Ureteral Stents (AF-D series)

K243039 · Alton (Shanghai) Medical Instruments Co., Ltd. · FAD · Jun 18, 2025 · Gastroenterology, Urology

Device Facts

• Record ID: K243039
• Device Name: Ureteral Stents (AF-D series)
• Applicant: Alton (Shanghai) Medical Instruments Co., Ltd.
• Product Code: FAD · Gastroenterology, Urology
• Decision Date: Jun 18, 2025
• Decision: SESE
• Submission Type: Traditional
• Regulation: 21 CFR 876.4620
• Device Class: Class 2
• Attributes: Therapeutic

Intended Use

Ureteral Stents (AF-D series) are used for temporary internal drainage from the ureteropelvic junction to the bladder. Ureteral Stents have been used to relieve obstruction in a variety of benign, malignant, and post-traumatic conditions. The stents may be placed using endoscopic, percutaneous, or open surgical techniques. The indwelling time should not exceed 30 days.

Device Story

Flexible, tubular double-pigtail ureteral stent; composed of thermoplastic polyurethane with hydrophilic coating. Used for temporary internal drainage from ureteropelvic junction to bladder; relieves obstruction in benign, malignant, or post-traumatic conditions. Placed by physicians (urologists/surgeons) via endoscopic, percutaneous, or open surgical techniques. Available in 4.0-7.0 Fr diameters; 8.0-28.0 cm lengths. Supplied sterile for single-use; indwelling time ≤30 days. Device configurations include stent only, or with introducer, guidewire, and clamp. Visible under fluoroscopy. Provides drainage to alleviate obstruction, improving patient outcomes by preventing hydronephrosis or related complications.

Clinical Evidence

No clinical data. Substantial equivalence supported by bench testing, including biocompatibility (ISO 10993-1), sterility (ISO 11135), shelf-life/packaging integrity, and mechanical performance (curl retention, break strength, flow rate, kink stability, friction force, and insertion/removal testing).

Technological Characteristics

Thermoplastic polyurethane with hydrophilic coating; double-pigtail configuration. Sterilized via Ethylene Oxide (ISO 11135:2014). 4.0-7.0 Fr diameter; 8.0-28.0 cm length. Radiopaque under fluoroscopy. Single-use, non-permanent (≤30 days).

Indications for Use

Indicated for temporary internal drainage from the ureteropelvic junction to the bladder in patients requiring relief of obstruction due to benign, malignant, or post-traumatic conditions. Suitable for placement via endoscopic, percutaneous, or open surgical techniques. Indwelling time limited to 30 days.

Regulatory Classification

Identification

A ureteral stent is a tube-like implanted device that is inserted into the ureter to provide ureteral rigidity and allow the passage of urine. The device may have finger-like protrusions or hooked ends to keep the tube in place. It is used in the treatment of ureteral injuries and ureteral obstruction.

Predicate Devices

• Universa Soft Ureteral Stents and Stent Sets (K151051)

Reference Devices

• Pediatric Ureteral Stent Open Tip/Closed Tip (K190659)

Submission Summary (Full Text)

{0}

FDA U.S. FOOD & DRUG ADMINISTRATION

June 18, 2025

Alton (Shanghai) Medical Instruments Co. Ltd
Wei Song
Project Engineer
No.24 Building, Jinshao Rd. 1688, Baoshan District
Shanghai 200949
CHINA

Re: K243039
Trade/Device Name: Ureteral Stents (AF-D series)
Regulation Number: 21 CFR 876.4620
Regulation Name: Ureteral Stent
Regulatory Class: Class II
Product Code: FAD
Dated: May 23, 2025
Received: May 23, 2025

Dear Wei Song:

We have reviewed your section 510(k) premarket notification of intent to market the device referenced above and have determined the device is substantially equivalent (for the indications for use stated in the enclosure) to legally marketed predicate devices marketed in interstate commerce prior to May 28, 1976, the enactment date of the Medical Device Amendments, or to devices that have been reclassified in accordance with the provisions of the Federal Food, Drug, and Cosmetic Act (the Act) that do not require approval of a premarket approval application (PMA). You may, therefore, market the device, subject to the general controls provisions of the Act. Although this letter refers to your product as a device, please be aware that some cleared products may instead be combination products. The 510(k) Premarket Notification Database available at https://www.accessdata.fda.gov/scripts/cdrh/cfdocs/cfpmn/pmn.cfm identifies combination product submissions. The general controls provisions of the Act include requirements for annual registration, listing of devices, good manufacturing practice, labeling, and prohibitions against misbranding and adulteration. Please note: CDRH does not evaluate information related to contract liability warranties. We remind you, however, that device labeling must be truthful and not misleading.

If your device is classified (see above) into either class II (Special Controls) or class III (PMA), it may be subject to additional controls. Existing major regulations affecting your device can be found in the Code of Federal Regulations, Title 21, Parts 800 to 898. In addition, FDA may publish further announcements concerning your device in the Federal Register.

U.S. Food & Drug Administration
10903 New Hampshire Avenue
Silver Spring, MD 20993
www.fda.gov

{1}

K243039 - Wei Song
Page 2

Additional information about changes that may require a new premarket notification are provided in the FDA guidance documents entitled "Deciding When to Submit a 510(k) for a Change to an Existing Device" (https://www.fda.gov/media/99812/download) and "Deciding When to Submit a 510(k) for a Software Change to an Existing Device" (https://www.fda.gov/media/99785/download).

Your device is also subject to, among other requirements, the Quality System (QS) regulation (21 CFR Part 820), which includes, but is not limited to, 21 CFR 820.30, Design controls; 21 CFR 820.90, Nonconforming product; and 21 CFR 820.100, Corrective and preventive action. Please note that regardless of whether a change requires premarket review, the QS regulation requires device manufacturers to review and approve changes to device design and production (21 CFR 820.30 and 21 CFR 820.70) and document changes and approvals in the device master record (21 CFR 820.181).

Please be advised that FDA's issuance of a substantial equivalence determination does not mean that FDA has made a determination that your device complies with other requirements of the Act or any Federal statutes and regulations administered by other Federal agencies. You must comply with all the Act's requirements, including, but not limited to: registration and listing (21 CFR Part 807); labeling (21 CFR Part 801); medical device reporting (reporting of medical device-related adverse events) (21 CFR Part 803) for devices or postmarketing safety reporting (21 CFR Part 4, Subpart B) for combination products (see https://www.fda.gov/combination-products/guidance-regulatory-information/postmarketing-safety-reporting-combination-products); good manufacturing practice requirements as set forth in the quality systems (QS) regulation (21 CFR Part 820) for devices or current good manufacturing practices (21 CFR Part 4, Subpart A) for combination products; and, if applicable, the electronic product radiation control provisions (Sections 531-542 of the Act); 21 CFR Parts 1000-1050.

All medical devices, including Class I and unclassified devices and combination product device constituent parts are required to be in compliance with the final Unique Device Identification System rule ("UDI Rule"). The UDI Rule requires, among other things, that a device bear a unique device identifier (UDI) on its label and package (21 CFR 801.20(a)) unless an exception or alternative applies (21 CFR 801.20(b)) and that the dates on the device label be formatted in accordance with 21 CFR 801.18. The UDI Rule (21 CFR 830.300(a) and 830.320(b)) also requires that certain information be submitted to the Global Unique Device Identification Database (GUDID) (21 CFR Part 830 Subpart E). For additional information on these requirements, please see the UDI System webpage at https://www.fda.gov/medical-devices/device-advice-comprehensive-regulatory-assistance/unique-device-identification-system-udi-system.

Also, please note the regulation entitled, "Misbranding by reference to premarket notification" (21 CFR 807.97). For questions regarding the reporting of adverse events under the MDR regulation (21 CFR Part 803), please go to https://www.fda.gov/medical-devices/medical-device-safety/medical-device-reporting-mdr-how-report-medical-device-problems.

For comprehensive regulatory information about medical devices and radiation-emitting products, including information about labeling regulations, please see Device Advice (https://www.fda.gov/medical-devices/device-advice-comprehensive-regulatory-assistance) and CDRH Learn (https://www.fda.gov/training-and-continuing-education/cdrh-learn). Additionally, you may contact the Division of Industry and Consumer Education (DICE) to ask a question about a specific

{2}

K243039 - Wei Song
Page 3

regulatory topic. See the DICE website (https://www.fda.gov/medical-devices/device-advice-comprehensive-regulatory-assistance/contact-us-division-industry-and-consumer-education-dice) for more information or contact DICE by email ([e-mail]) or phone [phone] or 301-796-7100).

Sincerely,

Angel A. Soler-garcia -S

for

Jessica Nguyen, Ph.D.

Assistant Director

DHT3B: Division of Reproductive,
Gynecology, and Urology Devices

OHT3: Office of Gastrorenal, ObGyn,
General Hospital, and Urology Devices

Office of Product Evaluation and Quality

Center for Devices and Radiological Health

Enclosure

{3}

FORM FDA 3881 (8/23)
Page 1 of 1
PSC Publishing Services [phone]
EF

| DEPARTMENT OF HEALTH AND HUMAN SERVICES Food and Drug Administration Indications for Use | Form Approved: OMB No. 0910-0120 Expiration Date: 07/31/2026 See PRA Statement below. |
| --- | --- |
| 510(k) Number (if known) K243039 | |
| Device Name Ureteral Stents (AF-D series) | |
| Indications for Use (Describe) Ureteral Stents (AF-D series) are used for temporary internal drainage from the ureteropelvic junction to the bladder. Ureteral Stents have been used to relieve obstruction in a variety of benign, malignant, and post-traumatic conditions. The stents may be placed using endoscopic, percutaneous, or open surgical techniques. The indwelling time should not exceed 30 days. | |
| Type of Use (Select one or both, as applicable) ☑ Prescription Use (Part 21 CFR 801 Subpart D) ☐ Over-The-Counter Use (21 CFR 801 Subpart C) | |
| CONTINUE ON A SEPARATE PAGE IF NEEDED. | |
| This section applies only to requirements of the Paperwork Reduction Act of 1995. *DO NOT SEND YOUR COMPLETED FORM TO THE PRA STAFF EMAIL ADDRESS BELOW.* | |
| The burden time for this collection of information is estimated to average 79 hours per response, including the time to review instructions, search existing data sources, gather and maintain the data needed and complete and review the collection of information. Send comments regarding this burden estimate or any other aspect of this information collection, including suggestions for reducing this burden, to: Department of Health and Human Services Food and Drug Administration Office of Chief Information Officer Paperwork Reduction Act (PRA) Staff [e-mail] | |
| "An agency may not conduct or sponsor, and a person is not required to respond to, a collection of information unless it displays a currently valid OMB number." | |

{4}

K243039
Page 1 of 4

# 510(k) Summary

## I. Submitter Information

510(k) Submitter: Alton (Shanghai) Medical Instruments Co. Ltd.

Address: No.24 Building, JinShao Rd. 1688, Baoshan District, 200949 Shanghai, P. R. China

Contact Person: Vivian Li
Director of Quality
Phone: [phone]
Fax: [phone]
Mail: [e-mail]

Preparation Date: June 15, 2025

## II. Subject Device

Trade Name of Device: Ureteral Stents (AF-D series)

Classification Name: Stent, Ureteral

Regulation Number: 21 CFR 876.4620

Device Class: Class II

Review Panel: Gastroenterology/Urology

Product Code: FAD

## III. Predicate and Reference Devices

### Predicate Device:

510(k) Number: K151051

510(k) Holder: Cook Incorporated

Trade Name of Device: Universa Soft Ureteral Stents and Stent Sets

Classification Name: Stent, Ureteral

Regulation Number: 21 CFR 876.4620

Device Class: Class II

Review Panel: Gastroenterology/Urology

Product Code: FAD

### Reference Device:

510(k) Number: K190659

Trade Name of Device: Pediatric Ureteral Stent Open Tip/Closed Tip

Classification Name: Stent, Ureteral

Regulation Number: 21 CFR 876.4620

Device Class: Class II

Review Panel: Gastroenterology/Urology

{5}

K243039
Page 2 of 4

Product Code: FAD

## IV. Device Description

Ureteral Stents (AF-D series) are a set of ureteral stents used for temporary internal drainage from the ureteropelvic junction to the bladder. The subject ureteral stent is a flexible, tubular double pigtail stent composed of thermoplastic polyurethane with hydrophilic coating. Depending on configurations, the device may include a ureteral stent only, or a stent with an introducer and a clamp, or a stent with an introducer, a guidewire and a clamp.

Ureteral Stents are available in 4.0 to 7.0 French (Fr) diameter, with lengths ranging from 8.0 to 28.0 centimeters (cm). The device is supplied sterile, intended for single use only, and is available for prescription use only.

Ureteral Stents are not intended as a permanent indwelling device. The subject stent is labeled for indwell time not to exceed thirty (30) days only.

## V. Indications for Use

Ureteral Stents (AF-D series) are used for temporary internal drainage from the ureteropelvic junction to the bladder. Ureteral Stents have been used to relieve obstruction in a variety of benign, malignant, and post-traumatic conditions. The stents may be placed using endoscopic, percutaneous, or open surgical techniques. The indwelling time should not exceed 30 days.

## VI. Comparison of Technological Characteristics with Predicate Device

| Device Characteristics | K243039
Ureteral Stents
(AF-D series)
(Subject Device) | K151051
Universal Soft Ureteral Stents
and Stent Sets
(Predicate device) |
| --- | --- | --- |
| Manufacturer | Alton (Shanghai) Medical Instruments Co., Ltd. | Cook Incorporated |
| Regulation No. | 876.4620 | 876.4620 |
| Product Code | FAD | FAD |
| Classification | Class II | Class II |
| | | |
| Indications for Use | Ureteral Stents (AF-D series) are used for temporary internal drainage from the ureteropelvic junction to the bladder. Ureteral Stents have been used to relieve obstruction in a variety of benign, malignant, and post-traumatic conditions. The stents may be placed using endoscopic, percutaneous, or open surgical techniques. The indwelling time should not exceed 30 days. | The Universal Soft Ureteral Stents and Stent Sets are used for temporary internal drainage from the ureteropelvic junction to the bladder. Ureteral Stents have been used to relieve obstruction in a variety of benign, malignant, and post-traumatic conditions. The stents may be placed using endoscopic, percutaneous, or open surgical techniques. |
| | | |
| Surgical Technique | • Stent is visible under fluoroscopy.
• Stent placement via endoscopic, percutaneous or open surgical techniques. | • Stent is visible under fluoroscopy.
• Stent placement via endoscopic, percutaneous or open surgical techniques. |

{6}

K243039
Page 3 of 4

| Indwell Time | Not to exceed thirty (30) days. | For a 6-month indwell time |
| --- | --- | --- |
| **General Technological Characteristics** | | |
| Device Configurations | • Ureteral Stent only
• Ureteral Stent + Introducer + Clamp
• Ureteral Stent + Introducer + Guide Wire + Clamp | • Ureteral Stent only
• Ureteral Stent + Positioner
• Ureteral Stent + Positioner + Guide wire |
| Other Components | No | • A suture tether attached to the proximal pigtail of the stent.
• A pigtail straightener |
| Stent Diameter | 4Fr, 5Fr, 6Fr, 7Fr | 5Fr, 6Fr, 7Fr, 8Fr |
| Stent Length | 8.0cm, 10cm, 12cm, 14cm, 16cm, 18cm, 20cm, 22cm, 24cm, 26cm, 28cm | 8-30 cm |
| Stent Coils | Double pigtails | Double pigtails |
| Introducer or Positioner | • Diameter: 4Fr, 5Fr, 6Fr, 7Fr
• Length: 60cm | • Diameter: 5Fr, 6Fr, 7Fr, 8Fr
• Length: Not identified |
| Characteristics of Introducer/Positioner | No radiopaque tip | With a radiopaque tip |
| Guidewire | • Diameter: 0.025" for 4Fr/5Fr stents; 0.035" for 6Fr/7Fr stents
• Length: 15cm | • Diameter: 0.035" for 5Fr stent; 0.038" for 6Fr/7Fr/8Fr stents
• Length: Not specified. |
| Sterilization | EtO | EtO |
| Single use | Yes | Yes |

As evidenced by the above table, both the subject and predicate devices have similar intended use, but they have different technological characteristics. Performance testing was conducted on the subject stents, and it was established that the differences in technological characteristics between the subject and predicate devices do not raise different questions of safety or effectiveness.

## VII. Non-Clinical Data

Ureteral Stents (AF-D series) were tested and demonstrated to be equivalent to the predicate device in safety and performance.

### Biocompatibility Testing:

Biocompatibility of Ureteral Stents was evaluated in accordance with the FDA guidance “Use of International Standard ISO 10993-1, ‘Biological evaluation of medical devices - Part 1: Evaluation and testing within a risk management process’” (September 4, 2020). The following biocompatibility testing was conducted:

- Cytotoxicity
- Sensitization
- Intracutaneous Reactivity
- Acute Systemic Toxicity
- Material-Mediated Pyrogenicity
- Subacute Systemic Toxicity
- Muscle Implantation
- Genotoxicity

{7}

K243039
Page 4 of 4

## Sterility and Shelf Life:

The subject device is sterilized by Ethylene Oxide Gas to achieve a SAL of 10⁻⁶ (ISO 11135:2014) and the device packaging was tested for integrity in maintaining a sterile barrier over a shelf life of 3 years. An accelerated aging study and simulated transportation study were conducted on representative device models to demonstrate that the subject device was able to maintain the device performance over a shelf life of 3 years.

## Bench Performance Testing:

A battery of bench testing based on the FDA guidance “Guidance for the Content of Premarket Notification for Ureteral Stents” (1993) was conducted on the subject, predicate and reference stents using established methods and standards to demonstrate the performance substantial equivalence to the predicate device. The reference device was used to support the function and performance of the 4Fr pediatric configuration in the subject device.

The performance evaluations included:
- Appearance and Dimensions
- Curl Retention Test (pigtails)
- Break Strength & Elongation
- Flow Rate
- Dynamic Friction Force
- Kink Stability Test
- Simulated Stent Insertion and Removal Test
- Chemical Performance
- Guidewire: Radiopacity, bending test, compatibility with stent and introducer

## VIII. Clinical Testing

No clinical study is included in this submission.

## IX. Conclusions

The proposed device has the same indication for use and has similar design features and technological characteristic as the predicate device. Performance testing data demonstrates that the proposed device is as safe and effective as the predicate device. Therefore, the subject device is substantially equivalent to the predicate device.