Efficacy of hyperbaric oxygen after microtia reconstruction using costal cartilage: A retrospective case-control study.

Introduction: Microtia reconstruction with autologous costal cartilage framework grafting is challenging because the three-dimensional structure of the ear is highly complex, and meeting the high aesthetic demands of patients can be difficult. If the skin flap overlying the framework is thinned to achieve a smooth and accentuated outline, a poor blood supply in the thin skin flap may lead to skin necrosis, exposure of the framework, and poor surgical results. Hyperbaric oxygen (HBO2) therapy can promote the healing of complex wounds and flaps. This study sought to determine the effectiveness of HBO2 therapy for the prevention of postoperative complications after framework grafting in microtia reconstruction. Methods: We retrospectively evaluated postoperative complications and compared outcomes in pediatric patients who underwent costal cartilage grafting for microtia reconstruction at our institution between 2011 and 2015, according to whether or not they received postoperative HBO2 therapy. HBO2 therapy was applied once daily for a total of 10 sessions starting on the first postoperative day. Results: During the study period, eight patients received HBO2 therapy after costal cartilage grafting, and 12 did not. There was no significant difference in the incidence of postoperative ulcers. However, the incidence of framework exposure was lower, and the healing time was shorter in patients who received HBO2 therapy than in those who did not. Discussion: HBO2 therapy can be used safely in pediatric patients to reduce postoperative complications and improve the aesthetic outcome of microtia reconstruction. After costal cartilage grafting, HBO2 therapy should be considered as adjuvant therapy.

Effect of Pre-Surgical Orthopedic Treatment on Hard and Soft Tissue Morphology in Infants with Cleft Lip and Palate.

The frequency of cleft lip and palate births in Japan is approximately 0.146%. The study aimed to compare the effects of NAM on restoring nasal morphology and improving extraoral nasal morphology in children with cleft lip and palate in the first stage of treatment using 3D imaging and oral model analysis. The subjects were five infants (37.6 ± 14.4 days old) with unilateral cleft lip and palate. The images taken with the 3D analyzer and oral model used for constructing the NAM at the first examination (baseline) and at the completion of the pre-surgical orthodontic treatment (157.8 ± 37.8 days old) were analyzed. The cleft distance was measured at the upper, middle, and lower points on the 3D images. On the model, the cleft jaw width at the maximum protrusion of the healthy and affected sides of the alveolar bone was measured. After the pre-surgical orthopedic treatment, the measured value on the model decreased significantly by a mean of 8.3 mm from baseline, and the cleft lip width narrowed by an average of 2.8 ± 2.2, 4.3 ± 2.3, and 3.0 ± 2.8 mm at the upper, middle, and lower points of the cleft, respectively. Pre-surgical orthopedic treatment using NAM can help narrow the width of the cleft jaw and lip. The sample size is stated at the study limit in the paper.

A Preliminary Study of Interdisciplinary Approach with a Single-Stage Surgery in Children with Cleft Lip and Palate.

A two-stage surgical procedure involving labioplasty and palatoplasty is a common surgical modality performed in children with cleft lip and palate. Additionally, an alveolar cleft bone graft is performed prior to the eruption of the canine teeth. These three surgeries impose the burden of general anesthesia separately for each procedure, and the formation of scar tissue from the procedure inhibits maxillary growth. We adopted a single-stage surgical procedure to overcome these drawbacks. To date, there have been no reports comparing the treatment outcomes of alveolar morphology and maxillary growth and development in children who underwent single-stage surgery with those who underwent two-stage surgery using plaster casts and cephalograms. Twenty children aged 5-7 years were equally divided into two groups based on whether they had undergone a two- or single-stage procedure. Cephalometric analysis and analysis of dentition models were conducted. The results showed that the single-stage surgery exhibited significant differences in the sella-nasion angle, point A to McNamara line, maxillary length, mandibular body length, and posterior arch width and length compared with the two-stage surgery. Therefore, it was suggested that the single-stage surgery had a favorable effect on maxillary growth compared with the two-stage surgery.

A Comparison of Outcomes After Palatoplasty in Patients With Non-Syndromic Pierre Robin Sequence Versus Patients With Non-Syndromic Isolated Cleft Palate.

The purpose of this retrospective study was to compare outcomes of cleft palate repair in patients with non-syndromic Pierre Robin sequence (NS-PRS) versus those with non-syndromic isolated cleft palate (NS-ICP). Pierre Robin sequence (PRS) was defined as a diagnosis of the triad of microretrognathia, glossoptosis, and cleft palate, and the severity of PRS was assessed based on the presence of respiratory and feeding problems. All patients underwent palatoplasty between January 2000 and December 2011. The authors examined age at palatoplasty, type of cleft palate, fistula rate, velopharyngeal (VP) function, nasal emission, hypernasality, and need for secondary speech surgery, in addition to PRS severity in the NS-PRS patients. A total of 15 NS-PRS patients and 40 NS-ICP patients were reviewed. The incidence of VP dysfunction, nasal emission, hypernasality, and secondary speech surgery was not significantly different between the NS-PRS patients and NS-ICP patients. Age at palatoplasty was significantly different between the 2 groups (P = 0.012) but type of CP was not (P = 1.00). Only 2 NS-PRS patients were classified as category III (severe), and all of the NS-PRS patients who had VP insufficiency were classified as PRS severity category I (not severe). The findings of this study indicate that NS-PRS patients may not have worse outcomes than NS-ICP patients.

Oculo-Auriculo-Fronto-Nasal Syndrome With Duane Retraction Syndrome and Dysplastic Bony Structure in the Midline of Nose.

Oculo-auriculo-fronto-nasal syndrome (OAFNS) is a rare anomaly characterized by features overlapping those of frontonasal dysplasia (FND) and the oculo-auriculo-vertebral spectrum (OAVS). The FND features malformation of frontonasal process-derived structures, characterized by anomalies in the central portion of the face. The OAVS is characterized by developmental anomalies of the first and second pharyngeal arches. The OAFNS is a condition with clinical features of both FND and OAVS.Here, the authors present the case of a male with OAFNS who not only exhibited typical OAFNS symptoms but also a dysplastic bony structure that bridged the anterior nasal spine and inferior nasal bones, and unilateral type 3 Duane retraction syndrome (absence of right-eye abduction). Abnormal nasal bones are characteristic of OAFNS; such abnormalities are absent from FND and OAVS. The authors reduced the dysplastic nasal bony structure via open external rhinoplasty, followed by lateral nasal osteotomy when he was 16 years of age. The nasal dorsum appeared natural after surgery and he was satisfied with the result.

Changes in high endothelial venules in lymph nodes after vascularized and nonvascularized lymph node transfer in a murine autograft model.

BACKGROUND AND OBJECTIVES: Vascularized lymph node transfer (LNT) is gaining popularity in the treatment of lymphedema. However, it is unclear whether the vascularization of transferred lymph nodes (LNs) contributes to functional improvement. High endothelial venules (HEVs) are specialized vessels that allow lymphocytes to enter LNs. In this study, we compared the numbers of HEVs and lymphocytes in LNs after vascularized and nonvascularized LNT. METHODS: Fifty mice were divided into three groups (group 1, pedicled vascularized LNT; group 2, pedicled nonvascularized LNT; group 3, free nonvascularized LNT). Afferent lymphatic reconnection was confirmed by patent blue staining. The transferred LNs were harvested 4 weeks after surgery. HEVs, B-cells, and T-cells were subjected to immunohistochemical staining and quantified. RESULTS: Afferent lymphatic reconnection was observed in 13 of 20 transferred LNs in group 1, 11 of 15 in group 2, and 7 of 15 in group 3. The ratio of dilated/total HEVs in transferred LNs with afferent lymphatic reconnection was significantly higher in group 1 than in groups 2 and 3. No significant differences in numbers of B-cells and T-cells were found in the transferred LNs. CONCLUSIONS: We found that more functional HEVs were preserved in cases with successful afferent lymphatic reconnection after vascularized LNT than after nonvascularized LNT.

Comparison of Nasal Symmetry Between Presurgical Nasal Stenting and Postsurgical Nasal Retainer Placement in Unilateral Clefts.

The timing of cleft lip nose surgery remains controversial. The less invasive the procedure at the time of primary cleft lip repair, the less the growth and development of the nose is affected. Therefore, the nasal-stenting component of presurgical nasoalveolar molding has increasingly been used. However, not all cleft centers use such treatment. Conventional postsurgical placement of silicone nasal retainers remains popular. No report has yet compared presurgical nasal stenting (preNS) and postsurgical nasal retainer placement (postNR). In this study, postoperative nasal form outcomes after primary lip repair using preNS or postNR in patients with complete unilateral cleft lips, alveoli, and palates were compared. Patients in whom preNS alone was used for 6 months (group I) were compared with those receiving postNR (no preNS) for 6 months after primary nasal cartilage dissection (group II) and controls with no appliance (group III). Nasal anthropometric distances and angular relationships were measured photographically to assess nasal symmetry at 4 years of age in all groups. Compared to group III, groups I and II exhibited significantly greater nostril heights (P = 0.0075, P = 0.0015 respectively) and columellar deviation angles (P = 0.0020, P = 0.0221). Groups I and II did not differ significantly. No significant between-treatment difference in terms of nasal symmetry between preNS and postNR was observed. However, both treatments afforded significantly better results than no treatment. Since older infants tend to resist the placement of nasal devices, preNS is more feasible in this age group.

Feasibility of pedicled vascularized inguinal lymph node transfer in a mouse model: A preliminary study.

PURPOSE: Vascularized lymph node transfer is becoming more common in the treatment of lymphedema, but suitable small animal models for research are lacking. Here, we evaluated the feasibility of pedicled vascularized inguinal lymph node transfer in mice. METHODS: Twenty-five mice were used in the study. An inguinal lymph node-bearing flap with a vascular pedicle containing the superficial caudal epigastric vessels was transferred into the ipsilateral popliteal fossa after excision of the popliteal lymph node. Indocyanine green (ICG) angiography was used to confirm vascularity of the flap. ICG lymphography was performed to evaluate lymphatic flow at 3 and 4 weeks postoperatively. Patent blue dye was injected into the ipsilateral hind paw to observe staining of the transferred lymph node at 4 weeks postoperatively. All transferred lymph nodes were then harvested and histologically evaluated by hematoxylin and eosin staining. RESULTS: In 16 of the 25 mice, ICG lymphography showed reconnection between the transferred lymph node and the afferent lymphatic vessels, as confirmed by patent blue staining. Histologically, these transferred lymph nodes with afferent lymphatic reconnection significantly regressed in size (0.37 ± 0.24 mm2 ) and showed clear follicle formation, whereas those without afferent lymphatic reconnection showed less size regression (1.31 ± 1.17 mm2 ); the cell population was too dense to allow identification of follicles. CONCLUSIONS: We established a mouse model of vascularized lymph node transfer with predictable afferent lymphatic reconnection. Both the vascularization and reconnection might be necessary for functional regeneration of the transferred lymph node.

Immune-mediated antitumor effect of a transplanted lymph node.

Lymph node (LN) transplantation is a recognized method for reconstruction of the lymphatic system and is used in the clinical setting to treat lymphedema. However, it is unclear whether transplanted LNs contribute to immune surveillance. In our study, we investigated whether a single transplanted non-vascularized LN, defined as a tumor-draining transplanted lymph node (TDTLN), could exert an immune-mediated antitumor effect. LN and lung metastases and primary tumor enlargement were evaluated in mice that were inoculated with B16-F10-luc2 melanoma cells in a hind limb footpad without (group 1) and with (group 2) popliteal lymph node (PLN) resection and in mice that underwent LN transplantation after PLN resection (group 3). The function of a TDTLN (group 3) and a tumor-draining popliteal lymph node (TDPLN; group 1) was evaluated in the context of cancer. LN and lung metastases were significantly aggravated by PLN resection but were significantly decreased by LN transplantation. Immunohistochemistry showed that the TDTLNs retained T-cells and B-cells and fluorescence-activated cell sorting analysis confirmed expansion of lymphocytes in these nodes; however, the degree of expansion in TDTLNs was different from that in TDPLNs. Expression of cytokines associated with immunostimulation was confirmed in the TDTLNs as well as in the TDPLNs. One of the differences in the immune-mediated antitumor effect of the TDPLNs and TDTLNs was ascribed to a difference in the site of lymphocyte homing to peripheral LNs through high endothelial venules. Non-vascularized LN transplantation had an immune-mediated antitumor effect.

Conditioned Medium Obtained from Amnion-Derived Mesenchymal Stem Cell Culture Prevents Activation of Keloid Fibroblasts.

BACKGROUND: Mesenchymal stem cells are a valuable cell source in regenerative medicine, and conditioned medium obtained from mesenchymal stem cells reportedly inhibits inflammation. Keloids are characterized by abnormal fibrosis, caused by fibroblasts in response to inflammation. In this study, the authors evaluated whether conditioned medium obtained from amnion-derived mesenchymal stem cells suppressed activation of keloid fibroblasts. METHODS: Keloid (n = 7), mature (n = 5), and normal (n = 5) fibroblasts were harvested from patients. Fibroblasts were stimulated with transforming growth factor (TGF)-ß, and the effects of conditioned medium obtained from amnion-derived mesenchymal stem cells on cell proliferation, activation, and expression of extracellular matrix-related genes were analyzed. The effect of concentrating the conditioned medium by ultrafiltration on fibroblast activation was also analyzed. RESULTS: Conditioned medium obtained from amnion-derived mesenchymal stem cells significantly up-regulated proliferation of mature fibroblasts but tended to suppress that of keloid fibroblasts. Conditioned medium obtained from amnion-derived mesenchymal stem cells significantly suppressed the TGF-ß-induced up-regulation of α-smooth muscle actin in keloid and normal fibroblasts and collagen I in keloid fibroblasts, but not in mature fibroblasts. The conditioned medium obtained from amnion-derived mesenchymal stem cells concentrated by ultrafiltration and the filtrate significantly suppressed TGF-ß-induced α-smooth muscle actin expression. CONCLUSION: Conditioned medium obtained from amnion-derived mesenchymal stem cells prevents proliferation and activation of keloid fibroblasts and is a promising keloid treatment for administration as a topical agent. CLINICAL QUESTION/LEVEL OF EVIDENCE: Therapeutic, V.

Lymphatic Reconnection and Restoration of Lymphatic Flow by Nonvascularized Lymph Node Transplantation: Real-Time Fluorescence Imaging Using Indocyanine Green and Fluorescein Isothiocyanate-Dextran.

BACKGROUND: Lymph node transplantation is being increasingly recognized as a method of reconstruction of the lymphatic system for the treatment of lymphedema. However, the mechanisms regulating the connections between the lymphatic vessels and the lymph nodes remain poorly understood. The objective of this study was to examine whether removal of a popliteal lymph node (PLN) could result in rerouting of lymph flow and whether a single transplanted nonvascularized lymph node could reconnect with a lymphatic vessel and restore lymph flow. METHODS AND RESULTS: Thirty-six mice were allocated to undergo resection of a PLN alone (group 1) or a transplanted lymph node after resection of a PLN (group 2). Changes in lymph flow were observed using indocyanine green dye. The ability of the transplanted lymph node to reconnect with the lymphatic vessels was examined by fluorescein isothiocyanate (FITC)-dextran and immunohistochemical staining. In group 1, the flow of lymph was redirected to an inguinal lymph node (ILN) in 8 of 18 mice and continued to drain to the PLN in 10 mice. In group 2, the lymph continued to drain normally after removal of the PLN, and was also directed to an ILN in two mice. FITC-dextran demonstrated continuity of the transplanted PLN and the lymphatic vessels. Immunohistochemical staining showed that T cell and B cell populations in the transplanted lymph node were preserved. CONCLUSION: Lymphatic flow was rerouted after lymph node resection. A transplanted lymph node can be made viable with normal lymph flow by reconnecting the transplanted lymph node to a lymphatic vessel.

Transarterial Embolization and Transmucosal Sclerotherapy That Led to Successful Deliveries in a Patient With Symptomatic Arteriovenous Malformation of the Tongue.

Patients with arteriovenous malformations (AVMs) are at risk of significant hemorrhage and AVMs are especially difficult to manage in those desiring future pregnancy. Few patients with successful deliveries have been previously reported.The authors report an unusual case of AVM of the tongue in a pregnant woman who presented with massive pulsatile bleeding from a ruptured artery in the tongue in late gestation, this was thought to be caused by the changes in hormonal balance and the increase in cardiac output. The bleeding was controlled with transarterial embolization and transmucosal absolute ethanol sclerotherapy. Furthermore, her second and third deliveries were successfully managed.The authors managed symptomatic tongue AVM by combining transarterial embolization and transmucosal sclerotherapy, which was followed by successful deliveries. This patient supports the utility of transmucosal absolute ethanol sclerotherapy for tongue AVM and multidisciplinary medical care for a successful delivery.

Dominant lymph drainage patterns in the occipital and parietal regions: evaluation of lymph nodes in patients with skin cancer of the head.

BACKGROUND: The purpose of this study was to evaluate the superficial lymph drainage patterns of primary skin cancers of the head arising from the occipital or parietal region. METHODS: The dominant patterns of lymph drainage were retrospectively reviewed in eight patients aged 36-85 years with skin cancers in the occipital or parietal region in whom sentinel lymph node biopsy or lymph node dissection had been performed at Hokkaido University Hospital between January 1981 and December 2015. RESULTS: Lymph drainage was mainly to the occipital (6/8, 75%), level II (5/8, 63%), and level V lymph nodes (5/8, 63%). Of the six patients with drainage to the occipital lymph nodes, four (67%) also had drainage to level V nodes. CONCLUSION: The dominant lymph drainage pattern in patients with skin cancer arising from the occipital or parietal region was to the occipital, level II, and level V lymph nodes. Further, lymph tended to drain directly from the occipital region to the level V lymph nodes.

Full-Thickness Entire Nasal Alar Reconstruction Using a Forehead Flap in Asians: No Cartilaginous Infrastructural Lining Is Necessary.

Full-thickness defects of the entire nasal ala, including the rim, can be challenging to reconstruct. A forehead flap may provide a more imperceptible and natural-appearing reconstructed nasal ala. Previously, many authors have insisted adding cartilaginous infrastructural support for an entire, full-thickness defect to keep the postoperative alar structure symmetrical. They finally use a forehead flap after thinning of the distal covering portion subcutaneously, possibly for a Caucasian-type nasal ala. However, Asian skin has a thicker and more compact dermis than that of Caucasian skin, and the Asian ala is rounder and thicker. There may be another approach for an Asian-type nasal ala. The authors propose the possibility of nasal alar reconstruction for an entire, full-thickness defect in Asians using a forehead flap without structural support. Six patients with entire full-thickness nasal alar defects treated with full-thickness forehead flaps above the periosteum without structural support were reviewed. Five patients demonstrated esthetically good to excellent outcomes in color, texture, and symmetry. Their nasal linings were reconstructed using mucoperiosteal flaps or mucosal grafts. One patient treated with a nasal lining using a local flap showed a fair result esthetically. Asians forehead above the periosteum has adequate thickness and supportability to reconstruct the entire full-thickness nasal ala in Asians. No cartilage support is necessary.

Review and proposal of regional surgical management for melanoma: revisiting of integumentectomy and incontinuity dissection in treatment of skin melanoma.

BACKGROUND: Past studies showed that integumentectomy and incontinuity could be effective procedures in the surgical management of melanoma patients. The present study reports on the historical background of these procedures. In addition, we analyze the ICG assisted integumentectomy and incontinuity techniques and algorithms that we had created when performing this procedure. METHOD: In accordance with our algorithm, we performed ICG assisted integumentectomy/incontinuity procedures on 17 patients with stage III melanomas between 2008 and 2016. We also investigated the locoregional recurrence rate in a control group comprising 60 patients at stage III without using the algorithm. RESULTS: The former group exhibited a tendency of locoregional recurrence rate suppression. Melanoma cells in the dissected intervening tissue were microscopically identified in 2 out of 17 cases. CONCLUSIONS: Our ICG assisted integumentectomy or incontinuity procedures could be effective in controlling locoregional recurrence rates in melanoma cases. Moreover, our method can be generally applied because the dissection is only performed within the lymphatic pathway region identified using indocyanine green.

Establishment of an Acquired Lymphedema Model in the Mouse Hindlimb: Technical Refinement and Molecular Characteristics.

BACKGROUND: The pathophysiology of secondary lymphedema remains poorly understood. This study aimed to establish a consistent mouse hindlimb lymphedema model for further investigation of the mechanism and treatment of lymphedema. METHODS: The authors developed a novel postsurgical lymphedema model in the mouse hindlimb by modifying previously described methods. Lymphedema in the hindlimb was created by removing both the inguinal and popliteal lymph nodes together with the surrounding fat pads, followed by silicone splint placement in the inguinal region. Using this modified mouse model, the authors analyzed lymphatic function, histologic changes, and the expression of lymphangiogenic factors including vascular endothelial growth factor C at various time points. RESULTS: The splinted lymphedema model showed a significant increase of edema formation in the hindlimb compared with the sham surgery control animals. Indocyanine green lymphography revealed lymphatic drainage impairment shown by dermal backflow and rerouting of lymph flow in the lymphedema model. Histopathologic and immunohistochemical examinations showed a significant increase of skin thickness and abnormally dilated lymphatics in the lymphedema model. The expression of lymphangiogenic factors in lymphedematous tissues of the splinted lymphedema model was significantly increased compared with controls, depending on the degree of lymphedema. CONCLUSIONS: This splinted lymphedema model closely simulates the volume response, histopathology, and lymphography characteristics of human acquired lymphedema. Given these similarities to human lymphedema, this refinement of a mouse hindlimb model of acquired lymphedema represents a promising platform for the study of lymphatic vascular insufficiency and for the evaluation of new therapeutic modalities.

Evaluation of the maxillofacial morphological characteristics of Apert syndrome infants.

Apert syndrome is a rare craniosynostosis syndrome characterized by irregular craniosynostosis, midface hypoplasia, and syndactyly of the hands and feet. Previous studies analyzed individuals with Apert syndrome and reported some facial and intraoral features caused by severe maxillary hypoplasia. However, these studies were performed by analyzing both individuals who had and those had not received a palate repair surgery, which had a high impact on the maxillary growth and occlusion. To highlight the intrinsic facial and intraoral features of Apert syndrome, five Japanese individuals with Apert syndrome from 5 years and 2 months to 9 years and 10 months without cleft palate were analyzed in this study. A concave profile and a skeletal Class III jaw-base relationship caused by severe maxillary hypoplasia were seen in all patients. The patients exhibited anterior and posterior crossbites possibly due to a small dental arch of Maxilla.

Exploration of more effective neurorrhaphy in facial nerve reconstruction: A comparison focusing on the difference of neural window size and condition of the neurorrhaphy site.

BACKGROUND AND AIM: Various techniques have been introduced for reconstruction of the facial nerve. An improved method of neurorrhaphy to achieve satisfactory mimetic muscle function is required. We made and compared three different neurorrhaphy models to elucidate the effect of neural window size and condition of the neurorrhaphy site on axonal regeneration. METHODS: Rats were divided into four groups: group A, untreated incomplete palsy; group B, treatment by end-to-side neurorrhaphy through a small perineural window; group C, treatment by side-to-side neurorrhaphy through a large perineural window; and group D, treatment by side-to-side neurorrhaphy through a small perineural window. After surgery, mimetic muscle movement was evaluated. Retrograde-labeled neurons through the facial nuclei were counted, and mimetic muscle specimens were examined. The axon number was counted in nerve specimens. RESULTS: The facial palsy scores of groups B and C were significantly greater than those of groups A and D. With regard to the number of neurons at the facial nuclei, groups B and C had more neurons than groups A and D. Group D had significantly more neurons than group A. With respect to the number of axons, groups B, C, and D had significantly greater numbers than group A, but there were no significant differences between the reconstructed groups. CONCLUSIONS: Window size and condition of the neurorrhaphy site, which affected mainly the number of axons, influenced axonal regeneration in nerve reconstruction. This result indicates the possibility of obtaining a better result for facial nerve or other peripheral nerve reconstruction with a tidbit of operative artifice.

Reconstruction of Large Cheek Defect With/Without Sideburn Using Malar-Posterior Auricular-Cervico Flap.

The cheek region is the most common site for malignant tumor occurrence and the treatment of malignant skin tumor requires extensive local excision. Many previous reports have covered methods of reconstruction using local flaps for skin defects in the cheek region.In this article, we describe our experience with a surgical reconstruction using a new flap method for 8 patients with missing tissue in the cheek region. This flap is based on the concept of separately designing the flap with the 3 areas comprising the malar, posterior auricular, and cervical regions. We named the flap containing these 3 regions the malar-posterior auricular-cervico flap. Esthetically satisfactory outcomes were achieved in all cases.In conclusion, we recommend our malar-posterior auricular-cervico flap to reconstruct the tissue defects of approximately 20 to 40 cm after tumor excision in the cheek region. If preauricular skin is included in the design of this flap, the sideburn can be reconstructed using a part of the nape region with hair.

Neuregulin-1 released by biodegradable gelatin hydrogels can accelerate facial nerve regeneration and functional recovery of traumatic facial nerve palsy.

BACKGROUND AND AIM: Neuregulin-1 is an essential axoglial signal required for peripheral nerve development, and evidence that neuregulin-1 is also required for effective nerve repair is growing. In this study, the effects of neuregulin-1-impregnated gelatin hydrogels on nerve regeneration and functional recovery after anastomosis of the facial nerve were investigated in a rat model of traumatic facial nerve paralysis. MATERIALS AND METHODS: Twenty-four adult male rats underwent complete resection of the facial nerve trunk, followed by end-to-end anastomosis with epineural sutures. The animals were then randomly allocated to one of three treatment groups (eight rats/group): no additional intervention (Group I), single-shot injection of neuregulin-1 into the epineurium of the facial nerve at the suture sites (Group II), or implantation of a hydrogel impregnated with neuregulin-1 at the injury site (Group III). After surgery, mimetic muscle movements were evaluated weekly. Eight weeks after surgery, the mimetic muscles were injected with a neural tracer (1,10-dioctadecyl-3,3,30,30-tetramethylindocarbocyanin perchlorate, DiI). Retrograde-labeled neurons were counted in the facial nuclei, and facial nerve specimens were stained with toluidine blue for histological examination of axon density. RESULTS: Group III exhibited significantly faster recovery of mimetic muscle function, a higher density of large-diameter axons (>5 µm) in the facial nerve, and greater numbers of retrogradely labeled neurons in the ipsilateral facial nucleus compared with Groups I and II. CONCLUSIONS: Continuous release of neuregulin-1 from impregnated gelatin hydrogels can accelerate facial nerve regeneration.