Spring coil retraction in coil occlusion of persistent ductus arteriosus

Aims—To present the short and intermediate term results of coil occlusion of persistent ductus arteriosus and the results of radiographic measurements of spring coils implanted to treat patent ducts.
Patients—22 children underwent coil occlusion. Their ages ranged from 2 years 9 months to 12 years 10 months (mean (SD) age, 6.5 (3.6) years). The duct diameter ranged from 1.0 to 3.5 mm at the narrowest point (mean 2.6 (0.7) mm). In 11 of the children regular coils were implanted using the non-attached system, while in the other 11 the detachable coil embolisation system was used.
Results—12 children (55%) had no significant residual leaks immediately after procedures involving a single coil delivery. The remaining 10 (45%) had residual leaks immediately after the procedure, although no patient with a large duct showed residual leakage 18 months after the procedure. Radiographic measurement of the coils showed that all implanted coils retracted to 65-85% of their original size immediately after occlusion. This retraction was more evident in patients showing spontaneous closure of the residual shunt or having a coil 8 mm in diameter.
Conclusions—Coil embolisation is an acceptable method for occluding persistent ductus arteriosus. Retraction of implanted coils is common in the follow up period. Such retraction may be related to spontaneous closure of residual shunt after embolisation.

Keywords: persistent ductus arteriosus;  catheter occlusion;  coil embolisation     

Transcatheter closure of fenestrations and excluded hepatic veins after fontan: versatility of the Amplatzer device

BACKGROUND: The aim of this study was to evaluate the Amplatzer septal occluder (ASO) for transcatheter closure of fenestrations and excluded hepatic veins in patients after modified Fontan operations. Residual right-to-left shunts have improved surgical results of the Fontan operation. Shunt closure may eventually be desirable to eliminate hypoxemia and reduce risk of embolic complications. METHODS AND RESULTS: Ten patients with hypoxemia caused by residual shunts after Fontan procedures were evaluated for closure. After favorable results of test occlusion, all shunts were closed with the use of the ASO. Eight ASOs were used to close fenestrations in 7 patients with 6F transvenous sheaths. Three ASOs were used to close excluded hepatic veins in 3 patients with 6F venous sheaths and transbaffle punctures. Fluoroscopy and transesophageal echocardiography were used to guide device placement. Device placement in all patients was successful. All shunts were closed by angiography after device placement. While breathing room air, systemic oxygen saturation rose from 87.9% +/- 3.0% to 96.3% +/- 0. 9% (P <.001) in the patients. There were no complications of the implant procedures and none noted in outpatient follow-up. CONCLUSIONS: This experience suggests that the ASO is safe and effective for closing surgical shunts after Fontan procedures. The ASO design allows closure of excluded hepatic veins and has advantages over other devices in closure of fenestrations.     

Aneurysms and pseudoaneurysms of saphenous vein coronary artery bypass grafts

Aneurysms of saphenous vein grafts to coronary arteries are unusual complications of coronary artery bypass graft (CABG) surgery. Three patients (men aged 47, 62, and 68 years) are presented with spontaneous chest pains 10, 21, and 17 years after CABG surgery. In one case, the saphenous vein graft had eroded into the right atrium and had established a fistula between the graft and the right atrium. Diagnosis of saphenous vein graft aneurysms was confirmed by echocardiography, computed tomography or magnetic resonance imaging, and by arteriography. Two patients were treated surgically, the third by percutaneous coil embolisation followed by balloon angioplasty of the right coronary artery.

Keywords: aneurysm;  pseudoaneurysm;  saphenous vein grafts;  coronary artery bypass graft     

S-Nitrosoglutathione inhibits platelet activation and deposition in coronary artery saphenous vein grafts in vitro and in vivo

Objective—To investigate platelet activation and deposition in human saphenous vein and internal mammary artery grafts following coronary artery bypass in vitro and in vivo, as well as inhibition of activation by the platelet selective nitric oxide donor S-nitrosoglutathione (GSNO).
Design—Controlled in vitro and in vivo studies.
Setting—Tertiary cardiac centre.
Patients—24 patients undergoing coronary artery bypass surgery requiring vein and artery grafts.
Interventions—In vitro: human platelet rich plasma was perfused through segments of vein and artery, with or without GSNO 10^-6 M, and the platelet count was measured in the effluent. In vivo: indium-111 labelled antibody against the platelet α granule protein GMP-140 was injected at the end of coronary bypass grafting and γ counts were compared between vein and artery grafts with or without systemic infusion of GSNO (40 nmol/min).
Results—In vitro: platelet count in perfused vein (< 70% of baseline) decreased more than in artery segments (89-94% of baseline) (p < 0.001). The platelet count was unchanged with GSNO in vein and artery segments. In vivo: γ counts were greater at all time points over vein than artery grafts (p < 0.05), and were reduced by infusion of GSNO (p < 0.05).
Conclusions—Platelet activation is greater in vein than in artery grafts in vitro and in vivo. Activation, which contributes to early vein graft failure, was inhibited by GSNO.

Keywords: coronary artery bypass surgery;  platelet activation;  S-nitrosoglutathione;  ischaemic heart disease     

Endoluminal vessel reconstruction by stent placement in patients with obstructive coronary artery disease who are poor surgical candidates

Objective—To investigate the safety and efficacy of endoluminal vessel reconstruction by intracoronary stenting in patients with single or multivessel disease who have been turned down for surgical revascularisation.
Design—An observational, single centre trial of consecutive patients being followed up clinically.
Setting—Tertiary referral centre.
Patients—43 patients treated between 1995 and 1996 with a clinical follow up period of at least six months.
Main outcome measures—Acute procedural success following intervention (defined as a residual stenosis of < 30% with normal antegrade flow and without acute clinical complications); major adverse clinical events (death, myocardial infarction, repeat intervention, clinical restenosis); and functional status during follow up.
Results—Acute procedural success was achieved in 39 patients. Failures resulted from a refractory no reflow phenomenon with Q wave myocardial infarction (two patients), and from subacute stent thrombosis (one patient) and saphenous vein graft rupture at stent site (one patient), both manifesting by non-Q wave myocardial infarction. During a follow up period of 17 (8) months (mean (SD)), three of these patients died. Clinical restenosis was treated by repeat percutaneous intervention in 11 patients, while 28 patients remained asymptomatic. On a Kaplan-Meier estimate, the proportion of patients without adverse clinical events at two years was 65%.
Conclusions—Percutaneous reconstruction of diseased coronary arteries in patients with single or multivessel disease turned down for surgical revascularisation may be considered as a valuable treatment option. On follow up, more events seem to be encountered than after elective de novo stenting of discrete coronary lesions. This is probably related to higher clinical restenosis rates.

Keywords: coronary artery disease;  stents;  restenosis     

Major intrahepatic veno-venous fistula after modified Fontan operation treated by transcatheter implantation of amplatzer septal occluder

Patients with complex congenital cardiac malformations who have been converted to the Fontan circulation with partial exclusion of the hepatic veins may develop progressive cyanosis because of formation of intrahepatic veno-venous malformations. We describe transcatheter closure of a major intrahepatic fistula in such a setting using an Amplatzer septal occluder delivered by the left jugular venous approach in a 5 year old boy.     

Transcathater percutaneous device closure of a large PDA closed in a 3 kg infant

Patent ductus arteriosus (PDA) is common congenital heart disease which may require treatment as transcatheter percutaneous device closure (PDA device closure) or surgical ligation in symptomatic full-term patients. Surgical ligation is an invasive procedure and has more complications especially in the neonates. Problems in PDA device closure are difficult vascular access, manipulation of catheters and sheath, residual shunts, residual obstruction of major arteries etc and these complications increase in low birth weight babies, but it is a less invasive procedure and has fewer complications than surgery, so should be tried in low birth weight patients also. We are presenting a case of 3 kg infant with large PDA (8 mm) presented with failure to thrive, lower respiratory tract infection and heart failure. He successfully underwent PDA device closure with 10 × 12 mm Cocoon PDA device. To the best of our knowledge, this is the first case of the use of such a large device in a 3 kg child with good results.     

Transcatheter occlusion of a residual left superior vena cava causing right-to-left shunt in a Fontan patient with a new occlusion device.

We describe the management of a residual left superior vena cava connected to the coronary sinus and causing right-to-left shunt at atrial level in an 8 year-old-child, with modified Fontan operation (total cava pulmonary connection) by transcatheter closure with a new duct occluder device.     

Residual and recurrent shunts after implantation of Cook detachable duct occlusion coils

Objective—To assess the presence and outcome of Doppler detectable shunts following implantation of the Cook detachable PDA coil.
Design—Prospective study.
Setting—Tertiary paediatric cardiac centre.
Patients—76 consecutive patients undergoing coil implantation (80 procedures).
Main outcome measures—Detection and colour Doppler echocardiographic appearance of residual or recurrent shunts, the timing of the appearance of recurrent shunts, and the time taken for spontaneous resolution of these shunts.
Results—Immediate occlusion was achieved in 52 patients. At one month 63 patients had complete occlusion and after three months the duct was completely occluded in 67 patients. In 27 cases small residual shunts were detected on echocardiography 10 minutes after the completion of the implantation procedure; 15 of these had resolved by 24 hours and 20 had resolved by three months. Recurrent shunts were detected after apparent initial complete occlusion in 11 cases 24 hours after coil implantation and in two cases one month after the procedure. Six recurrent shunts resolved on later follow up. Residual shunts appeared as single jets after implantation of a single coil, but up to three separate jets were detected after implantation of multiple coils.
Conclusions—Spontaneous resolution of small residual shunts occurs in most patients. The recurrence of small shunts after apparent complete occlusion suggests that recanalisation of the duct may occur in a small percentage of patients up to one month after occlusion. Residual shunts may take the form of multiple residual jets that may require implantation of further coils to achieve complete duct occlusion.

Keywords: coil occlusion;  arterial duct;  congenital heart disease     

Papillary endothelial hyperplasia in a TEC coronary atherectomy specimen.

Angiography in a 37 year old female with a three week history of typical crescendo angina found an 80% stenosis of the proximal left anterior descending (LAD) artery. The patient underwent percutaneous transluminal coronary angioplasty involving TEC artherectomy of the LAD artery. The specimen removed by atherectomy was found to have the appearance of papillary endothelial hyperplasia. This is an unusual histological diagnosis that occurs in association with thrombus. It is rarely found within arterial vessels and has not been reported in a coronary artery. Papillary endothelial hyperplasia is now thought to be a form of organising thrombus, probably dependent on the production of basic fibroblast growth factor by the endothelium.     

Transcatheter closure of atypical right-to-left shunts after Fontan surgery

Atypical right-to-left shunts following Fontan surgery were closed by transcatheter techniques using various devices in 4 patients. Three had variants of hypoplastic left heart syndrome, while the other had tricuspid atresia. Large Fontan baffle leaks were present in 2, a residual fistula from the inferior vena cava to the coronary sinus was present in 1, and another patient had surgical tube fenestration of an extracardiac conduit. When careful catheter and transesophageal echocardiographic exploration is performed, the selection of appropriate devices makes closure of these defects feasible.     

Plasma concentrations of adrenomedullin correlate with the extent of pulmonary hypertension in patients with mitral stenosis

Objective—To examine the pathophysiological significance of adrenomedullin in the pulmonary circulation by investigating the relation between plasma concentrations of adrenomedullin and central haemodynamics in patients with mitral stenosis.
Methods—Plasma concentrations of adrenomedullin in blood samples obtained from the femoral vein, pulmonary artery, left atrium, and aorta were measured by a newly developed specific radioimmunoassay in 23 consecutive patients with mitral stenosis (16 females and seven males, aged 53 (10) years (mean (SD)) who were undergoing percutaneous mitral commissurotomy.
Results—Patients with mitral stenosis had higher concentrations of adrenomedullin than age matched normal controls (3.9 (0.3) v 2.5 (0.3) pmol/l, p < 0.001). There was a reduction in adrenomedullin concentrations between the pulmonary artery and the left atrium (3.8 (0.2) v 3.2 (0.4) pmol/l, p < 0.001). The venous concentrations of adrenomedullin correlated with mean pulmonary artery pressure (r = 0.65, p < 0.001), total pulmonary vascular resistance (r = 0.83, p < 0.0001), and pulmonary vascular resistance (r = 0.65, p < 0.001). Plasma concentrations of adrenomedullin did not change immediately after percutaneous mitral commissurotomy; however, they decreased significantly one week later.
Conclusions—Plasma concentrations of adrenomedullin are increased in patients with mitral stenosis. This may help to attenuate the increased pulmonary arterial resistance in secondary pulmonary hypertension due to mitral stenosis.

Keywords: adrenomedullin;  pulmonary hypertension;  mitral stenosis;  pulmonary circulation     

Transcatheter closure of fontan fenestrations using the Amplatzer septal occluder: initial experience and follow-up.

We have recently used the Amplatzer septal occluder to close Fontan fenestrations. Between June 1998 and December 1999, 13 patients underwent transcatheter occlusion of their Fontan fenestrations. Systemic blood flow decreased significantly without a concomitant decrease in pulmonary blood flow. All residual shunts detectable by oximetry were at sites separate from those into which occlusion devices were implanted. One patient developed severe tricuspid regurgitation following the procedure requiring surgical removal of the device. At the last follow-up, all patients were doing well clinically. There were no shunts detectable through or around the devices by echocardiography. Our experience indicates that the location of the fenestration within the Fontan baffle is critical to avoiding device interference with other intracardiac structures. The Amplatzer septal occluder offers an effective means of transcatheter closure of Fontan baffle fenestrations. Although more experience is needed, our current follow-up data suggest that long-term outcomes will be favorable. Cathet. Cardiovasc. Intervent. 51:301-304, 2000.     

Hybrid approach to pulmonary vein stenting after Fontan palliation

Pulmonary vein stenosis is poorly tolerated in patients who have undergone Fontan palliation and typically requires surgical or transcatheter intervention. Percutaneous transcatheter approaches to intervention can be technically difficult due to challenging anatomy. A hybrid per-atrial transcatheter approach for stenting pulmonary veins provides a direct approach to the pulmonary veins and has the potential to improve safety and efficacy of this complex intervention. We describe our experience with hybrid per-atrial pulmonary vein stenting in three patients with pulmonary vein stenosis following Fontan palliation.     

Results of three to 10 year follow up of balloon dilatation of the pulmonary valve

BACKGROUND: The results of immediate and short term follow up of balloon dilatation of the pulmonary valve have been well documented, but there is limited information on long term follow up. OBJECTIVE: To evaluate the results of three to 10 year follow up of balloon dilatation of the pulmonary valve in children and adolescents. SETTING: Tertiary care centre/university hospital. DESIGN: Retrospective study. METHODS AND RESULTS: 85 patients (aged between 1 day and 20 years, mean (SD) 7.0 (6.4) years) underwent balloon dilatation of the pulmonary valve during an 11 year period ending August 1994. There was a resultant reduction in the peak to peak gradient from 87 (38) to 26 (22) mm Hg. Immediate surgical intervention was not required. Residual gradients of 29 (17) mm Hg were measured by catheterisation (n = 47) and echo Doppler (n = 82) at intermediate term follow up (two years). When individual results were scrutinised, nine of 82 patients had restenosis, defined as a peak gradient of 50 mm Hg or more. Seven of these patients underwent repeat balloon dilatation of the pulmonary valve: peak gradients were reduced from 89 (40) to 38 (20) mm Hg. Clinical evaluation and echo Doppler data of 80 patients showed that residual peak instantaneous Doppler gradients were 17 (15) mm Hg at long term follow up (three to 10 years, median seven), with evidence for late restenosis in one patient (1.3%). Surgical intervention was necessary to relieve fixed infundibular stenosis in three patients and supravalvar pulmonary stenosis in one. Repeat balloon dilatation was performed to relieve restenosis in two patients. Actuarial reintervention free rates at one, two, five, and 10 years were 94%, 89%, 88%, and 84%, respectively. Pulmonary valve regurgitation was noted in 70 of 80 patients at late follow up, but neither right ventricular dilatation nor paradoxical interventricular septal motion developed. CONCLUSIONS: The results of late follow up of balloon dilatation of the pulmonary valve are excellent. Repeat balloon dilatation was performed in 11% of patients and surgical intervention for subvalvlar or supravalvar stenosis in 5%. Most patients had mild residual pulmonary regurgitation but right ventricular volume overload was not required. Balloon dilatation is the treatment of choice in the management of moderate to severe stenosis of the pulmonary valve. Further follow up studies should be undertaken to evaluate the significance of residual pulmonary regurgitation.     

Left‐sided Scimitar Vein Causing Cyanosis after Fontan Operation: Successful Transcatheter Device Occlusion Using Magnetic Resonance Imaging X‐ray Fusion

We present the case of a 3‐year‐old boy with asplenia‐type heterotaxy syndrome and functionally single ventricle congenital heart disease who developed cyanosis early after the Fontan operation. Combined cardiac magnetic resonance imaging (MRI) and catheterization identified a large hepatic vein to pulmonary vein connection as the source of right to left shunt. The anatomy was quite unusual, suggesting an underlying diagnosis of mixed total anomalous pulmonary venous connection with left‐sided scimitar vein. This pattern of pulmonary venous return has not been previously reported in a patient with asplenia. MRI x‐ray fusion was used to guide transcatheter device occlusion of the scimitar vein, resulting in marked clinical improvement.     

Intravascular stents: a new technique for tissue processing for histology, immunohistochemistry, and transmission electron microscopy

Background—Study of the vascular response to stent implantation has been hampered by difficulties in sectioning metal and tissue without distortion of the tissue stent interface. The metal is often removed before histochemical processing, causing a loss of arterial architecture. Histological and immunohistochemical sections should be 5 µm with an intact tissue stent interface.
Objectives—To identify the most suitable cutting and grinding equipment, embedding resin, and slides for producing thin sections of stented arteries with the stent wires in situ for histological, immunohistochemical, and transmission electron microscopic (TEM) analyses.
Methods—20 balloon stainless steel stents were implanted in the coronary arteries of 10 pigs. Twenty eight days later the stented arterial segments were excised, formalin fixed, embedded in five different resins (Epon 812, LR white, T9100, T8100, and JB4), and sectioned with two different high speed saws and a grinder for histological, immunohistochemical, and TEM analyses. Five stented human arteries were obtained at necropsy and processed using the best of the reported methods.
Results—The Isomet precision saw and grinder/polisher unit reliably produced 5 µm sections with most embedding resins; minimum section thickness with the horizontal saw was 400 µm. Resin T8100, a glycol methacrylate, enabled satisfactory sectioning, grinding, and histological (toluidine blue, haematoxylin and eosin, and trichromatic and polychromatic stains) and immunohistochemical analyses (α smooth muscle actin, von Willebrand factor, vimentin, proliferating cell nuclear antigen, and CD68 (mac 387)). T9100 and T8100 embedded stented sections were suitable for ultrastructural examination with TEM. Stented human arterial sections showed preserved arterial architecture with the struts in situ.
Conclusion—This study identified the optimal methods for embedding, sawing, grinding, and slide mounting of stented arteries to achieve 5 µm sections with an intact tissue metal interface, excellent surface qualities, histological and immunohistochemical staining properties, and suitability for TEM examination. The technique is applicable to experimental and clinical specimens.

Keywords: stents; resin; histology; immunohistochemistry; transmission electron microscopy     

Potential impact of antiarrhythmic drugs versus implantable defibrillators on the management of ventricular arrhythmias: the Midlands trial of empirical amiodarone versus electrophysiologically guided intervention and cardioverter implant registry data

Background—Survival was prolonged in selected patients with sustained ventricular arrhythmias who received implantable cardioverter defibrillators (ICDs) in the antiarrhythmics versus implantable defibrillators (AVID) study. The Midlands trial of empirical amiodarone versus electrophysiologically guided intervention and cardioverter implant in ventricular arrhythmias (MAVERIC) registry is a population based trial.
Objective—To determine the number of patients who satisfy the AVID criteria because of the high cost of ICDs.
Design—Observational study, based on a continuing trial.
Setting—All coronary care units in the Midlands region in the United Kingdom (population 9.1 million).
Patients—Patients presenting to a coronary care unit with sustained ventricular arrhythmias not related to an acute myocardial infarction are entered onto the registry. Those who consent to the MAVERIC study are randomised to receive either empirical amiodarone or electrophysiologically guided treatment. Demographic data, details of clinical presentation, and echocardiographic findings are collected. These data have been used to calculate the number of patients who satisfy the AVID criteria and would benefit from ICD implantation. The financial implications have been calculated for the region and nationally.
Results—132 patients were entered onto the registry during the first five months of the MAVERIC study; 69 patients fulfilled the AVID criteria. Extrapolation of these data over a 12 month period suggests implantation of at least 166 new ICDs (compared with 23 implants in 1996). This would increase the UK ICD implant rate from five to at least 18 per million of the population, costing the National Health Service £24.1 million per annum.
Conclusion—Application of the AVID criteria in the UK will cause a great increase in the ICD implant rate, with serious financial implications.

Keywords: AVID study;  MAVERIC trial;  implantable cardioverter defibrillator;  economics;  arrhythmias