Real-time imaging of suction blistering in human skin using optical coherence tomography

Abstract

Separation of skin epidermis from the dermis by suction blistering has been used with high success rate for autologous skin epidermal grafting in burns, chronic wounds and vitiligo transplantation treatment. Although commercial products that achieve epidermal grafting by suction blistering are presently available, there is still limited knowledge and understanding on the dynamic process of epidermal-dermal separation during suction blistering. In this report we integrated a suction system to an Optical Coherence Tomography (OCT) which allowed for the first time, real-time imaging of the suction blistering process in human skin. We describe in this report the evolution of a suction blister where the growth is modeled with a Boltzmann sigmoid function. We further investigated the relationship between onset and steady-state blister times, blister growth rate, applied suction pressure and applied local skin temperature. Our results show that while the blister time is inversely proportional to the applied suction pressure, the relationship between the blister time and the applied temperature is described by an exponential decay.

Keywords: (110.4500) Optical coherence tomography; (170.1870) Dermatology; (170.3880) Medical and biological imaging; (170.6935) Tissue characterization.

Fig. 1

Experimental setup showing the OCT system, home-built OCT-suction coupler and the skin sample.

Fig. 2

Different phases of the blister formation process. During the first 15 minutes skin doming was observed (A to C). At 21 minutes the first cleft is observed (D) which grew in size (D to F). A steady-state phase is achieved at 45 minutes (G). A movie of the blister formation is shown in I with a speed factor of ~1000 × (see Visualization 1).

Fig. 3

Initiation of microblisters from multiple sites (yellow arrows) and eventual mergence at 7 min and 11 min, respectively.

Fig. 4

A: Typical blister growth curves showing normalized blister area evolution for different pressures at ~21°C. B: Dependence of the onset and steady-state blister times, t₁₀ (black squares) and t₉₀ (red circles), respectively, on the suction pressure at ~21°C. The blister growth rate (blue triangles) shows good fit with an exponential function (blue line) against the suction pressure. For clarity, only positive or negative error bars are shown for the data.

Fig. 5

A: Typical blister growth curves showing normalized blister area evolution for different temperatures using a suction pressure of 600 mmHg. B: Dependence of the onset and steady-state blister times, t₁₀ (black squares) and t₉₀ (red circles), respectively, on the local skin temperature using a suction pressure of 600 mmHg. The blister times fit with exponential decay curves (black and red lines). The blister growth rate (blue triangles) shows positive linear relationship with skin temperature.