Differential Perfusion Patterns of Perforator and Random Flaps Assessed by Indocyanine Green Imaging

Abstract

Background

Indocyanine green angiography (ICGA) is widely used to evaluate flap perfusion in reconstructive surgery, but the optimal timing for assessment may differ by flap type. This study compared the perfusion dynamics of perforator and random pattern flaps in a rat model using ICGA.

Methods

ICGA dynamics were compared between perforator and random flaps in a rat model. Sixteen Sprague–Dawley rats (275–300 g) were randomly assigned to either a perforator or a random flap group. A 0.25-mg dose of indocyanine green (ICG) was administered via the femoral vein, and fluorescence images were acquired at predefined intervals over 4 minutes. Hypoperfusion was defined as fluorescence intensity below 30% of the peak value. Necrosis was assessed on postoperative day 7. Statistical analyses included the Mann–Whitney U and log-rank tests with Expectation-Maximization Iterative Convex Minorant (EMICM) modeling.

Results

In the perforator flap group, the final area of necrosis corresponded to the ICGA-defined perfusion boundary observed between 10 and 50 seconds postinjection. In contrast, necrosis in the random flap group aligned with the ICGA-defined perfusion boundary captured between 30 and 150 seconds. The most accurate time points for necrosis prediction were 50 seconds for perforator flaps and 150 seconds for random flaps, both demonstrating statistical significance (p = 0.0028).

Conclusion

ICGA timing requirements differ between flap types. Implementing flap-specific assessment windows may enhance intraoperative interpretation and reduce false-positive findings. These findings support the development of flap-specific ICGA protocols to improve intraoperative decision-making in reconstructive surgery.

Keywords

perfusion - flap - indocyanine

^‡ These authors share first authorship.

Publication History

Received: 01 May 2025

Accepted: 09 September 2025

Accepted Manuscript online:
17 September 2025

Article published online:
08 October 2025

• References

• 1 Doldi PM, Stolz L, Buech J. et al. Indocyanine green clearance predicts outcome in patients undergoing transcatheter valve intervention for severe atrio-ventricular valve regurgitation. Interdiscip Cardiovasc Thorac Surg 2023; 36 (02) ivad024
• 2 Yannuzzi LA. Indocyanine green angiography: a perspective on use in the clinical setting. Am J Ophthalmol 2011; 151 (05) 745-751.e1
• 3 Narasaki H, Noji T, Wada H. et al. Intraoperative real-time assessment of liver function with near-infrared fluorescence imaging. Eur Surg Res 2017; 58 (5-6): 235-245
• 4 Huang SW, Ou JJ, Wong HP. The use of indocyanine green imaging technique in patient with hepatocellular carcinoma. Transl Gastroenterol Hepatol 2018; 3: 95
• 5 Pollmann L, Juratli M, Roushansarai N, Pascher A, Hölzen JP. Quantification of indocyanine green fluorescence imaging in general, visceral and transplant surgery. J Clin Med 2023; 12 (10) 3550
• 6 Burnier P, Niddam J, Bosc R, Hersant B, Meningaud JP. Indocyanine green applications in plastic surgery: A review of the literature. J Plast Reconstr Aesthet Surg 2017; 70 (06) 814-827
• 7 Bigdeli AK, Thomas B, Falkner F, Gazyakan E, Hirche C, Kneser U. The impact of indocyanine-green fluorescence angiography on intraoperative decision-making and postoperative outcome in free flap surgery. J Reconstr Microsurg 2020; 36 (08) 556-566
• 8 Li K, Zhang Z, Nicoli F. et al. Application of indocyanine green in flap surgery: A systematic review. J Reconstr Microsurg 2018; 34 (02) 77-86
• 9 Murono S, Ishikawa N, Ohtake H. et al. Intraoperative free jejunum flap monitoring with indocyanine green near-infrared angiography. Eur Arch Otorhinolaryngol 2014; 271 (05) 1335-1338
• 10 Holm C, Mayr M, Höfter E, Dornseifer U, Ninkovic M. Assessment of the patency of microvascular anastomoses using microscope-integrated near-infrared angiography: a preliminary study. Microsurgery 2009; 29 (07) 509-514
• 11 Phillips BT, Lanier ST, Conkling N. et al. Intraoperative perfusion techniques can accurately predict mastectomy skin flap necrosis in breast reconstruction: results of a prospective trial. Plast Reconstr Surg 2012; 129 (05) 778e-788e
• 12 Komorowska-Timek E, Gurtner GC. Intraoperative perfusion mapping with laser-assisted indocyanine green imaging can predict and prevent complications in immediate breast reconstruction. Plast Reconstr Surg 2010; 125 (04) 1065-1073
• 13 Jakubietz RG, Schmidt K, Bernuth S, Meffert RH, Jakubietz MG. Evaluation of the intraoperative blood flow of pedicled perforator flaps using indocyanine green-fluorescence angiography. Plast Reconstr Surg Glob Open 2019; 7 (09) e2462
• 14 Moyer HR, Losken A. Predicting mastectomy skin flap necrosis with indocyanine green angiography: the gray area defined. Plast Reconstr Surg 2012; 129 (05) 1043-1048
• 15 Mothes H, Dönicke T, Friedel R, Simon M, Markgraf E, Bach O. Indocyanine-green fluorescence video angiography used clinically to evaluate tissue perfusion in microsurgery. J Trauma 2004; 57 (05) 1018-1024
• 16 An S, Ferraro GA, Garvery PB. Indocyanine green angiography for flap mornitoring: current use and future direction. J Reconstr Microsurg 2021; 37: 189-198
• 17 Turnbull BW. The empirical distribution function with arbitrarily grouped, censored and truncated data. J R Stat Soc B 1997; 38: 290-295
• 18 Wellner JA, Zhan Y. A hybrid algorithm for computation of the nonparametric maximum likelihood estimator from censored data. J Am Stat Assoc 1997; 92: 945-959
• 19 Sun J. A non-parametric test for interval-censored failure time data with application to AIDS studies. Stat Med 1996; 15 (13) 1387-1395
• 20 Mordon S, Devoisselle JM, Soulie-Begu S, Desmettre T. Indocyanine green: physicochemical factors affecting its fluorescence in vivo. Microvasc Res 1998; 55 (02) 146-152
• 21 Arai K, Nagasawa A, Sato S. Usability of the thermorecovery technique in the formation of skin flaps (especially, axial pattern flap). Biomed Thermogr. 1985; 5: 94
• 22 Rozen WM, Ashton MW, Le Roux CM, Pan WR, Corlett RJ. The perforator angiosome: a new concept in the design of deep inferior epigastric artery perforator flaps for breast reconstruction. Microsurgery 2010; 30 (01) 1-7
• 23 Cormack GC, Lamberty BGH. The Arterial Anatomy of Skin Flaps. Edinburgh: Churchill Livingstone; 1994
• 24 Mardini S, Tsai FC, Yang JC. et al. Vascular perfusion of free-style flaps: an in vivo study. Plast Reconstr Surg 2004; 114: 1027-1037
• 25 Chen HC, Tang YB, Noordhoff MS. Microvascular anatomy and blood flow in different types of skin flaps. Ann Plast Surg 1990; 24: 401-408
• 26 Nakajima H, Imanishi N, Aiso S. Vascular anatomy of the skin and the design of flaps. Clin Plast Surg 2003; 30: 261-286