Gutierrez‐Gallegos, Paola

ABSTRACT Airway perforation is a potentially lethal complication from tracheal or mediastinal malignancies that require complex management. Advanced thyroid cancer is known to have high morbidity, and patients with tracheal metastatic lesions are vulnerable to injury. Therapeutic management typically comprises a combination of surgical and nonoperative treatment modalities, whose adverse effects can lead to significant airway injury. We present the case of a 67‐year‐old man with papillary thyroid carcinoma who developed a tracheocutaneous fistula following proton beam therapy and chemotherapy for metastatic disease. Airway repair and recanalization were successfully achieved through a combined surgical and bronchoscopic approach.

Abstract Rationale Pulmonary hypertension (PH) develops in up to 50% of patients with advanced interstitial lung disease (ILD) and is associated with increased morbidity, mortality, and impaired quality of life. Early recognition is essential, as available therapy for ILD-PH has been shown to improve outcomes. Identifying physiologic markers of PH may facilitate earlier referral for right heart catheterization (RHC) and initiation of targeted treatment. Thus, this study aimed to (1) compare functional parameters between ILD patients with and without RHC-confirmed PH, and (2) assess the applicability of previously proposed ILD-PH screening criteria. Methods We retrospectively analyzed ILD transplant candidates with available pre-transplant pulmonary function tests (FVC%, DLCO%), echocardiographic right-ventricular systolic pressure (RVSP), six-minute walk distance (6MWD) with oxygen requirement, and RHC data. PH was defined according to the 2022 ESC/ERS criteria. Functional parameters were compared between patients with and without PH. Among those without a prior PH diagnosis, screening thresholds derived from previously published tools were applied (RVSP ≥ 35 mmHg, DLCO < 40%, FVC/DLCO > 1.6, 6MWD < 350 m, or oxygen use during 6MWD). Results Of 107 ILD patients evaluated, 90 had complete RHC data (48 ILD-PH, 42 ILD without PH). Group comparisons are summarized in Table 1. Patients with PH had lower DLCO% (median 18.5 [11.5-26.7] vs 26.5 [20.0-34.7], p = 0.08), higher FVC/DLCO ratios (2.68 [2.1-3.4] vs 1.7 [1.4-2.6], p = 0.08), and higher RVSP (55 [39.7-63.2] vs 39.5 [29-48] mmHg, p = 0.002). Oxygen requirement during 6MWD was more frequent in ILD-PH (79.2% vs 61.9%, p = 0.08). Among patients with PH, 38 (79.16%) had no formal diagnosis prior to pre-transplant RHC. Of these cases, all (100%) met ≥3 screening criteria, most commonly DLCO < 40% (n = 38, 100%), FVC/DLCO > 1.6 (n = 37, 97.3%), and 6MWD < 350 m (n = 33, 86.8%). Additionally, 32 patients (84.21%) met ≥4 criteria and 8 (21.05%) met all five criteria. Conclusion In ILD transplant candidates, patients with PH had worse functional profiles when compared to those without PH, and nearly 80% of PH cases were previously undiagnosed. Systematic application of validated PH screening tools in ILD populations may facilitate earlier recognition, potentially improving patient outcomes. This abstract is funded by: None

Abstract Introduction VACTERL is an uncommon association of congenital anomalies that stands for vertebral defects, anal atresia, cardiac defects, tracheoesophageal fistula, renal anomalies, and limb abnormalities. In addition to these classical features, patients may present with airway abnormalities such as bronchial stenosis or bronchomalacia, which can lead to significant respiratory compromise. Severe bronchial stenosis is usually treated with open airway reconstruction or lung transplantation; however, this is associated with substantial risks, especially in patients with complicated congenital conditions. Interventional bronchoscopic techniques, such as paclitaxel-coated balloon dilatation, allow a less invasive alternative for restoring airway patency and reducing restenosis. We describe the case of a patient with VACTERL association and severe bronchial stenosis successfully treated with serial paclitaxel-coated balloon dilatations, avoiding the need for lung transplantation. Case description A 27-year-old male with VACTERL association presented with symptomatic left mainstem bronchial stenosis and complete right lung collapse. Bronchoscopic intervention was performed over lung transplantation because of the patient’s young age and high surgical risk. It revealed complete fibrotic obstruction of the right main bronchus and proximal stenosis of the left mainstem bronchus, measuring approximately 5-6 mm in diameter. Performing paclitaxel-coated balloon dilation showed progressive airway enlargement and clinical improvement. Under bronchoscopic guidance using a drug-coated balloon (diameter 8-10 mm, length 40 mm), which was placed in the narrowed segment and inflated for 2 minutes to expand the airway and deliver paclitaxel locally, thereby inhibiting cell proliferation and scar tissue formation. Subsequent follow-ups showed that the left mainstem bronchus diameter increased to 8-9 mm, with improvement in the airway patency and respiratory function, without any significant complications. Discussion Although the use of paclitaxel-coated balloon dilation for bronchial stenosis is still limited, this case illustrates its potential benefits as an adjunctive interventional therapy in patients with VACTERL association. The serial dilatations resulted in a progressive, sustained increase in airway diameter, from an initial 5-6 mm to approximately 8-9 mm at final follow-up in our patient (Figure 1). Compared with lung transplant, this intervention offers lower complication rates and the avoidance of chronic graft rejection and immunological complications, which are particularly relevant for young patients. This case report shows the potential of paclitaxel-coated balloon dilation as a safe, effective, and minimally invasive therapeutic option for managing bronchial stenosis in patients with complicated congenital disorders. This abstract is funded by: None

Abstract Introduction The diagnosis of fungal lung infections remains challenging as standard tests, such as bronchoalveolar lavage (BAL) antigen testing, often yield variable or inconclusive results. These limitations can delay appropriate therapy and may require additional tissue sampling for definitive diagnosis. Robotic-assisted bronchoscopy (RAB) biopsy has been primarily used as a minimally invasive technique for assessing suspicious peripheral pulmonary lesions (PPL). This case series highlights the diagnostic utility of RAB for identifying fungal infections within PPL when conventional BAL antigen analysis is non-diagnostic. Case Description Four patients with suspected infectious or malignant PPL underwent RAB-guided biopsy for diagnostic clarification, all yielding histopathologic confirmation of fungal disease. The first, a 73-year-old bilateral lung-transplant recipient with hemoptysis, had a negative BAL Aspergillus antigen despite RAB biopsy confirming Aspergillus infection. Similarly, a second 73-year-old man with chronic obstructive pulmonary disease (COPD) and esophageal adenocarcinoma had a negative BAL antigen, while RAB biopsy of bilateral cavitary lesions confirmed Aspergillus. Additionally, a 39-year-old woman with a nodule being evaluated for malignancy, had negative BAL Histoplasma antigen and PCR, whereas RAB biopsy confirmed Histoplasma capsulatum. In contrast, a 56-year-old woman with a right-lower-lobe nodule had a positive BAL Aspergillus antigen that aligned with the histopathologic biopsy findings. Discussion BAL-based antigen testing demonstrates variable diagnostic accuracy in fungal lung disease. Reported sensitivities for Aspergillus detection are typically high in meta-analysis, approximately 80%-90%, but clinical performance in the immunocompromised or high-risk patients is often substantially lower. Similarly, while BAL antigen testing for Histoplasma performs well in disseminated infections, it often fails to detect localized pulmonary disease. In this series, three out of four patients had negative BAL results in the presence of histopathologic confirmation of fungal infection. While current guidelines consider BAL positivity supportive of a “probable” diagnosis, tissue histopathology remains the gold standard for a “proven” infection. These findings emphasize the value and capability of RAB in obtaining direct tissue confirmation when conventional testing, such as BAL antigen analysis, is non-diagnostic. Conclusion RAB-guided biopsy of PPLs offers the opportunity for histopathologic confirmation of fungal infection when BAL testing is non-diagnostic. This approach can enhance upfront diagnostic yield in patients with suspected fungal pulmonary infections, avoiding delays in diagnosis and treatment initiation. This abstract is funded by: None

ABSTRACTAlthough current treatment strategies for nonmalignant airway stenosis may offer short‐term relief, their effectiveness is limited by high recurrence rates, often requiring additional procedures. While paclitaxel‐coated balloons (PCB) have demonstrated effectiveness in treating stenosis across various vascular and nonvascular conditions, their evidence in recurrent airway stenosis remains limited. Here, we present the case of a 35‐year‐old female with bronchial stenosis who underwent multiple bronchoscopic interventions, all of which were complicated by restenosis. Following the addition of a PCB to the therapeutic regimen, the patient achieved sustained airway patency.