Pink-on-pink: hepatocellular carcinoma metastatic to oncocytic carcinoma of the thyroid.

Hepatocellular carcinoma typically metastasizes within the liver and may involve extrahepatic sites such as the lungs, adrenal glands, and bones at advanced stages. However, hepatocellular carcinoma metastasis to the thyroid is very uncommon and tumor-to-tumor metastasis from a hepatocellular cancer to a thyroid neoplasm is extremely rare. In this report, we present a case of a 70-year-old man with a hepatocellular carcinoma metastasizing to oncocytic thyroid carcinoma, emphasizing the importance of clinical history and of a multidisciplinary approach, as well as the usefulness of site-specific immunohistochemical markers, in diagnosing and managing cases of Rosai's metastasis, especially when donor and recipient neoplasms share similar histologic features.

Multi-Magnet Cochlear Implant Technology and Magnetic Resonance Imaging: The Safety Issue.

Despite the spread of novel-generation cochlear-implant (CI) magnetic systems, access to magnetic resonance imaging (MRI) for CI recipients is still limited due to safety concerns. The aim of this study is to assess and record the experiences of Hires Ultra 3D (Advanced Bionics) recipients who underwent an MRI examination. A multicentric European survey about this topic was conducted focusing on safety issues, and the results were compared with the current literature. We collected a total of 65 MRI scans performed in 9 otologic referral centers for a total of 47 Hires Ultra 3D recipients, including, for the first time, 2 children and 3 teenagers. Preventive measures were represented by scanning time and sedation for children. Head wrapping was used in eight cases, and six of the eight cases received local anesthesia, even if both measures were not needed. Only three patients complained of pain (3/65 examinations, 4.6%) due to the tight head bandage, and one of the three cases required MRI scan interruption. No other adverse events were reported. We believe that these results should encourage MRI execution in accordance with manufacturer recommendations for Ultra 3D recipients.

Implantable hearing devices in clinical practice. Systematic review and consensus statements.

Objective: Implantable hearing devices represent a modern and innovative solution for hearing restoration. Over the years, these high-tech devices have increasingly evolved but their use in clinical practice is not universally agreed in the scientific literature. Congresses, meetings, conferences, and consensus statements to achieve international agreement have been made. This work follows this line and aims to answer unsolved questions regarding examinations, selection criteria and surgery for implantable hearing devices. Materials and methods: A Consensus Working Group was established by the Italian Society of Otorhinolaryngology. A method group performed a systematic review for each single question to identify the current best evidence on the topic and to guide a multidisciplinary panel in developing the statements. Results: Twenty-nine consensus statements were approved by the Italian Society of Otorhinolaryngology. These were associated with 4 key area subtopics regarding pre-operative tests, otological, audiological and surgical indications. Conclusions: This consensus can be considered a further step forward to establish realistic guidelines on the debated topic of implantable hearing devices.

Blood Markers Predicting Clinically Occult Lymph Node Metastasis in Head and Neck Squamous Cell Carcinoma.

INTRODUCTION: The presence of cervical lymph node metastases is an unfavorable prognostic factor in head and neck squamous cell carcinoma (HNSCC) and a potential cause of treatment failure. Occult lymph node metastasis occurs in approximately 15-20% of HNSCC patients with a clinically negative neck (cN0), greatly impacting on their prognosis. The present study aimed to investigate the role of pre-treatment peripheral blood markers in predicting clinically occult cervical lymph node metastasis. METHODS: This multicenter, retrospective study was performed in a cohort of 472 patients diagnosed with cN0 HNSCC who underwent up-front surgery. Baseline neutrophil-to-lymphocyte ratio (NLR), platelet-to-lymphocyte ratio (PLR), lymphocyte-to-monocyte ratio (LMR), systemic inflammatory marker (SIM), and systemic immune-inflammation index (SII) were calculated from available blood parameters. RESULTS: Oro-hypopharyngeal and oral cancers, locally advanced stage, moderately (G2), and poorly (G3) differentiated grade were associated with an increased risk of pathological lymph node involvement. NLR, LMR, PLR, SIM, and SII were significantly associated at multivariable analysis. NLR >2.12 was the most reliable at predicting occult lymph node metastasis (OR = 5.22; 95% CI: 2.14-12.75). We describe a predictive score integrating cancer site, local stage, and NLR which is effective at predicting positive lymph node pathological status. CONCLUSIONS: The present study provides evidence that pre-treatment peripheral blood markers, in particular NLR, represent reliable predictors of clinically occult cervical lymph node metastasis in cN0 HNSCC. Therefore, the present study provides a novel useful predictive score for directing the elective management of the neck in patients with cN0 HNSCC.

Titanium Biohybrid Middle Ear Prostheses: A Preliminary In Vitro Study.

Ossiculoplasty is a surgical operation performed to restore auditory transmission through the reconstruction of the ossicular chain using prosthetics. Tissue bioengineering has assumed a pivotal role in implementing alternatives to conventional ossicular middle ear replacement prostheses, to overcome extrusion while preserving acoustic properties. This in vitro study aims to explore, for the first time in current literature, the feasibility of a biohybrid middle ear prosthesis, composed of titanium surrounded by a bone extracellular matrix as bio-coating. We have hereby studied the adhesion and proliferation of human adipose-derived mesenchymal stem cells (hASC) on titanium scaffolds in vitro. Moreover, we identified the osteogenic differentiation of hASC using an immunofluorescence assay to analyze osteoblasts' gene expression profiles (Alp, Runx2, Col1a1, Osx, and Bglap), and we counted the presence of collagen as a marker of hASC's ability to secrete an extracellular matrix. We utilized scanning electron microscopy to evaluate the presence of an extracellular matrix on the scaffolds. Our preliminary data demonstrated the titanium's ability to support human adipose-derived mesenchymal stem cell colonization, proliferation, and osteoblastic differentiation, in order to obtain a biohybrid device. Our experience seems encouraging; thus, we advocate for further in vivo research to corroborate our results regarding bone transplantation.

The Role of Bone-Anchored Hearing Devices and Remote Microphones in Children with Congenital Unilateral Hearing Loss.

Congenital unilateral hearing loss (UHL) represents a contemporary audiologic challenge. Children with UHL can struggle with understanding speech in noise, localizing sounds, developing language, and maintaining academic performance, leading to low self-esteem, anxiety, and decreased social support. Two specific conditions related to UHL in children are single-sided deafness (SSD) and unilateral auris atresia (UAA). This was a retrospective observational study on a group of children with UHL. The Simplified Italian Matrix Sentence Test was used for the assessment of speech reception threshold (SRT) in different conditions: speech and noise from the front (S0N0), speech at 45° from the side of the better ear and noise at 45° from the opposite side (SbNw), and vice versa (SwNb). Each test was conducted unaided, with a bone-anchored hearing device (BAHD), and with a remote microphone (RM) system. The use of a BAHD and RM led to an improvement in SRT in S0N0 and SwNb conditions. The SSD subgroup demonstrated significant benefits with both devices in SwNb, and the UAA subgroup from the use of BAHD in S0N0. In conclusion, the study underscores the potential benefits of both devices in enhancing speech perception for UHL children, providing insights into effective intervention strategies for these challenging cases.

Extrusion and Dislocation in Titanium Middle Ear Prostheses: A Literature Review.

Titanium middle ear (ME) prostheses are widely used in surgical practice due to their acoustic properties. However, they present a significant drawback shared by all synthetic materials currently in use for ME reconstruction: they can be rejected by the organism of the host. In this study, we aim to review the current literature on titanium partial ossicular replacement prostheses (PORPs) and total ossicular replacement prostheses (TORPs) extrusion and dislocation. Eighty articles were analysed after a full article review based on the inclusion and exclusion criteria. The most common indication for reconstruction was chronic otitis media with cholesteatoma. The average extrusion or dislocation rate was 5.2%, ranging from 0 to 35%. The average improvements in the air-bone gap were 12.1 dB (1.6 dB to 25.1 dB) and 13.8 (-0.5 dB to 22.7 dB) for the PORP and TORP groups, respectively. The data reported on this topic are highly variable, demonstrating that functional outcomes are difficult to predict in clinical practice. We believe that the current limitations could be overcome with technological developments, including bioengineering research focused on promoting prosthesis adaptation to the ME environment.

Current trends on subtotal petrosectomy with cochlear implantation in recalcitrant chronic middle ear disorders.

Objective: To establish the safety and effectiveness of subtotal petrosectomy with cochlear implantation in patients affected by chronic middle ear disorders to refractory to previous surgical treatments. Methods: A multicentre, retrospective study was conducted on patients affected by recalcitrant chronic middle ear disorders who underwent cochlear implantation in combination with subtotal petrosectomy. Patients' details were collected from databases of 11 Italian tertiary referral centres. Additionally, a review of the most updated literature was carried out. Results: 55 patients were included with a mean follow-up time of 44 months. Cholesteatoma was the most common middle ear recurrent pathology and 50.9% of patients had an open cavity. 80% of patients underwent a single stage surgery. One case of explantation for device failure was reported among the 7 patients with post-operative complications. Conclusions: Subtotal petrosectomy with cochlear implantation is a benchmark for management of patients with recalcitrant chronic middle ear disorders. A single stage procedure is the most recommended strategy. Optimal follow-up is still debated. Further studies are required to investigate the role of this surgery in paediatric patients.

The usefulness of the O-MAR algorithm in MRI skull base assessment to manage cochlear implant-related artifacts.

Objective: To assess artifact size and MRI visibility when applying the "Orthopedic-Metal Artifact Reduction" (O-MAR) algorithm for cochlear implant (CI) scanning. Methods: Two volunteers were submitted to 1.5 T MRI with an Ultra 3D CI receiver stimulator placed on their head. Four angular CI orientations were adopted: 90, 120, 135 and 160 degrees. Volunteers were scanned in each condition using T1w and T2w TSE sequences, as well as O-MAR sequences, in both axial and coronal planes. Quantitative comparisons were made of signal void and penumbra extent. Additionally, qualitative evaluations of global image quality, MRI readability with respect to 12 anatomical structures and visibility through the penumbra were undertaken. Results: After application of the O-MAR protocol, the radius of the signal void reduced from 50.76 mm to 45.43 mm and from 49.22 mm to 40.15 mm on T1w and T2w TSE axial sequences, respectively (p < 0.05). Qualitatively, sequences acquired with O-MAR produced better outcomes in terms of image quality and anatomical depiction. Despite the area of the penumbra being increased for the O-MAR protocol, visibility through penumbra was improved. Conclusions: Application of O-MAR may provide a complementary strategy to those already in use to obtain diagnostically useful MRI examinations in the presence of a CI, especially in case of skull base diseases requiring MRI monitoring.

The prognostic-nutritional index in HPV-negative head and neck squamous cell carcinoma treated with upfront surgery: a multi-institutional series.

Objectives: To evaluate the prognostic value of pre-treatment prognostic-nutritional index (PNI) in patients with HPV-negative head and neck squamous cell carcinoma (HNSCC). Methods: A multi-institutional retrospective series of HPV-negative, Stages II-IVB, HNSCCs treated with upfront surgery was evaluated. Correlation of pre-operative blood markers and PNI with 5-year overall (OS) and relapse-free (RFS) survival was tested using linear and restricted cubic spline models, as appropriate. The independent prognostic effect of patient-related features was assessed with multivariable models. Results: The analysis was conducted on 542 patients. PNI ≥ 49.6 (HR = 0.52; 95% CI, 0.37-0.74) and Neutrophil-to-Lymphocyte Ratio (NLR) > 4.2 (HR = 1.58; 95% CI, 1.06-2.35) confirmed to be independent prognosticators of OS, whereas only PNI ≥ 49.6 (HR = 0.44; 95% CI, 0.29-0.66) was independently associated with RFS. Among pre-operative blood parameters, only higher values of albuninaemia and lymphocyte count (> 1.08 x 103/microL), and undetectable basophile count (= 0 103/microL) were independently associated with better OS and RFS. Conclusions: PNI represents a reliable prognostic tool providing an independent measure of pre-operative immuno-metabolic performance. Its validity is supported by the independent prognostic role of albuminaemia and lymphocyte count, from which it is derived.

A Rare Presentation of Recalcitrant Oropharyngeal Stenosis in a 54-Year-Old Male Patient Following Transoral Robotic Surgery for Obstructive Sleep Apnea.

BACKGROUND Transoral robotic surgery (TORS) is an effective and safe option for obstructive sleep apnea syndrome (OSAS) patients with isolated retrolingual obstruction, as well as part of multilevel surgical approach in case of multilevel obstruction. Stenosis after TORS in OSAS patients is rarely described and no literature review has investigated this dramatic untoward event. CASE REPORT We report on a case of severe recalcitrant oropharyngeal stenosis after multilevel surgery with transoral robotic tongue base resection in an OSAS patient, leading to tracheotomy and gastrostomy dependence. Following the failure of numerous conservative therapeutic attempts, oropharyngeal patency was restored after extensive scar tissue removal through an open-neck approach, followed by a pharyngeal reconstruction with radial forearm free flap (RFFF). CONCLUSIONS Recalcitrant oropharyngeal stenosis is a dramatic complication that must be considered in OSAS patients submitted to TORS in a multilevel strategy and that is rarely described in the literature. A thorough review of the existing literature is presented to assess which factors are involved and the therapeutic strategies invoked in this scenario. The adoption of resection tools suited for robot-assisted surgery and the staging of TORS in case of multilevel surgery could decrease the risk of extensive scar formation. To date there is still no broad consensus on which therapeutic choice is the best for recalcitrant oropharyngeal stenosis. When minimally invasive treatments fail, a wide scar resection with a RFFF oropharyngeal reconstruction could be considered as a valuable option to restore the upper aerodigestive tract patency.

Deep learning and machine learning-based voice analysis for the detection of COVID-19: A proposal and comparison of architectures.

Alongside the currently used nasal swab testing, the COVID-19 pandemic situation would gain noticeable advantages from low-cost tests that are available at any-time, anywhere, at a large-scale, and with real time answers. A novel approach for COVID-19 assessment is adopted here, discriminating negative subjects versus positive or recovered subjects. The scope is to identify potential discriminating features, highlight mid and short-term effects of COVID on the voice and compare two custom algorithms. A pool of 310 subjects took part in the study; recordings were collected in a low-noise, controlled setting employing three different vocal tasks. Binary classifications followed, using two different custom algorithms. The first was based on the coupling of boosting and bagging, with an AdaBoost classifier using Random Forest learners. A feature selection process was employed for the training, identifying a subset of features acting as clinically relevant biomarkers. The other approach was centered on two custom CNN architectures applied to mel-Spectrograms, with a custom knowledge-based data augmentation. Performances, evaluated on an independent test set, were comparable: Adaboost and CNN differentiated COVID-19 positive from negative with accuracies of 100% and 95% respectively, and recovered from negative individuals with accuracies of 86.1% and 75% respectively. This study highlights the possibility to identify COVID-19 positive subjects, foreseeing a tool for on-site screening, while also considering recovered subjects and the effects of COVID-19 on the voice. The two proposed novel architectures allow for the identification of biomarkers and demonstrate the ongoing relevance of traditional ML versus deep learning in speech analysis.

Customized Cochlear Implant Positioning in a Patient With a Low- Grade Glioma: Towards the Best MRI Artifact Management.

OBJECTIVE: To report the personalized decision-making pro- cess adopted for a cochlear implant (CI) candidate requiring magnetic resonance imaging (MRI) brain surveillance. STUDY DESIGN: Clinical capsule report. SETTING: Tertiary academic referral center. PATIENT: A 23-year-old man affected by posttraumatic bilat- eral profound hearing loss, already in radiological follow-up for a suspected small left cuneal low-grade glioma. INTERVENTIONS: A multidisciplinary approach involving preoperative MRI simulations and 3D printed (3DP) models aiming to adapt the CI position to facilitate MRI brain lesion visibility. MAIN OUTCOME MEASURES: MRI visibility and surgical approach. RESULTS: Preoperative MRI scans with the placement of an Ultra 3D CI were performed simulating different implant location to assess the brain lesion visibility in MRI. CI was positioned 9 cm away from the external auditory canal with an angle of 90 degrees. To assess the technical feasibility of the surgical procedure, a patient-specific 3DP head model was produced preoperatively. The postoperative course was uneventful, the patient showed a significant benefit from CI, and the brain lesion was highly visible at the MRI follow-up. CONCLUSIONS: The employment of strategies aimed at improving the MRI quality in CI recipients still represents a topic requiring attention. Thanks to multidisciplinary team collaboration, in our case, the CI position was successfully determined to allow unhindered MRI visibility of a specific intracranial structure.

The role of cochlear implant positioning on MR imaging quality: a preclinical in vivo study with a novel implant magnet system.

PURPOSES: To investigate the effects for Ultra 3D cochlear implant (CI) positioning on MR imaging quality, looking at a comprehensive description of intracranial structures in cases of unilateral and bilateral CI placement. METHODS: Four CI angular positions (90°, 120°, 135° and 160°) at 9 cm distance from the outer-ear canal were explored. The 1.5 T MRI assessment included our institutional protocol for the investigation of brain pathologies without gadolinium application. Three investigators (two experienced neuroradiologists and one experienced otoneurosurgeon) independently evaluated the MR findings. A 4-point scale was adopted to describe 14 intracranial structures and to determine which CI positioning allowed the best image quality score and how bilateral CI placement modified MRI scan visibility. RESULTS: A high positive correlation was found between the three blinded observers. Structures situated contralateral from the CI showed high-quality values in all four placements. Structures situated ipsilaterally provided results suitable for diagnostic purposes for at least one position. At 90°, artifacts mainly involved brain structures located cranially and anteriorly (e.g., temporal lobe); on the contrary, at 160°, artifacts mostly influenced the posterior fossa structures (e.g., occipital lobe). For the bilateral CI condition, MR imaging examination revealed additional artifacts involving all structures located close to either CI, where there was a signal void/distortion area. CONCLUSIONS: Suitable unilateral CI positioning can allow the visualization of intracranial structures with sufficient visibility for diagnostic purposes. Bilateral CI positioning significantly deteriorates the anatomical visibility. CI positioning might play a crucial role for patients who need post-operative MRI surveillance.

Bulging of the Oval Window in Common Cavity Deformity: A Possible Predictor of Meningitis.

OBJECTIVE: To investigate the prevalence-rate of oval window bulging in the common cavity and its association with bacterial meningitis. PATIENTS: CT and clinical files of 29 children with preliminary diagnosis of common cavity deformity were collected from 13 Italian centers. INTERVENTION: A retrospective case review study was conducted with a centralized evaluation of the temporal bone CT imaging was performed at Azienda Ospedale - Università Padova, Padova, Italy. MAIN OUTCOME MEASURE: Diagnosis of common cavity was reviewed; in addition, a fluid protrusion into the middle-ear cavity through the oval window at CT imaging was considered as oval window bulging. Its association with the history of bacterial meningitis was investigated. RESULTS: Common cavity deformity was confirmed in 14/29 children (mean-age 11.4 ±â€Š3.8; age-range 5-20; nine females) referred with this diagnosis. In 7/14 patients, the common cavity deformity was bilateral (i.e., 21 common cavities). Oval window bulging was found in 3/19 common cavities (concomitant middle-ear effusive otitis hampered the evaluation in two cases), while the internal acoustic meatus fundus was defective in 10/21 cases. History of bacterial meningitis was found in three children (21%) and two of them had oval window bulging at CT. In the case unrelated to oval window bulging, meningitis occurred late at the age of 12 during acute otitis contralateral to common cavity deformity (ipsilaterally to incomplete partition type 1). CONCLUSION: Patients harboring common cavity deformity have a high risk of meningitis in their first years of life. Oval window bulging seems to be associated with a higher risk of meningitis. This information might be important for appropriate surgical planning.

Prognostic value of H-index in patients surgically treated for squamous cell carcinoma of the larynx.

OBJECTIVE: Recently, a novel host-related index, the Host-index (H-index), including both inflammatory and nutritional markers, has been described and observed to stratify prognosis in patients with squamous cell carcinoma (SCC) of the oral cavity more accurately than other host-related indexes This study aimed to investigate the prognostic performance of the H-index using pretreatment blood tests in patients receiving up-front surgery for SCC of the larynx. METHODS: This retrospective observational study included a multicenter series of consecutive patients with SCC of the larynx diagnosed between 1 January 2009 and 31 July 2018, whose pretreatment blood tests were available and included the parameters necessary for the calculation of neutrophil to lymphocyte ratio (NLR) and the H-index. Their association with disease-free survival (DFS) and overall survival (OS) was measured. RESULTS: A total of 231 patients were eligible for the present analysis (median [range] age, 68 [37-96] years; 191 [82.7%] men). The median follow-up was 73 months. In multivariable Cox proportional hazards regression models, increasing age (adjusted hazard ratio [aHR], 1.07 per year; 95% CI, 1.04-1.09), advanced pT stage (aHR = 1.71 95% CI: 1.07-2.71), and having close or positive surgical margins (aHR = 2.01; 95% CI: 1.21-3.33) were significantly associated with poor OS. Among blood parameters, a higher neutrophil count was a strong predictor of both worse DFS (aHR for recurrence/death = 2.34; 95% CI: 1.24-4.40) and OS (aHR for death = 2.67; 95% CI: 1.51-4.71). Among inflammatory blood indexes, while NLR was not significantly associated with DFS or OS, patients with H-index ≥8.37 showed a higher aHR for both recurrence/death (2.82; 95% CI: 1.65-4.79) and death (2.22; 95% CI: 1.26-3.89). CONCLUSION: In conclusion, the present study confirms the prognostic value of pretreatment H-index, an easily measurable inflammatory and nutritional index, in patients with SCC of the larynx. LEVEL OF EVIDENCE: III.

The risk of recurrence in surgically treated head and neck squamous cell carcinomas: a conditional probability approach.

BACKGROUND: Over 50% of patients with head-and-neck squamous cell carcinoma (HNSCC) experience locoregional recurrence, which is associated with poor outcome. In the course of follow-up for patients surviving primary surgery for HNSCC, one might ask: What is the probability of recurrence in one year considering that the cancer has not yet recurred to date? MATERIALS AND METHODS: To answer this question, 979 patients surgically treated for HNSCC (i.e. cancer of the oral cavity, oropharynx, hypopharynx or larynx) between March 2004 and June 2018 were enrolled in a multicenter retrospective cohort study, followed up for death and recurrence over a 5 year period. The conditional probability of recurrence in 12 months - i.e. the probability of recurrence in the next 12 months given that, to date, the patient has not recurred - was derived from the cumulative incidence function (Aalen-Johansen method). RESULTS: Overall, the probability of recurrence was the highest during the first (17.3%) and the second years (9.6%) after surgery, declining thereafter to less than 5.0% a year thereafter. The probability of recurrence was significantly higher for stage III-IV HNSCCs than for stage I-II HNSCCs in the first year after surgery (20.4% versus 10.0%; p < 0.01), but not thereafter. This difference was most pronounced for oral cavity cancers. No significant differences were observed across different tumor sites. CONCLUSION: This dynamic evaluation of recurrence risk in patients surgically treated for HNSCC provides helpful and clinically meaningful information, which can be useful to patients in planning their future life, and to clinicians in tailoring post-treatment surveillance according to a more personalized risk stratification.

Gangliformis Intumescentia and Beyond: Antonio Scarpa and His Core Contribution to Neuroanatomy, Neurosurgery, and Otoneurosurgery.

Nearly 250 years ago, Antonio Scarpa became a professor of anatomy and surgery only 2 years after he graduated from the University of Padua. The young lecturer soon became one of the most renowned anatomists in Italy and a director of the Faculty of Medicine at the University of Pavia. He worked in the fields of general surgery and ophthalmology. Several anatomic structures have been named after him, mainly Scarpa fascia and Scarpa triangle. His interest in neuroanatomy was ardent, despite being occasionally neglected. Scarpa's contributions to the fields of neurosciences have been significant. He was the first to describe the round window and the secondary tympanic membrane, and he eventually focused on the auditory and olfactory organs. Notably, the vestibular ganglion is now known as Scarpa ganglion. Scarpa's magnum opus was the book Tabulae Neurologicae, in which he described the path of several cranial nerves including the vagus nerve and innervation of the heart. Since his death in 1832, Scarpa's head has been preserved at the University History Museum of the University of Pavia. In this historical vignette, we aim to describe Antonio Scarpa's troubled life and brilliant career, focusing on his core contributions to neuroanatomy, neurosurgery, and otoneurosurgery.

Retrosigmoidal placement of an active transcutaneous bone conduction implant: surgical and audiological perspectives in a multicentre study.

INTRODUCTION: The retrosigmoidal (RS) placement of the Bonebridge system (BB) has been advocated for cases of unfavourable anatomical or clinical conditions which contraindicate transmastoid-presigmoidal positioning. However, these disadvantageous conditions, combined with the considerable dimensions of the implant, may represent a challenge, especially for surgeons with no skull base experience. Moreover, the literature reports only limited experience concerning RS implantation of the BB system. METHODS: A multicentre, retrospective study was conducted to analyse the surgical and functional outcomes of a wide population of patients undergoing RS placement of the BB system by means of a surgical technique specifically developed to overcome the intraoperative issues related to this surgery. Twenty patients with conductive or mixed hearing loss and single sided deafness were submitted to RS implantation of the BB system. RESULTS: Audiological assessment concerning the measurement of the functional and effective gain by pure-tone audiometry (28 dB HL and -12.25 dB HL, respectively) and speech audiometry (24.7 dB HL and -21 dB HL, respectively) was conducted. A high overall subjective improvement of quality of life was recorded with the Glasgow Benefit Inventory questionnaire. No major complications, such as device extrusions or other conditions requiring revision surgery, were reported during the follow-up period (median: 42 months). CONCLUSIONS: In our study, which has one of the largest cohort of patients reported in the literature, RS placement of the BB system was safe and effective. Our functional results showed comparable hearing outcomes with presigmoidal placement. The effective gain, rarely investigated in this field, may be the object of further research to improve our understanding of bone conduction mechanisms exploited by bone conduction hearing implants.