Accuracy and feasibility of a dedicated image guidance solution for endoscopic lateral skull base surgery.

OBJECTIVE We aimed to design, build and validate a surgical navigation system which fulfills the accuracy requirements for surgical procedures on the ear and the lateral skull base, and which integrates with the endoscopic workflow and operating room setup. MATERIALS AND METHODS The navigation system consists of portable tablet computer (iPad Pro, Apple Computer, USA) and an optical tracking system (Cambar B1, Axios3D, Germany), both connected via a wireless Bluetooth link and attached directly to the OR table. Active optical tracking references are rigidly fixed to both the patient and surgical tools. Software to support image import, registration and 2D/3D visualization has been developed. Two models were used for targeting accuracy assessment: a technical phantom model and an ex vivo temporal bone model. Additionally, workflow integration and usability of the navigation system during endoscopic lateral skull base procedures was investigated in ex vivo experiments on 12 sides of cadaver head specimens. RESULTS The accuracy experiments revealed a target registration error in the technical phantom model of 0.20 ± 0.10 mm (n = 36) and during the ex vivo assessment of 0.28 ± 0.10 mm (n = 21). Navigation was successfully carried out in n = 36 procedures (infracochlear, suprageniculate and transpromontorial approach), with navigated instruments usable without interference with the endoscope. The system aided in the successful and accurate identification of vital anatomical structures. CONCLUSIONS Useful surgical navigation is, to a large extent, a result of sufficiently accurate tracking technology. We have demonstrated sufficient accuracy and a potentially suitable integration for surgical application within endoscopic lateral skull base procedures

Teaching Middle Ear Anatomy and Basic Ear Surgery Skills: A Qualitative Study Comparing Endoscopic and Microscopic Techniques.

OBJECTIVE Endoscopic ear surgery is gaining popularity as a minimally invasive surgical technique for middle ear diseases. Its ongoing implementation into clinical routine has consequences regarding teaching of middle ear anatomy and surgery. To improve undergraduate and postgraduate training, we investigated the perception of and preference for endoscopy as compared with microscopy at different educational levels. STUDY DESIGN Qualitative study based on a thematic analysis approach. SETTING Tertiary academic medical center. METHODS After a standardized curriculum was run on endoscopic and microscopic anatomy and surgical skills education, 5 focus groups were held. The interviews were conducted, video recorded, transcribed, and analyzed. Analysis of the data gave rise to 11 themes showing the participants' perceptions and preferences. RESULTS Five medical students, 11 otorhinolaryngology residents, and 3 staff members participated in this qualitative study. For anatomy teaching, there was a clear preference for the endoscopic technique. The main advantages were the enhanced overview and perception of the anatomic details provided through endoscopy. For skills acquisition, the perceived advantages of the techniques were the same view of the surgical field for endoscopy and the 2-handed surgical technique for microscopy. However, there was no clear preference between the techniques for skills acquisition. CONCLUSION The endoscopic technique was generally judged more beneficial for teaching anatomy, especially due to the greater visualization of the complex middle ear anatomy. Given that both techniques will remain important to future surgeons, the relative unique benefits of each must be considered when designing and optimizing curricula for otologic education

Long-term efficacy assessment of current treatment options for epistaxis in HHT.

PURPOSE Hereditary hemorrhagic telangiectasia (HHT) is a vascular disorder that presents with recurrent, intractable epistaxis. The aim of this study was to retrospectively analyze the efficacy of various treatment options for epistaxis in patients with HHT, over a period of 18 years, and to correlate these findings with available evidence in the literature. METHODS Records of patients with HHT, treated for epistaxis between 2000 and 2018 were analyzed. Treatment procedures carried out and their efficacy were extracted and analyzed. RESULTS Forty-three records were evaluated. All patients were given nasal humidifying ointments, 93% required acute treatment with bipolar electrocautery, and 60% underwent atraumatic nasal packing. Recurrent cases were treated medically with tranexamic acid (26%), oestrogen (19%), and bevacizumab (2%). Laser photocoagulation was done in selected cases (40%) and if unsuccessful, septal dermoplasty was performed (2.3%). Endovascular embolization was reserved for life-threatening emergencies (7%). CONCLUSION Epistaxis in HHT is not curable, but can be managed by employing a comprehensive stepwise approach. An algorithm for effective and comprehensive management has been presented

Relevance of Intraparotid Metastases in Head and Neck Skin Squamous Cell Carcinoma.

OBJECTIVES Parotid lymph node metastases are common in head and neck cutaneous squamous cell carcinoma (cSCCHN). Here we evaluate the diagnostic, prognostic, and therapeutic implications of intraglandular lymph node (IGLN) metastases in cSCCHN. STUDY DESIGN Retrospective study in a tertiary referral university cancer institute. METHODS We included patients with cSCCHN who underwent parotidectomy and neck dissection (ND), with or without synchronous resection of the skin primary, between January 1999 and January 2018. The characteristics of cSCCHN with or without IGLN involvement were compared. RESULTS Altogether, 68 patients were included. Of the 29 (42.6%) patients classified as cN0, eight were upstaged pN+ and had concomitant IGLN involvement. Of 21 patients with pN0 disease, IGLN metastases were absent in only three cases, resulting in a specificity and sensitivity of parotid metastases to diagnose occult nodal neck metastases of 14.29% and 100%, respectively. The positive and negative predictive values were 14.29% and 100%, respectively. Univariate analyses only displayed a significantly higher rate of moderately and poorly differentiated primaries in patients with IGLN metastases (P = .015). Only advanced T-stages were significantly associated with neck recurrences. CONCLUSION IGLN status in advanced cSCCHN is potentially predictive for occul nodal neck metastases. Our results suggest that ND in patients with histopathologically negative IGLNs and clinically negative neck lymph nodes may not be necessary given the high negative predictive value of IGLN status in this group of patients. Therefore, accurate diagnostic evaluation of IGLN involvement is mandatory. LEVEL OF EVIDENCE 4 Laryngoscope, 2020

Taste Alteration in External Auditory Canal Cholesteatoma: Indicator of Impending N VII Affection.

INTRODUCTION External auditory canal cholesteatoma (EACC) is a rare disease, with an estimated incidence of approximately 1:1,000 adult and 1.6:1,000 pediatric otologic patients. Systematic studies of chronic ear disease and taste alteration prior to surgery are rare; in fact, there are no such studies for EACCs. Therefore, we describe chorda tympani nerve (CTN) dysfunction and the related clinical consequences in EACC patients. METHODS/STUDY DESIGN Between 1992 and 2021, we retrospectively analyzed the symptoms, signs, and radiological and intraoperative descriptions of CTN involvement in 73 patients. Liquid taste tests and, since 2009, Taste StripsTM as well as an olfactory screening test (Smell DiskettesTM) have been performed for all symptomatic patients and, when feasible, all other EACC patients. RESULTS Ten of 73 patients complained subjectively of dysfunction, and 8 showed abnormal taste test results. Four patients complained of olfactory dysfunction (3 cases with pathological taste tests). Gustatory dysfunction was most frequent in radiogenic EACC cases (n = 4), followed by postoperative EACC (n = 3). Two postoperative patients were asymptomatic despite abnormal test results. Rarely, patients with idiopathic (n = 2) and posttraumatic (n = 1) EACC showed acute taste dysfunction that was confirmed in each with abnormal test results. DISCUSSION/CONCLUSION CTN dysfunction often developed asymptomatically in chronic ears, except for idiopathic and posttraumatic EACCs under previous healthy middle ear conditions. Taste disturbance is not a cardinal symptom of EACC, but objective testing suggests that up to one out of 10 EACC patients with advanced disease may experience regional gustatory dysfunction prior to surgery. Especially in context of a new and acute presentation, regional taste dysfunction may alert the clinician of potential progressive EACC invasion and danger to the facial nerve

Recurrent parotid gland carcinoma: how effective is salvage surgery?

OBJECTIVE Recurrent parotid gland carcinomas (PGCs) are poorly characterized and studies focusing on this topic are rare due to their low incidence. The goal of this study is to analyze the therapeutic strategies, prognostic factors, and oncological outcomes of a series of patients with recurrent PGCs. PATIENTS AND METHODS Retrospective chart review (1997-2012) of patients with recurrent PGCs was initially treated with curative intent. RESULTS We identified 20 patients with recurrent PGCs. Eleven patients presented isolated local, regional, or distant metastases, while the rest had recurrences in multiple sites. Recurrent tumors tended to present more advanced T-stage (p = 0.01) and overall stage (p < 0.001), but not N-stage (p = 0.74) when compared to the initial tumors. Half the patients (50%) had distant metastases at the moment of recurrence diagnosis, and another three developed them after attempted salvage surgery. Only 8/20 patients with isolated local or regional recurrences were surgically salvaged with extended revision parotidectomy and neck dissection, respectively. The remaining 12 patients were managed on palliative basis. Overall survival (31.70 months vs. 20.73 months) and progression-free survival (28.70 months vs. 13.61 months) were not significantly different in patients managed surgically vs. palliatively. CONCLUSION Recurrent PGCs are aggressive neoplasms with a high rate of distant metastases. Surgical salvage can be considered in patients with limited local and/or regional recurrences. The alternative to surgical salvage is palliative management with different chemotherapeutic regimens. Survival does not differ between the two strategies in the present series