Distribution of Perigastric Station 4d Lymph Nodes in Vascularized Gastroepiploic Lymph Node Transfer: An Anatomic Study and Case Series.

BACKGROUND: Vascularized gastroepiploic lymph node transfer (VGLNT) is a well-accepted surgical treatment for restoring physiological function in chronic lymphedema. However, the inclusion of substantial lymph nodes (LNs) in the flap remains uncertain. This study aimed to identify the anatomical basis for reliable flap harvest for VGLNT. PATIENTS AND METHODS: The anatomy of perigastric station 4d LNs was studied in healthy cadavers (n = 15) and patients with early gastric cancer (EGC) (n = 27). The omentum was divided into three segments: proximal, middle, and distal from the origin of the right gastroepiploic vessels. The flap dimension, number, location, size of LNs, and caliber of the vessels were reviewed. Eight patients underwent VGLNT for upper/lower limb lymphedema. RESULTS: The mean numbers of LNs in the proximal, middle, and distal segment were 2.5, 1.4, 0.5 in the cadavers, and 4.9, 2.7, 0.7 in the gastrectomy specimens, respectively. The proximal third included a significantly greater number of LNs than the distal third in the cadaveric (p = 0.024) and ECG (p = 0.016) specimens. A total of 95% of the LNs were located within proximal two-thirds of the flap from the vessel origin both in the cadavers (21.0 × 5.0 cm) and in the gastrectomy specimens (20 × 3.5 cm). In VGLNT, the transferred flap was 25.5 ± 6.9 × 4.1 + 0.7 cm in dimension, containing a mean number of 6.5 ± 1.9 LNs. At postoperative 6 months, the volumetric difference was significantly reduced by 22.8 ± 9.2% (p < 0.001). CONCLUSIONS: This study provides a distinct distribution pattern of station 4d LNs. Inclusion of the proximal two-thirds of the flap, which carries majority of the LNs, is recommended for VGLNT.

Histological Comparison of Nanofat and Lipoconcentrate: Enhanced Effects of Lipoconcentrate on Adipogenesis and Angiogenesis.

BACKGROUND: Nanofat and lipoconcentrate contain adipose-derived stem cells and growth factors, and have wide clinical applications in the regenerative field. This study aimed to investigate the microenvironmental changes associated with nanofat and lipoconcentrate. METHODS: Conventional fat, nanofat, or lipoconcentrate (0.2 mL each, n = 5 per group) were injected subcutaneously into the dorsal flanks of athymic nude mice. The graft weights were measured at postoperative week 4; the grafts and their overlying skin were used for histological analyses. RESULTS: Weights of the lipoconcentrate grafts were significantly greater than those of the conventional fat (p < 0.05) and nanofat (p < 0.01) grafts. There was no significant difference in inflammation, oil cysts, and fibrosis between the conventional fat and nanofat groups. Histological examination of the lipoconcentrate grafts showed less macrophage infiltration and the formation of fibrosis and oil cysts. Additionally, adipogenesis and angiogenesis were induced more in the lipoconcentrate grafts than in the nanofat grafts (p < 0.01). Lipoconcentrate and nanofat improved dermal thickness (p < 0.001 and p < 0.01, respectively, versus the baseline). CONCLUSION: Lipoconcentrate grafts had greater volume and shape retention than conventional fat and nanofat grafts. They had better histological structure and acted as scaffolds for adipogenesis and angiogenesis. Both products showed regenerative effects on dermal thickness; however, only lipoconcentrate grafts had the required volume and regenerative effects, allowing it to serve as a novel adipose-free grafting method for facial rejuvenation and contouring. NO LEVEL ASSIGNED: This journal requires that authors assign a level of evidence to each submission to which Evidence-Based Medicine rankings are applicable. This excludes Review Articles, Book Reviews, and manuscripts that concern Basic Science, Animal Studies, Cadaver Studies, and Experimental Studies. For a full description of these Evidence-Based Medicine ratings, please refer to Table of Contents or the online Instructions to Authors www.springer.com/00266 .

Comparison of Stored and Fresh Injectable Acellular Adipose Matrix in Soft Tissue Reconstruction in a Murine Model.

BACKGROUND: We previously showed comparable volume effects of injections of acellular adipose matrix (AAM), an adipose tissue-derived extracellular matrix, and conventional fat grafting in a murine model. Thus, AAM could be a novel allogenic injectable product. However, its retention rate poses a concern, as repeated AAM injections may be required in some cases. This study investigated the biological properties and therapeutic value of stored AAM and compared them with those of fresh AAM, in a murine model. METHODS: AAM was manufactured from fresh human abdominoplasty fat. Fresh and stored injectable AAM was prepared within 24 h and 3 months after generation, respectively. Either fresh or stored injectable AAM was injected into the scalp of athymic nude mice (0.2 mL/sample, n = 6 per group). After 8 weeks, graft retention was assessed through weight measurement, and histological analysis was performed, including immunofluorescence staining for CD31 and perilipin. RESULTS: Retention rate was significantly reduced in the stored compared to the fresh injectable AAM group. Nevertheless, histological analysis revealed comparable inflammatory cell presence, with minimal capsule formation, in both groups. Adipogenesis occurred in both groups, with no significant difference in the blood vessel area (%) between groups. CONCLUSIONS: Although the volume effects of stored AAM for soft tissue reconstruction were limited compared to those of fresh injectable AAM, stored AAM had similar capacity for adipogenesis and angiogenesis. This promising allogeneic injectable holds the potential to serve as an effective "off-the-shelf" alternative for repeated use within a 3-month storage period. NO LEVEL ASSIGNED: This journal requires that authors assign a level of evidence to each submission to which Evidence-Based Medicine rankings are applicable. This excludes Review Articles, Book Reviews, and manuscripts that concern Basic Science, Animal Studies, Cadaver Studies, and Experimental Studies. For a full description of these Evidence-Based Medicine ratings, please refer to the Table of Contents or the online Instructions to Authors https://link.springer.com/journal/00266 .

Effect of Injectable Acellular Adipose Matrix on Soft Tissue Reconstruction in a Murine Model.

BACKGROUND: The extracellular matrix isolated from adipose tissue, known as acellular adipose matrix (AAM), represents a novel biomaterial. AAM functions as a scaffold that not only supports stem cell proliferation and differentiation but also induces adipogenesis and angiogenesis. This study aims to investigate the volumetric effects and microenvironmental changes associated with injectable AAM in comparison to conventional fat grafting. METHODS: AAM was manufactured from fresh human abdominoplasty fat using a mechanically modified method and then transformed into an injectable form. Lipoaspirate was harvested employing the Coleman technique. A weight and volume study was conducted on athymic nude mice by injecting either injectable AAM or lipoaspirate into the scalp (n=6 per group). After eight weeks, graft retention was assessed through weight measurement and volumetric analysis using micro-computed tomography (micro-CT) scanning. Histological analysis was performed using immunofluorescence staining for perilipin and CD31. RESULTS: Injectable AAM exhibited similar weight and volume effects in murine models. Histological analysis revealed comparable inflammatory cell presence with minimal capsule formation when compared to conventional fat grafts. Adipogenesis occurred in both AAM-injected and conventional fat graft models, with no significant difference in the blood vessel area (%) between the two. CONCLUSIONS: In summary, injectable AAM demonstrates effectiveness comparable to conventional fat grafting concerning volume effects and tissue regeneration in soft tissue reconstruction. This promising allogeneic injectable holds the potential to serve as a safe and effective "Off-the-Shelf" alternative in both aesthetic and reconstructive clinical practices. NO LEVEL ASSIGNED: This journal requires that authors assign a level of evidence to each submission to which Evidence-Based Medicine rankings are applicable. This excludes Review Articles, Book Reviews, and manuscripts that concern Basic Science, Animal Studies, Cadaver Studies, and Experimental Studies. For a full description of these Evidence-Based Medicine ratings, please refer to the Table of Contents or the online Instructions to Authors www.springer.com/00266 .

Redo hepatic artery reconstruction for thrombosis without retransplantation in 1355 adult living donor liver transplantations.

Hepatic artery thrombosis (HAT) after liver transplantation is associated with a marked increase in morbidity, leading to graft and patient loss. We evaluated the outcomes of adult living donor liver transplantation patients with HAT under an aggressive surgical intervention. A total of 1355 recipients underwent adult living donor liver transplantation at the Seoul National University Hospital. Surgical redo reconstruction for HAT was performed in all cases except in those with graft hepatic artery injury and late detection of HAT. Postoperative HAT developed in 33 cases (2.4%) at a median time of 3.5 days. Thirty patients (90.9%) underwent redo-arterial reconstruction. The survival rates in patients with HAT were similar to the rates in those without HAT (72.7% vs. 83.8%, p = 0.115). Although graft survival rates were lower in patients with HAT (84.8%) than in those without HAT (98.0%) ( p < 0.001), the graft survival rate was comparable (92.0% vs. 98.0%, p = 0.124) in the 25 patients with successful revascularization. Biliary complication rates were higher in patients with HAT (54.5%) than in those without HAT (32.0%) ( p = 0.008). In conclusion, the successful redo reconstruction under careful selection criteria saved the graft without retransplantation in 96.0% of the cases. Surgical revascularization should be preferentially considered for the management of HAT in adult living donor liver transplantation.

Oncologic Safety and Efficacy of Cell-Assisted Lipotransfer for Breast Reconstruction in a Murine Model of Residual Breast Cancer.

BACKGROUND: Cell-assisted lipotransfer (CAL) is a novel technique for fat grafting that combines the grafting of autologous fat and adipose-derived stromal cells (ASCs) to enhance fat graft retention; however, its oncologic safety is controversial. METHODS: Herein, we investigated the oncologic safety of CAL for breast reconstruction using a murine model of residual breast cancer. Various concentrations of 4T1 cells (murine breast cancer cells) were injected into female mastectomized BALB/c mice to determine the appropriate concentration for injection. One week after injection, mice were divided into control (100 µL fat), low CAL (2.5 × 105 ASCs/100 µL fat), and high CAL (1.0 × 106 ASCs/100 µL fat) groups, and fat grafting was performed. The injection of 5.0 × 103 4T1 cells was appropriate to produce a murine model of residual breast cancer. RESULTS: The weight of the fat tumor mass was significantly higher in the high CAL group than in the other groups (p < 0.05). However, the estimated tumor weight was not significantly different between the groups. Additionally, the fat graft survival rate was significantly higher in the high CAL group than in the control and low CAL groups (p < 0.05). No significant difference was noted in the percentage of Ki-67-positive cells, suggesting that tumor proliferation was not significantly different between the groups. CONCLUSION: In summary, CAL significantly improved fat graft survival without affecting tumor size and proliferation in a murine model of residual breast cancer. These results highlight the oncologic safety of CAL for breast reconstruction. NO LEVEL ASSIGNED: This journal requires that authors assign a level of evidence to each submission to which Evidence-Based Medicine rankings are applicable. This excludes Review Articles, Book Reviews, and manuscripts that concern Basic Science, Animal Studies, Cadaver Studies, and Experimental Studies. For a full description of these Evidence-Based Medicine ratings, please refer to the Table of Contents or the online Instructions to Authors www.springer.com/00266 .

Revisiting metformin therapy for the mitigation of diabetic foot ulcer in patients with diabetic kidney disease from real-world evidence.

Diabetic foot ulcer and diabetic kidney disease are diabetes-related chronic vascular complications that strongly correlate with high morbidity and mortality. Although metformin potentially confers a wound-healing advantage, no well-established clinical evidence supports the benefit of metformin for diabetic foot ulcer. Thus, this study investigated the effect of metformin on diabetic foot ulcer from a large diabetic kidney disease cohort for the first time. This retrospective cohort study enrolled 10 832 patients who visited the nephrology department more than twice at two South Korean tertiary-referral centers between 2001 and 2016. The primary outcome was diabetic foot ulcer events; secondary outcomes included hospitalization, amputation, a composite of amputation or vascular intervention, and Wagner Grade ≥ 3. Multivariate Cox analysis and propensity score matching (PSM) were used to balance baseline intergroup differences between metformin users and non-users. In total, 4748 patients were metformin users, and 6084 patients were metformin non-users. Over a follow-up period of 117.5 ± 66.9 months, the diabetic foot ulcer incidence was 5.2%. After PSM, metformin users showed a lower incidence of diabetic foot ulcer events than metformin non-users (adjusted hazard ratio 0.41; p < 0.001). In a sensitivity analysis of 563 patients with diabetic foot ulcer, metformin usage was associated with lower severity in all four secondary outcomes: hospitalization (adjusted hazard ratio 0.33; p < 0.001); amputation (adjusted hazard ratio 0.44; p = 0.001); composite of amputation or vascular intervention (adjusted hazard ratio 0.47; p < 0.001); and Wagner Grade ≥ 3 (adjusted hazard ratio 0.39; p < 0.001). In conclusion, metformin therapy in patients with diabetic kidney disease can lower diabetic foot ulcer incidence and progression.

Medial Plantar Fasciocutaneous Flap Reconstruction for Load-Bearing Foot Defects in Patients With Acral Melanoma.

BACKGROUND: Acral lentiginous melanoma (ALM) is a rare subtype of malignant melanoma that usually involves the weight-bearing plantar area. Plantar defect reconstruction has traditionally been performed with skin grafts or free flaps. This study examined the efficacy and safety of a medial plantar artery perforator flap (MPAPF) for plantar defect reconstruction after wide excision of an ALM. METHOD: Twenty-five patients who underwent reconstruction with a MPAPF between 2011 and 2021 were enrolled in this study. The defects were classified into 6 plantar zones. Demographic and clinical data were retrospectively analyzed. RESULTS: Reconstruction with medial plantar fasciocutaneous island flaps was performed in all cases, except for 4 patients who had lesions in forefoot, which required free medial plantar flaps. Defects in lateral and posterior heel were more likely to present with venous congestion and require longer healing times and revision surgery (P < 0.05). The average follow-up period was 49 months. Four and 5 patients developed local recurrence and distant metastasis, respectively. Four cases of hyperkeratosis and paresthesia were documented, but there were no cases of ulceration or wound dehiscence. None of the cases required secondary debulking procedures. CONCLUSIONS: The MPAPF is safe and effective for plantar defect reconstruction among patients with ALM. Meticulous dissection and adequate tunneling are needed, particularly for defects in the lateral and posterior heel, to minimize flap congestion and revision operations.

Dextroplantation of Left Liver Graft in Infants.

The position of the left side liver graft is important, and it could lead to complications of the hepatic vein (HV) and portal vein (PV), especially in a small child using a variant left lateral section (vLLS) graft. The purpose of this study was to evaluate the outcome of a novel technique for the implantation of a vLLS graft to the right side (dextroplantation) in infants. For 3 years, 10 consecutive infants underwent dextroplantation using a vLLS graft (group D). The graft was implanted to the right side of the recipient after 90° counterclockwise rotation; the left HV graft was anastomosed to inferior vena cava using the extended right and middle HV stump, and PV was reconstructed using oblique anastomosis without angulation. Surgical outcomes were compared with the historical control group (n = 17, group C) who underwent conventional liver transplantation using a vLLS during infancy. Group D recipients were smaller than group C (body weight <6 kg: 50.0% versus 11.8%; P = 0.03). The rate of graft-to-recipient weight ratio >4% was higher in group D (60.0%) than C (11.8%; P = 0.01). Surgical drains were removed earlier in group D than in group C (15 versus 18 postoperative days [PODs]; P = 0.048). Each group had 1 PV complication (10.0% versus 5.9%); no HV complication occurred in group D, but 3 HV complications (17.6%) occurred in group C (P > 0.05). Hospital stay was shorter in group D than in group C (20 versus 31 PODs; P = 0.02). Dextroplantation of a vLLS graft, even a large-for-size one, was successful in small infants without compromising venous outcomes, compared with conventional vLLS transplantation. We could remove the surgical drains earlier and reduce hospital stays in cases of dextroplantation.

Compact Fat Grafting: A Novel Method to Improve Graft Retention Through Modulation of Adipocyte Size.

BACKGROUND: The viable zone where adipocytes and/or adipose-derived stem cells survive is present at the surface of graft fat tissue; however, there is controversy regarding the zone thickness. Graft retention could be improved if more adipocytes are included in the zone. OBJECTIVES: We hypothesize that a temporary reduction in adipocyte size prior to grafting could increase the number of adipocytes in the viable zone. We reduced the adipocyte size by treatment with MLN4924, which controls lipid accumulation in adipocytes, and investigated the histological and microenvironmental changes in grafted fat. METHODS: Subcutaneous fat harvested from wild-type C57BL/6J mice was chopped into small pieces; treated with dimethyl sulfoxide (control group), 0.25 µM MLN4924, or 0.5 µM MLN4924 for 4 days; and grafted into recipient C57BL/6J mice at the supraperiosteal plane of the skull. RESULTS: The reduced adipocyte size in response to MLN4924 treatment was restored within 8 weeks after fat grafting. The MLN4924-treated groups exhibited substantially greater graft volume, lower tissue hypoxia, and higher production of M2 macrophages compared with the control group. CONCLUSIONS: Grafting with compact fat that had smaller adipocytes improved the microenvironment by modulating tissue hypoxia and macrophage polarization, leading to improved graft retention. Therefore, compact fat grafting may offer a new clinical strategy without the need for stem cell manipulation.

The molecular pathogenesis of Trichilemmal carcinoma.

BACKGROUND: Trichilemmal carcinoma (TC) is an extremely rare hair follicle tumor. We aimed to explore the genetic abnormalities involved in TC to gain insight into its molecular pathogenesis. METHODS: Data from patients diagnosed with TC within a 12-year period were retrospectively reviewed. Genomic DNA isolated from a formalin-fixed paraffin-embedded (FFPE) tumor tissue block was sequenced and explored for a panel of cancer genes. RESULTS: DNA was extracted from the FFPE tissue of four patients (50% female; mean age, 51.5 years) diagnosed with TC for analysis. The tumor was located in the head and neck of three patients and in the shoulder of one patient. TP53 mutations (p.Arg213*, p.Arg249Trp, and p.Arg248Gln) were found in three patients. Fusions previously identified in melanoma were detected in two patients (TACC3-FGFR3 and ROS1-GOPC fusions). Other mutations found included NF1-truncating mutation (Arg1362*), NRAS mutation (p.Gln61Lys), TOP1 amplification, and PTEN deletion. Overall, genetic changes found in TC resemble that of other skin cancers, suggesting similar pathogenesis. All patients with TP53 mutations had aggressive clinical course, two who died (OS 93 and 36 months), and one who experienced recurrent relapse. CONCLUSIONS: We reported the genomic variations found in TC, which may give insight into the molecular pathogenesis. Overall, genetic changes found in TC resembled that of other skin cancers, suggesting similar pathogenesis. TP53 mutations was were identified in patients who had an aggressive clinical course. Genetic alterations identified may further suggest the potential treatment options of TC.

Oncologic outcomes after immediate breast reconstruction following mastectomy: comparison of implant and flap using propensity score matching.

BACKGROUND: Although immediate breast reconstruction has been reported to be oncologically safe, no affirmative study comparing the two reconstruction methods exists. We investigated breast cancer recurrence rates in two breast reconstruction types; implant reconstruction and autologous flap reconstruction. METHODS: A retrospective cohort study was performed on propensity score-matched (for age, stage, estrogen receptor status) patients who underwent IBR after mastectomy at Seoul National University Hospital between 2010 and 2014. The main outcomes determined were locoregional recurrence-free interval (LRRFI) and disease-free interval (DFI). RESULTS: We analyzed 496 patients among 731 patients following propensity score matching (Median age 43, 247 implant reconstruction and 249 flap reconstruction). During median follow-up of 58.2 months, DFI was not different between the two groups at each tumor stage. However, flap reconstruction showed inferior DFI compared to implant reconstruction in patients with high histologic grade (p = 0.012), and with high Ki-67 (p = 0.028). Flap reconstruction was related to short DFI in multivariate analysis in aggressive tumor subsets. Short DFI after flap reconstruction in aggressive tumor cell phenotype was most evident in hormone positive/Her-2 negative cancer (p = 0.008). LRRFI, on the other hand, did not show difference according to reconstruction method regardless of tumor cell aggressiveness. CONCLUSION: Although there is no difference in cancer recurrence according to reconstruction method in general, flap-based reconstruction showed higher systemic recurrence associated with histologically aggressive tumors.

Single-stage cross-facial nerve grafting has a result equivalent to that of two-stage cross-facial nerve grafting.

BACKGROUNDS: Cross-face nerve grafting (CFNG) is an important treatment for patients with facial palsy. Currently, two-stage CFNG is frequently performed. CFNG is performed first, followed by coaptation when innervation reaches the grafted nerve ending. The present study compared single-stage CFNG with conventional two-stage CFNG. METHODS: We retrospectively reviewed data of 17 patients who underwent CFNG with zygomatic and buccal branch with hypoglossal crossover. Patients with single-stage (group 1) and two-stage (group 2) CFNG were comparatively analyzed 2 years postoperatively. There were nine and eight patients in groups 1 and 2, respectively. The patient's perioperative status was measured with imaging and animation using the Yanagihara grade, altitude, and angle differences of the oral commissure and eye closure. RESULTS: Patients in group 1 could recognize their first postoperative spontaneous movement earlier than those in group 2 (268.3 ± 25.1 days vs. 327.5 ± 51.3 days, respectively, p = 0.015). The Yanagihara grade significantly improved for patients in both groups postoperatively (group 1: 12.8 ± 5.5 to 25.3 ± 6.1, p < 0.01; group 2: 12.4 ± 5.6 to 24.3 ± 5.0, p = 0.012). Height and angle difference of the oral commissure showed a significant improvement during resting and smiling in both groups. Eye closure also showed significant improvement in both groups (group 1: 4.1 ± 0.6 to 2.6 ± 0.5, p < 0.01; group 2: 4.0 ± 0.5 to 2.8 ± 0.7, p < 0.01). There was no significant difference in the postoperative improvement rate between the groups. CONCLUSIONS: Single-stage CFNG shows results equivalent to those of two-stage CFNG. Single-stage CFNG is associated with a shorter treatment period and fewer operations.

Giant Ventral Lipoma of the Neck.

Giant lipomas are rarely found in the head and neck region. A 67-year-old male patient presented with a massive ventral swelling of his neck extending from the lower margin of the mandible to the clavicle. The mass had slowly grown over 20 years without causing any symptoms, except for considerable psychological stress because of the disfiguration of the patient's profile appearance. Contrast magnetic resonance imaging suggested a lipomatous soft tissue lesion. The surgically removed tumor measured 32 × 20 × 4 cm. Surgery was completed without any intraoperative complications or injury to the critical structures of the neck. The patient was satisfied with the cosmetic result of the operation, and histopathological examination confirmed a lipoma.

Complication of Ruptured Poly Implant Prothèse® Breast Implants Combined with AQUAfilling® Gel Injection: A Case Report and Literature Review.

INTRODUCTION: We describe the first case of a patient who received AQUAfilling® gel (Biomedica, Prague, Czech Republic) after augmentation with Poly Implant Prothèse® (PIP) breast implants and later developed breast deformity with bilateral implant rupture. CASE REPORT: A 49-year-old Korean female patient who received breast augmentation with PIP implants 18 years ago and subsequent insertion of AQUAfilling® gel 1 year ago visited our center with a chief complaint of pain and decreased implant sizes in both breasts. Breast implant and foreign body removal operation was performed for both breasts under general anesthesia. Intraoperative gross findings, pathologic findings, and tissue culture results were analyzed. RESULTS: Our diagnosis included rupture of the implants in both breasts with leakage of injected material resulting in inflammation of the pericapsular area and pectoralis muscle. The intraoperative gross findings and results of the pathologic report showed that the implants were exposed with massive leakage of AQUAfilling® gel in the pericapsular space, and the pectoralis major was mixed with AQUAfilling® gel-like liquid and tissue with an inflammatory reaction. CONCLUSIONS: Surgeons should be careful in performing AQUAfilling® gel injection for breast augmentation, especially when combined with breast implant insertion. AQUAfilling® gel itself is not yet proven safe in the long term, so more research on this topic is warranted. Additionally, surgeons should be aware of the comparatively high risk of implant rupture and foreign body reaction with PIP implants, and warn patients accordingly. LEVEL OF EVIDENCE V: This journal requires that authors assign a level of evidence to each article. For a full description of these Evidence-Based Medicine ratings, please refer to the Table of Contents or the online Instructions to Authors www.springer.com/00266 .

Inhibition Mechanism of Acellular Dermal Matrix on Capsule Formation in Expander-Implant Breast Reconstruction After Postmastectomy Radiotherapy.

BACKGROUND: Capsular contracture is one of the most common complications of expander-implant breast reconstruction. Recently, clinical reports have shown that use of an acellular dermal matrix (ADM) to cover breast implants decreases incidence of capsular contracture, but the underlying mechanism is unclear. Here, we examine how ADM reduces capsular formation in expander-implant breast reconstruction and identify cellular and molecular mechanisms of ADM-mediated reduction of capsular contracture in nonirradiated and irradiated patients. METHODS: Thirty patients who underwent immediate two-stage implant-based breast reconstruction were included; 15 received radiotherapy. While the tissue expander was changed to permanent silicone implant, biopsies of the subpectoral capsule and ADM capsule were performed. Capsule thickness, immunohistochemistry of α-smooth muscle actin (αSMA), vimentin, CD31, F4/80 expression, αSMA and CD31 coexpression, and relative gene expression levels of transforming growth factor (TGF)-ß1 and platelet-derived growth factor (PDGF)-B were investigated. RESULTS: Irradiated submuscular capsules were thicker than nonirradiated submuscular capsules, but the thickness of ADM capsules did not significantly differ between nonirradiated and irradiated groups. Levels of myofibroblasts, fibroblasts, vascularity, EndoMT, and macrophages were significantly lower in ADM capsules than in submuscular capsules. With the exception of EndoMT, all others were increased in irradiated submuscular capsules compared with nonirradiated submuscular capsule, while none significantly differed between nonirradiated and irradiated ADM capsules. CONCLUSIONS: Use of ADM reduced myofibroblasts, vascularity, fibroblasts, and EndoMT in capsule tissues. Moreover, ADM use decreased macrophages, a key regulator of tissue fibrosis, as well as TGF-ß1 and PDGF-B expression. We hope that these results provide basic concepts important for prevention of capsular contracture.

Optimal Reconstruction Method for Large Radionecrosis Following Breast Cancer Treatment: Utility of Free Transverse Rectus Abdominis Myocutaneous Flap Using Contralateral Internal Mammary Artery as Recipient.

INTRODUCTION: In extensive radionecrosis following radiotherapy for breast cancer (BC) treatment, the defect after excision can be reconstructed with a transverse rectus abdominis myocutaneous (TRAM) flap. In this study, we report outcome of free TRAM flap using contralateral internal mammary artery (IMA) as a recipient in comparison with pedicled TRAM. METHODS: We reviewed cases of chest wall radionecrosis following BC treatment during the past 8 years. Radionecrosis involving full-thickness soft tissue with defect sizes greater than 10 × 10 cm were included. We compared the outcomes of patients who underwent reconstruction with either pedicled TRAM flaps or free TRAM flaps. We used IMA as a recipient for free TRAM flap, whereas we used contralateral superior epigastric artery-based flap for pedicled TRAM. RESULTS: A total of 14 BC patients underwent chest wall reconstruction due to radionecrosis: 7 received pedicled TRAM flaps, 5 received free TRAM flaps, and 2 were excluded because of the small defect size. The pedicled and free TRAM groups were similar in patient demographics and defect size. However, distal flap loss rate was significantly higher in the pedicled TRAM group compared with the free TRAM group (P = 0.028). There was no difference in abdominal hernia incidence between the 2 groups (P = 0.100). CONCLUSIONS: Wide chest wall defects caused by radionecrosis following BC treatment can be successfully reconstructed with a free TRAM flap that uses a contralateral IMA as a recipient. The free TRAM flap demonstrates a lower rate of distal flap loss than the pedicled TRAM flap, hence reduces the risk of severe morbidity.