ductus arteriosus

We have modified and applied to selected outpatients the transvenous approach to correction of patent ductus arteriosus (PDA) with the Rashkind PDA Occluder. Modifications included establishing the diagnosis and PDA anatomy before catheterization with echocardiography. The sedation/anesthetic regimen was altered to meet the needs with respect to transcatheter PDA closure rather than diagnostic cardiac catheterization. Anticoagulation was avoided. A strategy for management of pin entrapment in the foam was devised. Residual trans-PDA flow after umbrella placement was temporarily occluded with balloon-tipped catheters. These modifications were used in 23 consecutive patients with uncomplicated PDA. Closure was successful in each child. Nineteen of 23 patients were discharged on the day of the procedure. No serious complications were encountered. Circulation 77, No. 5, 1068-1071, 1988. IN 1939, Gross and Hubbard1 began the era of congenital heart surgery when they reported the first successful ligation of a patent ductus arteriosus (PDA). The 7-year-old patient, who had an uneventful postoperative recovery, was hospitalized at the Children's Hospital in Boston for a total of 22 days; 6 hospital days because of "general interest" in the case. Surgical management of the PDA has since been highly refined to a very safe and effective procedure, with the average hospitalization now lasting about 1 week. In recent years alternative methods of PDA closure have been investigated. In 1967 Porstmann et al.2 introduced a transvascular closure technique (via cutdown); more recently, Rashkind and Cuaso3 described use of a double umbrella device introduced percutaneously to achieve closure. Subsequently, Bash and Mullins4 modified Rashkind's technique such that it could be accomplished by a transvenous percutaneous approach. Recent data on transcatheter closure indicate a success rate of about 65%; Rashkind et al.5 have noted a clinical success rate of about 84% in their most recent clinical study. We have further modified the transvenous approach to achieve successful outpatient closure of a PDA reliably and safely. From the Departments of Anesthesia and Cardiology, The Children's Hospital, and the Departments of Anesthesia and Pediatrics, Harvard Medical School, Boston. Address for correspondence: James E. Lock, M.D., Department of Cardiology, Children's Hospital, 300 Longwood Ave., Boston, MA 02115. Received Dec. 14, 1987; accepted Feb. 4, 1988. Dr. Lock is an Established Investigator of the American Heart Association. Methods Preliminary studies. Based on initial animal studies,6 our first 12 procedures in children were performed transvenously on an inpatient basis. Informed consent was obtained from the patient and /or the patient's parents. The FDA protocol for transcatheter closure of PDA was approved by the Committee of Clinical Investigation at the Children's Hospital. We used our standard sedation technique of premedication with a meperidine compound (Breon Laboratories), local anesthetic, and supplemental sedation (morphine, diazepam) as needed. Patients were given heparin (100 units/kg) intravenously, several sets of hemodynamic data were obtained, multiple aortograms were performed with large arterial catheters to determine ductal anatomy, and ductal closure was then attempted by a modified transvenous long-sheath approach.6 These initial procedures were lengthy (3 to 4 hr total duration) and the success rate (67%) was similar to that previously reported. Ductal closure was only partial in two of the 12 patients, due perhaps to increased PDA flow and/or systemic anticoagulation. Patient restlessness, incomplete sedation, and snaring of the umbrella foam by the guidewire in another two children resulted in embolization of the umbrella device into the left pulmonary artery. Retrieval of the device in these two patients was accomplished uneventfully at the time of surgical ligation of the PDA. Based on our animal studies and these initial clinical experiences, we modified our technique in the following ways: (1) The diagnosis and PDA anatomy were established before catheterization. (2) The sedation/anesthetic regimen was altered to meet the needs with respect to transcatheter PDA closure rather than those of diagnostic cardiac catheterization. (3) Systemic anticoagulation was avoided. (4) A strategy for management of pin entrapment in the foam was devised. (5) Residual trans-PDA flow after umbrella placement was temporarily occluded with balloon-tipped catheters. These modifications were then used in 23 consecutive patients with uncomplicated PDA. Procedure. All children over 6 kg with an apparent PDA underwent complete examination and Doppler echocardiography as outpatients. Those with an isolated, restrictive (i.e., without pulmonary hypertension) PDA of less than 10 mm in diameter and in the typical location were offered either surgical ligation or transvascular closure in the cardiac catheterization CIRCULATION 1068 by gest on O cber 9, 2017 http://ciajournals.org/ D ow nladed from THERAPY AND PREVENTION-CONGENITAL HEART DISFASE laboratory on an outpatient basis. One child with a nonrestrictive PDA and pulmonary vascular disease was hospitalized before and after a combined diagnostic and interventional catheterization (successful) for assessment of pulmonary resistance. Twenty-three patients opted for outpatient transcatheter closure; they were examined in the cardiac clinic the day before closure. Ductal anatomy was assessed with two-dimensional, Doppler, and color flow echocardiography. The patients reported to ambulatory surgery the next morning, where they were premedicated with morphine (0.1 to 0.2 mg/kg iv or im). After transfer to the catheterization laboratory, the groin was prepared and infiltrated with local anesthetic. The femoral vein was cannulated with a 7F sheath, and the artery was cannulated with a No. 4F (patient less than 20 kg) or No. 5F ultrathin-walled Teflon pigtail catheter.7 Catheters were flushed with heparinized saline, but heparin was not administered. Right and left heart catheterization were rapidly performed with the patient awake, sedated, and breathing room air spontaneously. Care was taken to leave the arterial catheter in the descending aorta whenever possible. The precise size, configuration, and location of the PDA were determined via a retrograde aortogram. Catheter manipulation in the duct (and consequent ductal spasm) was avoided before aortography. A No. 7F balloon and end-hole catheter and/or 0.038 straight guidewire were then advanced from the main pulmonary artery across the PDA into the aorta. The patient was then anesthetized with intravenous ketamine and the catheter was removed over a 260 cm long, 0.038 inch guidewire and the groin was predilated with a dilator one French size larger than the long sheath. The Rashkind PDA occluder with either the knuckle/eye or pin/pin mechanism was used for PDA occlusion (USCI, Billerica, MA). For small PDAs (3 mm or less), a No. 8F long sheath and the 12 mm umbrella were used; for larger PDAs (4 to 10 mm) we used a No. 11iF long sheath and the 17 mm umbrella. The curve on the long sheaths was partially straightened to about 90 degrees with use of steam. The sheath and dilator were advanced across the PDA over the guidewire into the aorta. The precise PDA position was again confirmed after an injection of contrast by hand through the long sheath or pigtail; we have found that transvenous placement of a long sheath through the PDA can distort the ductal position as much as 5 to 8 mm. The patient was then anesthetized (1 mg/kg iv ketamine). After soaking the umbrella foam disks in topical thrombin for 5 to 10 min, the umbrella was loaded and advanced to the end of the sheath as previously described.4 6 8 With the center of the double umbrella held at the aortic end of the duct, the long sheath was withdrawn until only the distal arms opened fully in the periductal aorta. The entire system was withdrawn until the distal arms flexed inward; the umbrella position was held constant and the sheath was withdrawn until the proximal arms opened (figure 1). The fully sprung (but unreleased) device was gently moved back and forth to confirm correct position, and then released. Any ensnarement of the release wire in the foam disks was managed by pinning the umbrella with the long sheath against the pulmonary end of the duct, allowing the wire tip to be safely freed (figure 2). Immediately after release of the umbrella, a test aortogram was performed with the aortic pigtail catheter; if more than trivial ductal shunting persisted, the delivery catheter was removed and replaced with a No. 7F balloon end-hole catheter. This catheter was advanced to the pulmonary end of the PDA, and the inflated balloon was "pressed" against the umbrella for 10 to 15 min to reduce flow and promote PDA thrombosis (figure 3). After emergence from anesthesia each patient was admitted to the recovery area. A chest x-ray was obtained 4 hr later to confirm device position. The puncture sites, pulses, and vital signs were monitored routinely, and children were discharged the same day when awake, alert, drinking fluids, and ambulating FIGURE 1. A, Lateral view of aortogram from a 1-year-old patient demonstrating patency of the PDA (arrow) and filling of the pulmonary artery with contrast. B, Same patient with double umbrella occluder in place in the ductus, and long sheath and delivery device visible in the pulmonary artery. C, Repeat aortogram showing occlusion of the ductus. appropriately for age. Each patient was examined at a follow-up (1 to 6 months).