Key messages

• Autologous breast reconstruction compared to prosthetic breast reconstruction could reduce reoperations for general complications in patients that will undergo in patients that will undergo post-reconstruction radiotherapy (low certainty evidence).
• Autologous breast reconstruction compared to prosthetic breast reconstruction probably increases skin or flap necrosis in patients that will undergo post-reconstruction radiotherapy. 
• We are uncertain whether autologous breast reconstruction compared to prosthetic breast reconstruction reduces breast reconstruction failure, surgical site infection, wound dehiscence or presence of hematoma or seroma, as the certainty of evidence has been assessed as very low.

What is the evidence.
See evidence matrix  in Epistemonikos later

We found five systematic reviews [6],[7],[8],[9],[10] that included nine primary studies overall [11],[12],[13],[14],[15],[16],[17],[18],[19], of which all corresponded to observational studies.

Three non-comparative studies were excluded from this summary [12],[16],[18]. 

This table and general summary are based in six observational studies [11],[13],[14],[15],[17],[19] as no randomized trials were found that answered the question of interest.

What types of patients were included*

The effect of radiotherapy on breast reconstruction was evaluated for both groups. Six studies evaluated patients with post reconstructive radiotherapy [11],[13],[14],[15],[17],[19] and two of these studies also included patients with pre reconstruction radiotherapy [11],[15], whose subgroup was not considered for the analysis.

No study described the average dose of radiotherapy used in patients.

Two studies reported confusing potential variables such as body mass index, smoking habit or diabetes [11],[15], while four did not report it.

What types of interventions were included*

In relation to breast reconstruction, three studies included patients with primary breast reconstruction [11],[15],[19] and three studies did not specify it [13],[14],[17].

In relation to type of reconstruction, six studies compared tissue expander/implant against autologous tissue. Of the latter, one study included autologous reconstruction with pedicled transverse rectus abdominis myocutaneous (TRAM) flap [15], two studies included TRAM flap not specified [11],[19] and three studies did not reported the type of autologous reconstruction [13],[14],[17].

What types of outcomes 
were measured

The studies measured multiple outcomes that were organized by the systematic reviews as follows:

• Reconstruction failure
• Surgical site infection
• Wound dehiscence
• Skin or flap necrosis
• Hematoma or seroma
• Reoperation for general complications

The average follow-up of the studies was 30 months with a range between 1 and 153 months.

Follow the link to access the interactive version of this table (Interactive Summary of Findings - iSoF)

To whom this evidence does and does not apply

• The evidence presented applies to patients that will undergo post reconstructive radiotherapy, whether with autologous reconstruction with pedicled or free transverse rectus abdominis myocutaneous (TRAM) flap or prosthetic reconstruction.
• Although the studies did not evaluate patients with other types of flaps such as the latissimus dorsi myocutaneous flap or deep inferior epigastric artery perforator flap, in the absence of direct evidence, it is reasonable to extrapolate the evidence to these cases.
• The evidence presented is not aimed to patients undergoing radiotherapy prior to breast reconstruction, so it is not reasonable to extrapolate the results to this population.

• There are no standardized outcomes to report breast reconstruction results [20]. The outcomes selected in the table are those considered critical for decision-making according to the opinion of the authors of this summary, which coincide in general with those presented in the systematic reviews identified.
• The outcome breast reconstruction failure is defined in the case of prosthetic reconstruction as prosthetic extrusion or implant rupture [15]. In autologous reconstruction it was defined as flap failure without specifying its cause [15].
• The outcome skin or flap necrosis is also stated as skin or ‘fat’ necrosis in one systematic review, making interpretation difficult. It is not clear if it is considering partial, total necrosis or both. On the other hand, of the included primary studies, no events were found in the comparison group for this outcome, which led us to extrapolate the proportion of skin or flap necrosis events without radiotherapy for this group.
• The outcomes capsular contracture and fibrosis were not analyzed because they occur separately, either in prosthetic reconstruction or autologous reconstruction respectively.

• It is difficult to determine the balance between benefits and risks between autologous and prosthetic breast reconstruction in patients who will undergo post reconstructive radiotherapy because, for most outcomes, the certainty of evidence was very low.
• While autologous reconstruction seems to have fewer complications overall than prosthetic reconstruction, it probably increases the risk of skin or flap necrosis.

• None of the systematic reviews considered an economic analysis for each intervention. In addition, considering the poor level of certainty of the evidence, it is not appropriate to analyze this aspect until the benefits of one technique are proven over the other.

• Although the decision is discussed and individualized for each patient, prosthetic reconstruction is currently performed more frequently due to reduced surgical times, hospitalization length and recovery time. However, it usually requires a second operation and several tissue expansions.
• It is unlikely that the evidence presented would modify clinical decisions, since their level of certainty is very poor. However, based on individual values and preferences, especially those related with skin or flap necrosis, some patients or clinicians might prefer one intervention over the other.

Differences between this summary and other sources

• Four of the systematic reviews concluded in favor of autologous breast reconstruction [5],[7],[8],[10], while only one coincides with the results presented here [9]. However, systematic reviews that favor autologous breast reconstruction recognize the limitation of the primary studies and the lack of standardization in the report of outcomes used to obtain their conclusions.
• There are no international clinical guidelines that address the type of breast reconstruction. However, an up-to-date review article recommends autologous reconstruction over prosthetic reconstruction [21].

• The likelihood of future research changing the conclusions of this summary is high, due to the limitations of existing evidence.
• We did not identify systematic reviews or ongoing trials evaluating this question in PROSPERO or in the International Clinical Trials Registry Platform of the World Health Organization.