Outcome in patients undergoing unilateral uterine artery embolization for symptomatic fibroids

AIMS: To evaluate patients undergoing uterine artery embolization for symptomatic fibroids who, for technical reasons, underwent unilateral rather than bilateral embolization. PATIENTS: Prospective data were collected on 109 patients undergoing uterine artery embolization for symptomatic fibroids. Of these, six underwent unilateral embolization. They were followed with ultrasound or magnetic resonance imaging (MRI) at 3, 6 and 12 months. Patients' histories were reviewed and patients were asked to evaluate their symptoms at 3, 6 and 12 months on a scoring system, which scored their pre-embolization symptoms as 10. RESULTS: In one case the patient's symptoms did not change in the first 3 months. This patient underwent a second embolization procedure to occlude the non-embolized uterine artery. In four cases the patients' symptoms had begun to resolve at 3 months and by 12 months the patients no longer required any further treatment. In one case the patient passed a 10 cm fibroid per vagina 2 months post uterine artery embolization. After this the patient had a normal uterus on MRI and no further symptoms. CONCLUSION: Where planned bilateral uterine artery embolization is not possible for technical reasons and a unilateral embolization only is performed a conservative approach is indicated.     

刮宫术前行子宫动脉栓塞术治疗347例子宫瘢痕妊娠的临床价值研究

目的：探讨于刮宫术前行子宫动脉栓塞术治疗子宫瘢痕妊娠的临床价值及其中的技术要点。 方法：选取2012年1月至2017年1月我科收治的子宫瘢痕妊娠患者共347例,使用可吸收明胶海绵颗粒"层叠式"栓塞子宫供血动脉,并在栓塞术后72 h内于超声监测下完成刮宫术。分析患者数字减影血管造影（DSA） 结果、子宫动脉栓塞手术结果、栓塞后疼痛情况、刮宫术中出血量及随访资料。结果：347例患者均成功接受造影检查,其中343例成功进行栓塞术,技术成功率98.85%（343/347）。4例患者造影检查后未实施栓塞治疗。347例中有22例存在异生血管,占6.34%;有异生血管的患者刮宫术中出血量高于无异生血管者。347例患者均成功在超声监视下行刮宫术,刮宫术中出血量10~2000 ml,其中302例出血量≤50 ml,33例50~600 ml,12例≥600 ml。栓塞后≤24 h行刮宫术者74例,24~48 h 234例,48~72 h 39例。栓塞后不同时间段行刮宫术的出血量差异无统计学意义。妊娠6周内与7~9周的刮宫术中出血量无统计学意义;而妊娠10~12周刮宫术中的出血量明显大于妊娠9周以内的患者,差异有统计学意义。321例患者栓塞术后下腹部疼痛程度轻微,无需药物处理。栓塞术后卵巢功能未受到明显影响。 结论：术前72 h内预先栓塞子宫供血动脉能有效预防刮宫术中大出血,且未明显影响到卵巢功能。     

Pharmacokinetic and safety study of doxorubicin-eluting beads in a porcine model of hepatic arterial embolization

PURPOSE: To present the pathologic and pharmacokinetic findings from hepatic embolization in a porcine model comparing doxorubicin-eluting beads with bland embolization and to correlate these findings with in vitro release kinetics. MATERIALS AND METHODS: Drug-eluting beads (DEB; 100-300 microm and 700-900 microm) loaded with 37.5 mg doxorubicin per milliliter hydrated beads were used to embolize the hepatic artery feeding the left lobe of the liver in young adult Yucatan pigs (n = 5 per group). Control animals underwent embolization with bland beads (100-300 microm; n = 5). Systemic plasma levels of doxorubicin were measured and correlated to in vitro drug release. Blood sampling and histopathologic examination were performed during the 90-day follow-up. RESULTS: All animals underwent successful embolization, and the treatment was well tolerated. Mean volumes of beads administered were 2.0-3.4 mL, with mean doses of 127.5 mg and 78.7 mg of doxorubicin for the 100- to 300-microm and 700- to 900-microm DEB groups, respectively. Gross pathologic examination revealed no effects on organs other than the liver. There was a transient increase in liver enzyme levels, particularly in the groups of animals who underwent embolization with 100- to 300-microm DEB. Histopathologic study showed mostly nonnecrotic changes with bland beads, whereas the effects of DEB were more severe, with large areas of pannecrosis evident with the 100- to 300-microm DEB. Maximum plasma concentrations were 651 ng/mL and 42.8 ng/mL for the 100- to 300-microm and 700- to 900-microm DEB groups, respectively, observed at 1 minute for both groups. Correlation with in vitro data showed a strong linear relationship. CONCLUSIONS: Hepatic arterial embolization with DEB was shown to be safe and well tolerated. The locoregional delivery of doxorubicin from DEB caused targeted tissue damage with minimal systemic impact and could be a promising new approach to transarterial chemoembolization of solid tumors.     

Initial clinical experience with biopolymer-coated detachable coils (HydroCoil) in peripheral embolization procedures

PURPOSE: To evaluate the technical and clinical success of HydroCoils in patients who underwent peripheral embolization procedures. MATERIALS AND METHODS: Between July 2006 and June 2007, 12 peripheral embolization procedures with HydroCoils in 11 patients (six male patients and five female patients; age range, 4-74 years; mean age, 46 y) were available for this retrospective review. The indications for embolization were hemorrhage (n = 4), aneurysm (n = 1), recurrent pulmonary arteriovenous malformation (n = 1), and protection before radioembolization and chemoembolization (n = 5). HydroCoil-10, -14, and -18 systems were used. Procedural and postprocedural follow-up imaging were reviewed by two interventional radiologists. Digital subtraction angiography (DSA) images were used to evaluate embolization success and vessel diameter. DSA and computed tomography (CT) angiography were used for follow-up, which included evaluation for recanalization and migration of coils. Chart review was also performed. RESULTS: All procedures were successful in occluding the target vessels (100%), which ranged from 1.2 mm to 8.2 mm in diameter (median, 2.2 mm). Immediate clinical success was achieved in all procedures (100%). Follow-up imaging was available in seven cases (four CT angiography and three DSA) at 2-108 days (mean, 42 d). No recanalization or migration of coils was found. There were no procedure-related complications, no clinical evidence of nontarget embolization, and no recurrence of presenting symptoms. CONCLUSIONS: The use of HydroCoils in peripheral arterial embolization procedures is effective and safe. They are viable alternatives to standard coils, particularly in tortuous, small target vessels or in cases in which controlled release is desirable.     

椎管内血管畸形的血管造影诊断与血管内介入治疗

目的:探讨椎管内血管畸形的血管造影诊断与血管内介入治疗效果。方法:回顾性分析66例椎管内血管畸形的选择性动脉造影与栓塞治疗资料。结果:66例椎管内血管畸形的血管造影表现为隐匿性髓内血管畸形者6例,余60例均能显示病变的范围、血供情况及其特征。12例髓内动静脉畸形、17例硬脊膜动静脉瘘和9例髓周动静脉瘘接受了栓塞治疗,其愈显率分别为58.3%、64.7%和66.7%。所有栓塞病例均无严重并发症发生。结论:经选择性血管造影确诊后行栓塞治疗是椎管内血管畸形安全有效的治疗手段。     

难治性鼻腔大出血的介入栓塞治疗

目的：探讨难治性鼻出血的选择性血管造影诊断和超选择性血管栓塞治疗。方法：用Seldinger技术经股动脉穿刺，送入5F Cobra导管，入颈总动脉，行选择性血管造影，对出血血管进行分析、诊断，采用直径为140-250um的真丝线段超选择性栓塞出血血管。结果：全部病例止血效果确切，术后随访2月-1年无复发，8例患者1周内行耳鼻喉手术，均明显减少了术中出血，降低了手术难度，提高了手术成功率。结论：本组资料表明：选择性血管造影的诊断，超选择性的栓塞治疗，相应大小的栓塞物质和颗粒，适当的栓塞速度是成功的关键。上颌动脉栓塞治疗是一种安全、有效、简便的止血与治疗方法，并为耳鼻喉的部分手术开辟了良好的新途径。     

Venous sac embolization of pulmonary arteriovenous malformation: Preliminary experience using interlocking detachable coils

Purpose: To evaluate the indication and advantages of venous sac embolization of pulmonary arteriovenous malformations (PAVMs) using interlocking detachable coils (IDCs). Methods: We performed percutaneous embolization in 12 PAVMs in four patients using IDCs, initially placed in the venous sac or at the feeding artery to prevent systemic migration of additional coils. We placed the IDCs in the venous sac in PAVMs with the following vascular architecture: the draining vein was larger than the feeding arteries and both vessels were interposed with the venous sac or there were short feeding arteries. Results: Complete occlusion was achieved in all 12 PAVMs without significant complications. We deployed IDCs in the venous sac in eight PAVMs and in the feeding artery in four. Conclusion: Venous sac embolization may be beneficial in PAVMs with large out-flow vessels or short feeding arteries. IDCs are suitable for this procedure.     

Partition of calibrated tris-acryl gelatin microspheres in the arterial vasculature of embolized nasopharyngeal angiofibromas and paragangliomas

PURPOSE: To determine the location of calibrated tris-acryl gelatin microspheres (TGMs) in the arterial vasculature of nasopharyngeal angiofibromas (NAFs) and paragangliomas (PGs). MATERIALS AND METHODS: Forty-nine specimens (25 PGs and 24 NAFs) treated operatively after embolization with TGMs of various sizes (100-300 microm to 900-1200 microm) were stained with hematoxylin and eosin saffron and analyzed at an objective magnification of 10 or 20 with a micrometric eyepiece (magnification, x12.5). The diameter of occluded vessels, their localization (intra- or extratumoral), and the number and diameter of TGMs they contained were determined. RESULTS: Embolized vessels (N = 1125) were measured: 440 in PGs and 685 in NAFs. Vessels were 89% intratumoral and 11% extratumoral. The diameter of the occluded vessels increased significantly with the size range of TGMs used for embolization for each tumor type (P < .0001). Intratumoral occluded vessels were significantly smaller than extratumoral vessels (P < .0001). Distribution of TGMs within the vascular network (intratumoral or extratumoral location) were similar for NAFs and PGs. The intratumoral and extratumoral dissemination of TGMs was different when comparing 100-300-microm TGMs versus 500-700-microm TGMs (P = .0006) as well as 300-500-microm TGMs versus 500-700-microm TGMs (P = .0001). CONCLUSIONS: The size of the vessels occluded by TGMs and their intra- or extratumoral location directly depend on the size of the injected TGMs. The vessels located inside the tumors were smaller than those located outside the tumors. A threshold for the intratumoral penetration of TGMs in the vasculature can be proposed from these data. There was no evidence of different behavior of TGMs in NAFs versus PGs.     

Pulmonary arteriovenous malformations: effect of embolization on right-to-left shunt,hypoxemia, and exercise tolerance in 66 patients

OBJECTIVE: This study assessed the effect and safety of percutaneous transcatheter coil embolization of pulmonary arteriovenous malformations. MATERIALS AND METHODS: In 58 (88%) of 66 patients, all malformations with feeding vessels greater than or equal to 3 mm in diameter were embolized with steel coils. Arterial oxygen saturation at rest and exercise, intrapulmonary right-to-left anatomic shunt fraction ((99m)Tc-macroaggregate injection), maximum exercise capacity (incremental work rate test), and pulmonary function were measured before and after embolization. Complications were analyzed. RESULTS: Three categories of patients were identified. Patients in group 1 (27%) had complete occlusion of all angiographically visible pulmonary arteriovenous malformations; patients in group 2 (61%) had complete occlusion of all malformations with feeding vessels greater than or equal to 3 mm in diameter, but with smaller lesions persisting; and patients in group 3 (12%) had incomplete embolization, with feeding vessels greater than or equal to 3 mm in diameter remaining. The mean right-to-left shunt after embolization was least in group 1 (7%), intermediate in group 2 (10%), and greatest in group 3 (19%). Arterial oxygen saturation and right-to-left shunt fraction returned to normal levels (>96% and <3.5%, respectively) in 33% of patients. A significant improvement occurred after embolization in carbon monoxide diffusing capacity per unit of alveolar volume and in exercise capacity in 16 and 10 patients, respectively. In 93 procedures, 12 complications (13%) occurred. CONCLUSION: Coil embolization of pulmonary arteriovenous malformations is effective in reducing right-to-left anatomic shunt fraction and in improving arterial oxygenation. Coil embolization of pulmonary arteriovenous malformations is well tolerated and has a low complication rate.     

Preoperative embolization of angiomas of the face. Remote angiographic results

Preoperative embolization was performed on 27 patients with facial angiomas supplied by the external carotid branches. Sixteen were males and 11 females; 13 of these angiomas were high-flow arteriovenous (A-V), 14 were low-flow capillary malformations. Fourteen patients underwent surgical removal after preoperative embolization; in this group embolization was carried out with Spongel in 3 cases and with Lyodura in 11 cases. In 12 of these patients the last angiographic examination was performed 3-6 years later: angiography evidenced no recurrence in 8 cases (67%), while in 3 cases (25%) there was capillary residual angioma of negligible size. Treatment was unsuccessful in one patient only, due to the large recurrent A-V angioma. Thirteen patients underwent embolization only, which was carried out with Lyodura in 10 cases, and with Ivalon in 3 cases. On 12 of these patients the last angiographic study was performed 2-14 months later: there was recurrent A-V angioma in 5 patients (42%), who underwent a subsequent embolization; angiography evidenced no recurrence in the other 7 patients (58%). In both series, the best results were obtained in the patients with low-flow capillary angiomas. Embolization and subsequent surgical removal are the treatment of choice for facial angiomas; embolization alone is useful in the management of surgically inaccessible vascular malformations, and it can be the only treatment in patients with small low-flow angiomas when distal occlusion of the feeding vessels with Lyodura or Ivalon particles is performed.     

Stereotactic single-dose irradiation of cerebral angioma

Angiomas are vascular malformations conceived as congenital anomalies. Surgical excision is the treatment of choice; an alternative is embolization. Radiation therapy is indicated: (1) for angiomas in vital or sensitive regions of the brain where they cannot be excised without the risk of a disabling neurological deficit and (2) for residual angiomas after partial embolization or incomplete surgical removal. The most effective radiotherapy for angiomas is radiosurgery. "Radiosurgery" is a term used for a special concept of radiotherapy. It describes stereotactically guided single high-dose irradiation. Therefore, a linear accelerator was modified at the German Cancer Research Center in Heidelberg. The precise localization of the target point and a steep dose gradient outside the target volume allow application of high doses to the tumor without damage to the surrounding normal brain tissue. Since 1984, in Heidelberg 41 patients with cerebral angiomas have been treated by stereotactic single high-dose irradiation (doses: 10-28 Gy). Eighteen patients were angiographically examined with a follow-up period longer than 18 months. In 7 patients, the pathological vessels was completely obliterated and in 6 partially. There was no change in 6 patients - all of whom received target doses of below 12 Gy.     

介入治疗在肝破裂出血中的应用

目的探讨介入治疗法在肝破裂(包括创伤性肝破裂和自发性肝破裂)中的应用。方法12例肝破裂出血患者的介入治疗是采用股动脉穿刺,肝动脉造影,以及靶血管(有活动性出血的血管)栓塞的治疗方法。结果12例造影有9例明确靶血管,3例显示肝表面不规则出血。12例均行栓塞治疗,其中,2例在48h内行两次栓堵。介入治疗后72h内随访观察,出血明显减少,血压趋于稳定。其中,9例痊愈出院,1例死于并发损伤,1例死于并发症,1例死于介入治疗后两周再次出血。结论介入治疗相对于外科手术具有操作简单、快捷、安全且创伤小等优点,是治疗肝破裂出血的一种有效方法。     

去甲斑蝥素微球对兔肝动脉栓塞作用的研究

目的观察去甲斑蝥素鄄海藻酸/聚酸酐微球(NAPMS)对兔肝动脉的栓塞作用。方法新西兰兔18只,在DSA下,行肝动脉造影后,以8mg/kg的剂量经肝动脉注入NAPMS,注入后10min、1,7、14、21和30d各取3只再次造影,观察肝动脉栓塞情况,并处死,取心、肝、肾、脾、肺、胰、胃等组织,观察病理变化,同时作肝、肾功能、血常规检查。结果兔肝动脉栓塞前,肝脏血管造影清晰,栓塞后10min造影,远端微血管消逝,肝动脉增粗、迂曲。介入栓塞后第1、7、14、21和30天造影远端血管均未显影。肝脏病理结果显示微球栓塞于肝窦前小动脉。栓塞后出现一过性肝功能损害,AST,ALT均在栓塞后1d达最高值,以后逐渐下降,7d左右恢复正常水平(P>0.05)。栓塞后白细胞出现一过性升高,第3天达最高值,第7天接近正常水平(P>0.05)。结论去甲斑蝥素微球具有良好的肝动脉末梢栓塞作用,栓塞时间在1个月以上,是较理想的介入栓塞剂。     

Embolotherapy of persistent endoleaks after endovascular repair of abdominal aortic aneurysm with the ancure-endovascular technologies endograft system.

PURPOSE: Endoleak is a potential complication after endovascular repair of abdominal aortic aneurysm (AAA). It may result in continued growth of the aneurysm and potentially result in aneurysm rupture. The authors present their experience with embolotherapy in patients with persistent perigraft flow treated with the Ancure-Endovascular Technologies endograft system. MATERIALS AND METHODS: Between February 1996 and August 1998, 54 patients underwent successful repair of AAA with use of the Ancure system. All underwent operative angiography and discharge computed tomography (CT). Follow-up included CT at 6, 12, and 24 months, and CT was also performed at 3 months if an endoleak was present on the discharge CT. Persistent endoleak was defined as perigraft flow still present on the 6-month CT. Seven of 21 initial endoleaks persisted at 6 months. Six patients returned for embolization of the perigraft space and outflow vessels including lumbar arteries and the inferior mesenteric artery (IMA). RESULTS: Five of the six patients had leaks from the proximal (n = 1) or distal attachment sites (n = 4) of the Ancure system with outflow into lumbar arteries and/or the IMA; one leak was caused by retrograde IMA flow. The six patients underwent nine embolization procedures with only one minor complication. Follow-up CT showed complete resolution of endoleak and decrease in size of the aneurysm sac in all patients. CONCLUSIONS: Although endoleak is commonly seen initially with the Ancure system, persistent leak occurred in 13% of the patients in the study. Persistent flow in most patients arises from a graft attachment site combined with patent outflow vessels such as the IMA or lumbar arteries. Persistent endoleaks can be effectively and safely embolized with use of a combination of coil embolization of the perigraft space and embolization of outflow vessels. Such intervention resulted in a decrease in size of the aneurysm sac.     

Clinical evaluation of cellulose porous beads for the therapeutic embolization of meningiomas

BACKGROUND AND PURPOSE: Cellulose porous beads (CPBs) are a new, exceptionally uniformly sized, nonabsorbable embolic agent. We evaluated their efficacy in the preoperative embolization of meningiomas. METHODS: In 141 consecutive patients, we used CPBs (200-microm diameter) for the preoperative embolization of meningiomas. We selected patients whose tumors were > or =4 cm with 50% of blood to the tumor supplied by the external carotid artery (ECA). All patients underwent a provocation test before embolization. The percentage of blood supplied to the tumor by the internal carotid artery and ECA was determined angiographically. Nonenhanced areas on postembolization MR imaging were calculated. Intraoperative blood loss, units of blood transfusion, and hemostasis at the time of surgery were recorded for each patient. The interval between embolization and surgery was intentionally longer than 7 days. RESULTS: Of the 141 patients, 128 underwent CBP embolization. Eleven patients had positive provocation test results, and 2 had vasospasm; they were not CBP embolized. In 72% of the patients CBP embolization achieved reduction in the flow of the feeding artery by more than 50%. The nonenhanced area on MR imaging was not significantly correlated with the degree of ECA supply or devascularization. The interval between embolization and surgery was 8-26 days (mean, 9.9 days). The longer this interval, the greater was the tumor-softening effect and the rate of tumor removal. CONCLUSIONS: CPBs may be useful for the preoperative embolization of meningiomas. To increase the efficacy of CPB embolization, the interval to surgery should be at least 7 days.     

Efficacy of trisacryl gelatin microspheres versus polyvinyl alcohol particles in the preoperative embolization of meningiomas

BACKGROUND AND PURPOSE: Trisacryl gelatin microspheres are a new, commercially available nonabsorbable embolic agent. The purpose of this study was to evaluate their efficacy in the preoperative embolization of meningiomas as compared with polyvinyl alcohol (PVA) particles of various sizes. METHODS: In 30 consecutive patients, trisacryl gelatin microspheres (150-300 microm) were used for the preoperative superselective embolization of meningiomas (group 1). Thirty other consecutive patients had embolization with PVA particles of 45 to 150 microm (n = 15, group 2) and of 150 to 250 microm (n = 15, group 3). Extent of devascularization, intraoperative blood loss, blood transfusion, and hemostasis at the time of surgery were recorded for every patient. The inflammatory reaction, the extent of necrotic areas, and the most distal intravascular location of the embolic agent (arterial, arteriolar, precapillary, capillary) were recorded. RESULTS: There was no significant difference in the extent of angiographic devascularization among the groups. Intraoperative blood loss differed significantly between groups 1 and 2 and groups 1 and 3, but not between groups 2 and 3. The trisacryl gelatin microspheres were located more distally in tumor vessels than were the PVA particles of either size. The extent of intratumoral necrosis was not significantly different between the two embolic agents. In all groups there was a mild inflammatory tissue reaction in the vicinity of the embolic agent. CONCLUSION: Trisacryl gelatin microspheres may be effective in the preoperative embolization of meningiomas, producing significantly less blood loss at surgery than seen with PVA particles of either size, possibly because of the significantly more distal vascular penetration of the microspheres.     

血余炭栓塞狗肾动脉病理改变的初步研究

目的：观察中药血余炭栓塞狗肾动脉的病理改变，为临床提供实验依据。方法：将中药血余炭磨制成200-500μm大小的颗粒，超选栓塞部分末梢动脉血管。栓塞术后第7、14和56天分别处死1、2和3号犬，取出双肾固定，制作病理标本。结果：栓塞术后第7天，肉眼见栓塞部分肾脏缩小，切面末梢血管内有栓塞剂；镜下见血余炭栓塞剂附着于血管壁伴血栓形成。栓塞术后第14天，炎性反应明显，并有少量出血，血管壁炎性坏死，血栓逐渐机化。栓塞术后第56天见栓塞部分肾脏明显缩小，有大面积的缺血性梗死；镜下见血栓完全机化，栓塞组织呈缺血性梗死，栓塞血管有少量再通。结论：血余炭栓塞的病理过程为：血余炭附着血管壁，诱发血栓形成，血栓机化，血管壁炎性坏死，管腔闭塞，栓塞组织缺血性梗死，栓塞血管少量可再通。     

Tailored cognitive testing with provocative amobarbital injection preceding AVM embolization

BACKGROUND AND PURPOSE: Transarterial embolization of cerebral arteriovenous malformations (AVMs) has been associated with postprocedural neurologic complications in 7-39% of patients. We sought to determine whether a method of targeted neurologic and cognitive testing during AVM embolization reduces the incidence of focal cognitive and other neurologic deficits associated with the procedure. METHODS: A cognitive neurologist extensively examined 12 patients prior to AVM embolization. In each patient, a battery of tests tailored to their specific abilities was developed by using stimuli selected from standard and experimental cognitive tests to probe specific brain regions related to the location of the AVM. In each feeder vessel to be embolized, a 50-mg bolus of sodium amobarbital was superselectively administered through a microcatheter; this was followed immediately by neurologic and cognitive testing with the tailored battery. After testing, the position of the microcatheter tip was checked with fluoroscopy. If the provocative test results were negative, the evaluated feeder was embolized with N-butyl cyanoacrylate glue. RESULTS: Although results with 27 of 29 provocative amobarbital injections were negative, results with two injections in two different individuals revealed cognitive deficits during tailored provocative testing. In both, the evoked deficits resolved with dissipation of the amobarbital effect; the feeder vessels were not embolized. Neurologic and cognitive evaluation after each of 27 embolizations revealed no major or minor deficits. CONCLUSION: In our experience, provocative amobarbital testing prior to AVM embolization was helpful in identifying vascular territories where embolization may lead to neurologic and cognitive deficits.     

Embolization of Collateral Vessels Using Mechanically Detachable Coils in Young Children with Congenital Heart Disease

Our objective was to evaluate the usefulness of embolizing collateral vessels using mechanically detachable coils (MDCs) in children aged 3 years or younger with congenital heart disease. The subjects were 8 children with congenital heart disease featuring collateral vessels (age 18 days–3 years): 3 with a single ventricle, 2 with the tetralogy of Fallot, 2 with pulmonary atresia, and 1 with a ventricular septal defect. The embolized vessels were the major aortopulmonary collateral artery (MAPCA) in 5 patients, the persistent left superior vena cava in 2, and the coronary arteriovenous fistula in 1. A 4 or a 5 F catheter was used as the guiding device, and embolization was performed using MDCs and other conventional coils introduced through the microcatheter. One patient had growth of new MAPCAs after embolization, and these MAPCAs were also embolized with MDCs. Thus, a total of 9 embolization procedures were performed in 8 patients. Complete occlusion of the collateral vessels was achieved in 8 of 9 procedures (89%). Seven of 8 patients (88%) had uneventful courses after embolization, and MDC procedures appeared to play important roles in avoiding coil migration and achievement of safe coil embolization. One patient who underwent MAPCA embolization showed no improvement in heart function and died 2 months and 19 days later. Embolization of collateral vessels using MDCs in young children with congenital heart disease can be an effective procedure and a valuable adjunct to surgical management.     

Pathologic evaluation of a spherical polyvinyl alcohol embolic agent in a porcine renal model

PURPOSE: To evaluate the effects of a spherical embolic agent consisting of polyvinyl alcohol (PVA) and to compare this agent with commercially available embolization agents. MATERIALS AND METHODS: Eleven miniature pigs were included in the study population. The upper poles of both kidneys were selected as the target organs for embolization. PVA spheres (700-900 micro m) were used in nine kidneys, PVA particles (500-710 micro m) were used in six kidneys, gelatin spheres (700-900 micro m) were used in five kidneys, and gold-colored gelatin spheres (700-900 micro m) were used in three kidneys. Two animals were killed immediately after embolization. In the remaining animals, angiography was performed before sacrifice 7 days (in five pigs) or 28 days (in four pigs) after embolization. Pathologic and histologic evaluation of the kidneys was performed. RESULTS: All agents resulted in target vessel occlusion and end-organ infarction. All arteries embolized with spherical agents were recanalized at follow-up angiography. In vessels embolized with PVA particles, the occluding plug consisted of thrombus and PVA. In vessels embolized with spherical agents, the occluding plug consisted mostly of the embolic agent. PVA spheres were associated with the mildest inflammatory responses at 7 and 28 days when compared with PVA particles and gelatin-based microspheres. Arterial wall destruction was seen to a greater extent in kidneys embolized with gelatin-based microspheres than in those embolized with PVA-based agents. CONCLUSIONS: The spherical, PVA-based embolization agent resulted in target organ infarction and temporary arterial occlusion. The inflammatory response to PVA spheres was significantly less aggressive than the response to other agents tested. Further study with clinical and long-term pathologic follow-up is suggested to determine if these findings may have favorable clinical implications for patients undergoing embolization procedures.