Position-Guided Nasopharyngeal Irrigation for Post-Radiotherapy Ulcer Care in Nasopharyngeal Carcinoma

Summary

This protocol describes how to perform position-guided nasopharyngeal irrigation for post-radiotherapy ulcer care in nasopharyngeal carcinoma. It details device setup, catheter positioning, low-pressure saline delivery, drainage, and aseptic handling to enable standardized and reproducible irrigation in clinical and home settings.

Abstract

To describe and standardize a position-guided nasopharyngeal irrigation protocol for post-radiotherapy nasopharyngeal ulceration (RINU) in patients with nasopharyngeal carcinoma (NPC), a prospective comparative clinical setting was used among 184 patients diagnosed with RINU between January and March 2025. Participants were randomly assigned to receive either routine manual irrigation (n = 92) or irrigation using an improved position-guided device (n = 92). The protocol incorporates an anatomically guided, double-lumen catheter with a direction-controlled tip, an adjustable outer sheath, and a low-pressure manual pump system operating at 50-100 mmHg, enabling controlled saline delivery with simultaneous drainage. Core procedural elements include catheter positioning relative to the nasopharyngeal vault, regulation of irrigation pressure and flow, sequencing of irrigation cycles, and management of continuous outflow to minimize fluid retention. The protocol was applied in a clinical setting with evaluations performed at baseline, 1 month, and 2 month using standardized endoscopic grading of mucosal injury, assessment of secretion viscosity, bacterial culture testing, pain measured by the visual analog scale (VAS), and comfort assessed by the General Comfort Questionnaire (GCQ). Baseline demographic and clinical characteristics were comparable between groups. During follow-up, differences were observed between groups in mucosal healing status, secretion characteristics, microbiological findings, and patient-reported symptom measures, with statistically significant between-group differences across endpoints (all p < 0.05). Endoscopic examinations documented granulation and epithelialization patterns over time, and no severe adverse events were observed during protocol application. This protocol describes a reproducible, standardized framework for position-guided nasopharyngeal irrigation in the post-radiotherapy management of RINU.

Introduction

Nasopharyngeal carcinoma (NPC) is a unique malignancy arising from the epithelial lining of the nasopharynx, with a remarkably unbalanced geographic distribution. It is highly prevalent in southern China and Southeast Asia, where Epstein-Barr virus (EBV) infection, genetic susceptibility, and environmental co-factors contribute to its pathogenesis¹. Owing to its deep anatomic location and radiosensitive histology, radiotherapy, particularly intensity-modulated radiotherapy (IMRT), remains the mainstay of curative treatment for non-metastatic NPC². With the advent of IMRT and concurrent chemoradiotherapy, locoregional control and overall survival have substantially improved, achieving 5-year survival rates exceeding 80%. However, these therapeutic advances have been accompanied by a rise in radiation-related complications that increasingly shape the quality of survivorship. Among them, post-radiotherapy nasopharyngeal ulceration (RINU) represents one of the most troublesome late adverse effects, characterized by mucosal breakdown, secondary infection, persistent pain, and, in severe cases, skull-base necrosis or catastrophic hemorrhage^3,4. The reported incidence of nasopharyngeal ulceration after IMRT ranges from 2% to 8%, but may be as high as 15% in re-irradiated or locally recurrent cases⁵. Although the pathogenesis is multifactorial, it involves mucosal ischemia, chronic hypoxia, radiation-induced endarteritis, bacterial colonization, and impaired tissue regeneration^6,7. The combination of high radiation dose, limited vascular supply, and delayed mucosal healing leads to chronic non-healing ulcers that can erode deeply into the skull base or carotid canal, posing an imminent risk of fatal bleeding⁸.

In recent years, several dose-volume predictors have been identified for RINU. A large-scale study involving more than 6,000 NPC patients reported that the minimum dose delivered to the most irradiated 3 cm³ of the nasopharyngeal mucosa (D3cc) was independently associated with ulcer formation, with a threshold of approximately 73.7 Gy⁹. Similarly, a multi-institutional re-irradiation cohort demonstrated that the cumulative equivalent dose in 2-Gy fractions (EQD₂) delivered to 80% of the nasopharyngeal volume (D80) was approximately 137 Gy and predicted ulcer development with high specificity¹⁰. While such evidence informs radiation planning, the management of established nasopharyngeal ulceration remains largely empirical. Conventional approaches, including isotonic saline irrigation, topical antibiotics, corticosteroids, and endoscopic debridement, have limited efficacy and are associated with high recurrence rates¹¹. Conservative irrigation is the most commonly prescribed first-line therapy, yet it is typically performed with simple syringes or squeeze bottles, lacking control of direction, flow, or pressure. Unlike commonly used sinonasal irrigation approaches (e.g., syringes, squeeze bottles, gravity-based systems), our device is specifically engineered for the post-radiotherapy nasopharynx, enabling reproducible catheter positioning and direction-controlled delivery to the nasopharyngeal vault with simultaneous drainage. This targeted, position-guided design is intended to overcome the key limitation of conventional methods, namely, non-reproducible coverage of the ulcer bed in distorted post-irradiation anatomy. Local irrigation is commonly used as a supportive measure to manage post-radiotherapy upper aerodigestive tract complications, including nasopharyngeal ulceration, with the goal of removing necrotic debris, diluting inflammatory secretions, and reducing bacterial burden¹². In clinical practice, such irrigation is most often performed using manual techniques adapted from sinonasal lavage, including low-volume sprays and high-volume devices such as squeeze bottles or gravity-based systems¹². High-volume, low-pressure irrigation has been shown to improve mucosal coverage and secretion clearance within the nasal cavity and paranasal sinuses and has been applied in patients with nasopharyngeal carcinoma to alleviate post-irradiation rhinosinusitis¹³. However, these approaches are primarily designed to bathe the nasal cavity rather than to reproducibly target the nasopharyngeal vault. In the post-radiotherapy nasopharynx, fibrosis, anatomical distortion, and deep recesses can limit access to the ulcer bed, while the proximity of the Eustachian tube orifice and skull-base vascular structures increases the risk of unintended irrigant flow. As a result, conventional manual irrigation methods may provide incomplete and non-reproducible delivery of irrigant to the ulcer surface in this altered anatomy. Consequently, secretion retention and suspected bacterial biofilm formation may contribute to persistent local inflammation and necrosis, which are clinically associated with delayed re-epithelialization and increased infection risk^12,13. In clinical practice, this protocol is intended for patients with mild to moderate post-radiotherapy nasopharyngeal ulceration in whom the ulcer surface can be accessed endoscopically and who do not show signs of active hemorrhage or exposed major vessels. Irrigation should be avoided or performed exclusively under clinician supervision in cases of deep necrosis, suspected carotid involvement, uncontrolled bleeding, or severe anatomic instability. Clinically, controlled pressure and flow refer to low-pressure, steady irrigation sufficient to mobilize secretions and debris while avoiding excessive shear stress on irradiated mucosa.

A retrospective study of 53 patients with ulcers of post-radiation nasopharyngeal necrosis highlighted that those receiving only empirical irrigation and anti-inflammatory therapy achieved limited healing, whereas severe ulcers required multiple endoscopic debridements and were associated with a 15% risk of massive hemorrhage¹⁴. Moreover, high T stage, poor anemia correction during radiotherapy, and suboptimal chemotherapy response were predictors of poor outcome. Such findings underscore a crucial clinical gap: while prevention of RINU relies on optimized dosimetry, effective local therapy for established ulcers remains unavailable. At present, there appears to be no widely adopted, anatomically guided irrigation device specifically designed for post-radiotherapy nasopharyngeal ulceration in NPC patients. The nasopharyngeal cavity's depth, curvature, and proximity to critical structures such as the Eustachian orifice and internal carotid artery make blind irrigation both inefficient and potentially unsafe¹⁵. Hence, there is a compelling need for a device that can accurately guide irrigation to the ulcer bed, deliver controlled flow, minimize mucosal trauma, and facilitate wound healing under visualized or positional feedback.

To address this unmet need, we designed and developed an improved position-guided nasopharyngeal irrigation device that integrates engineering precision with clinical usability. The system comprises a flexible double-lumen catheter with a pre-curved directional tip conforming to post-irradiation anatomical geometry, a flow-controlled irrigation chamber, and an optional negative-pressure drainage channel to remove effluent and necrotic debris. An external positioning guide allows alignment according to individualized nasopharyngeal depth and curvature, ensuring targeted delivery of the irrigation solution to the ulcer bed. The device can be operated under physician guidance or by trained patients at home, using isotonic saline or diluted antiseptic solution. Its novelty lies in three dimensions: anatomical precision, whereby the pre-shaped catheter enables reproducible navigation into the nasopharyngeal vault without injuring surrounding mucosa; controlled irrigation parameters, with adjustable flow and pressure to ensure effective cleansing while avoiding mechanical disruption of fragile tissues; and integrated drainage and positional feedback, in which continuous outflow prevents fluid retention and contamination, and reference markings facilitate standardized positioning across sessions. This engineering-clinical synergy transforms a traditionally manual, inconsistent procedure into a quantitatively controllable and anatomically guided intervention.

We hypothesized that the use of this device may influence ulcer healing, bacterial colonization, and patient-reported symptoms compared with conventional irrigation. The rationale is mechanistically sound: enhanced mechanical clearance of necrotic tissue and exudate facilitates granulation, continuous moisture maintains a favorable microenvironment, and elimination of local infection reduces inflammatory cytokine load that otherwise impairs epithelial regeneration¹⁶. Furthermore, directional flow avoids excessive shear stress on intact mucosa, reducing secondary trauma. From a translational perspective, such a device could standardize local care for RINU, allowing reproducible outcomes across institutions and enabling future integration with image-guided or robotic endoscopic systems.

The present study, therefore, represents the first controlled clinical evaluation of a position-guided irrigation device specifically designed for RINU. We conducted a prospective comparative study to assess its effectiveness in promoting ulcer healing, reducing clinical symptoms, and improving patient quality of life relative to conventional manual irrigation. Endoscopic evaluation, symptom scoring, and bacterial culture were systematically performed at predefined intervals to quantify outcomes. Beyond clinical efficacy, this study also provides a proof-of-concept that engineering-driven medical device innovation can meaningfully improve supportive care for radiation-induced complications in head-and-neck oncology. We believe that the findings will provide a foundation for larger multicenter trials and pave the way for standardized post-radiotherapy nasopharyngeal rehabilitation protocols. Ultimately, this work addresses a critical gap between technological capability and clinical need, offering a safe, reproducible, and effective solution for one of the most intractable complications in NPC survivorship care.

Protocol

This study was conducted in accordance with the ethical principles of the Declaration of Helsinki and the institutional regulations governing human research. The research protocol was reviewed and approved by the Institutional Review Board of The First Affiliated Hospital of Hainan Medical University (Approval ID: 2025-KYL-158). Written informed consent was obtained from all participants prior to enrollment. The study was prospectively registered and implemented under continuous ethical supervision. All participants received psychological counseling and pain management education prior to enrollment to reduce anxiety and discomfort related to repeated irrigation. No participant withdrew due to intolerable pain or distress during the study.

Study design and participants
This prospective study was conducted at The First Affiliated Hospital of Hainan Medical University between January and March 2025. A total of 184 patients with NPC who developed RINU were enrolled according to predefined eligibility criteria. All patients had completed full-dose intensity-modulated radiotherapy and had ulcerative lesions confirmed by nasal endoscopic examination.

Eligible participants were randomly assigned in a 1:1 ratio to either the control group (n = 92), which received routine nasopharyngeal irrigation, or the intervention group (n = 92), which received irrigation using an improved position-guided nasopharyngeal irrigation device. Inclusion criteria were: age 18-85 years; histopathological diagnosis of NPC with completed radiotherapy; presence of nasopharyngeal ulceration confirmed by endoscopy after radiotherapy; and ability to tolerate and comply with treatment. Exclusion criteria were: pre-existing nasal mucosal injury prior to radiotherapy; concurrent malignancies; severe systemic diseases; and psychiatric or cognitive disorders that might interfere with cooperation.

Randomization and blinding procedures
Eligible participants were randomly allocated in a 1:1 ratio to the intervention or control group using a computer-generated random sequence created by an independent statistician who was not involved in patient enrollment, intervention delivery, or outcome assessment. Allocation concealment was ensured by the use of sequentially numbered, sealed, opaque envelopes, which were opened only after patient enrollment was completed. Due to the visible differences between the irrigation device and routine manual irrigation, blinding of participants and treating nurses was not feasible. However, outcome assessment was performed under blinded conditions. Two independent otolaryngologists, who were not involved in treatment delivery and were unaware of group allocation, independently evaluated endoscopic mucosal injury grades. Inter-rater reliability was assessed using Cohen's κ statistic, demonstrating excellent agreement (κ > 0.80). Patient-reported outcomes were collected by research staff who were not involved in the intervention procedures.

Sample size calculation
The required sample size was calculated based on the primary outcome of ulcer healing rate between the two treatment groups. Preliminary pilot data suggested an expected healing rate of approximately 70% in the conventional irrigation group and 90% in the improved irrigation group. With a two-sided significance level (α) of 0.05, a power (1-β) of 0.80, and an allocation ratio of 1:1, the minimum required sample size was 82 participants per group. Based on these assumptions, a total of 184 patients (92 per group) were planned and enrolled to ensure sufficient statistical power. The sample size calculation was performed using a standard sample size calculation software based on pilot data.

Study flow and follow-up duration
The overall study process is illustrated in Figure 1. After screening and randomization, baseline demographic and clinical characteristics were collected for all patients. Each treatment course lasted for 8 weeks. Clinical evaluations were conducted at baseline, 1 month, and 2 month after initiation of treatment. The total follow-up duration was 2 months after completion of the intervention. Throughout the study, both groups received standard supportive management, including infection prevention, nutritional counseling, and nasal hygiene education. All interventions were performed by the same team of trained senior nurses to ensure procedural uniformity and reproducibility. To ensure procedural uniformity, all nurses underwent a standardized training workshop before study initiation. A detailed operation checklist was used to verify each procedural step during the 1^st week of intervention. For home-based users, video demonstrations and follow-up audits were employed to ensure consistent technique across sessions.

Device design and operation procedures
The improved position-guided nasopharyngeal irrigation device was developed to enhance precision, safety, and patient comfort during post-radiotherapy care. The device consists of a soft, flexible medical-grade inner catheter (diameter 1.5-2.0 mm, length 8-10 cm) with a rounded atraumatic tip to prevent mucosal injury, a detachable needle-free connector linking the catheter to a sterile saline reservoir, and an adjustable outer sheath that allows directional and depth control for precise targeting of the ulcer surface under endoscopic guidance (Figure 2). A manual pressure-control system, composed of a low-pressure pump or squeeze bulb, allows the operator to adjust irrigation pressure within a low-pressure range of 50-100 mmHg. Irrigation is initiated at the lower end of the range and increased stepwise only if outflow is unobstructed and the patient tolerates the procedure. Pressure is reduced, or the session is discontinued if pain increases, bleeding occurs, or resistance to infusion is encountered. Before each procedure, the system is assembled under aseptic conditions, tested for patency by flushing 10-20 mL of sterile saline, and sterilized by immersion in 75% ethanol for 30 min followed by rinsing with sterile water. The irrigation solution consists of 0.9% sterile saline prewarmed to 35-37 °C to mimic physiological conditions and minimize patient discomfort.

During irrigation, the patient was seated with the head slightly tilted forward and the mouth open to facilitate fluid drainage through the oropharynx and prevent retrograde flow into the Eustachian tubes. Under nasal endoscopic guidance, the catheter was gently inserted through one nostril along the nasal floor to the nasopharyngeal cavity until the tip was positioned directly over the ulcerated mucosa (insertion depth 6-8 cm, individualized according to anatomy). The operator initiated irrigation by gradually compressing the bulb or adjusting the flow valve to achieve a steady, patient-tolerated flow, typically in the range of approximately 10-15 mL/s. Flow was reduced if mucosal sensitivity was high, drainage was suboptimal, or patient discomfort occurred. The irrigation volume was not fixed; a typical session used 300-500 mL of warmed saline, with the initial volume reduced and titrated upward based on secretion burden, endoscopic findings, and patient tolerance. Irrigation was stopped early if predefined stop criteria were met. Patients were instructed to exhale gently through the mouth (ha breathing) during the procedure to allow smooth outflow and reduce nasopharyngeal pressure. Each session lasted approximately 10 min and was performed 3x to 5x daily according to patient tolerance. For home-based irrigation, the initial pressure, flow, and recommended volume range were individualized during supervised training, and patients were instructed not to exceed the preset parameters.

After each irrigation, patients rested for 5-10 min and were advised to avoid nose-blowing or eating for 15 min to allow mucosal healing. The device and accessories were immediately disassembled, rinsed with sterile water, disinfected in 75% ethanol, and air-dried in a sterile environment before reuse. During the 1^st week of therapy, procedures were conducted under direct supervision by an otolaryngology nurse. Once the patient demonstrated correct technique, self-irrigation was performed under periodic nursing oversight. Any discomfort, nasal bleeding, or ear pressure prompted immediate cessation and physician evaluation. This system allows delivery of low-pressure irrigation with defined catheter positioning and continuous outflow, enabling consistent application of the procedure across different clinical settings.

All irrigation procedures were performed under strict aseptic principles. The device components in direct contact with the mucosa were disinfected after each session by immersion in 75% ethanol for 30 min, followed by sterile water rinsing and air-drying in a clean environment. Patients were instructed to replace catheters every 2 weeks and to use sterile saline from single-use containers to prevent contamination. Any signs of secondary infection triggered immediate evaluation and culture-guided therapy.

Waste disposal and environmental decontamination
Collect irrigation effluent in a dedicated disposable container to avoid splashing or aerosol generation. Treat effluent used saline containers, and single-use consumables (e.g., tissues, gauze, gloves, masks) as potentially bio-contaminated waste. In the clinical setting, dispose of these materials according to institutional biosafety and regulated medical waste procedures. For home-based irrigation, patients should seal contaminated disposables in a leak-proof bag and return them to the clinic for appropriate disposal when local regulations do not permit household disposal. After each session, wipe down any contaminated surfaces with a hospital-approved disinfectant and perform hand hygiene after glove removal.

Treatment setting and adherence monitoring
Although all patients were initially enrolled and trained within the inpatient department, the majority of subsequent irrigation sessions were performed at home after standardized instruction. During the 1^st week, patients received device-assisted irrigation under direct supervision by an otolaryngology nurse to ensure correct catheter positioning, pressure control, and aseptic technique. Upon demonstration of adequate proficiency, participants were discharged with the improved irrigation device and a written operation manual. Each patient or caregiver was required to record daily irrigation frequency and any adverse events in a standardized treatment log. Weekly outpatient follow-ups or telemedicine video calls were conducted to verify adherence, review symptom improvement, and provide technical guidance when needed. For patients with severe ulcers or poor self-care ability, short-term hospitalization or day-care observation was arranged to complete part of the treatment under professional supervision. This hybrid inpatient-outpatient model was used to support repeated irrigation sessions while maintaining procedural oversight during the treatment course.

Safety considerations and stop criteria
Nasopharyngeal irrigation in post-radiotherapy patients requires particular caution due to mucosal fragility and bleeding risk. Do not perform irrigation in patients with active bleeding, suspected exposure of major vessels, radiologic or endoscopic concern for internal carotid artery involvement, or deep necrosis with skull-base extension. In these situations, irrigation should be avoided or restricted to clinician-performed sessions with direct visualization and immediate access to hemostatic measures.

During irrigation, stop the procedure immediately if any of the following occur: persistent bleeding, a sudden increase in pain, severe ear fullness or acute otalgia, dizziness, choking or aspiration sensation, visible mucosal tearing, marked resistance to infusion, or failure of outflow drainage. Patients should be instructed to stop irrigation and seek prompt clinical evaluation if bleeding continues for more than 5 min, recurs, or if new neurological symptoms develop.

Controlled pressure and flow refers clinically to maintaining low, steady irrigation sufficient to mobilize secretions and debris without generating forceful jets or causing tissue displacement. If excessive pressure is required, infusion becomes difficult, or drainage is impaired, discontinue irrigation and reassess catheter depth, orientation, and drainage patency before resuming.

Visual checkpoints were used during irrigation to guide continuation or cessation of the procedure. Expected findings allowing continuation included progressive clearance of necrotic debris, thinning of secretions, visualization of pale or pink granulation tissue, and minimal self-limited oozing that resolved spontaneously without accumulation. Acceptable minor findings included transient pinpoint bleeding or mild mucosal hyperemia that diminished within seconds under continued low-pressure flow and unobstructed drainage. These findings did not require termination if patient comfort was maintained and bleeding did not increase. Immediate cessation was required if active bleeding persisted or increased, if fresh pulsatile bleeding was observed, if mucosal tearing or exposed deep tissue planes became visible, or if visualization showed pooling of irrigant without effective outflow. Any sudden obscuration of the field by blood, patient distress, or loss of clear visualization prompted termination and clinical reassessment.

A single irrigation session was considered complete when the planned volume had been delivered or earlier if adequate clearance of debris and secretions was achieved, drainage remained unobstructed, and no stop criteria were triggered. After completion, the patient was required to rest briefly, and no further irrigation was performed during that session. The overall irrigation protocol continued until endoscopic examination demonstrated stable mucosal healing with resolution of active ulceration, or until the predefined treatment course was completed. The protocol was discontinued or escalated to physician-directed management if any of the following occurred: recurrent or worsening bleeding, progressive ulcer enlargement, failure to show clinical or endoscopic improvement over serial assessments, suspected exposure of major vessels, or development of complications requiring endoscopic intervention or hospitalization.

Outcome measures
Outcome evaluation was performed by two independent observers blinded to group allocation. The primary outcome was improvement in nasopharyngeal mucosal injury, assessed after 2months of treatment. Mucosal injury was graded from 0 to IV as follows: Grade 0, normal mucosa with no pain; Grade I, mild congestion and discomfort; Grade II, moderate inflammation and pain; Grade III, severe pain or fibrinous mucositis; and Grade IV, ulceration or bleeding. Grades 0-II were defined as mild, and Grades III-IV as severe^16,17,18.

Secondary outcomes included the viscosity of nasopharyngeal secretions, pain intensity, comfort level, and incidence of adverse reactions. Secretions were graded from 0 (thin, easily removable) to III (dense, adherent)¹⁷. Pain was evaluated using the Visual Analog Scale (VAS), ranging from 0 (no pain) to 10 (worst pain imaginable)¹⁸. Comfort was assessed with the General Comfort Questionnaire (GCQ), encompassing physical, psychological, sociocultural, and environmental dimensions, with higher scores indicating greater comfort¹⁹. Adverse reactions such as nasal dryness, infection, or obstruction were monitored throughout treatment²⁰. All evaluations were performed at baseline, 1 month, and 2 months post-treatment.

Although blinding of participants was not feasible due to the nature of the intervention, outcome evaluation was performed by two independent otolaryngologists blinded to treatment allocation. Pain and comfort scores were collected using standardized questionnaires administered by research staff not involved in treatment delivery.

Safety assessment
Adverse events were recorded and classified as mild, moderate, or severe. Events such as transient bleeding, ear fullness, or discomfort were managed according to institutional clinical protocols. During protocol application, no severe adverse events were documented. Sterilization procedures and patient hygiene instructions were implemented as part of routine infection control measures.

Statistical analysis
Data were analyzed using a standard statistical software package. Continuous variables were expressed as mean ± standard deviation, and categorical variables were summarized as counts and percentages. Between-group comparisons were performed using independent-sample t-tests or the Mann-Whitney U test, as appropriate. Categorical variables were analyzed using the χ² test or Fisher's exact test, and ordinal variables were analyzed using the Wilcoxon rank-sum test. Within-group comparisons were conducted using paired t-tests or the Wilcoxon signed-rank test. Longitudinal outcome data collected at baseline, 1 month, and 2 months were analyzed using predefined pairwise comparisons. Within-group changes over time were assessed by comparing follow-up values with baseline measurements using paired statistical tests. Between-group comparisons were performed at each time point independently to evaluate group differences at baseline, 1 month, and 2 months. No repeated-measures modeling was applied; all time points were analyzed according to the prespecified protocol and outcome definitions. All primary and secondary outcome analyses were performed according to the intention-to-treat (ITT) principle, including all randomized patients regardless of protocol adherence or withdrawal. For patients with missing follow-up data, the last observation carried forward (LOCF) method was applied. A per-protocol analysis was additionally conducted as a secondary analysis, including only patients who completed the assigned intervention as specified in the protocol; missing data in this analysis were handled using multiple imputation. All statistical tests were two-tailed, and a p-value < 0.05 was considered statistically significant. All data were double-entered and independently verified to ensure data accuracy.

Results

Baseline demographic and clinical characteristics demonstrated group comparability
A total of 184 patients diagnosed with RINU secondary to NPC were enrolled between January and March 2025. All participants were randomly assigned in a 1:1 ratio to the control group (routine irrigation, n = 92) or the intervention group (position-guided irrigation, n = 92), completed the 2 month treatment and follow-up, and were included in the final analysis (Figure 1). All randomized pa...

Discussion

This prospective comparative study examined differences in mucosal healing, secretion characteristics, pain scores, and comfort measures between patients receiving position-guided nasopharyngeal irrigation and those receiving conventional manual irrigation. Over an 8 week treatment period, a complete or near-complete mucosal healing rate of 89.1% was observed in the position-guided irrigation group, compared with 69.6% in the routine irrigation group. These findings suggest that a precisely controlled, anatomically guide...

Materials

List of materials used in this article

Name	Company	Catalog Number	Comments
Adjustable outer sheath	Engineering Laboratory, Jiangxi Cancer Hospital, China	JCH-SH-2023	Provides directional and depth control for targeted irrigation
Bacterial culture media (Blood agar, MacConkey agar)	Oxoid, UK	CM0055 / CM0007	For microbiological analysis of secretions
Computer workstation	Lenovo ThinkStation P620	Win10Pro-22H2	Workstation for data processing and analysis
Digital camera system	Sony Medical Imaging, Japan	ILCE-7RM4	Used for image capture of endoscopic and clinical findings
Disposable sterile gloves	3M Healthcare, USA	1860	Used during all irrigation and device handling procedures
Ethanol solution (75%)	Sinopharm Chemical Reagent Co., Ltd., China	10009218	Used for device disinfection
General Comfort Questionnaire (GCQ)	Kolcaba Comfort Research Foundation	RRID:SCR_016653	Validated scale measuring comfort in four domains
GraphPad Prism Version 9.5.1 (733)	GraphPad Software, USA	RRID:SCR_002798	Used for figure plotting and statistical visualization
Improved position-guided nasopharyngeal irrigation device	Engineering Laboratory, Jiangxi Cancer Hospital, China	JCH-PGNI-2023	Double-lumen catheter system with directional tip, adjustable outer sheath, and manual low-pressure pump (50–100 mmHg); reusable after sterilization
Incubator (37 °C)	Thermo Fisher Scientific, USA	51028144	For incubation of bacterial cultures
Manual squeeze bulb / low-pressure pump	Jiangsu Huaxin Medical Equipment Co., Ltd., China	HX-20	Maintains steady irrigation pressure (50–100 mmHg)
Medical-grade flexible catheter (1.5–2.0 mm × 8–10 cm)	Well Lead Medical Co., Ltd., China	880200	Inner catheter with atraumatic rounded tip to prevent mucosal injury
Medical-grade monitor	Philips Healthcare, Netherlands	272B8QJ	Used for endoscopic visualization
Nasal endoscope (0°/30° rigid type)	Karl Storz, Germany	7200AA / 7210AA	Used for visual guidance during irrigation and ulcer assessment
Nasopharyngeal secretion collection swab	Copan Diagnostics, Italy	480CE	Used for bacterial culture sampling
Needle-free connector	BD Medical, USA	302204	Connects irrigation catheter to sterile saline reservoir
PASS Software Version 15.0 (Build 15.0.5)	NCSS LLC, USA	15.0.5	Used for power and sample size analysis
Patient treatment logbook	Clinical Research Documentation Unit, Jiangxi Cancer Hospital	LOG-2023-JCH	Daily record of irrigation frequency and adverse events
SPSS Statistics Version 27.0	IBM Corp., USA	RRID:SCR_002865	Used for statistical analysis and data management
Sterile 0.9% saline solution	Baxter Healthcare, USA	2B1323	Used for irrigation; pre-warmed (35–37 °C)
Sterile drape set	Medline Industries, USA	DYNJP2425	Provides sterile field for nasopharyngeal irrigation
Sterile water	China National Pharmaceutical Group	110125	Used to rinse components after disinfection
Surgical mask	3M Healthcare, USA	1870+	Used to maintain aseptic conditions
Telemedicine video consultation platform	WeDoctor Telehealth Platform, China	v3.2.1	Used for remote follow-up and adherence monitoring
Visual Analog Scale (VAS) Pain Form	Jiangxi Cancer Hospital Clinical Research Unit	RRID:SCR_016655	0–10 scale for subjective pain assessment