Cochlear implantation in the presence of a persistent stapedial artery: surgical technique and systematic review

Introduction

Persistent stapedial artery (PSA) is a rare vascular anatomical variant first identified as early as 1836 with an estimated prevalence of 0.02–0.5% in the general population (1,2). During development the stapedial artery arises from the second branchial arch supplying the majority of the non neural structures of the head. Involution occurs by the tenth week of gestation leaving the obturator foramen of the stapes as the only evidence of its existence. A failure of this regression results in a PSA (3,4). Most often asymptomatic, a PSA encountered during surgery presents significant risks including serious intraoperative bleeding and obstruction of anatomical landmarks (5,6).

We present a case of successful cochlear implantation in a patient with PSA in conjunction with a systematic review of published cases. We will discuss the surgical technique involved, along with review of previously reported cases and common radiological features which may aid in the pre-operative diagnosis of PSA.

Case report

A 76-year-old male presented with significant communication difficulties following an apparent bilateral sudden sensorineural hearing loss four months earlier. He was referred by private otolaryngologist to a cochlear implant clinic for an implant assessment. There were no obvious precipitating factors to the sudden hearing loss. Audiological assessment confirmed a severe to profound hearing loss bilaterally (Figure 1). The patient underwent pre-operative high resolution computed tomography (HRCT) to assess anatomical structure of the middle and inner ear to evaluate candidacy and assist surgical planning. Magnetic resonance imaging of the brain was also completed to exclude any retro-cochlear pathology with no significant findings.

Figure 1 Audiogram indicating profound hearing loss bilaterally.

A standard post-auricular incision was used with cortical mastoidectomy. Post identification of the facial nerve and chorda tympani, a 1 mm posterior tympanotomy was performed with no round window niche observed with suspected adhesions overlying. Bleeding was encountered post adhesion removal and adequately controlled with topical 1:10,000 adrenaline. Further trans-canal approach and posterior canaloplasty was performed in attempt to visualise the round window. Identification of a PSA was made exiting the round window niche with no round window visible (Figure 2). An intraoperative review of the patient’s pre-operative HRCT showed soft tissue within the middle ear cavity and absent foramen spinosum (Figures 3,4). A 1 mm cochleostomy was performed anterior to the PSA with successful insertion of an Advanced Bionics HiRes Ultra 3D Slim J electrode array. Correct anatomical placement was confirmed with an intra-operative X-ray using a modified Stenver’s view along with impedance testing post insertion indicating proper device function and interface within the cochlea.

Figure 2 Intra-operative view of PSA obscuring the round window (red arrow). PSA, persistent stapedial artery.

Figure 3 Soft tissue in the middle ear consistent with PSA (red arrow). PSA, persistent stapedial artery.

Figure 4 Axial view demonstrating the foramen ovale (red arrow) and absence of the foramen spinosum (black arrow) on the side of the PSA. PSA, persistent stapedial artery.

The post-operative course was unremarkable, and the patient was discharged the following day. At the switch-on appointment seven days post-operatively, using a Naída M90 speech processor, the patient scored 100% on a closed-set syllabic recognition task [live voice, audition-alone condition at approximately 65 dB sound pressure level (SPL) at one metre] and 92% on a closed-set multisyllable picture identification task. He correctly identified 6/6 Ling sounds without visual cues. At two months post-implantation, recorded City University of New York (CUNY) sentence testing presented at 65 dB SPL in a sound-treated booth yielded a score of 74% correct.

All procedures performed in studies involving human participants were in accordance with the ethical standards of the institutional and/or national research committee(s) and with the Declaration of Helsinki and its subsequent amendments. Written informed consent was obtained from the patient for the publication of this article and accompanying images. A copy of the written consent is available for review by the editorial office of this journal.

Methods

The study is reported according to the PRISMA reporting guidelines (available at https://www.theajo.com/article/view/10.21037/ajo-25-71/rc). A systematic review was conducted on the 28^th of September 2025 in accordance with the PRISMA 2020 guidelines. A comprehensive search was performed across PubMed, Scopus, and Google Scholar up to September 2025 using the terms, “persistent stapedial artery” AND “cochlear implant”, “stapedial artery” AND “cochlear implantation”.

Inclusion criteria were case reports, case series, or studies describing cochlear implantation in the presence of a PSA, published in English or translation available and full-text accessible. The exclusion criteria were reviews without primary cases, cases of PSA without cochlear implantation and non-human studies.

Two reviewers independently screened titles, abstracts, and full texts. Disagreements were resolved by consensus. Extracted data included: author/year, patient demographics, laterality, surgical approach, radiological findings, intraoperative findings, management, and outcomes.

Results

The systematic review identified 24 articles, of which 4 met inclusion criteria, reporting 4 patients who underwent cochlear implantation in the presence of PSA and outlined in Table 1.

Surgical approaches varied, with cochleostomy anterior to the stapedial artery being the most commonly reported technique, while modified round window approaches were also described. Across all reported cases, cochlear implantation was successfully completed without permanent neurological or vascular complications. Radiological features suggestive of PSA included absent foramen spinosum, abnormal soft tissue traversing the cochlear promontory, and enlargement of the tympanic segment of the facial canal (Table 2). These findings were inconsistently recognised preoperatively, with most PSAs identified intraoperatively.

Our case represents the fifth reported successful implantation and further supports the feasibility and safety of cochlear implantation in this rare anatomical context. The PRISMA flow diagram is presented in Figure 5.

Figure 5 PRISMA flow diagram. PRISMA, Preferred Reporting Items for Systematic Reviews and Meta-Analyses.

Discussion

PSA often presents with clinical symptoms of conductive hearing loss and pulsatile tinnitus, although is commonly a benign vascular anomaly (5,7). Embryologically, the stapedial artery derives from the intra-petrous portion from the internal carotid artery. This gives off a superior and inferior branch, which will develop into the middle meningeal and maxillary artery respectively after the 10^th week of gestation. Failure of stapedial artery regression results in a PSA, replacing the middle meningeal artery and aplastic foramen spinosum on the ipsilateral side (8).

The theoretical complications of damage to a PSA during surgery include facial palsy, hearing loss, hemiplegia or vestibular impairment with traditional management typically being conservative if encountered. However emerging evidence indicates the presence of a PSA should not contraindicate continuation of surgical procedures with no reported cases of post-operative neurological complications seen with transection of the artery (7,9). Injury to a PSA has theoretically been associated with visual complications, including blindness, due to its embryological connection with the carotid-ophthalmic circulation. While no cases of blindness following PSA injury have been reported in cochlear implantation, this potential risk is frequently cited in the literature and warrants acknowledgement (9). Encountering a PSA during cochlear implantation has previously resulted in abandonment of the procedure (10).

Although most commonly discovered during the time of surgery, a review of HRCT imaging may elicit unique features and possible pre-operative diagnosis of PSA. Radiological evidence of PSA may include an absent foramen spinosum, enlarged tympanic segment of the facial canal, and soft tissue traversing the cochlear promontory. Lindemann et al. [2020] indicate that the use of inverted HRCT may offer better visualization of the artery by enhancing edge resolution and contrast from surrounding middle and inner ear structures (3). In our case review, retrospective analysis of pre-operative imaging showed absence of foramen spinosum and soft tissue structure within the middle ear consistent with a PSA (Figure 3).

Although the reported prevalence of PSA is estimated at 0.02–0.5% in the general population, the number of published cases encountered during cochlear implantation is disproportionately low (1). This likely reflects under-recognition on imaging, intraoperative identification without publication, and reporting bias favouring unusual or complicated cases. Consequently, the published literature most likely underestimates the true incidence of PSA encountered during cochlear implantation.

Conclusions

We present this case to add to the growing literature of successful cochlear implantation in cases of PSA. Successful implantation was achieved via a cochleostomy technique. With increasing rates of cochlear implantation globally, pre-operative review of radiological features of PSA may facilitate improved cochlear implantation counselling and surgical planning. It may also aid in decision making for implantation in cases of unilateral PSA evident radiologically prior to surgery. This case adds to the limited but growing literature demonstrating safe outcomes.

Acknowledgments

None.

Footnote

Reporting Checklist: The authors have completed the PRISMA reporting checklist. Available at https://www.theajo.com/article/view/10.21037/ajo-25-71/rc

Peer Review File: Available at https://www.theajo.com/article/view/10.21037/ajo-25-71/prf

Funding: None.

Conflicts of Interest: All authors have completed the ICMJE uniform disclosure form (available at https://www.theajo.com/article/view/10.21037/ajo-25-71/coif). The authors have no conflicts of interest to declare.

Ethical Statement: The authors are accountable for all aspects of the work in ensuring that questions related to the accuracy or integrity of any part of the work are appropriately investigated and resolved. All procedures performed in studies involving human participants were in accordance with the ethical standards of the institutional and/or national research committee(s) and with the Declaration of Helsinki and its subsequent amendments. Written informed consent was obtained from the patient for the publication of this article and accompanying images. A copy of the written consent is available for review by the editorial office of this journal.

Open Access Statement: This is an Open Access article distributed in accordance with the Creative Commons Attribution-NonCommercial-NoDerivs 4.0 International License (CC BY-NC-ND 4.0), which permits the non-commercial replication and distribution of the article with the strict proviso that no changes or edits are made and the original work is properly cited (including links to both the formal publication through the relevant DOI and the license). See: https://creativecommons.org/licenses/by-nc-nd/4.0/.

References

1. LoVerde ZJ, Shlapak DP, Benson JC, et al. The Many Faces of Persistent Stapedial Artery: CT Findings and Embryologic Explanations. AJNR Am J Neuroradiol 2021;42:160-6. [Crossref] [PubMed]
2. Hyrtl J. Über mehrerer im Menschen vorkommende Analogien der jenigen Arterie, welche Otto Bey mehrerer Winterschläfern durch den Steigbügel verlaufend entdeckte. In: Neue Beobachtungen aus dem Gebiete der menschlichen und vergleichenden Anatomie. Med Jahresber Ost Staate 1836;10:457.
3. Lindemann TL, Austin KL, Gadre AK. Successful Cochlear Implantation in the Face of Persistent Stapedial Artery: Surgical Technique and Imaging Features. J Int Adv Otol 2020;16:463-6. [Crossref] [PubMed]
4. Jones H, Hintze J, Gendre A, et al. Persistent Stapedial Artery Encountered during Cochlear Implantation. Case Rep Otolaryngol 2022;2022:8179062. [Crossref] [PubMed]
5. Elazizi DB, Youbi S, Benhoummad O, et al. Uneventful Cochlear Implantation through Round Window Approach in a Child with Persistent Stapedial Artery: A Case Report. SAS J Surg 2023;1:9-12.
6. Dominic M, M M, Mary P, et al. Successful Pediatric Cochlear Implantation In Persistent Stapedial Artery: First Reported Case In India With Literature Review And Relevance of Preoperative Imaging Checklist. Indian J Otolaryngol Head Neck Surg 2024;76:4633-6. [Crossref] [PubMed]
7. Goderie TPM, Alkhateeb WHF, Smit CF, et al. Surgical Management of a Persistent Stapedial Artery: A Review. Otol Neurotol 2017;38:788-91. [Crossref] [PubMed]
8. Nica MI, Cosnard G. Persistent stapedial artery: a congenital anomaly to know. JBR-BTR 2013;96:22-4. [Crossref] [PubMed]
9. Govaerts PJ, Marquet TF, Cremers WR, et al. Persistent stapedial artery: does it prevent successful surgery? Ann Otol Rhinol Laryngol 1993;102:724-8. [Crossref] [PubMed]
10. Wardrop P, Kerr AI, Moussa SA. Persistent stapedial artery preventing successful cochlear implantation: a case report. Ann Otol Rhinol Laryngol Suppl 1995;166:443-5.