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Biomedical subjects

A Mazziotti

Publications and source records attributed to A Mazziotti.

At least 91 records · Page 5Linked to original sources
PubMed1986

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↗
PubMed1984

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↗
PubMed1981

[Control of the patency of porto-systemic anastomoses].

After having discussed the direct and indirect methods to control the patency of porto-systemic anastomoses, the Authors report on their series of 42 cases (28 side-to-side porto-cava shunts, 6 end-to-side porto-cava shunts, 6 spleno-renal shunts, 2 mesenterico-cava shunts) where the postop. control was carried out with portography, hepatic superselective arteriography in 29 cases, transcaval catheterism of the anastomosis in 6 patients, and pre-op., and post-op. echotomography in 15 cases. Portography revealed 39 cases of patent anastomosis and thrombotic occlusion in 3 cases. The typical sign of shunt patency is the visualisation of the inferior V.C. and the less frequent disappearance of right gastric reflux. Furthermore the investigations consented the evaluation of altered post-shunt hepato-portal flow: side-to-side porto-cava shunt (25 patent anastomoses) revealed a complete deviation of portal glow towards the I.V.C. and in 15 cases there was inverted portal flow; portography after splenorenal shunt (5 cases of patent anastomosis) showed a preserved hepatopetal portal flow only in early controls (7 days) while in all long term controls it was hepatofugal. In 13 cases the morphology of the hepatic arterial system was compared before and after surgery; in 12 cases the hepatic artery was larger and its intrahepatic branches more tortuous after surgery Ultrasonography revealed only 8 patent shunts out of 15 examined since the amount of gas in the bowel rendered the exam technically insufficient.

Adult↗
PubMed1981

Plasma amino acid patterns in experimental acute hepatic failure: comparison between hepatectomy and liver devascularization in pigs.

To clarify the physiopathologic mechanism leading to a marked increase in aromatic amino acids (AAA) in acute hepatic failure (AHF), we compared two experimental models of AHF. Ten pigs were submitted to one-stage hepatic devascularization (group A); in eight other pigs total hepatectomy was performed (group B). The animals were maintained under constant glucose infusion. The mean survival time in group A was 23 +/- 2 hours; after hepatectomy it was 30 +/- 4 hours. Hepatic coma progressively deepened from 8 +/- 3 hours in Group A animals and was delayed until 17 +/- 5 hours in the anhepatic pigs. AAA, methionine, and tryptophan immediately increased markedly in pigs with liver ischemia. In group B animals, AAA showed a slight increase only 18 hours after hepatectomy, whereas there were no significant differences in methionine and tryptophan. The different amino acid patterns in the two groups of animals demonstrate that hepatocyte necrosis is a major source of plasma amino acids after liver devascularization. The slight increase in AAA after total hepatectomy suggests that a release mechanism from muscular mass is involved in the later stages of the experiment. The onset of coma is related to the increase in AAA rather than to alterations in blood ammonia that did not differ in either group of animals.

Amino Acids↗
PubMed1980

[Hepato-portal circulatory changes after splenorenal anastomosis].

Hepatoportal circulation changes after the shunt were examined angiographically in 5 patients subjected to splenoportal anastomosis and splenectomy. Arterioportography was employed in all cases. Catheterisation of the anastomosis was carried out in 1 patient and suprahepatic phlebography in another. The anastomosis was found to be patent in all cases. A hepatopetal portal flow was noted solely in the two patients examined six days after surgery. Disappearance of hepatic portal perfusion was observed in one of these patients on the 15th postoperative day. Controls carried out one month, one year, and five years after the operation showed that the mesenteric-portal flow was fully deviated through the shunt towards the vena cava in all patients. Selective hepatic arteriography showed an inverted portal flow in 3 patients. An increase in the calibre of the trunk of the hepatic artery and the entire intrahepatic artery network was always present.

Adult↗
PubMed1980

[Hepatoportal circulatory modifications after splenorenal anastomosis (author's transl)].

An angiographic study was performed in five patients following splenorenal anastomosis with splenectomy, to evaluate hepatoportal circulatory modifications after surgery. All cases had angiographic investigations by arterioportography. In one case catheterization of the anastomosis was also associated and in another case hepatic phlebography. Hepatopetal blood flow was observed in only two patients examined within 6 days of the operation. In one of these cases a second angiographic examination was made 10 days later and demonstrated that hepatopetal portal flow had disappeared. In the other patients, examined after one month, one year, and five years respectively, the mesenteric blood flow was completely deviated through the anastomosis towards the inferior vena cava, without any opacification in the portal vein. In three patients, selective hepatic arteriography showed inversed portal flow. All late investigations demonstrated a great increase of hepatic artery size and of the intrahepatic arterial branches.

Celiac Artery↗
PubMedDate not supplied

Morphological and hemodynamic changes in the portal venous system after distal splenorenal shunt: an ultrasound and pulsed Doppler study.

We investigated a group of patients who underwent distal splenorenal shunt using high-resolution real-time equipment and a duplex scanner with the aims: (i) to evaluate the rate of visualization of shunt; (ii) to assess change in size in the portal vein, and (iii) to characterize the flow pattern in the splenic vein and to study flow direction and velocity in the portal vein, thus adding new data on the efficacy of this operation in maintaining hepatic perfusion. Real-time ultrasonography was performed in 29 patients before surgery, after 7 to 30 days and after 4 to 12 months. Direct visualization of the shunt was achieved in 53.5% of the patients. Mean caliber of the portal vein significantly decreased after the operation: preoperative = 1.52 +/- 0.32; after 7 to 30 days = 1.32 +/- 0.16 (p less than 0.001), and after 4 to 12 months = 0.99 +/- 0.19 (p less than 0.001). The overall postoperative incidence of portal thrombosis was 22.2%. Thirteen of these patients also underwent a postoperative (4 to 36 months) pulsed Doppler investigation. Flow towards anastomosis was demonstrated in the splenic vein in 11 patients, and in 7 cases, typical caval pulsatility was observed. Decreased hepatopetal flow in the portal vein was found in 10 of 13 patients. In two patients, no flow was detectable and in the other the flow was hepatofugal. On the basis of our data, we can affirm that pulsed Doppler investigation may provide useful data for the evaluation of shunt patency and preservation of a decreased portal hepatic perfusion in the majority of patients.

Adult↗