Open lung biopsy in pediatric patients on extracorporeal membrane oxygenation

Autopsy Histopathologic Lung Findings in Patients Treated With Extracorporeal Membrane Oxygenation

CONTEXT.—

Extracorporeal membrane oxygenation (ECMO) is increasingly used in the treatment of respiratory and cardiac failure, but data describing lung histopathology in ECMO recipients are limited.

OBJECTIVE.—

To examine pulmonary histopathologic findings in patients who underwent venovenous (VV) ECMO for pulmonary reasons or venoarterial (VA) ECMO for cardiac indications shortly before death, and to determine if the pulmonary changes provided insights into therapy that may prevent complications and improve outcome.

DESIGN.—

We conducted a retrospective study of lung autopsies, from VV and VA ECMO recipients and patients with acute respiratory distress syndrome (ARDS) and non-ECMO treatment, between 2008 and 2020 in Silesia Center for Heart Diseases in Zabrze, Poland.

RESULTS.—

Among 83 ECMO patients (42-64 years; men, 57 [68.7%]), the most common histopathologic findings were bronchopneumonia (44 [53.0%]), interstitial edema (40 [48.2%]), diffuse alveolar damage (DAD; 32 [38.6%]), hemorrhagic infarct (28 [33.7%]), and pulmonary hemorrhage (25 [30.1%]). DAD was associated with longer ECMO treatment and longer hospital stay. The use of VV ECMO was a predictor of DAD in patients with ARDS and undergoing ECMO, but it also occurred in 21 of 65 patients (32.3%) in the VA ECMO group, even though VA ECMO was used for heart failure.

CONCLUSIONS.—

Although DAD was significantly more common in lung autopsies of VV ECMO patients, one-third of VA ECMO patients had histopathologic changes characteristic of ARDS. The presence of DAD in lung autopsies of patients treated with VA ECMO indicates that in these patients, protective lung ventilation should be considered.

Case-based discussion: neonates on extracorporeal membrane oxygenation for undiagnosed recalcitrant pulmonary hypertension-management challenges

We present two neonates requiring extracorporeal membrane oxygenation for undiagnosed recalcitrant pulmonary hypertension, highlighting the clinical and ethical dilemmas in management of very rare diseases.

Surgery in Neonatal and Pediatric ECMO Patients Other Than Congenital Diaphragmatic Hernia Repair: A 10-Year Experience

Aim of Study: The use of extracorporeal membrane oxygenation (ECMO) has increased as a result of technological developments and the expansion of indications. Relatedly, the number of patients undergoing surgery during ECMO is also rising, at least in the adult population. Little is known on surgery in children during ECMO-therapy. We therefore aimed to assess the frequencies and types of surgical interventions in neonatal and pediatric patients on ECMO and to analyze surgery-related morbidity and mortality. Methods: We retrospectively collected information of all patients on ECMO over a 10-year period in a single tertiary and designated ECMO-center, excluding patients undergoing cardiac surgery, and correction of congenital diaphragmatic hernia. Chi-squared test and Mann-Whitney U test were used to analyze data. Main Results: Thirty-two of 221 patients (14%) required surgery when on ECMO. Common interventions were thoracotomy (32%), laparotomy (23%), fasciotomy (17%), and surgical revision of ECMO (15%). Complications occurred in 28 cases (88%), resulting in a 50% in-hospital mortality rate. Surgical patients had a longer ICU stay and longer total hospital stay compared to those not receiving surgery during ECMO. No significant difference in mortality was found when comparing surgical to non-surgical patients (50 vs. 41%). Conclusions: Approximately one in seven neonatal or pediatric patients required surgical intervention during ECMO, of whom almost 90% developed a complication, resulting in a 50% mortality rate. These results should be taken into account in counseling.

Interstitial lung disease in infancy

There is a wide differential diagnosis of early onset respiratory distress especially in term babies, and interstitial lung disease (chILD) is a rare but important consideration in this context. chILD manifesting immediately after birth is usually related to mutations in surfactant protein genes, or conditions related to the Congenital Acinar Dysplasia -Alveolar capillary dysplasia - Congenital Alveolar Dysplasia (CAD-ACD) spectrum. There is currently no specific treatment for these conditions, and management is supportive. Prognosis is very poor in most of these babies if onset is early, with relentless respiratory deterioration unless transplanted. Ideally, the diagnosis is made on genetic analysis, but this may be time-consuming and complex in CAD-ACD spectrum, so lung biopsy may be needed to avoid prolonged and futile treatment being instituted. Milder forms with prolonged survival have been reported. Early onset, less severe chILD is usually related to neuroendocrine cell hyperplasia of infancy (NEHI), pulmonary interstitial glycogenosis (PIG) and less severe disorders of surfactant proteins. PIG and NEHI are not specific entities, but are pulmonary dysmaturity syndromes, and there may be a number of underlying genetic and other cause. If the child is stable and thriving, many will not be subject to lung biopsy, and slow improvement and weaning of supplemental oxygen can be anticipated. Where possible, a precise genetic diagnosis should be made in early onset cHILD allow for genetic counselling. chILD survivors and their families have complex respiratory and other needs, and co-ordinated, multi-disciplinary support in the community is essential.

Percutaneous Lung Biopsy in Immunocompromised Pediatric Patients

PURPOSE

To determine the diagnostic yield and safety of image-guided lung biopsies in immunocompromised pediatric patients.

MATERIALS AND METHODS

This was a retrospective pediatric cohort study conducted from June 2000 to April 2017. Subjects were 0-17 years of age (median, 10 years of age). There were 46 males (48%). A total of 73 consecutive image-guided lung biopsies were performed in 68 patients (weight range, 4.9-97.3 kg [median, 25.3 kg]). The indication for biopsy was to isolate an organism to tailor medical therapy. All patients were immunocompromised with an underlying history of bone marrow transplantation (n = 50), primary immunodeficiency (n = 14), and solid organ transplantation (n = 4). Patient and technical factors were analyzed for rates of complication.

RESULTS

Overall diagnostic yield was 43 of 73 patients (60%). There were 14 minor (19%) and 8 major (11%) complications. Major complications included pneumothorax or hemoptysis requiring intervention (n = 6), and death (n = 2). The histological diagnosis was an infectious cause in 5 of 8 major complications (63%). There were statistically significant differences between the rates of complications with the imaging modality used (P = .02) and the use of fine needle aspiration (P = .02).

CONCLUSIONS

Image-guided percutaneous lung biopsy can be helpful in isolating an organism to tailor therapy. Biopsies performed in immunosuppressed patients result in an elevated complication risk of up to 30% and demonstrate lower diagnostic yield and increased mortality, which should warrant detailed discussion with the primary team and family.

Histopathologic Findings in Lungs of Patients Treated With Extracorporeal Membrane Oxygenation

BACKGROUND

The outcome of extracorporeal membrane oxygenation (ECMO) might be influenced by its complications. Only limited information is available regarding the pathologic consequences of ECMO, especially in the era of modern ECMO technology.

METHODS

We studied the histopathologic findings in autopsy lungs of patients treated with ECMO compared with those without ECMO. Autopsy files were queried for cases with ECMO. An age- and sex-matched control group comprised of patients who died in the ICU without acute respiratory distress syndrome, pneumonia, or ECMO was compared with patients with ECMO for cardiac reason. Histopathology and medical records were reviewed.

RESULTS

Seventy-six patients treated with ECMO (38 men; median age, 40 years) and 47 control patients (23 men; median age, 45 years) were included. Common histologic pulmonary findings in the ECMO group were pulmonary hemorrhage (63.2%), acute lung injury (60.5%), thromboembolic disease (47.4%), calcifications (28.9%), vascular changes (21.1%), and hemorrhagic infarct (21.1%). Pulmonary hemorrhage was associated with longer ECMO duration (median, 7.0 vs 3.5 months; P = .014), acute lung injury with venovenous ECMO (91.7% vs 54.7%; P = .039) and longer ECMO (6.0 vs 4.0 months; P = .044), and pulmonary calcifications with infants (50.0% vs 22.4%; P = .024). Patients with ECMO for cardiac reasons (n = 60) more frequently showed pulmonary hemorrhage (P < .001), diffuse alveolar damage (P = .044), thromboembolic disease (P = .004), hemorrhagic infarct (P = .002), pulmonary calcifications (P = .002), and vascular changes (P = .001) than patients in the non-ECMO group.

CONCLUSIONS

Some findings are suspected to be associated with the patient's underlying disease, whereas others might be related to ECMO. Our results provide a better understanding of ECMO-related lung disease and might help to prevent it.

Risk and relevance of open lung biopsy in pediatric ECMO patients: the Dutch experience

BACKGROUND

Open lung biopsy can help differentiate between reversible and irreversible lung disease and may guide therapy. To assess the risk-benefit ratio of this procedure in pediatric extracorporeal membrane oxygenation (ECMO) patients, we reviewed data of all patients who underwent an open lung biopsy during ECMO in one of the two pediatric ECMO centers in a nationwide study in the Netherlands.

RESULTS

In nineteen neonatal and six pediatric patients (0-15.5years), twenty-five open lung biopsies were performed during the study period. In 13 patients (52%), a classifying diagnosis of underlying lung disease could be made. In another nine patients (36%), specific pathological abnormalities were described. In three patients (12%), only nonspecific abnormalities were described. The histological results led to withdrawal of ECMO treatment in 6 neonates with alveolar capillary dysplasia/misalignment of pulmonary veins (24%) and in another 6 patients, corticosteroids were started (24%). All patients survived the biopsy procedure. Hemorrhagic complications were rare.

CONCLUSION

An open lung biopsy during an ECMO run in neonates and children is a safe procedure with a minimum risk for blood loss and biopsy-related death. It can be very useful in diagnosing the underlying pathology and can guide cessation of ECMO treatment and thereby avoid continuation of futile treatment, especially in neonatal patients.

LEVEL OF EVIDENCE

III.

TYPE OF STUDY

Diagnostic study.

Examining Noncardiac Surgical Procedures in Patients on Extracorporeal Membrane Oxygenation

As extracorporeal membrane oxygenation (ECMO) is increasingly used for patients with cardiac and/or pulmonary failure, the need for noncardiac surgical procedures (NCSPs) in these patients will continue to increase. This study examined the NCSP required in patients supported with ECMO and determined which variables affect outcomes. The National Inpatient Sample Database was examined for patients supported with ECMO from 2007 to 2010. There were 563 patients requiring ECMO during the study period. Of these, 269 (47.8%) required 380 NCSPs. There were 149 (39.2%) general surgical procedures, with abdominal exploration/bowel resection (18.2%) being most common. Vascular (29.5%) and thoracic procedures (23.4%) were also common. Patients requiring NCSP had longer median length of stay (15.5 vs. 9.2 days, p = 0.001), more wound infections (7.4% vs. 3.7%, p = 0.02), and more bleeding complications (27.9% vs. 17.3%, p = 0.01). The incidences of other complications and inpatient mortality (54.3% vs. 58.2%, p = 0.54) were similar. On logistic regression, the requirement of NCSPs was not associated with mortality (odds ratio [OR]: 0.91, 95% confidence interval [CI]: 0.68-1.23, p = 0.17). However, requirement of blood transfusion was associated with mortality (OR: 1.70, 95% CI: 1.06-2.74, p = 0.03). Although NCSPs in patients supported with ECMO does not increase mortality, it results in increased morbidity and longer hospital stay.

Pre-cannulation lung biopsy shortens ECMO course

We describe the clinical course of an infant with respiratory failure who underwent lung biopsy prior to cannulation for undergoing extracorporeal membrane oxygenation (ECMO). Pathology revealed alveolar capillary dysplasia, and ECMO was discontinued. Rapid diagnosis allowed for closure and saved resources. We recommend considering early biopsy in infants with atypical pulmonary hypertension.

The use of early lung biopsy in detection of fatal pulmonary disease in the neonate

We report a case of alveolar capillary dysplasia with misaligned pulmonary veins and review the literature to highlight the importance of lung biopsy, which can affect the decision to use invasive and likely ineffective therapy such as extracorporeal membrane oxygenation.

An official American Thoracic Society clinical practice guideline: classification, evaluation, and management of childhood interstitial lung disease in infancy

BACKGROUND

There is growing recognition and understanding of the entities that cause interstitial lung disease (ILD) in infants. These entities are distinct from those that cause ILD in older children and adults.

METHODS

A multidisciplinary panel was convened to develop evidence-based guidelines on the classification, diagnosis, and management of ILD in children, focusing on neonates and infants under 2 years of age. Recommendations were formulated using a systematic approach. Outcomes considered important included the accuracy of the diagnostic evaluation, complications of delayed or incorrect diagnosis, psychosocial complications affecting the patient's or family's quality of life, and death.

RESULTS

No controlled clinical trials were identified. Therefore, observational evidence and clinical experience informed judgments. These guidelines: (1) describe the clinical characteristics of neonates and infants (<2 yr of age) with diffuse lung disease (DLD); (2) list the common causes of DLD that should be eliminated during the evaluation of neonates and infants with DLD; (3) recommend methods for further clinical investigation of the remaining infants, who are regarded as having "childhood ILD syndrome"; (4) describe a new pathologic classification scheme of DLD in infants; (5) outline supportive and continuing care; and (6) suggest areas for future research.

CONCLUSIONS

After common causes of DLD are excluded, neonates and infants with childhood ILD syndrome should be evaluated by a knowledgeable subspecialist. The evaluation may include echocardiography, controlled ventilation high-resolution computed tomography, infant pulmonary function testing, bronchoscopy with bronchoalveolar lavage, genetic testing, and/or lung biopsy. Preventive care, family education, and support are essential.

Outcomes of neonates requiring extracorporeal membrane oxygenation for irreversible pulmonary dysplasia: the Extracorporeal Life Support Registry experience

OBJECTIVE

Neonates with an irreversible pulmonary dysplasia such as alveolar capillary dysplasia, surfactant protein deficiency, and pulmonary lymphangiectasis may have a deteriorating clinical course requiring cardiopulmonary support with extracorporeal membrane oxygenation. These neonates are often difficult to distinguish from those with persistent pulmonary hypertension of the newborn. The objective of this study was to identify clinical variables that distinguish infants with irreversible pulmonary dysplasia from those with persistent pulmonary hypertension of the newborn before, and while receiving, extracorporeal membrane oxygenation support.

DESIGN

A retrospective analysis of the Extracorporeal Life Support Registry from 2000 to 2010 was performed.

SETTING

A total of 114 extracorporeal membrane oxygenation centers providing data to the Extracorporeal Life Support Registry.

PATIENTS

All neonates day of life 0-31 reported to the Extracorporeal Life Support Registry with irreversible pulmonary dysplasia and persistent pulmonary hypertension of the newborn were identified.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

Patient demographics, pre-extracorporeal membrane oxygenation variables, and survival were analyzed. Univariate analysis was performed using Student's t test or Fisher's exact test, and variables found to be significant underwent multivariate analysis by logistic regression. Neonates with irreversible pulmonary dysplasia were placed on extracorporeal membrane oxygenation later (day of life 5.3 vs. 3.0, p = .045) and for a longer duration (11.1 vs. 6.8 days, p < .001) than those with persistent pulmonary hypertension of the newborn. Initiation of extracorporeal membrane oxygenation at day of life ≥5 (p = .026) and a duration of extracorporeal membrane oxygenation ≥10 days (p = .003) were independent predictors of irreversible pulmonary dysplasia by multivariate analysis. No differences in demographics, blood gas values, or vascular access were observed. Survival to discharge was significantly lower for neonates with irreversible pulmonary dysplasia (3%) vs. persistent pulmonary hypertension of the newborn (81%, p < .001).

CONCLUSION

Although neonates with irreversible pulmonary dysplasia and persistent pulmonary hypertension of the newborn have similar presentations, those with irreversible pulmonary dysplasia require extracorporeal membrane oxygenation support later in the perinatal period and for a longer duration. For neonates with a diagnosis of persistent pulmonary hypertension of the newborn, irreversible pulmonary dysplasia should be considered when extracorporeal membrane oxygenation is initiated on day of life ≥5 and/or the duration of extracorporeal membrane oxygenation ≥10 days.

16q24.1 microdeletion in a premature newborn: usefulness of array-based comparative genomic hybridization in persistent pulmonary hypertension of the newborn

OBJECTIVE

Report of a 16q24.1 deletion in a premature newborn, demonstrating the usefulness of array-based comparative genomic hybridization in persistent pulmonary hypertension of the newborn and multiple congenital malformations.

DESIGN

Descriptive case report.

SETTING

Genetic department and neonatal intensive care unit of a tertiary care children's hospital.

INTERVENTIONS

None.

PATIENT

We report the case of a preterm male infant, born at 26 wks of gestation. A cardiac malformation and bilateral hydronephrosis were diagnosed at 19 wks of gestation. Karyotype analysis was normal, and a 22q11.2 microdeletion was excluded by fluorescence in situ hybridization analysis. A cesarean section was performed due to fetal distress. The patient developed persistent pulmonary hypertension unresponsive to mechanical ventilation and nitric oxide treatment and expired at 16 hrs of life.

MEASUREMENTS AND MAIN RESULTS

An autopsy revealed partial atrioventricular canal malformation and showed bilateral dilation of the renal pelvocaliceal system with bilateral ureteral stenosis and annular pancreas. Array-based comparative genomic hybridization analysis (Agilent oligoNT 44K, Agilent Technologies, Santa Clara, CA) showed an interstitial microdeletion encompassing the forkhead box gene cluster in 16q24.1. Review of the pulmonary microscopic examination showed the characteristic features of alveolar capillary dysplasia with misalignment of pulmonary veins. Some features were less prominent due to the gestational age.

CONCLUSIONS

Our review of the literature shows that alveolar capillary dysplasia with misalignment of pulmonary veins is rare but probably underreported. Prematurity is not a usual presentation, and histologic features are difficult to interpret. In our case, array-based comparative genomic hybridization revealed a 16q24.1 deletion, leading to the final diagnosis of alveolar capillary dysplasia with misalignment of pulmonary veins. It emphasizes the usefulness of array-based comparative genomic hybridization analysis as a diagnostic tool with implications for both prognosis and management decisions in newborns with refractory persistent pulmonary hypertension and multiple congenital malformations.

Alveolar capillary dysplasia: absence of CD117 immunoreactivity of putative hemangioblast precursor cells

Alveolar capillary dysplasia is a rare cause of irreversible persistent pulmonary hypertension in newborns resulting from failure of formation of peripheral capillary loops with consequent reduction in the blood-gas barrier. The basic defect in morphogenesis is unknown, although it is postulated that there is a structural abnormality of the hemangioblast precursors of the primitive lung mesenchyme in the septal regions of the developing lung leading to abnormal vasculogenesis. Two cases of alveolar capillary dysplasia evaluated immunohistochemically showed uniform CD117 negativity in the septal interstitial cells forming the pulmonary capillaries. A series of 12 control cases showed positive immunoreactivity for CD117 in a subset of septal interstitial cells forming the putative hemangioblast precursor cells. This novel finding is a useful adjunctive diagnostic tool and may support the hypothesis that absence of putative CD117-positive hemangioblast precursor cells is a key structural defect. This defect results in abnormal vasculogenesis and consequent failure of formation of an adequate blood-gas barrier.

Versatile use of extra-corporeal life support to resuscitate acute respiratory distress patients

Extra-corporeal life support (ECLS) has been applied successfully to congenital respiratory defects but less optimally to acquired pulmonary failure. We extended this support to certain extreme complexities of patients with acute respiratory distress. From January 2003 to June 2005, 16 (nine men and seven women) patients refractory to ventilator support were treated with ECLS. Their median age was 32.4 years (1.5-70). The triggering events were pulmonary haemorrhage (n = 4), pneumonia (n = 7), aspiration (n = 2) and pancreatitis (n = 3). The indications for support were hypoxaemia in 13 and hypercapnia in three patients. Ten (63%) met the criteria of fast entry. Thirteen (81%) received veno-venous (V-V) mode support and the other three received veno-arterial mode support initially, but then converted to V-V mode after sufficient oxygenation stabilised haemodynamics. Initial pump flow was maximised to improve (mean 3250 +/- 1615 ml/min) to improve the oxygenation. Four patients with active pulmonary haemorrhage were heparin free in the first 12-24 h of support without complications. Excluding one prematurely terminated patient because of brain permanent damage, the duration of support was 162 +/- 95 h (67-363). Eleven (69%) weaned successfully from ECLS and 10 (63%) discharged and regained normal pulmonary performance in a median of 26.8 months follow-up. Pulmonary support using ECLS was feasible in selected patients with acute respiratory distress. Modification of guidelines for liberal use, early deployment before secondary organ damage and prevention of complications during support were the key to final success.

Pulmonary sarcoidosis in a 14-year-old boy diagnosed by low-dose CT-guided transthoracic lung biopsy

Pulmonary sarcoidosis is a rare disease in the pediatric age group, characterized by the presence of epitheloid-cell granulomas. In stage 3 sarcoidosis, pulmonary infiltrates without hilar lymphadenopathy occur. Definitive diagnosis requires a histopathological specimen, which might be difficult to obtain by transbronchial biopsy. Multidetector computed tomography (MDCT)-guided transthoracic lung biopsy (TLB) is a well-established procedure in adults, but has only rarely been applied in children.A 14-year-old boy was admitted to hospital for evaluation of a chronic systemic disease with severe pulmonary manifestation. All investigations, including bronchosopy and bronchoalveolar lavage with microbiological and virological testing, had been negative. MDCT-guided TLB was performed on a 16-section scanner with a low-dose protocol (single slices, 120 kV, 20 mAs), using a 16-gauge biopsy device. The total effective dose was 0.4 mSv for the biopsy procedure. Histopathological examination revealed multiple epitheloid-cell granulomas with giant cells in the absence of microbiological or virological abnormalities. A diagnosis of stage 3 pulmonary sarcoidosis was made and systemic anti-inflammatory therapy was administered, which led to complete remission within weeks. MDCT-guided TLB can be a valuable instrument in assessing pulmonary manifestations of pediatric sarcoidosis, enabling precise histopathological diagnosis and adequate therapy. The use of low-dose protocols can substantially reduce radiation exposure without relevant loss of image information. MDCT-guided lung biopsy should be considered prior to open-lung surgery in selected patients with unclear pulmonary disease.

Alveolar capillary dysplasia: a logical approach to a fatal disease

PURPOSE

The aim of the study was to review the authors' experience with alveolar capillary dysplasia (ACD), a cause of persistent pulmonary hypertension of the neonate (PPHN) caused by decreased alveolar units, dilated anomalous pulmonary veins, thick-walled arterioles, and thickened interalveolar septa.

METHODS

The records of all neonates with ACD were reviewed from Children's Hospital, Columbus, Ohio, and Sophia's Children's Hospital, Rotterdam, The Netherlands. The clinical characteristics and pathological findings are discussed.

RESULTS

Eight neonates were diagnosed with ACD from 1994 to 2002. Twenty-five percent (2/8) experienced respiratory distress immediately after birth, whereas 75% (6/8) had normal Apgar scores but deteriorated 1.5 hours to 30 days after birth. All infants required conventional ventilation initially; 50% (4/8) were placed on high-frequency oscillating ventilation and 87% (7/8) on extracorporeal membrane oxygenation. A premorbid diagnosis was established in 3 patients by open lung biopsy. The diagnosis of ACD was confirmed at autopsy in all patients.

CONCLUSIONS

ACD is a fatal disease that should be suspected in all neonates with respiratory failure and PPHN who fail conventional therapy. Prompt diagnosis helps to avoid prolongation of costly treatment modalities in a uniformly fatal disease. An algorithm is proposed in which neonates with PPHN who fail treatment with extracorporeal membrane oxygenation are managed by open lung biopsy.

Histopathological features of open lung biopsies in children treated with extracorporeal membrane oxygenation (ECMO)

BACKGROUND

Extracorporeal membrane oxygenation (ECMO) has become an established treatment for severe respiratory distress in a range of pediatric conditions. This study describes the histopathological features in a series of 22 children receiving ECMO therapy in whom open lung biopsy was carried out.

AIMS

To describe the histopathological features of open lung biopsies in children receiving ECMO therapy.

STUDY DESIGN

Retrospective review of clinical material.

SUBJECTS

Children receiving ECMO therapy in whom open lung biopsy was carried out.

RESULTS

In those investigated in infancy, open lung biopsy allowed a definite diagnosis to be made of the underlying condition in more than 90% of cases. In older children, the histopathological changes were more non-specific and, although providing useful clinical information, a definitive diagnosis could often not be made. In about a quarter of cases, there are additional pathological features, which may be related to ECMO treatment, such as significant intra-alveolar haemorrhage, but ECMO does not in itself impair the diagnostic usefulness of open lung biopsy in these selected patients.

CONCLUSION

Open lung biopsy provides clinically useful information in infants receiving ECMO therapy. The histopathological changes may be complex and represent both the effects of ECMO and progression of the underlying disease.

Evaluation of chronic infectious interstitial pulmonary disease in children by low-dose CT-guided transthoracic lung biopsy

BACKGROUND

Children with chronic infectious interstitial lung disease often have to undergo open lung biopsy to establish a final diagnosis. Open lung biopsy is an invasive procedure with major potential complications. Transthoracic lung biopsy (TLB) guided by computed tomography (CT) is a less-invasive well-established procedure in adults.

OBJECTIVE

Detailing the role of low-dose CT-guided TLB in the enhanced diagnosis of chronic lung diseases related to infection in children.

MATERIALS AND METHODS

A group of 11 children (age 8 months to 16 years) underwent CT-guided TLB with a 20-gauge biopsy device. All investigations were done under general anaesthesia on a multidetector CT scanner (SOMATOM Volume Zoom, Siemens, Erlangen, Germany) using a low-dose protocol (single slices, 120 kV, 20 mAs). Specimens were processed by histopathological, bacteriological, and virological techniques.

RESULTS

All biopsies were performed without major complications; one child developed a small pneumothorax that resolved spontaneously. A diagnosis could be obtained in 10 of the 11 patients. Biopsy specimens revealed chronic interstitial alveolitis in ten patients. In five patients Chlamydia pneumoniae PCR was positive, in three Mycoplasma pneumoniae PCR was positive, and in two Cytomegalovirus PCR was positive. The average effective dose was 0.83 mSv.

CONCLUSION

Low-dose CT-guided TLB can be a helpful tool in investigating chronic infectious inflammatory processes in children with minimal radiation exposure. It should be considered prior to any open surgical procedure performed for biopsy alone. In our patient group no significant complication occurred. A disadvantage of the method is that it does not allow smaller airways and vessels to be assessed.

Open lung biopsy in neonatal and paediatric patients referred for extracorporeal membrane oxygenation (ECMO)

BACKGROUND

This study was undertaken to determine the usefulness, safety, and most appropriate timing of open lung biopsy in infants and children considered for and on extracorporeal membrane oxygenation (ECMO) for respiratory failure.

METHODS

A retrospective review of children referred for consideration of and placed on ECMO in our institution in the period 1996-2002.

RESULTS

506 patients were referred, 15 (3%) of whom underwent antemortem open lung biopsy (eight neonatal, four paediatric, and three cardiac patients). In the neonatal group open lung biopsy contributed to clinical decision making in all patients. Four neonates had a fatal lung dysplasia (three alveolar capillary dysplasia and one surfactant protein B deficiency) and treatment was withdrawn. Of the other four neonates, two had pulmonary hypoplasia, one had pulmonary lymphangiectasia, and one had meconium aspiration with mild barotrauma. Treatment was continued in these four patients and two survived. In the paediatric group the biopsies were of clinical relevance in two infants with pertussis who had lung infarction on biopsy in whom treatment was withdrawn. In the other two paediatric patients the biopsies were equivocal, treatment was continued, but both patients died. In the cardiac group, who presented perioperatively with pulmonary hypertension, the biopsies excluded a fatal lung dysplasia and severe pulmonary vascular disease but all three infants died. One patient had non-fatal bleeding complications.

CONCLUSION

Open lung biopsy is clinically most useful when performed to diagnose fatal lung dysplasias in neonates and to confirm the presence of viable lung tissue in patients with acute lung injury due to pertussis infection.

Remodeling of pulmonary arteries in human congenital diaphragmatic hernia with or without extracorporeal membrane oxygenation

PURPOSE

The aim of this study was to describe in detail the perinatal developmental profile of the pulmonary vasculature in congenital diaphragmatic hernia (CDH) and to examine the potential beneficial effects of extracorporeal membrane oxygenation (ECMO) on the vascular morphology. Additionally the authors aimed to identify the differences in pulmonary vascular morphology among CDH cases according to the primary cause of death: either extreme lung hypoplasia (LH) or persistent pulmonary hypertension (PPH).

METHODS

The authors studied autopsy sections from 30 high-risk CDH cases with respect to the pulmonary arteries in relation to gestational age (GA) and ECMO treatment. They were grouped into CDH-I: 20 cases with GA greater than 34 weeks who were not subjected to ECMO and CDH-II: 10 cases with GA greater than 34 weeks, who were subjected to ECMO for an average time of 237 hours. Five age-matched neonates who died from placental insufficiency or birth asphyxia without evidence of lung hypoplasia served as controls (CON). Medial and adventitial thicknesses of pulmonary arteries were measured in lung sections stained with Elastic van Gieson by 2 investigators blinded for the clinical data. Immunohistological staining with anti-alpha-smooth muscle actin (alpha-SMA) was performed to confirm the precise location of the arterial media before morphometry. CDH cases were subgrouped and compared according to the primary cause of death. Unpaired Student t test was used for statistics, with significant P value < or =.05.

RESULTS

In CDH newborns, a significant increase in medial, adventitial, and total wall thickness was found in pulmonary arteries with an external diameter of less than 200 microm as compared with age-matched controls (P<.004, .0001, and .0009, respectively). ECMO-treated CDH newborns showed a significantly thinner arterial adventitia than CDH patients who did not receive this treatment (P<.0001), approaching normal values. However, the medial thickness remained increased. Morphometrically, no significant differences in CDH cases between patients dying of PPH or severe LH could be determined.

CONCLUSIONS

(1) In CDH, there is failure of the normal arterial remodeling processes occurring in the perinatal period. (2) Pulmonary vascular morphology in CDH does not differ between the groups with lung hypoplasia or persistent pulmonary hypertension as primary cause of death. (3) Adventitial thinning of these arteries might be one of the mechanisms by which ECMO alters PPH in CDH cases.