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NCT Number: NCT06647290

ENVELOP: Wound Care Following Pilonidal Sinus Surgery

This is a single-blinded, multicentre, prospective randomised controlled trial (RCT) comparing post-operative and patient-reported outcomes for patients undergoing application of negative-pressure wound therapy (NPWT) after sinus tract excision as compared to excision and standard open wound care in chronic pilonidal sinus disease (PSD).

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Key information

Conditions

Pilonidal Sinus Cysts Infections Neoplasms Pathologic Processes Pathological Conditions, Signs and Symptoms Postoperative Complications Surgical Wound Infection Wound Healing Wound Infection

Age range

18 year and older

Sex eligibility

All sexes

Study type

Interventional

Phase

Not applicable

Primary location

Beaumont Hospital, Dublin, Ireland

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About this study

Pilonidal sinus disease (PSD) is a chronic inflammatory condition of the skin and subcutaneous tissues arising from hair follicles in the natal cleft. The definitive aetiology of the condition is unknown, however, it is theorised that it is the result of either the obstruction and subsequent inflammation of hair follicles or secondary to hair penetrating through the skin into the subcutaneous tissue. This results in infection, abscess formation, chronic discharge and pain. PSD is a common condition affecting 26 per 10,000 population, with the prevalence reaching 1.1% in young adult males.

PSD causes a significant burden on healthcare services due to high rates of recurrence and readmission following surgery, together with negative impacts on patients' quality of life and self-image. An effective management strategy for the disease is necessary to ensure that post-operative outcomes are optimised and patient-reported outcomes are satisfactory in those whose PSD requires surgery.

The objective of this multicentre, national RCT is to prospectively investigate the effect of negative pressure wound therapy compared to leaving open with standard wound care on time to wound healing following surgical excision of chronic PSD.

Who can participate

Healthy volunteers accepted: No

Only the study team can determine whether someone qualifies for participation.

Inclusion criteria

i) They are aged 18 years or older

ii) They are undergoing elective pilonidal sinus excision without primary closure

Exclusion criteria

i) They are unable to adhere to protocol requirements e.g. questionnaire completion

ii) They are undergoing emergency drainage for a pilonidal abscess

iii) They are undergoing surgery for a pilonidal sinus disease in locations other than the natal cleft

iv) They have underlying osteomyelitis

v) They have underlying fistulating disease e.g. Crohn's

Treatment and study plan

Negative pressure wound therapy

Device

Application of a negative wound pressure therapy dressing to the wound post laparotomy

Primary outcomes

  1. Time to complete wound healing

    Time frame: 6 months post surgery

    Number of days to complete epithelialisation or closure of the wound without any discharge, drainage, scab, and/or the requirement for further dressing. The quality of wound healing will be assessed using a validated patient and observer reported scar assessment tool-POSAS.

Secondary outcomes

  1. Measure of post operative pain

    Time frame: 6 months post surgery

    Pain measured by visual analogue pain scores which is a scale from 1 (no pain) to 10 (worst pain), between the NPWT and SWC Groups.

  2. Measure of post operative complications

    Time frame: 6 months post surgery

    Measure of post operative complications between the NPWT and SWC Groups

  3. Measure of quality of life

    Time frame: 6 months post surgery

    To compare quality-of-life differences between the two groups from the time of surgery until wound healing is achieved using the

  4. To investigate resource use

    Time frame: 6 months post surgery

    To investigate resource use and thereby cost effectiveness of NPWT versus standard wound care

  5. To compare recurrence rates

    Time frame: 6 months post surgery

    To compare the 6-month recurrence rates (recurrence being defined as the development of a new sinus or abscess within the natal cleft occurring after wound healing had been achieved) between the NPWT and SWC Groups

  6. Health-related quality of life with the EuroQol-5 dimensions five level index questionnaire (EQ-5D-5L)

    Time frame: 1 month

    The questionnaire covers five dimensions of health: mobility, self-care, usual activities, pain or discomfort, and anxiety or depression. Each dimension has 5 levels: no problems (1), slight problems (2), moderate problems (3), severe problems (4) and extreme problems (5). The patient is asked to indicate his/her health state by ticking the box next to the most appropriate statement in each of the five dimensions. The raw scores are also converted to an EQ-5D index value using a scoring algorithm (British tariff) ranging from -0.594 (worst perceived health state) to 1.00 (best perceived health state)

  7. Health-related quality of life with the EuroQol-5 dimensions five level index questionnaire (EQ-5D-5L)

    Time frame: 3 months

    The questionnaire covers five dimensions of health: mobility, self-care, usual activities, pain or discomfort, and anxiety or depression. Each dimension has 5 levels: no problems (1), slight problems (2), moderate problems (3), severe problems (4) and extreme problems (5). The patient is asked to indicate his/her health state by ticking the box next to the most appropriate statement in each of the five dimensions. The raw scores are also converted to an EQ-5D index value using a scoring algorithm (British tariff) ranging from -0.594 (worst perceived health state) to 1.00 (best perceived health state)

  8. Health-related quality of life with the EuroQol-5 dimensions five level index questionnaire (EQ-5D-5L)

    Time frame: 6 months

    The questionnaire covers five dimensions of health: mobility, self-care, usual activities, pain or discomfort, and anxiety or depression. Each dimension has 5 levels: no problems (1), slight problems (2), moderate problems (3), severe problems (4) and extreme problems (5). The patient is asked to indicate his/her health state by ticking the box next to the most appropriate statement in each of the five dimensions. The raw scores are also converted to an EQ-5D index value using a scoring algorithm (British tariff) ranging from -0.594 (worst perceived health state) to 1.00 (best perceived health state)

  9. Scar assessment - using the Patient and Observer Scar Assessment Scale (POSAS)

    Time frame: 1 month

    The POSAS is made up of two scales: the patient scale and the observer scale; each of the six components is scored numerically on a scale of 1 to 10. The component scores are then added together; the worst scar would receive a score of 60, while the best scar would receive a score of 6

  10. Scar assessment - using the Patient and Observer Scar Assessment Scale (POSAS)

    Time frame: 3 months

    The POSAS is made up of two scales: the patient scale and the observer scale; each of the six components is scored numerically on a scale of 1 to 10. The component scores are then added together; the worst scar would receive a score of 60, while the best scar would receive a score of 6

  11. Scar assessment - using the Patient and Observer Scar Assessment Scale (POSAS)

    Time frame: 6 months

    The POSAS is made up of two scales: the patient scale and the observer scale; each of the six components is scored numerically on a scale of 1 to 10. The component scores are then added together; the worst scar would receive a score of 60, while the best scar would receive a score of 6

  12. Health-related out-of- Pocket Costs assessed using the Costs for Patients Questionnaire (CoPaQ)

    Time frame: 1 Month

    The CoPaQ measures patient and caregivers out-of-pocket expenses (direct and indirect) associated with a health condition

  13. Health-related out-of- Pocket Costs assessed using the Costs for Patients Questionnaire (CoPaQ)

    Time frame: 3 Months

    The CoPaQ measures patient and caregivers out-of-pocket expenses (direct and indirect) associated with a health condition

  14. Health-related out-of- Pocket Costs assessed using the Costs for Patients Questionnaire (CoPaQ)

    Time frame: 6 Months

    The CoPaQ measures patient and caregivers out-of-pocket expenses (direct and indirect) associated with a health condition

  15. Health Economics evaluation of resource use and cost effectiveness using Negative Pressure Wound Therapy dressings

    Time frame: 6 Months

    Investigating resource use and cost effectiveness of single-use, prophylactic negative pressure wound therapy versus standard dressings for midline laparotomy wounds based on length of hospital stay and costs of dressings

  16. Visual pain score questionnaire

    Time frame: Day of Surgery

    Measurement of pain intensity

  17. Visual pain score questionnaire

    Time frame: 1 Month

    Measurement of pain intensity

  18. Visual pain score questionnaire

    Time frame: 3 Months

    Measurement of pain intensity

Study contacts

Contact information is provided by the study sponsor or research team.

Eanna Ryan

CONTACT

[email protected]

(01) 261 4037

Sean T Martin

CONTACT

[email protected]

(01) 261 4037

Sponsors and collaborators

Lead sponsor

Royal College of Surgeons, Ireland

Other

Registry information

Official study title

Excision and Negative Pressure Wound Therapy Versus Excision and Leaving Open With Standard Wound Care for Management of Chronic Pilonidal Sinus Disease - A Randomised Controlled Trial

Acronym: ENVELOP

Important dates

Study start
2024
Primary completion
2026
Study completion
2027
First posted
Oct 17, 2024
Registry last updated
Jul 22, 2026

OpenTrials presents study information sourced from ClinicalTrials.gov. The official registry record should be consulted for the latest information.

View the official ClinicalTrials.gov record (opens in a new tab)

This listing is for discovery and informational purposes only. It is not medical advice, does not guarantee that a study is recruiting, and does not determine eligibility. Contact the study team and a qualified healthcare professional when considering participation.

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