Catheterization and Cardiovascular Interventions 00:00–00 (2014)
Original Studies A Novel Technique for Transcatheter Patent Ductus Arteriosus Closure in Extremely Preterm Infants Using Commercially Available Technology Evan M. Zahn,1,3* MD, Phillip Nevin,3 RN, Charles Simmons,2 MD, and Ruchira Garg,1,3 MD Objectives: To describe a new technique for transcatheter patent ductus arteriosus (PDA) closure in extremely preterm infants using commercially available technology. Background: PDA in premature neonates continues to be a significant clinical problem contributing importantly to both morbidity and mortality. Surgical ligation and medical therapy both have their drawbacks. Material and Methods: Hospital records and catheterization reports of all premature neonates (< 32 weeks gestation) who underwent transcatheter PDA closure between March 2013 and February 2014 were reviewed. Particular attention was paid to procedural details, complications, and short and mid-term outcomes. Results: Six premature infants born at gestational ages ranging between 26 and 31 weeks (median, 26 weeks) underwent attempted transcatheter PDA closure using the Amplatzer Vascular Plug II (AVP II). Median age and weight was 21.5 days (16–80 days) and 1,180 g (870–2,240 g), respectively. Fluoroscopy and echocardiography were used to guide device. Contrast angiography was not used in any patient. Complete closure was achieved in all patients with no major procedural complications. Median fluoroscopy and procedural times were 9.4 (0–19.5) and 51.5 (33–87) min, respectively. All patients were alive at the time of this report. There were no instances of device migration, left pulmonary artery (LPA), or aortic coarctation. Conclusions: This preliminary study demonstrates that transcatheter PDA closure can be successfully performed in extremely preterm neonates using currently available technology with a high success rate and a low incidence of complications. This report also describes a novel transvenous approach using a combination of echocardiography and judicious use of fluoroscopy to avoid arterial access in this fragile patient population. VC 2014 Wiley Periodicals, Inc. Key words: congenital heart disease; vascular occlusion 1
INTRODUCTION
For more than three decades it has been known that the presence of a hemodynamically significant patent ductus arteriosus (PDA) in preterm infants increases morbidity and mortality [1–6]. To date, available treatment options have been essentially limited to medical treatment with cyclooxygenase (COX) inhibitors or surgical ligation. The former is effective in 50–70% of cases and has been associated with major adverse effects including permanent alterations in renal function, necrotizing enterocolitis, gastrointestinal perforation, and impairment of cerebral blood flow velocity [7–9]. C 2014 Wiley Periodicals, Inc. V
The Division of Pediatric Cardiology, Department of Pediatrics, Cedars Sinai Medical Center, Los Angeles, California 2 The Division of Neonatology, Department of Pediatrics, Cedars Sinai Medical Center, Los Angeles, California 3 The Heart Institute, Cedars Sinai Medical Center, Los Angeles, California Conflict of interest: Nothing to report. *Correspondence to: Evan Zahn, MD, FACC, FSCAI, 127 S. San Vicente Blvd, Suite A3600, Los Angeles, CA 90048. E-mail: [email protected] Received 19 February 2014; Revision accepted 28 April 2014 DOI: 10.1002/ccd.25534 Published online 00 Month 2014 in Wiley Online Library (wileyonlinelibrary.com)
2
Zahn et al.
tain to this procedure include excellent fluoroscopic and echocardiographic visibility, ability to reposition/ remove multiple times as needed, relatively short length (3–6 mm diameter devices have an unconstrained length of 6 mm), deliverable through a 4 Fr sheath, relatively thin and soft delivery cable, and rapid vascular occlusion. The manufacturer recommends choosing a plug with a diameter at least 20% larger than the target vessel. Importantly for the current application, the final length of the deployed device is dependent on the degree of oversizing, i.e. the more over-sized the device (more constrained) the greater the implanted length will be.
Fig. 1. Commercially available Amplatzer Vascular Plug II. The small diameters and lengths of this device, easy deliverability, and excellent fluoroscopic and echocardiographic features of this device are attributes desirable in a PDA device in small neonates.
Surgical ligation involves a limited left thoracotomy or a “less-invasive” thorascopic approach and is successful in nearly all cases but is typically reserved for patients who fail medical therapy and has been associated with significant complications including pneumothorax, hypothermia, bleeding, phrenic nerve palsy, wound infection, vocal cord paralysis, and thoracic scoliosis [10–13]. While surgical PDA ligation is more effective than medical therapy, it has not been shown to positively impact survival of the severely premature infant [14]. Transcatheter PDA closure was first described nearly four decades ago [15] and has become the procedure of choice for infants > 5 kg, children, and adults. While several devices have been used for this purpose in older children, they are not routinely used in small infants, much less premature very low birth weight neonates. Our recognition of the morbidities related to surgical ductal ligation coupled with our experience with the commercially available Amplatzer vascular plug II (AVP II) prompted our group to assess the safety and efficacy of using this device to close PDAs in severely premature neonates. MATERIAL AND METHODS Device Description The AVP II (St Jude Medical, Minneapolis, MN) is a densely woven, self-expanding nitinol plug composed of two layers of 144 braided nitinol wires constructed as two outer disks and a central plug of equal diameter (Fig. 1). Some advantages of this device as they per-
Procedural Details All cases were performed under general anesthesia with endotracheal intubation after appropriate informed consent was obtained. Prior to gaining vascular access and throughout the case, high parasternal transthoracic echocardiographic images delineating the PDA anatomy were obtained, using a Phillips iE33 ultrasound machine with a 12S transducer. Measurements were made of the ductal length and diameters (Fig. 2). Device diameter size was chosen at least 1 mm larger than the narrowest diameter of the ductus similar to what has been described in older infants and children [16]. The first case (the largest patient in the series) was performed at the bedside in the neonatal intensive care unit using a retrograde arterial approach and transthoracic echocardiographic guidance as previously described by Bentham et al [17]. The remaining cases were performed in a digital FPD biplane catheterization suite (GE Innova, Milwaukee, WI) using the lowest possible fluoroscopy settings. Attention was paid to maintaining body core temperature in the normal range throughout the procedure. A 4 Fr introducer sheath (Daig, St Jude Medical, Minnetonka, MN) was placed in the right femoral vein using a 21-gauge butterfly needle, floppy tipped 0.018 guide wire (Micropuncture set, Cook Inc, Bloomington, IN) and standard Seldinger technique. Intravenous heparin (100 mg/kg) and prophylactic antibiotics (Cefazolin, 20 mg/kg) were administered in all cases and activated clotting time monitored and maintained between 200 and 250 sec. Under fluoroscopic guidance, a 4 Fr balloon wedge catheter (Arrow International, Reading, PA) was advanced to the mid-right atrium, the balloon inflated and the stiff end of a 0.018 standard guide wire (Cordis, Miami Lakes, FL) which had been shaped into a tight curve was advanced to the tip so as to direct the catheter toward the tricuspid valve. This minimized catheter manipulation in the
Catheterization and Cardiovascular Interventions DOI 10.1002/ccd. Published on behalf of The Society for Cardiovascular Angiography and Interventions (SCAI).
Transcatheter PDA Closure in Premature Infants
3
Fig. 2. Two-dimensional transthoracic images of the pertinent anatomy obtained form the high left parasternal position. The diameter of the PDA (*) as well as the length (B) of the vessel from the pulmonary artery (PA) to descending aorta (DscAo) is shown prior to device selection. The narrowest diameter of the PDA in this patient was 2.06 mm prompting selection of a 3 mm AVPII for the closure. [Color figure can be viewed in the online issue, which is available at wileyonlinelibrary.com.]
right atrium and allowed consistent passage of the catheter into the right ventricle where it uniformly passed easily into the main pulmonary artery as the guide wire was removed. The balloon was deflated in the main pulmonary artery and a 0.014 floppy tipped coronary guide wire (Hi-torque ALL STAR, Abbott Vascular, Santa Clara, CA) with a “hockey stick” curve placed on the tip was advanced through the catheter across the PDA, down the descending aorta and into a femoral artery. The balloon end-hole catheter and introducer sheath was removed and replaced with a 4 Fr long hydrophilic sheath (Flexor Check Flo Introducer 4 Fr 45 cm, Cook Inc, Bloomington, IN), which was advanced through the right heart, across the PDA into the descending aorta. Gentle external pressure over the femoral artery where the tip of the coronary guide wire was located was used in selected cases to stabilize the guide wire and provide the stability of a veno-arterial wire rail system (without exteriorizing the wire) for passage of the long sheath. After removing the dilator and guide wire from the delivery sheath, transthoracic echocardiographic images of the ductal region and appropriate anatomy including the paraductal descending aorta and origin of the left pulmo-
nary artery (LPA) were obtained and used to guide device placement (Fig. 3). An AVP II (St Jude Medical, Minnetonka, MN) was used for PDA closure in all cases. The device was prepared in the standard fashion and advanced to the tip of the delivery sheath under fluoroscopic guidance. The sheath was brought back to the aortic end of the PDA before deploying the distal disk. Efforts were made to deploy the aortic disk directly into the aortic ampulla of the ductus. Slow controlled traction on the sheath resulted in deployment of the remaining central portion and pulmonary end of the device into the PDA. Again, efforts were made to deploy as much of the device into the actual ductus and leave as little in the main pulmonary artery as possible. A detailed echocardiographic assessment including color and spectral analysis of flow in the PDA, left pulmonary artery, and descending aorta were made prior to releasing the device from the delivery cable. When concern arose regarding obstruction of flow into the left pulmonary artery or descending aorta, the device was repositioned using either gentle traction (aortic obstruction) or partial recapture of the proximal device with redeployment in a slightly more distal location (LPA obstruction). When the decision was
Catheterization and Cardiovascular Interventions DOI 10.1002/ccd. Published on behalf of The Society for Cardiovascular Angiography and Interventions (SCAI).
4
Zahn et al.
Fig. 3. Implantation sequence. A: Following deployment, but prior to release from the delivery cable, all three components of the AVPII can be visualized and a careful assessment of position made using a combination of fluoroscopy and echocardiography. B: Following release from the delivery cable, both 2 dimensional, color, and pulsed wave Doppler are utilized to ensure that the PDA is closed and that normal flow is maintained in the left pulmonary artery (white arrow) and descending aorta (*).
made that the device had closed the PDA completely and there was no impingement on LPA or aortic flow, the device was released from the delivery cable and repeat echocardiographic assessment was made. At case completion, the sheath was removed, hemostasis obtained with manual compression and the babies transferred back to the NICU to receive two further doses of intravenous antibiotics.
thereafter. Electronic medical records were reviewed for follow-up information of both the remaining hospital and outpatient course following discharge. Case review publication approval was approved by the cedars Sinai medical Center Institutional review Board. RESULTS Procedural
Follow-Up Follow-up echocardiography and chest radiographs were obtained within 24 hr and as clinically indicated
Patient demographics are shown in Table I. Median gestational age and weight at birth were 26 weeks (26–31 weeks) and 953 g (675–2,480 g), respectively.
Catheterization and Cardiovascular Interventions DOI 10.1002/ccd. Published on behalf of The Society for Cardiovascular Angiography and Interventions (SCAI).
Transcatheter PDA Closure in Premature Infants
5
TABLE I. Demographic Data Patient 1 2 3 4 5 6
Birth weight (g)
Gestational age (weeks þ days)
Sex
Procedure weight (g)
Procedure age (days)
2,480 440 1,050 1,077 856 675
31 þ 6 26 þ 4 26 þ 3 26 þ 3 26 þ 3 29 þ 0
Female Male Male Male Female Female
2,240 1,610 1,140 1,220 960 870
18 80 16 20 21 30
Median age and weight at the time of the procedure were 20 days (16–80 days) and 1,180 g (870–2,240 g), respectively. All patients had failed at least one course of COX inhibitors (or were not considered candidates for medical therapy) and were being considered for surgical ligation. Successful transcatheter ductal closure with immediate shunt resolution was achieved in all cases with a median fluoroscopy time of 9.4 min (0– 19.5 min) and procedural time of 51.5 min (33–87 min). Procedural details are shown in Table II. Patient 1, the largest in the series, underwent successful PDA closure using a retrograde arterial approach with no clinical evidence of vascular compromise. In the remaining patients, only femoral venous access was utilized and once again no clinical evidence of vascular damage was noted. Routine vascular imaging of the femoral vessels was not performed. There was no correlation between patient size and fluoroscopy or procedural times. In fact, two of the shortest cases involved two of the smallest babies (patients 3 and 5). Two device-related incidents occurred in two separate cases, resulting in increased procedural and fluoroscopy times in those patients. Patient 2 who had a large PDA, initially received a 6 mm AVP which achieved complete ductal closure but resulted in echocardiographically apparent flow obstruction in both the aorta and LPA presumably because the constrained length of this device was too long (i.e., it was oversized). The device was recaptured prior to release, removed uneventfully, and replaced with a 4 mm device, resulting in complete ductal closure and no obstruction to LPA or aortic blood flow. Patient 4 experienced the single instance of device malposition following release from the delivery cable seen in this cohort. Prior to release, the device appeared in excellent position with complete ductal closure and no obstruction to flow in either the LPA or aorta. When the device was released, there was a slight but obvious movement of the device posteriorly on fluoroscopy (Fig. 4). This correlated to an immediate change in the descending aortic Doppler flow pattern and the 2D echocardiographic appearance of the juxtaductal aorta consistent with descending aortic obstruction. The patient remained stable and the 4 Fr long
Ventilator dependence
Inotrope dependence
Yes Yes Yes Yes No YES
Yes No No No No No
sheath was replaced with a 5 Fr long sheath through which a 4-mm goose neck snare and catheter were passed. The microscrew of the AVPII was snared easily but it was clear that the device could not be recaptured using this system. Steady gentle retraction on the snare catheter and sheath were used to slowly manipulate the device into a more proximal location under echocardiographic guidance. When the aortic Doppler flow pattern returned to normal, the micro-screw was released from the snare. The final result demonstrated no obstruction to LPA or aortic flow with complete ductal closure. Follow-Up Clinical Course
At the time of this report all patients were alive and discharged from the hospital at a median follow-up of 201 days (19–278 days) from the procedure. Extubation took place a median of 22 days (5–80 days) following the procedure in the four patients who were mechanically ventilated at the time of the procedure. Three of the four have continued evidence of chronic lung disease as manifested by a persistent oxygen requirement. Patient 2, who was considerably older at the time of PDA closure (80 days), and had the most advanced lung disease, has evidence of moderate pulmonary hypertension and is currently being treated with oral Sildenafil DISCUSSION
There is little debate that the presence of a PDA in premature infants is associated with important comorbidities and increased mortality [2–6]. A recent report suggests that mortality in neonates born at < 29 weeks gestation may be increased by more than eight times in those with a PDA versus those without [18]. While it is estimated that more than 33% of very low birth weight infants (
Original Studies A Novel Technique for Transcatheter Patent Ductus Arteriosus Closure in Extremely Preterm Infants Using Commercially Available Technology Evan M. Zahn,1,3* MD, Phillip Nevin,3 RN, Charles Simmons,2 MD, and Ruchira Garg,1,3 MD Objectives: To describe a new technique for transcatheter patent ductus arteriosus (PDA) closure in extremely preterm infants using commercially available technology. Background: PDA in premature neonates continues to be a significant clinical problem contributing importantly to both morbidity and mortality. Surgical ligation and medical therapy both have their drawbacks. Material and Methods: Hospital records and catheterization reports of all premature neonates (< 32 weeks gestation) who underwent transcatheter PDA closure between March 2013 and February 2014 were reviewed. Particular attention was paid to procedural details, complications, and short and mid-term outcomes. Results: Six premature infants born at gestational ages ranging between 26 and 31 weeks (median, 26 weeks) underwent attempted transcatheter PDA closure using the Amplatzer Vascular Plug II (AVP II). Median age and weight was 21.5 days (16–80 days) and 1,180 g (870–2,240 g), respectively. Fluoroscopy and echocardiography were used to guide device. Contrast angiography was not used in any patient. Complete closure was achieved in all patients with no major procedural complications. Median fluoroscopy and procedural times were 9.4 (0–19.5) and 51.5 (33–87) min, respectively. All patients were alive at the time of this report. There were no instances of device migration, left pulmonary artery (LPA), or aortic coarctation. Conclusions: This preliminary study demonstrates that transcatheter PDA closure can be successfully performed in extremely preterm neonates using currently available technology with a high success rate and a low incidence of complications. This report also describes a novel transvenous approach using a combination of echocardiography and judicious use of fluoroscopy to avoid arterial access in this fragile patient population. VC 2014 Wiley Periodicals, Inc. Key words: congenital heart disease; vascular occlusion 1
INTRODUCTION
For more than three decades it has been known that the presence of a hemodynamically significant patent ductus arteriosus (PDA) in preterm infants increases morbidity and mortality [1–6]. To date, available treatment options have been essentially limited to medical treatment with cyclooxygenase (COX) inhibitors or surgical ligation. The former is effective in 50–70% of cases and has been associated with major adverse effects including permanent alterations in renal function, necrotizing enterocolitis, gastrointestinal perforation, and impairment of cerebral blood flow velocity [7–9]. C 2014 Wiley Periodicals, Inc. V
The Division of Pediatric Cardiology, Department of Pediatrics, Cedars Sinai Medical Center, Los Angeles, California 2 The Division of Neonatology, Department of Pediatrics, Cedars Sinai Medical Center, Los Angeles, California 3 The Heart Institute, Cedars Sinai Medical Center, Los Angeles, California Conflict of interest: Nothing to report. *Correspondence to: Evan Zahn, MD, FACC, FSCAI, 127 S. San Vicente Blvd, Suite A3600, Los Angeles, CA 90048. E-mail: [email protected] Received 19 February 2014; Revision accepted 28 April 2014 DOI: 10.1002/ccd.25534 Published online 00 Month 2014 in Wiley Online Library (wileyonlinelibrary.com)
2
Zahn et al.
tain to this procedure include excellent fluoroscopic and echocardiographic visibility, ability to reposition/ remove multiple times as needed, relatively short length (3–6 mm diameter devices have an unconstrained length of 6 mm), deliverable through a 4 Fr sheath, relatively thin and soft delivery cable, and rapid vascular occlusion. The manufacturer recommends choosing a plug with a diameter at least 20% larger than the target vessel. Importantly for the current application, the final length of the deployed device is dependent on the degree of oversizing, i.e. the more over-sized the device (more constrained) the greater the implanted length will be.
Fig. 1. Commercially available Amplatzer Vascular Plug II. The small diameters and lengths of this device, easy deliverability, and excellent fluoroscopic and echocardiographic features of this device are attributes desirable in a PDA device in small neonates.
Surgical ligation involves a limited left thoracotomy or a “less-invasive” thorascopic approach and is successful in nearly all cases but is typically reserved for patients who fail medical therapy and has been associated with significant complications including pneumothorax, hypothermia, bleeding, phrenic nerve palsy, wound infection, vocal cord paralysis, and thoracic scoliosis [10–13]. While surgical PDA ligation is more effective than medical therapy, it has not been shown to positively impact survival of the severely premature infant [14]. Transcatheter PDA closure was first described nearly four decades ago [15] and has become the procedure of choice for infants > 5 kg, children, and adults. While several devices have been used for this purpose in older children, they are not routinely used in small infants, much less premature very low birth weight neonates. Our recognition of the morbidities related to surgical ductal ligation coupled with our experience with the commercially available Amplatzer vascular plug II (AVP II) prompted our group to assess the safety and efficacy of using this device to close PDAs in severely premature neonates. MATERIAL AND METHODS Device Description The AVP II (St Jude Medical, Minneapolis, MN) is a densely woven, self-expanding nitinol plug composed of two layers of 144 braided nitinol wires constructed as two outer disks and a central plug of equal diameter (Fig. 1). Some advantages of this device as they per-
Procedural Details All cases were performed under general anesthesia with endotracheal intubation after appropriate informed consent was obtained. Prior to gaining vascular access and throughout the case, high parasternal transthoracic echocardiographic images delineating the PDA anatomy were obtained, using a Phillips iE33 ultrasound machine with a 12S transducer. Measurements were made of the ductal length and diameters (Fig. 2). Device diameter size was chosen at least 1 mm larger than the narrowest diameter of the ductus similar to what has been described in older infants and children [16]. The first case (the largest patient in the series) was performed at the bedside in the neonatal intensive care unit using a retrograde arterial approach and transthoracic echocardiographic guidance as previously described by Bentham et al [17]. The remaining cases were performed in a digital FPD biplane catheterization suite (GE Innova, Milwaukee, WI) using the lowest possible fluoroscopy settings. Attention was paid to maintaining body core temperature in the normal range throughout the procedure. A 4 Fr introducer sheath (Daig, St Jude Medical, Minnetonka, MN) was placed in the right femoral vein using a 21-gauge butterfly needle, floppy tipped 0.018 guide wire (Micropuncture set, Cook Inc, Bloomington, IN) and standard Seldinger technique. Intravenous heparin (100 mg/kg) and prophylactic antibiotics (Cefazolin, 20 mg/kg) were administered in all cases and activated clotting time monitored and maintained between 200 and 250 sec. Under fluoroscopic guidance, a 4 Fr balloon wedge catheter (Arrow International, Reading, PA) was advanced to the mid-right atrium, the balloon inflated and the stiff end of a 0.018 standard guide wire (Cordis, Miami Lakes, FL) which had been shaped into a tight curve was advanced to the tip so as to direct the catheter toward the tricuspid valve. This minimized catheter manipulation in the
Catheterization and Cardiovascular Interventions DOI 10.1002/ccd. Published on behalf of The Society for Cardiovascular Angiography and Interventions (SCAI).
Transcatheter PDA Closure in Premature Infants
3
Fig. 2. Two-dimensional transthoracic images of the pertinent anatomy obtained form the high left parasternal position. The diameter of the PDA (*) as well as the length (B) of the vessel from the pulmonary artery (PA) to descending aorta (DscAo) is shown prior to device selection. The narrowest diameter of the PDA in this patient was 2.06 mm prompting selection of a 3 mm AVPII for the closure. [Color figure can be viewed in the online issue, which is available at wileyonlinelibrary.com.]
right atrium and allowed consistent passage of the catheter into the right ventricle where it uniformly passed easily into the main pulmonary artery as the guide wire was removed. The balloon was deflated in the main pulmonary artery and a 0.014 floppy tipped coronary guide wire (Hi-torque ALL STAR, Abbott Vascular, Santa Clara, CA) with a “hockey stick” curve placed on the tip was advanced through the catheter across the PDA, down the descending aorta and into a femoral artery. The balloon end-hole catheter and introducer sheath was removed and replaced with a 4 Fr long hydrophilic sheath (Flexor Check Flo Introducer 4 Fr 45 cm, Cook Inc, Bloomington, IN), which was advanced through the right heart, across the PDA into the descending aorta. Gentle external pressure over the femoral artery where the tip of the coronary guide wire was located was used in selected cases to stabilize the guide wire and provide the stability of a veno-arterial wire rail system (without exteriorizing the wire) for passage of the long sheath. After removing the dilator and guide wire from the delivery sheath, transthoracic echocardiographic images of the ductal region and appropriate anatomy including the paraductal descending aorta and origin of the left pulmo-
nary artery (LPA) were obtained and used to guide device placement (Fig. 3). An AVP II (St Jude Medical, Minnetonka, MN) was used for PDA closure in all cases. The device was prepared in the standard fashion and advanced to the tip of the delivery sheath under fluoroscopic guidance. The sheath was brought back to the aortic end of the PDA before deploying the distal disk. Efforts were made to deploy the aortic disk directly into the aortic ampulla of the ductus. Slow controlled traction on the sheath resulted in deployment of the remaining central portion and pulmonary end of the device into the PDA. Again, efforts were made to deploy as much of the device into the actual ductus and leave as little in the main pulmonary artery as possible. A detailed echocardiographic assessment including color and spectral analysis of flow in the PDA, left pulmonary artery, and descending aorta were made prior to releasing the device from the delivery cable. When concern arose regarding obstruction of flow into the left pulmonary artery or descending aorta, the device was repositioned using either gentle traction (aortic obstruction) or partial recapture of the proximal device with redeployment in a slightly more distal location (LPA obstruction). When the decision was
Catheterization and Cardiovascular Interventions DOI 10.1002/ccd. Published on behalf of The Society for Cardiovascular Angiography and Interventions (SCAI).
4
Zahn et al.
Fig. 3. Implantation sequence. A: Following deployment, but prior to release from the delivery cable, all three components of the AVPII can be visualized and a careful assessment of position made using a combination of fluoroscopy and echocardiography. B: Following release from the delivery cable, both 2 dimensional, color, and pulsed wave Doppler are utilized to ensure that the PDA is closed and that normal flow is maintained in the left pulmonary artery (white arrow) and descending aorta (*).
made that the device had closed the PDA completely and there was no impingement on LPA or aortic flow, the device was released from the delivery cable and repeat echocardiographic assessment was made. At case completion, the sheath was removed, hemostasis obtained with manual compression and the babies transferred back to the NICU to receive two further doses of intravenous antibiotics.
thereafter. Electronic medical records were reviewed for follow-up information of both the remaining hospital and outpatient course following discharge. Case review publication approval was approved by the cedars Sinai medical Center Institutional review Board. RESULTS Procedural
Follow-Up Follow-up echocardiography and chest radiographs were obtained within 24 hr and as clinically indicated
Patient demographics are shown in Table I. Median gestational age and weight at birth were 26 weeks (26–31 weeks) and 953 g (675–2,480 g), respectively.
Catheterization and Cardiovascular Interventions DOI 10.1002/ccd. Published on behalf of The Society for Cardiovascular Angiography and Interventions (SCAI).
Transcatheter PDA Closure in Premature Infants
5
TABLE I. Demographic Data Patient 1 2 3 4 5 6
Birth weight (g)
Gestational age (weeks þ days)
Sex
Procedure weight (g)
Procedure age (days)
2,480 440 1,050 1,077 856 675
31 þ 6 26 þ 4 26 þ 3 26 þ 3 26 þ 3 29 þ 0
Female Male Male Male Female Female
2,240 1,610 1,140 1,220 960 870
18 80 16 20 21 30
Median age and weight at the time of the procedure were 20 days (16–80 days) and 1,180 g (870–2,240 g), respectively. All patients had failed at least one course of COX inhibitors (or were not considered candidates for medical therapy) and were being considered for surgical ligation. Successful transcatheter ductal closure with immediate shunt resolution was achieved in all cases with a median fluoroscopy time of 9.4 min (0– 19.5 min) and procedural time of 51.5 min (33–87 min). Procedural details are shown in Table II. Patient 1, the largest in the series, underwent successful PDA closure using a retrograde arterial approach with no clinical evidence of vascular compromise. In the remaining patients, only femoral venous access was utilized and once again no clinical evidence of vascular damage was noted. Routine vascular imaging of the femoral vessels was not performed. There was no correlation between patient size and fluoroscopy or procedural times. In fact, two of the shortest cases involved two of the smallest babies (patients 3 and 5). Two device-related incidents occurred in two separate cases, resulting in increased procedural and fluoroscopy times in those patients. Patient 2 who had a large PDA, initially received a 6 mm AVP which achieved complete ductal closure but resulted in echocardiographically apparent flow obstruction in both the aorta and LPA presumably because the constrained length of this device was too long (i.e., it was oversized). The device was recaptured prior to release, removed uneventfully, and replaced with a 4 mm device, resulting in complete ductal closure and no obstruction to LPA or aortic blood flow. Patient 4 experienced the single instance of device malposition following release from the delivery cable seen in this cohort. Prior to release, the device appeared in excellent position with complete ductal closure and no obstruction to flow in either the LPA or aorta. When the device was released, there was a slight but obvious movement of the device posteriorly on fluoroscopy (Fig. 4). This correlated to an immediate change in the descending aortic Doppler flow pattern and the 2D echocardiographic appearance of the juxtaductal aorta consistent with descending aortic obstruction. The patient remained stable and the 4 Fr long
Ventilator dependence
Inotrope dependence
Yes Yes Yes Yes No YES
Yes No No No No No
sheath was replaced with a 5 Fr long sheath through which a 4-mm goose neck snare and catheter were passed. The microscrew of the AVPII was snared easily but it was clear that the device could not be recaptured using this system. Steady gentle retraction on the snare catheter and sheath were used to slowly manipulate the device into a more proximal location under echocardiographic guidance. When the aortic Doppler flow pattern returned to normal, the micro-screw was released from the snare. The final result demonstrated no obstruction to LPA or aortic flow with complete ductal closure. Follow-Up Clinical Course
At the time of this report all patients were alive and discharged from the hospital at a median follow-up of 201 days (19–278 days) from the procedure. Extubation took place a median of 22 days (5–80 days) following the procedure in the four patients who were mechanically ventilated at the time of the procedure. Three of the four have continued evidence of chronic lung disease as manifested by a persistent oxygen requirement. Patient 2, who was considerably older at the time of PDA closure (80 days), and had the most advanced lung disease, has evidence of moderate pulmonary hypertension and is currently being treated with oral Sildenafil DISCUSSION
There is little debate that the presence of a PDA in premature infants is associated with important comorbidities and increased mortality [2–6]. A recent report suggests that mortality in neonates born at < 29 weeks gestation may be increased by more than eight times in those with a PDA versus those without [18]. While it is estimated that more than 33% of very low birth weight infants (
