The Micro Therapeutics Thrombolytic Brush Catheter is intended for percutaneous dissolution of acute thrombus (i.e., less than two weeks old) located in artificial arteriovenous (A-V) grafts. The Thrombolytic Brush Catheter is designed to augment the area of interface between clot and pharmacologic agent by simultaneous thrombolysis and clot maceration. Clinical studies demonstrate effective dissolution of thrombus in A-V grafts when this product is used in conjunction with urokinase. The Thrombolytic Brush Catheter is not intended for use in native vessels. The device should not be used on patients with a history of significant pulmonary disease or pulmonary hypertension.

Device Description

The Micro Therapeutics Thrombolytic Brush Catheter is intended for the percutaneous dissolution of thrombus located in arteriovenous (A-V) grafts. The Micro Therapeutics Thrombolytic Brush Catheter is designed to augment the area of interface between clot and pharmacologic agent by simultaneous thrombolysis and clot maceration. The integral system utilizes a catheter with proximal Y-connector, a soft nylon brush attached to a stainless steel flexible drive cable, and a hand-held battery-powered motor drive.

AI/ML Overview

Here's a breakdown of the acceptance criteria and study details for the Micro Therapeutics Thrombolytic Brush Catheter and Motor Drive, based only on the provided text.

1. Table of Acceptance Criteria and Reported Device Performance

The provided text does not explicitly state pre-defined acceptance criteria with numerical targets. Instead, the "Summary of Clinical Trials" table presents various metrics of device performance for both the Thrombolytic Brush Catheter and a control group (pulse-spray infusion) and then performs statistical comparisons. The conclusion states that the clinical data "demonstrate the Thrombolytic Brush Catheter is a safe, effective and rapid alternative to pulse-spray thrombolysis." This implies that showing superiority or non-inferiority to the control group on various metrics was the implicit acceptance criteria.

Parameter	Thrombolytic Brush Catheter (Performance)	Pulse-Spray Infusion (Control)	Statistical Comparison	Implied Acceptance Criteria (Vs. Control)
Duration of lytic procedure	17 minutes	28 minutes	Significant (p=.0001)	Shorter duration
Residual thrombus after lytic procedure	6.5%	25.5%	Significant (p=.0001)	Less residual thrombus
Urokinase dose used	215,435 Units	455,882 Units	Significant (p=.0001)	Lower urokinase dose
Heparin dose used	2,570 Units	4,926 Units	Significant (p=.0001)	Lower heparin dose
Acute success of lytic procedure (Graft patent within 30 minutes)	42/43 (98%)	15/35 (43%)	Significant (p=.0001)	Higher acute success rate
Stenotic lesion visualized	41/41 (100%)	33/33 (100%)	Not Significant (p=1.000)	Comparable visualization
Thrombectomy performed to remove residual thrombus	14/41 (34%)	14/33 (42%)	Not Significant (p=.481)	Comparable need for thrombectomy
PTA performed to treat stenotic lesion	41/41 (100%)	32/32 (100%)	Not Significant (p=1.000)	Comparable need for PTA
Residual thrombus after thrombectomy and/or PTA	2.2%	1.6%	Not Significant (p=.6607)	Comparable final residual thrombus (though slightly higher for device, p not significant)
Duration of entire procedure	70 minutes	84 minutes	Not Significant (p=.1735)	Comparable total procedure duration (though shorter for device, p not significant)
Procedural success after all interventions (Graft patent, no major complications)	39/43 (91%)	34/35 (97%)	Not Significant (p=.621)	Comparable overall procedural success (though slightly lower for device, p not significant)
Successful dialysis after all interventions	34/39 (87%)	30/34 (88%)	Lifetable analysis: Not significant	Comparable successful dialysis (though slightly lower for device, lifetable analysis not significant)
Primary Patency at 3 months	16/38 (42%)	15/31 (48%)	Lifetable analysis: Not significant	Comparable primary patency at 3 months (though slightly lower for device, lifetable analysis not significant)
Failures within 3 months	22/38 (58%)	16/31 (52%)	Lifetable analysis: Not significant	Comparable failure rate at 3 months (though slightly higher for device, lifetable analysis not significant)
Primary Patency at 4½ months	14/38 (37%)	14/30 (47%)	Lifetable analysis: Not significant	Comparable primary patency at 4.5 months (though slightly lower for device, lifetable analysis not significant)
Failures within 4½ months	24/38 (63%)	16/30 (53%)	Lifetable analysis: Not significant	Comparable failure rate at 4.5 months (though slightly higher for device, lifetable analysis not significant)

2. Sample Size Used for the Test Set and Data Provenance

Sample Size: 81 patients in total, with 45 randomized to the Thrombolytic Brush Catheter treatment group and 36 to the pulse-spray infusion control group. For analysis, these translated to 43 grafts treated in the device group and 35 in the control group for some metrics, with some variations due to no follow-up or missing data for specific parameters.
Data Provenance: Prospective, randomized clinical trial conducted at five institutions in the United States.

3. Number of Experts Used to Establish the Ground Truth for the Test Set and Their Qualifications

The document does not explicitly state the number of experts or their qualifications used to establish ground truth for the clinical trial data. The assessment of "residual thrombus" and "patency" would typically involve physician judgment (likely interventional radiologists or nephrologists involved in AV graft management), but specifics are not provided.

4. Adjudication Method for the Test Set

The document does not describe any specific adjudication method (e.g., 2+1, 3+1) for the clinical trial results. Data would have been collected by the investigators at each of the five institutions.

5. If a Multi-Reader Multi-Case (MRMC) Comparative Effectiveness Study Was Done, and the Effect Size of How Much Human Readers Improve With AI vs Without AI Assistance

No, a Multi-Reader Multi-Case (MRMC) comparative effectiveness study was not done. This study is for a medical device (catheter and motor drive) used by clinicians, not an AI-based diagnostic or imaging interpretation tool. Therefore, the concept of human readers improving with AI assistance is not applicable here.

6. If a Standalone (Algorithm Only Without Human-in-the-Loop Performance) Was Done

No, this question is not applicable. The device is a physical catheter and motor drive, not an algorithm. Its performance inherently requires human operation.

7. The Type of Ground Truth Used

The ground truth used in the clinical trial was primarily clinical outcomes and measurements as assessed by the treating physicians and follow-up. This included:

Measurement of residual thrombus.
Assessment of graft patency (ability to dialyze).
Duration of procedures.
Dosages of pharmacological agents.
Incidence of interventions like thrombectomy and PTA.
Follow-up data on primary patency and failures.

These are clinical observations and measurements, not pathology reports or a separate expert consensus on images (as would be typical for an imaging AI device).

8. The Sample Size for the Training Set

This study involves a medical device, not a machine learning model, so there is no concept of a "training set" in the context of algorithm development. The development process would have involved engineering design, in vitro testing, and animal studies.

9. How the Ground Truth for the Training Set Was Established

As there is no training set for an algorithm, this question is not applicable. For general device development, "ground truth" (e.g., for design validation) would be established through engineering specifications, validated test methods (in vitro), and histological/clinical observations from animal studies (in vivo). The text describes extensive physical bench testing, biocompatibility tests, and animal studies as part of the overall development and verification.

Summary

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063975

510(k) SUMMARY

Micro Therapeutics, Inc. 1062-F Calle Negocio San Clemente, CA 92673 (714) 361-0616

AUG - 8 1997

Contact Person

John L. Gehrich, Ph.D. Vice President of Regulatory & Clinical Affairs

Trade Name

Thrombolytic Brush Catheter and Motor Drive

Classification Name

Graft Thrombectomy Catheter Infusion Catheter

Substantially Equivalent Devices

Fogarty® Graft Thrombectomy Catheter (Baxter Corp.) Mewissen Infusion Catheter (MediTech) Amplatz Thrombectomy Device (Microvena)

Description

Intended Use

Technological Characteristics

This product is equivalent in intended use as well as dimensional characteristics, composition and function to the legally marketed Baxter Fogarty® Graft Thrombectory Catheter, manufactured by Baxter Healthcare Corporation, as well as the MediTech Mewissen Infusion Catheter.

This product is equivalent in intended use as well as composition and function to the legally marketed Amplatz Thrombectorny Device, (K954205) manufactured by Microvena, Corporation,

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Summary of Studies

Performance Data

In Vitro Tests

Sample devices were subjected to extensive physical bench testing. In vitro tests were conducted which included complete dimensional measurements, bristle and wire cable strength characterization, motor drive integrity testing, catheter flow rates, bond strengths, burst pressure and performance under simulated conditions. Additionally, electromagnetic and patient safety tests were conducted by an independent laboratory to evaluate the electromagnetic and leakage current potential of the battery operated motor drive handle. Based on the results from these tests, it was concluded that the design offered a considerable safety margin in critical areas and is suitable for its intended use.

Radiopacity

The radiopacity of the Thrombolytic Brush Catheter is comparable to other vascular catheters. The materials used in the manufacture of the Thrombolytic Brush Catheter are the same as the predicate devices listed in the 510(k), utilizing medical grade plastic, stainless steel and radiopaque positioning markers. The stainless steel cable drive and brush tip of the Thrombolytic Brush Catheter are adequately visualized under fluoroscopy and the catheter body has a platinum alloy marker band at the distal tip. Adequate radiopacity was demonstrated in both the animal trial and in the clinical study by the ability of all investigators to visualize the device under fluoroscopy.

Biocompatibility Tests

Tests for biocompatibility of materials for the Micro Therapeutics Thrombolytic Brush Catheter were performed to establish that the materials used in the device met the qualifications for short-term use in the vascular system in accordance with ISO 10993-1. Biocompatibility testing was performed on sterile product. In determining biocompatibility test design, testing was selected as deemed appropriate for the type of tissue/device interface and the duration of patient exposure. The results of these tests demonstrate the toxicological safety of the Thrombolytic Brush Catheter for its intended use.

In Vivo Tests

In vivo animal tests were performed to assess ease of use, suitable flexibility/stiffness required, safety and efficacy.

Histologic examinations were performed both in the arterial and venous portion of the anastomosis as well as macro- and microscopic examination of sliced 3mm sections of lung. Animal studies were performed at the University of Illinois College of Medicine at Peoria in Peoria, Illinois. The study was approved by the Animal Research Committee of the above-mentioned institution and all studies were performed under GLP guidelines.

Animal studies demonstrated the Micro Therapeutics Thrombolytic Brush Catheter to be a safe and efficacious device for percutaneous administration of pharmacologicals for dissolution of thrombus located in artificial A-V grafts.

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Results of Clinical Trials

Eighty-one patients with thrombosed artificial looped hemodialysis grafts were randomized at five institutions in the United States. Forty-five subjects were randomized to treatment with the Thrombolytic Brush Catheter and thirty-six were randomized to treatment with pulse-spray infusion. Initial success was defined as <20% residual thrombus in the graft. Following the lysis procedure (Thrombolytic Brush Catheter or pulse-spray infusion) patients underwent thrombectomy to remove residual clot and balloon angioplasty to treat stenotic lesions. Patients were followed for 4½ months post procedure to determine primary graft patency (the ability to dialyze with no further interventions). The results of this study are detailed in the table below.

Parameter	Thrombolytic BrushTreatment Group	Pulse-Spray InfusionControl Group	StatisticalComparison
Number of patients enrolled	45	36	n/a
Number of grafts treated	43	35	n/a
Duration of lytic procedure	17 minutes	28 minutes	Significant(p=.0001)
Residual thrombus after lytic procedure	6.5%	25.5%	Significant(p=.0001)
Urokinase dose used	215,435 Units	455,882 Units	Significant(p=.0001)
Heparin dose used	2,570 Units	4926 Units	Significant(p=.0001)
Acute success of lytic procedureGraft patent within 30 minutes	42/43 (98%)	15/35 (43%)	Significant(p=.0001)
Stenotic lesion visualized	41/41 (100%)(No Secondary Intervention2 patients)	33/33 (100%)(No Secondary Intervention2 patients)	Not Significant(p=1.000)
Thrombectomy performed to removeresidual thrombus	14/41 (34%)	14/33 (42%)	Not Significant(p=.481)
PTA performed to treat stenotic lesion	41/41 (100%)	32/32 (100%)1 Missing	Not Significant(p=1.000)
Residual thrombus after thrombectomyand/or PTA	2.2%	1.6%	Not Significant(p=.6607)
Duration of entire procedure	70 minutes	84 minutes	Not Significant(p=.1735)
Procedural success after all interventions'Graft patent, no major complications	39/43 (91%)	34/35 (97%)	Not Significant(p=.621)
Successful dialysis after all interventions	34/39 (87%)	30/34 (88%)	Lifetable analysis:Not significant'
Primary Patency at 3 months'	16/38 (42%)(No follow-up 1 patient)	15/31 (48%)(No follow-up 3 patients)	Lifetable analysis:Not significant'
Failures within 3 months(Rethrombosed/New Graft/Died/Transplant)	22/38 (58%)(No follow-up 1 patient)	16/31 (52%)(No follow-up 3 patients)	Lifetable analysis:Not significant'
Primary Patency at 4½ months²	14/38 (37%)(No follow-up 1 patient)	14/30 (47%)(No follow-up 4 patients)	Lifetable analysis:Not significant'
Failures within 4½ months(Rethrombosed/New Graft/Died/Transplant)	24/38 (63%)(No follow-up 1 patient)	16/30 (53%)(No follow-up 4 patients)	Lifetable analysis:Not significant'

'Procedure Failures (4 treatment group) were not included in the Lifetable analyses for primary patches calculations. "Patents who rethrombosed, had new grafts placed, died or received transplants were considered failures for the time of rethrombosis, death or intervention and at the subsequent follow-up interval(s).

'Lifetable analyses demonstrate no statistically significance between treatment and control for primary patency during the 41/2 month follow-up period

Conclusion: Clinical data demonstrate the Thrombolytic Brush Catheter is a safe, effective and rapid alternative to pulse-spray thrombolysis for patients with thrombosed hemodialysis access grafts.

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Image /page/3/Picture/1 description: The image is a black and white logo for the U.S. Department of Health & Human Services. The logo features a stylized design of three human profiles facing right, stacked on top of each other. The profiles are rendered in a flowing, abstract manner. The text "DEPARTMENT OF HEALTH & HUMAN SERVICES • USA" is arranged in a circular fashion around the profile design.

Food and Drug Administration 9200 Corporate Boulevard Rockville MD 20856

John L. Gehrich, Ph.D. Vice President, Requlatory and Clinical Affairs Micro Therapeutics, Inc. -1062-F Calle Neqocio San Clemente, California 92673

AUG - 8 1997

Re: K963925 Thrombolytic Brush Catheter and Motor Drive Regulatory Class: II (two) Product Code: MCW Dated: May 20, 1997 Received: May 21, 1997

Dear Dr. Gehrich:

We have reviewed your Section 510(k) notification of intent to market the device referenced above and we have determined the device is substantially equivalent (for the indications for use stated in the enclosure) to 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 (Act). You may, therefore, market the device, subject to the general controls provisions of the Act. 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.

If your device is classified (see above) into either class II (Special Controls) or class III (Premarket Approval), it may be subject to such additional controls. Existing major regulations affecting your device can be found in the Code of Federal Regulations, Title 21, Parts 800 to 895. A substantially equivalent determination assumes compliance with the Current Good Manufacturing Practice requirement, as set forth in the Quality System Regulation (QS) for Medical Devices: General regulation (21 CFR Part 820) and that, through periodic QS inspections, the Food and Drug Administration (FDA) will verify such assumptions. Failure to comply with the GMP regulation may result in regulatory action. In addition, FDA may publish further announcements concerning your device in the Federal Register. Please note: this response to your premarket notification submission does not affect any obligation you might have under sections 531 through 542 of the Act for devices under the Electronic Product Radiation Control provisions,

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or other Federal laws or requlations.

This letter will allow you to begin marketing your device as described in your 510(k) premarket notification. The FDA finding of substantial equivalence of your device to a legally marketed predicate device results in a classification for your device and thus, permits your device to proceed to the market.

If you desire specific advice for your device on our labeling requlation (21 CFR Part 801 and additionally 809.10 for in vitro diaqnostic devices), please contact the Office of Compliance at (301) 594-4648. Additionally, for questions on the promotion and advertising of your device, please contact the Office of Compliance at (301) 594-4639. Also, please note the regulation entitled, "Misbranding by reference to premarket notification" (21 CFR 807.97). Other general information on your responsibilities under the Act may be obtained from the Division of Small Manufacturers Assistance at its toll-free number (800) 638-2041 or (301) 443-6597 or at its internet address "http://www.fda.gov/cdrh/dsmamain.html".

Sincerely yours,

Thomas J. Callahan

Thomas J. Callahan, Ph.D. Director Division of Cardiovascular, Respiratory, and Neurological Devices Office of Device Evaluation Center for Devices and Radiological Health

Enclosure

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510(k) Number (if known):

Micro Therapeutics Thrombolytic Brush Catheter and Motor Drive Device Name:

Indications for Use:

Th. R.

(Division Sign-Off) Division of Cardiovascular, Respiratory, and Neurological Devi 510(k) Number

(PLEASE DO NOT WRITE BELOW THIS LINE-CONTINUE ON ANOTHER PAGE IF NEEDED)

Concurrence of DCRH, Office of Device Evaluation (ODE)

Prescription Use

Regulation Number and Section

§ 870.4875 Intraluminal artery stripper.

(a)
Identification. An intraluminal artery stripper is a device used to perform an endarterectomy (removal of plaque deposits from arterisclerotic arteries.)(b)
Classification. Class II (performance standards).