Radiologic and clinical results of transarterial ethanol embolization for renal angiomyolipoma

OBJECTIVE

We sought to determine the efficacy and safety of selective arterial embolization for renal angiomyolipoma (AML) using ethanol alone or ethanol with additional embolic materials and to analyze the factors influencing safety and efficacy.

METHODS

One hundred nineteen AMLs treated with embolization were included retrospectively during a 15-year period. Technical, radiologic, and clinical success were recorded and risk factor analysis was performed. Complications on follow-up images, post-embolization syndrome (PES), major complications, and changes in renal function were also evaluated.

RESULTS

Technical success was achieved in 106 of 119 tumors. Tumor size significantly decreased after treatment (reduction rate: 55%). Significant risk factors for tumor reduction included tumor enhancement on preprocedural CT and residual tumor staining. Radiologic success was achieved in 114 of 119 tumors (risk factor: residual tumor staining), and clinical success was achieved in 22 of 23 patients. Complications on follow-up images occurred in 40 of 119 tumors, and PES occurred in 53 of 104 patients. No major complications occurred. There were no cases of renal function impairment.

CONCLUSION

Selective transarterial embolization using ethanol alone or ethanol with additional embolic materials reduced AML size, alleviated symptoms, and can be performed safely without permanent impairment.

KEY POINTS

• Percutaneous transarterial ethanol embolization reduces AML size and alleviates symptoms. • Embolization can be performed safely without permanent impairment of renal function.

Percutaneous radiologic gastrostomy with single gastropexy: outcomes in 636 patients

OBJECTIVES

This study aimed to assess the technical success and overall complication rate of percutaneous radiologic gastrostomy (PRG) with single gastropexy using a separate tract from that used for tube placement.

METHODS

From January 2014 to December 2018, 636 patients (469 men, 167 women; mean age 66.8 years; age range, 22-98 years) underwent PRG using single gastropexy at a tertiary center. Preprocedural computed tomography (CT) was recommended if there were no data on the location of the stomach on previous CT. After a single anchor was applied, the PRG tube was inserted through a separate tract from that used for tube placement. The technical success rate and major and minor complications were retrospectively reviewed. The number of patients and percentages were used as descriptive statistics for evaluating the complication rate.

RESULTS

The technical success rate of PRG with single gastropexy was 99.2% (631/636). There were 32 complications among the 631 procedures. There were 19 (3.0%) major complications, including peritonitis (n = 7), migration (n = 5), infection (n=4), malposition (n = 2), and bleeding (n = 1). There were 13 (2.1%) minor complications, including local infection (n = 11), malfunction (n = 1), and pneumoperitoneum (n = 1). The overall complication rate within 30 days of PRG placement was 4.1% (26/631).

CONCLUSIONS

PRG with single gastropexy using a separate tract from that used for tube placement is technically feasible with a low complication rate.

KEY POINTS

• Percutaneous radiologic gastrostomy with single gastropexy using a separate tract from that used for tube placement is technically feasible. • Complications including peritonitis and bleeding were comparatively low with the conventional technique.

Selective Versus Non-selective Transarterial Chemoembolization via the Intercostal Artery for the Treatment of Hepatocellular Carcinoma

PURPOSE

To report the 1-month tumor response and safety of selective transarterial chemoembolization (TACE) via the intercostal artery (ICA) for the treatment of hepatocellular carcinoma (HCC) in comparison with those of non-selective TACE.

METHODS

This retrospective study included 79 HCC patients who underwent TACE via the ICA selectively (selective TACE group; n = 26) or non-selectively (non-selective TACE group; n = 53) between January 2001 and December 2016. Selective TACE was defined when TACE was performed with selective catheterization of the tumor feeding branch of the ICA. TACE performed without selective catheterization of the tumor feeding branch was defined as non-selective TACE. One-month target and overall tumor responses and complications of the two groups were compared. Univariate and multivariate analyses were performed to identify prognostic factors.

RESULTS

Selective TACE group showed better 1-month target and overall tumor responses and lower frequency of complications than non-selective TACE group (P = .007, P = .018, and P < .001, respectively). Performing selective TACE was the only significant favorable factor for better target and overall tumor responses (P = .001 and P = .028, respectively). In univariate analysis for complications, serum α-fetoprotein > 200 ng/mL and non-selective TACE were statistically significant. However, multivariate analysis showed that performing non-selective TACE was the only significant risk factor (odds ratio 13.56; 95% confidence interval 3.51-52.5; P < .001).

CONCLUSION

Compared to non-selective TACE via the ICA, selective TACE via the ICA for the treatment of HCC can achieve better tumor response and safety.

Combined transarterial chemoembolization of the right inferior phrenic artery and radiofrequency ablation for small hepatocellular carcinoma near the diaphragm: its efficacy and safety

PURPOSE

The purpose of the study is to report the efficacy and safety of combined transarterial chemoembolization (TACE) of the right inferior phrenic artery (IPA) and radiofrequency ablation (RFA) for small hepatocellular carcinoma (HCC) near the diaphragm supplied by the right IPA.

METHODS

From July 2009 through April 2015, 11 patients with small (≤ 3 cm) HCC near the diaphragm, which was infeasible for ultrasound-guided RFA and supplied by the right IPA, received TACE of the right IPA and subsequent RFA in one session. The safety and therapeutic efficacy, including technique effectiveness and local tumor progression (LTP), were evaluated.

RESULTS

Technique effectiveness was achieved in all the 11 patients (100%). During average follow-up period of 39.2 months (range 13-89 months), LTP occurred in none of the 11 patients. There were twelve minor complications in eight patients, including right shoulder pain (n = 4), right pleural effusion (n = 2), diaphragmatic thickening (n = 2), transient lung change (n = 2), subsegmental intrahepatic bile duct stricture (n = 1), and subsegmental hepatic infarction (n = 1). No major complications were encountered CONCLUSION: Combined TACE of the right IPA and RFA can be a safe and effective treatment for small HCC near the diaphragm that is supplied by the right IPA.

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.

A novel, ring-connected stent versus conventional GI stents: comparative study of physical properties and migration rates in a canine colon obstruction model

BACKGROUND

Migration of stents is one of the most common adverse events in covered stent placement in GI tract obstruction.

OBJECTIVE

To compare physical property and migration rates in a canine colon obstruction model among a novel stent and conventional stents.

DESIGN

Comparative physical test and animal study.

SETTING

Medical device testing laboratory and animal laboratory.

SUBJECTS

Mongrel dogs (N=26).

INTERVENTIONS

Surgical colon obstruction followed by placement of a novel (n=13) or conventional (n=13) stent.

MAIN OUTCOME MEASUREMENTS

Physical properties, migration, and adverse events.

RESULTS

The novel stent showed better flexibility, as in a physical test of longitudinal compressibility and axial force, than did conventional stents, and it withstood the fatigue test for 10 days. In terms of radial force and tensile strength, the novel stent showed the same or better results than conventional stents. In a canine colon obstruction model, the migration rate of a novel stent was significantly lower than that of a conventional stent (2/13, 15.4% vs 8/13, 61.5%; P=.008).

LIMITATIONS

Animal study of limited size.

CONCLUSION

The novel, ring-connected stent is more flexible and more resistant to migration than the conventional stents.

Efficacy of RECIST and mRECIST criteria as prognostic factors in patients undergoing repeated iodized oil chemoembolization of intermediate stage hepatocellular carcinoma

BACKGROUND

Given that transarterial chemoembolization (TACE) is usually a repeated procedure for treatment of hepatocellular carcinoma (HCC), repeated radiologic response assessments rather than a single time point assessment may have different clinical implications through the repeated course of TACE.

PURPOSE

To evaluate the efficacy of RECIST and mRECIST criteria as a survival predictor across early time points after repeated TACE of HCC.

MATERIAL AND METHODS

Ninety-eight patients with intermediate stage HCC received repeated iodized oil TACE. Treatment response was assessed according to RECIST and mRECIST criteria at 1, 3, and 6 months after initial TACE. Cox proportional model was used for survival analysis and the predicting power of each time point response was evaluated with C-statistics and time-dependent area under the receiver operating characteristic curve (AUC). Inter-method agreement was assessed with the κ coefficient.

RESULTS

mRECIST was not applicable in 15 patients because of patchy uptake of iodized oil after TACE. On multivariate analysis, responders at 6 months by RECIST, responders at 3 months, and 6 months by mRECIST showed better survival than non-responders (P < 0.05). Predicting power of response criteria improved over time and mRECIST at 6 months showed the best performance. The degree of agreements was poor or fair between RECIST and mRECIST.

CONCLUSION

mRECIST predicted long-term survival as early as 3 months after TACE of intermediate stage HCC. The predicting power of the uni-dimensional response criteria tended to be stronger over time.

Transarterial chemoembolization as first-line therapy for hepatocellular carcinomas infeasible for ultrasound-guided radiofrequency ablation: a retrospective cohort study of 116 patients

BACKGROUND

Ultrasound (US)-guided radiofrequency ablation (RFA) is frequently infeasible even for very early or early stage hepatocellular carcinoma (HCC) due to various reasons such as inconspicuous tumors or absence of a safe electrode path and the infeasibility rate is reportedly as high as 45%. In such cases, transarterial chemoembolization (TACE) is a commonly practiced alternative.

PURPOSE

To analyze long-term outcomes including tumor progression patterns and factors contributing to survival of patients who received TACE as the first line of therapy for very early or early stage HCC infeasible for US-guided RFA.

MATERIAL AND METHODS

From October 2006 through October 2009, 116 patients with very early or early stage HCCs underwent the first-line therapy TACE after their tumors were deemed infeasible for RFA. Long-term survival rates were calculated and prognostic factors were assessed by univariate and multivariate analyses. The patterns and rates of tumor progression or recurrence were also evaluated.

RESULTS

The 1, 3, and 5-year survival rates of the whole cohort were 94.7%, 68.4%, and 47.2% with a mean overall survival of 53.1 months (95% CI: 48.2-58.0). Preserved liver function with Child-Pugh class A was the only independent factor associated with longer survival. The most common first tumor progression pattern was intrahepatic distant recurrence. The cumulative rates of local tumor progression and intrahepatic distant recurrence at 1, 3, and 5 years were 33% and 22%, 52% and 49%, and 73% and 75%, respectively.

CONCLUSION

TACE is a viable first-line treatment of HCC infeasible for RFA, especially when liver function was preserved.

Uterine artery embolization for emergent management of postpartum hemorrhage associated with placenta accreta

BACKGROUND

Although uterine artery embolization (UAE) is a well-recognized alternative treatment for postpartum hemorrhage (PPH) with a high clinical efficacy, the reported success rate of UAE for PPH associated with placenta accreta (PA) is lower. Recently, with advances in techniques and expertise, a few studies have reported favorable results of UAE in controlling PPH in the setting of PA.

PURPOSE

To evaluate the efficacy of UAE in the emergent management of intractable PPH associated with PA.

MATERIAL AND METHODS

Seventeen consecutive patients who underwent emergent UAE for the management of PPH associated with PA were included in this retrospective study. Medical records were reviewed regarding the delivery and UAE procedure. Follow-up gynecologic outcomes after UAE were obtained by telephone interview.

RESULTS

UAE successfully controlled PPH in 14 patients (82.4%). Three patients underwent hysterectomy after UAE failed to stop the bleeding. All hysterectomy cases were accompanied by uterine atony or total placenta previa. Relevant gynecologic findings were obtained from 10 patients; three patients were breastfeeding and seven patients resumed normal menstruation, including one pregnancy.

CONCLUSION

UAE appears to be a safe and effective means by which to control PPH associated with PA. PA complicated by uterine atony or placenta previa may be at increased risk of UAE failure.

Heavily calcified occlusive lesions of the iliac artery: long-term patency and CT findings after stent placement

PURPOSE

To evaluate the influence of heavy calcification on iliac arterial stent expansion and patency and to define the spatial relationship between the stent and heavy calcifications on computed tomography (CT).

MATERIALS AND METHODS

Thirteen patients (11 men, two women; mean age, 66.5 y) with 14 heavily calcified iliac arteries received primary stent treatment between 1998 and 2008. Anatomic success was defined by less than 30% residual stenosis on final follow-up CT angiography. Hemodynamic success was defined as an increase in the ankle-brachial index (ABI) of at least 0.15 versus baseline. Clinical success was defined by achievement of clinical improvement of at least one clinical category. Stent patency; anatomic, hemodynamic, and clinical success rate; morphology of heavy calcifications; calcium score; and stent geometry were evaluated.

RESULTS

Stents were successfully inserted in all cases. During a mean follow-up of 33.6 months (range, 8-55 mo), the stent-implanted iliac arteries remained anatomically patent in all patients on final follow-up. The anatomic, hemodynamic, and clinical success rates were 28.6%, 60%, and 78.6%, respectively. Mean ABIs were 0.68 ± 0.22 before the procedure and 0.91 ± 0.23 after the procedure (P = .021). Mean luminal stenosis measurements were 77.9% before the procedure and 47.9% after the procedure (P = .008).

CONCLUSIONS

Iliac stents in heavily calcified lesions showed hemodynamically significant residual stenosis in a considerable number of cases. However, stent patency was not affected even with incomplete expansion of the stent.

Ischemic liver injuries after hepatic artery embolization in patients with delayed postoperative hemorrhage following hepatobiliary pancreatic surgery

BACKGROUND

Many collateral pathways to the liver are dissected during hepatobiliary pancreatic surgery and, if the arterial bleeding is massive and a hematoma becomes larger, the adjacent portal vein can be compressed with impairment of the portal venous flow.

PURPOSE

To evaluate the frequency and severity of ischemic liver injuries after hepatic artery embolization in patients with delayed postoperative arterial hemorrhage after hepatobiliary pancreatic surgery.

MATERIAL AND METHODS

Eighteen patients undergoing proper or common hepatic artery embolization for delayed postoperative arterial hemorrhage after hepatobiliary pancreatic surgery achieved hemostasis. To evaluate the frequency and severity of ischemic liver injuries, the liver enzyme levels and CT findings before and after hepatic artery embolization were retrospectively compared and the clinical outcomes after hepatic artery embolization were analyzed. Angiographic findings were also analyzed to reveal any association with development of ischemic liver injuries after hepatic artery embolization.

RESULTS

Ischemic liver injuries were observed in 15 (83%) of 18 patients undergoing hepatic artery embolization for postoperative hemorrhage. Injuries included hepatic infarction combined with abscess in one (5%) patient, hepatic infarction in 12 (67%) patients, and transient hepatic ischemia/dysfunction in two (11%). As for the extent of hepatic infarction, lobar infarction developed in two patients and subsegmental infarction in 11. One patient with right hepatic lobar infarction died of hepatic failure 11 days after hepatic artery embolization. In the other 14 patients with ischemic liver injuries, the elevated liver enzymes returned to baseline levels within two weeks. All of the four patients with portal vein stenosis, four patients with no hepatic arterial flow on post-embolization angiogram, and one patient with both had hepatic infarction after hepatic artery embolization. No ischemic liver injuries developed after hepatic artery embolization in three patients with no portal vein stenosis and bilobar hepatic arterial flow via the left hepatic artery aberrantly arising from the left gastric artery or from the common hepatic artery.

CONCLUSION

Ischemic liver injuries can develop in most patients undergoing hepatic artery embolization for postoperative arterial hemorrhage after hepatobiliary pancreatic surgery; hepatic infarction appears to be the most frequent type of ischemic liver injury. Hepatic artery embolization for postoperative arterial hemorrhage after hepatobiliary pancreatic surgery may carry a great risk of ischemic liver injury if a patient has portal vein stenosis or no aberrant hepatic artery.

Single-bolus regional chemotherapy with doxorubicin versus chemoembolization in a rabbit VX2 tumor model

PURPOSE

This study evaluates the anti-tumor effect of regional chemotherapy compared with chemoembolization in an animal model.

MATERIALS AND METHODS

Twenty-one rabbits bearing VX2 liver tumors were divided into the following four groups: (a) the transarterial (TA) group (n=6) received a transarterial injection of doxorubicin through the hepatic artery (1 mg/kg); (b) the transarterial and transportal (TAP) group (n=6) received injections of doxorubicin through both the hepatic artery (1 mg/kg) and the portal vein (1 mg/kg); (c) the transarterial chemoembolization (TACE) group (n=6) received a transarterial injection of doxorubicin (1 mg/kg) followed by gelatin sponge embolization; and (d) the control group (n=3) received no treatment. With the use of computed tomography, tumor growth rates were calculated and microscopic examinations were performed to evaluate the extent of tumor necrosis.

RESULTS

Seven days after each treatment, the mean tumor growth rates were 216.7%±189.0% in the TA group, 77.1%±73.9% in the TAP group, and 489.5%±352.1% in the control group; there were no significant differences in tumor growth rates (P = 0.057). The tumor growth rate of the TACE group could not be evaluated due to extensive liver necrosis. The mean tumor necrosis rates were 41.9%±11.5% in the TA group, 51.4%±11.1% in the TAP group, 94.7%±3.5% in the TACE group, and 29.3%±6.7% in the control group; the TACE group showed significantly higher tumor necrosis than any other groups.

CONCLUSION

Single session regional chemotherapy has limited anti-tumor effects when compared with TACE in the rabbit VX2 tumor model.

The efficacy of combined transarterial chemoembolization and 3-dimensional conformal radiotherapy for hepatocellular carcinoma with main portal vein thrombosis

BACKGROUND/AIMS

The goal of this study was to evaluate the efficacy of combined therapy with TAE and 3-dimensional conformal radiotherapy (3D-CRT) for HCC with main portal vein thrombosis (MPVT).

METHODOLOGY

We retrospectively reviewed the medical records of 18 patients who had an unresectable HCC with MPVT and underwent combined TAE and 3D-CRT. Treatment responses for the main tumor and the MPVT were assessed. In addition, patient survival and the prognostic factors associated with survival were analyzed.

RESULTS

The overall survival for the 18 patients was 13.0 +/- 8.5 months. For the main tumor response, 8 patients were responders and 10 were non-responders. For the MPVT, an objective response was observed in 10 out of the 18 cases. The univariate analysis revealed that the pretreatment AFP level, presence of regional lymph node metastasis, main tumor response and the MPVT response were prognostic factors for survival; however, these factors failed to reach significance on the multivariate analysis. Most of the treatment-related complications were resolved within 4 weeks. No patient had clinical evidence of progressive hepatic insufficiency related to the treatment.

CONCLUSIONS

Combined therapy with TAE and 3D-CRT was safe and effective for the treatment of HCC patients with MPVT and might provide a survival benefit.

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.

The TransAtlantic InterSociety Consensus (TASC) Classification System in Iliac Arterial Stent Placement: Long-term Patency and Clinical Limitations

PURPOSE

To evaluate the long-term patency of iliac arterial stent placement according to individual TransAtlantic Intersociety Consensus (TASC) stages and demonstrate the limitations of TASC classification for iliac arterial disease.

MATERIALS AND METHODS

Retrospective analysis of 218 patients who underwent iliac arterial stent placement revealed 295 stents were placed in 260 limbs. Iliac lesions of patients were classified according to the TASC classification on initial angiography but patients having bilateral different staged lesion were classified with limb based TASC classification. Analysis was performed based on the number of treated limbs not on the number of patients. Stent patency of individual TASC stages was analyzed by Kaplan-Meier methods and were compared by the log rank test.

RESULTS

The technical success rate was 99%. 171 patients (80%) were classified under a single TASC category, however, 44 patients (20%) with bilateral iliac lesions could not be classified under a single TASC stage. The number of patients and limbs in each TASC group was: TASC A (88/97), TASC B (91/97), TASC C (32/48), and TASC D (16/18). The 1, 3 and 5 year primary patencies of the iliac arterial stent for TASC A were 96%, 84%, and 81%; TASC B were 95%, 85%, and 85%; TASC C were 94%, 94%, and 78%; and TASC D were 93%, 74%, and 74%, respectively. Four TASC groups were not statistically different for primary patency rates (P < .03).

CONCLUSION

The patency of iliac arterial stents did not show statistically significant difference among TASC stages. TASC system is limited for patient classification with bilateral iliac arterial disease [corrected]

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.

Hepatic intra-arterial injection of 3-bromopyruvate in rabbit VX2 tumor

PURPOSE

To evaluate the antitumoral effects of an intra-arterial injection of 3-bromopyruvate (3-BrPA) on liver VX2 tumor in rabbits.

MATERIAL AND METHODS

Twenty rabbits with surgically implanted liver VX2 tumors were used. The rabbits were divided into three groups: a control, a saline, and a 3-BrPA group. Four rabbits were not treated at all, and they served as the control group. The saline group (n = 6) received only intra-arterial saline injection. The 3-BrPA group (n = 10) received an intra-arterial injection of 3-bromopyruvate through the hepatic artery. The delivered amounts of 3-bromopyruvate were as follows: 25 ml of 0.5 mM in six rabbits, 25 ml of 1.0 mM in two rabbits, and 25 ml of 2.0 mM in two rabbits. Four days after intra-arterial injection, the rabbits were sacrificed and histopathologic analysis of the explanted livers was performed with comparison of the tumor necrosis ratio (a percentage of the necrotic area versus the entire tumorous area) in each group.

RESULTS

The mean tumor necrosis ratio was 12.5+/-4.2%, 44.8+/-24.7%, and 49.4+/-14.3% in the control, saline, and 3-BrPA groups, respectively. Between the control and the saline group, and between the control and the 3-BrPA group the mean tumor necrosis ratio appeared to be significantly different (P<0.05). However, there was no statistical difference in the mean tumor necrosis ratio between the saline and the 3-BrPA group (P = 0.416).

CONCLUSION

A single session of intra-arterial injection of 3-BrPA showed no better results in terms of tumor necrosis than that of saline injection in a rabbit VX2 tumor model.

Milan criteria are useful predictors for favorable outcomes in hepatocellular carcinoma patients undergoing liver transplantation after transarterial chemoembolization

AIM: To evaluate whether the Milan criteria are useful in patients with hepatocellular carcinoma (HCC) who received transarterial chemoembolization (TACE) before liver transplantation (LT).

METHODS: Thirty-six HCC patients who fulfilled the Milan criteria after having received TACE and subsequently underwent LT were included (TACE + LT group) in the study. As controls, 21 patients who also met the Milan criteria and underwent LT without prior treatment were selected (LT group). Post-LT clinical outcomes, such as HCC recurrence, survival rate, and histologic features of explanted livers, were compared between the two groups.

RESULTS: Baseline characteristics were not different between the two groups. Pre-LT maximal tumor diameter in TACE + LT group was similar to that of LT group (2.0 ± 0.6 cm vs 2.3 ± 0.9 cm; P = 0.10). Post-LT histologic findings also revealed similar maximal tumor diameter in the two groups (2.4 ± 1.4 cm vs 2.3 ± 0.9 cm; P = 0.70). Explanted livers showed similar incidence of unfavorable pathologic features. The morality within 60 d after transplantation was not different between the two groups (8.3% vs 9.5%; P = 0.99). Post-LT 5-year survival rate (57% vs 74%; P = 0.70) and cumulative recurrence rate (8.3% vs 4.8%; P = 0.90) were not significantly different between the two groups.

CONCLUSION: The Milan criteria are still a useful selec-tion criteria showing favorable outcomes in HCC patients receiving TACE before LT.

Diaphragmatic Weakness after Transcatheter Arterial Chemoembolization of Inferior Phrenic Artery for Treatment of Hepatocellular Carcinoma

PURPOSE

To prospectively assess the diaphragmatic anatomic and functional consequences of transcatheter arterial chemoembolization (TACE) of the inferior phrenic artery in patients with hepatocellular carcinoma.

MATERIALS AND METHODS

Informed consent and institutional review board approval were obtained. Fifteen patients (13 men, two women; mean age, 52 years; age range, 22-61 years) who underwent TACE of the inferior phrenic artery for treatment of hepatocellular carcinoma were enrolled. The right inferior phrenic artery was embolized in 14 patients, and the left inferior phrenic artery was embolized in one patient. Chest radiography, fluoroscopy, computed tomography (CT), and pulmonary function tests were performed before and after TACE of the inferior phrenic artery. The post-TACE examinations were performed 2-3 months after TACE, and the results were compared with those of the pre-TACE examinations. A paired t test or the Wilcoxon signed rank test was used for statistical analyses.

RESULTS

At chest radiography and fluoroscopy, six of 15 patients (40%) had both elevation and movement abnormality of the ipsilateral hemidiaphragm after TACE of the inferior phrenic artery. The mean (+/- standard deviation) diaphragmatic thickness on CT scans changed from 9.11 mm +/- 3.02 to 7.67 mm +/- 2.27 after TACE (P = .048). The mean vital capacity also was significantly decreased after TACE, from 91.87% +/- 18.52 to 82.27% +/- 16.94 of the predicted value (P = .006). The decreases in diaphragmatic thickness and vital capacity were most pronounced in the patients with abnormal findings at chest radiography and fluoroscopy.

CONCLUSION

After TACE of the inferior phrenic artery, a substantial portion of patients showed functional and anatomic evidence of diaphragmatic weakness.

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.

Iatrogenic Aorto-Cisterna Chyli Fistula During Percutaneous Balloon Aortoplasty in a Patient with Takayasu’s Arteritis: A Case Report

We present a case of iatrogenic aorto-cisterna chyli fistula that developed during percutaneous transluminal aortoplasty in a 16-year old girl with Takayasu's arteritis. The aorto-cisterna chyli fistula was angiographically confirmed and treated using a stent-graft, which successfully occluded the fistula. Her claudication then improved, although follow-up CT angiography at 10 months revealed mild recurrent aortic stenosis.

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 (< or = 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.

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-Seal; the suture-mediated closure device was The Closer S) 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.

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.

Use of the Right External Jugular Vein as the Preferred Access Site When the Right Internal Jugular Vein Is Not Usable

PURPOSE

The present study describes the authors' experience with central venous access through the right external jugular vein (EJV) when the right internal jugular vein (IJV) is not available.

MATERIALS AND METHODS

A retrospective study of 23 patients in whom a central venous catheter placement was attempted via the right EJV was conducted. The reasons for catheterization via the right EJV included clinically silent occlusion of the right IJV (n = 17), localized skin infection overlying the right IJV related to a previous catheterization (n = 3), presence of an existing Hickman catheter in the right IJV (n = 1), and concern regarding the risk of catheter-related infection secondary to right IJV catheterization in patients with a tracheostomy tube device adjacent to the presumed site of right IJV catheterization (n = 2). Technical success, procedural complications, and follow-up results including catheter dwell time and delayed or late complications (eg, symptomatic venous thrombosis, catheter-related infection, and catheter malfunction) were assessed. Adverse events were expressed as events per 100 catheter-days of use.

RESULTS

Technical success was achieved in 22 of 23 patients (96%). There were no procedural complications. The catheter dwell time ranged from 2 to 182 days, with a mean dwell time of 62.7 days. There were four delayed or late complications (three catheter-related infections, 0.22 per 100 catheter-days; one catheter malfunction, 0.07 per 100 catheter-days). No cases of symptomatic venous thrombosis were noted.

CONCLUSION

The right EJV is an acceptable and preferred access site when the right IJV is not available for central venous catheterization.

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.

Salvage of immature arteriovenous fistulas with percutaneous transluminal angioplasty

The purpose of this study was to assess the value of percutaneous transluminal angioplasty (PTA) for the salvage of arteriovenous fistulas (AVFs) that fail to mature. From November 1998 to February 2003, 19 patients who were treated with PTA due to immature forearm AVFs were selected. Fistulography and PTA were performed via a retrograde transvenous approach after direct puncture of the fistular vein. Technical success was defined as less than a 30% residual stenosis, whereas clinical success was defined as the ability to perform at least one session of normal hemodialysis after PTA. Findings of fistulograms, success rates of PTA, and patency rates were evaluated. On initial fistulograms, stenoses were observed in all cases and 68% (13/19) of the stenoses were located in the perianastomotic area of these immature AVFs. The initial technical success rate was 84% (16/19). Technical failures comprised two patients with diffuse narrowing and segmental thrombosis of the cephalic veins and one case of elastic recoil of the anastomotic site stenosis after PTA. Two patients were immediately lost on follow-up. The remaining 14 cases underwent successful hemodialysis 0 to 33 (mean = 15) days after PTA, showing 74% (14/19) clinical success. Although accessory branch veins were noted in most cases (74%, 14/19), leaving them alone did not affect the maturation of AVFs following PTA. There was no significant procedural or late complication. Primary and secondary patency rates at 1 year were 61 and 82%, respectively. For those AVFs that failed to mature, there were stenoses along their vascular courses as underlying causes. For the percutaneous procedure, the retrograde transvenous approach was a reasonable one. As PTA is effective and quick for the salvation of immature AVFs, it can be considered a primary method for salvaging these immature AVFs.

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.

Ethanol embolization of arteriovenous malformations: interim results

PURPOSE

To assess retrospectively the interim results and the complications of ethanol embolization treatment of arteriovenous malformations (AVMs).

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.

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.

Use of double-occlusion balloon catheter: preoperative portal vein embolization for induction of future remnant liver hypertrophy

PURPOSE

To evaluate the efficacy and safety of using double-occlusion balloon catheters in preoperative portal vein embolization (PVE) to induce future remnant liver hypertrophy.

MATERIALS AND METHODS

PVE was achieved with gelatin sponges by using double-occlusion balloon catheter in seventeen patients with hepatobiliary malignant tumors. The ipsilateral approach was used in thirteen patients and the contralateral approach in four patients due to large size of tumor in the right hepatic lobe. Surgery was performed in 15 patients, 14-27 days (mean, 21.9 days) after PVE. Computed tomographic liver volumetric studies were performed before embolization and before surgery. The changes in aspartate aminotransferase (AST), alanine aminotransferase (ALT), prothrombin time (PT), and total bilirubin levels before and after the PVE were evaluated. Complications were evaluated after PVE.

RESULTS

PVE using double-occlusion balloon catheter was successful in all cases, irrespective of approach technique. The future remnant liver (FRL) volumes were 251-920 cm3 (mean, 437 cm3) before PVE and 281-1042 cm3 (mean, 555 cm3) after PVE. The mean increase in the volume of the FRL was 28.6%; this represented 37% of the preresection volume of the liver. Clinical and biologic tolerance of PVE was mandatory. There were no complications.

CONCLUSIONS

PVE using the double-occlusion balloon catheter is safe and well-tolerated and can be performed technically with ease. This hypertrophy allows hepatectomy to be performed safely when the FRL volume is initially insufficient in patients with hepatobiliary tumors.

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.

First human trial of pancreatic islet allo-transplantation in Korea--focus on re-transplantation

Over the past 20 years, allo-transplantation of islet or whole pancreas for reaching and sustaining near-normoglycemia, as close as possible to the physiological model, have been undertaken. As previously known, even though islet transplantation is possible as a safe re-transplant, it is not well known whether re-transplantation of islets is suitable for patients who have lost the grafted islet function. We have performed a human islet allo-transplantation and re-transplantation on an IDDM patient for the first time in Asia and Korea. The recipient was a 32-year-old male and his insulin requirement was 75-85 U per day. After islet transplantation, the basal C-peptide increased from 0.6 to 2.1 ng/ml and insulin requirement decreased from 80 to 36 U per day, indicating that the grafted islets were functional. However, the grafted islets lost function 70 days after the transplantation. So, we performed re-transplantation of the islets. After the re-transplantation, the glucose profile became more stable and frequent episodes of severe hypoglycemia completely disappeared. His severe neuropathic pain improved dramatically and he could engage his ordinary daily life without any antineuropathic drugs. The success of this re-transplantation is one step closer to becoming a viable alternative for the millions of individuals who are suffering from diabetes.

Malignant obstruction of gastric outlet and duodenum: palliation with flexible covered metallic stents

PURPOSE

To assess the usefulness of flexible covered metallic stents in the palliation of malignant obstruction of the gastric outlet and duodenum.

MATERIALS AND METHODS

Twenty-four consecutive patients with malignant obstruction of the gastric outlet (n = 22) or duodenum (n = 2) underwent palliative treatment with self-expandable flexible covered metallic stents. Fourteen patients had advanced gastric carcinoma at the antrum and/or pylorus, and eight had obstruction at the anastomosis site of previous gastrojejunostomy. Complications and clinical status were investigated during the study period.

RESULTS

The technical success rate was 75% (18 of 24 patients). Twenty-one stents were placed in 18 patients by using an introducer 6 (n = 7) or 8 mm (n = 14) in diameter. The mean follow-up period was 3.4 months (range, 1 week to 9 months). Symptoms improved in 12 (67%) patients after the procedure. There was no change in symptoms in five and a decrease in one. Twelve patients died during the follow-up period (mean survival, 4.3 months). The complication rate was 25% (six of 24 patients), including stent migration (n = 5) and fracture (n = 3).

CONCLUSION

Flexible covered metallic stent placement can be useful for palliation in patients with malignant obstruction of the gastric outlet or duodenum.

Mediastinal interfaces and lines in children: radiographic-CT correlation

BACKGROUND

Various mediastinal interfaces and lines are well known in adults, but not fully understood in children.

OBJECTIVE

To review the mediastinal interfaces and lines on plain radiographs in the paediatric age group with CT correlation.

MATERIALS AND METHODS

Soft copies of 195 sets of CT examinations and concurrent chest radiographs in 180 paediatric patients (age 1 month to 15 years) were retrospectively reviewed. The frequency of visualisation and the anatomical basis of the mediastinal interfaces and lines were assessed. The evaluated mediastinal interfaces and lines were superior vena cava interface, descending aorta interface, left paraspinal interface, azygoesophageal recess interface, right paratracheal stripe, anterior junction line and posterior junction line.

RESULTS

Chest radiographs showed the SVC interface in 161, the descending aorta interface in 155, the left paraspinal interface in 98, the azygoesophageal recess in 94, the right paratracheal stripe in 53, the anterior junction line in 15 and the posterior junction line in 10. Non-visualisation of mediastinal interfaces and lines on plain radiographs was explained by normal anatomical difference compared with the adult and underlying intrathoracic abnormalities when they were correlated with CT. The frequency of visualisation of the SVC interface, descending aortic interface, left paraspinal interface and azygoesophageal recess fluctuated with age, while the frequency of the right paratracheal stripe, anterior junction line and posterior junction line increased with age.

CONCLUSIONS

Awareness of the frequency of visualisation and the anatomical basis of the mediastinal interfaces and lines in paediatric patients may be helpful for interpretation of chest radiographs.

Malignant esophagogastric junction obstruction: palliative treatment with an antireflux valve stent

The authors assessed the efficacy of an antireflux valve stent in the palliation of malignant esophagogastric junction (EGJ) obstruction after in vitro testing of the stent. Seventeen patients with inoperable malignant EGJ obstruction were treated. Antireflux valves, made of three polyurethane leaflets, were attached to the distal part of the stent to prevent reflux. When the flow rate of normal saline was 100 mL/sec in the forward direction, the valve fully opened at a pressure of 10 mm Hg. When the flow rate of normal saline was 0.35 mL/sec in the backward direction, the valve nearly completely closed at a pressure of 10 mm Hg. Stent placement was successful in all patients without complications. The median dysphagia score decreased significantly, from 3.0 (dysphagia to liquids) to 1.0 (dysphagia to normal solid food) (P < .0005). No patients experienced reflux symptoms. There was one case of stent migration. A valve stent that can prevent major reflux is an effective device for the palliation of malignant EGJ obstruction.

Opacification of the intrahepatic portal veins during CT hepatic arteriography

PURPOSE

The purpose of this study was to ascertain the cause of opacification of the portal veins during CT hepatic arteriography (CTHA).

METHOD

A total of 155 consecutive patients with hepatocellular carcinoma were evaluated with CTHA as preoperative staging. The opacification of the portal veins during CTHA was categorized as opacification of the main portal vein, right or left branches of the main portal vein (generalized), and segmental or subsegmental portal veins (localized). Hepatic angiography was compared and possible causes were evaluated.

RESULTS

One hundred eight (70%) of 155 patients showed intrahepatic portal vein opacification at CTHA: generalized in 60 patients (39%) and localized in 48 patients (31%). Intrahepatic causes were arterioportal shunts due to hepatocellular carcinoma in 20 (19% of 108 patients), previous liver biopsy in 9 (8%), and portal vein thrombosis in 4 (4%). Extrahepatic cause was counted in 57 cases (53%) and was due to inflow of contrast material via nonmesenteric portal circulation through the gastric antrum, duodenum, and/or pancreas.

CONCLUSION

Intrahepatic portal veins are frequently opacified during CTHA, and the causes were arterioportal shunts through hepatocellular carcinoma, postbiopsy shunt, portal vein thrombosis, and inflow of contrast material via the nonmesenteric portal circulation.