Use of Yttrium-90 embolization for metastatic liver lesions has become part of current Interventional Radiology practice. A detailed understanding of the anatomic origin of the right gastric artery has become essential to perform safe embolization of this small vessel and prevent gastric complications. Our purpose is to evaluate the different types of right gastric artery (RGA) origin; it's relationship with different celiac trunk anatomic variations and the implications to clinical practice. We randomly selected and retrospective analyzed celiac and superior mesenteric artery arteriograms performed in 465 different patients between July 7, 200 and March 27, 2010, at our institution. Imaging evaluation was performed in standard radiology workstations by two interventional radiologists and data was created by consensus. The emphasis of this study was on the different origins of the RGA, how it correlates to other major celiac trunk anatomic variations and possible implications to clinical practice. The RGA was found in 410 patients. The remaining 55 patients were excluded from the sample. The most common sites of origin of the RGA were the proper hepatic artery (PHA) n=220 (53.65%), followed by the left hepatic artery (LHA) n=81 (19.75%), common hepatic artery (CHA) n=37 (9.02%), bifurcating with the gastro duodenal artery (GDA) n=30 (7.31%), arising from the GDA n=21 (5.12%), right hepatic artery (RHA) n=14 (3.41%), bifurcating with the LHA n=7 (1.70%). Replaced right or common hepatic arteries were found in 40 patients (9.75%). The incidence of other anatomic variants in the celiac trunk was much higher (35% vs. 10.73%) in patients with RGA originating from the RHA then from other sites. Patients with replaced hepatic arteries had a higher rate of RGA origin from the CHA (20% vs. 9.02%). The most common origin of the RGA is from the PHA, followed by the LHA. In patients with replaced hepatic arteries or other anatomic variations in the celiac trunk, other locations may raise in frequency.

In selected patients with chronic pancreatitis (CP), total pancreatectomy (TP) may be effective for the treatment of intractable pain. Further, the ensuing brittle or labile insulin-dependent diabetes mellitus has been shown to be ameliorated with intra-operative islet cell autotransplantation (I-IAT). In contrast to the I-IAT method, our modified approach is performed through a percutaneous transhepatic approach in the immediate postoperative period. We describe our experience at our institution using this modified approach. A prospectively collected database of patients with CP undergoing TP with percutaneous transhepatic portal vein IAT (PT-IAT) was reviewed. Percutaneous transhepatic portal vein catheterization was performed under fluoroscopic guidance using a Ring needle. After PT-IAT, the puncture tract was embolized with gelfoam. From March 2009 to March 2011, 53 patients (81% female, mean age 41 years) underwent TP with PT-IAT (302 minutes mean elapased time from tissue excision to PT-IAT). Mean number of islet cell equivalents (IE) transplanted was 346,782 (4,784 IE/kg). Mean portal pressures (in mm Hg) were: pre-infusion 8.5 (range 2-15) and post-infusion 16.3 (range 4-37). 58% of the patients had either a minor or major complication (of which 7.5% were associated with PT-IAT): death (n=1), hospital acquired pneumonia (n=11, the most common complication), hepatic artery pseudoaneurysm (n=2), and portal vein thrombosis (n=2), which occurred in patients with infusion portal pressures > 30 mmHg. Hospital mean length of stay was 13.2 days. Mean insulin units on post-operative day 1 and on 6 month follow-up were 32.7 and 16.8 units, respectively (51% reduction). At 6 months 30% of the patients were insulin free and 50% of the patients required <10 units of insulin. There was a statistically significant negative correlation between the number of IE/kg transplanted and the 6 month insulin dose (r= -0.6). Percutaneous transhepatic islet cell autotransplantation in the immediate postoperative period is feasible, safe and it potentially can cure or ameliorate the diabetes-related morbidity associated with TP.

Hepatopulmonary syndrome is a pulmonary vascular complication of cirrhosis in which intrapulmonary vasodilatation (IPV) results in hypoxemia. Endothelin-1 (ET-1), produced by proliferating cholangiocytes, has been identified as a mediator of IPV in an animal model of HPS, but the pathophysiology of IPV in humans has not been defined.

BACKGROUND In selected patients with chronic pancreatitis, extensive pancreatectomy can be effective for the treatment of intractable pain. The resultant morbid diabetes can be ameliorated with islet autotransplantation (IAT). Conventionally, islet infusion occurs intraoperatively after islet processing. A percutaneous transhepatic route in the immediate postoperative period is an alternative approach. METHODS A prospectively collected database of patients undergoing pancreatectomy with percutaneous IAT (P-IAT) was reviewed. Hospital billing data were obtained and median charges determined and compared with estimated charges for an intraoperative infusion method of IAT (I-IAT). RESULTS Thirty-six patients (28 women; median age 48 years) underwent pancreatectomy with P-IAT. Median operative time was 232 min (range: 98-395 min) and median estimated blood loss was 500 cc (range: 75-3000 cc). Median time from pancreatic resection to islet transplantation was 269 min (range: 145-361 min). A median of 208 248 IEq (2298 IEq/kg) were harvested. Median peak portal venous pressure during islet infusion was 13 mmHg (range: 5-37 mmHg). Postoperative complications occurred in 15 patients (42%) and included hepatic artery pseudoaneurysm and portal vein thrombosis; the latter occurred in two patients with portal pressures during infusion > 30 mmHg. At a median follow-up of 10.7 months, eight patients (22%) were insulin-free. Median pertinent charges for P-IAT were US$36,318 and estimated median charges for I-IAT were US$56,440. Surgeon time freed by P-IAT facilitated an additional 66 procedures, charges for which amounted to US$463,375. CONCLUSIONS Percutaneous transhepatic IAT is feasible and safe. Islet infusion in the immediate postoperative period is cost-effective. Further follow-up is needed to assess longterm results.

Present a new coil characteristics and post embolization angiographic and pathologic findings in animal model. Nine swines were used for embolization of the left superior gluteal, hepatic and renal arteries with 3 and 5-Fr catheters. Different animals had immediate, 30 and 60 days angiographic and pathological evaluations. Hydrogel characteristics: free delivery (pushable/injectable), sizes of 0.018 and 0.035”, 2, 5 and 10 cm in length and 3- 8 mm in diameter. The hydrophilic polymers filaments are three-dimensional networks that swell in the presence of fluids and shrinks in the absence of it. The liquid component within the polymer allows for the free diffusion of oxygen, nutrients, and other molecules, whereas the polymer network provides a structural framework, making hydrogels biocompatible. It has water content of 70% (?) and swell up to 10 (?) times in weight. The poly (ether) makes up the bulk of the network while acrylic acid is used to impart expansion and control in the rate of expansion. Barium sulfate is added to opacify the hydrogel filaments. At 30 and 60 days follow-ups, angiographies showed persistent occlusion of the all embolized vessels and remarkable renal artery collateral circulation. Histology showed atrophic kidney, minimal hepatic and muscular tissue changes, complete thrombosis of the embolized vessels and minimal inflammatory response. One swine died due to renal dysfunction, no other clinical complications were observed. All the embolizations with the new coil were safe and effective in short and long term, with minimal inflammatory response.

Purpose: To define predictive factors for endoleak type II (EL-II) based on quantifiable factors in the imaging studies of patients undergoing endovascular aneurysm repair (EVAR).Methods: The data on 208 consecutive patients (137 men; mean age 75.2 years, range 62-84) who underwent EVAR between the years 2003 and 2008 were retrospectively reviewed. The abdominal aortic aneurysm (AAA) diameter ranged from 4.8 to 12.8 cm. Data were collected on the type of AAA; the type of stent-graft (aortomonoiliac versus bifurcated); the performance of hypogastric artery embolization; the presence, number, diameter, and patency of aortoiliac branches identified on the pre and post-EVAR imaging studies; and the presence and type of EL-II (transient vs. persistent) with the goal of identifying any imaging-based predictive factors for the development of EL-II.Results: Among the 208 cases, 11 patients had endoleaks other than type II and were excluded, leaving 195 patients for analysis. In all, 28 (13.4%) patients were diagnosed with EL-II. All had >= 4 patent lumbar arteries (mean diameter >2.3 mm). Ten patients with a transient EL-II had a mean of 4.3 patent lumbar arteries, which had diameters <2 mm (mean 1.5 mm). In the 18 patients with persistent EL-II, the mean diameter of the 4 lumbar arteries was 2.7 mm; at least 1 of the lumbar arteries was >2 mm. The presence of at least 4 patent lumbar arteries (p<0.001) and at least 1 patent hypogastric artery (p<0.001) were predictive factors for EL-II. At least 1 lumbar artery >2 mm in diameter was a positive predictive factor for the development of persistent EL-II (p<0.001).Conclusion: Patent hypogastric and lumbar arteries are significantly associated with a higher risk of developing EL-II. Larger diameter lumbar arteries tend to be associated with persistent EL-IIs, while lumbar arteries <2 mm would more likely be seen with a transient EL-II. If substantiated in larger studies, these angiographic criteria may guide early treatment of EL-II to avoid aneurysm sac expansion and potential rupture. J Endovasc Ther. 2011; 18: 299-305

Occurrence of a Type 2 endoleak (EL-2) is not uncommon and the etiology is not very well understood. The knowledge of predictive factors for EL-2 may help in clinical patient management. Our objective was to define some predictive factors for EL-2, based in the pre-treatment anatomic features of the AAA. Two hundred and eight patients underwent endovascular AAA repair and included in the study. Aortograms and CT scans were analyzed in retrospect to identify, characterize, compare and classify the EL-2 in two groups, transient and persistent. The transient EL-2, were the ones detected intra- or peri-operatively which spontaneously resolved within 6 months. The persistent EL-2 did not resolve spontaneously and lasted longer than 6 months. In 208 patients there were twenty-eight (13.5%) diagnosed EL-2. None of the patients with an EL-2 had less than four patent lumbar arteries at the time of EVAR (mean 5.2 vessels), with mean diameter of 2.3 mm. 45% of the patients underwent embolization of one of the internal iliac arteries. The mean number of feeding-vessels related to EL-2 was 4.3. The percentage of the thrombus occupation in the sac was 28%, and the IMA patency was 42%. There was no significant relationship between the amount of thrombus in the sac or IMA patency with the development of EL-2. Ten patients (35.7%) had transient EL-2 that resolved within one month. None of these cases had lumbar arteries larger than 2mm in diameter (mean 1.5mm). Eighteen (64.3%) of the 28 patients had persistent EL-2, the mean time to detection was 6,5 months, and he lumbar arteries had a mean diameter of 2.7mm. Persistent EL-2 developed in all cases with 4 patent lumbar arteries with at least one of them with 2 mm in diameter. None of the EL-2 shown in control angiograms without at least one lumbar artery greater than 2mm became persistent. The number of patent lumbar arteries (four or more p<0.001), and the hypogastric patency are importants predictive factors to the development of EL-2. The mean size of the lumbar arteries (>2mm) is a positive predictive factor to persistent EL-2 development (p<0.001).

Purpose To compare an injectable hydrogel embolic device with a pushable AZUR device procedurally, angiographically, and histologically in the embolization of porcine arteries. Materials and Methods In 12 pigs, embolization of renal, gluteal, and hepatic or thoracic arteries was performed with either injectable hydrogel embolic devices (two arteries per pig) or an AZUR device (one artery per pig). Follow-up angiography was performed before sacrifice in five pigs at 7 days after embolization and seven pigs at 90 days after embolization. The harvested tissues were evaluated histologically. Continuous and ordinal results were compared using analysis of variance and χ2 tests. Results For the sites with embolization performed with injectable hydrogel, complete angiographic occlusion was obtained in 21 of 24 (88%) sites after treatment, 10 of 10 (100%) sites at 7 days, and 10 of 14 (72%) sites at 90 days. For the sites with embolization performed with AZUR devices, complete angiographic occlusion was obtained in 10 of 12 (83%) sites after treatment, 4 of 5 (80%) sites at 7 days, and 5 of 7 (72%) sites at 90 days. Statistically significant differences in angiographic occlusion were not observed at 7 days (P = .13) or 90 days (P = .35). The embolization time of the injectable hydrogel group (14 minutes ± 8) was significantly reduced (P = .02) compared with the AZUR group (22 minutes ± 12). Differences between the groups in arterial wall damage were not evident at either 7 days or 90 days, although greater damage was observed in both groups at 90 days. In both groups, inflammation was nonexistent to minimal at 7 days and minimal to mild at 90 days. Conclusions Embolization of porcine arteries was as effective with injectable hydrogel embolic devices as pushable AZUR devices, as evidenced by the procedural, angiographic, and histologic results.

Animal models are useful for testing and development of devices and drugs, including efficacy, safety and creation of disease models. Our objective is to present the criteria for animal selection including the anatomic similarities to humans, vascular system size, coagulation parameters and reproduction of diseases and problems affecting humans. Twenty-one animal studies were retrospectively reviewed looking into the type of study, type of animal used, utilization of temporary or permanent device, drug or cell therapy and simulation of human diseases. The animals used were swine, canine and rodents. Devices tested included stents in the peripheral circulation and carotids, covered stents in the peripheral circulation and abdominal and thoracic aortic aneurysm model, angioplasty balloons, thrombectomy devices, IVC filters, venous valves, embolic materials, including particles, spheres and several types of coils. Drugs for angiogenesis and coagulation were also tested. Liver and kidney ablation with a variety of devices were performed. Human disease simulation included creation of renal artery stenosis, IVC stenosis, ureteral and biliary duct stenosis. Large animals such as swine were adequate for testing human size devices, such as stents, balloons, IVC filters, thrombectomy and venous valves, however, exuberant fibrin formation and intimal hyperplasia posed problems for permanent implants. Embolic materials can be tested in any size animal simulation of human diseases are best tested in larger animals. Drug therapy and angiogenesis can use medium size animals or large size animals. Simulation of AAA and pseudoaneurysms is better executed in medium to large size animals. The capacity of fibrin development and intrinsic fibrinolytic mechanisms are variable among animals used for research and the animal model needs to match the device to be tested. Several examples will be presented. Animal models are useful for training and for the testing and development of interventional radiology devices and drugs. Selection of the animal size, coagulation profile of the animal and anatomy target of the device or drug study is important for the success of the experiment.

Locoregional therapies for hepatocellular carcinoma have progressed greatly in the last 30 years, beginning with the introduction of chemoembolization . Embolization techniques have evolved with the use of drug-eluting beads and radioembolization with yttrium-90. In the last 10 years, several new ablation techniques were developed including radiofrequency ablation , microwave ablation , cryoablation, laser ablation, and irreversible electroporation . Isolated or in combination, these techniques have already shown that they can improve patient survival and/or provide acceptable palliation .

PURPOSE To address hypotheses concerning a decline in presentations pertaining to vascular interventions by interventional radiologists and the loss of ground in other areas, such as oncology, of presentations in vascular interventions at the Society of Interventional Radiology (SIR) Annual Scientific MeetingMATERIALS AND METHODS All abstracts for scientific presentations and scientific exhibits from the program book of the SIR annual meeting were reviewed from the period 1996-2006 The abstracts were grouped in different classes, such as (a) type of methodology, (b) reports on arterial interventions, (c) reports on oncologic interventions, and (d) geographic originRESULTS Scientific abstracts presented at the SIR annual meeting totaled 3,162 Presentations ranged from 177-407 (1996-2003) plus 250 in 2006 with a mean of 288 presentations per year The overall number of abstracts reporting arterial interventions had a peak of 89 presentations in 2000 and declined to 34 presentations in 2006 Reports of arterial interventions from the United States had a peak of 48 presentations in 2003 and declined to 12 in 2006 Reports of arterial interventions from Europe had a peak of 37 presentations in 2000 and declined to 11 in 2006 Reports of arterial interventions from Asia had a peak of 10 presentations in 1999 and declined to 6 in 2006 The trends are similar for the three components of arterial interventions when analyzed individually In 1997, 26 6% of all the presentations were arterial interventions, in 2000, 25 1%, and in 2006, only 13 6% There was a trend in the increase of oncology presentations starting in 2004 In 2003, it was 10%, and it was 22 4% in 2006CONCLUSIONS There has been a decline in the overall number of abstracts presented at the SIR annual meeting after a peak in 2003 There has been a decline in the number of arterial intervention reports The decline in presentations of arterial interventions that originated in the United States was also observed in presentations that originated from Europe and Asia There has been an increasing trend in interventional oncology reports starting in 2004

Selected patients with chronic pancreatitis may benefit from pancreatic resection. Postoperative diabetes can be ameliorated by autotransplantation of pancreatic islet cells (PIC's) harvested from the resected pancreas. Portal or mensenteric vein autotransplantation is typically performed intraoperatively and the percutaneous approach has not been used. The technique and results of our initial experience are presented. From March to September 2009, 18 patients (9 females), mean age of 39 years, with complicated chronic pancreatitis underwent pancreatectomy (17 total; 1 distal) followed by percutaneous transhepatic portal vein catheterization, under fluoroscopic guidance, using a Ring needle. After PIC's infusion, the puncture tract was embolized with gelfoam. The data was collected prospectively and from the online chart system. Isolated PIC's were transplanted early after pancreatectomy (mean 208 min., range 180-240). Average islet equivalents transplanted were 406,954 (5350 IEQ/kg), infused by gravity over a mean of 48.3 min. (range 15-65). Mean portal pressures in mmHg were: pre-infusion 9.6 (range 4-16), mid infusion 13.5 (range 7-24), peak 16.13 (12-20.85), post-infusion 15.6 (7-31). There were no deaths or early transplant related complications. One patient had a portal vein pericatheter thrombus treated with systemic heparinization. One patient had thrombocytopenia and coagulopathy. Two patients had transoperative hepatic hemorrhage, one with associated cardiac arrest successfully resuscitated. One patient had an intrahepatic arterial pseudoaneurysm due to transplant that was treated by coil embolization. Hospital length of stay was 12.4 days (range 6-21). Average of insulin administration: PO day 1 = 34.35 units (1.8-81.4), discharge day = 18.9 units (1-46) (∼45% reduction). Insulin independence was achieved in 33% of the patients at 2 months follow up (range 0.5-4). Percutaneous portal vein infusion of PIC's after pancreatectomy is safe, feasible with acceptable morbidity, and it potentially can cure or ameliorate PO diabetes. Further experience is needed to assess longer term outcomes. Risks and complications specific to islet infusion are minimal.

PurposeEmbolic events are common during carotid artery stenting (CAS). Embolic protection devices are used to prevent emboli from reaching the brain and cause infarction. Transcranial Doppler (TCD) is the only non-invasive technique available to detect and quantify the occurrence of microembolism in the cerebral arteries during the procedure.Materials and MethodsBilateral temporal TCD insonating the M1 segment of the middle cerebral artery (MCA) was performed in patients undergoing carotid artery stenting. 7 patients were protected using approved filters and 7 using reversal of flow with the Gore Flow Reversal System (GFRS). Doppler spectral and M-mode signals from ultrasound probes were continuously recorded. Detecting of high intensity transient signals (HITS) allowed for real-time feedback on the efficacy of the embolic protection, and flow dynamics. The recorded data were digitally stored for post-procedural comparison between the protection techniques and phases of the procedures. Quantification of microembolic signals (MES) for statistical analysis was performed by manual review for differentiation from injection and other artifacts.ResultsTCD signals were evaluated in three stages of the procedure: protection device deployment (PD), stent delivery including pre- and post dilatation (SD), and protection device removal (PR). MES were counted when detected and are presented as Filter vs. GFRS treatment group means ± SEM. Patients undergoing CAS under cerebral protection with GFRS demonstrated significantly less average total MES counts compared to procedures using filters: 431.3±65.4 vs. 116.3±20.8, N=14, p<0.001. While the PD and PR phases were not significantly different (PD 102.3±28.4 vs. 73.7.0±19.6, ns, and PR 34.3.4±24.4 vs. 36.7±8.9, ns), the SD phase, with the respective protection device in place, the average MES counts were significantly higher in patients treated with filter protection: 294.7±56.2 vs. 6.0±1.03, p<0.001.ConclusionPreliminary analysis of the study data suggests that patients undergoing CAS under reversal of flow with the GFRS device have significantly less MES than patients protected with filter devices. PurposeEmbolic events are common during carotid artery stenting (CAS). Embolic protection devices are used to prevent emboli from reaching the brain and cause infarction. Transcranial Doppler (TCD) is the only non-invasive technique available to detect and quantify the occurrence of microembolism in the cerebral arteries during the procedure. Embolic events are common during carotid artery stenting (CAS). Embolic protection devices are used to prevent emboli from reaching the brain and cause infarction. Transcranial Doppler (TCD) is the only non-invasive technique available to detect and quantify the occurrence of microembolism in the cerebral arteries during the procedure. Materials and MethodsBilateral temporal TCD insonating the M1 segment of the middle cerebral artery (MCA) was performed in patients undergoing carotid artery stenting. 7 patients were protected using approved filters and 7 using reversal of flow with the Gore Flow Reversal System (GFRS). Doppler spectral and M-mode signals from ultrasound probes were continuously recorded. Detecting of high intensity transient signals (HITS) allowed for real-time feedback on the efficacy of the embolic protection, and flow dynamics. The recorded data were digitally stored for post-procedural comparison between the protection techniques and phases of the procedures. Quantification of microembolic signals (MES) for statistical analysis was performed by manual review for differentiation from injection and other artifacts. Bilateral temporal TCD insonating the M1 segment of the middle cerebral artery (MCA) was performed in patients undergoing carotid artery stenting. 7 patients were protected using approved filters and 7 using reversal of flow with the Gore Flow Reversal System (GFRS). Doppler spectral and M-mode signals from ultrasound probes were continuously recorded. Detecting of high intensity transient signals (HITS) allowed for real-time feedback on the efficacy of the embolic protection, and flow dynamics. The recorded data were digitally stored for post-procedural comparison between the protection techniques and phases of the procedures. Quantification of microembolic signals (MES) for statistical analysis was performed by manual review for differentiation from injection and other artifacts. ResultsTCD signals were evaluated in three stages of the procedure: protection device deployment (PD), stent delivery including pre- and post dilatation (SD), and protection device removal (PR). MES were counted when detected and are presented as Filter vs. GFRS treatment group means ± SEM. Patients undergoing CAS under cerebral protection with GFRS demonstrated significantly less average total MES counts compared to procedures using filters: 431.3±65.4 vs. 116.3±20.8, N=14, p<0.001. While the PD and PR phases were not significantly different (PD 102.3±28.4 vs. 73.7.0±19.6, ns, and PR 34.3.4±24.4 vs. 36.7±8.9, ns), the SD phase, with the respective protection device in place, the average MES counts were significantly higher in patients treated with filter protection: 294.7±56.2 vs. 6.0±1.03, p<0.001. TCD signals were evaluated in three stages of the procedure: protection device deployment (PD), stent delivery including pre- and post dilatation (SD), and protection device removal (PR). MES were counted when detected and are presented as Filter vs. GFRS treatment group means ± SEM. Patients undergoing CAS under cerebral protection with GFRS demonstrated significantly less average total MES counts compared to procedures using filters: 431.3±65.4 vs. 116.3±20.8, N=14, p<0.001. While the PD and PR phases were not significantly different (PD 102.3±28.4 vs. 73.7.0±19.6, ns, and PR 34.3.4±24.4 vs. 36.7±8.9, ns), the SD phase, with the respective protection device in place, the average MES counts were significantly higher in patients treated with filter protection: 294.7±56.2 vs. 6.0±1.03, p<0.001. ConclusionPreliminary analysis of the study data suggests that patients undergoing CAS under reversal of flow with the GFRS device have significantly less MES than patients protected with filter devices. Preliminary analysis of the study data suggests that patients undergoing CAS under reversal of flow with the GFRS device have significantly less MES than patients protected with filter devices.

Over the past several years, there has been continued significant interest in refinement of patient selection, devices, procedures and protocols in an effort to optimize the outcome of percutaneous intervention for carotid bifurcation stenosis, including: ongoing National Institutes of Health and manufacturer trials and registries; the further refinement of existing devices and emergence of new platforms to attain distal embolic protection; ongoing study of what really constitutes a high-risk carotid surgery or stenting patient; and attention to device characteristics and patient-device matching. Within the latter area, considerable interest has focused on stent characteristics that have the potential to impact short and long-term outcome when compared with other stent design strategies when studied in large series. The stent in carotid artery intervention occupies a unique role in that after the embolic protection system has been removed, it is the main line of defense (in concert with aggressive dual antiplatelet therapy) from embolic and thromboembolic complications that may arise from the newly remodeled plaque after post-stent angioplasty. In this review, we aim to update the current status of efforts to relate stent design strategy to outcome in intervention for extracranial carotid artery disease with a focus primarily on the function of "free cell area" (typically lower with closed-cell stents and higher with open-cell stents) in analyses of outcome in carotid artery stenting. Also, the potential role of closed-cell vs. open-cell stent selection in other reports related to carotid artery stenting outcome or complications is reviewed. Rigorous studies have examined the issue of free cell area and arrived at disparate conclusions. Randomized data on the impact of free cell area and cell design strategy on carotid intervention are presently lacking. However, we believe sufficient data and rationale exist 1) to warrant ongoing study of the impact of stent design on outcome in carotid intervention; and 2) to make consideration of closed-cell (low free cell area) stent use a reasonable approach to device selection--when patient factors, lesion characteristics, or device availability make doing so possible.

A radiofrequency (RF) wire puncture technique was used in the recanalization of biliary anastomotic occlusions in five patients. The technical success of recanalization, which was defined as successful puncture and crossing of the obstruction followed by balloon cholangioplasty and internal-external biliary drainage without evidence of complications, was 100%. The average follow-up was 13 months (range, 11-16 months). For biliary occlusion recanalization, the RF wire may allow the use of percutaneous therapy in the treatment of a subset of individuals who would otherwise have to undergo open surgical intervention.

Describe the use of radiofrequency (RF) wire puncture technique for the recanalization of chronic central venous obstructions in symptomatic patients with previous failed attempts using conventional endovascular techniques. Details of the technique and the results of our initial experience are presented. Between June/08 and September/09, 6 patients (4 males/2 female), age ranging from 52 to 72 years, all presenting with swollen arm secondary benign central venous occlusions (one subclavian, 4 brachiocephalic veins, one superior vena cava) related to previous catheter placements for hemodialysis access. Simultaneous upper extremity (brachial approach) and central venograms (femoral approach) defined the central occlusion site. The PowerWireTM (Baylis Medical Company, Montreal, QC, Canada) RF wire was advanced within a 5-Fr KMP catheter. A straight wire tip combined with a semi-curved catheter provides higher precision during the tissue puncture. Once in contact with the occlusion site, the RF energy was delivered while the wire was gently advanced for a few millimeters at a time towards a target catheter placed in the opposite venous side. Once RF wire access was obtained to the contra-lateral side of the obstruction, a loop snare was used to assist the catheterization. The KMP catheter was advanced and the RF wire was exchanged for a stiffer wire and six/eight millimeters balloon angioplasties were followed by stent or stent-graft placement. If the puncture was inadequate, a new location was pursued. Four patients were successfully treated with RF wire after previous failed attempts at recanalization using mechanical catheter/wire techniques. In two patients the procedure was aborted, in one due to hemothorax successfully treated with chest tube without clinical repercussions. All the successfully treated patients had resolution of symptoms in a 4(2-8)months mean follow up. RF wire offers a promising alternative in the recanalization of benign chronic central venous occlusions when conventional techniques failed.