Kwang Bo Park

Arteriovenous Malformations of the Body and Extremities: Analysis of Therapeutic Outcomes and Approaches According to a Modified Angiographic Classification

Purpose: To propose a modified angiographic classification for peripheral arteriovenous malformations (AVMs) and to determine its value for assessing therapeutic outcomes and approaches to ethanol embolization of AVMs in the body and extremities. Methods: AVMs of the trunk and extremities were categorized according to the angiographic morphology of the nidus: type I (arteriovenous fistulae), type II (arteriolovenous fistulae), type IIIa (arteriolovenulous fistulae with non-dilated fistula), and type IIIb (arteriolovenulous fistulae with dilated fistula). Sixty-six patients (41 women; mean age 28.3 years, range 5–53) with inoperable AVMs in the body and extremities who underwent staged ethanol embolizations were retrospectively analyzed. Therapeutic outcomes and approaches were evaluated according the above classification system. Results: The 66 AVMs were composed of 30 (45%) type IIIb, 13 (20%) type II, 12 (18%) mixed types IIIa and IIIb, 9 (14%) mixed types II and IIIb, and 2 (3%) type IIIa. Ethanol embolization was most effective for type II (100%), and more effective for type IIIb (83%) than for type IIIa or mixed types (≤50%). Despite the use of the transarterial approach, direct puncture and transvenous approaches were more relevant for treating type II AVMs. Only the transarterial approach was used for treating type IIIa; both direct puncture and transarterial approaches were used for treating the other types. Conclusion: The described angiographic classification provides considerable information concerning the characteristics of AVMs in the body and extremities, the optimal therapeutic approach, and the likely therapeutic outcome.

Balloon-Occluded Retrograde Transvenous Obliteration of Gastric Varices: Outcomes and Complications in 49 Patients

OBJECTIVE Our aim was to evaluate the clinical outcomes, techniques, and complications of balloon-occluded retrograde transvenous obliteration for treating gastric varices with spontaneous gastrosystemic shunts. MATERIALS AND METHODS From November 2002 through October 2005, 49 consecutive patients with gastric varices were treated by balloon-occluded retrograde transvenous obliteration. The sclerosant was injected through the outflow veins during balloon occlusion. Immediate postprocedural CT scans were obtained to evaluate the procedural details. Recurrence and rebleeding of gastric varices and worsening of esophageal varices were evaluated by endoscopic examination and CT. The survival rates and prognostic factors after the procedure were also assessed. RESULTS There were six procedural failures and two procedure-related deaths. Disappearance or marked shrinkage of the treated gastric varices with no recurrent gastric variceal bleeding was noted in 39 patients (79.6% clinical success rate). Approximately two thirds of our patients experienced worsening of esophageal varices during the median follow-up period of 457 days. The cumulative survival rates at 1 year and 3 years after balloon-occluded retrograde transvenous obliteration were 83.1% and 65.7%, respectively. The prognostic factors associated with survival were the preprocedural Child-Pugh classification and the total bilirubin level. The survival rates and procedural outcomes for the patients with severely compromised liver function were poor. CONCLUSION Balloon-occluded retrograde transvenous obliteration is an effective treatment for the obliteration of gastric varices. However, application of this procedure to severely compromised patients should be considered carefully.

Natural history of spontaneous isolated superior mesenteric artery dissection derived from follow-up after conservative treatment.

OBJECTIVES Optimal treatment of spontaneous isolated superior mesenteric artery dissection (SISMAD) has not been established in part because the natural history of this rare vascular disease is not well established. We attempted to determine the natural history of SISMAD by observing patients who underwent conservative treatment. METHODS Among 58 consecutive patients with SISMAD, 46 who underwent conservative treatment and periodic follow-up of computed tomography (CT) angiography (CTA) were included for this study. Our first-line treatment for SISMAD patients was conservative (n = 53), reserving interventional treatment, either endovascular (n = 1) or surgical (n = 4), for patients with persistent abdominal pain despite conservative treatment or signs of bowel ischemia. We retrospectively investigated changes of the length, type, or remodeling of the dissection and superior mesenteric artery patency on multidetector CT scan. To evaluate clinical course, presence of persistent or recurrent abdominal symptoms was queried on an outpatient base. RESULTS After 23.0 (median, range 6.5-74.2) months, follow-up CT angiograms showed diminished extent of the false lumen size in 19 (41.3%), no change in 20 (43.5%), diminished length of dissection in 11 (23.9%), and complete remodeling of dissection in seven (15.2%) patients. No patient showed dissection progression on follow-up angiogram. During the follow-up period, 10 (26.3%) patients reported nonspecific, mild abdominal discomfort, however, no patient developed recurrent abdominal pain following conservative treatment. There was no mortality related with SISMAD. CONCLUSIONS After conservative treatment of SISMAD, we have observed that the majority of patients showed improvement or no change on both angiogram and clinical examination. We believe this observation supports an approach of conservative treatment for patients with SISMAD.

Peripheral Arteriovenous Malformations with a Dominant Outflow Vein: Results of Ethanol Embolization

Objective To assess retrospectively the treatment results of ethanol embolization of peripheral arteriovenous malformations (AVMs) with a dominant outflow vein (DOV). Materials and Methods Nineteen patients who had peripheral AVMs with a DOV were enrolled in this study (mean age, 29.7 years; range, 15-42 years). Fifty-one ethanol embolizations (mean, 2.7; range, 1-8) were performed by direct puncture (n = 29), the transarterial approach (n = 13), the transvenous approach (n = 5), or a combination of methods (n = 4) under general anesthesia. Coil and/or core-removed guide wire embolization of the DOV or another flow occlusion technique (i.e., use of an external pneumatic pressure cuff) to achieve vascular stasis were required in all patients during ethanol embolization. Clinical follow-up (mean, 22.2 months; range, 1-53 months) was performed for all patients, and imaging follow-up (mean, 22.1 months; range, 2-53 months) from the last treatment session was performed for 14 patients. The therapeutic outcome (cure, improvement, no change, or aggravation) was assessed according to the clinical response and the degree of devascularization at angiography. Results Ethanol embolization was considered as an effective procedure in all patients. Thirteen (68%) of 19 patients were cured and six displayed improvement. Three of six patients with improvement needed further treatment sessions for residual AVMs. Four patients (21%) experienced a total of eight complications. Five complications (three events of a distal embolism and one event each of a urinary bladder necrosis and a brain infarct related to the accidental cannulation of the common carotid artery during insertion of the Swan-Ganz catheter) were major and three complications (skin necrosis) were minor. Conclusion Peripheral AVMs with a DOV can be effectively treated with a high cure rate by the use of ethanol embolization alone or in conjunction with the use of coil and/or core-removed guide wire embolization.

Early three-dimensional conformal radiotherapy for patients with unresectable hepatocellular carcinoma after incomplete transcatheter arterial chemoembolization: a prospective evaluation of efficacy and toxicity.

Purpose:We prospectively evaluated the efficacy and toxicity of early 3-dimensional conformal radiotherapy (3D-CRT) for patients with unresectable hepatocellular carcinoma (HCC) after incomplete transcatheter arterial chemoembolization (TACE). Methods:Patients with unresectable HCC who failed 1 or 2 courses of TACE were eligible for this study. Three dimensional-CRT was added for HCC with incomplete uptake of iodized oil. Between January 2006 and February 2007, 40 patients (43 lesions) were enrolled. TACE was performed by using Lipiodol and adriamycin, followed by Gelfoam embolization. Two cycles of TACE were performed in 24 patients (60%), whereas 16 patients (40%) underwent one cycle. The median dose of 54 Gy (3 Gy daily) was delivered with 3D-CRT. Tumor response was evaluated by changes in tumor size on serial computed tomography scans and toxicity was evaluated by the Common Terminology Criteria for Adverse Events v3.0. Results:An objective response was achieved in 27 of 43 lesions (62.8%), with a complete response in 9 lesions (20.9%) and partial response in 18 lesions (41.9%). The overall survival rate was 72.0% at 1 year and 45.6% at 2 years. There was no grade 3 or greater acute toxicity. Nine patients (22.5%) showed progression of the disease within the irradiated field during the follow-up and intrahepatic metastases developed in 16 patients (40.0%). Conclusion:Early 3D-CRT for HCC unresponsive to 1 or 2 cycles of TACE resulted in a 62.8% tumor response rate and relatively high complete response rates (20.9%) with acceptable toxicity. This study shows that the application of 3D-CRT could be considered for patients with incomplete TACE.

Extremity Arteriovenous Malformations Involving the Bone: Therapeutic Outcomes of Ethanol Embolotherapy

PURPOSE To assess retrospectively the therapeutic results, complications, and therapeutic approach to ethanol embolotherapy of extremity arteriovenous malformations (AVMs) involving the bone. MATERIALS AND METHODS From December 1996 to May 2009, 22 patients (12 male, 10 female; eight children, 14 adults; age range, 1-64 years) with extremity AVMs involving the bone underwent staged ethanol embolotherapy (range, 1-12 procedures; mean, 4.4 procedures) under general anesthesia. Four patients had pure bone AVMs and 18 had mixed bone and soft-tissue AVMs. Pulmonary artery pressure and arterial blood pressure were monitored as ethanol was injected. Ethanol embolotherapy was performed by direct puncture and/or transcatheter approach. Therapeutic outcomes were established by evaluation of the clinical response of symptoms and signs, as well as the degree of devascularization at follow-up angiography or computed tomography. RESULTS Ninety-six ethanol embolotherapy procedures were performed in 22 patients. Four (18%) were cured, 14 (64%) showed improvement, three (14%) showed no change, and one (4%) experienced treatment failure and amputation of the affected extremity. Ethanol embolotherapy was considered effective (ie, combined cure and improvement outcomes) in 18 patients (82%). Ten patients (45%) experienced complications. Twelve minor complications (skin and transient peripheral nerve injury; 13%) and one major complications (longstanding nerve palsy; 1%) occurred in 96 procedures. CONCLUSIONS Ethanol embolotherapy of extremity AVMs involving the bone has the potential to eliminate or improve symptoms in a high percentage of patients, with an acceptable risk of minor and major complications.

Percutaneous Angioplasty of Portal Vein Stenosis that Complicates Liver Transplantation: The Mid-Term Therapeutic Results

Objective We wanted to valuate the mid-term therapeutic results of percutaneous transhepatic balloon angioplasty for portal vein stenosis after liver transplantation. Materials and Methods From May 1996 to Feb 2005, 420 patients underwent liver transplantation. Percutaneous transhepatic angioplasty of the portal vein was attempted in six patients. The patients presented with the clinical signs and symptoms of portal venous hypertension or they were identified by surveillance doppler ultrasonography. The preangioplasty and postangioplasty pressure gradients were recorded. The therapeutic results were monitored by the follow up of the clinical symptoms, the laboratory values, CT and ultrasonography. Results The overall technical success rate was 100%. The clinical success rate was 83% (5/6). A total of eight sessions of balloon angioplasty were performed in six patients. The mean pressure gradient decreased from 14.5 mmHg to 2.8 mmHg before and after treatment, respectively. The follow up periods ranged from three months to 64 months (mean period; 32 months). Portal venous patency was maintained in all six patients until the final follow up. Combined hepatic venous stenosis was seen in one patient who was treated with stent placement. One patient showed puncture tract bleeding, and this patient was treated with coil embolization of the right portal puncture tract via the left transhepatic portal venous approach. Conclusion Percutaneous transhepatic balloon angioplasty is an effective treatment for the portal vein stenosis that occurs after liver transplantation, and our results showed good mid-term patency with using this technique.

Stent Placement for Chronic Iliac Arterial Occlusive Disease: the Results of 10 Years Experience in a Single Institution

Objective We wanted to retrospectively evaluate the long-term therapeutic results of iliac arterial stent placement that was done in a single institution for 10 years. Materials and Methods From May 1994 to April 2004, 206 patients who underwent iliac arterial stent placement (mean age; 64±8.8) were followed up for evaluating the long term stent patency. Combined or subsequent bypass surgery was performed in 72 patients. The follow up period ranged from one month to 120 months (mean; 31±25.2 months). The factors that were analyzed for their effect on the patency of stents were age, the stent type and diameter, the lesion site, lesion shape, lesion length, the Society of Cardiovascular and Interventinal Radiology criteria, the total run off scores, the Fontaine stage and the cardiovascular risk factors (diabetes mellitus, hypertension and smoking). Follow-up included angiography and/or CT angiography, color Doppler sonography and clinical evaluation with the ankle-brachial index. Results Two hundred and eighty-four stents were placed in 249 limbs of 203 patients. The technical success rate was 98% (203/206). The primary patency rates of the stents at 3, 5, 7 and 10 year were 87%, 83%, 61% and 49%, respectively. One hundred seventy-seven patients maintained the primary stent patency until the final follow up and 26 patients showed stenosis or obstruction during the follow up. Secondary intervention was performed in thirteen patients. Lesions in the external iliac artery (EIA) or lesions in both the common iliac artery (CIA) and EIA were a poor prognostic factor for stent patency. The run off score and stent diameter also showed statistically significant influence on stent patency. The overall complication rate was 6%. Conclusion Iliac arterial stent placement is a safe treatment with favorable long term patency. Lesions in the EIA or lesions in both the EIA and CIA, poor run off vessels and a stent having the same or a larger diameter than 10 mm were the poor prognostic factors for long term stent patency.

Prospective comparison of collagen plug (Angio-Seal) and suture-mediated (the Closer S) closure devices at femoral access sites.

Objective Rapid and effective hemostasis at femoral puncture sites minimizes both the hospital stay and patient discomfort. Therefore, a variety of arterial closure devices have been developed to facilitate the closure of femoral arteriotomy. The objective of this prospective study was to compare the efficacy of two different closure devices; a collagen plug device (Angio-Seal) and a suture-mediated closure device (the Closer S). Materials and Methods From March 28, 2003 to August 31, 2004, we conducted a prospective study in which 1,676 cases of 1,180 patients were treated with two different types of closure device. Angio-Seal was used in 961 cases and the Closer S in 715 cases. The efficacy of the closure devices was assessed, as well as complications occurring at the puncture sites. Results Successful immediate hemostasis was achieved in 95.2% of the cases treated with Angio-Seal, and in 89.5% of the cases treated with the Closer S (p < 0.05). The rates of minor and major complications occurring between the two groups were not significantly different. In the Closer S group, we observed four major complications (0.6%), that consisted of one massive retroperitoneal hemorrhage (surgically explored) and three pseudoaneurysms. In the Angio-Seal group, we observed three major complications (0.3%) that consisted of one femoral artery occlusion, one case of infection treated with intravenous antibiotics and one pseudoaneurysm. Conclusion The use of Angio-Seal was found to be more effective than that of the Closer S with regard to the immediate hemostasis of the femoral puncture sites. However, we detected no significant differences in the rate at which complications occurred.

Endovascular treatment combined with emboloscleorotherapy for pelvic arteriovenous malformations

PURPOSE To describe the clinical features and treatment outcomes after combined endovascular and embolosclerotherapy treatment of pelvic arteriovenous malformations (AVMs). METHODS From November 1996 to May 2011, we treated 12 patients (seven males, five females; mean age, 38.1 ±14.6 years; age range, 23-70 years) with pelvic AVMs. Our treatment strategy was coil embolization of a dilated draining vein of the AVM to reduce blood flow velocity in the AVM lesion and sclerotherapy of the residual arteriovenous fistulae with high-concentration ethanol to eradicate potential AVM recurrence. To ensure effective endovascular treatment, we used transarterial, transvenous, percutaneous, or combined access routes. Treatment outcomes were assessed with periodic computed tomography angiograms and clinical examinations. RESULTS During the follow-up period (mean, 33.2 months; median, 21.3 months; range, 1-96 months) after embolosclerotherapy, we observed complete remission (no residual or recurrent AVM lesion on follow-up computed tomography and complete symptomatic relief) in 10 (83.3%) patients and partial remission in two (16.7%) patients. One major complication of focal bladder necrosis occurred (1/22 sessions, 4.5%, 1/12 patients, 8.3%), but this resolved with conservative treatment. As early procedure-related complications, transient pulmonary hypertension and/or hemoglobinuria developed in 54.5% (12/22 sessions) and 22.7% (5/22 sessions) of patients, respectively. CONCLUSIONS Combined embolosclerotherapy of pelvic AVMs with coils and ethanol was efficacious at achieving complete remission.