The lingual-facial-ascending pharyngeal trunk

Abstract

Though small, the ascending pharyngeal artery (APA) is surgically significant due to its proximity to the internal carotid artery (ICA) and supply to critical neurovascular structures. We present a unique arterial variant identified by computed tomography angiography (CTA) in a 52-year-old male. On the left side, the APA originated in common with a short linguofacial trunk (LFT) that further gave rise to the lingual and facial arteries (LA and FA), forming a trifurcated LA-FA-APA trunk. On the right side, an independent LFT was present, with the APA originating separately from the external carotid artery (ECA). CTA with three-dimensional reconstruction is essential for detecting rare vascular configurations and should be part of the preoperative evaluation for head and neck surgeries and endovascular procedures.

Supplementary Information

The online version contains supplementary material available at 10.1007/s00276-025-03721-w.

Introduction

The external carotid artery (ECA), a branch of the common carotid artery (CCA), supplies vital head and neck structures. Its principal branches include the superior thyroid (STA), lingual (LA), facial (FA), ascending pharyngeal (APA), occipital (OA), posterior auricular, superficial temporal and maxillary arteries. Due to their clinical and surgical relevance, the ECA’s typical and variant branching patterns have been extensively studied [8, 9]. One of the most frequently observed variations is the formation of a linguofacial trunk (LFT), a common origin of the LA and FA, with a pooled prevalence of 16.4% [9].

According to Arterial Variations in Humans by Lippert and Pabst [7], the APA most frequently arises from the ECA (70%) but can also originate from the OA (2%), FA (2%), or, more rarely, the internal carotid artery (ICA) in up to 8% of cases. Despite its small caliber, the APA is clinically significant due to its vascular supply to the lower cranial nerves and the superior cervical ganglion [2]. Its close anatomical relationship with the ICA also poses potential complications during carotid endarterectomy [5]. In the current anatomical-imaging case, we present an unusual variation of the APA origin.

Anatomical variation

During an angiographic study utilizing a computed tomography angiography (CTA) archived dataset, the anatomical characteristics of a 52-year-old male patient were meticulously examined. The imaging data were obtained at the General Hospital of Nikaia–Piraeus and reviewed with institutional ethical approval (protocol number: 56485, approval date: 13 November 2024). The CTA was performed using a helical high-speed, low-dose scanner (SOMATOM go.Top, 128-slice configuration, Siemens) with the patient’s head in the supine neutral position, following the injection of 60 mL of a 30% iodine solution at a flow rate of 4–4.5 mL/s. Post-processing and image review were performed using Horos software (version 3.3.6; Horos Project). For accurate anatomical assessment, multiplanar reconstructions (axial, coronal, and sagittal) and three-dimensional volume renderings were utilized.

On the left side, the STA was the first branch arising from the CCA. A variant fusion into a linguo-facial-ascending pharyngeal artery (LA-FA-APA) trunk was identified 10.4 mm distal to the carotid bifurcation. The common trunk was measuring 3.4 mm long and 3.6 mm in diameter (at its origin). Distally to this variant (4.5 mm), the OA arose (Fig. 1A, C, D and E; Supplementary Video 1).

Fig. 1.

Three-dimensional reconstruction of the computed tomography angiography (CTA) of the male patient (A, B), sagittal slice (C), axial slice (D) and coronal slice (E). On the left side, the common trunk (CT) of the ascending pharyngeal (APA), lingual (LA) and facial arteries (FA) is well-depicted with three-dimensional reconstruction (A). On the right side, the APA is originated just laterally to the linguofacial trunk (LFT) (B). ECA- external carotid artery, ICA- internal carotid artery, CCA- common carotid artery, STA- superior thyroid artery

On the right side, the STA emerged as the first branch of the ECA, just proximal to the carotid bifurcation. The APA arose as the second branch of the ECA, located 5.4 mm distal to the STA. The LA and FA shared a common origin from the ECA. The APA arose independently at a medial position relative to the ECA. The OA was 12.3 mm distal to the APA origin (Fig. 1B, C, D and E; Supplementary Video 2).

Discussion

Only one cadaveric study reported the LFT origin of the APA (LA-FA-APA trunk), and they are summarized in Table 1. Therefore, from the current literature, only Cavalcanti et al. [2] reported only one case of APA origin from the LFT, and notably, it lacked supporting imagery. To the authors’ knowledge, the current case represents the first documented case of APA origin from the LFT with the use of CTA.

Table 1.

Current literature of dissection studies regarding the ascending pharyngeal artery (APA) origin from the linguofacial trunk (LFT)

Authors (Year)	Heminecks (n= )	APA origin from LFT
Cavalcanti et al. (2009) [2]	20	1 case
Al-Rafiah et al. (2011) [1]	60	0
Cobiella et al. (2021) [3]	207	0
Li et al. (2024) [6]	20	0

The bilateral LFT that was observed in the current case was estimated previously with a pooled prevalence of 3.28% [9]. On the left side, it was short (3.4 mm of length) while the pooled mean length was assessed as 9.55 (± 4.39) mm in the previous meta-analysis [9]. Nevertheless, a case of long LFT with a length of 20.9 mm was also reported [10]. In our previous study, we regarded three patients out of 50 LFT cases that shared a common point of origin, like the right side of the current patient [9].

Previous cadaveric studies have recorded different anatomical possibilities of the APA origin, as previously mentioned. The typical configuration from the ECA ranged between 66 and 81% [3]. It typically arises, as a small artery, from the posterior or posterolateral wall of the vessel after the STA and the LA [2]. The origin from branches of the ECA, such as FA and LA, was barely found in the current literature and it could be considered rare variation [2, 3]. During ligation of APA or LA or FA, the presence of variant origins should be considered as a common variation. Tumors located in the pharynx or skull base can be supplied by the APA, while during surgical removal, the ligation should be carefully performed in the respect of the vessel’s origin [3]. When a common trunk is formatted, similar to the current case with LA-FA-APA trunk, it should be encountered preoperatively in order to not ligate unintentionally other vessels. We were able to identify such variant with the use of three-dimensional reconstruction of the CTA.

More concerning are APA variants arising from the ICA, occurring in 1.4–8% of cases [3]. These variants can be surgical hazards during carotid endarterectomy, particularly if missed on preoperative angiography. Cortes-Franco et al. [4] presented three surgical cases of carotid endarterectomy, where the APA was originated from the ICA. Most importantly, they were not able to identify the variation preoperatively using angiogram [4]. They highlighted that very careful surgical dissection should be performed during carotid endarterectomy to avoid injuries of aberrant branches during plaque removal [4]. Nevertheless, the APA can maintain collateral flow to the ICA or vertebral artery territory, and this is another anatomical possibility that should be encountered in case of vessel’s injury [4].

Three-dimensional CTA was essential in identifying the trifurcated LA-FA-APA configuration in our case. The APA arises medially and deep to the ICA—an orientation commonly missed on conventional slices’ imaging.

In summary, we report the common origin of the LA, FA and APA during CTA evaluation of a male patient. This variation was previously reported using cadaveric dissection, while we recorded it with imaging techniques. Careful preoperative evaluation before head and neck surgeries should encounter such unique variants.

Supplementary Information

Below is the link to the electronic supplementary material.

Author contributions

George Triantafyllou – student – project development, data collection and management, statistical analysis, data analysis, and manuscript writing. Panagiotis Papadopoulos-Manolarakis (MD, MSc) – neurosurgeon - data collection and manuscript editing.Rǎzvan-Costin Tudose – student – data analysis and manuscript editing.Mugurel Constantin Rusu (MD, PhD) – professor – data analysis and manuscript editing.George Tsakotos (MD, PhD, MSc) – assistant professor – data analysis and manuscript editing.Maria Piagkou (DDS, MD, PhD, MSc) – professor – supervision, data analysis and manuscript writing.All authors have read and approved the manuscript.

Funding

Open access funding provided by HEAL-Link Greece.

Data availability

No datasets were generated or analysed during the current study.

Declarations

Competing interests

The authors declare no competing interests.

Conflict of interest

The authors declare that they have no conflict of interest.

Ethical approval and consent to participate

The figures were obtained from an archive of the General Hospital of Nikaia-Piraeus after ethical approval (number of approval: 56485; date: 13/11/2024).