Scott H. Troob

An evidence-based algorithm for intraoperative monitoring during cochlear implantation.

Objective To generate an evidence-based algorithm for the use of intraoperative testing during cochlear implantation (CI). Study Design Retrospective review. Setting Tertiary referral center. Patients A total of 277 children (aged 6 mo to 17 yr) and adults 18 years and older with normal cochlear anatomy who underwent primary and revision cochlear implantation at a single center between 2005 and 2010 were included. Intervention Intraoperative electrophysiologic monitoring and intraoperative Stenver’s view plain film radiography. Main Outcome Measure Intraoperative testing included the following: 1) individual electrode impedance measurements; 2) neural response telemetry (tNRT) levels for electrodes E20, E15, E10, and E5; and 3) plain film radiograph assessment of electrode position. Results No patient demonstrated abnormalities on all 3 modalities. Open or short electrodes on impedance testing were found in 6% of patients; half of these normalized when remeasured. Absent tNRT responses on 1 or more electrodes occurred in 14% of patients, although complete lack of response was rare (1.4%) and did not correlate with a dysfunctional device. Spread of excitation was performed in 1 patient and was consistent with a tip rollover. Intraoperative radiography identified tip-rollover and extracochlear electrode placement in all cases (n = 5, 1.8%) and prompted the use of the backup device. Conclusion Immediate intraoperative determination of device functionality and optimal electrode placement is advantageous. Of the modalities tested, including electrode impedance, tNRT, and plain radiograph, only the radiographic results impacted intraoperative surgical decision making and led to the use of the backup device.

IB4(+) and TRPV1(+) sensory neurons mediate pain but not proliferation in a mouse model of squamous cell carcinoma

BackgroundCancer pain severely limits function and significantly reduces quality of life. Subtypes of sensory neurons involved in cancer pain and proliferation are not clear.MethodsWe produced a cancer model by inoculating human oral squamous cell carcinoma (SCC) cells into the hind paw of athymic mice. We quantified mechanical and thermal nociception using the paw withdrawal assays. Neurotoxins isolectin B4-saporin (IB4-SAP), or capsaicin was injected intrathecally to selectively ablate IB4(+) neurons or TRPV1(+) neurons, respectively. JNJ-17203212, a TRPV1 antagonist, was also injected intrathecally. TRPV1 protein expression in the spinal cord was quantified with western blot. Paw volume was measured by a plethysmometer and was used as an index for tumor size. Ki-67 immunostaining in mouse paw sections was performed to evaluate cancer proliferation in situ.ResultsWe showed that mice with SCC exhibited both mechanical and thermal hypersensitivity. Selective ablation of IB4(+) neurons by IB4-SAP decreased mechanical allodynia in mice with SCC. Selective ablation of TRPV1(+) neurons by intrathecal capsaicin injection, or TRPV1 antagonism by JNJ-17203212 in the IB4-SAP treated mice completely reversed SCC-induced thermal hyperalgesia, without affecting mechanical allodynia. Furthermore, TRPV1 protein expression was increased in the spinal cord of SCC mice compared to normal mice. Neither removal of IB4(+) or TRPV1(+) neurons affected SCC proliferation.ConclusionsWe show in a mouse model that IB4(+) neurons play an important role in cancer-induced mechanical allodynia, while TRPV1 mediates cancer-induced thermal hyperalgesia. Characterization of the sensory fiber subtypes responsible for cancer pain could lead to the development of targeted therapeutics.

Effect of Overlapping Operations on Outcomes in Microvascular Reconstructions of the Head and Neck

Objective To compare outcomes after microvascular reconstructions of head and neck defects between overlapping and nonoverlapping operations. Study Design Retrospective cohort study. Setting Tertiary care center. Subjects and Methods Patients undergoing microvascular free tissue transfer operations between January 2010 and February 2015 at 2 tertiary care institutions were included (n = 1315). Patients were divided into 2 cohorts by whether the senior authors performed a single or consecutive microvascular reconstruction (nonoverlapping; n = 773, 59%) vs performing overlapping microvascular reconstructions (overlapping; n = 542, 41%). Variables reviewed were as follows: defect location, indication, T classification, surgical details, duration of the operation and hospitalization, and complications (major, minor, medical). Results Microvascular free tissue transfers performed included radial forearm (49%, n = 639), osteocutaneous radial forearm (14%, n = 182), anterior lateral thigh (12%, n = 153), fibula (10%, n = 135), rectus abdominis (7%, n = 92), latissimus dorsi (6%, n = 78), and scapula (<1%, n = 4). The mean duration of the overlapping operations was 21 minutes longer than nonoverlapping operations (P = .003). Mean duration of hospitalization was similar for nonoverlapping (9.5 days) and overlapping (9.1 days) cohorts (P = .39). There was no difference in complication rates when stratified by overlapping (45%, n = 241) and nonoverlapping (45%, n = 344) (P = .99). Subset analysis yielded similar results when minor, major, and medical complications between groups were assessed. The overall survival rate of free tissue transfers was 96%, and this was same for overlapping (96%) and nonoverlapping (96%) operations (P = .71). Conclusions Patients had similar complication rates and durations of hospitalization for overlapping and nonoverlapping operations.

The impact of prophylactic external carotid artery ligation on postoperative bleeding after transoral robotic surgery (TORS) for oropharyngeal squamous cell carcinoma

BACKGROUND Transoral robotic-assisted surgery (TORS) is increasingly utilized in the treatment of oropharyngeal squamous cell carcinoma (OPSCC). Postoperative bleeding is a significant and potentially fatal complication of TORS. Prophylactic ligation of ipsilateral external carotid artery (ECA) branches is a recognized strategy to reduce postoperative bleeding risk. We examined the incidence and sequelae of postoperative oropharyngeal bleeding with and without routine ECA ligation. METHODS OPSCC patients treated with TORS between 2010 and 2015 with minimum 30days follow up were included. Clinicopathological data, operative details, and postoperative course were abstracted for analysis. Cases of postoperative bleeding were classified as Minor, Intermediate, Major, and Severe. The incidence and severity of bleeding was compared between patients treated with and without prophylactic ECA ligation. RESULTS Bleeding after TORS was documented in 13/201 (6.5%) patients. The majority of bleeding episodes were observed among anticoagulated or previously radiated patients. By surgeon preference, 52 patients had prophylactic ECA ligation during neck dissection while the remaining 149 patients did not. There was no significant difference in overall incidence of postoperative bleeding between patients with prophylactic ECA ligation (3/52, 5.8%) and patients without (10/149, 6.7%) [p=0.53]. However, severe bleeding complications (4, 2.0%) were only observed in patients without prophylactic ligation. CONCLUSION A small but meaningful risk of bleeding after TORS for OPSCC exists, particularly among anticoagulated or previously radiated patients. Prophylactic ECA ligation did not significantly impact the overall incidence of postoperative bleeding but may reduce the risk of severe (life-threatening) bleeding.

Transoral robotic retropharyngeal node dissection

Surgical access to metastases in the retropharyngeal lymph nodes (RPLNs) could be difficult. Transoral robotic surgery (TORS) can be utilized to access RPLNs. The purpose of this study was to describe a TORS approach to RPLN dissection.

High-grade malignant transformation of a radiation-naïve nasopharyngeal angiofibroma

Nasopharyngeal angiofibromas are typically considered benign vascular neoplasms, with descriptions of high‐grade sarcomatous change found only in lesions with prior radiotherapy.

A randomized controlled trial of corticosteroids for pain after transoral robotic surgery

To determine if an extended perioperative course of corticosteroids will improve pain control following transoral robotic surgery (TORS).

Secondary free‐flap reconstruction following ablation for acute invasive fungal sinusitis

Acute invasive fungal sinusitis (AIFS) is a frequently fatal infection for which extensive and debilitating surgical debridement is a mainstay of therapy. Resulting defects are often composite in nature, mandating free tissue‐transfer reconstruction. Outcomes data for free flap reconstruction are limited. The purpose of this study was to examine surgical outcomes and survival in patients undergoing free flap transfer following invasive fungal sinusitis.

Transoral robotic retropharyngeal node dissection in oropharyngeal squamous cell carcinoma: Patterns of metastasis and functional outcomes.

Assessment of the retropharyngeal lymph nodes is essential in the treatment for oropharyngeal squamous cell carcinoma (SCC). Transoral robotic retropharyngeal lymph node dissection (RPLND) may provide valuable staging information and guide selection of adjuvant therapy in a transoral robotic surgery (TORS) treatment paradigm.

Primary Natural Killer T Cell Lymphoma of the Supraglottis

Objective: Describe an especially rare case, primary natural killer (NK) T Cell lymphoma of the supraglottis. Because of its unique presentation and infrequent occurrence, treatment in this case was delayed while awaiting a definitive diagnosis. Presentation of this case and the review of the literature should aid in the differential diagnosis. Method: The patient’s medical records including his clinical history, laboratory, radiologic, and pathologic data were reviewed. Additionally, a literature search was performed for cases of laryngeal lymphoma, with special attention to NK T-cell type. Results: A 22-year old male from South America presented with 2 months of odynophagia, hoarseness, fever, hemoptysis, night sweats, and a 70-pound weight loss. Work up for tuberculosis, HIV, and serologies for systemic granulomatous conditions were negative. Otolaryngologic evaluation demonstrated normal-appearing nasal mucosa and oral cavity. Laryngoscopy revealed a thickened epiglottis with polypoid mucosa of the vallecula and the supraglottis. Biopsy of the epiglottis demonstrated NK T cell lymphoma, nasal-type with CD3 and CD56 positivity and histologic features of an aggressive EBV-associated form. Imaging and bone marrow biopsy confirmed its confinement to the supraglottis. He is currently undergoing concurrent chemo-radiation therapy. Conclusion: Lymphoma of the larynx represents 1% of malignant laryngeal tumors. Primary laryngeal NK T cell lymphoma with disease isolated to the larynx is exceptionally rare and has not previously been reported. Medical work up to rule out infectious or inflammatory lesions along with directed biopsies should help in the diagnosis.