Intrathecal lactate as a predictor of early- but not late-onset spinal cord injury in thoracoabdominal aneurysmectomy

The anesthesiologist's perspective on emergency aortic surgery: Preoperative optimization, intraoperative management, and postoperative surveillance

The management of emergencies related to the aorta requires a multidisciplinary approach involving various health care professionals. Despite technological advancements in treatment methods, the risks and mortality rates associated with surgery remain high. In the emergency department, definitive diagnosis is usually obtained through computed tomography angiography, and management focuses on controlling blood pressure and treating symptoms to prevent further deterioration. Preoperative resuscitation is the main focus, followed by intraoperative management aimed at stabilizing the patient's hemodynamics, controlling bleeding, and protecting vital organs. After the operation, factors such as organ protection, transfusion management, pain control, and overall patient care must be taken into account. Endovascular techniques are becoming more common in surgical treatment, but they also present new challenges in terms of complications and outcomes. It is recommended that patients with suspected ruptured abdominal aortic aneurysms be transferred to facilities with both open and endovascular treatment options and a track record of successful outcomes to ensure the best patient care and long-term results. To achieve optimal patient outcomes, close collaboration and regular case discussions between health care professionals are necessary, as well as participation in educational programs to promote a culture of teamwork and continuous improvement.

Near-infrared spectroscopy to monitor spinal cord oxygenation in οpen thoraco-abdominal aortic surgery. A case series

Objectives. We adopted the near-infrared spectroscopy (NIRS) technology to monitor the spinal oxygen supply through the paraspinous muscles oxygenation in agreement with the concept of “collateral network” circulation. We retrospectively investigated our database of subjects who underwent thoraco-abdominal aorta open repair assessing for the reliability of this monitoring to predict spinal cord injury. Methods. Consecutive patients who underwent elective thoraco-abdominal aorta open repair between March 2019 and September 2021. In addition to standard monitoring, patients received the monitoring of the paraspinous muscles oxygenation by NIRS. Results. In one patient a significant drop of the mean arterial pressure (49 mmHg) and the spinal-cord perfusion pressure (31 mmHg) occurred after the aortic clamping, with a contemporary lowering of the left-side oxygenation of paraspinous muscles (<40%). Both the blood pressure and the spinal cord perfusion pressure were restored within 10 minutes, but the oxygenation remained at an unsafe level (<55%) until the end of the surgery. This same patient experienced a lower-limb paralysis post-operatively. It did not happen in the other 11 cases of the sample. Conclusions. The main finding of our retrospective analysis indicates reliability of this technology to monitor the spinal cord oxygenation during open thoraco-abdominal aortic surgery and possibly predict spinal cord injury. Still, several questions need to be addressed about the suitability of this technology to the anatomic and pathophysiology of the spinal cord circulation

Spinal Cord Protection of Aorto-Iliac Bypass in Open Repair of Extent II and III Thoracoabdominal Aortic Aneurysm

BACKGROUND

Spinal cord injury (SCI) is one of the serious complications of thoracoabdominal aortic aneurysm (TAAA) repair. Cardiopulmonary bypass (CPB) and left heart bypass (LHB) are well-established extracorporeal circulatory assistance methods to increase distal aortic perfusion and prevent spinal cord ischaemia in TAAA repair. Aorto-iliac bypass, a new surgical adjunct offering distal aortic perfusion without the need of complex perfusion skills, was developed as a substitute for CPB and LHB. However, its spinal cord protective effect is unknown.

METHODS

The perioperative data of 183 patients who had elective open Crawford extent II and III TAAA repair at our aortic centre from July 2011 to May 2019 were retrospectively analysed. Spinal cord protection was compared between the aorto-iliac bypass group (n=106) and the extracorporeal circulatory assistance group (n=77 [65 CPB, 12 LHB]), and the risk factors for SCI in these patients were explored.

RESULTS

Eleven (11) patients had postoperative SCI: five (6.5%) in the extracorporeal circulatory assistance group (four with CPB and one with LHB), and six (5.7%) in the aorto-iliac bypass group. The incidence of SCI was 6.0% (11/183 cases). There was no difference between the aorto-iliac bypass group and the extracorporeal circulatory assistance group (p=1.0), while operation time, proximal aortic clamp time, intercostal artery clamp time, and length of intensive care unit stay were all increased in the latter group. Multivariate logistic regression analysis showed that cerebrospinal fluid pressure (odds ratio [OR], 1.270; 95% confidence interval [CI], 1.092-1.478 [p=0.002]) and lowest haemoglobin on the first postoperative day (OR, 0.610; 95% CI, 0.416-0.895 [p=0.011]) were the independent predictors of SCI in TAAA repair.

CONCLUSIONS

Spinal cord protection of aorto-iliac bypass is comparable to that of CPB and LHB in open TAAA repair.

Effect of sarcopenia on survival and spinal cord deficit outcomes after thoracoabdominal aortic aneurysm repair in patients 60 years of age and older

OBJECTIVE

Sarcopenia (core muscle loss) has been used as a surrogate marker of frailty. We investigated whether sarcopenia would adversely affect survival after thoracoabdominal aortic aneurysm repair.

METHODS

We retrospectively reviewed prospectively collected data from patients aged 60 years or older who underwent thoracoabdominal aortic aneurysm repairs from 2006 to 2016. Imaging was reviewed by 2 radiologists blinded to clinical outcomes. The total psoas index was derived from total psoas muscle cross-sectional area (cm²) at the mid-L4 level, normalized for height (m²). Patients were divided by sex-specific total psoas index values into sarcopenia (lower third) and nonsarcopenia (upper two-thirds) groups. Multivariable modeling identified operative mortality and spinal cord injury predictors. Unadjusted and adjusted survival curves were analyzed.

RESULTS

Of 392 patients identified, those with sarcopenia (n = 131) were older than nonsarcopenic patients (n = 261) (70.0 years vs 68.0 years; P = .02) and more frequently presented with aortic rupture or required urgent/emergency operations. Operative mortality was comparable (sarcopenia 13.7% vs nonsarcopenia 10.0%; P = .3); sarcopenia was not associated with operative mortality in the multivariable model (odds ratio, 1.40; 95% confidence interval, 0.73-2.77; P = .3). Sarcopenic patients experienced more frequent delayed (13.0% vs 4.6%; P = .005) and persistent (10.7% vs 3.4%; P = .008) paraplegia. Sarcopenia independently predicted delayed paraplegia (odds ratio, 3.17; 95% confidence interval, 1.42-7.08; P = .005) and persistent paraplegia (odds ratio, 3.29; 95% confidence interval, 1.33-8.13; P = .01) in the multivariable model. Adjusted for preoperative/operative covariates, midterm survival was similar for sarcopenic and nonsarcopenic patients (P = .3).

CONCLUSIONS

Sarcopenia did not influence early mortality or midterm survival after thoracoabdominal aortic aneurysm repair but was associated with greater risk for delayed and persistent paraplegia.

Near real-time bedside detection of spinal cord ischaemia during aortic repair by microdialysis of the cerebrospinal fluid

OBJECTIVES

Spinal cord ischaemia (SCI) remains the most devastating complication after thoraco-abdominal aortic aneurysm (TAAA) repair. Its early detection is crucial if therapeutic interventions are to be successful. Cerebrospinal fluid (CSF) is readily available and accessible to microdialysis (MD) capable of detecting metabolites involved in SCI [i.e. lactate, pyruvate, the lactate/pyruvate ratio (LPR), glucose and glycerol] in real time. Our aim was to evaluate the feasibility of CSF MD for the real-time detection of SCI metabolites.

METHODS

In a combined experimental and translational approach, CSF MD was evaluated (i) in an established experimental large animal model of SCI with 2 arms: (a) after aortic cross-clamping (AXC, N = 4), simulating open TAAA repair and (b) after total segmental artery sacrifice (Th4-L5, N = 8) simulating thoracic endovascular aortic repair. The CSF was analysed utilizing MD every 15 min. Additionally, CSF was collected hourly from 6 patients undergoing open TAAA repair in a high-volume aortic reference centre and analysed using CSF MD.

RESULTS

In the experimental AXC group, CSF lactate increased 3-fold after 10 min and 10-fold after 60 min of SCI. Analogously, the LPR increased 5-fold by the end of the main AXC period. Average glucose levels demonstrated a 1.5-fold increase at the end of the first (preconditioning) AXC period (0.60±0.14 vs 0.97±0.32 mmol/l); however, they decreased below (to 1/3 of) baseline levels (0.60±0.14 vs 0.19±0.13 mmol/l) by the end of the experiment (after simulated distal arrest). In the experimental segmental artery sacrifice group, lactate levels doubled and the LPR increased 3.3-fold within 30 min and continued to increase steadily almost 5-fold 180 min after total segmental artery sacrifice (P < 0.05). In patients undergoing TAAA repair, lactate similarly increased 5-fold during ischaemia, reaching a maximum at 6 h postoperatively. In 2 patients with intraoperative SCI, indicated by a decrease in the motor evoked potential of >50%, the LPR increased by 200%.

CONCLUSIONS

CSF is widely available during and after TAAA repair, and CSF MD is feasible for detection of early anaerobic metabolites of SCI. CSF MD is a promising new tool combining bedside availability and real-time capacity to potentially enable rapid detection of imminent SCI, thereby maximizing chances to prevent permanent paraplegia in patients with TAAA.

Administration of chlorogenic acid alleviates spinal cord injury via TLR4/NF‑κB and p38 signaling pathway anti‑inflammatory activity

Chlorogenic acid, as a secondary metabolite of plants, exhibits a variety of effects including free radical scavenging, antiseptic, anti‑inflammatory and anti‑viral, in addition to its ability to reduce blood glucose, protect the liver and act as an anti‑hyperlipidemic agent and cholagogue. The present study demonstrated that administration of chlorogenic acid alleviated spinal cord injury (SCI) via anti‑inflammatory activity mediated by nuclear factor (NF)‑κB and p38 signaling pathways. Wistar rats were used to structure a SCI model rat to explore the effects of administration of chlorogenic acid on SCI. The Basso, Beattie and Bresnahan test was executed for assessment of neuronal functional recovery and then spinal cord tissue wet/dry weight ratio was recorded. The present study demonstrated that chlorogenic acid increased SCI‑inhibition of BBB scores and decreased SCI‑induction of spinal cord wet/dry weight ratio in rats. In addition, chlorogenic acid suppressed SCI‑induced inflammatory activity, inducible nitric oxide synthase activity and cyclooxygenase‑2 protein expression in the SCI rat. Furthermore, chlorogenic acid suppressed Toll like receptor (TLR)‑4/myeloid differentiation primary response 88 (MyD88)/NF‑κB/IκB signaling pathways and downregulated p38 mitogen activated protein kinase protein expression in SCI rats. The findings suggest that administration of chlorogenic acid alleviates SCI via anti‑inflammatory activity mediated by TLR4/MyD88/NF‑κB and p38 signaling pathways.