OS 206 Duodenum, Pancreas & Spleen (PDF) UPCM 2024-2025

OS 206: ABDOMEN AND PELVIS DUODENUM, PANCREAS, AND SPLEEN UPCM 2029 | Dr. Ronnie E. Baticulon | LU3 A.Y. 2024-2025 OUTLINE I.​ Duodenum III.​ Spleen A.​ Functions...

OS 206: ABDOMEN AND PELVIS DUODENUM, PANCREAS, AND SPLEEN UPCM 2029 | Dr. Ronnie E. Baticulon | LU3 A.Y. 2024-2025 OUTLINE I.​ Duodenum III.​ Spleen A.​ Functions A.​ Ligaments B.​ Segments B.​ Vasculature, C.​ Vasculature, Lymphatics, & Lymphatics, & Innervation Innervation C.​ Clinical Correlates D.​ Clinical Correlates IV.​ Vasculature Summary II.​ Pancreas V.​ References A.​ Parts of the Pancreas B.​ Pancreatic Ducts C.​ Vasculature, Lymphatics, and Figure 2. Ligament of Treitz (green) Innervation ​ The duodenum ends at the duodenojejunal flexure ​ Demarcated from the stomach by the pylorus and from the I.​ DUODENUM jejunum by the ligament of Treitz ○​ Pyloric sphincter ​ Prevents the reflux of contents of the duodenum back into the stomach ○​ Ligament of Treitz ​ Ligament at the duodenojejunal flexure that suspends it from the abdominal wall A.​ FUNCTIONS ​ Transmits the contents from the stomach ​ Continues digestion from the stomach ○​ Digestive processes have already occurred in the stomach (continued from the oral cavity) [2027 Trans] ​ Produces hormones ○​ Secretin and Cholecystokinin ​ Walls contain disaccharidases (maltase, sucrase, lactase) & dipeptidases [2026 Trans] ​ Digestion of triglycerides into monoacylglycerol and free fatty acids [2026 Trans] Figure 1. Internal Anatomy of the Duodenum ​ Pancreatic Duct ​ C-shaped tube representing the first and most proximal part of →​The pancreas has an exocrine function the small intestines ​ Secretes pancreatic enzymes (pancreatic amylase and ○​ C-shaped hugs the head of the pancreas pancreatic lipase) ○​ It begins where the stomach ends −​ These enzymes are released into the pancreatic duct ○​ Ends in the Duodenojejunal Flexure suspended from the which empties into the duodenum Ligament of Treitz ​ Common Bile Duct[2026 Trans] ​ Embryology: Derivative of the foregut →​Secretes bile for fat emulsification ○​ The foregut is supplied by the celiac trunk →​Bile acids derived from cholesterol (cholic acid and ​ Called duodenum because it is 12-finger breadths in length chenodeoxycholic acid) ○​ From “duodecimal” = base 12 ​ If you have a problem in the duodenum, bile, and pancreatic ​ Approximately 25-30 cm long enzymes won’t reach the ingested food material ​ Lies mostly in the retroperitoneum immediately adjacent to the →​This leads to digestive problems head and inferior border of the body of the pancreas ​ Begins absorption of monosaccharides and amino acids via ○​ Only 1st segment is intraperitoneal, while the 2nd, 3rd, and 4th enterocytes [2026 Trans] segments are retroperitoneal →​Fat is absorbed in the ileum →​Water and electrolytes are absorbed in the colon/large Retroperitoneal vs Intraperitoneal Analogy (By Sir Baticulon) intestine ​ Peritoneum - covers the peritoneal cavity ​ Imagine the abdomen as a glass bottle B.​ SEGMENTS ​ Intraperitoneal ​ Four segments: ○​ Imagine a bottle with students inside it. Then, you put a ○​ Superior Segment balloon in the bottle, and then late students enter the balloon. ○​ Descending Segment ○​ All the late students inside the balloon are intraperitoneal ○​ Inferior Segment ○​ Intraperitoneal organs are freely floating in the abdomen ○​ Ascending Segment (mobile) ○​ E.g. stomach, first segment of the duodenum ​ Retroperitoneal ○​ When you inflate the balloon inside the bottle, the tendency is the early students will be pushed against the walls of the classroom ○​ Students along the walls are retroperitoneal ○​ All retroperitoneal organs or tissues are those that are between the peritoneum and the abdominal wall ○​ Retroperitoneal organs are plastered to the abdominal wall ○​ Retroperitoneal organs are relatively fixed within the abdomen (immobile) ○​ E.g. 2nd, 3rd, and 4th part of the duodenum ​ Clinical Significance: ○​ Intraperitoneal organs when injured, bleed more (compared to retroperitoneal organs) and fill the intraperitoneal cavity with blood ○​ Retroperitoneal organs bleed less and blood stays in the retroperitoneal cavity Figure 3. Segments of the Duodenum (highlighted in yellow) (Enlarged in the Appendix) Trans 4 TG15: Khu, Kiunisala, Laurente, Lui, Lunaria, Luz, Mabute TH: Kiunisala 1 of 10  SUPERIOR SEGMENT (1ST) ​ Length: 5cm, anterolateral to the body of L1 ​ Suspended by: ○​ Superiorly and Proximal: Hepatoduodenal Ligament ○​ Inferiorly: Greater Omentum ​ Contains the Portal Triad: ○​ Common bile duct ○​ Hepatic artery proper ○​ Hepatic portal vein ​ Clinical Significance: Cholecystectomy ○​ The portal triad must be identified to avoid it and ensure that the structure ligated is towards the gallbladder ​ Hepatic portal vein ○​ Carbohydrates and proteins are absorbed in the small intestines ○​ Veins from the small intestine lead to the portal vein to deliver nutrients to the liver Figure 5. Superior mesenteric artery → Inferior pancreaticoduodenal artery ○​ Meaning, carbohydrates go to the liver first Additional information (Sir Baticulon): ​ Left Gastric Artery and Right Gastric Artery supply the lesser DESCENDING SEGMENT (2ND) curvature of the stomach ​ 7-10 cm, descends along right L1-L3 ​ Left and Right Gastroepiploic (also called Gastroomental) ​ Location of the common bile duct and the main pancreatic Arteries supply the greater curvature ducts: ​ Greater omentum looks like an apron that hangs over your ○​ Major Duodenal Papilla (of Vater) stomach ​ Entry of major pancreatic ducts (of Wirsung) and common bile →​If you lift it up, SMA is seen along with the Inferior duct and where these ducts empty their contents (UPCM 2028) Pancreaticoduodenal Artery that supplies the head of the ​ Dilation called Ampulla of Vater is seen pancreas and the distal segment of the duodenum ​ Common bile duct empties into the Ampulla of Vater ​ Pylorus is an actual sphincter and is also called the pyloric ○​ Minor Duodenal Papilla sphincter ​ Entry of minor/accessory pancreatic duct (of Santorini) →​Can help in identifying the duodenum ​ Inconsistent and more difficult to find →​Jejunum is usually in the left upper quadrant ​ Clinical Significance: A mass/tumor in this region will block the →​Ileum is usually in the right lower quadrant secretion of bile and pancreatic enzymes ○​ Can manifest as jaundice due to backflow Embryology[2027 Trans] ○​ Can also manifest as pancreatitis (inflammation of the ​ The intestinal tract has three major arteries and the following pancreas) are their derivatives: →​Celiac trunk — artery of the foregut INFERIOR SEGMENT (HORIZONTAL/3RD) →​Superior mesenteric artery — artery of the midgut ​ 6-8 cm, crosses L3 →​Inferior mesenteric artery — artery of the hindgut ​ Has important blood vessels at the dorsal and ventral surfaces ○​ Anteriorly: Superior Mesenteric Artery (SMA) and Superior VENOUS DRAINAGE Mesenteric Vein (SMV) ​ Veins simply follow the arteries ○​ Posteriorly: Descending Aorta, Inferior Vena Cava (IVC), right ​ Superior Pancreaticoduodenal Vein psoas major, and the right testicular or ovarian vessels ○​ Drains to the Portal Vein ​ Inferior Pancreaticoduodenal Vein ASCENDING SEGMENT (4TH) ○​ Drains to the Superior Mesenteric Vein, draining eventually to ​ 5 cm, begins at the left of L3 and ascends to superior L2 the portal vein ​ Suspended by the Ligament of Treitz LYMPHATIC DRAINAGE C.​ VASCULATURE, LYMPHATICS, & INNERVATION ​ Pancreaticodiuodenal nodes upward to gastroduodenal nodes to celiac nodes, downward to superior mesenteric nodes INNERVATION ​ Parasympathetic nerves: hepatic and celiac branches of the anterior and posterior vagus nerves, respectively ​ Sympathetic: branches of the celiac plexus D.​ CLINICAL CORRELATES FLUOROSCOPY ​ Fluoroscopy involves swallowing a radio-opaque material containing barium sulfate, i.e., barium swallow ○​ Metallic compound which is easily visualized on X-rays Figure 4. Celiac Trunk and its branches(Sanders, 2024) ​ Supplied by the Celiac Trunk (supplies the foregut) ○​ Branches: ​ Left gastric artery ​ Splenic artery ​ Common hepatic artery ​Right gastric artery ​Gastroduodenal artery ○​ Supplies the distal end of the stomach and duodenum ○​ Branches into: Superior Pancreaticoduodenal Artery ​ Superior Pancreaticoduodenal Artery ○​ Supplies the duodenum proximal to the entry of the bile duct ○​ Has anterior and posterior branches ○​ Remember: Celiac trunk → Common hepatic artery → Gastroduodenal artery → Superior & Inferior pancreaticoduodenal artery Figure 6. Fluoroscopic Imaging ​ Superior Mesenteric Artery ○​ Also derived from the aorta BLUNT ABDOMINAL TRAUMA ○​ Gives rise to the Inferior Pancreaticoduodenal Artery ​ In blunt abdominal trauma, duodenal injuries are often associated ​ Supplies the duodenum distal to the entry of the bile duct with pancreatic injuries ​ Has anterior and posterior branches ○​ When a driver suddenly hits the brakes while you’re wearing a seatbelt or direct blow to the subxiphoid ​ This can result in a duodenal hematoma and/or pancreatitis as they are close together PEPTIC ULCER PERFORATION ​ Occurs on the anterior wall of the first part of the duodenum OS 206 Topic Name 2 of 10  since this is the portion closest to the stomach and exposed to ​ ~15-20 cm long and weighs about 75 to 100g in adults gastric juices ​ Embryologically, formed by the fusion of a ventral bud and a larger ○​ What can happen if there is an ulcer in the first segment of the dorsal bud duodenum? →​Result of gut rotation ​ It can cause massive hemorrhage as the ulcer can erode the ​ Foregut derivative Gastroduodenal Artery (proximal to the 1st segment) ​ Sensitive organ →​Release enzymes when touched/manipulated during surgery CHOLECYSTECTOMY →​May cause patients to develop pancreatitis ​ An inflamed gallbladder can be adherent to the first part of the ​ Retroperitoneal organ at the level of L1 and L2 duodenum →​Plastered to the abdominal wall ○​ Removal of an inflamed gallbladder (cholecystectomy) may →​Covered by peritoneum lead to accidental perforation of the duodenum ▪​ Except the posterior surface ○​ Injury to the duodenum may lead to the spilling of bowel contents →​Intimately related to the spleen, kidney, aorta, IVC, stomach, into the peritoneal cavity, which may lead to sepsis (acute duodenum abdomen) →​Clinical significance: Accidents crashing the vertebrae, pushingi RIGHT HEMICOLECTOMY AND NEPHRECTOMY them anteriorly may injure the pancreas ▪​ Patient may present with pancreatitis ​ The duodenum is at risk for intraoperative injury during right −​ Enzymes like the lipases will be released and digest the hemicolectomy and right nephrectomy membranes ○​ Removal of the right part of the colon (right hemicolectomy) and right kidney (right nephrectomy) also risks intraoperative A.​ PARTS OF THE PANCREAS injury of the duodenum ​ Duodenum is related to the right upper quadrant Table 1 REGIONS OF THE PANCREAS DUODENAL ATRESIA REGION DESCRIPTION ​ Lies within the C-loop of the duodenum ​ Includes the uncinate process Head ○​ Projection to the left form the lower part of the head behind the superior mesenteric vessels ​ Connects the head to the body ​ Anterior to the beginning of the portal vein ○​ Main vessel of the peripheral vascular system ​ Receives venous blood from the intestines Neck ○​ Resulting from the confluence of splenic and superior mesenteric veins ○​ Pathway of monosaccharides and amino acids ​ Portal vein → liver → hepatic vein → heart ​ Anterior to the splenic artery and vein ○​ Passes obliquely upward to the left going to Body the tail ​ Posterior surface is devoid of peritoneum ​ Extends to the hilum of the spleen anterior to the Tail left kidney Figure 7. Duodenal Atresia showing the Double Bubble Sign ​ Atresia: Undeveloped ​ Failure of most of the duodenum to develop properly or completely →​It is relatively quite common and it happens in about 1 in 2,500 to 1 in 5,000 live births ▪​ Associated with down syndrome ​ Characterized by the classic finding of the double bubble sign →​One at the stomach, another at the proximal duodenum →​Recall: Air appears radiolucent in x-ray ​ Clinical Presentation →​Vomiting →​Feeding intolerance: Cannot tolerate oral food intake Figure 9. Location of the Pancreas. ​ Duodenal Ulcer Figure 8. Duodenal ulcer viewed by duodenoscopy →​Commonly in the first segment of the duodenum →​Bleeding ulcer causes black stools →​Usually caused by chronic non-steroidal anti-inflammatory drugs (NSAIDs) use, e.g., mefenamic acid, ibuprofen II.​ PANCREAS ​ Accessory digestive organ ​ Acts as both an endocrine and exocrine organ →​Exocrine: produces enzymes secreted as zymogens ▪​ Digestive enzymes: −​ Pancreatic amylase: digest carbohydrates −​ Pancreatic lipase: digest triglycerides Figure 10. Omental Bursa: Cross Section including the Pancreas ▪​ 80% of the function of the pancreas ▪​ Predominate by mass *Legend →​Endocrine: produces hormones 1.​ IVC ▪​ Alpha cells: Glucagon 2.​ Omental (epiploic) foramen of WInslow ▪​ Beta cells: Insulin 3.​ Portal Triad ▪​ Delta cells: Somatostatin a.​Common Bile Duct OS 206 Topic Name 3 of 10  ​ Minor/Accessory Pancreatic Duct of Santorini b.​Heptaic Portal Vein ○​ Drains the dorsal anlage c.​Hepatic Artery Proper ○​ Drains the upper part of the head and travels more directly to the 4.​ Omental bursa (lesser sac) duodenum 5.​ Pancreas ○​ Empties into the minor papilla 6.​ Stomach ​ Roughly 2cm to the major papilla 7.​ Spleen ​ Embryology of the pancreas 8.​ Left Kidney ○​ Most common configuration 9.​ Splenic Vein ​ The dorsal bud and ventral bud rotate out and then fuse 10.​Abdominal aorta ​ Common bile duct and major pancreatic duct fuse together and empty to greater duodenal papilla ​ Can cause developmental issues such as Pancreas Divisum Figure 13. Pancreas Embryology C.​ VASCULATURE, LYMPHATICS, AND INNERVATION Arterial Supply ​ Pancreatic head: ○​ Blood supply is shared with the duodenum ○​ Blood supply pathway: ​ Anterior and posterior superior pancreaticoduodenal arteries ​ From the celiac trunk → coimmon hepatic artery → Figure 11. Abdominal Wall and Viscera: Median Section showing Pancreas gastroduodenal artery → superior pancreaticduodenal arteries *Legend ​ Anterior and posterior Inferior pancreaticoduodenal arteries 1.​ Liver ​ From the superior mesenteric artery 2.​ Lesser omentum ○​ Pancreatic body and tail 3.​ Omental bursa (lesser sac) ​ Supplied by the splenic artery branches 4.​ Transverse mesocolon 5.​ Transverse colon Venous Supply 6.​ Small intestine ​ Veins follow the arteries 7.​ Inferior (horizontal or 3rd part of duodenum) ○​ Superior Mesenteric Vein 8.​ N/A ​ Joins the splenic vein to form the portal vein 9.​ Inferior segment of duodenum ○​ Inferior Mesenteric Vein 10.​Pancreas ​ Drains into the splenic vein ○​ Superior and Inferior Pancreaticoduodenal vein ​ Drains to the Superior Mesenteric Vein ○​ Portal vein ​ Removal of the portal vein or its inability to function may cause elevated ammonia levels and lack of nutrients ​ Conversion of ammonia to urea is hindered ​ Portal hypertension​ ​ Caused by high pressure in the liver due to pathologic conditions (eg. cirrhosis, cancer) ​ Reversal of flow in the portal vein → ammonia is not converted into urea ○​ Elevated ammonia levels leads to hepatic encephalopathy ○​ Spleen enlarges as blood flows back to spleen (Splenomegaly) ○​ Blood flows to inferior mesenteric veins then to the rect Figure 12. Regions of the Pancreas (Hemorrhoids) *Legend 1.​ Uncinate process 2.​ Head 3.​ Neck 4.​ Body 5.​ Tail 6.​ *Posterior section: a.​Superior mesenteric artery b.​Superior mesenteric vein c.​Splenic vein *Additional Infomation ​ Superior mesenteric vein will join with the splenic vein to form the portal vein ​ Portal vein ○​ Bring nutrients back to the liver Figure 14. Venous Supply of the Pancreas ○​ Carbohydrates and proteins (absorbed by enterocytes in the duodenum and jejunum), lipids (absorbed in ileum) will Lymphatics go to the liver via the portal vein ​ Not as critical as the duodenum ○​ The liver is supplied by both the hepatic artery and the ​ Found along the arteries portal vein ​ Pancreaticoduodenal nodes ○​ Drains into the celia and superior mesenteric nodes B.​ PANCREATIC DUCTS D.​ VARIANTS ​ Major Pancreatic Duct of Wirsung ○​ Duct of the ventral anlage Pancreas Divisum ○​ Originates in the tail and travels longitudinally through the gland ​ Most common variant of the head ​ Results from failure of fusion of the pancreatic buds ○​ Joins the common bile duct and empties into the Ampulla of ​ Majority of the drainage is in the minor duodenal papilla Vater or Major papilla ​ Most common type of pancreas divisum is the normal pancreas OS 206 Topic Name 4 of 10  with duct of Santorini (B in figure 15) ○​ Produces red blood cells during neonatal period ​ Recurrent Pancreatitis is a possible sign for this variant ○​ Removal of particulate matter and aged or defective blood cells, particularly erythrocytes, from the circulation ​ Provides protection against pathogens in the blood via antibodies ​ Periarteriolar lymphoid sheath (PALS): white pulp region that mount immune response upon encountering pathogens ​ Lymphoid tissues Figure 15. Pancreas Divisum Annular Pancreas ​ Abnormal fusion of the ventral bud to duodenum ○​ May lead to duodenal stenosis (narrowing of duodenum) Figure 17. Surface anatomy of spleen relative to the rest of the abdomen. ​ Clinical Presentation: ​ Not palpable in a normal individual (if palpable, there is ○​ Vomiting splenomegaly) ○​ Polyhydramnios (in utero) ​ Located in the left upper quadrant under the diaphragm ​ Fetus is unable to swallow amniotic fluid due to stenosis ○​ Along the axis of the 9th, 10th, and 11th left posterior ribs ​ Excessive amounts of amniotic fluid ​ The spleen is prone to rupture by the ribs due to it being a Ectopic Pancreatic Tissue thin capsule ​ May be present in the stomach or small intestine ○​ Most common organ injured by blunt trauma (along with liver) ○​ About 3.5% of the population may have this ​ Intraperitoneal ○​ Usually an incidental finding seen during endoscopy ○​ Ruptured spleen causes bleeding from the splenic artery ​ Asymptomatic and no treatment needed ​ Blood will accumulate inside peritoneal cavity ​ Since there is a lot of space in abdomen, ruptured spleen E.​ CLINICAL CORRELATES causes massive blood loss ○​ If too much bleeding occurs, splenic artery must be ligated and ​ Even minor trauma or manipuation to the pancreas may lead to the spleen must be removed (splenectomy) [UPCM 2028 Trans] pancreatitis ​ However, removal of spleen may cause a person to be more ○​ Simply poking the pancreas may lead to a release of enzymes prone to infections caused by encapsulated bacteria; function ○​ The pancreas is avoided during surgeries to avoid complications will be taken over by the liver [UPCM 2028 Trans] ​ Pain of the pancreatic origin may radiate to the back ​ Individuals with spleen removed are typically vaccinated ○​ Due to retriperitonial location, it leads to non-specific pain against encapsulated bacteria (e.g. Neisseria meningitidis) ​ This makes it hard to diagnose pancreatitis and pancreatic cancer A.​ LIGAMENTS ​ Pancreas is difficult to visualize on ultrasonography ​ Spleen articulates with stomach, kidney, and colon ○​ As it lies behind the stomach and within the C-loop of the ○​ Associated with several ligaments duodenum, ultrasound waves cannot pass through the air-filled ​ Splenic hilum: splenic artery and veins stomach due to a lack of medium ○​ CT scan is ideally used to visualize pancreas ​ Surgical obstructive jaundice occurs early in periampullary cancers because of common bile duct obstruction ○​ Enlarged pancreas presses into the bile duct and duodenum ○​ Consider if there is a tumor in the ampulla Whipple Procedure ​ One of the longest procedures ​ Involves removal of the pancreas and duodenum (Pancreaticoduodenectomy) ​ Done usually if you have a tumor in the pancreatic head ○​ Tumor and blood supply is removed ○​ Duodenum is also removed becayse they share the same blood supply via the pancreaticoduodenal artery ​ Procedures ○​ Pancreaticojejunostomy ​ Connect pancreas to jejunum ○​ Hepaticojejunostomy ​ Connect liver to jejunum ○​ Gastrojejunostomy Figure 18. Visceral surface of the spleen. ​ Connect stomach to jejunum Table 2. LIGAMENTS ATTACHED TO THE SPLEEN. LIGAMENT DESCRIPTION ​ Splenic hilum to greater curvature of stomach ​ Contains: Gastrosplenic ○​ Short gastric vessels (supply the spleen and Ligament stomach) ○​ Associated lymphatics ○​ Associated sympathetic nerves ​ Splenic hilum to anterior surface of left kidney Splenorenal ​ Contains: /Lienorenal ○​ Splenic vessels Ligament ○​ Tail of the pancreas ​ Horizontal fold of peritoneum that extends from Figure 16. Visceral surface of the spleen. the splenic flexure of the colon to the Phrenicocolic III.​ SPLEEN diaphragm along the midaxillary line Ligament ​ Forms the upper end of the left paracolic ​ Largest single mass of lymphoid tissue in the body gutter[2027 Trans] ​ Very vascular and reddish purple in color in a living person ○​ Very thin capsule that is easily ruptured ​ Ovoid in shape with a notched anterior border ​ Usually 7-12cm in length, ~150g in weight ○​ In Filipinos, ~100g (about the size of a fist) ​ Functions: ○​ Filters blood ○​ Removal of particulate matter and aged or defective blood cells, particularly erythroyctes, from the circulation OS 206 Topic Name 5 of 10  SPLENOMEGALY ​ Spleen enlargement ​ Caused by conditions associated with hemolysis like hemolytic anemias (e.g. Sickle cell anemia, Spherocytosis) [2026 Trans] ​ Relatively radiopaque because of increased blood flow ○​ Normal spleen will appear highly vascular, homogenous and brighter in contrast CT angiograms due to vascularity Figure 19. Ligaments of the Spleen (yellow highlight). (Enlarged in the Appendix) B.​ VASCULATURE, LYMPHATICS, & INNERVATION ARTERIES ​ Splenic artery Figure 21. X-ray of a patient suffering from splenomegaly ○​ Longest, largest branch of the celiac trunk from the aorta ​ Short gastric arteries RUPTURED SPLEEN (SPLENIC INJURY) ○​ Minor blood supply from the left gastroepiploic or left ​ Spleen appears non-homogenous and patchy in CT angiogram gastroomental artery due to damage vasculature ○​ Supplies spleen and fundus of stomach [UPCM 2026 Trans] ​ Blood extravasates so the spleen is not distinctly identifiable VEINS ​ Splenic vein ○​ Joins the superior mesenteric vein to become the portal vein ○​ Can enlarge in presence of portal hypertension due to the backflow of blood from portal vein ○​ Closely associated with the tail of the pancreas [2026 Trans] ○​ Also receives/drains the IMV Figure 22. Contrast CT angiograms of a normal (L) and a ruptured (R) spleen ​ Spleen remains too be the most commonly affected organ in blunt injuries i.e. blunt trauma caused by being punched, hit by a car, fall, but some textbooks would argue that it is the liver POLYSPLENIA ​ May have 2-6 small spleens that sum up the volume of a normal spleen [2026 Trans] ​ An accessory spleen, which is most commonly found in the hilum or vascular pedicle, is a common congenital anomaly that is found in approximately 10% of the patients ○​ More common in females ○​ Usually diagnosed in late childhood or adulthood ○​ Associated with IVC interruption with azygos/homozygous Figure 20. Spleen Cross Section and in Situ. (Enlarged in Appendix) continuation LYMPHATICS & INNERVATION ​ Lymph nodes in the in the splenic hilum will drain to the pancreaticosplenic lymph nodes, en route to the celiac nodes ​ Celiac plexus, primarily vasomotor[UPCM 2027 Trans] C.​ CLINICAL CORRELATES ​ Splenic injury is common among trauma patients with injuries in the left 9th, 10th, 11th posterior ribs. ​ Situation: When you fall from the 2nd floor and fracture your 9th-11th ribs on the left, your spleen will also rupture. Spleen is like a plastic bag filled with blood. Since it contains the longest and largest branch of the celiac trunk, the splenic artery, a lot of blood will go to the peritoneal cavity, leading to hypovolemic shock ​ Risks of doing splenectomy: ○​ Bacterial infections from encapsulated organisms like ​ Streptococcus pneumoniae ​ Haemophilus influenzae ​ Neisseria meningitidis ○​ Immunization against these encapsulated organisms is a must ​ You can expect portal vein hypertension, which may be due to ○​ Live cirrhosis, Figure 23. Contrast CT angiogram of polysplenia ○​ Liver cancer ○​ Alcoholic liver disease causing congestion of the spleen AUTOSPLENECTOMY ​ Another reason may be due to recurrent hemolysis or Hemolytic ​ Can occur in cases of sickle-cell disease where the misshapen anemia which is more commonly present in patients with sickle cell cells block blood flow to the spleen, causing scarring, infarction, anemia, G6PD deficiency, pyruvate kinase deficiency, and and eventual atrophy of the organ. Hereditary xerocytosis ​ Autosplenectomy can occur in cases of sickle-cell disease where the misshapen cells block blood flow to the spleen, causing scarring, infarction, and eventual atrophy of the organ OS 206 Topic Name 6 of 10  IV.​ VASCULATURE SUMMARY fundus of the stomach ​ → Common hepatic artery ​ Right gastroepiploic artery - goes to the lesser curvature ​ Hepatic artery proper - goes to the liver ​ Gastroduodenal arteries gives off: ○​ Superior pancreaticoduodenal artery ○​ Right gastroepiploic artery (goes to the greater curvature of the stomach) ○​ Superior Mesenteric Artery ​ → Inferior pancreaticoduodenal artery Table 3. SUMMARY OF THE BLOOD SUPPLY OF THE GI ORGANS [2026 Trans] ORGANS BLOOD SUPPLY ​ Celiac Trunk → Common Hepatic Artery → Gastroduodenal Artery → Superior Pancreas & Pancreaticoduodenal Artery Duodenum ​ Aorta → Superior Mesenteric Artery → Inferior Pancreaticoduodenal Artery ​ Celiac Trunk → Splenic Artery → Short Spleen Gastric Arteries From the Celiac Trunk ​ → Left Gastric Artery ​ → Common Hepatic Artery ○​ Right Gastric Artery ○​ Gastroduodenal Artery → Right Gastro-omental / Gastroepiploic Stomach Artery Figure 24. Vasculature of the GI system. (Enlarged in Appendix) Lesser Curvature: Right & Left Gastric Arteries ​ Abdominal aorta branches into: Greater Curvature: Gastro-omental / ○​ Celiac Trunk Gastroepiploic Artery → Left gastric artery - supplies the lesser curvature of the stomach ​ Celiac Trunk → Common Hepatic Artery → → Splenic artery - supplies the spleen Proper Hepatic Artery (20%) Liver ​ Left gastroepiploic artery / Gastro-omental artery - ​ Superior Mesenteric Vein + Splenic Vein → goes to the greater curvature Hepatic Portal Vein (80%) ​ Short gastric arteries - goes to the spleen and OS 206 Topic Name 7 of 10  APPENDIX Figure A1. Segments of the Duodenum (yellow highlight) OS 206 Topic Name 8 of 10  Figure A2. Ligaments of the Spleen (yellow highlight) Figure A3. Spleen Cross Section and in Situ OS 206 Topic Name 9 of 10  Figure A4. Vasculature of the GI system OS 206 Topic Name 10 of 10