(267 days)
The proposed device is intended to facilitate the passage of urine from the kidney to the bladder.
The Microvasive® Temporary Ureteral Drainage Stent is 6 Fr x 26.5 cm, with an open-ended coil at each end. The stent is an extruded polymeric tube made of a reversible cross-linked alginate polymer with an incorporated radiopacifier. The device is placed, using standard ureteral stent placement techniques that can be placed transurethrally, percutaneously or via open surgery using endoscopic and/or radiographic techniques.
Here's an analysis of the acceptance criteria and study details for the Boston Scientific/Microvasive Temporary Ureteral Drainage Stent (TUDS) based on the provided text:
1. Table of Acceptance Criteria and Reported Device Performance:
| Acceptance Criteria Category | Specific Metric | Acceptance Criteria (Implied/Direct) | Reported Device Performance (TUDS) |
|---|---|---|---|
| Effectiveness | Primary Effectiveness Endpoint: Study Success | "adequate short term drainage defined as the presence of the stent in the ureter and the lack of surgical or other intervention to treat symptoms on the stented side during the first 48 hours following placement." (The exact quantitative hurdle for "acceptable" isn't explicitly stated but the performance against it is given as the study outcome.) | 78.2% (68/87). (17 absence of stent and 3 interventions occurred within the first 48 hours; 1 patient had both an absence of stent and intervention.) |
| Alternate Endpoint: Overall Clinical Success (90-day follow-up) | "adequate drainage with no intervention (regardless of stent presence) and no definitely device-related serious adverse events (SAEs) throughout the 90 day follow-up period." (Again, the quantitative threshold for "acceptable" isn't explicitly stated, but the performance against it is given.) | 94.3% (83/88) with the 90-day study period. | |
| Safety | Primary Safety Endpoint: Assessment of Adverse Events | "Assessment of adverse events (incidence, relationship to device, severity)" compared to published clinical studies of plastic ureteral stents. (The implicit criteria is that adverse event profiles should be comparable or improved, and there should be no unanticipated events.) | No unanticipated adverse events reported. All adverse events resolved by the end of the study without any permanent sequelae. Key findings include: - Flank pain/loin discomfort: 12.5% (11/88) - Hydronephrosis: 3.4% (3/88) - Suprapubic pain/lower abdominal pain: 8% (7/88) - Urinary frequency: 51.8% (44/85) at day 1 - Urinary urgency: 67% (59/88) at baseline - Urethral discomfort: 27.9% (24/86) at day 1- Stent migration: 19.5% (17/87) (but only 3.4% required intervention)- Additional stent specific procedures: 3.4% (3/88) through 48 hrs; 8.0% (7/88) through 90 days. |
| Device Characteristics | Successful Placement | Not an explicit acceptance criterion, but a measure of initial procedural success. | 98.9% (88/89) (1 patient required 2 stents). |
| Time to eliminate TUDS from ureter | Not an explicit acceptance criterion, but a characteristic of the device. | Mean = 13.0 (±11.3) days, Median = 8 days. | |
| Time to eliminate TUDS from body | Not an explicit acceptance criterion, but a characteristic of the device. | Mean = 21.0 (±17.8) days, Median = 15 days. | |
| Retained stent fragments at 90 days in renal pelvis | Not an explicit acceptance criterion, but a safety concern. | 3.4% (3/87). (Of these, 2 had successful ESWL, 1 declined intervention and was asymptomatic). | |
| Tolerability (Moderate to most severe pain) | Not an explicit acceptance criterion, but a measure of patient experience. | Day 1: Flank pain - 23.0% (20/87), Urethral pain - 27.9% (24/86). Day 30: Flank pain - 8.7% (7/80), Urethral pain – 2.5% (2/80). | |
| Patient Satisfaction | Not an explicit acceptance criterion, but a measure of patient experience. | 88.8% satisfied (71/80). |
2. Sample Size Used for the Test Set and Data Provenance:
- Sample Size: 88 patients were enrolled and had the TUDS placed. 87 were evaluable for the "Study success" endpoint, and 88 for "Overall clinical success."
- Data Provenance: The study was a prospective, single-arm, multi-center trial conducted across 6 investigative sites. The text does not specify the country of origin, but "Boston Scientific/ Microvasive, One Scientific Place, Natick, MA" suggests a US-based sponsor, and "FDA's Draft Guidance Ureteral Stents was utilized" (Section V), and the FDA 510(k) submission and approval letter, strongly imply the study was conducted to satisfy US regulatory requirements, likely within the US or under clinical trial regulations accepted by the FDA.
3. Number of Experts Used to Establish the Ground Truth for the Test Set and Qualifications of Those Experts:
- The study involved clinical assessments by medical professionals at various investigative sites (6 sites). These assessments included device presence, position, morphology (via KUB films), and evaluation of adverse events. Also, normal renal function was assessed by Intravenous Pyelogram (IVP) at 30 days.
- The document does not explicitly state the number or specific qualifications of individual experts (e.g., radiologists, urologists) who established the "ground truth" for each patient's condition or imaging interpretation. The data comes from direct clinical observations, imaging results (KUB, IVP) interpreted by clinical staff at the study sites, and formal capture of adverse events by the investigators.
4. Adjudication Method for the Test Set:
- The document does not describe a formal adjudication method (e.g., 2+1, 3+1, none) for the test set. Clinical outcomes, imaging results, and adverse events were presumably recorded by the treating physicians/staff at each center and then collected and analyzed by the study sponsor. There is no mention of independent expert review or a consensus panel.
5. Multi-Reader Multi-Case (MRMC) Comparative Effectiveness Study:
- No, an MRMC comparative effectiveness study was not done. This was a single-arm study evaluating the safety and effectiveness of the TUDS device in facilitating short-term drainage. It did not involve comparing human readers' performance with and without AI assistance.
6. Standalone (i.e., algorithm only without human-in-the-loop performance) Study:
- Not applicable. This device (Temporary Ureteral Drainage Stent) is a physical medical device, not an algorithm or AI system. Therefore, the concept of "standalone algorithm performance" is not relevant. The study evaluates the performance of the physical stent in patients.
7. Type of Ground Truth Used:
- The ground truth was established through a combination of clinical observation, diagnostic imaging (KUB films, Intravenous Pyelogram - IVP), and documented patient outcomes/adverse events.
- "Study success" relied on the presence of the stent in the ureter (observable via KUB) and the absence of surgical or other intervention for symptoms.
- "Overall clinical success" relied on adequate drainage (clinical judgment, potentially supported by imaging) and the absence of device-related serious adverse events documented through follow-up.
- Adverse events were based on clinical assessments and patient reporting during follow-up visits.
- Stent presence/position/morphology was assessed via radiological assessments (KUB films).
- Normal renal function was assessed by IVP.
8. Sample Size for the Training Set:
- Not applicable. As this is a study for a physical medical device and not an AI/ML algorithm, there is no "training set" in the context of machine learning. The study itself served as the primary clinical evidence for regulatory submission.
9. How the Ground Truth for the Training Set Was Established:
- Not applicable. (See point 8).
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AUG 0 8 2002
| Section V. 510(k) SUMMARY of Safety and Effectiveness | |
|---|---|
| Sponsor: | Boston Scientific/ MicrovasiveOne Scientific PlaceNatick, MA 01760-1537 |
| Contact Person: | Janet A. McGrathSr. Global Regulatory Affairs SpecialistORLorraine M. HanleyDirector, Global Regulatory Affairs |
| Submission Date: | October 31, 2001 |
| Common/Usual Name: | Ureteral Stent, Indwelling Ureteral Catheter |
| Trade/Proprietary Name: | To Be Determined |
| Device Classificationand Name: | Class II: Ureteral Stent, 21CFR 876.4620 |
| Indications for Use: | The proposed device is intended to facilitate the passage of urine fromthe kidney to the bladder. |
| SubstantialEquivalence: | The proposed device is substantially equivalent to ureteral stentsclassified by the Code of Federal Regulations 21CFR 876.4620 andFDA product code 78FAD, based on a review of the FDA's 510(k)Decision-making Process. |
| Product Testing: | To determine appropriate testing for the device, FDA's Draft GuidanceUreteral Stents was utilized. The functional bench test resultsdemonstrate that the proposed device is substantially equivalent to thepredicate devices in terms of characteristics tested. The proposeddevice meets the biocompatibility requirements of ISO 10993 for itsintended use. A clinical trial involving 88 patients was conducted onthe placement of the TUDS device. |
| Device Description: | The Microvasive® Temporary Ureteral Drainage Stent is 6 Fr x 26.5cm, with an open-ended coil at each end. The stent is an extrudedpolymeric tube made of a reversible cross-linked alginate polymer withan incorporated radiopacifier. The device is placed, using standardureteral stent placement techniques that can be placed transurethrally,percutaneously or via open surgery using endoscopicand/orradiographic techniques. |
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Clinical Studies
The purpose of the clinical study to evaluate the safety and effectiveness of the Microvasive™ Temporary Ureteral Drainage Stent (TUDS) to facilitate short-term drainage of fluid from the kidney to the bladder.
The clinical study was designed as a prospective, single-arm, multi-center trial. The study included 6 investigative sites that could enroll a maximum of 88 total subjects. Each subject had only one TUDS placed following uncomplicated ureteroscopy.
Subjects with a TUDS successfully placed underwent assessments for device presence, position, and morphology at 1, 2, 7 and 14 days post placement. The exams at days 7 and 14 were not required, if there was no evidence of the TUDS at the preceding exam. All subjects in whom a TUDS was successfully placed were assessed at 30 days to evaluate normal renal drainage on the affected side and assess possible adverse events. If the device was still present in the urological system at day 30, the patient was evaluated at day 60 and day 90.
The study had two primary endpoints:
-
. Primary effectiveness endpoint -
Study success defined as adequate short term drainage defined as the presence of the stent in the ureter and the lack of surgical or other intervention to treat symptoms on the stented side during the first 48 hours following placement. -
. Primary safety endpoint -
Assessment of adverse events (incidence, relationship to device, severity) -
. Alternate Endpoint-
Overall clinical success was also calculated and was defined as adequate drainage with no intervention (regardless of stent presence) and no definitely device-related serious adverse events (SAEs) throughout the 90 day follow-up period.
Study
A total of 88 patients had the TUDS placed following uncomplicated ureteroscopy. All patients were ≥ 18 years of age and required short-term stenting to facilitate drainage.
Radiological assessments (i.e., KUB films) for presence, position, and morphology of the device and assessment of adverse events were performed at the scheduled follow-up visits. All subjects were also assessed at 30 days post-placement to evaluate normal renal function by intravenous pyelogram (IVP) on the affected side and to assess adverse events.
A total of 88 patients had the TUDS placed. The study period was 30 days for those patients who successfully passed the TUDS within 30 Days. If the stent remained present at the day 30 follow-up visit, the patient returned for Day 60 and Day 90 follow-up visits for additional monitoring.
There were no deaths among the TUDS patients studied. There were no reported unanticipated adverse events. Adverse events reported for the TUDS patients were similar to those reported in the literature for plastic ureteral stents. See Tables in the Adverse Events section for a listing of the adverse events observed in the study patients. Mean time to eliminate the TUDS from the body was 21 days. Warning: Clinical study shows that stent fragments may remain in the urinary system for over 90 days and may require removal.
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Study success was found to be 78.2% (68/87; 17 absence of stent and 3 interventions occurred, within the first 48 hours; 1 patient had both an absence of stent and intervention). The Alternate Endpoint, Overall clinical success was found to be 94.3% (83/88) with the 90 day study period. Tables 1 to 3 summarize the demographic, follow-up study visits, and clinical endpoint results for the TUDS study.
| Category | Value ± SD, (range), n=88 |
|---|---|
| Gender (%male) | 65.9%(58 male, 30 females) |
| Age | 44.8±13.1(18.0, 73.0) |
| Height (in) | 68.4±4.4(58.0, 76.0) |
| Weight (lb) | 186±42.8(95.0, 300.0) |
| Body Mass Index | 27.8±4.9(19.0, 42.0) |
Table 1 Demographic Information
Table 2 Follow-up patient information for: Device is out of the Ureter and Kidney Device is out of the Body
| Follow-Up Visit | Device is out of theUreter and Kidney | Device is out of the Body |
|---|---|---|
| Baseline | 0 | 0 |
| Day 1 | 9 | 0 |
| Day 2 | 7 | 3 |
| Day 7 | 22 | 22 |
| Day 14 | 24 | 31 |
| Day 30 | 14 | 15 |
| Day 60 | 4 | 6 |
| Day 90 | 0 | 0 |
| > 90 | 7 | 7 |
| Unscheduled visit | 0 | 4 |
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| Clinical Endpoint Results | |
|---|---|
| Endpoint | Result |
| Successful placement1 | 98.9% (88/89)* |
| Study success2 | 78.2% (68/87) |
| Overall clinical success3 | 94.3% (83/88) |
| Males with Early Migration | 12.1% (7/58) |
| Females with EarlyMigration | 34.5% (10/29) |
| Time required to eliminateTUDS from ureter | 13.0 (±11.3) daysMedian = 8 days |
| Time required to eliminateTUDS from body | 21.0 (±17.8) daysMedian = 15 days |
| Retained stent fragments at90 days in renal pelvis | 3.4% (3/87)^ |
| Tolerability of TUDS4(Moderate to most severepain) | Day 1: |
| Flank pain - 23.0% (20/87) | |
| Urethral pain - 27.9%(24/86) | |
| Day 30:Flank pain - 8.7% (7/80)Urethral pain – 2.5% (2/80) | |
| Patient satisfaction5 | 88.8% satisfied (71/80) |
Table 3
- (1) patient required (2) stents
Successful placement of TUDS device
2 Study success defined as adequate short term drainage defined as the presence of the stent in the ureter and the lack of surgical or other intervention to treat symptoms on the stented side during the first 48 hours following placement.
3 Alternate Endpoint Defined as adequate drainage with no intervention (regardless of stent presence) and no definitely device-related serious adverse events (SAEs) throughout the 90 day follow-up period.
4 Tolerability of the TUDS passage through the urinary tract when compared to uretharal discomfort recorded at baseline
a courted and and with the stent and with elimination of the stent from the urinary tract
^ Of the 3 patients with retained stent fragments. 2 patients elective ESWL treatments which were successful and 1 patient declined intervention and is being monitored by her physician. All of these patients were free of retentive symptoms.
The Primary Safety Endpoint: Assessment of adverse events (compared to published clinical studies of plastic ureteral stents), indicated that there were no unanticipated adverse events reported and all adverse events resolved by the end of the study without any permanent sequelae. A list of reported adverse events is presented in Table 4.
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| Reported Adverse Events | ||
|---|---|---|
| Adverse event | Literature range | TUDS study |
| Flank pain/Loin Discomfort | 17 - 50% | 12.5% n=11/88 at 1-30 days |
| Flank pain when voiding | 15-54% | 0% reported |
| Hydronephrosis | up to 25% | 3.4% n=3/88 at 2, 7 and 90 days |
| Suprapubic pain/lower abdominal pain | 20 - 50% | 8% n=7/88 at 1-30 days |
| Suprapubic pain when voiding | 49% | 0% reported |
| Trigonal irritation | 19% | 0% reported |
| Urinary frequency | 42 - 85% | 51.8% n= 44/85 at day 149.1% n= 28/57 at day 14 |
| Nocturia | 43-56% | 0% reported |
| Urinary urgency | 8 - 59% | 67% n= 59/88 at baseline54.8% n= 46/84 at day 1 |
| Dysuria | 31-40% | 0% reported |
| Urethral discomfort | - | 22.7% n= 20/88 at baseline27.9% n= 24/86 at day 15.3 n= 3/57 at day 14 |
| Incontinence | 3% | 2.3% n=2/88 at 7 days |
| Hematuria | 40 - 64% | 1.1% n=1/88 at day 1 |
| Stent migration | 3 - 10% | 19.5%* n= 17/873.4%* n= 3/87 |
| Stent encrustation | up to 10% | 0% reported |
| Stent/Ureteral Obstruction | 2.3% n=2/88 at 2 and 14 days | |
| Stent fracture | 0.6% | 0% reported |
| UTI | 3 - 35% | 2.3% n= 2/88 at 30 days |
| Bacteriuria | 29.9% | 0% reported |
| Additional stent specific procedures | up to 10% | 3.4% n=3/88 thru 48 hrs8.0% n=7/88 thru 90 days |
| Extravasation | - | 0% |
| Hemorrhage | - | 0% |
| Sepsis | - | 0% |
| Ureteral Reflux | - | 0% |
| Perforation of urinary tract | - | 0% |
| Peritonitis | - | 0% |
| Loss of renal function | - | 0% |
| Stone Formation | - | 0% |
| Urinary Retention | - | 0% |
| Stent fragment retention in | - | 0% |
Table 4
*Even though seventeen (19.5%) of the 87 evaluable patients studied had an early migration of their TUDS device, only three (3.4%) of the 87 evaluable patients needed intervention for symptoms following the stent migration. Adverse events related to interventions within the first 48 hours;
1 patient left flank pain, received IV pain medication .
1 patient right flank pain, hydronephosis, received IV pain medication ● .
1 patient left flank pain, stent repositioned by cystoscopy
Adverse events related to interventions after 48 hours;
- 1 patient left flank pain, ureteroscopy •
1 patient right distal ureteral obstruction, cystoscopy .
Note: By definition, there were no migrations after 48 hours of TUDS indwell (i.e., late migrations) since the stent is expected to degrade and pass out of the ureter after 48 hours.
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Image /page/5/Picture/0 description: The image shows the logo for the Department of Health & Human Services - USA. The logo is a circular seal with the department's name around the perimeter. Inside the circle is an abstract image of an eagle.
Food and Drug Administration 9200 Corporate Boulevard Rockville MD 20850 .
AUG 0 8 2002
Ms. Janet A. McGrath Specialist, Global Regulatory Affairs Boston Scientific Corporation Microvasive Urology One Boston Scientific Place NATICK MA 01760
Re: K013784
Trade/Device Name: Temporary (dissolvable) Ureteral Drainage Stent (TUDS) Regulation Number: 21 CFR 876.4620 Regulation Name: Ureteral stent Product Code: 78 FAD Regulatory Class: II Dated: May 30, 2002 Received: May 31, 2002
Dear Ms. McGrath:
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 (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. 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 (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.
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); good manufacturing practice requirements as set forth in the quality systems (OS) regulation (21 CFR Part 820); and if applicable, the electronic product radiation control provisions (sections 531-542 of the Act); 21 CFR 1000-1050.
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Page 2
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 regulation (21 CFR Part 801), please contact the Office of Compliance at one of the following numbers, based on the regulation number at the top of this letter:
| 8xx.1xxx | (301) 594-4591 |
|---|---|
| 876.2xxx, 3xxx, 4xxx, 5xxx | (301) 594-4616 |
| 884.2xxx, 3xxx, 4xxx, 5xxx, 6xxx | (301) 594-4616 |
| 892.2xxx, 3xxx, 4xxx, 5xxx | (301) 594-4654 |
| Other | (301) 594-4692 |
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 Part 807.97). Other general information on your responsibilities under the Act may be obtained from the Division of Small Manufacturers, International and Consumer Assistance at its toll-free number (800) 638-2041 or (301) 443-6597 or at its Internet address http://www.fda.gov/cdrh/dsma/dsmamain.html.
Sincerely yours,
Nancy C. Brogdon
Nancy C. Brogdon Director, Division of Reproductive, Abdominal, and Radiological Devices Office of Device Evaluation Center for Devices and Radiological Health
Enclosure
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Section I-C. Indications For Use Statement
510(K) Number:
Ureteral Stent
Device Name:
Indications For Use:
The proposed device is intended to facilitate the passage of urine from the kidney to the bladder.
(PLEASE DO NOT WRITE BELOW THIS LINE - CONTINUE ON ANOTHER PAGE IF NEEDED)
Concurrence of CDRH, Office of Device Evaluation (ODE)
Prescription Use
0 r
Over-The-Counter Use _________________________________________________________________________________________________________________________________________________________
(Per 21 CFR 801.109)
(Optional Format 1-2-96)
11
Nancy C Brogdon
(Division Sign-Off)
Division of Reproductive, Abdominal,
and Radiological Devices
510(k) Number K01378
Premarket Notification Ureteral Stent November 12, 20
§ 876.4620 Ureteral stent.
(a)
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.(b)
Classification. Class II (performance standards).