Factors Associated with Ipsilateral Limb Ischemia in Patients Undergoing Femoral Cannulation Extracorporeal Membrane Oxygenation

Acute Vascular Complications of VA-ECMO in COVID-19 Patients. Does COVID-19 Affect the Outcome?

BACKGROUND

Extracorporeal membrane oxygenation (ECMO) through the femoral artery and vein can lead to significant vascular complications. We retrospectively studied the acute vascular complications of Veno-Arterial Extracorporeal Membrane Oxygenation (VA-ECMO) in COVID-19 patients compared to non-COVID patients during the period from January 2020 to July 2023.

RESULTS

Seventy-eight patients underwent VA-ECMO for various indications from January 2020 to July 2023. The studied patients had a mean age of 59.6 ± 6.9 years for non-COVID patients (38 patients), and 62.2 ± 7.6 years for COVID patients (40 patients), with a P = 0.268. In non-COVID patients, The baseline characteristics were similar in both groups. The primary indications for ECMO were cardiac diseases, followed by respiratory failure (78.9% vs 10.5%). Conversely, in COVID patients, respiratory failure due to COVID-19 infection was the main indication (45% vs 40%). The overall incidence of general complications, including cerebrovascular stroke, acute kidney injury, intracardiac thrombi, and wound infection, was comparable in both groups (31.6% vs 45%). The overall incidence of vascular complications in both groups was 33.3%. Ipsilateral acute lower limb ischemia occurred in 5.3% vs 10% of non-COVID and COVID patients, respectively. Thrombosis of the distal perfusion catheter (DPC) occurred in 10.5% vs 15%, respectively.

CONCLUSION

During the COVID-19 pandemic, an increasing number of patients required VA-ECMO due to associated respiratory failure. Patients undergoing VA-ECMO are at high risk of developing various vascular complications. COVID-19 significantly increases the risk of acute limb ischemia and distal perfusion catheter thrombosis in both upper and lower limbs. However, other VA-ECMO-related vascular complications are comparable between COVID-19 and non-COVID patients.

Occurrence, predictors, and management of late vascular complications following extracorporeal membrane oxygenation

OBJECTIVE

Vascular complications (VCs) associated with extracorporeal membrane oxygenation (ECMO) during index hospitalization are prevalent and associated with increased mortality. Few studies have evaluated late VCs following ECMO; this study aims to assess occurrence and management practices of late VCs following discharge.

METHODS

A retrospective single-institution review was performed of all patients surviving initial hospitalization after being cannulated for central or peripheral veno-venous (VV) or veno-arterial (VA) ECMO between January 1, 2019, and December 31, 2020. Primary outcomes were to categorize and determine the rate of late VCs. Late VCs were defined as any cannulated vessel injury resulting from ECMO cannulation presenting after discharge from index hospitalization. Analysis was conducted by cannulated vessel and stratified by VV or VA ECMO configurations.

RESULTS

A total of 229 patients were identified, of which 50.6% (n = 116) survived until discharge. Late VCs occurred in 7.8% of the surviving cohort (n = 9/116); with a median time until presentation of 150 days (interquartile range, 83-251 days). The most common late VC was infection (n = 5; 55.6%) followed by progression to limb-threatening ischemia (n = 4; 44.4%). Urgent procedures were required in 55.6% of patients (n = 5), whereas 44.4% (n = 4) were elective interventions. Interventions performed for management of late VCs included lower extremity arterial revascularization (n = 6; 66.7%), major (n = 1; 11.1%) or minor amputation (n = 1; 11.1%), and wound debridement (n = 1; 11.1%). The majority of patients presenting with late VCs had initially been cannulated for peripheral VA ECMO (n = 8; 88.9%), and one patient (11.1%) was cannulated for peripheral VV ECMO. VCs during index hospitalization were seen in 77.8% of patients (n = 7) returning with late VCs. Odds for late VCs were significantly increased in patients that had been cannulated for ECMO as part of extracorporeal cardiopulmonary resuscitation (odds ratio, 8.4; P = .016) and in cases where patients had experienced an index VC during index hospitalization (odds ratio, 19.3; P = .001).

CONCLUSIONS

Late vascular complications after peripheral ECMO cannulation are not rare, particularly after arterial cannulation. Patients should be followed closely early after surviving ECMO with wound evaluation and formal assessment of perfusion with ankle-branchial indices in the cannulated limb.

Routine Versus Selective Distal Perfusion Catheter Use in Venoarterial Extracorporeal Membrane Oxygenation

Although current studies support the use of prophylactic distal perfusion catheters (DPCs) to decrease limb ischemia in patients on venoarterial extracorporeal membrane oxygenation (VA ECMO), methods for monitoring limb ischemia differ between studies. We evaluated the safety of a selective rather than prophylactic DPC strategy at a single center with a well-established protocol for limb ischemia monitoring. Distal perfusion catheters were placed selectively if there was evidence of hypoperfusion at any point until decannulation. All patients were followed daily by vascular surgery with continuous regional saturation monitoring. Of 188 patients supported with VA ECMO, there were no significant differences in baseline characteristics between patients with upfront, delayed, and no DPC. Thirty day mortality was highest in patients with an upfront DPC (56% in the upfront DPC group, 19% in the delayed DPC group, and 22% in the no-DPC group, p < 0.001). The incidence of major bleeding, fasciotomy, and amputation in the entire cohort was 3.7%, 3.7%, and 0%, respectively. With strict adherence to a protocol for limb ischemia monitoring, a selective rather than prophylactic DPC strategy is safe and may obviate the risks of an additional arterial catheter.

Acute Compartment Syndrome in Pediatric Patients on Extracorporeal Membrane Oxygenation Support

BACKGROUND

When acute compartment syndrome (ACS) occurs in pediatric patients requiring venoarterial extracorporeal membrane oxygen (VA ECMO) support, there is little data to guide surgeons on appropriate management. The purpose of this study is to characterize the presentation, diagnosis, timeline, and outcomes of patients who developed this complication.

METHODS

This is a single-center retrospective case series of children below 19 years old on VA ECMO support who subsequently developed extremity ACS between January 2016 and December 2022. Outcomes included fasciotomy findings, amputation, mortality, and documented function at the last follow-up.

RESULTS

Of 343 patients on VA ECMO support, 18 (5.2%) were diagnosed with ACS a median 29 hours after starting ECMO. Initial cannulation sites included 8 femoral, 6 neck, and 4 central. Femoral artery cannulation was associated with an increased risk of ACS [odds ratio=6.0 (CI: 2.2 to 15), P <0.0001]. In the hospital, the mortality rate was 56% (10/18). Fourteen (78%) patients received fasciotomies a median of 1.2 hours after ACS diagnosis. Only 4 (29%) patients had all healthy muscles at initial fasciotomy, while 9 (64%) had poor muscular findings in at least 1 compartment. Patients with worse findings at fasciotomy had a significantly longer duration between ischemia onset and ACS diagnosis. Patients required a median of 1.5 additional procedures after fasciotomy, and only 1 (7%) developed a surgical site infection. Of the 7 surviving fasciotomy patients, 2 required amputations, 3 developed an equinus contracture, 1 developed foot drop, and 3 had no ACS-related deficits. Four patients did not receive fasciotomies: 3 were deemed too ill and later died, and 1 was diagnosed too late to benefit. The only surviving nonfasciotomy patient required bilateral amputations.

CONCLUSIONS

Pediatric ECMO-associated ACS is not exclusive to patients with femoral artery cannulation. The majority of fasciotomy patients were diagnosed with ACS after muscle necrosis had already started. We were unable to definitively conclude whether fasciotomies provide better outcomes. There is a need for increased awareness and earlier recognition of this rare yet potentially devastating complication.

LEVEL OF EVIDENCE

Level IV-retrospective case series.

Use of Extracorporeal Membrane Oxygenation for Primary Graft Dysfunction After Cardiac Transplantation: Results of an A Priori Ventless Approach

Primary graft dysfunction (PGD) after cardiac transplantation is a devastating complication with increasing frequency lately in the setting of donation after circulatory death (DCD). Severe PGD is commonly treated with extracorporeal membrane oxygenation (ECMO) using central or peripheral cannulation. We retrospectively reviewed the outcomes of PGD after cardiac transplantation requiring ECMO support at our center from 2015 to 2020, focused on our now preferential approach using peripheral cannulation without a priori venting. During the study period, 255 patients underwent heart transplantation at our center and 26 (10.2%) of them required ECMO for PGD. Of 24 patients cannulated peripherally 19 (79%) were alive at 30 days and 17 (71%) 1 year after transplant; two additional patients underwent central ECMO cannulation due to unfavorable size of femoral vessels and concern for limb ischemia. Successful decannulation with full graft function recovery occurred in 22 of 24 (92%) patients cannulated peripherally. Six of them had an indwelling intra-aortic balloon pump placed before the transplantation. None of the other 18 patients received a ventricular vent. In conclusion, the use of an a priori peripheral and ventless ECMO approach in patients with PGD after heart transplant is an effective strategy associated with high rates of graft recovery and survival.

Bilateral Femoral Cannulation Is Associated With Reduced Severe Limb Ischemia-Related Complications Compared With Unilateral Femoral Cannulation in Adult Peripheral Venoarterial Extracorporeal Membrane Oxygenation: Results From the Extracorporeal Life Support Registry

OBJECTIVES

Peripheral venoarterial extracorporeal membrane oxygenation (ECMO) with femoral access is obtained through unilateral or bilateral groin cannulation. Whether one cannulation strategy is associated with a lower risk for limb ischemia remains unknown. We aim to assess if one strategy is preferable.

DESIGN

A retrospective cohort study based on the Extracorporeal Life Support Organization registry.

SETTING

ECMO centers worldwide included in the Extracorporeal Life Support Organization registry.

PATIENTS

All adult patients (≥ 18 yr) who received peripheral venoarterial ECMO with femoral access and were included from 2014 to 2020.

INTERVENTIONS

Unilateral or bilateral femoral cannulation.

MEASUREMENTS AND MAIN RESULTS

The primary outcome was the occurrence of limb ischemia defined as a composite endpoint including the need for a distal perfusion cannula (DPC) after 6 hours from implantation, compartment syndrome/fasciotomy, amputation, revascularization, and thrombectomy. Secondary endpoints included bleeding at the peripheral cannulation site, need for vessel repair, vessel repair after decannulation, and in-hospital death. Propensity score matching was performed to account for confounders. Overall, 19,093 patients underwent peripheral venoarterial ECMO through unilateral ( n = 11,965) or bilateral ( n = 7,128) femoral cannulation. Limb ischemia requiring any intervention was not different between both groups (bilateral vs unilateral: odds ratio [OR], 0.92; 95% CI, 0.82-1.02). However, there was a lower rate of compartment syndrome/fasciotomy in the bilateral group (bilateral vs unilateral: OR, 0.80; 95% CI, 0.66-0.97). Bilateral cannulation was also associated with lower odds of cannulation site bleeding (bilateral vs unilateral: OR, 0.87; 95% CI, 0.76-0.99), vessel repair (bilateral vs unilateral: OR, 0.55; 95% CI, 0.38-0.79), and in-hospital mortality (bilateral vs unilateral: OR, 0.85; 95% CI, 0.81-0.91) compared with unilateral cannulation. These findings were unchanged after propensity matching.

CONCLUSIONS

This study showed no risk reduction for overall limb ischemia-related events requiring DPC after 6 hours when comparing bilateral to unilateral femoral cannulation in peripheral venoarterial ECMO. However, bilateral cannulation was associated with a reduced risk for compartment syndrome/fasciotomy, lower rates of bleeding and vessel repair during ECMO, and lower in-hospital mortality.

What Factors Are Associated With Arterial Line-Related Limb Ischemia in Patients on Extracorporeal Membrane Oxygenation? A Single-Center Retrospective Cohort Study

OBJECTIVES

The primary purpose of this study was to identify factors associated with the development of arterial line-related limb ischemia in patients on extracorporeal membrane oxygenation (ECMO). The authors also sought to characterize and report the outcomes of patients who developed arterial line-related limb ischemia.

DESIGN

Retrospective cohort study.

SETTING

A single academic tertiary referral ECMO center.

PARTICIPANTS

Consecutive patients who were treated with ECMO over 6 years.

INTERVENTIONS

Use of arterial line.

MEASUREMENTS AND MAIN RESULTS

A total of 278 consecutive ECMO patients were included, with 19 (7%) patients developing arterial line-related limb ischemia during the ECMO run. Postcannulation Sequential Organ Failure Assessment (SOFA) (adjusted odds ratio [aOR] 1.20, 95% CI 1.08-1.32), Acute Physiology and Chronic Health Evaluation-II (aOR 0.84, 95% CI 0.74-0.95), and adjusted Vasopressor Dose Equivalence (aOR 1.03, 95% CI 1.01-1.05) scores were independently associated with the development of arterial line-associated limb ischemia. A SOFA score of ≥17 at the time of ECMO cannulation had an 80% sensitivity and 87% specificity for predicting arterial line-related limb ischemia.

CONCLUSIONS

Arterial line-related limb ischemia is much more common in ECMO patients than in the typical intensive care unit setting. The SOFA score may be useful in identifying which patients may be at risk for arterial line-related limb ischemia. As this was a single-center retrospective study, these results are inherently exploratory, and prospective multicenter studies are necessary to validate these results.

Lower Limb Ischemia in Surgical Femoral Veno-Arterial Extracorporeal Membrane Oxygenation

OBJECTIVES

To analyze the incidence, clinical impact on survival, and risk factors of lower limb ischemia (LLI) of surgical peripheral femoral venoarterial extracorporeal membrane oxygenation (VA ECMO) in the current era.

DESIGN

A retrospective analysis of the authors' institutional database of VA ECMO was performed. Patients were divided into 2 groups according to the occurrence of LLI. The primary endpoint was survival to hospital discharge. Risk factors of LLI were searched with multivariate analyses.

SETTING

University hospital.

PARTICIPANTS

Adult patients receiving peripheral VA ECMO for refractory cardiogenic shock and cardiac arrest.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

From January 2018 to December 2021, 188 patients (mean age: 52.0 ± 14.1 years; 63.8% male, 36.2% female) received peripheral VA ECMO. Male sex was more prevalent in the group without LLI (65.9% v 33.3%; p = 0.031). Twelve (6.4%) patients developed LLI during VA ECMO support (n = 6) or after VA ECMO removal (n = 6). Survival to hospital discharge was not statistically different between patients with and without LLI (50.0% v 48.3%; p = 0.571). Female sex patients were at increased risk for LLI (odds ratio 4.38, 95% CI 1.21-15.81; p = 0.024).

CONCLUSIONS

Peripheral femoral VA ECMO through a surgical approach is associated with a low LLI rate, which does not increase the risk of in-hospital mortality. The female sex is an independent risk factor for LLI.

Is Fasciotomy Associated With Increased Mortality in Extracorporeal Cardiopulmonary Resuscitation?

Our primary objective was to identify if fasciotomy was associated with increased mortality in patients who developed acute compartment syndrome (ACS) on extracorporeal cardiopulmonary resuscitation (ECPR). Additionally, we sought to identify any additional risk factors for mortality in these patients and report the amputation-free survival following fasciotomy. We retrospectively reviewed adult ECPR patients from the Extracorporeal Life Support Organization registry who were diagnosed with ACS between 2013 and 2021. Of 764 ECPR patients with limb complications, 127 patients (17%) with ACS were identified, of which 78 (63%) had fasciotomies, and 14 (11%) had amputations. Fasciotomy was associated with a 23% rate of amputation-free survival. There were no significant differences in demographics or baseline laboratory values between those with and without fasciotomy. Overall, 88 of 127 (69%) patients with ACS died. With or without fasciotomy, the mortality of ACS patients was similar, 68% vs. 71%. Multivariable logistic regression demonstrated that body mass index (BMI; adjusted odds ratio [aOR] = 1.22, 95% confidence interval [CI] = 1.01-1.48) and 24 hour mean blood pressure (BP; aOR = 0.93, 95% CI = 0.88-0.99) were independently associated with mortality. Fasciotomy was not an independent risk factor for mortality (aOR = 0.24, 95% CI = 0.03-1.88). The results of this study may help guide surgical decision-making for patients who develop ACS after ECPR. However, the retrospective nature of this study does not preclude selection bias in patients who have received fasciotomy. Thus, prospective studies are necessary to confirm these findings.

Risk factors for lower extremity vascular complications in adult patients on veno-arterial extracorporeal membrane oxygenation

OBJECTIVE

Utilization of veno-arterial extracorporeal membrane oxygenation (VA-ECMO) has increased significantly over the last decade. Prior studies have reported worse mortality for patients with vascular complications on VA-ECMO; however, these were limited by small sample size. The purpose of this study is to investigate predictive risk factors for vascular complications in VA-ECMO patients and their potential impact on mortality.

METHODS

Patients who underwent peripheral VA-ECMO from January 2011 to December 2021 were identified. Primary outcomes were lower extremity vascular complications and in-hospital mortality. Multivariate stepwise logistic regression models were used to identify predictors of vascular complications and in-hospital mortality.

RESULTS

A total of 605 VA-ECMO patients (25% female) were identified. The mean age was 56.3 ± 13 years, and 56 (10.4%) were black. In-hospital mortality was 63.8% (n = 386), and VA-ECMO ipsilateral vascular complications occurred in 72 patients (11.9%). Vascular surgical interventions (thromboembolectomy, fasciotomies, amputation, and surgical management of cannula bleeding) were required in 30 patients (41.7%). Same-side arterial and venous cannulas, cannula size, and absence of distal perfusion cannula did not increase risk of vascular complication. Multivariate analysis identified age (odds ratio, 0.948; 95% confidence interval, 0.909-0.988; P = .0116) and pre-existing peripheral arterial disease (odds ratio, 3.489; 95% confidence inteval, 1.146-10.624; P = .0278) as independent predictors of need for vascular surgery interventions. The mortality rate of patients who developed vascular complications was not significantly different compared with the mortality rate of those who did not develop vascular complications (61% vs 64%; P = .92).

CONCLUSIONS

This study represents one of the largest series to date of lower extremity vascular outcomes in patients undergoing VA-ECMO. Our results confirm the high mortality rate associated with VA-ECMO; however, vascular complications did not represent a risk factor for mortality as previously reported. Same-sided VA-ECMO cannulas, cannula size, and the presence or absence of distal perfusion cannula did not predict vascular complications. Increasing age and presence of peripheral arterial disease are independent predictors of need for vascular surgery intervention in patients on VA-ECMO.

Acute Limb Ischaemia during ECMO Support: A 6-Year Experience

The use of veno-arterial extracorporeal membrane oxygenation (VA-ECMO) for cardiogenic shock is rising. Acute limb ischaemia remains one of the main complications after ECMO initiation. We analysed 104 patients from our databank from January 2015 to December 2021 who were supported with mobile ECMO therapy. We aimed to identify the impact of acute limb ischaemia on short-term outcomes in patients placed on ECMO in our institution. The main indication for ECMO therapy was left ventricular (LV) failure with cardiogenic shock (57.7%). Diameters of arterial cannulas (p = 0.365) showed no significant differences between both groups. Furthermore, concomitant intra-aortic balloon pump (IABP, p = 0.589) and Impella (p = 0.385) implantation did not differ significantly between both groups. Distal leg perfusion was established in approximately 70% of patients in two groups with no statistically significant difference (p = 0.960). Acute limb ischaemia occurred in 18.3% of cases (n = 19). In-hospital mortality was not significantly different (p = 0.799) in both groups. However, the bleeding rate was significantly higher (p = 0.005) in the limb ischaemia group compared to the no-limb ischaemia group. Therefore, early diagnosis and prevention of acute limb ischaemia might decrease haemorrhage complications in patients during ECMO therapy.

Continuous near-infrared reflectance spectroscopy monitoring to guide distal perfusion can minimize limb ischemia surgery for patients requiring femoral venoarterial extracorporeal life support

BACKGROUND

Patients requiring femoral venoarterial (VA) extracorporeal life support (ECLS) are at risk of distal lower limb hypoperfusion and ischemia of the cannulated leg. In the present study, we evaluated the effect of using continuous noninvasive lower limb oximetry with near-infrared reflectance spectroscopy (NIRS) to detect tissue hypoxia and guide distal perfusion catheter (DPC) placement on the rates of leg ischemia requiring surgical intervention.

METHODS

We performed a retrospective analysis of patients who had undergone femoral VA-ECLS at our institution from 2010 to 2014 (pre-NIRS era) and 2017 to 2021 (NIRS era). Patients who had undergone cannulation during the 2015 to 2016 transition era were excluded. The baseline characteristics, short-term outcomes, and ischemic complications requiring surgical intervention (eg, fasciotomy, thrombectomy, amputation, exploration) were compared across the two cohorts.

RESULTS

Of the 490 patients included in the present study, 141 (28.8%) and 349 (71.2%) had undergone cannulation before and after the routine use of NIRS to direct DPC placement, respectively. The patients in the NIRS cohort had had a greater incidence of hyperlipidemia (53.7% vs 41.1%; P = .015) and hypertension (71.4% vs 60%; P = .020) at baseline, although they were less likely to have been supported with an intra-aortic balloon pump before ECLS cannulation (26.9% vs 37.6%; P = .026). These patients were also more likely to have experienced cardiac arrest (22.9% vs 7.8%; P ≤ .001) and a pulmonary cause (5.2% vs 0.7%; P = .04) as an indication for ECLS, with ECLS initiated less often for acute myocardial infarction (15.8% vs 34%; P ≤ .001). The patients in the NIRS cohort had had a smaller arterial cannula size (P ≤ .001) and a longer duration of ECLS support (5 vs 3.25 days; P ≤ .001) but significantly lower rates of surgical intervention for limb ischemia (2.6% vs 8.5%; P = .007) despite comparable rates of DPC placement (49.1% vs 44.7%; P = .427), with only two patients (1.1%) not identified by NIRS ultimately requiring surgical intervention.

CONCLUSIONS

The use of a smaller arterial cannula (≤15F) and continuous NIRS monitoring to guide selective insertion of DPCs could be a valid and effective strategy associated with a reduced incidence of ischemic events requiring surgical intervention.

Extracorporeal membrane oxygenation for cardiogenic shock: a meta-analysis of mortality and complications

BACKGROUND

Venoarterial extracorporeal membrane oxygenation (va-ECMO) is an advanced life support for critically ill patients with refractory cardiogenic shock. This temporary support bridges time for recovery, permanent assist, or transplantation in patients with high risk of mortality. However, the benefit of this modality is still subject of discussion and despite the continuous development of critical care medicine, severe cardiogenic shock remains associated with high mortality. Therefore, this work aims to analyze the current literature regarding in-hospital mortality and complication rates of va-ECMO in patients with cardiogenic shock.

METHODS

We conducted a systematic review and meta-analysis of the most recent literature to analyze the outcomes of va-ECMO support. Using the PRISMA guidelines, Medline (PubMed) and Scopus (Elsevier) databases were systematically searched up to May 2022. Meta-analytic pooled estimation of publications variables was performed using a weighted random effects model for study size.

RESULTS

Thirty-two studies comprising 12756 patients were included in the final analysis. Between 1994 and 2019, 62% (pooled estimate, 8493/12756) of patients died in the hospital. More than one-third of patients died during ECMO support. The most frequent complications were renal failure (51%, 693/1351) with the need for renal replacement therapy (44%, 4879/11186) and bleeding (49%, 1971/4523), bearing the potential for permanent injury or death. Univariate meta-regression analyses identified age over 60 years, shorter ECMO duration and presence of infection as variables associated with in-hospital mortality, while the studies reporting a higher incidence of cannulation site bleeding were unexpectedly associated with a reduced in-hospital mortality.

CONCLUSIONS

Extracorporeal membrane oxygenation is an invasive life support with a high risk of complications. We identified a pooled in-hospital mortality of 62% with patient age, infection and ECMO support duration being associated with a higher mortality. Protocols and techniques must be developed to reduce the rate of adverse events. Finally, randomized trials are necessary to demonstrate the effectiveness of va-ECMO in cardiogenic shock.

Impact factors of POCUS-guided cannulation for peripheral venoarterial extracorporeal membrane oxygenation: One single-center retrospective clinical analysis

We aimed to evaluate associated factors for point-of-care ultrasound (POCUS)-guided percutaneous catheterization for venoarterial extracorporeal membrane oxygenation (VA-ECMO). VA-ECMO cases from March 2018 to October 2020 in Department of Intensive Care Unit, Binhaiwan Central Hospital of Dongguan, were enrolled. Clinical data, outcomes, and complications were recorded and summarized. Fifty-nine cases were enrolled, among which 88.1% succeeded in POCUS-guided catheterization via Seldinger technique, whereas 59.3% succeeded at the first puncture. Results showed that artery diameter and times of arterial punctures were independent associated factors for Seldinger puncture (P = .018, odds ratio [OR] = 23.374, 95% confidence interval [CI] = 1.706-320.270; P = .031, OR = 145.098, 95% CI = 1.592-13220.980), and artery diameter and cardiac ejection fraction value (≥30%/<30%) were independent associated factors for first puncture (P = .044, OR = 1.622, 95% CI = 1.014-2.596; P = .013, OR = 5.565, 95% CI = 1.441-21.488). For extracorporeal cardiopulmonary resuscitation patients, artery diameter was independent associated factor for Seldinger puncture (P = .022, OR = 2.070, 95% CI = 1.110-3.858), and cardiac ejection fraction value (≥30%/<30%) was independent associated factor for first puncture (P = .007, OR = 9.533, 95% CI = 1.847-49.204). Thirteen patients (22.0%) had local hemorrhage post puncture, 8 patients (13.6%) presented distal limb arterial ischemia, and 8 patients (13.6%) suffered puncture-related thrombosis. Vasoactive Inotropic Score was found to be independent associated factor for local hemorrhage (P = .039, OR = 0.994, 95% CI = 0.988-1.000), and the Acute Physiology and Chronic Health Evaluation II score was independent associated factor for thrombosis (P = .025, OR = 0.935, 95% CI = 0.882-0.992). Diabetes and cardiopulmonary resuscitation time before catheterization were independent factors for distal limb ischemia (P = .026, OR = 220.774, 95% CI = 1.905-25591.327; P = .017, OR = 1.054, 95% CI = 1.009-1.101). POCUS-guided percutaneous catheterization via Seldinger technique can be the first choice for VA-ECMO cannulation, especially for a team without angiotomy qualifications. Before cannulation, evaluating the target artery and heart function by ultrasound can help predict outcome of catheterization. Assessing risk factors (diabetes, cardiopulmonary resuscitation time before catheterization, Vasoactive Inotropic Score, the Acute Physiology and Chronic Health Evaluation II score) is helpful for prevention and treatment of complications.

Limb Ischemia Complications of Veno-Arterial Extracorporeal Membrane Oxygenation

Background

This study aimed to summarize and analyse the risk factors, clinical features, as well as prevention and treatment of limb ischemia complications in patients on veno-arterial extracorporeal membrane oxygenation (V-A ECMO).

Methods

We retrospectively analyzed 179 adult patients who had undergone V-A ECMO support in the Cardiac Care Unit of the First Hospital of Lanzhou University between March 2019 and December 2021. Patients were divided into the limb ischemia group (LI group) and the non-limb ischemia group (nLI group) according to whether limb ischemia occurred on the ipsilateral side of femoral artery cannulation. In the LI group, patients were salvaged with a distal perfusion cannula (DPC) according to each patient's clinical conditions. The baseline data and ECMO data were compared between the two groups, and risk factors for limb ischemia complications were screened using multiple logistic regression analysis.

Results

Overall, 19 patients (10.6%) had limb ischemia complications, of which 5 (2.8%) were improved after medication adjustment, 12 (8.4%) were salvaged with a DPC, and 2 had undergone surgical intervention. There were significant differences in terms of Extracorporeal Cardiopulmonary Resuscitation (ECPR), Intra-aortic balloon pump (IABP), peak vasoactive-inotropic score (VIS) within 24 h after ECMO (VIS-max), Left ventricular ejection fraction (LVEF), weaning from ECMO, and discharge rate between the two groups. ECPR, IABP, and VIS-max in the LI group were significantly higher than those in the nLI group, whereas weaning from ECMO, discharge rate, and LVEF were significantly lower in the LI group compared to those in the nLI group. Furthermore, multiple logistic regression analysis revealed that diabetes [odds ratio (OR) = 4.338, 95% confidence interval (CI): 1.193–15.772, P = 0.026], IABP (OR = 1.526, 95% CI: 1.038–22.026, P = 0.049) and VIS-max (OR = 1.054, 95% CI: 1.024–1.085, P < 0.001) were independent risk factors for limb ischemia complications in patients who underwent V-A ECMO.

Conclusion

Diabetes, prevalence of IABP and VIS-max value in analyzed groups were independent risk factors for predicting limb ischemia complications in patients who underwent V-A ECMO. The cannulation strategy should be optimized during the establishment of V-A ECMO, and limb ischemia should be systematically evaluated after ECMO establishment. A DPC can be used as a salvage intervention for the complications of critical limb ischemia.

Risk factors for severe lower extremity ischemia following venoarterial extracorporeal membrane oxygenation: an analysis using a nationwide inpatient database

Objectives

Venoarterial extracorporeal membrane oxygenation is increasingly being used as a life-saving modality in critically ill patients. Despite its necessity, severe lower extremity ischemia associated with venoarterial extracorporeal membrane oxygenation remains a potentially devastating complication. We aimed to investigate the incidence and risk factors for severe lower extremity ischemia requiring fasciotomy or amputation following venoarterial extracorporeal membrane oxygenation.

Methods

All patients who received venoarterial extracorporeal membrane oxygenation during hospitalization were identified in a Japanese national inpatient database from July 1, 2010 to March 31, 2018. The primary outcome was occurrence of severe lower extremity ischemia that required fasciotomy or amputation. We used cause-specific proportional hazard models to examine the associations between potential risk factors and outcomes. We also performed a competing-risk analysis to estimate the cause-specific HR for severe lower extremity ischemia using a multivariable competing-risk Cox proportional hazard model with adjustment for potential risk factors.

Results

A total of 29 231 patients who underwent venoarterial extracorporeal membrane oxygenation during hospitalization were identified. Of these, 98 patients (0.3%) had lower extremity ischemia requiring fasciotomy or amputation. The young group (≤18 years) had a significantly higher proportion of severe lower extremity ischemia cases than the adult (19-59 years) and elderly (≥60 years) groups (1.4%, 0.5%, and 0.2%, respectively; p<0.001). In a multivariable competing-risk Cox proportional hazards regression model, younger age (HR 3.06; 95% CI 1.33 to 7.02; p<0.008) and consciousness disturbance on admission (HR 2.53; 95% CI 1.60 to 3.99; p<0.001) were significantly associated with higher likelihood of severe lower extremity ischemia.

Conclusion

In this study using a nationwide database, younger age and consciousness disturbance on admission were associated with higher risk of severe lower extremity ischemia following venoarterial extracorporeal membrane oxygenation.

Level of evidence

Level Ⅲ-prognostic and epidemiological.

Strategies to reduce limb ischemia in peripheral venoarterial extracorporeal membrane oxygenation: A systematic review and Meta-analysis

Venoarterial extracorporeal membrane oxygenation (VA-ECMO) provides cardiovascular and respiratory support for patients in cardiogenic shock; yet, complications are a frequent source of morbidity and mortality. Limb ischemia can be potentially mitigated by limp perfusion protection strategies (LPPS). We performed a systematic review and meta-analysis to evaluate the safety and efficacy of two LPPS in patients treated with peripheral VA-ECMO - prophylactic insertion of a distal perfusion catheter (DPC) and small bore (<17 Fr) arterial return cannula. Among 22 included studies, limb ischemia was reduced in patients receiving a small arterial cannula (OR 0.40, 95% CI 0.24-0.65; p < 0.001) and in patients receiving a prophylactic DPC (OR 0.31, 95% CI 0.21-0.47; p < 0.001). Mortality was not significantly reduced with either a small arterial cannula (OR 0.70, 95% CI 0.23-2.18; p = 0.54) or prophylactic DPC strategy (OR 0.89, 95% CI 0.67-1.17; p = 0.40). As such, prophylactic insertion of a DPC or smaller bore arterial return cannula appear to reduce the risk of lower limb ischemia in this analysis. Further data are needed to confirm these findings. Registration: Registered in PROSPERO Database (Registration CRD42020215677).

Extracorporeal Membrane Oxygenation for Pregnant and Postpartum Patients

Extracorporeal membrane oxygenation (ECMO) has seen increasing use for critically ill pregnant and postpartum patients over the past decade. Growing experience continues to demonstrate the feasibility of ECMO in obstetric patients and attest to its favorable outcomes. However, the interaction of pregnancy physiology with ECMO life support requires careful planning and adaptation for success. Additionally, the maintenance of fetal oxygenation and perfusion is essential for safely continuing pregnancy during ECMO support. This review summarizes the considerations for use of ECMO in obstetric patients and how to address these concerns.

Percutaneous angio-guided versus surgical veno-arterial ECLS implantation in patients with cardiogenic shock or cardiac arrest

BACKGROUND

Veno-arterial Extracorporeal Life Support (V-A ECLS) has gained increasing place into the management of patients with refractory cardiogenic shock or cardiac arrest. Both surgical and percutaneous approach can be used for cannulation, but percutaneous approach has been associated with fewer complications. Angio-guided percutaneous cannulation and decannulation may further decrease the rate of complication. We aimed to compare outcome and complication rates in patients supported with V-A ECLS through percutaneous angio-guided versus surgical approach.

METHODS

We included all patients with emergent peripheral femoro-femoral V-A ECLS implantation for refractory cardiogenic shock or cardiac arrest in our center from March 2018 to March 2021. Survival and major complications (major bleeding, limb ischemia and groin infection) rates were compared between the percutaneous angio-guided and the surgical groups.

RESULTS

One hundred twenty patients received V-A ECLS, 59 through surgical approach and 61 through angio-guided percutaneous approach. Patients' baseline characteristics and severity scores were equally balanced between the 2 groups. Thirty-day mortality was not significantly different between the 2 approaches. However, angio-guided percutaneous cannulation was associated with fewer major vascular complications (42% vs. 11%, p > 0.0001) and a higher rate of V-A ECLS decannulation. In multivariate analysis, percutaneous angio-guided implantation of V-A ECLS was independently associated with a lower probability of major complications.

CONCLUSION

Compared to surgical approach, angio-guided percutaneous V-A ECLS implantation is associated with fewer major vascular complications. Larger studies are needed to confirm those results and address their impact on mortality.

Double Distal Perfusion Catheters for Severe Limb Ischemia on the IABP Side in Patients Who Received Femoro-Femoral VA-ECMO With IABP

Background: Limited research is available on the pattern of double distal perfusion catheters in patients on venoarterial extracorporeal membrane oxygenation (VA-ECMO) with an intra-aortic balloon pump(IABP). Here, we compared the outcomes of a double distal perfusion catheter and conventional treatment in patients who received VA-ECMO with IABP and had severe lower limb ischemia on the IABP side.

Methods: We reviewed the data of 15 adult patients with postcardiotomy cardiogenic shock who received VA-ECMO via femoral cannulation combined with an IABP in the contralateral artery that was complicated with severe acute limb ischemia (ALI) on the same side as the IABP between January 2004 and December 2016. Patients underwent symptomatic treatment (conventional group, n = 9) and double distal perfusion catheterization treatment (DDPC group, n = 6). ALI was monitored using near-infrared spectroscopy placed on both calves after double distal perfusion catheters. The outcomes were compared.

Results: All 6 patients who underwent double distal perfusion catheters were successfully decannulated without the development of osteofascial compartment syndrome, amputation, or bleeding and infection of the double distal perfusion catheters. The number of patients who weaned from extracorporeal membrane oxygenation successfully in the DDPC and conventional groups was 6 (100%) and 3 (33%, p = 0.028), respectively. The in-hospital mortality rates were 17% and 89% for the DDPC and conventional groups, respectively (p = 0.011).

Conclusions: DDPC can be considered a strategy for severe limb ischemia on the IABP side in patients who received femoro-femoral VA-ECMO with IABP.

Implantation of durable left ventricular assist device in patient with postmyocardial infarction ventricular septal defect

Ventricular septal defect (VSD) is a severe complication of myocardial infarction (MI) with a high mortality rate. We report a case of a large post-MI VSD treated with percutaneous venoarterial extracorporeal membrane oxygenation (VA-ECMO) to restore hemodynamic stability and to avoid surgery in the acute setting. VSD closure with endoventricular patch and implantation of biventricular assist device (BiVAD) was arranged sixteen days after MI. Because of no signs of myocardial recovery, implantation of durable left ventricular assist device (LVAD) as a bridge to transplant was provided, leaving right ventricular assist device (RVAD) to right ventricle recovery. RVAD was explanted 18 days after durable LVAD placement and the patient was discharged home two months after MI. The use of durable LVAD is a unique solution that can be applied in selected patients with MI-VSD and heart failure.

Vascular Complications of Extracorporeal Membrane Oxygenation: A Systematic Review and Meta-Regression Analysis

OBJECTIVES

Perform a systematic review and meta-analysis of vascular complications associated with extracorporeal membrane oxygenation and identify prognostic and predictive factors.

DATA SOURCES

Systematic search for publications reporting vascular complications on extracorporeal membrane oxygenation, published from 1972 to January 31, 2020, was conducted via PubMed, Scopus, and Embase.

STUDY SELECTION

Of 4,076 references screened, 47 studies with 6,583 patients were included in final analyses. Studies with fewer than 10 patients were excluded.

DATA EXTRACTION

Relevant data, including demographics, comorbidities, extracorporeal membrane oxygenation and cannulation characteristics, occurrence rates of early and late vascular complications, patient outcomes, and use of distal perfusion cannula, were extracted from selected articles into an excel sheet specifically designed for this review.

DATA SYNTHESIS

Random-effects meta-analyses and meta-regression analyses were undertaken. Overall pooled estimate of vascular complications in our meta-analysis was 29.5% (95% CI, 23.6-35.9%). Two-thousand three-hundred forty-seven vascular complications in 6,124 venoarterial extracorporeal membrane oxygenation patients compared with 95 in 459 venovenous extracorporeal membrane oxygenation patients (odds ratio, 2.35; 95% CI, 1.87-2.96; p < 0.0001) were analyzed. Successful weaning off extracorporeal membrane oxygenation occurred in 60.6% of pooled patients; 46.2% were eventually discharged. Pooled prevalences of vascular complications like significant bleeding, limb ischemia, and cannula site bleeding were 15.4% (95% CI, 8.6-23.7%), 12.6% (95% CI, 10.0-15.5%), and 12.6% (95% CI, 9.6-18.5%), respectively. Meta-analysis showed that the use of distal perfusion cannula was associated with lower odds of limb ischemia (odds ratio, 1.93; 95% CI, 1.17-2.47; p = 0.03) Meta-regression showed that male sex, smoking, advanced age, and comorbidities contributed to higher in-hospital mortality, while distal perfusion cannula was protective.

CONCLUSIONS

Nearly a third of patients on extracorporeal membrane oxygenation develop vascular complications; elderly males with comorbidities appear vulnerable. The use of distal perfusion cannulas caused significant reduction in limb ischemia and mortality.

Peripheral vascular complications following totally endoscopic cardiac surgery

Background

Clinical application of minimally invasive cardiac surgery has increased annually. Cardiopulmonary bypass is established by peripheral cannulation during minimally invasive cardiac surgery. The methodology of peripheral cannulation has unique characteristics, which have associated risks and complications. Few studies have been conducted on this topic. In this study, we focused on complications of peripheral cannulation in totally endoscopic cardiac surgery.

Methods

Patients who underwent totally endoscopic cardiac surgery with cardiopulmonary bypass established by peripheral cannulation at our institution between January 2019 and June 2020 were reviewed. Specific cannulation strategies and related cannulation complications were noted.

Results

One hundred forty-eight patients underwent totally endoscopic cardiac surgery. One hundred forty-eight cannulations were performed in the femoral artery and vein, and eleven were performed in the internal jugular vein (combined with the femoral vein). The median size of the femoral artery cannula was 22Fr, and that of the venous canula was 24Fr. One patient died of retroperitoneal haematoma due to femoral artery injury. Three patients had postoperative lower limb oedema. One patient had a postoperative diagnosis of femoral vein thrombosis.

Conclusions

Different from cannulation in patients with aortic dissection and aneurysms, femoral artery cannulation is safe in totally endoscopic cardiac surgery. Venous cannulation is characterized by a large-bore venous cannula and a short period of use. There are few reports about complications of venous cannulation. The main complication in this study was mechanical injury, and the key to preventing this injury is meticulous manipulation during surgery.

Acute vascular complications of femoral veno-arterial ECMO: a single-centre retrospective study

Background

Femoral arterial cannulation to initiate veno-arterial ECMO may result in ipsilateral limb ischemia due to reduced distal blood flow below the insertion point of the cannula. We retrospectively studied adult patients supported with femoral VA-ECMO for cardiogenic shock between 2015 and 2019 at our tertiary care hospital.

Results

The study included 65 adult patients supported with femoral VA-ECMO for refractory cardiogenic shock. The studied patients had a mean age of 37.9 ± 14.87 years, mostly males (70.8%), a mean BSA of 1.77 ± 0.27 m², and a mean BMI of 26.1 ± 6.7 kg/m². Twenty-one (32.3%) patients developed acute lower limb ischemia. The patients who developed acute limb ischemia had significantly frequent AKI (< 0.001) without significant use of haemodialysis (p = 0.07) and longer ICU stay (p = 0.028) compared to the patients without limb ischemia. The hospital mortality occurred in 29 (44.6%) patients without significant difference between the patients with and without acute limb ischemia. The occurrence of acute limb ischemia was significantly correlated with failed percutaneous cannulation (p = 0.039), while there was no significant statistical correlation between the cut-down technique and occurrence of limb ischemia (p = 0.053). The occurrence of femoral cannulation site bleeding was significantly correlated with failed percutaneous cannulation (p = 0.001) and cut-down technique (p = 0.001).

Conclusion

Acute vascular complications are frequent after femoral VA-ECMO. Failed percutaneous femoral cannulation has been, in this study, identified as the most important risk factor for acute limb ischemia and cannulation site bleeding. A careful approach during femoral cannulation is recommended to prevent occurrence of acute limb ischemia and femoral cannulation site bleeding.

Meta-Analysis of the Effect of Vascular Complications on Mortality in Patients Undergoing Femoral Venoarterial Extracorporeal Membrane Oxygenation

BACKGROUND

Extracorporeal membrane oxygenation (ECMO) has become an accepted treatment modality in the management of select patients with cardiopulmonary failure. As a result, its use has increased significantly over the past decade. However, the effect of complications on mortality is not clearly established. We performed a comprehensive, up-to-date meta-analysis of peer-reviewed literature focusing on the effect of vascular complications (VCs) on the survival of patients receiving venoarterial ECMO (VA-ECMO) with femoral cannulation.

METHODS

A systematic search of 4 different databases (PubMed, Embase, Scopus, and Web of Science) was conducted from their inception to mid-September of 2019. To keep the pooled analysis current, only studies published within the past 5 years were included. Mortality was analyzed based on presence or absence of VCs. Studies with less then 10 patients, with incomplete mortality data, and not accessible in the English language were excluded.

RESULTS

Ten studies were included in the analysis encompassing 1,643 patients over a 5-year period. There were 369 patients with a cumulative VC rate of 22.5% (range 9.4 to 43.9%). The pooled mortality rate for patients with and without VCs was 69.6% and 56.8%, respectively. Meta-analysis demonstrated a significant correlation between VCs and mortality with a relative risk (RR) of 1.36 (95% confidence interval (CI), 1.15-1.60; P = 0.0004). Covariate-adjusted meta-regression analysis revealed an inverse relationship between age and mortality for VCs, with an RR of 1.33 (95% CI, 1.15-1.54; P = 0.0184), and direct relationship between female gender and mortality from VCs, RR 1.39 (95% CI, 1.21-1.59; P = 0.0165).

CONCLUSIONS

The most recently available data published in the literature demonstrate a significant correlation of VCs with mortality. Therefore, aggressive attempts should be made to minimize VCs in patients with femoral VA-ECMO cannulation.

Vascular Complications Increase Hospital Charges and Mortality in Adult Patients on Extracorporeal Membrane Oxygenation in the United States

Patients on extracorporeal membrane oxygenation (ECMO) who suffer vascular complications frequently accrue additional procedures and costs. We sought to evaluate the effect of ECMO-related vascular complications on hospital charges and in-hospital mortality. Adult discharges involving ECMO from 2004 to 2013 in the National Inpatient Sample were examined. There were 12,636 patients in the cohort. Vascular complications, focusing on arterial complications were identified using ICD-9-CM diagnosis and procedure codes. A multivariable survey linear regression model using median hospital charges was used to model the effect of vascular complications on charges. We used multivariable survey logistic regression to evaluate the effect of vascular complications on in-hospital mortality. Of the 12,636 patients examined, 6467 (51.2%) had ECMO-related vascular complications. Median charges in patients with vascular complications were $ 477,363 (interquartile range: 258,660-875,823) and were $ 282,298 (interquartile range: 130,030-578,027) without vascular complications. On multivariable analysis, patients with vascular complications had 24% higher median charges than patients without vascular complications (Ratio: 1.24; 95% confidence interval [CI]: 1.16-1.33; P < 0.0001) and 34% higher odds of experiencing in-hospital mortality than patients without vascular complications (adjusted odds ratio: 1.34; 95% CI:1.08-1.66; P = 0.009). Vascular complications occur in over half of ECMO patients and are associated with an increased risk of high hospital charges and in-hospital mortality. These findings support the need for identification and modification of risk factors for ECMO-related vascular complications. Furthermore, the standardization of protocols using evidence-based measures to mitigate vascular complications may improve overall ECMO outcomes.

The science of safety: complications associated with the use of mechanical circulatory support in cardiogenic shock and best practices to maximize safety

Acute mechanical circulatory support (MCS) devices are widely used in cardiogenic shock (CS) despite a lack of high-quality clinical evidence to guide their use. Multiple devices exist across a spectrum from modest to complete support, and each is associated with unique risks. In this review, we summarize existing data on complications associated with the three most widely used acute MCS platforms: the intra-aortic balloon pump (IABP), Impella systems, and veno-arterial extracorporeal membrane oxygenation (VA-ECMO). We review evidence from available randomized trials and highlight challenges comparing complication rates from case series and comparative observational studies where a lack of granular data precludes appropriate matching of patients by CS severity. We further offer a series of best practices to help shock practitioners minimize the risk of MCS-associated complications and ensure the best possible outcomes for patients.

Limb ischemia and bleeding in patients requiring venoarterial extracorporeal membrane oxygenation

OBJECTIVE

Acute limb ischemia (ALI) and cannulation site bleeding are frequent complications of venoarterial (VA) extracorporeal membrane oxygenation (ECMO) and are associated with worse outcomes. The goals of this study were to assess our rates of ECMO-related ALI and bleeding and to evaluate the efficacy of strategies to prevent them, such as distal perfusion cannula (DPC) and ultrasound-guided cannulation.

METHODS

This is a single-center retrospective cohort study of adult patients placed on peripheral VA-ECMO at a tertiary medical center between 2014 and 2018. ALI was defined as new ischemia of the extremity ipsilateral to arterial cannulation. Significant cannulation site bleeding was defined as excessive bleeding requiring intervention (eg, transfusion or reoperation). Univariate analyses were used to identify factors associated with ALI, bleeding, and in-hospital mortality.

RESULTS

During the study period, 105 patients were placed on peripheral VA-ECMO (61.3% female; mean age, 54.9 ± 14.8 years). Nearly half (46.6%) had ECMO implantation in an extracorporeal cardiopulmonary resuscitation setting and 37 (44.0%) had a DPC. Average duration of support was 5.6 ± 5.0 days. Overall in-hospital mortality and death on ECMO support were 65.1% and 50%, respectively. ALI occurred in 21 (20%) and cannulation-related bleeding occurred in 24 (22.9%) patients who were treated with a total of 27 procedures, including thromboembolectomy (22.2%), vascular repair (18.5%), and fasciotomy (25.9%). On univariate analysis, cannulation in the operating room (odds ratio [OR], 0.25; 95% confidence interval [CI], 0.08-0.77; P = .02) was associated with decreased risk of ALI, whereas cannulation in the operating room (OR, 2.65; 95% CI, 1.09-6.45; P = .03) and cutdown approach (OR, 4.96; 95% CI, 2.32-10.61; P < .0001) were associated with increased risk of bleeding. Ultrasound-guided placement was associated with decreased risk of bleeding (OR, 0.81; 95% CI, 0.04-0.84; P = .03). DPC was not associated with either ALI (P = .47) or bleeding (P = .06). ALI (OR, 2.68; 95% CI 1.03-6.98; P = .04), age (OR, 1.94; 95% CI, 1.03-3.69; P = .04), and worse baseline heart failure (OR, 2.01; 95% CI, 1.02-3.97; P = .04) were associated with greater risk of in-hospital mortality. Ultrasound-guided cannulation (OR, 0.41; 95% CI, 0.20-0.87; P = .02) was associated with decreased risk of in-hospital mortality.

CONCLUSIONS

ALI and significant bleeding are common occurrences after peripheral VA-ECMO cannulation. Whereas DPC placement did not significantly decrease risk of ALI, ultrasound-guided cannulation decreased the risk of bleeding. Cannulation in the operating room is associated with decreased risk of ALI at the expense of increased risk of bleeding. ALI, older age (≥65 years), and worse heart failure increased risk of in-hospital mortality.

Long-Term Venovenous Connection for Extracorporeal Carbon Dioxide Removal (ECCO2R)-Numerical Investigation of the Connection to the Common Iliac Veins

Purpose

Currently used cannulae for extracorporeal carbon dioxide removal (ECCO₂R) are associated with complications such as thrombosis and distal limb ischemia, especially for long-term use. We hypothesize that the risk of these complications is reducible by attaching hemodynamically optimized grafts to the patient’s vessels. In this study, as a first step towards a long-term stable ECCO₂R connection, we investigated the feasibility of a venovenous connection to the common iliac veins. To ensure its applicability, the drainage of reinfused blood (recirculation) and high wall shear stress (WSS) must be avoided.

Methods

A reference model was selected for computational fluid dynamics, on the basis of the analysis of imaging data. Initially, a sensitivity analysis regarding recirculation was conducted using as variables: blood flow, the distance of drainage and return to the iliocaval junction, as well as the diameter and position of the grafts. Subsequently, the connection was optimized regarding recirculation and the WSS was evaluated. We validated the simulations in a silicone model traversed by dyed fluid.

Results

The simulations were in good agreement with the validation measurements (mean deviation 1.64%). The recirculation ranged from 32.1 to 0%. The maximum WSS did not exceed 5.57 Pa. The position and diameter of the return graft show the highest influence on recirculation. A correlation was ascertained between recirculation and WSS. Overall, an inflow jet directed at a vessel wall entails not only high WSS, but also a flow separation and thereby an increased recirculation. Therefore, return grafts aligned to the vena cava are crucial.

Conclusion

In conclusion, a connection without recirculation could be feasible and therefore provides a promising option for a long-term ECCO₂R connection.

Numerical analysis of aortic hemodynamics under the support of venoarterial extracorporeal membrane oxygenation and intra-aortic balloon pump

BACKGROUND AND OBJECTIVE

A gap still exists in the hemodynamic effect of intra-aortic balloon pump (IABP), venoarterial extracorporeal membrane oxygenation (VA-ECMO), and VA-ECMO plus IABP on the blood perfusion of the coronary artery, brain, and lower limb; the relation between heart flow and ECMO flow; and the wall stress of vessels.

METHODS

A finite-element model of the aorta, ECMO, and IABP was proposed to calculate the mechanical response via fluid-structure interaction. Heart failure (HF), IABP, ECMO, and ECMO plus IABP were utilized to study the effect of support models.

RESULTS

For the pressure curve, VA-ECMO weakened the dicrotic notch of pressure compared with HF and the pulsatile index (0.494 vs. 0.706 vs. 0.471 vs. 0.613). IABP, ECMO, and ECMO plus IABP increased the perfusion of the coronary, brain, and renal artery compared with HF. However, ECMO and ECMO plus IABP clearly reduced the blood flow of the left arteria femoralis compared to that of the right arteria femoralis (ECMO: 194.04 vs. 730.80 mL/min; ECMO plus IABP: 342.15 vs. 947.22 mL/min). In addition, the flow of ECMO accessed the renal artery more than the left ventricular flow. Greater ventricular flow perfused to the renal artery at a diastolic period for ECMO plus IABP, especially at the time points of 2.192 s and 2.304 s. Compared to the velocity distribution with ECMO, the flow of the right arteria femoralis was increased in the process of IABP-on. According to these four cases, the stress of the vascular wall was increased for ECMO support at the systolic period. The peak wall stress of ECMO is increased by 20% at 1.68 s.

CONCLUSIONS

ECMO plus IABP is more conducive to the blood supply than other cases from the result of numerical simulation. The location of blood intersection was generated in the region of the renal artery, which is estimated carefully.

Complications of Temporary Percutaneous Mechanical Circulatory Support for Cardiogenic Shock: An Appraisal of Contemporary Literature

Cardiogenic shock (CS) is associated with hemodynamic compromise and end-organ hypoperfusion due to a primary cardiac etiology. In addition to vasoactive medications, percutaneous mechanical circulatory support (MCS) devices offer the ability to support the hemodynamics and prevent acute organ failure. Despite the wide array of available MCS devices for CS, there are limited data on the complications from these devices. In this review, we seek to summarize the complications of MCS devices in the contemporary era. Using a systems-based approach, this review covers domains of hematological, neurological, vascular, infectious, mechanical, and miscellaneous complications. These data are intended to provide a balanced narrative and aid in risk-benefit decision-making in this acutely ill population.

Medical Optimization and Liberation of Adult Patients From VA-ECMO

Venoarterial extracorporeal membrane oxygenation (VA-ECMO) can be an efficacious cardiopulmonary support for adults as rescue from refractory cardiogenic shock. It is best employed as a bridging strategy to recovery or alternative support rather than sustained, long-term mechanical circulatory support. The purpose of this paper is to discuss strategies to optimize patient management on VA-ECMO and approaches to promote successful separation from support. Rapid medical optimization will assist in reducing the time on VA-ECMO, thereby improving the likelihood of patient salvage. Suitably trained physicians and personnel, guided by structured protocols, can promote excellence in team care and provision of consistent management. Focusing on anticoagulation, careful neurologic monitoring, prevention of leg ischemia, awareness of differential hypoxemia, optimizing mechanical ventilation, identifying and timely intervention for left-ventricular distension (LVD), along with a strategic weaning algorithm, can prevent significant morbidity and mortality. LVD physiology, diagnosis, and risk factors are reviewed. Indications for LV decompression, along with medical and mechanical management options, are elucidated.

Limb ischemia in peripheral veno-arterial extracorporeal membrane oxygenation: a narrative review of incidence, prevention, monitoring, and treatment

Veno-arterial extracorporeal membrane oxygenation (V-A ECMO) is an increasingly adopted life-saving mechanical circulatory support for a number of potentially reversible or treatable cardiac diseases. It is also started as a bridge-to-transplantation/ventricular assist device in the case of unrecoverable cardiac or cardio-respiratory illness. In recent years, principally for non-post-cardiotomy shock, peripheral cannulation using the femoral vessels has been the approach of choice because it does not need the chest opening, can be quickly established, can be applied percutaneously, and is less likely to cause bleeding and infections than central cannulation. Peripheral ECMO, however, is characterized by a higher rate of vascular complications. The mechanisms of such adverse events are often multifactorial, including suboptimal arterial perfusion and hemodynamic instability due to the underlying disease, peripheral vascular disease, and placement of cannulas that nearly occlude the vessel. The effect of femoral artery damage and/or significant reduced limb perfusion can be devastating because limb ischemia can lead to compartment syndrome, requiring fasciotomy and, occasionally, even limb amputation, thereby negatively impacting hospital stay, long-term functional outcomes, and survival. Data on this topic are highly fragmentary, and there are no clear-cut recommendations. Accordingly, the strategies adopted to cope with this complication vary a great deal, ranging from preventive placement of antegrade distal perfusion cannulas to rescue interventions and vascular surgery after the complication has manifested.This review aims to provide a comprehensive overview of limb ischemia during femoral cannulation for VA-ECMO in adults, focusing on incidence, tools for early diagnosis, risk factors, and preventive and treating strategies.