Mind the gap: A novel endovascular technique to repair a transected vessel.

Level one trauma centers experience horrific injuries on a regular basis. Blunt or penetrating trauma causing vascular injuries are treated by surgeons and interventional radiologists. When a blood vessel is completely transected, the ends of the vessel retract and vasospasm occurs as a normal survival response. When this phenomenon occurs, it is sometimes impossible to reattach the two ends of the injured vessel by surgical means and a bypass graft is often required. However, from an endovascular perspective, covered stents can serve as a vascular bypass as well. The limiting factor with an endovascular approach is the ability to successfully gain wire access across the injured vessel. The technique described in this manuscript describes a "rendezvous" method of repairing a transected axillosubclavian artery from a high-speed motorcycle accident using a steerable microcatheter. Initially, multiple failed attempts to cross the injured vessel were encountered despite using a wide variety of conventional guidewires and catheters. A steerable microcatheter was then used to safely and effectively navigate more than 15 cm through soft tissue to the opposite end of the vessel. In this critically ill patient, this technique significantly reduced the procedural time when compared to our previous experiences repairing arterial transections using traditional catheters.

A Novel Nonvascular Application of the Steerable Microcatheter.

The percutaneous nephrostomy (PCN) is a relatively common interventional procedure used to treat a multitude of nephro-urological conditions. Traditionally, interventional radiologists use ultrasound guidance, needles, catheters, and guidewires to access the collecting system percutaneously. The placement of a nephro-ureterostomy stent may be precluded by challenging renal calyx anatomy or an underlying disease process that obstructs placement. In cases of complex obstruction, accessing the renal collecting system may require deviation from conventional methods. We present a case that after many failed attempts with a wide variety of guidewires and catheters, a steerable microcatheter (SMC) was used to safely and effectively access the renal collecting system. This novel technique utilizes the SMC to efficiently achieve complicated PCN stent placement, relieving the renal drainage system obstruction and potentially minimizing or avoiding complications, such as urosepsis and/or renal failure.

Larger Sizes Matter More! Applying the Matteo Mathematics Method for Endovascular Aortic Bifurcation Reconstruction to Large Venous Vascular Repair.

Endovascular aortobifemoral bypass repair with aortic bifurcation reconstruction is a well-established option with mortality benefits compared to conventional surgical management. The same theory, formulas, and techniques can be applied to the central venous system as long as there are commercially available devices. Using mathematically derived criteria for optimal stent size selection, endovascular aortic bifurcation reconstruction with kissing stents was extrapolated to the inferior vena cava (IVC). This report describes a traumatic case of IVC injury that was successfully repaired using the standard aortic grafts while adhering to the guidelines for proper stent size selection.

Against the Odds: A Novel Technique to Perform Cholangiography from a Percutaneous Approach through the Cystic Duct.

Percutaneous cholangiography is typically performed via a transhepatic approach and is reserved for patients with contraindications to traditional cholangiogram imaging modalities. For those with suspected cholelithiasis or choledocholithiasis who cannot undergo magnetic resonance imaging for diagnosis, percutaneous cholecystostomy with cholangiogram is a viable option. Endoscopic retrograde cholangiopancreatography may also be precluded due to anatomic or obstructive limitations, in which case, percutaneous transhepatic cholangiography (PTC) may be indicated for diagnosis. PTC may be difficult in a patient with minimal biliary tree dilatation, or tortuous cystic duct anatomy. In cases such as these, a steerable microcatheter (SMC) may be utilized to enable or expedite PTC. The technique to traverse and catheterize the cystic duct and opacify the gallbladder, bile ducts, and duodenum utilizing an SMC is described. This report outlines a non-vascular application of the SMC resulting in a successful cholangiogram, with reduced operative time and thus reduced radiation exposure to the patient.

The effects of age and the expression of SPARC on extracellular matrix production by cardiac fibroblasts in 3-D cultures.

Fibrillar collagen is the primary component of the cardiac interstitial extracellular matrix. This extracellular matrix undergoes dramatic changes from birth to adulthood and then into advanced age. As evidence, fibrillar collagen content was compared in sections from neonates, adult, and old hearts and was found to increase at each respective age. Cardiac fibroblasts are the principle cell type that produce and control fibrillar collagen content. To determine whether fibroblast production, processing, and deposition of collagen differed with age, primary cardiac fibroblasts from neonate, adult, and old mice were isolated and cultured in 3-dimensional (3D) fibrin gels. Fibroblasts from each age aligned in fibrin gels along points of tension and deposited extracellular matrix. By confocal microscopy, wild-type neonate fibroblasts appeared to deposit less collagen into fibrillar structures than fibroblasts from adults. However, by immunoblot analysis, differences in procollagen production and processing of collagen I were not detected in neonate versus adult fibroblasts. In contrast, fibroblasts from old mice demonstrated increased efficiency of procollagen processing coupled with decreased production of total collagen. SPARC is a collagen-binding protein previously shown to affect cardiac collagen deposition. Accordingly, in the absence of SPARC, less collagen appeared to be associated with fibroblasts of each age grown in fibrin gels. In addition, the increased efficiency of procollagen alpha 1(I) processing in old wild-type fibroblasts was not detected in old SPARC-null fibroblasts. Increased levels of fibronectin were detected in wild-type neonate fibroblasts over that of adult and old fibroblasts but not in SPARC-null neonate fibroblasts versus older ages. Immunostaining of SPARC overlapped with that of collagen I but not to that of fibronectin in 3D cultures. Hence, whereas increases in procollagen processing, influenced by SPARC expression, plausibly contribute to increased collagen deposition in old hearts, other cellular mechanisms likely affect differential collagen deposition by neonate fibroblasts.