Microvascular Muscle vs. Fascio-Cutaneous Free Flaps for Reconstruction of Plantar Load-Bearing Foot Defects-An International Survey.

Background: The reconstruction of plantar load-bearing foot defects faces many plastic surgeons with a major challenge. The optimal patient- and defect-oriented reconstructive strategy must be selected. Methods: To analyze the current trends and recommendations in reconstruction of plantar load-bearing foot defects, we conducted an international survey among plastic surgeons querying them about their recommendations and experiences. Results: The survey revealed that the most common strategies for reconstruction of the foot sole are locoregional and microvascular free flaps, emphasizing the relevance of plastic surgery. Among microvascular free flaps, muscle and fascio-cutaneous free flaps are by far the most frequently used. The target qualities of the reconstructed tissue to be considered are manifold, with adherence being the most frequently mentioned. We observed a noteworthy correlation between the utilization of muscle flaps and a preference for adherence. In addition, we identified a substantial correlation between the usage of fascio-cutaneous free flaps and further target qualities, such as good skin quality and sensitivity. Conclusions: Our findings provide insights into the clinical reality and highlight important aspects that must be considered in reconstruction of the weight-bearing areas of the foot providing support in the selection of the appropriate therapy.

The Role of Density in Achieving Volume and Weight Symmetry in Breast Reconstruction.

BACKGROUND: Knowledge of tissue and implant density is crucial in obtaining both volume and weight symmetry in unilateral breast reconstruction. Therefore, the aim of this study was to determine and compare the density of abdominal and breast tissue specimens as well as of 5th generation breast implants. METHODS: Thirty-one breast tissue and 30 abdominal tissue specimens from 61 patients undergoing either mammaplasty or abdominoplasty as well as five different 5th generation breast implants were examined. Density (g/mL) was calculated by applying the water displacement method. RESULTS: The mean specimen density was 0.94 ± 0.02 g/mL for breast tissue and 0.94 ± 0.02 g/mL for abdominal tissue, showing no significant difference (p = 0.230). Breast tissue density significantly (p = 0.04) decreased with age, while abdominal tissue did not. A regression equation to calculate the density of breast tissue corrected for age (breast density [g/mL] = 0.975-0.0007 * age) is provided. Breast tissue density was not related to body mass index, past pregnancy, or a history of breastfeeding. The breast implants had a density ranging from 0.76 to 1.03 g/mL which differed significantly from breast tissue density (-0.19 g/mL [-19.8%] to +0.09 g/mL [+9.58%]; p ≤ 0.001). CONCLUSION: Our results support the suitability of abdominal-based perforator flaps in achieving both volume and weight symmetry in unilateral autologous breast reconstruction. Abdominal flap volume can be derived one-to-one from mastectomy weight. Further, given significant brand-dependent density differences, the potential to impose weight disbalances when performing unilateral implant-based reconstructions of large breasts should be considered.

The masseteric nerve for facial reanimation: Macroscopic and histomorphometric characteristics in 106 human cadavers and comparison of axonal ratio with recipient nerves.

Peripheral facial palsy causes severe impairments. Sufficient axonal load is critical for adequate functional outcomes in reanimation procedures. The aim of our study was to attain a better understanding of the anatomy of the masseteric nerve as a donor, in order to optimize neurotization procedures. Biopsies were obtained from 106 hemifaces of fresh frozen human cadavers. Histological cross-sections were fixed, stained with PPD, and digitized. Histomorphometry and a validated software-based axon quantification were conducted. Of the 154 evaluated branches, 74 specimens were of the main trunk (MT), 40 of the anterior branch (AB), and 38 of the descending branch (DB), while two halves of one cadaver featured an additional branch. The MT showed a diameter of 1.4 ± 0.41 mm (n = 74) with 2213 ± 957 axons (n = 55). The AB diameter was 0.9 ± 0.33 mm (n = 40) with 725 ± 714 axons (n = 30). The DB diameter was 1.15 ± 0.34 mm (n = 380) with 1562 ± 926 axons (n = 30). The DB demonstrated a high axonal capacity - valuable for nerve transfers or muscle transplants. Our findings should facilitate a balanced selection of axonal load, and are potentially helpful in achieving more predictable results while preserving masseter muscle function.

Giant Penoscrotal Lymphedema-What to Do? Presentation of a Curative Treatment Algorithm.

BACKGROUND: While rare, penoscrotal lymphedema (PL) is accompanied with devastating effects on the quality of life of patients. Moreover, especially for patients with excessive (giant) PL, no standardized curative treatment has been defined. This article therefore retrospectively evaluates the authors' surgical treatment approach for giant PL, which includes resection alone or in combination with a free vascularized lymph node transfer (VLNT). METHODS: A total of ten patients met the inclusion criteria. One patient dropped out of the study before therapy commenced. Eight of the nine remaining patients presented with end-stage (giant) PL. One patient presented with manifest pitting edema. All patients were treated with penoscrotal resection and reconstruction. Additionally, five patients received VLNT into the groin or scrotum. RESULTS: The extent of the lymphedema was specified with a treatment-oriented classification system. The median follow-up was 49.0 months. No patient showed a recurrence. Patients who received VLNT into the scrotum displayed a significantly improved lymphatic transport of the scrotum. CONCLUSIONS: Advanced PL should be treated in a standardized surgical fashion as suggested by our proposed algorithm. VLNT from the lateral thoracic region into the scrotum must be considered. If treated correctly, surgical intervention of end-stage PL leads to good results with a low recurrence rate.

Using High-Resolution Ultrasound to Assess Post-Facial Paralysis Synkinesis-Machine Settings and Technical Aspects for Facial Surgeons.

BACKGROUND: Synkinesis of the facial musculature is a detrimental sequalae in post-paralytic facial palsy (PPFP) patients. Detailed knowledge on the technical requirements and device properties in a high-resolution ultrasound (HRUS) examination is mandatory for a reliable facial muscle assessment in PPFP patients. We therefore aimed to outline the key steps in a HRUS examination and extract an optimized workflow schema. METHODS: From December 2020 to April 2021, 20 patients with unilateral synkinesis underwent HRUS. All HRUS examinations were performed by the first author using US devices with linear multifrequency transducers of 4-18 MHz, including a LOGIQ E9 and a LOGIQ S7 XDclear (GE Healthcare; Milwaukee, WI, USA), as well as Philips Affinity 50G (Philips Health Systems; Eindhoven, the Netherlands). RESULTS: Higher-frequency and multifrequency linear probes ≥15 MHz provided superior imaging qualities. The selection of the preset program Small Parts, Breast or Thyroid was linked with a more detailed contrast of the imaging morphology of facial tissue layers. Frequency (Frq) = 15 MHz, Gain (Gn) = 25-35 db, Depth (D) = 1-1.5 cm, and Focus (F) = 0.5 cm enhanced the image quality and assessability. CONCLUSIONS: An optimized HRUS examination protocol for quantitative and qualitative facial muscle assessments was proposed.

New, Innovative, Three-Dimensional In Vivo Model for High-Level Microsurgical and Supermicrosurgical Training: A Replacement for Animal Models.

SUMMARY: Microsurgery and supermicrosurgery are surgical subdomains necessary for a large variety of surgical disciplines. So far, there is no training model for lymphatic surgery or perforator flap surgery, and the most commonly used microsurgical training models are living animals. However, the ethical principles of replacement, refinement, and reduction (the three Rs) of living animals for training purposes were implemented, highlighting the necessity of an animal-sparing microsurgical training model. Formed during embryogenesis, the chick chorioallantoic membrane resembles a highly vascularized, noninnervated membrane within fertilized chicken eggs. The aim of this study was to utilize the chorioallantoic membrane model as an innovative and versatile training model for supermicrosurgery and microsurgery that can reduce the number of animals used for these purposes. The variety of different sized vessels for the implementation of an anastomosis proved the chorioallantoic membrane model as a well-functioning supermicrosurgical and microsurgical training model. The circulatory system is resilient enough to withstand the mechanical stress applied to the tissue, and the patency of the implemented anastomosis can be tested for the verification of the procedures. In summary, the integration of the chorioallantoic membrane model into a surgical training program can benefit its quality by representing a realistic anatomical and physiological model with a high variety of vascular structures. Moreover, the chorioallantoic membrane model satisfies the principles of replacement, refinement, and reduction as an animal-sparing model, indicating the potential of this model as an innovative microsurgical training model for the improvement of surgical skills.

An Innovative Simulation Model for Microvascular Training.

SUMMARY: Preclinical/clinical microsurgical training is essential for clinical practice. Therefore, various training models have been established, such as synthetic and cadaveric models. The most common limitation of these models is the lack of circulation, which limits the simulation of real intraoperative circumstances. Thus, the authors aimed to create a novel model that provides blood circulation with an extracorporeal perfusion device that they attached to rat cadavers for the reestablishment of a circulatory system. Patent blue and heparin were added to the perfusion fluid to visualize circulation and to dissolve thrombosis, and indocyanine green fluorescent imaging was applied to show the perfusion of the entire body. The femoral and brachial vessels were dissected, and an end-to-end anastomosis was performed on the femoral artery. The patency of the operated vessel was visualized with indocyanine green fluorescent imaging. Indocyanine green fluorescent imaging showed appropriate vessel patency and extremity perfusion through the anastomosis. The use of this novel rat model enables a solution for ethical problems encountered when using rats for surgical training courses. By practicing on these animal-sparing models with intact circulation, microsurgical skills can be improved. Future studies on further microsurgical techniques and vascular perfusion of organs or tumors may benefit from our model.

Evaluation of Scar Quality after Treatment of Superficial Burns with Dressilk® and Suprathel®-In an Intraindividual Clinical Setting.

BACKGROUND: Various synthetic and biological wound dressings are available for the treatment of superficial burns, and standard care differs among hospitals. Nevertheless, the search for an ideal wound dressing offering a safe healing environment as well as optimal scar quality while being economically attractive is a continuing process. In recent years, Dressilk®, which consists of pure silk, has become the standard of care for the treatment of superficial burns in our hospital. However, no long-term scar-evaluation studies have been performed to compare Dressilk® with the often-used and more expensive Suprathel® in the treatment of superficial burns. METHODS: Subjective and objective scar evaluations were performed three, six, and twelve months after treatment in patients who received simultaneous treatment of 20 superficial burn wounds with both Suprathel® and Dressilk®. The evaluations were performed using the Vancouver Scar Scale, the Cutometer®, Mexameter®, Tewameter®, and the O2C®. RESULTS: Both dressings showed mostly equivalent results in subjective scar evaluations. In the objective scar evaluations, the wounds treated with Dressilk® showed a faster return to the qualities of non-injured skin. Wound areas treated with the two dressings showed no significant differences in elasticity and transepidermal water loss after 12 months. Only oxygen saturation was significantly lower in wound areas treated with Suprathel® (p = 0.008). Subjectively, wound areas treated with Dressilk® showed significantly higher pigmentation after six months, which was not apparent after 12 months. CONCLUSION: Both wound dressings led to esthetically satisfying scar recovery without significant differences from normal uninjured skin after 12 months. Therefore, Dressilk® remains an economically and clinically interesting alternative to Suprathel® for the treatment of superficial burns.

Comparing the Time-Dependent Evolution of Microcirculation in Gracilis vs. ALT Flaps Using Laser-Doppler Flowmetry and Tissue-Spectrometry.

Postoperative free flap monitoring is considered a key component of care after microsurgical reconstruction. To achieve successful flap salvage after surgical revision, early recognition of vascular compromise is required. The aim of this study was to assess and compare the time-dependent evolution of microcirculation in gracilis muscle (GM) and anterolateral thigh (ALT) flaps. This study included continuous measurements of blood flow (flow), hemoglobin oxygenation (SO2) and the relative amount of hemoglobin (rHb) using laser-doppler flowmetry and tissue-spectrometry (O2C, LEA Medizintechnik, Gießen, Germany) over a time-period of 72 h. Microcirculation was assessed in a total of 66 viable free flaps (GM n = 40; ALT n = 26). A statistically significant positive correlation between time post-anastomosis and microvascular flow was found for both GM and ALT flaps with rs = 0.384 (p < 0.001) and rs = 0.178 (p = 0.015), respectively. No significant positive or negative correlations between time post-anastomosis and SO2 were found for both GM and ALT flaps with rs = 0.052 (p = 0.387) and rs = −0.018 (p = 0.805), respectively. Overall, a significant negative correlation between time post-anastomosis and rHb was found for GM flaps with rs = −0.140 (p = 0.019). For ALT flaps, no significant positive or negative correlation was found with rs = −0.011 (p = 0.887). Microcirculation differs in different flap entities, and surgeons should be aware of these differences in order to correctly evaluate and classify the values of flow, SO2 and rHb obtained when using the O2C device for postoperative monitoring.

Finding the Optimal Surgical Incision Pattern-A Biomechanical Study.

The closure of wounds and subsequent optimal wound healing is essential to any successful surgical intervention. Especially on parts of the body with limited possibilities for local reconstruction, optimal distribution of load is essential. The aim of the present study was therefore to examine three different incision patterns, conventional straight, Lazy-S and Zigzag, with regard to their biomechanical stability and mode of failure on a porcine skin model. Our results demonstrate the superior biomechanical stability of Lazy-S and Zigzag incision patterns with perpendicular suture placement. This holds true, in particular, for Zigzag incisions, which showed the highest values for all parameters assessed. Moreover, the observed superior stability of Lazy-S and Zigzag incision patterns was diminished when sutures were placed in tensile direction. The conventional straight incision represents the standard access for a large number of surgical procedures. However, we were able to demonstrate the superior biomechanical stability of alternative incision patterns, in particular the Zigzag incision. This is most likely caused by an improved distribution of tensile force across the wound due to the perpendicular placement of sutures. Moreover, this technique offers additional advantages, such as a better overview of the operated area as well as several cosmetic improvements. We therefore advocate that the surgeon should consider the use of a Zigzag incision over a conventional straight incision pattern.

Technical Aspects of High-Resolution Color-Coded Duplex Sonography for the Design of Perforator Flaps.

BACKGROUND: Technical aspects are of utmost significance for an efficient execution in designing perforator flaps with high-resolution color-coded Duplex sonography (CCDS). The following study evaluates decisive factors for a successful microvessel examination conducted by the microsurgeon. METHODS: Technical knowledge presented in this study was based on a series of more than 200 perforator flaps planned with CCDS. Flap reconstructions were performed at the University Hospital Regensburg, Germany, from July 2013 to January 2021. Standard high-resolution ultrasound (US) devices with linear multifrequency transducers of 4 to 18 MHz were used. Modes and device settings were evaluated regarding applicability by microsurgeons. Key steps for safe perforator identification and further optional steps for additional assessment should be discriminated. RESULTS: Different US modes including brightness mode (B-mode), color flow (CF), power Doppler (PD), pulse wave (PW), and blood flow (B-Flow) were used. Transducers from 15 MHz and up were favorable to detect microvessels. Knobology of a standard US device regarding buttons, switches, and specific onscreen options with relevance for perforator mapping was subcategorized in four different groups. For qualitative and quantitative evaluation of microvessels, different US modes were tested with respect to their usefulness.Vital elements of the CCDS exam are disaggregated into three key steps for safe perforator identification and three optional steps for further perforator characterization. A standardized protocol for the CCDS exams was applied. Downregulation of pulse-repetition frequency/scale to adapt device sensitivity to slow-flow velocities represented the most important criterion to visualize microvessels.Qualitative microvessel evaluation was performed in B-mode, CCDS, PD mode, and B-Flow mode. Quantitative assessment was executed using PW-mode and CCDS measuring the microvessels' diameter (mm) and flow characteristics. Quantitative information may be obtained using PW-mode and the distance-measuring tool in CF-mode. CONCLUSION: Technical aspects with respect to proper device trimming and application decisively impact CCDS-guided perforator vessel identification and evaluation.

Comparison of venous couplers versus hand-sewn technique in 4577 cases of DIEP-flap breast reconstructions - A multicenter study.

INTRODUCTION: Venous anastomosis remains to be a challenging step in microsurgical tissue transfer and venous complications constitute to a common reason for free flap failure. While several studies have compared mechanical vs. hand-sewn venous anastomoses, there is no large-series study comparing the type of anastomosis exclusively in DIEP flap breast reconstructions. PATIENTS AND METHODS: Between 2011 and 2019, 3926 female patients underwent 4577 free DIEP-flap breast reconstructions in 22 different breast cancer centers. Patient data was collected via an online database, files were screened and cases were divided into a hand- (HA) and a coupler-anastomosis (CA) group. Complications were accounted for and the two groups were then compared. RESULTS: Mean ischemia time was significantly shorter in the CA group (46.88 ± 26.17 vs. 55.48 ± 24.70 min; p < .001), whereas mean operative time was comparable (316 ± 134.01 vs. 320.77 ± 120.29 minutes; p = .294). We found no significant difference between both groups regarding the rate of partial (CA: 1.0% vs. HA: 1.3%) and total flap loss (CA: 2.2% vs. HA: 1.8%). However, revision rates were significantly higher in the CA group (CA: 10.5% vs. HA: 7.9%; p = .003), with higher numbers of arterial (2.3 vs. 0.9%; p < .001) and venous thromboses (3.4 vs. 1.8%; p = .001) accounting for this finding. CONCLUSIONS: All taken into account, our findings do support the feasibility of venous coupler anastomoses in principle, however the inflationary use of coupler devices should be evaluated critically.

Simultaneous Fat Injection for Nasal Contouring in Orthognathic Patients.

BACKGROUND: Augmentation rhinoplasty with autologous fat grafting is a useful procedure to meet the demand for facial harmonization in the Asian population. We used this procedure during orthognathic surgery to address inadequate dorsum projection. This prospective study was conducted to determine the fat retention rate in patients undergoing simultaneous autologous fat injection augmentation rhinoplasty and orthognathic surgery. METHODS: Nineteen patients were treated with simultaneous bimaxillary orthognathic surgery and autologous fat grafting of the nasal dorsum and tip. The paired t test was used to compare the nasal volumes before and at least 6 months after surgery measured by 3-dimensional computer tomography scans. All measurements were performed twice by the same evaluator at least 2 weeks apart for intrarater consistency. RESULTS: Seventeen patients completed the study. The volume means before and after surgery were 22.3 ± 4.6 cm3 and 23.3 ± 4.7 cm3, respectively, with a mean difference of 1.0 ± 0.3 cm3 (P < .001). The mean retention rate was calculated to be 50.5% ± 7.0% (range: 40.5%-64.7%). Intrarater consistency was high with a Cronbach α of .97 (P < .001) and .98 (P < .001), respectively. CONCLUSION: This prospective study provides objective graft retention measurements for fat injection augmentation rhinoplasty combined with orthognathic surgery. All patients were satisfied with the results and no complications or additional morbidity was noted in the postoperative course. We consider this procedure to be a safe, reliable, and powerful adjunct to improve the aesthetic results of orthognathic surgery.

Impact of patients' gender on microvascular lower extremity reconstruction.

The physiological differences between genders have significant implications for health and disease. With regard to microsurgery, results remain elusive as to whether male or female gender is an independent risk factor for free flap reconstruction. This study evaluated the impact of gender on outcomes of lower-extremity free-flap reconstructions. Within 7 years, 358 patients received 393 microvascular lower limb free flap reconstructions. The cases were divided into two groups according to patients' gender: male vs. female. Retrospective data analysis evaluated patients' demographics, perioperative details, surgical complications and flap outcomes over a 3-month follow-up period. Major and minor surgical complications, including total and partial flap loss, showed no significant differences between the investigated groups (p>.05). In addition, there was no significant difference with regard to the rate of surgical revision surgery, or the incidence of arterial and venous thrombosis (p>.05). Comparison of different flap types (fasciocutaneous ALT vs. gracilis muscle flaps) and type of anastomosis (end-to-end vs. end-to-side) also revealed no difference in outcomes in respect to gender. In conclusion, gender cannot be regarded as an independent risk factor for free flap reconstructions in patients with lower-extremity defects.

Do-It-Yourself Preoperative High-Resolution Ultrasound-Guided Flap Design of the Superficial Circumflex Iliac Artery Perforator Flap (SCIP).

The superficial circumflex iliac artery perforator (SCIP) flap is a well-documented, thin, free tissue flap with a minimal donor site morbidity, and has the potential to become the new method for resurfacing moderate-size skin defects. The aim of this study is to describe an easy, reliable, systematic, and standardized approach for preoperative SCIP flap design and perforator characterization, using color-coded duplex sonography (CCDS). A list of customized settings and a straightforward algorithm are presented, which are easily applied by an operator with minimal experience. Specific settings for SCIP flap perforator evaluation were investigated and tested on 12 patients. Deep and superficial superficial circumflex iliac artery (SCIA) branches, along with their corresponding perforators and cutaneous veins, were marked individually with a permanent marker and the anatomy was verified intraoperatively. From this, a simplified procedure for preoperative flap design of the SCIP flap was developed. Branches could be localized and evaluated in all patients. A preoperative structured procedure for ultrasonically guided flap design of the SCIP flap is described. A 100% correlation between the number and emergence points of the branches detected by preoperative CCDS mapping and the intraoperative anatomy was found.

How to Approach Secondary Breast Reduction: International Trends and a Systematic Review of the Literature.

BACKGROUND: Secondary breast reduction is complex and poses significant challenges to surgeons. Complication rates exceed those of primary reduction, commonly caused by impaired vascular supply of the nipple-areolar complex (NAC). Literature on the topic is scare and provides contradicting recommendations, especially with regard to pedicle choice in cases with unknown primary reduction technique. Aim of this study was to investigate international trends and to compare findings with literature. METHODS: A large-scale web-based questionnaire on international trends in mammaplasty (mastopexy and breast reduction) was designed and distributed to over five thousand surgeons in eight geographic regions. The presented manuscript evaluated information regarding pedicle choice in secondary breast reduction and compared data to literature identified in a systematic review. RESULTS: The survey was completed by 1431 participants. Overall, secondary procedures were performed in less than 5% or in 5 to 10% of cases. The preferred pedicle for secondary reductions differed significantly between geographic regions (p<0.001). The majority of respondents reported to use a superior or supero-medial pedicle (34.8% and 32.2%, respectively). Residual analysis revealed a strong association between the use of an inferior pedicle and procedures performed in North America. CONCLUSIONS: Secondary breast reduction is challenging and there remains international disparity with regard to pedicle choice for secondary procedures. Studies investigating outcome when the primary pedicle is unknown are scarce and provide incoherent recommendations. High-quality data is needed to provide evidence-based practice guidelines. LEVEL OF EVIDENCE III: This journal requires that authors assign a level of evidence to each article. For a full description of these Evidence-Based Medicine ratings, please refer to the Table of Contents or the online Instructions to Authors www.springer.com/00266.

Overall Complication Rates of DIEP Flap Breast Reconstructions in Germany-A Multi-Center Analysis Based on the DGPRÄC Prospective National Online Registry for Microsurgical Breast Reconstructions.

While autologous breast reconstruction has gained momentum over recent years, there is limited data on the structure and quality of care of microsurgical breast reconstruction in Germany. Using the breast reconstruction database established by the German Society of Plastic, Reconstructive and Aesthetic Surgeons (DGPRÄC), the presented study investigated the overall outcomes of deep inferior epigastric perforator (DIEP) flap reconstructions in Germany. Data of 3926 patients and 4577 DIEP flaps performed by 22 centers were included in this study. Demographics, patient characteristics, perioperative details and postoperative outcomes were accounted for. Centers performing < Ø 40 (low-volume (LV)) vs. ≥ Ø 40 (high-volume (HV)) annual DIEP flaps were analyzed separately. Overall, total and partial flap loss rates were as low as 2.0% and 1.1% respectively, and emergent vascular revision surgery was performed in 4.3% of cases. Revision surgery due to wound complications was conducted in 8.3% of all cases. Mean operative time and length of hospital stay was significantly shorter in the HV group (LV: 385.82 min vs. HV: 287.14 min; LV: 9.04 (18.87) days vs. HV: 8.21 (5.04) days; both p < 0.05). The outcome and complication rates deduced from the national registry underline the high standard of microsurgical breast reconstruction on a national level in Germany.

Effect of Radiation Therapy on Microsurgical Deep Inferior Epigastric Perforator Flap Breast Reconstructions: A Matched Cohort Analysis of 4577 Cases.

INTRODUCTION: Breast reconstruction with autologous tissue is a state-of-the art procedure. Several patient-related factors have been identified with regard to the safety and efficacy of these reconstructions. The presented study investigates the impact of prereconstruction radiation on outcomes of deep inferior epigastric perforator (DIEP) free-flap breast reconstructions using largest database available in Europe. MATERIALS AND METHODS: Between 2011 and 2019, 3926 female patients underwent 4577 DIEP flap breast reconstructions in 22 different German breast cancer centers. The cases were divided into a no-radiation (NR) and a radiation (R) group, according to radiation status before reconstruction. Groups were compared with regard to surgical complications and free-flap outcome. RESULTS: Overall, there was no significant difference between the groups regarding the rate of total flap loss [1.9% (NR) vs 2.1% (R), P = 0.743], partial flap loss [0.9% (NR) vs 1.5 (R), P = 0.069], and revision surgery [vascular revision: 4.4% (NR) vs 4.1% (R), P = 0.686; wound revision: 7.6% (NR) vs 9.4% (R), P = 0.122]. However, the patients had a significantly higher risk of developing wound healing disturbances at the recipient site [1.2% (NR) vs 2.1% (R), P = 0.035] and showed significantly longer hospitalization {8 [SD, 8.4 (NR)] vs 9 [SD, 15.4 {R}] days, P = 0.006} after prereconstruction radiation. CONCLUSIONS: Our findings suggest that DIEP flap reconstruction after radiation therapy is feasible. Women with a history of radiation therapy should, however, be informed in detail about the higher risk for wound healing disturbances at the recipient site.

Laser speckle contrast analysis (LASCA) technology for the semiquantitative measurement of angiogenesis in in-ovo-tumor-model.

BACKGROUND: The process of angiogenesis is a key element for tumor growth and proliferation and therefore one of the determining factors for aggressiveness and malignancy. A better understanding of the underlying processes of tumor induced angiogenesis is crucial for superior cancer treatment. Furthermore, the PeriCam perfusion speckle imager (PSI) system high resolution (HR) model by PERIMED presents a noninvasive method for semi-quantitative measurement of blood perfusion, based on laser speckle contrast analysis (LASCA). Aim of the present study was to utilize the chick chorioallantoic membrane (CAM) model as an in-ovo-tumor-model which enables rapid neovascularization of tumors while allowing real-time observation of the microcirculation via LASCA. METHODS: Fertilized chicken eggs were grafted with embryonal/alveolar rhabdomyosarcoma cells or primary sarcoma tumors. The blood perfusion was measured before and after tumor growth using LASCA. The procedure is accelerated and simplified through the integrated PIMSoft software which provides real-time graphs and color-coded images during the measurement. RESULTS: Sarcoma cells and primary sarcoma tumors exhibited satisfactory growth processes on the CAM. LASCA visualized microcirculation accurately and enabled an extensive investigation of the angiogenic potential of sarcoma cells on the CAM. We were able to show that sarcoma cells and primary sarcoma tumors induced larger quantities of neovasculature on the CAM than the controls. CONCLUSIONS: The utilization of LASCA for the investigation of tumor angiogenesis within the CAM model appears to be a highly beneficial, cost-efficient and easily practicable procedure. The proposed model can be used as a drug-screening model for individualized cancer therapy, especially with regards to anti-angiogenic agents.

High-Resolution Ultrasound-Guided Perforator Mapping and Characterization by the Microsurgeon in Lower Limb Reconstruction.

BACKGROUND: Preoperative ultrasound (US)-guided perforator mapping has immensely simplified perforator flap planning. It may be executed by the microsurgeon. Device settings and selection of ultrasound modes are of utmost significance for detection of low-flow microvessels. The following study evaluates different US modes. METHODS: A prospective complete data acquisition was performed from July 2018 to June 2019 in a subset of patients who underwent US-guided flap planning. Multifrequency linear transducers were used applying five US modes. Brightness (B)-mode, color flow (CF), power Doppler (PD), pulse wave (PW), and B-flow modes were evaluated regarding applicability by microsurgeons. Peak systolic velocity (PSV), end diastolic velocity (EDV), and resistance index (RI) were chosen to evaluate flow characteristics. US results were correlated to intraoperative findings. RESULTS: A total number of eight patients (six males and two females) undergoing anterolateral thigh (ALT) or superficial circumflex iliac artery perforator (SCIP) flap surgery received an extensive standardized US-guided perforator characterization. Qualitative evaluation was performed in B-mode, color-coded duplex sonography (CCDS), PD, and B-flow mode. Quantitative assessment was executed using PW-mode and CCDS measuring the microvessels' diameter (mm) and flow characteristics (PSV, EDV, and RI). CCDS provided a mean diameter of 1.93 mm (range: 1.2-2.8 ± 0.51), a mean systolic peak of 16.9 cm/s (range: 9.9-33.4 ± 7.79), and mean RI of 0.71 (range: 0.55-0.87 ± 0.09) for lower limb perforators. All perforators located with US were verified by intraoperative findings. An optimized, time-effective US mapping algorithm was derived. Qualitative parameters may be evaluated with B-mode, CF, or B-flow. Smallest microvessels may be assessed in PD-mode. Lowering pulse-repetition frequency (PRF)/scale is mandatory to image low-flow microvessels as perforators. Quantitative information may be obtained using PW-mode and the distance-measuring tool in CF-mode. Image and video materials are provided. CONCLUSION: CCDS proved to be a powerful tool for preoperative perforator characterization when using a structured approach and mapping algorithm. Different techniques may be applied for specific visualizations and performed by the microsurgeon.