Surgical Management of Cardiac Implantable Electronic Device Complications in Patients Unsuitable for Transvenous Lead Extraction.

BACKGROUND: Although surgical approaches for infected or failing cardiac implantable electronic device (CIED) leads are more invasive than transvenous approaches, they are still required for patients considered unsuitable for transvenous procedures. In this study, surgical management with transvenous equipment for CIED complications was examined in patients unsuitable for transvenous lead extraction.Methods and Results: We retrospectively examined 152 consecutive patients who underwent CIED extraction between April 2009 and December 2021 at the Department of Cardiovascular Surgery, Nippon Medical School. Nine patients (5.9%; mean [±SD] age 61.7±16.7 years) who underwent open heart surgery were identified as unsuitable for the isolated transvenous approach. CIED types included 5 pacemakers and 4 implantable cardioverter-defibrillators; the mean [±SD] lead age was 19.5±7.0 years. Indications for surgical management according to Heart Rhythm Society guidelines included failed prior to transvenous CIED extraction (n=6), intracardiac vegetation (n=2), and severe lead adhesion (n=1). Transvenous CIED extraction tools were used in all patients during or before surgery. Additional surgical procedures with CIED extraction included epicardial lead implantation (n=4) and tricuspid valve repair (n=3). All patients were discharged; during the follow-up period (mean 5.7±3.7 years), only 1 patient died (non-cardiac cause). CONCLUSIONS: Surgical procedures and transvenous extraction tools were combined in the removal strategy for efficacious surgical management of CIED leads. Intensive surgical procedures were safely performed in patients unsuitable for transvenous extraction.

Four-dimensional flow magnetic resonance imaging is useful for assessing hemolytic anemia following surgical repair of type A aortic dissection.

BACKGROUND: Four-dimensional flow magnetic resonance imaging (4D flow MRI) can directly estimate turbulent kinetic energy (TKE) which is associated with pressure loss that are not assessable by other imaging modalities. METHODS AND RESULTS: A 55-year-old woman developed hemolytic anemia after emergency ascending aortic replacement for acute type A aortic dissection. Although computed tomographic angiography or doppler echocardiography could not identify the culprit stenotic legion, 4D flow MRI revealed jet flow and highly elevated TKE at the highly stenosed proximal anastomosis of a replaced ascending aorta. CONCLUSION: Our findings suggest that 4D flow MRI evaluation and TKE estimation enable more accurate and detailed assessment of abnormal flow dynamics than conventional imaging modalities.

Outcomes of abdominal aortic aneurysm repairs: Endovascular vs open surgical repairs.

BACKGROUND: Operative mortality after endovascular aneurysm repair (EVAR) has been reported as lower than open surgical repair (OSR) for abdominal aortic aneurysm (AAA) in randomized controlled trials. However, many cohort studies have demonstrated similar mortality rates for both procedures. We compared operative mortality between EVAR and OSR, at our institution. METHODS: All AAA operations from 2012 to 2017 were reviewed, and baseline characteristics were collected. Outcomes included 30-day mortality, operative data, complications, length of hospital stay (LOS), costs, re-intervention, and survival rates were compared. A multivariable analysis with unbalanced characteristics was performed. RESULTS: We had a total of 162 patients, 100 having OSR and 62 for EVAR. The EVAR group was older, with higher ASA classification. Thirty-day mortality rate did not significantly differ (0/100 for OSR and 2/62 (3%) for EVAR; p = 0.145), while the EVAR group had less blood loss, shorter operative times, and LOS, but higher re-intervention rates (adjusted hazard ratio 6.4 (95%CI: 1.4, 26.8)). Survival rates did not significantly differ between the groups. EVAR cost approximately 1-million yen more. CONCLUSIONS: OSR had low 30-day mortality rate in selected low-risk patients whereas EVAR had less blood loss, shorter operative times, LOS and could be done in high-risk patients with low 30-day mortality but with higher re-intervention rate.

Temporal and Microbiological Analysis of Cardiac Implantable Electrical Device Infections　- A Retrospective Study.

Background: Although the causative pathogens in cardiac implantable electronic device (CIED) infections are well known, the relationship between time after implantation and infection patterns has not been sufficiently investigated. This study investigated the microbiology and onset of CIED infections according to infection patterns. Methods and Results: This retrospective study included 97 patients who underwent CIED removal due to device-related infections between April 2009 and December 2018. After device implantation, infections peaked in the first year and declined gradually over 10 years. Most infections (>60%) occurred within 5 years. Staphylococcal infections, the predominant form of CIED infections, occurred throughout the study period. CIED infections were categorized as systemic (SI; n=26) or local (LI; n=71) infections according to clinical presentation, and as CIED pocket-related (PR; n=85) and non-pocket-related (non-PR; n=12) infections according to the pathogenic pathway. The main causative pathogen in SI was Staphylococcus aureus, whereas coagulase-negative staphylococci were mainly related to LI. Both SI and LI peaked in the first year after implantation and then decreased gradually. There was no significant microbiological difference between PR and non-PR infections. PR infections showed the same temporal distribution as the overall cohort. However, non-PR infections exhibited a uniform temporal distribution after the first year. Conclusions: The severity of CIED infections depends on the causative pathogen, whereas their temporal distribution is affected by the microbiological intrusion pathway.

A Comparison of Outcomes Based on Vessel Type (Native Artery vs. Bypass Graft) and Artery Location (Below-Knee Artery vs. Non-Below-Knee Artery) Using a Combination of Multiple Endovascular Techniques for Acute Lower Limb Ischemia.

BACKGROUND: To evaluate outcomes of endovascular treatment (EVT) using a combination of multiple endovascular techniques for acute lower limb ischemia (ALLI) and to compare outcomes based on vessel type and artery location. METHODS: A total of 95 consecutive patients with ALLI (mean age, 72.0 years; 65 males; 104 lower limbs) who received emergency EVT using a combination of multiple endovascular techniques including thrombolysis, aspiration thrombectomy, stenting, and balloon angioplasty with or without surgical thromboembolectomy, between January 2005 and December 2017 were included. Vessel type was classified into native artery occlusion (native occlusion) and bypass graft occlusion (graft occlusion), including prosthetic and vein graft. Additionally, native arteries were categorized into below-knee occlusion and non-below-knee occlusion. Technical success, perioperative death (POD), ALLI-related death, amputation, amputation-free survival (AFS), and complications were compared according to vessel type (native occlusion vs. graft occlusion) and artery location (below-knee occlusion vs. non-below-knee occlusion). RESULTS: Of all patients with ALLI, 16.8% underwent a single endovascular technique, whereas 83.2% underwent a combination of multiple endovascular techniques. The technicalsuccess, POD, and ALLI-related death rates in the total number of patients were 94.7%, 11.6%, and 4.2%, respectively. A total of 67 patients (75 limbs) and 28 patients (29 limbs) were classified as having native occlusion and graft occlusion (prosthetic, 24 limbs; vein, 5 limbs), respectively. No significant differences in technical success (native occlusion: 92.5% vs. graft occlusion: 100%), POD (14.9% vs. 3.6%), and ALLI-related death (6.0% vs. 0%) were noted between native occlusion and graft occlusion. However, the 30-day AFS rate of native occlusion was significantly lower than that of graft occlusion (75.2% vs. 96.3%, P=0.01). The amputation rate (P=0.03) and AFS rate (P=0.03) of below-knee occlusion were significantly worse for below-knee occlusion patients than for non-below-knee occlusion patients. CONCLUSIONS: EVT using multiple endovascular techniques for ALLI is effective and safe. A combination of multiple endovascular techniques is crucial for successful treatment. However, native occlusion may have a lower AFS rate than graft occlusion, and below-knee occlusion may have a higher risk of amputation than non-below-knee occlusion.

Repetitive aortic dissection in a patient with giant cell arteritis.

Giant cell arteritis is reportedly associated with thoracic aortic aneurysm and acute aortic dissection. We encountered a patient with giant cell arteritis who suffered acute aortic dissection three times within a short period. A pathological specimen of the ascending aorta taken at surgery for type A acute aortic dissection revealed the typical features of giant cell arteritis. Giant cell arteritis patients might be at greater risk of acute aortic dissection than healthy individuals.

A Case of Acute Kidney Injury Associated with Leriche Syndrome.

Leriche syndrome is an aortoiliac occlusive disease with three chief symptoms: claudication, impotence, and weak femoral pulse. It can also cause occlusion of the aorta up to the level of the renal arteries. We report a case in which aortoiliac bypass and renal artery thrombectomy were effective in ameliorating acute kidney injury caused by bilateral renal artery thrombosis.

Computational fluid dynamics simulations of flow distribution and graft designs in apicoaortic bypass.

OBJECTIVE: Apicoaortic bypass has double outlets and its graft design is similar to that of a left ventricular assist device (LVAD). The left ventricular apex to the descending aorta (LV-DsAo) bypass is widely used in apicoaortic bypass. In contrast, the left ventricular apex to the ascending aorta (LV-AsAo) bypass is standard in LVAD surgery. This study aimed to evaluate the graft designs of apicoaortic bypass and their effects on flow distribution and energy loss (EL). METHODS: A simulation study using computational fluid dynamics was performed on the geometry and hemodynamics data obtained from a 30-year-old patient who underwent a LV-DsAo bypass. The ratio of the cardiac output (CO) through the ascending aorta (AsAo) and apicoaortic conduit was set at 50:50, 30:70, and 10:90. Regional blood flow (RBF) and EL were calculated for the different distribution ratios. As an alternative to the LV-DsAo bypass, a virtual LV-AsAo bypass surgery was performed, and each parameter was compared with that of the LV-DsAo bypass. RESULTS: At a distribution ratio of 50:50, the RBF to the head and EL were 16.4% of the total CO and 62.0 mW in the LV-DsAo bypass, and 32.3% and 81.5 mW in the LV-AsAo bypass, respectively. The RBF to the head decreased with the CO through the AsAo in the LV-DsAo bypass, but it was constant in the LV-AsAo bypass. The EL increased inversely with the CO through the AsAo in both graft designs. CONCLUSION: The regional blood flow distribution was different, but the trend of the EL which increased inversely with the CO through the AsAo was similar between the LV-DsAo and LV-AsAo bypasses.

Long-term outcomes of endovascular aortic aneurysm repair with the Zenith AAA endovascular graft: a single-center study.

PURPOSE: To present long-term results obtained with endovascular abdominal aortic aneurysm (AAA) repair (EVAR) using the Zenith AAA endovascular graft from a single institution. MATERIALS AND METHODS: Between 2007 and 2013, 95 consecutive patients (median age 77 years) underwent EVAR using Zenith. Data were prospectively collected and retrospectively analyzed until 2019. Primary outcomes were overall survival, freedom from AAA rupture, and freedom from AAA-related death. Secondary outcomes were freedom from late (> 30 days) re-intervention and surgical conversion, and freedom from aneurysm sac growth (> 5 mm). RESULTS: The initial technical success rate was 96.8%. There were no deaths or intraoperative conversions. Overall survival at 1, 3, 5, and 10 years was 90.8%, 81.7%. 74.3%, and 57.2%, respectively. AAA rupture occurred in one patient (1.1%). Freedom from AAA-related death was 100% during the follow-up period. Freedom from aneurysm sac growth at 1, 3, 5, and 10 years was 98.8%, 86.4%, 76.9%, 53.0%, respectively. Freedom from late re-intervention and open surgical conversion at 1, 3, 5, and 10 years was 98.9%, 88.9%, 86.7, and 57.9%, respectively. CONCLUSION: EVAR with Zenith endografts represents a safe and durable means of AAA repair, and risk of rupture and aneurysm-related death are low.

Surgical procedure for targeting arrhythmogenic substrates in the treatment of ventricular tachycardia associated with cardiac tumors.

BACKGROUND: Complete tumor resection is a standard strategy in the surgical treatment of ventricular tachycardia (VT) associated with cardiac tumors. Recently, an intraoperative electroanatomic mapping system (CARTO) has enabled surgeons to target the localized arrhythmogenic substrate for partial resection and/or cryoablation in nonresectable cardiac tumors. OBJECTIVE: The purpose of this study was to evaluate the surgical procedures and late outcomes of the treatment of VT associated with cardiac tumors. METHODS: We examined six patients (age 1-65 years) who had undergone surgical treatment of VT associated with cardiac tumors between 2010 and 2016. The 4 pathologies of the cardiac tumors were lipoma 2, fibroma 2, hemangioma 1, and lymphoma 1. Intraoperative epicardial mapping using CARTO was performed in 5 patients(80%). Surgical procedures and long-term outcomes were evaluated. RESULTS: Arrhythmogenic substrates with abnormal electrograms, such as fractionated or late potential, were identified locally or circumferentially beside the tumor in every patient. Complete tumor resection with cryoablation was performed in 3 patients. Two patients underwent partial tumor resection with cryoablation. Cryoablation without tumor resection was performed in 1 patient. No mortality and morbidity occurred. Additional catheter ablation was required in 2 patients to treat occurrence of nonclinical VT and induction of clinical VT during hospital stay. Mean follow-up time was 90 ± 52.5 months. There was no recurrence of clinical VT. CONCLUSION: The outcomes of surgical treatment of VT associated with cardiac tumors were excellent. Intraoperative CARTO mapping was beneficial to eliminate the VT substrates associated with nonresectable cardiac tumors.

Enhanced Sternal Healing Through Platelet-Rich Plasma and Biodegradable Gelatin Hydrogel.

Platelet-rich plasma (PRP) contains numerous growth factors and promotes bone fracture healing. The aim of this study was to evaluate the effectiveness of the controlled release of PRP from biodegradable gelatin hydrogel for promoting healing in a rabbit ischemic sternal model. PRP was prepared from the whole blood of a Japanese white rabbit. Sixteen rabbits were randomized into four groups (each n = 4) and all underwent median sternotomy and bilateral internal thoracic artery removal. Before the sternum was closed, the following solutions were applied between the sternum incisions in three of the groups: 30 mg of gelatin hydrogel incorporating 300 µL of phosphate-buffered saline, 300 µL of a solution form of PRP, or 30 mg of gelatin hydrogel incorporating 300 µL of PRP (PRP + Gel). The fourth group acted as a control. Sternal healing was evaluated by histology and microcomputed tomography 7 days after the intervention. The PRP + Gel group showed a significantly higher proportion of fibrosis within the fracture area (an indicator of sternal healing) than the other groups and a significantly higher mean intensity of osteocalcin. These results indicate that the controlled release of PRP from locally applied gelatin hydrogel was markedly effective in enhancing sternal healing in the early postoperative period. This novel therapy could potentially help prevent complications, such as deep sternal wound infection and could result in early postoperative ambulation after median sternotomy.

Regulation of Yes-Associated Protein by Laminar Flow.

BACKGROUND: The cells lining the endothelium of blood vessels are recognized as playing critical roles in vascular health and disease. The mechanisms that regulate endothelial cells (ECs) proliferation and release of mediators remain poorly understood but represent a potential source of disease modulation. Actin-cytoskeleton remodeling and cell shape have been suggested as key regulators of phosphorylation of yes-associated protein (YAP) which controls cellular growth and proliferation. Because different types of flow have been shown to affect cell shape and cytoskeleton differently, we hypothesized that the level of phosphorylated yes-associated protein (pYAP; serine 127) decreases in EC exposed to pulsatile uniform flow or steady laminar flow, whereas exposure to pulsatile disturbed flow causes an increase or no change. METHODS: Human umbilical vein endothelial cells (HUVECs) were exposed to pulsatile uniform flow, pulsatile disturbed flow, or steady laminar flow and analyzed by immunoblotting. RESULTS: Exposure of HUVECs to steady laminar flow caused a significant decrease in the levels of pYAP (69.7 + 2.6%, P < 0.05), whereas total YAP levels remained nearly unchanged. Conversely, exposure to either pulsatile uniform or disturbed flow caused a significant decrease in the levels of both pYAP (63.2 + 10.9% and 69.8 + 11.9%, respectively; P < 0.05) and total YAP (57.1 + 17.8% and 58.4 + 16.3%, respectively; P < 0.05). Addition of MG132, a ubiquitin-proteasome system inhibitor, failed to significantly inhibit the decrease in the levels of total YAP in HUVECs exposed to either pulsatile uniform or disturbed flow. CONCLUSIONS: Flow causes a decrease in pYAP. The observed decrease in total YAP levels with pulsatile flow is due to degradation via a proteasome-independent mechanism. This may be a potential target for intervention for disease states such as atherosclerosis and intimal hyperplasia.

A case of cerebral embolism with a large thrombus in the left atrium, and a recurrence of thrombus in the left atrium after the maze procedure.

A 67-year-old woman developed weakness of the entire left side of the body and disturbance of consciousness, and was admitted to our hospital. She had atrial fibrillation (AF) on arrival at the hospital. Diffusion weighted magnetic resonance imaging showed high intensity area in the right basal ganglia, and magnetic resonance angiography showed occlusion of the right internal carotid artery (ICA). Thrombolytic therapy with intravenous tissue plasminogen activator (IV tPA) was administered 225 minutes after onset, and endovascular procedure also performed. After endovascular therapy, the patient had successful recanalization of the right ICA. Transesophageal echocardiography (TEE) showed a mass in the left atrium. Cardiac surgery for the excision of a left atrial mass and the maze procedure for atrial fibrillation were performed on the 29th hospital day. The mass was pathologically confirmed as thrombus. Follow up TEE after cardiac surgery revealed recurrence of thrombus at the both origin of pulmonary vein in the left atrium. Finally, the thrombus was disappeared at 6-month after onset with taking warfarin. She had no stroke events during the clinical course.

Intraoperative electroanatomic mapping.

PURPOSE: An electroanatomic mapping system using an electromagnetic navigation technology constructs a 3-dimensional structure of the heart with high geometric accuracy of the data that provides a precise localization of the substrates of arrhythmias. The system was tested for the feasibility and efficacy in intraoperative mapping. DESCRIPTION: The strength of the magnetic field is measured by a location sensor with three different frequencies generated by a location pad placed beneath the operating table, and the spatial location of the sensor is determined. By roving the catheter on the heart while the local electrogram is recorded simultaneously, the 3-dimensional figure of the heart is reconstructed and an activation or voltage map is generated. EVALUATION: The system was used in 19 patients with ventricular tachycardia or other arrhythmias. The focus or reentrant circuit of the tachycardia was precisely located and a map-guided procedure was successfully performed in all patients. Cardiopulmonary bypass allowed for the tachycardias to be mapped without any hemodynamic compromise. CONCLUSIONS: Intraoperative mapping using the electroanatomic mapping system enables a precise localization of the tachycardia substrate.

Enhanced vascularization by controlled release of platelet-rich plasma impregnated in biodegradable gelatin hydrogel.

BACKGROUND: Platelet-rich plasma (PRP) contains numerous growth factors that have angiogenic activities. However, the PRP-induced angiogenesis is limited by the short half-life period of growth factors. A new drug delivery system of biodegradable gelatin hydrogel was designed to achieve the controlled release of growth factors in PRP. The purpose of this study is to demonstrate the therapeutic efficacy of slow-release of PRP in the inducing of angiogenesis for critical ischemia. METHODS: The PRP was prepared from the whole blood of inbred rats. Thirty-two rats underwent excision of the left femoral artery and its branches to create critical limb ischemia. The rats were randomized into four groups (n=8 each): no treatment (control), intramuscular injection of platelet-poor plasma (PPP), PRP only, or a combination of PRP and gelatin hydrogel (PRP+Gel). Four weeks after the treatment, angiogenesis was evaluated by laser doppler, microangiogram, and immunohistology. RESULTS: The resultant number of platelets for PRP was higher than that of PPP (p<0.01). The concentrations of vascular endothelial growth factor, transforming growth factor-ß1, and platelet-derived growth factor-BB were significantly higher in PRP animals than in PPP (p<0.01). Although the PRP group improved tissue blood flow (82.7%±6.2%) compared with the control group or PPP group (69.6±12.2 or 72.2±11.8%, p<0.05), the improvement of blood flow in the PRP+Gel group was significantly better (95.1%±8.0%, p<0.05) than in the PRP group. Angiographic score in the PRP+Gel group was significantly higher than that in the control, PPP, and PRP groups (8.6±2.1 versus 3.8±0.8, 3.7±0.6, and 5.6±1.5, respectively; p<0.01). Capillary density also increased immunohistologically in the PRP+Gel group when compared with the control, PPP, and PRP groups (p<0.01). CONCLUSIONS: A controlled release system of PRP was effective in inducing angiogenesis for critical ischemia. The biodegradable gelatin hydrogel incorporating PRP as applicable could possibly be used to treat for patients with ischemic cardiomyopathy.

Intraoperative verification of conduction block in atrial fibrillation surgery.

BACKGROUND: Atrial tachycardia is a troublesome and medically refractory complication after surgery for atrial fibrillation. Incomplete surgical ablation during atrial fibrillation surgery can result in residual conduction over the lesions and postoperative atrial tachycardia. Intraoperative verification of conduction block would detect incomplete ablation lesions and direct repeat ablations to prevent postoperative atrial tachycardia. METHODS: The incidence of postoperative atrial tachycardia was examined in 218 patients who underwent atrial fibrillation surgery between November of 1994 and October of 2007. No conduction block across any ablation lesions was confirmed intraoperatively in the first 128 patients (group C). Isolation of each pulmonary vein was verified by intraoperative pulmonary vein pacing in the following 72 patients (group PV). In the recent 18 consecutive patients, conduction block in the coronary sinus, in addition to pulmonary vein isolation, was confirmed by intraoperative coronary sinus pacing (group PV/CS). Postoperative atrial tachycardia was characterized by electroanatomic mapping. RESULTS: The incidence of postoperative atrial tachycardia in groups C and PV was 7% and 1%, respectively (P = .0985). No patients exhibited any postoperative atrial tachycardia in group PV/CS. The postoperative electroanatomic mapping revealed that the mechanisms of the atrial tachycardia were macro-reentry through incomplete coronary sinus and mitral valve ablation lesions (n = 9), and focal activation in the coronary sinus (n = 1). Intraoperative verification of conduction block directed the repeat ablation lesions to the pulmonary veins. CONCLUSION: The majority of postoperative atrial tachycardia was associated with an incomplete coronary sinus ablation. Intraoperative verification of conduction block may be helpful to prevent the occurrence of postoperative atrial tachycardia.

Experience of thoracoscopic extirpation of intrapulmonary lymphangioma.

We report a 59-year-old woman who underwent thoracoscopic extirpation of the intrapulmonary cystic lymphangioma which was located in the subpleural space of the left upper lobe. A chest X-ray showed a solitary round nodule in the left pulmonary hilum. A computed tomography scan revealed a mass shadow at the interlobar region surrounding the interlobar pulmonary artery. A round nodule was recognized as low signal intensity on T1-weighted images by magnetic resonance imaging. There was biphasic signal intensity on T2-weighted images as well. Radiologically, we diagnosed this lesion as a benign cystic tumor in the lung. Thoracoscopic observation revealed a cystic lesion just beneath the visceral pleura of the upper lobe adjacent to the interlobular pulmonary artery. As this suggested a benign bronchogenic cyst, we performed extirpation of the cyst under thoracoscopy. After this operation, the cyst was diagnosed as an intrapulmonary cystic lymphangioma pathologically.