Purely nasal floor mucosa-free graft for reconstruction after endoscopic endonasal transellar approach: an anatomical and clinical analysis.

BACKGROUND/OBJECTIVE: In this radioanatomical study with clinical correlate, we study a variation of the 'extended nasal floor mucosa' (ENFM) free-graft, the purely nasal floor mucosa (PuNFM) free-graft. The objectives of this study are to evaluate the coverage surface area provided by the PuNFM, study the adequacy of the PuNFM in the reconstruction of endoscopic endonasal approach (EEA) transsellar postoperative defects and compare and evaluate this reconstructive technique with current sellar region reconstruction practices. METHODS: Dissections were performed on five cadaveric specimens. PuNFM were harvested bilaterally and the area provided for reconstruction was calculated. Twenty-five consecutive cases of pituitary adenomas resected through an EEA were analyzed to estimate the sellar defect surface area (SDSA) after a transsellar EEA and calculate the area of PuNFM bilaterally. RESULTS: The median cadaveric SDSA was 4.77 cm2, with a median left and right side PuNFM area of 5.09 and 5.19 cm2, respectively. Clinically, the median SDSA was 5.36 cm2, and the total radiological PuNFM surface area was 5.46 cm2, with modified Knosp grade >2 tumors having larger SDSA than that of Knosp grade <2 tumors. The PuNFM graft proved to be most effective for covering modified Knosp <2 tumor defects. CONCLUSIONS: The PuNFM represents a variation of the ENFM free-graft sellar defect reconstruction technique that provides sufficient surface area to reconstruct the majority of the sellar defects related to transsellar EAA for pituitary adenomas. This technique may positively impact sinonasal function and quality of life. Future prospective clinical studies are needed to verify these findings.

Radial Forearm Free Flap with Parapharyngeal Pedicle Corridor for Reconstruction of Anterior Skull Base Defects.

BACKGROUND: The radial forearm free flap (RFFF) is an indispensable tool for the reconstruction of a range of defects, including those of the skull base. Several options for routing of the RFFF pedicle have been described, and the parapharyngeal corridor (PC) has been proposed as an option and employed for a nasopharyngeal defect. However, there are no reports of its use for the reconstruction of anterior skull base defects. The objective of this study is to describe the technique for free tissue reconstruction of anterior skull base defects using the RFFF and routing of the pedicle via the PC. METHODS: Relevant neurovascular landmarks and critical surgical steps for reconstruction of anterior skull base defects with an RFFF and routing of the pedicle via the PC are reported using an illustrative clinical case and cadaveric dissections. RESULTS: We present a case of a 70-year-old man who underwent endoscopic transcribriform resection of cT4N0 sinonasal squamous cell carcinoma and was left with a large anterior skull base defect that persisted despite several repair attempts. An RFFF was utilized to repair the defect. This report is the first description of the clinical use of the PC for free tissue repair of an anterior skull base defect. CONCLUSIONS: The PC is an option for routing the pedicle during the reconstruction of anterior skull base defects. When the corridor is prepared as described in this case, a direct route exists from the anterior skull base to cervical vessels, simultaneously maximizing the reach of the pedicle and minimizing the risk of kinking.

Specimen-Based Resection Margins and Local Control during Transoral Robotic Surgery for Oropharyngeal HPV-Mediated Squamous Cell Carcinoma.

OBJECTIVES: The aim of the study was to investigate the association of surgical margin conditions, including positive specimen margins revised to negative relative to local recurrence, disease-free survival, and overall survival (OS) within a cohort of HPV-mediated oropharyngeal squamous cell carcinoma (OPSCC) who underwent en bloc resection via transoral robotic surgery (TORS). MATERIALS AND METHODS: Retrospective cohort of patients with untreated HPV-mediated OPSCC cT1 or T2 undergoing TORS resection between October 2014 and March 2020. The methodologic description of our interdisciplinary institutional approach, number of cut-through margins (CTMs) during intraoperative consultation, percentage of final positive margin cases, and disease-free survival and OS stratified by margin status and margin tumor-free distance is identified. RESULTS: 135 patients with primary cT1/T2 HPV-mediated OPSCC met inclusion criteria. Twenty-eight of 135 (20.7%) specimens revealed CTM and were revised during the same operative setting. Three of 135 (2.2%) surgical cases had positive final margin status. Local control rate was 97%. On univariate analysis, margin distance did not impact OS. CTM and final positive margins had lower OS than initially negative margins (p = 0.044). Pathologic N-stage significantly impacted OS (p < 0.001). CONCLUSIONS: High local control rate and low final positive margin status confound the study of specimen margin-based techniques in HPV-mediated OPSCC resected en bloc with TORS. Pathologic N-stage may impact OS more than margin status. Larger numbers are needed to confirm differences.

A Cost-Effective and Reproducible Cadaveric Training Model for Internal Carotid Artery Injury Management During Endoscopic Endonasal Surgery: The Submersible Peristaltic Pump.

BACKGROUND: Internal carotid artery injury (ICAI) represents one of the most challenging complications in endoscopic endonasal neurosurgery and its rarity results in limited opportunities for trainees and surgeons to achieve proficiency in its management. Currently, available models for ICAI have employed costly systems that prevent their widespread use. The objective of this study is to validate an affordable submersible peristaltic pump (SPP)-based model as a reproducible and realistic paradigm for ICAI management training. METHODS: A laceration of the left parasellar internal carotid artery was purposely carried out in 2 human cadaveric heads. A blood substitute was perfused to ensure a perfusion flow of 1 L/min using an affordable SPP. A cohort of 20 neurosurgery and otolaryngology residents, fellows, and attendings were enrolled to evaluate the realism and content validity of the model using a validated 5-grade questionnaire. RESULTS: The model proved to mimic a real intraoperative scenario of ICAI with an expected output flow of 1 L/min. Questionnaire responses reported a realistic experience and the impact of this model on improving trainee surgical coordination and capability to rehearse the most accepted repair technique. The use of a fixed noninjected head allowed the reproducibility of the training session without the additional cost of new fresh-frozen heads. The affordable SPP allowed an impactful reduction of ICAI model training expenses maintaining high realism. CONCLUSIONS: The SPP-based ICAI model with noninjected cadaveric specimens is an affordable and cost-effective system that allows reproducibility and realism. These qualities favor greater adoption in neurosurgery and otolaryngology training curricula.

Contralateral Transmaxillary Approach to Petrous Apex Granuloma with Lateral Maxillotomy: 2-Dimensional Operative Video.

The endoscopic endonasal approach (EEA) has proven to be a valuable tool to access the petrous apex (PA).1 Although lesions located medial to the PA can be easily accessed through an EEA with minimal risk to the internal carotid artery (ICA), more laterally seated lesions represent a surgical challenge. The contralateral transmaxillary approach is an effective extension of the normal EEA to the PA, allowing a more lateral trajectory and thereby reducing the risks connected to paraclival ICA manipulation.2-4 This is a 47-year-old female presenting with tinnitus, hearing loss, and right facial twitching. The preoperative audiogram showed a 60 dB sensorineural hearing loss, and magnetic resonance imaging demonstrated an expansive lesion of the PA with high signal intensity in T1- and T2-weighted sequences. A high-riding jugular bulb ruled out the use of an infracochlear infralabyrinthine approach, and a middle cranial fossa approach was felt to render a high risk of recurrence due to the potential for incomplete resection. Ultimately, a contralateral transmaxillary approach was selected. Due to the extreme lateral position of the lesion, the maxillotomy was created in the lateral wall of the maxillary sinus to allow a coaxial approach to the PA. Postoperatively, the patient did not report new neurologic deficits. Anatomic pathology was consistent with cholesterol granuloma (Video 1). In the surgical management of PA granulomas, recognizing relevant anatomic structures such as the paraclival ICA, cochlea, jugular bulb, and vestibule preoperatively is of paramount importance to tailor the surgical approach and reduce its risks.

How do hospital inpatients conceptualise patient safety? A qualitative interview study using constructivist grounded theory.

BACKGROUND: Efforts to involve patients in patient safety continue to revolve around professionally derived notions of minimising clinical risk, yet evidence suggests that patients hold perspectives on patient safety that are distinct from clinicians and academics. This study aims to understand how hospital inpatients across three different specialties conceptualise patient safety and develop a conceptual model that reflects their perspectives. METHODS: A qualitative semi-structured interview study was conducted with 24 inpatients across three clinical specialties (medicine for the elderly, elective surgery and maternity) at a large central London teaching hospital. An abbreviated form of constructivist grounded theory was employed to analyse interview transcripts. Constant comparative analysis and memo-writing using the clustering technique were used to develop a model of how patients conceptualise patient safety. RESULTS: While some patients described patient safety using terms consistent with clinical/academic definitions, patients predominantly conceptualised patient safety in the context of what made them 'feel safe'. Patients' feelings of safety arose from a range of care experiences involving specific actors: hospital staff, the patient, their friends/family/carers, and the healthcare organisation. Four types of experiences contributed to how patients conceptualise safety: actions observed by patients; actions received by patients; actions performed by patients themselves; and shared actions involving patients and other actors in their care. CONCLUSIONS: Our findings support the need for a patient safety paradigm that is meaningful to all stakeholders, incorporating what matters to patients to feel safe in hospital. Additional work should explore and test how the proposed conceptual model can be practically applied and implemented to incorporate the patient conceptualisation of patient safety into everyday clinical practice.

The Role of Allergic Rhinitis in Chronic Rhinosinusitis.

This literature review collates and summarizes recent literature to explore the relationship between chronic rhinosinusitis (CRS) and allergy. The relationship between CRS and allergy is not fully understood. However, current evidence suggests a relationship between allergy and specific endotypes of CRS with nasal polyposis, including allergic fungal rhinosinusitis and central compartment atopic disease. Specific endotypes of CRS with nasal polyps seem to have an association with allergy. More evidence is necessary to better characterize this relationship. Level of evidence: 5.

Botulinum Toxin-A Dosing Trends for Adductor Spasmodic Dysphonia at a Single Institution Over 10 Years.

OBJECTIVES: This study aimed to identify the changes in dosing of botulinum toxin-A for adductor spasmodic dysphonia (ADSD) over a prolonged period. STUDY DESIGN: This is a retrospective chart review. METHODS: One hundred thirteen subjects treated for ADSD from 2003 to 2013 were identified from a clinical database. Subject age, gender, and total injection dose amount were all recorded for all subjects who had at least 10 injections. RESULTS: Fifty-four subjects met criteria for inclusion. There were no age or gender differences in the starting dose for subjects. Dosing decreased significantly compared with the second dose (5.05 ± 1.623 Units), by the sixth dose (4.26 ± 1.698 Units), and continued through the 10th dose (4.08 ± 2.019 Units) (P < 0.005 for all). CONCLUSIONS: Botulinum toxin-A dosing for ADSD decreases consistently over subsequent injections after the initial two dose titrations.

Systematic Review of Hospital Readmissions in Stroke Patients.

Background. Previous evidence on factors and causes of readmissions associated with high-impact users of stroke is scanty. The aim of the study was to investigate common causes and pattern of short- and long-term readmissions stroke patients by conducting a systematic review of studies using hospital administrative data. Common risk factors associated with the change of readmission rate were also examined. Methods. The literature search was conducted from 15 February to 15 March 2016 using various databases, such as Medline, Embase, and Web of Science. Results. There were a total of 24 studies (n = 2,126,617) included in the review. Only 4 studies assessed causes of readmissions in stroke patients with the follow-up duration from 30 days to 5 years. Common causes of readmissions in majority of the studies were recurrent stroke, infections, and cardiac conditions. Common patient-related risk factors associated with increased readmission rate were age and history of coronary heart disease, heart failure, renal disease, respiratory disease, peripheral arterial disease, and diabetes. Among stroke-related factors, length of stay of index stroke admission was associated with increased readmission rate, followed by bowel incontinence, feeding tube, and urinary catheter. Conclusion. Although risk factors and common causes of readmission were identified, none of the previous studies investigated causes and their sequence of readmissions among high-impact stroke users.

In-office drainage of sinus Mucoceles: An alternative to operating-room drainage.

OBJECTIVES/HYPOTHESIS: Endoscopic drainage has become the standard of care for the treatment of mucoceles. In many patients this can be performed in the office. This study reviews our experience with in-office endoscopic mucocele drainage. STUDY DESIGN: Retrospective chart review. METHODS: A retrospective review of one surgeon's experience with in-office endoscopic drainage of sinus mucoceles between 2006 and 2014 was performed. Charts were reviewed for patient demographics, previous surgery, mucocele location, bone erosion, and outcomes. RESULTS: Thirty-two patients underwent 36 in-office drainage procedures. All procedures were performed under topical/local anesthesia. The mean age was 55 years (range, 17-92 years). The mean follow-up time was 444 days. Fifty-five percent had previous sinus surgery. The primary sinus involved was the frontal (12), anterior (11), posterior ethmoid (six), maxillary (four), and sphenoid (two). Bone erosion was noted to be present on computed tomography in 18 mucoceles (51%) (16 orbital, seven skull-base). All mucoceles were successfully accessed in the office with the exception of one, which was aborted due to neo-osteogenesis. Five patients (14% of mucoceles) required additional surgery, two for mucocele recurrence and three for septated mucoceles not completely drained in the office. No treatment complications occurred. All but one patient preferred in-office to operating-room drainage. CONCLUSIONS: In-office drainage of sinus mucoceles is well tolerated by patients, with high success and low complication rates, even in large mucoceles with bone erosion. The presence of septations and neo-osteogenesis reduce the likelihood of complete drainage and are relative contraindications. Orbital and skull base erosion are not contraindications. LEVEL OF EVIDENCE: 4.

Safety and efficacy of multiuse botulinum toxin vials for intralaryngeal injection.

OBJECTIVES/HYPOTHESIS: Centers for Disease Control and Prevention guidelines maintain that single-use vials cannot be used for multiple patients. Botox product labeling states that the reconstituted toxin should be used within 4 hours on a single patient based on concerns of reduced potency, contamination, and consequent infections. The purpose of this study was to determine the safety and efficacy of using single-use vials in a multidose fashion. STUDY DESIGN: Prospective study and cohort chart review. METHODS: A multi-institutional three-part study was performed between May 2013 and October 2013: 1) a summation of subjects' recall of their past experiences (symptoms/response) with previous multidose Botox injections, 2) a prospective study of intralaryngeal injections, and 3) a chart review of injection responses in a subset of the cohort. RESULTS: Seven hundred forty-three subjects receiving 6,216 injections demonstrated zero infection-related complications on retrospective chart review. One hundred seventy-nine subjects recalled 24.0% overall adverse events, 10.6% redness, 7.3% pain and swelling at the injection site, and 0% fever. One hundred seventy-four subjects prospectively reported 12.6% overall adverse events. The self-reported efficacy rate of Botox injection was 96.6%. CONCLUSIONS: The low rates of adverse events following the use of Botox in a multipatient fashion are consistent with other percutaneous injections. No evidence of infection was found with multidose Botox use. Given the low incidence of side effects and high success rate, Botox can be used both safely and effectively in a multipatient fashion. LEVEL OF EVIDENCE: 4

Regulated neuronal neuromodulation via spinal cord expression of the gene for the inwardly rectifying potassium channel 2.1 (Kir2.1).

BACKGROUND: Neuromodulation is used to restore neural function in disorders that stem from an imbalance in the activity of specific neural networks when they prove refractory to pharmacological therapy. The Kir2.1 gene contributes to stabilizing the resting potential below the threshold of activation of voltage-gated sodium channels and action potentials. Therefore, the delivery of the Kir2.1 gene to neuronal cells could reduce the probability of action potential generation, inhibiting excessive neural activity. OBJECTIVE: To address the hypothesis that overexpression of the inwardly rectifying potassium channel 2.1 (Kir2.1) gene could inhibit motor neuron activity and therefore be therapeutically used in gene-based neuromodulation. METHODS: To induce expression of Kir2.1, the inducible RheoSwitch promoter was used and controlled by ligand. In vivo gene expression was accomplished by an adenoviral vector to deliver unilaterally into the lumbar spinal cord of rats. RESULTS: Behavioral assays demonstrated that neuromuscular inhibition was exclusive to rats that received the ligand. Histological analysis also showed evidence of some motor neuron loss in these animals. Behavioral effects of Kir2.1 expression were completely reversible, arguing that the behavioral effect did not result from motor neuron death. CONCLUSION: Delivery of the gene for Kir2.1 inhibits neurons by resisting depolarization to the action potential threshold. Regulated neuronal expression of Kir2.1 may provide an elegant means for neuromodulation in a selected neuronal population.

Intramuscular administration of a VEGF zinc finger transcription factor activator (VEGF-ZFP-TF) improves functional outcomes in SOD1 rats.

Amyotrophic lateral sclerosis (ALS) is characterized by motor neuron loss leading to paralysis and death. Vascular endothelial growth factor (VEGF) has angiogenic, neurotrophic, and neuroprotective properties, and has preserved neuromuscular function and protected motor neurons in rats engineered to overexpress the human gene coding the mutated G93A form of the superoxide dismutase-1 (SOD1). We assessed the effects of intramuscular administration of a plasmid that encodes a zinc finger protein transcription factor (ZFP-TF) engineered to induce VEGF expression in the SOD1 rat model of ALS. Weekly injections of the plasmid preserved ipsilateral hindlimb grip strength and markedly improved rotarod performance in SOD1 rats compared to the vehicle-treated group. The number of motor neurons and the proportion of innervated neuromuscular junctions were similar in both groups. In conclusion, our data suggest that administration of the VEGF-ZFP-TF may be neuroprotective and has potential as a safe and practical approach for the management of motor disability in ALS.