Breast Neoplasms, Breast Reconstruction, Postoperative Complications
Conditions
Keywords
DIEP flap, Breast reconstruction, Computed tomography angiography, Vascular anatomy, Unplanned takeback
Brief summary
This multicenter retrospective observational study will develop and validate a CTA-based quantitative risk score-the DIEP Morphological Deviation Score (DIEP-MDS)-to estimate the risk of flap-related vascular compromise and flap failure in patients undergoing DIEP flap breast reconstruction. The score will quantify the extent to which an individual's perforator anatomy deviates from normative anatomic distributions derived from a reference population of individuals without breast cancer or reconstructive surgery. Specifically, a cohort of randomly selected individuals with available CTA imaging will be used to establish population-level reference distributions for key anatomic features relevant to DIEP perforator morphology, including length, diameter, and muscle thickness. The study will determine whether greater deviation in DIEP morphology, as quantified by the DIEP-MDS, is associated with an increased risk of flap-related vascular compromise and flap failure. The score will be evaluated in an internal surgical cohort and externally validated in an independent multicenter surgical cohort. In addition, the study will pre-specify an analysis to assess whether a dual-pedicle strategy is associated with a lower risk of flap-related vascular compromise compared with a single-pedicle strategy across DIEP-MDS risk strata.
Detailed description
Deep inferior epigastric artery perforator (DIEP) flap breast reconstruction is a cornerstone technique in autologous breast reconstruction after mastectomy. By preserving the rectus abdominis muscle while providing durable soft-tissue replacement, the DIEP flap provides reliable reconstructive volume and favorable aesthetic outcomes. Despite these advantages, the success of DIEP flap breast reconstruction depends critically on achieving and maintaining adequate flap perfusion. Early postoperative flap-related vascular compromise-including venous congestion, arterial insufficiency, pedicle thrombosis, and pedicle kinking or torsion-may require unplanned surgical takeback and can result in flap failure. These events increase perioperative morbidity, expose patients to additional procedures, prolong hospitalization, and increase health care resource utilization. Preoperative identification of patients at increased risk of flap-related vascular compromise is therefore clinically important for surgical planning, patient counseling, and risk mitigation. The vascular reliability of DIEP flap is closely related to DIEP perforator morphology, including perforator length, diameter, muscle thickness, and other anatomic features relevant to flap perfusion. Computed tomographic angiography (CTA) has become an integral component of preoperative planning for DIEP flap breast reconstruction and is widely used to map perforator anatomy and guide perforator selection. However, CTA-based assessment remains largely descriptive, with emphasis on anatomic mapping and selection of dominant perforators. Few studies have translated CTA-derived DIEP perforator morphology into a standardized quantitative framework for risk stratification of flap-related vascular compromise and flap failure. We hypothesized that marked deviation of an individual's perforator anatomy from normative anatomic distributions may increase the technical complexity and unpredictability of flap harvest, intramuscular perforator dissection, and pedicle preparation. This deviation in DIEP morphology may predispose to intraoperative vascular traction, vessel injury, vasospasm, or suboptimal pedicle preparation, thereby potentially increasing the risk of early postoperative flap-related vascular compromise, subsequent unplanned surgical takeback, and flap failure. In this multicenter retrospective observational study, we will develop a CTA-based quantitative risk score, termed the DIEP Morphological Deviation Score (DIEP-MDS). Using a reference CTA cohort of individuals without breast cancer or reconstructive surgery, we will first establish reference distributions for key anatomic features relevant to DIEP perforator morphology, including length, diameter, and muscle thickness. We will then convert CTA-derived anatomic features into a standardized deviation score that quantifies the extent to which a patient's perforator anatomy differs from these reference distributions. In the internal surgical cohort, the study will assess whether higher DIEP-MDS values are associated with increased risks of flap-related vascular compromise requiring unplanned surgical takeback, as well as flap failure. The score will subsequently be externally validated in an independent multicenter surgical cohort. The study will pre-specify an analysis to assess whether a dual-pedicle strategy is associated with a lower risk of flap-related vascular compromise compared with a single-pedicle strategy across DIEP-MDS risk strata.
Interventions
None listed
Sponsors
Zhuliling
Study design
Observational model
COHORT
Time perspective
RETROSPECTIVE
Eligibility
Sex/Gender
FEMALE
Age
18 Years to 80 Years
Healthy volunteers
No
Inclusion criteria
1. Female participants aged 18 to 80 years. 2. Reference CTA cohort: adult women without breast cancer or reconstructive surgery who had available abdominal CTA imaging of sufficient quality, obtained for reasons unrelated to breast reconstruction. 3. Internal surgical cohort: patients who underwent DIEP flap breast reconstruction at the coordinating center, with available preoperative abdominal CTA imaging and traceable perioperative and outcome data. 4. External multicenter surgical cohort: patients who underwent DIEP flap breast reconstruction at participating external centers, with available preoperative abdominal CTA imaging and traceable perioperative and outcome data. 5. For the internal and external surgical cohorts, operative records must clearly document whether a single-pedicle strategy or dual-pedicle strategy was used.
Exclusion criteria
1. Prior abdominal flap harvest, abdominoplasty, major lower abdominal wall reconstruction, or extensive abdominal wall trauma or scarring expected to substantially alter DIEP perforator morphology. 2. Poor CTA image quality or insufficient image coverage for standardized assessment of key anatomic features relevant to DIEP perforator morphology. 3. Missing key clinical, imaging, operative, or outcome data required for the study analysis. 4. Non-DIEP abdominal flap procedures, combined flap procedures, or procedures in which DIEP flap anatomy, pedicle strategy, flap-related vascular compromise status, unplanned surgical takeback status, or flap failure status cannot be clearly determined. 5. For the reference CTA cohort, any history of breast reconstruction or abdominal wall procedures expected to substantially alter DIEP perforator morphology.
Design outcomes
Primary
| Measure | Time frame | Description |
|---|---|---|
| Number of Participants With Total DIEP Flap Failure Within 30 Days | Within 30 days after completion of the index DIEP flap surgery. | Total DIEP flap failure will be assessed as a binary outcome (yes/no) through review of postoperative clinical assessments and reoperation records. Total flap failure is defined as complete and irreversible loss of viability of the reconstructed DIEP flap resulting in complete flap removal. The outcome will be reported as the number and percentage of participants who experience total flap failure. |
Secondary
| Measure | Time frame | Description |
|---|---|---|
| Unplanned Surgical Takeback for Flap-Related Vascular Compromise Within 48 Hours | Within 48 hours after completion of the index DIEP flap surgery. | Return to the operating room within 48 hours after completion of the index DIEP flap surgery for exploration or intervention prompted by suspected or confirmed flap-related vascular compromise. |
| Composite Early Flap-Related Vascular Compromise or Flap Failure Within 30 Days | Within 30 days after completion of the index DIEP flap surgery. | Number and proportion of surgical cohort participants who experience either unplanned surgical takeback for suspected or confirmed flap-related vascular compromise within 48 hours after completion of the index DIEP flap surgery or total flap failure within 30 days after completion of the index DIEP flap surgery. |
Countries
China
Contacts
STUDY_CHAIRLiling Zhu
Sun Yat-Sen Memorial Hospital of Sun Yat-Sen University
Outcome results
None listed