Surgery of the Spleen Flashcards
The head of spleen is attached to which aspect of the stomach and how?
Greater curvature; gastrosplenic ligament
The celiac artery which branches from the A) divides into B (3) arteries
A) abdominal aorta
B) hepatic, left gastric and splenic
Branches from the splenic artery supply the pancreas and there are branches that travel cranially and then through the A) ligament to supply the short gastric arteries.
gastrosplenic
At the level of the mid-spleen the splenic artery becomes the ? artery which branches to supply the caudal spleen.
left gastroepiploic
Physiological functions of the spleen?
Haematopoiesis
Immune response
Reservoir
Although splenic haematopoiesis is unusual in adults, it can occur in response to?
Demands from chronic hypoxia
The spleen is a major site of ? in foetal development.
extramedullary haematopoiesis
Red blood cells (RBCs) spend several days in the spleen following production; then what happens? (3)
Cell size is reduced,
the cell is contoured into a disc like shape
intracellular material is removed.
Old and/or damaged red blood cells may also be removed from circulation in the spleen
What is recovered from these cells; where are they stored and transferred to?
Iron recovered from these cells is stored in the spleen and then transferred to the bone marrow.
Filtration of microorganisms from the blood via ? is a key function of the spleen.
phagocytosis
What immune cells does the spleen produce a significant number of? (3)
B
T
IgM
Immunity in the spleen:
A microorganism will arrive and be taken up by?
A splenic macrophage
Following splenic macrophage; this then leads to the production of B-cells which generate A). . B) are recruited and prevented from leaving the site of antigen presentation to maximise the immune response.
A) antibodies
B) Lymphocytes
Neutrophil A) and B) activation also occur in the spleen.
A) phagocytosis
B) complement
This immune function can have a negative role as well as it is here that red blood cells and platelets covered in antibody are removed from circulation in i? (2)
Immune mediated thrombocytopaenia (IMTP) and immune mediated haemolytic anaemia (IMHA).
In dogs, what % of RBC can be stored in the spleen?
20
In dogs what % of platelets can be stored in the spleen?
30
Physiological demands can cause contraction of the spleen via smooth muscle stimulation and vasopressors leasing to 98% of the blood moving into the rapid pool which takes just 30 seconds to cross and re-enter the circulation. What happens to splenic size in this time?
Splenic size at this point can be as little as ¼ of normal.
Generalised splenomegaly can occur due to (4)
inflammation, hyperplasia, congestion or infiltration.
Splenic inflammation or splenitis can be due to exposure to ?
an infectious organism (bacteria, virus, fungi or protozoa).
If the splenitis is infectious then ? will be the dominant cell population, and this can lead to localised abscessation in some cases.
neutrophils
Eosinophilic splenitis can be seen in some cases secondary to?
eosinophilic gastroenteritis.
In cats, cases of Feline Infectious Peritonitis can have a ? splenitis.
pyogranulomatous
Emboli or thrombi that occlude the splenic vasculature can lead to hypoxic areas and growth of ? spp. and necrotising splenitis.
Clostridium
(2) can lead to splenic macrophage hyperplasia and splenomegaly.
Leishmaniasis and histoplasmosis
(2) can lead to B-cell and T-cell lymphoid hyperplasia.
Chronic osteomyelitis or bacterial endocarditis
A splenomegaly associated with splenic myeloid metaplasia and histiocytosis has been reported with what prognosis?
poor prognosis, 70% of dogs died within a year of splenectomy
Splenic congestion can cause generalised splenomegaly and can be seen with changes in vascular pressure such as (3)
with congestive heart failure
portal hypertension
increased outflow resistance such as in a vascular obstruction.
What drugs can relax smooth muscle of the splenic capsule leading to splenomegaly? (2)
Barbituate
PHenothiazine
Splenic amyloidosis and lysosomal storage diseases can also cause generalised splenomegaly. How common?
Rare
Localised splenomegaly is common in dogs. It can have a number of causes, the most common are? (3)
Nodular hyperplasia
Haematoma
Haemangiosarcoma
In dogs, splenic neoplasia is commonly..?
Localised
In cats, splenic neoplasia is commonly..?
Generalised
What neoplasia can all cause a neoplastic localised splenomegaly? (7)
Lymphoid
mast cell
histiocytic
plasma cell
hemangiosarcoma
sarcoma,
connective tissue tumours
myeloproliferative disease
Most common splenic neoplasia?
Haemangiosarcoma
Can nodular hyperplasia and neoplastic splenic nodules be differentiated at surgery?
No
Splenic nodules composed of what cells can cause localised splenomegaly. (4)
lymphoid,
erythroid,
myeloid
megakaryocyte cells
Splenic nodules are usually being though there is a suggestion that they can progress to become..?
Haematoma
Splenic abscesses are rare and are typically secondary to (2)
damage or obstruction to the splenic vascular system.
Parasitic cysts secondary to what have been reported in the spleen? (More common in wild species tho!) (2)
Echinococcus spp. and Cysticercus spp.,
What imaging can identify splenic infarction? (3)
Contrast CT or MRI can identify these lesions with good sensitivity and ultrasonographic changes of focal hypoechoic well demarcated lesions that do not alter the splenic contour are suggestive.
What is a hamartoma?
A benign proliferation of cells and tissues that are normally present in the spleen but without the normal splenic architecture.
What is this:
Benign and solitary splenic masses made of formed vascular spaces.
Haematoma
What is a “psuedotumour”
A rare benign mass of plasma cells, lymphocytes and histiocytes.
Select the false statement.
When there is a hamartoma, the splenic architecture is not altered.
The most common cause of neoplastic localised splenomegaly is hemangiosarcoma.
Segmental splenic infarction alone is not an indication for surgery.
When there is a hamartoma, the splenic architecture is not altered.
What peritoneal fluid sample is suggestive of a splenic, liver or kidney bleed?
packed cell volume (PCV) equal or greater than that of the peripheral circulation is supportive of haemorrhage from the spleen, liver or kidneys.
Abdominal compression bandages have been used in an attempt to generate pressure to control splenic bleeding, but they can worsen what?
Pulmonary function
If emergency surgery is to be performed in cases of splenic trauma it is wise to consider
blood typing and transfusion options
Prognosis for splenectomy following spleen trauma?
Excellent
Splenic torsion is most common in what breed?
large breed barrel chested dogs
What signs do chronic splenic torsions present with? (6)
Abdo discomfort
PUPD
V+
Anorexia
Weight loss
Lethargy
How do acute cases of splenic torsions present?
Shock
Blood result changes with splenic torsion? (Although not specific just to this!) (5)
Anaemia
Thrombocytopneia
Leukocytosiis
Liver values
Panc values
What do xrays show with splenic torsion? (2)
normal splenic silhouette may be absent or replaced by a C-shaped spleen
What is a splenic torsion seen as on ct?
Corkscrew like abdominal mass.
Best imaging for splenic torsion?
U/S
Splenic torsion general findings on U/S? (2)
splenomegaly
diffusely hypoechoic parenchyma
Splenic torsion chronic U/S changes?
Gas pockets (Ischaemia + necrosis)
Treatment for splenic torsion? CARE!!! - Why?
Once stabilised, surgery for splenectomy without de-rotation is the treatment of choice. If the torsed spleen is de-rotated it risks sudden release of free radicals, thrombi and sequestered blood with the potential to cause marked systemic effects.
At surgery for splenic torsion; what should be considered?
Prophylactic gastropexy should be considered due to the potential association with GDV.
Splenic haemangiosarcoma breeds? (3)
GSD
Labrador
Golden retriever
What origin are haemagiosarcomas?
Endothelial
What other masses in the thorax may be present with haemangiosarcoma? (2)
right atrial masses
masses on the auricular appendage
Where in the throax may splenic haemangiosarcoma met to? (3)
sternal and tracheobronchial lymph nodes
lungs
pleural nodules
Other than haemoabdomen, how may splenic neoplasia present? (9)
anorexia, weight loss, abdominal distension (masses can be large), PUPD, lethargy, weakness, vomiting, arrhythmia, or collapse.
Relation between PCV, splenic neoplasia and mets?
odds of malignancy increase threefold for every 10% reduction in PCV
Why is CT or echography advised with unexplained haemoabdomen?
risk of right atrial masses
T or F
Size of lesion is predictive of met nature?
False
Thorax radiograph with splenic neoplasia - to look for what? (2)
- Mets
- Changes to cardiac silhouette
Treatment of splenic neoplasia?
Following stabilisation (and staging where possible) a complete splenectomy and biopsy of other abdominal viscera
Why use ECG in splenectomy for haemangiosarc?
quarter of dogs undergoing splenectomy for hemangiosarcoma had ventricular arrhythmias during surgery with this figure rising to 40% post-operatively
Peri-op mortality with splenic haemangiosarc?
8%
Should a partial splenecotmy be considered for a suspected benign nodule?
No - you cannot distinguish at surgery!
It is possible to preform the splenectomy at the level of ? and double ligate, staple or seal the hilar vessels or a quicker method is to isolate the three main feeder vessels and double ligate them (rapid splenectomy).
the hilus (hilar approach)
What 3 vessels are involved in a rapid splenectomy?
gastric arteries,
the gastroepiploic artery
and the splenic artery
When tying the splenic artery - how to tie this differently?
transfixed to avoid suture migration
If performing a partial splenectomy, the spleen is exteriorised and the area to be resected isolated with saline soaked laparotomy swabs. The hilar vessels supplying this area are then ligated and resected.
What is then seen?
An ischemic line
What needs to be seperated in a partial splenectomy?
splenic parenchyma.
Recognised post opp complications of splenectomy? (4)
Haemorrhage
Pancreatic ischaemia
Cardiac arrythmia
Immunosupression
When does splenic ischaemia occur following splenectomy?
Only if the ligature on the splenic artery is placed too close to the left limb of the pancreas.
