The Value of BMI for Breast Reconstructions with the SIEA Flaps: Predicting the Ideal Intercostal Plane for the End-to-End Microvascular Anastomosis and the Possibility of Utilizing the TDA as a Salvage Recipient Choice

BACKGROUND

The superficial inferior epigastric artery (SIEA) diameter and the matching degree between the donor and the recipient arteries in terms of diameter are key factors affecting the outcome of the procedure in breast reconstructions with the SIEA flaps. A diameter of the SIEA ≥ 1.5 mm and a matching degree ≥ 1:2 (50%) of the diameters of the donor and the recipient arteries are recognized standards for the SIEA and the internal mammary artery (IMA) to achieve an end-to-end anastomosis. However, further refinements of the population characteristics and the ideal microscopic anastomosis intercostal planes are currently lacking for the criteria.

METHODS

In this study, based on 20 sides of hemiabdomen with computed tomography angiography (CTA) data suggesting the presence of the SIEA, we analysed the diameters of the donor and the recipient arteries as well as their matching degrees. The correlations between the parameters above and body mass index (BMI) were assessed. Based on the lower bounds of the 95% confidence intervals of the matching degrees and the two critical nodes of 50% and 67%, we theoretically evaluated the possibility of an end-to-end anastomosis of the SIEA and the IMA at different levels of BMIs and intercostal spaces, and predicted the possible intraoperative management measures for the SIEA.

RESULTS

The SIEA diameter, the thoracodorsal artery (TDA) diameter, and the diameters of the IMA at the 2nd to the 5th intercostal levels were positively correlated with the BMI (p < 0.05). A value of BMI ≥ 24 kg/m² could indirectly reflect the application premise of the diameter of the SIEA ≥ 1.5 mm. The matching degrees of the SIEA with the TDA or the IMA at the 2nd to the 5th intercostal level were linearly and positively correlated with the BMI (p < 0.001). Based on the confidence interval analysis, we predicted different management techniques that might be needed intraoperatively for the SIEA at different BMI levels, when the SIEA and the IMA or the TDA were to be anastomosed in an end-to-end way.

CONCLUSION

For patients with preoperative CTA data suggesting the presence of the SIEA in the second-stage breast reconstructions, when a value of BMI ≥ 24 kg/m² is met, the SIEA and the IMA can theoretically achieve an end-to-end anastomosis at the 3rd to the 5th intercostal level, and when 24 kg/m²≤ BMI ≤ 25 kg/m², due to the large difference in diameters, the SIEA and the IMA at the 2nd intercostal level might need to adopt an end-to-side anastomosis or switch to the TDA recipient site. Based on this study's findings and aesthetic effect considerations, we think that the 3rd and the 4th intercostal planes are ideal choices for the end-to-end anastomosis. As a salvage recipient option, the TDA can theoretically achieve an end-to-end anastomosis with the SIEA at a value of BMI ≥ 24 g/m².

LEVEL OF EVIDENCE IV

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The Impact of Abdominal Liposuction on Abdominally Based Autologous Breast Reconstruction: A Systematic Review

Prior abdominal liposuction can be viewed as a relative or absolute contraindication to abdominally based autologous breast reconstruction given concerns for damaged perforators and scarring complicating intraoperative dissection. This systematic review aims to explore the outcomes of abdominally based breast reconstruction in patients with a history of abdominal liposuction. A Preferred Reporting Items for Systematic Reviews and Meta-Analyses-guided literature search was conducted using PubMed, Scopus, and Web of Science from the earliest available date through June 2020. Deep inferior epigastric perforator, muscle-sparing transverse rectus abdominis musculocutaneous (TRAM), superficial inferior epigastric artery, and pedicled TRAM flaps were included for evaluation. Complications included total or partial flap loss, fat necrosis, seroma, delayed wound healing, and donor site complications. After inclusion criteria were applied, 336 nonduplicate articles were screened, yielding 11 for final review, representing 55 flaps in 43 patients. There was no instance of total flap loss, eight (14.5%) flaps developed partial loss or fat necrosis, three (5.4%) flaps had delayed wound healing, and two (4.6%) patients had donor site complications. Most authors (8/11) utilized some type of preoperative imaging. Doppler ultrasonography was the most used modality, and these patients had the lowest rate of partial flap loss or flap fat necrosis (8%), followed by those without any preoperative imaging (10%). In conclusion, this review supports that patients undergoing abdominally based autologous breast reconstruction with a history of abdominal liposuction are not at an increased risk of flap or donor site complications. Although preoperative imaging was common, it did not reliably decrease complications. Further prospective studies are needed to address the role of imaging in improving outcomes.

Current Applications of Ultrasound Imaging in the Preoperative Planning of DIEP Flaps

Background The deep inferior epigastric artery perforator (DIEP) flap has become the gold standard for autologous breast reconstruction at many institutions. Although the deep inferior epigastric artery displays significant anatomic variability in its intramuscular course, branching pattern and location of perforating vessels, the ability to preoperatively visualize and map relevant vascular anatomy has increased the efficiency, safety and reliability of the DIEP flap. While computed tomography angiography (CTA) is often cited as the preoperative imaging modality of choice for perforator flaps, more recent advances in ultrasound technology have made it an increasingly attractive alternative.

Methods An extensive literature review was performed to identify the most common applications of ultrasound technology in the preoperative planning of DIEP flaps.

Results This review demonstrated that multiple potential uses for ultrasound technology in DIEP flap reconstruction including preoperative perforator mapping, evaluation of the superficial inferior epigastric system and as a potential adjunct in flap delay procedures. Available studies suggest that ultrasound compares favorably to other widely-used imaging modalities for these indications.

Conclusion This article presents an in-depth review of the current applications of ultrasound in the preoperative planning of DIEP flaps and explores some potential areas for future investigation.

Deep Inferior Epigastric Artery Perforator Flap Breast Reconstruction in the Setting of Cryolipolysis

The deep inferior epigastric artery perforator (DIEP) flap is a safe and reliable autologous breast reconstruction option for patients undergoing surgical treatment for breast cancer. Success of the procedure relies on adequate flap perfusion from perforators that travel within the subcutaneous layer of the abdominal wall. Patients who have undergone invasive abdominal wall procedures such as suction-assisted liposuction may therefore be at increased risk of postoperative complications such as flap loss and fat necrosis. In recent years, noninvasive fat-reduction techniques such as cryolipolysis have grown immensely in popularity. However, there are no data regarding outcomes for patients who have undergone DIEP flap breast reconstruction after having previously undergone abdominal cryolipolysis. The current case demonstrates that free flap breast reconstruction can be performed safely in this patient population, and that adjunct imaging modalities may improve clinical decision-making.

Indocyanine Green Angiography Predicts Tissue Necrosis More Accurately Than Thermal Imaging and Near-Infrared Spectroscopy in a Rat Perforator Flap Model

BACKGROUND

Clinical examination alone is neither sensitive nor specific for predicting flap necrosis, so several technologies, including indocyanine green angiography, thermal imaging (using the FLIR ONE), and near-infrared spectroscopy, have been developed to supplement perfusion assessment. This study aims to compare the accuracy of these three methods for intraoperatively predicting clinical flap necrosis in a rat perforator flap model. The authors hypothesized that near-infrared spectroscopy, assessing oxygenation rather than direct perfusion, would yield significantly different predictions.

METHODS

A 10 × 3-cm epigastric perforator flap was elevated in 14 adult male rats weighing 250 ± 50 g. Flap perfusion was assessed immediately after flap elevation using thermal imaging, near-infrared spectroscopy, and indocyanine green angiography. Measurements were correlated to the clinical endpoint and gold standard of flap necrosis on postoperative day 7.

RESULTS

All three technologies detected significant differences in perfusion along flap length (all p < 0.001), and were associated with significant differences in the odds of developing flap necrosis (all p < 0.001). The areas under the receiver operating characteristic curves were 0.948 for indocyanine green angiography as an absolute value, 0.873 for relative changes with thermal imaging, and 0.792 for tissue oxygenation. The sensitivity, specificity, and accuracy for indocyanine green angiography measured as an absolute value were the highest at 97.8, 87.5, and 92 percent, respectively.

CONCLUSIONS

Indocyanine green angiography most accurately predicted flap necrosis in this study; however, tissue oximetry and thermal imaging were also capable of predicting necrosis and represented potentially less expensive or more readily available alternatives for objective perfusion assessment. Additional research can further delineate their roles and cost-efficacy in clinical practice.

How to Maximize Aesthetics in Autologous Breast Reconstruction

With continuous technical and functional advances in the field of breast reconstruction, there is now a greater focus on the artistry and aesthetic aspects of autologous reconstruction. Whereas once surgeons were most concerned with flap survival and vessel patency, they are now dedicated to reconstructing a similarly or even more aesthetically pleasing breast than before tumor resection. We discuss the approach to shaping the breast through the footprint, conus, and skin envelope. We then discuss how donor site aesthetics can be optimized through flap design, scar management, and umbilical positioning. Each patient has a different perception of their ideal breast appearance, and through conversation and counseling, realistic goals can be set to reach optimal aesthetic outcomes in breast reconstruction.

Partial DIEP flap loss in a patient with history of abdominal liposuction

Classically, history of prior abdominal liposuction has been considered a relative contraindication for breast reconstruction using deep inferior epigastric perforator (DIEP) flap. The rationale for this is based on the fact that liposuction can possibly damage perforating vessels, which could compromise flap survival. However, multiple recently published reports have shown that imaging using CT angiography or colour Duplex ultrasonography could be used to accurately assess the adequacy of the perforating vessels before DIEP flap harvest. This contraindication is currently being reconsidered in the scientific literature. We present a case of partial DIEP flap loss in a patient with history of abdominal liposuction that happened despite preoperative identification of adequate perforators using CT angiography and intraoperative clear evidence of patent anastomoses. This occurrence reopens in our view the question of whether DIEP flaps can be safely performed on patients with a history of abdominal liposuction, even in the presence of adequate perforators on regular CT angiography or Doppler ultrasonography. While abdominal liposuction may not injure perforating vessels, its detrimental effect on linking micro-vessels within the flap cannot be fully evaluated using CT Angiography. Therefore, the use of another imaging modality, such as the indocyanine green laser angiography, to assess perfusion before DIEP flap harvesting is performed and could be considered in patients with history of abdominal liposuction.