Biomedical subjects

A Grignon

Publications and source records attributed to A Grignon.

At least 37 records · Page 2Linked to original sources

PubMed1997

Liver transplantation: review of the literature. Part 2: Vascular and biliary complications.

The first attempted human orthotopic liver transplantation, in 1963, involved a child with biliary atresia, who died on the operating table as a result of uncontrollable coagulopathy. Improvements in immunosuppression, surgical technique, medical imaging and postoperative care, as well as more stringent patient selection, have allowed the development of liver transplantation and its universal acceptance as the treatment for a variety of liver diseases. The radiologist plays a major role in the multidisciplinary transplantation team and must be familiar with each stage of orthotopic liver transplantation and its associated complications. In the first article of this series (Can Assoc Radiol J 1997;48[3]:171-178), the authors reviewed the anatomic features and current concepts relevant to orthotopic topic liver transplantation. In this, the second article, they discuss the vascular and biliary complications of the operation, and the third article will cover the medical complications.

Biliary Tract Diseases↗

PubMed1997

Liver transplantation: review of the literature. Part 3: Medical complications.

The first attempted human orthotopic liver transplantation, in 1963, involved a child with biliary atresia, who died on the operating table as a result of uncontrollable coagulopathy. Improvements in immunosuppression, surgical technique, medical imaging and postoperative care, as well as more stringent patient selection, have allowed the development of liver transplantation and its universal acceptance as the treatment for a variety of liver diseases. The radiologist plays a major role in the multidisciplinary transplantation team and must be familiar with each stage of orthotopic liver transplantation and its associated complications. In the first article of this series (Can Assoc Radiol J 1997;48[3]: 171-178), the authors reviewed the anatomic features and current concepts relevant to orthotopic liver transplantation. In the second article (Can Assoc Radiol J 1997;48[4]: 231-242), they discussed the vascular and biliary complications of the operation. This, the third and final article in the series, covers the medical complications.

Communicable Diseases↗

PubMed1996

Gastroschisis: are prenatal ultrasonographic findings useful for assessing the prognosis?

OBJECTIVE: The objective of this study was to assess various prenatal patterns in correlation with survival and the occurrence of complications of antenatally recognized gastroschisis (G). MATERIALS AND METHODS: We retrospectively studied 34 cases of G. Mortality and morbidity in the postnatal period were assessed and correlated with the prenatal presence or absence of: (1) bowel and/or stomach dilatation, (2) thickening and/or hyperechogenicity of the intestinal wall, (3) meconium peritonitis (in the abdomen) before 20 weeks of gestation, (4) asymmetrical bowel dilatation, and (5) associated malformations. Morbidity took into account the length of hospitalization and the number of surgical procedures. RESULTS: The overall survival rate was 94%. Neither bowel nor stomach dilatation was significantly correlated with mortality. However, evidence of intestinal dilatation greater than 17 mm had a positive predictive value of 67% for atresia, with a negative predictive value of 86%. Thickening and/or hyperechogenicity of the bowel wall were not significantly associated with mortality. Meconium peritonitis before 20 weeks and asymmetrical bowel dilatation were not statistically significant because of the small sample size. Twelve patients (35.3%) had postnatal complications, with a mean hospital stay of 127 days. Outcome was not modified by the mode of delivery. Associated extradigestive anomalies were present in 20.6% of cases. Chromosomal anomalies were not seen. CONCLUSION: The prognosis of prenatally detected G is excellent despite the frequency of small bowel atresia (67%) in the group with postnatal complications. Meconium peritonitis before 20 weeks of gestation and/ or asymmetrical bowel dilatation also appear to be indicators of atresia (2/4, 50%) or high morbidity (3/4, 75%).

Abdominal Muscles↗

PubMed1996

Imaging features of type 1 hereditary tyrosinemia: a review of 30 patients.

Hereditary tyrosinemia type 1, a common genetic disorder in the province of Quebec, is characterized by a deficiency of fumarylacetoacetate hydrolase. In this autosomal recessive disorder of tyrosine metabolism, the accumulation of succinylacetone leads to neurologic crises, acute and chronic liver failure, complex renal tubulopathy, rickets and a hemorrhagic syndrome. Liver trans- plantation has dramatically modified the spontaneous course of this lethal disease. The present paper describes the imaging features of tyrosinemia in 30 patients followed from 1980 to 1995 at Hôpital Sainte-Justine, Montreal, Canada.

Adolescent↗

PubMed1996

Chromosomal anomalies in newborns with omphalocele.

Omphalocele is the most common congenital abdominal wall defect; its reported incidence is 1 in 4,000 to 5,000 live births. With large defects, the liver is a median organ and lies within the sac (extracorporeal liver [ECL]). With small defects, only bowel or stomach is found outside the abdominal cavity (intracorporeal liver [ICL]). The goal of this study was to determine whether a relationship exists between the sac contents or the timing of diagnosis and the incidence of chromosomal abnormalities or survival among fetuses and newborns with omphalocele. From 1985 to 1995, 83 cases of omphalocele were managed at the authors' institution. In 50 cases the diagnosis was made using prenatal ultrasonography. All patients underwent fetal cardiac echography and amniocentesis. Twenty-four pregnancies were terminated electively because of severe associated anomalies. Of the 59 live births, 41 patients (69%) survived. The incidences of cardiac, chromosomal, and other anomalies were 24% (14), 10% (6), and 21% (16), respectively. Omphalocele with ICL is associated with a better survival rate than omphalocele with ECL (82% v 48%; P < .01) despite the significantly higher rate of karyotype abnormalities (16% v 0%; P < .05). The prognosis was poorer for patients with prenatally diagnosed omphalocele than for those with a postnatal diagnosis (mortality rate, 42% v 21%) because the former group had a higher percentage (70% v 9%) of ECL. Although the incidence of cardiac anomalies was similar for the ECL and ICL groups (33% v 18%), the former had more complex malformations. Death usually occurred in newborns who had neonatal respiratory distress owing to prematurity, or in those with chromosomal or cardiac anomalies. Chromosomal anomalies occurred mainly in cases of small omphaloceles that contained gut only, and it was the major cause of death among this group. In ECL cases, survival was primarily affected by the associated complex cardiac anomalies.

Chromosome Aberrations↗

PubMed1996

Fetal congenital diaphragmatic hernia: accuracy of sonography in the diagnosis and prediction of the outcome after birth.

OBJECTIVE: This study evaluated the diagnostic accuracy of prenatal sonography in congenital diaphragmatic hernia (CDH) and assessed sonographic predictors of postnatal outcome. MATERIALS AND METHODS: Sonograms and medical records of 43 fetuses with CDH were retrospectively reviewed. Sonographic features were correlated to clinical evolution and surgical and pathologic findings. RESULTS: CDH was diagnosed prenatally with sonography in 40 cases. Intrathoracic stomach and liver were routinely identified. Ipsilateral lung tissue could not be differentiated from herniated content. Contralateral lung was identified in all cases except two. The overall survival rate was 43% after excluding terminated pregnancies. Besides associated malformations and chromosomal anomalies, the only statistically significant predictor of survival was the quantification of the contralateral lung area at the level of an axial four-chamber view: The survival rate was 86% when the contralateral lung area was equal to or greater than one half the area of the hemithorax. CONCLUSION: Sonography is highly accurate for prenatal diagnosis od CDH. Sonography also assists the prognostication of postnatal outcome in isolated CDH by allowing quantification of the contralateral lung area on a four-chamber view.

Female↗

PubMed1995

Renovascular hypertension in children: curability predicted with negative intrarenal Doppler US results.

PURPOSE: To assess whether intrarenal Doppler ultrasound (US) enables prediction of the outcome of renovascular hypertension in a pediatric population. MATERIALS AND METHODS: A prospective study of 29 children with renin-mediated hypertension was performed. In these patients, intrarenal Doppler US was performed before angiography. Doppler US and angiographic findings were compared with patient outcome with respect to treatment required and blood pressure (BP) status after therapy. Cure was defined as a normal BP without medication. RESULTS: Intrarenal Doppler US was positive in 15 patients (52%), group 1, and negative in 14 patients (48%), group 2. In 10 patients (67%) in group 1, the severity of the vascular lesion precluded permanent cure. Cure was achieved in all patients in group 2, except for patients with neurofibromatosis. Thus, there was a statistically significant association (P < .05) between cure and a negative Doppler US result. CONCLUSION: In children with renovascular hypertension, a negative Doppler US result enables the prediction that a cure is more likely to be achieved with endovascular therapy or surgery.

Angioplasty, Balloon↗

PubMed1994

Autosomal dominant polycystic kidney disease in the fetus.

We report on 3 cases with a fetal presentation of autosomal dominant polycystic kidney disease (ADPKD), which illustrate the variable expression of ADPKD during fetal life. Fetus 1 was diagnosed at 20 weeks of gestation by ultrasonography; a molecular prenatal diagnosis was performed at 10 weeks on fetus 2, a sib of fetus 1; and ADPKD was an incidental finding in fetus 3 who was aborted at 16 weeks for anencephaly. All pregnancies were terminated and pathologic studies of the fetal kidneys were performed. From these cases and a review of the literature, we draw the following conclusions: (1) so far, all fetal ADPKD kidneys that have been histologically studied have shown cystic dilatations; 28/32 of these fetuses had ultrasonographic manifestations of the disease and/or had sibs with an early-onset form of it; (2) these cysts can be found in newly formed nephrons (fetus 2), predominantly in the more mature nephrons of the deep cortex (fetus 1) or more sparsely distributed in the cortex (fetus 3); these different patterns may reflect different rates of progression of the disease; (3) in contrast to the histologic findings in adult kidneys, glomeruli seem to be predominantly affected in fetal ADPKD; (4) severe fetal expression of ADPKD seems to cluster in some families; and (5) so far, all DNA analyses performed in families with subjects presenting during the fetal or neonatal period have been consistent with linkage to the PKD1 locus.

Adult↗

PubMed1993

Testicular torsion in infants and children: diagnosis with Doppler sonography.

The accuracy of Doppler sonography in the evaluation of testicular torsion was tested in 65 boys (aged 0-18 years) with acute scrotal pain or swelling. All patients underwent pulsed Doppler sonography of both testes, followed by scintigraphy (n = 16) and/or surgery (n = 34) and a close clinical follow-up for 4-8 months (n = 31). Color Doppler sonography was performed in 29 patients. The testicular artery was deemed patent if Doppler shifts from branches within the parenchyma could be found. Surgery revealed 19 cases of testicular torsion, 17 of which were diagnosed with Doppler sonography. There were six technical failures, in which no signals could be found on either side. In four boys, no color signals were obtained in either testis but subsequent examination with a mechanical sector scanner and pulsed Doppler sonography yielded arterial signals. Doppler sonography was successful in 59 of 65 boys (91%) and yielded a sensitivity of 89% and specificity of 100%. Pulsed Doppler sonography with mechanical sector scanners was more sensitive than color Doppler sonography. Intermittent torsion was missed both with Doppler sonography and scintigraphy.

Adolescent↗

PubMed1993

Renal vein thrombosis in children: evidence of early flow recovery with Doppler US.

PURPOSE: To characterize renal arterial and venous Doppler signals in pediatric renal vein thrombosis (RVT) and to study changes in the circulation in the months following the acute event. MATERIALS AND METHODS: Ten patients with proved acute RVT (eight infants and two boys with renal allografts) were studied with serial Doppler ultrasonography (US) of the inferior vena cava and the main renal and intrarenal veins and arteries. RESULTS: The resistance index in the affected vessel was increased by 10% compared with that of the normal side in patients with unilateral RVT. Only the allografts had reversed diastolic flow. Venous flow, which was detected around the thrombus and in intrarenal veins in all native kidneys, was absent during the 1st week in the transplanted kidneys but reappeared thereafter in one. Perirenal collateral vessels were demonstrated with color Doppler US in one baby. Seven of eight native kidneys atrophied, and the allografts failed. CONCLUSION: Classic Doppler signs of RVT--absent venous flow and reversed diastolic arterial flow within the kidney--were present in only the acute phase in transplanted kidneys. These signs are unreliable in RVT of native kidneys.

Child↗

PubMed1993

Duplex Doppler sonographic examinations of the testis in prepubertal boys.

This retrospective study of 143 pediatric patients with unilateral acute scrotal disease was done to assess the value of duplex Doppler sonographic examination prior to puberty (110 patients) in comparison to a pubertal group (33 patients) in a pediatric hospital, where the examinations are done by staff radiologists and radiology residents of varying degrees of expertise and experience with Doppler technique. All patients seen during an 18 month period were included. The unaffected side was examined in most patients and served as control. The normal Doppler shift in the center of the prepubertal testis was found to be 0.2 to 0.5 kHz, when using a 5 MHz duplex Doppler probe. With puberty, the Doppler shift increased to 0.5 to 1 kHz. Of 18 patients (10 prepubertal) with testicular torsion, five (three prepubertal) had false-positive Doppler shift. In four of these five cases, faulty placement of the Doppler sample volume cursor was probably the cause. Using a multi-way frequency analysis, puberty was found to have no significant influence on results of Doppler signal (chi square = 0.1346; P = 0.7137). Duplex Doppler sonographic examination is as useful to rule out testicular torsion in prepubertal boys as it is after puberty. Meticulous technique is essential. The opposite side should be examined first and serves as control for the affected one. Results showing no flow in the center of the diseased testis with positive flow in the unaffected one should lead to further clinical action (scintigraphy or surgery).

Adolescent↗

PubMed1992

Benefits of combined balloon pumping and percutaneous cardiopulmonary bypass.

Sixteen patients (2 women, 14 men) aged 29 to 72 years with continued cardiogenic shock during intraaortic balloon pumping (IABP) had additional treatment with percutaneous cardiopulmonary bypass (PBY). Cause of cardiogenic shock was myocardial infarction in 7 (3 survived), failed percutaneous transluminal coronary angioplasty requiring emergency coronary artery bypass grafting in 5, postoperative aortic valve replacement in 1, postoperative emergency coronary artery bypass grafting in 1, after cardiac transplantation in 1, and bridging to transplantation in 1. Mean blood pressure with PBY and IABP combined was 75 mm Hg versus 60 mm Hg with IABP off. Percutaneous cardiopulmonary bypass flows ranged from 0.8 to 2.1 L/min with a mean flow of 1.3 L/min. Time on IABP ranged from 24 hours to 1 week. Time on IABP to PBY ranged from 1 to 20 hours, and time on PBY ranged from 65 minutes to 20 hours. Ten of 16 (63%) were successfully weaned, and 3 died after weaning. Seven of 16 (44%) survive. Combined IABP with PBY appears to be a better therapy than either one individually. Staging the therapy as the balloon first in and last out appears to be a good methodology.

Adult↗

PubMed1992

Intussusception in children: reliability of US in diagnosis--a prospective study.

To assess the diagnostic value of ultrasound (US) in clinically suspected acute intestinal intussusception in children, the authors prospectively compared US and enema studies in 83 episodes. None of the cases negative at US proved to be intussusception at enema study (negative predictive value = 100%). The sensitivity of US was 100%, and the specificity was 88%. Most of the sonograms were initially obtained and examined by residents. Several unsuspected abnormalities were also found with US. The authors conclude that a few months of training in US appears to be sufficient for high-accuracy investigation of clinically suspected intussusception, enabling selection of those patients in need of an enema.

Barium Sulfate↗

PubMed1991

In utero sonographic diagnosis of diaphragmatic hernia with hepatic protrusion into the pericardium mimicking an intrapericardial tumour.

A case of right-sided congenital diaphragmatic hernia was detected at 33 weeks of gestation. Fetal echocardiography revealed the presence of an intrapericardial mass (3.5 x 3 cm) localized at the right of the heart and surrounded by a massive pericardial effusion. This mass had the same echogenicity as the liver, with which it shared vascular channels. The diagnosis of right diaphragmatic hernia with protrusion of hepatic tissue into the pericardial sac and secondary pericardial effusion was made and confirmed after birth. In utero diagnosis of this anomaly enabled correct assessment of perinatal risk, and optimal fetal and infant management.

Adult↗

PubMed1991

Antenatal diagnosis of ovarian cysts: natural history and therapeutic implications.

A retrospective study from 1980 to 1990 shows 29 ovarian cysts in 27 patients diagnosed by prenatal ultrasound performed between 28 and 38 weeks of gestation. Ten patients underwent surgery, 17 patients were observed with serial ultrasound. Delayed good quality sonograms after spontaneous resolution of the cyst in a selected group of 7 patients showed restoration of a normal ovarian anatomy. The size of the cyst and/or its sonographic characteristics are the 2 main factors for deciding a conservative or a surgical management.

Female↗

PubMed1990

Testicular infarction in the newborn: ultrasound findings.

Three patients with neonatal testicular torsion and infarction (two bilateral, one unilateral) are presented with a distinctive sonographic appearance. All five testes appeared inhomogeneously hypoechoic and each was surrounded by a brightly echogenic rim. Whereas surgical exploration was required in the past to establish the diagnosis of testicular infarction in the neonate, sonographic demonstration of the abnormality in the appearance of the testicular parenchyma permits nonoperative diagnosis. Because surgical salvage of the testis in the setting of neonatal extravaginal torsion is thought to be quite rare, the necessity of removing the testis is less clear when the diagnosis is established preoperatively.

Humans↗

PubMed1990

Normal portal venous diameter in children.

A study was conducted on 156 children, in whom the portal veins were measured using standard real time ultrasonography. Knowledge of the normal dimension may be important in patients with liver disease.

Adolescent↗

PubMed1990

Acute appendicitis in children: evaluation with US.

During a 4-month period, high-resolution ultrasonography (US) was used to prospectively evaluate 70 children with clinically suspected acute appendicitis. Thirty-five US scans showed a noncompressible appendix with maximal outer diameters greater than 6 mm. This finding was considered positive for the diagnosis of acute appendicitis. Thirty-one of these 35 patients had acute appendicitis documented by surgical and pathologic findings. The remaining four patients were observed, and their symptoms resolved. Thirty-five patients had US scans considered negative for appendicitis. Seventeen of these patients had US findings positive for other conditions including mesenteric adenitis, ileitis, intussusception, Crohn disease, and Burkitt lymphoma. In this series US enabled diagnosis of acute appendicitis with a sensitivity of 94%, a specificity of 89%, and a predictive accuracy of 91%. Diagnosis of acute appendicitis can be made with US with the same accuracy in children as has been previously reported in series of adult patients. The use of US in clinically ambiguous cases may allow earlier diagnosis, prevention of perforation, and decreased complications in the pediatric patient with acute appendicitis.

Acute Disease↗