Jeong Hyun Cheon

Background Adipose-derived stem cells (ADSCs) promote lymphangiogenesis, though their integration with vascularized lymph node transfer (VLNT) is not well-explored. Unlike ADSCs, the stromal vascular fraction (SVF) can be obtained intraoperatively without the need for cell culture, making it ideal for incorporation into VLNT in a single-stage surgical procedure. This study evaluates the impacts of combined VLNT and SVF therapy using a rabbit hindlimb model. Method New Zealand white rabbits were divided into four groups: control, VLNT only, SVF only, and combined VLNT plus SVF. The VLNT procedure involved transferring a pedicled lymph node flap, while the SVF was harvested and injected into the perinodal tissue. Postoperative assessments included measuring edema volume, performing ICG lymphography, conducting histological analysis, and measuring VEGF-C and LYVE-1 expression. Results Initial increases in hindlimb edema volume were noted, but a significant decrease occurred by week 4, particularly in the VLNT group and VLNT plus SVF group compared to the control group. Histological evaluations indicated that the combined treatment group preserved superior structural integrity of the lymph nodes, with a decreased proportion of fibroadipose tissue compared to the VLNT-only group. Elevated VEGF-C expression was observed in the SVF-treated groups, as confirmed by both RT-PCR and ELISA analyses at week 4. Additionally, the combined VLNT plus SVF group showed increased LYVE-1 expression by week 8. Conclusion The results suggest that SVF can be effectively integrated with VLNT in a single-stage procedure, enhancing the viability and structural integrity of vascularized lymph nodes. These results highlight the potential of this combined approach as a promising therapeutic strategy for advanced-stage lymphedema, meriting further exploration in clinical trials.

Background: The occurrence of thyroid cancer has increased dramatically, and postoperative scars are placed at easily visible locations. Many patients show stronger desire for scar prevention. So far, numerous approaches have been discussed for the treatment of scars; this study is conducted to verify whether the early application of combined therapy contributes to minimal scar formation.Methods: Between March 2019 and December 2019, total of 64 patients with thyroidectomy scars of a size greater than 4.5 cm located on the anterior neck were enrolled in this prospective pilot study. Subjective and objective evaluation were carried out using the Patient and Observer Scar Assessment Scale (POSAS) at one, two, and six months after operation. Results were compared between a treatment group and a non‐treatment group.Results: In PSAS score, the mean values of pain, itching sensation, pliability, thickness, and relief were significantly higher in the laser and steroid treatment group (p = 0.009, p = 0.000, p = 0.013, p = 0.002, and p = 0.007). The value of color of the scars showed no significant differences (p = 0.504). In OSAS score, parameter of thickness, relief, and surface area score was significantly higher score in the combination group (p = 0.029, 0.035, and 0.020), while vascularity, pigmentation, and pliability were not significantly different between two groups (p = 0.548, p = 0.983, and p = 0.128).Conclusion: This study demonstrates that early combination therapy contributes to scar improvement to a meaningful extent based on POSAS. We believe that the combined therapy has a synergy effect on scar management, which improves the patients’ quality of life in relation to their postoperative scars.

Background In microtia patients with bilateral hearing impairment, hearing improvement is crucial for language development and performance. External auditory canal reconstruction (EACR) has been performed to improve hearing, but often results in complications. We performed transcutaneous bone conduction implant (TBCI) surgery in these patients. This study aimed to evaluate the safety and efficacy of TBCI surgery. Methods A retrospective review was performed of five patients who underwent auricular reconstruction and TBCI surgery and 12 patients who underwent EACR between March 2007 and August 2018. Hearing improvement was measured based on the air-bone gap values using pure-tone audiometry over a 6-week postoperative period. We reviewed other studies on hearing improvement using EACR and compared the findings with our results. The surgical techniques for TBCI were reviewed through case analyses. Results Postoperative hearing outcomes showed a significant improvement, with a mean gain of 34.1 dB in the TBCI cohort and 14.1 dB in the EACR cohort. Both gains were statistically significant; however, the TBCI cohort showed much larger gains. Only three of the 12 patients who underwent EACR achieved hearing gains of more than 20 dB, which is consistent with previous studies. All patients who underwent TBCI surgery demonstrated hearing gains of more than 20 dB and experienced no device-related complications. Conclusions TBCI is a safe and effective method of promoting hearing gains in microtia patients with bilateral hearing impairment. TBCI surgery provided better hearing outcomes than EACR and could be performed along with various auricular reconstruction techniques using virgin mastoid skin.

Background In implant-based breast reconstruction, acellular dermal matrix (ADM) is essential for supporting the inferolateral pole. Recent studies have compared non-sterilized freeze-dried ADM and sterilized pre-hydrated ADM, but have not assessed whether differences were attributable to factors related to sterile processing or packaging. This study was conducted to compare the clinical outcomes of breast reconstruction using two types of sterile-processed ADMs. Methods Through a retrospective chart review, we analyzed 77 consecutive patients (85 breasts) who underwent tissue expander/implant breast reconstruction with either freeze-dried ADM (35 breasts) or pre-hydrated ADM (50 breasts) from March 2016 to February 2018. Demographic variables, postoperative outcomes, and operative parameters were compared between freeze-dried and pre-hydrated ADM. Biopsy specimens were obtained for histologic analysis. Results We obtained results after adjusting for variables found to be significant in univariate analyses. The total complication rate for freeze-dried and pre-hydrated ADMs was 25.7% and 22.0%, respectively. Skin necrosis was significantly more frequent in the freeze-dried group than in the pre-hydrated group (8.6% vs. 4.0%, P=0.038). All other complications and operative parameters showed no significant differences. In the histologic analysis, collagen density, inflammation, and vascularity were higher in the pre-hydrated ADM group (P=0.042, P=0.006, P=0.005, respectively). Conclusions There are limited data comparing the outcomes of tissue expander/implant breast reconstruction using two types of sterile-processed ADMs. In this study, we found that using pre-hydrated ADM resulted in less skin necrosis and better integration into host tissue. Pre-hydrated ADM may therefore be preferable to freeze-dried ADM in terms of convenience and safety.