Journal of Head & Neck Physicians and Surgeons

: 2022  |  Volume : 10  |  Issue : 1  |  Page : 109--111

Platelet rich fibrin for post covid nasal swab cerebrospinal fluid leak

Lalitha Sree1, S Sanooja Pinki2, Felix Vinod1, Senthilkumar Niharika1,  
1 Department of Otorhinolaryngology, KIMS Health, Thiruvananthapuram, Kerala, India
2 Department of Transfusion Medicine, KIMS Health, Thiruvananthapuram, Kerala, India

Correspondence Address:
Lalitha Sree
Department of Otorhinolaryngology, KIMS Health, Anayara PO, Thiruvananthapuram, Kerala


Nasopharyngeal swab collection procedure has been used as a part of COVID-19 testing. Few cases of cerebrospinal fluid (CSF) leak following nasopharyngeal swab have been reported so far. Here, we report an interesting case of CSF leak following nasopharyngeal swab for COVID testing which we repaired using platelet-rich fibrin as an outpatient department procedure.

How to cite this article:
Sree L, Pinki S S, Vinod F, Niharika S. Platelet rich fibrin for post covid nasal swab cerebrospinal fluid leak.J Head Neck Physicians Surg 2022;10:109-111

How to cite this URL:
Sree L, Pinki S S, Vinod F, Niharika S. Platelet rich fibrin for post covid nasal swab cerebrospinal fluid leak. J Head Neck Physicians Surg [serial online] 2022 [cited 2022 Aug 10 ];10:109-111
Available from:

Full Text


The main objective of cerebrospinal fluid (CSF) leak repair is to reduce the risk of meningitis or other intracranial complications. CSF leak is usually repaired in operation theater under general anesthesia using various graft materials such as fascia lata, vascularized mucosal flap, artificial dura, and fibrin glue. Platelet derivatives such as platelet-rich plasma (PRP) and platelet-rich fibrin (PRF) to seal such defect are well described under the scope of regenerative medicine. The utility of those derivatives is found simple and effective and reduces the hospital stay and economic burden to the patient. Herein, we present a case of successful repair of iatrogenic CSF leak endoscopically using PRF in the outpatient department (OPD).

 Case Report

A 62-year-old female, known case of type 2 diabetes mellitus and hypothyroidism, was referred to ENT OPD with complaints of rhinorrhea and headache for a 1-week duration. The nasal discharge was clear watery and unilateral which worsened on leaning forward. Her symptoms started shortly after taking nasopharyngeal swab for COVID-19 testing. She had no associated sneezing, nasal itching, or obstruction, hence allergic rhinitis was ruled out. She was diagnosed with pituitary macroadenoma, for which transnasal transsphenoidal endoscopic excision was done 2 years back and thereafter she had been on regular follow-up.

On physical examination, clear watery discharge was seen leaking out of the right nostril. We suspected CSF rhinorrhoea for the patient and decided to proceed with diagnostic nasal endoscopy to look for the site of CSF leak. DNE showed a defect in the area of Hadad flap (nasal mucosal flap) which was used to cover the dural defect after removal of tumor in the previous surgery. The Hadad flap was pierced by the nasal swab taken during COVID testing resulting in CSF leak [Figure 1]a. As in every case of traumatic CSF leak, we decided to manage the patient conservatively for 10 days expecting spontaneous healing to occur. Ten days later, she came with persistence of the same symptoms and we decided to go for a trial of closure using PRF in OPD itself since the site of defect was clearly visible in DNE. Four-milliliter autogenous blood is collected in a Vacutainer tube without anticoagulant under sterile precautions and is immediately centrifuged at 3000 rpm for 10 min in REMI RC-8C-BL centrifuge to yield around 1 ml of PRF in the middle layer, red cells in the bottom, and supernatant acellular plasma [Figure 2]. PRF is taken out with the help of a sterile bayonet forceps [Figure 3] and is immediately placed endoscopically into the defect to form a uniform layer, which is supported by adhesive gel over it. Under antibiotic cover, the patient was advised strict bed rest and instructed to avoid straining, nose-blowing, and sneezing for a week. Follow-up nasal endoscopy after 1 week and re-evaluation after a month revealed complete closure of the defect [Figure 1]b.{Figure 1}{Figure 2}{Figure 3}


Few cases of iatrogenic CSF leak after a nasal swab for COVID-19 are reported so far.[1],[2],[3] To the best of our knowledge, this is the first case of iatrogenic CSF rhinorrhea following COVID nasal swab repaired using PRF as an OPD procedure.

Concern for CSF leak is significant, as 10%–25% of patients with traumatic CSF leak will develop meningitis.[4] Surgical repair has to be considered if the traumatic CSF leak is not closed within 10 days of conservative management.[5] In this case, the defect was not closed in spite of time given for spontaneous healing.

When nasal swab is taken, the patient's head should be tilted up and rested against a wall (Centers for Disease Control and Prevention recommendation for head tilt is 70°) with swab being inserted parallel to the palate about 2–3 cm until a resistance is met [Figure 4]. If swabs are not directed properly, especially in the patient with a history of skull base surgery, it can result in mucosal damage as well potential damage to the skull base.[4]{Figure 4}

Leukocyte-PRF (L-PRF) is a second-generation platelet derivative[6] with a high potential for tissue regeneration and healing.[5] The autologous bioscaffold is a cocktail of growth factors, leukocytes, stem cells, and cytokines entrapped in a fibrin matrix. The various growth factors released by alpha-granules of the platelets are platelet-derived growth factors, transforming growth factors, vascular endothelial growth factors, and epidermal growth factors. L-PRF promotes and accelerates natural wound healing process by preventing the local recurrence of infections.[7] It also favors microvascularization leading to more efficient cell migration which again enhances healing and regeneration of tissues.[7]

L-PRF was prepared as per the protocol laid down by Joseph Choukron in 2001.[8] It is considered superior to PRP because of its ease of preparation and lack of any external reagents to complement clotting. The concentration of platelet concentrate is also remarkably high in PRF. It is assumed that the junction between red cells and PRF clot has rich growth factors. Centrifugation of Vacutainer tube causes activation of coagulation cascade leading to thrombin generation, which converts fibrinogen to fibrin. The fibrin monomers later polymerize to fibrin mesh which entraps activated platelets leading to release of growth factors and cytokines for at least a week.

This case report suggests that prior nasal or skull base surgeries or pathology that changes normal nasal anatomy may increase the risk of CSF leak associated with nasal swab for COVID-19 [Figure 5]a and [Figure 5]b. Therefore, one should consider alternative methods to nasal swab, like throat swab in patients with known skull base defects, history of sinus, or skull base surgery. Sullivan et al.[1] were the first to report a case of iatrogenic CSF leak after a nasal swab for COVID-19. This report also highlights the role of PRF in CSF leak repair with many advantages including its use on an OPD basis, avoiding general anesthesia to the patient, time-saving as it takes only 10 min for its preparation, autologous, i.e., patients' own blood is used, and more over economically friendly as alternative option is fibrin glue which is costly. Soldatova et al.[9] demonstrated the potential utility of L-PRF membrane for skull base defect reconstruction.{Figure 5}


The case report suggests, if the site of CSF leak is clearly visible, a trail of closure with PRF can be done in the OPD itself. The use of L-PRF in iatrogenic CSF rhinorrhea can be a simple, robust, economical, and effective treatment. It is imperative to consider throat swab in individuals with prior history of skull-based surgeries. The case report emphasizes the importance of proper history taking and awareness of potential complications of improper swab collection.

Declaration of patient consent

The authors certify that they have obtained all appropriate patient consent forms. In the form, the patient has given her consent for her images and other clinical information to be reported in the journal. The patient understands that name and initials will not be published and due efforts will be made to conceal her identity, but anonymity cannot be guaranteed.

Financial support and sponsorship


Conflicts of interest

There are no conflicts of interest.


This material has never been published and is not currently under evaluation in any other peer-reviewed publication.

Ethical approval

The permission was taken from Institutional Ethics Committee before starting the project. All procedures performed in studies involving human participants were in accordance with the ethical standards of the institutional and/or national research committee and with the 1964 Helsinki Declaration and its later amendments or comparable ethical standards.

Informed consent

Informed consent was obtained from the patient included in the study.


1Sullivan CB, Schwalje AT, Jensen M, Li L, Dlouhy BJ, Greenlee JD, et al. Cerebrospinal fluid leak after nasal swab testing for coronavirus disease 2019. JAMA Otolaryngol Head Neck Surg 2020;146:1179-81.
2Ku J, Chen CY, Ku J, Chang HK, Wu JC, Yen YS. Iatrogenic cerebrospinal fluid leak after repeated nasal swab tests for COVID-19: Illustrative case. J Neurosurg Case Lessons 2021;2:CASE 21421. Available from: [Last accessed on 2021 Dec 21].
3Paquin R, Ryan L, Vale FL, Rutkowski M, Byrd JK. CSF leak after COVID-19 nasopharyngeal swab: A case report. Laryngoscope 2021;131:1927-9.
4Rajah J, Lee J. CSF rhinorrhoea post COVID-19 swab: A case report and review of literature. J Clin Neurosci 2021;86:6-9.
5Oh JW, Kim SH, Whang K. Traumatic cerebrospinal fluid leak: Diagnosis and management. Korean J Neurotrauma 2017;13:63-7.
6Miron RJ, Choukroun J, editors. Platelet Rich Fibrin in Regenerative Dentistry: Biological Background and Clinical Indications. Oxford, UK: John Wiley & Sons, Ltd; 2017. Available from: [Last accessed on 2022 Jan 06].
7Fredes F, Pinto J, Pinto N, Rojas P, Prevedello DM, Carrau RL, et al. Potential effect of leukocyte-platelet-rich fibrin in bone healing of skull base: A pilot study. Int J Otolaryngol 2017;2017:1231870.
8Preeja C, Arun S. Platelet-rich fibrin: Its role in periodontal regeneration. Saudi J Dent Res 2014;5:117-22.
9Soldatova L, Campbell RG, Elkhatib AH, Schmidt TW, Pinto NR, Pinto JM, et al. Role of leukocyte-platelet-rich fibrin in endoscopic endonasal skull base surgery defect reconstruction. J Neurol Surg B Skull Base 2017;78:59-62.