Dynamic sonography of hepatic tumors

OBJECTIVE

Our objectives were to propose and evaluate a dynamic sonography protocol for the characterization of hepatic tumors.

SUBJECTS AND METHODS

The subjects were 107 patients with focal liver lesions that initially had been found on conventional sonograms. The final diagnoses for the lesions were hepatocellular carcinoma in 60 patients, cholangiocellular carcinoma in six, metastatic carcinoma in 24, hemangioma in 10, and focal fat-spared region in seven. The pulse inversion harmonic imaging mode and a galactose-based contrast agent (Levovist) were used. Dynamic sonography was designed to obtain vascular-phase (composed of the arterial phase and the portal phase) images of the focal lesion and liver-parenchymal-phase images of the whole liver in a series obtained after a bolus injection of the contrast agent.

RESULTS

If the whole-tumor or mosaic enhancement patterns (arterial phase) and/or the reticular enhancement (parenchymal phase) are regarded as positive findings for hepatocellular carcinoma, the sensitivity, specificity, and positive predictive value of dynamic sonography in our study were 92%, 96%, and 96%, respectively. If a ring enhancement (arterial to portal phase) or a clear defect (parenchymal phase) or both are regarded as positive findings for cholangiocellular carcinoma or metastasis, the sensitivity, specificity, and positive predictive value were 90%, 95%, and 88%, respectively. If puddle enhancement (portal phase) is regarded as a positive finding for hemangioma, the figures for sensitivity, specificity, and positive predictive value were 60%, 100%, and 100%, respectively. Also, the tumors that showed no focal sign in the liver parenchymal phase were all benign lesions, such as hemangiomas or focal fat-spared regions.

CONCLUSION

Dynamic sonography in a protocol combining pulse inversion harmonic imaging and an IV bolus injection of the contrast agent proved to be an effective tool in characterizing liver tumors.

Evaluation of epithelial cell proliferation rate in normal-appearing colonic mucosa as a high-risk marker for colorectal cancer

To determine whether the colonic epithelial proliferation rate is useful as a marker for colorectal cancer, we measured the Ki-67 labeling index (LI) in normal-appearing mucosa from the sigmoid and ascending colon in patients with two or more tumors (early cancers, which are defined as tumors the depth of invasion of which is limited to mucosal layer or submucosal layer, adenomas, or both). The association of baseline LI with the risk of development of colon tumors 2 years after endoscopic removal was assessed by cohort analysis. The presence of two or more tumors was defined as occurrence. One hundred and six specimens from the sigmoid colon and 130 from the ascending colon from 246 subjects (203 males and 43 females) were used for analysis. The patients with higher upper-third LI in the normal-appearing mucosa in the sigmoid colon, but not in the ascending colon, had significantly more tumors at follow-up colonoscopy 2 years later (risk ratio, 3.6; 95% confidence interval, 1.2-10.6). Moreover, multivariate analysis showed that it was an independent factor. We concluded that the higher upper-third Ki-67 LI of normal-appearing mucosa in the sigmoid colon indicates a high risk for colorectal cancer.

Evaluation of tissue harmonic imaging for the diagnosis of focal liver lesions

This was a prospective study to evaluate tissue harmonic imaging (THI) for the diagnosis of focal liver lesions. A total of 15 reviewers read 100 randomly arranged liver images, a fundamental grey-scale image (FGI) and a THI (transmitted: 2 MHz, received: 4 MHz) of each of 50 patients (29 with liver cirrhosis, 42 with focal lesions) taken from the same section. The mean value of overall accuracy for detecting lesions (presence or absence) was significantly higher with THI (82.3%) than with FGI (79.6%) (t = 1. 96, p< 0.05). When only the 29 cirrhosis patients were analyzed, the difference was more significant (t = 2.48, p < 0.02). The correct count rate of the number of focal lesions was higher with THI (78. 0%) than with FGI (67.0%) (t = 3.61, p< 0.005) in 23 cirrhosis patients with focal lesions. The correct diagnosis of HCC was achieved at a higher rate with THI (42.5%) than with FGI (36.8%). THI was statistically effective for detecting focal lesions, particularly in cirrhotic livers.

Modification of low density lipoprotein potentiates its inhibitory effect on catecholamine secretion in cultured bovine adrenal medullary cells

Low density lipoprotein (LDL) and lipoprotein(a) suppress catecholamine secretion in cultured adrenal medullary cells. Modification of LDL by oxidation or acetylation potentiates various atherogenic actions of LDL. In the present study, we investigated whether the modification of LDL influences catecholamine secretion in cultured bovine adrenal medullary cells. The exposure of LDL to CuSO4 caused a time-dependent oxidation of LDL. Maximal oxidation of LDL was observed after exposure to CuSO4 for 24 h. Native LDL inhibited catecholamine secretion induced by carbachol to 68.5% of control. Oxidized LDL caused further inhibition of carbachol-evoked secretion to 37.6% of control. Acetylated LDL inhibited it to 41.0% of control. There was a good correlation between the extent of LDL oxidation and the inhibition of catecholamine secretion. These results suggest that oxidation or acetylation of LDL augments its inhibitory effect on the secretion of catecholamines. Since catecholamines are a risk factor of atherosclerosis, the inhibitory effect by such modified LDL may be a mechanism inhibiting atherosclerotic progression.

Confirmation of a "safety zone" by intraoperative cholangiography during laparoscopic cholecystectomy

BACKGROUND

Creating a "safety zone" during laparoscopic cholecystectomy is defined as dissection of the cystic duct as close as possible to the gallbladder.

METHODS

In 29 out of 802 cases in which laparoscopic cholecystectomy was difficult to perform due to uncertainty about the orientation of Calot's triangle, intraoperative cholangiography was performed, using a titanium clip as a marker that designated the safety zone. The distance between the clip and the common hepatic duct or the common bile duct could be determined by evaluation of two intraoperative cholangiograms taken in different orientation.

RESULTS

If the clip was located in the safety zone, and was distant from the common hepatic duct or common bile duct, the safety of preparation around the clip was ensured. No complication was encountered in these cases with this method. Eventually, no biliary tract injury was experienced, and the overall conversion rate to open cholecystectomy was only 0.4% (3 of 802 consecutive cases).

CONCLUSIONS

This method of confirming the safety zone by intraoperative cholangiography is a useful procedure for avoiding inadvertent injury to the biliary tract.

Laparoscopic transcystic cholangioscopic lithotripsy for common bile duct stones during laparoscopic cholecystectomy

BACKGROUND AND STUDY AIMS

Following the recent introduction of laparoscopic cholecystectomy (LC) for cholecystolithiasis, treatment of concomitant common bile duct (CBD) stones has been evaluated by using laparoscopic choledochotomy, a transcystic approach, or by means of endoscopic sphincterotomy (ES) before or after LC.

PATIENTS AND METHODS

During laparoscopic cholecystectomy, we attempted lithotripsy of CBD stones using laparoscopic transcystic cholangioscopy with lithotripsy (LTCL), in 70 patients out of 950 laparoscopic cholecystectomies. Preparatory tests included laboratory values, ultrasound, and performance of endoscopic retrograde cholangiography (ERC) with placement of a nasobillary tube (without sphincterotomy).

RESULTS

Introduction of the cholangioscope into the CBD was successful in 65 patients (92.9%) and CBD clearance was completely achieved by LTCL alone in 51 (78.5%). The overall success rate was therefore 73%. The remaining 19 cases required postoperative procedures such as extracorporeal shock-wave lithotripsy without ERC or ES (successful in all). The average hospital stay period was 9.4 days for patients in whom CBD clearance was achieved by LTCL alone. This period did not differ significantly from that of patients who underwent LC alone (8.4) days. The operation time was about 70 minutes longer for the LTCL group (total time 174 minutes on average) than for the LC group (107 minutes). We did not observe any series complications during or after LTCL (mean follow-up period: 34 months).

CONCLUSION

LTCL in combination with LC allows shortening of the hospital stay and a swift return to work for patients with CBD stones. This procedure also preserves the function of the sphincter of Oddi, so that the longterm prognosis for patients is likely to be very good.

Laparoscopic cholecystectomy in the elderly: analysis of pre-operative risk factors and postoperative complications

A retrospective study was conducted of two groups of patients over (group 1, n = 57) and under (group 2, n = 655) the age of 70 years who underwent laparoscopic cholecystectomy (LC). The pre-operative physical status and systemic complications, operation time, postoperative complications, postoperative hospital stay and other clinical features of the two groups were compared. The incidence of pre-operative complications in group 1 was significantly higher than that in group 2 (P < 0.05). Postoperatively no severe complication was found in any patient. Group 1 showed significantly prolonged operation time and postoperative hospital stay compared with group 2 (P < 0.05). The difference between the groups in the intra-operative treatment time and postoperative treatment is attributed to the greater prevalence of common bile duct stone in group 1 as there was little difference between the groups in the postoperative recovery after exclusion of these patients. No pulmonary complications, which are associated with LC, were observed; the postprocedure pain was slight and the period of bedrest was short. If complications associated with pneumoperitoneum can be prevented, this surgery is an excellent measure to improve the quality of life of even elderly patients with cholecystolithiasis.

Femoral vein stasis during laparoscopic cholecystectomy: effects of graded elastic compression leg bandages in preventing thrombus formation

Venous stasis of the legs during laparoscopic cholecystectomy was compared between patients without graded compression leg bandages (Group 1; n = 12) and patients with such bandages (Group 2; n = 12) by measuring mean blood flow velocity and cross-sectional area of the femoral vein using a color Doppler ultrasonography. In Group 1, when velocity and area were measured in the supine position, a significant decrease in velocity (p < .05) and a significant increase in area (p < .05) occurred after abdominal insufflation to 10 mm Hg. These changes were greater during abdominal insufflation in the reverse Trendelenburg position than during abdominal insufflation in the supine position. In Group 2, flow velocity was significantly higher (p < .05) before abdominal insufflation as compared with Group 1. After abdominal insufflation to 10 mm Hg and a postural change, velocity significantly decreased (p < .05) and area significantly increased (p < .05) in Group 2, similar to the results in Group 1. During abdominal insufflation at 5 mm Hg or lower, the use of the graded compression bandage was found to be useful for preventing femoral vein stasis. During abdominal insufflation at 10 mm Hg or in the reverse Trendelenburg position, the bandage did not prevent femoral vein stasis.

Lower-extremity venous stasis during laparoscopic cholecystectomy as assessed using color Doppler ultrasound

Lower-extremity venous stasis during laparoscopic cholecystectomy was evaluated in 16 patients by monitoring the blood velocity in the femoral vein and the femoral vein size (cross-sectional area) using color Doppler ultrasonography. The blood velocity in the femoral vein decreased significantly after the start of 10-mmHg abdominal insufflation in the supine position. When the patients were placed in a reverse Trendelenburg position during 10-mmHg insufflation, blood velocity in the femoral vein further decreased. However, velocity returned to the baseline after deflation. The cross-sectional area of the femoral vein was significantly elevated after the start of 10 mm Hg insufflation in the supine position. When patients were placed in the reverse Trendelenburg position during 10-mmHg insufflation, this parameter was further elevated, but returned to the baseline soon after deflation. These results indicate that femoral vein stasis during laparoscopic cholecystectomy can be minimized by reducing the pressure of abdominal insufflation and avoiding elevation of the patient's head as much as possible.