Unit 2: 1 - Spleen, Pancreas Flashcards
What is the most common surgery involving the spleen?
splenectomy
What are 3 indications for a splenectomy?
- Diffuse splenomegaly
- Focal splenomegaly
- Trauma
- Immune-mediated disease
What are the 4 components to a splenectomy?
- Ligation and division at 4 or 5 sites
- Need to enter omental bursa
- Need to locate vessels to the greater omentum
- Preserve pancreatic blood flow
What 3 vessels need to be located when entering the omental bursa during a splenectomy?
- Splenic artery distal to last branch to pancreas
- Left gastroepiploic artery
- Short gastric arteries
What types of splenic masses can occur?
Hematoma, nodular hyperplasia, hemangiosarcoma
What clinical signs are associated with a splenic mass?
Abd distenstion, weight loss, inappetance, lethargy, weakness, fainting, shock
How can we get a definitive Dx for a splenic mass?
Histopathology
What diagnostics can be done as part of a pre-op workup for a splenic mass?
- CBC, chem, UA
- Chest rads
- Abd rads, ultrasound
- Abdominocentesis
- Coag profile
- Echo - R auricular mass
What % of acute non-traumatic hemoabdomen with splenic mass is made up of malignant disease?
63-80%
What % of malignant hemoabdomen cases were due to HSA?
70-88%
How many splenic mass cases are malignant without hemoabdomen?
50%
What is the % of small dogs vs. large dogs that have splenic hemorrhage with a splenic mass?
43% small dogs
62% large dogs
What is the % of benign vs. malignant splenic masses in dogs?
Benign = 15%
Malignant = 85%
What dog breeds is HSA more common/likely in?
large breeds
What is the most common splenic tumor?
hemangiosarcoma
Why is HSA aggressive when discovered?
At the time of diagnosis it is likely to already have a high rate of metastasis
HSA makes up to 25% of _____ masses.
R atrial
What 3 biopsies should always be obtained when HSA is suspected (or any splenic mass)?
- Hepatic
- +/- LN
- Other organs if abnormal appearance
How should the spleen be submitted to the lab when a splenic mass is suspected?
Entire spleen or multiple sections
T/F: It is easy to differentiate grossly between hemangiosarcoma and hemangioma
False
What are common areas of metastasis for HSA?
- Lungs
- Liver (portal blood flow)
- Peritoneum (cells from hemoabdomen)
- Heart (R auricle)
- CNS (most common metastatic tumor to the CNS)
What is a stage 1 splenic tumor?
Tumor localized to spleen
What is a stage 2 splenic tumor?
Ruptured tumor
What is a stage 3 splenic tumor?
Tumor with metastasis
What is the survival time for an animal that is diagnosed with a stage 3 splenic tumor?
3.5 month survival (surgery + chemo)
What is the most common diagnosis (stage) for a splenic tumor and what is the prevalence?
Stage 3 - 95% of dogs have metastasis at the time of diagnosis (macro or micro metastatic disease)
What are 4 complications that can occur from a splenic mass?
- High incidence of cardiac arrythmias (vent. tachyarrhythmias)
- Hemorrhage
- DIC
- Increased risk of GDV?
What is the general prognosis for HSA?
Poor long term prognosis (95% have mets)
What is the prognosis for HSA with surgery alone?
1-3 months MST
(<31% @ 2 months, <7% @ 12 months)
What is the prognosis for HSA with surgery + chemo?
3-6 months MST
What is the prognosis for splenic masses that are benign, or for splenic torsion?
Good long term prognosis
What are the 6 anatomical components of the pancreas that we must be aware of for surgery?
- L limb
- R limb
- Central body
- Accessory pancreatic duct (minor duodenal papilla)
- Pancreatic duct (major duodenal papilla)
- Blood supply
What is the endocrine function of the pancreas?
- Insulin (beta cells)
- Glucagon (alpha cells)
- Somatostatin (delta cells)
What cells make insulin?
beta
What cells make glucagon?
alpha
What cells make somatostatin?
delta
What is the exocrine function of the pancreas?
Secretion of enzymes to digest CHO, fat, proteins
What vessels are associated with the left limb of the pancreas?
Splenic artery
What vessels are associated with the right limb of the pancreas?
- Hepatic artery
- Cranial pancreatico-duodenal artery
- Caudal pacreatico-duodenal artery
Where does the hepatic artery branch from?
Celiac artery
Where does the cranial pancreatico-duodenal artery branch from?
Celiac artery
Where does the caudal pancreatico-duodenal artery branch from?
Cranial mesenteric artery
Where does the splenic artery branch from?
Celiac artery
What are the pancreatic ducts present in the dog and where do they enter the duodenum?
Pancreatic duct (@ major duodenal papilla) and accessory pancreatic duct (@ minor duodenal papilla)
What % of dogs have one duct from each pancreatic limb?
68%
What is the main pancreatic duct in dogs and where does it terminate? What is it AKA?
Accessory pancreatic duct - terminates @ minor duodenal papilla
AKA Duct of Santorini
What is the secondary pancreatic duct in dogs and where does it terminate? What is it AKA?
Pancreatic duct - terminates @ major duodenal papilla
AKA Duct of Wirsung
What % of cats have a single pancreatic duct?
80%
What pancreatic duct is the main one in cats?
Pancreatic duct (duct of Wirsung)
The pancreatic duct of cats terminates at the _____ duodenal papilla with the _____.
major, common bile duct
What does it mean when we say that cats are prone to “triaditis”?
Pancreatitis + IBD + cholangiohepatitis
What are exocrine pancreatic cells called?
acinar cells
What are the 4 cell types of the endocrine pancreas?
Pancreatic polypeptide cells, alpha cells, beta cells, delta cells
What pancreatic “structure” contains the cells in the endocrine pancreas?
Islet of Langerhans
What is insulin release primarily triggered by?
Increased in blood glucose
What does insulin release stimulate?
Anabolic reactions involving CHO in the liver, muscle, and adipose tissue
What are the short term counter-regulatory hormones?
Glucagon and epinephrine
What does glucagon do?
Stimulates hepatic glucose production by increasing glycogenolysis, gluconeogenesis, and lipolysis;
Primarily acts to increase BG levels
What does epinephrine do?
Increases hepatic glucose production and promotes hyperglycemia.
Epinephrine _____ insulin secretion.
inhibits
Epinephrine _____ liver glycogenolysis.
stimulates
Epinephrine _____ glucagon secretion.
stimulates
What are the long term counter-regulatory hormones?
Glucocorticoids (cortisol) and growth hormone
What do glucocorticoids (cortisol) do?
Promotes increased hepatic glucose production, impairs glucose uptake
What does growth hormone do?
Stimulates ketogenesis, impairs glucose uptake
What is the extent of a pancreatic surgical procedure?
Can do partial pancreatectomy at the limbs;
It is difficult or impossible to resect the central body (focal lesions can be excised)
What are the 3 indications for pancreatic surgery?
- Neoplasia
- Non-neoplastic disease
- Pancreatic biopsy
What are the 3 common types of pancreatic neoplasia?
- Insulinoma
- Gastrinoma
- Adenocarcinoma
What are the 2 types of non-neoplastic disease that can be an indication for surgery?
Pancreatic abscess, pancreatic pseudocysts
Pancreatic abscesses/pseudocysts are usually a consequence of _____.
pancreatitis
T/F: Pancreatic abscesses/pseudocysts are almost always sterile
True
What are 3 steps to surgically treat pancreatic abscesses/pseudocysts?
- Drainage
- Debridement
- Omentalization
How is pancreatitis managed?
Aggressively managed medically
Pancreatitis may lead to _____ obstruction.
biliary tract
How can biliary obstruction due to pancreatitis be repaired?
Biliary diversion or stent placement
What may have to be placed in a patient with pancreatitis?
- Jejunostomy tube - bypassing duodenal papilla
- Esophagostomy tube
What is a consequence/disadvantage of taking a pancreatic biopsy?
Can cause pancreatitis
What are the more common clinical signs associated with insulinomas?
Neurological signs
What is an insulinoma and what does it cause?
Insulin-secreting mass; –> hypoglycemia due to excess insulin
What are 3 specific clinical signs for an insulinoma?
Seizures, general weakness, dull mentation
What are the 3 requirements for diagnosis of an insulinoma and what is it called?
Whipple’s Triad:
- Hypoglycemia <70 mg/dL
- CS consistent with low BG
- Resolved CS after admin of dextrose/glucose
What diagnostic tests can be performed to look for an insulinoma?
CBC, chem, UA, chest/abd rads, insulin levels, ultrasound, triple phase contrast CT
What diagnostic test has the most sensitivity when looking for an insulinoma?
triple phase contrast CT
Why is fructosamine used as a diagnostic?
Indicator of chronic hyper/hypoglycemia
What levels of insulin are inappropriate when a patient has a BG <60 mg/dL?
Normal to high - suggestive of an insulin-secreting tumor
Fructosamine values below the RI suggest chronic _____.
hypoglycemia
How is the amended insulin : glucose ratio measured?
(Insulin/BG) - 30
When is an AIGR suggestive of insulinoma?
When the ratio is >30
What is the specificity of the AIGR?
Poor due to other causes of hypoglycemia
When is pre-op stabilization/medical management for insulinomas indicated?
Always
What should be avoided when acutely managing a hypoglycemic crisis?
dextrose boluses
What can be done when acutely managing hypoglycemic crisis?
Get patient to eat small, frequent meals, 2.5-7.5% dextrose in fluids, +/- glucagon
Why don’t we bolus with dextrose for insulinomas?
Insulinomas retain some sensitivity to plasma glucose concentrations;
Spikes in BG/dextrose will stimulate insulin release worsening the hypoglycemia;
Causes unpredictable, dangerous, and potentially fatal fluctuations in [BG]
What is the ideal diet for a patient with an insulinoma?
High protein, low fat, complex CHO
(Hill’s w/d, Purina OM)
What things can be added to the diet when there is hypoglycemic crisis?
Corn syrup, honey, maple syrup
How often should patients with insulinomas be fed?
every 4-8 hours;
should NOT be fasted
When can insulinoma patients be fed prior to surgery?
2-3 hours before surgery
What is the outcome and prognosis for an insulinoma patient on medical therapy alone?
MST = 74-124 days;
Use pred and diazoxide
What is the outcome and prognosis for an insulinoma patient with a partial pancreatectomy?
MST = 12-14 months;
(Enucleation instead will give MST of 11.5 months)
How many insulinoma petients will have gross metastasis at the time of surgery?
31-50%
How many insulinoma patients will have reoccurrence of CS suggesting microscopic metastasis?
Nearly 100%
What is a negative prognostic factor for insulinoma patients post-op?
Post-op hypoglycemia
What age and [insulin] are associated with shorter survival in insulinoma patients?
Young age and high [insulin]
What is a stage 1 insulinoma?
Dz limited to pancreas (no metastasis)
What is a stage 2 insulinoma?
Tumor spread to local LNs
What is a stage 3 insulinoma?
Tumor with distant metastasis with or without local LNs
