Claire E. Iseli

Functional outcomes of fibula and osteocutaneous forearm free flap reconstruction for segmental mandibular defects.

To demonstrate that the osteocutaneous radial forearm free flap provides equivalent functional outcomes and improved morbidity compared to the fibular free flap in mandibular reconstruction.

Pre-operative simulation of pediatric mastoid surgery with 3D-printed temporal bone models

OBJECTIVES As the process of additive manufacturing, or three-dimensional (3D) printing, has become more practical and affordable, a number of applications for the technology in the field of pediatric otolaryngology have been considered. One area of promise is temporal bone surgical simulation. Having previously developed a model for temporal bone surgical training using 3D printing, we sought to produce a patient-specific model for pre-operative simulation in pediatric otologic surgery. Our hypothesis was that the creation and pre-operative dissection of such a model was possible, and would demonstrate potential benefits in cases of abnormal temporal bone anatomy. METHODS In the case presented, an 11-year-old boy underwent a planned canal-wall-down (CWD) tympano-mastoidectomy for recurrent cholesteatoma preceded by a pre-operative surgical simulation using 3D-printed models of the temporal bone. The models were based on the childs pre-operative clinical CT scan and printed using multiple materials to simulate both bone and soft tissue structures. To help confirm the models as accurate representations of the childs anatomy, distances between various anatomic landmarks were measured and compared to the temporal bone CT scan and the 3D model. RESULTS The simulation allowed the surgical team to appreciate the childs unusual temporal bone anatomy as well as any challenges that might arise in the safety of the temporal bone laboratory, prior to actual surgery in the operating room (OR). There was minimal variability, in terms of absolute distance (mm) and relative distance (%), in measurements between anatomic landmarks obtained from the patient intra-operatively, the pre-operative CT scan and the 3D-printed models. CONCLUSIONS Accurate 3D temporal bone models can be rapidly produced based on clinical CT scans for pre-operative simulation of specific challenging otologic cases in children, potentially reducing medical errors and improving patient safety.

Outcomes of static and dynamic facial nerve repair in head and neck cancer.

Determine outcomes associated with nerve grafting versus static repair following facial nerve resection.

Are wider surgical margins needed for early oral tongue cancer

BACKGROUND Traditionally, a 1-cm surgical resection margin is used for early oral tongue tumours. METHODS All tumour stage one (n = 65) and stage two (n = 13) oral tongue cancers treated between January 1999 and January 2009 were followed for a median of 38 months (minimum 12 months). The sites of close and involved margins were histologically reviewed. RESULTS Involved and close margins occurred in 14 and 55 per cent of cases, respectively. The number of involved vs clear or close margins was equivalent in tumour stage one (90 vs 82 per cent), node-negative (100 vs 84 per cent) and perineural or lymphovascular invasion (20 vs 21 per cent) cases. Close or involved margins were similarly likely to be posterior (59 per cent) as anterior (41 per cent, p = 0.22), lateral (57 per cent) as medial (43 per cent, p = 0.34), and mucosal (59 per cent) as deep (41 per cent, p = 0.22). Local recurrence occurred in 28 per cent of cases at a median of 12 months, and was more likely in cases with involved (50 per cent) than clear or close margins (25 per cent, p = 0.10). Disease-free survival was worse in involved margins cases (p = 0.002). CONCLUSION Involved margins are common in early tongue tumours, and are associated with increased local recurrence and worse survival. Close or involved margins occur in all directions and all tumour types. A wider margin may be justified.

Functional outcomes following secondary free flap reconstruction of the head and neck

To evaluate head and neck patients undergoing secondary (delayed) free flap reconstructions.

Intracochlear electrocochleography during cochlear implantation

Objective Electrophysiologic responses to acoustic stimuli are present in nearly all cochlear implant recipients when measured at the round window (RW). Intracochlear recording sites might provide an even larger signal and improve the sensitivity and the potential clinical utility of electrocochleography (ECoG). Thus, the goal of this study is to compare RW to intracochlear recording sites and to determine if such recordings can be used to monitor cochlear function during insertion of a cochlear implant. Methods Intraoperative ECoG recordings were obtained in subjects receiving a cochlear implant from the RW and from just inside scala tympani (n = 26). Stimuli were tones at high levels (80–100 dB HL). Further recordings were obtained during insertions of a temporary lateral cochlear wall electrode (n = 8). Response magnitudes were determined as the sum of the first and second harmonics amplitudes. Results All subjects had measurable extracochlear responses at the RW. Twenty cases (78%) showed a larger intracochlear response, compared with three (11%) that had a smaller response and three that were unchanged. On average, signal amplitudes increased with increasing electrode insertion depths, with the largest increase between 15 and 20 mm from the RW. Conclusion ECoG to acoustic stimuli via an intracochlear electrode is feasible in standard cochlear implant recipients. The increased signal can improve the speed and efficiency of data collection. The growth of response magnitudes with deeper intrascalar electrode positions could be explained by closer proximity or favorable geometry with respect to residual apical signal generators. Reductions in magnitude may represent unfavorable geometry or cochlear trauma.

Intraoperative Real-time Cochlear Response Telemetry Predicts Hearing Preservation in Cochlear Implantation.

Aim: To monitor cochlear function during cochlear implantation and determine correlations with postoperative acoustic hearing. Background: Cochlear response telemetry measures cochlear function directly from cochlear implant electrodes. We have adapted this system to provide real-time cochlear response telemetry (RT-CRT) monitoring of a patients acoustic hearing as the cochlear implant electrode array is inserted. Methods: Eighteen subjects (1 child and 17 adults) with sloping high frequency hearing loss were implanted with Cochlear Ltd slim straight arrays (CI422/CI522). Tone bursts (500 Hz, 100–110 dB) were presented at 14 Hz continuously during the array insertion. RT-CRT amplitudes were correlated with surgical manoeuvres recorded on the video from the operating microscope and with postoperative pure tone audiograms. Results: Despite an excellent overall rate of complete or partial hearing preservation (79%), RT-CRT identified that in 47% of these implantations there was transient or permanent reduction in the amplitude of the cochlear microphonic (CM). Patients with a preserved CM at the end of insertion had on average 15 dB better low-frequency hearing preservation. The CM amplitude was most vulnerable during the last few millimeters of insertion or when inadvertent movement of the array occurred after full insertion. Physical contact/elevation of the basilar membrane is hypothesized as a likely mechanism of hearing loss rather than overt physical trauma. Conclusion: RT-CRT can be used to predict early postoperative hearing loss and to potentially refine surgical technique. In the future, feedback of RT-CRT may prove to be a valuable tool for maximizing preservation of residual hearing or providing feedback on electrode contact with the basilar membrane.

Round window electrocochleography and speech perception outcomes in adult cochlear implant subjects: Comparison with audiometric and biographical information

Hypothesis Intraoperative round window (RW) electrocochleography (ECoG) can help predict speech perception outcomes in adult cochlear implant (CI) recipients. Background Speech perception outcomes using CIs are highly variable. Recent data demonstrated that intraoperative ECoG could account for nearly half the variance in postoperative word scores. The present study seeks to update this correlation with a larger sample size and determine if addition of clinical variables improves the prediction. Methods Intraoperative RW ECoG was performed in adult subjects undergoing CI. Amplitudes of the ongoing response to tone bursts of multiple frequencies at 85 to 95 dB HL were summed to obtain the total response (ECoG-TR). ECoG-TR was correlated with postoperative speech perception scores. Multiple linear regression was used to combine clinical factors with the ECoG-TR. Results The ECoG-TR accounted for 40% of the variance in CNC word scores (n = 32). The preoperative pure tone average (PTA) was the only clinical factor with a significant correlation (r2 = 20%). The ability to predict word scores using ECoG-TR and PTA, or after addition of age and duration of hearing loss, was not significantly different from using ECoG-TR alone. For 2 outliers, ECoG-TR predicted a better word score than obtained. Conclusions The measurement of cochlear physiology before CI, reduced to a single variable, is a better predictor of postoperative speech perception than common clinical factors. Additional analysis of the outliers showed that waveform morphology can provide distinct information in individual cases.

Intraoperative round window electrocochleography and speech perception outcomes in pediatric cochlear implant recipients.

Objectives: The goal was to measure the magnitude of cochlear responses to sound in pediatric cochlear implant recipients at the time of implantation and to correlate this magnitude with subsequent speech perception outcomes. Design: A longitudinal cohort study of pediatric cochlear implant recipients was undertaken. Intraoperative electrocochleographic (ECoG) recordings were obtained from the round window in response to a frequency series at 90 dB nHL in 77 children totaling 89 ears (12 were second side surgeries) just before device insertion. The increase in intraoperative time was approximately 10 min. An ECoG “total response” metric was derived from the summed magnitudes of significant responses to the first, second, and third harmonics across a series of frequencies. A subset of these children reached at least 9 months of implant use and were old enough for the phonetically balanced kindergarten (PB-k) word test to be administered (n = 26 subjects and 28 ears). PB-k scores were compared to the ECoG total response and other biologic and audiologic variables using univariate and multiple linear regression analyses. Results: ECoG responses were measurable in almost all ears (87 of 89). The range of ECoG total response covered about 60 dB (from ~0.05 to 50 &mgr;V). Analyzing individual ECoG recordings in bilaterally implanted children revealed poor concordance between the measured response in the first versus second ear implanted (r2 = 0.21; p = 0.13; n = 12). In a univariate linear regression, the ECoG total response was significantly correlated with PB-k scores in the subset of 26 subjects who were able to be tested and accounted for 32% of the variance (p = 0.002, n = 28). Preoperative pure-tone average (PTA) accounted for slightly more of the variance (r2 = 0.37, p = 0.001). However, ECoG total response and PTA were significantly but only weakly correlated (r2 = 0.14, p = 0.001). Other significant predictors of speech performance included hearing stability (stable versus progressive) and age at testing (22 and 16% of the variance, respectively). In multivariate analyses with these four factors, the ECoG accounted for the most weight (&bgr; = 0.36), followed by PTA (&bgr; = 0.26). In a hierarchical multiple regression analysis, the most parsimonious models that best predicted speech perception outcomes included three variables: ECoG total response, and any two of preoperative PTA, age at testing, or hearing stability. The various three factor models each predicted approximately 50% of the variance in word scores. Without the ECoG total response, the other three factors predicted 36% of variance. Conclusions: Intraoperative round window ECoG recordings are reliably and easily obtained in pediatric cochlear implant recipients. The ECoG total response is significantly correlated with speech perception outcomes in pediatric implant recipients and can account for a comparable or greater proportion of variance in speech perception than other bio-audiologic factors. Intraoperative recordings can potentially provide useful prognostic information about acquisition of open set speech perception in implanted children.

Postoperative Reirradiation for Mucosal Head and Neck Squamous Cell Carcinomas

OBJECTIVES To compare toxic effects and functional outcomes of reirradiation with and without salvage surgery for nonnasopharyngeal mucosal head and neck squamous cell carcinoma. DESIGN Retrospective review. SETTING Academic tertiary referral hospital. PATIENTS Between December 1992 and March 2007, a total of 87 patients underwent reirradiation (64 for cure and 23 for palliation). INTERVENTION Patients underwent reirradiation with (n = 38) or without salvage surgery (n = 49). After January 2000 there was increased use of concurrent platinum-based chemotherapy (80% vs 5%) and intensity-modulated radiation therapy (82% vs 0%). MAIN OUTCOME MEASURES Early and late toxic effects of treatment by Radiation Therapy Oncology Group criteria, tracheostomy retention, gastrostomy tube dependence, and survival. RESULTS The median follow-up among patients alive at last contact was 5.0 years. Compared with reirradiation without surgery, postoperative reirradiation was associated with increased early grade 3 to grade 5 toxic effects (50% [19 of 38] vs 29% [14 of 49], P = .04) and with longer median survival (17.3 vs 8.9 months, P < .001). Free-flap reconstruction decreased early toxic effects in the surgical cohort by 16% (from 60% [9 of 15] to 43% [10 of 23], P = .32). Gastrostomy tube dependence (P = .05) and tracheostomy retention (P = .04) have increased since 2000. The median survival for curative patients was 12.5 months. The estimated 2-year survival was 25%, and the estimated 5-year survival was 8%. CONCLUSIONS Reirradiation represents the only chance for cure in patients with unresectable disease. After surgery, reirradiation is performed in patients at high risk of locoregional recurrence and may increase acute toxic effects. However, free-flap reconstruction may reduce toxic effects. Functional outcomes have declined since 2000 likely because of the addition of concurrent platinum-based chemotherapy. Future research may define the subpopulation of postoperative patients for whom survival benefits most outweigh reirradiation toxic effects.