Stent Implantation of the Arterial Duct in Newborns with a Truly

C 2010,Wiley Periodicals,Inc.DOI:10.1111/j.1540-8183.2010.00576.xStent Implantation of the Arterial Duct in Newborns with a TrulyDuct-Dependent Pulmonary Circulation:A Single-Center Experiencewith Emphasis on Aspects of the Interventional TechniqueDIETMAR SCHRANZ,M.D.,INA MICHEL-BEHNKE,M.D.,RAJKA HEYER,M.D.,MELANIE VOGEL,M.D.,J¨URGEN BAUER,M.D.,KLAUS V ALESKE,M.D.,HAKAN AKINT¨URK,M.D., and CHRISTIAN JUX,M.D.From the Department of Paediatric Cardiology and Cardiac Surgery,Pediatric Heart Center,Justus-Liebig-University Giessen,GermanyIntroduction:Ductal stenting for pulmonary blood supply in newborns with cyanotic congenital heart disease(CHD)might be a low risk and safe alternative to the surgical aorto-to-pulmonary artery(AP)shunt in dual-sourcelung perfusion.Ductal stenting in truly duct-dependent pulmonary circulation has not been evaluated.Methods:Prospective interventional and clinical follow-up trial.Ductal stenting based on variable accesssites,a2-wire technique when crossing a tortuous ductus,and use of premounted coronary stents.Primaryoutcome measures were procedural success and complication rates presented as early and mid-term results.Results:From2003–2009,58duct-dependent newborns underwent ductal stenting;27of them were truly ductdependent,20had pulmonary atresia(PA)/ventricular septum defect or complex CHD,4had PA/intact ventricularseptum,2had PA with Ebstein anomaly,and1had PA with tricuspid atresia.Ductal stenting was performedwithout procedure-related mortality;3of27required an acute surgical AP-shunt(stent migration in1,acute ductobstruction in2).During mid-term follow-up,4of24needed an AP-shunt and two others stent redilation.Threepatients died prior to follow-up surgery(1unexpectedly at home and2due to syndromatic disease).Fifteen patientsreceived staged univentricular palliation,8had a biventricular repair,and1is awaiting follow-up operation.Conclusion:Ductal stenting is a feasible,safe,and effective palliation in newborns with truly duct-dependentpulmonary circulation irrespective of duct morphology.Vasucular access from various locations is important fortechnical success rate.Ductal stenting is a minimally invasive procedure to achieve adequate pulmonary arterygrowth for subsequent palliative or corrective surgery.(J Interven Cardiol2010;23:581–588)IntroductionDuctal stenting for pulmonary blood supply in new-borns with cyanotic congenital heart disease(CHD)is utilized alternatively to a surgical aorto-to-pulmonary artery(AP)shunt,particularly in low-income coun-tries,such as Malaysia1and India.2The objective of stenting the patent ductus arteriosus(PDA)is to avoid or delay surgical AP-shunts in neonates and young in-Address for reprints:Dietmar Schranz,M.D.,Pediatric Heart Cen-ter,Justus-Liebig University,Feulgenstrasse12,35385Giessen, German.Fax:496419943469;e-mail:Dietmar.Schranz@paediat. med.uni-giessen.de fants.Stent implantation of the PDA for restrictive, dual-sourced pulmonary bloodflow is an accepted ap-proach with relative low risk.3–9Controversy exists with respect to ductal stenting in neonates with a truly duct-dependent pulmonary circulation,where the pro-cedure is complicated by the PDA morphology with its vertical position mostly originating from the inner curve of the aortic arch,often associated with duc-tal tortuosity.5,7,9,10Based on our institutional expe-rience of percutaneous ductal stenting in more than 200newborns with various forms of a duct-dependent circulation,11the aims of this prospective study were to evaluate the feasibility and the technical aspects, and to report the results of primary ductal stenting inSCHRANZ,ET AL.newborns with cyanotic CHD and a truly duct-dependent pulmonary circulation.MethodsThis is a prospective interventional and clinical follow-up study at a tertiary referral center.The pri-mary outcome measures were procedural success and complication rates presented as early and mid-term re-sults.The study was undertaken under the guidelines of the hospital investigation review board.Parental writ-ten informed consent for the procedure and agreement on the management with the cardiac surgeon were al-ways obtained.4Patients.Between January2003and December 2009,stent-implantation of the PDA was performed in58newborns with cyanotic CHD as an alternative to surgical palliation on an intention-to-treat basis;an-alyzed were27newborns with a truly duct-dependent pulmonary circulation.Echocardiographic evaluation was used to select suitable patients for ductal stenting by confirming the cardiac diagnosis and PDA anatomy and morphology.In four patients,additional cardiac magnetic resonance imaging was performed to con-firm the ductal morphology prior to delineating the anatomy angiographically during cardiac catheteriza-tion.Based on PDA morphology or origin,there were no exclusion criteria for ductal stenting.Only one pa-tient with azygos continuation of the inferior vena cava was excluded,an antegrade approach was impossible and the ductal angle from the aorta was judged as in-appropriate for a retrograde approach.Table1sum-marizes the clinical data of the27patients that were included in the study.Based on previous experiences4 PDA stenting was used as an alternative to the sur-gical AP-shunt,bridging the patient toward an early cavo-pulmonary anastomosis in univentricular physi-ology or a biventricular repair where possible.All pa-tients had pulmonary valve atresia(PA)and received postnatal prostaglandin E1(PGE1)as a continuous in-fusion(5–10ng/kg per min).PA was either associ-ated with a ventricular septum defect or complex CHD (n=21)or with an intact ventricular septum in which catheter valvotomy was not indicated(n=4).Two other patients had Ebstein anomaly with PA,in which transcatheter valve opening was also not indicated at-tributed to the risk of pulmonary to right ventricular run off.In most patients,the PDA was arising from the inner curve of the aortic arch with a tortuous course, either left or right sided.Cardiac Catheterization and Stent Placement. Cardiac catheterization was performed under general anesthesia in two patients and in25under conscious sedation utilizing diazepam and ketamine in repetitive single dosages of0.2–0.5mg/kg and local anesthe-sia as described elsewhere in detail.4,11In7patients with wide-open PDAs but a short ductal length PGE1 was discontinued2–4hours prior to the procedure with the aim to reduce the ductal diameter to facili-tate stent implantation and achievefirm adherence to the ductus wall.However,in tortuous or stenotic PDAs PGE1infusion was stopped only after successful stent placement.Based on the origin and shape of the PDA, vascular access was attempted from the femoral vein, femoral artery,and right or left axillary artery favoring the straightest course toward the ductal take off from the aorta.The PDA morphology,its size,and length were assessed angiographically,if necessary in multi-ple projections.When the decision for ductal stenting was confirmed,a premounted coronary stent(mono-rail system)was implanted through a4Fr45-cm long guiding sheath(Cook,Bjaeverskov,Denmark)placed through the right or single ventricle in the anteriorly positioned ascending aortic arch if venous access was chosen.In the case of femoral artery access,a25-cm 4Fr sheath(Terumo Corporation,Tokyo,Japan)was used,and in the case of an axillary artery access a7-cm 4Fr sheath(Terumo),was used.In all patients,the ves-sel access was obtained by percutaneous puncture,with placement of a2Fr arterial cannula(Vygon,Aachen, Germany)prior to exchange for the4F introducer.An-giography of the aortic arch in anterior-posterior and 90◦lateral projection was performed to get an anatomi-cal overview of the aortic arch and PDA position.Tech-nical details of the interventional procedure have been previously described11–13and are demonstrated in Fig-ures1A–D.Afloppy of0.014-inch coronary guidewire (Balance Middleweight,Abbott,IL,USA)was atfirst advanced through a4Fr right Judkins or4Fr Cobra catheter and maneuvered carefully through the PDA in all patients,and placed distally in the right or left pulmonary artery or within the pulmonary trunk,if ex-isting.For stent delivery,a0.014-inch coronary extra support guidewire(S’port,Abbott,IL,USA)was used. The stiffer wire was advanced additionally besides the primarily placed super softfloppy wire(Fig.1B). The double-wire technique facilitated the placement of the relative stiff support wire and avoided ductusSTENT IMPLANTATION OF THE ARTERIAL DUCT IN NEWBORNSTable1.Data of Patients and MethodsAge Early Catheter Patient(Days)at Weight Stent Used Reinterventions No Stenting(kg)Diagnoses Width/Length(mm)(5<Days) 15 2.7PA+UVH,upside-down stomach Tsunami4×15Redilation 23 2.9PA+VSD Tsunami4×15None35 2.9PA+VSD,HRH,rAOA Nir-flex4×16,4×12None45 3.6PA,Ebstein anomaly Nir-flex4×19None53 3.5PA+VSD,DORV Nir-flex4×12None68 3.5PA+IVS,HRV,coronaryfistulae Tsunami4×10Redilation 79 3.1PA,dextrocardia,UVH,TGA Tsunami4×15None 811 2.7PA+IVS,HRH,ASD Driver4×9None96 3.2PA+VSD,ccTGA Driver4×15None 105 2.2PA+VSD,Alagille,biliary atresia Driver4×9None 1116 3.7PA,TGA,UVH Driver4×24,4×15None 128 3.8PA+IVS,HRH,coronaryfistulae Driver4×24,4×15None 135 2.3PA+VSD,catch22Driver4×18None 144 5.4PA,TGA,UVH,situs inversus Driver4×15None 153 3.3PA+VSD,hypoplastic PA’s Driver4×18,4×12None 1611 3.1PA,Ebstein anomaly Driver4×154×24None 172 5.2PA+VSD,rAOA,LPA-S Driver4×18,4×12None 1813 3.4PA,UVH,dextrocardia,Azygos-C Driver4×15,4×12None 193 2.5TA IIa(TGA+PA+VSD)Driver4×18,4×9None 2031 5.5PA+VSD Driver4×18None 216 2.5PA+IVS,HRH,ASD Driver4×12,4×15Driver4×15 223 3.5Situs inversus,complex UVH+PA Driver4×18None 2327 3.2V ACTERL-S,PA+AS,EA-IIIc Driver4×18None 2416 3.1Trisomie21,PA+VSD,rAOA Liberte4×20,Driver4×18None 259 3.2PA+IVS,HRHS,coronayfistulae Driver4×18None 267 3.2Dextrocardia,PA,MA,UVH Driver4×18,4×9None 2725 2.1Premature,heterotaxy,PA+UVH,Driver4×24,4×12,4×18NoneTAPVD,common atriumAOA=aortic arch;A VSD=atrial-ventricular septal defect;Azygos-C=continuity;ccTGA=congenital corrected transposition of the great arteries;DORV=double outlet right ventricle;EA=esophageal atresia;HRHS=hypoplastic right heart syndrome;IVS=intact ventricular septum;LPA-S=left pulmonary artery stenosis;r=right;MA=mitral valve atresia;PA=pulmonary atresia;TA=tricuspid atresia; TAPVD=total anomalous pulmonary venous drainage;UVH=univentricular heart;VSD=ventricular septal defect.perforation or creation of a false lumen.The soft wire was removed when the stiffer guidewire reached a sta-ble position useful for PDA stenting.The stronger sup-port wire straightens the PDA and necessitates reevalu-ation of the length of the PDA to calculate the required stent length,particularly if it were previously tortuous. Small amounts of contrast medium were administered by hand injections through the sidearm of the hemostat ventilfixed at the guiding or Judkins/Cobra catheter. To prove catheter access through the tortuous PDA or in case of predilation,a3-mm balloon catheter(Apex, Boston Scientific,Marlboro,MA,USA)was advanced in patients with a minimum ductal diameter of<2mm. Premounted coronary stents(width=4mm),but dif-ferent lengths(9,12,15,18,24mm Driver[Medtronic, Louisville,Colorado,USA]),Tsunami(Terumo),or 20-mm Libert´e(Boston Scientific)were used in all patients.Ductal stenting with a monorail premounted coronary stent was always performed with four hands; while one hand wasfixing the delivery sheath within the aorta,the stent was advanced through the long sheath and PDA in a“push-pull technique”by con-tinuously observing the position of the guidewire.If required,contrast injection was performed through the delivery sheath to adjust the premounted stent po-sition immediately before its deployment.Following balloon inflation,satisfactory stent placement was also assessed by repeated angiographies.In some patients, ductal lengths necessitated the use of2or3stents (Figs.1C and D,2A–D).The additional stents were delivered by telescopic placement tailoring the over-all stent length to the individual PDA anatomy in theSCHRANZ,ETAL.Figure 1.(A-D)Ductal stenting as a live case intervention (7th Workshop IPC&ISHAC Joint Meeting Milan 2009).(A)Angiography performed by hand injec-tion of contrast medium through a right Jud-kins catheter,which is advanced through a 4Fr long Cook sheath positioned in the as-cending aorta.Pulmonary arteries are sup-plied by a vertical,tortuous duct,which arises from the inner curve of a right-sided aortic arch next to the left-sided head-neck vessels.(B)The exact insertion of the duct at the pulmonary artery bifurcation by placement of 2floppy guidewires to both,the left and right pulmonary artery,and by an additional contrast medium application through the Judkins-catheter advanced al-most to the middle of the duct.(C)Place-ment of a second stent to cover the duct in total.(D)Angiogram through the Cook sheath demonstrates the final result of duct stenting in this newborn with truly duct-dependent pulmonary blood flow.same or in a second procedure.Heparin (100U/kg)was given at vessel entry and continued for 24hours at a dose of 300U/kg/day without further adjusting the dosage.Aspirin was not given routinely;patients with 2or 3stents in place were treated with antiplatelet drugs,either with aspirin (2–3mg/kg per day)or,since 2006,with clopidogrel (0.2mg/kg per day)(Picolo study).14Follow-up Protocol.After stent implantation,pa-tients were assessed by continuous measurement of oxygen saturation (pulse-oximetry),repetitive blood pressure measurements,and echo-and electrocardio-graphy.Repeat cardiac catheterization was performed when a significant drop in oxygen saturation suggested restenosis or prior to planned palliative or correc-tive surgery.Redilation of the stents was performed with a balloon equal in size to the one used during the initial stent placement.Growth of the pulmonary vasculature was assessed cine-angiographically using the McGoon index.Outcome measures were a suc-cessful palliative or corrective surgery and seque-lae after ductal stenting.Results are expressed as medians or means,and range (minimum to max-imum values)and standard deviation (SD)of the mean.ResultsPatients.The demographic data are listed in Table 1.The patient’s median age was 6days (2–31)and the median weight was 3.2kg (2.1–5.5).On admission,all patients were treated with PGE1.The mean oxygen saturation was 85%(60–93,SD:7.4).Transthoracic echocardiogram showed a tortuous elon-gated PDA morphology arising anywhere from the in-ner curve of aortic arch in all patients with complex PA (n =21).The median PDA length was 17mm (9–28).The narrowest parts were at the pulmonary artery site or anywhere within the curved and tortuous course of the PDA;the median diameter measured 2.5mm (1–3).The aortic end was measured at a median of 4.5mm (3.0–6.5).Twenty-five patients were investigated un-der sedation;2neonates were intubated and ventilated for other noncardiac reasons.Cardiac and noncardiac anomalies are presented in Table 1.STENT IMPLANTATION OF THE ARTERIAL DUCT INNEWBORNSFigure 2.(A)The angiography of an extremely tortuous duct supplying the left and right pulmonary artery.A floppy guidewire is positioned in a left lower lobe artery.Angiography was performed by hand injection of contrast medium through a right Judkins catheter,which is advanced through a 4Fr long COOK sheath (arrow)positioned in the ascending aorta.On (B)placement of a first Driver stent (4×24mm,arrow)within the duct,directed to its pulmonary insertion,is shown in anterior-posterior projection.(C)Demonstrates telescopic stenting in lateral projection (arrows mark the 2stents).(D)Angiography of the final result is shown.Placement of 3stents (each marked by an arrow)in series shows a fully duct covering from its pulmonary insertion to aortic site;left and right pulmonary arteries are perfused by the stented duct despite a pulmonary coarctation (Pt 27).Procedural Complications.Acute stent migra-tion occurred in 1patient during removal of the deflated balloon (No.9).Acute hemodynamic deterio-ration occurred in 2patients during a second catheter-ization for acute reobstruction on the first day after the primary approach (No.18,25).One of these pa-tients deteriorated during the procedure and was suc-cessfully resuscitated by locally administered PGE1as bolus in addition to continuous PGE1-infusion prior to performing an AP-shunt.In the other patients,a sec-ond stent placement was attempted to cover a residual nonstented part of the PDA.He also deteriorated and needed continuous infusion of PGE1,catecholamines,and intermittent cardiac massage before going onto cardiac bypass and surgical AP-shunt application.Acute Follow-Up.Ductal stenting was achieved in all patients.No procedural deaths occurred.Mean fluo-roscopy time was 13.8minutes (4.8–37.2,SD:±8.1).Severe tortuosity of the PDA did not preclude trans-catheter stent implantation.Based on the origin and shape of the PDA,vascular access was gained from the femoral vein (n =10),femoral artery (n =12),right axillary (n =2),or left axillary artery (n =3).In 5pa-tients predilation of the narrowed PDA was necessary to achieve free passage of the stent.Two stents were required in 11patients and three in 1patient (Fig.2).A total of 39coronary stents were implanted in 27pa-tients during the first procedure (Table 1).In 2patients,an uncovered part of the PDA was observed immedi-ately after guidewire removal,when the stented duct shaped back to its natural course.After discontinuation of PGE1,the PDAs were diagnosed as patent,when there was no decrease in oxygenation,and sufficient left-to-right shunt through the stent was demonstrated on transthoracic echocardiography.Patients with in-creasing cyanosis suggesting reobstruction of the PDASCHRANZ,ET AL.(n=3)were treated with reintervention.Early reob-struction within thefirst5days after the interventional procedure was treated with balloon dilatation(n=2) or placement of a further stent(n=1)(Table1).In late obstruction(4/24;16.6%),a redilation of stents was performed only in cases where ductal patency was required for>1month until further surgery.Ductal tissue obstruction due to a partially nonstent-covered PDA was the main reason for immediate restenosis within thefirst5days.However,endoluminal tissue growth of various degrees without significant influ-ence on oxygenation was found accidentally at the time of the preoperative diagnostic cardiac catheterization, but not analyzed systematically.In2patients,in-stent tissue growth necessitated redilation and in1for place-ment of a second stent prior to surgery.Mid-term Follow-Up.The follow-up period ranged from2months to7years.The stents remained patent from1to243days(Table2).Reevaluation or interventions more than5days after the initial proce-dures were necessary in7of24patients(29%).Growth of the pulmonary arteries was proven in all patients. The median McGoon index at time of surgery was1.9 (1.6–2.2).The median body weight was3.2kg(2.1–5.5)at the time of intervention,with an increase to 5.3kg(3.5–8.5)at the time of palliative or corrective surgery.Fifteen patients with univentricular physiol-ogy received a bidirectional Glenn shunt(BCPC),1 patient died,and9completed total cavo-pulmonary connection.Corrective surgery was successful in eight patients,1is awaiting surgical repair.Seven patients received an AP-shunt,2of them underwent an addi-tional intervention for an obstructed shunt—stenting in one and a new shunt with left pulmonary artery (LPA)augmentation in the other.The4deaths were not associated to the catheter intervention:1infant with PA and intact ventricular septum died unexpect-edly at home(obstructed coronary arteries were found on autopsy);the second death was related to hepatic dysfunction in a patient with Alagille-syndrome;the third was related to respiratory failure due to lung hy-poplasia in a patient with V ACTERL-syndrome;and the fourth occurred after surgical repair of Ebstein anomaly.At the time of surgery,the PDA stents were removed or ligated and transected by the surgeon without any difficulty.Thrombus formation was not found,but there were various degrees of in-stent stenosis.The degree of ductal tissue in-growth showed neither correlation to the stent type nor to the(type of)antiplatelet medica-Table2.Follow-Up DataDurationof Stent SurgeryPatient Patency at Stent Follow-up Final No(days)Removal Surgery Outcome 140AP-shunt Glenn,TCPC Alive 212AP-shunt BVR Alive 393Glenn TCPC Alive 468Glenn Postsurgical Diedheart failure5158BVR Alive 6115Glenn TCPC Alive 7108AP-shunt Glenn,TCPC Alive 823Sudden death Died 91AP-shunt Glenn,TCPC Alive 1021Bile atresia Died 11116Glenn TCPC Alive 12243Glenn TCPC Alive 13110BVR Alive 1491Glenn TCPC,LPA/AliveRPA-Patch1575BVR Alive 16112Glenn TV-reconstruction,AliveVSD17142BVR Alive 182AP-shunt Glenn,TCPC Alive 19124Glenn Alive 2088BVR Alive 21125Glenn Alive 22111Glenn Alive 2348AP-shunt PA-Patch Diedaugmentation2490BVR Alive 251AP-shunt Glenn Alive 26120Glenn Alive 2791Awaiting Glenn Alive AP=aorto-pulmonary shunt;BVR=biventricular re-pair;Glenn=bidirectional cavo-pulmonary connection; E-AIIC=esophageal atresia withfistulae;PA=pulmonary artery; TCPC=total cavo-pulmonary connection;TV=tricuspid valve; VSD=ventricular septal defect.tion and was observed at various time-points of follow-up.DiscussionIn neonates with cyanotic CHD,adequate pul-monary blood supply is essential for survival.Hence, the surgical AP-shunt is still used as the treatment of first choice.15,16Considering advances in surgery for CHD and a trend toward early primary biventricular repair or univentricular palliation,a reliable and safeSTENT IMPLANTATION OF THE ARTERIAL DUCT IN NEWBORNSalternative to a surgical AP-shunt might be percuta-neous ductal stenting.1–9At some institutions,duc-tal stenting is the procedure offirst choice to palli-ate newborns with duct-dependent pulmonary blood flow(Alwi M.,personal communication,PICS,World Congress2009,Cairns,Australia).However,contro-versy exists as PDA stenting is technically difficult5,9,10 Based on our previous experience of ductal stenting in newborns with cyanotic CHD,4the aim of this study was to report the current results in another27neonates with emphasis on the technical aspects,complications, and outcomes.Percutaneous PDA stenting is not an approach that “MUST”be but“CAN”be performed in selected pa-tients.After birth,while maintaining ductal patency with PGE1infusion the decision for stenting might be made as an alternative to a surgical AP-shunt.With regards to the PDA morphology there are no exclusion criteria for an interventional procedure,although if ad-ditional surgery were required a catheter stent place-ment was not considered.Cardiac catheterization can be electively planned when postnatal adaptation of the pulmonary vascular system is observed by echocardio-graphy using the pressure gradient across the PDA.In addition,the vascular access is determined by morpho-logical criteria obtained by echocardiography and/or cardiac magnetic resonance imaging.Right axillary access is considered when the origin of the PDA is positioned opposite to the brachiocephalic artery,and venous access through the ventricle is impossible or unfavorable,that is,in the presence of ventricular fail-ure or significant atrioventricular valve regurgitation. Left axillary access is preferred when femoral artery access and the retrograde PDA stenting seem to be more difficult than a procedure from the left arm with a subclavian artery positioned exactly oppositely to the PDA arising from the inner curve of the aortic arch.13From the technical point of view,the two-wire technique is important for a successful interventional approach,particularly in newborns with complicated PDA morphology.In this context,it is essential to re-member the rule:“Never give up a wire already placed through the PDA”before the next step of the procedure is completed.Predilation with a low profile balloon catheter is recommended in case of preexisting ductal obstruction at the aortic or pulmonary artery site to al-low safe stent deployment.We favor the use of an Apex 3×20mm(Boston Scientific).Crossing the PDA with aflexible balloon catheter improves the examiner’s ap-praisal for the stenting approach.A PDA with a tortu-ous course and/or stenotic part shouldfirst be passed with a3-mm balloon catheter to prove wire stability and to test the feasibility of the stent-balloon passage through the PDA to the pulmonary artery.12Crossing the PDA and positioning the balloon catheter in the pul-monary arteries allows easy wire exchange,which can be facilitated by balloon inflation within a pulmonary artery branch.Once a stiff support wire is positioned, the passage of the premounted coronary stent through the PDA is generally easily possible.Whenever tech-nically possible,the stiff wire should be safely placed and looped within the pulmonary trunk(if present), or to the side of a preexisting stenosis,in case of a significant pulmonary branch obstruction,for the fol-lowing reasons:First,a stent directed to the pulmonary trunk optimizes perfusion to both lungs;second,ductal stenting curved to a congenitally obstructed pulmonary branch is an option for augmentingflow to the affected lung whereas bloodflow through the struts allowsflow to the unobstructed pulmonary branch.If insufficient, dilatation of the struts might be an additional treatment, as done in1patient in this series.It is important to ac-knowledge that after placement of a stiff wire the ductal shape may change from a tortuous to a straight mor-phology,which can affect the length and morphology of the PDA and lead to a misinterpretation consider-ing stent length.Stenting should always be started at the distal point of the PDA with covering the insertion of the pulmonary part in total.This was not achieved in2patients in our series and complicated the proce-dure with regards to advancing a second stent through thefirst one,causing friction of the2implants during positioning.Hence,in an extremely long and tortuous PDA it is more appropriate to advance two or three shorter stents within the PDA using a telescoping tech-nique rather than to utilize a bulky long premounted stent,which might be impossible to deliver through a PDA with tortuous morphology.Despite optimal stent placement removal of the deflated balloon may be chal-lenging without causing stent migration.In this con-text,a tortuous and stenosed PDA allowsfirmfixa-tion and stable positioning during balloon extraction in comparison to a straight,short,unobstructed PDA connecting the proximal descending aorta to the roof of the main pulmonary artery near to the left pulmonary artery branch.The best results for uncomplicated re-moval of the deflated balloon were achieved by using a stiff guidewire.Aiming for optimal deflation of the bal-loon,different types of premounted coronary balloonSCHRANZ,ET AL.stents were used;we are currently favoring the Driver stent.The procedure of ductal stenting can be performed within60–90minutes,withfluoroscopy times between 5and20minutes.After an observation period of about 8days without further PGE1therapy and adequate arte-rial oxygenation(aiming for80–85%)the patients are discharged home without aspirin.Only in telescopic stented PDA utilizing2or3stents was antiplatelet medication prescribed.The aim of this study was to analyze our results regarding strengths and weaknesses of an interven-tional approach of ductal stenting in neonates with truly PDA-dependent pulmonary bloodflow.In an optimal setting,aiming for follow-up surgery at3–6months, ductal stenting is a feasible and an efficient approach to replace a surgical AP-shunt not only as shown in dual-sourced pulmonary perfusion,17but also in true duct dependency.Successful ductal stenting can only be achieved by a sufficient stock of equipment in the cardiac catheterization laboratory and operator skills. Hand-crimped stents carry the risk of stent emboliza-tion by slipping off the balloon,particularly during retrieval through the delivery sheath,and should not be further utilized.Ductal spasm during continuous PGE1infusion is rare,the described wire technique is extremely important for success.We did not observe any ductal injury in our series.However,in the case of duct dissection or aneurysm formation a covered coro-nary stent needs to be available.It is crucial to confirm stent coverage of the entire PDA before removal of the wire.If,in a curved PDA,the aortic insertion is not fully covered,reintervention is problematic,with a risk for major complications and the necessity for immediate surgical AP-shunt placement.Hence,reintervention,if considered,requires surgical stand-by and a second in-tervention has to be weighted against the decision for a surgical AP-shunt instead.In conclusion,with advancements in minimal inva-sive interventional cardiac catheterization procedures neonatal ductal stenting with truly duct-dependent pul-monary circulation is a reliable and safe procedure.It is a unique technique with low complication rates that will continue to evolve into an important alternative to the surgical AP-shunt.Implementing the results pre-sented in this study may reduce the need for a surgical AP-shunt,and prolong the patency of a stented PDA by improving technique and avoiding strategic mistakes.A randomized multicenter study to compare percuta-neous ductal stenting with a surgically performed AP-shunt is warranted.References1.Alwi M,Choo KK,Latiff HA,et al.Initial results and medium-term follow-up of stent implantation of patent ductus arteriosus in duct-dependent pulmonary circulation.J Am Coll Cardiol 2004;44(2):438–445.2.Mahesh K,Kannan BR,Vaidyanathan B,et al.Stenting thepatent arterial duct to increase pulmonary bloodflow.Indian Heart J2005;57(6):704–708.3.Schneider M,Zartner P,Sidiropoulos A,et al.Stent implan-tation of the arterial duct in newborns with duct-dependent circulation.Eur Heart J1998;19(9):1401–1409.4.Michel-Behnke I,Akit¨u rck H,Thul J,et al.Stent implantationin the ductus arteriosus for pulmonary blood supply in congen-ital heart disease.Catheter Cardiovasc Interv2004;61(2):242–252.5.Gewillig M,Boshoff DE,Dens J,et al.Stenting the neonatalarterial duct in duct-dependent pulmonary circulation:New techniques,better results.J Am Coll Cardiol2004;43(1):107–112.6.Alwi M,Kandavello G,Choo K,et al.Risk factors for augmen-tation of theflow of blood to the lungs in pulmonary atresia with intact ventricular septum after radiofrequency valvotomy.Cardiol Young2005;15(2):141–147.7.Santoro G,Bigazzi MC,Cainiello G,et al.Transcatheter pallia-tion of congenital heart disease with reduced pulmonary blood flow.Ital Heart J2005;6(1):35–40.8.Qureshi SA.Catheterization in neonates with pulmonary atre-sia with intact ventricular septum.Catheter Cardiovasc Interv 2006;67(6):924–931.9.Santoro G,Gaio G,Palladino MT,et al.Stenting of the arterialduct in newborns with duct-dependent pulmonary Circulation.Heart2008;94(7):925–929.10.Gibbs JL.Ductal stenting for restricted pulmonary bloodflowin neonates:15years on but still a very limited place in clinical practice.Editorials Heart2008;94(7):834–835.11.Schranz D.Stenting the arterial duct.In Hijazi ZM,FeldmanT,Cheatham JP,Sievert H,plications during percu-taneous interventions for congenital and structural heart rma Healthcare UK Ltd.,London,2009,pp.131–144.12.Boshoff DE,Michel-Behnke I,Schranz D,et al.Stenting theneonatal duct.Expert Rev Cardiovasc Ther2007;5(5):893–901.13.Schranz D,Michel-Behnke I.Axillary artery access for cardiacinterventions in newborns.Ann Pediatr Cardiol2008;1(2):126–130.14.Li JS,Yow E,Berezny KJ,et al.Clinical outcomes of palliativesurgery including a systemic-to-pulmonary artery shunt in in-fants with cyanotic congenital heart disease.Does aspirin makea difference?Circulation2007;116(3):293–297.15.Al Jubair KA,AlFagih MR,Jarallah AS,et al.Results of546Blalock-Taussig shunts performed in478patients.Car-diol Young1998;8(4):486–490.16.Yuan SM,Shinfeld A,Raanani E.The Blalock-Taussig shunt.J Card Surg2009;24(2):101–108.17.Santoro G,Capozzi G,Caianiello G,et al.Pulmonary arterygrowth after palliation of congenital heart disease with duct-dependent pulmonary circulation:Arterial duct stenting versus surgical shunt.J Am Coll Cardiol2009;54(23):2180–2186.。