Therapeutic embolization with detachable balloons. Physical factors influencing permanent occlusion

Pseudoaneurysm formation following transarterial embolization of traumatic carotid-cavernous fistula with detachable balloon: An institutional cohort long-term study

BACKGROUND

The goal of therapy for traumatic carotid-cavernous fistula (TCCF) is the elimination of fistula while maintaining patency of the parent artery. The treatment for TCCF has evolved from surgery to endovascular management using detachable balloons, coils, liquid embolic agents, covered stents, or flow-diverter stent through arterial or venous approaches. Despite the withdrawal of detachable balloons from the market in the United States since 2004, transarterial embolization with detachable balloons has currently remained the best initial treatment for TCCF in several countries. However, the pseudoaneurysm formation following transarterial detachable balloon embolization has rarely been observed in long-term follow-up.

AIM

To determine the occurrence and long-term follow-up of pseudoaneurysm after transarterial detachable balloon for TCCF.

METHODS

Between January 2009 and December 2019, 79 patients diagnosed with TCCF were treated using detachable latex balloons (GOLDBAL) of four sizes. Pseudoaneurysm sizes were stratified into five grades for analysis. Initial and follow-up assessments involved computed tomography angiography at 1 month, 6 month, 1 year, and longer intervals for significant cases. Clinical follow-ups occurred semi-annually for 2 years, then annually. Factors analyzed included sex, age, fistula size and location, and balloon size.

RESULTS

In our cohort of 79 patients treated for TCCF, pseudoaneurysms formed in 67.1%, with classifications ranging from grade 0 to grade 3; no grade 4 or giant pseudoaneurysms were observed. The majority of pseudoaneurysms did not progress in size, and some regressed spontaneously. Calcifications developed in most large pseudoaneurysms over 5-10 years. Parent artery occlusion occurred in 7.6% and recurrent fistulas in 16.5%. The primary risk factors for pseudoaneurysm formation were identified as the use of specific balloon sizes, with balloon SP and No. 6 significantly associated with its occurrence (P = 0.005 and P = 0.002, respectively), whereas sex, age, fistula size, location, and the number of balloons used were not significant predictors.

CONCLUSION

Pseudoaneurysm formation following detachable balloon embolization for TCCF is common, primarily influenced by the size of the balloon used. Despite this, all patients with pseudoaneurysms remained asymptomatic during long-term follow-up.

Liquid and Solid Embolic Agents in Gonadal Veins

Male varicocele and pelvic congestion syndrome (PCS) are common pathologies with high predominance in young patients, having a high impact on the quality of life and infertility. Lately, the use of different endovascular embolization techniques, with various embolizing agents, shows good technical results and clinical outcomes. With the aim of presenting the "state of the art" of endovascular techniques for the treatment of male varicocele and PCS, and to discuss the performance of the different embolic agents proposed, we conducted an extensive analysis of the relevant literature and we reported and discussed the results of original studies and previous meta-analyses, providing an updated guide on this topic to clinicians and interventional radiologists. We have also underlined the technical aspects for the benefit of those who approach this type of interventional treatment. Our review suggests promising results in both the endovascular embolic treatment of male varicocele and PCS; for varicocele, a success rate of between 70% and 100% and a recurrence rate of up to 16% is reported, while for PCS it has been found that technical success is achieved in almost all cases of endovascular treatment, with a highly variable recurrence rate based on reports. Complications are overall rather rare and are represented by periprocedural pain, migration of embolic media and vascular perforations: severe adverse events have been reported very rarely.

In vitro evaluation of the occlusive properties of latex-covered amplatzer vascular plugs for transrenal ureteral occlusion

PURPOSE

To evaluate the occlusive properties of latex-covered Amplatzer Vascular Plugs (AVPs) for transrenal ureteral occlusion in vitro.

MATERIALS AND METHODS

Latex-covered AVPs type I and II (diameter 8, 10, 12, 14, and 16 mm) were used as occlusive devices. Radial force of an AVP was measured using simulated ureteral diameters of 4 to 12 mm. Occlusive properties were examined in a silicone tube (inner diameter 6 mm) with measurement of drainage time of a 40 cm water column. In complete occlusion, the maximum pressure that the plug was able to withstand was determined at different temperature levels. Statistical analysis of drainage time was performed in a general linear model (GLM) and using correlation analyses. Explanted porcine ureters were used to simulate physiologic conditions. Pressure measurements were performed until leakage, plug dislocation, or rupture of the ureter occurred.

RESULTS

Radial force depended on AVP type, size, ureteral diameter, and temperature. The 16-mm AVP II showed the highest radial force of more than 5 N (ureteral diameter 4 mm, body temperature). All AVP I showed water leakage and plug dislocation. Drainage time of the AVP II depended significantly on plug size and temperature and correlated with radial force (r=0.731, P<0.001). In complete occlusion, water leakage occurred at 500 to 1000 cm H2O and dislocation between 500 to more than 2000 cm H2O. In porcine ureters, leakage occurred at room temperature between 19 to 93 cm H2O. At body temperature, all AVP II occluded the ureter completely.

CONCLUSION

Latex-covered AVP II (diameter 8-16 mm) can effectively occlude the ureter, especially considering remodeling of the nitinol at body temperature. Large plug diameters can exert enough radial force even in dilated ureters to allow for successful occlusion. Because deployment of a 16-mm latex-covered AVP II can be technically difficult, we advocate the use of 12- or 14-mm AVP II for transrenal ureteral occlusion. AVP Is are not suitable for ureteral occlusion.

Evaluation of manufacturing variability, diffusion of filling solutions, and long-term maintenance of occlusion in silicone hydraulic occluders

OBJECTIVE

To evaluate manufacturing variability, diffusion of filling solutions, and maintenance of occlusion over time in 3 sizes of silicone hydraulic occluders (HOs).

SAMPLE POPULATION

2-, 5-, and 20-mm HOs (HO2, HO5, and HO20, respectively).

PROCEDURES

Manufacturing variability was analyzed by comparing variation in internal luminal areas and filling volumes within each size group. Occluders were filled to 100% occlusion with air (n = 4), saline (0.9% NaCl) solution (4), or sodium hyaluronate (4) and submerged in simulated body fluid. Changes in luminal area and weight were recorded for 133 days to evaluate maintenance of occlusion.

RESULTS

Considerable variability in uninflated luminal area and fill volumes was observed among the 3 sizes of HOs. Loss of occlusion developed in the first 12 hours in all air-filled HOs. Fluid-filled occluders were reliable in maintenance of occlusion after 133 days (99.99% for HO20, 99.59% for HO5, and 90.40% for HO2), although diffusion of saline solution and hyaluronate from all HOs was confirmed by detection of significant decreases in weight over time. There was no significant difference in weight loss between HOs filled with saline solution and HOs filled with sodium hyaluronate.

CONCLUSIONS AND CLINICAL RELEVANCE

Saline solution or sodium hyaluronate may be used as a filling solution in the HOs tested. Maintenance of occlusion was best in the larger sizes. Saline solution or sodium hyaluronate should be used in future clinical investigations of HOs. Retrograde filling to remove air should be used when filling HOs with fluid.

Embolotherapy of pulmonary arteriovenous malformations with detachable balloons: long-term durability and efficacy

PURPOSE

To determine long-term durability and efficacy of pulmonary arteriovenous malformation (PAVM) embolotherapy using detachable gold valve latex (GVB) and silicone balloons (DSB).

MATERIALS AND METHODS

Eighty-two patients were treated with either GVBs or DSBs between 1991 and 1996. Complete follow-up, consisting of chest radiography or high-resolution chest computed tomography, was obtained in each patient between 1996 and 1998. The PAVM was considered cured if the aneurysmal portion was involuted with or without a small residual scar.

RESULTS

Eighty-two of the 85 DSBs (96%) were inflated 2-4 years later, and none of the 56 GVBs remained inflated 1-3 years after placement. Despite early deflation of the GVB (91% at 1 month), only one PAVM persisted in both groups (DSB and GVB). Clinical and radiographic involution of the PAVMs was complete in all patients except one, who was easily re-treated. No migration of DSBs or GVBs to the systemic circulation occurred.

CONCLUSIONS

DSBs and GVBs provide immediate cross-sectional occlusion of PAVM and are equally effective in "curing" the PAVM. The DSBs remain inflated 2-4 years after placement provided isoosmotic contrast material is used to inflate them and volume recommendations are adhered to. No early or late migration of the DSB or GVB occurs, provided they are securely placed.

Endovascular treatment of vascular injuries

The endovascular management of hemodynamically stable patients with traumatic vascular lesions is an appealing concept. In principle, many of the injuries detected at the time of diagnostic angiography can be treated at the same setting. Moreover, lesions that occur at the base of the skull or at infraclavicular and pelvic locations pose far less difficulty when managed by transcatheter techniques than by traditional surgical exposure. Even among more accessible injuries, standard surgical dissection is often complicated by the presence of hematoma or pseudoaneurysm, which causes obliteration of natural tissue planes, or arteriovenous fistulas that may complicate dissection because of associated regional venous hypertension. Thus, endovascular approaches may provide easier access to the target lesion, limit the morbidity often associated with surgical exploration, and reduce transfusion requirements. Nonetheless, the long-term consequence of placing an intravascular foreign body in a young patient is undefined, and the potential risk for a device infection cannot be ignored. Definitive answers to these issues await the outcome of longitudinal follow-up studies. Until that time, a prudent approach in the use of this new technology is appropriate.

Pulmonary arteriovenous malformations: diagnosis and transcatheter embolotherapy

The recent long-term studies from England, France, and the Netherlands, as well as our own, indicate that transcatheter embolotherapy is definitive treatment for PAVM. More recently, Puskas et al have questioned transcatheter embolotherapy as a primary treatment for patients with PAVM (4,56). Their opinion was based on two recurrences among five patients treated with transcatheter embolotherapy. It is not clear why one of the late recurrences in the series by Puskas et al happened, and the other recurrence could have been dut to early deflation of the balloon. Nevertheless, we believe that the collective experience in the larger series reporting on transcatheter embolotherapy of PAVM supports the use of embolotherapy as a primary modality of treatment. Because many patients have bilateral pulmonary malformations and many pulmonary malformations will grow with time, repeated surgical intervention is not ideal therapy. The recurrence rate of 8% reported by Remy et al using coils, and 2% reported by Pollak et al using balloons and coils supports our contention that transcatheter embolotherapy is durable and should be the initial treatment. Also, recurrences are easily retreated by transcatheter embolotherapy with durable results (54). We favor detachable balloons over coils for occluding PAVMs because immediate cross-sectional occlusion of the segmental artery is obtained in a position that preserves the most normal branches. The necessity for repeated introduction of coils, when using the coil method, contributes to longer procedure times with an increased risk of air introduction and, in our experience, a greater risk of postprocedure pleurisy. At the same time, we appreciate that approximately 70% of PAVMs can be occluded equally well with balloons or coils. We also believe that coils have unique advantages over balloons in specific anatomic situations including oversized arteries (where coils are the only option) and for occlusion of the aneurysm of a PAVM. As with all forms of embolotherapy, the interventionalist is best served by having more than one option of treatment, which for PAVM includes both balloons and coils. In summary, PAVMs are effectively managed by means of transcatheter embolotherapy. This therapy has been demonstrated to be safe and durable. Careful technique with modifications depending on the angioarchitecture of the PAVM is required. Patients with PAVMs require follow-up at 1 month and 1 year. While observations documenting serial growth of small PAVMs are somewhat limited, there is published evidence to support their growth with time (35,36). Because of these reports and our unpublished observations, we believe that patients with treated PAVM need long-term follow-up every 5 years to detect growth of small PAVMs that will ultimately reach a size where they may cause paradoxical embolization and stroke (1).

Arterial embolization in the treatment of Curling's ulcer bleeding in a burn patient

Curling's ulcer bleeding is a well-known life-threatening complication of the severely thermally injured patient. This report describes a successful left gastric artery embolization in a 70 per cent total body area burn patient with severe gastric bleeding. We discuss the various non-surgical invasive modalities for treating such patients, and emphasize the advantages of arterial embolization over surgery.

Arteriovenous fistula simulating arteriovenous malformation

A 36-year-old man was thought (for 20 years) to have an arteriovenous malformation that could not be excised. Repeated ligations of proximal arterial supply to the vascular lesion were only transiently beneficial and may have caused a delay in correct diagnosis because of impaired angioaccess. Once it was discovered that he had an arteriovenous fistula--probably caused by a tonsillectomy at age 6--it was possible to occlude the fistula with detachable balloons. The mass and his headaches subsequently resolved. AV fistulas are caused by trauma. Growth of AVMs is often stimulated by trauma. Both lesions have pulsatile masses associated with overlying bruits. The differential diagnosis can usually be made by arteriography, since AV fistulas are acquired lesions with a single communication between an artery and a vein, whereas AVMs are congenital lesions with multiple, large arterial feeding vessels and numerous arteriovenous communications. Proper diagnosis is important, since AVMs are aggressive lesions that tend to regrow if not completely excised. AV fistulas will be cured if the single arteriovenous communication can be obliterated. Proper treatment for AV fistula is obliteration of the single arteriovenous communication, operatively or with occlusive balloons; treatment of AVMs--when possible--is excision of the entire mass, combined (on occasion) with preoperative embolization of the tumor mass. This case report emphasizes the importance of accuracy in the differential diagnosis between arteriovenous malformations and arteriovenous fistulas; moreover, it demonstrates both the ineffectiveness and deleterious consequences of proximal arterial ligation, since collateral development is enhanced and angiographic access is compromised.

Interventional cardiac catheterization in congenital heart disease

Cardiac catheterization has proved its value as a major tool in the diagnosis of congenital cardiac defects. The advent of non-invasive imaging of various sorts has altered the role of diagnostic catheterization. Within the past two decades cardiac catheter instruments to provide therapy have been applied to many lesions. Improvements in design and methods will expand the use of therapeutic catheterization. It is inevitable that better results will be obtained for those defects currently being treated that way, and that the method will be applied to other conditions.

Coil embolization of congenital thoracic vascular anomalies in infants and children

When significant thoracic vascular anomalies occur in children, they may present surgical difficulties making operative management undesirable. The recent development of a new, accurate coil-delivery system has enabled us to embolize 17 vessels in five children by passing Gianturco steel coils coated with thrombogenic Dacron strands through No. 5 or 6F end-hole catheters suitable for infants. Coils of 0.038 inch packed diameter were fed through the catheter lumen by a flexible guidewire emerging as 3, 5, or 8 mm diameter loose coils. Fifteen of 17 vessels were successfully occluded. No complications or errors in placement of coils occurred. Four of five children clearly benefitted from the procedure. One died in spite of partial occlusion. Coil embolization can be performed accurately and safely even in small infants with a high rate of successful occlusion and may prove to be a valuable adjunct to operative management.

Splenectomy after angiographic embolization of the splenic artery in patients with massive splenomegaly and severe thrombocytopenia, in juvenile subacute myelomonocytic leukemia

Splenectomy for massive splenomegaly in thrombocytopenic patients refractory to platelet transfusions carries increased surgical risks. Blocking of the splenic artery may reduce the size of the organ, prolong the survival of transfused platelets, and reduce the surgical complications. We describe four cases of extreme splenomegaly and thrombocytopenia where successful splenectomy was carried out after angiographic embolization of the splenic artery in children with juvenile chronic myelogenous leukemia. Significant improvement was observed in platelet counts and in the survival of platelets after transfusions in three of the patients. There was a concomitant decrease in transfusion requirements. Isoimmunization prevented prolonged platelet survival in the fourth case. We recommend earlier splenectomy in these patients to reduce transfusion requirements and delay the onset of poor platelet survival after transfusions.

Balloon embolization to occlude a Blalock-Taussig shunt

Balloon embolization was used to successfully occlude a large residual Blalock-Taussig shunt. The use of an "upstream" nondetachable balloon catheter to reduce flow and turbulence during final positioning of the detachable balloon may have made the technique safer and more precise.

Deflation of metrizamide-filled balloon used to occlude a carotid-cavernous fistula. Case report

A carotid-cavernous fistula was occluded by a detachable latex balloon. Because of technical problems, the contrast-filled balloon was left in a precarious position in the ostium of the fistula. Premature deflation of the balloon would have resulted in intra-arterial migration of the device. Approximately 1 week is required for the balloon to become secured in place by fibrous attachment to the vascular wall. For success, if the ligature is adequate, a detachable Debrun balloon should remain inflated for this period of time. The deflation process was monitored radiographically in this patient. The balloon remained inflated for at least 2 weeks. A short summary of the experience with deflation of various contrast-containing balloon devices in the treatment of carotid-cavernous fistulas is given. Metrizamide may be the best contrast agent for use in these devices.

Complications of detachable balloon catheter technique in the treatment of traumatic intracranial arteriovenous fistulas

As carotid-cavernous sinus fistulas (CCSF) are not life-threatening, therapeutic attempts should carry a very low morbidity and mortality. The authors believe that utilization of detachable balloons is the treatment of choice for CCSF, although this procedure is not without risk. Seven patients have been treated for high-flow traumatic intracranial fistulas over the past 2 years with detachable balloons using a coaxial catheter system. This paper presents several complications that have been encountered during this experience, and advances suggestions regarding treatment and avoidance of potential complications.

Renal arteriovenous fistula--angiographic and sonographic correlation

We report a case of a markedly enlarged inferior vena cava and a cystic structure simulating a hydronephrotic kidney in the clinical setting of hypertension with cardiomegaly, congestive heart failure and a flank bruit. Ultrasonographic findings with the aid of angiography were highly suggestive of a renal arteriovenous fistula or malformation.

Transcatheter hemostasis in the genitourinary tract

Transcatheter hemostasis is applicable in a large variety of causes of genitourinary hemorrhage. The method is particularly useful in the management of trauma since temporary occlusion of the bleeding vessel usually produces cessation of hemorrhage without significant sacrifice of additional parenchyma. Control of arteriovenous fistulas requires an assessment of flow characteristics and careful tailoring of catheter and embolization technique; large emboli or glue is frequently required for occlusion of large fistulas, whereas small ones can be treated with Ivalon. Hemorrhage from renal or pelvic neoplasm is also effectively managed by transcatheter therapy.

Therapeutic embolization with detachable balloons

In our first 18 months' clinical experience with embolization in the chest and abdomen using detachable balloons, successful results were obtained in 34 of 38 patients. One and 2-mm detachable silicone balloons, which can occlude vessels 4--8 mm in diameter, were employed. Prolonged balloon inflation was routinely achieved using iso-osmotic iodipamide meglumine as the filler and limiting inflation volumes to experimentally determined maximums. Improvements in introducer catheter design simplified delivery of the balloon into a variety of circulations. Detachable balloons are not suitable for all embolization purposes, and they are frequently used in conjunction with other agents. When used properly, balloons produce a permanent occlusion that is extremely selective and potentially reversible up to a certain point in the procedure. The balloon technique enables the angiographer to occlude vessels at distances of 2--10 mm beyond the introducer catheter, thus avoiding the need for subselective catheterization and minimizing the dangers of inadvertent embolization.