18. Surgical diseases of the pylorus and spleen. Aetiology, diagnosis and therapy. Pyloroplasty. Splenectomy.

What is the location of the spleen?

Left side of the cranial abdominal cavity, parallel to the abdominal wall, between the abdominal wall and stomach (curvatura major).

With what ligament is the spleen associated with the stomach?

Ligamentum gastrosplenicum.

With which other organ's blood supply is the spleen's associated?

The pancreas (pancreatic arteries).

What are the functions of the spleen?

Immunological and haematological: blood reservoir, blood filtration, IgG and cytokine synthesis, RBC maturation, platelet reservoir, removal of old platelets, and production of B and T lymphocytes and IgM.

What are the surgical diseases of the pylorus?

1. Stenosis

2. Obstruction

3. Neoplasia

What is the aetiology of pyloric stenosis?

1. Congenital in brachycephalic breeds.

2. Acquired in response to infection

What are clinical signs of pyloric stenosis?

Vomiting several hours after eating

How is pyloric stenosis diagnosed?

X-ray with contrast, endoscopy, biopsy (to exclude neoplasia)

What is the treatment for pyloric stenosis?

Surgical (pyloroplasty)

Medical treatment of oesophagitis, acid-base abnormalities and dehydration should be instituted before surgery

What is a common cause of pyloric obstruction?

Foreign bodies.

What is a common clinical sign of pyloric obstruction?

Vomiting.

How is pyloric obstruction diagnosed?

X-ray with or without contrast and endoscopy.

How is pyloric obstruction due to a foreign body treated?

Surgical removal of the foreign body.

What is a less common surgical disease of the pylorus?

Neoplasia.

What are examples of pyloric neoplasia?

1. Benign: adenoma

2. Malignant (more common): lymphoma (cats), adenocarcinoma, leiomyosarcoma

What are general clinical signs of pyloric disease?

Anorexia, vomiting, weight loss, decreased appetite with water intake only.

How are pyloric diseases diagnosed generally?

History, endoscopy, and barium contrast radiography.

What is pyloroplasty?

Surgery to widen the pyloric opening.

What are indications for a pyloropasty?

1. Recurrent gastric dilatation

2. Neoplasia

3. Hepatic or pancreatic abscesses

4. Specific inflammatory processes

5. Gastroduodenal ulcers

6. Congenital pyloric stenosis with hypertrophy of pyloric musculature

What are three common methods of pyloroplasty?

1. Fredet-Ramstedt pyloromyotomy

2. Y-U shaped

3. Heineke-Mikulicz.

What is the Fredet-Ramstedt pyloroplasty?

Performed by making longitudinal incision through serosa & muscularis of ventral pylorus. Only the serosa and muscularis should be incised, not mucosa (partial thickness incision)

What are the indications for Fredet-Ramstedt pyloroplasty?

Stenosis and chronic antral mucosal hypertrophy.

What is a limitation of the Fredet-Ramstedt pyloroplasty?

Limited visualisation into the lumen.

What is the Y-U shaped pyloroplasty?

1. Making a full-thickness Y-shaped incision

   1. Y-base: antimesenteric aspect of the duodenum and pyloric sphincter

   2. Y-arms: pyloric antrum

2. Advancing the U-shaped flap and suture to the base of the Y.

What is the Heineke-Mikulicz pyloroplasty?

A full-thickness longitudinal incision of the ventral pylorus closed transversely with an appositional interrupted pattern.

What is the advantage of the Heineke-Mikulicz pyloroplasty?

It is good for beginners.

What are surgeries for when pyloric outflow obstruction cannot be treated with a routine pyloroplasty?

Billroth I: Pylorectomy with end-to-end gastroduodenostomy

Billroth II: Resection of pylorus, antrum, and proximal duodenum with anastomosis of proximal jejunum and stomach

What are the surgical diseases of the spleen?

1. Torsion

2. Rupture/trauma

3. Neoplasia.

In which animals is splenic torsion more common?

Large/giant breed dogs that are deep-chested.

What is the pathophysiology of splenic torsion?

Occlusion of venous drainage, causing congestion, enlargement, and cyanosis.

With which other condition may splenic torsion occur?

GDV.

What are the clinical signs of splenic torsion?

Abdominal pain, vomiting, abdominal distension, inappetence, PU/PD.

How is splenic torsion diagnosed?

X-ray and USG.

What are radiographic findings in splenic torsion?

Missing splenic silhouette or a C-shaped appearance.

What is the most useful diagnostic tool for splenic torsion?

USG (detects splenomegaly and a lacy pattern).

How is splenic torsion treated?

1. Supportive therapy

2. Total splenectomy

3. Prophylactic gastropexy with partial splenectomy.

What are common causes of splenic rupture/trauma?

Penetrating foreign bodies (sticks, fence material, bite wounds, gunshot) or iatrogenic lacerations.

What are the clinical signs of splenic rupture/trauma?

Haemorrhage into the abdominal cavity, distended abdomen, pale mucous membranes, hypotension, acute abdomen, depression, and enlarged spleen.

Small bleedings may stop spontaneously. Large bleeding may lead to haemorrhagic shock.

How is splenic rupture/trauma diagnosed?

Abdominocentesis, X-ray, USG, and exploratory laparotomy.

How is splenic rupture/trauma treated?

Partial or total splenectomy and supportive therapy (blood transfusion).

What are common types of splenic neoplasia?

Haemangiosarcoma and haemangioma.

What is a characteristic of haemangiosarcoma and haemangioma?

They are "bleeding tumours" with widespread metastasis potential.

What are the clinical signs of splenic neoplasia?

Nonspecific signs, acute abdomen, abdominal distension, lethargy, and pale mucous membranes.

How is splenic neoplasia diagnosed?

X-ray and USG (showing fluid-filled cavities).

How is splenic neoplasia treated?

Patient stabilisation, total or partial splenectomy followed by chemotherapy.

What are examples of splenic surgical interventions?

1. Splenorrhaphy

2. Splenectomy

What is splenorrhaphy?

Surgical repair of small splenic lacerations or punctations with interrupted pattern.

What suture material and pattern are used in splenorrhaphy?

4-0 or 5-0 rapidly absorbable monofilament in an interrupted pattern.

What is splenectomy?

Surgical removal of the spleen.

What is a major consideration regarding splenectomy?

The spleen is a blood reservoir, so its removal will have related repercussions.

What are indications for splenectomy?

Haemangiosarcoma, GDV, splenic torsion, severe trauma, generalised infiltrative disease

What are the types of splenectomy?

Partial (rare) and total.

What is an advantage of partial splenectomy?

Preservation of some splenic function.

What is recommended for vessel ligation during splenectomy?

Double ligation.

What is the method for a partial splenectomy?

Elevate spleen from abdomen → Ligate or seal hilar vessels in area → may use automatic stapling device to separating parenchyma, or digital pressure (not to destroy capsule) → haemostatic clamp across separated parenchyma & second clamp 1-2 cm distally, & transect midway between clamps → Appose capsule w/ continuous absorbable material. A second line of continuous or interrupted mattress may be used to gain a more haemostatic effect.

What are methods for separating splenic parenchyma during partial splenectomy?

Automatic stapling devices or digital pressure.

What is the surgical approach for total splenectomy?

Midline celiotomy from xiphoid to pubis.

What is the method for a total splenectomy?

Elevate by gentle manipulation out of abdomen → double ligation of each vessel that remains in abdomen (if possible, preserve the short gastric branches supplying the gastric fundus) → Resect spleen. If spleen has ruptured at the time of surgery, lavage the abdominal cavity to prevent neoplastic cells entering.

How can an animal be tested to see if pyloroplasty is indicated?

When contrast agent is not evacuated from the stomach 12-24 hours after administration

Which breeds are more predisposed to requiring pyloroplasty?

Miniature and brachycephalic breeds

Which vessels are ligated in a complete splenectomy?

All vessels at splenic hilus (or splenic artery distal to the branches supplying left limb of the pancreas; pancreatic artery)