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Biomedical subjects

F Rypens

Publications and source records attributed to F Rypens.

At least 37 records · Page 2Linked to original sources

[Abdominal complications of ventriculoperitoneal shunts].

Three cases of abdominal complications of ventriculo-peritoneal shunts are reported. Abdominal pseudocysts were identified in 2 patients (surinfection was proven in one of them). Malposition of the shunt was demonstrated for the third patient. Ultrasound was the most helpful imaging technique for the detection of these abdominal complications. Abdominal computed tomography confirmed the sonographic findings before the patients were reoperated.

Abdomen↗

Twin-twin transfusion syndrome--possible roles for Doppler ultrasound and amniocentesis.

A 29-year-old woman was referred for suspicion of twin-twin transfusion syndrome (TTTS). Several ultrasonographic and neonatal criteria of TTTS were encountered in this twin pregnancy. The peculiar observations in this case were, firstly, the demonstration of superficial anastomosis by Doppler ultrasound and, secondly, that one single therapeutic amniocentesis could have been sufficient to partially correct the progression of the syndrome, as after amniocentesis it was no longer possible to demonstrate the vascular communication. This observation suggests that superficial anastomoses could also have a role in the genesis of TTTS. Their effect could be monitored by Doppler ultrasound and could be more easily corrected by therapeutic amniocentesis.

Adult↗

Atypical and equivocal sonographic features of the spinal cord in neonates.

Thanks to the wider use of sonography to examine the spinal content in the neonate, normal anatomy and anomalies may be detected easily. Yet, unusual sonographic patterns are also observed. These must be differentiated from true pathologies. During a prospective study of 103 neurologically asymptomatic neonates, atypical sonographic patterns were found in 16 patients, corresponding to normal variants in 13. Nine of these 13 patients presented with a widening of the distal part of the central echo complex (one had a dilated ventriculus terminalis). Nerve roots of the cauda equina were disposed asymmetrically in three patients; the spinal cord movements were still present. In two of these babies, this distribution was associated with thin arachnoid pseudocysts. One patient presented with transitorily hyperechoic and narrow subdural spaces, probably related to neonatal dehydration. None of the 13 patients showing normal variants required any treatment. The other 3 patients (of 16) presented with equivocal entities of unknown evolution: sonographic tethered cord, fibrolipoma of the filum terminale and epidural varices. Sonography is highly accurate in evaluating the spinal cord content and aids differentiation of normal and normal variants from equivocal or pathological entities.

Diagnosis, Differential↗

[Spiral tomodensitometry of pancreatic calcifications].

Chronic pancreatitis is characterized by the formation of intraductal precipitates that may later grow and calcify, forming large stones. These calcified stones, representing almost all the calcifications visible in chronic pancreatitis, are located in the major pancreatic duct or in the secondary branches. During the past 10 years, new sophisticated endoscopic techniques have been developed to remove obstructing calculi from the main pancreatic duct. These techniques require an accurate evaluation of the location of the calculi, since calculi cannot be removed from secondary branches. Therefore, a new radiological approach has been developed, based on helicoidal scanning and multiplanar and tridimensional reconstructions of the calculi layout.

Calculi↗

Hepatic cysts and hyperechogenicities: perinatal assessment and unifying theory on their origin.

The authors report their experience with the perinatal diagnosis of six cases of hepatic cyst and six of liver hyperchogenicities. The in utero diagnosis of hepatic cysts was difficult when the cysts were large or subhepatic. A precise diagnosis was sometimes achieved only after surgery. Small intraparenchymal cysts tended to regress spontaneously. Liver hyperechogenicities were diffuse or localized. They were unrelated to liver infection, tumors, meconium peritonitis or biliary tract anomaly. Both entities could be related to vascular disruption phenomenon (VDP) in which structural anomalies result from damage to normal development of embryonic or fetal vessels with anomalies of perfusion to the developing organs. The consequences of VDP to the liver are variable depending on the time and duration of the phenomenon. Localized infarct or ischemia can fibrose or calcify leading to segmental hyperechogenicities. Necrosis with tissue reabsorption can be the origin of some (sub)hepatic cysts. When such anomalies are detected there should be a careful study of the placentation, and a search for potential associated anomalies should be undertaken.

Cysts↗

Transjugular intrahepatic portosystemic stent shunt as a rescue treatment after sclerotherapy failure in variceal bleeding.

BACKGROUND: Variceal bleeding carries high early mortality, especially after failure of conventional treatments such as endoscopic injection therapy. The present study analyses the efficacy of transjugular intrahepatic portosystemic stent shunt (TIPS) in cirrhotic patients after failure of sclerotherapy for variceal bleeding. METHODS: Twenty-four consecutive patients underwent TIPS in this indication. RESULTS: The procedure was successful in all patients, with reduction of size or disappearance of varices in 96% of them. Four patients (17%) developed encephalopathy and six (25%) rebled during the follow-up period (median 5 months; range 1-19). Thirty-day mortality was only 17% and 29% during the follow-up period. Deaths were mainly due to liver failure, especially after procedures performed in emergency. Significant decrease in liver function was observed in the days following the procedure. To maintain long-term patency of the shunt, revision was required in nine patients (38%). CONCLUSIONS: TIPS seems to be a promising salvage therapeutic procedure after failed sclerotherapy, but this needs to be addressed in controlled trials.

Esophageal and Gastric Varices↗

Fetal esophagus: normal sonographic appearance.

Our objective was to describe the sonographic appearance of the normal fetal esophagus and to determine the rate of its visualization. The fetal esophagus has a tubular echogenic appearance. Two patterns of the tubular structure were observed: two parallel echogenic lines or several parallel echogenic lines (the so-called "multilayered pattern"). A cannula was placed in the stomach of three stillborns and removed under ultrasonographic monitoring, confirming its location. In 155 consecutive pregnancies examined, the thoracic part of the fetal esophagus was easy to visualize (about 90% of cases); the cervical and abdominal segments were more difficult to visualize (19 and 30%, respectively). The multilayered pattern was observed in 49% of cases before and in 87% of cases after 26 weeks' gestation. A direct sonographic demonstration of the fetal esophagus is possible and could help to exclude esophageal malformations.

Embryonic and Fetal Development↗

Sonographic demonstration of congenital adrenal hyperplasia in the neonate: the cerebriform pattern.

Sonographic examination of the adrenal glands of three newborns with congenital adrenal hyperplasia demonstrated a cerebriform pattern. This is introduced as a sonographic feature specific to the disease. This finding in patients with ambiguous genitalia should suggest the diagnosis even if the adrenals are not significantly enlarged, and should prompt appropriate biochemical analysis and treatment.

Adrenal Glands↗

Large solitary non-parasitic cyst of the liver.

Non-parasitic solitary liver cysts are rare in children. Yet they should be included in the differential diagnosis of superior abdominal masses. We report one case in a 7-year-old boy that illustrates the difficulties of the diagnosis.

Carcinoma, Hepatocellular↗

A hypothesis for the higher incidence of vesico-ureteral reflux and primary megaureters in male babies.

The authors propose a new explanation for the male preponderance in cases with prenatally diagnosed vesico-ureteral reflux and primary megaureters. The theory is based on conclusions drawn from the characteristics of 4 patients (3 perinatal cases and 1 occurring in a 14-year-old boy) presenting with unusual anomalies of the lower urinary tract. In this hypothesis, the male preponderance could be related to an abnormal dilatation of the posterior urethra occurring during the embryological development of the male urethra. The dilatation leads to a flap valve mechanism and to a functional obstruction of the bladder outlet and finally to secondary dilatation of the upper urinary tract. This obstruction may be transitory; reflux and megaureters found in utero or after birth could be considered as sequellae of this phenomenon.

Adolescent↗

Unusual splenic complication of acute pancreatitis.

Splenic complications of acute pancreatitis are rare. We describe a spontaneous subcapsular splenic laceration during an episode of acute pancreatitis, without any evidence of one of the currently reported predisposing factors. Its spontaneous resolution suggests that conservative therapy can be proposed in such complications.

Acute Disease↗

Abdominal muscle use during breathing in patients with chronic airflow obstruction.

To assess the pattern of abdominal muscle contraction in stable patients with chronic obstructive pulmonary disease (COPD), we studied electromyograms of the rectus abdominis, external oblique, and transversus abdominis muscles in 40 patients with variable degrees of chronic airflow obstruction (FEV1 between 17 and 82% of predicted); 12 control subjects with normal pulmonary function tests were studied for comparison. The subjects were studied during resting breathing in the supine posture, and the electromyograms were recorded with concentric needle electrodes implanted with the aid of a high-resolution ultrasound. The rectus abdominis and external oblique were silent in virtually all patients. In contrast, 17 patients had invariable phasic expiratory activity in the transversus abdominis, and 11 additional patients had intermittent transversus expiratory activity. Expiratory contraction of the transversus was related to the degree of airflow obstruction (p less than 0.005), and when present, it persisted in the seated posture. We conclude that (1) when breathing at rest, many stable patients with severe chronic airflow obstruction contract the abdominal muscles during expiration, and (2) this expiratory contraction is usually confined to the transversus muscle. These observations also indicate that the physiology of dynamic hyperinflation and intrinsic positive end-expiratory pressure (PEEP) in such patients should be reevaluated.

Abdominal Muscles↗

The ureterovesical junction in children: sonographic findings after surgical or endoscopic treatment.

We retrospectively analyzed pre- and postoperative sonographic and medical records of 335 children who had surgical or endoscopic treatment at the ureterovesical junction, in order to determine normal and atypical sonographic appearances. Normal sonographic findings after ureteral reimplantation include thickening of the posterior bladder wall, pseudodiverticular sacculations, bladder asymmetry, and transitory hydroureteronephrosis. Short-term or persistent (lasting more than 1 month) hydroureteronephrosis, urinoma, hematoma, bladder lithiasis, and diverticula were abnormal findings, occurring in 17% of the patients. After partial ureteronephrectomies, visualization of the residual ureter on sonograms was not possible in cases without complications; in one patient, reflux of fluid dilated the residual ureter and made the ureter visible on sonograms. After endoscopic incisions, the masslike appearance of a collapsed ureterocele was observed. Submucosally injected Teflon always appeared as a curvilinear hyperechoic area with an acoustic shadow. Marked acute or persistent hydroureteronephrosis or ectopic intracavitary Teflon particles were observed in 2% of patients. Granuloma formation was considered likely in 5% of the patients when the area of injected Teflon material was longer than 12 mm on sonograms. Submucosally injected collagen appeared less echogenic than Teflon and showed no acoustic shadowing. The various normal sonographic appearances after treatment must be known in order to distinguish them from significant abnormalities. In patients with anatomic anomalies, such as short-term or persistent hydroureteronephrosis, urinoma, hematoma, and lithiasis, complementary uroradiologic examinations may be necessary to clarify the diagnosis.

Adolescent↗