Distal aortic perfusion and cerebrospinal fluid drainage for thoracoabdominal and descending thoracic aortic repair: ten years of organ protection

Five-year outcomes of fenestrated and branched endovascular repair of complex aortic aneurysms based on aneurysm extent

OBJECTIVE

The aim of this study was to evaluate the 5-year outcomes of fenestrated/branched endovascular aortic repair (F/BEVAR) for the treatment of complex aortic aneurysms stratified by the aneurysm extent.

METHODS

Patients with the diagnosis of complex aortic aneurysm, who underwent F/BEVAR at a single center were included in this study and retrospectively analyzed. The cohort was divided according to the aneurysm extent, comparing group 1 (types I-III thoracoabdominal aneurysms [TAAAs]), group 2 (type IV TAAAs), and group 3 (juxtarenal [JRAAs], pararenal [PRAAs], or paravisceral [PVAAs] aortic aneurysms). The primary endpoints were 30-day and 5-year survival. The secondary endpoints were technical success, occurrence of spinal cord ischemia, primary patency of the visceral arteries, freedom from target vessel instability, and secondary interventions.

RESULTS

Of 436 patients who underwent F/BEVAR between July 2012 and May 2023, 131 presented with types I to III TAAAs, 69 with type IV TAAAs, and 236 with JRAAs, PRAAs, or PVAAs. All cases were treated under a physician-sponsored investigational device exemption protocol with a patient-specific company-manufactured or off-the-shelf device. Group 1 had significantly younger patients than group 2 or 3 respectively (69.6 ± 8.7 vs 72.4 ± 7.1 vs 73.2 ± 7.3 years; P < .001) and had a higher percentage of females (50.4% vs 21.7% vs 17.8%; P < .001). Prior history of aortic dissection was significantly more common among patients in group 1 (26% vs 1.4% vs 0.9%; P < .001), and mean aneurysm diameter was larger in group 1 (64.5 vs 60.7 vs 63.2 mm; P = .033). Comorbidities were similar between groups, except for coronary artery disease (P < .001) and tobacco use (P = .003), which were less prevalent in group 1. Technical success was similar in the three groups (98.5% vs 98.6% vs 98.7%; P > .99). The 30-day mortality was 4.5%, 1.4%, and 0.4%, in groups 1, 2, and 3, respectively, and was significantly higher in group 1 when compared with group 3 (P = .01). The incidence of spinal cord ischemia was significantly higher in group 1 compared with group 3 (5.3% vs 4.3% vs 0.4%; P = .004). The 5-year survival was significantly higher in group 3 when compared with group 1 (P = .01). Freedom from secondary intervention was significantly higher in group 3 when compared with group 1 (P = .003). At 5 years, there was no significant difference in freedom from target vessel instability between groups or primary patency in the 1652 target vessels examined.

CONCLUSIONS

Larger aneurysm extent was associated with lower 5-year survival, higher 30-day mortality, incidence of secondary interventions, and spinal cord ischemia. The prevalence of secondary interventions in all groups makes meticulous follow-up paramount in patients with complex aortic aneurysm treated with F/BEVAR.

Health Related Quality of Life Following Intervention for Thoracoabdominal Aortic Aneurysm: A Systematic Review and Narrative Synthesis

BACKGROUND

Thoracoabdominal aortic aneurysms (TAAA) pose significant risks of morbidity and mortality. Considering the evolving techniques for TAAA intervention and the growing interest in quality of life (QoL) outcomes for decision-making, we aimed to evaluate the impact of patient and perioperative characteristics on short-term, medium-term, and long-term postoperative QoL in TAAA repair patients.

METHODS

A systematic search was conducted in CINAHL, APA PsycINFO, EMBASE, Medline and Cochrane to identify primary research studies evaluating QoL post TAAA surgery, published in English or Swedish between January 01, 2012 and September 26, 2022. A narrative synthesis was reported according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses statement. The quality of evidence was assessed using the Critical Appraisal Skills Program and Joanna Briggs Institute checklists.

RESULTS

Eight studies of low or moderate quality with 455 patients were included. Preoperative QoL in TAAA patients was lower compared to the general population. While there is an initial short-term improvement in postoperative QoL, patients fail to reach baseline levels even after 7 years, with physical activity and functioning domains being particularly affected. Experiencing postoperative complications, including paraplegia and cardiovascular events, negatively impacts postoperative QoL. Patients with uncomplicated postoperative status had improved QoL. Prolonged hospital stay negatively affects physical functioning.

CONCLUSIONS

Individuals with TAAA are likely to have lower baseline QoL compared to the general population. Following TAAA repair, postoperative QoL may remain lower than baseline levels, persisting over the long-term. Comorbidities, postoperative complications, and hospitalization duration appear to exert adverse effects on postoperative QoL.

Administration with curcumin alleviates spinal cord ischemia-reperfusion injury by regulating anti-oxidative stress and microglia activation-mediated neuroinflammation via Nrf2/NF-κB axis

Spinal cord ischemia-reperfusion injury (SCII) ranks as the common complication after aortic surgery, usually leading to devastating post-operative paraplegia. Microglia over-activation and neuronal cell loss are key pathological features of SCII. Curcumin is involved in several I/R injuries. However, its underlying mechanism in SCII remains elusive. Here, curcumin attenuated oxygen and glucose deprivation/reoxygenation (OGD/R)-induced oxidative injury in PC12 neuronal cells by increasing cell viability, inhibiting cell apoptosis, lactate dehydrogenase, malondialdehyde levels, but elevating anti-oxidative superoxide dismutase and glutathione peroxidase levels. Furthermore, curcumin restrained OGD/R-evoked microglia M1 activation by decreasing microglia M1 polarization marker IBA-1 and iNOS transcripts. Moreover, the increased inflammatory cytokine levels of TNF-α and IL-6 in microglia under OGD/R conditions were suppressed after curcumin treatment. Importantly, neuronal cells incubated with a conditioned medium from OGD/R-treated microglia exhibited lower cell viability and higher apoptotic ratio, which were overturned when microglia were treated with curcumin. Intriguingly, curcumin could inhibit the activation of the NF-κB pathway by Nrf2 enhancement in OGD/R-treated PC12 cells and microglia. Notably, targeting Nrf2 signaling reversed the protective efficacy of curcumin against OGD/R-evoked oxidative insult in neuronal, microglia M1 activation, inflammatory response, and microglial activation-evoked neuronal death. In vivo, curcumin improved histopathologic injury and neurologic motor function in SCII rats and attenuated oxidative stress, microglia activation and neuroinflammation in spinal cord tissues, and activation of the Nrf2/NF-κB pathway. Thus, curcumin may alleviate SCII by mitigating I/R-evoked oxidative injury in neuron and microglia activation-induced neuroinflammation and neuron death through Nrf2/NF-κB signaling, supporting a promising therapeutic agent for SCII.

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.

Outcomes of open repair for descending thoracic and thoracoabdominal aortic aneurysm in recent 10 years: experience of a high-volume centre in Korea

OBJECTIVES

Although recent studies and guidelines suggest the preferred outcomes after surgical repair of thoracic aortic aneurysm (TAA) and thoracoabdominal aortic aneurysm (TAAA), published results are limited to those from high-volume hospitals and based on old data gathered before optimal management was established. Here, we analysed our outcomes over the previous 10 years from cases of open TAA and TAAA repair to offer updated and real-world results of those complex procedures performed in a high-volume centre.

METHODS

From November 2013 to April 2022, 212 consecutive adult patients who underwent open TAA and TAAA repair were enrolled. We analysed early and late outcomes after surgery, including postoperative complications and mortality.

RESULTS

There were 154 (73%) men, and the median age at surgery was 61 years. Intraoperative death occurred in 1 patient due to uncontrolled bleeding. Nine patients (4%) died during follow-up, and the survival estimates at 5 years were 94 ± 3% and 95 ± 3% after descending TAA and TAAA repair, respectively. Ten patients (4%) suffered from spinal cord ischaemic injury (9 with paraplegia and 1 with paresthesia), but permanent paraplegia persisted in only 1 case.

CONCLUSIONS

We report very low postoperative complication rates and excellent early and late survival rates after open TAA and TAAA repair from our recent 10-year data analysis. These findings may assist when choosing treatment options for these complicated diseases.

A multidisciplinary multistage complete mega aorta replacement and utilization of extracorporeal membrane oxygenation in thoracoabdominal aneurysm repair

A 49-year-old woman underwent a 11-month multistage complete replacement of a mega aorta. Replacement stages included ascending aorta and arch replacement in conjunction with a frozen elephant trunk thoracic endovascular aortic repair, extension of thoracic endovascular aortic repair to zone 5, and open repair of the thoracoabdominal aneurysm with the use of venoarterial extracorporeal membrane oxygenation for circulatory support. This case illustrates the complexity of repairing a mega aorta, the multidisciplinary care and staging needed for repair, and the use of peripheral venoarterial extracorporeal membrane oxygenation for circulatory perfusion during thoracoabdominal aneurysm repair.

Open and endovascular repair of thoracoabdominal aortic aneurysm-a narrative review

Background and Objective

Thoracoabdominal aortic aneurysms (TAAAs) are associated with a high rate of morbidity and mortality when left untreated, yet their repair has been associated considerable risk as well. We aim to present a review of the epidemiology, risk factors, pathophysiology, natural history, management strategies, and current literature on open and endovascular repair of thoracoabdominal aortic aneurysms.

Methods

A narrative review using current search of the most recent literature on this topic.

Key Content and Findings

Indication for surgical repair includes symptomatic aneurysms and those at a size or growth threshold. Open repair is the gold standard for surgical management of TAAA and remains so, however, endovascular repair has an increasingly broad applicability, and technology has correspondingly improved in the two decades since its introduction to clinical practice. Reported contemporary operative mortality has ranged from less than 5% to over 20%. The primary adverse complication of open and endovascular repair is ischemic injury, including renal injury, with reported incidence ranging from 2.8-12.5% in contemporary series, and spinal cord injury, with reported incidence ranging from 2.5% to 7.3% in contemporary series. Cerebrospinal fluid drainage has been shown to be the best-proven mechanism to date to prevent spinal cord injury in both open and endovascular repair.

Conclusions

Endovascular repair is associated with a higher reintervention rate than open repair. Surgeon and center volume and expertise are related to clinical outcomes and should be taken into consideration when deciding on surgical repair.

Protecting the spinal cord during thoracic endovascular aortic repair-who should place the spinal drain?

A well-placed and functioning lumbar spinal drain, for spinal cord protection, is an important aspect of the perioperative care of patients undergoing thoracic endovascular aortic repair (TEVAR) procedures. Spinal cord injury (SCI) is a devastating complication of TEVAR procedures and is most often associated with Crawford type 2 repairs. Current evidence-based guidelines for the surgical management of patients with thoracic aortic disease include the role of lumbar spine catheter placement and drainage of cerebrospinal fluid (CSF) intraoperatively as part of a strategy to prevent spinal cord ischemia. More often than not, the procedure of lumbar spinal drain placement, using a standard blind technique, and subsequent drain management is the responsibility of the anesthesiologist. However, institutional protocols are inconsistent, and, failure to successfully place the lumbar spinal drain pre-operatively in the operating room, in clinical situations such as patients with poor anatomical landmarks or prior back surgery, presents a clinical dilemma and impacts spinal cord protection during TEVAR. Although a relatively safe procedure, potential complications of lumbar spine catheter placement range from a self-limiting headache to hemorrhage and permanent neurological injury. Spinal drain placement with image-guided fluoroscopy by interventional radiology should be considered in the preoperative assessment and planning and is an alternative to conventional, blind lumbar drain insertion.

Mildronate Has Ameliorative Effects on the Experimental Ischemia/Reperfusion Injury Model in the Rabbit Spinal Cord

BACKGROUND

Mildronate is a useful anti-ischemic agent and has antiinflammatory, antioxidant, and neuroprotective activities. The aim of this study is to investigate the potential neuroprotective effects of mildronate in the experimental rabbit spinal cord ischemia/reperfusion injury (SCIRI) model.

METHODS

Rabbits were randomized into 5 groups of 8 animals as groups 1 (control), 2 (ischemia), 3 (vehicle), 4 (30 mg/kg methylprednisolone [MP]), and 5 (100 mg/kg mildronate). The control group underwent only laparotomy. The other groups have the spinal cord ischemia model by a 20-minute aortic occlusion just caudal to the renal artery. The malondialdehyde and catalase levels and caspase-3, myeloperoxidase, and xanthine oxidase activities were investigated. Neurologic, histopathologic, and ultrastructural evaluations were also performed.

RESULTS

The serum and tissue myeloperoxidase, malondialdehyde, and caspase-3 values of the ischemia and vehicle groups were statistically significantly higher than those of the MP and mildronate groups (P < 0.001). Serum and tissue catalase values of the ischemia and vehicle groups were statistically significantly lower than those of the control, MP, and mildronate groups (P < 0.001). The histopathologic evaluation showed a statistically significantly lower score in the mildronate and MP groups than in the ischemia and vehicle groups (P < 0.001). The modified Tarlov scores of the ischemia and vehicle groups were statistically significantly lower than those of the control, MP, and mildronate groups (P < 0.001).

CONCLUSIONS

This study presented the antiinflammatory, antioxidant, antiapoptotic, and neuroprotective effects of mildronate on SCIRI. Future studies will elucidate its possible use in clinical settings in SCIRI.

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.

A Comprehensive Research Schema for the Characterization of Aortic Aneurysms

A robust, accurate, and standardized approach to measurement of the aorta is critical to improve the predictive accuracy of these aortic measurements, and to investigate other aortic imaging biomarkers. Developing a comprehensive and generic schema for characterization of the aorta to enable investigators to standardize data that are collected across all aorta research. A systematic review of the literature was conducted to identify and assess schemata of aortic measurement and description. The schemata were reported and discussed to guide the synthesis of a comprehensive schema. We propose the International College of Angiology Aortic Research Schema as a comprehensive design that fills the gaps left behind by previously reported schemata. It is intended to be applicable for all clinically relevant purposes, including endograft development for aneurysm repair and for the accurate characterization of the aortic anatomy. This schema divides the aorta into 14 segments and 2 sections (thoracic and abdominal aortas). The segmentation proposed can be used in addition to specific measurements taken for any aneurysm including the neck, and maximal and minimal diameters of the aneurysm.

Renal perfusion with histidine-tryptophan-ketoglutarate compared with Ringer's solution in patients undergoing thoracoabdominal aortic open repair

OBJECTIVE

The objective of this study was to compare the efficacy of renal perfusion with Custodiol (Dr Franz-Kohler Chemie GmbH, Bensheim, Germany) versus enriched Ringer's solution for renal protection in patients undergoing open thoracoabdominal aortic aneurysm (TAAA) repair.

METHODS

Ninety consecutive patients scheduled for elective open TAAA repair were enrolled between 2015 and 2017 in a single-center, phase IV, prospective, parallel, randomized, double-blind trial (the CUstodiol versus RInger: whaT Is the Best Agent [CURITIBA] trial), and randomized to renal arteries perfusion with 4°C Custodiol (Dr Franz-Kohler Chemie GmbH, Bensheim, Germany; n = 45) or 4°C lactated Ringer's solution (n = 45). The incidence of acute kidney injury (AKI) in patients undergoing TAAA open surgery using Custodiol renal perfusion versus an enriched Ringer's solution was the primary end point.

RESULTS

Ninety patients completed the study (45 patients in each group). The incidence of postoperative AKI was significantly lower in the Custodiol group (48.9% vs 75.6%; P = .02). In the multivariable model, only the use of Custodiol solution resulted as protective from the occurrence of any AKI (odds ratio, 0.230; 95% confidence interval, 0.086-0.614; P = .003), whereas TAAA type II extent was associated with the development of severe AKI (odds ratio, 4.277; 95% confidence interval, 1.239-14.762; P = .02). At 1-year follow-up, serum creatinine was not significantly different from the preoperative values in both groups.

CONCLUSIONS

The use of Custodiol during open TAAA repair was safe and resulted in significantly lower rates of postoperative AKI compared with Ringer's solution. These findings support safety and efficacy of Custodiol in this specific setting, which is currently off-label.

Open Treatments for Thoracoabdominal Aortic Aneurysm Repair

Thoracoabdominal aortic aneurysms (TAAA) represent a unique pathology that is associated with considerable mortality if untreated. While the advent of endovascular technologies has introduced new modalities for consideration, the mainstay of TAAA treatment remains open surgical repair. However, the optimal conduct of open TAAA repair requires careful consideration of patient risk factors and a collaborative team effort to mitigate the risk of perioperative complications. In this chapter, we briefly outline the history of treating TAAA, preoperative preparation and postoperative care, and our operative techniques for treatment.

Cerebrospinal Fluid Drainage for Prevention of Spinal Cord Ischemia in Thoracic Endovascular Aortic Surgery-Pros and Cons

Thoracic endovascular aortic repair (TEVAR) carries a risk of spinal cord ischemia (SCI) which exerts a devastating impact on patient's quality of life and life expectancy. Although routine prophylactic cerebrospinal fluid (CSF) drainage is not unequivocally supported by current data, several studies have demonstrated favorable outcomes. Patients at high risk for SCI following TEVAR likely will benefit from prophylactic CSF drains. However, the intervention is not risk free, and thorough risk/benefit analysis should be individualized to each patient.

Neuroprotective Effects of Dexpanthenol on Rabbit Spinal Cord Ischemia/Reperfusion Injury Model

OBJECTIVE

Dexpanthenol (DXP) reportedly protects tissues against oxidative damage in various inflammation models. This study aimed to evaluate its effects on oxidative stress, inflammation, apoptosis, and neurological recovery in an experimental rabbit spinal cord ischemia/reperfusion injury (SCIRI) model.

METHODS

Rabbits were randomized into 5 groups of 8 animals each: group 1 (control), group 2 (ischemia), group 3 (vehicle), group 4 (methylprednisolone, 30 mg/kg), and group 5 (DXP, 500 mg/kg). The control group underwent laparotomy only, whereas other groups were subjected to spinal cord ischemia by aortic occlusion (just caudal to the 2 renal arteries) for 20 min. After 24 h, a modified Tarlov scale was employed to record neurological examination results. Malondialdehyde and caspase-3 levels and catalase and myeloperoxidase activities were analyzed in tissue and serum samples. Xanthine oxidase activity was measured in the serum. Histopathological and ultrastructural evaluations were also performed in the spinal cord.

RESULTS

After SCIRI, serum and tissue malondialdehyde and caspase-3 levels and myeloperoxidase and serum xanthine oxidase activities were increased (P < 0.05-0.001). However, serum and tissue catalase activity decreased significantly (P < 0.001). DXP treatment was associated with lower malondialdehyde and caspase-3 levels and reduced myeloperoxidase and xanthine oxidase activities but increased catalase activity (P < 0.05-0.001). Furthermore, DXP was associated with better histopathological, ultrastructural, and neurological outcome scores.

CONCLUSIONS

This study was the first to evaluate antioxidant, anti-inflammatory, antiapoptotic, and neuroprotective effects of DXP on SCIRI. Further experimental and clinical investigations are warranted to confirm that DXP can be administered to treat SCIRI.

A Case of Decreased Amplitude in Motor Evoked Potentials Under Remimazolam Anesthesia

Remimazolam is a newly developed benzodiazepine derivative. Although one case report on the use of remimazolam for motor evoked potential (MEP) monitoring has been reported, there has been no report of changes in the MEP response under remimazolam anesthesia, which is associated with impairment of the corticospinal motor track. This is a case of a 54-year-old woman who was diagnosed with an extradural extramedullary tumor. The patient reported being allergic to chicken eggs. We used remimazolam instead of propofol for anesthesia management. During tumor resection, the amplitudes of MEP responses at the left quadriceps femoris, left tibialis anterior, and left abductor hallucis muscle decreased. The surgery was scaled down and the tumor was removed in a reduced size. The patient had muscle weakness immediately after surgery but eventually recovered. In this case, we could detect changes in MEP response under remimazolam anesthesia, which suggested impairment of the motor tracts during surgery.

Brown–Séquard Syndrome after Thoracic Endovascular Aortic Repair for a Stanford Type B Aortic Dissection

We present a case of Brown–Séquard syndrome (BSS) after thoracic endovascular aortic repair (TEVAR) to treat Stanford type B aortic dissection. A 49-year-old male presented to the emergency department with acute tearing pain between the scapulae, connected to respiratory movements. Computed tomography showed Stanford type B aortic dissection from the left subclavian artery to the level of the 11th thoracic vertebra. Conservative treatment was initiated with intravenous antihypertensives. However, due to persistent pain and an increase in the aortic diameter with an intramural hematoma, TEVAR was performed. The patient developed symptoms suspicious of spinal cord ischemia postoperatively. A lesion limited to the left-sided spinal cord was observed on magnetic resonance imaging at the level of the 4th to 5th thoracic vertebra. BSS after TEVAR is a rare phenomenon with a fairly good prognosis, depending on the initial injury severity.

Neuromonitoring during descending aorta procedures

Thoraco-abdominal aneurysm (TAA) repair carries a significant risk of spinal cord infarction. The latter results from irreversible changes in the spinal cord arterial network, e.g., sacrifice of the segmental arteries. Intra-operative neurophysiology with somatosensory and especially motor evoked potential (SEP and MEP respectively) monitoring, has emerged as an effective tool to assess the efficiency of the collateral blood flow, detect reversible spinal cord ischemia and guide the peri-operative multidisciplinary management to prevent postoperative paraplegia. The main roles of such monitoring include diagnosis of spinal cord vs peripheral limb ischemia, titration of mean arterial pressure during aortic clamping, the guidance of selective re-implantation of critical segmental arteries, and management of hemodynamics in the immediate postoperative period. In addition, manipulation of the aortic arch and proximal descending aorta, adds the risk of cerebral infarction from both low flow state and/or thromboembolic events. As such, EEG monitoring may be a useful add-on for either assessment of the efficiency of cerebral cooling as a neuroprotective method and/or for detection and treatment of reversible cerebral ischemia. This chapter presents the multimodality approach to open TAA monitoring as a versatile tool for the prevention of devastating postoperative neurologic deficits.

Distinct Polarization Dynamics of Microglia and Infiltrating Macrophages: A Novel Mechanism of Spinal Cord Ischemia/Reperfusion Injury

Purpose

Recent studies indicate that microglia and monocyte-derived macrophages (MDMs) have different roles in diseases such as stroke and spinal cord injury, yet their respective polarized phenotypes and roles remain unclear in spinal cord ischemia/reperfusion injury (SCIRI).

Methods

We established a mouse model of SCIRI by transient aortic occlusion followed by reperfusion. Basso mouse scale (BMS) scores were used to test the locomotor functions. The histopathological changes in spinal cord were assessed by hematoxylin-eosin staining and NF-200 immunohistochemistry. Real-time PCR, immunofluorescence and flow cytometry were employed to analyze the polarized phenotypes of the microglia and infiltrating MDMs, and the resulting inflammatory responses. Furthermore, the role of infiltrating MDMs were investigated by MDMs depletion using systemic administration of clodronate-liposomes.

Results

SCIRI significantly impaired locomotor function of mice, accompanied with progressed necrosis, infiltration of inflammatory cells and neuron loss in the spinal cord. M1-related pro-inflammatory markers (iNOS, CD16, CD86 and TNF-α) increased dramatically in the early phase following SCIRI. In contrast, M2-related anti-inflammatory markers (CD204 and CD206) elevated at later stage. Besides, the invading MDMs were principally pro-inflammatory M1 type, transiently restricted to the first week after SCIRI. In contrast, microglia were the main source of anti-inflammatory M2 type. Furthermore, depletion of MDMs by clodronate-liposomes significantly preserved neurological functions and relieved neuronal damage caused by SCIRI.

Conclusion

These findings suggested distinct polarized status of resident microglia and MDMs following SCIRI. Inhibition of the invading MDMs may represent a novel approach for SCIRI treatment.

Hemodynamic Patterns of Spinal Cord Perfusion in Thoracoabdominal Aortic Aneurysm Repair

Paraplegia in aortic surgery is due to its impact on spinal cord perfusion whose hemodynamic patterns (SCPHP) are not clearly defined. Detailed morphological analysis of vascular network and collateral network modifications within Monro-Kellie postulate due to the fixed theca confines was performed to identify SCPHP. SCPHP may begin with intraspinal "backflow" (I-BF), that is, hemorrhage from anterior and posterior spinal arteries, backward via the connected anterior and posterior radicular medullary arteries, through the increasing diameter and decreasing resistance of segmental arteries (SAs), off their aortic orifices outside vascular network at 0 operative field pressure. The I-BF blood bypasses both intra- and extraspinal capillary networks and causes depressurization (0 diastolic pressure) and full ischemia of dependent spinal cord. When the occlusion of those SAs orifices arrests I-BF, the hemodynamic pattern of intraspinal "steal" (I-S) may take place. The formerly I-BF blood, in fact, is now variably shared between the fraction maintained in its physiological intraspinal network and that keeping flowing as I-S through the extraspinal capillary network. I-S is, however, counteracted by the extraspinal "steal" from the connected mammary/paraspinous-independent extraspinal feeders, all physically competing for the same room left by the missed physiological SA direct aortic blood inflow. Steal phenomenon evolves within the 120-hour time frame of CNm, whose intraspinal anatomical changes may offer the physical basis within the Monro-Kelly postulate, respectively of the intraoperative and postoperative paraplegia. The current procedures could not prevent the unphysiological SCPHP but awareness of details of their various features may offer the basis for improvements tailored, to the adopted intra- and postoperative procedures.

The Evolution and Future of Spinal Drain for Thoracic Aortic Aneurysm Repair: A Review

For decades, spinal drains for cerebrospinal fluid (CSF) pressure monitoring and drainage have been used as adjuncts to protect against spinal cord injury resulting from thoracic aortic aneurysm repair. There are many different approaches to placement and management of CSF drains, with no true consensus on best practice. Furthermore, the incidence of complications resulting from spinal drains largely has been stagnant. This review describes the history and rationale behind placement of CSF drains, explore various considerations, techniques, and equipment, and discuss potential considerations for developing more comprehensive protocols.

Effect of cerebrospinal fluid pressure elevation on spinal cord perfusion during aortic cross-clamping with distal aortic perfusion

 

OBJECTIVES

Distal aortic perfusion (DaP) is a widely accepted protective adjunct facilitating early reinstitution of visceral perfusion during extended thoracic and thoraco-abdominal aortic repair. DaP has also been suggested to secure distal inflow to the paraspinal collateral network via the hypogastric arteries and thereby reduce the risk of spinal cord ischaemia. However, an increase in cerebrospinal fluid (CSF) pressure is frequently observed during thoracoabdominal aortic aneurysm repair. The aim of this study was to evaluate the effects of DaP on regional spinal cord blood flow (SCBF) during descending aortic cross-clamping and iatrogenic elevation of cerebrospinal fluid pressure.

METHODS

Eight juvenile pigs underwent central cannulation for cardiopulmonary bypass according to our established experimental protocol followed by aortic cross-clamping of the descending thoracic and abdominal aorta-mimicking sequential aortic clamping-with the initiation of DaP. Thereafter, CSF pressure elevation was induced by the infusion of blood plasma until baseline CSF pressure was tripled. At each time-point, microspheres of different colours were injected allowing for regional SCBF analysis.

RESULTS

DaP led to a pronounced hyperperfusion of the distal spinal cord [SCBF up to 480%, standard deviation (SD): 313%, compared to baseline]. However, DaP provided no or only limited additional flow to the upper and middle segments of the spinal cord (C1-Th7: 5% of baseline, SD: 5%; Th8-L2: 24%, SD: 39%), which was compensated by proximal flow only at C1-Th7 level. Furthermore, DaP could not counteract an experimental CSF pressure elevation, which led to a further decrease in regional SCBF most pronounced in the mid-thoracic spinal cord segment.

CONCLUSIONS

Protective DaP during thoraco-abdominal aortic repair may be associated with inadequate spinal protection particularly at the mid-thoracic spinal cord level ('watershed area') and result in the adverse effect of a potentially dangerous hyperperfusion of the distal spinal cord segments.

Open thoracoabdominal aortic aneurysm surgery technique: how we do it

More than four decades have passed since the modern principals to treat thoracoabdominal aortic aneurysm (TAAA) have been established. The historical challenges in repair of TAAA are represented by - and continue to be - multiorgan protection. Among all organs, the spinal cord remains one of the most vital and vulnerable. We described our current techniques of open extent II TAAA repair, including the following topics: anesthesia, intraoperative monitoring, skin incision, exposure of the TAAA, left heart bypass, graft replacement technique, intercostal artery reattachment, visceral/renal artery reconstructions, and postoperative care. We use cerebrospinal fluid drainage, distal aortic perfusion, mild passive hypothermia, sequential clamping, and visceral and renal perfusion using roller pump in all the cases for multiorgan protection. Both motor-evoked potentials and somatosensory-evoked potentials ere used to guide the conduct of intercostal artery reattachment. Our group demonstrated that the use of adjuncts has reduced the overall spinal cord ischemia rate after Extent I TAAA from 15% to less than 2% and after Extent II TAAA from 33% (50% with clamp time exceeding 40 minutes in "clamp and go" era) to less than 4%. The current standard practice of TAAA repair with adjuncts has improved outcomes, especially regarding spinal cord ischemia.

Safety of perioperative cerebrospinal fluid drain as a protective strategy during descending and thoracoabdominal open aortic repair

Objective

We present our experience with routine application of the cerebrospinal fluid (CSF) drain (CSFD) during open aortic repair.

Methods

We retrospectively reviewed 100 patients with descending thoracic aortic aneurysm (DTAA) or thoracoabdominal aortic aneurysm (TAAA) or who underwent CSFD insertion before open repair between 2006 and 2017. All CSFDs were inserted by the cardiovascular anesthesia team. The goal was to keep intracranial pressure <10 mm Hg during the surgical procedure by draining CSF at a rate of 20 to 30 mL/h. Postoperatively, CSFD was set to maintain the lumbar pressure <10 mm Hg to reduce the risk of postoperative paraplegia. CSFD was part of our standard cord protection regimen.

Results

The mean patient age was 65.4 ± 11.7 years, and 60 (60%) were male. A CSFD was successfully inserted in all patients. The mean hospital length of stay was 11.9 ± 11.8 days, and hospital mortality was 6%. Postoperative transient paresis was observed in 4 patients (4%), and permanent paraplegia was seen in 2 (2%). CSFD-related complications were reported in 14 patients (14%). Complications included persistent CSF leakage and blood-tinged CSF with and without intracranial hemorrhage and spinal cutaneous fistula in 7 (7%), 9 (9%), and 1 (1%), respectively. Long-term survival was excellent (68.4% at 10 years).

Conclusions

CSFD is a safe practice when applied routinely as an adjunct strategy to prevent paraplegia in surgical management of DTAA and TAAA. We feel that this contributed to good early and late clinical results.

Cerebrospinal fluid drainage to prevent postoperative spinal cord injury in thoracic aortic repair

BACKGROUND

Cerebrospinal fluid drainage (CSFD) is recommended as a spinal cord protective strategy in open and endovascular thoracic aortic repair. Although small studies support the use of CSFD, systematic reviews have not suggested definite conclusion and a large-scale study is needed. Therefore, we reviewed medical records of patients who had undergone descending and thoracoabdominal aortic repair (both open and endovascular repair) at multiple institutions to assess the association between CSFD and postoperative motor deficits.

METHODS

Patients included in this study underwent descending or thoracoabdominal aortic repair between 2000 and 2013 at 12 hospitals belonging to the Japanese Association of Spinal Cord Protection in Aortic Surgery. We conducted a retrospective study to investigate whether motor-evoked potential monitoring is effective in reducing motor deficits in thoracic aortic aneurysm repair. We use the same dataset to examine whether CSFD reduces motor deficits after propensity score matching.

RESULTS

We reviewed data from 1214 patients [open surgery, 601 (49.5%); endovascular repair, 613 (50.5%)]. CSFD was performed in 417 patients and not performed in the remaining 797 patients. Postoperative motor deficits were observed in 75 (6.2%) patients at discharge. After propensity score matching (n = 700), mixed-effects logistic regression performed revealed that CSFD is associated with postoperative motor deficits at discharge [adjusted odds ratio (OR), 3.87; 95% confidence interval (CI), 2.30-6.51].

CONCLUSION

CSFD may not be effective for postoperative motor deficits at discharge.

Nanobubble technology to treat spinal cord ischemic injury

Background

Spinal cord ischemic injury is a severe complication of aortic surgery. We hypothesized that cerebrospinal fluid (CSF) oxygenation with nanobubbles after reperfusion could ameliorate spinal cord ischemic injury.

Methods

Twenty white Japanese rabbits were categorized into 4 groups of 5 rabbits each: sham group, with balloon catheter insertion into the aorta; ischemia group, with spinal cord ischemic injury by abdominal aortic occlusion; nonoxygenated group, with nonoxygenated artificial CSF irrigation after spinal cord ischemic injury; and oxygenated group, with oxygenated artificial CSF irrigation after spinal cord ischemic injury. At 48 hours after spinal cord ischemic injury, the modified Tarlov score to reflect hind limb movement was evaluated. The spinal cord was histopathologically examined by counting anterior horn cells, and microarray and quantitative reverse-transcription polymerase chain reaction (qRT-PCR) analyses were performed.

Results

The oxygenated group showed improved neurologic function compared with the ischemia and nonoxygenated groups (P < .01 and P = .019, respectively). Anterior horn neuron prevention in the sham, nonoxygenated, and oxygenated groups was confirmed (mean modified Tarlov score: sham, 9.2 ± 1.9; nonoxygenated, 10.2 ± 2.2; oxygenated, 10.4 ± 2.2; ischemia, 2.7 ± 2.7). Microarray analysis identified 644 genes with twofold or greater increased signals between the ischemia and sham groups. Thirty-three genes related to inflammatory response were enriched among genes differentially expressed between the oxygenated and ischemia groups. Interleukin (IL)-6 and tumor necrosis factor (TNF) expression levels were significantly lower in the oxygenated group compared with the ischemia group, while qRT-PCR showed lower IL-6 and TNF expression levels in the oxygenated group compared with the ischemia group (P < .05).

Conclusions

CSF oxygenation with nanobubbles after reperfusion can ameliorate spinal cord ischemic injury and suppress inflammatory responses in the spinal cord.

Protocol of supra-visceral aortic ischemic preconditioning for open surgical repair of thoracoabdominal aortic aneurysm : The EPICATA study (Evaluation of the Efficacy of Ischemic PreConditioning on morbidity and mortality in open ThoracoAbdominal Aortic surgery)

Background

Open surgical repair (OSR) for thoracoabdominal aortic aneurysms (TAA) is associated with a high pulmonary and renal morbidity rate. Ischemic preconditioning (IPC) is a mechanism of protection against the deleterious effects of ischemia-reperfusion. To our knowledge IPC has never been tested during OSR for TAA.

Methods

The primary objective of the study is to evaluate the efficacy of IPC during OSR for TAA with respect to acute kidney injury (AKI) according to KDIGO and pneumonia/prolonged ventilation-time during the first 8 postoperative days. The secondary objectives are to compare both arms with respect to cardiac complications within 48 h, renal and pulmonary complications within 21 days and mortality at 60 days.

To assess the efficacy of IPC with respect to pulmonary and renal morbidity, a cox model for competing risks will be used. Assuming that the event occurs among 36% of the patients when no IPC is performed, the allocation of 55 patients to each arm should allow detecting a hazard ratio of at least 2.75 with a power of 80% when admitting 5% for an error of first kind. This means that 110 patients, enrolled in this multicenter study, may be randomised within 36 months of the first randomization.

Randomization will be performed to allocate patients either to surgery with preconditioning before aortic cross clamping (Arm 1) or to surgery without preconditioning before aortic cross clamping (Arm 2).

Randomization takes place during the intervention after intravenous injection of heparin, or after the start of femoral assistance. The procedure for IPC will be a supra-visceral thoracic aortic cross clamping for 5 min followed by an unclamping period of 5 min. This procedure will be repeated twice before starting thoracic aortic cross clamping needed to perform surgery.

Conclusions

Our hypothesis is that ischemic preconditioning could reduce clinical morbidity and the incidence of lung damage associated with supra-visceral aortic clamping.

Trial registration

EPICATAStudy registered in ClinicalTrial.gov / number: NCT03718312 on Oct.24.2018 URL number

Use of 3D Printing to Guide Creation of Fenestrations in Physician-Modified Stent-Grafts for Treatment of Thoracoabdominal Aortic Disease

Purpose: To summarize the experience and outcomes of total endovascular repair of thoracoabdominal aortic disease using 3-dimensional (3D) printed models to guide on-site creation of fenestrations in aortic stent-grafts. Materials and Methods: From April 2018 to March 2019, 34 patients (mean age 58±14 years; 24 men) with thoracoabdominal aortic disease were treated in our department. Nineteen patients had thoracoabdominal aortic dissection and 15 had thoracoabdominal aortic aneurysm. Preoperatively, a 3D printed model of the aorta was made according to computed tomography images. In the operating room, the main aortic stent-graft was completely released in the 3D printed model, and the position of each fenestration or branch was marked on the stent-graft. The fenestrations were then made using an electric pen. Wires were sewn to the edge of the fenestrations using nonabsorbable sutures. After customization, the aortic stent-graft was reloaded into the delivery sheath and deployed. Results: The printing process took ~5 hours (1 hour for image reconstruction, 3 hours for printing, and 1 hour for postprocessing). The physician-modified stent-grafts had a total of 107 fenestrations secured by 102 bridging stent-grafts, including 73 covered stents and 29 bare stents. The average procedure time was 5.6±1.2 hours, including a mean 1.3 hours for stent-graft customization. No renal insufficiency or paraplegia occurred. Two branch arteries were lost during the operation. One patient (3%) died 1 week after surgery from a retrograde dissection rupture. One patient developed a minor cerebral infarction postoperatively. The mean follow-up time was 8.5 months. There was 1 endoleak from a fenestration (coil embolized) and 4 distal ruptures of the aortic dissection (3 treated and 1 observed). Conclusion: Three-dimensional printing can be used to guide creation of fenestrated stent-grafts for the treatment of thoracoabdominal aortic diseases involving crucial branches. This technique appears to be more accurate than the traditional measurement method, with short-term follow-up demonstrating the safety and reliability of the method. However, further research and development are needed.

Mid-Term Outcomes of Complex Endografting for Chronic Post-Dissection Thoracoabdominal Aortic Aneurysms

PURPOSE

To report early and mid-term results of post-aortic dissection thoracoabdominal aneurysms (pD-TAAA) treated by complex endografting in three tertiary referral hospitals.

MATERIALS AND METHODS

A review of all patients with pD-TAAA unfit for open surgery treated with complex endovascular repair from 2012 to 2018 was performed. Simple thoracic endografts (TEVAR) were excluded. Staged procedures in case of extensive aortic coverage were always planned.

RESULTS

In total, 21 patients (16 males, mean age 63 ± 10 years) with pD-TAAA underwent aortic repair by fenestrated or branched thoracoabdominal endografts for visceral vessels. Mean TAAA diameter was 61 ± 6.2 mm. Spinal cord drainage was performed in all patients. A staged approach was used in 12 (57%) cases. Technical success was achieved in 18 (86%) patients. No in-hospital deaths occurred. Two patients experienced transient post-procedural spinal cord ischemia. At 30 days, six type II endoleaks (29%), two type Ic endoleak (9.5%) and one type IIIc endoleak (5%) were reported. At a mean follow-up of 23 ± 13 months, no late aortic-related deaths occurred. Three patients underwent reintervention for type Ic and IIIc endoleaks. No visceral vessel occlusion was observed. Estimated freedom from reintervention at 12 and 24 months was 85.7 ± 0.7%. In 13 cases, TAAA diameter decreased at least 5 mm, while increased > 5 mm in only one case. Complete false lumen thrombosis was achieved in 18 patients (86%).

CONCLUSION

Complex endografting for pD-TAAA showed favorable mid-term results. Staged and carefully planned endovascular procedures may represent a safe and effective therapeutic option in patients deemed at high risk of open repair.

Spinal Subdural Hematoma owing to the Removal of Cerebrospinal Fluid Drainage Tube During Thoracic Endovascular Aortic Repair

BACKGROUND

Cerebrospinal fluid (CSF) drainage during the treatment of aortic disease is commonly performed to prevent spinal cord ischemia. Spinal subdural hematoma (SDH) has never been reported after CSF drainage during thoracic endovascular aortic repair (TEVAR). We present a case of concurrent intracranial subarachnoid hemorrhage (SAH) and spinal SDH after CSF drainage tube removal in a patient with TEVAR.

CASE DESCRIPTION

A 73-year-old man was hospitalized to undergo TEVAR. The day before the procedure, a lumbar CSF drainage tube was inserted. Continuous CSF drainage was performed only during the procedure, and the tube was removed the following day. The patient complained of mild back pain on postoperative day 2; headache, bilateral lower limb paresis, and bladder and rectal disturbances developed on postoperative day 5. Brain and spinal magnetic resonance imaging revealed spinal subdural or subarachnoid hematoma and intracranial SAH. Lumbar laminectomies for spinal SDH removal were performed; lower limb strength improved immediately after surgery. At postoperative 2 years, the patient returned to his preoperative activity level; only mild right lower limb numbness persisted.

CONCLUSIONS

We present a rare case of intracranial SAH and spinal SDH that developed after CSF drainage tube removal in a patient with TEVAR. CSF drainage should be carefully considered in patients undergoing aortic procedures, as SAH and spinal SDH may occur in addition to spinal cord ischemia.

Left Atrial to Femoral Artery Full Cardiopulmonary Bypass: A Novel Technique for Descending and Thoracoabdominal Aortic Surgery

Left atrial-femoral artery (LA-FA) bypass with a centrifugal pump and no oxygenator is commonly used for descending and thoracoabdominal aortic (DTAA) operations, mitigating the deleterious effects of cross-clamping. We present our initial experience performing DTAA replacement under LA-FA (left-to-left) cardiopulmonary bypass (CPB) with an oxygenator. DTAA replacement under LA-FA bypass with an oxygenator was performed in 14 consecutive patients (CPB group). The pulmonary vein and femoral artery (or distal aorta) were cannulated and the full CPB machine were used, including oxygenator, roller pump, pump suckers, and kinetically enhanced drainage. The CPB group was compared with 50 consecutive patients who underwent DTAA replacement utilizing traditional LA-FA bypass without an oxygenator (LA-FA group). Perioperative data were collected and statistical analyses were performed. All CPB patients maintained superb cardiopulmonary stability. The pump sucker permitted immediate salvage and return of shed blood. Superb oxygenation was maintained at all times. High-dose full CPB heparin was reversed without difficulty. The CPB group required markedly fewer blood transfusions than the LA-FA group (2.21 vs. 5.88 units, p  < 0.004). The 30-day mortality rate was 7.1% ( n  = 1) and there were no paraplegia cases in the CPB group versus 7 (14%) deaths and 3 (6%) paraplegia cases in the LA-FA group. Traditional LA-FA bypass without an oxygenator avoids high-dose heparin. In the present era, heparin reversal is more secure. Our experience finds that the novel application of LA-FA CPB with an oxygenator is safe and suggests improved hemodynamics (immediate return of shed blood) and a hemostatic advantage (avoidance of loss of coagulation factors in the cell saver).

Spinal Subarachnoid Hematoma After Cerebrospinal Fluid Drainage in Thoracoabdominal Aortic Aneurysm Repair: Case Report and Literature Review

BACKGROUND

Cerebrospinal fluid (CSF) drainage reduces the risk of paraplegia in thoracoabdominal aortic aneurysm (TAAA) repair. Intracranial hemorrhage after TAAA repair has been reported as a rare complication of CSF drainage; however, spinal subarachnoid hematoma has never been reported. Here, we present a case of lumbosacral subarachnoid hematoma after CSF drainage in TAAA repair.

CASE DESCRIPTION

The patient was a 76-year-old man who was hospitalized for TAAA repair. Just before the operation, a CSF drainage catheter was inserted into the L4/5 vertebral interspace. Continuous CSF drainage was performed during the operation. The CSF drain was clamped just after the operation, and the drainage catheters were removed at 24 hours after the operation. On postoperative day 1, the patient experienced pain and paralysis in both lower limbs that worsened over time. Magnetic resonance imaging of the brain and spinal cord was indicative of a spinal subarachnoid hematoma. Removal of hematoma with thoracolumbar and lumbosacral laminectomy was performed, and immediately after the surgery, the pain and paralysis in both lower limbs improved. Six months after the removal of the hematoma, the paralysis in both lower limbs completely resolved and the patient achieved the preinjury activity level.

CONCLUSIONS

We present a rare case of lumbosacral subarachnoid hematoma after CSF drainage in TAAA repair. We should consider spinal subarachnoid hematoma when paralysis in the lower limbs occurs after CSF drainage.

Assessment of Spinal Cord Ischemia With Near-Infrared Spectroscopy: Myth or Reality?

Non-invasive near-infrared spectroscopy is gaining popularity in the detection of spinal cord ischemia following aortic aneurysm repair. However, practical recommendations are lacking. This review focuses on the physiological and anatomical background, as well as on the clinical implementations of near-infrared spectroscopy as a tool for monitoring ischemia of the spinal cord. Clinical recommendations based on the currently available evidence are rendered.

Late-Onset Paraplegia After Endovascular Repair of Type B Aortic Dissection Managed by Urgent Left Subclavian Artery Revascularization: A Case Report

Spinal cord ischemia is one of the most unpredictable and feared complications after open surgical or endovascular thoracic aortic repair. Protection of collateral network branches that contribute blood supply to spinal cord is fundamental in the prevention of this catastrophic condition. We report the case of a patient who underwent emergent endovascular treatment for a type B aortic dissection complicated by rupture of the false lumen, with intentional coverage of the left subclavian artery without revascularization. The patient developed paraplegia on the 10th postoperative day, which did not significantly improve with immediate cerebrospinal fluid drainage but fully recovered after urgent left carotid-subclavian bypass.

Comparison of early patency rate and long-term outcomes of various techniques for reconstruction of segmental arteries during thoracoabdominal aortic aneurysm repair

OBJECTIVES

This study aimed to analyse the early patency rate and long-term outcomes of reattached segmental intercostal arteries using graft interposition, single-cuff anastomosis or island reconstruction.

METHODS

We selected 172 consecutive patients who underwent open surgery for the thoracoabdominal aorta with reattachment of segmental arteries between October 1999 and March 2018. The early patency of segmental arteries was analysed using enhanced computed tomography. Segmental arteries were reconstructed using graft interposition (n = 111), single-cuff anastomosis (n = 38) or island reconstruction (n = 23).

RESULTS

The hospital mortality was 6.4%. Twenty patients developed spinal cord ischaemic injury (permanent, n = 12 or transient, n = 8). Spinal cord injury was found in 16, 3 and 1 patients in the graft interposition, single-cuff anastomosis and island reconstruction groups, respectively. Overall, 475 segmental arteries were reattached (mean number per patient 2.8 ± 1.3). The overall early patency rate was 63.4%. The patency rates in island reconstruction (91.2%) and single-cuff anastomosis (77.1%) were significantly better than that in graft interposition (54.0%; P < 0.01). However, 6 patients with island reconstruction of segmental arteries had an aneurysm formation at the intercostal artery reconstruction site, of whom 4 patients underwent reoperation during follow-up. None of the patients with graft interposition or single-cuff reattachment had a patch aneurysm in segmental arteries.

CONCLUSIONS

Island reconstruction and single-cuff anastomosis might offer better patency rates and prevent spinal cord ischaemic injury than graft interposition. Because some patients with island reconstruction required reoperation for patch aneurysms in segmental arteries, single-cuff anastomosis is preferable in terms of early- and long-term outcomes.

Thoracoabdominal Aortic Aneurysm Repair: What Should the Anaesthetist Know?

The surgical repair of descending thoracic aortic (DTA) and thoracoabdominal aortic aneurysms (TAAAs) presents one of the greatest challenges for anaesthesiologists. The challenge comes from the fine balance of complex medical issues in the setting of altered physiology that occurs during the perioperative period. Patients presenting for TAAA repair usually have multiple pre-existing comorbid conditions involving their cardiac, pulmonary and renal systems; and aneurysm repair poses a direct and immediate threat to these systems in addition to that to the gastrointestinal and neurologic systems. Operative mortality in thoracoabdominal aortic surgery is quite high to the extent of 5%-12% with a 5-year survival rate of 70%-79% for DTA aneurysm and 59% for thoracoabdominal aortic aneurysm surgeries. Complex haemodynamic changes associated with the clamping and declamping of aorta requires thorough knowledge and expertise for the management of TAAA. We present a brief review on the anaesthetic management and possible complications that anaesthetists should be aware of during TAAA repair.

Association between false lumen segmental arteries and spinal cord ischemia in type A acute aortic dissection

BACKGROUND

Spinal cord ischemia (SCI) and paraplegia are complications of surgery for type A acute aortic dissection (TAAAD). Since the segmental arteries play a key role in SCI, this study evaluated the association between SCI and false lumen segmental arteries (FLSAs: segmental arteries originating from the false lumen).

METHODS

The study included 101 consecutive TAAAD patients (mean age, 66±13; range, 34-89 years) who underwent surgery from January 2011 to April 2017. The diagnosis of TAAAD and the number of FSLAs were determined by preoperative computed tomography (CT). Patients were divided into two groups according to the number of FLSAs at the Th9-L2 level: Group A (N.=13), ≥8 FLSAs; and group B (N.=88), ≤7 FLSAs. Preoperative, perioperative, and postoperative findings were compared between the groups, and risk factors for SCI were evaluated.

RESULTS

The frequency of preoperative paralysis was significantly higher in Group A than Group B (P=.0070). The overall incidence of postoperative SCI was 8% (8/101) and significantly higher in Group A than Group B (5/13 [45%] vs. 3/88 (4%), P<0.0001). Hospital mortality was 8% (8/101) and significantly higher in Group A than Group B (3/13 [23%] vs. 5/88 [6%], P=.0302). Multivariate analysis showed that the independent risk factors for SCI were ≥8 FLSAs at Th9-L2 (odds ratio [OR], 20.4; 95% confidence interval [95% CI], 3.34-124.9, P=0.0011) and diabetes mellitus (OR, 22.3; 95% CI, 1.69-294.5; P=0.0184).

CONCLUSIONS

In patients who underwent surgery for TAAAD, ≥8 FLSAs at the Th9-L2 levels on preoperative CT was a risk factor for SCI.

Open Replacement of the Thoracoabdominal Aorta: Short- and Long-term Outcomes at a Single Institution

Background  Despite much progress in the surgical and endovascular treatment of thoracoabdominal aortic diseases (TAADs), there is no consensus regarding the optimal approach to minimize operative mortality and end-organ dysfunction. We report our experience in the past 16 years treating TAAD by open surgery. Methods  A retrospective review of all TAAD patients who underwent an open repair since January 2000 was performed. The primary endpoints included early morbidity and mortality, and the secondary endpoints were overall death and rate of aortic reintervention. Results  There were 112 patients treated by open surgery for TAAD. Mean age was 66 ± 10 years and 61 (54%) were male. Seventy-seven (69%) patients had aneurysmal degeneration without aortic dissection and the remaining 35 (31%) had a concomitant aortic dissection. There were 12 deaths (10.7%) and they were equally distributed between the aneurysm and dissection groups ( p  = 0.8). The mortality for elective surgery was 3.2% (2/61). The rate of permanent paraplegia and stroke were each 2.6% (3/112). The rate of cerebrovascular accident was significantly higher in the dissection group (8.5% vs. 1.2%, p  = 0.05). The survival at 1, 5, and 10 years was 80.6, 56.1, and 32.7%, respectively. Conclusion  Our data confirm that open replacement of the thoracoabdominal aorta can be performed in expert centers quite safely. Different aortic pathologies (degenerative aneurysm vs. dissection) do not influence the short- and long-term outcomes. Open surgery should still be considered the standard in the management of TAAD.

Protection from spinal cord ischemia-reperfusion damage with alpha-lipoic acid preconditioning in an animal model

Background

This study aims to investigate whether preconditioning with alpha-lipoic acid has any protective effect in neuronal damage in an experimental spinal cord ischemia-reperfusion injury model.

Methods

Eighteen adult male New Zealand rabbits (2.4-3.5 kg) were equally divided into sham, control and treatment groups. The abdominal aorta was occluded for 30 min proximally 1 cm below the renal artery and distally 1 cm above the bifurcation using aneurysm clips in control and treatment groups. Treatment group received intraperitoneal 100 mg/kg lipoic acid 20 min before aortic cross-clamping. The animals were sacrificed 48 hours after the operation and spinal cord segments between L2 and L5 were removed for biochemical and histopathological analysis. Levels of glutathione, malondialdehyde, total nitrate/nitrite, advanced oxidation protein products, catalase, superoxide dismutase, and glutathione peroxidase were examined in spinal cord.

Results

Preconditioning with alpha-lipoic acid demonstrated significantly favorable effects in all measured parameters of oxidative stress. Histopathological evaluation of the tissues also demonstrated significantly decreased neuronal degeneration, axonal damage, and microglial and astrocytic infiltration in the treatment group compared to the control group.

Conclusion

The results of this study indicate that alpha-lipoic acid administration before aortic cross-clamping has significant neuroprotective effect on spinal cord injury in rabbits.