(87 days)
Compound W® Nitro-Freeze is intended for over-the-counter treatment of common warts and plantar warts in adults and children four years of age or older.
Compound W® Nitro-Freeze is a pen-like cryogenic device that utilizes pressurized nitrous oxide (N,O, liquefied) to destroy wart tissue through evaporative cooling when the cryogen is delivered via a disposable foam applicator tip. Each Compound W® Nitro-Freeze device is supplied in an outer carton with an Instructions-for-Use leaflet and a bag containing replacement tips.
The document describes the device Compound W® Nitro-Freeze, an over-the-counter cryogenic wart remover. The following summarizes the acceptance criteria and study information:
1. Table of Acceptance Criteria and Reported Device Performance
The document does not explicitly present a formalized table of acceptance criteria. Instead, substantial equivalence to legally marketed predicate devices (Wartner® Wart Removal System (K032271) and Wartie® Wart Remover (K140314)) is claimed based on comparable intended use, technological characteristics, and safety/effectiveness data. The performance is reported in terms of freezing temperature and clinical effectiveness.
| Acceptance Criteria (Implied) | Reported Device Performance (Compound W® Nitro-Freeze) | Reference Performance (Predicates) |
|---|---|---|
| Freezing Performance (Bench Test; after 40 sec.) | -82.83°C | Wartner: -33.06°C; Wartie: -24.01°C; Urgo: -1.93°C |
| Pressure Release Feature | No devices disarmed at 35°C; All disarmed at either 38°C, 40°C or 50°C. | Not explicitly compared to predicates, but confirmed to function as intended. |
| Overall Wart Clearance (Clinical Study) | 82.0% (after final treatment) | Wartner: 47.4%; Wartie: 52.8% |
| First-Treatment Wart Clearance (Clinical Study) | 34.0% | Wartner: 10.5%; Wartie: 13.9% |
| Serious Product-Related Adverse Events | None recorded | Not explicitly detailed for predicates, but implied to be comparable |
| Non-Serious Adverse Events (e.g., blistering, pain, burning) | Increase compared to predicates, but considered offset by increased effectiveness | Predicates' specific rates not detailed, but implied to be lower |
2. Sample Size Used for the Test Set and Data Provenance
- Sample Size (Clinical Study): 138 patients randomized, with 124 per-protocol.
- Nitro-Freeze arm: 50 patients
- Wartner arm: 38 patients
- Wartie arm: 36 patients
- Data Provenance: The document does not explicitly state the country of origin for the clinical study data. It mentions "a single-center... study," but the location of this center is not specified. The study is described as a "multi-arm study," indicating a prospective design (patients were enrolled and treated).
3. Number of Experts Used to Establish the Ground Truth for the Test Set and Qualifications
This information is not provided in the document. The document mentions "evaluator assessments" following treatments in the clinical study, but does not specify the number or qualifications of these evaluators or how "ground truth" (i.e., wart clearance) was established, aside from the term "cured."
4. Adjudication Method
This information is not provided in the document.
5. Multi Reader Multi Case (MRMC) Comparative Effectiveness Study
An MRMC comparative effectiveness study was not conducted for this device. The clinical study was a direct comparison of the device's effectiveness against predicate devices in treating warts in human subjects, not a study evaluating human reader performance with or without AI assistance.
6. Standalone Performance Study
A standalone, algorithm-only performance study was not conducted as this is a physical medical device (cryogenic wart remover), not an AI/software as a medical device.
7. Type of Ground Truth Used
For the clinical performance data, the ground truth was based on clinical assessment of wart clearance, described as "cured" after a certain number of treatments.
8. Sample Size for the Training Set
This information is not applicable/not provided. The device is an over-the-counter physical cryogenic wart remover, not a machine learning algorithm that requires a training set.
9. How the Ground Truth for the Training set Was Established
This information is not applicable as there is no training set for this type of device.
§ 878.4350 Cryosurgical unit and accessories.
(a)
Identification —(1)Cryosurgical unit with a liquid nitrogen cooled cryoprobe and accessories. A cryosurgical unit with a liquid nitrogen cooled cryoprobe and accessories is a device intended to destroy tissue during surgical procedures by applying extreme cold.(2)
Cryosurgical unit with a nitrous oxide cooled cryoprobe and accessories. A cryosurgical unit with a nitrous oxide cooled cryoprobe and accessories is a device intended to destroy tissue during surgical procedures, including urological applications, by applying extreme cold.(3)
Cryosurgical unit with a carbon dioxide cooled cryoprobe or a carbon dioxide dry ice applicator and accessories. A cryosurgical unit with a carbon dioxide cooled cryoprobe or a carbon dioxide dry ice applicator and accessories is a device intended to destroy tissue during surgical procedures by applying extreme cold. The device is intended to treat disease conditions such as tumors, skin cancers, acne scars, or hemangiomas (benign tumors consisting of newly formed blood vessels) and various benign or malignant gynecological conditions affecting vulvar, vaginal, or cervical tissue. The device is not intended for urological applications.(b)
Classification. Class II.