Local burn versus local cold induced acute effects on in vivo microcirculation and histomorphology of the human skin.

BACKGROUND: The impact of burns and colds on human skin microcirculation and histomorphology has not been compared as yet. Reflectance confocal microscopy (RCM) enables in vivo insight in human skin on cellular and subcellular levels. We evaluated analogies and differences of thermal injuries on microcirculation and histomorphology in vivo using RCM. METHODS: Local superficial burn (6 female, 4 male; aged 28.4 ± 2.9 years, burn group) versus superficial cold (4 female, 6 male; aged 30.4 ± 5.2 years, cold group) was induced on the dorsum of the hand in an experimental immersion hand model. In vivo RCM was performed prior (control), immediately (t1) and 15 minutes (t2) following thermal injury to evaluate: Individual blood cell flow (IBCF), functional capillary density (FCD), epidermal thickness (ET), and granular cell size (GCS). RESULTS: In the burn group, IBCF was increased at t1 (78.02 ± 2.60/min) and remained elevated at t2 (84.16 ± 3.04/min). In the cold group, IBCF decreased at t1 (12.62 ± 2.12 min) and increased at t2 (74.24 ± 3.14/min, P < 0.05) compared to the controls (58.23 ± 3.21/min). FCD was 6.74 ± 0.52/mm(2) in controls and increased at both t1 (7.82 ± 0.72/mm(2)) and t2 (8.02 ± 0.81/mm(2)) in the burn group. In the cold group, FCD decreased at t1 (2.60 ± 0.42/mm(2)) and increased at t2 (7.92 ± 0.44/mm(2), P < 0.05). ET increased at both t1 (43.12 ± 4.08 µm, P > 0.05) and t2 (47.26 ± 4.72 µm, P < 0.05) in the burn group. In the cold group, ET decreased at t1 (39.92 ± 3.14 µm, P > 0.05) and increased at t2 (44.72 ± 4.06 µm, P < 0.05) compared to the controls (41.26 ± 3.82 µm). Control GCS was 726.9 ± 59.4 µm(2) and increased at both t1 (739.8 ± 69.8 µm(2), P > 0.05) and t2 (762.6 ± 71.4 µm(2), P < 0.05) in the burn group. In the cold group, GCS decreased at t1 (712.4 ± 53.8 µm(2), P > 0.05) and increased at t2 (742.6 ± 64.8 µm(2), P < 0.05). CONCLUSIONS: Superficial burn induces more cellular destruction and cold leads to huge fluctuation in tissue perfusion, however, with moderate impact on histomorphology. The effect on dermal capillaries suggests a selective neural control and cold injuries might down-regulate this system, much more than burns can activate it.

In vivo comparison of microcirculation and histomorphology of two different flap donor sites.

BACKGROUND: In soft tissue reconstruction surgery using free flaps, different donor sites from various anatomical regions should be considered. Local microperfusion and histomorphology at these donor sites are often neglected during planning and operation of free tissue transfers. The aim of this in vivo study was to evaluate the microperfusion and, simultaneously, the tissue morphology of two potential free fasciocutaneous flap donor sites on the upper and lower extremity. METHODS: In 23 healthy nonsmoking individuals (aged 30 ± 8.4 years), potential free-flap donor sites for the radial forearm flap (RFF) and the anterolateral thigh flap (ALTF) were investigated using high-resolution in vivo Reflectance-Mode-Confocal-Microscopy (Vivascope 1500, Lucid, Rochester, NY). The following parameters were evaluated: quantitative blood-cell flow; density of functional dermal capillaries; minimal epidermal thickness, and viable thickness of the epidermis. RESULTS: The quantitative blood-cell flow was higher in the RFF donor site (62 ± 3.1 cells/min) compared with the ALTF donor site (51 ± 2.4 cells/min, P < 0.05). The density of functional dermal capillaries at the RFF donor site was higher than at the ALTF donor site (38 ± 3 vs. 22 ± 2.2 capillaries/mm(2) , P < 0.05). The minimal epidermal thickness was thinner at the RFF donor site compared with the ALTF donor site (44 ± 2.9 vs. 55 ± 3.8 µm, P < 0.05). The viable thickness of the epidermis of the RFF region was thinner compared with the region of the ALTF (31 ± 2.1 vs. 42 ± 2.7 µm, P < 0.05). CONCLUSION: For the first time, significant differences in the in vivo microperfusion and histomorphology could be shown when comparing two different free-flap donor sites. The correlation to flap failure needs to be substantiated in further systematic trials.

Percutaneous collagen induction therapy: an alternative treatment for burn scars.

OBJECTIVE: This study aims to evaluate percutaneous collagen induction (PCI) in post-burn scarring. BACKGROUND: Patients with scarring after burn frequently request help in improving the aesthetic appearance of their residual cicatricial deformity. Their scars are generally treated by tissue transfer, W- and Z-plasties, flaps, cortisone injections or ablative procedures that injure or destroy the epidermis and its basement membrane and subsequently lead to fibrosis of the papillary dermis. The ideal treatment would be to preserve the epidermis and promote normal collagen and elastin formation in the dermis. PATIENTS: A total of 16 consecutive patients (average age: 37+/-15.5 years, average body mass index (BMI): 25.7) in Germany with post-burn scarring. INTERVENTION: PCI using the Medical Roll-CIT (Vivida, Cape Town, South Africa). This device was designed to multiply-puncture the skin to the level of the dermal scar to institute remodelling. Patients were prepared with topical vitamin A and C cosmetic creams for a minimum of 4 weeks preoperatively to maximise collagen stimulation. OUTCOME MEASURES: The outcome was measured rating (visual analogue scale (VAS) and Vancouver Scar Scale (VSS)), histological specimen 12 months after intervention. RESULTS: On average, patients rated their improvement as a mean of 80% better (+/-15.5) than before treatment. Histologic examination revealed considerable increase in collagen and elastin deposition 12 months postoperatively. The epidermis demonstrated 45% thickening of stratum spinosum and normal rete ridges as well as the normalisation of the collagen/elastin matrix in the reticular dermis at 1 year postoperatively. CONCLUSIONS: This pilot study shows that PCI appears to be a safe method for treating post-burn scarring without destroying the epidermis. The procedure can be repeated safely and is also applicable in regions where laser treatments and deep peels are of limited use. However, it is necessary to initiate an efficacy trial to prove the data of this pilot study.

Histometric and histomorphologic comparison of combustion and ambustion using in vivo reflectance-confocal microscopy.

BACKGROUND: When combustion and ambustion induce a superficial injury, they are summarized as superficial burns, regardless of the underlying cause. Reflectance-confocal microscopy (RCM) allows noninvasive imaging of the human skin on morphological features. We hypothesized that combustion and ambustion have different histomorphological effects on the human skin. METHODS: Superficial burns caused by combustion (CO-group, five females, three males; aged 26.8 +/- 14.2 years) and caused by ambustion (AM-group, four females, four males; aged 28.1 +/- 13.8 years) were evaluated 24 h after injury. The following parameters were obtained using RCM on injured and noninjured (control) site: horny layer thickness, epidermal thickness, granular cell size, basal layer thickness. RESULTS: Compared with the controls (12.8 +/- 2.5 microm), horny layer thickness decreased significantly to 10.6 +/- 2.1 microm in the CO-group, whereas it increased significantly to 17.8 +/- 2.8 microm in the AM-group. The epidermal thickness did not differ significantly in CO-group (47.9 +/- 2.1 microm) and AM-group (49.0 +/- 3.1 microm), however, both increased significantly compared with the controls (42.7 +/- 1.6 microm). The basal layer thickness increased more in AM-group (17.0 +/- 1.2 microm) compared to CO-group (15.4 +/- 1.1 microm). Both differed significantly compared with their controls (13.9 +/- 0.9 microm). The granular cell size increased significantly in both groups compared to the controls (721 +/- 42 microm), however, a significantly higher increase was observed in CO-group compared to AM-group (871 +/- 55 microm vs. 831 +/- 51 microm). CONCLUSIONS: RCM evaluates significant histomorphological differences in superficial burns caused by combustion and ambustion. The term "superficial burn" should consider the underlying cause and thus supplemented by the term "combustion" or "ambustion."

Insight in human skin microcirculation using in vivo reflectance-mode confocal laser scanning microscopy.

Reflectance-mode confocal laser scanning microscopy allows in vivo imaging of the human skin. We hypothesized that this high-resolution technique enables observation of dynamic changes of the cutaneous microcirculation. Twenty-two volunteers were randomly divided in two groups. Group 1 was exposed to local heating and group 2 to local cold stress. Confocal microscopy was performed prior t (0) (control), directly t (1) and 5 min t (2) after local temperature changes to evaluate quantitative blood cell flow, capillary loop diameter, and density of dermal capillaries. In group 1, blood flow increased at t (1) (75.82 +/- 2.86/min) and further at t (2) (84.09 +/- 3.39/min) compared to the control (61.09 +/- 3.21/min). The control capillary size was 9.59 +/- 0.25 microm, increased to 11.16 +/- 0.21 microm (t (1)) and 11.57 +/- 0.24 microm (t (2)). The dermal capillary density increased in t (1) (7.26 +/- 0.76/mm(2)) and t (2) (8.16 +/- 0.52/mm(2)), compared to the control (7.04 +/- 0.62/mm(2)). In group 2, blood flow decreased at t (1) (41.73 +/- 2.61/min) and increased at t (2) (83.27 +/- 3.29/min) compared to the control (60.73 +/- 2.90/min). The control capillary size was 9.55 +/- 0.25 microm, decreased at t (1) (7.78 +/- 0.26 microm) and increased at t (2) (11.38 +/- 0.26 microm). Capillary density decreased at t (1) (5.01 +/- 0.49/mm(2)) and increased at t (2) (7.28 +/- 0.53/mm(2)) compared to the control (7.01 +/- 0.52/mm(2)). Confocal microscopy is a sensitive and noninvasive imaging tool for characterizing and quantifying dynamic changes of cutaneous microcirculation on a histomorphological level.

Insight in microcirculation and histomorphology during burn shock treatment using in vivo confocal-laser-scanning microscopy.

PURPOSE: Microcirculatory disturbances are well known during shock; however, the accompanied histomorphological alterations are widely unknown. We used high resolution confocal-laser-scanning microscopy for the evaluation of microcirculation and histomorphology during Burn Shock treatment. METHODS: Confocal-laser-scanning microscopy was performed in 10 burn shock patients (4 women, 6 men; aged 40.6 +/- 11.4 years, burn extent >20% body surface area) initially and 24 hours after shock resuscitation. Ten matched hemodynamic stable burn intensive care unit patients served as controls. The following parameters were evaluated: quantitative blood cell flow, cell size of the granular layer, basal layer thickness, and epidermal thickness. RESULTS: Quantitative blood cell flow in controls was 62.45 +/- 3.39 cells per minute. Burn shock significantly reduced blood cell flow to 37.27 +/- 3.64 cells per minute; fluid resuscitation effectively restored baseline blood flow (65.18 +/- 3.76 cells per minute) after 24 hours. Granular cell size was 793.61 +/- 41.58 microm(2) in controls vs 644.27 +/- 42.96 microm(2) during burn shock. Post resuscitation granular cell size measured 932.74 +/- 38.83 microm(2). Basal layer thickness was 14.84 +/- 0.59 microm in controls, 13.26 +/- 0.54 microm in burn patients at admission and before resuscitation, and 17.50 +/- 0.46 microm after resuscitation. Epidermal thickness in control patients was 49.60 +/- 2.36 microm, 37.83 +/- 2.47 microm in burn patients at admission and 69.50 +/- 3.18 microm after resuscitation. CONCLUSIONS: Confocal-laser-scanning microscopy provides a noninvasive tool for simultaneous evaluation of microcirculation and tissue histomorphology. It may help to assess the adequacy of and response to resuscitation of burn patients early after trauma.

Assessment of microcirculatory influence on cellular morphology in human burn wound healing using reflectance-mode-confocal microscopy.

Previous studies have assessed the effects of changes in microcirculation on wound healing; however, the influence of microcirculation on tissue histomorphology remains widely unknown. Reflectance-mode-confocal microscopy (RMCM) enables in vivo tissue observation on a cellular level. We present RMCM data evaluating the local microcirculation and assess the influence on histomorphology during burn healing. RMCM was performed in 12 patients (aged; 36.2+/-14.2 years, maximum-burn-extent: 4% total body surface area) at times 12, 36, and 72 hours after a superficial burn. The following parameters were assessed: quantitative blood-cell-flow (cbf), epidermal thickness (Emin), basal-layer thickness (tbl), and granular cell-size (Agran). Cbf was found to be 54+/-3.6 cells/minutes (control), increased to 91+/-3.6 cells/minutes (p<0.05) 12 hours postburn; decreased to 71+/-6.1 cells/minutes (p<0.05) (36 hours), and to 63+/-2.3 cells/minutes (p>0.05) 72 hours postburn. Emin was 43.74+/-3.87 mum (control), increased to 51.67+/-4.04 mum (p<0.05) 12 hours, decreased to 48.67+/-3.51 mum (p<0.05) 36 hours, and to 45.33+/-3.21 mum (p>0.05) at 72 hours postburn. Tbl was 14.17+/-0.6 mum (control), increased to 16.93+/-1.15 mum (p<0.05) 12 hours, decreased to 15.93+/-1.20 mum (p<0.05) 32 hours, and to 15.00+/-0.85 mum (p>0.05) 72 hours postburn. Agran was 718+/-56.20 mum(2) (control), increased to 901+/-66.02 mum(2) (p<0.05) 12 hours, decreased to 826+/-56.86 mum(2) 36 hours, and 766+/-65.06 mum(2) at 72 hours postburn. RMCM enables in vivo observation of wound microcirculation and allows direct assessment of vascular effects on cutaneous histomorphology during the healing course of superficial burns.

In vivo evaluation of histomorphological alterations in first-degree burn injuries by means of confocal-laser-scanning microscopy-more than "virtual histology?".

There are various approaches to the treatment of superficial burns. No modality exists to date for determining treatment efficiency on morphological features. We review the first application of high-resolution in vivo confocal-laser-scanning microscopy (CLSM) to the evaluation of superficial burns on a histomorphological level. Sixteen patients (6 women, 10 men; 34.5 +/- 16.2 years) with first-degree thermal contact injuries to a maximum extent of 1% of the body surface were enrolled into the study. CLSM was performed with the Vivascope 1500 (Lucid Inc., Rochester, NY) 24 hours after injury. The following parameters were assessed: cell size of the granular layer, thickness of the basal layer, minimal thickness of the epidermis, and diameter of capillary loops. Compared with the control sites 24 hours postburn, the minimal thickness of the epidermis increased on average by approximately 11% (P = .01; t-test); the thickness of the basal layer increased about 7% (P = .008; t-test); the diameter of capillary loops increased approximately by 17% (P = 0.003; t-test); and the cell size of the granular layer increased about 8% (P = .009; Wilcoxon's test). In vivo CLSM allows characterizing and quantifying histomorphological alterations in superficial burns. CLSM could be helpful in assessing the effects of various treatment approaches for superficial burns on a histomorphological level.

Reflectance confocal-laser-scanning microscopy in vivo assessments of cigarette-induced dynamic alterations of cutaneous microcirculation on histomorphological level.

OBJECTIVE: Until now, high resolution reflectance confocal-laser-scanning microscopy (CLSM) was used for observation of cutaneous morphology in vivo and in real time. We hypothesized that CLSM also allows observation of dynamic processes of cutaneous microcirculation. METHODS: Reflectance CLSM (Vivascope1500; Lucid, Rochester, NY) was performed in 24 young male habitual smokers (23 years, range: 19-26, body mass index 23.9 +/- 4.04) with relatively limited cigarette exposure (mean: 3.1 +/- 2.4 pack-years). Eight matched nonsmokers served as controls. The quantitative blood cell flow and the diameter of capillary loops were determined prior (baseline), during, as well as 5 and 10 min after smoking. RESULTS: Baseline value for blood cell flow was 55.50 +/- 2.33 cells/min, and decreased over 45% during smoking (30.43 +/- 3.76/min; P = 0.02). They were still 22% lower (43.33 +/- 2.45/min; P = 0.01) 5 min after smoking and exceeded baseline values 10 min after smoking by 13% (63.00 +/- 3.10/min; P > 0.05). The baseline values for capillary loop diameter (9.03 +/- 0.22 microm) decreased by 21% (7.18 +/- 0.28 microm; P = 0.03) during smoking, remained about 9% (8.23 +/- 0.18 microm; P = 0.01) lower 5 min after smoking and exceeded baseline values insignificantly by 4% (9.38 +/- 0.28 microm; P > 0.05) 10 min after smoking. There were no significant differences to the controls. CONCLUSION: Reflectance CLSM enables qualitative and quantitative observation of dynamic processes of cutaneous microcirculation on histomorphological level.