A Multicenter Retrospective Evaluation of the Clinical Performance and Safety of an Enhanced 16 Fr CryoDecompression Tube for Use in Liquid Nitrogen Spray Cryotherapy

Introduction: Endoscopic liquid nitrogen spray cryotherapy (LNSCT) is an established treatment modality for management of dysplastic Barrett’s esophagus (BE) and esophageal cancer (EC). Placement of an orogastric decompression tube (CDT) is required for active and passive venting of nitrogen gas generated during treatment. Currently available CDTs are limited by size (20 Fr) and soft, flexible material (16 Fr). An enhanced, fluoroscopically visible 16 Fr CDT was developed to maintain luminal patency and rigidity despite a smaller caliber. The aim of this study was to evaluate the performance and safety of this new, FDA-cleared CDT. Methods: This multicenter retrospective on-label case series was approved by central IRB. All adult patients with dysplastic BE or EC who underwent LNSCT using the enhanced CDT in February/March 2023 were included. Primary outcomes included ease of operation/use, rate of intraprocedural adverse events and rate of uninterrupted procedure completion (Figure 1). Results: A total of 28 patients (93% male, mean age 67.4 years) from 16 U.S. medical centers met inclusion criteria (Table 1). The most common indication was EC (20, 71.4%). There were 15 patients (57.7%) with a hiatal hernia and 18 patients (64.3%) with luminal stenosis; 3 (10.7%) had narrowing which prohibited endoscope passage. In 12 cases (42.9%), the endoscopist felt a 20Fr CDT could not have been used (due to luminal stenosis). A standard gastroscope was used for most cases (21, 75%). All patients had intraprocedural abdominal monitoring, with only 1 (3.6%) experiencing mild abdominal distension. All procedures were completed successfully without treatment interruption. Tube integrity was maintained in all patients (100%). Compared to the existing/older 16 Fr CDT, most providers rated insertion of this enhanced CDT as easier (24, 87.5%), with easier endoscope maneuverability (26, 92.9%). Conclusion: To date, LNSCT users have had to choose between ease of per-oral CDT insertion and maintenance of adequate decompression during treatment. These data suggest an enhanced 16 Fr CDT is safe, effective and easier to use than the existing (older) 16 Fr CDT. A smaller caliber CDT is especially useful to facilitate treatment in patients with advanced EC, where tumor bulk and luminal stenosis leads to dysphagia. When used in combination with an ultra-thin (5-6 mm diameter) gastroscope, this enhanced CDT could markedly increase the number of EC patients who can receive palliative LNSCT.Figure 1.: Images Demonstrating LNSCT console, 16Fr Enhanced Cryodecompression Tube and Procedure Images from a Patient with Advanced Esophageal Cancer who Underwent LNSCT Using the Enhanced CDT. 1a: LNSCT console/platform. 1b: Enhanced 16Fr CDT with close up view of fluoroscopically visible distal tip of the tube. 1c: Distal esophagus with advanced, lumen constricting esophageal tumor. 1d and 1e: Esophagus at beginning and end of LNSCT for esophageal tumor palliation, showing the spray catheter (white catheter) and enhanced 16Fr CDT (black arrow) in place. Table 1. - Demographic Data and Study Results Summary All Subjects (n = 28) Age (Years) n 28 Mean (SD) 67.4 (14.97) Median 71.0 Min, Max 30, 91 Gender, n (%) Male 26 (92.9%) Female 2 (7.1%) Race, n (%) African American 3 (10.7%) White 25 (89.3%) Procedure Indication, n (%) Benign 8 (28.6%) Malignant 20 (71.4%) Hiatal Hernia, n (%) Yes 15 (57.7%) No 11 (42.3%) Missing 2 Does Patient Have Luminal Stenosis, n (%) Yes 18 (64.3%) No 10 (35.7%) Allows Passage of Endoscope, n (%) Yes 25 (89.3%) No 3 (10.7%) Type of Gastroscope, n (%) Standard 21 (75.0%) Slim 7 (25.0%) Did Patient Receive Abdominal Monitoring, n (%) Yes 28 (100.0%) Did Patient Experience Abdominal Distension, n (%) Yes 1 (3.6%) No 27 (96.4%) Abdominal Distension Severity, n (%) n 1 Mild 1 (100.0%) Was Treatment Interrupted for Distension, n (%) No 28 (100.0%) Was Tube Integrity Maintained, n (%) Yes 28 (100.0%) Ease of Insertion of Enhanced CDT Compared to Existing CDT, n (%) Easier 24 (85.7%) N/A 1 (3.6%) Same 3 (10.7%) Scope Maneuverability Compared to Current 16Fr CDT, n (%) Easier 26 (92.9%) N/A 1 (3.6%) Same 1 (3.6%) Could a 20Fr CDT Have Been Used for This Case, n (%) Yes 16 (57.1%) No 12 (42.9%)