Anatomical study of the pial arterial network in human spinal cords

Anatomical study of arterial arrangement of the spinal cord in Syrian hamsters (Mesocricetus auratus)

This study aimed to investigate the arterial arrangement of the spinal cord in Syrian hamsters, and to identify differences and similarities to humans and experimental animals that are mostly used as models in studies into ischemic spinal cord injuries. This observational anatomical study was conducted on 20 adult Syrian hamsters using dissection and corrosion casting technique. The general anatomy of the arterial blood supply of spinal cord was obtained and noted as follows: (1) high variability in the level of the origin of right and left vertebral arteries, (2) the independent origin of dorsal intercostal arteries, (3) origin of lumbar arteries as a common trunk with right and left divisions, (4) presence of dorsal and ventral radicular branches in both sides of the cervical spinal cord with almost the same frequency, (5) greater presence of ventral and dorsal radicular branches in the left side of the thoracolumbar spinal cord, (6) two dorsal spinal arteries originating from the posterior inferior cerebellar arteries and extending to the caudal end of the thoracic spinal cord, (7) continuous ventral spinal artery originating from both vertebral arteries and extending to the conus medularis, and (8) presence of the artery of Adamkiewicz in the thoracic region of the spinal cord. From comparative anatomy viewpoints, the arteries supplying the spinal cord of Syrian hamsters exhibit many similarities with humans, laboratory rodents, and rabbits in many aspects compared to dogs, cats, and pigs. Overall, Syrian hamsters can be used as a proposed model in experimental studies of the spinal cord ischemia.

Fenestrated and Branched Stent-Grafts for the Treatment of Thoracoabdominal Aortic Aneurysms: A Systematic Review and Meta-Analysis

Purpose

To investigate the safety and efficacy of total endovascular repair for thoracoabdominal aortic aneurysms (TAAAs) with fenestrated and branched stent-grafts.

Methods

The MEDLINE, EMBASE, and Cochrane databases were searched between January 2001 and December 2021 to identify literature relevant to the use of fenestrated and branched endografts for the treatment of TAAAs. Studies with <4 cases and those on juxtarenal or pararenal aortic aneurysms were excluded. Meta-analyses were conducted to evaluate spinal cord ischemia (SCI), irreversible SCI, renal insufficiency, dialysis, endoleak, reintervention, target vessel patency, 30-day mortality and overall mortality. Fourteen studies comprising 1,114 patients (mean age 72.42 years, 847 men) were selected. The mean TAAA diameter was 67 mm. The Crawford TAAA classification was type I-III in 759 cases, type IV in 344 cases, and type V in 10 cases. Outcomes of the meta-analysis are reported as proportions and 95% confidence intervals (CIs).

Results

The pooled rates for 30-day mortality and overall mortality were 6% and 18%, respectively. The pooled rate for technical success was 94% (95% CI, 93–96%), for SCI was 8% (95% CI, 7–10%), for irreversible SCI was 6% (95% CI, 4–7%), for reversible SCI was 5% (95% CI, 4–6%), for reversible SCI was 2% (95% CI, 2–3%), for renal insufficiency was 7% (95% CI, 5–10%), for dialysis was 3% (95% CI, 2–4%), for target vessel patency was 98% (95% CI, 97–99%), and for reintervention was 15% (95% CI, 9–24%).

Conclusion

Fenestrated and branched endografts for the treatment of TAAAs are safe and effective with acceptable early results. Lifelong regular follow-up and additional prospective studies are necessary to substantiate whether this technique is valid.

Role of the Cervical Anterior Spinal Artery in the Endovascular Treatment of Vascular Diseases: Bystander, Accomplice, Victim, or Friend?

The cervical anterior spinal artery (ASA) is a very important artery arising from the intracranial vertebral artery (VA). It can play different roles in endovascular treatment (EVT) of spinal vascular diseases. The current understanding of these roles is incomplete; therefore, we performed this review. We found that cervical ASA can be involved in many spinal vascular diseases, such as arteriovenous fistula (AVF), arteriovenous malformation (AVM), and aneurysm, and can serve as a collateral channel in proximal VA occlusion. In AVF and AVM, when the cervical ASA is involved, it often plays the role of an accomplice or victim because it acts as the feeder or as a bystander that does not provide blood flow to the AVF and AVM. In cervical ASA aneurysm, the ASA is a victim. During EVT of VA aneurysms or stenoses, the cervical ASA ostia can be covered or occluded, resulting in ASA ischemia. In this situation, the ASA is a victim. In VA occlusion or the subclavian steal phenomenon, the cervical ASA can serve as a collateral channel to provide blood flow to the posterior circulation. In this case, the ASA plays the role of a friend. According to the role of the cervical ASA in spinal vascular diseases, EVT should be determined “case by case.” Most importantly, when EVT is performed to treat these diseases, the cervical ASA axis must be preserved. Therefore, understanding the role of the cervical ASA in spinal vascular diseases is crucial.