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Nasolacrimal Stents in the Treatment of Epiphora
Nasolacrimal Stents in the Treatment of Epiphora: Long-term Results Laura Paúl, MD, Isabel Pinto, MD, Jose Manuel Vicente, MD, Ana Armendariz, RT, Gema Moreno, RT, and M. Cruz Baraibar, RN
PURPOSE: Assessment of the long-term results achieved with use of nasolacrimal stents in the treatment of epiphora caused by obstruction of the lacrimal apparatus. The role of stents in treating this condition is evaluated. MATERIALS AND METHODS: From February 1997 to April 1999, a total of 89 procedures to insert nasolacrimal stents were performed in 77 patients (20 men, 57 women; mean age, 53 years). A total of 79 stents were successfully implanted, with 10 failures (11.2%). Postprocedural course was followed for 16 –38 months (mean, 27 mo) by means of clinical examinations and/or periodic dacryocystography, with removal of occluded stents. On conclusion of the study in September 2000, dacryocystography was performed in all patients in whom stents were still in place. RESULTS: Of the 79 stents deployed, two were lost, two had to be excluded from the study, 45 (60%) ceased to function, and 30 (40%) remained patent. Median duration of stent patency of these 79 stents was 20 months. Mean time to occlusion was 9.2 months for all obstructed stents; 4.4 months for improperly placed stents (via a trajectory outside the normal lacrimal drainage apparatus) and 12.2 months for stents that appeared to have been inserted properly. Of the 45 occluded stents, 40 were removed and five were left in place. Upon removal, adherence of the stents to the lacrimal apparatus was frequently observed. CONCLUSIONS: The low patency rate and the difficulties encountered in removing nasolacrimal stents during the course of long-term placement calls into question the efficacy of this method as a definitive treatment for epiphora caused by obstruction of the lacrimal drainage system, although studies comparing this and other treatment modalities are needed. Assessment of temporary stent placement may be in order. Index terms:
Lacrimal gland and duct
•
Nasolacrimal obstruction
•
Stents and prostheses
J Vasc Interv Radiol 2002; 13:83– 88
EPIPHORA secondary to obstruction of the lacrimal drainage system is a common ophthalmological problem. Treatment involves surgical and interventional radiologic procedures. There has been considerable development in these latter procedures in recent years because they afford the advantages of being better tolerated by patients, they do not require general anesthesia, and avoidance of facial scarring. The two procedures avail-
From the Radiology Service, Section of Vascular and Interventional Radiology, Hospital Universitario de Getafe, Carretera de Toledo Km 12,5. 28905, Getafe, Madrid, Spain. Received May 29, 2001; revision requested July 12; revision received September 11; accepted September 12. Address correspondence to L.P.; E-mail: [email protected] © SCVIR, 2002
able, (i) balloon dilation of the lacrimal apparatus, or dacryocystoplasty, and (ii) placement of nasolacrimal stents, both seek to achieve results comparable to those obtained with use of dacryocystorhinostomy (1,2). Dacryocystoplasty attains initial success rates of 40%–90% in resolving epiphora, with short-term (2– 6 months) improvement rates of 20%– 75%, depending on the series; however, according to most reports, recurrence rates are 50% at less than 1 year, with even worse results in cases in which there is complete blockage of the lacrimal system than in cases of stricture (3– 6). Placement of a stent within the lacrimal apparatus relieves the epiphora in 70%–100% of patients, with a recurrence rate of approximately 30% after
1 year. In particular, the results achieved in cases of obstruction are better than the results obtained with use of dacryocystoplasty (7–10). Nevertheless, although the results achieved using this procedure are acceptable over the medium term, published reports of the progressive blockage of nasolacrimal stents by detritus or inflammatory tissue (11) call into question both the efficacy and applicability of this procedure. We describe our long-term experience with the use of nasolacrimal stents in a series of 89 procedures with a mean follow-up time in excess of 2 years, thereby adding to the scant information available in this respect and helping to properly assess the true scope of this procedure in the treatment of epiphora caused by obstruction of the lacrimal system.
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MATERIALS AND METHODS Study Population Between February 1997 and April 1999, a total of 89 polyurethane stent placement procedures were performed in 77 consecutive patients with epiphora caused by obstruction of the lacrimal system. The patient population was 20 males and 57 females, with a mean age of 53 years. The first 70 procedures have been included in a previous study (10). Epiphora was graded subjectively according to the Munk scale (12). Diagnosis of lacrimal obstruction was made by dacryocystography. Patients with grade III or grade IV epiphora and blockage of the lacrimal apparatus at the level of the lacrimal sac or duct were candidates for inclusion in the study, without regard to the length of the obstruction, the amount of time patients had the condition, or patient age. Exclusion criteria were obstruction of the common canaliculus or an atrophied lacrimal sac too small to house a stent. Patients with acute dacryocystitis received antibiotic therapy until symptoms had subsided before undergoing intervention; even so, in some cases pus was found to be present in the lacrimal sac during the procedure, although this was not regarded as a contraindication for performance of the procedure. Stent Placement Technique The procedure was performed on an ambulatory patient basis under sedation and local anesthesia. The sedative used was intravenous midazolam, and the local anesthesia consisted of infiltration with 2% lidocaine (supratrochlear nerve, infraorbital nerve, and nostril) and nasal packing impregnated with a solution of 10% tetracaine hydrochloride and epinephrine. The Song nasolacrimal duct stent set (Cook Ireland, Limerick, Ireland) was used in all cases, the set being composed of a rigid 0.018-inch ball guide wire with balls at each end, a 6-F dilator, and a polyurethane stent and pusher. The stent placement technique was basically as that described by Song et al (7,13) with certain modifications as described by Pinto et al (10). Dacryocystography was performed at the conclusion of every procedure to
verify proper stent placement and patency. The 89 procedures completed resulted in placement of 79 stents, with failure to correctly intubate the lacrimal drainage system in 10 cases. In the first 50 procedures, computed tomography (CT) was also performed systematically to assess the position of the stent in the lacrimal system, but in the remaining procedures CT was performed only in those cases in which improper placement of the stent was suspected. Maxitrol (Alcon Iberhis, Madrid, Spain) and Rhinocort (Astra España, Barcelona, Spain) were administered for 10 days after the procedure. Follow-up The postprocedural course of the 79 stents inserted was followed to the termination of the study in September 2000 (follow-up, 16 –38 mo; mean, 27 mo). Periodic clinical examinations were carried out after 10 days and at 1 month and 3 months, and thereafter every 6 months after the procedure, with dacryocystography yearly or on recurrence of epiphora. When occlusion occurred, stents were washed with saline solution in an effort to clear them before removal. Blocked stents that could not be cleared by lavage were removed after dacryocystography. During the first 2 years of the study, removal was performed by a otorhinolaryngologist and, during the final year, by the authors themselves under radiologic guidance, with patient preparation and subsequent topical treatment the same as that used for stent insertion (local anesthesia and/or sedation, plus Maxitrol and Rhinocort). Dacryocystography was also performed at the termination of each stent removal procedure. Statistical Analysis Stent survival time was estimated by means of Kaplan-Meier curves. Survival time has been reported as median survival time and by interquartile range.
RESULTS Implantation of the nasolacrimal stent failed in 10 of the 89 procedures
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undertaken (11.2%), with a final result of 79 stents placed in 67 patients (bilateral stents were inserted in four patients and two stents were inserted successively in eight patients). The cause of the obstruction was lesions in the lacrimal apparatus in all cases but one, in which there was stenosis. The location of placement was seven in the lacrimal sac, seven in the nasolacrimal duct, and the remainder at the junction between the sac and the duct. Follow-up ranged from 16 to 38 months, with a mean of 27 months. Two patients were lost to follow-up, and an additional two cases had to be excluded from the study: in one case, the stent was removed while still patent 2 months after placement because the patient developed repeated episodes of conjunctivitis with nonsterile tears; in the other case, the patient died while the stent was still in place and patent at 2 years after insertion. Of the remaining 75 cases, at the end of the study, a total of 45 stents (60%) had become occluded and 30 (40%) remained patent. Median duration of stent patency was 20 months, with interquartiles of 7 months (75% stent patency rate) and 36 months (25% stent patency rate; Fig 1). A total of 45 stents became blocked. Of these, 29 stents had been properly placed and 16 had been improperly placed, or malpositioning was regarded as likely (in most cases dorsally to the lacrimal sac according to CT and/or dacryocystography examination results) (10). All of the improperly placed stents became occluded in less than 1 year, with a mean time to occlusion of 4.4 months. For the 29 stents that had been properly positioned within the lacrimal system, the mean time to occlusion was 12.2 months. In all, 40 of the 45 occluded stents were removed. Five stents were not removed, three because the patients refused and two because adherence to the lacrimal tract made removal unfeasible. These five cases all belonged to the group of 29 stents that appeared to have been properly placed, with the longer mean time to occlusion. In all the cases in this group, dacryocystography performed before removal demonstrated a reduction in the size of the lacrimal sac as compared to the results obtained on dacryocystography per-
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Figure 1. Stent patency: median duration of stent patency was 20 months (interquartile range ⫽ 7; 36). ⬜ ⫽ SE.
formed in these same patients before stent placement (Fig 2). In eight patients in our study, a second stent was inserted after occlusion of the first. Ten of the stents that did not become blocked required lavage during follow-up to maintain patency. Clinically, 26 of these 30 cases were free from epiphora, three exhibited occasional epiphora, and one had grade IV epiphora. Overall, clinical symptoms failed to correlate with the radiologic findings during follow-up in six cases in our study. In four cases in which dacryocystography showed the stents to be occluded, the patients reported no symptoms of epiphora (these cases were all counted as occluded stents, and removal of the stents was recommended to the patients); conversely, in two patients who had grade IV epiphora, the dacryocystography findings showed the stents to be fully patent.
DISCUSSION The primary object of this study was to assess the usefulness of polyurethane nasolacrimal stents in the long-term treatment of epiphora caused by blockage of the lacrimal drainage system. The technical aspects of stent placement and short-term re-
sults have already been published and discussed in previous articles using material essentially similar to the data compiled over the longer period of follow-up reported here (10). During a mean follow-up period of 2 years and a minimum follow-up duration of 16 months, we achieved a 40% patency rate in a total of 75 stents, nearly all inserted to treat complete obstruction of the lacrimal sac or duct. No attempt was made to carry out periodic lavage to avert blockage of the stents. Comparing our results with the literature results failed to yield equally long follow-up periods but did disclose occlusion rates of 25% at 7 months (11), 31% at 1 year (8), and 37% at 1 year (10). Better results have been achieved by routinely carrying out lavage of inserted stents. For instance, Lee et al (14) reported an occlusion rate of only 8% after a mean follow-up of 22 months for stents inserted without the use of radiologic guidance but with lavage at 1, 3, 6, and thereafter every 6 months after placement; and Lanciego et al (15) achieved an occlusion rate of 15% for 183 stents after follow-up periods of 8 –730 days. No series has had a follow-up as consistently as long as ours, but on extrapolation the results attained by other workers would seem to be better than
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our results overall. Two factors may have come into play in this respect: close ophthalmologic follow-up with periodic lavage of stents and low malpositioning rates. A certain portion of stents appeared to be improperly positioned or to traverse a false trajectory outside the normal lacrimal system. In our study, these stents have been counted as a separate category. False trajectories of this kind are created by the guide wire when trying to negotiate the lacrimal apparatus, which is ordinarily torn before the lacrimal sac is reached (13). This results in the positioning of stents dorsally and/or medially to the lacrimal sac, and such stents tend to be particularly vulnerable to early occlusion (10,11). Nevertheless, it is hard to identify this problem with any degree of certainty, even when CT and dacryocystography are used, and in most reported series such cases have not been separated from the category of occluded stents as a whole. In our series, 19% of all the stents inserted were malpositioned, and the improperly placed stents had a mean time to occlusion of 4.4 months. Certain technical procedures, such as the use of flexible guide wires (11) and selection of patients to exclude those who have alterations of the canaliculi (15), help reduce the rate of improper stent placement. Even after excluding those stents that had been improperly positioned and, as a result, displayed a tendency to become blocked early, based on the overall experience gained in stent placement in other anatomic structures, all nasolacrimal stents can be expected to become occluded over time. In our series, the mean time to occlusion was 12.2 months for the properly positioned stents only and 9.2 months for all stents combined, with no distinctions made based on proper or improper positioning. The cause of occlusion may be blockage of the stent itself ascribable to clots, detritus, or mucus, or blockage may be ascribable to the gradual spread of inflammatory stenotic lesions in the canaliculi in the lacrimal system above the stent or to the growth of granulation tissue in the lacrimal sac in reaction to the presence of the stent. This last-mentioned cause of occlusion becomes more frequent over time (8,11) and gives the greatest cause for concern, on the one hand because it
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Figure 2. Instance of the reduction in size of the lacrimal sac. (a) Dacryocystogram in a patient with grade IV epiphora. This figure shows obstruction at the junction of the sac and the nasolacrimal duct, an irregularly shaped lacrimal sac, and duplication and stenosis of the common canaliculus. (b) Placement of a nasolacrimal stent, resolving the epiphora; dacryocystography performed immediately after insertion showed the stent to be patent. (c) Control dacryocystogram performed 2 months after the procedure because of occasional recurrence of epiphora in this patient, showing the stent to be patent. The stent was washed on three separate occasions for that same reason, with symptoms improving after washing. (d) Dacryocystogram obtained at 1 year after stent placement, showing recurring, increasingly more frequent grade III–IV epiphora. Occlusion did not respond to lavage, and the stent was removed. (e) Dacryocystogram obtained after stent removal showing an appreciable reduction in the size of the lacrimal sac as compared to the size recorded on examination before stent placement.
reduces the size of the lacrimal sac and therefore makes the performance of future dacryocystorhinostomy more difficult, and on the other because, as we have seen in our series, it may lead to adherence of the stent to the lacrimal tract, making removal impossible (Fig 3). We have not kept an exact
record of the number of cases in which this problem arose, but the situation was commonly encountered in cases in which removal of stents that had been in place for more than a year was attempted and, indeed, two cases required us to leave occluded stents in place. The literature has drawn atten-
tion to the formation of granulation tissue around inserted stents (11), but there have been no reports implicating this as a source of difficulty affecting stent removal, perhaps because of shorter follow-up periods. Conversely, the lacrimal drainage system has been reported not to remain patent after re-
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Figure 3. Difficulty in stent removal. (a) Placement of a nasolacrimal stent in the left lacrimal system in a 64-year-old patient who had grade IV epiphora caused by obstruction of the lacrimal drainage system at the junction of the lacrimal sac and the nasolacrimal duct. (b) Occlusion of the stent 3 years after placement. (c) Elongation of the stent and difficulty in removal because the stent had adhered to the lacrimal sac. The stent was eventually removed.
moval of occluded stents (patency rates of 15%–30% in the medium term) (8,11), although, again, there are also apparent discrepancies in the results achieved, with reported patency rates of 89% at 15–540 days after the removal of occluded stents (15). Therefore, certain literature reports to the contrary notwithstanding, follow-up in our series appears to demonstrate that the gradual blockage of nasolacrimal stents is inescapable. In the circumstances, dacryocystoplasty is another interventional therapeutic option. However, the rate of immediate resolution of the epiphora of 40%– 80% is lower than that attained with use of stents, and the rate of recurrence at 1 year is higher than 50% in cases of complete obstruction of the lacrimal apparatus (3– 6). Better results have been achieved in cases of stenotic lesions. For instance, Jansen (16) obtained long-term (20 mo) lacrimal tract patency rates of 70%– 80% in a series with an overall stenosis rate of 73%. Based on literature reports published to date, the efficacy of dacryocystoplasty would not appear to be comparable to that of nasolacrimal stents in cases of complete obstruction of the lacrimal system.
Finally, surgery appears to be more effective, with cure rates of 90% for surgical dacryocystorhinostomy and 70% for endonasal laser dacryocystorhinostomy at 1 year (1,2), although there have been no reports of follow-up periods longer than 1 year. In conclusion, treatment of idiopathic obstruction of the lacrimal system and obstruction secondary to recurrent episodes of inflammation is a difficult issue. The long-term results achieved using polyurethane nasolacrimal stents have not been encouraging. To improve stent efficacy work on several different aspects of nasolacrimal stents would appear to be called for (periodic lavage, prevention or curbing of infection of the lacrimal system, combined treatment with dacryocystoplasty and a stent, use of stents for temporary dilatation followed by removal before blockage due to tissue growth, and so forth). Nevertheless, for the time being, until comparative trials contrasting final results in the treatment of idiopathic obstruction of the lacrimal system achieved with use of dacryocystorhinostomy and interventional radiologic methods become available, the use of stents should not be recommended as a final treatment.
References 1. Rosen N, Shamir M, Moverman DC, Rosner M. Dacryocystorhinostomy with silicone tubes: evaluation of 253 cases. Ophthalmol Surg 1989; 20:115– 119. 2. Hartikainen J, Grenman R, Puukka P, Seppa H. Prospective randomized comparison of external dacryocystorhinostomy and endonasal laser dacryocystorhinostomy. Ophthalmology 1998; 105: 1106 –1113. 3. Song HY, Ahn HS, Park CK, Kwon SH, Kim CS, Choi KC. Complete obstruction of the nasolacrimal system: treatment with balloon dilatation. Radiology 1993; 186:367–371. 4. Lee JM, Song HY, Han YM, et al. Balloon dacryocystoplasty: results in the treatment of complete and partial obstructions of the nasolacrimal system. Radiology 1994; 192:503–508. 5. Liermann D, Berkefeld J, Fries U, Schalnus RW, Gümpel H. Balloon dacryocystoplasty: an alternative treatment for obstructed tear ducts. Ophthalmologica 1996; 210:319 –324. 6. Berkefeld J, Kirchner J, Müller HM, Fries U, Kollath J. Balloon dacryocystoplasty: indications and contraindications. Radiology 1997; 205:785–790. 7. Song HY, Jin YH, Kim JH, Sung KB, Han YM, Cho NC. Nasolacrimal duct obstruction treated nonsurgically with
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use of plastic stents. Radiology 1994; 190:535–539. 8. Song HY, Jin YH, Kim JH, et al. Nonsurgical placement of a nasolacrimal polyurethane stent: long-term effectiveness. Radiology 1996; 200:759 –763. 9. Pulido-Duque JM, Reyes R, Carreira JM, et al. Treatment of complete and partial obstruction of the nasolacrimal system with polyurethane stents: initial experience. Cardiovasc Invervent Radiol 1998; 21:450 – 453. 10. Pinto I, Paul L, Grande C, de la Cal MA. Nasolacrimal polyurethane stent placement for epiphora: technical
long-term results. J Vasc Interv Radiol 2001; 12:67–71. 11. Song HY, Lee DH, Ahn H, et al. Lacrimal system obstruction treated with lacrimal polyurethane stents: outcome of removal of occluded stents. Radiology 1998; 208:689 – 694. 12. Munk PL, Lin DTC, Morris DC. Epiphora: treatment by means of dacryocystoplasty with balloon dilatation of the nasolacrimal drainage apparatus. Radiology 1990; 177:687– 690. 13. Song HY, Jin YH, Kim JH, et al. Nonsurgical placement of a nasolacrimal polyurethane stent. Radiology 1995; 194:233–237.
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14. Lee JS, Jung G, Oum BS, Lee SH, Roh HJ. Clinical efficacy of the polyurethane stent without fluoroscopic guidance in the treatment of nasolacrimal duct obstruction. Ophthalmology 2000; 107:1666 –1670. 15. Lanciego C, De Miguel S, Perea M, et al. Nasolacrimal stents in the management of epiphora: medium-term results of a multicenter prospective study. J Vasc Interv Radiol 2001; 12:701–710. 16. Janssen AG, Mansour K, Bos JJ. Obstructed nasolacrimal duct system in epiphora: long-term results of dacryocystoplasty by means of balloon dilatation. Radiology 1997; 205:791–796.
PURPOSE: Assessment of the long-term results achieved with use of nasolacrimal stents in the treatment of epiphora caused by obstruction of the lacrimal apparatus. The role of stents in treating this condition is evaluated. MATERIALS AND METHODS: From February 1997 to April 1999, a total of 89 procedures to insert nasolacrimal stents were performed in 77 patients (20 men, 57 women; mean age, 53 years). A total of 79 stents were successfully implanted, with 10 failures (11.2%). Postprocedural course was followed for 16 –38 months (mean, 27 mo) by means of clinical examinations and/or periodic dacryocystography, with removal of occluded stents. On conclusion of the study in September 2000, dacryocystography was performed in all patients in whom stents were still in place. RESULTS: Of the 79 stents deployed, two were lost, two had to be excluded from the study, 45 (60%) ceased to function, and 30 (40%) remained patent. Median duration of stent patency of these 79 stents was 20 months. Mean time to occlusion was 9.2 months for all obstructed stents; 4.4 months for improperly placed stents (via a trajectory outside the normal lacrimal drainage apparatus) and 12.2 months for stents that appeared to have been inserted properly. Of the 45 occluded stents, 40 were removed and five were left in place. Upon removal, adherence of the stents to the lacrimal apparatus was frequently observed. CONCLUSIONS: The low patency rate and the difficulties encountered in removing nasolacrimal stents during the course of long-term placement calls into question the efficacy of this method as a definitive treatment for epiphora caused by obstruction of the lacrimal drainage system, although studies comparing this and other treatment modalities are needed. Assessment of temporary stent placement may be in order. Index terms:
Lacrimal gland and duct
•
Nasolacrimal obstruction
•
Stents and prostheses
J Vasc Interv Radiol 2002; 13:83– 88
EPIPHORA secondary to obstruction of the lacrimal drainage system is a common ophthalmological problem. Treatment involves surgical and interventional radiologic procedures. There has been considerable development in these latter procedures in recent years because they afford the advantages of being better tolerated by patients, they do not require general anesthesia, and avoidance of facial scarring. The two procedures avail-
From the Radiology Service, Section of Vascular and Interventional Radiology, Hospital Universitario de Getafe, Carretera de Toledo Km 12,5. 28905, Getafe, Madrid, Spain. Received May 29, 2001; revision requested July 12; revision received September 11; accepted September 12. Address correspondence to L.P.; E-mail: [email protected] © SCVIR, 2002
able, (i) balloon dilation of the lacrimal apparatus, or dacryocystoplasty, and (ii) placement of nasolacrimal stents, both seek to achieve results comparable to those obtained with use of dacryocystorhinostomy (1,2). Dacryocystoplasty attains initial success rates of 40%–90% in resolving epiphora, with short-term (2– 6 months) improvement rates of 20%– 75%, depending on the series; however, according to most reports, recurrence rates are 50% at less than 1 year, with even worse results in cases in which there is complete blockage of the lacrimal system than in cases of stricture (3– 6). Placement of a stent within the lacrimal apparatus relieves the epiphora in 70%–100% of patients, with a recurrence rate of approximately 30% after
1 year. In particular, the results achieved in cases of obstruction are better than the results obtained with use of dacryocystoplasty (7–10). Nevertheless, although the results achieved using this procedure are acceptable over the medium term, published reports of the progressive blockage of nasolacrimal stents by detritus or inflammatory tissue (11) call into question both the efficacy and applicability of this procedure. We describe our long-term experience with the use of nasolacrimal stents in a series of 89 procedures with a mean follow-up time in excess of 2 years, thereby adding to the scant information available in this respect and helping to properly assess the true scope of this procedure in the treatment of epiphora caused by obstruction of the lacrimal system.
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MATERIALS AND METHODS Study Population Between February 1997 and April 1999, a total of 89 polyurethane stent placement procedures were performed in 77 consecutive patients with epiphora caused by obstruction of the lacrimal system. The patient population was 20 males and 57 females, with a mean age of 53 years. The first 70 procedures have been included in a previous study (10). Epiphora was graded subjectively according to the Munk scale (12). Diagnosis of lacrimal obstruction was made by dacryocystography. Patients with grade III or grade IV epiphora and blockage of the lacrimal apparatus at the level of the lacrimal sac or duct were candidates for inclusion in the study, without regard to the length of the obstruction, the amount of time patients had the condition, or patient age. Exclusion criteria were obstruction of the common canaliculus or an atrophied lacrimal sac too small to house a stent. Patients with acute dacryocystitis received antibiotic therapy until symptoms had subsided before undergoing intervention; even so, in some cases pus was found to be present in the lacrimal sac during the procedure, although this was not regarded as a contraindication for performance of the procedure. Stent Placement Technique The procedure was performed on an ambulatory patient basis under sedation and local anesthesia. The sedative used was intravenous midazolam, and the local anesthesia consisted of infiltration with 2% lidocaine (supratrochlear nerve, infraorbital nerve, and nostril) and nasal packing impregnated with a solution of 10% tetracaine hydrochloride and epinephrine. The Song nasolacrimal duct stent set (Cook Ireland, Limerick, Ireland) was used in all cases, the set being composed of a rigid 0.018-inch ball guide wire with balls at each end, a 6-F dilator, and a polyurethane stent and pusher. The stent placement technique was basically as that described by Song et al (7,13) with certain modifications as described by Pinto et al (10). Dacryocystography was performed at the conclusion of every procedure to
verify proper stent placement and patency. The 89 procedures completed resulted in placement of 79 stents, with failure to correctly intubate the lacrimal drainage system in 10 cases. In the first 50 procedures, computed tomography (CT) was also performed systematically to assess the position of the stent in the lacrimal system, but in the remaining procedures CT was performed only in those cases in which improper placement of the stent was suspected. Maxitrol (Alcon Iberhis, Madrid, Spain) and Rhinocort (Astra España, Barcelona, Spain) were administered for 10 days after the procedure. Follow-up The postprocedural course of the 79 stents inserted was followed to the termination of the study in September 2000 (follow-up, 16 –38 mo; mean, 27 mo). Periodic clinical examinations were carried out after 10 days and at 1 month and 3 months, and thereafter every 6 months after the procedure, with dacryocystography yearly or on recurrence of epiphora. When occlusion occurred, stents were washed with saline solution in an effort to clear them before removal. Blocked stents that could not be cleared by lavage were removed after dacryocystography. During the first 2 years of the study, removal was performed by a otorhinolaryngologist and, during the final year, by the authors themselves under radiologic guidance, with patient preparation and subsequent topical treatment the same as that used for stent insertion (local anesthesia and/or sedation, plus Maxitrol and Rhinocort). Dacryocystography was also performed at the termination of each stent removal procedure. Statistical Analysis Stent survival time was estimated by means of Kaplan-Meier curves. Survival time has been reported as median survival time and by interquartile range.
RESULTS Implantation of the nasolacrimal stent failed in 10 of the 89 procedures
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undertaken (11.2%), with a final result of 79 stents placed in 67 patients (bilateral stents were inserted in four patients and two stents were inserted successively in eight patients). The cause of the obstruction was lesions in the lacrimal apparatus in all cases but one, in which there was stenosis. The location of placement was seven in the lacrimal sac, seven in the nasolacrimal duct, and the remainder at the junction between the sac and the duct. Follow-up ranged from 16 to 38 months, with a mean of 27 months. Two patients were lost to follow-up, and an additional two cases had to be excluded from the study: in one case, the stent was removed while still patent 2 months after placement because the patient developed repeated episodes of conjunctivitis with nonsterile tears; in the other case, the patient died while the stent was still in place and patent at 2 years after insertion. Of the remaining 75 cases, at the end of the study, a total of 45 stents (60%) had become occluded and 30 (40%) remained patent. Median duration of stent patency was 20 months, with interquartiles of 7 months (75% stent patency rate) and 36 months (25% stent patency rate; Fig 1). A total of 45 stents became blocked. Of these, 29 stents had been properly placed and 16 had been improperly placed, or malpositioning was regarded as likely (in most cases dorsally to the lacrimal sac according to CT and/or dacryocystography examination results) (10). All of the improperly placed stents became occluded in less than 1 year, with a mean time to occlusion of 4.4 months. For the 29 stents that had been properly positioned within the lacrimal system, the mean time to occlusion was 12.2 months. In all, 40 of the 45 occluded stents were removed. Five stents were not removed, three because the patients refused and two because adherence to the lacrimal tract made removal unfeasible. These five cases all belonged to the group of 29 stents that appeared to have been properly placed, with the longer mean time to occlusion. In all the cases in this group, dacryocystography performed before removal demonstrated a reduction in the size of the lacrimal sac as compared to the results obtained on dacryocystography per-
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Figure 1. Stent patency: median duration of stent patency was 20 months (interquartile range ⫽ 7; 36). ⬜ ⫽ SE.
formed in these same patients before stent placement (Fig 2). In eight patients in our study, a second stent was inserted after occlusion of the first. Ten of the stents that did not become blocked required lavage during follow-up to maintain patency. Clinically, 26 of these 30 cases were free from epiphora, three exhibited occasional epiphora, and one had grade IV epiphora. Overall, clinical symptoms failed to correlate with the radiologic findings during follow-up in six cases in our study. In four cases in which dacryocystography showed the stents to be occluded, the patients reported no symptoms of epiphora (these cases were all counted as occluded stents, and removal of the stents was recommended to the patients); conversely, in two patients who had grade IV epiphora, the dacryocystography findings showed the stents to be fully patent.
DISCUSSION The primary object of this study was to assess the usefulness of polyurethane nasolacrimal stents in the long-term treatment of epiphora caused by blockage of the lacrimal drainage system. The technical aspects of stent placement and short-term re-
sults have already been published and discussed in previous articles using material essentially similar to the data compiled over the longer period of follow-up reported here (10). During a mean follow-up period of 2 years and a minimum follow-up duration of 16 months, we achieved a 40% patency rate in a total of 75 stents, nearly all inserted to treat complete obstruction of the lacrimal sac or duct. No attempt was made to carry out periodic lavage to avert blockage of the stents. Comparing our results with the literature results failed to yield equally long follow-up periods but did disclose occlusion rates of 25% at 7 months (11), 31% at 1 year (8), and 37% at 1 year (10). Better results have been achieved by routinely carrying out lavage of inserted stents. For instance, Lee et al (14) reported an occlusion rate of only 8% after a mean follow-up of 22 months for stents inserted without the use of radiologic guidance but with lavage at 1, 3, 6, and thereafter every 6 months after placement; and Lanciego et al (15) achieved an occlusion rate of 15% for 183 stents after follow-up periods of 8 –730 days. No series has had a follow-up as consistently as long as ours, but on extrapolation the results attained by other workers would seem to be better than
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our results overall. Two factors may have come into play in this respect: close ophthalmologic follow-up with periodic lavage of stents and low malpositioning rates. A certain portion of stents appeared to be improperly positioned or to traverse a false trajectory outside the normal lacrimal system. In our study, these stents have been counted as a separate category. False trajectories of this kind are created by the guide wire when trying to negotiate the lacrimal apparatus, which is ordinarily torn before the lacrimal sac is reached (13). This results in the positioning of stents dorsally and/or medially to the lacrimal sac, and such stents tend to be particularly vulnerable to early occlusion (10,11). Nevertheless, it is hard to identify this problem with any degree of certainty, even when CT and dacryocystography are used, and in most reported series such cases have not been separated from the category of occluded stents as a whole. In our series, 19% of all the stents inserted were malpositioned, and the improperly placed stents had a mean time to occlusion of 4.4 months. Certain technical procedures, such as the use of flexible guide wires (11) and selection of patients to exclude those who have alterations of the canaliculi (15), help reduce the rate of improper stent placement. Even after excluding those stents that had been improperly positioned and, as a result, displayed a tendency to become blocked early, based on the overall experience gained in stent placement in other anatomic structures, all nasolacrimal stents can be expected to become occluded over time. In our series, the mean time to occlusion was 12.2 months for the properly positioned stents only and 9.2 months for all stents combined, with no distinctions made based on proper or improper positioning. The cause of occlusion may be blockage of the stent itself ascribable to clots, detritus, or mucus, or blockage may be ascribable to the gradual spread of inflammatory stenotic lesions in the canaliculi in the lacrimal system above the stent or to the growth of granulation tissue in the lacrimal sac in reaction to the presence of the stent. This last-mentioned cause of occlusion becomes more frequent over time (8,11) and gives the greatest cause for concern, on the one hand because it
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Figure 2. Instance of the reduction in size of the lacrimal sac. (a) Dacryocystogram in a patient with grade IV epiphora. This figure shows obstruction at the junction of the sac and the nasolacrimal duct, an irregularly shaped lacrimal sac, and duplication and stenosis of the common canaliculus. (b) Placement of a nasolacrimal stent, resolving the epiphora; dacryocystography performed immediately after insertion showed the stent to be patent. (c) Control dacryocystogram performed 2 months after the procedure because of occasional recurrence of epiphora in this patient, showing the stent to be patent. The stent was washed on three separate occasions for that same reason, with symptoms improving after washing. (d) Dacryocystogram obtained at 1 year after stent placement, showing recurring, increasingly more frequent grade III–IV epiphora. Occlusion did not respond to lavage, and the stent was removed. (e) Dacryocystogram obtained after stent removal showing an appreciable reduction in the size of the lacrimal sac as compared to the size recorded on examination before stent placement.
reduces the size of the lacrimal sac and therefore makes the performance of future dacryocystorhinostomy more difficult, and on the other because, as we have seen in our series, it may lead to adherence of the stent to the lacrimal tract, making removal impossible (Fig 3). We have not kept an exact
record of the number of cases in which this problem arose, but the situation was commonly encountered in cases in which removal of stents that had been in place for more than a year was attempted and, indeed, two cases required us to leave occluded stents in place. The literature has drawn atten-
tion to the formation of granulation tissue around inserted stents (11), but there have been no reports implicating this as a source of difficulty affecting stent removal, perhaps because of shorter follow-up periods. Conversely, the lacrimal drainage system has been reported not to remain patent after re-
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Figure 3. Difficulty in stent removal. (a) Placement of a nasolacrimal stent in the left lacrimal system in a 64-year-old patient who had grade IV epiphora caused by obstruction of the lacrimal drainage system at the junction of the lacrimal sac and the nasolacrimal duct. (b) Occlusion of the stent 3 years after placement. (c) Elongation of the stent and difficulty in removal because the stent had adhered to the lacrimal sac. The stent was eventually removed.
moval of occluded stents (patency rates of 15%–30% in the medium term) (8,11), although, again, there are also apparent discrepancies in the results achieved, with reported patency rates of 89% at 15–540 days after the removal of occluded stents (15). Therefore, certain literature reports to the contrary notwithstanding, follow-up in our series appears to demonstrate that the gradual blockage of nasolacrimal stents is inescapable. In the circumstances, dacryocystoplasty is another interventional therapeutic option. However, the rate of immediate resolution of the epiphora of 40%– 80% is lower than that attained with use of stents, and the rate of recurrence at 1 year is higher than 50% in cases of complete obstruction of the lacrimal apparatus (3– 6). Better results have been achieved in cases of stenotic lesions. For instance, Jansen (16) obtained long-term (20 mo) lacrimal tract patency rates of 70%– 80% in a series with an overall stenosis rate of 73%. Based on literature reports published to date, the efficacy of dacryocystoplasty would not appear to be comparable to that of nasolacrimal stents in cases of complete obstruction of the lacrimal system.
Finally, surgery appears to be more effective, with cure rates of 90% for surgical dacryocystorhinostomy and 70% for endonasal laser dacryocystorhinostomy at 1 year (1,2), although there have been no reports of follow-up periods longer than 1 year. In conclusion, treatment of idiopathic obstruction of the lacrimal system and obstruction secondary to recurrent episodes of inflammation is a difficult issue. The long-term results achieved using polyurethane nasolacrimal stents have not been encouraging. To improve stent efficacy work on several different aspects of nasolacrimal stents would appear to be called for (periodic lavage, prevention or curbing of infection of the lacrimal system, combined treatment with dacryocystoplasty and a stent, use of stents for temporary dilatation followed by removal before blockage due to tissue growth, and so forth). Nevertheless, for the time being, until comparative trials contrasting final results in the treatment of idiopathic obstruction of the lacrimal system achieved with use of dacryocystorhinostomy and interventional radiologic methods become available, the use of stents should not be recommended as a final treatment.
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14. Lee JS, Jung G, Oum BS, Lee SH, Roh HJ. Clinical efficacy of the polyurethane stent without fluoroscopic guidance in the treatment of nasolacrimal duct obstruction. Ophthalmology 2000; 107:1666 –1670. 15. Lanciego C, De Miguel S, Perea M, et al. Nasolacrimal stents in the management of epiphora: medium-term results of a multicenter prospective study. J Vasc Interv Radiol 2001; 12:701–710. 16. Janssen AG, Mansour K, Bos JJ. Obstructed nasolacrimal duct system in epiphora: long-term results of dacryocystoplasty by means of balloon dilatation. Radiology 1997; 205:791–796.