Does Re-surgery Improve Somatosensory Outcomes in Persistent Pain After Groin Hernia Repair

November 21, 2022 updated by: mads u werner

Somatosensory Outcomes Following Re-surgery in Persistent Severe Pain After Groin Hernia Repair

Groin hernia repair is accompanied by persistent severe pain in 2-4% of the patients significantly restraining psychophysical functions. Re-surgery with meshectomy and selective neurectomy may improve the pain condition, compared to non-surgical alternatives. In the current study, the primary objective was to examine and describe the underlying pathophysiological perturbations by quantitative somatosensory testing before and after re-surgery.

Study Overview

Detailed Description

Persistent severe pain occurring in the aftermath of a surgical procedure is frequently associated with significant impairment of physical and psycho-social functions. After groin hernia repair (GHR), 2-4% of patients develop persistent severe pain. The GHR procedure, previously considered belonging to "minor" surgeries, qualifies as a rather complex procedure performed in a territory with a high density of nerve fibers, accommodating essential functions for locomotion and reproduction. More than 20 million repairs are performed annually worldwide, and consequently, it is estimated that 400.000-800.000 patients each year will develop persistent severe pain after the groin hernia repair (PSPG). Management of PSPG is medically challenging and may require re-surgery with mesh removal and selective neurectomy. After re-surgery for pain after open primary GHR, a potential pain-relieving effect, as well as an improvement of the deteriorated physical functions, has been demonstrated.

Quantitative somatosensory testing (QST) is an investigational psychophysiological tool with the potential to uncover the putative pathophysiological substrate in PSPG, i.e., neuropathic and inflammatory constituents. The method may also be used to quantitate changes induced by the re-surgery. Since re-surgery is a neuroablative procedure, essentially performed in previously damaged tissue, it is of interest to examine the extent of neurological perturbations, i.e., 'loss' and 'gain' of sensory functions and the relation to clinical outcome measures.

The authors are only aware of one previous PSPG-study (n = 21) finding that re-surgery, including meshectomy and selective neurectomy, was associated with increased pain pressure thresholds, decreased pain ratings and improved pain-related functional measures. The objectives of the current study, comparing pre with post-re-surgery data, were first to perform a more detailed analysis of the quantitative somatosensory data regarding 'loss' and 'gain' of sensory functions and their relation to clinical outcome measures. Second, to corroborate the clinical outcome findings of the previous study using a threefold larger cohort.

Study Type

Observational

Enrollment (Actual)

60

Contacts and Locations

This section provides the contact details for those conducting the study, and information on where this study is being conducted.

Study Locations

      • Copenhagen, Denmark, 2100
        • Multidisciplinary Pain Center, Neuroscience Center, Copenhagen University Hospital, DENMARK

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

Eligibility Criteria

Ages Eligible for Study

18 years and older (Adult, Older Adult)

Accepts Healthy Volunteers

No

Genders Eligible for Study

All

Sampling Method

Non-Probability Sample

Study Population

Patients with persistent severe pain after groin hernia repair.

Description

Inclusion Criteria:

  • Patients with persistent severe pain (activity-related or maximal pain intensity > 7 NRS-scores [numeric pain rating scale 0-10]) following unilateral, uncomplicated, open groin hernia repair.

Exclusion Criteria:

  • All that contradicts the above.

Study Plan

This section provides details of the study plan, including how the study is designed and what the study is measuring.

How is the study designed?

Design Details

  • Observational Models: Cohort
  • Time Perspectives: Prospective

What is the study measuring?

Primary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Thermal thresholds
Time Frame: 3-6 months
Warmth detection threshold (WDT), cool detection threshold, heat pain threshold (HPT) and cold pain threshold (CPT) are made by a computerized contact thermode (Thermotest, Somedic AB, Sweden) with an active thermal surface of 12.5 cm^2 (2.5 x 5.0 cm^2). The thresholds are determined from a baseline temperature of 32°C with a ramp rate of + 1°C/s. Cut-offs for heat and cold are 50°C and 5°C, respectively. The assessments are made in triplicate and the mean values are used in the statistical analyses.
3-6 months
Pressure algometry
Time Frame: 3-6 months
Deep-tissue pain sensitivity is assessed using a hand-held pressure algometer with a neoprene-coated tip of area 1.0 cm2 (Somedic AB, Sweden), as previously described. The algometer is applied perpendicularly to the skin with a pressure rate of 30 kPa/s. The study subject is told to report the pressure pain threshold (PPT) by activating the button device when pain is perceived. The cut-off limit is 350 kPa. Testing is done in triplicate and the average value is used in the statistical analyses.
3-6 months
Suprathreshold heat stimulation
Time Frame: 3-6 months
A short tonic heat stimulus (heating area 12.5 cm^2; ramp rate: 1°C/s, plateau: 47°C, 5 s; STH) is delivered in order to evaluate the suprathreshold heat pain perception (NRS).
3-6 months
Temporal summation
Time Frame: 3-6 months
Temporal summation test, i.e., the perception in response to repetitive (0.3 to 3 Hz) mechanical stimulation [i.e., wind-up like pain: WUP], indicates presence of central sensitization. The repetitive 1 Hz stimuli for 60 s are either dynamically delivered by a brush or statically delivered by a polyamide filament (one nominal rank below TPT). The study subjects are told to report the level of pain (NRS) every 15 s-1 during the stimulation. Signs of aftersensations are followed 60 s after discontinuation of the stimulation, and the intensity of discomfort or pain is rated by NRS.
3-6 months

Secondary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Activity Assessment Scale (AAS)
Time Frame: 3-6 months
Changes in AAS scores before and thre-six months after operation
3-6 months
Pain intensity scores (NRS)
Time Frame: 3-6 months
Changes in pain intensity scores (NRS) at rest, on average and maximally before and thre-six months after operation
3-6 months

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Sponsor

Publications and helpful links

The person responsible for entering information about the study voluntarily provides these publications. These may be about anything related to the study.

General Publications

Study record dates

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

Study Major Dates

Study Start (Actual)

April 24, 2009

Primary Completion (Actual)

March 19, 2015

Study Completion (Actual)

March 19, 2015

Study Registration Dates

First Submitted

February 3, 2022

First Submitted That Met QC Criteria

February 3, 2022

First Posted (Actual)

February 14, 2022

Study Record Updates

Last Update Posted (Actual)

November 28, 2022

Last Update Submitted That Met QC Criteria

November 21, 2022

Last Verified

November 1, 2022

More Information

Terms related to this study

Plan for Individual participant data (IPD)

Plan to Share Individual Participant Data (IPD)?

Yes

IPD Plan Description

Data will be made available as a supplement to the published scientific article.

Drug and device information, study documents

Studies a U.S. FDA-regulated drug product

No

Studies a U.S. FDA-regulated device product

No

product manufactured in and exported from the U.S.

No

This information was retrieved directly from the website clinicaltrials.gov without any changes. If you have any requests to change, remove or update your study details, please contact register@clinicaltrials.gov. As soon as a change is implemented on clinicaltrials.gov, this will be updated automatically on our website as well.

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