Comparison of bubble removal performances of five membrane oxygenators with and without a pre-filter.

When employing minimal invasive extracorporeal circulation (MiECC), the removal of bubbles in the circuit is important to prevent air embolism. We investigated the bubble removal performance of the FHP oxygenator with a pre-filter and compared it with that of four oxygenators, including the Fusion oxygenator, Quadrox oxygenator, Inspire oxygenator, and FX oxygenator. A closed test circuit filled with an aqueous glycerin solution was used. Air injection (10 mL) was performed prior to the oxygenator, and the number and volume of the bubbles were measured at the inlet and outlet of each oxygenator. At the inlet of the five oxygenators, there were no significant differences in the total number of bubbles detected. At the outlet, bubbles were classified into two groups according to the bubble size: ≥100 µm and <100 µm. Tests were performed at pump flow rates of 4 and 5 L/min. For bubbles ≥100 µm, which are considered clinically detrimental, the FHP was the lowest number and volume of bubbles at both pump flow rates compared to the other oxygenators. Regarding the bubbles <100 µm, the number of bubbles was higher in the FHP than those in others; however, the volume of bubbles was significantly lower at 4 L/min and tended to be lower at 5 L/min. The use of the FHP with the pre-filter removed more bubbles ≥100 µm in the circuit than that by the other oxygenators.

Bail-Out Pull-Through Pull-Back Technique for Accidental Coverage of the Left Common Carotid Artery During Thoracic Endovascular Aortic Repair.

PURPOSE: We describe a pull-through pull-back technique to revascularize the left common carotid artery (LCCA) that was unintentionally covered during thoracic endovascular aortic repair (TEVAR). CASE REPORT: A 69-year-old man presented with back pain secondary to acute type B aortic dissection with an intimal tear in the proximal descending aorta. Serial computed tomography (CT) revealed an enlarged descending aorta and proximal progression of the aortic dissection. He underwent left carotid-subclavian artery bypass and TEVAR, 10 days after admission. The Valiant Navion stent graft without a bare stent was deployed proximally; however, the LCCA was unintentionally covered by the stent graft during this procedure. A pull-through form was created between the left axillary and femoral arteries using a 0.035-inch guide wire. The pull-through guide wire was gently pulled, and the greater curvature of the proximal end of the stent graft was displaced distally. Angiography confirmed restoration of antegrade blood flow into the LCCA. The patient's postoperative course was uneventful. Follow-up CT performed 6 months postoperatively confirmed preserved blood flow into the LCCA without endoleak nor stent migration. CONCLUSION: The pull-through pull-back technique is a feasible troubleshooting strategy for accidental coverage of supra-aortic vessels during TEVAR.

A three-dimensional biomodel of type A aortic dissection for endovascular interventions.

Thoracic endovascular aortic repair is widely used for type B aortic dissection. However, there is no favorable stent-graft for type A aortic dissection. A significant limitation for device development is the lack of an experimental model for type A aortic dissection. We developed a novel three-dimensional biomodel of type A aortic dissection for endovascular interventions. Based on Digital Imaging and Communication in Medicine data from the computed tomography image of a patient with a type A aortic dissection, a three-dimensional biomodel with a true lumen, a false lumen, and an entry tear located at the ascending aorta was created using laser stereolithography and subsequent vacuum casting. The biomodel was connected to a pulsatile mock circuit. We conducted four tests: an endurance test for clinical hemodynamics, wire insertion into the biomodel, rapid pacing, and simulation of stent-graft placement. The biomodel successfully simulated clinical hemodynamics; the target blood pressure and cardiac output were achieved. The guidewire crossed both true and false lumens via the entry tear. The pressure and flow dropped upon rapid pacing and recovered after it was stopped. This simulation biomodel detected decreased false luminal flow by stent-graft placement and detected residual leak. The three-dimensional biomodel of type A aortic dissection with a pulsatile mock circuit achieved target clinical hemodynamics, demonstrated feasibility for future use during the simulated endovascular procedure, and evaluated changes in the hemodynamics.

Impact of prosthesis-patient mismatch on late outcomes after bioprosthetic mitral valve replacement for mitral regurgitation.

Negative impact of prosthesis-patient mismatch on long-term survival after valve replacement has been reported. However, the effect of prosthesis-patient mismatch after bioprosthetic mitral valve replacement has not yet been well examined. The purpose of this study was to investigate the effect of prosthesis-patient mismatch on late outcomes after bioprosthetic mitral valve replacement for mitral regurgitation. A total of 181 patients underwent bioprosthetic mitral valve replacement between April 2008 and December 2016. After excluding patients with mitral stenosis and those with incomplete data, 128 patients were included in the study. Postoperative transthoracic echocardiography was performed before discharge for all patients and the effective orifice area of bioprosthetic mitral valve was calculated using the formula: 220/pressure half-time, and the effective orifice area index was calculated by the formula: effective orifice area/body surface area. Prosthesis-patient mismatch was defined as a postoperative effective orifice area index ≤ 1.2 cm2/m2. The characteristics and outcomes were compared between the groups. There were 34 patients (26.6%) with prosthesis-patient mismatch and 94 patients (73.4%) without prosthesis-patient mismatch. There were no significant differences in the in-hospital mortality and morbidities. Multivariable analysis showed that prosthesis-patient mismatch was an independent predictor of late mortality (hazard ratio 3.38; 95% confidence interval 1.69-6.75; p = 0.001) and death from heart failure (hazard ratio 31.03, 95% confidence interval 4.49-214.40, p < 0.001). Prosthesis-patient mismatch at discharge after mitral valve replacement for mitral regurgitation was associated with long-term mortality and death from heart failure.

Fenestrated and covered frozen elephant trunk technique for management of chronic aortic dissection.

BACKGROUND: Reintervention for residual dissection after repaired type A aortic dissection remains challenging. When a frozen elephant trunk (FET) is used, the incidence of distal stent graft-induced new entry (d-SINE) is reportedly high in chronic dissection. AIMS: We report a case of successful redo arch repair using fenestrated and covered FET techniques for chronic residual aortic dissection. METHODS: After the arch was transected proximal to the left subclavian artery (LSCA), and a modified FET prosthesis, in which the distal edge of the FET was covered, was deployed. A fenestration was created in the FET on the LSCA aspect. RESULTS: The postoperative course was uneventful. DISCUSSION: The distal edge of the FET was covered to prevent d-SINE. Creation of a fenestration on the FET eliminates the need to reconstruct the LSCA. CONCLUSION: The fenestrated FET technique simplifies redo arch repair and the covered FET technique can potentially prevent d-SINE.

Reconstruction of the left subclavian artery in arch repair: An end-to-side anastomosis technique.

BACKGROUND: The left subclavian artery (LSCA) is deeply located and difficult to visualize in some cases of total arch replacement. AIMS: We report an end-to-side anastomosis technique that enables safer and easier anatomical reconstruction of the LSCA. MATERIALS AND METHODS: Under Hypothermic circulatory arrest, the origin of the LSCA was ligated and pulled caudally. With clamping the distal LSCA, a graft was anastomosed to the anterior wall of the LSCA and antegrade cerebral perfusion to the LSCA was ensured through the anastomosed graft. Thereafter, distal anastomosis was performed proximal to the LSCA. RESULTS: The postoperative course was uneventful. DISCUSSION: Our reconstruction technique provides excellent exposure of the LSCA by pulling the origin of the LSCA caudally. Hemostasis after reconstruction is feasible, as the anastomosis in the anterior wall of the LSCA is easily visualized. CONCLUSION: The end-to-side anastomosis technique for LSCA reconstruction is a simple alternative in arch repair.

Effects of a frozen elephant trunk on postoperative renal dysfunction in acute type A aortic dissection extending into the renal artery.

BACKGROUND: We investigated the effects of frozen elephant trunk (FET) implantation on clinical outcomes in patients with acute type A aortic dissection (ATAAD) extending into the renal artery (RA). METHODS: Between May 2016 and April 2021, 136 patients underwent surgery for ATAAD at our hospital. Patients who died within 7 days postoperatively and those without preoperative contrast-enhanced computed tomography (CT) data were excluded from the study. The remaining 125 patients were included in this study. A preoperative CT-documented RA abnormality was found in 53 patients. Clinical outcomes, including renal dysfunction and CT findings, were compared between 29 patients with and 24 patients without the FET prosthesis. RESULTS: Among the 53 patients with RA abnormalities, origin of the RA from the false lumen was the most common type of abnormality. The percentage of men and rate of arch repair were higher, and the operation, cardiopulmonary bypass, and lower body hypothermic circulatory arrest times were longer in the FET than in the non-FET group. Early mortality rates were similar between groups. The incidence of postoperative acute kidney injury (AKI) was lower in the FET group (35% vs. 67%, p = 0.028). Multivariable analysis showed that FET implantation was associated with a low incidence of AKI (odds ratio: 0.28, 95% confidence interval: 0.08-0.96; p = 0.043). Among the 125 patients with or without RA abnormalities, no predictor of AKI was identified. CONCLUSION: FET implantation protected against postoperative AKI in patients with ATAAD extension into the RA.

Long-Term Outcomes and Echocardiographic Data After Aortic Valve Replacement With a 17-mm Mechanical Valve.

BACKGROUND: We investigated the long-term clinical and hemodynamic outcomes after aortic valve replacement (AVR) with a 17-mm mechanical valve.Methods and Results:Between January 2005 and December 2011, 80 patients with aortic stenosis underwent AVR with the 17-mm St. Jude Medical Regent prosthetic valve. Echocardiography was performed preoperatively, at discharge, and at follow-up, which was performed at least 2 years postoperatively (median interval, 7.3 years). Prosthesis-patient mismatch (PPM) was defined as an indexed effective orifice area <0.85 cm2/m2at discharge and occurred in 25 patients (31%). The median follow-up period was 8.7 years (100% complete). Overall in-hospital mortality was 2.5% (2 patients) with 27 late deaths (34%). The 5- and 10-year survival rates were 78.7% and 63.0%, respectively. Peripheral arterial disease and concomitant mitral valve repair were independent predictors of late mortality. The 5- and 10-year freedom from major adverse valve-related events (MAVRE) rates were 91.6% and 83.5%, respectively. PPM at discharge did not affect long-term survival, freedom from MAVRE, or freedom from heart failure. Echocardiographic data at follow-up revealed a significant reduction in the mean left ventricular mass index (LVMI). LVMI reduction observed at follow-up was similar between patients with and without PPM. CONCLUSIONS: AVR with the 17-mm mechanical prosthesis had acceptable long-term clinical and hemodynamic outcomes. Significant reduction in LVMI was observed regardless of PPM.

Minimized perfusion circuit for acute type A aortic dissection surgery.

A minimized perfusion circuit (MPC) may reduce transfusion requirement and inflammatory response. Its use, however, has not been standardized for complicated cardiovascular surgery. We assessed outcomes of surgery for acute type A aortic dissection (ATAAD) performed with a MPC under circulatory arrest. The study involved 706 patients treated surgically for ATAAD (by hemiarch repair [n = 571] or total arch repair [n = 135]). Total arch repair was performed using selective antegrade cerebral perfusion. Our MPC, a semi-closed bypass system, incorporating a completely closed circuit and a level-sensing reservoir in the venous circuit, was used. Clinical variables, transfusion volume, and outcomes were investigated in patients who underwent hemiarch repair or total arch repair. The overall incidences of shock, organ ischemia, and coagulopathy (prothrombin time-international normalized ratio >1.5) were 26%, 35%, and 8%, respectively. Mean extracorporeal circulation (ECC) time was 149 minutes for the hemiarch repair group and 241 minutes for the total arch repair group, respectively. No patient required conversion to conventional ECC, and there were no complications related to the use of the MPC. The need for transfusion (98% vs. 91%, P = .017) and median transfusion volume (1970 vs. 1680 mL, P = .002) was increased in the total arch repair group. Neither in-hospital mortality (total arch; 12% vs. hemiarch; 7%, P = .11) nor 10-year survival (74.4% vs. 68.4%, P = .79) differed significantly. Outcomes of surgery for ATAAD performed with the MPC were acceptable. The possibility of transfusion and transfusion volume remains high during such surgery, despite the use of the MPC.

Staged treatments of multiple pseudoaneurysms after total arch replacement.

BACKGROUND: An aortic pseudoaneurysm after cardiovascular surgery can be fatal. METHODS/RESULTS: Here, we describe the staged successful treatments of three pseudoaneurysms in a 77-year-old female patient who underwent total arch replacement and coronary artery bypass grafting 5 years ago. Computed tomography revealed three pseudoaneurysms: in the distal anastomosis of the total arch replacement, in the anastomosis of the left common carotid artery, and in the proximal anastomosis of the saphenous vein graft. Endovascular treatment and surgical repair were performed to treat these three pseudoaneurysms. DISCUSSION: An aortic pseudoaneurysm is a rare complication after cardiac or aortic surgery. Here, we present a case of combined endovascular and surgical repairs of three pseudoaneurysms in one patient.

Enhanced caspase activity contributes to aortic wall remodeling and early aneurysm development in a murine model of Marfan syndrome.

OBJECTIVE: Rupture and dissection of aortic root aneurysms remain the leading causes of death in patients with the Marfan syndrome, a hereditary connective tissue disorder that affects 1 in 5000 individuals worldwide. In the present study, we use a Marfan mouse model (Fbn1(C1039G/+)) to investigate the biological importance of apoptosis during aneurysm development in Marfan syndrome. APPROACH AND RESULTS: Using in vivo single-photon emission computed tomographic-imaging and ex vivo autoradiography for Tc99m-annexin, we discovered increased apoptosis in the Fbn1(C1039G/+) ascending aorta during early aneurysm development peaking at 4 weeks. Immunofluorescence colocalization studies identified smooth muscle cells (SMCs) as the apoptotic cell population. As biological proof of concept that early aortic wall apoptosis plays a role in aneurysm development in Marfan syndrome, Fbn1(C1039G/+) mice were treated daily from 2 to 6 weeks with either (1) a pan-caspase inhibitor, Q-VD-OPh (20 mg/kg), or (2) vehicle control intraperitoneally. Q-VD-OPh treatment led to a significant reduction in aneurysm size and decreased extracellular matrix degradation in the aortic wall compared with control mice. In vitro studies using Fbn1(C1039G/+) ascending SMCs showed that apoptotic SMCs have increased elastolytic potential compared with viable cells, mostly because of caspase activity. Moreover, in vitro (1) cell membrane isolation, (2) immunofluorescence staining, and (3) scanning electron microscopy studies illustrate that caspases are expressed on the exterior cell surface of apoptotic SMCs. CONCLUSIONS: Caspase inhibition attenuates aneurysm development in an Fbn1(C1039G/+) Marfan mouse model. Mechanistically, during apoptosis, caspases are expressed on the cell surface of SMCs and likely contribute to elastin degradation and aneurysm development in Marfan syndrome.

[Total Aortic Arch Replacement by Minimally Invasive Approach in a Patient with Permanent Tracheostomy;Report of a Case].

Standard full median sternotomy for total aortic arch replacement in patients with tracheostomy has higher risks for mediastinitis and graft infection. To avoid surgical site infection, it is necessary to keep a sufficient distance between the tracheostomy and the site of surgical skin incision. We herein report a case of a 74-year-old man with permanent tracheostomy after total laryngectomy, who underwent total aortic arch replacement for an aneurysm. Antero-lateral thoracotomy in the 2nd intercostal space with lower partial sternotomy( ALPS approach) provided an enough distance between the tracheostomy and the surgical field. It also provided a good view for surgical procedure and enabled the standard setup of cardiopulmonary bypass with ascending aortic cannulation, venous drainage from the right atrium and the left ventricular venting through the upper right pulmonary vein. The operation was completed in 345 minutes and the patient was discharged on the 11th postoperative day without any complications.

Ex vivo allograft mitral valve leaflet repair prior to orthotopic heart transplantation.

The shortage of donors has limited the number of heart transplantations. We report a successful ex vivo mitral valve repair of the allograft prior to heart transplantation.

Surgical techniques using an attached patch for large left ventricular pseudoaneurysm after inferior acute myocardial infarction.

We report a case of large left ventricular pseudoaneurysm after inferior acute myocardial infarction. Patch repair is commonly performed; however, only a few studies have described specific surgical techniques for left ventricular pseudoaneurysm repair of the inferior left ventricular wall. As an optimal repair technique for left ventricular pseudoaneurysm of the inferior left ventricular wall is lacking, we believe our technique is safe and effective in repairing this pathology.

Comparison between Zone 2 and Zone 3 distal anastomoses for aortic arch replacement in terms of invasiveness.

OBJECTIVES: Zone 2 anastomosis with total cervical branch reconstruction for acute type A aortic dissection and aortic arch aneurysms became possible after stent-graft introduction. This may be an easier procedure and reduce the risk of recurrent laryngeal nerve palsy. Therefore, this study aimed to compare the outcomes between Zone 2 and Zone 3 distal anastomoses. METHODS: After evaluating the patient data in our institute between April 2016 and April 2022, the patients in whom distal anastomosis was performed at Zone 2 with a stent-graft were defined as the Zone 2 group (n = 70). The patients in whom distal anastomosis was performed at Zone 3 were defined as the Zone 3 group (n = 24). RESULTS: The incidence of new-onset recurrent nerve palsy was one patient (1.4%) in the Zone 2 group and six patients (25.0%) in the Zone 3 group (p < 0.001). The lower body perfusion arrest time was 44.3 ± 9.1 min in the Zone 2 group and 52.9 ± 12.8 min in the Zone 3 group (p = 0.005). There were no significant differences in in-hospital mortality and morbidities. Multivariable analysis showed that only age was an independent predictor of overall mortality. CONCLUSIONS: Performing distal anastomosis at Zone 2 with a frozen elephant trunk or stent-graft reduced the lower body perfusion arrest time and possibly prevented recurrent nerve palsy.

Morphologic prognostic factor for thoracoabdominal aortic dilation after acute type A dissection repair.

OBJECTIVES: Risk factors for late-term aortic dilation after acute type A aortic dissection repair have not been well examined. The goal of this study was to determine the relationship between the abdominal aortic true lumen location and thoraco-abdominal aortic dilation after surgical repair for acute type A aortic dissection. METHODS: Patients who were preoperatively diagnosed with acute type A aortic dissection between April 2014 and July 2022 were included in this study. We evaluated the renal artery-level dissected aortic morphology and classified the study population into 2 groups: the ventral (those with the true lumen located on the ventral side) and the dorsal (other patients not assigned to the ventral group) groups, based on the location of the true lumen. Aortic dilation was defined as thoraco-abdominal aortic expansion ≥5 mm on 1-year postoperative computed tomography images. RESULTS: We examined 49 surgical patients who were assigned to the ventral (n = 22) and dorsal (n = 27) groups. The number of patients with ≥5 mm thoraco-abdominal aortic dilation after the operation was significantly higher in the ventral group than in the dorsal group (90.9% vs 51.9%, P = 0.009). The multivariable logistic regression analysis showed that the ventral type was an independent prognostic factor for thoraco-abdominal aortic dilation after the operation (odds ratio, 6.01; 95% confidence interval, 1.56-23.77; P = 0.009). CONCLUSIONS: The location of the true lumen of the abdominal aorta in acute type A aortic dissection may be a prognostic factor for thoraco-abdominal aortic dilation after surgical repair.

Appropriate sizing of the frozen elephant trunk: How to predict proximal descending aortic diameter prior to dissection?

OBJECTIVE: The predissection aortic diameter is the best reference for determining the size of the frozen elephant trunk in aortic dissection. We aimed to develop a new prediction method to estimate the predissection diameter of proximal descending aorta. Furthermore, we evaluated the accuracy of the estimated predissection proximal descending aortic diameters calculated using 3 prediction methods. METHODS: A total of 39 patients with acute type A aortic dissection who underwent predissection computed tomography were included in derivation sets. We measured the aortic dimensions at 3 levels of the proximal descending aorta: 5, 10, and 15 cm from zone 2. We developed a new prediction method-postdissection aortic diameter divided by 1.13 (AoDNew factor)-and estimated the predissection aortic diameter using the new and previously proposed methods by Rylski (AoDRylski) and Yamauchi (EquationYamauchi). Furthermore, we validated the new prediction method using a validation dataset with 24 patients. RESULTS: The rate of bias ≤2 mm was significantly greater with EquationYamauchi and AoDNew factor than with AoDRylski in the derivation group at each level of the proximal descending aorta (P < .001). In the validation group, the rate of bias ≤2 mm was significantly greater with EquationYamauchi and AoDNew factor than with AoDRylski at 10 cm and 15 cm from zone 2 (10 cm: P = .014, 15 cm: P < .001). CONCLUSIONS: These results suggest that the new prediction method can be used as a simple and accurate estimation method for the predissection aortic diameter at the proximal descending aorta.

Is the threshold for postoperative prosthesis-patient mismatch the same for all prostheses?

PURPOSE: The effective orifice area index (EOAI) is used to define the prosthesis-patient mismatch (PPM) after aortic valve replacement (AVR). However, few studies have so far evaluated whether the cutoff value for PPM varies across prostheses. This study assessed the hemodynamics in patients given a mechanical valve and then re-evaluated the validity of the commonly accepted threshold. METHODS: The subjects included 329 patients that underwent AVR with a St. Jude Medical Regent valve. The transvalvular pressure gradient and EOAI were determined echocardiographically, and the commonly accepted threshold was analyzed in relation to survival. RESULTS: The mechanical valves very often yielded a postoperative transvalvular pressure gradient >10 mmHg, and thus, clinically significant residual pressure, regardless of the EOAI. The slope of the curve describing the relationship between the transvalvular pressure gradient and EOAI was gentler than that reported for bioprosthetic valves, for which the pressure gradient rises sharply at EOAI <0.85 cm(2)/m(2). The commonly defined PPM did not affect the long-term survival or regression of the left ventricular mass index. CONCLUSIONS: The relationship between the transvalvular pressure gradient and the EOAI in patients given a mechanical prosthesis differed from the reference standard. These data suggest the need to reconsider the appropriate cutoff value for PPM in relation to different prostheses.

Association between frailty and long-term outcomes among patients undergoing thoracic aortic surgery via median sternotomy.

OBJECTIVE: Preoperative assessment of frailty is important for predicting postoperative outcomes. This study investigated the association between frailty and late outcomes among patients who underwent thoracic aortic surgery via median sternotomy. METHODS: A total of 1010 patients underwent thoracic aortic surgery via median sternotomy between April 2008 and December 2016. Patients < 65 years of age, those who underwent urgent or emergent surgery, and those with incomplete data were excluded; as such, 374 patients were ultimately included in the present study. Frailty was evaluated using an index comprising history of dementia, body mass index < 18.5 kg/m2, and hypoalbuminemia. A frailty score from 0 to 3 was determined by assigning 1 point for each criterion met. Frailty was defined as a score ≥ 1. Patients were categorized into of 2 groups: frail (n = 52) and non-frail (n = 322). The mean follow-up was 6.1 ± 3.1 years. RESULTS: Overall in-hospital mortality did not differ between the frail and non-frail groups. However, the incidence of re-exploration for bleeding and discharge to a health care facility was higher in the frail group than in the non-frail group. Multivariable analysis revealed that preoperative frailty was an independent predictor of late mortality during follow-up [hazard ratio 3.71 (95% confidence interval 2.16-6.37); P < 0.001]. CONCLUSION: Preoperative frailty was associated with late mortality after thoracic aortic surgery. Assessment of preoperative frailty using a simple frailty index may be useful in the decision-making process for elderly patients.