Open Thoracoabdominal Aortic Aneurysm Research Articles

Reprint of: Renal and visceral protection in thoracoabdominal aortic surgery

Open thoracoabdominal aortic aneurysm (TAAA) repair traditionally carries substantial perioperative morbidity and mortality, primarily from distal aortic ischemia. Advances in surgical techniques, adjuncts, and strategies have greatly improved outcomes. We analyzed outcomes of 1267 open consecutive TAAA repairs between January 2005 and September 2013. We provided cold crystalloid renal perfusion whenever the renal ostia were accessible; according to extent of repair, we selectively used left heart bypass and provided isothermic blood to the celiac axis and superior mesenteric artery. Repair was extensive (Crawford extent I and II) in 717 cases (57%). Left heart bypass was used in 645 (51%) cases, cold crystalloid renal perfusion in 987 (78%), and isothermic visceral perfusion in 318 (25%). Additional patient-specific surgical adjuncts included endarterectomy of renal or visceral vessels, open stent placement within these vessels, or use of both techniques; at least one was used in 447 repairs (35%). Thirty-day survival was 95% (1198/1267); overall operative mortality was 8% (104/1267). Acute renal dysfunction occurred in 155 (12%), renal failure requiring hemodialysis at hospital discharge in 84 (7%), and bowel ischemia in 9 (<1%). Extent II and III TAAA repairs carried the highest risks of postoperative renal dysfunction and renal failure requiring hemodialysis at hospital discharge. Contemporary protective strategies allow open TAAA repair with substantially fewer renal and visceral ischemic complications. Although bowel ischemia is uncommon, renal failure remains a concern, especially in extent II and extent III TAAA repairs. Additional studies are needed to identify and improve renal protection strategies.

Reprint of: Reoperations on the total aortic arch in 119 patients: Short- and mid-term outcomes, focusing on composite adverse outcomes and survival analysis

To determine the preoperative and perioperative risk factors that significantly predict adverse outcomes after total arch replacement in patients with previous proximal aortic surgery and to analyze patient survival. We performed univariate analysis and logistic regression on data extracted from a prospectively maintained database for 119 patients who had undergone total arch operations during a 7.5-year period. All patients had undergone previous proximal aortic surgery. The adverse outcome was defined as a single composite endpoint comprising operative mortality, permanent neurologic deficit, and renal failure necessitating permanent hemodialysis. The incidence of the composite endpoint was 13.5% (16 of 119 patients). The univariate predictors were preoperative pulmonary disease (P=.010), cardiac ischemia time (P=.032), and cardiopulmonary bypass (CPB) time (P=.073). On multivariate analysis, the following were predictors of the composite endpoint: preoperative pulmonary disease (P=.036), CPB time (P=.039), concomitant coronary artery bypass (P=.0057), previous aortic valve replacement (P=.027), and previous thoracoabdominal aortic aneurysm surgery (P=.057). Multivariate analysis showed that the CPB time predicted mortality (P=.0044), and previous thoracoabdominal aortic aneurysm surgery predicted stroke (P=.034). The overall survival was 85.3% during a median follow-up of 4.76 years (95% confidence interval, 4.2-5.1). Aortic arch reoperations, although technically demanding, can produce acceptable results. Preoperative pulmonary disease, CPB time, and concomitant coronary artery bypass predicted an adverse outcome. The CPB time predicted mortality, and previous thoracoabdominal aortic surgery predicted stroke.

Effect of coenzyme Q₁₀ on spinal cord ischemia-reperfusion injury.

Spinal cord ischemia remains a serious complication of thoracoabdominal aortic aneurysm surgery. Coenzyme Q10, a potent antioxidant, has been reported to exert a neuroprotective effect. In the present study, we evaluated the effect of coenzyme Q10 pretreatment on spinal cord ischemia-reperfusion injury. Male Sprague-Dawley rats were treated with either 300 mg/kg coenzyme Q10 (CoQ10 group, n = 12) or saline (control and sham groups, n = 12 for each group) for 5 days before ischemia. Spinal cord ischemia was induced in the control and CoQ10 groups. Neurological function was assessed using the Basso-Beattie-Bresnahan (BBB) motor rating scale until 7 days after reperfusion, and then the spinal cord was harvested for histopathological examinations and an evaluation of malondialdehyde level. On post-reperfusion Day 1, the CoQ10 group showed higher BBB scores compared with those in the control group, although the difference was not significant. However, on Day 2, the CoQ10 group showed a significantly higher BBB score than the control group (14.0 [10.3-15.0] vs 8.0 [5.0-9.8], median [IQR], respectively; p = 0.021), and this trend was maintained until Day 7 (17.5 [16.0-18.0] vs 9.0 [6.5-12.8], respectively; p < 0.001). Compared with the control group, the CoQ10 group had more normal motor neurons (p = 0.003), fewer apoptotic changes (p = 0.003) and a lower level of tissue malondialdehyde (p = 0.024). Pretreatment with 300 mg/kg coenzyme Q10 resulted in significantly improved neurological function and preservation of more normal motor neurons.

Early outcomes and perioperative risk assessment in elective open thoracoabdominal aortic aneurysm repair: An analysis of national data over a five-year period.

Open surgical repair of thoracoabdominal aortic aneurysms remains associated with significant morbidity and mortality. We sought to analyse multicentre national data on early outcomes of open surgical thoracoabdominal aortic aneurysm repair. Patients who underwent open repair of thoracoabdominal aortic aneurysm from 2005 to 2010 were identified from the National Surgical Quality Improvement Program database. The primary endpoint was mortality at 30 days. Patient demographics, clinical variables, and intraoperative parameters were analysed by univariate and multivariate logistic regression methods to identify risk factors for mortality. Of the 682 elective repairs, 30-day outcomes of elective repairs were: 10.0% mortality, 21.6% surgical complications, 42.2% pulmonary complications, 17.2% renal complications, 12.9% cardiovascular complications, 19.2% septic complications, and 6.6% wound complications. Multivariate logistic regression analysis showed that age, ASA-class IV, dependent functional status prior to surgery, and operation time are independent risk factors for mortality. Our study found a higher rate of mortality nationwide, as compared to several previous single center studies.

Spinal Near-Infrared Spectroscopy Measurements During and After Thoracoabdominal Aortic Aneurysm Repair: A Pilot Study

Near-infrared spectroscopy (NIRS) is a noninvasive technique that allows continuous monitoring of regional hemoglobin oxygen saturation (rSo2). We evaluated its application to survey oxygenation of the spinal cord region during open thoracoabdominal aortic aneurysm (TAAA) repair and postoperatively in the intensive care unit (ICU). We also validated its association with motor-evoked potential (MEP) monitoring during the operation. The rSo2 curves of 15 patients (8 men; mean age, 64.2 ± 7.7 years) were measured continuously with NIRS at spinal cord levels of the thoracic vertebrae T3 (optode 1, reference spot) and T12 (optode 2) during open TAAA repair. T12/T3 ratios were calculated. NIRS measurements were continued in the intensive care unit and stopped 24 hours after the operation. MEP monitoring was performed in all patients during the procedure. No clinical signs of spinal cord ischemia were documented in any of the patients. Continuous NIRS measurements were successfully performed in all patients during and after the operation. T12/T3 ratios were significantly lower in the MEP ratios that were less than 50% compared with the MEP ratios that were 50% or higher (p= 0.037). NIRS is an easily applicable noninvasive tool for continuous surveillance of oxygenation of the spinal cord region during TAAA repair and postoperatively in the intensive care unit. The rSo2 curves provide useful information concerning hemodynamic changes in oxygenation of the spinal cord region and might contribute to early detection of spinal cord ischemia. Further investigation is needed before broad clinical implementation.

Contemporary outcomes of open repair of thoracoabdominal aortic aneurysm in young patients.

BackgroundEndovascular technology now permits total endovascular thoracoabdominal aortic aneurysm (TAAA) repair with high volume centres reporting encouraging results. The long-term durability of such stent grafts is unknown, leading to concerns regarding their use in younger patients. This study reports contemporary outcomes of open repair in young patients.MethodsOutcomes for patients age 60 or younger undergoing open TAAA repair between June 1999 and August 2013 with prospective collected data were analysed retrospectively.ResultsThirty-seven patients (31 men, 84%) with a median age of 56 (range 22–60) were identified with a median TAAA diameter of 6.9 cm (range 5.6-11). Aneurysm aetiology included degenerative change (18), dilation of chronic dissection (10), connective tissue disease (7) and mycotic degeneration (2). Crawford Type IV TAAA were most commonly treated (17), followed by Type II (10), Type III (7) and Type I (3). Two (5%) patients died in hospital, one from multiple organ failure and one from respiratory failure. Three patients (8%) developed temporary paraplegia, all of whom made a complete recovery and 4 (11%) patients required temporary renal replacement therapy. Median critical care stay was 5 days (range 2–28) with an in-hospital stay of 14 days (range 7–83). During a median follow-up of 72 months (range 13–171), no patient subsequently required any further aneurysm related surgical or radiological intervention. The mean (SEM) survival time was 138.5 (11) months. The 5 year survival was 79.7% (8.3) including early deaths, with no aneurysm related complications.ConclusionsThe outcome of open TAAA repair in patients aged less than 60 years is favorable. It is against these results that evolving endovascular interventions must be compared.Electronic supplementary materialThe online version of this article (doi:10.1186/s13019-014-0195-4) contains supplementary material, which is available to authorized users.

Complications of spinal fluid drainage in thoracic and thoracoabdominal aortic aneurysm surgery in 724 patients treated from 1987 to 2013.

To study complications from spinal fluid drainage in open thoracic/thoracoabdominal and thoracic endovascular aortic aneurysm repairs to define risks of spinal fluid drainage. Retrospective, prospectively maintained, institutionally approved database. Single institution university center. 724 patients treated from 1987 to 2013 INTERVENTIONS: The authors drained spinal fluid to a pressure≤6 mmHg during thoracic aortic occlusion/reperfusion in open and ≤8 mmHg after stent deployment in endovascular procedures. Low pressure was maintained until leg strength was documented. If bloody fluid appeared, drainage was stopped. Head computed tomography (CT) and, if indicated, spine CT and magnetic resonance imaging (MRI) were performed for bloody spinal fluid or neurologic deficit. Spinal fluid drainage was studied for bloody fluid, CT/MRI-identified intracranial and spinal bleeding, neurologic deficit, and death. Seventy-three patients (10.1%) had bloody fluid; 38 (5.2%) had intracranial blood on CT. One patient had spinal epidural hematoma. Higher volume of fluid drained and higher central venous pressure during proximal clamping were associated with intracranial blood. Most patients with intracranial blood were asymptomatic. Six patients had neurologic deficits: of the 6, 3 died (0.4%), 1 (0.1%) had permanent hemiparesis, and 2 recovered. Three of the six deficits were delayed, associated with heparin anticoagulation. 10% of patients had bloody spinal fluid; half of these had intracranial bleeding, which was almost always asymptomatic. In these patients, immediately stopping drainage and correcting coagulopathy may decrease the risk of serious complications. Neurologic deficit from spinal fluid drainage is uncommon (0.8%), but has high morbidity and mortality.

Contemporary outcomes of open thoracoabdominal aortic aneurysm repair in octogenarians

We sought to evaluate our contemporary outcomes with open thoracoabdominal aortic aneurysm (TAAA) repair in octogenarians to determine whether open TAAA repair is a viable option, with acceptable risk, in this elderly cohort. We analyzed clinical data from 1267 enrolled patients who underwent open TAAA repair between 2003 and 2013. Eighty-eight patients (7%) were octogenarians (median age, 82 years; range, 80-92 years) and 1179 were 79 years of age or less. Aneurysm rupture was more common in octogenarians (14% vs 4.7%, P=.001), whereas aortic dissections predominated in younger patients (43.9% vs 13%, P<.001). Octogenarians had higher rates of visceral-branch endarterectomy/stenting (58% vs 33.5%, P<.001), adverse postoperative outcomes (36% vs 15.3%, P<.001), operative mortality (26% vs 6.9%, P<.001), and prolonged hospital stay (P=.004). Among octogenarians, preoperative aortic dissection was most commonly associated with extent I repair (42% vs <10% for other extents, P<.001). Extent II repairs most frequently necessitated concomitant visceral-branch procedures and carried the highest risk of mortality (62%). Extent I and III repairs carried intermediate operative risk, and extent IV repairs posed the least risk (11%). Multivariate modeling analysis identified extent II TAAA (P=.001; odds ratio, 11.6), presence of concomitant dissection (P=.02; odds ratio, 5.6), and aneurysm rupture (P=.02; odds ratio, 5.7) as independent predictors of operative mortality in octogenarians. Open extent II TAAA repair carries significant risk for octogenarians; extent I, III, and IV repairs incur more reasonable postoperative risk. Although TAAA repair should not be denied to octogenarians based solely on age, extensive TAAA repair should be performed with caution.

Reoperations on the total aortic arch in 119 patients: Short- and mid-term outcomes, focusing on composite adverse outcomes and survival analysis

To determine the preoperative and perioperative risk factors that significantly predict adverse outcomes after total arch replacement in patients with previous proximal aortic surgery and to analyze patient survival. We performed univariate analysis and logistic regression on data extracted from a prospectively maintained database for 119 patients who had undergone total arch operations during a 7.5-year period. All patients had undergone previous proximal aortic surgery. The adverse outcome was defined as a single composite endpoint comprising operative mortality, permanent neurologic deficit, and renal failure necessitating permanent hemodialysis. The incidence of the composite endpoint was 13.5% (16 of 119 patients). The univariate predictors were preoperative pulmonary disease (P = .010), cardiac ischemia time (P = .032), and cardiopulmonary bypass (CPB) time (P = .073). On multivariate analysis, the following were predictors of the composite endpoint: preoperative pulmonary disease (P = .036), CPB time (P = .039), concomitant coronary artery bypass (P = .0057), previous aortic valve replacement (P = .027), and previous thoracoabdominal aortic aneurysm surgery (P = .057). Multivariate analysis showed that the CPB time predicted mortality (P = .0044), and previous thoracoabdominal aortic aneurysm surgery predicted stroke (P = .034). The overall survival was 85.3% during a median follow-up of 4.76 years (95% confidence interval, 4.2-5.1). Aortic arch reoperations, although technically demanding, can produce acceptable results. Preoperative pulmonary disease, CPB time, and concomitant coronary artery bypass predicted an adverse outcome. The CPB time predicted mortality, and previous thoracoabdominal aortic surgery predicted stroke.

Renal and visceral protection in thoracoabdominal aortic surgery

Open thoracoabdominal aortic aneurysm (TAAA) repair traditionally carries substantial perioperative morbidity and mortality, primarily from distal aortic ischemia. Advances in surgical techniques, adjuncts, and strategies have greatly improved outcomes. We analyzed outcomes of 1267 open consecutive TAAA repairs between January 2005 and September 2013. We provided cold crystalloid renal perfusion whenever the renal ostia were accessible; according to extent of repair, we selectively used left heart bypass and provided isothermic blood to the celiac axis and superior mesenteric artery. Repair was extensive (Crawford extent I and II) in 717 cases (57%). Left heart bypass was used in 645 (51%) cases, cold crystalloid renal perfusion in 987 (78%), and isothermic visceral perfusion in 318 (25%). Additional patient-specific surgical adjuncts included endarterectomy of renal or visceral vessels, open stent placement within these vessels, or use of both techniques; at least one was used in 447 repairs (35%). Thirty-day survival was 95% (1198/1267); overall operative mortality was 8% (104/1267). Acute renal dysfunction occurred in 155 (12%), renal failure requiring hemodialysis at hospital discharge in 84 (7%), and bowel ischemia in 9 (<1%). Extent II and III TAAA repairs carried the highest risks of postoperative renal dysfunction and renal failure requiring hemodialysis at hospital discharge. Contemporary protective strategies allow open TAAA repair with substantially fewer renal and visceral ischemic complications. Although bowel ischemia is uncommon, renal failure remains a concern, especially in extent II and extent III TAAA repairs. Additional studies are needed to identify and improve renal protection strategies.

Current management and outcome of chronic type B aortic dissection: results with open and endovascular repair since the advent of thoracic endografting.

Thoracic endovascular aortic repair (TEVAR) has become the preferred treatment for chronic type B aortic dissection (CTBAD) at our institution. However, it remains incapable of treating all patients with CTBAD. The present study aims to review our contemporary results with open and endovascular CTBAD repairs since the advent of thoracic endografting. The records of all patients undergoing index repair of CTBAD (chronic DeBakey type IIIA, IIIB and repaired type I) at our institution between June 2005 and December 2013, were retrospectively reviewed. A total of 107 patients underwent CTBAD repair, of whom 70% (n=75) underwent endovascular-based procedures [44 TEVAR, 27 hybrid arch and four hybrid thoracoabdominal aortic aneurysm (TAAA) repair] and 30% (n=32) underwent open procedures (nine open descending and 23 open TAAA). Connective tissue disease (CTD), prior aortic surgery and DeBakey dissection type were strongly associated with the choice of operation. The rates of stroke, paraplegia and operative mortality following endovascular-based repairs were 0%, 0% and 4% (n=3), respectively. Adverse neurologic events were higher following open repair, and rates of stroke, paraplegia, and operative mortality were 16% (n=5), 9% (n=3), and 6% (n=2), respectively. However, 1- and 5-year survival rates were similar for endovascular-based repairs (86% and 65%, respectively), and open repairs (88% and 79%, respectively). Over a median follow-up interval of 34 months, the rate of descending aortic reintervention was 24% (n=18) following endovascular-based repairs and 0% following open repairs (P=0.001). Forty-four percent (n=8) of descending aortic reinterventions were required to treat stent graft complications (five endoleak, two stent graft collapse and one stent graft-induced new entry tear) and the remainder were required to treat metachronous pathology (n=2) or progressive aneurysmal disease related to persistent distal fenestrations (n=8). Endovascular repair of CTBAD was associated with excellent procedural and survival outcomes, but at the expense of further reinterventions. Open repair remains relevant for patients who are not candidates for endovascular repair and was associated with higher procedural morbidity but similar overall survival and fewer reinterventions.

Open repair in chronic type B dissection with connective tissue disorders.

Aneurysms associated with inherited connective tissue disorders (CTD) constitute a specific but important issue in thoracoabdominal aortic aneurysm (TAAA) surgery. In this respect, Marfan syndrome and Ehlers-Danlos syndrome (EDS) type IV represent the most significant disorders causing aneurysmal dilatation of the thoracic aorta. Marfan syndrome typically causes aortic root dilatation, aortic valve insufficiency and dissection, whereas EDS can generate dissection or aneurysm formation in almost every major artery, including the thoracoabdominal aorta. The majority of patients with Marfan syndrome first suffer from ascending thoracic aortic aneurysm, which requires surgical repair. Marfan patients are significantly younger than patients with degenerative aneurysms (1). Therefore, the physical condition of younger Marfan patients is much better than the non-Marfan group (2). Despite this, there is a higher incidence of dissection and rupture during TAAA surgery in Marfan patients and the recommended threshold for repair is thus an aneurysm diameter of 5.0-5.5 cm (3). The second most common cause of TAAA formation is chronic type B dissection. In patients having surgery for TAAA, up to 24% suffer from chronic dissections (4). Conversely, 20-40% of all patients with aortic dissections will require subsequent aortic replacement for aneurysmal degeneration, irrespective of initial medical or surgical treatment at the time of acute presentation (5). The presence of blood flow in the false lumen is the most significant risk factor for increased aortic diameter, with a mean growth rate of 3.3 mm/year (as compared to 1.4 mm/year diameter shrinkage in patients with a thrombosed false lumen). Position along the aorta also influences growth rate with thoracic aortic aneurysms expanding significantly faster than AAAs (4.1 and 1.2 mm/year, respectively) (6). The growth rate of post-dissection aneurysms can be comparable to that of degenerative thoracic aneurysms or faster. Taking these considerations into account, the combination of chronic dissection, aneurysm formation and connective tissue disease poses major challenges regarding indication for treatment, choice of treatment, and clinical outcome.

Use of a novel hybrid vascular graft for sutureless revascularization of the renal arteries during open thoracoabdominal aortic aneurysm repair

The aim of this study was to assess the safety and short-term effectiveness of a novel hybrid vascular graft used to address renal revascularization during open thoracoabdominal aortic aneurysm (TAAA) repair, performing a sutureless distal anastomosis. Between 2012 and 2013, 25 patients (16 men; mean age, 66 ± 8 years) underwent revascularization of one (24 patients) or both (one patient) renal arteries with the Gore Hybrid Vascular Graft (GHVG; W. L. Gore and Associates, Flagstaff, Ariz) during open TAAA repair. Specific indications included remote location of the ostium of the renal artery, severe atherosclerotic wall degeneration, focal dissection, and stenosis. All surviving patients underwent computed tomography angiography and follow-up visit at 1 month. Preoperative characteristics, intraoperative data, and short-term results were compared with those of 49 concurrent TAAA patients operated on within the same period by standard renal revascularization (SRR) techniques. All GHVG target renal vessels (26 of 26) were successfully revascularized without technical concerns. No significant differences were found between GHVG and SRR groups in preoperative and intraoperative data, except for a relative prevalence of aortic dissection (28% vs 6%; P = .026) and renal artery stenosis (44% vs 12%; P = .003) in the GHVG group and for intraoperative renal bare stenting that was predominantly used in the SRR group (12% vs 28%; P = .036). The 30-day mortality was 4% in both groups. Postoperative acute renal failure (doubling of creatinine level and creatinine level >3.0 mg/dL) occurred in two GHVG patients (8%) and seven SRR patients (14%; P = NS). Perioperative peak decrease of estimated glomerular filtration rate was lower in the GHVG group (26 ± 18 mL/min/1.73 m(2) vs 37 ± 22 mL/min/1.73 m(2); P = .034). At 1-month computed tomography angiography, renal artery patency was 92% for the GHVG vessels, 91% for the contralateral to GHVG renal vessels, and 92% for the SRR group arteries. No GHVG-related complications requiring reintervention or cases of new-onset renal failure requiring dialysis were observed at follow-up. Renal revascularization during open TAAA repair by the GHVG with distal sutureless anastomosis is feasible, especially in cases of aortic dissection, remote location of the renal vessel, and severe atherosclerotic disease of the ostium. Short-term results are satisfactory, at least comparable to those of SRR. Larger series and longer follow-up are needed to assess clinical advantages and durability of this new device.

47. Monitoring of motor evoked potentials during thoracoabdominal aortic aneurysm repair

Spinal cord ischemia is one of the most serious complications of thoracoabdominal aortic aneurysm surgery. Hypotermia, cerebrospinal fluid drainage and pressure monitoring, reimplantation of segmental arteries and staged clamping are usual methods of spinal cord protection. We use electrophysiological monitoring of motor evoked potentials (MEPs) to measure a functional status of the thoracolumbar spinal cord during thoracoabdominal aortic surgery. Between May 2011 and May 2013, MEPs monitoring-assisted thoracoabdominal repair was performed in 14 patients. Stable MEPs were reproducible in 10 of 14 patients (71%). Nine of them displayed no neurological deficit after postoperative awakening. One patient suffered light hemiparesis due to brain ischemia. Bilateral MEPs loss occurred in 4 of 14 patients. Two of them recovered after spinal-cord protecting interventions with no neurological deficit. One patient died early after surgical intervention in the ICU and it was not possible to assess neurological functions in this patient. The remaining patient suffered left-sided hemiparesis, which improved to a very light deficit within several days after the procedure. There was no case with paraparesis or paraplegia in our group. Neurophysiological monitoring of spinal cord function is necessary to detect spinal cord ischemia. An advantage of MEPs comparing to the somatosensory evoked potentials (SSEPs) is rapid response to spinal malperfusion and corrective steps to prevent or reduce the extent of paraplegia and paraparesis can be taken with little delay. False positive results, detected in two patients of our group, are well known and described in literature and were not detrimental for the patients.

The use of neuromonitoring in descending and thoraco-abdominal aortic aneurysm surgery Literature Review

Abstract Without surgical repair thoracic aortic aneurysms are a lethal disease with poor prognosis. An extensive major operation is required to correct an aneurysm that involves the descending or thoracoabdominal aorta. Particular considerations must be made to protection of all abdominal organs, the brain and the spinal cord which are all at risk. Consequently there is a risk that these patients post operatively wake up paraplegic from spinal cord ischaemia due to the nature of the surgery. Certain techniques have evolved that have considerably reduced this risk. Neuromonitoring is a technique that can provide an intraoperative assessment of the integrity of the spinal cord through stimulation of nervous pathways and detection in either peripheral muscles or the brain cortex. In theory this can alert the surgical team to impending spinal cord ischaemia and change the management of this patient to prevent paraplegia. However, there is much ambiguity surrounding its use, with no conclusive evidence to prove this technique effectively reduces the rates of paraplegia. This literature review will assess the current methods of neuromonitoring in thoracoabdominal aneurysm repair.

Thoracic and thoracoabdominal aortic repair under regional spinal cord hypothermia

Spinal cord deficits are devastating complications after surgery for thoracic and thoracoabdominal aortic aneurysms. We developed a regional spinal cord cooling system using an epidural catheter containing cold saline within an isolated counter-current lumen to prevent such complications and reviewed the clinical results. We enrolled 37 patients with thoracic (n = 13) and thoracoabdominal (n = 24) aortic aneurysms that were repaired using the regional spinal cord cooling system under mild hypothermia with a partial femoro-femoral bypass. Although 2 patients died before hospital discharge (hospital mortality, 5.4%), none developed neurological deficits such as paraplegia or paraparesis. The outcomes of surgery for thoracic and thoracoabdominal aortic aneurysms under regional spinal cord hypothermia using a custom-designed epidural catheter were excellent. Although our patient cohort was small, the results indicate that our technique might help to improve the outcomes of thoracic and thoracoabdominal aortic repair.

Complications to Cerebrospinal Fluid Drainage and Predictors of Spinal Cord Ischemia in Patients With Aortic Disease Undergoing Advanced Endovascular Therapy

To study the complications after cerebrospinal fluid (CSF) drainage and predictors of spinal cord ischemia (SCI) after advanced endovascular therapy with CSF drainage for complex aortic disease. Between 2009 and 2012, 88 attempts of CSF drainage insertions/84 operations/83 patients, of the 658 operations for aortoiliac diseases, were performed. Indications for therapy were aortic dissection (n = 13) and aortic aneurysm (n = 70), of whom 38 had thoracoabdominal aortic aneurysm (TAAA). In all, 10 had ruptured aorta. The CSF drainages were inserted preoperatively (n = 75) and postoperatively (n = 9). In all, 14 CSF drainages were nonfunctioning. The SCI was present in 29 patients, transient/permanent in 12/17. Intraoperative circulatory instability (P = .001) and operation for TAAA, type II (P = .036), were associated with SCI. Meningitis (n = 1), epidural (n = 1), and subdural (n = 2) hematoma and needle-mediated paresis in 1 leg (n = 1) occurred after CSF drainage. Complication to CSF drainage occurred too frequently in this selected group of patients with high rate of SCI.

Efficacy of iloprost and montelukast combination on spinal cord ischemia/reperfusion injury in a rat model

BackgroundThe thoracic or thoracoabdominal aortic aneurysm surgery may cause spinal cord ischemia because of aortic cross-clamping and may result in severe postoperative complications caused by spinal cord injury. Ischemia/reperfusion injury may directly or indirectly be responsible for these complications. In this study we sought to determine whether combination of iloprost and montelukast can reduce the ischemia/reperfusion injury of spinal cord in a rat model.MethodsMedulla spinalis tissue concentrations of interleukin-6 (IL-6), myeloperoxidase (MPO) and heat shock protein 70 (HSP-70) were determined in 3 groups of Spraque Dawley rats: control group (operation with cross clamping and intraperitoneal administration of 0.9% saline, n = 7), sham group (operation without cross clamping, n = 7), and study group (operation with cross-clamping and intraperitoneal administration of iloprost (25 ng/kg) and montelukast (1 mg/kg), n = 7). The abdominal aorta was clamped for 45 minutes, with a proximal (just below the left renal artery) and a distal (just above the aortic bifurcation) clip in control and study groups. Hindlimb motor functions were evaluated at 6, 12, 24, and 48 hours using the Motor Deficit Index score. All rats were sacrificed 48 hours after the procedure and spinal cord tissue levels of myeloperoxidase, interleukin-6, and heat shock protein (HSP-70) were evaluated as markers of oxidative stress and inflammation. Histopathological analyses of spinal cord were also performed.ResultsThe tissue level of HSP-70 was found to be similar among the 3 groups, however, MPO was highest and IL-6 receptor level was lowest in the control group (p = 0.007 and p = 0.005; respectively). In histopathological examination, there was no significant difference among the groups with respect to the neuronal cell degeneration, edema, or inflammation, but vascular congestion was found to be significantly more prominent in the control group than in the sham or in the study group (p = 0.05). Motor deficit index scores at 24 and 48 hours after ischemia were significantly lower in the study group than in the control group.ConclusionThis study suggests that combined use of iloprost and montelukast may reduce ischemic damage in transient spinal cord ischemia and may provide better neurological outcome.

Hybrid procedures for thoracoabdominal aortic aneurysms and dissections

Background Hybrid procedures including debranching of visceral and renal arteries followed by endovascular exclusion of the thoracoabdominal aortic aneurysm (TAAA) have recently been proposed as a less invasive alternative to conventional TAAA surgery. This study aimed to evaluate the immediate and long-term outcomes of hybrid procedures for TAAA in high-risk patients. Methods Between September 1998 and May 2012, 32 high-risk TAAA patients (five females, median age 61.5 years) underwent hybrid procedures at a single institution. Simultaneous approach and staged approach were performed on the basis of patients' conditions. Follow-up computed tomography angiography (CTA) was routinely performed before discharge and at 6, 12 months and annually thereafter. Results Procedural success was achieved in all cases. The median hospital stay was (21.5P2.3) days, and the median procedure time was (420231) minutes. Blood loss averaged (21003261) ml. A total of 124 visceral artery bypasses was performed. Two patients (6.3%) died within 30 days. One patient exhibited complete paraplegia (3.1%). The visceral graft patency was 96.1% at 3 years. All-cause survival rates were 93.8%, 87.5%, 81.3% and 53.1% at 1, 2, 3 and 5 years, respectively. No patient died due to aortic events. The freedom rates from aortic events were 96.9%, 93.6%, 87.5%, 68.8% at 1, 2, 3 and 5 years, respectively. Conclusions The results of visceral hybrid repair for high-risk patients with complex TAAAs are encouraging. However, the procedure is still a significant physiological insult to patients. Until branched and fenestrated endovascular repair become more common, hybrid procedure will continue to have a role in high-risk patients.

In-hospital and postdischarge venous thromboembolism after vascular surgery

Recent single-center reports demonstrate a high (up to 10%) incidence of postoperative venous thromboembolism (VTE) after major vascular surgery. Moreover, vascular patients rarely receive prolonged prophylaxis despite evidence that it reduces thromboembolic events after discharge. This study used a national, prospective, multicenter database to define the incidence of overall and postdischarge VTE after major vascular operations and assess risk factors associated with VTE development. Patients with VTE who underwent elective vascular procedures (n= 45,548) were identified from the 2007-2009 National Surgical Quality Improvement Program (NSQIP) database. The vascular procedures included carotid endarterectomy (CEA; n= 20,785), open thoracoabdominal aortic aneurysm (TAAA) repair (n= 361), thoracic endovascular aortic repair (TEVAR; n= 732), open abdominal aortic (OAA) surgery (n= 6195), endovascular aneurysm repair (EVAR; n= 7361), and infrainguinal bypass graft (BPG; n= 10,114). Univariable and multivariable analyses were performed to ascertain risk factors associated with VTE. VTE was diagnosed in 187 patients (1.3 %) who underwent aortic surgery, with TAAA repair having the highest rate of VTE (4.2%), followed by TEVAR (2.2%), OAA surgery (1.7%), and EVAR (0.7%). In this subgroup, pulmonary embolisms (PE) were diagnosed in 52 (0.4%) and deep venous thrombosis (DVT) in 144 (1%). VTE rates were 1.0% and 0.2% for patients who underwent a BPG or CEA, respectively. Forty-one percent of all VTEs were diagnosed after discharge. The median (interquartile range) number of days from surgery to PE and DVT were 10 (5-15) and 10 (4-18), respectively. On multivariable analyses, type of surgical procedure, totally dependent functional status, disseminated cancer, postoperative organ space infection, postoperative cerebrovascular accident, failure to wean from ventilator ≤48 hours, and return to the operating room were significantly associated with development of VTE. In those experiencing a DVT or PE, overall mortality increased from 1.5% to 6.2% and from 1.5% to 5.7% respectively (P< .05 for both). Postoperative VTE is associated with the type of vascular procedure and is highest after operations in the chest and abdomen/pelvis. About 40% of VTE events in elective vascular surgery patients were diagnosed after discharge, and the presence of VTE was associated with a quadrupled mortality rate. Future studies should evaluate the benefit of DVT screening and postdischarge VTE prophylaxis in high-risk patients.