January

Use of a dilatable exGraft™ conduit in single ventricle palliation

Use of a dilatable exGraft™ conduit in single ventricle palliation. Qadir A, Tannous P, Stephens EH, Kalra A, Forbess JM, Nugent A. Ann Thorac Surg. 2020 Jan 25. pii: S0003-4975(20)30075-8. doi: 10.1016/j.athoracsur.2019.12.024. [Epub ahead of print] PMID: 31991132 Similar articles Select item 31982878   Take Home Points: The major limitation of conduits made with prosthetic material is that they do not dilate much or grow with the patient. The development of a novel, balloon-expandable ePTFE conduit may change the management of patients that require a prosthetic conduit. This is the first published case of this conduit. Commentary from Dr. Timothy Pirolli (Dallas), section editor of Congenital Heart Surgery Journal Watch: Surgically-placed conduits and vascular grafts are commonplace in congenital heart surgery. One obvious limitation to placing a prosthetic conduit between a ventricle and great vessel (as opposed to a homograft or autograft) is the lack of growth potential. A prosthetic conduit that could be dilated could revolutionize the field, as it would add the ability to minimize or delay redo surgeries, thus decreasing the associated morbidity and mortality. A start-up company in Pittsburgh (PECA labs) has developed a novel version of the ePTFE graft that has been shown to be dilated up to 200% its original diameter in bench trials. I chose to highlight this case report because of its novelty. As a disclaimer, I am an unpaid consultant for this company and have had the ability to collaborate with this group of researchers on animal studies, some of which are on-going. Thus, I can attest first-hand that the graft handles well and does indeed dilate without significant recoil months after implantation. The graft also has the novel advantage of having radiopaque markers on it to allow for safer dilation during catheterization (Figure 1). As mentioned in this case report, the graft is FDA-approved and available for surgical implantation in human beings. This report represents the first published case of implantation and dilation of the novel exGraft™ in a patient undergoing congenital heart surgery. The case report describes a relatively standard Stage 1 palliation of a baby born with hypoplastic left heart syndrome (MA/AA). The surgeon used of a 6 mm exGraft™ as an RV-PA (Sano) conduit in lieu of the relatively standard ring-enforced PTFE graft that is often used for Sano construction. Aspirin alone was used for shunt thrombosis prophylaxis. The patient underwent a pre-Glenn catheterization at age 5 months. A gradient across the conduit was found to be 60-65 mmHg and the conduit was then dilated to 9 mm by serial dilations (Figure 2). There was mild residual narrowing at the insertion site into the pulmonary arteries, but otherwise the conduit held its dilated diameter and did not require a stent placement. The patient proceeded to a Glenn at 7 months of age that had an uncomplicated postoperative course. At the time of the explant of the conduit, it had maintained its internal diameter 2 months after dilation (Figure 3). As stated, this is the first published application of the novel exGraft™ in congenital heart surgery. The safe dilation of the graft to 150% its original diameter in this patient represents a potential milestone for our field. The use of the exGraft™ as a Sano conduit during a stage 1 palliation represents one of many potential uses of this graft. There is a range of sizes that would allow the graft to be used as a modified BT-shunt, interposition graft on large vessels, Fontan conduit and RV-PA conduits on larger children. The ability to implant and later enlarge a prosthetic graft would certainly decrease the morbidity and mortality associated with surgical correction of conduit dysfunction. The company is also working on valved-conduits that are balloon expandable, but those studies are still ongoing. In summary, the exGraft™ from PECA labs has the potential to change the paradigm of the timing and frequency of certain congenital heart surgical procedures.     Figure 1: Radiopaque markers on outer surface of an 8 mm exGraft Figure 2: In vivo dilation of the exGraft RV-PA conduit. A) Baseline angiogram demonstrating slight luminal irregularity and proximal stenosis of the exGraft. B) Stored fluoro image of maximum balloon dilation to 9 mm. (C and D) Final exGraft angiograms in lateral and caudal angulation showing interval increase in graft diameter. Figure 3: Images of explanted conduit. Note radio-opaque markers on outer surface of graft.

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Routine Surveillance Catheterization is Useful in Guiding Management of Stable Fontan Patients. Patel ND, Sullivan PM, Sabati A, Hill A, Maedler-Kron C, Zhou S, Shillingford N, Williams R, Takao C, Badran S. Pediatr Cardiol. 2020 Jan 24. doi: 10.1007/s00246-020-02293-3. [Epub ahead of print] PMID: 31980851 Take Home Points: • Routine cardiac catheterization is a common part of Fontan surveillance algorithms. • Despite appearing to be clinically stable, a large proportion of Fontan patients in this cohort required transcatheter interventions; required initiation of pulmonary vasodilator therapy; and were identified to have hepatic fibrosis. Commentary from Dr. Konstantin Averin (Edmonton), catheterization section editor of Pediatric Cardiology Journal Watch: As survival of patients with single ventricle physiology palliated with a Fontan circulation improves it is becoming increasingly recognized that they are prone to developing significant end organ pathology. Various monitoring strategies have been proposed but all usually involve a surveillance catheterization 5-10 years after the Fontan surgery. The value of this assessment has not been fully explored. The authors sought to explore the utility of surveillance cardiac catheterization in stable Fontan patients at a single center. Sixty-three Fontan patients (mean age 14.6 ± 3.0 and mean time from Fontan surgery 11.3 ± 3.1 years) underwent cardiac catheterization over a 5-year period. The pre-catheterization echocardiograms (within a year) were unremarkable – 80% had normal ventricular function and less than mild AVV insufficiency. Baseline hemodynamics were mostly reassuring with 4 patients having a Fontan pressure > 15 mmHg and 19 having a PVRi > 2.0 iWu. Vasoreactivity testing with iNO was performed in 53 and half had a reduction in the PVRi of at least 20%. Fifty-seven patients underwent a trans-jugular liver biopsy at the time of procedure with more than half (32/57) demonstrating higher grades of congestive hepatic fibrosis. Forty percent of patients had an intervention at the time of the procedure: pulmonary artery stent (16), existing stent dilation (5), SVC angioplasty (4), Fontan stent (3), and others (7). There were no major complications. Despite the limitations of this work, the authors demonstrate that routine invasive assessment of Fontan patients can provide valuable information and allow for optimization of the Fontan circulation. Given the high morbidity experienced by this patient population it is important for providers to be pro-active in longitudinal Fontan assessment management as a stable Fontan is not necessarily a good Fontan

Routine Surveillance Catheterization is Useful in Guiding Management of Stable Fontan Patients. Patel ND, Sullivan PM, Sabati A, Hill A, Maedler-Kron C, Zhou S, Shillingford N, Williams R, Takao C, Badran S. Pediatr Cardiol. 2020 Jan 24. doi:...

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Imaging of the pulmonary vasculature in congenital heart disease without gadolinium contrast: Intraindividual comparison of a novel Compressed SENSE accelerated 3D modified REACT with 4D contrast-enhanced magnetic resonance angiography

Imaging of the pulmonary vasculature in congenital heart disease without gadolinium contrast: Intraindividual comparison of a novel Compressed SENSE accelerated 3D modified REACT with 4D contrast-enhanced magnetic resonance angiography. Pennig L, Wagner A, Weiss K,...

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