Routine External Iliac Artery Cannulation in Robotic Cardiac Surgery: Role of the Corona "Vitae" in Distal Limb Perfusion

OBJECTIVE

Femoral artery cannulation is the most commonly used approach for cardiopulmonary bypass (CPB) in robotic cardiac procedures. However, without adding a distal perfusion cannula, leg ischemia can occur in up to 11.5% of patients. There is a well-described 2 to 4 mm size arterial branch that originates from the medial side of the external iliac artery or inferior epigastric artery, immediately above the inguinal ligament, and connects to the obturator artery. Therefore, it was historically named the corona mortis, which means "crown of death" in Latin. When peripheral cannulation is performed above this branch in the external iliac artery, we consider it a corona "vitae" because of its role as a limb-saving collateral. We report herein our standard technique of peripheral cannulation without the need of a distal perfusion cannula and preventing limb ischemia.

METHODS

We included all patients who underwent robotic cardiac surgery with peripheral cannulation over a 16-month period at our institution. We cannulated just above the level of the inguinal ligament through a 2 to 3 cm transverse skin incision. The incidence of limb ischemia and vascular complications was recorded and analyzed.

RESULTS

During the study period, 133 patients underwent robotic cardiac procedures with peripheral "external iliac" CPB. The size of the cannula was 21F or larger in 73% and 23F in 54% of the patients. No leg ischemia or femoral artery complications requiring additional intervention occurred.

CONCLUSIONS

External iliac cannulation can be successfully performed in robot-assisted cardiac surgery using relatively large cannulas without the need of a distal limb perfusion catheter, with good results. In our view, given the importance of the corona mortis ("crown of death" in Latin) in perfusing the limb during CPB, we propose a new name for this artery in robotic cardiac surgery, namely, the corona vitae ("crown of life" in Latin).

Moderate Hypothermic Circulatory Arrest Is Preferable During Cardiopulmonary Bypass

The effect of temperature on cerebral injury during hypothermic circulatory arrest (HCA) has never been specifically studied. This study aimed to compare the effects of two different temperatures used for HCA on the degree of brain injury in pig models. Thirteen pigs were randomly assigned to a deep hypothermic circulatory arrest (DHCA) group (n = 5), moderate hypothermic circulatory arrest (MHCA) group (n = 5), or control group (n = 3). No significant differences in immunohistochemical assay results, including Bax, Bcl-2, and Caspase 3 staining, and a TUNEL assay, were observed between the DHCA and MHCA groups. Furthermore, no significant difference was found for biomarkers of brain injury (Soluble protein-100B) between the two experimental groups. Similarly, no significant difference was observed in the trend of changes in inflammatory factors, including tumor necrosis factor-α, interleukin (IL)-2, and IL-6, between the two groups (p > 0.05). However, coagulation factors, including FXI and FVII, were different between the DHCA and MHCA groups (p < 0.05). Therefore, it can be concluded that MHCA does not increase the risk of cerebral injury. Considering the adverse effects of DHCA on the coagulation system, MHCA is more suitable for current clinical practice.

Cardiac Arrest with Multi-vessel Coronary Artery Disease and Successful Treatment After Long Conventional Cardiopulmonary Resuscitation: How Long Is Too Long?

Coronary artery disease (CAD) is the most common killer disease, responsible for about one-third of all deaths at ages above 35. The majority of all survivors of out-of-hospital cardiac arrests present to the emergency department (ED) with an initial shockable rhythm (ventricular fibrillation or pulse-less ventricular tachycardia), which is a predictor of survival. Odds for survival are less for non-shockable rhythm and favorable neurologic outcomes decrease as the length of cardiopulmonary resuscitation (CPR) increases. The median time-to-return of spontaneous circulation among those with favorable neurological outcomes is less than 10 minutes. On the other hand, a large review of more than 64,000 patients with in-hospital cardiac arrests showed that patients with longer median resuscitation times had a greater chance of the return of spontaneous circulation and survival to discharge. We described a case of prolonged resuscitation lasting almost three hours of CPR followed by successful percutaneous intervention with a favorable neurologic outcome.

Combination of biomarkers for diagnosis of acute kidney injury after cardiopulmonary bypass

Novel acute kidney injury (AKI) biomarkers offer promise of earlier diagnosis and risk stratification, but have yet to find widespread clinical application. We measured urinary α and π glutathione S-transferases (α-GST and π-GST), urinary l-type fatty acid-binding protein (l-FABP), urinary neutrophil gelatinase-associated lipocalin (NGAL), urinary hepcidin and serum cystatin c (CysC) before surgery, post-operatively and at 24 h after surgery in 93 high risk patient undergoing cardiopulmonary bypass (CPB) and assessed the ability of these biomarkers alone and in combination to predict RIFLE-R defined AKI in the first 5 post-operative days. Twenty-five patients developed AKI. π-GST (ROCAUC = 0.75), lower urine Hepcidin:Creatine ratio at 24 h (0.77), greater urine NGAL:Cr ratio post-op (0.73) and greater serum CysC at 24 h (0.72) best predicted AKI. Linear combinations with significant improvement in AUC were: Hepcidin:Cr 24 h + post-operative π-GST (AUC = 0.86, p = 0.01), Hepcidin:Cr 24 h + NGAL:Cr post-op (0.84, p = 0.03) and CysC 24 h + post-operative π-GST (0.83, p = 0.03), notably these significant biomarkers combinations all involved a tubular injury and a glomerular filtration biomarker. Despite statistical significance in receiver-operator characteristic (ROC) analysis, when assessed by ability to define patients to two groups at high and low risk of AKI, combinations failed to significantly improve classification of risk compared to the best single biomarkers. In an alternative approach using Classification and Regression Tree (CART) analysis a model involving NGAL:Cr measurement post-op followed by Hepcidin:Cr at 24 h was developed which identified high, intermediate and low risk groups for AKI. Regression tree analysis has the potential produce models with greater clinical utility than single combined scores.

Pulmonary embolus after coronary artery bypass surgery: a review of the literature

Pulmonary embolus (PE) after cardiac bypass surgery is an uncommon complication but carries with it high morbidity and mortality. The incidence of deep vein thrombosis (DVT) and PE after cardiac bypass varies depending on postoperative thromboprophylaxis, the presence of indwelling central venous catheters in the lower extremities, and early ambulation. The clinical diagnosis of DVT remains difficult and challenging. Pulmonary embolus is often the first occurring clinical event. The safety and effectiveness of preventative pharmacologic agents, such as subcutaneous unfractionated or fractionated heparin or oral coumadin, remain largely unknown. Heparin-induced thrombocytopenia, generally associated with a high incidence of DVT and PE, occurs in approximately 3.8% of patients who have undergone cardiac surgery and are placed postoperatively on high-dose intravenous unfractionated heparin. Sequential compression devices (SCD) have not been effective in reducing the incidence of DVT in an ambulating cardiac bypass patient when added to routine elastic graded compression stockings (GCS). Very large clinical trials are necessary to prove the effectiveness of pharmacologic or mechanical preventative measures in reducing the incidence of PE after cardiac surgery above the commonly used GCS, early ambulation, and aspirin. In a nonambulating, higher-risk cardiac bypass patient with slow recovery, a more aggressive prophylaxis regimen might be necessary for optimal prevention, although further data are needed to support this hypothesis.