Venovenous extracorporeal membrane oxygenation (ECMO) is essential for patients with severe respiratory failure who do not respond to conventional mechanical ventilation. Adequate ECMO flow and safe circuit pressure are critical; however, cannula selection, which has a great impact on these factors, is often based on empirical judgment. This study aimed to develop a simple predictive method based on fluid dynamics for estimating ECMO flow rate and circuit pressures (P1: pre-pump, P2: pre-oxygenator, and P3: post-oxygenator). This experimental predictive model study compared the calculated and measured ECMO parameters across 36 combinations of cannula sizes, pump speeds, and bed heights. A laboratory-based ECMO circuit model was assembled with various drainage and return cannulas, an oxygenator, tubing, and a centrifugal pump. The circuit was primed with a 33

BACKGROUND: Inhaled nitric oxide is a selective pulmonary vasodilator commonly used to treat pulmonary hypertension and right ventricular failure. However, its effectiveness in treating right ventricular failure secondary to hypercapnia caused by abdominal compartment syndrome has not been well described. CASE PRESENTATION: This case describes a patient who developed severe hypercapnia and acute right ventricular failure due to abdominal compartment syndrome following massive intraoperative hemorrhage. Elevated intra-abdominal pressure impaired the respiratory mechanics, resulting in alveolar hypoventilation, hypercapnia, and acute pulmonary hypertension. Respiratory and circulatory failures progressively worsened. Administration of inhaled nitric oxide was associated with a rapid improvement in right ventricular afterload surrogates, leading to improved right ventricular output and enhanced carbon dioxide elimination, with concomitant improvement in systemic hemodynamics. DISCUSSION: Inhaled nitric oxide may serve as an effective rescue therapy for hypercapnia-induced pulmonary hypertension and acute right ventricular failure associated with abdominal compartment syndrome.

Passive leg raising (PLR) increases intrathoracic blood volume by redistributing blood from the lower to the upper body area. While inspiratory effort is hypothesized to have a similar effect due to pressure differences between the intrathoracic and extrathoracic cavities, direct evidence is scarce. Therefore, this study evaluated whether excessive inspiratory effort increases intrathoracic blood volume using end-expiratory lung impedance (EELI). Volunteers, fitted with electrical impedance tomography (EIT) belts, underwent a spontaneous breathing procedure in the supine position (control step). They breathed through a specialized face mask with separated inspiration and expiration routes (one-way valves) and their EELI was continuously recorded. First, PLR was performed. Subsequently, resistors (3-mm and 2-mm) were sequentially added to the mask’s inspiration route, requiring volunteers to increase inspiratory effort. A reference EELI was established during spontaneous breathing, and changes in EELI (ΔEELI) were calculated for each step (control, PLR, 3-mm, and 2-mm). ΔEELI values were compared using the Friedman test and Wilcoxon signed-rank test with Holm’s P value adjustment. Across 11 participants, the mean ΔEELI decreased by 13, 18, and 19 units for PLR, 3-mm, and 2-mm resistors, respectively. The Friedman test and Wilcoxon signed-rank test revealed significant differences between the control and each aforementioned intervention. PLR and increased inspiratory effort augment thoracic blood volume, thereby reducing EELI. UMIN000054238. April/23/2024.

BACKGROUND:Currently, clinical indicators for evaluating endothelial permeability in sepsis are unavailable. Endothelium-derived extracellular vesicles (EDEVs) are emerging as biomarkers of endothelial injury. Platelet endothelial cell adhesion molecule (PECAM) and vascular endothelial (VE)-cadherin are constitutively expressed endothelial intercellular adhesion molecules that regulate intercellular adhesion and permeability. Herein, we investigated the possible association between EDEVs expressing intercellular adhesion molecules (PECAM+ or VE-cadherin+ EDEVs) and endothelial permeability and sepsis severity. METHODS:Human umbilical vein endothelial cells (HUVECs) were stimulated with tumor necrosis factor alpha (TNF-α) directly or after pretreatment with permeability-modifying reagents such as angiopoietin-1, prostacyclin, or vascular endothelial growth factor (VEGF) to alter TNF-α-induced endothelial hyperpermeability. Endothelial permeability was measured using the dextran assay or transendothelial electrical resistance. Additionally, a prospective cross-sectional observational study was conducted to analyze circulating EDEV levels in patients with sepsis. EDEVs were examined in HUVEC culture supernatants or patient plasma (nonsepsis, n = 30; sepsis, n = 30; septic shock, n = 42) using flow cytometry. The Wilcoxon rank-sum test was used for comparisons between 2 groups. Comparisons among 3 or more groups were performed using the Steel-Dwass test. Spearman's test was used for correlation analysis. Statistical significance was set at P < .05. RESULTS:TNF-α stimulation of HUVECs significantly increased EDEV release and endothelial permeability. Pretreatment with angiopoietin-1 or prostacyclin suppressed the TNF-α-induced increase in endothelial permeability and inhibited the release of PECAM+ and VE-cadherin+ EDEVs. In contrast, pretreatment with VEGF increased TNF-α-induced endothelial permeability and the release of PECAM+ and VE-cadherin+ EDEVs. However, pretreatment with permeability-modifying reagents did not affect the release of EDEVs expressing inflammatory stimulus-inducible endothelial adhesion molecules such as E-selectin, intracellular adhesion molecule-1, or vascular cell adhesion molecule-1. The number of PECAM+ EDEVs on admission in the septic-shock group (232 [124, 590]/μL) was significantly higher (P = .043) than that in the sepsis group (138 [77,267]/μL), with an average treatment effect of 98/μL (95% confidence interval [CI], 2-270/μL), and the number of VE-cadherin+ EDEVs in the septic-shock group (173 [76,339]/μL) was also significantly higher (P = .004) than that in the sepsis group (81 [42,159]/μL), with an average treatment effect (ATE) of 79/μL (95% CI, 19-171/μL); these EDEV levels remained elevated until day 5. CONCLUSIONS:EDEVs expressing intercellular adhesion molecules (PECAM+ or VE-cadherin+ EDEVs) may reflect increased endothelial permeability and could be valuable diagnostic and prognostic markers for sepsis.

Background Esophagectomy is a high-risk procedure that can involve serious postoperative complications. There has been an increase in the number of minimally invasive esophagectomies (MIEs) being performed. However, the relationship between intraoperative management and postoperative complications in MIE remains unclear. Methods After the institutional review board approval, we enrolled 300 patients who underwent MIE at Tohoku University Hospital between April 2016 and March 2021. The relationships among patient characteristics, intraoperative and perioperative factors, and postoperative complications were retrospectively analyzed. The primary outcome was the relationship between intraoperative fluid volume and anastomotic leakage, and the secondary outcomes included the associations between other perioperative factors and postoperative complications. Results Among 300 patients, 28 were excluded because of missing data; accordingly, 272 patients were included in the final analysis. The median [interquartile range] operative duration was 599 [545–682] minutes; total intraoperative infusion volume was 3,747 [3,038–4,399] mL; total infusion volume per body weight per hour was 5.48 [4.42–6.73] mL/kg/h; and fluid balance was + 2,648 [2,015–3,263] mL. The postoperative complications included anastomotic leakage in 68 (25%) patients, recurrent nerve palsy in 91 (33%) patients, pneumonia in 62 (23%) patients, cardiac arrhythmia in 13 (5%) patients, acute kidney injury in 5 (2%) patients, and heart failure in 5 (2%) patients. The Cochrane-Armitage trend test indicated significantly increased anastomotic leakage among patients with a relatively high total infusion volume ( P = 0.0085). Moreover, anastomotic leakage was associated with male sex but not with peak serum lactate levels. Patients with a longer anesthesia duration or recurrent nerve palsy had a significantly higher incidence of postoperative pneumonia than those without. Further, the incidence of postoperative pneumonia was not associated with the operative duration, total infusion volume, or fluid balance. The operative duration and blood loss were related to the total infusion volume. Acute kidney injury was not associated with the total infusion volume or serum lactate levels. Conclusions Among patients who underwent MIE, the total infusion volume was positively correlated with the incidence of anastomotic leakage. Further, postoperative pneumonia was associated with recurrent nerve palsy but not total infusion volume or fluid balance.

Background/Aims: Adrenaline quickly inhibits the release of histamine from mast cells. Besides beta 2-adrenergic receptors, several in vitro studies also indicate the involvement of alpha-adrenergic receptors in the process of exocytosis. Since exocytosis in mast cells can be detected electrophysiologically by the changes in the membrane capacitance (Cm), its continuous monitoring in the presence of drugs would determine their mast cell-stabilizing properties. Methods: Employing the whole-cell patch-clamp technique in rat peritoneal mast cells, we examined the effects of adrenaline on the degranulation of mast cells and the increase in the Cm during exocytosis. We also examined the degranulation of mast cells in the presence or absence of alpha-adrenergic receptor agonists or antagonists. Results: Adrenaline dose-dependently suppressed the GTP-gamma-S-induced increase in the Cm and inhibited the degranulation from mast cells, which was almost completely erased in the presence of butoxamine, a beta 2-adrenergic receptor antagonist. Among alpha-adrenergic receptor agonists or antagonists, high dose prazosin, a selective alpha 1-adrenergic receptor antagonist, significantly reduced the ratio of degranulating mast cells and suppressed the increase in the Cm. Additionally, prazosin augmented the inhibitory effects of adrenaline on the degranulation of mast cells. Conclusion: This study provided electrophysiological evidence for the first time that adrenaline dose-dependently inhibited the process of exocytosis, confirming its usefulness as a potent mast cell-stabilizer. The pharmacological blockade of alpha 1-adrenergic receptor by prazosin synergistically potentiated such mast cell-stabilizing property of adrenaline, which is primarily mediated by beta 2-adrenergic receptors. (c) 2024 The Author(s). Published by Cell Physiol Biochem Press GmbH&Co. KG

OBJECTIVES:The clinical use of less-invasive devices that calculate the cardiac output from arterial pressure waveform is increasing. The authors aimed to evaluate the accuracy and characteristics of the systemic vascular resistance index (SVRI) of the cardiac index measured by 2 less-invasive devices, fourth-generation FloTrac (CIFT) and LiDCOrapid (CILR), compared with the intermittent thermodilution technique, using a pulmonary artery catheter (CITD). DESIGN:This was a prospective observational study. SETTING:This study was conducted at a single university hospital. PARTICIPANTS:Twenty-nine adult patients undergoing elective cardiac surgery. INTERVENTIONS:Elective cardiac surgery was used as an intervention. MEASUREMENTS AND MAIN RESULTS:Hemodynamic parameters, CIFT, CILR, and CITD, were measured after the induction of general anesthesia, at the start of cardiopulmonary bypass, after completion of weaning from cardiopulmonary bypass, 30 minutes after weaning, and at sternal closure (135 measurements in total). The CIFT and CILR had moderate correlations with CITD (r = 0.62 and 0.58, respectively). Compared with CITD, CIFT, and CILR had a bias of -0.73 and -0.61 L/min/m2, limit of agreement of -2.14-to-0.68 L/min/m2 and -2.42-to-1.20 L/min/m2, and percentage error of 39.9% and 51.2%, respectively. Subgroup analysis for evaluating SVRI characteristics showed that the percentage errors of CIFT and CILR were 33.9% and 54.5% in low SVRI (<1,200 dyne×s/cm5/m), 37.6% and 47.9% in moderate SVRI (1,200-1,800 dyne×s/cm5/m), 49.3% and 50.6% in high SVRI (>1,800 dyne·s/cm5/m2), respectively. CONCLUSIONS:The accuracy of CIFT or CILR was not clinically acceptable for cardiac surgery. Fourth-generation FloTrac was unreliable in high SVRI. LiDCOrapid was inaccurate across a broad range of SVRI, and minimally affected by SVRI.

BACKGROUND:Tetralogy of Fallot (TOF) is a complex cyanotic congenital heart disease. As most patients with TOF undergo palliative or radical surgical repair during childhood, cardiac surgery under cardiopulmonary bypass (CPB) for adult survivors with unrepaired TOF is exceedingly rare.CASE PRESENTATION:A 41-year-old woman with unrepaired TOF, pulmonary atresia (PA), and major aortopulmonary collateral arteries (MAPCAs) developed acute infectious endocarditis (IE). As vegetation gradually increased despite intravenous antibiotic administration, she was scheduled for urgent aortic valve replacement under CPB. Pulmonary blood flow was primarily provided by the MAPCAs originating from the descending aorta. Intra-aortic balloon occlusion for MAPCAs was performed to ensure a bloodless surgical field. Aortic valve replacement was successful.CONCLUSION:An adult with uncorrected TOF developed acute IE and subsequently had successful cardiac surgery under CPB. Understanding TOF physiology with PA and MAPCAs, particularly pulmonary blood flow through MAPCAs, is crucial.

OBJECTIVES: Standard bilateral lung transplantation (BLT) is not feasible for patients with pulmonary arterial hypertension (PAH) complicated with a giant pulmonary arterial aneurysm (PAA). This study aimed to describe the outcomes of BLT with pulmonary artery reconstruction (PAR) using donor aorta for such patients. METHODS: This is a retrospective single-centre study reviewing PAH patients with a PAA who received BLT with PAR using donor aorta from January 2010 through December 2020. We compared the characteristics and short- and long-term outcomes of recipients receiving PAR (PAR group) with those who had no PAA and received standard BLT (non-PAR group). RESULTS: Nineteen adult PAH patients underwent cadaveric lung transplantation during the study period. Among them, 5 patients with a giant PAA (median pulmonary artery trunk diameter, 69.9 mm) underwent BLT with PAR using donor aorta and the others received standard BLT. Although the operation time tended to be longer in the PAR group compared with the non-PAR group (1239 vs 958 mins, P = 0.087), 90-day mortality (PAR group: 0% vs non-PAR group: 14.3%, P > 0.99), and 5-year survival rate (PAR group: 100% vs non-PAR group: 85.7%, P=0.74) was comparable between the groups. No dilatation, constriction or infection of the aortic grafts were recorded during the study period with a median follow-up time of 94 months in the PAR group. CONCLUSIONS: Lung transplantation with PAR using donor aorta is a valid surgical option for PAH patients complicated with a giant PAA.

In mechanically ventilated severe acute respiratory distress syndrome patients, spontaneous inspiratory effort generates more negative pressure in the dorsal lung than in the ventral lung. The airflow caused by this pressure difference is called pendelluft, which is a possible mechanisms of patient self-inflicted lung injury. This study aimed to use computer simulation to understand how the endotracheal tube and insufficient ventilatory support contribute to pendelluft. We established two models. In the invasive model, an endotracheal tube was connected to the tracheobronchial tree with 34 outlets grouped into six locations: the right and left upper, lower, and middle lobes. In the non-invasive model, the upper airway, including the glottis, was connected to the tracheobronchial tree. To recreate the inspiratory effort of acute respiratory distress syndrome patients, the lower lobe pressure was set at -13 cmH2O, while the upper and middle lobe pressure was set at -6.4 cmH2O. The inlet pressure was set from 10 to 30 cmH2O to recreate ventilatory support. Using the finite volume method, the total flow rates through each model and toward each lobe were calculated. The invasive model had half the total flow rate of the non-invasive model (1.92 L/s versus 3.73 L/s under 10 cmH2O, respectively). More pendelluft (gas flow into the model from the outlets) was observed in the invasive model than in the non-invasive model. The inlet pressure increase from 10 to 30 cmH2O decreased pendelluft by 11% and 29% in the invasive and non-invasive models, respectively. In the invasive model, a faster jet flowed from the tip of the endotracheal tube toward the lower lobes, consequently entraining gas from the upper and middle lobes. Increasing ventilatory support intensifies the jet from the endotracheal tube, causing a venturi effect at the bifurcation in the tracheobronchial tree. Clinically acceptable ventilatory support cannot completely prevent pendelluft.

The endotracheal tubes (ETTs) used for children have a smaller inner diameter. Accordingly, the resistance across ETT (R-ETT) is higher. Theoretically, shortening the ETTs can decrease total airway resistance (R-total), because R-total is sum of R-ETT and patient's airway resistance. However, the effectiveness of ETT shortening for mechanical ventilation in the clinical setting has not been reported. We assessed the effectiveness of shortening a cuffed ETT for decreasing R-total, and increasing tidal volume (TV), and estimated the R-ETT/R-total ratio in children. In anesthetized children in a constant pressure-controlled ventilation setting, R-total and TV were measured with a pneumotachometer before and after shortening a cuffed ETT. In a laboratory experiment, the pressure gradient across the original length, shortened length, and the slip joint alone of the ETT were measured. We then determined the R-ETT/R-total ratio using the above results. The clinical study included 22 children. The median ETT percent shortening was 21.7%. Median R-total was decreased from 26 to 24 cmH(2)O/L/s, and median TV was increased by 6% after ETT shortening. The laboratory experiment showed that ETT length and the pressure gradient across ETT are linearly related under a certain flow rate, and approximately 40% of the pressure gradient across the ETT at its original length was generated by the slip joint. Median R-ETT/R-total ratio were calculated as 0.69. The effectiveness of ETT shortening on R-total and TV was very limited, because the resistance of the slip joint was very large.

Background:von Willebrand factors (vWFs), hemostatic factors, are produced as large multimers and are shear stress-dependently cleaved to become the appropriate size. A reduction in vWF large multimers develops in various conditions including the use of extracorporeal life support, which can cause excessive-high shear stress in the blood flow and result in hemostatic disorders. The objective of this prospective study was to investigate the impact of venovenous extracorporeal membrane oxygenation (VV ECMO) use on the status of vWF large multimers and hemostatic disorders during single lung transplantation (SLT).Methods:We prospectively enrolled 12 patients who underwent SLT at our center. Among them, seven patients were supported by VV ECMO intraoperatively (ECMO group) and the remaining five patients underwent SLT without ECMO support (control group). The vWF large multimer index (%) was defined as the ratio of the large multimer proportion in total vWF (vWF large multimer ratio) derived from a patient's plasma to that from standard human plasma.Results:The vWF large multimer index at the end of the surgery was significantly lower in the ECMO group than in the control group (112.6% vs. 75.8%, respectively; P<0.05). The intraoperative blood loss and the amounts of intraoperative transfusion products in the ECMO group tended to be greater than those in the control group; however, the differences were not significant.Conclusions:During SLT, the use of VV ECMO caused a decrease in the vWF large multimer index. The short duration of time of VV ECMO use in our study did not significantly affect the intra- and postoperative outcomes including blood loss, blood transfusion, and re-exploration thoracotomy for bleeding. Nevertheless, to comprehensively evaluate the actual influence of this decrease in the vWF large multimer index on intra- and postoperative outcomes, a multicenter larger-scale study is warranted.

呼吸器外科手術の適応は，切除可能性，呼吸機能，身体機能，片肺換気が実施可能かを評価し決定する．呼吸機能は，術後予測1秒量や肺拡散能が正常値の30%未満はリスクが高い．身体機能は，運動耐容能試験で最大酸素摂取量10mL/kg/min未満は非常にリスクが高い．片肺換気はガス交換と循環に大きく影響する．その実施可能性は，術前の血液ガス分析値，運動耐容能，肺高血圧症と右心不全の有無，片肺換気時の予測最大一回換気量等で評価する．低耐術能患者には合併疾患への術前介入やプレハビリテーションを行い，リスク因子改善と状態適正化後に手術適応を判断する．プレハビリテーションはリスクの管理から低減への転換である．

Fluid mechanics show that high-density gases need more energy while flowing through a tube. Thus, high-density anesthetic gases consume more energy to flow and less energy for lung inflation during general anesthesia. However, its impact has not been studied. Therefore, this study aimed to investigate the effects of high-density anesthetic gases on tidal volume in laboratory and clinical settings. In the laboratory study, a test lung was ventilated at the same pressure-controlled ventilation with 22 different gas compositions (density range, 1.22-2.27 kg/m(3)) using an anesthesia machine. A pneumotachometer was used to record the tidal volume of the test lung and the respiratory gas composition; it showed that the tidal volume of the test lung decreased as the respiratory gas density increased. In the clinical study, the change in tidal volume per body weight, accompanied by gas composition change (2% sevoflurane in oxygen and with 0-30-60% of N2O), was recorded in 30 pediatric patients. The median tidal volume per body weight decreased by 10% when the respiratory gas density increased from 1.41 kg/m(3) to 1.70 kg/m(3), indicating a significant between-group difference (P < 0.0001). In both settings, an increase in respiratory gas density decreased the tidal volume during pressure-controlled ventilation, which could be explained by the fluid dynamics theory. This study clarified the detailed mechanism of high-density anesthetic gas reduced the tidal volume during mechanical ventilation and revealed that this phenomenon occurs during pediatric anesthesia, which facilitates further understanding of the mechanics of ventilation during anesthesia practice and respiratory physiology.

OBJECTIVES: The objective of the present study was to examine the effect of venovenous (VV) extracorporeal membrane oxygenation (ECMO) use on the haemodynamics during single lung transplantation (SLT) and postoperative course. METHODS: Forty-seven patients who underwent SLT for end-stage lung diseases in our lung transplant centre between January 2010 and December 2019 were included in this study. The recipients were divided into 3 groups according to the type of intraoperative ECMO. No type of ECMO was intra-operatively used in the patients of the no use of ECMO (NO ECMO) group. The patients in the venoarterial (VA) and VV ECMO groups were put on VA and VV ECMO during the surgery, respectively. The data were compared among the 3 groups. RESULTS: There were 13 SLT cases in the NO ECMO group, 23 SLT cases in the VA ECMO group and 11 SLT cases in the VV ECMO group. Re-exploration for bleeding was performed in 3 (13.0%) recipients in the VA ECMO group. No recipients required re-exploration in the other groups. In the NO ECMO group, systolic pulmonary arterial pressure (PAP) was significantly elevated during the main pulmonary artery clamp on the SLT side and it was decreased in the VA ECMO group because of the bypass flow. Interestingly, systolic PAP was significantly decreased in the VV ECMO group as well. CONCLUSIONS: VV ECMO decreases the PAP during SLT, which could be a choice for extracorporeal life support during lung transplant surgery for patients, even those with pulmonary hypertension.

Background:There are no known predictors of extracorporeal membrane oxygenation (ECMO) induction for single lung transplantation.Objective:The purpose of the present study was to clarify the relationship between variables and ECMO requirements in single lung transplantation.Methods:This study included adult patients who underwent cadaveric single lung transplantation between 2010 and 2019. After general anesthesia, the transplanted lungs were ventilated in all cases. The analysis included 38 patients in the ECMO required (RQ) group and 12 patients in the ECMO non-required (FR) group. Comparisons were made between the two groups for data affecting ECMO implementation, and data that were significantly different were subjected to multivariate analysis.Results:Prior to anesthesia, the bicarbonate (HCO3-) value of the FR group was lower than that of the RQ group (24.6±2.7 vs. 29.7±5.3 mmol/L, p=0.005). Multivariate analysis showed that the cut-off bicarbonate value was 29.6. The area under the receiver operating characteristic curve (AUROC) of the model was 0.869 (R2: 0.331), with a sensitivity of 79% and a specificity of 88%. The odds ratio was 1.63 for every unit increase in the bicarbonate value (95%CI: 1.11-2.39, p<0.001). Further, the FR group had higher arterial blood pressure (mean: 79.0±11.5 vs. 68.9±8.3 mmHg, p=0.030), less blood loss (432±385 vs. 1,623±1,997 g, p<0.001), shorter operation time (417±44 vs. 543±111 min, p<0.001), and shorter ICU stay (11±9 vs. 25±38 days, p=0.039).Conclusion:Preoperative evaluation of bicarbonate could predict the need for ECMO for single lung transplantation.

AN INTRACARDIAC left-to-right shunt increases pulmonary blood flow and pulmonary artery (PA) pressure (PAP), a condition that can cause pulmonary vascular injury and result in the development of Eisenmenger syndrome (ES) in the terminal stage. Moreover, the extreme increase in pulmonary blood flow and/or pulmonary vascular resistance (PVR) is associated with giant PA aneurysms (PAAs); however, these cases are rare. 1 Butto F Lucas Jr, RV Edwards JE Pulmonary arterial aneurysm. A pathologic study of five cases. Chest. 1987; 91: 237-241 Abstract Full Text Full Text PDF PubMed Scopus (80) Google Scholar For patients with ES and giant PAA, heart-lung transplantation (HLTx) or, alternatively, bilateral lung transplantation (BLTx), combined with intracardiac repair and PA replacement, are the only 2 available life-saving interventions. 2 Noda M Okada Y Saiki Y et al. Reconstruction of pulmonary artery with donor aorta and autopericardium in lung transplantation. Ann Thorac Surg. 2013; 96: e17-e19 Abstract Full Text Full Text PDF PubMed Scopus (12) Google Scholar ,3 Toyama H Saito K Takei Y et al. Two cases of bilateral lung transplantation combined with intracardiac repair and pulmonary artery replacement: perioperative managements based on the left ventricular function. J Anesth. 2015; 29: 957-961 Crossref PubMed Scopus (3) Google Scholar In patients with severe pulmonary arterial hypertension (PAH), PVR elevation, low systemic pressure, and high airway pressure should be avoided during anesthesia, as all these factors can induce right ventricular (RV) failure and create a lethal situation. Additionally, a giant PAA sometimes can compress the coronary arteries and airways, which can cause coronary ischemia and airway obstruction after anesthesia induction. In such cases, venoarterial (VA) extracorporeal membrane oxygenation (ECMO) often is used. 4 Ius F Tudorache I Warnecke G. Extracorporeal support, during and after lung transplantation: The history of an idea. J Thorac Dis. 2018; 10: 5131-5148 Crossref PubMed Scopus (30) Google Scholar However, when peripheral VA ECMO is used in patients with narrowed peripheral arteries, the return flow can decrease, and the mixing point of the patient's arterial blood with the ECMO's return flow can move to the distal portion of the aortic arch, 5 Alwardt CM Patel BM Lowell A et al. Regional perfusion during venoarterial extracorporeal membrane oxygenation: A case report and educational modules on the concept of dual circulations. J Extra Corpor Technol. 2013; 45: 187-194 PubMed Google Scholar a situation that can cause watershed phenomena and/or hypoxic encephalopathy (Harlequin syndrome). 6 Avgerinos DV DeBois W Voevidko L et al. Regional variation in arterial saturation and oxygen delivery during venoarterial extracorporeal membrane oxygenation. J Extra Corpor Technol. 2013; 45: 183-186 PubMed Google Scholar ,7 Napp LC Kühn C Hoeper MM et al. Cannulation strategies for percutaneous extracorporeal membrane oxygenation in adults. Clin Res Cardiol. 2016; 105: 283-296 Crossref PubMed Scopus (149) Google Scholar Herein, the authors report the management of BLTx in a patient with ES, severe PAH, giant PAA, a constricted trachea and right bronchus, and an interruption of the inferior vena cava (IVC) with azygos and hemiazygos continuation. As the authors believed that the constricted trachea and right bronchus could become obstructed and cause ventilation difficulties after general anesthesia induction, they initially had deemed it safer to use VA ECMO for the patient. However, it would have been impossible to ensure sufficient VA ECMO because of the patient's narrowed axillary and femoral arteries. To solve these problems, a drainage cannula was placed in the azygos vein, a return cannula was placed in the right atrium (RA), and venovenous (VV) ECMO was established before the induction of general anesthesia.

PurposeGiant pulmonary arterial aneurysm (PAA) is a rare but serious complication for patients with pulmonary hypertension (PH). Heart-lung transplantation or lung transplantation with a full length of donor pulmonary artery (PA) for pulmonary artery reconstruction (PAR) are options for PH complicated with a giant PAA involving PA trunk to main PAs. We have been using donor aorta for the reconstruction of PA for these lung transplant cases. This study aimed to describe our intermediate-term outcomes of lung transplantation with PAR using donor aorta for PH complicated with a giant PAA.MethodsThis is a single center retrospective review from March 2000 to May 2020. We reviewed cadaveric lung transplantations for PH and compared the outcomes of lung transplantation with PAR (PAR group) with those without PAR (non-PAR group).ResultsTwenty-five PH patients underwent cadaveric lung transplantation. Among them, 5 patients with a giant PAA underwent lung transplantation with PAR using donor aorta. Representative 3D-CT images of a giant PAA and the reconstructed PA are shown in Figure A. The diameter of the PA trunk was significantly larger in the PAR group compared to the non-PAR group (Figure B). As expected, operative time was significantly longer in the PAR group compared to the non-PAR group (PAR, 1204 minutes; non-PAR, 965 minutes, p=0.035). On the other hand, primary graft dysfunction grade, 30-day mortality (PAR, 0%; non-PAR, 5.0%), 5-year survival rate (PAR, 100%; non-PAR, 73.9%, Figure C), and 6 minutes walk distance at 1 year after lung transplantation (PAR, 522 m; non-PAR, 526m) were not significantly different between the groups. The donor aortas used for PAR did not show constriction, obstruction, enlargement, or infection during the observation period.ConclusionOur experience supports that lung transplantation with PAR using donor aorta is a feasible surgical option for PH complicated with a giant PAA. Giant pulmonary arterial aneurysm (PAA) is a rare but serious complication for patients with pulmonary hypertension (PH). Heart-lung transplantation or lung transplantation with a full length of donor pulmonary artery (PA) for pulmonary artery reconstruction (PAR) are options for PH complicated with a giant PAA involving PA trunk to main PAs. We have been using donor aorta for the reconstruction of PA for these lung transplant cases. This study aimed to describe our intermediate-term outcomes of lung transplantation with PAR using donor aorta for PH complicated with a giant PAA. This is a single center retrospective review from March 2000 to May 2020. We reviewed cadaveric lung transplantations for PH and compared the outcomes of lung transplantation with PAR (PAR group) with those without PAR (non-PAR group). Twenty-five PH patients underwent cadaveric lung transplantation. Among them, 5 patients with a giant PAA underwent lung transplantation with PAR using donor aorta. Representative 3D-CT images of a giant PAA and the reconstructed PA are shown in Figure A. The diameter of the PA trunk was significantly larger in the PAR group compared to the non-PAR group (Figure B). As expected, operative time was significantly longer in the PAR group compared to the non-PAR group (PAR, 1204 minutes; non-PAR, 965 minutes, p=0.035). On the other hand, primary graft dysfunction grade, 30-day mortality (PAR, 0%; non-PAR, 5.0%), 5-year survival rate (PAR, 100%; non-PAR, 73.9%, Figure C), and 6 minutes walk distance at 1 year after lung transplantation (PAR, 522 m; non-PAR, 526m) were not significantly different between the groups. The donor aortas used for PAR did not show constriction, obstruction, enlargement, or infection during the observation period. Our experience supports that lung transplantation with PAR using donor aorta is a feasible surgical option for PH complicated with a giant PAA.

Although single-lung transplant on the side with better lung function is challenging in patients with significantly asymmetrical lung function between the right and left sides, it sometimes can be a realistic option because of the recipient's condition and from the viewpoint of organ sharing. We report our experience with a successful case of single-lung transplant on the side with a pulmonary perfusion ratio of 89%. The transplant was performed with the patient under central venoarterial extracorporeal membrane oxygenation through a clamshell incision, and the patient had an acceptable short-and long-term outcome with a remarkable improvement of lung function.