[Inhaled Nitric Oxide Therapy Using High-flow Nasal Cannula in Adults After Open Heart Surgery].

Inhaled nitric oxide( iNO) therapy is commonly used to improve pulmonary hypertension and oxygenation in adult patients undergoing open heart surgery, mostly being applied to mechanical ventilation (MV). We often face rebound of pulmonary artery pressure (PAP) after reduction or discontinuation of iNO therapy, resulting in prolonged MV. Twenty-three cases, to which iNO therapy during MV (MV-iNO) were initiated, then continuously treated with iNO therapy using high-flow nasal cannula (HFNC-iNO) after extubation, were retrospectively investigated. During MV-iNO, mean PAP( mPAP) was significantly lower than before starting iNO therapy (p<0.001). Also, mPAP on HFNC-iNO was significantly lower than mPAP before iNO therapy during MV (p<0.001). There was no significant difference of mPAP between MV-iNO and HFNC-iNO (p=0.38). MV was discontinued in 330 minutes (median), oxygenation was maintained after switching from MV-iNO to HFNC-iNO and there were no cases of reintubation, perioperative mortality, or adverse events due to iNO therapy. HFNC-iNO is considered as useful method in maintaining decreased mPAP and improved oxygenation after extubation in adult patients after open heart surgery.

Regenerative and durable small-diameter graft as an arterial conduit.

Despite significant research efforts, clinical practice for arterial bypass surgery has been stagnant, and engineered grafts continue to face postimplantation challenges. Here, we describe the development and application of a durable small-diameter vascular graft with tailored regenerative capacity. We fabricated small-diameter vascular grafts by electrospinning fibrin tubes and poly(ε-caprolactone) fibrous sheaths, which improved suture retention strength and enabled long-term survival. Using surface topography in a hollow fibrin microfiber tube, we enable immediate, controlled perfusion and formation of a confluent endothelium within 3-4 days in vitro with human endothelial colony-forming cells, but a stable endothelium is noticeable at 4 weeks in vivo. Implantation of acellular or endothelialized fibrin grafts with an external ultrathin poly(ε-caprolactone) sheath as an interposition graft in the abdominal aorta of a severe combined immunodeficient Beige mouse model supports normal blood flow and vessel patency for 24 weeks. Mechanical properties of the implanted grafts closely approximate the native abdominal aorta properties after just 1 week in vivo. Fibrin mediated cellular remodeling, stable tunica intima and media formation, and abundant matrix deposition with organized collagen layers and wavy elastin lamellae. Endothelialized grafts evidenced controlled healthy remodeling with delayed and reduced macrophage infiltration alongside neo vasa vasorum-like structure formation, reduced calcification, and accelerated tunica media formation. Our studies establish a small-diameter graft that is fabricated in less than 1 week, mediates neotissue formation and incorporation into the native tissue, and matches the native vessel size and mechanical properties, overcoming main challenges in arterial bypass surgery.

Venous Properties in a Fontan Patient with Successful Remission of Protein-Losing Enteropathy.

We present the case of a 1-year-old boy who developed protein-losing enteropathy (PLE) within 2 months of a fenestrated Fontan procedure. His fenestration rapidly closed despite bilateral pulmonary stenosis (BPS). Subsequent to PLE onset, both fenestration and the bilateral pulmonary artery were reconstructed, and the patient's PLE had been in remission, with additive use of medications, for more than 2 years. Notably, although fenestration closed again and central venous pressure (CVP) reduction was minimal, the surrogates of venous return resistance were markedly suppressed as shown by increased blood volume, reduced estimated mean circulatory filling pressure, and suppressed CVP augmentation against a contrast agent. Taken together, dynamic characteristics of venous stagnation, rather than the absolute value of CVP, were ameliorated by the pulmonary reconstruction and use of medications, suggesting a significant role of venous property in the physiology of PLE. In addition, simultaneous measures of CVP and ventricular end-diastolic pressure during the abdominal compression procedure suggested a limited therapeutic role of fenestration against PLE in this patient.

Echocardiogram Unmasked Hemodynamic Advantage of Atrial Pacing in Securing Ventricular Preload in a Fontan Patient with Junctional Rhythm.

While the advancement of perioperative management has expanded Fontan candidacy, not all patients have a successful postoperative course. Our case was a right isomerism patient who could not leave the ICU due to high central venous pressure and low output syndrome. Initial observation of the monitor ECG showed his rhythm to be supraventricular, however, an echocardiogram indicated simultaneous contraction of the atrium and ventricle, implying a junctional rhythm. While neither central venous pressure nor blood pressure improved with temporary pacing, better central venous and pulmonary venous blood flow patterns during pacing unraveled its positive impact. The patient successfully left the ICU after permanent pacing implantation. Hemodynamic study revealed a beneficial impact of atrial pacing in securing cardiac output and ventricular preload, lowering central venous pressure, and shortening blood transit time, which is partly attributed to the optimization of the fenestration function in reservation of the preload. Our case emphasizes the significant advantage of atrial pacing in a failing Fontan patient with junctional rhythm by reducing venous congestion and maximizing the benefit of fenestration.

[Extraction of a 36-year-old Pacemaker Lead Using Cardiopulmonary Bypass].

A 78-year-old man underwent pacemaker implantation via the left internal jugular vein 36 years ago. After 30 years, a new device was implanted via the right subclavian vein and the old lead was cut and buried underneath the skin due to infection. This time, the patient presented with persistent lead infection of the left side. We chose open heart surgery to excise the old lead because of severe adhesion and surrounding calcification. The infected lead was completely removed using cardiopulmonary bypass without complication. Old pacemaker leads tend to develop adhesion and calcification within the innominate vein and superior vena cava, and therefore, it is often difficult to remove it with percutaneous technique. It was considered that open heart surgery was useful to excise a very old pacemaker lead.

3D bioprinting using stem cells.

Recent advances have allowed for three-dimensional (3D) printing technologies to be applied to biocompatible materials, cells and supporting components, creating a field of 3D bioprinting that holds great promise for artificial organ printing and regenerative medicine. At the same time, stem cells, such as human induced pluripotent stem cells, have driven a paradigm shift in tissue regeneration and the modeling of human disease, and represent an unlimited cell source for tissue regeneration and the study of human disease. The ability to reprogram patient-specific cells holds the promise of an enhanced understanding of disease mechanisms and phenotypic variability. 3D bioprinting has been successfully performed using multiple stem cell types of different lineages and potency. The type of 3D bioprinting employed ranged from microextrusion bioprinting, inkjet bioprinting, laser-assisted bioprinting, to newer technologies such as scaffold-free spheroid-based bioprinting. This review discusses the current advances, applications, limitations and future of 3D bioprinting using stem cells, by organ systems.

Cerebral oximetry for cardiac surgery: a preoperative comparison of device characteristics and pitfalls in interpretation.

Regional cerebral oximetry using near-infrared spectroscopy devices is commonly used for detecting cerebral ischemia during cardiopulmonary bypass, and aim to avoid poor cerebral perfusion which may result in perioperative neurological impairment. Today, several devices that can detect cerebral ischemia are commercially available. Although these devices operate on the same measurement principles, their algorithms for detecting and calculating cerebral ischemia are different and no criteria for directly comparing values measured by such different devices exist. From January 2017 to August 2017, 80 adult cardiovascular surgery patients were enrolled in the prospective study. In each patient, preoperative regional cerebral oxygen saturation values were measured by two different devices and their correlations with various preoperative factors were evaluated. Regional cerebral oxygen saturation levels were significantly higher for values of FORE-SIGHT ELITE (CAS Medical Systems, Branford, CT, USA) (F value) than those of the INVOS 5100C (Medtronic, Minneapolis, MN, USA) (I value). Scalp-cortex distance, hemoglobin concentration, and the presence or absence of hemodialysis showed significant correlations with ratios of measured values specific to each device (F/I). An appropriate device should be selected according to preoperative patient characteristics, and factors influencing regional cerebral oxygen saturation values should be considered to ensure the correct interpretation of measured values. This research was conducted with the approval of the ethics committee of our university (approval number: B16-96).

Correction to: Cerebral oximetry for cardiac surgery: a preoperative comparison of device characteristics and pitfalls in interpretation.

In the original publication, the length unit of the SCD in Table 1 and Fig. 2 has been incorrectly published as cm. The correct length unit is mm.

Early Extubation in the Operating Room after Congenital Open-Heart Surgery.

Early extubation in the operating room after congenital open-heart surgery is feasible, but extubation in the intensive care unit after the operation remains common practice at many institutions. The purpose of this study was to evaluate retrospectively the adequacy of our early-extubation strategy and exclusion criteria through analysis based on the Risk Adjustment in Congenital Heart Surgery method (RACHS-1).This retrospective analysis included 359 cases requiring cardiopulmonary bypass (male, 195; female, 164; weight > 3.0 kg; aged 1 month to 18 years). Neonates and preoperatively intubated patients were excluded. Other exclusion criteria included severe preoperative pulmonary hypertension, high-dose catecholamine requirement after cardiopulmonary bypass, delayed sternal closure, laryngomalacia, serious bleeding, and delayed awakening. The early-extubation rates were compared between age groups and RACHS-1 classes.Overall, 83% of cases (298/359) were extubated in the operating room, classified by RACHS-1 categories as follows: 1, 59/59 (100%); 2, 164/200 (84%); 3, 61/78 (78%); and 4-6, 10/22 (45%). The early extubation rate in categories 1-3 (86%, 288/337) was significantly higher than for categories 4-6 (45.5%, 10/22) (P < 0.001). Because they met one of the exclusion criteria, 61 patients (17%) were not extubated in the operating room. Eight patients (2.7%) required re-intubation after early extubation in the operating room, and longer operation time was significantly associated with re-intubation (P < 0.001).Extubation in the operating room after congenital open-heart surgery was feasible based on our criteria, especially for patients in the low RACHS-1 categories, and involves a very low rate of re-intubation.

[Omental Flap for the Device Infection of the HeartMate II].

Case 1:An 18-year-old male underwent emergent left extracorporeal ventricular assist device(eVAD) implantation for a cardiogenic shock because of dilated cardiomyopathy (DCM). After listing for heart transplant, he underwent a HeartMate II implantation as bridge-to-bridge(BTB) therapy. The omental flap was simultaneously used to prevent device infection that could have been induced by the infected malgranulation around the cannulas of the eVAD. Eventually, he was discharged and waiting for transplantation. Case 2:A 30-year-old male with DCM underwent emergent eVAD implantation for left ventricular support, centrifugal veno-pulmonary artery extracorporeal membrane oxygenation (ECMO) for right ventricular and respiratory support, and mitral valve replacement. After weaning of ECMO, he was listed for a heart transplant and underwent a HeartMate II implantation as BTB therapy. However, liver dysfunction and malnutrition prolonged wound healing. Despite applying vacuum assist closure device to promote wound healing, part of the driveline and pump housing were exposed. Therefore, radical debridement and omentopexy were performed for infection control. He was discharged after complete wound healing.

Increased systemic cardiac output improves arterial oxygen saturation in bidirectional cavopulmonary shunt.

The low arterial oxygen saturation (SaO2) after bidirectional cavopulmonary shunt (BCPS) predicts poor prognosis. The venous oxygen saturation of inferior vena cava (SivcO2), as well as the pulmonary blood flow/systemic blood flow ratio (Q p/Q s) affects the SaO2. The purpose of this study is to determine whether SivcO2 or Q p/Q s should be increased to achieve better outcomes after BCPS. Forty-eight patients undergoing BCPS were included. Data of patients' age and body weight, SivcO2, Q p/Q s, pulmonary artery (PA) pressure and resistance, PA area index, morphology of ventricle, atrioventricular valve regurgitation, and history of PA plasty were collected. Stepwise multiple logistic regression analyses were used to investigate which of the factors most affected the SaO2 after BCPS. There was a significant correlation between SivcO2 and SaO2 (r = 0.771, P < 0.00001). There was no strong correlation between Q p/Q s and SaO2 (r = 0.358, P < 0.05). Stepwise multiple logistic regression analyses revealed that both SivcO2 (r = 0.49, 95 % confidence interval (CI) 0.37-0.62, P < 0.0001) and Q p/Q s (r = 11.1, 95 % CI 3.3-18.9, P = 0.007) most affected SaO2 after BCPS. Since the SivcO2 has a stronger correlation than Q p/Q s with SaO2, despite the fact that both raising Q p/Q s and raising cardiac output can increase SaO2, raising cardiac output should be considered prior to Q p/Q s to raise the SaO2 after BCPS.

Clinical efficacy of TEVAR utilizing fenestrated stent-grafts for zone 0 in an elderly frail patient with giant aortic arch aneurysm.

Introduction and importance: Elderly and frail patients with thoracic aortic aneurysms (TAAs) near to origins of cervical arteries present facing challenges with aortic arch replacement with cardiopulmonary bypass, and traditional tube-type stent-grafts are also inadequate for transcatheter endovascular aortic repair (TEVAR). Thus, necessitating precise treatment with fenestrated stent-grafts from zone 0. This approach is crucial for achieving favorable postoperative outcomes without compromising activities of daily living (ADL). Case presentations: An 85-year-old-man admitted to the hospital for treatment of a large TAA. While arch replacement is a definitive procedure, it is highly invasive, and the postoperative ADL are expected to be significantly lower than preoperative levels. Therefore, we performed a debranching TEVAR from Zone 0 with fenestrated stent-graft. The patient was discharged from the hospital on the 11th postoperative day. Clinical discussion: In frail and elderly patients for whom conventional surgery may not be viable, TEVAR emerges as a preferred alternative. However, TEVAR of TAA proximal to the aortic arch continues to pose challenges, necessitating meticulous attention to the cervical branches in the intervention strategy. While surgical intervention in these patients necessitates careful consideration of its suitability, including the potential for postoperative enhancement in ADL, the use of fenestrated stent-grafts from Zone 0 emerges as one of the treatment modalities. Conclusion: The authors present a very elderly case in which fenestrated stent-grafts were used to avoid aortic arch replacement for a large aortic arch aneurysm, resulting in a good postoperative course with no decline in ADL.

Failure of Limb Salvage in a Patient with Chronic Limb-Threatening Ischemia due to Persistent Sciatic Artery Stenosis: Direct Therapeutic Intervention is Important.

A 79-year-old woman presented to our hospital with a complaint of feeling a cold sensation in her right foot. After performing a contrast-enhanced computed tomography angiography, severe stenosis in the right persistent sciatic artery (PSA) was identified. However, stenting was considered inadvisable due to compression issues when sitting. Following anticoagulant therapy, the patient's symptoms improved. However, after seventeen months, she experienced recurrent severe pain in her right foot. Catheter angiography revealed occlusions in both the anterior and posterior tibial arteries. To address the issue, we conducted endovascular therapy, followed by a femoro-popliteal artery bypass and ligation of the PSA. Unfortunately, despite these efforts, a below-knee amputation was eventually performed. Limited experience with the PSA and delayed intervention may have led to the need for amputation. Therefore, it is crucial to emphasize the importance of prompt therapeutic intervention following the onset of initial symptoms.

Nanofiber-coated, tacrolimus-eluting sutures inhibit post-operative neointimal hyperplasia in rats.

Post-operative complications of vascular anastomosis procedures remain a significant clinical challenge and health burden globally. Each year, millions of anastomosis procedures connect arteries and/or veins in vascular bypass, vascular access, organ transplant, and reconstructive surgeries, generally via suturing. Dysfunction of these anastomoses, primarily due to neointimal hyperplasia and the resulting narrowing of the vessel lumen, results in failure rates of up to 50% and billions of dollars in costs to the healthcare system. Non-absorbable sutures are the gold standard for vessel anastomosis; however, damage from the surgical procedure and closure itself causes an inflammatory cascade that leads to neointimal hyperplasia at the anastomosis site. Here, we demonstrate the development of a novel, scalable manufacturing system for fabrication of high strength sutures with nanofiber-based coatings composed of generally regarded as safe (GRAS) polymers and either sirolimus, tacrolimus, everolimus, or pimecrolimus. These sutures provided sufficient tensile strength for maintenance of the vascular anastomosis and sustained drug delivery at the site of the anastomosis. Tacrolimus-eluting sutures provided a significant reduction in neointimal hyperplasia in rats over a period of 14 days with similar vessel endothelialization in comparison to conventional nylon sutures. In contrast, systemically delivered tacrolimus caused significant weight loss and mortality due to toxicity. Thus, drug-eluting sutures provide a promising platform to improve the outcomes of vascular interventions without modifying the clinical workflow and without the risks associated with systemic drug delivery.

Mycotic abdominal aortic aneurysm in a patient with systemic lupus erythematosus: A case of critical antinomy.

Mycotic abdominal aortic aneurysms (MAAAs) are rare but life-threatening, and no standard therapy has yet been established. Effective surgery with intensive antimicrobial therapy is crucial; however, this can be fatal in immunocompromised patients. Only a few reports of MAAA with concomitant autoimmune disease exist; therefore, we were concerned about our lack of experience and knowledge about appropriate treatment. We report a 69-year-old male with an MAAA secondary to septic shock after spinal fusion surgery. He had also been on long-term oral immunosuppressants for systemic lupus erythematosus (SLE). After preoperative cephazolin, we performed debridement of infected tissue, graft replacement with a rifampicin-bonded prosthesis, and omentopexy. On the 52nd post-operative day, he was transferred back to the previous attending hospital under oral antibiotics and prednisolone. MAAA in patients with SLE should be treated with in situ replacement using an antimicrobial prosthetic or biological graft with thorough debridement and omentopexy, followed by antimicrobials and immunosuppressants, as needed.

Near-infrared spectroscopy device selection affects intervention management for cerebral desaturation during cardiopulmonary bypass surgery.

OBJECTIVE: Currently, several near-infrared spectroscopy oximetry devices are used for detecting cerebral ischemia during cardiopulmonary bypass (CPB) surgery. We investigated whether two different models of near-infrared spectroscopy oximetry devices affect the assessment of cerebral ischemia and its management during CPB. METHODS: From January 2017 to August 2017, 70 adult cardiovascular surgery cases were randomly assigned to 1 of 2 different near-infrared spectroscopy oximetry devices. The devices were INVOS 5100C (Medtronic, Minneapolis, MN, USA) (group I; n = 35) and FORE-SIGHT ELITE (CAS Medical Systems, Branford, CT, USA) (group F; n = 35). RESULTS: There were no significant differences in patient characteristics. The rSO2 values were significantly higher for patients in group F than for patients in group I. Scalp-Cortex distance showed negative correlations with the mean rSO2 values in group I (P = 0.01). Interventions for low rSO2 during CPB for groups I and F were increase perfusion flow (13:5; P = 0.03), blood transfusion (7:1; P = 0.02), and both (6:1; P = 0.04), respectively. The Scalp-Cortex distance in group I was significantly longer in patients who required intervention than in patients who did not (17.1 ± 2.5 vs 15.1 ± 1.6 mm; P = 0.007). CONCLUSIONS: It is inappropriate to use the same intervention criteria for different near-infrared spectroscopy oximetry devices. Moreover, brain atrophy influence rSO2 values depending on device selection. It is important to note that inappropriate device selection may misguide perfusionists into performing unnecessary or excessive intervention during CPB.

Extruded poly (glycerol sebacate) and polyglycolic acid vascular graft forms a neoartery.

In the ongoing search for the optimal biomaterial for tissue engineered vascular grafts (TEVGs), poly (glycerol sebacate) (PGS) has emerged as a new potential candidate. We have utilized a novel method to create unique, pore-free, extruded PGS grafts with and without a supportive exterior layer of polyglycolic acid (PGA). The 1 mm diameter by 5 mm length TEVGs were implanted in a rat model of infrarenal abdominal aorta interposition grafting. Three months after implantation, TEVGs comprised of extruded PGS with an external PGA braid demonstrated a patency rate of 9/10 (90%) with no signs of dilatation, dehiscence, or rupture. The PGS/PGA graft was remodeled into a neoartery with complete endothelialization of the neoartery lumen and formation of smooth muscle actinin multilayers as demonstrated via immunohistochemistry. Formation and maturation of extracellular matrix material were also observed, with amounts of elastin and collagen comparable to native rat aorta. No significant host inflammatory response was observed. These findings suggest the combination of an extruded PGS tube with an external reinforcing PGA braid is a promising material for small diameter TEVGs.

Fast-Degrading Tissue-Engineered Vascular Grafts Lead to Increased Extracellular Matrix Cross-Linking Enzyme Expression.

Tissue-engineered vascular grafts (TEVGs) require adequate extracellular matrix (ECM) to withstand arterial pressure. Tissue transglutaminase (TG2) and lysyl oxidase (LOX) are enzymes that cross-link ECM proteins and play a pivotal role in the development of vascular stiffness associated with aging. The purpose of this study is to investigate the expression of ECM cross-linking enzymes and mechanisms of scaffold degeneration leading to vascular stiffness in TEVG remodeling. Fast- and slow-degrading electrospun TEVGs were fabricated using polydioxanone (PDO) and poly(L-lactide-co-caprolactone) (PLCL) copolymer, with a PDO/PLCL ratio of 9:1 for fast-degrading and 1:1 for slow-degrading graft. These grafts were implanted in rats (n = 5/group) as abdominal aortic interposition conduits. The grafts were harvested at 1 month to evaluate patency, mechanical properties, vascular neotissue formation, and the expression of ECM cross-linking enzymes. All TEVGs were patent without any aneurysmal formation at 1 month. ECM area, TG2-positive area, and LOX-positive area were significantly greater in fast-degrading TEVGs compared to slow-degrading TEVGs, with significantly less remaining scaffold. The mechanical properties of fast-degrading TEVGs were similar to that of native aorta, as demonstrated by strain-stress curve. In conclusion, at 1 month, fast-degrading TEVGs had rapid and well-organized ECM with greater TG2 and LOX expression and native-like mechanical properties, compared to slow-degrading TEVGs. Impact statement Around 1.4 million patients in the United States require arterial prostheses each year due to cardiovascular diseases. Current synthetic vascular grafts suffer from increased risk of infection, thrombosis, a lack of endothelialization, and compliance mismatch to the native vasculature. Tissue-engineered vascular graft (TEVGs) presented in this study exhibited tunable biodegradation profiles by controlling the polymer ratio of polydioxanone/poly(L-lactide-co-caprolactone). One month after implantation, the fast-degrading TEVGs exhibited mechanical properties similar to that of native aorta, formation of endothelium, and well-organized extracellular matrix (ECM) with increased expression of tissue transglutaminase and lysyl oxidases, which are critical to the ECM remodeling process.

Aortic atresia with transposition of the great arteries.

We describe a rare case of newborn with aortic atresia and transposition of the great arteries who underwent successful surgical repair. To the best of our knowledge, no such case has been previously reported. We demonstrated that, even with a complex diagnosis, the patient could survive after rapid two-stage Norwood procedure.

Different degradation rates of nanofiber vascular grafts in small and large animal models.

Nanofiber vascular grafts have been shown to create neovessels made of autologous tissue, by in vivo scaffold biodegradation over time. However, many studies on graft materials and biodegradation have been conducted in vitro or in small animal models, instead of large animal models, which demonstrate different degradation profiles. In this study, we compared the degradation profiles of nanofiber vascular grafts in a rat model and a sheep model, while controlling for the type of graft material, the duration of implantation, fabrication method, type of circulation (arterial/venous), and type of surgery (interposition graft). We found that there was significantly less remaining scaffold (i.e., faster degradation) in nanofiber vascular grafts implanted in the sheep model compared with the rat model, in both the arterial and the venous circulations, at 6 months postimplantation. In addition, there was more extracellular matrix deposition, more elastin formation, more mature collagen, and no calcification in the sheep model compared with the rat model. In conclusion, studies comparing degradation of vascular grafts in large and small animal models remain limited. For clinical translation of nanofiber vascular grafts, it is important to understand these differences.