Long-term survival after descending thoracic and thoracoabdominal aortic aneurysm repair.

OBJECTIVE: Patients with descending thoracic aortic aneurysms (dTAA) or thoracoabdominal aortic aneurysms (TAAA) often have a variety of medical comorbidities. Those that are deemed acceptable for intervention undergo complicated repairs with good early outcomes. The purpose of this study was to identify variables that were associated with mortality over time. METHODS: This was a retrospective review of a prospectively maintained database at our institution from 1983 to 2015. Patients were included if they underwent open or endovascular repair for dTAA or TAAA. Patients were excluded if they were intervened on for traumatic transections. The primary outcome for the study was long-term survival. Secondary outcomes included aortic-related mortality. We had mortality and survival data on all patients. RESULTS: A total of 946 patients met our study criteria with a median follow-up of 102.8 months (interquartile range [IQR], 58.9-148.2 months). The median age of the cohort was 71 years (IQR, 63-77 years) with the majority of patients being male (58.1%). The extent of TAAA pathology was as follows: type I (14.2%), type II (21.2%), type III (17.1%), type IV (26.2%), and dTAA (21.2%). A total of 147 patients (15.5%) had a prior dissection. The median diameter of aneurysm was 6.4 cm (IQR, 6.0-7.0 cm). A total of 158 patients (16.7%) underwent endovascular repair over the study period. Variables associated with mortality over time were age, surgical era, acute pathology, dissection, preoperative creatinine, and type IV TAAAs. In addition, experiencing the following complications in the postoperative period was associated with mortality over time: neurological, cardiac, and pulmonary. Aortic-related mortality was 2.1% (n = 20) over the study period. Patients who underwent endovascular repair for acute conditions had better long-term survival when compared with open repair. However, there were no differences in long-term survival between open and endovascular repair for nonacute cases. In addition, repair in the more modern era was associated with improved survival. CONCLUSIONS: TAAAs can be repaired with reasonable perioperative mortality rates. Once patients undergo repair of their aneurysm, aortic-related mortality remains low. The addition of endovascular options has dramatically changed management of patients with dTAA and TAAA. Further, endovascular repair was associated with decreased perioperative mortality and significantly increased long-term survival in acute patients. Patients undergoing TAAA repair are generally considered high risk and therefore require extensive long-term follow-up for management of their comorbidities and complications, because these are the main contributors to mortality over time.

Postoperative renal failure in thoracoabdominal aortic aneurysm repair with simple cross-clamp technique and 4°C renal perfusion.

OBJECTIVE: Acute renal failure (ARF) is reported in up to 12% of patients after thoracoabdominal aortic aneurysm (TAAA) repair with assisted circulation. ARF increases mortality, reduces quality of life, and increases length of hospital stay. This study analyzes ARF after TAAA repair done without assisted circulation. METHODS: A retrospective analysis of all patients treated for TAAA from 2000 to 2013 was performed using a concurrently maintained, institutionally approved database. All surgeries used simple cross-clamp technique, with moderate systemic hypothermia (32°-33°C) and renal artery perfusion with 4°C solution. Serum creatinine concentration was measured preoperatively and 1 day, 3 days, 7 days, and 30 days after surgery, and Cockcroft-Gault estimated glomerular filtration rate (eGFR) was calculated. Kidney injury was classified by RIFLE (Risk, Injury, Failure, Loss of kidney function, End-stage renal disease) eGFR criteria. Changes in eGFR, kidney injury, ARF, dialysis, length of stay, mortality, and risk factors for ARF were analyzed with SAS-JMP software (SAS Institute, Cary, NC) for univariate analysis and multivariate modeling. RESULTS: From 2000 to 2013, 455 patients had TAAA surgery; 116 (25.5%) were acute. Mean preoperative eGFR was 62.3 mL/min. Mean renal ischemia time was 58.9 minutes. Eighteen patients (4%) had ARF; nine (2%) required temporary dialysis, and three (0.66%) required permanent dialysis. In univariate analysis, age, renal ischemia time, acuity, baseline eGFR, previous aortic surgery, surgical blood loss, and return to operating room for bleeding complications were significant for ARF (P < .05). Sex, aneurysm extent by Crawford type, cardiac index and mean arterial pressure after reperfusion, and use of loop diuretics were not significant for ARF. In a stepwise deletion model, acute (P = .0377), previous aortic surgery (P = .0167), return to operating room (P = .0213), and age (P = .0478) were significant for ARF. Surgical blood loss (P = .0056) and return to operating room (P = .0024) were significant for postoperative dialysis in multivariate analysis. Only surgical blood loss was significant for permanent dialysis in a multivariate model (P = .0331). CONCLUSIONS: Very low ARF after TAAA repair can be achieved by simple cross-clamp technique with moderate systemic hypothermia and profound renal cooling. Age, preoperative eGFR, previous aortic surgery, return to operating room, and surgical blood loss were significant for ARF. Return to operating room for bleeding and surgical blood loss were significant for dialysis. Baseline eGFR <30 mL/min and postoperative dialysis were significant for mortality. Most patients with ARF, even those with temporary dialysis after TAAA repair, recover renal function to near preoperative levels.

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

OBJECTIVE: To study complications from spinal fluid drainage in open thoracic/thoracoabdominal and thoracic endovascular aortic aneurysm repairs to define risks of spinal fluid drainage. DESIGN: Retrospective, prospectively maintained, institutionally approved database. SETTING: Single institution university center. PARTICIPANTS: 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. MEASUREMENTS AND MAIN RESULTS: 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. CONCLUSIONS: 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.

Evolution in management of adolescent blunt aortic injuries--a single institution 22-y experience.

BACKGROUND: In children, severe, life-threatening traumatic injuries of the thoracic aorta can be seen after motor vehicle collisions (MVCs) resulting in a sudden deceleration. Concurrent injuries in the thorax and abdomen can make treatment prioritization difficult and require early recognition and prompt intervention. With the increased utilization of minimally invasive endovascular approaches to traumatic aortic (TA) injuries, patients are often spared the increased surgical morbidity (spinal cord ischemia and renal insults) that can be seen with an open technique. The aim of this study was to evaluate a single American College of Surgeons level 1 pediatric trauma center's 22-y experience with TA injuries in children. METHODS: After the Institutional Review Board approval, a 22-y (January 1990-April 2013) retrospective review of all pediatric trauma patients admitted with TA injuries was performed. Patient demographics including age, injury detail, treatment, and outcomes were recorded for analysis. RESULTS: 17 children (<21-y old) were identified with ages ranging from 13-20 y old. The most common mechanism of injury was MVC with all 17 children sustaining TA injuries. The traumatic injuries included aortic transection (9), intimal flap (5), pseudoaneurysm (2), and contained thoracic rupture (1). All children were managed operatively with those before 2008 using an open technique. The endovascular approach was used in 7/17 (41%) cases with the median length of hospitalization 12 d versus 22.5 d using the open approach (P < 0.05). No child required conversion from an endovascular to an open technique for treatment of the aortic injury. There were no operative deaths, no procedure-related paraplegia and all children were discharged home from the hospital. Two children had mild mental deficits as a result of head trauma. CONCLUSIONS: TA injuries are an uncommon injury in children and can result from MVCs or other sudden deceleration mechanisms. Surgical intervention is required in most of the cases and can be performed safely and effectively with low morbidity using an endovascular approach, which is the evolving approach of choice for thoracic aortic injuries. Lengthy follow-up care is recommended in children treated with an endovascular device to monitor for endoleaks and device complications.

Complications of spinal fluid drainage in thoracoabdominal aortic aneurysm repair: a report of 486 patients treated from 1987 to 2008.

OBJECTIVE: Spinal fluid drainage reduces paraplegia risk in thoracic (TAA) and thoracoabdominal (TAAA) aortic aneurysm repair. There has not been a comprehensive study of the risks of spinal fluid drainage and how these risks can be reduced. Here we report complications of spinal fluid drainage in patients undergoing TAA/TAAA repair. METHODS: The study comprised 648 patients who had TAA or TAAA repair from 1987 to 2008. Spinal drains were used in 486 patients. Spinal fluid pressure was measured continuously, except when draining fluid, and was reduced to <6 mm Hg during thoracic aortic occlusion and reperfusion. After surgery, spinal fluid pressure was kept <10 mm Hg until patients were awake with normal leg lift. Drains were removed 48 hours after surgery. Spinal and head computed tomography (CT) scans were performed in patients with bloody spinal fluid or neurologic deficit. We studied the incidence of headache treated with epidural blood patch, infection, bloody spinal fluid, intracranial and spinal bleeding on CT, as well as the clinical consequences. RESULTS: Twenty-four patients (5%) had bloody spinal fluid. CT exams showed seven had no evidence of intracranial hemorrhage, 14 (2.9%) had intracranial blood without neurologic deficit, and three with intracranial bleeding and cerebral atrophy had neurologic deficits (1 died, 1 had permanent hemiparesis, and 1 with transient ataxia recovered fully). Two patients without bloody spinal fluid or neurologic deficit after surgery presented with neurologic deficits 5 days postoperatively and died from acute on chronic subdural hematoma. Neurologic deficits occurred after spinal fluid drainage in 5 of 482 patients (1%), and 3 died. The mortality from spinal fluid drainage complications was 0.6% (3 of 482). By univariate and multivariate analysis, larger volume of spinal fluid drainage (mean, 178 mL vs 124 mL, P < .0001) and higher central venous pressure before thoracic aortic occlusion (mean, 16 mm Hg vs 13 mm Hg, P < .0012) correlated with bloody spinal fluid. CONCLUSION: Strategies that reduce the volume of spinal fluid drainage but still control spinal fluid pressure are helpful in reducing serious complications. Patients with cerebral atrophy are at increased risk for complications of spinal fluid drainage.

A new intercostal artery management strategy for thoracoabdominal aortic aneurysm repair.

OBJECTIVE: The purpose of this study is to describe a new approach for addressing the intraoperative management of intercostal arteries during thoracoabdominal aortic aneurysm (TAAA) repair, using preoperative spinal MRA for detection of intercostal arteries supplying the anterior spinal artery. METHODS: Patients undergoing TAAA repair from August 2005 to September 2007 were included. Spinal artery MRA was performed to identify the anterior spinal artery, the artery of Adamkiewicz, and its major intercostal source artery (SA-AAK). Intraoperative spinal cord protection was carried out using standard techniques. Important intercostal arteries were either preserved or reimplanted as a button patch after removing aortic clamps. Demographic and perioperative data were collected for review. Analysis was performed with Fisher's exact test or Student's t-test, where applicable, using SAS ver. 8.0 (Cary, NC). RESULTS: Spinal artery MRA was performed in 27 patients. The SA-AAK was identified in 85% of preoperative studies. Open or endovascular repair was performed in 74% and 26% of patients, respectively. The SA-AAK was preserved or reimplanted in 13 (65%) of patients who underwent open repair. A mean of 1.67 (range 1-3) intercostal arteries were reimplanted. All patients undergoing endovascular repair necessitated coverage of the SA-AAK. No patient developed immediate or delayed paraplegia. Longer mean operative times in the reimplanted cohort were not statistically significant (330 versus 245 min, P = 0.1). CONCLUSION: The SA-AAK identified by MRA can be preserved or safely reimplanted after TAAA repair. Further study is warranted to determine if selective intercostal reimplantation can reduce the risk of immediate or delayed paraplegia.

A quantitative assessment of the impact of intercostal artery reimplantation on paralysis risk in thoracoabdominal aortic aneurysm repair.

OBJECTIVES: We previously demonstrated an 80% reduction in paraplegia risk using hypothermia, naloxone, steroids, spinal fluid drainage, intercostal ligation, and optimizing hemodynamic parameters. This report demonstrates that intercostal revascularization for the last 3 years further reduced our paraplegia risk index by 75%. METHODS: We evaluated 655 patients who had thoracic or thoracoabdominal aneurysm repair for factors that affected paraplegia risk including aneurysm extent, acuity, cardiac function, blood pressure mean arterial pressure, and spinal fluid drainage with naloxone (SFDN). Eighteen patients died during or shortly after surgery leaving 637 patients for analysis of paralysis. We evaluated the effect of intercostal reimplantation (IRP) using a highly accurate (r(2) > 0.88) paraplegia risk index we developed and published previously. RESULTS: Fifty-eight percent of patients were male with a mean age of 67. Thirty-three percent were acute with rupture, acute dissection, mycotic aortitis, and trauma. Eighty (12%) had dissections. Thirty-five patients had paraplegia or paraparesis (5.4%). Significant factors by univariate analysis (P < 0.05) were Crawford type 2, acuity, SFDN, cardiac index after unclamping, mean arterial pressure during crossclamping, and IRP. In multivariate modeling, aneurysm extent, SFDN, acuity, and IRP remained significant (P < 0.02). The paraplegia risk index declined from 0.20 to 0.05 (P < 0.03). CONCLUSIONS: The incidence of paralysis after TAAA repair decreased from 4.83% to 0.88% and paralysis risk index decreased from 0.26 to 0.05 when intercostal artery reimplantation was added to neuroprotective strategies that had already substantially reduced paralysis risk. These findings suggest that factors that affect collateral blood flow and metabolism account for approximately 80% of paraplegia risk and intercostal blood flow accounts for 20% of risk. This suggests a limit to paraplegia risk reduction in thoracoabdominal endograft patients. Early results in this emerging field support this prediction of high paraplegia risk with thoracoabdominal branched endografts with extensive aortic coverage.