Fig. 8.1
Important angiographic characteristics in closing a patent foramen ovale
Fig. 8.2
Typical angiographic PFO anatomy. Tunnel length is <12 mm and defect measures <10 mm. LA left atrium, RA right atrium
Fig. 8.3
Patient with a long-tunnel PFO, measuring 17 mm in length seen in anterior-posterior (a) and lateral (b) views. Best view for this is in the left-anterior-oblique view with slight cranial projection. The straight antero-posterior view is rarely helpful, though in this patient the tunnel can also be visualized
Fig. 8.4
(a) A properly placed CardioSeal device within the PFO, (b) a poorly placed device in a patient with a 15 mm non-compliant tunnel. The right atrial side of the CardioSeal device partially remains within the tunnel
Fig. 8.5
Example of a 25 mm Helex device being placed in a tunnel that measured 32 mm in length. (a) The right atrial locking loop becomes disjointed from the mid locking loop due to the long tunnel length. This occurred inspite of performance of the “balloon pull-through” technique to reduce the tunnel length. (b) Following a transeptal procedure, the all the locking loops appear properly spaced, closing the PFO defect
Fig. 8.6
Demonstration of the balloon “pull-through” technique for reducing PFO tunnels. In this cadaver heart, the septu primum on the left atrial side actually inverts across the defect to the right atrial side. In performing this technique in over 300 patients, we’ve only observed this finding in three patients. (a) balloon across septum primum over a wire, (b) balloon inflated and being pulled, (c) inverted septum primum
Balloon sizing offers important delineation of tunnel length and overall defect size. Although some operators use the same size device to close most PFO regardless of PFO size, this approach may increase the device embolization risk. In three cases known to the authors, balloon sizing was not initially performed and 25 mm devices were successfully placed. In each case, the devices were noted to be in proper position at discharge, but at 1 month follow-up (n = 2) and 1 year follow-up (n = 1) the devices were noted to have embolized to the descending aorta. In each case, balloon sizing was performed at the second PFO closure attempt, where the stretched PFO diameter measured between 14 and 20 mm. Atrial septal occluder devices, in each case, were successfully used to close the defects. This, combined with the potential concern of missing fenestrated atrial septal defects, is why we believe balloon sizing of PFO plays an important role in delineating proper atrial septal anatomy and in choosing the correct device type and size.
Angiographic Imaging of Residual Shunts Through Previously Placed Devices
Angiographic imaging is essential in patients with residual shunts through devices that have been previously placed within the atrial septum. Typically, these patients have PFO with exceedingly long tunnels (Fig. 8.7) requiring imaging to show the length of the residual track and the overall diameter of the residual shunt. Vascular plugs and muscular ventricular septal defect devices are typically used to close these residual shunts (Fig. 8.8). Balloon sizing of the residual tract may be performed in some instances.
Fig. 8.7
Residual shunt through a previously placed Helex device. The device had been placed 2 years prior, the patient had a recurrent stroke, with Grade 4+ shunting noted on transcranial doppler
Fig. 8.8
Placement of a 10 mm VSD device within the Helex device to close the residual defect. No residual shunt was observed at the patient’s 1 month follow-up visit
In summary, balloon sizing of PFO remains an important step during device closure to chose the correct device size, determine the presence of additional defects that need to be addressed, determine if additional techniques will be required to address a long tunnel, and to minimize embolization risk. Finally, angiography remains an essential part of the procedure in patients that have residual defects through previously placed devices.
Pulmonary Arteriovenous Malformations (AVM’s)
Less common than PFO, pulmonary AVM’s need to be considered in cases with evidence of right-to-left shunt where there is no inter-atrial communication. Since routine pulmonary artery angiography is not performed in closure of PFOs, a high grade of suspicion is necessary to decrease the likelihood of missing this unusual diagnosis.
Background
Pulmonary AVM’s occur twice as often in women compared to men [3]. Hereditary Hemorrhagic Telangiectasia (HHT), also known as Rendu-Osler-Weber syndrome, is an autosomal dominant condition characterized by arteriovenous malformations (AVM) in the skin, mucous membranes, and visceral organs. Nearly 70 % of the cases of pulmonary AVM are associated with HHT, whereas only 15–35 % of patients with HHT have PAVM [4–7]. The most common symptom of pulmonary AVM is epistaxis (mostly from concurrent HHT). The second most common symptom is dyspnea and platypnea (improved breathing upon reclining), which also may be seen with hepatopulmonary syndrome [3, 8]. Fifty-three to 70 % of pulmonary AVMs are found in the lower lobes [9–13]. Pulmonary AVMs are classified as either simple or complex. Eighty to ninety percent of pulmonary AVM are of the simple type—defined as those with a single feeding segmental artery and a single draining vein (Fig. 8.9a, b) [13–15]. The rest are complex, with two or more feeding arteries or draining veins (Fig. 8.10a, b) [14].
