Dysfunctional Epithelial Barrier Is Characterized by Reduced E-Cadherin in Idiopathic Subglottic Stenosis

OBJECTIVES

To aim of the study was to characterize the molecular profile and functional phenotype of idiopathic subglottic stenosis (iSGS)-scar epithelium.

METHODS

Human tracheal biopsies from iSGS scar (n = 6) and matched non-scar (n = 6) regions were analyzed using single-cell RNA sequencing (scRNA-seq). Separate specimens were used for epithelial cell expansion in vitro to assess average growth rate and functional capabilities using transepithelial-electrical resistance (TEER), fluorescein isothiocyanate-dextran flux permeability assay, ciliary coverage, and cilia beating frequency (CBF). Finally, epithelial tight junction protein expression of cultured cells was quantified using immunoblot assay (n = 4) and immunofluorescence (n = 6).

RESULTS

scRNA-seq analysis revealed a decrease in goblet, ciliated, and basal epithelial cells in the scar iSGS cohort. Furthermore, mRNA expression of proteins E-cadherin, claudin-3, claudin-10, occludin, TJP1, and TJP2 was also reduced (p < 0.001) in scar epithelium. Functional assays demonstrated a decrease in TEER (paired 95% confidence interval [CI], 195.68-890.83 Ω × cm2 , p < 0.05), an increase in permeability (paired 95% CI, -6116.00 to -1401.99 RFU, p < 0.05), and reduced epithelial coverage (paired 95% CI, 0.1814-1.766, fold change p < 0.05) in iSGS-scar epithelium relative to normal controls. No difference in growth rate (p < 0.05) or CBF was found (paired 95% CI, -2.118 to 3.820 Hz, p > 0.05). Immunoblot assay (paired 95% CI, 0.0367-0.605, p < 0.05) and immunofluorescence (paired 95% CI, 13.748-59.191 mean grey value, p < 0.05) revealed E-cadherin reduction in iSGS-scar epithelium.

CONCLUSION

iSGS-scar epithelium has a dysfunctional barrier and reduced structural protein expression. These results are consistent with dysfunctional epithelium seen in other airway pathology. Further studies are warranted to delineate the causality of epithelial dysfunction on the downstream fibroinflammatory cascade in iSGS.

LEVEL OF EVIDENCE

NA Laryngoscope, 134:374-381, 2024.

Murine Model of Airway Fibrosis has Anatomic, Physiologic, and Molecular Congruency to Human iSGS

OBJECTIVE

To narrow knowledge gaps in the pathophysiology of idiopathic subglottic stenosis (iSGS) through comparison of a murine subglottic stenosis model with iSGS.

STUDY DESIGN

In vivo animal study.

SETTING

Academic institution.

METHODS

Murine samples/measurements were obtained from mice that underwent chemomechanical injury with a wire brush and bleomycin. Human samples/measurements were obtained from iSGS patients. Anatomic, physiologic, and epithelial molecular data were collected using histology, human peak expiratory flow (PEF) and murine airway conductance, gene expression analysis with quantitative polymerase chain reaction, and protein analysis with quantitative immunohistochemistry.

RESULTS

Anatomic patterns of scars at the subglottis and proximal trachea seen in the murine model are similar to iSGS patients. Subglottic stenosis (SGS) mice had a decrease (P = .0194) in airway conductance compared to healthy controls, similar to a decrease (P = .0001) in predilation PEF versus postdilation in iSGS patients. There was decreased epithelial gene expression of E-cadherin (ECAD) (P < 0.01), occludin (OCLN) (P < .01), and cytokeratin-5 (CK5) (P < .05) and protein expression of ECAD (H/M: P < .001), OCLN (H: P < 0.05, M: P < .001), and CK5 (H: P < .001, M: P < .01) in murine SGS and iSGS versus controls.

CONCLUSION

The murine SGS model shows anatomic, physiologic, and molecular congruency with human iSGS, making it a reasonable model to investigate iSGS. The molecular similarities in epithelial barrier dysfunction suggest it may best be suited to explore epithelial mechanisms of iSGS and therapies directed at epithelial reconstitution. This model provides a foundation to collect data that will improve understanding of iSGS, and, ultimately, translate into more accurate animal models for future use.

Myeloid Phenotypes in Tracheostomy-Associated Granulation Tissue

OBJECTIVE(S)

Tracheostomy-associated granulation tissue is a common, recurrent problem occurring secondary to chronic mucosal irritation. Although granulation tissue is composed of predominantly innate immune cells, the phenotype of monocytes and macrophages in tracheostomy-associated granulation tissue is unknown. This study aims to define the myeloid cell population in granulation tissue secondary to tracheostomy.

METHODS

Granulation tissue biopsies were obtained from 8 patients with tracheostomy secondary to laryngotracheal stenosis. Cell type analysis was performed by flow cytometry and gene expression was measured by quantitative real-time polymerase chain reaction. These methods and immunohistochemistry were used to define the monocyte/macrophage population in granulation tissue and were compared to tracheal autopsy control specimens.

RESULTS

Flow cytometry demonstrated macrophages (CD45+CD11b+) and monocytes (CD45+FSClow SSClow ) represent 23.2 ± 6% of the granulation tissue cell population. The M2 phenotype (CD206) is present in 77 ± 11% of the macrophage population and increased compared to the M1 phenotype (p = 0.012). Classical monocytes (CD45+CD14high CD16low ) were increased in granulation tissue compared to controls (61.2 ± 7% and 30 ± 8.5%, p = 0.038). Eighty-five percent of macrophages expressed pro-inflammatory S100A8/A9 and 36 ± 4% of macrophages co-localized CD169, associated with tissue-resident macrophages. M2 gene expression (Arg1/CD206) was increased in granulation tissue (3.7 ± 0.4, p = 0.035 and 3.5 ± 0.5, p = 0.047) whereas M1 gene expression (CD80/CD86) was similar to controls (p = 0.64, p = 0.3). Immunohistochemistry of granulation tissue demonstrated increased cells co-localizing CD11b and CD206.

CONCLUSIONS

M2 macrophages are the dominant macrophage phenotype in tracheostomy-associated granulation tissue. The role of this cell type in promoting ongoing inflammation warrants future investigation to identify potential treatments for granulation tissue secondary to tracheostomy.

LEVEL OF EVIDENCE

3 Laryngoscope, 133:2346-2356, 2023.

Eye Tracking and Motion Data Predict Endoscopic Sinus Surgery Skill

OBJECTIVE

Endoscopic surgery has a considerable learning curve due to dissociation of the visual-motor axes, coupled with decreased tactile feedback and mobility. In particular, endoscopic sinus surgery (ESS) lacks objective skill assessment metrics to provide specific feedback to trainees. This study aims to identify summary metrics from eye tracking, endoscope motion, and tool motion to objectively assess surgeons' ESS skill.

METHODS

In this cross-sectional study, expert and novice surgeons performed ESS tasks of inserting an endoscope and tool into a cadaveric nose, touching an anatomical landmark, and withdrawing the endoscope and tool out of the nose. Tool and endoscope motion were collected using an electromagnetic tracker, and eye gaze was tracked using an infrared camera. Three expert surgeons provided binary assessments of low/high skill. 20 summary statistics were calculated for eye, tool, and endoscope motion and used in logistic regression models to predict surgical skill.

RESULTS

14 metrics (10 eye gaze, 2 tool motion, and 2 endoscope motion) were significantly different between surgeons with low and high skill. Models to predict skill for 6/9 ESS tasks had an AUC >0.95. A combined model of all tasks (AUC 0.95, PPV 0.93, NPV 0.89) included metrics from eye tracking data and endoscope motion, indicating that these metrics are transferable across tasks.

CONCLUSIONS

Eye gaze, endoscope, and tool motion data can provide an objective and accurate measurement of ESS surgical performance. Incorporation of these algorithmic techniques intraoperatively could allow for automated skill assessment for trainees learning endoscopic surgery.

LEVEL OF EVIDENCE

N/A Laryngoscope, 133:500-505, 2023.

Phenotypic Epithelial Changes in Laryngotracheal Stenosis

OBJECTIVE

Characterize and quantify epithelium in multiple etiologies of laryngotracheal stenosis (LTS) to better understand its role in pathogenesis.

STUDY DESIGN

Controlled in vitro cohort study.

METHODS

Endoscopic brush biopsy samples of both normal (non-scar) and scar were obtained in four patients with idiopathic subglottic stenosis (iSGS) and four patients with iatrogenic LTS (iLTS). mRNA expression of basal, ciliary, and secretory cell markers were evaluated using quantitative PCR. Cricotracheal resection tissue samples (n = 5 per group) were also collected, analyzed using quantitative immunohistochemistry, and compared with rapid autopsy tracheal samples.

RESULTS

Both iSGS and iLTS-scar epithelium had reduced epithelial thickness compared with non-scar control epithelium (P = .0009 and P = .0011, respectively). Basal cell gene and protein expression for cytokeratin 14 was increased in iSGS-scar epithelium compared with iLTS or controls. Immunohistochemical expression of ciliary tubulin alpha 1, but not gene expression, was reduced in both iSGS and iLTS-scar epithelium compared with controls (P = .0184 and P = .0125, respectively). Both iSGS and iLTS-scar had reductions in Mucin 5AC gene expression (P = .0007 and P = .0035, respectively), an epithelial goblet cell marker, with reductions in secretory cells histologically (P < .0001).

CONCLUSIONS

Compared with non-scar epithelium, the epithelium within iSGS and iLTS is morphologically abnormal. Although both iSGS and iLTS have reduced epithelial thickness, ciliary cells, and secretory cells, only iSGS had significant increases in pathological basal cell expression. These data suggest that the epithelium in iSGS and iLTS play a common role in the pathogenesis of fibrosis in these two etiologies of laryngotracheal stenosis.

SETTING

Tertiary referral center (2017-2020).

LEVEL OF EVIDENCE

NA Laryngoscope, 132:2194-2201, 2022.

Impact of Low-Volume, Low-Pressure Tracheostomy Cuffs on Acute Mucosal Injury in Swine

OBJECTIVE

Tapered low-volume, low-pressure (LVLP) cuffs have been introduced to improve sealing and reduce injury from tracheostomy and endotracheal intubation compared to traditional cylindrical high-volume, low-pressure (HVLP) cuffs. The objective of this study is to develop a swine model of tracheostomy injury and to compare live tissue response following LVLP and HVLP tracheostomy placement.

STUDY DESIGN

In vivo animal study.

SETTING

Academic institution.

METHODS

Swine underwent tracheostomy followed by placement of LVLP and HVLP tracheostomy cuffs at 30 cm H2O. After 24 and 48 hours, tracheal specimens underwent histopathological analysis including cilia, lamina propria and epithelial thickness, and mucosal injury score.

RESULTS

In all cuff contact areas, mean epithelial thickness for both tracheostomy cohorts was decreased compared to control epithelium at 24 and 48 hours (P < .01). HVLP proximal epithelium thickness was decreased at 24 and 48 hours relative to LVLP sections (P < .05). Lamina propria thickness in proximal LVLP sections was less than HVLP sections at 24 hours and 48 hours (P < .05). Mucosal injury score at areas of cuff contact was increased in tracheostomy cohorts relative to controls (P < .001), with HVLP injury score greater than LVLP at the proximal cuff (P < .05).

CONCLUSION

In a swine model, tracheostomy resulted in increased mucosal injury compared to normal tracheal mucosa. LVLP cuffs resulted in less injury than HVLP cuffs, with reduced mucosal inflammation and improved health of epithelium and lamina propria. The wider proximal LVLP cuff demonstrated improved mucosal health compared to the HVLP cylindrical cuff.

DescePrep Significantly Increases Descemet Membrane Endothelial Keratoplasty Processing Efficiency and Success Rate in Diabetic Human Donor Corneas in Comparison With Manual Dissection

PURPOSE

The purpose of this study was to compare the safety, efficacy, and efficiency of a Descemet membrane endothelial keratoplasty (DMEK) graft processing device, DescePrep, with a manual dissection technique through the measurement of tissue yield, processing time, and graft viability in nondiabetic and diabetic donor corneas.

METHODS

Nondiabetic (n = 20) and diabetic (n = 20) donor corneas were processed using DescePrep, which standardizes the liquid bubble technique. Nondiabetic (n = 20) and diabetic (n = 24) donor corneas were also processed through manual dissection. Corneas were stained, processed, and then evaluated for processing success rate and time. Randomly selected corneas (n = 5, each) were evaluated for cell viability using live/dead staining.

RESULTS

One hundred percent of nondiabetic and 95% of diabetic corneas were processed successfully with DescePrep in an average of 3.37 minutes. Ninety percent of nondiabetic and 50% of diabetic corneas were processed successfully with manual dissection in an average of 9.87 minutes. DescePrep had a significantly lower processing time ( P < 0.0001) and significantly higher success rate in comparison with manual dissection. DescePrep grafts had an average cell viability of 91.1% ± 3.3% in nondiabetic and 91.5% ± 2.4% in diabetic corneas. Grafts prepared with manual dissection had an average cell viability of 89.5% ± 5.8% in nondiabetic and 88.1% ± 4.3% in diabetic corneas.

CONCLUSIONS

DescePrep provides a more effective and efficient method of cornea preparation in comparison with the current standard, particularly in diabetic corneas, while providing comparable cell viability. Thus, DescePrep offers standardized DMEK processing that produces high-quality grafts at high yields, with the potential to expand access and improve the quality of DMEK graft preparation in a larger pool of donors.

Delayed Diagnosis of Idiopathic Subglottic Stenosis

OBJECTIVE

Idiopathic subglottic stenosis (iSGS) is a rare disease, causing life-threatening dyspnea secondary to scarring. Perhaps because it is rarely encountered, there is often a delay in diagnosing iSGS. The objective of this study is to characterize diagnostic delay of iSGS, factors that prolong delay, and its impact on iSGS patients.

STUDY DESIGN

Retrospective chart review.

METHODS

A retrospective chart review of 124 iSGS patients was performed. Times of symptom onset, presentation to otolaryngologist, diagnosis, imaging, pulmonary function testing (PFTs), surgeries, emergency department (ED) visits, and hospitalizations were recorded and univariate analyses were used to identify risk factors for delay.

RESULTS

The median total time to diagnosis from symptom onset was 24.5 months, with time to first presentation of 6.3 months and healthcare delay of 17.8 months. 54.8% of patients were diagnosed with asthma. Earlier presentation to otolaryngologist was associated with shorter healthcare delay and total time to diagnosis (rho = 0.75, rho = 0.99, P < .0001). Earlier CT imaging was correlated to shorter healthcare delay (rho = 0.84, P < .0001) and total time to diagnosis (rho = 0.74, P < .001), while earlier PFTs were correlated to shorter total time to diagnosis alone (rho = 0.71, P = .01). During evaluation, 10.5% (n = 17/124) of patients had ED visits and 13.7% (n = 13/124) patients were hospitalized. Before diagnosis, 7% (9/124) of patients underwent surgeries (including 3% (n = 4) undergoing tracheostomy) and 8% (n = 10) of patients required unplanned urgent endoscopic surgery that may have been avoided with earlier diagnosis.

CONCLUSION

iSGS diagnosis is frequently delayed, resulting in additional surgeries (including tracheostomy), ED visits, and hospitalizations. Further, patients' symptoms are commonly attributed to asthma. Earlier otolaryngologist evaluation, PFTs, and CT imaging may expedite iSGS diagnosis.

LEVEL OF EVIDENCE

4 Laryngoscope, 132:413-418, 2022.

Virtual reality simulation does not correlate with overall trainee robot-assisted laparoscopic hysterectomy performance

STUDY OBJECTIVE

While both simulator practice and intraoperative performance serve to inform surgical trainee training, the skill transfer from simulation to the intraoperative setting remains unclear. This study evaluates the correlation between trainee performance on virtual reality (VR) simulation and (1) overall intraoperative performance during robotic-assisted laparoscopic hysterectomy (RALH) procedures, and (2) suturing performance during vaginal cuff closure portion of the case.

DESIGN

Retrospective subgroup analysis of randomized controlled trial SETTING: Academic hospital PATIENTS: Patients with RALH (n=29) INTERVENTIONS: Gynecological trainees (n=21) performed simulation tasks using the da Vinci Skills Simulator on the day of surgery, prior to performing RALH. Attending surgeons assessed participants' intraoperative performance using Global Evaluative Assessment of Robotic Skills (GEARS). Performance of the vaginal cuff closure step was subsequently assessed using GEARS scoring of anonymized videos. Spearman's correlation was used to quantify the relationship between simulation and intraoperative performances.

MEASUREMENTS AND MAIN RESULTS

Trainees achieved a median intraoperative GEARS score of 18.5/30 (IQR:17-22) and a median total simulator score of 84.4/100 (IQR:78.1-87.5). More advanced residents exhibited worse overall simulator performance (median score 86.6/100 compared to 78.8/100, p=0.03) and similar intraoperative GEARS scores during overall RALH and vaginal cuff closure compared to less experienced trainees. Total simulation performance score was negatively correlated with GEARS Bimanual Dexterity (rho=-0.46, p=0.02) and Force Sensitivity subscores (rho=-0.39, p=0.05). There was no correlation between total GEARS intraoperative vaginal cuff closure scores and overall simulation performances; however, total Tubes simulation score was correlated with higher GEARS Force Sensitivity subscore (rho=0.73, p=0.048).

CONCLUSIONS

In this study, there was limited correlation between simulation score metrics and trainees' overall intraoperative performance. Furthermore, we identified that GEARS scores could not distinguish between similar trainee skill levels. These findings underscore the need to develop intraoperative assessment tools that can better discriminate different but similar skill levels.

Quantifying Viral Particle Aerosolization Risk During Tracheostomy Surgery and Tracheostomy Care

Importance

During respiratory disease outbreaks such as the COVID-19 pandemic, aerosol-generating procedures, including tracheostomy, are associated with the risk of viral transmission to health care workers.

Objective

To quantify particle aerosolization during tracheostomy surgery and tracheostomy care and to evaluate interventions that minimize the risk of viral particle exposure.

Design, Setting, and Participants

This comparative effectiveness study was conducted from August 2020 to January 2021 at a tertiary care academic institution. Aerosol generation was measured in real time with an optical particle counter during simulated (manikin) tracheostomy surgical and clinical conditions, including cough, airway nebulization, open suctioning, and electrocautery. Aerosol sampling was also performed during in vivo swine tracheostomy procedures (n = 4), with or without electrocautery. Fluorescent dye was used to visualize cough spread onto the surgical field during swine tracheostomy. Finally, 6 tracheostomy coverings were compared with no tracheostomy covering to quantify reduction in particle aerosolization.

Main Outcomes and Measures

Respirable aerosolized particle concentration.

Results

Cough, airway humidification, open suctioning, and electrocautery produced aerosol particles substantially above baseline. Compared with uncovered tracheostomy, decreased aerosolization was found with the use of tracheostomy coverings, including a cotton mask (73.8% [(95% CI, 63.0%-84.5%]; d = 3.8), polyester gaiter 79.5% [95% CI, 68.7%-90.3%]; d = 7.2), humidification mask (82.8% [95% CI, 72.0%-93.7%]; d = 8.6), heat moisture exchanger (HME) (91.0% [95% CI, 80.2%-101.7%]; d = 19.0), and surgical mask (89.9% [95% CI, 79.3%-100.6%]; d = 12.8). Simultaneous use of a surgical mask and HME decreased the particle concentration compared with either the HME (95% CI, 1.6%-12.3%; Cohen d = 1.2) or surgical mask (95% CI, 2.7%-13.2%; d = 1.9) used independently. Procedures performed with electrocautery increased total aerosolized particles by 1500 particles/m3 per 5-second interval (95% CI, 1380-1610 particles/m3 per 5-second interval; d = 1.8).

Conclusions and Relevance

The findings of this laboratory and animal comparative effectiveness study indicate that tracheostomy surgery and tracheostomy care are associated with significant aerosol generation, putting health care workers at risk for viral transmission of airborne diseases. Combined HME and surgical mask coverage of the tracheostomy was associated with decreased aerosolization, thereby reducing the risk of viral transmission to health care workers.

Addressing the MSICS learning curve: identification of instrument-holding techniques used by experienced surgeons

AIM

To identify instrument holding archetypes used by experienced surgeons in order to develop a universal language and set of validated techniques that can be utilized in manual small incision cataract surgery (MSICS) curricula.

METHODS

Experienced cataract surgeons performed five MSICS steps (scleral incision, scleral tunnel, side port, corneal tunnel, and capsulorhexis) in a wet lab to record surgeon hand positions. Images and videos were taken during each step to identify validated hand position archetypes.

RESULTS

For each MSICS step, one or two major archetypes and key modifying variables were observed, including tripod for scleral incision, tripod-thumb bottom for scleral tunnel, underhand-index to thumb grip for side port, index-contact tripod for corneal entry, and tripod-forceps for capsulorhexis. Key differences were noted in thumb placement and number of fingers supporting the instrument, and modifying variables included index finger curvature and amount of flexion.

CONCLUSION

Identification of optimal hand positions and development of a formal nomenclature has the potential to help trainees adopt hand positions in an informed manner, influence instrument design, and improve surgical outcomes.

Factors Affecting Dilation Interval in Patients With Granulomatosis With Polyangiitis-Associated Subglottic and Glottic Stenosis

OBJECTIVE

Subglottic stenosis (SGS) is a known complication of granulomatosis with polyangiitis (GPA). We investigated the impact of medical and surgical interventions on the surgical dilation interval and characterized patients with glottic involvement.

STUDY DESIGN

A retrospective chart review of patients with GPA-associated SGS was performed from 2010 to 2019.

SETTING

Tertiary academic medical center.

METHODS

The impact of medical and surgical interventions on dilation interval was assessed. The prevalence of glottic involvement was assessed, and clinical characteristics and outcomes were compared with patients without glottic involvement.

RESULTS

A total of 39 patients with GPA-associated SGS were analyzed. Dilation intervals in patients receiving leflunomide (n = 4; median, 484 days; 95% CI, 405-1099) were greater than in those not receiving leflunomide (median, 155 days; 95% CI, 48-305; P = .033). The surgical technique used did not affect dilation interval. Patients with glottic involvement (n = 13) had a greater incidence of dysphonia (13/13 vs 15/26 [58%], P = .007) and a shorter dilation interval with involvement (median, 91 days; interquartile range, 70-277) versus without involvement (median, 377 days; interquartile range, 175-1148; hazard ratio, 3.38; 95% CI, 2.26-5.05; P < .001). Of 13 patients, 8 (62%) did not have glottic involvement on first presentation.

CONCLUSION

Although GPA is classically thought to affect the subglottis, it also involves the glottis in a subset of patients. These patients have greater complaints of dysphonia and require more frequent surgery. Systemic therapy may increase dilation intervals. In this preliminary study, patients taking leflunomide demonstrated an improvement, highlighting the need for further study of immunosuppression regimens in the treatment of GPA-associated SGS.

Characterization of patient head motion in otologic surgery: Implications for TEES

PURPOSE

Middle ear disease is increasingly being managed via transcanal endoscopic ear surgery (TEES). A limitation of TEES is that it restricts the surgeon to single-handed dissection. One solution to this would be an endoscope holder to facilitate two-handed dissection. Current endoscope holders are stationary, and can cause potential damage from endoscope contact with the ossicles or ear canal if unintended head motion occurs from inadequate anesthetic. A dynamic device that could detect and react to patient motion would mitigate these concerns, but currently there is little formal characterization of the frequency, velocity and acceleration of unintended patient head motion during otologic procedures performed under general anesthesia. The present study aims to characterize intraoperative patient head motion kinematics during cases utilizing TEES.

MATERIALS AND METHODS

This is a prospective study of adults undergoing otologic procedures performed with general anesthesia and without paralysis. Head motion was characterized using a nine-axis inertial measurement unit (IMU), (LPMS-B2, Life Performance Research) mounted to each patient's forehead for the procedure duration.

RESULTS

Data was collected across 10 cases; 50% of patients were female and mean age was 50 ± 14 years. There was observed patient head motion in 40% of cases with maximum linear acceleration of 0.75 m/s² and angular velocity of 12.50 degrees/s.

CONCLUSIONS

Patient movement during otologic procedures was commonly observed, demonstrating the need for a dynamic holder to allow two-handed TEES. Results from this study are the first objective characterization of patient head motion kinematics during otologic procedures performed under general anesthesia.

MRI-guided percutaneous sclerotherapy of venous malformations: initial clinical experience using a 3T MRI system

PURPOSE

Venous malformations (VMs) are low-flow vascular anomalies that are commonly treated with image-guided percutaneous sclerotherapy. Although many VMs can be safely accessed and treated using ultrasonography and fluoroscopy, some lesions may be better treated with magnetic resonance imaging (MRI)-guided sclerotherapy. The aim of this study is to evaluate the feasibility, efficiency, and outcomes of MRI-guided sclerotherapy of VMs using a 3T MRI system.

METHODS

Six patients with VMs in the neck (n = 2), chest (n = 1), and extremities (n = 3) underwent sclerotherapy with 3T MRI guidance. Feasibility was assessed by calculating the technical success rate and procedural efficiency. Efficiency was evaluated by using planning, targeting, intervention, and total procedure times. Outcomes were assessed by measuring VM volumes before and after sclerotherapy, patient-reported pain scores, and occurrence of complications.

RESULTS

Technical success was achieved in all 6 procedures. There was a non-significant 30% decrease in mean VM volume after the procedure (P = .350). The procedure resulted in a decrease in mean pain score (on an 11-point scale) of 2.6 points (P = .003). After the procedure, 4 patients reported complete pain resolution, 1 reported partial pain resolution, and 1 reported no change in pain. Procedural efficiency was consistent with similar sclerotherapy procedures performed at our institution. There were no major or minor complications.

CONCLUSION

3T MRI guidance is feasible for percutaneous sclerotherapy of VMs, with promising initial technical success rates, procedural efficiency, and therapeutic outcomes without complications.

A Novel Intermediate Attachment to Reduce Contamination in Reusable Core Needle Biopsy Devices

One barrier to breast cancer diagnosis in low-resource settings is that devices for core needle biopsy (CNB) are either disposable and expensive, or reusable and susceptible to internal contamination. Through interviews with field workers and verification experiments, we identified that a common, commercially available, reusable CNB device allows contaminants to enter the driver chamber during firing, necessitating laborious cleaning of the entire device after every use. We introduce a novel CNB device attachment that eliminates this contamination mode and interfaces with existing commercial reusable drivers and low-cost disposable needles. This attachment repositions the driver–needle connection to the exterior of the driver, preventing retrograde flow of blood. Using an unmodified commercial CNB, we replicate chamber contamination by firing into a body fluid-mimicking glycerol solution. Prototypes were tested for their performance in eliminating this contamination. We tested the effectiveness of a cleaning procedure to reduce trace contamination by using a fluorescent dye and measuring the intensity of fluorescence after cleaning. The device's ability to reliably and consistently biopsy tissue with the novel attachment was evaluated using breast tissue models. In these tests, a reusable CNB with our attachment exhibited no measurable internal contamination, and maintained full biopsy functionality as measured by tissue sample weight and length. Minimizing internal device contamination would simplify the cleaning process for reusable biopsy devices. This would improve the accessibility of breast cancer biopsies in low- and middle-income countries (LMICs).