Otolaryngology - Head & Neck Surgery Supplement - 2020 Official Program Abstracts - P237

Poster Presentations	

Landmines and Improvised Explosive
Devices: Overlooked Otologic Injuries in
Colombia
Melissa Castillo-Bustamante (Presenter); Marc Polanik;
Elliott D. Kozin, MD; Aaron K. Remenschneider, MD, MPH
Objectives: Colombia has reported the largest armed conflict
in Latin America, where the use of landmines (LMs) and
improvised explosives devices (IEDs) has been the source of
significant civilian injury. To date, the prevalence of traumatic
ear injury in Colombian citizens has not been well studied. The
aim of this study is to review the national database of citizens
affected by LMs/IEDs to determine the prevalence of otologic
injury.
Methods: Retrospective review of Presidential Program
for Comprehensive Action against Anti-Personnel Mines
(PAICMA) database of individuals affected by LMs/IEDs
from 1990 to 2019. Within the data set, the prevalence of LM/
IED exposure, otologic injury, and occurrence in conjunction
with limb injury were analyzed.
Results: Over the 30-year period, 11,769 individuals were
affected by LMs/IEDs and 2295 (19.5%) resulted in fatality.
In survivors, limb injury occurred in 5194 (44%). Civilian
adult men working in mountain areas (62%) were mainly
affected by LMs and children in rural areas (16%) by IEDs.
Documentation of otologic injury occurred in only 328 survivors. Notation of acoustic trauma and hearing loss were found
commonly in individuals with upper and lower limb loss
(54%). Both LMs and IEDs resulted in comparable rates of
bilateral acoustic trauma (37% vs 42%), bilateral hearing loss
(33% vs 14%), and bilateral tympanic membrane perforation
(13% vs 14%).
Conclusions: In Colombia, LMs/IEDs are an important
source of ongoing morbidity and mortality. Otologic injury is
likely significantly underreported and may be an underappreciated consequence of blast trauma. Initial and follow-up otologic evaluation and care should be routinely performed in
blast-injured patients.

Lateral Skull Base Tumors in the Pediatric
Population: A Single Institutional Experience
Sarah M. Tittman, MD (Presenter); Nauman F. Manzoor, MD;
Marc L. Bennett, MD; David S. Haynes, MD; Alejandro
Rivas, MD
Objectives: Lateral skull base tumors in the pediatric population are rare, and their management is complex. Here, we
report our contemporary institutional experience in the management of these lesions.
Methods: Retrospective review of pediatric lateral skull
base tumors at a single institution between 2002 and 2018.
Results: Eleven cases (female = 7, 64%) with mean age of
11 years (±5.4; range, 1-18 years) were identified retrospectively. Seven tumors (64%) were located on the left side, and
the mean maximal tumor dimension was 2.9 (±1.1) cm. The
surgical approaches included the retrosigmoid (n = 4), translabyrinthine (n = 4), transpetrosal (n = 2), and middle fossa (n
= 1). Surgical pathology was diverse and included vestibular
schwannomas (n = 5), facial nerve schwannoma (n = 1), vagal
schwannoma (n = 1), pilocystic astrocytoma (n = 1), pontine
arteriovenous malformation (n = 1), epidermoid cyst (n = 1),
and a juvenile xanthogranuloma (n = 1). The extent of resection included gross total resection (n = 7), near total resection
(n = 1), and subtotal resection (n = 3). Complications included
surgical site infection (n = 2), cerebrospinal fluid leak (n = 1),
pseudomeningocele (n = 1), and cranial neuropathy (n = 3).
One patient required postoperative stereotactic radiation, and
1 patient required postoperative chemotherapy.
Conclusions: Management of lateral skull base and posterior fossa tumors in the pediatric population is challenging
because of its rarity and diverse nature of pathologies.
Microsurgical resection of lateral skull base tumors as part of
multidisciplinary management is safe, with minimal morbidity.
L-N-Acetylcysteine and Dexamethasone in
Combination Provides Otoprotection for
Electrode Insertion Trauma
Adrien A. Eshraghi, MD, MSc (Presenter)
Objectives: The inner ear trauma caused by cochlear implant
electrode insertion trauma (EIT) results in initiation of programmed cell death, which leads to loss of residual hearing.
The goal of this study is to test the efficacy of a combination
of these L-N-acetylcysteine (L-NAC; an antioxidant) and
dexamethasone (Dex; a steroid) to provide otoprotection
against EIT and determine appropriate dosages employing in
vitro and in vivo models.
Methods: Organ of Corti explants were dissected from P-3
rats and subjected to EIT followed by treatment with L-NAC
or Dex either alone or in combination. In vivo, guinea pigs
were treated with L-NAC or Dex either alone or in combination followed by implantation. Hearing thresholds were determined by auditory brainstem recordings (ABRs) and distortion
product otoacoustic emissions (DPOAEs) on different days

Otology/Neurotology

Methods: A prospective cross-sectional study in a tertiary
care hospital was conducted for 1 year, and 145 patients in the
age group 12 to 60 years were recruited. Inclusion criteria
included all patients with CSOM (safe) and (unsafe) who
underwent surgical management. Specimens were collected
and sent for bacterial and fungal isolation, culture of the specific isolate was assessed for its ability to form biofilm in
vitro, and quantification was performed.
Results: Biofilm formation was seen in 28 of 145 patients
(17/123 mucosa, 11/22 squamosal). Pseudomonas, Escherichia
coli, Staphylococcus aureus, Acinetobacter, Citrobacter, and
Morganella were the microbes involved.
Conclusions: Biofilms play an important role in the pathogenesis of CSOM. A clear understanding of their role in pathogenesis will help us formulate rational strategies to prevent
their formation and in their treatment.

P237
Otolaryngology - Head & Neck Surgery Supplement - 2020 Official Program Abstracts

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