Takuya Hashizume

Usefulness of CT-guided hookwire marking before video-assisted thoracoscopic surgery for small pulmonary lesions.

The aim of this study was to evaluate the technical and clinical efficacy and safety of CT‐guided hookwire marking before video‐assisted thoracoscopic surgery (VATS) for small pulmonary lesions.

Percutaneous fiducial marker placement under CT fluoroscopic guidance for stereotactic body radiotherapy of the lung: an initial experience

The aim of this study is to describe our initial experience with the VISICOIL, which is the first percutaneous fiducial marker approved for stereotactic body radiotherapy in Japan, and to evaluate its technical and clinical efficacy, and safety. Eight patients underwent this procedure under CT fluoroscopic guidance. One patient had two tumors, so the total number of procedures was nine. We evaluated the technical and clinical success rates of the procedure and the frequencies of complications. Technical success was defined as when the fiducial marker could be placed at the target site, and clinical success was defined as when stereotactic body radiotherapy could be performed without the marker dropping out of position. The technical success rate was 78% (7/9). In one of the two failed cases, we aimed to place the marker inside the tumor, but misplaced it beside the tumor. In the other failed case, we successfully placed the marker beside the tumor as planned; however, the marker migrated to near the pleura after the patient stopped holding their breath. None of the markers dropped out of place, so the clinical success rate was 100% (9/9). The complication rates were as follows: pneumothorax: 56% (5/9), pneumothorax necessitating chest tube placement: 44% (4/9), focal intrapulmonary hemorrhaging: 67% (6/9), hemoptysis: 11% (1/9), mild hemothorax 11% (1/9), air embolism 0% (0/9), and death 0% (0/9). In conclusion, this new percutaneous fiducial marker appears to be useful for stereotactic body radiotherapy due to its good stability.

Reperfusion Rates of Pulmonary Arteriovenous Malformations after Coil Embolization: Evaluation with Time-Resolved MR Angiography or Pulmonary Angiography

PURPOSE To assess reperfusion rates after coil embolization for pulmonary arteriovenous malformations (PAVMs) using time-resolved magnetic resonance (MR) angiography or pulmonary angiography. MATERIALS AND METHODS Patients with PAVMs who underwent embolization and met the following inclusion criteria were included: (a) embolization was performed using bare or fibered platinum microcoils or both, (b) the complete cessation of flow was confirmed by digital subtraction angiography, and (c) follow-up examinations were conducted with time-resolved MR angiography or pulmonary angiography. Coil embolization was performed in 16 patients with 24 untreated or reperfused PAVMs. Sac embolization was performed for 12 untreated PAVMs. Feeding artery embolization was performed as primary embolization in each of the 12 reperfused PAVMs. Five PAVMs were treated 2 to 4 times because of reperfusion. The study included 32 coil embolizations. Follow-up images were reviewed, and reperfusion rates were assessed. The relationships between reperfusion and the location of PAVM, size of PAVM (feeding artery and venous sac), coils (number and total length), timing of embolization (primary or repeat embolization), and types of coils used (with or without fibered coils) were examined. RESULTS Reperfusion rates at 3, 6, 12, and 24 months were 8%, 27%, 36%, and 49%, respectively, for the 12 untreated PAVMs (primary embolization) and 50%, 50%, 92%, and 100%, respectively, for the 12 reperfused PAVMs (repeat embolization) (P = .0062). No significant differences were observed in the other parameters measured. CONCLUSIONS When evaluated with time-resolved MR angiography or pulmonary angiography, reperfusion rates after coil embolization for PAVM were considerably high, particularly with repeat embolization.

Feasibility of time-resolved MR angiography for detecting recanalization of pulmonary arteriovenous malformations treated with embolization with platinum coils.

PURPOSE To assess the feasibility of time-resolved magnetic resonance (MR) angiography as a follow-up method after embolization for pulmonary arteriovenous malformations (PAVMs). MATERIALS AND METHODS Evaluation of 28 PAVMs in 10 patients previously treated with embolization with platinum coils was performed. The mean observation period after embolization was 49 months. All patients underwent unenhanced chest computed tomography (CT) and time-resolved MR angiography followed by transcatheter digital subtraction angiography within 5 weeks for a definite diagnosis. Two radiologists reviewed the CT and time-resolved MR angiography findings using a blinded method. On CT, the draining veins of the PAVMs were measured before and after embolization, and shrinkage rates were calculated. On time-resolved MR angiography, recanalization was diagnosed when the draining vein or aneurysmal sac or both were enhanced in the pulmonary arterial phase. Correlations between recanalization, the shrinkage rate of the draining vein, and the diagnostic accuracies of CT and time-resolved MR angiography were assessed and compared with digital subtraction angiography. RESULTS Five lesions could not be measured on CT because of metallic artifacts. The mean shrinkage rates of the draining vein for recanalized and occluded PAVMs were 23% ± 19 (SD) for recanalized PAVMs and 47% ± 21 for occluded PAVMs (P = .001). The sensitivity and specificity were 93% and 53%, respectively, when the shrinkage rate threshold was set to 50%. On time-resolved MR angiography, the sensitivity and specificity were 93% and 100%, respectively, for Reader 1 and 100% and 93%, respectively, for Reader 2. The κ coefficient was 0.86. CONCLUSIONS Time-resolved MR angiography appears to be a feasible method for PAVM follow-up examinations and to provide a more accurate diagnosis of recanalization compared with unenhanced CT.

Triaxial System for Embolization of Type II Endoleak After Endovascular Aneurysm Repair

Purpose To demonstrate the utility of a triaxial catheter system for embolization of type II endoleak after endovascular aneurysm repair. Technique The technique is illustrated in 2 patients with sac enlargement owing to persistent type II endoleak of lumbar artery origin. In both cases, the access to the iliolumbar and lumbar arteries was very long and tortuous. For selective catheterization in this situation, a 4-F catheter is advanced through the access site, and 2.7-F microcatheter is inserted into the iliolumbar artery, followed by a 1.9-F untapered microcatheter. The latter is advanced along with a 0.014-inch microguidewire into the feeding artery. Supported by the 2.7-F microcatheter, the no-taper microcatheter is then navigated through the endoleak to the draining vessel for embolization. Conclusion This simple-to-use triaxial catheter system seems well suited for superselective embolization of type II endoleaks with very long and tortuous access routes. If glue is used and multiple doses are required, access to the feeding artery is not lost if the smaller microcatheter has to be replaced.

Triaxial coil embolization using Guglielmi detachable coils with the voltage-dependent coil-detaching technique

Background A triple co-axial (triaxial) system, consisting of a 1.9-Fr non-tapered microcatheter with one marker, a 2.7-Fr microcatheter, and a 4-Fr catheter, has been recently developed, and can be used in coil embolizations using 0.010-inch Guglielmi detachable coils (GDCs) with a voltage-dependent coil-detaching technique. Purpose To describe this new technique and evaluate its technical feasibility and clinical efficacy. Material and Methods Twenty patients underwent this procedure. Diseases were gastrointestinal bleeding in five patients, traumatic bleeding in three patients, and other diseases in 12 patients. The technical success rate, clinical success rate, and complications of this procedure were evaluated. Technical success was defined as the successful delivery and detachment of a GDC, and clinical success was defined as the immediate postembolic complete cessation of blood flow confirmed by digital subtraction angiography. Results A total of 140 GDCs were used and 20 arteries were embolized. The technical success rate was 94% (131/140) and clinical success rate was 95% (19/20). No major complications were reported. Conclusion The triaxial system in coil embolization using a GDC by monitoring the voltage for coil-detaching appeared to be safe and effective.

Triaxial transarterial embolization for lower gastrointestinal bleeding: A retrospective case series

Abstract Objective: Superselective transcatheter arterial embolization (TAE) is important for lower gastrointestinal (GI) bleeding. A new 1.9-Fr. no-taper microcatheter has recently become available and can be inserted into a 2.7-Fr. microcatheter. We assessed the applicability of this new triple co-axial (triaxial) system to TAE for lower GI bleeding. Material and methods: Five patients with lower GI bleeding underwent TAE with the triaxial system. The approach was via the femoral artery with a 4-Fr. sheath in all cases. The 4-Fr. catheter and triaxial system were inserted into the artery in which extravasation had occurred. Coil embolization was performed with 0.010-inch coils. We evaluated technical success rate, clinical success rate and complications. Results: All five cases of bleeding occurred at the ascending colon, and were caused by diverticulosis in four cases, and an injury to the artery during polypectomy in one case. The 1.9-Fr. no-taper microcatheter could be inserted into the site of extravasation, the vasa recta, in all procedures and TAE was performed successfully. The disappearance of extravasation was confirmed in all cases following TAE. No patients exhibited any signs of recurrent bleeding or complication. Conclusion: The triaxial system appears to be effective and useful in superselective TAE for lower GI bleeding.

Triaxial system in bronchial arterial embolization for haemoptysis using N-butyl-2-cyanoacrylate

OBJECTIVE The application of bronchial artery embolization (BAE) using N-butyl-2-cyanoacrylate (NBCA) for haemoptysis was recently reported to be useful. A triple co-axial (triaxial) system consisting of a 4-Fr catheter, 2.7-Fr microcatheter and 1.9-Fr no-taper microcatheter has been developed. The aim of the present study was to evaluate the usefulness of the triaxial system in BAE using NBCA. METHODS 12 patients with haemoptysis, 8 males and 4 females with a median age of 64 years (range, 49-88 years), underwent BAE between August 2012 and October 2014. Medical records and images were reviewed, and the technical success rate, clinical success rate, haemoptysis-free rate and complications were evaluated. Technical success was defined as the complete cessation of the target artery as confirmed by digital subtraction angiography, whereas clinical success was defined as the cessation of haemoptysis within 24 h of BAE. Recurrent haemoptysis was defined as a total of >30 ml of bleeding per day. RESULTS The target artery was embolized successfully in all patients, and the technical success rate was 100% (12/12). The cessation of haemoptysis was achieved in 11 out of 12 patients within 24 h, and thus, the clinical success rate was 92% (11/12). The 6-, 12- and 24-month haemoptysis-free rates were 89%, 89% and 76%, respectively. No patients exhibited any signs of complications such as spinal ischaemia. CONCLUSION BAE using the triaxial system and NBCA appears to be a useful and safe procedure for haemoptysis. ADVANCES IN KNOWLEDGE The triaxial system contributes to safe and effective BAE using NBCA.

Time-resolved Magnetic Resonance Angiography for assessment of recanalization after coil embolization of visceral artery aneurysms.

Summary Background: Follow-up imaging after coil embolization of visceral artery aneurysms is important for detecting recanalization. However, CT examination is susceptible to coil artifacts, which sometimes makes it difficult to assess recanalization. We report 2 cases where recanalization was successfully visualized using time-resolved magnetic resonance angiography after coil embolization of visceral artery aneurysms (one case of right internal iliac artery aneurysm and one case of splenic artery aneurysm). Repeat coil embolization was successfully performed. Case Report: Case 1. An 80-year-old male patient with right internal iliac artery (IIA) aneurysm underwent coil embolization. Aneurysm was located at the bifurcation of the right IIA and therefore, after making a femorofemoral bypass, the distal part of the right IIA, aneurysm and the common iliac artery were embolized with a coil. One year later, the size of the aneurysm seemed to have increased on CT. However, the details were not determined because of metal artifacts. Thus, time-resolved MRA was performed and showed minute vascular flow inside the aneurysm. Angiography was subsequently performed and blood flow inside the aneurysm was visualized similar to the findings in time-resolved MRA. Coil embolization was performed once more and vascular flow inside the aneurysm disappeared. Case 2. A 36-year-old male patient with a splenic artery aneurysm underwent coil packing with preservation of splenic artery patency. Four years later, coil compaction was suspected in a CT scan, but CT could not evaluate recanalization because of severe metal artifacts. Angiography was subsequently performed, showing recanalization of the aneurysm as did the time-resolved MRA. Therefore, coil embolization of the aneurysm and splenic artery was performed again. Conclusions: Follow-up imaging after coil embolization of visceral artery aneurysms is important for detecting recanalization. However, it is sometimes difficult to assess recanalization with CT because of artifacts caused by metal. In our cases, recanalization of aneurysms was clearly shown by time-resolved MRA and re-embolization was successfully performed. In conclusion, time-resolved MRA appears to be useful in assessment of recanalization of visceral artery aneurysms after coil embolization.

Dual microcather-dual detachable coil technique in embolization for a congenital intrahepatic portosystemic venous shunt (IPSVS).

Abstract We report a 14-year-old boy with a large intrahepatic portosystemic venous shunt. The shunt seemed to be difficult to coil embolize because it was so large and short. However, it was successfully treated by coil embolization with a new dual microcatheter-dual detachable coil technique.