Optimal timing of SARS-CoV-2 vaccination prior to cardiovascular surgery under cardiopulmonary bypass.

BACKGROUND: mRNA vaccines against severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) became common. We investigated the optimal timing for inoculation against SARS-COV-2 in the candidates for cardiac surgery under cardiopulmonary bypass (CPB). METHODS: In 100 patients with preoperative vaccination, who underwent CPB surgery between July 2021 and February 2022, the IgG against the receptor binding domain (RBD-IgG), with a threshold of >100 binding antibody unit (BAU)/mL for adequate immunity, was measured. RESULTS: The vaccines, including 87 BNT162b2 (Pfizer/BioNTech) and 13 mRNA-1273 (Moderna), were inoculated at 98.8 ± 59.4 days before surgery. The median RBD-IgG titers before surgery, 1 day after surgery, and 1 month after surgery were 166.8, 100.0, and 84.0 BAU/mL, respectively. The standby interval (SBI) from the vaccination to the surgery showed a significantly negative correlations with the RBD-IgG titer before the surgery (p < 0.001). A cut-off SBI for RBD-IgG >100 BAU/mL before surgery was <81 days with a sensitivity of 76%, specificity of 62%, and area under ROC value of 0.73 (p = 0.03). The patients with SBI <81 days (n = 48) had significantly higher RBD-IgG (>100 BAU/mL) than those with SBI ⩾81 days (n = 52) at all perioperative periods. CONCLUSIONS: Although 40% of the RBD-IgG titers reduce 1 day after CPB surgery, the patients who received the SARS-COV-2 vaccination within an 81-day window prior to the surgery maintained a desirable RBD-IgG level, even up to 1 month after surgery. It may be important to schedule the surgery no later than 81 days after the vaccination.

Surgical repair of mitral valve regurgitation with anomalous unilateral single pulmonary vein.

We report a case of surgically repaired symptomatic mitral valve regurgitation (MR) in a 61-year-old woman with anomalous unilateral single pulmonary vein. A two-staged surgery was scheduled; first a catheter embolization of anomalous vessel to avoid recirculation of the blood into the left atrium during cardiopulmonary bypass, and second a mitral valve repair via right lateral thoracotomy. Learning objective: Scimitar sign is a horn-like shape on plain chest radiograph. One of the possible diagnoses is partial anomalous pulmonary venous return (APVR), which often requires surgical interventions due to comorbidities of congenital heart disease and recurrent pneumonia [1-3]. Another is anomalous unilateral single pulmonary vein (AUSPV), which is generally asymptomatic, and therefore, requires no medical interventions. This case addresses the advantage of multidetector computed tomography (CT) and the safety of two-staged strategy.

Effects of cardiopulmonary bypass on immunoglobulin G antibody titres after SARS-CoV2 vaccination.

OBJECTIVES: Patients with cardiovascular disease are vulnerable to severe acute respiratory syndrome coronavirus 2 (SARS-CoV2) infection. Although SARS-CoV2 vaccination may be effective, its impact on surgical patients is not well studied. We investigated the effects of cardiovascular surgery, especially under cardiopulmonary bypass (CPB), on the antibody titres after SARS-CoV2 vaccination. METHODS: A prospective observational study was designed for patients undergoing surgery between July and November 2021. The immunoglobulin G against the receptor-binding domain was measured and antibody preserved rate (APR) was calculated from perioperative titres comparison. RESULTS: Enrolled 63 study patients were divided into 39 undergoing surgery with CPB (Group CPB) and 24 without CPB (Group None). Preoperative vaccines were BNT162b2 (Pfizer/BioNTech) (n = 58, 92%) and mRNA-1273 (Moderna) (n = 5, 8%). While immunoglobulin G against the receptor-binding domain titres did not significantly decrease after surgery in Group None, they decreased significantly in Group CPB from 21.80 [11.15, 37.85] to 11.95 [6.80, 18.18] U/ml (P < 0.001) a day after surgery, 11.40 [7.85, 22.65] U/ml (P < 0.001) 14 days after surgery and 7.60 [4.80, 17.60] U/ml (P < 0.001) a month after surgery. The APRs a day after the surgery were significantly lower in Group CPB (0.46 [0.41, 0.60]) than in Group None (0.80 [0.68, 0.87]) (P < 0.001). CONCLUSIONS: The SARS-CoV2 antibody titres significantly decreased with lower APRs immediately after surgery under CPB. Based on our informative results, careful considerations of vaccination schedule might be required for surgery under CPB.

Two-staged surgical treatment for Kommerell diverticulum with a right aortic arch and an aberrant left subclavian artery.

Kommerell diverticulum (KD) is an aneurysm of the orifice of an aberrant subclavian artery (SCA) from the descending aorta or aortic arch. We have performed two-staged surgical strategy for the treatment of KD with right aortic arch. The first step was the bypass grafting between the left common carotid artery and the aberrant left SCA with occlusion of the distal side of KD with the plug. The second step was the descending aorta replacement through the right thoracotomy. Four patients underwent these operations. No hospital deaths or major complications were observed. All four patients were discharged and have been alive for 1-6 years without any health problems. Two of four patients had symptoms of dysphagia preoperatively, and it resolved postoperatively in both patients. No hoarseness occurred after surgery, and 1-6 years of CT observation showed no recanalization of the vascular plug.

[Mitral Valve Surgery for a Patient with Mediastinal Shift after Left Pneumonectomy:Report of a Case].

A 70-year-old patient who survived about 40 years after left pneumonectomy for tuberculosis visited emergency hospital, because of dyspnea. She received suitable medical therapy for atirial fibrillation and severe mitral regurgitation and hesitated heart surgery because of anxiety for surgical risk. The computed-tomography showed mediastinal shift to left and right lung compensatory expansion. Respiratory function test after treatment of heart failure showed only mild restrictive disorder. And the blood-gas examination in room air was 101 mmHg of Pao2 and 37 mmHg of Paco2. The mitral valve replacement was performed via median sternotomy and using normal cardiopulmonary bypass. And she fully recoverd without any respiratory complications. Mediastinal shift did not obstract the surgical view and establishment of cardiopulmonary bypass in this case. It seemed that the key of surgical successs is the preserved function of healthy residual lung.

Relationship between fractional flow reserve and graft patency after coronary artery bypass grafting.

BACKGROUND: Bypass for moderately stenosed coronary arteries may cause graft failure (string phenomenon or occlusion). We examined the effects of fractional flow reserve (FFR) on the efficacy of coronary artery bypass grafting (CABG) in preventing graft failure. METHODS: Between January 2013 and December 2017, 48 patients underwent CABG after FFR was measured. Twenty-five grafts in 23 patients were evaluated for graft patency after the procedure. We studied stenosis of native coronary arteries, FFR, graft flow, graft patency, and the presence of pre-procedure and post-procedure myocardial ischemia. RESULTS: Three internal thoracic arteries showed the string sign, and two saphenous vein grafts showed occlusion. All target coronary arteries for these grafts had moderate (50-75%) stenosis. Of the 25 grafts, five failed, and 20 were successful. All grafts with the string sign had been bypassed for target coronary arteries with the gray-zone FFR value (0.75-0.80). No difference in graft flow was observed between the failed and successful grafts. Patients with graft failure had no postoperative myocardial ischemia in target areas despite graft condition. CONCLUSION: Internal thoracic artery graft for coronary arteries with the gray-zone FFR value may exhibit the string phenomenon. We believe that graft failure occurred because the target area had no ischemia before CABG. FFR is useful in pre-operative ischemic evaluation including scintigraphy and will influence the success of revascularization, including the selection of grafts.

Impact of preoperative nasopharyngeal cultures on surgical site infection after open heart surgery.

Objectives: Despite advances in surgical techniques and management, surgical site infection (SSI) is still important after cardiovascular surgery. We investigated to determine whether or not preoperative nasopharyngeal cultures (NCx) can predict SSI and its microbial spectrum. Methods: A retrospective review was done in 1226 consecutive patients undergoing NCx and cardiac and thoracic aortic surgery via median sternotomy who were cared for with the standard SSI bundle between 2013 and 2018. Microorganisms isolated from the NCx and SSI pathogens were counted to explore the microbial pattern and associated variables in patients with and without postoperative SSI. Perioperative management was not changed by collection of preoperative NCx. Results: There were 1281 and 127 microorganisms, including coagulase-negative Staphylococcus as the most prevalent, isolated from 784 nasal and 111 pharyngeal specimens, respectively. Postoperative SSI occurred in 31 patients (2.47%), including chest, groin, and leg SSI. Significant coincidence of the SSI pathogens with the NCx microorganisms was not observed. However, the patients with SSI showed significantly higher positive rates of preoperative NCx than those without SSI. The sensitivity/specificity of NCx for SSI were 81%/37% for nasal and 45%/92% for pharyngeal, respectively. The negative predictive value of NCx for ruling out SSI was 98.6% for nasal and 98.4% for pharyngeal, respectively. Independent risk factors for postoperative SSI included female sex, diabetes mellitus, positive preoperative NCx, and postoperative use of Portex Mini-Trach (Smiths Medical, Minneapolis, Minn) or tracheostomy on multivariate analysis. Conclusions: Preoperative NCx may be useful to predict SSI after open heart surgery via median sternotomy, as well as screening for methicillin-resistant Staphylococcus aureus.

Role of the carbonyl group of the (6-4) photoproduct in the (6-4) photolyase reaction.

The (6-4) photoproduct, which is one of the major UV-induced DNA lesions, causes carcinogenesis with high frequency. The (6-4) photolyase is a flavoprotein that can restore this lesion to the original bases, but its repair mechanism has not been elucidated. In this study, we focused on the interaction between the enzyme and the 3' pyrimidone component of the (6-4) photoproduct and prepared a substrate analogue in which the carbonyl group, a hydrogen-bond acceptor, was replaced with an imine, a hydrogen-bond donor, to investigate the involvement of this carbonyl group in the (6-4) photolyase reaction. UV irradiation of oligodeoxyribonucleotides containing a single thymine-5-methylisocytosine site yielded products with absorption bands at wavelengths longer than 300 nm, similar to those obtained from the conversion of the TT site to the (6-4) photoproduct. Nuclease digestion, MALDI-TOF mass spectrometry, and the instability of the products indicated the formation of the 2-iminopyrimidine-type photoproduct. Analyses of the reaction and the binding of the (6-4) photolyase using these oligonucleotides revealed that this imine analogue of the (6-4) photoproduct was not repaired by the (6-4) photolyase, although the enzyme bound to the oligonucleotide with considerable affinity. These results indicate that the carbonyl group of the 3' pyrimidone ring plays an important role in the (6-4) photolyase reaction. On the basis of these results, we discuss the repair mechanism.

Recognition and reaction mechanisms of the (6-4) photolyase as determined by using a (6-4) photoproduct analog.

The (6-4) photoproduct, which is one of the major UV-induced DNA lesions formed at bipyrimidine sites, causes carcinogenesis at high frequency. The (6-4) photolyases restore the (6-4) photoproducts to their intact bases in a light-dependent manner, but its overall repair mechanism remains obscure. To investigate the light-dependent conversion of the (6-4) photoproduct, we prepared a (6-4) photoproduct analog with modification at 3' pyrimidone ring, in which the carbonyl group was replaced with an imine to apply to the (6-4) photolyase assay. The (6-4) photolyase shows affinity to an oligonucleotide carrying this imine analog of the (6-4) photoproduct, though the imine analog is not repaired by the (6-4) photolyase.