Design and Realization of 3D Printed AFM Probes.

Atomic force microscope (AFM) probes and AFM imaging by extension are the product of exceptionally refined silicon micromachining, but are also restricted by the limitations of these fabrication techniques. Here, the nanoscale additive manufacturing technique direct laser writing is explored as a method to print monolithic cantilevered probes for AFM. Not only are 3D printed probes found to function effectively for AFM, but they also confer several advantages, most notably the ability to image in intermittent contact mode with a bandwidth approximately ten times larger than analogous silicon probes. In addition, the arbitrary structural control afforded by 3D printing is found to enable programming the modal structure of the probe, a capability that can be useful in the context of resonantly amplifying nonlinear tip-sample interactions. Collectively, these results show that 3D printed probes complement those produced using conventional silicon micromachining and open the door to new imaging techniques.

Comparison of Ultrasound-Guided Thrombin Injection of Iatrogenic Pseudoaneurysms Based on Neck Dimension.

BACKGROUND: Ultrasound-guided thrombin injection (UGTI) of femoral artery pseudoaneurysms after endovascular procedures is an effective therapy. There is controversy in the literature regarding injecting pseudoaneurysms with short and/or wide necks. This article reports our experience in UGTI of pseudoaneurysms in 1 hospital regarding the efficacy of this treatment in all pseudoaneurysms regardless of the size of the necks. METHODS: A retrospective review of 46 patients diagnosed between 2011 and 2016 with groin pseudoaneurysms using established duplex ultrasound criteria. Mean age was 68 years (range 27-87). Ten pseudoaneurysms thrombosed spontaneously, 5 were thrombosed by ultrasound-guided compression, and 2 were treated surgically due to disqualifying criteria. In this retrospective review, we analyzed the remaining 29 pseudoaneurysms regarding the dimensions of their neck lengths and outcomes after attempting thrombin injection. RESULTS: The mean aneurysm neck length and width were 1.03 ± 0.9 cm and 0.30 ± 0.1 cm, respectively. All 29 patients were evaluated with respect to pseudoaneurysm size, neck length, neck width, and complexity. Successful treatment of 29 pseudoaneurysms (2 external iliac, 20 common femoral, 2 deep femoral, and 5 superficial femoral) with UGTI was achieved without complications in 100% of the cases, regardless of pseudoaneurysm size, neck dimensions, or complexity. Anticoagulation status did not affect the efficacy of the procedure. Nine of the 29 pseudoaneurysms (31.0%) had neck length less than 0.5 cm. CONCLUSIONS: This study demonstrates the safety and efficacy of UGTI in treating iatrogenic pseudoaneurysm in 29 of 29 patients, even in patients with pseudoaneurysm with short neck lengths. Our experiences support injecting all pseudoaneurysms irrespective of dimension.

Successful Revascularization of Aortic Arch in a 39-Year-Old Blunt Trauma Patient with Acute Diffuse Axonal Injury without the Use of Systemic Anticoagulation.

Blunt traumatic aortic injury is the second leading cause of death in trauma patients aged 4-34 years. Of the patients who are able to receive treatment, mortality rates as high as 40% have been reported. Endovascular repair options have allowed for more expeditious repairs with reduced iatrogenic trauma; however, when the injury involves the ascending aorta or arch, current endografts lack fenestrations needed for cerebral blood flow. Traditionally, on pump, cardiopulmonary bypass with systemic anticoagulation has been used to repair these injuries. In this paper, we describe a unique case of repairing a large traumatic aortic arch pseudoaneurysm in the setting of which systemic anticoagulation is contraindicated. The patient is a 39-year-old otherwise healthy Hispanic male who presented to Ryder Trauma Center in Miami, Florida, following a motor vehicle collision and found to have multiple intracranial hemorrhages and a large aortic pseudoaneurysm of the distal ascending aorta. In lieu of standard cardiopulmonary bypass, a hybrid approach was utilized. Cranial blood flow was maintained using a temporary extra-anatomical left femoral to bilateral carotid bypass during endovascular coverage of the aortic arch. Aortic arch revascularization was then achieved by means of in situ laser fenestration of the innominate artery followed by a right-to-left carotid-carotid-subclavian bypass. This case demonstrates the viability of a hybrid vascular repair of a complex aortic disruption without the use of systemic anticoagulation in the setting of contraindicated or unknown risk of systemic anticoagulation. Further research is warranted on whether emergent traumatic cases with contraindications to anticoagulation can be performed in a similar fashion to safely reduce the morbidity and mortality associated with aortic disruptions.

The ribs or not the ribs: which influences mortality?

BACKGROUND: The relative impact of rib fractures on mortality risk is unclear. This study examined the respective relationships between mortality and the number of fractured ribs, patient age, and severity of intrathoracic and extrathoracic injuries. METHODS: The National Trauma Data Bank was queried, abstracting mortality, age, number of ribs fractured, associated intrathoracic and extrathoracic injury, and Abbreviated Injury Score codes. RESULTS: Multivariate logistic regression indicated the strongest influence on mortality was severity of intrathoracic injury, followed by severity of extrathoracic injury, age 65 years or older, more than 5 ribs fractured, and age 46 to 65 years. The mortality rate for isolated rib fractures ranged from 1.8% to 3.2%. CONCLUSIONS: Mortality related to rib fractures is affected independently by severe intrathoracic injury, presence of extrathoracic injury, advanced age, and more than 5 fractured ribs. Patients with these conditions may benefit from a higher level of care.