Computed tomography angiography assessment of Adamkiewicz artery with sublingual nitroglycerin administration

PURPOSE

Identification of the Adamkiewicz artery before aortic surgery is important for preventing postoperative complications due to spinal cord ischemia. The Adamkiewicz artery is difficult to identify due to its small diameter. Nitroglycerin has a vasodilatory effect and is used clinically to improve visualization of blood vessels on coronary computed tomography (CT) angiography. We investigated whether the vasodilatory effect of nitroglycerin could improve the ability to visualize the Adamkiewicz artery.

METHODS

We extracted 33 cases wherein contrast-enhanced CT images were taken before and after aortic aneurysm surgery. Nitroglycerin was administered for coronary artery evaluation on the preoperative CT. However, no nitroglycerin was administered before the postoperative CT. Aortic contrast-to-noise ratio, CT value, image noise, and diameter of the Adamkiewicz artery and anterior spinal artery were measured. The depiction of the Adamkiewicz artery was graded into four grades and evaluated. These measurements were performed by two independent reviewers.

RESULTS

In nitroglycerin-administered cases, the contrast-to-noise ratio and CT values were significantly higher (P < 0.001, P < 0.001, respectively); the Adamkiewicz artery and anterior spinal artery diameters were dilated (P = 0.005, P = 0.001, respectively). The Adamkiewicz artery score also improved significantly (P < 0.001). No significant difference was found in image noise.

CONCLUSION

Nitroglycerin contributed to improving the Adamkiewicz artery's visualization.

Near-Infrared Spectroscopy for Spinal Cord Monitoring-A Roadmap to Translational Research in Aortic Medicine

Extensive aortic aneurysms represent a unique challenge necessitating interdisciplinary efforts for safe and effective treatment. Despite various adjunctive neuroprotective strategies, ischemic spinal cord injury remains a devastating complication. This article describes the implementation of collateral network near-infrared spectroscopy as the first noninvasive spinal cord monitoring modality in the setting of extensive open and endovascular aortic repair, from early conceptualization to clinical utilization. Potential capabilities and remaining uncertainties based on current evidence are outlined and discussed.

Diagnosis and treatment of neurogenic bladder secondary to aortic dissection: A 8-year retrospective study at a single center

PURPOSE

To review the characteristics of the neurogenic lower urinary tract dysfunction (NLUTD) secondary to aortic dissection (AD), analyze the clinical features, and discuss the treatment options.

METHODS

Ten individuals complaining of lower urinary tract syndrome following AD were enrolled in this study. Clinical characteristics, urological and neurological symptoms/signs, imaging examination, and intervention were reviewed. Liao's comprehensive classification system was used to precisely assess the lower and upper urinary dysfunction.

RESULTS

The urinary symptoms can be varied, including dysuria, incontinence, and frequency. Individuals were divided into the detrusor overactivity (DO) and detrusor underactivity (DU) subgroups. Continence, impaired upper urinary tract functions (renal insufficiency, vesicoureteral reflux, upper urinary tract dilatation, and lower urinary tract functions (DO and/or detrusor external sphincter dyssynergia/detrusor bladder neck dyssynergia, DU, low bladder capacity, and compliance) were examined using video-urodynamics. The principle of treatment is "low-pressure bladder storage with complete bladder emptying," and close follow-up was recommended due to the volatile course of NLUTD.

CONCLUSIONS

Both cardiovascular surgeons and urologists should pay attention to the occurrence of NLUTD following AD, and determine the most appropriate therapeutic option.

Lumbar Paraspinal Compartment Syndrome: Case Report and Critical Evaluation of the Literature

BACKGROUND

Lumbar compartment syndrome is a recognized clinical phenomenon, despite receiving less attention as a clinical entity. Given its rarity, the definitive presentation, diagnosis, and management strategies are not completely agreed upon.

MATERIALS AND METHODS

A literature search on PubMed of all case reports of lumbar paraspinal compartment syndromes was conducted. All case reports and reviews were analyzed for patient demographic data, presentation, diagnostic evaluation, treatment, and clinical follow-up.

RESULTS

A total of 37 cases of lumbar compartment syndrome were identified. Overall, 91.9% occurred in men with an average age of 30.9 years. Weightlifting (n=18, 48.6%) and physical exertion (n=7, 18.9%) accounted for the majority of presentations. In all, 37.8% of cases occurred unilaterally. Creatinine kinase, aspartate aminotransferase, and alanine aminotransferase were notably elevated. Compartment pressure was elevated with an average of 91.8 mm Hg (SD: 44.8 mm Hg). Twenty-two cases were treated operatively (59.5%) and 15 (40.5%) were treated nonoperatively. In total, 19/20 (95.0%) of cases treated operatively reported either resolution of pain or return to baseline activities without limitation, compared with 1/11 (9.1%) treated nonoperatively. This difference between the operative and nonoperative cohort was statistically significant ( P <0.0001).

CONCLUSIONS

Lumbar paraspinal compartment syndrome is a rare, but well-documented clinical entity. In all, 67.5% of cases occurred after weightlifting or physical exertion. Overall, 40.5% of cases in the literature were treated nonoperatively. Per our analysis, there is a clinically and statistically significant difference in cases treated operatively versus nonoperatively (95.0% vs. 9.1%, P <0.0001).

Cerebrospinal Fluid Drainage in Thoracic and Thoracoabdominal Endovascular Aortic Repair: A Survey of Current Clinical Practice in European Medical Centers

OBJECTIVES

The aim of this survey was to evaluate the daily clinical practice in European hospitals regarding the modalities to prevent spinal cord ischemia, with an emphasis on cerebrospinal fluid drainage (CSFD), in patients undergoing thoracic and thoracoabdominal endovascular repair.

DESIGN

A 21-item online survey on current practice of spinal cord protection with an emphasis on CSFD.

SETTING

Online service using Castor EDC software.

PARTICIPANTS

Members of the European Association of Cardiothoracic Anaesthesiology and Intensive Care and European Society of Vascular Surgeons.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

One hundred eighty invitations were sent and 104 were used for analysis. A majority of respondents used a written protocol for spinal cord protection during endovascular thoracic and thoracoabdominal repair (81/104 = 78%). The most common protective measures used were CSFD (79/81 = 98%), controlled hypertension (59/81 = 73%), drugs (11/81 = 14%), and hypothermia (6/81 = 7%). The two most common indications for placement of a spinal catheter were the length of the stent (83/104 = 80%) and location of aneurysm (71/104 = 68%). Preventive placement of the spinal drain (96/104) is the most common approach. In the subgroup of high-volume centers, 86% (12/14) of the respondents used a written protocol and all protocols include CSFD. Ninety-two percent (11/12) had included controlled arterial hypertension in the protocol compared with 70% (48/69) of the non-high-volume centers respondents.

CONCLUSIONS

The majority of European centers use a written protocol that includes CSFD. This survey showed the similarities and differences in the management of CSFD in patients undergoing endovascular thoracic and thoracoabdominal repair.

Experimental near-infrared spectroscopy-guided minimally invasive segmental artery occlusion

OBJECTIVES

Minimally invasive staged segmental artery (SA) coil- and plug embolization is a new method for paraplegia prevention associated with extensive aortic procedures. Near-infrared spectroscopy of the paraspinal collateral network (cnNIRS) has emerged as a non-invasive method for spinal cord monitoring. The aim of this study was to evaluate cnNIRS to guide minimally invasive SA occlusion.

METHODS

In a chronic large animal experiment, 18 juvenile pigs underwent two-stage minimally invasive staged SA coil- and plug embolization for complete SA occlusion. Coil-embolization was performed either by SA main stem occlusion (characteristic of pig anatomy) or separately for the left- and right SA. Lumbar cnNIRS was recorded during and after the procedure. Neurological status was assessed up to 3 days after complete SA occlusion.

RESULTS

Mean time from SA coil embolization to minimum cnNIRS values was 11 ± 5 min with an average decrease from 101 ± 2% to 78 ± 8% of baseline (difference: -23 ± 9, P < 0.001). Lumbar cnNIRS demonstrated significant differences between left and right when SAs were occluded separately in all cases (-7 ± 4%, 1 min after first SA occlusion; P = 0.001). Permanent paraplegia occurred in 2 (11%) and any kind of neurological deficit-temporary or permanent-in 7 animals (39%). Association between lumbar cnNIRS and neurological outcome after minimally invasive staged SA coil- and plug embolization suggests positive correlation (R = 0.5, P = 0.052).

CONCLUSIONS

Lumbar cnNIRS independently reacts to unilateral SA occlusion. cnNIRS-guided SA occlusion is feasible and may become a useful adjunct facilitating adequate and complete vessel occlusion.

Collateral Circulation in Spinal Cord Injury: A Comprehensive Review

Surgery is the most common cause of spinal cord ischemia; it is also caused by hemodynamic changes, which disrupt the blood flow. Direct ligation of the spinal arteries, especially the Adamkiewicz artery is involved as well. Other causes of spinal cord ischemia include arteriography procedures, thoracic surgery, epidural and rachianesthesia, foraminal infiltration, arterial dissection, systemic hypotension, emboligenic heart disease, thoracic disc herniation, and compression. Understanding the vascular anatomy of the spinal cord is essential to develop optimal strategies for preventing ischemic injuries to the spinal cord. During ischemia, a rich network of intra and paraspinal collaterals allow enough blood flow to compensate the intensity of spinal cord ischemia. In case of interruption of flow of a main artery, the collateral artery increases its flow to maintain perfusion to the tissues. Avoiding spinal cord ischemia by using collateral circulation is necessary to prevent the establishment of hypovolemia, hyperthermia and elevations in venous pressures. The objective of this narrative review is to present the current concepts of spinal collateral circulation and its role in the setting of ischemic events, affecting the vascular supply of the spinal cord.

Epidural Corticosteroids, Lumbar Spinal Drainage, and Selective Hemodynamic Control for the Prevention of Spinal Cord Ischemia in Thoracoabdominal Endovascular Aortic Repair: A New Clinical Protocol

INTRODUCTION

In patients undergoing thoracoabdominal aorta repair, spinal cord ischemia (SCI) remains one of the most common and important complications resulting in transient paraparesis through to permanent flaccid paraplegia. In this manuscript, after a brief introduction to spinal cord ischemia complication and its prevention in thoracoabdominal endovascular aortic repair (TEVAR), we propose a new clinical protocol potentially able to prevent such complication.

METHODS

The proposed protocol suggests the use of high dosages of corticosteroids by epidural route, along with drainage of cerebrospinal fluid and controlled vascular hypertension, to reduce the incidence of SCI in TEVAR. Moreover, we paid particular attention to the control of the hemodynamic parameters to obtain adequate peripheral tissue perfusion (oxygen delivery), including in the spinal cord.

RESULTS

We applied this new protocol in 50 consecutive patients treated with TEVAR for thoracoabdominal aortic aneurysms (TAAs); 47 patients completed the procedure: 27 patients Crawford type I and 20 Crawford type II. Three patients died during surgery because of untreatable aneurysm rupture. The results show that in all patients there were no cases of SCI, after 5 days from TEVAR.

DISCUSSION

To the best of our knowledge, there are no clinical studies on the use of epidural corticosteroids in patients undergoing treatment of aortic syndrome (both in "open surgery" and endovascular aortic repair). This initial study on 50 consecutive patients has shown that the clinical protocol used could be of great interest to prevent one of the worse complications of TEVAR. Its limitations are the low number of patients studied till now, and the non-randomized protocol adopted. Further studies would be necessary.

CONCLUSION

Our experience and the results obtained with this new perioperative protocol with epidural corticosteroid and accurate hemodynamic control have been encouraging and it seems a valid proposal to be explored in future by well-structured prospective, randomized protocols.

Outcomes of a Spinal Drain and Intraoperative Neurophysiologic Monitoring Protocol in Thoracic Endovascular Aortic Repair

BACKGROUND

Adjuncts for early detection and treatment of spinal cord ischemia (SCI) in thoracic aortic surgery are supported by robust clinical experience in open repair. The utility of cerebrospinal fluid (CSF) drainage and neurophysiologic monitoring (NPM) in thoracic endovascular aortic repair (TEVAR) is less clear. The purpose of this investigation is to determine the influence of a selective institutional spinal cord protection protocol using prophylactic NPM and CSF on outcomes for standard TEVAR.

METHODS

Patients undergoing standard TEVAR entered into a prospectively maintained database from a single institution from 2007 to 2016 were retrospectively reviewed. Preoperative characteristics, aneurysm extent, and etiology were reviewed. Utilization of CSF drains including volume of fluid removed, duration of drainage, and catheter-related complications were collected. NPM data were reviewed to determine the influence on intraoperative management. Exact logistic regression was used to identify independent predictors of SCI.

RESULTS

Of 223 patients undergoing TEVAR, 130 met inclusion criteria for the study. CSF drains were used in 71 patients (54.6%), and 56 of 130 (43%) had NPM. SCI occurred in 7 patients (5.4%), of whom 5 had partial or complete recovery. Median time to symptoms of SCI was delayed in all cases (median 52 hr, range 8-312), and none of the 4 of 7 patients with adjunct NPM demonstrated intraoperative changes. Intraoperative changes in NPM occurred in 26 (46%), and represented unilateral leg ischemia in all but 2 cases. In both patients, changes consistent with SCI were associated with intraoperative hypotension and resolved with blood pressure augmentation. Neither patient developed postoperative SCI. Median length of stay (22 vs. 9 days, P = 0.012), operative room time (262 vs. 209, P = 0.040), and perioperative mortality (28.6% vs. 4.1%, P = 0.046) were significantly higher for patients with SCI versus those without. Length of aortic coverage was found to be the sole independent predictor of SCI (odds ratio 8.2, P = 0.026). Complications related to CSF drainage occurred in 4 patients (5.6%) with major complications occurring in 2 patients (2.8%), including 1 with an intrathecal hematoma and permanent bilateral paraparesis.

CONCLUSIONS

Selective use of prophylactic CSF drainage in TEVAR was associated with moderate risk and questionable benefit. The use of neurophysiological monitoring allowed for early detection and treatment of spinal ischemia, but its utility is limited by logistical factors and to the minority of patients with intraoperative spinal ischemic events.

The strategies and outcomes of left subclavian artery revascularization during thoracic endovascular repair for type B aortic dissection

This study was to analyze the outcomes of left subclavian artery (LSA) revascularization during thoracic endovascular repair (TEVAR) for type B aortic dissections (TBAD). From 2011 to 2017, TBAD patients who underwent LSA revascularization during TEVAR were enrolled. Technical success, endoleaks, mortality, complication, reintervention, and patency of target vessels were analyzed. 38 patients were included, 14 underwent carotid-subclavian bypass (CSB), and 24 underwent chimney graft (CG) implantation. Technical success rates were 92.9% and 100% in CSB and CG group. Eleven immediate type I endoleak (EL-I) was detected, including one from CSB group and ten from CG group. Three immediate type II endoleak (EL-II) was detected in CSB group. Perioperative complications showed no difference, but CSB group had longer intensive care unit (ICU) stay time. Median follow-up time was 26.2 months, and overall mortality was 14.3% and 0% in each group. Three EL-I and one EL-II underwent reintervention. All the LSA showed good patency, except one suffered from CG collapse. Both CSB and CG were feasible strategies to preserve the antegrade blood flow of LSA, and each strategy had its advantages and disadvantages. Based on our current experience, we preferred CG for high-risk patients. However, the evidence was still not strong enough, further well-designed studies are necessary to identify the criteria for LSA revascularization strategy during TEVAR.

Branched Thoraco-Abdominal Aortic Aneurysm Repair with Branch Access Through a Transapical Left Ventricular Approach

Branched thoracic aortic aneurysm repair requires arterial access from above the diaphragm in order to insert the visceral branches. This is routinely performed from the subclavian, axillary or carotid arteries and less commonly direct thoracic aorta puncture. The left ventricular apex is an alternative access route which is commonly used for percutaneous aortic valve replacement and rarely used for EVAR, FEVAR and TEVAR access. Here we describe two patients for which the left ventricular apex was the most suitable available access to the visceral branches during a branched thoracic aortic aneurysm repair. This access should be considered as an alternative approach if conventional arterial access is not available.

The attenuation of neurological injury from the use of simvastatin after spinal cord ischemia-reperfusion injury in rats

Background

Spinal cord ischemic injury remains a serious complication of open surgical and endovascular aortic procedures. Simvastatin has been reported to be associated with neuroprotective effect after spinal cord ischemia-reperfusion (IR) injury. The aim of this study was to determine the therapeutic efficacy of starting simvastatin after spinal cord IR injury in a rat model.

Methods

In adult Sprague-Dawley rats, spinal cord ischemia was induced using a balloon-tipped catheter placed in the descending thoracic aorta. The animals were then randomly divided into 4 groups: group A (control); group B (0.5 mg/kg simvastatin); group C (1 mg/kg simvastatin); and group D (10 mg/kg simvastatin). Simvastatin was administered orally upon reperfusion for 5 days. Neurological function of the hind limbs was evaluated for 7 days after reperfusion and recorded using a motor deficit score (MDS) (0: normal, 5: complete paraplegia). The number of normal motor neurons within the anterior horns of the spinal cord was counted after final MDS evaluation. Then, the spinal cord was harvested for histopathological examination.

Results

Group D showed a significantly lower MDS than the other groups at post-reperfusion day 1 and this trend was sustained throughout the study period. Additionally, a greater number of normal motor neurons was observed in group D than in other groups (group D 21.2 [3.2] vs. group A: 15.8 [4.2]; group B 15.4 [3.4]; and group C 15.5 [3.7]; P = 0.002).

Conclusions

The results of the current study suggest that 10 mg/kg can significantly improve neurologic outcome by attenuating neurologic injury and restoring normal motor neurons after spinal cord IR injury.

Blunt Injury of the Innominate Artery: What Surprises to Expect? A Case Report

Injuries of the supra-aortic trunk after blunt chest trauma are rare. This is a case report of a blunt traumatic lesion of the innominate artery (IA) origin that exhibited aortic arch involvement with a focus on imaging and treatment. A 41-year-old fisherman presented an IA injury secondary to a high-impact blunt chest trauma. Upon physical examination, vital signs were stable and upper extremity pulses were present. In addition to several bone fractures (costal ribs, clavicle, scapula, temporal, maxillary, and sphenoid), computed tomography angiography revealed dissection/pseudoaneurysm of the IA sparing the bifurcation. The patient underwent emergent angiography, which confirmed that the IA dissection was not ruptured, but it was unclear whether there was a pseudoaneurysm at the origin of the IA or aortic arch involvement. The patient was considered for open surgery. An ascending aorta-to-IA bypass was achieved by the off-pump beating heart approach. The IA stump was carefully observed, but oversewing was not possible due to the extension of the intimal-medial lesions into the artic arch. An on-pump intervention was then required for aortic angioplasty with a pericardial patch that was reinforced by Gel Seal. The postoperative course was uneventful. The patient was discharged without any complications. Conventional surgery provides good results and should remain in the armamentarium for the treatment of traumatic lesions at the IA origin, particularly if aortic arch involvement cannot be ruled out, to ensure a truly patient-tailored approach.