Time-resolved magnetic resonance angiography as a follow-up method for visceral artery aneurysm treated with coil-embolisation.

PURPOSE: The purpose of this study is to assess the feasibility and usefulness of time-resolved magnetic resonance angiography (TR-MRA) for follow-up of visceral artery aneurysms (VAAs) after embolotherapy. MATERIAL AND METHODS: Twenty-one VAAs (11 splenic, six renal, three internal iliac, and one superior pancreaticoduodenal artery aneurysms) in 18 patients (median age, 64 years; range, 36-88 years) previously treated by embolisation with platinum coils, were evaluated. The mean size of the aneurysm was 10.5 cm3 (range, 0.3-132 cm3). Among them, 19 lesions were treated by aneurysmal packing with or without distal-to-proximal embolisation. For the remaining two lesions, distal-to-proximal embolization alone was performed. The mean observation period after embolotherapy was 35 weeks (range, 4-216). All patients underwent TR-MRA following an intravenous bolus injection of gadolinium chelate. Recanalisation was diagnosed when any portion of the aneurysmal sac was enhanced in the arterial phase. RESULTS: On TR-MRA, two lesions were diagnosed as recanalised. They were confirmed by transcatheter arteriography and re-treated by embolotherapy. For the remaining 19 lesions, there were no findings of recanalisation on TR-MRA. CONCLUSIONS: TR-MRA appears to be a feasible method for follow-up examination of VAAs treated by embolotherapy.

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.

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.

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

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.

The variations of the middle colic vein tributaries: depiction by three-dimensional CT angiography.

OBJECTIVE: Laparoscopic transverse colectomy is challenging owing to technical difficulties in identifying an adequate dissection plane, ligating and dissecting lymph nodes around the middle colic vessels. One of the reasons for the technical difficulties is the complex relationship between the middle colic vein (MCV) and its tributary. So, defining the venous anatomy around the MCV before laparoscopic surgery seems important to avoid massive bleeding. The purpose of this study was to evaluate the depiction rate and variation of the MCV and its tributaries on three-dimensional CT angiography (3DCTA). METHODS: This study included 331 patients (203 males and 128 females) scheduled for laparoscopic surgery between June 2010 and April 2012. Most of the patients had gastric or colorectal cancer. Patients who needed emergency surgeries for obstruction or perforation were excluded. 3DCTA with an i.v. contrast medium was performed immediately following the administration of effervescent granules or room air insufflation. We assessed variations of the MCV tributaries using transaxial, multiplanar reconstructed images and volume-rendering images. RESULTS: The MCV could be identified in all patients. The MCVs drained into the superior mesenteric vein in 62.5% of patients, gastrocolic trunk of Henle in 29.3% of patients, inferior mesenteric vein in 4.8% of patients, splenic vein in 2.7% of patients and jejunal vein in 0.6% of patients. CONCLUSION: 3DCTA is useful in evaluating the anatomic variants of the MCV in pre-operative planning for laparoscopic surgery. ADVANCES IN KNOWLEDGE: Use of 3DCTA for the recognition of the anatomic complexity around the MCV and its tributary plays an important role in pre-operative planning for optimal patient outcome.

Incarceration of umbilical hernia after radiological insertion of a Denver peritoneovenous shunt.

We report a rare complication of incarceration of an umbilical hernia after Denver peritoneovenous shunt placement. A 50-year-old man presented with refractory ascites from liver cirrhosis. He also had an umbilical hernia. Because the ascites became uncontrollable, Denver peritoneovenous shunting was performed. The operation was successful and the ascites decreased. Ten days later, however, incarceration of the umbilical hernia occurred. A surgical repair was performed, but he died 2 days later. The cause of death was considered to be sepsis.