Systematic Review of Treatment for Unruptured Intracranial Aneurysms: Clipping Versus Coiling.

AIM: To compare endovascular coiling and surgical clipping for the evaluation of clinical outcomes in patients with unruptured intracranial aneurysms. MATERIAL AND METHODS: We searched MEDLINE, EMBASE, the Cochrane Library and three Chinese domestic electronic databases, namely, Wanfang, CNKI and VIP for studies published between January 1990 and January 2018. We included controlled clinical studies comparing clinical outcomes between surgical clipping and endovascular coiling treatments. Two researchers extracted the data and assessed the quality of the studies, and a meta-analysis was performed using RevMan 5 software. RESULTS: We analysed a total of 23 controlled clinical studies including 117,796 cases. Meta-analysis demonstrated similar ischaemia rates between clipping and coiling with an odds ratio [OR] of 1.36 (95% CI: 0.77?2.40). The occlusion rate and bleeding risk were higher with clipping than coiling; the pooled ORs were 5.31 (95% CI: 3.07?9.19) and 2.39 (95% CI: 1.82?3.13), respectively. In addition, clipping resulted in a longer hospital stay (OR = 2.90, 95% CI: 2.14?3.65) than coiling did. Patients who underwent clipping had a higher short-term mortality (OR = 1.99, 95% CI: 1.70?2.33) and neurological deficit rate (OR = 2.05, 95% CI: 1.73? 2.44) compared with those who underwent coiling. However, 1 year mortality and deficit rate were similar for both clipping and coiling, with pooled ORs of 0.75 (95% CI: 0.41?1.38) and 0.94 (95% CI: 0.53?1.67), respectively. Funnel plots did not demonstrate a publication bias, with the exception of ischaemic outcome, and sensitivity analysis showed consistent results. CONCLUSION: Our study demonstrates that coiling is associated with a lower rate of occlusion, shorter hospital stay, lower bleeding risk and lower short-term mortality and morbidity compared with clipping. In terms of ischaemic risk, 1 year mortality and morbidity, coiling and clipping bear a similar risk. In addition, we speculate that surgical clipping may have a better outcome than endovascular coiling in the long term especially in young patients. Further research is needed to confirm our conclusion.

Midterm follow-up after embolization of intracranial aneurysms proximal to the circle of Willis with the Silk Vista flow diverter: the I-MAMA registry.

PURPOSE: The aim of this registry was to assess technical success, procedural safety and mid- to long-term follow-up results of the Silk Vista "Mama" (SVM) flow diverter (BALT, Montmorency, France) for the treatment of proximal intracranial aneurysms. METHODS: Between August 2020 and March 2022, data from nine Italian neurovascular centres were collected. Data included patients' clinical presentation, aneurysms' size, location and status, technical details, overall complications and mid- to long-term angiographic follow-up. RESULTS: Forty-eight aneurysms in 48 patients were treated using the SVM. Most aneurysms were small (≤ 10 mm: no. 29, 60%) and unruptured (no. 31, 65%); 13 aneurysms were recurrent after coiling or clipping. 37/48 aneurysms involved the internal carotid artery (77%). Optimal opening and complete wall apposition of the device were achieved in 46 out of 48 cases (96%). Four intra- or periprocedural complications occurred (two thrombotic complications successfully resolved, one cerebellar ischemia, one perirenal hematoma), without new neurological deficit. No significant intra-stent stenosis or stent displacement was observed during follow-up. No FD-related morbidity nor mortality was reported. At midterm (6-12 months) to long-term (> 12 months) follow-up, complete aneurysm occlusion (OKM D) was achieved in 76% of cases. Eighty-eight percent of patients had complete aneurysm occlusion or entry remnant (OKM D + C). CONCLUSIONS: Our experience suggests that the new generation of low-profile SVM flow diverter for the treatment of proximal intracranial aneurysms is safe and effective, with low rates of intraprocedural complications and acceptable mid- to long-term occlusion rate.

Large Single-Center Experience with Short-Term Follow-up of Neqstent-Assisted Coiling.

BACKGROUND AND PURPOSE: Endovascular treatment of wide-neck bifurcation aneurysms has historically proved difficult with variable outcomes. Different endovascular techniques such as balloon-assisted coiling, stent-assisted coiling, or intrasaccular devices provide a varied range of efficacy and safety. Neqstent-assisted coiling is a new device and technique that aim to provide a maximum of both. We analyzed the early clinical and radiologic outcomes after the use of this new technique and device in our practice. MATERIALS AND METHODS: This study was a retrospective analysis of ruptured and unruptured intracranial aneurysms treated with the Neqstent. The primary radiologic outcomes were quantified on DSA, CTA, or MRA using the modified Raymond-Roy criteria. The outcomes were defined as immediate complete occlusion (modified Raymond-Roy criteria 1) and complete (modified Raymond-Roy criteria 1) and adequate occlusion (modified Raymond-Roy criteria 1 and modified Raymond-Roy criteria 2) at 6 months posttreatment. The primary safety outcome was the rate of device-related adverse events. Secondary safety outcomes included time to discharge and change in the mRS score at 6-month follow-up. RESULTS: Twenty patients were treated with the Neqstent from November 2020 to January 2023. Nine had unruptured aneurysms, and 11 were patients with subarachnoid haemorrhage due to ruptured aneurysms. Eighteen of 20 aneurysms (90%) treated demonstrated complete occlusion (modified Raymond-Roy criteria 1) on immediate postembolization angiograms. Sixteen of 17 aneurysms treated (94.1%) remained adequately occluded on 6-month follow-up (modified Raymond-Roy criteria 1 and modified Raymond-Roy criteria 2). Immediate postoperative complications occurred in 2 patients; only 1 patient had residual neurologic deficits at 6 months (mRS = 2). CONCLUSIONS: Management of large, wide-neck aneurysms remains difficult, with high rates of recurrence and complications. The use of the Neqstent shows promising short-term results for the treatment of complex wide-neck aneurysms. Initial complication rates for our cohort were relatively high. However, this result is likely related to the initial learning experience of device deployment and the use of antiplatelets.

Pre-emptive Aortic Side Branch Embolization during Endovascular Aneurysm Repair Using the Excluder Stent-Graft System: A Prospective Multicenter study.

PURPOSE: To evaluate the effectiveness and safety of pre-emptive transcatheter arterial embolization (P-TAE) for aortic side branches (ASBs) to prevent Type 2 endoleaks (EL2) before endovascular aneurysm repair (EVAR) using the Excluder stent-graft system (Excluder). MATERIALS AND METHODS: In this prospective, multicenter study, 80 patients (mean age, 79.1 years [SD ± 6.7]; 85.0% were men; mean aneurysmal sac diameter, 48.4 mm [SD ± 7.4]) meeting the eligibility criteria were prospectively enrolled from 9 hospitals. Before EVAR, P-TAE was performed to embolize the patent ASBs originating from the abdominal aortic aneurysm. Contrast-enhanced computed tomography (CT) was performed at 1 month and 6 months after EVAR. The primary endpoint was EL2 incidence at 6 months, and the secondary endpoints were aneurysmal sac diameter changes at 6 and 12 months, P-TAE outcomes, adverse events related to P-TAE, reintervention, and aneurysm-related mortality. RESULTS: All patients successfully underwent P-TAE without serious. Coil embolization was successful in 81.6% of ASBs. EL2 incidence at 6 months was identified in 18 of 70 (25.7%) patients. Aneurysmal sac diameter shrinkage (≥5 mm) was observed in 30.0% of patients at 6 months and in 40.9% at 12 months. Only 1 patient required reintervention for EL2 within 1 year of EVAR; aneurysm-related deaths were not observed. CONCLUSIONS: P-TAE for ASBs before EVAR using Excluder is a safe and effective strategy. It aids in achieving early aneurysmal sac shrinkage and reduces EL2 reintervention at 1 year after EVAR.

Safety and Outcomes of the Off-Label Treatment of Intracranial Aneurysms with Pipeline Embolization Device: A Systematic Review and Meta-analysis.

BACKGROUND: Off-label use of pipeline embolization devices (PEDs) has been increasingly used for endovascular treatment of intracranial aneurysms. Numerous articles have highlighted the safety and effectiveness of PED placement from independent centers for both on- and off-label indications. There remains a paucity of information that considers overall safety and efficacy of off-label PED placement across the existing literature. Our objective is to systematically review the safety and occlusion outcomes of PED off-label use in intracranial aneurysm embolization. METHODS: A systematic search of PubMed and Embase was performed to identify studies on off-label use of PED. The selected studies provided relevant information, including study characteristics, patient demographics, clinical outcomes, peri-procedural complications, and long-term outcomes, which were subjected to meta-analysis. RESULTS: Twelve studies met the inclusion and exclusion criteria. There were 747 patients and 791 aneurysms included for analysis. Among the patient, 69.2% were female, with an age range of 16 to 80 years. The overall incidence rates for ischemic and hemorrhagic complications were 7% (95% CI: 4%-10%) and 2% (95% CI: 0%-4%), respectively. The mortality rate was 1% (95% CI: 0%-4%). The occlusion rates of aneurysm at initial follow up and 1 year follow-up were 82% (95% CI: 72%-91%) and 81% (95%CI: 75%-86%), respectively. Meta-regression analysis indicated no correlation between occlusion rate and factors such as age, sex, aneurysm size, location, morphology, rupture, or history of treatment. CONCLUSIONS: Despite variations in results observed in single-center studies, this meta-analysis provides evidence supporting the safety and efficacy of PED off-label use.

Optimizing Patient Care: A Multicentric Study on the Clinical Impact of Sim&Size™ Simulation Software in Intracranial Aneurysm Treatment With Pipeline Embolization Devices.

BACKGROUND: To determine the clinical effects (stent size, and number of stents used) of the Sim&Size™ simulation software on the endovascular treatment of unruptured saccular intracranial aneurysms with Pipeline Embolization Devices (PED). METHODS: This study is a retrospective analytical multicenter study of patients treated with PED (Flex and Flex with SHIELD) for intracranial aneurysm in FOSCAL clinic and CHU de Montpellier. RESULTS: The study included 253 patients, of which 75 were treated in Colombia and 178 were treated in France. The majority of patients were women (83.8%), with a median age of 57.48 years, and had large vessel location (88.1%), with most aneurysms located in the ICA paraclinoid segment (56.8%). Patients in the group with Sim&Size™ simulation had shorter stents than those without simulation (15.62 mm versus 17.36 mm, P-value = 0.001). Also, a lower proportion of these patients required more than one stent (1.4% versus 7.3%, P-value = 0.022). There were 7 complications reported in the group that used the Sim&Size™ simulation software, compared to 9 complications in the group that did not use the software. CONCLUSIONS: Using Sim&Size™ simulation software for endovascular treatment of patients with intracranial aneurysms using PED reduces the stent length and decreasing the number of devices needed per treatment.

Long-Term Safety and Efficacy of Pipeline Embolization Device in Anterior and Posterior Circulation Aneurysms: A Systematic Review and Meta-Analysis.

BACKGROUND: Flow diversion using the pipeline embolization device (PED) has been a paradigm shift for anterior circulation (AC) aneurysms. However, only a few studies report the long-term (≥1 year) angiographic and clinical outcomes for posterior circulation (PC) aneurysms. This study aims to compare the long-term safety and efficacy of treatment of AC and PC aneurysms with PED. METHODS: The databases included Ovid MEDLINE, Ovid EMBASE, Ovid Cochrane, and Scopus. Studies with at least 10 patients and 1-year follow-up were included. Twenty-four studies met our inclusion criteria. A random effect meta-analysis was performed to estimate the ischemic and hemorrhagic complications. A meta-analysis of proportions was performed to estimate the pooled rates of long-term complete aneurysmal occlusion, symptomatic stroke, aneurysmal rupture, and intracranial hemorrhage. RESULTS: There were 1952 aneurysms, of which 1547 (79.25%) were in the AC and 405 (20.75%) in the PC. The 1-year occlusion rate was 78% in AC compared to 73% in PC aneurysms (P < 0.01). The symptomatic infarct rate was 5% in AC compared to 13% in PC (P < 0.01). While the rupture rate was 1% in AC compared to 4% in PC (P = 0.01), the rate of intracranial hemorrhage was 2% for both (P = 0.99). CONCLUSIONS: The long-term occlusion rate after PED was higher in AC aneurysms, and the cumulative incidence of stroke and aneurysm rupture was higher in PC aneurysms.

Endovascular Management of Aortic Stump Blowout by Parallel Grafting and Coil Embolization of Visceral Aorta.

Aortic graft and endograft infections remain a significant source of morbidity and mortality after abdominal aortic aneurysm repair. With graft excision and extra-anatomic bypass, an infrarenal aortic stump remains which can have suture line dehiscence and catastrophic stump blowout. Treatment of this is extremely challenging, especially for severely co-morbid patients who cannot undergo major surgery, or in patients with a hostile abdomen. We present a case study of a 74-year-old male found to have an aortoenteric fistula (AEF). This case broadens operative options for this type of patient population by demonstrating an endovascular technique for addressing aortic stump blowout by parallel grafting and coil embolization of the visceral aorta.

A Novel Microsnare and Microwire Coil Retrieval Technique.

Coil migration during endovascular embolization is a complication that can result in thromboembolic occlusion leading to potentially large infarcts if not removed. Microsnares are commonly used to remove migrated coils. Current techniques, however, struggle in cases where the microsnare is unable to loop over and secure a free end of the coil. We present a case in which a microsnare combined with a microwire successfully removed a migrated coil in a patient with a bleeding hepatic pseudoaneurysm post-embolization. This technique proved beneficial when traditional methods were insufficient, especially in small vessels or coil packs that cannot be snared. The synergy of the microsnare and microwire technique presents a promising solution for challenging migrated coil retrievals.

Gekko Coil System for Intracranial Aneurysms Treatment in China (GREAT-China): A Prospective Randomized Controlled Open-Label Noninferiority Trial.

OBJECTIVE: This study aimed to evaluate the safety and efficacy of the Gekko coil system in treating intracranial aneurysms (IAs) in clinical practice. METHODS: A prospective multicenter randomized open-label parallel positive control noninferiority trial was conducted by 11 centers in China. Patients with a target IA were randomized 1:1 to coiling with either Gekko or Axium coils. The primary outcome was successful aneurysm occlusion at 6 months postoperative follow-up, whereas the secondary outcomes included the successful occlusion aneurysm rate in the immediate postoperative period, recanalization rate at the 6 months follow-up, and technical success and security. RESULTS: Between May 2018 and September 2020, 256 patients were enrolled and randomized. Per-protocol analysis showed that the successful aneurysm occlusion rate at 6 months was 96.08% for the Gekko coil group compared with 96.12% in the Axium coil group, with a difference of -0.04% (P = 0.877). The successful immediate aneurysm occlusion rates were 86.00% and 77.45% in the Gekko coil group and the Axium coil group, respectively, showing no significant difference between the 2 groups (P = 0.116), whereas the recanalization rates during the 6 months follow-up were 2.02% and 1.96% in the Gekko and Axium coil groups, respectively, which was not statistically significant (P = 1.000). CONCLUSIONS: This trial showed that the Gekko coil system was noninferior to the Axium coil system in terms of efficacy and safety for IA embolization. In clinical practice, the Gekko coil system can be considered safe and effective for treating patients with IA.

Tumor Embolization via the Meningohypophyseal and Inferolateral Trunk in Patients with Skull Base Tumors Using the Distal Balloon Protection Technique.

BACKGROUND AND PURPOSE: Tumor embolization through the meningohypophyseal trunk and inferolateral trunk is known to be effective in skull base tumors; however, microcatheter cannulation into these arteries is difficult, and the number of cases that can be safely embolized is limited. In this study, we present a novel embolization procedure for the meningohypophyseal trunk and inferolateral trunk using the distal balloon protection technique and detail its clinical efficacy and complication risks. We developed this procedure to allow safe embolization in patients who cannot be adequately cannulated with microcatheters into these arteries. MATERIALS AND METHODS: Patients who underwent meningohypophyseal trunk or inferolateral trunk embolization using the distal balloon protection technique for skull base tumors at our institution between 2010 and 2023 were included. In this procedure, the ICA was temporarily occluded with a balloon at the ophthalmic artery bifurcation, the microcatheter was guided to the meningohypophyseal trunk or inferolateral trunk vicinity, and embolic particles were injected into the arteries. The balloon was deflated after the embolic particles that had refluxed into the ICA were aspirated. RESULTS: A total of 25 meningohypophyseal trunks and inferolateral trunks were embolized during 21 operations. Of these 25 arteries, only 9 (36.0%) were successfully cannulated with microcatheters. Nevertheless, effective embolization was achieved in all cases. Permanent complications occurred in only 1 case (4.8%) in which the central retinal artery was occluded during inferolateral trunk embolization, resulting in a visual field defect. No permanent complications resulting from the embolic cerebral infarction were observed. Of 16 cases that underwent MR imaging within a week after embolization, however, 11 (68.8%) demonstrated embolic cerebral infarctions. CONCLUSIONS: In patients with skull base tumors with meningohypophyseal trunk or inferolateral trunk feeders that cannot be catheterized directly, embolization using the distal balloon protection technique for tumor supply can be considered as a salvage technique.

Traumatic Iliac Arteriovenous Fistula Treated With the Amplatzer Vascular Plug II: A Case Report and Literature Review.

Traumatic iliac arteriovenous fistula is a rare complication of vascular injury. Open surgical repair has an incidence of postoperative complications. In recent years, endovascular treatment has shown better efficacy. We report a 62-year-old female AVF patient with a stab injury history of more than 16 years. Computed tomography angiography (CTA) revealed a large arteriovenous fistula between the right internal iliac artery and the common iliac vein. After considering the patient's relevant conditions, an endovascular approach was satisfactorily performed with the implantation of an Amplatzer Vascular Plug II to interrupt the abnormal vascular communication and maintain arterial and venous patency. The final control images showed closure of the arteriovenous communication.

Flow Diverters with Surface Modification in Patients with Intracranial Aneurysms: A Systematic Review and Meta-Analysis.

BACKGROUND: Flow diverters with surface modification (FDSM) are increasingly being used in the treatment of intracranial aneurysms (ANs). We aimed to evaluate the effectiveness and safety across different devices and antiplatelet therapies using a systematic review and meta-analysis. METHODS: A systematic review was performed to identify original studies of ≥10 patients with intracranial ANs treated with FDSM from database inception through August 2023. Primary effectiveness outcome was the rate of complete AN occlusion at follow-up ≥6 months. Safety outcomes included ischemic stroke, hemorrhage, and in-stent thrombosis, and were stratified by FDSM devices and antiplatelet therapies. Certainty of evidence was evaluated following the Grading of Recommendations, Assessment, Development, and Evaluations approach. RESULTS: Twenty-seven studies were included, yielding 2161 patients with 2373 ANs. A total of 70.5% of the ANs were located on the internal carotid artery (ICA). Total 10.3% were acutely ruptured. The complete AN occlusion rate was 72.3% at follow-up ≥6 months. Sensitivity analysis in the ICA AN cohort yielded comparable occlusion rates between Pipeline Flex Embolization Device-Shield (80.4%) and Phenox-hydrophilic polymer-coated (77.5%, P = 0.54), but a lower 66.2% rate for Flow Redirection Endoluminal Device-X (P = 0.02). The rate of in-stent thrombosis and stenosis tended to be higher in Phenox-hydrophilic polymer-coated (3.4%) and Flow Redirection Endoluminal Device-X (4.3%) versus Pipeline Flex Embolization Device-Shield (0.8%, P = 0.05). CONCLUSIONS: FDSM were safe with satisfactory effectiveness for intracranial ANs. More specific investigations are warranted to explore their performance in ANs beyond the ICA and optimal antiplatelet therapy.

Single coil endovascular embolization of very tiny (≤2 mm) intracranial aneurysms: one center's experience.

Background: To investigate the safety and efficacy of endovascular embolization of very tiny (≤2 mm) intracranial aneurysms with single coil and summarize experience. Methods: A retrospective analysis was performed for 15 consecutive patients with very tiny aneurysms treated by coil embolization alone or stent-assisted coil embolization between January 2017 and January 2020. 15 patients with six unruptured aneurysms and nine ruptured aneurysms were included in this study. There were eight males and seven females with a mean age of 50.0 ± 5.2 years (range 41 to 57 years old). Intraoperative complications, imaging outcomes, clinical outcomes and follow-up data were analyzed. Results: All aneurysms were embolized with a single coil. Lvis stents were used in all coil assisted embolizations. The embolization success rate was 100%. The average volume embolization ratio (VER) of aneurysm embolization was 53.7 ± 25.5%. An intraoperative aneurysm re-rupture complication occurred in one patient (6.7%). 11 patients (73.3%) had immediate complete occlusion after embolization. After a mean follow-up period of 6.7 ± 1.4 months, 13 patients (86.7%) had complete occlusion. No patients had aneurysm re-rupture, an ischemic event or recurrence during follow-up. All patients achieved favorable clinical outcomes with a modified rankin scale (MRS) of 0-2. Conclusions: This study demonstrates that endovascular embolization of very tiny intracranial aneurysms with a single coil is safe and effective. However, the follow-up period was not long enough and studies with larger numbers of patients are required. The summary of experience reported here is expected to provide significant patient benefits.

Clinical Features and Treatment Outcomes of Pseudoaneurysm Following Pancreatic Resection.

BACKGROUND/AIM: Management strategies for pseudoaneurysm rupture after pancreatic resection have not yet been firmly established due to its low incidence and effects of environmental variability among centers. This study aimed to provide a basis for treatment strategy improvement. PATIENTS AND METHODS: Clinical features and outcomes of 29 patients who experienced pseudoaneurysm formation or rupture following pancreatic resection were retrospectively reviewed. RESULTS: The incidence of pseudoaneurysm formation was 2.8%. In 28 of 29 patients, pseudoaneurysm was identified via emergent dynamic computed tomography (CT). The rates of complete cessation of bleeding by interventional radiology (IVR) and surgical intervention were 88% and 100%, respectively. Mortality rate was 13.8%. Four patients treated by IVR died, including three of massive bleeding and one of liver failure. CONCLUSION: Patients with suspected pseudoaneurysm rupture after pancreatic resection should undergo immediate CT. Open surgery is preferable for patients with incomplete hemostasis by IVR or those who cannot immediately undergo IVR, however, IVR is an effective alternative.

Midterm Outcomes of Endovascular Abdominal Aortic Aneurysm Repair with Prevention of type 2 Endoleak by Intraoperative Aortic Side Branch Coil Embolization.

OBJECTIVE: The midterm results of endovascular abdominal aortic aneurysm repair (EVAR) with aortic side branch coil embolization during EVAR was evaluated. METHODS: Our center began coil embolization for all patent inferior mesenteric artery (IMA) and lumbar artery (LA) with an inner diameter more than 2.0 mm during EVAR since June 2015. When four or more LA were patent, coil embolization for LA with inner diameter 2.0 mm or less was done. EVAR without aortic side branches coil embolization was performed for 59 patients prior to June 2015 (control group) and 79 patients underwent EVAR with coil embolization during EVAR (coil group). The success rate of coil embolization for IMA and LA was evaluated in coil group. The frequency of type 2 endoleak (T2EL), freedom from aneurysm sac expansion (5 mm or more) rate and the rate of the aneurysm sac shrinkage (10 mm or more) were compared between the coil and control groups. Additionally, multiple logistic regression analysis for all patients was conducted to analyze whether IMA patency and the number of patent lumbar artery at the end of EVAR were the risk factors of the aneurysm sac expansion of 5 mm or more. RESULTS: The success rate of IMA coil embolization was 96.4% and that of LA was 74.5%. Compared to the control group, the frequency of T2EL was significantly lower in coil group at 7 days (1.3% vs. 60.4%, P <0.0001) and at 6 months (2.1% vs 38.2%, P <0.0001) after EVAR. The freedom from aneurysm sac expansion rate was significantly better in the coil group at 5 years (100% in coil group and 65.2% in control group, P = 0.002). The rate of aneurysm sac shrinkage was significantly better in coil group (15.5% vs. 2.0% at 1 year, 42.8% vs. 6.3% at 2 years and 53.4% vs. 17.8% at 3 years, p = 0.0007). The risk of aneurysm sac expansion of 5 mm or more was estimated to be 11 times greater when the IMA was patent, and 4.9 times greater when 3 or more LAs were patent at the end of EVAR. CONCLUSION: When IMA was occluded and the number of patent LA became 2 or less by aortic side branch coil embolization during EVAR, favorable mid-term results were safely obtained and good long-term result could be expected with EVAR.

A systematic review on isolated coil embolization for pelvic venous reflux.

OBJECTIVE: Pelvic venous reflux (PVR) can present with symptoms such as chronic pelvic pain, dysmenorrhea, and dyspareunia, resulting in a decreased quality of life among those affected. Percutaneous coil embolization (CE) is a common intervention for PVR; however, the efficacy and safety of its use in isolation has yet to be reviewed. METHODS: The MEDLINE and EMBASE databases were systematically searched from 1990 to July 20, 2020, for studies reporting on adult patients undergoing isolated CE for PVR. Articles not in English, case reports, studies reporting on pediatric patients, and studies not performing isolated CE were excluded. Search, review, and data extraction were performed by two independent reviewers (S.S. and M.T.). Changes in pain before and after CE was evaluated through a pooled analysis of visual analogue scale scores in seven studies. RESULTS: A total of 970 patients (range, 3-218, 100% female) undergoing isolated ovarian vein or mixed veins embolization from 20 studies were included. Pooled analysis revealed mean improvements of 5.47 points (95% CI, 4.77-6.16) on the visual analogue scale. Common symptoms such as urinary urgency and dyspareunia reported significant improvements of 78-100% and 60-89.5% respectively. Complications were rare, with coil migration (n = 19) being the most common. Recurrence rates differed based on the varying symptoms and studies, with recurrence in pain 1-2 years after CE ranging from 5.9-25%. Two randomized controlled trials revealed improved clinical outcomes with CE as compared with vascular plugs and hysterectomy. CONCLUSIONS: The current data suggests that isolated CE is technically effective and can result in clinical improvement among patients with PVR. However, further trials are required to ascertain its long-term effects.