Skin graft vascular maturation and remodeling: a multifractal approach to morphological quantification

Effects of therapeutic ultrasound and paraffin with or without vacuum massage on biomechanical properties of grafted skin after burn: a randomized controlled trial

OBJECTIVE

This study aimed to compare the effects of therapeutic ultrasound and paraffin with or without vacuum massage on the biomechanical properties of grafted skin after a burn.

METHODS

A total of 44 patients with deep second- and third-degree burns, with a mean age of 35.89 (±11.53) years, who visited the Hospital Burn Unity, were included in the study. The therapeutic interventions were randomly defined by drawing lots, with a crossover design (crossover), and a minimum interval of 7 days (washout) between interventions. Skin biomechanical parameters such as distensibility (R0) and viscoelasticity (R6) were noninvasively evaluated by Cutometer before and after 0, 10, 20, and 30 min of intervention with therapeutic ultrasound and paraffin alone, as well as associated with negative pressure therapy of the skin (vacuum therapy). In this study, all groups showed increased distensibility (R0) in the period immediately after the application of the resources and a progressive reduction in the effects in the consecutive tests. Participants with skin grafts showed a decrease in viscoelasticity (R6) in all groups, except therapeutic paraffin and therapeutic ultrasound and vacuum massage.

CONCLUSION

The biomechanical properties of grafted skin after a burn are altered after therapeutic intervention with ultrasound alone or associated with vacuum massage, such as intervention with paraffin associated with vacuum massage, for both parameters evaluated, skin distensibility (R0) and skin viscoelasticity (R6). However, the same did not occur for the intervention with isolated paraffin. There was no significant difference between the interventions therapeutic ultrasound and therapeutic paraffin.

Objective Skin Quality Assessment after Reconstructive Procedures for Facial Skin Defects

Local random skin flaps and skin grafts are everyday surgical techniques used to reconstruct skin defects. Although their clinical advantages and disadvantages are well known, there are still uncertainties with respect to their long-term results. Hence, the aim of this study was to evaluate outcomes more than one-year post operatively using objective measurement devices. The study included 31 facial defects reconstructed with local random flap, 30 facial defects reconstructed with split-thickness skin grafts (STSGs) and 30 facial defects reconstructed with full-thickness skin grafts (FTSGs). Skin quality was objectively evaluated using MP6 noninvasive probes (Courage + Khazaka GmbH, Cologne, Germany), which measure melanin count, erythema, hydration, sebum, friction and transepidermal water loss. The results showed that there were no significant differences in melanin count, erythema, hydration, sebum level, friction value and transepidermal water loss (TEWL) between the site reconstructed with random local flaps and the same site on the healthy contralateral side of the face. However, both FTSGs and STSGs showed significantly higher levels in terms of TEWL and erythema, whereas the levels of hydration, sebum and friction were significantly lower compared to the healthy contralateral side. Moreover, STSGs resulted in a significant difference in melanin count. These findings imply that the complex pathophysiology of the wound-healing process possibly results in better skin-quality outcomes for random local flaps than skin autografts. Consequently, this suggests that random local flaps should be implemented whenever possible for the reconstruction of facial region defects.

Imaging human skin autograft integration with optical coherence tomography

Background

Skin autografting is a common clinical procedure for reconstructive surgery. Despite its widespread use, very few studies have been conducted to non-invasively evaluate and monitor the vascular and structural features of skin grafts. This study, therefore, aims to demonstrate the potential of optical coherence tomography (OCT) alongside OCT-based angiography (OCTA) to non-invasively image and monitor human skin graft health and integration over time.

Methods

An in-house-built clinical prototype OCT system was used to acquire OCT/OCTA images from patients who underwent split-thickness skin graft surgery following severe burn damage to the skin. The OCT imaging was carried out at multiple locations over multiple time points with a field of view of ~9 mm × 9 mm and a penetration depth of ~1.5 mm. In addition to obtaining high-resolution qualitative images, we also quantitatively measured and compared specific structural and vascular parameters, such as identifiable layer thickness and corresponding vascular area density and diameter.

Results

Two patients (patient #1 and #2) were enrolled for this preliminary study. Vascular and structural features were successfully imaged and measured in the graft tissue and integration layer immediately beneath at different time points. Revascularization, healing, and integration were monitored with patient-specific details. Results of the quantitative image analysis from patient #1 indicated that integration layer thickness 16-day post-surgery was significantly less (~50%) than that of 7-day post-surgery. Additionally, with patient #2, significant growth (~20%) was seen with the vascular area density of both the graft and corresponding integration layer beneath between 6 and 14 days post-surgery.

Conclusions

Our preliminary studies show that OCT/OCTA has clinical potential to image and measure numerous features of human skin graft health and integration in the days and weeks following split-thickness surgery. For the first time, we demonstrate the applicability of non-invasive imaging technology for novel clinical uses that could eventually aid in the betterment of surgical practices and clinical outcomes.

Eczema of recipient and donor skin graft sites: Another example of "Ruocco's immunocompromised district"

A 47-year-old male suffered soft tissue injuries 8 years ago that had been covered by meshed split thickness skin graft. During the last 2 years, he developed a chronic eczema (atopic dermatitis) on both recipient and donor sites on the lower extremities. Eczema on skin graft sites has been described rarely. However, this case is unique since both donor and recipient site were involved. We consider our observation as another example of Ruocco's immunocompromised districts of skin.

A bioimage informatics based reconstruction of breast tumor microvasculature with computational blood flow predictions

Induction of tumor angiogenesis is among the hallmarks of cancer and a driver of metastatic cascade initiation. Recent advances in high-resolution imaging enable highly detailed three-dimensional geometrical representation of the whole-tumor microvascular architecture. This enormous increase in complexity of image-based data necessitates the application of informatics methods for the analysis, mining and reconstruction of these spatial graph data structures. We present a novel methodology that combines ex-vivo high-resolution micro-computed tomography imaging data with a bioimage informatics algorithm to track and reconstruct the whole-tumor vasculature of a human breast cancer model. The reconstructed tumor vascular network is used as an input of a computational model that estimates blood flow in each segment of the tumor microvascular network. This formulation involves a well-established biophysical model and an optimization algorithm that ensures mass balance and detailed monitoring of all the vessels that feed and drain blood from the tumor microvascular network. Perfusion maps for the whole-tumor microvascular network are computed. Morphological and hemodynamic indices from different regions are compared to infer their role in overall tumor perfusion.