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Purpose: To evaluate the detection rate of feeding arteries in renal cell carcinoma with automated feeder-detection software and determine the optimal imaging phase for accurate feeder detection with transarterial time-resolved computed tomography angiography., Materials and Methods: The performance of automated feeder-detection software was retrospectively evaluated using transarterial renal time-resolved computed tomography angiography images of 15 renal cell carcinomas (mean size, 22.1 mm); the images were obtained via the renal artery using a hybrid angio-CT system with 320-row computed tomography, across nine phases with 0.5-s intervals over a contrast delay time of 1.0-5.0 s. Automated feeder-detection software was applied to each phase in all tumors (135 image series in total). The feeder-detection rate (i.e., sensitivity) in each phase was evaluated, and the number of false feeders demonstrated by the software was counted for each tumor., Results: A total of 22 feeders were identified. The feeder-detection rate was the highest (95.5% [21/22]) at delay times of 1.5 s and 2.0 s and lower in later phases. At delay times of 1.0 s and 1.5 s, the software demonstrated no or only a few (≤ 3) false feeders in 93.3% (14/15) of the tumors. In later phases, however, many (≥ 4) false feeders were observed in > 50% of tumors., Conclusion: The automated feeder-detection software showed a favorable feeder-detection rate and may be useful in transarterial embolization for renal cell carcinoma. The optimal delay time to avoid the demonstration of false feeders and achieve a high detection accuracy was 1.5 s., Level of Evidence Iv: Case Series., (© 2023. Springer Science+Business Media, LLC, part of Springer Nature and the Cardiovascular and Interventional Radiological Society of Europe (CIRSE).)

Purpose: To retrospectively evaluate long-term efficacy of percutaneous cryoablation for lower limb soft-tissue venous malformations., Materials and Methods: Nine patients (mean age, 36.6 years) with lower limb soft-tissue venous malformations were included. Cryoablation was performed percutaneously using an argon-based system. Adverse events (AE) using the Common Terminology Criteria for AEs version 4.0 were evaluated. The visual analog scale (VAS) scores and lesion volumes measured on magnetic resonance imaging were also evaluated at 12 months and 5-6 years., Results: Technical success (i.e., complete coverage of the lesion by an iceball) was achieved in eight of the nine patients. All patients developed a total of 14 grade 1 or 2 adverse events. The mean (± standard deviation) VAS score was 6.0 (± 1.7) before therapy, whereas it was 0.14 (± 0.27) at 12 months and 0.97 (± 1.3) at 5-6 years (58-78 months). Complete pain relief was obtained in 6 and 5 patients at 12 months and 5-6 years, respectively. The median lesion volume was 2.49 mL before therapy, whereas it was 0.26 mL at 12 months and 0.35 mL at 5-6 years., Conclusion: Percutaneous cryoablation of lower limb soft-tissue venous malformations achieved considerable pain relief and lesion shrinkage for 5-6 years in this small preliminary study., Level of Evidence: Level 4, Case Series., (© 2021. Springer Science+Business Media, LLC, part of Springer Nature and the Cardiovascular and Interventional Radiological Society of Europe (CIRSE).)

Purpose: To verify the hypothesis that depth of the low-intensity band on T1-weighted MR image is useful for distinguishing subchondral insufficiency fracture (SIF) from osteonecrosis of the collapsed femoral head (ON)., Patients and Methods: We reviewed 35 consecutive hips in 35 patients with radiological evidence of subchondral collapse of the femoral head and available MR images and histology between May 2013 and January 2016. Both clinical and radiological appearances were investigated. The ratios of distance from articular surface of the femoral head to the T1 low-intensity band to femoral head diameter (band depth ratio: BDR) on (1) mid-coronal slice of MR images and that on (2) coronal slice of MR images in which the highest BDR was observed, were calculated., Results: The mean age in SIF group was significantly higher than that in ON group (SIF: 68 years, ON: 49 years, P = 0.0017). The rates of history of steroid intake or alcohol consumption in SIF group were significantly lower than those in ON group (P = 0.0022 and P = 0.0408, respectively). The mean BDRs in SIF group were (1) 0.16 and (2) 0.23, which were significantly lower than those in ON group [(1) 0.42 and (2) 0.59] (P < 0.0001 for both). The cut-off BDR values to differentiate SIF from ON were (1) 0.22 and (2) 0.38, respectively., Conclusion: The results of the study suggest that depth of the low-intensity band on T1-weighted MR image is useful for distinguishing SIF from ON in cases with collapsed femoral heads.

Although recent optical coherence tomography (OCT) studies have focused on spotty calcification, whether there were any characteristics in the concomitant existence of calcification and plaque rupture remains unknown. The aim of the present study was to investigate the characteristics of spotty calcification in acute coronary syndrome (ACS) patients with or without plaque rupture, using OCT. This study enrolled 98 consecutive patients with ACS. OCT image acquisitions were performed in the culprit lesions, and patients were divided into the plaque rupture group (n = 38) and the non-rupture group (n = 60). The frequency of spotty calcification (p = 0.006), thin-capped fibroatheroma (p = 0.012), macrophage infiltration (p = 0.022), and the number of spotty calcification per patient (p < 0.001) were significantly higher and the largest arc and the minimum depth of spotty calcification from the luminal surface were significantly smaller in the rupture group. Moreover, in the rupture group, most of the spotty calcifications in the site nearest to the minimum lumen area were observed in the proximal portion of that site, and tended to be located near the plaque rupture. Multivariate analysis revealed that the presence of spotty calcification (OR 3.19, 95 % CI 1.12-9.76, p = 0.030) and age (OR 1.08, 95 % CI 1.02-1.14, p = 0.008) were independent predictive factors for plaque rupture. This study demonstrates the characteristics of spotty calcification in ACS patients with plaque rupture and the positional relationship between spotty calcification and plaque rupture. These detailed observations could impact on treatment strategies for the prevention of ACS.

Introduction: Computed tomography (CT) fluoroscopy-guided renal cryoablation and lung radiofrequency ablation (RFA) have received increasing attention as promising cancer therapies. Although radiation exposure of interventional radiologists during these procedures is an important concern, data on operator exposure are lacking., Materials and Methods: Radiation dose to interventional radiologists during CT fluoroscopy-guided renal cryoablation (n = 20) and lung RFA (n = 20) was measured prospectively in a clinical setting. Effective dose to the operator was calculated from the 1-cm dose equivalent measured on the neck outside the lead apron, and on the left chest inside the lead apron, using electronic dosimeters. Equivalent dose to the operator's finger skin was measured using thermoluminescent dosimeter rings., Results: The mean (median) effective dose to the operator per procedure was 6.05 (4.52) μSv during renal cryoablation and 0.74 (0.55) μSv during lung RFA. The mean (median) equivalent dose to the operator's finger skin per procedure was 2.1 (2.1) mSv during renal cryoablation, and 0.3 (0.3) mSv during lung RFA., Conclusion: Radiation dose to interventional radiologists during renal cryoablation and lung RFA were at an acceptable level, and in line with recommended dose limits for occupational radiation exposure.

Purpose: The aim of the study was to retrospectively evaluate simultaneous multiple hook wire placement outcomes before video-assisted thoracoscopic surgery (VATS)., Materials and Methods: Thirty-eight procedures were performed on 35 patients (13 men and 22 women; mean age, 59.9 years) with 80 lung lesions (mean diameter 7.9 mm) who underwent simultaneous multiple hook wire placements for preoperative localizations. The primary endpoints were technical success, complications, procedure duration, and VATS outcome; secondary endpoints included comparisons between technical success rates, complication rates, and procedure durations of the 238 single-placement procedures performed. Complications were also evaluated., Results: In 35 procedures including 74 lesions, multiple hook wire placements were technically successful; in the remaining three procedures, the second target placement was aborted because of massive pneumothorax after the first placement. Although complications occurred in 34 procedures, no grade 3 or above adverse event was observed. The mean procedure duration was 36.4 ± 11.8 min. Three hook wires dislodged during patient transport to the surgical suite. Seventy-four successfully marked lesions were resected. Six lesions without hook wires were successfully resected after detection by palpation with an additional mini-thoracotomy or using subtle pleural changes as a guide. The complication rates and procedure durations of multiple-placement procedures were significantly higher (P = 0.04) and longer (P < 0.001) than those in the single-placement group, respectively, while the technical success rate was not significantly different (P = 0.051)., Conclusions: Simultaneous multiple hook wire placements before VATS were clinically feasible, but increased the complication rate and lengthened the procedure time.

Purpose: We retrospectively evaluated the outcomes of lung cancer patients presenting with ground-glass opacity (GGO) who received radiofrequency ablation (RFA)., Methods: Sixteen patients (5 men and 11 women; mean age, 72.6 years) with 17 lung cancer lesions showing GGO (mean long axis diameter, 1.6 cm) underwent a total of 20 percutaneous computed tomography (CT) fluoroscopy-guided RFA sessions, including three repeated sessions for local progression. Lung cancer with GGO was defined as a histologically confirmed malignant pulmonary lesion with a GGO component accounting for >50 % of the lesion on high-resolution CT. Procedure outcomes were evaluated., Results: There were no major complications. Pneumothorax occurred in 15 of 20 treatment sessions: 14 were asymptomatic, and 1 required chest tube placement but resolved satisfactorily within 48 h. Minor pulmonary hemorrhage occurred in two and mild pneumonitis in one. The median tumor follow-up period was 61.5 (range 6.1-96.6) months. The effectiveness rates of the primary and secondary techniques were 100 and 100 % at 1 year, 93.3 and 100 % at 2 years, and 78.3 and 92.3 % at 3 years, respectively. The median patient follow-up period was 65.6 (range 6.1-96.6) months. One patient died owing to recurrent other cancer 11.7 months after RFA, whereas the other 15 remained alive. Overall survival and disease-specific survival rates were 93.3 and 100 % at 1 year and 93.3 and 100 % at 5 years, respectively., Conclusions: RFA for lung cancer with GGO was safe and effective, and resulted in promising survival rates.

Purpose: We retrospectively evaluated the results of the transfissural route for preoperative localization with a short hook wire and suture system for video-assisted thoracoscopic surgery (VATS)., Methods: Eleven patients with 11 tumors underwent CT-guided transfissural placement of a hook wire before VATS. This route was selected for all patients, because the distance between the tumor and interlobar fissure was much shorter than the required distance traversed using the conventional approach. Complications were evaluated using the National Cancer Institute Common Terminology Criteria for Adverse Events Version 4.0., Results: The hook wire was successfully placed using the transfissural route in all but one case. Of these ten successful placements, two tumors needed a second puncture for optimal placement, because the CT scan showed that the first hook wire was not properly placed in the lung. In one patient, we did not attempt replacement after the first placement was incorrect. In ten successful procedures, the mean distance traversed in the parenchyma of the unaffected lung lobe was 27.9 mm. The distance between the pleura and placed hook wire was significantly shorter than the estimated distance between the pleura and hook wire using the conventional route (mean 16.3 vs. 40.9 mm; P = 0.0002). Grade 1 adverse events occurred (11 pneumothoraxes and 4 pulmonary hemorrhages). No grade 2 or higher adverse event was observed., Conclusions: The transfissural route used for preoperative localization before VATS is useful for selected patients because this route may allow for more limited lung parenchyma resection.

Purpose: To determine risk factors for systemic air embolism by percutaneous computed tomography (CT)-guided lung biopsy., Methods: This case-control study used data from 2216 percutaneous lung biopsy procedures performed over 11 years at 12 institutions in Japan. Systemic air embolism was identified by retrospective review of CT images obtained during and immediately after the procedures. To fulfill our objective, multiple variables were compared between cases and controls with univariate analyses by using Student's t test and Fisher's exact test for numerical and categorical values, respectively. Multivariate logistic regression analysis was then performed using selected variables., Results: Ten cases of systemic air embolism and 2,206 controls were identified. Univariate analyses showed that the lesions in the lower lobe (P = 0.025) and occurrence of parenchymal hemorrhage (P = 0.019) were significant risk factors. Multivariate analysis showed that the use of a larger biopsy needle was a significant risk factor (P = 0.014)., Conclusion: Parenchymal hemorrhage during the procedure, lesions in the lower lobe, and the use of larger biopsy needles may be risk factors for systemic air embolism by percutaneous CT-guided lung biopsy. Our findings may provide clues toward minimizing the risk of this complication.

A low ratio of eicosapentaenoic acid to arachidonic acid (EPA/AA) has been demonstrated to be associated with a higher risk of cardiovascular events. Optical coherence tomography (OCT) is useful for the assessment of coronary plaque vulnerability. The purpose of this study was to evaluate the association between EPA/AA ratio and coronary plaque vulnerability. This study involved 58 patients with stable angina pectoris undergoing percutaneous coronary intervention. OCT image acquisition was performed before the procedure in the culprit lesions. We assessed lipid-rich plaque length and arc, fibrous cap thickness, frequency of thin-cap fibroatheroma (TCFA), thrombus, ruptured plaque, macrophage infiltration, and microvessels using OCT. Patients were divided into two groups according to the median value of serum EPA/AA ratio: a low-EPA/AA group (n = 29, EPA/AA ratio <0.36) and a high-EPA/AA group (n = 29, EPA/AA ratio ≥0.36). In qualitative analyses, TCFA (35.4 vs 6.9 %, P = 0.0095), macrophage infiltration (48.3 vs 13.8 %, P = 0.0045), and microvessels (44.8 vs 10.3 %, P = 0.0033) were more frequently observed in the low-EPA/AA group. In quantitative analyses, the low-EPA/AA group had wider maximum lipid arc (114.0 ± 94.8° vs 56.4 ± 66.0°, P = 0.0097), longer lipid length (4.8 ± 4.5 vs 1.6 ± 2.6 mm, P = 0.0037), and thinner fibrous cap (69.3 ± 28.3 vs 113.3 ± 46.6 μm, P = 0.005) compared with the high-EPA/AA group. EPA/AA ratio was positively correlated with fibrous cap thickness (r = 0.46, P = 0.007). In a multivariate model, an EPA/AA ratio <0.36 was associated with the presence of TCFA (odds ratio 6.41, 95 % confidence interval 1.11-61.91, P = 0.0371). In our detailed OCT analysis, lower EPA/AA ratio was associated with higher vulnerability of coronary plaques to rupture.

Although obesity and chest-wall thickness influence the Sokolow-Lyon electrocardiographic (ECG) voltage criteria and strain pattern, these factors have not been taken into account in previous studies that evaluate the relationship between the ECG criteria and anatomic left ventricular hypertrophy (LVH). The introduction of multislice computed tomography (MSCT) has enabled assessment of not only coronary artery stenoses but also left ventricular volume and mass, left atrial volume, and chest-wall thickness. We hypothesized that evaluating the relation between the ECG voltage criteria or strain pattern and the aforementioned factors using MSCT would be highly valuable. The study population consisted of 93 patients who required MSCT angiography. The Sokolow-Lyon voltage and strain patterns were determined to detect anatomic LVH, which was defined as increased left ventricular mass. The Sokolow-Lyon voltage criteria, as an indicator of anatomic LVH, had a sensitivity of 57 %, specificity of 67 %, positive predictive value of 36 %, and negative predictive value of 82 %. By contrast, the strain pattern had a sensitivity of 65 %, specificity of 87 %, positive predictive value of 63 %, and negative predictive value of 88 %. Multivariate analysis revealed that the strain pattern was associated with the presence of anatomic LVH, whereas the Sokolow-Lyon voltage was not. This MSCT study demonstrated that even after removing the effects of various factors, the strain pattern remained associated with the presence of anatomic LVH, in contrast to the Sokolow-Lyon voltage.

Several coronary angiographic studies have reported that enlarged and tortuous epicardial coronary arteries are characteristic of patients with left ventricular concentric hypertrophy (LVCH). Recently, we showed that small volumes opacified by contrast medium can be accurately measured by 64-multislice computed tomography (MSCT) and that there is a direct relationship between the coronary artery volume and left ventricular (LV) mass. However, the relationship of coronary artery volume with LV mass in patients with dilated cardiomyopathy (DCM) is unknown. The present study was designed to investigate this issue. Thirteen patients with DCM and 18 patients with LVCH who underwent MSCT angiography were included in this analysis. The coronary arteries were segmented on a workstation, and the appropriate window settings obtained from the results of the phantom experiments were applied to the volume-rendered images to calculate the total coronary artery volume (right and left coronary arteries). The absolute coronary lengths and volumes in patients with LVCH and DCM were greater than those in controls. The coronary artery volumes adjusted for LV mass in patients with DCM were found to be smaller than those in patients with LVCH or in controls, and these values did not differ between patients with LVCH and controls (DCM 4.1 ± 0.9, LVCH 5.4 ± 1.4, controls 5.5 ± 2.3 ml/100 g of LV mass, P < 0.005; DCM vs LVCH, P < 0.01; and DCM vs control, P < 0.0005). This study showed that the increase in the coronary artery volume in patients with LVCH matched the increase in LV mass, but a decreased coronary volume with regard to LV mass was characteristic of patients with DCM.

Purpose: ADVANCE Medial-Pivot (MP) (Wright Medical Technology, Arlington, TN, USA) total knee arthroplasty (TKA) was developed to replicate normal tibiofemoral knee joint kinematics, allowing medial-pivot knee motion. The design concept of the prosthesis is unique; therefore, the influence on the patellofemoral knee joint remains unclear at present. The purpose of this study was to determine the in vivo patellofemoral kinematics with ADVANCE MP TKA and compare them with the pre-operative conditions., Methods: ADVANCE MP TKA was performed in ten subjects with osteoarthritis (OA). At before and one month after surgery, lateral radiographs with weight-bearing at maximum extension, 30, 60 and 90° were taken, and patella flexion angle (PF), tibiopatellar angle (TP) and estimated patellofemoral contact point (PC) were evaluated, according to a previously reported method., Results: In PF and TP, there was no statistically significant change between pre-operative and postoperative values. Pre-operative PC reached its peak at 90°; however, its peak was at 60° at one month after surgery. Postoperative PC at maximum extension was significantly higher compared to before surgery., Conclusions: The results in this study indicated that ADVANCE MP TKA changed patellofemoral joint kinematics compared to before surgery. Early postoperative evaluation is the limitation of this study; however, we consider that the results in this study might be one of the keys to resolving the kinematic features of this prosthesis, helping clinicians to comprehend this prosthesis.

Purpose: The purpose of this study was to evaluate altered pulmonary function retrospectively after RFA., Methods: This retrospective study comprised 41 ablation sessions for 39 patients (22 men and 17 women; mean age, 64.8 years). Vital capacity (VC) and forced expiratory volume in 1 s (FEV(1)) at 1 and 3 months after RFA were compared with the baseline (i.e., values before RFA). To evaluate the factors that influenced impaired pulmonary function, univariate analysis was performed by using multiple variables. If two or more variables were indicated as statistically significant by univariate analysis, these variables were subjected to multivariate analysis to identify independent factors., Results: The mean VC and FEV(1) before RFA and 1 and 3 months after RFA were 3.04 and 2.24 l, 2.79 and 2.11 l, and 2.85 and 2.13 l, respectively. The values at 1 and 3 months were significantly lower than the baseline. Severe pleuritis after RFA was identified as the independent factor influencing impaired VC at 1 month (P = 0.003). For impaired FEV(1) at 1 month, only severe pleuritis (P = 0.01) was statistically significant by univariate analysis. At 3 months, severe pleuritis (VC, P = 0.019; FEV(1), P = 0.003) and an ablated parenchymal volume ≥20 cm(3) (VC, P = 0.047; FEV(1), P = 0.038) were independent factors for impaired VC and FEV(1)., Conclusions: Pulmonary function decreased after RFA. RFA-induced severe pleuritis and ablation of a large volume of marginal parenchyma were associated with impaired pulmonary function.

Purpose: This is a randomised controlled trial to examine whether intra-articular injection of tranexamic acid (TXA) decreases blood loss, as well as reducing leg swelling after total knee arthroplasty (TKA)., Methods: We performed 100 TKA in osteoarthritis patients. At closure, a total of 2,000 mg/20 ml TXA was injected into the knee joint through a closed suction drain (TXA group). For the control group, the same volume of physiological saline was injected. The pre-operative condition of the patients, post-operative haemoglobin (Hb) levels, discharge volumes from drain, D-dimer and needs for transfusion were compared between these two groups. Furthermore, leg diameters (thigh, suprapatellar portion and calf girth) were measured pre- and post-operatively to investigate whether TXA has an influence on leg swelling after surgery., Results: The results revealed that post-operative decrease in Hb level was significantly reduced in the TXA group. Furthermore, knee joint swelling after operation was significantly suppressed in the TXA group compared to the control group., Conclusions: The results revealed intra-articular administration of TXA decreased not only blood loss, but also knee joint swelling after TKA.

Objective: The purpose of this study was to evaluate retrospectively the safety and effectiveness of the computed tomography (CT) fluoroscopy-guided placement of iliosacral screws in patients with unstable posterior pelvic fractures., Materials and Methods: Six patients (four women and two men; mean age 55.8 years; range 35-77 years) with unstable posterior pelvic fractures underwent iliosacral screw placement under CT fluoroscopy guidance between November 2007 and August 2008. Unstable pelvic ring injury (AO types B and C) was the indication for this procedure., Results: In all the six patients except one, CT fluoroscopy-guided placement had been technically successful. In one patient, a second screw had been inserted, with a tilt to the caudal site, and slightly advanced into the extrasacral body; afterward, it could be exchanged safely for a shorter screw. Five patients and one patient underwent placement of two screws and one screw, respectively. The mean duration of the procedure was 15.0 min (range 9-30 min) per screw; the duration was 12.3 min and 18.2 min for the first and second screws, respectively. No complications requiring treatment occurred during or after the procedure. The mean clinical and radiologic follow-up period was 14 months (range 6-21 months). All pelvic injuries had healed satisfactorily, without complication, and all patients are now doing well clinically and can walk., Conclusion: CT fluoroscopy-guided placement of iliosacral screws is a safe and effective treatment in patients with unstable posterior pelvic fractures.

The purpose of this study was to investigate the relationship between pleural temperature and pneumothorax or pleural effusion after radiofrequency (RF) ablation of lung tumors. The pleural temperature was measured immediately outside the lung surface nearest to the tumor with a fiber-type thermocouple during 25 ablation procedures for 34 tumors in 22 patients. The procedures were divided into two groups depending on the highest pleural temperature: P-group I and P-group II, with highest pleural temperatures of <40 degrees C and >/=40 degrees C, respectively. The incidence of pneumothorax or pleural effusion was compared between the groups. Multiple variables were compared between the groups to determine the factors that affect the pleural temperature. The overall incidence of pneumothorax and pleural effusion was 56% (14/25) and 20% (5/25), respectively. Temperature data in five ablation procedures were excluded from the analyses because these were affected by the pneumothorax. P-group I and P-group II comprised 10 procedures and 10 procedures, respectively. The incidence of pleural effusion was significantly higher in P-group II (4/10) than in P-group I (0/10) (p = 0.043). However, the incidence of pneumothorax did not differ significantly (p = 0.50) between P-group I (4/10) and P-group II (5/10). Factors significantly affecting the pleural temperature were distance between the electrode and the pleura (p < 0.001) and length of the lung parenchyma between the electrode and the pleura (p < 0.001). We conclude that higher pleural temperature appeared to be associated with the occurrence of pleural effusion and not with that of pneumothorax.

Purpose: We retrospectively evaluated the safety and efficacy of preoperative initial hepatic arterial infusion chemotherapy (HAIC) through a port-catheter system in patients with liver dysfunction due to synchronous and unresectable liver metastases. The aim of HAIC was to improve patients' clinical condition for later surgical removal of primary colorectal cancer., Methods: Port-catheter systems were placed radiologically in 21 patients (mean age 58.6 +/- 8.1 years) with liver dysfunction due to synchronous liver metastases from colorectal cancer. Initial HAIC of 1,000 mg/m(2) 5-fluorouracil was administered weekly as a 5 hr continuous infusion through this system. Surgical removal of the primary lesion was planned after HAIC improved the liver function., Results: Port-catheter system placement was successful in all patients without severe complications. Patients were followed up for a median of 309 days (range 51-998 days). After starting HAIC, no severe adverse events that caused drug loss and treatment postponement or suspension were observed in any of the patients. HAIC was performed a mean of 4.5 +/- 3.0 times and the liver function improved in all patients. Curative (n = 18) or palliative (n = 1) surgical removal of the primary lesion was performed. The remaining 2 patients died because extrahepatic metastases developed and their performance status worsened; thus, surgery could not be performed. The median survival times of all patients and the operated patients were 309 and 386 days, respectively., Conclusion: Initial HAIC administration is a safe and efficacious method for improving liver function prior to operative resection of primary colorectal cancer in patients with liver dysfunction due to synchronous and unresectable liver metastases.

A 66-year-old man underwent CT-guided drainage catheter placement within a pelvic abscess with a diameter of 46 mm. We performed the drainage by a transsacral approach because it was considered the safest and most feasible approach. An 8G bone marrow biopsy needle was used to penetrate the sacrum to create a path for subsequent drainage catheter insertion. After withdrawal of the biopsy needle, a 6 Fr catheter was advanced into the abscess cavity through the path using the Seldinger technique. Except for bearable pain, no procedure-related complications occurred. Twenty-nine days after the placement, the catheter was withdrawn safely and the abscess cavity had shrunk remarkably.

We performed percutaneously radiofrequency (RF) ablation of 5 renal cell carcinomas (mean diameter 26 +/- 15 mm) with computed-tomography (CT) fluoroscopic guidance using the transhepatic route. The RF electrode was successfully advanced into all tumors. RF ablation caused one minor complication (small asymptomatic perirenal hematoma); no major complications occurred. The follow-up contrast-enhanced CT images showed no local tumor progression of any tumors in a median period of 10 months (range 3-14 months). In conclusion, it seems that this transhepatic approach is safe and can be an alternative method for electrode insertion during RF ablation of selected renal tumors.