Diagnostic Value of Cholinesterase Activity for the Development of Postoperative Delirium after Cardiac Surgery.

BACKGROUND: Depression of cholinesterase (CHE) activity has been reported to lead to an amplified neuroinflammatory response, which clinically manifests as postoperative delirium (PD). This observational study investigates the association between CHE activity and the development of PD following elective cardiac surgery. METHODS: Patients with preexisting neurologic deficits or carotid artery disease as well as patients undergoing reoperations or procedures under circulatory arrest have been excluded from this study. The Mini-Mental State Examination, the Confusion Assessment Method for the Intensive Care Unit, and the Intensive Care Delirium Screening Checklist were performed at regular intervals. CHE activity was estimated pre- and postoperatively until postoperative day (POD) 5 and at discharge. RESULTS: A total of 107 patients were included. PD was diagnosed in 34 (31.8%) patients, who have been compared with those without PD. Time on ventilator, length of ICU, and hospital stay were longer in patients with PD (p = 0.001, p < 0.001, and p = 0.004, respectively). MMSE scores were lower in patients with PD (p < 0.001; p = 0.015). CHE activity on POD 1 to 4 as well as at discharge were lower in the delirium group (p = 0.041; p = 0.029; p = 0.015; p = 0.035; p = 0.028, respectively). A perioperative drop of CHE activity of more than 50% and a postoperative CHE activity below 4,800 U/L (on POD 0) were independently associated with an increased risk of development of PD (p = 0.038; p = 0.008, respectively). CONCLUSION: In addition to the established functional tests, routine estimation of CHE activity may serve as an additional diagnostic tool allowing for the timely diagnosis and treatment of PD in cardiac surgery patients.

Complex Valve Surgery in Elderly Patients: Increasingly Necessary and Surprisingly Feasible.

OBJECTIVES: The increasing proportion of elderly patients in cardiac surgery poses additional challenges for the clinical management and leads to a higher operative risk due to multiple comorbidities of these patients. We reviewed the outcome of patients who were 75 years and older and underwent complex multiple valve surgery at our institution. METHODS: A retrospective review was performed to identify patients who were 75 years and older and underwent multiple valve surgery between January 2011 and May 2016 at our institution. Patients were assigned to one out of four subgroups: combined aortic and mitral valve surgery (group AM), aortic and tricuspid valve surgery (group AT), mitral and tricuspid valve surgery (group MT), and aortic, mitral, and tricuspid valve surgery (group AMT). RESULTS: A total of 311 patients underwent multiple valve surgery, of whom 119 (38.3%) were 75 years and older (median: 78 [25th-75th quartile: 76-80]). The estimated operative mortality (EuroSCORE II) in the overall cohort was 10.7%. The observed 30-day mortality was 4.2% (7% in group AM, 0% in group AT, 2.2% in group MT, 3.8% in group AMT; p = 0.685). Main complications were reexplorative surgery in 16%, adverse cerebrovascular events in 6.7%, prolonged mechanical ventilation in 10.1%, renal replacement therapy in 15.1%, nosocomial pneumonia in 15.1%, and pacemaker implantation in 18.5%. CONCLUSIONS: This study demonstrates the feasibility of complex multiple valve surgery in elderly patients. The observed perioperative mortality was lower than predicted. However, we observed a substantial rate of adverse events; therefore, careful patient selection is required in this high-risk patient population.

Safety and efficacy of digital chest drainage units compared to conventional chest drainage units in cardiac surgery.

OBJECTIVES: The use of digital chest drainage units (CDUs) has become increasingly common in thoracic surgery due to several advantages. However, in cardiac surgery, its use is still limited in favour of conventional analogue CDUs. In order to investigate the potential benefit of digital CDUs in cardiac surgery, we compared the safety and efficacy of both systems in patients undergoing cardiac surgery at our centre. METHODS: We retrospectively investigated 265 consecutive patients who underwent cardiac surgery at our institution between June 2017 and October 2017. These patients were divided into 2 groups: patients with analogue (A, n = 65) and digital CDUs (D, n = 200). Postoperative outcome was analysed and compared between both groups. In addition, the 'user experience' was evaluated by means of a questionnaire. RESULTS: The median age of the cohort was 70 years (P = 0.167), 25.3% of patients were female (P = 0.414). There were no differences in terms of re-explorative surgery or use of blood products. Nor was there a difference in the overall amount of fluid collected. However, during the first 6 h, more fluid was collected by the digital CDUs. The overall rate of technical failure was 0.4%. We observed a significantly higher rate of clotting in the tubing system of the digital CDUs (P = 0.042). Concerning the user experience, the digital CDUs were associated with a more favourable ease of use on the regular wards (P < 0.001). With regard to the overall user experience, the digital CDUs outperformed the analogue systems (P = 0.002). CONCLUSIONS: Digital CDUs can be safely and effectively applied in patients after cardiac surgery. Due to the improved patient mobility and simplified chest tube management, the use of digital CDUs may be advantageous for patients after cardiac surgery. However, the issue of clotting of the tubing systems should be addressed by further technical improvements.

Design and training effects of a physical reality simulator for minimally invasive mitral valve surgery.

OBJECTIVES: Minimally invasive mitral valve surgery (MIMVS) through an endoscopic right minithoracotomy is a well-established yet complex procedure that has a challenging learning curve. We have developed a simulator for MIMVS and evaluated its short- and long-term training effects. METHODS: Trainees without simulator experience or training in MIMVS were divided into 2 groups (10 students and 10 residents) and participated in a 5-day training course after initial instruction. Each trainee performed a ring annuloplasty. Scores were given by a supervisor who assessed 5 skills. The duration of each procedure was also measured. To evaluate the long-term effect of the training course, trainees performed the same procedure 4 weeks after the last session. RESULTS: Trainees in the resident group were significantly older compared to those in the student group and had a mean surgical experience of 4.4 ± 0.78 years standard error of the mean. All other demographic data were similar. Significant learning curves could be achieved in both groups over the course of 5 days with regard to total skill scores and total duration. However, when we compared the learning curves of both groups, no significant difference could be seen. Long-term performance in both groups was still significantly better compared to that in the first training session. CONCLUSIONS: Training with our simulator provided a significant enhancement of a trainee's performance. This learning effect was achieved in both groups and was still evident 4 weeks later. We strongly recommend our simulator for simulation-based surgical education of cardiac surgeons interested in MIMVS.

Viabahn stent graft compared with prosthetic surgical above-knee bypass in treatment of superficial femoral artery disease: Long-term results of a retrospective analysis.

The prosthetic surgical above-knee bypass (pAKB) is a standard therapy in superficial femoral artery (SFA) occlusive disease in absence of suitable vein. Viabahn graft has been established as a promising alternative. Since limited comparative data are available, we conducted a retrospective study to compare long-term outcomes of these 2 therapies in a real-world setting.Records of 52 patients (60 limbs), who were treated by pAKB (29 limbs) or Viabahn (31 limbs) were reviewed. Patients were followed up by clinical assessment, physical examination, and resting ankle brachial index (ABI) after 3, 6, 12 months and yearly thereafter. Long-term data were available for 97% in the Viabahn and 93% for pAKB after 73 ±â€Š3.7 months (mean ±â€Šstandard error [SE]).Long-term primary and secondary patencies in Viabahn group were 40% and 70%, respectively, after 63 ±â€Š2.8 months (mean ±â€ŠSE). Total lesion length was 19 ±â€Š11.06 cm (mean ±â€ŠSE), graft size was 6 ±â€Š0.72 mm (mean ±â€ŠSE). Hospital stay was 4.8 ±â€Š0.72 days (mean ±â€ŠSE). Limb salvage was achieved in 90%. Patients in the pAKB group showed a total lesion length of 24.39 ±â€Š1.97 cm (mean ±â€ŠSE), graft size was 7 ±â€Š0.99 mm (mean ±â€ŠSE). Long-term analysis after 83 ±â€Š6.8 months (mean ±â€ŠSE) revealed a primary patency of 78% with a secondary patency of 94%. Hospital stay was 10.4 ±â€Š1.27 days (mean ±â€ŠSE). Limb salvage was ensured in 97%. Long-term primary patency was lower for Viabahn (P = .044), secondary patency (P = .245), and leg salvage (P = .389) were not significantly different. However, hospital stay was shorter (P = .0002) for Viabahn.Long-term analysis of Viabahn revealed a significantly lower primary patency, a similar secondary patency, limb salvage, and significantly shorter hospital stay when compared with pAKB. Our data suggest that pAKB is still a valuable option in patients suitable for an open operation. However, Viabahn can be used as a less invasive treatment in high risk patients.