Whole body perfusion in patients undergoing frozen elephant trunk for type A acute aortic dissections.

The Frozen Elephant Trunk (FET) can be adopted in selected type A acute aortic dissections (TAAAD). During FET, a prolonged distal circulatory arrest exposes the spine and visceral organs to potential ischemic injuries. Antegrade distal aortic perfusion (ADAP) could minimize this risk: we describe the technical aspects of the simultaneous use of antegrade cerebral perfusion (ACP) and ADAP achieving a "Whole Body Perfusion" (WBP) during FET.

E-vita OPEN NEO in the treatment of acute or chronic aortic pathologies: first interim results of the NEOS study.

OBJECTIVES: The aim of this multicentre study was to demonstrate the safety and clinical performance of E-vita OPEN NEO Stent Graft System (Artivion, Inc.) in the treatment of aneurysm or dissection, both acute and chronic, in the ascending aorta, aortic arch and descending thoracic aorta. METHODS: In this observational study of 12 centres performed in Europe and in Asia patients were enrolled between December 2020 and March 2022. All patients underwent frozen elephant trunk using E-vita OPEN NEO Stent Graft System. Primary end point was the rate of all-cause mortality at 30 days and secondary end points included further clinical and safety data are reported up to 3-6 months postoperatively. RESULTS: A total of 100 patients (66.7% male; mean age, 57.7 years) were enrolled at 12 sites. A total of 99 patients underwent surgery using the E-vita OPEN NEO for acute or subacute type A aortic dissection (n = 37), chronic type A aortic dissection (n = 33) or thoracic aortic aneurysm (n = 29), while 1 patient did not undergo surgery. Device technical success at 24 h was achieved in 97.0%. At discharge, new disabling stroke occurred in 4.4%, while new paraplegia and new paraparesis was reported in 2.2% and 2.2%, respectively. Renal failure requiring permanent (>90 days) dialysis or hemofiltration at discharge was observed in 3.3% of patients. Between discharge and the 3-6 months visit, no patients experienced new disabling stroke, new paraplegia or new paraparesis. The 30-day mortality was 5.1% and the estimated 6-month survival rate was 91.6% (standard deviation: 2.9). CONCLUSIONS: Total arch replacement with the E-vita OPEN NEO can be performed with excellent results in both the acute and chronic setting. This indicates that E-vita OPEN NEO can be used safely, including in the setting of acute type A aortic dissection.

Early outcome of simplified total arch reconstruction under mild hypothermia (30-32 °C) with distal aortic perfusion.

OBJECTIVE: We designed a simplified total arch reconstruction (s-TAR) technique which could be performed under mild hypothermia (30-32 °C) with distal aortic perfusion. This study aimed to compare its efficacy of organ protection with the conventional total arch reconstruction (c-TAR). METHODS: We reviewed the clinical data of 195 patients who had ascending aortic aneurysm with extended aortic arch dilation and underwent simultaneous ascending aorta replacement and TAR procedure between January 2018 and December 2022 in our center. 105 received c-TAR under moderate hypothermia (25-28 °C) with circulatory arrest (c-TAR group); rest 90 received s-TAR under mild hypothermia (30-32 °C) with distal aortic perfusion (s-TAR group). RESULTS: The s-TAR group demonstrated shorter CPB time, cross-clamp time and lower body circulatory arrest time compared with the c-TAR group. The 30-day mortality was 2.9% for the c-TAR group and 1.1% for the s-TAR group (P = 0.043). The mean duration of mechanical ventilation was shorter in the s-TAR group. Paraplegia was observed in 4 of 105 patients (3.8%) in the c-TAR group, while no such events were observed in the s-TAR group. The incidence of temporary neurologic dysfunction was significantly higher in the c-TAR group. The incidence of permanent neurologic dysfunction also showed a tendency to be higher in the c-TAR group, without statistical significance. Furthermore, the incidence of reoperation for bleeding were significantly lower in the s-TAR group. The rate of postoperative hepatic dysfunction and all grades of AKI was remarkably lower in the s-TAR group. The 3-year survival rate was 95.6% in the s-TAR group and 91.4% in the c-TAR group. CONCLUSIONS: s-TAR under mild hypothermia (30-32℃) with distal aortic perfusion is associated with lower mortality and morbidity, offering better neurological and visceral organ protection compared with c-TAR.

Reappraisal of the role of motor and somatosensory evoked potentials during open distal aortic repair.

OBJECTIVE: Intraoperative motor and somatosensory evoked potentials have been applied to monitor spinal cord ischemia during repair. However, their predictive values remain controversial. The purpose of this study was to evaluate the impact of motor evoked potentials and somatosensory evoked potentials on spinal cord ischemia during open distal aortic repair. METHODS: Our group began routine use of both somatosensory evoked potentials and motor evoked potentials at the end of 2004. This study used a historical cohort design, using risk factor and outcome data from our department's prospective registry. Univariate and multivariable statistics for risk-adjusted effects of motor evoked potentials and somatosensory evoked potentials on neurologic outcome and model discrimination were assessed with receiver operating characteristic curves. RESULTS: Both somatosensory evoked potentials and motor evoked potentials were measured in 822 patients undergoing open distal aortic repair between December 2004 and December 2019. Both motor evoked potentials and somatosensory evoked potentials were intact for the duration of surgery in 348 patients (42%). Isolated motor evoked potential loss was observed in 283 patients (34%), isolated somatosensory evoked potential loss was observed in 18 patients (3%), and both motor evoked potential and somatosensory evoked potential loss were observed in 173 patients (21%). No spinal cord ischemia occurred in the 18 cases with isolated somatosensory evoked potential loss. When both signals were lost, signal loss happened in the order of motor evoked potentials and then somatosensory evoked potentials. Immediate spinal cord ischemia occurred in none of those without signal loss, 4 of 283 (1%) with isolated motor evoked potential loss, and 15 of 173 (9%) with motor evoked potential plus somatosensory evoked potential loss. Delayed spinal cord ischemia occurred in 12 of 348 patients (3%) with intact evoked potentials, 24 of 283 patients (8%) with isolated motor evoked potentials loss, and 27 of 173 patients (15%) with motor evoked potentials + somatosensory evoked potentials loss (P < .001). Motor evoked potentials and somatosensory evoked potentials loss were each independently associated with spinal cord ischemia. For immediate spinal cord ischemia, no return of motor evoked potential signals at the conclusion of the surgery had the highest odds ratio of 15.87, with a receiver operating characteristic area under the curve of 0.936, whereas motor evoked potential loss had the highest odds ratio of 3.72 with an area under the curve of 0.638 for delayed spinal cord ischemia. CONCLUSIONS: Somatosensory evoked potentials and motor evoked potentials are both important monitoring measures to predict and prevent spinal cord ischemia during and after open distal aortic repairs. Intraoperative motor evoked potential loss is a risk for immediate and delayed spinal cord ischemia after open distal aortic repair, and somatosensory evoked potential loss further adds predictive value to the motor evoked potential.

Impact of distal aortic perfusion on 'segmental steal' depleting spinal cord blood flow-a quantitative experimental approach.

OBJECTIVES: Aortic steal is an underestimated risk factor for intraoperative spinal cord ischaemia. A negative effect on spinal cord perfusion in thoraco-abdominal aneurysm repair has been suspected if blood drains away from the cord initiated by a reversal of the arterial pressure gradient. The amount of blood and pressure loss via back-bleeding of segmental arteries and the impact of distal aortic perfusion (DaP) have not been analysed yet. The aim of our study was to quantify 'segmental steal' in vivo during simulated thoraco-abdominal aneurysm repair and to determine the impact of DaP on steal and spinal cord perfusion. METHODS: Ten juvenile pigs were put on cardiopulmonary bypass with DaP and visceral arteries were ligated. 'Segmental steal' was quantified by draining against gravity with/without DaP. Blood volume of 'segmental steal' was quantified and microspheres were injected for Post mortem spinal cord perfusion analysis. 'Segmental steal' was quantified with/without DaP-and with stopped DaP. RESULTS: Quantification revealed a significantly higher steal on cardiopulmonary bypass with DaP with a mean difference of 24(11) ml/min. In all spinal cord segments, blood flow was diminished during steal drainage on DaP, compared to 'no steal'. The least perfused region was the low thoracic to upper lumbar segment. CONCLUSIONS: 'Segmental steal' is a relevant threat to spinal cord perfusion-even with the utilization of DaP-diminishing spinal cord perfusion. The blood volume lost by back-bleeding of segmental arteries is not to be underestimated and occlusion of segmental arteries should be considered in thoraco-abdominal aneurysm repair.

Current strategies of spinal cord protection during thoracoabdominal aortic surgery.

Despite improved survival rates after thoracoabdominal aortic aneurysm repairs, paraplegia remains a devastating complication with high incidence, ranging from 3 to 10%. Ischemic insults to the spinal cord are unavoidable during thoracoabdominal aortic aneurysm repairs. There is no single measure that can prevent paraplegia alone. A multimodality approach is required to minimize the ischemic insults during thoracoabdominal aortic aneurysm repairs and postoperative second hit to the spinal cord. Distal aortic perfusion is important to maintain the collateral network perfusion pressure, while cerebrospinal drainage allows to directly maintain the spinal cord perfusion. Reattachment of segmental arteries T8-T12 is encouraged to lower the incidence of both immediate and delayed paraplegia. Systemic arterial pressure should be maintained above 130 mmHg and cerebrospinal drainage should be continued until the second postoperative day, despite intact neurological status. In this article, we describe our current operative techniques and perioperative management in patients undergoing repairs of thoracoabdominal aortic aneurysm. A review of recent updates on spinal protection strategies is also reported.