Preoperative CT angiography versus Doppler ultrasound mapping of abdominal perforator in DIEP breast reconstructions: A randomized prospective study

Free-style technique versus computed tomographic angiography-guided perforator selection in deep inferior epigastric perforator flap harvest: A prospective clinical study

BACKGROUND

Computed tomographic angiography (CTA) is the preferred diagnostic tool in preoperative deep inferior epigastric perforator (DIEP) flap assessment, though some surgeons prefer approaching perforator selection with intraoperative findings alone.

METHODS

This prospective observational study conducted between 2015 and 2020 assessed our intraoperative decision-making "free-style" technique for DIEP flap harvest. Any patient with indication for immediate or delayed breast reconstruction using abdominally based flaps and who received preoperative CTA was enrolled. Only unilateral cases performed by the same surgeon were considered. Allergy to iodine-based contrast media, renal impairment and claustrophobia were other exclusion criteria. Primary endpoint consisted in comparing operative times and complication rates between free-style technique and CTA-guided approach. Secondary endpoints included evaluation of agreement rate between intraoperative findings and CTA, and identification of variables affecting operative time and complication rate. Demographics, surgical information, agreement versus non-agreement and complications were collected.

RESULTS

Starting from 206 patients, 100 were enrolled. Fifty were assigned to Group A, receiving DIEP flap with free-style technique. The other 50 were assigned to Group B, receiving DIEP flap with CTA-guided perforators selection. Study groups' demographics were homogenous. Operative time was statistically lower (p = .036) in free-style group (252.4 ± 44.77 min vs. 265.6 ± 31.67 min). Complication rates were higher in CTA-guided group (10% vs. 2%) though this was not significant (p = .092). Overall agreement rate in dominant perforator selection between intraoperatively and CTA-based assessment was 81%. Multiple regression analysis showed no variable increased complication rate, though CTA-guided approach, BMI > 30 and harvesting more than one perforator were respectively associated with B-coefficient of 17.391 (2.430-32.351, 95% CI) [p = .023], 3.50 (0.640-6.379, 95% CI) [p = .017] and 18.887 (6.232-31.542, 95% CI) [p = .004], predicting increased operative time.

CONCLUSIONS

The free-style technique proved to be a useful tool for guiding DIEP flap harvest with good sensibility in detecting the dominant perforator suggested by CTA without statistically increasing surgery duration and complications.

Virtual Reality and Augmented Reality in Plastic and Craniomaxillofacial Surgery: A Scoping Review

Virtual reality (VR) and augmented reality (AR) have evolved since their introduction to medicine in the 1990s. More powerful software, the miniaturization of hardware, and greater accessibility and affordability enabled novel applications of such virtual tools in surgical practice. This scoping review aims to conduct a comprehensive analysis of the literature by including all articles between 2018 and 2021 pertaining to VR and AR and their use by plastic and craniofacial surgeons in a clinician-as-user, patient-specific manner. From the initial 1637 articles, 10 were eligible for final review. These discussed a variety of clinical applications: perforator flaps reconstruction, mastectomy reconstruction, lymphovenous anastomosis, metopic craniosynostosis, dermal filler injection, auricular reconstruction, facial vascularized composite allotransplantation, and facial artery mapping. More than half (60%) involved VR/AR use intraoperatively with the remainder (40%) examining preoperative use. The hardware used predominantly comprised HoloLens (40%) and smartphones (40%). In total, 9/10 Studies utilized an AR platform. This review found consensus that VR/AR in plastic and craniomaxillofacial surgery has been used to enhance surgeons' knowledge of patient-specific anatomy and potentially facilitated decreased intraoperative time via preoperative planning. However, further outcome-focused research is required to better establish the usability of this technology in everyday practice.

Surgeon-conducted color Doppler ultrasound deep inferior epigastric artery perforator mapping: A cohort study and learning curve assessment

BACKGROUND

Perforator mapping using diagnostic methods facilitates deep inferior epigastric perforator (DIEP) flap planning. Computed tomographic angiography (CTA) is a well-proven tool for perforator mapping. However, the benefits of color Doppler ultrasonography (CDU) are as follows: 1) CDU involves dynamic real-time examination and 2) does not use radiation. Comparing the accuracies of both methods in a cohort of patients, this study aimed to evaluate the learning curve of surgeon-conducted CDU perforator mapping.

METHODS

Twenty patients undergoing DIEP flap breast reconstruction were enrolled in a cohort study. All patients underwent CTA perforator mapping preoperatively. XY coordinates of significant perforators were subtracted by a radiologist. A single surgeon (sonographer) with minimal experience with CDU performed CDU perforator mapping, including XY coordinates subtraction. The sonographer was blinded to the CTA data. The reference coordinates of dissected perforators were measured during surgery. Deviations from reference coordinates for both methods were compared, and CDU mapping learning curve was assessed using Joinpoint Regression.

RESULTS

We included 20 women (32 DIEP flaps and 59 dissected perforators). The mean deviation between mapped and reference coordinates was 1.00 (0.50-1.12) cm for CDU and 0.71 (0.50-1.12) cm for CTA. The learning curve of CDU mapping showed the breaking point after the seventh patient (≈ 21 localized perforators). After the breaking point, no significant differences between the deviations of both methods were found (p = 0.980).

CONCLUSION

A limited number of examinations were needed for the surgeon to learn CDU DIEA perforator mapping with accuracy similar to that of CTA mapping.

Preoperative Perforator Mapping in DIEP Flaps for Breast Reconstruction. The Impact of New Contrast-Enhanced Ultrasound Techniques

Deep inferior epigastric artery flaps (DIEP) represent the gold standard of autologous breast reconstruction. Due to significant variations in vascular anatomy, preoperative perforator mapping (PM) is mandatory in order to ensure the presence of a sufficient perforator within the flap. In this regard, CT angiography (CTA) is currently the method of choice. Therefore, we investigated the value of contrast-enhanced ultrasound (CEUS) techniques for preoperative PM in comparison to CTA. Patients underwent PM, utilizing both CTA and CEUS techniques. Documentation included the course of the vascular pedicle through the rectus muscle (M), fascial penetration (F), the subcutaneous plexus (P) and the skin point (SP) on either side of the abdomen. Thus, contrast-enhanced B-Flow (BCEUS), B-Flow ultrasound (BUS), CEUS, color Doppler ultrasound (CDUS) and CTA were evaluated in terms of the diagnostic consistency and effectiveness of PM. Precision (∆L) was then calculated in relation to the actual intraoperative location. Statistical analysis included Kruskall-Wallis, Levene and Bonferroni tests, as well as Spearman correlations. A total of 39 DIEP flaps were analyzed. Only CTA (∆L = 2.85 mm) and BCEUS (∆L = 4.57 mm) enabled complete PM, also including P and SP, whereas CDUS, CEUS and BUS enabled clear PM throughout M and F only. Regarding the number of detected perforators, PM techniques are ranked from high to low as follows: CTA, BCEUS, BUS, CEUS and CDUS. CTA and BCEUS showed sufficient diagnostic consistency for SP, P and F, while CDUS and CTA had a superior performance for M. BCEUS offers precise image-controlled surface tags and dynamic information for PM without imposing radiation and may, therefore, be considered a feasible add-on or alternative to CTA. However, BCEUS requires an experienced examiner and is more time-consuming.

ACR Appropriateness Criteria® Imaging of Deep Inferior Epigastric Arteries for Surgical Planning (Breast Reconstruction Surgery): 2022 Update

Breast cancer is the most common malignancy in women in the United States, with surgical options including lumpectomy and mastectomy followed by breast reconstruction. Deep inferior epigastric perforator (DIEP) flap is a muscle-sparing perforator free flap breast reconstruction technique, which uses the deep inferior epigastric artery (DIEA) perforators to create a vascular pedicle. Multiple perforators are identified by preoperative imaging, which are typically ranked based on size, location, and intramuscular course. The goal of preoperative imaging is to aid the surgical team in preoperative planning given the variability of the DIEA perforator branches anatomy between patients. The objective of this document is to review the imaging modalities that can be used preoperatively to identify the optimal perforator and thereby reduce intraoperative complications, reduce postoperative complications, and improve clinical outcomes. The ACR Appropriateness Criteria are evidence-based guidelines for specific clinical conditions that are reviewed annually by a multidisciplinary expert panel. The guideline development and revision process support the systematic analysis of the medical literature from peer reviewed journals. Established methodology principles such as Grading of Recommendations Assessment, Development, and Evaluation or GRADE are adapted to evaluate the evidence. The RAND/UCLA Appropriateness Method User Manual provides the methodology to determine the appropriateness of imaging and treatment procedures for specific clinical scenarios. In those instances in which peer reviewed literature is lacking or equivocal, experts may be the primary evidentiary source available to formulate a recommendation.

A Comparison of Handheld Doppler and Indocyanine Green Angiography for Perforator Localization

BACKGROUND

The preoperative identification of perforators is critical to the success of perforator flaps. Several technologies, including handheld Doppler (HHD) and indocyanine green angiography (ICGA), facilitate this process; however, each technology comes with unique downsides. This study directly compares the performance of HHD and ICGA in preoperative perforator identification and measures the effects of flap thickness and body mass index (BMI) on perforator localization.

METHOD

Data from preoperative HHD and ICGA assessments were compared with the criterion standard of intraoperative perforator localization. Sensitivity, specificity, accuracy, and positive predictive values were calculated for both and correlated with flap thickness and BMI.

RESULTS

Thirty flaps were transferred in 30 patients across 15 different donor sites. Indocyanine green angiography had higher sensitivity, accuracy, and positive predictive value (79.2%, 74.2%, and 87.5%, respectively) than HHD (55.6%, 46.6%, and 69.4%, respectively). Perforators detected by ICGA were used as flap pedicles in 21 cases compared with 13 with HHD. There were no correlations between HHD or ICGA performance and patient BMI (both P > 0.05). Increasing flap thickness was negatively correlated with the accuracy of ICGA ( P = 0.001) but not HHD ( P > 0.05).

CONCLUSIONS

Indocyanine green angiography was more sensitive, specific, and accurate than HHD in identifying perforators across various donor sites; however, its performance suffered in thicker flaps, whereas HHD did not. Patient BMI was not correlated with the performance of either technology. Additional research can further delineate the interrelationships of flap thickness and technologies for perforator localization.

Current Applications of Ultrasound Imaging in the Preoperative Planning of DIEP Flaps

Background The deep inferior epigastric artery perforator (DIEP) flap has become the gold standard for autologous breast reconstruction at many institutions. Although the deep inferior epigastric artery displays significant anatomic variability in its intramuscular course, branching pattern and location of perforating vessels, the ability to preoperatively visualize and map relevant vascular anatomy has increased the efficiency, safety and reliability of the DIEP flap. While computed tomography angiography (CTA) is often cited as the preoperative imaging modality of choice for perforator flaps, more recent advances in ultrasound technology have made it an increasingly attractive alternative.

Methods An extensive literature review was performed to identify the most common applications of ultrasound technology in the preoperative planning of DIEP flaps.

Results This review demonstrated that multiple potential uses for ultrasound technology in DIEP flap reconstruction including preoperative perforator mapping, evaluation of the superficial inferior epigastric system and as a potential adjunct in flap delay procedures. Available studies suggest that ultrasound compares favorably to other widely-used imaging modalities for these indications.

Conclusion This article presents an in-depth review of the current applications of ultrasound in the preoperative planning of DIEP flaps and explores some potential areas for future investigation.

[A pedicled deep inferior epigastric flap to cover a hip arthroplasty infection]

The deep inferior epigastric perforator (DIEP) flap is a reliable flap mostly used in skin resurfacing after signifiant resection for sarcoma or correction contour deformities. This case is about a pedicled DIEP flap covering the trochanteric region after a total hip arthroplasty infection. A 62years old woman with a BMI at 42kg/m² presents an infected total hip arthroplasty with a cutaneous defect. The hip prosthesis is changed and covered with a pedicled DIEP flap. This original case reports the used of pedicled DIEP flap in hip coverage. This local fasciocutaneous flap covered the hip osteoarticular infection. The limb is salved and the patient can walked again. The success of this surgery is the collaboration between infectious disease specialist, orthopedic surgeon and plastic surgeon.

Conventional CT versus Dedicated CT Angiography in DIEP Flap Planning: A Feasibility Study

The deep inferior epigastric perforator (DIEP) flap is used with increasing frequency in post-mastectomy breast reconstruction. Preoperative mapping with CT angiography (CTa) is crucial in reducing surgical complications and optimizing surgical techniques. Our study’s goal was to investigate the accuracy of conventional CT (cCT), performed during disease staging, compared to CTa in preoperative DIEP flap planning. In this retrospective, single-center study, we enrolled patients scheduled for mastectomy and DIEP flap breast reconstruction, subjected to cCT within 24 months after CTa. We included 35 patients in the study. cCT accuracy was 95% (CI 0.80–0.98) in assessing the three largest perforators, 100% (CI 0.89–100) in assessing the dominant perforator, 93% (CI 0.71–0.94) in assessing the perforator intramuscular course, and 90.6% (CI 0.79–0.98) in assessing superficial venous communications. Superficial inferior epigastric artery (SIEA) caliber was recognized in 90% of cases (CI 0.84–0.99), with an excellent assessment of superficial inferior epigastric vein (SIEV) integrity (96% of cases, CI 0.84–0.99), and a lower accuracy in the evaluation of deep inferior epigastric artery (DIEA) branching type (85% of cases, CI 0.69–0.93). The mean X-ray dose spared would have been 788 ± 255 mGy/cm. Our study shows that cCT is as accurate as CTa in DIEP flap surgery planning.

The accuracy of different modalities of perforator mapping for unilateral DIEP flap breast reconstruction: A systematic review and meta-analysis

BACKGROUND

Perforator mapping may be performed prior to deep inferior epigastric perforator (DIEP) flap breast reconstruction to guide perforator selection. However, the accuracy of different imaging modalities remains unknown. This review aimed to evaluate the accuracy of different modalities for locating perforators for unipedicled DIEP flap breast reconstruction.

METHODS

MEDLINE and EMBASE were searched from inception to 24th September 2019 for studies concerning adult women undergoing DIEP flap breast reconstruction with preoperative perforator mapping. The index test was pre-operative imaging and the reference standard was intraoperative identification.

RESULTS

21 articles with 1146 women were included. Six methods were described; handheld doppler, colour doppler (duplex) ultrasonography, computed tomography angiography, magnetic resonance angiography (MRA), direct infrared thermography with and without doppler. Meta-analysis revealed 94% (95% CI 88-99%) of DIEPs identified as the 'dominant perforator' on imaging were chosen as dominant perforators intraoperatively. Colour doppler (Duplex) ultrasonography had the lowest agreement (mean 74% [95% CI 67-81%]) whilst MRA had the highest agreement (mean 97% [95% CI 86-100%]). There was no statistically significant difference in the performance of different tests. All studies were subject to bias as the operators had knowledge of the index test prior to conducting the reference standard.

CONCLUSIONS

Based upon limited evidence, cross sectional (CT/MR) imaging modalities for preoperative DIEP mapping appear to have similar accuracy and perform better than ultrasound.

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 Mapping Practice for Deep Inferior Epigastric Artery Perforator Flap Reconstructions: A Survey of the Benelux Region

BACKGROUND

 Numerous new and novel imaging techniques for preoperative perforator selection in deep inferior epigastric artery perforator (DIEP) flap planning have been introduced. To what extent, these have been adopted into or replaced routine practice has hitherto remained unknown. The purpose of this study was to identify the currently preferred technique by reconstructive surgeons, the criteria that they regard as most relevant and what impact these have on the preoperative decision-making.

METHODS

 An online survey consisting of 25 questions was sent to members of the Benelux Societies for Plastic Surgery. Information regarding experience and preferred imaging modality was requested. Specific questions addressed the utilization of computed tomography angiography (CTA) and factors that could inform preoperative perforator selection. Results were anonymously collected, managed using REDCap, and analyzed using Chi-square statistic.

RESULTS

 Seventy-nine principal surgeons could be included. A variation in surgeon experience was observed. On CTA, the preferred imaging modality, large-caliber vessels, the location of the perforator in the flap, and its intramuscular course were considered the most significant criteria. Surgeons doing more than 20 DIEP flaps per year are less concerned about the distance of the perforator from the umbilicus (p = 0.003) but more likely to choose a medial perforator (p = 0.011). No statistical difference was found in surgeons' experience between those who would choose and use one specific (medial or lateral) perforator when they are analogous on CTA, and those who would delay the decision until both perforators have been exposed.

CONCLUSION

 Advantages and disadvantages of the current practice of preoperative perforator selection by surgeons who are primarily responsible for harvesting a DIEP flap have been clearly identified. Indications are that these could be widely representative in which case, the quest for a protocol or modality that maximizes the benefit and minimizes harm in preoperative perforator mapping is urgently required.

Automatic detection of perforators for microsurgical reconstruction

The deep inferior epigastric perforator (DIEP) is the most commonly used free flap in mastectomy reconstruction. Preoperative imaging techniques are routinely used to detect location, diameter and course of perforators, with direct intervention from the imaging team, who subsequently draw a chart that will help surgeons choosing the best vascular support for the reconstruction. In this work, the feasibility of using a computer software to support the preoperative planning of 40 patients proposed for breast reconstruction with a DIEP flap is evaluated for the first time. Blood vessel centreline extraction and local characterization algorithms are applied to identify perforators and compared with the manual mapping, aiming to reduce the time spent by the imaging team, as well as the inherent subjectivity to the task. Comparing with the measures taken during surgery, the software calibre estimates were worse for vessels smaller than 1.5 mm (P = 6e-4) but better for the remaining ones (P = 2e-3). Regarding vessel location, the vertical component of the software output was significantly different from the manual measure (P = 0.02), nonetheless that was irrelevant during surgery as errors in the order of 2-3 mm do not have impact in the dissection step. Our trials support that a reduction of the time spent is achievable using the automatic tool (about 2 h/case). The introduction of artificial intelligence in clinical practice intends to simplify the work of health professionals and to provide better outcomes to patients. This pilot study paves the way for a success story.

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.

Body mass index and abdominal wall thickness correlate with perforator caliber in free abdominal tissue transfer for breast reconstruction

INTRODUCTION

The aim of the study was to investigate the relationship of BMI and abdominal wall thickness (AWT) with the diameter of the dominant deep inferior epigastric artery perforator (DIEP) as well as DIEA branching pattern in preoperatively performed computed tomography angiography (CTA).

PATIENTS AND METHODS

We conducted a retrospective study including all patients undergoing DIEP flap breast reconstruction with available CTAs from November 2013 to April 2018 in our department. The caliber-strongest DIEP was detected after passage of the rectus fascia as well as the superficial inferior epigastric artery (SIEA) and correlated with the AWT 5 cm above and below the umbilicus, lateral at the level of the umbilicus and at the level of the anterior superior iliac spine (ASIS), and with BMI.

RESULTS

Seventy-seven patients met the inclusion criteria (age: 47.3 ± 8.9 years). We observed a significant relationship (p < 0.05) between DIEP (mean ∅ = 2.98 mm) and BMI (r = 0.353), the AWT supra- and infraumbilical (r ≥ 0.32), and the AWT lateral at the level of the umbilicus and ASIS (r ≥ 0.25). In addition, there was a highly significant correlation (p < 0.01) between SIEA and BMI (r = 0.389) and between the AWT lateral at the level of ASIS (r ≥ 0.41).

CONCLUSION

We demonstrated a correlation of the diameter of the dominant DIEP with both BMI and AWT. Focusing on the diameter, in patients with a high AWT at the level of the ASIS, the SIEA, if present, may represent an alternative therapeutic option.

A review of visualized preoperative imaging with a focus on surgical procedures of the breast

Preoperative imaging has become a valuable tool in the planning of perforator flaps, and to date, computed tomographic angiography (CTA) has been shown to be the gold standard in this role. The evidence for this is a source of constant investigation, with advances in newer modalities coming to the fore. A literature review was undertaken to evaluate the current role of relevant imaging modalities in 'visualized surgery'-the ability to map anatomy prior to surgical incision. A focus is made on their accuracy in perforator mapping and correlation with improved clinical outcomes in the context of deep inferior epigastric artery perforator (DIEP) flap surgery. Other applications for preoperative imaging in breast surgery such as imaging of alternate donor sites or of the recipient site and imaging for volumetric assessment are also discussed. Preoperative imaging is integral to the planning of reconstructive breast surgery. This review has discussed the range of imaging techniques used to map and visualize perforator vasculature, and whilst there are varied clinical applications for the imaging modalities, CTA has been demonstrated to be the most precise and to confer the best clinical outcomes. Applications of the other imaging techniques are varied and these should remain as valid alternatives, particularly for patients where radiation or contrast exposure should be limited. Further studies could focus on the development of a more definitive protocol regarding the approach to preoperative imaging in breast surgery.

The Expanding Role of Diagnostic Ultrasound in Plastic Surgery

Supplemental Digital Content is available in the text.

Background:

Ultrasound in plastic surgery is quickly finding new applications. Ultrasound surveillance may replace ineffective individual risk stratification and chemoprophylaxis for deep venous thromboses. Abdominal penetration can be a catastrophic complication of liposuction. Preoperative screening for fascial defects may reduce risk. Limiting buttock fat injections to the subcutaneous plane is critical for patient safety, but it is difficult to know one’s injection plane.

Methods:

The author’s use of diagnostic ultrasound was evaluated from May 2017 to May 2018. Ultrasound scans were used routinely to detect deep venous thromboses. Patients undergoing abdominal liposuction and/or abdominoplasty were scanned for possible hernias. Other common applications included the evaluation of breast implants, breast masses, and seroma management. The device was used in surgery in 3 patients to assess the plane of buttock fat injection.

Results:

One thousand ultrasound scans were performed during the 1-year study period. A distal deep venous thrombosis was detected in 2 patients. In both cases, the thrombosis resolved within 1 month, confirmed by follow-up ultrasound scans. A lateral (tangential) fat injection method was shown to safely deposit fat above the gluteus maximus fascia.

Conclusions:

Ultrasound scans are highly accurate, noninvasive, and well-tolerated by patients. Some of these applications are likely to improve patient safety. Early detection of deep venous thromboses is possible. Unnecessary anticoagulation may be avoided. Subclinical abdominal defects may be detected. Ultrasound may be used in the office to evaluate breast implants, masses, and seromas. In surgery, this device confirms the level of buttock fat injection.

Through the HoloLens™ looking glass: augmented reality for extremity reconstruction surgery using 3D vascular models with perforating vessels

Precision and planning are key to reconstructive surgery. Augmented reality (AR) can bring the information within preoperative computed tomography angiography (CTA) imaging to life, allowing the surgeon to ‘see through’ the patient’s skin and appreciate the underlying anatomy without making a single incision. This work has demonstrated that AR can assist the accurate identification, dissection and execution of vascular pedunculated flaps during reconstructive surgery. Separate volumes of osseous, vascular, skin, soft tissue structures and relevant vascular perforators were delineated from preoperative CTA scans to generate three-dimensional images using two complementary segmentation software packages. These were converted to polygonal models and rendered by means of a custom application within the HoloLens™ stereo head-mounted display. Intraoperatively, the models were registered manually to their respective subjects by the operating surgeon using a combination of tracked hand gestures and voice commands; AR was used to aid navigation and accurate dissection. Identification of the subsurface location of vascular perforators through AR overlay was compared to the positions obtained by audible Doppler ultrasound. Through a preliminary HoloLens-assisted case series, the operating surgeon was able to demonstrate precise and efficient localisation of perforating vessels.

Perforator mapping reduces the operative time of DIEP flap breast reconstruction: A systematic review and meta-analysis of preoperative ultrasound, computed tomography and magnetic resonance angiography

BACKGROUND

Prior to DIEP flap breast reconstruction, mapping the perforators of the lower abdominal wall using ultrasound, computed tomography angiography (CTA) or magnetic resonance angiography (MRA) reduces the risk of flap failure. This review aimed to investigate the additional potential benefit of a reduction in operating time.

METHODS

We systematically searched the literature for studies concerning adult women undergoing DIEP flap breast reconstruction, which directly compared the operating times and adverse outcomes for those with and without preoperative perforator mapping by ultrasound, CTA or MRA. Outcomes were extracted, data meta-analysed and the quality of the evidence appraised.

RESULTS

Fourteen articles were included. Preoperative perforator mapping by CTA or MRA significantly reduced operating time (mean reduction of 54 minutes [95% CI 3, 105], p = 0.04), when directly compared to DIEP flap breast reconstruction with no perforator mapping. Further, perforator mapping by CTA was superior to ultrasound, as CTA saved more time in theatre (mean reduction of 58 minutes [95% CI 25, 91], p < 0.001) and was associated with a lower risk of partial flap failure (RR 0.15 [95% CI 0.04, 0.6], p = 0.007). All studies were at risk of methodological bias and the quality of the evidence was very low.

CONCLUSIONS

The quality of research regarding perforator mapping prior to DIEP flap breast reconstruction is poor and although preoperative angiography appears to save operative time, reduce morbidity and confer cost savings, higher quality research is needed.

REGISTRATION

PROSPERO ID CRD42017065012.

[Application of preoperative vascular localization techniques for perforator flaps]

With the development of microvascular technology, perforator flaps have gradually become a good alternative for reconstruction of tissue defects. However, the major limitations of perforator flaps include uncertainty in predicting anatomical location of perforators and high variability in perforator size and course, which require preoperative localization techniques. Recently, as one of the preoperative localization techniques, computed tomography angiography was used to determine the number, size, course, and exact emerging point of perforator flaps. Clinicians can reduce surgical complications and shorten operative time by using computed tomography angiography. However, only several studies reported clinical applications of computed tomography angiography. This article reviews characteristics, classification, and preoperative location techniques for perforator flaps and its problems.

Viability of five different pre- and intraoperative imaging methods for autologous breast reconstruction

Background

Autologous breast reconstruction is an integral part in the treatment of breast cancer. While computed tomography angiography (CTA) is an established preoperative diagnostic tool for microsurgeons, no study has so far evaluated and compared five different imaging methods and their value for the reconstructive team. In order to determine the feasibility of each of the tools for routine or specialized diagnostic application, the methods' efficiency and informative value were analyzed.

Methods

We retrospectively analyzed imaging data of 41 patients used for perforator location and assessment for regional perfusion and vessel patency in patients undergoing autologous breast reconstruction with deep inferior epigastric perforator flap (DIEP), transverse rectus abdominis muscle flap (TRAM), or transverse myocutaneous gracilis flap (TMG). Five different imaging techniques were used: hand held Doppler (HHD), CT angiography (CTA), macroscopic indocyanine green (ICG) video angiography, microscope-integrated ICG video angiography, and laser Doppler imaging (LDI).

Results

CTA proved to be the best tool for preoperative determination of the highly variable anatomy of the abdominal region, whereas HHD showed the same information on perforator localization with some false-positive results. Intraoperative HHD was an excellent tool for dissection and vessel patency judgment. Microscope-integrated ICG was an excellent tool to document the patency of microanastomoses. In our series, macroscopic perfusion measurement with ICG or LDI was only justified in special situations, where information on perfusion of abdominal or mastectomy flaps was required. LDI did not add any additional information.

Conclusion

Preoperative assessment should be performed by CTA with verification of the perforator location by HHD. Intraoperative HHD and microscope-integrated ICG contribute most toward the evaluation of vessel patency. ICG and LDI should only be used for special indications.