Experience With the Crescent• Right Atrial Jugular Dual Lumen Catheter for Pediatric Venovenous Extracorporeal Membrane Oxygenation: A Case Series.

The Crescent dual lumen right atrial (RA) cannula has recently been introduced for the support of pediatric patients in need of venovenous extracorporeal membrane oxygenation (VV ECMO) support. We present the first pediatric case series illustrating utility of the Crescent RA cannula in the pediatric patient population at a single institution over a 10 month period. From December 2021 to August 2022, six pediatric patients were adequately supported on seven VV ECMO runs at our institution with the Crescent RA cannula. ECMO cannulation, circuit design, anticoagulation management, ECMO circuit pressures, flow rates, and recirculation were similar to our standard of care for VV ECMO. The Crescent RA cannula can be used safely and effectively to provide adequate support for pediatric patients requiring VV ECMO.

A Systematic Review of Clinical Outcomes After Carotid Artery Ligation Versus Carotid Artery Reconstruction Following Venoarterial Extracorporeal Membrane Oxygenation in Infants and Children.

INTRODUCTION: In pediatric and neonatal populations, the carotid artery is commonly cannulated for venoarterial (VA) extracorporeal membrane oxygenation (ECMO). The decision to ligate (carotid artery ligation [CAL]) versus reconstruct (carotid artery reconstruction [CAR]) the artery at decannulation remains controversial as long-term neurologic outcomes remain unknown. The objective of this study was to summarize current literature on clinical outcomes following CAL and CAR after Venoarterial Extracorporeal Membrane Oxygenation (VA-ECMO). METHODS: PubMed (MEDLINE), Embase, Web of Science, and Cochrane databases were searched using keywords from January 1950 to October 2020. Studies examining clinical outcomes following CAL and CAR for VA-ECMO in patients <18 y of age were included. Prospective and retrospective cohort studies, case series, case-control studies, and case reports were included. The Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines were performed independently by two reviewers. Assessment of risk of bias was performed. RESULTS: Eighty studies were included and classified into four categories: noncomparative clinical outcomes after CAL (n = 23, 28.8%), noncomparative clinical outcomes after CAR (n = 12, 15.0%), comparative clinical outcomes after CAL and/or CAR (n = 28, 35.0%), and case reports of clinical outcomes after CAL and/or CAR (n = 17, 21.3%). Follow-up ranged from 0 to 11 y. CAR patency rates ranged from 44 to 100%. There was no substantial evidence supporting an association between CAL versus CAR and short-term neurologic outcomes. CONCLUSIONS: Studies evaluating outcomes after CAL versus CAR for VA-ECMO are heterogeneous with limited generalizability. Further studies are needed to evaluate long-term consequences of CAL versus CAR, especially as the first survivors of pediatric/neonatal ECMO approach an age of increased risk of carotid stenosis and stroke.

Recent Modifications of the Nuss Procedure: The Pursuit of Safety During the Minimally Invasive Repair of Pectus Excavatum.

OBJECTIVE: To review standardized Nuss correction of pectus excavatum and vacuum bell treatment over the last 10 years. SUMMARY OF BACKGROUND DATA: In 2010, we reported 21 years of the Nuss procedure in 1215 patients. METHODS: Over the last 10 years, 2008-2018, we evaluated 1885 pectus excavatum patients. Surgery was indicated for well-defined objective criteria. A consistent operation was performed by 8 surgeons in 1034 patients, median 15 years, (range 6-46); 996 were primary, and 38 redo operations. Surgical patients' mean computed tomography index was 5.46. Mitral valve prolapse was present in 5.4%, Marfan syndrome in 1.1% and scoliosis in 29%. Vacuum bell treatment was introduced for 218 patients who did not meet surgical criteria or were averse to surgery. RESULTS: At primary operation, 1 bar was placed in 49.8%; 2 bars, 49.4%; and 3 bars, 0.7%. There were no deaths. Cardiac perforation occurred in 1 patient who had undergone previous cardiac surgery. Paraplegia after epidural catheter occurred once. Reoperation for bar displacement occurred in 1.8%, hemothorax in 0.3%, and wound infection in 2.9%; 1.4% required surgical drainage. Allergy to stainless steel was identified in 13.7%. A good anatomic outcome was always achieved at bar removal. Recurrence requiring reoperation occurred in 3 primary surgical patients. Two patients developed carinate overcorrection requiring reoperation. Vacuum bell treatment produced better results in younger and less severe cases. CONCLUSIONS: A standardized Nuss procedure was performed by multiple surgeons in 1034 patients with good overall safety and results in primary repairs. Vacuum bell treatment is useful.

Selective use of sternal elevation before substernal dissection in more than 2000 Nuss repairs at a single institution.

BACKGROUND/PURPOSE: Evaluate the safety of sternal elevation (SE) used selectively before creating the substernal tunnel during the Nuss procedure. METHODS: An IRB-approved (01-05-EX-0175-HOSP), single institution, retrospective review was performed (1/1/1997-11/20/2017). Primary and secondary Nuss repairs (i.e., previous Nuss, Ravitch, thoracotomy, or sternotomy) are included. SE use, cardiac injuries, and pectus bar infections are reported. Chi square and Fisher's exact test (FE) were used (critical p < .05). RESULTS: 2037 patients [(80% male; mean age 15.2 years (SD = 4.4, range 3-46); mean Haller index (HI) 5.3 (SD = 5.7, range 1.73-201)] underwent Nuss repair. SE was used before creating the substernal tunnel in 171 (8.4%): 160 (8.2%) of 1949 primary and 11 (12.5%) of 88 secondary repairs. SE use increased significantly [χ2(2) = 118.93; p < .001] over time and with increasing HI [χ2(3) = 59.9; p < .001]. No cardiac injuries occurred in primary repairs but two occurred in patients with previous sternotomy. Infection rates were not different with (2.9%) or without SE (1.8%) [χ2(1) =1.14; p = .285] and not higher with off-label VB (1.5%) versus other SE techniques (3.8%) [FE, p = .65)]. CONCLUSION: Selective use of sternal elevation before substernal dissection during the Nuss procedure is safe but may not prevent cardiac injuries in patients with previous sternotomy. Infection rates were not increased with SE. TYPE OF STUDY: Retrospective review. LEVEL OF EVIDENCE: IV.

Development and validation of the Pectus Carinatum Body Image Quality of Life (PeCBI-QOL) questionnaire.

INTRODUCTION: While body image disturbances and quality of life in persons with pectus excavatum (PE) have been well documented, very little has been done to systematically measure and document the same in patients with pectus carinatum (PC). Because of this, the current study aimed to develop and validate an instrument to assess body image related quality of life in patients with PC and their parents. METHOD: Participants: Two waves of data collection took place. The development phase enrolled 78 PC patients and 76 matched parents. The validation phase enrolled 50 PC patients and 50 parents. Mean age at the initiation of treatment was 15.14 (SD = 2.54). Participants were mostly boys (85.9%) and White or Caucasian (89.7%). Instrument development, refinement, and validation: A group of 5 experts in chest wall deformities used existing measures of body image disturbances in PE, combined with the broader body image literature, to develop larger item pools for patients and their parents. Item analysis from this phase was used to remove poorly performing or statistically redundant items. In the validation phase, refined patient and parent instruments were examined using exploratory principal components factor analysis (EFA) with parallel analysis for factor retention, followed by Varimax rotation to identify a final factor solution. RESULTS/DISCUSSION: This development and refinement process yielded a final questionnaire for patients (18 items) and parents (15 items). The patient questionnaire includes four subscales, each with good internal consistency: Body Image Disturbance; Treatment Motivation/Engagement; Physical Limitations; and Social Disadvantage. The parent questionnaire includes 3 subscales: Body Image Disturbance; Treatment Motivation/Engagement; Physical Limitations. Patient and parent scales showed moderate correlations. Among patients with measures pre- and posttreatment, there was a significant improvement in overall PeCBI-QOL score. We demonstrate, in this study, that body image and related quality of life can be reliably and validly assessed with the PeCBI-QOL, which has implications for more comprehensively documenting the negative psychological and functional consequences of pectus carinatum. TYPE OF STUDY/LEVEL OF EVIDENCE: Study of diagnostic test/III.

Use of an Optical Scanning Device to Monitor the Progress of Noninvasive Treatments for Chest Wall Deformity: A Pilot Study.

BACKGROUND: The nonsurgical treatment of chest wall deformity by a vacuum bell or external brace is gradual, with correction taking place over months. Monitoring the progress of nonsurgical treatment of chest wall deformity has relied on the ancient methods of measuring the depth of the excavatum and the protrusion of the carinatum. Patients, who are often adolescent, may become discouraged and abandon treatment. METHODS: Optical scanning was utilized before and after the intervention to assess the effectiveness of treatment. The device measured the change in chest shape at each visit. In this pilot study, patients were included if they were willing to undergo scanning before and after treatment. Both surgical and nonsurgical treatment results were assessed. RESULTS: Scanning was successful in 7 patients. Optical scanning allowed a visually clear, precise assessment of treatment, whether by operation, vacuum bell (for pectus excavatum), or external compression brace (for pectus carinatum). Millimeter-scale differences were identified and presented graphically to patients and families. CONCLUSION: Optical scanning with the digital subtraction of images obtained months apart allows a comparison of chest shape before and after treatment. For nonsurgical, gradual methods, this allows the patient to more easily appreciate progress. We speculate that this will increase adherence to these methods in adolescent patients.

Nonoperative management of pectus excavatum with vacuum bell therapy: A single center study.

PURPOSE: The purpose of this study was to determine variables predictive of an excellent correction using vacuum bell therapy for nonoperative treatment of pectus excavatum. METHODS: A single institution, retrospective evaluation (IRB 15-01-WC-0024) of variables associated with an excellent outcome in pectus excavatum patients treated with vacuum bell therapy was performed. An excellent correction was defined as a chest wall depth equal to the mean depth of a reference group of 30 male children without pectus excavatum. RESULTS: Over 4years (11/2012-11/2016) there were 180 patients enrolled with 115 available for analysis in the treatment group. The reference group had a mean chest wall depth of 0.51cm. An excellent correction (depth≤0.51cm) was achieved in 23 (20%) patients. Patient characteristics predictive of an excellent outcome included initial age≤11years (OR=3.3,p=.013), initial chest wall depth≤1.5cm (OR=4.6,p=.003), and chest wall flexibility (OR=14.8,p<.001). Patients that used the vacuum bell over 12 consecutive months were more likely to achieve an excellent correction (OR=3.1,p=.030). Follow-up was 4months to 4years (median 12months). CONCLUSION: Nonoperative management of pectus excavatum with vacuum bell therapy results in an excellent correction in a small percentage of patients. Variables predictive of an excellent outcome include age≤11years, chest wall depth≤1.5cm, chest wall flexibility, and vacuum bell use over 12 consecutive months. TYPE OF STUDY: Retrospective chart review. LEVEL OF EVIDENCE: Level III treatment study.

Multivariate analysis of risk factors for Nuss bar infections: A single center study.

BACKGROUND/PURPOSE: Our previously published data suggested several risk factors for infection after the Nuss procedure. We aimed to further elucidate these findings. METHODS: An IRB-approved (14-03-WC-0034), single institution, retrospective review was performed to evaluate the incidence of postoperative Nuss bar infections associated with seven variables. These were subjected to bivariate and multivariable analyses. A broad definition of infection was used including cellulitis, superficial infection with drainage, or deep infection occurring at any time postoperatively. RESULTS: Over 7years (4/1/2009-7/31/2016), 25 (3.2%) of 781 patients developed a postoperative infection after primary Nuss repair. Multivariable analyses demonstrated an increased risk of infection with perioperative clindamycin versus cefazolin for all infections (AOR 3.72, p=.017), and specifically deep infections (AOR 5.72, p=.004). The risk of a superficial infection was increased when antibiotic infusion completed >60min prior to incision (AOR 10.4, p=.044) and with the use of peri-incisional subcutaneous catheters (OR 8.98, p=.008). CONCLUSION: Following primary Nuss repair, the rate of deep bar infection increased with the use of perioperative clindamycin rather than cefazolin. The rate of superficial infection increased when perioperative antibiotic infusion was completed more than 60min prior to incision and with the use of peri-incisional subcutaneous catheters. Further studies are needed to better understand these findings. TYPE OF STUDY: Retrospective chart review. LEVEL OF EVIDENCE: Level III treatment study.

Selective versus routine patch metal allergy testing to select bar material for the Nuss procedure in 932 patients over 10years.

AIM OF THE STUDY: The aim of the study was to determine the role of patch metal allergy testing to select bar material for the Nuss procedure. METHODS: An IRB-approved (11-04-WC-0098) single institution retrospective, cohort study comparing selective versus routine patch metal allergy testing to select stainless steel or titanium bars for Nuss repair was performed. In Cohort A (9/2004-1/2011), selective patch testing was performed based on clinical risk factors. In Cohort B (2/2011-9/2014), all patients were patch tested. The cohorts were compared for incidence of bar allergy and resultant premature bar loss. Risk factors for stainless steel allergy or positive patch test were evaluated. MAIN RESULTS: Cohort A had 628 patients with 63 (10.0%) selected for patch testing, while all 304 patients in Cohort B were tested. Over 10years, 15 (1.8%) of the 842 stainless steel Nuss repairs resulted in a bar allergy, and 5 had a negative preoperative patch test. The incidence of stainless steel bar allergy (1.8% vs 1.7%, p=0.57) and resultant bar loss (0.5% vs 1.3%, p=0.23) was not statistically different between cohorts. An allergic reaction to a stainless steel bar or a positive patch test was more common in females (OR=2.3, p<0.001) and patients with a personal (OR=24.8, p<0.001) or family history (OR=3.1, p<0.001) of metal sensitivity. CONCLUSION: Stainless steel bar allergies occur at a low incidence with either routine or selective patch metal allergy testing. If selective testing is performed, it is advisable in females and patients with a personal or family history of metal sensitivity. A negative preoperative patch metal allergy test does not preclude the possibility of a postoperative stainless steel bar allergy. LEVEL OF EVIDENCE: Level III Treatment Study and Study of Diagnostic Test.

Use of an Optical Scanning Device to Monitor the Progress of Noninvasive Treatments for Chest Wall Deformity: A Pilot Study

BACKGROUND: The nonsurgical treatment of chest wall deformity by a vacuum bell or external brace is gradual, with correction taking place over months. Monitoring the progress of nonsurgical treatment of chest wall deformity has relied on the ancient methods of measuring the depth of the excavatum and the protrusion of the carinatum. Patients, who are often adolescent, may become discouraged and abandon treatment. METHODS: Optical scanning was utilized before and after the intervention to assess the effectiveness of treatment. The device measured the change in chest shape at each visit. In this pilot study, patients were included if they were willing to undergo scanning before and after treatment. Both surgical and nonsurgical treatment results were assessed. RESULTS: Scanning was successful in 7 patients. Optical scanning allowed a visually clear, precise assessment of treatment, whether by operation, vacuum bell (for pectus excavatum), or external compression brace (for pectus carinatum). Millimeter-scale differences were identified and presented graphically to patients and families. CONCLUSION: Optical scanning with the digital subtraction of images obtained months apart allows a comparison of chest shape before and after treatment. For nonsurgical, gradual methods, this allows the patient to more easily appreciate progress. We speculate that this will increase adherence to these methods in adolescent patients.

Pectus excavatum repair after sternotomy: the Chest Wall International Group experience with substernal Nuss bars.

OBJECTIVES: Patients with pectus excavatum (PE) after prior sternotomy for cardiac surgery present unique challenges for repair of PE. Open repairs have been recommended because of concerns about sternal adhesions and cardiac injury. We report a multi-institutional experience with repair utilizing substernal Nuss bars in this patient population. METHODS: Surgeons from the Chest Wall International Group were queried for experience and retrospective data on PE repair using sub-sternal Nuss bars in patients with a history of median sternotomy for cardiac surgery (November 2000 to August 2015). A descriptive analysis was performed. RESULTS: Data for 75 patients were available from 14 centres. The median age at PE repair was 9.5 years (interquartile range 10.9), and the median Haller index was 3.9 (interquartile range 1.43); 56% of the patients were men. The median time to PE repair was 6.4 years (interquartile range 7.886) after prior cardiac surgery. Twelve patients (16%) required resternotomy before support bar placement: 7 pre-emptively and 5 emergently. Sternal elevation before bar placement was used in 34 patients (45%) and thoracoscopy in 67 patients (89%). Standby with cardiopulmonary bypass was available at 9 centres (64%). Inadvertent cardiac injury occurred in 5 cases (7%) without mortality. CONCLUSIONS: Over a broad range of institutions, substernal Nuss bars were used in PE repair for patients with a history of sternotomy for cardiac surgery. Several technique modifications were reported and may have facilitated repair. Cardiac injury occurred in 7% of cases, and appropriate resources should be available in the event of complications. Prophylactic resternotomy was reported at a minority of centres.

An Unusual Complication With the Administration of a Volatile Anesthetic Agent for Status Asthmaticus in the Pediatric Intensive Care Unit: Case Report and Review of the Literature.

In severe cases of status asthmaticus, when conventional therapies fail, volatile anesthetic agents remain a therapeutic option. When delivered outside of the operating room setting, specialized delivery techniques are needed to ensure the safe and effective use of volatile anesthetic agents. We present a 16-year-old adolescent with status asthmaticus who required the therapeutic administration of the volatile anesthetic agent, sevoflurane, in the pediatric intensive care unit (PICU). Although initially effective in reducing bronchospasm, progressive hypercarbia developed due to defective functioning of the carbon dioxide absorber of the anesthesia machine. This failure occurred as the soda lime compartment filled with water accumulated from circuit humidification and continuous albuterol therapy. The role of volatile anesthetic agents in the treatment of status asthmaticus in the PICU is discussed, options for delivery outside of the operating room presented, and potential problems with delivery reviewed.

Development of a new interfacility extracorporeal membrane oxygenation transport program for pediatric lung transplantation evaluation.

Pediatric lung transplantation is a life-saving intervention for children with irreversible end-stage lung disease. Access to transplant can be limited by geographic isolation from a center or the presence of comorbidities affecting transplant eligibility. Extracorporeal membrane oxygenation (ECMO)-supported patients are an uncommon but historically high-risk cohort of patients considered for lung transplant. We report the development of a service at our center to provide transport services to our hospital for patients unable to wean from ECMO support at their local institution for the purpose of evaluation for lung transplantation by our program. We developed a process for pre-transport consultation by the lung transplant physician team, standardized hand-off tools and equipment lists, and procedures for transitioning patients to transport ECMO machinery. Four patients have been transported to date including fixed wing (FW) and helicopter transports. All patients were successfully transported with either none or minor complications. Transport of ECMO-supported patients is a feasible method to increase access of patients with irreversible lung injured patients to evaluation for lung transplant.

Pediatric Extracorporeal Membrane Oxygenation Transport by EC-145 With a Custom-Built Sled.

Indications for the use of extracorporeal membrane oxygenation (ECMO) in pediatrics has expanded beyond the initial historic treatment of neonates with respiratory failure. Patients with severe refractory cardiopulmonary failure may benefit from ECMO support until the primary insult has subsided or been treated. More recently, ECMO has been used by some centers as a bridge to transplant for irreversible organ failure. Nationwide Children's Hospital is a referral center that supports the use of ECMO as a bridge to transplant and is able to provide transport services for ECMO patients referred for transplant evaluation. In this report, we describe our design of a unique, custom-built sled designed specifically for the EC-145 helicopter to transport pediatric ECMO patients to our institution. This report is the first, to our knowledge, to describe the safe and successful transport of a pediatric ECMO patient in an EC-145 helicopter.

Risk factors and management of Nuss bar infections in 1717 patients over 25 years.

PURPOSE: An increase in postoperative infections after Nuss procedures led us to seek risks and review management. We report potential risk factors and make inferences for prevention of infections. METHODS: An IRB-approved retrospective chart review was used to evaluate demographic, clinical, surgical, and postoperative variables of patients operated on between 10/1/2005 and 6/30/2013. Those with postoperative infection were evaluated for infection characteristics, management, and outcomes with univariate analyses. RESULTS: Over this 8-year period (2005-2013), 3.5% (30) of 854 patients developed cellulitis or infection, significantly more than 1.5% (13) in our previous report of 863 patients, 1987-2005 (p=.007). The most frequent organism cultured was methicillin-sensitive Staphylococcus aureus. Patients who were given clindamycin preoperatively (5 of 26 patients) had higher infection rates than those who received cefazolin (25 of 828) (19% vs 3%, p<.001). Patients treated with a peri-incisional ON-Q (I-Flow, Kimberly-Clark, Irvine, CA) also had higher infection rates (8.3% vs 2.4%, p<.001). Of the 30 patients who developed an infection, eighteen (60%) with cellulitis or superficial infections did not require surgical treatment or early bar removal. The other twelve patients (40%) with deep hardware infections required an average of 2.2 operations (range 1-6), with 3 (25%) requiring removal of their stabilizer and 3 (25%) requiring early bar removal. None of these three patients experienced recurrence of pectus excavatum at 2 to 4 years of follow-up. CONCLUSION: Preoperative antibiotic selection and use of ON-Q's may influence infection rates after Nuss repair. Nuss bars could be preserved in 90% of all patients with an infection and even 75% of those with a deep hardware infection. Attempts to retain the bar when an infection occurs may help prevent pectus excavatum recurrence. Level of Evidence=III.

Adjunctive and novel therapies for sepsis.

Primary goals of sepsis therapy include early, appropriate antimicrobial therapy and prompt recognition and reversal of shock. Despite these measures, however, sepsis remains an important source of pediatric morbidity and mortality. Here we review rationale and existing evidence in support of adjunctive sepsis therapies including extracorporeal support, immunomodulation, and mitochondria-targeted therapies. While each of these therapeutic modalities shows promise, additional studies are urgently needed to identify the right patients, the right timing, and the right context for these interventions.

Frequency-wavenumber processing for infrasound distributed arrays.

The work described herein discusses the application of a frequency-wavenumber signal processing technique to signals from rectangular infrasound arrays for detection and estimation of the direction of travel of infrasound. Arrays of 100 sensors were arranged in square configurations with sensor spacing of 2 m. Wind noise data were collected at one site. Synthetic infrasound signals were superposed on top of the wind noise to determine the accuracy and sensitivity of the technique with respect to signal-to-noise ratio. The technique was then applied to an impulsive event recorded at a different site. Preliminary results demonstrated the feasibility of this approach.

Glutathione reductase is essential for host defense against bacterial infection.

Glutathione reductase (Gsr) catalyzes the reduction of glutathione disulfide to glutathione, a major cellular antioxidant. We have recently shown that Gsr is essential for host defense against the gram-negative bacteria Escherichia coli in a mouse model of sepsis. Although we have demonstrated that Gsr is required for sustaining the oxidative burst and the development of neutrophil extracellular traps, the role of Gsr in other phagocytic functions remains unclear. It is also unclear whether Gsr-deficient mice exhibit host defense defects against gram-positive bacteria. In this study, we characterized the effects of Gsr deficiency on the innate immune responses to a gram-positive bacterium, group B Streptococcus, and to the gram-negative bacterial cell wall component lipopolysaccharide (LPS). We found that, like E. coli, group B Streptococcus resulted in a substantially more robust cytokine response and a markedly higher morbidity and mortality in Gsr-deficient mice than in wild-type mice. The increased morbidity and mortality were associated with greater bacterial burden in the Gsr-deficient mice. Interestingly, Gsr-deficient mice did not exhibit a greater sensitivity to LPS than did wild-type mice. Analysis of the neutrophils of Gsr-deficient mice revealed impaired phagocytosis. In response to thioglycollate stimulation, Gsr-deficient mice mobilized far fewer phagocytes, including neutrophils, macrophages, and eosinophils, into their peritoneal cavities than did wild-type mice. The defective phagocyte mobilization is associated with profound oxidation and aggregation of ascitic proteins, particularly albumin. Our results indicate that the oxidative defense mechanism mediated by Gsr is required for an effective innate immune response against bacteria, probably by preventing phagocyte dysfunction due to oxidative damage.