Small Animal Sx - Pancreas

drraythe's version from 2015-11-24 19:58

intro/ anatomy

Question Answer
the three main parts of the pancreas are?Body, Left limb, right limb
where is the body of the panc?lives in flexure of gastric pylorus and the prox duodeinum
where does the left limb of the panc live?deep leaf of greater omentum (harder to access surgically)
where does the right limb of the panc live?extends along prox duodeinum within the meso duodeinum
major blood supply of left limb of panc?branches of celiac artery (which comes off of the aorta.) celiac will later branch into SPLENIC and HEPATIC artery. This means there are branches of splenic artery and heaptic artery which perfuse the LL. The hepatic artery terminates in the Cr. pancreatico-duodeinal artery. (so, left limb is main branches of the celiac artery).
major blood supply of right limb of panc?comes from a branch of the Cr. mesenteric artery-- the Caudal pancreatico-duodeinal artery* this is the main blood supply of the right lobe.
*so all the blood supplies terminate to the cr and ca pancreatico-duodeinal arteries within the panc. This implies these vessels are supplying the panc AND the duodeinum. what surgical implications are there for this?if you aren't careful where you are ligating if you are removing a limb of the panc, you can compromise blood supply to the duodeinum! So when removing right limb of panc you need to be super careful to preserve duodeinal branches of that vessel
what is the excreatory duct system like for the panc2 ducts that drain the panc- (1) pancreatic duct. Empties into dudeinum via major duodeinal papilla (most cr/orad in duo.). then downstream is the minor duodeinal papilla which is being drained from the accessory panc duct. However there will be variation *nothing carved in stone
which panc duct does the CAT usually only have (their primary duct) what papilla does it drain to?only the pancreatic duct that drains into the major duodeinal papilla (this is their primary duct)
what is the DOGS primary pancreatic duct? what papilla does it drain into?theirs is the ACCESSORY duct draining into the MINOR duodenal papilla
which would be a bigger problem- having a tumor near the major duodenal papilla (pancreatic duct) or near the minor duodeinal papilla (accessory duct)? Why?THE MAJOR one because the common bile duct also drains into duodeinum from there
3 major hormones the panc makes?insulin, gastrin, glucagon
what is the endocrine function of the panc?Hormones produced by islet cells---> insulin (β cells), glucagon (α cells), somatostatin (δ cells), gastrin (non-β cells) (dont have to worry about type of islet cells)
what is the exocrine function of the panc?Digestive enzymes

Sx approach/ bx

Question Answer
which quadrant of the body does the panc lie in?Right cranial (so look for pain here)
approach/incision to panc?Ventral midline incision: xyphoid --> caudal to umbilicus
how do you examine panc?Examine pancreas by visualization & gentle palpation (many of the tumors very small will need to feel); keep tissues moist!
how do you visualize the left lobe of the panc?Retract greater omentum cranially & bluntly dissect through deep leaf
how do you visualize the body of the panc?look for it at bend formed between pylorus & duodenum
how do you visualize the right lobe of the panc? (dorsal and ventral sides)DORSAL: retract duodenum ventrally & toward midline. VENTRAL: retract duodenum laterally
if you suspect neoplasia of the panc, what OTHER places should you check (most common places for metastasis)evaluate/ biopsy regional lymph nodes, liver (some to omentum itself)
3 possible methods for Partial pancreatectomy?(1) Blunt dissection & ligation (2) Suture fracture technique (3) Vessel sealing technique (Ligasure®)
Potential indications for partial pancreatectomy? (4)Mass, focal trauma, abscess, pseudocyst
how do you perform Blunt dissection & ligation for a Partial pancreatectomy?(nice bc can isolate whatever part of panc you want). Use some small hemostatic forceps (like a halstead) or cotton tipped applicators to dissect between the mini lobes (lobules) to isolate part of panc you want to remove. se you come across the BVs or ducts, you ligate those. then transect. *be sure to DOUBLE LIGATE so there is NO LEAKAGE
how do you perform suture fracture technique for Partial pancreatectomy? *what is the technique indicated for?*Indicated for FOCAL lesions on the MARGIN! Just use suture to cinch down on a portion of the panc and remove it. So make 2 incisions into the omentum (or if right limb, the mesoduodeinum) (red in pic) then a 3rd incision (in meso/omentum) along the edge of the portion to be removed to free up can from omentum. Then wrap suture around affected portion onf pan, and tighten ligature around panc and it'll occlude any vessels/ducts. Once ligature secured, sharply dissect that portion of panc. and remove. (leave lig on)
how do you perform Vessel sealing technique (Ligasure®) for a Partial pancreatectomy?it's a stapling technique with a ligasure.
If you need to remove more than just a portion, say, Resection of the right limb of the panc, what is important that you do?PRESERVE THE DUODENAL Branches OF the CA pancreatioco-duodeinal artery! So dissect panc away from duodenum, and then you can see the Ca.PD artery....then want to only ligate panc branches.
If there is diffuse dz of panc, where is the best place to take a bx from? why?the right limb- bc easy to get to, further from body so further from ducts...and at ca aspect of R lobe you dont need to worry about shared blood supply.
who is laproscopic bx used more commonly in?cats
pros and cons of laproscopic bx?PROS: only need 2-3 holes not a large ventral midline incision, easy to access the edge of R lobe of panc. CONS: can't FEEL anything/palpate. (and can't see as much)
how much of the panc can you remove without causing probs with insufficiencies?Up to 80% of pancreas can be removed without causing endo- or exocrine insufficiency provided blood supply and ducts to the remaining tissue are preserved
If you remove more than _________% of the panc (too much), you can get what problems?>80%, you can get exocrine or endocrine pancreatic insufficiency.
recc suture material for ligating ducts? exception?Recc is *non-absorbable suture material like *polypropylene or nylon. * Exception= infection/septic conditions of the pancreas --> use absorbable monofilament (ie. PDS, Monocryl) Monofilament to reduce chances of wicking and bact harboring in the crevices of the braiding, and then ABSORBABLE bc long it hangs around, better chance for it to become a home for bact.
how can you help avoid pancreatitis as a post-op complication?maintain good perfusion during surgery, gentle tissue handling
what are 2 ways Exocrine pancreatic insufficiency (EPI)/Endocrine pancreatic insufficiency can become post-op complications?(1) If >80% of pancreas removed, get Exocrine pancreatic insufficiency (EPI) and Endocrine pancreatic insufficiency (diabetes mellitus) (2) EPI if pancreatic drainage obstructed

Surgical Conditions of the Pancreas

Question Answer
what are the 3 possible neoplasias of the panc?(1) Adenocarcinoma of the exocrine pancreas (2) Adenocarcinoma of the β cells of the pancreatic islets (insulinoma) (3) Adenocarcinoma of the non-β cells of the pancreatic islets (gastrinoma)
Adenocarcinoma of the exocrine pancreas prolly presents as..GI signs
Adenocarcinoma of the β cells of the pancreatic islets (insulinoma) prolly presents as..HYPOGLYCEMIA!!!! so light headed, not well, mm fasiculations, seizures
denocarcinoma of the non-β cells of the pancreatic islets (gastrinoma) prolly presents as..ULCERS!! bc gastrin stim release of HCl
4 common sx conditions of panc?Pancreatic neoplasia, Pancreatic abscess, Pancreatic pseudocyst, Pancreatic trauma
how common are panc tumors?uncommon
what is the most common type of neoplasia of the panc?Adenocarcinoma of the exocrine pancreas is the most common neoplasia of the pancreas (but vague signs so insulinoma is more often dx pre-mortem)
Gastrinomas are associated with WHAT syndrome? how is this charaterized?Zollinger~Ellison syndrome--- diff parts of the body can create gastrin. panc is one of them. When the tumor is in the panc and causes the gastric ulceration, that is what the syndrome is (panc-specific syndrome)
Which diagnostic tool would be most helpful in identifying surgical pancreatic disease?abd U/S bc panc tumors often small so rads wont pick them up
common signalment of Exocrine Pancreatic Adenocarcinoma?Older animals, Boxers, Airedale Terriers!
C/S of exocrine pancreatic adenocarcinoma?VAGUE!! Often non-specific, Weight loss, anorexia, Depression, Vomiting, Jaundice
In cases of exocrine pancreatic adenocarcinoma, icterus is typically caused by....(why?).Bile duct obstruction. bc tumor likes to live near ducts (main panc duct by major papillae) like to manifest at body of panc so can cause mechanical bile duct obstruction ((bc bile duct also goes in around the same area of the major duodenal papilla)
how do dx exocrine pancreatic adenocarcinoma?Cytology of peritoneal lavage fluid may be diagnostic - tumors exfoliate readily. Could also use Radiology/ultrasonography
exocrine pancreatic adenocarcinoma like to metastasize where?liver :(
prog of exocrine pancreatic adenocarcinoma? why? MST (mean survival time?)Extremely poor prog, bc Early widespread metastasis common. MST <3 months
tx for exocrine pancreatic adenocarcinoma?Partial or total pancreatectomy (total doesn't really exist in vet med) (After total pancreatectomy, must perform Bilroth II procedure and also replace exocrine and endocrine pancreatic hormones for life of patient)
most common signalment of insulinoma? (age? breeds?) Mean age 8.7 years (range 4-13 years) ie middle aged dogs, Medium to large breed dogs. Irish setters, German shepherds, Boxers, miniature poodles at risk (no sex predilection)
charateristic of clinical signs of insulinoma? duration before dx (and why?)INTERMITTENT (more continuous as dz progresses). Duration of clinical signs prior to diagnosis... .mean= 3.2 months, range= 1- 24 months. This is because they often present for seizures!! so vets think it is epilepsy. (Reports of signs existing as long as 3 years before diagnosis!)
what are the presenting clinical signs of insulinoma? how are they related?Signs are related to hypoglycemia (2° to hyperinsulinism), which include Muscle fasciculation, weakness, rear limb ataxia, collapse, Mental dullness, disorientation, seizures (29% of dogs with insulinoma were treated with anticonvulsant drugs prior to diagnosis!!!)
what is whipples triad? (3)**PATHOGNOMONIC to insulinomas (1) Neurological disturbance (associated with hypoglycemia) (2) Hypoglycemia --> fasting plasma glucose < 40-50 mg/dL (3) Resolution of neurological disturbance following feeding or parenteral administration of glucose
quick n easy way to test if it's insulinoma clinical signs?FEED them---> that fixes the hypoglycemia and they improve temporarily.
blood glucose levels characteristic of insulinoma?< 40-50 mg/dL
ways to dx insulinoma?(1) Documentation of hypoglycemia (highly diagnostic, > 98% of patients) (2) Demonstration of hyperinsulinism (diagnostic, > 66%) (3) Diagnostic imaging (rarely diagnostic) (4) Ratio of insulin to glucose, provocative tests * no longer used (5) Exploratory celiotomy + histopathology
how do you medically manage insulinoma pts? WHEN do you do medical management?Reserved for cases with metastatic disease--> Frequent feedings of high protein & complex carbohydrates, low sugar. Oral hyperglycemic agents (prednisone, diazoxide, streptozocin)
how do you surgically manage insulinoma?--> PREOPERATIVELY? (3)(1) Multiple (3 to 6 times per day) feeding with high protein, complex carbohydrate diet (2) Begin 5% dextrose IV 12-24 hrs before surgery (3) Withhold food ~8 hrs prior to surgery
how do you surgically manage insulinoma?--> INTRAOPERATIVELY? (GLUCOSE MANAGEMENT)Hypoglycemia may be induced by tumor manipulation - monitor blood glucose! Stress gluconeogenesis induced by anesthesia and surgery counteracts increased insulin release in most cases. 10% dextrose IV given at normal rate during surgery is usually adequate
what major things should you be doing during the procedure? (3)(1) Thorough examination of pancreas, regional lymph nodes, liver and omentum (visual + palpation) (2) Surgical removal of tumor(s) in pancreas and elsewhere, if possible (3) Biopsy of lymph nodes and liver if no visible/palpable secondary tumors
insulinoma--> primary tumors usually feel like? what are some variations you can see? Primary tumors are firm and often small. More than one tumor may be present
where are primary tumors usually located?left lobe > right lobe > body > mult
what can you do to help with hemostasis during the procedure?Ophthalmic cautery may be used for hemostasis, or use bipolar mode
what can you use as a tool to delineate insulinomas?Methylene blue, injected IV, can be used to delineate insulinomas--> specifically stains neoplastic pancreatic islet tissue! Give 3 mg/kg BW – avoid excessive dosages--> bc can cause hemolytic anemia!!!
how do you surgically manage insulinoma?--> POSTOPERATIVELY?NPO for 24 hours (5% dextrose IV maintenance fluids)!!! Post-operative pancreatitis is not common, and there MAY OR MAY NOT BE: Persistant hypoglycemia(might be metastasis you didnt get), Transient diabetes mellitus (bc negative feedback--> healthy cells were dormant) (25%), Peripheral polyneuropathy (chronic hypoglycemia can cause axonal degeneration)
mean survival time... if No macroscopic metastasis at time of Sx?~12 months
mean survival time... if Macroscopic metastasis at time of Sx?~3+ months