Splenic Surgery Definitions and Indications

Definitions Related to Splenic Surgery

• Splenomegaly refers to the enlargement of the spleen from any cause
• Splenectomy is the surgical removal of the spleen
• Splenosis is the congenital or traumatic presence of multiple nodules of normal splenic tissue in the abdomen
• Siderotic plaques are brown or rust-colored deposits of iron and calcium on the splenic surface
• Splenorrhaphy involves suturing a ruptured spleen
• Hemangiosarcoma (HSA) is a malignant neoplasm arising from blood vessels
• Hemangioma is a benign tumor of dilated blood vessels
• Hematoma refers to a swelling or mass of blood

Indications for Splenic Surgery

• Surgery may be needed due to a mass which can be neoplastic or non-neoplastic mass
• Loss of vascularity secondary to GDV or splenic torsion are also indications
• Trauma can warrant splenic surgery
• Refractive Immune-mediated hematologic disorders may be indications in some individual cases
• Incidentally found, non-ruptured splenic masses/nodules without hemoperitoneum are commonly benign and warrant surgery due to a fair/good prognosis

Diffuse (Symmetric) Splenomegaly

• Congestion caused by torsion, GDV, right-sided heart failure, or drugs can lead to symmetric splenomegaly
• Infiltration due to fungal, bacterial, or rickettsial infections can cause this condition
• A splenic foreign body may result in symmetric splenomegaly
• Immune-mediated diseases like IMHA or IM thrombocytopenia are potential causes
• Neoplasia, including lymphosarcoma, histiocytic sarcoma, and feline mastocytosis, can cause diffuse splenomegaly

Focal (Asymmetric) Splenomegaly

• Benign processes such as nodular regeneration, hematoma, or trauma can result in focal splenomegaly
• Neoplastic processes can be caused by hemangiosarcoma (HSA)
• Infiltrative splenomegaly from neoplasia is one of the most common causes of spontaneous splenomegaly in dogs and cats

Splenic Torsion

• Splenic torsion is most often associated with GDV but isolated splenic torsion is rare in dogs
• The splenic vein becomes occluded and the splenic artery is partially blocked resulting in infarction
• Splenomegaly is a common finding
• Signs can be acute or intermittent, lasting for weeks
• The cause is often unclear but may involve congenital abnormalities or traumatic disruption of the gastrosplenic or splenocolic ligaments, although partial GDV that resolved may be a factor
• Acute splenic torsion is a life-threatening condition requiring prompt diagnosis and treatment
• It is associated with cardiovascular collapse and shock, increased likelihood of GDV, septicemia from massive bacterial overgrowth in the necrotic splenic tissue, and hemoabdomen
• Prophylactic gastropexy with splenectomy may be warranted after splenic torsion because of stretching of the gastric ligaments resulting in increased likelihood of GDV
• Research has called this practice into question when splenectomy was not related to a GDV or splenic torsion

Other Diseases Associated with Splenic Infarction

• Altered blood flow and coagulation can be associated with liver disease, renal disease, hyperadrenocorticism, neoplasia, or thrombus with cardiovascular disease

Splenic Neoplasia

• Hemangiosarcoma (HSA) is the most common splenic tumor in dogs
• Canine splenic HSA is more common than all other types of malignant splenic tumors, accounting for approximately half of all splenic malignancies
• This is the most common malignant splenic tumor in cats
• As many as 25% of dogs with splenic HSA may have concurrent right atrial HSA, so an echocardiogram in non-emergent splenectomy to remove a splenic mass is warranted
• Canine splenic HSA may be seen in more than one-third of dogs presenting with acute nontraumatic hemoabdomen
• Hemangiosarcomas (HSAs) are aggressive tumors that frequently metastasize to the liver, omentum, mesentery, and brain
• Most dogs with HSA have gross evidence of metastatic disease on initial presentation.
• Splenic hematomas/hemangiomas are often grossly indistinguishable from hemangiosarcomas

Preoperative Management

• Anemia should be managed by identifying the cause such as acute hemorrhage with trauma, rupture of a hematoma, or underlying disease
• Coagulation profiles should be performed if trauma is not suspected as the cause of hemorrhage
• The need for blood transfusion should be considered if PCV is less than 20% or HGB is less than 5-7 g/dl
• Assess for hydration and DIC

Anesthesia

• Anemic patients need O2 prior to induction and during recovery
• Avoid barbiturates because they cause splenic congestion
• Avoid acetylpromazine because it can cause red blood cell sequestration, hypotension, and impact platelet function
• Hypotension can be due to volume depletion

Antibiotic Considerations

• Antibiotic usage is case-dependent, considering age, disease, length of surgery, immune status, and state of debilitation
• Multiple abscessation, septicemia, and death associated with splenectomy performed in conjunction with dental cleaning and extraction has occurred in dogs

Instrumentation

• Instrumentation for this procedure includes a suction machine and sterile tubing
• This procedure utilizes a Poole suction tip and laparotomy pads
• You may need a Balfour retractor from a "spay pack", LDS - Ligating Dividing Stapler and/or TIA Stapling Device – Transverse Intestinal Stapler

Surgical Anatomy

• The spleen can be found almost anywhere in the abdominal cavity
• The arterial supply is from the splenic artery, a branch of the celiac artery that normally gives off 3 to 5 branches
• The first branch is usually to the left limb of the pancreas and is its main arterial blood supply; the pancreatic supply coming off of the splenic artery must be identified and ligated distal to it
• The short gastric arteries are often avulsed in dogs with GDV

Surgical Technique

• A ventral midline approach from the xyphoid to a point caudal to the umbilicus is used and is longer for large lesions or complete exploratory procedures
• A complete exploratory is performed if neoplasia is suspected
• Balfour retractors may be used if needed

Partial vs Total Splenectomy

• Partial splenectomy is indicated with trauma or focal lesions to preserve splenic function
• Total splenectomy results in loss of all splenic function including RBC reservoir, hematopoiesis, important phagocytic function, and help with immunocompetence
• It is contraindicated in bone marrow hypoplasia

Splenectomy: Surgical techniques

• Major techniques include: Ligation at splenic hilus, splenic artery ligation, Bag Of Rochester Carmalts, and/or Laparoscopic?

Postoperative Care and Assessment

• Include a 24-hour observation for hemorrhage to differentiate normal blood loss vs. bleeding out
• Hematocrit should be checked every few hours until stable as well as administration of nasal O2 for anemic patients (transfuse if falls <20%)
• Fluid therapy until self hydration and electrolyte and acid-base correction (PRN) are recommended
• Monitor for cardiac arrhythmias more common with hemoabdomen, anemia, or both and DIC (especially if you think HSA)
• Antibiotics after 24 hours only if warranted with appropriate pain management

Complications

• Hemorrhage is more problematic with biopsies or partial splenectomy
• Traumatic pancreatitis can occur
• Gastric fistulation can be due to impairment of gastric blood flow
• Previous infection with hemoparasites (Babesia, Ehrlichia, Mycoplasma) may become apparent after splenectomy

Histopathology

• Histologic diagnosis and differentiation of HSA may be difficult so several sections of the mass should be submitted to the pathologist