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Biomedical subjects

N Koyanagi

Publications and source records attributed to N Koyanagi.

At least 55 records · Page 3Linked to original sources
PubMed1988

Lack of preventive effect of branched-chain amino acid solution on postoperative hepatic encephalopathy in patients with cirrhosis: a randomized, prospective trial.

The purpose of this randomized, prospective study was to determine whether the infusion of branched-chain amino acid (BCAA)-enriched solution had a preventive effect for treating postoperative hepatic encephalopathy in patients with cirrhosis. Among the 56 patients with cirrhosis, 29 were given BCAA-enriched solution, and 27 were given the conventional amino acid solution for 14 days postoperatively. These groups were indistinguishable with regard to clinical and laboratory criteria at entry, except by sex. The molar ratio of BCAA to aromatic amino acids in the BCAA group was increased postoperatively, whereas the ratio in the control group was decreased, the difference being statistically significant. Among the 29 who received BCAA, three (10.3%) had hepatic encephalopathy; two died and one recovered. Of the 27 control patients, hepatic encephalopathy occurred in three (11.1%); one died and two recovered. There was no significant difference in rate of occurrence of hepatic encephalopathy between the groups. Thus the infusion of BCAA-enriched solution apparently had no preventive effect with regard to hepatic encephalopathy for patients with cirrhosis who underwent surgical treatment.

Amino Acids↗
PubMed1988

An ultrasonic duplex system facilitates detection of portal hemodynamic changes following selective shunts for esophageal varices.

We used an ultrasonic duplex system (US system) to assess portal hemodynamics in 52 patients with liver cirrhosis and esophageal varices, who underwent 2 types of distal splenorenal shunt (DSRS), conventional DSRS (group A, 8 patients) or DSRS with splenopancreatic disconnection (group B, 44 patients). The portal blood flow rate (PBF) was determined in 64 out of 70 patients (91.4%) and the shunt flow rate (SVF) in 39 out of 42 patients (92.9%) who had angiographically confirmed patent portal vein and shunt vein, during the peri- and postoperative period. In group A, a remarkably small amount of postoperative PBF (193 ml/min) and a concomitant increase in SVF (1039 ml/min) were evident. Such ultrasonic findings were compatible with a reduction in portal vein diameter, in accordance with the poor portal perfusion grade of the liver, and a transpancreatic stealing of the portal blood flow to the shunt, as evidenced by postoperative angiography. In contrast, the reduction in PBF was minimal, that is 663 ml/min preoperatively to 562 ml/min at discharge, and 536 ml/min at late follow-up, in group B patients. Significant alterations in portal circulation of the group B patients were not evident angiographically. This US system is most useful to assess portal hemodynamics in patients with a selective shunt.

Adult↗
PubMed1987

Prospective randomized trial comparing two injection techniques for sclerosing oesophageal varices: over-tube and free-hand.

The safety, efficacy and complications of two techniques of endoscopic injection sclerotherapy were examined in 102 consecutive patients, using either a totally transparent over-tube or the free-hand technique. The choice of treatment was at random. There was a significantly higher control of variceal bleeding when the over-tube technique was used (100 per cent versus 77 per cent, P less than 0.05). The frequency of re-bleeding before the eradication of oesophageal varices was significantly less in the over-tube group than in the free-hand group (P less than 0.01), although all re-bleedings were well controlled with additional injections of 5 per cent ethanolamine oleate. There was no significant difference between the two techniques with regard to the frequency of endoscopic injection sclerotherapy for eradication of oesophageal varices. The over-tube technique is safer than the free-hand technique and takes less time to accomplish; at the initial session of treatment, time and bleeding during these techniques were 11.5 +/- 2.3 min (mean +/- s.d.) and 7.3 +/- 5.9 ml in the over-tube technique, and 20.4 +/- 4.1 min and 45.1 +/- 30.0 ml in the free-hand technique (P less than 0.001, in both time and bleeding).

Esophageal and Gastric Varices↗
PubMed1987

Validity of ultrasonic duplex system for measurement of the portal blood flow in patients with liver disease.

The validity of an ultrasonic duplex system for assessment of portal blood flow was clinically investigated. The maximum portal blood flow velocity was measured using this system (X) in ten patients with liver disease, and data obtained were compared on patients simultaneously undergoing cineangiographic mapping of Lipiodol droplets released into the portal vein through an indwelling catheter (Y). A linear correlation between X and Y was statistically significant (r = 0.970, n = 13). The ultrasonic duplex system proved reliable for a quantitative assessment of portal hemodynamics.

Humans↗
PubMed1987

A transparent over-tube for endoscopic injection sclerotherapy and results in patients with esophageal varices.

This report describes our data regarding repeated injection sclerotherapy using a newly designed over-tube. We treated 17 consecutive patients with esophageal varices, (3 acute, 6 elective and 8 prophylactic). An intravariceal injection of 5 per cent ethanolamine oleate was administered, using a newly designed transparent over-tube containing a second lumen for a flexible injection needle. This over-tube provides an easier, safer, shorter-in-time method of sclerosing esophageal varices. One of the 17 patients died as a result of liver failure associated with advanced cirrhosis and a concomitant hepatoma. Eradication of esophageal varices was attained in the remaining 16 patients, after an average of 5.0 injections over an average period of 5.8 weeks (range: 3-7 injections during 3-11 weeks). No complications, such as esophageal perforation or aspiration pneumonia were encountered. Recurrent variceal bleeding has not occurred during the 9 months follow-up.

Adult↗
PubMed1987

Ultrasonic duplex system to facilitate assessment of portal blood flow velocity.

The usefulness of an ultrasonic duplex system to assess portal blood flow was investigated. In a model involving a steady flow through a vinyl tube in agar, there was a significant linear correlation between the maximum blood flow velocity measured by this system (V-max) and the mean blood flow velocity calculated from the actually measured blood flow volume (V-mean), that is, V-mean = 0.53 X V-max was obtained (r = 0.994; n = 47). This equation was used to calculate the mean portal blood flow velocity by this system (V-dopp) in 10 patients with liver disease, and the findings were compared with data simultaneously obtained by cineangiographic mapping of Lipiodol droplets released into the portal vein through a catheter placed in situ at the time of surgery (V-cine). A linear correlation between V-dopp and V-cine was statistically significant (r = 0.970; n = 13), and the regression line was V-cine = 1.29 X V-dopp -2.11. The ultrasonic duplex system proved reliable for a quantitative assessment of portal hemodynamics.

Blood Flow Velocity↗
PubMed1987

Ethanolamine oleate is superior to polidocanol (aethoxysklerol) for endoscopic injection sclerotherapy of esophageal varices: a prospective randomized trial.

Thirty-four consecutive patients with liver cirrhosis and esophageal varices were included in a prospective randomized trial done to investigate the efficacy and safety of two sclerosants 5% ethanolamine oleate (EO) and polidocanol (1% Aethoxysklerol [AS]) for use in endoscopic injection sclerotherapy (EIS). Eighteen patients were randomly allocated to the group given EO and 16 to the AS group. These two groups were comparable with regard to age, sex, etiology and severity of the liver disease. The bleeding rate from esophageal ulcers which developed during the course of repeated EIS was significantly (P less than 0.05) higher in the AS group (31.3%, 5/16) than in the EO group (0%, 0/18). In 4 occasions bleeding from the esophageal ulcer could not be controlled with AS. In 3 of these 4 bleeding episodes, EO successfully halted bleeding from esophageal ulcer. In the other patient, a Sengstaken-Blakemore tube was inserted to stop the hemorrhage. The period and number of sessions of EIS for eradication of esophageal varices were significantly (P less than 0.05) shorter in the EO group than the AS group (EO: 4.0 +/- 0.8 [means +/- SD] sessions during 4.7 +/- 1.5 weeks versus AS: 4.8 +/- 1.2 sessions during 5.4 +/- 1.6 weeks). The rate of early mortality did not differ between the two groups. We conclude that 5% ethanolamine oleate seems to be superior to 1% Aethoxysklerol when used for sclerosing esophageal varices.

Clinical Trials as Topic↗
PubMed1986

Development of erosive gastritis in a canine model of esophageal varices.

We designed a reproducible canine model of esophageal varices, based on the concept of a regional hyperdynamic state in the upper stomach. Arterialization of the left gastric vein concomitant with the distal splenorenal shunt led to a stable hyperdynamic state and reproducible esophageal varices occurred. In the long-term follow-up of these dogs with varices, the erosive gastritis seen in the upper stomach clearly resembled clinically observed lesions. Hemodynamic and morphological studies revealed that gastric mucosa of these animals was in an ischemic state, even though there was a remarkable increase in blood flow in the submucosal area. It is suggested that the decrease in mucosal blood flow, as induced by the hyperdynamic state caused erosive gastritis.

Animals↗
PubMed1986

Eradication of esophageal varices with repeated injection sclerotherapy in inoperable patients.

Esophageal varices in 50 cirrhotic patients were treated with repeated injection sclerotherapy. Eradication of varices was achieved in 27 patients (54.0%) with a mean of 4.5 injections (range 2-12) after a mean period of 3.1 months (range 1-11). There was no variceal bleeding in these 27 patients once eradication had been achieved, with a mean follow up period of 5.6 months, although bleeding occurred in 5 of the same group before eradication of the varices had been achieved, during an average of 3.1 months, and in 6 of the remaining 23 patients (10 episodes) with residual varices after a mean of 4.7 injections (range 2-12) in a mean period of 12.2 months (range 1-33). Esophageal varices can thus be eradicated with repeated injections and bleeding from recurrent esophageal varices can be prevented in many patients after eradication has been achieved.

Adult↗
PubMed1985

Hyperdynamic circulation in the left gastric venous area in patients with portal hypertension: angiological assessment.

The time of appearance of the left gastric vein on serial celiac arteriograms in patients with portal hypertension and esophageal varices was compared with that of the portal vein to assess regional hemodynamics in the left venous portion of the stomach, an area located in close proximity to the varices. In two thirds of all the patients with cirrhosis or non-cirrhotic idiopathic portal hypertension (IPH), the left gastric vein was visualized earlier or simultaneously than or with the portal vein, while in all but one patient with prehepatic portal obstruction, there was a delayed opacification of the left gastric vein. These results suggest the presence of a hyperdynamic circulatory state which promotes venous hypertension in the left gastric venous area of the stomach of a considerable number of patients with cirrhosis or IPH. In such a hemodynamic state, selective decompression of varices can be achieved by a left gastric venous caval shunt.

Esophageal and Gastric Varices↗
PubMed1985

Esophageal varices produced in dogs.

In attempts to produce esophageal varices in dogs, we designed a procedure based on the concept of hyperdynamic flow. The first stage operation involved the achievement of an arteriovenous shunt between the left renal artery and the proximal splenic vein, in concert with the distal splenic venous-left renal venous shunt. About one month after the initial operation, sixteen of the twenty-eight dogs had tolerated the manipulations. Both shunts proved to be functioning well in six of sixteen survivors, in which an ameroid constrictor was placed around the splenic vein just proximal to the confluence of the left gastric vein. Again one month later, in five of these six, esophageal varices were evidenced, both endoscopically and histologically. Arterialization of left gastric vein concomitant with the distal splenorenal shunt, gave rise to a hyperdynamic state in the upper stomach and resulting in reproducible esophageal varices.

Animals↗
PubMed1985

Increased blood flow in the stomach of cirrhotic patients as assessed by radionuclide angiography.

To assess the gastric hemodynamics of patients with cirrhosis of the liver, radionuclide angiography of the left gastric artery, using technetium-99m-labeled human serum albumin (99mTc-HSA), was performed in 13 cirrhotics and 4 control subjects. The half-life (T1/2) of radioactivity of the stomach was significantly shorter in cirrhotics than in controls, 7.1 +/- 2.2 s (+/- SD, n = 13) and 14.1 +/- 3.4 s (+/- SD, n = 4), respectively (p less than 0.001). Accordingly, the calculated blood flow per unit plasma volume of the stomach of cirrhotics was significantly increased compared with that of controls, 6.4 +/- 1.9 ml/min (+/- SD, n = 13) and 3.1 +/- 0.8 ml/min (+/- SD, n = 4), respectively (p less than 0.01). These results provide direct evidence that a hyperdynamic state exists in the gastric circulation of cirrhotic patients.

Angiography↗
PubMed1984

Exclusion of nonisolated splenic vein in distal splenorenal shunt for prevention of portal malcirculation.

In an attempt to prevent portoprival malcirculation after distal splenorenal shunt (DSRS), a splenic hilar renal shunt (HRS) with proximal flush ligation of splenic vein was designed. To accomplish this procedure, two methods were compared: HRS alone (Group A) and HRS plus proximal flush ligation of the splenic vein (Group B). In Group A, which included 20 cirrhotic patients with esophageal varices, angiographic as well as pulsed Doppler flowmetric follow-up study revealed a portal thrombosis in two patients and severe narrowing of a portal vein in another two. Considerable stealing flow was observed in these four patients. In the Group B series, which included 33 cirrhotic patients, there were no gross changes in the portal hemodynamics. Normal prograde portal flow was confirmed by Doppler flowmeter in this series including 14 patients of more than 8 months after surgery. When the amount of nonisolated splenic vein embedded in the pancreas is minimized, portal malcirculation after distal splenorenal shunt can, to a great extent, be prevented.

Collateral Circulation↗
PubMed1984

The natural history of non-alcoholic cirrhosis.

To assess the natural history of non-alcoholic liver cirrhosis, one hundred and eighty medically treated Japanese cases, including 110 accompanied by esophageal varices were investigated retrospectively. Among those patients with varices fifty-one (46.4%) bled from the upper gastrointestinal (GI) tract and thirty-two (29.1%) from esophageal varices, while GI bleeding was found in only six out of 70 patients without varices. The GI bleeding rate was the highest in patients with varices and concomitant hepatoma (76.5%). The mortality rate of the GI bleeders was 68.6% in patients with varices and 33.3% in patients without varices. The mortality on the first variceal bleeding episode was 65.6%, and another 25.0% had rebleeding from varices, resulting in a one-year survival of 9.4%. The ten-year cumulative percentage of variceal bleeding was 61.2% in patients with varices, and that of occurrence of hepatoma was 50.7% in total of 180 patients. This study revealed that the non-alcoholic cirrhotic patients have a highly rate of complication by hepatoma and that the development of hepatoma doubles the risk of varix rupture.

Adult↗
PubMed1982

Mucosal blood flow and modified vascular responses to norepinephrine in the stomach of rats with liver cirrhosis.

To observe changes in hemodynamics and vascular responses to norepinephrine in cases of liver cirrhosis, male WKA rats were given CCl4 subcutaneously. The portal venous pressure of these so-induced cirrhotic rats was significantly higher than that of the controls. There was an increase of mucosal blood flow and a lowering of peripheral vascular resistance of the stomach. After norepinephrine infusion, the gastric mucosal blood flow increased significantly in cirrhotic rats, whereas there was no significant change in controls. The aorta and the portal vein showed no difference in the vascular response to either norepinephrine or [K+].0. These results suggest that in cirrhotic rats there is an increase in blood flow and a lowering of peripheral vascular resistance in the gastric mucosa and that these hemodynamic changes may be derived from alteration in the vascular response to norepinephrine in gastric microcirculation.

Animals↗