Author + information
- Received March 10, 2008
- Revision received May 14, 2008
- Accepted May 20, 2008
- Published online August 1, 2008.
- David Hildick-Smith, MD, MRCP⁎,⁎ (, )
- Miles Behan, DM, MRCP⁎,
- Peter Haworth, MRCP⁎,
- Bushra Rana, MRCP† and
- Martyn Thomas, MD, FRCP†
- ↵⁎Reprint requests and correspondence:
Dr. David Hildick-Smith, Sussex Cardiac Centre, Brighton and Sussex University Hospitals NHS Trust, Brighton, United Kingdom, BN2 5BE.
Objectives Our aim was to develop a “standby intracardiac echocardiography” approach to patent foramen ovale (PFO) closures where intracardiac echocardiography (ICE) is only utilized where there are adverse features.
Background Percutaneous closure of PFO is usually aided by transesophageal echocardiography or ICE. This may be unnecessary where anatomical features are straightforward.
Methods Patients were excluded from standby ICE if they had adverse anatomical features on their diagnostic transoesophageal echocardiogram, a device other than Amplatzer (AGA Medical, Plymouth, Minnesota), STARflex (NMT Medical, Boston, Massachusetts), or BioSTAR (NMT Medical) were to be used, or they were in a clinical trial demanding ICE/transesophageal echocardiography. Procedurally, defect diameter >15 mm on balloon sizing and tunnel length >12 mm warranted ICE guidance.
Results Between April 2006 and October 2007, 124 patients underwent PFO closure. Fifty-four were excluded from standby ICE due to trial protocols (n = 22), hybrid atrial septal defect/PFO (n = 6), additional defect (n = 4), exuberant aneurysm (n = 3), or other device (n = 19, all HELEX, Gore Medical, Flagstaff, Arizona). The remaining 70 patients were age 38.1 ± 6.4 years, 49% men. Primary indication for PFO closure was stroke (n = 46, 65%), transient ischemic attack (n = 22, 31%), or decompression illness (n = 2, 3%). Sixty-four (91%) underwent contrast fluoroscopic PFO closure alone. Six patients (9%) converted to ICE-controlled closure: PFO sized to >15 mm (n = 2); difficulties crossing PFO (n = 2), or long tunnel requiring transseptal puncture (n = 2). All 70 patients had procedural success without significant complications. Procedure duration and cost favored standby ICE.
Conclusions PFO closure can, in the majority of cases, be performed safely using contrast media and fluoroscopy alone. Standby ICE facilitates closure in the remaining patients during the index procedure.
Percutaneous closure of patent foramen ovale (PFO) is an established treatment for cryptogenic stroke, orthodeoxia-platypnea syndrome, and decompression illness (1–3), and an investigative treatment for other indications (4,5). Although randomized data are lacking, except in the setting of migraine headache (6,7), PFO closure is an increasingly common interventional procedure.
The procedure has traditionally been done under general anesthesia with transesophageal echocardiographic (TOE) control (8). However, increasing operator experience, coupled with sophistication of devices and delivery equipment, have led to streamlining of the procedure, with the result that online echocardiographic assessment per procedure may not be necessary in all cases. Intracardiac echocardiography (ICE) allows PFO closure to be undertaken without general anesthesia, with associated benefits for patients (9). General anesthesia has several complications, which, although rare, can be very serious such as aspiration pneumonitis. ICE, however, is expensive, and requires additional equipment and personnel in the cardiac catheterization lab, potentially prolonging the procedure and limiting operational flexibility. ICE requires additional femoral venous cannulation, which exposes the patient to increased risk of groin complications such as arteriovenous fistula formation.
As a result, we have developed the option of “standby” ICE, such that PFO closure can be undertaken under contrast injections and fluoroscopy alone, with use of ICE only if there are unfavorable anatomical features, or technical difficulties with PFO crossing or with device positioning or deployment. We present our experience of this practice.
Patients referred to either of 2 cardiothoracic centers for PFO closure between April 2006 and October 2007 were routinely considered for contrast-guided fluoroscopic closure and standby ICE. All patients were referred by neurologists to be considered for PFO closure in the context of cryptogenic stroke, decompression illness, or migraine (within clinical trials). The study protocol was approved by the local ethics committee, and patients gave written informed consent.
All patients had formal TOE assessment of the interatrial septum before planned closure, to delineate the anatomical features of the septum and/or as the diagnostic modality. Pre-procedure exclusion criteria for fluoroscopic closure alone were:
• Clinical trial requiring ICE or TOE as part of the protocol
• Hybrid atrial septal defect (ASD)/PFO defect (i.e., resting left to right shunt as well as right to left)
• Additional interatrial septal defects
• Exuberant aneurysm
• Device other than Amplatzer, STARflex, or BioSTAR
“Exuberant aneurysm” is a subjective assessment. This term describes an extreme aneurysm with considerable redundant tissue with different folds of tissue moving in different directions. For the implantation procedure, an 11-F sheath was introduced into the right femoral vein, with the option of placement of a second 11-F sheath for the ICE catheter (from ipsilateral or contralateral femoral vein) so that the procedure could be completed at the same sitting if ICE proved necessary. If difficulties were encountered with crossing the PFO, ICE was utilized on this standby basis to facilitate crossing. Once the defect had been crossed, balloon sizing of the defect was made in all cases. The use of the balloon is beneficial because it allows the assessment of the “size” of the PFO, tunnel length, and precise fluoroscopic delineation of the location of the PFO. These benefits were felt to outweigh its potential complications such as tearing the intra-atrial septum or extending the PFO. Fluoroscopy-only closure was not attempted in cases where the balloon size of the PFO was ≥15 mm, nor where the tunnel length was ≥12 mm, and in these cases ICE was utilized.
Amplatzer, STARflex, or BioSTAR devices were used in all cases. Use of the appropriate delivery sheath allowed contrast assessment of the positioning of the device after deployment of the left atrial disc (Fig. 1). The right atrial disc could then be placed, and final contrast assessment of the anatomical placement made (Fig. 2).
Continuous variables were expressed as means and standard deviations and were compared by a 1-way analysis of variance with post hoc tests. Significance was assumed with a p value of <0.05.
During the period under consideration (April 2006 to October 2007), 124 patients underwent PFO closure at the 2 centers. Fifty-four patients were excluded from standby ICE closure on the grounds of trial protocols (n = 22), hybrid ASD/PFO (n = 6), additional defect (n = 4), exuberant aneurysm (n = 3), or other device (n = 19, all HELEX). Seventy patients were therefore considered for standby ICE PFO closure. These 70 patients were age 38.1 ± 6.4 years, 49% men. Primary indication for PFO closure was stroke (n = 46, 65%), transient ischemic attack (n = 22, 31%), and decompression illness (n = 2, 3%).
Of the 70 patients listed for standby ICE PFO closure, 64 (91%) underwent contrast fluoroscopic PFO closure alone. Six patients converted to ICE-controlled closure on the grounds of PFO sized to >15 mm (n = 2); difficulties crossing PFO (n = 2), long tunnel requiring transseptal puncture (n = 2). Patients were divided between Amplatzer (n = 43), STARflex (n = 21), and BioSTAR (n = 6) devices.
Of the 64 patients who underwent contrast-fluoroscopic-only implantation, all 64 had procedural success, with appropriate deployment of the device confirmed both fluoroscopically and on transthoracic echocardiography the next day before discharge. There were no device embolizations or other major complications. Contrast fluoroscopy delineated correct placement of the device on the interatrial septum in all cases. The other 6 cases that went on to ICE-guided closure also had successful procedures, again with confirmation of good device placement on transthoracic echocardiography the next day and no major complications.
Procedure duration, fluoroscopy time, and diamentor are shown for the 124 cases undertaken during this time (Table 1). For the 70 cases in which fluoroscopic closure was attempted, procedure duration compares favorably with the procedural duration for patients undergoing planned ICE-guided closure, or planned TOE-guided closure (under general anesthetic) during the same period.
Cost was estimated for each of the 3 modalities. Crude analysis was made on the basis of €5,000 per device, €2,500 for general anesthetic/TOE, €2,500 for ICE, €1,000 for disposables, €1,000 for overnight stay, and €500 for transthoracic echocardiography. Results are also shown in Table 1.
PFO closure is a procedure with a “zero tolerance” of complications. Recurrence rates for cryptogenic stroke are low (10), and therefore PFO closure must be performed to an exacting safety standard. As a result, there is a conflict between streamlining and simplification of the procedure on the one hand, and maintenance of absolute clinical safety on the other. While cost is always an issue, reduction of cost must not be at the expense of procedural safety. Further studies will need to be undertaken to see whether there are risks associated with PFO closure done using contrast media and fluoroscopy alone, which are not appreciated in this report. Current estimations of cost, however, do suggest a significant potential saving with use of standby ICE rather than planned ICE or planned TOE.
In most cases, PFO closure is a straightforward procedure, assuming that a comprehensive assessment of the anatomy of the interatrial septum has been made beforehand with a TOE such that more complex interatrial anatomies are not attempted fluoroscopically alone. Fluoroscopic-guided PFO closure is not suitable for all cases. However, contrast delineation of the interatrial septum is surprisingly good, particularly when using the left anterior oblique cranial projection, which profiles the septum in the majority of cases. With the Amplatzer, STARflex, or BioSTAR systems, it is possible to inject contrast once the left atrial disc is exposed to ensure that placement of the disc is correct on the left atrial side of the septum. Care must be taken to ensure that the delivery sheath is fully purged of any small air bubbles, otherwise transient inferior ST-segment elevation will result as the bubbles pass preferentially into the right coronary artery circulation with the patient supine (11). Once the right atrial disc is exposed, a further contrast fluoroscopic image can be acquired, to ensure that the device is correctly sandwiching the defect, with the appropriate “Pacman sign” (12).
If balloon sizing demonstrates a PFO >15 mm in diameter, we believe that it is not appropriate to continue to closure without ICE control, in view of the risk that the defect may be an unsuspected ASD, or that it has particularly flimsy margins. Continuing with fluoroscopic closure under these circumstances might risk device embolization.
Cases where standby ICE was used include 2 cases where a particularly long tunnel was demonstrated and a decision was therefore made to close the PFO using a transseptal puncture (13) (Fig. 3). In these cases, imaging is essential to ensure that the transseptal puncture is made directly below the septum secundum to ensure that the septum secundum is sandwiched to the septum primum by the closure device; otherwise a higher rate of residual shunting may be observed (14).
Fluoroscopic-only closure has been advocated by Dr. Meier's group for several years (15). Procedural results have been excellent, as have follow-up closure rates. It is notable however that there have been some device embolizations in this group's series (5 of 525 patients), and it may be possible to reduce this risk with a more selective fluoroscopy-only approach. Using standby ICE at least allows the operator to add echocardiographic imaging if there are unexpected difficulties, without resorting to case cancellation and rebooking.
The authors of this paper believe that PFO closure can, in the majority of cases, be performed safely and with the appropriate zero tolerance of complications using contrast media and fluoroscopy alone. Standby ICE facilitates closure in the remaining cases during the index procedure. It is now the authors' practice to do PFO closure without echocardiographic guidance in the substantial majority of cases.
- Abbreviations and Acronyms
- atrial septal defect
- intracardiac echocardiography
- patent foramen ovale
- transesophageal echocardiography
- Received March 10, 2008.
- Revision received May 14, 2008.
- Accepted May 20, 2008.
- American College of Cardiology Foundation
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