A cadaveric study on variations in branching pattern of external carotid artery

Tri-ramification of left external carotid artery associated with anatomical variation of its branches and aneurysm formation

Essential sources of arterial vascularisation in the head and neck region are the left and right common carotid arteries (CCA) and their branches. The left CCA (LCCA) originates from the arch of the aorta and the right CCA originates from the brachiocephalic trunk. In this case report, there was a bilateral higher division of CCA at the plane of the greater cornua of the hyoid bone, unilateral tri-ramification of the LCCA and the left external carotid artery (LECA), and the origin of the linguo-facial trunk and the pharyngo-occipital trunk from the LECA. An aneurysm formed in the distal part of LECA before its termination. In this case, we propose a novel categorization called the punnapatla classification for the anatomical variance branching forms of ECA. These kinds of variations are important to the surgeons, and anaesthetists, during the surgeries of the head and neck.

Bilateral unusual branching pattern of the external carotid artery in a human cadaver

Comprehensive understanding of the variations in the branching of the external carotid artery (ECA) is essential to minimizing vascular complications during cranio-facial and neck surgical procedures. We demonstrate a rare case of unusual branching of ECAs in both carotid triangles and anomalous origin of the left ascending pharyngeal artery (APA) during dissection of embalmed cadaver. The right and left common carotid arteries (CCA) bifurcated at the level of the upper border of the thyroid cartilage. The right superior thyroid artery (STA) originated anterior to the carotid bifurcation (CB), while the left STA originated from the anterior aspect of the left CCA. The right ECA trifurcated into linguofacial trunk, APA, and distal ECA, 15.7 mm from CB. On the left side, lingual artery and APA arose as a short common linguopharyngeal trunk, 1.9 mm from CB. The left facial and occipital arteries originated anteromedially and posteriorly at the same level.

The Diversity of the Linguofacial Trunk

Background and Objectives: Typically, the external carotid artery (ECA) sends off separate anterior branches: the superior thyroid, lingual, and facial arteries. These could, however, form common trunks: thyrolinguofacial, linguofacial (LFT), or thyrolingual. Although known, the LFT variant was poorly detailed previously, and most authors just counted the variant. We aimed to demonstrate the individual anatomical possibilities of the LFT on a case-by-case basis. Materials and Methods: 150 archived angioCT files were used. After applying inclusion and exclusion criteria, 147 files of 86 males and 61 females were kept for this study. Results: In 34/147 cases, LFTs were found (23.12%). Bilateral LFTs were found in 13/34 cases (38.24%) and unilateral LFTs in 21/34 (61.76%) cases. Forty-seven LFTs were thus identified and further studied for different variables. Regarding the vertical topography of LFT origin, type 1a (suprahyoid and infragonial) was found in 28 LFTs (59.57%), type 1b (suprahyoid and gonial) was found in eight LFTs (17.02%), type 3 (suprahyoid and supragonial) was found in two LFTs (4.25%), type 2 (hyoid level of origin) in eight LFTs (17.02%), and type 3 (infrahyoid origin) in just one LFT (2.12%). Types of the initial course of the LFT were determined: type I, ascending, was found in 22/47 LFTs; type II, descending, in 12/47 LFTs; and type III, transverse, in 13/47 LFTs. Regarding the orientation of the first loop of the LFT, 23/47 LFTs had no loop, 4/47 had anterior loops, 1/47 had a posterior loop, 5/47 had superior loops, 5/47 had inferior loops, and 9/47 had medial loops. The position of the LFT relative to the ECA was classified as medial, anterior, or antero-medial. An amount of 12/47 LFTs were anterior to the ECA, 22/47 were antero-medial, 10/47 were medial, 2/47 were inferior, and 1/47 was lateral. Regarding their general morphology, 23/47 LFTs had a rectilinear course, 22/47 had loops, and 2/47 were coiled. A case-by-case presentation of results further demonstrated the diversity of the LFT. Conclusions: In conclusion, the morphology and topography of the LFT are individually specific and unpredictable. It can be anticipated case-by-case by surgeons on CT or MR angiograms.

Is low carotid bifurcation determined by vertebral level always convenient for surgical approach?

Although high-level carotid bifurcation (HCB) could lead to notable surgical difficulty, the definitive reference point for HCB is unclear. HCB is typically characterized as carotid bifurcation (CB) located higher than the level of the third cervical vertebra (C), however, a major obstacle regarding carotid artery surgical exposure is angle of the mandible (AM). The objective of this study was to investigate CB level, define HCB in relation to AM and vertebral levels, and measure the vertical distance from HCB to ipsilateral AM. Moreover, the percentage of surgically challenged CBs, misclassified as low CBs (LCB) based on vertebral level, was investigated. Patients who underwent neck computed tomography angiography were retrospectively studied. HCBs were classified into two categories: CBs above the C3 and either at or above the ipsilateral AM. Of 172 CBs (86 patients; 57 men, 29 women), CB was mostly found at C3 (44.19%), whereas AM was commonly located at C2 (51.16%). Based on vertebral level and AM, HCBs were detected in 10.47% and 20.35% of CBs, respectively. The association of HCBs determined by either C3 or AM between both sides in each individual was nonsignificant (p>0.05), but HCBs determined by C3 level were predominant in women (OR = 3.58, 95%CI = 1.31-9.80). Considering both C3 and AM, there was 8.72% of HCBs. The remaining 91.28% was classified as LCBs, including 11.63% of CBs located at both C3 and AM which were actually classified as HCBs if determined by AM. In cases of CBs above AM level, the mean vertical distance was as high as 6.56 ±2.41mm.

Delineation of Lingual Artery as an Additional Organ-At-Risk for Stereotactic Body Radiation Therapy of Head and Neck Cancers

Lingual artery (LA) stenosis or bleeding can be a potentially fatal consequence of stereotactic body radiation therapy of recurrent head and neck cancer. We aim to provide delineation guidelines for LA contouring during head and neck radiation. Three experienced radiation oncologists and 1 radiologist studied the course of LA and its anatomic relationships. A step-by-step guideline was formulated for its delineation on contrast-enhanced axial computed tomography scans. We recommend that LA should be considered an important organ at risk for stereotactic body radiation therapy of head and neck cancer. Its delineation and dose constraints should be considered on a case-to-case basis.

Morphometric Study and Branching Patterns of External Carotid Artery Using Computed Tomography Angiography Among the South Indian Population: A Retrospective Study

INTRODUCTION

The prime source of vascularization to the head and neck region is through the carotid arteries. The terminal branches of common carotid arteries, such as external carotid artery (ECA) and internal carotid artery (ICA), and their branches are crucial due to the wide area of distribution and variations in their branching pattern. The branching pattern and morphometry are essential for surgeons in the planning and execution of head and neck surgeries. Therefore, this study was conducted to observe the branching patterns of ECA and analyze them morphometrically.

MATERIALS AND METHODS

This retrospective study includes 100 CT images, inclusive of 32 females and 68 males. The branching pattern and luminal diameter of CCA and ECA were measured and analyzed statistically.

RESULTS

The luminal diameter of CCA in males were as follows: 7.4 ± 1.01 (R), 7.1 ± 0.8 (L), and in females: 7.3 ± 0.9 (R), 7 ± 0.9mm (L); and the luminal diameter of ECA in males: 5.2 ± 1.0mm (R), 5.2 ± 0.9mm (L), and in females: 5.0 ± 0.9mm (R), 5.1 ± 1.0mm (L). The level of the carotid bifurcation and ECA branching pattern was observed, and variations were commonly seen in the superior thyroid artery (STA), lingual artery (LA), and facial artery (FA).  Conclusion: The findings of the present study with regard to the external carotid artery and its branching pattern correlate with previous studies. The most common variations were observed in the superior thyroid and lingual and facial arteries. Knowledge about the morphology and branching pattern of the carotid artery is essential for procedures such as intra-arterial chemotherapy, carotid artery stenting, endarterectomy, and extra-intra cranial bypass revascularization procedure where it is harvested as a donor's vessel.

Multidetector computed tomography (MDCT) angiography in the evaluation of external carotid artery

BACKGROUND

Knowledge about anatomical variants of the external carotid artery is crucial in head and neck surgery and interventional technique. This work aimed to present the frequency of regular and another variant of the external carotid artery using 128 multidetector computed tomography (MDCT) angiography.

MATERIALS AND METHODS

This retrospective study included 120 patients in our university hospital between April 2017 and October 2021. They were 65 men and 55 women (mean age, 45.6 years; range, 18-65 years). They were angiofibroma (10 patients), cerebral stroke (28 patients), partial glossectomy (13 patients), submandibular gland excision (12 patients), parotidectomy (17 patients), mandibulectomy (5 patients), and a thyroidectomy (35 patients). We retrospectively analyzed the level and branches of external carotid arteries on both sides of 120 patients.

RESULTS

According to the level of bifurcation; the external carotid artery originated at the level of the upper border of the thyroid cartilage in 164/240 cases (68.3%), and a higher level was detected in 76/ 240 cases (31.7%). The lower level of origin of the external carotid artery was not detected. The superior thyroid, facial, and lingual arteries originated from separate branches of external carotid arteries in 173/240 cases (72.1%). At the same time, the facial arteries originated with lingual arteries in a common trunk in 67/240 cases (27.9%).

CONCLUSION

MDCT angiography is a valuable noninvasive diagnostic tool for evaluating the external carotid artery and its branches.

Geometric morphometric study of anterior branches of external carotid artery and carotid bifurcation by 3D-CT angiography

PURPOSE

The aim of our study was to determine the variations of the anterior branches of the external carotid artery (ECA) and investigate the morphometric and geometric features of the anterior branches of the ECA and carotid bifurcation (CB).

METHODS

A total of 563 ECAs were included from 288 patients in the study. Classification and exit angles of anterior branches of ECA and determination of vertebral levels of CB and anterior branches were performed.

RESULTS

The anterior branch variants of the ECA were observed in 8 different subgroups. The most common variations were type Ia 42.3% (n = 120) on the right and type Ib 40.9% (n = 114) on the left. When looking at the vertebral levels, CB was detected at C4 level in 32.9% of total ECAs (n = 185), STA was at C4 level in 33.4% of total ECAs (n = 188), LA was at C3 level in 50.1% of total ECAs (n = 282), and FA was at C2 level in 37.3% of total ECAs. The mean CB angle in all cases was 59.93° ± 16.04. In the anterior branches of the ECA in cases belonging to the Type I group, the widest angle belonged to FA (R = 116.88 ± 27.04°, L = 110.32° ± 25.94).

CONCLUSION

In conclusion, a new classification of the variations of the anterior branches of the ECA was made on the basis of the CTA images to gain more practicality in surgical procedures. This study revealed for the first time the angular and level relationship between CB and ECA anterior branches.

A novel technique of arterial blood flow modification in intra-arterial chemoradiotherapy of maxillary sinus squamous cell carcinoma

OBJECTIVES

Intra-arterial chemoradiotherapy via a superficial temporal artery is reportedly a useful organ-preserving treatment for maxillary sinus squamous cell carcinoma. This study aimed to determine whether blood flow modification facilitates sufficient drug delivery to the entire carcinoma via the maxillary artery alone, even for advanced tumors.

MATERIALS AND METHODS

A retrospective study of 10 patients who were diagnosed with locally advanced carcinoma (4 [40%] at stage T3, 5 [50%] at T4a, and 1 [10%] at T4b) from August 2016 to July 2018, with tumor blood flow from both the maxillary and facial arteries, was conducted. Patients underwent intra-arterial chemoradiotherapy, which involved chemotherapy with weekly cisplatin administration (40 mg/m2) and radiotherapy (70 Gy/35 fr), with facial artery ligation. The success rate of blood flow modification, as well as its therapeutic effects and safety, were evaluated, with a median follow-up period of 14.4 months (range: 12.3-35 months).

RESULTS

The blood flow surrounding the tumor was changed from both the maxillary and facial arteries to the maxillary artery alone in all patients. A median of 9 chemotherapy courses (range: 8-10) were administered; the median total cisplatin dose was 350 mg/m2 (range: 320-360 mg/m2). Radiotherapy of 70 Gy/35 fr was used to treat all patients. Grade 3 oral mucositis (80%) and irradiation field dermatitis (40%) were observed. In all patients, complete response was achieved, and local recurrence was not observed for at least 1 year.

CONCLUSION

Simplifying the blood flow around the tumor facilitates more standardized intra-arterial chemoradiotherapy via a superficial temporal artery procedure.

Anomalous Course of Facial Artery Through the Submandibular Gland and its Redundant Loop at the Base of Mandible

Knowledge of variant course and branching pattern of the facial artery gains importance in the surgeries of upper neck and face. The authors report a unilateral anomalous course and a redundant loop of right facial artery as seen in an adult male cadaver. The right facial artery had its origin from the external carotid artery. It pierced through the submandibular salivary gland and formed a redundant loop at the base of the mandible. Its further course and branching pattern was normal. This case could be important for radiologists, plastic surgeons and craniofacial surgeons.

A Completely Unique Branching Pattern of the Facial Artery

This case report describes a recent case where a patient with hypopharyngeal cancer underwent resection and reconstruction with a free jejunum flap and the surgeons found a rare variation in the branching pattern of the common carotid artery. Specifically, the left facial artery arose directly from the common carotid artery, whereas the left superior thyroid artery arose from the facial artery. This branching pattern has not been reported previously. Although this is a hitherto unique case, head and neck and reconstructive surgeons should be aware of the possibility that this branching pattern may be present because it could complicate the outcomes of both neck dissection and reconstruction by free tissue transfer.

Do Asians have Higher Carotid Bifurcation? A Computed Tomographic Angiogram Study of the Common Carotid Artery Bifurcation and External Carotid Artery Branching Patterns

Introduction:

Carotid endarterectomy is a major treatment modality for high-grade carotid stenosis. Preoperative identification of the level of the carotid bifurcation and its branching pattern is important in planning for adequate exposure and cross-clamping to achieve hemostasis during the procedure. Most of the previous studies on carotid arteries were performed in cadavers.

Methods:

We studied levels of carotid bifurcation compared relatively with the level of the vertebral body and ipsilateral angle of the mandible and its branching pattern using computed tomographic angiogram (CTA) carotid with multiplanar reconstruction and three-dimensional imaging in 100 CTA studies.

Results:

Most of the carotid bifurcations were located at the level of C3–C4 vertebral body and 12% were considered to be high bifurcation. Carotid bifurcations were located below the angle of the mandible in 83.5%. The superior thyroid, facial, and lingual arteries arose from separate branches of external carotid arteries in 67.7% of samples. Facial arteries arose in common trunk with lingual arteries in 29.2%, much more common than previous cadaveric studies. The lingual arteries arose with superior thyroid arteries in 2%, while occipital arteries had high variations in their branching patterns.

Conclusions:

CTA is an effective and reliable modality for preoperative evaluation of the carotid system in patients undergoing carotid endarterectomy and other carotid procedures. Higher percentage of high carotid bifurcation was found in our study, concordant with other Asian cadaveric studies. We assumed that carotid bifurcation of Asian tends to be located slightly higher than those of the Caucasian population.