Cost-benefit analysis of intraoperative neuromonitoring for cardiac surgery.

BACKGROUND: Intraoperative neuromonitoring (IONM) can detect large vessel occlusion (LVO) in real-time during surgery. The aim of this study was to conduct a cost-benefit analysis of utilizing IONM among patients undergoing cardiac surgery. METHODS: A decision-analysis tree with terminal Markov nodes was constructed to model functional outcome, as measured via the modified Rankin Scale (mRS), among 65-year-old patients undergoing cardiac surgery. Our cost-benefit analysis compares the use of IONM (electroencephalography and somatosensory evoked potential) against no IONM in preventing neurological complications from perioperative LVO during cardiac surgery. The study was performed over a lifetime horizon from a societal perspective in the United States. Base case and one-way probabilistic sensitivity analyses were performed. RESULTS: At a baseline LVO rate of 0.31%, the mean attributable lifetime expenditure for IONM-monitored cardiac surgeries relative to unmonitored cardiac surgeries was $1047.41 (95% CI, $742.12 - $1445.10). At a critical LVO rate of approximately 3.67%, the costs of both monitored and unmonitored cardiac surgeries were the same. Above this critical rate, implementing IONM became cost-saving. On one-way sensitivity analysis, variation in LVO rate from 0% - 10% caused lifetime costs attributable to receiving IONM to range from $1150.47 - $29404.61; variations in IONM cost, percentage of intervenable LVOs, IONM sensitivity, and mechanical thrombectomy cost exerted comparably minimal influence over lifetime costs. DISCUSSION: We find considerable cost savings favoring the use of IONM under certain parameters corresponding to high-risk patients. This study will provide financial perspective to policymakers, clinicians, and patients alike on the appropriate use of IONM during cardiac surgery.

Treatable childhood neuronopathy caused by mutations in riboflavin transporter RFVT2.

Childhood onset motor neuron diseases or neuronopathies are a clinically heterogeneous group of disorders. A particularly severe subgroup first described in 1894, and subsequently called Brown-Vialetto-Van Laere syndrome, is characterized by progressive pontobulbar palsy, sensorineural hearing loss and respiratory insufficiency. There has been no treatment for this progressive neurodegenerative disorder, which leads to respiratory failure and usually death during childhood. We recently reported the identification of SLC52A2, encoding riboflavin transporter RFVT2, as a new causative gene for Brown-Vialetto-Van Laere syndrome. We used both exome and Sanger sequencing to identify SLC52A2 mutations in patients presenting with cranial neuropathies and sensorimotor neuropathy with or without respiratory insufficiency. We undertook clinical, neurophysiological and biochemical characterization of patients with mutations in SLC52A2, functionally analysed the most prevalent mutations and initiated a regimen of high-dose oral riboflavin. We identified 18 patients from 13 families with compound heterozygous or homozygous mutations in SLC52A2. Affected individuals share a core phenotype of rapidly progressive axonal sensorimotor neuropathy (manifesting with sensory ataxia, severe weakness of the upper limbs and axial muscles with distinctly preserved strength of the lower limbs), hearing loss, optic atrophy and respiratory insufficiency. We demonstrate that SLC52A2 mutations cause reduced riboflavin uptake and reduced riboflavin transporter protein expression, and we report the response to high-dose oral riboflavin therapy in patients with SLC52A2 mutations, including significant and sustained clinical and biochemical improvements in two patients and preliminary clinical response data in 13 patients with associated biochemical improvements in 10 patients. The clinical and biochemical responses of this SLC52A2-specific cohort suggest that riboflavin supplementation can ameliorate the progression of this neurodegenerative condition, particularly when initiated soon after the onset of symptoms.

The influence of primary language on postoperative stroke outcomes.

BACKGROUND: Language barriers have the potential to influence acute stroke outcomes. Thus, we examined postoperative stroke outcomes among non-English primary language speakers. METHODS: Utilizing the Healthcare Cost and Utilization Project State Inpatient Database (2016-2019), we conducted a retrospective cohort study of adults diagnosed with a postoperative stroke in Michigan, Maryland, and New Jersey. Patients were classified by primary language spoken: English (EPL) or non-English (n-EPL). The primary outcome was hospital length-of-stay. Secondary outcomes included stroke intervention, feeding tube, tracheostomy, mortality, cost, disposition, and readmission. Propensity-score matching and post-match regression were used to quantify outcomes. RESULTS: Among 3078 postoperative stroke patients, 6.2 â€‹% were n-EPL. There were no differences in length-of-stay or secondary outcomes, except for higher odds of feeding tube placement (OR 1.95, 95 â€‹% CI 1.10-3.47, p â€‹= â€‹0.0227) in n-EPL. CONCLUSIONS: Postoperative stroke outcomes were comparable by primary language spoken. However, higher odds of feeding tube placement in n-EPL may suggest differences in patient-provider communication.

Predictors of outcome in patients with spinal cord ischemia after open aortic repair.

INTRODUCTION: Spinal cord ischemia is a potentially devastating complication of thoracic aortic surgery. However, predictors of outcome have not been well characterized. The study objective was to generate a prognostic score that accurately stratifies patient outcomes, aiding in future management and planning. METHODS: A retrospective review of 224 consecutive open thoracic aortic surgeries identified patients with spinal cord ischemia, defined as changes on intraoperative somatosensory evoked potentials (SSEP) and/or paraparesis/paraplegia postoperatively. The outcome of interest was poor outcome, defined as death or discharge with a lower extremity motor score ≤40, indicating impaired ambulation. Demographic and clinical characteristics were tested in univariate analyses and significant factors were incorporated in multivariate modeling to determine independent predictors of poor outcome. RESULTS: Seventy-five patients were identified with spinal cord ischemia, of which 43(57 %) had poor outcomes including 28(37 %) that died prior to discharge. Factors associated with poor outcome in univariate analysis included absent lumbar CSF drain (p = 0.03), surgical repair that crossed the diaphragm (p = 0.002), permanent intraoperative SSEP change (p = 0.02), postoperative renal failure (p = 0.004), paraplegia (p = 0.001), and concomitant stroke (p = 0.04). In multivariable analysis, surgical repair crossing the diaphragm (OR 4.8, CI 1.4-16.7, p = 0.02), paraplegia (OR 4.5, CI 1.4-14.0, p = 0.01), and renal failure (OR 6.1, CI 1.7-21.2, p = 0.005) were independently associated with poor outcome. Patients with transient intraoperative neurophysiologic changes were least likely to have poor outcome when compared to patients with no or permanent SSEP changes, and those not monitored (p = 0.03). CONCLUSION: Development of spinal cord ischemia with thoracic aortic repair often leads to death or disability. Characteristics known at the time of event can accurately predict the likelihood of poor outcome.

A pilot study of darbepoetin alfa for prophylactic neuroprotection in aortic surgery.

BACKGROUND: Descending aortic (DA) surgery poses a high risk for spinal and cerebral infarction and routine use of lumbar drains allows for measurement of CSF markers of neurologic injury. Erythropoiesis medications have extensive preclinical data demonstrating neuroprotection. We hypothesized that prophylactic darbepoetin alfa (DARB) given before surgery reduces neurologic injury in patients undergoing DA repair. METHODS AND RESULTS: We performed a prospective adaptive dose-finding trial of prophylactic DARB ( www.clinicaltrials.gov NCT00647998) that terminated prematurely following publication of an erythropoietin stroke study showing possible harm. Enrollment halted before dose adjustments; nine patients each received 1 mg/kg IV DARB immediately before surgery. A prospective cohort of nine untreated patients was subsequently obtained for comparison. The primary outcome of death or neurologic impairment at discharge occurred in 1/9 (11 %) DARB patients and 3/9 (33 %) controls (p = 0.58). There were no statistical differences in changes of CSF biomarkers from baseline to 48 h comparing DARB patients to controls: S100ß, median 214 versus 260 ng/ml (p = 0.69); glial fibrillary acidic protein (GFAP), median 0.022 versus 0.58 ng/ml (p = 0.45). In patients with early perioperative neurologic ischemia, there were greater changes in CSF biomarkers, compared to those without ischemia: S100ß, median 2301 versus 124 ng/ml (p = 0.04); GFAP, median 31.78 versus 0.31 ng/ml (p = 0.34). CONCLUSIONS: There were no significant effects of prophylactic DARB on clinical outcome or CSF markers of neurologic injury in this pilot study, although all point estimates favored treatment. DA repair is a promising model of prophylactic neuroprotection.

Derivation and Validation of an Algorithm to Detect Stroke Using Arm Accelerometry Data.

Background Early diagnosis is essential for effective stroke therapy. Strokes in hospitalized patients are associated with worse outcomes compared with strokes in the community. We derived and validated an algorithm to identify strokes by monitoring upper limb movements in hospitalized patients. Methods and Results A prospective case-control study in hospitalized patients evaluated bilateral arm accelerometry from patients with acute stroke with lateralized weakness and controls without stroke. We derived a stroke classifier algorithm from 123 controls and 77 acute stroke cases and then validated the performance in a separate cohort of 167 controls and 33 acute strokes, measuring false alarm rates in nonstroke controls and time to detection in stroke cases. Faster detection time was associated with more false alarms. With a median false alarm rate among nonstroke controls of 3.6 (interquartile range [IQR], 2.1-5.0) alarms per patient per day, the median time to detection was 15.0 (IQR, 8.0-73.5) minutes. A median false alarm rate of 1.1 (IQR. 0-2.2) per patient per day was associated with a median time to stroke detection of 29.0 (IQR, 11.0-58.0) minutes. There were no differences in algorithm performance for subgroups dichotomized by age, sex, race, handedness, nondominant hemisphere involvement, intensive care unit versus ward, or daytime versus nighttime. Conclusions Arm movement data can be used to detect asymmetry indicative of stroke in hospitalized patients with a low false alarm rate. Additional studies are needed to demonstrate clinical usefulness.

Reversal of delayed-onset paraparesis after revision thoracic endovascular aortic repair for ruptured thoracic aortic aneurysm.

Thoracic endovascular aortic repair (TEVAR) is an important surgical option for the emergency treatment of ruptured thoracic aortic aneurysms, but is associated with a risk of spinal cord ischemia (SCI). Although risk factors for the development of SCI have been well described, the effectiveness of treatment to increase spinal cord perfusion pressure remains incompletely understood. We report the successful treatment of delayed-onset paraparesis after revision TEVAR for acute descending thoracic aortic rupture with the combined use of blood pressure augmentation and cerebrospinal fluid drainage. The clinical manifestations, pathophysiology, and management of SCI after TEVAR are reviewed.

Cerebral embolic exposure during transfemoral and transapical transcatheter aortic valve replacement.

AIM OF STUDY: To characterize the cerebral embolic exposure during transfemoral (TF) and transapical (TA) TAVR. METHODS: To detect cerebral embolic events during TAVR, intraoperative neuromonitoring using transcranial Doppler (TCD) was utilized in 28 patients (Edwards SAPIEN valve TF n = 18, TA n = 10). High intensity transient signals (HITS) reflective of embolic events were recorded. RESULTS: The mean age was 83.4 ± 7.4 years. The Society of Thoracic Surgeons predicted risk of mortality score was 11.7 ± 2.9. The total number of HITS during TAVR was not significantly different between the TF and the TA groups, respectively (375 ± 301, 440 ± 283, p = 0.58). The highest number of HITS occurred during wire manipulation in the arch and valve insertion (TF, 80 ± 110, 107 ± 81; TA, 120 ± 80, 92 ± 80). In the TF group only, severe arch calcification was associated with significantly higher number of HITS both in total number of HITS (Grade I/II, 278 ± 71; Grade III/IV, 568 ± 479, p = 0.05) and during wire manipulation in the arch and valve insertion (Grade I/II, 140 ± 46, Grade III/IV 294 ± 239, p = 0.04). CONCLUSIONS: Highest cerebral embolic exposure occurred during wire manipulation in the arch and valve insertion in both the TF and TA groups. Arch calcification appears to be associated with increased embolic risk, specifically in the TF approach. Understanding of the mechanism of cerebral embolism is needed for future strategies of cerebral protection during TAVR.

Enhanced Fiber Tractography Using Edema Correction: Application and Evaluation in High-Grade Gliomas.

BACKGROUND: A limitation of diffusion tensor imaging (DTI)-based tractography is peritumoral edema that confounds traditional diffusion-based magnetic resonance metrics. OBJECTIVE: To augment fiber-tracking through peritumoral regions by performing novel edema correction on clinically feasible DTI acquisitions and assess the accuracy of the fiber-tracks using intraoperative stimulation mapping (ISM), task-based functional magnetic resonance imaging (fMRI) activation maps, and postoperative follow-up as reference standards. METHODS: Edema correction, using our bi-compartment free water modeling algorithm (FERNET), was performed on clinically acquired DTI data from a cohort of 10 patients presenting with suspected high-grade glioma and peritumoral edema in proximity to and/or infiltrating language or motor pathways. Deterministic fiber-tracking was then performed on the corrected and uncorrected DTI to identify tracts pertaining to the eloquent region involved (language or motor). Tracking results were compared visually and quantitatively using mean fiber count, voxel count, and mean fiber length. The tracts through the edematous region were verified based on overlay with the corresponding motor or language task-based fMRI activation maps and intraoperative ISM points, as well as at time points after surgery when peritumoral edema had subsided. RESULTS: Volume and number of fibers increased with application of edema correction; concordantly, mean fractional anisotropy decreased. Overlay with functional activation maps and ISM-verified eloquence of the increased fibers. Comparison with postsurgical follow-up scans with lower edema further confirmed the accuracy of the tracts. CONCLUSION: This method of edema correction can be applied to standard clinical DTI to improve visualization of motor and language tracts in patients with glioma-associated peritumoral edema.

Management of neurologic complications of thoracic aortic surgery.

Neurologic complications of thoracic aortic surgery are strongly associated with increased morbidity and mortality. Identifying preoperative risk factors for neurologic injury may enable us to refine our perioperative approach, and to lessen or avoid these complications. Methods to identify stroke and spinal ischemia intraoperatively such as neurophysiologic monitoring may enable us to improve outcomes in these patients by immediately instituting measures to improve brain and spine perfusion. The development of both protocols and therapies to treat these complications has allowed us to mitigate and, at times, reverse neurologic injury both intraoperatively and postoperatively.

Significance of malperfusion syndromes prior to contemporary surgical repair for acute type A dissection: outcomes and need for additional revascularizations.

OBJECTIVE: The aim of this study was to assess the significance of malperfusion syndromes in patients with acute type A aortic dissection following a contemporary surgical management algorithm and the effects on morbidity, hospital mortality, and long-term survival. We believe that obliteration of the primary tear site with restoration of flow in the true aortic lumen results in decreased need for revascularization of malperfused organ systems. METHODS: Our operative approach aims at replacing the entire ascending aorta, resuspension of the aortic valve with repair or replacement of the sinus segment, and routine open replacement of the arch under hypothermic circulatory arrest with retrograde cerebral perfusion with obliteration of false lumen at the distal arch/proximal descending thoracic aorta, thus reestablishing normal flow in the descending thoracic true lumen. From January 1993 to December 2004, 221 consecutive patients underwent repair of acute type A aortic dissection at our institution. Data were collected retrospectively and prospectively. Various types of malperfusion syndromes were present in 26.7% of patients. The organ systems with malperfusion were as follows: cardiac, 7.2%; cerebral, 7.2%; ileofemoral, 12.7%; renal, 4.1%; mesenteric, 1.4%; innominate, 5.4%; and spine, 2.2%. RESULTS: Coronary malperfusion required coronary revascularization in 62.5% of cases. Distal revascularization was needed in 42.9% of patients with ileofemoral malperfusion. Patients with malperfusion were more likely to suffer perioperative myocardial infarction (p<0.001), postoperative coma (p=0.012), delirium (p=0.011), sepsis (p=0.006), acute renal failure (p=0.017), dialysis (p=0.018), and acute limb ischemia (p<0.001). The in-hospital mortality was 30.5% in patients presenting with any malperfusion syndrome while only 6.2% in patients without malperfusion syndrome (p<0.001). Both cardiac (p=0.020) and cerebral malperfusions (p<0.001) were risk factors for in-hospital mortality. The actuarial long-term survival in patients with malperfusion syndrome was estimated by Kaplan-Meier methods to be 67.8%+/-6.1% at 1 year, 54.0%+/-7.0% at 5 years, and 43.1%+/-8.0% at 10 years and for patient without malperfusion 82.7%+/-3.0% at 1 year, 66.3%+/-3.9% at 5 years, and 46.1%+/-6.7% at 10 years (log rank 2.55, p=0.110). Cerebral malperfusion was a significant risk factor for decreased long-term survival (p=0.0002). CONCLUSIONS: The occurrence of malperfusion in patients with acute type A dissection is associated with significant increased risk of in-hospital mortality and complications. Additional revascularization is generally needed in patients with coronary malperfusion and ileofemoral malperfusion. Patients presenting with cardiac and cerebral malperfusions have a high hospital mortality and preoperative cerebral malperfusion is associated with dismal long-term survival.

Safety and efficacy of thrombolytic therapy in postoperative cerebral infarctions.

Acute ischemic stroke is a common and devastating complication of many surgical procedures. If diagnosed early, however, there are reasonably safe and effective treatment options. Although IV rtPA is the most well studied means of recanalization after ischemic stroke, it should be avoided within 14 days of a surgical procedure in favor of other locally directed techniques that carry a significantly lower risk of bleeding at the surgical site. Only in rare circumstances, when these newer modalities are not available and the surgery is minor, should IV rtPA be considered in postoperative patients. The treatment of choice for carefully selected patients with postoperative strokes is IAT with either rtPA or urokinase. IAT may be attempted up to 6 hours after an acute ischemic stroke and may be assisted by mechanical clot disruption/embolectomy in an attempt to improve recanalization rates. In patients who have had a recent craniotomy or any surgery where surgical site bleeding is expected to be massive or difficult to control or where small amounts of bleeding could be life threatening, IAT should be avoided. In these patients, and in patients who present greater than 6 hours but less than 8 hours after their stroke, mechanical thrombolysis/embolectomy may emerge as the only viable treatment option.

Anesthesia and neurocerebral monitoring for aortic dissection.

Patients presenting to the operating room for repair of aortic dissection are challenging in all aspects of their care. Without exception, they require a multidisciplinary team approach. This article will review some of the specific challenges faced by anesthesiologists and neurologists when confronted with such a diagnosis. Specifically, we will discuss the myriad anesthetic issues that present in the preoperative stage and continue into the postoperative period. Neurologic complications during dissection repair result in increased morbidity and mortality. A variety of neurophysiologic monitoring techniques exist that may reduce this risk and will be discussed in detail. Finally, we will present some "controversies in care," emphasizing that our respective fields continue to grow, learn, and improve what information we have on the morbidity and mortality of aortic dissection.

Modified National Institutes of Health Stroke Scale can be estimated from medical records.

BACKGROUND AND PURPOSE: The 15-item National Institutes of Health Stroke Scale (NIHSS) is a quantitative measure of stroke-related neurological deficit with established reliability and validity for use in clinical research. An abridged 11-item modified NIHSS (mNIHSS) has been described that simplifies or eliminates redundant and less reliable items. We aimed to determine whether the mNIHSS could be accurately abstracted from medical records to facilitate retrospective research. METHODS: We selected 39 patient records for which NIHSS scores were formally measured. Handwritten notes from medical records were abstracted, and NIHSS item scores were estimated by 5 raters blinded to actual scores. Estimated scores were compared among raters and with actual measured scores. RESULTS: Interrater reliability for total NIHSS on admission and discharge was excellent, with intraclass correlation coefficients (ICCs) of 0.85 and 0.79, respectively. However, ICCs for 2 items (facial palsy and dysarthria) were poor (<0.40). Interrater reliability for total mNIHSS was slightly greater, with ICCs of 0.87 and 0.89 on admission and discharge, respectively. None of the 11 mNIHSS items had poor reliability, 4 were moderate (ICC, 0.40 to 0.75), and 7 were excellent (ICC >0.75). Sixty-two percent of estimated total NIHSS scores were within 2 points of actual scores and 91% were within 5 points, whereas 70% of estimated total mNIHSS scores were within 2 points and 95% were within 5 points. CONCLUSIONS: The mNIHSS can be estimated from medical records with a high degree of reliability and validity. In retrospective assessment of stroke severity, the mNIHSS performs better than the standard NIHSS and may be easier to use because it has fewer and simpler items.

Fatal subacute cytomegalovirus encephalitis associated with hypogammaglobulinemia and thymoma.

Parathymic syndromes are systemic disorders that occur in association with thymoma. One such parathymic syndrome, hypogammaglobulinemia, was initially identified by Good in 1954 and has been referred to as Good syndrome. Patients with this syndrome develop a variety of recurrent infections due to the associated immunodeficiency. We describe a patient with cytomegalovirus encephalitis associated with Good syndrome and discuss the pathologic findings present on autopsy. The possibility of a cytomegalovirus infection should be considered early in the evaluation of patients with Good syndrome if appropriate clinical symptoms are present.

Interventions for reversing delayed-onset postoperative paraplegia after thoracic aortic reconstruction.

BACKGROUND: Delayed postoperative paraplegia is a recognized complication of thoracic (TAA) or thoracoabdominal aortic aneurysm (TAAA) repair. The purpose of this study was to evaluate the effectiveness of interventions to treat delayed-onset paraplegia. METHODS: Between January 1, 2000 and August 31, 2001, 99 patients underwent surgical repair of TAA, Crawford type I, II, or III TAAA. Standard intraoperative management included distal aortic perfusion and cerebrospinal fluid (CSF) drainage unless contraindicated. Therapeutic interventions to treat delayed paraplegia included lumbar CSF drainage and vasopressor therapy. RESULTS: Three of the 99 patients had paraplegia upon awakening. Delayed-onset paraplegia occurred in 8 patients, 2 of whom had recurrent episodes. In those 8 patients, the initial episode occurred at a median of 21.6 hours (range 6.4 to 110.0 hours) after surgery and the second episode averaged 176 hours after surgery. At the onset of paraplegia, the average mean arterial pressure was 74 mm Hg and CSF pressure was 14 mm Hg. Three of the 8 patients had a functioning CSF catheter at the onset and the other 5 patients had catheters subsequently placed. Therapeutic interventions increased blood pressure to a mean arterial pressure of 95 mm Hg and decreased CSF pressure to 10 mm Hg. Five of the 8 patients with delayed-onset paraplegia made a full neurologic recovery and 3 had partial recovery. CONCLUSIONS: Patients with delayed-onset paraplegia had an increased chance of recovery as compared with those patients in whom paraplegia was diagnosed upon emergence from anesthesia. Acute interventions directed to increase spinal cord perfusion by increasing systemic blood pressure and decreasing CSF pressure were effective for the reversal of delayed onset of paraplegia after TAA or TAAA repair, resulting in an overall 3% incidence of permanent paraplegia and 3% incidence of residual paraparesis.

Susceptibility contrast and arterial spin labeled perfusion MRI in cerebrovascular disease.

PURPOSE: To directly compare dynamic susceptibility contrast (DSC) and continuous arterial spin labeled (CASL) magnetic resonance (MR) perfusion techniques in patients with known cerebrovascular disease, with the goals of identifying possible pitfalls in interpretation and determining potential for a complementary role in this setting. METHODS: DSC and CASL MR perfusion studies were performed and compared in 11 patients with acute and/or chronic cerebrovascular disease. Using an automated segmentation technique, Pearson correlation coefficients were generated for CASL perfusion measurements compared to DSC perfusion maps (time-to-peak [TTP], relative cerebral blood volume [rCBV], cerebral blood flow [rCBF], and mean transit time [MTT]) by hemisphere and vascular territory. RESULTS: TTP maps obtained using DSC perfusion MR correlated best both subjectively and objectively with CASL perfusion MR measurements when all patients studied were considered. If patients with a major transit delay were excluded, DSC rCBF correlated best with CASL CBF measurements. CONCLUSION: There may be a complementary role for CASL and DSC perfusion MR methods in cerebrovascular disease, especially in the setting of a marked transit delay.

Continuous arterial spin labeled perfusion magnetic resonance imaging in patients before and after carotid endarterectomy.

Continuous arterial spin labeling perfusion magnetic resonance imaging (CASL-pMRI) uses magnetically labeled arterial blood water as a tracer to obtain quantifiable measurements of cerebral blood flow (CBF) (mL/100 g-1/min-1). CASL-pMRI was used to assess CBF changes in major vascular distributions in patients (n = 10) prior to and 3 months after carotid endarterectomy (CEA). No significant change in the global baseline CBF before and after CEA was observed in the group as a whole (P = .81). In patients with reduced CBF prior to CEA (< 50 ml/100 g/min), a significant increase in global CBF following CEA was observed. An inverse relationship existed between percent change in CBF after CEA versus baseline CBF within the anterior circulation (r = -.78, P < .05) but not in the posterior distribution (r = .25, P = .63). CASL-pMRI may provide a convenient, inexpensive, noninvasive method for identifying CEA patients at risk for hyperperfusion following carotid revascularization.

No increased risk of spinal cord ischemia in delayed AAA repair following thoracic aortic surgery.

OBJECTIVE: To examine the results of open or endovascular abdominal aortic aneurysm (AAA) repair following prior open or endovascular thoracic aortic surgery. METHODS: A retrospective review of all patients who underwent AAA repair in a delayed fashion following prior thoracic aortic surgery at a single university hospital between 1999 and 2011 was performed. RESULTS: Thirteen patients underwent AAA repair following prior thoracic aortic repair. Mean age was 68.9 ± 6.9 years and 77% (n = 10) were male. Three patients experienced transient delayed-onset spinal cord ischemia (SCI) following initial thoracic surgery. Mean time interval between initial thoracic aortic surgery and subsequent AAA repair was 2.0 ± 1.8 years. Overall rate of SCI and 30-day mortality after delayed AAA repair was 0%. CONCLUSIONS: This series does not demonstrate any evidence of increased risk of perioperative mortality or SCI in patients undergoing delayed AAA repair after prior thoracic aortic surgery.

Effective tool or necessary evil: intraoperative monitoring during thoracic aneurysm repairs.

BACKGROUND: The aim of our study was to analyze the neurophysiologic monitoring method with regard to its potential problems during thoracic and thoracoabdominal aortic open or endovascular repair. Furthermore, preventive strategies to the main pitfalls with this method were developed. METHODS: Between November 2000 and May 2007, in 97 cases, open surgery or endovascular stent graft implantation was performed on the thoracic or thoracoabdominal aorta. Intraoperatively, neurophysiologic motor and somatosensory evoked potentials were monitored. RESULTS: Our cases were divided into four groups: event-free patients with normal potentials (A, 63 cases), those with correlation of modified evoked potentials and neurological outcome (B, 14 cases), those with false-positive or false-negative results (C, 4 cases), and those with medication interaction or technical issues (D, 16 cases). We observed a sensitivity of 93% and a specificity of 96% for the neurophysiologic monitoring. CONCLUSIONS: Monitoring spinal cord function during surgical and endovascular interventions on the thoracic and thoracoabdominal aorta is necessary. It can be made more effective by precisely analyzing the interference factors of the neurophysiologic monitoring method itself. Successful strategies of immediate troubleshooting could be identified.