Long‐term blood vessel removal with combined laser and topical rapamycin antiangiogenic therapy: Implications for effective port wine stain treatment

Abstract

Background and Objectives: Complete blanching of port wine stain (PWS) birthmarks after laser therapy is rarely achieved for most patients. We postulate that the low therapeutic efficacy or treatment failure is caused by regeneration and revascularization of photocoagulated blood vessels due to angiogenesis associated with the skin's normal wound healing response. Rapamycin (RPM), an antiangiogenic agent, has been demonstrated to inhibit growth of pathological blood vessels. Our objectives were to (1) investigate whether topical RPM can inhibit reperfusion of photocoagulated blood vessels in an animal model and (2) determine the effective RPM concentration required to achieve this objective. Study Design/Materials and Methods: For both laseronly and combined laser and RPM treated animals, blood vessels in the dorsal window chambers implanted on golden Syrian hamsters were photocoagulated with laser pulses. Structural and flow dynamics of blood vessels were documented with color digital photography and laser speckle imaging to evaluate photocoagulation and reperfusion. For the combined treatment group, topical RPM was applied to the epidermal side of the window daily for 14 days after laser exposure. Results: In the laser-only group, 23 out of 24 photocoagulated blood vessels reperfused within 5-14 days. In the combined treatment group with different RPM formulae and concentrations, the overall reperfusion rate of 36% was much lower as compared to the laser-only group. We also found that the reperfusion rate was not linearly proportional to the RPM concentration. Conclusions: With topical RPM application, the frequency of vessel reperfusion was considerably reduced, which implies that combined light and topical antiangiogenic therapy might be a promising approach to improve the treatment efficacy of PWS birthmarks. Lasers Surg.

Optimization of camera exposure durations for multi-exposure speckle imaging of the microcirculation

“…Beyond bench-side physiological research, there are direct implications for prognostic, diagnostic, and intraoperative imaging applications, as speckle imaging of microcirculatory flows is increasingly becoming applied for gauging local and systemic tissue health [8,9]. Consequently, laser speckle flowmetry studies are expanding in dermatological [10][11][12][13][14], ophthalmological [15][16][17], and neurosurgical settings [18][19][20].…”

Successful Treatment of Unilateral Klippel-Trenaunay Syndrome With Pulsed-Dye Laser in a 2-Week Old Infant

“…15,16 Resolution of PWS, as defined by persistent blanching of the lesion, is reported in less than 10%-20% of cases. 12,[17][18][19][20] Early intervention is indicated to prevent the development of hypertrophy and nodularity, which has been shown to increase treatment resistance. 12,21 Thickened PWS lesions at older age have been associated with increased therapeutic failure.…”

The antagonist of the JAK-1/STAT-1 signaling pathway improves the severity of cerulein-stimulated pancreatic injury via inhibition of NF-κB activity

“…The findings thus indicate that the therapeutic strategy for SAP should include the modulation of the JAK-1/ STAT-1, STAT-3 signaling pathway. RPM is a streptomyces derivative that inhibits the mammalian target of the mTOR signaling pathway that is critical for the regulation of cell growth, cell proliferation, cell motility, cell survival (21,22). RPM is widely used as an immunosuppressant in organ transplant recipients and has shown limited toxicities even in immunological disorders (23).…”