Mental Disorders Among Adolescents and Young Adults With Cancer: A Canadian Population-Based and Sibling Cohort Study

PURPOSE

To compare the cumulative incidence of mental disorders among adolescents and young adults (AYAs) diagnosed with cancer with the general population and their unaffected siblings.

METHODS

A retrospective, population-based, matched cohort design was used to investigate the impact of cancer diagnosis on mental disorders among individuals age 15-39 diagnosed between 1989 and 2019. Two cancer-free cohorts were identified: matched population-based and sibling cohorts. Outcomes included incidence of mood and anxiety disorders, substance use disorders, suicide outcomes, psychotic disorders, and any of the preceding four categories within 5 years of cancer diagnosis. Competing risk regression was used to estimate adjusted subhazard ratios (aSHR) and 95% CIs.

RESULTS

Among 3,818 AYAs with cancer matched to the population-based cancer-free cohort, individuals with cancer were more likely to be diagnosed with incident mental disorders than those without cancer; the risk was highest immediately after a cancer diagnosis and decreased over time with aSHR [95% CI] for mood and anxiety disorders at 0-6 months (11.27 [95% CI, 6.69 to 18.97]), 6-12 months (2.35 [95% CI, 1.54 to 3.58]), and 12-24 months (2.06 [95% CI, 1.55 to 2.75]); for substance use disorders at 0-6 months (2.73 [95% CI, 1.90 to 3.92]); for psychotic disorders at 0-6 months (4.69 [95% CI, 2.07 to 10.65]); and for any mental disorder at 0-6 months (4.46 [95% CI, 3.41 to 5.85]), 6-12 months (1.56 [95% CI, 1.14 to 2.14]), and 12-24 months (1.7 [95% CI, 1.36 to 2.13]) postcancer diagnosis. In sibling comparison, cancer diagnosis was associated with a higher incidence of mood and anxiety and any mental disorder during first 6 months of cancer diagnosis.

CONCLUSION

AYAs with cancer experience a greater incidence of mental disorders after cancer diagnosis relative to population-based and sibling cohorts without cancer, primarily within first 2 years, underscoring the need to address mental health concerns during this period.

CPAP Versus NIPPV Postextubation in Preterm Neonates: A Comparative-Effectiveness Study

BACKGROUND AND OBJECTIVES

Nasal intermittent positive pressure ventilation (NIPPV) has been shown to be superior to nasal continuous positive airway pressure (CPAP) postextubation in preterm neonates. However, studies have not permitted high CPAP pressures or rescue with other modes. We hypothesized that if CPAP pressures >8 cmH2O and rescue with other modes were permitted, CPAP would be noninferior to NIPPV.

METHODS

We conducted a pragmatic, comparative-effectiveness, noninferiority study utilizing network-based real-world data from 22 Canadian NICUs. Centers self-selected CPAP or NIPPV as their standard postextubation mode for preterm neonates <29 weeks' gestation. The primary outcome was failure of the initial mode ≤72 hours. Secondary outcomes included failure ≤7 days, and reintubation ≤72 hours and ≤7 days. Groups were compared using a noninferiority adjusted risk-difference (aRD) margin of 0.05, and margin of no difference.

RESULTS

A total of 843 infants extubated to CPAP and 974 extubated to NIPPV were included. CPAP was not noninferior (and inferior) to NIPPV for failure of the initial mode ≤72 hours (33.0% vs 26.3%; aRD 0.07 [0.03 to 0.12], Pnoninferiority(NI) = .86), and ≤7 days (40.7% vs 35.8%; aRD 0.09 [0.05 to 0.13], PNI = 0.97). However, CPAP was noninferior (and equivalent) to NIPPV for reintubation ≤72 hours (13.2% vs 16.1%; aRD 0.01 [-0.05 to 0.02], PNI < .01), and noninferior (and superior) for reintubation ≤7 days (16.4% vs 22.8%; aRD -0.04 [-0.07 to -0.001], PNI < .01).

CONCLUSIONS

CPAP was not noninferior to NIPPV for failure ≤72 hours postextubation; however, it was noninferior to NIPPV for reintubation ≤72 hours and ≤7 days. This suggests CPAP may be a reasonable initial postextubation mode if alternate rescue strategies are available.

Grade 7 school performance of children born preterm: a retrospective Canadian Cohort study

IMPORTANCE

Data on the middle school outcomes of preterm children are limited and have methodologic issues.

OBJECTIVE

To study the association between preterm birth and grade 7 school performance.

METHODS

A retrospective population-based cohort study of children born in Manitoba, Canada between 1994 and 2006 using their grade 7 school performance data. A secondary sibling cohort was created comprising children born preterm and their full-term siblings. Primary exposure was preterm birth categorized as <28, 28-33 and 34-36 weeks gestation. The two co-primary grade 7 outcome measures were: not meeting the mathematics competencies, and not meeting the student engagement competencies. Multivariable logistic regression models tested the association between preterm birth and both co-primary outcomes; adjusted odds ratios (aORs) and 95% confidence intervals (CIs) were calculated.

RESULTS

7653 preterm (gestational age median [IQR]: 35 weeks [34,36]) and 110,313 term (40 [39,40]) were included. 43% of < 28 weeks, 18% of 28-33 weeks and 17% of 34-36 weeks had the mathematics co-primary outcome compared to 13% of term children. The corresponding % for the student engagement outcome were 42%, 24%, 24% and 24% respectively. Preterm birth was associated with the mathematics (<28 weeks: 5.48, 3.89-7.70; 28-33 weeks: 1.47, 1.27-1.70; 34-36 weeks: 1.26, 1.16-1.35) and student engagement outcomes (<28 weeks: 2.49, 1.76-3.51; 28-33 weeks: 1.21, 1.06-1.39; 34-36 weeks: 1.09, 1.01-1.16). However, there was no difference in outcomes among the sibling cohort.

CONCLUSIONS AND RELEVANCE

Children born preterm had lower grade 7 performance compared to children born term in this population-based cohort. Screening and supports for them in their middle school years are warranted.

A Novel Integrated Clinical-Biochemical-Radiological and Sonographic Classification of Necrotizing Enterocolitis

OBJECTIVE

 To evaluate the sensitivity and specificity of clinical, laboratory, and radiological markers and the neonatologist-performed intestinal ultrasound (NP-IUS) for treatment interventions in preterm neonates who developed necrotizing enterocolitis (NEC).

STUDY DESIGN

 This was a case-control study of preterm neonates < 35 weeks with a diagnostic workup for NEC. The diagnostic workup included NP-IUS performed by trained neonatologists using a standard protocol, abdominal roentgenogram (AXR), and laboratory investigations. Intestinal ultrasound (IUS) performed by two neonatologists was standardized to detect 11 injury markers. AXRs were read independently by experienced pediatric radiologists. The investigators who retrospectively interpreted the IUS were blinded to the clinical and treatment outcomes.

RESULTS

 A total of 111 neonates were assessed. Fifty-four did not require intervention and formed the control group. Twenty cases were treated medically, 21 cases were treated with late surgery for stricture or adhesions, and 16 were treated with early surgery. The integrated model of cumulative severity of ultrasound markers, respiratory and hemodynamic instability, abdominal wall cellulitis, and C- reactive protein > 16 mg/L had an area under the curve (AUC) of 0.89 (95% confidence interval [CI]: 0.83-0.94%, p < 0.0001) for diagnosing NEC requiring surgical intervention. We also investigated the utility of Bell's classification to diagnose either the need for surgery or death, and it had an AUC of 0.74 (95% CI: 0.65-0.83%, p < 0.0001).

CONCLUSION

 In this cohort, a combination of specific IUS markers and clinical signs of instability, abdominal wall cellulitis, plus laboratory markers were diagnostic of NEC requiring interventions.

KEY POINTS

· The diagnosis of necrotizing enterocolitis requires a combination of markers.. · The combination of specific ultrasound markers, clinical signs, and laboratory markers were diagnostic of NEC requiring intervention.. · The intestinal ultrasound performed by a trained neonatologist was the most sensitive diagnostic marker of NEC requiring surgical intervention..

Hyperbilirubinemia Among Infants Born Preterm: Peak Levels and Association with Neurodevelopmental Outcomes

OBJECTIVE

To describe the distribution of peak bilirubin levels among infants born before 29 weeks of gestation in the first 14 days of life and to study the association between quartiles of peak bilirubin levels at different gestational ages and neurodevelopmental outcomes.

STUDY DESIGN

Multicenter, retrospective, nationwide cohort study of neonatal intensive care units in the Canadian Neonatal Network and Canadian Neonatal Follow-Up Network, including neonates born preterm at 220/7 to 286/7 weeks of gestation born between 2010 and 2018. Peak bilirubin levels were recorded during the first 14 days of age. Main outcome was significant neurodevelopmental impairment, defined as cerebral palsy with Gross Motor Function Classification System ≥3, or Bayley III-IV scores of <70 in any domain, or visual impairment, or bilateral hearing loss requiring hearing aids.

RESULTS

Among 12 554 included newborns, median gestational age was 26 weeks (IQR 25-28) and birth weight was 920 g (IQR 750-1105 g). The median peak bilirubin values increased as gestational age increased (112 mmol/L [6.5 mg/dL] at 22 weeks and 156 mmol/L [9.1 mg/dL] at 28 weeks). Significant neurodevelopmental impairment was identified in 1116 of 6638 (16.8%) of children. Multivariable analyses identified an association between peak bilirubin in the highest quartile and neurodevelopmental impairment (aOR 1.27, 95% CI 1.01-1.60) and receipt of hearing aid/cochlear implant (aOR 3.97, 95%CI: 2.01-7.82) compared with the lowest quartile.

CONCLUSION

In this multicenter cohort study, peak bilirubin levels in neonates of <29 weeks of gestation increased with gestational age. Peak bilirubin values in the highest gestational age-specific quartile were associated with significant neurodevelopmental and hearing impairments.

Grade 3 school performance among children born preterm: a population-based cohort study

OBJECTIVE

To study the association between prematurity and grade 3 school performance in a contemporary cohort of children.

METHODS

Population-based retrospective cohort study in Manitoba, Canada. Children born between 1999 and 2011 who had their grade 3 school performance data available were eligible. Preterm birth (<37 weeks) was the exposure of interest assessed using multivariable logistic regression models. Our primary outcomes were 'needs ongoing help' or 'outside the range' in at least two of each of the (1) four numeracy and (2) three reading competencies.

RESULTS

Of the 186 956 eligible children, 101 436 children (7187 preterm (gestational age, median (IQR) 35 weeks (34, 36)) and 94 249 term (40 weeks (39,40)) were included. Overall, 19% of preterm and 14% of term children had the numeracy outcome (adjusted OR (aOR) 1.38; 95% CI 1.29 to 1.47, p<0.001), while 19% and 13% had the reading outcome (aOR 1.38; 1.29 to 1.48, p<0.001). These differences showed a gestational age gradient. Gestational age (for numeracy, <28 weeks aOR 4.93 (3.45 to 7.03), 28-33 weeks 1.72 (1.50 to 1.98), 34-36 weeks 1.24 (1.15 to 1.34); for reading, <28 weeks 3.51 (2.40 to 5.14), 28-33 weeks 1.72 (1.49 to 1.98), 34-36 weeks 1.24 (1.17-1.37)), male sex, small for gestational age and maternal medical and sociodemographic factors were associated with the numeracy and reading outcomes in this cohort.

CONCLUSIONS AND RELEVANCE

Children born preterm had poorer performance in grade 3 numeracy and reading proficiencies than children born full term. All children born preterm, not just those born extremely preterm, should be screened for reading and numeracy performance in school and strategies implemented to address any deficits.

Mental Disorders Among Mothers of Children Born Preterm: A Population-Based Cohort Study in Canada

BACKGROUND

Our aim was to examine the association between preterm delivery and incident maternal mental disorders using a population-based cohort of mothers in Canada.

METHODS

Retrospective matched cohort study using Manitoba Centre for Health Policy (MCHP) administrative data in Manitoba. Mothers who delivered preterm babies (<37 weeks gestational age) between 1998 and 2013 were matched 1:5 to mothers of term babies using socio-demographic variables. Primary outcome was any incident mental disorder within 5 years of delivery defined as any of (a) mood and anxiety disorders, (b) psychotic disorders, (c) substance use disorders, and (d) suicide or suicide attempts. Multivariable Poisson regression model was used to estimate the 5-year adjusted incidence rate ratios (IRRs).

RESULTS

Mothers of preterm children (N   =   5,361) had similar incidence rates of any mental disorder (17.4% vs. 16.6%, IRR   =   0.99, 95% CI, 0.91 to 1.07) compared to mothers of term children (N   =   24,932). Mothers of term children had a higher rate of any mental disorder in the first year while mothers of preterm children had higher rates from 2 to 5 years. Being the mother of a child born <28 week (IRR   =   1.5, 95% CI, 1.14 to 2.04), but not 28-33 weeks (IRR   =   1.03, 95% CI, 0.86 to 1.19) or 34-36 weeks (IRR   =   0.96, 95% CI, 0.88 to 1.05), was associated with any mental disorder.

INTERPRETATION

Mothers of preterm and term children had similar rates of incident mental disorders within 5-years post-delivery. Extreme prematurity was a risk factor for any mental disorder. Targeted screening and support of this latter group may be beneficial.

School Readiness Among Children Born Preterm in Manitoba, Canada

Importance

Children born preterm may experience learning challenges at school. However, there is a paucity of data on the school readiness of these children as they prepare to begin grade 1.

Objective

To examine the association between prematurity and school readiness in a population-based cohort of children.

Design, Setting, and Participants

This cohort study was conducted in the province of Manitoba, Canada, and involved 2 cohorts of children in kindergarten at the time of data collection. The population-based cohort included children born between January 1, 2000, and December 31, 2011, whose school readiness was assessed in kindergarten using the Early Development Instrument (EDI) data. The sibling cohort comprised children born preterm and their closest-in-age siblings born full term. Data were analyzed between March 12 and September 28, 2021.

Exposures

Preterm birth, defined as gestational age (GA) less than 37 weeks.

Main Outcomes and Measures

The primary outcome was vulnerability in the EDI, defined as a score below the tenth percentile of the Canadian population norms for any 1 or more of the 5 EDI domains (physical health and well-being, social competence, emotional maturity, language and cognitive development, and communication skills and general knowledge). Logistic regression models were used to identify the factors associated with vulnerability in the EDI. P values were adjusted for multiplicity using the Simes false discovery method.

Results

Of 86 829 eligible children, 63 277 were included, of whom 4352 were preterm (mean [SD] GA, 34 [2] weeks; 2315 boys [53%]) and 58 925 were full term (mean [SD] GA, 39 (1) weeks; 29 885 boys [51%]). Overall, 35% of children (1536 of 4352) born preterm were vulnerable in the EDI compared with 28% of children (16 449 of 58 925) born full term (adjusted odds ratio [AOR], 1.32; 95% CI, 1.23-1.41; P < .001]). Compared with children born full term, those born preterm had a higher percentage of vulnerability in each of the 5 EDI domains. In the population-based cohort, prematurity (34-36 weeks' GA: AOR, 1.23 [95% CI, 1.14-1.33]; <34 weeks' GA: AOR, 1.72 [95% CI, 1.48-1.99]), male sex (AOR, 2.24; 95% CI, 2.16-2.33), small for gestational age (AOR, 1.31; 95% CI, 1.23-1.40), and various maternal medical and sociodemographic factors were associated with EDI vulnerability. In the sibling cohort, EDI outcomes were similar for both children born preterm and their siblings born full term except for the communication skills and general knowledge domain (AOR, 1.39; 95% CI, 1.07-1.80) and Multiple Challenge Index (AOR, 1.43; 95% CI, 1.06-1.92), whereas male sex (AOR, 2.19; 95% CI, 1.62-2.96) and maternal age at delivery (AOR, 1.53; 95% CI, 1.38-1.70) were associated with EDI vulnerability.

Conclusions and Relevance

Results of this study suggest that, in a population-based cohort, children born preterm had a lower school-readiness rate than children born full term, but this difference was not observed in the sibling cohort. Child and maternal factors were associated with lack of school readiness among this population-based cohort.

Point of care lung ultrasound service in neonatal intensive care: Five years of experience in Manitoba, Canada

OBJECTIVE

To evaluate the utility of a point of care lung ultrasound (POC-LUS) on patient management in the Neonatal Intensive Care Unit (NICU).

STUDY DESIGN

A retrospective cohort study of neonates who had POC-LUS from 2016 to 2020 in two-level III NICUs in Winnipeg, Manitoba, Canada. The primary outcome was the change in clinical management. The analysis aims mainly to describe the implementation process of the POC-LUS program.

RESULTS

A total of 956 neonates underwent 4076 POC-LUS studies during the study period. The number of POC-LUS studies increased significantly every year, from 316 (in 2016) to 1257 (in 2020) (p < 0.001). POC-LUS resulted in a change in clinical management following 2528 POC-LUS studies (62%), while it supported continuing the same management in 1548 studies (38%).

CONCLUSION

POC-LUS in Manitoba increased since its inception and led to an alteration in the clinical management in a significant proportion of patients who received the service.

Clinical burden associated with therapies for cardio-pulmonary critical decompensation in preterm neonates across Canadian neonatal intensive care units

The aim of this retrospective cohort study was to study the clinical burden associated with cardio-pulmonary critical decompensations (CPCDs) in preterm neonates and factors associated with mortality. Through the Canadian Neonatal Network (30 tertiary NICUs, 2010-2017), we identified infants < 32-week gestational age with CPCDs, defined by "significant exposure" to cardiotropes and/or inhaled nitric oxide (iNO): (1) either therapy for ≥ 3 consecutive days, (2) both for ≥ 2 consecutive days, or (3) any exposure within 2 days of death. Early CPCDs (≤ 3 days of age) and late CPCDs (> 3 days) were examined separately. Outcomes included CPCD-incidence, mortality, and inter-site variability using standardized ratios (observed/adjusted expected rate) and network funnel plots. Mixed-effects analysis was used to quantify unit-level variability in mortality. Overall, 10% of admissions experienced CPCDs (n = 2915). Late CPCDs decreased by ~ 5%/year, while early CPCDs were unchanged during the study period. Incidence and CPCD-associated mortality varied between sites, for both early (0.6-7.5% and 0-100%, respectively) and late CPCDs (2.5-15% and 14-83%, respectively), all p < 0.01. Units' late-CPCD incidence and mortality demonstrated an inverse relationship (slope =  -2.5, p < 0.01). Mixed-effects analysis demonstrated clustering effect, with 6.4% and 8.6% of variability in mortality after early and late CPCDs respectively being site-related, unexplained by available patient-level characteristics or unit volume. Mortality was higher with combined exposure than with only-cardiotropes or only-iNO (41.3%, 24.8%, 21.5%, respectively; p < 0.01).

CONCLUSIONS

Clustering effects exist in CPCD-associated mortality among Canadian NICUs, with higher incidence units showing lower mortality. These data may aid network-level benchmarking, patient-level risk stratification, parental counseling, and further research and quality improvement work.

WHAT IS KNOWN

• Preterm neonates remain at high risk of acute and chronic complications; the most critically unwell require therapies such as cardiotropic drugs and inhaled nitric oxide. • Infants requiring these therapies are known to be at high risk for adverse neonatal outcomes and for mortality.

WHAT IS NEW

• This study helps illuminate the national burden of acute cardio-pulmonary critical decompensation (CPCD), defined as the need for cardiotropic drugs or inhaled nitric oxide, and highlights the high risk of morbidity and mortality associated with this disease state. • Significant nationwide variability exists in both CPCD incidence and associated mortality; a clustering effect was observed with higher incidence sites showing lower CPCD-associated mortality.

Variations in practices and outcomes of neonates with hypoxic ischemic encephalopathy treated with therapeutic hypothermia across tertiary NICUs in Canada

OBJECTIVE

To characterize variations in practices and outcomes for neonates with hypoxic-ischemic encephalopathy (HIE) treated with therapeutic hypothermia (TH) across Canadian tertiary Neonatal Intensive Care Units (NICUs).

STUDY DESIGN

Retrospective study of neonates admitted for HIE and treated with TH in 24 tertiary NICUs from the Canadian Neonatal Network, 2010-2020. The two primary outcomes of mortality before discharge and MRI-detected brain injury were compared across NICUs using adjusted standardized ratios (SR) with 95% CI.

RESULTS

Of the 3261 neonates that received TH, 367 (11%) died and 1033 (37%) of the 2822 with MRI results had brain injury. Overall, rates varied significantly across NICUs for mortality (range 5-17%) and brain injury (range 28-51%). Significant variations in use of inotropes, inhaled nitric oxide, blood products, and feeding during TH were identified (p values < 0.01).

CONCLUSION

Significant variations exist in practices and outcomes of HIE neonates treated with hypothermia across Canada.

Targeted neonatal echocardiography service in neonatal intensive care in Manitoba, Canada

OBJECTIVE

To evaluate the impact of a targeted neonatal echocardiography (TNE) service on patient management in the neonatal intensive care units (NICU) in Winnipeg, Canada.

STUDY DESIGN

Retrospective cohort study of neonates who had TNEs from 2014 to 2019. The primary outcome was the change in clinical management based on TNE recommendation. Multivariate logistic regression analysis was used to identify predictors of the primary outcome.

RESULTS

A total of 747 echos were performed on 307 neonates. Patent ductus arteriosus assessment was the most common indication for TNE followed by evaluation of pulmonary hypertension and systemic hemodynamics. TNE led to a change in clinical management following 492 (66%) echos. Mechanical ventilation [Odds ratio (OR) 2.4, 95% CI: 1.7-3.4, P < 0.001) and receiving inhaled nitric oxide (1.9, 95% CI: 1.3-3.0, P = 0.003) were the predictors for the change in clinical management following TNE.

CONCLUSION

TNE has enhanced patient care by altering the management of patients in the NICU.

50 Poractant alfa versus bovine lipid extract surfactant for respiratory distress syndrome in preterm infants: A prospective comparative effectiveness cohort study

Primary Subject area

Neonatal-Perinatal Medicine

Background

There is a paucity of comparative effectiveness data for bovine lipid extract surfactant (BLES) and poractant alfa (Curosurf).

Objectives

To compare duration of respiratory support and short-term outcomes in very preterm infants treated with bovine lipid extract surfactant and poractant alfa.

Design/Methods

We performed a prospective, multicentre, comparative effectiveness study. Thirteen Canadian level III neonatal intensive care units (NICUs) provided bovine lipid extract surfactant to infants born &lt;32 weeks’ gestational age (GA) for a set period of time in the year 2019 (3 to 9 months), then changed to poractant alfa for the remainder of the year. The primary outcome was total duration of respiratory support (invasive and non-invasive). We utilized the Canadian Neonatal Network database for all study data.

Results

A total of 968 eligible infants (530 infants &lt; 28 weeks’ GA and 438 infants 280-316weeks’ GA) were included, of which 494 received bovine lipid extract surfactant and 474 received poractant alfa. In unadjusted analysis, no difference was observed in total duration of any respiratory support (median 38 vs. 40.5 days). After adjusting for baseline characteristics and accounting for cluster effects, infants treated with poractant alfa spent a median of 4.16 fewer days on respiratory support (95% CI 0.05, 8.28 days). This reduction was observed in the subgroup of infants 280-316 weeks’ GA, but not in those &lt; 28 weeks’ GA, and was explained by their shorter time on non-invasive respiratory support. No differences were observed in the need to re-dose surfactant, hospital mortality, bronchopulmonary dysplasia, or length of stay in NICU.

Conclusion

Administration of poractant alfa was associated with shorter median duration of respiratory support compared to bovine lipid extract surfactant in preterm neonates &lt; 32 weeks’ GA.

Effect of Vasopressin on Systemic and Pulmonary Hemodynamics in Neonates

OBJECTIVE

Despite its increasing use in neonates, the literature on the use of vasopressin (VP) in neonates is limited. The aim of this study is to evaluate the systemic and pulmonary effects of VP in neonates and to assess its safety among them.

STUDY DESIGN

This retrospective study enrolled all neonates in two level III neonatal intensive care units in Winnipeg, Manitoba, who had received VP therapy between 2011 and 2016. Infants with congenital malformations/chromosomal disorders were excluded. The changes in cardiovascular and pulmonary parameters were collected from patient charts. The primary outcome was the mean blood pressure (MBP) post-VP initiation. Secondary outcomes included systolic blood pressure (SBP) and diastolic blood pressure (DBP), vasoactive inotropic score (VIS), pH, urine output, lactate, base deficit (BD), mean airway pressure (MAP), and oxygen requirement.

RESULTS

A total of 33 episodes from 26 neonates were analyzed. The postnatal age at VP initiation was 14 days (interquartile range [IQR]: 4-25), and the median starting dose was 0.3 mU/kg/min (IQR: 0.2-0.5). MBP improved significantly after VP initiation from 28 to 39 mm Hg 24 hours after VP initiation (p < 0.001). Similar changes are observed with SBP and DBP. VIS declined from 15 to 6 at 24 hours, while pH, lactate, BD, and oxygen requirement improved significantly. While urine output marginally improved, there were no changes to MAP 24 hours post-VP initiation. Hyponatremia was observed in 21 episodes (64%) and severe hyponatremia in 7 episodes (33%).

CONCLUSION

VP appears to be a promising rescue therapy in catecholamine resistant shock or refractory pulmonary hypertension in neonates.

Relative effectiveness and safety of pharmacotherapeutic agents for patent ductus arteriosus (PDA) in preterm infants: a protocol for a multicentre comparative effectiveness study (CANRxPDA)

INTRODUCTION

Patent ductus arteriosus (PDA) is the most common cardiovascular problem that develops in preterm infants and evidence regarding the best treatment approach is lacking. Currently available medical options to treat a PDA include indomethacin, ibuprofen or acetaminophen. Wide variation exists in PDA treatment practices across Canada. In view of this large practice variation across Canadian neonatal intensive care units (NICUs), we plan to conduct a comparative effectiveness study of the different pharmacotherapeutic agents used to treat the PDA in preterm infants.

METHODS AND ANALYSIS

A multicentre prospective observational comparative-effectiveness research study of extremely preterm infants born <29 weeks gestational age with an echocardiography confirmed PDA will be conducted. All participating sites will self-select and adhere to one of the following primary pharmacotherapy protocols for all preterm babies who are deemed to require treatment.Standard dose ibuprofen (10 mg/kg followed by two doses of 5 mg/kg at 24 hours intervals) irrespective of postnatal age (oral/intravenous).Adjustable dose ibuprofen (oral/intravenous) (10 mg/kg followed by two doses of 5 mg/kg at 24 hours intervals if treated within the first 7 days after birth. Higher doses of ibuprofen up to 20 mg/kg followed by two doses of 10 mg/kg at 24 hours intervals if treated after the postnatal age cut-off for lower dose as per the local centre policy).Acetaminophen (oral/intravenous) (15 mg/kg every 6 hours) for 3-7 days.Intravenous indomethacin (0.1-0.3 mg/kg intravenous every 12-24 hours for a total of three doses).

OUTCOMES

The primary outcome is failure of primary pharmacotherapy (defined as need for further medical and/or surgical/interventional treatment following an initial course of pharmacotherapy). The secondary outcomes include components of the primary outcome as well as clinical outcomes related to response to treatment or adverse effects of treatment.

SITES AND SAMPLE SIZE

The study will be conducted in 22 NICUs across Canada with an anticipated enrollment of 1350 extremely preterm infants over 3 years.

ANALYSIS

To examine the relative effectiveness of the four treatment strategies, the primary outcome will be compared pairwise between the treatment groups using χ² test. Secondary outcomes will be compared pairwise between the treatment groups using χ² test, Student's t-test or Wilcoxon rank sum test as appropriate. To further examine differences in the primary and secondary outcomes between the four groups, multiple logistic or linear regression models will be applied for each outcome on the treatment groups, adjusted for potential confounders using generalised estimating equations to account for within-unit-clustering. As a sensitivity analysis, the difference in the primary and secondary outcomes between the treatment groups will also be examined using propensity score method with inverse probability weighting approach.

ETHICS AND DISSEMINATION

The study has been approved by the IWK Research Ethics Board (#1025627) as well as the respective institutional review boards of the participating centres.

TRIAL REGISTRATION NUMBER

NCT04347720.

Association between changes in urine output and successful indomethacin treatment for patent ductus arteriosus in preterm neonates

AIM

To investigate the relationship between changes in urine output during indomethacin treatment and ductal closure in preterm neonates.

METHODS

It is a retrospective study in neonates ≤32 weeks who had received two courses of indomethacin for PDA treatment over a 5-year period. Indomethacin courses with pre- and post-echocardiography confirmation of PDA status were included. Various urine output indices were collected and compared between successful versus unsuccessful indomethacin courses. Indomethacin treatment success was defined as: (i) where PDA closed or became haemodynamically insignificant (hisPDA) after treatment and (ii) only including neonates where PDA had complete closure after treatment. ROC analysis was performed to examine predictive ability of urine output during indomethacin for treatment success.

RESULTS

One hundred and eight indomethacin courses (first course: 52, second course: 56) in 80 neonates were included. The mean gestational age and birthweight were 25.4 ± 1.3 weeks and 762 ± 165 g, respectively. Irrespective of the definition used, there was no significant differences seen in any of urine output parameters between groups, except for a higher urine output during indomethacin associated with complete PDA closure (3.6 ± 1.3 vs. 3.0 ± 1.0 mL/kg/h, P = 0.02). The incidence of significant oliguria, hyponatraemia and need to withhold/delay indomethacin doses were also similar across groups.

CONCLUSION

Urine output was not a useful predictor of ductal response to indomethacin treatment in preterm neonates.

Prone versus Supine Position for Lung Ultrasound in Neonates with Respiratory Distress

OBJECTIVE

To study the feasibility of lung ultrasound (LUS) in prone position and to compare it with supine position in neonates with respiratory distress.

STUDY DESIGN

Neonates ≥ 29 weeks of gestational age with respiratory distress requiring respiratory support within first 12 hours of life were enrolled prospectively. First LUS (fLUS) was done in the position infant was nursed (supine or prone), infant's position changed, a second LUS (sLUS) was performed immediately and a third LUS (tLUS) was done 1 to 2 hours later. Primary outcome was the comparison of LUS scores (LUSsc) between fLUS and sLUS.

RESULTS

Sixty-four neonates were enrolled. Common respiratory diagnoses were transient tachypnea of newborn (TTN; 53%) and respiratory distress syndrome (RDS; 41%). LUSsc was different between fLUS and sLUS (fLUSsc 6 [interquatile range: 4, 7] vs. sLUSsc 7 [4, 10], p < 0.001), while there was no difference between the fLUS and tLUS (fLUSsc 6 [4, 7] vs. tLUSsc 5 [3, 7], p = 0.43). Subgroup analysis confirmed similar findings in neonates with TTN, while in babies with RDS, all the three LUSsc were similar.

CONCLUSION

LUS is feasible in prone position in neonates. LUS scores were higher immediately after a change in position but were similar to baseline 1 hour after the change in position.

Vasopressin for refractory persistent pulmonary hypertension of the newborn in preterm neonates - a case series

Objective: To describe the clinical outcomes following treatment with vasopressin for a sub-cohort of critically ill preterm neonates who have refractory persistent pulmonary hypertension of the newborn (PPHN).Design: Case seriesSetting: Tertiary neonatal intensive care unit, Toronto, Canada.Population: Neonates born <37 weeks gestational age (GA) who received vasopressin for refractory PPHN (lack of response to inhaled nitric oxide) over a 4-year period.Measurements: Changes in physiological indices of cardio-pulmonary stability during vasopressin therapy were analyzed using one-way repeated measures ANOVA, compared to pretreatment values. Data regarding survival to discharge and neurodevelopmental outcomes at 18-24 months were described.Main Results: Thirteen neonates with a mean GA of 31.4 ± 3.3 weeks were included. Vasopressin was initiated at 28.5 ± 4.5 h of age. Overall, oxygenation and hemodynamic variables improved significantly following vasopressin therapy (p < .05 at 24 h vs. pretreatment). Oxygenation failure resolved in 8 cases, of which 7 patients survived (6 without disability). Among the 5 cases where oxygenation failure persisted despite vasopressin, 4 died while one survived with disability.Conclusions: Vasopressin offers promise as a therapy for preterm neonates with refractory PPHN and hemodynamic instability, but prospective investigation is needed.

A call for a streamlined ethics review process for multijurisdictional, child health research studies

To be time and resource efficient in neonatal research and to answer clinically relevant questions with validity and generalizability, large numbers of infants from multiple hospitals need to be included. Multijurisdictional research in Canada is currently fraught with research ethics review process hurdles that lead to delays, administrative costs, and possibly termination of projects. We describe our experience applying for ethics review to 13 sites in 7 provinces for a project comparing two standard of care therapies for preterm born infants with respiratory distress syndrome. We welcome the current opportunity created by the Institute of Human Development Child and Youth Health and the Institute for Genetics, to collaboratively identify practical solutions that would benefit Canadian researchers, Research Ethics Boards, and children and families.

Clinical and echocardiography predictors of response to inhaled nitric oxide in hypoxic preterm neonates

AIM

To evaluate the clinical and echocardiography modulators of treatment response in hypoxemic preterm infants exposed to inhaled nitric oxide (iNO).

METHODS

In this multicentre retrospective study, clinical parameters, including oxygenation, ventilation and haemodynamics, were collected for preterm infants <36 weeks gestation before and 2 h after initiation of iNO for acute hypoxemia. Comprehensive echocardiography, performed near the time iNO initiation, was analysed by experts blind to the clinical course. Multiple logistic regression analysis was used to identify factors associated with iNO response as defined by a reduction in the fraction of inspired oxygen by >0.20.

RESULTS

A total of 213 infants met eligibility criteria, of which 73 had echocardiography data available and formed the study cohort. Response to iNO was demonstrated in 56% of patients. Younger post-natal age (odds ratio (OR) 0.94; 95% confidence interval (CI) 0.89, 0.99) and the presence of pulmonary hypertension (PH) (OR 4.47; 95% CI 1.23-11.9) were independently predictive of iNO response regardless of gestational age. Among neonates <72 h old with documented PH, iNO response was seen in 82%. The onset of a new diagnosis of severe (grade III/IV) intraventricular haemorrhage (IVH) after iNO treatment was seen in 6 of 40 patients <28 weeks' gestational age, with a greater frequency in responders (32 vs. 0%, P = 0.02).

CONCLUSIONS

Positive response to iNO is greatest in the first 3 days of life and in patients with echo-confirmed PH, independent of gestational age. The association between critical illness, iNO administration and IVH in extremely premature infants may merit prospective delineation.

A tunable magnetic metamaterial based on the dipolar four-state Potts model

Metamaterials, tunable artificial materials, are useful playgrounds to investigate magnetic systems. So far, artificial Ising spin systems have revealed features such as emergent magnetic monopoles^1,2 and charge fragmentation³. Here we present a metasystem composed of a lattice of dipolarly coupled nanomagnets. The magnetic spin of each nanomagnet is constrained to lie along a body diagonal, which yields four possible spin states. We show that the magnetic ordering of this metasystem (antiferromagnetic, ferromagnetic or spin ice like) is determined by the spin states orientation relative to the underlying lattice. The dipolar four-state Potts model explains our experimental observations and sheds light on the role of symmetry, as well as short- and long-range dipolar magnetic interactions, in such non-Ising spin systems.

Cardiac Air Embolism in Neonates: A Hemodynamic Perspective

Cardiac air embolism should be suspected in any neonate with acute unexplained cardiovascular collapse or worsening oxygenation. We present here five cases that presented with the above symptoms. A comprehensive evaluation including targeted neonatal echocardiography and near-infrared spectroscopy helped confirm the diagnosis and assess the hemodynamic state. Management was supportive including left lateral positioning, chest compressions, and cardiovascular medications to treat pulmonary hypertension and systemic hypotension.

Predictors of PDA Treatment in Preterm Neonates Who Had Received Prophylactic Indomethacin

OBJECTIVE

 To identify clinical factors those predict the need for patent ductus arteriosus (PDA) treatment in preterm neonates who had received prophylactic indomethacin.

PATIENTS AND METHODS

 Preterm neonates with <28 weeks' gestational age admitted to level III neonatal intensive care units (NICUs) in Canada between 2010 and 2015 and who had received prophylactic indomethacin were included. Primary outcome was surgical ligation of PDA, while secondary outcomes were any PDA treatment and common neonatal morbidities.

RESULTS

 Of the 7,024 eligible neonates, 843 (12%) neonates had received prophylactic indomethacin. Of them, 84 neonates (10%) required surgical ligation while 367 neonates (44%) received medical or surgical treatment for PDA. Logistic regression analyses identified gestational age (odds ratio [OR]: 0.71, 95% confidence interval [CI]: 0.58-0.87) and outborn status (OR: 2.07, 95% CI: 1.09-3.93) as predictors for surgical ligation. Maternal hypertension (OR: 0.57, 95% CI: 0.37-0.89), rupture of membranes (ROM) ≥24 hours (OR: 0.68, 95% CI: 0.48-0.96), and surfactant treatment (OR: 1.70, 95% CI: 1.09-2.66) were predictors for medical or surgical treatment of PDA.

CONCLUSION

 In extremely preterm neonates who had received prophylactic indomethacin, gestational age and outborn status were predictors for surgical ligation of PDA, while maternal hypertension, ROM ≥24 hours, and surfactant treatment were associated with the medical or surgical treatment of PDA.

Factors associated with non-response to second course indomethacin for PDA treatment in preterm neonates

BACKGROUND

Failure of first course of indomethacin (FCI) for patent ductus arteriosus (PDA) treatment in preterm neonates often prompts clinicians to consider a second course (SCI).

OBJECTIVE

To identify factors including baseline characteristics and response to FCI that are associated with non-response to SCI for PDA treatment in preterm neonates.

METHODS

In this retrospective observational study, neonates ≤32 weeks admitted to a tertiary NICU over 5 years who received two indomethacin courses for PDA treatment were reviewed. Only neonates with echocardiograms (ECHO) immediately before and after receipt of each indomethacin course were included. Primary outcome was non-response to SCI. Baseline characteristics and response to FCI were compared between responders and non-responders of SCI.

RESULTS

Of the 98 neonates enrolled, 47 (48%) had non-response to SCI. Of them, 27 patients (57%) had prior non-response to FCI, while of the 51 neonates who responded to SCI, 24 neonates (47%) had prior non-response to FCI. The adjusted risk of non-response to SCI in patients who had non-response to FCI was 37% higher (relative risk = 1.37, 95%CI: 0.87-1.80; p = .07) compared to those who had response to FCI. Multivariable analysis showed that increasing gestational age (AOR: 1.6, 95%CI: 1.1-2.3, p = .03) was associated with a higher odds of non-response to SCI while the odds of non-response to SCI increased by 90% in patients with non-response to FCI (AOR: 1.9, 95%CI: 0.8-4.5; p = .15) compared to those with success of FCI, although no statistical significance was observed.

CONCLUSIONS

Advanced gestational age was the predictor of non-response to SCI in preterm neonates.

Gastric bleeding risk following spleen preserving distal pancreatectomy with excision of the splenic vessels: a long-term follow-up

BACKGROUND

Spleen-preserving distal pancreatectomy with resection of the splenic vessels (VR-SPDP) is an effective procedure. However, hemodynamic changes in splenogastric circulation may lead to the development of gastric varices (GV) with a risk of gastrointestinal (GI) bleeding. This retrospective study aimed to assess the long-term postoperative clinical follow-up of patients and review the late postoperative abdominal computed tomography (CT) or endoscopic examination.

METHODS

From 1988 to 2015, 48 consecutive VR-SPDP for benign or low-grade malignant disease were included. Late postoperative follow-up was undertaken with the use of a prospective database and assessment undertaken by CT and/or endoscopy.

RESULTS

The median follow-up was 76 months (range: 12-334 months). Two patients were lost to follow-up. Gastrointestinal hemorrhage occurred in one patient. Endoscopy and abdominal CT showed submucosal GV in five patients. Ten patients had perigastric varices (27%), but none developed clinical complications from their varices. All varices occurred within one year after distal pancreatectomy and remained stable during follow-up.

DISCUSSION

Asymptomatic varices frequently occurred in patients who underwent VR-SPDP, but bleeding risk seemed low. Abdominal CT could identify GV and distinguish submucosal varices with a higher risk of gastric bleeding.

A Doppler velocimetry evaluation of intestinal blood flow characteristics in neonates receiving intravenous immunoglobulin therapy: a prospective observational study

OBJECTIVES

To evaluate intestinal blood flow changes after intravenous immunoglobulin (IVIg) infusion among neonates with Rh isoimmunization and alloimmune thrombocytopenia.

METHODS

This prospective observational study was conducted in level III NICU from July 2011 through August 2012. Thirty three consecutive instances (30 neonates) of IVIg treatment (1 g/kg) were studied. Celiac (CA) and superior mesenteric artery (SMA) doppler evaluations were performed immediately prior (baseline), immediately after and 12 to18 h following IVIg infusion. Peak systolic velocity, end diastolic velocity, time-averaged mean velocity, pulsatility index, resistive index and systolic/diastolic ratio were measured. The doppler indices measured immediately after and 12 to 18 h after IVIg infusion were compared with the baseline values.

RESULTS

The mean gestation and birth weight of the cohort were 36 ± 2 wk and 2597 ± 563 g respectively. Doppler flow variables measured immediately after and 12 to 18 h after IVIg were comparable to baseline values, in both the arteries. However, systolic/diastolic ratio in SMA immediately post-IVIg was lower than baseline, [median (IQR): 5 (3, 9) vs. 7 (4, 14), respectively; p=0.02]. None of the study infants developed feed intolerance or necrotizing enterocolitis (NEC).

CONCLUSIONS

There was no significant change in the celiac and SMA blood flows following IVIg therapy in neonates with Rh isoimmunization and alloimmune thrombocytopenia.

Size distribution of magnetic charge domains in thermally activated but out-of-equilibrium artificial spin ice

A crystal of emerging magnetic charges is expected in the phase diagram of the dipolar kagomé spin ice. An observation of charge crystallites in thermally demagnetized artificial spin ice arrays has been recently reported by S. Zhang and coworkers and explained through the thermodynamics of the system as it approaches a charge-ordered state. Following a similar approach, we have generated a partial order of magnetic charges in an artificial kagomé spin ice lattice made out of ferrimagnetic material having a Curie temperature of 475 K. A statistical study of the size of the charge domains reveals an unconventional sawtooth distribution. This distribution is in disagreement with the predictions of the thermodynamic model and is shown to be a signature of the kinetic process governing the remagnetization.

Intravenous immunoglobulin in isoimmune haemolytic disease of newborn: an updated systematic review and meta-analysis

BACKGROUND

Intravenous immunoglobulin (IVIg) is used in neonates with isoimmune haemolytic disease to prevent exchange transfusion (ET). However, studies supporting IVIg had methodological issues.

OBJECTIVE

To update the systematic review of efficacy and safety of IVIg in neonates with isoimmune haemolytic disease.

METHODS

MEDLINE, Embase databases and Cochrane Central Register of Controlled Trials (Cochrane Library) were searched (from inception to May 2013) for randomised or quasi-randomised controlled trials comparing IVIg with placebo/controls in neonates with isoimmune haemolytic disease without any language restriction. Three investigators assessed methodological quality of included trials. Meta-analyses were performed using random effect model and risk ratio (RR)/risk difference (RD) and mean difference with 95% CI calculated.

MAIN RESULTS

Twelve studies were included, ten trials (n=463) of Rh isoimmunisation and five trials (n=350) of ABO isoimmunisation (three studies had both population). Significant variations in risk of bias precluded an overall meta-analysis of Rh isoimmunisation. Studies with high risk of bias showed that IVIg reduced the rate of ET in Rh isoimmunisation (RR 0.23, 95% CI 0.13 to 0.40), whereas studies with low risk of bias that also used prophylactic phototherapy did not show statistically significant difference (RR 0.82, 95% CI 0.53 to 1.26). For ABO isoimmunisation, only studies with high risk of bias were available and meta-analysis revealed efficacy of IVIg in reducing ET (RR 0.31, 95% CI 0.18 to 0.55).

CONCLUSIONS

Efficacy of IVIg is not conclusive in Rh haemolytic disease of newborn with studies with low risk of bias indicating no benefit and studies with high risk of bias suggesting benefit. Role of IVIg in ABO disease is not clear as studies that showed a benefit had high risk of bias.

Pulse oximeter sensor application during neonatal resuscitation: a randomized controlled trial

OBJECTIVE

This study was done to compare 2 techniques of pulse oximeter sensor application during neonatal resuscitation for faster signal detection.

METHODS

Sensor to infant first (STIF) and then to oximeter was compared with sensor to oximeter first (STOF) and then to infant in ≥28 weeks gestations. The primary outcome was time from completion of sensor application to reliable signal, defined as stable display of heart rate and saturation. Time from birth to sensor application, time taken for sensor application, time from birth to reliable signal, and need to reapply sensor were secondary outcomes. An intention-to-treat analysis was done, and subgroup analysis was done for gestation and need for resuscitation.

RESULTS

One hundred fifty neonates were randomized with 75 to each technique. The median (IQR) time from sensor application to detection of reliable signal was longer in STIF group compared with STOF group (16 [15-17] vs. 10 [6-18] seconds; P <0.001). Time taken for application of sensor was longer with STIF technique than with STOF technique (12 [10-16] vs. 11 [9-15] seconds; P = 0.04). Time from birth to reliable signal did not differ between the 2 methods (STIF: 61 [52-76] seconds; STOF: 58 [47-73] seconds [P = .09]). Time taken for signal acquisition was longer with STIF than with STOF in both subgroups.

CONCLUSIONS

In the delivery room setting, the STOF method recognized saturation and heart rate faster than the STIF method. The time from birth to reliable signal was similar with the 2 methods.

Longitudinal growth of very low birth weight neonates during first year of life and risk factors for malnutrition in a developing country

AIMS

To study growth of very low birth weight neonates (VLBW) during first year and identify risk factors for malnutrition.

METHODS

Neonates ≤34 weeks and ≤1500 g enrolled in a human milk fortification trial were prospectively followed till 1 year corrected age (CA). Anthropometry was plotted on WHO charts. Risk factors were compared between well nourished and underweight infants.

RESULTS

One hundred and thirty-two, 127, 110, 99 and 101 neonates were followed at CA of 40 weeks, 3, 6, 9 and 12 months. Weight (Mean Z score -2.3 ± 1.2 to -1.7 ± 1.4; p = 0.005) and length (-2.1 ± 1.5 to -1.5 ± 1.3; p = 0.004) improved significantly, from 40 weeks to one year while head circumference declined (-0.92 ± 1.1 to -1.2 ± 1.1; p < 0.001). Incidence of underweight, stunting, microcephaly and wasting changed from 63%, 53%, 13% and 52% neonates at 40 weeks to 41%, 32%, 21% and 27% at one year. Growth between fortified and unfortified or small for gestational age (SGA) and appropriate for gestational age (AGA) groups were similar, while extremely low birth weight (ELBW) neonates showed poorer growth. Z score of weight at 3 months emerged as an independent predictor of malnutrition at one year.

CONCLUSION

VLBW neonates, especially the ELBW group remained growth retarded at CA of one year. Z score of weight at 3 months was a significant risk factor for malnutrition at one year.

Knowledge and practices of healthcare providers about essential newborn care and resuscitation in a district of Haryana

In India, institutionalisation of deliveries is happening at a fast pace. Evaluating the knowledge and practices of healthcare providers in these institutions is a priority in this current scenario. The objective of this study was to assess the knowledge and practices regarding essential newborn care and resuscitation among healthcare providers in Panchkula district of Haryana. A cross-sectional questionnaire based survey of healthcare personnel working in one district hospital, 2 community health centres, 5 primary health centres and 2 subcentres, each with at least 100 deliveries per year, was done. Fifty-eight medical personnel comprising of 27 staff nurses, 11 auxiliary nurse midwives, 15 doctors and 5 multipurpose health workers were interviewed. Of them, 33 (57%) had received training in newborn care, but only 9 (16%) knew all the initial steps of resuscitation. Twenty-eight (48%) had knowledge of positive pressure ventilation while 8 (13%) could provide chest compression or drugs during resuscitation. Thirty-three (57%) practiced holding the baby upside down after delivery. Early and exclusive breastfeeding including colostrum was advised by all. All practiced hand washing prior to delivery and kept the cord clean anddry. At least one danger sign was told to the mother at the time of discharge by 48 (83%). However, kangaroo mother care was rarely advised to mothers of preterm babies. It was found that majority of healthcare personnel had good awareness about breastfeeding and clean practices while conducting delivery. In contrast, knowledge about neonatal resuscitation and some aspects of essential newborn care was poor.

Microsurgery in liver research: end-to-side portocaval microanastomoses in dogfish

BACKGROUND

The use of an operating microscope in animal liver surgery has made it possible to obtain new experimental models. The goal of this prospective animal study is to present our experience with dogfish portocaval microanastomoses.

METHODS

Nineteen portocaval microanastomoses were performed in dogfish. The end-to-side anastomoses were accomplished using continuous 11-0 sutures. The diameter of the vessels and time required for the anastomoses were measured. A patency test and its outcome were also prospectively evaluated at the time of anastomoses and then 3 and 6 months after.

RESULTS

The mean vessel diameter was 2.5 ± 0.2mm. The mean anastomosis time was 14 ± 1.5 min. The anastomoses patency rate was 100% at the time of surgery. A postoperative control performed after 3 and 6 months showed a partial stenosis in three animals.

CONCLUSION

The dogfish appears to be a reliable experimental model in liver research. Moreover, this technique could be used for microsurgical training.