Ultrasound Guided Microwave Ablation of Splenomegaly in Children

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

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.

Study Overview

• Status: Recruiting
• Conditions: Portal Hypertension; Splenomegaly; Congestive, Chronic; Panhematopenia; Splenic
• Intervention / Treatment: Procedure: Microwave ablation

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.

• Study Type: Interventional
• Enrollment (Anticipated): 10
• Phase: Not Applicable

Contacts and Locations

• Study Contact: Name: Thomas Casswall, MD, PhD; Phone Number: +46 8 58581464; Email: thomas.casswall@ki.se
• Study Contact Backup: Name: Marie Beermann, MD.; Phone Number: +46 8 12357843; Email: marie.beermann@ki.se

Study Locations

• Sweden
  • Stockholm, Sweden, 17177
    • Recruiting
    • Karolinska University Hospital
    • Contact: Thomas Casswall, MD. PhD.

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: 10 years to 17 years (Child)
• Accepts Healthy Volunteers: No
• Genders Eligible for Study: All

Description

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

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Treatment
• Allocation: N/A
• Interventional Model: Single Group Assignment
• Masking: None (Open Label)

Number of Arms

1

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Experimental: Microwave ablation; Patients receiving microwave ablation of splenomegaly	Procedure: Microwave ablation; Children with symptomatic secondary splenomegaly will receive partial microwave ablation of spleen (up to 40-50% of total volume)

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
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 Outcome Measures

Outcome Measure	Measure Description	Time Frame
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
Effect on blood cell count	Effect on red and white blood cell count	Base line and 1, 3, 6 and 12 months follow up
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
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
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
Use of analgesic drugs	The administration of standardized analgesic drugs will be recorded	Day of surgury and the following 7 days
Days of hospitalization	How many days the patient stays in hospital after ablation	1 month
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

Collaborators and Investigators

• Sponsor: Karolinska Institutet
• Investigators: Principal Investigator: Thomas Casswell, MD, PhD, Karolinska Institutet

Study record dates

Study Major Dates

• Study Start (Actual): March 1, 2021
• Primary Completion (Anticipated): March 1, 2024
• Study Completion (Anticipated): February 1, 2025

Study Registration Dates

• First Submitted: September 10, 2021
• First Submitted That Met QC Criteria: September 10, 2021
• First Posted (Actual): September 21, 2021

Study Record Updates

• Last Update Posted (Actual): January 4, 2022
• Last Update Submitted That Met QC Criteria: December 30, 2021
• Last Verified: September 1, 2021

More Information

Terms related to this study

• Keywords: Microwave ablation
• Additional Relevant MeSH Terms: Digestive System Diseases; Liver Diseases; Pathological Conditions, Anatomical; Hypertrophy; Hypertension, Portal; Splenomegaly
• Other Study ID Numbers: 2020-06155

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No