Clampless aortic punch system for making a large-diameter access route without side-biting clamp: a preliminary study Abstract Although thoracic endovascular aneurysm repair (TEVAR) has been getting popularity as a less-invasive procedure, the treatment of thoracic aortic aneurysm with atherosclerotic aortic disease is still challenging. In hybrid TEVAR through the median sternotomy approach, side-biting clamp of the ascending aorta is often necessary for making an access route; however, it could cause embolic complication and aortic dissection. This study aimed to present the results of our preliminary study on the clampless aortic punch system (APS). The swine aorta was used as experimental specimen (diameter 16–20 mm). A 10-mm collagen-impregnated knitted Dacron graft was anastomosed to the aorta, and the APS was inserted into it. After piercing the aorta with the inner fish hook of the APS, the aortic wall was scooped out by an outer round cutter. Three different-angled cutters (0°, 15°, and 30°) were tested three times. The diameter of the punched-out lesion ranged from 6 to 9 mm (median 8 mm). Macroscopically, no major vessel injuries were seen 15° series, whereas minor or major vessel injuries were seen 30° and 0° series, respectively. Histological findings of 15° series confirmed the sharp edge of the stump and abrupt interruption of the elastic fiber without destruction of the normal three-layer structure of the aortic wall. This study suggests that our clampless APS could reduce the risk of stroke and aortic injury in hybrid TEVAR, and an animal study confirming its utility is now under consideration.

Restless legs syndrome effectively treated with constant-pressure predilution online hemodiafiltration Abstract Background We encountered a case of unstable predilution online HDF due to elevated transmembrane pressure (TMP) when performing constant-speed predilution online hemodiafiltration (HDF) as treatment for restless legs syndrome (RLS) in a dialysis patient. We report the effectiveness of incorporating a newly developed constant-pressure predilution online HDF system as a preventive measure against unstable online HDF and frequent adjustment of settings when treating dialysis patients with RLS. Case presentation A 55-year-old man had suffered from RLS and been undergoing constant-speed online HDF with 45 L target predilution and an ABH-21P hemodiafilter. The symptoms of RLS rated 10 on the International Restless Legs Syndrome Rating Scale (IRLS). The α1-microglobulin (α1-MG) removal rate was only 27.8%, so the hemodiafilter was subsequently replaced with a PEPA hemodiafilter. However, episodes of elevated TMP exceeding 250 mmHg occurred frequently after the replacement and were managed by reducing dialysate flow rate. Therefore, we incorporated a constant-pressure predilution online HDF that maintains TMP below 200 mmHg. The amount of replacement was maintained at approximately 43.5 ± 6.98 L and the α1-MG removal rate was 39.5%, with no need to manually reduce the flow rate. The Alb leakage in dialysate waste was 7.9 g. The patient has maintained an IRLS rating of 0 with no RLS symptoms for the past 4 years. Conclusions Using the constant-pressure mode enabled achieved the clinical endpoint, namely, resolution of RLS with no need to manually reduce the flow rate.

Continuous-flow total artificial heart: hemodynamic and pump-related changes associated with posture in a chronic calf model Abstract This study aimed to evaluate the effects of posture (sitting [lying down]/standing) on hemodynamic and pump-related parameters in calves implanted with our institution’s continuous-flow total artificial heart (CFTAH). These parameters were analyzed with posture information in four calves that had achieved the intended 14-, 30-, or 90-day durations of implantation. In each animal, postoperative hourly data gathered throughout the study were used to compare average values with the animal sitting vs. standing. Pump flow became significantly higher in the standing than sitting position at the same pump speed (standing 7.9 ± 0.8, sitting 7.4 ± 1.0 L/min, p = 0.028). Systemic vascular resistance (SVR) and aortic pressure (AoP) were significantly lower in the standing than sitting position (SVR standing 779 ± 145, sitting 929 ± 206 dyne s/cm5, p = 0.027; AoP standing 93 ± 7, sitting 103 ± 7 mm Hg, p < 0.001). No substantial change occurred in pulmonary vascular resistance (PVR) or pulmonary arterial pressure (PAP) with posture (PVR standing 161 ± 39, sitting 164 ± 48 dyne s/cm5, p = 0.639; PAP standing 32 ± 3, sitting 33 ± 4 mm Hg, p = 0.340). Posture affected some hemodynamic and pump-related parameters in calves with CFTAH, with implications for patients with implanted pumps.

Therapeutic hypothermia after global cerebral ischemia due to left ventricular assist device malfunction Abstract Herein we report the case of a patient who suffered from global cerebral ischemia due to pump stoppage of Jarvik2000 Left ventricular assist device (LVAD) for unknown reason and fatal ventricular arrhythmia at home. Cardiopulmonary resuscitation was started by paramedics 6–7 min after the patient fell down. The patient was transferred to our hospital after the restoration of the LVAD function by exchanging external cables. Mild therapeutic hypothermia was induced and body temperature was kept at 33 °C for 24 h. After rewarming, the patient recovered his consciousness without any neurological deficit.

A case of cardiogenic shock due to acute coronary syndrome successfully recovered by percutaneous and paracorporeal left ventricular assist device Abstract We recently experienced a 70-year-old woman with left main trunk-acute coronary syndrome who was initially supported by Impella 5.0 which converted to paracorporeal left ventricular assist device (LVAD) implantation as a bridge to recovery. Optimized guideline-directed medical therapy with cardiac rehabilitation resulted in successful explantation of LVAD and she discharged on foot.

Influence of albumin leakage on glycated albumin in patients with type 2 diabetes undergoing hemodialysis Abstract Glycated albumin (GA) is recommended as a better glycemic indicator than HbA1c in patients undergoing hemodialysis, because the red blood cell lifespan is generally faster than that in normal subjects. However, GA can be also affected by protein loss in urine and hemodialysis fluid. Therefore, in this study, we investigated the effect of albumin leakage induced by hemodialysis on GA. Nine patients undergoing hemodialysis with a large or small amount of albumin leakage were observed for 9 months in a crossover manner. As a result, it was shown that albumin leakage could affect GA, but the effect was practically small considering the prescription of diabetic drugs. The correlations between HbA1c and blood glucose levels and between GA and blood glucose levels were similar in our study. In conclusion, GA was a reliable indicator, even with the change of hemodialysis modality. The influence of albumin leakage induced by hemodialysis on GA was negligible practically. We should recognize that the preferable glycemic indicator in patients undergoing hemodialysis depends on the hemoglobin and albumin metabolism of each patient.

How to implant the Jarvik 2000 post-auricular driveline: evolution to a novel technique Abstract The post-auricular (PA) driveline positioning for percutaneous power delivery is a specific feature of the Jarvik 2000 FlowMaker LVAD. We applied several technical refinements to optimise the PA implant. Here, we present and discuss these modifications. We retrospectively reviewed all patients implanted with Jarvik 2000 at our Institution. Different PA implant techniques were described. A machine learning analysis was performed to evaluate the determinants of driveline infection. From December 2008 to December 2017, 62 patients were implanted with Jarvik 2000, at our Institution. The PA connection was managed through the “question mark-shaped” incision in 24 patients (39%) and with the “C-shaped” in 18 (29%), whereas 10 (16%) cases received the “vertical incision” and 10 (16%) the “orthogonal incision”. The implant technique resulted highly predictive of driveline infection. The rate of driveline infections was numerically lower among cases managed with the last two techniques. After evolving through different implant techniques, we propose and suggest the “orthogonal incision” to maximise the advantages of the Jarvik 2000 post-auricular driveline.

Deployment of stent graft in an excessively higher position above the renal artery induces a flow channel to the aneurysm in chimney endovascular aortic aneurysm repair: an in vitro study Abstract We aimed to investigate the influences of the sealing length above the renal artery (RA) on gutter formation, non-apposed regions between the aortic wall, stent graft (SG), and chimney graft and incidence of flow channel to the aneurysm in chimney endovascular aortic aneurysm repair (Ch-EVAR) using a juxtarenal abdominal aortic aneurysm model. Neck diameter and length of the silicone model were 24 and 4 mm, respectively. In double Ch-EVAR configuration using Advanta V12, 12 combinations were tested three times with two sizes [28.5 (20%-oversize) and 31 (30%-oversize) mm] of Excluder SG, three sealing lengths above the RA (10, 20, and 30 mm), and two deployment positions (anatomical and cross-leg). Gutter area, non-apposed region, and flow channels to the aneurysm were analyzed using micro-computed tomography. Average gutter area and non-apposed region of 30%-oversize SG were significantly smaller than those of 20%-oversize SG (p = 0.05). Furthermore, the non-apposed region of 30%-oversize SG with a 30-mm sealing length was significantly larger than that of the other sealing lengths. For 20%-oversize SGs, flow channel to the aneurysm was observed, except for the anatomical deployment with the sealing length of 10 mm. For 30%-oversize SGs, flow channel was absent, except for the SG with a 30-mm sealing length in both deployment positions. These flow channels were frequently formed through a valley space, existing in the lower unibody above the two limbs. Our data indicated that the optimal sealing length should be chosen in consideration of the device design difference due to the device diameter in Ch-EVAR.

Electrophysiological evaluation of a chronically implanted electrode for suprachoroidal transretinal stimulation in rabbit eyes Abstract In this study, we aimed to determine the electrophysiological efficacy, safety, and electrical stability of a chronically implanted electrode for suprachoroidal transretinal stimulation (STS) in rabbit eyes. A platinum microelectrode was implanted into the scleral pocket of rabbit eyes (n = 5) and followed-up for 6 months. To evaluate the electrophysiological efficacy, electrically evoked potentials (EEPs) were measured every month after implantation. To evaluate safety, fundus examinations, fluorescein angiograms, electroretinograms (ERGs), and visually evoked potentials (VEPs) were measured before and every month after the implantation. At the end of the experiment, histological examination of retinal tissue beneath the site of the electrode was performed. To evaluate electrical stability, the resistance of the circuit was measured every month after implantation. EEPs could be elicited from the STS electrodes at all testing times. The mean threshold current to evoke EEPs was 186.4 ± 47.0 µA at 6 months after implantation. There was no significant change in the threshold over the follow-up period. The resistance of the circuit was significantly increased at 1 months after implantation, with no further increase at 6 months. There was no statistically significant change in the relative amplitudes and implicit times of a- and b-waves of ERGs and VEPs. No intraocular infection, inflammation, or vitreoretinal proliferation was observed in any eye. Histological examination revealed no retinal damage beneath the electrode. We conclude that chronically implanted electrodes for STS appear to be effective, safe, and electrically stable.

A subcostal approach is favorable compared to sternotomy for left ventricular assist device exchange field of research: artificial heart (clinical) Abstract This is a single-center retrospective study to summarize clinical outcomes of patients requiring surgical continuous-flow left ventricular assist device (HeartMate II) exchange. The patients who underwent HeartMate II exchange were divided into two groups either via a subcostal approach (SC group) or a full sternotomy (FS group). The exclusion criteria of a subcostal approach for device exchange included the presence of outflow graft obstruction, and/or the need for concomitant cardiac procedures. Among 277 consecutive patients who underwent HeartMate II implantation from July 2008 to December 2015, 25 patients (9.0%) required device exchange (SC group; N = 13, FS group; N = 12). The SC group, compared to the FS group, had a shorter operative time (200.6 ± 31.4 min vs 534.2 ± 123.9 min; P < 0.001), shorter cardiopulmonary bypass time (33.1 ± 22.0 min vs 151.5 ± 53.1 min; P < 0.001), fewer blood transfusion (0.31 ± 0.48 units vs 4.67 ± 3.65 units; P = 0.002). The SC group had lower incidence of postoperative prolonged intubation (> 24 h) (7.7% vs 90.9%, P < 0.001), tracheostomy (0.0% vs 41.7%, P = 0.015), acute kidney injury requiring dialysis (0.0% vs 33.3%, P = 0.039). In-hospital mortality was 0.0% (0/13) in the SC group and 16.7% (2/12) in the FS group (P = 0.220). In conclusion, a subcostal approach was associated with shorter operative time, fewer blood transfusions, and less postoperative complications, compared to full sternotomy. A subcostal approach, if feasible, is preferred for HeartMate II device exchange.