The impact of margins and re-resection in pediatric synovial sarcoma.

INTRODUCTION: Synovial sarcoma is one of the most common soft tissue sarcomas in children. Guidelines regarding the adequate extent of resection margins and the role of re-resection are lacking. We sought to evaluate the adequate resection margin and the role of re-resection in predicting outcomes in children with synovial sarcomas. METHODS: A cohort of 36 patients less than 18 years of age at diagnosis who were treated for localized synovial sarcoma at three tertiary pediatric hospitals between January 2004 and December 2020 were included in this study. Patient and tumor demographics, treatment information, and margin status after surgical resection were collected from the medical record. Clinical, treatment, and surgical characteristics, as well as outcomes including hazard ratios (HRs), event-free survival (EFS), and overall survival (OS) were compared by resection margins group and re-resection status. RESULTS: Patients in the R1 resection group were significantly more likely to relapse or die compared to patients in the R0 resection group. However, there was no significant difference in EFS (HR 0.52, p = 0.54) or OS (HR 1.56, p = 0.719) in R0 patients with less than 5 mm margins compared to R0 patients with more than 5 mm margins. Patients with R1 on initial or re-resection had significantly worse OS than patients who had R0 resection on initial or re-resection (HR = 10.12, p = 0.005). CONCLUSION: This study re-affirms that R0 resection is an independent prognostic predictor of better OS/EFS in pediatric synovial sarcoma. Second, our study extends this finding to report negative margins on initial resection or re-resection is associated with better OS/EFS than positive margins on initial resection or re-resection. Lastly, we found that there is no difference in outcomes associated with re-resection or <5 mm margins for R0 patients, indicating that re-resection and <5 mm margins are acceptable if microscopic disease is removed.

Acute Compartment Syndrome in Pediatric Patients on Extracorporeal Membrane Oxygenation Support.

BACKGROUND: When acute compartment syndrome (ACS) occurs in pediatric patients requiring venoarterial extracorporeal membrane oxygen (VA ECMO) support, there is little data to guide surgeons on appropriate management. The purpose of this study is to characterize the presentation, diagnosis, timeline, and outcomes of patients who developed this complication. METHODS: This is a single-center retrospective case series of children below 19 years old on VA ECMO support who subsequently developed extremity ACS between January 2016 and December 2022. Outcomes included fasciotomy findings, amputation, mortality, and documented function at the last follow-up. RESULTS: Of 343 patients on VA ECMO support, 18 (5.2%) were diagnosed with ACS a median 29 hours after starting ECMO. Initial cannulation sites included 8 femoral, 6 neck, and 4 central. Femoral artery cannulation was associated with an increased risk of ACS [odds ratio=6.0 (CI: 2.2 to 15), P <0.0001]. In the hospital, the mortality rate was 56% (10/18). Fourteen (78%) patients received fasciotomies a median of 1.2 hours after ACS diagnosis. Only 4 (29%) patients had all healthy muscles at initial fasciotomy, while 9 (64%) had poor muscular findings in at least 1 compartment. Patients with worse findings at fasciotomy had a significantly longer duration between ischemia onset and ACS diagnosis. Patients required a median of 1.5 additional procedures after fasciotomy, and only 1 (7%) developed a surgical site infection. Of the 7 surviving fasciotomy patients, 2 required amputations, 3 developed an equinus contracture, 1 developed foot drop, and 3 had no ACS-related deficits. Four patients did not receive fasciotomies: 3 were deemed too ill and later died, and 1 was diagnosed too late to benefit. The only surviving nonfasciotomy patient required bilateral amputations. CONCLUSIONS: Pediatric ECMO-associated ACS is not exclusive to patients with femoral artery cannulation. The majority of fasciotomy patients were diagnosed with ACS after muscle necrosis had already started. We were unable to definitively conclude whether fasciotomies provide better outcomes. There is a need for increased awareness and earlier recognition of this rare yet potentially devastating complication. LEVEL OF EVIDENCE: Level IV-retrospective case series.

Pediatric Septic Arthritis.

Acute septic arthritis is a condition with the potential for joint destruction, physeal damage, and osteonecrosis, which warrants urgent identification and treatment. The organism most frequently responsible is Staphylococcus aureus; however, our understanding of pathogens continues to evolve as detection methods continue to improve. MRI has improved our ability to detect concurrent infections and is a useful clinical tool where available. The treatment course involves intravenous antibiotics followed by transition to oral antibiotics when clinically appropriate. The recommended surgical treatment of septic arthritis is open arthrotomy with decompression of the joint, irrigation, and debridement and treatment of concurrent infections.

Pediatric osteoarticular infection update.

Musculoskeletal infections are a common cause of morbidity in children. A multitude of studies over the past few years have improved our knowledge and understanding of the etiology, diagnosis, and treatment of pediatric osteomyelitis and septic arthritis. Staphylococcus aureus continues to be the most common pathogen; however, new and innovative organism identification techniques are improving the speed and accuracy of diagnosis and increasing the identification of other less common organisms. Improved capability for patient assessment with a combination of advanced imaging studies and timely laboratory tests allow for a more thorough understanding of the disease process and more efficient patient care.