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Vascularization remains a substantial limitation to the viability of engineered tissue. By comparing in vivo vascularization dynamics of a self-assembled prevascular endothelial–fibroblast model to avascular grafts, we explore the vascularization rate limitations in implants at early time intervals, during which tissue hypoxia begins to affect cell viability. Scaffold-free prevascular endothelial–fibroblast constructs (SPECs) may serve as a modular and reshapable vascular bed in replacement tissues. SPECs, fibroblast-only spheroids (FOS), and silicone implants were implanted in 54 Sprague Dawley rats and harvested at 6, 12, and 24 h (n = 5 per time point and implant type). We hypothesized that the primary endothelial networks of the SPECs allow earlier anastomosis and increased vessel formation in the interior of the implant compared to FOS and silicone implants within a 24 h window. All constructs were encapsulated by an endothelial lining at 6 h postimplantation and SPEC internal cords inosculated with the host vascular network by this time point. SPECs had a significantly higher microvascular area fraction and branch/junction density of penetrating cords at 6–12 h compared with other constructs. In addition, SPECs demonstrated perivascular cell recruitment, lumen formation, and network remodeling consistent with vessel maturation at 12–24 h; however, these implants were poorly perfused within our observation window, suggesting poor lumen patency. FOS vascular characteristics (microvessel area and penetrating cord density) increased within the 12–24 h period to represent those of the SPEC implants, suggesting a 12 h latency in host response to avascular grafts compared to prevascular grafts. Knowledge of this temporal advantage in in vitro prevascular network self-assembly as well as an understanding of the current limitations of SPEC engraftment builds on our theoretical temporal model of tissue graft vascularization and suggests a crucial time window, during which technological improvements and vascular therapy can improve engineered tissue survival.

Background: The radial artery is commonly accessed for arterial blood sampling, invasive blood pressure monitoring, and vascular access for cardiac catheterization. Iatrogenic radial artery injury is a rare complication with potentially devastating outcomes. The purpose of our study was to identify the timing of these injuries and define a treatment algorithm. Methods: A retrospective chart review of all patients with iatrogenic radial artery injuries were identified between the years 2008 and 2018. Patient demographics, mechanism of injury, interventions, and outcomes were recorded. Results: A total of 18 patients were identified with iatrogenic radial artery injury over a 10-year period. Fifty percent of these resulted from arterial line cannulation, and 50% occurred after transradial cardiac catheterization. Thirty-three percent resulted in radial artery pseudoaneurysm (RAP), and 66% had acute radial artery thrombosis (RAT). Eleven of the 18 patients underwent operative intervention. Of the 12 patients with RAT, 4 were treated with systemic anticoagulation for 3 months. All patients with RAP who were surgically treated had resolution of symptoms on follow-up evaluation. Of the patients with RAT, 2 had persistent sensorimotor deficits after treatment, and 1 patient had multiple necrotic fingers requiring amputation. Conclusion: Radial artery injuries are an uncommon but potentially devastating complication of common invasive procedures resulting in thrombosis, pseudoaneurysm, or overt hand ischemia. The treatment options vary depending on presenting symptoms.

Pediatric intra-abdominal injuries (IAI) from blunt abdominal trauma (BAT) rarely require emergent intervention. For those children undergoing procedural intervention, our aim was to understand the timing and indications for operation and angiographic embolization.We prospectively enrolled children younger than 16 years after BAT at 14 Level I Pediatric Trauma Centers over a 1-year period. Patients with IAI who received an intervention (IAI-I) were compared with those who did not receive an intervention using descriptive statistics and univariate analysis; p less than 0.05 was considered significant.Two hundred sixty-one (11.9%) of 2,188 patients had IAI. Forty-five (17.2%) IAI patients received an acute procedural intervention (38 operations, seven angiographic embolization). The mean age for patients requiring intervention was 7.1 ± 4.1 years and not different from the population. Most patients (88.9%) with IAI-I were normotensive. IAI-I patients were significantly more likely to have a mechanism of motor vehicle collision (66.7% vs. 38.9%), more likely to present as a Level I activation (44.4% vs. 26.9%), more likely to have a Glascow Coma Scale less than 14 (31.1% vs. 15.5%), and more likely to have an abnormal abdominal physical examination (93.3% vs. 65.7%) than patients that did not require acute intervention. All patients underwent computed tomography scan before intervention. Operations consisted of laparotomy (n = 21), laparoscopy converted to open (n = 11), and laparoscopy alone (n = 6). The most common surgical indications were hollow viscus injury (HVI) (11 small bowel, 10 colon, 6 small bowel/colon, 2 duodenum). All interventions for solid organ injury, including seven angioembolic procedures, occurred within 8 hours of arrival; many had hypotension and received a transfusion. Procedural interventions were more common for HVI than for solid organ injury (59.2% vs. 7.6%). Postoperative mortality from IAI was 2.6%.Acute procedural interventions for children with IAI from BAT are rare, predominantly for HVI, are performed early in the hospital course and have excellent clinical outcomes.Prognostic/epidemiologic study, level III; therapeutic study, level IV.

Supplemental Digital Content is available in the text., Introduction: Consistent delivery of high-quality care is a marker of health-care system reliability. Although clinically abstracted outcome databases have revolutionized surgical quality improvement efforts for many high-volume procedures, their utility in aiding the improvement of time-sensitive processes is less clear. The purpose of this study was to determine whether process measures surrounding the delivery of timely surgical care could delineate the variability in the outcome of patients with testicular torsion. Our secondary aim was to use the data to drive quality improvement efforts locally. Methods: We performed a retrospective review of encounters for testicular torsion in patients less than 18 years. Characteristics of patients undergoing detorsion/orchiopexy and orchiectomy were compared. We evaluated orchiectomy as a function of age, insurance status, time of presentation, duration of symptoms, time to ultrasound, and time to surgery. Results: Over 10 years, we identified 46 patients, of whom 21 met inclusion criteria. Twelve patients (57.1%) underwent detorsion/orchiopexy, whereas 9 patients underwent orchiectomy. After-hours presentation and age were not predictive of orchiectomy, whereas the duration of symptoms was predictive of orchiectomy. Differences in time to surgery for orchiopexy and orchiectomy groups approached but did not reach significance (P = 0.07). Conclusions: Significant variability persists in the timely delivery of comprehensive and coordinated care for children suffering from time-sensitive surgical conditions. Pediatric surgical programs would realize significant benefit from a surgical quality improvement program that incorporates validated process metrics, along with outcome measures, to help drive efficiencies and integrate care more effectively.

A clinical prediction rule was previously developed by the Pediatric Surgery Research Collaborative (PedSRC) to identify patients at very low risk for intra-abdominal injury (IAI) and intra-abdominal injury receiving an acute intervention (IAI-I) who could safely avoid abdominal computed tomography (CT) scans after blunt abdominal trauma (BAT). Our objective was to externally validate the rule.The public-use dataset was obtained from the Pediatric Emergency Care Applied Research Network (PECARN) Intra-abdominal Injury Study. Patients 16 years of age and younger with chest x-ray, completed abdominal history and physical examination, aspartate aminotransferase (AST), and amylase or lipase collected within 6 hours of arrival were included. We excluded patients who presented greater than 6 hours after injury or missing any of the five clinical prediction variables from the PedSRC prediction rule.We included 2,435 patients from the PECARN dataset, with a mean age of 9.4 years. There were 235 patients with IAI (9.7%) and 60 patients with IAI-I (2.5%). The clinical prediction rule had a sensitivity of 97.5% for IAI and 100% for IAI-I. In patients with no abnormality in any of the five prediction rule variables, the rule had a negative predictive value of 99.3% for IAI and 100.0% for IAI-I. Of the "very low-risk" patients identified by the rule, 46.8% underwent abdominal CT imaging.A highly sensitive clinical prediction rule using history and abdominal physical examination, laboratory values, and chest x-ray was successfully validated using a large public-access dataset of pediatric BAT patients.Epidemiologic/prognostic study, level III; therapeutic care/management study, level IV.

Kidney transplantation is now a mainstream therapy for end-stage renal disease. However, with approximately 96,000 people on the waiting list and only one-fourth of these patients achieving transplantation, there is a dire need for alternatives for those with failing organs. In order to decrease the harmful consequences of dialysis along with the overall healthcare costs it incurs, active investigation is ongoing in search of alternative solutions to organ transplantation. Implantable tissue-engineered renal cellular constructs are one such feasible approach to replacing lost renal functionality. Here, described for the first time, is the microdissection of murine kidneys for isolation of living corticomedullary renal segments. These segments are capable of rapid incorporation within scaffold-free endothelial-fibroblast constructs which may enable rapid connection with host vasculature once implanted. Adult mouse kidneys were procured from living donors, followed by stereoscope microdissection to obtain renal segments 200 - 300 µm in diameter. Multiple renal constructs were fabricated using primary renal segments harvested from only one kidney. This method demonstrates a procedure which could salvage functional renal tissue from organs that would otherwise be discarded.

For infants with necrotizing enterocolitis (NEC) treated nonoperatively, no consensus exists on the optimal fasting period prior to reintroducing feeds after NEC. We report our experience with early (7days) and late (≥7days) refeeding in this population.A chart review of infants with NEC born between 2006 and 2016 was performed. Data elements include demographics, comorbidities, day of diagnosis, Bell's stage, recurrence, strictures, length of stay and mortality, and were grouped into early and late refeeding. T-tests were used for means and chi-squared tests for distribution of proportions. Linear and logistic regressions were used to further evaluate the association of length of stay, stricture, recurrence, and death with time to refeeding.Of 228 NEC patients, 149(65%) were treated nonoperatively (Bell Stages I, IIA, IIB, IIIA). Eleven patients were excluded owing to never restarting feeds, largely secondary to early death. The early (n=40) and late refeeding (n=98) groups were not significantly different with regard to mean gestational age at birth, race, birth weight, day of life at NEC diagnosis, or cardiac disease. NEC Stage was significantly different (p0.001). The late group had significantly more Stage IIB patients (p=.02), and the early group had more stage I patients (p=0.01). After adjusting for Bell's stage, the odds of NEC recurrence, death, and the composite outcome of recurrence or stricture or death were not significantly different between early and late groups.No standardized guidelines exist for restarting enteral nutrition following medical NEC. In patients managed nonoperatively, early reintroduction of feeding was not significantly associated with increased NEC recurrence, mortality, or stricture.Treatment Study - Level III.

Fibrosing mediastinitis is a condition in which mediastinal fat is replaced by fibrous tissue. Complications may arise due to progressive fibrotic infiltration and compression of major vascular, respiratory, and nervous structures within the mediastinum. We describe 3 similar cases of fibrosing mediastinitis with pulmonary vessel involvement. Imaging and intraoperative observation revealed involvement of the pulmonary vasculature in all 3 patients. Perfusion studies showed decreased or absent perfusion to one or both of the lungs. All patients tested negative for histoplasmosis, 2 required lung resection, with the 3rd forgoing surgery.