Use of Diced Cartilage for Management of Internal Mammary Vessel Exposure Sites in Autologous Breast Reconstruction
Conditions: Mammaplasty, Microsurgery, Rip Reconstruction Cartilage
Sponsor: ISAR Klinikum

 
 
 
 
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Project title: 
Use of Diced Cartilage for Management of Internal Mammary Vessel Exposure Sites in 
Autologous Breast Reconstruction 
 
Date: 10.07.2024 
 
 

 
 
 
 
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1) Studyprotocol 
Procedures for informing and obtaining consent: 
The recruited subjects will be informed about the nature, importance, risks (anonymizes data 
management) and scope of the intended scientific investigation in a personal conversation with 
one of the investigators and will receive patient information. After sufficient time for reflection, 
the consent will be confirmed in writing on the form prepared for this purpose - declaration of 
consent. 
Measures: 
This retrospective single-center cohort study included all autologous breast reconstructions 
performed from October 2021 to June 2023, in which diced cartilage (DC) was used to manage 
internal mammary vessel exposure sites (IMVES). These reconstructions will be divided into 
two groups: one with prior ipsilateral breast radiotherapy (DCR) and one without irradiation 
(DC) to evaluate the suitability of irradiated cartilage for the DC procedure. The control group 
consisted of an equal number of consecutive autologous breast reconstructions performed 
before the implementation of the DC procedure, for which rib cartilage segments were also 
removed but IMVES were managed conservatively. Controls will not be recruited during the 
period of DC use because initially, DC was not used consistently by all team members and 
may have been avoided in difficult reconstructions limiting the comparability of these patients. 
Data will be collected using electronic patient records, photographic documentation, and 
available postoperative MRI of reconstructed breasts. 
Magnetic resonance imaging (MRI) scans performed at least 6 months postoperatively will be 
used to evaluate the sinking depth of epicostal soft tissue into the space of rib segment 
resection on axial planes (JiveX Software, VISUS Health IT GmbH, Bochum, Germany). 

 
 
 
 
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Postoperative photographic images will be examined by two investigators (blinded to group 
assignments) for IMVES-associated deformities using standardized photographic images of 
the reconstructed breasts at the 6-month follow-up. 
 
2) Statistical Analysis Plan 
Statistical analysis will be performed using IBM SPSS Version 24 (IBM, Somers, NY, USA) 
and R 4.3.2 (R Core Team). Metrically scaled parameters will be assessed for a normal 
distribution using Shapiro–Wilk tests. Results for normal data will be presented as mean ± 
standard deviation (SD) and will be analyzed using multi-factor variance analysis. Paired t-
tests with Bonferroni correction will be used when significant differences were observed. Non-
normally distributed metric parameters will be expressed as median (Q25–Q75) values and 
will be assessed using the Kruskal–Wallis test. Pairwise Mann–Whitney U tests with the 
Bonferroni correction will be used when significant differences were found. Categorical 
parameters will be assessed using the Chi-squared or Fisher tests, without tests for normality. 
Pairwise chi-square tests (or Fisher tests) with Bonferroni correction will be used when 
significant results were found. MRI data will be analyzed by isolating subgroups of the study 
population with MRI and applying pairwise case exclusions. A Chi-square test of independence 
will be performed to determine whether the groups differed significantly with regard to the 
presence of MRI. In addition, further comparison of the three groups will be carried out for the 
variables surveyed to clarify group differences. The significance level will be set at α = 0.05 for 
all tests.