Endoluminal occlusion devices: technology update

In Vitro Head-to-Head Comparison of Flow Reduction between Fibered and Non-Fibered Pushable Coils

PURPOSE

To compare the embolization effects of a non-fibered pushable coil with a conventional fibered pushable coil in an in vitro bench-top experiment.

MATERIALS AND METHODS

A simplified vascular phantom with 4 channels (1 for the non-fibered coil, 1 for the fibered coil, and 2 for continuous circuit flow) was used. A single coil of the longest length was inserted to evaluate the effect of single-coil embolization, and 3 consecutive coils were inserted to assess the effect of multiple-coil embolization. Post-embolization angiography was performed to obtain flow variables (time to peak [TTP], relative peak intensity [rPI], and angiographic flow reduction score [AFRS]) from time density curves. The packing densities of the two coil types were calculated, and the AFRS of each channel was determined by dividing the TTP by the rPI.

RESULTS

When inserting a single coil, the conventional fibered coil demonstrated better flow reduction, as indicated by a higher AFRS (25.6 vs. 17.4, P=0.034). However, the non-fibered coil exhibited a significantly higher packing density (12.9 vs. 2.4, P=0.001). Similar trends were observed with multiple coils.

CONCLUSION

The conventional fibered pushable coil showed better flow reduction efficiency, while the non-fibered pushable coil had a higher packing density, likely due to the flexibility of the coil loops. A better understanding of the distinct characteristics of different pushable coils can enhance the outcomes of various vascular embolization.

Embolization in Pediatric Patients: A Comprehensive Review of Indications, Procedures, and Clinical Outcomes

Embolization in pediatric patients encompasses a large spectrum of indications, ranging from the elective treatment of congenital diseases of the cardiovascular system to the urgent management of acute hemorrhagic conditions. In particular, the endovascular treatment of central and peripheral vascular malformations and hypervascular tumors represents a wide chapter for both congenital and acquired situations. Thanks to the progressive availability of low-profile endovascular devices and new embolic materials, the mini-invasive approach has gradually overtaken surgery. In this review, the main embolization procedures will be illustrated and discussed, with a focus on clinical indications and expected outcomes. The most recent mini-invasive techniques will be described, with hints on the cutting-edge devices and embolic materials.

The management of paravalvular leaks post aortic valve replacement

BACKGROUND

Paravalvular leak (PVL) is uncommon but can lead to severe complications after surgical or transcatheter aortic valve implantation. Conditions associated with PVLs such as heart failure, hemolysis, and infective endocarditis can lead to catastrophic results if not treated promptly; the therapeutic goals differ according to the presentation. It is vital that PVLs are diagnosed early using various imaging modalities. Different approaches have been studied in managing PVLs; there is an increased interest in the transcatheter aortic valve closure procedure as it is minimally invasive and decreases the occurrence of further reinterventions.

AIM

To discuss the classification of PVLs, diagnostic approaches, and available management options.

METHOD

A literature review was performed using 28 studies.

RESULTS

This review evaluated the relationship between the time of diagnosis, management of PVL and the resulting outcomes.

DISCUSSION

Patients with PVL should be assessed through a multidisciplinary team approach and a patient-selective plan should be in place.

CONCLUSION

Open surgical intervention is reserved for complex cases where minimally invasive techniques cannot be utilized.

Incidental Finding of an Asymptomatic Migrated Coil to the Right Ventricle Following Pelvic Vein Embolisation

Pelvic vein embolisation (PVE) with metallic coils is an effective treatment for pelvic venous congestion. The migration of coils following the procedure has been well-reported; however, the most effective approach to management is still unclear. In the present case, the authors describe the delayed identification of a migrated coil to the right ventricle following an ovarian vein embolisation. The patient presented to the emergency department with chest pain and subsequent radiology identified a coil in the right ventricle. This was found to be present on previous radiology, but had not been reported on. The position of the coil had remained stable and therefore was deemed an unlikely cause for the chest pain. The coil was managed conservatively. This demonstrates how asymptomatic coil migration may go undetected and thus the migration rates in the literature may be underreported. Post-PVE screening to assess for migration could improve the accuracy of complication rates and prevent delayed complications associated with migrated coils.

A novel method of inducing thrombosis in target arteries using coronary stents for therapeutic occlusion

OBJECTIVES

Peripheral artery embolizations are often required for therapeutic purposes. The therapeutic embolizations are usually performed using embolization particles and coils. These procedures are also associated with complications. Coils and their delivery cables, and the expertise are not always available in all catheterization centers. Hence, a novel, simple controlled technique for arterial closure would be useful in emergency settings.

RESULTS

Following is a report of seven cases where embolization was performed successfully on an emergency basis after stenting using coronary stents for better closure of the target artery. Six patients underwent bronchial artery embolization for recurrent massive hemoptysis, and one another patient had pseudoaneurysm following percutaneous nephrolithotomy, and presented with hematuria and persistent and increasing blood discharge in drainage catheter. The stents were deployed in the target artery using 6F Judkin's diagnostic catheter over the 014 wires, which are easily available in all cardiac catheterization laboratories. This is a novel method to establish a metal platform inside the target arteries using coronary stents for better closure of the target arteries in combination with embolization techniques. The procedures were performed as lifesaving measures when small coils and the delivery cables were not available at the time of the procedures.

Contemporary Role of Embolization of Solid Organ and Pelvic Injuries in Polytrauma Patients

Abdominopelvic trauma (APT) remains a leading cause of morbidity and mortality in the 15- to 44-year-old age group in the Western World. It can be life-threatening as abdominopelvic organs, specifically those in the retroperitoneal space, can bleed profusely. APT is divided into blunt and penetrating types. While surgery is notably considered as a definitive solution for bleeding control, it is not always the optimum treatment for the stabilization of a polytrauma patient. Over the past decades, there has been a shift toward more sophisticated strategies, such as non-operative management of abdominopelvic vascular trauma for haemodynamically stable patients. Angiographic embolization for bleeding control following blunt and/or penetrating intra- and retroperitoneal injuries has proven to be safe and effective. Embolization can achieve hemostasis and salvage organs without the morbidity of surgery, and the development and refinement of embolization techniques has widened the indications for non-operative treatment in solid organ injury. Moreover, advances in computed tomography provided more efficient scanning times with improved image quality. While surgery is still usually recommended for patients with penetrating injuries, non-operative management can be effectively used as well as an alternative treatment. We review indications, technical considerations, efficacy, and complication rates of angiographic embolization in APT.

Managing Complications Following Nephron-Sparing Procedures for Renal Masses

Small renal malignancies are commonly treated with nephron-sparing procedures including partial nephrectomy and percutaneous ablation. Although these procedures offer faster patient recovery and preserve renal function, a variety of complications can occur. Here, we review vascular and nonvascular complications associated with nephron-sparing renal mass treatments and discuss options for minimally invasive image-guided management.

Nonoperative Management of Acute Upper Limb Ischemia

BACKGROUND

Acute upper limb ischemia (AULI) is an uncommon emergency warranting immediate evaluation and treatment. The role of nonsurgical therapies including endovascular techniques, thrombolytics, and anticoagulation remains undefined. The authors systematically reviewed the current literature on the nonsurgical treatment of acute ischemia of the upper extremity.

METHODS

A PubMed and Embase search was conducted, and articles were screened using predetermined criteria. Data collected included patient demographics, cause of upper limb ischemia, type of nonsurgical treatment used, treatment outcomes, and complications. Patients were divided into 4 treatment groups: catheter embolectomy, catheter-directed thrombolysis, endovascular stenting, and anticoagulation/medical therapy alone.

RESULTS

Twenty-three retrospective studies met the search criteria. Of 1326 reported occlusions, 92% (1221) were attributed to thromboembolic disease. The second most common cause was iatrogenic (1.5%). Overall limb salvage rates were excellent with catheter embolectomy (862 of 882 cases, 97.7%) and catheter-directed thrombolysis (110 of 114 cases, 96.5%). Limb salvage rates were also high with anticoagulation/medical therapy (158 of 165 cases, 95.8%), but poor functional outcomes were more often reported.

CONCLUSIONS

High-quality evidence to guide the nonsurgical treatment of AULI is lacking. Retrospective studies support the utility of catheter-based embolectomy and thrombolysis for distal ischemia. Whether a surgical or nonsurgical approach is taken, anticoagulation therapy remains a mainstay of both treatment and prevention of AULI. Because AULI patients often have underlying cardiac and/or systemic disease, a multidisciplinary approach is essential to minimize complications and prevent future occurrences.