高木 靖

As the current guidelines on myocardial revascularization recommend, transit-time flow measurement (TTFM) is increasingly used for intraoperative graft flow analysis during coronary artery bypass grafting (CABG) as a less invasive, more highly reproducible, and less time-consuming method. In addition to the morphological assessment using color Doppler, mean graft flow (Qm) > 15 ml/min, pulsatility index (PI) < 5.0, diastolic filling (DF) > 50%, and systolic reverse flow (SRF) < 4% have been reported to predict patent CABG grafts. However, it is difficult to determine the clear-cut cut-off value of these parameters, because they varies with the hemodynamic characters, including fractional flow reserve (FFR) of the target coronary artery. In addition to these parameters, we focused on fast Fourier transform (FFT) analysis, because the TTFM waveform morphology may be more important than Qm itself. FFT analysis is based on the principle that any periodic waveforms can be broken down into a series of pure sine waves or harmonics. Herein we review FFT analysis of the intraoperative TTFM waveforms for quality assessment of CABG grafts.

Background: We have employed a conservative management approach, including intensive control of both blood pressure and heart rate, in patients with aortic intramural hematoma (AIMH) and retrograde thrombosed type A acute aortic dissection (RT-TAAAD), sharing common clinical and imaging characteristics. Methods: To evaluate the outcomes of our conservative management approach, we retrospectively reviewed the clinical records of 98 patients diagnosed with AIMH or RT-TAAAD from January 2008 to March 2023. A conservative management approach was applied, except for those patients with an aortic diameter ≥ 55 mm, false lumen expansion, or cardiac tamponade, who underwent emergency aortic repair. Results: Besides 2 patients, who declined surgery and subsequently died from aortic rupture, 18 patients underwent urgent aortic surgery, while 78 did not. Multivariable logistic regression analysis identified the extrusion type of ulcer-like projections (ULPs) on admission and a maximum aortic diameter ≥ 45 mm on Day 1 as risk factors for acute aortic surgery. Among the 78 patients who were discharged, 9 (12%) underwent aortic surgery, while 69 (88%) did not, with a median follow-up of 44 months. The overall actuarial aortic surgery-free rates were 78% at 1 year and 72% at 5 years, respectively. A Cox proportional hazards analysis identified ULPs and an aortic diameter ≥ 45 mm at discharge as risk factors for late aortic surgery. Conclusions: The early and late outcomes of our conservative strategy for AIMH and RT-TAAAD demonstrate favorable surgery-free rates. The extrusion type of ULPs on admission and an aortic diameter ≥ 45 mm on Day 1 are predictors of acute aortic surgery, while ULPs and an aortic diameter ≥ 45 mm at discharge are predictors of late surgery.

UNLABELLED: 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.

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.

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.

We report wound management using a vacuum-assisted closure (VAC) system for the cannula sites of extracorporeal biventricular assist devices (BiVADs) for 295 days in a 23-year old Chinese female patient with fulminant giant cell myocarditis, who finally underwent heart transplantation. When the cannula sites appeared necrotic 3 months after BiVADs placement, she received negative pressure wound therapy prophylactically for four cannula sites, using a VAC system for 3 months, followed by no infections. Such prophylactic VAC therapy, using the skin barrier paste usually used for the ostomy pouching system to create a flatter surface and airtightness, may be useful to avoid cannula site infections, which is still a fatal complication causing sepsis, especially in patients with extracorporeal BiVADs.

BACKGROUND: Transit-time flow measurement (TTFM) is frequently used for intraoperative graft flow analysis during coronary artery bypass grafting (CABG). Although the TTFM results may be influenced by fractional flow reserve (FFR) of the target coronary artery as a determinant of coronary lesion-specific ischemia, the data has been limited. METHODS: We retrospectively investigated the relationships between the intraoperative TTFM parameters and preoperative FFR values of the target coronary arteries in 40 in-situ left internal thoracic artery (LITA) grafts to the left anterior descending artery (LAD), which were revealed to be patent on postoperative computed tomography angiography. RESULTS: The Spearman correlation coefficients of the TTFM parameters with FFR were as follows; maximum flow: -0.12 (p = 0.301), minimum flow (Qmin): -0.43 (p = 0.004), mean flow (Qm): -0.30 (p = 0.036), pulsatility index (PI): 0.37 (p = 0.012), diastolic filling (DF): -0.36 (p = 0.012), percent insufficiency (%Insuf): 0.45 (p = 0.002), and fast Fourier transform (FFT) ratio: -0.07 (p = 0.329). While Min and Qm showed significant negative correlation, PI and %Insuf showed significant positive correlation with FFR. CONCLUSIONS: Most TTFM parameters, including Qm, of the LITA graft to the LAD during CABG are strongly affected by preoperative FFR values. Since the FFT ratio is not influenced by FFR, FFT analysis of the TTFM may be recommend in the case of the in-situ LITA graft to the LAD with moderate stenosis with a higher FFR＞0.75.

BACKGROUND: Thoracic aortitis caused by Clostridium septicum is a rare infection with a strong association with malignancy and high mortality rate when left untreated. We report a case of surgical treatment for Stanford type A acute aortic dissection in a patient with C. septicum sepsis and thoracic aortitis. CASE PRESENTATION: A 63-year-old hypertensive man with rheumatoid arthritis presented with general malaise and diagnosed with C. septicum-infected aortitis with sepsis. On the 5th day of hospitalization, Stanford type A acute aortic dissection developed with severe aortic regurgitation. The patient underwent emergent surgical treatment successfully with excision of the infected ascending aorta and aortic root followed by replacement using a composite graft, followed by diagnosis of sigmoid colon cancer 7 months after aortic surgery. He was scheduled to undergo elective colon surgery. CONCLUSIONS: C. septicum aortitis can progress quickly, causing aneurysm or dissection. Therefore, in a patient with C. septicum aortitis, prompt surgical in situ graft replacement should be performed to debride the infected vascular lesions. Further investigations for gastrointestinal and hematological malignancies as a source of C. septicum should be also conducted.

OBJECTIVES: Postoperative acute kidney injury (AKI) is known as a risk factor for death after surgery for Stanford type A acute aortic dissection under hypothermic circulatory arrest. It may also adversely affect long-term survival. We searched for modifiable risk factors for postoperative AKI, focusing on lower body ischaemic time. METHODS: We reviewed 191 patients undergoing surgical repair for Stanford type A acute aortic dissection. The distal anastomosis depended on excluding the primary tear location, resulting in ascending/hemiarch (n = 119), partial arch (n = 18) and total arch replacement (n = 54). We defined an increase in the serum creatinine level to ≧2 times the baseline level as AKI. The incidence of AKI was investigated with multivariate analysis of its risk factors. RESULTS: Postoperative AKI was observed in 49 patients (26%), 31% of whom required renal replacement therapy. The overall hospital mortality rate was 8.5%. Postoperative AKI, preoperative shock and organ malperfusion were predictors of hospital death. Multivariate stepwise logistic regression analysis identified age, body mass index, preoperative chronic kidney disease and lower body ischaemic time as risk factors for postoperative AKI. CONCLUSIONS: Although surgical repair for Stanford type A acute aortic dissection showed favourable results, the incidence of postoperative AKI is still high, closely associated with hospital death. Lower body ischaemic time should be recognized specifically as a modifiable surgical risk factor for postoperative AKI.

腹部大動脈狭窄病変に対して、ステントグラフト脚を用いた血管内治療を2例経験したので文献的考察を加えて報告する。症例Iは79歳女性。下肢間歇性跛行と左足外側の有痛性潰瘍が認められ来院。CT検査にて腹部大動脈石灰化による高度狭窄と診断され、局所麻酔下にステントグラフト脚を留置した。術直後より症状軽快し歩行も可能となった。術後3ヵ月目には潰瘍の治癒も認めた。症例IIは74歳女性。62歳時に腹部大動脈閉塞病変に対するI型人工血管を用いた血行再建の手術歴がある。術後経過良好であったが、両下肢間歇性跛行が出現し来院。CT検査にてグラフト中枢側、末梢側吻合部の石灰化による高度狭窄を認めた。局所麻酔下にステントグラフト脚を留置し術直後より、症状の改善を認めた。(著者抄録)

<p>Objectives: Pulmonary endarterectomy (PEA) for chronic thromboembolic pulmonary hypertension (CTEPH) is technically demanding. We reviewed the surgical outcomes of consecutive patients who underwent PEA with aggressive use of pulmonary vasodilators, including epoprostenol sodium.</p><p>Methods: We retrospectively assessed perioperative clinical data of 122 patients with CTEPH who underwent PEA with hypothermic circulatory arrest between 2005 and 2013. Peri-operatively, all of the patients received pulmonary vasodilator therapy, including epoprostenol sodium and beraprost sodium.</p><p>Results: Patients were classified as having CTEPH type 1 (n=57), type 2 (n=32), and type 3 (n=33) disease according to the Jamison classification system. In-hospital mortality was 7.4% (n=9), caused by right heart failure (n=5), pulmonary hemorrhage (n=3), and pneumonia (n=1). The 113 patients who survived PEA showed significantly decreased mPAP (46±11 to 23±10 mmHg, P<0.01) and PVR (826±357 to 237±153 dyne·s^–1·cm^–5, P<0.01).</p><p>Conclusions: Aggressive pulmonary vasodilator treatment during surgical PEA results in favorable early outcomes. This treatment also leads to immediate and substantial improvement in pulmonary hemodynamics in patients with CTEPH.</p>