Endovascular repair and open repair surgery of thoraco-abdominal aortic aneurysms cause drastically different types of spinal cord injury.

Both endovascular repair (EVR) and open repair (OR) surgery of thoraco-abdominal aortic aneurysms cause spinal cord (SC) injury that can lead to paraparesis or paraplegia. It has been assumed that mechanisms responsible for SC damage after EVR are similar to those after OR. This pilot study compared the pathophysiology of SC injury after EVR versus OR using a newly developed EVR dog model. An increasing number of stents similar to those used in patients were inserted in the aorta of three dogs to ensure thoracic or thoracic plus lumbar coverage. The aorta of OR dogs was cross-clamped for 45 min. Behavior assessment demonstrated unique patterns of proprioceptive ataxia and evolving paraparesis in EVR versus irreversible paraplegia in OR. MRI showed posterior signal in lumbar SC after EVR versus central cord edema after OR. Histopathology showed white matter edema in L3-L5 localized to the dorsal column medial lemniscus area associated with loss of myelin basic protein but not neurons after EVR, versus massive neuronal loss in the gray matter in L3-L5 after OR. Metabolome analysis demonstrates a distinctive chemical fingerprint of cellular processes in both interventions. Our results call for the development of new therapeutics tailored to these distinct pathophysiologic findings.

The Effect of Increased Intraocular Pressure During Steep Trendelenburg Positioning in Robotic Prostatectomy and Hysterectomy on Structural and Functional Ocular Parameters.

BACKGROUND: Robotic prostatectomy and robotic hysterectomy require steep Trendelenburg positioning. Many authors documented significant increases in intraocular pressure (IOP) during steep Trendelenburg. However, the long-term biological effect of a significant increase in IOP on the structural and functional ocular system is unknown. This study examines the effect of a significant increase in IOP on the visual acuity, retinal nerve fiber layer thickness (RNFLT), and ganglion cell complex (GCC) thickness in 52 patients without preexisting ocular disease of both genders before and 3 months after their procedures. METHODS: This was a prospective cohort study. The total number of patients included was 56, then 3 females and 1 male case were excluded, totaling 28 robotic hysterectomies and 24 robotic prostatectomies were performed. Patients underwent complete eye examination before the procedure and 3 months after, measuring the main outcome of RNFLT and the secondary outcomes of GCC thickness, foveal threshold (FT), mean deviation (MD), and pattern standard deviation (PSD). These outcomes were analyzed using linear mixed-effects models. On the day of surgery, we examined the IOP after induction of anesthesia, at the end of steep Trendelenburg, and in the recovery room. RESULTS: There were significant differences in IOP values at the end of steep Trendelenburg versus after induction and 45-60 minutes post-awakening (P < .001 for both groups). No difference between IOP 45 and 60 minutes post-awakening and IOP after induction was observed in either group. The highest IOPs occurred at the end of the steep Trendelenburg time point for both groups. The mean duration of steep Trendelenburg in robotic prostatectomy was 184.6 minutes (standard deviation [SD] = 30.8), while the mean duration in robotic hysterectomy was 123.0 minutes (SD = 29.8). All ophthalmologic examinations were normal preoperatively and 3 months postoperatively. The ocular parameters in the retina and optic disk did not differ significantly before surgery and 3 months after. CONCLUSIONS: There is a significant increase in IOP during steep Trendelenburg positioning. There was no significant difference in the ocular parameters examined 3 months after the procedure in this cohort.

Spinal cord injury after thoracic endovascular aortic aneurysm repair.

PURPOSE: Thoracic endovascular aortic aneurysm repair (TEVAR) has become a mainstay of therapy for aneurysms and other disorders of the thoracic aorta. The purpose of this narrative review article is to summarize the current literature on the risk factors for and pathophysiology of spinal cord injury (SCI) following TEVAR, and to discuss various intraoperative monitoring and treatment strategies. SOURCE: The articles considered in this review were identified through PubMed using the following search terms: thoracic aortic aneurysm, TEVAR, paralysis+TEVAR, risk factors+TEVAR, spinal cord ischemia+TEVAR, neuromonitoring+thoracic aortic aneurysm, spinal drain, cerebrospinal fluid drainage, treatment of spinal cord ischemia. PRINCIPAL FINDINGS: Spinal cord injury continues to be a challenging complication after TEVAR. Its incidence after TEVAR is not significantly reduced when compared with open thoracoabdominal aortic aneurysm repair. Nevertheless, compared with open procedures, delayed paralysis/paresis is the predominant presentation of SCI after TEVAR. The pathophysiology of SCI is complex and not fully understood, though the evolving concept of the importance of the spinal cord's collateral blood supply network and its imbalance after TEVAR is emerging as a leading factor in the development of SCI. Cerebrospinal fluid drainage, optimal blood pressure management, and newer surgical techniques are important components of the most up-to-date strategies for spinal cord protection. CONCLUSION: Further experimental and clinical research is needed to aid in the discovery of novel neuroprotective strategies for the protection and treatment of SCI following TEVAR.

Fluoroscopic-Guided Lumbar Spinal Drain Insertion for Thoracic Aortic Aneurysm Surgery.

We retrospectively reviewed the medical records of 11 patients who were referred by anesthesiologists to an interventional neuroradiologist for fluoroscopy-guided lumbar spinal drain insertion for thoracic aortic aneurysm repair between January 2010 and June 2015. Successful drain insertion was achieved in all patients. Three (27.3%) patients developed drain-related complications. Fluoroscopy-guided spinal drain insertion is an alternative to the conventional, nonimage-guided, blind technique used by anesthesiologists when they expect to encounter difficulty with insertion or in cases of failed insertion.

Iatrogenic aortic dissection after minimally invasive aortic valve replacement: a case report.

BACKGROUND: As minimally invasive cardiac and vascular procedures are on the rise, the incidence of iatrogenic acute aortic dissection (IAAD) will increase. Cardiovascular professionals should be aware about the risk factors, means of prevention and best management options for IAAD in the perioperative setting. CASE PRESENTATION: We present the successful clinical management of a complicated case of IAAD after minimally invasive aortic valve replacement. CONCLUSION: High index of suspicion is required for prompt diagnosis of IAAD; collaboration of the whole perioperative team is imperative for management of this catastrophe.