A Pilot Study to Explore the Use of Skin Biopsy as Diagnostic Tool in Anterior Cutaneous Nerve Entrapment Syndrome (ACNES) (Biopsy-ACNES)

Skin Biopsy as Diagnostic Tool in Anterior Cutaneous Nerve Entrapment Syndrome (ACNES): A Pilot Study

ACNES is a neuropathic pain condition of the abdominal wall. It is a clinical diagnosis based on patient's history and physical examination. No diagnostic test is available to confirm the diagnosis.

This pilot study will determine if skin biopsies can be used as diagnostic test. Two 3mm biopsies will be taken and used to count the small nerve fibres in the skin. The number of small nerve fibres of the painful skin will be compared to non-painful skin. Skin biopsy and small fibre nerve count is already used as diagnostic test in patients with small-fibre neuropathy.

The investigators hypothesize that patients with ACNES will have a reduced number of small nerve fibres in the affected skin, compared to the non-affected skin.

Study Overview

• Status: Recruiting
• Conditions: Chronic Pain Syndrome; Diagnosis; Nerve Entrapment Syndrome; Anterior Cutaneous Nerve Entrapment Syndrome
• Intervention / Treatment: Procedure: Skin biopsy

• Study Type: Interventional
• Enrollment (Estimated): 12
• Phase: Not Applicable

Contacts and Locations

• Study Contact: Name: Tom ten Have, MD; Phone Number: +31408887461; Email: Tom.ten.Have@mmc.nl

Study Locations

• Netherlands
  • Veldhoven, Netherlands, 5504 DB
    • Recruiting
    • Maxima Medical Center
    • Contact: Tom ten Have, MD; Phone Number: +31408887461; Email: Tom.ten.Have@mmc.nl
    • Principal Investigator: Rudi Roumen, MD, PhD

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: 21 years to 40 years (Adult)
• Accepts Healthy Volunteers: No

Description

Inclusion Criteria:

• Duration of pain >3 months
• Newly diagnosed unilateral ACNES
• Fully completed intake questionnaire
• Obtained written informed consent

Exclusion Criteria:

• Inability to understand Dutch language
• Bilateral ACNES
• Previously administered injections with corticosteroids at trigger point (injection with a local anaesthetic is allowed)
• Previous Pulsed Radiofrequency (PRF)-treatment at trigger point
• History of open abdominal surgery
• History of neurectomy
• Known neuromuscular or neurodegenerative disease
• Antiplatelet or anticoagulants use or known coagulation disorders

• Disorder known to cause a reduced IENFD;

  • Diabetes
  • Hypothyroidism
  • Renal failure
  • Vitamin B12 deficiency
  • Monoclonal gammopathy
  • Alcohol abuse (>5 IU a day)
  • Malignancies
  • Medication that cause neuropathy (for example chemotherapy)

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Diagnostic
• 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: Patients with unilateral ACNES	Procedure: Skin biopsy; Two 3mm skin biopsies from the abdominal wall will be taken. One at the triggerpoint of the pain, the second one at the contralateral, non-affected side of the abdominal wall. Lidocaine will be used for local anaesthesia of the skin, before the biopsies will be taken.

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Intraepidermal Nerve Fibre density (IENFD)	Difference in IENFD (measured in IENF/mm) from both affected and non-affected side of the abdominal wall.	Both biopsies will be taken at the same time, as their difference will be studied. The biopsies will be taken at the second outpatient visit, 2 or 3 weeks after the first visit, just after the second triggger point injection (standard of care).

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Pain score	Average pain score, assessed using the Numeric Rating Scale (NRS) 0-10 before start of treatment. 0 no pain, 10 worst possible pain.	Assessed at first outpatient visit, used as baseline data.
Duration of pain	Duration of pain in months before diagnosis	Assessed at first outpatient visit, used as baseline data.
Treatment response	Patients will receive standard of care treatment for ACNES. Treatment is unsuccessful if <50% pain reduction or when patients are not satisfied with their pain relief and want additional treatment.	Treatment response will be assessed 2 to 6 weeks after each treatment (trigger point injections, PRF and neurectomy), as standard of care.

Collaborators and Investigators

• Sponsor: Maxima Medical Center
• Investigators: Principal Investigator: Rudi Roumen, MD, PhD, Maxima Medical Center

Study record dates

Study Major Dates

• Study Start (Actual): May 24, 2023
• Primary Completion (Estimated): November 1, 2023
• Study Completion (Estimated): December 1, 2023

Study Registration Dates

• First Submitted: December 29, 2022
• First Submitted That Met QC Criteria: January 9, 2023
• First Posted (Actual): January 10, 2023

Study Record Updates

• Last Update Posted (Actual): May 31, 2023
• Last Update Submitted That Met QC Criteria: May 26, 2023
• Last Verified: May 1, 2023

More Information

Terms related to this study

• Keywords: Diagnostic test for ACNES; Intraepidermal nerve fibre density (IENFD)
• Additional Relevant MeSH Terms: Pathologic Processes; Nervous System Diseases; Pain; Neurologic Manifestations; Disease; Congenital Abnormalities; Genetic Diseases, Inborn; Neuromuscular Diseases; Neurodegenerative Diseases; Peripheral Nervous System Diseases; Heredodegenerative Disorders, Nervous System; Nervous System Malformations; Polyneuropathies; Syndrome; Chronic Pain; Nerve Compression Syndromes; Charcot-Marie-Tooth Disease; Hereditary Sensory and Motor Neuropathy
• Other Study ID Numbers: NL81661.015.22

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: UNDECIDED

Drug and device information, study documents

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