Developmental Disorders of the Lymphatics

An information blog for disorders of the lymphatics. For all articles, please click on "Archives" - Due to spammers, I will no longer allow comments, sorry.

Wednesday, June 28, 2006

Diagnosis and management of primary chylous ascites.

Campisi C, Bellini C, Eretta C, Zilli A, da Rin E, Davini D, Bonioli E, Boccardo F.

Department of Surgery, Lymphatic Surgery and Microsurgery Unit, S. Martino Hospital, University of Genoa, Genoa, Italy.

BACKGROUND:

Chylous ascites is the accumulation of triglyceride-rich, free, milk-like peritoneal fluid caused by the presence of intestinal lymph in the abdominal cavity. Primary chylous ascites is uncommon. We present our experience in the diagnosis and treatment of this condition.

METHODS:

Twelve patients (7 adults, 5 children) affected by primary chylous ascites were studied. Diagnostic investigations included abdominal sonography scans, lymphoscintigraphy, and lymphography combined with computed tomography (CT) with intravenous and intralymphatic lipid-soluble contrast, and laparoscopy. Magnetic resonance imaging was used when lymphography and lymphatic CT were not able to define the dysplasia well, or in the presence of lymphatic dilatation. Surgical treatment included laparoscopy (12/12), drainage of ascites (12/12), the search for and treatment of abdominal and retroperitoneal chylous leaks (12/12), exeresis of lymphodysplastic tissues (12/12), ligation of incompetent lymph vessels (9/12), carbon dioxide laser treatment (cut and welding effects) of the dilated lymph vessels using an operating microscope for magnification (9/12), and chylovenous and lymphovenous microsurgical shunts (7/12).

RESULTS:

Eight patients did not have a relapse of the ascites, and three patients had a persistence of a small quantity of ascites with no protein imbalance. Postoperative lymphoscintigraphy in seven patients confirmed better lymph flow and less lymph reflux. Median follow-up was 5 years (range, 3 to 7 years). We observed early relapse of chylous ascites in only one case that required a peritoneal-jugular shunt and led to good outcome.

CONCLUSION:

Primary chylous ascites is closely correlated to lymphatic-lymphonodal dysplasia that does not involve a single visceral district alone. Medical preoperative treatment played an essential role in the global management of this complex pathology. We demonstrated that the use of laparoscopy is remarkably advantageous for confirming diagnosis, for draining the ascites, and for evaluating the extension of the dysplasia. Our diagnostic work-up provided us with an exact diagnostic assessment and allowed us to plan a precise surgical approach.

PMID: 16765248 [PubMed - in process]

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Congenital Chylous Ascites: Report of Four Cases
and Review Of the Literature


Mahmoud Machmouchi, DESC, AESCP; Adnan Amin, MD; Issam Lanjaoui, MD;
Arnold Jacobs, MD; Chimène Hatoum, MD; Daifullah Al Zahrani, MBBS


From the Department of Pediatrics, Al Hada Armed Forces Hospital, Taif, Saudi Arabia.

This is a report of four neonates with chylous ascites, three of whom were recognized antenatally. The neonates were born at 34, 35 and 37 weeks’ gestation, respectively. Their birth weights ranged from 1270 g to 3500 g, and all had abdominal distention at birth. Analyses of the ascites fluid revealed raised levels of triglycerides, cholesterol and protein. Three of the cases responded to low-fat diet and medium-chain triglycerides with multiple paracentesis drainage. In the fourth case, the chylous ascites was associated with a macrodigit involving the right index and medius. The condition persisted despite 10 weeks of parenteral alimentation, and only resolved after an exploratory laparotomy done at the age of two months.


Case Reports

Case 1

The patient was a 1390 g male born after 34 weeks’ gestation to a 25-year-old gravida 3 para 3. The ascites was detected by ultrasonography at 31 weeks of gestation (Figure 1). At birth, the abdomen was very distended. paracentesis was performed and 200 ml of ascitic fluid was collected, showing a yellowish fluid rich in lymphocytes, with triglycerides of 1.4 mmol/l, cholesterol of 1.6 mmol/l, protein of 2.4 g/l and a specific gravity of 1.015. Because of the severe abdominal distention, a second paracentesis was done after three days, and enteral feeding was started at the age of six days by a formula rich in medium-chain triglycerides. The chylous ascites resolved completely within two weeks, and after 10 years of follow-up, no complications have been noticed.

Case 2

This patient was a 1270 g male born after 34 weeks’ gestation to a 32-year-old unbooked gravida 7 para 7. All his siblings had died in the neonatal period in another hospital. At birth, the patient presented with hypotonia, bilateral cataract and facial dysmorphy. Cytogenetic study of peripheral blood lymphocytes cultured by G-binding technique showed a mosaic (47xy+ marker chromosomes at 80%, and 46xy at 20%) chromosomal constitution in the analyzed cells. The abdomen was distended, and paracentesis showed a 150 ml milky fluid rich in lymphocytes, with triglycerides of 3 mmol/l, cholesterol of 2.2 mmol/l, and protein of 3.6 g/l. Ultrasound and CT scan confirmed the presence of hamartoma of the liver (Figure 2). The chilous ascites resolved completely after 10 days of parenteral alimentation, but the patient remained ventilator-dependent and died of respiratory problems at four months of age.


Case 3

This patient was a 3500 g female born after 37 weeks’ gestation to a 32-year-old diabetic gravida 6 para 5.

The ascites was detected by ultrasound at 35 weeks, with polyhydramnios. At birth, the patient presented with a small interventricular septal defect and a huge abdominal distention and respiratory distress. An urgent intra-peritoneal drain was inserted and a yellowish fluid was extruded which was rich in lymphocytes, with triglycerides of 3.3 mmol/l, cholesterol of 2.3 mmol/l, protein of 2.7 g/l, and a specific gravity 1.061.
In spite of complete and strict parenteral alimentation, the peritoneal drainage produced more than one liter of fluid in the first two weeks. The drainage was removed at the end of the third week, and multiple needle aspirations were done until the age of two months, when an exploratory laparotomy was performed. No macroscopic anomalies were found, but the origin of the superior mesenteric vessels was explored as recommended in the literature. At the age of two months, a macrodigit was also evident involving the index and medius. the index was amputated at two years of age. Following surgery, the patient completely recovered and continued to grow and develop normally at five years’ follow-up.


Case 4

This patient was a 2600 g male born after 35 weeks’ gestation to a gravida 1 para 1. the ascites was detected at 32 weeks with polyhydramnios. At birth, the abdomen was very distended, and the patient also had mild respiratory distress. A peritoneal drain was inserted which collected about 700 ml of yellowish fluid rich in lymphocytes,

Figure 1. Prenatal ultrasound showing evidence of ascites.
Figure 2. CT scan showing hamartoma of the liver after complete resolving of the chylous ascites.
cholesterol of 2 mmol/l, triglyceride of 2.1 mmol/l and protein of 3.2 g/l during the first week. The patient was put under complete parenteral alimentation for two weeks, and the chylous ascites completely resolved during the third week, with no recurrence over a one-year period of follow-up.


Common features of all the cases of chylous ascites mentioned above include the following:

Uneventful pregnancy
Spontaneous normal vaginal delivery
Polyhydramnios found during delivery


Ultrasound which revealed the presence of ascites before initial paracentesis, and was confirmed by laboratory results


A yellowish color of ascitic fluid initially, becoming milky after paracentesis was done five to six days later, mainly when the patient had been fed orally.


Discussion

Morton first described chylous ascites in an infant in 1691 after paracentesis on an 18-month-old male.1-2 The incidence of the condition has always been underestimated, and is thought to be between 1 in 50,000 and 1 in 100,000 hospital admissions.3 Congenital chylous ascites is even rarer, but is the most frequent cause of nonimmunologic peritoneal effusion. More than 10 studies have been reported in the last few years.
Congenital chylous ascites can be identified by antenatal ultrasonography (Figure 2), thereby eliminating an eventual traumatic result.4 the presence of hydramnios is the major associated anomaly.5-6 Other associations include chylothorax,7-9 lymphedema,8,9 pulmonary lymphangiectasis,10.11 intestinal lymphangiectasis,12-14 generalized lymphatic dysplasia,14 omental cyst,15 malrotation,5,16 meconium peritonitis,18 down’s syndrome, and other anomalies of genetic origin.16-20


Congenital chylous ascites is due to an inadequate lymphatic drainage from the intestine, resulting from maldevelopment of the intra-abdominal lymphatic system.3,12,21 The pathogenesis is poorly understood and genetic factors are discriminated. Consanguinity is a common feature,22,23 and the male is more liable to the condition.24 Cases of chylous ascites involving twins have also been reported.24,25 Fetal tachycardia accompanying a huge ascites has been reported,26 and cesarean may be prompted by fetal distress during labor.27 Prematurity is frequent,5-8 and neonatal respiratory distress and abdominal distention are also common, with ultrasound confirming the presence of fluid and abdominal x-ray showing a coloparietal undermining.


Paracentesis is the most useful diagnostic step. The chyle is usually color free, however, its appearance and composition are not constant, and depend on multiple factors such as the size of fat particles, cellular content and diet. Microscopic examination of the fluid demonstrates fat globules, and Wright’s stain shows a predominance of lymphocytes and concentration of triglycerides ranged from 1.4 to 3.8 mmol/l, cholesterol from 1.6 to 2.8 mmol/l, and protein level from 2.5 to 4.1 g/l. chylomicron can be found at a high concentration if the patient has been fed normally, and the specific gravity usually ranges from 1.010 to 1.021.5,6,18,28 After confirmation of the diagnosis, patients should be treated conservatively by dietary correction of any fluid, electrolytes and vitamin D deficiencies, and provided with a fat-free diet, with the fat being replaced by medium-chain triglycerides.5,28-31


In severe or complicated chyloascites or chyloascites that persists after a maximum of 10 weeks of diet, a maximum of 6-10 weeks’ of complete bowel rest and total parenteral nutrition should be initiated. Parenteral nutritional support appears to decrease the hazard of medical therapy by maintaining an adequate nutritional intake while eliminating obligate losses consequent to repeated paracentesis.31-33


Caty et al. have reported a successful treatment of congenital chyloascites by a somatostatin analog.34 This first line of therapy, in conjunction with multiple needle aspiration or drainage, depending on fetal tolerance, has been successful in more than 65%-70%.21,35,36 Prolonged use of low-fat infant formula has been associated with poor neurologic development, possibly from fatty acid deficiency, therefore, it should be limited to three to four months.5,20,30


In utero, evacuation of peritoneal fluid can be indicated in fetal distress.3,5 After a 10-week trial of bowel rest, most authors agree on abdominal exploration.37 Further imaging studies should also be considered—Tc 99m dextran lymphoscintigraphy,38,39 lymphangiogram or preoperative ingestion of the lipophylic dye40 can direct the surgical procedure.


Successful surgical treatment of congenital chylous ascites can be achieved in 80% of patients35 by resection of the macroscopic localized anomaly, or by ligation of an identifiable lymphatic leak.41-43

The most prominent location of the lymphatic leak is at the base of the superior mesenteric

vessel.15,35,36,42 If no leak can be identified, the area around the root of the mesenteric vessels should be closely inspected after mobilization of the colon, duodenum and the head of the pancreas,35,36,44,45 and hemostasis should be performed by multiple ligation.

A peritoneovenous shunt, either the Leveen or Denver type, has been reported to be successful at least temporarily, in children in whom repeated attempts of medical or surgical approach have failed.44,46 Rector and Whittlesey reported a complete control of chylous ascites by creating a circuit of extracorporeal recirculation.47


In a large collecting series, the recurrence of chylous ascites is not unusual and can occur even after three years. the death rate from chylous ascites is estimated to be between 24% and 30%,42,45 however, no recent report exists.


Congenital chylous ascites is an unusual and etiologically poorly understood entity. Prenatal paracentesis should be reserved for an unstable fetus. The surgical approach is indicated after failure of adequate medical treatment.

Article with Reference:


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Related Articles:

Successful surgical treatment of two cases of congenital chylous ascites.

Chylous ascites caused by Kaposi's sarcoma

Chylous ascites

Saturday, June 17, 2006

Hydrops Fetalis

Background:

Hydrops fetalis is Latin for edema of the fetus. Ballantyne first described hydrops fetalis in 1892, although it had been recognized for almost 200 years.

The hallmark of the disease is the abnormal accumulation of fluid in body cavities (pleural, pericardial, peritoneal) and soft tissues with a wall thickness of greater than 5 mm. In addition, hydrops fetalis is associated with polyhydramnios and a thickened placenta (>6 cm) in as many as 30-75% of patients. Many affected fetuses also have hepatosplenomegaly.

Pathophysiology:

The basic problem is an imbalance in fluid homoeostasis, with more fluid accumulating than can be resorbed. This imbalance can result from 2 broad categories of pathologies, namely, those of an immune origin and those of a nonimmune origin.

Immune-related hydrops fetalis (IHF) results from alloimmune hemolytic disease or Rh isoimmunization.

The mother is sensitized and has antibodies against fetal blood cells, causing hemolysis in the fetus when circulated maternal antibodies (immunoglobulin G [IgG]) cross the placenta to reach fetal circulation. Most cases occur because of antibodies to D-positive Rh antigen, although some cases can occur because of antibodies to C-positive and E-positive Rh antigens. Rare blood group antibodies, such as the Kell (K) system and the Duffy (Fy) system, also can cause hydrops.

Nonimmune-related hydrops fetalis (NIHF) can result from primary myocardial failure, high-output cardiac failure, decreased colloid oncotic plasma pressure, increased capillary permeability, and obstruction of venous or lymphatic flow. Fetal cardiac anomalies are the most common cause of nonimmune-related hydrops fetalis. Chromosomal anomalies are the second most common cause.

In addition to the causes of IHF, several conditions can cause NIHF. The most common cause of NIHF is cardiovascular abnormality, followed by chromosomal abnormalities; however, the number of nonimmune-related causes that can and have resulted in hydrops fetalis is extensive and includes the following partial list:
Fetal structural abnormalities


Cranial - Cerebral tumor, intracranial hemorrhage, and vein of Galen aneurysm

o Cardiovascular - Arrhythmias (tachyarrhythmias, bradyarrhythmias), cardiac tumors (rhabdomyoma, hemangioma, hamartoma), cardiomyopathy, Ebstein anomaly, endocardial fibroelastosis, high-output failure (fetal angiomas, sacrococcygeal teratomas, vein of Galen aneurysm, twin-twin transfusion syndrome, twin-reversed arterial perfusion [TRAP] syndrome), myocardial infarction, myocarditis, premature closure of the foramen ovale, right or left heart hypoplasia, and single ventricle

o Neck or thoracic masses - Congenital cystic adenomatoid malformation, cystic hygromas, diaphragmatic hernia, hydrothorax/chylothorax, mediastinal teratoma, pulmonary sequestration, and thoracic tumors

o Gastrointestinal-tract abnormalities - Bowel atresias and volvulus, cirrhosis, hemochromatosis, hepatic tumors (hemangioendotheliomas), hepatitis, hepatoblastoma, lymphangiomas, and meconium peritonitis

o Urinary-tract abnormalities - Congenital nephritic syndrome, polycystic kidneys, prune belly syndrome, renal vein thrombosis, and urinary tract obstructions (lower or upper)

o Chromosomal anomalies - Trisomy 21, trisomy 18, trisomy 13 triploidy, and XO syndrome (Turner syndrome)

· Anemias -
Thalassemia, congenital leukemia, fetomaternal hemorrhage, glucose-6-phosphate dehydrogenase (G-6-PD) deficiency, human parvovirus B19 (B19V) infection, twin-twin transfusion syndrome (donor), and fetal closed-space hemorrhage


· Infection - Coxsackie virus, cytomegalovirus (CMV), hepatitis A virus, leptospirosis, listerosis, B19V, rubella virus, syphilis, toxoplasmosis, and varicella virus

· Genetic disorders

Metabolic disorders - Gaucher disease, Hurler disease, hypothyroidism, hyperthyroidism, mucolipidosis, and mucopolysaccharidosis

o Skeletal dysplasias - Achondrogenesis, achondroplasia, asphyxiating thoracic dystrophy, lethal osteoporosis, Noonan syndrome, short rib–polydactyly syndrome, and thanatophoric dysplasia
o Fetal hypokinesis - Arthrogryposis, congenital myotonic dystrophy, Neu-Laxova syndrome, and Pena Shokeir syndrome


· Idiopathic disorders - Recurrent isolated hydrops

· Maternal disorders - Graves disease, severe anemia, severe diabetes mellitus, and severe hypoproteinemia

· Placental disorders - Chorioangioma, chorionic vein thrombosis, cord torsion (knot or tumor), umbilical artery aneurysm, and venous thrombosis

Frequency:

Hydrops fetalis is more common in undeveloped countries than in developed countries. Figures from Thailand suggest an estimated incidence of 1 case per 500-1500 pregnancies because of an association with homozygous athalassemia. The incidence of IHF has decreased with the development of better prophylaxis, and it is not considered a major problem in developed countries. However, in undeveloped countries, IHF still occurs in a small and declining number of cases.

Mortality/Morbidity:

Mortality and mortality figures vary, but in general, the mortality rate is high.

Treatment is reported to be successful in 10-40% of patients, depending on the cause of the disease and the sophistication of available diagnostic and therapeutic options.

Many cases of NIHF occur as a result of complex chromosomal or anatomic anomalies that worsen the prognosis.

Other causes of poor prognosis include pulmonary hypoplasia caused by pleural and peritoneal fluid accumulation and an early onset of labor because of distention of the uterus caused by polyhydramnios and/or fetal body enlargement secondary to edema.

Race: Certain racial predilections exist for pathologic conditions that can lead to hydrops fetalis.
Predisposing factors include the severity of hemolysis in African populations and the variations in the a-chain structure in Asian and Mediterranean populations.


In the Far East, a thalassemia is a major cause of nonimmune-related hydrops fetalis. The condition is uniformly fatal and associated with a significant risk of maternal morbidity. The a thalassemia gene is found in 20-30% of the population in Southeast Asia.

Sex:

X-linked chromosomal abnormalities are found in many fetuses with hydrops fetalis.

Anatomy:

Hydrops fetalis is often diagnosed by using routine sonograms when the typical features are depicted. In other fetuses, a clinical suspicion of hydrops fetalis may exist because of a previous family history of a similarly affected baby or because ultrasonography is performed to evaluate polyhydramnios.

Clinical Details:

The conditions causing hydrops fetalis are diverse; however, common mechanisms that cause the fluid imbalance can be identified. These causes include the following:

(1) cardiac failure resulting from myocardial disease, arrhythmia, complex anatomic cardiac defects, or abnormal intracardiac or extracardiac shunts (high-output failure);
(2) abnormal blood composition with severe anemia or abnormal red cell physiology or counts;
(3) aberrations of lymphatic drainage; and
(4) masses in the abdomen or chest that hamper venous return.


Sonograms depict anasarca (edema) and fluid collection in serous cavities, such as the pleural, pericardial, and peritoneal spaces. Polyhydramnios and an edematous thick placenta are often present.

Ascites may be small and be just enough to form a film over the abdominal contents, or ascites may be extensive with the contents of the abdomen, liver, and gut floating in the fluid. The ascites may extend into the scrotum to form a hydrocele.

Pleural effusions can be unilateral or bilateral. Unilateral effusions indicate the presence of a process such as chylothorax. Large effusions can compress the mediastinal vessels, cause upper body edema, and interfere with esophageal functioning to cause secondary polyhydramnios.

Edema may be localized to one part of the body, or it may be generalized. Edema is seen most easily over the skull, over which a halo is formed. Edema may be seen in other parts of the body as well.

Placental thickening is a late occurrence, and when affected, the placenta is thicker than 4-5 cm over its entire extent.

The distribution and size of fluid accumulations may indicate the pathology. In IHF, ascites appears first, with edema and pleural collections appearing late.

The findings of specific organ pathology, for example, skeletal abnormalities or cardiac tumors, may indicate a specific cause in hydrops fetalis.

Preferred Examination:

Immune-related hydrops fetalis

A history of a previously affected fetus in the family is of critical importance. Once IHF is suspected, maternal blood typing and antibody screening against Rh and a determination of minor blood types (eg, Kell, Duffy, MNSs) should be performed. In mothers in whom immunoglobulin M (IgM) is detected, no further workup is needed, but if IgG is detected, titers of Rh-positive antibodies in the maternal blood need to be determined. A titer of greater than 1:16 is significant. If titer results are significant, amniocentesis should be performed to assess the severity of fetal hemolysis and anemia.

Fetal anemia can be monitored either by direct sampling of fetal blood by means of cordocentesis or by determining the delta optical density (OD) by using a wavelength of 450 mm in the amniotic fluid. This measurement gives an estimate of bilirubin levels during the third trimester. Delta OD results are plotted on the Liley 3-zone chart. The closer the results are to the third zone, the greater is the risk of IHF. A fetal hematocrit determination is the final test to be performed, and fetal transfusion should be considered in fetuses with a hematocrit level of less than 40%.

Nonimmune-related hydrops fetalis

NIHF can result from a large number of causes, including chromosomal abnormalities, cardiac failure, tumors, and twin-twin transfusion syndrome. Extensive clinical workup is required to attempt to identify the specific etiology. In patients in whom NIHF is suspected, the search for a cause starts with a maternal evaluation. Initial clinical history taking should be directed toward the presence of hereditary or metabolic diseases, diabetes, infections, anemias, and use of all medications. Initial investigations include an indirect Coombs test to exclude immune causes, followed by the determination of routine blood counts and indices to exclude thalassemias; maternal blood chemistry testing for G-6-PD deficiency; Betke-Kleihauer testing for fetal-maternal transfusion; and screening for toxoplasmosis, other infections, rubella, CMV, and herpes simplex (TORCH) infection during intrauterine pregnancy.

Amniocentesis is needed to perform fetal karyotyping, amniotic fluid culturing, testing for CMV infections, assessment of a-fetoprotein (AFP) levels, testing for thalassemia, and determination of the lecithin-sphingomyelin (L/S) ratio. Karyotyping can also be performed with tissue obtained by chorionic villous sampling (CVS) or with fluid obtained from one of the fetal cavities. A chromosome count and karyotype can be obtained rapidly by using fluorescent in situ hybridization (FISH) technique. The FISH technique can also help in the detection of specific deletions and chromosomal rearrangements, and the results are often available within 24-48 hours.

Fetal blood tests should include hemoglobin chain analysis for thalassemia and fetal serum albumin levels.
Initially, sonographic findings suggest hydrops fetalis in most cases, and ultrasonography can also be used for follow-up imaging to observe the progress of the condition if the pregnancy is continued.
Limitations of Techniques: Ultrasonographic findings are often reliably helpful in the diagnosis of the disease causing fetal hydrops, especially in fetuses in whom a chest mass or cardiac disease is present. However, in many fetuses, an exact etiology is not forthcoming after an ultrasonographic examination.


Blood tests performed in the mother can provide information regarding Rh and other immune causes of hydrops fetalis and evidence of infection and metabolic diseases. However, invasive fetal testing must eventually be performed by means of amniocentesis or cordocentesis. Both methods pose a risk of fetal death.

Differential Diagnosis

Cystic Hygroma Encephalocele Polyhydramnios

Other Problems to be Considered:

Macrosomia
Urinary ascites
Meconium ascites
Isolated pericardial effusionIsolated ascites
Idiopathic polyhydramnios
Fetal cystic hygromas
Caput succedaneum
Crocodile skin

X-Ray

Findings:

Antenatal radiography has no place in the diagnosis of fetal hydrops because it is essentially a disease of soft tissue and because of the reservations of using radiographs in pregnant women.

CAT Scan

Findings:

CT scans may offer better anatomic resolution, but CT scans are difficult to obtain in the presence of an active fetus, and radiation exposure in pregnant women is a concern.

MRI

Findings:

Exquisite anatomic detail can be depicted on MRIs, especially on those obtained with newer algorithms that allow fast acquisitions and that minimize the effect of fetal movement. However, MRI has not become a standard modality because of the limited availability of state-of-the-art equipment for fast imaging and because of the expense involved. In addition, ultrasonography is widely available and can adequately provide most of the required information. These factors have hindered a wider use of MRI in fetal imaging.

Ultrasound

Findings:

Ultrasonography remains the cornerstone of fetal imaging in fetuses in whom hydrops fetalis is suspected. Sonograms demonstrate the cardinal signs of the disease, namely, fetal skin edema (>5 mm), fluid in a serous cavity, polyhydramnios, and a thickened placenta. These signs can be seen in different combinations and to differing extents in various diseases. Additional findings, depending on the specific etiology causing the hydrops, are occasionally seen as well.

The minimum diagnostic criteria include the following: fluid accumulation in at least 2 serous cavities (ascites, pleural effusion or pericardial effusion) or 1 serous effusion and generalized anasarca. A single site of fluid accumulation is generally not enough to diagnose hydrops unless a preexisting pathology that is strongly associated with hydrops (eg, chest mass) is also present.

False Positives/Negatives:

A few conditions mimic full-blown hydrops fetalis, but individual components of hydrops fetalis can be seen in other conditions, even as normal variants.

Normal fetal hair and a thick scalp can occasionally be seen, and this finding must be differentiated from skin edema. Similarly, cystic hygromas and loops of cord near the body wall can suggest skin thickening.

Occasionally, a thick layer of subcutaneous fat may cause confusion.

The thick, folded skin, occasionally termed crocodile skin, is a normal variant that can cause confusion with skin edema.

A congenital cystic adenomatoid malformation of the lung, a diaphragmatic hernia, and a bronchogenic cyst can suggest pleural effusions.

Pseudoascites, obstructed or mature bowel, fetal abdominal cysts, and an obstructed urinary system can mimic ascites. Pseudoascites refers to an artifactual hypoechoic rim that is sometimes seen in the fetal abdomen; this is due to hypoechoic deep abdominal wall muscles or the diaphragm. Pseudoascites usually disappears when scanning is performed from another direction. Other features that differentiate pseudoascites from ascites are as follows: (1) Pseudoascites is not seen past the anterior edge of the ribs. (2) Pseudoascites is confined to the upper abdomen, unlike ascites, which is diffuse. (3) With ascites, the hyperechoic outer margin of the umbilical vein can be seen, as can the falciform ligament.

Intervention

Intervention:

The mainstay of treatment is interventional fetal therapy. In a few patients, drugs administered to the mother elicit a response and reach the fetus transplacentally. In fetuses with IHF, treatment essentially involves correcting fetal anemia. In all patients, fetal anemia associated with hydrops fetalis is an absolute indication for fetal blood sampling followed by in utero transfusion. Ultrasonographic guidance is essential for fetal blood transfusion. For this, intravascular transfusion (IVT) is preferred over the intraperitoneal route. Of the many methods available, the prognosis is better in fetuses receiving intravascular transfusions than in those receiving intraperitoneal transfusions because peritoneal absorption is often impaired in affected fetuses. With IVT, 70-85% of fetuses with hydrops and 85-95% of fetuses without hydrops can survive. The therapy associated with the highest incidence of consistent benefit to the fetus is correction of fetal anemia via fetal blood transfusions.

Treatment in patients with NIHF is more complex and must be directed at the cause. One way to classify treatments is to separate them into noninvasive and invasive categories.

Noninvasive treatment may include the following:

Antiarrhythmic drugs

o Antibiotics
o Correction of maternal diabetes and hyperthyroidism


· Invasive treatment: The aggressiveness with which the following treatments are performed depends on the resources, sophistication, and experience of the treating unit.

Some attempted procedures include the following:

Correction of fetal anemia in fetal hemorrhages, parvovirus infections, and, possibly, thalassemia

o Amnioreduction by means of serial amniocentesis
o Fetoscopic laser ablation of communicating vessels in twin-twin transfusion syndrome
o Cord occlusion in cardiac twins
o Thoracocentesis in chylothorax and large pleural collections
o Vesicoamniotic drainage in urinary tract obstructions
o Fetal surgery to correct diaphragmatic hernias and sacrococcygeal teratomas


Remember that the appearance of the features of hydrops fetalis usually signals an advanced stage in the progression of the disease, and the prognosis is poor in most fetuses. However, specialists in fetal medicine and intervention should be consulted in all cases to decide if therapy is appropriate and, if it is, to determine which therapy to use.

Indian Doctors

Sunday, June 11, 2006

NEW LYMPHEDEMA PEOPLE FORUMS

Remember, this was the week with the date 06/06/06??With only an hours notice GoDaddy, our fee-paid host of LymphedemaPeople abruptly decided our forums were gobbling up too much space,so they shut them down.

As a result, we had to put in completely new ones.

But, it takes more then lymphedema, lymphoma or GoDaddy to slow us down and...

THE NEW FORUMS ARE UP AND RUNNING!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!

Our new forums represent a significant upgrade with many new features, upgraded security and abilities. There are a number ofnew forums that we have added (including one for cancer) and many familiar ones like our children's forum, advocacy and more.

If you were a member of our old forums, we would love to have youcontinue with our family.

Please go ahead and reregister. We were hoping to automaticallytransfer membership, but that may be more problematic then we realized.


If you have never joined us there, come, share the excitement as wemove forward with the most comprehensive website on the internet forlymphedema and lymphatic conditions.

I will be working feverishly this weekend to see that all thearticles of the old forums are in place again.

In the meantime look forward to seeing everyone there!!!

Lymphedema People

My Best to All!!!!

Pat

Saturday, June 03, 2006

Early Lymph Vessel Development From Embryonic Stem Cells

(Arteriosclerosis, Thrombosis, and Vascular Biology. 2006;26:1073.)Published online before print March 16, 2006

© 2006 American Heart Association, Inc.

Johan Kreuger; Ingrid Nilsson; Dontscho Kerjaschki; Tatiana Petrova; Kari Alitalo; Lena Claesson-Welsh

From the Department of Genetics and Pathology (J.K., I.N., L.C.-W.) Uppsala University, Sweden; the Department of Pathology (D.K.), University of Vienna Medical School, Austria; Molecular/Cancer Biology Laboratory and Ludwig Institute for Cancer Research (T.P., K.A.), Helsinki University Central Hospital, Finland.

Correspondence to Johan Kreuger, The Rudbeck Laboratory, Department of Genetics and Pathology, Uppsala University, Dag Hammarskjöldsv. 20, SE-75185 Uppsala, Sweden. E-mail johan.kreuger@genpat.uu.se

Objective—

The purpose of this study was to establish a model system for lymph vessel development based on directed differentiation of murine embryonic stem cells.

Methods and Results—

Stem cells were aggregated to form embryoid bodies, and subsequently cultured in 3-dimensional collagen matrix for up to 18 days. Treatment with vascular endothelial growth factor (VEGF)-C and VEGF-A individually enhanced formation of lymphatic vessel structures, although combined treatment with VEGF-C and VEGF-A was most potent and gave rise to a network of LYVE-1, podoplanin, Prox1, and VEGF receptor-3 positive lymphatic vessel structures running parallel to and apparently emanating from, capillaries. In contrast, fibroblast growth factor-2, hepatocyte growth factor, or hypoxia had little or no effect on the development of the early lymphatics.

Further, cells of hematopoietic origin were shown to express lymphatic markers. In summary, different subpopulations of lymphatic endothelial cells were identified on the basis of differential expression of several lymphatic and blood vessel markers, indicating vascular heterogeneity.

Conclusions—

We conclude that the present model closely mimics the early steps of lymph vessel development in mouse embryos.

We have established a model system for lymph vessel development based on directed differentiation of murine embryonic stem cells. Vascular endothelial growth factors, but not other growth factors tested, or hypoxia, induced lymph vessel formation, indicating different mechanisms of lymph vessel formation during embryonic development and in the adult.

Key Words: embryoid body • lymphangiogenesis • LYVE-1 • Prox1 • VEGF-C • VEGF receptor-3

American Heart Association