Is routine histological tissue sampling during endoscopic dacryocystorhinostomy advantageous? A retrospective analysis of 213 patients

The prevalence of tumours of the lacrimal duct system is very low (1.43%) (1). Tumours developing in this region cover a large spectrum of entities that fall into two categories: primary epithelial neoplasms and primary non-epithelial neoplasms. The typical symptoms of a dysfunction of the lacrimal duct system, such as epiphora, secretion, and swelling of the lacrimal sac, can be caused by stenosis or inflammation as well as by benign and malignant proliferative diseases of the tear duct system. This article is protected by copyright. All rights reserved.

Is routine histological tissue sampling during endoscopic dacryocystorhinostomy advantageous? A retrospective analysis of 213 patients 1

| INTRODUCTION
The prevalence of tumours of the lacrimal duct system is very low (1.43%). 1 Tumours developing in this region cover a large spectrum of entities that fall into two categories: primary epithelial neoplasms and primary non-epithelial neoplasms. The typical symptoms of a dysfunction of the lacrimal duct system, such as epiphora, secretion and swelling of the lacrimal sac, can be caused by stenosis or inflammation as well as by benign and malignant proliferative diseases of the tear duct system. Malignant disease must always be suspected when there are clinical signs such as telangiectasias over the swelling and serous-sanguineous secretion. [2][3][4][5] Besides primary tumours, in rare cases, metastases or secondary tumours can also develop in the lacrimal duct system. In most cases, neoplasms of the tear duct system are detected very late and often accidentally. 2,6 To restore patency to a stenotic lacrimal duct system in patients who present with chronic or intermittent epiphora, endoscopic dacryocystorhinostomy (DCR) can be considered as the golden standard of treatment. In our department, tissue was not routinely sampled for histological examination during endoscopic DCR. In the literature, the relevance of routine lacrimal sac biopsy is discussed controversially, although malignant proliferative disease cannot be excluded with certainty without histological examination. Merkonidis et al. 7 show that a biopsy is only necessary if diseases other than chronic inflammation are suspected pre-or intraoperatively. In contrast, Koturovic et al. 8 postulated that a routine biopsy of the lacrimal sac is highly valuable, as a previously suspected diagnosis can be confirmed or unexpected diseases revealed without further inconvenience to the patient. 7 The aim of this retrospective study was to determine the usefulness of routine tissue collection during surgery for histological examination. On the basis of the histopathological reports, we calculated the rate of incidental findings of an occult benign or malignant tumour that was not suspected before or during surgery.

| Ethical considerations
The study was approved by the institutional review board of the Medical University of Graz (approval number: 27-192 ex 14/15) and complies with the Declaration of Helsinki.

| Statistical analysis
The data underwent descriptive and frequency distribution analysis with SPSS (IBM SPSS Statistics 23). The Kolmogorov-Smirnov test was performed to test for normal distribution. The following parameters were analysed with cross-tabulation: tissue samples (yes/no) and incidental findings of benign or malignant proliferative disease (yes/ no). Considering the whole study population (N = 364), the rate of incidental tumour finding would be 1.4%, given the fact that the patients without intraoperative tissue sampling did not show a tumour in the follow-up period. A shortcoming of the study is its retrospective character. Upon analysis of the surgical reports, we found that no nasolacrimal mucosa was harvested for histology when the surgeon had only opened the nasolacrimal sac without partially resecting its medial wall. However, in the other 213 patients, in whom the nasolacrimal sac was partially resected medially and the mucosa marsupialised with the nasal mucosa, the harvested tissue was sent for histology. In none of these cases did the surgeon suspect a proliferative disease intraoperatively.

| CONCLUSION
In spite of the relatively low overall prevalence of malignant tumours of the nasolacrimal duct, the rate of incidental tumour findings in the present study justifies routine histological work-up, particularly as tissue sampling during DCR does not in any way inconvenience the patient.

None to declare
The usefulness integrity testing in children: A single institution experience of 86 tests over a period of 20 years 1

| INTRODUCTION
Cochlear implants are widely accepted as the best management option for both adults and children with a severe-profound hearing loss who do not benefit from traditional hearing aid amplification.
There are over 350 000 cochlear implant recipients worldwide 1 and despite the very high reliability, these devices do occasionally fail.
Internationally, device failure rates have been reported to vary between 3% and 5% in large centre studies. [2][3][4] An important part of every clinical programming session is the measurement of impedances, that is the level of connectivity between the electrodes and the neuronal tissue. This test allows clinicians to determine how many channels can be used for programming. If a problem develops, whether in the device itself or the device-tissue interface, an impedance test can be the first indicator of a device failure.

Auditory problems
The integrity testing is performed at the endpoint of troubleshooting any suspected problem. The testing is conducted onsite by the manufacturer using specific equipment that can connect and assess the implant in-situ. It is a time-consuming process as it often requires an additional visit by the manufacturer to the clinic. CORRESPONDENCE: OUR EXPERIENCE