The Intra.Ox Near-Infrared Spectrometer Measures Variations in Flap Oxygenation That Correlate to Flap Necrosis in a Preclinical Rodent Model

Mastectomy Skin Flap Perfusion Assessment Prior to Breast Reconstruction: A Narrative Review

BACKGROUND

Predicting the viability of the skin flaps after mastectomy is of high importance and significance in immediate breast reconstruction. Numerous methods have been used and are readily available. This review aims to describe and compare the current preferred perfusion assessment tools.

METHODS

Four major scientific databases-Web of Science, PubMed, Embase, and Scopus-were consulted to retrieve reviews, meta-analyses, clinical trials, experimental studies, and case reports focused on skin flap perfusion assessment following mastectomy. English-language articles published within the last 10 years were included. The most recent search was conducted on 31 July 2024.

RESULTS

A summary focused on the relevant information of all included studies was drafted, and the results of the studies have been synthetized and compared. A total of 58 studies have been included in this review.

CONCLUSION

Indocyanine green angiography (ICG-A) is the preferred and most-used method of evaluating perfusion, especially in high-risk patients, while new technologies show promising results and might be of great interest in the future. Perfusion assessment tools complement and should not replace clinical evaluation.

Point-of-Care Tissue Oxygenation Assessment with SnapshotNIR for Alloplastic and Autologous Breast Reconstruction

In breast reconstruction, mastectomy and free flaps are susceptible to vascular compromise and tissue necrosis. The SnapshotNIR device (Kent Imaging, Calgary, AB, Canada) utilizes near-infrared spectroscopy to measure tissue oxygen saturation (StO₂) and hemoglobin concentration. Here, we report on the use of this device for StO₂ monitoring among patients receiving alloplastic or autologous breast reconstruction.

Methods

Patients receiving immediate alloplastic reconstruction after mastectomy or autologous reconstruction were enrolled. Preoperative, intraoperative, and postoperative images were taken of the flaps. StO₂ and hemoglobin were measured at the following locations: superior and inferior breast, free flap skin paddle (when applicable), and un-operated control skin. Linear mixed effects model for repeated measurements was used to model measurements to estimate the area effect difference across time, time effect difference across area, and pairwise comparisons between two areas at each time point.

Results

Thirty-two breasts underwent alloplastic reconstruction; 38 breasts underwent autologous reconstruction. No enrollees developed skin necrosis. StO₂ was highest after mastectomy and closure in alloplastic reconstructions. StO₂ was observed to decline at follow-up in autologous reconstructions. Mean preoperative StO₂ was highest in breasts that had previously undergone mastectomy and alloplastic reconstruction.

Conclusions

The SnapshotNIR device detected normal spatial and temporal differences in tissue oxygenation over the operative course of alloplastic and autologous breast reconstruction. A multi-institutional, prospective clinical trial is needed to determine the sensitivity and specificity of this device for detecting skin flap necrosis.

Breast Reconstruction Trends in the Setting of Postmastectomy Radiation Therapy: Analysis of Practices among Plastic Surgeons in the United States

Radiation is an integral part of breast cancer therapy. The ideal type and timing of breast reconstruction with relation to radiation delivery are not well established. The study aimed to identify reconstructive practices among American plastic surgeons in the setting of pre- and postmastectomy radiation.

Methods

A cross-sectional survey of members of the American Society of Plastic Surgery was performed. Practice/demographic information and breast reconstruction protocols were queried. Univariate descriptive statistics were calculated, and outcomes were compared across cohorts with χ² and Fischer exact tests.

Results

Overall, 477 plastic surgeons averaging 16.3 years in practice were surveyed. With respect to types of reconstruction, all options were well represented, although nearly 60% preferred autologous reconstruction with prior radiation and 55% preferred tissue expansion followed by implant/autologous reconstruction in the setting of unknown postoperative radiation. There was little consensus on the optimal timing of reconstruction in the setting of possible postoperative radiation. Most respondents wait 4-6 or 7-12 months between the end of radiation and stage 2 implant-based or autologous reconstruction. Common concerns regarding the effect of radiation on reconstructive outcomes included mastectomy flap necrosis, wound dehiscence, capsular contracture, tissue fibrosis, and donor vessel complications.

Conclusions

Despite considerable research, there is little consensus on the ideal type and timing of reconstruction in the setting of pre- and postoperative radiation. Understanding how the current body of knowledge is translated into clinical practice by different populations of surgeons allows us to forge a path forward toward more robust, evidence-based guidelines for patient care.

Current Status of Experimental Animal Skin Flap Models: Ischemic Preconditioning and Molecular Factors

Skin flaps are necessary in plastic and reconstructive surgery for the removal of skin cancer, wounds, and ulcers. A skin flap is a portion of skin with its own blood supply that is partially separated from its original position and moved from one place to another. The use of skin flaps is often accompanied by cell necrosis or apoptosis due to ischemia-reperfusion (I/R) injury. Proinflammatory cytokines, such as nuclear factor kappa B (NF-κB), inhibitor of kappa B (IκB), interleukin-6 (IL-6), tumor necrosis factor-α (TNF-α), and oxygen free radicals are known causative agents of cell necrosis and apoptosis. To prevent I/R injury, many investigators have suggested the inhibition of proinflammatory cytokines, stem-cell therapies, and drug-based therapies. Ischemic preconditioning (IPC) is a strategy used to prevent I/R injury. IPC is an experimental technique that uses short-term repetition of occlusion and reperfusion to adapt the area to the loss of blood supply. IPC can prevent I/R injury by inhibiting proinflammatory cytokine activity. Various stem cell applications have been studied to facilitate flap survival and promote angiogenesis and vascularization in animal models. The possibility of constructing tissue engineered flaps has also been investigated. Although numerous animal studies have been published, clinical data with regard to IPC in flap reconstruction have never been reported. In this study, we present various experimental skin flap methods, IPC methods, and methods utilizing molecular factors associated with IPC.