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Vascular and Interventional Radiology |
1 From the Departments of Radiology (Y.S.D., S.W.S., W.C.L., S.W.C., I.W.C.), Surgery (B.B.L., D.I.K.), Anesthesiology and Pain Medicine (B.S.S.), and Internal Medicine (D.K.K.), Cardiovascular Center, Samsung Medical Center and Sungkyunkwan University School of Medicine, Ilwon-Dong 50, Kangnam-Ku, Seoul 135–710, Korea; and Department of Radiology, Vascular Malformation Center, Englewood, Colo (W.F.Y.). Received March 8, 2004; revision requested May 19; revision received June 25; accepted July 27. Address correspondence to S.W.S. (e-mail: swshin@smc.samsung.co.kr).
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ABSTRACT |
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 TOP ABSTRACT INTRODUCTIONMATERIALS AND METHODS RESULTSDISCUSSIONREFERENCES |
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MATERIALS AND METHODS: Institutional review board approval was obtained for a retrospective review of patient medical and imaging records. Informed consent was not required by the institutional review board. Written consent for the procedure was obtained from all patients after a discussion about the advantages and risks of the procedure. After a general anesthetic was administered, 40 patients (16 male, 24 female; age range, 9–53 years) with inoperable AVMs in the body and extremities underwent staged ethanol embolizations (range, 1–24; median, 3). Pulmonary artery pressure and arterial blood pressure were monitored as ethanol was injected. Ethanol embolizations (50%–100% ethanol mixed with nonionic contrast material) were performed by using transcatheter and/or direct puncture techniques. Ten patients underwent additional coil deployment during ethanol embolization. Clinical follow-up (range, 2–48 months; mean, 14.6 months; median, 12 months) was performed in all patients, and results from imaging follow-up (range, 0–48 months; mean, 8.4 months; median, 6 months) were available from the last treatment session in 28 patients. Therapeutic outcomes were established by evaluating the clinical outcome of symptoms and signs, as well as the degree of devascularization at follow-up angiography.
RESULTS: One hundred seventy-five ethanol embolizations were performed in 40 patients. Sixteen (40%) of 40 patients were cured, 11 (28%) had partial remission, seven (18%) had no remission, and one (2%) experienced aggravation. Treatment failed in five patients (12%). Ethanol embolization was considered effective (cure, 16 patients; partial remission, 11 patients) in 27 patients (68%). Eleven patients will need further treatment sessions for residual AVMs. Twenty-one patients (52%) experienced complications. Twenty-seven minor complications (skin and transient peripheral nerve injuries) (27 [15%] of 175 procedures) occurred in 18 (45%) of 40 patients. All minor complications were healed with wound dressing and observation. Five major complications (five [3%] of 175 procedures) occurred in five (12%) of 40 patients, and four patients recovered completely.
CONCLUSION: Ethanol embolization has the potential for cure in the management of AVMs of the body and extremities but with acceptable risk of minor and major complications.
© RSNA, 2005
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INTRODUCTION |
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TOPABSTRACTINTRODUCTIONMATERIALS AND METHODS RESULTSDISCUSSIONREFERENCES |
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Percutaneous selective embolization can obliterate AVMs and has increasingly been employed for treatment. Although intraarterial embolization of AVMs by using particulate material can provide symptomatic relief, lesions recur in most cases because the nidus is not permanently occluded (7). Liquid embolic agents, such as isobutyl 2-cyanoacrylate or n-butyl cyanoacrylate, have been used for the treatment of AVMs (8,9). With use of these agents, however, it is difficult to control the level of occlusion, and it has also been reported that lesions treated with isobutyl 2-cyanoacrylate and n-butyl cyanoacrylate can recanalize (10,11). Superselective catheterization or direct puncture of the nidus and the use of ethanol as a permanent embolic agent have shown good clinical and radiologic implications by improving AVM treatment with an acceptable risk of morbidity (12–15).
The purpose of this study was to assess retrospectively the interim results and complications of ethanol embolization treatment of AVMs.
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MATERIALS AND METHODS |
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TOPABSTRACTINTRODUCTIONMATERIALS AND METHODS RESULTSDISCUSSIONREFERENCES |
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From November 1996 to August 2003, 40 consecutive patients (16 male, 24 female) with inoperable AVMs in the body and extremities underwent staged ethanol embolization. The mean age of the patients was 26.8 years (age range, 9–53 years). Fourteen patients had previously undergone unsuccessful operations and were no longer considered candidates for operation. Four patients had undergone unsuccessful feeding artery embolizations with microcoils or particles. In the remaining 22 patients, ethanol embolization was decided as the primary treatment method by vascular surgeons and interventional radiologists after full review of findings from clinical and imaging examinations of the patients. Diagnoses of AVMs were made on the basis of findings from clinical and imaging examinations, and patients often had more than one symptom and sign. Pulsating mass (25 [62%] of 40 patients) and pain (25 [62%] of 40 patients) were the most common signs and symptoms. Five patients (12%) had ulceration at the lesion site. Three patients (8%) had congestive heart failure consisting of dyspnea on exertion and cardiomegaly. Only two patients had bleeding; one patient had vaginal bleeding, and the other had bleeding at the ulcerated skin. Two patients had ischemic symptoms at the extremity of the distal part of AVMs by a steal effect through a high-flow shunt. One patient had dysmenorrhea, and another patient had bone overgrowth at the lesion site. The most common anatomic site of these AVMs was the upper extremity (n = 19), followed by the lower extremity (n = 16), the pelvic cavity (n = 5), and the trunk (n = 1). One patient had multiple AVMs in the upper and lower extremity. In four patients, venous malformations or lymphatic malformations were associated with the AVMs.
The lesion was first assessed at physical examination. To determine subsequent treatment, selective angiography, baseline technetium 99m-labeled red blood cell scintigraphy, magnetic resonance (MR) imaging, and/or color Doppler flow US imaging were performed to obtain detailed anatomic and hemodynamic information about the AVMs. Scintigraphy was performed after intravenous injection of 20 mCi (740 MBq) of technetium 99m-labeled red blood cells to evaluate the primary lesions and other associated vascular abnormalities. Scintigraphy included dynamic perfusion imaging followed by blood pool scintigraphy after 30 minutes. MR imaging was performed with a 1.5-T unit (Signa; GE Medical Systems, Milwaukee, Wis). The MR imaging protocol included transverse, sagittal, and coronal imaging with T1-weighted and gradient-echo sequences (field of view, 20–40 x 20–40 cm; section thickness, 8–12 mm; spacing, 10–14 mm; matrix, 256 x 192). Color Doppler flow US imaging was performed to evaluate the diameter and flow volume of the primary lesions, peak systolic velocity, resistive indexes, and the diameter of the feeding arteries of the AVMs. Selective and superselective angiography were required to accurately define the feeding arteries, draining veins, and nidus of the AVMs.
Embolization Procedure
All procedures were performed by two experienced interventional radiologists (Y.S.D. and W.F.Y., with 7 and 13 years experience in interventional radiology, respectively, when the study began in 1996). All ethanol embolizations were performed after a general anesthetic was administered to control pain. A Swan-Ganz catheter (Baxter Healthcare, Irvine, Calif) was inserted, and arterial pressure monitoring was performed to monitor pulmonary artery and arterial blood pressure as ethanol was injected.
Staged ethanol embolization was performed at the nidus itself and not at the vascular feeders; the goal was to embolize all or part of the nidus until complete resolution or improvement of clinical symptoms and signs was achieved. Routes of vascular access to the nidus were chosen after initial angiography. Transarterial, transvenous catheterization by using a coaxial catheter and/or percutaneous direct puncture was required to reach the nidus for embolization. The area of percutaneous puncture was prepared and draped. An 18–21-gauge needle (Disposable Cook Modified Needle; Cook, Bloomington, Ind) was advanced by using fluoroscopic guidance. In some cases, proximal inflow occlusion was performed during ethanol injection. To achieve vascular stasis, an intravascular occluding balloon catheter (Standard Occlusion Balloon Catheter; Boston Scientific, Natick, Mass) was used for the trunk and pelvic area, while external pneumatic blood pressure cuffs were used for the extremities.
Arteriography was performed to determine the exact flow characteristics of the AVMs. Moreover, to determine the volume of ethanol used during embolization and the rate of injection, test injections of contrast medium were performed by using fluoroscopic monitoring. The amount of ethanol used was based on the amount of contrast medium required to fill the AVM nidus without opacifying normal vessels. In most cases, absolute (99%) ethanol was used, but, in cases of microfistulas in the hand or foot, diluted (50%–70%) ethanol with nonionic contrast medium (iobitridol, Xenetix 300; Guerbet, Cedex, France) was used. In 10 patients, additional coil embolizations (Nester coil; Cook) of the dilated dominant outflow vein were performed by using direct puncture or transvenous catheterization to reduce the amount of ethanol and to stabilize the thrombosis in the dilated dominant outflow vein.
After ethanol injections, we waited 5–10 minutes and then performed arteriography to determine whether the AVMs were completely embolized. Complete embolization of at least one compartment of the AVM required meticulous repetition of the technique previously described in this article (16). When mean pulmonary artery pressure rose above 25 mm Hg, nitroglycerine was administered as a bolus injection (50–100 µg) and then infused continuously at 0.3–3.0 (µg · kg–1)/min through the Swan-Ganz catheter until mean pulmonary artery pressure reached normal levels. If pulmonary artery pressure remained elevated at the end of the session or if a large amount of absolute ethanol had been injected, the patient was kept in the intensive care unit for close pulmonary artery pressure monitoring and continuous administration of nitroglycerine.
The following morning, we performed color Doppler flow US imaging to evaluate the therapeutic effects of treatment and to assess complications, such as deep vein thrombosis. Color Doppler flow US imaging was performed by using an imager with a linear, phased-array high-frequency (5–10-MHz) transducer (Ultramark-9 or HDI 5000; Advanced Technology Laboratories, Bothell, Wash). The radiologist who performed color Doppler flow US imaging was not involved in the embolization procedure. Peak systolic velocity, resistive indexes, diameter of the feeding arteries of the AVMs, and diameter and residual flow volume in the nidus of the AVM were evaluated and compared with results from baseline color Doppler flow US imaging to determine the therapeutic effect of treatment. The deep veins of the treated extremity were also evaluated to determine the presence of deep vein thrombosis. The sonographic diagnostic criteria of deep vein thrombosis included the presence of echogenic intraluminal material, vein compressibility, and the absence of spontaneous or elicited blood flow.
To control swelling, a corticosteroid (0.1 mg/kg dexamethasone [Dexamethasone; Yuhan, Seoul, Korea]), was given immediately before the procedure and every 8 hours while patients were in the hospital. After patients were discharged, prednisolone (Solondo; Yuhan) was administered at 1 (mg · kg–1)/d (maximum daily dose, 15 mg) in three divided doses, which tapered over 1 week. Hemoglobinuria that occurred during the procedure was managed by means of hydration with an intravenously administered crystalloid solution. To evaluate renal function, serum creatinine and urea levels were measured at least once during the hospital stay.
A total of 175 ethanol embolizations (range, 1–24; mean, 4.4) were performed in 40 patients with AVMs. The number of embolization procedures that were required varied from patient to patient depending on the volume and behavior of the lesion. Eight patients underwent only one procedure, 17 patients underwent two to four procedures, and 15 patients underwent five or more procedures. In the patients who needed two or more procedures, the time interval between the procedures ranged from 2 to 12 months (mean, 3.8 months).
Evaluation of Clinical Data and Follow-up Results
Two radiologists (S.W.S. and W.C.L., with 4 and 3 years experience in interventional radiology, respectively) analyzed by consensus the therapeutic responses to ethanol embolization by comparing the degree of AVM devascularization (ie, 100%, 76%–99%, 50%–75%, or <50%) between baseline and final angiography. Two vascular surgeons (B.B.L. and D.I.K., with 15 and 6 years experience, respectively, in the evaluation of AVMs) and one interventional radiologist (Y.S.D.) evaluated by consensus the clinical outcome of symptoms and signs (ie, resolved completely, improved, no change, or aggravated) and complications at the congenital vascular malformation clinic. Complications were classified as either major or minor. Major complications included death, permanent adverse sequelae, requirement of major therapy, and prolonged hospitalization (>48 hours). Minor complications included any nonpermanent adverse sequelae, such as transient nerve injuries or spontaneously healed skin injury. Patients were physically and neurologically examined before and after embolization to assess complications. When major complications were observed, we reviewed the angiograms again to find the possible causes of major complications.
Periodic (1–6-month) follow-up evaluation was performed on the basis of physical examination, color Doppler flow US imaging, technetium 99m–labeled red blood cell scintigraphy, and/or MR imaging results during multisession therapy at the congenital vascular malformation clinic (B.B.L., D.I.K., Y.S.D.). Results of the follow-up evaluation were analyzed by consensus. As a rule, additional embolization was recommended if the symptoms and signs remained or if the AVMs were still present at follow-up imaging. Clinical follow-up after the last treatment session was performed in all patients and ranged from 2 to 48 months (mean, 14.6 months; median, 12 months). Results from imaging follow-up (range, 0–48 months; mean, 8.4 months; median 6 months) were available from the last treatment session in only 28 patients.
Therapeutic outcomes were established by evaluating the clinical outcome of symptoms and signs and the degree of devascularization at angiography. Cure was defined as complete resolution of the clinical symptoms and signs, with 100% devascularization of AVMs at angiography. Partial remission was defined as complete resolution or improvement of the clinical symptoms and signs, with 50%–99% devasculariztion of AVMs at angiography. No remission was defined as improvement or no change of the clinical symptoms and signs, with less than 50% devascularization of AVMs at angiography. Aggravation was defined as an aggravation of the clinical symptoms and signs, regardless of the degree of AVM devascularization at angiography. We defined treatment failure as any procedure that resulted in amputation of the extremities at the lesion sites or as instances when we could not approach the nidus of the AVM. Cure and partial remission were considered effective therapeutic outcomes of ethanol embolization of AVMs.
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RESULTS |
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TOPABSTRACTINTRODUCTIONMATERIALS AND METHODS RESULTSDISCUSSIONREFERENCES |
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In regard to therapeutic outcome of ethanol embolization, 16 (40%) of 40 patients were cured, 11 (28%) had partial remission, seven (18%) had no remission, and one (2%) experienced aggravation. Treatment failed in five patients (12%). In three of five patients in whom treatment failed, the lesions were totally removed by means of surgical amputation. Ethanol embolization was considered effective in 27 (68%) of 40 patients (cure, 16 patients; partial remission, 11 patients).
In regard to the clinical outcome, symptoms and signs were resolved completely in 23 (58%) of 40 patients and improved in six patients (15%). There were no symptoms and signs of improvement in 11 patients (28%) who underwent ethanol embolization. With regard to angiographic findings, AVMs were devascularized 100% in 16 patients (40%), 76%–99% in 10 patients (25%), 50%–75% in two patients (5%), and less than 50% in 12 patients (30%). We completed treatment in 27 patients (68%). Eleven patients are waiting for further sessions of ethanol embolization to treat residual AVMs, and two patients refused further treatment. The number of embolization procedures that were required varied from patient to patient depending on the volume and behavior of the lesion. Eight patients (20%) underwent only one procedure, 17 (42%) underwent two to four procedures, and 15 (38%) underwent five or more procedures. A single embolization was sufficient to achieve cure or partial remission of AVMs in only six patients (15%); 32 patients (80%) required multistage embolizations (Table).
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Patients in Whom Treatment Failed (Patients 36–40)
Treatment failed in five (12%) of 40 patients (patients 36–40). In two patients (patients 36 and 40) with microfistular AVMs in the hand and foot, direct puncture of the nidus was the only option owing to previous surgical ligation or coil embolization of the feeding arteries, which had been performed at another hospital. We tried to puncture the AVM directly with a 23-gauge needle but failed because the nidus was too small. Therefore, ethanol embolization was not considered in these two patients. Patient 40 finally underwent below-the-knee amputation of the lower leg because of an unhealing ulceration of the foot (Fig 4). One patient (patient 37) had diffuse subcutaneous AVMs and associated lymphatic malformations in his entire leg. Angiography showed enlarged feeding arteries and microshunting between arterioles and venules in the subcutaneous area of the entire leg. Although we performed superselective embolization by using a microcatheter with 50% ethanol, skin necrosis occurred at the treated area, and further treatment was abandoned. During treatment, infection occurred in the arm of one patient (patient 38), and, during follow-up, massive bleeding occurred in the arm of another patient (patient 39); both patients required life-saving amputation of their arm.
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There were five major complications in five (12%) of 40 patients (five [3%] of 175 procedures). These major complications included one infection, one case of acute renal failure as a result of muscle necrosis, one permanent median nerve injury of the arm, one brain infarct, and one case of focal urinary bladder necrosis. The infection was caused by severe skin necrosis during treatment and necessitated life-saving amputation of the arm (patient 38). Acute renal failure was caused by rhabdomyolysis of damaged back muscle after the first embolization of the back muscle AVMs. This patient (patient 33) recovered completely after 4 weeks of treatment and underwent two more sessions of embolization. One patient (patient 10) reported median nerve palsy after final embolization of the forearm AVM; this patient did not recover from nerve injury during a clinical follow-up of 15 months. One patient (patient 7) reported urinary frequency after complete embolization of the pelvic AVM. Focal necrosis of the urinary bladder was confirmed at cystoscopy and healed after 2 weeks.
Because four major complications were potentially related to nontarget embolization, we reviewed the angiograms of these four patients. We found that, in two patients, fine normal branches arose close to the malformations. The brain infarct was related to the accidental cannulation of the common carotid artery during insertion of the Swan-Ganz catheter. Infarction of middle cerebral artery distribution was confirmed at MR imaging. Fortunately, because infarction occurred in the nondominant hemisphere and in a clinically silent area, the patient (patient 8) did not have any neurologic complications.
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DISCUSSION |
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TOPABSTRACTINTRODUCTIONMATERIALS AND METHODS RESULTSDISCUSSIONREFERENCES |
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Primary surgical AVM resections were largely unsuccessful. Extirpations of the AVM nidus and proximal ligation of large feeding vessels have been complicated by massive intraoperative hemorrhage, adjacent organ damage, and high recurrence rates. In addition, surgical therapy has often precluded subsequent transcatheter therapy because ligation of the main feeding arteries makes catheter access difficult or impossible (5,6,18).
Polyvinyl alcohol, n-butyl cyanoacrylate, and isobutyl 2-cyanoacrylate have been used as embolic agents for the management of AVMs (9,16,18). It is well known that polyvinyl alcohol can, at times, induce acute occlusion of AVMs; however, the lesions usually recanalize during follow-up (18). An ideal isobutyl 2-cyanoacrylate and n-butyl cyanoacrylate mixture polymerizes in the nidus, and partial or total occlusion of the nidus can be achieved. Embolization with an inappropriate isobutyl 2-cyanoacrylate and n-butyl cyanoacrylate mixture, however, may result in proximal feeder occlusion, or the mixture may pass through arteriovenous shunts and embolize the lungs. When these agents are used, it is difficult to control the level of occlusion, and it has also been reported that lesions treated with isobutyl 2-cyanoacrylate and n-butyl cyanoacrylate can recanalize (10,11). Another problem is the formation of subcutaneous and intramuscular glue masses that can be a source of infection and can erode through tissue.
Ethanol has proved its efficacy in the management of peripheral AVMs (12,13,15,16). Ethanol has the unique ability to induce protein denaturation of the endothelial cells, with subsequent vessel wall denudation and thrombus formation. This results in complete obliteration rather than simple obstruction of the vessel lumen and does not allow recanalization because ethanol permanently damages the endothelium of the AVM nidus (16). Thus, ethanol embolization of AVMs is associated with excellent results and outcomes, as well as an increased chance for cure (12,13,15,16).
For localized AVMs, a single embolization procedure may be sufficient. Embolization of extensive, complex AVMs, however, requires multiple procedures for many reasons. Embolization is usually a lengthy procedure in which contrast material limits can be exceeded. Moreover, serial embolizations reduce the risk of excessive embolization, thereby decreasing the risk of tissue necrosis or complications resulting from postthrombosis edema (19). In our study, to achieve cure or partial remission of AVMs, a single embolization was sufficient in six patients (15%) with localized AVMs, and 32 patients (80%) required multistage embolizations.
In most patients, undiluted absolute (99%) ethanol was used. In cases of diffuse infiltrative microfistulas without a true nidus, diluted (50%–70%) ethanol with nonionic contrast medium was used. At that time, we used iobitridol because ionic and other nonionic contrast media make a precipitate of fine crystals when mixed with ethanol (20). Diluted ethanol does not induce thrombosis in large AVMs, but in fine infiltrative microfistular AVMs, we could achieve a thrombotic effect by using diluted ethanol with repeated injections.
To access the nidus of the AVM, we performed transarterial, transvenous catheterization by using a coaxial catheter and/or percutaneous direct puncture (8,11,21). We preferred to embolize the lesions by using an arterial approach when possible. When important normal arterial branches arose close to a malformation or when extreme arterial tortuosity or previous surgical ligation of feeding artery precluded successful transarterial catheterization, direct puncture or the transvenous approach was selected (8,11). In patients with a dilated dominant outflow vein, we performed coil embolization in the dilated dominant outflow vein by using direct puncture or transvenous catheterization with subsequent injection of ethanol, as previously reported by Yee and Yakes (22). Coil embolization decreases blood flow velocity, which can reduce the amount of ethanol used (23). In our study, additional coil embolization of the dilated dominant outflow vein was performed in 10 patients. Among these patients, seven experienced 100% devasculaization of their AVMs.
Complications of ethanol embolization are related to the tissues being embolized and to the systemic effect of ethanol. Complication rates for ethanol embolization of AVMs range from around 10% to 30%, and the most common complications are local tissue injuries, such as skin blistering or necrosis, and peripheral nerve palsy (10,14). In our study, the most common complications were minor complications that occurred in 18 (45%) of 40 patients (27 [15%] of 175 procedures); minor complications included skin blistering, skin necrosis, and transient nerve injury, all of which healed with wound dressing and observation. Skin graft was not required for any skin injury. When the lesions were located in the superficial subcutaneous area, there was a higher chance of skin blistering or necrosis. There were five major complications in five (12%) of 40 patients (five [3%] of 175 procedures), and, among these complications, four (except brain infarct) were potentially related to nontarget embolization. When we reviewed the angiograms of these four patients, we found that, in two patients, fine normal branches arose close to the malformations. Thus, careful and meticulous analysis of the angiogram is essential during ethanol injection.
Other complications of ethanol embolization include hemoglobinuria and cardiopulmonary collapse. Pulmonary embolism can theoretically occur as a result of thrombus dislodgment from the embolized AVMs (13,24–27). Cardiopulmonary collapse requiring resuscitation has been reported as a rare but serious sequela of the ethanol procedure (25). A bolus of ethanol that is injected into the pulmonary artery can induce precapillary artery spasm. This may then cause pulmonary artery pressure to rise, thereby increasing right ventricular afterload while decreasing right ventricular contractility and right ventricular output. This, in turn, causes decreased left ventricle filling, decreased left ventricle cardiac output, and systemic arterial hypotension. If these changes are severe enough, they can lead to cardiac arrhythmia and cardiopulmonary collapse (28). Pulmonary artery Swan-Ganz catheter and arterial pressure monitoring are essential to minimize the possibility of this event. If pulmonary artery pressure becomes pathologically high, the infusion of a vasodilator through the Swan-Ganz catheter can lower the intrapulmonary pressure. Hemoglobinuria secondary to hemolysis was observed in 16.7%–28% of patients in other series, with only one case of transient renal impairment (24,27). In these studies, one case of transient renal impairment could have been caused by contrast medium. In our study, there were no patients with renal impairment resulting from hemoglobinuria. Hydration, however, has been recommended for patients with hemoglobinuria (24,27).
Other embolic agents have been used by many authors to treat peripheral AVMs. White et al (9) reported long-term follow-up results for palliation of AVMs with the use of cyanoacrylate. Durable long-term (mean, 7.4 years) relief of symptoms was achieved in 11 patients with localized upper extremity AVMs, but there was high incidence of amputation in five (55.6%) of nine patients with lower extremity AVMs. Because glue embolization failure and a high amputation rate were associated with lower extremity AVMs, the final outcomes were worse than those reported in our study. Osuga et al (29) described their experience with sodium acrylate and vinyl alcohol copolymer particles in the management of facial and extremity AVMs in 25 patients (mean follow-up, 37.8 months). Symptom palliation was achieved in 80% of cases by using embolization alone or in combination with surgery, and there were no major complications. Osuga et al (29) did not, however, mention anything about a complete cure rate or radiologic follow-up. In our group, ethanol embolization was documented as effective in 27 (68%) of 40 patients (cure, 16 patients; partial remission, 11 patients). The clinical symptoms and signs of AVMs were resolved completely or improved in 29 patients (72%). We achieved 100% devascularization of AVMs in 16 patients (40%) and 76%–99% devascularization of AVMs in 10 patients (25%). We achieved 50%–75% devascularization in two patients (5%) and less than 50% devascularization in 12 patients (30%). Since some of these patients have extensive AVMs or have recently been enrolled in the treatment group, more sessions of ethanol embolization are necessary to achieve better results.
This study has some limitations. First, we report only the interim results of ethanol embolizations. Therefore, long-term follow-up after complete treatment is necessary. Second, because there is no standard report form for AVMs, we used our own criteria to assess the therapeutic effect; this can make it difficult to compare our results with those from other studies, except for those studies in which researchers present cure rates. Third, if we can measure the exact volume of AVMs by using noninvasive methods, we can decide the volume of ethanol and the number of treatment sessions more easily. Perhaps computed tomographic angiography can help to provide this information.
In conclusion, our interim results show that ethanol embolization has the potential to eliminate or improve symptoms of AVMs in a high percentage of patients but with the risk of minor and major complications. Inadvertent embolization must be avoided by using superselective catheterization or direct puncture of the nidus. The morbidity (minor and major) that is involved should also be clearly understood by the patients or family. Further detailed long-term assessment is necessary to prove the safety and efficacy of this treatment.
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FOOTNOTES |
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Authors stated no financial relationship to disclose.
Author contributions: Guarantors of integrity of entire study, Y.S.D., I.W.C.; study concepts, Y.S.D., W.F.Y., B.B.L.; study design, Y.S.D., S.W.S.; literature research, Y.S.D.; clinical studies, Y.S.D., W.F.Y., S.W.S., B.B.L., D.I.K., W.C.L., B.S.S., D.K.K., S.W.C.; data acquisition, Y.S.D., S.W.S.; data analysis/interpretation, S.W.S., W.C.L., B.B.L., D.I.K.; manuscript preparation, Y.S.D.; manuscript definition of intellectual content, Y.S.D., S.W.S.; manuscript editing, W.F.Y., B.B.L., S.W.S., I.W.C.; manuscript revision/review, S.W.S., I.W.C.; manuscript final version approval, all authors
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TOPABSTRACTINTRODUCTIONMATERIALS AND METHODS RESULTSDISCUSSIONREFERENCES |
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  D. Joffe and W. O. Bank Morbidity in a pediatric patient having alcohol ablation of an arteriovenous malformation. Can J Anesth, May 1, 2006; 53(5): 527 - 528. [Full Text] [PDF]
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