William Middlesworth

Ultrasonography/mri versus ct for diagnosing appendicitis

BACKGROUND: Cross-sectional imaging increases accuracy in diagnosing appendicitis. We hypothesized that a radiation-free imaging pathway of ultrasonography selectively followed by MRI would not change clinical end points compared with computed tomography (CT) for diagnosis of acute appendicitis in children. METHODS: We retrospectively reviewed children (<18 years old) who had diagnostic imaging for suspected acute appendicitis between November 2008 and October 2012. Before November 2010 CT was used as the primary imaging modality (group A); subsequently, ultrasonography was the primary imaging modality followed by MRI for equivocal findings (group B). Data collected included time from triage to imaging and treatment and results of imaging and pathology. RESULTS: Six hundred sixty-two patients had imaging for suspected appendicitis (group A = 265; group B = 397, of which 136 [51%] and 161 [41%], respectively, had positive imaging for appendicitis). Negative appendectomy rate was 2.5% for group A and 1.4% for group B. Perforation rate was similar for both groups. Time from triage to antibiotic administration and operation did not differ between groups A and B. There was higher proportion of positive imaging and appendectomies in group A and thus more negative imaging tests in group B (ultrasonography and MRI), but diagnostic accuracy of the 2 imaging pathways was similar. CONCLUSIONS: In children with suspected acute appendicitis, a radiation-free diagnostic imaging of ultrasonography selectively followed by MRI is feasible and comparable to CT, with no difference in time to antibiotic administration, time to appendectomy, negative appendectomy rate, perforation rate, or length of stay.

Limb ischemia after common femoral artery cannulation for venoarterial extracorporeal membrane oxygenation: an unresolved problem

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 institutions 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 (Fishers 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.

Thoracoscopic Lobectomy in Infants Less Than 10 kg with Prenatally Diagnosed Cystic Lung Disease

PURPOSE Thoracoscopic lobectomy for congenital cystic lung lesions is an accepted technique in pediatric surgery. Since an increasing number of these lesions are detected prenatally, the safety and efficacy of infant resections have been questioned. We reviewed our experience over a 10-year period to evaluate early resection of these lesions. METHODS From January 2001 to August 2009, 75 patients under 1 year of age and weighing <10 kg underwent thoracoscopic lobectomy at two institutions. Patients carried the following diagnoses: 52 had congenital cystic adenomatoid malformation, 20 had bronchopulmonary sequestration, and 3 had congenital lobar emphysema. All lesions were confirmed after birth by computed tomography scan. Patient age at operation ranged from 4 days to 11 months and patient weight from 3.1 to 10 kg. RESULTS Seventy-four of 75 lobectomies were thoracoscopically completed. There were 16 upper lobectomies, 1 middle lobectomy, and 55 lower lobectomies. Operative time ranged from 45 to 225 minutes. Hospital length of stay ranged from 1 to 5 days. A subset of 26 patients had surgery younger than 3 months of age and <5 kg, despite being asymptomatic. Their operative time averaged 90 minutes, and mean length of hospital stay was 1.5 days. CONCLUSION Thoracoscopic lobectomy is safe for infants <10 kg and avoids the morbidity associated with thoracotomy. Operating early on younger patients may avoid the inflammatory changes associated with both clinically apparent and subclinical infections, even in patients weighing <5 kg. This may make the procedures less technically challenging and may result in lower complication and conversion rates.

Construction of a human X-chromosome-enriched phage library which facilitates analysis of specific loci

A human X-chromosome-enriched MboI-partial-digest recombinant library in phage lambda Charon30 has been constructed. Twelve out of the thirteen X-chromosome DNA sequences that were tested were present in the library. Most regions were covered in overlapping phage inserts; mean insert size was 13.7 kb. One phage from the library allowed detection of a 225-bp insertion of DNA into a region near the Duchenne muscular dystrophy (DMD) locus. Another recombinant phage represents an expansion of a region which exhibits extensive and varying homology with other human chromosomes, including the Y, as well as with rodent DNA. The present library should have widespread use for examining DNA sequences on the human X chromosome.

Percutaneous distal perfusion of the lower extremity after femoral cannulation for venoarterial extracorporeal membrane oxygenation in a small child.

Femoral cannulation in pediatric patients requiring extracorporeal membrane oxygenation (ECMO) is commonly associated with distal limb ischemia. Authors have previously reported successful lower limb perfusion using various open techniques to cannulate a distal lower extremity artery at the time of initial ECMO cannulation. These procedures include open femoral artery antegrade cannulation and distal posterior tibial artery retrograde cannulation in older children and adults. Such approaches require ample vessel diameters to accommodate an arteriotomy and catheter insertion and, therefore, are of limited use in smaller children. We hypothesized that after femoral artery cannulation for ECMO, a percutaneous technique of distal limb perfusion might offer unique advantages when treating lower extremity ischemia in small pediatric patients. We report a technique for percutaneous antegrade cannulation in a 4-year-old patient shortly after her primary cannulation for venoarterial ECMO via the femoral artery.

Independent case reportPercutaneous distal perfusion of the lower extremity after femoral cannulation for venoarterial extracorporeal membrane oxygenation in a small child

Femoral cannulation in pediatric patients requiring extracorporeal membrane oxygenation (ECMO) is commonly associated with distal limb ischemia. Authors have previously reported successful lower limb perfusion using various open techniques to cannulate a distal lower extremity artery at the time of initial ECMO cannulation. These procedures include open femoral artery antegrade cannulation and distal posterior tibial artery retrograde cannulation in older children and adults. Such approaches require ample vessel diameters to accommodate an arteriotomy and catheter insertion and, therefore, are of limited use in smaller children. We hypothesized that after femoral artery cannulation for ECMO, a percutaneous technique of distal limb perfusion might offer unique advantages when treating lower extremity ischemia in small pediatric patients. We report a technique for percutaneous antegrade cannulation in a 4-year-old patient shortly after her primary cannulation for venoarterial ECMO via the femoral artery.

Laparoscopic Excision of Choledochal Cysts with Total Intracorporeal Reconstruction

PURPOSE There are numerous published reports of laparoscopic resection of choledochal cysts (CDCs), but almost all involve extracorporeal reconstruction of a biliary drainage system. We describe and evaluate the technique of laparoscopic CDC resection with total intracorporeal reconstruction. METHODS We reviewed all patients who underwent a laparoscopic CDC resection from March 2005 to January 2010 at Rocky Mountain Childrens Hospital and Childrens Hospital of New York-Presbyterian. We obtained data on operative time, characteristics of reconstruction, time to initiation of diet, length of stay, complications, and outcome. RESULTS Thirteen patients (median age 5 years, range 1-16) underwent a laparoscopic CDC excision with total intracorporeal reconstruction. Four ports were used in all cases and no patients required conversion to an open procedure. Operative time ranged from 130 to 325 minutes (median 240 minutes). Median time to initiation of diet was 1 day (range 1-4 days). Median length of stay was 5 days (range 4-8 days). There were no cases of cholangitis; however, 1 patient developed a small bowel obstruction requiring re-operation. CONCLUSION Laparoscopic resection of CDCs with total intracorporeal reconstruction is a safe and effective technique. The minimal handling of the bowel appears to minimize postoperative ileus, allows for early postoperative feeding and discharge.

Fulminant pH1N1-09 influenza-associated myocarditis in pediatric patients.

Objective: To report an atypical presentation of pH1N1-09 influenza infection in children as fulminant myocarditis and tamponade and the successful treatment with extracorporeal membrane oxygenation. Design: Case report. Setting: Pediatric cardiac intensive care unit in a quarternary care childrens hospital. Patients: Two girls, 5 and 7 yrs of age, infected with pH1N1-09 influenza virus who presented in cardiogenic shock with a pericardial effusion and echocardiographic evidence of tamponade from fulminant myocarditis. Interventions: Both patients received a pericardiocentesis. One was managed with multiple, high-dose inotropic agents, whereas the other required institution of extracorporeal membrane oxygenation. Measurements and Main Results: Acute respiratory distress syndrome is the major reported clinical manifestation of pH1N1-09 influenza virus infection in hospitalized pediatric patients. In this report we describe two children with confirmed pH1N1-09 influenza infection that required intensive care for fulminant myocarditis. Neither patient had the typical symptoms of influenza-like illness, respiratory compromise, or evidence of pulmonary involvement. One child required extracorporeal membrane oxygenation. Both children survived to hospital discharge. Conclusions: pH1N1-09 influenza infection can cause fulminant myocarditis in the healthy pediatric population. The clinical presentation may be nonspecific, and the lack of pulmonary symptoms may make diagnosis difficult. Extracorporeal membrane oxygenation support may offer an effective bridge to the recovery of heart function.

The use of recombinant tissue-type plasminogen activator in a newborn with an intracardiac thrombus developed during extracorporeal membrane oxygenation

Extracorporeal membrane oxygenation (ECMO) support is often used to support infants and children with hemodynamic or respiratory failure. One of the major obstacles of safely treating a child with ECMO is balancing the risk of hemorrhage with the potential for thrombus development. Managing thrombosis in the setting of ECMO is challenging and has no defined algorithm. The use of recombinant tissue-type plasminogen activator (tPA) for thrombolysis has been previously described in cases where thrombi have developed despite adequate anticoagulation. In such situations, the risk of hemorrhage must be carefully balanced with the benefit of dissolving the clot and reestablishing flow. We present a case of an infant who required ECMO because of severe primary pulmonary hypertension and subsequently developed a right atrial thrombus adjacent to the ECMO cannula. The patient was treated with tPA with immediate improvement but had fatal intracranial hemorrhage almost 3 days after the tPA was administered. In this report, we review the current literature on tPA use during ECMO support and suggest a rational approach.

Thoracoscopic lobectomy for severe bronchiectasis in children.

BACKGROUND/PURPOSE Lung resection should be considered for severe, localized bronchiectasis causing recurrent infections in patients with cystic fibrosis (CF) and other diseases. This series represents our experience and results with thoracoscopic lobectomy for the treatment of severe bronchiectasis confined to a single lobe. METHODS Nineteen thoracoscopic anatomic lobectomies were performed between July 1994 and August 2008. Patient age at the time of surgery ranged from 14 months to 22 years. Left lower lobectomy was the most frequently performed procedure (n = 9). Eight patients suffered from CF, 5 had chronic pneumonia, 2 had chronic aspiration, and 3 had other diagnoses. RESULTS Mean operative time was 162 minutes (range, 65-300), and no cases required a conversion to thoracotomy. The mean duration of postoperative chest tube drainage was 3.2 days (range, 1-9). The mean postoperative length of stay was 3.6 days (range, 1-12). One patient had a prolonged air leak lasting 9 days, which resolved with the placement of a second chest tube. Another had a small hydropneumothorax, which persisted after chest tube removal but resolved spontaneously. CONCLUSIONS Thoracoscopic lobectomy for severe lobar bronchiectasis with recurrent infection is technically challenging, but appears to be safe and effective. Avoidance of a thoracotomy, in this group of patients, allows for earlier mobilization, less postoperative pain with cough and chest physiotherapy, and faster recovery. There appear to be significant benefits in these patients with chronic respiratory illnesses.