Anatomic Variations of the Lacrimal Sac Relative to Middle Turbinate Axilla and Skull Base in Chinese Patients with Nasolacrimal Duct Obstruction: A CT-Dacryocystography

Abstract

Objective

The middle turbinate axilla (MTA) is a crucial anatomical landmark for localizing the lacrimal sac (LS) during endonasal dacryocystorhinostomy (En-DCR). Despite being a standard surgical procedure, En-DCR may lead to severe complications, such as cerebrospinal fluid (CSF) leakage, which is closely associated with anatomical variations between the LS and the anterior skull base (ASB). This study aimed to investigate the anatomical location of the LS relative to the MTA and ASB in Chinese patients with nasolacrimal duct obstruction (NLDO) and analyze the influencing factors.

Methods

This cross-sectional study enrolled 227 Chinese patients who were diagnosed with NLDO and underwent computed tomographic dacryocystography (CT-DCG). Anatomical distances between LS and MTA, as well as LS and ASB, were measured using CT-DCG images.

Results

The mean distances from the superior and inferior edges of the LS to the MTA were 9.94 ± 4.70 mm and − 0.23 ± 4.15 mm, respectively. Male patients showed significantly more superior–anterior displacement of the LS compared to female patients (P < 0.001), while patients with chronic dacryocystitis (CD) had an inferior and posterior LS position relative to those with simple NLDO (P = 0.005, P = 0.001). The mean distance from the intersection (Point P) of the superior and posterior boundaries of the LS to the ASB (MP) was 18.35 ± 4.48 mm, which was shorter in females and those with frontal sinus aplasia (P = 0.001; P < 0.001). A subgroup (28/227, 12.3%) with a critical anatomical feature was identified, where the distance from Point Q (10 mm posterior to P) to the ASB (NQ distance) was ≤ 10 mm. This subgroup had a higher prevalence of complete supra-MTA LS positioning (71.4% vs. 41.2%, P = 0.003).

Conclusion

Preoperative CT-DCG provides essential anatomical insights into the spatial relationship between the LS and MTA in Chinese patients with NLDO. The LS position varies significantly by gender and disease type, with males showing more superior–anterior and CD patients more inferior–posterior positioning relative to the MTA. Special attention should be paid to patients with frontal sinus aplasia or LS entirely above the MTA to minimize the risk of CSF leakage during En-DCR.

Keywords

Middle turbinate axilla (MTA) / Lacrimal sac (LS) / Anterior skull base (ASB) / Cerebrospinal fluid (CSF) leakage / Endonasal dacryocystorhinostomy (En-DCR) / Computed tomographic dacryocystography (CT-DCG) / Nasolacrimal duct obstruction (NLDO) / Chronic dacryocystitis (CD)

References

[1] CuiXH, ZhangLM, QiuJN, et al.. Anatomic characteristics of the lacrimal sac and adjacent bony structures–a computed tomographic-dacryocystography research. Internat J Ophthalmol., 2025, 18(2): 251-257.

[2] OzcelikErdemR, DundarMA, ArbagS, et al.. Endoscopic Anatomy of the Lacrimal Sac: A Cadaveric Study. Acta Med Acad., 2022, 51(3): 175-180.

[3] ShamsPN, WormaldPJ, SelvaD. Anatomical landmarks of the lateral nasal wall: implications for endonasal lacrimal surgery. Curr Opin Ophthalmol., 2015, 26(5): 408-415.

[4] TyagiAK, KurienM, IrodiA, et al.. Meet the Lacrimal Sac: Endoscopic Surgeons' Road Map. Indian J Otolaryngol Head Neck Surg., 2021, 73(1): 18-24.

[5] HashemiSM, BerjisN, EshaghianA, et al.. Applied Endoscopic Anatomical Evaluation of the Lacrimal Sac. Iran J Otorhinolaryngol., 2015, 27(80): 213-217

[6] RajakSN, PsaltisAJ. Anatomical considerations in endoscopic lacrimal surgery. Ann Anat., 2019, 224: 28-32.

[7] LimawararutV, ValenzuelaAA, SullivanTJ, et al.. Cerebrospinal fluid leaks in orbital and lacrimal surgery. Surv Ophthalmol., 2008, 53(3): 274-284.

[8] BadillaJ, DolmanPJ. Cerebrospinal fluid leaks complicating orbital or oculoplastic surgery. Arch Ophthalmol., 2007, 125(12): 1631-1634.

[9] KurihashiK, YamashitaA. Anatomical consideration for dacryocystorhinostomy. Ophthalmologica., 1991, 203(1): 1-7.

[10] CuiX, WangY. Assessing the relationship of agger nasi pneumatization to the lacrimal sac: a dynamic computed tomography-dacryocystography analysis. Quant Imaging Med Surg., 2024, 14(8): 5642-5649.

[11] ÇakurB, SumbulluMA, DurnaNB. Aplasia and Agenesis of the Frontal Sinus in Turkish Individuals: A Retrospective Study Using Dental Volumetric Tomography. Int J Med Sci., 2011, 8(3): 278-282.

[12] PoteetPS, CoxMD, WangRA, et al.. Analysis of the Relationship between the Location of the Anterior Ethmoid Artery and Keros Classification. Otolaryngol Head Neck Surg., 2017, 157(2): 320-324.

[13] AlherabiA, MarglaniO, HerzallahI, et al.. Endoscopic anatomy of the lacrimal sac for dacryocystorhinostomy. A cadaveric study. Saudi Med J., 2017, 38(3): 245-250.

[14] KimYH, ParkMG, KimGC, et al.. Topography of the nasolacrimal duct on the lateral nasal wall in Koreans. Surg Radiol Anat., 2012, 34(3): 249-255.

[15] WangYH, JiangWH, TuYH, et al.. Endoscopic dacryocystorhinostomy with mucosal anastomosing in chronic dacryocystitis with three categories of ethmoid sinuses. Int J Ophthalmol., 2022, 15(11): 1765-1771.

[16] WormaldPJ, KewJ, Van HasseltA. Intranasal anatomy of the nasolacrimal sac in endoscopic dacryocystorhinostomy. Otolaryngol Head Neck Surg., 2000, 123(3): 307-310.

[17] YangL, LiH, YinZ, et al.. Reference role of middle turbinate axilla in lacrimal sac localization assisted by computed tomographic dacryocystography-reference value of middle turbinate in locating lacrimal sac. BMC Ophthalmol., 2022, 221500.

[18] NariokaJ, MatsudaS, OhashiY. Correlation between anthropometric facial features and characteristics of nasolacrimal drainage system in connection to false passage. Clin Exp Ophthalmol., 2007, 35(7): 651-656.

[19] AliMJ. Etiopathogenesis of primary acquired nasolacrimal duct obstruction (PANDO). Prog Retin Eye Res., 2023, 96. 101193

[20] LinZ, KamathN, MalikA. High-resolution computed tomography assessment of bony nasolacrimal parameters: variations due to age, sex, and facial features. Orbit., 2021, 40(5): 364-369.

[21] LeeS, LeeUY, YangSW, et al.. 3D morphological classification of the nasolacrimal duct: Anatomical study for planning treatment of tear drainage obstruction. Clin Anat., 2021, 34(4): 624-633.

[22] WangW, GongL, WangY. Anatomic characteristics of primary acquired nasolacrimal duct obstruction: a comparative computed tomography study. Quant Imaging Med Surg., 2022, 12(11): 5068-5079.

[23] AliMJ, MishraDK, BothraN. Lacrimal Fossa Bony Changes in Chronic Primary Acquired Nasolacrimal Duct Obstruction and Acute Dacryocystitis. Curr Eye Res., 2021, 46(8): 1132-1136.

[24] AvdagicE, PhelpsPO. Nasolacrimal duct obstruction as an important cause of epiphora. Dis Mon., 2020, 6610. 101043

[25] KakizakiH, ZakoM, MiyaishiO, et al.. The lacrimal canaliculus and sac bordered by the Horner's muscle form the functional lacrimal drainage system. Ophthalmology., 2005, 112(4): 710-716.

[26] TakahashiY, SuzukiT, KakizakiH. Lacrimal sac movement under intrasac pressure changes observed with dacryoendoscopy. Ophthalmic Plast Reconstr Surg., 2014, 30(4): 313-314.

[27] FangKC, HoRW, LuoSD, et al.. Sinus Plain Film Can Predict a Risky Distance from the Lacrimal Sac to the Anterior Skull Base: An Anatomic Study of Dacryocystorhinostomy. Diagnostics (Basel)., 2022, 124930.

[28] KonoS, VaidyaA, NaitoM, et al.. Positional relationship between lacrimal sac and skull base: implication of risk of cerebrospinal fluid leakage during dacryocystorhinostomy. Sci Rep., 2022, 12114459.

[29] MassoudVA, FayA, YoonMK. Cerebrospinal fluid leak as a complication of oculoplastic surgery. Semin Ophthalmol., 2014, 29(5–6): 440-449.

[30] AbdullahB, ChewSC, AzizME, et al.. A new radiological classification for the risk assessment of anterior skull base injury in endoscopic sinus surgery. Sci Rep., 2020, 1014600.

[31] James A Stankiewicz, Chow JM. The low skull base-is it important? Curr Opin Otolaryngol Head Neck Surg. 2005;13(1):19–21.

[32] FayetB, RacyE, AssoulineM. Cerebrospinal fluid leakage after endonasal dacryocystorhinostomy. J Fr Ophtalmol., 2007, 30(2): 129-134.

[33] LinZ, KamathN, MalikA. Morphometric differences in normal bony nasolacrimal anatomy: comparison between four ethnic groups. Surg Radiol Anat., 2021, 43(2): 179-185.

[34] ShamsPN, AbedSF, ShenS, et al.. A cadaveric study of the morphometric relationships and bony composition of the Caucasian nasolacrimal fossa. Orbit., 2012, 31(3): 159-161.

[35] Woo KI, Maeng HS, Kim YD. Characteristics of intranasal structures for endonasal dacryocystorhinostomy in Asians. Am J Ophthalmol. 2011;152(3):491–498 e491.

Funding

Natural Science Foundation of Hubei Province(No.2022CFB199)

the National Natural Science Foundation of China(No. 82271127)

RIGHTS & PERMISSIONS

The Author(s), under exclusive licence to Huazhong University of Science and Technology