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Biomedical subjects

P W Callen

Publications and source records attributed to P W Callen.

At least 37 records · Page 2Linked to original sources
PubMed1993

Frequency of fetal anomalies in sonographically detected polyhydramnios.

One hundred and five patients who met the criterion of having an amniotic fluid pocket depth greater than 8.0 cm were categorized as polyhydramniotic. Of these cases, 82% were singleton pregnancies and 18% were twin pregnancies. The degree of polyhydramnios correlated directly with the probability that an anomaly would be detected. For the lowest rank group (pocket depth of 8 to 9.5 cm), 50% of fetuses manifested an anomaly, whereas the highest rank (16.0 cm or greater pocket depth) carried an 88% risk for an anomaly. Overall, 63% of pregnancies with polyhydramnios revealed anomalies. Sonography found all to be anomalous. There were three false diagnoses of potential anomalies. Monochorionic anomalies of twinning (twin transfusion syndrome and acardiac twin) and gastrointestinal anomalies among singletons were the most commonly seen abnormalities. However, a broad spectrum of anomalies was represented in the study group. Only five diabetic mothers were seen in our study cohort, and in each of them the pregnancy was further complicated by an associated fetal anomaly.

Brain↗
PubMed1993

Growth retardation in prenatally diagnosed cases of gastroschisis.

Gastroschisis is a rare congenital anomaly characterized by the herniation of fetal intestines directly through an abdominal wall defect. It is associated infrequently with chromosomal or other nonbowel defects and can be treated surgically after delivery, with survival rates reported to be between 87 and 100%. We reviewed 21 cases of prenatally diagnosed gastroschisis to ascertain the effect of fetal growth retardation on perinatal outcome. Ten of the 21 fetuses (48%) were identified prenatally as growth retarded, although only seven of these ten truly had birth weights less than the 10th percentile. Three additional fetuses that had not been identified prenatally as growth retarded did, in fact, have birth weights less than the 10th percentile, for a total frequency of growth retardation at birth of 48% (10/21 fetuses). When compared to non-growth-retarded fetuses with gastroschisis, fetuses who were growth retarded, although more likely to have been delivered by emergency cesarean section, had shorter hospitalization times, were more likely to have undergone primary closure on the first day of life, and had fewer major complications. We conclude that growth retardation is common in fetuses with gastroschisis and the postnatal outcome in gastroschisis is not poorer for fetuses who are growth retarded.

Abdominal Muscles↗
PubMed1993

The lemon sign: not a specific indicator of meningomyelocele.

The association of the "lemon sign" with myelomeningocele has been well documented. This study was performed to determine if this sign is exclusive to myelomeningocele. The study population included all abnormal fetuses in our data base with this sonographically observed finding, from 1988 to 1991 (total of 23 cases). Twelve fetuses were found to have a myelomeningocele and six an encephalocele. Five fetuses with the lemon sign demonstrated a variety of structural anomalies not involving the neural tube. This sonographic finding appears not to be limited to cases of myelomeningocele.

Female↗
PubMed1993

The AIUM/ACR antepartum obstetrical sonographic guidelines: expectations for detection of anomalies.

A survey was sent to 52 physicians considered experts in obstetrical sonography asking them to comment on the probability of observing various fetal abnormalities when the AIUM/ACR guidelines for a level one obstetrical sonogram were followed. Although definite trends were noted in several areas, there was much diversity in opinion concerning what should or should not be seen when the guidelines were followed. Given the fairly specific nature of the AIUM/ACR guidelines, we were uncertain why the responses were not in more uniform agreement.

Congenital Abnormalities↗
PubMed1993

The role of velamentous cord insertion in the etiology of twin-twin transfusion syndrome.

OBJECTIVE: To evaluate the prevalence of velamentous cord insertion in twin-twin transfusion using the hypothesis that such insertions may contribute to the etiology of the condition. METHODS: All cases of placentas referred for pathologic evaluation at the University of California at San Francisco from 1984-1992 were reviewed for the citation of diamniotic-monochorionic placentation, including the presence of velamentous cord insertions. Maternal and infant records were studied for findings consistent with twin-twin transfusion syndrome. RESULTS: Thirty-eight cases of monochorionic-diamniotic twins were identified, 11 of which showed twin-twin transfusion syndrome. The prevalence of velamentous cord insertion in the transfusion syndrome subset was 63.6%, compared with 18.5% in those without (significant difference at P < .01). Twin-twin transfusion syndrome pregnancies with velamentous insertions were delivered at a significantly earlier gestational age; they also had fewer surviving infants and were more likely to have been treated prenatally than transfusion syndrome pregnancies without velamentous insertion, although these latter two findings were not significantly different. CONCLUSIONS: Velamentous cord insertions are more common in twin-twin transfusion syndrome pregnancies and may contribute to the development of profound disparity in fluid volume because the membranously inserted cord can be easily compressed, reducing blood flow to one twin. Large-volume amniocentesis may reduce this compressive force on the cord insertion, thus explaining the success of this mode of intervention.

Female↗
PubMed1992

Outcome of antenatally diagnosed cystic adenomatoid malformations.

OBJECTIVE: Twenty-two cases of antenatally diagnosed congenital cystic adenomatoid malformations are reported. STUDY DESIGN: Case management is reviewed. RESULTS: Eighteen women continued pregnancy after diagnosis. In nine cases nonimmune hydrops fetalis did not develop and all infants survived. Nonimmune hydrops fetalis developed in the other nine; fetal intervention was performed in eight cases. In the single case of nonimmune hydrops fetalis without intervention, the neonate died. In four cases aspiration of macrocystic lesions was performed. In two cases cystoamniotic shunts were placed. Neither aspiration or shunting provided long-term benefit. In six cases fetal lobectomy was ultimately performed and four survived. Two fetuses did not undergo in utero surgery; one was delivered prematurely after cyst aspiration and lived, and the other previable fetus was delivered soon after shunting. CONCLUSIONS: Fetal survival is best related to development of nonimmune hydrops fetalis. Aspiration of cystic lesions and cystoamniotic shunts generally provide short-term benefit. Early experience with fetal surgery for congenital cystic adenomatoid malformations has been encouraging.

Cystic Adenomatoid Malformation of Lung, Congenita↗
PubMed1992

The "lying down" adrenal sign: a sonographic indicator of renal agenesis or ectopia in fetuses and neonates.

An inability to image the kidneys, severe oligohydramnios, and an empty (nonvisualized) urinary bladder are the most common sonographic findings in fetuses with renal agenesis. The same features, except for the oligohydramnios, are seen in neonates with renal agenesis. Failure to visualize a kidney in the usual flank location with or without demonstration of the kidney in an ectopic location may also be a feature in fetuses or neonates with renal ectopia. The adrenal gland has an unusual but distinctive appearance on longitudinal sonograms in these patients. Sonograms of 23 fetuses and six neonates referred for presumed bilateral or unilateral renal agenesis or ectopia were reviewed retrospectively for the presence of a flattened ("lying down") adrenal gland. At the time of the examination, the adrenal gland was not actively sought as a part of the fetal survey or postnatal examination but was found retrospectively in 48% of these subjects. Although this finding has been described previously, the emphasis was on this observation as a potentially confusing sonographic feature. This manuscript emphasizes the characteristic appearance of the adrenal gland which instead serves as a simple means of confirming that the kidney did not develop in the flank. Detection of a flattened ("lying down") adrenal gland is an observation that should be actively sought in all fetuses and neonates with a presumed diagnosis of renal agenesis or ectopia.

Adrenal Glands↗
PubMed1992

The choroid plexus pseudocyst: sonographic identification and characterization.

Amniocentesis has been advocated by some authors when fetal choroid plexus cysts are discovered, because of their reported association with karyotype abnormalities. We have noted an oval hypoechoic structure projecting into the adjacent choroid plexus, which simulates a cyst when imaged across its short axis, in 39 of 50 consecutive fetuses. This presumably normal structure or pseudocyst may represent the corpus striatum. Knowledge of its existence and benign nature will help avoid diagnostic errors and unnecessary amniocenteses.

Amniocentesis↗
PubMed1991

Ultrasound-guided aspiration of a neonatal brain abscess.

The authors successfully treated a Serratia marcescens brain abscess in the right parieto-occipital region of a newborn infant born at 27 weeks' gestation and weighing 800 g. Bedside ultrasound-guided aspiration techniques and local anesthesia were used to treat the abscess.

Brain Abscess↗
PubMed1990

Central nervous system damage and other anomalies in surviving fetus following second trimester antenatal death of co-twin. Report of four cases and literature review.

Four cases of multiple gestation with second trimester death of one fetus and subsequent damage to a survivor are reported. Monochorionic placentation was documented in three of the cases. Central nervous system lesions occurred in all cases, and bowel injury was noted in two of the damaged fetuses. Although rare maternal clotting problems have been reported in similar situations, none was noted in any of these four cases. Prior reports have indicated that losses in the first half of gestation were of no consequence to the surviving fetuses. These four cases contradict this suggestion, and indicate that close sonographic observation of the survivors is important in any multiple gestation where on fetus has died.

Abnormalities, Multiple↗
PubMed1990

Fetal intervention in obstructive uropathy: prognostic indicators and efficacy of intervention.

Management of the fetus with bilateral hydronephrosis is controversial; ability to predict outcome and efficacy of prenatal intervention are unknown. We studied 40 fetuses referred for ultrasonography, examination of fetal urine, and possible therapy. We retrospectively assigned fetuses to a good prognosis group if fetal urine was hypotonic (sodium less than 100 mEq/L, chloride less than 90 mEq/L, osmolarity less than 210 mOsm/L) and there was no ultrasonographic evidence of dysplasia; we assigned fetuses to a poor prognosis group if even one criterion was abnormal. Survival was greater in the good prognosis group than in the poor prognosis group (81% vs 12.5%; 87% vs 30%, excluding abortions) (p less than 0.005). We then attempted to assess the efficacy of prenatal urinary decompression by comparing outcome within the good and poor prognosis groups. Survival with intervention was greater in both the good prognosis group and the poor prognosis group (89% vs 70% and 30% vs 0%). In 6 of the 8 survivors in the good prognosis group, severe oligohydramnios was reversed by decompression. We conclude the fetal urine electrolyte levels and ultrasonographic appear helpful in predicting residual fetal renal function and neonatal outcome and that prenatal decompression may prevent the development of fatal pulmonary hypoplasia.

Amniotic Fluid↗
PubMed1990

Correction of congenital diaphragmatic hernia in utero, V. Initial clinical experience.

Review of our experience with 45 cases of prenatally diagnosed congenital diaphragmatic hernia (CDH) confirms that most fetuses (77%) will not survive despite optimal pre- and postnatal care. Polyhydramnios, associated anomalies, early diagnosis, and a large volume of herniated viscera (including liver) are associated with a particularly dismal prognosis. After extensive experimental work demonstrated the efficacy, feasibility, and safety of repair in utero, we attempted to salvage six highly selected fetuses with severe CDH by open fetal surgery. Five had liver incarcerated in the chest: three died at operation because attempts to reduce the liver compromised umbilical venous return. In one, a Goretex diaphragm was constructed around the liver, but the baby died after birth. The last two fetuses, one with incarcerated liver, were successfully repaired. Both demonstrated rapid growth of the lung in utero, had surprisingly good lung function after birth despite prematurity, had the abdominal patch removed at 2 weeks, and subsequently died of nonpulmonary problems (an unrelated nursery accident in one and intestinal complications in the other). The only maternal complication was amniotic fluid leak and preterm labor. All six women are well and four have had subsequent normal children. From this phase I experience, we conclude that fetal surgery appears safe for the mother and her reproductive potential, that fetal CDH repair is feasible in selected cases, and that the fetal lung responds quickly after decompression. However, fetal repair remains a formidable technical challenge.

Adolescent↗
PubMed1989

Primary fetal hydrothorax: natural history and management.

Primary fetal hydrothorax presents a wide spectrum of severity ranging from small, harmless effusions, to life-threatening thoracic compression. To define natural history and management, we reviewed 32 cases seen at two large perinatal centers from 1980 to 1987. Spontaneous resolution of the effusions was seen in three fetuses, all of whom survived. Three fetuses were electively terminated. The overall mortality was 53%. In the 24 untreated fetuses, sex and the presence of polyhydramnios did not influence mortality, but hydrops, gestational age less than 35 weeks at delivery, and bilateral effusions were associated with a poor prognosis. Five fetuses underwent in utero decompression. In four, thoracentesis was performed, with rapid reaccumulation of the effusion. All four died from pulmonary insufficiency. In the fifth fetus, a thoracoamniotic shunt permanently decompressed the effusion, with resolution of the hydrops, and delivery of a normal viable infant. We conclude that (1) primary fetal hydrothorax may resolve or progress to hydrops, necessitating close follow-up with ultrasound; (2) pulmonary hypoplasia as a result of undrained large pleural effusions may result in neonatal mortality; (3) the gestational age at both diagnosis and delivery, the development of hydrops, and bilaterality of effusions are important prognostic predictors; and (4) the fetus with large effusions and hydrops has a poor prognosis, and thoracic decompression with a thoracoamniotic shunt may prove life saving.

Female↗
PubMed1989

High-output cardiac failure in fetuses with large sacrococcygeal teratoma: diagnosis by echocardiography and Doppler ultrasound.

With two-dimensional echocardiography and Doppler ultrasound, we demonstrated high-output cardiac failure in three fetuses with large sacrococcygeal teratomas. All fetuses had normal cardiac structure, dilated ventricles maintaining a normal fractional shortening index, a dilated inferior vena cava reflecting the increased venous return from the lower body, pericardial and pleural effusions as a manifestation of fetal hydrops, and a markedly thickened placenta. When fetal hydrops was present, the combined ventricular output was very high (mean 1280 ml/min/kg; normal 553 +/- 153 (SD)). Descending aortic flow was also sharply increased (mean 930 ml/min/kg; normal 184 +/- 20), as was placental flow (mean 480 ml/min/kg, normal 110 +/- 26). High-velocity arterial flow signals were also found within the tumor. In one fetus studied serially, placental thickness and tumor diameter increased rapidly; placental flow as a percentage of descending aortic flow decreased, indicating a further increase of flow to the tumor. These abnormal hemodynamic changes were reversed after the fetus's teratoma was surgically removed. We conclude that the sacrococcygeal teratoma acts as a large arteriovenous fistula, which causes high-output cardiac failure. Surgical removal of the teratoma in a previable fetus with such hemodynamic findings may prove to be the most effective treatment.

Echocardiography↗
PubMed1989

Effacement of the fetal cisterna magna in association with myelomeningocele.

The cisterna magna is effaced in association with myelomeningocele. The authors retrospectively investigated the size of the fetal cisterna magna as a predictor of fetal myelomeningocele in 67 pregnant women (17-38 menstrual weeks) referred for prenatal sonography because of an elevated serum alpha-fetoprotein level (n = 61) or a suspicion of fetal ventriculomegaly on previously obtained sonograms (n = 6). Twenty fetuses had myelomeningocele, 14 had isolated ventriculomegaly, and 33 were normal. A normal-sized cisterna magna (range, 4-9 mm in depth) was present in all normal fetuses. In 19 of 20 fetuses with myelomeningocele, the views of the posterior fossa were adequate, and in each of these the cisterna magna was effaced (n = 18) or very small (n = 1). The cisterna magna was effaced in five of 13 (38%) fetuses with isolated ventriculomegaly in whom the posterior fossa was adequately imaged. Although effacement of the cisterna magna is a nonspecific finding, the high negative predictive value of this sign is useful during routine screening of the fetal neural axis.

Cisterna Magna↗
PubMed1989

Fetal tissue sampling. The San Francisco experience with 190 pregnancies.

Prenatal diagnosis of genetic defects was done using fetal blood sampling in 167 at-risk pregnancies, by fetal skin biopsy in 15 pregnancies, and by fetal liver biopsy in 8 pregnancies. Fetal blood sampling was done by fetoscopy through January 1985 and by sonographically directed percutaneous umbilical blood sampling since then. In our series, cytogenetics has become the major indication for fetal blood sampling, increasing from 6% of the cases with fetoscopy to 48% with umbilical blood sampling. Fetoscopy provided pure fetal blood in 61% of cases while umbilical blood sampling provided pure fetal blood 97% of the time. The corrected risk of fetal demise after percutaneous umbilical fetal blood sampling was 2% and after fetoscopy was 4%.

Biopsy↗