Kimihiko Sugiura

CT-guided transthoracic needle biopsy using a puncture site-down positioning technique.

OBJECTIVEnWe have developed a new CT-guided technique using puncture site-down positioning during the biopsy. The goal of our study was to determine the efficacy and safety of this technique for biopsy of lung lesions compared with the standard technique.nnnMATERIALS AND METHODSnMedical records of 236 patients who underwent CT-guided transthoracic needle biopsy were retrospectively evaluated. This study included 89 cases that were biopsied using the standard technique (group A) and 147 cases that were biopsied using the puncture site-down positioning technique (group B). A 20-gauge automated cutting needle without coaxial technique was used in all patients. Medical records were reviewed for lesion size and location, biopsy results, and complications.nnnRESULTSnWhen using the standard technique, the sensitivity for malignant lesions was 96.1%; the sensitivity for benign lesions, 92.1%; and diagnostic accuracy, 94.4%. Thirty-seven patients (41.6%) had pneumothorax, with 16 (18.0%) requiring chest tube placement. When using the puncture site-down positioning technique, the sensitivity for malignant lesions was 95.4%; the sensitivity for benign lesions, 93.3%; and diagnostic accuracy, 94.6%. Nineteen patients (12.9%) had pneumothorax, with four (2.7%) requiring chest tube placement. Other complications were minimal.nnnCONCLUSIONnCT-guided transthoracic needle biopsy using the puncture site-down positioning technique is an effective and safe procedure with a high diagnostic accuracy and low complication rate. This new technique is especially useful in reducing the rate of pneumothorax.

Heat Distribution in the Spinal Canal during Radiofrequency Ablation for Vertebral Lesions : Study in Swine

PURPOSEnTo prospectively evaluate the safety of radiofrequency (RF) ablation for vertebral lesions by monitoring the temperature in swine vertebral models with and without a cortical bone defect.nnnMATERIALS AND METHODSnThe institutional animal care and use committee approved the animal studies. In vivo and ex vivo studies were performed. In the in vivo study, 20 lumbar vertebrae from six swine were locally heated by using 1- or 2-cm active-tip internally cooled electrodes. In the ex vivo study, 12 fresh pig cadaver lumbar vertebrae were extracted from four swine, and spinal tumor models with or without cortical bone defect were created by stuffing a cavity with muscle tissue and locally heated by using a 1-cm active-tip internally cooled electrode. The temperature was monitored in the spinal canal and around the vertebral body during ablation. Mann-Whitney U test was used to indicate a significant difference between groups by using 1- and 2-cm active tip in the in vivo study and between groups with and without cortical defect in the ex vivo study.nnnRESULTSnIn the in vivo study in which 1- and 2-cm active-tip needles were used, the temperature in the spinal canal rose to 38.2 degrees C +/- 2.7 (standard deviation) and 45.5 degrees C +/- 6.2, respectively. The latter was significantly higher than the former (P < .001). In the ex vivo study in which tumor models with or without a cortical bone defect were used, the temperature in the spinal canal rose to 48.4 degrees C +/- 6.2 and 31.3 degrees C +/- 3.4, respectively. The former was significantly higher than the latter (P < .001).nnnCONCLUSIONnFor in vivo cases with a 2-cm active tip and ex vivo cases with a vertebral posterior bone defect, the temperature rose to over 45 degrees C, potentially injuring the spinal cord and peripheral nerves.

Creation of a Tumor-Mimic Model Using a Muscle Paste for Radiofrequency Ablation of the Lung

The purpose of this study was to develop an easily created tumor-mimic model and evaluate its efficacy for radiofrequency ablation (RFA) of the lung. The bilateral lungs of eight living adult swine were used. A tumor-mimic model was made by percutaneous injection of 1.0xa0ml muscle paste through the bone biopsy needle into the lung. An RFA probe was then inserted into the tumor mimics immediately after tumor creation. Ablation time, tissue impedance, and temperature were recorded. The tumor mimics and their coagulated regions were evaluated microscopically and macroscopically. The muscle paste was easily injected into the lung parenchyma through the bone biopsy needle and well visualized under fluoroscopy. In 10 of 12 sites the tumor mimics were oval shaped, localized, and homogeneous on gross specimens. Ten tumor mimics were successfully ablated, and four locations were ablated in the normal lung parenchyma as controls. In the tumor and normal lung parenchyma, ablation times were 8.9xa0±xa03.5 and 4.4xa0±xa01.6xa0min, respectively; tissue impedances at the start of ablation were 100.6xa0±xa016.6 and 145.8xa0±xa026.8 Ω, respectively; and temperatures at the end of ablation were 66.0xa0±xa07.9 and 57.5xa0±xa07.6°C, respectively. The mean size of tumor mimics was 13.9xa0×xa08.2xa0mm, and their coagulated area was 18.8xa0×xa013.1xa0mm. In the lung parenchyma, the coagulated area was 15.3xa0×xa012.0xa0mm. In conclusion, our tumor-mimic model using muscle paste can be easily and safely created and can be ablated using the ablation algorithm in the clinical setting.

Development of a New Hanging-Type Esophageal Stent for Preventing Migration: A Preliminary Study in an Animal Model of Esophagotracheal Fistula

PurposeCovered, self-expandable metallic stents (SEMS) have been enthusiastically adopted for the treatment of esophagotracheal fistula, but problems with stent migration have yet to be resolved. To overcome this problem, we have developed a new hanging-type esophageal stent designed to prevent migration, and we conducted an animal study to assess the efficacy of our method.MethodsA total of six female pigs were used in this study. The main characteristic of our stent was the presence of a string tied to the proximal edge of the stent for fixation under the skin of the neck. The first experiment was performed to confirm technical feasibility in three pigs with esophagotracheal fistula. The second experiment was performed to evaluate stent migration and esophagotracheal fistula in three pigs.ResultsCreation of the esophagotracheal fistula and stent placement were technically successful in all pigs. In the first experiment, esophagotracheal fistula was sealed by stent placement. In the second experiment, no stent migration was seen 11 or 12xa0days after stent placement. Gross findings showed no fistulas on the esophageal or tracheal wall.ConclusionsOur new hanging-type esophageal stent seems to offer a feasible method for preventing stent migration.

Successful closure of intractable tracheoesophageal fistula using a combination of a modified silicon stent and metallic stents.

Although surgery is the usual management strategy for acquired benign tracheoesophageal fistula, sometimes this approach is contraindicated or the patient declines surgical management. In this report, we describe a case of a patient with tracheoesophageal fistula at the level of the carina due to bronchial arterial infusion chemotherapy. Closure could not be achieved in response to multiple treatment strategies, including airway stenting, esophageal stenting, occlusion with microcoils, or cyanoacrylate glue. We subsequently achieved closure of this fistula through the combination of a modified silicon stent and metallic stents.

Localization of chyle leakage site in postoperative chylothorax by oral administration of I-123 BMIPP.

The authors present a 71-year-old woman who had a right chylothorax after right upper lobectomy for lung cancer. As the chylothorax was considered to be due to thoracic duct injury at the time of operation, lymphoscintigraphy was performed by oral administration of I-123 beta-methyl-iodophenyl pentadecanoic acid (BMIPP). After visualization of the stomach and intestine, abnormal accumulation of the radiotracer was found initially around the right pulmonary hilum and then spread laterally in the upper pleural cavity, indicating chyle leakage in the region of the right pulmonary hilum. Scintigraphic finding was well correlated with the subsequent thoracoscopic observation, showing chyle leakage from a lymphatic tributary near its confluence to the thoracic duct at the level of the azygos continuation. The disruption site was ligated by video-assisted-thoracoscopic-surgery procedure with successful termination of the chyle leakage. Lymphoscintigraphy by oral administration of I-123 BMIPP is thought to be a useful method for localization of chyle leakage in patients with chylothorax induced by thoracic surgery.

Endovascular Treatment of Left Subclavian Artery Pseudoaneurysm after Clavicle Fracture in an Elderly Adult with a 40-Year History of Behçet’s Disease

Behçets disease (BD) is a rare chronic systemic vasculitis of unknown etiology that presents in young adults. We report a very rare case of a left subclavian artery pseudoaneurysm identified after a left clavicle fracture in a 70-year-old man with a 40-year history of intestinal BD. The patient received fixation by banding to treat a fracture after falling from a bed about 5 months previously, and he was referred to our hospital due to the finding of a left subclavian pulsatile mass. As enhanced computed tomography showed a left subclavian artery pseudoaneurysm, it was repaired using an endovascular stent graft.

Balloon-assisted coil embolization of the celiac trunk before endovascular aortic repair of thoracoabdominal aortic aneurysm.

PurposeCeliac trunk coil embolization before thoracic endovascular aneurysm repair (TEVAR) of a thoracoabdominal aortic aneurysm involving the celiac trunk can prevent type II endoleaks. One disadvantage of conventional coil embolization is the risk of coil displacement. We performed coil embolization under balloon occlusion of the celiac trunk to address this issue.Materials and methodsBetween December 2008 and January 2011, 5 patients (3 men and 2 women, mean age 76xa0years) were included in this study. For all patients, after confirming the collateral blood flow from the superior mesenteric artery via the pancreaticoduodenal arcades by using the balloon occlusion test, celiac trunk coil embolization proceeded under balloon occlusion of the proximal part of the celiac trunk.ResultsBalloon-assisted coil embolization of the celiac trunk was completed for all patients without any complications. All coils were deployed as planned in the short segment of the celiac trunk without displacement. Coil migration, ischemic complications, and endoleaks via the celiac trunk did not arise in any of the patients over a follow-up period of 77–637 (mean 258) days.ConclusionsBalloon-assisted coil embolization of the celiac trunk before TEVAR could be a feasible treatment option for suitable patients.

Influence of ethanol-induced pulmonary embolism on hemodynamics in pigs

AIMS AND OBJECTIVESnEthanol is widely used for the embolization treatment of vascular malformations, but it can also cause serious complications such us pulmonary hypertension, cardiopulmonary collapse and death. The complications are considered secondary to pulmonary vasospasm and ethanol-induced sludge embolism, etc., We studied the hemodynamic effects of intravenous absolute ethanol injection and ethanol sludge injection in pigs.nnnMATERIALS AND METHODSnA total of 5 pigs underwent intravenous injection of ex vivo generated ethanol-induced sludge in which residual ethanol was removed (Group S) and 4 pigs underwent intravenous injection of absolute ethanol (Group E). Hemodynamic parameters related to the pulmonary and systemic circulation were compared between the groups.nnnRESULTSnTransient pulmonary hypertension was observed in both groups and the hemodynamic changes were similar in both groups.nnnCONCLUSIONSnSludge can induce transient pulmonary hypertension or cardiopulmonary collapse, without ethanol and may be the mechanism by which ethanol induces its adverse hemodynamic effects.

Successful removal of a trapped biliary metallic stent delivery catheter using the percutaneous approach.

Endoscopic biliary self-expandable metallic stent insertion via the papilla of Vater is a treatment of choice for malignant biliary obstruction caused by unresectable biliary neoplasms. Stent migration is a problem after stent insertion. The clinical presentations of patients with stent migration include stent malfunction and perforation of the intestinal wall [1, 2]. It is a relatively rare complication for a stent delivery catheter to migrate and become trapped. An interesting case of successful removal of a trapped delivery catheter through the percutaneous approach is reported.