Biliary stone removal through the percutaneous transhepatic biliary drainage route, focusing on the balloon sphincteroplasty flushing technique: a single center study with 916 patients.

PURPOSE: To present our experience in biliary stone removal (BSR) through the percutaneous transhepatic biliary drainage (PTBD) route in 916 patients, and discuss its clinical usefulness. MATERIALS AND METHODS: From 2001 to 2015, 916 patients (479 male patients and 437 female patients; age range, 22-92 years; mean age, 67 years) with 52 recurring cases, so a total of 968 cases, were enrolled in this study and retrospectively reviewed. PTBD was performed in all patients. BSR was performed using a combination of a balloon sphincteroplasty flushing technique, a pushing technique after sphincteroplasty, and classical extraction technique, decided case by case. RESULTS: A complete removal was achieved in 893 cases (92.3%) and the overall clinical success rate was 99.3%. Failure occurred in 7 cases (0.7%), and the causes of failure were stone impaction (n = 5) and intrahepatic bile duct stricture (n = 2). Sphincteroplasty was performed in 902 cases (93.2%). Balloon sphincteroplasty flushing technique was used in 829 (85.6%) cases. There was no major complication. Transient minor complications were seen in 86 cases (8.9%). CONCLUSIONS: BSR through the PTBD route using a combination of techniques, including balloon sphincteroplasty flushing, is a safe and effective treatment modality to remove biliary stones.

MRI traceability of superparamagnetic iron oxide nanoparticle-embedded chitosan microspheres as an embolic material in rabbit uterus.

PURPOSE: We aimed to compare polyvinyl alcohol (PVA) particles with calibrated superparamagnetic iron oxide (SPIO) nanoparticle-loaded chitosan microspheres in a rabbit model, specifically regarding the relative distribution of embolic agents within the uterus based on magnetic resonance imaging (MRI) and pathological evaluation. METHODS: Twelve New Zealand white rabbits underwent uterine artery embolization using either standard PVA particles (45-150 µm or 350-500 µm) or calibrated SPIO-embedded chitosan microspheres (45-150 µm or 300-500 µm). MRI and histopathological findings were compared one week after embolization. RESULTS: Calibrated SPIO-loaded chitosan microspheres 45-150 µm in size were detected on T2-weighted images. On histological analysis, calibrated SPIO-embedded chitosan microspheres were found in both myometrium and endometrium, whereas PVA particles were found only in the perimyometrium or extrauterine fat pads. A proportional relationship was noted between the calibrated SPIO-embedded chitosan microsphere size and the size of the occluded artery. CONCLUSION: Calibrated SPIO-embedded chitosan microspheres induced greater segmental arterial occlusion than PVA particles and showed great potential as a new embolic material. SPIO-embedded chitosan microspheres can be used to follow distribution of embolic particles through MRI studies.

Papillary thyroid carcinoma in children and adolescents.

Differentiated thyroid carcinoma is uncommon in children and constitutes 0.5% to 3% of all pediatric malignancies. Few studies have reported imaging findings of childhood papillary thyroid carcinomas. We report 3 cases of papillary thyroid carcinomas in children. Among the 3 patients, the youngest was a 7-year-old girl. In the current report, we describe 2 cases of classic papillary thyroid carcinoma and 1 case of pediatric diffuse sclerosing variant of papillary thyroid carcinoma. The ultrasonographic features and diagnostic procedures in these pediatric patients are similar to those in adults.

Comparison of brain activation in response to two dimensional and three dimensional on-line games.

OBJECTIVE: The present study assessed the difference in the brain activity of professional gamers (excessive players, but not addicts) in response to playing a 3-dimensional online game with an improved interface. METHODS: Twenty-three StarCraft I pro gamers and 16 StarCraft II pro gamers were recruited at Chung Ang University Medical Center. Brain activity in response to StarCraft I or II cues was assessed with a 1.5 Tesla Espree MRI scanner. RESULTS: StarCraft I pro gamers showed significantly greater activity in 4 clusters in response to the video game cues compared to StarCraft II pro gamers: right superior frontal gyrus, right medial frontal gyrus, right occipital lobe, and left medial frontal gyrus. StarCraft II pro gamers showed significantly greater activity in 3 clusters in response to the video game cues compared to StarCraft I pro gamers: left middle frontal gyrus, left temporal fusiform gyrus and left cerebellum. DISCUSSION: This is the first study to show the difference in brain activity between gamers playing either a 2-dimensional or 3-dimensional online game. Current brain imaging studies may confirm the pro gamers' experience when playing StarCraft II, a 3-dimensional game with an improved interface, relative to playing StarCraft I.

A long-term outcome of therapeutic angiogenesis by transplantation of peripheral blood stem cells in critical limb ischemia after interventional revascularization.

A 61-year-old male patient with atherosclerotic critical limb ischemia in the left leg underwent stent insertion into the left superficial femoral artery. Stenting procedures improved Rutherford grade from III-5 to II-4. Granulocyte colony-stimulating factor stimulated the production of white blood cells over four-fold and mononuclear cells (MNCs) 1.5-fold in the whole blood. Transplantation of 7.9x10(9) autologous MNCs into the left femoral artery rapidly decreased the leg pain intensity, with further improvement of Rutherford grades from II-4 to 0-0 without any side effects. In the four-year follow-up, significant improvement was found in terms of ankle brachial index, from nondetectable to 0.67, and peak systolic velocity, from 14.8 to 36.1 cm/s. Limb salvage and decreased resting pain were the notable outcomes of the treatment.

A radiofrequency electrode catheter-guide wire system for arterial occlusion.

PURPOSE: To describe the design of a radiofrequency (RF) electrode catheter/guide wire system to allow endovascular coagulation of vessels. MATERIALS AND METHODS: A circuit was created by modifying an ordinary microcatheter. An electrically conductive ring was placed at a microcatheter tip, and an extension lead at the hub site. They were each connected to an inherent coil mesh. The rings (ie, cathodes) were 1, 3, 5, 10, and 20 mm in length. In egg white, a coagulation study was performed by changing the length of the guide wire (ie, anode; 1, 3, 5, 10, 20, and 40 mm) in each cathode at 20 W. The coagulation time and site were analyzed. In rabbits, the renal artery was ablated with the use of a 20-mm cathode and 10-mm anode. RESULTS: In the egg white study, the coagulation time was proportionally increased and was dependent on the lengths of the cathode and anode (P < .05). Coagula developed at the anode to the 3-mm protrusion for the 1-mm cathode, to the 5-mm protrusion for the 3-mm cathode, to the 5-mm protrusion for the 5-mm cathode, to the 10-mm protrusion for the 10-mm cathode, and to the 20-mm protrusion for the 20-mm cathode. In rabbits, the renal artery was successfully occluded. Pathologic examination showed occlusion of the renal artery with organization, and the presence of a necrotic arterial wall with fibrosis, inflammation, and intact internal elastic lamina. CONCLUSIONS: The RF electrode catheter/guide wire system successfully coagulated egg white and occluded the rabbit renal artery.

In vivo tracking of mesenchymal stem cells labeled with a novel chitosan-coated superparamagnetic iron oxide nanoparticles using 3.0T MRI.

This study aimed to characterize and MRI track the mesenchymal stem cells labeled with chitosan-coated superparamagnetic iron oxide (Chitosan-SPIO). Chitosan-SPIO was synthesized from a mixture of FeCl(2) and FeCl(3). The human bone marrow derived mesenchymal stem cells (hBM-MSC) were labeled with 50 microg Fe/mL chitosan-SPIO and Resovist. The labeling efficiency was assessed by iron content, Prussian blue staining, electron microscopy and in vitro MR imaging. The labeled cells were also analyzed for cytotoxicity, phenotype and differentiation potential. Electron microscopic observations and Prussian blue staining revealed 100% of cells were labeled with iron particles. MR imaging was able to detect the labeled MSC successfully. Chitosan-SPIO did not show any cytotoxicity up to 200 microg Fe/mL concentration. The labeled stem cells did not exhibit any significant alterations in the surface markers expression or adipo/osteo/chondrogenic differentiation potential when compared to unlabeled control cells. After contralateral injection into rabbit ischemic brain, the iron labeled stem cells were tracked by periodical in vivo MR images. The migration of cells was also confirmed by histological studies. The novel chitosan-SPIO enables to label and track MSC for in vivo MRI without cellular alteration.

Placement of stents in proximal colonic obstructions using a percutaneous retroperitoneal colostomy.

In cases of proximal colonic obstruction, the long distances and the tortuosity of the distal bowel make it difficult to advance and position the stent in the target lesion. We report 2 cases of stent placement for malignant obstruction of the proximal colon in which access was obtained through percutaneous retroperitoneal colostomy. In these cases, we initially tried to place a stent through the rectum under endoscopic guidance, but it was not possible to reach the lesion. We then decided to cross the lesion through percutaneous puncture of the retroperitoneum. The procedures were completed without complications and the patients' symptoms improved. A percutaneous retroperitoneal approach for the deployment of colonic stents has not been described earlier in the literature. We suggest that our technique provides an alternative means of colonic decompression in cases in which conventional retrograde methods fail to provide acceptable palliation in nonsurgical candidates.

Endovascular treatment for common iliac artery injury complicating lumbar disc surgery : limited usefulness of temporary balloon occlusion.

Vascular injury during lumbar disc surgery is a rare but potentially life-threatening complication. It has been managed by open vascular surgical repair. With recent technologic advance, endovascular treatment became one of effective treatment modalities. We present a case of a 32-year-old woman who suffered with common iliac artery injury during lumbar disc surgery that was treated successfully by endovascular repair with temporary balloon occlusion and subsequent insertion of a covered stent. Temporary balloon occlusion for 1.5 hours could stop bleeding, but growing pseudoaneurysm was identified at the injury site during the following 13 days. It seems that the temporary balloon occlusion can stall bleeding from arterial injury for considerable time duration, but cannot be a single treatment modality and requires subsequent insertion of a covered stent.

Functional characterization of mesenchymal stem cells labeled with a novel PVP-coated superparamagnetic iron oxide.

Magnetic resonance imaging of cells labeled with superparamagnetic iron oxide (SPIO) could be a valuable tool for tracking transplanted cells in living organisms. Human bone marrow-derived mesenchymal stem cells (hBMMSC) were labeled with a novel polyvinyl pyrrolidone (PVP)-coated SPIO. Prussian blue staining and electron microscopy revealed that almost all of the cells were efficiently labeled with PVP-SPIO nanoparticles. There were no signs of cytotoxicity, even at concentrations of up to 1600 microg Fe/ml of the nanoparticles, and the labeled cells were successfully visualized by in vitro cellular MRI. In addition, there was no significant alteration of the phenotype or the adipo/osteo/chondrogenic differentiation potential of the cells. This was in contrast to Feridex IV labeling that led to the inhibition of hBMMSC chondrogenesis. Following intramuscular injection in a rabbit hind limb ischemia model, the intercellular migration of the labeled cells toward the ablated site was clearly tracked through in vivo MRI. The localization of the transplanted cells observed by MRI correlated well with postmortem histological studies. These results demonstrate that the novel PVP-SPIO nanoparticles appear to be efficient MR contrast agents and may enable non-invasive in vivo tracking of stem cells in experimental and clinical settings during cell therapy.

Retrievable biliary stent-graft in the treatment of benign biliary strictures.

PURPOSE: To investigate the technical and clinical efficacy of a retrievable stent-graft in the treatment of benign biliary strictures. MATERIALS AND METHODS: From February 2004 to December 2006, 29 patients with 32 benign biliary strictures (17 patients with 18 chronic cholangitis strictures and 12 with 14 postoperative strictures) were enrolled in this study. Twenty-four patients had 26 recurrent strictures despite prolonged catheter interposition after balloon dilation procedures. Five patients with six strictures had not previously undergone interventional treatment. A total of 36 stent-grafts were placed, and all stent-grafts were removed by means of a percutaneous route or via a T-tube 6.7 weeks (range, 2-10 weeks) after stent-graft placement. RESULTS: The retrievable stent-grafts were successfully placed and removed in all cases. Migration occurred in four of the 36 (11%) stent-grafts (11%). Immediately after stent-graft removal, all strictures were widened significantly. From 2 days to 8 weeks after removal, 29 of 32 lesions (91%) remained patent with or without recurrence of minimal strictures. During the mean follow-up of 27.9 months (range, 9-34 months), none of the 29 lesions had recurrence of clinically significant strictures. The primary patency rate was 90.6%. Three additional stent-graft placements for recurrent stricture were required in three lesions (9.4%). During a mean follow-up of 13.3 months (range, 9-16 months), two patients had no evidence of biliary obstruction. The secondary patency rate and clinical success rate was 97% (31 of 32 lesions). CONCLUSIONS: The placement and removal of a retrievable stent-graft in the treatment of benign biliary strictures is technically feasible and appears to be a clinically effective method.

Arterial occlusion using a microguidewire as a radiofrequency electrode.

PURPOSE: To illustrate the use of superselective radiofrequency (RF) energy delivery for arterial occlusion in vessels requiring embolization. TECHNIQUE: A 3.0-F microcatheter and a 0.016-inch stainless steel microguidewire coated with polytetrafluoroethylene except for the floppy platinum-coiled tip are inserted into the diseased arteries. After positioning the microcatheter at the target site, the floppy tip of the microguidewire is advanced 1 to 2 cm beyond the microcatheter to act as an electrode. RF ablation is performed at a power of 20 watts until there was a rise in uncontrolled impedance. If occlusion is incomplete, embolic agents can be applied. The use of the technique is illustrated in 4 cases, 3 involving renal branch arteries and a large arteriovenous malformation in the buttock. RF energy was successful in occluding the target vessels in 3 cases; the other required additional embolization. There were no complications, and the patients had sustained occlusion of the lesions. CONCLUSION: Diseased arteries can be endovascularly occluded using a microguidewire to deliver radiofrequency energy. However, further development of the technique is needed to circumvent wire adhesion to the arterial wall and optimize RF delivery to avoid damage to adjacent structures.

A new ischemic model using a radiofrequency wire electrode in a rabbit hindlimb.

The purpose of this study was to establish an ischemic rabbit hindlimb model using a radiofrequency (RF) wire electrode. We inserted a polytetrafluoroethylene-coated wire with a 2-cm exposed tip into the left superficial femoral artery of seven New Zealand white rabbits and performed RF ablation (RFA) while pulling the wire back. We assessed the clinical findings, angiography, computed tomography perfusion, and permeability surface until 6 weeks after RFA. The angiography demonstrated complete obstruction from the proximal external iliac artery to the distal superficial femoral artery and showed a gradual increment in the angiogenic score, which represents the degree of angiogenesis (r = 0.86, p < 0.0001). The left-to-right ratios of the computed tomography perfusion and permeability surface were significantly reduced after 4 days (p < 0.05), and then they gradually increased with time. We conclude that endovascular RFA using an RF wire electrode is a reproducible and measurable way to create an ischemic rabbit hindlimb model.

Treatment of high-flow priapism with superselective transcatheter embolization in 27 patients: a multicenter study.

PURPOSE: To evaluate the effectiveness and safety of treatment of high-flow priapism (HFP) with superselective transcatheter embolization at nine university hospitals. MATERIALS AND METHODS: Between May 1994 and October 2006, 27 patients underwent superselective embolization of the cavernous artery for HFP. Trauma was apparent in 22 patients, there was self-administered intracavernosal injection for erectile dysfunction in two, and the remaining three did not recall any penile or perineal trauma. The embolic agents used were autologous blood clot (n = 12), gelatin sponge (n = 12), microcoils combined with gelatin sponge (n = 1), polyvinyl alcohol (n = 1), and N-butyl cyanoacrylate (n = 1). Recurrence of priapism and change in erectile function were evaluated during a mean follow-up of 13 months. Differences in results between patients treated with autologous blood clot versus gelatin sponge were statistically analyzed with use of the chi(2) test. RESULTS: In 24 of 27 patients (89%), a single embolization was sufficient for complete resolution of priapism. Repeat embolization was required in two patients (7%), and in the remaining patient (4%), shunt surgery was performed after embolization as a result of HFP coexisting with corporeal venoocclusive dysfunction. Eighteen of 23 patients (78%) who had premorbid normal erectile function showed maintained potency during the follow-up period. There was no significant difference affecting required repeat embolization (P = .537) and change in quality of erection (P = .615) during the follow-up period between the autologous blood clot and gelatin sponge treatment groups. CONCLUSIONS: Superselective transcatheter embolization in the treatment of HFP is effective and ensures a high level of preservation of premorbid erectile function.

Chitin-based embolic materials in the renal artery of rabbits: pathologic evaluation of an absorbable particulate agent.

PURPOSE: To prospectively evaluate the tissue reaction to and the embolic effect and absorption of chitin and chitosan microspheres and polyvinyl alcohol (PVA) in the renal artery of rabbits. MATERIALS AND METHODS: This experiment was performed in accordance with regulations on animal care and experiments. Thirty-six New Zealand white rabbits were divided into four groups according to the materials (PVA, chitin particles, and chitosan particles, and chitosan microspheres; diameter, 150-250 microm) used for embolization of the right renal artery. A rabbit from each group was sacrificed 1 and 3 days and 1, 2, 4, 8, 16, 24, and 32 weeks after embolization. Gross and microscopic pathologic findings were examined with hematoxylin-eosin, Masson trichrome, and Victoria blue staining. RESULTS: Gross pathologic findings were examined, and swelling of embolized kidneys was observed 1 and 3 days after embolization, whereas shrinkage of the embolized kidneys was consistently seen after 2 weeks, with a hard consistency and nodular surfaces being noted. At histologic analysis, chitosan microspheres filled the lumen more compactly than did other particles. With PVA, a large amount of capillary formations occurred within the embolized arteries, whereas chitin particles and chitosan microspheres showed a lower rate of capillary formation. The shape of all embolic materials remained intact until week 8, at which time the materials gradually decreased in size and number. The chitosan particles and the chitosan microspheres were absorbed around weeks 16 and 24, respectively. CONCLUSION: Chitosan microspheres have great potential as a new embolic material since they block blood vessels more compactly with a lower rate of capillary formation. This material is biocompatible, and it is absorbed 24 weeks after embolization.

Fixation methods for implantable port chamber: comparative study using glue, self-stabilizing leg and suture fixations in rabbits.

OBJECTIVE: To evaluate the fixation strength and tissue reaction of the glue fixation and self-stabilizing leg fixation methods and to compare the results with those of the conventional tagging suture fixation method. MATERIALS AND METHODS: Twelve healthy rabbits were selected and three different methods of implanting the port chamber were employed on the back of each rabbit. A total of thirty six port chambers were implanted with these three different methods, viz. the glue fixation method using tissue adhesive, the self-stabilizing leg method using a self-expandable stabilizing leg, and the suture fixation method. The fixation strength and the gross and histopathologic changes of each fixation method were evaluated at three days, one week, two weeks and four weeks after port implantation. RESULTS: The glue fixation method showed a good fixation strength, which was similar to that of the tagging suture method (p = 0.3486). Five of the six ports (83%) implanted with the glue fixation method which were examined after two weeks showed cracks on the external surface, but this had no adverse effects on their function. A large amount of granulation tissue reaction was found at the bottom of the chamber (p = 0.0025). The fixation with the self-stabilizing leg showed relatively lower fixation strength (p = 0.0043), but no turning-over of the chamber occurred. The fixation strength improved with time after the first week, and minimal granulation tissue reaction was observed with this method. CONCLUSION: The glue fixation method exhibited equal fixation strength compared to the suture fixation, but showed cracking and a large amount of granulation tissue, whereas the fixation with a self-stabilizing leg showed weaker fixation strength.

Cirsoid Aneurysms of the Scalp: Report of Three Cases

The arteriovenous fistula and cirsoid aneurysm, characterised by abnormal arterial and venous connections with grossly dilated and expansile mass of vessels, may predispose to dramatic complications. Cirsoid aneurysms of the scalp have been reported to be difficult to remove. Multiple treatment schemes have been described and, as yet, no standard form of therapy exists. Three cases of cirsoid aneurysms of the scalp are presented. Each of them was treated with embolization and total excision after ligation of the feeding arteries. All of them were well cured.