Catheterization and Cardiovascular Interventions 86:100–104 (2015)
Long-Term Follow-up is Not Indicated After Routine Interventional Closure of Persistent Arterial Ducts Srinivas A. Narayan, MD, Elfadil Elmahdi, MD, Eric Rosenthal, MD, FRCP, Shakeel A. Qureshi, MBChB, FRCP, FRCPCH, and Thomas Krasemann,* MD(D) FRCP Background: Little is known about the necessity for long-term follow-up after interventional closure of persistent arterial duct (PDA). Potential side effects and complications include residual shunts, haemolysis, device embolization, and obstruction to flow in the adjoining vessels. Methods: Single centre retrospective study of paediatric patients undergoing interventional PDA occlusion. Results: 315 patients who underwent interventional occlusion of a PDA between November 2002 and September 2013 were included. Of these, eight needed re-intervention (three for device embolization, five for residual shunt). Seven had mild obstruction to flow in the adjoining vessels, but did not require any intervention. All sequelae were found latest at the first followup appointment after the procedure (usually within 3 months); whilst none developed during further follow-up. Conclusion: Complications of interventional closure of PDA were apparent immediately after the procedure or by three months of follow-up. Longterm follow-up is not indicated in cases when no complications are seen early after the procedure. VC 2015 Wiley Periodicals, Inc. Key words: pediatric intervention; closure; ASD/PDA/PFO; structural heart disease intervention
INTRODUCTION
METHODS
Percutaneous occlusion of a patent ductus arteriosus (PDA) with coils or occlusive devices is effective and the method of choice outside the neonatal period [1–3]. Potential adverse effects of the intervention include device-related obstruction to flow in the left or right pulmonary arteries or descending aorta, persistent shunting past the device with potential subsequent haemolysis, and device migration. Current practice after catheter occlusion of a PDA is echocardiography to confirm the effect of the procedure, to look for a residual shunt and obstruction to the adjoining vessels. In most centres this is followed by regular echocardiograms for surveillance of potential sequelae. Although there is extensive literature on the different types of occlusive devices and the immediate results [1], to our knowledge, there are currently no large scale studies looking at the length of follow-up required to survey these patients. This study aims to ascertain the following: (1) if there are immediate complications, do they resolve during follow-up? (2) If there are no immediate complications/vessel obstructions, do they develop during follow-up? (3) If not, do patients need long term follow-up?
Patients who underwent percutaneous closure of a PDA between November 2002 and September 2013 were identified from the departmental database (HeartC , Systeria, Glasgow, UK). Patients excluded SuiteV from this study were those older than 16 years at the time of the procedure, those with additional congenital cardiac disease requiring long term follow-up, preexisting flow disturbances in the aorta or branch pulmonary arteries, those that required surgical ligation of the PDA following percutaneous intervention, and death not related to the procedure.
C 2015 Wiley Periodicals, Inc. V
Department of Paediatric Cardiology, Evelina Children’s Hospital, London, United Kingdom Conflict of interest: Nothing to report. *Correspondence to: Thomas Krasemann, MD (D) FRCP, Evelina Children’s Hospital, Department of Paediatric Cardiology, Westminster Bridge Road, London SE1 7EH, United Kingdom. E-mail: [email protected] Received 27 September 2014; Revision accepted 26 February 2015 DOI: 10.1002/ccd.25912 Published online 2 April 2015 in Wiley Online Library (wileyonlinelibrary.com)
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TABLE I. Demographic Characteristics n Included patients Total Procedures Weight at procedure (mean SD) kg Age at procedure [Mean SD (days)] Occlusion device ADO I ADO II Cera (Lifetech) Nit-Occlud-R Occlutech PDA Coil Total
315 323 14.03 9.38 1064.46 1021.79 129 (39.93%) 5 (1.5%) 17 (5.2%) 3 (0.9%) 4 (1.2%) 165 (49.84%) 323 (Procedures)
Fig. 1. Distribution of Patients (FU 5 Follow-up, CHD 5 Congenital Heart Disease).
Patient details included age and weight at the time of the procedure and post procedural and follow-up echocardiography with specific attention to residual duct flow and obstruction to the adjoining vessels, and potential haemolysis. The recommended follow-up intervals for these patients were 2–3 months, 6 months and 12 months after the ductal closure and yearly or biannually thereafter. Colour-flow echocardiograms were performed at each of these visits. Timing of discharge of patients was at the discretion of the attending physician. Follow-up data available up to 10/06/2014 were included in the analysis. Descriptive statistics were used.
RESULTS
Four hundred and thirty patients (with 438 procedures) were identified in whom interventional PDA closure was attempted in the specified time period. Patients excluded from analysis were 43 older than 16 years at the time of the procedure, and 71 with addi-
212 Females (65.6%)
Residual shunt (n) 11 1 0 1 0 15
111 Males (34.3%)
Stenosis of adjoining vessels (n) 2 0 1 0 0 4
tional congenital heart defects requiring on-going follow-up. 1 patient died from conditions unrelated to the procedure. 315 patients (with 323 procedures) were included in the analysis (Table I). Ninety-two patients (with 94 procedures) are still under follow-up. Further 122 patients (128 procedures) were discharged from follow-up. In 101 patients data on follow-up data was incomplete, as they were followed up in other centres (Fig. 1). In the discharged patients, the duct was occluded with coils (Cook Medical Inc., Bloomington IN, USA—68 procedures) ranging from 3 4 to 8 6 mm, with Amplatzer duct occluders (ADO) (St. Jude Medical, St. Paul MN, USA—49 procedures) ranging from 3 4 to 16 14 mm, and with Cera devices (Lifetech Scientific, Shenzhen, China—10 procedures) ranging from 4 6 to 12 10 mm, and in one patient with a NIT-Occlud PDA-R of 5.5 mm (PFM Medical AG, Cologne, Germany). The mean follow-up time of discharged patients was 25.88 months (27.35, range 0.39–135 months). Mean age and weight of patients at the time of intervention was 38.66 (36.34) months and 14.63 (9.48) kg. The mean follow-up of patients who are still under follow-up was 69.6 months (29.31, range 9.56– 127.87 months). The mean age and weight at the time of intervention were 30.7(27.44) months and 12.6(5.64) kg. Residual Shunt
Residual shunts were found after 28 procedures (8.9%) on echocardiography at the time of discharge, within 24 hr of the procedure. In all of these patients, this was described qualitatively as “tiny or trivial residual leak.” There were a nearly equal number of patients with coils (15 cases) and devices (13 cases). In seven of these patients, follow-up data could not be specified due to incomplete records. In five cases, re-intervention was needed to close the residual leak,
Catheterization and Cardiovascular Interventions DOI 10.1002/ccd. Published on behalf of The Society for Cardiovascular Angiography and Interventions (SCAI).
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the details of which are described below. In all other patients (sixteen patients) the residual leak was resolved by the time of the first appointment. The mean follow-up time for the first outpatient appointment was 3.0 (3.1) months after intervention. The mean age of patients with residual leaks patient age at the time of the intervention was 22.86 (20.71) months. The mean weight was 10.85 (4.95) kg. We did not encounter any haemolysis in any of our patients.
Flow Acceleration in the Adjoining Vessels Seven (2.2%) patients were found to have device related flow acceleration on Doppler-echocardiography in one of the adjoining vessels after the procedure indicating stenosis. In these, the PDA was occluded with coils in four and devices in three. Flow acceleration in the descending aorta occurred in four patients. In one patient after insertion of ADO I, the flow velocity in descending aorta was around 2.5 m/sec and did not change during three follow-up appointments. There was no diastolic tail on conventional Doppler. Another patient with ADO I developed a mild increase in flow across the descending aorta (1.9 m/s), again without any diastolic tail. These two patients are still under follow-up. The flow velocity in the descending aorta in a patient in whom the PDA R device was 2 m/s. This norwas closed with a CeraV malized by the second follow-up and he was subsequently discharged. In another patient (with a Cook Coil to close the PDA), there was a mild flow acceleration post procedure in the aorta and LPA, which subsided after nearly 6 years, and the patient was then discharged. In three further patients, there was flow acceleration within the LPA. The flow velocity during the first appointment after intervention ranged from 1.8 m/s to 2.6 m/s. One of these patients has been discharged as the gradient decreased to acceptable limits within a year. Another patient continues to be under follow-up. Information on follow-up was not available for the third patient. Flow acceleration did not worsen in any patient.
Re-Intervention
Eight patients (2.5%) required catheter re-intervention: Five were due to residual shunt following the initial catheterisation and the remaining three were due to device embolization. One additional patient needed surgery to retrieve the device, which had embolized to the RPA. Her PDA was surgically ligated during the same
procedure. This patient has been excluded from the study as her PDA closure was performed surgically. The three cases of embolization initially had Cook coils, which embolized within 24 hours. The coils were retrieved and ADOs were placed. One of these cases was published previously [4]. In one of the cases with residual shunt, the direct cause of the residual shunt was an ADO II device used. This device was initially position correctly, but tilted over time and eventually caused stenting of the duct resulting in substantial shunt, which was then treated with an additional ADO I device [5,6]. In the remaining four patients who were treated with Cook coils, the residual shunt was described as “small leak” immediately after the procedure and confirmed on first follow-up. All of these were occluded with additional coils. The mean weight and age of the patients who underwent closure of a duct and subsequently needed a second catheter intervention was 11 (3.0) kg and 27.2 (13.9) months, respectively. DISCUSSION
Follow-up after cardiac catheter interventions should be guided by potential late complications or pathology created by the intervention, or by potential changes of the heart disease itself. Data regarding the need for long term follow-up after interventional occlusion of PDA’s is scarce. It is unknown if follow-up is indicated, if there was either a residual shunt or any stenosis of the adjoining vessels after the procedure. In our study, only seven (2.2%) out of 315 had flow acceleration in one of the adjoining vessels post procedurally. None of these were significant enough to require any additional intervention. The vessel stenosis was noted in all cases latest during the first outpatient appointment, but never developed at any later stage. Residual shunts were rare too, and again were seen immediately. None occurred late after the procedure. Daniels et al. reported in 1998 five cases of “reopening of the PDA” after complete closure was confirmed initially by Doppler Echocardiography [7]. Their patients were assessed echocardiographically as late as 12 months after closure. In addition, they used coils as the only occlusion devices. Their article highlights the need for one post-interventional assessment, but the timing can be discussed. In our study, the first follow-up was routinely within the first 3 months after intervention. Anyhow, some authors doubt the predictive value of an immediate echocardiographical assessment after coil occlusion of a PDA [8]. Recanalization of an occluded PDA was not reported in other case series, too [9].
Catheterization and Cardiovascular Interventions DOI 10.1002/ccd. Published on behalf of The Society for Cardiovascular Angiography and Interventions (SCAI).
Routine Interventional Closure of PDA
Fig. 2. Proposed Protocol for follow-up post PDA occlusion.
Turner et al. have also reported PDA re-opening rate of 5% at six months after PDA occlusion in their study [8]. They have suggested that PDA recanalization does not occur if complete echocardiographic closure is documented 6 months after coil occlusion. Their paper does not report any follow-up data earlier than 6 months after the procedure. In our study, the first follow-up was around 3 months after intervention, but we come to the same conclusion: If the echocardiogram is normal (except for the PDA occlusion device/ coil) at the first post interventional clinic visit, no further follow-up is necessary. Patients who had a normal echocardiogram (apart from the device) after duct occlusion continued to do so during all follow-up appointments. No pathology developed at any later stage. This confirms the result of a smaller study of Park et al. [2]. Interestingly, Sreeram et al. suggested that the use of echocardiogram was an unreliable screening method for decreased flow in left pulmonary artery, and that its stenosis is a rare complication especially with the use of multiple coils [6]. We did not use additional imaging modalities or invasive catheterization for follow-up in any of our patients.
103
In 1996 small residual shunts were found in up to 40% [10]. Carey et al. concluded that minor residual flow following occlusion is common and not significant 7. In our series the rate of residual shunt was just 9% (28 out of 315), and more than three quarters of these resolved completely. Out of the eight patients requiring re-catheterisation, three were carried out within the first three days following the initial catheterization; this was due to device migration occurring within 24 hr. This is a known complication of percutaneous duct occlusion [1]. In the remaining five, residual shunts were treated as described above. Some workgroups identified the type of coil used for PDA-occlusion as a risk factor for residual shunts, while others used the same coils successfully [11]. Agnetti et al. found persistent minor shunts in 8.37% of patients on post procedural discharge echo, this dropped to fewer than 6% of patients by the time of the first follow-up appointment. In our patients, most shunts were not detectable anymore on echocardiography at the first follow-up appointment. In one of our patients, an additional coil was implanted years after the initial procedure. In this patient the residual shunt was thought to be negligible, but as the patient required a pacemaker for complete congenital heart block, the residual PDA was closed during this procedure. It would have been left alone if no other procedure had have been carried out. In another patient an ADO II was used which resulted in the contradictory stenting of the PDA and later required closure with an Amplatzer device type I [5]. The ADO II is a relatively new device for treatment of PDA’s and is not as widely used as i.e. the ADO I. In our series, the majority of percutaneous PDA occlusions were performed with either coils or ADO I devices (or comparable devices from other manufacturers). Carey et al. (1996) found in one out of 25 patients some flow acceleration in one of the adjoining vessels, but none of their patients needed re-intervention [10]. This article also showed that minor flow disturbances in aorta and left pulmonary artery resolve with time [10]. Nevertheless, they suggested long-term follow-up of these patients. Sreeram et al. (1999) found that 3 months after interventional ductal closure with coils, one of 35 patients had decreased left lung blood flow on lung perfusions studies (
Long-Term Follow-up is Not Indicated After Routine Interventional Closure of Persistent Arterial Ducts Srinivas A. Narayan, MD, Elfadil Elmahdi, MD, Eric Rosenthal, MD, FRCP, Shakeel A. Qureshi, MBChB, FRCP, FRCPCH, and Thomas Krasemann,* MD(D) FRCP Background: Little is known about the necessity for long-term follow-up after interventional closure of persistent arterial duct (PDA). Potential side effects and complications include residual shunts, haemolysis, device embolization, and obstruction to flow in the adjoining vessels. Methods: Single centre retrospective study of paediatric patients undergoing interventional PDA occlusion. Results: 315 patients who underwent interventional occlusion of a PDA between November 2002 and September 2013 were included. Of these, eight needed re-intervention (three for device embolization, five for residual shunt). Seven had mild obstruction to flow in the adjoining vessels, but did not require any intervention. All sequelae were found latest at the first followup appointment after the procedure (usually within 3 months); whilst none developed during further follow-up. Conclusion: Complications of interventional closure of PDA were apparent immediately after the procedure or by three months of follow-up. Longterm follow-up is not indicated in cases when no complications are seen early after the procedure. VC 2015 Wiley Periodicals, Inc. Key words: pediatric intervention; closure; ASD/PDA/PFO; structural heart disease intervention
INTRODUCTION
METHODS
Percutaneous occlusion of a patent ductus arteriosus (PDA) with coils or occlusive devices is effective and the method of choice outside the neonatal period [1–3]. Potential adverse effects of the intervention include device-related obstruction to flow in the left or right pulmonary arteries or descending aorta, persistent shunting past the device with potential subsequent haemolysis, and device migration. Current practice after catheter occlusion of a PDA is echocardiography to confirm the effect of the procedure, to look for a residual shunt and obstruction to the adjoining vessels. In most centres this is followed by regular echocardiograms for surveillance of potential sequelae. Although there is extensive literature on the different types of occlusive devices and the immediate results [1], to our knowledge, there are currently no large scale studies looking at the length of follow-up required to survey these patients. This study aims to ascertain the following: (1) if there are immediate complications, do they resolve during follow-up? (2) If there are no immediate complications/vessel obstructions, do they develop during follow-up? (3) If not, do patients need long term follow-up?
Patients who underwent percutaneous closure of a PDA between November 2002 and September 2013 were identified from the departmental database (HeartC , Systeria, Glasgow, UK). Patients excluded SuiteV from this study were those older than 16 years at the time of the procedure, those with additional congenital cardiac disease requiring long term follow-up, preexisting flow disturbances in the aorta or branch pulmonary arteries, those that required surgical ligation of the PDA following percutaneous intervention, and death not related to the procedure.
C 2015 Wiley Periodicals, Inc. V
Department of Paediatric Cardiology, Evelina Children’s Hospital, London, United Kingdom Conflict of interest: Nothing to report. *Correspondence to: Thomas Krasemann, MD (D) FRCP, Evelina Children’s Hospital, Department of Paediatric Cardiology, Westminster Bridge Road, London SE1 7EH, United Kingdom. E-mail: [email protected] Received 27 September 2014; Revision accepted 26 February 2015 DOI: 10.1002/ccd.25912 Published online 2 April 2015 in Wiley Online Library (wileyonlinelibrary.com)
Routine Interventional Closure of PDA
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TABLE I. Demographic Characteristics n Included patients Total Procedures Weight at procedure (mean SD) kg Age at procedure [Mean SD (days)] Occlusion device ADO I ADO II Cera (Lifetech) Nit-Occlud-R Occlutech PDA Coil Total
315 323 14.03 9.38 1064.46 1021.79 129 (39.93%) 5 (1.5%) 17 (5.2%) 3 (0.9%) 4 (1.2%) 165 (49.84%) 323 (Procedures)
Fig. 1. Distribution of Patients (FU 5 Follow-up, CHD 5 Congenital Heart Disease).
Patient details included age and weight at the time of the procedure and post procedural and follow-up echocardiography with specific attention to residual duct flow and obstruction to the adjoining vessels, and potential haemolysis. The recommended follow-up intervals for these patients were 2–3 months, 6 months and 12 months after the ductal closure and yearly or biannually thereafter. Colour-flow echocardiograms were performed at each of these visits. Timing of discharge of patients was at the discretion of the attending physician. Follow-up data available up to 10/06/2014 were included in the analysis. Descriptive statistics were used.
RESULTS
Four hundred and thirty patients (with 438 procedures) were identified in whom interventional PDA closure was attempted in the specified time period. Patients excluded from analysis were 43 older than 16 years at the time of the procedure, and 71 with addi-
212 Females (65.6%)
Residual shunt (n) 11 1 0 1 0 15
111 Males (34.3%)
Stenosis of adjoining vessels (n) 2 0 1 0 0 4
tional congenital heart defects requiring on-going follow-up. 1 patient died from conditions unrelated to the procedure. 315 patients (with 323 procedures) were included in the analysis (Table I). Ninety-two patients (with 94 procedures) are still under follow-up. Further 122 patients (128 procedures) were discharged from follow-up. In 101 patients data on follow-up data was incomplete, as they were followed up in other centres (Fig. 1). In the discharged patients, the duct was occluded with coils (Cook Medical Inc., Bloomington IN, USA—68 procedures) ranging from 3 4 to 8 6 mm, with Amplatzer duct occluders (ADO) (St. Jude Medical, St. Paul MN, USA—49 procedures) ranging from 3 4 to 16 14 mm, and with Cera devices (Lifetech Scientific, Shenzhen, China—10 procedures) ranging from 4 6 to 12 10 mm, and in one patient with a NIT-Occlud PDA-R of 5.5 mm (PFM Medical AG, Cologne, Germany). The mean follow-up time of discharged patients was 25.88 months (27.35, range 0.39–135 months). Mean age and weight of patients at the time of intervention was 38.66 (36.34) months and 14.63 (9.48) kg. The mean follow-up of patients who are still under follow-up was 69.6 months (29.31, range 9.56– 127.87 months). The mean age and weight at the time of intervention were 30.7(27.44) months and 12.6(5.64) kg. Residual Shunt
Residual shunts were found after 28 procedures (8.9%) on echocardiography at the time of discharge, within 24 hr of the procedure. In all of these patients, this was described qualitatively as “tiny or trivial residual leak.” There were a nearly equal number of patients with coils (15 cases) and devices (13 cases). In seven of these patients, follow-up data could not be specified due to incomplete records. In five cases, re-intervention was needed to close the residual leak,
Catheterization and Cardiovascular Interventions DOI 10.1002/ccd. Published on behalf of The Society for Cardiovascular Angiography and Interventions (SCAI).
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the details of which are described below. In all other patients (sixteen patients) the residual leak was resolved by the time of the first appointment. The mean follow-up time for the first outpatient appointment was 3.0 (3.1) months after intervention. The mean age of patients with residual leaks patient age at the time of the intervention was 22.86 (20.71) months. The mean weight was 10.85 (4.95) kg. We did not encounter any haemolysis in any of our patients.
Flow Acceleration in the Adjoining Vessels Seven (2.2%) patients were found to have device related flow acceleration on Doppler-echocardiography in one of the adjoining vessels after the procedure indicating stenosis. In these, the PDA was occluded with coils in four and devices in three. Flow acceleration in the descending aorta occurred in four patients. In one patient after insertion of ADO I, the flow velocity in descending aorta was around 2.5 m/sec and did not change during three follow-up appointments. There was no diastolic tail on conventional Doppler. Another patient with ADO I developed a mild increase in flow across the descending aorta (1.9 m/s), again without any diastolic tail. These two patients are still under follow-up. The flow velocity in the descending aorta in a patient in whom the PDA R device was 2 m/s. This norwas closed with a CeraV malized by the second follow-up and he was subsequently discharged. In another patient (with a Cook Coil to close the PDA), there was a mild flow acceleration post procedure in the aorta and LPA, which subsided after nearly 6 years, and the patient was then discharged. In three further patients, there was flow acceleration within the LPA. The flow velocity during the first appointment after intervention ranged from 1.8 m/s to 2.6 m/s. One of these patients has been discharged as the gradient decreased to acceptable limits within a year. Another patient continues to be under follow-up. Information on follow-up was not available for the third patient. Flow acceleration did not worsen in any patient.
Re-Intervention
Eight patients (2.5%) required catheter re-intervention: Five were due to residual shunt following the initial catheterisation and the remaining three were due to device embolization. One additional patient needed surgery to retrieve the device, which had embolized to the RPA. Her PDA was surgically ligated during the same
procedure. This patient has been excluded from the study as her PDA closure was performed surgically. The three cases of embolization initially had Cook coils, which embolized within 24 hours. The coils were retrieved and ADOs were placed. One of these cases was published previously [4]. In one of the cases with residual shunt, the direct cause of the residual shunt was an ADO II device used. This device was initially position correctly, but tilted over time and eventually caused stenting of the duct resulting in substantial shunt, which was then treated with an additional ADO I device [5,6]. In the remaining four patients who were treated with Cook coils, the residual shunt was described as “small leak” immediately after the procedure and confirmed on first follow-up. All of these were occluded with additional coils. The mean weight and age of the patients who underwent closure of a duct and subsequently needed a second catheter intervention was 11 (3.0) kg and 27.2 (13.9) months, respectively. DISCUSSION
Follow-up after cardiac catheter interventions should be guided by potential late complications or pathology created by the intervention, or by potential changes of the heart disease itself. Data regarding the need for long term follow-up after interventional occlusion of PDA’s is scarce. It is unknown if follow-up is indicated, if there was either a residual shunt or any stenosis of the adjoining vessels after the procedure. In our study, only seven (2.2%) out of 315 had flow acceleration in one of the adjoining vessels post procedurally. None of these were significant enough to require any additional intervention. The vessel stenosis was noted in all cases latest during the first outpatient appointment, but never developed at any later stage. Residual shunts were rare too, and again were seen immediately. None occurred late after the procedure. Daniels et al. reported in 1998 five cases of “reopening of the PDA” after complete closure was confirmed initially by Doppler Echocardiography [7]. Their patients were assessed echocardiographically as late as 12 months after closure. In addition, they used coils as the only occlusion devices. Their article highlights the need for one post-interventional assessment, but the timing can be discussed. In our study, the first follow-up was routinely within the first 3 months after intervention. Anyhow, some authors doubt the predictive value of an immediate echocardiographical assessment after coil occlusion of a PDA [8]. Recanalization of an occluded PDA was not reported in other case series, too [9].
Catheterization and Cardiovascular Interventions DOI 10.1002/ccd. Published on behalf of The Society for Cardiovascular Angiography and Interventions (SCAI).
Routine Interventional Closure of PDA
Fig. 2. Proposed Protocol for follow-up post PDA occlusion.
Turner et al. have also reported PDA re-opening rate of 5% at six months after PDA occlusion in their study [8]. They have suggested that PDA recanalization does not occur if complete echocardiographic closure is documented 6 months after coil occlusion. Their paper does not report any follow-up data earlier than 6 months after the procedure. In our study, the first follow-up was around 3 months after intervention, but we come to the same conclusion: If the echocardiogram is normal (except for the PDA occlusion device/ coil) at the first post interventional clinic visit, no further follow-up is necessary. Patients who had a normal echocardiogram (apart from the device) after duct occlusion continued to do so during all follow-up appointments. No pathology developed at any later stage. This confirms the result of a smaller study of Park et al. [2]. Interestingly, Sreeram et al. suggested that the use of echocardiogram was an unreliable screening method for decreased flow in left pulmonary artery, and that its stenosis is a rare complication especially with the use of multiple coils [6]. We did not use additional imaging modalities or invasive catheterization for follow-up in any of our patients.
103
In 1996 small residual shunts were found in up to 40% [10]. Carey et al. concluded that minor residual flow following occlusion is common and not significant 7. In our series the rate of residual shunt was just 9% (28 out of 315), and more than three quarters of these resolved completely. Out of the eight patients requiring re-catheterisation, three were carried out within the first three days following the initial catheterization; this was due to device migration occurring within 24 hr. This is a known complication of percutaneous duct occlusion [1]. In the remaining five, residual shunts were treated as described above. Some workgroups identified the type of coil used for PDA-occlusion as a risk factor for residual shunts, while others used the same coils successfully [11]. Agnetti et al. found persistent minor shunts in 8.37% of patients on post procedural discharge echo, this dropped to fewer than 6% of patients by the time of the first follow-up appointment. In our patients, most shunts were not detectable anymore on echocardiography at the first follow-up appointment. In one of our patients, an additional coil was implanted years after the initial procedure. In this patient the residual shunt was thought to be negligible, but as the patient required a pacemaker for complete congenital heart block, the residual PDA was closed during this procedure. It would have been left alone if no other procedure had have been carried out. In another patient an ADO II was used which resulted in the contradictory stenting of the PDA and later required closure with an Amplatzer device type I [5]. The ADO II is a relatively new device for treatment of PDA’s and is not as widely used as i.e. the ADO I. In our series, the majority of percutaneous PDA occlusions were performed with either coils or ADO I devices (or comparable devices from other manufacturers). Carey et al. (1996) found in one out of 25 patients some flow acceleration in one of the adjoining vessels, but none of their patients needed re-intervention [10]. This article also showed that minor flow disturbances in aorta and left pulmonary artery resolve with time [10]. Nevertheless, they suggested long-term follow-up of these patients. Sreeram et al. (1999) found that 3 months after interventional ductal closure with coils, one of 35 patients had decreased left lung blood flow on lung perfusions studies (
