Treatment of Infective Endocarditis with Splenic Abscess
Initiate appropriate antibiotic therapy immediately and perform splenectomy (or percutaneous drainage if the patient is a high-risk surgical candidate) before cardiac valve surgery unless the cardiac surgery is urgent. 1
Initial Management
Start appropriate antibiotic regimens targeting the causative organism immediately upon diagnosis. 1 Viridans streptococci and S. aureus each account for 40% of splenic abscess cases in infective endocarditis, with enterococci responsible for 15%. 1
Obtain abdominal CT or MRI to confirm the diagnosis, as both have sensitivities and specificities of 90-95% for detecting splenic abscess. 1, 2, 3 On CT, splenic abscesses appear as single or multiple contrast-enhancing cystic lesions, while bland infarcts show peripheral low-density, wedge-shaped areas. 1, 3
Monitor for clinical indicators of abscess versus bland infarction: persistent or recurrent fever, ongoing abdominal pain, recurrent bacteremia, and persistence or enlargement of splenic defects on imaging suggest abscess formation rather than uncomplicated infarction. 1, 3
Definitive Treatment Strategy
The timing and sequence of interventions depends on cardiac urgency:
When Cardiac Surgery is NOT Urgent
Perform splenectomy before valve replacement surgery to prevent reinfection of the valve prosthesis from bacteremia originating from the splenic abscess. 1, 3, 4, 5, 6
Splenectomy is the definitive treatment because splenic abscesses respond poorly to antibiotics alone. 1
When Cardiac Surgery IS Urgent
Proceed with urgent valve replacement first, then perform splenectomy afterward through a separate incision if needed. 1, 5
Rarely, both procedures can be performed simultaneously during the same operative session through the same median sternotomy incision if the abscess is localized within the spleen. 5, 6
Alternative for High-Risk Surgical Candidates
Percutaneous catheter drainage (PCD) is an alternative to splenectomy for patients who are poor surgical candidates. 1, 2
Use CT or ultrasound guidance for precise catheter placement, targeting single large abscesses where a safe drainage window exists. 2
Continue drainage until resolution is confirmed: remove the catheter only when signs of infection resolve, output is <10-20cc daily, and repeat imaging shows abscess resolution. 2
Be aware that PCD failure rates range from 14.3% to 75%, so close monitoring for treatment failure is essential. 2
Critical Pitfalls to Avoid
Do not rely on antibiotics alone for large splenic abscesses, as this approach has high failure rates and can be fatal. 1, 2, 7 While one case report describes successful conservative management with antibiotics alone 8, this represents an exceptional circumstance and contradicts guideline recommendations.
Do not delay splenectomy when indicated, as splenic tissue becomes extremely fragile with abscess formation, and minimal trauma can cause rupture with massive hemorrhage. 6
Do not perform valve replacement before addressing the splenic abscess unless cardiac surgery is truly urgent, as this risks reinfection of the prosthetic valve. 1, 3, 4, 6