Ultrasound Guided Microwave Ablation of Splenomegaly in Children

Not Applicable

Recruiting

Conditions: Splenomegaly; Congestive, Chronic
Panhematopenia; Splenic
Portal Hypertension

Brief Summary: Children with liver cirrhosis frequently develops portal hypertension. One of the serious complications to portal hypertension is splenomegaly, which may result in pancytopenia, especially thrombocytopenia that may cause bleeding tendencies.

Symptomatic splenomegaly is often treated with partial splenic embolization (PSE). PSE is effective but may give rise to postembolization syndrome not well tolerated in the pediatric population. In adults, microwave ablation (MWA) has been used to treat splenomegaly with promising results but with less post-operative pain. Our study is a pilot trial to evaluate the feasibility and acceptability of this treatment in children.

Detailed Description: The ablation will be performed under general anesthesia by an experienced interventional radiologist. Ultrasound will be used for peri-operative assessment and the microwave antenna will be inserted under ultrasound guidance focusing on the middle to inferior part of the spleen to avoid harm to the diaphragm. After the emission of microwaves for up to 5 minutes, the antenna will be pulled back and the emission will be repeated until the ablation zone is approximately 1 cm from the splenic surface. In this way, two or three overlapping areas will be ablated with every insertion of the antenna. The ablation zones will be visible as hyperechoic areas on b-mode ultrasound during operation, and the goal is to ablate up to 40-50% of the total volume of the spleen (as estimated by the radiologist). If the ablated volume is less than 40-50% at follow up, the procedure can be repeated in a second session for additional effect.

Recruitment & Eligibility

Inclusion Criteria

Spleen length > +2 standard deviations of normal limit
Platelet count below 30-35 x 109 cells/L and a history of bleeding tendencies
Symptoms of portal hypertension such as splenomegaly, thrombocytopenia, leucopenia, ascites, esophageal or gastric varices, hypertensive gastropathy, anal hemorrhoids and increased portal scintigraphy index, where alternative methods have not been enough or suitable
A necessity for reduction of splenic volume due to splenic inhibition of motion and activity in the child

Exclusion Criteria

Arm && Interventions

Group	Intervention	Description
Microwave ablation	Microwave ablation	Patients receiving microwave ablation of splenomegaly

Primary Outcome Measures

Name	Time	Method
Platelet count	Base line and 1, 3, 6 and 12 months follow up	Difference between platelet count before MWA and at 1, 3, 6 and 12 months after treatment

Secondary Outcome Measures

Name	Time	Method
Effect on blood cell count	Base line and 1, 3, 6 and 12 months follow up	Effect on red and white blood cell count
Acceptability of treatment	1 month after ablation	Measured as parents preferred future treatment and as if the method could be recommended to a family with a child with a similar medical condition
Number of MWA	Within 12 months	Number of MWA to achieve goal with platelet count \> 50 x 109 cells/L or reducing functional spleen with 50%
Effect on liver function	Base line and 1, 3, 6 and 12 months follow up	Measurement of AST, ALT, ALP, GGT, bilirubin, cholinesterase, albumin, ammonia
Effect on coagulation	Base line and 1, 3, 6 and 12 months follow up	Measurement of PT-INR, APTT, D-dimer, fibrinogen, ROTEM with fibrinogen, antithrombin, von Willebrand activity (vWGP1bA), factor VIII enzyme
Maximal pain	Day of surgury and the following 7 days	Measured using the Visual Analog Scale, a numerical rating scale from 0 - 10 where 0 is no pain and 10 is worst imaginable pain.
Use of analgesic drugs	Day of surgury and the following 7 days	The administration of standardized analgesic drugs will be recorded
Days of hospitalization	1 month	How many days the patient stays in hospital after ablation