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Biomedical subjects

L Bolondi

Publications and source records attributed to L Bolondi.

At least 127 records · Page 7Linked to original sources

The sonographic appearance of the normal gastric wall: an in vitro study.

In order to evaluate the real number and anatomical correspondence of the ultrasonographically recognizable layers within the gastric wall, we used a high frequency (7.5 MHz) rotating transducer to examine five surgical specimens of the stomach suspended in a water bath. Five layers were always clearly distinguishable within the gastric wall, whose thickness was 3-6 mm. Fine needles and lancets were localized at the level of the 3rd hyperechoic layer when inserted in the submucosa and in the 4th hypoechoic layer when inserted in the muscolaris propria. Thin echogenic bands were always displayed on both sides of other homogeneous tissues (spleen, myometrium) suspended in water. On the basis of these findings and also taking in account the physical laws of ultrasound interactions with tissues, we conclude that the 1st and the 5th hyperechoic layers are partially generated by ultrasound reflection at the interface liquid/wall. The 2nd hypoechoic layer corresponds to the deepest part of the mucosa; the 3rd hyperechoic to the submucosa and the submucosa/muscularis propria interface and the 4th hypoechoic layer to the muscularis propria.

Gastroscopy↗

Technique of endoscopic ultrasonography investigation: esophagus, stomach and duodenum.

Endoscopic ultrasonography (EUT) allows a better sonographic image of the internal organs. Moreover, it is possible for the first time to explore the upper GI tract wall. To achieve this, three methods are available: 1) direct apposition of the transducer on the mucosa; 2) contact of a small balloon filled with water over the tip of the ultrasonic probe; 3) direct instillation of water. The esophageal wall is explored with the first and second method; the gastric wall is best explored with the third method; the duodenal wall is explored with the second or the third method. Exploration of esophagus and stomach has been achieved in 100% of cases, duodenal exploration in 72% of cases. No complications occurred in this study.

Duodenoscopy↗

Problems and variations in the interpretation of the ultrasound feature of the normal upper and lower GI tract wall.

The aim of this study was to define the various ultrasound appearances of the normal upper and lower GI tract wall and to discuss current interpretations of the relationship between each echographic layer with the real anatomical structures. We studied a total of 70 patients by means of endoscopic ultrasonography and examined in vitro some surgical specimens of the normal stomach, colon and rectum. We found a 'five layer' structure at the level of the esophageal and gastric wall. This pattern was not recognized in the duodenum during the in vivo study. Our experimental results support the hypothesis that the first and fifth hyperechoic layers of the gastric wall are partially generated by ultrasound reflection at the interface liquid/wall and that the second hypoechoic layer corresponds to the deepest part of the mucosa. Important variations in the thickness of each layer were found in different conditions during in vivo studies. The fourth hypoechoic layer becomes very thin after water distension of the stomach. The in vitro investigation of the specimen of normal colon and rectum showed some different features. At this level it is sometimes possible to distinguish a separate very thin hypoechoic layer in the deepest part of the second layer, probably corresponding to the muscularis mucosae. The muscular layer is sharply divided into two distinct layers related to the circular and longitudinal muscular coats.

Digestive System↗

Detection of portal hypertension and esophageal varices by means of endoscopic ultrasonography.

Endoscopic ultrasonography (EUT) enables not only the visualization of the portal system and of the esophageal varices, as obtained by transabdominal ultrasonography and fiberoptic endoscopy, but also the visualization of intramural and periesophageal collateral veins. Fifteen cirrhotic patients were examined by EUT without complications. When present, esophageal or gastric varices were always detected. In all cases enlarged extrinsic periesophageal veins were visualized, and in 14 of 15 their caliber was correlated with the size of esophageal varices. In three patients examined after sclerotherapy the submucosal veins had disappeared, but extrinsic collateral vessels were patent. EUT will probably become a fundamental technique in the study of portal hypertension and esophageal varices, before and after therapy.

Adult↗

Intraoperative ultrasonography in surgery for liver tumors.

Intraoperative ultrasonography was used in 37 patients during surgery for suspected liver tumors. The size, number, and site of the lesions were determined together with the relationship of the tumor to the intrahepatic vessel, as well as possible small daughter lesions within the liver. Final diagnosis in these patients was hepatocellular carcinoma in 19 cases, metastases from colorectal cancers in 15 cases, and benign lesions in three cases. Previously undetected small tumors were revealed in one patient with sigmoid cancer and in five patients with liver cell carcinoma who had cirrhosis. Vascular tumoral infiltrations were easily displayed and the surgical approach modified accordingly: a more extended resection was performed in two cases of huge central hepatic metastases. Intraoperative ultrasonography revealed seven cases of small (2 to 3 cm) hepatocellular carcinomas in cirrhotic livers that were not visible or palpable, thus allowing a subsegmentary resection. Finally, in three cases of atypical tumors, an intraoperative echo-guided biopsy specimen was required to establish the benign nature of lesions and resection was avoided. Intraoperative ultrasonography facilitates the diagnosis of small liver tumors and can also aid the surgeon in his choice of technique, especially in cases of cirrhosis of the liver. A resection can be avoided altogether when multiple lesions are involved, or echo-guided subsegmentary resections can be performed in cirrhotic livers when a less extended resection is required. This technique makes it possible to establish the relationship between the tumor and intrahepatic vessels, thus preventing vascular injury and making radical hepatic resection safer.

Biopsy↗

Measurement of gastric emptying time by real-time ultrasonography.

This paper describes an ultrasound method of assessing gastric emptying time based on measurements of the gastric antrum, which is visible in almost all subjects before and after meals. A total of 54 subjects were examined including 18 normal subjects and 36 subjects with idiopathic functional dyspepsia. The emptying time was determined in all subjects by measuring the changes in the cross-sectional area of the gastric antrum. In a subgroup of 34 subjects the volume of the whole antropyloric region was also considered. Measurements were taken by the same observer after fasting and at regular 30-min intervals after a standard 800-cal meal. Final emptying time (calculated in relation to the start of the meal) was considered to be the time at which the antral area or volume returned to basal value. Final emptying time (mean +/- SD) was 248 +/- 39 min in normal subjects and 359 +/- 64 min in patients with functional dyspepsia (p less than 0.001). A significantly higher degree of dilatation of the gastric antrum was found in dyspeptic patients than in control subjects. Barium x-ray of the stomach in 19 subjects always confirmed the ultrasound finding on the presence or absence of contents within the stomach. We conclude that this kind of ultrasound study of the antropyloric region allows accurate determination of total gastric emptying time.

Adolescent↗

Gall bladder sludge formation during prolonged fasting after gastrointestinal tract surgery.

In this study we have ultrasonographically assessed the prevalence of sludge in a group of 48 fasting patients after gastrointestinal tract surgery. Ultrasound examinations were carried out daily in each patient, beginning on the day before surgery. The period of fasting lasted from seven to 10 days. The presence of sludge was demonstrated within the seventh day in seven out of the 48 patients. In 38 cases fast lasted for a further three days. The total number of sludge-positive patients after 10 days was 12 out of 38. Ultrasound controls were performed after six and 12-24 month interval and showed the presence of gall stones with different ultrasonographic patterns in three sludge positive patients. We conclude that in the early postoperative period there is a high risk for sludge development and that in some cases sludge may subsequently evolve into gall stones.

Adult↗

Ultrasound detection of unusual spontaneous portosystemic shunts associated with uncomplicated portal hypertension.

Seven cases of unusual spontaneous portosystemic shunts observed by ultrasonography in the last 8 months are reported, including cases of coronary vein varicocele and patent umbilical vein; two cases of spleno-retroperitoneal anastomosis; omphalo-ilio-caval anastomosis; superior mesenteric vein-inferior vena cava anastomosis; spleno-renal anastomosis; and spleno-portal anastomosis and anastomosis from the splenic vein to the abdominal wall. One of these collateral vessels was also analyzed by pulsed Doppler flowmetry. The patients were either cirrhotic or had pre-hepatic portal hypertension (resulting from chronic pancreatitis) and gave no history of gastrointestinal bleeding or ascites. Two of these patients had previously undergone surgery for problems associated with cholestasis. In both cases, presurgical sonographic studies were used to guide the surgical procedures in the hope of preserving the anomalous connections. Furthermore, ultrasound detection of spontaneous portosystemic shunts was an important factor in interpreting the clinical symptoms of these patients.

Adult↗

[Renal angiomyolipoma. Analysis of a clinical case in the light of current diagnostic possibilities].

A clinical case of renal angiomyolipoma is examined. Until a few years ago diagnosis of this condition was almost exclusively intraoperative or during autopsy. Today, the introduction of new diagnostic techniques like echotomography and CT permit the identification of the lesion and its differentiation from other spreading renal processes. This has obviously had a beneficial effect on the choice of therapeutic approach.

Angiography↗

Secretin administration induces a dilatation of main pancreatic duct.

In this study we evaluated the effect of secretin administration on the caliber of the Wirsung duct visualized by real-time ultrasonography. A maximal dose [75 clinical units (CU)] of secretin was intravenously injected in 1 min into 18 normal subjects. The duct was continuously monitored from the beginning of injection for a period of 20 min and measured at the level of the body using a calibrated optical lens. The mean caliber of the duct (basal value +/- SD = 1.2 +/- 0.4 mm) markedly increased after secretin stimulation (mean value +/- SD at 3 min = 2.9 +/- 0.8 mm). No dilatation was observed in five of these subjects after administration of 2 ml of saline. In a further four subjects a dose of 0.25 CU/kg/hr of secretin caused a much less marked dilatation of the main pancreatic duct. During dilatation a longer segment of duct is more clearly visualized; furthermore the pancreatic juice within the duodenum improves ultrasonographic imaging of the head of the pancreas.

Adolescent↗

Inhibitory effect of atropine on cholecystokinin-induced gallbladder contraction in man.

We have studied the effect of atropine on cholecystokinin (CCK)-induced gallbladder contraction in 7 healthy volunteers by means of real-time ultrasonography. Two series of tests were carried out in random order and on separate days. In one series of tests, CCK alone was infused for 4 successive 15-min periods at sequentially increasing doses of 0.0021, 0.0042, 0.0084, and 0.0168 Ivy dog units (IDU) X kg-1 X min-1. In the other series of tests, an infusion of a low dose of atropine, 5 micrograms X kg-1 X h-1, was added to the hormone infusion. The smallest dose of CCK which significantly contracted the gallbladder was 0.0042 IDU X kg-1 X min-1. The highest dose of CCK infused, 0.0168 IDU X kg-1 X min-1, produced almost total contraction of the organ. In all subjects, the infusion of atropine completely blocked the gallbladder response to 0.0042 and 0.0084 IDU X kg-1 X min-1, and partially inhibited (by 52%) the response to the highest dose. In 2 subjects in whom a higher dose of atropine, 15 micrograms X kg-1 X h-1, was tested, gallbladder contraction was totally abolished, even when the largest dose of CCK was infused. Contrary to what is generally believed, the results indicate that the response of human gallbladder to CCK is largely dependent on cholinergic innervation.

Adult↗

Anatomical aspects in ultrasonic endoscopy for the stomach.

Gastric wall structure cannot be visualized neither by conventional ultrasonography nor by endoscopy alone. Using a newly developed ultrasonic endoscope (Olympus GF- UM1 / EUM1 Prototype III) twenty-two patients were examined with the stomach filled with 300-500 cc of de- aired water. Ultrasonographic appearance of the normal gastric wall consists of four layers of different echogenicity. The first inner layer, echogenic, seems to correspond to the mucosa and the submucosa, the 2nd echopoor to the muscularis propria, the 3rd echogenic to the serosa and the 4th echopoor to the subserosal-fat. For a complete exploration of the gastric cavity, starting with the scope near the pylorus and withdrawing it until the fundic region, four positions have been standardized. In the first, the antral region is explored, in the 2nd the antrum and the gastric body, in the 3rd the body and antrum and in the 4th position body and fundic region are visualized. For a satisfactory examination a good filling of the stomach must be achieved; problems in interpretation may arise when the gastric wall is not well distended or when peristaltic waves are present. Promising findings have been obtained in 3 cases of cancer involvement of the stomach. No complications were encountered during this study.

Adult↗

Ultrasonic endoscopy--the gastrointestinal wall.

Endoscopic ultrasonography (EUT) allows the visualization of the gastric wall structure. Four and sometimes five distinct layers have been identified. The 1st inner layer echogenic seems to correspond to the mucosa, the 2nd echopoor to the muscularis mucosae, the 3rd echogenic to the submucosa, the 4th echopoor to the muscularis propria and the 5th echogenic to the serosa. In pathological conditions this architecture changes considerably. Infiltration and extension of lesions can be precisely established. Moreover, involvement of neighbouring organs can be preoperatively detected. It is still difficult to establish, only on the EUT data, whether a lesion is benign or malignant. EUT of the stomach is a new method of investigation which can be further developed but already shows a considerable interest.

Adult↗

Ultrasonographic study of portal venous system in portal hypertension and after portosystemic shunt operations.

One hundred sixty patients with portal hypertension were examined by means of ultrasonography in order to evaluate the sensitivity of this technique in the diagnosis of intrahepatic portal hypertension and in the detection of portal vein thrombosis. Thirty-eight of these patients were selected for a portosystemic shunt and were reexamined after operation to assess the value of ultrasonography as a screening test for the patency of surgical portosystemic shunts. In patients with intrahepatic portal hypertension the main ultrasonographic findings observed were dilatation of the portal trunk of more than 1.3 cm (56.6% of cases), patency and dilatation of the umbilical vein (5.8%), presence of intra-abdominal collateral vessels (11.6%), splenomegaly with dilatation of splenic vein radicles at the hilus (91.3%), and disappearance of normal caliber variations during respiration in splenic or mesenteric veins (78.5% and 88.4%, respectively). The disappearance of normal caliber variations proved a highly specific and sensitive finding. Partial or total occlusion of the portal trunk was observed at ultrasonography in 19 of 21 (90.5%) patients with portal vein thrombosis. Surgical portosystemic shunts were displayed in 28 of 37 patients (75.7%). Ultrasonography seems to be the most important noninvasive tool in the diagnosis of portal hypertension. In patients selected for surgical portosystemic shunts ultrasonography supplies morphologic data regarding liver parenchyma and abdominal vascular anatomy, and it should be performed as a routine screening test for assessment of surgical shunt patency.

Humans↗

Ultrasonographic findings in portal hypertension: correlation with the presence and size of oesophageal varices.

This study assesses the usefulness of ultrasonography in the diagnosis of portal hypertension. Several ultrasonographic signs were correlated with the presence and size of oesophageal varices detected by endoscopy in 32 patients suffering from alcoholic liver cirrhosis. Ultrasonography is proposed as a simpler and earlier method for screening of portal hypertension than endoscopy.

Diagnostic Errors↗

The value of ultrasonography in the diagnosis of hepatic haemangiomas.

The following ultrasonographic (U.S.) patterns were observed in 21 cases of proven hepatic haemangiomas: 1) Hyper-echoic (6 cases); 2) Hypo-echoic (4 cases); 3) Complex (11 cases). Several characteristic aspects of the echo structure (uneven appearance and fine internal parallel echoes) and the location of the lesion (para-caval or sub-diaphragmatic) may be useful for differential diagnosis with malignant neoplasia. The U.S. findings of a further 17 cases of hyperechoic focal lesion of the liver are reported. Although a definitive diagnosis was not possible in these subjects, the U.S. characteristics which remained unchanged for over 6 months, made the diagnosis of haemangioma highly likely.

Adult↗