Doppler color flow imaging in the detection and quantitative measurement of the gastroduodenal artery blood flow

Liver Function, Quantified by LiMAx Test, After Major Abdominal Surgery. Comparison Between Open and Laparoscopic Approach

INTRODUCTION

Major abdominal surgery may lead to a systemic inflammatory response (SIRS) with a risk of organ failure. One possible trigger for a postoperative hepatic dysfunction is an altered hepatic blood flow during SIRS, resulting in a decreased oxygen delivery. This pilot study investigated the role of liver dysfunction measured by the LiMAx test after major abdominal surgery, focussing on open and laparoscopic surgical approaches.

METHODS

We prospectively investigated 25 patients (7 females and 18 males, age range 55-72 years) scheduled for upper abdominal surgery. The LiMAx test, ICG-PDR and duplex sonography were carried out preoperatively, followed by postoperative days (PODs) 1, 3, 5 and 10. Laboratory parameters and clinical parameters were measured daily. Clinical outcome parameters were examined at the end of treatment. The population was divided into group A (laparotomy) versus group B (laparoscopy).

RESULTS

LiMAx values decreased significantly on POD 1 (290 µg/kg/h, P < 0.001), followed by a significant increase at POD 3 (348 µg/kg/h, P = 0.013). Only INR showed a significant increase on POD 1 (1.26, P < 0.001). Duplex sonography and ICG-PDR revealed a hyper-dynamic liver blood flow. No differences between group A and B were found.

CONCLUSIONS

Hepatic dysfunction after major abdominal surgery is evident and underestimated. The LiMAx test provides an adequate tool to determine liver dysfunction. Open and laparoscopic approaches appeared similar in terms of liver dysfunction and postoperative SIRS.

Sonographic assessment of splanchnic arteries and the bowel wall

The intestinal wall can be visualized using high resolution transabdominal ultrasound. The normal intestinal wall thickness in the terminal ileum, cecum, and right and left colon is <2mm when examined with graded compression. It is important to appreciate that a contracted intestinal segment can be misinterpreted as a thickened wall. Vascularisation can be mainly displayed in the second hyperechoic layer (submucosal layer) as well as vessels penetrating the muscularis propria. Imaging of the gastrointestinal wall is dependent on the experience of the examiner as well dependent on the equipment used. Acute or chronic inflammation of the intestinal wall is accompanied by increased perfusion of the mesentery, which can be displayed non-quantitatively with colour duplex. In contrast, ischemia is characterised by hypoperfusion of the mesenteric arteries and the bowel wall. The most promising sonographic approach in assessing splanchnic arteries and the bowel wall is combining the analysis of superior and inferior mesenteric inflow by pulsed Doppler scanning (systolic and diastolic velocities, resistance index) with the end-organ vascularity by colour Doppler imaging diminishing the influence of examination technique only displaying bowel wall vascularity. Colour Doppler imaging has been described as helpful in a variety of gastrointestinal disorders, particularly in patients with Crohn's disease, celiac disease, mesenteric artery stenosis and other ischemic gastrointestinal diseases, graft versus host disease and hemorrhagic segmental colitis.

Evaluation of blood flow in pancreatic ductal carcinoma using contrast-enhanced, wide-band Doppler ultrasonography: correlation with tumor characteristics and vascular endothelial growth factor

BACKGROUND AND AIMS

Tumor vascularization has been attracting attention. However, there have been only a few reports on tumor vascularization in pancreatic ductal carcinoma, especially on vascularization depicted by imaging modalities. We investigated the relationship among wide-band Doppler signals, clinicopathological factors, and vascular endothelial growth factor (VEGF) expression.

METHODS

Sixty-nine patients with pancreatic ductal carcinoma were investigated. The vascular signals from carcinoma lesions were assessed by contrast-enhanced, wide-band Doppler ultrasonography (dynamic flow). VEGF expression was quantitated by enzyme immunoassay for 28 patients. Depending on the intensity of the signals, the patients were classified into type A (definite vascular signal) or type B (almost no vascular signal).

RESULTS

Type A patients and type B patients accounted for 65% and 35% of patients, respectively. According to multivariate analysis of vascular signal type and clinicopathological factors, liver metastasis occurred significantly more frequently in the type A group. VEGF expression was also significantly higher in the type A group than in the type B group.

CONCLUSIONS

Dynamic flow has very high sensitivity for detecting the vascular signals from pancreatic ductal carcinoma. The quantity of vascular signals correlated with tumor characteristics and VEGF.

Visualization of blood flow in hepatic vessels and hepatocellular carcinoma using B-flow sonography

PURPOSE

A B-flow sonographic technique was recently developed to provide direct visualization of blood flow with gray-scale sonography. Compared with color Doppler sonography, B-flow imaging has wideband resolution and a high frame rate. The purpose of this study was to evaluate the usefulness of B-flow sonography for visualizing blood flow in hepatic vessels and tumor vascularity in patients with liver cirrhosis or hepatocellular carcinoma (HCC).

METHODS

Twenty-five patients with liver cirrhosis, including 15 with HCC, were studied by B-flow and color Doppler sonography. Blood-flow detection rates in portal veins and hepatic arteries and tumor vascularity in HCC were analyzed, and the 2 methods were compared.

RESULTS

Using B-flow, blood flow was visualized in the portal vein in 23 (92%) of 25 patients and was visualized in the hepatic artery separately from the portal vein in 9 (36%) of 25 patients. The blood-flow signals were visualized only within vessels, never "bleeding" outside the vessel's lumen. Blood flow in the portal vein was observed with color Doppler sonography in all 25 patients, but the hepatic artery was never clearly separated from the portal vein. Vascularity within the HCC tumor was detected in 9 (60%) of 15 nodules with B-flow imaging, and fine arteries flowing into the tumor were observed in 6 nodules. Color Doppler sonography detected blood flow in 13 (87%) of the 15 HCC nodules.

CONCLUSIONS

Blood flow in hepatic vessels and tumor vessels of HCC were visualized with B-flow sonography. B-flow sonography is a potentially useful technique for the evaluation of liver vascularity and intratumoral vessels.

Diagnostic value of Doppler ultrasound in the assessment of liver cirrhosis in children: histopathological correlation

We have correlated flow abnormalities in the hepatic vasculature with histological findings in the liver to determine the accuracy of Doppler ultrasound in the diagnosis of liver cirrhosis in children. Eighteen children admitted for evaluation of unknown liver disease were examined prospectively and blindly with Doppler ultrasound prior to liver biopsy. Biopsy specimens showed established cirrhosis in 9 of 18, early cirrhosis in 5 of 18, and no cirrhosis in 4 of 18 children. Doppler studies were also performed on 20 control subjects. The portal vein velocity was decreased (p < 0.0005) and the arterio-portal velocity ratio was increased (p < 0.0005) in the established cirrhosis cohort relative to the controls. For the criteria of the established cirrhosis cohort, the sensitivities of the loss of the reverse flow component in the hepatic veins, the arterio-portal velocity ratio being greater than 3.0, the portal vein velocity being less than 20 cm/s, and the existence of focal flow acceleration in the hepatic veins were 100%, 78%, 67%, and 44%, respectively. The specificity of all these criteria was 100%. The indicators were not useful in the diagnosis of early cirrhosis.