Swedish National Parotidectomy Study (SNaPs): Drainless Versus Standard Surgery (SNaPs)

A Prospective, Randomized, Multicenter Non-Inferiority Trial Evaluating the Safety of Parotidectomy Without Active Surgical Drainage (Svenska Nationella Parotisstudien)

The purpose of this study The purpose of this study is to find out if it is safe to perform surgery on the parotid gland (the large salivary gland in front of the ear) without using a wound drain. A wound drain is a small plastic tube used to remove excess fluid from the surgical site after the operation. Currently, using a drain is the standard practice in Sweden, which often means patients must stay in hospital overnight. Researchers want to see if skipping the drain is just as safe and if it could allow more patients to return home on the same day as their surgery.

What happens during the study

Participants in this study will be randomly assigned to one of two groups during their surgery:

Group 1: Will receive the standard treatment with a wound drain.

Group 2: Will have the surgery performed without a wound drain.

Apart from the use of a drain, all participants will receive the same surgical care. After the operation, researchers will monitor the healing process. Participants will be asked to fill out questionnaires about their health and any symptoms at one week and six months after their surgery.

The goal of the study The main goal is to compare the safety of the two methods. Researchers will look at whether there is any difference in the number of complications, such as fluid build-up (seroma), bleeding, or infections, between those who had a drain and those who did not. The study also aims to evaluate if avoiding a drain improves the patient's quality of life and if it is a more cost-effective approach for the healthcare system.

Study Overview

• Status: Recruiting
• Conditions: Parotid Neoplasms; Post-operative Complications; Seroma as Procedural Complication
• Intervention / Treatment: Procedure: Omission of active wound drain; Procedure: Active wound drainage (Standard of Care)

• Study Type: Interventional
• Enrollment (Estimated): 600
• Phase: Not Applicable

Contacts and Locations

• Study Contact: Name: Karl Sandström, MD, PhD; Phone Number: +46 76 113 29 52; Email: karl.sandstrom@akademiska.se

Study Locations

• Sweden
  • Stockholm, Sweden
    • Recruiting
    • Karolinska University Hospital
  • Trollhättan, Sweden
    • Recruiting
    • NÄL
  • Uppsala, Sweden
    • Recruiting
    • Uppsala University Hospital, Department of Otorhinolaryngology
    • Contact: Karl Sandström, MD, PhD; Phone Number: +46 76 113 29 52; Email: karl.sandstrom@akademiska.se

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Adult; Older Adult
• Accepts Healthy Volunteers: No

Description

Inclusion Criteria:

• Patients scheduled to undergo partial or superficial parotidectomy without concurrent soft tissue surgery, in cases where a wound drain is traditionally used (extirpation of single adjacent lymph nodes is acceptable).
• ASA physical status class 1-3.
• Aged 18 years or older.
• The patient understands the participant information and is able to make an informed choice.

Exclusion Criteria:

• Previous parotid surgery on the same side
• Tumour with parapharyngeal extension.
• Ongoing or planned perioperative treatment with tranexamic acid.
• Ongoing treatment with dual antiplatelet therapy (single agent therapy, such as Aspirin or Clopidogrel, is not an exclusion criterion).
• Ongoing treatment with anticoagulants (NOAC, Warfarin) at the time of surgery. NOAC must be discontinued at least 24 hours before surgery.
• Ongoing treatment with low molecular weight heparin in doses higher than: Fragmin 5000 IU/day, Clexane 40 mg/day, or Innohep 4500 IU/day.Ongoing treatment for malignancy.Known coagulation disorder.
• Platelet count <150 x 10⁹
• PK-INR >1.2.
• Hb <120 g/L.
• APTT >42s.
• Preoperative impaired facial nerve function on the affected side (Sunnybrook Facial Grading System score <90).
• Supplementary postoperative treatment such as radiotherapy or extended surgery.

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Health Services Research
• Allocation: Randomized
• Interventional Model: Parallel Assignment
• Masking: None (Open Label)

Number of Arms

2

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Experimental: Drainless Group (Intervention); Participants in this group will undergo partial or superficial parotidectomy without the placement of a postoperative active wound drain. The surgical site is closed according to the standard technique, but the suction drain is omitted.	Procedure: Omission of active wound drain; The surgical procedure is performed without the insertion of an active suction drain. All other aspects of the surgical care and postoperative monitoring follow standard protocols.
Active Comparator: Standard Drain Group (Control); Participants in this group will undergo partial or superficial parotidectomy with the placement of a postoperative active wound drain, according to current standard clinical routine in Sweden.	Procedure: Active wound drainage (Standard of Care); An active suction drain is placed in the surgical bed before wound closure, which is the current established clinical practice for parotidectomy in Sweden.

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Cumulative incidence of early postoperative complications requiring intervention	The primary outcome is the number of participants experiencing at least one early complication, defined as a salivary fistula, haematoma, seroma/sialocele, or surgical site infection that requires invasive or medical treatment (e.g., aspiration, re-operation, or antibiotics).	From the day of surgery up to 7 weeks postoperatively.

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Requirement for inpatient hospital care after the day of surgery.	Evaluation of the number of participants requiring unplanned hospital admission or prolonged stay related to the surgical procedure.	From the first postoperative day up to 6 months
Postoperative facial nerve function.	Assessment of facial nerve function using the Sunnybrook Facial Grading System (SFGS). The SFGS is a clinical evaluation scale that ranges from 0 to 100. A score of 0 indicates complete facial paralysis, while a score of 100 represents normal facial function. Higher scores indicate a better outcome (better facial nerve function).	Baseline (preoperative), at discharge, at 7 weeks, and at 6 months
Incidence of Frey's syndrome	Subjective and objective assessment of gustatory sweating (Frey's syndrome).	6 months postoperatively.
Health-related quality of life (EQ-5D-5L)	Evaluated using the EQ-5D-5L descriptive system, which comprises 5 dimensions (mobility, self-care, usual activities, pain/discomfort, anxiety/depression). Each dimension is scored from 1 (no problems) to 5 (extreme problems). The digits are combined into a 5-digit health state profile, which is then converted into a single index value. Index values range from less than 0 (where 0 is a state equivalent to death and negative values are states worse than death) to 1.0 (perfect health). Higher scores indicate a better quality of life outcome.	7 weeks, and 6 months postoperatively
Postoperative length of stay	Total number of days spent in hospital following the surgical procedure.	Through initial hospital discharge, an average of 1.5 days, assessed up to 7 weeks.
Symptom-specific outcomes (SwPOI-8)	Measured using the Swedish Parotidectomy Outcome Inventory 8 (SwPOI-8), a disease-specific instrument assessing subjective symptoms after parotid surgery (e.g., pain, sensory disturbances, scarring, facial palsy, sweating, dry mouth). Each of the 8 items is scored on a Likert scale from 0 to 3, with a total score ranging from 0 to 24. Higher scores indicate a greater symptom burden and a worse outcome.	7 weeks and 6 months postoperatively

Collaborators and Investigators

• Sponsor: Uppsala University Hospital
• Collaborators: Uppsala University; Göteborg University; Västra Götalandsregionen

Study record dates

Study Major Dates

• Study Start (Actual): May 6, 2026
• Primary Completion (Estimated): December 1, 2030
• Study Completion (Estimated): December 1, 2032

Study Registration Dates

• First Submitted: May 19, 2026
• First Submitted That Met QC Criteria: May 26, 2026
• First Posted (Actual): June 2, 2026

Study Record Updates

• Last Update Posted (Actual): June 2, 2026
• Last Update Submitted That Met QC Criteria: May 26, 2026
• Last Verified: May 1, 2026

More Information

Terms related to this study

• Keywords: Quality of life; Postoperative complications; Randomised controlled trial; Seroma; Non-inferiority; Parotidectomy; Hematoma; Surgical drainage; Wound drains; Salivary gland surgery
• Additional Relevant MeSH Terms: Mouth Diseases; Stomatognathic Diseases; Pathologic Processes; Neoplasms by Site; Neoplasms; Hemorrhage; Inflammation; Head and Neck Neoplasms; Salivary Gland Diseases; Mouth Neoplasms; Parotid Diseases; Salivary Gland Neoplasms; Pathological Conditions, Signs and Symptoms; Hematoma; Postoperative Complications; Parotid Neoplasms; Seroma; Health Services Administration; Health Care Quality, Access, and Evaluation; Quality of Health Care; Quality Indicators, Health Care; Standard of Care
• Other Study ID Numbers: 2025-07555-01

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: NO
• IPD Plan Description: Individual participant data will not be shared publicly due to current Swedish legislation and the European General Data Protection Regulation (GDPR), which protect the privacy of study participants. Sharing of pseudonymised individual-level data would require specific legal review and institutional agreements to ensure continued data protection

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No