Identification of predisposing factors for osteonecrosis of the jaw after marginal mandibulectomy in the surgical management of oral squamous cell carcinoma.

BACKGROUND: The aim of this study is to evaluate osteonecrosis of the jaw (ONJ) with the extent of marginal mandibulectomy. METHODS: Between January 2006 and December 2012, 3087 patients undergoing ablative resection were consecutively enrolled. Among them, 345 cases undergoing marginal mandibulectomy were retrospectively reviewed. RESULTS: The occurrence of ONJ was 5.51% and associated with body mass index, overall stage, diabetes, concomitant mandibulotomy, and radiotherapy (P = 0.023, 0.033, 0.009, 0.016, and 0.006, respectively). As for bone parameters based on radiological measurements after marginal mandibulectomy, resected bone height, remaining bone height to original bone height ratio, and resected bone height to original bone height ratio were associated with ONJ. In multivariate logistic analyses, concomitant mandibulotomy, radiotherapy, diabetes, resected bone height of >14.5 mm, resected bone height to original bone height ratio of >49.5%, and remaining bone height to original bone height ratio of <53.5% indicated higher risks for ONJ (adjusted HR: 4.345, 4.152, 4.079, 3.402, 3.541, and 3.211; P = 0.018, 0.013, 0.009, 0.021, 0.018, and 0.043, respectively). CONCLUSIONS: This study demonstrated the predisposing factors and parameters associated with ONJ with marginal mandibulectomy; more caution is necessitated in performing marginal mandibulectomy in patients with multiple risks to prevent ONJ.

Proposed pathway and mechanism of vascularized lymph node flaps.

OBJECTIVE: To investigate the pump mechanism and pathway of lymph transit in vascularized lymph node flaps. BACKGROUND: Microsurgical treatment of lymphedema with vascularized lymph node transfer can improve signs and symptoms of disease, but the pathways and mechanisms of these flaps warrant further exploration. METHODS: (Animal model) 72 flaps were raised in 18 rats: 36 groin flaps contained lymph nodes (LN), 36 deep inferior epigastric artery perforator flaps did not (non-LN). Indocyanine green (ICG) was added into normal saline (NS), 1%, 3%, 5%, 7% and 10% albumin. Three rats were assigned to each group. LN and non-LN flaps were submerged in solution and surveyed for venous fluorescence. In the 7% albumin and NS groups, volumetric change of solution was measured. (Human model) A similar experiment was performed in humans using five submental LN flaps. RESULTS: (Animal model) Fluorescence was detected in the venous pedicle of LN flaps submerged in 5%, 7% and 10% albumin, and half of flaps submerged in 3% albumin. Fluorescence was not detected in LN node flaps submerged in ICG-containing NS or 1% albumin solution. Fluorescence was not detected in non-LN flaps. There was greater volume reduction with LN flaps than non-LN flaps (p<0.001). (Human model) Fluorescence was detected in the venous pedicle of all flaps immersed in lymph. CONCLUSIONS: ICG fluorescence was detected in the venous pedicle of rat and human LN flaps submerged in lymph or albumin when the concentration was greater than 3%. Based on these results, a pathway for lymphatic uptake is presented.

The versatility of profunda femoral artery perforator flap for oncological reconstruction after cancer resection-Clinical cases and review of literature.

BACKGROUND: The profunda feomris artery perforator (PAP) flap was recently revisited and gains popularity as an alternative method of autologous breast reconstruction. The purpose of this article is to demonstrate that PAP flap can be used reliably for reconstruction of various soft tissue defects. METHODS: A total of 55 free PAP flaps and 16 pedicle PAP flaps were transferred in 63 patients. Each case was reviewed to verify a PAP flap was performed identifying defect location, flap size, flap design, and postoperative complications. RESULTS: Seven flaps in five patients underwent breast reconstructions, 48 patients underwent head and neck reconstructions using free PAP flaps. The mean perforator number was 1.9, and the average pedicles length was 9.7 cm. The majority of perforators were musculocutaneous, and the others were septocutaneous. The mean ischemia time was 121.4 min. Minor complications included wound poor healing, flap partial necrosis, and pedicle vessels problems. Sixteen pedicle PAP flaps were transferred in 10 patients for vulvar reconstruction. Minor complications included urinary tract infection, poor wound healing, wound infection, hematoma. CONCLUSIONS: The anatomy and number of perforators of PAP flap are reliable with adequate pedicle length. This flap can be an excellent option for reconstruction of most soft tissue defects. J. Surg. Oncol. 2016;114:193-201. © 2016 Wiley Periodicals, Inc.

Successful treatment of early-stage lower extremity lymphedema with side-to-end lymphovenous anastomosis with indocyanine green lymphography assisted.

PURPOSE: This study was to investigate intraoperative assessment of side-to-end lymphovenous anastomosis (LVA) with indocyanine green (ICG) and the correlation between its patency and surgical outcome. METHODS: LVA was applied to five patients with early-stage lower extremity lymphedema. Side-to-end anastomosis and then end-to-end anastomosis were created as a second alternative. Immediately after the anastomosis, ICG was used to confirm its patency. RESULTS: The mean number of anastomoses was 2.0 ± 0.7, and the types of anastomoses were primarily side-to-end and secondarily end-to-end. The mean reduction rate was 63.8 ± 20.2% after LVA at 10 ± 6.4 months of follow-up. In all cases, the affected extremities became soft immediately after surgery, and no cellulitis episodes were observed. CONCLUSION: Side-to-end LVA can be an effective treatment for early-stage lower extremity lymphedema. ICG lymphodynamic assessment is useful not only in the preoperative identification of functional lymphatics but also in the intraoperative visualization of new drainage routes in LVA surgery. © 2015 Wiley Periodicals, Inc. Microsurgery 36:310-315, 2016.

Treating a collagen scaffold with a low concentration of nicotine promoted angiogenesis and wound healing.

BACKGROUND: Nicotine, one of the major pharmacologically active agents of cigarette smoke, has various effects on cell proliferation, and it has recently been reported to have angiogenic effects. In our previous study, we showed that the topical administration of nicotine at a low concentration accelerated wound healing. This study aimed to evaluate the efficacy of nicotine and synergistic effects of combination treatment with nicotine and basic fibroblast growth factor (bFGF) in a murine excisional wound model treated with artificial dermis. METHODS: Full-thickness defects (8 mm in diameter) were created on the backs of mice, and artificial dermis was sutured to the defects. Phosphate-buffered saline (10 µL), nicotine (10(-3), 10(-4), or 10(-5) M), bFGF (0.5 µg), and both bFGF and 10(-4) M nicotine were topically administered to the artificial dermal tissue for 7 d. The mice were killed on day 14, and the wound area, neoepithelium length, and area of newly formed capillaries in the artificial dermis were evaluated. RESULTS: The wound areas treated with 10(-4) M nicotine, bFGF, or bFGF plus 10(-4) M nicotine were significantly smaller than those in the control group. In these three groups, the neoepithelium in the bFGF plus 10(-4) M nicotine group was significantly longer than that in the other groups. There was no significant difference between the neoepithelium lengths of the control and 10(-5) M nicotine groups. The 10(-3) M nicotine group displayed the least re-epithelization among the groups. CONCLUSIONS: In this study, 10(-4) M nicotine induced angiogenesis in, and accelerated the healing of, wounds treated with artificial dermis. bFGF and nicotine had synergistic effects, and the combined use of nicotine and bFGF is an effective wound healing method.

Laser Doppler imaging evaluation of adipogenesis after adipose tissue-derived stem cell implantation.

We need a better method of assessing adipose tissue formation non-invasively than the current one, which requires resecting tissue samples in vivo. The aim of this study was to establish a system to evaluate adipogenesis using laser Doppler imaging (LDI) to measure subcutaneous microcirculation. CGSs containing adipose stem cells with or without bFGF were implanted in the backs of 30 mice. Once per week after implantation, LDI was used to evaluate blood flow at the implantation site. The implantation sites were resected at 6 weeks, and the tissue was weighed. Six weeks after implantation, LDI showed that mice who received CGS with 1 µg/cm(2) bFGF had the greatest mean blood flow, and these mice had the heaviest resected specimens, which contained the most newly formed adipose tissue. The findings for LDI and the weight findings were compatible. This study indicates that LDI could be used to assess subcutaneous tissue regeneration in vivo in a real-time, non-invasive manner.

Autologous skin reconstruction by combining epidermis and acellular dermal matrix tissue derived from the skin of giant congenital melanocytic nevi.

Giant congenital melanocytic nevi (GCMN) are defined as nevi greater than 20 cm in diameter. It is difficult to completely remove GCMN because of the lack of available skin grafts for covering the resultant defects. This study examined whether it is possible to produce reconstructed skin by combining epidermal and acellular dermal matrix (ADM) tissue derived from excised GCMN. GCMN skin samples were obtained with the informed consent of volunteer patients. The abilities of hypertonic saline (1 N NaCl), 0.05% trypsin, 0.1% SDS (sodium dodecyl sulfate), and phosphate buffered saline (PBS) to decellularize GCMN tissue were compared. The specimens were incubated in one of the test solutions at 37 °C for 48 h, before being washed with PBS at 4 °C for 14 days. Residual nuclei, residual DNA, nevus tissue viability, and the structural integrity of the basement membrane and capillaries were evaluated before treatment, and after 48 h' treatment with or without 7 or 14 days' washing. We tried to produce reconstructed skin by combining the resultant ADM with enzymatically separated GCMN epidermal tissue. The histological structure of the reconstructed skin was examined after it had been cultured for 5 days. In the SDS group, most cells had been removed after 48 h, and the DNA content of the ADM was significantly lower than in the other groups. As for viability, no significant difference was detected among the groups. The basement membrane and capillaries remained intact in all groups. After 5 days' culturing, the epidermis had become attached to the ADM in all groups, except the SDS group. SDS displayed a superior decellularization ability compared with the other methods; however, it cannot be used to produce reconstructed skin because of its toxicity. In conclusion, we produced reconstructed skin that was devoid of nevus cells by combining GCMN epidermal tissue with GCMN-derived ADM produced with NaCl or trypsin. This is a promising treatment strategy for giant nevus.

Simple and longstanding adipose tissue engineering in rabbits.

Adipose tissue engineering for breast reconstruction can be performed for patients who have undergone breast surgery. We have previously confirmed adipogenesis in mice implanted with type I collagen sponge with controlled release of fibroblast growth factor 2 (FGF2) and human adipose tissue-derived stem cells. However, in order to use this approach to treat breast cancer patients, a large amount of adipose tissue is needed, and FGF2 is not readily available. Thus, we aimed to regenerate large amounts of adipose tissue without FGF2 for a long period. Under general anesthesia, cages made of polypropylene mesh were implanted into the rabbits' bilateral fat pads. Each cage was 10 mm in radius and 10 mm in height. Minced type I collagen sponge was injected as a scaffold into the cage. Regenerated tissue in the cage was examined with ultrasonography, and the cages were harvested 3, 6, and 12 months after the implantation. Ultrasonography revealed a gradually increasing homogeneous high-echo area in the cage. Histology of the specimen was assessed with hematoxylin and eosin staining. The percentages of regenerated adipose tissue area were 76.2 ± 13.0 and 92.8 ± 6.6 % at 6 and 12 months after the implantation, respectively. Our results showed de novo adipogenesis 12 months after the implantation of only type I collagen sponge inside the space. Ultrasonography is a noninvasive and useful method of assessing the growth of the tissue inside the cage. This simple method could be a promising clinical modality in breast reconstruction.

A nomogram to predict osteoradionecrosis in oral cancer after marginal mandibulectomy and radiotherapy.

OBJECTIVE: There is no useful tool to clinically predict the occurrence of osteoradionecrosis (ORN) of the mandible quantitatively. The aim was to investigate the risk factors, including different modalities of radiotherapy, for developing mandibular ORN in patients undergoing marginal mandibulectomy and postoperative radiotherapy. METHODS: Between January 2006 and December 2012, 167 subjects who underwent marginal mandibulectomy and postoperative radiotherapy with different modalities were enrolled. The association of ORN with mandibular bone measurements and patient variables was analyzed, and a nomogram was established. RESULTS: Fifteen (8.98%) of the 167 patients developed ORN during the follow-up period, and ORN was significantly associated with diabetes mellitus (DM), body mass index (BMI), remaining bone height, remaining bone height to original bone height ratio, resected bone height to original bone height ratio, and mandibular dose (P: < 0.001, 0.004, 0.042, 0.018, 0.010, 0.020, respectively). Interestingly, the risk of ORN had no significant difference between conformal and intensity modulation radiation therapy (P = 0.407). Multivariate analysis revealed that DM and resected bone height to original bone height ratio ≥ 50% were independent risk factors for postoperative ORN. A nomogram consisting of BMI, DM, resected bone height to original bone height ratio, mandibulotomy, and mandibular dose for predicting the ORN-free probability was established; and the c-index of the nomogram for ORN status was 0.803. CONCLUSION: A nomogram based on the risk factors was plotted to strengthen the prediction of ORN quantitatively. Surgeons should be more discrete regarding the treatment plan for patients with higher probability of ORN. LEVEL OF EVIDENCE: 3b Laryngoscope, 130:101-107, 2020.

Chondrolipoma of the toe.

Chondrolipoma is a rare benign mesenchymoma composed of mature cartilage and adipose tissue. We present a 71-year-old man with a chondrolipoma of the great toe. On histological examination, the tumor contained both mature fat cells and chondrocytes. To our knowledge, this is the first report of a chondrolipoma on the toe. This case contributes to better awareness of an extremely rare lesion of the distal lower limb.

Bipedicle flap reconstruction for complex longitudinal dorsal tissue defects of the digits.

Achieving coverage after digital injury is crucial, because simple skin defects can expose essential structures such as tendons or bones. This is particularly true on the dorsal surfaces of the digits, where the skin provides the only protection for the tendons. However, longitudinal skin defects of the digit have not been specifically identified in the literature and there have been few reports focusing on longitudinal dorsal skin defects. Here we report on the use of a bipedicle flap for reconstruction of complex longitudinal dorsal tissue defects of the digits, including those associated with tendon or bone damage.

A Comparison of Conventional Collagen Sponge and Collagen-Gelatin Sponge in Wound Healing.

The objective of this study was to compare the effectiveness of the collagen-gelatin sponge (CGS) with that of the collagen sponge (CS) in dermis-like tissue regeneration. CGS, which achieves the sustained release of basic fibroblast growth factor (bFGF), is a promising material in wound healing. In the present study, we evaluated and compared CGSs and conventional CSs. We prepared 8 mm full-thickness skin defects on the backs of rats. Either CGSs or CSs were impregnated with normal saline solution (NSS) or 7 µg/cm(2) of bFGF solution and implanted into the defects. At 1 and 2 weeks after implantation, tissue specimens were obtained from the rats of each group (n = 3, total n = 24). The wound area, neoepithelial length, dermis-like tissue area, and the number and area of capillaries were evaluated at 1 and 2 weeks after implantation. There were no significant differences in the CGS without bFGF and CS groups. Significant improvements were observed in the neoepithelial length, the dermis-like tissue area, and the number of newly formed capillaries in the group of rats that received CGSs impregnated with bFGF. The effects on epithelialization, granulation, and vascularization of wound healing demonstrated that, as a scaffold, CGSs are equal or superior to conventional CSs.

Lymphatic Territories (Lymphosomes) in Swine: An Animal Model for Future Lymphatic Research.

BACKGROUND: The swine is a common preclinical large-animal model for medical research because of the resemblance of its tissue structures to those of humans. However, the lymphatic system in swine is poorly understood. The authors investigated the lymphatic system and defined territories (lymphosomes) in swine using the microinjection technique. METHODS: Six swine (two male and four female 17.5- to 50-kg Sus domesticus) were used. Real-time indocyanine green fluorescence lymphography was performed in four live swine. After the animals were killed, the authors injected a radiocontrast mixture consisting of barium sulfate and hydrogen peroxide with red acrylic dye directly into lymphatic vessels in six swine carcasses. Courses of the lymphatic vessel were analyzed radiographically. The lymphatic vessels were dissected meticulously and chased until they connected to the first-tier (sentinel) lymph node. This procedure was repeated throughout the body until all the relationships between the lymphatic vessels and lymph nodes were defined. RESULTS: The authors successfully mapped the superficial lymphatic vessels and their corresponding lymph nodes. Indocyanine green fluorescence lymphography and subsequent radiography revealed that the swine lymphatic system contained seven lymphosomes: parotid, mandibular, dorsal cervical, ventral cervical, subiliac, inguinal, and popliteal territories. Of note, no lymph nodes existed in the superficial axillary region. CONCLUSIONS: The swine could be a useful large-animal model for lymphatic research because of the anatomical consistency of the lymphosomes among animals and the sizable lymphatic vessels. However, swine lack the superficial axillary lymph node found in humans, suggesting that swine may not be a good model for breast cancer-related lymphedema.

Simultaneous Bilateral Submental Lymph Node Flaps for Lower Limb Lymphedema Post Leg Charles Procedure.

We summarize the case of a 59-year-old woman with left lower limb lymphedema for 4 years post hysterectomy, pelvic lymph node dissection, radiation therapy, and chemotherapy for endometrial cancer. She underwent the Charles procedure on her left leg 2 years before being referred to our hospital and developed several cellulitis episodes and progressive lymphedema affecting her left toes and thigh. Bilateral vascularized submental lymph node flaps were transferred to her left ankle and thigh, respectively. After a 5-month follow-up, the leg became softer and lighter without relapsing cellulites, and the circumferential reduction rates at 15 cm above knee, 15 cm below knee, and 10 cm above ankle were 23.3%, 50%, and 22.2%, respectively. The patient was satisfied with the functional recovery and discontinued use of compression garment postoperatively.

Challenging a traditional paradigm: 12-year experience with autologous free flap breast reconstruction for inflammatory breast cancer.

BACKGROUND: Inflammatory breast cancer is a rare but aggressive breast cancer with an overall poor prognosis. Traditionally, reconstruction has not been offered, because of poor long-term survival, the need for multimodality treatment, and complex treatment sequencing. The authors examined the safety and feasibility of free flap breast reconstruction for inflammatory breast cancer. METHODS: A retrospective analysis of all patients who underwent reconstruction for inflammatory breast cancer from January of 2000 to December of 2012 was conducted. RESULTS: Of 830 inflammatory breast cancer patients, 59 (7.1 percent; median age, 48 years; range, 27 to 65 years) underwent free flap reconstruction. All patients received chemotherapy and radiation therapy. Most patients (n = 52) underwent delayed reconstruction. Five patients with a history of prior partial mastectomy and irradiation developed inflammatory breast cancer and underwent immediate reconstruction following completion mastectomy. Two others underwent immediate chest wall and breast reconstruction following resection. Thirteen patients underwent bilateral reconstruction, and seven required a bipedicled abdominal flap for the unilateral mastectomy defect. Thirty-seven patients (62.7 percent) required revision of the reconstructed breast, and 29 (49.2 percent) had a contralateral balancing procedure to optimize symmetry. Complications occurred in 21 patients (35.6 percent), with one total flap loss (1.7 percent). The median length of follow-up was 43.9 months; 49 patients (83.1 percent) were alive without evidence of recurrent disease. CONCLUSIONS: Autologous free flap breast reconstruction can be performed safely in inflammatory breast cancer patients, with acceptable complication rates and without an increased risk for flap loss. Inflammatory breast cancer should not preclude free flap breast reconstruction. CLINICAL QUESTION/LEVEL OF EVIDENCE: Therapeutic, IV.

Overview of lymph node transfer for lymphedema treatment.

SUMMARY: Recent articles report that surgery can effectively treat secondary lymphedema. Lymphovenous anastomosis with supermicrosurgery technique has become popular for surgical intervention for lymphedema and has an advantage of minimal morbidity. Lymphovenous anastomosis is effective for treating early-stage lymphedema before fibrosis occurs but has limited outcomes in advanced lymphedema. Lymph node transfer is an emerging physiologic surgical treatment for lymphedema that shows promise. The mechanisms of lymph node transfer have been discordant between publications. However, initial reports encourage surgeons to use lymph node transfer to treat lymphedema patients. The authors review the literature on lymph node transfer and discuss its possible mechanisms and its role in lymphedema treatment.

Adipogenesis using human adipose tissue-derived stromal cells combined with a collagen/gelatin sponge sustaining release of basic fibroblast growth factor.

We have developed a collagen/gelatin sponge (CGS) that can provide a sustained release of basic fibroblast growth factor (bFGF). In our previous study, it was shown that CGS impregnated with the appropriate dosage of bFGF accelerates dermis-like tissue formation two or three times earlier than an existing collagen sponge. In this study, adipogenesis was evaluated using CGSs disseminated with adipose tissue-derived stem cells (ASCs). Human ASCs were primarily isolated from human adipose tissue that was obtained during breast cancer surgery with informed consent at Kyoto University Hospital. ASCs were isolated from collagenase digests of adipose tissue. ASCs were labelled with PKH26. CGSs (8 mm diameter × 3 mm thickness) were impregnated with bFGF (0.1, 1, 7, 14 µg/cm(2) ) or normal saline solution. Then the labelled cells were disseminated (passage 3) on CGSs at a seeding density of 1 × 10(5) cells/cm(2) and implanted into the back subcutis of nude mice. Six weeks after implantation, adipogenesis at the administered site was evaluated. Immunohistological staining with von Willebrand factor (vWf) was performed to evaluate newly formed capillaries. Newly formed adipose tissue was observed macroscopically and histologically in all groups. The weight and area of regenerated adipose tissue were largest in the 1 µg/cm(2) bFGF group. Under a fluorescent microscope, newly formed adipose tissue in the bFGF-administered group was PKH-positive. These findings show that ASCs differentiated and formed adipose tissue. In this study, we showed that our CGSs impregnated with bFGF could be used as scaffolds with ASCs for adipogenesis.

Efficacy of the controlled release of concentrated platelet lysate from a collagen/gelatin scaffold for dermis-like tissue regeneration.

INTRODUCTION: A collagen/gelatin scaffold (CGS) can provide a sustained release of basic fibroblast growth factor (bFGF), which promotes wound healing. However, bFGF is approved for clinical use in Japan and China only. One potential alternative to bFGF is platelet lysate (PL), a safe and easily attainable source of a wide range of growth factors necessary for tissue repair. In the present study, we investigated the use of PL with CGS to repair wounds and identified the optimal concentration of PL for wound healing. MATERIALS AND METHODS: We generated PL from concentrated platelets harvested from individual healthy donors. We measured growth factors in PL. Transforming growth factor (TGF)-ß1, platelet-derived growth factor (PDGF)-BB, vascular endothelial growth factor (VEGF), and bFGF were selected because they were the major growth factors contained in platelets and showed the greatest ability to enhance the maturation of newly formed blood vessels. Pieces of CGS impregnated with PL solution (×1, ×2, ×3, or ×4 concentrated) or normal saline solution (NSS) were implanted into full-thickness skin defects on the backs of mice. We evaluated the wound area, neoepithelium length, and total area of newly formed capillaries in the implanted CGS. RESULTS: Our release experiments revealed that PDGF-BB and TGF-ß1 were released from CGS incubated with collagenase in a sustained manner. CGS impregnated with concentrated PL was more effective than CGS impregnated with NSS in all evaluated items. The ×2 concentrated PL accelerated wound healing and enhanced cell proliferation and vessel growth in granulation tissue. CONCLUSION: Our findings indicate that CGS can bind to TGF-ß1 and PDGF-BB and release these growth factors in a sustained manner. ×2 concentrated PL-impregnated CGS accelerates the formation of dermis-like tissue.