Table 1.
A summary of the studies in the esophageal temperature monitoring probes
| Study | Year | Type | RCT | Group 1 - type of LET probe | Group 1, n | Group 2 – control, n | Ablation method | Posterior settings | Total in study, n | Total in group 1 that had OGD, n | Group 1 positive EDEL results, n (%) | Group 2 positive EDEL results, n (%) | Study outcomes | Time of endoscopy (if known), days | Adverse event from LET probe |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Di Biase et al | 2009 | RCT but randomization for GA vs LA. All had LET monitoring probes | 1 - GA vs LA | ER400-9, Smiths Medical ASD Inc, Rockland, MA. Single-sensor probe. | 50 | NA | RF | 35 W; 20 seconds | 50 | 50 | 13 (26%) | NA | GA increased risk of EDEL injury compared to LA | 1 - capsule | |
| Ahmed et al | 2009 | Prospective single-arm | NA | Vital Temp, Vital Signs Colorado Inc (Single thermocouple) | 67 | NA | Cryo | Cryo | 67 | 35 | 6 (17.1%) | NA | Cryoballoon ablation can cause significant LET decreases, resulting in reversible esophageal ulcerations in 17% of patients | 1 | |
| Di Biase et al | 2010 | Prospective single arm study | NA | ER400–9 Smiths Medical ASD, Inc, Rockland, MA | 88 | NA | RF | 35 W; 20 seconds | 88 | 88 | 15 (17%) | NA | Capsule endoscopy can be used to detect EDELs | 1 | |
| Sause et al | 2010 | Prospective single-arm | NA | Esotherm, FIAB, Florence, Italy (7F, 5 electrodes) | 184 | NA | RF | 30 W; 20 seconds | 184 | 184 | 3 (1.63%) | NA | Temperature limit of 40 degrees was associated with lowest incidence of EDEL at the time the study was published | 1 | |
| Halm et al | 2010 | Prospective single-arm | NA | Not specified | 185 | NA | RF | Not known | 185 | 185 | 27 (14.6%) | NA | Localized esophageal ulcer-like lesion is a frequent event after left atrial catheter ablation and can be found in patients whose intraluminal temperature has reached at least 41 degrees | Not known | |
| Leite et al | 2011 | Prospective single-arm | NA | EPT Blazer II temperature ablation catheter, Boston Scientific, Natick, MA | 45 | NA | RF | 25 W; if LET increased by 2 degrees from baseline then stop ablation | 45 | 45 | 0 | NA | A deflectable LET probe and stopping ablation after a 2-degree rise in LET may reduce esophageal injury | 1–2 | |
| Contreras et al | 2011 | Prospective single-arm | NA | Acoustascope, Smiths Medical ASD, Inc, Keene, NH | 219 | NA | RF | 25 W; 20 seconds | 219 | 82 | 22 (26.8%) | NA | The macroscopic severity of esophageal lesions detected on endoscopy the day after RF ablation can predict the time to resolution, with severe, deep ulcerations taking the longest to heal | 1, 10, 14 days until healed | |
| Furnkranz et al | 2013 | Prospective single-arm | NA | Sensitherm, St Jude Medical, Inc, St Paul, MN (3 thermocouples) | 32 | NA | Cryo | Cryo | 32 | 32 | 6 (18.75%) | NA | Second-generation 28 mm CB PVI is associated with significant esophageal cooling, resulting in lesion formation in 19% of the patients. LET measurement accurately predicts lesion formation. | 1–3 | |
| Knopp et al | 2014 | Prospective single-arm | NA | Sensitherm, St Jude Medical, Inc, St Paul, MN | 425 | NA | RF | 30 W | 425 | 425 | 47 (11%) | NA | Thermal injury including gastroparesis was common after AF ablation | 1–3 | |
| Furnkranz et al | 2014 | Prospective single-arm | NA | Sensitherm, St Jude Medical, Inc, St Paul, MN | 94 | NA | Cryo | Cryo | 94 | 32 | 6 (18.8%) | NA | Titration of CB PVI depending on LET temp fall to -15 degrees can reduce EDEL | Within 3 days | |
| Metzner et al | 2014 | Prospective single-arm | NA | Sensitherm, St Jude Medical, Inc, St Paul, MN | 50 | NA | Cryo | Cryo | 50 | 50 | 6 (12%) | NA | Using the second-generation 28-mm CB, EDEL was detected in 6 of 50 (12%) patients. All mucosal lesions were in the healing process on repeat EGD. | 2 | |
| Muller P et al | 2015 | Prospective double-arm – observational - nonrandomized | NA | Sensitherm, FIAB, Firenze, Italy (7F, 5 electrodes) | 40 | 40 | RF | 25 W | 80 | 40 | 12 (30%) | 1 (2.5%) | Use of temperature probes the only independent predictor of development of EDEL: Use of temperature probes was a risk factor for EDEL during AF ablation in this study | 2 | |
| Halbfass et al | 2017 | Observational | NA | S-Cath TM (Circa Scientific, LLC, Englewood, CO); esophageal temperature probe with insulated thermocouples: s-shaped and 12 electrodes | 40 | 40 | RF | 25 W | 80 | 40 | 3 (7.5%) | 4 (10%) | No reduction in EDELs with use of LET | 1–4 | |
| Deneke et al | 2018 | Prospective single-arm | NA | IRTS, Securus Medical Group, Inc, Cleveland, OH; 9F esophageal catheter connected to an external infrared detector | 63 | NA | RF | 25 W; 20 seconds; 5–20 g of contact force | 63 | 63 | 12 (19%) | NA | Peak temperature rise was associated with EDELs | 1 | |
| Daly et al | 2018 | Prospective single-arm | NA | IRTS, Securus Medical Group, Inc, Cleveland, OH | 16 | NA | RF | 20 W | 16 | 16 | 12.5 (78.1%) | NA | Infrared thermography provided dynamic, high-resolution mapping of esophageal temperatures during cardiac ablation. Esophageal thermal injury occurred with temperatures >50°C and was associated with large spatiotemporal gradients. | 1–2 | |
| Schoene et al | 2020 | RCT | 1 | Sensitherm, St Jude Medical, Inc, St Paul, MN | 90 | 90 | RF | 25–30 W | 180 | 90 | 10 (11.1%) | 8 (8.9%) | The Sensitherm LET probe does not affect the probability of developing EDEL | Within 3 days | |
| Chen S et al | 2020 | Prospective single-arm | NA | S-Cath TM (Circa Scientific, LLC, Englewood, CO) | 122 | NA | RF - AI-HP | 50 W/400 AI | 122 | 57 | 2 (3.5%) | NA | AI-HP ablation is associated with low incidence of EDELs; esophageal temperature probe monitoring was in use in these cases | 1 | |
| Meininghaus et al | 2021 | RCT | 1 | S-Cath TM (Circa Scientific, LLC, Englewood, CO) | 44 | 42 | RF | 25 W | 86 | 44 | 6 (13.6%) | 2 (4.8%) | LET monitoring does not prevent EDELs; temperatures >42 degrees were associated with increased likelihood of mucosal lesions | Within 3 days | 4 cases of epistaxis |
AF = atrial fibrillation; AI-HP = ablation index-high power; CB = cryoballoon; Cryo = cryoablation; EDEL = endoscopically detected esophageal lesion; EGD = esophago-gastroduodenoscopy; GA = general anaesthesia; LA = local anaesthesia; LET = luminal esophageal temperature; NA = not available; OGD = osophago-gastroduodenoscopy; PVI = pulmonary vein isolation; RCT = randomized controlled trial; RF = radiofrequency.