VASCULAR—ARTERIALDiagnosis

Mural Aortic Thrombi: An Impor-tant Cause of Peripheral Emboli-zation P. U. Reber, A. G. Patel, E.Stauffer, et al. J Vasc Surg 1999;30:1084–1089. (Horst W. Kniemeyer,Professor of Surgery and Chairman,Division of Vascular Surgery, Insel-spital University of Bern, Bern CH-3010, Switzerland)● Purpose: Arterial thromboembolismin patients with an unknown source ofembolization is still associated with sig-nificant morbidity and mortality. Theadvent of trans-esophageal echocardiog-raphy (TEE) and magnetic resonanceimaging (MRI) and the more frequentuse of computed tomography (CT) haveled to the identification of mural aorticthrombi (MAT) as a source of distal em-bolization in a much higher proportionof patients than previously appreciated.The incidence, diagnosis, and treatmentof patients with MAT is reported. Meth-ods: In a prospective study, from Janu-ary 1996 to December 1998, 89 patientswith acute embolic events underwentan extensive diagnostic workup, con-sisting of TEE, CT, or MRI, to detectthe source of embolization. Patients inwhom the heart (n � 51), occlusive aor-toiliac disease (n � 16), or aortic aneu-rysms (n � 12) was identified as thesource of embolization were excluded.Results: Five female and three malepatients, with a median age of 63 years(range, 35 to 76 years), with bilateral orrepetitive embolic events resulting fromMAT were identified, representing 9%of all patients with arterial thrombem-bolism. All patients had several riskfactors for atherosclerosis, but only oneyoung patient had a single risk factorthat promoted thrombosis. Successfulpercutaneous catheter aspiration embo-lectomy was performed in six patients.The remaining two patients underwentsurgical thrombo-embolectomy. A be-low-knee amputation had to be per-formed in two patients, thus represent-ing a morbidity of the primary treat-ment of 25%. MAT of equal value weredetected in the ascending (n � 1) andthoracic aorta (n � 3) by means ofTEE, CT, or MRI. MAT in the abdomi-nal aorta (n � 4) were identified bymeans of CT and MRI. Surgical re-

moval of MAT was performed in sevenpatients by means of graft replacementof the ascending aorta (n � 1), openthrombectomy of the descending aorta(n � 2), and thrombendarterectomy ofthe abdominal aorta (n � 4), withoutintraoperative or post-operative compli-cations. No recurrence of MAT occurredduring a median follow-up period of 13months (range, 4 to 24 months). Con-clusion: MAT represent an importantsource of arterial thrombembolism. Adiagnostic workup of the aorta, prefera-bly by means of CT or MRI, should beperformed in all patients in whomother sources of embolization have beenruled out. The ideal therapeutic ap-proach to these patients still awaitsprospective evaluation. However, basedon our experience, MAT can be success-fully treated with a definitive surgicalprocedure in selected patients, with lowmortality and morbidity.AUTHORS’ ABSTRACT

Intimal Tear Without Hematoma:An Important Variant of AorticDissection That Can Elude Cur-rent Imaging Techniques LarsG. Svensson, Sherif B. Labib, AndrewC. Eisenhauer, et al. Circulation1999;99:1331–1336. (L.G.S., Divisionof Cardiovascular Surgery, LaheyHitchcock Clinic, 41 Mall Rd., Burl-ington, MA 01805)● Background: The modern imagingtechniques of transesophageal echocar-diography, CT, and MRI are reported tohave up to 100% sensitivity in detect-ing the classic class of aortic dissection;however, anecdotal reports of patientdeaths from a missed diagnosis of sub-tle classes of variants are increasinglybeing noted. Methods and Results: In aseries of 181 consecutive patients whohad ascending or aortic arch repairs, 9patients (5%) had subtle aortic dissec-tion not diagnosed preoperatively. Allpreoperative studies in patients withmissed aortic dissection were reviewedin detail. All 9 patients (2 with Marfansyndrome, 1 with Takayasu’s disease)with undiagnosed aortic dissection hadundergone �3 imaging techniques,with the finding of ascending aortic di-latation (4.7 to 9 cm) in all 9 and signif-icant aortic valve regurgitation in 7. In6 patients, an eccentric ascending aor-tic bulge was present but not diagnosticof aortic dissection on aortography. Atoperation, aortic dissection tears were

limited in extent and involved the in-tima without extensive undermining ofthe intima or an intimal “flap.” Eighthad composite valve grafts inserted,and all survived. Of the larger series of181 patients, 98% (179 of 181) were30-day survivors. Conclusions: In pa-tients with suspected aortic dissectionnot proven by modern noninvasive im-aging techniques, further study shouldbe performed, including multiple viewsof the ascending aorta by aortography.If patients have an ascending aneu-rysm, particularly if eccentric on aor-tography and associated with aorticvalve regurgitation, an urgent surgicalrepair should be considered, with excel-lent results expected.AUTHORS’ ABSTRACT

MRA Diagnosis

Evaluation of Breath-Hold Con-trast-Enhanced 3D Magnetic Res-onance Angiography Techniquefor Imaging Visceral AbdominalArteries and Veins MalihaSadick, Steffen J. Diehl, Karl-JurgenLehmann, et al. Invest Radiol 2000;35:111–117. (M.S., Institute of Clini-cal Radiology, Klinikum Mannheim,Faculty of Clinical Medicine Mann-heim-University of Heidelberg, The-odor Kutzer-Ufer 1–3, D-68167 Mann-heim, Germany)

● Rationale and Objectives: Toevaluate the diagnostic value ofbreath-hold contrast-enhanced 3Dmagnetic resonance angiography(MRA) for assessment of the visceralabdominal arteries and veins in pa-tients with suspected abdominal neo-plasms. Methods: Twenty-one patientsunderwent MR imaging on a 1.5 Tunit using a body phased-array coil.MRA was performed with a 3D-FLASH sequence (TR 3.8 ms, TE 1.3ms, flip angle 25°, acquisition time 20seconds), 8 to 12 seconds after an in-travenous bolus injection of Gd-DTPA.The acquisition delay between the ar-terial and the portal venous phasewas 12 seconds. The image qualityand the degree of vascular involve-ment were evaluated using coronalsource images and maximum inten-sity projection reconstructions. Diag-nosis was confirmed by surgery/histol-ogy. Results: Image quality was opti-mal in more than 85% of the patients

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(19 of 21 arterial phase and 17 of 21portal venous phase). MRA correctlypredicted vascular status in 20 of 21patients (95%), with complete concor-dance between MRA results and sur-gical findings. In one patient withchronic pancreatitis, MRA demon-strated a false-positive finding thatcould not be confirmed surgically.Conclusions: Breath-hold contrast-enhanced 3D-MRA is a valuable tech-nique for assessing visceral abdomi-nal arteries and veins.AUTHORS’ ABSTRACT

Stents

Health-Related Quality of Life Af-ter Angioplasty and Stent Place-ment in Patients With Iliac ArteryOcclusive Disease: Results of aRandomized Controlled ClinicalTrial Johanna L. Bosch, Yolandavan der Graaf, Maria G.M. Hunink,for the Dutch Iliac Stent Trial StudyGroup. Circulation 1999;99:3155–3160.(M.G.M.H., Program for the Assess-ment of Radiological Technology (ARTprogram), Department of Epidemiologyand Biostatistics and Department ofRadiology, Erasmus Medical CenterRotterdam, Room EE21-40a, PO Box1738, 3000 DR Rotterdam, Nether-lands)● Background: To assess the quality oflife in patients with iliac artery occlu-sive disease, we compared primarystent placement versus primary angio-plasty followed by selective stent place-ment in a multicenter randomized con-trolled trial. Methods and Results:Quality-of-life assessments were com-pleted by 254 patients in a telephoneinterview. Assessment measures con-sisted of the RAND 36-Item HealthSurvey 1.0, time tradeoff, standardgamble, rating scale, health utilitiesindex, and EuroQol-5D. The interviewswere performed before treatment andafter 1, 3, 12, and 24 months. When the2 treatments were compared, no signifi-cant difference was observed (P �0.05). All measurements showed a sig-nificant improvement in the quality oflife after treatment (P � 0.05). TheRAND 36-Item Health Survey mea-sures physical functioning, role limita-tions caused by physical problems, andbodily pain and the EuroQol-5D werethe most sensitive to the impact of re-vascularization. Conclusions: Health-related quality of life improves equallyafter primary stent placement and pri-mary angioplasty with selective stentplacement in the treatment of intermit-

tent claudication caused by iliac arteryocclusive disease.AUTHORS’ ABSTRACT

Delayed Treatment of TraumaticRupture of the Thoracic AortaWith Endoluminal Covered StentH. Rousseau, P. Soula, P. Perreault,et al. Circulation 1999;99:498–504.(H.R., Service de Radiologie, CHURangueil, 1, Avenue Jean Poulhes,31403 Toulouse Cedex 4, France)● Background: Stent grafting isemerging as a new treatment for sev-eral pathological conditions involvingthe thoracic aorta. We studied thefeasibility and safety of this techniquefor delayed treatment of ruptures ofthe aortic isthmus. Methods and Re-sults: Nine patients (14 to 76 yearsold; mean, 37 years; male/female ra-tio, 8/1) underwent stent grafting ofthe aortic isthmus in subacute (n � 5)or chronic (n � 4) aortic traumaticrupture after a motor accident. Insubacute ruptures, this treatmentwas delayed (1 to 8 months; mean, 5.4months) because of the severity ofother associated injuries. Stent graft-ing was technically successful (de-fined as complete exclusion of thepseudoaneurysmal sac) in all pa-tients. Short-term fever and biologicalinflammatory syndrome occurred in 3patients. Two major complications oc-curred: in 1 patient, an early occlu-sion of the left subclavian artery wastreated by placement of 2 Palmazstents. In another patient, an atelec-tasis related to an increase of preex-isting compression of the left mainbronchus by the pseudoaneurysmalsac was successfully treated by tem-porary placement of an endobronchialsilicone stent. Mean follow-up was11.6 months (range, 3 to 21 months).Thrombosis of the pseudoaneurysmalsac was found in all patients. Conclu-sions: In the absence of available ex-tended follow-up about the safety andeffectiveness of endovascular grafting,this approach seems to be a viabletherapeutic option for traumatic rup-ture of the aortic isthmus, but appro-priately controlled prospective studiesare needed before we can recommendits widespread use.AUTHORS’ ABSTRACT

Endovascular Stent-Grafts

Intravascular Ultrasound Evalua-tion of Peripheral Arterial Stent-Grafts Stefan Muller-Hulsbeck, Hel-mut Schwarzenberg, Alfred Hutzel-

mann, et al. Invest Radiol 2000;35:97–104. (S.M.H., Department of Radiology,University Hospital, Arnold-Heller-Straße 9, 24105 Kiel, Germany)

● Rationale and Objectives: Toevaluate neointimal hyperplasia,plaque distribution, and morphologicfeatures of peripheral arterial stent-grafts with intravascular ultrasound(IVUS). Methods: Twenty-three pa-tients with stenoses or occlusions ofthe pelvic or femoral arteries weretreated with 31 stent-grafts. Angiog-raphy and IVUS of the stented arterywere performed 13.9 � 9.7 monthsafter stent implantation. Maximumin-stent restenosis was measured byIVUS. Plaque composition and lesiontopography were also assessed. Re-sults: The maximum in-stent resteno-sis was 53.2 � 26.5% for the femoraland 14.2 � 10.1 for pelvic arterialstent-grafts. Predilection sites of max-imum neointimal tissue accumulationwere the edges of the femoral stent-grafts. Only small amounts of neointi-mal hyperplasia were found in thestent-graft edges. No predilection sitefor maximum in-stent restenosis wasfound for the pelvic arterial stent-grafts. Conclusions: Predilection sitesof maximum in-stent restenosis werethe edges of femoral stent-grafts incontrast to pelvic stent-grafts. Femo-ral stent-grafts showed significantlyhigher graded stenoses with IVUSthan iliac stent-grafts. The authors’findings at IVUS did not change thetreatment plan in these patientstreated with stent-grafts.AUTHORS’ ABSTRACT

Can Knitting Structure Affect Di-lation of Polyester BifurcatedProstheses? A Randomized Studywith the Use of Helical ComputedTomography Scanning Olivier A.Goeau-Brissonniere, Salah D. Qa-nadli, Arnaldo Ippoliti, et al. J VascSurg 2000;31:157–163. (O.A.G.B., Ser-vice de Chirugie Vasculaire, HopitalAmbroise Pare, 9 avenue Charles deGaulle, 92104 Boulogne-BillancourtCedex, France)● Purpose: The aim of this study wasto prospectively evaluate the postop-erative dilation of two types of knittedpolyester arterial prostheses with theuse of helical computed tomographicscanning. Methods: Thirty-four pa-tients who underwent aortoiliac oraortofemoral bifurcation grafting wererandomized to receive a collagen-sealed warp-knitted polyester graft (n� 16) or a gelatin-sealed Koper-knitted polyester graft (n � 18). Al-

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terations in size of all parts of thegrafts were evaluated by helical com-puted tomographic scanning at post-operative day 8, at 3 months, and at 6months. Results: On postoperativeday 8, the mean dilation of the Koper-knitted grafts was 18% � 8% for thestem and 15% � 12% for the limbs.At the same time period, the meandilation of warp-knitted grafts was27% � 13% for the stem and 33% �18% for the limbs. No increase ingraft dilation was observed at 3 and 6months. Despite the wide range ofvalues among patients with the samegraft type, at each time interval, theKoper-knitted grafts dilated signifi-cantly less than the warp-knittedgrafts (P � .05). Conclusion: In thisrandomized study, helical computedtomographic scanning was an accu-rate technique with which to assessgraft dilation. For a 6-month fol-low-up interval, the Koper-knittedpolyester structure dilated less thanthe warp-knitted structure. Longer-term serial scans should allow a bet-ter understanding of the clinical sig-nificance of graft dilation.AUTHORS’ ABSTRACT

Hospital Cost of Endovascularversus Open Repair of AbdominalAortic Aneurysms: A MulticenterStudy W. Charles Sternbergh IIIand Samuel R. Money. J Vasc Surg2000;31:237–244. (W.C.S., AltonOchsner Medical Foundation, 1514Jeffereson Highway, 8N, New Or-leans, LA 70121)● Background. Technology-driven in-novation in medicine is frequently as-sociated with higher costs than con-ventional therapy. A significantlyhigher cost for endovascular ($21,250,n � 190) versus open abdominal aor-tic aneurysm (AAA) repair ($12,342, n� 60) was suggested by a direct costanalysis of patients in a multicentertrial. Estimated inpatient costs (notcharges) incurred nationwide by hos-pitals for endovascular and open re-pair of AAA were studied to validatethese observed trends. Methods: Aretrospective analysis of 131 patientsundergoing endovascular AAA repairwas compared with 49 patients un-dergoing open repair as part of a Foodand Drug Administration phase IIprospective multicenter clinical inves-tigation (AneuRx-Medtronic). A modelto estimate costs was constructed us-ing important clinical descriptors ofthese patients. These clinical charac-teristics where then matched withthose from 22,460 patients undergo-

ing AAA repair obtained from a largenational database (Medicare ProviderAnalysis and Review). Estimated hos-pital cost was then assigned to eachstudy patient according to the na-tional average of the total hospitalcosts for the respective matched pa-tients in Medicare Provider Analysisand Review. Results: Total inpatienthospital costs of endovascular repairwere significantly higher than that ofopen repair ($19,985 � 7396 versus$12,546 � 5944, respectively, P�.0001). Endograft device cost($10,400) accounted for 52% of thetotal cost of endovascular repair. The1999 mean blended Medicare reim-bursement for AAA repair was$18,989. Conclusion: In this early de-velopment stage, hospital cost for en-dovascular AAA repair is significantlygreater than open repair when devicecost greatly exceeds $5,000. Althoughincremental reductions in cost of en-dovascular repair may be anticipatedif use of diagnostic studies, operatingtime, and length of stay decrease, de-vice cost has the single greatest im-pact on the expense of endovascularAAA repair. At current device pricing,mean blended Medicare reimburse-ment does not cover the cost of endo-vascular AAA repair.AUTHORS’ ABSTRACT

Vascular Surgery

Cost-effectiveness of Surgery forSmall Abdominal Aortic Aneu-rysms on the Basis of Data fromthe United Kingdom Small Aneu-rysm Trial Marc L. Schermerhorn,John D. Birkmeyer, David A. Gould,et al. J Vasc Surg 2000;31:217–226.(Jack L. Cronenwett, Department ofSurgery, Dartmouth-Hitchcock Medi-cal Center, Lebanon, NH 03756)● Purpose: Although the United King-dom small aneurysm trial reported nosurvival benefit for early operation inpatients with small (4.0–5.5 cm) ab-dominal aortic aneurysms (AAAs), thetrial lacked statistical power to detectsmall but potentially meaningfulgains in life expectancy, particularlyfor specific subgroups. We used deci-sion analysis to better characterizethe potential benefits and cost-effec-tiveness of early surgery. Methods:We used a Markov model to assessthe marginal cost-effectiveness (incre-mental cost per quality-adjusted lifeyear �QALY� saved) of early surgeryrelative to surveillance for smallAAAs, using data from the UK Trial.

Subgroup analyses were performed bypatient age and AAA diameter. Sensi-tivity analysis was used to evaluatethe effect of elective operative mortal-ity on cost-effectiveness. Results: Inour baseline analysis, early operationsprovided a small survival advantage(0.14 QALYs) at a small incrementalcost of $1,510. Thus, despite a smallsurvival benefit, early surgery ap-peared cost-effective ($10,800/QALY).The small cost differential resultedfrom the large proportion of patientswho underwent surveillance, whoeventually underwent AAA repair,and therefore incurred the cost of thesurgical procedures. The survival ad-vantage and cost-effectiveness of earlyoperation increased with lower opera-tive mortality, younger age, andlarger AAA diameter. Conclusion: De-spite the negative conclusions of theUK trial, early surgery may be cost-effective for patients with smallAAAs, particularly younger patients(�72 years of age) with larger AAAs(�4.5 cm). Because the gains in lifeexpectancy are relatively small, how-ever, clinical decision making shouldbe strongly guided by patient prefer-ences.AUTHORS’ ABSTRACT

Thrombolysis

Rheolytic Hydrodynamic Throm-bectomy for Percutaneous Treat-ment of Acutely Occluded Infra-aortic Native Arteries and BypassGrafts: Midterm Follow-Up Re-sults Stefan Muller-Hulsbeck, MarcKalinowski, Martin Heller, et al. In-vest Radiol 2000;35:131–140. (S.M.H.,Department of Radiology, UniversityHospital. Arnold-Hefler-Straße 9,24105 Kiel, Germany)

● Rationale and Objectives: Toevaluate the efficacy of a rheolyticthrombectomy catheter (RTC) fortreatment of acutely occluded infra-aortic native arteries and bypassgrafts and to determine midterm pri-mary patency, death, and amputa-tion-free survival rates. Methods:From March 1995 to September 1997,112 patients with occluded arteries orbypass grafts were primarily treatedwith RTC at two centers. Thrombusremoval was evaluated by two angiog-raphers. Results: More than 75% ofthe thromboembolic material could beremoved with RTC alone. Mean acti-vation time of RTC was 280 � 163seconds. Residual mural or organizedthrombi (29%) required adjunctive

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fibrinolytic therapy or aspirationthrombectomy. Remaining stenoseswere treated with percutaneous trans-luminal angioplasty and additionalstent implantation. For acute reocclu-sions, surgical intervention was re-quired. Technical success after theentire procedure was 88.4%. RTC-as-sociated complications included distalembolization, dissection, vessel perfo-ration, and technical failure of RTC.Mean follow-up time was 14.8months � 11.5, rates of primary pa-tency, secondary patency, death, andamputation-free survival were 60%,84%, 16%, and 75% after 2 years, re-spectively. Conclusions: RTC is arapid and efficient technique for me-chanical thrombectomy of acutelythrombosed native leg arteries andbypass grafts. Midterm results arecomparable to the results of alterna-tive treatment modalities such asFogarty balloon thromboembolectomyor local fibrinolysis.AUTHORS’ ABSTRACT

Percutaneous Transluminal Ther-apy of Occluded Saphenous VeinGrafts: Can the Challenge Be MetWith Ultrasound Thrombolysis?Uri Rosenschein, Georg Gaul, Rai-mund Erbel, et al. Circulation 1999;99:26–29. (U.R., Catherization Labo-ratory, Department of Cardiology, TheTel Aviv Sourasky Medical Center, 6Weizman St, Tel Aviv 64239, Israel)● Background: Percutaneous translumi-nal treatment of a thrombotic veingraft yields poor results. We have pre-viously reported our experience withtransluminal percutaneous coronaryultrasound thrombolysis (CUT) in thesetting of acute myocardial infarction(AMI). This report describes the firstexperience with ultrasound thromboly-sis in thrombus-rich lesions in saphe-nous vein grafts (SVGs), most of whichwere occluded. Methods and Results:The patients (n � 20) were mostly male(85%), aged 64 � 4 years old. The pre-senting symptom was AMI in 2 pa-tients (10%) and unstable angina in therest. Fifteen patients (75%) had totallyoccluded SVGs. The median age of clotswas 6 days (range, 0 to 100 days). Theultrasound thrombolysis device has a1.6-mm-long tip and fits into a 7F guid-ing catheter over a 0.014-in guidewirein a “rapid-exchange” system. CUT (41kHz, 18 W, �6 minutes) led to devicesuccess in 14 (70%) of the patients andresidual stenosis of 65 � 28%. Proce-dural success was obtained in 13 (65%)of the patients, with a final residualstenosis of 5 � 8%. There was a low

rate of device-related adverse events: 1patient (5%) had a non-Q-wave myocar-dial infarction, and distal embolizationwas noted in 1 patient (5%). AdjunctPTCA or stenting was used in all pa-tients. There were no serious adverseevents during hospitalization. Conclu-sions: Ultrasound thrombolysis inthrombus-rich lesions in SVGs offers avery promising therapeutic option.AUTHORS’ ABSTRACT

Embolization

Expanded Indications for Ultra-sound-guided Thrombin Injectionof Pseudoaneurysms Steven S.Kang, Nicos Labropoulos, M. AshrafMansour, et al. J Vasc Surg 2000;31:289–298. (S.S.K., Loyola UniversityMedical Center, Department of Sur-gery, 2160 S. First Ave., Maywood, IL60153)● Purpose: We previously reported pre-liminary data on a new procedure thatwe developed for the treatment of femo-ral pseudoaneurysms after catheteriza-tion. This study presents our currentresults of percutaneous ultrasound-guided thrombin injection for treatingpseudoaneurysms that arise from vari-ous locations and causes. Methods: Be-tween February 1996 and May 1999,we performed thrombin injection of 83pseudoaneurysms in 82 patients. Therewere 74 femoral pseudoaneurysms: 60from cardiac catheterization (36 inter-ventional), seven from peripheral arte-riography (four interventional), fivefrom intra-aortic balloon pumps, andtwo from dialysis catheters. There werenine other pseudoaneurysms: five bra-chial (two cardiac catheterization, twogunshot wounds, one after removal ofan infected arteriovenous graft), onesubclavian (central venous catheter in-sertion), one radial (arterial line), andone distal superficial femoral and oneposterior tibial (both after blunt trau-ma). Twenty-nine pseudo-aneurysmswere injected while on therapeutic anti-coagulation. Patients underwent repeatultrasound examination within 5 daysand after 4 weeks. Results: Eighty-twoof 83 pseudoaneurysms had initial suc-cessful treatment by this technique,including 28 of 29 in patients who wereundergoing anticoagulation therapy.The only complication was thrombosisof a distal brachial artery, which re-solved spontaneously. There were earlyrecurrences in seven patients: four pa-tients underwent successful reinjection;reinjection failed in two patients, whounderwent surgical repair; and one pa-

tient had spontaneous thrombosis onfollow-up. After 4 weeks, ultrasoundexaminations were completely normalor showed some residual hematoma,and there were no recurrent pseudoan-eurysms. Conclusion: Ultrasound-guided thrombin injection of pseudoan-eurysms has excellent results, whichsupport its widespread use as the pri-mary treatment for this common prob-lem.AUTHORS’ ABSTRACT

Restenosis

Late Coronary Occlusion AfterIntracoronary BrachytherapyMarco A. Costa, Manel Sabate, Wim Jvan der Giessen, et al. Circulation1999;100:789–792. (Patrick W. Ser-ruys, Head of the Department of In-terventional Cardiology, UniversityHospital Dijkzigt-ThoraxcenterBd148, Dr. Molewaterplein.40–3015GD Rotterdam, The Netherlands)● Background: Intracoronary brachy-therapy appears to be a promising tech-nology to prevent restenosis. Presently,limited data are available regarding thelate safety of this therapeutic modality.The aim of the study was to determinethe incidence of late (�1 month) throm-bosis after PTCA and radiotherapy.Methods and Results: From April 1997to March 1999, we successfully treated108 patients with PTCA followed byintracoronary �-radiation. Ninety-onepatients have completed at least 2months of clinical follow-up. Of thesepatients, 6.6% (6 patients) presentedwith sudden thrombotic events con-firmed by angiography 2 to 15 monthsafter intervention (2 balloon angio-plasty and 4 stent). Some factors (over-lapping stents, unhealed dissection)may have triggered the thrombosis pro-cess, but the timing of the event is ex-tremely unusual. Therefore, the effectof radiation on delaying the healingprocess and maintaining a thrombo-genic coronary surface is proposed asthe most plausible mechanism to ex-plain such late events. Conclusions:Late and sudden thrombosis afterPTCA followed by intracoronary radio-therapy is a new phenomenon in inter-ventional cardiology.AUTHORS’ ABSTRACT

Effects of Intracoronary �-Radia-tion Therapy After Coronary An-gioplasty: an Intravascular Ultra-sound Study David Meerkin,Jean-Claude Tardif, Ian R. Crocker,et al. Circulation 1999;99:1660–1665.

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(Raoul Bonan, Montreal Heart Insti-tute, 5000 Belanger St., Montreal,Quebec, Canada H1T 1C8)● Background: Endovascular radiationis emerging as a potential solution forthe prevention and treatment of reste-nosis. Its effects on the morphology ofunstented vessels cannot be determinedby angiography and therefore requirethe use of intravascular ultrasound.Methods and Results: Through a 5Fnoncentered catheter for delivery of a90Sr/Y source train, 12, 14, or 16 Gy at2 mm was delivered to native coronaryarteries after successful balloon angio-plasty in 30 patients. Four patients re-quired stent deployment in the firstweek. Quantitative coronary angiogra-phy and IVUS were performed duringthe initial procedure and at 6-monthfollow-up. Binary angiographic resteno-sis was present in 3 of 30 patients, withtarget lesion and vessel revasculariza-tion performed in 3 and 5 patients, re-spectively. Angiographic late loss was�0.02 � 0.60 mm, with a �0.09 � 0.46loss index. IVUS demonstrated no sig-nificant reduction in lumen area (from5.69 � 1.72 mm2 after treatment to6.04 � 2.63 mm2 at follow-up), with nosignificant change in external elasticmembrane area (13.71 � 4.54 to14.22 � 4.71 mm2) over the 6-monthfollow-up. Wall area was 8.01 � 3.85mm2 after radiation therapy and8.19 � 3.44 mm2 at follow-up (P � NS).No significant differences were notedbetween the different dose groups. Con-clusions: �-Radiation therapy resultedin a low restenosis rate with negligiblelate loss by angiography. By IVUS,�-radiation was shown to inhibit neoin-tima formation, with no reduction oftotal vessel area at 6-month follow-up.AUTHORS’ ABSTRACT

Individual Kidney Function inAtherosclerotic Nephropathy IsNot Related to the Presence ofRenal Artery Stenosis Christo-pher K.T. Farmer, Gary J.R. Cook,Glen M. Blake, et al. Nephrol DialTransplant 1999;14:2880–2884. (J. E.Scoble, Renal Unit, Guy’s Hospital,St. Thomas’ Street, London Southern9RT, UK)

● Background: Atherosclerotic reno-vascular disease is increasingly recog-nized as an important cause of renalfailure in patients over 60 years of agebut the processes leading to renal dys-function have not been defined. Wehave examined the relationship be-tween renal artery stenosis and individ-ual renal function in patients with ath-erosclerotic renal artery stenosis. Meth-

ods: In this prospective descriptivestudy over a 25-month period, we ex-amined the relationship between thepresence of renal artery stenosis andsingle kidney glomerular filtration rate(SKGFR). SKGFR was measured usinga novel method of synchronous 51Chro-mium ethylenediamine tetraacetic acidglomerular filtration rate (51CrEDTA-GFR) and 99mTechnetium dimercapto-succinic acid (99mTcDMSA) scintigra-phy. We studied 79 patients with amean age of 68.9 years (25.2–88.2), 44males and 35 females. The mean age ofthe males was 70 years (60–80) andfemales 67 years (25.2–88.2). Results:We found that the precision of theSKGFR was 2 mL/min. For paired kid-neys we found: (i) no significant differ-ence between kidneys with stenosis(17.3 mL/min) compared to those with-out stenosis (13.61 mL/min) (P � 0.22);(ii) kidneys with occluded renal arterieshad significantly less function (2.6 mL/min) than those without occlusion (24.5mL/min) (P � 0.05). When degree ofrenal arteries stenosis was correlatedwith SKGFR there was a reductionwith an increasing degree of stenosis(�30% 27 mL/min, 30%–60% 17.7 mL/min, �60% stenosis 15 ml/min, P �0.016). Conclusions: These data demon-strate that SKGFR provides a repro-ducible measure of individual kidneyfunction. There was a similar impair-ment of function in paired kidneys withand without renal artery stenosis, butocclusion was associated with signifi-cant reduction in function compared tothe contralateral kidney. This suggeststhat there is a process causing renaldysfunction in patients with atheroscle-rotic disease independent of renal ar-tery narrowing.AUTHORS’ ABSTRACT

VASCULAR—VENOUSThromboembolic Disease

Physicians’ Attitudes toward Mis-diagnosis of Pulmonary Embo-lism: Utility Analysis Max P.Rosen, Daniel Z. Sands, Karen M.Kuntz. Acad Radiol 2000;7:14–20.(M.P.R., the Department of Radiology,Beth Israel Deaconess Medical Centerand Harvard Medical School, 300Brookline Ave., Boston, MA 02215)

● Rationale and Objectives: The pur-pose of this study was to measure phy-sicians’ utilities for outcomes after ven-tilation-perfusion lung scanning and toexplore physicians’ attitudes towards

misdiagnosis and the treatment of pa-tients suspected of having pulmonaryembolism (PE) in a quantitative man-ner by using a utility analysis. Materi-als and Methods: Before ordering lungscanning for suspected PE, physiciansrated five possible outcomes on a scaleof 0–100 by using a computer order-entry system. These responses wererescaled and transformed to a utilitymeasure by using the Torrance trans-formation. Results: The mean utility forthe potential outcomes after 341 lungscans were (a) no PE and no treatment(true-negative, 93 � 22 �mean � stan-dard deviation�), (b) PE with appropri-ate treatment (true-positive, 84�24), (c)no PE but patient received treatment(false-positive, 54 � 32), (d) PE but pa-tient did not receive treatment (false-negative, 14 � 23), and (e) death dur-ing pulmonary angiography (2 � 11).After lung scanning for acute PE, phy-sicians placed greatest value on exclud-ing the diagnosis (true-negative). Pro-viding unnecessary treatment (false-positive) was valued in the midrange ofutilities. The value of missing PE(false-negative) was rated almost equalto that of dying during pulmonary an-giography. Conclusion: Physicians con-sider providing treatment for PE with-out objective confirmation of an embo-lus to be preferable to missing a case ofPE.AUTHORS’ ABSTRACT

Pulmonary Embolism: One-YearFollow-Up With Echocardiogra-phy Doppler and Five-Year Sur-vival Analysis Ary Ribeiro, PerLindmarker, Hans Johnsson, et al.Circulation 1999;99:1325–1330. (A.R.,Department of Clinical Physiology,Thoracic Clinics, Karolinska Hospital,171 76 Stockholm, Sweden)● Background: The long-term prognosisfor patients with pulmonary embolism(PE) is dependent on the underlyingdisease, degree of pulmonary hyperten-sion (PH), and degree of right ventricu-lar (RV) dysfunction. A precise descrip-tion of the time course of pulmonaryartery pressure (PAsP)/RV function istherefore of importance for the earlyidentification of persistent PH/RV dys-function in patients treated for acutePE. Other objectives were to identifyvariables associated with persistentPH/RV dysfunction and to analyze the5-year survival rate for patients alive 1month after inclusion. Methods andResults: Echocardiography Doppler wasperformed in 78 patients with acute PEat the time of diagnosis and repeatedlyduring the next year. A 5-year survival

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analysis was made. The PAsP de-creased exponentially until the begin-ning of a stable phase, which was �38days. The recovery of RV function oc-curred during the same time period.Risk factors for persistent PH/RV dys-function and the 5-year mortality ratewere analyzed using multiple logisticregression models. A PAsP of �50 mmHg at the time of diagnosis of acute PEwas associated with persistent PH after1 year. The 5-year mortality rate wasassociated with underlying disease.Only patients with persistent PH in thestable phase required pulmonarythromboendarterectomy within 5 years.Conclusions: An echocardiographyDoppler investigation performed 6weeks after diagnosis of acute PE canidentify patients with persistent PH/RVdysfunction and may be of value inplanning the follow-up and care ofthese patients.AUTHORS’ ABSTRACT

Dialysis Access

New Ultrasound Approaches toDialysis Access MonitoringMarla Paun, Kirk Beach, Suhail Ah-mad, et al. Am J Kidney Dis 2000;35:477–481. (M.P., University of Wash-ington School of Medicine, Depart-ment of Surgery, Box 356410, Seattle,WA 98195-6410)

● The failure of dialysis access is afrequent source of morbidity and hospi-talization. Traditional methods of graftsurveillance include: (i) clinical exami-nation, (ii) venous line pressure mea-surements during dialysis, (iii) urea ortracer recirculation measurement, (iv)continuous wave (CW) Doppler meth-ods, (v) duplex ultrasonography, and(vi) radiograph angiography. All thesemethods require special training and/orlaboratory tests. The purpose of thisstudy was to test a simple continuous-wave Doppler method that could be ap-plied to measure the flow rate in dialy-sis access every time the patient under-goes dialysis. Twenty dialysis patients,15 with polytetrafluorethylene graftsand 5 with arteriovenous fistulae, werestudied. Two hundred fifty-three exami-nations were performed over an8-month period. Doppler waveforms ofthe access flow were obtained with thepump on, with the pump off, and withthe pump on again. Systolic and dia-stolic Doppler frequency measurementswere made, and the pump-on andpump-off measurements were com-pared. In an access functioning nor-mally, the Doppler frequencies are

higher with the pump off than with thepump on. In 22% of the cases, therewere abnormal findings in which theDoppler frequencies were lower withthe pump off than with the pump on.This occurs if the needles are incor-rectly placed, suggesting that recircula-tion is occurring. Recirculation also oc-curs if there is stenosis of the access.Examining the hemodialysis accessduring each dialysis session with aninexpensive directional Doppler mayidentify a significant stenosis and im-prove the efficiency of dialysis by de-tecting those patients in whom the ar-terial and venous needles are reversed.AUTHORS’ ABSTRACT

Changes in the practice of angio-access surgery: Impact of dialysisoutcome and quality initiativerecommendations Enrico Ascher,Prasad Gade, Anil Hingorani, et al. JVasc Surg 2000;31:84–92. (E.A., Di-rector, Division of Vascular Surgery,Maimonides Medical Center, 4802Tenth Ave, Brooklyn, NY 11219)● Purpose: Recommendations recentlypublished by the National KidneyFoundation-Dialysis Outcome andQuality Initiative (DOQI) included anappeal for increased use of native arte-riovenous fistulas (NAVFs) to improveoverall patency and contain angioaccesscosts. We evaluated the impact of theDOQI recommendations on angioaccesssurgery and its outcome at our institu-tion. Methods: From June 1996 to April1999, 483 angioaccess procedures wereperformed on 247 patients. There were133 men and 114 women, with an aver-age age ranging from 28 to 95 years(mean age, 69 � 0.59 years). Risk fac-tors included smoking in 143 patients(58%), diabetes mellitus in 135 patients(55%), hypertension in 150 patients(61%), and coronary artery disease in98 patients (40%). The patients weredivided in two groups. Group I (pre-DOQI) included patients who had an-gioaccess procedures between June1996 and November 1997, and group II(post-DOQI) included patients who hadangioaccess procedures between De-cember 1997 and April 1999. The typesof procedures performed included place-ment of arteriovenous grafts (AVGs) in122 patients (25%), creation of NAVFsin 99 patients (20%), revision of AVGsin 123 patients (25%), and temporaryaccess procedures in 135 patients(28%). Forty-seven of the NAVF proce-dures were radial-cephalic fistulas(47%), 22 were brachial-cephalic fistu-las (23%), and 30 were brachial-basilicfistulas (30%). Patients underwent se-

rial ultrasonography scanning andphysical examinations; the mean fol-low-up period was 9 months. Choice ofangioaccess procedures and patencyrates before and after implementationof the DOQI recommendations werecompared. Results: There was a signifi-cant increase in the use of NAVFs afterimplementing DOQI recommendations(5% vs 68%, P � .001). The 1-year pri-mary patency rate of AVGs was lessthan that of arteriovenous fistulas (54%vs 85%, P � .001). During the studyperiod, the percentage of AVGs placedat our institution that required revision(59%; 72 of 123) was higher than thatof NAVFs that required revision (4%; 4of 99; P �.001). There was no signifi-cant difference in the maturation ratesof radial-cephalic fistulas (75%), brachi-al-cephalic fistulas (91%), and brachial-basilic fistulas (87%). Conclusion: Byadopting the DOQI recommendations,we used NAVFs more often. This re-sulted in superior patency rates, com-pared with synthetic grafts. The liberaluse of preoperative duplex venous map-ping further increased NAVF use, sur-passing the DOQI expectations for pri-mary arteriovenous fistulas. Addition-ally, fewer revisions were required.AUTHORS’ ABSTRACT

Treatment of Failed Native Arte-riovenous Fistulae for Hemodialy-sis by Interventional RadiologyLuc Turmel-Rodrigues, Josette Pen-gloan, Herve Rodrigue, et al. Kidney Int2000;57:1124–1140.● Background: We studied the feasibil-ity, technical problems, safety, and ef-fectiveness of percutaneous declottingof thrombosed native arteriovenous fis-tulae for hemodialysis. Methods: Be-tween 1992 and 1998, 98 declottingprocedures were performed in 73 con-secutive upper limb native fistulae(forearm 56 and upper arm 17), and162 procedures were performed in 78prosthetic grafts using manual cathe-ter-directed thromboaspiration, with orwithout previous urokinase infusion.Detection of restenosis by clinical sur-veillance led to redilation or stentplacement. Rethromboses in four fore-arm and six upper arm fistulae weretreated by 20 further declottings by as-piration. Results: The initial successwas 93% in the forearm and 76% in theupper arm (99% in grafts). The compli-cations included one pulmonary embo-lism, one acute pseudoaneurysm, andone blood depletion requiring transfu-sion. Primary patency rates at one yearwere 49% in the forearm and 9% in theupper arm (14% in grafts). Secondary

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patency rates were 81 and 50% at oneyear, respectively (83% in grafts). Rein-terventions were necessary every 19.6months in the forearm and every 5.7months in the upper arm (every 6.4months in grafts. P � 0.05). Stentswere placed in 11% of forearm fistulaeand in 41% of upper arm fistulae (45%of grafts) for treatment of acute rupture(5 out of 19), stenosis recoil (6 out of19), and early (�6 months) recurringstenosis (8 out of 19). Conclusions: Thepercutaneous declotting of forearm fis-tulae by manual catheter-directedthromboaspiration was effective inmore than 90% of cases and yielded50% primary and 80% secondary pa-tency rates at one year. The resultswere poorer in upper arm fistulae. Theneed for maintenance interventionswas three times smaller in forearm fis-tulae than in upper arm fistulae andgrafts.AUTHORS’ ABSTRACT

Percutaneous Treatment ofThrombosed Primary Arterio-venous Hemodialysis Access Fis-tulae Patrick Haage, Dierk Vor-werk, Joachim E. Wildberger, et al.Kidney Int 2000;58:1169–1175.

● Background: We reviewed the effi-cacy of percutaneous intervention inacute thrombotic occlusion of nativearteriovenous (AV) fistulae for hemodi-alysis. Methods: Eighty-one percutane-ous procedures were performed in 54patients presenting with a clotted na-tive dialysis fistula. There were 63cases of a long-segment thrombosis ofthe fistula. In 20 cases, a small throm-bus usually caused by an underlyingsevere stenosis was observed. A proxi-mal arterial occlusion was seen in onecase. Treatment depended on clot sizeand included balloon dilation (n � 20),mechanical thrombectomy with variousdevices (n � 58), as well as pharmaco-mechanical thrombolysis (n � 3). Re-sults: Full restoration of flow was es-tablished in 72 cases (88.9%). Earlyreobstruction within 14 days occurredin eight cases (11.1%). Primary patencyrates after a 1-, 3-, 6-, and 12-monthperiods were 74, 63, 52, and 27%, re-spectively. Overall fistula patency was75% after 3 months, 65% after 6

months, 51% after 12 months, and 22%after 24 months. Conclusions: Acutethrombotic occlusion of native AV fistu-lae is a major complication of hemodial-ysis. The results of treatment are be-lieved to be less successful than throm-bosis treatment in synthetic grafts. Ourresults, however, indicate the efficacy ofpercutaneous treatment in native fistu-lae, and demonstrate comparable tech-nical results and patency rates.AUTHORS’ ABSTRACT

CONTRAST

Renal Angiography using CarbonDioxide R. C. Beese, N. R. Bees,A. M. Belli. Br J Radiol 2000;73:3–6.(A.M.B., Department of Radiology, St.George’s Hospital, Blackshaw Road,London SW17 0QT, UK)

● The many advantages of carbondioxide (CO2) angiography in the inves-tigation of renal arterial disease includean absence of both nephrotoxicity andallergic reactions. An automated deliv-ery system facilitates injection of CO2whilst ensuring that there is no con-tamination of the injection with air. Wereport our initial experience using aprospective study of this delivery sys-tem in 47 patients referred for renalangiography, and assess diagnostic im-age quality and adverse reactions toCO2 angiography using the automateddelivery system. The majority (37/47;79%) of angiograms were of diagnosticquality and there were no significantadverse reactions in response to theCO2 contrast agent.AUTHORS’ ABSTRACT

MISCELLANEOUS

Skin Sparing in InterventionalRadiology: the Effect of CopperFiltration R. Nicholson, F. Tuffee,M. C. Uthappa. Br J Radiol 2000;73:36–42. (R.N., Department of Radiol-ogy, St. Mary’s Hospital, PraedStreet, London W2 1NY, UK)

● Complex and lengthy interven-tional radiological techniques haveresulted in a number of patients de-veloping skin reactions in recentyears. To safeguard against these sideeffects, we have investigated the de-gree to which entrance skin dose canbe reduced by inserting 0.18 mm and0.35 mm copper filtration in the inci-dent beam. The potential reductionwas measured on a 22 cm waterphantom for each of eight models of afluoroscopy unit. Using the catheterlaboratory fluoroscopy unit on whichradiofrequency ablations are routinelyperformed, we assessed the relativeeffectiveness of adding filtration andincreasing the kV:mA ratio. Imagequality was subjectively assessed fordiagnostic and therapeutic acceptabil-ity in two groups of 10 patients un-dergoing radiofrequency ablations,pacemaker insertions or electrophysi-ology studies. One of the groups wasscreened with 0.35 mm copper filtra-tion in place and the other groupacted as the control. Maximum pa-tient skin dose proved difficult tomeasure directly because of the un-predictable dose pattern. This patternwas studied in four patients using afilm method in conjunction with ther-moluminescent dose meters. Copperfiltration 0.35 mm thick inserted inthe beams of the eight fluoroscopyunits produced a mean reduction inentrance dose to the phantom of 58%with a mean increase in tube loadingof 29%. At 100 kV the increased load-ing on the X-ray tube was equivalentto increasing the anteroposterior sep-aration of the patient by 2 cm. Mea-surements on the catheter laboratoryunit showed that the tube voltagewould need to be raised above thenormal diagnostic range to obtain anequivalent entrance dose reductionwithout the filter. The blackening offilms under the patients showed com-plex patterns, but the estimated skindoses were consistent with those pre-dicted by the phantom experiments.All six cardiologists considered thereto be insignificant detriment to imagequality in the procedures investi-gated.AUTHORS’ ABSTRACT

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