8. Surgery of Pancreas and Spleen Flashcards
The spleen is located within what structure of the stomach?
within the leaf of the greater omentum
How is the spleen attached to the stomach and what is the significance of this structure?
gastrosplenic ligament (def. contributes to disease)
What are the branches that supply blood TO the spleen? and what drains blood out of the spleen?
- Blood in (Celiac a.—-> Splenic a.)
- Blood out (Splenic vein—>gastrosplenic vein—> portal vein)
What is the difference between the white pulp and the red pulp in terms of the parenchyma of the spleen?
- White pulp (immune response)= nodular lymphoreticular tissue
- Red pulp = Venous sinuses where RBC and Antigens are stored
What structures may resemble pathology in the spleen but are actually normal findings and their causes!!?? Which is most common
- Siderotic Plaques: (Calcium/iron deposits) MOST COMMON
- Ectopic splenic tissue
- Splenosis- usually from seeding of cells after sx or trauma
- Accessory spleen: congenital incidental
What are some of the general functions of the spleen? (5 main)
- RBC storage (10-20% RBC and 30% platelets)
- RBC maturation (SUMMER CAMP FOR RBC)
- Senescent/sick RBC removal
- A. (RBC life-4 months, become non pliable and can’t squeeze through pores of splenic sinuses= rupture or they are phagocytized
- Hematopoiesis
- Immune Function (removal of bacteria better than the liver)
What are the 2 main Morphological classifications of splenic pathology?
- Splenomegaly (symmetric enlargement)
- Mass (assymetric enlargement)
What are some of the causes of Splenomegaly (symmetric enlargement)? (4)
- Drug induced
- Thiopental and Acepromazine (5-40% of blood can be sequestered during anesthesia)
- Propofol-minimal
- Congestion (TORSION) focus on this****
- Infiltrative diseases
- Immune mediated disease
What are the main causes of splenic mass (asymmetric enlargement)?
- Neoplasia
- Hematoma***
- Nodular hyperplasia/EMH****
- Trauma—> Splenosis
- Abcess
Splenic torsion may be an isolated event from_______ of the ______ ______(anatomical structure) during previous _____ or trauma or from absence of the ligament congenitally.
Splenic torsion may be an isolated event from STRETCHING** of the **GASTROSPLENIC LIGAMENT** (anatomical structure) during previous **GDV or trauma or from absence of the ligament congenitally.
MOST COMMONLY, Splenic torsion is associated with this problem
GDV
What breeds are associated with splenic torsion? (4)
Large & giant breeds
– Great Dane
– Greater Swiss Mountain dog
– German Shepherd
– English Bulldog (not asc with GDV)
Above breeds accont for 50% of cases
Clinical signs of splenic torsion can either be _____ or _____
acute or chronic
Describe the acute CS of splenic torsion? (6)
• Acute abdomen – Similar to GDV or BECAUSE of GDV
– Acute abdominal pain/shock
– Abdominal distention
– Cardiovascular collapse
– Dysrhythmias
– DIC
Describe the chronic CS of splenic torsion? (6)
• Vague/Intermittent signs for up to 2 weeks
– Vomiting / diarrhea
– Weakness /depression
– Anemia
– Hematuria / Hemoglobinuria
– PU/PD
What is the best imaging modality to differetiate from splenic torsion or from splenic mass, what are you looking for?
Ultrasonography (flow)
– Mottled/diffuse hypoechoic areas
– Intraluminal echogenic densities in veins
– No flow in splenic vessels in torsion
Rads are okay for splenic torsion but not as good as U/S, why do we see gas bubbles often with torsions?
That portion of spleen dies off and attracts anaerobic bacteria and they often expire CO2 gas bubbles
On radiographs, splenic masses are normally top ranked but many people will forget this problem that should be on their differentials because it often resembles a splenic mass on rads?
Splenic torsion
Besides preop stabilization (fluids, transfusion, ab) what is the treatment of choice for Splenic torsion?
Exploratory Laparotomy to perform a splenectomy.
What procedure will be often do upon exploratory laparotomy to treat splenic torsion to take out the spleen?
Gastropexy (especially with large breeds, small cohort study actually found GDV assoc. with splenic torsion potential)
What do you never do to a splenic torson when performing a splenectomy?
DO NOT EVER DEROTATE THE SPLEEN PRIOR TO SPLENECTOMY
When submitting a histopath assessment to ensure no underlying pathology to the lab it is IDEAL to send it how?
Send the whole spleen!!!
What is the survival rate from splenic torsion?
93 of 102 so (91%) this is great!!!
What is most definitely NEVER a cause of splenic torsion (DR. C did a study that proved this potential cause once considered is not found in ANY cause)??
Neoplasia
What is a rare cause of splenomegally where you find areas of infarct on abdominal u/s?
Splenic Infarction
Can we see splenic infarction on radiographs?
All we see is an enlarged spleen so rely on U/s to see infarct areas
Is Splenic infarction an emergency surgery potential?
DON”T RACE TO SURGERY!!! Figure out why first
What predisposes to splenic infarction?
prior splenic torsion caused from devascularized area that may turn into a mass effect such as a heatoma (POOR DR.C he said this happened to him!!!) Vasa ractus blood flow at the hilus must always be palpated
These hypercoaguaguable states can possibly cause splenic infarction? (5)
– Renal disease (PLN)
– Hyperadrenocorticism
– Neoplasia
– DIC
– Heart disease
Describe a very common entity with EMH and what is it often caused by?
DIFFUSE or NODULAR HYPERPLASIA from immune stimulation (Rickettsial infection) or splenic hyperactivity (IMHA – removing abnormal cells)
Nodular hyperplasia = sites of ______ ______
- ____________
- ____________
- ____________
• Nodular hyperplasia = Sites of extramedullary hematopoiesis
– Single or multiple SUBCAPSULAR nodules
– *Very Common entity*
True or False
Diffuse or Nodular hyperplasia can often resemble cancer and FNA/cytology is a good dx madality to use
False- poor sensitivity
Nodular hyperplasia is often ______ but could _____ causing a ________
Nodular hyperplasia is often asymptomatic but could rupture causing a hemoabdomen
True or False:
Most nodular hyperplasias are malignant
False!!!!
70.5% (74/105) patients had benign splenic lesions
But of the 29.5% that we’re malignant most were hamangiosarcoma :-(
What is the key point inf differentiating nodular hyperplasia from cancerous malignancies?
• Incidentally found, non-ruptured splenic masses or nodules w/o associated hemoperitoneum = Most commonly benign!
– Work w/ radiologist to help you rank ddx based on u/s characteristics
What are some causes of splenic trauma resulting in splenomegally?
• Blunt force (HBC/falls/dog attack) – Ruptures capsule & parenchyma
– Iatrogenic d/t laparotomy = Hemostatic agent & tamponade
What type of management is preferred for splenic trauma?
• Conservative management preferred & successful
– Compression bandage = Controversial but this is the time to use it
– Supportive care (careful PCV/TS tracking) & transfusion PRN
With splenic trauma treatment with splenectomy is partial considered for large breeds?
Splenectomy - Consider partial if possible but in at risk breeds for splenic disease (labs/golden/GSD) please remove ALL
What are our top 2 differentials for dogs with spenic neoplsia versus in cats?
Dogs
- Hemangiosarcoma
- Sarcoma (Fibrosarcoma, leiomyosarcoma, osteosarcoma)
Cats
- Mast cell tumor (MOST COMMON)
What is the rule of 2/3 with splenic neoplasia?
***RULE OF 2/3rd’s***
- 2/3rd’s of dogs w/ a splenic masses will have a malignancy
- 2/3rd’s of those malignancies will be hemangiosarcoma (HSA)
=66.6%
What is the difference in prognosis with small dogs versus large breeds, what is asc with malignancy in large breeds but not in small breeds?
Small breed dogs (<16 kg)
- 50:50 split = Benign vs. malignant
- Wheaten Terriers predisposed
• Hemoperitoneum NOT associated w/ malignancy
NOT A POOR PROGNOSIS IN SMALL BREED, poor prognosis in large breeds
What are some of the risk factors for hemangiosarcoma with splenic neoplasia?
- Age – Older
- Size of dog - > 21kg
- Breed – GSD, labs, Goldens, poodles
• Presence of hemoperitoneum = > chance of malignancy =>80%!!! (HOLY SHIT)
What is an interesting discovery in terms of splenic mass size and prognostics?
- SIZE MATTER
- Bigger the mass the better the prognosis
- Smaller the mass the worse the prognosis :-(
WE must know the numbers for HSA prognosis
- Outcome is _____
- If surgery how long do we get?
- Surgery + Chemo (Dox + Palladia) MST?
- Surgery + chemo + Immunotherpay MST? STAGES AND NUMBERS
- What is the major issue?
WE must know the numbers for HSA prognosis
- Outcome is POOR
- If surgery how long do we get?
- 1-3 MONTHS (JUST SAY 3 MONTHS)
- Surgery + Chemo (Dox + Palladia) MST?
- 6-7 MONTHS (SLIDE SAID 5-6) 1 YEAR SURVIVAL ONLY HAPPENS IN 10% OF PATIENTS
- Surgery + chemo + Immunotherpay MST?
- STAGE 1: (non ruptured spleen -425 days
- Stage 2: NO BENEFIT to do this
- _**Issue is that in nearly ALL cases microscopic metastasis is present at the time of diagnosis**_
MOST vets when hemangiosarcoma will opt to not take it out because the prognosis of poor but what does Dr. C want to encourage us todo? When should we not indicate surgery?
State the survival stats we have to commit to memory but he does feel it is worth it often to give them more time and months alive!!!
I DO feel comfortable doing surgery for this disease, even in at risk breeds w/ hemoperitoneum
• I do NOT feel good about surgery when:
– Obvious grossly visible metastasis present pre-op
– Very sick dogs (coagulopathic/those needing high volume transfusion)
– Owner is not informed
What is an alternative therapy that increased MST 112 or 30-308 days? What does it contain and do?
C versicolor mushroom (Turkey tail) used an an adjunctive therpay
• Contains polysaccharopeptide (PSP), which causes cell-cycle arrest at the G1/S checkpoint w/ alterations in apoptogenic & extracellular signaling proteins
– Net result = Reduction in proliferation & in apoptosis in cancer cells
There is now a future prospective vaccine that holds promise with HSA cancer cells because of this vaccines ability to target those stem cells secreted by HSA……what are those cells secreted and how does this vaccine work?
- HSA cancer stem cells shown to express EGFR & Urokinase plasminogen activator receptor (uPAR)
- eBAT (blocks EGFR)= Bispecific urokinase angiotoxin designed to target (inhibit) EGFR
– Mutation in EGFR = Triggers cancer cell to continue to grow/divide
- 6-month survival = 70% (historical control < 40%)
– 6 dogs w/ ST’s > 450 days
What are the 2 techniques considered when performing a complete splenectomy? Which is most common
- Ligation of individual hilar vessels (most common)
- Ligation of the splenic and short gastric aa.
What are the pro/con of ligation of indiv. hilar vesselv with a complete splenectomy?
- Predicable perseveration of vascular branches to pancreas and stomach
- Time consuming to do by hand
• Less risk of PO hemorrhage
What are the pro/con of ligation of the splenic and shortgastric aa. with a complete splenectomy?
– w/out compromising blood flow to greater curvature of stomach it can:
- decrease surgical time
- More challenging if large mass or omental adhesions distort anatomy
- Increased risk of major hemorrhage w/ technique failure :-(
What is the COMPLETE splenectomy referred technique if anatomic distortion of vasculature d/t adhesions or size of mass? Describe the 2 basic details?
Hilar Dissection
- Make sure to Isolate and double ligate vessels at hilus
- Preserves branches to pancreas & stomach