An overview of methods for vascular mapping in the planning of free flaps

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.

Pain relief effect of angiopuncture therapy on patients with postoperative pain: A clinical trial

BACKGROUND

The objective of this study is to study the pain relief effects of angiopuncture therapy in patients with postoperative pain.

METHODS

Forty-one patients were randomly selected based on the inclusion and exclusion criteria. Doppler imaging was performed to locate the cutaneous perforator. Angiopuncture was performed on the first postoperative day. A Numerical Rating Scale was used to evaluate the degree of pain before and after angiopuncture. Utilizing the paired t test or Wilcoxon signed rank test, all pre- and post-data were examined, and further subgroup analysis based on time was performed.

RESULTS

Variance analysis revealed a significant difference before and after angiopuncture (P < .05). The results of the subgroup analysis showed the pain-relieving effect of angiopuncture for postoperative pain patients at the time points of 6 hours, 12 hours, 24 hours, 48 hours, and 72 hours was apparent (P < .05).

CONCLUSION

The angiopuncture therapy approach may assist in pain relief in patients with postoperative pain.

Variability of anterolateral thigh flap perforator locations - clinical implications

<b><br>Introduction:</b> The anterolateral thigh flap is an example of a free flap widely applied for reconstruction of tissues within various areas of the body.</br> <b><br>Aim:</b> The aim of the study was to determine the most common locations of the ALT flap perforators in men and women as well as to clarify any potential differences in the location of the vessel in male vs. female subjects.</br> <b><br>Material and method:</b> In years 2021-2022, a study was conducted at the Plastic, Reconstructive, and Aesthetic Surgery Clinic in a group of 90 volunteers (45 women and 45 men, a total of 180 lower extremities) to determine the location of the anterolateral thigh flap perforator against the flap surface using a portable Doppler probe.</br> <b><br>Results:</b> Variable locations were revealed for the anterolateral thigh flap perforator within the study. In women, the perforator is located more distally from the anterior superior iliac spine, most frequently within the inferolateral quadrant, while being located closer to the anterior superior iliac spine, and most frequently within the superolateral quadrant, in men. No perforator was found in 3.3% of the examined limbs. No statistically significant differences were observed between the course of the perforators within the left and right lower limbs in individual patients.</br> <b><br>Conclusions:</b> The location of the ALT flap perforator is subject to sexual dimorphism, which facilitates the investigation area being narrowed down to the well-defined locations of its most frequent occurrence when planning anterolateral thigh flap reconstructive procedures.</br>.

Preoperative planning using virtual reality and computed tomography angiogram in deep inferior epigastric perforator flap breast reconstruction

The gold standard for preoperative planning of deep inferior epigastric perforator (DIEP) flap breast reconstruction uses computed tomography angiography (CTA). Virtual reality (VR) circumnavigates the limitations of CTA by reconstructing a fully immersive and interactive 3D representation of the scan. Scans of 44 patients who underwent DIEP flap breast reconstruction were retrospectively reviewed and compared using CTA and VR imaging modalities. The objective of this research was to compare perforators found using VR to the ones identified using conventional CTA. A correlation was found between the imaging modalities for unilateral (R = 0.96 (CI = 0.92, 0.98)) and bilateral (R = 0.93, (CI = 0.83, 0.97)) DIEP flap surgeries when comparing perforator location related to the umbilicus. Multivariable ordinal logistic regression found that higher intramuscular course length (IMC) is associated with the number of perforators found per side (OR = 1.79 (CI = 1.24, 2.6)), and medial location (OR = 2.85 (CI = 1.38, 5.87)). Larger vessel caliber (VC) is associated with shorter IMC (T2 vs. T3, OR = 3.34 (CI = 1.49, 7.49)), and branching in adipose tissue (AB) is associated with higher VC (T1 vs. T3, OR = 0.02 (CI = 0.007, 0.08); T2 vs. T3, OR = 0.24 (CI = 0.11, 0.55)). Overall, preoperative planning using VR was easy to use, safe, more intuitive, and provided in a time-efficient manner, more information about perforant characteristics. VR can improve the surgeon's decision accuracy, relating to the best perforators for harvesting, in a shorter time period.

Extremity reconstruction with superficial circumflex iliac artery perforator free flap: Refinements and innovations after 101 cases

INTRODUCTION

The superficial circumflex iliac artery perforator flap is based on perforators originated on the superficial circumflex iliac artery. This flap is thin and pliable, of moderate size, and has a concealed donor site. The authors report their experience, innovations, and refinements in both planning and execution, and the outcomes obtained after 101 extremity reconstruction consecutive cases.

PATIENTS AND METHODS

A total of 101 superficial circumflex iliac artery perforator flaps were prospectively reviewed and followed up for at least one year at Hospital del Trabajador. The flaps were used for both upper (n = 21) and lower limbs (n = 80), planned with computed tomography angiography/augmented reality, and raised above the superficial fascia using a standardized approach. Demographic data, anatomy of the flap, surgical technique, and the results were assessed.

RESULTS

Average flap size was 90.5 cm2, ranging from 25 to 212 cm2. Total flap loss occurred in 6 flaps (5.9%). Four patients developed complications at the donor site. Debulking surgery was performed in 7 patients (6.9%). The average follow-up period was 850 days (range, 370-1405 days).

CONCLUSIONS

The superficial circumflex iliac artery perforator flap is versatile, thin, and pliable, suitable for covering even large defects in either the upper or lower extremities, obtaining a shallow contour and optimal esthetics results. The elevation can be standardized, but requires training and proper planning. This is the largest series in a Western country reporting the experience, refinements, and innovation that allows for better results in limb reconstruction.

Accuracy analysis of traditional acupoint location and the coincidence of cutaneous arterial perforators and acupoints

Several reports have shown a coincidence relationship between perforators and acupoints. However, there have been few previous reports of objective experimental methods to verify the reliability of the accuracy of acupoint location (APL) with nearby perforators. This research aimed to determine the internal agreement of the APL of five acupuncturists and to analyze the coincidence rate of acupoints with nearby perforators. Three two healthy volunteers were recruited with the inclusion and exclusion criteria. Three TCM clinical physicians determined acupoints in areas of the lower limb of participants. Two microsurgeons sketched corresponding regions based on the most common skin flap operation sites, located bone markers, and drew the skin flap axis. Doppler ultrasound was used to mark the perforator point and the distances measured for both points. There is no significant difference in the distance between the acupoints and perforators localization in different groups, and there are significant differences between the angle formed by acupoints and penetrators in all groups. All the points located by the traditional Chinese medicine (TCM) therapists are distributed around the dot. The distance between the coordinate point (A-B) of Wēnliū (LI7) localization is the largest, reaching 16.6 mm. The accuracy of the acupoint location of each physician is limited by the clinical experience of physicians, and the difference among them is significant. There is a certain correspondence between the location of acupoints and perforators, which needs further studies to confirm.

Value of the combination of a smartphone-compatible infrared camera and a hand-held doppler ultrasound in preoperative localization of perforators in flaps

This study was conducted to evaluate the effectiveness of the FLIR ONE PRO, a thermal imaging camera for smartphones, combined with handheld Doppler (HHD) in the localization of perforator arteries and to assess the efficacy of the FLIR ONE PRO in distinguishing perforators of the descending branch of the lateral circumflex femoral artery (LCFA) from other perforators of the anterolateral thigh perforator (ALTP) flap. We enrolled 29 free perforator flaps from 22 patients in our study. Before surgery, dynamic infrared thermography was performed using a FLIR ONE PRO to visualize hotspots on the flaps. Subsequently, HHD was used to further determine the perforators under the hotspots, which were ultimately identified and confirmed through intraoperative findings. Additionally, infrared images of the ALTP flap were analyzed using FLIR Tools. The performances of the FLIR ONE PRO and FLIR ONE PRO + HHD groups were evaluated by comparing the intraoperative findings. Using FLIR ONE PRO + HHD, 119 hotspots and 106 perforators were identified during surgery. Using FLIR ONE PRO + HHD, sensitivity and positive predictive value were 97.87% and 88.46%, respectively, in the young (age≤45 years). In the elderly group (age>45 years), these percentages were 93.22% and 82.09%, respectively. In addition, we found that the FLIR ONE PRO could be useful for differentiating perforators in the descending branch of the LCFA from other perforators within 5 min. The results showed a sensitivity of 96.15%, a specificity of 98.9%, a positive predictive value of 96.15%, and a negative predictive value of 98.9%. Compared to using FLIR ONE PRO alone, the combined application of HHD and FLIR ONE PRO had a higher value in perforator localization by increasing the positive predictive value. The FLIR ONE PRO may have significance in the rapid prediction of perforators deriving from the descending branch of the LCFA.

Augmented reality-assisted systematic mapping of anterolateral thigh perforators

PURPOSE

In soft tissue reconstructive surgery, perforator localization and flap harvesting have always been critical challenges, but augmented reality (AR) has become a dominant technology to help map perforators.

METHODS

The lateral circumflex femoral artery (LCFA) and its perforators were reconstructed by CTA in consecutive patients (N = 14). Then, the anterolateral thigh perforators and the points from which the perforators emerged from the deep fascia were marked and projected onto the skin surface. As the virtual images were projected onto patients according to bony markers, the courses of the LCFA and its perforators were depicted on the skin surface for intraoperative guidance. Finally, the locations of the emergence points were verified by intraoperative findings and compared to those determined by handheld Doppler ultrasound.

RESULTS

The sources, locations, and numbers of perforators were determined by CTA. The perforators and their emergence points were accurately mapped on the skin surface by a portable projector to harvest the anterolateral thigh perforator flap. During the operation, the accuracy of the CTA & AR method was 90.2% (37/41), and the sensitivity reached 97.4% (37/38), which were much higher than the corresponding values of Doppler ultrasound. Additionally, the differences between the AR-marked points and the intraoperative findings were much smaller than those seen with Doppler ultrasound (P < 0.001). Consequently, all of the flaps were well designed and survived, and only one complication occurred.

CONCLUSION

Augmented reality, namely, CTA combined with projection in this study, plays a vital and reliable role in locating the perforator emergence points and guiding the procedure to harvest flaps and has fewer potential risks.

Computed tomography angiography-aided individualized anterolateral thigh flap design in the reconstruction of oral and maxillofacial soft tissue defects

PURPOSE

To evaluate a novel method and computed tomography angiography (CTA) for locating anterolateral thigh flap (ALTF) perforators to design individualized ALTFs to reconstruct maxillofacial soft tissue defects.

STUDY DESIGN

This study comprised a group of 36 patients (CTA group) with malignant oral and maxillofacial tumors who underwent CTA and who received individualized ALTFs and a group of 28 patients (control group) with the same condition but without preoperative CTA examination and with nonindividualized ALTFs. ALTFs in the CTA group were designed and harvested using the locating device and CTA, whereas ALTFs in the control group were designed and harvested according to each surgeon's experience.

RESULTS

Fifty perforators were located and 36 ALTFs harvested in the CTA group. In the control group, 34 perforators were located and 28 ALTFs harvested. Less time was required to locate the perforators in the CTA group. Moreover, the CTA group had a higher flap survival rate and better patient satisfaction regarding the postoperative aesthetics and phonetic and swallowing functions.

CONCLUSIONS

The results suggest that CTA and the locating device can be used to accurately locate ALTF perforators and that this method aids in the design and harvesting of individualized ALTFs to achieve good functional and aesthetic outcomes.

Importance of Incidental Findings in Preoperative Computed Tomography Angiography for Abdominal-Based Free Flap Breast Reconstruction: A Multi-institutional Study

BACKGROUND

Besides its intended purpose of perforator mapping, CTA can also identify incidental findings that may require further evaluation. In this multi-institutional study, we evaluated the frequency of incidental findings and their significance and impact on treatment course. We also aimed to identify risk factors for detecting such findings.

METHOD

A retrospective review of patients who underwent perforator mapping with CTA was performed over a 5-year period from three academic institutions. Relevant sociodemographic and clinicopathologic information were reviewed, as well as CTA reports and follow up visits and treatment outcomes. Univariate and multivariate analyses were performed to assess the relationship between risk factors and incidental findings.

RESULTS

From January 2015 to July 2020, a total of 656 patients were identified that met inclusion criteria. Overall, 342 incidental findings were found, out of which 76 required additional imaging or consultation. Ultimately, 10 (1.5%) patients had findings that altered reconstructive management, including 5 (0.8%) patients having severe disease that cancelled their reconstruction altogether. Advanced age and immediate reconstruction timing were independent risk factors for incidental findings.

CONCLUSION

Incidental findings can be commonly identified on preoperative CTA for DIEP flap breast reconstruction. Suspicious findings should be investigated thoroughly as they can alter the reconstructive course. Understanding of high-risk groups for incidental findings can further advance patient education during initial consultation.

Initial Investigation of Clinical Value of Noise-Optimized Virtual Monoenergetic Images Derived From Dual-Energy Computed Tomography Angiography in Preoperative Perforator Planning of Anterolateral Thigh Flap Transplantation

OBJECTIVE

To objectively and subjectively assess the image characteristics of noise-optimized virtual monoenergetic images [MEI (+)] and polyenergetic images (PEIs) from dual-energy computed tomography angiography and then to explore the clinical value of the optimal MEI (+) in preoperative perforator planning of anterolateral thigh (ALT) flap transplantation.

METHODS

Sixteen patients (32 thighs) who underwent lower extremity run-off dual-energy computed tomography angiography for planning ALT flap transplantation were enrolled. One standard PEI and 5 MEI (+) in 10-keV intervals (range, 40-80 keV) were reconstructed. First, we compared the image quality subjectively (branch order, image quality, and vascular network continuity) and objectively (vascular attenuation, image noise, signal-to-noise ratio, and the contrast-to-noise ratio). Then, we compared the clinical value (number, type, source artery, pedicle length, caliber, and location of all sizable perforators) between the optimal MEI (+) and PEI groups.

RESULTS

The 40-keV MEI (+) was rated superior subjective and objective image quality metrics to PEI (all P < 0.001). Compared with PEI, 40 keV MEI (+) increased the number of visible perforators, the percentage of perforators with identifiable types, and the measurable length of perforator pedicle (all P < 0.001).

CONCLUSIONS

We recommend 40 keV MEI (+) for the visualization of perforators and their contribution to the selection and location of suitable perforators in preoperative planning for ALT flaps.

Superficial Circumflex Iliac Artery Perforator Flap in Advanced Head and Neck Reconstruction: From Simple to Its Chimeric Patterns and Clinical Experience with 22 Cases

BACKGROUND

Head and neck tissue defects after ablative head and neck surgery often require complex and composite reconstructions. The superficial circumflex iliac artery perforator (SCIP) flap is an extremely versatile perforator-based flap with minimal donor-site morbidity. The authors present their experience with both simple and chimeric SCIP flap reconstructions for complex defects in various head and neck regions.

METHODS

Twenty-two patients undergoing ablative head and neck surgery for oncologic abnormalities were treated by means of a SCIP flap reconstruction. Patients' mean age was 62 years; 21 were men and one was a woman. Seventeen flaps were simple and five were chimeric reconstruction patterns. Indocyanine green perfusion imaging was performed in all cases.

RESULTS

Twenty-one of 22 patients (95.5 percent) were successfully treated with good aesthetic and functional results. Two patients (9 percent) showed minor donor-site complications that were managed conservatively. The mean follow-up period was 5.3 months (range, 2 to 8 months).

CONCLUSIONS

This case series demonstrates the reliability and versatility of the SCIP flap for head and neck reconstruction. The chimeric options combined with bone, double-skin paddle, and muscle offer a broad variety of functional reconstructive solutions for complex head and neck surgery. Intraoperative indocyanine green perfusion examinations area valuable tool to assess and ascertain proper inset, vitality, and postanastomosis vessel patency in these complex microvascular flap reconstructions.

CLINICAL QUESTION/LEVEL OF EVIDENCE

Therapeutic, IV.

Preoperative Computed Tomography Angiography for ALT Flaps Optimizes Design and Reduces Operative Time

BACKGROUND

 Computed tomography angiography (CTA) has been widely used for perforator mapping in abdominal-based reconstruction, but it is less widespread in the anterolateral thigh (ALT) flap. However, CTA may be quite useful for ALT planning, as this flap has demonstrated substantial variability in intrapatient bilateral vascular anatomy. This study investigated whether standard use of preoperative CTA resulted in selection of the donor extremity with preferential perforator anatomy, and whether this affected operative time and postoperative outcomes.

METHODS

 A retrospective review of 105 patients who underwent proposed ALT flap reconstruction was performed. Seventy-nine patients received bilateral lower extremity CTAs, which were evaluated for dominant perforator anatomy (septocutaneous, musculoseptocutaneous, or musculocutaneous). Donor extremity selection was noted, and predicted perforator anatomy was compared with that encountered intraoperatively.

RESULTS

 Among the 73 patients who received bilateral imaging and ultimately received an ALT, congruent findings between imaging and surgical exploration were observed in 51 (69.8%) patients. Thirty (37.9%) patients had asymmetric perforator anatomy between their bilateral extremities on imaging. Among these, the leg with optimal perforator anatomy was selected in 70% of cases. There were no significant reductions among postoperative complication rates, but selection of the donor site with preferential anatomy was associated with a decrease in operative time (p = 0.049) among patients undergoing extremity reconstruction.

CONCLUSION

 CTA is a useful tool for optimizing donor site selection for ALT flaps and reducing operative time. We believe that standard use of preoperative CTA in ALTs warrants further consideration.

Comparison of Various Modalities Utilized for Preoperative Planning in Microsurgical Reconstructive Surgery

BACKGROUND

 The benefits of preoperative perforator imaging for microsurgical reconstruction have been well established in the literature.

METHODS

 An extensive literature review was performed to determine the most commonly used modalities, and their applicability, advantages and disadvantages.

RESULTS

 The review demonstrated varioius findings including decreases in operative time and cost with the use of CT angiography to identification of perforators for inclusion in flap design with hand-held Doppler ultrasound. Modalities like MR angiography offer alternatives for patients with contrast allergies or renal dysfunction while maintaining a high level of clarity and fidelity. Although the use of conventional angiography has decreased due to the availability of less invasive alternatives, it continues to serve a role in the preoperative evaluation of patients for lower extremity reconstruction. Duplex ultrasonography has been of great interest recently as an inexpensive, risk free, and extraordinarily accurate diagnostic tool. Emerging technologies such as indocyanine green fluorescence angiography and dynamic infrared thermography provide real-time information about tissue vascularity and perfusion without requiring radiation exposure.

CONCLUSION

 This article presents an in-depth review of the various imaging modalities available to reconstructive surgeons and includes hand held Doppler ultrasound, CT angiography, MR angiography, conventional angiography, duplex ultrasonography, Indocyanine Green Fluorescence Angiography and Dynamic Infrared Thermography.

Anterolateral Thigh Flap Design by Using Suprafascial Course of the Perforator

OBJECTIVES

Recently, anterolateral thigh flap has become one of the most commonly used free flaps in reconstructive surgery. Although its pedicle has relatively sufficient length, it falls short in some circumstances. Eccentric perforator location can be used to lengthen the pedicle, but flap tip viability can be a problem in this case. In addition, partial flap loss can be encountered in perforator flaps. The aim of this study was the use of multidetector computed tomographic angiography in preoperative mapping to overcome these problems.

MATERIALS AND METHODS

Anterolateral thigh perforator flap was planned for various soft-tissue reconstructions in 19 patients. There were 15 males and 4 female patients with ages ranging from 19 to 65 years. These patients were evaluated with preoperative multidetector computed tomographic angiography to choose and to trace the course of the perforators. Flaps were designed according to the suprafascial course of the perforators. Perforators were safely located eccentrically when needed. Pedicle length and complications, such as infection, wound dehiscence, and partial or total flap loss, were recorded.

RESULTS

Perforators were located eccentrically in 8 patients and centrally in the other 11 patients. Eleven flaps were used in lower leg reconstruction, 2 flaps in popliteal region, and 6 flaps in head and neck. All flaps survived and any partial or total loss did not occur. There was not any infection and wound problem.

CONCLUSIONS

Multidetector computed tomographic angiography can reveal the suprafascial course of the perforator and help design anterolateral thigh perforator flap. By using this kind of mapping, perforators can be safely located eccentrically to lengthen the pedicle and partial flap loss can be prevented.

Stratification of Surgical Risk in DIEP Breast Reconstruction Based on Classification of Obesity

BACKGROUND

 From both a medical and surgical perspective, obese breast cancer patients are considered to possess higher risk when undergoing autologous breast reconstruction relative to nonobese patients. However, few studies have evaluated the continuum of risk across the full range of obesity. This study sought to compare surgical risk between the three World Health Organization (WHO) classes of obesity in patients undergoing deep inferior epigastric perforator (DIEP) flap breast reconstruction.

METHODS

 A retrospective review of 219 obese patients receiving 306 individual DIEP flaps was performed. Subjects were stratified into WHO obesity classes I (body mass index [BMI]: 30-34), II (BMI: 35-39), and III (BMI: ≥ 40) and assessed for risk factors and postoperative donor and recipient site complications.

RESULTS

 When examined together, the rate of any complication between the three groups only trended toward significance (p = 0.07), and there were no significant differences among rates of specific individual complications. However, logistic regression analysis showed that class III obesity was an independent risk factor for both flap (odds ratio [OR]: 1.71, 95% confidence interval [CI]: 0.91-3.20, p = 0.03) and donor site (OR: 2.34, 95% CI: 1.09-5.05, p = 0.03) complications.

CONCLUSION

 DIEP breast reconstruction in the obese patient is more complex for both the patient and the surgeon. Although not a contraindication to undergoing surgery, obese patients should be diligently counseled regarding potential complications and undergo preoperative optimization of health parameters. Morbidly obese (class III) patients should be approached with additional caution, and perhaps even delay major reconstruction until specific BMI goals are met.

ZNF667 attenuates leukocyte-endothelial adhesion via downregulation of P-selectin in skin flap following remote limb ischemic preconditioning

We assessed the effects and potential mechanism of romote ischemic preconditioning (RIPC) on leukocytes-endothelium cell adhesion in the flap microvessel after ischemia-reperfusion (I/R) injury. Eight hours after reperfusion, edema and intravascular leukocyte aggregation were reduced and microvessels were more obvious in the group with superficial inferior epigastric artery (SIEA) perforator flap (SIEA-flap) subjected to RIPC than in the I/R group. Zinc finger protein 667 (ZNF667) was significantly increased but P-selectin was decreased in the flaps subjected to RIPC, compared to those in the I/R group. The low expression of P-selectin was associated with ZNF667 expression and activation in human dermal microvascular endothelial cells in response to hypoxic preconditioning. ZNF667 bound to the P-selectin promoter region, suppressing its transcription through a special core sequence. The ablation of P-selectin by small interfering RNA effectively prevented the leukocytes-endothelium cell adhesion effect of ZNF667-knockdown. ZNF667 upregulation attenuates leukocyte-endothelial cell adhesion by negatively regulating the expression of P-selectin in SIEA-flap subjected to RIPC.

Noncontrast Magnetic Resonance Imaging of Perforators for Preoperative Evaluation of Anterolateral Thigh Flaps

The anterolateral thigh (ALT) flap is a commonly utilized perforator-based flap in reconstructive surgery. Although previous studies have used various angiographic techniques to preoperatively image ALT perforators, none have investigated the efficacy of noncontrast magnetic resonance imaging (MRI). Our study investigates the efficacy of our institutional fat suppression noncontrast MRI sequence to characterize the number, location, and course of dominant skin perforators in the ALT for preoperative planning.

The utility of three-dimensional models in complex microsurgical reconstruction

BACKGROUND

Three-dimensional (3D) model printing improves visualization of anatomical structures in space compared to two-dimensional (2D) data and creates an exact model of the surgical site that can be used for reference during surgery. There is limited evidence on the effects of using 3D models in microsurgical reconstruction on improving clinical outcomes.

METHODS

A retrospective review of patients undergoing reconstructive breast microsurgery procedures from 2017 to 2019 who received computed tomography angiography (CTA) scans only or with 3D models for preoperative surgical planning were performed. Preoperative decision-making to undergo a deep inferior epigastric perforator (DIEP) versus muscle-sparing transverse rectus abdominis myocutaneous (MS-TRAM) flap, as well as whether the decision changed during flap harvest and postoperative complications were tracked based on the preoperative imaging used. In addition, we describe three example cases showing direct application of 3D mold as an accurate model to guide intraoperative dissection in complex microsurgical reconstruction.

RESULTS

Fifty-eight abdominal-based breast free-flaps performed using conventional CTA were compared with a matched cohort of 58 breast free-flaps performed with 3D model print. There was no flap loss in either group. There was a significant reduction in flap harvest time with use of 3D model (CTA vs. 3D, 117.7±14.2 minutes vs. 109.8±11.6 minutes; P=0.001). In addition, there was no change in preoperative decision on type of flap harvested in all cases in 3D print group (0%), compared with 24.1% change in conventional CTA group.

CONCLUSIONS

Use of 3D print model improves accuracy of preoperative planning and reduces flap harvest time with similar postoperative complications in complex microsurgical reconstruction.

How to Design and Harvest a Propeller Flap

Propeller flaps are local flaps based either on a subcutaneous pedicle, a single perforator, or vessels entering the flap in such a way so as to allow the flap to rotate on their axis. Depending on the kind of pedicle and the anatomical area, the preoperative investigation and the harvesting techniques may vary. An adequate knowledge of skin and subcutaneous tissue perfusion in the different areas of the body is very important to plan a propeller flap to be successful. The surgeon should begin by finding the most suitable perforators in the area surrounding the defect using available technology. The position, size, and shape of the flap are planned about this point. For perforator-pedicled propeller flaps, the procedure starts with an exploration from the margins of the defect or through a dedicated incision to visualize any perforators in the surroundings. The most suitable perforator is selected and isolated, the skin island is replanned, and the flap is harvested and rotated into the defect. The variations in surgical technique for other types of propellers and in specific anatomical areas are also described. Compared with free flaps, propeller flaps have the advantage of a simpler, shorter operation, without the need for a recipient vessel for microanastomosis. Yet, from a technical point of view, an adequate experience in dissecting perforators and the use of magnifying glasses are almost always required.

Preoperative Vascular Planning of Free Flaps: Comparative Study of Computed Tomographic Angiography, Color Doppler Ultrasonography, and Hand-Held Doppler

BACKGROUND

Preoperative planning of microsurgical perforator free flaps continues to be a discussion topic among microsurgeons. The purpose of this study was to compare the ability of three methods of preoperative vascular mapping-hand-held Doppler imaging, color Doppler ultrasonography, and computed tomographic angiography-to detect perforators and their concordance with surgical findings.

METHODS

A prospective study was performed to evaluate the sensitivity, specificity, and accuracy of hand-held Doppler imaging, color Doppler ultrasonography, and computed tomographic angiography to detect free flap perforators. Each patient undergoing a free flap reconstruction was studied preoperatively with the three methods, and the results were compared to the intraoperative findings.

RESULTS

Fifty-three patients undergoing autologous tissue reconstruction were included. Most reconstructions (71.7 percent) were performed with anterolateral thigh flaps. The positive predictive value (color Doppler ultrasonography, 100 percent; computed tomographic angiography, 100 percent; hand-held Doppler imaging, 88.6 percent) and negative predictive value (color Doppler ultrasonography, 100 percent; computed tomographic angiography, 94.3 percent; hand-held Doppler imaging, 90.5 percent) rates were significantly different between methods. The high resolution of the color Doppler ultrasonography probe provided a direct vision of the vasculature arborization and efficiently detected vessels with diameters of less than 0.5 mm. The sensitivity, specificity, and accuracy of color Doppler ultrasonography were greater than those of both computed tomographic angiography and hand-held Doppler imaging. There was 100 percent concordance between color Doppler ultrasonography perforators and the surgical findings.

CONCLUSIONS

Color Doppler ultrasonography provides a reproducible, harmless, and accurate way to visualize vascular anatomy. It has a high correlation with the surgical findings, signifying advantages over hand-held Doppler and computed tomographic angiography in sensitivity, specificity, and accuracy.

CLINICAL QUESTION/LEVEL OF EVIDENCE

Diagnostic, II.

Perforator Variability of the Anterolateral Thigh Flap Identified on Computed Tomographic Angiography: Anatomic and Clinical Implications

BACKGROUND

 The anterolateral thigh (ALT) flap is a useful flap with minimal donor site morbidity. Preoperative computed tomographic angiography (CTA) for lower extremity reconstruction can determine vessel integrity and plan for recipient vascular targets. This study reviews lower extremity CTAs to further characterize ALT vascular anatomy and associated clinical implications thereof.

PATIENTS AND METHODS

 Lower extremity CTA studies were retrospectively reviewed, and information on ALT cutaneous perforator location, origin, and course was collected.

RESULTS

 A total of 58 lateral circumflex femoral artery (LCFA) systems in 31 patients were included. Average age was 38.8 ± 15.9 years with mean body mass index of 27.2 ± 5.7 kg/m². The majority of patients were females (23, 74.2%). The LCFA most commonly originated from the profunda femoris artery (87.3%), followed by the distal common femoral artery (9.1%). On average, there were 1.66 ± 0.69 cm perforators per extremity, with an average of 5.38 cm between adjacent perforators. Perforators originated from the descending branch of the LCFA in 89.6% of studies. Perforator caliber was <1 mm (29, 30.2%), 1 to 2 mm (55, 57.3%), or >2 mm (12, 12.5%). Mean distance from the most proximal perforator to the anterior superior iliac spine was 20.4 ± 4.82 cm. Perforators were musculocutaneous (46.9%), septocutaneous (34.4%), or septomyocutaneous (18.8%). In 58.1% of patients, only one thigh had easily dissectable septocutaneous and/or septomyocutaneous perforators, in which case preoperative CTA aided in donor thigh selection.

CONCLUSION

 ALT flap cutaneous perforator anatomy varies considerably. Using CTA, we report on rates of septocutaneous, myocutaneous, and septomyocutaneous perforators and underscore its utility in perforator selection.

Ultrasound and Plastic Surgery: Clinical Applications of the Newest Technology

BACKGROUND

Color Doppler ultrasound (CDUS) has not been routinely used in plastic and reconstructive surgery. Barriers to use have included large, cumbersome equipment, low-definition images, cost, and availability. In addition, programs in plastic surgery have not included training with ultrasound (US); thus, many current-day practitioners are unfamiliar with and reluctant to use this technology. Nevertheless, recent studies have demonstrated the utility of US in surgical planning. With the miniaturization, clearer imaging, and decreased costs of the latest US technology, previous barriers to use have largely been eliminated.

METHODS

Fifty-six patients scheduled for either reconstructive or aesthetic surgery were evaluated preoperatively and/or intraoperatively by a single surgeon with the linear 12-4 probe of a Philips Lumify CDUS device (Philips, Reedsville, Penn). For patients undergoing flap reconstruction, potential donor sites were imaged in order to locate the largest perforator. For patients undergoing abdominal procedures, intraoperative visualization of the abdominal muscular layers was used for the delivery of anesthesia during transversus abdominis plane block. Lastly, the superficial fascial system (SFS) was subjectively evaluated in all preoperative patients.

RESULTS

For flap reconstruction, 11 patients were preoperatively examined with CDUS in order to locate the largest perforators prior to perforator flap reconstruction. Flaps studied included the deep inferior epigastric perforator, anterolateral thigh, tensor fascia lata, thoracodorsal artery perforator, superior gluteal artery perforator, and the gracilis musculocutaneous. Color Doppler ultrasound findings were confirmed intraoperatively for all cases (100%). In 2 (18.2%) of 11 cases, CDUS identified perforators not detected by computed tomography angiography. Twenty-five patients undergoing either abdominoplasty or deep inferior epigastric perforator flap reconstruction had successful intraoperative visualization of the abdominal wall muscular layers, thus allowing administration of transversus abdominis plane blocks by the operating surgeon. Twenty patients undergoing body contouring surgery had preoperative visualization of the SFS. The SFS was found to be varied not only among different patients but also within individual patients.

CONCLUSIONS

The newest, miniaturized CDUS technology has a variety of applications that may improve patient outcomes and experience in plastic surgery. Our observations require further investigation to quantify the perceived benefits of this new technology.

Magnetic resonance angiography for free fibula harvest: anatomy and perforator mapping

The purpose of this study was to outline lower leg vessel anatomy and to investigate reliability and limitations of magnetic resonance angiography (MRA) in patients proposed for microvascular fibula transplantation (free fibula flap (FFF)). We retrospectively investigated MRAs of 99 patients considered for FFF. Frontal MRA planes and maximal intensity projections (MIPs) were evaluated for fibula lengths, anatomical branching pattern, arterial stenoses and fibular perforator positions in both legs (n=198). Normal branching patterns were observed in 168 (85.3%) legs. Twenty-nine (14.7%) legs presented abnormal branching patterns. Once (0.5%) the anterior, 19 times (9.6%) the posterior tibial artery were absent or hypoplastic. Nine (4.6%) lower legs presented an arteria peronea magna. Average length of the tibiofibular trunk (TFT) was 3.3±0.15cm. A total of 492 perforators were found with an average of 2.5 (±0.82±0.99) perforators per leg. A mapping of perforator run-offs was illustrated true to scale. Lower limb stenoses were distributed in the anterior tibial artery (14.1%), in the posterior tibial artery (11.1%) and in the fibular artery (8.1%). Smoking (P=0.828), diabetes (P=0.727) and peripheral arterial occlusive disease (P=0.172) did not correlate with presence of stenoses. Preoperative lower limb angiography avoids postoperative complications. MRA reliably and non-invasively identifies anatomical variants and arterial stenoses without radiation. Illustration of perforator run-offs enhances incision planning for fibula harvest.

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.

Colour Doppler sonography in the preoperative assessment of the vascular pedicle from the anterolateral thigh flap: proposal for a mathematical formula to predict pedicle length

Introduction

The anterolateral thigh flap (ALT) is one of the most commonly used grafts in head and neck reconstructive surgery. In this type of surgery, it is essential that the vascular pedicle be long enough to ensure proper vascular anastomosis. However, it is difficult to accurately estimate the pedicle length preoperatively. In this context, the current study had two aims: (1) to assess the value of colour Doppler sonography (CDS) in the preoperative assessment of the vascular pedicle and (2) to develop a mathematical model to predict the length of the vascular pedicle based on the ultrasound findings.

Materials and methods

Retrospective review of patients who underwent primary surgery for head and neck cancer followed by ALT flap reconstruction at our institution from 2014 to 2018. All patients underwent CDS prior to surgical excision of the flap.

Results

Preoperative CDS was useful to identify the location of the vascular perforators, to estimate the pedicle length, and to identify the vascularization variant. Using the proposed mathematical formula, the estimated minimum pedicle length and actual length agreed in 73.9% of cases, increasing to 84.1% when a 5 mm margin of error was allowed. Moreover, preoperative ultrasound accurately distinguished the two anatomical variants of the ALT vasculature in nearly all cases (97.1%).

Conclusion

This study confirms the value of preoperative colour Doppler sonography for ALT flap reconstruction. The proposed mathematical model provides a highly accurate method of preoperatively assessing the length of the vascular pedicle, which may be of value in head and neck surgery.

Medial versus lateral approach to harvesting of anterolateral thigh flap

Objective

This study was performed to evaluate two classic procedures guided by anatomic markers for harvesting the anterolateral thigh (ALT) flap: one began with an incision on the lateral side to identify perforators emerging from the muscle to the superficial tissue and to track the perforators upward to the upper stem vessel, and the other began with an incision on the medial side to identify the vessel branch from the stem artery and to track it downward to the flap perforators.

Methods

Twenty-eight consecutive patients with tissue defects repaired with ALT flaps were investigated; 13 and 15 patients underwent the lateral and medial incision technique, respectively. The surgeon’s subjective view regarding procedural difficulty and the operative times were statistically analyzed.

Results

All flaps were harvested successfully. A two-paddle flap from one thigh in the medial group failed due to necrosis; all others survived completely. Subjectively, harvesting of flaps starting with a lateral incision was somewhat difficult, and the operative time was significantly longer using the lateral technique.

Conclusions

Classic procedures to harvest the anterolateral thigh flap are still practicable, and starting with a medial incision is more efficient than starting with a lateral incision.

Type of study/level of evidence: Therapeutic IV.

Super obesity is not necessarily a contraindication to deep inferior epigastric perforator flap breast reconstruction

The deep inferior epigastric perforator (DIEP) flap is widely recognised as a safe and reliable flap for use as a first-choice option in autologous tissue breast reconstruction. Patients with obesity represent a challenging group for autologous breast reconstruction, as they are at increased risk of developing major and minor complications in comparison with patients with normal weight. We report a 59-year-old woman with super obesity, who presented to our department with right breast skin necrosis after implant reconstruction following mastectomy for right breast cancer. After implant removal and local treatment with both surgical debridement and negative pressure wound therapy, the patient successfully underwent a DIEP flap breast reconstruction. We conclude that super obesity should not be a contraindication to DIEP flap breast reconstruction.

Color Doppler Ultrasonography-Targeted Perforator Mapping and Angiosome-Based Flap Reconstruction

Knowledge about perforators and angiosomes has inspired new and innovative flap designs for reconstruction of defects throughout the body. The purpose of this article is to share our experience using color Doppler ultrasonography (CDU)-targeted perforator mapping and angiosome-based flap reconstruction throughout the body. The CDU was used to identify the largest and best-located perforator adjacent to the defect to target the reconstruction. The cutaneous or fasciocutaneous flaps were raised, mobilized, and designed according to the reconstructive needs as rotation, advancement, or turnover flaps. We performed 148 reconstructions in 130 patients. Eleven facial reconstructions, 118 reconstructions in the body, 7 in the upper limbs, and 12 in the lower limbs. The propeller flap was used in 135 of 148 (91%) cases followed by the turnover design in 10 (7%) and the V to Y flap in 3 (2%) cases. The flaps were raised on 1 perforator in 98 (67%), 2 perforators in 48 (33%), and 3 perforators in 2 (1%) flaps. The reconstructive goal was achieved in 143 of 148 reconstructions (97%). In 5 cases, surgical revision was needed. No flaps were totally lost indicating a patent pedicle in all cases. We had 10 (7%) cases of major complications and 22 (15%) minor complications. The CDU-targeted perforator mapping and angiosome-based flap reconstruction are simple to perform, and we recommended its use for freestyle perforator flap reconstruction. All perforators selected by CDU was identified during surgery and used for reconstruction. The safe boundaries of angiosomes remain to be established.

Influence of preoperative imaging on fibula free flap harvesting

INTRODUCTION

The fibula free flap (FFF) is the gold standard for the reconstruction of large maxillofacial defects. Magnetic resonance angiography (MRA) seems to supersede digital subtraction angiography (DSA) as the reference in preoperative evaluation, being non-invasive and having equivalent diagnostic results. The aim of this study was to assess the impact of preoperative MRA versus DSA on the viability of FFF and its success rate.

MATERIAL AND METHODS

A total of 216 patients, who underwent mandibular or maxillary FFF reconstruction from January 1995 to January 2011, were retrospectively included in the study. Of them, 101 patients underwent preoperative DSA and 115 underwent MRA. Recorded criteria were as follows: age, sex, tobacco consumption, defect etiology, preoperative vascular assessment, donor-site choice and flap failure. The DSA group was compared to the MRA group.

RESULTS

The harvested side was switched in 15.7% of cases with preoperative MRA versus 4% with DSA. Our success rate was higher (96.1%) with MRA than with DSA (88.1%) (P<0.05). More atherosclerotic patients (P=0.004) were diagnosed through MRA. MRA and DSA showed similar results in anatomical variation detection.

CONCLUSION

MRA is less invasive and more effective in atherosclerosis detection than DSA. Therefore, donor-site switching was more frequent in the MRA group, which led to a better success rate. MRA should replace DSA as the reference in preoperative assessment.

Three-dimensional contrast-enhanced magnetic resonance angiography for anterolateral thigh flap outlining: A retrospective case series of 68 patients

Flap transfer is increasingly used for repairing limb defects secondary to trauma or tumor, and appropriate preoperative planning plays a critical role. The present study aimed to examine the use of three-dimensional (3D) contrast-enhanced magnetic resonance angiography (CE-MRA) in evaluating the blood supply distribution and perforating branch pattern of anterolateral thigh (ALT) flaps. Bilateral donor lower limbs were scanned in 68 patients (136 limbs) using a Siemens Avanto 1.5 T magnetic resonance imaging scanner with a 3D fast low-angle shot sequence, following the thin-slab maximum intensity projection (TS-MIP) technique. The lateral femoral circumflex artery (LFCA) was visualized in all patients: 101 limbs (101/136, 74.3%) were type I; 20 limbs (20/136, 14.7%) were type II; 3 limbs (3/136, 2.2%) were type III; and 12 limbs (12/136, 8.8%) were type IV. Tertiary branches were identified in 94 limbs (94/136, 69.1%). Donor flaps were outlined according to MRA TS-MIP findings in 4 patients. All flaps survived uneventfully following the transfer. In donor flap outlining, 3D CE-MRA with the TS-MIP technique allowed an accurate, direct visualization of the branching pattern and distribution profile of the LFCA supplying the ALT flap.

Planning digital artery perforators using color Doppler ultrasonography: A preliminary report

Digital artery perforator (DAP) flaps have been applied for the coverage of finger soft tissue defects. Although an advantage of this method is that there is no scarification of the digital arteries, it is difficult to identify the location of the perforators during intraoperative elevation of the DAP flap. In this study, anatomically reliable locations of DAPs were confirmed using color Doppler ultrasonography (US) in healthy volunteers. A successful case using an adiposal-only DAP flap for the coverage of a released digital nerve using preoperative DAP mapping with color Doppler US is also described. A total of 40 digital arteries in 20 fingers of the right hands of five healthy volunteers (mean age: 32.2 years old) were evaluated. The DAPs were identified using color flow imaging based on the beat of the digital artery in the short axial view. In total, 133 perforators were detected, 76 (an average of 3.8 per finger) arising from the radial digital artery and 57 (an average of 2.9 per finger) arising from ulnar digital artery. Sixty-three perforators (an average of 3.2 per finger) in the middle phalanges and 70 (an average of 3.5 per finger) in the proximal phalanges were found. Overall, an average of 1.7 perforators from each digital artery was detected in the proximal or middle phalanges. Moreover, at least one DAP per phalanx was reliably confirmed using color Doppler US. Preoperative knowledge of DAP mapping could make elevating the DAP flap easier and safer.