Polyvinyl Alcohol Embolic Microspheres

K250209 · Canyon Medical, Inc. · KRD · Sep 23, 2025 · Cardiovascular

Device Facts

• Record ID: K250209
• Device Name: Polyvinyl Alcohol Embolic Microspheres
• Applicant: Canyon Medical, Inc.
• Product Code: KRD · Cardiovascular
• Decision Date: Sep 23, 2025
• Decision: SESE
• Submission Type: Traditional
• Regulation: 21 CFR 870.3300
• Device Class: Class 2
• Attributes: Therapeutic

Intended Use

Polyvinyl Alcohol Embolic Microspheres are intended to be used for the embolization of arteriovenous malformations (AVMs) and hypervascular tumors, including uterine fibroids.

Device Story

Polyvinyl alcohol (PVA) embolic microspheres; compressible hydrogel; non-resorbable. Supplied in 0.9% sodium chloride solution in glass vials. Used by interventional radiologists/physicians during catheter-based procedures under fluoroscopic visualization. Microspheres mixed with non-ionic contrast media prior to injection. Device injected via catheter into target vasculature to occlude blood flow to AVMs or hypervascular tumors. Mechanical occlusion reduces blood supply to target tissue; provides therapeutic benefit by shrinking tumors or treating malformations. Available in various calibrated sizes (75-1200μm) to match vessel diameter.

Clinical Evidence

No human clinical data. Evidence includes bench performance testing (size, compressibility, deliverability, pH, sterility, packaging integrity) and biocompatibility (ISO 10993). Animal study (renal artery embolization in swine) evaluated safety/efficacy via hematology, imaging, and histopathology, demonstrating performance comparable to predicate.

Technological Characteristics

Material: Polyvinyl alcohol (PVA) hydrogel. Form: Calibrated microspheres (75-1200μm). Sterilization: Moist heat (121°C, 20 min, SAL 10⁻⁶). Packaging: Borosilicate glass vials. Delivery: Catheter-based (1.7-4.0Fr). Standards: ISO 10993 (biocompatibility), ASTM D4169-22 (transportation), ASTM F1929-15 (dye penetration), ASTM F1980-21 (shelf-life), USP <71>, <85>, <731>, <791>.

Indications for Use

Indicated for embolization of arteriovenous malformations (AVMs) and hypervascular tumors, including uterine fibroids, in patients requiring vascular occlusion.

Regulatory Classification

Identification

A vascular embolization device is an intravascular implant intended to control hemorrhaging due to aneurysms, certain types of tumors (e.g., nephroma, hepatoma, uterine fibroids), and arteriovenous malformations. This does not include cyanoacrylates and other embolic agents, which act by polymerization or precipitation. Embolization devices used in neurovascular applications are also not included in this classification, see § 882.5950 of this chapter.

Special Controls

*Classification.* Class II (special controls.) The special control for this device is the FDA guidance document entitled “Class II Special Controls Guidance Document: Vascular and Neurovascular Embolization Devices.” For availability of this guidance document, see § 870.1(e).

Predicate Devices

• CalliSpheres Embolic Microspheres, 8Spheres Embolic Microspheres (K173871)

Submission Summary (Full Text)

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FDA U.S. FOOD &amp; DRUG ADMINISTRATION

September 23, 2025

Canyon Medical Inc.
Huiqi Jiang
RA Manager
Building 3, Phase 2 Accelerator, No. 11 Yaogu Avenue,
Jiangbei New Area
Nanjing, Jiangsu 210032
CHINA

Re: K250209
Trade/Device Name: Polyvinyl Alcohol Embolic Microspheres
Regulation Number: 21 CFR 870.3300
Regulation Name: Vascular Embolization Device
Regulatory Class: II
Product Code: KRD, NAJ
Dated: August 21, 2025
Received: August 22, 2025

Dear Huiqi Jiang:

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 &amp; Drug Administration
10903 New Hampshire Avenue
Silver Spring, MD 20993
www.fda.gov

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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 regulatory topic. See the DICE website (https://www.fda.gov/medical-devices/device-advice-comprehensive-regulatory-

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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,

Jason Roberts -S

Jason R. Roberts, 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

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FORM FDA 3881 (8/23)
Page 1 of 1
PBC 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) K250209 | |
| Device Name Polyvinyl Alcohol Embolic Microspheres | |
| Indications for Use (Describe) Polyvinyl Alcohol Embolic Microspheres are intended to be used for the embolization of arteriovenous malformations (AVMs) and hypervascular tumors, including uterine fibroids. | |
| 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." | |

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# 510(k) Summary

# Polyvinyl Alcohol Embolic Microspheres

## 1. 510(k) Owner

Canyon Medical Inc.

## 2. Submission Correspondent

Submitter Name: Canyon Medical Inc.

Address: Building 3, Phase 2 Accelerator, No. 11 Yaogu Avenue, Jiangbei New Area, 210032, Nanjing, Jiangsu Province, People's Republic of China

Official Correspondent: Ms. Huiqi Jiang

Position: RA Manager

E-mail: [e-mail]

Telephone: [phone]

## 3. Date of Preparation: August 22, 2025

## 4. Subject Device(s) Information

| Common Name: | Polyvinyl Alcohol Embolic Microspheres |
| --- | --- |
| Trade Name: | Polyvinyl Alcohol Embolic Microspheres |
| Regulation Number: | 21 CFR 870.3300 |
| Classification Name: | Vascular embolization device |
| Device Class: | II |
| Product Code: | KRD, NAJ |

## 5. Predicate Device(s) Information

| Manufacturer: | Suzhou Hengrui Callisyn Biomedical Co., Ltd. |
| --- | --- |
| 510(K) Number: | K173871 |
| Trade Name: | CalliSpheres Embolic Microspheres, 8Spheres Embolic Microspheres |
| Regulation Number: | 21 CFR 870.3300 |
| Classification Name: | Vascular Embolization Device |
| Device Class: | II |
| Product Code: | KRD, NAJ |

The predicate device has not been subject to a design related recall.

## 6. Device Description

The subject device polyvinyl alcohol embolic microspheres are compressible hydrogel microspheres with a regular shape, smooth surface, and calibrated size, which are formed as a result

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of chemical modification on polyvinyl alcohol (PVA) materials. The embolic microspheres consist of a macromer derived from polyvinyl alcohol (PVA) and are hydrophilic, non-resorbable. The preservation solution is 0.9% sodium chloride solution.

The polyvinyl alcohol embolic microspheres available in dyed (blue) and clear (undyed with natural color). The subject device available in particle sizes from 75-1200μm and supplied sterile in sterile sealed glass vials which contain 1 mL, 2 mL, or 3 mL of microspheres suspended in 7mL, 7mL, or 6 mL of 0.9% sodium chloride solution, respectively. The subject device configurations are provided in Table 1 below.

Table 1. Device configuration

| No. | Product Code | Dye Color | Calibrated Size (μm) | Size range (μm) | Quantity (embolic microspheres/0.9% sodium chloride solution) |
| --- | --- | --- | --- | --- | --- |
| 1 | PB-101 | Blue | 110 | 75~150 | 1mL/7mL |
| 2 | PB-102 | | | | 2mL/7mL |
| 3 | PB-103 | | | | 3mL/6mL |
| 4 | PB-201 | | 200 | 100~300 | 1mL/7mL |
| 5 | PB-202 | | | | 2mL/7mL |
| 6 | PB-203 | | | | 3mL/6mL |
| 7 | PB-401 | | 400 | 300~500 | 1mL/7mL |
| 8 | PB-402 | | | | 2mL/7mL |
| 9 | PB-403 | | | | 3mL/6mL |
| 10 | PB-601 | | 600 | 500~700 | 1mL/7mL |
| 11 | PB-602 | | | | 2mL/7mL |
| 12 | PB-603 | | | | 3mL/6mL |
| 13 | PB-801 | | 800 | 700~900 | 1mL/7mL |
| 14 | PB-802 | | | | 2mL/7mL |
| 15 | PB-803 | | | | 3mL/6mL |
| 16 | PB-1051 | | 1050 | 900~1200 | 1mL/7mL |
| 17 | PB-1052 | | | | 2mL/7mL |
| 18 | PB-1053 | | | | 3mL/6mL |
| 19 | PW-101 | Colorless | 110 | 75~150 | 1mL/7mL |
| 20 | PW-102 | | | | 2mL/7mL |
| 21 | PW-103 | | | | 3mL/6mL |
| 22 | PW-201 | | 200 | 100~300 | 1mL/7mL |
| 23 | PW-202 | | | | 2mL/7mL |
| 24 | PW-203 | | | | 3mL/6mL |
| 25 | PW-401 | | 400 | 300~500 | 1mL/7mL |
| 26 | PW-402 | | | | 2mL/7mL |
| 27 | PW-403 | | | | 3mL/6mL |
| 28 | PW-601 | | 600 | 500~700 | 1mL/7mL |
| 29 | PW-602 | | | | 2mL/7mL |

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| No. | Product Code | Dye Color | Calibrated Size (μm) | Size range (μm) | Quantity (embolic microspheres/0.9% sodium chloride solution) |
| --- | --- | --- | --- | --- | --- |
| 30 | PW-603 | | | | 3mL/6mL |
| 31 | PW-801 | | 800 | 700~900 | 1mL/7mL |
| 32 | PW-802 | | | | 2mL/7mL |
| 33 | PW-803 | | | | 3mL/6mL |
| 34 | PW-1051 | | 1050 | 900~1200 | 1mL/7mL |
| 35 | PW-1052 | | | | 2mL/7mL |
| 36 | PW-1053 | | | | 3mL/6mL |
| Size (μm) | Indication – Hypervascular Tumors/ Arteriovenous Malformations | Indication-Uterine Fibroid |
| --- | --- | --- |
| 75~150 | Yes | No |
| 100~300 | Yes | No |
| 300~500 | Yes | No |
| 500~700 | Yes | Yes |
| 700~900 | Yes | Yes |
| 900~1200 | Yes | Yes |

## 7. Indications for Use

Polyvinyl Alcohol Embolic Microspheres are intended to be used for the embolization of arteriovenous malformations (AVMs) and hypervascular tumors, including uterine fibroids.

## 8. Summary and Comparison of Technological Characteristics

Equivalence comparison has been identified with following summary of technical characteristics:

Table 2. Technological Characteristic Comparison Table

| Device Characteristic | Subject Device: Polyvinyl Alcohol Embolic Microspheres | Predicate Device: CalliSpheres and 8Spheres Embolic Microspheres |
| --- | --- | --- |
| 510(k) Number | K250209 | K173871 |
| Classification | II | II |
| Product Code | KRD, NAJ | KRD, NAJ |

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| Device Characteristic | Subject Device: Polyvinyl Alcohol Embolic Microspheres | Predicate Device: CalliSpheres and 8Spheres Embolic Microspheres |
| --- | --- | --- |
| Regulation Number | 21CFR 870.3300 | 21CFR 870.3300 |
| Intended Use/ Indication for Use | Intended to be used for the embolization of arteriovenous malformations (AVMs) and hypervascular tumors, including uterine fibroids. | Intended to be used for the embolization of arteriovenous malformations (AVMs) and hypervascular tumors, including uterine fibroids. |
| Polymerization Method | Suspension polymerization | Suspension polymerization |
| Resorption | Non-resorbable | Non-resorbable |
| Appearance | Hydrogel microspheres with regular shape, smooth surface and calibrated size, Blue dyed or undyed | Hydrogel microspheres with regular shape, smooth surface and calibrated size. CalliSpheres: Blue dyed 8Spheres: Undyed |
| Microsphere Polymer Composition | Polyvinyl alcohol (PVA) | Polyvinyl alcohol (PVA) |
| Storage media | 0.9% sodium chloride solution | 0.9% sodium chloride solution |
| Size Range | Size range: 75-1200μm
Labeled size range: 75-150μm
100-300μm
300-500μm
500-700μm
700-900μm
900-1200μm | Size range: 100-1200μm
Labeled size range: 100-300μm
300-500μm
500-700μm
700-900μm
900-1200μm |
| Quantity (embolic microspheres/0.9% sodium chloride solution) | 1mL/7mL
2mL/7mL
3mL/6mL | 1mL/7mL
2mL/7mL |
| Packaging | Sealed in borosilicate glass vial | Sealed in borosilicate glass vial |
| Compressibility | 50% by diameter | 30% by diameter |
| Compatible Delivery Catheter | 1.7-4.0Fr | 1.7-4.0Fr |
| Radiopacity Method | Mixed with non-ionic contrast media prior to injection | Mixed with non-ionic contrast media prior to injection |

4

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| Device Characteristic | Subject Device: Polyvinyl Alcohol Embolic Microspheres | Predicate Device: CalliSpheres and 8Spheres Embolic Microspheres |
| --- | --- | --- |
| Delivery Method | Via catheter under fluoroscopic visualization | Via catheter under fluoroscopic visualization |
| Method of Supply | Sterile and single use | Sterile and single use |
| Sterilization | Moist heat and non-pyrogenic | Moist heat and non-pyrogenic |
| Shelf Life | Three years | Two years |

The technological characteristics of the subject device are similar to those of predicate devices. The minimum particle size for the predicate device (100μm) is larger than the minimum particle size for the subject device (75μm). However, smaller sized microspheres have been cleared for similar indications, and has the same basic design as the predicate device. The comparison between the subject and predicate devices is based on the following:

- Same indications for use
- Same fundamental technology

The differences in the particle sizes does not raise different questions of safety and effectiveness.

## 9. Non-Clinical Test Summary

The device is subject to Guidance for Industry and FDA Staff - Class II Special Controls Guidance Document: Vascular and Neurovascular Embolization Devices issued on 29 December 2004. The safety and effectiveness have been evaluated by non-clinical performance testing including:

### Performance Testing

The following specifications and performance testing were evaluated on the subject device, and all tests were passed and demonstrated the subject devices can meet the product requirements.

- Appearance
- Quantity
- Microsphere Size
- Compressibility
- Catheter deliverability
- Suspension
- Water content per USP-NF 2025 &lt;731&gt; Loss on drying
- pH per USP-NF 2025 &lt;791&gt;
- Impurities and Residual Solvents
- Sterility per USP-NF 2025 &lt;71&gt;
- Bacterial Endotoxins per USP-NF 2025 &lt;85&gt;
- Packaging integrity
- Transportation
- Shelf life

### Biocompatibility Evaluation

Biocompatibility testing for the subject device was conducted in accordance with FDA guidance,

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Use of International Standard ISO 10993-1, "Biological evaluation of medical devices - Part 1: Evaluation and testing within a risk management process". Biocompatibility tests were completed, and the results demonstrate the subject device is biocompatible.

Table 3. Biocompatibility Evaluation Table

| Biological Endpoint | Test Method | Results |
| --- | --- | --- |
| MTT Cytotoxicity Test | ISO 10993-5:2009 | Non-cytotoxic |
| ISO Guinea Pig Maximization Sensitization Test | ISO 10993-10:2021 | Non-sensitizer |
| ISO Intracutaneous Study in Rabbits | ISO 10993-10:2010 | Non-irritant |
| ISO Acute Systemic Toxicity Study in Mice | ISO 10993-11:2017 | No mortality or evidence of systemic toxicity |
| ASTM Hemolysis Study | ISO 10993-4:2017 | Non-hemolytic |
| USP Rabbit Pyrogen Study, Material Mediated | ISO 10993-11:2021 | Non-pyrogenic |
| ISO Muscle Implantation Study in Rabbits, 1 Week | ISO 10993-6:2016 | The macroscopic reaction was not significant as compared to the negative control article.
Microscopically, the test article caused a minimal to no reaction as compared to the negative control article. |
| ISO Muscle Implantation Study in Rabbits, 4 Weeks | ISO 10993-6:2016 | The macroscopic reaction was not significant as compared to the negative control article.
Microscopically, the test article caused a minimal to no reaction as compared to the negative control article. |

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| ISO Muscle Implantation Study in Rabbits, 13 Weeks | ISO 10993-6:2016 | The macroscopic reaction was not significant as compared to the negative control article. Microscopically, the test article caused a minimal reaction as compared to the negative control article. |
| --- | --- | --- |

## Chemical Characterization and Toxicological Risk Assessment

Chemical characterization testing was conducted on the subject device Polyvinyl Alcohol Embolic Microspheres in accordance with ISO 10993-18:2022. A Toxicological risk assessment in accordance with ISO 10993-17:2023, using a worst-case risk assessment approach was conducted based upon the findings of the exhaustive extraction. Using this approach, it was determined that the margins of safety (MOS) for potential chemical exposures indicated a low risk of chronic toxicity and carcinogenicity.

## Sterility, Shipping, and Shelf-life

The proposed device is sterilized by moist heat steam which under validated parameters (121°C, 20 minutes) after sealing the vials to achieve a sterility assurance level (SAL) of 10⁻⁶ in accordance with USP &lt;71&gt; and ISO 17665:2015. Bacterial Endotoxin Levels were below the level of 0.5 EU/ml in accordance with USP &lt;85&gt;. Both baseline and accelerated shelf life testing were conducted demonstrating the device will perform as intended to support the proposed 3 year shelf-life.

- Package integrity test – after environmental conditioning, simulated transportation testing in accordance to ASTM D4169-22 on final, packaged, and sterile device.
- Sterile Barrier Packaging performed on the proposed device:
- Dye penetration ASTM F1929-15
- Shelf-life of 3-years is validated using FDA recognized standard ASTM F1980 -21 Standard Guide for Accelerated Aging of Sterile Barrier Systems for Medical Devices.

## Animal Study Testing

This animal study simulated the clinical use of polyvinyl alcohol embolization microspheres and performed partial renal artery embolization of healthy white swine through interventional surgery. The effectiveness evaluated by observing the performance of the intra-operative procedures, the parameters of the embolized vessel, and the embolization effect in the immediate and test periods. The safety and efficacy of the test article were initially evaluated by observing the overall recovery of the animals after the operation, and by combining hematological tests (blood coagulation and serum biochemistry, etc.), imaging changes in the kidneys, clinicopathology, gross anatomical observations, and histopathological manifestations of the embolized localities and the major organs of the whole body at multiple time points before and after the operation. The results demonstrate that the subject device is as safe and effective as the cleared Polyvinyl Alcohol Embolic

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Microspheres (K173871).

## 10. Conclusion

The conclusions drawn from the comparison, analysis, and nonclinical testing above demonstrate that the proposed subject devices raise no new questions of safety or effectiveness, and are as safe, as effective, and perform as well as the legally marketed predicate devices for proposed indications for use.

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