Impact of Intercostal Artery Reinsertion on Neurological Outcome after Thoracoabdominal Aortic Replacement: A 25-Year Single-Center Experience.

BACKGROUND: Intercostal artery reinsertion (ICAR) during thoracoabdominal aortic replacement remains controversial. While some groups recommend the reinsertion of as many arteries as possible, others consider the sacrifice of multiple intercostals practicable. This study investigates the impact of intercostal artery reinsertion or sacrifice on neurological outcomes and long-term survival after thoracoabdominal aortic repair. METHODS: A total of 349 consecutive patients undergoing thoracoabdominal aortic replacement at our institution between 1996 and 2021 were analyzed in a retrospective single-center study. ICAR was performed in 213 patients, while all intercostal arteries were ligated and sacrificed in the remaining cases. The neurological outcome was analyzed regarding temporary and permanent paraplegia or paraparesis. RESULTS: No statistically significant differences were observed between the ICAR and non ICAR groups regarding the cumulative endpoint of transient and permanent spinal cord-related complications (12.2% vs. 11.8%, p = 0.9). Operation, bypass, and cross-clamp times were significantly longer in the ICAR group. Likewise, prolonged mechanical ventilation was more often necessary in the ICAR group (26.4% vs. 16.9%, p = 0.03). Overall long-term survival was similar in both groups in the Kaplan-Meier analysis. CONCLUSION: Omitting ICAR during thoracoabdominal aortic replacement may reduce operation and cross-clamp times and thus minimize the duration of intraoperative spinal cord hypoperfusion.

Simultaneous upper and lower body perfusion using hypothermia during thoracoabdominal aortic surgery.

BACKGROUND: In open thoracoabdominal aortic aneurysm (TAAA) repair, we have been performing vascular reconstruction under moderate to deep hypothermia and assisted circulation using simultaneous upper and lower body perfusion. This method is effective for protecting the spinal cord and the brain, heart, and abdominal organs and for avoiding lung damage. METHODS: TAAA repair was performed under hypothermia at 20-28 °C in 18 cases (Crawford type I in 0 cases, type II in 5, type III in 3, type IV in 4, and Safi V in 6) between October 2014 and January 2023. Cardiopulmonary bypass was conducted by combined upper and lower body perfusion, with perfusion both via the femoral artery and either transapically or via the descending aorta or the left brachial artery. RESULTS: The ischemic time for the artery of Adamkiewicz and the main segmental arteries was 40-124 min (75 ± 33 min). No spinal cord ischemic injury or brain or heart complications occurred. One patient with postoperative right renal artery occlusion and one with an infected aneurysm required tracheostomy, but the intubation time for the other 16 was 32 ± 33 h. The duration of postoperative intensive care unit stay was 6.5 ± 6.2 days, the length of hospital stay was 29 ± 15 days, and no in-hospital deaths occurred. CONCLUSIONS: Simultaneous upper and lower body perfusion under moderate to deep hypothermia during thoracoabdominal aortic surgery may avoid not only spinal cord injury, but also cardiac and brain complications.

Safety of cerebrospinal fluid drainage in descending and thoracoabdominal aortic replacement surgery.

Background: Spinal cord injury (SCI) remains a significant morbidity of surgical repair of descending thoracic aortic aneurysms (DTAA) and thoracoabdominal aortic aneurysms (TAAA). We present our 17-year experience with cerebrospinal fluid drainage (CSFD) as a protective strategy during open surgical repair of descending and thoracoabdominal aortic disease. Methods: We conducted a retrospective chart review of 132 patients who underwent open surgical repair of DTAA and TAAA and dissections with concurrent use of CSFD for spinal cord protection. Information regarding survival, postoperative course, and complications related to CSFD use were extracted from electronic health records (EHR) and analyzed. Results: Mean patient age was 65.4±13.0 years, and 82 (62.1%) were male. A CSFD was successfully inserted in all patients. The mean hospital length of stay after surgery was 12.2±11.2 days, and in-hospital mortality was 7.6%. Postoperative transient paresis was observed in 5 patients (3.8%), and permanent paraplegia was seen in 4 (3.0%). CSFD related complications were reported in 25 patients (19%). Complications included persistent cerebrospinal fluid (CSF) leakage, blood-tinged CSF (with subdural hematoma reported in 3 patients) and spinal cutaneous fistula in 9 (7%), 14 (11%), and 1 (1%), respectively. Long term survival was 50.9% at 15 years. Conclusions: CSFD is associated with minor complications, without major sequalae. It is a safe practice and likely contributes innocuously to decreased SCI in patients undergoing open repair of DTAA and TAAA.

Preparing the spinal cord - priming or preconditioning? A systematic review of experimental studies.

Objectives. Paraplegia is devastating complication associated with thoracic and thoracoabdominal aortic aneurysm repair. Vast evidence has been gathered on pre-, peri- and postoperative protective adjuncts aiming to minimize spinal cord ischemia. This review focuses on the pretreatment phase of open surgical or endovascular aortic procedures and gathers the experimental data on the interventional preconditioning and priming methods that increase the spinal cord ischemic tolerance. Design. By the start of March 2021, a systematic review was performed in PubMed, Scopus and Web of Science core collection to identify the articles that reported (i) either an ischemic preconditioning, remote ischemic preconditioning or priming method prior to (ii) experimental spinal cord ischemia performed in endovascular or open surgical fashion mimicking either thoracic, abdominal or thoracoabdominal aortic aneurysm procedures. (iii) The outcomes were reported via neurological, motor-evoked potential, somatosensory-evoked potential, histopathological, immunohistochemical, physiological analysis, or in different combinations of these measurements. Results. The search yielded 7802 articles, and 57 articles were included in the systematic review. The articles were assessed by the evaluated species, the utilized pretreatment, the measured protective effects, and the suggested underlying mechanisms. Conclusions. The reviewed articles showed several possible mechanisms in ischemic and remote ischemic preconditioning for prevention of spinal cord ischemia. The main suggested method for priming was arteriogenetic stimulus. Future studies should confirm these hints of arteriogenetic stimulus with more precise quantification of the protective recruitment process.

Patency of separate tube grafts for intercostal artery reconstruction: Size and length matter.

OBJECTIVES: Low patency is a major concern when using separate tube grafts for intercostal artery reconstruction. Our goal was to elucidate the optimal size and length of grafts from their patency and the computational fluid dynamics (CFD). METHODS: The patency, size and length of separate tube grafts were evaluated in 41 patients. Simulation of CFD was performed in a model derived from a patient with a patent 12-mm graft that was 15 mm long, with 2 simulation models with a smaller (8-mm) or longer (30-mm) graft. RESULTS: A total of 49 grafts were used for intercostal artery reconstruction. There was 1 in-hospital death and 2 spinal cord injuries. The patency rate, which could be evaluated in 46 grafts, was 63% (29/46). It was 71% (24/34) in thoracoabdominal aortic replacement and 42% (5/12) in descending aortic replacement. Among 14 patients in whom all grafts were occluded, no patients developed spinal cord injury. All grafts longer than 25 mm were occluded (n = 5). Eight- and 10-mm grafts showed better patency than 12-mm grafts in thoracoabdominal aortic replacement (P = 0.008) when grafts were shorter than 25 mm. Simulation of CFD revealed vortical flow within the 12-mm graft, which did not reach the intercostal orifice, whereas helical flow was maintained throughout the cardiac cycle within the 8-mm graft. CONCLUSIONS: Eight- and 10-mm grafts seemed better than 12-mm grafts, and grafts should be kept shorter than 25 mm. Simulation of CFD may shed light on the issue of the optimal intercostal artery reconstruction technique.

Direct and indirect activation of the adenosine triphosphate-sensitive potassium channel to induce spinal cord ischemic metabolic tolerance.

OBJECTIVES: The mitochondrial adenosine triphosphate-sensitive potassium channel is central to pharmacologically induced tolerance to spinal cord injury. We hypothesized that both direct and nitric oxide-dependent indirect activation of the adenosine triphosphate-sensitive potassium channel contribute to the induction of ischemic metabolic tolerance. METHODS: Spinal cord injury was induced in adult male C57BL/6 mice through 7 minutes of thoracic aortic crossclamping. Pretreatment consisted of intraperitoneal injection 3 consecutive days before injury. Experimental groups were sham (no pretreatment or ischemia, n = 10), spinal cord injury control (pretreatment with normal saline, n = 27), Nicorandil 1.0 mg/kg (direct and indirect adenosine triphosphate-sensitive potassium channel opener, n = 20), Nicorandil 1 mg/kg + carboxy-PTIO 1 mg/kg (nitric oxide scavenger, n = 21), carboxy-PTIO (n = 12), diazoxide 5 mg/kg (selective direct adenosine triphosphate-sensitive potassium channel opener, n = 25), and DZ 5 mg/kg+ carboxy-PTIO 1 mg/kg, carboxy-PTIO (n = 23). Limb motor function was assessed using the Basso Mouse Score (0-9) at 12-hour intervals for 48 hours after ischemia. RESULTS: Motor function was significantly preserved at all time points after ischemia in the Nicorandil pretreatment group compared with ischemic control. The addition of carboxy-PTIO partially attenuated Nicorandil's motor-preserving effect. Motor function in the Nicorandil + carboxy-PTIO group was significantly preserved compared with the spinal cord injury control group (P < .001), but worse than in the Nicorandil group (P = .078). Motor preservation in the diazoxide group was similar to the Nicorandil + carboxy-PTIO group. There was no significant difference between the diazoxide and diazoxide + carboxy-PTIO groups. CONCLUSIONS: Both direct and nitric oxide-dependent indirect activation of the mitochondrial adenosine triphosphate-sensitive potassium channel play an important role in pharmacologically induced motor function preservation.

Hybrid arch frozen elephant trunk repair for acute type A aortic dissection: Extra-anatomic subclavian reconstruction.

Acute type A aortic dissection is a life-threatening condition that confers significant early perioperative risk but is also associated with late aortic disease progression and the need for reintervention. Recent efforts to improve patient outcomes have focused on improving quality of care and extending treatment in the aortic root and arch to reduce late aortic events. The hybrid arch frozen elephant trunk technique facilitates a more aggressive distal aortic repair that may help mitigate the early and late deleterious effects of persistent false lumen perfusion. However, in the acute and emergency settings, management of the left subclavian artery remains a challenge. We present a step-by-step instructional guide on performing an emergency hybrid arch frozen elephant trunk procedure with emphasis on management of the difficult left subclavian artery. Our case report demonstrates a transthoracic aortoaxillary extra-anatomic bypass of the left axillary artery. We discuss the most important considerations when managing the left subclavian artery in an acute type A aortic dissection. Finally, we detail the benefits and limitations of the transthoracic aortoaxillary extra-anatomic technique and discuss other approaches to left subclavian artery reconstruction.

The application of modular multifunctional left heart bypass circuit system integrated with ultrafiltration in thoracoabdominal aortic aneurysm repair.

Open thoracoabdominal aortic aneurysm (TAAA) repair is a complex and challenging operation with a high incidence of serious complications, and high perioperative mortality and morbidity. Left heart bypass (LHB) is a circulatory support system used to perfuse the distal aorta during TAAA operation, and the advantages of LHB include guaranteeing distal perfusion, reducing the use of heparin, and diminishing the risk of bleeding and postoperative neurological deficits. In China, the circuit for TAAA repair is deficient, and far from the perfusion requirements. We designed a modular multifunctional LHB circuit for TAAA repair. The modular circuit consisted of cannulation pipelines, functional consumables connection pipelines, and accessory pipelines. The accessory pipelines make up lines for selective visceral perfusion and kidney perfusion, suckers and rapid infusion. The circuit can be assembled according to surgical requirements. The ultrafilter and heat exchanger are integrated into the circuit to fulfill the basic demands of LHB. The LHB circuit also has pipelines for selective visceral perfusion to the celiac artery and superior mesenteric artery and renal perfusion pipelines. Meanwhile, the reserved pipelines facilitate the quick switch from LHB to conventional cardiopulmonary bypass (CPB). The reserved pipelines reduce the time of reassembling the CPB circuit. Moreover, the rapid infusion was integrated into the LHB circuit, which can rapid infusion when massive hemorrhage during the open procedures such as exposure and reconstruction of the aorta. The ultrafiltration can diminish the consequent hemodilution of hemorrhage and rapid infusion. A hemoperfusion cartridge also can be added to reduce the systemic inflammatory during operation. The circuit can meet the needs of LHB and quickly switch to conventional CPB. No oxygenator was required during LHB, which reduce the use of heparin and reduce the risk of bleeding. The heat exchanger contributes to temperature regulation; ultrafiltration, arterial filter, and rapid-infusion facilitated the blood volume management and are useful to maintain hemodynamic stability. This circuit made the assembly of the LHB circuit more easily, and more efficient, which may contribute to the TAAA repair operation performed in lower volume centers easily. 26 patients who received TAAA repair under the modular multifunctional LHB from January 2018-March 2022 were analyzed, and we achieved acceptable clinical outcomes. The in-hospital mortality and 30-day postoperative mortality were 15.4%, and the postoperative incidences of paraparesis (4%), stroke (4%), and AKI need hemodialysis (12%) were not particularly high, based on the limited patients sample size in short research period duration.

Endovascular Repair of Descending Thoracic Aortic Aneurysms.

Descending thoracic aortic aneurysms (DTAAs) are an important cause of morbidity and mortality in the elderly. Once diagnosed, they should be surveilled and then repaired at a diameter of 5.5 to 6 cm, depending on the individual patient's physiologic and anatomic risk of repair. Thoracic endovascular aortic repair (TEVAR) is the preferred approach for repair and there are multiple procedural adjuncts that can expand indications for and use of TEVAR. Spinal cord injuries are an important and highly morbid complication after TEVAR and it is imperative to mitigate this risk.

Left heart bypass for repair of aortic coarctation in children: Technical tips and pitfalls.

Spinal cord injury secondary to coarctation repair in children is a serious, though relatively uncommon, complication. Several measures have been proposed to minimize this risk, which seems to affect more older children than neonates and those with inadequate collateral circulation. Left heart bypass has been proposed as a protective strategy.

Spinal Cord Protection for Thoracoabdominal Aortic Surgery.

Open and endovascular repairs of the descending thoracic and thoracoabdominal aorta are associated with a substantial risk of spinal cord injury, namely paraplegia. Endovascular repairs seem to have a lower incidence of spinal cord injury, but there have been no randomized trials comparing outcomes of open and endovascular repairs. Paraplegia occurs when collateral blood supply to the anterior spinal artery is impaired. The risk of spinal cord injury can be mitigated with perioperative protocols that include drainage of cerebrospinal fluid, avoidance of hypotension and anemia, intraoperative neurophysiologic monitoring, and advanced surgical techniques. Drainage of cerebrospinal fluid using a spinal drain decreases the risk of spinal cord ischemia by improving spinal cord perfusion pressure. However, cerebrospinal fluid drainage has risks including neuraxial and intracranial bleeding, and these risks need to be carefully weighed against its potential benefit. This review discusses current surgical management of descending thoracic and thoracoabdominal aortic disease, incidence of and risk factors for spinal cord injury, and elements of spinal cord protection protocols that pertain to anesthesiologists, with a focus on cerebrospinal fluid drainage.

The Future of Cardiothoracic Surgical Critical Care Medicine as a Medical Science: A Call to Action.

Cardiothoracic surgical critical care medicine (CT-CCM) is a medical discipline centered on the perioperative care of diverse groups of patients. With an aging demographic and an increase in burden of chronic diseases the utilization of cardiothoracic surgical critical care units is likely to escalate in the coming decades. Given these projections, it is important to assess the state of cardiothoracic surgical intensive care, to develop goals and objectives for the future, and to identify knowledge gaps in need of scientific inquiry. This two-part review concentrates on CT-CCM as its own subspeciality of critical care and cardiothoracic surgery and provides aspirational goals for its practitioners and scientists. In part one, a list of guiding principles and a call-to-action agenda geared towards growth and promotion of CT-CCM are offered. In part two, an evaluation of selected scientific data is performed, identifying gaps in CT-CCM knowledge, and recommending direction to future scientific endeavors.

The Use of Cangrelor Infusions After Endovascular Aortic Repair With Prophylactic Lumbar Drain Placement.

Perioperative lumbar drains commonly are placed for spinal cord protection in patients undergoing endovascular aortic repair. However, the logistics of postoperative neuraxial drain removal is challenging in the presence of systemic antithrombotic therapy. This retrospective case series describes the novel use of cangrelor infusions in this high-risk setting. All lumbar drains were placed preoperatively, and descriptive data were collected including cangrelor infusion duration, time to lumbar drain removal after the infusion discontinuation, clinical course, and overall patient outcomes. There were no neurologic complications associated with lumbar drain insertion or removal, and median time to lumbar drain removal was 150 minutes after cangrelor infusion discontinuation. While further study is needed to validate its efficacy and safety, this case series highlights the promise of cangrelor infusions for systemic antithrombotic therapy in the cardiovascular/surgical intensive care unit.

Perfusion management of thoracoabdominal aortic aneurysm repair using partial femoral to femoral cardiopulmonary bypass / 中华胸心血管外科杂志

Objective:Analysis the protective effect of the partial femoral to femoral cardiopulmonary bypass(CPB) on thoracoabdominal aortic aneurysm repair(TAAAR).Methods:From September 2016 to August 2020, 50 cases of TAAAR under partial CPB were performed at our hospital. Thirty males and 20 females with an average age of(40.5±12.4) years old(ranging 21 to 69 years old) were involved. Partial CPB without selective organ perfusion were applied at the early stage. Since November 2019, the adjunct of perfuse the celiac and superior mesenteric artery with warm blood and irrigate the renal artery with 4℃ HTK solution was used in TAAAR, and 25 patients were operated under this adjunct.Results:The average CPB time was(116.9±35.4) min, the lowest central body temperature during the partial CPB was(34.7±0.7)℃. Total early postoperative mortality was 6%(3/50, 3 deaths in partial CPB alone group). Paraplegia occurred in 4 cases(8%), new happened postoperative hemodialysis was in 6 cases(16%). Among the hemodialysis event, 2 cases(8%, 2/25) were in the group with selective organ perfusion, and 4 cases(16%, 4/25) in the group without using the adjunct.Conclusion:Mild hypothermic partial cardiopulmonary bypass combined with selective organ perfusion have protective effects on spinal cord and abdominal organ in patients underwent TAAAR.

Surgical ischemia and reperfusion of the spinal cord ­ effect on specific perfusion and neurological outcome. Experimental study / A sebészi gerincvelo ischemia és reperfusio hatása a specifikus átáramlásra és a neurológiai következményekre

Clamping of the thoracoabdominal aorta reduces perfusion of the spinal cord significantly, which clinically may present as paraparesis or paraplegia ­ devastating and unpredictable complications of open thoracoabdominal aortic surgery. Introduction of monitoring of evoked potentials and/or biochemical markers, methods increasing distal arterial pressure, indirect procedures enhancing residual flow (like liquor drainage), drugs, and use of hypothermia contributed to achieve better outcome. Preconditioning of spinal cord circulation is also a promising method. New endovascular techniques for thoracoabdominal aortic aneurysms and dissections reduced surgical trauma significantly. Despite all these progressions spinal cord ischemic damage is still a significant risk. To address this problem we carried out an experimental work using a canine model focusing on the protective effect of distal arterial perfusion, spinal fluid drainage, and their combination in a one hour setting of thoracoabdominal aortic clamping. In this paper we publish our data of circulatory and specific perfusion parameters of the spinal cord during and after declamping in correlation of final neurologic outcome.

Thoracoabdominal aneurysmectomy: Operative steps for Crawford extent II repair.

BACKGROUND: Open surgical repair remains the gold standard for treatment of thoracoabdominal aortic aneurysm (TAAA). Surgery aims to replace the whole length of the diseased distal aorta while protecting the spinal cord and the visceral organs to limit ischemia-related complications. The substantial associated surgical risks, including death, paraplegia, renal failure requiring permanent dialysis, and respiratory complications leading to prolonged intensive care unit stay, still outweigh the natural history of TAAA with conservative treatment. METHODS: We describe in detail our current approach to open extent II TAAA repair with a step-by-step illustration of the technique and the surgical adjuncts. RESULTS: We routinely perform left heart bypass with mild passive hypothermia (34°C), cerebrospinal fluid drainage, sequential aortic cross-clamping, monitoring of motor evoked potentials (MEPs) and cerebral, paraspinal, and lower limb oxygen saturation by near-infrared spectrometry, as well as selective visceral perfusion via the celiac and superior mesenteric arteries and renal protection with intermittent administration of Custodiol HTK (histidine-tryptophan-ketoglutarate) solution via the renal arteries. We advocate for individual branch reimplantation using a branched thoracoabdominal graft when possible, and we selectively reattach 1 or more pairs of the lower thoracic intercostal arteries and/or high lumbar arteries, even in the absence of a significant reduction in the MEPs signal. The distal anastomosis is usually constructed above the aortic bifurcation and occasionally to each iliac separately using a bifurcated graft. CONCLUSIONS: Favorable early outcomes and a durable TAAA repair can be achieved at experienced high-volume centers with standardized preoperative selection and multidisciplinary team-based intraoperative and postoperative management of these patients.

Anesthetic Management for Endovascular Repair of the Thoracic Aorta.

Thoracic endovascular aneurysm repair (TEVAR) is fast becoming the primary treatment of thoracic aortic aneurysms, thoracic aortic dissections, acute aortic injuries, and other conditions affecting the thoracic aorta. Patients scheduled for TEVAR tend to have a host of comorbid conditions, including coronary artery disease, diabetes, and chronic obstructive pulmonary disease. Intraoperative management should optimize end-organ perfusion, facilitate neuromonitoring, and adjust hemodynamic management. Complications include spinal cord injury, peripheral vascular injury, contrast-induced nephropathy, postimplantation syndrome, and endoleaks. Patients who undergo TEVAR require care in a postoperative environment where these complications can be rapidly detected and aggressively treated.