Lateral spread response monitoring during microvascular decompression for hemifacial spasm. Comparison of two targets of partial neuromuscular blockade.

AIM: The aim of the present study was to determine (1) whether successful intraoperative electromyography monitoring for lateral spread response (LSR) is possible with partial neuromuscular blockade (NMB) in subjects undergoing microvascular decompression (MVD) for hemifacial spasm and (2) the adequate level of NMB to achieve that goal. MATERIAL AND METHODS: A total of 61 patients in whom LSR was monitored during MVD were enrolled in the study. Patients were randomly allocated to two groups: group TOF in which the NMB target was maintenance of two train-of-four (TOF) counts and group T1 in which the NMB target was maintenance of a T1/Tc ratio of 50 % (T1: first twitch height of TOF and Tc: control twitch height). The adductor pollicis brevis muscle was used to monitor TOF responses. The frequency of successful LSR monitoring, defined as successful baseline establishment and maintenance of LSR until surgical decompression, was compared between the two groups. RESULTS: Of the 61 patients 2 were excluded from the study so that 30 patients in group TOF and 29 patients in group T1 were analyzed. The success rate of LSR monitoring was clinically acceptable and significantly higher in group T1 than in group TOF, i.e. n = 15 (50.0 %) in group TOF versus n = 24 (82.8 %) in group T1 (P = 0.008), corresponding to a 32.8 % higher success rate in group T1 than group TOF (95 % CI: 13.9-51.7 %). Mean vecuronium infusion dose was smaller and mean TOF count was higher in group T1 than group TOF with a TOF count = 2 (1) in group TOF versus 3 (1) in group T1 (P = 0.003). Mean sevoflurane and remifentanil infusion doses were not different between groups. There was no incidence of spontaneous movement during microscopy in either group. CONCLUSION: Maintenance of partial NMB with a target T1/Tc ratio of 50 % resulted in a clinically acceptable success rate of LSR monitoring and surgical condition during MVD. Maintenance of partial NMB with a target T1/Tc ratio of 50 % rather than TOF count of two during LSR monitoring for MVD can therefore be recommended.

Outcomes of endoscopic transpapillary gallbladder stenting for symptomatic gallbladder diseases: a multicenter prospective follow-up study.

BACKGROUND AND STUDY AIMS: Endoscopic transpapillary gallbladder drainage for symptomatic gallbladder disease is a safe and effective bridge therapy in patients at high risk for surgery or who have terminal liver disease and are awaiting transplantation. However, there are few reports on long-term results in terms of stent patency and clinical course. Our study was designed to investigate the long-term patency and clinical course after endoscopic transpapillary gallbladder stenting (ETGS) in patients with symptomatic gallbladder disease. PATIENTS AND METHODS: A total of 29 patients who were unsuitable for cholecystectomy underwent ETGS from June 2006 to March 2010 using a 7-Fr double-pigtail stent between the gallbladder and the duodenum. Their clinical progress, adverse events, and stent patency after ETGS were recorded prospectively in two tertiary referral centers. RESULTS: Technically, ETGS was successful in 23 (79.3%) of the 29 patients. The mean procedure time was 22.4 ± 11.5 min. Postprocedure adverse events were mild pancreatitis (8.7%) and cholestasis (8.7%), all of which resolved with conservative management. During the follow-up period (median 586 days, range 11-1403 days), 20 patients were analyzed as per protocol, and scheduled follow-up was performed. Late adverse events developed in four patients (20%), including distal migration (n = 2), cholangitis (n = 1), and recurrent biliary pain (n = 1). The remaining 16 patients were followed for more than 12 months (nine patients were followed for more than 24 months). Median stent patency was 760 days, as determined by the Kaplan-Meier method. CONCLUSIONS: As a primary therapy, ETGS is technically feasible and effective in patients who are unsuitable for cholecystectomy. ETGS may also provide long-term stent patency without the need for scheduled stent exchanges.

Endoscopic ultrasound-guided versus conventional transmural drainage for pancreatic pseudocysts: a prospective randomized trial.

BACKGROUND AND STUDY AIMS: Although endoscopic ultrasound (EUS)-guided transmural drainage (EUD) is preferred over conventional transmural drainage (CTD) of pancreatic pseudocysts by endoscopy in many centers, its superiority with respect to technical success and clinical outcome has not yet been demonstrated in a prospective randomized trial. We conducted this prospective randomized trial to compare the technical success and clinical outcomes of EUD and CTD in treating pancreatic pseudocysts. PATIENTS AND METHODS: A total of 60 consecutive patients with pancreatic pseudocysts were randomly divided into two groups to undergo either EUD (n = 31) or CTD (n = 29) of pancreatic pseudocysts. The technical success rate, complications, and short-term and long-term results were prospectively evaluated. RESULTS: The rate of technical success of the drainage was higher for EUD (94 %, 29/31) than for CTD (72 %, 21/29; P = 0.039) in intention-to-treat analysis. In cases where CTD failed (n = 8), because the pseudocysts were nonbulging, a crossover was made to EUD, which was successfully performed in all these patients. Complications occurred in 7 % of the EUD and 10 % of the CTD group ( P = 0.67). During short-term follow-up, pseudocyst resolution was achieved in 97 % (28/29) in the EUD group and in 91 % (19/21) in the CTD group ( P = 0.565). Long-term results analyzed on a per-protocol basis showed no significant difference in clinical outcomes between EUD (89 %, 33/37) and CTD (86 %, 18/21, P = 0.696). CONCLUSIONS: We found that EUD and CTD can both be considered first-line methods of endoscopic transmural drainage of bulging pseudocysts, whereas EUD should be preferred for nonbulging pseudocysts.

A randomised phase II study of modified FOLFIRI.3 vs modified FOLFOX as second-line therapy in patients with gemcitabine-refractory advanced pancreatic cancer.

BACKGROUND: Only a few clinical trials have been conducted in patients with advanced pancreatic cancer after failure of first-line gemcitabine-based chemotherapy. Therefore, there is no current consensus on the treatment of these patients. We conducted a randomised phase II study of the modified FOLFIRI.3 (mFOLFIRI.3; a regimen combining 5-fluorouracil (5-FU), folinic acid, and irinotecan) and modified FOLFOX (mFOLFOX; a regimen combining folinic acid, 5-FU, and oxaliplatin) regimens as second-line treatments in patients with gemcitabine-refractory pancreatic cancer. METHODS: The primary end point was the 6-month overall survival rate. The mFOlFIRI.3 regimen consisted of irinotecan (70 mg m(-2); days 1 and 3), leucovorin (400 mg m(-2); day 1), and 5-FU (2000 mg m(-2); days 1 and 2) every 2 weeks. The mFOLFOX regimen was composed of oxaliplatin (85 mg m(-2); day 1), leucovorin (400 mg m(-2); day 1), and 5-FU (2000 mg m(-2); days 1 and 2) every 2 weeks. RESULTS: Sixty-one patients were randomised to mFOLFIRI.3 (n=31) or mFOLFOX (n=30) regimen. The six-month survival rates were 27% (95% confidence interval (CI)=13-46%) and 30% (95% CI=15-49%), respectively. The median overall survival periods were 16.6 and 14.9 weeks, respectively. Disease control was achieved in 23% (95% CI=10-42%) and 17% patients (95% CI=6-35%), respectively. The number of patients with at least one grade 3/4 toxicity was identical (11 patients, 38%) in both groups: neutropenia (7 patients under mFOLFIRI.3 regimen vs 6 patients under mFOLFOX regimen), asthaenia (1 vs 4), vomiting (3 in both), diarrhoea (2 vs 0), and mucositis (1 vs 2). CONCLUSION: Both mFOLFIRI.3 and mFOLFOX regimens were tolerated with manageable toxicity, offering modest activities as second-line treatments for patients with advanced pancreatic cancer, previously treated with gemcitabine.

Is a 2-week steroid trial after initial negative investigation for malignancy useful in differentiating autoimmune pancreatitis from pancreatic cancer? A prospective outcome study.

BACKGROUND: Autoimmune pancreatitis (AIP) is a peculiar type of chronic pancreatitis that responds dramatically to steroid therapy. To date, there are no worldwide consensus criteria for AIP. Different criteria with institutional preference (HISORt, revised Kim and the revised Japanese criteria) are being used to diagnose AIP, and there is controversy regarding the inclusion of steroid responsiveness in the diagnostic criteria. In contrast to the HISORt and revised Kim criteria, the revised Japanese criteria do not include steroid responsiveness as a diagnostic component. AIMS: This study was performed to evaluate whether "a 2-week steroid trial and subsequent assessment of its response" is a useful diagnostic tool for the differentiation of AIP from pancreatic cancer. A further aim was to discover the surgical and clinical outcome for a patient who followed the treatment algorithm based on the steroid responsiveness. PATIENTS AND METHODS: From January 2004 to June 2007, in the setting of clinically suspected AIP, 22 consecutive patients with atypical imaging for AIP, while not meeting the classic imaging criteria for pancreatic cancer, were challenged to undergo 2 weeks of steroid therapy (0.5 mg/kg of oral prednisolone per day). After the 2-week steroid trial, steroid responsiveness was assessed based on a marked improvement of narrowing of the main pancreatic duct and a reduction of the pancreatic mass. The steroid trial was continued in the case of positive steroid responsiveness, whereas surgical exploration was conducted in the case of negative steroid responsiveness. The final diagnosis was made by surgical exploration or long-term clinical and radiological follow-up. RESULTS: All patients (n = 15) who responded to steroids were diagnosed as having AIP, whereas all patients (n = 7) who did not show a response to steroids were confirmed as having pancreatic cancer. Complete resection was possible in all (6/6; 100%), except one individual who refused surgery. CONCLUSION: In the clinical setting of suspected AIP with the continued need for differentiation from pancreatic cancer due to atypical imaging for AIP, "a 2-week steroid trial and subsequent assessment of its response" may be helpful in confirming the diagnosis of AIP without negative consequences for resectable pancreatic cancer. However, a steroid trial should be performed carefully only by specialists in pancreatology.

Histone deacetylase inhibitor apicidin downregulates DNA methyltransferase 1 expression and induces repressive histone modifications via recruitment of corepressor complex to promoter region in human cervix cancer cells.

Dysregulation of DNA methyltransferase (DNMT)1 expression is associated with cellular transformation, and inhibition of DNMT1 exerts antitumorigenic effects. Here, we report that DNMT1 abnormally expressed in HeLa cells is downregulated by a histone deacetylase (HDAC) inhibitor apicidin, which is correlated with induction of repressive histone modifications on the promoter site. Apicidin selectively represses the expression of DNMT1 among DNMTs in HeLa cells, independent of cell cycle arrest at G0/G1. Furthermore, apicidin causes a significant reduction in the recruitment of RNA polymerase II into the promoter. Chromatin immunoprecipitation analysis shows that even though apicidin causes global hyperacetylation of histone H3 and H4, localized deacetylation of histone H3 and H4 occurs at the E2F binding site, which is accompanied by the recruitment of pRB and the replacement of P/CAF with HDAC1 into the sites. In addition, K4-trimethylated H3 on nucleosomes associated with the transcriptional start site is depleted following apicidin treatment, whereas repressive markers, K9- and K27-trimethylation of H3 are enriched on the site. The downregulation of DNMT1 expression seems to require de novo protein synthesis, because the apicidin effect is antagonized by cycloheximide treatment. Moreover, knock down of DNMT1 with siRNA induces the apoptosis of HeLa cells, indicating that downregulation of DNMT1 might be a good strategy for therapeutics of human cervix cancer. Collectively, our findings will provide a mechanistic rationale for the use of HDAC inhibitors in cancer therapeutics.

Analysis of percutaneous transhepatic cholangioscopy-related complications and the risk factors for those complications.

BACKGROUND AND STUDY AIMS: Percutaneous transhepatic cholangioscopy (PTC) is being increasingly used for patients with biliary tract diseases. The aim of this study was to assess the safety of this procedure, and we systematically analyzed PTC-related complications and the risk factors for those complications. PATIENTS AND METHODS: A total of 364 patients who underwent PTC were included in the study. The initial diagnoses, the indications for PTC, the complications that occurred during the procedures, and the risk factors for these complications were retrospectively analyzed. RESULTS: The overall incidence of complications was 12.9 % for percutaneous transhepatic biliary drainage (PTBD), 12.8 % for tract dilation, and 6.9 % for tract maturation. Complications developed in 58/848 PTC sessions (6.9 %). Cholangitis and bacteremia were associated with PTBD and tract dilation, catheter migration and blockage with tract maturation, and bile duct injury with PTC. Mild complications occurred in 80 patients (22.2 %) during the preparation stages and in 43 sessions (5.1 %) during the PTC itself. Severe complications, including severe hemobilia, hemoperitoneum, rupture of the sinus tract, and ductal injury developed in 17 patients (4.7 %) during the preparation period, and in 15 patients (4.1 %) during PTC. The overall incidence of severe complications along the entire course was 8.2 % (30/364 patients). No patient died or required surgery. Intraductal manipulations, such as electrohydraulic lithotripsy or balloon dilation, and the first session of PTC were risk factors for procedure-related complications. CONCLUSIONS: PTC is a relatively safe and well-tolerated method for treating certain biliary tract diseases. Meticulous patient selection and a cooperative team approach are required in order to minimize the incidence of complications and to provide effective management.

Endoscopic removal of biliary self-expandable metallic stents: a prospective study.

BACKGROUND AND STUDY AIMS: The transpapillary endoscopic insertion of self-expandable metallic stents (SEMSs) has been widely used for the palliation of unresectable malignant biliary obstruction. We attempted the endoscopic removal of malfunctioning SEMSs. The aim of this study was to assess the feasibility and safety of the endoscopic removal of SEMSs by comparing the results between removal of covered and uncovered SEMSs. PATIENTS AND METHODS: 30 patients with a malfunctioning biliary SEMS prospectively underwent an attempt at endoscopic removal of the biliary SEMS over a 2-year period. Removal of the malfunctioning SEMS was done with a therapeutic duodenoscope (ED-450XT5 or TJF-240), using a rat-tooth forceps. Of the 30 SEMS used, 22 were silicone-covered Wallstents, while eight were uncovered SEMSs including five uncovered Wallstents and three Zilver stents. The time for an attempt at each endoscopic removal was limited to 15 minutes in a single endoscopic procedure session. RESULTS: The covered SEMSs were easily removed in 19 out of 22 patients (86.4 %), whereas none of the eight uncovered SEMSs (0 %) could be removed. The only factor predicting successful stent removal was the presence of a stent covering ( P = 0.000). There was no morbidity or mortality related to endoscopic removal of malfunctioning stents. CONCLUSIONS: In contrast to uncovered biliary SEMSs, in most cases malfunctioning covered biliary SEMSs can be easily and safely removed endoscopically using a rat-tooth forceps.

Clinicopathological review of 61 patients with early bile duct cancer.

AIMS: The concept of early cancer is already established in the hollow viscus. However, there is no broadly accepted concept of early bile duct cancer. We aimed to assess whether early bile duct cancer patients have characteristic clinicopathological features and a better prognosis compared with patients with advanced bile duct cancer. MATERIALS AND METHODS: Between June 1996 and December 2004, 614 patients were histologically confirmed with primary bile duct cancers after resection. Extrahepatic early bile duct cancers are defined as carcinoma where invasion is confined within the fibromuscular layer of the extrahepatic bile duct. Intrahepatic early bile duct cancers arising from intrahepatic large bile ducts are also defined as carcinoma confined within the fibromuscular layer. We retrospectively reviewed medical records to obtain demographic, laboratory, radiological and pathological data. RESULTS: Sixty-one (10%) patients were categorised with early bile duct cancers. They were frequently detected at asymptomatic (39%) or non-icteric (84%) stages. The most common gross type was the intraductal-growing type (58%). Not otherwise specified adenocarcinoma was only 67%, whereas papillary carcinoma was 31% of cancers. No lymph node metastasis and no lymphovascular/perineural invasions were noted in 89% of patients. The 5-year survival rate for early bile duct cancer was excellent (80%). CONCLUSIONS: Although early bile duct cancer is not a common disease, it is not a very rare entity either. The clinicopathological features of early bile duct cancer patients differ from those of advanced bile duct cancer patients, with asymptomatic clinical presentation, different macroscopic and microscopic findings, and excellent prognosis.

Hypoxia in presence of blockers of excitotoxicity induces a caspase-dependent neuronal necrosis.

When excitotoxic mechanisms are blocked, severe or prolonged hypoxia and hypoxia-ischemia can still kill neurons, by a mechanism which is poorly understood. We studied this "non-excitotoxic hypoxic death" in primary cultures of rat dentate gyrus neurons. Many neurons subjected to hypoxia in the presence of blockers of ionotropic glutamate receptors developed the electron microscopic features of necrosis. They showed early mitochondrial swelling, loss of mitochondrial membrane potential and cytoplasmic release of cytochrome c, followed by activation of caspase-9, and by caspase-9-dependent activation of caspase-3. Caspase inhibitors were neuroprotective. These results suggest that "non-excitotoxic hypoxic neuronal death" requires the activation in many neurons of a cell death program originating in mitochondria and leading to necrosis.

Activation of NF-kappaB by HDAC inhibitor apicidin through Sp1-dependent de novo protein synthesis: its implication for resistance to apoptosis.

Histone deacetylase (HDAC) inhibitors are promising anti-cancer drugs, but these exert differential responses depending on the cell types. Here, we demonstrate a new mechanism for activation of nuclear factor-kappaB (NF-kappaB) by HDAC inhibitor apicidin and the role of NF-kappaB signaling pathway for mediating differential cellular responses, especially, apoptosis. Treatment of HeLa cells with apicidin increases transcriptional activity of NF-kappaB and its target gene IL-8 and cIAP-1 induction, which involves the activation of IKK-IkappaBalpha signaling pathway through Sp1-dependent de novo protein synthesis. In parallel, apicidin treatment leads to histone hyperacetylation in the IL-8 promoter region independent of NF-kappaB signaling pathway, which is not sufficient for full transcription of IL-8 gene. This NF-kappaB activation contributes to resistance of HeLa cells to apoptotic potential of apicidin. Collectively, our results suggest that activation of NF-kappaB signaling cascade functions as a critical modulator to determine cell fate on apoptosis in response to HDAC inhibitors.

Surgical resection of cavernous angiomas located in eloquent areas--clinical research.

BACKGROUND: In patients with lesions at the eloquent areas, the aim of surgical interventions should be a more radical removal of the lesions with preservation of brain function. In this retrospective study, our techniques for localizing lesion and the postoperative results of 26 patients with cavernous angiomas (CA) located at the eloquent areas are summarized. METHOD: The MR based 3D-rendering images were reconstructed from the 2D MR images by using a computerized program. These images were obtained in all patients for the localization of their lesion. Following craniotomy, to verify the actual location of lesions, we compared the 3D-image to the exposed cortical surface. Simultaneously, intraoperative ultrasonogram (IOUS) was used for the accurate localization of the lesion. In order to minimize the damage to the eloquent area, the minimal corticotomy was planned at the margin of the sulcus nearest to the lesion. FINDINGS: An accurate localization of the lesion was possible in all 26 patients and the eloquent areas near the lesions were identified on the operation field. Complete removal of the CAs was done in all cases. One patient developed temporary monoparesis postoperatively, but the patient fully recovered in a month. Fourteen patients presented with preoperative seizures, and all patients had excellent seizure outcome after their surgery. The mean duration of the follow-up period was 27 months. CONCLUSIONS: We could localize the lesion accurately using MRI 3D-rendering images and IOUS during the operation for CA. We planned minimal corticotomy to the lesion and we completely removed the lesion without causing any additional neurological deficit. Although CA can be located in eloquent areas, surgical removal of these lesions is a safe and effective treatment option for lowering the risk of developing symptoms and controlling the seizure.

Accuracy of magnetic resonance cholangiopancreatography for locating hepatolithiasis and detecting accompanying biliary strictures.

BACKGROUND AND STUDY AIMS: Magnetic resonance cholangiopancreatography (MRCP) is rapidly replacing diagnostic endoscopic retrograde cholangiopancreatography (ERCP) in various pancreaticobiliary diseases. This study was designed to evaluate the accuracy of MRCP in detection of hepatolithiasis and accompanying biliary strictures. PATIENTS AND METHODS: A prospective study over 2 years was conducted in 66 patients with primary intrahepatic stones. All patients with hepatolithiasis underwent percutaneous transhepatic cholangioscopy (PTC) within 2 weeks of the MRCP examination. The MRCP findings were compared with those of PTC as the reference standard for assessing the location of intrahepatic stones and the presence or absence of accompanying biliary strictures. RESULTS: The sensitivity, specificity, and accuracy of MRCP for detecting and locating intrahepatic stones were 97 %, 99 %, and 98 %, respectively. The sensitivity, specificity, and accuracy of MRCP for detecting and locating intrahepatic bile duct strictures were 93 %, 97 %, and 97 %, respectively. During PTC, six of the 66 patients (9 %) were found on histology to have intraductal cholangiocarcinoma in stone-bearing ducts, which had not been suspected on MRCP. CONCLUSIONS: In this study, MRCP allowed intrahepatic stones and accompanying biliary strictures to be located accurately. MRCP may therefore be able to replace diagnostic ERCP in patients with primary intrahepatic stones. However, MRCP had a limited ability to reveal concurrent intraductal cholangiocarcinoma associated with hepatolithiasis.

Effect of hypothermia on bilirubin-induced alterations in brain cell membrane function and energy metabolism in newborn piglets.

The aim of this study was to evaluate the effects of hypothermia on bilirubin-induced alterations in brain cell membrane function and energy metabolism in the developing brain. Thirty-seven newborn piglets were divided randomly into four groups: normothermic control (NC, n=9); hypothermic control (HC, n=7); normothermic bilirubin infusion (NB, n=11); and hypothermic bilirubin infusion (HB, n=10) groups. In bilirubin infusion groups (NB and HB), a loading dose of bilirubin (35 mg/kg) was given over 5 min, followed by a continuous infusion (25 mg/kg/h) for 4 h. The control groups (NC, HC) received a bilirubin-free buffer solution. Sulfadimethoxine was administered to animals in all experimental groups. Rectal temperature was maintained between 38.0 and 39.0 degrees C in normothermic groups, and between 34.0 and 35.0 degrees C in hypothermic groups for 4 h after the start of bilirubin infusion. The final blood and brain bilirubin concentrations in the bilirubin infusion groups (NB and HB) were not significantly different. Decreased cerebral cortical cell membrane Na(+),K(+)-ATPase activity and increased lipid peroxidation products observed in the NB group, indicative of bilirubin-induced brain damage, were significantly attenuated in the HB group. Hypothermia also significantly improved the bilirubin-induced reduction in brain ATP and phosphocreatine levels and increase in blood and brain lactate levels. In summary, hypothermia significantly attenuated the bilirubin-induced alterations in brain cell membrane function and energy metabolism in the newborn piglet. These findings suggest the possibility that hypothermia could be a good neuroprotective therapeutic modality in neonatal bilirubin encephalopathy.

Percutaneous transhepatic cholangioscopic treatment for hepatolithiasis: an evaluation of long-term results and risk factors for recurrence.

BACKGROUND: Percutaneous transhepatic cholangioscopy (PTCS) has a major role in the treatment of hepatolithiasis. The aims of this study were to evaluate immediate and long-term results of PTCS treatment and to elucidate the risk factors for recurrence of stones or cholangitis. METHODS: A retrospective study was conducted of patients with hepatolithiasis who underwent PTCS treatment. A total of 92 patients underwent PTCS treatment and 68 were followed for 24 to 60 months (median 42 months). RESULTS: Complete clearance of stones was achieved in 74 (80%) patients. The rate of complete clearance was significantly lower in patients with severe intrahepatic strictures compared with that for those with no strictures (14 of 24, 58% vs. 16 of 16, 100%, p < 0.01) and those with mild to moderate strictures (14 of 24, 58% vs. 44 of 52, 85%, p < 0.05). Patients with severe intrahepatic strictures had a higher recurrence rate than those with no or mild strictures (100% vs. 28%, p < 0.01). In addition the recurrence rate in patients with advanced biliary cirrhosis (Child's class B or C) was higher than in those with no or mild (Child's class A) cirrhosis (89% vs. 29%, p < 0.01). In patients with type I and II hepatolithiasis (Tsunoda classification), stones recurred in 2 (12%) patients at 28 and 32 months after successful stone removal, without further recurrence afterwards. The recurrence rate in patients with type III and IV hepatolithiasis increased gradually up to 50% at 60 months of follow-up. CONCLUSIONS: Severe intrahepatic stricture was the only factor that affected the immediate success rate of PTCS in the treatment of hepatolithiasis. Several risk factors including severe biliary stricture, advanced biliary cirrhosis and Tsunoda type III and IV affected the long-term results.

Characterization of primary pure cholesterol hepatolithiasis: cholangioscopic and selective cholangiographic findings.

BACKGROUND: Primary pure cholesterol hepatolithiasis has been described recently. The aim of this study was to analyze its clinical and radiologic features, focusing on the cholangioscopic and selective cholangiographic findings. METHODS: Primary pure cholesterol hepatolithiasis was identified in 3% (6 of 172) of patients who were treated with cholangioscopic stone removal for primary hepatolithiasis during the study period from 1995 to 1999. These 6 consecutive patients (M/F 5:1, mean age 40 years) were enrolled in the study. They underwent abdominal US, CT, endoscopic retrograde cholangiography (ERC), and percutaneous transhepatic cholangioscopy (PTCS). After confirming that the stones were of the cholesterol type, cholangioscopic stone removal via the percutaneous transhepatic route was performed. For the prevention of recurrence, ursodeoxycholic acid (10 mg/kg/day) was prescribed during follow-up. RESULTS: US demonstrated high echogenicity with strong shadowing in dilated peripheral ducts, whereas CT failed to demonstrate any intraductal abnormal density or calcification except localized duct dilatation. PTCS demonstrated multiple, white to yellowish stones that were morphologically readily distinguishable from brown pigment intrahepatic stones. In all patients, selective cholangiography disclosed the ductal abnormalities, which could not be delineated by ERC in 4 patients. Complete stone removal by PTCS was achieved in 5 of 6 patients. During follow-up (12 to 49 months, mean 22 months), they were asymptomatic and stone recurrence was not detected by US. CONCLUSIONS: Primary pure cholesterol hepatolithiasis is distinguishable from the more common brown pigment hepatolithiasis by its cholangioscopic and selective cholangiographic characteristics.