Posttraumatic carotid-cavernous sinus fistula

BACKGROUND AND OBJECTIVES

Posttraumatic carotid-cavernous sinus fistula is a rare complication of maxillofacial trauma and is seldom discussed in the literature. Motor vehicle accidents, falls, and other crush injuries contribute to the incidence of basilar skull fractures and the formation of fistulae. When injuries occur in the vessel wall, the carotid artery has the potential to fill the low-pressure cavernous sinus. The symptoms include chemosis, proptosis, pulsating exophthalmos, diplopia, ophthalmoplegia, orbital pain, audible bruits, and blindness.

METHODS AND MATERIALS

The conventional treatments include carotid ligation and embolization. These techniques have often proved to be ineffective. A new method--the occlusive balloon technique--has been developed and is described in this article. A clinical case is used to illustrate the procedure.

RESULTS AND/OR CONCLUSIONS

Utilization of balloon catheters provides a minimally invasive technique to treat patients, without significant morbidity or mortality. The procedure is found to be successful and predictable.

The learning curve for coil embolization of unruptured intracranial aneurysms

BACKGROUND AND PURPOSE

Several studies have shown that procedural outcomes are better at high-volume institutions, possibly due to greater physician experience (learning) or practice (repetition). Our purpose was to determine whether outcomes for coil embolization improved with the experience of the practitioner, after adjusting for the perceived risk of treatment.

METHODS

We identified all unruptured aneurysms treated with coil embolization at our institution from 1990 through 1997. A clinical nurse specialist abstracted the characteristics from cases that met the entry criteria. Two neurologists independently determined the complications by using definitions established a priori. The influence of experience of the treating-physician on complications was evaluated with univariate and multivariable logistic regression analyses.

RESULTS

Sixteen complications occurred in 94 patients (17%) treated with coil embolization. Complications occurred in 53% of the first five cases that each of three physicians treated, and in 10% of later cases (P <.001). After an adjustment for all other predictors, including physician assessment of the risk of the procedure, the odds of a complication decreased with increasing physician experience (odds ratio, 0.69 for every five cases treated; 95% confidence interval: 0.50, 0.96; P=.03).

CONCLUSION

The risk of complications with coil embolization of unruptured aneurysms appears to decrease dramatically with physician experience. Because the physicians in this study were highly experienced in other endovascular techniques at study onset, the rate of learning may not be generalizable to other centers.

Endovascular management of aneurysm and carotid-cavernous fistulae from gunshot wounds to the skull base and oropharynx

The clinician must be aware of the potential for vascular injury that can result from gunshot wounds to the skull base and oropharynx. These lesions can be life-threatening or can result in irreversible neurologic defects. The goal is early diagnosis and efficient appropriate treatment. Endovascular therapy has been proven to be of great benefit for the treatment of traumatic aneurysms and carotid-cavernous fistulae. Utilizing either a reconstructive or a deconstructive approach, the traumatic lesions can be treated without the morbidity inherent to surgery of the skull base or cavernous sinus. This article discusses the authors' experience with endovascular treatment, explaining in detail the reconstructive and deconstructive approaches and providing clinical examples of the treatment of pseudoaneurysms and carotid-cavernous fistulae.

Evaluation of the stability of aneurysms after embolization using detachable coils: correlation between stability of aneurysms and embolized volume of aneurysms

BACKGROUND AND PURPOSE

The long-term outcome of aneurysmal coil embolization has not been determined. We retrospectively analyzed the results of our cases treated with detachable coils and evaluated the long-term stability of embolized aneurysms.

METHODS

This study involved 100 aneurysms in 93 patients who underwent follow-up angiography > or = 3 months after initial treatment between December 1993 and December 1999. The percentage of the coil volume occupying the aneurysm lumen (embolized volume) was used as an index to evaluate the stability of embolized aneurysms. The reliability of the embolized volume was also evaluated by comparing angiographic percentage occlusion.

RESULTS

Follow-up angiographic assessment was conducted 12 +/- 8.5 months after initial treatment. Angiographic evaluation of percentage occlusion at initial treatment did not always predict long-term stability of embolized aneurysms. Of 49 aneurysms judged as being totally occluded at initial treatment, 44 remained unchanged and five showed recanalization. The embolized volume of unchanged aneurysms was 30.8 +/- 10.2%, and that of recanalized aneurysms was 19.9 +/- 10.6%. There was a significant difference between these two groups (P=.03). Of 29 subtotally occluded aneurysms, nine had further thrombosis (embolized volume = 31.8 +/- 12.7%), nine remained unchanged (embolized volume = 23.2 +/- 10.3%), and 11 had recanalization (embolized volume = 14.1 +/- 6.1%). The mean embolized volume of 11 recanalized aneurysms was significantly lower than in the thrombosed group and the unchanged group (P=.002 and P <.001, respectively). Large aneurysms tended to have recanalization more frequently (59%) than did small aneurysms (15%).

CONCLUSION

There is a significant correlation between embolized volume and stability of embolized aneurysms. Embolized volume is a more objective index than is subjectively angiographic percentage occlusion. In addition to angiographic assessment, measurement of embolized volume could be useful to predict angiographic changes of aneurysms.

Carotid-cavernous sinus fistulae in craniofacial trauma: classification and treatment

Carotid-cavernous sinus fistulae (CCF) represent pathological communications between the intracavernous internal carotid artery and the cavernous venous sinus. Although trauma is the most common cause of high flow carotid cavernous fistulae, they are relatively uncommon in patients sustaining craniofacial trauma. Nevertheless, CCF require early diagnosis and rapid and effective treatment in order to prevent severe and significant morbidity. Clinical presentation may include pulsatile proptosis, ocular and orbital erythema, chemosis, diplopia, headaches, and visual loss. Cerebral angiography is currently the definitive diagnostic study. Obliteration of the fistula by endovascular techniques is the current mainstay treatment, and direct surgery is reserved for cases that have failed endovascular therapy. This article reviews clinical features, pertinent anatomy, and therapeutic approaches to carotid-cavernous sinus fistulae.

Transvascular coil hooking procedure to retrieve an unraveled Guglielmi detachable coil: technical note

OBJECTIVE

A patient with an anterior communicating artery aneurysm was treated by use of endovascular coiling, and a Guglielmi detachable coil (Boston Scientific/Target, Fremont, CA) fractured distal to its connection to the delivering catheter. The unraveled coil floated out from the aneurysm to extend into the bifurcation of the left middle cerebral artery. We describe the microsurgical procedure used to retrieve the coil after an endovascular approach failed.

METHODS

The left anterior cerebral artery was punctured just below the aneurysm neck, and a titanium microhook was introduced to anchor the coil and pull it out. Slight traction was exerted before sectioning the coil to avoid protrusion of the stump into the parent vessel.

RESULTS

The unraveled coil was removed in totality without permanent morbidity.

CONCLUSION

This report describes the case of a rare complication of coil embolization treated with a minimal transarterial coil hooking procedure.

[Interventional occlusion of interatrial communication after modified Fontan operation]

After modified Fontan operations various communications between the systemic and pulmonary venous returns may cause persistent or increasing postoperative cyanosis. Interventional closure of these right-to-left shunts may be necessary to eliminate hypoxemia and to reduce the risk of paradoxical embolic complications.

PATIENTS AND METHODS

Eighteen patients with a mean age of 5.6 +/- 4.1 (2.5-17.5) years underwent interventional closure of a right-to-left shunt 17.4 +/- 15.8 (3-60) months after a modified Fontan operation. After test balloon occlusion fenestrations were closed in 13 patients using an Amplatzer Septal occluder (n = 7), a Rashkind PDA occluder (n = 3), a CardioSeal umbrella (n = 1) and detachable coils (n = 2). Residual leaks at the suture lines between the interatrial patch and the right atrial wall were closed using detachable coils and a Rashkind PDA occluder in 2 and 1 patients, respectively. In 3 patients intracardiac venous collateral channels were closed by means of detachable coils.

RESULTS

The mean aortic oxygen saturation increased from 85 +/- 4.5 (70-89)% to 91.4 +/- 2.8 (83-95)% (p < 0.001) breathing room air and the mean tunnel pressure rose from 10.7 +/- 1.8 (6-14) mmHg to 12.1 +/- 2.4 (6-16) mmHg (p < 0.001). Calculated Qs decreased from 5.15 +/- 2.1 (2.1-11.3) l/min/m2 to 3.6 +/- 1.0 (1.8-5.6) l/min/m2 (p < 0.001). Mixed venous saturation (66.4 +/- 7.4% vs 65 +/- 7%) and mean systemic arterial pressure (73 +/- 8 mmHg vs 73 +/- 9 mmHg) remained unchanged. In one patient an additional leak of the tunnel could not be closed because of an increase to more than 18 mmHg of the mean pressure in the lateral tunnel during balloon test occlusion. In 2 patients residual leaks after umbrella and coil occlusion of a fenestration and an additional venous collateral channel were closed by means of coils after 16 and 21 months, respectively. At a follow-up of 42 +/- 23 (7-99) months, mean oxygen saturation measured by pulse oxymetry was 93 +/- 2 (90-97)%. In 2 patients color-coded Doppler echocardiography revealed a minimal residual right-to-left shunt. In 2 patients contrast echocardiography demonstrated the additional presence of intrapulmonary fistulas. All patients remained free from device migration, thromboembolic events and hemolysis.

CONCLUSION

After modified Fontan operations various right-to-left shunts between the systemic and pulmonary venous returns can be successfully closed using umbrella devices or coils to eliminate cyanosis and to reduce the risk of paradoxical embolism.

Recurrence of dural arteriovenous fistula in another location after selective transvenous coil embolization: report of two cases

Two cases of a second dural arteriovenous fistula (DAVF), both developing in different locations after selective transvenous embolization of the first DAVF, are presented. One recurrent DAVF developed on the sigmoid sinus 5 months after transvenous embolization of a DAVF in the paratransverse sinus channel, and the other recurrence developed around the jugular bulb 5 months after transvenous embolization of a cavernous DAVF. The former was obliterated by a second embolization, and the latter disappeared spontaneously at 20 months.

Interaction of vascular smooth muscle cells with collagen-impregnated embolization coils studied with a novel quantitative in vitro model

BACKGROUND AND PURPOSE

Modifications of aneurysm occlusion devices and other biologically active molecules may reduce the risk of recanalization by promoting vascular cell migration, adhesion, and proliferation. Our purpose was to apply in vitro methods in the qualitative and quantitative analysis of vascular smooth muscle cell (VSMC) interactions with collagen-impregnated microcoils.

METHODS

The adhesion of rat aortic VSMCs to collagen fiber bundles (CFBs), nitinol coils, and collagen-impregnated nitinol coils (CINCs) was examined by using an assay consisting of monopulse exposure to increasing concentrations of rat aortic VSMCs. Exposed devices were washed and examined by using confocal fluorescence microscopy. Adhesion coefficients, which quantitatively express the cell-binding quality of a surface, were determined by using a mathematical model for cell-device interactions.

RESULTS

VSMCs, attached to devices, spread out and extended cytoplasmic projections over the contact surface. Cell distribution was random on CFBs and within interloop troughs on nitinol coils. On collagen-impregnated coils, VSMCs were selectively concentrated on the collagen between coil loops. The average adhesion coefficient was 25.0 for CFBs, 8.5 for CINCs (250-microm pitch), and 6.5 for nitinol coils. Adhesion coefficient differences for the three devices were significant (P =.044).

CONCLUSION

The monopulse exposure assay is a simple and reproducible in vitro test that provides qualitative information about the morphology and topography of cell-device contacts and permits quantitative measurement of the intrinsic cell-binding quality of the test device. VSMCs exposed to collagen-impregnated microcoils selectively attach to collagen. Collagen enhances the rate of VSMC adhesion to embolic devices, and the degree of enhancement correlates with the surface area constituted by collagen.

Influence of neutron irradiation on holmium acetylacetonate loaded poly(L-lactic acid) microspheres

Holmium-loaded microspheres are useful systems in radio-embolization therapy of liver metastases. For administration to a patient, the holmium-loaded microspheres have to be irradiated in a nuclear reactor to become radioactive. In this paper. the influence of neutron irradiation on poly(L-lactic acid) (PLLA) microspheres and films, with or without holmium acetylacetonate (HoAcAc), is investigated, in particular using differential scanning calorimetry (MDSC), scanning electron microscopy, gel permeation chromatography (GPC), infrared spectroscopy, and X-ray diffraction. After irradiation of the microspheres, only minor surface changes were seen using scanning electron microscopy, and the holmium complex remained immobilized in the polymer matrix as reflected by a relatively small release of this complex. GPC and MDSC measurements showed a decrease in molecular weight and crystallinity of the PLLA, respectively, which can be ascribed to radiation induced chain scission. Irradiation of the HoAcAc loaded PLLA matrices resulted in evaporation of the non-coordinated and one coordinated water molecule of the HoAcAc complex, as evidenced by MDSC and X-ray diffraction analysis. Infrared spectroscopy indicated that some degradation of the acetylacetonate anion occurred after irradiation. Although some radiation induced damage of both the PLLA matrix and the embedded HoAcAc-complex occurs, the microspheres retain their favourable properties (no marginal release of Ho, preservation of the microsphere size), which make these systems interesting candidates for the treatment of tumours by radio-embolization.

Cellular responses of bioabsorbable polymeric material and Guglielmi detachable coil in experimental aneurysms

BACKGROUND AND PURPOSE

Acceleration of healing mechanisms is a promising approach to improve current limitations of endovascular aneurysm therapy with the use of platinum coils. We evaluated a new endovascular therapeutic, bioabsorbable polymeric material (BPM), which may promote cellular reaction in the aneurysms.

METHODS

Four different concentrations of lactide/glycolic acid copolymer [poly(D-L-lactic-co-glycolic acid)] (PLGA), 85/15, 75/25, 65/35, and 50/50, were used as BPMs. Sixteen experimental aneurysms were created in 8 swine. Eight-millimeter-long spiral-shaped BPMs were surgically implanted in the aneurysms without tight packing (n=3 for each BPM). Guglielmi detachable coils (GDCs) were used as control (n=4). The animals were killed 14 days after embolization, and angiographic, histological, and immunohistochemical analyses were performed.

RESULTS

Despite loose packing of aneurysms with BPMs, faster BPMs such as 50/50 or 65/35 PLGA demonstrated more mature collagen formation and fibrosis in the sac and neck of the aneurysm. One aneurysm treated with 65/35 PLGA, 1 treated with 75/25 PLGA, and all 3 treated with 85/15 PLGA showed a neck remnant on angiography. There was a linear relationship between collagen levels and polymer degradation properties (r=-0.9513).

CONCLUSIONS

This preliminary animal study indicates that acceleration of aneurysm healing with the use of BPM is feasible. This concept can be applied to decrease and perhaps prevent aneurysmal recanalization after endovascular treatment of cerebral aneurysms.

A technique of GDC embolization for deeply bilobulated aneurysms

The endovascular occlusion of deeply bilobulated aneurysms is a technical challenge. Recently, we successfully treated three patients with deeply bilobulated aneurysms by using Guglielmi detachable coils. The embolization technique was conventional, but it required several special technical considerations. In this report, we describe the technique of coil embolization of deeply bilobulated aneurysms.

Photothermal properties of shape memory polymer micro-actuators for treating stroke

BACKGROUND AND OBJECTIVES

In this paper the photothermal engineering issues of novel shape memory polymer (SMP) microactuators for treating stroke are presented. The engineering issues for using lasers to heat and subsequently actuate these SMP devices are presented in order to provide design criteria and guidelines for intravascular, laser activated SMP devices.

MATERIALS AND METHODS

A total of three devices will be presented: two interventional ischemic stroke devices (coil and umbrella) and one device for releasing embolic coils (microgripper). The optical properties of SMP, methods for coupling laser light into SMP, heating distributions in the SMP devices, and the impact of operating the thermally activated material in a blood vessel are presented.

RESULTS

Actuating the devices requires device temperatures in the range of 65-85 degrees C. Attaining these temperatures under flow conditions requires critical engineering of the SMP optical properties, optical coupling into the SMP, and device geometries.

CONCLUSION

Laser-activated SMP devices are a unique combination of laser-tissue and biomaterial technologies. Successful deployment of the microactuator requires well-engineered coupling of the light from the diffusing fiber through the blood into the SMP.

Transcatheter closure of high pulmonary artery pressure persistent ductus arteriosus with the Amplatzer muscular ventricular septal defect occluder

BACKGROUND

The design of devices currently used for closure of persistent ductus arteriosus (PDA) with high pulmonary artery pressure is not ideal and there is a risk of embolisation into the aorta.

OBJECTIVE

To investigate the use of the Amplatzer muscular ventricular septal defect occluder (AMVSDO) for treatment of PDA with high pulmonary artery pressure.

PATIENTS AND DESIGN

Seven patients, aged 5-12 years, with large PDAs and systemic or near systemic pulmonary artery pressure underwent attempted transcatheter closure using the AMVSDO. The device consists of two low profile disks made of a nitinol wire mesh with a 7 mm connecting waist. Balloon occlusion of the duct was performed before closure from the venous side, and prosthesis size was chosen according to the measured diameter of the occluding balloon. A 7 French sheath was used to deliver the device. All patients underwent a complete haemodynamic and angiographic study one year after occlusion.

RESULTS

The mean (SD) angiographic PDA diameter was 9.8 (1.7) mm (range 7-13 mm) and the mean AMVSDO diameter was 11.4 (1.8) mm (range 9-16 mm). Q(p)/Q(s) ranged from 1.9-2.2 (mean 2.0 (0.1)). Successful device delivery and complete closure occurred in all patients (100% occlusion rate, 95% confidence interval 59.04% to 100.00%). Mean systolic pulmonary artery pressures were as follows: before balloon occlusion, 106 (13) mm Hg; during occlusion, 61 (6) mm Hg; immediately after the procedure, 57 (5) mm Hg; and at the one year follow up catheterisation, 37 (10) mm Hg. Fluoroscopy time was 10.4 (4.3) min (range 7-18 min). No complications occurred.

CONCLUSIONS

AMVSDO is an important adjunct for closure of large PDAs associated with high pulmonary artery pressure. Further studies are required to document its efficacy, safety, and long term results in a larger number of patients.

II. Uterine fibroid embolization: technical aspects

Successful superselective catheterization of the uterine artery requires familiarity with female pelvic arterial anatomy, knowledge of effective catheter and guidewire combinations, and a few tricks. A learning curve can be expected for each of these elements, although it is assumed that the operator will already have experience in basic catheter techniques. Safe transcatheter delivery, understanding of embolization end points, and avoidance of nontarget embolization are essential. Equally important are knowledge of the properties of the embolic agents currently available and their indications for use. Uterine fibroid embolization unavoidably results in radiation exposure to the uterus and ovaries, and adherence to meticulous fluoroscopic technique is crucial to keep the absorbed dose as low as possible.

[Micro-coil embolization of a fistula of the circumflex ramus in the coronary sinus. Case report, differential therapy and review of the literature]

A 45 year old male suffered from typical exercise-induced dyspnoea and angina. Crohn's disease treated with glucocorticoids was present for 18 years. Coronary angiography revealed small left anterior descending and right coronary arteries without reference to coronary artery disease, while the main stem and circumflex artery were severely dilated due to a fistula (diameter 5.5 mm) into the coronary sinus with a left/right shunt amounting to 35%. Haemodynamics, significant risk of endocarditis with chronic inflammatory bowel disease and obligatory glucocorticoid treatment were indications for fistula closure. As an alternative to surgical correction, the coronary fistula was totally occluded by antegrade micro-coil embolization. The present report offers a review on differential therapeutic considerations and specific treatment options including novel interventional modalities for coronary fistulas.

Early endovascular treatment of ruptured cerebral aneurysms in patients in very poor neurological condition

OBJECTIVE

In patients in very poor neurological condition (World Federation of Neurosurgical Societies Grade V) with aneurysmal subarachnoid hemorrhage, early surgery to prevent rebleeding and to allow appropriate treatment of complications is often difficult. The aim of the present study was to evaluate whether early endovascular treatment followed by aggressive proactive treatment of complications (prophylactic hypervolemic hemodilution, hypertensive treatment in the event of systemic hypotension, and appropriate treatment of intracranial hypertension) is an acceptable management strategy for these patients.

METHODS

We prospectively studied 11 consecutive patients who presented with acutely ruptured aneurysms and were in very poor neurological condition after resuscitation (World Federation of Neurosurgical Societies Grade V) but did not have a significant intracerebral hemorrhage. These patients received endovascular treatment with Guglielmi detachable coils (Boston Scientific/Target, Fremont, CA). Follow-up consisted of a clinical evaluation based on the Glasgow Outcome Scale. A control angiogram was obtained after 6 months in patients with favorable outcomes to evaluate the occlusion of the aneurysm.

RESULTS

There were no deaths or complications directly related to the procedure. Two patients died as a consequence of increased intracranial pressure. The mean follow-up of the surviving patients was 12 months. Two patients had early rebleeding after the coiling and required further treatment. Four patients had good outcomes, two patients were moderately disabled, and three patients were severely disabled.

CONCLUSION

This study demonstrates that early endovascular treatment of acutely ruptured cerebral aneurysms in patients evaluated as World Federation of Neurosurgical Societies Grade V allows for aggressive treatment of intracranial hypertension and vasospasm. More than half of the patients had favorable outcomes. Therefore, early endovascular treatment seems to be a valuable alternative to early surgery in patients who present with a very poor clinical grade after subarachnoid hemorrhage. The results of this study are promising but must be interpreted with caution, because a small number of patients were studied.

Detection of the residual lumen of intracranial aneurysms immediately after coil embolization by three-dimensional digital subtraction angiographic virtual endoscopic imaging

OBJECTIVE

Detection of a small residual lumen after coil embolization is often difficult because of the coil mass and the overlap of the cerebral arteries. The purpose of this study was to assess the usefulness of virtual endoscopic (VE) analysis of three-dimensional digital subtraction angiographic (DSA) images for evaluation of aneurysmal occlusion immediately after the procedure.

METHODS

Twenty-seven intracranial aneurysms were treated with coil embolization using a three-dimensional DSA system. Biplane and rotational DSA scanning was performed before and immediately after the procedures. VE images were obtained at a separate workstation, after transfer of the rotational images. Two-dimensional (2D) DSA images and VE images obtained after the procedure were assessed with respect to aneurysmal occlusion. Morphological outcomes and other factors, including location, size, volumetric ratio (coil volume/aneurysm volume), and residual sites, were also evaluated.

RESULTS

Seven aneurysms were evaluated as complete occlusion (CO) on both 2D DSA images and VE images. Twelve aneurysms exhibited residual lumina on both 2D DSA images and VE images. Five aneurysms were evaluated as CO on 2D DSA images and as incomplete occlusion on VE images. There were no recurrences among the aneurysms that were evaluated as CO on VE images. Two of five aneurysms that were evaluated as CO on 2D DSA images and as incomplete occlusion on VE images demonstrated regrowth in follow-up examinations. Residual sites and volumetric ratios were correlated with aneurysmal regrowth.

CONCLUSION

VE imaging can demonstrate a residual lumen more frequently than can 2D DSA imaging and is useful for evaluating aneurysmal occlusion after coil embolization.

Performance of long J-shaped coils in large and giant intracranial aneurysms: an in vitro study

We evaluated the performance of long straight coils (Detach-18 J-shaped coils) in large and giant in-vitro aneurysms. The coils consisted of a distal semicircular part 7 or 15 mm in diameter and a proximal 70 cm straight part having three types of stiffness: soft, standard, and stiff. We first investigated the ease of passage through a microcatheter in a realistic cerebral vessel model. Second, we made silicone models simulating lateral-type aneurysms of various spherical dome diameters (12, 15, 20 and 30 mm) and neck sizes (3-10 mm; dome-to-neck ratio approximately 3:1) and connected them to a pulsating circulatory pump. We evaluated the anchoring and folding patterns of the coils, stability of the microcatheter and coils in the aneurysm, and smoothness of delivery and retrieval of coils. Third, we compared the conformability of a coil in a large, irregular aneurysm with that of a spiral coil. The long J-shaped coils were easily advanced and retrieved through a microcatheter in a tortuous vessel model. In 12 mm spherical aneurysms, each coil made a complex framework, and knot formation or damage to the coil during withdrawal was often observed. In 15 mm aneurysms, the coils were all easily delivered and retrieved; standard-stiffness coils adapted best to this size. In 20 mm aneurysms, frameworks were less complex but still good with a standard or stiff coil, but those with soft coil were unstable and changed significantly within 3 min of detachment due to gravity and pulsatile flow. In 30 mm aneurysms, soft coils filled only the lower part during introduction, whereas a stiff coil still made a favourable framework. Conformability of a long J-shaped coil was superior to that of a spiral coil in a large, irregular aneurysm. Long J-shaped coils conform well to various configurations of large and giant aneurysms and can shorten procedures since a larger implant volume can be delivered with a single coil. Their principle of action may promote more favourable occlusion of irregular and large aneurysms by improved conformability and stability.

Renal contraction therapy for enlarged polycystic kidneys by transcatheter arterial embolization in hemodialysis patients

Kidneys of patients with autosomal dominant polycystic kidney disease (ADPKD) usually continue to increase in size, even after patients begin dialysis therapy, and the mass effects may lead to severe complications. Such external conventional therapies as surgical and laparoscopic procedures have not yielded satisfactory results. Because kidneys in patients with ADPKD usually are supplied by well-developed arteries, we attempted renal contraction therapy in patients with ADPKD by renal transcatheter arterial embolization (TAE) using intravascular coils. After obtaining informed consent, we selected anuric patients on dialysis therapy with markedly distended abdomens or macroscopic hematuria. Between October 1996 and December 2000, a total of 64 patients were treated. Renal size, abdominal circumference, dry weight, hematocrit, and insulin-like growth factor-I were measured before TAE and 3, 6, and 12 months after TAE. Renal sizes decreased to 73.8% +/- 12.0%, 61.7% +/- 14.7%, and 53.4% +/- 11.6% of preinterventional values at 3, 6, and 12 months after therapy, respectively (P < 0.0001). Abdominal circumference and dry weight were significantly decreased at 3, 6, and 12 months (P < 0.0001) compared with baseline values before therapy. Hematocrits increased sequentially after 3, 6, and 12 months (P < 0.0001). Levels of insulin-like growth factor-I an index of nutritional status, significantly increased at 3, 6, and 12 months compared with the baseline value (P < 0.001). This therapy was effective for all patients. Serious complications were not seen after this treatment, although such minor complications as fever and flank pain were observed within the first week after the procedure. Our internal treatment with TAE is a safe and effective procedure that has resulted in improvement in the quality of life and nutritional status of patients with ADPKD.

Experimental evaluation of a new transcatheter vascular embolization device in the swine model

PURPOSE

To evaluate a new transcatheter device suitable for arterial embolization in an animal model.

MATERIALS AND METHODS

A new prototype self-expanding braided embolic device (Embolizor), consisting of nitinol wire strands fixed at either end with platinum-iridium bands and covered with a film of polyethylene, was deployed through 5-F diagnostic catheters into renal artery branches in five swine. Standard stainless-steel spring coils were deployed in other renal branches and served as controls. The animals underwent follow-up selective renal arteriography to determine presence or absence of vessel recanalization or device migration 15-23 days after device deployment. Histopathologic evaluation of target vessels and peripheral renal parenchyma was also performed.

RESULTS

Ten Embolizors and 10 stainless-steel coils were deployed in arteries ranging in size from 1.8 to 3.0 mm in diameter. The Embolizor was easily and precisely deployed. Angiographic evidence of vascular occlusion in the Embolizor group was noted within 30 seconds in eight device deployments and within 5 minutes in two. No early or delayed device migration was noted on follow-up arteriography. In the control group, seven of 10 previously occluded arteries were recanalized. No recanalization was noted in the Embolizor group. Light microscopy revealed evidence of infarction in all specimens examined. Whereas three specimens in the Embolizor group contained occasional giant cells, there were numerous multinucleated giant cells present within the interstices of all control spring coils.

CONCLUSION

The Embolizor was easily, precisely, and successfully deployed through standard selective diagnostic angiographic catheters. Short-term follow-up demonstrated no recanalization or migration of the device. The Embolizor was shown on histopathologic analysis to have no significant foreign body reaction.

Comparison of cellulose acetate polymer and electrolytic detachable coils for treatment of canine aneurysmal models

OBJECTIVE

Electrolytic detachable coils (EDC) have been the main embolic materials for intracranial aneurysms. Liquid aneurysmal embolic materials represented by cellulose acetate polymer (CAP) are still in controversy. In this research, the embolization results and pathological reactions after embolization of canine aneurysmal models with EDC or CAP were observed and compared.

METHODS

The canine aneurysmal models constructed by anastomosis of venous pouches were randomly grouped. The aneurysms were respectively occluded with CAP and electrolytic detachable coils that was named by Wu electrolytic detachable coil (WEDC) and made by us. Angiogram follow-ups were performed at 24-hour, 2-week, and 2-month after embolization. The occluded aneurysms were dissected in each stage for light microscopic, electron microscopic, and histochemical research.

RESULTS

The effect of embolization was significantly better with WEDC than that with CAP (chi2 = 5. 56, P < 0.05). Post-embolized complications such as aneurysm rupture and stenosis of parent arteries could only be found in CAP group. Pathological research showed that CAP mass could packed the aneurysms more densely than coils. Acute chemical damage of aneurysmal wall and inflammatory cell infiltration was prominently found in early stage after CAP-embolization. Organization of thrombus inside aneurysms and formation of endothelial tissue over the orifices of aneurysmal necks could be found in both groups 2 months after embolization. But parts of coils might be exposed outside endothelial layer.

CONCLUSIONS

EDC are still the most safe, efficient, and reliable instruments to embolize aneurysm. CAP should be improved further to solve the problem of strong chemical corrosion and difficulty in control before it is widely used.

Transcatheter closure of the patent ductus arteriosus with new-generation devices: comparative data and follow-up results

BACKGROUND

Many devices currently used for the closure of the patent ductus arteriosus are claimed to be safe and cost-effective, but only few data exist with respect to the gold standard of the Rashkind occluder. The aim of this study was to assess the efficacy and safety of three new different devices and to compare the results to those of a control group of patients carrying a Rashkind occluder. This should provide the basis for further cost-analysis studies.

METHODS

The records of all patients who underwent closure of the patent ductus at our Institution from April 1989 to May 2001 were reviewed. Eighty patients (median age 10.3 years, median weight 27.6 kg) were treated (25 with a Rashkind device, 11 with Duct-Occlud coils, 35 with Cook detachable coils, 9 with the Amplatzer system).

RESULTS

Kaplan-Meyer estimates of long-term complete occlusion of the ductus showed, compared to the Rashkind device, a significant improvement for the Cook and Amplatzer (p = 0.025 and p = 0.003, respectively) devices but not for the Duct-Occlud coils (p = 0.165). One patient of the Duct-Occlud group (9%) and 3 with the Rashkind device (12%) featured a significant residual shunt and needed a second intervention. The complication rate was 4% for the Rashkind occluder, 5% for the Cook coils, 9% for the Duct-Occlud system, and 11% for the Amplatzer device (p > 0.05).

CONCLUSIONS

The new devices are as safe as the Rashkind occluder and provide effective treatment. The Cook coils and the Amplatzer occluder offer better results compared to the Rashkind and Duct-Occlud devices.