A one-time pneumatic jet-injection of 5-fluorouracil and triamcinolone acetonide for treatment of hypertrophic scars-A blinded randomized controlled trial

BACKGROUND

Patients with hypertrophic scars (HTS) risk reduced quality of life due to itching, pain, poor cosmesis, and restriction of movement. Despite good clinical efficacy, patients are often reluctant to undergo repeated needle injections due to pain or needle phobia.

OBJECTIVES

To evaluate the applicability of needle-free pneumatic jet injection (PJI) and assess changes in hypertrophic scars following a single PJI treatment with 5-fluorouracil (5-FU) and triamcinolone acetonide (TAC).

METHODS

Twenty patients completed this blinded, randomized, controlled, split-scar trial. The intervention side of the HTS received a one-time treatment with PJIs containing a mixture of TAC + 5-FU injected at 5 mm intervals (mean 7 PJI per HTS); the control side received no treatment. Assessments were made at baseline and 4 weeks posttreatment. Outcome measures included change in (1) Vancouver Scar Scale (VSS) total score and subscores, (2) scar volume and surface area assessed by three-dimensional imaging, (3) skin microarchitecture measured by optical-coherence tomography (OCT), (4) photo-assessed scar cosmesis (0-100), (5) patient-reported pain and satisfaction (0-10), and (6) depiction of drug biodistribution after PJI.

RESULTS

PJI with TAC + 5-FU significantly decreased both HTS height (-1 VSS; p = 0.01) and pliability (-1 VSS; p < 0.01) with a nonstatistically significant reduction of -1 in total VSS score (0 in control; p = 0.09). On 3D imaging, a 33% decrease in scar volume (p = 0.016) and a 37% decrease in surface area (p = 0.008) was observed. OCT indicated trends towards smoother scar surface (Ra 11.1-10.3; p = 0.61), normalized dermal microarchitecture (attenuation coefficient: 1.52-1.68; p = 0.44), and a reduction in blood flow between 9% and 17% (p = 0.50-0.79). Despite advances in VSS subscores and OCT, no improved photo-assessed cosmesis was found (-3.2 treatment vs. -1.4 control; p = 0.265). Patient-reported pain was low (2/10) and 90% of the patients that had previously received needle injections preferred PJI to needle injection. Depositions of TAC + FU were imaged reaching deep into the scar at levels corresponding to the reticular dermis.

CONCLUSION

A single PJI injection containing 5-FU and TAC can significantly improve the height and pliability of HTS. PJI is favored by the patients and may serve as a complement to conventional needle injections, especially for patients with needle phobia.

Attenuation corrected-optical coherence tomography for quantitative assessment of skin wound healing and scar morphology

Imaging the structural modifications of underlying tissues is vital to monitor wound healing. Optical coherence tomography (OCT) images high-resolution sub-surface information, but suffers a loss of intensity with depth, limiting quantification. Hence correcting the attenuation loss is important. We performed swept source-OCT of full-thickness excision wounds for 300 days in mice skin. We used single-scatter attenuation models to determine and correct the attenuation loss in the images. The phantom studies established the correspondence of corrected-OCT intensity (reflectivity) with matrix density and hydration. We histologically validated the corrected-OCT and measured the wound healing rate. We noted two distinct phases of healing-rapid and steady-state. We also detected two compartments in normal scars using corrected OCT that otherwise were not visible in the OCT scans. The OCT reflectivity in the scar compartments corresponded to distinct cell populations, mechanical properties and composition. OCT reflectivity has potential applications in evaluating the therapeutic efficacy of healing and characterizing scars.

Investigation of optical attenuation imaging using optical coherence tomography for monitoring of scars undergoing fractional laser treatment

We demonstrate the use of the near-infrared attenuation coefficient, measured using optical coherence tomography (OCT), in longitudinal assessment of hypertrophic burn scars undergoing fractional laser treatment. The measurement method incorporates blood vessel detection by speckle decorrelation and masking, and a robust regression estimator to produce 2D en face parametric images of the attenuation coefficient of the dermis. Through reliable co-location of the field of view across pre- and post-treatment imaging sessions, the study was able to quantify changes in the attenuation coefficient of the dermis over a period of ∼20 weeks in seven patients. Minimal variation was observed in the mean attenuation coefficient of normal skin and control (untreated) mature scars, as expected. However, a significant decrease (13 ± 5%, mean ± standard deviation) was observed in the treated mature scars, resulting in a greater distinction from normal skin in response to localized damage from the laser treatment. By contrast, we observed an increase in the mean attenuation coefficient of treated (31 ± 27%) and control (27 ± 20%) immature scars, with numerical values incrementally approaching normal skin as the healing progressed. This pilot study supports conducting a more extensive investigation of OCT attenuation imaging for quantitative longitudinal monitoring of scars. En face 2D OCT attenuation coefficient map of a treated immature scar derived from the pre-treatment (top) and the post-treatment (bottom) scans. (Vasculature (black) is masked out.) The scale bars are 0.5 mm.

Classifying murine glomerulonephritis using optical coherence tomography and optical coherence elastography

Acute glomerulonephritis caused by antiglomerular basement membrane marked by high mortality. The primary reason for this is delayed diagnosis via blood examination, urine analysis, tissue biopsy, or ultrasound and X-ray computed tomography imaging. Blood, urine, and tissue-based diagnoses can be time consuming, while ultrasound and CT imaging have relatively low spatial resolution, with reduced sensitivity. Optical coherence tomography is a noninvasive and high-resolution imaging technique that provides superior spatial resolution (micrometer scale) as compared to ultrasound and CT. Changes in tissue properties can be detected based on the optical metrics analyzed from the OCT signals, such as optical attenuation and speckle variance. Furthermore, OCT does not rely on ionizing radiation as with CT imaging. In addition to structural changes, the elasticity of the kidney can significantly change due to nephritis. In this work, OCT has been utilized to quantify the difference in tissue properties between healthy and nephritic murine kidneys. Although OCT imaging could identify the diseased tissue, its classification accuracy is clinically inadequate. By combining optical metrics with elasticity, the classification accuracy improves from 76% to 95%. These results show that OCT combined with OCE can be a powerful tool for identifying and classifying nephritis. Therefore, the OCT/OCE method could potentially be used as a minimally invasive tool for longitudinal studies during the progression and therapy of glomerulonephritis as well as complement and, perhaps, substitute highly invasive tissue biopsies. Elastic-wave propagation in mouse healthy and nephritic kidneys.