Results of Open Surgical Repair in Patients With Marfan Syndrome and Distal Aortic Dissection.

BACKGROUND: In patients with Marfan syndrome (MFS), distal aortic dissection can necessitate thoracoabdominal aortic aneurysm (TAAA) repair in survivors of acute DeBakey type I dissection and those with DeBakey type III dissection. We examined outcomes of surgical repair of TAAA in patients with MFS with distal aortic dissection. METHODS: Data were analyzed for 127 consecutive TAAA repairs performed between January 2004 and June 2014 in patients with MFS and distal aortic dissection-DeBakey types I (n = 73) and III (n = 54). The median time from dissection onset to TAAA repair was 5.2 years (interquartile range [IQR]: 2.1 to 9.8 years) for the overall group and was longer in patients with DeBakey I (6.5 years, IQR: 3.5 to 13.9 years) than patients with DeBakey III (2.9 years, IQR: 0.6 to 6.0 years, p < 0.001). Eleven patients (9%) had acute or subacute dissection at the time of repair. Sixty-six patients (52%) underwent Crawford extent II TAAA repair. A composite end point, adverse event, was defined as operative death or permanent stroke, renal failure, paraplegia, or paraparesis. RESULTS: Eight patients had adverse events (6%), including 5 operative deaths (4%). There was no permanent stroke and 1 case each of permanent paraplegia and paraparesis. At discharge, 2 early survivors (2%) had renal failure. Extent II repairs did not have substantially different outcomes from other repairs. CONCLUSIONS: In these patients with MFS with aortic dissection, open TAAA repair incurred reasonable operative risk, but improvements are needed to reduce rates of renal failure. Extent II TAAA repair does not appear to increase operative risk in patients with MFS.

Ultrasound-guided photoacoustic imaging-directed re-endothelialization of acellular vasculature leads to improved vascular performance.

As increasing effort is dedicated to investigating the regenerative capacity of decellularized tissues, research has progressed to recellularizing these tissues prior to implantation. The delivery and support of cells seeded throughout acellular scaffolds are typically conducted through the vascular axis of the tissues. However, it is unclear how cell concentration and injection frequency can affect the distribution of cells throughout the scaffold. Furthermore, what effects re-endothelialization have on vascular patency and function are not well understood. We investigated the use of ultrasound-guided photoacoustic (US/PA) imaging as a technique to visualize the distribution of microvascular endothelial cells within an optimized acellular construct upon re-endothelialization and perfusion conditioning. We also evaluated the vascular performance of the re-endothelialized scaffold using quantitative vascular corrosion casting (qVCC) and whole-blood perfusion. We found US/PA imaging was an effective technique to visualize the distribution of cells. Cellular retention following perfusion conditioning was also detected with US/PA imaging. Finally, we demonstrated that a partial recovery of vascular performance is possible following re-endothelialization-confirmed by fewer extravasations in qVCC and improved blood clearance following whole-blood perfusion. STATEMENT OF SIGNIFICANCE: Re-endothelialization is a method that enables decellularized tissue to become useful as a tissue engineering construct by creating a nutrient delivery and waste removal system for the entire construct. Our approach utilizes a decellularization method that retains the basement ECM of a highly vascularized tissue upon which endothelial cells can be injected to form an endothelium. The US/PA method allows for rapid visualization of cells within a construct several cm thick. This approach can be experimentally used to observe changes in cellular distribution over large intervals of time, to help optimize cell seeding parameters, and to verify cell retention within re-endothelialized constructs. This approach has temporal and depth advantages compared to section reconstruction and imaged fluorophores respectively.

Preservation of Capillary-beds in Rat Lung Tissue Using Optimized Chemical Decellularization.

Promoting regeneration using scaffolds created by decellularizing native tissue is becoming a popular technique applied to a variety of tissues. We demonstrate a method to decellularize highly vascular tissue keeping the vascular structure intact down to the capillary scale. Using vascular corrosion casting (VCC), we created a method for quantitatively assessing the functionality of vascular extracellular matrix (ECM) following decellularization. Murine lung tissue was decellularized using a number of techniques, then characterized using standard histological methods, as well as our quantitative VCC (qVCC) technique. Using an optimized acellular method, we successfully decellularized lung tissue while leaving behind a patent vascular network based on qualitative and quantitative histological methods.