Authors' objectives: There is no consensus on optimal management of pilonidal disease. Surgical practice is varied, and existing literature is mainly single-centre cohort studies of varied disease severity, interventions and outcome assessments. A prospective cohort study to determine: disease severity and intervention relationship most valued outcomes and treatment preference by patients recommendations for policy and future research. Pilonidal disease is caused by ingrowing hairs between the buttocks. It can cause pain and infection and may need surgery. We do not know which operation gives the best results, or who operations help. PITSTOP aimed to find out which operation is the best and what is important to patients when deciding on surgery, and to suggest ideas for better treatment and future research. Despite being a common condition, there is no clear consensus as to how pilonidal disease should be managed. Throughout the UK, surgical practice is varied, and existing literature largely consists of single-centre cohort studies using a range of disease classification systems, interventions and outcome assessments. There is a need to improve clinical management of this condition and define future research processes and priorities. PITSTOP aimed to investigate surgical options for the treatment of pilonidal sinus disease (PSD). The objectives were to: Follow patients with symptomatic pilonidal sinus referred to each collaborating site, prospectively recording details of their pit/track anatomy, surgical management, medical events and health-related quality of life (QoL) until 6 months after their operation. Describe the combination of interventions currently in use and quantify clinical and patient-reported outcomes (PROs) associated with each. Identify patient-specific disease features that might predict poor outcome in each treatment group by risk-modelling methods. Derive a case mix-adjusted estimate of the risks associated with common treatment options, using causal inference methods to provisionally rank the optimal management strategies among patients for whom more than one treatment is considered appropriate. Provide an overview of patient views and experiences. Collect the views of patients on which interventions they would rather avoid and which outcomes they most value. Reach a surgeon-based consensus on which subtypes of pilonidal disease may benefit from which treatment options. Reach a surgeon and patient-based consensus on research priorities.

Authors' results and conclusions: Clinician survey: There was significant heterogeneity in surgeon practice preference. Limited training opportunities may impede efforts to improve practice. Cohort study: Over half of patients (60%; N = 667) had a major procedure. For these procedures, pain was greater on day 1 and day 7 (mean difference day 1 pain 1.58 points, 95% confidence interval 1.14 to 2.01 points, n = 536; mean difference day 7 pain 1.53 points, 95% confidence interval 1.12 to 1.95 points, n = 512). There were higher complication rates (adjusted risk difference 17.5%, 95% confidence interval 9.1 to 25.9%, n = 579), lower recurrence (adjusted risk difference −10.1%, 95% confidence interval −18.1 to −2.1%, n = 575), and longer time to healing (>34 days estimated difference) and time to return to normal activities (difference 25.9 days, 95% confidence interval 18.4 to 33.4 days). Mixed-methods analysis: Patient decision-making was influenced by prior experience of disease and anticipated recovery time. The burden involved in wound care and the gap between expected and actual time for recovery were the principal reasons given for decision regret. Discrete choice experiment: The strongest predictors of patient treatment choice were risk of infection/persistence (attribute importance 70%), and shorter recovery time (attribute importance 30%). Patients were willing to trade off these attributes. Those aged over 30 years had a higher risk tolerance (22.35–34.67%) for treatment failure if they could experience rapid recovery. There was no strong evidence that younger patients were willing to accept higher risk of treatment failure in exchange for a faster recovery. Patients were uniform in rejecting excision-and-leave-open because of the protracted nursing care it entailed. Wysocki classification analysis: There was acceptable inter-rater agreement (κ = 0.52, 95% confidence interval 0.42 to 0.61). Consensus exercise: Five research and practice priorities were identified. The top research priority was that a comparative trial should broadly group interventions. The top practice priority was that any interventions should be less disruptive than the disease itself. Results suggest the burden of pilonidal surgery is greater than reported previously. This can be mitigated with better selection of intervention according to disease type and patient desired goals. Results indicate a framework for future higher-quality trials that stratify disease and utilise broad groupings of common interventions with development of a patient-centred core outcome set. Six hundred and sixty-seven patients joined PITSTOP. People who had a major operation had more pain and took longer to return to normal activities. Some were still affected 6 months after surgery. However, disease recurrence was lower than after a minor procedure. Patients based decisions about treatment on the likelihood of success and the time to recover. The study and the surgeons’ survey both showed marked differences in practice. Surgeons tended to offer one or two operations learned during training. A classification tool put cases in similar groups, but this did not influence treatment choices. The consensus exercise identified five research priorities, the top one being to put types of surgery into two groups. Of the five practice priorities, the top one was that surgery should not make the patient worse than the disease. There is variation in the treatment of pilonidal disease. Wound issues and impact on daily living should be avoided. The highlighted research questions should be addressed to improve care. Cohort study Participants Thirty-one UK sites recruited participants over a 46-month period from May 2019 to March 2022. Seven hundred and twenty-nine participants consented to the study; after exclusions due to no procedure (n = 45), incorrect diagnosis (n = 7) and insufficient treatment information (n = 10), there were 667 participants included in the analysis cohort. Six-month follow-up data were available for 71% of participants; recurrence and complication data were available for 94% and 96% of participants, respectively. The burden of surgery for PSD is significantly greater than that reported in the literature. Many surgeons perceive this but continue to practise outdated procedures. While minimally invasive procedures may reduce this burden in many patients, they are not always offered when they could be. This practice may be driven by the desire to achieve cure at the expense of protracted recovery, but this is not always what patients want. Many would trade reduced chance of cure for more rapid recovery. Future practice priorities should follow the ethos of not making the surgery worse than the disease itself and appreciate that patients need to be properly informed about the burden associated with wound care and the likelihood of recurrence associated with different procedures, to minimise DR. Future trials should compare broad groups of interventions (minimally invasive vs. major excisions) stratified by disease severity and utilising a reliable and validated Wysocki classification system. Such trials should incorporate a core set of PROs.

Authors' methods: Observational cohort study with nested mixed-methods case study. Discrete choice experiment. Clinician survey. Three-stage Delphi survey for patients and clinicians. Inter-rater reliability of classification system. Thirty-one National Health Service trusts. Patients aged > 16 years referred for elective surgical treatment of pilonidal disease. Surgery. Pain postoperative days 1 and 7, time to healing and return to normal activities, complications, recurrence. Outcomes compared between major and minor procedures using regression modelling, propensity score-based approaches and augmented inverse probability weighting to account for measured potential confounding features. Incomplete recruitment and follow-up data were an issue, particularly given the multiple interventions. Assumptions were made regarding risk adjustment. We looked at what operations were done and their outcomes. We interviewed patients about their experiences. Some completed a survey to help us understand what operations they might prefer based on risks and outcomes. Surgeons completed a survey about their experiences, and we explored whether a new tool could help us tell the difference between ‘mild’ and ‘bad’ disease. We used findings from these studies to help patients and surgeons give priorities for future practice and research. PITSTOP was an observational cohort with nested mixed-methods and qualitative design which took place across 33 NHS Trust sites in the UK. The study had an additional clinician survey component and validation of a classification system and culminated in a three-stage Delphi exercise to identify research and practice priorities. Eligible patients undergoing surgical management for PSD and interested in participating were consented to the study. Participants referred to a collaborating centre for definitive elective surgical treatment of PSD were required to meet the following criteria: Consenting patients over 16 years of age with PSD. Participants were ineligible if any of the following conditions were met: Asymptomatic Pregnant Unable to give consent Acute abscess Hypersensitivity to the sealants. As PITSTOP is a cohort study examining current practice, there are no primary outcome measures. The following data were collected: pain (numeric rating scale) on day 1 and day 7 postoperatively and at each follow-up EuroQol five dimensions five levels questionnaire (EQ-5D-5L) QoL at each follow-up interactions with primary and secondary care length of time to healing return to normal activities complications recurrence infection. Thirty-one UK sites recruited participants over a 46-month period from May 2019 to March 2022. Seven hundred and twenty-nine participants consented to the study; after exclusions due to no procedure (n = 45), incorrect diagnosis (n = 7) and insufficient treatment information (n = 10), there were 667 participants included in the analysis cohort. Six-month follow-up data were available for 71% of participants; recurrence and complication data were available for 94% and 96% of participants, respectively.

Project Status: Completed

URL for project: https://www.journalslibrary.nihr.ac.uk/programmes/hta/17/17/02

Year Published: 2024

URL for published report: https://www.journalslibrary.nihr.ac.uk/hta/KFDQ2017

URL for additional information: English

English language abstract: An English language summary is available

Publication Type: Full HTA

Country: England, United Kingdom

DOI: 10.3310/KFDQ2017

Organisation Name: NIHR Health Technology Assessment programme

Contact Address: NIHR Journals Library, National Institute for Health and Care Research, Evaluation, Trials and Studies Coordinating Centre, Alpha House, University of Southampton Science Park, Southampton SO16 7NS, UK

Contact Name: journals.library@nihr.ac.uk

Contact Email: journals.library@nihr.ac.uk