Ahmet Ali Altintas

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.

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 μm) decreased by 21% (7.18 ± 0.28 μm; P = 0.03) during smoking, remained about 9% (8.23 ± 0.18 μm; P = 0.01) lower 5 min after smoking and exceeded baseline values insignificantly by 4% (9.38 ± 0.28 μm; 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. Microsc. Res. Tech., 2009.

To heal or not to heal: predictive value of in vivo reflectance-mode confocal microscopy in assessing healing course of human burn wounds.

The purpose of this study was to assess if the healing course of burn wounds of indeterminate depth can be predicted based on serial in vivo reflectance-mode confocal microscopy (RMCM) analysis. Twenty-four patients (mean age, 33.1 ± 11.4 years; mean burn size: 6% TBSA) were investigated at 12, 36, and 72 hours after burn of indeterminate depth and retrospectively grouped into healing group (HG: 16 patients) and nonhealing group (NHG: eight patients). Noninjured skin served as controls. The following parameters were assessed: quantitative blood cell flow (BCF), basal layer thickness (BLT), and inflammatory cells. At 12 hours postburn, BCF increased to 101.67 ± 7.64 cells/min in HG vs 85 ± 50 cells/min in NHG compared with controls (56.5 ± 2.3 cells/min). At 36 and 72 hours, BCF increased to 115 ± 10 cells/min and 125 ± 50 cells/min in HG vs decreased to 80 ± 5 cell/min and 75 ± 5 cells/min in NHG (P < .05). At 12 hours postburn, BLT increased to 19.43 ± 0.93 &mgr;m in HG vs 29 ± 1 &mgr;m in NHG compared with controls (15.40 ± 0.60 &mgr;m, P < .05). In HG, further gradual increase of BLT to 20 ± 1 &mgr;m (36 hours) and 21 ± 1 &mgr;m (72 hours) was observed, whereas BLT was destroyed after 36 hours in NHG. Qualitative assessment found insignificant amount of IC in controls and low amount in HG until 72 hours postburn, whereas progressive increase in IC from low amount (12 hours) to numerous (36 hours) and massive (72 hours) was observed in NHG. RMCM enables simultaneous evaluation of microcirculation, histomorphology, and inflammatory cell trafficking in burn wounds. RMCM may help to predict whether burns of indeterminate depth have the potential to heal and can be a valuable tool to clinicians to guide early therapeutic decision-making process in burn patients.

In vivo reflectance-mode confocal microscopy provides insights in human skin microcirculation and histomorphology

PURPOSE Various approaches are used to study microcirculation, however, no modality evaluates microcirculation and histomorphology on cellular levels. We hypothesized that reflectance-mode confocal microscopy (RCM) enables simultaneous evaluation in vivo of both microcirculation and histomorphology. PRINCIPALS The forearm of 20 volunteers was exposed to either local heat stress (HS-group), or to local cold stress (CS-group). RCM was performed prior and after temperature stress to evaluate quantitative blood-cell flow, capillary loop diameter, granular cell size, and basal layer thickness. RESULTS In the HS-group, we observed significant increase in capillary loop diameter and increased blood-cell flow after heat stress. In the CS-group, significant decreases of capillary loop diameter and in blood-cell flow were determined following cold stress. Granular cell size and basal layer thickness differed insignificantly prior and after local temperature stress. CONCLUSIONS RCM provides real-time and in vivo high resolution imaging of temperature-dependent changes in the human skin microcirculation and histomorphology on cellular levels.

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 μm (control), increased to 51.67±4.04 μm (p<0.05) 12 hours, decreased to 48.67±3.51 μm (p<0.05) 36 hours, and to 45.33±3.21 μm (p>0.05) at 72 hours postburn. Tbl was 14.17±0.6 μm (control), increased to 16.93±1.15 μm (p<0.05) 12 hours, decreased to 15.93±1.20 μm (p<0.05) 32 hours, and to 15.00±0.85 μm (p>0.05) 72 hours postburn. Agran was 718±56.20 μm2 (control), increased to 901±66.02 μm2 (p<0.05) 12 hours, decreased to 826±56.86 μm2 36 hours, and 766±65.06 μm2 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.

Is superficial burn caused by ultraviolet radiation (sunburn) comparable to superficial burn caused by heat – a histomorphological comparison by in vivo Reflectance-Mode-Confocal Microscopy

Background  Regardless of the underlying cause, both sunburn and superficial thermal injuries are classified as first‐degree burns, since data on morphological differences are scarce. Reflectance‐Mode‐Confocal Microscopy (RMCM) enables high‐resolution non‐invasive investigation of the human skin.

Acute effects of splint immobilization of the forearm on in vivo microcirculation and histomorphology of the human skin

BACKGROUND: Splint immobilization of the forearm is often performed in clinical practice. Previous studies investigated the effect of immobilization on bone, cartilage, muscle, and tendon, however, the acute effects on human skin microcirculation and histomorphology remains elusive. METHODS: In 12 healthy, nonsmoking individuals (aged 29.7 ± 9.1 years) a randomly selected forearm was immobilized by splinting for 72 h, whereas the other forearm served as control. In vivo Reflectance‐Mode Confocal‐Microscopy (RMCM) was performed prior (baseline value) and postimmobilization to evaluate: quantitative blood cell flow; density of functional dermal capillaries; epidermal thickness; and granular cell size. RESULTS: At 72h forearm immobilization, quantitative blood cell flow was significantly reduced (42.86 ± 3.68 cells/min) compared to the control blood flow (53.11 ± 3.68 cells/min, P < 0.05) and dermal capillaries indicates less functional density (5.73 ± 0.63 capillaries/mm2) compared to the controls (7.04 ± 0.81 capillaries/mm2, P < 0.05). Histometric assessment reveals significantly thinner epidermis following immobilization compared to the control site (40.02 ± 2.91 vs. 46.64±3.09 µm, P < 0.05). Granular cell size was significantly altered at 72 h splinting (730.1 ± 42.53 µm2) compared to the control cell size at 770.2 ± 38.21 µm2. Comparison of baseline values of both forearms indicate statistically insignificance (P > 0.05) for each parameter. CONCLUSION: At 72 h splint immobilization, for the first time, significant adaptive mechanisms were evaluated on human skin microcirculation and histomorphology using in vivo RMCM. These adaptations may be considered as an incipient atrophy of the human skin. Long‐term effects of immobilization including the regenerative potential should be evaluated in further RMCM studies. Microsc. Res. Tech. 77:99–103, 2014.

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

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.

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 μm), horny layer thickness decreased significantly to 10.6 ± 2.1 μm in the CO‐group, whereas it increased significantly to 17.8 ± 2.8 μm in the AM‐group. The epidermal thickness did not differ significantly in CO‐group (47.9 ± 2.1 μm) and AM‐group (49.0 ± 3.1 μm), however, both increased significantly compared with the controls (42.7 ± 1.6 μm). The basal layer thickness increased more in AM‐group (17.0 ± 1.2 μm) compared to CO‐group (15.4 ± 1.1 μm). Both differed significantly compared with their controls (13.9 ± 0.9 μm). The granular cell size increased significantly in both groups ompared to the controls (721 ± 42 μm), however, a significantly higher increase was observed in CO‐group compared to AM‐group (871 ± 55 μm vs. 831 ± 51 μm). 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.” Microsc. Res. Tech., 2010.