Shaping a Flap Using a Bioabsorbable Mold-A Preliminary Report.

BACKGROUND: We previously reported that good surgical outcomes can be obtained with breast mold made by 3-dimensional printing. However, detailed breast shape is often difficult to create. Accordingly, we aimed to determine whether transplanting a flap and bioabsorbable mold in vivo would yield better results by retaining the flap shape inside the mold during the scar formation period. METHODS: Vascularized adipose flaps were elevated in the bilateral inguinal region of male Sprague-Dawley rats (n = 7). A cone-shaped, bioabsorbable mold (LactoSorb mesh) was created using a template. On the experimental side, the flap was inserted into the mold and fixed. On the control side, a conical flap was created using absorbable sutures, based on a template. RESULTS: The flaps were harvested 3 months postoperatively, and flap volume, base area, and projection were measured with 3-dimensional imaging. Volume and base area on the mold side tended to be smaller than those on the control side (P = 0.18 and 0.13, respectively) and close to the values of the template. In addition, the ratio of projection and base area value was significantly greater on the mold side than on the control side (P = 0.04). Histology revealed little inflammatory cell invasion, and scar tissue thickness around the flap showed no significant difference between the 2 groups (P = 0.76). CONCLUSIONS: This study demonstrated that soft-tissue morphology can be controlled to some extent with a bioabsorbable mold. Its clinical application in breast reconstruction requires further investigation.

Endothelial cell-derived endothelin-1 is involved in abnormal scar formation by dermal fibroblasts through RhoA/Rho-kinase pathway.

Hypertrophic scars and keloids are characterized by excessive dermal deposition of extracellular matrix due to fibroblast-to-myofibroblast differentiation. Endothelin-1 (ET-1) is primarily produced by vascular endothelial cells and plays multiple roles in the wound-healing response and organ fibrogenesis. In this study, we investigated the pathophysiological significance of ET-1 and involvement of RhoA, a member of the Rho GTPases, in hypertrophic scar/keloid formation. We found that ET-1 expression on dermal microvascular endothelial cells (ECs) in hypertrophic scars and keloids was higher than that in normal skin and mature scars. We also confirmed that ET-1 induced myofibroblast differentiation and collagen synthesis in cultured human dermal fibroblasts through the RhoA/Rho-kinase pathway. Finally, since hypertrophic scar/keloid formation was most prominent in areas exposed to mechanical stretch, we examined how mechanical stretch affected ET-1 secretion in human dermal microvascular ECs, and found that mechanical stretch increased ET-1 gene expression and secretion from ECs. Taken together, these results suggest that dermal microvascular ECs release ET-1 in response to mechanical stretch, and thereby contribute to the formation of hypertrophic scars and keloids through the RhoA/Rho-kinase pathway.

Aesthetic outcomes of inframammary fold recreation in two-stage, implant-based, breast reconstruction.

BACKGROUND: When the inframammary fold (IMF) is excised in mastectomy procedures for oncologic reasons, it must be recreated to restore a natural breast shape. Despite refinements in surgical techniques, postoperative loss of a well-defined IMF can occur. This study aimed to assess the outcomes of IMF recreation after two-stage, implant-based breast reconstruction. METHODS: We retrospectively reviewed 75 consecutive patients who underwent unilateral, two-stage, implant-based breast reconstruction between 2013 and 2015 at the authors' institution. Among them, IMF recreation was performed in 37 patients through a modified Nava's internal method. Aesthetic outcomes of the recreated IMFs were evaluated by observer assessment of two criteria, and critical factors affecting IMF outcomes were also analyzed. RESULTS: We found that contralateral breast ptosis (p < 0.05) and lack of postmastectomy radiotherapy (PMRT, p < 0.01) were significant predictors of better IMF outcomes. Nipple-sparing mastectomy and skin-sparing mastectomy resulted in better IMF outcomes, as compared with non-skin-sparing mastectomy (p < 0.05 for each), while no significant difference was observed between them in patients who did not undergo PMRT (p = 0.19). Similarly, larger implant volume, but not projection of implant, was a predictor of better IMF outcomes when limited to patients who did not undergo PMRT (p < 0.05). Age, body mass index, timing of reconstruction, and extent of overexpansion had no significant effect on IMF outcomes. CONCLUSIONS: Based on these critical factors, the shape of the reconstructed breast and the need for reshaping the contralateral breast can be predicted. Special attention should be paid to patients with non-skin-sparing mastectomy and PMRT. When these patients desire a medium- to large-sized ptotic breast, conversion to autologous reconstruction can achieve symmetrical breast reconstruction.

Differentiated adipose-derived stem cells promote the recovery of nociceptor function in rats.

The loss of nociceptive function in the skin because of trauma or surgery can impair the quality of life. The recovery of nociceptor function is mediated by two different axonal responses: nerve growth factor (NGF)-dependent collateral sprouting of undamaged nerves and NGF-independent regeneration of damaged nerves. We reported previously that adipose-derived stem cells (ASCs) can transdifferentiate into Schwann cell (SC)-like cells (dASCs) and that transplantation of dASCs increases axonal density in skin flaps. In the present study, we used an animal model that allowed for the individual assessment of collateral sprouting and regeneration. In-vitro differentiation of ASCs to dASCs significantly increased the production of NGF and brain-derived neurotrophic factor (BDNF) to levels comparable with SCs. In-vivo experiments showed that dASC and SC transplantation significantly increased the area of the mechano-nociceptive field in both collateral sprouting and regeneration models, whereas ASC transplantation exerted no significant effect. Antibody blocking experiment showed that these effects of dASC transplantation in the regeneration model were partly mediated by BDNF. Interestingly, the final areas of nociceptive fields between the two experimental models did not differ significantly for any treatment condition. These results indicate that dASC transplantation differentially facilitates collateral sprouting and axonal regeneration by delivering NGF and other neurotrophic factors (e.g. BDNF), respectively. Although there is a limit to nociceptive field enlargement irrespective of axonal response, dASC transplantation could present a new approach for improving nociceptive function in denervated skin.

Differential Reanimation of the Upper and Lower Face Using 2 Interpositional Nerve Grafts in Total Facial Nerve Reconstruction.

Radical parotidectomy often results in complex facial nerve defects involving the main nerve trunk and multiple distal nerve branches. Although cable nerve grafting often leads to good nerve regeneration, severe synkinesis due to aberrant axonal regrowth is inevitable. In such situations, the use of 2 motor sources to differentially reanimate the upper and lower face could minimize synkinesis. Here we describe a method of total facial nerve reconstruction in which the upper and lower face are differentially reconstructed with the hypoglossal nerve and facial nerve, respectively, using 2 interpositional nerve grafts. Reconstruction of the lower face with the facial nerve restored voluntary and coordinated animation, and reconstruction of the upper face with the hypoglossal nerve restored frontalis muscle tone and eye closure. These results suggest that our method could serve as an alternative to conventional techniques that use only the facial or hypoglossal nerve.

Effects of Subcutaneous versus Submuscular Tissue Expander Placement on Breast Capsule Formation.

In autologous breast reconstruction, skin envelope reconstruction is especially important given the flexibility of new breast parenchyma. Our experience suggests a better control of breast shape with subcutaneous tissue expander (TE) placement compared with submuscular TE placement. We speculate that capsule formation might be different in subcutaneous TE placement compared with submuscular TE placement. To elucidate this hypothesis, we collected capsules formed around the TE in two-stage breast reconstruction patients and evaluated differences in histology and capsule wall thickness between subcutaneous (n = 7) and submuscular (n = 8) TE placement. Our findings show that subcutaneous TE placement results in thinner capsule formation with low vascularity when compared with submuscular TE placement (354 ± 96 µm and 589 ± 92 µm, respectively; P < 0.001). Because thin connective tissue can reduce postoperative shrinkage of the skin envelope, it would be beneficial to predict and control the shape of reconstructed breast. Although further study is needed, differences in vascularity between subcutaneous tissue and muscle might affect the thickness of capsules.

Adipose-derived stem cells protect against endoneurial cell death: Cell therapy for nerve autografts.

BACKGROUND: One of the major problems with nerve grafts is that the survival of a graft segment, including endoneurial Schwann cells (SCs), is uncertain. We investigated whether the survival of nerve grafts is improved when adipose-derived stem cells (ASCs) are incorporated into the grafts. METHODS: To examine the cell-protective effects of ASCs on SCs in vitro, we used an indirect coculture system. In vivo effects of the incorporation of ASCs into grafts were examined using a graft model in the rat common peroneal nerve. Grafts were entubulated to isolate them from the surrounding tissues, mimicking the clinical conditions of a poorly vascularized recipient bed. Thirty-six Lewis rats were divided into three groups, i.e., nerve graft only, entubulated nerve graft, and entubulated nerve graft + ASC transplantation. In each group, four rats and eight rats were used for short-term (10 days) and long-term (12 weeks) follow-up study, respectively. RESULTS: After 24 hours of serum deprivation, the numbers of 7-aminoactinomycin D, and TUNEL-positive SCs significantly decreased when indirectly cocultured with ASCs (P < 0.01). When ASCs were transplanted to the epineurial layer of the grafts, the number of endoneurial TUNEL-positive cells decreased significantly, as compared with grafts without ASCs, at 10 days postoperatively (P < 0.05). Postoperative walking track analysis showed that the ASC-transplanted grafts showed significantly faster function recovery, as compared with grafts without ASCs (P < 0.05). CONCLUSION: These results suggest that nerve autografts + ASC therapy could offer a new approach to obtaining optimal outcomes after peripheral nerve injury.

DIEP Flap Breast Reconstruction Using 3-dimensional Surface Imaging and a Printed Mold.

Recent advances in 3-dimensional (3D) surface imaging technologies allow for digital quantification of complex breast tissue. We performed 11 unilateral breast reconstructions with deep inferior epigastric artery perforator (DIEP) flaps (5 immediate, 6 delayed) using 3D surface imaging for easier surgery planning and 3D-printed molds for shaping the breast neoparenchyma. A single- or double-pedicle flap was preoperatively planned according to the estimated tissue volume required and estimated total flap volume. The DIEP flap was then intraoperatively shaped with a 3D-printed mold that was based on a horizontally inverted shape of the contralateral breast. Cosmetic outcomes were assessed as satisfactory, as confirmed by the postoperative 3D measurements of bilateral breasts. We believe that DIEP flap reconstruction assisted with 3D surface imaging and a 3D-printed mold is a simple and quick method for rebuilding a symmetric breast.

Covering implantable left ventricular assist device (DuraHeart) with free flap.

Severe donor shortage in Japan makes the waiting period for heart transplantation extremely long and the left ventricular assist devices (LVADs) are often used for bridge-to-transplant. We present three cases of infected and exposed DuraHeart LVAD system treated with free flaps. Four free flaps (two latissimus flaps and two anterolateral thigh flaps) were transferred using the right internal thoracic vessels or left deep inferior epigastric vessels as recipients. The potential significance of the continuous low pressure blood flow generated by the LVAD system on microvascular patency has not been previously reported. All flaps survived and worked efficiently to control the infection and cover the devices. Heart transplantation was conducted in the two of three patients. Free flap transfer is an efficient treatment for the patients with infected and exposed implantable LVAD.

Breast Reconstruction following Breast-conserving Surgery with a Subcutaneous Tissue Expander and Latissimus Dorsi Flap.

SUMMARY: Corrective surgery following breast-conserving surgery is generally challenging due to severe fibrosis induced by postoperative radiotherapy. Although use of the latissimus dorsi myocutaneous flap offers a safe and reliable option, exposure of the skin paddle to the skin surface is often inevitable to achieve correction of nipple-areola complex malposition, leaving conspicuous, patchwork-like scars on the breast. In this report, we describe a 2-stage procedure using a subcutaneous tissue expander and the latissimus dorsi myocutaneous flap for the correction of both nipple-areola complex malposition and breast volume without skin paddle exposure. Although careful observation is necessary during skin expansion, this technique could offer an alternative option for patients undergoing corrective surgery following breast-conserving surgery.

The role of latissimus dorsi myocutaneous flaps in secondary breast reconstruction after breast-conserving surgery.

OBJECTIVE: Secondary reconstruction after breast-conserving surgery is generally challenging because of the nature of irradiated tissue. The aim of this study was to validate the use of latissimus dorsi myocutaneous (LDM) flaps for secondary breast reconstruction after breast-conserving surgery. METHODS: Fifteen consecutive patients who underwent secondary reconstruction with an LDM flap after breast-conserving surgery were included in the study. The esthetic outcome in comparison with the contralateral breast was evaluated by observer assessments consisting of 7 criteria. In addition to comparing pre- and postoperative scores for each criterion, factors affecting overall esthetic outcome were analyzed. RESULTS: There was no major recipient- or donor-related complication. In 13 patients, the skin paddle of the LDM flap was exposed to the skin surface. In all patients, overall esthetic scores increased postoperatively. Age, period between breast-conserving surgery and LDM flap, body mass index, or preoperative breast size did not affect the overall esthetic outcome. Tumors in the lower quadrants tended to result in poorer esthetic scores, especially in breast shape and scar (P = .04 and .02, respectively). CONCLUSIONS: Given their high vascularity and moderate flap volume, LDM flaps could be a reliable option for secondary breast reconstruction after breast-conserving surgery. Although exposure of skin paddle to the skin surface is inevitable in most cases, esthetic improvement could be achieved, including the breast scar. On the contrary, immediate reconstruction would certainly be more desirable, especially in cases of tumors in the lower quadrants.

Differentiated Adipose-derived Stem Cells Promote Reinnervation of Rat Skin Flaps.

BACKGROUND: Sensory recovery of skin flaps is generally poor unless they are elevated as an innervated flap. The aim of this study was to elucidate if Schwann cell (SC)-like cells differentiated from adipose-derived stem cells (ASCs) could improve the cutaneous nerve regeneration in skin flaps. METHODS: Microvascular island groin flaps were elevated bilaterally in 32 Lewis rats. On the right flap, the epigastric nerve was resected and ligated (noninnervated flap), and on the left flap, the nerve was crushed (innervated flap). ASCs, SC-like cells differentiated from ASCs (dASCs), SCs, or vehicle were simultaneously injected to the dermal and hypodermal layers of flap. After 20 weeks, the reinnervation pattern of flap was assessed immunohistochemically using a neuronal marker, PGP9.5. RESULTS: dASC cultures produced significantly higher amount of nerve growth factor and brain-derived neurotrophic factor compared with ASC cultures (P < 0.01), and the level was comparable to that of SC cultures. Although a long-term survival of the transplanted cells was not found, dASCs and SCs significantly increased reinnervation density in the periphery of both types of flaps (P < 0.05), and this effect was more pronounced in noninnervated flaps. On the other hand, ASC transplantation showed no statistically significant effect on the peripheral reinnervation (P > 0.05). In the center of flap, there was no statistically significant increase in reinnervation density in all groups irrespective of flap innervation (P > 0.05). CONCLUSIONS: dASCs could improve flap reinnervation by 2 mechanisms: First, neurotrophic factors produced by dASCs facilitated regrowth of cutaneous axons from the surroundings of flap. Second, nerve growth factor released by dASCs induced the collateral sprouting of undamaged axons in adjacent tissues. In addition to the use of innervated flaps, dASC transplantation therapy could be a new approach to improve the sensory recovery of skin flaps.

Extended thymectomy via videothoracoscopy-assisted stepwise-access sternotomy.

A method of videothoracoscopy-assisted extended thymectomy procedure performed through a movable small access window is introduced. The access window can be moved stepwise and longitudinally alongside full sternotomy to be upon the dissection site. The majority of the thymectomy procedure can be directly viewed and operated from the moving window. However, partial and complete thoracoscopic maneuvers are required for dissection of the lateral-most region near the phrenic nerve and the upper poles of the thymus, respectively.

Off-pump coronary artery bypass grafting as re-do surgery in two cases in which the right gastroepiploic artery was grafted to the right coronary artery.

Transdiaphragmatic off-pump coronary artery bypass grafting (OPCAB) to the right coronary artery, is an effective way to reduce the risks of second bypass surgery as well as the risk of graft injury after coronary artery bypass grafting (CABG). We report two cases of successful OPCAB as re-do surgery in which the right gastroepiploic artery (RGEA) was grafted to the right coronary artery. The first case was a 58-year-old woman, who underwent CABG 10 years ago. OPCAB (RGEA to right coronary artery) was performed since myocardial perfusion scintigraphy revealed ischemia in the inferior wall. The second case was a 67-year-old man who had hypertension, hyperlipidemia, peripheral arterial disease, and was undergoing dialysis (for 6 years). Six years previously, he developed a mycotic aneurysm of the right coronary artery and underwent open-heart surgery. He often had episodes of angina at night or during dialysis, and then developed congestive heart failure and was hospitalized. Since ischemia was considered to be in the inferior wall, the RGEA was grafted to the right coronary artery.

Inverted intercostal hernia of soft tissue manifested as slow-growing chest wall tumor after thoracotomy.

An 80-year-old woman had an asymptomatic chest wall tumor. She had undergone thoracotomy to treat a benign lesion 11 years previously. Chest computed tomography revealed a convex lens-shaped mass 7 cm in diameter in the chest wall. Positron emission tomography demonstrated mild accumulation of F-deoxyglucose. We performed an exploratory thoracotomy; however, no mass lesion was found. Therefore, we thought that the soft tissue of the back was drawn into the pleural cavity through the widened intercostal space during the previous thoracotomy. We simply aligned the ribs using heavy surgical sutures. The patient has experienced good recovery, with no recurrence since the surgery.