Embolization Microcoils Research Articles

Multiple gastric artery aneurysms managed by transcatheter arterial embolization

Abstract Rationale: Visceral artery aneurysms are very rare and carry a high risk of mortality. Gastric artery aneurysms (GAAs) account for less than 4% of visceral artery aneurysms. When the aneurysm ruptures, patients can present with epigastric pain, hematemesis, hematochezia, vomiting, hypotension, shock and other clinical manifestations. Patient concerns: We report a case of a 69-year-old man who presented with sudden abdominal pain, hypotension and melena. Diagnoses: Digestive tract hemorrhage secondary to one rupturing aneurysmamong three Gastric artery aneurysms. Interventions: Transcatheter arterial embolization with Gelatin Sponge Particle Embolic Agent, Glubran and an Embolization Microcoil was conducted to occlude the blood flow to the three GAAs. Outcomes: The patient returned safely to the ward without apparent complications and was discharged after eight days of hospitalization. At the 4-month follow-up, his condition remained stable, and there were no complications or symptoms observed. Lessons: Multiple GAAs are extremely rare and should be treated immediately. Transcatheter arterial embolization is the treatment for this rare lesion. Timely recognition and immediate treatment for ruptured GAAs usually results in a good prognosis.

CT-guided preoperative localization of ground glass nodule: comparison between the application of embolization microcoil and the locating needle designed for pulmonary nodules

To compare the efficacy and safety of pre-operative localization of ground glass nodule (GGN) using embolization microcoils and the locating needles designed for pulmonary nodules. From June 2019 to December 2020, 429 patients who received CT-guided localization of single GGN before video-assisted thoracoscopic surgery (VATS) were enrolled. The diameter and depth of GGNs were 0.84 ± 0.39 cm and 1.66 ± 1.37 cm. Among 429 cases, the first 221 GGNs were marked with microcoils (the microcoil group), and the remaining 208 GGNs were marked with the locating needles designed for pulmonary nodules (the locating needle group). SPSS 17.0 statistical software was used to compare the marking success rate, marking time, marking-related complications between two groups. p values < 0.05 were considered statistically significant. The marking time in the microcoil group was longer than that in the locating needle group (11.1 ± 3.9 vs 8.2 ± 2.0 min, t = -7.87, p = 0.000). The marking success rate in the microcoil group was lower than that in the locating needle group (91.4% vs 98.6%, χ2 = 11.27, p = 0.001). In the microcoil group, marking failures included 16 cases of microcoil dislocation and 3 cases of unsatisfactory microcoil position, while all 3 cases of marking failure in the locating needle group were due to unsatisfactory anchor position. No significant differences in the incidence of total complications (23.1% vs 22.1%), pneumothorax (18.1% vs 19.2%), hemorrhage (9.5% vs 9.1%), and hemoptysis (1.8% vs 1.4%) were observed between the two groups. All the complications were minor and did not need special treatment. Except for one case in the microcoil group, which was converted to thoracotomy, the remaining 428 GGNs were successfully resected by VATS. It is safe and effective to perform pre-operative localization of GGN using either embolization microcoil or the locating needle designed for pulmonary nodules. The locating needle is superior to microcoil for marking GGN in terms of procedure time and the success rate. The complication rate of both methods is similar. The locating needle designed for pulmonary nodules has recently been used to mark pulmonary nodule. Its structure can effectively avoid dislocation after localization, and the marking process is simple and quick. Compared with localization using microcoil, it takes less time and has higher success rate to mark GGNs using the locating needle. The complication rate of both methods is similar.

1949 Modern Coils and Glue: An Evolving EUS Application in the Management of Gastric Varices

INTRODUCTION: Ethylene vinyl alcohol (EVOH) is a liquid embolic agent approved for cerebrovascular lesions. DMSO solvent dissipates into the blood, causing the EVOH copolymer and suspended tantalum to precipitate in situ into a spongy, coherent embolus. Their role in the management of gastric varices is still unknown. We are presenting our experiences with this novel echoendoscope (EUS) guided use of EVOH to achieve gastric variceal obturation (GVO). CASE DESCRIPTION/METHODS: Case 1 : 44-year-old male with decompensated cirrhosis presented with melena. EGD showed large gastric varix (GOV-2). EUS- guided coiling and EVOH glue injection was planned. Gastric varices were identified using a linear echoendoscope at 7.5 MHz and 22G FNA needle was then advanced into varix with position confirmed by aspirating blood. Three embolization microcoils (5 mm/mm2, 8 mm/4mm, 7 mm/3mm; proximal end diameter/distal end diameter) were placed into the varix followed by needle flush with a 0.8 ml DMSO (dimethyl sulfoxide). Post DMSO flush, 5 mL EVOH glue was injected with excellent flow reduction on EUS doppler. 0.8 ml of DMSO was again used to flush the needle. Patient tolerated procedure well and had no signs of bleeding prior to discharge. Case 2 : 39-year-old male with history of alcoholic and HCV cirrhosis and hepatocellular carcinoma, two prior banding procedures for bleeding esophageal varices, gastric varices, presented with signs and symptoms of decompensated cirrhosis, hematemesis and melena. EGD with banding was done for large esophageal varices with stigmata with successful hemostasis. Large gastric varix (GOV-1) was also discovered. Coiling and glue was injected with similar EUS guided technique as above (sixteen embolization microcoils of varying sizes (8 mm/4 mm, 7 mm/3 mm, 5 mm/2 mm); 3 mL EVOH glue injection). Post procedural EUS doppler imaging showed excellent flow reduction. DISCUSSION: EVOH is well-known as catheter based embolic therapy for neurovascular lesions. Its application under EUS image guidance for gastric varices has not been reported yet to our knowledge thus making our case as unique. However larger, prospective multicenter trials with EVOH will be required to study rebreeding rates and long-term outcomes in the management of gastric varices.

Proximal Fallopian Tubal Embolization by Interventional Radiology prior to Embryo Transfer in Infertile Patients with Hydrosalpinx: A Prospective Study of an Off-label Treatment

To evaluate in vitro fertilization (IVF) outcomes of proximal fallopian tube embolization by interventional radiology compared with laparoscopic salpingectomy before embryo transfer (ET) in patients with hydrosalpinx. A single-center, off-label, nonrandomized prospective study. Academic university hospital. One hundred fifty-five patients with hydrosalpinx were identified on ultrasound or hysterosalpingography desiring IVF between April 2016 and December 2017. Radiologically guided tubal occlusion with embolization microcoils (RTO-EM) and laparoscopic salpingectomy. Of the 155 analyzed patients, 42 were treated with RTO-EM and 113 with laparoscopic salpingectomy. The subsequent IVF outcomes, including implantation, clinical pregnancy, miscarriage, ectopic pregnancy, and ongoing pregnancy (i.e., a fetal heartbeat on ultrasound beyond 10 weeks) were compared between the 2 groups. Implantation and clinical pregnancy per ET cycle in the RTO-EM group were similar to that of the salpingectomy group (26.7% vs 30.2% [p = .51] and 39.0% vs 45.3% [p = .40], respectively), with a similar miscarriage rate. There was no statistically significant difference in ectopic pregnancies between the 2 groups. Moreover, no difference was detected in ongoing pregnancy per cycle between the 2 groups (33.9% vs 41.2%; p = .32). The ongoing-pregnancy rate per patient following RTO-EM was 47.6% (20 of 42) compared with 61.9% (70 of 113) following salpingectomy (odds ratio, 0.56; 95% confidence interval, 0.27-1.14; p = .11). Pregnancy in the RTO-EM group was comparable to the salpingectomy group in patients with hydrosalpinx before ET treatment. RTO-EMs may be an alternative to salpingectomy for patients with hydrosalpinx planning for IVF-ET.

Priapismo de bajo flujo transformado en priapismo de alto flujo por fístula arterio-lacunar secundaria a la técnica de Winter

Priapism is a pathological condition which is a persistent penile erection beyond sexual stimulation. We report a patient of 80 years, initially diagnosed by medical history, blood gas values of the corpora cavernosa and penile color Doppler ultrasound of low-flow priapism. During the performance of the technique of Winter occurs iatrogenically bilateral laceration of the dorsal arteries, causing arterial-lacunar fistula and therefore a high-flow priapism. We performed selective arteriography of the pudendal, not being eco-color Doppler conclusively that showed that fistula and allowed superselective bilateral embolization microcoils.

New Embolization Microcoil Consisting of Firm and Flexible Segments: Preliminary Clinical Experience

To describe the preliminary clinical experience with a new embolization microcoil. The microcoil was made of a platinum coil spring, and consisted of firm and flexible segments. The firm segment functioned as an anchor and the flexible segment was well compacted to occlude the arteries. No Dacron fiber was attached. Seventy-one new microcoils were placed via microcatheters in 28 visceral arteries of 17 patients. Two other types of microcoils with Dacron fibers were used together in 8 arteries. Sixty-nine new microcoils were placed and compacted successfully. Two coils were misplaced; one was retrieved and the other was left in the migrated artery, which remained patent 5 months later. All 28 arteries were occluded, and the goals of intervention were achieved successfully in all 17 cases. The new microcoils anchored and compacted well in the arteries. The clinical feasibility of this coil design was confirmed. The additional use of other types of microcoils with Dacron fiber was necessary to obtain rapid occlusion in some cases.

Determination of ventilatory liver movement via radiographic evaluation of diaphragm position

Purpose: To determine the accuracy of estimation of liver movement inferred by observing diaphragm excursion on radiographic images. Methods and Materials: Eight patients with focal liver cancer had platinum embolization microcoils implanted in their livers during catheterization of the hepatic artery for delivery of regional chemotherapy. These patients underwent fluoroscopy, during which normal breathing movement was recorded on videotape. Movies of breathing movement were digitized, and the relative projected positions of the diaphragm and coils were recorded. For 6 patients, daily radiographs were also acquired during treatment. Retrospective measurements of coil position were taken after the diaphragm was aligned with the superior portion of the liver on digitally reconstructed radiographs. Results: Coil movement of 4.9 to 30.4 mm was observed during normal breathing. Diaphragm position tracked inferior-superior coil displacement accurately (population σ 1.04 mm) throughout the breathing cycle. The range of coil movement was predicted by the range of diaphragm movement with an accuracy of 2.09 mm (σ). The maximum error observed measuring coil movement using diaphragm position was 3.8 mm for a coil 9.8 cm inferior to the diaphragm. However, the distance of the coil from the top of the diaphragm did not correlate significantly with the error in predicting liver excursion. Analysis of daily radiographs showed that the error in predicting coil position using the diaphragm as an alignment landmark was 1.8 mm (σ) in the inferior-superior direction and 2.2 mm in the left-right direction, similar in magnitude to the inherent uncertainty in alignment. Conclusions: This study demonstrated that the range of ventilatory movement of different locations within the liver is predicted by diaphragm position to an accuracy that matches or exceeds existing systems for ventilatory tracking. This suggests that the diaphragm is an acceptable anatomic landmark for radiographic estimation of liver movement in anterior-posterior projections for most patients.

Localization of pulmonary nodules using suture-ligated microcoils.

Percutaneous localization of pulmonary nodules in five patients was performed utilizing suture-ligated embolization microcoils and CT guidance. Each localization was performed prior to video-assisted thoracoscopic wedge resection of the targeted nodules. Each suture-ligated microcoil was placed within 1.0 cm of the targeted pulmonary nodule. The attached suture served as a guide to direct accurate resection of the nodules. This technique is easily performed and provides a reliable alternative to nodule localization prior to thoracoscopic resection.

A novel method of transthoracic lung nodule localization

Introduction: High-resolution computed tomography (CT) scans now detect smaller pulmonary nodules than were ever detected before, which has created new clinical challenges regarding the timing and method of obtaining a tissue diagnosis. Video-assisted thoracic excisional biopsy is the preferred method of obtaining tissue, but with smaller lesions that are not pleural-based, localization is necessary because tactile evaluation is limited. This study evaluated the feasibility of the deployment of suture-ligated vascular embolization microcoils (microcoils) as a method for localizing peripheral pulmonary nodules before video-assisted thoracoscopic surgery (VATS) and compared the microcoils with hookwires. MethodsSix 3-0 Prolene® microcoils and 6 hookwires were injected into 3 freshly harvested goat lungs. Fluoroscopy, CT, and direct visualization were utilized to evaluate the shape, location, and displacement characteristics of the deployed microcoils and hookwires. The forces required to displace these devices were measured by tensiometry. Displacement data were correlated with the force needed to deform a vascular embolization microcoil and hookwire out of tissue. An identical technique using a 4% agarose gel was performed to visualize the deformation characteristics. ResultsSignificantly different loads (0.29 ± .03 vs 0.72 ± .27 lbs, p < 0.006) were required to displace microcoils and hookwires, respectively, from lung tissue when a constant, slow displacement velocity of 0.5 in/min was applied. The loads for displacement from agarose gel of the microcoil and hookwire were 0.15 ± .04 and 0.32 ± .17 lbs, (p = 0.03), respectively. At a rapid velocity, an average force of 0.95 ± 0.41 lbs was required to displace a microcoil from agarose; an average of 0.74 ± 0.34 lbs of force was needed to displace a hookwire. To straighten a microcoil required 0.065 lbs of force, and 2.5 lbs of force was required to straighten a hookwire beyond 90°. Displacement of a hookwire causes lung tissue to tear, often with tissue remaining on the barb, whereas essentially no damage to lung tissue is observed with microcoil displacement. The observed gel disruption mimicked the lung tissue, demonstrating the tearing property of the wire and the straightening characteristic of the coil. ConclusionForces within the physiologic range will displace both microcoils and hookwires from lung tissue. The decreased rigidity of microcoils, their ability to be left in situ if necessary, and diminished disruption of lung parenchyma with displacement suggest that it is feasible to use this system in human subjects as a technique for pulmonary nodule localization before minimally invasive pulmonary resection.

Placement of endovascular embolization microcoils to localize the site of breast lesions removed at stereotactic core biopsy.

In 13 cases, a breast abnormality was inadvertently removed during stereotactic core biopsy, and a 0.5- or 1.0-cm-long endovascular embolization microcoil was placed to mark the biopsy site. In seven patients, the microcoils allowed successful preoperative localization of the lesion site. In six patients, 6-month follow-up mammograms showed no change in microcoil position. Placement of embolization microcoils helped localize the site of breast lesions removed during stereotactic core biopsy.

Hemobilia after Percutaneous Transhepatic Biliary Drainage: Treatment with Transcatheter Embolotherapy

Thirteen of 333 patients who underwent percutaneous biliary drainage (PBD) developed severe hemobilia. Hepatic arteriography successfully demonstrated the source of hemorrhage in all 13 patients. Lesions included hepatic artery pseudoaneurysm in nine, hepatic artery-bile duct fistulas in four, and a hepatic artery-portal vein fistula in one patient. Hemobilia occurred from 1 day to 1.8 years (mean, 100 days) following catheter placement. Embolization agents used included Hilal embolization microcoils, occluding spring emboli, cyanoacrylate, detachable balloons, and gelatin sponge pledgets. A single agent was used in eight cases (62%), multiple agents were used in four cases (31%), and in one case (7%), spontaneous thrombosis of the pseudoaneurysm occurred during catheter manipulation. In five patients, the source of the hemorrhage could only be demonstrated following removal of the biliary catheter(s) over guide wire(s). Initial embolization was successful in stopping hemobilia in 12 patients. One patient required repeat embolization after 4 months. Postembolization complications included hepatic abscess formation in two patients and a sterile hepatic infarct in one patient. This series indicates that transcatheter embolotherapy is an effective method for the treatment for severe hemobilia.

Ferromagnetism and magnetic resonance artifacts of platinum embolization microcoils

We performed in vitro tests of ferromagnetism of platinum microcoils of two manufacturers. In addition, we performed in vitro magnetic resonance imaging (MRI) on these two devices to determine their levels of magnetic susceptibility artifact production. We found that both devices were nonferromagnetic and produced a very low level of artifact during MRI. In vivo MRI of a dog and 2 patients having previous placement of platinum microcoils was performed without coil migration or significant artifact production. Platinum microcoils are highly MR-compatible.