2 Doubling times 01 SMC at different IUdR concentration Concentration Doubling Time (hours) Control 51 ,5 5~M 60A 10~M 734 20~ 811' 30~M 940' 40~M 104,8' • Compared With oontrol, P<0,05

CONCLUSION' The peak time to uptake IUdR was 5 days and optimal concentration of IUdR was between I O!lM to 20!lM for proliferating SMCs to uptake in vitro. IUdR could inhibit the SMCs' proliferation.

Scientific Session 9 Renal Interventions

Friday, March 26, 2004 4:30 PM - 6:00 PM Moderator(s): Alan H. Matsumoto. 1\1D

Chet R. Rees, MD

4:30PM

FEATUIU:!) ABSTRACT

Commentator: Timoth) I', \Iurph), i\\D

Abstract No, 43

IRena) Artery Stenj)sis (RAS) as an Independent RisJ{ Factor for (:ardiovascular Events, I. Shahin, Columbia-Pre hyrerii.1n Medical enter, New York,/'lr. USA-J.H. Rundback·Z. Ha ·/ca/·J. Weintraub '.1. Susman ·D. Mobl y

PURPOSE: To evaluate the association of cardiovascular disease (CVP) with angiographically proven RAS.

MATERIALS AND METHODS: Aortograms frolll 300 patients were retrospectively reviewed and the presence of IVI.S >50% was scored (143 evaluable). Using the hospital Medical Infom1atioll System. coincident ICDs for }-ITN, DM, E RD. ulU able angina, chronic ischemic hean dL case and CHF were recordcp. nivariate and mullivariate correlative analysis of CVD prevalence. in patients wI and wlo RAS was performed. , "

RESULTS:

Total n 143 HTN 117 DM 58 E8RD 22 UA 13 CH ISCHEM HD 58 CHF 39 AnyCVD

-t>lo RAS (%J Unital RAS (%) p 92 36 69 (7.5) 34 (94) 0.01 36 (39) 14 (39) 0,98 9 (10) 7(19) 0.15 5 (5) 6 (17) 0.07 33'(36) 14 (39) 0.75 22 (24) 9 (25) 0.9

041

. Bilal.RAS (%) p 15 . 14(93) 0,18 6 (53) 0.4 6(40) 0.007 2(13) 025 12 (BOY 0.002 8 (~3) 0.029

P:012

CONCLUSION: Bilateral RAS i as ociated with a higher likelihood of chronic ischemic heartdisc:ase, CHF and ESRD when compared wi tl; patients withou! RA . Unilateral RAS is associated with HTN and a. trend towards unstable angina.

4:45PM Abstract No, 44

Long-Term Outcome of Renal AngiopIasty, H. Klingenstiema, Sahlgrenska University Hospital, Goteborg, Sweden-M. Annerstedt'G. Jensen-M. Delle'L. Lonn-M. Hellstrom

PURPOSE: To determine long-term radiological and clinical effects of renal angioplasty (PTRA) in patients with hypertension.

MATERIALS AND METHODS: A prospective five-year follow-up of patients subjected to PTRA in 1994-96 (n=1 06) was performed, assessing renal artery patency by digital subtraction angiography including intra-arterial pressure

measurements (or MRA), as well as blood pressure, renal function and quality of life assessments.

RESULTS: Seventeen patients had died during follow-up and 30 were unwilling to participate, leaving 59 patients (32 males) with a mean age of 64 years (26-82 years) for follow-up. Twenty-four (41 %) of the 59 patients had suffered cardiovascular events before PTRA or during follow-up. DSA showed >50% lumen reduction in 10 of 44 patients (22%) and six of them had >5 mm pressure gradients. Eight patients declined DSA and four of seven patients who had MRA had restenosis >50%. Systolic and diastolic blood pressure were lower at 5-year follow-up (161±23 mm Hg systolic and 84±9 mm Hg diastolic) than at the time ofPTRA (170±30 mm Hg systolic and 90±17 mm Hg diastolic) . Hypertension teatmen! index (based on number and dosage of antihypertensive drugs) decreased from 17±9 to 9±6. Glomerular filtration rate was unchanged (63±21 mLlmin and 63±25 mLimin, respectively). More than 2/3 of the patients rated their physical, mental and social well-being as good or excellent five years after PTRA.

CONCLUSION: Renal artery stenosis is associated with significant cardiovascular co-morbidity. Long-term outcome of PTRA appears favorable with regard to blood pressure control, renal function and quality of life.

4:56PM Abstract No, 45

Designing Renal Artery Protection Devices: Consideration of Main Renal Artery Anatomy, J.e. Hellinger, Stanford University Medical Center, Stanford, CA, USA 'A.H. Pezeshkmehr'M. Razavi'G.D. Rubin

PURPOSE: Renal artery protection devices may offer a role in minimizing the potential burden of distal micro-embolization incurred during renal artery stenting. The purpose of our study was to provide quantitative renal artery anatomic data, using multidetector-row CT angiography (MDCTA), which could facilitate design of a protection device specific to the renal arterial system.

MATERlALS AND METHODS: Abdominal MDCTA studies from 86 patients (62M:24F, mean age 68) were retrospectively analyzed. Exams were performed on 8 or 16 channel MDCT. Scan parameters included the following: 1.25 collimation, 1.25mm slice thickness, 1.35-1.375 pitch, and 0.8mm reconstruction interval. Studies were processed on an Advantage Windows 4.0 workstation (GE Medical Systems, Milwaukee, WI). Three anatomical parameters were measured: I) distance ofthe main renal artery to first order bifurcation, defined as segment ODe (R-I) distance; 2) diameter of R-I 5mm proximal to !.'he bifurcation, defined as the deployment diameter; and 3) main renal artery origin angle. Paired student t-test was applied to determine statistical significance.

RESULTS: For the right renal artery, mean R I distance, deployment diameter, and origin angle were 43 ± 15mm (range 12.1-79.6mm), 5.8 ± 1.0mm (range 4.0-7.9mm), and 60 ± 17° (range 19.3-11 0°), respectively. For the left renal artery, mean RI distance, deployment diameter, and origin angle were 32.6 ± 13.7mm (range 18.2-69.2mm), 5.75 ± 1.0mm (range 4.2-7.95mm), and 90 ± 19° (range 62-131 °), respectively. Differences between right and left mean R 1 distances, as well as the origin angles, achieved statistical significance (p<.00 I).

CONCLUSION: Normal renal artery anatomical assessment with MDCTA demonstrated variability between right and left renal arteries for R I distances and origin angles. This data should be considered when designing a renal artery protection device.

S159

S160

5:07PM Abstract No. 46

Transplant Renal Artery Stenosis: Outcome FoJlowing Percutaneous Intervention. . D.K. Rajan, University Health Network - University of Toronto, Toronto, ON, Canada ·T.W Clark·M Robinette·S. Stavropoulos

PURPOSE: To assess the outcome of percutaneous transluminal angioplasty (PTA) and stenting as the primary treatment for transplant renal artery stenosis (TRAS).

MA TERIALS AND ¥ETHODS: A retrospective chart review of renal artery angiograms performed for suspected TRAS from April 1997 to July 2003 was conducted. Reviewed parameters included technical success, date of transplantation, dates of intervention, mean arterial bLood pressure, number of blood pressure medications and creatinine levels.

RESULTS: A totaL of 18 allografts underwent 19 interventions. Technical success rate ofPTA/stenting was 100% and clinical success rate was 95% (18 of 19 interventions). Eleven allografts underwent PTA alone with seven undergoing PTA and stent insertion. The mean pre-PTA/stent creatinine value for twelve allografts with elevated creatinine was 2.8 mg/dL ± 1.4 (SD) versus a I-month post-PTA value of2.2 mg/dL± 0.7 (P=0.03). Of six allografts that presented with hypertension, significant improvements were seen in pre-intervention and 1 month mean systolic (174 vs. 135 mmHg, P = 0.003) and diastolic (99 vs. 82 mmHg, P=0.02) pressures. These patients required a mean of 2.3 medications for pressure control prior to intervention compared to 1.0 at 1 month following intervention (P=0.002). Mean follow-up time was 27 months. Of the seven allografts that underwent stenting, all 7 remain patent. One major complication of a puncture site pseudoaneurysm occurred (1/19, 5%).

CONCLUSION: Primary treatment of TRAS with PTA/ stenting has good intermediate-term patency, and is associated with significant early improvement in blood pressure and creatinine. No conclusions can be dtawn as to whether stenting provides a clinical benefit over angioplasty in this setting.

Abstract No. 47

Succesful Treatment of Early Non-Anastomotic Transplant Renal Artery Stenosis. A. Trebelev, Albert Einstein Medical.Center, Philadelphia, PA , USA .ps. Brady·J. Oleaga·G. Ortiz·R. Zaki·K. Nota . PURPOSE: Transplant renal artery stenosis (TRAS) is a well­known vascular complication after kidney transplant causing graft dysfunction and HTN. Eaily presentation of distal TRAS has been scarcely reported . We present a series of 5 patients with early presentation of non-anastomotic TRAS treated with stent placement. During the I-year period between July 1, 2002 and June 30, 2003; 80 patients received 87 kidney transpLants in ourcenter:

MATERIALS AND METHODS: Medical records of the 80 patients and their donors were reviewed. Patients with TRAS were compared with the remainder of the cohort. Creatinine and blood pressure values of the TRAS patients prior to diagnosis, at the time of diagnosis and after treatment were compared using paired t-test analysis. Doppler ultrasound was performed on all 10 patients and was suggestive ofTRAS in 8 patients. MRA or bidimensional angiography excluded the diagnosis in 2 patients. Non-anastomotic TRAS was diagnosed in 6 recipients of cadaveric grafts: .4 women and 2 men. I patient had a kinked artery causing significant obstruction to blood flow, this patient is being treated medically with good outcome and was not included in the

I

study group. The only significant difference between th'e groups was the presence of diabetes (p<0.05) . The mean time from transplantation to diagnosis ofTRAS was 90±37 days (26-120).

RESULTS: The five patients were treated with percutaneous transluminal angioplasty andstent placement. The treatment was successful in all the patients. MBP, SBP and serum Cr after treatment were significatively lower than at diagnosis (p<0.05). All patients with TRAS have working grafts and no evidence of recurrence at a mean follow up of204±85 days.

CONCLUSION: We did not find a significant relationship of TRAS with factors previously described. However we found a significant association of TRAS with DM (p<0.05). Transluminal stent placement is a safe and effective way of treating TRAS. Longer follow up is need to determine long term efficacy of this treatment.

5:29PM Abstract No. 4~

Cross Sectional Renal Artery MRI: Comparison of an Intravascular Guidewire Coil with an External Body Surface Coil. ' B.E. Schirf Northwestern University, Chicago, IL, USA-J.D. GreewR. Tang·K. Sato·D. Li·R.A. Omary, et al.

PURPOSE: Internal intravascular guidewire coils have been employed for device tracking during MRl-guided endovascular procedures. We tested the hypothesis that internal coils improve signal-to-noise ratio (SNR) and contrast-to-noise ratio (CNR) compared to conventional external coils for cross sectional lumen imaging of swine renal arteries.

MATERIALS AND METHODS: We placed 6 F percutaneous vascular sheaths in the femoral arteries of three swine (36-57 kg). Each pig was transferred to a 1.5T Sonata scanner where, 6 F angiographic catheters were introduced under real-time MRl guidance into the renal arteries. We advanced a Surgivision 0.030" diameter nitinol guidewire containing an active internal' radiofrequency coil into each renal artery. Cross section positions (n= 18) were imaged with a phased array body surface coil or the internal guidewire coil. For each position, Fast Low Angle SHot images were obtained using the a) internal guidewire coil (4 signal avg. 's; scan time 20s ), b) internal coil (no avg.'s; scan time 5s), and c) externaL surface coil (4 signal avg's; scan time 20s). In-plane spatial resolution for each image was 0.4 x 0.4 mm2• We calculated SNR and CNR using regions-of-interest signal measurements from within each renal artery, adjacent background tissue, and air. Paired comparisons between each of the three acquisitions were performed separately for SNR and CNR values. We assessed statistical differences using paired t-tests (alpha=0.05) .

RESULTS: Mean SNR (±SD) was: internal coil (4 avg.'s) 70.2 ±18.4, internal coil (no avg.'s) 30.6 ±7.80, and external coil (4 avg.'s) 5.67 ±1.94. Mean CNR was: internal coil (4 avg.'s) 60.8 ±17.8, internal coil (no avg.'s) 25 .8 ±7.23, and external coil (4 avg. 's) 3.50 ±1.41. The intravascular coil (no or 4 avg. 's) improved SNR and CNR compared to the external coil (p<O.OO 1).

CONCLUSION: Intravascular coils significantly improve SNR and CNR compared to e~ternal body surface coils during high spatial resolution, cross sectional imaging of swine renal arteries. Given that intravascular coils maintain SNR and CNR , while reducing imaging time, they may potentially be used to . improve stenosis detection and vessel wall imaging during MRI-guided endovascular procedures.