Propofol Versus Remifentanil Sedation for Transcatheter Aortic Valve Replacement: A Single Academic Center Experience.

OBJECTIVE: Comparison of remifentanil versus propofol for sedation during transcatheter aortic valve replacement (TAVR) procedures to analyze the risk of sedation-related hypoxemia and hypotension. Secondary outcomes included the rate of conversion to general anesthesia, procedure length, rate of intensive care unit (ICU) admission, ICU and hospital lengths of stay, and 30-day mortality. DESIGN: Retrospective cohort study. SETTING: A single tertiary teaching hospital. PARTICIPANTS: Two hundred fifty-nine patients who had propofol or remifentanil sedation for TAVR between March 2017 and March 2020. INTERVENTION: None. MEASUREMENTS AND MAIN RESULTS: There were 130 patients (50.2%) in the propofol cohort and 129 patients (49.8%) in the remifentanil cohort. The primary outcomes were oxygen saturation nadir values and vasopressor infusion use. Remifentanil was associated with a lower oxygen saturation nadir, as compared to propofol (91.3% v . 95.4%, p < 0.001). Risk factors associated with hypoxemia (defined as <92%) were body mass index (p = 0.0004), obstructive sleep apnea (p = 0.004), and remifentanil maintenance (p < 0.001). Vasopressor infusion use was significantly higher with propofol (64.9% v . 8.5%, p < 0.001). Propofol maintenance and angiotensin-converting enzyme inhibitor/angiotensin II receptor-blocker use were the only variables identified as risk factors for vasopressor use (p < 0.001 and p = 0.009). CONCLUSIONS: For patients undergoing TAVR with conscious sedation, remifentanil was associated with more hypoxemia while propofol was associated with a higher rate of vasopressor use.

Abbreviated exposure to cuprizone is sufficient to induce demyelination and oligodendrocyte loss.

Cuprizone intoxication is one of several animal models used to study demyelination and remyelination. Early treatment protocols exposed mice to cuprizone for 6 weeks to induce demyelination; however, more recent reports have varied exposure times from 4 to 5 weeks. The goal of this study was to determine the minimal exposure of cuprizone in C57BL/6 mice that would induce a pathology of robust demyelination and gliosis similar to that described for a 5- or 6-week treatment. We found that an abbreviated insult of only 2 weeks of exposure to cuprizone induced significant demyelination 3 weeks later (5-week time point) but was somewhat variable. Three weeks of exposure to cuprizone produced extensive demyelination by week 5, equivalent to that observed with 5 weeks of exposure. The depletion of mature oligodendrocytes, as well as microglia and astrocyte accumulation, showed trends similar to those with 5-week exposure to cuprizone. Once mature oligodendrocytes are perturbed after a 3-week treatment, the progression to demyelination occurs without requiring further exposure. Furthermore, the early removal of cuprizone did not accelerate remyelination, suggesting that other sequences of events must follow before repair can occur. Thus, a short, "hit and run" CNS insult triggers a cascade of events leading to demyelination 2-3 weeks later.

Association of Time to Surgery After COVID-19 Infection With Risk of Postoperative Cardiovascular Morbidity.

Importance: The time interval between COVID-19 infection and surgery is a potentially modifiable but understudied risk factor for postoperative complications. Objective: To examine the association between time to surgery after COVID-19 diagnosis and the risk of a composite of major postoperative cardiovascular morbidity events within 30 days of surgery. Design, Setting, and Participants: This single-center, retrospective cohort study was conducted among 3997 adult patients (aged ≥18 years) with a previous diagnosis of COVID-19, as documented by a positive polymerase chain reaction test result, who were undergoing surgery from January 1, 2020, to December 6, 2021. Data were obtained through Structured Query Language access of an existing perioperative data warehouse. Statistical analysis was performed March 29, 2022. Exposure: The time interval between COVID-19 diagnosis and surgery. Main Outcomes and Measures: The primary outcome was the composite occurrence of major cardiovascular comorbidity, defined as deep vein thrombosis, pulmonary embolism, cerebrovascular accident, myocardial injury, acute kidney injury, and death within 30 days after surgery, using multivariable logistic regression. Results: A total of 3997 patients (2223 [55.6%]; median age, 51.3 years [IQR, 35.1-64.4 years]; 667 [16.7%] African American or Black; 2990 [74.8%] White; and 340 [8.5%] other race) were included in the study. The median time from COVID-19 diagnosis to surgery was 98 days (IQR, 30-225 days). Major postoperative adverse cardiovascular events were identified in 485 patients (12.1%). Increased time from COVID-19 diagnosis to surgery was associated with a decreased rate of the composite outcome (adjusted odds ratio, 0.99 [per 10 days]; 95% CI, 0.98-1.00; P = .006). This trend persisted for the 1552 patients who had received at least 1 dose of COVID-19 vaccine (adjusted odds ratio, 0.98 [per 10 days]; 95% CI, 0.97-1.00; P = .04). Conclusions and Relevance: This study suggests that increased time from COVID-19 diagnosis to surgery was associated with a decreased odds of experiencing major postoperative cardiovascular morbidity. This information should be used to better inform risk-benefit discussions concerning optimal surgical timing and perioperative outcomes for patients with a history of COVID-19 infection.

Anesthetic Approach to Postpneumonectomy Syndrome.

Postpneumonectomy syndrome is a rare complication in patients who have previously had a pneumonectomy. Over time, the mediastinum may rotate toward the vacant pleural space, which can cause extrinsic airway and esophageal compression. As such, these patients typically present with progressive dyspnea and dysphagia. There is a paucity of reports in the anesthesiology literature regarding the intraoperative anesthetic approach to such rare patients. We present a case of an 18-year-old female found to have postpneumonectomy syndrome requiring thoracotomy with insertion of tissue expanders. Our case report illustrates the complexities involved in the care of these patients with regards to airway management, ventilation concerns, and potential for hemodynamic compromise. This case report underscores the importance of extensive multidisciplinary planning.

A New Window for the Treatment of Posterior Cerebral Artery, Superior Cerebellar Artery, and Basilar Apex Aneurysm: The Expanded Endoscopic Endonasal Approach.

OBJECTIVE: To explore the feasibility of an endoscopic endonasal transclival approach to treat aneurysms arising in the basilar apex, posterior cerebral arteries, and superior cerebellar arteries. STUDY DESIGN: Cadaveric anatomical study. PARTICIPANTS: Fifteen cadaveric specimens. MAIN OUTCOME MEASURES: Degree of surgical exposure of each artery attained, distance from the nasal vestibule to these three arteries, and feasibility of clipping these vessels using standard vascular clip applicators. RESULTS: Both posterior cerebral arteries were exposed, 0.67 cm (standard deviation [SD]: 0.2) on the right side and 0.59 cm (SD: 0.2) on the left side. Both right and left superior cerebral arteries were exposed, 0.6 cm (SD: 0.2) and 0.7 cm (SD: 0.3), respectively. The length of the basilar artery exposed was 2.6 cm (SD: 0.3). The distance from the nasal vestibule to the posterior cerebral artery, superior cerebellar artery, and basilar apex was 10 cm with an SD of ± 0.7, 0.6, and 0.8 cm, respectively. We were able to apply clips on each of these three vessels with a minimal alteration of surrounding normal tissue. CONCLUSION: The endoscopic endonasal transclival approach represents a potentially feasible surgical corridor to treat aneurysms arising from these vessels.

Using the Endoscopic Endonasal Transclival Approach to Access Aneurysms Arising from AICA, PICA, and Vertebral Artery: An Anatomical Study.

Objective To explore the use of the endoscopic endonasal transclival approach (EEA) for clipping anterior inferior cerebellar artery (AICA), posterior inferior cerebellar artery (PICA), and vertebral artery (VA) aneurysms. Design Anatomical study. Participants Fifteen adult cadavers. Main Outcome Measures Length of artery exposed and distance from the nasal ala to the arteries. Results The length of the right and left VA exposed were 1.7 ± 0.6 cm and 1.6 ± 0.6 cm, respectively. The distance to the right VA was 11.1 ± 0.9 cm and to the left was 11.1 ± 0.8 cm. Right and left AICA were exposed for an average length of 1.1 ± 0.3 cm and 0.8 ± 0.3 cm, respectively. The distance to the right AICA was 10.3 ± 0.8 cm and to the left was 10.3 ± 0.8 cm. The right PICA was exposed for a length of 0.5 ± 0.2 cm at a distance of 10.9 ± 0.5 cm. The left PICA was exposed for a length of 0.5 ± 0.2 cm at a distance of 11.1 ± 0.9 cm. Conclusion The EEA can provide direct access to AICA, PICA, and VA, making it a potential alternative to the traditional approaches for the clipping of aneurysms arising from those arteries.

The Expanded Endoscopic Endonasal Approach to Anterior Communicating Artery Aneurysms: A Cadaveric Morphometric Study.

OBJECTIVE: The purpose of this study was to explore the endoscopic endonasal approach to the anterior communicating artery complex. DESIGN: Anatomic, morphometric analysis of human cadaver heads. SUBJECTS: Fifteen latex-injected adult cadaver heads. MAIN OUTCOME MEASURES: The anatomic boundaries of the operative field and the dimensions of exposure of the anterior communicating artery (ACoA) complex were measured and clip placement feasibility was assessed. RESULTS: Exposure of the ACoA and bilateral A1 and A2 segments was accomplished in all 15 cadaver heads. Average length of the exposed ACoA was 3 ± 1 mm, the left A1 was 5 ± 3 mm and right A1 was 5 ± 1 mm, while the A2 segment was 5 ± 2 mm bilaterally. The average distance from the alar floor to the ACoA was 95 mm, while proximal lateral limit measured between the alar floor margins was 36 mm. The distal lateral limit as defined by the distance between the lateral most exposed margins of the chiasm was 19 mm. Clip placement was accomplished for the ACoA and the A1 and A2 segments bilaterally in all specimens. CONCLUSION: The endoscopic, endonasal transtuberculum, transplanum approach is an anatomically feasible alternative to treating select aneurysms of the ACoA complex.