Dislodged device during closure of patent ductus arteriosus.

Isolated PDA constitutes 6-11% of all congenital heart diseases. The size of PDA varies considerably, but most often it has a funnel shape having a wider aortic end (ampulla) and narrower pulmonary end. Device closure of PDA is costlier but causes less morbidity and may be done as a day care procedure successfully in nearly 100% cases.1 However, device dislodgement requiring surgery is of some concern, although the device dislodgement rate is 3 of 209 or 1.4% in large series.2

Case Study

A three year old female child was posted in cath Lab for PDA device closure. The size of the PDA was determined by preoperative echocardiography. Preoperative investigations like ECG, chest X-ray, routine blood examination were within normal limits.

The child was wheeled into the operation theatre and after connecting ECG electrodes, NIBP and SPO2 probe, an intravenous line was inserted. Induction of anaesthesia was done with intravenous ketamine 2mg kg-1, midazolam 0.1 mg kg-1 and fentanyl 1μg kg-1. Intubation of trachea was accomplished with 5.0 mm endotracheal tube after giving inj rocuronium 1mg/kg. Anaesthesia was being maintained with oxygen, nitrous oxide, fentanyl, vecuronium, midazolam and halothane. The child was being ventilated with Jackson Ree's modification of Ayre's T-piece.

After percutaneous puncture of the femoral vein and artery, 6F and 6F sheaths were placed in the femoral vein and artery respectively. A complete hemodynamic evaluation was performed with pressure and saturation measurements taken in all cardiac chambers. A 6F pigtail was passed up the descending aorta upto the region of the duct through the femoral artery. A biplane descending aortogram in anterioposterior and lateral projection was performed, which delineated a large and long tubular duct with a constriction at the pulmonary end and its length and minimum diameter were measured.

Subsequently, a 5F Multipurpose AI (MPAI) catheter was advanced percutaneously from the venous side through the PDA into the descending aorta. Using an exchange guidewire, the MPAI catheter was exchanged for a 7F long delivery sheath that was advanced directly through the femoral vein and positioned in the PDA. Heparin plain in a dose of 500 IU intravenous was given.

A proper size occluder (smaller diameter 2 mm larger than the narrowest diameter of the PDA) was screwed to the delivery cable, compressed into the loader and introduced into the guiding sheath. Under fluoroscopic guidance, the Amplatzer Device Occluder (ADO) was advanced into the descending aorta, where the retention disc was deployed. Once in position, the disc was pulled gently against the orifice of the PDA, which was felt as a rhythmic tugging sensation in synchrony with the cardiac cycle. Correct position was confirmed by injection of contrast medium through the aortic catheter into the descending aorta. Using gentle tension on the delivery cable, the sheath was pulled back to deploy the conical part of the device into the ductus. Once optimal position was confirmed, the ADO was released by counter-clockwise rotation of the delivery cable. A repeat aortogram was performed after device placement to document residual shunts, and left pulmonary artery or aortic obstruction.

The delivery cable was taken out from the venous end and before taking out the 6F pigtail, it was seen by fluoroscope that the device has been dislodged from its position and floating in the descending aorta.

The Pigtail was taken out immediately and a bioptome was inserted through the aorta for removal of the dislodged device from descending aorta.

The bioptome could remove the device till the external iliac artery. But from external iliac artery it could not be pulled out more. The device could not be pulled through 8F sheath, so we tried to introduce a 10 F sheath but that could not be negotiated. Apart from that repeat arteriogram showed extravasation indicating injury to external iliac artery.

Throughout the event the child was haemodynamically stable and was maintaining saturation from 98% to 100%.

The cardiothoracic surgeon was called upon and he also failed to remove the device. According to surgeon's advice, open removal of the device was decided. The child was immediately transferred by the concerned anaesthesiologists to Cardiothoracic surgery operation theatre which is nearly 300 metres (approx) from the cath lab. The patient was attached to ventilator with tidal volume of 10 ml/ kg and respiratory rate of 20/min. E.C.G, N.I.B.P and SPO2 were monitored. Anaesthesia was maintained with sevoflurane, vecuronium, midazolam and fentanyl.

Extraperitoneal approach was done to explore external iliac and common iliac artery. On exploration, there was a haematoma around the external iliac artery which was cleaned and external iliac artery was found to be bulged. The striation of the device was seen through the wall of the artery. There was no distal flow. After securing proximal and distal control, incision was made on the healthy part of the artery and the device was taken out. But there was gross laceration of the external iliac artery. So, the injured part was resected and anastomosis was done with interposition of PTFE graft. The distal flow was restored and after securing the bleeding points, the wound was closed in layers. The surgical procedure was uneventful. The child was haemodynamically stable throughout the procedure and maintained SPO2 of 99-100%. The child was reversed and extubated at the end of the procedure. The child was awake, alert and pain free after extubation with a SPO2 of 99-100%.The postoperative course was uneventful. The PDA was surgically closed uneventfully after one month.

DISCUSSION

Technological advances have made non-surgical closure of patent ductus arteriosus simple. However, there are situations where complications are encountered and surgical help is required to ameliorate the issue.3 In a case report the device was dislodged into pulmonary artery and ultimately cardiopulmonary bypass was established to remove the device.4

In our case, the device was dislodged after confirmation of its position by aortography. However, the device could be brought upto the level of external iliac artery dragged by bioptome. As soon as we found extravasation of dye into the surrounding, we took the child immediately to operation theatre. The device was ultimately removed via surgical exposure.

The anaesthetic challenge for this patient was similar to giving anesthesia to a child in a remote location. The cath labs are always located away from the cardiac O.T. We intubated the patient before the procedure started as these procedures usually take more than one hour. The problem actually began when the device was dislodged into the aorta and the procedure was lengthened by attempt to remove it via femoral artery. But as the device was brought down upto the level of external iliac artery, cardiopulmonary bypass, aortic cross clamping and related complications could be avoided.

The main challenges of anaesthesia were maintenance of proper hydration, stable haemodynamics, and prevention of hypothermia in a pediatric patient of 10 kg for nearly 10 hours. The dislodgement of the device was detected, the cardiologists tried to remove the dislodged device and failed, the cardiothoracic surgeon was called who also failed to remove it transcutaneously, and opined for open removal. Anaesthesia was well maintained for ten hours even during transport of the child from cath lab to cardiothoracic O.T. Anaesthesia was then maintained during the open removal of the dislodged device with accurate volume replacement because during surgical removal it was found the external iliac artery was severely lacerated by attempts of closed removal with extravasation of blood. Ultimately, after the removal of the dislodged device and repair of the femoral artery, the child was awake, alert, pain free and extubation was possible on table. The child recovered uneventfully and was discharged after 5 days. The PDA was surgically closed after one month and the child recovered uneventfully.

In conclusion the proper cooperation and collaboration among cardiologist, cardiothoracic anaesthesiologist and cardiothoracic surgeon is very much essential during interventional cardiology procedures.