Dynamic infrared thermography and smartphone thermal imaging as an adjunct for preoperative, intraoperative, and postoperative perforator free flap monitoring

Abstract

Aim: The versatile application of perforator free flaps for coverage of any extremity has been well proven. Often, a “free-style”-like approach is used to design these flaps, as conventional imaging techniques for perforator identification may be too expensive or unavailable. As will be demonstrated, the recent application of a thermal imaging camera using a smartphone is a cheaper and therefore more universal means to better identify the requisite perforators upon which a free flap can be designed and then monitored.

Methods: Smartphone thermography can be used on any patient preoperatively to identify preferable perforators or vascular network “hot spots” within the desired donor site territory. Intraoperative management of the choice of perforators and subsequent flap dissection can be similarly facilitated. Intermittent postoperative monitoring based on changes of the thermal image color palette will provide a comparison that can be used to determine if perfusion across the microanastomosis is sustained.

Results: An overview of how to use a smartphone in concert with a thermal imaging camera is outlined. Dynamic infrared thermography represents a thermal stress necessary with a smartphone to better identify donor site “hot spots”.

Conclusion: Smartphone thermography is an inexpensive and expeditious means for identification of “hot spots” that correlate with perforators that would suffice to insure perfusion to a free perforator flap. However, since perforator caliber and course cannot be determined, this should be considered to be only a complementary adjunct for conventional methods. Nevertheless, its simplicity will overall improve the safer design, harvest, and subsequent monitoring of free flaps.

Keywords

Smartphone / thermography / thermal image camera / perforator free flap / microvascular tissue transfer / monitor

References

[1] Koerner S,Harper SL,Langemo DK.Use of thermal imaging to identify deep-tissue pressure inury on admission reduces clinical and fianancial burdens of hospital-acquired pressure injuries..Adv Skin Wound Care2019;32:312-20 PMCID:PMC6716560

[2] Theuvenet WJ,Borghouts MH.Thermographic assessment of perforating arteries: a preoperative screening method for fasciocutaneous and musculocutaneous flaps..Scand J Plast Reconstr Surg1986;20:25-9

[3] de Weerd L,Weum S.Dynamic infrared thermography..Clin Plast Surg2011;38:277-92

[4] de Weerd L,Mercer JB.The value of dynamic infrared thermography (DIRT) in perforator selection and planning of free DIEP flaps..Ann Plast Surg2009;63:274-9

[5] Muntean MV,Ardelean F.Dynamic infrared mapping of cutaneous perforators..J Xiangya Med2018;3:16

[6] Pereira N,Mangelsdorff G,Roa R.Detection of perforators for free flap planning using smartphone thermal imaging: a concordance study with computed tomographic angiography in 120 perforators..Plast Reconstr Surg2018;141:787-92

[7] Muntean MV.Detection of perforators for free flap planning using smartphone thermal imaging: a concordance study with computed tomographic angiography in 120 perforators..Plast Reconstr Surg2018;142:604e

[8] Tenorio X,Elias B,Wettstein.Locating perforator vessels by dynamic infrared imaging and flow doppler with no thermal cold challenge..Ann Plast Surg2011;67:143-6

[9] Saint Cyr M,Schaverien M,Rohrich RJ.The perforasome theory: vascular anatomy and clinical applications..Plast Reconstr Surg2009;124:1529-44

[10] Sheena Y,Hardwicke JT.Detection of perforators using thermal imaging..Plast Reconstr Surg2013;132:1603-10

[11] Hardwicke JT,Skillman JM.Detection of perforators using smartphonethermal imaging..Plast Reconstr Surg2016;137:39-41

[12] Pereira N.Reply: detection of perforators for free flap planning using smartphone thermal imaging: a concordance study with computed tomographic angiography in 120 perforators..Plast Reconstr Surg2018;142:605e

[13] de Weerd L,Setsá LB.Intraoperative dynamic infrared thermography and free-flap surgery..Ann Plast Surg2006;57:279-84

[14] Itoh Y.Use of recovery-enhanced thermography to localize cutaneous perforators..Ann Plast Surg1995;34:507-11

[15] Masia J,Clavero D,Vives L.Preoperative computed tomographic angiogram for deep inferior epigastric artery perforator flap breast reconstruction..J Reconstr Microsurg2010;26:21-8

[16] Masia J,Cervelli D,Monill JM.In search of the ideal method in perforator mapping: noncontrast magnetic resonance imaging..J Reconstr Microsurg2010;26:29-35

[17] Hallock GG.Doppler sonography and color duplex imaging for planning a perforator flap..Clin Plast Surg2003;30:347-57

[18] Chubb D,Whitaker IS.Digital thermographic photography (“thermal imaging”) for preoperative perforator mapping..Ann Plast Surg2011;66:324-5

[19] Holm C,Mayr M,Pfeiffer UJ.Monitoring free flaps using laser-induced fluorescence of indocyanine green: a preliminary experience..Microsurgery2002;22:278-87

[20] Muntean MV,Strilciuc S,Georgescu AV.Flap warming improves intraoperative indocyanine green angiography (ICGA) assessment of perfusion. an experimental study..J Plast Reconstr Aesthet Surg2019;72:1150-6

[21] Pereira N.SmartPhone thermagraphy for lower extremity local flap perforator mapping..J Reconstr Microsurg2020;pub pend

[22] Georgescu AV,Ardelean F.Microsurgical non-microvascular flaps in forearm and hand reconstruction..Microsurgery2007;27:384-94