Ultrasound-guided fine-needle aspiration of the tongue base: a cadaver feasibility study

The Usefulness of Saturated Salt Solution Embalming Method for Oral Surgical Skills Training: A New Cadaveric Training Model for Bone Harvesting

The purpose of this study was to assess the usefulness of saturated salt solution-embalmed cadavers for oral surgical skills training related to bone graft harvesting. Two half-day surgical skills training workshops were held at the Tokyo Medical University utilizing eight cadavers embalmed with the saturated salt solution. A total of 22 participants including oral surgeons, residents, and dentists attended the workshop. Surgical training consisted of six procedures related to intraoral and extraoral bone harvesting. The participants were surveyed to assess self-confidence levels for each surgical procedure before and after completion of each workshop. The Wilcoxon signed-rank test was used to compare the differences between each median score before and after the workshop. There were statistically significant increases in the self-assessed confidence scores in bone harvesting procedures for the zygomatic bone (P = 0.003), maxillary tuberosity (P = 0.002), and other sites (P < 0.001). The anatomical features of saturated salt solution-embalmed cadavers were also examined. The textures of the oral mucosa and skin were similar to those of living individuals. The structure of bone tissues was well-preserved and the hardness was realistic. Consequently, all procedures were performed with sufficient realism. The saturated salt solution method has a relatively low cost of preparation and storage, and almost no odor. The authors suggest that saturated salt solution-embalmed cadavers could provide a new model for oral surgical skills training in bone harvesting.

Feasibility of In-office Fine-Needle Aspiration for Base of Tongue Tumors

We aim to demonstrate the feasibility of in-office transcervical ultrasound (TCUS)-guided fine-needle aspiration (FNA) of base of tongue (BOT) tumors in a single-institution. Retrospective chart review was performed and 3 patients met criteria, with BOT tumors ≥3 cm . Two patients had no cervical adenopathy, while FNA of a cervical lymph node was inconclusive in patient 3. Two patients had multiple medical comorbidities rendering them high risk for general anesthesia, and 1 patient had a BOT tumor obscuring visualization of the glottis, which would have precluded intubation and potentially required tracheostomy to proceed. All patients underwent successful in-office TCUS-guided FNA, with results showing squamous cell carcinoma. There were no related complications. In-office TCUS-guided FNA can be used for diagnosis of BOT lesions that are evident on ultrasound. This is beneficial in cases where general anesthesia is considered high risk. Additionally, 1 patient safely continued anticoagulation, and another was able to avoid tracheostomy. This technique is cost-effective as it avoids the expenses associated with operative intervention.

Assessment of Thiel-Embalmed Cadavers as a Teaching Tool for Oral Anatomy and Local Anesthesia

The aim of this study was to determine whether Thiel-embalmed cadavers would provide a useful anatomy teaching tool for topics that cannot be approached using formalin-fixed cadavers such as oral cavity examination and maxillary anesthesia. The suitability of Thiel-embalmed bodies for performing oral examinations was assessed by asking first-year dental and dental hygiene students at a dental school in Ireland to identify oral structures on a classmate and on a Thiel-embalmed body. The study was conducted in 2016. The ease of location was compared in the two settings, and their quality was assessed on the cadavers. The suitability of Thiel-embalmed cadavers to teach maxillary anesthesia was assessed by students' performing mock injections at five adjacent sites daily for five consecutive days, followed by inspection of the gingival surface by experienced anatomists and dentists. Data were obtained from 57 students, but only the 54 forms that were fully completed were analyzed, for an overall response rate of 85.7%. The results showed that most oral structures were more difficult to locate on cadavers. The texture and appearance of features in the cadavers were rated at a midpoint between realistic and unrealistic. The relative inexperience of the participants, the accumulation of fixative in the oral cavity, and discoloration were mentioned as potential confounding factors. Visual analysis of images obtained following repeated injections revealed no deterioration of the tissue. Importantly, the puncture marks appeared to reduce over time, suggesting that the gingival tissue maintains some elasticity following Thiel fixation. These findings suggest that Thiel-embalmed cadavers may be a useful tool to provide students more time to localize and study aspects of the oral cavity. Likewise, the recoiling capacity of gingival tissue suggests that Thiel-embalmed cadavers may provide an ideal tool for teaching injection technique of local anesthetics.

Ultrasound-Guided Needle Biopsy for Diagnosis of Advanced-Stage Malignancies of the Upper Aerodigestive Tract

Objective

Traditionally, direct laryngoscopy confirms stage and tissue diagnosis prior to treatment planning. Patients who are frail or have tenuous airway anatomy may incur risks while undergoing anesthesia. Further, direct laryngoscopy is scheduled after initial examination, introducing diagnosis delay. This study investigates the impact of ultrasound examination with guided needle biopsy compared with traditional operative biopsy.

Study Design

Case series.

Setting

Tertiary head and neck clinic.

Subjects and Methods

The records of patients at the Veterans Affairs Medical Center Memphis and Regional One Health who had supraglottic, oropharyngeal, and hypopharyngeal cancer that was diagnosed by ultrasound needle biopsy were reviewed from 2011 to 2016. Demographics, stage, biopsy results, and treatment were abstracted.

Results

Seventeen patients who underwent ultrasound-guided needle biopsy of the primary site were included. Average age was 63 years old, and 65% of patients were stage T4 (11/17). Needle biopsy yielded malignant cells in 76% (13/17). Eleven patients were included in subsequent analysis because 6 patients underwent needle biopsy only. Fisher exact test showed no difference between the 2 methods (P = .27). Sensitivity was 86% and specificity was 100%. Seven patients had a median potential delay in diagnosis of 10 days.

Conclusions

Ultrasound can be used effectively to obtain a tissue diagnosis, circumventing an operative biopsy. Moreover, ultrasound may provide additional imaging details to support accurate staging. This strategy may prove worthwhile to cut costs and reduce delay to staging, reduce risk for those with contraindications to anesthesia, and increase staging accuracy via enhanced imaging details.

Ultrasound-Guided Transcutaneous Needle Biopsy of the Base of the Tongue and Floor of the Mouth From a Submental Approach

Limited data exist regarding the feasibility of ultrasound-guided transcutaneous biopsy of the base of the tongue and floor of the mouth. This retrospective study reviewed 8 cases with lesions in the base of the tongue or floor of the mouth that were biopsied by fine-needle aspiration. Core biopsy was also needed in 1 case. All biopsies were technically successful, and all yielded squamous cell carcinoma. One biopsy yielded a false-positive result, as subsequent resection yielded high-grade dysplasia with no invasion. The other biopsy results were considered true-positive based on subsequent pathologic examinations (2 cases) or clinical/imaging follow-up (5 cases). There were no significant complications associated with the biopsies.

Transcervical ultrasonography is feasible to visualize and evaluate base of tongue cancers

Background

Base of tongue (BOT) is a difficult subsite to examine clinically and radiographically. Yet, anatomic delineation of the primary tumor site, its extension to adjacent sites or across midline, and endophytic vs. exophytic extent are important characteristics for staging and treatment planning. We hypothesized that ultrasound could be used to visualize and describe BOT tumors.

Methods

Transcervical ultrasound was performed using a standardized protocol in cases and controls. Cases had suspected or confirmed BOT malignancy. Controls were healthy individuals without known malignancy.

Results

100% of BOT tumors were visualized. On ultrasound BOT tumors were hypoechoic (90.9%) with irregular margins (95.5%). Ultrasound could be used to characterize adjacent site involvement, midline extent, and endophytic extent, and visualize the lingual artery. No tumors were suspected for controls.

Conclusions

Ultrasonography can be used to transcervically visualize BOT tumors and provides clinically relevant characteristics that may not otherwise be appreciable.

In vivo ultrasonic detection of polyurea crosslinked silica aerogel implants

Background

Polyurea crosslinked silica aerogels are highly porous, lightweight, and mechanically strong materials with great potential for in vivo applications. Recent in vivo and in vitro studies have demonstrated the biocompatibility of this type of aerogel. The highly porous nature of aerogels allows for exceptional thermal, electric, and acoustic insulating capabilities that can be taken advantage of for non-invasive external imaging techniques. Sound-based detection of implants is a low cost, non-invasive, portable, and rapid technique that is routinely used and readily available in major clinics and hospitals.

Methodology

In this study the first in vivo ultrasound response of polyurea crosslinked silica aerogel implants was investigated by means of a GE Medical Systems LogiQe diagnostic ultrasound machine with a linear array probe. Aerogel samples were inserted subcutaneously and sub-muscularly in a) fresh animal model and b) cadaveric human model for analysis. For comparison, samples of polydimethylsiloxane (PDMS) were also imaged under similar conditions as the aerogel samples.

Conclusion/significance

Polyurea crosslinked silica aerogel (X-Si aerogel) implants were easily identified when inserted in either of the regions in both fresh animal model and cadaveric model. The implant dimensions inferred from the images matched the actual size of the implants and no apparent damage was sustained by the X-Si aerogel implants as a result of the ultrasonic imaging process. The aerogel implants demonstrated hyperechoic behavior and significant posterior shadowing. Results obtained were compared with images acquired from the PDMS implants inserted at the same location.