Subxiphoid Thoracoscopic Resection of Anterior Mediastinal Tumors in Children: Preliminary Clinical Experience

Subxiphoid Thoracoscopic Resection of Anterior Mediastinal Tumors in Children: Preliminary Clinical Experience | Research Square window.SnipcartSettings = { analytics: { enabled: false } }; (function() { var accessVector = localStorage.getItem('access_vector') || ''; window.dataLayer = window.dataLayer || []; if (accessVector) { window.dataLayer.push({ user: { profile: { profileInfo: { snid: accessVector } } } }); } })(); (function(w,d,s,l,i){w[l]=w[l]||[];w[l].push({'gtm.start':new Date().getTime(),event:'gtm.js'});var f=d.getElementsByTagName(s)[0],j=d.createElement(s),dl=l!='dataLayer'?'&l='+l:'';j.async=true;j.src='https://www.googletagmanager.com/gtm.js?id='+i+dl;f.parentNode.insertBefore(j,f);})(window,document,'script','dataLayer','GTM-K279D39R'); Browse Preprints In Review Journals COVID-19 Preprints AJE Video Bytes Research Tools Research Promotion AJE Professional Editing AJE Rubriq About Preprint Platform In Review Editorial Policies Our Team Advisory Board Help Center Sign In Submit a Preprint Cite Share Download PDF Research Article Subxiphoid Thoracoscopic Resection of Anterior Mediastinal Tumors in Children: Preliminary Clinical Experience Xiao Shen, Qiqi Shi, Huifeng Zhang, Chaojun Du, Ming Ye This is a preprint; it has not been peer reviewed by a journal. https://doi.org/ 10.21203/rs.3.rs-9010676/v1 This work is licensed under a CC BY 4.0 License Status: Under Review Version 1 posted 12 You are reading this latest preprint version Abstract Objective To investigate the feasibility and short-term clinical outcomes of subxiphoid thoracoscopic surgery for the treatment of anterior mediastinal tumors in children, and to summarize the preliminary surgical experience. Methods A retrospective observational study was conducted on 4 pediatric patients who underwent subxiphoid thoracoscopic resection of anterior mediastinal tumors at our center from January 2024 to December 2024. Clinical data including pathological types, surgical procedures, intraoperative parameters, postoperative complications and their management were collected and analyzed. The inclusion criteria were central or unilateral anterior mediastinal tumors with a diameter less than 1/3 of the thoracic cavity and clear boundaries with major mediastinal blood vessels on imaging. Patients with pectus excavatum, giant tumors, or tumor invasion of major blood vessels were excluded. Results All 4 patients were male, aged 9 to 12 years. The pathological diagnoses included thymoma, mature cystic teratoma, and residual mediastinal mass after chemotherapy for T-lymphoblastic lymphoma. All surgical procedures were successfully completed via subxiphoid thoracoscopy without conversion to open thoracotomy. The median intraoperative blood loss was less than 20 mL, and no allogeneic blood transfusion was required in any patient. The median postoperative hospital stay was 7 days (range, 6–8 days). Mild postoperative complications (Clavien-Dindo grade Ⅰ) occurred in 2 patients (50%), including atelectasis and pleural effusion, all of which were completely resolved by conservative treatment or thoracostomy tube drainage without adverse effects on short-term prognosis. All tumors were resected with R0 margins, and pathological examination confirmed no residual tumor cells at the surgical margins. Conclusion Subxiphoid thoracoscopic resection is a feasible and safe minimally invasive approach for selected pediatric patients with anterior mediastinal tumors, with the advantages of mild postoperative pain, no severe perioperative complications and satisfactory short-term outcomes. However, the narrow operative space caused by the small thoracic cavity in children increases the surgical difficulty of this technique. The development of pediatric-specific auxiliary surgical instruments and the accumulation of more clinical cases are required to verify its long-term safety and efficacy. Thoracoscopy Subxiphoid approach Anterior mediastinal tumors in children Minimally invasive surgery Pediatric thoracic surgery Figures Figure 1 Figure 2 Figure 3 Figure 4 Figure 5 Figure 6 Figure 7 Figure 8 Figure 9 Figure 10 Figure 11 Figure 12 Background Anterior mediastinal tumors are relatively common intrathoracic neoplasms in children, mainly including germ cell tumors, hematolymphoid tumors and thymic tumors [ 1 ]. Due to the insidious onset and the relatively large volume of tumors at the time of diagnosis, these lesions often cause compressive symptoms such as chest tightness, chest pain, cough and dyspnea, and even invade adjacent vital structures in severe cases [ 2 ]. Surgical resection is the first-line treatment for most benign and resectable malignant anterior mediastinal tumors in children. Traditional surgical approaches include median sternotomy, lateral thoracotomy and lateral intercostal thoracoscopy [ 3 ]. Median sternotomy provides excellent surgical exposure but is associated with severe postoperative pain, high risk of sternal complications and poor cosmetic outcomes. Lateral intercostal thoracoscopy has the advantages of minimal invasion but is limited in the treatment of bilateral mediastinal lesions and large tumors [ 4 ]. In adult thoracic surgery, subxiphoid thoracoscopic surgery has been widely used for the resection of anterior mediastinal tumors, especially thymomas, due to its advantages of preserving the sternum and intercostal nerves, clear exposure of the innominate vein and the ability to resect bilateral mediastinal lesions [ 5 , 6 ]. However, relevant clinical reports on the application of this technique in pediatric thoracic surgery are rare, mainly due to the unique anatomical characteristics of children such as small thoracic cavity, narrow anterior mediastinal space and large heart-thorax ratio, which increase the surgical difficulty [ 7 ]. Our center initiated the clinical application of subxiphoid thoracoscopic resection of anterior mediastinal tumors in children in 2024. This study retrospectively analyzed the clinical data of the first 4 pediatric patients who underwent this surgery, aiming to share preliminary surgical experience and provide a reference for the clinical application of this technique in pediatric patients. Methods Study design and participants This retrospective observational study was conducted at the Department of Thoracic and Cardiovascular Surgery, Children’s Hospital of Fudan University from January 1 to December 31, 2024. All patients diagnosed with anterior mediastinal tumors and treated with subxiphoid thoracoscopic resection were enrolled. The inclusion criteria were: (1) aged 0–18 years; (2) central or unilateral anterior mediastinal tumors confirmed by chest computed tomography (CT); (3) tumor size less than 1/3 of the thoracic cavity; (4) clear boundaries with major mediastinal blood vessels on enhanced CT, without vascular invasion. The exclusion criteria were: (1) complicated with pectus excavatum or flat chest; (2) giant tumors with size more than 1/3 of the thoracic cavity; (3) tumor invasion of major blood vessels or adjacent vital structures; (4) unresectable malignant tumors; (5) severe cardiopulmonary dysfunction or other contraindications for surgery. Ethical approval This retrospective study was approved for ethics exemption by the Institutional Review Board of Children’s Hospital of Fudan University and included written informed consent from all participants’ guardians. Surgical procedure All surgical procedures were performed by the same experienced pediatric thoracic surgeon with more than 10 years of clinical experience in pediatric minimally invasive thoracic surgery. The patients were placed in the supine position with legs abducted and the back slightly elevated. Single-lumen tracheal intubation with bilateral lung ventilation was used for general anesthesia. A 2 cm longitudinal incision was made below the xiphoid process, the retrosternal space was bluntly dissected, and a 10 mm trocar was inserted to establish the camera port. Artificial pneumothorax was established with a pressure of 6 mmHg. Two 5 mm trocars were inserted at the bilateral costal arch margins about 5 cm from the subxiphoid incision as working ports. The surgeon stood between the patient's legs, and the monitor was placed at the head end of the operating table. The bilateral mediastinal pleura were incised with a harmonic scalpel to fully expose the anterior mediastinal mass and thymic tissue. The mass was carefully dissected from the surrounding connective tissue upward to the level of the left innominate vein, with special attention to protecting the bilateral phrenic nerves, brachiocephalic vein and other major blood vessels. The tumor was completely resected en bloc with the surrounding thymic tissue according to the tumor location and size. The resected specimen was placed in a specimen bag and removed through the subxiphoid incision, then sent for frozen section and postoperative pathological examination. After thorough hemostasis, the lung was fully re-expanded, and thoracic drainage tubes were placed according to the surgical situation. The incisions were sutured layer by layer after confirming no active bleeding. Data collection and follow-up Clinical data were collected from the electronic medical record system, including preoperative clinical characteristics (age, weight, chief complaint, imaging findings), intraoperative parameters (operation time, resection range, intraoperative blood loss), postoperative outcomes (pathological diagnosis, drainage volume, drainage tube indwelling time, postoperative complications, hospital stay) and short-term follow-up results. All patients were followed up for 1–3 months after discharge, and the postoperative recovery status was evaluated by outpatient reexamination. Data availability statement The datasets used and/or analysed during the current study are available from the corresponding author on reasonable request. Results Preoperative clinical characteristics A total of 4 pediatric patients were enrolled in this study, all of whom were male, aged 9 to 12 years, with a mean weight of 40.0 ± 11.2 kg. The chief complaints included quadriplegia with ptosis, cough, presternal pain and routine physical examination finding. Chest CT showed that 2 tumors were located in the right anterior mediastinum and 2 in the left anterior mediastinum, with tumor size ranging from 24×17×22 mm to 53×68×57 mm. The Haller index of all patients was 2.4–2.5, indicating no thoracic deformity. The detailed preoperative clinical characteristics are shown in Table 1. Table 1. Preoperative Clinical Characteristics Gender Age（years） Weight（kg） Chief Complaint Preoperative Imaging Tumor Location Tumor Size（mm） Haller Index Patient 1 male 11 48 Quadriplegia with ptosis for 2 months Right anterior mediastinum 50*23*43 2.4 Patient 2 male 9 31 Detected during cough examination 2 weeks ago Left anterior mediastinum 47*41*57 2.5 Patient 3 male 10 29 Residual anterior mediastinal mass 11 months after chemotherapy for T-lymphoblastic lymphoma Right anterior mediastinum 24*17*22 2.5 Patient 4 male 12 52 Presternal pain for 3 days Left anterior mediastinum 53*68*57 2.5 Intraoperative and postoperative outcomes All 4 surgical procedures were successfully completed via subxiphoid thoracoscopy without conversion to open thoracotomy. The operation time ranged from 1.0 to 3.0 hours, with a median of 2.0 hours. The resection range included the tumor with total or most of the thymic tissue; partial pericardium and left phrenic nerve were resected in 1 patient due to tumor invasion. The median intraoperative blood loss was less than 20 mL (range, 5–15 mL), and no allogeneic blood transfusion was required in any patient. Pathological examination confirmed R0 resection in all patients. The pathological diagnoses were: thymoma type B2 (1 case), mature cystic teratoma (2 cases), and residual mediastinal mass after chemotherapy for T-lymphoblastic lymphoma (1 case, no viable tumor cells found). For the 2 patients with mature cystic teratoma, pathological examination confirmed no cyst rupture, residual tissue or malignant components. The median postoperative hospital stay was 7 days (range, 6–8 days). The 3-day postoperative drainage volume ranged from 50 to 300 mL, and the drainage tube indwelling time was 2 to 5 days. Mild postoperative complications (Clavien-Dindo grade Ⅰ) occurred in 2 patients (50%): 1 patient had right lung atelectasis and bilateral minimal pleural effusion, which was resolved by 1 week of conservative treatment including oxygen inhalation, cough promotion and aerosol inhalation; 1 patient had left pleural effusion due to malposition of the thoracic drainage tube, which was improved after 2 days of thoracostomy tube drainage. No severe postoperative complications such as massive bleeding, mediastinal infection or respiratory failure occurred in any patient. All patients were discharged uneventfully and had a good short-term recovery during the follow-up period. The detailed intraoperative and postoperative outcomes are shown in Table 2. Table 2. Surgical and Postoperative Outcomes Surgical Situation Postoperative Situation Operation Time (h) Surgical Resection Range Pathology Number of Drainage Tubes Postoperative 3-day Drainage Volume（ml） Drainage Tube Placement Time（d） Postoperative Complications Management Patient 1 2 Mass and total thymus Thymoma B2 type 1 60 2 None - Patient 2 3 Mass and most of thymus Mature cystic teratoma 1 50 4 Right atelectasis, bilateral minimal pleural effusion Improved after 1 week of conservative treatment Patient 3 2.5 Mass and total thymus T-lymphoblastic lymphoma 2 300 5 None - Patient 4 4 Mass, most of thymus, part of pericardium, and left phrenic nerve Mature cystic teratoma 3 150 5 Left pleural effusion Improved after 2 days of closed thoracic drainage Discussion This study retrospectively analyzed the clinical data of 4 pediatric patients who underwent subxiphoid thoracoscopic resection of anterior mediastinal tumors, and confirmed the feasibility and safety of this technique for selected pediatric patients. As a novel minimally invasive surgical approach, subxiphoid thoracoscopy has been widely recognized in adult thoracic surgery, but its application in children is still in the exploratory stage [8]. The main findings of this study are as follows: first, subxiphoid thoracoscopic resection can achieve R0 resection of anterior mediastinal tumors in children with strict selection criteria, with minimal intraoperative blood loss and no severe perioperative complications; second, the postoperative complications of this technique are mainly related to inappropriate drainage tube placement, rather than the technical limitations of the approach itself; third, the small thoracic cavity and narrow anterior mediastinal space in children are the main challenges for this technique, and the development of pediatric-specific auxiliary instruments is urgently needed. The anatomical characteristics of children are the main factors affecting the application of subxiphoid thoracoscopic surgery in pediatric thoracic surgery. Compared with adults, children have a smaller thoracic cavity, a larger heart-thorax ratio and a narrower anterior mediastinal space, which significantly limit the operative space and the movement of surgical instruments [9]. In this study, the operation time of the 4 patients was 2.0–4.0 hours, which was longer than that of adult patients reported in previous studies [5,6], mainly due to the narrow operative space and the need for more careful dissection to avoid injury to adjacent vital structures. In addition, the compression of the right atrium and ventricle by surgical instruments or the tumor itself during the operation caused atrial premature beats in 2 patients, requiring temporary suspension of the operation until the cardiac rhythm returned to normal, which also prolonged the operation time. The learning curve of the surgical team is another important factor affecting the operation time, and the surgical efficiency is expected to be improved with the accumulation of clinical experience. Postoperative drainage management is crucial for the application of subxiphoid thoracoscopic surgery in children. Due to the small thoracic cavity and low tolerance to pleural effusion in children, inadequate drainage is easy to cause pleural effusion, atelectasis and other complications [10]. In this study, 2 patients developed postoperative complications related to drainage tube placement: 1 patient with only one anterior mediastinal drainage tube had poor drainage effect, and 1 patient had pleural effusion due to malposition of the drainage tube. After optimizing the drainage strategy (placing one thoracic drainage tube at each bilateral costal arch margin to the level of the diaphragmatic surface), no similar complications occurred in our subsequent clinical practice. For patients with pericardial resection or damage, an additional pericardial drainage tube should be placed through the subxiphoid incision to the cardiac base to prevent pericardial effusion or cardiac tamponade. We believe that individualized drainage tube placement according to the surgical situation is the key to reducing postoperative drainage-related complications. The development of pediatric-specific auxiliary surgical instruments is the key to promoting the clinical application of subxiphoid thoracoscopic surgery in children. In adult thoracic surgery, modified sternal retractors are often used to expand the anterior mediastinal operative space, which significantly reduces the surgical difficulty [11,12]. However, the intercostal space of children is significantly narrower than that of adults, and adult sternal retractors cannot be directly applied. Ding et al. [11] designed a modified sternal retractor for subxiphoid thoracoscopic surgery, which can be inserted through a small intercostal incision to expand the operative space. We believe that on the basis of adult instruments, pediatric-specific sternal retractors with reduced size and adjustable retraction force should be developed, which can effectively expand the anterior mediastinal operative space in children and improve the safety and efficiency of surgery. This study has several limitations that need to be acknowledged. First, it is a single-center retrospective study with a small sample size (only 4 patients), and no control group was set up, so the clinical value of subxiphoid thoracoscopic surgery cannot be fully compared with traditional surgical approaches. Second, the follow-up time is short (1–3 months), and no long-term follow-up data such as tumor recurrence, children's growth and development and long-term cosmetic outcomes are available, so the long-term safety and efficacy of this technique need to be further verified. Third, all enrolled patients were male, and the applicability of this technique to female children needs to be confirmed by more clinical cases. Fourth, the study only included patients with small and medium-sized tumors with clear boundaries, and the feasibility and safety of this technique for giant or invasive anterior mediastinal tumors in children need to be further explored. Conclusion Subxiphoid thoracoscopic resection is a feasible and safe minimally invasive approach for selected pediatric patients with anterior mediastinal tumors (small and medium-sized, clear boundaries, no vascular invasion), with the advantages of minimal intraoperative blood loss, mild postoperative pain, no severe perioperative complications and satisfactory short-term outcomes. Postoperative drainage-related complications are the main short-term adverse events, which can be effectively reduced by optimizing the drainage strategy. The small thoracic cavity and narrow anterior mediastinal space in children increase the surgical difficulty of this technique, and the development of pediatric-specific auxiliary surgical instruments is urgently needed. Multicenter, large-sample and long-term follow-up studies are required to further verify the long-term safety and efficacy of this technique and to clarify its clinical application scope in pediatric thoracic surgery. Declarations Ethical approval This retrospective study was approved for ethics exemption by the Institutional Review Board of Children’s Hospital of Fudan University and included written informed consent from all participants’ guardians. Conflict of Interest Statement The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper. Funding This study was supported by the National Clinical Key Specialty Construction Project (Project Code: 10000015Z155080000004). Author Contribution Xiao Shen and Qiqi Shi contributed equally to this work as co-first authors. Xiao Shen and Ming Ye designed the study and drafted the manuscript; Huifeng Zhang collected and analyzed the clinical data; Chaojun Du revised the manuscript critically for important intellectual content. All authors read and approved the final version of the manuscript and agreed to submit it for publication. Data Availability The datasets used and/or analysed during the current study are available from the corresponding author on reasonable request. References Verma S. Kaushal Kalra. Clinical approach to childhood mediastinal tumors and management. Mediastinum. 2020;4(0):21. Partrick DA, Rothenberg SS. Thoracoscopic Resection of Mediastinal Masses in Infants and Children: An Evaluation of Technique and Results. J Pediatr Surg. 2001;36(8):1165–7. Chen X, Ma Q. Subxiphoid and subcostal thoracoscopic surgical approach for thymectomy. Surg Endosc. 2021;35(9):5239–46. Koga H. Atsuyuki, Yamataka. Median sternotomy provides excellent exposure for excising anterior mediastinal tumors in children. Pediatr Surg Int. 2005;21:864–7. Leng X, Chen M. Choosing the proper path: outcomes of subxiphoid vs. lateral intercostal approaches in the resection of anterior mediastinal masses. Front Surg. 2024;11(0):1463881. Wang J, Tong T. Clinical study of thoracoscopic assisted different surgical approaches for early thymoma: a meta-analysis. BMC Cancer. 2024;24(1):92. Mao Y, Lan Y. Comparison of different surgical approaches for anterior mediastinal tumor. J Thorac Dis. 2020;12(10):5430–9. Wang S. Subxiphoid versus lateral intercostal thoracoscopic thymectomy for suspected thymoma: Results of a randomized controlled trial. J Thorac Cardiovasc Surg. 2024;168(1):290–8. Jiang JH, Ding JY. Modified Subxiphoid Thoracoscopic Thymectomy for Locally Invasive Thymoma. Ann Thorac Surg. 2021;112(4):1095–100. Mao T, Fang W. A uniport subxiphoid approach with a modified sternum retractor is safe and feasible for anterior mediastinal tumors. J Thorac Dis. 2023;15(3):1364–72. Song N. Double sternal elevation subxiphoid versus uniportal thoracoscopic thymectomy associated with superior clearance for stage I-II thymic epithelial tumors: Subxiphoid thymectomy compared with VATS. Surgery. 2022;172(1):371–8. Additional Declarations No competing interests reported. Supplementary Files VideoofThoracoscopicSurgeryforPatient3.mp4 Cite Share Download PDF Status: Under Review Version 1 posted Editorial decision: Revision requested 06 Apr, 2026 Reviews received at journal 30 Mar, 2026 Reviewers agreed at journal 30 Mar, 2026 Reviews received at journal 30 Mar, 2026 Reviewers agreed at journal 30 Mar, 2026 Reviewers agreed at journal 28 Mar, 2026 Reviewers agreed at journal 28 Mar, 2026 Reviewers agreed at journal 28 Mar, 2026 Reviewers invited by journal 28 Mar, 2026 Editor assigned by journal 10 Mar, 2026 Submission checks completed at journal 10 Mar, 2026 First submitted to journal 02 Mar, 2026 You are reading this latest preprint version Research Square lets you share your work early, gain feedback from the community, and start making changes to your manuscript prior to peer review in a journal. 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7","display":"","copyAsset":false,"role":"figure","size":342137,"visible":true,"origin":"","legend":"\u003cp\u003ePreoperative chest CT scans of Patient 4 displaying a left anterior mediastinal mass, clinically diagnosed as teratoma.\u003c/p\u003e","description":"","filename":"Figure7.png","url":"https://assets-eu.researchsquare.com/files/rs-9010676/v1/1ccef852fdc48c2cf136ef1b.png"},{"id":106723999,"identity":"fe089790-151d-463e-b7e2-074a574b2b72","added_by":"auto","created_at":"2026-04-12 18:23:30","extension":"png","order_by":8,"title":"Figure 8","display":"","copyAsset":false,"role":"figure","size":334739,"visible":true,"origin":"","legend":"\u003cp\u003ePreoperative chest CT scans of Patient 4 displaying a left anterior mediastinal mass, clinically diagnosed as teratoma.\u003c/p\u003e","description":"","filename":"Figure8.png","url":"https://assets-eu.researchsquare.com/files/rs-9010676/v1/95bf21ef454f83c6f8fe1d29.png"},{"id":106415576,"identity":"18dcf4d8-d4da-4ce7-8ff9-7a458c7cb860","added_by":"auto","created_at":"2026-04-08 10:35:10","extension":"jpg","order_by":9,"title":"Figure 9","display":"","copyAsset":false,"role":"figure","size":180682,"visible":true,"origin":"","legend":"\u003cp\u003ePreoperative incision marking and postoperative drainage tube placement in Patient 3.\u003c/p\u003e","description":"","filename":"Figure9.jpg","url":"https://assets-eu.researchsquare.com/files/rs-9010676/v1/8695d59e9b72fa14613cd721.jpg"},{"id":106415451,"identity":"61ab52ef-f1f2-42fa-8d05-bdfb87798e95","added_by":"auto","created_at":"2026-04-08 10:34:21","extension":"jpg","order_by":10,"title":"Figure 10","display":"","copyAsset":false,"role":"figure","size":135243,"visible":true,"origin":"","legend":"\u003cp\u003ePreoperative incision marking and postoperative drainage tube placement in Patient 3.\u003c/p\u003e","description":"","filename":"Figure10.jpg","url":"https://assets-eu.researchsquare.com/files/rs-9010676/v1/5bd9c36211247f253449bd10.jpg"},{"id":106415579,"identity":"1c55e00c-6aa1-4c24-91fa-4a07bfb7d872","added_by":"auto","created_at":"2026-04-08 10:35:11","extension":"jpg","order_by":11,"title":"Figure 11","display":"","copyAsset":false,"role":"figure","size":95115,"visible":true,"origin":"","legend":"\u003cp\u003ePreoperative incision marking and postoperative drainage tube placement in Patient 4.\u003c/p\u003e","description":"","filename":"Figure11.jpg","url":"https://assets-eu.researchsquare.com/files/rs-9010676/v1/9a5497ba9fce828c16897dcf.jpg"},{"id":106415578,"identity":"f94ea2a8-4ce8-41db-9478-2f2d86dbf33c","added_by":"auto","created_at":"2026-04-08 10:35:11","extension":"jpg","order_by":12,"title":"Figure 12","display":"","copyAsset":false,"role":"figure","size":141532,"visible":true,"origin":"","legend":"\u003cp\u003ePreoperative incision marking and postoperative drainage tube placement in Patient 4.\u003c/p\u003e","description":"","filename":"Figure12.jpg","url":"https://assets-eu.researchsquare.com/files/rs-9010676/v1/67709471c6bed2c60abe2f87.jpg"},{"id":106962704,"identity":"c8e70577-295f-497d-a3e0-dfff5272c73a","added_by":"auto","created_at":"2026-04-15 09:39:34","extension":"pdf","order_by":0,"title":"","display":"","copyAsset":false,"role":"manuscript-pdf","size":9421927,"visible":true,"origin":"","legend":"","description":"","filename":"manuscript.pdf","url":"https://assets-eu.researchsquare.com/files/rs-9010676/v1/09271e54-ceee-45f4-8880-e6394625b5d9.pdf"},{"id":106415488,"identity":"161eff63-bdc4-4e17-9e7c-853ddc0f35f1","added_by":"auto","created_at":"2026-04-08 10:34:30","extension":"mp4","order_by":1,"title":"","display":"","copyAsset":false,"role":"supplement","size":33306595,"visible":true,"origin":"","legend":"","description":"","filename":"VideoofThoracoscopicSurgeryforPatient3.mp4","url":"https://assets-eu.researchsquare.com/files/rs-9010676/v1/e5c67564bb59d22cf472d8db.mp4"}],"financialInterests":"No competing interests reported.","formattedTitle":"Subxiphoid Thoracoscopic Resection of Anterior Mediastinal Tumors in Children: Preliminary Clinical Experience","fulltext":[{"header":"Background","content":"\u003cp\u003eAnterior mediastinal tumors are relatively common intrathoracic neoplasms in children, mainly including germ cell tumors, hematolymphoid tumors and thymic tumors [\u003cspan citationid=\"CR1\" class=\"CitationRef\"\u003e1\u003c/span\u003e]. Due to the insidious onset and the relatively large volume of tumors at the time of diagnosis, these lesions often cause compressive symptoms such as chest tightness, chest pain, cough and dyspnea, and even invade adjacent vital structures in severe cases [\u003cspan citationid=\"CR2\" class=\"CitationRef\"\u003e2\u003c/span\u003e]. Surgical resection is the first-line treatment for most benign and resectable malignant anterior mediastinal tumors in children. Traditional surgical approaches include median sternotomy, lateral thoracotomy and lateral intercostal thoracoscopy [\u003cspan citationid=\"CR3\" class=\"CitationRef\"\u003e3\u003c/span\u003e]. Median sternotomy provides excellent surgical exposure but is associated with severe postoperative pain, high risk of sternal complications and poor cosmetic outcomes. Lateral intercostal thoracoscopy has the advantages of minimal invasion but is limited in the treatment of bilateral mediastinal lesions and large tumors [\u003cspan citationid=\"CR4\" class=\"CitationRef\"\u003e4\u003c/span\u003e].\u003c/p\u003e \u003cp\u003eIn adult thoracic surgery, subxiphoid thoracoscopic surgery has been widely used for the resection of anterior mediastinal tumors, especially thymomas, due to its advantages of preserving the sternum and intercostal nerves, clear exposure of the innominate vein and the ability to resect bilateral mediastinal lesions [\u003cspan citationid=\"CR5\" class=\"CitationRef\"\u003e5\u003c/span\u003e, \u003cspan citationid=\"CR6\" class=\"CitationRef\"\u003e6\u003c/span\u003e]. However, relevant clinical reports on the application of this technique in pediatric thoracic surgery are rare, mainly due to the unique anatomical characteristics of children such as small thoracic cavity, narrow anterior mediastinal space and large heart-thorax ratio, which increase the surgical difficulty [\u003cspan citationid=\"CR7\" class=\"CitationRef\"\u003e7\u003c/span\u003e]. Our center initiated the clinical application of subxiphoid thoracoscopic resection of anterior mediastinal tumors in children in 2024. This study retrospectively analyzed the clinical data of the first 4 pediatric patients who underwent this surgery, aiming to share preliminary surgical experience and provide a reference for the clinical application of this technique in pediatric patients.\u003c/p\u003e"},{"header":"Methods","content":"\u003cp\u003e\u003cstrong\u003eStudy design and participants\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThis retrospective observational study was conducted at the Department of Thoracic and Cardiovascular Surgery, Children\u0026rsquo;s Hospital of Fudan University from January 1 to December 31, 2024. All patients diagnosed with anterior mediastinal tumors and treated with subxiphoid thoracoscopic resection were enrolled. The inclusion criteria were: (1) aged 0\u0026ndash;18 years; (2) central or unilateral anterior mediastinal tumors confirmed by chest computed tomography (CT); (3) tumor size less than 1/3 of the thoracic cavity; (4) clear boundaries with major mediastinal blood vessels on enhanced CT, without vascular invasion. The exclusion criteria were: (1) complicated with pectus excavatum or flat chest; (2) giant tumors with size more than 1/3 of the thoracic cavity; (3) tumor invasion of major blood vessels or adjacent vital structures; (4) unresectable malignant tumors; (5) severe cardiopulmonary dysfunction or other contraindications for surgery.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eEthical approval\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThis retrospective study was approved for ethics exemption by the Institutional Review Board of Children\u0026rsquo;s Hospital of Fudan University and included written informed consent from all participants\u0026rsquo; guardians.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eSurgical procedure\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eAll surgical procedures were performed by the same experienced pediatric thoracic surgeon with more than 10 years of clinical experience in pediatric minimally invasive thoracic surgery. The patients were placed in the supine position with legs abducted and the back slightly elevated. Single-lumen tracheal intubation with bilateral lung ventilation was used for general anesthesia. A 2 cm longitudinal incision was made below the xiphoid process, the retrosternal space was bluntly dissected, and a 10 mm trocar was inserted to establish the camera port. Artificial pneumothorax was established with a pressure of 6 mmHg. Two 5 mm trocars were inserted at the bilateral costal arch margins about 5 cm from the subxiphoid incision as working ports. The surgeon stood between the patient\u0026apos;s legs, and the monitor was placed at the head end of the operating table.\u003c/p\u003e\n\u003cp\u003eThe bilateral mediastinal pleura were incised with a harmonic scalpel to fully expose the anterior mediastinal mass and thymic tissue. The mass was carefully dissected from the surrounding connective tissue upward to the level of the left innominate vein, with special attention to protecting the bilateral phrenic nerves, brachiocephalic vein and other major blood vessels. The tumor was completely resected en bloc with the surrounding thymic tissue according to the tumor location and size. The resected specimen was placed in a specimen bag and removed through the subxiphoid incision, then sent for frozen section and postoperative pathological examination. After thorough hemostasis, the lung was fully re-expanded, and thoracic drainage tubes were placed according to the surgical situation. The incisions were sutured layer by layer after confirming no active bleeding.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eData collection and follow-up\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eClinical data were collected from the electronic medical record system, including preoperative clinical characteristics (age, weight, chief complaint, imaging findings), intraoperative parameters (operation time, resection range, intraoperative blood loss), postoperative outcomes (pathological diagnosis, drainage volume, drainage tube indwelling time, postoperative complications, hospital stay) and short-term follow-up results. All patients were followed up for 1\u0026ndash;3 months after discharge, and the postoperative recovery status was evaluated by outpatient reexamination.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eData availability statement\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThe datasets used and/or analysed during the current study are available from the corresponding author on reasonable request.\u003c/p\u003e"},{"header":"Results","content":"\u003cp\u003ePreoperative clinical characteristics\u003c/p\u003e\n\u003cp\u003eA total of 4 pediatric patients were enrolled in this study, all of whom were male, aged 9 to 12 years, with a mean weight of 40.0 \u0026plusmn; 11.2 kg. The chief complaints included quadriplegia with ptosis, cough, presternal pain and routine physical examination finding. Chest CT showed that 2 tumors were located in the right anterior mediastinum and 2 in the left anterior mediastinum, with tumor size ranging from 24\u0026times;17\u0026times;22 mm to 53\u0026times;68\u0026times;57 mm. The Haller index of all patients was 2.4\u0026ndash;2.5, indicating no thoracic deformity. The detailed preoperative clinical characteristics are shown in Table 1.\u003c/p\u003e\n\u003ctable border=\"1\" cellspacing=\"0\" cellpadding=\"0\" width=\"557\"\u003e\n \u003ctbody\u003e\n \u003ctr\u003e\n \u003ctd colspan=\"8\" valign=\"top\" style=\"width: 557px;\"\u003e\n \u003cp\u003e\u003cstrong\u003eTable 1. Preoperative Clinical Characteristics\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd rowspan=\"2\" valign=\"top\" style=\"width: 59px;\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd rowspan=\"2\" valign=\"top\" style=\"width: 61px;\"\u003e\n \u003cp\u003eGender\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd rowspan=\"2\" valign=\"top\" style=\"width: 51px;\"\u003e\n \u003cp\u003eAge（years）\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd rowspan=\"2\" valign=\"top\" style=\"width: 60px;\"\u003e\n \u003cp\u003eWeight（kg）\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd rowspan=\"2\" valign=\"top\" style=\"width: 105px;\"\u003e\n \u003cp\u003eChief Complaint\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd colspan=\"3\" valign=\"top\" style=\"width: 221px;\"\u003e\n \u003cp\u003ePreoperative Imaging\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 96px;\"\u003e\n \u003cp\u003eTumor Location\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 74px;\"\u003e\n \u003cp\u003eTumor Size（mm）\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 52px;\"\u003e\n \u003cp\u003eHaller Index\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 59px;\"\u003e\n \u003cp\u003ePatient 1\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 61px;\"\u003e\n \u003cp\u003emale\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 51px;\"\u003e\n \u003cp\u003e11\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 60px;\"\u003e\n \u003cp\u003e48\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 105px;\"\u003e\n \u003cp\u003eQuadriplegia with ptosis for 2 months\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 96px;\"\u003e\n \u003cp\u003eRight anterior mediastinum\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 74px;\"\u003e\n \u003cp\u003e50*23*43\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 52px;\"\u003e\n \u003cp\u003e2.4\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 59px;\"\u003e\n \u003cp\u003ePatient 2\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 61px;\"\u003e\n \u003cp\u003emale\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 51px;\"\u003e\n \u003cp\u003e9\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 60px;\"\u003e\n \u003cp\u003e31\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 105px;\"\u003e\n \u003cp\u003eDetected during cough examination 2 weeks ago\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 96px;\"\u003e\n \u003cp\u003eLeft anterior mediastinum\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 74px;\"\u003e\n \u003cp\u003e47*41*57\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 52px;\"\u003e\n \u003cp\u003e2.5\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 59px;\"\u003e\n \u003cp\u003ePatient 3\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 61px;\"\u003e\n \u003cp\u003emale\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 51px;\"\u003e\n \u003cp\u003e10\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 60px;\"\u003e\n \u003cp\u003e29\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 105px;\"\u003e\n \u003cp\u003eResidual anterior mediastinal mass 11 months after chemotherapy for T-lymphoblastic lymphoma\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 96px;\"\u003e\n \u003cp\u003eRight anterior mediastinum\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 74px;\"\u003e\n \u003cp\u003e24*17*22\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 52px;\"\u003e\n \u003cp\u003e2.5\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 59px;\"\u003e\n \u003cp\u003ePatient 4\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 61px;\"\u003e\n \u003cp\u003emale\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 51px;\"\u003e\n \u003cp\u003e12\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 60px;\"\u003e\n \u003cp\u003e52\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 105px;\"\u003e\n \u003cp\u003ePresternal pain for 3 days\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 96px;\"\u003e\n \u003cp\u003eLeft anterior mediastinum\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 74px;\"\u003e\n \u003cp\u003e53*68*57\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 52px;\"\u003e\n \u003cp\u003e2.5\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003c/tbody\u003e\n\u003c/table\u003e\n\u003cp\u003eIntraoperative and postoperative outcomes\u003c/p\u003e\n\u003cp\u003eAll 4 surgical procedures were successfully completed via subxiphoid thoracoscopy without conversion to open thoracotomy. The operation time ranged from 1.0 to 3.0 hours, with a median of 2.0 hours. The resection range included the tumor with total or most of the thymic tissue; partial pericardium and left phrenic nerve were resected in 1 patient due to tumor invasion. The median intraoperative blood loss was less than 20 mL (range, 5\u0026ndash;15 mL), and no allogeneic blood transfusion was required in any patient.\u003c/p\u003e\n\u003cp\u003ePathological examination confirmed R0 resection in all patients. The pathological diagnoses were: thymoma type B2 (1 case), mature cystic teratoma (2 cases), and residual mediastinal mass after chemotherapy for T-lymphoblastic lymphoma (1 case, no viable tumor cells found). For the 2 patients with mature cystic teratoma, pathological examination confirmed no cyst rupture, residual tissue or malignant components.\u003c/p\u003e\n\u003cp\u003eThe median postoperative hospital stay was 7 days (range, 6\u0026ndash;8 days). The 3-day postoperative drainage volume ranged from 50 to 300 mL, and the drainage tube indwelling time was 2 to 5 days. Mild postoperative complications (Clavien-Dindo grade Ⅰ) occurred in 2 patients (50%): 1 patient had right lung atelectasis and bilateral minimal pleural effusion, which was resolved by 1 week of conservative treatment including oxygen inhalation, cough promotion and aerosol inhalation; 1 patient had left pleural effusion due to malposition of the thoracic drainage tube, which was improved after 2 days of thoracostomy tube drainage. No severe postoperative complications such as massive bleeding, mediastinal infection or respiratory failure occurred in any patient. All patients were discharged uneventfully and had a good short-term recovery during the follow-up period. The detailed intraoperative and postoperative outcomes are shown in Table 2.\u003c/p\u003e\n\u003ctable border=\"1\" cellspacing=\"0\" cellpadding=\"0\"\u003e\n \u003ctbody\u003e\n \u003ctr\u003e\n \u003ctd colspan=\"9\" valign=\"top\" style=\"width: 553px;\"\u003e\n \u003cp\u003e\u003cstrong\u003eTable 2. Surgical and Postoperative Outcomes\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd rowspan=\"2\" valign=\"top\" style=\"width: 43px;\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd colspan=\"3\" valign=\"top\" style=\"width: 192px;\"\u003e\n \u003cp\u003e\u003cstrong\u003eSurgical Situation\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd colspan=\"5\" valign=\"top\" style=\"width: 319px;\"\u003e\n \u003cp\u003e\u003cstrong\u003ePostoperative Situation\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 56px;\"\u003e\n \u003cp\u003eOperation Time (h)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 65px;\"\u003e\n \u003cp\u003eSurgical Resection Range\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 71px;\"\u003e\n \u003cp\u003ePathology\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 51px;\"\u003e\n \u003cp\u003eNumber of Drainage Tubes\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 70px;\"\u003e\n \u003cp\u003ePostoperative 3-day Drainage Volume（ml）\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 57px;\"\u003e\n \u003cp\u003eDrainage Tube Placement Time（d）\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 72px;\"\u003e\n \u003cp\u003ePostoperative Complications\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 69px;\"\u003e\n \u003cp\u003eManagement\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 43px;\"\u003e\n \u003cp\u003ePatient 1\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 56px;\"\u003e\n \u003cp\u003e2\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 65px;\"\u003e\n \u003cp\u003eMass and total thymus\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 71px;\"\u003e\n \u003cp\u003eThymoma B2 type\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 51px;\"\u003e\n \u003cp\u003e1\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 70px;\"\u003e\n \u003cp\u003e60\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 57px;\"\u003e\n \u003cp\u003e2\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 72px;\"\u003e\n \u003cp\u003eNone\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 69px;\"\u003e\n \u003cp\u003e-\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 43px;\"\u003e\n \u003cp\u003ePatient 2\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 56px;\"\u003e\n \u003cp\u003e3\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 65px;\"\u003e\n \u003cp\u003eMass and most of thymus\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 71px;\"\u003e\n \u003cp\u003eMature cystic teratoma\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 51px;\"\u003e\n \u003cp\u003e1\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 70px;\"\u003e\n \u003cp\u003e50\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 57px;\"\u003e\n \u003cp\u003e4\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 72px;\"\u003e\n \u003cp\u003eRight atelectasis, bilateral minimal pleural effusion\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 69px;\"\u003e\n \u003cp\u003eImproved after 1 week of conservative treatment\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 43px;\"\u003e\n \u003cp\u003ePatient 3\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 56px;\"\u003e\n \u003cp\u003e2.5\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 65px;\"\u003e\n \u003cp\u003eMass and total thymus\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 71px;\"\u003e\n \u003cp\u003eT-lymphoblastic lymphoma\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 51px;\"\u003e\n \u003cp\u003e2\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 70px;\"\u003e\n \u003cp\u003e300\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 57px;\"\u003e\n \u003cp\u003e5\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 72px;\"\u003e\n \u003cp\u003eNone\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 69px;\"\u003e\n \u003cp\u003e-\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 43px;\"\u003e\n \u003cp\u003ePatient 4\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 56px;\"\u003e\n \u003cp\u003e4\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 65px;\"\u003e\n \u003cp\u003eMass, most of thymus, part of pericardium, and left phrenic nerve\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 71px;\"\u003e\n \u003cp\u003eMature cystic teratoma\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 51px;\"\u003e\n \u003cp\u003e3\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 70px;\"\u003e\n \u003cp\u003e150\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 57px;\"\u003e\n \u003cp\u003e5\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 72px;\"\u003e\n \u003cp\u003eLeft pleural effusion\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 69px;\"\u003e\n \u003cp\u003eImproved after 2 days of closed thoracic drainage\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003c/tbody\u003e\n\u003c/table\u003e"},{"header":"Discussion","content":"\u003cp\u003eThis study retrospectively analyzed the clinical data of 4 pediatric patients who underwent subxiphoid thoracoscopic resection of anterior mediastinal tumors, and confirmed the feasibility and safety of this technique for selected pediatric patients. As a novel minimally invasive surgical approach, subxiphoid thoracoscopy has been widely recognized in adult thoracic surgery, but its application in children is still in the exploratory stage [8]. The main findings of this study are as follows: first, subxiphoid thoracoscopic resection can achieve R0 resection of anterior mediastinal tumors in children with strict selection criteria, with minimal intraoperative blood loss and no severe perioperative complications; second, the postoperative complications of this technique are mainly related to inappropriate drainage tube placement, rather than the technical limitations of the approach itself; third, the small thoracic cavity and narrow anterior mediastinal space in children are the main challenges for this technique, and the development of pediatric-specific auxiliary instruments is urgently needed.\u003c/p\u003e\n\u003cp\u003eThe anatomical characteristics of children are the main factors affecting the application of subxiphoid thoracoscopic surgery in pediatric thoracic surgery. Compared with adults, children have a smaller thoracic cavity, a larger heart-thorax ratio and a narrower anterior mediastinal space, which significantly limit the operative space and the movement of surgical instruments [9]. In this study, the operation time of the 4 patients was 2.0\u0026ndash;4.0 hours, which was longer than that of adult patients reported in previous studies [5,6], mainly due to the narrow operative space and the need for more careful dissection to avoid injury to adjacent vital structures. In addition, the compression of the right atrium and ventricle by surgical instruments or the tumor itself during the operation caused atrial premature beats in 2 patients, requiring temporary suspension of the operation until the cardiac rhythm returned to normal, which also prolonged the operation time. The learning curve of the surgical team is another important factor affecting the operation time, and the surgical efficiency is expected to be improved with the accumulation of clinical experience.\u003c/p\u003e\n\u003cp\u003ePostoperative drainage management is crucial for the application of subxiphoid thoracoscopic surgery in children. Due to the small thoracic cavity and low tolerance to pleural effusion in children, inadequate drainage is easy to cause pleural effusion, atelectasis and other complications [10]. In this study, 2 patients developed postoperative complications related to drainage tube placement: 1 patient with only one anterior mediastinal drainage tube had poor drainage effect, and 1 patient had pleural effusion due to malposition of the drainage tube. After optimizing the drainage strategy (placing one thoracic drainage tube at each bilateral costal arch margin to the level of the diaphragmatic surface), no similar complications occurred in our subsequent clinical practice. For patients with pericardial resection or damage, an additional pericardial drainage tube should be placed through the subxiphoid incision to the cardiac base to prevent pericardial effusion or cardiac tamponade. We believe that individualized drainage tube placement according to the surgical situation is the key to reducing postoperative drainage-related complications.\u003c/p\u003e\n\u003cp\u003eThe development of pediatric-specific auxiliary surgical instruments is the key to promoting the clinical application of subxiphoid thoracoscopic surgery in children. In adult thoracic surgery, modified sternal retractors are often used to expand the anterior mediastinal operative space, which significantly reduces the surgical difficulty [11,12]. However, the intercostal space of children is significantly narrower than that of adults, and adult sternal retractors cannot be directly applied. Ding et al. [11] designed a modified sternal retractor for subxiphoid thoracoscopic surgery, which can be inserted through a small intercostal incision to expand the operative space. We believe that on the basis of adult instruments, pediatric-specific sternal retractors with reduced size and adjustable retraction force should be developed, which can effectively expand the anterior mediastinal operative space in children and improve the safety and efficiency of surgery.\u003c/p\u003e\n\u003cp\u003eThis study has several limitations that need to be acknowledged. First, it is a single-center retrospective study with a small sample size (only 4 patients), and no control group was set up, so the clinical value of subxiphoid thoracoscopic surgery cannot be fully compared with traditional surgical approaches. Second, the follow-up time is short (1\u0026ndash;3 months), and no long-term follow-up data such as tumor recurrence, children\u0026apos;s growth and development and long-term cosmetic outcomes are available, so the long-term safety and efficacy of this technique need to be further verified. Third, all enrolled patients were male, and the applicability of this technique to female children needs to be confirmed by more clinical cases. Fourth, the study only included patients with small and medium-sized tumors with clear boundaries, and the feasibility and safety of this technique for giant or invasive anterior mediastinal tumors in children need to be further explored.\u003c/p\u003e"},{"header":"Conclusion","content":"\u003cp\u003eSubxiphoid thoracoscopic resection is a feasible and safe minimally invasive approach for selected pediatric patients with anterior mediastinal tumors (small and medium-sized, clear boundaries, no vascular invasion), with the advantages of minimal intraoperative blood loss, mild postoperative pain, no severe perioperative complications and satisfactory short-term outcomes. Postoperative drainage-related complications are the main short-term adverse events, which can be effectively reduced by optimizing the drainage strategy. The small thoracic cavity and narrow anterior mediastinal space in children increase the surgical difficulty of this technique, and the development of pediatric-specific auxiliary surgical instruments is urgently needed. Multicenter, large-sample and long-term follow-up studies are required to further verify the long-term safety and efficacy of this technique and to clarify its clinical application scope in pediatric thoracic surgery.\u003c/p\u003e"},{"header":"Declarations","content":"\u003cp\u003e \u003ch2\u003eEthical approval\u003c/h2\u003e \u003cp\u003e This retrospective study was approved for ethics exemption by the Institutional Review Board of Children\u0026rsquo;s Hospital of Fudan University and included written informed consent from all participants\u0026rsquo; guardians.\u003c/p\u003e \u003ch2\u003eConflict of Interest Statement\u003c/h2\u003e \u003cp\u003eThe authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper.\u003c/p\u003e \u003c/p\u003e\u003ch2\u003eFunding\u003c/h2\u003e \u003cp\u003eThis study was supported by the National Clinical Key Specialty Construction Project (Project Code: 10000015Z155080000004).\u003c/p\u003e\u003ch2\u003eAuthor Contribution\u003c/h2\u003e\u003cp\u003eXiao Shen and Qiqi Shi contributed equally to this work as co-first authors. Xiao Shen and Ming Ye designed the study and drafted the manuscript; Huifeng Zhang collected and analyzed the clinical data; Chaojun Du revised the manuscript critically for important intellectual content. All authors read and approved the final version of the manuscript and agreed to submit it for publication.\u003c/p\u003e\u003ch2\u003eData Availability\u003c/h2\u003e\u003cp\u003eThe datasets used and/or analysed during the current study are available from the corresponding author on reasonable request.\u003c/p\u003e"},{"header":"References","content":"\u003col\u003e\u003cli\u003e\u003cspan\u003eVerma S. Kaushal Kalra. Clinical approach to childhood mediastinal tumors and management. Mediastinum. 2020;4(0):21.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003ePartrick DA, Rothenberg SS. Thoracoscopic Resection of Mediastinal Masses in Infants and Children: An Evaluation of Technique and Results. J Pediatr Surg. 2001;36(8):1165\u0026ndash;7.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eChen X, Ma Q. Subxiphoid and subcostal thoracoscopic surgical approach for thymectomy. Surg Endosc. 2021;35(9):5239\u0026ndash;46.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eKoga H. Atsuyuki, Yamataka. Median sternotomy provides excellent exposure for excising anterior mediastinal tumors in children. Pediatr Surg Int. 2005;21:864\u0026ndash;7.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eLeng X, Chen M. Choosing the proper path: outcomes of subxiphoid vs. lateral intercostal approaches in the resection of anterior mediastinal masses. Front Surg. 2024;11(0):1463881.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eWang J, Tong T. Clinical study of thoracoscopic assisted different surgical approaches for early thymoma: a meta-analysis. BMC Cancer. 2024;24(1):92.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eMao Y, Lan Y. Comparison of different surgical approaches for anterior mediastinal tumor. J Thorac Dis. 2020;12(10):5430\u0026ndash;9.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eWang S. Subxiphoid versus lateral intercostal thoracoscopic thymectomy for suspected thymoma: Results of a randomized controlled trial. J Thorac Cardiovasc Surg. 2024;168(1):290\u0026ndash;8.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eJiang JH, Ding JY. Modified Subxiphoid Thoracoscopic Thymectomy for Locally Invasive Thymoma. Ann Thorac Surg. 2021;112(4):1095\u0026ndash;100.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eMao T, Fang W. A uniport subxiphoid approach with a modified sternum retractor is safe and feasible for anterior mediastinal tumors. J Thorac Dis. 2023;15(3):1364\u0026ndash;72.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eSong N. Double sternal elevation subxiphoid versus uniportal thoracoscopic thymectomy associated with superior clearance for stage I-II thymic epithelial tumors: Subxiphoid thymectomy compared with VATS. Surgery. 2022;172(1):371\u0026ndash;8.\u003c/span\u003e\u003c/li\u003e\u003c/ol\u003e"}],"fulltextSource":"","fullText":"","funders":[],"hasAdminPriorityOnWorkflow":false,"hasManuscriptDocX":true,"hasOptedInToPreprint":true,"hasPassedJournalQc":"","hasAnyPriority":false,"hideJournal":false,"highlight":"","institution":"","isAcceptedByJournal":true,"isAuthorSuppliedPdf":false,"isDeskRejected":"","isHiddenFromSearch":false,"isInQc":false,"isInWorkflow":false,"isPdf":false,"isPdfUpToDate":true,"isWithdrawnOrRetracted":false,"journal":{"display":true,"email":"[email protected]","identity":"journal-of-cardiothoracic-surgery","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":false,"externalIdentity":"jcts","sideBox":"Learn more about [Journal of Cardiothoracic Surgery](http://cardiothoracicsurgery.biomedcentral.com)","snPcode":"13019","submissionUrl":"https://submission.nature.com/new-submission/13019/3","title":"Journal of Cardiothoracic Surgery","twitterHandle":"@BioMedCentral","acdcEnabled":true,"dfaEnabled":true,"editorialSystem":"em","reportingPortfolio":"BMC/SO AJ","inReviewEnabled":true,"inReviewRevisionsEnabled":true},"keywords":"Thoracoscopy, Subxiphoid approach, Anterior mediastinal tumors in children, Minimally invasive surgery, Pediatric thoracic surgery","lastPublishedDoi":"10.21203/rs.3.rs-9010676/v1","lastPublishedDoiUrl":"https://doi.org/10.21203/rs.3.rs-9010676/v1","license":{"name":"CC BY 4.0","url":"https://creativecommons.org/licenses/by/4.0/"},"manuscriptAbstract":"\u003ch2\u003eObjective\u003c/h2\u003e \u003cp\u003eTo investigate the feasibility and short-term clinical outcomes of subxiphoid thoracoscopic surgery for the treatment of anterior mediastinal tumors in children, and to summarize the preliminary surgical experience.\u003c/p\u003e\u003ch2\u003eMethods\u003c/h2\u003e \u003cp\u003eA retrospective observational study was conducted on 4 pediatric patients who underwent subxiphoid thoracoscopic resection of anterior mediastinal tumors at our center from January 2024 to December 2024. Clinical data including pathological types, surgical procedures, intraoperative parameters, postoperative complications and their management were collected and analyzed. The inclusion criteria were central or unilateral anterior mediastinal tumors with a diameter less than 1/3 of the thoracic cavity and clear boundaries with major mediastinal blood vessels on imaging. Patients with pectus excavatum, giant tumors, or tumor invasion of major blood vessels were excluded.\u003c/p\u003e\u003ch2\u003eResults\u003c/h2\u003e \u003cp\u003eAll 4 patients were male, aged 9 to 12 years. The pathological diagnoses included thymoma, mature cystic teratoma, and residual mediastinal mass after chemotherapy for T-lymphoblastic lymphoma. All surgical procedures were successfully completed via subxiphoid thoracoscopy without conversion to open thoracotomy. The median intraoperative blood loss was less than 20 mL, and no allogeneic blood transfusion was required in any patient. The median postoperative hospital stay was 7 days (range, 6\u0026ndash;8 days). Mild postoperative complications (Clavien-Dindo grade Ⅰ) occurred in 2 patients (50%), including atelectasis and pleural effusion, all of which were completely resolved by conservative treatment or thoracostomy tube drainage without adverse effects on short-term prognosis. All tumors were resected with R0 margins, and pathological examination confirmed no residual tumor cells at the surgical margins.\u003c/p\u003e\u003ch2\u003eConclusion\u003c/h2\u003e \u003cp\u003eSubxiphoid thoracoscopic resection is a feasible and safe minimally invasive approach for selected pediatric patients with anterior mediastinal tumors, with the advantages of mild postoperative pain, no severe perioperative complications and satisfactory short-term outcomes. However, the narrow operative space caused by the small thoracic cavity in children increases the surgical difficulty of this technique. The development of pediatric-specific auxiliary surgical instruments and the accumulation of more clinical cases are required to verify its long-term safety and efficacy.\u003c/p\u003e","manuscriptTitle":"Subxiphoid Thoracoscopic Resection of Anterior Mediastinal Tumors in Children: Preliminary Clinical Experience","msid":"","msnumber":"","nonDraftVersions":[{"code":1,"date":"2026-04-03 11:18:27","doi":"10.21203/rs.3.rs-9010676/v1","editorialEvents":[{"type":"communityComments","content":0},{"type":"decision","content":"Revision requested","date":"2026-04-06T07:45:29+00:00","index":"","fulltext":""},{"type":"editorInvitedReview","content":"","date":"2026-03-30T19:28:33+00:00","index":"hide","fulltext":""},{"type":"reviewerAgreed","content":"91642237803654362036144220893442605009","date":"2026-03-30T19:22:16+00:00","index":"hide","fulltext":""},{"type":"editorInvitedReview","content":"","date":"2026-03-30T10:53:11+00:00","index":"hide","fulltext":""},{"type":"reviewerAgreed","content":"244184168838394422969449893246620249005","date":"2026-03-30T07:28:10+00:00","index":"hide","fulltext":""},{"type":"reviewerAgreed","content":"12828255873735674260959737501472984156","date":"2026-03-29T00:38:29+00:00","index":"hide","fulltext":""},{"type":"reviewerAgreed","content":"139315623881540809767256271456417635254","date":"2026-03-28T22:15:47+00:00","index":"hide","fulltext":""},{"type":"reviewerAgreed","content":"291874141688886679918385887039803281661","date":"2026-03-28T16:42:59+00:00","index":"hide","fulltext":""},{"type":"reviewersInvited","content":"","date":"2026-03-28T16:06:28+00:00","index":"","fulltext":""},{"type":"editorAssigned","content":"","date":"2026-03-10T06:07:24+00:00","index":"","fulltext":""},{"type":"checksComplete","content":"","date":"2026-03-10T06:07:19+00:00","index":"","fulltext":""},{"type":"submitted","content":"Journal of Cardiothoracic Surgery","date":"2026-03-02T13:09:27+00:00","index":"","fulltext":""}],"status":"published","journal":{"display":true,"email":"[email protected]","identity":"journal-of-cardiothoracic-surgery","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":false,"externalIdentity":"jcts","sideBox":"Learn more about [Journal of Cardiothoracic Surgery](http://cardiothoracicsurgery.biomedcentral.com)","snPcode":"13019","submissionUrl":"https://submission.nature.com/new-submission/13019/3","title":"Journal of Cardiothoracic Surgery","twitterHandle":"@BioMedCentral","acdcEnabled":true,"dfaEnabled":true,"editorialSystem":"em","reportingPortfolio":"BMC/SO AJ","inReviewEnabled":true,"inReviewRevisionsEnabled":true}}],"origin":"","ownerIdentity":"d75384ae-4201-40b6-a947-74d8fe872f27","owner":[],"postedDate":"April 3rd, 2026","published":true,"recentEditorialEvents":[],"rejectedJournal":[],"revision":"","amendment":"","status":"under-review","subjectAreas":[],"tags":[],"updatedAt":"2026-04-16T14:55:57+00:00","versionOfRecord":[],"versionCreatedAt":"2026-04-03 11:18:27","video":"","vorDoi":"","vorDoiUrl":"","workflowStages":[]},"version":"v1","identity":"rs-9010676","journalConfig":"researchsquare"},"__N_SSP":true},"page":"/article/[identity]/[[...version]]","query":{"redirect":"/article/rs-9010676","identity":"rs-9010676","version":["v1"]},"buildId":"XKTyCvWXoU3ODBz1xrDgd","isFallback":false,"isExperimentalCompile":false,"dynamicIds":[84888],"gssp":true,"scriptLoader":[]}