Free Flap Survival with External Jugular Vein as a Detour Due to Internal Jugular Vein Thrombosis.

In head and neck reconstructions, venous anastomosis of the free flap to the internal jugular vein system is a common procedure. However, in some cases, postoperative complications such as internal jugular vein thrombosis can occur. In this report, we present a case where postoperative internal jugular vein thrombosis was identified after venous anastomosis of the free flap to the internal jugular vein system. In this case, preserving the external jugular vein allowed for retrograde flow of venous blood in the internal jugular vein to enter the external jugular vein, serving as an alternative drainage pathway. This finding highlights the potential benefits of preserving the external jugular vein in head and neck surgery involving free flap venous anastomosis to mitigate the adverse effects of internal jugular vein thrombosis. Further investigations are warranted to better understand the underlying mechanisms and optimize surgical approaches for improved patient outcomes.

Schlieren Phenomenon for Identification of Lymphorrhea Point.

Surgical invasion of the lymphatic system can lead to lymphorrhea. Lymphorrhea is first treated conservatively, but is often refractory and subsequently treated surgically. In surgery, it is difficult to identify the lymphatic leak points visually. In this study, we observed the schlieren phenomenon based on the difference in the refractive index between glucose solution and lymph fluid, and were able to easily identify the site of the lymphatic leakage in real time and treat lymphorrhea.

Personal Computer-Based Cephalometric Landmark Detection With Deep Learning, Using Cephalograms on the Internet.

BACKGROUND: Cephalometric analysis has long been, and still is one of the most important tools in evaluating craniomaxillofacial skeletal profile. To perform this, manual tracing of x-ray film and plotting landmarks have been required. This procedure is time-consuming and demands expertise. In these days, computerized cephalometric systems have been introduced; however, tracing and plotting still have to be done on the monitor display. Artificial intelligence is developing rapidly. Deep learning is one of the most evolving areas in artificial intelligence. The authors made an automated landmark predicting system, based on a deep learning neural network. METHODS: On a personal desktop computer, a convolutional network was built for regression analysis of cephalometric landmarks' coordinate values. Lateral cephalogram images were gathered through the internet and 219 images were obtained. Ten skeletal cephalometric landmarks were manually plotted and coordinate values of them were listed. The images were randomly divided into 153 training images and 66 testing images. Training images were expanded 51 folds. The network was trained with the expanded training images. With the testing images, landmarks were predicted by the network. Prediction errors from manually plotted points were evaluated. RESULTS: Average and median prediction errors were 17.02 and 16.22 pixels. Angles and lengths in cephalometric analysis, predicted by the neural network, were not statistically different from those calculated from manually plotted points. CONCLUSION: Despite the variety of image quality, using cephalogram images on the internet is a feasible approach for landmark prediction.

An Attempt to Make Platelet Rich Fibrin from Bone Marrow Aspirate.

INTRODUCTION: Platelet Rich Fibrin (PRF) was developed as a new generation of platelet concentration from peripheral blood. Method to make PRF is simple. It is easy to handle with its moderate firmness. Histologically, platelets and nucleated cells are packed along the yellow-red border. Bone marrow aspirate contains bone marrow cells that potentially work for tissue regeneration, and platelets which contain growth factors. The specific gravities of them are comparable. It implies that, if it is possible to make PRF from bone marrow aspirate, then high concentration of platelets and bone marrow cells can be obtained simultaneously by taking out yellow-red interface of it. AIM: To find out a method to make PRF from bone marrow aspirate. MATERIALS AND METHODS: Iliac crest of rabbits were punctured and aspirated with or without anti-coagulant, under general anaesthesia. The bone marrow aspirate was centrifuged in glass tubes. For the bone marrow aspirate taken with anti-coagulant, calcium chloride was added just before centrifugation. Products were taken out and observed grossly. The products were fixed with formaldehyde and observed histologically. RESULTS: Coagulated gels with two-toned colour were obtained by all methods. In the gels without anti-coagulant, interfaces between two colours were obscure. Histologically, platelets and nucleated cells scattered as clusters. Filtering caused haemolysis and reduced the yield of the product. With the aspirate taken with anti-coagulant, platelets and nucleated cells formed a band along the interface. CONCLUSION: PRF can be made from bone marrow aspirate by adding anti-coagulant in aspiration and reversed with calcium chloride just before centrifugation.

Free flap transfer reconstruction in managing tongue carcinoma during pregnancy.

Malignant oral cancers do not commonly occur in pregnant women. But when they do, the presence of a foetus and maternal physiological changes complicate and limit the treatment options. Risk benefit assessment and balancing of them are always important. A 33-year-old woman, who was 25 weeks pregnant, presented with a squamous cell carcinoma on her tongue. She was clinically staged II (T2, N0 and M0). Discussions between the patient, surgical teams and obstetricians agreed to continue her pregnancy while managing the tumour. Hemi-glossectomy and ipsilateral neck dissection was performed. Free antero-lateral thigh flap was transferred to reconstruct the tongue defect, successfully. The patient gave birth to a healthy baby afterward. She is tumour free for 6 years. Free flap reconstruction can be an option, even if the patient is pregnant.

A new rabbit model of impaired wound healing in an X-ray-irradiated field.

Radiation is an important therapy for cancer with many benefits; however, its side effects, such as impaired wound healing, are a major problem. While many attempts have been made to overcome this particular disadvantage, there are few effective treatments for impaired wound healing in an X-ray-irradiated field. One reason for this deficiency is the lack of experimental models, especially animal models. We have previously reported a mouse model of impaired wound healing in which the irradiation area was restricted to the hindlimbs. In this mouse model, due to the size of the animal, a diameter of five millimeters was considered the largest wound size suitable for the model. In addition, the transplanted cells had to be harvested from other inbred animals. To investigate larger wounds and the impact of autologous specimen delivery, a rabbit model was developed. Rabbits were kept in a special apparatus to shield the body and hindlimbs while the irradiation field was exposed to radiation. Six weeks after irradiation, a 2 x 2 cm, full-thickness skin defect was made inside the irradiation field. Then, the wound area was observed over time. The wound area after irradiation was larger than that without irradiation at all time points. Both angiogenesis and collagen formation were reduced. For further study, as an example of using this model, the effect of autologous platelet-rich plasma (PRP) was observed. Autologous PRP from peripheral blood (pb-PRP) and bone marrow aspirate (bm-PRP) was processed and injected into the wounds in the irradiated field. Two weeks later, the wounds treated with bm-PRP were significantly smaller than those treated with phosphate buffer vehicle controls. In contrast, the wounds treated with pb-PRP were not significantly different from the controls. This rabbit model is useful for investigating the mechanism of impaired wound healing in an X-ray-irradiated field.

Congenital lipomatous tumour, presented as a polypoidal projection on upper eyelid.

A Japanese baby was born with a polypoidal projection with hair, on the lateral corner of upper eyelid. The tumour had extent to bulbar sub-conjunctival area. He presented no other malformation nor pathological symptoms. There was no sign of association with Goldenhar, hemifacial macrosomia, epidermal nevus or linear nevus sebaceous syndromes. The tumour was resected at his age of 4 months. The ocular conjunctiva was incised but not excised. Histopathologically, it was mainly consisted of multi-lobuled mature adipose tissue, dense fibrous tissue was observed at the centre of mass, assumed to be the link of palpebral tarsal plate to lateral canthal ligament. As for the location and component, the tumour was diagnosed as a lipomatous hamartoma. Detached tarsal plate was reattached to the lateral canthal ligament. Satisfactory result was achieved aesthetically and functionally. Congenital lipomatous hamartoma, with protuberant appendage appearance on eyelid, without syndromic association, is presented.

Bilateral Maxillary Reconstruction Using Fibular Flap in Bisphosphonate-related Osteonecrosis.

Recent reports have shown successful transfer of vascularized fibular flap in bisphosphonate-induced mandibular osteonecrosis. We present a case of a 50-year-old patient who presented with bisphosphonate-related osteonecrosis of bilateral maxilla, which is reconstructed using a fibular flap.

An augmented reality system in lymphatico-venous anastomosis surgery.

Indocyanine green lymphography, displayed as infrared image, is very useful in identifying lymphatic vessels during surgeries. Surgeons refer the infrared image on the displays as they proceed the operation. Those displays are usually placed on the walls or besides the operation tables. The surgeons cannot watch the infrared image and the operation field simultaneously. They have to move their heads and visual lines. An augmented reality system was developed for simultaneous referring of the infrared image, overlaid on real operation field view. A surgeon wore a see-through eye-glasses type display during lymphatico-venous anastomosis surgery. Infrared image was transferred wirelessly to the display. The surgeon was able to recognize fluorescently shining lymphatic vessels projected on the glasses and dissect them out.

Growth Factor Measurement and Histological Analysis in Platelet Rich Fibrin: A Pilot Study.

OBJECTIVE: The aim of this study was to compare growth factor amount contained in platelet rich fibrin (PRF) and compare with that in platelet rich plasma (PRP), and in whole blood. And also to investigate distribution of growth factors and cellular components in PRF. MATERIALS AND METHODS: PRF and PRP were obtained from the same sample of peripheral blood. Extraction of proteins were done with lysis buffer, accompanied by freeze and thaw procedures. Concentration of two representative growth factors in platelets: platelet derived growth factor (PDGF) and transforming growth factor beta (TGF-ß), were measured with enzyme-linked immunosorbent assay (ELISA). PRF was cut into three parts: (top, middle and bottom), and growth factor concentration was measured respectively. Paraffin embedded section of PRF was observed with Giemsa stain. Immuno-histochemical analysis with anti-PDGF and anti-TGF-ß antibodies was also conducted. RESULTS: The growth factor levels in PRF was higher than in peripheral blood and comparable to those in PRP. Growth factor levels in bottom part of PRF was much higher than in top and middle part. Microscopically, platelets and mono-nucleated cells were concentrated just above the yellow-red interface. Poly-nucleated cells were concentrated below the interface. CONCLUSION: The growth factors were surely concentrated in PRF. This result can support basis of good clinical outcomes. For effective application of PRF, the knowledge that growth factors and cells are not equally distributed in PRF should be utilized.

Hypertrophic scar contracture is mediated by the TRPC3 mechanical force transducer via NFkB activation.

Wound healing process is a complex and highly orchestrated process that ultimately results in the formation of scar tissue. Hypertrophic scar contracture is considered to be a pathologic and exaggerated wound healing response that is known to be triggered by repetitive mechanical forces. We now show that Transient Receptor Potential (TRP) C3 regulates the expression of fibronectin, a key regulatory molecule involved in the wound healing process, in response to mechanical strain via the NFkB pathway. TRPC3 is highly expressed in human hypertrophic scar tissue and mechanical stimuli are known to upregulate TRPC3 expression in human skin fibroblasts in vitro. TRPC3 overexpressing fibroblasts subjected to repetitive stretching forces showed robust expression levels of fibronectin. Furthermore, mechanical stretching of TRPC3 overexpressing fibroblasts induced the activation of nuclear factor-kappa B (NFκB), a regulator fibronectin expression, which was able to be attenuated by pharmacologic blockade of either TRPC3 or NFκB. Finally, transplantation of TRPC3 overexpressing fibroblasts into mice promoted wound contraction and increased fibronectin levels in vivo. These observations demonstrate that mechanical stretching drives fibronectin expression via the TRPC3-NFkB axis, leading to intractable wound contracture. This model explains how mechanical strain on cutaneous wounds might contribute to pathologic scarring.

End-to-side "loop" graft for total facial nerve reconstruction: Over 10 years experience.

BACKGROUND: Multiple-branch reconstruction is required in order to attain facial reanimation for extensive facial nerve defects. We previously reported that end-to-side nerve grafting, with the use of a single nerve graft for defect reconstruction, was easy to perform. We have also demonstrated the efficacy of end-to-side nerve suture of the recipient nerve to the donor graft nerve, in experimental rat models and clinical cases. The regenerating axons, which extended into the nerve graft, were "distributed" to multiple recipient nerves via end-to-side nerve-suture sites. METHODS: Thirty-two patients who underwent facial nerve reconstruction (five to 10 branches) had a single sural nerve graft coapted to the proximal stump of the facial nerve in an end-to-end manner, followed by end-to-side nerve suture of the recipient nerve stumps to the side of the nerve graft. In 19 patients who were expected to undergo postoperative radiotherapy and/or chemotherapy, the distal end of the graft was connected to the side of the hypoglossal nerve for "axonal supercharging," to enhance the recovery of the facial muscles. RESULTS: Initial facial movements were noted at 5-12 months postoperatively, and good recovery (House-Brackmann grade III/IV) was observed during long-term follow-up in most patients. CONCLUSION: End-to-side nerve suture of the recipient nerve stumps to the nerve graft requires less graft nerve material and less technical mastery to reconstruct multiple branches of the facial nerve. We also described the concept of "axonal supercharging," namely the connection of double-donor neural sources to the graft, and "axonal distribution," namely the reinnervation of multiple recipient nerve stumps connected to the graft in an end-to-side manner. This combination of axonal supercharging and distribution can be a useful option in facial nerve reconstruction.

The dawn of computer-assisted robotic osteotomy with ytterbium-doped fiber laser.

Currently, laser radiation is used routinely in medical applications. For infrared lasers, bone ablation and the healing process have been reported, but no laser systems are established and applied in clinical bone surgery. Furthermore, industrial laser applications utilize computer and robot assistance; medical laser radiations are still mostly conducted manually nowadays. The purpose of this study was to compare the histological appearance of bone ablation and healing response in rabbit radial bone osteotomy created by surgical saw and ytterbium-doped fiber laser controlled by a computer with use of nitrogen surface cooling spray. An Ytterbium (Yb)-doped fiber laser at a wavelength of 1,070 nm was guided by a computer-aided robotic system, with a spot size of 100 µm at a distance of approximately 80 mm from the surface. The output power of the laser was 60 W at the scanning speed of 20 mm/s scan using continuous wave system with nitrogen spray level 0.5 MPa (energy density, 3.8 × 10(4) W/cm(2)). Rabbits radial bone osteotomy was performed by an Yb-doped fiber laser and a surgical saw. Additionally, histological analyses of the osteotomy site were performed on day 0 and day 21. Yb-doped fiber laser osteotomy revealed a remarkable cutting efficiency. There were little signs of tissue damage to the muscle. Lased specimens have shown no delayed healing compared with the saw osteotomies. Computer-assisted robotic osteotomy with Yb-doped fiber laser was able to perform. In rabbit model, laser-induced osteotomy defects, compared to those by surgical saw, exhibited no delayed healing response.

Immediate reconstruction using free medial circumflex femoral artery perforator flaps after breast-conserving surgery.

Recent advances in perforator flap surgical techniques have allowed for safe and reliable autologous tissue transfer with minimal donor-site morbidity. Between April 2012 and January 2013, we performed immediate breast reconstruction using free medial circumflex femoral artery perforator (MCFAP) flaps in 15 patients after breast-conserving surgery. The flaps were harvested from patients in the lithotomy position, while a second surgical team simultaneously conducted tumour resection. Of the 15 procedures performed, three flaps were dissected as true perforator flaps, while 12 flaps were dissected as muscle-sparing perforator flaps. The mean flap weight was 138.5 g (range, 77-230 g) and the mean pedicle length was 5.7 cm (range, 3.0-9.0 cm). Recipient vessels for anastomosis were serratus branches in 10 patients, internal mammary vessels in three patients and thoracodorsal vessels in two patients. The mean duration of surgery was 6.74 h (range, 5.65-9.45 h). There were no major complications requiring surgical intervention. Researchers observed partial flap necrosis, which manifested as small firm lesions in two patients, as well as local wound infection and dehiscence in one patient, which resolved spontaneously. There were no instances of donor-site seroma formation or lymphoedema in any of the patients. An objective assessment of postoperative photographs showed that cosmetic results were mostly satisfactory. Donor-site scars along the medial groin crease were inconspicuous and readily concealed by clothing. Given its reliable vascularity and minimal donor-site morbidity, the free MCFAP flap can be a good alternative for partial breast reconstruction after breast-conserving surgery.

Influence of continuous or intermittent negative pressure on bacterial proliferation potency in vitro.

Negative pressure wound therapy is helpful and effective in the treatment of intractable skin ulcers and defects, not only acute wounds. However, application of negative pressure wound therapy for an infected wound is still controversial. The authors developed an in-vitro model of negative pressure wound therapy and investigated the influence of various types of negative pressure environment on the proliferation potency of non-pathogenic Escherichia coli. E. coli in Luria-Bertani liquid media was cultured at 37°C under different environments, which were normal atmosphere in group 1, continuous negative pressure of 75 mmHg in group 2, intermittent negative pressure of 75 mmHg with cycle time of 1 minute aspiration and 1 minute abeyance in group 3, with the one of 3 minutes aspiration and 3 minutes abeyance in group 4. The relative amounts of E. coli in each group were investigated at different times. The proliferation potency of E. coli was higher under negative pressure than under normal atmosphere; higher under intermittent negative pressure than under continuous negative pressure; and higher under intermittent negative pressure with a short cycle than with a long cycle. It is important to consider the possibility that the intermittent and continuous mode of negative pressure wound therapy may promote proliferation of bacteria in an infected wound with no blood flow like necrotic tissue.