Arteriovenous Malformation Associated with Intravenous Leiomyomatosis of the Uterus: Characteristic CT Findings and Treatment by Embolization and Surgery.

Seven consecutive female patients with pathologically confirmed arteriovenous malformation (AVM) with intravenous leiomyomatosis (IVL) of the uterus (age range, 32-61 years; mean age, 43 years) treated between 2005 and 2021 from a single institution were reviewed. Computed tomography (CT) findings of congenital pelvic AVM of 10 female patients were compared with those of AVM with IVL. Characteristic CT findings of AVM with IVL revealed a focal soft tissue mass inside a dilated venous structure of the AVM. Multiple sessions of transvenous coil embolization of the AVM with or without the injection of ethanol were performed. After complete (6/7, 86%) or partial (1/7, 14%) embolization of the AVM, complete surgical resection of the IVL and embolized AVM mass was performed in 4 patients. Patients with lung metastasis or residual embolized AVM masses are under follow-up with antiestrogen hormonal therapy.

Therapeutic outcomes of embolotherapy of extremity bone intraosseous arteriovenous malformation with ethanol, coils, and n-butyl cyanoacrylate.

OBJECTIVE: We evaluated the therapeutic outcomes of embolotherapy for bone arteriovenous malformations (AVMs) affecting the extremities using ethanol, coils, and n-butyl cyanoacrylate (NBCA). METHODS: We reviewed the data from 36 patients (18 males, 18 females; mean age 25 years; age range, 1-64 years) with bone AVMs affecting their extremities who had undergone embolotherapy using ethanol, coils, and NBCA from December 1996 to July 2019. Of the 36 patients, 19 had had pure bone AVMs and 17 mixed bone and soft tissue (MBS) AVMs. Embolotherapy was performed using direct puncture or a transvenous or an intra-arterial approach (range, 1-18 procedures; mean, 5 procedures). During the 178 embolotherapy procedures, ethanol was used in all 36 patients, except for 1. Coils were used in 14 patients, and NBCA and a lipiodol mixture in 9 patients. The therapeutic outcomes were evaluated by the clinical symptom response and the degree of devascularization on follow-up angiography or computed tomography. The major and minor complications were also evaluated. RESULTS: The clinical success (cure or markedly improvement) rate of embolotherapy for pure bone AVMs was significantly better than that for the MBS AVMs (88% vs 18%; P < .001). The complete devascularization rate of the bone AVM component of the MBS AVMs was 71%; however, the cure rate of the MBS AVMs was 0% owing to the remaining soft tissue AVMs. Of the 36 patients, 12 experienced complications, including 11 minor (2 skin bullae formation and 10 transient peripheral nerve injury) and 1 major (longstanding nerve palsy). CONCLUSIONS: Embolotherapy for bone AVMs affecting the extremities using ethanol, coils, and an NBCA mixture is effective and safe for the resolution or improvement of symptoms, especially in those with pure bone AVMs.

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.

Combined therapy with bronchial artery embolization and tranexamic acid for hemoptysis.

BACKGROUND: While most previous studies have viewed tranexamic acid as a bridging or temporary therapy, our preliminary study offers insights into the combined therapy of antifibrinolytic agent with endovascular treatment for hemoptysis. PURPOSE: To investigate the feasibility and safety of combined therapy, to analyze factors affecting the outcomes of combined therapy, and to compare the effectiveness of combined therapy between groups with different etiologies. MATERIAL AND METHODS: Between January 2011 and December 2014, 64 patients (33 men, mean age 64.6 years) underwent combined therapy for hemoptysis. The median follow-up time was 14.7 months (range 174-2435 days). Patients were divided into a tuberculosis group (GroupTB, n=37) and a non-tuberculosis group (Groupnon-TB, n=27). RESULTS: Embolotherapy was technically successful in 62/64 (96.9%) cases. The immediate clinical success rate was 96.8% (60/62). The short-term and long-term recurrence rates were 12.9% (n=8) and 19.4% (n=12), respectively. The one-, two-, and four-year recurrence-free survival rates were 61%, 49%, and 32%, respectively. There was no significant survival difference between the two groups. Suboptimal embolization was a significant risk factor for immediate clinical failure (odds ratio 29.624, P = 0.023). Optimal embolization (hazard ratio [HR] 0.199, P = 0.023) and older age (HR 0.956, P = 0.013) were significantly associated with lower recurrence risk. CONCLUSION: Combined therapy is an effective and safe treatment modality for hemoptysis of various etiologies, with potential benefits for short-term recurrence vis-a-vis current literature evidence. Suboptimal embolization was the most important modifiable risk factor for treatment failure and recurrence after combined therapy.

CT findings after left renal vein division during abdominal aortic surgery.

BACKGROUND: The rationale behind left renal vein division (LRVD) is the assumption that adequate collateral draining channels will develop. PURPOSE: To describe computed tomography (CT) findings after LRVD during aortic surgery. MATERIAL AND METHODS: Among 61 consecutive patients who underwent LRVD during aneurysm repair or revascularization for aortic occlusive disease between January 2003 and December 2017, 51 patients (40 men, mean age 71.4 ± 8.4 years) were enrolled. Contrast-enhanced CT images were analyzed to evaluate collateral drainage, patency, left renal vein diameter, and left renal parenchymal thickness. A total of 115 radiologic reports were reviewed to check whether these findings were accurately mentioned. RESULTS: The median time period of the first postoperative follow-up CT was 36 days (range 7-1351 days). The gonadal vein (n = 47) was the most common collateral draining channel, followed by the retroperitoneal veins (n = 42) and adrenal vein (n = 33). Thrombosis occurred in five patients between postoperative days 7 and 17 in the remnant renal vein (n = 3), remnant renal vein plus gonadal and adrenal veins (n = 1), and gonadal vein (n = 1). There was a significant decrease in renal vein diameter (-0.48 ± 2.12 mm, P = 0.006). There was no significant difference in parenchymal thickness (-0.25 ± 1.27 mm, P = 0.193). Neither LRVD nor any associated findings were correctly stated on radiologic reports. CONCLUSION: Postoperative contrast-enhanced CT can delineate collateral draining channels and complications following LRVD. However, these findings tend to be either missed or misinterpreted.

Endovascular treatment results and risk factors for complications of body and extremity arteriovenous malformations.

OBJECTIVE: The objective of this study was to investigate the factors associated with the complication rate and treatment outcomes of arteriovenous malformations (AVMs) during a 20-year period. METHODS: This was a retrospective study of 306 patients (135 men, 171 women; mean age, 30.8 years) with body and extremity AVMs who were treated between 1996 and 2017. A total of 913 sessions of endovascular treatment were performed. Patients were divided into two decades of the study period to compare complications and clinical results. Group 1 comprised 107 patients treated in the first decade of the study period, and group 2 comprised 199 patients treated in the last decade. AVMs were classified according to the angiographic findings. Complication rates, number of treatment sessions, and treatment results were compared between the two groups. RESULTS: Minor complication (group 1, 20.1%; group 2, 18.5%) and major complication (group 1, 3.1%; group 2, 4.1%) rates were similar between groups (P = .79). The mean number of treatment sessions in group 1 and group 2 was 4.2 and 2.3, respectively, indicating a 45% reduction in treatment sessions (P < .0001). The treatment failure rate decreased from 9.3% in group 1 to 1.5% in group 2 (P = .04). The clinical success rate was 54.2% in group 1 and 64.3% in group 2 (P = .10). CONCLUSIONS: With an accumulation of AVM treatment experience, the number of treatment sessions and the rate of treatment failures were significantly reduced.

Efficacy and Safety of Transvenous Embolization of Type II Renal Arteriovenous Malformations with Coils.

PURPOSE: To evaluate the efficacy and safety of transvenous coil embolization of the venous sac for type II renal arteriovenous malformation (AVM). MATERIALS AND METHODS: A retrospective review was conducted of 8 patients (5 women and 3 men; mean age, 57 years; age range, 41-69 years) who underwent transvenous coil embolization for type II congenital renal AVM at 5 different hospitals between 2012 and 2018. Additional intra-arterial ethanol injection was performed if shunt flow persisted after venous sac coiling. Technical success was defined as complete occlusion of shunt flow with coil embolization. Clinical success was defined as no symptom recurrence during the follow-up period. The renal parenchymal infarction rate was measured on computed tomography (CT), and procedure-related complications were reviewed. RESULTS: Nine sessions of embolization were performed for 8 patients. The mean venous sac size was 24 mm (range, 10-39 mm), and a mean of 14 micro and/or micro-detachable coils (range, 3-50) were used. The technical success rate was 88% (7 of 8) using coil embolization. One patient (12%) required additional ethanol injection to complete occlusion of the shunt flow and had a less than 10% parenchymal infarction on follow-up CT. No procedure-related complications or recurrences occurred during a mean clinical follow-up period of 20.8 months (range, 4.7-76.6 months). CONCLUSIONS: Transvenous coil embolization of type II renal AVM showed an 88% technical success rate. One patient (12%) showed less than 10% renal parenchymal infarction after additional ethanol injection. No additional complications or recurrences occurred during the follow-up period.

Effect of Hyperbilirubinemia on Hepatic Hypertrophy after Portal Vein Embolization and Liver Failure after Hepatectomy in Primary Biliary Malignancy.

PURPOSE: To retrospectively investigate the impact of hyperbilirubinemia on future liver remnant (FLR) volume after percutaneous transhepatic portal vein embolization (PVE) and incidence of post-hepatectomy liver failure in primary biliary malignancy. MATERIALS AND METHODS: Eighty-seven patients (62 men, overall mean age 66.9 y) who underwent PVE, using Gelfoam and coils before major hepatectomy between January 2004 and June 2016, were included in this study and divided into a hyperbilirubinemia (serum total bilirubin level at PVE 5.80 ± 2.44 mg/dL; n = 41) group and a control group (1.09 ± 0.73 mg/dL; n = 46). Liver volume was measured from computerized tomographic data before and 18.5 days, on average, after PVE. Correlation between FLR hypertrophy (degree of hypertrophy and percentage increase in future liver remnant [%FLR]) and total bilirubin were analyzed. FLR hypertrophy and incidence of post-hepatectomy liver failure were compared. Simple and multiple regressions were used for univariable and multivariable analyses, respectively. RESULTS: Mean FLR volumes before and after PVE were 529.1 cm3 and 640.5 cm3, respectively. Degree of hypertrophy and %FLR were 7.64 ± 4.22 and 21.77 ± 13.34, respectively. There was no significant correlation between FLR hypertrophy and total bilirubin (P > .5). FLR hypertrophy was not significantly different between the 2 groups. Planned major hepatectomy was performed in 73 patients (83.9%). Grade 3 post-hepatectomy liver failure occurred in 6 patients (8.2%; 2 in the hyperbilirubinemia group and 4 in the control group), and its incidence was not significantly different between the groups (P = .354). CONCLUSIONS: Hyperbilirubinemia at the time of PVE seems to have no effect on FLR hypertrophy. The incidence of grade 3 post-hepatectomy liver failure is not likely to be influenced, either.

Subclassification and Treatment Results of Ethanol Embolotherapy of Type II Arteriovenous Malformations of the Extremity and Body.

PURPOSE: To evaluate the safety and efficacy of ethanol and coil embolization of type II arteriovenous malformation (AVM) according to a new subtype classification. MATERIALS AND METHODS: Eighty-four type II AVMs in the body or extremity of 79 patients who underwent AVM treatment from 1996 to 2017 were retrospectively subclassified according to the angiographic morphology of the draining vein as type IIa (arterioles shunt to focal segment of single draining vein), type IIb (arterioles shunt to venous sac with multiple draining veins), and type IIc (arterioles shunt along long segment of draining vein). Coil and ethanol embolization of the focal or long segment of the draining vein or the venous sac was performed with direct puncture or transvenous approach according to subtype. Treatment outcomes, number of treatment sessions, and complications were analyzed. RESULTS: AVM cure (ie, complete embolization) rates were 95%, 76%, and 65% in types IIa, IIb, and IIc AVMs, respectively. The cure rate of type IIa AVMs was significantly better than that of type IIc AVMs (P = .015). Median numbers of treatment sessions were 1 in types IIa and IIb AVMs and 2.5 in type IIc AVMs, with a significant difference between type IIc and the other 2 types (P < .05). Minor complications occurred in 20% of patents and major complications occurred in 7%. CONCLUSIONS: The cure rate of type IIa AVMs was significantly better than that of type IIc AVMs, which also required significantly more treatment sessions than the other 2 types.

Combined transarterial chemoembolization and radiofrequency ablation for small treatment-naïve hepatocellular carcinoma infeasible for ultrasound-guided radiofrequency ablation: long-term outcomes.

Background Ultrasound (US)-guided radiofrequency ablation (RFA) for small hepatocellular carcinoma (HCC) is often infeasible due to unfavorable location and poor conspicuity. Those small HCCs can be treated with combined transarterial chemoembolization (TACE) and RFA. Purpose To evaluate long-term outcomes of combined TACE and RFA for small treatment-naïve HCC infeasible for US-guided RFA. Material and Methods Between February 2009 and January 2014, 69 patients with small (≤3 cm) HCC infeasible for US-guided RFA received TACE and subsequent RFA in one session as a first-line treatment. Local tumor progression (LTP), overall survival (OS), and event-free survival rates were evaluated. Univariate and multivariate analyses were conducted to identify prognostic factors. Results Cumulative rates of LTP were 4.4%, 6.8%, 8.2%, 9.5%, and 9.5% at one, two, three, five, and seven years, respectively. Cumulative one-, two-, three-, five-, and seven-year OS rates were 100%, 95%, 89%, 80%, and 80%, respectively. Cumulative one-, two-, three-, five-, and seven-year event-free survival rates were 81%, 63%, 54%, 31%, and 20%, respectively. No significant prognostic factors for LTP, OS, and event-free survival were identified in univariate analysis. Conclusion Combined TACE and RFA appears to be an effective treatment for small treatment-naïve HCC infeasible for US-guided RFA in terms of LTP and OS.

Treatment strategy based on the natural course for patients with spontaneous isolated superior mesenteric artery dissection.

OBJECTIVE: The optimal treatment of spontaneous isolated superior mesenteric artery dissection (SISMAD) is still not known, and we sought to determine an optimal treatment strategy for patients with SISMAD based on its natural clinical course. METHODS: We retrospectively reviewed consecutive patients with SISMAD treated from 2001 through 2016. Diagnosis and angiographic type of SISMAD were determined with contrast-enhanced computed tomography (CT) scan, and the clinical features were obtained using a fixed form questionnaire. All patients were treated conservatively, except for five who unselectively underwent primary interventional treatment. For the follow-up examinations, clinical features and morphologic changes of superior mesenteric artery dissection were examined with CT angiography every 6 to 12 months. RESULTS: During the past 15 years, 116 patients with SISMAD (male, 92%; mean age, 54.7 ± 10.8 years; symptomatic, 76%) were encountered. Clinical features and morphologic changes on CT examinations were available in 100% and 88% of the patients, respectively, during the mean follow-up of 53 ± 39 months (range, 1-173 months). Of 83 symptomatic patients managed conservatively, 96% achieved pain resolution; 4% experienced prolonged pain, including one patient with bowel gangrene. After pain resolution, 20% of patients developed late recurrence of abdominal pain, which was relieved with conservative management, whereas two patients (12%) required surgery to treat bowel stricture. Follow-up examinations (n = 102) by CT angiography revealed no change in 34%, partial or complete remodeling in 63%, aneurysmal change in 2%, and dissection progression in 1% of the patients. Antithrombotic therapy offered no beneficial effects on either clinical or morphologic outcomes. CONCLUSIONS: With conservative treatment, the majority of patients with SISMAD showed clinical improvement and no morphologic changes during long-term follow-up. We thus recommend a conservative management strategy as the first-line treatment for patients with SISMAD, regardless of angiographic type.

Factors Related to Late False Lumen Enlargement after Thoracic Stent-Graft Placement for Type B Aortic Dissection.

PURPOSE: To evaluate significant factors related to delayed aortic false lumen (FL) enlargement in patients who have undergone thoracic stent-graft placement for type B aortic dissection. MATERIALS AND METHODS: The study included 62 patients (45 male, 17 female) aged 26-80 years (mean age, 58.1 y) who underwent thoracic endovascular aortic repair for type B aortic dissection at a single institution between January 2005 and May 2015. Mean age of aortic dissections was 5.3 months (range, 0.1-73.3 mo). Maximum aortic diameter at presentation was 41.7 mm ± 8.3. The follow-up period ranged from 3 to 104 months (mean, 27.1 mo). Computed tomographic (CT) angiography studies were reviewed to identify FL diameter enlargements > 5 mm at different levels along and distal to the stent graft. Imaging findings and clinical variables were investigated to determine their correlation with FL enlargement. RESULTS: No significant difference was found between the ages of aortic dissections in patients with and without FL enlargement (P = .26). On follow-up CT angiography, 16 patients had 2 or more communication channels between the FL and the systemic circulation, 7 of whom showed FL enlargement > 5 mm (P = .007). Twenty-seven patients showed complete FL thrombosis, none of whom had FL enlargement (P < .001). CONCLUSIONS: Two or more communication channels between the FL and the systemic circulation represent a risk factor for FL enlargement regardless of the age of the dissection. Patients with thrombosis of the FL are less likely to experience FL enlargement.

Embolization of Congenital Renal Arteriovenous Malformations Using Ethanol and Coil Depending on Angiographic Types.

PURPOSE: To evaluate effectiveness and safety of embolization of congenital renal arteriovenous malformations (AVMs) using ethanol and/or coil according to angiographic type. MATERIALS AND METHODS: Between August 2010 and October 2015, 11 patients (13 sessions; 10 women and 1 man; mean age, 50.8 y) with congenital renal AVMs were treated using ethanol and/or coils via 2 approaches (transarterial access or direct puncture). Demographics, clinical findings, diagnostic modalities, angiographic types, technical and clinical success rates, and complications were reviewed. Renal AVMs were classified into 3 angiographic types, and treatment was based on this classification. RESULTS: Technical success rate was 91% (10/11), and clinical success rate was 100% (11/11). Of patients, 7 had type III AVMs, 3 had type I AVMs, and 1 had type II AVM. Embolic agents were ethanol in 5 patients, coils with ethanol in 3 patients, and coils in 3 patients. Of the 8 patients treated with ethanol, 6 had infarcted renal areas of 3.5%-30% (mean, 14.6%). After a mean follow-up period of 16.3 months, there was no evidence of recurrent AVMs on imaging or laboratory studies. CONCLUSIONS: Embolization of congenital renal AVMs via transarterial or direct percutaneous approaches using ethanol and/or coils based on a simple angiographic classification was safe and effective and elicited good outcomes. Most of the patients with congenital renal AVMs were women.

Clinical outcome and predictors of treatment response in foam sodium tetradecyl sulfate sclerotherapy of venous malformations.

OBJECTIVES: To evaluate clinical outcomes and their predictors in patients with venous malformation (VM) treated with foam sodium tetradecyl sulfate (STS) sclerotherapy. METHODS: We retrospectively evaluated clinical outcomes of foam STS sclerotherapy in 86 patients with 91 VMs to assess reduction in pain and mass after treatment. Univariate and multivariate analysis was performed to determine possible predictors of clinical outcome with foam STS sclerotherapy. RESULTS: A positive response of 49.5% in pain reduction and 52.7% in mass reduction was observed. The numerical rating scale (NRS) score improved from 4.36 ± 2.64 to 1.74 ± 1.57, and VM mass volume decreased to 41.7 ± 35.52% of the initial size. On multivariate analysis, a high baseline NRS score (odds ratio: 1.12, 95% confidence interval: 1.09-1.15) and VM location in the trunk versus the head and neck (odds ratio: 1.30, 95% confidence interval: 1.00-1.69) were positive predictors of pain improvement. Minor complications occurred in 11 (12.1%) patients and recurrence in 12 (13.2%) patients. CONCLUSIONS: Foam STS sclerotherapy is an effective treatment in venous malformation, with low complication risk. A high baseline NRS score and location in the trunk versus the head and neck were positive predictors in improvement of pain. KEY POINTS: • Foam STS sclerotherapy is effective in VM, with low risk of complications. • Relief of pain tends to be dramatic in patients with severe pain. • Location of VM is a predictor of pain improvement. • The presence of a draining vein does not affect foam sclerotherapy.

Feasibility and efficacy of primary tractography during percutaneous catheter drainage.

BACKGROUND: The indication of percutaneous catheter drainage (PCD) has expanded with the development of guiding modalities. Since serious complications still occur, efforts and new techniques have been continuously searched for safer PCD. PURPOSE: To evaluate the feasibility and efficacy of primary tractography for establishing a safe needle pathway during PCD. MATERIAL AND METHODS: A total of 42 patients (20 men, 22 women; mean age, 50.7 years) who underwent primary tractography during PCD were prospectively enrolled between April 2009 and August 2013. The locations of fluid collection included sub-phrenic (n = 8), between bowel loops (n = 21), pelvic cavity (n = 8), within solid organ (n = 2), and others (n = 3). The interposed anatomic structures were analyzed on the basis of primary tractography findings. Complications related to PCD or primary tractography were evaluated. RESULTS: Interposition of any significant anatomic structure was confirmed in 10 of 42 patients (23.8%). The entrapped anatomic structures were the omental vessel (n = 4), bowel (n = 2), pleura (n = 2), bile duct (n = 2), and a branch of the left inferior epigastric artery (n = 1). In one patient, both the pleura and bile duct were interposed simultaneously. The technical and clinical success rates of PCD were 97.6% and 97.6%, respectively. No complications related to PCD or primary tractography occurred during the follow-up period. CONCLUSION: Primary tractography is a simple and feasible method to evaluate the entrapment of normal anatomic structure during PCD. This method may aid in preventing possible serious PCD-related complications, such as bleeding and fistula.

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.

Factors affecting anatomical changes after endovascular abdominal aortic aneurysm repair.

BACKGROUND: The primary goal of endovascular aneurysm repair (EVAR) is to prevent death from aneurysm rupture. Regression of aortic sac size is believed to be a marker for success after EVAR. This study analyzes the changes in aneurysm sac size and the factors affecting sac regression after EVAR. PATIENTS AND METHODS: We retrospectively reviewed 121 patients with abdominal aortic aneurysm (AAA) who underwent elective treatment with EVAR at our institution from January 2005 to December 2011. In this study, 17 of the 121 patients were excluded due to loss during follow-up or for not having undergone a postoperative computed tomographic (CT) scan, and 3 patients were excluded due to an isolated iliac artery aneurysm. CT scans were scheduled at months 1, 6, and 12, and annually thereafter. Aneurysm size was defined by the minor axis on the largest axial cut of the aneurysm on a two-dimensional CT scan. Sac regression was defined as a reduction in the diameter of more than 5 mm. RESULTS: Sac regression was observed during follow-up in 39 of the 101 patients. There was 1 regression in 87 patients (1%) at 1 month, 18 in 62 patients at 6 months (29%), 26 regressions in 44 patients (59%) at 12 months, and 18 regressions in 34 patients (53%) at 24 months. After multivariate analysis, the absence of endoleaks was the only factor associated with sac regression (hazard ratio, 3.620; confidence interval, 1.692-7.747; p = 0.001). CONCLUSION: Sac regression over 5 mm is associated with current or previous endoleaks after EVAR. Continued surveillance is necessary in all patients after EVAR to prevent late complications.

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.

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.