Stenting stenosed aortopulmonary collateral arteries in pulmonary atresia with ventricular septal defect

We present two cases of pulmonary atresia with ventricular septal defect who were not suitable for corrective surgery due to absent or hypoplastic native pulmonary arteries and were quite symptomatic following shunt surgery. We dilated and stented stenosed aortopulmonary collaterals as palliative procedure with improvement in oxygen saturation, and significant symptomatic relief.     

Transcatheter left ventricular outflow tract stent placement in a low birth weight child with hypoplastic left ventricle,mitral atresia,transposition of the great arteries,ventricular septal defect and severe pulmonary stenosis

A baby boy, the first of triplets born at 33 weeks gestation weighing 1.88 kg, presented with neonatal cyanosis and was diagnosed with mitral atresia, hypoplastic left ventricle, ventricular septal defect, d‐transposition of the great arteries, severe pulmonary stenosis, and hypoplastic branch pulmonary arteries. He was treated with prostaglandin until seven weeks of age. The patent ductus arteriosus was curly Q and not suitable for stent placement. Cardiac catheterization was undertaken and using an antegrade approach, a Multi‐Link Ultra stent was implanted across the left ventricular outflow tract (LVOT) and inflated to 5 mm to improve antegrade pulmonary blood flow. This allowed reasonable pulmonary arterial growth to allow the patient undergo bidirectional Glenn shunt at five months of age. This first report of LVOT stenting in this setting may provide an alternative to placement of a systemic to pulmonary arterial shunt when ductal stenting is not possible. © 2013 Wiley Periodicals, Inc.     

Use of small stents for rehabilitation of hypoplastic pulmonary arteries in pulmonary atresia with ventricular septal defect.

Branch pulmonary artery stenosis frequently occurs in pulmonary atresia with ventricular septal defect (PA/VSD). Balloon dilation alone is often unsuccessful in patients with severely hypoplastic pulmonary arteries with residual stenoses after surgical repair. In an attempt to promote distal pulmonary artery growth, 17 stents were placed in 12 severely stenotic pulmonary artery lesions in 10 patients with PA/VSD. All had prior surgery, including pulmonary artery repair, right ventricle to pulmonary artery homograft, and, in 6 of 10, closure of VSD. Median age at stent placement was 16.8 months (range, 13.2-56). Stents were placed using 3.0, 3.5, or 4.0 mm balloons in all but one lesion, in which a 7 mm balloon was used. Following stent placement, there was an increase in the lesion diameter from 1.5 to 3.4 mm (P < 0.05) and an increase in flow to the affected lung from 27% to 34% (P < 0.05). Repeat catheterization 2 to 6 months after stenting in six patients revealed complete occlusion in two of eight lesions. In the other six vessels, there was an increase in distal vessel diameter from 2.96 to 3.94 mm (P < 0.05) even though four had severe restenosis requiring restenting. Two patients underwent surgical pulmonary artery reconstruction and stent removal because of adequate distal vessel growth. Stenting of hypoplastic pulmonary arteries in PA/VSD results in immediate improvement in vessel size and blood flow. Stent restenosis is common although distal vessel growth can be achieved. Stenting of these lesions should be reserved only for those patients unresponsive to other interventions.     

Alterations in reference vessel diameter following intracoronary stent implantation: Important consequences for restenosis based on percent diameter stenosis

The scaffolding effect of stent implantation has the potential to alter vascular geometry and dimensions. The objective of this study was to determine the impact of intracoronary stent implantation on the reference vessel diameter and the consequences of this on the frequency of restenosis applying the binary definitions of restenosis based on percent diameter stenosis. Routine angiographic follow-up was performed in 79/80 consecutive patients who had a single elective Palmaz-Schatz stent implanted in denovo lesions in native coronary arteries 6.5±3.4 mo after the index procedure. Complete quantitative angiographic follow-up was available in 78 (98%). The mean reference vessel diameter was 2.9±0.6 mm preprocedure, increased to 3.1±0.5 mm immediately poststent implantation and was 2.6±0.6 mm at follow-up (F = 6.45, P = 0.0001, ANOVA for repeated measures). In view of the varying reference vessel diameter, percent diameter stenosis postangioplasty and at follow-up was determined by two methods: (1) automatically by the quantitative coronary angiographic analysis system and (2) by expressing the minimal luminal diameter postangioplasty and at follow-up as a function of the original preprocedural reference vessel diameter. The restenosis rate was significantly greater for all definitions of restenosis when the minimal luminal diameter was determined as a function of the original preprocedure reference vessel diameter (e.g., 34% vs. 18% for the ?50% criterion, P = 0.018). Stent implantation results in alterations in reference vessel diameter, which have important consequences for the frequency of restenosis presented as a binary variable based on percent diameter stenosis. © 1995 Wiley-Liss, Inc.     

Growth and development of pulmonary circulation in pulmonary atresia with ventricular septal defect and major aortopulmonary collateral arteries.

Twenty-four-hour electrocardiograms were recorded in the first 10 days of life on 134 healthy full-term infants with birthweights greater than 2.5 kg. The highest heart rate a minute, measured over nine beats, was 175 +/- 19 (SD). The lowest rates, measured over three, five, and nine beats were 82 +/- 12, 87 +/- 12, and 93 +/- 12, respectively. At their lowest rates 109 infants had sinus bradycardia and 25 had junctional escape rhythms. Thirty-three infants showed changes in P wave configuration with or without pronounced variation in PR interval. Atrial premature beats were present in 19 infants but only one had more than 12 per hour. In a randomly selected subgroup of 71 infants sinus pauses were found in 51 (72%). Five (7%) had electrocardiographic patterns and rhythm disturbances that could not be differentiated from those previously described as complete sinuatrial exit block or sinus arrest, eight (11%) had patterns indistinguishable from 2:1 sinuatrial block, and 23 (32%) had pattern indistinguishable from sinuatrial Wenckebach block. This study shows that normal infants have variations in heart rate and rhythm hitherto considered to be abnormal.     

血管外PHA生物支架抑制移植静脉狭窄的应用价值

目的观察血管外聚羟基烷酸酯（PHA）可降解生物支架对移植静脉内膜增生的影响,探讨其应用价值及可能的作用机制,为临床治疗血管再狭窄提供新方法和理论依据。方法采用袖套法将大鼠自体颈外静脉移植入同侧颈动脉,根据有无支架干预分为对照组和支架组。术后1、2、4周分别切除移植静脉,应用病理形态学方法检测移植静脉外膜新生血管密度,计算机图像分析系统测量和计算内膜厚度。免疫组化法检测其增殖细胞核抗原（PCNA）指数、移植静脉局部核转录因子-κB（NF-κB）和转化生长因子-β1（TGF—β1）的表达。结果支架组移植静脉内膜增生程度、PCNA指数、NF-κB和TGF—β1的表达均低于对照组（P〈0．05）,移植静脉外膜新生血管密度明显高于对照组（P〈0．05）。结论血管外PHA可降解生物支架防治移植静脉狭窄有一定作用,其抑制移植静脉狭窄的机制可能与其下调NF—κB、TGF—β1的表达及促进移植静脉外膜血管生成有关。     

Pulmonary atresia with ventricular septal defect and major aortopulmonary collateral arteries. Effect of systemic pulmonary anastomosis.

In nine patients with pulmonary atresia, ventricular septal defect, and major aortopulmonary collateral arteries, the effect of a systemic-pulmonary anastomosis on the lung was studied by comparison of pre- and postoperative cine angiograms. Selective injections into the collateral arteries were performed in all patients and the source of blood supply to each bronchopulmonary segment was sought. Central pulmonary arteries were present in six children and absent in three, as confirmed at thoracotomy. After insertion of a shunt, central pulmonary arteries increased in size, but the intrapulmonary vessels with which they connected remained abnormally small and were frequently stenosed. In addition, in each case the central pulmonary arteries increased flow to only five to 11 segments of lung. In the absence of central pulmonary arteries, shunting to a hilar or a lobar pulmonary artery increased perfusion to five to nine segments of lung per case. In all these three cases the pulmonary arteries at lobar level showed aneurysmal dilatation proximal to a severe stenosis. Sixty-eight per cent of collateral arteries were stenosed. The findings suggest that in this anomaly, when the central pulmonary arteries are hypoplastic, the intrapulmonary branches are also hypoplastic, emphasising the need for early surgical intervention to increase blood flow while the lung still has growth potential. Further, one collateral artery may connect with at least as many bronchopulmonary segments as does a central pulmonary artery, and the peripheral intrapulmonary arteries with which it connects may appear at least as normal angiographically as do vessels connected to central pulmonary arteries. These observations suggest that segments of lung connected to collaterals alone should, and sometimes can, be connected to central pulmonary arteries, the aim being to produce a unifocal blood supply as a prelude to total correction.     

Simultaneous kissing stent in a patient with severe bifurcation pulmonary vein stenosis

Pulmonary vein stenosis (PVS) is a late and rare complication of pulmonary vein isolation for the treatment of atrial fibrillation. The ideal approach to the management of PVS has not yet been established, however, corrective procedures may include both surgical and percutaneous techniques. We describe the case of a complex bifurcation lesion involving the left superior pulmonary vein. The condition required percutaneous intervention using a modified kissing stent technique with bare metal stents that resulted in an excellent post‐operative course, sustained symptomatic relief, and uncomplicated 1‐year follow‐up. © 2014 Wiley Periodicals, Inc.     

First successful implantation of a biodegradable metal stent into the left pulmonary artery of a preterm baby.

Stent implantation in the youngest patients with a congenital heart disease implicates limitations concerning further vessel growth, the need of staged redilation, and later surgical removal. The search to overcome these restrictions led to open stent designs, with a wide adaptability to the vessel growth and recently to the development of bioabsorbable stent materials. A preterm baby born at 26 weeks of gestation was referred to our clinic following inadvertent ligation of the left pulmonary artery. Despite efficient debanding, the left lung perfusion was absent. Implantation of a biodegradable 3 mm magnesium stent was performed in a hybrid procedure when the baby weighed 1.7 kg. Reperfusion of the left lung was established and persisted throughout the 4-month follow-up period during which the gradual degradation process of the stent completed. Additional interventions, should they become necessary, seem not to be limited. Despite the small size of the baby, the degradation process was clinically well tolerated. The mechanical and degradation characteristics of the magnesium stent proved to be adequate to secure reperfusion of the previously occluded left pulmonary artery. Bioabsorbable stents with different diameters may help develop new strategies in the therapy of vessel stenosis in pediatric patients.     

Transcatheter radiofrequency perforation and stent implantation for palliation of pulmonary atresia in a 3060-g infant

In a 3060-g infant with fibromuscular pulmonary atresia an open right ventricular outflow tract was created by means of interventional cardiological methods. Following two inadvertent perforations without sequelae or clinical symptoms, radiofrequency perforation and subsequent balloon dilatation were successfully performed. The implantation of a Palmaz iliac stent led to a predictable communication between the right ventricle and pulmonary artery.     

Late restenosis following placement of a sirolimus eluting stent for in-stent restenosis

Drug eluting stents (DES) are rapidly replacing intravascular brachytherapy for the treatment of bare metal in-stent restenosis (ISR). To date, there are no long-term follow up data supporting this practise. We report symptomatic repeat in-stent restenosis occurring 27 months after sirolimus eluting stent deployment for de novo in-stent restenosis. This case suggests that in a subgroup of patients with ISR, as with brachytherapy, the drug eluting stent may be simply delaying rather than inhibiting the restenotic process.     

Monosomy 22q11 in patients with pulmonary atresia, ventricular septal defect, and major aortopulmonary collateral arteries

Objective—To describe the morphology of the pulmonary arteries in patients with pulmonary atresia, ventricular septal defect, and major aortopulmonary collateral arteries with and without monosomy 22q11.
Design—A retrospective analysis of all patients with this congenital heart defect who are being followed at the University Children's Hospital Erlangen.
Setting—A tertiary referral centre for paediatric cardiology and paediatric cardiac surgery.
Patients—21 patients with pulmonary atresia, ventricular septal defect, and major aortopulmonary collateral arteries. Monosomy 22q11 was diagnosed by fluorescent in situ hybridisation using the D22S75 probe (Oncor). The morphology of the pulmonary arteries was assessed on the basis of selective angiograms.
Results—10 patients (48%) were shown to have a microdeletion in 22q11 (group I). There was no difference with respect to the presence of confluent central pulmonary arteries between these patients (80%) and the remaining 11 patients (group II) without monosomy 22q11 (91%). Patients of group I, however, more often had arborisation anomalies of the pulmonary vascular bed (90% in group I v 27% in group II). Because of the more severe abnormalities of the pulmonary arteries, a biventricular repair had not been possible in any of the children with monosomy 22q11, though repair had been carried out in 64% of the children in group II.
Conclusions—The developmental disturbance caused by monosomy 22q11 seems to impair the connection of the peripheral pulmonary artery segments to the central pulmonary arteries in patients with pulmonary atresia, ventricular septal defect, and major aortopulmonary collateral arteries, resulting in a lower probability of biventricular repair.

Keywords: CATCH 22;  pulmonary atresia and ventricular septal defect;  major aortopulmonary collateral arteries;  conotruncal anomaly face syndrome     

Stent design-related coronary artery remodeling and patterns of neointima formation following self-expanding and balloon-expandable stent implantation.

The self-expanding Wallstent (WS) and balloon-expandable Palmaz-Schatz stents (PS) display different mechanical and dynamical stent properties. We analyzed the impact of the respective stent design on coronary wall geometry using quantitative coronary angiography (QCA) and intracoronary ultrasound (ICUS) measurements. Serial measurements were performed within the stent and within reference segments of 50 patients (25 WS, 25 PS). Relative changes for each parameter in both stent designs were calculated (Mann-Whitney U-test; 95% CI). The luminal net gain in WS was not significantly higher in WS compared with PS (1.63 +/- 1.11 vs. 1.44 +/- 0.63 mm; P = 0.2554). The respective loss indexes were also similar (0.38 +/- 0.42 vs. 0.36 +/- 0.23; P = 0.8578). The WS segments showed significant postinterventional stent expansion with positive vessel remodeling. The neointima formation was significantly higher in WS segments (4.23 +/- 2.07 vs. 2.22 +/- 2.22 mm(2)). The coronary wall morphology and stent geometry after 6.5 +/- 1.2 months are related to the stent design. In WS segments, the neointima formation was balanced by postinterventional stent expansion, resulting in a comparable relative lumen loss in both stent types. The respective stent design had no impact on the vessel reference segments.     

经皮冠状动脉内血管成形术中冠状动脉内支架的应用

在经皮冠状动脉内血管成形术(PTCA)中,16例患者因发生冠状动脉内膜剥离,血管急性闭塞及再狭窄而放置冠状动脉内支架,成功15例,认为冠状动脉内支架可有效地防止PTCA术急性并发症(内膜剥离、夹层形成,血管急性闭塞等)的发生.     

Six-month results of a biodegradable polymer and rapamycin-coating stent for coronary artery disease

Objective To assess the safety and efficacy of a novel biodegradable polymer and rapamycin-coating stent, the EXCEL stent, in the treatment of coronary artery disease (CAD), as compared with the Cypher?stent. Methods In this prospective, non-randomized study, 60 consecutive patients with symptomatic CAD received either an EXCEL stent (n=32), or a CypherTM stent(n=28),according to their respective treatment intention. Follow-up angiography was performed at a mean of 180±40 days. The primary endpoint of the study was the occurrence of a major adverse cardiac event (MACE), including death, myocardial infarction, or target-vessel revascularization during the 6 months after stenting. The secondary end points included the in-stent late luminal loss (LLL), percentage of in-stent stenosis of the luminal diameter, and the rate of restenosis (luminal narrowing of 50 percent or more) at 6 months. Results There were no significant differences between the two groups in baseline characteristics, including the distribution of target vessel and lesion types. During the follow up period of 6 months, there were no occurrences of MACE in either group. Twenty-seven patients (84%) in the EXCEL group and 10 (36 %) in the Cypher?group underwent quantitative coronary angiography at 6 months. For these patients, no restenosis occurred, and there were no differences in the in-stent stenosis of the luminal diameter (5.98±5.52 % vs 5.21±6.3%, P>0.05) and the LLL (-0.02±0.09 mm vs -0.01±0.07 mm, P>0.05). Conclusions Compared with the CypherTM stent, the EXCEL Stent with biodegradable polymer and rapamycin-coating showed similar efficacy in the prevention of neointimal proliferation, restenosis, and associated clinical events in CAD patients.     

Early clinical experience with the implantation of a novel synthetic coronary stent graft

Coating stents with autologous venous grafts has been suggested to prevent problems associated with conventional stenting, but the need for surgical vessel harvest hampered broad application. A novel synthetic coronary stent graft (CSG) overcomes this limitation by a synthetic membrane, fixed between two thin metallic stents. We successfully implanted 21 CSGs in 18 patients for treatment of acute coronary rupture, thrombus-containing lesions, and lesions with plaque rupture or adjacent pseudoaneurysm. Substantial residual angiographic diameter stenoses were seen in seven CSGs (25% ± 10% vs. 8% ± 6%; P < 0.01), which were implanted with relatively small balloon catheters (balloon-to-artery ratio 1.00 ± 0.09 vs. 1.24 ± 0.18; P = 0.01) and required postdilatation. Overall, the largest balloon catheter applied measured 4.0 ± 0.7 mm (balloon-to-artery ratio 1.21 ± 0.20) and the inflation pressure was 16 ± 3 atm. Final intravascular ultrasound imaging demonstrated adequate and symmetrical expansion of the CSG (≥85% ± 15% of the reference lumen). Elective implantation was associated with two small non–Q-wave myocardial infarctions, resulting from unavoidable occlusions of side branches. Thus, implantation of CSG is feasible and safe. Adequate expansion can be achieved by the use of relatively large low-compliant balloon catheters inflated with high pressure. Cathet. Cardiovasc. Intervent. 47:496–503, 1999. © 1999 Wiley-Liss, Inc.     

First biodegradable metal stent in a child with congenital heart disease: evaluation of macro and histopathology.

New developments in stent technology led to the first biodegradable magnesium stents. To overcome the fundamental restrictions of conventional stent implantation, these new stents may improve interventional therapy, also in small children. What remains after complete degradation of a magnesium stent is of particular interest and concern. At the autopsy, 2 months after the projected complete degradation time of the 3.0 x 10 mm(2) stent, no solid compounds were detected, and the vessel diameter had increased slightly to 3.7 mm. Histological preparation revealed an amorphous to jelly-like substitute of the magnesium struts mainly consisting of calcium phosphate covered by fibrotic tissue. Immunological staining revealed no relevant inflammatory reaction to the stent material. Neointima proliferation was detected around the struts with some cellular infiltration of the calcium-phosphate material. These pathological and histological findings show minimal alteration of the vessel wall and an increase of the arterial diameter after stent degradation. This is an important precondition for further use of biodegradable stents in small infants. Further observations have to prove whether these findings do reproduce in other settings also.