Efficacy and Frequency of Cerebrospinal Fluid Drainage in Operative Management of Thoracoabdominal Aortic Aneurysms

Effect of cerebrospinal fluid drainage pressure in descending and thoracoabdominal aortic repair: a prospective multicenter observational study

PURPOSE

Cerebrospinal fluid drainage (CSFD) is recommended during open or endovascular thoracic aortic repair. However, the incidence of CSFD complications is still high. Recently, CSF pressure has been kept high to avoid complications, but the efficacy of CSFD at higher pressures has not been confirmed. We hypothesize that CSFD at higher pressures is effective for preventing motor deficits.

METHODS

This prospective observational study included 14 hospitals that are members of the Japanese Society of Cardiovascular Anesthesiologists. Patients who underwent thoracic and thoracoabdominal aortic repair were divided into four groups: Group 1, CSF pressure around 10 mmHg; Group 2, CSF pressure around 15 mmHg; Group 3, CSFD initiated when motor evoked potential amplitudes decreased; and Group 4, no CSFD. We assessed the association between the CSFD group and motor deficits using mixed-effects logistic regression with a random intercept for the institution.

RESULTS

Of 1072 patients in the study, 84 patients (open surgery, 51; thoracic endovascular aortic repair, 33) had motor deficits at discharge. Groups 1 and 2 were not associated with motor deficits (Group 1, odds ratio (OR): 1.53, 95% confidence interval (95% CI): 0.71-3.29, p = 0.276; Group 2, OR: 1.73, 95% CI: 0.62-4.82) when compared with Group 4. Group 3 was significantly more prone to motor deficits than Group 4 (OR: 2.56, 95% CI: 1.27-5.17, p = 0.009).

CONCLUSION

CSFD is not associated with motor deficits in thoracic and thoracoabdominal aortic repair with CSF pressure around 10 or 15 mmHg.

Prevention of Oxidative Damage in Spinal Cord Ischemia Upon Aortic Surgery: First-In-Human Results of Shock Wave Therapy Prove Safety and Feasibility

Background Spinal cord ischemia (SCI) remains a devastating complication after aortic dissection or repair. A primary hypoxic damage is followed by a secondary damage resulting in further cellular loss via apoptosis. Affected patients have a poor prognosis and limited therapeutic options. Shock wave therapy (SWT) improves functional outcome, neuronal degeneration and survival in murine spinal cord injury. In this first-in-human study we treated 5 patients with spinal cord ischemia with SWT aiming to prove safety and feasibility. Methods and Results Human neurons were subjected to ischemic injury with subsequent SWT. Reactive oxygen species and cellular apoptosis were quantified using flow cytometry. Signaling of the antioxidative transcription factor NRF2 (nuclear factor erythroid 2-related factor 2) and immune receptor Toll-like receptor 3 (TLR3) were analyzed. To assess whether SWT act via a conserved mechanism, transgenic tlr3^-/- zebrafish created via CRISPR/Cas9 were subjected to spinal cord injury. To translate our findings into a clinical setting, 5 patients with SCI underwent SWT. Baseline analysis and follow-up (6 months) included assessment of American Spinal Cord Injury Association (ASIA) impairment scale, evaluation of Spinal Cord Independence Measure score and World Health Organization Quality of Life questionnaire. SWT reduced the number of reactive oxygen species positive cells and apoptosis upon ischemia via induction of the antioxidative factor nuclear factor erythroid 2-related factor 2. Inhibition or deletion of tlr3 impaired axonal growth after spinal cord lesion in zebrafish, whereas tlr3 stimulation enhanced spinal regeneration. In a first-in-human study, we treated 5 patients with SCI using SWT (mean age, 65.3 years). Four patients presented with acute aortic dissection (80%), 2 of them exhibited preoperative neurological symptoms (40%). Impairment was ASIA A in 1 patient (20%), ASIA B in 3 patients (60%), and ASIA D in 1 patient (20%) at baseline. At follow-up, 2 patients were graded as ASIA A (40%) and 3 patients as ASIA B (60%). Spinal cord independence measure score showed significant improvement. Examination of World Health Organization Quality of Life questionnaires revealed increased scores at follow-up. Conclusions SWT reduces oxidative damage upon SCI via immune receptor TLR3. The first-in-human application proved safety and feasibility in patients with SCI. SWT could therefore become a powerful regenerative treatment option for this devastating injury.

Systematic review of contemporary outcomes of endovascular and open thoracoabdominal aortic aneurysm repair

OBJECTIVE

The purpose of the study was to provide a systematic review of the literature reporting the contemporary early outcomes after endovascular and open repair of thoracoabdominal aortic aneurysms (TAAAs).

METHODS

MEDLINE and Embase were searched for studies from January 2006 to March 2018 that reported either endovascular (using branched or fenestrated endografts) or open repair of TAAA in at least 10 patients. Outcomes of interest included perioperative mortality, spinal cord injury (SCI), renal failure requiring dialysis, and stroke. Pooled proportions were determined using a random-effects model.

RESULTS

The analysis included 71 studies, of which 24 and 47 reported outcomes after endovascular and open TAAA repair, respectively. Endovascular cohort patients were older and had higher rates of coronary artery disease, chronic obstructive pulmonary disease, and diabetes. Endovascular repair was associated with higher rates of SCI (13.5%; 95% confidence interval [CI], 10.5%-16.7%) compared with open repair (7.4%; 95% CI, 6.2%-8.7%; P < .01) but similar rates of permanent paralysis (5.2% [95% CI, 3.8%-6.7%] vs 4.4% [95% CI, 3.3%-5.6%]; P = .39), lower rates of postoperative dialysis (6.4% [95% CI, 3.2%-9.5%] vs 12.0% [95% CI, 8.2%-16.3%]; P = .03) but similar rates of being discharged on permanent dialysis (3.7% [95% CI, 2.0%-5.9%] vs 3.8% [95% CI, 2.9%-5.3%]; P = .93), a trend to lower stroke (2.7% [95% CI, 1.9%-3.6%] vs 3.9% [95% CI, 3.0%-4.9%]; P = .06), and similar perioperative mortality (7.4% [95% CI, 5.9%-9.1%] vs 8.9% [95% CI, 7.2%-10.9%]; P = .21).

CONCLUSIONS

This systematic review summarizes the contemporary literature results of endovascular and open TAAA repair. Endovascular repair studies included patients with more comorbidities and were associated with higher rates of SCI but similar rates of permanent paraplegia, whereas open repair studies had higher rates of postoperative dialysis but similar rates of being discharged on permanent dialysis. Perioperative mortality rates were similar. Universally adopted reporting standards for patient characteristics, outcomes, and the conduct of contemporary comparative studies will allow better assessment and comparisons of the risks associated with the two surgical treatment options for TAAA.

Shock Wave Treatment Protects From Neuronal Degeneration via a Toll-Like Receptor 3 Dependent Mechanism: Implications of a First-Ever Causal Treatment for Ischemic Spinal Cord Injury

Background

Paraplegia following spinal cord ischemia represents a devastating complication of both aortic surgery and endovascular aortic repair. Shock wave treatment was shown to induce angiogenesis and regeneration in ischemic tissue by modulation of early inflammatory response via Toll‐like receptor (TLR) 3 signaling. In preclinical and clinical studies, shock wave treatment had a favorable effect on ischemic myocardium. We hypothesized that shock wave treatment also may have a beneficial effect on spinal cord ischemia.

Methods and Results

A spinal cord ischemia model in mice and spinal slice cultures ex vivo were performed. Treatment groups received immediate shock wave therapy, which resulted in decreased neuronal degeneration and improved motor function. In spinal slice cultures, the activation of TLR3 could be observed. Shock wave effects were abolished in spinal slice cultures from TLR3^−/− mice, whereas the effect was still present in TLR4^−/− mice. TLR4 protein was found to be downregulated parallel to TLR3 signaling. Shock wave–treated animals showed significantly better functional outcome and survival. The protective effect on neurons could be reproduced in human spinal slices.

Conclusions

Shock wave treatment protects from neuronal degeneration via TLR3 signaling and subsequent TLR4 downregulation. Consequently, it represents a promising treatment option for the devastating complication of spinal cord ischemia after aortic repair.

Acute aortic dissection type A

Background

Acute aortic dissection type A (AADA) is a life-threatening vascular emergency. Clinical presentation ranges from pain related to the acute event, collapse due to aortic rupture or pericardial tamponade, or manifestations of organ or limb ischaemia. The purpose of this review was to clarify important clinical issues of AADA management, with a focus on diagnostic and therapeutic challenges.

Methods

Based on a MEDLINE search the latest literature on this topic was reviewed. Results from the German Registry for Acute Aortic Dissection Type A (GERAADA) are also described.

Results

Currently, the perioperative mortality rate of AADA is below 20 per cent, the rate of definitive postoperative neurological impairment approaches 12 per cent and the long-term prognosis after surviving the acute phase of the disease is good. Many pathology- and therapy-associated factors influence the outcome of AADA, including prompt diagnosis with computed tomography and better cerebral protection strategies during aortic arch reconstruction. Endovascular technologies are emerging that may lead to less invasive treatment options.

Conclusion

AADA is an emergency that can present with a wide variety of clinical scenarios. Advances in the surgical management of this complex disease are improving outcomes.

Less-invasive perfusion techniques may improve outcome in thoracoabdominal aortic surgery

OBJECTIVE

The study compared the short-term outcome of distal perfusion in thoracoabdominal aortic aneurysm surgery using a mini-circuit and nonocclusive femoral cannulation with a traditional setup using a roller pump and occlusive cannulation.

METHODS

A total of 120 consecutive patients undergoing thoracoabdominal aortic aneurysm repair with femoro-femoral distal perfusion from 2005 to 2008 were included in this retrospective study. Perfusion was accomplished with either a mini-circuit (centrifugal pump, low priming volume, heparin coating) and nonocclusive femoral cannulation (N = 48, group A) or conventional roller pump and occlusive cannulation (N = 72, group B). Parameters representing tissue damage or ischemia (lactate dehydrogenase, creatine kinase, myoglobin, creatinine, glomerular filtration rate) were monitored intraoperatively and postoperatively and compared.

RESULTS

One patient from each group required renal dialysis postoperatively. Myoglobin values were similar in both groups. Creatine kinase was significantly higher in group B (P < .001). Hemolysis represented from lactate dehydrogenase was higher in group B (P = .005). Both the traditional setup and the mini-circuit achieved a return to preoperative glomerular filtration rate by postoperative day 10 with a significantly higher decrease of glomerular filtration rate within 10 days in group B.

CONCLUSIONS

The use of mini-circuits for thoracoabdominal aortic aneurysm surgery is safe. Compared with patients undergoing suprarenal clamping for abdominal aortic aneurysm, distal and organ perfusion in thoracoabdominal aortic aneurysm surgery maintain renal function independently of the technical setup. An initial decay of glomerular filtration rate on postoperative days 1 to 4, however, seems to be related to intraoperative leg ischemia and hemolysis caused by occlusive cannulation of the femoral vessels and the roller pump. Whether this has an effect on long-term outcome remains to be seen.