Abstract
Purpose
The purpose of this study is to observe the effect of intraoperative topical application of mitomycin C (MMC) on the results of endoscopic dacryocystorhinostomy.
Design
This is a prospective, randomized, controlled, single-blind study.
Settings
Hospitalized treatment was done in a tertiary medical college hospital and research center that deals with a predominantly rural population.
Patients
Patients with primary acquired postsaccal obstruction causing chronic dacryocystitis were considered.
Methods
A total of 38 patients were randomized into either a mitomycin group or a control group. Both of these groups were subjected to an identical surgical procedure, except that 0.2 mg/dL of MMC was used in the mitomycin group, whereas normal saline was used in the control group. The follow-up period was at least 6 months. An asymptomatic patient with a visible stoma at nasendoscopy and free flow of saline into the nose with lacrimal syringing after 6 months after surgery was used as criteria for defining a successful result.
Results
The success rate was 82.3% when MMC was used and 85.7% among the controls ( P > .05). Granulations, adhesions, and obliterative sclerosis occurred in a similar number of patients of both groups. However, granulations and adhesions did not have a bearing on the success rate in either group.
Conclusion
Mitomycin C did not appear to influence the occurrence of granulations, synechiae, or obliterative sclerosis, nor did it alter the success rate significantly.
1
Introduction
Chronic dacryocystitis is a commonly encountered condition and can be treated either by external dacryocystorhinostomy (Ex-DCR) or by endoscopic endonasal dacryocystorhinostomy (En-DCR). Intranasal dacryocystorhinostomy was first described by Caldwell in 1893 . Almost a century later, McDonogh and Meiring described the En-DCR. Since then, the advantages of En-DCR over Ex-DCR have been well established. An En-DCR will avoid a facial scar, will not interfere with the lacrimal pump mechanism, preserves the medial canthal ligament, and carries a shorter operating time.
Although En-DCR has several advantages over Ex-DCR, the results are similar , hence, the need for adjuvant measures. Several adjuvant measures have been reported . However, these measures are more demanding and have not contributed significantly to the results .
Recurrence is attributed to obliterative scarring, granulations, and adhesions at the stomal site after En-DCR. Mitomycin C (MMC) is an antibiotic isolated from Streptomyces caespitosus by Wakaki et al in 1958 . When applied topically at the operative site, it inhibits fibroproliferative activity . This property of MMC is used by ophthalmologists in pterygium excision and trabeculectomy. In published literature, there are few controlled trials in which MMC has been used as an adjunct to En-DCR . Furthermore, the results of these trials do not concur, and the role of MMC remains inconclusive. This study is in the hope that further controlled trials may provide more convincing information on the role of intraoperative topical application of MMC in En-DCR.
2
Patients and methods
This is a randomized, controlled, single-blind study wherein all patients referred by the Department of Ophthalmology with a diagnosis of chronic dacryocystitis due to primary acquired postsaccal obstruction of the lacrimal apparatus were considered. Patients younger than 15 years and those with a history of previous lacrimal sac surgery were excluded.
Institutional consent form was used in which additions were made regarding the inclusion of patients in a study where MMC was used as an adjunct to a standardized surgical procedure. In addition, it was conveyed to the patients that the use of MMC in this procedure was not unprecedented and that the concentration of MMC (0.2 mg/mL) was less than that used in previous studies , in which no adverse effects were observed.
A total of 38 patients were randomized for either En-DCR with topical application of MMC (mitomycin group) or En-DCR with topical application of normal saline (control group). A combined sample size of 38 patients was arrived at by using the power approach with a power of 90% and an assumed effect size of 35% between the mitomycin and control groups. Random allocation of patients to the mitomycin group or the control group was done by allowing each patient to choose from a bunch of unbiased chits. This was done after counseling and before admission for surgery.
Mitomycin group consisted of 17 patients, and control group had 21 patients. All of these patients were treated by the Department of Otorhinolaryngology of Sri Devaraj Urs Medical College Hospital between 2003 and 2009.
2.1
Surgical technique
All patients were subjected to a standardized surgical technique. Under sedation and local anesthesia, the middle turbinate (MT) is infractured. The medial surface of the lacrimal fossa was noted just anterosuperior to the axilla of the MT. An oval patch of mucoperiosteum measuring about 2 cm vertically and 1 cm anteroposteriorly surrounding the maxillary line is removed using the otologic drill with a protective sleeve. Bone removal is carried out until the external periosteum of the lacrimal bone and medial wall of lacrimal sac is reached.
Using a Kerrison’s punch, the bony window is widened circumferentially until the medial wall of lacrimal sac is exposed for about 8 mm above the axilla of MT to just above the insertion of inferior turbinate ( Fig. 1 ). A Bowman lacrimal probe is passed into the lacrimal sac through the inferior punctum and canaliculus. The limits of the lacrimal sac are probed, and the medial wall of sac is tented medially ( Fig. 2 ). The tented medial wall of sac is removed completely. For patients belonging to the mitomycin group, a cottonoid soaked in 0.2 mg/mL of MMC was placed over the raw edges of stoma for 10 minutes. In the control group, normal saline was used in place of MMC. Selective nasal packing was done, and complete hemostasis was achieved.
The nasal pack was removed the next day, and patient was discharged from hospital. The patients were reviewed on the seventh postoperative day with nasal endoscopy and removal of crusts and debris. Stomal patency was determined subjectively by resolution of epiphora and objectively by free flow of saline with lacrimal syringing during nasal endoscopy. Patients were reviewed at monthly intervals for at least 6 months ( Fig. 3 ).
2
Patients and methods
This is a randomized, controlled, single-blind study wherein all patients referred by the Department of Ophthalmology with a diagnosis of chronic dacryocystitis due to primary acquired postsaccal obstruction of the lacrimal apparatus were considered. Patients younger than 15 years and those with a history of previous lacrimal sac surgery were excluded.
Institutional consent form was used in which additions were made regarding the inclusion of patients in a study where MMC was used as an adjunct to a standardized surgical procedure. In addition, it was conveyed to the patients that the use of MMC in this procedure was not unprecedented and that the concentration of MMC (0.2 mg/mL) was less than that used in previous studies , in which no adverse effects were observed.
A total of 38 patients were randomized for either En-DCR with topical application of MMC (mitomycin group) or En-DCR with topical application of normal saline (control group). A combined sample size of 38 patients was arrived at by using the power approach with a power of 90% and an assumed effect size of 35% between the mitomycin and control groups. Random allocation of patients to the mitomycin group or the control group was done by allowing each patient to choose from a bunch of unbiased chits. This was done after counseling and before admission for surgery.
Mitomycin group consisted of 17 patients, and control group had 21 patients. All of these patients were treated by the Department of Otorhinolaryngology of Sri Devaraj Urs Medical College Hospital between 2003 and 2009.
2.1
Surgical technique
All patients were subjected to a standardized surgical technique. Under sedation and local anesthesia, the middle turbinate (MT) is infractured. The medial surface of the lacrimal fossa was noted just anterosuperior to the axilla of the MT. An oval patch of mucoperiosteum measuring about 2 cm vertically and 1 cm anteroposteriorly surrounding the maxillary line is removed using the otologic drill with a protective sleeve. Bone removal is carried out until the external periosteum of the lacrimal bone and medial wall of lacrimal sac is reached.
Using a Kerrison’s punch, the bony window is widened circumferentially until the medial wall of lacrimal sac is exposed for about 8 mm above the axilla of MT to just above the insertion of inferior turbinate ( Fig. 1 ). A Bowman lacrimal probe is passed into the lacrimal sac through the inferior punctum and canaliculus. The limits of the lacrimal sac are probed, and the medial wall of sac is tented medially ( Fig. 2 ). The tented medial wall of sac is removed completely. For patients belonging to the mitomycin group, a cottonoid soaked in 0.2 mg/mL of MMC was placed over the raw edges of stoma for 10 minutes. In the control group, normal saline was used in place of MMC. Selective nasal packing was done, and complete hemostasis was achieved.
