Young Ho Choi

Balloon-Occluded Retrograde Transvenous Obliteration for Gastric Variceal Bleeding: Its Feasibility Compared with Transjugular Intrahepatic Portosystemic Shunt

Objective To assess the feasibility of balloon-occluded retrograde transvenous obliteration (BRTO) in active gastric variceal bleeding, and to compare the findings with those of transjugular intrahepatic portosystemic shunt (TIPS). Materials and Methods Twenty-one patients with active gastric variceal bleeding due to liver cirrhosis were referred for radiological intervention. In 15 patients, contrast-enhanced CT scans demonstrated gastrorenal shunt, and the remaining six (Group 1) underwent TIPS. Seven of the 15 with gastrorenal shunt (Group 2) were also treated with TIPS, and the other eight (Group 3) underwent BRTO. All patients were followed up for 6 to 21 (mean, 14.4) months. For statistical inter-group comparison of immediate hemostasis, rebleeding and encephalopathy, Fishers exact test was used. Changes in the Child-Pugh score before and after each procedure in each group were statistically analyzed by means of Wilcoxons signed rank test. Results One patient in Group 1 died of sepsis, acute respiratory distress syndrome, and persistent bleeding three days after TIPS, while the remaining 20 survived the procedure with immediate hemostasis. Hepatic encephalopathy developed in four patients (one in Group 1, three in Group 2, and none in Group 3); one, in Group 2, died while in an hepatic coma 19 months after TIPS. Rebleeding occurred in one patient, also in Group 2. Except for transient fever in two Group-3 patients, no procedure-related complication occurred. In terms of immediate hemostasis, rebleeding and encephalopathy, there were no statistically significant differences between the groups (p > 0.05). In Group 3, the Child-Pugh score showed a significant decrease after the procedure (p = 0.02). Conclusion BRTO can effectively control active gastric variceal bleeding, and because of immediate hemostasis, the absence of rebleeding, and improved liver function, is a good alternative to TIPS in patients in whom such bleeding, accompanied by gastrorenal shunt, occurs.

Sonographic Features of Follicular Variant Papillary Thyroid Carcinomas in Comparison With Conventional Papillary Thyroid Carcinomas

Objective. The purpose of this study was to compare the sonographic features as well as the results of fine‐needle aspiration biopsy (FNAB) of follicular variant papillary thyroid carcinoma (FVPTCs) and conventional papillary thyroid carcinoma (PTCs). Methods. Forty patients with 44 FVPTCs and 59 patients with 74 conventional PTCs were enrolled in this study. The sonographic features, sonographic gradings, and FNAB results were compared between the two groups. Results. The mean nodule size of FVPTCs was larger than that of conventional PTCs (17.70 versus 10.53 mm; P < .001). Sonographic features of an ovoid‐to‐round shape (95% versus 73%), isoechogenicity (52% versus 8%), and a hypoechoic halo (25% versus 3%) were more frequent in FVPTCs than conventional PTCs (P < .001). Sonographic features of a taller‐than‐wide shape (5% versus 22%), a spiculated margin (7% versus 32%), marked hypoechogenicity (5% versus 38%), and microcalcification (7% versus 24%) were rarer in FVPTCs than conventional PTCs (P < .05). The incidence of a sonographically malignant grade was also lower in FVPTCs (48%) than conventional PTCs (81%; P < .001). A diagnosis of PTC on FNAB of FVPTCs was less common than that of conventional PTCs (28% versus 56%; P = .0393); however, a diagnosis of an indeterminate cytologic type such as atypical cells or follicular lesions in FVPTCs was higher than that in conventional PTCs (46% versus 19%; P = .0418). Conclusions. Follicular variant papillary thyroid carcinomas show a relatively larger size, more benign sonographic features, a lower incidence of a sonographically malignant grade, and a lower diagnostic rate of PTC on FNAB compared with conventional PTCs.

Craniofacial cavernous venous malformations: Percutaneous sclerotherapy with use of ethanolamine oleate

PURPOSE To assess the efficacy of percutaneous sclerotherapy with use of ethanolamine oleate for craniofacial cavernous venous malformations. MATERIALS AND METHODS From 1991 to 2001, sclerotherapy (average of two procedures per patient) was performed in 29 patients (mean age, 22 y; 10 male) with craniofacial venous malformations. Direct puncture venography was performed with use of water-soluble contrast media to delineate the extent of the lesions. CO(2) gas was used as contrast medium in addition to water-soluble contrast media in five patients in whom lesions had large nondependent areas. Coil embolization with a transvenous approach was performed in two patients when the lesions had large draining veins. Then, a mixture of 5% ethanolamine oleate and iodized oil (ratio, 5:1-5:2) was injected manually into the lesions under fluoroscopic guidance to monitor the process. A total of 59 procedures were performed. Clinical follow-up was obtained in 25 of 29 patients. The duration of follow-up ranged from 10 days to 6 years (mean, 8.5 mo). The effectiveness of sclerotherapy was assessed on the basis of clinical, surgical, and radiologic findings. RESULTS The procedures were effective in 14 of 16 patients who underwent sclerotherapy only. The procedures were beneficial for all nine patients who underwent sclerotherapy and surgery. There was no skin injury or nerve damage. The trismus that appeared in two patients with lesions in the masticator space was treated well by conservative therapy. CONCLUSION Percutaneous sclerotherapy with use of ethanolamine oleate is a safe and effective treatment of craniofacial cavernous venous malformations. However, renal function was not specifically evaluated after treatment, and therefore occult renal dysfunction cannot be excluded.

Minimally invasive repair of pectus excavatum: A novel morphology-tailored, patient-specific approach

OBJECTIVE Minimally invasive repair of pectus excavatum, introduced by Nuss in 1998, has undergone a serious learning curve because of a lack of understanding on morphologies and repair techniques. To summarize the current status of minimally invasive repair of pectus excavatum, we reviewed and appraised our 10-year experience with a novel approach, a morphology-tailored technique, including diverse bar shaping, bar fixation, and techniques for adults. METHODS We analyzed the data of 1170 consecutive patients with pectus excavatum who underwent minimally invasive repair between August 1999 and September 2008. All pectus repairs were performed by the primary author (H.J.P.) with our modified technique. RESULTS The mean age was 10.3 years (range, 16 months to 51 years). There were 331 adult patients (>15 years) (28.3%). A total of 576 patients (49.2%) had bar removal after a mean of 2.5 years (range, 10 days to 7 years). The asymmetry index change (1.10-1.02, P < .001) demonstrated post-repair symmetry. Complication rates decreased through the 3 time periods (1999-2002 [n = 335]; 2003-2005 [n = 441]; 2006-2008 [n = 394]) as follows: pneumothorax rate (7.5% vs 4.3% vs 0.8%; P < .001) and bar displacement rate (3.8% vs 2.3% vs 0.5%; P = .002). Reoperation rate also decreased (4.8% vs 2.5% vs 0.8%; P = .002). Satisfaction outcomes were excellent in 92.7%, good in 5.9%, and fair in 1.4% of patients. After bar removal, 3 patients (0.6%) had minor recurrences. CONCLUSION Minimally invasive repair of pectus excavatum based on a novel morphology-tailored, patient-specific approach is effective for quality repair of the full spectrum of pectus excavatum, including asymmetry and adult patients. Continuous technical refinements have significantly decreased the complication rates and postoperative morbidity.

Transcatheter Arterial Chemoembolization for Hepatocellular Carcinomas in Patients with Celiac Axis Occlusion

PURPOSE To verify the hypothesis that most instances of celiac axis occlusion in patients with hepatocellular carcinoma (HCC) are caused by diaphragmatic compression and, therefore, transcatheter arterial chemoembolization (TACE) can be performed through the compressed lumen of the celiac axis. MATERIALS AND METHODS The authors attempted to perform TACE in 36 consecutive patients with HCC and celiac axis occlusion. Spiral computed tomographic (CT) images were available in 26 patients. Initially, catheterization of the hepatic arteries was attempted through the occluded celiac axis. If it failed, catheterization was performed through the pancreaticoduodenal arcades. The causes of celiac axis occlusion were evaluated based on spiral CT and angiographic findings, access routes, technical success rates, and related complications in superselective catheterization of hepatic arteries. RESULTS Among the 26 patients who underwent spiral CT, diaphragmatic compression of the celiac axis was demonstrated in 23. Selective catheterization of hepatic arteries was possible through the occluded celiac axis in 23 patients (64%). In nine (25%) of the remaining 13 patients, TACE was performed through the dilated pancreaticoduodenal arcades from the superior mesenteric artery. As a procedure-related complication, celiac axis dissection occurred in one patient (3%). CONCLUSION Most patients with celiac axis occlusion had arcuate ligament compression. In TACE, the celiac artery occlusion could be traversed directly and this should be the initial approach.

Intra-operative sentinel lymph node identification using a novel receptor-binding agent (technetium-99m neomannosyl human serum albumin, 99mTc-MSA) in stage I non-small cell lung cancer

OBJECTIVE In the previous report, to simplify the synthesis and labelling procedures and to improve the biological properties, we developed a novel mannose receptor-binding agent, technetium-99m human serum albumin (99mTc-MSA), for sentinel lymph node detection. This study is the first clinical trial designed to test the reliability and feasibility of sentinel node detection using this new radioactive agent in patients with stage I non-small cell lung cancer. METHODS Forty-two patients (30 men, 12 women; mean age 63.3 + or - 8.9 years) that were candidates for lobectomy with mediastinal lymph node dissection for stage I non-small cell lung cancer were enrolled. A total dose of 1mCi of 99mTc-MSA in 0.2 ml was administered in one shot at the peritumoural region approximately 3h before surgery. The radioactivity in the lymph nodes was counted before (in vivo) and after (ex vivo) dissection with a hand-held gamma probe. A sentinel lymph node was defined as any node for which the radioactivity count was 5 times that of the resected lung tissue with the lowest count for the ex vivo counts. All harvested lymph nodes were cut into 2-mm slices and ultimately diagnosed by using formalin-fixed and paraffin-embedded sections with haematoxylin and eosin staining. RESULTS 99mTc-MSA was taken up by the lymph nodes and its detection did not change until 21 h after the injection. The number of dissected lymph nodes per patient was 22.1 + or - 11.6 (range 4-57). Among 42 patients, the sentinel lymph nodes could be identified in 40 patients (95.2%). The number of sentinel lymph nodes identified was 2.3 + or - 1.1 stations (range 1-5) per patient. Ten out of 40 patients (25.0%) had metastases in 11 sentinel lymph nodes. Three of these 11 sentinel lymph nodes (27.3%) had skip metastases. No false-negative sentinel lymph nodes were detected in any of the 10 patients with N1 or N2 disease (0%). The relationship between in vivo and ex vivo results for mediastinal sentinel lymph nodes showed concurrence in 29 out of 40 patients (72.5%). CONCLUSIONS Intra-operative sentinel lymph node identification using 99mTc-MSA appears to be feasible and reliable in stage I non-small cell lung cancer.

Effects of enzyme inducers and inhibitors on the pharmacokinetics of intravenous ipriflavone in rats.

In order to find out what types of the hepatic microsomal cytochrome P450 (CYP) isozymes are involved in the metabolism of ipriflavone, ipriflavone at a dose of 20 mg kg−1 (or 15 mg kg−1) was infused in male Sprague—Dawley rats. In rats pretreated with SKF 525‐A (a non‐specific CYP isozyme inhibitor in rats), the total body clearance (CL) of ipriflavone was significantly slower (29.9% decrease) than that in control rats. This indicates that ipriflavone is metabolized via CYP isozymes in rats, hence various enzyme inducers and inhibitors were used in in‐vitro or in‐vivo studies in rats. In rats pretreated with 3‐methylcholanthrene and phenobarbital (main inducers of CYP1A1/2 and 2B1/2 in rats, respectively), the CL values were significantly higher (153 and 67.2% increases, respectively). In rats pretreated with sulfaphenazole (a main inhibitor of CYP2C11 in rats), the CL was significantly slower (22.5% decrease) than that in control rats. On addition of furafylline (a main inhibitor of CYP1A2 in rats), the in‐vitro intrinsic clearance for the disappearance of ipriflavone was significantly slower (50.8% decrease) than that without furafylline. However, the CL values were not significantly different in rats pretreated with orphenadrine and isoniazid (a main inducer of CYP2E1 in rats), and quinine and troleandomycin (main inhibitors of CYP2D1 and 3A23/2 in rats, respectively) compared to controls. These data suggest that ipriflavone could be metabolized mainly via CYP1A1/2, 2B1/2 and 2C11 in rats.

Sentinel Node Identification Using Technetium-99m Neomannosyl Human Serum Albumin in Esophageal Cancer

BACKGROUND This study is a clinical trial designed to test the reliability and feasibility of sentinel node detection using a new mannose receptor radioactive binding agent in patients with esophageal squamous cell carcinoma. METHODS Twenty-three patients (21 men, 2 women; mean age 61.0±8.60 years) who were candidates for esophagectomy with conventional lymph node dissection for thoracic esophageal cancer were enrolled. A total dose of 1 mCi of 99mTc-MSA [technetium-99m neomannosyl human serum albumin] in 0.2 mL was administered at 4 quadrants into the submucosal layer around the primary tumor under esophagoscopic guidance approximately 1 hour before surgery. Intraoperative sentinel node sampling was subsequently followed by esophagectomy. All harvested lymph nodes were cut into 2-mm slices and ultimately diagnosed using formalin-fixed and paraffin-embedded sections with hematoxylin and eosin staining. RESULTS The number of dissected lymph nodes per patient was 30.5±9.18 (15-47). Among 23 patients, the sentinel lymph nodes could be identified in 21 patients (91.3%). The sentinel nodes could be identified in all 21 patients with cT1 or T2N0M0 (100%) disease; these patients were candidates for sentinel lymph node navigation surgery for the esophageal cancer. The mean number of sentinel nodes identified was 2.6±1.35 (range, 1-5) per patient. No false-negative sentinel lymph nodes were detected in any of the 8 patients with node-positive disease (0%). CONCLUSIONS Intraoperative sentinel lymph node identification using 99mTc-MSA was feasible and reliable in patients with esophageal squamous cell carcinoma.

Changes in metformin pharmacokinetics after intravenous and oral administration to rats with short‐term and long‐term diabetes induced by streptozotocin

It has been reported that metformin was primarily metabolized via hepatic CYP2C11, 2D1, and 3A1/2 in rats, and the expression and mRNA levels of hepatic CYP2C11 and 3A1 decreased and increased, respectively, whereas the expression of CYP2D1 was not changed in rat model of diabetes induced by streptozotocin (DMIS). Also minimizing the toxic effects of streptozotocin by carrying out experiments 4-5 weeks after streptozotocin injection has been reported. Thus, the pharmacokinetics of metformin was evaluated in rat model of DMIS at the 7th and the 29th days after streptozotocin injection. After intravenous administration of metformin (100 mg/kg) to rat model of DMIS, the CL(R) became significantly faster (46.9% and 77.8% increase for the 7th and the 29th days, respectively; due to urine flow rate-dependent timed-interval renal clearance of the drug) and CL(NR) became significantly slower (28.0% and 34.3% decrease, respectively; due to decreased hepatic CYP2C11) than in their respective controls. After oral administration of metformin (100 mg/kg) to rat model of DMIS, the AUC became significantly smaller (18.6% and 33.7% decrease for the 7th and the 29th days, respectively) than in their respective controls. The CL(NR) of metformin were comparable between two rat models of DMIS.

Selective Embolization for Post-Endoscopic Sphincterotomy Bleeding: Technical Aspects and Clinical Efficacy

Objective The objective of this study was to evaluate the technical aspects and clinical efficacy of selective embolization for post-endoscopic sphincterotomy bleeding. Materials and Methods We reviewed the records of 10 patients (3%; M:F = 6:4; mean age, 63.3 years) that underwent selective embolization for post-endoscopic sphincterotomy bleeding among 344 patients who received arteriography for nonvariceal upper gastrointestinal bleeding from 2000 to 2009. We analyzed the endoscopic procedure, onset of bleeding, underlying clinical condition, angiographic findings, interventional procedure, and outcomes in these patients. Results Among the 12 bleeding branches, primary success of hemostasis was achieved in 10 bleeding branches (83%). Secondary success occurred in two additional bleeding branches (100%) after repeated embolization. In 10 patients, post-endoscopic sphincterotomy bleedings were detected during the endoscopic procedure (n = 2, 20%) or later (n = 8, 80%), and the delay was from one to eight days (mean, 2.9 days; ± 2.3). Coagulopathy was observed in three patients. Eight patients had a single bleeding branch, whereas two patients had two branches. On the selective arteriography, bleeding branches originated from the posterior pancreaticoduodenal artery (n = 8, 67%) and anterior pancreaticoduodenal artery (n = 4, 33%), respectively. Superselection was achieved in four branches and the embolization was performed with n-butyl cyanoacrylate. The eight branches were embolized by combined use of coil, n-butyl cyanoacrylate, or Gelfoam. After the last embolization, there was no rebleeding or complication related to embolization. Conclusion Selective embolization is technically feasible and an effective procedure for post-endoscopic sphincterotomy bleeding. In addition, the posterior pancreaticoduodenal artery is the main origin of the causative vessels of post-endoscopic sphincterotomy bleeding.