3.2.2.1Silicone “Cones” (Lacrimal Duct Stent, Bess, Berlin)

According to Freigang, a similar approach for obtaining a higher success rate by means of stenting is the lacrimal duct stent. After placement of the classical silicone stent (lacrimal duct stent, Bess, Berlin) a silicone cone is introduced via the nasal oriÞce using a special applicator. In addition to Þxing the stent, it prevents the formation of adhesions between the middle turbinate and the lateral nasal wall. This procedure carries the same risks as classical stenting. The tendency to form crusts can be described as slightly greater. Systematic studies of the method have not yet been performed.

3.2.4 Use of Mitomycin C for EDCR

Mitomycin C is an antineoplastic antibiotic, which inhibits collagen synthesis by Þbroblasts. Following positive experiences in ophthalmology mitomycin C is increasingly used in ENT surgery in cases where postoperative cicatricial stenosis is a major problem, e.g. in laryngotracheal stenoses, choanal atresia and lacrimal stenosis.

Zilelioglu et al. found success rates (symptom-free + irrigation positive) of 77.3% (17 of 22) with mitomycin C and 77.8% without (14 of 18), 9Ð27 months after EDCR [101]. They used 0.5 mg/mL for 2.5 min and stented the lacrimal ducts for 4Ð6 months. The size of the DCR shrank from 35.7 to 1.7 mm2 in the mitomycin C group and from 35.3 to 1.5 mm2 in the control group. Thus, overall there was no difference.

Camara on the other hand reported in a letter to the editor that he was able to increase the success rate from 90 to 95.4% with the use of mitomycin C (0.5 mg/mL) [13, 14]. He had performed more than 325 endoscopic laser-assisted DCR procedures. In an original paper he then reported on 123 patients who were operated on by Hol:YAG laser using 0.5 mg/mL mitomycin C for 5 min. The silicone stenting was removed after 3 months. Thirty to sev- enty-two months post-operatively he achieved a success rate of 99.2% measured by symptoms and positive irrigation. For comparison he used a historic control group in which a success rate of 89.6% was achieved. What is remarkable is, by comparison,

the very high success rates obtained with the laserassisted technique.

Kao et al. examined 14 patients with 15 external operations, who were randomly allocated to mitomycin C (0.2 mg/mL for 30 min) or a control group [34]. Six months post-operatively all mitomycin C patients (N = 7) were symptom-free, while in the control group one patient had renewed epiphora and two had adhesions. The surgically created ostium shrank from 66.28

± 11.06 mm2 to 27.10 ± 5.78 mm2 (mitomycin C) after 6 months vs. 65.55 ± 8.66 mm2 to 10.83 ± 3.37 mm2 (control group). The difference was statistically signiÞcant.

In a prospective randomised study with 88 external operations, 95.5% of the patients in the mitomycin C group (0.2 mg/mL for 30 min) and 70.5% of the control group were complaint-free, 10 months post-operatively [47]. In the control group a marked improvement was seen in an additional 18%. The difference was signiÞcant.

You et al. treated 46 patients with 50 operations in three groups [99]: classical external DCR, additional mitomycin C 0.2 mg/mL, additional mitomycin C 0.5 mg/mL for 5 min.

After 23Ð42 months (average 35.2 months) 83, 100 and 94% of the lacrimal ducts, respectively, were positive to irrigation (not signiÞcant). The size of the intraoperative opening measured endoscopically immediately post-operatively was 53.4 ± 8.4, 50.6 ± 8.9 and 52.4 ± 8.6 mm2 respectively. At the follow-up examination it had shrunk to 13.2 ± 2.7, 22.2 ± 5.0 and 20.6 ± 4.5 mm2 respectively. Application of mitomycin led to a statistically signiÞcantly larger opening independent of the concentration.

Altogether there is growing evidence that mitomycin C can successfully reduce stenotic processes resulting from scarring. In lacrimal surgery there are no established standards to date regarding the indications and therapeutic regimens.

As with adequate operative technique, the conventional procedure carries a success rate of more than 90%, it will be difÞcult to measure any additional beneÞt. The use of mitomycin C is acceptable for relapses and difÞcult individual cases. It should on no account be used to compensate for inadequate operative technique. No complications of intranasal use of mitomycin C have been described to date. Histological studies showed thinning of the epithelium with intracytoplasmic vacuoles and loose connective tissue with fewer cells [81].

As the most recent modiÞcation, the antineoplastic drug ßuorouracil, which also inhibits Þbroblast proliferation, was used for the Þrst time by Bakri et al. to reduce the formation of granulation and scar tissue [4]. In a randomised study, the results of laser assisted DCR (holmium laser) was compared with 5-min dabbing of the rhinostomy site with ßuorouracil or saline. After a minimum follow-up of 12 months 65 of the 85 cases (76%) in the ßuorouracil group and 52 of the 82 cases in the control group (63%) were successful. The difference was not statistically signiÞcant.

The author uses mitomycin C not in primary cases of post-saccal stenosis, but in revision cases with scarring of the DCR opening or in the lacrimal sac.

¥The use of topical steroids to obtain a positive inßuence on wound healing with reduction of the oedema phase and granulations and a hope for reduction in scar formation is established in the follow-up treatment after paranasal sinus surgery. We therefore also follow this practice in endonasal DCR and continue application of the steroids until healing is obtained.

¥Almost all therapists prescribe eye drops containing antibiotics and/or corticoids for 2 weeks. This appears meaningful, although proof of their effectiveness is lacking.

¥It should be noted that an excessively large DCR can cause increased symptoms in the patient as there is air regurgitation through the lacrimal ducts to the eye when the nose is blown.

Post-operatively, great care must be taken to avoid the development of adhesions between the middle turbinate or septum and lacrimal sac or lateral nasal wall. SigniÞcant granulations or Þbrin depots should be removed early and any tendency to lateralisation of the turbinate be opposed. Therefore the follow-up, with not too frequent but regular and resolute cleaning, i.e. removal of Þbrin, crusts and granulations, is important. However, this is not supported by hard evidence in the form of studies. The same applies to all other modalities of follow-up treatment. A theoretical consideration of the principles of action, potential beneÞts and risks, indicates that the following measures are meaningful. They should be modiÞed in individual cases if necessary.

Endoscopic endonasal removal of the Fibrin clots and crusts is performed Þrst after 7 days after DCR and repeated weekly if necessary. Patients are allowed to rinse their nose with saline once or twice a day from the second week. Patients are not allowed to blow their nose for 1 week after surgery and they are asked to perform regular gentle massages of the external aspect of the lacrimal sac (inner angle of the eye) to facilitate drainage.

¥Systemic antibiotics are not routinely necessary. In the case of operation of acute dacryocystitis an antibiotic sufÞciently effective against streptoand staphylococci is given for 7Ð10 days, depending on how soon the cellulitis subsides. This can easily be monitored clinically.

In spite of all the advantages, the published results are not better, even in some cases slightly worse, than those of the external operation [35, 93, 94]. With the endonasal procedure, the success rates are usually around 80Ð90% and more, although here too comparison of the studies or summarising several studies is not possible on account of differences between details of the operation techniques, and differences in data collection and evaluation of outcome. There is no doubt that in experienced and self-critical hands, the results of endonasal DCR will reach 95% of the specialised ophthalmological centres (Fig. 3.6 and 3.7).

Fig. 3.6 View into the wide open lacrimal sac on the right side 6 months after endonasal DCR (45¡ endoscope). The fornix of the sac is nicely visible