What is the success rate of splenectomy for treating Immune-mediated Thrombocytopenia (ITP) in cats?

Success Rate of Splenectomy for Immune-mediated Thrombocytopenia (ITP) in Cats

Splenectomy for feline ITP has limited documented success, with evidence suggesting a poor response to treatment and frequent relapses, unlike the 80% initial response rate seen in humans.

Efficacy of Splenectomy in Feline ITP

• Feline primary immune-mediated thrombocytopenia (pIMT) is a rare hematological disorder that often responds poorly to conventional therapy with prednisolone 1
• Unlike in humans where 80% respond to splenectomy with sustained response in 66% for at least 5 years, cats with ITP appear to have a more chronic course with frequent relapses 2, 1
• Limited case reports suggest that splenectomy may be one component of a multimodal treatment approach for refractory feline ITP, but is not consistently effective as a standalone therapy 3

Surgical Considerations for Feline Splenectomy

• Laparoscopic splenectomy techniques have been developed for cats, potentially offering a safer alternative to traditional celiotomy 4
• In a small case series, three cats undergoing laparoscopic splenectomy for various splenic diseases recovered well and were discharged the day after surgery 4
• However, technical feasibility does not necessarily correlate with therapeutic efficacy for immune-mediated conditions 4

Treatment Challenges in Feline ITP

• Cats with ITP often experience a chronic disease course with poor response to conventional therapy and frequent relapses 1
• Long-term corticosteroid use in cats with ITP can lead to significant complications, including diabetes mellitus 1
• In one documented case of feline ITP, multiple treatments including glucocorticoids, chlorambucil, romiplostim, splenectomy, and mycophenolate mofetil were required to achieve disease control 3

Alternative Treatments for Feline ITP

• Thrombopoietin receptor agonists (TPO-RAs) like romiplostim have been used in individual cases of feline ITP with variable efficacy 3
• Romiplostim may help manage life-threatening thrombocytopenia while pursuing other treatment options 3
• Alternative immunomodulatory drugs should be considered in cats with ITP that responds poorly to corticosteroids 1

Comparison to Human ITP Treatment

• In humans, splenectomy provides an 80% initial response rate with sustained response in 66% of patients for at least 5 years 2
• However, up to 30% of human responders will relapse during the 10 years following splenectomy, typically within 2 years 2
• The advent of pharmaceutical second-line treatments like TPO-receptor agonists and rituximab has significantly decreased the use of splenectomy in human ITP 2

Practical Considerations

• Diagnosis of feline pIMT is challenging and requires exclusion of other identifiable causes of thrombocytopenia 1
• The chronic nature and poor response to therapy seen in feline ITP cases suggests that splenectomy should be considered only after failure of medical management 3, 1
• When splenectomy is performed in cats, laparoscopic techniques may offer advantages of reduced recovery time and complications 4

Risks and Complications

• In humans, splenectomy carries risks of infection, thromboembolism, and possibly increased incidence of malignancy 2
• Surgical complications were reported in 10% of human patients in the 30-day period following splenectomy, even with laparoscopic methods 2
• Similar risks likely apply to feline patients, though specific data on post-splenectomy complications in cats with ITP is limited 4