Acute severe pulmonary hypertension during weaning from cardiopulmonary bypass for aortic valve replacement surgery: A case report.

Pulmonary arterial pressure (PAH) usually increases after cardiopulmonary bypass (CPB), but this normally does not affect weaning off CPB. Here we report a case of severe PAH in a patient with normal left atrial pressure. Prolonging CPB by 45 min did not lead to lower PAH. Given that lung injury can stimulate secretion of vasoconstrictors that trigger PAH, we decided to gradually increase blood flow into the lungs in an effort to restore the balance between pulmonary vasoconstrictors and vasodilators. Pulmonary artery pressure gradually decreased, allowing the patient to be weaned off CPB, after which she recovered uneventfully. Our experience suggests an approach for managing acute, severe PAH after CPB without the need for mechanical circulatory support.

Cardiopulmonary bypass for total aortic arch replacement surgery: A review of three techniques.

One treatment for acute type A aortic dissection is to replace the ascending aorta and aortic arch with a graft during circulatory arrest of the lower body, but this is associated with high mortality and morbidity. Maintaining the balance between oxygen supply and demand during circulatory arrest is the key to reducing morbidity and is the primary challenge during body perfusion. The aim of this review is to summarize current knowledge of body perfusion techniques and to predict future development of this field. We present three perfusion techniques based on deep hypothermic circulatory arrest (DHCA): DHCA alone, DHCA with selective cerebral perfusion, and DHCA with total body perfusion. DHCA was first developed to provide a clear surgical field, but it may contribute to stroke in 4%-15% of patients. Antegrade or retrograde cerebral perfusion can provide blood flow for the brain during circulatory arrest, and it is associated with much lower stroke incidence of 3%-9%. Antegrade cerebral perfusion may be better than retrograde perfusion during longer arrest. In theory, blood flow can be provided to all vital organs through total body perfusion, which can be implemented via either arterial or venous systems, or by combining retrograde inferior vena caval perfusion with antegrade cerebral perfusion. However, whether total body perfusion is better than other techniques require further investigation in large, multicenter studies. Current techniques for perfusion during circulatory arrest remain imperfect, and a technique that effectively perfuses the upper and lower body effectively during circulatory arrest is missing. Total body perfusion should be systematically compared against selective cerebral perfusion for improving outcomes after circulatory arrest.

Perfusion of brain and viscera using modified retrograde cerebral perfusion for aortic arch surgery.

Anterograde or retrograde cerebral perfusion can protect the brain from ischemic injury during hypothermic circulatory arrest (HCA), but neither type of perfusion provides blood flow to the abdominal viscera. Here, we report a modified retrograde cerebral perfusion (RCP) technique in which we tethered both superior and inferior venae cavae with bands around the cannula and clamped the distal ends of the drainage tubes of both venae cavae. Modified RCP may provide greater blood flow to the brain and lower body than conventional RCP during HCA in hemiarch surgery.

Comparative effects of different types of cardioplegia in cardiac surgery: A network meta-analysis.

Objective: To compare the outcomes of four types of cardioplegia during cardiac surgery: del Nido (DN), blood cardioplegia (BC), histidine-tryptophan-ketoglutarate (HTK) and St. Thomas. Methods: Randomized controlled trials (RCTs) and observational cohort studies from 2005 to 2021 were identified in PubMed, Embase, and Cochrane databases. Data were extracted for the primary endpoint of perioperative mortality as well as the following secondary endpoints: atrial fibrillation, renal failure, stroke, use of an intra-aortic balloon pump, re-exploration, intensive care unit stay and hospital stay. A network meta-analysis comparing all four types of cardioplegia was performed, as well as direct meta-analysis comparing pairs of cardioplegia types. Results: Data were extracted from 18 RCTs and 49 observational cohort studies involving 18,191 adult patients (55 studies) and 1,634 children (12 studies). Among adult patients, risk of mortality was significantly higher for HTK (1.89, 95% CI 1.10, 3.52) and BC (RR 1.73, 95% CI 1.22, 2.79) than for DN. Risk of atrial fibrillation was significantly higher for BC (RR 1.41, 95% CI 1.09, 1.86) and DN (RR 1.51, 95% CI 1.15, 2.03) than for HTK. Among pediatric patients, no significant differences in endpoints were observed among the four types of cardioplegia. Conclusions: This network meta-analysis suggests that among adult patients undergoing cardiac surgery, DN may be associated with lower perioperative mortality than HTK or BC, while risk of atrial fibrillation may be lower with HTK than with BC or DN.

Retrograde inferior vena caval perfusion for total aortic arch replacement surgery: a randomized pilot study.

OBJECTIVES: Antegrade cerebral perfusion (ACP) under moderate hypothermic circulatory arrest is used during total aortic arch replacement surgery (TARS) in patients with acute type A aortic dissection, but it is associated with high mortality and morbidity. We hypothesized that combining ACP with retrograde inferior vena caval perfusion (RIVP) improves outcomes. METHODS: This pilot study was prospective, randomized, controlled and assessor-blinded. Patients scheduled for TARS were randomly treated with either ACP or RIVP + ACP. The primary outcome was a composite of mortality and major complications including paraplegia, postoperative renal failure, severe liver dysfunction, and gastrointestinal complications. Secondary outcomes included neurological complications, length of intubation and requirement of blood products. RESULTS: A total of 76 patients were recruited (n = 38 per group). Primary outcome occurred in 23 patients (61%) in the ACP group and 16 (42%) in the RIVP + ACP group (OR: 0.60, 95% CI: 0.21-1.62; p = 0.31). There was a lower incidence of transient neurological deficits in the RIVP + ACP group (26% vs. 58%, OR: 0.26; 95% CI: 0.10-0.67,p = 0.006;). The RIVP + ACP group underwent shorter intubation (25 vs 47 h, p = 0.022) and required fewer blood products (red cells, 3.8 units vs 6.5 units, p = 0.047; platelet: 2.0 units vs 2.0 units, p = 0.023) compared with the ACP group. CONCLUSIONS: RIVP + ACP may be associated with lower incidence of transient neurological deficits, shorter intubation and less blood transfusion requirement than ACP alone during TARS. Multi-center, randomized trials with larger samples are required to determine whether RIVP + ACP is associated with lower rates of mortality and major complications. TRIAL REGISTRATION: Pilot study of a RCT registered in clinicaltrials.gov (NCT03607786), Registered 30 July, 2018-Retrospectively registered, https://clinicaltrials.gov/ct2/show/NCT03607786 .

Total body retrograde perfusion during hypothermic circulatory arrest is unsafe.

Retrograde cerebral perfusion and retrograde inferior vena cava perfusion at a pressure of 25 mmHg can protect brain and visceral organs during hypothermic circulatory arrest. Total body retrograde perfusion has been proposed as an alternative during aortic arch surgery. We describe two patients who received total body retrograde perfusion during hemi-arch replacement. The procedure had to be terminated at 8 and 15 minutes due to severe fluid retention and decline in cerebral oxygen saturation. Delirium occurred in one patient after surgery. We concluded that total body retrograde perfusion may be associated with high risk of hypoperfusion and should not be recommended.

Retrograde Inferior Vena caval Perfusion for Total Aortic arch Replacement Surgery (RIVP-TARS): study protocol for a multicenter, randomized controlled trial.

BACKGROUND: During total aortic arch replacement surgery (TARS) for patients with acute type A aortic dissection, the organs in the lower body, such as the viscera and spinal cord, are at risk of ischemia even when antegrade cerebral perfusion (ACP) is performed. Combining ACP with retrograde inferior vena caval perfusion (RIVP) during TARS may improve outcomes by providing the lower body with oxygenated blood. METHODS: This study is designed as a multicenter, computer-generated, randomized controlled, assessor-blind, parallel-group study with a superiority framework in patients scheduled for TARS. A total of 636 patients will be randomized on a 1:1 basis to a moderate hypothermia circulatory arrest (MHCA) group, which will receive selective ACP with moderate hypothermia during TARS; or to an RIVP group, which will receive the combination of RIVP and selective ACP under moderate hypothermia during TARS. The primary outcome will be a composite of early mortality and major complications, including paraplegia, postoperative renal failure, severe liver dysfunction, and gastrointestinal complications. All patients will be analyzed according to the intention-to-treat protocol. DISCUSSION: This study aims to assess whether RIVP combined with ACP leads to superior outcomes than ACP alone for patients undergoing TARS under moderate hypothermia. This study seeks to provide high-quality evidence for RIVP to be used in patients with acute type A aortic dissection undergoing TARS. TRIAL REGISTRATION: Clinicaltrials.gov, ID: NCT03607786 . Registered on 30 July 2018.

Combining Cerebral Perfusion With Retrograde Inferior Vena Caval Perfusion for Aortic Arch Surgery.

Hypothermic circulatory arrest and selective cerebral perfusion are standard procedures during total arch replacement to treat acute type A aortic dissection. However, organ ischemia during anastomosis between the graft and descending aorta contribute to high risk of mortality and morbidity. Here we describe the combination of antegrade cerebral perfusion and retrograde inferior vena caval perfusion as a way to ensure continual perfusion of the brain, abdominal viscera, and spinal cord during anastomosis and thereby improve outcomes of total arch replacement.

Assessment of three methods for removing massive air in a cardiopulmonary bypass circuit: simulation-based multi-discipline training in West China Hospital.

BACKGROUND AND OBJECTIVE: A multi-discipline cardiac and cardiopulmonary bypass (CPB) team simulation scenario was established to compare three different de-airing approaches dealing with massive air embolism in CPB, so as to formulate a standardized procedure to handle this adverse acute event more proficiently and ensure clinical safety. METHOD: A simulation-based clinical CPB massive air embolism scenario was developed by a cardiac and CPB team. Study Objects: Five licensed perfusionists and five CPB trainees were matched randomly into five pairs. Each pair would simulate the three different de-airing approaches separately as followed: (1) Conventional Method: arterial line filter (ALF) de-airing purge line and oxygenator self-recirculation bypass were used to de-air; (2) Arterial-Venous Loop (A-V Loop) Method: surgeons reconnected the arterial and venous lines to de-air by restoring the original priming A-V loop configuration; (3) Isolation of the ALF Method: this ensures de-bubbling of the CPB circuit, but bypasses the ALF function. Assessment Criteria: (1) Times to recovery (duration of the circulation suspension); (2) Subjective evaluation of skill and non-skill performances. RESULTS: As to times to recovery, the Conventional Method group took 290.6 s ± 36.2, the A-V Loop Method group took 196.8 s ± 52.0 and the Isolation of ALF group took 99.4 s ± 15.1. The statistical difference is significant among the three groups (p<0.01). The subjective evaluation of training performance indicates that this simulation-based training is effective in assessing both skill and non-skill abilities. CONCLUSION: CPB simulation-based training was effective in comparing de-airing strategies and can instruct perfusion practices how to optimize techniques. For well-trained, multi-discipline cardiac teams, the A-V Loop Method is highly efficient and reliable in managing CPB massive air embolism. For cardiac teams that do not have this sophisticated training, the Isolation of ALF Method should be their alternative option.

Effect of intralipid on myocardial injury during valve replacement surgery with concomitant radiofrequency ablation: A randomized controlled trial.

BACKGROUND: This study aimed to evaluate the effect of intralipid postconditioning (ILPC) on myocardial damage in patients undergoing valve replacement surgery with concomitant radiofrequency ablation (RFA) for atrial fibrillation (AF). METHODS: Randomized patient and assessor-blind controlled trial conducted in adult patients undergoing valve replacement surgery with concomitant RFA. Sixty-nine patients were randomly assigned to ILPC group (n = 34) or control group (n = 35): ILPC group received an intravenous infusion of 20% intralipid (2 mL/kg) just 10 minutes before aortic cross-unclamping, and control group received an equivalent volume of normal saline. Serum cardiac troponin-T (cTnT) and creatine kinase-MB (CK-MB) was measured before surgery and at 4, 12, 24, 48, and 72 hours after surgery. The primary endpoints were the 72-hour area under the curve (AUC) for cTnT and CK-MB. RESULTS: The total 72-hour AUC of cTnT (P = .33) and CK-MB (P = .52) were comparable between 2 groups. The left ventricle ejection fraction at discharge (P = .011) was higher in the ILPC group than that in the control group, while the AF recurrence did not differ significantly between 2 groups. CONCLUSIONS: There was no observed beneficial effect of ILPC on myocardial injury documented by the cardiac biomarkers in patients undergoing valve replacement surgery with concomitant RFA, and the effect of intralipid against myocardial I/R injury is undetectable within the background of massive biomarker release following ablation owing to localized myocardial necrosis. Besides, there are no other published data about the cardioprotective role of intralipid in patients undergoing this procedure and benefits of this protection need further studies to validate.

Effect of intralipid postconditioning on myocardial injury in patients undergoing valve replacement surgery: a randomised controlled trial.

OBJECTIVE: This study was conducted to determine whether the administration of intralipid just before aortic cross-unclamping would reduce myocardial injury in patients undergoing valve replacement surgery. METHODS: Seventy-three adult patients, scheduled for elective aortic or mitral valve surgery without significant coronary stenosis (>70%), were randomly assigned to the intralipid postconditioning (ILPC) group (n=37) or control group (n=36): the ILPC group received an intravenous infusion of 20% intralipid (2 mL/kg) just 10 min before aortic cross-unclamping, and the control group received an equivalent volume of normal saline. Serum cardiac troponin T (cTnT) and creatine kinase-MB (CK-MB) was measured before surgery and at 4, 12, 24, 48 and 72 hours after surgery. The primary end points were the 72-hour area under the curve (AUC) for cTnT and CK-MB. RESULTS: No significant difference between the ILPC and control arm was observed, including the age, sex or number of aortic versus mitral valves or left ventricular ejection fraction at baseline. The total 72-hour AUC of cTnT and CK-MB in patients assigned to ILPC were significantly reduced by 32.3% (p=0.004) and 26.4% (p=0.0185) compared with control, respectively. None of the treated patients had abnormal blood lipid metabolism, abnormal renal or hepatic function or significant related complications. CONCLUSION: The protective effect of postischaemic administration of intralipid prior to aortic cross-unclamping on reperfusion injury was found when determined by biomarkers of myocardial injury but not by cardiac function or other clinical outcomes in patients undergoing valve replacement surgery. Hence, clinical benefits of this protection need larger clinical trials to confirm. TRIAL REGISTRATION NUMBER: ClinicalTrials.gov ID: ChiCTR-IOR-14005318.

Low-Dose Sevoflurane May Reduce Blood Loss and Need for Blood Products After Cardiac Surgery: A Prospective, Randomized Pilot Study.

Patients undergoing cardiac surgery often experience abnormal bleeding, due primarily to cardiopulmonary bypass (CPB)-induced activation of platelets. Sevoflurane may inhibit platelet activation, raising the possibility that administering it during CPB may reduce blood loss.Patients between 18 and 65 years old who were scheduled for cardiac surgery under CPB at our hospital were prospectively enrolled and randomized to receive intravenous anesthetics alone (control group, n = 77) or together with sevoflurane (0.5-1.0 vol/%) from an oxygenator (sevoflurane group, n = 76). The primary outcome was postoperative blood loss, the secondary outcome was postoperative need for blood products.Volume of blood loss was 48% lower in the sevoflurane group than the control group at 4 hours after surgery, and 33% lower at 12 hours after surgery. Significantly fewer patients in the sevoflurane group lost >700 mL blood within 24 hours (9 of 76 vs 28 of 77, P < 0.001). As a result, the sevoflurane group received significantly smaller volumes of packed red blood cells (1.25 ±â€Š2.36 vs 2.23 ±â€Š3.75 units, P = 0.011) and fresh frozen plasma (97 ±â€Š237 vs 236 ±â€Š344 mL, P = 0.004). Thus the sevoflurane group was at significantly lower risk of requiring complex blood products after surgery (adjusted odds ratio [OR] 0.34, 95% confidence interval [CI] 0.17-0.68, P = 0.002).Sevoflurane inhalation from an oxygenator during CPB may reduce blood loss and need for blood products after cardiac surgery.