Carrier-Assisted Topical Application Versus Intranasal Injection of Autologous Platelet-Rich Plasma for Olfactory Dysfunction: A Randomized Controlled Trial
试验速览
- 阶段
- 3 期
- 状态
- 尚未招募
- 入组人数
- 60
- 试验地点
- 1
- 主要终点
- Sniffin' Sticks Olfactory Test
研究概览
简要总结
The goal of this clinical trial is to determine whether two different delivery methods of autologous platelet-rich plasma (PRP) can improve olfactory function in adults with persistent olfactory dysfunction lasting more than three months. The main questions it aims to answer are:
- Does carrier-assisted topical application of PRP lead to comparable or better improvement in smell function than intranasal injection of PRP?
- Which method provides greater patient comfort and fewer adverse effects?
Researchers will compare carrier-assisted topical PRP application to intranasal PRP injection to see if one approach is more effective in restoring olfactory function.
Participants will:
- Receive a single PRP treatment delivered either by injection or via a PRP-soaked carrier placed into the olfactory cleft.
- Continue daily olfactory training for three months following the intervention.
- Undergo smell testing (Sniffin' Sticks) before and after treatment and complete quality-of-life questionnaires.
详细描述
Persistent olfactory dysfunction (OD) is a common sequela of viral upper respiratory tract infections, including COVID-19, and can significantly affect patients' quality of life, nutrition, and safety. Current treatment options are limited, with olfactory training being the primary evidence-based non-pharmacological therapy. Autologous platelet-rich plasma (PRP) is a concentration of platelets obtained from a patient's own blood, rich in growth factors and cytokines that promote neuronal regeneration, tissue repair, and neuroplasticity. Early clinical studies suggest PRP may improve olfactory function, but the optimal method for delivering PRP to the olfactory cleft remains unknown.
This randomized controlled trial will include a total of 60 adult patients aged 18-80 years old with olfactory loss (hyposmia or anosmia) persisting for more than 3 months despite standardized olfactory training, confirmed by a reduced Sniffin' Sticks TDI score.
PRP will be prepared on-site immediately before application using a standardized centrifugation protocol to achieve a platelet concentration 2-3 times above baseline. efficacy and safety of two PRP delivery methods will be compared:
Intranasal Injection Group: Autologous PRP will be injected directly into the mucosa of the olfactory cleft under endoscopic guidance. After topical anesthesia with lidocaine spray and decongestion with oxymetazoline, a 25-gauge needle will be used to deliver approximately 1 mL of PRP into multiple sites along the superior nasal cavity bilaterally.
Carrier-Assisted Topical Application Group: Four pieces of sterile, bioabsorbable carrier (Gelfoam sponge) will be soaked with approximately 5 mL of autologous PRP. Under endoscopic guidance, two pieces of PRP-soaked carrier will be placed gently into each side of olfactory cleft, ensuring contact with the olfactory mucosa. Carriers will remain in place for a short duration to allow diffusion of PRP before dissolving naturally or being removed.
研究设计
- 研究类型
- Interventional
- 分配方式
- Randomized
- 干预模型
- Parallel
- 主要目的
- Treatment
- 盲法
- Double (Participant, Outcomes Assessor)
盲法说明
Both participants and outcome assessors were blinded to the group assignment to minimize expectation bias. Interventions were prepared using an identical procedure to ensure blinding. The principal investigator, who was responsible for administering the intervention, was aware of group allocation. However, participants and outcome assessors had no access to allocation information throughout the study.
入排标准
- 年龄范围
- 18 Years 至 80 Years（Adult, Older Adult）
- 性别
- All
- 接受健康志愿者
- 否
入选标准
- •Aged between 18 and 80 years, regardless of sex
- •Subjective complaint of olfactory dysfunction with confirmed hyposmia or anosmia based on standardized olfactory testing
- •History of at least 3 months of prior olfactory training but with persistent olfactory complaints
排除标准
- •Congenital anosmia
- •Diagnosed neurological or structural brain abnormalities (e.g., brain tumor, major head trauma, stroke) with low likelihood of olfactory recovery
- •Inability or unwillingness to comply with study procedures or follow-up assessments
研究组 & 干预措施
Topical PRP application arm
Participants in this arm will receive a topical application of autologous PRP delivered via PRP-soaked absorbable material (Gelfoam) placed into the olfactory cleft. No needle will be used. The placement will be guided by nasal endoscopy under local anesthesia. Daily olfactory training will be continued for three months post-application.
干预措施: platelet-rich plasma (Combination Product)
Intranasal PRP injection
Participants in this arm will receive an intranasal injection of autologous platelet-rich plasma (PRP) into the olfactory cleft. The procedure will be conducted under local anesthesia using endoscopic guidance. All participants will also perform standardized daily olfactory training for three months following the intervention.
干预措施: Intranasal Injection of Autologous PRP (Procedure)
Intranasal PRP injection
Participants in this arm will receive an intranasal injection of autologous platelet-rich plasma (PRP) into the olfactory cleft. The procedure will be conducted under local anesthesia using endoscopic guidance. All participants will also perform standardized daily olfactory training for three months following the intervention.
干预措施: olfactory training (Device)
Topical PRP application arm
Participants in this arm will receive a topical application of autologous PRP delivered via PRP-soaked absorbable material (Gelfoam) placed into the olfactory cleft. No needle will be used. The placement will be guided by nasal endoscopy under local anesthesia. Daily olfactory training will be continued for three months post-application.
干预措施: olfactory training (Device)
Topical PRP application arm
Participants in this arm will receive a topical application of autologous PRP delivered via PRP-soaked absorbable material (Gelfoam) placed into the olfactory cleft. No needle will be used. The placement will be guided by nasal endoscopy under local anesthesia. Daily olfactory training will be continued for three months post-application.
干预措施: Carrier-Assisted Topical Application of Autologous PRP (Procedure)
Intranasal PRP injection
Participants in this arm will receive an intranasal injection of autologous platelet-rich plasma (PRP) into the olfactory cleft. The procedure will be conducted under local anesthesia using endoscopic guidance. All participants will also perform standardized daily olfactory training for three months following the intervention.
干预措施: platelet-rich plasma (Combination Product)
结局指标
主要结局
Sniffin' Sticks Olfactory Test
时间窗: pre-intervention and at 1 and 3 months (may extend to 6 and 12 months) post-intervention
The Sniffin' Sticks test (Burghart Messtechnik GmbH, Holm, Germany) comprises three subtests for odor detection threshold (T), odor discrimination (D), and odor identification (I). This test employs odor-containing felt-tip pens, which are presented to participants to evaluate their olfactory performance. In the detection threshold subtest, we employed an adaptive staircase procedure based on a three-alternative forced-choice format. Participants were tasked with differentiating a stick with a rose-like aroma (phenylethyl alcohol) from two blank sticks. Odor discrimination was assessed using 16 pen triplets, two of which contained identical odors and one stick contained a different odor. Participants were tasked with identifying the odd one out. In the odor identification subtest, participants were tasked with naming 16 common odors by selecting appropriate terms from a set of four descriptors per odor. The scores from each subtest were combined into a composite TDI score.
次要结局
- Procedure-related pain evaluation(during the procedure and up to 2 weeks post-intervention)
- Retronasal Olfactory Test(pre-intervention and at 3 months post-intervention)
- Visual Analogus Scale for olfaction(pre-intervention and at 1 and 3 months (may extend to 6 and 12 months) post-intervention)
- Questionnaire of Olfactory Disorders (QOD)(pre-intervention and at 1 and 3 months (may extend to 6 and 12 months) post-intervention)
- Beck Depression Inventory (BDI)(pre-intervention and 3 months post-intervention)
- Montreal Cognitive Assessment (MoCA)(pre-intervention and post-3 month intervention)
- 22-item Sinonasal Outcome Test (SNOT-22)(pre-intervention and at 1 and 3 months (may extend to 6 and 12 months) post-intervention)
- Parosmia Questionnaire (PQ)(pre-intervention and at 1 and 3 months (may extend to 6 and 12 months) post-intervention)
- Sniffin' Sticks Parosmia Test(pre-intervention and 3 months post-intervention)
研究者
Yun-Ting Chao
Dr.
Taipei Veterans General Hospital, Taiwan