Ruptured giant splenic artery aneurysm with an exceptional concurrent gastric and transverse colonic fistula: A rare case report.

INTRODUCTION: Splenic artery aneurysm (SAA) is a focal dilation of the splenic artery with varying etiologies including atherosclerosis, arteritis, or trauma. Giant SAAs with a diameter of 10 cm is rare and can lead to severe complications like rupture and fistulas. Therefore, an accurate and timely diagnosis and treatment are important. PATIENT CONCERNS: A 50-year-old male presented with acute epigastric pain and hemorrhagic shock. Considering his symptoms and examination, ultrasound, multi-slice computed tomography and digital subtraction angiography results, a ruptured giant splenic artery aneurysm complicated with an exceptional gastric and transverse colonic fistula was suspected. DIAGNOSIS: Ruptured giant splenic artery aneurysm. INTERVENTIONS: Left anterolateral thoracotomy to control the severe aortic bleeding just above the diaphragm, aneurysmectomy, splenectomy, and closing the gastric and transverse colon perforations. OUTCOMES: Multi-slice computed tomography demonstrated the presence of splenic artery aneurysm in the distal third measuring (10 × 12 cm) in diameter with a true lumen measuring (7 × 3.5 cm) and a large hematoma extending to the greater and lesser gastric curvature. Intraoperatively, a large pulsating mass was detected occupying the epigastrium and the left hypochondrium with severe adhesions with the stomach and transverse colon. CONCLUSION: Giant SAA with a diameter of 10 cm is rare and is associated with severe complications. Therefore, successful treatment of splenic artery aneurysms involves prompt diagnosis, immediate surgical intervention to control bleeding, and tailored approaches like thoracotomy to control the thoracic aorta for better hemodynamic stabilization, aiming to eliminate the aneurysm and reduce complications effectively.

Launching Coherent Acoustic Phonon Wave Packets with Local Femtosecond Coulomb Forces.

Generation and manipulation of coherent acoustic phonons enables ultrafast control of solids and has been exploited for applications in various acoustic devices. We show that localized coherent acoustic phonon wave packets can be launched by ultrafast Coulomb forces in a scanning tunneling microscope (STM) using tip-enhanced terahertz electric fields. The wave packets propagate at the speed of the longitudinal acoustic phonon, creating standing waves up to 0.26 THz for a 6.4 nm thin Au film on mica. The ultrafast lattice displacement can be as large as 5 pm and is precisely controlled by varying the tip-sample distance. This nonthermal femtosecond Coulomb-force-based excitation mechanism is applicable in nano-optomechanics for advanced terahertz engineering and opens new perspectives in exploiting coherent phonons at the atomic scale.

Variable Repetition Rate THz Source for Ultrafast Scanning Tunneling Microscopy.

Broadband THz pulses enable ultrafast electronic transport experiments on the nanoscale by coupling THz electric fields into the devices with antennas, asperities, or scanning probe tips. Here, we design a versatile THz source optimized for driving the highly resistive tunnel junction of a scanning tunneling microscope. The source uses optical rectification in lithium niobate to generate arbitrary THz pulse trains with freely adjustable repetition rates between 0.5 and 41 MHz. These induce subpicosecond voltage transients in the tunnel junction with peak amplitudes between 0.1 and 12 V, achieving a conversion efficiency of 0.4 V/(kV/cm) from far-field THz peak electric field strength to peak junction voltage in the STM. Tunnel currents in the quantum limit of less than one electron per THz pulse are readily detected at multi-MHz repetition rates. The ability to tune between high pulse energy and high signal fidelity makes this THz source design effective for exploration of ultrafast and atomic-scale electron dynamics.