Multidisciplinary Approach to Prevent Spinal Cord Ischemia After Thoracic Endovascular Aneurysm Repair for Distal Descending Aorta

Outcomes of thoracic endovascular aortic repair for complicated type B acute aortic dissection from a multicenter Japanese post-market surveillance study

OBJECTIVES

A primary goal of thoracic endovascular aortic repair (TEVAR) for type B acute aortic dissection (BAAD) is exclusion of the primary entry tear with a suitable stent graft (SG) to reestablish true lumen flow and promote aortic remodeling. This study aimed to determine the safety and efficacy of a conformable thoracic SG in a Japanese population with complicated BAAD.

METHODS

Between 2016 and 2017, 43 patients with complicated BAAD were enrolled in this prospective, nonrandomized, multicenter post-market surveillance study at 27 sites in Japan. All patients underwent TEVAR using the Gore TAG Conformable Thoracic Endoprosthesis (CTAG) (W.L. Gore and Associates, Flagstaff, AZ).

RESULTS

The most common TEVAR indication for complicated BAAD was malperfusion (41.9%; 24 out of 43) and aortic rupture was observed in 32.5% of patients (14 out of 43). All SG implants were successfully completed and there was no patient with surgical conversion. Thirty-day mortality was 7.0% (3 out of 43) and one patient (2.3%) experienced spinal cord ischemia during hospitalization. Entry tear exclusion was achieved in 91.3% of patients at 1 month, and 95.7% at 24 months. Through 24 months after TEVAR, no retrograde type A aortic dissection was observed and distal stent graft induced new entry was observed in two patients (4.7%).

CONCLUSION

TEVAR utilizing the CTAG device for complicated BAAD in Japan demonstrated a low incidence of perioperative mortality and complications. Complications directly attributed to the SG including RTAD and dSINE were uncommon and the midterm outcomes were deemed satisfactory.

Angio Cone-Beam CT (Angio-CBCT) and 3D Road-Mapping for the Detection of Spinal Cord Vascularization in Patients Requiring Treatment for a Thoracic Aortic Lesion: A Feasibility Study

BACKGROUND

Spinal cord ischemia is a major complication of treatment for descending thoracic aorta (DTA) disease. Our objectives were (1) to describe the value of angiographic cone-beam CT (angio-CBCT) and 3D road-mapping to visualize the Adamkiewicz artery (AA) and its feeding artery and (2) to evaluate the impact of AA localization on the patient surgical strategy.

METHODS

Between 2018 and 2020, all patients referred to our institution for a surgical DTA disorder underwent a dedicated AA evaluation by angio-CBCT. If the AA feeding artery was not depicted on angio-CBCT, selective artery catheterization was performed, guided by 3D road-mapping. Intervention modifications, based on AA location and one month of neurologic follow-up after surgery, were recorded.

RESULTS

Twenty-one patients were enrolled. AA was assessable in 100% of patients and in 15 (71%) with angio-CBCT alone. Among them, 10 patients needed 3D road-mapping-guided DSA angiography to visualize the AA feeding artery. The amount of contrast media, irradiation dose, and intervention length were not significantly different whether the AA was assessable or not by angio-CBCT. AA feeding artery localization led to surgical sketch modification for 11 patients.

CONCLUSIONS

Angio-CBCT is an efficient method for AA localization in the surgical planning of DTA disorders.

Systematic review and meta-analysis of association of prophylactic cerebrospinal fluid drainage in preventing spinal cord ischemia after thoracic endovascular aortic repair

OBJECTIVE

We conducted a systemic review and meta-analysis to compare the association between prophylactic cerebrospinal fluid drainage (CSFD) vs non-CSFD in preventing spinal cord ischemia (SCI) after thoracic endovascular aortic repair (TEVAR) for aneurysm and dissection.

METHODS

The MEDLINE, Embase, and Cochrane databases were systematically searched to identify all relevant studies reported before April 1, 2020. A systematic review and meta-analysis were performed. We assessed the association between CSFD strategies, including routine CSFD vs selective CSFD or no CSFD, and the SCI rates after TEVAR for patients with aortic dissection (AD), solitary thoracic aortic aneurysm (TAA), or thoracoabdominal aortic aneurysm (TAAA). Subgroup analyses were conducted to assess the association between different aortic pathologies, including AD and thoracic aneurysms, and SCI rates after TEVAR with and without prophylactic CSFD. The data are presented as the pooled event rates (ERs) and 95% confidence intervals (CIs).

RESULTS

A total of 34 studies of 3561 patients (2671 with TAA or TAAA and 890 with type B AD) were included in the present analysis. The data are presented as the pooled ERs and 95% CIs. The overall SCI rate for patients who had undergone TEVAR with prophylactic CSFD for AD (ER, 1.80%; 95% CI, 0.88%-2.72%) was significantly lower than that for the aortic aneurysm group (ER, 5.73%; 95% CI, 4.20%-7.27%; P < .0001). The SCI rate after TEVAR with prophylactic CSFD was not significantly different from that without CSFD for AD (P = .51). No association was found between the rates of SCI after TEVAR with routine prophylactic CSFD vs selective prophylactic CSFD for aortic aneurysms (P = .76) and AD (P = .70). The SCI rate after TEVAR without CSFD for aortic aneurysms, including isolated TAA and TAAA (ER, 3.49%; 95% CI, 0.23%-6.76%) was not significantly different from that for AD (ER, 3.20%; 95% CI, 0.00%-7.20%; P = .91). For the patients with TAAAs, the rate of SCI after TEVAR with routine prophylactic CSFD was significantly lower than that with selective prophylactic CSFD (P = .04).

CONCLUSIONS

Our systematic review and meta-analysis has shown that SCI occurs more often after TEVAR for aortic aneurysms than for AD. Routine prophylactic CSFD, compared with selective CSFD, was associated with a lower rate of postoperative SCI after TEVAR for TAAAs. No significant association was found between the SCI rate and routine prophylactic CSFD for patients undergoing TEVAR for isolated TAA or AD.

Severe intraluminal atheroma and iliac artery access affect spinal cord ischemia after thoracic endovascular aortic repair for degenerative descending aortic aneurysm

OBJECTIVES

This study aimed to reveal additional factors potentially contributing to the multifactorial ethiopathogenesis of spinal cord ischemia (SCI) after thoracic endovascular aortic repair (TEVAR) for descending thoracic aortic aneurysm (TAA).

METHODS

The medical records of 293 patients who underwent TEVAR without debranching procedures for descending TAA between 2011 and 2018 were retrospectively reviewed. We excluded the following cases from the study: 72 patients with aortic dissection; 15 with rupture; 14 with anastomotic pseudoaneurysm; 22 with re-TEVAR; 34 without evaluation of the artery of Adamkiewicz (AKA). Sufficient data were available for 136 patients (79% men; mean age of 76 ± 7.4 years). We conducted univariable and multivariable analyzes using the logistic regression analysis to assess the relationship between pre-/intraoperative factors and postoperative SCI.

RESULTS

SCI was observed in nine patients (6.8%). Severe intraluminal atheroma [odds ratio (OR), 6.23; p = 0.014] and iliac artery access (OR 4.65; p = 0.043) were identified as the positive predictors of SCI by univariable analysis. Risk factors of SCI were determined additionally as follows: coverage of the intercostal artery branching AKA (ICA-AKA) (OR 4.89; p = 0.054); coverage of the ICA-AKA combined with iliac access (OR 10.1; p = 0.002); that combined with severe intraluminal atheroma (OR 13.7; p = 0.001).

CONCLUSION

Severe intraluminal atheroma and iliac artery access were the independent predicting factors of SCI after TEVAR for degenerative descending TAA. In patients with complicated aortoiliofemoral access route, coverage of the ICA-AKA is associated with the risk of SCI.

Extended thoracic endovascular aortic repair for residual aortic dissection after type A aortic dissection repair

OBJECTIVE

We investigated the outcomes of extended coverage of the descending thoracic aorta by thoracic endovascular aortic repair (TEVAR) for residual chronic type B aortic dissection after type A aortic dissection (TAAD) repair.

METHODS

From November 2015 to August 2020, 36 patients underwent extended TEVAR for residual intimal tear after TAAD repair. We specifically investigated the methods and outcomes of this procedure.

RESULTS

TEVAR consisted of isolated TEVARs (n = 29), single-vessel debranching TEVAR (6), and two-vessel debranching TEVAR (1). The mean time from TAAD repair to TEVAR was 27 ± 33 months (2-86 months). The TEVAR devices used were Valiant (28 cases), GORETAG (4), Relay plus (2), and TX2 (2). Technical success of TEVAR was 100%. The distal ends of the stent grafts were T 8 (1 case), T 9 (5), T 10 (6), T 11 (9), and T 12 (15), with an average of T 11 ± 1. The average length of hospital stay after TEVAR was 9 ± 3 days (5-17 days). There were no surgical/hospital deaths or complications. The average postoperative follow-up period was 21 ± 15 months without death or reintervention.

CONCLUSIONS

The short-term outcomes of extended TEVAR for residual chronic type B aortic dissection after TAAD repair were acceptable without perioperative SCI. Aggressive descending thoracic aorta coverage may prevent aortic events, and extended TEVAR may be a preemptive treatment for the downstream aorta. Mid- to long-term results should be clarified.

Implementation of a treatment algorithm to decrease incidence of paralysis post endovascular thoracoabdominal aorta repair

BACKGROUND

Spinal cord ischemia (SCI) is a rare but devastating complication following aortic repair. Despite improvements in operative management and critical care of aortic disease patients, SCI remains one of the most serious and common complications after these procedures. Early recognition and rescue interventions can augment the outcome and reduce the morbidity or avoid permanent dysfunction. This is a single institution experience of creating an evidence-based algorithm for the treatment of SCI in patients after thoracoabdominal endovascular aortic repair (TEVAR).

INTERVENTION/METHODS

We implemented an evidence-based treatment algorithm for the management of acute SCI after TEVAR. A total of 131 TEVAR cases were reviewed, 59 cases preimplementation, and 72 cases postimplementation of an SCI treatment algorithm.

RESULTS

Lower extremity motor and/or sensory deficits were identified in 5.1% of preimplementation and 4.2% of postimplementation cases. SCI treatment interventions included increasing the mean arterial pressure (MAP) (66% pre and 100% post), placing lumbar drain (33% pre and 33% post), performing carotid subclavian bypass (33% pre and 33% post), initiating naloxone drip (66% pre and 100% post), and administering glipizide (0% pre and 100% post, P < .05). Long-term paralysis occurred in 66% of preimplementation and 0% of postimplementation cases.

CONCLUSIONS

By creating and implementing an SCI treatment algorithm we reduced both, time to detection and time to effective treatment of SCI and significantly improved our patients' neurological outcomes.

Complications associated with lumbar drain placement for endovascular aortic repair

OBJECTIVE

We reviewed the complications associated with perioperative lumbar drain (LD) placement for endovascular aortic repair.

METHODS

Patients who had undergone perioperative LD placement for endovascular repair of thoracic and thoracoabdominal aortic pathologies from 2010 to 2019 were reviewed. The primary endpoints were major and minor LD-associated complications. Complications that had resulted in neurological sequelae or had required an intervention or a delay in operation were defined as major. These included intracranial hemorrhage, symptomatic spinal hematoma, cerebrospinal fluid (CSF) leak requiring intervention, meningitis, retained catheter tip, arachnoiditis, and traumatic (or bloody) tap resulting in delayed operation. Minor complications were defined as a bloody tap without a delay in surgery, asymptomatic epidural hematoma, and CSF leak with no intervention required. Isolated headaches were recorded separately owing to the minimal clinical impact.

RESULTS

A total of 309 LDs had been placed in 268 consecutive patients for 222 thoracic endovascular aortic repairs, 85 complex endovascular aortic repairs (EVARs; fenestrated branched EVAR/parallel grafting), and 2 EVARs (age, 65 ± 13 years; 71% male) for aortic pathology, including aneurysm (47%), dissection (49%), penetrating aortic ulcer (3%), and traumatic injury (0.6%). A dedicated neurosurgical team performed all LD procedures; most were performed by the same individual, with a technical success rate of 98%. Radiologic guidance was required in 3%. The reasons for unsuccessful placement were body habitus (n = 2) and severe spinal disease (n = 3). Most were placed prophylactically (96%). The overall complication rate was 8.1% (4.2% major and 3.9% minor). Major complications included spinal hematoma with paraplegia in 1 patient, intracranial hemorrhage in 2, meningitis in 2, arachnoiditis in 3, CSF leak requiring a blood patch in 3, bloody tap delaying the operation in 1, and a retained catheter tip in 1 patient. Patients who had undergone previous LD placement had experienced significantly more major LD-related complications (12.2% vs 3%; P = .019). The rate of total LD-associated complications did not differ between prophylactic and emergent therapeutic placements (8.1% vs 7.7%; P = 1.00) nor between major or minor complications. On multivariate analysis, previous LD placement and an overweight body mass index were the only independent predictors of major LD-related complications.

CONCLUSIONS

The complications associated with LD placement can be severe even when performed by a dedicated team. Previous LD placement and overweight body mass index were associated with a significantly greater risk of complications; however, emergent therapeutic placement was not. Although these risks are justified for therapeutic LD placement, the benefit of prophylactic LD placement to prevent paraplegia should be weighed against these serious complications.

New Preoperative Spinal Cord Ischemia Risk Stratification Model for Patients Undergoing Thoracic Endovascular Aortic Repair

PURPOSE

Our objective was to determine significant predictors of spinal cord ischemia (SCI) following Thoracic Endovascular Aortic Repair (TEVAR) and to further develop a simple and clinically orientated risk score model.

METHODS

A retrospective review of data from the Society of Vascular Surgery/Vascular Quality Initiative national data set was performed for all patients undergoing TEVAR from January, 2014 to June 2018. Preoperative demographics, procedure-related variables, and clinical details related to SCI were examined. A SCI risk score was developed utilizing a multivariable logistic regression model.

RESULTS

For the 7889 patients in the final analysis who underwent TEVAR during the study period, the mean age was 67.6 ± 13.9, range 18 to 90 years, and the majority was male (65%). Postoperative outcomes included stroke (3.0%), myocardial infarction (2.9%), inhospital mortality (5.4%), transient SCI (1.5%), and permanent SCI (2.1%). Nearly half of the overall cases were performed in high volume centers. Predictors of increased risk for SCI included age by decade (odds ratio [OR]: 1.2), celiac coverage (OR: 1.5), current smoker (OR: 1.6), dialysis (OR: 1.9), 3 or more aortic implanted devices (OR: 1.7), emergent or urgent surgery (OR: 1.5), adjunct aorta-related procedure (OR: 2.5), adjunct not related (OR: 2.6), total estimated length of aortic device (19-31 cm, OR: 1.9 and ≥32 cm, OR: 3.0), ASA class 4 or 5 (OR: 1.6), and procedure time ≥154 minutes (OR: 1.8). Two predictors decreased the risk of SCI, cases from high-volume centers (OR: 0.6) and eGFR ≥ 60 (OR: 0.6). To evaluate the risk score model, probabilities of SCI from the original regression, raw score, and raw score categories resulted in area under the curve statistics of 0.792, 0.786, and 0.738, respectively.

CONCLUSIONS

Spinal cord ischemia remains one of the most feared complications of TEVAR. Incidence of SCI in this large series of patients with TEVAR was 3.6% with nearly 60% being permanent. The proposed model provides an assessment tool to guide clinical decisions, patient consent process, risk-assessment, and procedural strategy.

The Safety and Efficacy of Extended TEVAR in Acute Type B Aortic Dissection

BACKGROUND

Thoracic endovascular aortic repair (TEVAR) with endograft coverage from the left subclavian artery to the celiac artery has been hypothesized to increase spinal cord ischemia. This study analyzes the impact of extended coverage on adverse outcomes and aortic remodeling in patients with complicated acute type B aortic dissection (aTBAD).

METHODS

From January 2012 to October 2018, 91 patients underwent TEVAR for aTBAD. Median follow-up was 3.1 (interquartile range, 1.2-4.9) years and was complete in 94% of patients. The extent of aortic endograft coverage was categorized as standard (n = 39) or extended (n = 52). Contrast-enhanced imaging scans were analyzed to determine length of coverage, maximum aortic diameters, and false lumen (FL) status.

RESULTS

The mean age was 52.6 ± 13.9 years, and 66% were men. The most common indications for intervention were malperfusion (42%) and refractory pain (34%). Thirteen (14%) patients required a lumbar drain (preoperative: n = 3; postoperative: n = 10). Mean duration between scans was 2.0 ± 1.9 years. Length of aortic coverage was significantly longer in the extended group (241.7 ± 29.2 mm vs 180.8 ± 22.3 mm in the standard group; P < .001). In-hospital and overall mortality were 6% and 11%, respectively. There were no cases of paraplegia, and the incidence of spinal cord ischemia was 3%. After TEVAR, there was a higher incidence of FL obliteration or thrombosis at the distal descending thoracic aorta in the extended group (53% vs 16% in the standard group; P = .004).

CONCLUSIONS

Extended TEVAR carries a low risk of spinal cord ischemia and improves FL remodeling of the descending thoracic aorta in patients with aTBAD. This strategy may decrease the need for reinterventions on the thoracic aorta in the chronic phase of TBAD.

Artery of Adamkiewicz: a meta-analysis of anatomical characteristics

PURPOSE

The artery of Adamkiewicz (AKA) provides the major blood supply to the anterior thoracolumbar spinal cord and iatrogenic injury or inadequate reconstruction of this vessel during vascular and endovascular surgery can result in postoperative neurological deficit due to spinal cord ischemia. The aim of this study was to provide comprehensive data on the prevalence and anatomical characteristics of the AKA.

METHODS

An extensive search was conducted through the major electronic databases to identify eligible articles. Data extracted included study type, prevalence of the AKA, gender, number of AKA per patient, laterality, origin based on vertebral level, side of origin, morphometric data, and ethnicity subgroups.

RESULTS

A total of 60 studies (n = 5437 subjects) were included in the meta-analysis. Our main findings revealed that the AKA was present in 84.6% of the population, and patients most frequently had a single AKA (87.4%) on the left side (76.6%) originating between T8 and L1 (89%).

CONCLUSION

As an AKA is present in the majority of the population, caution should be taken during vascular and endovascular surgical procedures to avoid injury or ensure proper reconstruction. All surgeons operating in the thoracolumbar spinal cord should have a thorough understanding of the anatomical characteristics and surgical implications of an AKA.

Endovascular management of an aortic rupture following transcatheter aortic valve replacement

We report a case of aortic rupture during transcatheter aortic valve replacement (TAVR) managed successfully by urgent stent-graft implantation.

Cerebrospinal fluid drains reduce risk of spinal cord injury for thoracic/thoracoabdominal aneurysm surgery: A review

Background

The risk of spinal cord injury (SCI) due to decreased cord perfusion following thoracic/thoracoabdominal aneurysm surgery (T/TL-AAA) and thoracic endovascular aneurysm repair (TEVAR) ranges up to 20%. For decades, therefore, many vascular surgeons have utilized cerebrospinal fluid drainage (CSFD) to decrease intraspinal pressure and increase blood flow to the spinal cord, thus reducing the risk of SCI/ischemia.

Methods

Multiple studies previously recommend utilizing CSFD following T/TL-AAA/TEVAR surgery to treat SCI by increasing spinal cord blood flow. Now, however, CSFD (keeping lumbar pressures at 5-12 mmHg) is largely utilized prophylactically/preoperatively to avert SCI along with other modalities; avoiding hypotension (mean arterial pressures >80-90 mmHG), inducing hypothermia, utilizing left heart bypass, and employing intraoperative neural monitoring [somatosensory (SEP) or motor evoked (MEP) potentials]. In addition, preoperative magnetic resonance angiography (MRA) and computed tomographic angiography (CTA) scans identify the artery of Adamkiewicz to determine its location, and when/whether reimplantation/reattachment of this critical artery and or other major segmental/lumbar arterial feeders are warranted.

Results

Utilizing CSFD for 15-72 postoperative hours in T/TL-AAA/TEVAR surgery has reduced the risks of SCI from a maximum of 20% to a minimum of 2.3%. The major complications of CSFD include; spinal and cranial epidural/subdural hematomas, VI nerve palsies, retained catheters, meningitis/infection, and spinal headaches.

Conclusions

By increasing blood flow to the spinal cord during/after T/TL-AAA/TEVAR surgery, CSFD reduces the incidence of permanent SCI from, up to 10-20% down to down to 2.3-10%. Nevertheless, major complications, including spinal/cranial subdural hematomas, still occur.

Complications and Perioperative Management of Patients Undergoing Thoracic Endovascular Aortic Repair

Endovascular treatments have become increasingly common for patients with a variety of thoracic aortic pathologies. Although considered less invasive than traditional open surgical approaches, they are nonetheless complex procedures. Patients undergo manipulation of an often calcified aorta near the origin of the carotid and subclavian vessels and have stents placed in a curved vessel adjacent to a perpetually beating heart. These stents can obstruct blood flow to the spinal cord, induce an inflammatory response, and in rare cases erode into the adjacent trachea or esophagus. Renal complications range from contrast-induced nephropathy to hypotension and ischemia to dissection. Emboli can lead to strokes and mesenteric ischemia. These patients have complex medical histories, and skilled perioperative management is critical to achieving the best clinical outcomes. Here, we review the medical management of the most common complications in these patients including stroke, spinal cord ischemia, renal injury, retrograde dissections, aortoesophageal and aortobronchial fistulas, postimplantation syndrome, mesenteric ischemia, and endograft failure.

Effects of preemptive cerebrospinal fluid drainage on spinal cord protection during thoracic endovascular aortic repair

BACKGROUND

Spinal cord injury (SCI) is reported to occur in 3-12% of thoracic endovascular aortic repair (TEVAR) cases, but is a potentially preventable complication of TEVAR for thoracoabdominal pathologies. Although many strategies have been devised to reduce the incidence of SCI, the effectiveness of prophylactic cerebrospinal fluid drainage (CSFD) and left subclavian artery (LSA) revascularization remains controversial.

METHODS

From 2012 to 2014, 162 patients underwent TEVAR at a single institution. We prospectively collected and retrospectively reviewed the data of 81 patients who underwent preoperative CSFD among the 162 patients. LSA revascularization was routinely used when LSA need to be covered. Preoperative characteristics, intraoperative variables, and outcomes were analyzed.

RESULTS

The mean (SD) age of the patients was 60.6 (12.5) years, and 57 patients (70%) were male. Twenty-five patients (31%) presented with degenerative aneurysm; 48 (59%), type B dissection; 5, (6%) penetrating aortic ulcer; and 3 (4%), intramural hematoma. Thirty-six patients (44%) underwent LSA revascularization before TEVAR. Two (2.5%) of the patients who underwent preoperative CSFD had SCI, of whom one recovered ambulatory status at discharge after hypertensive therapy and another had a permanent disability. Prior abdominal aortic aneurysm (AAA) repair tended to relate to SCI (P=0.065), and preoperative aortic rupture was a significant independent risk factor of SCI (P=0.002).

CONCLUSIONS

Preemptive CSFD as an adjunctive procedure to TEVAR proved to be more effective than selective use of CSFD in other prior reports of SCI cases. Preoperative CSFD is recommended as a prophylactic procedure in patients at high risk of SCI during TEVAR.

3D Image Fusion to Localise Intercostal Arteries During TEVAR

Purpose

Preservation of intercostal arteries during thoracic aortic procedures reduces the risk of post-operative paraparesis. The origins of the intercostal arteries are visible on pre-operative computed tomography angiography (CTA), but rarely on intra-operative angiography. The purpose of this report is to suggest an image fusion technique for intra-operative localisation of the intercostal arteries during thoracic endovascular repair (TEVAR).

Technique

The ostia of the intercostal arteries are identified and manually marked with rings on the pre-operative CTA. The optimal distal landing site in the descending aorta is determined and marked, allowing enough length for an adequate seal and attachment without covering more intercostal arteries than necessary. After 3D/3D fusion of the pre-operative CTA with an intra-operative cone-beam CT (CBCT), the markings are overlaid on the live fluoroscopy screen for guidance. The accuracy of the overlay is confirmed with digital subtraction angiography (DSA) and the overlay is adjusted when needed. Stent graft deployment is guided by the markings. The initial experience of this technique in seven patients is presented.

Results

3D image fusion was feasible in all cases. Follow-up CTA after 1 month revealed that all intercostal arteries planned for preservation, were patent. None of the patients developed signs of spinal cord ischaemia.

Conclusion

3D image fusion can be used to localise the intercostal arteries during TEVAR. This may preserve some intercostal arteries and reduce the risk of post-operative spinal cord ischaemia.

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3D image fusion is feasible for intra-operative guidance during TEVAR.

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Fusion technique allows intra-operative visualization of intercostal artery origins.

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3D image fusion can help preservation of intercostal artery patency, known to be important in reducing the risk of spinal cord ischemia.

Electrophysiological monitoring during preoperative angiography to guide decisions regarding permanent occlusion of major radicular arteries in patients undergoing total en bloc spondylectomy

OBJECTIVE

Preoperative embolization is performed before spine tumor surgery when significant intraoperative hemorrhage is anticipated. Occlusion of radicular and segmental arteries may result in spinal ischemia. The goal of this study was to check whether neurophysiological monitoring during preoperative angiography in patients scheduled for total en bloc spondylectomy (TES) of spine tumors improves the safety of vessel occlusion.

METHODS

This was a case series study of patients who underwent tumor embolization under somatosensory evoked potential (SSEP) and motor evoked potential (MEP) monitoring in preparation for TES in treating spine tumors. The angiography findings, the embolized vessels, and the results are presented.

RESULTS

Five patients whose ages ranged from 33 to 75 years and who had thoracic spine tumors are reported. Four patients suffered from primary tumor and 1 patient had a metastatic tumor. Radicular arteries at the tumor level, 1 level above, and 1 level below were permanently occluded when SSEPs and MEPs were preserved during temporary occlusion. No complications were encountered during or after the angiography procedure and embolization.

CONCLUSIONS

Temporary occlusion with electrophysiological monitoring during preoperative angiography may improve the safety of permanent radicular artery occlusion, including the artery of Adamkiewicz in patients undergoing TES for the treatment of spine tumors.

The impact of preoperative identification of the Adamkiewicz artery on descending and thoracoabdominal aortic repair

OBJECTIVE

To investigate the impact of preoperative identification of the Adamkiewicz artery (AKA) on prevention of spinal cord injury (SCI) through the multicenter Japanese Study of Spinal Cord Protection in Descending and Thoracoabdominal Aortic Repair (JASPAR) registry.

METHODS

Between January 2000 and October 2011, 2435 descending/thoracoabdominal aortic repairs were performed, including 1998 elective repairs and 437 urgent repairs, in 14 major centers in Japan. The mean patient age was 67 ± 13 years, and 74.2% were males. There were 1471 open repairs (ORs), including 748 descending and 137 thoracoabdominal extent [Ex] I, 136 Ex II, 194 Ex III, 115 Ex IV, and 138 Ex V, and 964 endovascular repairs (EVRs). Of the 2435 patients, 1252 (51%) underwent preoperative magnetic resonance or computed tomography angiography to identify the AKA.

RESULTS

The AKA was identified in 1096 of the 1252 patients who underwent preoperative imaging (87.6%). Hospital mortality was 9.2% (n = 136) in those who underwent OR and 6.4% (n = 62) in those who underwent EVR. The incidence of SCI was 7.3% in the OR group (descending, 4.2%; Ex I, 9.4%; Ex II, 14.0%; Ex III, 14.4%; Ex IV, 4.2 %; Ex V, 7.2%) and 2.9% in the EVR group. The risk factors for SCI in ORs were advanced age, extended repair, emergency, and occluded bilateral hypogastric arteries. In ORs of the aortic segment involving the AKA, having no AKA reconstruction was a significant risk factor for SCI (odds ratio, 2.79, 95% confidence interval, 1.14-6.79; P = .024).

CONCLUSIONS

In descending/thoracoabdominal aortic repairs, preoperative AKA identification with its adequate reconstruction or preservation, especially, in ORs of aortic pathologies involving the AKA, would be a useful adjunct for more secure spinal cord protection.

Spinal cord injury following thoracic and thoracoabdominal aortic repairs

Objective

To discuss the currently available approaches to prevent spinal cord injury during thoracic and thoracoabdominal aortic repairs.

Methods

We carried out a PubMed search up to 2013 using the Medical Subject Headings: “aortic aneurysm/surgery” and “spinal cord ischemia”; “aortic aneurysm, thoracic/surgery” and “spinal cord ischemia”; “aneurysm/surgery” and “spinal cord ischemia/cerebrospinal fluid”; “aortic aneurysm/surgery” and “paraplegia”. All 190 original articles satisfying our inclusion criteria were analyzed for incidence, predictors, and other pertinent variables related to spinal cord injury, and we compared the results in recent publications with those in earlier reports.

Results

The mean age of the 38,491 patients was 65.3 ± 4.9 years. The overall incidence of paraplegia and/or paraparesis was 7.1% ± 6.1% (range 0%–32%). The incidence of spinal cord injury before 2000, from 2001 to 2007, and 2008–2013 was 9.0% ± 6.7%, 7.0% ± 6.1%, and 5.9% ± 5.2%, respectively ( p = 0.019). Various predictors of spinal cord injury were identified, extent of disease being the most common. Modification of surgical techniques, use of adjuncts, and better understanding of spinal cord perfusion physiology were attributed to the decrease in postoperative spinal cord injury in recent years.

Conclusions

Spinal cord injury after thoracic and thoracoabdominal aortic repair poses a real challenge to cardiovascular surgeons. However, with evolving surgical strategies, identification of predictors, and use of various adjuncts over the years, the incidence of spinal cord injury after thoracic/thoracoabdominal aortic repair has declined. Embracing a multimodality approach offers a good insight into combating this grave complication.

The impact of early pelvic and lower limb reperfusion and attentive peri-operative management on the incidence of spinal cord ischemia during thoracoabdominal aortic aneurysm endovascular repair

OBJECTIVE/BACKGROUND

Spinal cord ischemia (SCI) is a devastating complication following endovascular thoracoabdominal aortic aneurysm (TAAA) repair. In an attempt to reduce its incidence two peri-procedural changes were implemented by the authors in January 2010: (i) all large sheaths are withdrawn from the iliac arteries immediately after deploying the central device and before cannulation and branch extension to the visceral vessels; (ii) the peri-operative protocol has been modified in an attempt to optimize oxygen delivery to the sensitive cells of the cord (aggressive blood and platelet transfusion, median arterial pressure monitoring >85 mmHg, and systematic cerebrospinal fluid drainage).

METHODS

Between October 2004 and December 2013, 204 endovascular TAAA repairs were performed using custom made devices manufactured with branches and fenestrations to maintain visceral vessel perfusion. Data from all of these procedures were prospectively collected in an electronic database. Early post-operative results in patients treated before (group 1, n = 43) and after (group 2, n = 161 patients) implementation of the modified implantation and peri-operative protocols were compared.

RESULTS

Patients in groups 1 and 2 had similar comorbidities (median age at repair 70.9 years [range 65.2-77.0 years]), aneurysm characteristics (median diameter 58.5 mm [range 53-65 mm]), and length of procedure (median 190 minutes [range 150-240 minutes]). The 30 day mortality rate was 11.6% in group 1 versus 5.6% in group 2 (p = .09). The SCI rate was 14.0% versus 1.2% (p < .01). If type IV TAAAs were excluded from this analysis, the SCI rate was 25.0% (6/24 patients) in group 1 versus 2.1% (2/95 patients) in group 2 (p < .01).

CONCLUSION

The early restoration of arterial flow to the pelvis and lower limbs, and aggressive peri-operative management significantly reduces SCI following type I-III TAAA endovascular repair. With the use of these modified protocols, extensive TAAA endovascular repairs are associated with low rates of SCI.

Surgical repair following trauma to vascular graft causing spinal cord infarction

A 55-year-old woman with a background of vascular disease presented with signs of bilateral limb ischaemia. Following elective axillobifemoral bypass and hospital discharge, accidental axillary trauma causing a chest wall haematoma, the patient underwent an emergency graft repair. Postextubation, she reported with absent sensation in her legs. Spinal cord infarction was diagnosed through clinical assessment and exclusion of other causes. The aetiology of compromise to the spinal cord blood supply is unclear. Possibilities include intraoperative hypotension, inadvertent compromise to blood supply of thoracic radicular arteries, dislodged atherosclerotic emboli or a combination of these factors. Spinal cord infarction recognised early can be treated. Sedation to assist ventilation had obscured the problem early enough to consider treatment. Patients with vascular risk factors should be carefully managed intraoperatively to minimise hypotensive episodes and care should also be taken not to compromise blood flow of radicular arteries.

Ischemic preconditioning protects against spinal cord ischemia-reperfusion injury in rabbits by attenuating blood spinal cord barrier disruption

Ischemic preconditioning has been reported to protect against spinal cord ischemia-reperfusion (I-R) injury, but the underlying mechanisms are not fully understood. To investigate this, Japanese white rabbits underwent I-R (30 min aortic occlusion followed by reperfusion), ischemic preconditioning (three cycles of 5 min aortic occlusion plus 5 min reperfusion) followed by I-R, or sham surgery. At 4 and 24 h following reperfusion, neurological function was assessed using Tarlov scores, blood spinal cord barrier permeability was measured by Evan’s Blue extravasation, spinal cord edema was evaluated using the wet-dry method, and spinal cord expression of zonula occluden-1 (ZO-1), matrix metalloproteinase-9 (MMP-9), and tumor necrosis factor-α (TNF-α) were measured by Western blot and a real-time polymerase chain reaction. ZO-1 was also assessed using immunofluorescence. Spinal cord I-R injury reduced neurologic scores, and ischemic preconditioning treatment ameliorated this effect. Ischemic preconditioning inhibited I-R-induced increases in blood spinal cord barrier permeability and water content, increased ZO-1 mRNA and protein expression, and reduced MMP-9 and TNF-α mRNA and protein expression. These findings suggest that ischemic preconditioning attenuates the increase in blood spinal cord barrier permeability due to spinal cord I-R injury by preservation of tight junction protein ZO-1 and reducing MMP-9 and TNF-α expression.

A systematic review of spinal cord injury and cerebrospinal fluid drainage after thoracic aortic endografting

BACKGROUND

The use of thoracic endovascular aneurysm repair (TEVAR) is increasing. Similar to open repair, TEVAR carries a risk of spinal cord ischemia (SCI). We undertook a systematic review to determine whether preoperative cerebrospinal fluid (CSF) drainage reduces SCI.

METHODS

PubMed, the Cochrane Library, and conference abstracts were searched using the keywords thoracic endovascular aortic repair, cerebrospinal fluid, spinal cord ischaemia, TEVAR, and aneurysm. Studies reporting SCI rates and CSF drain rates for TEVAR patients were eligible for inclusion. SCI rates across studies were pooled using random-effects modeling. Study quality was evaluated using the Downs and Black score.

RESULTS

Study quality was generally poor to moderate (median Downs and Black score, 9). The systematic review identified 46 eligible studies comprising 4936 patients; overall, SCI affected 3.89% (95% confidence interval, 2.95.05%-4.95%). Series reporting routine prophylactic drain placement or no prophylactic drain placement reported pooled SCI rates of 3.2% and 3.47%, respectively. The pooled SCI rate from 24 series stating that prophylactic drainage was used selectively was 5.6%.

CONCLUSIONS

Spinal chord injury is uncommon after TEVAR. The role of prophylactic CSF drainage is difficult to establish from the available literature. High-quality studies are required to determine the role of prophylactic CSF drainage in TEVAR.

Descending thoracic aortic surgery: update on mortality, morbidity, risk assessment and management

PURPOSE OF REVIEW

The purpose of this review is to summarize the literature on thoracic aortic surgery, as well as key management guidelines in the perioperative period. This is particularly timely, as endovascular techniques continue to evolve and become more available.

RECENT FINDINGS

Endovascular treatment of thoracic aortic disease is expanding in applications and case complexity.

SUMMARY

With the expanded use of endovascular techniques to treat aortic disease, midterm and long-term outcome studies and comparisons to open surgical approach are now being published with increasing frequency. This review analyzes the available literature on preventing adverse outcomes after descending thoracic aortic surgery, with specific attention to mortality, morbidity, risk assessment and management in the perioperative setting.

Ischemic preconditioning ameliorates spinal cord ischemia-reperfusion injury by triggering autoregulation

OBJECTIVE

The mechanism underlying ischemic preconditioning (IPC) protection against spinal cord ischemia-reperfusion (I/R) injury is unclear. We investigated the role of spinal cord autoregulation in tolerance to spinal cord I/R injury induced by IPC in a rat model.

METHODS

Sprague-Dawley rats were randomly assigned to four groups. IPC (P) group animals received IPC by temporary thoracic aortic occlusion (AO) with a 2F Fogarty arterial embolectomy catheter (Baxter Healthcare, Irvine, Calif) for 3 minutes. The I/R injury (I/R) group animals were treated with blood withdrawal and temporary AO for 12 minutes, and shed blood reinfusion at the end of the procedures. The P+I/R animals received IPC, followed by 5 minutes reperfusion, and then I/R procedures for 12 minutes. Sham (S) group animals received anesthesia and underwent surgical preparation, but without preconditioning or I/R injury. Neurologic function on postprocedure days 1, 3, 5, and 7 was evaluated by Tarlov scoring. Lumbar segments were harvested for histopathologic examination on day 7. To evaluate the role of autoregulation in IPC, spinal cord blood flow and tissue oxygenation were continuously monitored throughout the procedure duration.

RESULTS

The Tarlov scores in the I/R group were significantly lower than those in the S, P, and P+I/R groups on days 1, 3, 5, and 7 (P < .001). No significant differences were noted between the S, P, and P+I/R groups. The numbers of surviving motor neurons in the S, P, and P+I/R groups were significantly higher than those in the I/R group (P < .001); however, the number of surviving motor neurons did not differ between the S, P, and P+I/R groups. The P group exhibited higher spinal cord blood flow (P = .001-.043) and tissue oxygenation (P = .032-.043) within the first 60 minutes after reperfusion than the S group. The P+I/R group exhibited higher spinal cord blood flow (P = .016-.045) and tissue oxygenation (P = .001-.038) within the first 60 minutes after reperfusion than the I/R group.

CONCLUSIONS

IPC ameliorates spinal cord I/R injury in rats, probably mediated by triggering spinal cord autoregulation and improving local spinal cord blood flow and tissue oxygenation. This concept may be the new therapeutic targets in patients requiring aortic surgery.

Docosahexaenoic acid pretreatment confers protection and functional improvements after acute spinal cord injury in adult rats

Currently, few interventions have been shown to successfully limit the progression of secondary damage events associated with the acute phase of spinal cord injury (SCI). Docosahexaenoic acid (DHA, C22:6 n-3) is neuroprotective when administered following SCI, but its potential as a pretreatment modality has not been addressed. This study used a novel DHA pretreatment experimental paradigm that targets acute cellular and molecular events during the first week after SCI in rats. We found that DHA pretreatment reduced functional deficits during the acute phase of injury, as shown by significant improvements in Basso-Beattie-Bresnahan (BBB) locomotor scores, and the detection of transcranial magnetic motor evoked potentials (tcMMEPs) compared to vehicle-pretreated animals. We demonstrated that, at 7 days post-injury, DHA pretreatment significantly increased the percentage of white matter sparing, and resulted in axonal preservation, compared to the vehicle injections. We found a significant increase in the survival of NG2+, APC+, and NeuN+ cells in the ventrolateral funiculus (VLF), dorsal corticospinal tract (dCST), and ventral horns, respectively. Interestingly, these DHA protective effects were observed despite the lack of inhibition of inflammatory markers for monocytes/macrophages and astrocytes, ED1/OX42 and GFAP, respectively. DHA pretreatment induced levels of Akt and cyclic AMP responsive element binding protein (CREB) mRNA and protein. This study shows for the first time that DHA pretreatment ameliorates functional deficits, and increases tissue sparing and precursor cell survival. Further, our data suggest that DHA-mediated activation of pro-survival/anti-apoptotic pathways may be independent of its anti-inflammatory effects.

Endovascular management of thoracic aortic aneurysms

The overall survival of patients with thoracic aortic aneurysm (TAA) has improved significantly in the past few years. Endovascular treatment, proposed as an alternative to surgery, has been considered a therapeutic innovation because of its low degree of invasiveness, which allows the treatment of even high-surgical risk patients with limited complications and mortality. A major limitation is the lack of adequate evidence regarding long-term benefit and durability because follow-up has been limited to just a few years even in the largest series. The combination of endovascular exclusion with visceral branch revascularization for the treatment of thoraco-abdominal aortic aneurysms involving the visceral aorta has also been attempted. As an alternative, endografts with branches represent a technological evolution that allows treatment of complex anatomy. Even if only small numbers of patients and short follow-up are available, this technical approach, which has with limited mortality (<10%) and paraplegia rates, to expand endovascular treatment to TAA seems feasible. With improved capability to recognize proper anatomy and select clinical candidates, the choice of endovascular stent-graft placement may offer a strategy to optimize management and improve prognosis.