Capillary Blood Gas Measurement as a Novel Means of Assessing Flap Perfusion in Free Tissue Transfer

CAPILLARY BLOOD GAS MEASUREMENT AS A NOVEL MEANS OF ASSESSING FLAP PERFUSION IN FREE TISSUE TRANSFER. Aaron K. Remenschneider and Douglas A. Ross (Sponsored by Dr. Clarence Sasaki). Section of Otolaryngology, Department of Surgery, Yale University, School of Medicine, New Haven, CT. To demonstrate that in comparison to implantable O2 microelectrodes, Capillary Blood Gas measurements represent a reliable, accessible and easy method of identifying failing free flaps, and furthermore, to assess post-operative free-flap monitoring techniques nation-wide, determining the openness of surgeons to new surveillance modalities. Groin fasciocutaneous flaps were elevated in 10 rats and following arterial or venous occlusion, oxygen microelectrode measurements (pO2 and flow) and Capillary Blood Gas measurements (pO2, pCO2, pH, HCO3) were obtained at 0, 10 and 20 minutes. A nine question, Internet based survey on post-operative flap surveillance techniques was sent to the personal email addresses of 238 microvascular surgeons from around the country. Response data were collected and analyzed utilizing an online resource. Measurements with capillary blood gas paralleled measurements with O2 microelectrodes. Average capillary blood gas pO2 fell from 42.72 mm Hg at 10 minutes and then to 28.67 mm Hg at 20 minutes. Average pH fell from 7.38 to 7.33 at 10 minutes and to 7.30 at 20 minutes. Results were statistically significant with both the paired Students t test and the Wilcoxon signed rank test. 75% of survey respondents indicated that clinical assessment was more important than available adjunctive tests in the decision to re-explore the vascular pedicle in a threatened free flap and 56% listed pinprick with flap bleeding as an important marker of flap health in their practice. 90% of respondents indicated they are open to new quantitative monitoring techniques. While providing users the ability to simultaneously monitor accepted modalities of flap surveillance, pH and pO2, the capillary blood gas is a reliable and reproducible marker of flap tissue health. Given that no single monitoring modality enjoys a clear preference among microvascular surgeons and that more than half of these surgeons already utilize pinprick assessment of the flap, this study demonstrates that the capillary blood gas may be well positioned for further study in humans

Medialized Total Ossicular Replacement Prosthesis

Vestibular complaints secondary to a deeply medialized ossicular prosthesis have been documented following stapedotomy1 but infrequently reported following total ossicular replacement prosthesis (TORP) placement. Lateral TORP displacement through the tympanic membrane (TM) occurs in 5% to 9% of cases2; however, medial displacement, with violation of the footplate, is rare and has only been reported following canal wall down mastoidectomy.3 For the below case, institutional review board approval was obtained from the University of Massachusetts Medical School Human Subjects Committee

Metastatic Renal Cell Carcinoma to the Sinonasal Cavity: A Case Series

Objectives: To describe the presentation, work-up, and management of patients with metastatic renal cell carcinoma (RCC) to the sinonasal cavity and skull base, and to describe our current treatment algorithm of endoscopic surgical resection followed by radiation therapy. Design: Retrospective review of two recent cases from our institution over a 1-year period, with a relevant review of the literature. Setting: A large regional tertiary care facility. Participants: Consecutive cases of RCC with metastases to the sinonasal cavity presenting to our institution. Main Outcome Measures: Preoperative and postoperative sinonasal outcome test (SNOT)-22 scores, duration of hospital stay, complications, and local disease control Results: Patients in this series underwent preoperative embolization followed by endoscopic resection without complication. Postoperatively they were treated with radiation therapy. They experienced improvement in their SNOT-22 scores and are currently free of local disease. Conclusion: Metastatic RCC to the sinonasal cavity can be safely treated with preoperative embolization followed by endoscopic surgical resection and radiation therapy, which can result in improvement in sinonasal quality of life and is a potential adjunct for local control of disease

Delayed Endovascular Coil Extrusion following Internal Carotid Artery Embolization

Internal carotid artery injury is a rare and devastating complication of endoscopic sinus and skull base surgery that has an associated mortality rate of 15%. This case describes a patient who developed massive epistaxis following routine sinus surgery and was eventually diagnosed with a pseudoaneurysm of the cavernous internal carotid artery. Endovascular coiling and Onyx (Covidien, Irvine, California, United States) liquid embolization were ultimately used to completely occlude the internal carotid artery with resolution of bleeding; however, the patient had an unexpected late complication of coil extrusion through the pseudoaneurysm sac into the sphenoid sinus and nasal cavity. The endoscopic skull base team safely excised the coils endoscopically without recurrent bleeding. We describe the multidisciplinary operative management of this case of endovascular coil extrusion to increase awareness of this potentially life-threatening complication

Does stapedotomy improve high frequency conductive hearing?

Objectives: Stapedotomy is performed to address conductive hearing deficits. While hearing thresholds reliably improve at low frequencies (LF), conductive outcomes at high frequencies (HF) are less reliable and have not been well described. Herein, we evaluate post-operative HF air-bone gap (ABG) changes and measure HF air conduction (AC) thresholds changes as a function of frequency. Methods: Retrospective review of patients who underwent primary stapedotomy with incus wire piston prosthesis between January 2016 and May 2020. Pre- and postoperative audiograms were evaluated. LF ABG was calculated as the mean ABG of thresholds at 250, 500, and 1000 Hz. HF ABG was calculated at 4 kHz. Results: Forty-six cases met criteria. Mean age at surgery was 54.0 +/- 11.7 years. The LF mean preoperative ABG was 36.9 +/- 11.0 dB and postoperatively this significantly reduced to 9.35 +/- 6.76 dB, (P \u3c .001). The HF mean preoperative ABG was 31.1 +/- 14.4 dB and postoperatively, this also significantly reduced to 14.5 +/- 12.3 dB, (P \u3c .001). The magnitude of LF ABG closure was over 1.5 times the magnitude of HF ABG closure (P \u3c .001). The gain in AC decreased with increasing frequency (P \u3c .001). Conclusion: Hearing improvement following stapedotomy is greater at low than high frequencies. Postoperative air bone gaps persist at 4 kHz. Further biomechanical and histopathologic work is necessary to localize postoperative high frequency conductive hearing deficits and improve stapedotomy hearing outcomes. Level of Evidence: 4, retrospective study

Cycling exercise classes may be bad for your (hearing) health

OBJECTIVES/HYPOTHESIS: 1) Determine feasibility of smartphone-based mobile technology to measure noise exposure; and 2) measure noise exposure in exercise spin classes. STUDY DESIGN: Observational Study. METHODS: The SoundMeter Pro app (Faber Acoustical, Salt Lake City, UT) was installed and calibrated on iPhone and iPod devices in an audiology chamber using an external sound level meter to within 2 dBA of accuracy. Recording devices were placed in the bike cupholders of participants attending spin classes in Boston, Massachusetts (n = 17) and used to measure sound level (A-weighted) and noise dosimetry during exercise according to National Institute for Occupational Safety and Health (NIOSH) guidelines. RESULTS: The average length of exposure was 48.9 ± 1.2 (standard error of the mean) minutes per class. Maximum sound recorded among 17 random classes was 116.7 dBA, which was below the NIOSH instantaneous exposure guideline of 140 dBA. An average of 31.6 ± 3.8 minutes were spent at >100 dBA. This exceeds NIOSH recommendations of 15 minutes of exposure or less at 100 dBA per day. Average noise exposure for one 45-minute class was 8.95 ± 1.2 times the recommended noise exposure dose for an 8-hour workday. CONCLUSIONS: Preliminary data shows that randomly sampled cycling classes may have high noise levels with a potential for noise-induced hearing loss. Mobile dosimetry technology may enable users to self-monitor risk to their hearing and actively engage in noise protection measures. LEVEL OF EVIDENCE: NA Laryngoscope, 127:1873-1877, 2017.Accepted manuscrip

Skull base erosion and associated complications in sphenoid sinus fungal balls

Background: Sphenoid sinus fungal balls (SSFB) are rare entities that can result in serious orbital and intracranial complications. There are few published reports of complications that result from SSFB. Objective: To review the incidence of skull base erosion and orbital or intracranial complications in patients who present with SSFB. Methods: A retrospective review was performed of all the patients with SSFB who were treated at the Massachusetts Eye and Ear Infirmary from 2006 to 2014. Presenting clinical data, radiology, operative reports, pathology, and postoperative course were reviewed. Results: Forty-three patients with SSFB were identified. Demographic data were compared between patients with (39.5%) and those without (61.5%) skull base erosion. Two patients underwent emergent surgery for acute complications of SSFB (one patient with blindness, one patient who had a seizure). Both patients with acute complications had evidence of skull base erosion, whereas no patients with an intact skull base developed an orbital or intracranial complication (p = 0.15). All the patients were surgically managed via an endoscopic approach. Conclusion: SSFBs are rare but may cause significant skull base erosion and potentially severe orbital and intracranial complications if not treated appropriately. Endoscopic sphenoidotomy is effective in treating SSFB and should be performed emergently in patients who presented with associated complications

International Survey of Operative Practices for Otologists and Neurotologists During the COVID-19 Crisis

OBJECTIVE: To investigate the influence of the COVID-19 pandemic on operative practices of otology and neurotology providers internationally. STUDY DESIGN: Cross-sectional survey. METHODS: A 78-question survey was distributed to otologists and neurotologists between May 12, 2020 and June 8, 2020 to assess the impact of the pandemic on surgical practices. Sections within the survey delineated time periods: prior to the crisis, onset of the crisis, during the crisis, postcrisis transition. RESULTS: Of 396 survey respondents, 284 participants from 38 countries met inclusion criteria. Respondents were 16.9% female and 82.4% male, with a most common age range of 40 to 49 years (36.3%). 69.8% of participants had been in practice for over 10 years and most respondents worked in an academic medical center (79.2%). The average operative weekly caseload was 5.3 (SD 3.9) per surgeon prior to the crisis, 0.7 (SD 1.2) during the COVID-19 crisis, and 3.5 (SD 3.3) for those who had begun a postcrisis transition at the time of survey administration (p \u3c 0.001). 71.5% of providers did not perform an elective otologic or neurotologic operative procedure during the initial crisis period. 49.8% reported modifying their surgical technique due to the COVID-19 pandemic. Use of powered air-purifying respirators and filtering facepiece 2 or 3 (FFP2/FFP3) respirators were in minimal supply for 66.9% and 62.3% of respondents, respectively. CONCLUSION: The COVID-19 pandemic impacted the otology and neurotology community globally, resulting in significant changes in operative volume and case selection. Modification of surgical technique and shortages of personal protective equipment were frequently reported

Plasmacytoma of the Clivus Presenting as Bilateral Sixth Nerve Palsy

Background and Importance Plasmacytomas are monoclonal proliferations of plasma cells that may arise within soft tissue or bone. The skull base is a rare site for plasmacytomas to occur, and few cases have been reported in the literature. When present in the skull base, plasmacytomas may result in cranial neuropathies and often progress to multiple myeloma more rapidly than other intracranial or skeletal plasmacytomas. Clinical Presentation A 69-year-old man presented with a primary complaint of diplopia and an examination consistent with bilateral abducens nerve palsy. No other deficits were noted. Magnetic resonance imaging of the skull base demonstrated a large T1 isointense moderately enhancing lesion centered within the clivus. Endoscopic biopsy of the mass revealed sheets and aggregates of mature monoclonal plasma cells. The patient's initial systemic work-up revealed that this was a solitary lesion, and he was treated with radiation therapy to the skull base with a durable local effect at 18-month follow-up. Unfortunately he progressed to multiple myeloma with peripheral osteolytic lesions but has been stabilized on chemotherapeutics. Conclusion: The clivus is an unusual site for intracranial plasmacytomas, and enhancing lesions must be differentiated from chordoma. Characteristic findings on histopathology include an immunoglobulin light-chain restricted clonal proliferation of plasma cells. Treatment is most commonly radiotherapy with surgery reserved for biopsy and palliation. Clinicians should be aware of the increased risk of progression to multiple myeloma in skull base plasmacytomas

Ex vivo transtympanic permeation of the liposome encapsulated S. pneumoniae endolysin MSlys

An increase in bacterial resistance to systemic antibiotics has sparked interest into alternative antimicrobial compounds as well as methods for effective local, non-invasive drug delivery. Topical treatments, however, may be hindered by the presence of biological barriers, such as the tympanic membrane in the case of otitis media. Herein, the transtympanic permeation ability of liposomes loaded with the pneumococcal endolysin MSlys and of free MSlys was evaluated ex vivo. MSlys loaded in PEGylated liposomes showed an increased permeation across human tympanic membranes, as compared to its free form, being able to reduce the pneumococcal cell load after 2 h of permeation. However, antipneumococcal activity was no longer detected after 4 h of permeation and hydrolysis of the endolysin was observed after an extended incubation time ( 48 h). This work provides a first assessment of a successful, non-invasive delivery method for endolysins across an intact tympanic membrane. Findings have implications for non-systemic, local treatment of otitis media.This study was partially supported by the Portuguese Foundation for Science and Technology (FCT) under the scope of the strategic funding of UID/BIO/04469/2020 unit. MDS acknowledges support from the FCT doctoral fellowship, reference SFRH/BD/128825/2017 and COVID/BD/152363/2022. SS acknowledges funding by FCT, through the individual scientific employment program contract (2020.03171.CEECIND). AKR acknowledges funding to support this project from the Wyss Institute for Biologically Inspired Engineering at Harvard University and from NIH NIDCD K08-DC018575info:eu-repo/semantics/publishedVersio