Reverse contrast laser Doppler holography for lower frame rate retinal and choroidal blood flow imaging

Laser Doppler holography (LDH) is an interferometric blood flow imaging technique based on full-field measurements of the Doppler spectrum. LDH has so far been demonstrated in the retina with ultrafast cameras, typically at 75 kHz. We show here that a similar method can be implemented with camera frame rates 10 times slower than before. Due to energy conservation, low and high frequency local power Doppler signals have opposite variations, and a simple contrast inversion of the low frequency power Doppler reveals fast blood flow beyond the camera detection bandwidth for conventional laser Doppler measurements. Relevant blood flow variations and color composite power Doppler images can be obtained with camera frame rates down to a few kHz.

Spatio-temporal filtering in laser Doppler holography for retinal blood flow imaging

Laser Doppler holography (LDH) is a full-field interferometric imaging technique recently applied in ophthalmology to measure blood flow, a parameter of high clinical interest. From the temporal fluctuations of digital holograms acquired at ultrafast frame rates, LDH reveals retinal and choroidal blood flow with a few milliseconds of temporal resolution. However, LDH experiences difficulties to detect slower blood flow as it requires to work with low Doppler frequency shifts which are corrupted by eye motion. We here demonstrate the use of a spatio-temporal decomposition adapted from Doppler ultrasound that provides a basis appropriate to the discrimination of blood flow from eye motion. A singular value decomposition (SVD) can be used as a simple, robust, and efficient way to separate the Doppler fluctuations of blood flow from those of strong spatial coherence such as eye motion. We show that the SVD outperforms the conventional Fourier based filter to reveal slower blood flow, and dramatically improves the ability of LDH to reveal vessels of smaller size or with a pathologically reduced blood flow.

Breast-conserving therapy can be offered to women with prior breast augmentation

INTRODUCTION

Breast cancer in women with cosmetic breast implants is increasingly common. Over the past decade, there has been a push for mastectomy and reconstruction in these patients, based on a fear of poor aesthetic results from small breast volume, and radiation-induced capsular contracture. At the Paris Breast Centre, augmented women routinely undergo lumpectomy with whole-breast irradiation (BCT).

MATERIALS AND METHODS

A consecutive cohort of 50 augmented women, who had attempted BCT for early breast cancer at our institution between 2003 and 2018, were retrospectively identified. Post-treatment complications, oncologic outcomes, capsular contracture rates, long-term cosmetic outcomes, and patient-reported outcomes were evaluated.

RESULTS

The median follow-up was 51 months. Margins were involved in 7 women (14%); 4 of whom underwent successful re-excision, and 3 had a mastectomy, for an early mastectomy rate of 6%. There were no early complications, nor cases of early implant loss. Long-term aesthetic results were evaluated using our 5-point scale: An excellent (5), or good (4) result was obtained in 68%. Significant capsular contracture (Baker grade 3 or 4) developed in 34%, of which, 5 women underwent capsulotomy and fat grafting; 4 of 5 downstaging their Baker grade. The estimated 5-year local recurrence rate was 2.3%. Ninety-five percent of participants would recommend BCT to augmented women.

CONCLUSION

BCT is feasible and safe in augmented women with good long-term aesthetic results, and should be considered to avoid unnecessary mastectomy.

Intrascrotal injection of botulinum toxin A, a male genital aesthetic demand: Technique and limits

INTRODUCTION

Scrotal rejuvenation is a real male aesthetic demand. Scrotal injection of botulinum toxin makes the testicles smoother, less dangling and subjectively larger.

METHODS

Intrascrotal botulinum toxin injections were performed to a 44-year-old patient for aesthetic purposes. We used the intracremasteric injection protocol. Cremaster muscle injections and dartos muscle injections were performed.

RESULTS

The patient was satisfied. No adverse reaction to the intrascrotal botulinum toxin injection was observed. The patient wanted to repeat the procedure in the future.

CONCLUSION

At the moment, there is no recommendation about the aesthetic use of intrascrotal injections of botulinum toxin A and the risks are unknown. The purpose of this article is to show the feasibility, context and technical modalities of intrascrotal injection. The risk of infertility is real, but marginal for men who no longer have progeny's desire.

LEVEL OF EVIDENCE

Level 3.

SIV Infection and the HIV Proteins Tat and Nef Induce Senescence in Adipose Tissue and Human Adipose Stem Cells, Resulting in Adipocyte Dysfunction

Background: Aging is characterized by adipose tissue senescence, inflammation, and fibrosis, with trunk fat accumulation. Aging HIV-infected patients have a higher risk of trunk fat accumulation than uninfected individuals—suggesting that viral infection has a role in adipose tissue aging. We previously demonstrated that HIV/SIV infection and the Tat and Nef viral proteins were responsible for adipose tissue fibrosis and impaired adipogenesis. We hypothesized that SIV/HIV infection and viral proteins could induce adipose tissue senescence and thus lead to adipocyte dysfunctions. Methods: Features of tissue senescence were evaluated in subcutaneous and visceral adipose tissues of SIV-infected macaques and in human adipose stem cells (ASCs) exposed to Tat or Nef for up to 30 days. Results: p16 expression and p53 activation were higher in adipose tissue of SIV-infected macaques than in control macaques, indicating adipose tissue senescence. Tat and Nef induced higher senescence in ASCs, characterized by higher levels of senescence-associated beta-galactosidase activity, p16 expression, and p53 activation vs. control cells. Treatment with Tat and Nef also induced oxidative stress and mitochondrial dysfunction. Prevention of oxidative stress (using N-acetyl-cysteine) reduced senescence in ASCs. Adipocytes having differentiated from Nef-treated ASCs displayed alterations in adipogenesis with lower levels of triglyceride accumulation and adipocyte marker expression and secretion, and insulin resistance. Conclusion: HIV/SIV promotes adipose tissue senescence, which in turn may alter adipocyte function and contribute to insulin resistance.

Lower rates of lipofilling sessions in latissimus dorsi flap breast reconstruction with initial higher volume transfer by preservation of subfascial fat: A 3D camera-assisted volumetric case series

Breast reconstruction with latissimus dorsi flap (LDF) is a well-known technique, but the crucial goal is to achieve a satisfying final volume restoration. Our hypothesis is that LDF reconstruction with the preservation of subfascial fat can achieve a higher volume in a one-time procedure than that achieved in a classic LDF harvest. The aim of the study was to quantify the volume resorption in LDF reconstructions with the preservation of subfascial fat. Fifteen breasts were reconstructed with a simple LDF and the remaining 15 with an LDF with the preservation of the subfascial fat between January 2016 and May 2017. Secondly, every patient underwent a lipofilling procedure. A supplemental lipofilling procedure was performed in unsatisfying cases. A Structure-Sensor camera manufactured by Occipital^Ⓡ was used. Each patient received a 3D measurement during immediate postoperative care and then after 3 and 6 months of follow-up. This study shows no difference in volume retention at follow-up between the 2 techniques. The gain of an immediate and stable fatty layer in LDF + subfascial fat technique leads to breast volume improvement in one surgical step. Breast reconstruction with LDF and subfascial fat can be defined as a reliable solution, which provides an optimal result with a reduced number of surgical interventions when compared with a simple LDF.

Waveform analysis of human retinal and choroidal blood flow with laser Doppler holography

Laser Doppler holography was introduced as a full-field imaging technique to measure blood flow in the retina and choroid with an as yet unrivaled temporal resolution. We here investigate separating the different contributions to the power Doppler signal in order to isolate the flow waveforms of vessels in the posterior pole of the human eye. Distinct flow behaviors are found in retinal arteries and veins with seemingly interrelated waveforms. We demonstrate a full field mapping of the local resistivity index, and the possibility to perform unambiguous identification of retinal arteries and veins on the basis of their systolodiastolic variations. Finally we investigate the arterial flow waveforms in the retina and choroid and find synchronous and similar waveforms, although with a lower pulsatility in choroidal arteries. This work demonstrates the potential held by laser Doppler holography to study ocular hemodynamics in healthy and diseased eyes.

Coverage of radial forearm flap donor site with full thickness skin graft and Matriderm®: An alternative reliable solution?

PURPOSE

After harvesting a radial forearm flap (RFF) an optimal aesthetic and functional restitution of the donor site is required. In order to cover the secondary defect of the donor site, several solutions are currently available, but there is still no real evidence of the most reliable option. A retrospective study was conducted in order to evaluate a new technique of forearm coverage with artificial dermis: the association of full thickness skin graft (FTSG) with Matriderm®.

METHODS

Our study included all RFF performed during a 34-month period. Forty-three forearm secondary defects after harvesting a RFF (16 men, 27 female) were included. Forearm donor site was covered using three techniques: a simple FTSG, split thickness skin graft (STSG) with Matriderm® or FTSG with Matriderm®. Clinical evaluations based on residual functionality, skin quality and aesthetic result were assessed using respectively the Disabilities of the Arm, Shoulder and Hand (DASH) score, the Vancouver Scar Scale (VSS) score and a blind panel questionnaire.

RESULTS

FTSG with Matriderm® showed an improved DASH (10.6/100) and VSS score (5.5/13) if compared to the other techniques, mean surgeon satisfaction score was 3/5, mean patient satisfaction score was 3/5 in the FTSG with Matriderm® group.

CONCLUSION

The results of this study revealed that the new association of FTSG with Matriderm® improves the DASH score and the aesthetic outcomes resulting to be a reliable solution in treating full thickness forearm skin defects after RFF harvesting.

[Bilateral breast reduction and obesity: What is the ideal resection enabling significant improvement in back pain according to the body mass index?]

INTRODUCTION

Dorsal pain is the first symptoms about which patients with macromasty complain. Health insurance reimbursement takes place if the resection weight is at least 300grams per breast. However, this weight is not correlated with the body mass index (BMI). In this context, we sought to determine the ideal resection weight leading to significant BMI-based improvement.

MATERIALS AND METHODS

This is a multicentre prospective study of patients operated between November 2016 and July 2017. In the year following the surgical procedure, we studied overall improvement using the INDIC questionnaire. Any INDIC improvement of at least 50% was considered positive. These data were then compared to tissue resection weights and BMI. In order to refine our results, age, bra size, comorbidities and complications were also identified.

RESULTS

Forty-one patients were included in our study. Average age was 41.5±11.4years. Average BMI was 27.9±4.1kg/m². The bra cap chosen after the procedure were C. Average resection weight was 663±352g per breast. The preoperative and postoperative INDIC scores were 734.9±226.6 points and 225.3±319.1 points, respectively (P=0.001). Significant improvement was achieved at 12months in 71.8% of patients. A correlation of 38.7g/kg/m² was found between breast resection weight and BMI.

CONCLUSION

This study clarifies the correlation between the breast resection weight required to relieve optimal back pain and BMI. It defines three categories of patients: patients with standard weights (18<BMI<25), overweight (25<BMI<30) and obese (BMI>30). Overweight and obese patients require greater tissue excretion to be relieved optimally. These findings underline a need to adjust the health insurance threshold for these types of patients.

[Tongue reconstruction by thoracodorsal perforator flap: A new harvesting technique to reduce morbidity]

The thoracodorsal artery perforator flap is increasingly used in head and neck reconstructions. One of its multiple advantages is the low donor site morbidity compared to the other free flaps usually used for this type of surgery, such as the radial forearm free flap and the anterolateral flap of the thigh. However, the current harvesting technique of the thoracodorsal artery free perforator flap needs a vertical incision rising high in the axillary hollow for the dissection of the pedicle, thus impeding optimal discretion of the donor site, especially for women. We describe an original technique to harvest a pure transversal skin paddle on its own perforator, leaving a horizontal scar thoroughly hidden in the bra and preserving the thoracodorsal pedicle. We detail the requirements for this new type of harvesting.

Choroidal vasculature imaging with laser Doppler holography

The choroid is a highly vascularized tissue supplying the retinal pigment epithelium and photoreceptors. Its implication in retinal diseases is gaining increasing interest. However, investigating the anatomy and flow of the choroid remains challenging. Here we show that laser Doppler holography provides high-contrast imaging of choroidal vessels in humans, with a spatial resolution comparable to state-of-the-art indocyanine green angiography and optical coherence tomography. Additionally, laser Doppler holography contributes to sort out choroidal arteries and veins by using a power Doppler spectral analysis. We thus demonstrate the potential of laser Doppler holography to improve our understanding of the anatomy and flow of the choroidal vascular network.

[A giant sacral chordoma resection and reconstruction with a gluteal perforator flap, a case report and literature review]

BACKGROUND

Sacral chordomas are rare primary bone tumors and represent more than half of all primary malignant sacral tumors. Surgical resection is the only treatment with close to 50% of remission at 10 years, with or without radiotherapy. This tissue removal can be very extensive and morbid, particularly for evolved tumors. The reconstruction mostly uses myocutaneous flaps, notably the gluteus maximus flap and the latissimus dorsi flap, increasing morbidity of the surgical procedure. To avoid a muscular sacrifice and reduce the post-surgical morbidity, we describe the case of a patient who underwent a giant sacral chordoma resection and a reconstruction with a superior gluteal artery perforator flap.

CASE REPORT

A 57-y.o. patient with a voluminous sacral chordoma had undergone a partial sacrectomy and abdomino-perineal resection. Firstly, a laparoscopy was realized to create a colostomy, to dissect an omental flap and to prepare the monobloc resection. In a prone position, the resection of the tumor was achieved and a de-epithelialized superior gluteal artery perforator flap was performed to fill the space and to support pelvic organs.

CONCLUSION

For resections of sacral chordomas, coelioscopy has considerably reduced the surgical morbidity. However, the majority of reconstructions use myocutaneous flaps, specifically gluteus maximus and latissimus dorsi, which their postural function is considerable. Muscular sacrifice can lead to functional impotence with difficulty walking and standing up and run contrary to the diminution morbidity initiated by oncologic surgeons.

In vivo laser Doppler holography of the human retina

The eye offers a unique opportunity for the non-invasive exploration of cardiovascular diseases. Optical angiography in the retina requires sensitive measurements, which hinders conventional full-field laser Doppler imaging schemes. To overcome this limitation, we used digital holography to perform laser Doppler perfusion imaging of human retina with near-infrared light. Two imaging channels with a slow and a fast CMOS camera were used simultaneously for real-time narrowband measurements, and offline wideband measurements, respectively. The beat frequency spectrum of optical interferograms recorded with the fast (up to 75 kHz) CMOS camera was analyzed by short-time Fourier transformation. Power Doppler images drawn from the Doppler power spectrum density qualitatively revealed blood flow in retinal vessels over 512 × 512 pixels covering 2.4 × 2.4 mm² on the retina with a temporal resolution down to 1.6 ms. The sensitivity to lateral motion as well as the requirements in terms of sampling frequency are discussed.

Interleukin-32 promotes detachment and activation of human Langerhans cells in a human skin explant model

BACKGROUND

Cross-talk between skin keratinocytes (KCs) and Langerhans cells (LCs) plays a fundamental role in the body's first line of immunological defences. However, the mechanism behind the interaction between these two major epidermal cells is unknown. Interleukin (IL)-32 is produced in inflammatory skin disorders. We questioned the role of IL-32 in the epidermis.

OBJECTIVES

We aimed to determine the role of IL-32 produced by KCs on surrounding LCs.

METHODS

We used an ex vivo human explant model from healthy donors and investigated the role of IL-32 on LC activation using imaging, flow cytometry, reverse transcriptase quantitative polymerase chain reaction and small interfering (si)RNA treatment.

RESULTS

Modified vaccinia virus ankara (MVA) infection induced KC death alongside the early production of the proinflammatory cytokine IL-32. We demonstrated that IL-32 produced by MVA-infected KCs induced modest but significant morphological changes in LCs and downregulation of adhesion molecules, such as epithelial cell adhesion molecule and very late antigen-4, and CXCL10 production. The treatment of KCs with IL-32-specific siRNA, and anti-IL-32 blocking antibody significantly inhibited LC activation, demonstrating the role of IL-32 in LC activation. We also found that some Toll-like receptor ligands induced a very high level of IL-32 production by KCs, which initiated LC activation.

CONCLUSIONS

We propose, for the first time, that IL-32 is a molecular link between KCs and LCs in healthy skin, provoking LC migration from the epidermis to the dermis prior to their migration to the draining lymph nodes.

Design, characterization and in vivo performance of synthetic 2 mm-diameter vessel grafts made of PVA-gelatin blends

Since the development of the first vascular grafts, fabrication of vessel replacements with diameters smaller than 6 mm remains a challenge. The present work aimed to develop PVA (poly (vinyl alcohol))-gelatin hybrids as tubes suitable for replacement of very small vessels and to evaluate their performance using a rat abdominal aorta interposition model. PVA-gelatin hybrid tubes with internal and external diameters of 1.4 mm and 1.8 mm, respectively, composed of 4 different gelatin ratios were prepared using a one-step strategy with both chemical and physical crosslinking. By 3D Time of Flight MRI, Doppler-Ultrasound, Computed Tomography angiography and histology, we demonstrated good patency rates with the 1% gelatin composition until the end of the study at 3 months (50% compared to 0% of PVA control grafts). A reduction of the patency rate during the time of implantation suggested some loss of properties of the hybrid material in vivo, further confirmed by mechanical evaluation until one year. In particular, stiffening and reduction of compliance of the PVA-gelatin grafts was demonstrated, which might explain the observed long-term changes in patency rate. These encouraging results confirm the potential of PVA-gelatin hybrids as ready-to-use vascular grafts for very small vessel replacement.