Association of cranial base suture/synchondrosis fusion with severity of increased intracranial pressure in Crouzon syndrome.

This study investigated how the fusion states of the cranial base is related to the degree of increased intracranial pressure (ICP) in patients with Crouzon syndrome. This retrospective cohort study enrolled patients who were diagnosed with Crouzon syndrome between May 2007 and April 2022. We categorized the patients into three groups: A, B, and C, according to the severity of increased ICP and the number of cranial vault remodeling procedures for corrective operation. The preoperative fusion states of the cranial base sutures/synchondroses were examined using facial bone computed tomography and compared between groups. Overall, 22 patients were included in Groups A, B, and C, including 8, 7, and 7 patients, respectively. The preoperative average grades of the total cranial base suture/synchondrosis fusion appeared to significantly increase with severity, except for the frontoethmoidal suture, which showed the opposite tendency. In the subgroup analysis, frontosphenoidal, sphenoparietal, sphenosquamosal, parietomastoid, and occipitomastoid suture and petro-occipital synchondrosis were associated with earlier fusion in the more severe group. Premature closure of the cranial base sutures/synchodroses seems to be associated with increased ICP severity in patients with Crouzon syndrome. Precise evaluation of minor sutures/synchondroses at the first visit might help build subsequent operative plans and predict disease prognosis.

Evaluation of Long-Term Outcomes of Transverse Facial Cleft Repair.

OBJECTIVE: To evaluate the long-term outcomes of linear commissuroplasty and linear skin closure with a focus on commissural migration. DESIGN: Retrospective study. PATIENTS: Individuals who underwent transverse facial cleft repair at a single institution between 2004 and 2021. INTERVENTIONS: The disrupted orbicularis oris muscle was reoriented and sutured. A simple linear commissuroplasty technique was used, and the cheek skin was closed linearly without Z-plasty. MAIN OUTCOME MEASURES: The distances from Cupid's bow peak to the oral commissure were measured bilaterally, and the difference between the normal and cleft sides was obtained. Finally, its proportional value as a percentage of the total lip length was calculated from short- and long-term follow-up photographs. Cheek scarring and its effects on melolabial fold breakage were evaluated. RESULTS: Of the 18 patients who underwent transverse facial cleft repair, 12 were included in this study. The mean follow-up period based on medical photographs was 1773.5 days. The average proportional difference was 4.6%, demonstrating no observable commissural migration. There were no consistent trends in the direction of migration, either on the cleft or normal side. In patients with a transverse cleft crossing the melolabial fold, the folds appeared broken before and after the cleft repair surgery. CONCLUSIONS: No significant long-term commissural migration was observed after transverse facial cleft repair with simple linear commissuroplasty and linear skin closure. Deliberate positioning of the new oral commissure, proper myoplasty, and meticulous skin closure with minimal scar burden can be considered key procedures for successful transverse cleft repair.

Postoperative Nausea and Vomiting Prediction: Machine Learning Insights from a Comprehensive Analysis of Perioperative Data.

Postoperative nausea and vomiting (PONV) are common complications after surgery. This study aimed to present the utilization of machine learning for predicting PONV and provide insights based on a large amount of data. This retrospective study included data on perioperative features of patients, such as patient characteristics and perioperative factors, from two hospitals. Logistic regression algorithms, random forest, light-gradient boosting machines, and multilayer perceptrons were used as machine learning algorithms to develop the models. The dataset of this study included 106,860 adult patients, with an overall incidence rate of 14.4% for PONV. The area under the receiver operating characteristic curve (AUROC) of the models was 0.60-0.67. In the prediction models that included only the known risk and mitigating factors of PONV, the AUROC of the models was 0.54-0.69. Some features were found to be associated with patient-controlled analgesia, with opioids being the most important feature in almost all models. In conclusion, machine learning provides valuable insights into PONV prediction, the selection of significant features for prediction, and feature engineering.

Harnessing Machine Learning for Prediction of Postoperative Pulmonary Complications: Retrospective Cohort Design.

Postoperative pulmonary complications (PPCs) are significant causes of postoperative morbidity and mortality. This study presents the utilization of machine learning for predicting PPCs and aims to identify the important features of the prediction models. This study used a retrospective cohort design and collected data from two hospitals. The dataset included perioperative variables such as patient characteristics, preexisting diseases, and intraoperative factors. Various algorithms, including logistic regression, random forest, light-gradient boosting machines, extreme-gradient boosting machines, and multilayer perceptrons, have been employed for model development and evaluation. This study enrolled 111,212 adult patients, with an overall incidence rate of 8.6% for developing PPCs. The area under the receiver-operating characteristic curve (AUROC) of the models was 0.699-0.767, and the f1 score was 0.446-0.526. In the prediction models, except for multilayer perceptron, the 10 most important features were obtained. In feature-reduced models, including 10 important features, the AUROC was 0.627-0.749, and the f1 score was 0.365-0.485. The number of packed red cells, urine, and rocuronium doses were similar in the three models. In conclusion, machine learning provides valuable insights into PPC prediction, significant features for prediction, and the feasibility of models that reduce the number of features.

Single-stage Repair of Bilateral Cleft Lip and Bilateral Transverse Facial Cleft in Goldenhar Syndrome: A Case Report.

Goldenhar syndrome (GS) is a rare congenital disorder characterized by multiple facial anomalies. This case report describes a GS presenting with bilateral cleft lip and palate and bilateral transverse facial cleft. We performed a single-stage surgery to repair the bilateral cleft lip and bilateral transverse facial cleft when the patient was 4-months-old. Bilateral cleft lip repair using the Mulliken method was performed first, and then the bilateral transverse facial cleft was corrected. Orbicularis oris muscle repair was done at each clefts. Anatomical approximation technique was used and the final oral commissure was determined considering symmetry. Satisfactory outcomes were achieved without complications.

Usefulness of resorbable plate in auricular elevation in two-stage microtia reconstruction.

BACKGROUND: Achieving a well-reconstructed retroauricular sulcus with satisfactory projection and a sufficiently deep retroauricular sulcus is important and at the same time challenging. The selection of the support material is crucial to obtain a sustainable, deep sulcus. The costal cartilage is the conventional material of choice. However, risk of slippage of inserted cartilage and donor site morbidity exists. Resorbable plates are durable, easy to secure and can be easily modified into desired shape. The current study aimed to demonstrate the effectiveness of using a resorbable plate for auricular elevation. METHODS: Retrospective review of patients who received auricular elevation with resorbable plates from December 2020 to October 2022 was performed. Patients demographics, number of inserted plates and screws, postoperative complication were analyzed. RESULTS: Of 65 patients with microtia who underwent auricular reconstruction, resorbable plates were applied to 12 patients. Mean follow up period was 198 (range, 86-360) days. Auricular elevation was performed with one plate at cavum conchae and remnant rib cartilage at the helix in 10 patients (87)%. Two patients had resorbable plate as support material at the both sites. Regarding postoperative complications, there were no hematoma, seroma, plate exposure or plate fracture. Two patients suffered wound problems. One patient recovered only with conservative management. The other healed completely after debridement and intravenous antibiotics administration without undesired change of shape of ear. CONCLUSIONS: We suggest using resorbable plates as an ideal support material, as it can provide firm support to achieve appropriate depth of sulcus without excessive bulk.

"Strategic Application of Anatomical Subunit Approximation Technique for Correction of Complete Unilateral Cleft lip".

OBJECTIVE: To discuss advantages, disadvantages and strategical application of anatomical subunit approximation technique in complete unilateral cleft lip repair. DESIGN: Analysis of consecutive 28 cases. SETTING: A single surgeon experience at a university hospital. PATIENTS: Among 77 patients who underwent cleft lip repair between May 5, 2019 and June 30, 2021, 28 patients with complete unilateral cleft lip who received cheiloplasty by author's technique. MAIN OUTCOME MEASURES: Surgical outcomes were assessed by frontal view medical photographs obtained postoperatively at follow-up visits. RESULTS: The average length difference between cleft and noncleft sides was <10% for transverse lip length and philtral height. Nostril sill height demonstrated about twenty percent of difference with much variable results. Although the one sample t-test revealed that differences exist between the cleft and noncleft side, they were within an acceptable range. CONCLUSIONS: Understanding the strengths and limitations of anatomical subunit approximation technique enabled strategic application in complete unilateral cleft lip repair. Satisfactory outcomes were achieved not only regarding the scar placement but also regarding the symmetry of the lips and augmentation of nasal sill.

Effect of the preoperative physical status on postoperative nausea and vomiting risk: a matched cohort study.

BACKGROUND: The American Society of Anesthesiologists Physical Status Classification System is commonly used for preoperative assessment. Patient physical status before surgery can play an important role in postoperative nausea and vomiting. However, the relationship between the physical status classification and postoperative nausea and vomiting has not been well defined. METHODS: Adults aged ≥ 18 years who underwent procedures under anesthesia between 2015 and 2020 were included in the study. We analyzed the relationship of postoperative nausea and vomiting with physical status classification score using propensity score matching and Cox hazard regression. Differences in intraoperative use of vasopressor and inotropes and invasive monitoring were investigated according to the classification. RESULTS: A total of 163,500 patients were included in the study. After matching, classification 1 versus 2 included 43,400 patients; 1 versus ≤ 3, 13,287 patients; 2 versus ≤ 3, 23,530 patients (absolute standardized difference, 0-0.06). Patients with physical status classification ≤ 3 had a significantly lower postoperative nausea and vomiting risk than those with classification 1-2 (physical status classification 1 vs. ≤ 3, hazard ratio 0.76 [0.71-0.82], P < 0.001; 2 versus ≤ 3, hazard ratio 0.86 [0.82-0.91], P < 0.001). Intraoperative use of vasopressor or inotrope and invasive monitoring were noted more in the high physical status classification than the low physical status classification (absolute standardized difference [0.19-1.25]). CONCLUSION: There were differences in intraoperative invasive monitoring and use of vasopressor or inotrope among the classifications, and a score of 3 or higher reduced the risk of postoperative nausea and vomiting more than a score of 1-2.

Current concepts of neurofibromatosis type 1: pathophysiology and treatment.

Neurofibromatosis type 1 is the most common tumor predisposition syndrome inherited in an autosomal dominant (100% penetrance) fashion with a wide variety of expressivity. From the perspective of plastic surgery, the most significant clinical symptoms, including disfiguration, peripheral neurologic symptoms, and skeletal abnormalities, are caused by various tumors originating from the affected nerves. Surgical removal is the standard of care for these tumors. However, the outcome is frequently unsatisfactory, facilitating the search for additional therapeutic adjuvants. Current trials of molecularly targeted therapies are promising. Abbreviations: CALMs, café-au-lait macules; CNs, cutaneous neurofibromas; FDG, 18F-fluoro-deoxy-glucose; MAPK, mitogen-activated protein kinase; MPNSTs, malignant peripheral nerve sheath tumors; MRI, magnetic resonance imaging; NF1, neurofibromatosis type 1; NIH, National Institutes of Health; PET, positron emission tomography; PN, plexiform neurofibromas; TME, tumor microenvironment.

Eco-Friendly Dye-Sensitized Solar Cells Based on Water-Electrolytes and Chlorophyll.

Organic solvents used for electrolytes of dye-sensitized solar cells (DSSCs) are generally not only toxic and explosive but also prone to leakage due to volatility and low surface tension. The representative dyes of DSSCs are ruthenium-complex molecules, which are expensive and require a complicated synthesis process. In this paper, the eco-friendly DSSCs were presented based on water-based electrolytes and a commercially available organic dye. The effect of aging time after the device fabrication and the electrolyte composition on the photovoltaic performance of the eco-friendly DSSCs were investigated. Plasma treatment of TiO2 was adopted to improve the dye adsorption as well as the wettability of the water-based electrolytes on TiO2. It turned out that the plasma treatment was an effective way of improving the photovoltaic performance of the eco-friendly DSSCs by increasing the efficiency by 3.4 times. For more eco-friendly DSSCs, the organic-synthetic dye was replaced by chlorophyll extracted from spinach. With the plasma treatment, the efficiency of the eco-friendly DSSCs based on water-electrolytes and chlorophyll was comparable to those of the previously reported chlorophyll-based DSSCs with non-aqueous electrolytes.

Development and validation of a difficult laryngoscopy prediction model using machine learning of neck circumference and thyromental height.

BACKGROUND: Predicting difficult airway is challengeable in patients with limited airway evaluation. The aim of this study is to develop and validate a model that predicts difficult laryngoscopy by machine learning of neck circumference and thyromental height as predictors that can be used even for patients with limited airway evaluation. METHODS: Variables for prediction of difficulty laryngoscopy included age, sex, height, weight, body mass index, neck circumference, and thyromental distance. Difficult laryngoscopy was defined as Grade 3 and 4 by the Cormack-Lehane classification. The preanesthesia and anesthesia data of 1677 patients who had undergone general anesthesia at a single center were collected. The data set was randomly stratified into a training set (80%) and a test set (20%), with equal distribution of difficulty laryngoscopy. The training data sets were trained with five algorithms (logistic regression, multilayer perceptron, random forest, extreme gradient boosting, and light gradient boosting machine). The prediction models were validated through a test set. RESULTS: The model's performance using random forest was best (area under receiver operating characteristic curve = 0.79 [95% confidence interval: 0.72-0.86], area under precision-recall curve = 0.32 [95% confidence interval: 0.27-0.37]). CONCLUSIONS: Machine learning can predict difficult laryngoscopy through a combination of several predictors including neck circumference and thyromental height. The performance of the model can be improved with more data, a new variable and combination of models.

The Interchondral Joints of Thorax in Microtia Surgery: Classification and Fabrication Strategies.

BACKGROUND: The interchondral joint between the sixth and seventh costal cartilages, called synchondrosis, assists in harvesting and fabricating the microtia framework. However, its looseness often complicates the microtia surgery. We aimed to classify the interchondral joints based on looseness and identify predictors for each subtype. METHODS: Electronic chart and intraoperative photographs were reviewed for consecutive microtia patients who underwent costal cartilage graft for ear reconstruction from June 2001 to February 2020. The sixth and seventh costal interchondral joint was classified in the ascending order of looseness-direct cartilaginous fusion (class I), synovial joint (class II), and loose tissue (class III)-with a minor modification from the cadaveric study of Dr. Briscoe in 1925. χ2 Tests compared the incidence of each subtype in terms of patient variables including age, sex, chest laterality, and radiologic chest deformity. Multivariate logistic regression was used for identifying independent predictors for each subtype. RESULTS: Seven hundred thirty-three graft specimens were enrolled (mean age 12.1 years). Class I joint was seen in 137 (18.7%) grafts, class II in 544 (74.2%), and class III in 52 (7.1%). Female predilection was found for cartilaginous fusion (class I) (adjusted odds ratio, 1.691; P = 0.007). The incidence of loose joint (class III) was comparable, ranging from 4.6% to 12.5%, in terms of all the patient variables. CONCLUSIONS: Loose interchondral joints were not uncommon in microtia surgery. Patient variables were less likely to predict this anatomical variation, necessitating some knowledge of managing the framework instability. Female patients were more likely to enable easy fabrication with directly fused costal cartilages.

Benefits of the Multidisciplinary Approach After Curative Surgery for the Treatment of Scalp Angiosarcoma.

BACKGROUND: Patients with scalp angiosarcoma still present with a dismal prognosis, indicating the need for a multidisciplinary approach. The present study aimed to investigate the treatment outcomes of scalp angiosarcoma with a focus on the effect of radiotherapy and chemotherapy, performed in either an adjuvant or palliative setting, after curative surgical treatment. METHODS: Patients with scalp angiosarcoma without evidence of systemic metastasis who were treated with curative ablative surgery between 2008 and 2018 were assessed. Oncologic outcomes, including recurrence-free survival (RFS) and overall survival (OS), were evaluated. RESULTS: A total of 23 patients were analyzed. All patients underwent radical resection, most of whom (82.6%) achieved R0 resection. Adjuvant radiotherapy and chemotherapy (all taxane-based) were delivered for 11 and 3 patients, respectively. Recurrence developed in 17 (73.9%) of 23 patients during a mean follow-up period of 18.4 months. The overall 2-year RFS and OS were 15.5% and 44.4%, respectively. Multivariate analysis showed that adjuvant radiotherapy and chemotherapy were associated with a significantly low risk of recurrence. In 17 patients with recurrence, those receiving palliative radiotherapy or chemotherapy had significantly higher OS than those not receiving any treatments. Compared with patients treated during the first half of the study period, those treated during the latter part, who received adjuvant and palliative radiotherapy or chemotherapy more frequently, had significantly favorable OS, with a 2-year OS of 77.8%. CONCLUSIONS: A multidisciplinary approach using radiotherapy and/or chemotherapy combined with curative resection might be associated with better oncologic outcomes in patients with scalp angiosarcoma.

The Impact of Fibrin Sealant Volume on Skin Graft Contraction in a Full-Thickness Skin Graft Model.

BACKGROUND: Fibrin sealant has been used for skin grafting in anatomically difficult facial areas. Although biodegradable, an excess of fibrin sealant may inhibit skin graft healing by inhibiting diffusion at the graft-recipient bed interface. The impact of fibrin sealant volume on graft healing was examined in a rat full-thickness skin graft model. METHODS: Seventy-two full-thickness 2.5 × 2.5-cm skin grafts were used on the dorsum of male Sprague-Dawley rats. The grafts were treated with three different volumes of fibrin sealant placed onto the recipient bed: 0.0 mL or normal saline (group 1), 0.1 mL (group 2), and 0.4 mL (group 3). Graft healing and complications were assessed using digital photographs and necropsies on postoperative days 3, 7, and 21. RESULTS: Group 3 showed the greatest graft contraction on days 3 and 21, while group 2 showed the least contraction on all 3 postoperative days (P = 0.002, 0.004, and <0.001, respectively). Histopathologic analysis showed inflammatory foreign body reactions in group 3 on days 3 and 7, and less vascular density on day 21 (P = 0.003). Group 1 showed the highest incidence of hematoma (P = 0.004). CONCLUSION: An excess volume of fibrin sealant may produce pathologic wound contraction in skin grafting because a skin graft lacks a vascular pedicle and is highly dependent on diffusion from the host environment. Before using fibrin sealant for skin grafting in facial areas where the aesthetic outcome is important, the appropriate volume to use can be determined.

Development of a Machine-Learning Model of Short-Term Prognostic Prediction for Spinal Stenosis Surgery in Korean Patients.

BACKGROUND: In this study, based on machine-learning technology, we aim to develop a predictive model of the short-term prognosis of Korean patients who received spinal stenosis surgery. METHODS: Using the data obtained from 112 patients with spinal stenosis admitted at N hospital from February to November, 2019, a predictive analysis was conducted for the pain index, reoperation, and surgery time. RESULTS: Results show that the predicted area under the curve was 0.803, 0.887, and 0.896 for the pain index, reoperation, and surgery time, respectively, thereby indicating the accuracy of the model. CONCLUSION: This study verified that the individual characteristics of the patient and treatment characteristics during surgery enable a prediction of the patient prognosis and validate the accuracy of the approach. Further studies should be conducted to extend the scope of this research by incorporating a larger and more accurate dataset.

Postoperative pulmonary edema following vitrectomy in patients with ischemic heart disease and diastolic dysfunction in the post-anesthetic care unit: Two case reports.

RATIONALE: The increasing incidence of cardiac comorbidities in the elderly population has led to an increasing demand for vigilance of cardiac dysfunction induced by surgery. Favorable outcomes can be ensured in such cases by an increased awareness of cardiogenic complications, early identification of the problem, and appropriate treatment. PATIENT CONCERNS: This study presents 2 cases of acute pulmonary edema (PE) that were likely caused by ischemic heart disease and diastolic dysfunction in postoperative patients, following vitrectomy, in the post-anesthetic care unit. DIAGNOSES: Chest x-ray and computed tomography indicated PE. INTERVENTIONS: Following the diagnosis of PE, patients were intubated and transferred to the intensive care unit where 20 mg furosemide was injected and 10 µg/kg/min dobutamine was infused intravenously. OUTCOMES: On postoperative day 2, the patients' vital signs were stable and there were no signs of respiratory disturbance. LESSONS: Physicians should be alert to the potential development of PE as a postoperative complication in patients with left ventricular (LV) diastolic dysfunction and ischemic heart disease, even if the patient has undergone a procedure with mild hemodynamic change and minimal surgical stimulation such as vitrectomy. We propose that physicians treating elderly patients with LV diastolic dysfunction and ischemic heart disease undergoing vitrectomy should consider the use of intraoperative transthoracic echocardiogram or transesophageal echocardiogram with continuous monitoring of blood pressure, using devices such as arterial catheter devices.

Heights and spatial relationships of the facial muscles acting on the nasolabial fold by dissection and three-dimensional microcomputed tomography.

The aim of this study was to clarify the heights and spatial relationships of the facial muscles acting on the nasolabial fold (NLF) by dissection and three-dimensional microcomputed tomography for use in aesthetic treatments. This study used 56 specimens from 34 embalmed adult Korean. A reference line (RF) was set to imitate the NLF after removing the skin, from the superior point of the alar facial crease to the lateral point of the orbicularis oris muscle at the level of the corner of the mouth. The heights and spatial relationships of the facial muscles along the RF could be categorized into five main patterns. The dominant pattern was that the levator labii superioris alaeque nasi muscle (LLSAN), levator labii superioris muscle (LLS), zygomaticus minor muscle (Zmi), and zygomaticus major muscle (Zmj) were on the medial third, medial half, middle third, and lateral third of the RF, respectively. In micro-CT imaging, beneath the skin of the medial half of the NLF, the LLSAN and Zmi fibers inserted into the dermis of the NLF and adjacent to the NLF. Beneath the skin of the middle third of the NLF, the Zmi fibers were found before the muscle inserted into the dermis of the NLF and adjacent to the NLF. Beneath the skin of the lateral third of the NLF, the lateral margin of the orbicularis oris muscle and some Zmj fibers were found at the location of the NLF. The present study utilized dissections and micro-CT to reveal the general pattern and variations of heights and spatial relationships of the facial muscles passing beneath the NLF. These findings will be useful for understanding which muscles affect specific parts of NLFs with various contours, for reducing the NLF in aesthetic treatments, and for reconstructing the NLF in cases of facial paralysis.

Evaluation of natural growth rate and recommended age for shaving procedure by volumetric analysis of craniofacial fibrous dysplasia.

BACKGROUND: We evaluated the preoperative natural growth pattern of craniofacial fibrous dysplasia and postoperative volume changes in patients undergoing shaving procedures. METHODS: Thirty-three patients who underwent serial computed tomography (CT) preoperatively and/or postoperatively were identified. The natural tumor growth rate was assessed using preoperative CT scans. The postoperative tumor regrowth rates and relevant variables were analyzed. RESULTS: The preoperative tumor growth rates were significantly lower in patients aged ≥ 16 years than in those aged < 16 years (P < .001). The postoperative tumor regrowth rates were significantly greater when a shaving operation was performed at age < 16 years than at age ≥ 16 years (P = .04). In patients with clinical recurrence, the postoperative remnant tumor volume was inversely correlated with the tumor regrowth rate. CONCLUSIONS: The tumor growth rate of craniofacial fibrous dysplasia significantly decreased after age 16. This should be considered when conducting functional and aesthetic assessments in planning for the shaving of craniofacial fibrous dysplasia.

Comparison of surgical outcomes of free flap reconstructions performed by expert microsurgeons and trainees who completed a structured microsurgical training program in a teaching hospital.

BACKGROUND: Few studies have evaluated clinical outcomes of novice surgeons trained in a microsurgical training program. Herein, we describe successful free flap reconstructions performed by trainees who completed a structured microsurgical training program. METHODS: The Microsurgical Skills Training Course, a laboratory-based structured microsurgical training program, was developed and used for microsurgical training. Three trainees (postgraduate years 6 and 7) who completed the training course during residency were assigned to perform free flap reconstructions between March 2015 and February 2019. Clinical outcomes of free flap reconstruction were assessed. A retrospective propensity-score-matched analysis was performed between the trainee and expert microsurgeon groups. RESULTS: A total of 161 patients were included. Of them, 67 (25 of the trainee group and 42 of the expert group) were propensity score-matched. No flap failure developed in either matched group (p>0.999). Rates of overall complications, partial flap loss, and emergent reoperation due to vascular compromise were not significantly different between the two groups (p=0.384, p=0.525, and p=0.322, respectively), whereas those of donor complications and overall operation time were significantly higher in the trainee group than the expert group (p=0.002 and p<0.001, respectively). CONCLUSION: The use of a structured microvascular training program in qualified teaching hospitals may help trainees achieve independence as microsurgeons and favorable clinical outcomes.

Regional Lymph Node Metastasis of Scalp Angiosarcoma: A Detailed Clinical Observation Study of 40 Cases.

BACKGROUND: The incidence of lymph node metastasis (LNM) of angiosarcomas is reported to be less than 15%, and elective neck management has not been indicated. This study evaluated the incidence and pattern of regional LNM in patients with scalp angiosarcomas using the clinical data of its full course to understand time-event sequences of scalp angiosarcomas. METHODS: This retrospective study included all consecutive cases of pathology-confirmed angiosarcomas and analyzed 40 cases of scalp angiosarcomas. The survival plots were estimated using the Kaplan-Meier method, and the results are presented mainly in a descriptive manner. RESULTS: The overall survival rate for the patients was 35.8% at 2 years. In contrast to previous reports, regional LNM was observed in more than half of the patients (52.5%) with scalp angiosarcoma. Meanwhile, a direct spread to distant organs occurred in only 27.5% of the patients. Regional LNM could predict clinical manifestation of systemic disease within 3 to 6 months. No differences in survival rates between patients with and without LNM were observed in this series. Occurrence of LNM seemed to be correlated with a high mitotic rate of primary tumors, but not with tumor grade or tumor dimension. The first-echelon lymph nodes from scalp angiosarcoma were peri-parotid, post-auricular, and level 2 lymph nodes. CONCLUSIONS: For a localized scalp angiosarcoma, it seems reasonable for initial curative surgery to include prophylactic evaluation of regional lymph nodes for pathologic nodal staging, prognosis estimation, and the decision for systemic treatments.