Primary lymphatic dysplasia in children: chylothorax, chylous ascites, and generalized lymphatic dysplasia

Impact of High Fat Diet and Bolus Feeding on Chyle Accumulation in a Mouse Model of Generalized Lymphatic Anomaly

Background: Generalized lymphatic anomalies (GLA) are complex vessel malformations that can impair lymphatic function. Potential GLA complications include lipid-rich lymph in the thoracic space or peritoneal cavity, respectively chylothorax and chylous ascites. To reduce the potential for chyle accumulation, GLA patients limit dietary fats. We hypothesized that dietary fatty acid composition impacts the potential for lymphatic dysfunction and chyle accumulation in GLA. Methods and Results: Adipose-specific overexpression of lymphatic growth factors has demonstrated lethal chylothorax in mice. Here, we utilized mice with inducible adipocyte overexpression of vascular endothelial growth factor-D (VD mice) to mimic lymphatic proliferation in GLA and assessed the incidence of chyle accumulation on a mixed high fat diet (HFD), high saturated fat diet (HSFD), or high unsaturated fat diet (HUSFD). Lipid transport was assessed by uptake rates of bolus oral triglyceride load and mesenteric fat analysis. Lymphatic expansion and inflammation were determined by whole mount immunofluorescence and gene expression. Body composition was assessed by MRI. HSFD 2-month wildtype groups resulted in an increase in TNF-α, IL-6, and IL-10 expression compared with chow-fed controls. The chyle accumulation incidence was highest in HFD-fed mice compared with either HSFD or HUSFD. Strikingly, increased mortality was observed irrespective of which high fat diet was consumed after administration of a bolus lipid load. Conclusion: Chronic HFD increases risk of chyle accumulation, however increased mortality was driven particularly by a bolus lipid load in VD mice. These findings suggest that although chronic HFD increases chyle accumulation risk, a single large meal feeding may increase risk of lethal chylothorax instances for GLA patients.

Abnormal pulmonary lymphatic flow in patients with paediatric pulmonary lymphatic disorders: Diagnosis and treatment

Pulmonary lymphatic disorders are characterized by the presence of the abnormal lymphatic tissues in the thoracic cavity, presenting clinically as chylothorax, chylopericardium, chyloptysis, interstitial lung disease and plastic bronchitis. These conditions include: neonatal chylothorax, cardiac and non-cardiac plastic bronchitis, non-traumatic chylothorax, post congenital cardiac surgery chylothorax and complex lymphatic malformations. Recently developed lymphatic imaging techniques, such as intranodal lymphangiography and dynamic contrast enhanced magnetic resonance lymphangiography demonstrated abnormal pulmonary lymphatic flow from thoracic duct into pulmonary parenchyma as a pathophysiological mechanism of these diseases. Novel minimally invasive lymphatic interventions, such as thoracic duct embolization, interstitial lymphatic embolization and surgical lympho-venous anastomosis, provide an effective treatment of these conditions.

Recognition of Neonatal Lymphatic Flow Disorder: Fetal MR Findings and Postnatal MR Lymphangiogram Correlation

RATIONALE AND OBJECTIVES

This study aimed to describe prenatal and postnatal imaging features and outcomes of neonates with neonatal lymphatic disorders (NLDs).

MATERIALS AND METHODS

An institutional review board-approved search of the radiology database for patients with NLD identified five patients. Inclusion criteria include prenatal imaging (fetal magnetic resonance [MR] imaging and ultrasound) and postnatal three-dimensional T2 Sampling Perfection with Application optimized Contrasts using different flip angle Evolution (SPACE) and dynamic contrast-enhanced MR lymphangiography within 6 months of life. Chart review was undertaken to evaluate morbidity and mortality.

RESULTS

Prenatal finding of "nutmeg lung" or fetal pulmonary lymphatic disorder was identified in all five patients on fetal MR imaging, and in four of five patients on fetal ultrasound. Postnatal dynamic contrast-enhanced MR lymphangiography demonstrated abnormal lymphatic flow to the lungs in four of five patients, but absent in the single patient with coexisting hypoplastic left heart syndrome (HLHS). Dermal backflow was seen in one patient, also the only patient with prenatal body wall edema. Three patients with lymphatic flow to the lungs only were classified as neonatal chylothorax. The patient with dermal backflow and perfusion to the lungs was diagnosed with central lymphatic flow disorder (CLFD). The HLHS patient with normal lymphatic perfusion maintained the HLHS diagnosis. Of the five patients, the patient with CLFD and the one with HLHS expired because of respiratory distress.

CONCLUSIONS

NLDs can be recognized on prenatal and postnatal imaging and may be primary, as in neonatal chylothorax or CLFD, or secondary. In this small series, "nutmeg lung" was present in all patients. Prenatal imaging demonstrates that body wall edema may correlate with postnatal dermal backflow, which, in our small cohort, carried a poor prognosis.

Near-Infrared Fluorescence Lymphatic Imaging of a Toddler With Congenital Lymphedema

Primary lymphedema in the pediatric population remains poorly diagnosed and misunderstood due to a lack of information on the causation and underlying anatomy of the lymphatic system. Consequently, therapeutic protocols for pediatric patients remain sparse and with little evidence to support them. In an effort to better understand the causation of primary pediatric lymphedema and to better inform clinical care, we report the use of near-infrared fluorescence lymphatic imaging on the extremities of an alert, 21-month-old boy who presented with unilateral right arm and hand lymphedema at birth. The imaging results indicated an intact, apparently normal lymphatic anatomy with no obvious malformation, but with decreased lymphatic contractile function of the affected upper extremity relative to the contralateral and lower extremities. We hypothesized that the lack of contraction of the lymphatic vessels rather than an anatomic malformation was the source of the unilateral extremity swelling, and that compression and manual lymphatic drainage could be effective treatments.

Twin infant with lymphatic dysplasia diagnosed with Noonan syndrome by molecular genetic testing

Noonan Syndrome is an autosomal dominant disorder characterized by short stature, congenital heart defects, developmental delay, dysmorphic facial features and occasional lymphatic dysplasias. The features of Noonan Syndrome change with age and have variable expression. The diagnosis has historically been based on clinical grounds. We describe a child that was born with congenital refractory chylothorax and subcutaneous edema suspected to be secondary to pulmonary lymphangiectasis. The infant died of respiratory failure and anasarca at 80 days. The autopsy confirmed lymphatic dysplasia in lungs and mesentery. The baby had no dysmorphic facial features and was diagnosed postmortem with Noonan syndrome by genomic DNA sequence analysis as he had a heterozygous mutation for G503R in the PTPN11 gene.

Fetal chylous ascites may redevelop only after birth

Congenital chylous ascites is a rare condition. We describe a case in which fetal ascites was found on a routine antenatal ultrasound, with all abnormalities resolving by 36 weeks’ gestation. No investigations or treatment for the ascites was undertaken after the baby´s birth. At the age of 3 months, when the baby underwent surgery for bilateral inguinal hernias and hydrocele, milky fluid was drained from the hernia sac. Laboratory and ultrasound investigations confirmed the presence of a significant amount of chyle in the peritoneal cavity. Congenital chylous ascites was treated by means of a diet based on medium chain triglycerides. By the age of 6 months, the fluid in the abdomen had resolved. However, it partly reappeared once a normal mixed diet was allowed. A minimal amount of fluid in the lower abdominal cavity was consistently found up to the age of 22 months. The fluid had finally disappeared by the age of 30 months when the child was generally in good health and developing normally. We conclude that congenital chylous ascites may be diagnosed prior to birth but may become more clinically significant only after birth, when its severity is enhanced by feedings of milk containing long chain fats. We recommend a thorough postnatal evaluation and follow-up in all infants diagnosed with fetal ascites, so that appropriate and timely management decisions can be made, if the chylous origin of the ascites is confirmed.

Congenital chylothorax: associations and neonatal outcomes

AIM

Congenital chylothorax is a rare but significant neonatal entity with major morbidity and mortality. The study aims to describe the related associations, management and outcomes of this condition in neonates.

METHODS

This is a retrospective case series of all cases of congenital chylothorax admitted to a tertiary neonatal centre in the last 15 years.

RESULTS

Ten cases of congenital chylothorax were identified. Eight infants were diagnosed antenatally and three infants had antenatal pleural drainage. Most infants were ventilated at birth and required immediate pleurocentesis. Post-natal management included drainage of fluid, ventilation, albumin replacement, octreotide and dietary modification with medium-chain triglyceride-enriched formula. Five infants had chromosomal aberrations identified, while a further two had dysmorphic features not substantiated with routine genetic testing. Noonan's syndrome was the single most common underlying genetic diagnosis. Associated anomalies and malformations were present in 80% of the cohort. There were two deaths in the series, both in infants with multiple co-morbidities.

CONCLUSIONS

Congenital chylothorax is a rare condition with overall prevalence of less than a case per year in our experience. Majority of infants had associated chromosomal anomalies and significant co-morbidities needing prolonged intensive care.

The prognostic factors and the outcome of primary isolated fetal ascites

PURPOSE

The purpose of the present study was to evaluate the prognostic factors and review the outcome of primary isolated fetal ascites.

METHODS

A retrospective cohort study was conducted for fetuses with primary isolated ascites with a prenatal diagnosis between 1994 and 2009. The patients were divided into the favorable group (Group I) whose ascites were resolved by medical treatment alone and an unfavorable group (Group II) who required surgical intervention after birth due to refractory ascites.

RESULTS

There were seven patients in Group I and five patients in Group II. Six of seven patients who developed ascites after 30 weeks' gestation were categorized in Group I, and four of five infants who developed ascites before 30 weeks' gestation were categorized in Group II. There was a negative correlation between the gestational age at diagnosis and the severity of the fetal abdominal distention. In Group II, the ascites resolved in two cases and was reaccommodated in another two cases after surgery. An infant with trisomy 21 received continuous drainage and eventually died of infection.

CONCLUSIONS

The prognosis of primary isolated fetal ascites can be predicted based on the gestational age at diagnosis and the severity of the fetal abdominal distention.

Therapeutic management of neonatal chylous ascites: report of a case and review of the literature

Congenital chylous ascites is a rare condition seen in the neonatal period and the data on pathogenesis and treatment modalities are limited. In this article, we report a case of neonate with chylous ascites and review the therapeutic management procedures on chylous ascites in childhood. We present our experience in the diagnosis and treatment of this condition.

CONCLUSION

Medium-chain triglycerides (MCT)-based diet can be tried as a first option in chylous ascites treatment. In resistant or unresponsive cases, somatostatin along with TPN can have use in closing the lymphatic leakage or relieving the symptoms effectively and rapidly. Conventional regimens including enteral feeding with MCT-based formula can then be re-administered as a maintenance treatment after reduction of lymph flow with the use of total parenteral nutrition (TPN) and somatostatin infusion combination. Patient-specific approach should be attempted for chylous ascites caused by various disorders and started as soon as possible.

The use of fat-free human milk in infants with chylous pleural effusion

OBJECTIVE

The purpose of this study is to describe the processing of human milk to remove its fat content and its use in seven infants with chylothorax.

STUDY DESIGN

The mother's milk was centrifuged at 3000 r.p.m. for 15 min at 2 degrees C. After centrifugation, the milk separated into a solidified-fat top layer and a lower liquid portion. The fat-free liquid portion was then poured into collection cups and frozen for the patient's use at a later date. A sample of the mother's milk before and after processing was stored and analyzed for fat, sodium, potassium, calcium and zinc.

RESULTS

The mean fat removed was 5+/-1 g/dl (mean+/-s.d.), which was the same as the pre-fat content of the mother's milk. Seven infants with chylous pleural effusions used the fat-free human milk. All infants started on the fat-free milk after a month of age for an average of 16 days duration (7 to 34 days range). There was no reaccumulation of the chylous pleural effusions with the use of the fat-free mother's milk. Mother's milk electrolytes were similar before and after processing.

CONCLUSION

Fat-free human milk may be an important additional dietary therapy for infants with chylothorax and may add the immunologic properties of human milk that other feedings cannot provide.

Congenital chylothorax treated with octreotide

Congenital chylothorax is the accumulation of lymphatic fluid within the pleural space. Cases unresponsive to conservative management usually require surgery. Octreotide has been used successfully to treat post-traumatic chylothoraces in the pediatric and adult population. Its exact mode of action is uncertain but it is believed to reduce lymphatic drainage by a direct action on splanchnic lymph flow. We report a case of congenital chylothorax where surgery was avoided with the compassionate trial of the somatostatin analogue, octreotide. A 33 week gestation female infant, born with the presence of large bilateral pleural effusion, was unresponsive to conservative management. Octreotide was commenced on day 15, with 10 days of an octreotide infusion, initially 0.5 microg/kg per hour and increased daily by 1 microg/kg per hour to 10 microg/kg per hour. Treatment was associated with prompt respiratory improvement prior to cessation of pleural drainage over the 10 day. She remains well at 6 months of age. Further studies are required to ascertain its true value in congenital chylothorax.

Etiology of chylothorax in 203 patients

OBJECTIVES

To characterize the etiology of chylothorax in patients encountered at a single tertiary referral center and to compare the findings with those from previous studies.

PATIENTS AND METHODS

The medical records of all patients with chylothorax seen at the Mayo Clinic in Rochester, Minn, over a 21-year period, from January 1, 1980, to December 31, 2000, were retrospectively reviewed to ascertain the underlying cause of their condition.

RESULTS

We identified 203 patients with chylothorax; 92 were females (male-female ratio, 1.21). The median age was 54.5 years (range, 21 weeks' gestation to 93 years). Dyspnea, the most common presenting symptom, occurred in 98 (56.6%) of 173 patients in whom initial symptoms were recorded, whereas 64 (37.0%) had no respiratory symptoms. Median duration of symptoms before diagnosis was 7.5 weeks (range, 1 day to 4.5 years). Causes of chylothorax included surgery or trauma in 101 patients (49.8%), various medical conditions in 89 (43.8%), and unknown in 13 (6.4%). Among surgical procedures, esophagectomy (29 patients) and surgery for congenital heart disease (28 patients) were the most common causes of chylothorax. Among medical conditions, lymphoma (23 patients), lymphatic disorders (19 patients), and chylous ascites (16 patients) were the most common causes.

CONCLUSIONS

Chylothorax has numerous causes. In contrast to previous studies, surgery or trauma was the most common cause of chylothorax at our institution, accounting for nearly 50% of cases. Lymphoma and other malignancies caused chylothorax in only 16.7% of cases. These numbers are possibly related to the high volume of cardiothoracic surgical procedures performed at our tertiary referral center.

Octreotide in the treatment of congenital chylothorax

Congenital chylothorax is the accumulation of lymphatic fluid within the pleural space. Cases unresponsive to conservative management usually require surgery. Octreotide has been used successfully to treat post-traumatic chylothoraces in the paediatric and adult population. Its exact mode of action is uncertain but it is believed to reduce lymphatic drainage by a direct action on splanchnic lymph flow. We report a case of congenital chylothorax where surgery was avoided with the compassionate trial of the somatostatin analogue, octreotide. Treatment was associated with prompt respiratory improvement prior to cessation of pleural drainage. Further studies are required to ascertain its true value in congenital chylothorax.

Neonatal chylous ascites--report of three cases and review of the literature

Three cases of neonatal chylous ascites (CCA) were managed in the neonatal unit, University Hospital, Kuala Lumpur, over the past 9 years. Fetal ascites and polyhydramnios were the sole abnormalities detected in all three babies by antenatal ultrasonography. They were born at 36 weeks' gestation and their birth weights ranged from 3.0 kg to 3.8 kg. All three infants had abdominal distension at birth. Milky ascitic fluid was obtained after starting enteral feedings. Analysis of the ascitic fluid revealed a raised white blood cell count (predominantly lymphocytic) and triglycerides (1.4 - 3.8 mmol/l), cholesterol (1.6 - 2.8 mmol/l), and protein levels (25 - 41 g/l). Conservative management with skimmed milk and medium-chain triglycerides in one infant and Pregestimil in another was instituted. these two infants with CCA were clinically normal when reviewed at 19 months and 3.5 years of age. The third infant had a gut malrotation and associated pyloric septum; he died from complications of a laparotomy. The literature on this rare condition is reviewed.

Successful treatment of congenital chylous ascites with a somatostatin analogue

Congenital chylous ascites (CCA) results from maldevelopment of the intra-abdominal lymphatic system. Newborns present with respiratory distress and abdominal distention. Medical treatment of CCA is often prolonged. A newborn with CCA was treated with octreotide, a somatostatin analogue, resulting in rapid and complete resolution of the ascites.

Posttraumatic chylous ascites in a child: recognition and management of an unusual condition

Chylous ascites is an extremely rare and often unrecognized complication of abdominal trauma in children. The management of this condition has traditionally been nonsurgical, but the success rate with nonoperative treatment is not always satisfactory. A case of posttraumatic chylous ascites in an abused toddler is presented, with emphasis on the diagnosis and treatment of this rare disorder.

Diffuse pulmonary lymphangiomatosis

Angiomatous lesions of the lung are uncommon and not well characterized. We describe nine cases of a distinct lymphatic vascular lesion that we have termed "diffuse pulmonary lymphangiomatosis." Extrathoracic lymphangiomatous lesions were not identified. The patients comprised seven males and two females with a mean age at presentation of 10 years (age range, 1 month to 33 years). Six patients were younger than 10 years of age. Symptoms included "wheezing" or "asthma" (44%) and dyspnea (22%) present for 3 months to 20 years. Chest radiographs showed bilateral interstitial infiltrates, often greatest in the lower lobes. Pleural or pericardial effusions were present or developed in six patients. Pulmonary function tests showed in two patients and mixed obstruction and restriction in five patients. Open lung biopsies (nine patients) and autopsy (one patient) showed anastomosing endothelial lined spaces along pulmonary lymphatic routes (especially pleural and interlobular septal) accompanied by asymmetrically spaced bundles of spindle cells, which were prominent in six cases. Hemosiderin deposition often was present in the spindle cell areas and in the adjacent lung. The lining cells were positive for factor VIII-related antigen (eight cases) and Ulex europaeus I agglutinin (four cases). The spindle cells were reactive with antibodies to vimentin (nine cases), desmin (six cases), actin (seven cases), progesterone receptor (seven cases), and proliferating cell nuclear antigen (one case); they were negative for estrogen receptor (seven cases), keratin, (eight cases), and HMB-45 (eight cases). Diffuse pulmonary lymphangiomatosis was progressive in eight cases and was most aggressive in the youngest children. Two of the children have died, one of pulmonary hemorrhage and the other after heart-lung transplantation. Diffuse pulmonary lymphangiomatosis is distinct from lymphangiectasis, lymphangioleiomyomatosis, pulmonary capillary hemangiomatosis, Kaposi's sarcoma, and kaposiform hemangioendothelioma. Due to its distribution and histology, a lymphatic origin of the lesion is favored.

Chylous ascites: total parenteral nutrition as primary therapeutic modality

A female infant with Down syndrome and congenital chylous ascites presented at birth with respiratory distress secondary to marked abdominal distension. Total parenteral nutrition (TPN) and paracentesis were the primary therapeutic modality. On hyperalimentation, however, ascites initially recurred, requiring additional paracenteses to improve respiratory distress. The chylous ascites, lymphopenia and hypoalbuminemia were relieved after 10 weeks of TPN administration. We recommend a long-term course (10 weeks) of TPN before an exploratory laparatomy and possible surgical intervention are considered.

Unusual diffuse pulmonary lymphatic proliferation in a young boy

We describe a 4-year-old boy who died of an unusual generalized pulmonary lymphatic proliferation. His condition cannot clearly be categorized with any of the previously described pulmonary lymphatic disorders.