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Correspondence to: Department of Plastic, Reconstructive, and Aesthetic Surgery, Geneva University Hospitals, Rue Gabrielle-Perret-Gentil 5, 1205 Geneva, Switzerland.
The inferior gluteal artery perforator (IGAP) flap is an alternative technique for autologous breast reconstruction. In contrast to other commonly used techniques, there is a paucity of literature on the safety and efficacy of the IGAP flap. The aim of this study was to perform a systematic literature review and meta-analysis of postoperative outcomes and complications associated with the IGAP in autologous breast reconstructions to validate its safety.
Methods
A systematic review of literature was performed following PRISMA guidelines. Articles reporting post-operative outcomes of IGAP flaps in autologous breast reconstruction were included. A proportional meta-analysis of post-operative complications was performed to obtain their proportions with 95% confidence intervals (CIs).
Results
Seven studies met the inclusion criteria, representing a total of 239 IGAP flaps in 181 patients The total flap loss rate was 3% (95% CI 0–8%), partial flap loss rate was 2% (95% CI 0–4%), hematoma rate was 3% (95% CI 0–7%), overall donor-site complication rate was 15% (95% CI 5–28%), overall recipient-site complication rate was 24% (95% CI 15–34%), and the overall complication rate was 40% (95% CI 23–58%).
Conclusions
This meta-analysis provides comprehensive knowledge on the safety and efficacy of the IGAP flap in autologous breast reconstruction. It evidences its overall safety and validates its role as an effective option in breast reconstruction.
According to the American Cancer Society, an estimated 287,000 new cases of invasive breast cancer in women will be diagnosed in the United States' states alone in 2022, giving women a lifetime risk of 1 in 8 of having the disease.
Despite being the second leading cause of death for women in the U.S. with more than 43,000 deaths in 2022, breast cancer mortality in women has been consistently declining since the 1980s.
Breast cancer diagnosis and its treatment can lead to debilitating symptoms such as chronic pain, fatigue, anxiety, insomnia, impaired body image, and decreased sexual functioning and satisfaction, which results in a significant decrease in self-esteem and quality of life.
Breast reconstruction has been found to improve patients' aesthetic satisfaction and quality of life following mastectomy and can be performed immediately or in a delayed fashion.
Quality-of-life outcomes between mastectomy alone and breast reconstruction: comparison of patient-reported BREAST-Q and other health-related quality-of-life measures.
Both implant-based and autologous reconstruction techniques can be used in either situation. While technically more challenging and more time-consuming compared to implant-based reconstructions, autologous tissue reconstruction has a several advantages, including longer-lasting postoperative results, a more natural breast shape, higher patient satisfaction in the long term, and no need for replacement over time.
Furthermore, in cases where the patient has received radiation therapy, autologous breast reconstruction significantly reduces the risk of reconstructive failure and complications.
Should Immediate Autologous Breast Reconstruction Be Considered in Women Who Require Postmastectomy Radiation Therapy? A Prospective Analysis of Outcomes.
There are numerous procedures available for autologous breast reconstruction nowadays, but the deep inferior epigastric perforator (DIEP) flap remains the gold standard flap for most plastic surgeons.
Quality of Life and Patient-Reported Outcomes in Breast Cancer Survivors: A Multicenter Comparison of Four Abdominally Based Autologous Reconstruction Methods.
Complications and Patient-Reported Outcomes after Abdominally Based Breast Reconstruction: Results of the Mastectomy Reconstruction Outcomes Consortium Study.
However, the DIEP flap is not appropriate for every patient requiring breast reconstruction, typically due to limited abdominal tissue, past abdominal surgical procedures, donor site scar acceptance, or patient desire.
If abdominal flaps are not suitable, other reconstructive options include thigh-based flaps such as the profunda artery perforator (PAP) and the transverse myocutaneus gracilis (TMG), and buttock-based flaps such as the inferior gluteal artery perforator (IGAP) or superior gluteal artery perforator (SGAP).
Allen and Tucker described the superior gluteal artery perforator (SGAP) flap for breast reconstruction in 1995.
In the years that followed, Higgins et al. in 2002 and Guerra et al. in 2004 both used the inferior gluteal artery perforator (IGAP) flap for the repair of ischial pressure sores and consecutively for breast reconstruction.
The current literature on the use of the IGAP is extensive, however information on outcomes is limited. The purpose of this study was to conduct a systematic review and meta-analysis of the literature on the IGAP flap and its outcomes in terms of safety and reliability of postoperative outcomes in breast reconstruction.
Method
PRISMA guidelines for reporting study results were followed. Our systematic review and meta-analysis study protocol was prospectively registered on PROSPERO (registration ID: CRD42022376927).
Search strategy
The review question was defined using the PICO principles: Evaluate the safety and efficacy of the IGAP flap in autologous breast reconstruction in term of postoperative outcomes. To answer this question, a systematic review of Pubmed, Embase/MEDLINE/Preprint, Web of Science and Cochrane library was conducted on November 18, 2022. A combination of Mesh terms and keywords synonyms of “breast reconstruction”, “Inferior Gluteal Artery Perforator”, linked with Booleans operators were used to develop a search strategy (Table 1).
Table 1Search strategy.
Database
Date
Search query
N articles
Pubmed
18th Nov
(("Mammaplasty"[Mesh]) OR (Breast reconstruction)) AND ((IGAP) OR (Gluteal perforator) OR (Inferior Gluteal perforator) OR (gluteal flap))
207
Embase, MEDLINE, Preprints
18th Nov
('breast reconstruction'/exp OR 'breast reconstruction') AND ('inferior gluteal artery perforator flap' OR 'gluteal flap' OR 'gluteal perforator')
74
Web of Science
18th Nov
((ALL=(breast reconstruction)) OR ALL=(mammaplasty)) AND ((((ALL=(Igap)) OR ALL=(inferior gluteal artery perforator)) OR ALL=(gluteal flap)) OR ALL=(gluteal perforator))
245
Cochrane library
18th Nov
ID search hits #1MeSH descriptor: [Mammaplasty] explode all trees #2(breast reconstruction):ti,ab,kw #3(IGAP):ti,ab,kw OR ("inferior gluteal artery perforator"):ti,ab,kw OR (Gluteal flap):ti,ab,kw OR (inferior gluteal perforator):ti,ab,kw #4(#1 OR #2) AND #3
Inclusion and exclusion criteria were defined using the PICOS principles before starting the review process. (Table 2) We sought to include studies of patients who benefited from breast reconstruction and excluded animal and cadaveric studies. To be considered for inclusion, the flap had to be an inferior gluteal artery perforator flap. Studies on bilateral flap reconstruction procedures were included. All other gluteal flaps, that were not inferior gluteal artery perforator based, such as the superior gluteal artery perforator (SGAP) flap or the fasciocutaneous infragluteal (FCI) free flap were excluded. The main outcome had to be reported in all selected articles. As we aimed at assessing safety and efficacy of the procedure, total flap failure rate was selected as the primary study outcome. Definition was complete flap loss, or reconstructive failure. Studies reporting surgical outcomes in a prospective and retrospective fashion were included. While we decided to include cases series, case reports were excluded. Systematic reviews, meta-analysis, reviews, letters and congress abstracts were also excluded. No language or publication restriction date were applied.
Table 2Selection criterion.
PICOS
Inclusion
Exclusion
Population
Adult with breast reconstruction
Cadaver, Animal
Intervention
IGAP
Other flaps
Comparator
Not applicable
Outcomes
Primary: Total flap loss rate. Secondary: Post-operative complications
If primary outcome not reported
Studies
Prospective, Retrospective, Comparative, case series.
Reviews, meta-analysis, letters, abstract only, case report.
Articles retrieved from the search query were processed through Rayyan (https://www.rayyan.ai/; accessed on 21 November 2022) to allow independent, blind screening by two authors (J.M.;M.S.).
Articles were first screened by title and abstract, and in case of a divergent opinion, it was solved after consultation with the senior author (C.M.O.). Selected articles were then fully read by the two authors and if they matched selection criteria, they were incorporated in a standardized spreadsheet file.
Data extraction and outcomes definition
Data on studies characteristics and clinical outcomes were then independently collected and included in an Excel file (version 16.30, Microsoft Corp., Redmond, WA, USA) by the two authors (J.M.;M.S.) and results were compared to detect potential reporting errors. Demographic variables, main outcome and secondary outcomes were recorded – the main outcome being total flap failure rate, and secondary outcomes being post-operative complications reported in the articles. To be considered for inclusion in the meta-analysis a complication had to be reported in three or more articles, otherwise they would only be described in the results section. Complications were reported on a per- flap basis. Furthermore, overall complication rate was computed by adding all complications reported, and further subdivided in donor site and recipient site complications rates.
Statistical analysis
Data was processed for proportional meta-analysis using R software version 4.2.1 (R Foundation for Statistical Computing, Vienna, Austria) and its meta-package.
A random effect DerSimonian–Laird model was used to obtain pooled complication rates. Heterogeneity between studies was evaluated with the I² statistic along with the Q-statistic p-value, with I² with values below 30% considered as low heterogeneity and over 70% as significant heterogeneity.
Results are presented as forest plots with proportions and their 95% Confidence Intervals (CI).
Results
Five hundred thirty-one studies were identified through the initial database query (Fig. 1). After excluding duplicates and screening titles and abstracts, nineteen articles were fully read, yielding a total of seven studies that fully met the inclusion criteria.
Inferior gluteal artery perforator (IGAP) flap versus profunda artery perforator (PAP) flap as an alternative option for free autologous breast reconstruction.
A total of 239 IGAP procedures were performed in 181 patients. Clinical characteristics of the included studies are detailed in Table 3. All studies were of retrospective nature, except for Beshlian et al. that included prospective data after December 2006.
All studies cohort included surgical procedures conducted after the year 2001 and were of monocentric nature, apart from one study that was conducted across two major medical centers.
All studies focused primarily on IGAP, except for Jandali et al. where the primary aim was to test patency with venous coupler in different free flaps for breast reconstruction. Even if the primary aim was not the assessment of post-operative outcomes of the IGAP, its failure rate was reported, allowing for inclusion of the study. However, no specific details on Jandali et al. study population were available.
Inferior gluteal artery perforator (IGAP) flap versus profunda artery perforator (PAP) flap as an alternative option for free autologous breast reconstruction.
Inferior gluteal artery perforator (IGAP) flap versus profunda artery perforator (PAP) flap as an alternative option for free autologous breast reconstruction.
Inferior gluteal artery perforator (IGAP) flap versus profunda artery perforator (PAP) flap as an alternative option for free autologous breast reconstruction.
Inferior gluteal artery perforator (IGAP) flap versus profunda artery perforator (PAP) flap as an alternative option for free autologous breast reconstruction.
Inferior gluteal artery perforator (IGAP) flap versus profunda artery perforator (PAP) flap as an alternative option for free autologous breast reconstruction.
Inferior gluteal artery perforator (IGAP) flap versus profunda artery perforator (PAP) flap as an alternative option for free autologous breast reconstruction.
Inferior gluteal artery perforator (IGAP) flap versus profunda artery perforator (PAP) flap as an alternative option for free autologous breast reconstruction.
Inferior gluteal artery perforator (IGAP) flap versus profunda artery perforator (PAP) flap as an alternative option for free autologous breast reconstruction.
Inferior gluteal artery perforator (IGAP) flap versus profunda artery perforator (PAP) flap as an alternative option for free autologous breast reconstruction.
Inferior gluteal artery perforator (IGAP) flap versus profunda artery perforator (PAP) flap as an alternative option for free autologous breast reconstruction.
Inferior gluteal artery perforator (IGAP) flap versus profunda artery perforator (PAP) flap as an alternative option for free autologous breast reconstruction.
The recipient-site complication rate (Fig. 4) and overall complication rate (Fig. 5) reported in six studies, were 24% (95% CI: 15–34%) and 40% (95% CI: 23–58%) respectively.
Inferior gluteal artery perforator (IGAP) flap versus profunda artery perforator (PAP) flap as an alternative option for free autologous breast reconstruction.
Significant heterogeneity across studies (I2 > 70%) was observed for in the seroma rate, the donor-site complication rate, and the overall complication rate.
Fig. 2Forest plot of pooled IGAP total flap loss rate
Inferior gluteal artery perforator (IGAP) flap versus profunda artery perforator (PAP) flap as an alternative option for free autologous breast reconstruction.
Inferior gluteal artery perforator (IGAP) flap versus profunda artery perforator (PAP) flap as an alternative option for free autologous breast reconstruction.
Inferior gluteal artery perforator (IGAP) flap versus profunda artery perforator (PAP) flap as an alternative option for free autologous breast reconstruction.
Inferior gluteal artery perforator (IGAP) flap versus profunda artery perforator (PAP) flap as an alternative option for free autologous breast reconstruction.
Satake et al. reported other recipient-site complications that were not described in other studies, with partial nipple-areola-complex necrosis and hypertrophic scaring each occurring in 2 cases (3.2%). Sensory complaints at the donor site were reported in 7 patients (11.3%) in Satake et al. study and in 7 patients (23%) in Mirzabeigi et al. study. Paresthesia at the donor site was reported in 1 case (2.2%) in Levine et al. study, while Satake et al. described the presence of paresthesia in 3 cases out of 20 cases of bilateral IGAP flap reconstruction.
Discussion
To our knowledge, this study is the first systematic review and proportional meta-analysis evaluating surgical outcomes of the IGAP flap.
The IGAP total failure rate and partial failure rate were 3% and 2%, respectively. This rate remains comparable to other buttock and thigh flaps used in autologous breast reconstruction. A recent analysis on safety and efficacy of the SGAP flap showed pooled total and partial flap failure rates both at 1%.
Similarly, in thigh-based flaps – Qian et al. reported a pooled total flap loss rate of 1% and partial necrosis rate of 2% in their meta-analysis of the PAP flap, and a 2% pooled flap failure rate was reported by Siegwart et al. in their review of the TMG flap.
Safety and donor site morbidity of the transverse musculocutaneous gracilis (TMG) flap in autologous breast reconstruction—A systematic review and meta-analysis.
Large retrospective series of breast reconstruction with abdominally based flaps describe total flap failure rates ranging from 0.5% to 1.1% and partial flap loss rates ranging from 1.4% to 2.5%.
Comparison of Outcomes following Autologous Breast Reconstruction Using the DIEP and Pedicled TRAM Flaps: A 12-Year Clinical Retrospective Study and Literature Review.
Abdominal wall stability and flap complications after deep inferior epigastric perforator flap breast reconstruction: does body mass index make a difference? Analysis of 418 patients and 639 flaps.
In the present meta-analysis, significant hetereogenity was evidenced in seroma rate, donor-site complication rate, and overall complication rate – that may be explained by a lack of standardization in the reporting and definition of surgical complication and outcomes. It could also be explained by differences in surgeons experience with IGAP across different centres, with two included studies reporting the lowest complication rate coming from a centre that first described and previously studied the IGAP flap.
The pooled donor-site complication rate of 15% (95% CI: 5-28%) was similar to those reported in abdominally based flaps, thigh based flaps, and the SGAP flap.
Safety and donor site morbidity of the transverse musculocutaneous gracilis (TMG) flap in autologous breast reconstruction—A systematic review and meta-analysis.
Lessons Learned from 30 Years of Transverse Myocutaneous Gracilis Flap Breast Reconstruction: Historical Appraisal and Review of the Present Literature and 300 Cases.
The pooled overall complication rate was 40%, comparable to the 36% overall complication rate reported in a SGAP flap meta-analysis, and the 38.9% rate reported in studies on the FCI flap.
Beshlian et al. noted that while complications with the IGAP flaps are frequent, they often resolve without the need for surgical intervention with only 2 surgical revisions for 8 complications out of 19 flaps.
Noteworthily, the IGAP pooled fat necrosis rate was low at 2%, testifying the reliability of the flap perfusion, and favourably comparing to fat necrosis rates (10.4 to 12.9%) reported in large retrospective studies evaluating DIEP flap breast reconstruction.
Abdominal wall stability and flap complications after deep inferior epigastric perforator flap breast reconstruction: does body mass index make a difference? Analysis of 418 patients and 639 flaps.
Indeed, the IGAP vascular anatomy was described as reliable, with an adequate pedicle size, which varied across studies. Murphy et al. describe a median pedicle size of 7 cm (range: 6– 9 cm), Satake et al. report an average pedicle length of 4.6 cm (range: 3– 6.2 cm) and an average artery diameter of 1.4 mm (0.6 – 2.5 mm) while Allen et al. mention that the typical pedicle length ranges between 8 to 12 cm with an arterial diameter of more than 2 mm.
Inferior gluteal artery perforator (IGAP) flap versus profunda artery perforator (PAP) flap as an alternative option for free autologous breast reconstruction.
Variance in pedicle length and diameter across studies may be explained by differences in desired pedicle length and differences in patient’s BMI. Extension of dissection influences the length and diameter of the flap pedicle, with the caveat that deeper dissection increases operative difficulty and risk. Furthermore, the IGAP pedicle length can be increased by favouring lateral perforators.
The FCI flap provides comparable results to the SGAP and IGAP flaps, using a similar donor site but based on the vascular pedicle that accompanies the posterior femoral cutaneous nerve. The posterior femoral cutaneous pedicle is consistent and allows for greater lengths of up to 18 cm.
Furthermore, it has the added benefit of avoiding intra-muscular dissection, resulting in a less challenging surgery compared to the IGAP flap.
Use of preoperative imaging was reported inconsistently across studies – Murphy et al. and Satake et al. report the use of 3D computed tomography angiography (CTA) in the preoperative setting, while Mirzabeigi et al. note that while they do not routinely use it in breast reconstruction with abdominal flaps, they often use preoperative CTA or magnetic resonance angiography for gluteal flaps.
Inferior gluteal artery perforator (IGAP) flap versus profunda artery perforator (PAP) flap as an alternative option for free autologous breast reconstruction.
Inferior gluteal artery perforator (IGAP) flap versus profunda artery perforator (PAP) flap as an alternative option for free autologous breast reconstruction.
Some authors also mention vessel size mismatch as a disadvantage, that they address by exercising more caution when dissecting proximally, aiming to harvest smaller calibre veins to match recipient internal mammary vein.
Another pitfall reported by authors is sensory complaints in the posterior thigh region by patients following reconstruction that is a consequence of dissection and manipulation of the posterior femoral cutaneous nerve during surgery – although the symptoms were usually self-limiting and resolved without intervention.
Inferior gluteal artery perforator (IGAP) flap versus profunda artery perforator (PAP) flap as an alternative option for free autologous breast reconstruction.
Murphy et al. compared the outcomes following breast reconstruction with IGAP and PAP flaps and found that there were significantly more complications and revision surgeries in patients undergoing reconstruction with an IGAP flap.
Inferior gluteal artery perforator (IGAP) flap versus profunda artery perforator (PAP) flap as an alternative option for free autologous breast reconstruction.
Inferior gluteal artery perforator (IGAP) flap versus profunda artery perforator (PAP) flap as an alternative option for free autologous breast reconstruction.
Mirzabeigi et al. compared IGAP to DIEP and found that vascular complications were significantly more frequent in patients who underwent breast reconstruction with an IGAP flap.
Nevertheless, they state that they consider the IGAP flap as an excellent alternative option in patients unsuitable for abdominally based flap reconstruction.
All authors consider the IGAP flap as a second-line option for autologous breast reconstruction in patients with an inadequate abdominal donor site, in patients with previous abdominal surgeries or in patients preferring a gluteal based flap.
Inferior gluteal artery perforator (IGAP) flap versus profunda artery perforator (PAP) flap as an alternative option for free autologous breast reconstruction.
Regarding aesthetic outcomes, authors report that most patients are satisfied. Interestingly, Allen et al. note that when asked where excess tissue might be removed, many women with excess buttock tissue will indicate the lower portion of the buttocks.
Another aesthetic advantage over abdominally based flap reconstruction is the high fat-to-skin ratio and density of the IGAP flap, allowing for good breast projection.
Inferior gluteal artery perforator (IGAP) flap versus profunda artery perforator (PAP) flap as an alternative option for free autologous breast reconstruction.
Authors suggest that IGAP flap reconstruction offers better aesthetic results at the donor-site compared to SGAP flap reconstruction, due to its scar being located in the inferior buttock crease, making it less visible when nude. In contrast, SGAP flap scars are more prominent when not wearing underwear/bikini.
Another major advantage of the IGAP flap compared to the SGAP flap is a better donor site appearance, with no depression in the superior part of the buttock and thus less disturbance of the superior fullness.
Patients rated their buttock scar as satisfactory and their breast scar as good, and the buttock contour as somewhere between satisfactory and good. 72% of the surveyed patients indicated that they would undergo the same procedure again, while 14% stated they would have chosen the SGAP flap instead due to better coverage of the scar with a bathing suit.
Revision procedures at the donor site varied across studies, with Mirzabeigi et al. reporting that 39% of patients required local tissue rearrangement at the donor site, Murphy et al. noted a 17% donor site revision rate.
Inferior gluteal artery perforator (IGAP) flap versus profunda artery perforator (PAP) flap as an alternative option for free autologous breast reconstruction.
Similarly, revision procedures at the breast in Mirzabeigi et al. study were relatively high, with 31% of patients undergoing a local tissue rearrangement, compared to 10.5% in Satake et al. study.
This meta-analysis offers interesting insights. It indicates that the IGAP flap is safe in autologous breast reconstruction, with total and partial flap loss rates that are similar to other alternatives. While thigh-based flaps have grown in popularity over the last decade and have gradually replaced gluteal free flaps as a second-line option, the IGAP flap remains a valuable option for autologous breast reconstruction in patients with an inadequate abdominal donor site.
However, several limitations must be considered in this meta-analysis. The sample size was limited, and significant heterogeneity was evidenced in some of the analysed outcomes. Most of the included studies in this meta-analysis did not include objective and subjective assessment of the aesthetic results and overall patient satisfaction. Additionally, comparison between different flaps was performed using other proportional meta-analysis and retrospective studies. Further large comparative studies are required to draw definitive conclusions.
Conclusion
This meta-analysis provides comprehensive knowledge of surgical outcomes and complications of the IGAP flap. It demonstrates that it is both a safe and effective technique for autologous breast reconstruction.
Ethical approval
Not required.
Funding source
None
Funding
None
Conflict of interest
None
References
American Cancer Society | Cancer Facts & Statistics
American Cancer Society | Cancer Facts & Statistics.2023; (Accessed January 4) (Accessed January 4) (Accessed January 4)
Quality-of-life outcomes between mastectomy alone and breast reconstruction: comparison of patient-reported BREAST-Q and other health-related quality-of-life measures.
Should Immediate Autologous Breast Reconstruction Be Considered in Women Who Require Postmastectomy Radiation Therapy? A Prospective Analysis of Outcomes.
Quality of Life and Patient-Reported Outcomes in Breast Cancer Survivors: A Multicenter Comparison of Four Abdominally Based Autologous Reconstruction Methods.
Complications and Patient-Reported Outcomes after Abdominally Based Breast Reconstruction: Results of the Mastectomy Reconstruction Outcomes Consortium Study.
Inferior gluteal artery perforator (IGAP) flap versus profunda artery perforator (PAP) flap as an alternative option for free autologous breast reconstruction.
Safety and donor site morbidity of the transverse musculocutaneous gracilis (TMG) flap in autologous breast reconstruction—A systematic review and meta-analysis.
Comparison of Outcomes following Autologous Breast Reconstruction Using the DIEP and Pedicled TRAM Flaps: A 12-Year Clinical Retrospective Study and Literature Review.
Abdominal wall stability and flap complications after deep inferior epigastric perforator flap breast reconstruction: does body mass index make a difference? Analysis of 418 patients and 639 flaps.
Lessons Learned from 30 Years of Transverse Myocutaneous Gracilis Flap Breast Reconstruction: Historical Appraisal and Review of the Present Literature and 300 Cases.
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