[Congenital pulmonary malformations : Diagnosis and treatment]. / Kongenitale Lungenfehlbildungen : Diagnostik und Therapie.

PERFORMANCE: Congenital pulmonary malformations (CPM) are rare and can be associated with high morbidity. Clinical presentation, diagnostic procedures, imaging, and therapy of CPM are discussed. ACHIEVEMENTS: Today, most CPM can be diagnosed prenatally by ultrasound. Postnatally, respiratory symptoms up to respiratory failure and recurrent lower respiratory tract infection are typical findings. Due to low diagnostic accuracy of chest x­ray in CPM, all children with prenatal diagnosis of CPM or postnatally suspected CPM should undergo cross-sectional imaging. PRACTICAL RECOMMENDATIONS: Based on imaging alone, the various subtypes of CPM cannot be definitively differentiated, which is why histological confirmation remains the gold standard. Surgical resection is the standard of care with minimally invasive procedures increasingly being employed. In certain situations, a watch-and-wait approach is possible.

Infant Pulmonary Function Tests in Children with Airway Anomalies and Correlation with Bronchoscopy Findings.

OBJECTIVES: To evaluate the role infant pulmonary function tests (Tidal Breathing Flow Volume Loops, TBFVL) in children with airway anomalies and to correlate the TBFVL so obtained with bronchoscopy findings. METHODS: In this prospective cohort study, we enrolled children aged 0-2 years with airway anomalies and performed TBFVL and bronchoscopy. The primary outcome measure was graphic pattern of TBFVL in laryngomalacia. Secondary outcome measures were types of TBFVL results in various airway anomalies and controls. RESULTS: Out of 53 children enrolled, 28 (52.3%) had laryngomalacia. Pattern 3 (fluttering of inspiratory limb) was commonest TBFVL pattern in laryngomalacia. Among TBFVL parameters, the ratio of inspiratory time to expiratory time (Ti/Te) and tPTEF/tE was significantly high in children with isolated laryngomalacia compared to controls. At six months of follow-up, TBFVL pattern 1 (normal) became the commonest pattern. CONCLUSION: A particular type of airway anomaly may have a characteristic graphic pattern in TBFVL and TBFVL pattern may indicate improvement in airway anomalies in follow-up.

Congenital pulmonary malformations in children in a pediatric hospital in Peru, 2010-2020.

BACKGROUND: Congenital pulmonary malformations (CPMs) are rare in children. This study aimed to describe the clinical, imaging characteristics, and treatment of patients with this pathology. METHODS: We conducted a descriptive and retrospective study with data from patients with CPMs diagnosed at Instituto Nacional de Salud del Niño-Breña (Lima-Peru), from January 2010 to December 2020. We described CPM clinical and imaging characteristics, type and treatment. RESULTS: The sample was formed of 70 patients. The median age was 29 months (range 15 days-14 years) and the male/female ratio was 1.4. The chest tomography found parenchymal involvement in 50 (71.4%) cases and mixed involvement (parenchymal and vascular) in 18 (25.7%) cases. Congenital malformation of the pulmonary airway was present in 39 (55.7%) cases, followed by bronchogenic cyst in 10 (14.3%), intralobar pulmonary sequestration in 9 (12.9%), and extralobar pulmonary sequestration in 7 (10%). Lobectomy was performed in 61 (87.1%) cases, cystectomy in 5 (7.1%), segmentectomy in 2 (2.9%), and embolization in 2 (2.9%). The most frequent post-operative complication was pneumonia, found in 9 (12.9%) cases. The median hospital stay was 26 days. No patient died during hospitalization. CONCLUSIONS: In our institution, the most frequent CPM was congenital malformation of the pulmonary airway, and lobectomy was the most frequently performed surgical procedure. CPMs represent a diverse group of disorders of lung development with varied imaging patterns and clinical manifestations.

INTRODUCCIÓN: Las malformaciones pulmonares congénitas son poco frecuentes en niños. El objetivo de este estudio fue describir las características clínicas, imagenológicas y tratamiento de los pacientes con esta patología. MÉTODOS: Se llevó a cabo un estudio descriptivo y retrospectivo con datos de los pacientes con malformaciones pulmonares congénitas diagnosticados en el Instituto Nacional de Salud del Niño-Breña (Lima-Perú) entre enero 2010 y diciembre 2020. Se describieron las características clínicas, imagenológicas, el tipo de malformación pulmonar congénita y el tratamiento. RESULTADOS: La muestra fue de 70 pacientes. La mediana de edad fue 29 meses, la relación masculino/femenino fue 1.4. En la tomografía de tórax se encontró compromiso parenquimal en 50 (71.4%) casos, y compromiso mixto (parenquimal y vascular) en 18 (25.7%). La malformación congénita de la vía aérea pulmonar se observó en 39 (55.7%) casos, seguida del quiste broncogénico en 10 (14.3%), secuestro pulmonar intralobar en 9 (12.9%) y secuestro pulmonar extralobar en 7 (10%). La lobectomía fue realizada en 61 (87.1%) casos, la quistectomía en 5 (7.1%), segmentectomía en 2 (2.9%) y embolización en 2 (2.9%). La complicación posquirúrgica más frecuente fue la neumonía en 9 (12.9%) casos. La mediana de estancia hospitalaria fue de 26 días. Ningún paciente falleció durante la hospitalización. CONCLUSIONES: En nuestra institución, la malformación pulmonar congénita más frecuente fue la malformación congénita de la vía aérea pulmonar, y la lobectomía el procedimiento quirúrgico más comúnmente realizado. Las malformaciones pulmonares congénitas representan un grupo diverso de trastornos del desarrollo pulmonar con variados patrones imagenológicos y manifestaciones clínicas.

Congenital Pulmonary Airway Malformations With a Reconsideration and Current Perspective on the Stocker Classification.

Congenital cystic pulmonary lesions (CCPLs) are represented by the following entities: congenital pulmonary airway malformation (CPAM), formerly congenital cystic adenomatoid malformation, extra- and intralobar sequestration (EIS), congenital lobar emphysema (overexpansion), and bronchogenic cyst. The developmental model of CPAM histogenesis by Stocker proposed perturbations designated as CPAM type 0 to type 4 without known or specific pathogenetic mechanisms along the airway from the bronchus to the alveolus. This review highlights mutational events either at the somatic level in KRAS (CPAM types 1 and possibly 3) or germline variants in congenital acinar dysplasia, formerly CPAM type 0, and pleuropulmonary blastoma (PPB), type I, formerly CPAM type 4. The potential for overt malignant progression exists in the case of PPB type I and CPAM type 1 in some cases to well-differentiated mucinous adenocarcinoma. On the other hand, CPAM type 2 is an acquired lesion resulting from interruption in lung development secondary to bronchial atresia. The latter is also regarded as the etiology of EIS whose pathologic features are similar, if not identical, to CPAM type 2. These observations have provided important insights into the pathogenetic mechanisms in the development of the CPAMs since the Stocker classification.

Does Timing of Resection Influence the Presence of Inflammation within Congenital Lung Malformations?

INTRODUCTION: Opinion remains divided on whether to resect an asymptomatic congenital lung malformation (CLM) and on optimal timing of resection. This study aimed to determine if age at resection of CLM correlates with the presence of histological inflammation and/or incidence of prior antibiotic administration for lower respiratory tract infection (LRTI). MATERIALS AND METHODS: A retrospective review of all CLMs resected between 2009 and 2021 was carried out. Data on antenatal detection, incidence of preoperative antibiotic use for LRTI, operative details, and histological reports were analyzed. Fisher's exact test and logistic regression were used to look for correlation between age at resection and (1) histological inflammation and/or (2) preoperative LRTI. RESULTS: A total of 102 patients underwent resection at age 14 months (interquartile range: 6-23). Eighty percent of children were asymptomatic in the neonatal period and 22% of these went on to develop a respiratory symptom. In total, 59% of specimens had histological evidence of inflammation, with a significantly higher rate of inflammation after 10 months of age (71 vs. 35%; p = 0.0012). Logistic regression showed there was a positive correlation between age at resection and treatment for previous LRTI (p = 0.020). CONCLUSION: Detection rates of inflammation in specimens resected after 10 months of age are double the rates of those resected prior to 10 months. Delaying resection of CLMs showed a higher frequency of treatment of LRTI. Earlier resection may therefore be advantageous for centers pursuing a resection strategy for asymptomatic lesions.

Management of Congenital Lung Malformations.

Congenital lung malformations represent a spectrum of lesions, each with a distinct cause and tailored clinical approach. This article will focus on the following malformations: congenital pulmonary airway malformations, formally known as congenital cystic adenomatoid malformations, bronchopulmonary sequestration, congenital lobar emphysema, and bronchogenic cyst. Each of these malformations will be defined and examined from an embryologic, pathophysiologic, and clinical management perspective unique to that specific lesion. A review of current recommendations in both medical and surgical management of these lesions will be discussed as well as widely accepted treatment algorithms.

Congenital lung malformations: Dysregulated lung developmental processes and altered signaling pathways.

Congenital lung malformations comprise a diverse group of anomalies including congenital pulmonary airway malformation (CPAM, previously known as congenital cystic adenomatoid malformation or CCAM), bronchopulmonary sequestration (BPS), congenital lobar emphysema (CLE), bronchogenic cysts, and hybrid lesions. Little is known about the signaling pathways that underlie the pathophysiology of these lesions and the processes that may promote their malignant transformation. In the last decade, the use of transgenic/knockout animal models and the implementation of next generation sequencing on surgical lung specimens have increased our knowledge on the pathophysiology of these lesions. Herein, we provide an overview of normal lung development in humans and rodents, and we discuss the current state of knowledge on the pathophysiology and molecular pathways that are altered in each congenital lung malformation.

Large congenital pulmonary airway malformation with mucinous cell clusters - a case report.

We report the clinical case of a 38 weeks gestational age neonate, antenatally diagnosed with a left large macrocystic pulmonary malformation conditioning dextrocardia. At birth, he presented with respiratory distress requiring non-invasive ventilation with high-flow nasal cannula (HFNC). A left inferior lobectomy was performed via thoracotomy on day 21 of life. Histological features of the lesion were compatible with congenital pulmonary airway malformation (CPAM) type I with muci- nous cell clusters. No surgical complications were reported and the neonate was discharged six days after surgery. Follow-up two months after surgery was unremarkable.

Establishment of a multidisciplinary fetal center streamlines approach for congenital lung malformations.

PURPOSE: Fetuses with a diagnosis of congenital lung malformations (CLM) on prenatal imaging are commonly referred to a multi-disciplinary specialty team for prenatal assessment and postnatal management. The net effect of such services is broadly stated to improve the outcomes of affected newborns. However, these claims are relatively unsubstantiated. METHODS: After IRB approval, a retrospective review of children diagnosed with CLM from 2008 to 2018 and referred to a large urban children's hospital was performed. A comparison was performed between prenatally diagnosed patients having a multi-disciplinary fetal center evaluation (FC) and prenatally diagnosed patients who did not receive a referral or were seen prior to the establishment of the center (NON-FC). RESULTS: Eighty-eight live-born patients with a prenatal diagnosis of CLM were identified, with 49 in the FC group and 39 NON-FC. Thirty-four (63%) and 23 (59%) patients underwent operative resection of CLM, respectively. FC patients presented earlier at first postnatal follow-up (42 vs. 145 days, p = .03), had fewer preoperative office visits (2.1 vs. 3.4, p = .0003), received fewer preoperative chest radiographs (0.5 vs. 1.3; p = .002) and chest computed tomography (0.9 vs. 1.4; p = .001), and had fewer preoperative pneumonias (0 vs. 17.4%; p = .02) compared to their NON-FC counterparts. FC patients were also more likely to undergo resection at an earlier age (217 vs. 481 days, p = .003) and were more likely to undergo a minimally invasive resection (75% vs. 39.1%, p = .015). There were no differences in post-operative outcomes between the two groups. CONCLUSION: Children with a prenatal diagnosis of CLM appear to benefit from an organized multi-specialty team approach in several impactful parameters. Hospital systems and providers that invest in similar strategies are likely to achieve improved outcomes in the care of newborns prenatally diagnosed with a CLM.

Trastorns respiratoris obstructius del son: necessitat d’un enfocament precoç i interdisciplinari / Trastornos respiratorios obstructivos del sueño: necesidad de un enfoque precoz e interdisciplinario / Obstructive sleep-disordered breathing: the need for an early and interdisciplinary approach

Fonament. Els trastorns respiratoris obstructius del son (TROS) són un gradient de patologies extremament infradiagnosticades malgrat la seva alta prevalença, en especial als països industrialitzats. La necessitat d’una deteccióprecoç i d’un tractament en equip interdisciplinari han fet que el nombre de publicacions de totes les especialitatsrelacionades no hagi parat de créixer en l’última dècada.És per això que creiem necessària una revisió de la bibliografia publicada fins al moment, que ens permeti tenir unavisió més global i donar recomanacions a l’hora de diagnosticar i tractar aquests trastorns.Objectiu. Conèixer la fisiopatologia, els signes i símptomes més característics, i les tècniques de diagnòstic, prevenció i tractament descrits fins al moment en relació amb els TROS.Mètode. Revisió de la bibliografia internacional publicada per totes les especialitats involucrades, fins al 2020.Resultats. Existeix una àmplia bibliografia que tracta sobre la fisiopatologia, el diagnòstic i el tractament des del punt de vista de les diferents especialitats. Encara avui és un tema d’actualitat científica bastant desconegut i malauradament poc present en la pràctica pediàtrica diària.Conclusions. Els trastorns respiratoris obstructius del sontenen un impacte directe o indirecte en l’evolució correcta dels infants. La col·laboració de totes les especialitats pediàtriques per prevenir-los, detectar-los i tractar-los abans dels 5 anys és imprescindible. (AU)

Fundamento. Los trastornos respiratorios obstructivos del sueño (TROS) son un gradiente de patologías extremadamente infradiagnosticadas a pesar de su alta prevalencia, especialmente en lospaíses industrializados. La necesidad de una detección precoz y un tratamiento en equipo interdisciplinar han hecho que el número de publicaciones de todas las especialidades relacionadas no haya parado de crecer en la última década. Por ello, creemos necesaria una revisión de la bibliografía publicada hasta el momento, que nos permita tener una visión más global y dar recomendaciones a la hora de diagnosticar y tratar estos trastornos.Objetivo. Conocer la fisiopatología, los signos y síntomas más característicos, y las técnicas de diagnóstico, prevención y tratamiento descritas hasta el momento en relación con los TROS.Método. Revisión de la bibliografía internacional publicada por todas las especialidades involucradas, hasta 2020.Resultados. Existe una amplia bibliografía sobre la fisiopatología,diagnóstico y tratamiento, desde el punto de vista de las diferentes especialidades. Aún hoy, es un tema de actualidad científica bastante desconocido y desgraciadamente poco presente en la práctica pediátrica diaria.Conclusiones. Los trastornos respiratorios obstructivos del sueño tienen un impacto directo o indirecto en la correcta evolución de los niños. La colaboración de todas las especialidades pediátricas para prevenirlos, detectarlos y tratarlos antes de los 5 años es imprescindible. (AU)

Background. Obstructive Sleep-disordered Breathing (SDB) includes a spectrum of extremely underdiagnosed sleep disorders despite their high prevalence, particularly in industrialized countries.The need for early detection and interdisciplinary treatment has resulted in a significant increase in the number of published papers from all related specialties over the last decade. For this reason, a review of the literature published so far may be necessary to provide a more comprehensive perspective and recommendations for the diagnosis and treatment of these disorders.Objective. To describe the pathophysiology, the most characteristic signs and symptoms, and the diagnosis, prevention and treatment techniques described so far related to SDB.Method. Review of the published literature on the subject at an international level, from the point of view of all the specialties involved, until 2020.Results. There is extensive scientific literature about the pathophysiology, diagnosis, and treatment of SDB. It is still a subject of active scientific discussion, but with little knowledge and awareness in the daily paediatric practice.Conclusions. Obstructive sleep-disordered breathing may have a direct or indirect impact on the growth and development of dren. A multidisciplinary approach is critical to prevent, diagnose and treat SDB before the age of five. (AU)

Congenital bronchial atresia complicated by a lung abscess due to Aspergillus fumigatus: a case report.

BACKGROUND: Congenital bronchial atresia is a rare pulmonary abnormality characterized by the disrupted communication between the central and the peripheral bronchus and is typically asymptomatic. Although it can be symptomatic especially when infections occur in the involved areas, fungal infections are rare complications in patients with bronchial atresia. We report a case of congenital bronchial atresia complicated by a fungal infection. CASE PRESENTATION: A 30-year-old man with no previous history of immune dysfunction was brought to a nearby hospital and diagnosed with a left lung abscess. Although antimicrobial treatment was administered, it was ineffective, and he was transferred to our hospital. Since diagnostic imaging findings and bronchoscopy suggested congenital bronchial atresia and a fungal infection, he was treated with voriconazole and surgical resection was subsequently performed. A tissue culture detected Aspergillus fumigatus and histopathological findings were compatible with bronchial atresia. After discharge, he remained well and voriconazole was discontinued 5 months after the initiation of therapy. CONCLUSION: Bronchial atresia is a rare disease that is seldom complicated by a fungal infection, which is also a rare complication; however, physicians should consider fungal infections in patients with bronchial atresia who present with infections resistant to antimicrobial treatment.

Ultrasound detected prenatal hyperechoic lung lesions and concordance with postnatal findings: A common aspect for multiple diagnoses.

OBJECTIVE: Hyperechoic lung lesions are largely detected prenatally but their underlying etiology is still poorly defined. The aim of the study was to determine the concordance between pre and postnatal diagnosis of hyperechoic lung lesions. METHODS: Prenatal ultrasound (US) evaluation was performed by a fetal medicine specialist. Postnatal diagnosis was based on CT-scan. Pre- and postnatal features were retrieved from medical charts. RESULTS: Seventy five patients were included from January 2009 to December 2018. Main prenatal diagnoses were bronchopulmonary sequestrations (BPS) (n = 24%-32%), pulmonary cystic malformations (PCM) (n = 19%-25%), congenital lobar emphysemas (CLE) (n = 15%-20%). Mediastinal shift was observed in 18 cases (24%). The prenatal detection of a systemic arterial supply had a diagnostic accuracy of 90%, while the prenatal detection of a cystic component had a diagnostic accuracy of 76.5%. All 16 neonates with prenatal isolated mediastinal shift were asymptomatic at birth. Seven neonates showed respiratory distress that was not predicted prenatally. CONCLUSIONS: Hyperechoic lung malformations reflect a heterogeneous group of lesions with a good concordance for bronchopulmonary sequestration, but not a satisfying prediction for cystic lesions.

Impact of Additional Anomalies on Postnatal Outcomes in Congenital Lung Malformations.

BACKGROUND: Approximately 20% of fetuses diagnosed with congenital lung malformations (CLMs) are found to have additional anomalies. We aim to determine if additional anomalies have an impact on postnatal outcomes for patients with CLMs. METHODS: After institutional review board approval, we performed a retrospective review of live-born patients with CLMs from 2008 to 2018. All patients were prenatally diagnosed with CLMs. Clinical information pertaining to additional congenital anomalies and outcomes was collected from the electronic health record and analyzed. RESULTS: Of the 88 patients who had a prenatal diagnosis of CLMs, 20.5% had additional anomalies. Ten of the 18 patients (56%) were considered to have a major anomaly in addition to CLMs. Outcomes for patients electing nonoperative management of CLMs were similar between those with and without an additional anomaly. Although patients with an additional anomaly were more likely to have perinatal respiratory complications (44% versus 17%, P = 0.03), the number of preoperative clinic and emergency department visits, age at surgery, minimally invasive approach to surgical resection of CLM, estimated blood loss, length of hospital stay, intubation, duration of intubation, 30-day postoperative complications, and long term sequelae were not statistically different. This held true when stratified for major versus minor anomalies. CONCLUSIONS: Twenty percent of fetuses diagnosed with CLM in our population have additional anomalies. Newborns with additional anomalies have a higher risk of pre-excision pulmonary complications. However, the overall outcomes of all patients with CLMs are similar.

Prenatal Imaging to Predict Need for Urgent Perinatal Surgery in Congenital Lung Lesions.

BACKGROUND: Congenital lung malformations (CLMs) have a variable natural history: some patients require urgent perinatal surgical intervention (UPSI) and others remain asymptomatic. These lesions have potential growth until 26-28 wk gestation. CLM volume ratio (CVR) has been shown to predict the risk of hydrops in CLMs. However, no criteria exist to delineate lesions requiring urgent surgical intervention in the perinatal period. Our goal was to determine prenatal diagnostic features that predict the need for UPSI in patients diagnosed with CLM. METHODS: Records and imaging features of all fetuses evaluated by our fetal center between May 2015 and December 2018 were retrospectively reviewed. Data included demographics, fetal ultrasound and magnetic resonance imaging, CVR, surgical treatment, and outcome. Features were analyzed for their ability to predict the need for UPSI. RESULTS: Sixty-four patients were referred for CLM, with 48 patients serially followed. Nine (18.8%) patients were followed nonoperatively, 35 (72.9%) underwent resection, and four (8.3%) were lost to follow-up. Of the patients who underwent resection, 24 (68.5%) were electively resected and 11 were urgently resected. Five (14.3%) patients underwent ex utero intrapartum treatment resection, and six (17.1%) were urgently resected for symptomatic CLM. There were no cases of UPSI with final CVR <1.1. Of the patients with final CVR 1.1-1.7, 43% required urgent resection. CVR ≥1.1 has 100% sensitivity and 87.8% specificity to predict patients requiring UPSI (area under the curve of 0.98). CONCLUSIONS: A final CVR ≥1.1 is highly predictive for UPSI. Patients with a final CVR ≥1.1 should be referred for delivery at centers with pediatric surgeons equipped for potential UPSI for CLM.

Etiologies of apnea of infancy.

BACKGROUND: To date there are limited data in the literature to guide the initial evaluation for etiologies of apnea in full-term infants born at greater than or equal to 37 weeks conceptional age (apnea of infancy [AOI]). Pediatricians and pediatric pulmonologists are left to pursue a broad, rather than targeted and a stepwise approach to begin diagnostic evaluation. METHODS: We performed a retrospective chart review of 101 symptomatic full-term infants (age under 12 months) diagnosed with apnea with an inpatient multichannel pneumogram (six channels) or a fully attended overnight pediatric polysomnogram in our outpatient sleep center accredited by American Academy of Sleep Medicine (AASM), scored using the standards set forth by the AASM. The infant was diagnosed as having AOI if the apnea hypopnea index (AHI) was greater than 1 (AHI is defined as the number of apnea and hypopnea events per hour of sleep). The final diagnosis/etiology was determined based on physician clinical assessment and work up. We then determined the frequency for each diagnosis. RESULTS: We found that the three most common etiologies were gastroesophageal reflux disease (GERD) (48/101), upper airway abnormalities/obstruction (37/101), and neurological diseases (19/101). There were significant numbers of infants with multiple etiologies for AOI. CONCLUSION: Based on the frequencies obtained, pediatric practitioners caring for full-term infants with apnea of unknown etiology are advised to begin with evaluation of more likely causes such as GERD and upper airway abnormalities/obstruction before evaluating for less common causes.

Recurrent Peumonia in an Infant With an Esophageal Lung.

Esophageal lung is a rare variety of communicating bronchopulmonary foregut malformation with anomaolous communication between an isolated portion of respiratory tissue and esophagus. Children present in early life with recurrent cough and pneumonia. Majority of the reported cases are associated with other anomalies like tracheoesophageal fistula. We report a case of a 7-month-old girl with right sided esophageal lung who was misdiagnosed as dextrocardia with right sided pneumonitis.

Development of a multi-institutional registry for children with operative congenital lung malformations.

INTRODUCTION: The purpose of this study was to develop a multi-institutional registry to characterize the demographics, management, and outcomes of a contemporary cohort of children undergoing congenital lung malformation (CLM) resection. METHODS: After central reliance IRB approval, a web-based, secure database was created to capture retrospective cohort data on pathologically-confirmed CLMs performed between 2009 and 2015 within a multi-institutional research collaborative. RESULTS: Eleven children's hospitals contributed 506 patients. Among 344 prenatally diagnosed lesions, the congenital pulmonary airway malformation volume ratio was measured in 49.1%, and fetal MRI was performed in 34.3%. One hundred thirty-four (26.7%) children had respiratory symptoms at birth. Fifty-eight (11.6%) underwent neonatal resection, 322 (64.1%) had surgery at 1-12 months, and 122 (24.3%) had operations after 12 months. The median age at resection was 6.7 months (interquartile range, 3.6-11.4). Among 230 elective lobectomies performed in asymptomatic patients, thoracoscopy was successfully utilized in 102 (44.3%), but there was substantial variation across centers. The most common lesions were congenital pulmonary airway malformation (n = 234, 47.3%) and intralobar bronchopulmonary sequestration (n = 106, 21.4%). CONCLUSION: This multicenter cohort study on operative CLMs highlights marked disease heterogeneity and substantial practice variation in preoperative evaluation and operative management. Future registry studies are planned to help establish evidence-based guidelines to optimize the care of these patients. LEVEL OF EVIDENCE: Level II.