External versus endoscopic dacryocystorhinostomy for acquired nasolacrimal duct obstruction: outcomes from a Mexican tertiary eye hospital

External versus endoscopic dacryocystorhinostomy for acquired nasolacrimal duct obstruction: outcomes from a Mexican tertiary eye hospital | Research Square window.SnipcartSettings = { analytics: { enabled: false } }; (function() { var accessVector = localStorage.getItem('access_vector') || ''; window.dataLayer = window.dataLayer || []; if (accessVector) { window.dataLayer.push({ user: { profile: { profileInfo: { snid: accessVector } } } }); } })(); (function(w,d,s,l,i){w[l]=w[l]||[];w[l].push({'gtm.start':new Date().getTime(),event:'gtm.js'});var f=d.getElementsByTagName(s)[0],j=d.createElement(s),dl=l!='dataLayer'?'&l='+l:'';j.async=true;j.src='https://www.googletagmanager.com/gtm.js?id='+i+dl;f.parentNode.insertBefore(j,f);})(window,document,'script','dataLayer','GTM-K279D39R'); Browse Preprints In Review Journals COVID-19 Preprints AJE Video Bytes Research Tools Research Promotion AJE Professional Editing AJE Rubriq About Preprint Platform In Review Editorial Policies Our Team Advisory Board Help Center Sign In Submit a Preprint Cite Share Download PDF Research Article External versus endoscopic dacryocystorhinostomy for acquired nasolacrimal duct obstruction: outcomes from a Mexican tertiary eye hospital Carlos Martínez-Molina, Humberto López-García, Erick Domínguez-Hernández, and 1 more This is a preprint; it has not been peer reviewed by a journal. https://doi.org/ 10.21203/rs.3.rs-7782679/v1 This work is licensed under a CC BY 4.0 License Status: Under Review Version 1 posted 6 You are reading this latest preprint version Abstract Purpose: To compare surgical outcomes and complications of external versus endoscopic dacryocystorhinostomy (DCR) in patients with acquired nasolacrimal duct obstruction (ANDO) treated at a tertiary referral eye hospital in Mexico. Methods We conducted a retrospective, single-center, comparative study of patients undergoing external or endoscopic DCR treated between January 2019 and December 2024. Surgical success was defined as resolution or improvement of epiphora with a patent lacrimal irrigation at 6-month follow-up. Demographic variables, comorbidities, surgical technique, and complications were recorded and analyzed using Welch’s t-test and Fisher’s exact test. Results A total of 255 patients were included (mean age: 40 years in the endoscopic group, 57 years in the external group; p = 0.005). Female predominance was observed in both groups. Success rates were 100% for both techniques on day 1, and remained above 95% at 3 months. At 6 months, success was 95.7% for endoscopic DCR and 92.2% for external DCR; no statistically significant difference was found (p > 0.05). Complication rates were low in both groups (4.2% in endoscopic vs. 2.2% in external), mainly tube extrusion and local infection. No risk factors for failure were identified. Conclusions Both external and endoscopic DCR achieved high and comparable success rates with few complications in this large single-center cohort. These findings support the use of both techniques and provide valuable data from Latin America to complement global evidence on the surgical management of ANDO. dacryocystorhinostomy nasolacrimal duct obstruction endoscopic DCR external DCR lacrimal surgery Introduction Acquired nasolacrimal duct obstruction (ANDO) is a common cause of epiphora in adults and significantly impacts daily activities and quality of life. Up to 30–40% of elderly individuals may present with some degree of lacrimal drainage dysfunction, with ANDO being more prevalent among women and frequently associated with chronic inflammation, fibrosis, trauma, or sinonasal comorbidities [ 1 – 3 ]. The standard treatment is dacryocystorhinostomy (DCR), which creates a permanent bypass between the lacrimal sac and nasal cavity, with long-term success rates consistently exceeding 90% [ 1 , 4 , 5 ]. The endoscopic approach, reintroduced with the advent of modern nasal endoscopy, offers potential advantages such as the absence of cutaneous scar and preservation of the orbicularis pump function. However, its reported success rates vary widely, ranging from 70% to 95%, depending on surgical expertise and patient selection; factors such as age, sex, diabetes mellitus have been proposed as predictors of failure [ 4 – 11 ]. Several comparative studies and meta-analyses have reported similar outcomes between external and endoscopic DCR, although external DCR often maintains slightly higher success rates in long-term follow-up [ 10 , 12 ]. Despite abundant evidence from Europe, Asia, and the Middle East, data from Latin America are scarce. To date, no large comparative cohort of external versus endoscopic DCR has been reported from Mexico. The aim of this study was to compare the success rates and complications of external and endoscopic DCR performed at a tertiary referral eye hospital in Mexico, analyzing a large retrospective cohort with standardized follow-up, providing regional data to complement international evidence. Methods Study design and setting This retrospective, longitudinal, comparative cohort study was conducted at Fundación Hospital Nuestra Señora de la Luz, a tertiary referral eye hospital in Mexico City. Medical records of patients who underwent external or endoscopic dacryocystorhinostomy (DCR) between January 2019 and December 2024 were reviewed. Participants Eligible patients included all individuals diagnosed with acquired nasolacrimal duct obstruction (ANDO) who underwent either external or endoscopic DCR at the Department of Orbit and Oculoplastic during the study period. Inclusion criteria were: age without restriction, diagnosis of ANDO confirmed clinically, surgery performed by the institutional oculoplastic team and minimum postoperative follow-up of six months. Exclusion criteria were: prior lacrimal surgery performed at another institution, incomplete records, concomitant procedures on the same side during surgery and loss to follow-up before six months. Surgical techniques External DCR was performed through a cutaneous incision with bony ostium creation, lacrimal sac opening, and mucosal flap anastomosis, followed by silicone intubation. Endoscopic DCR was carried out under direct nasal endoscopic visualization with removal of the overlying lacrimal bone, identification and incision of the lacrimal sac and mucosal flap marsupialization, and silicone intubation. Both procedures were performed according to institutional protocols. Data collection Demographic data (age, sex), clinical variables (laterality, comorbidities), surgical details, postoperative findings, and complications were retrieved from the electronic medical record system. All data were anonymized and handled in compliance with the Declaration of Helsinki and institutional Review Board and Ethics Committee before analysis. The requirement for individual informed consent was waived due to the retrospective nature of the study and anonymization of patient data. Surgical success at six months, was defined as resolution or improvement of epiphora combined with a patent lacrimal irrigation test. Failure was defined as persistent epiphora, absence of irrigation patency, or the need for reoperation. Secondary outcomes included early success (day 1, month 3), perioperative complications, and additional potential risk factors (laterality, comorbidities). Statistical analysis Continuous variables were summarized as means ± standard deviation (SD), and categorical variables as frequencies and percentages. Group differences were analyzed using Welch’s t-test for continuous data and Fisher’s exact test for categorical variables. Statistical significance was set as p < 0.05. Analyses were performed using SPSS version 25.0 (IBM Corp., Armonk, NY). Results Patient characteristics A total of 255 patients met the inclusion criteria: 24 underwent endoscopic DCR and 226 external DCR. The endoscopic group included significantly younger patients (mean age 40 ± 27 years) compared with the external group (57 ± 21 years, p = 0.005, Welch’s t-test) (Table 1 ). Female predominance was observed in both groups (62.5% endoscopic vs 82.3% external). Laterality was evenly distributed (Table 1 ). Table 1 Demographic and clinical characteristics of patients undergoing DCR Variable Endoscopic DCR (n = 24) External DCR (n = 231) p-value Age, years (mean ± SD) 40 (± 27) 57 (± 21) 0.005* Sex Female 15 (62.5%) 190 (82.3%) 0.07 Male 9 (37.5%) 41 (17.7%) Laterality (right 0.91 Right 14 (58.3%) 132 (57.1%) Left 10 (41.7%) 99 (42.9%) *Welch´s t-test. Other comparisons by Fisher-s exact test. Media (DE) o Frecuencia (%) Welchs t-test. Success rates Both surgical techniques demonstrated high early success rates. On postoperative day 1, success rates were 100% for both external and endoscopic DCR. At 3 months, success remained above 95% in both groups. By 6 months, success was 95.7% for the endoscopic group and 92.2% for the external group. Statistical comparison using Fisher’s exact test revealed no significant difference between groups (p > 0.05) (Table 2 ). Overall, both techniques demonstrated stable outcomes over time, with no trend toward decline in patency at mid-term follow-up. Table 2 Surgical success rates of DCR at different follow-up points Follow-up time Endoscopic DCR n (%) External DCR n (%) p-value Day 1 23 (100) 231 (100) - 1 week 23 (100) 230 (99.6) 1 month 23 (100) 223 (96.5) 3 months 23 (100) 221 (95.7) - 6 months 22 (95.7) 213 (92.2) > 0.05* *Fisher-s exact test. Postoperative complications Complications were infrequent and minor, occurring in 1 (4.2%) endoscopic and 5 (2.2%) external cases (Table 3 ). The most frequent event was tube extrusion, in external DCR. No major complications such as orbital cellulitis, hemorrhage, or nasal bleeding were recorded. Most patients (95.8% in the endoscopic and 97.8% in the external group) had an uncomplicated postoperative course. Table 3 Postoperative complications Complication type Endoscopic DCR n (%) External DCR n (%) Total n (%) Tube extrusion 1 (4.2) 3 (1.3) 4 (1.6) Wound infection 0 1 (0.4) 1 (0.4) Infection with wound dehiscence 0 1 (0.4) 1 (0.4) Total 1 (4.2) 5 (2.2) 6 (2.4) Risk factors for surgical failure Exploratory analysis using Fisher’s exact test did not identify any significant predictors of failure. Age group ( 0.05 for all comparisons). The low number of failures limits further multivariate analysis. Discussion Both external and endoscopic DCR approaches achieved high success rates (> 90% at 6 months), with no statistically significant difference. These findings contribute to the global evidence base by providing real-world data from Latin America, a region with limited published series on DCR outcomes. Our findings align with the established literature reporting external DCR success rates consistently above 90% [ 4 , 14 ]. Endoscopic DCR outcomes in this series (95.7% at six months) fall within the upper range of international reports, where success rates vary between 73% and 95% depending on surgical expertise and adjunctive measures [ 9 , 11 ]. Large comparative series from Turkey [ 5 ], India [ 13 ], and Europe [ 15 ] also reported comparable outcomes, reinforcing the robustness of our results. Several systematic reviews and meta-analyses support these observations. An evidence-based review by the American Academy of Ophthalmology concluded that external DCR may provide slightly higher long-term success, but both approaches are highly effective in experienced hands [ 7 ]. A recent Cochrane-style systematic review confirmed no significant difference in outcomes when techniques were standardized [ 17 ]. Additional meta-analyses reported similar success when mitomycin C, stenting, or powered instrumentation were applied [ 18 – 20 ]. Studies from diverse regions align with our results. Rajabi et al. [ 9 ] in Iran and Jawad et al. [ 11 ] in Pakistan reported no significant differences between external and endoscopic DCR, with success rates above 90% at mid-term follow-up. In Israel, Cohen et al. [ 10 ] demonstrated long-term success for endoscopic DCR (86% at 5 years and 80% at 10 years). In Korea, Yun et al. [ 12 ] showed that age influenced outcomes, with lower success in elderly patients undergoing endoscopic DCR. Similarly, Tessler et al. [ 21 ] found external DCR remained highly effective in geriatric populations, supporting its use as a first-line procedure in older adults. Unlike prior studies that identified age, male sex, diabetes mellitus, or sinonasal pathology as risk factors for failure [ 5 , 10 , 12 , 13 , 21 – 23 ], our series did not detect significant associations. This discrepancy may reflect the limited number of failures observed in our cohort, or differences in population characteristics. Learning curve has also been emphasized as a determinant of outcome in endoscopic DCR, with some authors suggesting that at least 30 procedures are needed to achieve stable success rates [ 15 , 20 ]. Complications in our cohort were rare and minor, consistent with international experience [ 11 , 13 , 15 , 22 ]. Tube extrusion was the most frequent, followed by isolated wound infections in external cases. Previous reports describe similar complication profiles, with hemorrhage and sump syndrome being more frequent in endoscopic cases, while scarring and cutaneous issues remain specific to external DCR [ 9 , 17 , 25 ]. Importantly, no major orbital or systemic complications occurred, underscoring the safety of both techniques in specialized centers. This study contributes with one of the first large comparative datasets on DCR from Latin America (255 cases), standardized surgical protocols, and systematic follow-up at six months. To our knowledge, this is the first comparative cohort study of DCR techniques reported from Mexico, contributing valuable data from Latin America. Previous regional reports have been limited to small series or single-technique series. For example, Pablos-Buitrón et al [ 24 ] in Mexico reported an 83.5% success rate in 172 cases of endoscopic DCR, confirming the reliability of the endonasal approach within the Latin American surgical context. Similarly, Feijó et al [ 25 ] in Brazil described long-term outcomes of diode laser DCR with comparable success and safety, reinforcing that endoscopic approaches remain effective and reproducible across different healthcare systems in the region. Together, these findings demonstrate that surgical results in Latin America are comparable to those from high-volume centers in Europe and Asia [ 5 , 9 , 10 , 13 , 15 , 21 , 25 ]. Limitations include its retrospective design, unequal distribution between groups (with external DCR predominating), and lack of standardized patient-reported outcome measures such as quality-of-life questionnaires. Additionally, the six-month follow-up, though clinically meaningful, may underestimate late failures observed in long-term series [ 12 , 21 , 23 ]. Future prospective, multicenter studies with longer follow-up and patient-reported outcomes are warranted. Conclusion Our findings support that both external and endoscopic DCR remain safe and highly effective options for ANDO. External DCR continues to be reliable, particularly in elderly patients, whereas endoscopic DCR offers cosmetic and sinonasal advantages. Surgical expertise and institutional resources should guide the choice of technique. By contributing one of the first large comparative datasets from Latin America, this study expands the global evidence base and supports the equivalence of both procedures in routine clinical practice. Declarations Authors’ contributions [Martínez-Molina CA]: Study conception and design, data collection, data analysis, manuscript drafting. [López-García H]: Data collection, data analysis, critical revision of manuscript. [Domínguez-Hernández ED]: Statistical analysis, interpretation of results. [Parra F]: Study conception and design, data collection, data analysis, supervision. All authors read, commented and approved the final version of the manuscript. Funding This research received no specific grant from any funding agency in the public, commercial, or not-for-profit sectors. Conflicts of interest The authors declare that they have no conflicts of interest related to this work. Consent to participate The requirement for informed consent was waived due to the retrospective design of the study and anonymization of patient data, in accordance with institutional and national regulations. Availability of data and materials The datasets generated and/or analyzed during the current study are available from the corresponding author upon reasonable request. References Makselis A, Petroskas D, Kadziauskiene A et al. Acquired nasolacrimal duct obstruction: clinical and histological findings of 275 cases. BMC Ophthalmol. 2022;22(1):359. doi:10.1186/s12886-022-02590-4 Yim M, Wormald PJ, Doucet M et al. Adjunctive techniques to dacryocystorhinostomy: an evidence-based review with recommendations. Int Forum Allergy Rhinol. 2021;11(5):885–93. doi:10.1002/alr.22699 Ulrich K, Malhotra R, Patel B. Nasolacrimal duct obstruction. In: StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing; 2022. Sobel RK, Aakalu VK, Wladis EJ, Bilyk JR, Yen MT, Mawn LA. 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Functional outcomes after dacryocystorhinostomy: a large cohort from India. Orbit. 2019;38(2):133–9. doi:10.1080/01676830.2018.1479748 Ali MJ. Dacryocystorhinostomy: from evolution to revolution. Saudi J Ophthalmol. 2021;35(3):213–9. doi:10.4103/1319-4534.327993 Leong SC, MacEwen CJ, White PS. A systematic review of outcomes after dacryocystorhinostomy in Europe. Clin Otolaryngol. 2020;45(5):605–12. doi:10.1111/coa.13550 Smith J, Hussain R, Mahroo O et al. Endoscopic versus external dacryocystorhinostomy: Cochrane-style systematic review. Int Forum Allergy Rhinol. 2021;11(9):1432–40. doi:10.1002/alr.22781 Baldeschi L, Hintschich CR. Adjunctive measures in endoscopic dacryocystorhinostomy: systematic review and consensus. Orbit. 2022;41(2):113–21. doi:10.1080/01676830.2021.1964642 Liang J, Hur K, Stokken J, et al. Endoscopic versus external dacryocystorhinostomy: a meta-analysis of randomized controlled trials. Otolaryngol Head Neck Surg. 2020;162(2):229–36. doi:10.1177/0194599819875852 Heichel J, Struck HG. Adjunctive mitomycin C in endoscopic dacryocystorhinostomy: a systematic review. Graefes Arch Clin Exp Ophthalmol. 2019;257(8):1615–22. doi:10.1007/s00417-019-04368-0 Tessler I, Warman M, Amos I et al. Endoscopic dacryocystorhinostomy among the old and oldest-old populations: a case-control study. Auris Nasus Larynx. 2021;48(2):273–8. doi:10.1016/j.anl.2020.09.004 Keren S, Abergel A, Manor A et al. Endoscopic dacryocystorhinostomy: reasons for failure. Eye (Lond). 2020;34(5):948–53. doi:10.1038/s41433-019-0600-3 Mandal P, Ahluwalia H. Do topical ocular antihypertensives affect dacryocystorhinostomy outcomes? Eye (Lond). 2022;36(1):135–9. doi:10.1038/s41433-021-01463-3 Wormald PJ, Tsirbas A. Powered endoscopic dacryocystorhinostomy. Laryngoscope. 2020;130 Suppl 7:S1–10. doi:10.1002/lary.28389 Pablos-Buitrón E, Martínez-Morán A, Lage-Fernández J, Cerdeira-Pena P, Pérez-Varela V. Endoscopic dacryocystorhinostomy. Results in 172 patients. Rev Mex Oftalmol. 2021;95(4):137–141. doi:10.24875/RMOE.M21000173 Feijó ED, Fernandes RM, Silva Júnior A, Neves MC, Pinto JM. Long-term outcomes of modified transcanalicular diode laser dacryocystorhinostomy in a large cohort. Arq Bras Oftalmol. 2024;87(5):e0024. Doi:105935/0004-2749.20240024 Additional Declarations No competing interests reported. Cite Share Download PDF Status: Under Review Version 1 posted Reviews received at journal 23 Nov, 2025 Reviewers agreed at journal 13 Nov, 2025 Reviewers invited by journal 12 Nov, 2025 Editor assigned by journal 06 Oct, 2025 Submission checks completed at journal 06 Oct, 2025 First submitted to journal 05 Oct, 2025 You are reading this latest preprint version Research Square lets you share your work early, gain feedback from the community, and start making changes to your manuscript prior to peer review in a journal. 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Up to 30\u0026ndash;40% of elderly individuals may present with some degree of lacrimal drainage dysfunction, with ANDO being more prevalent among women and frequently associated with chronic inflammation, fibrosis, trauma, or sinonasal comorbidities [\u003cspan additionalcitationids=\"CR2\" citationid=\"CR1\" class=\"CitationRef\"\u003e1\u003c/span\u003e\u0026ndash;\u003cspan citationid=\"CR3\" class=\"CitationRef\"\u003e3\u003c/span\u003e].\u003c/p\u003e\u003cp\u003eThe standard treatment is dacryocystorhinostomy (DCR), which creates a permanent bypass between the lacrimal sac and nasal cavity, with long-term success rates consistently exceeding 90% [\u003cspan citationid=\"CR1\" class=\"CitationRef\"\u003e1\u003c/span\u003e, \u003cspan citationid=\"CR4\" class=\"CitationRef\"\u003e4\u003c/span\u003e, \u003cspan citationid=\"CR5\" class=\"CitationRef\"\u003e5\u003c/span\u003e]. The endoscopic approach, reintroduced with the advent of modern nasal endoscopy, offers potential advantages such as the absence of cutaneous scar and preservation of the orbicularis pump function. However, its reported success rates vary widely, ranging from 70% to 95%, depending on surgical expertise and patient selection; factors such as age, sex, diabetes mellitus have been proposed as predictors of failure [\u003cspan additionalcitationids=\"CR5 CR6 CR7 CR8 CR9 CR10\" citationid=\"CR4\" class=\"CitationRef\"\u003e4\u003c/span\u003e\u0026ndash;\u003cspan citationid=\"CR11\" class=\"CitationRef\"\u003e11\u003c/span\u003e].\u003c/p\u003e\u003cp\u003eSeveral comparative studies and meta-analyses have reported similar outcomes between external and endoscopic DCR, although external DCR often maintains slightly higher success rates in long-term follow-up [\u003cspan citationid=\"CR10\" class=\"CitationRef\"\u003e10\u003c/span\u003e, \u003cspan citationid=\"CR12\" class=\"CitationRef\"\u003e12\u003c/span\u003e]. Despite abundant evidence from Europe, Asia, and the Middle East, data from Latin America are scarce. To date, no large comparative cohort of external versus endoscopic DCR has been reported from Mexico.\u003c/p\u003e\u003cp\u003eThe aim of this study was to compare the success rates and complications of external and endoscopic DCR performed at a tertiary referral eye hospital in Mexico, analyzing a large retrospective cohort with standardized follow-up, providing regional data to complement international evidence.\u003c/p\u003e"},{"header":"Methods","content":"\u003cp\u003eStudy design and setting\u003c/p\u003e\u003cp\u003eThis retrospective, longitudinal, comparative cohort study was conducted at Fundaci\u0026oacute;n Hospital Nuestra Se\u0026ntilde;ora de la Luz, a tertiary referral eye hospital in Mexico City. Medical records of patients who underwent external or endoscopic dacryocystorhinostomy (DCR) between January 2019 and December 2024 were reviewed.\u003c/p\u003e\u003cp\u003eParticipants\u003c/p\u003e\u003cp\u003eEligible patients included all individuals diagnosed with acquired nasolacrimal duct obstruction (ANDO) who underwent either external or endoscopic DCR at the Department of Orbit and Oculoplastic during the study period. Inclusion criteria were: age without restriction, diagnosis of ANDO confirmed clinically, surgery performed by the institutional oculoplastic team and minimum postoperative follow-up of six months. Exclusion criteria were: prior lacrimal surgery performed at another institution, incomplete records, concomitant procedures on the same side during surgery and loss to follow-up before six months.\u003c/p\u003e\u003cp\u003eSurgical techniques\u003c/p\u003e\u003cp\u003eExternal DCR was performed through a cutaneous incision with bony ostium creation, lacrimal sac opening, and mucosal flap anastomosis, followed by silicone intubation. Endoscopic DCR was carried out under direct nasal endoscopic visualization with removal of the overlying lacrimal bone, identification and incision of the lacrimal sac and mucosal flap marsupialization, and silicone intubation. Both procedures were performed according to institutional protocols.\u003c/p\u003e\u003cp\u003eData collection\u003c/p\u003e\u003cp\u003eDemographic data (age, sex), clinical variables (laterality, comorbidities), surgical details, postoperative findings, and complications were retrieved from the electronic medical record system. All data were anonymized and handled in compliance with the Declaration of Helsinki and institutional Review Board and Ethics Committee before analysis. The requirement for individual informed consent was waived due to the retrospective nature of the study and anonymization of patient data. Surgical success at six months, was defined as resolution or improvement of epiphora combined with a patent lacrimal irrigation test. Failure was defined as persistent epiphora, absence of irrigation patency, or the need for reoperation. Secondary outcomes included early success (day 1, month 3), perioperative complications, and additional potential risk factors (laterality, comorbidities).\u003c/p\u003e\u003cdiv id=\"Sec3\" class=\"Section2\"\u003e\u003ch2\u003eStatistical analysis\u003c/h2\u003e\u003cp\u003eContinuous variables were summarized as means\u0026thinsp;\u0026plusmn;\u0026thinsp;standard deviation (SD), and categorical variables as frequencies and percentages. Group differences were analyzed using Welch\u0026rsquo;s t-test for continuous data and Fisher\u0026rsquo;s exact test for categorical variables. Statistical significance was set as p\u0026thinsp;\u0026lt;\u0026thinsp;0.05. Analyses were performed using SPSS version 25.0 (IBM Corp., Armonk, NY).\u003c/p\u003e\u003c/div\u003e"},{"header":"Results","content":"\u003cp\u003ePatient characteristics\u003c/p\u003e\u003cp\u003eA total of 255 patients met the inclusion criteria: 24 underwent endoscopic DCR and 226 external DCR. The endoscopic group included significantly younger patients (mean age 40\u0026thinsp;\u0026plusmn;\u0026thinsp;27 years) compared with the external group (57\u0026thinsp;\u0026plusmn;\u0026thinsp;21 years, p\u0026thinsp;=\u0026thinsp;0.005, Welch\u0026rsquo;s t-test) (Table\u0026nbsp;\u003cspan refid=\"Tab1\" class=\"InternalRef\"\u003e1\u003c/span\u003e). Female predominance was observed in both groups (62.5% endoscopic vs 82.3% external). Laterality was evenly distributed (Table\u0026nbsp;\u003cspan refid=\"Tab1\" class=\"InternalRef\"\u003e1\u003c/span\u003e).\u003c/p\u003e\u003cp\u003e\u003cdiv class=\"gridtable\"\u003e\u003ctable float=\"Yes\" id=\"Tab1\" border=\"1\"\u003e\u003ccaption language=\"En\"\u003e\u003cdiv class=\"CaptionNumber\"\u003eTable 1\u003c/div\u003e\u003cdiv class=\"CaptionContent\"\u003e\u003cp\u003eDemographic and clinical characteristics of patients undergoing DCR\u003c/p\u003e\u003c/div\u003e\u003c/caption\u003e\u003ccolgroup cols=\"5\"\u003e\u003cdiv align=\"left\" class=\"colspec\" colname=\"c1\" colnum=\"1\"\u003e\u003c/div\u003e\u003cdiv align=\"left\" class=\"colspec\" colname=\"c2\" colnum=\"2\"\u003e\u003c/div\u003e\u003cdiv align=\"left\" class=\"colspec\" colname=\"c3\" colnum=\"3\"\u003e\u003c/div\u003e\u003cdiv align=\"left\" class=\"colspec\" colname=\"c4\" colnum=\"4\"\u003e\u003c/div\u003e\u003cdiv align=\"left\" class=\"colspec\" colname=\"c5\" colnum=\"5\"\u003e\u003c/div\u003e\u003cthead\u003e\u003ctr\u003e\u003cth align=\"left\" colname=\"c1\"\u003e\u003cp\u003eVariable\u003c/p\u003e\u003c/th\u003e\u003cth align=\"left\" colspan=\"2\" nameend=\"c3\" namest=\"c2\"\u003e\u003cp\u003eEndoscopic DCR (n\u0026thinsp;=\u0026thinsp;24)\u003c/p\u003e\u003c/th\u003e\u003cth align=\"left\" colname=\"c4\"\u003e\u003cp\u003eExternal DCR (n\u0026thinsp;=\u0026thinsp;231)\u003c/p\u003e\u003c/th\u003e\u003cth align=\"left\" colname=\"c5\"\u003e\u003cp\u003ep-value\u003c/p\u003e\u003c/th\u003e\u003c/tr\u003e\u003c/thead\u003e\u003ctbody\u003e\u003ctr\u003e\u003ctd align=\"left\" colspan=\"2\" nameend=\"c2\" namest=\"c1\"\u003e\u003cp\u003eAge, years (mean \u0026plusmn; SD)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e40 (\u0026plusmn;\u0026thinsp;27)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e57 (\u0026plusmn;\u0026thinsp;21)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u003cp\u003e0.005*\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colspan=\"2\" nameend=\"c2\" namest=\"c1\"\u003e\u003cp\u003eSex\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u0026nbsp;\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u0026nbsp;\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u0026nbsp;\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colspan=\"2\" nameend=\"c2\" namest=\"c1\"\u003e\u003cp\u003eFemale\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e15 (62.5%)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e190 (82.3%)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u003cp\u003e0.07\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colspan=\"2\" nameend=\"c2\" namest=\"c1\"\u003e\u003cp\u003eMale\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e9 (37.5%)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e41 (17.7%)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u0026nbsp;\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colspan=\"2\" nameend=\"c2\" namest=\"c1\"\u003e\u003cp\u003eLaterality (right\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u0026nbsp;\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u0026nbsp;\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u003cp\u003e0.91\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colspan=\"2\" nameend=\"c2\" namest=\"c1\"\u003e\u003cp\u003eRight\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e14 (58.3%)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e132 (57.1%)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u0026nbsp;\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colspan=\"2\" nameend=\"c2\" namest=\"c1\"\u003e\u003cp\u003eLeft\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e10 (41.7%)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e99 (42.9%)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u0026nbsp;\u003c/td\u003e\u003c/tr\u003e\u003c/tbody\u003e\u003c/colgroup\u003e\u003c/table\u003e\u003c/div\u003e\u003c/p\u003e\u003cp\u003e*Welch\u0026acute;s t-test. Other comparisons by Fisher-s exact test.\u003c/p\u003e\u003cp\u003eMedia (DE) o Frecuencia (%) Welchs t-test.\u003c/p\u003e\u003cp\u003eSuccess rates\u003c/p\u003e\u003cp\u003eBoth surgical techniques demonstrated high early success rates. On postoperative day 1, success rates were 100% for both external and endoscopic DCR. At 3 months, success remained above 95% in both groups. By 6 months, success was 95.7% for the endoscopic group and 92.2% for the external group. Statistical comparison using Fisher\u0026rsquo;s exact test revealed no significant difference between groups (p\u0026thinsp;\u0026gt;\u0026thinsp;0.05) (Table\u0026nbsp;\u003cspan refid=\"Tab2\" class=\"InternalRef\"\u003e2\u003c/span\u003e). Overall, both techniques demonstrated stable outcomes over time, with no trend toward decline in patency at mid-term follow-up.\u003c/p\u003e\u003cp\u003e\u003cdiv class=\"gridtable\"\u003e\u003ctable float=\"Yes\" id=\"Tab2\" border=\"1\"\u003e\u003ccaption language=\"En\"\u003e\u003cdiv class=\"CaptionNumber\"\u003eTable 2\u003c/div\u003e\u003cdiv class=\"CaptionContent\"\u003e\u003cp\u003eSurgical success rates of DCR at different follow-up points\u003c/p\u003e\u003c/div\u003e\u003c/caption\u003e\u003ccolgroup cols=\"4\"\u003e\u003cdiv align=\"left\" class=\"colspec\" colname=\"c1\" colnum=\"1\"\u003e\u003c/div\u003e\u003cdiv align=\"left\" class=\"colspec\" colname=\"c2\" colnum=\"2\"\u003e\u003c/div\u003e\u003cdiv align=\"left\" class=\"colspec\" colname=\"c3\" colnum=\"3\"\u003e\u003c/div\u003e\u003cdiv align=\"left\" class=\"colspec\" colname=\"c4\" colnum=\"4\"\u003e\u003c/div\u003e\u003cthead\u003e\u003ctr\u003e\u003cth align=\"left\" colname=\"c1\"\u003e\u003cp\u003eFollow-up time\u003c/p\u003e\u003c/th\u003e\u003cth align=\"left\" colname=\"c2\"\u003e\u003cp\u003eEndoscopic DCR n (%)\u003c/p\u003e\u003c/th\u003e\u003cth align=\"left\" colname=\"c3\"\u003e\u003cp\u003eExternal DCR n (%)\u003c/p\u003e\u003c/th\u003e\u003cth align=\"left\" colname=\"c4\"\u003e\u003cp\u003ep-value\u003c/p\u003e\u003c/th\u003e\u003c/tr\u003e\u003c/thead\u003e\u003ctbody\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eDay 1\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e23 (100)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e231 (100)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e-\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003e1 week\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e23 (100)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e230 (99.6)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u0026nbsp;\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003e1 month\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e23 (100)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e223 (96.5)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u0026nbsp;\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003e3 months\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e23 (100)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e221 (95.7)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e-\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003e6 months\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e22 (95.7)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e213 (92.2)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e\u0026gt;\u0026thinsp;0.05*\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003c/tbody\u003e\u003c/colgroup\u003e\u003c/table\u003e\u003c/div\u003e\u003c/p\u003e\u003cp\u003e*Fisher-s exact test.\u003c/p\u003e\u003cp\u003ePostoperative complications\u003c/p\u003e\u003cp\u003eComplications were infrequent and minor, occurring in 1 (4.2%) endoscopic and 5 (2.2%) external cases (Table\u0026nbsp;\u003cspan refid=\"Tab3\" class=\"InternalRef\"\u003e3\u003c/span\u003e). The most frequent event was tube extrusion, in external DCR. No major complications such as orbital cellulitis, hemorrhage, or nasal bleeding were recorded. Most patients (95.8% in the endoscopic and 97.8% in the external group) had an uncomplicated postoperative course.\u003c/p\u003e\u003cp\u003e\u003cdiv class=\"gridtable\"\u003e\u003ctable float=\"Yes\" id=\"Tab3\" border=\"1\"\u003e\u003ccaption language=\"En\"\u003e\u003cdiv class=\"CaptionNumber\"\u003eTable 3\u003c/div\u003e\u003cdiv class=\"CaptionContent\"\u003e\u003cp\u003ePostoperative complications\u003c/p\u003e\u003c/div\u003e\u003c/caption\u003e\u003ccolgroup cols=\"4\"\u003e\u003cdiv align=\"left\" class=\"colspec\" colname=\"c1\" colnum=\"1\"\u003e\u003c/div\u003e\u003cdiv align=\"left\" class=\"colspec\" colname=\"c2\" colnum=\"2\"\u003e\u003c/div\u003e\u003cdiv align=\"left\" class=\"colspec\" colname=\"c3\" colnum=\"3\"\u003e\u003c/div\u003e\u003cdiv align=\"left\" class=\"colspec\" colname=\"c4\" colnum=\"4\"\u003e\u003c/div\u003e\u003cthead\u003e\u003ctr\u003e\u003cth align=\"left\" colname=\"c1\"\u003e\u003cp\u003eComplication type\u003c/p\u003e\u003c/th\u003e\u003cth align=\"left\" colname=\"c2\"\u003e\u003cp\u003eEndoscopic DCR n (%)\u003c/p\u003e\u003c/th\u003e\u003cth align=\"left\" colname=\"c3\"\u003e\u003cp\u003eExternal DCR n (%)\u003c/p\u003e\u003c/th\u003e\u003cth align=\"left\" colname=\"c4\"\u003e\u003cp\u003eTotal n (%)\u003c/p\u003e\u003c/th\u003e\u003c/tr\u003e\u003c/thead\u003e\u003ctbody\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eTube extrusion\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e1 (4.2)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e3 (1.3)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e4 (1.6)\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eWound infection\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e0\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e1 (0.4)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e1 (0.4)\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eInfection with wound dehiscence\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e0\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e1 (0.4)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e1 (0.4)\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eTotal\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e1 (4.2)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e5 (2.2)\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e6 (2.4)\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003c/tbody\u003e\u003c/colgroup\u003e\u003c/table\u003e\u003c/div\u003e\u003c/p\u003e\u003cp\u003eRisk factors for surgical failure\u003c/p\u003e\u003cp\u003eExploratory analysis using Fisher\u0026rsquo;s exact test did not identify any significant predictors of failure. Age group (\u0026lt;\u0026thinsp;50 vs\u0026thinsp;\u0026ge;\u0026thinsp;50 years), sex, laterality, comorbidities, and type of procedure (external vs endoscopic) were not associated with surgical outcome (p\u0026thinsp;\u0026gt;\u0026thinsp;0.05 for all comparisons). The low number of failures limits further multivariate analysis.\u003c/p\u003e"},{"header":"Discussion","content":"\u003cp\u003eBoth external and endoscopic DCR approaches achieved high success rates (\u0026gt;\u0026thinsp;90% at 6 months), with no statistically significant difference. These findings contribute to the global evidence base by providing real-world data from Latin America, a region with limited published series on DCR outcomes.\u003c/p\u003e\u003cp\u003eOur findings align with the established literature reporting external DCR success rates consistently above 90% [\u003cspan citationid=\"CR4\" class=\"CitationRef\"\u003e4\u003c/span\u003e, \u003cspan citationid=\"CR14\" class=\"CitationRef\"\u003e14\u003c/span\u003e]. Endoscopic DCR outcomes in this series (95.7% at six months) fall within the upper range of international reports, where success rates vary between 73% and 95% depending on surgical expertise and adjunctive measures [\u003cspan citationid=\"CR9\" class=\"CitationRef\"\u003e9\u003c/span\u003e, \u003cspan citationid=\"CR11\" class=\"CitationRef\"\u003e11\u003c/span\u003e]. Large comparative series from Turkey [\u003cspan citationid=\"CR5\" class=\"CitationRef\"\u003e5\u003c/span\u003e], India [\u003cspan citationid=\"CR13\" class=\"CitationRef\"\u003e13\u003c/span\u003e], and Europe [\u003cspan citationid=\"CR15\" class=\"CitationRef\"\u003e15\u003c/span\u003e] also reported comparable outcomes, reinforcing the robustness of our results.\u003c/p\u003e\u003cp\u003eSeveral systematic reviews and meta-analyses support these observations. An evidence-based review by the American Academy of Ophthalmology concluded that external DCR may provide slightly higher long-term success, but both approaches are highly effective in experienced hands [\u003cspan citationid=\"CR7\" class=\"CitationRef\"\u003e7\u003c/span\u003e]. A recent Cochrane-style systematic review confirmed no significant difference in outcomes when techniques were standardized [\u003cspan citationid=\"CR17\" class=\"CitationRef\"\u003e17\u003c/span\u003e]. Additional meta-analyses reported similar success when mitomycin C, stenting, or powered instrumentation were applied [\u003cspan additionalcitationids=\"CR19\" citationid=\"CR18\" class=\"CitationRef\"\u003e18\u003c/span\u003e\u0026ndash;\u003cspan citationid=\"CR20\" class=\"CitationRef\"\u003e20\u003c/span\u003e].\u003c/p\u003e\u003cp\u003eStudies from diverse regions align with our results. Rajabi et al. [\u003cspan citationid=\"CR9\" class=\"CitationRef\"\u003e9\u003c/span\u003e] in Iran and Jawad et al. [\u003cspan citationid=\"CR11\" class=\"CitationRef\"\u003e11\u003c/span\u003e] in Pakistan reported no significant differences between external and endoscopic DCR, with success rates above 90% at mid-term follow-up. In Israel, Cohen et al. [\u003cspan citationid=\"CR10\" class=\"CitationRef\"\u003e10\u003c/span\u003e] demonstrated long-term success for endoscopic DCR (86% at 5 years and 80% at 10 years). In Korea, Yun et al. [\u003cspan citationid=\"CR12\" class=\"CitationRef\"\u003e12\u003c/span\u003e] showed that age influenced outcomes, with lower success in elderly patients undergoing endoscopic DCR. Similarly, Tessler et al. [\u003cspan citationid=\"CR21\" class=\"CitationRef\"\u003e21\u003c/span\u003e] found external DCR remained highly effective in geriatric populations, supporting its use as a first-line procedure in older adults.\u003c/p\u003e\u003cp\u003eUnlike prior studies that identified age, male sex, diabetes mellitus, or sinonasal pathology as risk factors for failure [\u003cspan citationid=\"CR5\" class=\"CitationRef\"\u003e5\u003c/span\u003e, \u003cspan citationid=\"CR10\" class=\"CitationRef\"\u003e10\u003c/span\u003e, \u003cspan citationid=\"CR12\" class=\"CitationRef\"\u003e12\u003c/span\u003e, \u003cspan citationid=\"CR13\" class=\"CitationRef\"\u003e13\u003c/span\u003e, \u003cspan additionalcitationids=\"CR22\" citationid=\"CR21\" class=\"CitationRef\"\u003e21\u003c/span\u003e\u0026ndash;\u003cspan citationid=\"CR23\" class=\"CitationRef\"\u003e23\u003c/span\u003e], our series did not detect significant associations. This discrepancy may reflect the limited number of failures observed in our cohort, or differences in population characteristics. Learning curve has also been emphasized as a determinant of outcome in endoscopic DCR, with some authors suggesting that at least 30 procedures are needed to achieve stable success rates [\u003cspan citationid=\"CR15\" class=\"CitationRef\"\u003e15\u003c/span\u003e, \u003cspan citationid=\"CR20\" class=\"CitationRef\"\u003e20\u003c/span\u003e].\u003c/p\u003e\u003cp\u003eComplications in our cohort were rare and minor, consistent with international experience [\u003cspan citationid=\"CR11\" class=\"CitationRef\"\u003e11\u003c/span\u003e, \u003cspan citationid=\"CR13\" class=\"CitationRef\"\u003e13\u003c/span\u003e, \u003cspan citationid=\"CR15\" class=\"CitationRef\"\u003e15\u003c/span\u003e, \u003cspan citationid=\"CR22\" class=\"CitationRef\"\u003e22\u003c/span\u003e]. Tube extrusion was the most frequent, followed by isolated wound infections in external cases. Previous reports describe similar complication profiles, with hemorrhage and sump syndrome being more frequent in endoscopic cases, while scarring and cutaneous issues remain specific to external DCR [\u003cspan citationid=\"CR9\" class=\"CitationRef\"\u003e9\u003c/span\u003e, \u003cspan citationid=\"CR17\" class=\"CitationRef\"\u003e17\u003c/span\u003e, \u003cspan citationid=\"CR25\" class=\"CitationRef\"\u003e25\u003c/span\u003e]. Importantly, no major orbital or systemic complications occurred, underscoring the safety of both techniques in specialized centers.\u003c/p\u003e\u003cp\u003eThis study contributes with one of the first large comparative datasets on DCR from Latin America (255 cases), standardized surgical protocols, and systematic follow-up at six months. To our knowledge, this is the first comparative cohort study of DCR techniques reported from Mexico, contributing valuable data from Latin America. Previous regional reports have been limited to small series or single-technique series. For example, Pablos-Buitr\u0026oacute;n et al [\u003cspan citationid=\"CR24\" class=\"CitationRef\"\u003e24\u003c/span\u003e] in Mexico reported an 83.5% success rate in 172 cases of endoscopic DCR, confirming the reliability of the endonasal approach within the Latin American surgical context. Similarly, Feij\u0026oacute; et al [\u003cspan citationid=\"CR25\" class=\"CitationRef\"\u003e25\u003c/span\u003e] in Brazil described long-term outcomes of diode laser DCR with comparable success and safety, reinforcing that endoscopic approaches remain effective and reproducible across different healthcare systems in the region. Together, these findings demonstrate that surgical results in Latin America are comparable to those from high-volume centers in Europe and Asia [\u003cspan citationid=\"CR5\" class=\"CitationRef\"\u003e5\u003c/span\u003e, \u003cspan citationid=\"CR9\" class=\"CitationRef\"\u003e9\u003c/span\u003e, \u003cspan citationid=\"CR10\" class=\"CitationRef\"\u003e10\u003c/span\u003e, \u003cspan citationid=\"CR13\" class=\"CitationRef\"\u003e13\u003c/span\u003e, \u003cspan citationid=\"CR15\" class=\"CitationRef\"\u003e15\u003c/span\u003e, \u003cspan citationid=\"CR21\" class=\"CitationRef\"\u003e21\u003c/span\u003e, \u003cspan citationid=\"CR25\" class=\"CitationRef\"\u003e25\u003c/span\u003e].\u003c/p\u003e\u003cp\u003eLimitations include its retrospective design, unequal distribution between groups (with external DCR predominating), and lack of standardized patient-reported outcome measures such as quality-of-life questionnaires. Additionally, the six-month follow-up, though clinically meaningful, may underestimate late failures observed in long-term series [\u003cspan citationid=\"CR12\" class=\"CitationRef\"\u003e12\u003c/span\u003e, \u003cspan citationid=\"CR21\" class=\"CitationRef\"\u003e21\u003c/span\u003e, \u003cspan citationid=\"CR23\" class=\"CitationRef\"\u003e23\u003c/span\u003e]. Future prospective, multicenter studies with longer follow-up and patient-reported outcomes are warranted.\u003c/p\u003e"},{"header":"Conclusion","content":"\u003cp\u003eOur findings support that both external and endoscopic DCR remain safe and highly effective options for ANDO. External DCR continues to be reliable, particularly in elderly patients, whereas endoscopic DCR offers cosmetic and sinonasal advantages. Surgical expertise and institutional resources should guide the choice of technique. By contributing one of the first large comparative datasets from Latin America, this study expands the global evidence base and supports the equivalence of both procedures in routine clinical practice.\u003c/p\u003e"},{"header":"Declarations","content":"\u003cp\u003e\u003cstrong\u003eAuthors\u0026rsquo; contributions\u003c/strong\u003e\u003c/p\u003e\n\u003cul\u003e\n \u003cli\u003e[Mart\u0026iacute;nez-Molina CA]: Study conception and design, data collection, data analysis, manuscript drafting.\u003c/li\u003e\n \u003cli\u003e[L\u0026oacute;pez-Garc\u0026iacute;a H]: Data collection, data analysis, critical revision of manuscript.\u003c/li\u003e\n \u003cli\u003e[Dom\u0026iacute;nguez-Hern\u0026aacute;ndez ED]: Statistical analysis, interpretation of results.\u003c/li\u003e\n \u003cli\u003e[Parra F]: Study conception and design, data collection, data analysis, supervision.\u003c/li\u003e\n\u003c/ul\u003e\n\u003cp\u003eAll authors read, commented and approved the final version of the manuscript.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eFunding\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThis research received no specific grant from any funding agency in the public, commercial, or not-for-profit sectors.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eConflicts of interest\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThe authors declare that they have no conflicts of interest related to this work.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eConsent to participate\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThe requirement for informed consent was waived due to the retrospective design of the study and anonymization of patient data, in accordance with institutional and national regulations.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eAvailability of data and materials\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThe datasets generated and/or analyzed during the current study are available from the corresponding author upon reasonable request.\u003c/p\u003e"},{"header":"References","content":"\u003col\u003e\n \u003cli\u003eMakselis A, Petroskas D, Kadziauskiene A et al. Acquired nasolacrimal duct obstruction: clinical and histological findings of 275 cases. BMC Ophthalmol. 2022;22(1):359. doi:10.1186/s12886-022-02590-4\u003c/li\u003e\n \u003cli\u003eYim M, Wormald PJ, Doucet M et al.\u0026nbsp;Adjunctive techniques to dacryocystorhinostomy: an evidence-based review with recommendations. Int Forum Allergy Rhinol. 2021;11(5):885\u0026ndash;93. doi:10.1002/alr.22699\u003c/li\u003e\n \u003cli\u003eUlrich K, Malhotra R, Patel B. Nasolacrimal duct obstruction. In: StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing; 2022.\u003c/li\u003e\n \u003cli\u003eSobel RK, Aakalu VK, Wladis EJ, Bilyk JR, Yen MT, Mawn LA. A comparison of endonasal versus external dacryocystorhinostomy in a tertiary care center. Ophthalmology. 2019;126(10):1360\u0026ndash;6. doi:10.1016/j.ophtha.2019.04.027\u003c/li\u003e\n \u003cli\u003eKarasu B, Kiray G, Eris E, Perente I, Cenk Celebi AR. Comparison of success between external and endonasal dacryocystorhinostomy in primary acquired nasolacrimal duct obstruction in a Turkish cohort. North Clin Istanb. 2020;7(6):579\u0026ndash;84. doi:10.14744/nci.2020.06888\u003c/li\u003e\n \u003cli\u003eVatansever M, Aydin E, Din\u0026ccedil; E, Dursun \u0026Ouml;, \u0026Ouml;zer \u0026Ouml;, Temel G. Endoscopic endonasal dacryocystorhinostomy learning curve. Arq Bras Oftalmol. 2020;85(3):197\u0026ndash;201. doi:10.5935/0004-2749.20200031\u003c/li\u003e\n \u003cli\u003eVinciguerra A, Resti AG, Rampi A, Bussi M, Bandello F, Trimarchi M. Endoscopic and external dacryocystorhinostomy: a therapeutic proposal for distal acquired lacrimal obstructions. Eur J Ophthalmol. 2023;33(3):1287\u0026ndash;93. doi:10.1177/11206721221132746\u003c/li\u003e\n \u003cli\u003eHerzallah IR, Marglani OA, Alherabi AZ, Faraj NS, Bukhari DH. Bilateral simultaneous endoscopic dacryocystorhinostomy: outcome and impact on the quality of life of the patients. Int Arch Otorhinolaryngol. 2019;23(2):191\u0026ndash;5. doi:10.1055/s-0038-1675394\u003c/li\u003e\n \u003cli\u003eRajabi MT, Shahraki K, Nozare A et al. External versus endoscopic dacryocystorhinostomy for primary acquired nasolacrimal duct obstruction. Middle East Afr J Ophthalmol. 2022;29(1):1\u0026ndash;6. doi:10.4103/meajo.meajo_238_21\u003c/li\u003e\n \u003cli\u003eCohen O, Amos I, Halperin D et al. Five- and 10-year outcomes for primary endoscopic dacryocystorhinostomy: failure rate and risk factors. Laryngoscope. 2020;130(9):E548\u0026ndash;54. doi:10.1002/lary.28532\u003c/li\u003e\n \u003cli\u003eJawad A, Kausar A, Iftikhar S, Akhtar N, Rabbani Z. Results of endoscopic endonasal dacryocystorhinostomy: a prospective cohort study. J Pak Med Assoc. 2021;71(5):1420\u0026ndash;3. doi:10.47391/JPMA.187\u003c/li\u003e\n \u003cli\u003eYun SJ, Lee YH, Kim KN, Kang TS, Lee SB. Surgical outcomes of endoscopic dacryocystorhinostomy: analysis of age effect. Sci Rep. 2019;9:19861. doi:10.1038/s41598-019-56329-2\u003c/li\u003e\n \u003cli\u003eBothra N, Ali MJ, Naik MN. Functional outcomes after dacryocystorhinostomy: a large cohort from India. Orbit. 2019;38(2):133\u0026ndash;9. doi:10.1080/01676830.2018.1479748\u003c/li\u003e\n \u003cli\u003eAli MJ. Dacryocystorhinostomy: from evolution to revolution. Saudi J Ophthalmol. 2021;35(3):213\u0026ndash;9. doi:10.4103/1319-4534.327993\u003c/li\u003e\n \u003cli\u003eLeong SC, MacEwen CJ, White PS. A systematic review of outcomes after dacryocystorhinostomy in Europe. Clin Otolaryngol. 2020;45(5):605\u0026ndash;12. doi:10.1111/coa.13550\u003c/li\u003e\n \u003cli\u003eSmith J, Hussain R, Mahroo O et al. Endoscopic versus external dacryocystorhinostomy: Cochrane-style systematic review. Int Forum Allergy Rhinol. 2021;11(9):1432\u0026ndash;40. doi:10.1002/alr.22781\u003c/li\u003e\n \u003cli\u003eBaldeschi L, Hintschich CR. Adjunctive measures in endoscopic dacryocystorhinostomy: systematic review and consensus. Orbit. 2022;41(2):113\u0026ndash;21. doi:10.1080/01676830.2021.1964642\u003c/li\u003e\n \u003cli\u003eLiang J, Hur K, Stokken J, et al. Endoscopic versus external dacryocystorhinostomy: a meta-analysis of randomized controlled trials. Otolaryngol Head Neck Surg. 2020;162(2):229\u0026ndash;36. doi:10.1177/0194599819875852\u003c/li\u003e\n \u003cli\u003eHeichel J, Struck HG. Adjunctive mitomycin C in endoscopic dacryocystorhinostomy: a systematic review. Graefes Arch Clin Exp Ophthalmol. 2019;257(8):1615\u0026ndash;22. doi:10.1007/s00417-019-04368-0\u003c/li\u003e\n \u003cli\u003eTessler I, Warman M, Amos I et al. Endoscopic dacryocystorhinostomy among the old and oldest-old populations: a case-control study. Auris Nasus Larynx. 2021;48(2):273\u0026ndash;8. doi:10.1016/j.anl.2020.09.004\u003c/li\u003e\n \u003cli\u003eKeren S, Abergel A, Manor A et al. Endoscopic dacryocystorhinostomy: reasons for failure. Eye (Lond). 2020;34(5):948\u0026ndash;53. doi:10.1038/s41433-019-0600-3\u003c/li\u003e\n \u003cli\u003eMandal P, Ahluwalia H. Do topical ocular antihypertensives affect dacryocystorhinostomy outcomes? Eye (Lond). 2022;36(1):135\u0026ndash;9. doi:10.1038/s41433-021-01463-3\u003c/li\u003e\n \u003cli\u003eWormald PJ, Tsirbas A. Powered endoscopic dacryocystorhinostomy. Laryngoscope. 2020;130 Suppl 7:S1\u0026ndash;10. doi:10.1002/lary.28389\u003c/li\u003e\n \u003cli\u003ePablos-Buitr\u0026oacute;n E, Mart\u0026iacute;nez-Mor\u0026aacute;n A, Lage-Fern\u0026aacute;ndez J, Cerdeira-Pena P, P\u0026eacute;rez-Varela V. Endoscopic dacryocystorhinostomy. Results in 172 patients. Rev Mex Oftalmol. 2021;95(4):137\u0026ndash;141. doi:10.24875/RMOE.M21000173\u003c/li\u003e\n \u003cli\u003eFeij\u0026oacute; ED, Fernandes RM, Silva J\u0026uacute;nior A, Neves MC, Pinto JM. Long-term outcomes of modified transcanalicular diode laser dacryocystorhinostomy in a large cohort. \u0026nbsp;Arq Bras Oftalmol. 2024;87(5):e0024. Doi:105935/0004-2749.20240024\u003c/li\u003e\n\u003c/ol\u003e"}],"fulltextSource":"","fullText":"","funders":[],"hasAdminPriorityOnWorkflow":false,"hasManuscriptDocX":true,"hasOptedInToPreprint":true,"hasPassedJournalQc":"","hasAnyPriority":false,"hideJournal":false,"highlight":"","institution":"","isAcceptedByJournal":false,"isAuthorSuppliedPdf":false,"isDeskRejected":"","isHiddenFromSearch":false,"isInQc":false,"isInWorkflow":false,"isPdf":false,"isPdfUpToDate":true,"isWithdrawnOrRetracted":false,"journal":{"display":true,"email":"[email protected]","identity":"international-ophthalmology","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":false,"externalIdentity":"inte","sideBox":"Learn more about [International Ophthalmology](https://www.springer.com/journal/10792)","snPcode":"10792","submissionUrl":"https://submission.nature.com/new-submission/10792/3","title":"International Ophthalmology","twitterHandle":"","acdcEnabled":true,"dfaEnabled":true,"editorialSystem":"em","reportingPortfolio":"Springer Hybrid","inReviewEnabled":true,"inReviewRevisionsEnabled":false},"keywords":"dacryocystorhinostomy, nasolacrimal duct obstruction, endoscopic DCR, external DCR, lacrimal surgery","lastPublishedDoi":"10.21203/rs.3.rs-7782679/v1","lastPublishedDoiUrl":"https://doi.org/10.21203/rs.3.rs-7782679/v1","license":{"name":"CC BY 4.0","url":"https://creativecommons.org/licenses/by/4.0/"},"manuscriptAbstract":"\u003cp\u003ePurpose:\u0026nbsp;\u003c/p\u003e\n\u003cp\u003eTo compare surgical outcomes and complications of external versus endoscopic dacryocystorhinostomy (DCR) in patients with acquired nasolacrimal duct obstruction (ANDO) treated at a tertiary referral eye hospital in Mexico.\u003c/p\u003e\n\u003cp\u003eMethods\u003c/p\u003e\n\u003cp\u003eWe conducted a retrospective, single-center, comparative study of patients undergoing external or endoscopic DCR treated between January 2019 and December 2024. Surgical success was defined as resolution or improvement of epiphora with a patent lacrimal irrigation at 6-month follow-up. Demographic variables, comorbidities, surgical technique, and complications were recorded and analyzed using Welch’s t-test and Fisher’s exact test.\u003c/p\u003e\n\u003cp\u003eResults\u003c/p\u003e\n\u003cp\u003eA total of 255 patients were included (mean age: 40 years in the endoscopic group, 57 years in the external group; p = 0.005). Female predominance was observed in both groups. Success rates were 100% for both techniques on day 1, and remained above 95% at 3 months. At 6 months, success was 95.7% for endoscopic DCR and 92.2% for external DCR; no statistically significant difference was found (p \u0026gt; 0.05). Complication rates were low in both groups (4.2% in endoscopic vs. 2.2% in external), mainly tube extrusion and local infection. No risk factors for failure were identified.\u003c/p\u003e\n\u003cp\u003eConclusions\u003c/p\u003e\n\u003cp\u003eBoth external and endoscopic DCR achieved high and comparable success rates with few complications in this large single-center cohort. These findings support the use of both techniques and provide valuable data from Latin America to complement global evidence on the surgical management of ANDO.\u003c/p\u003e","manuscriptTitle":"External versus endoscopic dacryocystorhinostomy for acquired nasolacrimal duct obstruction: outcomes from a Mexican tertiary eye hospital","msid":"","msnumber":"","nonDraftVersions":[{"code":1,"date":"2025-11-24 13:18:38","doi":"10.21203/rs.3.rs-7782679/v1","editorialEvents":[{"type":"communityComments","content":0},{"type":"editorInvitedReview","content":"","date":"2025-11-24T01:45:30+00:00","index":"hide","fulltext":""},{"type":"reviewerAgreed","content":"307254465144377840832045073494723447601","date":"2025-11-13T05:00:33+00:00","index":"hide","fulltext":""},{"type":"reviewersInvited","content":"","date":"2025-11-12T12:59:44+00:00","index":"","fulltext":""},{"type":"editorAssigned","content":"","date":"2025-10-06T05:29:15+00:00","index":"","fulltext":""},{"type":"checksComplete","content":"","date":"2025-10-06T05:27:19+00:00","index":"","fulltext":""},{"type":"submitted","content":"International Ophthalmology","date":"2025-10-05T04:10:46+00:00","index":"","fulltext":""}],"status":"published","journal":{"display":true,"email":"[email protected]","identity":"international-ophthalmology","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":false,"externalIdentity":"inte","sideBox":"Learn more about [International Ophthalmology](https://www.springer.com/journal/10792)","snPcode":"10792","submissionUrl":"https://submission.nature.com/new-submission/10792/3","title":"International Ophthalmology","twitterHandle":"","acdcEnabled":true,"dfaEnabled":true,"editorialSystem":"em","reportingPortfolio":"Springer Hybrid","inReviewEnabled":true,"inReviewRevisionsEnabled":false}}],"origin":"","ownerIdentity":"1539b0d3-d562-4137-a92a-8c7238b69e3f","owner":[],"postedDate":"November 24th, 2025","published":true,"recentEditorialEvents":[],"rejectedJournal":[],"revision":"","amendment":"","status":"under-review","subjectAreas":[],"tags":[],"updatedAt":"2025-11-24T13:18:38+00:00","versionOfRecord":[],"versionCreatedAt":"2025-11-24 13:18:38","video":"","vorDoi":"","vorDoiUrl":"","workflowStages":[]},"version":"v1","identity":"rs-7782679","journalConfig":"researchsquare"},"__N_SSP":true},"page":"/article/[identity]/[[...version]]","query":{"redirect":"/article/rs-7782679","identity":"rs-7782679","version":["v1"]},"buildId":"8U1c8b4HqxoKbykW_rLl7","isFallback":false,"isExperimentalCompile":false,"dynamicIds":[84888],"gssp":true,"scriptLoader":[]}