Corrigendum: Iatrogenic air embolism: pathoanatomy, thromboinflammation, endotheliopathy, and therapies.

[This corrects the article DOI: 10.3389/fimmu.2023.1230049.].

Iatrogenic air embolism: pathoanatomy, thromboinflammation, endotheliopathy, and therapies.

Iatrogenic vascular air embolism is a relatively infrequent event but is associated with significant morbidity and mortality. These emboli can arise in many clinical settings such as neurosurgery, cardiac surgery, and liver transplantation, but more recently, endoscopy, hemodialysis, thoracentesis, tissue biopsy, angiography, and central and peripheral venous access and removal have overtaken surgery and trauma as significant causes of vascular air embolism. The true incidence may be greater since many of these air emboli are asymptomatic and frequently go undiagnosed or unreported. Due to the rarity of vascular air embolism and because of the many manifestations, diagnoses can be difficult and require immediate therapeutic intervention. An iatrogenic air embolism can result in both venous and arterial emboli whose anatomic locations dictate the clinical course. Most clinically significant iatrogenic air emboli are caused by arterial obstruction of small vessels because the pulmonary gas exchange filters the more frequent, smaller volume bubbles that gain access to the venous circulation. However, there is a subset of patients with venous air emboli caused by larger volumes of air who present with more protean manifestations. There have been significant gains in the understanding of the interactions of fluid dynamics, hemostasis, and inflammation caused by air emboli due to in vitro and in vivo studies on flow dynamics of bubbles in small vessels. Intensive research regarding the thromboinflammatory changes at the level of the endothelium has been described recently. The obstruction of vessels by air emboli causes immediate pathoanatomic and immunologic and thromboinflammatory responses at the level of the endothelium. In this review, we describe those immunologic and thromboinflammatory responses at the level of the endothelium as well as evaluate traditional and novel forms of therapy for this rare and often unrecognized clinical condition.

Immuno-Thrombotic Complications of COVID-19: Implications for Timing of Surgery and Anticoagulation.

Early in the coronavirus disease 2019 (COVID-19) pandemic, global governing bodies prioritized transmissibility-based precautions and hospital capacity as the foundation for delay of elective procedures. As elective surgical volumes increased, convalescent COVID-19 patients faced increased postoperative morbidity and mortality and clinicians had limited evidence for stratifying individual risk in this population. Clear evidence now demonstrates that those recovering from COVID-19 have increased postoperative morbidity and mortality. These data-in conjunction with the recent American Society of Anesthesiologists guidelines-offer the evidence necessary to expand the early pandemic guidelines and guide the surgeon's preoperative risk assessment. Here, we argue elective surgeries should still be delayed on a personalized basis to maximize postoperative outcomes. We outline a framework for stratifying the individual COVID-19 patient's fitness for surgery based on the symptoms and severity of acute or convalescent COVID-19 illness, coagulopathy assessment, and acuity of the surgical procedure. Although the most common manifestation of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection is COVID-19 pneumonitis, every system in the body is potentially afflicted by an endotheliitis. This endothelial derangement most often manifests as a hypercoagulable state on admission with associated occult and symptomatic venous and arterial thromboembolisms. The delicate balance between hyper and hypocoagulable states is defined by the local immune-thrombotic crosstalk that results commonly in a hemostatic derangement known as fibrinolytic shutdown. In tandem, the hemostatic derangements that occur during acute COVID-19 infection affect not only the timing of surgical procedures, but also the incidence of postoperative hemostatic complications related to COVID-19-associated coagulopathy (CAC). Traditional methods of thromboprophylaxis and treatment of thromboses after surgery require a tailored approach guided by an understanding of the pathophysiologic underpinnings of the COVID-19 patient. Likewise, a prolonged period of risk for developing hemostatic complications following hospitalization due to COVID-19 has resulted in guidelines from differing societies that recommend varying periods of delay following SARS-CoV-2 infection. In conclusion, we propose the perioperative, personalized assessment of COVID-19 patients' CAC using viscoelastic hemostatic assays and fluorescent microclot analysis.

Tension pneumomediastinum and diffuse subcutaneous emphysema with severe acute respiratory syndrome coronavirus 2 infection requiring operative management for impending airway collapse: A case report.

Tension pneumomediastinum is a rare complication of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection that has increased in incidence with the novel coronavirus disease 2019 pandemic. Although traditionally managed with conservative measures, we present the indications and methods for the first operative management of tension pneumomediastinum with concomitant SARS-CoV-2 infection.

Liver Dysfunction Associated With In-Hospital Mortality in Adult Extracorporeal Membrane Oxygenation Support.

Extracorporeal membrane oxygenator support is a powerful clinical tool that is currently enjoying a resurgence in popularity. Wider use of extracorporeal membrane oxygenator support is limited by its significant risk profile and extreme consumption of resources. This study examines the role of markers of liver dysfunction in predicting outcomes of adult patients requiring extracorporeal membrane oxygenator support. DESIGN: Retrospective review. SETTING: Large extracorporeal membrane oxygenator center, Chicago, IL. PATIENTS: This study reports a single institution experience examining all adult patients for whom extracorporeal membrane oxygenator support was used over an 8-year period. Data were collected regarding patient demographics, details of extracorporeal membrane oxygenator support provided, laboratory data, and outcomes. Trends in liver function were examined for their ability to predict survival. INTERVENTION: Extracorporeal membrane oxygenator support, critical care. MEASUREMENTS AND MAIN RESULTS: Mean age was 50 years (range, 19-82 yr). There were 86 male patients (56.6%) and 66 female patients (43.4%). Indications for initiation of extracorporeal membrane oxygenator support included cardiac 76 patients (50.0%), respiratory 48 patients (31.6%), extracorporeal cardiopulmonary resuscitation 21 patients (13.3%), and combined cardiac/respiratory seven patients (4.6%). Mean duration of extracorporeal membrane oxygenator support was 17 days (range 1-223 d) or median 8 days (interquartile range, 4-17 d). Overall, in-hospital mortality was 56% (86/152). Forty-five percent of adult patients (68/152) surpassed at least one of the following established liver dysfunction thresholds: total bilirubin greater than 15 mg/dL, aspartate aminotransferase greater than 20× upper limit of normal, and alanine aminotransferase greater than 20× upper limit of normal. The multivariable logistic analysis yielded three significant findings associated with in-hospital mortality: highest total bilirubin greater than 15 (adjusted odds ratio = 4.40; 95% CI, 1.19-21.87; p = 0.04), age (adjusted odds ratio = 1.03; 95% CI, 1.00-1.05; p = 0.04), and highest lactate (adjusted odds ratio = 1.15; 95% CI, 1.06-1.26; p = 0.002). CONCLUSIONS: Increases in age, highest total bilirubin, and lactate all correlated with in-hospital mortality in multivariable analysis of patients requiring extracorporeal membrane oxygenator support.

Percutaneous Right Ventricular Assist Device Using the TandemHeart ProtekDuo: Real-World Experience.

BACKGROUND: Acute right ventricular (RV) failure is challenging to treat and mechanical circulatory support devices are limited. The TandemHeart ProtekDuo (THPD; TandemLife) is a novel percutaneous RV assist device that can provide 4.0 liters per minute of blood flow through venovenous extracorporeal life support. It allows venous drainage from the right atrium and reinfusion of blood into the main pulmonary artery via internal jugular vein access. We aim to provide real-world insight into disease characteristics resulting in the use of THPD for mechanical support and enhance knowledge of best practice regarding clinical management weaning and removal/exit strategies. METHODS: We retrospectively collected data of consecutive patients who received a THPD device at our center for acute RV failure between August 2015 and February 2018. RESULTS: Eleven patients were diagnosed with acute RV failure and required placement of THPD. The hospital length of stay ranged from 12 to 223 days. The average length of support ranged from 11 to 154 days. We observed complications such as stroke (18.2%), sepsis (63.6%), massive gastrointestinal bleed (45.5%), and heparin-induced thrombocytopenia (54.5%). These patients received on average 85 units of blood products. Survival was 82% at 30 days and 72% at 180 days. Six of the patients were successfully weaned from the THPD devices and 1 patient required venovenous extracorporeal life support. CONCLUSIONS: This real-world experience, despite high morbidity, continues to suggest benefits of THPD for patients with severe acute RV failure.

Extracorporeal membrane oxygenation in the management of granulomatosis with polyangiitis.

Granulomatosis with polyangiitis (GPA, also known as Wegener's granulomatosis) is a type of systematic vasculitis that primarily involves the lung and kidney. Diffuse alveolar hemorrhage (DAH) and associated acute respiratory failure are uncommon but devastating complications of GPA. Experience in using extracorporeal membrane oxygenation (ECMO) to manage DAH caused by GPA is limited. We report two GPA patients with DAH that were successfully managed using ECMO support. Examining 13 cases identified in the literature and two of our own, we observed that most patients experienced rapid deterioration in respiratory function in conjunction with a precedent respiratory infection. All 15 patients received veno-venous ECMO support. The median duration of ECMO support was 11 days (interquartile range: 7.5-20.75 days). Bleeding was the most common complication, seen in four (26.7%) cases. All patients were successfully weaned off ECMO after a median length of hospital stay of 42 days (interquartile range: 30-78 days). We demonstrated that the use of ECMO is a reasonable and effective support option in the management of GPA patients with DAH. The risk of bleeding is high but maybe reduced using a lower anticoagulation goal.

Diagnosis and Treatment of Trauma-Induced Coagulopathy by Viscoelastography.

This article explores the application of viscoelastic tests (VETs) in trauma-induced coagulopathy and trauma resuscitation. We describe the advantages of VETs over conventional coagulation tests in the trauma setting and refer to previous disciplines in which VET use has reduced blood product utilization, guided prohemostatic agents, and improved clinical outcomes such as the mortality of critically bleeding patients. We describe different VETs and provide guidance for blood component therapy and prohemostatic therapy based on specific VET parameters. Because the two most commonly used VET systems, rotational thromboelastometry and thromboelastography, use different activators and have different terminologies, this practical narrative review will directly compare and contrast these two VETs to help the clinician easily interpret either and use the interpretation to determine hemostatic integrity in the bleeding trauma patient. Finally, we anticipate the future of new viscoelastic technologies that can be used in this setting.

Hemolysis following wrap aortoplasty for Type A aortic dissection repair: Case report and review of the literature.

A Dacron wrap aortoplasty has been described as an adjunct to reduction ascending aortoplasty for the repair of Type A aortic dissections. We report a case of an uncomplicated hemiarch repair with wrap aortoplasty of the distal anastomosis which resulted in severe acute hemolysis. Despite only minimal focal graft deformation on imaging, the patient was found to have a flow gradient across the distal anastomosis, which was reduced by > 50% following release of the outer graft wrap. To our knowledge, only 29 additional cases of hemolytic anemia following aortic dissection repair have been described in the English literature. The reported mechanisms included aortic graft stenosis (50%), graft kinking (23%), external compression of the graft (20%), and a folded elephant trunk appendage (7%). The mean onset of hemolysis following aortic dissection repair occurred 32.2 ± 44.4 months after surgery, with only 16.7% of cases occurring within 2 weeks. This review details the clinical, laboratory, and imaging findings suggestive of mechanical hemolysis following aortic surgery.

Prolonged use of eptifibatide as a bridge to maintain drug-eluting stent patency in a patient receiving extracorporeal membrane oxygenation.

BACKGROUND: Venoarterial extracorporeal membrane oxygenation (VA-ECMO) has been used as a bridge to cardiac recovery in patients following a major cardiac event. There is a lack of literature surrounding prolonged use of eptifibatide and optimal dosing during ECMO. This case report describes our experience with extended durations and standard dosing of eptifibatide in the setting of ECMO. CASE: A 40-year-old male with a history of Marfan's syndrome, aortic root and ascending aortic aneurysm status post a modified Bentall with a St. Jude mechanical aortic valve conduit and hemi-Cabrol with a Dacron graft to the left main coronary artery presented with exertional chest pain and was found to have an anastomotic narrowing to the left main which occluded while awaiting surgical revision. A rescue percutaneous coronary intervention at the anastomotic site was performed. Due to hemodynamic instability, he was placed on femoral VA-ECMO. The patient was started on anticoagulation for the ECMO circuit and eptifibatide to maintain stent patency. The patient experienced several bleeding episodes for which he received supportive care, endoscopic intervention and left gastric artery embolization. Eptifibatide was maintained at standard dosing and the heparin infusion was withheld. A coronary angiogram revealed no thrombus within the Cabrol graft a patent stent previously placed at the site of the distal graft-coronary anastomosis. The patient was decannulated from ECMO and underwent coronary artery bypass grafting and division of the hemi-Cabrol graft. CONCLUSION: While eptifibatide was effective in maintaining stent patency, our patient experienced several bleeding episodes during ECMO. Thus, the risks and benefits of concurrent antiplatelet and anticoagulant therapy must be appropriately weighed in this patient population. Additionally, as the need for dual antiplatelet therapy due to coronary stent implantation is increasing, further studies are needed to validate optimal dosing of eptifibatide in patients at a high risk of bleeding during ECMO.

Delayed Retrograde Ascending Aortic Dissection After Endovascular Repair of Descending Dissection.

We report the case of a 34-year-old woman who developed delayed retrograde ascending aortic dissection after previous endovascular repair of her descending thoracic aorta. Preoperative computed tomography imaging specifically highlights the interaction of endograft springs with the dissection flap and surrounding aortic tissues. Intraoperative findings are presented for comparison and further discussion.

Repair of a complex thoracic aneurysm from relapsing polychondritis.

A 29-year-old female with a history of relapsing polychondritis (RP) and open repair of a proximal descending thoracic aneurysm presented with 2 areas of asymptomatic thoracic aortic aneurysmal dilatation. The patient returned 3 months later with symptomatic aneurysm expansion, and she underwent ascending aortic arch replacement. She subsequently underwent staged endovascular repair of the distal descending thoracic aorta. RP is a rare disorder with an incidence of 3.5 per million persons annually, 4% to 7% of whom develop aneurysmal disease. Because of the aneurysmal potential of this disease, it is important for vascular surgeons to be aware of its presentation and treatment. To our knowledge, this is the first reported case describing endovascular technique to treat such a patient.

Perioperative management of patients undergoing transmyocardial laser revascularization.

Advanced revascularization strategies continue to uncover a growing number of patients with symptomatic diffuse coronary artery disease. Transmyocardial laser revascularization (TMR) provides significant benefit in terms of improved quality of life and more complete revascularization for these difficult to treat patients when TMR is used as sole therapy or in combination with coronary artery bypass grafting. The safe clinical application of this important procedure relies on diligent perioperative management with appropriate patient selection, intraoperative care that avoids myocardial ischemia, and postoperative pain control along with expeditious reinstitution of antianginal medications. The treatment paradigms learned with the safe application of TMR should prove useful as new therapies to extend our revascularization options are developed.

Transmyocardial laser revascularization as an adjunct to coronary artery bypass grafting: a randomized, multicenter study with 4-year follow-up.

We evaluated transmyocardial laser revascularization (TMLR) with coronary artery bypass grafting (CABG) versus CABG alone for severe coronary artery disease involving 21 myocardial region unsuited for CABG. At 4 centers, 44 consecutive patients were randomized for CABG+TMLR (n = 23) or CABG alone (n = 21). Operative and in-hospital mortality and morbidity rates were monitored. Clinical status was evaluated at hospital discharge, 1 year, and 4 years. Success was characterized by relief of angina and freedom from repeat revascularization and death. Preoperatively, 20 patients (47%) were at high risk. The CABG technique, number of grafts, and target vessels were similar in both groups. Patients undergoing CABG+TMLR received 25 +/- 11 laser channels. Their < or = 30-day mortality was 13% (3/23) compared with 28% (6/21) after CABG alone (P = 0.21). There were no significant intergroup differences in the number of intraoperative or in-hospital adverse events. The follow-up period was 50.3 +/- 17.8 months for CABG alone and 48.1 +/- 16.8 months for CABG+TMLR. Both groups had substantially improved angina and functional status at 1 and 4 years, with no significant differences in cumulative 4-year mortality. The incidence of repeat revascularization was 24% after CABG alone versus none after CABG+TMLR (P < 0.05). The 4-year event-free survival rate was 14% versus 39%, respectively (P < 0.064). In conclusion, CABG+TMLR appears safe and poses no additional threat for high-risk patients. Improved overall success and repeat revascularization rates may be due to better perfusion of ischemic areas not amenable to bypass. Further studies are warranted to determine whether these trends are indeed significant.

One-year follow-up of direct myocardial gene transfer of vascular endothelial growth factor-2 using naked plasmid deoxyribonucleic acid by way of thoracotomy in no-option patients.

This phase I open label, dose-escalating study shows that gene transfer of vascular endothelial growth factor-2 naked deoxyribonucleic acid by direct myocardial injection by way of thoracotomy in patients with Canadian Cardiovascular Society class 3 or 4 angina is feasible and safe. The procedure is well tolerated, with few major adverse cardiac events at 1 year, and without complications directly related to gene expression. In this prospective, nonblinded study, the procedure is associated with clinical improvement; however, there was no angiographic evidence of angiogenesis and there is a great potential for a sham or placebo effect in the study patients. A randomized phase III trial is underway that will help determine the efficacy of vascular endothelial growth factor-2 gene transfer in "no-option" patients.

Combined fludarabine and rituximab for low grade lymphoma and chronic lymphocytic leukemia.

As both fludarabine and rituximab are active against indolent lymphoproliferative disorders, we have studied the combination of fludarabine and rituximab in patients with low-grade lymphoma and chronic lymphocytic leukemia (CLL) in phase I/II fashion. Of 33 patients enrolled, 21(63.6%) had low-grade lymphoma and 12 (36.4%) had CLL. They received fludarabine 30 mg/m2 on days 1-4 and rituximab 125, 250 or 375 mg/m2 on day 5 at intervals of 28 days to a maximum of 8 cycles. Three patients were removed from the study because of rituximab-associated anaphylaxis and four because of prolonged hematopoietic toxicity. Toxicity and responsiveness did not differ at the different dose levels of rituximab. For 29 evaluable patients, responses were seen in 82.8% and complete responses in 34.5%. Of 7 responding patients not referred for stem cell transplantation, 6 remain in complete remission at a median follow-up of 16 months (range 4-30 months). Of 13 previously untreated patients, all responded and 46.2% had a complete response. Of 16 previously treated patients, 68.5% responded and 25% had a complete response. The combination of fludarabine and rituximab has major activity and acceptable toxicity in patients with low-grade lymphoma and CLL.

Severe myxedema after cardiopulmonary bypass.

IMPLICATIONS: We report a case illustrating the serious perioperative consequences that can potentially result from failure to provide adequate thyroid hormone therapy for severe hypothyroidism before cardiac surgery.