Use of infrared thermography to delineate temperature gradients and critical isotherms during catheter ablation with normal and half normal saline: Implications for safety and efficacy.

BACKGROUND: Radiofrequency (RF) ablation with half-normal saline (HNS) has shown promise as a bail-out strategy following failed ventricular tachycardia ablation using standard approaches. OBJECTIVE: To use a novel infrared thermal imaging (ITI) model to evaluate biophysical and lesion characteristics during RF ablation using normal saline (NS) and HNS irrigation. METHODS: Left ventricular strips of myocardium were excised from fresh porcine hearts. RF ablation was performed using an open-irrigated ablation catheter (Thermocool ST/SF) with NS (n = 75) and HNS (n = 75) irrigation using different power settings (40/50 W), RF durations (30/60 s), contact force of 10-15 g, and flow rate of 15 ml/min. RF lesions were recorded using an infrared thermal camera and border zone, lethal, 100° isotherms were matched with necrotic borders after 2% triphenyltetrazolium chloride staining. Lesion dimensions and isotherms (mm2 ) were measured. RESULTS: In total, 150 lesions were delivered. HNS lesions were deeper (6.4 ± 1.1 vs. 5.7 ±0.8 mm; p = .03), and larger in volume (633 ± 153 vs. 468 ± 107 mm3 ; p = .007) than NS lesions. Steam pops (SPs) occurred during 19/75 lesions (25%) in the NS group and 32/75 lesions (43%) in the HNS group (p = .34). Lethal (57.8 ± 6.5 vs. 36.0 ± 3.9 mm2 ; p = .001) and 100°C isotherm areas (16.9 ± 6.9 vs. 3.8 ± 4.2 mm2 ; p = .003) areas were larger and were reached earlier in the HNS group. CONCLUSIONS: RFA using HNS created larger lesions than NS irrigation but led to more frequent SPs. The presence of earlier lethal isotherms and temperature rises above 100°C on ITI suggest a potentially narrower therapeutic-safety window with HNS.

Histopathology of Recalcitrant Maxillary Sinusitis Necessitating Endoscopic Medial Maxillectomy.

OBJECTIVES: Endoscopic medial maxillectomy (EMM) is an effective intervention for patients with recalcitrant maxillary sinusitis after previous middle meatal antrostomy. The pathophysiology of refractory maxillary sinusitis is incompletely understood. We aim to identify trends in structured histopathology (SHP) to better understand how tissue architecture changes contribute to refractory sinusitis and impaired mucociliary clearance. METHODS: All patients who underwent EMM or standard maxillary antrostomy for recalcitrant maxillary sinusitis of various forms were included. Retrospective chart review was conducted to collect information on demographics, disease characteristics, comorbid conditions, culture data, and SHP reports. Chi-squared and logistic regression analyses were performed for SHP variables. RESULTS: Forty-one patients who underwent EMM and 464 patients who underwent maxillary antrostomy were included. On average, the EMM cohort was 10 years older (60.9 years vs. 51.1 years; p = 0.001) and more often had a history of prior sinus procedures (73.2% vs. 40.9%; p < 0.001). EMM patients had higher rates of fibrosis (34.1% vs. 15.1%, p = 0.002), and this remained statistically significant when controlling for prior sinus procedures and nasal polyposis (p = 0.001). Cultures positive for pseudomonas aeruginosa (38.2% vs. 5.6%, p < 0.001) and coagulase negative staphylococcus (47.1% vs. 23.5%, p = 0.003) were more prevalent in the EMM group. CONCLUSION: Fibrosis and bacterial infections with Pseudomonas and coagulase negative Staphylococcus were more prevalent in patients requiring EMM. This may contribute to the multifactorial etiology of impaired mucociliary clearance in patients with recalcitrant maxillary sinusitis. LEVEL OF EVIDENCE: 3 Laryngoscope, 134:2646-2652, 2024.

Middle ear adenoma: Cytohistologic features and differential diagnosis.

Middle ear adenomas are rare, low grade glandular neoplasms with epithelial and neuroendocrine components and with varying patterns of differentiation. Due to the rarity of this tumor, there is a dearth of publications detailing the cytological features. We herein review our institution's pathological database for cytological material between 1992 and 2022 for MEA specimens and discuss possible differential diagnoses based on clinical, pathological, and cytologic data and material.

Histopathologic Features of Chronic Rhinosinusitis in Diabetic Patients.

OBJECTIVE: To explore how diabetes mellitus impacts chronic rhinosinusitis clinically and on structured histopathology to provide insights on new potential chronic rhinosinusitis endotypes. STUDY DESIGN: Retrospective cohort study. SETTING: Tertiary academic center. METHODS: A retrospective study of chronic rhinosinusitis patients who underwent functional endoscopic sinus surgery from 2015 to 2020 was performed. Structured 13-variable histopathology reports were generated from intraoperative sinonasal specimens. These variables were compared against demographic factors, comorbidities, culture data, and preoperative Lund-Mackay and SNOT-22 scores using logistic regression. RESULTS: There were 411 patients, including 52 diabetics. Diabetes was associated with higher mean body mass index (34.9 vs 29.2; p < .001), age (57.8 vs 48.0; p < .001), and Gram-negative (40.2% vs 22.7%; p < .030) and coagulase-negative Staphylococcus (49.0% vs 28.5%; p = .008) culture rates. Black (23.1% vs 18.7%) and Hispanic (23.1% vs 8.6%) races were more common with diabetes (p = .026). Gender, smoking, polyp status, and Lund-Mackay and SNOT-22 scores did not differ between groups. Diabetics had more fungal elements (13.5% vs 3.3%, p = .018); no other histopathological differences were seen. When controlling for demographic variables and comorbidities, diabetes independently predicted the presence of fungal elements (HR 4.38, p = .018). CONCLUSION: Diabetic chronic rhinosinusitis patients demonstrated increased fungal elements on structured histopathology. Other histopathological features were unaffected by diabetes. These findings may have important implications on the medical and surgical management of diabetic chronic rhinosinusitis patients in which early fungal disease assessment is paramount.

Histopathology of Allergic Fungal Rhinosinusitis Versus Chronic Rhinosinusitis with Nasal Polyps.

OBJECTIVE: Structured histopathology (SHP) is a method of analyzing sinonasal tissue to characterize endotypes of chronic rhinosinusitis with nasal polyps (CRSwNP). Allergic fungal rhinosinusitis (AFRS) shares several features with certain endotypes of CRSwNP. Our objective was to compare the histopathology of AFRS and eosinophilic CRSwNP to further understand whether they are separate endotypes or disease entities altogether. METHODS: A retrospective review of AFRS and CRSwNP patients undergoing endoscopic sinus surgery was performed. Data were collected on demographics, comorbidities, subjective and objective severity scores, and 13-variable SHP reports. CRSwNP patients with >10 eosinophils per high-power field (eCRSwNP) were included. Chi-squared and t-tests were used for statistical analysis. RESULTS: A total of 29 AFRS and 108 eCRSwNP patients were identified. AFRS patients were younger and more often Black. Symptom severity scores (SNOT-22, Lund-MacKay, and Lund-Kennedy) were uniform between groups. AFRS patients had a higher rate of Charcot-Leyden crystals (41.4% vs. 10.2%; p < 0.001). Severe degree of inflammation, eosinophilic inflammatory predominance, eosinophil aggregates, subepithelial edema, and basement membrane thickening were common in both groups, and their rates were not statistically significantly different between groups. Metaplasia, ulceration, fibrosis, and hyperplastic/papillary change rates were low (<30%) and similar between groups. CONCLUSION: The SHP of eCRSwNP and AFRS are highly consistent, which suggests AFRS is a severe subtype of CRSwNP overall rather than a separate disease entity. This also lends credence to AFRS belonging on the endotypic spectrum of CRSwNP. LEVEL OF EVIDENCE: 3 Laryngoscope, 2023.

Variability in Depth of Invasion Measurements in Carcinomas of the Oral Cavity and the Effect on Pathologic Tumor Staging.

Depth of invasion (DOI) was added to the staging criteria for carcinoma of the lip and oral cavity in the 8th edition of the American Joint Committee on Cancer Staging Manual (AJCC8). However, there are multiple practical challenges to obtaining an accurate DOI measurement with limited data regarding interobserver variability in DOI measurement. The aim of this study was to investigate interobserver variability in DOI measurement and its effect on tumor stage. We performed an electronic medical record search for excisions of squamous cell carcinoma of the oral cavity between January 1, 2010 and December 25, 2017. All slides containing significant tumor were selected for independent blinded DOI measurement by four head and neck pathologists per AJCC8 guidelines. Pathologic stage was assigned in conjunction with reported tumor greatest dimension. Observers recorded the slide used for measurement and potential issues limiting assessment of DOI. Results were compared for reproducibility in DOI and tumor stage using intraclass correlation coefficient (ICC) analysis. A total of 167 cases of oral squamous cell carcinoma with available slides were included. The ICC score for DOI between observers was 0.91339 (> 0.9 considered excellent). Only 7.2% of cases had uniform DOI amongst observers. Increasing overall tumor size and average DOI correlated with increasing range in DOI amongst observers. Differences in DOI resulted in differences in pathologic tumor staging (pT) for 15% of tumors. Use of different slides for DOI measurements was significantly associated with different pT staging. In contrast, ulceration and exophytic growth did not correlate with higher DOI or pT variability. Despite the excellent ICC score, differences in DOI measurement resulted in variable pT staging for a considerable number of cases. We therefore recommend consensus for DOI in at least some cases in which potential differences in DOI could alter pT stage assignment.

Müllerian Remnant Cyst as a Cause of Acute Abdomen in a Female Patient with Müllerian Agenesis: Radiologic and Pathologic Findings.

We report a case of a 17-year-old female with Müllerian agenesis who presented with right sided abdominal pain clinically suspicious for acute appendicitis. Multimodality imaging workup revealed a heterogeneous cystic right upper quadrant mass with surrounding fluid and inflammatory changes. Surgical resection of this mass was performed and a histopathologic diagnosis of a hemorrhagic Müllerian remnant cyst was made, which to the best of our knowledge has never been described in a patient with Müllerian agenesis.