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

Not Applicable

Recruiting

• Conditions: Nerve Entrapment Syndrome; Anterior Cutaneous Nerve Entrapment Syndrome; Chronic Pain Syndrome; Diagnosis
• Interventions: Procedure: Skin biopsy

• Registration Number: NCT05678127
• Lead Sponsor: Maxima Medical Center

Brief Summary

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.

Detailed Description

Not available

Study Timeline

• Study First Submitted: 2022-12-29
• Study First Submitted QC: 2023-01-09
• Study First Posted: 2023-01-10
• Status Verified: 2023-05
• Study Start: 2023-05-24
• Last Update Submitted: 2023-05-26
• Last Update Posted: 2023-05-31
• Primary Completion: 2023-11
• Study Completion: 2023-12

Recruitment & Eligibility

• Status: RECRUITING
• Sex: All
• Target Recruitment: 12

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 & Design

• Study Type: INTERVENTIONAL
• Study Design: SINGLE_GROUP

Arm && Interventions

Group	Intervention	Description
Patients with unilateral ACNES	Skin biopsy	-

Primary Outcome Measures

Name	Time	Method
Intraepidermal Nerve Fibre density (IENFD)	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).	Difference in IENFD (measured in IENF/mm) from both affected and non-affected side of the abdominal wall.

Secondary Outcome Measures

Name	Time	Method
Treatment response	Treatment response will be assessed 2 to 6 weeks after each treatment (trigger point injections, PRF and neurectomy), as standard of care.	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.
Pain score	Assessed at first outpatient visit, used as baseline data.	Average pain score, assessed using the Numeric Rating Scale (NRS) 0-10 before start of treatment. 0 no pain, 10 worst possible pain.
Duration of pain	Assessed at first outpatient visit, used as baseline data.	Duration of pain in months before diagnosis

Trial Locations

Locations (1)

Maxima Medical Center; 🇳🇱 Veldhoven, Netherlands