216% on day 30 in group B). These diameters subsequently stabilized. Pathology showed lack of elastin and increased collagen in both groups, features normally found in human AAA specimens. CONCLUSION: Both models can be useful in the short term development, training and evaluation of new endoprostheses. The peritoneum model is technically easier to create, and it exhibits a higher rate of postoperative dilatation, so it could be more useful than the serosa model. Scientific Session 13 Arterial Recanalization Saturday, March 27, 2004 8:00 AM - 9:30 AM Moderator(s): Goelz M Richter, MD, PhD Shaun L. Samuels, MD 8:00AM Abstract No. 66 Cross Sectional Conformation of Self-Expanding Stents Deployed Using a "Kissing" Technique. MA. Hughes, University of Michigan Medical Cenlel; Ann Arbor, A;[] , USA'A.R. Forauer'M Lindh PURPOSE: Self-expanding stents are often used to treat atherosclerotic stenoses at the aortic bifurcation. This study examines the proximal cross sectional conformation of three different stents when they are deployed using "kissing" technique in vitro. MATERIALS AND METHODS: One stainless steel stent design and two Nitinol stent designs were evaluated. 10mm diameter stents were used . The stents were deployed simultaneously in identical rigid plastic tubes. The stents were placed in a 37°C water bath to simulate body temperature and facilitate an accurate conformation of the nitinol stents. Each stent pair was deployed three times. Four axial computed tomography linages were obtained to evaluate the conformation of the proximal stents. The images were evaluated on a GE Windows Workstation to determine the areas included within and excluded by the stent pairs. Actual measurements of the excluded area were calculated by tracing the excluded area free hand using a cursor based method and commercially available software. RESULTS: The excluded areas were drawn five times for each deployment pair and the mean value of the excluded area with standard deviation for each stent group was calculated. An analysis of variance between the. three stent groups was performed and demonstrated a statistically significant difference (p<O.OOI) between the mean excluded areas. Post hoc statistical testing demonstrated a significant difference between the stainless steel design and both Nitinol designs (p<0.001). The excluded area with the stainless steel stent pair is significantly larger than that observed with the Nitinol designs. No statistical significance was noted when the Nitinol designs were directly compared to each other. CONCLUSION: When the areas excluded by adjacent stents in an in vitro model are compared, there is a statistically significant difference (p<0.00 I) between the stainless steel stent design and the two Nitinol stent designs. The Nitinol stents have smaller excluded areas when compared to the stainless steel stent. By limiting the excluded area / maximizing the cross-sectional conformation of the kissing stents one can theoretically maximize the laminar flow through a vessel. 8:11 AM Abstract No. 67 Endovascular Treatment of Celiac and Mesenteric Arteries Stenoses: Applications and Results. MJ. Sharafuddin, University of Iowa Carver College of Medic ine, Iowa City, lA, USA· S. Sun ·CH. Olson ·J.D. Corson·J. Golzarian PURPOSE: To evaluate the safety and assess the role of endovascular therapy in a variety of conditions related to celiac and mesenteric vascular occlusive disease. MATERIALS AND METHODS: Our retrospective study population included 25 consecutive patients (mean age 66 years), in whom 28 procedures were performed on 26 stenosed or occluded mesenteric vessels (superior mesenteric artery- SMA or celiac artery-CA). Indications included chronic mesenteric ischemia (21 patients), including two patients who underwent stenting prior to a planned operative repair of a juxta-mesenteric AAA. Three liver transplantation patients underwent stenting of an associated CA stenosis. One patient with a splenorenal bypass underwent stenting on an associated CA stenosis. The technical and clinical success rates and the incidence of complications were determined. Follow-up parameters included maintained patency on duplex sonography and sustained clinical benefit. The need for additional interventions was noted. RESULTS: All but one procedure were technically successful (96%). Major complications occurred in 3 patients (I transient contrast-induced nephrotoxicity, 2 pseudoaneurysms). Immediate clinical success was achieved in 22 patients (88%). The three clinical failures included two patients with an excellent angiographic outcome, but single-vessel moderate severity disease. Survival table analysis of delayed clinical outcome showed primary and pr'imary-assisted clinical benefits at II months of 85% and 91 %, respectively. Primary and primary-assisted stent patencies, as assessed by duplex sonography and/or angiography, at 6 months were both 92%. Angiographically documented restenosis occurred in three patients. Restenosis in two patients with CA stents was due to extrinsic compression, and was asymptomatic in one patient, and was treated satisfactorily by res tenting in the other patient. Restenosis in one patient with an SMA stent was successfully treated by restenting. CONCLUSION: Our experience suggests a potential role for endovascular therapy of celiac and mesenteric arterial occlusive disease in a variety of clinical scenarios, with a low incidence of complications and a high technical success rate. 8:22AM Abstract No. 68 Excimer Laser-Assisted AngiopJasty in Severe Infrapopliteal Disease: A "LACI Equivalent" Update. D. E. Allie, Cardiovascular Institute of the South, Lafayette, LA, USA ·CJ. Hebert·MH. Khan-A.A. Allie·MA. Khan 'CM Walker, et al. PURPOSE: 12 month major amputation rates in "true limb salvage" (Rutherford class 5-6 with established tissue loss) are reported as > 90% if nonrevascularable and 25% if revascularable. 24 month mortality rates of > 40-50% are reported post amputation and < 50% will ambulate with a prosthesis. The encouraging Laser Angioplasty for ,Critical Limb Ischemia (LAC!) 6 month limb salvage (LS) rate of93% prompted adoption of excimer laser assisted angioplasty as our primary infrapopliteal treatment for "TLS". AfATERIALS AND METHODS: Between October 2001- August 2003, 62 patients (62 limbs) with Rutherford class 5- 6 symptoms presented with severe infrapopliteal disease S167
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216% on day 30 in group B). These diameters subsequently stabilized. Pathology showed lack of elastin and increased collagen in both groups, features normally found in human AAA specimens.
CONCLUSION: Both models can be useful in the short term development, training and evaluation of new endoprostheses. The peritoneum model is technically easier to create, and it exhibits a higher rate of postoperative dilatation, so it could be more useful than the serosa model.
Scientific Session 13 Arterial Recanalization
Saturday, March 27, 2004 8:00 AM - 9:30 AM Moderator(s): Goelz M Richter, MD, PhD
Shaun L. Samuels, MD
8:00AM Abstract No. 66
Cross Sectional Conformation of Self-Expanding Stents Deployed Using a "Kissing" Technique. MA. Hughes, University of Michigan Medical Cenlel; Ann Arbor, A;[], USA'A.R. Forauer'M Lindh
PURPOSE: Self-expanding stents are often used to treat atherosclerotic stenoses at the aortic bifurcation. This study examines the proximal cross sectional conformation of three different stents when they are deployed using "kissing" technique in vitro.
MATERIALS AND METHODS: One stainless steel stent design and two Nitinol stent designs were evaluated . 10mm diameter stents were used . The stents were deployed simultaneously in identical rigid plastic tubes. The stents were placed in a 37°C water bath to simulate body temperature and facilitate an accurate conformation of the nitinol stents. Each stent pair was deployed three times . Four axial computed tomography linages were obtained to evaluate the conformation of the proximal stents. The images were evaluated on a GE Windows Workstation to determine the areas included within and excluded by the stent pairs. Actual measurements of the excluded area were calculated by tracing the excluded area free hand using a cursor based method and commercially available software.
RESULTS: The excluded areas were drawn five times for each deployment pair and the mean value of the excluded area with standard deviation for each stent group was calculated. An analysis of variance between the . three stent groups was performed and demonstrated a statistically significant difference (p<O.OOI) between the mean excluded areas. Post hoc statistical testing demonstrated a significant difference between the stainless steel design and both Nitinol designs (p<0.001). The excluded area with the stainless steel stent pair is significantly larger than that observed with the Nitinol designs. No statistical significance was noted when the Nitinol designs were directly compared to each other.
CONCLUSION: When the areas excluded by adjacent stents in an in vitro model are compared, there is a statistically significant difference (p<0.00 I) between the stainless steel stent design and the two Nitinol stent designs. The Nitinol stents have smaller excluded areas when compared to the stainless steel stent. By limiting the excluded area / maximizing the cross-sectional conformation of the kissing stents one can theoretically maximize the laminar flow through a vessel.
8:11 AM Abstract No. 67
Endovascular Treatment of Celiac and Mesenteric Arteries Stenoses: Applications and Results. MJ. Sharafuddin, University of Iowa Carver College of Medicine, Iowa City, lA, USA·S. Sun ·CH. Olson ·J.D. Corson·J. Golzarian
PURPOSE: To evaluate the safety and assess the role of endovascular therapy in a variety of conditions related to celiac and mesenteric vascular occlusive disease.
MATERIALS AND METHODS: Our retrospective study population included 25 consecutive patients (mean age 66 years), in whom 28 procedures were performed on 26 stenosed or occluded mesenteric vessels (superior mesenteric arterySMA or celiac artery-CA). Indications included chronic mesenteric ischemia (21 patients), including two patients who underwent stenting prior to a planned operative repair of a juxta-mesenteric AAA. Three liver transplantation patients underwent stenting of an associated CA stenosis. One patient with a splenorenal bypass underwent stenting on an associated CA stenosis. The technical and clinical success rates and the incidence of complications were determined. Follow-up parameters included maintained patency on duplex sonography and sustained clinical benefit. The need for additional interventions was noted.
RESULTS: All but one procedure were technically successful (96%). Major complications occurred in 3 patients (I transient contrast-induced nephrotoxicity, 2 pseudoaneurysms). Immediate clinical success was achieved in 22 patients (88%). The three clinical failures included two patients with an excellent angiographic outcome, but single-vessel moderate severity disease. Survival table analysis of delayed clinical outcome showed primary and pr'imary-assisted clinical benefits at II months of 85% and 91 %, respectively. Primary and primary-assisted stent patencies, as assessed by duplex sonography and/or angiography, at 6 months were both 92%. Angiographically documented restenosis occurred in three patients. Restenosis in two patients with CA stents was due to extrinsic compression, and was asymptomatic in one patient, and was treated satisfactorily by res tenting in the other patient. Restenosis in one patient with an SMA stent was successfully treated by restenting.
CONCLUSION: Our experience suggests a potential role for endovascular therapy of celiac and mesenteric arterial occlusive disease in a variety of clinical scenarios, with a low incidence of complications and a high technical success rate.
8:22AM Abstract No. 68
Excimer Laser-Assisted AngiopJasty in Severe Infrapopliteal Disease: A "LACI Equivalent" Update. D.E. Allie, Cardiovascular Institute of the South, Lafayette, LA, USA ·CJ. Hebert·MH. Khan-A.A. Allie·MA. Khan 'CM Walker, et al.
PURPOSE: 12 month major amputation rates in "true limb salvage" (Rutherford class 5-6 with established tissue loss) are reported as > 90% if nonrevascularable and 25% if revascularable. 24 month mortality rates of > 40-50% are reported post amputation and < 50% will ambulate with a prosthesis. The encouraging Laser Angioplasty for ,Critical Limb Ischemia (LAC!) 6 month limb salvage (LS) rate of93% prompted adoption of excimer laser assisted angioplasty as our primary infrapopliteal treatment for "TLS".
AfATERIALS AND METHODS: Between October 2001-August 2003, 62 patients (62 limbs) with Rutherford class 5-6 symptoms presented with severe infrapopliteal disease S167
S168
without single vessel "straight line flow" to the foot. 70 infrapopliteal arteries (lA) were treated including posterior tibial 21170 (30%), peroneal 16170 (23%), anterior tibial 8170 (II %), tibioperoneal trunk 14170 (20%), and mUltiple 11170 (16%). 30/62 (48%) and 22/62 (35%) required superficial femoral artery (SFA) and popliteal artery (PA) laser assisted angioplasty respectively. 5/62 (8%) patients required the "stepby-step" technique.
·RESULTS: Procedural success 59/62 (95 .2%) with 9/62 (14.5%) requiring a secondary reintervention [bypass 2/62 (3 .2%) and repeat laser angioplasty 7/62 (11.2%)] at mean 7 months (range 1-23 months). No periprocedural deaths or major surgical vascular complications. 4/62 (6.4%) minor « 3cm) hematomas. 6 and 12 month mortality rates 3/37 (8.1 %) and 5/24 (21%) respectively. 6 and 12-month LS rates were 34/37 (91.8%) and 20/24 (83 .3%) respectively. Arteries stented included SFA 15/23 (65%), PA 4112 (33%), and LA 7/ 62 (11.2%).
CONCLUSION: Excimer laser assisted angioplasty is safe and effective in achieving 6 and 12 month LS in patients with severe infrapopliteal disease and advanced limb ischemia therefore walTants further investigation.
8:33AM Abstract No. 69
Subintimal Arterial Flossing with Antegrade-Retrograde Intervention (SAFARI) for Subintimal Recanalization. D.J. Spinosa, University o/Virginia Health System, CharlOllesville, VA, USA ·N.L. Harthun'D.L. Cage 'E.A . Bissonette 'D.A. Leung '1.F. Angle, et al.
PURPOSE: To describe the subintimal arterial flossing with antegrade-retrograde intervention (SAFARI) technique to improve technical success for performing subintimal recanalization (SIR) when there is failure to re-enter the distal true lumen, or when there is a limited segment of patent distal target artery available for re-entry.
MATERIALS AND METHODS: SIR was attempted in an antegrade direction in all patients. If re-entry into the distal true lumen was unsuccessful or a short segment of target artery was present, retrograde access was obtained in the distal target artery (popliteal ; anterior tibial/dorsalis pedis, ATIDP; or posterior tibial, PT) and a retrograde subintimal channel was created. A guidewire was used to connect the retrograde and antegrade subintimal channels simultaneously to create a "flossing" guidewire. The subintimal tract was dilated with balloon angioplasty +/- stenting. Limb salvage rates over time were determined and compared to limb salvage performed only by the antegrade approach.
RESULTS: The SAFARI technique resulted in successful SIR creating straight-line flow to the foot in all 21 limbs in which the technque was attempted. Antegrade-retrograde access was performed using the following vessels: femoral- popliteal, II limbs; femoral- ATIDP, 11 limbs; and femoral- PT, I limb (two limbs involved multiple access). All procedures were successful. Limb salvage with SAFARI was 89% (95% CI 72,100%) at six months. These rates compared favorably with limb salvage for antegrade only SIR limbs [Hazard Ratio 0.9 (95% CI 0.1,6.0)].
CONCLUSION: The SAFARI technique was found to be useful for completing SIR when there is failure to re-enter the distal true lumen from an antegrade approach, or when there is a limited distal target artery available for re-entry. The SAFARI technique improves technical success when performing SIR with limb salvage rates comparable to antegrade SIR.
I
8:44AM Abstract No. 70
Predictors of Delayed Outcome Following Kissing-Stent Reconstruction of the Aortic Bifurcation. M.1. Sharajilddin, University o/Iowa Carver College 0/ Medicine, Iowa City, lA, USA'S. Sun 'J.A . Bolton-Smith '1.1. Hoballah' WJ Sharp 'JD. Corson
PURPOSE: Few studies have evaluated the delayed outcomes of "kissing stenting" in aortoiliac occlusive disease. No demographic, risk factor , or stent variables have been shown to influence patency rates of "kissing stents". Our study evaluated the efficacy and delayed outcome of aortobiiliac stent reconsttuction using a variety of modern devices and techniques.
MATERIALS AND METHODS: We retrospective reviewed all stent-reconstruction procedures ofthe aortoiliac bifurcation from January 1998 through June 2002. Outcome variables were compared on "intent-to-treat" basis . Using logistic regression, a number of patient-related, disease-extent, technical, and geometrical variables were evaluated as predictors of restenosis. In particular, we evaluated the effect of "Geometric Mismatch" (determined by aortic anatomy, stent material/design, sizing, and other operator-dependant parameters).
RESULTS: Seventy-six limbs were treated with aortobiiliac kissing stenting in 38 patients. Sixty-eight limbs were diseased, and 8 limbs were stented for protection. Common iliac artery alone was involved in 25 limbs, with extension into the external iliac artery in 43 limbs. Mean maximum stenosis per limb was 79±28 %. Total chronic occlusion was present in 21 limbs. Acute/subacute thrombus was present in 7 limbs. Technical success was achieved in 100% of limbs. Intervention details per limb were as follows: stented length 83±48 cm, number of stents 1.7± 1.0 (range: 1-5), maximum stentdiameter 9.97±0.8 (range: 8-12 mm). Median follow-up was 29 months (range 1-59). Primary clinical benefit was achieved in 35 patients (92%). Primary-assisted clinical benefit was achieved in 36 patients (95%). There were 2 endovascuLar reinterventions. Two other patients underwent surgical reinterventions. Of all variables evaluated, geometric mismatch, female gender, and residual hemodynamic stenosis were found to be significant predictors of restenosis.
CONCLUSION: Stent-reconstruction of the aortoiliac bifurcation in occlusive disease is effective and durable. Geometric mismatch between the stent and the aorta, which is determined by patient and operator dependent factors, may be an important contributor to the development ofrestenosis.
8:55AM Abstract No, 71
Initial Results Using Cryoplasty To Treat Lower Extremity In-Stent Restenosis. JD. Joye, El Camino Hospital, Mountain View, CA, USA 'F.G. St. Goar
PURPOSE: Percutaneous treatment of femoral-popliteal arterial disease has been unsatisfactory. Despite widespread use of stents in these arteries, restenosis rates remain unacceptably high. Cryoplasty has recently demonstrated improved results in treating de novo femoral-popliteal lesions. We report on our initial experience with cryoplasty for instent restenosis (ISR).
MATERIALS AND METHODS: The study cohort consisted of 18 patients with ISR of the superficial femoral or popliteal arteries. Patients with total occlusions were routinely debulked with an atherectomy catheter prior to cryoplasty, whereas those with stenosed vessels were treated with stand-
alone cryoplasty. Cryoplasty was performed at 8 atm and -10 degrees Celsius for 30 seconds per inflation with an appropriately sized PolarCath cryoplasty balloon (CryoVascular Systems, Los Gatos, CA). Clinical follow-up consisted of ankle-brachial indices CABIs) and arterial duplex imaging every 3 months post-procedure.
RESULTS: Patients included 10M/8F with 42% diabetics, 50% smokers, and 33% with complete occlusions. Mean lesion length was 14cm (range 4-40cm). Cryoplasty was successfully performed in all patients with reduction in percent diameter stenosis from a baseline of92% to 22% post-procedure. Preprocedure ABls were 0.65 and improved to 0.89 at 3 months and 0.85 at 6 months . Primary patency at follow-up (mean=7±2 months) was 89%. Late term follow-up will be presented.
CONCLUSiON: Cryoplasty achieved excellent acute angiographic results in a challenging group of patients with ISR offemoral-popliteal arteries. Short-term clinical followup has been encouraging. If late results in patients with ISR match the favorable outcomes seen in de novo lesions, cryoplasty may improve the treatment of lower extremity ISR.
Scientific Session 14 Oncology
Saturday, March 27, 2004 8:00 AM - 9:30 AM Moderator(s): Richard Owen, MD
LUigi Solbiati, MD
8:00AM Abstract No. 72
Combination Radiofrequency and Cryoablation Using a Novel Design in an Ex-Vivo Bovine Liver Model. A. Hines-Peralta, Beth israel Deaconess Medical Center, Boslon, MA, USA·Z. Lhl'S. Solazzo K Dalal·S. Goldberg
PURPOSE: To determine whether combining radiofrequency and cryoablation using a novel combined energy applicator yields greater coagulation than either modality alone ..
MATERiALS AND METHODS: Radiofrequency and cryoablation were performed independently and then combined in an ex-vivo bovine liver rnodel using a novel applicator design. The device consists of a bipolar RF ablation system with 2.5cm active and return poles as well as two independentlycontrolled cyroablation nozzles embedded in the 18-gauge shaft. Ablations were performed under optimal parameters with a single applicator, 3-applicator arrays spaced 3cm and 3.5cm apart, and a 4-applicator array spaced 4cm apart. Response to duration of applied energy was achieved by performing ablations between 5 and 40 minutes in a single RFI Cryo applicator. The resulting areas of tissue coagulation were measured and compared.
RESULTS: For a single applicator, greater tissue coagulation was achieved using combination RF/cryo (3 .6cm ±OAcm after 15 minute ablation, 0.65 amps RF current, and 2900psi argon) that was significantly larger than a sum of each individual modality (RF: 1.5cm ±0.3cm, Cryoablation: 0.8cm ±0.3cm) (p<0.005). Multi-applicator arrays achieved greater tissue coagulation with the 3-applicator array yielding 6.5cm ±0.3cm and 7.lcm ±O.5cm in diameter (3.0cm and 3.5cm spacing, respectively), and the 4-applicator array yielding 93cm ±0.2cm of contiguous coagulation. Tissue coagulation from applied energy over time yielded a sigmoidal curve with 80% of coagulation achieved in the first 15 minutes of combined RF/cryo (3.6cm ±OAcm after IS minutes and 4Acm ±O.I cm after 40 minutes).
CONCLUSiON: Combination radiofrequency and cryoablation achieves extensive tissue coagulation in an exvivo liver model through a synergy of the two modalities. Given tissue coagulation of up to 9.3cm ±0.2cm in a 4-applicator array, this novel device warrants further study.
Arterial Embolization and Ablation Is Comparable to Surgical Resection in Solitary Hepatocellular Carcinoma. MA. Maluccio, Memorial Sloan Keuering Cancer Center, New York, NY, USA ·A.M. Covey-R. Gandhi·GJ. Getrajdman .c. Sofocleous . K. T Brown, et al.
PURPOSE: The vast majority of hepatocellular cancers (HCC) present in patients with underlying liver dysfunction, making surgical resection available to only a subset of patients with adequate hepatic reserve. In this study we sought to investigate our experience treating solitary foci ofHCC by bland arterial embolization plus ablation (radiofrequency ablation or alcohol injection) compared to a similar subgroup of patients undergoing surgical resection.
MATERIALS AND METHODS: A retrospective review of all patients with solitary BCC undergoing either surgical resection or bland embolization and ablation between January 1996 and August 2002 was performed. Only patients with lesions < 7cm were included. Underlying liver disease was documented according to the Okuda classification. Recurrence free survival and overall survival were calculated using the Kaplan-Meier method . Differences in survival was determined using the log rank test.
RESULTS: There were 40 patients who underwent surgical resection and 33 patients who underwent embolization and ablation during the study period. Age, gender, and size of the treated lesion were not significantly different between the groups. There were significantly more Okuda stage II patients in the embolization and ablation group compared to the surgery group (36% vs 0% respectively, p<O.OOO I). The median follow up was 22 months and 23 months for the embolization and surgery groups respectively. Median recurrence free survival was 10 months in the embolization group and 12.5 months in the surgery group. The 1,2,4 and 5 year actuarial survival for the embolization/ablation group was 97%,83%,77% and 56% and for the surgery group was 81%, 70%, 70% and 57% respectively (p=0.22 by log rank). Of the 19 surgical patients with recurrences, 7 underwent subsequent embolization and 417 remain alive with no evidence of disease at 12, 16, 19 and 30 months from the date of recurrence; 2 others are alive with disease.
CONCLUSiON: Bland arterial embolization in combination with ablation is effective at treating solitary BCC lesions and affords patients survival benefits on par with patients undergoing surgical resection.
