Toward a Computed Tomography-Based Protocol for Submental Island Flap Vascular Assessment: Clinical Relevance and Research Outlook

1 Clinical Challenges

Since its introduction in 1993, the submental island flap (SIF) has become an established option for head and neck reconstruction^[1]. Its proximity to recipient sites, relative technical simplicity, and favorable donor-site characteristics makes it suitable for oral cavity, oropharyngeal, and pharyngolaryngeal defects. The oncologic safety of the submental region, with low rates of level I lymph node metastasis in pharyngolaryngeal tumors, further supports its use following cancer resection in these contexts^[2].

Despite these advantages, the success of SIF depends on maintaining adequate vascular supply and drainage. Anatomical variations in the submental artery and venous outflow can complicate flap harvest. While the arterial origin is generally consistent, its course relative to the digastric muscle varies. Venous drainage patterns also differ^[3], with outflow directed toward the internal, external, or anterior jugular veins, or combinations thereof. These variations are particularly relevant during neck dissection, where inadvertent injury to dominant venous pathways may compromise flap viability. Preoperative identification of these patterns is therefore important for surgical planning.

2 Current Approaches and Limitations

Preoperative vascular assessment commonly involves Doppler ultrasonography^[4] or computed tomography angiography (CTA)^[5]. Doppler ultrasound provides real-time visualization but is limited by probe-induced vessel displacement, imprecise depth estimation, and positional changes affecting surface markings. CTA offers detailed three-dimensional reconstructions but requires additional radiation exposure, incurs higher cost, and may not be widely available.

Contrast-enhanced computed tomography (CT) is routinely performed for staging head and neck malignancies. However, its potential for vascular mapping has not been fully utilized due to the lack of structured interpretation protocols. Without such guidance, actionable vascular information is often overlooked. This limits the effective use of existing imaging resources for SIF design and harvest.

3 Study Highlights

In this issue of ENT Discovery, Ji and colleagues propose a CT-based protocol for evaluating submental flap vasculature^[6]. A key feature of this approach is the “submental artery triangle”, an anatomical landmark formed by the mandible, mylohyoid muscle, and submandibular gland (See Figure 1A in the original article for a detailed illustration^[6]). This triangle provides a consistent reference for locating the submental artery origin from the facial artery.

The authors reviewed 109 patients (218 sides) and reported:

Submental artery course: Three patterns were identified: deep to the anterior belly of the digastric muscle (31.1%), superficial (33.0%), and penetrating through the muscle (35.9%). These variations have direct implications for flap design: when the artery courses deep or penetrates the digastric muscle, inclusion of the muscle within the flap may be necessary to preserve vascular integrity.

Venous drainage patterns: According to Fang’s classification^[2], Type I drainage (to the internal jugular vein) occurred in 56.3% of cases, Type II (to the external jugular vein) in 32.5%, and Type III (to the anterior jugular vein) in 11.2%. Significant sex-related differences were observed (p \lt 0.001), with Type I more frequent in males and Type II in females.

These findings provide quantitative data on anatomical variability and suggest considerations for individualized surgical planning.

4 Comparative Advantages and Clinical Utility

The proposed protocol offers practical advantages. Unlike Doppler ultrasound, CT-based assessment uses fixed bony landmarks, reducing variability related to operator technique and patient positioning. Compared with CTA, it utilizes imaging already obtained for oncologic evaluation, avoiding additional cost and radiation exposure. The ability to visualize arterial and venous structures in relation to adjacent muscles may improve surgical precision.

In clinical practice, this approach could help anticipate anatomical challenges, guide flap design, and inform strategies for vessel preservation, particularly in cases involving neck dissection. For surgeons with limited experience, preoperative knowledge of vascular patterns may reduce intraoperative uncertainty. Overall, this method represents a step toward more individualized planning for SIF harvest.

5 Limitations and Future Directions

The study is retrospective and includes limited intraoperative validation. The small caliber of the submental artery (approximately 1–2 mm) makes interpretation challenging, and subjective judgment may affect accuracy. Prospective studies correlating CT-based predictions with surgical findings are needed to confirm reliability.

Future work may explore artificial intelligence-assisted pattern recognition and three-dimensional reconstruction to improve performance, efficiency and reproducibility. Combining CT with other modalities, including Doppler ultrasonography or CTA, could enhance diagnostic accuracy in complex cases. Evaluating the impact of these strategies on operative time, complication rates, and long-term outcomes would provide further evidence for clinical adoption.

6 Broader Implications and Conclusion

The approach described in this study illustrates how existing imaging resources can be adapted to support more precise and comprehensive surgical planning. Structured CT interpretation protocols could be extended to other regional flaps^[7], contributing to a broader movement toward image-guided reconstruction. As healthcare systems emphasize safety and cost-effectiveness, such methods warrant further exploration.

In summary, this protocol may offer a practical approach for preoperative assessment of submental flap vasculature. While additional validation is required, the study provides a foundation for integrating structured imaging analysis into routine practice and for future research aimed at improving surgical predictability and outcomes.

References

[1] Martin D , Pascal JF , Baudet J . et al. The submental island flap: a new donor site. Anatomy and clinical applications as a free or pedicled flap.. Plast Reconstr Surg, 1993, 92(5): 867–873

[2] Shi Q , Fang JG , Zhong Q . et al. The significance of preoperative neck enhanced multidetector computed tomography in predicting the recurrent veins and classifying their courses of the submental flap reflux vein for repair in pharyngeal cancer. Chin J Otorhinolaryngol Head Neck Surg, 2025, 60(10): 1208–1214

[3] Aldrich AR , Dorneden AM , Boyd NH , Olson GT , Syme NP . Preoperative Imaging Review Predicts the Complex Venous Anatomy of the Submental Island Flap. Ann Otol Rhinol Laryngol, 2025, 134(12): 900–906

[4] Walczak DAOpyrchał JKrakowczyk Ł, et al. Sonographic Evaluation of the Submandibular Region and Perforators Mapping Before Harvesting a Submental Flap May Reduce Vascular-Related Complications. J Craniofac Surg. Published online 2025.

[5] Ma H , Fang J , Zhong Q . et al. Reconstruction of nasopharyngeal defect with submental flap during surgery for nasopharyngeal malignant tumors. Front Surg, 2022, 9: 985752

[6] Ji Y , He C , Zhou J . et al. Systematic preoperative CT assessment of submental island flap vasculature: Development of a standardized protocol and characterization of anatomical patterns. ENT Discovery, 2025, 1(2): 49–57

[7] Kwek BH , Wain JC , Aquino SL . The radiologic appearance of intercostal muscle flap. Ann Thorac Surg, 2004, 78(2): 432–435

RIGHTS & PERMISSIONS

The Author(s) 2026. This article is available under open access at journal.hep.com.cn.