(140 days)
The AXIOS Stent with Electrocautery Enhanced Delivery System is indicated for use to facilitate transgastric or transduodenal endoscopic drainage of symptomatic pancreatic pseudocysts ≥ 6cm in size, with ≥ 70% fluid content that are adherent to the gastric or bowel wall. Once placed, the AXIOS Stent functions as an access port allowing passage of standard and therapeutic endoscopes to facilitate debridement, irrigation and cystoscopy. The stent is intended for implantation up to 60 days and should be removed upon confirmation of pseudocyst resolution.
The AXIOS Stent with Electrocautery Enhanced Delivery System is intended for the endoscopic placement of a flexible. MR conditional, fully-covered, self-expanding braided Nitinol stent for transgastric or transduodenal endoscopic drainage of symptomatic pancreatic pseudocysts. The AXIOS Stent with Electrocautery Enhanced Delivery System is comprised of two main components: (1) AXIOS Stent and (2) Electrocautery Enhanced Deliverv System.
The subject premarket notification describes modifications to the cleared AXIOS Delivery System to add electrocautery to facilitate precise access to anatomic targets as well as the staged placement of the currently cleared AXIOS Stent. The AXIOS Stent with Electrocautery Enhanced Delivery System incorporates the same identical implantable stent that is preloaded within the current AXIOS Delivery System (K123250). Both the AXIOS Stent and Delivery System were originally cleared under 510(k) K123250 and most recently under 510(k) K140561.
As with the non-cautery AXIOS devices, the Electrocautery Enhanced AXIOS Delivery System is compatible with commercially-available 0.035-inch endoscopic guidewires and intended to be used in the gastrointestinal tract in conjunction with commercially available echoendoscopes. The Electrocautery Enhanced Delivery System has been modified to connect with an off-the- shelf electrosurgical unit or generator that is compliant to IEC 60601-1-2 and IEC 60601-2-2. The generator must be installed and put into service according to the EMC information provided in the generator manufacturer's guidance and declaration for electromagnetic compatibility.
Cables and patient return electrodes that are specified by generator manufacturer must be used for connection.
The AXIOS Stent with Electrocautery Enhanced Delivery System is provided sterile, disposable and intended for single use. The Electrocautery Enhanced AXIOS Delivery System is IEC compliant.
Here's an analysis of the acceptance criteria and study findings for the AXIOS™ Stent with Electrocautery Enhanced Delivery System, based on the provided document:
Acceptance Criteria and Device Performance
The document does not explicitly present a table of formal acceptance criteria with numerical targets (e.g., sensitivity > X%, specificity > Y%). Instead, it describes various tests and their outcomes, indicating that the device "meets product design specifications" and "perform[s] in accordance with its intended use."
However, we can infer some performance metrics and safety outcomes that serve as de facto acceptance criteria from the "Summary of Clinical Tests Performed" section.
Table 1: Inferred Acceptance Criteria and Reported Device Performance
| Performance Metric / Acceptance Criterion (Inferred) | Reported Device Performance | Study Type |
|---|---|---|
| Safety: Freedom from major complications related to stent placement and removal (Safety outcome) | "Ninety percent (90%) of subjects were from major complications." | Clinical Study |
| Safety: No serious adverse events related to the device or index procedure | "Ninety-three percent (93.3%) of subjects experienced no serious adverse events related to the device or index procedure." | Clinical Study |
| Safety: No unanticipated events related to device use | "There were no unanticipated events related to the use of the device." | Clinical Study |
| Safety: No intraoperative adverse events during stent placement | "There were no intraoperative adverse events during AXIOS Stent placement..." | Clinical Study |
| Safety: No unanticipated complications or new risks related to implantation and removal | "There were no unanticipated complications or new risks related to the implantation and removal of the AXIOS Stent." | Clinical Study |
| Device Performance/Effectiveness: Successful implantation | "The AXIOS stent was successfully implanted in all study subjects (100%)." | Clinical Study |
| Device Performance/Effectiveness: Stent patency confirmed with drainage | "AXIOS stent patency was confirmed with drainage visualized for all stents placed." | Clinical Study |
| Device Performance/Effectiveness: Stent remained in position (no migration) at 30 or 60 days | "In subjects treated PP, 100% of AXIOS devices remained in position at 30 or 60 days..." | Clinical Study |
| Device Performance/Effectiveness: Stent lumen remained patent at 30 days | "...81.1% of stent lumens remained patent at 30 days..." | Clinical Clinical Study |
| Device Performance/Effectiveness: Stent lumen remained patent at 60 days | "...and 100% at 60 days." | Clinical Study |
| Device Performance/Effectiveness: Successful stent removal | "Successful removal of the AXIOS stent was achieved in all subjects (100%) in which endoscopic removal PP was attempted." | Clinical Study |
| Clinical Effectiveness: Overall clinical success | "Overall clinical success was achieved in 83.3% of subjects." | Clinical Study |
| Electrocautery Delivery System Performance: Performed as intended for access (100% of cases) | "The Electrocautery Enhanced Delivery System was used for access in 100% of patients and performed as intended in all cases." | Clinical Study |
| Electrocautery Safety: No adverse events or unanticipated adverse device effects attributed to electrocautery use | "There were no adverse events or unanticipated adverse device effects attributed to electrocautery use." | Clinical Study |
| Bench Performance: Device meets product design specifications and performs in accordance with intended use | "The nonclinical test results demonstrate that the modified device continues to meet product design specifications." | Non-Clinical Bench Testing |
| Biocompatibility: Device is biocompatible for intended use | "...the Electrocautery Enhanced Delivery System is biocompatible for the intended use." | Biocompatibility Testing |
| Electromagnetic Compatibility / Electrical Safety: Passes acceptance criteria outlined in relevant IEC standards | "All completed testing passed the acceptance criteria as outlined in IEC 60601-1, 60601-1-6, 60601-2-2, 60601-2-18, and ISO 14971..." | EMC/Electrical Safety Testing |
| Animal Study - Safety: Stents remained patent, no migration, healthy surrounding tissue | "None of the stents migrated from the original position and all stents remained patent during the implant period (1 month). The tissue surrounding the stent implant sites was healthy in all animals." | Animal Study |
| Animal Study - Safety: No apparent thermal heat effects grossly or histologically in AXIOS Electrocautery Enhanced Delivery System treated animals | "Thermal heat effects were not apparent grossly or histologically within the tissues evaluated in the AXIOS Electrocautery Enhanced Delivery System treated animals." | Animal Study |
| Animal Study - Effectiveness: Successful cautery access and stent deployment | "Cautery access and stent deployment using the AXIOS Stent with Electrocautery Enhanced Delivery System were compared to standard techniques... Access using cautery was successfully achieved and stents were successfully deployed in all animals." | Animal Study |
| Thermal Damage Comparison (Ex-Tissue): Less thermal damage compared to predicate device | "In all tissue samples, the Electrocautery Enhanced Delivery System caused statistically significant less thermal damage to the tissue as compared to the Cystotome." | Ex-Tissue Model |
Study Information
The document describes several types of studies: Nonclinical Bench Performance, Biocompatibility, Electromagnetic Compatibility/Electrical Safety, Animal Testing, and a Clinical Study.
1. Sample sizes used for the test set and data provenance:
-
Clinical Study (Effectiveness and Safety): The document states a "prospective multi-center, single-arm clinical study." It mentions "subjects" and provides percentages, but an exact number for the clinical test set (i.e., the number of patients in the study) is not explicitly given. It mentions "In subjects treated PP" (likely referring to Pancreatic Pseudocyst, but the full phrase is cut off), implying the entire study group.
- Data Provenance: Not specified, but "multi-center" suggests data from multiple locations, likely within one or more countries, but specific countries are not mentioned. It is a prospective study.
-
Animal Study: "The study animals" were used. A specific number is not provided, but it evaluated the 06x08mm and 20x10mm stent models.
- Data Provenance: Not specified, but it was a controlled animal study (porcine model).
-
Ex-Tissue Model: Not specified how many tissue samples were used, but it involved "porcine tissue."
- Data Provenance: Porcine tissue (ex-vivo).
2. Number of experts used to establish the ground truth for the test set and the qualifications of those experts:
- For the Clinical Study: The ground truth for outcomes (e.g., pseudocyst resolution, stent patency, adverse events) would typically be established by the treating physicians and study investigators, who are implied to be medical professionals (endoscopists, gastroenterologists). However, the number and specific qualifications of experts establishing "ground truth" (e.g., specific years of experience, board certification) are not explicitly stated in this document.
- For the Animal Study: "Histological evaluation... was performed." The qualifications of the individuals performing the histological evaluation are not stated.
3. Adjudication method (e.g., 2+1, 3+1, none) for the test set:
- The document does not mention a specific adjudication method using multiple experts for the clinical or animal study outcomes (e.g., 2+1, 3+1 consensus). Clinical trial data generally involves verification by investigators, but formal independent adjudication by multiple blinded readers is not described.
4. If a Multi-Reader Multi-Case (MRMC) comparative effectiveness study was done, and if so, what was the effect size of how much human readers improve with AI vs without AI assistance:
- No MRMC comparative effectiveness study was done. This device is a stent and delivery system, not an AI-powered diagnostic tool that assists human readers in interpreting medical images. Therefore, the concept of "human readers improve with AI vs without AI assistance" is not applicable here.
5. If a standalone (i.e., algorithm only without human-in-the-loop performance) was done:
- This question is not applicable as the device is an interventional medical device (stent and delivery system), not an algorithm or AI system.
6. The type of ground truth used (expert consensus, pathology, outcomes data, etc.):
- Clinical Study: The ground truth for effectiveness was based on clinical outcomes data (pseudocyst resolution, stent patency, stent position, successful implantation/removal) and safety outcomes data (adverse events, complications). These would likely be assessed by treating physicians and investigators.
- Animal Study: The ground truth involved histopathological evaluation of tissues, gross evaluation of implant sites, and direct observation of device performance (successful access, stent deployment, patency, migration).
- Ex-Tissue Model: The ground truth involved measurement of thermal damage on porcine tissue.
7. The sample size for the training set:
- Not applicable. This document describes the testing of a medical device (stent and delivery system), not a machine learning algorithm that requires a "training set." The device itself undergoes rigorous design verification and validation, but there isn't a "training set" in the AI/ML sense.
8. How the ground truth for the training set was established:
- Not applicable as there is no training set for this type of medical device submission.
§ 876.5015 Pancreatic drainage stent and delivery system.
(a)
Identification. A pancreatic drainage stent is a prescription device that consists of a self-expanding, covered, metallic stent, intended for placement to facilitate transmural endoscopic drainage of pancreatic pseudocysts. This stent is intended to be removed upon confirmation of pseudocyst resolution. This device may also include a delivery system.(b)
Classification. Class II (special controls). The special controls for this device are:(1) The device and elements of the delivery device that may contact the patient must be demonstrated to be biocompatible.
(2) Performance data must demonstrate the sterility of patient-contacting components of the device.
(3) Performance data must support the shelf life of the device by demonstrating continued sterility, package integrity, and device functionality over the requested shelf life.
(4) Non-clinical testing data must demonstrate that the stent and delivery system perform as intended under anticipated conditions of use. The following performance characteristics must be tested:
(i) Deployment testing of the stent and delivery system must be conducted under simulated use conditions.
(ii) Removal force testing must be conducted. The removal force testing must demonstrate that the stent can be safely removed, and that the stent will remain in place when subjected to forces encountered during use.
(iii) Expansion force testing must be conducted. The expansion force must demonstrate that the forces exerted by the stent will not damage the tissue surrounding the stent.
(iv) Compression force testing must be conducted. The compression force must demonstrate that the stent will withstand the forces encountered during use.
(v) Dimensional verification testing must be conducted.
(vi) Tensile testing of joints and materials must be conducted. The minimum acceptance criteria must be adequate for its intended use.
(vii) Fatigue testing must be conducted. Material strength must demonstrate that the stent will withstand forces encountered during use.
(viii) Corrosion testing must be conducted. Corrosion resistance must demonstrate that the stent will withstand conditions encountered during use.
(5) Non-clinical testing must evaluate the compatibility of the stent in a magnetic resonance (MR) environment.
(6) Well-documented clinical experience must demonstrate safe and effective use, and capture any adverse events observed during clinical use.
(7) Labeling must include the following:
(i) Appropriate instructions, warnings, cautions, limitations, and information related to the safe use of the device, including deployment of the device, maintenance of the drainage lumen, and removal of the device.
(ii) A warning that the safety and patency of the stent has not been established beyond the duration of the documented clinical experience.
(iii) Specific instructions and the qualifications and clinical training needed for the safe use of the device, including deployment of the device, maintenance of the drainage lumen, and removal of the device.
(iv) Information on the patient population for which the device has been demonstrated to be effective.
(v) A detailed summary of the clinical experience pertinent to use of the device.
(vi) A detailed summary of the device technical parameters.
(vii) A detailed summary of the device- and procedure-related complications pertinent to use of the device.
(viii) An expiration date/shelf life.