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Trial registered on ANZCTR

Registration number
Ethics application status
Date submitted
Date registered
Date last updated
Type of registration
Prospectively registered

Titles & IDs
Public title
The effect of isotretinoin on mucosal wound healing in patients with chronic sinusitis: a pilot study.
Scientific title
The effect of isotretinoin on mucosal wound healing in patients with chronic sinusitis, a pilot study by the Department of Surgery, University of Auckland.
Secondary ID [1] 287482 0
Universal Trial Number (UTN)
Trial acronym
Linked study record

Health condition
Health condition(s) or problem(s) studied:
Chronic sinusitis 296222 0
Condition category
Condition code
Inflammatory and Immune System 296495 296495 0 0
Other inflammatory or immune system disorders
Respiratory 296562 296562 0 0
Other respiratory disorders / diseases

Study type
Description of intervention(s) / exposure
Pilot RCT. 32 newly diagnosed patients with chronic sinusitis (CRS) will be recruited over 18 months. These patients will be on the waiting list for endoscopic sinus surgery, but have not yet undergone surgery.

Following informed consent to participate in the study, 2 weeks prior to surgery, a patient questionnaire to obtain subjective patient symptom scores (SNOT-22) will be performed. Swabs will be taken from the middle meatus to provide baseline data. This is a non-invasive procedure performed under endoscopic guidance, which is routinely undertaken in ORL clinics to guide appropriate antibiotic therapy for patients with sinusitis. Patients will then have topical anesthesia applied to the nasal cavity (co-phenylcaine or equivalent). A small, 3-5mm region of the antero-inferior aspect of the middle turbinate will be biopsied to create a wound.

Patients will then be allocated numbered but unmarked drug packs (double blinded) in a computer generated random sequence, to receive 2 weeks of either:

1) isotretinoin capsule 10mg once daily
2) a placebo capsule

Monitoring of medication adherence will be assessed by drug packet return.

Two weeks later, at the time of surgery, the SNOT-22 will be again performed by the patient as well as an intraoperative endoscopic healing score (Lund-Kennedy) by the surgeon. Swabs will again be taken from the middle meatus. The inferior aspect of the middle turbinate, which is often resected routinely, will be biopsied to remove both the lesion made in clinic and a small amount of the surrounding, uninjured mucosa.

Following surgery, patients will be continued on study medications (including placebo) at the same dose and frequency as the previously two weeks plus, for another two weeks. Patients will also be given any additional routine medications (usually antibiotics and steroids) as per clinical needs. Patients will be seen again at 2 weeks following surgery, at which point swabs will again be taken, along with the SNOT-5 and Lund-Kennedy scores. After this, patients will be discharged from the study and study medications (isotretinoin or placebo) stopped.
Intervention code [1] 292863 0
Treatment: Drugs
Comparator / control treatment
Data from patients receiving isotretinoin and the placebo tablet will be compared.

Placebo tablets contain microcellulose.
Control group

Primary outcome [1] 296124 0
Composite outcomes - Analysis will be done for cilial recovery, collagen content, goblet cell recovery, epithelial thickness, mucosal thickness, immune cells and bacterial cells. Comparisons will be made between injured and uninjured tissue.
Timepoint [1] 296124 0
performed on sample collected at the time of surgery (2 weeks after starting study medication or placebo)
Primary outcome [2] 296177 0
The swabs taken before and after medical therapy will be compared. Alongside conventional culture methods, samples will also be subjected to PCR amplification of the bacterial 16S ribosomal RNA (16S rRNA) genes.
Timepoint [2] 296177 0
At times 0, 2 weeks (surgery) and 4 weeks (post op).
Primary outcome [3] 296178 0
Levels of important inflammatory cytokines will be measured in the mucus of the patients using a cytokine ELISA.
Timepoint [3] 296178 0
At times 0, 2 weeks (surgery) and 4 weeks (post op).
Secondary outcome [1] 317556 0
Patient reported symptom scores (Sinonasal Outcome Test –22)
Timepoint [1] 317556 0
At times 0, 2 weeks (surgery) and 4 weeks (post op).
Secondary outcome [2] 317721 0
Endoscopic scoring (Lund-Kennedy Endoscopic Score).
Timepoint [2] 317721 0
At times 0, 2 weeks (surgery) and 4 weeks (post op).
Secondary outcome [3] 318089 0
pH of mucus will be measured using a pH indicator
Timepoint [3] 318089 0
At times 0, 2 weeks (surgery) and 4 weeks (post op).

Key inclusion criteria
Patients newly diagnosed with CRS, are eligible for sinus surgery and on the waiting list for endoscopic sinus surgery, but not yet undergone surgery.

Patients providing fully informed consent to participate in this study.
Minimum age
16 Years
Maximum age
No limit
Both males and females
Can healthy volunteers participate?
Key exclusion criteria
Patients who are acutely unwell.
Patients with cystic fibrosis.
Patients with a history of previous nasal surgery.
Male patients less than 16 years of age
Female patients less than 45 years of age (owing to isotretinoin teratogenicity risk)
Immunodeficiency (congenital or acquired)
Congenital mucociliary problems (e.g. primary ciliary dyskinesia)
Non-invasive and invasive fungal sinus disease
Systemic vasculitis and granulomatous diseases
History of cocaine abuse;
Patients requiring sinus surgery for neoplasia
Patients unable to consent (e.g. lack of mental capacity)

Study design
Purpose of the study
Allocation to intervention
Randomised controlled trial
Procedure for enrolling a subject and allocating the treatment (allocation concealment procedures)
Central randomisation by computer database
Methods used to generate the sequence in which subjects will be randomised (sequence generation)
Central randomisation by computer database
Masking / blinding
Blinded (masking used)
Who is / are masked / blinded?
The people receiving the treatment/s
The people administering the treatment/s
The people assessing the outcomes
The people analysing the results/data
Intervention assignment
Other design features
Phase 1
Type of endpoint(s)
Statistical methods / analysis
As the effect size for this intervention is not known, this study serves as a pilot RCT.

Analysis of variance for changes following treatment and differences of means within groups will be assessed. Alpha and beta diversity of microbial communities will be analysed. Statistical significance will be accepted at the 0.05 level.

Recruitment status
Date of first participant enrolment
Date of last participant enrolment
Date of last data collection
Sample size
Accrual to date
Recruitment outside Australia
Country [1] 7170 0
New Zealand
State/province [1] 7170 0
Country [2] 7171 0
United States of America
State/province [2] 7171 0

Funding & Sponsors
Funding source category [1] 292058 0
Self funded/Unfunded
Name [1] 292058 0
Address [1] 292058 0
Country [1] 292058 0
Primary sponsor type
Associate Professor Richard Douglas
Department of Surgery
The University of Auckland
Level 12, Room 12-087, ACH Support Building, Park Road, Grafton. 1142.
New Zealand
Secondary sponsor category [1] 290729 0
Name [1] 290729 0
Dr Ravi Jain
Address [1] 290729 0
Department of Surgery
The University of Auckland
Level 12, Room 12-087, ACH Support Building, Park Road, Grafton. 1142.
Country [1] 290729 0
New Zealand
Other collaborator category [1] 278630 0
Name [1] 278630 0
Professor Peter Hwang
Address [1] 278630 0
Stanford ENT
801 Welch Rd
MC 5739
Stanford, CA94305
Country [1] 278630 0
United States of America

Ethics approval
Ethics application status
Ethics committee name [1] 293541 0
New Zealand Northern A Health and Disability Ethics Committee
Ethics committee address [1] 293541 0
Ministry of Health
C/- MEDSAFE, Level 6, Deloitte House
10 Brandon Street
PO Box 5013 Wellington. 6011
Ethics committee country [1] 293541 0
New Zealand
Date submitted for ethics approval [1] 293541 0
Approval date [1] 293541 0
Ethics approval number [1] 293541 0

Brief summary
Chronic rhinosinusitis (CRS) is an inflammatory disease affecting around 5% of people in Western populations and is associated with significant morbidity. The aetiology of CRS remains unclear, although it is believed to involve a complex interaction between host immunity and a shift in the intranasal microbial community. Mucosal wound healing within this context is a complex and highly coordinated process, which is influenced by a number of host and environmental factors. A number of topical drugs and dressings have been investigated for their ability to enhance wound healing after sinus surgery, but so far none have been shown to be consistently better than no treatment at all.

Retinoic acid is an active metabolite of vitamin A that has been widely used in dermatology for 50 years. Recently, several animal studies have suggested significant improvements in post surgical healing following treatment with a topical retinoid gel.

This pilot study aims to observe the effect of isotretinoin to:
1) understand the potential for use in mucosal wound healing in the context of chronic sinusitis,
2) Improve outcomes following surgery,
3) Assist development of targeted approaches to improving perioperative care

Study endpoints will be clinical scores combined with laboratory measurements of healing (histology), and microbiology.
Trial website
Trial related presentations / publications
Public notes

Principal investigator
Name 60378 0
A/Prof Richard Douglas
Address 60378 0
Department of Surgery University of Auckland Private Bag 92019 Auckland Mail Centre 1142
Country 60378 0
New Zealand
Phone 60378 0
+64 27 2186083
Fax 60378 0
Email 60378 0
Contact person for public queries
Name 60379 0
A/Prof Richard Douglas
Address 60379 0
Department of Surgery University of Auckland Private Bag 92019 Auckland Mail Centre 1142
Country 60379 0
New Zealand
Phone 60379 0
+64 27 2186083
Fax 60379 0
Email 60379 0
Contact person for scientific queries
Name 60380 0
A/Prof Richard Douglas
Address 60380 0
Department of Surgery University of Auckland Private Bag 92019 Auckland Mail Centre 1142
Country 60380 0
New Zealand
Phone 60380 0
+64 27 2186083
Fax 60380 0
Email 60380 0

No information has been provided regarding IPD availability
Summary results
No Results