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In our institution, computed tomography (CT)-guided percutaneous cryoablation has been performed in patients with malignant lung tumors under local anesthesia. This study aimed to examine the feasibility and safety of percutaneous cryoablation for the treatment of malignant lung tumors.From July 2002 to December 2016, 227 patients (56 with primary lung cancer and 171 with metastatic lung tumor) underwent percutaneous cryoablation for the treatment of malignant lung tumors using a cryosurgical unit at our institution. Demographic factors, duration of post-treatment hospitalization, and adverse event and mortality rates were retrospectively investigated in 366 treatment sessions targeting 609 lesions.The median diameter of the targeted tumor was 1.3 cm. All the cryoablation procedures were completed under local anesthesia, and the median duration of post-treatment hospitalization was two days. Adverse events (grade 2 or higher) were observed in 79 sessions (21.6%), with pneumothorax being the most common. In five sessions (1.4%), patients had grade 3 adverse events. There was no 30-day mortality; however, there were two 60-day mortality (0.5%) due to acute exacerbation of interstitial pneumonia. In multivariate analysis, independent predictors of adverse events were comorbid interstitial pneumonia [odds ratio (OR) =2.20; 95% confidence interval (CI): 1.04-4.64] and no history of pulmonary resection on the treated side (OR =3.04; 95% CI: 1.65-5.62).Cryoablation is a feasible and safe treatment for malignant lung tumors with acceptable adverse event rates. However, the mortality risk in patients with comorbid interstitial pneumonia should be fully recognized.

To reveal the effect of drug-eluting beads transarterial chemoembolization and Lipiodol transarterial chemoembolization on portal perfusion, and to identify factors predisposing portal vein damage after transarterial chemoembolization, based on evaluation by computed tomography during arterial portography.This retrospective cohort analysis included 49 patients with hepatocellular carcinoma who underwent transarterial chemoembolization and preprocedural/follow-up computed tomography during arterial portography between October 2013 and April 2015. The preprocedural and follow-up computed tomography during arterial portography were compared to identify the following new changes suggestive of portal vein damage in the follow-up computed tomography during arterial portography: small perfusion defects, large perfusion defects, and narrowing/disappearance or portal vein obstruction. The frequency of portal vein damage after drug-eluting beads transarterial chemoembolization and Lipiodol transarterial chemoembolization was calculated, and relationships between portal vein damage and clinical variables were analyzed. Finally, a multivariate logistic regression analysis with adjustments for potentially confounding factors was performed to identify factors predisposing portal vein damage.The analysis included 24 patients who underwent drug-eluting beads transarterial chemoembolization and 25 who underwent Lipiodol transarterial chemoembolization. Emergence of small perfusion defects and narrowing/disappearance or obstruction of portal vein were observed at a significantly higher frequency following drug-eluting beads transarterial chemoembolization than following Lipiodol transarterial chemoembolization (70.8% [17/24] vs. 20% [5/25]; p0.001; 41.7% [10/24] vs. 12% [3/25]; p = 0.019). Drug-eluting beads transarterial chemoembolization and selectivity of transarterial chemoembolization (selective [subsegmental], segmental or lobar) were significantly associated with portal vein damage (p0.001 and p = 0.016, respectively). However, multivariate logistic regression analysis identified drug-eluting beads transarterial chemoembolization as a significant independent predictor of portal vein damage (odds ratio: 34.95; 95% confidence interval: 1.137-1073.99; p = 0.042).Portal vein damage occurred at a significantly higher frequency following drug-eluting beads transarterial chemoembolization than following Lipiodol transarterial chemoembolization, and drug-eluting beads transarterial chemoembolization was an independent predictor of portal vein damage after transarterial chemoembolization.

OBJECTIVES The actual incidence of cerebral infarction (CI), including asymptomatic infarction, owing to thoracic endovascular aortic repair (TEVAR) has not been reported in detail. This study was performed to investigate the incidence of post-TEVAR CI by using diffusion-weighted magnetic resonance imaging (DW-MRI) and to determine the risk factors for both symptomatic and asymptomatic CI. METHODS We examined 64 patients undergoing TEVAR at our institute between April 2017 and November 2020. Aortic atheroma was graded from 1 to 5 by preoperative computed tomography. Cerebral DW-MRIs were conducted 2 days after the procedure to diagnose postoperative CI. RESULTS A total of 44 new foci were detected by post-interventional cerebral DW-MRI in 22 patients (34.4%). Only one patient developed a symptomatic stroke (1.6%), and TEVAR was successfully completed in all cases. Debranching of the aortic arch and left subclavian artery occlusion with a vascular plug was performed in 19 (29.7%) and 12 (18.8%) patients, respectively. The number of patients with proximal landing zones 0–2 was significantly higher in the CI group than in the non-CI group (68.2% vs 11.9%; P CONCLUSIONS Over one-third of the patients examined by cerebral DW-MRI after TEVAR were diagnosed with CI. High-grade atheroma and TEVAR landing in zone 0–2 were found to be positively associated with asymptomatic CI. Clinical trial registration 02-014.

Background Evaluation of the morphology of the lower urinary tract as well as the movements associated with urination are required for the symptomatic diagnosis of lower urinary tract obstruction as well as the assessment of postoperative adaptation. However, no tool currently exists for direct and easy patient evaluation. Purpose To evaluate lower urinary tract obstruction and postoperative adaptation using a four-dimensional (4D) virtual reality urination image (urodynamic 4D-CT image). Material and Methods We used a 320-row area detector CT scanner and PhyZiodynamics image analysis software to perform 197 urodynamic 4D-CT examinations on 175 first-time patients between January 2014 and March 2017. Results A comparison of the obtained images before and after holmium laser enucleation of the prostate revealed the morphological changes due to prostate enucleation and enabled visualization of the ideal urination conditions, showing that the anatomical structural changes during urination and the opening of the urethra play a major role in improving voiding function. Conclusion Using low-dosage radiation, the sharply defined moving image obtained via urodynamic 4D-CT examination can be utilized as a physiological diagnostic tool to evaluate a series of urinary movements from any angle between the prostate, urethra, and bladder in a unitary manner with the time axis added. There was negligible patient impact. This technique could provide new opportunities for the diagnosis of lower urinary tract symptoms and post-surgical adaptation assessment.

Serous cystic neoplasms are relatively uncommon and rarely possess malignant potential. We report a rare case of pancreatic serous cystadenoma with splenic invasion in a female in her 60s. Dynamic contrast-enhanced CT revealed a 3 cm mass in the tail of the pancreas. The lesion showed marked enhancement in the arterial phase on dynamic CT, which extended into the spleen. No cystic components were detected in the pancreatic mass on either magnetic resonance cholangiopancreatography or T2weighted imaging. No metastasis or lymph node swelling was detected. Based on the hypervascularity of the tumour, the pre-operative diagnosis was pancreatic neuroendocrine tumour with splenic invasion. The patient underwent laparoscopic distal pancreatectomy with splenectomy. The pathological diagnosis was microcystic serous cystadenoma with locally aggressive features (infiltration into spleen, lymph nodes, and splenic vein). A few cases of pancreatic serous cystadenomas with splenic invasion have been reported; all were symptomatic, with diameters greater than approximately 9 cm. This is the first known case of incidentally detected serous cystadenoma with splenic invasion, reported with detailed imaging findings of dynamic CT and MRI.

Background Although a mixture of pigments and radiopaque materials was reported to be useful material for lung nodule localization, the optimal combination has not been well investigated. The purpose of this study is to evaluate the characteristics of various combinations of pigments and radiopaque materials for localization of pulmonary nodules prior to video-assisted thoracic surgery (VATS). Methods We compared stability, viscosity, and visibility of 6 radiopaque dye materials of (I) mixture of indigo carmine and lipiodol; (II) mixture of indigo carmine, lipiodol, and lidocaine gel; (III) mixture of indocyanine green in water solution (w-ICG) and lipiodol; (IV) mixture of w-ICG, lipiodol, and lidocaine gel; (V) ICG in contrast medium solution (cm-ICG); and (VI) mixture of cm-ICG and lidocaine gel. Stability was evaluated by observing changes in the mixtures in the test tube with time visually and radiographically. Viscosities were measured by rotational viscometer. Materials were injected into an expanded pig-lung phantom, and area on CT and visibility on thoracoscopy camera were evaluated. Results Separation could be seen 15 min after preparation in (I) and (III), and 1 h after preparation in (II), both visually and radiographically. In (IV), separation could be seen on the photographs but not on the X-ray images from 3 h after preparation. (V) and (VI) showed no changes within the 2-day observation period. The viscosities of the materials were (I) 0.2±0.1, (II) 2.9±0.1, (III) 0.2±0.1, (IV) 2.6±0.1, (V) 0.2±0.1, and (VI) 1.2±0.1 dPa·s. The area on CT showed very strong negative correlation with viscosity (r=-0.97). The injection point of each material was easily detected on thoracoscopy camera. Conclusions Radiopaque dye materials appear useful for localizing pulmonary nodules before VATS; their diffusion in the lung parenchyma can be suppressed by using materials of high viscosity.

Endovascular approaches to treating a diseased ascending aorta are challenging. We report the use of an endovascular occlusion device for successful closure of a ruptured penetrating atherosclerotic ulcer of an ascending aorta. A 47-year-old female patient with Takayasu arteritis complained of a worsening hemoptysis. She had a history of Bentall procedure for a sinus of Valsalva aneurysm and redo surgery for a ruptured penetrating atherosclerotic ulcer close to the distal anastomosis. She developed methicillin-resistant Staphylococcus aureus (MRSA) mediastinitis after the second procedure and required negative pressure wound therapy. Computed tomographic angiography revealed recurrence of a ruptured penetrating aortic ulcer and an aortobronchial fistula. Because of the high risk of redo sternotomy after MRSA mediastinitis, we used an endovascular occlusion device to achieve successful percutaneous closure. The patient was discharged without any complications. Postoperative computed tomography scans showed that the endovascular device was positioned without migration and that complete thrombosis of the penetrating atherosclerotic ulcer was achieved. This is the first report on endovascular repair of a ruptured penetrating atherosclerotic ulcer of the ascending aorta in Takayasu arteritis.

Traumatic lymphorrhea is a rare but potentially life-threatening complication. Postoperative lymphorrhea is the leading cause of traumatic lymphorrhea and can arise anywhere within the lymphatic system. Leaks arising from the aortoiliac region to the thoracic duct (TD) and from hepatic lymphatics can be identified with intranodal lymphangiography and transhepatic lymphangiography, respectively. Therefore, an appropriate lymphangiography technique is essential for identifying the sources of leaks. Chylothorax resulting from damage to the TD can be serious because the TD transports large amounts of lymphatic fluid from the gastrointestinal, hepatic, and aortoiliac regions. Percutaneous TD embolization-comprising access to the TD followed by embolization-has recently become a minimally invasive alternative to surgical TD ligation for high-output chylothorax. The selection of access routes to the TD depends on its anatomy. If the TD cannot be approached by such means, other options include TD needle interruption or drainage of lymphatic fluid adjacent to the leakage point followed by sclerotherapy. Most cases of abdominal lymphorrhea arise from the aorta-iliac lymphatic system, and lymphangiography alone or computed tomography-guided sclerotherapy might be useful. Rarely, leakage may arise from hepatic lymphatics due to a damaged gastroduodenal ligament and can be visualized and embolized transhepatically. This article comprehensively reviews clinically relevant anatomic TD variations, lymphangiography techniques and criteria for their selection, and treatment strategies for lymphorrhea. ©RSNA, 2016.

Purpose To evaluate the safety and efficacy of a mixture of indigo carmine and lipiodol (MIL) as a marker of pulmonary nodule before video-assisted thoracic surgery (VATS). Materials and Methods One hundred sixty-eight sessions of pulmonary marking were performed using MIL before VATS for 184 nodules (mean size, 1.2 ± 0.6 cm; range, 0.3–3.6 cm) on 157 patients (83 men and 74 women; median age, 66 years). The mean distance between the lung surface and the nodule was 0.8 ± 0.7 cm (range, 0–3.9 cm). MIL was injected near the nodule using a 23-gauge needle. Mean number of 1.2 ± 0.4 (range, 1–3) punctures were performed in a session for the target nodules, with mean number of 1.1 ± 0.3 (range, 1–3). Successful targeting, localization, and VATS were defined as achievement of lipiodol accumulation at the target site on computed tomography, detection of the nodule in the operative field by fluoroscopy or visualization of dye pigmentation, and complete resection of the target nodule with sufficient margin, respectively. Results The successful targeting rate was 100%, and the successful localization rate was 99.5%, with dye pigmentation for 160 nodules (87.0%) and intraoperative fluoroscopy for 23 nodules (12.5%). Successful VATS was achieved for 181 nodules (98.4%). Two nodules (1.1%) were not resectable, and surgical margin was positive in 1 nodule (0.5%). Complications requiring interventions occurred in 5 sessions (3.0%) and included pneumothorax with chest tube placement (n = 3) and aspiration (n = 2). No complication related to the injected MIL occurred. Conclusions MIL was safe and useful for preoperative pulmonary nodule marking.

We evaluated radiological findings and clinical significance of right aortic arch with mirror-image branching (RAMI) in adults using data from computed tomography (CT) examinations.We reviewed recorded reports and CT images obtained from university and branch hospitals for RAMI in adults. The RAMI incidence in adults found on CT was assessed. Associated congenital and acquired cardiovascular diseases were evaluated.A total of 27 cases (14 men, 13 women; mean age, 59.4 ± 18.3 years) of RAMI were found. Among 107,014 cases in three hospitals, the RAMI incidence in the first, second, and third Tokai University hospitals were 0.018%, 0.012%, and 0.012%, respectively. Eight cases had high aortic arches and four cases had aortic diverticulum (AD) in proximal descending aorta. Three cases had a history of tetralogy of Fallot. One case with an absent left pulmonary artery and three cases with an aberrant left brachiocephalic vein were found incidentally. Two cases were associated with AD aneurysm and vascular ring formation. One case had stenosis of the left subclavian artery due to injury.Cases of RAMI found in CT examinations in adults were extremely rare. Some cases were associated with congenital anomalies and/or acquired cardiovascular disease.

A type II endoleak (T2EL) is the most common endoleak after endovascular aneurysm repair (EVAR), and a persistent T2EL has been occasionally associated with aneurysmal enlargement. Typical findings of a T2EL consist of an endoleak cavity with inflow and outflow arteries of aortic branch vessels. However, an atypical T2EL, in which hypertrophied vasa vasorum and enlargement of a thrombosed aneurysm are observed, has no endoleak cavity. We have seen three cases of continuous aortic aneurysmal growth after EVAR caused by atypical T2ELs without endoleak cavities through developed vasa vasorum. In this report, the imaging findings of selective angiography and dynamic computed tomography of these cases are reviewed.

The objective of this retrospective study was to determine the frequency of right adrenal vein identification by computed tomography (CT) during right inferior phrenic arteriography (CTRIPA) and to describe the spectrum of anatomic variations of the right adrenal vein.CTRIPA performed on 104 patients treated with transcatheter arterial chemoembolization (TACE) for hepatocellular carcinoma in our hospital between August 2007 and July 2013 were reviewed. The right adrenal vein on CTRIPA images was evaluated for degree of visualization, anatomic variation, anatomic features, vessel direction, and length. CTRIPA images were compared with dynamic CT before TACE.Partial or entire enhancement of the adrenal gland was obtained in 101 patients. The right adrenal vein was detected using CTRIPA in 97% (98/101) of patients, which was significantly higher than detection using dynamic multidetector CT (MDCT) [77% (78/101)]. Vessel length and diameter averaged 8.5 ± 3.8 and 1.6 ± 0.5 mm, respectively. CTRIPA also showed venous drainage into the right capsular renal vein in nine patients.Almost all right adrenal veins were visualized using CTRIPA; the detection rate was significantly higher on CTRIPA than on MDCT before TACE.

Chylothorax is a rare but serious complication of thoracic aortic surgery, leading to malnutrition, respiratory insufficiency, and prolonged hospital stay. In this article, we describe the successful treatment of a case of intractable chylothorax by lipiodol lymphography. The patient was a 39-year-old man who underwent descending aortic replacement for a remaining dissected aneurysm after total arch replacement. Chylothorax developed postoperatively. After complete oral intake cessation, total parenteral nutrition, and plasmatic factor XIII administration, lipiodol lymphography detected the chyle leakage location and subsequently decreased pleural effusion. The patient recovered uneventfully and was discharged on postoperative day 30 without any complications.

Objectives To review the imaging findings of renal epithelioid angiomyolipomas. Methods Eight patients treated at two institutions were pathologically diagnosed as having epithelioid angiomyolipoma. All of them underwent computed tomography, and four underwent magnetic resonance imaging. The tumor size, existence of fat, heterogeneity, computed tomography attenuation, degree of enhancement, enhancement pattern and magnetic resonance imaging signal intensity were evaluated. Results Intratumoral fat was not detected in any of the cases. On unenhanced computed tomography, the intratumoral attenuation was hyperattenuating in six of the seven patients who were examined using this modality. On T2-weighted images, the signal intensity of the solid component, cyst wall or septum was low in three of the four cases. Four of the eight cases were heterogeneous solid-type accompanied by hemorrhage, necrosis or hyalinization. One homogeneous solid-type lesion was large in size and was pathologically accompanied by neither hemorrhage nor necrosis. All three multilocular cystic types were pathologically accompanied by massive hemorrhage in the cystic component. One was accompanied by spontaneous perirenal hematoma. Conclusions The radiological appearance of most epithelioid angiomyolipomas has a tendency to be hyperattenuating on unenhanced computed tomography images, with low intensities on T2-weighted images. They can be heterogeneously solid, homogeneously solid or a multilocular cystic lesion with massive hemorrhage.

Objective During cryoablation, cells are destroyed at temperatures less than −20°C. The determining factors for local cancer control in pulmonary cryoablation were assessed using computed tomography (CT), isothermal curves, and histologic findings in pigs. Experimental findings were compared with clinical CT findings and were extrapolated to local cancer control outcomes. Methods Cryoablation was performed with thermal monitoring, and the ablated areas were divided into 3 zones: less than −20°C, −20°C to 0°C, and greater than 0°C and were compared with histologic findings. CT findings with multiplanar reconstruction in 36 nodules were compared with the porcine histologic findings. The relationship between CT findings and 3-year local cancer control was evaluated in 98 nodules. Results The 3 concentric thermal zones correlated with histologic findings as follows: less than −20°C zone, complete tissue destruction (zone D); −20°C to 0°C zone (which surrounded zone D), hemorrhage with air trapping and maintenance of alveolar structures (zone H); and greater than 0°C zone (outermost), edema with sustained alveolar structures (zone E). The CT findings in 36 nodules showed a central solid zone, a surrounding air-containing zone, and an outside solid zone, corresponding to zones D, H, and E, respectively. Local cancer control at 3 years in 80 nodules contained within the central solid zone was significantly greater compared with the 18 nodules that were not (82% vs 33%, P = .0002). Conclusions Pulmonary cryoablation should be performed such that tumors are contained within the central solid zone on CT, which represents the less than −20°C zone.

Purpose To describe the computed tomographic (CT) appearance of lung tumors treated with cryoablation to establish a reliable reference profile. Materials and Methods CT images of 56 patients who underwent follow-up CT for at least 1 year for treatment with cryoablation of 79 tumors from 2003 to 2010 were retrospectively reviewed. Patients had a follow-up CT scan immediately after the procedure; 1 day, 1 week (two-phase dynamic CT), and 1 month later; and then at 3-month intervals. The appearance of ablation zones on CT images was classified into five patterns, and bidimensional diameters and other imaging features were evaluated. Results Seventy-eight percent of ablation zones (62 of 79) showed transformation similar to the following: a consolidation or nodular pattern was seen within the 1-week follow-up, involution and a "stripe" pattern was shown at 1 month or later, and zones later became indistinct. Eighty percent of cases of local progression (eight of 10) arose from the stripe pattern on follow-up CT 6 months or later, after the ablation zones showed a transformation opposite the aforementioned pattern. Ice balls could not always be visualized exactly because of dense peritumoral hemorrhage. Internal and marginal enhancement of the ablation zone within the 3-month follow-up did not show a direct relationship with local progression. In total, cavitation and peritumoral ground-glass opacity were seen in 35% (n = 28) and 85% (n = 66) of ablation zones, respectively. Conclusions The reference profile of CT appearance, which is mandatory for follow-up, has been established. No single indicator of complete ablation was proven throughout this study. Careful long-term follow-up with CT is indispensable.

To evaluate the safety and feasibility of cryoablation for lung tumors as well as the incidence of, and risk factors for, complications.This study included 193 cryoablation sessions for 396 lung tumors in 117 consecutive patients. Univariate and multivariate analyses were performed to assess risk factors for common complications. Changes in laboratory values were analyzed the day after cryoablation.Pneumothorax, pleural effusion, and hemoptysis occurred after 119 (61.7%), 136 (70.5%), and 71 (36.8%) sessions, respectively. Phrenic nerve palsy, frostbite, and empyema occurred after one session each (0.52%). Proximal tumor implantation was observed in one of 471 punctures (0.20%). Of 119 sessions with pneumothorax, 21 (17.6%) required chest tube insertion and two (1.7%) required pleurodesis. Delayed and recurrent pneumothorax occurred in 15 of 193 sessions each (7.8%). A greater number of cryoprobes was a significant (P = .001) predictor of pneumothorax. Male sex (P = .047) and no history of ipsilateral surgery (P = .012) were predictors for the need for chest tube insertion, and no history of ipsilateral surgery (P = .021) was a predictor for delayed/recurrent pneumothorax. Greater number of cryoprobes (P = .001) and no history of ipsilateral surgery (P = .004) were predictors for pleural effusion. Greater number of cryoprobes (P.001) and younger age (P = .034) were predictors for hemoptysis. Mean changes in white blood cell count, platelet count, hemoglobin level, and C-reactive protein level were 2,418/μL ± 2,260 (P.001), -2.0 × 10(4)/μL ± 3.2 (P.001), -0.77 mg/dL ± 0.89 (P.001), and 3.0 mg/dL ± 2.9 (P.001), respectively.Percutaneous cryoablation could be performed minimally invasively with acceptable rates of complications.

Lung cancers in the residual lungs of patients who have undergone pneumonectomies are often unresectable, primarily because of the risks of overt pulmonary function losses. Percutaneous cryoablation of lung tumors is a potentially minimally invasive technique that has recently been used in the treatment of lung cancers and metastatic lung tumors. Here, we present two patients who had previously undergone pneumonectomies, in whom lung cancers in the residual lungs were treated by cryoablation. In both patients, the procedures were performed safely without any complications, such as airway bleeding, hemothoraces, or pneumothoraces. The changes in pulmonary functions after the procedures were minimal: % vital capacity (−1% and −4%), and %FEV 1 (−1% and +10%) in the first and second patients, respectively. The performance statuses were maintained at zero in both patients after cryoablation. In the first patient, local control has been maintained for 4 years. In the second patient, local control was maintained for 2 years until the patient died of distant metastases. This is, to our knowledge, the first reported case of lung cryoablation in residual lungs of patients who have previously undergone pneumonectomies. Application of percutaneous cryoablation may represent a new treatment option for lung tumors in patients who have previously undergone pneumonectomies.

IntroductionPercutaneous cryoablation has been adopted for small, malignant peripheral pulmonary lesions and has yielded favourable results as a less invasive local treatment. A transbronchial approach may reduce the risks of complications, such as pneumothorax and pleural haemorrhage. A fundamental animal experiment on transbronchial cryoablation was performed to examine its immediate safety and effectiveness.MethodsExperimental cryoablation was performed on swine lungs using a rigid cryoprobe, 2.4 mm in diameter. The probe was introduced from the right main bronchus into the distal bronchus via thoracotomy, perforated the end of the conducting bronchus and reached the lung parenchyma. The temperature of the cryoprobe tip reaches approximately −130°C during freezing and approximately 20°C during thawing. After three freeze-thaw cycles, the cryoprobe was removed.ResultsNo significant haemorrhage was bronchoscopically observed in the airways throughout the experiment. The chronological changes and spatial distribution of the temperature of the pulmonary tissue circumferential to the point of the cryoprobe were similar to those seen with transpleural cryoablation and the less than −20°C thermal zone seemed to be established within a radius of at least 12 mm. The central destruction zone of alveolar structures was histologically similar to the thermal zone, while the conducting bronchus structure and the accompanying pulmonary artery were not severely affected.ConclusionExperimental transbronchial cryoablation with a rigid cryoprobe could effectively freeze and destroy peripheral lung alveoli without any significant immediate adverse effects. This may suggest the potential clinical application of transbronchial cryoablation for peripheral malignant lung lesions.

Regarding cryoablation for the malignant lung tumors, multiple trials of the freeze-thaw process have been made, and we considered it necessary to view and analyze the freeze-thaw process as a freeze-thaw sequence. We caused the sequence in a porcine lung in vivo by using an acicular, cylindrical stainless-steel probe as the heat source for the freeze-thaw sequence and cooling to -150 °C with super high-pressure argon gas by causing the Joule-Thomson effect phenomenon at the tip of the probe. In this experiment, we examined the sequence by measuring the temperature and using the isothermal curve and the freezing function. As a result, it was demonstrated that the freezing characteristics considerably differed in the first sequence and the second sequence from those of non-aerated organs such as liver and kidney. In our experiments on porcine lung, thermal properties were considered to change as the bleeding caused by the first thawing infiltrated in the lung parenchyma, and it was confirmed that the frozen area in the second cycle was dramatically enlarged as compared with the first cycle (when a similar sequence is continuously repeated, we say it as cycle). This paper provides these details.

The objective of this study was to validate the usefulness of retroperitoneal hematoma volume as a predictor of perioperative mortality after endovascular aneurysm repair (EVAR) for ruptured abdominal aortic aneurysm (rAAA).We retrospectively reviewed consecutive patients with rAAA who underwent the unified EVAR first protocol between 2012 and 2016 at any one of three participating institutions in Japan and were prospectively registered in a dedicated database. Only patients with preoperative computed tomography scans adequate for three-dimensional volumetric analysis were included. Volumetry was used to measure the retroperitoneal hematoma volume. To adjust for body size differences between patients, the retroperitoneal hematoma volume was divided by the abdominal cavity volume, and the predictive power of this ratio was validated using appropriate statistical methods.Of 114 patients with rAAA managed during the study period, 101 (88.6%) underwent EVAR, 9 (7.9%) underwent open surgical repair, and 4 (3.5%) did not undergo any repair. Finally, 82 of 101 patients treated with EVAR were included in the analysis. Within 30 days after EVAR, the mortality rates for the 82 patients included in the analysis and the 19 excluded patients were 24.4% and 31.6%, respectively, without statistically significant differences (P = .518). The retroperitoneal hematoma volume ratio was 3.59% ± 2.46% and 7.63% ± 3.45% in survivors and nonsurvivors, respectively (P .001). Univariate analysis of other preoperative demographic and anatomic factors revealed that a Glasgow Aneurysm Score85, systolic blood pressure 90 mm Hg, loss of consciousness, and mean minimum right external iliac artery diameter were statistically significant. Receiver operating characteristic curve analysis for the prediction of perioperative mortality revealed that retroperitoneal hematoma volume ratio was the best predictor of perioperative mortality in patients with rAAA of typeIII in the Fitzgerald classification (area under the curve: retroperitoneal hematoma volume ratio, 0.880; Glasgow Aneurysm Score, 0.587; P .001). Based on the Youden index, the optimal cutoff for the retroperitoneal hematoma volume ratio was 6.97%, providing a sensitivity of 0.833 and specificity of 0.860.Our study suggests that retroperitoneal hematoma volume may be a good predictor of perioperative mortality after EVAR for rAAA, especially for patients with Fitzgerald classificationIII and a best cutoff value of 6.97%.

Background Historically, local control of recurrent sarcomas has been limited to radiotherapy when surgical re-resection is not feasible. For metastatic carcinomas to the bone or soft tissue, radiotherapy and some interventional radiology treatment along with other systemic therapies have been widely advocated due to the possibility of disseminated disease. These techniques are effective in alleviating pain and achieving local control for some tumor types, but it has not been effective for prolonged local control of most tumors. Recently, cryoablation has been reported to have satisfactory results in lung and liver carcinoma treatment. In this study, we analyzed the clinical outcome of CT-guided cryoablation for malignant bone and soft tissue tumors to elucidate potential problems associated with this procedure. Methods Since 2011, 11 CT-guided cryoablations in 9 patients were performed for locally recurrent or metastatic bone and soft tissue tumors (7 males and 2 females) at our institute. The patients’ average age was 74.8 years (range 61–86) and the median follow up period was 24.1 months (range 5–48). Histological diagnosis included renal cell carcinoma (n = 4), dedifferentiated liposarcoma (n = 2), myxofibrosarcoma (n = 2), chordoma (n = 1), hepatocellular carcinoma (n = 1), and thyroid carcinoma (n = 1). Cryoablation methods, clinical outcomes, complications, and oncological outcomes were analyzed. Results There were 5 recurrent tumors and 6 metastatic tumors, and all cases had contraindication to either surgery, chemotherapy or radiotherapy. Two and 3 cycles of cryoablation were performed for bone and soft tissue tumors, respectively. The average length of the procedure was 101.1 min (range 63–187), and the average number of probes was 2.4 (range 2–3). Complications included 1 case of urinary retention in a patient with sacral chordoma who underwent prior carbon ion radiotherapy, 1 transient femoral nerve palsy, and 1 minor wound complication. At the final follow up, 4 patients showed no evidence of disease, 2 were alive with disease, and 3 died of disease. Conclusions Reports regarding CT-guided cryoablation for musculoskeletal tumors are rare and the clinical outcomes have not been extensively studied. In our case series, CT-guided cryoablation had analgesic efficacy and there were no cases of local recurrence post procedure during the follow-up period. Although collection of further data regarding use of this technique is necessary, our data suggest that cryoablation is a promising option in medically inoperable musculoskeletal tumors.

To the Editors: Percutaneous cryoablation is considered to be a minimally invasive option for local treatment of cancer [1–3]. Its efficacy is now being documented in many organs, including the prostate, liver, kidney and lung. The goal of ablation procedures is typically complete local tumour control when surgical resection is not indicated, but ablation procedures, such as cryoablation, may also be applicable to the palliative care of cancer patients. Here, we present a case in which percutaneous cryoablation was considered to have contributed to symptom relief in a patient with unresectable, locally advanced, invasive thymoma of the mediastinum. To our knowledge, this is the first report of a needle ablation procedure performed for a mediastinal tumour. A 29-yr-old female presented with intermittent cough that had existed for 2 yrs and had gradually worsened. An abnormal shadow on chest radiography was identified at another clinic and the patient was referred to our hospital (Division of General Thoracic Surgery, Dept of Surgery, School of Medicine, Keio University, Tokyo, Japan) in July 2004. At that time, she complained of frequent cough and dyspnoea. She could not lay flat on her back. Biopsy through parasternal mediastinotomy [4, 5] was performed, from which the pathological diagnosis was thymoma, type B3, according to the World Health Organization classification. The tumour was considered to be …

The present report describes 6 cases of adrenal venous sampling (AVS) in patients who underwent computed tomography (CT) during arteriography because cannulation of right adrenal veins was otherwise difficult. CT was performed during arteriography to obtain information on the location and direction of the right adrenal vein. Two right adrenal veins were visualized in 1 case. The right central adrenal vein was not visualized in 1 case owing to an injury from a previous unsuccessful AVS procedure, but the right renal capsular vein was well visualized. CT during arteriography could contribute to a high AVS success rate.

Radiotherapy has been regularly applied mainly for inoperable patients with non- small cell lung cancer, and various clinical trials have been performed. On the other hand, we have applied percutaneous cryoablation for lung tumors (PCLT) since 2002. In this paper, we describe our experience of PCLT compared to the results of radiation treatment. Three-year local progression-free rates with stereotactic body radiotherapy were 79-92% in stage I A and 30-79% in stage I B. Those with proton radiotherapy were 82-89% in stage I A and 49-62% in stage I B. CTCAE grade ≥3 complications occurred in 3-28% cases, such as radiation pneumonitis. As for PCLT, 1-, 2- and 3-year local progression-free rates were 80.4%, 69.0% and 67.7%, respectively. Pneumothorax, pleural effusion, and hemoptysis occurred after 61.7%, 70.5%, and 36.8% sessions, respectively. Of all cases with pneumothorax, 17.6% required chest tube insertion and 1.7% required pleurodesis. Delayed and recurrent pneumothorax occurred in 7.8% each. CTCAE grade ≥3 complications occurred in 1.5% cases. The biggest advantage of PCLT compared with radiotherapy is the possibility to treat local recurrence at the same site as treated before. In addition, no radiation pneumonitis occurs in PCLT. Moreover, less space or budget is needed when PCLT is newly introduced in a hospital. Although high reliable clinical data is not achieved yet, PCLT is one of the promising methods in local treatment.

To review the imaging findings of renal epithelioid angiomyolipomas.Eight patients treated at two institutions were pathologically diagnosed as having epithelioid angiomyolipoma. All of them underwent computed tomography, and four underwent magnetic resonance imaging. The tumor size, existence of fat, heterogeneity, computed tomography attenuation, degree of enhancement, enhancement pattern and magnetic resonance imaging signal intensity were evaluated.Intratumoral fat was not detected in any of the cases. On unenhanced computed tomography, the intratumoral attenuation was hyperattenuating in six of the seven patients who were examined using this modality. On T2-weighted images, the signal intensity of the solid component, cyst wall or septum was low in three of the four cases. Four of the eight cases were heterogeneous solid-type accompanied by hemorrhage, necrosis or hyalinization. One homogeneous solid-type lesion was large in size and was pathologically accompanied by neither hemorrhage nor necrosis. All three multilocular cystic types were pathologically accompanied by massive hemorrhage in the cystic component. One was accompanied by spontaneous perirenal hematoma.The radiological appearance of most epithelioid angiomyolipomas has a tendency to be hyperattenuating on unenhanced computed tomography images, with low intensities on T2-weighted images. They can be heterogeneously solid, homogeneously solid or a multilocular cystic lesion with massive hemorrhage.

Purpose To evaluate factors predicting local tumor progression after percutaneous cryoablation of lung tumors (PCLT). Materials and Methods Seventy-one consecutive patients with 210 tumors (11 primary and 199 metastatic pulmonary neoplasms; mean maximum diameter, 12.8 mm) were treated with 102 sessions of PCLT. Rates of local tumor progression and technique effectiveness were estimated by Kaplan–Meier method. Multiple variables were evaluated with the log-rank test, followed by uni- and multivariate multilevel analyses to identify independent risk factors, and hazard ratios (HRs) and 95% confidence intervals (CIs) were estimated. All statistical tests were two-sided. Results Median follow-up period was 454 days (range, 79–2,467 d). Local tumor progression occurred in 50 tumors (23.8%). One-, 2-, and 3-year local progression-free rates were 80.4%, 69.0%, and 67.7%, respectively, and technique effectiveness rates were 91.4%, 83.0%, and 83.0%, respectively. Existence of a thick vessel (diameter≥3 mm) no more than 3 mm from the edge of the tumor was assessed as an independent factor (HR, 3.84; 95% CI, 1.59–9.30; P = .003) associated with local progression by multivariate analysis. Conclusions Presence of a vessel at least 3 mm in diameter close to the tumor represents an independent risk factor for local progression after PCLT.

Lung cancers in the residual lungs of patients who have undergone pneumonectomies are often unresectable, primarily because of the risks of overt pulmonary function losses. Percutaneous cryoablation of lung tumors is a potentially minimally invasive technique that has recently been used in the treatment of lung cancers and metastatic lung tumors. Here, we present two patients who had previously undergone pneumonectomies, in whom lung cancers in the residual lungs were treated by cryoablation. In both patients, the procedures were performed safely without any complications, such as airway bleeding, hemothoraces, or pneumothoraces. The changes in pulmonary functions after the procedures were minimal: % vital capacity (-1% and -4%), and %FEV(1) (-1% and +10%) in the first and second patients, respectively. The performance statuses were maintained at zero in both patients after cryoablation. In the first patient, local control has been maintained for 4 years. In the second patient, local control was maintained for 2 years until the patient died of distant metastases. This is, to our knowledge, the first reported case of lung cryoablation in residual lungs of patients who have previously undergone pneumonectomies. Application of percutaneous cryoablation may represent a new treatment option for lung tumors in patients who have previously undergone pneumonectomies.

BackgroundTo evaluate the midterm results of percutaneous cryoablation for medically inoperable stage I non-small cell lung cancer.Methodology/principal findingsBetween January 2004 and June 2010, 160 patients underwent computer tomography guided percutaneous cryoablation for lung tumors at our institution. Of these patients, histologically proven stage I lung cancer patients with more than one year of follow-up, were retrospectively reviewed. All of these patients were considered to be medically inoperable with Charlson comorbidity index of 3 or greater. Follow-up was based primarily on computed tomography. There were 22 patients with 34 tumors who underwent 25 sessions of cryoablation treatment. Complications were pneumothoraces in 7 treatments (28%, chest tube required in one treatment), and pleural effusions in 8 treatments (31%). The observation period ranged from 12-68 months, average 29±19 months, median 23 months. Local tumor progression was observed in one tumor (3%). Mean local tumor progression-free interval was 69±2 months. One patient died of lung cancer progression at 68 months. Two patients died of acute exacerbations of idiopathic pulmonary fibrosis which were not considered to be directly associated with cryoablation, at 12 and 18 months, respectively. The overall 2- and 3-year survivals were 88% and 88%, respectively. Mean overall survival was 62±4 months. Median overall survival was 68 months. The disease-free 2- and 3-year survivals were 78% and 67%, respectively. Mean disease-free survival was 46±6 months. Pulmonary function tests were done in 16 patients (18 treatments) before and after cryoablation. Percentage of predicted vital capacity, and percentage of predicted forced expiratory volume in 1 second, did not differ significantly before and after cryoablation (93±23 versus 90±21, and 70±11 versus 70±12, respectively).Conclusions/significanceAlthough further accumulation of data is necessary regarding efficacy, cryoablation may be a feasible option in medically inoperable stage I lung cancer patients.

The imaging findings of a solitary fibrous tumor of the prostate are presented. A 35-year-old male presented with urinary retention and was found on transrectal ultrasonography to have a hypoechoic tumor of the prostate, measuring 5.5 cm in size. Magnetic resonance imaging on, the tumor showed low signal intensity on T1-weighted images and heterogeneous mixed signal intensity on T2-weighted images. Gadolinium-enhanced dynamic study showed gradual enhancement from the periphery to the center, and the enhancement is sustained. On immunohistochemistry, the spindle cells of the tumor showed positive staining for CD34 and bcl-2. Although the tumor was labeled as a low-grade malignancy on account of a low mitotic index (MIB-1 index) of about 5%, the patient developed local recurrence of the tumor with bladder wall invasion 12 months later.

Extensive iliofemoral occlusive disease can limit the use of endovascular aortic aneurysm repair (EVAR), and the treatment strategy varies depending on severity of the lesion. In cases of mild iliac artery (IA) stenosis, predilation using a balloon catheter before EVAR is relatively common, and for severe IA stenosis, the technique of internal endoconduits has been reported with good results. In contrast, EVAR using an aortouni-iliac stent graft with femorofemoral crossover bypass has traditionally been used for abdominal aortic aneurysm with IA occlusion. However, EVAR using a bifurcated stent graft has some clear advantages over aortouni-iliac stent grafts. In this report, we describe and discuss technical aspects and feasibility of chronically occluded iliac artery recanalization before EVAR to facilitate the use of bifurcated stent grafts in a patient with concomitant complete common to external IA occlusion.

OBJECTIVE: To evaluate the safety and efficacy of cryoablation for metastatic lung tumors from colorectal cancer. METHODS: The procedures were performed on 24 patients (36-82 years of age, with a median age of 62; 17 male patients, 7 female patients) for 55 metastatic tumors in the lung, during 30 sessions. The procedural safety, local progression free interval, and overall survival were assessed by follow-up computed tomographic scanning performed every 3-4 months. RESULTS: The major complications were pneumothorax, 19 sessions (63%), pleural effusion, 21 sessions (70%), transient and self-limiting hemoptysis, 13 sessions (43%) and tract seeding, 1 session (3%). The 1- and 3-year local progression free intervals were 90.8% and 59%, respectively. The 3-years local progression free intervals of tumors ≤15 mm in diameter was 79.8% and that of tumors >15 mm was 28.6% (p = 0.001; log-rank test). The 1- and 3-year overall survival rates were 91% and 59.6%, respectively. CONCLUSION: The results indicated that percutaneous cryoablation is a feasible treatment option. The local progression free interval was satisfactory at least for tumors that were ≤15 mm in diameter.

e17515 Background: Percutaneous cryoablation for lung tumors (PCLT) using high resolution fluoroscopic CT guidance under local anesthesia offers a potential tool for local control of lung tumors, s...

7592 Background: Percutaneous cryoablation using high resolution fluoroscopic CT guidance under local anesthesia offers a potential tool for local control of lung tumors in combination with systemic treatments. In this study, we retrospectively analyzed the safety, and efficacy of percutaneous cryoablation for lung tumors (PCLT). Methods: This study was approved by the institutional review board. From October 2002, PCLT was performed in patients who either did not oncologically fulfill the indications for resection, or refused resection. CT scan was examined every 3 months after PCLT. >20% increase in the treated lesion size was diagnosed as local failure. Survival analysis was done by Kaplan-Meier. Results: There were 147 patients (95 male, 52 female, mean age 60, 20 primary lung cancer, metastases; 29 of lung cancer, 35 of colorectal cancer, 63 of other sites). 251 sessions were done for 462 tumors. Mean tumor diameter was 18.3mm. PCLT was well tolerated in most patients. In 1 case, broncho-thoracic fistula occurred in the treated region which lead to empyema. Other complications were pneumothorax (153 sessions, 61%, chest tube required in 23 sessions), pleural effusion (160 sessions, 64%), and transient hemoptysis (82 sessions, 33%). Overall one- and two-year local control rates were 81.0% and 59.1%, respectively. Overall one- and two-year survival rates were 80.0% and 54.5%, respectively. In the 1–20 mm sized (n=362) vs. over 21mm sized (n=100) lesions, the local control rates at one year were 84% vs. 56% (p=0.0007), and at two years were 63% vs. 35% (p=0.017), respectively. There were no differences in local control between primary and metastatic tumors, carcinomas and sarcomas. Survival of patients whose lesions were limited to 1–20mm (n=89) was prolonged vs. those who had at least one over 21mm lesion (n=58) (p=0.01). However, one, and two-year survival rates did not differ significantly between these groups (one-year; 85.5% vs. 71.7% (p=0.07), two-year; 60.7% vs. 46.5% (p=0.16)). Conclusions: PCLT was minimally invasive and safe. 1–20mm tumors were good candidates. Contribution of PCLT to survival was not clear in this mixed patient population. To improve local control in over 20 mm tumors, we are computer simulating freezing kinetics to optimize the number and the positioning of the probes. No significant financial relationships to disclose.

7186 Background: Cryoablation is reestablishing itself as a potential tool in multi-modality treatment against cancer in organs such as liver, kidney, prostate, and uterus. We found only one clinic...