Yulri Park

Differential diagnosis for intrahepatic biliary cystadenoma and hepatic simple cyst: significance of cystic fluid analysis and radiologic findings.

Goals This study evaluated the significance of cystic fluid analysis and radiologic findings in the differential diagnosis of biliary cystadenomas (BCA) and hepatic simple cysts (HSCs). Background BCA are premalignant lesions. The treatment of choice is surgical excision. It is important to differentiate BCA from HSCs because they have different clinical significances and treatment plans. However, it is difficult to preoperatively differentiate a BCA from a HSC. Study This retrospective study was done with 31 patients suffering from pathologically diagnosed BCA or HSC. All patients underwent surgery between May 1995 and June 2008 at a single institution and had cystic fluid analysis preoperatively or intraoperatively. Results We discovered no statistically significant differences in cystic fluid carbohydrate antigen 19-9 (CA 19-9) levels or carcinoembryonic antigen levels when comparing BCA (n=17) and HSCs (n=14). BCA were significantly more frequently associated with female sex (17/17 vs. 10/14, P=0.032), presence of a septum (16/17 vs.5/14, P=0.001), and septal thickening (8/17 vs. 1/14, P=0.021). All 3 cases with calcifications belonged to the BCA group, but sample size was too small to demonstrate statistical significance. There were no statistically significant differences in other clinical and radiologic findings including age, presence of symptoms, serum tumor markers, serum chemistry, size, location, lobulation, septal enhancement, wall enhancement, wall thickening, mural nodule, or biliary dilatation. Conclusions Cystic fluid carbohydrate antigen 19-9 levels and carcinoembryonic antigen levels were not useful for differential diagnosis of BCA vs. HSC. BCA were more common than HSCs in females, patients with a septum, and patients with septal thickening.

Gadoxetic Acid (Gd-EOB-DTPA)-Enhanced MRI versus Gadobenate Dimeglumine (Gd-BOPTA)-Enhanced MRI for Preoperatively Detecting Hepatocellular Carcinoma: an Initial Experience

Objective This study was designed to compare the diagnostic performance of gadoxetic acid-enhanced magnetic resonance imaging (MRI) with gadobenate dimeglumine-enhanced MRI for preoperatively detecting hepatocellular carcinoma (HCC). Materials and Methods Eighteen consecutive patients (17 men and one woman, age range: 31-73 years) with 22 HCCs underwent examinations with gadoxetic acid enhanced MRI and gadobenate dimeglumine-enhanced MRI on a 3.0-Tesla unit. The diagnosis of HCC was established after surgical resection and pathological conformation. Three observers independently reviewed each MR image in a random order on a tumor-by-tumor basis. The diagnostic accuracy of these techniques for the detection of HCC was assessed by performing an alternative free-response receiver operating characteristic (ROC) analysis. The sensitivity and positive predictive values were evaluated. Results The average value of the area under the ROC curve (Az) for gadoxetic acid enhanced MRI (0.887) was not significantly different from the Az (0.899) for gadobenate dimeglumine-enhanced MRI (p > 0.05). The overall sensitivities of gadoxetic acid enhanced MRI and gadobenate dimeglumine-enhanced MRI were 80% and 83%, respectively, with no significant difference (p > 0.05). The differences of the positive predictive values for the two contrast agents for each observer were not statistically significant (p > 0.05). Conclusion The diagnostic performance of gadoxetic acid-enhanced MRI and gadobenate dimeglumine-enhanced MRI for preoperatively detecting HCC is quite similar.

Biloma formation after radiofrequency ablation of hepatocellular carcinoma: incidence, imaging features, and clinical significance.

OBJECTIVE The objective of our study was to evaluate the frequency, morphologic patterns, temporal changes, and clinical significance of biloma after radiofrequency ablation (RFA) of hepatocellular carcinoma (HCC). MATERIALS AND METHODS Between April 1999 and May 2008, 2,630 patients with HCC underwent a total of 3,284 sessions of RFA at our institution. We retrospectively reviewed all CT scans obtained before and after RFA in all patients. The frequency, morphologic patterns, temporal changes, and clinical course of biloma were studied at the thermal ablation zone after RFA. RESULTS A total of 109 bilomas (3.3%, 109/3,284) developed after RFA in 104 patients in our series. The bilomas developed from 0 to 526 days (mean, 64 days) after RFA, and the mean follow-up period was 469 days (range, 0-2,703 days). The most common morphologic type of biloma was a crescent shape (42.2%). The mean size of the bilomas at initial presentation was 3.8 cm (range, 1.7-11 cm), and the mean size of the bilomas on the last follow-up CT scan was 2.8 cm (range, 0-6.3 cm). Fifty-three (48.6%) of the 109 bilomas resolved during follow-up at a mean interval of 286 days. In one patient, the biloma was considered a major complication because percutaneous drainage was required to manage the biloma with infection (0.9%, 1/109). No patient died of a biloma. CONCLUSION The development of a biloma after percutaneous RFA in patients with HCC was not rare. However, in most cases they were a minor complication of no clinical significance.

Prospective comparison of collagen plug (Angio-Seal) and suture-mediated (the Closer S) closure devices at femoral access sites.

Objective Rapid and effective hemostasis at femoral puncture sites minimizes both the hospital stay and patient discomfort. Therefore, a variety of arterial closure devices have been developed to facilitate the closure of femoral arteriotomy. The objective of this prospective study was to compare the efficacy of two different closure devices; a collagen plug device (Angio-Seal) and a suture-mediated closure device (the Closer S). Materials and Methods From March 28, 2003 to August 31, 2004, we conducted a prospective study in which 1,676 cases of 1,180 patients were treated with two different types of closure device. Angio-Seal was used in 961 cases and the Closer S in 715 cases. The efficacy of the closure devices was assessed, as well as complications occurring at the puncture sites. Results Successful immediate hemostasis was achieved in 95.2% of the cases treated with Angio-Seal, and in 89.5% of the cases treated with the Closer S (p < 0.05). The rates of minor and major complications occurring between the two groups were not significantly different. In the Closer S group, we observed four major complications (0.6%), that consisted of one massive retroperitoneal hemorrhage (surgically explored) and three pseudoaneurysms. In the Angio-Seal group, we observed three major complications (0.3%) that consisted of one femoral artery occlusion, one case of infection treated with intravenous antibiotics and one pseudoaneurysm. Conclusion The use of Angio-Seal was found to be more effective than that of the Closer S with regard to the immediate hemostasis of the femoral puncture sites. However, we detected no significant differences in the rate at which complications occurred.

Growth rate of new hepatocellular carcinoma after percutaneous radiofrequency ablation: evaluation with multiphase CT.

OBJECTIVE The purpose of this study was to evaluate with serial follow-up CT examinations the growth rate of new hepatocellular carcinoma (HCC) developing after percutaneous radiofrequency ablation and to determine an appropriate follow-up interval for imaging. MATERIALS AND METHODS Sixty-two new HCCs appearing after percutaneous radiofrequency ablation in 59 patients who underwent follow-up multiphase CT were retrospectively identified. The volume of the new HCCs at follow-up CT was measured on a PACS monitor with an area measuring tool and summation-of-areas technique. We calculated tumor volume doubling time and tumor diameter doubling time. The growth rate was represented by tumor volume doubling time. We also used stepwise multiple linear regression analysis to evaluate the relation between clinical variables and tumor volume doubling time. RESULTS Mean baseline and follow-up tumor volumes were 580 mm(3) (range, 85-13,861 mm(3)) and 2,072 mm(3) (range, 535-35,937 mm(3)). Mean baseline and follow-up tumor diameters were 9.9 mm (range, 5.5-29.8 mm) and 15.0 mm (range, 10.1-40.9 mm). Mean tumor volume and tumor diameter doubling times were 75 days (range, 21-209 days) and 219 days (range, 57-897 days). Volume doubling times of baseline tumors with a diameter of 1 cm or less were significantly shorter than those of the larger baseline tumors (mean, 55 vs 88 days; p = 0.024). CONCLUSION The growth rate of new HCCs after percutaneous radiofrequency ablation was higher than that reported in natural outcome studies of untreated HCCs. The results of our study suggest that a shorter follow-up interval for imaging, 2.5 months (75 days), is appropriate.

Percutaneous Radiofrequency Ablation for Hepatic Tumors Abutting the Diaphragm: Clinical Assessment of the Heat-Sink Effect of Artificial Ascites

OBJECTIVE This study was designed to assess whether artificial ascites has a heat-sink effect on the ablation zone for percutaneous radiofrequency ablation (RFA) of hepatic tumors abutting the diaphragm. MATERIALS AND METHODS We retrospectively assessed 28 patients who underwent percutaneous RFA for the treatment of a single nodular hepatic tumor that abutted the diaphragm from July 2000 to December 2006. All patients underwent ultrasound-guided RFA using internally cooled electrodes. A single ablation for 12 minutes was applied using 3-cm active-tip electrodes. We divided patients into two groups on the basis of whether artificial ascites was introduced before RFA: Group A consisted of patients who received artificial ascites with a mean of 760 mL of a 5% dextrose in water solution (n = 15) and group B consisted of patients who did not receive artificial ascites (n = 13). The volume of the ablation zone was measured on CT images obtained immediately after the ablation procedure, and imaging findings were compared for both groups using the Students t test. We also compared the local tumor progression rate between both groups using the chi-square test (mean follow-up, 37.4 months). RESULTS There was no significant difference between the two patient groups with regard to age, sex, Child-Pugh class, or tumor location (p > 0.05). The tumors were significantly smaller in group A patients (mean +/- SD, 1.6 +/- 0.5 cm) than in group B patients (2.1 +/- 0.7 cm) (p = 0.019). The mean volume of the RFA zone was 31.6 +/- 11.9 cm(3) in group A patients and 30.9 +/- 11.0 cm(3) in group B patients. There was no significant difference between the groups in the ablation volume (p = 0.871). Local tumor progression was noted in four patients (26.7%) in group A and in three patients (23.1%) in group B. There was no significant difference in the local tumor progression rate between the two groups (p = 0.83). CONCLUSION Artificial ascites did not show a heat-sink effect on the volume of the ablation zone after percutaneous RFA for the treatment of a hepatic tumor abutting the diaphragm.

Detection of early gastric cancer using hydro-stomach CT: blinded vs unblinded analysis.

AIM To evaluate the difference in diagnostic performance of hydro-stomach computed tomography (CT) to detect early gastric cancer (EGC) between blinded and unblinded analysis and to assess independent factors affecting visibility of cancer foci. METHODS Two radiologists initially blinded and then unblinded to gastroscopic and surgical-histological findings independently reviewed hydro-stomach CT images of 110 patients with single EGC. They graded the visibility of cancer foci for each of three gastric segments (upper, middle and lower thirds) using a 4-point scale (1: definitely absent, 2: probably absent, 3: probably present, and 4: definitely present). The sensitivity and specificity for detecting an EGC were calculated. Intraobserver and interobserver agreements were analyzed. The visibility of an EGC was evaluated with regard to tumor size, invasion depth, gastric segments, histological type and gross morphology using univariate and multivariate analysis. RESULTS The respective sensitivities and specificities [reviewer 1: blinded, 20% (22/110) and 98% (215/220); unblinded, 27% (30/110) and 100% (219/220)/reviewer 2: blinded, 19% (21/110) and 98% (216/220); unblinded, 25% (27/110) and 98% (215/220)] were not significantly different. Although intraobserver agreements were good (weighted κ = 0.677 and 0.666), interobserver agreements were fair (blinded, 0.371) or moderate (unblinded, 0.558). For both univariate and multivariate analyses, the tumor size and invasion depth were statistically significant factors affecting visibility. CONCLUSION The diagnostic performance of hydro-stomach CT to detect an EGC was not significantly different between blinded and unblinded analysis. The tumor size and invasion depth were independent factors for visibility.

Central lower attenuating lesion in the ablation zone on immediate follow-up CT after percutaneous radiofrequency ablation for hepatocellular carcinoma: Incidence and clinical significance

PURPOSE The purpose of this study was to evaluate the incidence of central lower attenuating (CLA) lesion in the ablation zone seen on immediate follow-up CT images after percutaneous radiofrequency ablation (RFA) for hepatocellular carcinoma (HCC), and the correlation of CLA lesions and local tumor progression (LTP). SUBJECTS AND METHODS The study group included 146 patients with 167 ablation zones that had undergone follow-up CT examinations for more than 12 months after percutaneous RFA. CLA lesions corresponding to index tumors and ablative margins (safety margins) were evaluated in the ablation zones seen on immediate follow-up CT including coronal and sagittal multiplanar reformatted (MPR) images with narrow window width settings. RESULTS CLA lesions were depicted on 48 of 167 ablation zones (28.7%) on immediate follow-up CT images. Among the 48 ablation zones with CLA lesions, 27 (56.3%, 27/48) had ablative margins on all three of the orthogonal MPR images and they showed no LTP (0%) on follow-up CT examinations. Three of the ablation zones with CLA lesions (6.3%, 3/48) having an ablative margin on one plane only also showed no LTP (0%). LTP was observed in 2 of 18 ablation zones (11.1%) that had CLA lesions without ablative margins on all three planes. In the remaining 119 ablation zones without CLA lesions, 5 (4.2%, 5/119) showed LTP. CONCLUSION CLA lesions in ablation zones were occasionally (28.7%) seen on immediate follow-up CT images after RFA for HCCs. The presence of CLA lesions with ablative margins might be a negative predictor of LTP.

Pneumatosis intestinalis after adult liver transplantation.

Pneumatosis intestinalis is an uncommon disorder characterized by an accumulation of gas in the bowel wall. We described three cases undertaking liver transplantation. The patients developed diarrhea in three cases and high fever in two. An abdominal X-ray and computed tomography scan demonstrated extensive pneumatosis intestinalis in the colon with pneumoperitoneum mimicking hollow organ perforation. However, the patients had no abdominal symptoms and there was no evidence of peritonitis. The infection work-up was negative except one case with cytomegalovirus antigenemia. After one week of conservative management including bowel rest and antibiotic therapy, their pneumoperitoneum resolved spontaneously without any complication. Pneumatosis intestinalis should be considered as a differential diagnosis after adult liver transplantation with patients suffering from watery diarrhea and fever. Pneumoperitoneum, air-density in mesentery and retroperitoneum in patients with pneumatosis intestinalis without signs of peritonitis improved with conservative management, which included bowel rest and antibiotic therapy.

Living Donor Liver Transplantation in a Patient With Extensive Portomesenteric Venous Thrombosis: Case Report

Extensive portomesenteric venous thrombus preventing restoration of adequate portal venous flow used to be considered a contraindication to liver transplantation. The subject was a 49-year-old male with hepatitis B cirrhosis and extensive thrombosis of portal, splenic, and superior mesenteric veins, and two large collateral vessels; one dilated and tortuous inferior to the pancreaticoduodenal vein and relevant to splanchnic venous return and the other a dilated coronary vein relevant to splenic venous return. During operation, the portal vein was anastomosed to these large collateral vessels using cryopreserved iliac vein. In conclusion, portal reconstruction with large collateral vessels in living-donor liver transplantation could be used selectively for patients with extensive portomesenteric venous thrombosis.