Portal Vein Stenting for Delayed Jejunal Varix Bleeding Associated with Portal Venous Occlusion after Hepatobiliary and Pancreatic Surgery

OBJECTIVE: The study aimed to describe portal stenting for postoperative portal occlusion with delayed (≥ 3 months) variceal bleeding in the afferent jejunal loop. MATERIALS AND METHODS: Eleven consecutive patients (age range, 2–79 years; eight men and three women) who underwent portal stenting between April 2009 and December 2015 were included in the study. Preoperative medical history and the postoperative clinical course were reviewed. Characteristics of portal occlusion and details of procedures were also investigated. Technical success, treatment efficacy (defined as disappearance of jejunal varix on follow-up CT), and clinical success were analyzed. Primary stent patency rate was plotted using the Kaplan-Meier method. RESULTS: All patients underwent hepatobiliary-pancreatic cancer surgery except two children with liver transplantation for biliary atresia. Portal occlusion was caused by benign postoperative change (n = 6) and local tumor recurrence (n = 5). Variceal bleeding occurred at 27 months (4 to 72 months) and portal stenting was performed at 37 months (4 to 121 months), on average, postoperatively. Technical success, treatment efficacy, and clinical success rates were 90.9, 100, and 81.8%, respectively. The primary patency rate of portal stent was 88.9% during the mean follow-up period of 9 months. Neither procedure-related complication nor mortality occurred. CONCLUSION: Interventional portal stenting is an effective treatment for delayed jejunal variceal bleeding due to portal occlusion after hepatobiliary-pancreatic surgery.

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.

Ethanol Embolotherapy of Pelvic Arteriovenous Malformations: an Initial Experience

OBJECTIVE: We retrospectively assessed the results of performing ethanol embolization for pelvis arteriovenous malformations (AVMs). MATERIALS AND METHODS: During the past 10 years, eight patients (8 females, age range: 27-52 years) with AVMs in the pelvic wall (n = 3) and uterus (n = 5) underwent staged ethanol embolizations (range: 1-5, mean: 2.5) under general anesthesia. Ethanol embolization was performed by the use of the transcatheter and/or direct puncture techniques. Clinical follow-up was performed for all of the patients, and imaging follow-up was available for seven patients. The therapeutic outcomes were established by evaluating the clinical outcome of the signs and symptoms, as well as the degree of devascularization observed on post-procedural angiography. RESULTS: During the 20 sessions of ethanol embolization, the solitary transarterial approach was used 14 times, the transvenous approach was used three times and direct puncture was used once. For two patients, the transarterial and transvenous or direct puncture approaches were used together in one session. For four patients, ethanol and coils were used as embolic agents, and n-butyl cyanoacrylate (NBCA) and ethanol were used in one patient. Seven (88%) of eight patients were cured of their AVMs and one patient (12%) displayed improvement. Major complications were seen in two patients (25%). CONCLUSION: Ethanol embolization is effective for the treatment of pelvic arteriovenous malformations, though there is a chance of a major complication.

Percutaneous Transluminal Angioplasty of Renal Artery Fibromuscular Dysplasia: Mid-term Results

OBJECTIVE: To evaluate mid-term imaging, clinical follow-up, and restenosis rates from patients that had undergone percutaneous transluminal renal artery angioplasty (PTRA) for symptomatic renal artery fibromuscular dysplasia (FMD). MATERIALS AND METHODS: Between March 1999 and July 2006, 16 consecutive renal artery FMD patients underwent PTRA for poorly controlled hypertension. The patients were enrolled into this retrospective study after receiving 19 primary and four secondary PTRAs in 19 renal artery segments. Follow-up monitoring of blood pressure, use of antihypertensive medication, and the serum creatinine level after PTRA were assessed at 1, 3, 6, 9, 12 months, and each following year. The degree of restenosis was evaluated with computed tomographic angiography (CTA) after PTRA at 6, 12 months, and every year if possible. Technical and clinical success rates for the treatment of FMD, and restenosis rates for the renal artery were evaluated. RESULTS: The technical success rate for primary PTRA was 79% (15/19) and the complication rate was 16% (3/19). Hypertension improved in 80% (12/15) of the patients after four weeks follow-up, and was finally cured or improved in 93% (14/15) during the mean follow-up period of 23.6 months. There was a cumulative 22% (4/18) restenosis rate during the follow-up period. All of the patients were treated with a second PTRA without complications and all of the patients were cured of hypertension after the second PTRA. CONCLUSION: Percutaneous transluminal renal artery angioplasty for clinically symptomatic renal FMD is technically and clinically successful and safe to perform. For all patients with restenosis, there was a good response after undergoing a second PTRA.

The Short-Term Effects of Balloon-Occluded Retrograde Transvenous Obliteration, for Treating Gastric Variceal Bleeding, on Portal Hypertensive Changes: a CT Evaluation

OBJECTIVE: We wanted to evaluate the short-term effects of balloon-occluded retrograde transvenous obliteration (BRTO) for treating gastric variceal bleeding, in terms of the portal hypertensive changes, by comparing CT scans. MATERIALS AND METHODS: We enrolled 27 patients who underwent BRTO for gastric variceal bleeding and they had CT scans performed just before and after BRTO. The pre- and post-procedural CT scans were retrospectively compared by two radiologists working in consensus to evaluate the short-term effects of BRTO on the subsequent portal hypertensive changes, including ascites, splenomegaly, portosystemic collaterals (other than gastrorenal shunt), the gall bladder (GB) edema and the intestinal wall edema. Statistical differences were analyzed using the Wilcoxon signed rank test and the paired t-test. RESULTS: Following BRTO, ascites developed or was aggravated in 22 (82%) of 27 patients and it was improved in two patients; the median spleen volumes increased from 438.2 cm3 to 580.8 cm3, and based on a 15% volume change cut-off value, splenic enlargement occurred in 15 (56%) of the 27 patients. The development of new collaterals or worsening of existing collaterals was not observed in any patient. GB wall edema developed or was aggravated in four of 23 patients and this disappeared or improved in five; intestinal wall edema developed or was aggravated in nine of 27 patients, and this disappeared or improved in five. Statistically, we found significant differences for ascites and the splenic volumes before and after BRTO (p = 0.001 and p < 0.001, respectively) CONCLUSION: Some portal hypertensive changes, including ascites and splenomegaly, can be aggravated shortly after BRTO.

Interventional Management of Malignant Colorectal Obstruction: Use of Covered and Uncovered Stents

Objective: We wanted to evaluate usefulness of uncovered stent in comparison with covered stent for the palliative treatment of malignant colorectal obstruction. Materials and Methods: Covered (n = 52, type 1 and type 2) and uncovered (n = 22, type 3) stents were placed in 74 patients with malignant colorectal obstruction. Stent insertion was performed for palliative treatment in 37 patients (covered stent: n = 23 and uncovered stent: n = 14). In the palliative group, the data on the success of the procedure, the stent patency and the complications between the two groups (covered versus uncovered stents) were compared. Results: The technical success rate was 89% (33/37). Symptomatic improvement was achieved in 86% (18/21) of the covered stent group and in 92% (11/12) of the uncovered stent group patients. The period of follow-up ranged from three to 319 days (mean period: 116+/-85 days). The mean period of stent patency was 157+/-33 days in the covered stent group and 165+/-25 days in the uncovered stent group. In the covered stent group, stent migration (n = 11), stent fracture (n = 2) and poor expansion of the stent (n = 2) were noted. In the uncovered stent group, tumor ingrowth into the stents (n = 3) was noted. Conclusion: Self-expanding metallic stents are effective for relieving malignant colorectal obstruction. The rate of complications is lower in the uncovered stent group than in the covered stent group.

Subintimal Angioplasty in the Treatment of Chronic Lower Limb Ischemia

OBJECTIVE: To present our experience with subintimal angioplasty (SA) for treatment of chronic lower limb ischemia (CLLI) and to assess its effectiveness and durability. MATERIALS AND METHODS: From April 2003 through June 2005, we treated 40 limbs in 36 patients with CLLI by SA. Balloons with or without secondary stent placement appropriate in size to the occluded arteries were used for SA of all lesions, except for iliac lesions where primary stent placement was done. The patients were followed for 1-23 months by clinical examination and color Doppler ultrasound and/or CT angiography. Technical results and outcomes were retrospectively evaluated. The presence of a steep learning curve for performance of SA was also evaluated. Primary and secondary patencies were determined using Kaplan-Meier analysis. RESULTS: Technical success was achieved in 32 (80%) of 40 limbs. There was no statistical difference between technical success rates of 75% (18/24) during the first year and 88% (14/16) thereafter. There were four complications (10%) in 40 procedures; two arterial perforations, one pseudoaneurysm at the puncture site, and one delayed hematoma at the SA site. Excluding initial technical failures, the primary patency rates at six and 12 months were 68% and 55%, respectively. Secondary patency rates at six and 12 months were 73% and 59%, respectively. CONCLUSION: Subintimal angioplasty can be accomplished with a high technical success rate. It should be attempted in patients with CLLI as an alternative to more extended surgery, or when surgical treatment is not recommended due to comorbidity or an unfavorable disease pattern.

Percutaneous Treatment of Failed Native Dialysis Fistulas: Use of Pulse-Spray Pharmacomechanical Thrombolysis as the Primary Mode of Therapy

OBJECTIVE: To determine the efficacy and outcome of percutaneous treatment in restoring the function of failed native arteriovenous fistulas (AVFs) where pulse-spray pharmacomechanical thrombolysis was used as the primary mode of therapy. MATERIALS AND METHODS: From June 2001 to July 2005, 14 patients who had thrombosis of native AVFs underwent percutaneous restoration following 20 episodes of thrombosis. These included 6 repeated episodes in one forearm AVF and two episodes in another forearm AVF. All patients except one were treated with urokinase injection utilizing the pulse-spray technique and had subsequent balloon angioplasty. One patient was treated by percutaneous angioplasty alone. We retrospectively evaluated the feasibility of percutaneous treatment in restoring the function of the failed AVFs. The primary and secondary patencies were calculated by using a Kaplan-Meier analysis. RESULTS: Both technical and clinical success were achieved in 15 (75%) of 20 AVFs. Four of the five technical failures resulted from a failure to cross the occluded segment. One patient refused further participation in the trial through a brachial artery access following failure to cross the occluded segment via an initial retrograde venous puncture. There were no major precedure related complications observed. Including the initial technical failures, primary patency rates at six and 12 months were 64% and 55%, respectively. Secondary patency rates at six and 12 months were 71% and 63%, respectively. CONCLUSION: Pulse-spray pharmacomechanical thrombolysis for treatment of the thrombosed AVFs is safe, effective and durable. This procedure should be considered as an option for the management of failed AVFs prior to surgical intervention.

Efficacy of Femoral Vascular Closure Devices in Patients Treated with Anticoagulant, Abciximab or Thrombolytics during Percutaneous Endovascular Procedures

OBJECTIVE: This study assessed the outcomes of using vascular closure devices following percutaneous transfemoral endovascular procedures in the patients who were treated with heparin, abciximab or thrombolytics (urokinase or t-PA) during the procedures. MATERIALS AND METHODS: From March 28, 2003 to August 31, 2004, we conducted a prospective and randomized study in which 1,676 cases of 1,180 patients were treated with one of the two different closure devices (the collagen plug device was Angio-SealTM; the suture-mediated closure device was The Closer STM) at the femoral access site after instituting percutaneous endovascular procedures. Among the 1,676 cases, 108 cases (the drug group) were treated with heparin only (n = 94), thrombolytics only (n = 10), heparin and thrombolytics (n = 3), or abciximab and thrombolytics (n = 1) during the procedures; 1,568 cases (the no-drug group) were treated without any medication. We compared the efficacy and complications between the two groups. Of the drug group, 42 cases underwent arterial closures with the collagen plug devices and 66 cases underwent arterial closures with the suture-mediated closure devices. We also compared the efficacy and complications between these two groups. RESULTS: The immediate hemostasis rates were 92.9% (1,456/1,568) in the no-drug group and 91.7% (99/108) in the drug group. Early complications occurred in four cases of the drug group. These included two episodes of rebleeding with using the Closer S, which required manual compression for at least 10 minutes, and two episodes of minor oozing with using one Angio-Seal and one Closer S, which required two hours of additional bed rest. There was no late complication. So, the total success rates were 90.8% (1,423/1,568) in the no-drug group and 88.0% (95/108) in the drug group. These results were not significantly different between the two groups (p = 0.34). In the drug group, the difference of the successful hemostasis rate between the collagen plug devices and the suture-mediated devices was also not statistically significant (92.9% vs. 84.8%, respectively; p = 0.21). CONCLUSION: Arterial closure of the femoral access site with using vascular closure devices is both safe and effective, even in the patients who received heparin, abciximab or thrombolytics.

The Balloon Dilatation and Large Profile Catheter Maintenance Method for the Management of the Bile Duct Stricture Following Liver Transplantation

OBJECTIVE: We wanted to evaluate the therapeutic efficacy of the percutaneous balloon dilatation and large profile catheter maintenance method for the management of patients with anastomotic biliary strictures following liver transplant. MATERIALS AND METHODS: From May 1999 to June 2003, 12 patients with symptomatic benign biliary stricture complicated by liver transplantation were treated with the percutaneous balloon dilatation and large profile catheter maintenance method (1-6 months). The patients were eight males and four females, and their ages ranged from 20 to 62 years (mean age: 44 years). Ten patients underwent living donor liver transplantation and two underwent cadaveric liver transplantation. Postoperative biliary strictures occurred from two to 21 months (mean age: 18 months) after liver transplantation. RESULTS: The initial technical success rate was 92%. Patency of the bile duct was preserved for eight to 40 months (mean period: 19 months) in 10 of 12 (84%) patients. When reviewing two patients (17%), secondary balloon dilatations were needed for treating the delayed recurrence of biliary stricture. In one patient, no recurrent stenosis was seen during the further 10 months follow-up after secondary balloon dilatation. Another patient did not response to secondary balloon dilatation, and he was treated by surgery. Eleven of 12 patients (92%) showed good biliary patency for 8-40 months (mean period: 19 months) of follow-up. CONCLUSION: The percutaneous balloon dilatation and large profile catheter maintenance method is an effective therapeutic alternative for the treatment of most biliary strictures that complicate liver transplantation. It has a high success rate and it should be considered before surgery.

The "Mini-Perc" Technique of Percutaneous Nephrolithotomy with a 14-Fr Peel-away Sheath: 3-year Results in 72 Patients

OBJECTIVE: To assess the efficacy and safety of a "mini-perc" technique of percutaneous nephrolithotomy using a 14-Fr peel-away sheath for the removal of pyelocaliceal stones, and to determine appropriate inclusion criteria. MATERIALS AND METHODS: From July 1999 to June 2002, the medical records and radiographic images of 72 patients who underwent the "mini-perc" technique of percutaneous nephrolithotomy with a 14-Fr peel-away sheath, were reviewed to determine clinical history, stone characteristics, immediate stone free rate, final stone free rate after additional procedures, complications, and hospital stay. We also analyzed the effect of the longest stone diameter, the cumulative longest diameter of stones, the cumulative stone burden, and the stone density on the immediate stone free rate using a Fisher exact test. RESULTS: The only major complication, arterial bleeding, occurred in a patient with Child A liver cirrhosis and was successfully treated by embolization with coils and a gelatin sponge. The immediate stone free rate was 80.6 %, which was significantly influenced by stone diameter but not stone density. The mean hospital stay after the procedure was 3.97 days. CONCLUSION: The "mini-perc" technique of percutaneous nephrolithotomy, which uses the 14-Fr peel-away sheath, is a safe and effective modality for treating renal calculi.

Prospective Comparison of Collagen Plug (Angio-SealTM) and Suture-Mediated (the Closer STM) 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.

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.

The Mid-Term Efficacy and Safety of a Permanent Nitinol IVC Filter (TrapEase)

OBJECTIVE: 1) To evaluate the mid-term efficacy and safety of a permanent nitinol inferior vena cava (IVC) filter; 2) to evaluate filter effectiveness, filter stability and caval occlusion. MATERIALS AND METHODS: A prospective evaluation of the TrapEase IVC filter was performed on 42 patients (eight men, 34 women) ranging in age from 22 to 78 years (mean age 66 years). All patients were ill with a high risk of pulmonary embolism (PE). Indications for filter placement were: 1) deep vein thrombosis with recurrent thromboembolism; 2) and/or free-floating thrombus with contraindication to anticoagulation; and 3) complications in achieving adequate anticoagulation. Follow-up evaluations (mean: 15.4 months, range: 2 to 28 months) were performed at 6- and 12-month intervals after the procedure and included clinical histories, chart reviews, plain film, Doppler ultrasounds, and contrasted abdominal CT scans. RESULTS: In follow-up evaluations, the data analysis revealed no cases of symptomatic PE. There were no cases of filter migration, insertion site thrombosis, filter fracture, or vessel wall perforation. During the study, there was one case of filter thrombosis; early symptomatic thrombosis that was successfully treated in the hospital. Of the 42 subjects, eight died. These deaths were not related to the filter device or the implantation procedure, but to the underlying disease. CONCLUSION: This study demonstrates that the TrapEase permanent IVC filter is a safe and an effective device with low complication rates and is best used in patients with thromboembolic disease with a high risk of PE.

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.

Acute Necrotizing Encephalopathy in Korean Infants and Children: Imaging Findings and Diverse Clinical Outcome

OBJECTIVE: The purpose of our study was to describe acute necrotizing encephalopathy in Korean infants and children, and we sought to evaluate the prognostic factors. MATERIALS AND METHODS: Acute necrotizing encephalopathy was diagnosed in 14 Korean infants and children. We retrospectively analyzed the neuroimaging findings including the follow-up changes. The clinical course of the disease was graded, and we evaluated prognostic factors including age, serum level of the aminotransferase, hemorrhage, and localized atrophy of the brain. RESULTS: This encephalopathy predominantly affected the bilateral thalami (n=14), pons (n=12), and midbrain (n=10) in a symmetrical pattern. Hemorrhage was observed in eight patients (57%). On the follow-up images (n=12), the brain lesions were reduced in extent for all patients, and generalized atrophy was seen in six patients. Localized tissue loss was observed in five patients and a complete resolution occurred for one patient. All the patients survived and two recovered completely; mild (n=6) to severe (n=6) neurological deficits persisted in the remaining 12 patients. The significant prognostic factors identified in this study were the presence of hemorrhage (p = 0.009) and localized atrophy (p = 0.015). CONCLUSION: Acute necrotizing encephalopathy in Korean patients showed the characteristic patterns of the post-infectious encephalopathy as described in the literature. The high survival rate and the relatively favorable clinical course observed for the present study suggest a more diverse spectrum of disease severity than was previously described. The presence of hemorrhage and localized tissue loss on MR images may suggest a poor prognosis.

Selective Intra-Arterial Calcium Stimulation with Hepatic Venous Sampling for Preoperative Localization of Insulinomas

OBJECTIVE: To determine the value of selective intra-arterial calcium stimulation with hepatic venous sampling using serum insulin and C-peptide gradients for the preoperative localization of insulinomas. MATERIALS AND METHODS: Seven consecutive patients [three men and four women aged 15-77 (mean, 42.7) years] with hypoglycemia underwent selective intra-arterial calcium stimulation in conjunction with hepatic venous sampling. Insulin gradients were calculated by an individual blinded to all other preoperative imaging studies and operative findings. In all patients except one, C-peptide gradients were also analyzed. The results were compared with the preoperative findings of ultrasonography, computed tomography, arteriography and endoscopic ultrasonography, as well as with the intraoperative findings of ultrasonography and palpation at surgery. RESULTS: Eight insulinomas (mean diameter, 12.5 mm) were diagnosed after surgery. In six patients, the calcium stimulation test with insulin gradients allowed accurate localization of the pathologic source of insulin secretion. Both C-peptide and insulin gradients substantially increased diagnostic accuracy. In one patient, C-peptide gradients were more helpful than insulin gradients for tumor localization. CONCLUSION: Selective intra-arterial calcium stimulation with hepatic venous sampling is a highly accurate and safe method for the preoperative localization of insulinomas. Additional C-peptide gradients seem to be helpful in assessing tumor location, but further study is needed.

Ethanol Embolization of Arteriovenous Malformations: Results and Complications of 33 Cases

PURPOSE: To assess the effectiveness of ethanol embolization for the treatment of arteriovenous malformation (AVM), and the complications, if any, arising. MATERIALS AND METHODS: Thirty-three patients with AVMs underwent 145 staged sessions of ethanol embolization. AVMs were located in an upper extremity (n=14), a lower extremity (n=10), the pelvis (n=7), the thorax (n=1), or the abdomen (n=1). Eighty-five transcatheter embolizations and 60 direct percutaneous puncture embolizations were performed, and seven patients underwent additional coil embolization of the dilated outflow vein. The therapeutic effectiveness of embolization was evaluated in terms of the extent to which an AVM was obliterated between baseline and the final angiogram. Complications were classified as minor or major. RESULTS: In 13 patients (39%), AVMs were totally obliterated. In eitht patients (24%), more than 75% were obliterated; in three (9%), the proportion was 50-75%; and in four (12%), less than 50%. Five patients (15%), were not treated. The reasons for failure were the difficulty of approaching the nidus due to previous surgical ligation or coil embolization of the feeding artery, the subcutaneous location of an AVM, post-procedural infection, and massive bleeding during the follow-up period. Twenty-one minor complications such as focal skin necrosis or transient nerve palsy developed during 145 sessions of (an incidence of 14%), but these were relieved by conservative treatment. The five major complications arising (3%) were cerebral infarction, urinary tract infection, acute renal failure due to rhabdomyolysis, permanent median nerve palsy, and infection. CONCLUSION: Ethanol embolization by direct percutaneous puncture or using a transcatheter technique is an effective approach to the treatment of an AVM. However, to overcome the considerable number of complications arising, further investigation is required.

Outcome of Tunneled Infusion Catheters Inserted via the Right Internal Jugular Vein

PURPOSE: To assess the outcome of tunneled central venous catheter placement via the right internal jugular vein. MATERIALS AND METHODS: Between June 2001 and May 2002, 670 consecutive Hickman catheters were placed in 654 patients via the right internal jugular vein. The procedural complications arising and follow-up data obtained from May to July 2002 were evaluated. RESULTS: The technical success rate for catheter placement was 99.9% (669/670). Procedural complications were limited to eight cases (1.2%), including three pneumothoraces, one early migration of the catheter, one clinically unimportant air embolism, one catheter injury, one catheter kinking and one primary malpositioning in the azygos vein. Catheter dwelling time ranged from 1 to 407 (mean 107.1) days. During the follow-up period, 416 catheters were removed for various reasons: treatment had ended (n=334), patients declined treatment or their drug regimen was changed (n=16), late complications arose (n=53), or other circumstances intervened (n=13). Late complications included 44 cases of catheter-related infection (6.6%), five of catheter migration (0.7%), two of catheter occlusion (0.3%), one of thrombophlebitis (0.15%), and one of catheter-related right atrial thrombosis (0.15%). Only one instance of symptomatic venous thrombosis or stenosis was noted , namely the one case of thrombophlebitis. CONCLUSION: Because the incidence of subsequent symptomatic venous thrombosis or stenosis is lower, the preferred route for tunneled central venous catheter placement is the right internal jugular vein.

Percutaneous Intervention for Permanent Hemodialysis Access

PURPOSE: To evaluate the effectiveness of percutaneous transluminal angioplasty (PTA) and pulse-spray pharmacomechanical thrombolysis (PSPMT) using urokinase for the management of insufficient hemodyalitic access, and to identify contributory patency-related factors following interventional procedures. MATERIALS AND METHODS: Between August 1995 and July 2001, 105 cases of insufficient hemodyalitic access involving 38 artificial arteriovenous fistulae (AVF) and 67 graft arteriovenous fistulae (AVG) were treated interventionally. The patients underwent PTA alone in 53 cases and PSPMT combined with PTA in 47, and procedural success and long-term patency were evaluated in terms of a patient's age and sex, the presence of diabetes, the location of access, the type of AVG, the draining vein of AVG, the presence of central vein stenosis, the degree of residual stenosis, and the method of interventional procedure, and contributory factors were thus identified. RESULTS: The overall technical success rate of interventional management was 83.8% (88/105), while the overall primary patency rate was 58.7+/-5.2% at 6 months, 43.0+/-6.0% at 1 year, and 18.1+/-6.0% at 2 years. In AVF/AVG groups, primary patency rates were 55.9+/-9.2%/57.8+/-6.5% at 6 months, 45.8+/-10.0%/42.7+/-8.4% at 1 year, and 21.8%+/-9.8%/18.9+/-6.5% at 2 years. The overall secondary patency rate was 40.0+/-8.1% at 2 years. No contributory factors were found (95% confidence level), though patency of access decreased when residual stenosis was more than 30% (p=0.054). CONCLUSION: Interventional management of insufficient hemodyalitic access has high success and patency rates, and is an effective primary method. There appear to be no contributory factors, though residual stenosis of more than 30% tends to decrease the patency of hemodialytic access.