The role of near-infrared fluorescence imaging with indocyanine green dye in pedicle division with the paramedian forehead flap

Early Division of the Paramedian Forehead Flap: A Systematic Review and Retrospective Analysis

OBJECTIVE

To determine whether and when early division of the paramedian forehead flap may be safely performed.

DATA SOURCES

PubMed (NLM), Scopus (Elsevier), and Embase (Elsevier).

METHODS

A systematic search of PubMed, Scopus, and Embase was conducted according to PRISMA guidelines. Data extraction included time to pedicle division, patient and defect characteristics, and postoperative complications. Additionally, a retrospective analysis of patients at our institution was performed to augment the cohort.

RESULTS

A total of 103 patients (85 from 6 studies identified via systematic review and 18 via retrospective review) underwent early flap division defined as 16 days and earlier. The average time to division was 9.89 days (3-16). There were no cases of flap loss, and complications were rare. Several studies excluded full thickness defects. Five studies included patients requiring cartilage grafting, although some limited this to less than 50% of the defect area. All patients in our retrospective cohort had partial thickness defects and none required cartilage grafting. Despite smoking being a major risk factor for vascular disease, 13.7% of patients were current smokers. Several studies utilized imaging tools such as indocyanine green angiography to assess flap perfusion. Notably, in these instances, no cases were delayed due to lack of adequate neovascularization.

CONCLUSION

Early paramedian forehead flap division may be an option in select patients with partial thickness nasal defects. Adjunct imaging may be a cost-effective method of evaluating appropriate timing of division.

LEVEL OF EVIDENCE

NA Laryngoscope, 2025.

The cross-leg free flap: A systematic review of the literature

BACKGROUND

Free tissue transfer is a mainstay treatment for lower extremity soft tissue injuries. When the traditional cross-leg flap cannot provide enough coverage, a cross-leg free flap (CLFF) is a limb-saving alternative. The aim of this study is to conduct a systematic review of the literature published on the CLFF.

METHODS

We conducted a systematic review of articles describing the CLFF, according to Preferred Reporting Items for Systematic Reviews and Meta-Analysis guidelines. Inclusion criteria included articles with primary data on the CLFF. Exclusion criteria included those describing pedicled cross-leg flaps or lacking complete data. Data analysis was performed using SPSS 29.0.

RESULTS

Our review included 28 articles encompassing 130 patients who underwent free tissue transfer. Most were male (63.8%) with a mean age of 32.4 years. Latissimus dorsi was the most common flap type (30.0%), followed by vertical rectus myocutaneous (20.0%). Average flap size was 301.8 cm2 , with trauma in the lower third of the leg being the most common indication (73.1%). The contralateral posterior tibialis was the most common recipient artery (84.1%) followed by the anterior tibialis (9.5%). Complications included amputation (1.4%), partial graft loss, thrombosis, hematoma, prolonged pain, nonunion, and seroma; a forest plot was used to illustrate the low overall adverse events rate. Although bivariate analysis identified age, flap size, type, location, and donor site as variables significantly impacting the incidence of complications (p < .05), this was not sustained in a multivariate logistic regression model.

CONCLUSION

The CLFF remains an excellent option for limb salvage when a suitable recipient vessel is unavailable. Our review demonstrates 1.4% flap failure and an acceptable complication rate. While most cases in our review describe muscle flaps, we report a complex case of limb salvage using an unusually large anterolateral thigh flap.

The Autonomization Principle in Vascularized Flaps: An Alternative Strategy for Composite Tissue Scaffold In Vivo Revascularization

Autonomization is a physiological process allowing a flap to develop neo-vascularization from the reconstructed wound bed. This phenomenon has been used since the early application of flap surgeries but still remains poorly understood. Reconstructive strategies have greatly evolved since, and fasciocutaneous flaps have progressively replaced muscle-based reconstructions, ensuring better functional outcomes with great reliability. However, plastic surgeons still encounter challenges in complex cases where conventional flap reconstruction reaches its limitations. Furthermore, emerging bioengineering applications, such as decellularized scaffolds allowing a complex extracellular matrix to be repopulated with autologous cells, also face the complexity of revascularization. The objective of this article is to gather evidence of autonomization phenomena. A systematic review of flap autonomization is then performed to document the minimum delay allowing this process. Finally, past and potential applications in bio- and tissue-engineering approaches are discussed, highlighting the potential for in vivo revascularization of acellular scaffolds.

NIR-II imaging with ICG for identifying perforators, assessing flap status and predicting division timing of pedicled flaps in a porcine model

The use of skin flaps to fill large defects is a key surgical technique in reconstructive surgery, effective real-time in vivo imaging for flap design and use is urgent. Currently, fluorescent imaging in the second NIR window (NIR-II; 1000-1700 nm) is characterized by non-radiation, less expensive and higher resolution in comparisons with the first NIR window (NIR-I; 700-900 nm) and other traditional imaging modalities. In this article, we identified the location and numbers of perforators and choke zone via NIR-II imaging. Then, eight abdominal perforator flaps were established and the perfusion zones were evaluatedat special time points. Finally, after eight pedicled flaps establishment, NIR-II imaging was used to guide the optimal timing for division of flap pedicle. The results showed that NIR-II fluorescence imaging with indocyanine green (ICG) can reliably visualize vascular supply, which makes it to be an accurate and in vivo imaging approach to flap clinical design and use.

Hyperintensity of integrin-targeted fluorescence agent IntegriSense750 accurately predicts flap necrosis compared to Indocyanine green

BACKGROUND

Flap necrosis is a feared complication of reconstructive surgery. Current methods of prediction using Indocyanine green (ICG) lack specificity. IntegriSense750 is a fluorescence agent that binds sites of vascular remodeling. We hypothesized that IntegriSense750 better predicts flap compromise compared to ICG.

METHODS

Fifteen mice underwent lateral thoracic artery axial flap harvest. Mice received an injection of ICG (n = 7) or IntegriSense750 (n = 8) daily from postoperative days (POD) 0-3 and were imaged daily. Mean signal-to-background ratios quantified the change in fluorescence as necrosis progressed.

RESULTS

Mean signal-to-background ratio was significantly higher for IntegriSense750 compared to ICG on POD0 (1.47 ± 0.17 vs. 0.86 ± 0.21, p = 0.01) and daily through POD3 (2.12 ± 0.70 vs. 0.96 ± 0.29, p < 0.001).

CONCLUSIONS

IntegriSense750 demonstrates increased signal-to-background ratio at areas of flap distress compared to ICG which may increase identification of flap necrosis and improve patient outcomes.