Aims: Although therapeutic management of hypertrophic scars and Keloids (HSK) using contact or spray cryosurgery was shown to yield significant improvement or complete regression of HSK, it requires 1-20 treatment sessions. This study was designed to assess the clinical safety and efficacy of an intralesional needle cryoprobe method in the treatment of HSK. Patients & Method: 95 Caucasian patients (51 females; 44 males), ranging in age from 3 to 67 years, with a total of 112 HSKs (chest- 62; auricular and lobular- 26; shoulder- 7; neck- 4; abdomen- 4; breast- 4; nape- 3; arm and forearm- 2) of more than 6 months duration and of diverse causes were included in this study. The 18-month trial evaluated volume reduction of the HSK following a single session of intralesional cryosurgery. Objective (hardness and color) and subjective parameters (pain/tenderness and itchiness/discomfort) were examined on a scale of 0 3 (low score was better). Pre- and post-treatment biopsies were taken for histo-morphometric studies of the collagen fibers included spectral Picrosirius red polarization, fractal analysis and Fast Fourier Transform algorithm orientation index. Thermal behavior measurements using thermocouples were executed in a swine muscle specimens and during clinical treatments to measure the thermal history and injury mechanisms of the intralesional cryosurgery as well as to visualize the tissue damage when compared with the standard contact cryosurgery technique. Procedure: A specially designed cryoneedle (U.S patent 6,503,246) is inserted (usually under local anesthesia with 0.5% Bupivacaine Hcl) into the long axis of the HSK so as to maximize the volume of the HSK to be frozen. The cryoneedle is connected by an adaptor to a cryogun filled with liquid nitrogen, which is introduced into the cryoprobe thereby freezing the HSK. After the HSK is completely frozen, the cryoprobe defrosts and is withdrawn. Results: An average of 51.4 % of scar volume reduction was achieved following one session of intralesional cryosurgery treatment (average preoperative HSK volume= 1.82 ± 0.33; average post-treatment volume= 0.95 ± 0.21; p< 0.0022). Specifically, for auricular and lobular keloids the average volume reduction was 67.4 ± 23% [2.89 ± 0.64 cm3 before treatment; 1.17 ± 0.46 cm3 after treatment (p<0.005). In 8 scars of the 112 no response to the intralesional treatment was achieved. Significant alleviation of objective and subjective clinical symptoms was documented. Mild pain or discomfort during and after the procedure was easily managed. Only mild local edema and epidermolysis, followed by a short re-epitheliazation period, were evident. During the 18-month follow-up period there was no evidence of bleeding, infection, adverse effects, or permanent depigmentation. The histomorphometric analysis demonstrated rejuvenation of the treated scars, i.e., parallelization, and a more organized architecture of the collagen fibers when compared to the pre-treated scars. The thermal history during the intralesional cryosurgery procedure demonstrated a significant different pattern when compared with the contact technique. Conclusion: This study demonstrated the increased efficacy of this method due to increased freezing area of deep scar material compared with that obtained with contact/spray probes. As a result, fewer treatment cycles are needed. Since the re-epitheliazation period is short, treatment intervals— if any can be shortened to 2-3 weeks. This intralesional cryoneedle method is simple to operate, safe to use, necessitates less postoperative care of the wound, and can easily be added to any preexisting cryosurgical unit.
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