(187 days)
The truFreeze System is indicated for use as a cryosurgical tool in the fields of dermatology, gynecology, and general surgery, to ablate benign (e.g. Barrett's Esophagus with high grade dysplasia) and malignant lesions.
The truFreeze system is a cryosurgical tool that applies medical-grade liquid nitrogen to the ablation area via a small, low pressure, open tipped catheter. The truFreeze System consists of a console and a disposable spray kit.
Console:
The console is the central interface of the system and is comprised of a touch panel computer (TPC) and cryogen, suction, and electronics modules packaged in a mobile cart. Users interact with the console through a dual foot pedal and a touch panel. An off-the-shelf controller and associated software manage the cryogen level sensing, filling, pressure, cooling, defrost, suction, timing and data management functions. A fill kit, stored on the rear of the console, allows for liquid nitrogen transfer from the source tank to the console. Safety features include indicators, tank pressure relief valves, an isolated low voltage power system, and an emergency button to be used in the event of user or technical malfunction. The console is the same as previously cleared for the predicate truFreeze System (K162695). Therefore, there are no new issues of safety or effectiveness raised.
Disposable spray kit:
There are 2 types of spray kits available. One kit is available for active venting procedures and one is available for passive venting procedures. Both active and passive venting kits are provided in a carton of five (5) individually packaged sterile, single-use catheters with introducers in individual pouches. Additionally, the active venting kit is provided with includes a carton of five (5) individually packaged sterile, single-use CDTs with associated tubing in individual pouches. Each carton within a spray kit contains the instructions for use. The disposable kit is the same as previously cleared for the predicate truFreeze System (K162695). Therefore, there are no new issues of safety or effectiveness raised.
Although the provided text heavily details the device and its testing, it does not contain acceptance criteria in the format of a table with specific metrics and thresholds. Instead, it presents a clinical study's results with the claim of "substantial equivalence" to predicate devices. Therefore, I cannot construct the requested table of acceptance criteria and reported device performance directly from the text.
However, I can extract and structure all other requested information about the study that proves the device meets its expanded indications.
Here's an analysis of the provided text, addressing your points:
1. A table of acceptance criteria and the reported device performance
The document does not provide a table of pre-defined acceptance criteria with specific numerical thresholds. It relies on a "substantial equivalence" argument, comparing the device's performance (safety and efficacy) to existing predicate devices and literature.
Implicit "Performance Metrics" and Reported Performance (derived from results):
| Performance Metric (Derived) | Reported Device Performance (truFreeze System, BE-HGD Efficacy Population) |
|---|---|
| Efficacy: Complete Eradication of Dysplasia (CE-D) | 87.0% (40 out of 46 CE-D patients) |
| Safety: Stricture Rate (per patient) | 2.7% (3 out of 111 safe population patients) |
| Safety: Pancreatitis Rate (per patient) | 0.9% (1 out of 111 safe population patients) |
| Safety: Procedure-Related Stricture Rate (per procedure session) | 1.2% (3 out of 258 safe population procedures) |
| Safety: Procedure-Related Pancreatitis Rate (per procedure session) | 0.4% (1 out of 258 safe population procedures) |
Note on "Acceptance Criteria": The concluding statement in the "Discussion" section mentions: "This success rate is comparable to the success rate for the Barrx System and the Coldplay CryoBalloon™ Focal Ablation System among all phenotypes of BE patients, ranging from no dysplasia to early adenocarcinoma and across 3 different ablation doses." This suggests that the "acceptance criterion" was achieving a comparative efficacy and safety profile to these established devices, rather than a fixed numerical threshold.
2. Sample size used for the test set and the data provenance
- Test Set (Clinical Study Population):
- Safety Population: 111 patients
- Efficacy Population: 46 patients (a subset of the safety population, meeting specific inclusion/exclusion criteria for BE-HGD)
- Data Provenance:
- Country of Origin: Not explicitly stated, but the FDA submission suggests it's likely a US-based study given the regulatory context.
- Retrospective or Prospective: "This post-marketing registry prospectively collected data on patients treated with the FDA-cleared cryotherapy device (truFreeze® System)." So, it was prospective.
3. Number of experts used to establish the ground truth for the test set and the qualifications of those experts
The document does not specify the number or qualifications of experts used to establish the ground truth (e.g., histology results for Barrett's Esophagus with high-grade dysplasia). It merely states that there were "pre-therapy and post-therapy histology."
4. Adjudication method (e.g. 2+1, 3+1, none) for the test set
The document does not specify any adjudication method for the test set's ground truth assessment.
5. If a multi reader multi case (MRMC) comparative effectiveness study was done, If so, what was the effect size of how much human readers improve with AI vs without AI assistance
This section is not applicable. The device is a cryosurgical tool, not an AI-powered diagnostic or assistive tool for human readers. Therefore, an MRMC study related to human reader improvement with AI assistance was not conducted.
6. If a standalone (i.e. algorithm only without human-in-the-loop performance) was done
This section is not applicable. The device is a physical surgical intervention tool, not an algorithm. Its performance is measured by clinical outcomes (ability to ablate lesions, safety profile), not by an algorithm's standalone performance.
7. The type of ground truth used (expert consensus, pathology, outcomes data, etc)
The primary ground truth for efficacy was established through histology (pathology): "Patients without a pre-therapy and post-therapy histology" was an exclusion criterion for the efficacy population. The outcome measured was "Complete Eradication of Dysplasia (CE-D)," which relies on pathological confirmation.
8. The sample size for the training set
This section is not applicable. The truFreeze System is a cryosurgical device, not a machine learning algorithm that requires a "training set." The clinical data presented is for validation of its expanded indications.
9. How the ground truth for the training set was established
This section is not applicable as there was no "training set" for an algorithm.
§ 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.