510(k) · Cleared
Recalled · Class II · 2024Ultraflex Esophageal NG Stent System; WallFlex Esophageal Stent System
Data to Oct 25, 2026 (FDA decisions) Oct 12, 2026 (recalls) Sep 30, 2026 (MAUDE) refreshed weekly
Boston Scientific · ESW Prosthesis, Esophageal
Cleared on Apr 29, 2024 as substantially equivalent to K130004 (Boston Scientific Corporation, 2013) and 1 other predicate after a 137-day review. Its family tree reaches back 9 generations to 2001. 1 later device descends from it. It has been recalled 22 times.
- Decided
- Apr 29, 2024
- Review
- 137 days
- Class
- Class II
- Product code
- ESW
- Recalls
- 22
- Predicates
- 2
Its longest line of descent runs back 9 generations to K003173 (2001). 33 ancestors in all, the oldest K894380 (1989). 1 later device descends from it, 1 citing it directly.
- Root · 9 generations backK003173 Aspire Covered Stent and Delivery CatheterVascular Architects, Inc. · 2001
- 5 generations between
- 3 generations backK083625 Aero DV Tracheobronchial Stent SystemAlveolus, Inc. · 2009
- 2 generations backK121048 Ultraflex Tracheobronchial Stent System- Sterile UncoveredBoston Scientific Corp · 2012
- 1 generation backK130004 Ultraflex Esophageal NG Stent SystemBoston Scientific Corporation · 2013
- This deviceK233939 Ultraflex Esophageal NG Stent System; WallFlex Esophageal Stent SystemBoston Scientific · 2024
- Descendant · cites it directly · 0 of its ownK261978 WallFlex Esophageal Stent System;Agile Esophageal Over-the-Wire…Boston Scientific Corporation · 2026
Show all 9 generations
- Root · 9 generations backK003173 Aspire Covered Stent and Delivery CatheterVascular Architects, Inc. · 2001
- 8 generations backK012544 Vascular Architects Aspire Covered Stent and Controlled Expansion…Vascular Architects, Inc. · 2001
- 7 generations backK030947 Alveolus Inc., TB-STS Tracheobronchial Stent SystemAlveolus, Inc. · 2003
- 6 generations backK033053 Alveolus, TB-STS Tracheobronchial Stent SystemAlveolus, Inc. · 2004
- 5 generations backK062511 Aero Tracheobronchial Stent System, Model 90129-2XXAlveolus, Inc. · 2007
- 4 generations backK082284 Aero Tracheobronchial Stent Technology SystemAlveolus, Inc. · 2008
- 3 generations backK083625 Aero DV Tracheobronchial Stent SystemAlveolus, Inc. · 2009
- 2 generations backK121048 Ultraflex Tracheobronchial Stent System- Sterile UncoveredBoston Scientific Corp · 2012
- 1 generation backK130004 Ultraflex Esophageal NG Stent SystemBoston Scientific Corporation · 2013
- This deviceK233939 Ultraflex Esophageal NG Stent System; WallFlex Esophageal Stent SystemBoston Scientific · 2024
Most influential descendants
Showing 1 of 1 · See all- K261978WallFlex Esophageal Stent System;Agile Esophageal Over-the-Wire (OTW) Stent SystemBoston Scientific Corporation · 2026 · cites it directly0descendants
View FIG. 1 as a table
Line of descent and top descendants
| Generation | Number | Device | Applicant | Decided | Recalls |
|---|---|---|---|---|---|
| −9 | K003173 | Aspire Covered Stent and Delivery Catheter | Vascular Architects, Inc. | 2001 | — |
| −8 | K012544 | Vascular Architects Aspire Covered Stent and Controlled Expansion Delivery… | Vascular Architects, Inc. | 2001 | — |
| −7 | K030947 | Alveolus Inc., TB-STS Tracheobronchial Stent System | Alveolus, Inc. | 2003 | — |
| −6 | K033053 | Alveolus, TB-STS Tracheobronchial Stent System | Alveolus, Inc. | 2004 | — |
| −5 | K062511 | Aero Tracheobronchial Stent System, Model 90129-2XX | Alveolus, Inc. | 2007 | — |
| −4 | K082284 | Aero Tracheobronchial Stent Technology System | Alveolus, Inc. | 2008 | — |
| −3 | K083625 | Aero DV Tracheobronchial Stent System | Alveolus, Inc. | 2009 | — |
| −2 | K121048 | Ultraflex Tracheobronchial Stent System- Sterile Uncovered | Boston Scientific Corp | 2012 | — |
| −1 | K130004 | Ultraflex Esophageal NG Stent System | Boston Scientific Corporation | 2013 | — |
| 0 (this device) | K233939 | Ultraflex Esophageal NG Stent System; WallFlex Esophageal Stent System | Boston Scientific | 2024 | — |
| +1 | K261978 | WallFlex Esophageal Stent System;Agile Esophageal Over-the-Wire (OTW) Stent… | Boston Scientific Corporation | 2026 | — |
Other ancestors by year cleared
| Year cleared | Devices | With a Class I recall |
|---|---|---|
| 1989 | 1 | 0 |
| 1994 | 2 | 0 |
| 1995 | 1 | 0 |
| 1996 | 2 | 0 |
| 1997 | 2 | 0 |
| 2000 | 1 | 0 |
| 2001 | 3 | 0 |
| 2003 | 3 | 0 |
| 2004 | 2 | 0 |
| 2005 | 1 | 0 |
| 2007 | 1 | 0 |
| 2008 | 2 | 0 |
| 2009 | 2 | 0 |
| 2012 | 1 | 0 |
Descendants by year cleared
| Year cleared | Devices | With a Class I recall |
|---|---|---|
| 2026 | 1 | 0 |
Sources: FDA 510(k) database (decision fields), the FDA summary (predicates and indications), FDA recall and enforcement reports, and MAUDE; processed by 510(k) Report. Verify on FDA.gov · Methodology and accuracy.
Planning a device in ESW? A 510(k) Report weighs predicate choices, recall history and review times for a new device like this one.
Top candidate predicates for a new ESW device
- #1 K261978 WallFlex Esophageal Stent System;Agile…score 15.2 · 13 generations · no Class I recall
- #2 Held for the reportin the report
- #3 Held for the reportin the report
What was it cleared against? (2)
Devices the submitter claimed this one is substantially equivalent to (*), and reference devices cited for a specific test or feature (†), as written in the FDA summary.
| Type | Number | Device | Decided |
|---|---|---|---|
| * | K130004 | Ultraflex Esophageal NG Stent System | 2013 |
| * | K091510 | Wallflex Esophageal Fully Covered Stent System, Models M00516700, M00516710, M00516720…Summary page 6…e substantially equivalent to the previously cleared and currently marketed predicate Ultraflex Esophageal Stent System (Kl 30004) and Wall Flex Esophageal Stent System (K091510), respectively. The proposed Ultraflex Esophageal Stent System and Wall Flex Esophageal Stent System are identical to the predic… | 2009 |
What descends from it? (1)
1 later device cites it directly; ranked here by how many devices descend from each in turn.
| Number | Device | Decided | Descendants |
|---|---|---|---|
| K261978 | WallFlex Esophageal Stent System;Agile Esophageal Over-the-Wire (OTW) Stent System | 2026 | 0 |
Has anything in its family been recalled? (0 Class I)
Recalls of this device
| Date | Class | Recall | Root cause | Reason |
|---|---|---|---|---|
| Aug 1, 2024 | Class II | Z-3270-2024 | Process control | WallFlexTM Esophageal Stent System and AgileTM Esophageal Over the Wire (OTW) Stent System due to the potential for delivery catheter tip detachment. |
| Aug 1, 2024 | Class II | Z-3267-2024 | Process control | WallFlexTM Esophageal Stent System and AgileTM Esophageal Over the Wire (OTW) Stent System due to the potential for delivery catheter tip detachment. |
| Aug 1, 2024 | Class II | Z-3266-2024 | Process control | WallFlexTM Esophageal Stent System and AgileTM Esophageal Over the Wire (OTW) Stent System due to the potential for delivery catheter tip detachment. |
| Aug 1, 2024 | Class II | Z-3278-2024 | Process control | WallFlexTM Esophageal Stent System and AgileTM Esophageal Over the Wire (OTW) Stent System due to the potential for delivery catheter tip detachment. |
| Aug 1, 2024 | Class II | Z-3272-2024 | Process control | WallFlexTM Esophageal Stent System and AgileTM Esophageal Over the Wire (OTW) Stent System due to the potential for delivery catheter tip detachment. |
| Aug 1, 2024 | Class II | Z-3286-2024 | Process control | WallFlexTM Esophageal Stent System and AgileTM Esophageal Over the Wire (OTW) Stent System due to the potential for delivery catheter tip detachment. |
| Aug 1, 2024 | Class II | Z-3282-2024 | Process control | WallFlexTM Esophageal Stent System and AgileTM Esophageal Over the Wire (OTW) Stent System due to the potential for delivery catheter tip detachment. |
| Aug 1, 2024 | Class II | Z-3279-2024 | Process control | WallFlexTM Esophageal Stent System and AgileTM Esophageal Over the Wire (OTW) Stent System due to the potential for delivery catheter tip detachment. |
| Aug 1, 2024 | Class II | Z-3280-2024 | Process control | WallFlexTM Esophageal Stent System and AgileTM Esophageal Over the Wire (OTW) Stent System due to the potential for delivery catheter tip detachment. |
| Aug 1, 2024 | Class II | Z-3277-2024 | Process control | WallFlexTM Esophageal Stent System and AgileTM Esophageal Over the Wire (OTW) Stent System due to the potential for delivery catheter tip detachment. |
| Aug 1, 2024 | Class II | Z-3281-2024 | Process control | WallFlexTM Esophageal Stent System and AgileTM Esophageal Over the Wire (OTW) Stent System due to the potential for delivery catheter tip detachment. |
| Aug 1, 2024 | Class II | Z-3285-2024 | Process control | WallFlexTM Esophageal Stent System and AgileTM Esophageal Over the Wire (OTW) Stent System due to the potential for delivery catheter tip detachment. |
| Aug 1, 2024 | Class II | Z-3271-2024 | Process control | WallFlexTM Esophageal Stent System and AgileTM Esophageal Over the Wire (OTW) Stent System due to the potential for delivery catheter tip detachment. |
| Aug 1, 2024 | Class II | Z-3275-2024 | Process control | WallFlexTM Esophageal Stent System and AgileTM Esophageal Over the Wire (OTW) Stent System due to the potential for delivery catheter tip detachment. |
| Aug 1, 2024 | Class II | Z-3283-2024 | Process control | WallFlexTM Esophageal Stent System and AgileTM Esophageal Over the Wire (OTW) Stent System due to the potential for delivery catheter tip detachment. |
| Aug 1, 2024 | Class II | Z-3284-2024 | Process control | WallFlexTM Esophageal Stent System and AgileTM Esophageal Over the Wire (OTW) Stent System due to the potential for delivery catheter tip detachment. |
| Aug 1, 2024 | Class II | Z-3265-2024 | Process control | WallFlexTM Esophageal Stent System and AgileTM Esophageal Over the Wire (OTW) Stent System due to the potential for delivery catheter tip detachment. |
| Aug 1, 2024 | Class II | Z-3276-2024 | Process control | WallFlexTM Esophageal Stent System and AgileTM Esophageal Over the Wire (OTW) Stent System due to the potential for delivery catheter tip detachment. |
| Aug 1, 2024 | Class II | Z-3274-2024 | Process control | WallFlexTM Esophageal Stent System and AgileTM Esophageal Over the Wire (OTW) Stent System due to the potential for delivery catheter tip detachment. |
| Aug 1, 2024 | Class II | Z-3269-2024 | Process control | WallFlexTM Esophageal Stent System and AgileTM Esophageal Over the Wire (OTW) Stent System due to the potential for delivery catheter tip detachment. |
| Aug 1, 2024 | Class II | Z-3273-2024 | Process control | WallFlexTM Esophageal Stent System and AgileTM Esophageal Over the Wire (OTW) Stent System due to the potential for delivery catheter tip detachment. |
| Aug 1, 2024 | Class II | Z-3268-2024 | Process control | WallFlexTM Esophageal Stent System and AgileTM Esophageal Over the Wire (OTW) Stent System due to the potential for delivery catheter tip detachment. |
The 5 latest of 22 recalls; the web page lists all.
No ancestor or descendant has a Class I recall.
What does this lineage say?
- The line of descent spans 23 years and passes through 5 companies; a new generation was cleared every 1.5 years on median.
- 5 of the 33 ancestors have a recall of any class.
- Of its descendants, K261978 (Boston Scientific Corporation, 2026) has gone furthest, with 0 descendants of its own.
How does its category compare?
All ESW devicesESW Prosthesis, Esophageal: FDA decisions, review times, recalls and adverse event reports over 20 years. 2024, this device’s year, is highlighted.
FDA decisions per year · ESW
3in 2025
2026 to Oct 25, outlined.
Median 510(k) review, days · ESW
90in 2025
Receipt to decision; years with fewer than 3 clearances left blank.
Recalls per year · ESW
25in 2010
Class I (0 since 2007) Class II/III not classified
Adverse event reports per year · ESW
120in 2025
MAUDE reports naming product code ESW, not matched to any one device; reports are not rates.
View these four charts as a table
| Year | Decisions | Median 510(k) review, days | Recalls (Class I) | MAUDE reports |
|---|---|---|---|---|
| 2007 | 0 | — | 0 | 88 |
| 2008 | 5 | 99 | 0 | 153 |
| 2009 | 3 | 35 | 0 | 239 |
| 2010 | 3 | 206 | 25 | 255 |
| 2011 | 1 | — | 0 | 140 |
| 2012 | 2 | — | 0 | 121 |
| 2013 | 2 | — | 0 | 145 |
| 2014 | 0 | — | 0 | 169 |
| 2015 | 0 | — | 0 | 175 |
| 2016 | 1 | — | 0 | 153 |
| 2017 | 0 | — | 0 | 87 |
| 2018 | 2 | — | 0 | 86 |
| 2019 | 1 | — | 0 | 167 |
| 2020 | 1 | — | 0 | 155 |
| 2021 | 4 | 139 | 0 | 77 |
| 2022 | 1 | — | 0 | 109 |
| 2023 | 0 | — | 0 | 155 |
| 2024 | 4 | 130 | 0 | 166 |
| 2025 | 3 | 90 | 0 | 120 |
| 2026 | 1 | — | 0 | — |
What is it indicated for?
The Ultraflex Esophageal NG Stent System is intended for maintaining esophageal luminal patency in esophageal strictures caused by intrinsic and/or extrinsic malignant tumors only. The Ultraflex Esophageal NG Covered Stent System is also indicated for occlusion of concurrent esophageal fistuIa.
The WallFlex Esophageal Partially Covered and Fully Covered Stent System is intended for maintaining esophageal luminal patency in esophageal strictures caused by intrinsic and/or extrinsic malignant tumors, and occlusion of concurrent esophageal fistulas.
Indications for use as stated in the FDA summary.
https://510kreport.com/device/K233939 · printed Nov 6, 2026
Cite this page
510(k) Report. “K233939: Ultraflex Esophageal NG Stent System; WallFlex Esophageal Stent System.” Lineage record from FDA 510(k) data and the FDA summary. Updated Nov 3, 2026. Accessed Nov 6, 2026. https://510kreport.com/device/K233939
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Record history
- FDA decision record loaded May 2, 2026
- Summary read Oct 13, 2026 (extraction version 9eaa42aa01ed)
- Lineage and recalls computed Nov 3, 2026
- Page last updated Nov 3, 2026