Electric compound action potentials (ECAPs) and impedances in an open and closed operative site during cochlear implantation.

INTRODUCTION: In patients undergoing cochlear implantation, intraoperative measures of impedance and electrically evoked compound action potentials (ECAPs) are used to confirm device integrity and electrode array position. However, these electrophysiological parameters have been shown to decrease over time, with a small decrement observable as early as 24 h post implantation and becoming more apparent after 6 months. Whether the intraoperatively measured impedances and ECAPs recorded immediately after electrode insertion versus later in the operation or in an open versus closed operative site vary has not been documented. Such variation in measurement procedure may affect the ultimate operative outcome. PATIENTS AND METHODS: Between February and October 2016, 38 patients received a cochlear implant (Cochlear®), with half receiving a CI 522 device and the other half receiving a CI 512 device. These patients were distributed into three groups. In the first (group A; n = 21), the impedance and threshold neural response telemetry (tNRT) measures were taken before (M1) and after cutaneous suture (M2), whereas in the second group (group B; n = 11) they were taken twice in the open operative site, once at the time of electrode insertion (M1) and then again 10 min later (M2). The last group (group C; n = 6) was measured only once after a 10 min waiting time before closing the operative site. RESULTS: tNRTs of both group A and B were significantly higher at M1 than measured at M2. The magnitude of change in tNRT did vary significantly by group (P = .027) with group A having a bigger decrease than group B. For impedances there was evidence for a significant difference in M2 between the three groups (P = .012), with group C having significantly higher values compared to group A and B. CONCLUSION: Intraoperative tNRT measures change significantly over time, including within the first 10 min of implantation. One underlying etiology of this phenomenon for tNRTs seems to be the condition of the surgical site whereas changes of impedances can be best explained by the 'electrochemical cleaning' theory associated with the first stimulation of the electrode. However, for both impedances and tNRTs there also is an important impact of time as well as of acute perioperative changes in electrical conductivity.

A histopathological connection between a fatal endolymphatic sac tumour and von Hippel-Lindau disease from 1960.

OBJECTIVE: To highlight a case from 1960 connecting endolymphatic sac tumour and von Hippel-Lindau disease. CASE REPORT: In 1960, a 24-year-old woman presented with unilateral hearing loss, pulsatile tinnitus and a mass visible on otoscopy. The patient underwent surgical biopsy, which was complicated by haemorrhage, and ultimately resulted in death. At autopsy, a destructive temporal bone neoplasm with cystic and papillary architecture was observed that had eroded into the otic capsule. Intra-abdominal lesions consistent with von Hippel-Lindau disease were also observed, and the surgeon postulated a connection between endolymphatic sac tumour and von Hippel-Lindau disease. METHOD: A review of the literature was carried out using PubMed. CONCLUSION: Endolymphatic sac tumours are rare neoplasms of the temporal bone that can occur sporadically or as part of von Hippel-Lindau disease. The connection between endolymphatic sac tumour and von Hippel-Lindau disease was first proposed in 1988 and formalised in 1997. We believe that this case represents the first documented connection between endolymphatic sac tumour and von Hippel-Lindau disease.

Anatomic and Quantitative Temporal Bone CT for Preoperative Assessment of Branchio-Oto-Renal Syndrome.

We describe the temporal bone computed tomography (CT) findings of an unusual case of branchio-oto-renal syndrome with ectopic ossicles that are partially located in the middle cranial fossa. We also describe quantitative temporal bone CT assessment pertaining to cochlear implantation in the setting of anomalous cochlear anatomy associated with this syndrome.

Unique microbiology of chronically unstable canal wall down tympanomastoid cavities: considerations for surgical revision.

OBJECTIVE: To review the microbiology of open tympanomastoid cavities in patients who underwent revision surgery due to chronic instability. METHODS: This paper describes a retrospective chart review of surgical revision cases of chronically unstable open mastoid cavities. Patient records from 2000 to 2010 were reviewed for the type of organism cultured, antimicrobial resistance and the presence of cholesteatoma. RESULTS: In total, 121 revision surgical procedures were performed on 101 patients. Seventy-nine procedures involved culture specimen processing, 37 of which were positive. The most commonly cultured organism was Staphylococcus aureus, which was more than twice as common as any other pathogen. The presence of cholesteatoma had no impact on the likelihood of a positive culture or polymicrobial culture. Antimicrobial-resistant pathogens were uncommon. CONCLUSION: A positive culture was not an overwhelmingly common characteristic of unstable tympanomastoid cavities. Furthermore, antimicrobial resistance did not appear to play an essential role in leading patients towards revision open mastoid surgery.

Surgical anatomy of the anterior supralabyrinthine air cell tract.

INTRODUCTION: In order to safely explore the medial wall of the attic, a working knowledge of the anatomy of the anterior supralabyrinthine air cell tract is required. AIM: To clarify the surgically relevant anatomical relationships that comprise the anterior supralabyrinthine air cell tract. MATERIALS AND METHODS: Surgical dissection of 10 fresh cadaveric temporal bones was undertaken, including measurement of distances between the key anterior supralabyrinthine anatomical landmarks. RESULTS: The following mean distances were calculated: the labyrinthine segment between the geniculate ganglion and the ampullated end of the superior semicircular canal, 2.33 mm (range 1.75-2.75); the tympanic segment between the anterior margin of the oval window niche and the geniculate ganglion, 3.58 mm (range 3.25-4); and from the tympanic segment adjacent to the anterior margin of the oval window niche to the labyrinthine segment adjacent to the superior semicircular canal, 3.48 mm (range 3-4.25). CONCLUSION: The key anatomical landmarks of the anterior supralabyrinthine air cell tract define a distinct triangular segment of bone, knowledge of which is helpful in surgical dissection.

Sternoclavicular joint swelling after surgery of the head and neck region: a case report and differential diagnostic review.

BACKGROUND: Very few published reports in the otolaryngologic literature discuss sternoclavicular joint swelling encountered in the postoperative setting. METHODS: The authors document a case of sternoclavicular joint swelling after medialization laryngoplasty. This report is supplemented with a review of the medical literature related to pertinent conditions affecting the sternoclavicular joint. CONCLUSIONS: In our patient, swelling was thought to be related to joint trauma experienced during surgery secondary to standard shoulder roll extension in a patient with preexisting postmenopausal arthritis. This case stands in contrast to the body of documented cases of postoperative sternoclavicular swelling in which the surgical procedure itself was responsible for such findings.

Postoperative management of pediatric tracheostomy: results of a nationwide survey.

OBJECTIVE: A survey was undertaken to document the postoperative care of pediatric tracheostomies by otolaryngologists. STUDY DESIGN: This study represents the results of a national survey of 564 otolaryngologists covering a broad scope of postoperative pediatric tracheostomy issues considered for patients younger than 2 years and patients older than 5 years. RESULTS: Of the surveys sent, 134 responses were received, portraying a certain standard management scheme that seems to be used by most respondents. CONCLUSIONS: Very little difference was seen in respondents' management of patients younger than 2 years of age as compared with those who are older than 5 years. Furthermore, agreement between actual practice and published recommendations seems to vary with some management issues. The results of this study provide a means by which otolaryngologists may familiarize themselves with national trends in the postoperative management of pediatric tracheostomies.