Pediatric Femoral Arterial Cannulations in Extracorporeal Membrane Oxygenation: A Review and Strategies for Optimization

Applications for ultrasound in pediatric surgery

Ultrasound (US) use within pediatric surgery is expanding rapidly. While US guidance for central line placement has been common practice for many years now, advances in the quality of images, portability of US machines, and a lack of radiation associated with imaging has led to broader application in many other aspects of surgery, ranging from diagnostics to performing operations under the direction of point-of-care ultrasound (POCUS). The relatively short learning curve for providers along with excellent image quality in children due to their small size provides an easy, effective imaging modality with diverse applications. Discussed here is a broad overview of the spectrum of US use within current pediatric surgical practices.

Lower extremity complications in children following femoral cannulation for extracorporeal membrane oxygenation

INTRODUCTION

Extracorporeal membrane oxygenation cannulation strategies vary between adults and children. Femoral approach is common in adults and extremity morbidity is well-documented. Aside from limb ischemia, complications in children are theorized and have yet to be studied. This study aims to comprehensively evaluate implications of pediatric femoral cannulation.

METHODS

This is a single-center retrospective review of children <21 years, undergoing femoral venoarterial (VA) or venovenous (VV) cannulation between 2015 and 2022. The primary outcome was incidence of lower extremity complications on ECMO (groin hematoma/hemorrhage, vascular thrombosis, North-South syndrome, compartment syndrome, limb loss). Secondary outcome was incidence of post-decannulation extremity complications (pseudoaneurysm, surgical site infection, vascular thrombosis, motor/sensory deficits).

RESULTS

29 children were cannulated via femoral approach. Most required VA support (89%). Common sites were right femoral artery (70.8%) and right femoral vein (56%). 18 patients (75%) had distal reperfusion cannulas (DPC) placed. Short-term lower extremity complication rate was 59%, most frequently groin hematoma/hemorrhage (30%) and North-South syndrome (19%). Compartment syndrome occurred in 3 patients (11%), though none suffered digit/limb loss. There were no significant differences in complications between cannulation approach (open vs percutaneous) or vessel laterality (ipsilateral vs contralateral). Of those decannulated (n = 15), median ECMO duration was 8 days. Following decannulation, 20% suffered pseudoaneurysm. Ten (63%) experienced ipsilateral motor weakness which resolved in 50% of patients at 1-month follow-up; 20% suffered sensory deficits all resolving by discharge.

CONCLUSION

Approximately one third of children who underwent femoral cannulation suffered groin hematoma/hemorrhage and nearly 20% experienced North-South syndrome. Following decannulation, most had extremity weakness while sensory deficits were rarer. This marked risk of extremity morbidity prompts proactive inpatient monitoring and close surveillance after discharge.

Extracorporeal membrane oxygenation in children: A brief review

With the advancement in technology and increasing familiarity, the use of extracorporeal membrane oxygenation (ECMO) has expanded in the past decade. Although ECMO can be lifesaving for critically ill children, it is an invasive therapy associated with complications that may necessitate rehabilitation and long-term follow-up. Paediatric clinicians play an essential role in managing these children, especially after the acute phase of their illness. This review provides an overview of ECMO and will provide a basic understanding of ECMO and its principles.

Neurological Outcome According to the Site of Cannulation in Septic Children Supported by Venoarterial Extracorporeal Membrane Oxygenation

The impact of cervical cannulation on neurologic outcome has not been yet studied among children receiving venoarterial extracorporeal membrane oxygenation (VA-ECMO) in the context of severe sepsis or septic shock. A retrospective cohort study was performed using the extracorporeal life support organization (ELSO) registry. A total of 559 children weighing less than 20 kg with a primary or secondary diagnosis of severe sepsis, septic shock or toxic shock syndrome were included between January 1, 2010, and December 31, 2019. Cervical cannulation was performed in 485 children (87%) and central cannulation in 74 children (13%). The prevalence of acute neurologic event (ANE) was 32%, including clinical and/or electroencephalographic seizures, cerebral infarction, cerebral hemorrhage, and/or brain death. In multivariable analysis, we did not find an association between cervical cannulation and greater/lesser odds of ANE during ECMO (adjusted odds ratio [aOR] = 1.39, 95% confidence interval [CI] 0.72-2.65; P = 0.326). Only pre-ECMO acidosis was independently associated with the development of ANE (pH < 6.99; aOR = 2.71, 95% CI 1.34-5.49; P = 0.006; pH 6.99 to <7.12; aOR = 2.57, 95% CI 1.37-4.82; P = 0.003). Thus, the site of cannulation appears not as a modifiable neurologic risk factor in this young septic population.

Pediatric arterial femoral cannulations for extracorporeal membrane oxygenation: Does size really matter?

BACKGROUND

No studies exist comparing various femoral artery cannula sizes in children on ECMO. We hypothesize that smaller arterial cannulas provide adequate flow in children while decreasing vascular complications.

METHODS

We performed a retrospective review of the ELSO database from 2012-2017. We included children undergoing femoral venoarterial ECMO between ages 12 and 18 years and weighing more than 30 kg. Arterial cannula sizes were grouped as: 15-16Fr, 17-18Fr, 19-20Fr and ≥21Fr. Arterial pump flow, bleeding complications, limb ischemia, and mechanical complications were compared by cannula size. Distal perfusion catheter and percutaneous placement were also compared for complications.

RESULTS

A total of 429 patients were included with 28.2% 15-16Fr, 32.2% 17-18Fr, 22.8% 19-20Fr, and 16.8% ≥ 21Fr arterial femoral cannulas. Median age was lower in the 15-16Fr group compared to the largest cannula group (14.7 years vs 15.5 years, p < 0.01). The overall mean arterial flow was 57.4 +/- 17.0 mL/kg/min with no difference in mean arterial flow rates among the cannula size groups (p = 0.85). There were no significant differences in all complications, bleeding or mechanical complications by arterial cannula size group. However, there was an increased risk of limb ischemia in the ≥21Fr group compared to the 15-16Fr group (OR 4.38, 95% CI 1.24-15.43; p = 0.02). Distal perfusion catheter was shown to increase the risk of mechanical complications (OR 1.78; 95% CI 1.03-3.07; p = 0.04) but did not make a statistically significant difference in limb ischemia (OR 0.37; 95% CI 0.12-1.11; p = 0.07).

CONCLUSION

Review of the ELSO database demonstrates that the use of larger arterial cannulas compared to 15-16Fr cannulas are not needed to achieve similar pump flows for hemodynamic support but the largest cannula sizes may increase the risk of ischemic complications.

Transient upper limb ischaemia during veno-arterial extracorporeal membrane oxygenation in a child

Neck cannulation is the most common cannulation strategy performed to provide veno-arterial extracorporeal membrane oxygenation support in paediatric patients, especially in small children. Upper limb ischaemia is a rare complication of neck cannulation and is likely caused by arterial cannula malposition. We describe a case of right arm ischaemia caused by extrinsic compression of the right subclavian artery by the venous drainage cannula inserted through the right internal jugular vein. Upper limb hypoperfusion was resolved immediately after changing the venous drainage cannula from the right jugular vein to the right femoral vein.

Extracorporeal Life Support Organization (ELSO): Guidelines for Pediatric Cardiac Failure

These guidelines are applicable to neonates and children with cardiac failure as indication for extracorporeal life support. These guidelines address patient selection, management during extracorporeal membrane oxygenation, and pathways for weaning support or bridging to other therapies. Equally important issues, such as personnel, training, credentialing, resources, follow-up, reporting, and quality assurance, are addressed in other Extracorporeal Life Support Organization documents or are center-specific.

Hirudotherapy for neonatal limb ischemia during ECMO support: A word of caution

INTRODUCTION

Disordered coagulation, clot formation and distal limb ischemia are complications of extracorporeal membrane oxygenation (ECMO) with significant morbidity and mortality. Medicinal leech therapy (hirudotherapy) has been attempted in plastic and orthopedic surgeries to improve venous congestion and salvage ischemic flaps. To our knowledge this has not been reported in pediatric cardiac surgery or during ECMO support. We present a complex neonate whose ECMO course was complicated by distal limb ischemia for whom leech therapy was attempted.

PATIENT AND INTERVENTION

A 2-week-old 2.7 kg infant required ECMO support secondary to perioperative multiorgan system dysfunction following repair of critical coarctation and ventricular septal defect. Despite systemic anticoagulation, his clinical course was complicated by arterial thrombus, vasopressor-induced vascular spasm and bilateral distal limb ischemia. Medicinal leech therapy was tried after initially failing conventional measures.

RESULT

Following the third leech application, this patient developed significant hemorrhage from the web space adjacent to the left great toe. An estimated 450 ml of blood loss occurred and more than 300 ml of blood product transfusions were required. He ultimately progressed to irreversible systemic end organ dysfunction and comfort care was provided.

CONCLUSION

The use of medicinal leech therapy in pediatric cardiac surgery may be considered to minimize the consequences of advanced limb ischemia and venous congestion. However, this should be used with caution while patients are systemically anticoagulated during ECMO support. A directed review is presented here to assist in determining optimal application and potential course of therapy.

Pediatric and neonatal extracorporeal life support: current state and continuing evolution

The use of extracorporeal life support (ECLS) for the pediatric and neonatal population continues to grow. At the same time, there have been dramatic improvements in the technology and safety of ECLS that have broadened the scope of its application. This article will review the evolving landscape of ECLS, including its expanding indications and shrinking contraindications. It will also describe traditional and hybrid cannulation strategies as well as changes in circuit components such as servo regulation, non-thrombogenic surfaces, and paracorporeal lung-assist devices. Finally, it will outline the modern approach to managing a patient on ECLS, including anticoagulation, sedation, rehabilitation, nutrition, and staffing.

COVID–19急性呼吸不全への人工呼吸管理とECMO管理：基本的考え方(Mechanical ventilation and extracorporeal membrane oxygenation for acute respiratory failure owing to COVID–19: basic concept)

The pillars of managing critically ill patients with acute respiratory failure owing to coronavirus disease 2019 (COVID–19) are mechanical ventilation and extracorporeal membrane lung oxygenation (ECMO) as supportive therapies for impaired respiratory function. Given the increasing number of patients with COVID–19, a summary of standardized care regarding ECMO that can serve as a reference in clinical practice is proposed as an expert consensus statement. Indications, management practices, and caveats for ECMO management are described, including those in the presence of resource constraints.

Practice patterns in imaging guidance for ECMO cannulation: A survey of the American Pediatric Surgical Association

BACKGROUND

Surgeon-specific variations in pediatric extracorporeal membrane oxygenation (ECMO) cannulation technique are not well characterized. Advances in technology have led to changing techniques with no formal consensus statement for reference.

METHODS

A survey was e-mailed to 1301 members of the American Pediatric Surgical Association (APSA). Categorical data was compared with Chi-squared and Kendall's tau-β tests, and multiple column comparisons were performed with the Bonferroni correction.

RESULTS

Response rate was 19%, with 248 pediatric general surgeons responding to the survey. 89.4% of respondents stated that cannulation was typically performed in the ICU. Venoarterial (VA) ECMO cannulation was more often performed open (88.6%) than venovenous (VV) ECMO (42.2%). Surgeons cannulate for VA ECMO and VV ECMO without imaging guidance 44% and 21.5% of the time, respectively. There was no difference in estimated rate of cannula repositioning by cannulation strategy. For venous and arterial cannulation in VA ECMO, surgeons were more likely to use the femoral as opposed to the neck when children were older than 13 years and weighed more than 35 kg regardless of the presence or absence of preexisting femoral arterial or venous access.

CONCLUSION

Practice patterns for ECMO cannulation are variable among pediatric surgeons. Standardization could reduce the occurrence of unsafe practices and potentially decrease complications and improve patient outcomes.

LEVEL OF EVIDENCE

Level IV.

Dual-layer everted saphenous vein patch for pediatric femoral artery repair following ECMO decannulation

Decannulation from pediatric veno-arterial extracorporeal membrane oxygenation (VA-ECMO) involves the removal of large arterial perfusion cannulas from relatively small lower extremity arteries. While these challenging repairs are frequently performed by general pediatric surgeons, there is little standardization with regard to vascular techniques within the pediatric surgery training paradigm, resulting in variability in the repair of these arteriotomies and potential future consequences for lower extremity perfusion and growth. Herein we present a technique for repair of large common femoral arteriotomies following removal of ECMO perfusion cannulas utilizing a dual-layer patch of ipsilateral saphenous vein harvested via the arterial cutdown incision. This vein segment is everted to maximize endothelial surface area of the patch and dual layered to provide additional support against aneurysmal degeneration. The described technique is an effective repair of arteriotomy following VA-ECMO decannulation, which minimizes vascular complications and is an accessible technique to those without advanced vascular surgical training. LEVEL OF EVIDENCE: Level IV; operative technique description with small case series.

Structured review of post-cardiotomy extracorporeal membrane oxygenation: Part 2-pediatric patients

Veno-arterial extracorporeal membrane oxygenation (ECMO) is established therapy for short-term circulatory support for children with life-treating cardiorespiratory dysfunction. In children with congenital heart disease (CHD), ECMO is commonly used to support patients with post-cardiotomy shock or complications including intractable arrhythmias, cardiac arrest, and acute respiratory failure. Cannulation configurations include central, when the right atrium and aorta are utilized in patients with recent sternotomy, or peripheral, when cannulation of the neck or femoral vessels are used in non-operative patients. ECMO can be used to support any form of cardiac disease, including univentricular palliated circulation. Although veno-arterial ECMO is commonly used to support children with CHD, veno-venous ECMO has been used in selected patients with hypoxemia or ventilatory failure in the presence of good cardiac function. ECMO use and outcomes in the CHD population are mainly informed by single-center studies and reports from collated registry data. Significant knowledge gaps remain, including optimal patient selection, timing of ECMO deployment, duration of support, anti-coagulation, complications, and the impact of these factors on short- and long-term outcomes. This report, therefore, aims to present a comprehensive overview of the available literature informing patient selection, ECMO management, and in-hospital and early post-discharge outcomes in pediatric patients treated with ECMO for post-cardiotomy cardiorespiratory failure.