Chronic rhinosinusitis (CRS) is a common inflammatory condition that significantly impairs quality of life and is often insufficiently managed with standard medical therapy alone. Emerging evidence suggests that manual therapy approaches, including osteopathic manipulative treatment, may provide additional clinical benefits by improving lymphatic drainage, modulating autonomic function, and enhancing mucociliary clearance.

This randomized controlled trial aims to investigate the effectiveness of craniosacral osteopathic manipulative treatment (OM-KST) as an adjunct to standard medical therapy in individuals with chronic rhinosinusitis. Participants diagnosed with CRS will be randomly allocated into two groups: a control group receiving standard medical treatment and an intervention group receiving OM-KST in addition to medical treatment.

The intervention will consist of an 8-session craniosacral osteopathic protocol applied over 4 weeks. Outcomes will be assessed at baseline, post-intervention, and follow-up periods using validated clinical and patient-reported measures. Primary and secondary outcomes will include symptom severity, nasal obstruction, pain threshold, endoscopic findings, and quality of life (e.g., SNOT-22, NOSE, EuroQol-5D).

This study is designed to provide high-level evidence on the clinical effectiveness of a multidisciplinary and integrative treatment approach for CRS, addressing both subjective symptoms and objective clinical findings.

Chronic rhinosinusitis (CRS) is a persistent inflammatory condition of the sinonasal mucosa lasting longer than 12 weeks and affecting approximately 10% of the global population. It is characterized by symptoms such as nasal obstruction, mucopurulent discharge, facial pain/pressure, and olfactory dysfunction, all of which significantly impair quality of life. Despite standard medical management-including intranasal corticosteroids, saline irrigation, antihistamines, and antibiotics when indicated-a substantial proportion of patients experience persistent or recurrent symptoms, highlighting the need for complementary and integrative therapeutic approaches.

Osteopathic manipulative treatment (OMT), particularly craniosacral techniques, has been proposed as a therapeutic approach that may influence physiological processes relevant to CRS. These mechanisms include modulation of the autonomic nervous system, enhancement of lymphatic and venous drainage, and improvement of cranial rhythmic impulse and tissue mobility. Through these mechanisms, OMT may facilitate mucociliary clearance and contribute to the reduction of inflammation and symptom burden.

Although preliminary studies have reported beneficial effects of osteopathic and manual therapy interventions in CRS, existing evidence is limited by small sample sizes, lack of adequate control groups, and reliance predominantly on subjective outcome measures. Furthermore, objective assessments such as endoscopic findings and imaging-based evaluations have been insufficiently integrated into prior research.

The present study is designed as a prospective, two-arm, randomized controlled trial to evaluate the effectiveness of craniosacral osteopathic manipulative treatment (OM-KST) as an adjunct to standard medical therapy in individuals with CRS. Eligible participants aged 18-65 years diagnosed with CRS by an otorhinolaryngologist will be randomly assigned to either a control group receiving standard medical treatment or an intervention group receiving OM-KST in addition to medical treatment.

The intervention protocol will consist of eight sessions over a 4-week period (two sessions per week), with each session lasting approximately 45 minutes. The OM-KST protocol will include a structured sequence of techniques focusing on vagal stimulation, lymphatic drainage, and craniosacral regulation.

Outcome measures will be assessed at baseline (T0), immediately after the intervention (T1), and at follow-up. Both subjective and objective measures will be employed, including validated questionnaires such as the Sinonasal Outcome Test (SNOT-22), Nasal Obstruction Symptom Evaluation (NOSE), and EuroQol-5D, as well as pressure pain threshold assessment using algometry and sinonasal endoscopic evaluation. Where appropriate, imaging-based assessments may be incorporated to evaluate structural and inflammatory changes.

Statistical analyses will be conducted using appropriate parametric or non-parametric tests depending on data distribution, with a significance level set at p < 0.05. Effect sizes and clinically meaningful changes will also be considered to enhance the interpretation of clinical relevance.

This study aims to provide high-quality evidence regarding the clinical effectiveness of a multimodal and integrative treatment strategy for CRS by combining standardized medical therapy with osteopathic craniosacral interventions. The findings are expected to contribute to the development of evidence-based, patient-centered management approaches and to address existing gaps in the literature by integrating both objective and patient-reported outcomes.

Inclusion Criteria:

• Adults aged 18-65 years
• Diagnosis of chronic rhinosinusitis (CRS) confirmed by an otorhinolaryngologist
• Presence of at least two of the following symptoms for ≥12 weeks:
• Nasal obstruction
• Mucopurulent nasal discharge
• Facial pain/pressure
• Reduced or loss of smell
• Ability to provide informed consent

Exclusion Criteria:

• Acute rhinosinusitis or acute exacerbation of CRS
• History of cranial, facial, or cervical surgery within the past year
• Neurological or structural conditions contraindicating craniosacral therapy (e.g., intracranial hemorrhage, aneurysm, Chiari malformation)
• Cerebrospinal fluid (CSF) leak
• Recent manual therapy intervention (within the last 2 months)
• Use of additional therapeutic interventions during the study period
• Severe cognitive impairment limiting participation or informed consent
• Pregnancy (high-risk pregnancy)

Individual participant data (IPD) will not be shared due to ethical and legal restrictions related to the protection of personal data. The study involves sensitive health information, and sharing de-identified data may still pose a risk of re-identification. All data will be securely stored and used only for the purposes of this study in accordance with institutional and national data protection regulations.

This study is designed as an open-label randomized controlled trial. Due to the nature of the intervention, participant blinding is not feasible, as individuals receiving craniosacral osteopathic manipulative treatment (OM-KST) can clearly distinguish the manual therapy intervention from standard medical treatment. No sham or placebo intervention is applied. Outcome assessments are conducted using standardized and validated measurement tools to minimize potential assessment bias.