Effect of cerebrospinal fluid drainage pressure in descending and thoracoabdominal aortic repair: a prospective multicenter observational study.

PURPOSE: Cerebrospinal fluid drainage (CSFD) is recommended during open or endovascular thoracic aortic repair. However, the incidence of CSFD complications is still high. Recently, CSF pressure has been kept high to avoid complications, but the efficacy of CSFD at higher pressures has not been confirmed. We hypothesize that CSFD at higher pressures is effective for preventing motor deficits. METHODS: This prospective observational study included 14 hospitals that are members of the Japanese Society of Cardiovascular Anesthesiologists. Patients who underwent thoracic and thoracoabdominal aortic repair were divided into four groups: Group 1, CSF pressure around 10 mmHg; Group 2, CSF pressure around 15 mmHg; Group 3, CSFD initiated when motor evoked potential amplitudes decreased; and Group 4, no CSFD. We assessed the association between the CSFD group and motor deficits using mixed-effects logistic regression with a random intercept for the institution. RESULTS: Of 1072 patients in the study, 84 patients (open surgery, 51; thoracic endovascular aortic repair, 33) had motor deficits at discharge. Groups 1 and 2 were not associated with motor deficits (Group 1, odds ratio (OR): 1.53, 95% confidence interval (95% CI): 0.71-3.29, p = 0.276; Group 2, OR: 1.73, 95% CI: 0.62-4.82) when compared with Group 4. Group 3 was significantly more prone to motor deficits than Group 4 (OR: 2.56, 95% CI: 1.27-5.17, p = 0.009). CONCLUSION: CSFD is not associated with motor deficits in thoracic and thoracoabdominal aortic repair with CSF pressure around 10 or 15 mmHg.

Cerebrospinal fluid drainage to prevent postoperative spinal cord injury in thoracic aortic repair.

BACKGROUND: Cerebrospinal fluid drainage (CSFD) is recommended as a spinal cord protective strategy in open and endovascular thoracic aortic repair. Although small studies support the use of CSFD, systematic reviews have not suggested definite conclusion and a large-scale study is needed. Therefore, we reviewed medical records of patients who had undergone descending and thoracoabdominal aortic repair (both open and endovascular repair) at multiple institutions to assess the association between CSFD and postoperative motor deficits. METHODS: Patients included in this study underwent descending or thoracoabdominal aortic repair between 2000 and 2013 at 12 hospitals belonging to the Japanese Association of Spinal Cord Protection in Aortic Surgery. We conducted a retrospective study to investigate whether motor-evoked potential monitoring is effective in reducing motor deficits in thoracic aortic aneurysm repair. We use the same dataset to examine whether CSFD reduces motor deficits after propensity score matching. RESULTS: We reviewed data from 1214 patients [open surgery, 601 (49.5%); endovascular repair, 613 (50.5%)]. CSFD was performed in 417 patients and not performed in the remaining 797 patients. Postoperative motor deficits were observed in 75 (6.2%) patients at discharge. After propensity score matching (n = 700), mixed-effects logistic regression performed revealed that CSFD is associated with postoperative motor deficits at discharge [adjusted odds ratio (OR), 3.87; 95% confidence interval (CI), 2.30-6.51]. CONCLUSION: CSFD may not be effective for postoperative motor deficits at discharge.

Evaluation of Proteins and Cells that Adsorb to Dialysis Membranes Used in Continuous Hemodiafiltration: Comparison of AN69ST, Polymethylmethacrylate, and Polysulfone Membranes.

OBJECTIVE: In intensive care medicine, continuous renal replacement therapy (CRRT) is important for critically ill patients. Various types of dialysis membranes are currently used in clinical settings, each having unique structures and characteristics. This study aimed to perform a detailed analysis of the characteristics of polysulfone (PS), polymethylmethacrylate (PMMA), and polyacrylonitrile (AN69ST) membranes, and to determine differences in the adsorption of proteins and blood cells by membrane material. METHODS: Subjects were patients undergoing CRRT in the ICU of the Kokura Memorial Hospital. After use, membranes were collected and analyzed. Semi-quantitative analysis of the membrane surface was performed by scanning electron microscopy. We determined the identity of proteins adsorbed to the surface of membranes by TOF/MS analysis, and measured the amount of adsorbed chemical mediators. RESULTS: Electron microscopy revealed that, compared to PS and PMMA membranes, AN69ST membranes had a greater amount of adsorbed activated white blood cells (WBCs). A large amount of platelets was adsorbed to PMMA membranes. In terms of the amount of adsorbed protein, significantly more proteins adsorbed to AN69ST membranes compared to PS and PMMA membranes. Moreover, TOF/MS analysis revealed a difference in the types of adsorbed proteins by membrane. Chemokines were particularly prevalent among adsorbed proteins for all 3 membranes. CONCLUSION: Compared to PS and PMMA membranes, AN69ST membranes had a higher capacity to remove activated WBCs. Moreover, apparent differences were noted in the types of proteins that adsorbed to each type of membrane. These differences in membrane properties may impact clinical outcomes.

Aortic Complex Rupture After Transcatheter Aortic Valve Implantation.

Aortic complex rupture is one of the most critical complications associated with transcatheter aortic valve implantation (TAVI). Its incidence is rare, and its mechanism varies by case; therefore, it is difficult to identify the predictors of complex rupture. Herein, we report a clinical case series of aortic complex rupture. Within our cohort, the frequency of complex rupture was 0.8% (4/497 consecutive patients) with an in-hospital mortality of 0. Among these four patients with complex rupture, two underwent emergent thoracotomy and surgical hemostasis without a heart-lung machine and surgical aortic valve replacement, whereas the other two were conservatively managed. The case overview revealed the following similarities: all the patients were elderly, small women; balloon-expandable valves were used; the annulus area was small with heavily calcified leaflet; and aggressive treatment strategy was used (i.e., oversizing and post-dilatation). In such cases, TAVI should be performed with a careful strategy. Once aortic complex rupture occurs, damage can be minimized through cooperation with an institutional heart team and calm management.

Clinical Impact of Intraventricular Conduction Abnormalities After Transcatheter Aortic Valve Implantation With Balloon-Expandable Valves.

Transcatheter aortic valve implantation (TAVI) often causes intraventricular conduction abnormalities (ICA), particularly left bundle branch block (LBBB) and advanced atrioventricular block, requiring pacemaker implantation (PMI). However, the relation between ICA and clinical outcomes after TAVI with balloon-expandable valves remains unclear, particularly in the Asian population. This retrospective study included all patients who underwent TAVI with balloon-expandable valves from October 2013 to September 2016. We defined ICA as new onset of complete LBBB (CLBBB) or PMI within 2 weeks after TAVI. We divided the patients into 2 groups: those with and without ICA (new-ICA and no-ICA groups) and we assessed 1-year outcome. Two hundred one consecutive patients underwent TAVI using balloon-expandable valves (mean age, 84.8 ± 5.7 years; women, 64%). ICA occurred in 47 patients (23%), 37 patients (18%) developed CLBBB, and 34 patients recovered from CLBBB within 1 year after TAVI. Ten patients (5%) who developed symptomatic bradycardia required PMI within 2 weeks after TAVI. At 30 days after PMI, 7 patients already had a very low ventricular pacing rate, and 6 patients who recovered from bradycardia needed pacing at 1 year. Patients with ICA tended to have high 1-year all-cause mortality, but there was no significant difference between the 2 groups (12% vs 7%, p = 0.15). In conclusion, ICA occurred in 23% of patients after TAVI with balloon-expandable valves, and approximately 90% of them recovered from ICA during the follow-up. There was no significant difference in 1-year all-cause mortality between the new-ICA and no-ICA groups.

Clinical Utility of Intraoperative Motor-Evoked Potential Monitoring to Prevent Postoperative Spinal Cord Injury in Thoracic and Thoracoabdominal Aneurysm Repair: An Audit of the Japanese Association of Spinal Cord Protection in Aortic Surgery Database.

BACKGROUND: Spinal cord ischemic injury is the most devastating sequela of descending and thoracoabdominal aortic surgery. Motor-evoked potentials (MEPs) have been used to intraoperatively assess motor tract function, but it remains unclear whether MEP monitoring can decrease the incidence of postoperative motor deficits. Therefore, we reviewed multicenter medical records of patients who had undergone descending and thoracoabdominal aortic repair (both open surgery and endovascular repair) to assess the association of MEP monitoring with postoperative motor deficits. METHODS: Patients included in the study underwent descending or thoracoabdominal aortic repair at 12 hospitals belonging to the Japanese Association of Spinal Cord Protection in Aortic Surgery between 2000 and 2013. Using multivariable mixed-effects logistic regression analysis, we investigated whether intraoperative MEP monitoring was associated with postoperative motor deficits at discharge after open and endovascular aortic repair. RESULTS: We reviewed data from 1214 patients (open surgery, 601 [49.5%]; endovascular repair, 613 [50.5%]). MEP monitoring was performed in 631 patients and not performed in the remaining 583 patients. Postoperative motor deficits were observed in 75 (6.2%) patients at discharge. Multivariable logistic regression analysis revealed that postoperative motor deficits at discharge did not have a significant association with MEP monitoring (adjusted odds ratio [OR], 1.13; 95% confidence interval [CI], 0.69-1.88; P = .624), but with other factors: history of neural deficits (adjusted OR, 6.08; 95% CI, 3.10-11.91; P < .001), spinal drainage (adjusted OR, 2.14; 95% CI, 1.32-3.47; P = .002), and endovascular procedure (adjusted OR, 0.45; 95% CI, 0.27-0.76; P = .003). The sensitivity and specificity of MEP <25% of control value for motor deficits at discharge were 37.8% (95% CI, 26.5%-49.5%) and 95.5% (95% CI, 94.7%-96.4%), respectively. CONCLUSIONS: MEP monitoring was not significantly associated with motor deficits at discharge.

Early Safety and Efficacy of Transcatheter Aortic Valve Implantation for Asian Nonagenarians (from KMH Registry).

As Japan has one of the most rapidly aging populations in the world, transcatheter aortic valve implantation (TAVI) is likely to be performed in increasing numbers of older people. There is little information on either the efficacy or the safety of TAVI in nonagenarians in Asia.From October 2013 to June 2015, 112 consecutive patients underwent TAVI with Edwards SAPIEN XT valves in our institution. We compared 25 patients aged at least 90 years (mean 91.6 ± 1.7 years) with 87 patients aged under 90 years (mean 82.5 ± 6.0 years) at the time of TAVI. All definitions of clinical endpoints and adverse events were based on the Valve Academic Research Consortium 2 definitions.The median follow-up interval was 561.5 days (the first and third quarters, 405.0 and 735.8 days). Nonagenarians had a higher logistic European System for Cardiac Operative Risk Evaluation (EuroSCORE), Euro II score, and the Society of Thoracic Surgeons predictive risk of mortality (STS) score, and a prevalence of clinical frailty scale ≥ 4. The rate of device success, and the 30-day and 6-month mortalities were not different between patients aged ≥ 90 years and < 90 years (96.0% versus 92.0%, P = 0.68; both 0%, P = 1.00; 4.0% versus 3.5%, P = 0.32, respectively). At six months, clinical efficacy and time-related valve safety were also similar in the two groups (12.5% versus 13.4%, P = 1.00; 4.5% versus 10.3%, P = 0.68, respectively). The cumulative 1-year mortalities were not significantly different between the two groups (8.4% versus 9.4%, P = 0.94, respectively).TAVI can contribute to acceptable clinical results and benefits in a carefully selected group of nonagenarians in Asia.

Continuous PECS II block for postoperative analgesia in patients undergoing transapical transcatheter aortic valve implantation.

It has been reported that PECS II block can alleviate postoperative pain following transapical transcatheter aortic valve implantation (TA-TAVI). However, the effectiveness of continuous PECS II block with catheterization has not yet been reported on the postoperative pain in patients undergoing TA-TAVI. We experienced two cases of TA-TAVI who received PECS II block with catheterization to manage postoperative pain. In the first case, a bolus injection for intraoperative pain and subsequent catheterization were performed before the implantation. However, the patient developed severe pain postoperatively in spite of the continuous block due to displacement of the catheter. In the second case, a bolus injection and the catheterization for the continuous block were performed before and after the implantation, respectively, which provided high-quality pain control. Continuous PECS II block may be useful to control perioperative pain associated with TA-TAVI. The insertion of the catheter after the implantation could be useful to avoid its displacement during the surgery.

Performance comparison of a new automated cuff pressure controller with currently available devices in both basic research and clinical settings.

BACKGROUND: The management of tracheal tube cuff pressure in patients receiving mechanical ventilation is important for the prevention of ventilator-associated pneumonia. Currently, cuff pressure is intermittently monitored with a pressure gauge and adjusted when necessary in a routine practice. However, this method results in wide variations in pressure, and adequate management is difficult due to the spontaneous release of air from the cuff, which reduces cuff pressure. In order to continuously maintain a uniform cuff pressure, we developed a new automated cuff pressure controller and compared its properties with existing devices. METHODS: The effectiveness of the new device was assessed with a model trachea/lung and tracheal tube by measuring cuff pressure while on mechanical ventilation. An electrically powered automatic cuff controller or manual cuff pressure control was used for comparison purposes. The effectiveness of the new device was also examined in patients receiving mechanical ventilation by continuously measuring cuff pressure for a 24-h period. RESULTS: Cuff pressure was uniformly maintained with the new device. Moreover, in the clinical setting, variation in pressure from the set pressure was minimal with both the new device and existing device, relative to the intermittent monitoring method. This suggests that, as with the existing device, uniform cuff pressure management is possible with the new device. CONCLUSIONS: Our results demonstrate the ability of the new cuff pressure controller to manage cuff pressure without the need of a power source, highlighting its potential utility in clinical settings.

[Current status of intraoperative motor evoked potential monitoring: a questionnaire study].

BACKGROUND: Intraoperative motor evoked potential (MEP) monitoring has been used for the purpose of preventing neural complications in surgical treatments. There is little information about the current status of intraoperative MEP monitoring in Japan. METHODS: The survey targeted anesthesia departments mainly of university hospitals throughout the country. RESULTS: Answers were obtained from 60 institutions (a response rate of 68%). Intraoperative MEP has been monitored in 58 institutions. Intraoperative MEP monitoring in 35 institutions did not exceed 50 times per year. Especially during thoracoabdominal aortic aneurysm repair, frequency of MEP monitoring in 51 institutions was limited to 10 times per year. A few anesthesiologists were concerned with evaluation of MEP in craniotomy and spine surgery. In contrast, anesthesiologists in 15 institutions were responsible for evaluation of MEP during thoracoabdominal aortic aneurysm repair. Warning criteria of MEP and therapeutic strategies in case of critical MEP change differed by institution. Fifty four responders expected a guideline for clinical use of intraoperative MEP monitoring. CONCLUSIONS: A clinical practice guideline for intraoperative MEP monitoring based on the information from previous investigations and a planned multicenter clinical study is necessary to enhance its utility.

Evaluation of estimation of physiologic ability and surgical stress to predict in-hospital mortality in cardiac surgery.

PURPOSE: Prediction of postoperative risk in cardiac surgery is important for cardiac surgeons and anesthesiologists. We generated a prediction rule for elective digestive surgery, designated as Estimation of Physiologic Ability and Surgical Stress (E-PASS). This study was undertaken to evaluate the accuracy of E-PASS in predicting postoperative risk in cardiac surgery. METHODS: We retrospectively collected data from patients who underwent elective cardiac surgery at a low-volume center (N = 291) and at a high-volume center (N = 784). Data were collected based on the variables required by E-PASS, the European system for cardiac operative risk evaluation (EuroSCORE), and the Ontario Province Risk Score (OPRS). Calibration and discrimination were assessed by the Hosmer-Lemeshow test and the area under the receiver operating characteristic curve (AUC), respectively. The ratio of observed-to-estimated in-hospital mortality rates (OE ratio) was defined as a measure of quality. RESULTS: In-hospital mortality rates were 7.6% at the low-volume center and 1.3% at the high-volume center, accounting for an overall mortality rate of 3.0%. AUC values to detect in-hospital mortality were 0.88 for E-PASS, 0.77 for EuroSCORE, and 0.71 for OPRS. Hosmer-Lemeshow analysis showed a good calibration in all models (P = 0.81 for E-PASS, P = 0.49 for EuroSCORE, and P = 0.94 for OPRS). OE ratios for the low-volume center were 0.83 for E-PASS, 0.70 for EuroSCORE, and 0.83 for OPRS, whereas those for the high-volume center were 0.26 for E-PASS, 0.14 for EuroSCORE, and 0.27 for OPRS. CONCLUSIONS: E-PASS may accurately predict postoperative risk in cardiac surgery. Because the variables are different between cardiac-specific models and E-PASS, patients' risks can be double-checked by cardiac surgeons using cardiac-specific models and by anesthesiologists using E-PASS.

[Arterial pressure-based cardiac output monitoring: 1. FloTrac sensor and SVV].

FloTrac is a recently introduced semi-invasive arterial pressure-based cardiac output (APCO) monitoring device. The accuracy of a new device is usually evaluated by Bland-Altman method, which shows graphically the mean value of differences between a new method and the reference method (bias), standard deviation of the differences (precision) and limits of agreement or 2 standard deviations. Critchley et al calculated the percentage errors which are two standard deviations divided by mean cardiac output, and proposed that percentage error should be less than 30% as a reliable new method. Cardiac output was measured by FloTrac (APCO) and pulmonary arterial catheter-based thermodilution method (ICO) during off-pump coronary artery bypass and resection of pheochromocytoma, procedures associated with hemodynamically unstable conditions. As algorithm is renewed in a new version of the device, the accuracy of the device is improved; bias, precision and limits of agreement decreased; correlation coefficient increased, and percentage error was assessed to be around 30%. On the other hand, there was a tendency for increased negative bias as cardiac output increased, implying APCO tends to underestimate ICO in high CO ranges. APCO is less invasive and could rapidly respond to fast changes of hemodynamic state. FloTrac is expected to become a reliable cardiac output monitoring device even under hemodynamically unstable conditions. Further improvement of the algorithm is anticipated.

Normothermic cardiopulmonary bypass and cardioplegia reduce inotropic requirements and creatine kinase-MB after coronary artery bypass graft surgery.

PURPOSE: To determine whether normothermic cardiopulmonary bypass (CPB) and cardioplegia preserve myocardial function, reduce inotropic requirements, and reduce markers of myocardial ischemia following coronary artery bypass graft surgery (CABG). METHODS: We retrospectively reviewed the charts of 171 consecutive patients undergoing elective CABG by a single surgeon from April 1994 to December 1995. Hypothermic CPB with intermittent cold cardioplegia was used in 83 patients and normothermic CPB with intermittent warm cardioplegia in 88 patients. Demographic, surgical, hemodynamic, and inotropic requirements and laboratory data were reviewed. RESULTS: The duration of CPB was significantly shorter in the normothermic group (113±27vs 90±21 min;P<0.0001). After CPB the cardiac index was similar between groups, but significantly larger doses of both dopamine and dobutamine were required (8vs 5µg·kg-1·min-1,P<0.0001), and significantly more patients required norepinephrine administration in the hypothermic group (18%vs 6%;P=0.01). Postoperative peak values of creatine kinase MB fraction (CK-MB) were significantly lower in the normothermic group (80±60vs 55±54 IU·I-1;P<0.0001). CONCLUSION: Normothermic CPB and cardioplegia reduce inotropic requirements and CK-MB following CABG.