Ultrasound Guided Microwave Ablation of Splenomegaly in Children

Portal Hypertension Clinical Trial

Official title:

Ultrasound Guided Partial Microwave Ablation of the Spleen Due to Secondary Splenomegaly in Children - a Study of Feasibility and Acceptability

Clinical Trial Details — Status: Recruiting

Administrative data

• NCT number: NCT05050994
• Other study ID #: 2020-06155
• Status: Recruiting
• Phase: N/A
• Start date: March 1, 2021
• Est. completion date: February 1, 2025

Study information

• Verified date: September 2021
• Source: Karolinska Institutet
• Contact: Thomas Casswall, MD, PhD
• Phone: +46 8 58581464
• Email: thomas.casswall[@]ki.se
• Is FDA regulated: No
• Study type: Interventional

Clinical Trial 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.

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 information / eligibility

• Status: Recruiting
• Enrollment: 10
• Est. completion date: February 1, 2025
• Est. primary completion date: March 1, 2024
• Accepts healthy volunteers: No
• Gender: All
• Age group: 10 Years to 17 Years

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:

• Age younger than 10 or older than 17 years of age

• Legal guardians or child do not give consent

• Ongoing infection

Related Conditions & MeSH terms

• Hypertension, Portal
• Portal Hypertension
• Splenomegaly

Intervention

Procedure:
• Microwave ablation
Children with symptomatic secondary splenomegaly will receive partial microwave ablation of spleen (up to 40-50% of total volume)

Locations

Country	Name	City	State
Sweden	Karolinska University Hospital	Stockholm

Sponsors (1)

Lead Sponsor	Collaborator
Karolinska Institutet

Country where clinical trial is conducted

Sweden, 

Outcome

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