

14. Un c in a t e p r o ces s … T r i angul ar p r oject i on wh i ch a r i s e s f r om l o w er a n d l e f t part of the bod y . R el a ti o ns: A n t erior: - Sup e r i o r m ese n t e r i c v esse l s. P o s t eri o r - Aor t a A b o v e - L e f t r e n al v e i n f

15. Ne c k … R el a tions: A n t erio r sur f ace P eri t oneum c o v eri n g l es s er sac P yl orus

16. Ne c k … P o s t erio r sur f ace is r el a t ed t o superior mese n t eri c v ein por t al v ein

17. Body… E l on g a t ed part. E x t ends f r o m neck t o the t ail. P as s es t o w a r d the l e ft with s l ig h t u p w a r d and back w a r d i nc l i n a t i on

18. Body… T riangu lar i n c r oss secti on 3 bo r de r s- - A n t er ior - su per i or - I n f er ior T uber ome n t ale - sma l l p r oject ion o n su p er io r bo r der l i t tle t o the l e f t of the neck

19. Bod y- R el a tio n s … Bo r de r s : A n t erio r a t t ach t o r oo t o f t h e t r a n v e r se meso c o l o n . S u p e rio r r el a t ed t o c oe liac tr u nk, hep a t i c a r t e r y & sp l en i c ar t ery I n f erio r is r el a t ed t o supe r i o r mese n t eric ar t er y .

20. Bod y- R el a tio n s … Sur f aces: A n t erio r is c o n v e x c o v e r ed by t he per i t oneu m r el a t ed t o the l esser s ac & s t o m a c h. In f e r ior sur f ace c o v e r ed b y t h e per i t oneum r el a t ed the D J f l e x u r e c o ils o f jejunu m & L t. c o lic f l e x u r e.

21. Body – r el a tio n s … P o s t er i or su r f a c e -Aor t a - L e f t crus o f the d iaph r agm - L e f t k i dn e y - L e f t Sup r a r enal gland - L e f t r enal v esse l s - Sp len i c v ein

22. T ail … L e f t e n d o f t he panc r eas L ies in the lien o r enal li g ame n t , t o g e th e r with the splenic v es s els R el a t ed t o the l o w er par t o f the sp l ee n ( g a s tr i c sur f ace.

23. Du c t s y st e m … E x ocrine part o f p an c r eas is d r ai ne d b y the 2 ducts Main Ac c esso r y .

24. Mai n panc r e a tic duct of wi r sun g … L ies n e ar po s t eri or sur f ace ,3 mm in d iam . wh i t e in c o l our Begi n s a t t h e t ail, runs th r ou g hou t the body ,bends a t the nec k t o run dow n w a r ds back w a r d s in the head. Herring bone pat t ern

25. Herri ng bone pattern …

26. . In the hea d o f the panc r eas, i t i s r e l at ed t o the bi l e duct(o n rt. s i d e) T w o d uct s ope n i n the w all o f the 2 nd par t of the duo d enum and jo in t o f orm hepa t opancreatic am p ulla o f va t e r whi ch ope n as major duo d enal papi l la,8-10 cm di s t al t o p y l orus.

27. Acc e ss o r y duct of Sa n t orin i … Begi n s in the l o w er par t o f head , c r osses the main duc t with wh i ch it c ommun i c a t es Open s as min o r duodenal papi l la in the 2 nd part of duodenum ( 6 -8 cm d i s t al t o p yl orus)

28. Ar t erial supply… - Sp len i c A. - Super i o r panc r e a t i c o - duodena l ar t e r y (f r o m c oe liac tr u nk) -I n f eri o r panc r e a t i c o - duode n al A .(f r om super i o r mese n t eric A)

29. V e n ous d r ai n a g e … - Sp len i c v ein - Sup e ri or mese n t eric v ein - P or t al v ein

30. Ne r v e supply… P a r a s ym p a th e t i c b y the v agus ne r v e c o n t r o lli n g sec r e t i o n . S ymp a th e t i c f r om coel i ac & su p erior mese n t er i c plx. S e c r e t i o n is al so c o n t r o lled b y harm o ne se c r e tin- panc r e o z ymin e .

31. L y mphatic drain a g e … Hea d & nec k – v e n t r al & do r sal panc r e a tic o duden a l gr p LN. Body & t ai l b y panc r e a tic o -sple n ic LN. E f f e r e n ts t o Co e li a c & sup.mese n t eric LN

32. DEVELOPMENTAL ANOMALIES PANCREATIC DIVISUM Most common congenital anomaly Results from failure of dorsal and ventral ducts to fuse Detected in 5% to 10% of population in autopsy studies ANNULAR PANCREAS Rare congenital anomaly Ring of pancreatic tissue surrounds the duodenum May be partial or complete 1 in every 12 000 to 15 000 live births

33. ECTOPIC PANCREAS Described as pancreatic tissue that lacks anatomic or vascular continuity with the normal pancreas. Usually asymptomatic and occurs as incidental finding. AGENESIS AND HYPOPLASIA Total agenesis is extremely rare and incompatible with life. Hypoplasia result from absence of ventral or dorsal pancreatic bud.

34. ACCESSORY PANCREATIC LOBE Extremely rare anomaly Accessory lobe of pancreatic tissue originating from main pancreatic gland. May contain an aberrant duct ANSA PANCREATICA Rare anatomical variation. Communication between main pancreatic and accessory pancreatic duct. Predisposing factor in patients with idiopathic acute pancreatitis.