Evaluating the Effectiveness and Clinical Outcomes of Endovascular Aneurysm Repair-First Approach for Ruptured Abdominal Aortic Aneurysm in Japan.

PURPOSE: To verify the validity of an endovascular aneurysm repair (EVAR)-first strategy for treating patients with ruptured abdominal aortic aneurysm (rAAA) in Japan. MATERIALS AND METHODS: This study was conducted on 2 groups of patients with rAAA who underwent surgical treatment at 3 hospitals in the Kanagawa Prefecture, Japan, between January 2007 and September 2016. The open surgical treatment group comprised patients with rAAA who underwent open surgical treatment before January 2012; their data were retrospectively collected from their medical records. The EVAR-first strategy group comprised patients with rAAA who underwent treatment based on the Shonan rAAA protocol (SRAP; the standard protocol-based EVAR-first strategy) in or after February 2012; their data were collected prospectively. The short- and long-term treatment outcomes of both groups were compared. In addition, a risk score-based sensitivity analysis (one-to-one matching) was conducted on both groups using a caliper with 0.2 standard deviations of the score. RESULTS: Of the 163 patients with rAAA, the open surgical and EVAR-first strategy groups comprised 53 and 110 patients, respectively (EVAR: 91.8%, open repair: 8.2%). The 30-day postoperative mortality rate differed significantly, being 42% for the open surgery group and 25% for the EVAR-first strategy group (odds ratio: 0.44, 95% confidence interval: 0.20-0.97). The postoperative survival rates at 6 months, 1 year, and 3 years were 66%, 48%, and 58% for the EVAR-first group, respectively, and 51%, 66%, and 48% for the open surgery group, respectively (p=0.072). In a matched cohort analysis (n=50), the 30-day postoperative mortality rate was 22% for the EVAR-first group and 44% for the open surgery group (odds ratio: 0.35, 95% confidence interval: 0.14-0.90). The postoperative survival rates at 6 months, 1 year, and 3 years were 76%, 76%, and 63% for the EVAR-first group, respectively, and 48%, 45%, and 45% for the open surgery group, respectively (p=0.003). CONCLUSION: The SRAP-based EVAR-first strategy for rAAA yielded significantly better treatment outcomes than the open surgical strategy. These findings suggest that EVAR should be considered the primary treatment option for rAAA, given its potential to reduce early mortality rates. CLINICAL IMPACT: Multicenter retrospective analysis of prospectively collected registry data was done to compare treatment outcomes of two groups of ruptured abdominal aortic aneurysm patients open surgery and endovascular-aneurysm-repair (EVAR)-first strategy (Shonan ruptured abdominal aortic aneurysm protocol). EVAR-first group showed better outcomes: lower 30-day mortality (25% vs. 42%), higher survival rates at 6 months, 1 year, and 3 years. Take home Message: The study supports the use of the EVAR-first strategy with the Shonan Protocol for treating ruptured abdominal aortic aneurysms in Japan, showing improved outcomes, reduced 30-day postoperative mortality, and better long-term survival rates compared to the conventional approach.

Successful Endovascular Repair of an Aortobronchial Fistula due to Takayasu Arteritis.

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.

The Utility of Indigo Carmine and Lipiodol Mixture for Preoperative Pulmonary Nodule Localization before Video-Assisted Thoracic Surgery.

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.

Retroperitoneal hematoma volume is a good predictor of perioperative mortality after endovascular aneurysm repair for ruptured abdominal aortic aneurysm.

OBJECTIVE: 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). METHODS: 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. RESULTS: 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 Score >85, 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 type >III 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. CONCLUSIONS: Our study suggests that retroperitoneal hematoma volume may be a good predictor of perioperative mortality after EVAR for rAAA, especially for patients with Fitzgerald classification >III and a best cutoff value of 6.97%.

CT guided cryoablation for locally recurrent or metastatic bone and soft tissue tumor: initial experience.

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.

Lymphatic Intervention for Various Types of Lymphorrhea: Access and Treatment.

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.

CT during Arteriography to Visualize the Right Adrenal Vein for Adrenal Venous Sampling.

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.

Endovascular repair of abdominal aortic aneurysm using bifurcated stent-graft in a patient with complete occlusion from the common to the external iliac artery.

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.

[Results of percutaneous cryoablation for malignant lung tumors compared with radiotherapy].

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.

Factors affecting local progression after percutaneous cryoablation of lung tumors.

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.

Epithelioid angiomyolipoma of the kidney: radiological imaging.

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.

Computed Tomography-guided Drainage with Modified Trocar Technique Using a Drainaway Drainage Kit.

Purpose: Image-guided percutaneous drainage for abscesses is known as a safe and effective treatment. The computed tomography-guided percutaneous drainage kit Drainaway (SB Kawasumi Co., Ltd.), developed on the basis of a modified trocar method, has made it possible to complete the procedure only under computed tomography guidance without radiographic fluoroscopy. This study investigated the feasibility and safety of Drainaway for abscess drainage. Material and Methods: In this retrospective observational study, 28 procedures in 27 patients (18 men and 9 women; age 67.0 ± 12.3 years) who underwent computed tomography-guided drainage using Drainaway between March and December 2021 at seven affiliated hospitals were analyzed. Patients with symptomatic, puncturable on computed tomography and refractory abscesses were included. Technical success (successful drainage with computed tomography alone), primary clinical success (successful drainage with Drainaway alone), secondary clinical success (avoidance of surgery), and complications were evaluated. Results: The sites of the abscesses were the intraperitoneal, retroperitoneal, and thoracic cavities in 19, 5, and 2 patients, respectively, and subcutaneous tissue in 1 patient. The mean size of the abscesses was 7.1 ± 3.4 cm. The technical success rate was 96.4%; the ligament of the puncture route could not be penetrated in one case. The primary clinical success rate was 77.8%, whereas the secondary clinical success rate of catheter upsizing or replacement was 96.3%. Complications included one case of biliary pleurisy that required drainage. Conclusions: Drainaway is a useful device that allows abscess drainage using only computed tomography guidance without radiographic fluoroscopy.

Computed tomographic appearance of lung tumors treated with percutaneous cryoablation.

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.

Percutaneous cryoablation of lung tumors: feasibility and safety.

PURPOSE: To evaluate the safety and feasibility of cryoablation for lung tumors as well as the incidence of, and risk factors for, complications. MATERIALS AND METHODS: 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. RESULTS: 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. CONCLUSIONS: Percutaneous cryoablation could be performed minimally invasively with acceptable rates of complications.

Actual incidence of cerebral infarction after thoracic endovascular aortic repair: a magnetic resonance imaging study.

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 < 0.001). The following risk factors were identified for asymptomatic CI: aortic arch debranching (P < 0.001), left subclavian artery occlusion (P = 0.001) and grade 4/5 aortic arch atheroma (P = 0.048). 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.

Feasibility and safety of percutaneous cryoablation under local anesthesia for the treatment of malignant lung tumors: a retrospective cohort study.

Background: 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. Methods: 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. Results: 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). Conclusions: 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.

Portal Vein Damage after DEB-TACE and Lipiodol-TACE: Based on Evaluation by Computed Tomography during Arterial Portography.

Purpose: 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. Material and Methods: 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. Results: 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]; p < 0.001; 41.7% [10/24] vs. 12% [3/25]; p = 0.019). Drug-eluting beads transarterial chemoembolization and selectivity of transarterial chemoembolization (selective [

On freeze-thaw sequence of vital organ of assuming the cryoablation for malignant lung tumors by using cryoprobe as heat source.

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.

Comparison of radiopaque dye materials for localization of pulmonary nodules before video-assisted thoracic surgery.

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.