The novel coronavirus disease 2019 has imposed a severe strain on healthcare 23 2 systems worldwide and is now impacting all hospitals in the United States. 1 As of this writing in 1 early April 2020, most large medical centers in the US have either restricted or completely 2 cancelled elective surgical procedures, including cardiovascular procedures. A recent survey of 3 vascular surgery practices around the world found that most have significantly scaled back 4 elective surgery in the face of the pandemic. 2 We have addressed these challenges by modifying 5 our surgical indications and work flow to accommodate the constraints of this new environment 6 while continuing to provide appropriate and timely surgical care for patients with aortic disease.
Here we describe the modifications we have implemented in clinical care provided by the 8 multidisciplinary Aortic Disease Program at our large regional referral institution to address the 9 challenges presented by the COVID-19 pandemic. been shown to play a role in aneurysm progression, 7 so it is theoretically possible that COVID- 16 19 may worsen aortic disease or cause increased aortic complications. More data are needed to 17 evaluate this question as patients with concomitant COVID-19 and aortic disease are identified 18 and followed. Unfortunately given the rapid escalation of this worldwide pandemic, we do not 19 have the luxury of waiting for definitive data regarding the effects of COVID-19 on the 20 cardiovascular system-we must proceed in the face of this uncertainty to continue to take care 21 of patients. 8 (Figure 1) . 13 Most patients with isolated descending thoracic or abdominal aortic aneurysms less 22 than 6.5 cm and root, ascending or arch aneurysms less than 6.0 cm have been postponed until 23 the surge has passed, which we anticipate will be in 2-3 months. Patients with both proximal 1 aortic aneurysms (root, ascending, or arch) aneurysms and coronary artery disease or valve 2 disease are being considered on a case-by-case basis. Symptomatic aortic stenosis with 3 concomitant aortic aneurysm is classified as time-sensitive and we have proceeded with these 4 procedures. Patients with subacute or chronic Type B aortic dissections who otherwise meet our 5 criteria for TEVAR have similarly been delayed until after the surge passes. The locoregional 6 impact of COVID-19 should be considered as each hospital system and aortic surgery practice 7 develops an individualized approach to prioritization of scheduling. Clearly, hospitals with 8 higher burdens of COVID-19 patients will likely be forced to impose stricter restrictions on 9 elective surgical scheduling.
10 11
We have also considered altering our operative plan for patients with aortic disease in need of 13 high-risk operations to take into consideration the current and projected constrained resources of 14 our hospital system due to the pandemic. Should patients be temporized with an expeditious 15 strategy of stabilization through endovascular repair rather than a definitive open repair to 16 decrease the length of stay and preserve scarce hospital resources? Should an anticipated need 17 for personal protective equipment (PPE), blood products, or prolonged intubation or ICU stay in 18 this time of constraint play a role in decision making? We recently treated a patient who 19 presented with a ruptured thoracoabdominal aneurysm by utilizing a temporizing TEVAR 20 procedure rather than performing a more definitive, but more resource intensive, open repair.
While we were able to achieve an adequate proximal seal in Zone 2 of the arch, we accepted a 22 suboptimal distal landing zone within aneurysm thrombus in the supraceliac aorta (Figure 2 ).
This approach stabilized the patient and reduced utilization of hospital resources. She was 1 expeditiously discharged and we will perform the definitive repair once the surge of COVID-19 2 cases has abated. The most prudent course of action will be institution and hospital-system specific, but all 17 surgical practices will benefit from pursuing a deliberate approach to the period of post-COVID 18 return to normalcy that we all hope to achieve. A recent report from an acute care surgical 19 program describes a practical prioritization framework for addressing this challenge. 18 While priority of disease is the most important factor determining each patient's position in the 6 queue, we are also taking into consideration the projected length of stay in the ICU and in the 7 hospital for each patient following surgery. We are fortunate to have a large dedicated 8 cardiovascular ICU, but the ICU service is limited by number of beds and staff. To prevent 9 complete saturation of the ICU service (and the resultant inability to perform elective surgery), 10 we plan to alternate scheduling of patients with projected longer ICU stays with patients 11 expected to recover more quickly. This approach will preserve ICU throughput and allow the 12 most efficient clearance of our patient backlog. The decision-making model will be different in 13 each regional and institutional environment, but multi-disciplinary collaboration with social 14 workers, the blood bank, supply chain, and hospital staffing will be critical. Efforts to "flatten the 15 curve" are already showing effect (Figure 3) . The intended consequence of these mitigation 16 efforts is that the increase in COVID-19 patients will have a prolonged and lower peak. If this 17 strategy is successful, many regions will continue to experience resource limitations, not just in 18 the short term but for many months. An understanding of local modeling of disease burden and 19 system resources will be critical as we continue to evaluate and re-evaluate our patients who are 20 currently in limbo. Success in flattening the curve will also mean that the devastating choices 21 faced by clinicians in areas where this did not occur may be avoided. At this time we do not 22 anticipate the need to palliate patients who would otherwise be treated due to lack of beds, 23 ventilators, or PPE. We are still on the "pre-peak" part of our curve and this decision will be societies would draft such guidelines in a collaborative consensus-building manner, both to 10 minimize differences in regional decision making as well as to provide a "pandemic standard of 11 care" to protect physicians across specialties from medicolegal liability for outcomes related to 12 resource constrained decision-making. There may be a role for government intervention as well;
New York State has recently passed legislation allowing for legal protection for physicians and 14 hospital systems making difficult decisions in the face of the pandemic. Given the high 15 morbidity and mortality for untreated acute aortic syndrome, it seems clear that surgical 16 treatment should be offered whenever possible to these patients. Decision making for elective or 17 urgent aortic surgery is much more nuanced and will be best served with an institution and 18 program-specific approach. By taking these collective measures, we as a specialty can continue 19 to provide the best possible care for our patients in the context of our new shared reality. 