Objective Early presentation and prompt diagnosis of acute appendicitis are necessary to prevent progression of disease leading to complicated appendicitis. We hypothesize that patients had a delayed presentation of acute appendicitis during the COVID-19 pandemic, which affected severity of disease on presentation and outcomes. Patients and methods We conducted a retrospective review of all patients who were treated for acute appendicitis at Morgan Stanley Children's Hospital (MSCH) between March 1, 2020 and May 31, 2020 when the COVID-19 pandemic was at its peak in New York City (NYC). For comparison, we reviewed patients treated from March 1, 2019 to May 31, 2019, prior to the pandemic. Demographics and baseline patient characteristics were analyzed for potential confounding variables. Outcomes were collected and grouped into those quantifying severity of illness on presentation to our ED, type of treatment, and associated post-treatment outcomes. Fisher's Exact Test and Kruskal-Wallis Test were used for univariate analysis while cox regression with calculation of hazard ratios was used for multivariate analysis. Results A total of 89 patients were included in this study, 41 patients were treated for appendicitis from March 1 to May 31 of 2019 (non-pandemic) and 48 were treated during the same time period in 2020 (pandemic). Duration of symptoms prior to presentation to the ED was significantly longer in patients treated in 2020, with a median of 2 days compared to 1 day (p = 0.003). Additionally, these patients were more likely to present with reported fever (52.1% vs 24.4%, p = 0.009) and had a higher heart rate on presentation with a median of 101 beats per minute (bpm) compared to 91 bpm (p = 0.040). Findings of complicated appendicitis on radiographic imaging including suspicion of perforation (41.7% vs 9.8%, p < 0.001) and intra-abdominal abscess (27.1% vs 7.3%, p = 0.025) were higher in patients presenting in 2020. Patients treated during the pandemic had higher rates of non-operative treatment (25.0% vs 7.3%, p = 0.044) requiring increased antibiotic use and image-guided percutaneous drain placement. They also had longer hospital length of stay by a median of 1 day (p = 0.001) and longer duration until symptom resolution by a median of 1 day (p = 0.004). Type of treatment was not a predictor of LOS (HR = 0.565, 95% CI = 0.357–0.894, p = 0.015) or duration until symptom resolution (HR = 0.630, 95% CI = 0.405–0.979, p = 0.040). Conclusion Patients treated for acute appendicitis at our children's hospital during the peak of the COVID-19 pandemic presented with more severe disease and experienced suboptimal outcomes compared to those who presented during the same time period in 2019. Level of Evidence III

A method that allows the specific cloning of DNA fragments absent from patients homozygous or hemizygous for chromosomal deletions is described. The method involves phenol-accelerated competitive DNA reassociation and subsequent molecular cloning of appropriately reassociated molecules. The deletion DNA sample utilized in the competition was isolated from a patient with a minute interstitial deletion in the short arm of the X chromosome. Sheared DNA isolated from a male child, who was diagnosed as having Duchenne muscular dystrophy, chronic granulomatous disease, and retinitis pigmentosa, was combined in a 200-fold excess with Mbo I-cleaved DNA isolated from a 49,XXXXY human lymphoid cell line, and the mixture was subjected to a phenol-enhanced reassociation technique. Analysis of 81 unique segments derived from cloned reassociated DNA molecules has led to the identification of 4 (5%) human DNA fragments that are absent from the male patient's DNA. The 4 clones were localized, on the basis of hybridization with restriction nuclease-digested genomic DNA from a panel of human and human-rodent hybrid cell lines, into three regions surrounding band 21 of the short arm of the normal human X chromosome. These clones are potential linkage markers for the diseases affecting this boy. Each clone, as well as others obtainable by this approach, may also serve as a starting point in the eventual cloning of these three X-linked-disease loci. Extension of this approach to other loci, including human tumors potentially homozygous for small deletions, should also be possible.

Purpose Extracorporeal Life Support Organization Registry data confirm that the number of pediatric patients being supported by extracorporeal membrane oxygenation (ECMO) is increasing. To minimize the potential neurologic effects of carotid artery ligation, the common femoral artery (CFA) is frequently being used for arterial cannulation. The cannula has the potential for obstructing flow to the lower limb, thus increasing ischemia and possible limb loss. We present a single institution’s experience with CFA cannulation for venoarterial (VA) ECMO and ask whether any precannulation variables correlate with the development of significant limb ischemia. Methods We reviewed all pediatric patients who were supported by VA ECMO via CFA cannulation from January 2000 to February 2010. Limb ischemia was the primary variable. The ischemia group was defined as the patients requiring an intervention because of the development of lower extremity ischemia. The patients in the no-ischemia group did not develop significant ischemia. Continuous variables were reported as medians with interquartile ranges and compared using Mann-Whitney U tests. Differences in categorical variables were assessed using χ2 testing (Fisher’s Exact). Statistical significance was assumed at P < .05. Results Twenty-one patients (age, 2–22 years) were cannulated via the CFA for VA ECMO. Significant ischemia requiring intervention (ischemia group) occurred in 11 (52%) of 21. In comparing the 2 groups (ischemia vs no ischemia), no clinical variables predicted the development of ischemia (Table 1). In the ischemia group, 9 (81%) of 11 had a distal perfusion catheter (DPC) placed. Complications of DPC placement included one case of compartment syndrome requiring a fasciotomy and one patient requiring interval toe amputation. Of the 2 patients in the ischemia group who did not have a DPC placed, 1 required a vascular reconstruction of an injured superficial femoral artery and 1 underwent a below-the-knee amputation. Mortality was lower in the ischemia group (27% vs 60%). Conclusions Limb ischemia remains a significant problem, as more than half of our patients developed it. The true incidence may not be known as a 60% mortality in the no-ischemia group could mask subsequent ischemia. Although children are at risk for developing limb ischemia/loss, no variable was predictive of the development of significant limb ischemia in our series. Because of the inability to predict who will develop limb ischemia, early routine placement of a DPC at the time of cannulation may be warranted. However, DPCs do not completely resolve issues around tissue loss and morbidity. Prevention of limb ischemia/loss because of CFA cannulation for VA ECMO continues to be a problem that could benefit from new strategies.