AT was symptomatic in >95% of these patients and involved multiple arteries in approximately 18% of patients. The anatomical distribution of arterial thrombotic events was wide, occurring in limb arteries (39%), cerebral arteries (24%), great vessels (aorta, common iliac, common carotid, and brachiocephalic trunk; 19%), coronary arteries (9%), and superior mesenteric artery (8%). The mortality rate in these patients is approximately 20%. AT occurs in approximately 4% of critically ill COVID-19 patients. It often presents symptomatically and can affect multiple arteries. Further investigation of the underlying mechanism of AT in COVID-19 would be needed to clarify possible therapeutic targets. AT occurs in approximately 4% of critically ill COVID-19 patients. It often presents symptomatically and can affect multiple arteries. Further investigation of the underlying mechanism of AT in COVID-19 would be needed to clarify possible therapeutic targets. Identifying fragile aortas that are more likely to lead to adverse clinical outcomes would provide surgeons with a better sense of how to balance the risks of surgical versus medical management in patients with type B dissections. We examine the progression of a type B dissection into a type A dissection in a patient and analyze changes in the Gaussian surface curvature distribution, as well as the response of the stress distribution at the lesser curve in response to pressurization. We hypothesize that examining the Gaussian curvature will provide us with a link between aortic surface geometry and the stress distribution, which is crucial to understanding the process driving aortic dissection. Computed tomography scans of a patient before and after the type A dissection are obtained. These are segmented in Simpleware ScanIP. Centerline curvatures are calculated on segmented models in ScanIP. Models are then pressurized in the finite element analysis software Abaqus. The Gaussian curvature is calculated bth the stress focusing seen in the before type A geometry. We propose that the geometric focusing before type A creates a higher energy stress state, which is relaxed on retrograde dissection. Thus, Gaussian curvature analysis may provide a window to capture underlying geometric instability in type B dissections. Our analysis demonstrates that Gaussian surface curvature analysis captures changes in aortic geometry that are otherwise silent in centerline curvature analysis. Here, we show that as the aorta develops a type A dissection it is able to more smoothly handle the hoop stress at the lesser curve compared with the stress focusing seen in the before type A geometry. We propose that the geometric focusing before type A creates a higher energy stress state, which is relaxed on retrograde dissection. Thus, Gaussian curvature analysis may provide a window to capture underlying geometric instability in type B dissections. The lack of a viable plantar flap in patients undergoing transmetatarsal amputation has been considered an indication for below-knee amputation (BKA). In an effort to reduce limb loss in this patient population, we sought to review our experience with transmetatarsal amputation salvage in patients with an open, guillotine transmetatarsal amputation. We hypothesized that performing a transmetatarsal amputation without a viable flap would extend time of independent ambulation and improve limb salvage. This is a retrospective review of 27 consecutive patients who did not have a viable plantar flap and who underwent an open, guillotine transmetatarsal amputation. Patients presented with a nonviable plantar flap due to either extensive tissue loss on initial presentation, or secondary transmetatarsal amputation (TMA) flap necrosis. Patients initially underwent an open, guillotine TMA for control of infection and debridement of nonviable tissue. To achieve best results, during procedure, the metatarsals were re, 3 are ambulatory and still undergoing wound care, one was lost to follow-up. Overall, 19 patients (70%) have completely healed with a median time to heal of 82days. Limb salvage in patients with a nonviable plantar flap for TMA is possible and should be a considered procedure. https://www.selleckchem.com/products/inx-315.html This technique has the potential to improve functional outcomes and limb salvage in patients who might otherwise undergo BKA. Limb salvage in patients with a nonviable plantar flap for TMA is possible and should be a considered procedure. This technique has the potential to improve functional outcomes and limb salvage in patients who might otherwise undergo BKA. Chronic limb threatening ischemia in octogenarians presents unique treatment challenges in patients with multiple comorbidities and variable functional status. Endovascular interventions offer a better risk profile; however, this is not always a feasible option for anatomic or disease-specific reasons. This study compares outcomes of peripheral bypass versus amputation in octogenarians. The American College of Surgeon's National Surgical Quality Improvement Program database was queried from 2013 to 2016 for patients >80 years undergoing femoral-popliteal bypass (FPB), femoral-tibial bypass, or popliteal-tibial bypass with vein or prosthetic graft versus above-knee amputation (AKA) or below-knee amputation. Patients presenting with systemic inflammatory response syndrome, sepsis, septic shock, or a leukocytosis >11,000 were excluded. Patient demographics, risk factors, and 30-day unadjusted outcomes were analyzed. Multivariate regression analysis was then performed to compare risk adjusted 30-day mority between the groups. Contemporary risk-adjusted 30-day morbidity and mortality for bypass versus amputation in octogenarians show no significant difference. These data demonstrate that aggressive surgical limb salvage can be safe in well-selected patients in this age group. Contemporary risk-adjusted 30-day morbidity and mortality for bypass versus amputation in octogenarians show no significant difference. These data demonstrate that aggressive surgical limb salvage can be safe in well-selected patients in this age group.