83. Spleen Flashcards

1
Q

What are the typical clinical signs of splenic neoplasia?

A

The typical clinical signs of splenic neoplasia include decreased appetite, anorexia, weight loss, abdominal distention, polydipsia, lethargy, weakness, vomiting, cardiac arrhythmias, and collapse.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

What are the common splenic neoplasms in dogs?

A

The common splenic neoplasms in dogs are leiomyosarcoma, undifferentiated sarcoma, fibrosarcoma, osteosarcoma, liposarcoma, myxosarcoma, mast cell tumor, chondrosarcoma, rhabdomyosarcoma, malignant fibrous histiocytoma, lymphoma, metastatic adenocarcinoma, and myeloproliferative disease.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

What is the most likely cause of splenic disease in cats?

A

In cats, splenic disease is most likely to be neoplastic; in one retrospective study, 73% of cats with sonographic evidence of splenic disease were ultimately diagnosed with splenic neoplasia.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

What are the most common splenic neoplasms in cats?

A

The most common splenic neoplasms in cats are lymphosarcoma and mast cell tumors.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

What are the hematologic changes commonly seen in dogs with splenic neoplasia?

A

The hematologic changes commonly seen in dogs with splenic neoplasia are anemia, mature neutrophilic leukocytosis, and increased total bilirubin and liver enzyme concentrations.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

What radiographic findings are seen in dogs with splenic neoplasia?

A

Abdominal radiographic findings include an abdominal mass and loss of detail consistent with effusion. Thoracic radiographs are recommended to look for pulmonary metastatic lesions, effusion, sternal lymph node enlargement, and changes in the cardiac silhouette.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

What is the recommended diagnostic imaging modality for identifying and characterizing splenic lesions and metastases?

A

Abdominal ultrasonography is an excellent modality for identifying and characterizing effusion, splenic lesions, and metastases.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

What is the recommended treatment for splenic neoplasia?

A

Patient stabilization and complete splenectomy with biopsy of other abdominal sites as indicated.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

What is the reported incidence of acute portal vein thrombosis (PVT) after splenectomy in dogs?

A

Acute portal vein thrombosis (PVT) was reported in six dogs 24 to 48 hours after splenectomy.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

How many dogs survived to discharge in a retrospective study of 33 dogs with PVT associated with various disease processes?

A

19 dogs survived to discharge in the retrospective study of 33 dogs with PVT.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

What percentage of dogs presented for splenectomy were diagnosed with ventricular tachycardia in a prospective study?

A

44% of dogs presented for splenectomy were diagnosed with ventricular tachycardia in a prospective study of 50 dogs.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

What percentage of dogs with splenic hemangiosarcoma, hematoma, or leiomyosarcoma were diagnosed with arrhythmias in a retrospective study?

A

35% of dogs with splenic hemangiosarcoma, hematoma, or leiomyosarcoma were diagnosed with arrhythmias in a retrospective study of 106 dogs.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

What are some factors that may contribute to the development of ventricular arrhythmias in dogs after splenectomy?

A

Factors that may contribute to the development of ventricular arrhythmias include anemia, hypotension, leukocytosis, and splenic mass rupture.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

What treatment options are generally reserved for patients with hemodynamic instability, multiform ECG complexes, very rapid ventricular tachycardia, or R-on-T complex after splenectomy?

A

Treatment options generally reserved for such patients include membrane stabilizers such as lidocaine HCl or procainamide HCl.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

What are some complications associated with splenic disease in veterinary patients?

A

Complications can include disseminated intravascular coagulation, pulmonary thromboembolism, acute respiratory distress syndrome, and systemic inflammatory response syndrome (SIRS).

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

What can be a risk factor for disseminated intravascular coagulation after splenic surgery?

A

Hemangiosarcoma of any origin is significantly overrepresented and can be a risk factor for disseminated intravascular coagulation after splenic surgery.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

What are some postoperative care measures for splenorrhaphy?

A

Postoperative care measures for splenorrhaphy include IVFT, continuous ECG monitoring, supplemental oxygen or transfusions as needed, pain medication, and nutritional support.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

What is the surgical technique used for splenorrhaphy?

A

The surgical technique for splenorrhaphy involves apposing the capsule in an interrupted mattress pattern with 4-0 or 5-0, rapidly absorbable, monofilament suture on a taper needle.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

When is partial splenectomy performed?

A

Partial splenectomy is performed in cases of focal splenic abscess or injury.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

What is the surgical technique used for partial splenectomy?

A

The surgical technique for partial splenectomy involves identifying and ligating or sealing the hilar vessels supplying the area to be resected. The TA stapler is then used to transect the spleen, and the distal capsule is apposed with absorbable suture.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

When is complete splenectomy performed?

A

Complete splenectomy is performed when gastric blood flow is not compromised and involves ligation of the left gastroepiploic and short gastric arteries and veins, along with the splenic artery and vein.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

What are some methods used for vessel ligation during splenectomy?

A

Methods used for vessel ligation during splenectomy include LigaSure to seal vessels up to 7 mm in diameter and hemostatic clips for vessels no greater than 3 mm in diameter.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

What are some surgical conditions of the spleen?

A

Some surgical conditions of the spleen include splenic trauma and splenic torsion.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

What breeds of dogs are more commonly affected by splenic torsion?

A

Large- and giant-breed dogs that have a deep-chested body type, including Great Danes, Saint Bernards, German Shepherds, and Irish Setters, are more commonly affected by splenic torsion.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
Q

What is Gastric Dilatation Volvulus (GDV)?

A

Gastric Dilatation Volvulus is a condition in which the stomach becomes distended and twists on its longitudinal axis.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
26
Q

What is the median time reported for GDV occurrence after splenectomy?

A

The median time reported for GDV occurrence after splenectomy is 352 days.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
27
Q

What are some risk factors that may increase the likelihood of GDV in dogs undergoing splenectomy?

A

Some risk factors that may increase the likelihood of GDV in dogs undergoing splenectomy are large or giant breed, sexually intact male, and stretching of supporting ligaments by an expanding splenic mass.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
28
Q

Why are splenectomized animals believed to be at a higher risk for infection?

A

Splenectomized animals are believed to be at a higher risk for infection because the spleen is the primary site for the removal of infected red blood cells by bacteria, rickettsial agents, and hemoparasites.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
29
Q

What is the recommended approach for identifying pathogens and their antimicrobial resistance in splenectomized animals?

A

The recommended approach for identifying pathogens and their antimicrobial resistance in splenectomized animals is to culture congested spleens at the time of surgery.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
30
Q

What risks are associated with acute blood loss in splenectomized animals?

A

Splenectomized animals are at a higher risk for hypoxia and ischemia in the event of acute blood loss because they lack the splenic reservoir for immediate supplementation of circulating red blood cell volume.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
31
Q

How does splenectomy impact oxygen transport and maximal exercise capacity in athletic animals?

A

Splenectomy eliminates the exercise-induced increase in hematocrit, which is one mechanism in achieving oxygen transport and subsequent maximal exercise capacity in athletic animals.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
32
Q

In which animals can splenectomy result in catastrophic anemia and death?

A

In animals in which the spleen serves as the primary site of erythropoiesis, such as those with primary bone marrow disorders, splenectomy may result in catastrophic anemia and death.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
33
Q

What imaging techniques are commonly used in human medicine to differentiate hamartomas from other benign masses?

A

Computed tomography (CT) and magnetic resonance imaging (MRI)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
34
Q

What are the possible causes of focal lesions in the spleen?

A

Splenic foreign body, chronic suppurative splenitis, and replication of bacterial agents within the parenchyma

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
35
Q

What type of splenic lesion is uncommon in dogs and rare in cats?

A

Abscess

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
36
Q

Which parasitic cysts have been reported in the spleen?

A

Parasitic cysts formed by intermediate stages of Echinococcus granulosa and Cysticercus tenuicollis

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
37
Q

What is the characteristic appearance of segmental infarctions in the spleen?

A

Wedge-shaped, with the base at the periphery, but can also be nodular or involve an entire extremity

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
38
Q

What imaging techniques are useful for diagnosing splenic infarction?

A

Computed tomography scan with intravenous nonionic contrast and MRI with intravenous gadolinium contrast

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
39
Q

What are some predisposing causes of splenic infarction in dogs?

A

Hypercoagulable states, splenomegaly, cardiac disease, neoplasia, liver or renal disease, excessive corticosteroids, sepsis, splenic hematoma, and vasculitis

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
40
Q

What are siderotic plaques and siderocalcific plaques?

A

Siderotic plaques are benign golden brown or black patches resulting from iron accumulation, while siderocalcific plaques are dry encrustations containing hemosiderin, bilirubin, and calcium

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
41
Q

What conditions can alter venous drainage in the spleen?

A

Abscess, neoplasms, and adhesions can alter venous drainage in the spleen.

42
Q

What can cause GDV (gastric dilatation-volvulus) in relation to the spleen?

A

GDV can be caused by venous compression and stretching in the spleen.

43
Q

How does the feline spleen differ from other species in terms of physiological splenomegaly?

A

Severe splenomegaly is less likely to be physiologic in origin in feline species, as the feline spleen has a nonsinusal design.

44
Q

What are some neoplastic causes of generalized splenomegaly?

A

Myeloproliferative neoplasia, such as lymphosarcoma and mastocytosis, are common neoplastic causes of generalized splenomegaly.

45
Q

What breed of dogs are considered to have an increased risk for splenic histiocytic sarcoma?

A

Flat-Coated Retrievers, Rottweiler Dogs, Bernese Mountain Dogs, and Golden Retrievers are considered to have an increased risk for splenic histiocytic sarcoma.

46
Q

What is the most common metastatic lesion of the spleen?

A

Lymphoma is the most common metastatic lesion of the spleen.

47
Q

What are lysosomal storage diseases and how do they affect the spleen?

A

Lysosomal storage diseases are inherited metabolic defects that result in the accumulation of lipids or carbohydrates in the spleen. Macrophages in the spleen are unable to process these substrates, leading to their storage in an unprocessed form.

48
Q

What is the histological appearance of the spleen in dogs with splenic amyloidosis?

A

In dogs with splenic amyloidosis, the spleen appears pale beige, firm, and waxy.

49
Q

What were the significant risk factors for perioperative death in dogs undergoing splenectomy for mass lesions?

A

Marked preoperative thrombocytopenia or anemia and development of intraoperative ventricular arrhythmias.

50
Q

What were the most common causes of death in dogs undergoing splenectomy for mass lesions?

A

Uncontrolled hemorrhage from metastatic lesions and thrombotic and coagulopathic syndromes.

51
Q

What was the 2-month survival rate after splenectomy for dogs with splenic hemangiosarcoma?

A

31% for dogs with splenic hemangiosarcoma.

52
Q

What was the 1-year survival rate after splenectomy for dogs with nonneoplastic hematomas?

A

64% for dogs with nonneoplastic hematomas.

53
Q

What was the median survival time for dogs with hemangiosarcoma treated solely by splenectomy?

A

Median survival times ranged from 19 to 65 days.

54
Q

What factors may influence the prognosis of dogs with splenic hemangiosarcoma treated with splenectomy alone?

A

Tumor stage, number of gross lesions, and age at the time of diagnosis.

55
Q

What does adjunctive chemotherapy after splenectomy do for dogs with hemangiosarcoma?

A

It has been shown to increase survival times.

56
Q

What is the most cited chemotherapeutic agent for canine hemangiosarcoma?

A

Doxorubicin.

57
Q

What are the diagnostic imaging techniques used for evaluating splenic neoplasia in dogs and cats?

A

The diagnostic imaging techniques used for evaluating splenic neoplasia in dogs and cats are radiography and ultrasonography.

58
Q

Where is the spleen located in dogs and cats?

A

In dogs, the spleen is located in the left cranial quadrant caudolateral to the gastric fundus and craniolateral to the left kidney. In cats, splenic neoplasia is more commonly generalized.

59
Q

How does splenic neoplasia appear on radiography?

A

On radiography, splenic neoplasia appears as large masses that often appear in the midabdomen on ventrodorsal and lateral views.

60
Q

What abnormalities can be detected using ultrasonography for evaluating the spleen?

A

Using ultrasonography, focal enlargement, disruption, trauma, hematoma, and some neoplastic lesions can be detected in the spleen. Additionally, changes in parenchyma echotexture and vascularity can be evaluated.

61
Q

How can contrast-enhanced ultrasonography improve the characterization of focal and multifocal lesions in feline and canine spleens?

A

Contrast-enhanced ultrasonography allows the comparison of perfusion of focal lesions with surrounding parenchyma, improving the characterization of such lesions in feline and canine spleens.

62
Q

What are the advantages and limitations of using contrast-enhanced ultrasonography for splenic disease evaluation?

A

Contrast-enhanced ultrasonography is portable, rapidly performed, and less expensive than CT or MRI. However, there is limited published experience in veterinary patients regarding its full use.

63
Q

What is the term used to describe the failure of the spleen to develop in utero in dogs and cats?

A

Asplenia

64
Q

What is the term used to describe small fragments with a normal splenic architecture found on histopathologic examination?

A

Accessory spleen

65
Q

What is the more appropriate term for the survival of splenic tissue after trauma?

A

Splenosis

66
Q

Where can congenital accessory spleens be found in all species?

A

Throughout the body, including the thoracic cavity, inguinal canal, and scrotum.

67
Q

What is the most common site of accessory spleens in dogs?

A

Within the gastrosplenic ligament.

68
Q

How can splenic fissures be differentiated from healed lacerations in dogs?

A

By the normal appearance of the capsule and smooth surface within the fissure.

69
Q

What are the critical functions of the spleen?

A

Filtering microorganisms and antigenic particles, synthesis of immunoglobulin G and complement pathway cytokines, maturation of newly formed erythrocytes, storage of RBCs and platelets, and removal of abnormal and senescent RBCs.

70
Q

During fetal development, what is the major site of extramedullary hematopoiesis in the spleen?

A

The splenic red pulp.

71
Q

What is the rate of concurrent right atrial mass in dogs presenting with splenic hemangiosarcoma?

A

8.7% (2 of 23 dogs)

72
Q

What is the rate of concurrent splenic hemangiosarcoma in dogs presenting with a right atrial hemangiosarcoma?

A

29% (9 of 31 dogs)

73
Q

What imaging technique was used to evaluate contrast-enhanced CT of splenic lesions?

A

Computed Tomography

74
Q

What were the findings of the recent prospective study on contrast-enhanced CT of splenic lesions?

A

Splenic hemangiosarcoma had significantly lower density (lower Hounsfield units) than nodular hyperplasia or hematomas on precontrast and postcontrast images.

75
Q

How many dogs were accurately differentiated for benign and malignant lesions using MRI?

A

Eight of eight dogs

76
Q

What was the diagnostic utility of samples collected by fine needle aspiration or needle biopsy in one study?

A

Hematopoietic neoplasia was accurately diagnosed in 100% and nonhemic malignancy in 2 of 3 animals.

77
Q

What is the chance of successful diagnosis for hematopoietic hyperplasia and neoplasia?

A

The chance of successful diagnosis is good due to ready cellular exfoliation of these lesions and the use of Romanowsky stains facilitates identification of cells of hemic origin.

78
Q

What evaluations are recommended in animals with splenic disease before anesthetic induction?

A

A coagulation profile, blood typing, serum chemistry study results, and a complete blood count.

79
Q

What is the role of the spleen in fetal immune development?

A

The spleen provides the basis for fetal immune development.

80
Q

What types of cells does the spleen produce in dogs and cats?

A

The spleen produces B-cells, T-cells, and IgM in dogs and cats.

81
Q

How does the spleen filter microorganisms from the blood?

A

The spleen filters microorganisms from the blood via phagocytosis.

82
Q

Where does antigen uptake occur in the spleen?

A

Antigen uptake occurs in the marginal zone and sinusoids of the red pulp.

83
Q

What is lymphocyte trapping and how does it enhance immune response?

A

Lymphocyte trapping is the inhibition of egress by circulating lymphocytes in the spleen, which increases the number of lymphocytes at the site of antigen accumulation and maximizes immune response.

84
Q

What is the primary site of antibody production in the spleen?

A

The red pulp and marginal zone are the primary sites of antibody production in the spleen.

85
Q

Apart from antibody production, how does the spleen contribute to early immune defense?

A

The spleen produces IgM in response to antigen and also improves neutrophil phagocytosis and activates the complement pathway.

86
Q

What is the role of the spleen in removing IgG covered erythrocytes and platelets?

A

The spleen filters and removes IgG covered erythrocytes and platelets, especially in diseases like immune-mediated thrombocytopenia and immune-mediated hemolytic anemia.

87
Q

What is the approximate weight of the spleen in dogs and cats?

A

Approximately 0.2% of the body weight.

88
Q

What ligament tethers the spleen to the greater curvature of the stomach?

A

The wide gastrosplenic ligament.

89
Q

Where does the larger ventral extremity of the spleen generally lie?

A

Across the ventral midline just caudal to the ribs.

90
Q

What color does the spleen appear when it is entirely under the rib cage and in a state of contraction?

A

Pale blue to purple.

91
Q

What is the splenic vascular supply derived from?

A

The celiac artery.

92
Q

What does the splenic artery run the length of?

A

The left limb of the pancreas.

93
Q

Where does the splenic vein drain into?

A

The gastrosplenic vein before entering the portal vein.

94
Q

What is the spleen composed of?

A

Red and white pulp surrounded by a capsule and traversed by a complex network of trabeculae.

95
Q

What is the median survival time of dogs on etoposide protocols?

A

178 days

96
Q

What is the median survival time of dogs on doxorubicin protocols?

A

133 days

97
Q

In combination with doxorubicin, which selective COX-2 inhibitor has been examined with early success in 21 dogs?

A

Deracoxib

98
Q

What is the median survival time for dogs with nonangiogenic and nonlymphomatous sarcomas?

A

2.5 months

99
Q

For dogs with an obvious metastatic lesion at surgery, what is the median survival time?

A

1 month

100
Q

What is the prognosis for cats with splenic mast cell tumor?

A

Guarded / Survival ranges from 2 to 34 months after splenectomy

101
Q

In a retrospective study of dogs with and without clinical disease, what were the most common causes of localized splenomegaly?

A

Splenic hematoma and reactive hyperplasia

102
Q

What is the main complication associated with complete splenectomy for splenic hematomas?

A

Hemorrhage