Locating Perforator Vessels by Dynamic Infrared Imaging and Flow Doppler With No Thermal Cold Challenge

Projected augmented reality in DIEP flap breast reconstruction: Projecting perforators on the skin using dynamic infrared thermography

BACKGROUND

Dynamic infrared thermography (DIRT) is a quick and non-invasive technique for perforator mapping in free flaps that provides real-time information. After a cold challenge, areas best supplied with blood become visible hotspots on color-coded maps, indicating perforators. This study presents a proof of principle for a new and innovative feature of DIRT, where projected augmented reality is used to directly display thermal images on the patient's abdomen prior to the deep inferior epigastric artery perforator (DIEP) flap breast reconstruction.

METHODS

A self-aligning projection device prototype (Anatomy Projector) equipped with an integrated thermal camera was used to obtain thermal information and project the color-coded map directly on the patient's abdomen before DIEP flap breast reconstruction. Projected DIRT hotspots were verified using a hand-held Doppler, and compared to the vascularity on computed tomography angiography (CTA), and intraoperative perforator measurements following a Cartesian grid.

RESULTS

A total of 514 DIRT hotspots were projected in 50 patients, among them 97.3% could be verified using Doppler. The positive predictive value for CTA was 74.5%. Intraoperative measurements yielded 132 perforators in 71 flaps, among them 75 perforators (56.8%) correlated with projected DIRT hotspots, and half of them (54.7%) appeared within the first 5 emerging hotspots.

CONCLUSION

This study showed that real-time display of thermal data in DIEP flap breast reconstruction is feasible via projected augmented reality. Projection facilitates convenient marking of hotspots, and a high resemblance to Doppler and CTA data was observed. Further research should assess the added value of projecting thermal images intraoperatively and in other fields of plastic surgery.

Thermal Challenges in Dynamic Infrared Thermography Used for Perforator Mapping

BACKGROUND

 The aim of this study is to investigate the different approaches to thermal challenges, both cold and warm, used in dynamic infrared thermography for reconstructive surgery, and explore whether it affects the success of preoperative perforator mapping.

METHODS

 Literature was collected from Ovid Medline, Embase, PubMed, and Cochrane. The references of the full-text articles located from the original search were also appraised. Thirteen articles were extracted for the final qualitative analysis. A systematic review was then conducted following the PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) guidelines.

RESULTS

 Thirteen articles looked at a cold challenge, which included airflow cooling, direct contact cooling, and evaporation-based cooling. Two articles investigated warm challenges. One paper used no challenge, suggesting it unnecessary with a highly sensitive camera. All cold challenges were positively supported by a high level of flap perfusion success and/or a high level of correlation with other forms of investigation.

CONCLUSION

 Cold challenges were overall superior to no challenge and warm challenges; however, this conclusion is limited by the small participant size, the possibility of detection bias, and poor methodology detailing. Airflow cooling-specifically, using a desktop fan to blow air for 2 minutes-was noted to likely cause the least discomfort due to a low cooling capacity yet simultaneously maintain effectiveness and allow for a uniform cooling application. Warm challenges showed less conclusive results and were restricted by lack of studies. This topic would benefit from larger scale studies that compare multiple approaches while using standardized equipment to eliminate confounding factors.

The application of infrared thermography technology in flap: A perspective from bibliometric and visual analysis

The application of infrared thermography technology (IRT) in flap has become a major focus of research, as it provides a non-invasive, real-time, and quantitative approach for monitoring flap perfusion. In this regard, we conducted a comprehensive visualization and scientometric analysis to systematically summarize and discuss the current state of research in this field. We systematically reviewed publications on the application of IRT in flap procedures from 1999 to 2022, using the Web of Science Core Collection (WoSCC). Through scientometric analysis, we examined annual trends, affiliations, countries, journals, authors, and their relationships, providing insights into current hotspots and future developments in this area. We analysed 522 English studies and found a steady increase in annual publications. The United States and Germany had the highest publication rates, with Beth Israel Deaconess Medical Center and Shanghai Jiaotong University being leading institutions. Notably, Lee BT and Alex Keller emerged as influential authors in this field. Compared to existing techniques, infrared-based technology offers significant advantages for non-invasive monitoring of flap perfusion, including simplicity of operation and objective results. Future trends should focus on interdisciplinary collaborations to develop new infrared devices and achieve intelligent image processing, enabling broader application in various clinical scenarios. This bibliometric study summarizes the progress and landscape of research on 'the Application of infrared thermography technology in flap' over the past two decades, providing valuable insights and serving as a reliable reference to drive further advancements and spark researchers' interest in this field.

The Use of Thermal Imaging in Free Perforator Flap Planning

Background. Preoperative planning and design of microsurgical perforator flaps are the main steps for successful operation. The aim of this study was to determine the concordance between thermographic images obtained with smartphone thermal imaging camera and hand-held Doppler in the anterolateral thigh flap (ALT) model. Methods. A concordance study of diagnostic tests was carried out in Hospital of Lithuanian University of Health Sciences Kaunas Clinics, Plastic and Reconstructive Surgery Department during 2020–2022. Patients’ who were scheduled to undergo reconstruction with ALT flap and healthy volunteers were included in the study. Dynamic thermal images were performed with smartphone thermal camera FLIR One PRO in the typical ALT flap territory. The number and distance of hotspots in the thermogram with respect to anterior superior iliac spine were recorded in the study protocol. Later, the examination was repeated with hand-held Doppler and the control of hotspot was performed. Sensitivity, specificity and concordance index calculations were performed. Statistical analysis was performed using IMB SPSS 23.0. Results. A total of 100 ALT flap territories were examined. 266 hotspots were detected with thermal imaging and 275 perforators with hand-held Doppler. In 96.6% of cases, hotspots detected by a thermal camera were confirmed by hand-held Doppler as perforators. The sensitivity and specificity of thermography for the detection of perforators with respect to the hand-held Doppler were 93.5% and 96.9% respectively. The measure of concordance kappa index was 0.095 (p = 0.001). Conclusion. Smartphone thermal imaging have a high concordance with hand-held Doppler in perforator mapping, thus could be considered a useful adjunct to conventional methods.

Thermography Supported Color Duplex Ultrasound Accelerates ALT Perforator Imaging

BACKGROUND

 The anterolateral thigh flap is a versatile and dependable perforator flap and is a popular choice in the reconstruction of various body sites. The variable perforator anatomy suggests preoperative perforator imaging to improve safety and speed of dissection. An innovative perforator imaging technique is thermography, which lately gained attention in plastic surgery.

METHODS

 Thirty-two healthy participants were included in this randomized study. One thigh was examined with dynamic infrared thermography and consecutively with ultrasound, while the contralateral thigh was examined with ultrasound as standalone technology.

RESULTS

 The application of dynamic infrared thermography prior to ultrasound perforator identification significantly accelerated the ultrasound examination duration by 90 to 130 seconds. The mean duplex ultrasound examination duration correlated positively with the hotspot and perforator quantity per thigh.

CONCLUSION

 The addition of thermographic perforator mapping can accelerate color duplex ultrasound anterolateral thigh perforator imaging. Furthermore, thermography supplements color duplex ultrasound with crucial information on angiosome location.

Deep inferior epigastric perforator flap preoperative planning: A comparative analysis between dynamic infrared thermography, computerized tomography angiography, and hand-held Doppler

INTRODUCTION

Hand-held Doppler (HHD) sonography and computerized tomography angiography (CTA) are the common assessment tools for deep inferior epigastric perforator (DIEP) flap preoperative planning. CTA is considered the gold standard method for preoperative perforator mapping but necessitates contrast medium and X-ray exposure. Dynamic infrared thermography (DIRT) does not have these drawbacks and allows the detection of hot and cold spots on a given body area. Our study aimed to compare DIRT, HHD, and CTA in perforator mapping for breast reconstruction using DIEP flap.

PATIENTS AND METHODS

From March to September 2020, 12 consecutive patients scheduled for DIEP flap breast reconstruction were preoperatively investigated with HHD, CTA, and DIRT. The patients' mean age was 53 and the mean BMI was 29.23 kg/m² . All the reconstructions were due to breast cancer. The results of preoperative perforator mapping on the lower abdomen were compared among the three techniques. All the evidence was compared to the intraoperative findings, during flap harvesting, to establish if the techniques were able to correctly locate the perforator.

RESULTS

We detected 178 perforators intraoperatively, 178 with CTA, 178 with DIRT, and 125 with HHD. The latter revealed a lower number of perforator vessels for each patient (10.42 ± 3.58), compared with CTA (14.83 ± 3.04) and DIRT (14.83 ± 4.76). DIRT resulted superior to HHD (p < .05), while no statistically significant difference (p > .05) was found between DIRT and CTA. We calculated a mean sensitivity of 93.87% for CTA, 69.02% for HHD, and 92.06% for DIRT.

CONCLUSION

DIRT is a useful tool in the preoperative planning of DIEP flaps, as it provides information about the location of perforators and the hemodynamic properties of angiosomes. It is easy to use, and it does not involve ionizing radiation. DIRT could represent an innovative and promising implementation of CTA and HHD techniques for preoperative perforator mapping in DIEP breast reconstruction.

Thermal, Hyperspectral, and Laser Doppler Imaging: Non-Invasive Tools for Detection of The Deep Inferior Epigastric Artery Perforators-A Prospective Comparison Study

Perforator flaps have become one of the leading procedures in microsurgical tissue transfer. Individual defects require a tailored approach to guarantee the most effective treatment. A thorough understanding of the individual vascular anatomy and the location of prominent perforators is of utmost importance and usually requires invasive angiography or at least acoustic Doppler exploration. In this study, we aimed at evaluating different non-invasive imaging modalities as possible alternatives for perforator location detection. After a cooling phase, we performed thermal, hyperspectral and Laser Doppler imaging and visually evaluated a possible detection of the perforator for a period of five minutes with an image taken every minute. We identified the most prominent perforator of the deep inferior epigastric artery by handheld acoustic Doppler in 18 patients. The detected perforator locations were then correlated. Eighteen participants were assessed with six images each per imaging method. We could show a positive match for 94.44%, 38.89%, and 0% of patients and 92.59%, 25.93%, and 0% of images for the methods respectively compared to the handheld acoustic Doppler. Sex, age, abdominal girth, and BMI showed no correlation with a possible visual detection of the perforator in the images. Therefore, thermal imaging can yield valuable supporting data in the individualized procedure planning. Future larger cohort studies are required to better assess the full potential of modern handheld thermal imaging devices.

Perforator Detection by Thermographic Imaging Augmented With Tourniquet-Reperfusion: A Modified Approach and Preliminary Report in Distal Lower Leg Reconstruction

BACKGROUND

Dynamic infrared thermography provides a new imaging method of perforator detection. This study introduces an augmented technique to improve its accuracy by tourniquet-reperfusion and reports its preliminary use in the distal lower leg reconstruction.

METHODS

A tourniquet (450 mm Hg) was applied for 3 minutes on proximal thighs. After the tourniquet release, the rewarming rate and pattern of hotspots were observed by thermography to delineate the location and quality of perforators. The results were compared with those detected by computed tomographic angiography. Clinically, the local transferred posterior tibial artery or peroneal artery propeller perforator flap was performed in 9 patients for the distal lower leg reconstruction.

RESULTS

There was a 20- to 140-second "perforator observing window" after the tourniquet release. Tourniquet-reperfusion augmented thermal imaging method (TRATIM) had a sensitivity of 90.3% and a positive predictive value of 93.3%. The TRATIM and computed tomographic angiography had an excellent concordance with a kappa index value of 0.839 (P < 0.001). Based on the TRATIM, 9 propeller perforator flaps were successfully designed and raised for the distal lower leg resurfacing. All flaps survived entirely, except one with size of 1.0 cm × 2.0 cm that had terminal necrosis.

CONCLUSIONS

The TRATIM is a quick, easy, cheap, and reliable approach for perforator detection in the lower leg. With the aid of TRATIM, a customized propeller perforator flap could be raised efficiently for the distal lower leg reconstruction.

Air Flow Cooling Improves Anterolateral Thigh Perforator Mapping Using the FLIR ONE Thermal Camera

BACKGROUND

 Due to the variable vascular anatomy preoperative perforator mapping facilitates anterolateral thigh (ALT) free flap harvesting. Dynamic infrared perforator imaging can assist preoperative planning by displaying hot spots that represent angiosomes. This study aims to compare previously described precooling methods to develop a standardized simplified protocol for ALT perforator planning.

METHODS

 Fifty thighs were examined with a FLIR ONE thermal camera. Four different cold challenges, including alcoholic disinfection, wet laparotomy sponge cooling, fan cooling, and cold pack application, were compared. Hot spot locations within a 250 mm × 80 mm area were compared double-blinded to perforator locations determined by Doppler ultrasonography considered as gold standard.

RESULTS

 The matching rate of thermographic hot spots and sonographically identified perforators was 34.9 ± 22.2%. An increased matching rate of 62.2 ± 42.2% was noted taking only favored perforators (septocutaneous course, diameter >1 mm, distance <3 cm to the center, and visible concomitant veins) into account. Precooling with a fan followed by alcoholic disinfection provided clearest thermograms and fastest results.

CONCLUSION

 Thermographic imaging is a reliable method for perforator imaging. Its supplemental use to ultrasound may reduce examination time and yield additional information. Precooling by air flow or alcoholic disinfection can be easily implemented and provide the best thermograms. The matching rate of thermographic hot spots and perforators increases when taking only clinically relevant perforators into account. Thermal perforator mapping therefore reduces distraction by negligible perforators.

Accuracy of infrared thermography for perforator mapping: A systematic review and meta-analysis of diagnostic studies

INTRODUCTION

Infrared thermography allows the detection of infrared radiation which can be reliably associated with skin temperature. Modern portable thermography devices have been used to identify the location of skin perforators by detecting subtle differences in skin temperature. The aim of this study is to conduct a diagnostic accuracy systematic review to determine the specificity and sensitivity of infrared thermography.

MATERIALS AND METHODS

A PRISMA-compliant systematic review and meta-analysis was conducted, scrutinising PUBMED and EMBASE databases for diagnostic studies measuring the accuracy of infrared thermography for perforator identification. Article screening, review and data gathering was conducted in parallel by two independent authors. Eligible studies were subject to a formal risk of bias was assessment using the QUADAS2 instrument.

RESULTS

A total of 254 entries were obtained, of which 7 satisfied our pre-established inclusion criteria. These studies reported a total of 435 perforators in 133 individuals. The most commonly investigated locations were the antero-lateral thigh and abdominal wall. Reported sensitivity values ranged from 73.7% to 100%. A meta-analysis demonstrated a cumulative sensitivity of 95%. Specificity was not routinely reported. All studies presented a moderate to high risk of bias according to QUADAS2.

DISCUSSION

Affordable infrared thermography devices are an interesting alternative to traditional preoperative investigations for perforator mapping. They are sensitive enough to reliably identify a large proportion of perforators as "hot-spots". However, there is limited evidence to estimate the specificity of this technology, as studies have failed to report true negative values associated with "cold-spots".

Abdominal Cutaneous Thermography and Perfusion Mapping after Caesarean Section: A Scoping Review

Introduction: Caesarean section (CS) is the most prevalent surgical procedure in women. The incidence of surgical site infection (SSI) after CS remains high but recent observations of CS wounds using infrared thermography has shown promise for the technique in SSI prognosis. Although thermography is recognised as a 'surrogate' of skin perfusion, little is known of the relationship between skin temperature and skin perfusion in the context of wound healing. Aim: To assess the extent of literature regarding the application of infrared thermography and mapping of abdominal cutaneous perfusion after CS. Methods: Wide eligibility criteria were used to capture all relevant studies of any design, published in English, and addressing thermal imaging or skin perfusion mapping of the abdominal wall. The CINAHL and MEDLINE databases were searched, with two independent reviewers screening the title and abstracts of all identified citations, followed by full-text screening of relevant studies. Data extraction from included studies was undertaken using a pre-specified data extraction chart. Data were tabulated and synthesised in narrative format. Results: From 83 citations identified, 18 studies were considered relevant. With three additional studies identified from the reference lists, 21 studies were screened via full text. None of the studies reported thermal imaging and cutaneous perfusion patterns of the anterior abdominal wall. However, two observational studies partially met the inclusion criteria. The first explored analysis methodologies to 'interrogate' the abdominal thermal map. A specific thermal signature ('cold spots') was identified as an early 'flag' for SSI risk. A second study, by the same authors, focusing on obesity (a known risk factor for SSI after CS) showed that a 1 °C lower abdominal skin temperature led to a 3-fold odds of SSI. Conclusion: There is a significant gap in knowledge on how to forewarn of wound complications after CS. By utilising the known association between skin temperature and blood flow, thermographic assessment of the wound and adjacent thermal territories has potential as a non-invasive, independent, imaging option with which to identify tissue 'at risk'. By identifying skin 'hot' or 'cold' spots, commensurate with high or low blood flow regions, there is potential to shed light on the underlying mechanisms leading to infective and non-infective wound complications.

Smartphone Thermal Imaging Can Enable the Safer Use of Propeller Flaps

The use of thermography for the identification of cutaneous "hot spots" that coincide with perforators is not a new concept, but the required professional cameras may be prohibitively expensive. Only relatively recently, incredibly cheap but adequate thermal imaging cameras have become available that work in concert with the ubiquitous cell phone. This can now serve as a rapid, accurate, and complementary method for finding a perforator sufficient to serve as the hub for a perforator pedicled propeller flap. In addition, the preferred direction of rotation about that hub, effect of flap insetting on perfusion, and then postoperative monitoring are possible by proper interpretation of corresponding thermograms. Every reconstructive surgeon should be able to obtain this device, and then easily learn what potential attributes for them are available when planning a propeller flap.

Smartphone Thermography for Lower Extremity Local Flap Perforator Mapping

BACKGROUND

 The versatile application of local perforator flaps for coverage throughout the lower extremity has already been well proven. Often a "free-style" approach has been used to design these flaps, as conventional imaging devices for perforator identification may be too expensive or unavailable. The recent adaptation of Smartphone thermal digital imaging may now prove to be a cheaper and more readily available means for identifying the requisite perforators that will sustain these local flaps.

METHODS

 Over the past year, a prospective study was undertaken of all patients having a local perforator flap for coverage of a lower extremity defect. Twenty-eight local perforator flaps involving all subtypes were utilized in 25 patients. Smartphone thermography was used in all patients preoperatively to identify preferable perforator or vascular network "hot spots" that allowed appropriate flap design. Intraoperative and postoperative monitoring was similarly done for all flaps to determine outcomes.

RESULTS

 All local perforator flaps were based on perforators identified using smartphone thermography. All flaps (23 or 82.1%) that the thermal digital image predicted 100% viability totally survived. Five flaps were predicted to have marginal viability, but two nevertheless survived completely while the others required only minor readjustments. Peninsular and keystone variety perforator flaps were those most commonly used.Thermography always facilitated making the correct decision as to whether a proximal- or distal-based peninsular flap would be superior. Subfascial elevation of cool spots in keystone flaps were found to be least likely to interfere with flap perfusion.

CONCLUSION

 Smartphone thermography is an inexpensive and expeditious means for identification of "hot spots" that is always used by us to ensure perfusion to lower extremity perforator local flaps. This is a complementary technique for their safer design, harvest, and subsequent monitoring in conjunction with more complex screening tools as indicated.

Dynamic infrared thermography (DIRT) in Deep Inferior Epigastric Perforator (DIEP) flap breast reconstruction: standardization of the measurement set-up

Breast reconstruction with an autologous free Deep Inferior Epigastric Perforator (DIEP) flap is one of the preferred options following mastectomy. A challenging step in this procedure is the selection of a suitable perforator that provides sufficient blood supply for the flap. The current golden standard for perforator mapping is computed tomography angiography (CTA). However, this is a relatively expensive imaging modality that requires intravenous contrast injection and exposes patients to ionizing radiation. More recently, dynamic infrared thermography (DIRT) has been proposed as an alternative imaging modality for perforator identification. DIRT appears to be an ideal alternative technique not only for the identification of the dominant perforators, but also for the mapping of the individual influence of each perforator on the flap perfusion. Multiple studies have been performed with the use of DIRT, unfortunately without standardisation of the measurement set-up. In this technical note we propose a standardised and reproducible measurement set-up for the use of DIRT during breast reconstructions with a free DIEP flap. This set-up can be used pre-, intra- and postoperatively. A standardised measurement set-up will improve the quality of measured data and ensure reproducibility.

Dynamic InfraRed Thermography (DIRT) in DIEP-flap breast reconstruction: A review of the literature

In the industrialised world still 34% of the breast cancer patients are surgically treated by a mastectomy. Breast cancer patients in general have a good prognosis and a long-term survival. Therefore, it is important that the treatment doesn't focus only on survival but also on the quality of life. Breast reconstruction improves the quality of life. A breast reconstruction with an autologous free DIEP (Deep Inferior Epigastric artery Perforator) flap is one of the preferred options after mastectomy. A challenging step in this procedure is the selection of a suitable perforator that provides sufficient blood supply for the flap. Current techniques to locate the perforator vessels include handheld Doppler, colour Doppler ultrasound (CDU), Magnetic resonance angiography (MRA), computer tomographic angiography (CTA) and dynamic infrared thermography (DIRT). At present CTA is the golden standard and DIRT a new option. The objective of this article is to document whether DIRT can accurately map the position of the perforators and measure their influence on the perfusion of the flap in order to select the best perforators to improve the outcome of breast reconstructions with free DIEP flaps. A systematic review of the literature published between January 1998 and November 23th 2018 was conducted regarding the possible benefit of dynamic infrared thermography (DIRT) in DIEP-flap breast reconstructions. The databases PubMed and Web of Science were used to search for qualified articles. Inclusion criteria were women who underwent a breast reconstruction by means of a DIEP flap where DIRT was used to analyse the blood supply of the flap. The search yielded a total of fourteen suitable articles: six articles being descriptive clinical studies, three case reports, three expert opinions/Overview articles and two systematic reviews. There are only a limited number of studies looking at the use of DIRT in breast reconstruction with DIEP-flaps. Adequate identification of the dominate vessel(s) in DIEP reconstruction is essential for a successful outcome. DIRT appears to be an ideal alternative technique for the identification of the dominant perforators of the flap. With the use of DIRT it is possible to identify the dominant vessel(s) preoperatively. The use of DIRT during the operation allows the tailoring of the surgery and postoperative use may identify vascularisation problems in an early stage. Additional high-quality studies are needed, but DIRT seems to be a valuable investigation for the pre-, per- and postoperative phase of DIEP-flap reconstructions.

Acupuncture Points and Perforating Cutaneous Vessels Identified Using Infrared Thermography: A Cross-Sectional Pilot Study

Aims

To evaluate the presence of perforating cutaneous vessels (PCV) in different lower limb acupuncture points (AP) using thermography.

Material and Methods

An analytical cross-sectional study was performed on the two lower limbs (n=6) of volunteer subjects. In total, 144 AP and 144 control points (CP) were analysed, one for each AP. First, the AP and CP were located on each individual. Subsequently, both the real and thermographic images were created. In the real images, the location of the AP and the established CP were highlighted with boxes. FLIR Tools Plus and Physio Thermal Imaging software were used to merge the real image with the AP and the CP and to merge the thermographic image with the PCV. By superimposing both images, we were able to verify the presence of PCV among the AP and CP.

Results

PCV were identified in 87.5% of the 144 AP examined and in 18.1% of the respective CP. All the AP had a higher percentage of PCV compared to their respective CP, with statistically significant differences in all points, except for ST33 and ST34. The probability of finding PCV in AP was 11 times higher than the probability of not finding it.

Discussion

Thermography may serve as a useful tool in the assessment and treatment of patients using acupuncture. The presence of PCV in the area of the acupuncture needle insertion could partially influence the effects generated by the acupuncture technique from the vascular autonomic point of view.

Conclusions

There is a high proportion of PCV in the AP area located in the lower limb.

The use of thermography to design tissue flaps - experimental studies on animals

Introduction

Methods allowing one to locate the position of a cutaneous perforator do not allow one to determine the boundaries of the vascularized skin. In clinical practice this causes complications in the form of marginal necrosis of the flap.

Aim

To examine the usefulness of thermography to assess the extent of vascularization of the skin and subcutaneous tissue by a single perforator.

Material and methods

Thirty-one male rats were used. Using dynamic thermography the perforators on the abdominal skin were located. Afterwards the flap was prepared on a randomly chosen perforator. After 24 h the extent of vascularization of the skin by a single perforator was examined.

Results

In 22.5% of cases the number of perforators marked in the thermography was equal to the number of perforators marked intraoperatively, in 64.5% it was lower and in 13% higher. The use of thermography has shown that basing the flap vascularization on the perforator with low efficiency resulted in statistically more frequent occurrence of ischemia and partial necrosis of the flap (p = 0.024). Partial necrosis of the flap occurred in 12 of 31 cases, always in the area in which during the preoperative thermography no perforators were found. The areas of necrosis occurred irrespectively of the distance from the supplying vessel.

Conclusions

When designing the shape of the flap, the distribution of all perforators must be considered. The perforators need to be included in the area of prepared tissues because their location indicates the area with a more efficient network of vessels.