Pancreas Flashcards
In a study by Veytsman 2022 in Vet Surg, what was the median survival time for cats undergoing surgery for insulinoma? What were five identified negative prognostic factors identified?
MST of 863 days.
Five negative prognostic factors identified were age, decreased time to euglycemia, low serum glucose concentrations, metastasis, extent of tumour invasion.
Majority of lesions were in the left limb.
In a study by Case 2024 in Vet Surg describing laparoscopic partial pancreatectomy, what was the grade 1 and grade 2 complication rates? What was the long term effect on exocrine function?
11% grade 1 and 2 complications (mild hemorrhage intra-op [grade 1] and sterile peritonitis [grade 2} post-op).
Excocrine function adequate. Hemoglobin A1C and PLI unchanged. TLI decreased by 37%.
In a study by Collgros 2023 in JAVMA, what was the median survival time of patients undergoing pancreatectomy for insulinoma when a positive increase in blood glucose was used to guide completeness of surgical resection?
762 days
In a study by Coss 2021 in JSAP, what were the CT angiographic features of insulinoma?
Hyperattenuating in the arterial phase, occasional deformation of the pancreatic limb. CT findings correlated well to surgical localization.
In a study by Ryan 2021 in JSAP, what were the 3 most common presenting clinical signs in dogs with insulinoma? What were the 2 most common neurologic findings? What were the MST with and without surgery?
Weakness, seizures and changes in consciousness/behaviour were the most common clinical signs.
Neurologic abnormalities were typically located to the forebrain and obtundation was common.
Survival with surgery was 20 months, without surgery it was 8 months. Presence of metastasis and whether surgery was performed were only 2 factors associated with prognosis.
In a study by Wolfe 2022 in JSAP, what was the perioperative mortality rate for dogs and cats undergoing pancreatic surgery?
20% in cats, 10% in dogs.
Partial pancreatectomy was predominantly performed in dogs, pancreatic biopsy in cats.
In a study by Skarbek 2023 in VRU, what arterial phase (early, mid, or late) was best for visualization of pancreatic insulinomas and metastatic lesions?
The late arterial phase showed the highest enhancement scores.
In a study by Petrelli 2023 in JVIM, was serum insulin concentration in dogs with insulinoma related to presence of metastatic disease or survival time?
No - concentrations were not different based on stage of disease or ultimate survival.
What percentage of the pancreas is formed by the exocrine portion?
98% of total mass
What pancreatic cells are responsible for releasing digestive enzymes?
Acinar cells
What are the four cell types that make up the endocrine function of the pancreas (within the Islets of Langerhans)?
Alpha cells: glucagon
Beta cells: insulin
Delta cells: somatostatin
PP or F cells: pancreatic polypeptide
Describe the blood supply to the pancreas.
What percentage of cats have a single pancreatic duct?
80%
Is the pancreatic or accessory pancreatic duct the major duct in dogs?
Accessory pancreatic duct, enters at the minor duodenal papilla.
In some dogs the pancreatic duct is absent.
What are the functions of insulin and glucagon?
Insulin: decreases blood concentrations of glucose, fatty acids and amino acids and promotes intracellular conversion of these compounds into glycogen, triglycerides, and protein.
Glucagon: mobilizes energy stores by increasing glycogenolysis, gluconeogenesis, and lipolysis.
What are the function of exocrine pancreatic secretions in the duodenum?
Neutralize gastric acid, inhibit bacterial proliferation, aid in digestion.
What are the main components of pancreatic exocrine section?
Proteases, lipases, amylases, bicarbonate, potassium, sodium, chloride, water, intrinsic factor.
What is the role of intrinsic factor released from the exocrine pancreas?
Aids in absorption of vitamin B in the distal ileum.
What are the three mechanisms which prevent autodigestion of the pancreas?
- Storage of enzymes as inactivated zymogens. Activation only occurs when they reach the duodenum (see image).
- Segregated storage of zymogens within granules within the pancreas.
- Synthesis of pancreatic secretory trypsin inhibitor by the acinar cells.
What stimulates release of pancreatic exocrine secretions?
- Smell or presence of food via vagal nerve stimulation.
- Movement of food into the duodenum causing release of secretin and cholecystokinin. Stimulate release of bicarbonate rich fluid and secretion of digestive enzymes.
What occurs following injury to the pancreas?
Inappropriate protease activation that can cause a significant inflammatory response +/- hypovolemia, MODS and SIRS. Necrotizing pancreatitis can result in severe cases. Fibrosis may also occur when chronic.
Why should alpha-2 agonists be avoided in patients with pancreatic disease?
Typically cause hypoinsulinemia and hyperglycemia, but effects on the diseased pancreas can be unpredictable.
What region of the pancreas is preferred for pancreatic biopsy?
Distal right limb of the pancreas.
What are some described techniques of pancreatic biopsy?
Open: Tru-cut, clamshell or punch biopsy forceps, wedge, suture fracture, blunt dissection and ligation.
Laparoscopic, or lap-assisted: cup, clamshell or punch biopsy forceps, pretied loop ligature, bipolar vessel sealing device, harmonic scalpel, hemostatic clips placed in a v-shape.
What are some potential complications of pancreatic biopsy?
Pancreatitis +/- septic peritonitis, vomiting, cranial abdominal pain, nausea, anorexia, lethargy.
How much of the pancreas can be resected without impairment of the endocrine or exocrine function?
75-90% (so long as remaining duct intact).
Has substantial regenerative capacity.
What are some clinical indications of total pancreatectomy in dogs?
Rarely indicated. Patients will require ongoing post-operative management for diabetes mellitus and exocrine pancreatic insufficiency.
Potential indications include acute trauma, intractable pancreatitis, and severe chronic fibrosis.
Care should be taken to preserve what structures during total pancreatectomy?
Vascular supply to the duodenum (cranial and caudal pancreaticoduodenal arteries, gastroduodenal artery, splenic artery).
If vascular supply cannot be preserved concurrent pancreaticoduodenectomy and cholecystoenterostomy can be performed.
What is the most common complication following pancreatic surgery?
Pancreatitis.
What is the mechanism of action of maropitant?
Blockage of centrally and peripherally mediated emesis through blockage of neurokinin-1 receptors and substance P production.
What is the difference between acute and chronic pancreatitis?
Acute: sudden onset and reversible.
Chronic: subclinical inflammation accompanied by irreversible fibrosis.
What are some proposed risk factors for development of pancreatitis in dogs?
Dietary indiscretion, obesity, hyperlipidemia, hypercalcemia, corticosteroid administration, ischemia, administration of specific drugs, genetic predisposition for hyperlipoproteinemia, pancreatic duct obstruction, and pancreatic trauma.
Is vomiting a common sign of pancreatitis in both dogs and cats?
Common in dogs (90%), less common in cats (39%).
What are common laboratory findings in dogs with pancreatitis?
CBC: leukocytosis, increased PCV.
Biochem: pre-renal azotemia, hepatic enzymopathy, hyperbilirubinemia, hypercholesterolemia, hypertriglyceridemia, hyperglycemia (necrotizing pancreatitis due to elevated glucagon from increased catecholamines), diabetes mellitus if permanent damage occurs.
Amylase and lipase: non-specific indicators of pancreatic dysfunction. Undergo renal excretion so can be elevated in instances of renal dysfunction.
TLI: sensitive and specific for diagnosis of exocrine pancreatic insufficiency, but not pancreatitis.
cPLI: most sensitive and specific test available for diagnosis of canine pancreatitis. False positives in 40% of dogs.
What are indications for surgical intervention in patients with pancreatitis?
Evidence of infection, biliary obstruction, pancreatic abscess, confirmation of disease via biopsy, lack of response to aggressive medical management.
In cases of permanent biliary obstruction due to pancreatic fibrosis cholecystoduodenostomy may be required.
Are pancreatic abscesses in dogs and cats more commonly sterile or infected?
Sterile.
In one study 15% growth from the pancreatic tissue, 58% growth from the abdominal cavity. Multiple swabs of the abdominal cavity recommended.
What surgical techniques have been described for the treatment of pancreatic abscessation?
Debridement, partial pancreatectomy, pancreatic biopsy, cholecystoenterostomy, provision of drainage, omentalization, duodenal resection and anastomosis.
What are the survival rates for surgical treatment of pancreatic abscess?
14-55%
What is the proposed etiology of pancreatic pseudocyst formation?
Potential rupture of a pancreatic duct during pancreatitis.
How is pancreatic pseudocyst diagnosed?
Fluid filled mass on ultrasound, aspirated fluid has an increase in pancreatic enzyme concentrations relative to serum.
In which part of the pancreas are pancreatic pseudocysts most frequently diagnosed?
Left limb.
What are treatment options for pancreatic pseudocyst?
Benign neglect (if no clinical signs and cysts are small, <4cm), ultrasound guided percutaneous aspiration, surgical excision, surgical drainage (cystoduodenostomy, cystojejunostomy, cystogastrostomy, omentalization).
What is the success rate for treatment of pancreatic pseudocysts?
75%
What are the most common tumours of the exocrine pancreas in dogs and cats?
Carcinomas (either arising from the acinar or ductal cells).
How is pancreatic carcinoma diagnosed?
Difficult to differentiate from pancreatitis based on imaging and biochemical findings (serum lipase >25 x normal suggestive of carcinoma).
Open surgical biopsy often required (although diagnosis sometimes possible from FNA).
What surgical treatment is recommended for pancreatic carcinoma?
Complete pancreatectomy is described but generally not considered due to high rate of metastasis and extremely poor prognosis.
What percentage of dogs with insulinoma have metastatic disease at the time of diagnosis?
50% (regional lymph nodes and liver most commonly)
Which dogs are most commonly affected by insulinoma?
Medium to large breed dogs
What clinical signs are common with insulinoma?
Seizures, weakness, collapse, ataxia, mental dullness.
Peripheral polyneuropathy can result from demyelination secondary to prolonged chronic hypoglycemia.
What are some common laboratory findings in dogs with insulinoma?
Hypoglycemia with high insulin levels. Decreased fructosamine may also be observed.
What imaging techniques might be used for detection of insulinoma?
Ultrasound (56% sensitivity), CT (increased sensitivity). Late arterial phase shown to have best chance of detecting insulinoma on CT angiography.
How can dogs with insulinoma be stabilized prior to surgery?
Frequent feeding of small meals, glucocorticoid therapy, dextrose CRI (may not resolve hypoglycemia in some cases due to stimulation of insulin secretion), glucagon CRI useful for intractable hypoglycemia.
In what percentage of dogs is a solitary 0.5-4cm nodule evident during surgery for insulinoma?
80%
What are methods of insulinoma identification during surgical exploration and partial pancreatectomy?
Visualization, palpation, methylene blue administration (3 mg/kg IV; can cause Heinz body anemia), collection of multiple biopsies to identify location for subsequent surgery.
What are some treatment options for the management of persistent hypoglycemia following surgical resection of insulinoma?
- Streptozocin: selectively destroys beta cells. Can cause gastrointestinal toxicity (63%) and diabetes mellitus (42%).
- Glucocorticoids.
- Diazoxide: inhibits insulin release, stimulates glycogenolysis and gluconeogenesis, inhibits use of glucose.
- Octreotide: somatostatin anologue that inhibits insulin synthesis (actions are short lived).
What is the MST for dogs undergoing surgical resection of insulinoma?
18-months without metastatic disease, 7-9 months with metastatic disease.
What are some prognostic factors for survival in canine insulinoma?
Tumour size (>2cm), disease stage (metastasis to liver or regional lymph nodes), Ki67 proliferation index (>2.5%).
What is a gastrinoma?
Pancreatic islet cell tumours in which somatostatin secreting delta cells undergo malignant transformation to cells that secrete excessive amounts of gastrin. Results in esophageal and gastroduodenal ulceration.
What is Zollinger-Ellison syndrome?
Combination of a non-beta cell tumour in the pancreas, hypergastrinemia, and gastrointestinal ulceration.
What is the metastatic rate of patients with gastrinoma at the time of diagnosis?
70%.
GI ulceration identified in 80%.
How is gastrinoma typically identified?
Difficult to visualize on imaging.
Increased fasting gastrin in conjunction with gastric hyperacidity (pH < 3) is highly suggestive.
What medical management options are available for gastrinoma?
Gastric acid inhibitors (pantoprazole), gastroprotectants (sulcralfate, misoprostal), suppression of gastric acid secretion (octreotide).
What is the prognosis for patients with gastrinoma?
MST 1 week to 18 months.
What is the primary clinical sign in dogs with glucagonoma?
Hepatocutaneous syndrome (or superficial necrolytic dermatitis).
Hyperglycemia and diabetes mellitus resistant to insulin may also be observed.
What is the prognosis for dogs with glucagonoma?
Typically poor due to a high rate of metastatic disease. Short term remission of skin lesions has been reported using octreotide.
