A Prospective CohorT Study of HandX - Assisted ENdoscopic MAstectomy: Feasibility and Safety (ATHENA I Study) (ATHENA I)

December 5, 2025 updated by: Vasileios Kalles

This study aims to learn whether a handheld robotic device, called the HandX, can help surgeons safely perform a minimally invasive nipple-sparing mastectomy. This type of mastectomy uses a small incision at the side of the breast to remove breast tissue while keeping the skin and nipple in place. The goal is to lower scarring, improve comfort, and support good cosmetic results after surgery.

Participants in this study will already be planning to have a therapeutic or preventive mastectomy with immediate implant-based reconstruction. All surgeries are done at Mediterraneo Hospital in Greece.

During the operation, surgeons use the HandX device to assist with the endoscopic dissection. Researchers will collect information about how long the surgery takes, whether the planned approach can be completed without switching to open surgery, and whether any surgical complications occur. They will also check healing, infection, and implant-related problems for up to 365 days after surgery. Participants will complete the BREAST-Q questionnaire before surgery and at several times after surgery to share their views on comfort, well-being, and cosmetic outcomes.

About 15 participants will take part. The results will help researchers understand whether this approach is practical and safe, and whether it should be studied further in a larger trial.

Study Overview

Status

Recruiting

Conditions

Intervention / Treatment

Detailed Description

This is a prospective, single-center, single-arm interventional study designed to evaluate the feasibility and surgical safety of HandX-assisted endoscopic nipple-sparing mastectomy with immediate implant-based breast reconstruction. The HandX system is a handheld articulating robotic instrument that provides wrist-like motion, motion scaling, and ergonomic control. Unlike console-based robotic platforms, HandX integrates into standard minimally invasive workflows without the need for a large footprint, dedicated console, or complex docking procedures. Early clinical experience in other surgical specialties suggests that the technology may improve access and ergonomics during dissection while maintaining procedural efficiency. This study investigates its use specifically in endoscopic breast surgery, where instrument articulation and visualization are key technical challenges.

All participants will undergo the mastectomy through a single lateral mammary fold incision. Following tumescent injection and creation of a working space, a single-port device is placed, and CO₂ insufflation is used to establish the operative cavity. The HandX device is then employed for endoscopic dissection of the breast gland from the skin envelope and the nipple-areola complex. Specimen retrieval is performed through the same incision. Reconstruction is completed using implant-based techniques (prepectoral, dual-plane, PU-coated, or subpectoral), according to preoperative planning and standard practice. Axillary procedures (sentinel lymph node biopsy or axillary lymph node dissection) may be performed through the same incision when indicated.

The study focuses on technical feasibility-specifically, the ability to complete the endoscopic mastectomy using the HandX platform without unplanned conversion to an open approach. Technical success is defined in the protocol and includes completion of all key steps of the planned minimally invasive procedure. Adjunct use of standard laparoscopic instruments or minor incision extensions for specimen handling does not constitute conversion, provided that the minimally invasive workflow is preserved.

Safety outcomes include intraoperative complications, 30-day and 90-day postoperative adverse events, surgical site infections assessed according to CDC/NHSN definitions, implant-related complications, and implant loss through one year. Postoperative care follows standardized pathways for implant-based reconstruction, including consistent antibiotic and VTE prophylaxis policies and predefined criteria for drain management. Participants are reviewed at scheduled visits through postoperative day 28, with additional follow-up through day 90 for infection surveillance, and through one year for implant-related outcomes.

Patient-reported outcomes are assessed using the BREAST-Q® Reconstruction Module (Version 2.0), administered preoperatively and at postoperative months 1, 6, and 12. These measures provide data on satisfaction with breasts, psychosocial and sexual well-being, physical well-being of the chest, and satisfaction with aspects of care. Only implant-reconstruction-relevant scales are used.

All data are collected in electronic case report forms, stored securely, and managed in compliance with GDPR and institutional policies. Monitoring is internal due to the single-center pilot nature of the study.

The study plans to accrue up to 20 mastectomy cases, corresponding to approximately 15 participants, as bilateral procedures are counted per breast. The sample size of 20 cases is consistent with recommendations for feasibility studies intended to inform future multicenter comparative trials. Analyses are descriptive. Technical success, complication rates, and patient-reported outcomes will be summarized with confidence intervals. Progression criteria and stopping rules are predefined in the protocol, including thresholds for major complications, device-related serious events, and oncologic or surgical concerns that may warrant pause or termination of the study.

Findings from this pilot study will inform the development of larger controlled trials evaluating the comparative effectiveness, aesthetic outcomes, recovery profiles, and cost implications of HandX-assisted endoscopic mastectomy relative to other surgical approaches.

Study Type

Interventional

Enrollment (Estimated)

15

Phase

  • Not Applicable

Contacts and Locations

This section provides the contact details for those conducting the study, and information on where this study is being conducted.

Study Contact

Study Locations

  • Greece
    • Attica
      • Glyfada, Attica, Greece, 16675
        • Recruiting
        • Mediterraneo Hospital
        • Contact:
        • Sub-Investigator:
          • Ioannis Papapanagiotou, MD, MSc, PhD
        • Sub-Investigator:
          • Apostolos Mitrousias, MD, MSc
        • Sub-Investigator:
          • Sandra Maria Tsoti, MD, MSc
        • Principal Investigator:
          • Vasileios Kalles, MD, MSc, PhD, FEBS

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

Eligibility Criteria

Ages Eligible for Study

  • Adult
  • Older Adult

Accepts Healthy Volunteers

No

Description

Inclusion Criteria:

  • Female sex
  • Age ≥ 18 years old

  • Indication for therapeutic or prophylactic (risk-reducing) mastectomy for:

    1. early invasive breast cancer (Clinical Stage I-II at diagnosis) undergoing primary surgery
    2. early invasive breast cancer (Clinical Stage I-II at diagnosis) undergoing surgery post systemic (neoadjuvant) therapy with clinical evidence of partial or complete response
    3. ductal carcinoma in situ (DCIS), or
    4. BRCA or other breast cancer - related genetic mutation carriers, or
    5. high risk for development of breast cancer.
  • Breast volume: cup sizes A to C as defined by underwear size, expected implant volume <550cc and glandular ptosis not exceeding Grade I Regnault's classification.
  • ECOG / WHO Performance Status <2
  • Subject with signed and dated informed consent form

Exclusion Criteria:

  • Chest wall or skin invasion
  • Extended lymph node involvement at diagnosis (cN2)
  • Inflammatory breast cancer
  • Tumor distance from nipple - areola complex <1cm on imaging studies
  • Active smoking/nicotine use within 4 weeks pre-op (combustible tobacco, vaping, nicotine pouches, NRT)
  • BMI >35
  • High risk patients with severe and poorly controlled co-morbid conditions (including but not limited to diabetes, heart disease, renal failure or liver dysfunction)
  • Pregnancy or breastfeeding
  • Psychiatric, addictive, or any disorders which compromise the ability to give informed consent for participation in this study
  • Subject without signed and dated informed consent form

Study Plan

This section provides details of the study plan, including how the study is designed and what the study is measuring.

How is the study designed?

Design Details

  • Primary Purpose: Treatment
  • Allocation: N/A
  • Interventional Model: Single Group Assignment
  • Masking: None (Open Label)

Arms and Interventions

Participant Group / Arm
Intervention / Treatment
Experimental: HandX-assisted endoscopic nipple sparing mastectomy
Patient cohort undergoing endoscopic nipple sparing mastectomy with use of HandX.
Procedure: Endoscopic nipple sparing mastectomy
A minimally invasive nipple-sparing mastectomy performed through a single lateral mammary fold incision using endoscopic visualization and CO₂ insufflation. Breast tissue is dissected from the skin envelope and nipple-areola complex, and immediate implant-based reconstruction is performed according to standard practice. The HandX device is used for articulating endoscopic dissection.
Device: HandX endoscopic instrument
A handheld articulating endoscopic instrument used to assist with endoscopic dissection during nipple-sparing mastectomy. The HandX device provides wrist-like articulation, motion scaling, and ergonomic control during minimally invasive surgery.

What is the study measuring?

Primary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Technical success
Time Frame: Intraoperative (Day 0)
Completion of the planned procedure via the minimally invasive approach without unplanned conversion.
Intraoperative (Day 0)
Surgical Safety
Time Frame: Postoperative Day 0-30
Major (Clavien-Dindo ≥III) complications
Postoperative Day 0-30

Secondary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Operative Time
Time Frame: Intraoperative (Day 0)
Total Operative Time
Intraoperative (Day 0)
Blood Loss
Time Frame: Intraoperative (Day 0)
Intraoperative Blood Loss
Intraoperative (Day 0)
Length of Stay
Time Frame: From hospitalization to discharge (average 1-3 days)
Length of hospital stay in days
From hospitalization to discharge (average 1-3 days)
Complications
Time Frame: Within 30 days after surgery
30-day complication rate (Clavien-Dindo)
Within 30 days after surgery
Skin flap necrosis
Time Frame: Within 30 days after surgery
The presence of skin flap necrosis will be noted during all the visits after the surgery (POD 7, 14, 28).
Within 30 days after surgery
Nipple Areola Complex ischemia
Time Frame: Within 30 days after surgery
Nipple-Areola-Complex (NAC) Ischemia noted during all the visits after the surgery (POD 7, 14, 28)
Within 30 days after surgery
Surgical Site Infection
Time Frame: Within 90 days after surgery
Number of participants with SSI (CDC/NHSN). Superficial incisional primary (SIP) within 30 days; deep incisional primary (DIP) and organ/space (O/S) within 90 days after the index BRST procedure.
Within 90 days after surgery
Implant loss
Time Frame: Within 1 year after surgery
Need to remove the implant for any reason
Within 1 year after surgery
Short - term Oncologic Adequacy
Time Frame: Within 40 days after surgery
Negative surgical margins on final pathology-retroareolar (nipple) margin negative and no tumor on ink on any sampled skin-flap or deep margin
Within 40 days after surgery
PROMs - Aesthetic Outcome
Time Frame: Preoperatively up to 4 weeks, 1 month postoperatively, 6 months postoperatively, 12 months postoperatively
BREAST-Q© questionnaire Version 2.0 measure the quality of life and satisfaction among patients undergoing breast surgery - Reconstruction module pre and postoperative, higher scores reflect a better outcome.
Preoperatively up to 4 weeks, 1 month postoperatively, 6 months postoperatively, 12 months postoperatively

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Sponsor

Vasileios Kalles

Investigators

  • Principal Investigator: Vasileios Kalles, MD, MSc, PhD, FEBS, Mediterraneo Hospital

Publications and helpful links

The person responsible for entering information about the study voluntarily provides these publications. These may be about anything related to the study.

General Publications

Study record dates

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

Study Major Dates

Study Start (Actual)

September 9, 2025

Primary Completion (Estimated)

October 1, 2028

Study Completion (Estimated)

October 1, 2029

Study Registration Dates

First Submitted

November 25, 2025

First Submitted That Met QC Criteria

December 5, 2025

First Posted (Actual)

December 18, 2025

Study Record Updates

Last Update Posted (Actual)

December 18, 2025

Last Update Submitted That Met QC Criteria

December 5, 2025

Last Verified

December 1, 2025

More Information

Terms related to this study

Keywords

Additional Relevant MeSH Terms

Other Study ID Numbers

  • 516

Plan for Individual participant data (IPD)

Plan to Share Individual Participant Data (IPD)?

NO

IPD Plan Description

"Individual participant data (IPD) will not be shared. This study is a small single-center feasibility trial, and the dataset contains clinical and surgical details that cannot be fully de-identified under GDPR. Summary results will be made available in the ClinicalTrials.gov record after study completion.

Drug and device information, study documents

Studies a U.S. FDA-regulated drug product

No

Studies a U.S. FDA-regulated device product

No

product manufactured in and exported from the U.S.

No

This information was retrieved directly from the website clinicaltrials.gov without any changes. If you have any requests to change, remove or update your study details, please contact register@clinicaltrials.gov. As soon as a change is implemented on clinicaltrials.gov, this will be updated automatically on our website as well.

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