A Comparative Study of Delayed Endoscopic DTI and Autologous Flap Reconstruction Post-Mastectomy (DEDIA)

A National Multicenter, Prospective, Cohort Study on Delayed Endoscopic Direct-to-Implant Breast Reconstruction Via Transaxillary Approach Versus Autologous Flap Breast Reconstruction Following Mastectomy

In China, low breast-conserving surgery rates and historically minimal immediate reconstruction following mastectomy have resulted in a significant population of women living without a breast, often leading to long-term psychosocial distress. Current delayed reconstruction options are limited: traditional two-stage implant reconstruction necessitates two surgeries with associated costs and risks like infection and implant exposure, while autologous tissue transfer (e.g., TRAM/DIEP flaps), though offering superior natural aesthetics and patient satisfaction, involves extensive donor-site morbidity, prolonged recovery, and significant scarring, restricting its suitability. To address the drawbacks of both established methods-significant trauma, cost, and complexity-this study evaluates a novel technique for breast cancer patients post-mastectomy: endoscopic delayed direct-to-implant breast reconstruction. This study proposes to conduct a prospective cohort study to analyze complication rates, breast aesthetic scores, quality of life metrics, and other dimensions between delayed direct-to-implant breast reconstruction and abdominal flap breast reconstruction（DIEP and TRAM). The aim is to comprehensively evaluate the safety and clinical feasibility of endoscopic delayed direct-to-implant breast reconstruction.

Study Overview

• Status: Not yet recruiting
• Conditions: Breast Reconstruction After Mastectomy

Detailed Description

This study is a multicenter, Prospective, randomized controlled trial. According to previous study results, the mean difference in Breast-Q breast satisfaction scores at one year postoperatively versus preoperatively was approximately 10.4 points in the autologous tissue breast reconstruction group. It is estimated that the two-stage prosthetic breast reconstruction group will achieve a 10.4-point improvement in breast satisfaction scores one year after surgery. The difference in Breast-Q breast satisfaction scores between postoperative and preoperative assessments is non-inferior to that of autologous reconstruction. Based on historical data, the sample size was calculated for both groups, with the study hypothesis that the difference in Breast-Q breast satisfaction scores between postoperative and preoperative assessments in the two-stage prosthetic reconstruction group is non-inferior to that of the two-stage abdominal flap breast reconstruction group (non-inferiority margin = 2). Stratification was performed based on whether radiotherapy was administered, dividing into a postoperative radiotherapy group and a non-radiotherapy group, with a sample size ratio of radiotherapy group to non-radiotherapy group = 1:2. Within each stratified group, the ratio of two-stage prosthetic reconstruction to abdominal flap reconstruction was set at 3:1. Using a one-sided test with a significance level of α = 0.05 and 80% statistical power, and assuming a 10% dropout rate, the total sample size required is 588. This includes 196 cases in the radiotherapy group (147 cases in the two-stage prosthetic reconstruction group and 49 cases in the abdominal flap reconstruction group) and 392 cases in the non-radiotherapy group (294 cases in the two-stage prosthetic reconstruction group and 98 cases in the abdominal flap reconstruction group).

1. Postoperative Surgical Complications: Assessed using Any Complication, Major Complication, and Minor Complication.

1. Any Complication: Any complication related to the surgical procedure occurring postoperatively. Each occurrence in a subject counts as one event. Postoperative complications can be classified into Grades I-V according to the Clavien-Dindo classification system. Complications graded Clavien-Dindo III or higher are considered Major Complications.
2. Major Complication: Defined as a complication related to the reconstructive procedure that persists despite observation and conservative management, requiring surgical intervention. Examples include wound dehiscence, hemorrhage requiring surgical intervention, surgical site infection, flap ischemia/necrosis, implant rupture, prosthesis loss, etc.
3. Minor Complication: Defined as a complication that resolves with observation or conservative management alone, without requiring surgical intervention. Examples include hemorrhage controllable by compression, surgical site infection controllable by oral antibiotics, seroma after drain removal, arm lymphedema, localized skin flap or NAC (nipple-areolar complex) ischemia/necrosis resolving spontaneously, implant malposition correctable by manual manipulation, animation deformity due to pectoralis major muscle division, pectoralis major muscle spasm, etc.

2. Postoperative Aesthetic Outcomes and Quality of Life (QoL) Assessment: Evaluated using the following validated instruments: the BREAST-Q questionnaire (Reconstruction module), Ueda Scale, Harris Scale, QLQ-BR45 questionnaire, and SCAR-Q questionnaire.

3. Aesthetic Complication Assessment: Evaluated through assessment of capsular contracture, implant visibility/palpability (contour visibility), rippling, implant malposition/displacement, and the need for secondary surgery due to aesthetic concerns.

1. Capsular Contracture (Baker Classification): A complication where the fibrous capsule surrounding the implant abnormally thickens, hardens, and contracts, leading to breast firmness, distortion, and/or pain.
2. Rippling: The appearance of visible wrinkles or folds on the skin surface overlying the implant.
3. Implant Visibility/Palpability (Contour Visibility): A phenomenon where the edge or shape of the implant becomes visibly apparent or readily palpable beneath the skin surface. Can be graded as mild, moderate, or severe.
4. Implant Malposition/Displacement: Shifting of the implant from its intended position post-implantation, resulting in abnormal breast contour or asymmetry.
5. Animation Deformity: Characterized by abnormal movement, contour distortion, or functional limitation of the breast mound during pectoralis muscle contraction (e.g., during arm movement).
6. Pectoralis Major Muscle Pain: Pain localized to the region of the pectoralis major muscle.

• Study Type: Observational
• Enrollment (Estimated): 588

Contacts and Locations

• Study Contact: Name: Zhenggui Du; Phone Number: +86 13880768222; Email: docduzg@163.com

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Adult; Older Adult
• Accepts Healthy Volunteers: No

• Sampling Method: Non-Probability Sample

Study Population

This technique, developed as an original procedure by our team, is performed through an axillary incision using a gas-inflated endoscopic approach. It breakthroughly integrates the traditional two-stage operation into a single-stage procedure.First, the retropectoral plane is dissected using a reverse-sequence technique. Postoperatively, intentional fluid accumulation within the implant pocket is utilized to expand the skin envelope. This achieves significantly greater tissue expansion compared to conventional tissue expanders, resulting in a reconstructed breast with a more natural contour and softer tissue consistency.Second, the entire procedure strategically avoids creating any new incisions within the breast region itself. This significantly reduces the risks of wound dehiscence and surgical site infection, while simultaneously shortening the postoperative recovery period.

Description

Inclusion Criteria:

• Female patients aged 18-70 years
• One year after simple mastectomy or six months after completion of radiation therapy with healthy local skin activity and skin laxity;
• voluntary participation and ability to provide written informed consent.

Exclusion Criteria:

• History of breast surgery in which the pectoralis major muscle was removed;
• History of abdominal surgery (both lumpectomy and open surgery)
• patients with a history of Kocher incision or complete subcostal incision;
• Patients with scarring in the midline of the lower abdomen;
• body mass index (BMI) < 30 kg/m²;
• Patients with serious preoperative co-morbidities and poor general condition who cannot tolerate the surgery;
• Diabetes mellitus with a long history of smoking or combined poor glycemic control;
• current enrollment in other clinical trials that may interfere with study outcomes;
• Review (clinical, imaging, pathological basis) reveals the presence of local/regional recurrence or uncontrollable distant metastasis.

Study Plan

How is the study designed?

Number of groups / cohorts

2

Cohorts and Interventions

Group / Cohort
delayed Endoscopic DTI Breast Reconstruction; This technique, developed as an original procedure by our team, is performed through an axillary incision using a gas-inflated endoscopic approach. It breakthroughly integrates the traditional two-stage operation into a single-stage procedure.First, the retropectoral plane is dissected using a reverse-sequence technique. Postoperatively, intentional fluid accumulation within the implant pocket is utilized to expand the skin envelope. This achieves significantly greater tissue expansion compared to conventional tissue expanders, resulting in a reconstructed breast with a more natural contour and softer tissue consistency.Second, the entire procedure strategically avoids creating any new incisions within the breast region itself. This significantly reduces the risks of wound dehiscence and surgical site infection, while simultaneously shortening the postoperative recovery period.
delayed Autologous Flap Breast Reconstruction; ·DIEP Flap (Deep Inferior Epigastric Perforator Flap) The DIEP flap uses skin and fat from the lower abdomen but preserves the rectus abdominis muscle. Only the tiny perforating blood vessels (deep inferior epigastric artery and vein) that pass through the muscle are dissected and taken with the flap. These vessels are then reconnected to vessels in the chest (usually internal mammary vessels) under a microscope. Advantages: Minimal abdominal wall morbidity; lower risk of bulge or hernia; faster recovery of core strength. ·TRAM Flap (Transverse Rectus Abdominis Myocutaneous Flap) The TRAM flap also uses lower abdominal tissue, but it includes a segment of the rectus abdominis muscle (either pedicled or free). In the pedicled version, the muscle with its overlying skin/fat is tunnelled under the skin up to the chest, relying on the superior epigastric vessels. In the free TRAM, the muscle is detached and reattached to chest vessels like a DIEP.

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
breast satisfaction	Compare the BREAST-Q score（The psychosocial well-being, satisfaction with breasts, satisfaction with sexual life, and physical well-being of the chest from the BREAST-Q questionnaire's breast reconstruction module were used for evaluation. The BREAST-Q scoring system converts each patient's performance across these domains into independent scores ranging from 0 to 100, with higher scores indicating better health-related quality of life or satisfaction in the corresponding domain.）	1 year

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Operative time	duration from skin incision to completion of wound closure	during operation
surgical-related costs	includes all direct medical expenses incurred during the operation	during operation
Complication outcomes	Surgical complication rates, including flap scald, NAC ischemia/necrosis, seroma, surgical area infection, bleeding, incision splitting, flap ischemia/necrosis	3 months and 1 year postoperatively between the two groups.
Doctor-report outcomes	-The Ueda scale is independently assessed by three professional healthcare workers across multiple domains, including breast size symmetry, breast shape symmetry, scar visibility, nipple-areola complex (size symmetry, position symmetry, color consistency), and inframammary fold position symmetry. Individual items are scored from 0 to 2 points, with a total score ranging from 0 to 10. Higher scores indicate better postoperative aesthetic outcomes: a total score of ≥9 is considered excellent, 7-8 good, 5-6 fair, and ≤4 poor.	Intraoperative, 3 months, 1 year postoperatively
patient-report outcomes（Harris scale）	It consists of four grades: Excellent (bilateral breasts essentially symmetric both with and without a bra), Good (symmetric when wearing a bra but obviously asymmetric without a bra), Fair (asymmetric but not obvious even when wearing a bra), and Poor (one breast destroyed or bilateral breasts obviously asymmetric). Higher scores indicate better aesthetic outcomes.	Intraoperative, 3 months, 1 year postoperatively
patient-report outcomes （SCAR-Q scale）	a patient-reported questionnaire consisting of 12 items, scoring only the scar on the operated side. Higher scores indicate better aesthetic outcomes.	Intraoperative, 3 months, 1 year postoperatively
patient-report outcomes (The QLQ-BR45 scale )	assesses quality of life in breast cancer patients, including both core cancer and breast cancer-specific dimensions. It covers 4 functional domains, 9 symptom domains, and 6 single items/symptoms. The scale uses a 4-point Likert response (1="Not at All" to 4="Very Much"). Domain scores are linearly converted to a 0-100 scale; higher scores indicate better quality of life for functional domaTime Frame: Intraoper	Intraoperative, 3 months, 1 year postoperatively
Aesthetic complications	Capsular contracture (Baker Grade); Implant visibility/palpability (contour visibility); Rippling; Implant malposition/displacement; Animation deformity; Pectoralis major muscle pain;	1 years postoperatively

Collaborators and Investigators

• Sponsor: West China Hospital

Study record dates

Study Major Dates

• Study Start (Estimated): September 1, 2026
• Primary Completion (Estimated): December 31, 2028
• Study Completion (Estimated): December 31, 2030

Study Registration Dates

• First Submitted: April 17, 2026
• First Submitted That Met QC Criteria: May 21, 2026
• First Posted (Actual): May 22, 2026

Study Record Updates

• Last Update Posted (Actual): May 22, 2026
• Last Update Submitted That Met QC Criteria: May 21, 2026
• Last Verified: April 1, 2026

More Information

Terms related to this study

• Keywords: DIEP; delayed Endoscopic DTI; TRAM
• Other Study ID Numbers: 2025(1491)

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: UNDECIDED

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No