A new predictive model for adverse outcomes after elective thoracoabdominal aortic aneurysm repair

Comparison of open thoracoabdominal repair for chronic aortic dissections and aneurysms

OBJECTIVE

Aortic dissection is common in patients undergoing open surgical repair of thoracoabdominal aortic aneurysms (TAAAs). Most often, dissection is chronic and is associated with progressive aortic dilatation. Because contemporary outcomes in chronic dissection are not clearly understood, we compared patient characteristics and outcomes after open TAAA repair between patients with chronic dissection and those with non-dissection aneurysm.

METHODS

We retrospectively analyzed data from 3470 open TAAA repairs performed in a single practice. Operations were for non-dissection aneurysm in 2351 (67.8%) and chronic dissection in 1119 (32.2%). Outcomes included operative mortality and adverse events, a composite variable comprising operative death and persistent (present at discharge) stroke, paraplegia, paraparesis, and renal failure necessitating dialysis. Logistic regression identified predictors of operative mortality and adverse events. Time-to-event analyses examined survival, death, repair failure, subsequent progressive repair, and survival free of failure or subsequent repair.

RESULTS

Compared with patients with non-dissection aneurysm, those with chronic dissection were younger, had fewer atherosclerotic risk factors, and were more likely to have heritable thoracic aortic disease and undergo extent II repair. The operative mortality rate was 8.5% (n = 296) overall and was higher in non-dissection aneurysm patients (n = 217; 9.2%) than in chronic dissection patients (n = 79; 7.1%; P = .03). Adverse events were less frequent (P = .01) in patients with chronic dissection (n = 145; 13.0%), 22 (2.0%) of whom had persistent paraplegia. Chronic dissection was not predictive of operative mortality (P = .5) or adverse events (P = .6). Operative mortality and adverse events, respectively, were independently predicted by emergency repair (odds ratio [OR], 3.46 and 2.87), chronic kidney disease (OR, 1.74 and 1.81), extent II TAAA repair (OR, 1.44 and 1.73), increasing age (OR, 1.04/year and 1.04/year), and increasing aortic cross-clamp time (OR, 1.02/minutes and 1.02/minutes). Patients with chronic dissection had lower 10-year unadjusted mortality (42% vs 69%) but more frequent repair failure (5% vs 3%) and subsequent repair for progressive aortic disease (11% vs 5%) than patients with non-dissection aneurysm (P < .001); these differences were no longer statistically significant after adjustment.

CONCLUSIONS

Outcomes of open TAAA repair vary by aortic disease type. Emergency repairs and atherosclerotic diseases most commonly occur in patients with non-dissection aneurysm and independently predict operative mortality. Repair of chronic dissection is associated with low rates of adverse events, including operative mortality and persistent paraplegia, along with reasonable late survival and good durability. However, patients with chronic dissection tend to more commonly undergo subsequent repair to treat progressive aortic disease, which emphasizes the need for robust long-term imaging surveillance protocols.

Independent associations with early mortality after open repair of Crawford extent IV thoracoabdominal aortic aneurysms

OBJECTIVE

We aimed to identify outcomes and factors that independently associate with early mortality after open repair of Crawford extent IV thoracoabdominal aortic aneurysms, defined as aneurysms confined to the segment below the diaphragm.

METHODS

This retrospective analysis included 721 extent IV thoracoabdominal aortic aneurysm repairs performed in our institution from 1986 to 2021. Indications for repair were aneurysm without dissection in 627 cases (87.0%) and aortic dissection in 94 cases (13.0%). Overall, 466 patients (64.6%) were symptomatic preoperatively; 124 (17.2%) procedures were performed in patients with acute presentation, including 58 (8.0%) ruptured aneurysms.

RESULTS

Operative death occurred after 49 (6.8%) repairs. Persistent renal failure necessitating dialysis occurred after 43 (6.0%) repairs. Binary logistic regression modeling revealed that previous extent II thoracoabdominal aortic aneurysm repair, chronic kidney disease, previous myocardial infarction, urgent or emergency repair, and longer crossclamp times during surgery were independently associated with operative mortality. Among early survivors (n = 672), competing risk analysis revealed that cumulative incidence of mortality and reintervention rates at 10 years were 74.8% (95% confidence interval, 71.4%-78.5%) and 3.3% (95% confidence interval, 2.2%-5.1%), respectively.

CONCLUSIONS

Although patient comorbidities contributed to operative mortality, factors associated with the repair, such as urgent or emergency status, the duration of aortic crossclamping, and certain types of complex reoperation, also played prominent roles. Patients who survive the operation can expect a durable repair that usually is free from late reintervention. Expanding our collective knowledge regarding patients who undergo open repair of extent IV thoracoabdominal aortic aneurysms will enable clinicians to establish best practices and improve patient outcomes.

Readmissions Following Endovascular Thoracic and Thoracoabdominal Aortic Repairs in The Vascular Implant Surveillance and Interventional Outcomes Network (VISION)

OBJECTIVES

Investigate readmission rates, diagnoses associated with readmission, and associations with mortality through 90-days post-operatively after elective endovascular thoracic and thoracoabdominal aortic repair overall and by extent of coverage.

METHODS

A cohort of index elective non-traumatic endovascular thoracic and thoracoabdominal aortic cases from 2010-2018 was derived from the Vascular Implant Surveillance and Interventional Outcomes Network. Cohort readmissions within 90-days postoperative were examined both overall and by Crawford extent (CE) of aortic coverage. Postoperative mortality was examined by reason for readmission and CE.

RESULTS

The cohort consisted of 2,093 patients who underwent endovascular thoracic and thoracoabdominal aortic repair (1,541 CE 0A/0B; 240 CE 1-3; 312 CE 4-5). Cumulative risk for 90-day readmission was 34.3% in CE 0A/0B repairs, 33.4% in CE4-5 repairs and 47.4% in CE 1-3 repairs. Compared to CE 0A/B, patients with CE 1-3 repairs experienced an increased risk of readmission within 90 days postoperatively after adjusting for preoperative factors (aHR 1.27(1.00,1.61) while the readmission risk for CE 4-5 repairs did not differ significantly (aHR 0.83 (0.64,1.06). Significant risk factors for 90-day readmission included COPD, dialysis dependence, limited ambulation, visceral/spinal ischemia, and in-hospital stroke. Discharge to home was protective against readmission (HR 0.65, CI 0.54-0.79). Patients with a readmission within 90-days had a 7.89-fold increase in 90-day mortality (HR 7.84; 5.17, 11.9) compared to those not readmitted.

CONCLUSIONS

Increasing extent of endovascular thoracic and thoracoabdominal aortic repair was associated with higher 90-day readmission rates. Readmission for all CE was associated with near 8-fold increased risk of mortality. Risk factors associated with increased risk for readmission included pulmonary insufficiency, renal disease, and poor functional status. These findings can inform stakeholders about investment of resources to improve processes of care that both target prevention and mitigate risk of readmission after elective endovascular thoracic and thoracoabdominal aortic repair.

Early and late outcomes of surgical repair of mycotic aortic aneurysms: A 30-year experience

OBJECTIVE

Mycotic aortic aneurysm and its associated complications are often catastrophic. In this study, we examined the early and late outcomes of surgical repair of mycotic aortic aneurysm at our center over the last 3 decades.

METHODS

We retrospectively reviewed our prospectively maintained aortic surgery database with supplemental adjudication of medical records. Aortic infection was confirmed through clinical, radiological, intraoperative, pathological, and treatment evidence.

RESULTS

Seventy-five patients (median age, 68 years; interquartile range, 62-74) who underwent surgical repair of a mycotic aortic aneurysm between 1992 and 2021 were included. Almost all patients (n = 72; 96%) presented with symptoms, including 26 patients (35%) with rupture, and many underwent urgent or emergency repair (n = 64; 85%). Sixty-one patients underwent open repair, and 14 patients underwent hybrid or endovascular repair. Infection-specific adjunct techniques included rifampin-soaked grafts (n = 16), omental pedicle flaps (n = 21), and antibiotic irrigation catheters (n = 8). There were 15 early deaths (20%), including 10 of the 26 patients (38%) who presented with rupture; however, persistent stroke, paraplegia or paraparesis, and renal failure necessitating dialysis were uncommon (each <5%). Almost all early survivors (52/60; 87%) were discharged with long-term antibiotic therapy. Estimated survival at 2, 6, and 10 years was 55.7% ± 5.8%, 39.0% ± 5.7%, and 26.9% ± 5.5%, respectively.

CONCLUSIONS

A substantial proportion of patients with mycotic aortic aneurysm present with rupture and generally require urgent or emergency repair. Operative mortality and complications are common, especially for patients who present with rupture, and late survival is poor.

Outcomes After Extent I Thoracoabdominal Aortic Repair: Focus on Heritable Aortic Disease

BACKGROUND

Crawford extent I thoracoabdominal aortic aneurysm (TAAA) repairs are increasingly performed by an endovascular approach, including in patients with heritable thoracic aortic disease (HTAD). We evaluated outcomes after open extent I TAAA repair in patients with and without HTAD.

METHODS

This retrospective study included 992 patients (median age, 67 years; quartile 1-quartile 3, 57-73 years) who underwent extent I TAAA (1990-2022), stratified by the presence of HTAD (n = 177 [17.8%]). Patients with HTAD had genetic aortopathies or presented at age ≤50 years, and 35% (62 of 177) had Marfan syndrome. Logistic regression was used to identify predictors of operative death and adverse event, a composite of operative death and persistent (present at discharge) stroke, paraplegia, paraparesis, and renal failure necessitating dialysis. Long-term outcomes were analyzed with competing risks analysis.

RESULTS

Patients with HTAD had lower rates of operative mortality (1.7% vs 7.0%, P = .01) and composite adverse event (2.8% vs 12.3%, P < .001) than non-HTAD patients. Most HTAD patients were discharged home (92.6% vs 76.9%, P < .001). Predictors of operative death were increasing age, aortic dissection, tobacco use, chronic symptoms, and rupture. Predictors for adverse event were increasing age, acute symptoms, chronic dissection, and rupture. Patients with HTAD had substantially better repair-failure-free survival (P < .001).

CONCLUSIONS

Open extent I TAAA repair was effective in patients with HTAD, with low operative mortality and adverse event rates, better late survival, and excellent long-term durability, making a compelling argument for preferring open repair in these patients.

Staged Repair of Extensive Aneurysms of the Thoracic Aorta by Using the Elephant Trunk Technique

BACKGROUND

Staged open repair of extensive aortic aneurysm by using the elephant trunk (ET) technique has facilitated the treatment of aortic aneurysms that affect the entire thoracic aorta. We describe our nearly 3-decade experience with classic ET repairs.

METHODS

From 1990 through 2021, we performed 363 stage-1 ET repairs to replace the transverse aortic arch in patients with a median age of 65 years [interquartile range: 56-71]. Fifty-six patients (15.4%) presented with acute symptoms, and 182 (50.1%) underwent redo sternotomy. After a median interval of 3.2 months [IQR: 2.0-7.3], 203 (55.9%) patients underwent stage-2 ET completion; few (n=16; 7.9%) had acute symptoms. Stage-2 repairs comprised 162 (80.6%) extent I or II thoracoabdominal aortic replacements. We examined postoperative outcomes including operative mortality, adverse event (a composite end point), survival, and repair failure.

RESULTS

Operative mortality was 12.4% (45/363) after stage-1 and 10.3% (21/203) after stage-2. The rates of adverse event were 18.5% (67/363) for stage-1 and 18.4% (38/203) for stage-2. Acute symptoms independently predicted operative mortality and adverse event for both stage-1 and stage-2 repairs; additional predictors for stage-2 repairs were older age and extent II repair. Survival was significantly worse for patients who did not receive their stage-2 completion repair than for those who did (p <0.001).

CONCLUSIONS

Treating extensive aortic aneurysms by using the ET technique for staged repair is associated with substantial morbidity and mortality. Patients who present with acute symptoms are at greater risk of operative mortality and adverse event. Diligent surveillance is needed between stages.

A 23-year experience with the reversed elephant trunk technique for staged repair of extensive thoracic aortic aneurysm

OBJECTIVE

The reversed elephant trunk technique permits staged repair of extensive thoracic aortic aneurysm in patients whose distal (ie, descending thoracic and thoracoabdominal) aorta is symptomatic or disproportionately large compared with their proximal aorta (ie, ascending aorta and transverse aortic arch). We present our 23-year experience with the reversed elephant trunk approach.

METHODS

Between 1994 and 2017, 94 patients (median age 62 [46-69] years) underwent stage 1 reversed elephant trunk repair of the distal aorta. Fifty-three patients (56%) had aortic dissection, and 31 patients (33%) had heritable thoracic aortic disease. Eighty-eight operations (94%) were Crawford extent I or II thoracoabdominal aortic repairs. Twenty-seven patients (29%) underwent subsequent stage 2 repair of the proximal aorta; 14 patients (52%) required redo median sternotomy. The median time between the stage 1 and 2 operations was 18.8 (4.8-69.3) months.

RESULTS

The operative mortality was 10% (9/94) for stage 1 repairs and 4% (1/27) for stage 2 repairs; 1 patient with heritable thoracic aortic disease died after stage 1 repair (1/31, 3%), and 1 patient died after stage 2 repair (1/13, 8%). Two patients (2%) had ruptures after stage 1 repair; 1 resulted in death, and 1 precipitated emergency stage 2 repair. In total, 36 patients (38%) who survived stage 1 repair died before stage 2 reversed elephant trunk completion repair could be performed.

CONCLUSIONS

Managing extensive aortic aneurysm with the 2-stage reversed elephant trunk technique yields acceptable short-term outcomes. This technique is useful for the reversed elephant trunk in patients who require distal aortic repair before proximal repair and is particularly effective in patients with heritable thoracic aortic disease. The low number of patients returning for completion repair is concerning. Rigorous surveillance is needed.

Early Gastrointestinal Complications After Open Thoracoabdominal Aortic Aneurysm Repair

BACKGROUND

The present study was done to examine the incidence, predictors, and impact of early gastrointestinal (GI) complications after open thoracoabdominal aortic aneurysm repair.

METHODS

We retrospectively analyzed data from 3587 open thoracoabdominal aortic aneurysm repairs performed at our center from 1986 to 2019. We used univariate analyses and multivariable logistic regression to identify risk factors associated with GI complications, including bleeding, ischemia, obstruction, and acute pancreatitis. Adverse event was defined as operative death or persistent stroke, paraplegia, paraparesis, or renal failure necessitating dialysis.

RESULTS

Gastrointestinal complications developed after 213 repairs (5.9%). Gastrointestinal complications less often developed after extent I repair than after repairs that involved infrarenal abdominal aortic segments (ie, extent II to IV repairs; P = .003). Patients who had GI complications more often underwent endarterectomy, stenting, or bypass of visceral arteries (51.2% vs 42.2%; P = .01). Use of selective visceral perfusion did not differ between groups. Patients who had GI complications had higher rates of operative mortality (34.3% vs 6.6%) and adverse events (44.1% vs 13.2%) and had longer hospitalization (29 vs 11 days; P < .001 for all). Independent predictors of GI complications included incidental splenectomy, rupture, non-extent I repair, older age, and longer aortic cross-clamp time. Short-term, midterm, and long-term survival were poorer for patients who had GI complications (P < .001).

CONCLUSIONS

Although uncommon, early GI complications after open thoracoabdominal aortic aneurysm repair are associated with significant early and late morbidity and mortality. Development of perioperative strategies to mitigate these complications is warranted.

Spinal cord deficit after 1114 extent II open thoracoabdominal aortic aneurysm repairs

OBJECTIVE

Crawford extent II repairs are the most extensive thoracoabdominal aortic aneurysm operations and pose the greatest risk of postoperative spinal cord deficit. We sought to examine spinal cord deficit after open extent II thoracoabdominal aortic aneurysm repair to identify predictors of the most serious type: persistent paraplegia or paraparesis.

METHODS

We included 1114 extent II thoracoabdominal aortic aneurysm repairs performed from 1991 to 2017. Intercostal/lumbar artery reattachment (n = 959, 86.1%) and cerebrospinal fluid drainage (n = 698, 62.7%) were used to mitigate the risk of postoperative spinal cord deficit. We used univariate and multivariable analyses to examine spinal cord deficit and identify predictors of persistent paraplegia or paraparesis, defined as paraplegia or paraparesis present at the time of early death or hospital discharge.

RESULTS

Spinal cord deficit developed after 151 (13.6%) repairs: 86 (7.7%) cases of persistent paraplegia or paraparesis (51 paraplegia; 35 paraparesis) and 65 (6.1%) cases of transient paraplegia or paraparesis. Patients with spinal cord deficit were older (median 68 vs 65 years, P < .001) and had more rupture (6.6% vs 2.2%, P = .002) and urgent/emergency repair (25.2% vs 16.9%, P = .01) than those without. Persistent paraplegia or paraparesis developed immediately in 47 patients (4.2%) and was delayed in 39 patients (3.5%). Urgent/emergency repair (relative risk ratio, 2.31; P = .002), coronary artery disease (relative risk ratio, 1.80, P = .01), and chronic symptoms (relative risk ratio, 1.76, P = .02) independently predicted persistent paraplegia or paraparesis. Reattaching intercostal/lumbar arteries (relative risk ratio, 0.38, P < .001) and heritable disease (relative risk ratio, 0.36, P = .01) were protective. Early and late survival were poorer in those with persistent paraplegia or paraparesis than in those without.

CONCLUSIONS

Spinal cord deficit after extent II thoracoabdominal aortic aneurysm repairs remains concerning; survival is worse in patients with persistent paraplegia or paraparesis. The complexity of spinal cord deficit and persistent paraplegia or paraparesis warrant further study.

Thoracoabdominal Aortic Aneurysm Repair: From an Era of Revolution to an Era of Evolution

Thoracoabdominal aortic aneurysm (TAAA) repair has a rich and storied tradition that began in Houston, Texas with great pioneer surgeons such as Drs Michael E. DeBakey, Denton A. Cooley, and E. Stanley Crawford. Their early attempts to repair TAAA were complicated by the persistent threats of renal and spinal cord ischemia and difficulty in reattaching the branching vessels of the thoracoabdominal aorta. Today, under the tutelage of Dr Joseph S. Coselli, the Texas Medical Center remains at the forefront of TAAA repair. In this place where great surgeons once walked the halls, their legacy continues.

Are outcomes of thoracoabdominal aortic aneurysm repair different in men versus women? A propensity-matched comparison

OBJECTIVE

Women fare worse than men after many cardiovascular operations, including coronary artery bypass grafting and valve surgery. We sought to determine whether sex affects outcomes after open thoracoabdominal aortic aneurysm repair.

METHODS

We evaluated data on 3353 consecutive patients (1281 women, 38.2%) who underwent open thoracoabdominal aortic aneurysm repair between October 1986 and July 2015. We compared preoperative characteristics, surgical variables, and outcomes between men and women in the overall group. A propensity-matching analysis was performed to adjust for preoperative and intraoperative differences. A multivariable analysis was conducted to identify predictors of poor outcomes using relevant preoperative and intraoperative factors.

RESULTS

Men had a significantly higher prevalence of comorbid conditions, including coronary artery disease, and presented more often with dissection; women were slightly older than men (median age, 69 [62-74] years vs 67 [57-73] years; P < .001) and more often symptomatic. Men underwent extent II and IV repairs more often, whereas women more often had extent I and III repairs. The propensity analysis resulted in 958 matched pairs. Overall, women and men had similar early mortality (7.9% vs 7.2%, P = .5) and adverse event rates (14.8% vs 14.1%, P = .6), which were similar in propensity-matched groups. Multivariable analysis showed that predictors of operative death and adverse event differed between the sexes. Survival and freedom from repair failure were similar between the overall and matched groups.

CONCLUSIONS

Men and women who undergo thoracoabdominal aortic aneurysm repair have similar outcomes, but there are important differences in several perioperative factors and predictors of poor outcomes.

Thoracoabdominal Aortic Aneurysm Repair: Reducing Adverse Outcome with Left Heart Bypass, Selective Visceral Perfusion and Renal Protection

Objective: To report our experience with left heart bypass and selective visceral perfusion for prevention of permanent spinal cord injury and distal organ failure in patients undergoing thoracoabdominal aortic aneurysm repair.

Methods: From April 2001 to March 2002 seven patients were electively operated on with left heart bypass and selective perfusion of the visceral and renal organs at the University Clinic of Vienna, Austria. There were four males (57%) and two females (43%) with a mean age of 70 ± 6 years. Etiology of the aneurysm was a chronic dissection in one patient and athereosclerotic in the remaining five. Crawford classification was I in one patient (14%), II in five patients (86%) and III in one patient (14%). Existing comorbidities were hypertension in all seven patients, coronary artery disease in two patients (29%), chronic pulmonary obstructive disease in two patients (29%), and lung cancer resection and peripheral artery occlusive disease in one patient (14%) each. Two patients had a history of prior aortic aneurysm repair, namely elective repair of the ascending thoracic aorta 2 months before the thoracoabdominal aortic aneurysm repair, and replacement of the infrarenal aorta 12 years previously in another patient.

Results: All patients survived the operation and were discharged after a mean hospital stay of 25 ± 13 days. Adverse outcome occurred in three out of seven patients. One patient with Crawford classification 11 developed acute renal insufficiency, and two patients with class 11 and III showed signs of transient paraparesis, respectively. Mean intraoperative blood loss was 3315 ± 701 ml. On average, 6.7 ± 2.8 units of packed red cells, 10 units of fresh frozen plasma, and 1 unit of platelets were given during the operation. Intensive care unit stay ranged from 2 to 16 days.

Conclusions: The combined usage of left heart bypass, selective visceral perfusion, and renal protection can be recommended as a useful and effective technique in order to minimize adverse outcome in patients undergoing repair of the thoracoabdominal aorta.

Organ Protection During Thoracoabdominal Aortic Surgery: Rationale for a Multimodality Approach

Surgical repair of thoracoabdominal aortic aneurysms (TAAAs) remains a technically challenging operation that requires a systematic approach to prevent ischemic complications and achieve excellent clinical outcomes. Techniques for organ protection have evolved substantially over the past 20 years. This review describes our current multimodality approach to organ protection during TAAA repair.

Bypass Techniques for Descending Thoracic Aortic Surgery

The conduct of partial left heart bypass or partial car diopulmonary bypass (CPB) during surgery involving the descending thoracic aorta or thoracoabdominal aorta is one of the most unappreciated and misunder stood extracorporeal circulation procedures in cardio vascular surgery. It is different from conventional CPB, and although some uninitiated practitioners consider it simpler, it is in fact more complicated than conven tional CPB and involves different concepts. It requires expertise and skill in regulating the flow, pressure, and oxygenation of blood going to both the proximal and distal parts of the body and management of the special bypass or shunt procedures used, specialized monitor ing, and knowledge about the protection and preserva tion of organs both proximal and distal to the aortic clamping. It demands exquisite communication and un derstanding of the unique problems faced by the sur geon, anesthesiologist, and perfusionist.

Ortner's syndrome presenting as thoracic aortic aneurysm mimicking thoracic malignancy: a case report

Introduction

Ortner’s syndrome is defined as left recurrent laryngeal nerve palsy caused by a cardiovascular pathology. Here we report the case of a 68-year-old man who presented to our hospital with hoarseness, whose initial chest imaging mimicked a thoracic neoplastic process with left pleural effusion. The final diagnosis was Ortner’s syndrome due to the silent rupture of a thoracoabdominal aortic aneurysm. Diagnostic thoracentesis, before computed tomography, in resource-poor settings, may have resulted in an adverse outcome in our case.

Case presentation

A 68-year-old Sri Lankan man was referred to us by an otolaryngologist for further evaluation of a suspected thoracic malignancy. His presenting symptom was hoarseness of three months duration. He had essential hypertension for the last four years and had a history of 25 pack-years of cigarettes smoking. His chest X-ray showed a left-sided mediastinal mass with mild to moderate pleural effusion. An ultrasound appeared to show an encysted pleural fluid collection. However, we proceeded with computed tomography before diagnostic thoracentesis. The diagnosis of Ortner’s syndrome was made after the computed tomography due to the silent rupture of his thoracoabdominal aortic aneurysm.

Conclusions

Hoarseness due to left recurrent laryngeal nerve palsy can be the presenting symptom of cardiovascular pathologies, Ortner’s syndrome. Silent rupture of thoracic aortic aneurysms can mimic that of thoracic malignancy, which is reported in literature. We illustrate the importance of a high degree of suspicion of cardiovascular pathology in order to avoid an adverse outcome following diagnostic thoracentesis.

External validation of new risk prediction models is infrequent and reveals worse prognostic discrimination

OBJECTIVES

To evaluate how often newly developed risk prediction models undergo external validation and how well they perform in such validations.

STUDY DESIGN AND SETTING

We reviewed derivation studies of newly proposed risk models and their subsequent external validations. Study characteristics, outcome(s), and models' discriminatory performance [area under the curve, (AUC)] in derivation and validation studies were extracted. We estimated the probability of having a validation, change in discriminatory performance with more stringent external validation by overlapping or different authors compared to the derivation estimates.

RESULTS

We evaluated 127 new prediction models. Of those, for 32 models (25%), at least an external validation study was identified; in 22 models (17%), the validation had been done by entirely different authors. The probability of having an external validation by different authors within 5 years was 16%. AUC estimates significantly decreased during external validation vs. the derivation study [median AUC change: -0.05 (P < 0.001) overall; -0.04 (P = 0.009) for validation by overlapping authors; -0.05 (P < 0.001) for validation by different authors]. On external validation, AUC decreased by at least 0.03 in 19 models and never increased by at least 0.03 (P < 0.001).

CONCLUSION

External independent validation of predictive models in different studies is uncommon. Predictive performance may worsen substantially on external validation.

Preoperative prediction of spinal cord ischemia after thoracic endovascular aortic repair

OBJECTIVE

Spinal cord ischemia (SCI) is a devastating but potentially preventable complication of thoracic endovascular aortic repair (TEVAR). The purpose of this analysis was to determine what factors predict SCI after TEVAR.

METHODS

All TEVAR procedures at a single institution were reviewed for patient characteristics, prior aortic repair history, aortic centerline of flow analysis, and procedural characteristics. SCI was defined as any lower extremity neurologic deficit that was not attributable to an intracranial process or peripheral neuropathy. Forty-three patient and procedural variables were evaluated individually for association with SCI. Those with the strongest relationships to SCI (P < .1) were included in a multivariable logistic regression model, and a stepwise variable elimination algorithm was bootstrapped to derive a best subset of predictors from this model.

RESULTS

From 2002 to 2013, 741 patients underwent TEVAR for various indications, and 68 (9.2%) developed SCI (permanent: n = 38; 5.1%). Because of the lack of adequate imaging for centerline analysis, 586 patients (any SCI, n = 43; 7.4%) were subsequently analyzed. Patients experiencing SCI after TEVAR were older (SCI, 72 ± 11 years; no SCI, 65 ± 15 years; P < .0001) and had significantly higher rates of multiple cardiovascular risk factors. The stepwise selection procedure identified five variables as the most important predictors of SCI: age (odds ratio [OR] multiplies by 1.3 per 10 years; 95% confidence interval [CI], 0.9-1.8, P = .06), aortic coverage length (OR multiplies by 1.3 per 5 cm; CI, 1.1-1.6; P = .002), chronic obstructive pulmonary disease (OR, 1.9; CI, 0.9-4.1; P = .1), chronic renal insufficiency (creatinine concentration ≥ 1.6 mg/dL; OR, 1.9; CI, 0.8-4.2; P = .1), and hypertension (defined as chart history or medication; OR, 6.4; CI, 2.6-18; P < .0001). A logistic regression model with just these five covariates had excellent discrimination (area under the receiver operating characteristic curve = .83) and calibration (χ(2) = 9.8; P = .28).

CONCLUSIONS

This analysis generated a simple model that reliably predicts SCI after TEVAR. This clinical tool can assist decision-making about when to proceed with TEVAR, guide discussions about intervention risk, and help determine when maneuvers to mitigate SCI risk should be implemented.

Evaluation of the optimal visceral branch configuration in open thoracoabdominal aortic repair by computed tomography

BACKGROUND

In thoracoabdominal aneurysm (TAAA) repair, our technical modification of visceral reconstruction using longer cut pre-sewn side branches has provided good surgical outcomes. Here, we assessed the long-term durability and patency of revascularized branches using computed tomography (CT) to confirm the validity of our approach.

METHODS

Early and late CT evaluations were performed in 11 TAAA patients (males: 5; mean age: 60.6 years) using the Coselli graft to evaluate the position of main graft and the diverging pattern and patency of side branches. Seven of 11 were sutured in an extra-anatomical fashion using longer cut side branches.

RESULTS

In Anatomical (n = 4) and Extra-anatomical (n = 7) groups, the early patency of side branches was not significantly different. Although the late patency of right renal artery (RA) was 100% in both groups, the one of left RA was 60% in Extra-anatomical, while 100% in Anatomical. Furthermore, the main graft in Extra-anatomical was significantly posterior and leftward to the spine with left RA side branch diverging at an acute angle.

CONCLUSIONS

When a pre-sewn branched graft designed for TAAA is used, the graft should be sutured in a fashion similar to normal patient anatomy to minimize the possibility of kinking of RA side branch for the patency.

Results of open thoracoabdominal aortic aneurysm repair

BACKGROUND

Open surgical repair of thoracoabdominal aortic aneurysms (TAAAs) enables the effective replacement of the diseased aortic segment and reliably prevents aneurysm rupture. However, these operations also carry substantial risk of perioperative morbidity and mortality, principally caused by the associated ischemic insult involving the spinal cord, kidneys, and other abdominal viscera. Here, we describe the early outcomes of a contemporary series of open TAAA repairs.

METHODS

We reviewed the outcomes of 823 open TAAA repairs performed between January 2005 and May 2012. Of these, 209 (25.4%) were Crawford extent I repairs, 264 (32.1%) were extent II, 157 (19.1%) were extent III, and 193 (23.5%) were extent IV. Aortic dissection was present in 350 (42.5%) cases, and aneurysm rupture was present in 37 (4.5%). Adjuncts used during the procedures included cerebrospinal fluid drainage in 639 (77.6%) cases, left heart bypass in 430 (52.2%), and cold renal perfusion in 674 (81.9%).

RESULTS

The composite endpoint, adverse outcome-defined as operative death, renal failure that necessitated dialysis at discharge, stroke, or permanent paraplegia or paraparesis-occurred after 131 (15.9%) procedures. There were 69 (8.4%) operative deaths. Permanent paraplegia or paraparesis occurred after 42 (5.1%) cases, stroke occurred after 27 (3.3%), and renal failure necessitating permanent dialysis occurred after 45 (5.5%).

CONCLUSIONS

Although open surgical repair of the thoracoabdominal aorta can be life-saving to patients at risk for fatal aneurysm rupture, these operations remain challenging and are associated with substantial risk of early death and major complications. Additional improvements are needed to further reduce the risks associated with TAAA repair, particularly as increasing numbers of patients with advanced age and multiple or severe comorbidities present for treatment.

Acute kidney injury after cardiovascular surgery: an overview

Acute kidney injury is a complication of open-heart surgery that carries a poor prognosis. Studies have shown that postoperative renal function deterioration in cardiovascular surgery patients increases in-hospital mortality and adversely affects long-term survival. Identifying individuals at risk for developing AKI and aggressive early intervention is extremely important to optimize outcomes. This paper provides an overview of the etiology, prognostic markers, risk factors, and prevention of AKI and treatments that may favorably affect outcomes.

Staged hybrid approach using proximal thoracic endovascular aneurysm repair and distal open repair for the treatment of extensive thoracoabdominal aortic aneurysms

OBJECTIVE

Repair of patients with extent I and II thoracoabdominal aortic aneurysms (TAAAs) is associated with significant morbidity and mortality, whereas repair of more distal extent III and IV TAAAs has a lower risk of paraplegia and death. Therefore, we describe an approach using thoracic endovascular aneurysm repair (TEVAR) as the index operation to convert extent I and II TAAAs to extent III and IV TAAAs amenable to subsequent open aortic repair to minimize patient risk.

METHODS

Between July 2007 and March 2012, 10 staged hybrid operations were performed to treat one extent I and nine extent II TAAAs. Aortic aneurysm pathology included five chronic type B dissections, three acute type B dissections, and two penetrating aortic ulcers. Initially, the proximal descending thoracic aorta was repaired with TEVAR for coverage of the most proximal fenestration or penetrating ulcer, with seven elective and three emergent repairs. Interval open distal aortic replacement was performed in a short-term planned setting or for progressive dilation of the distal aortic segment. In the open repair, the proximal end of the graft was sewn directly to the distal end of the TEVAR and outer wall of the aorta.

RESULTS

Average patient age was 48 years, and 60% were men. Risk factors included hypertension (80%), current tobacco use (50%), and Marfan syndrome (30%). Complications after TEVAR included type IA (n=1) and type II (n=3) endoleaks, pleural effusions (n=3), and acute kidney injury (n=1). Three patients required endovascular reinterventions. In patients with dissection, persistent filling of the false lumen was common and associated with distal thoracic aortic dilation. Complications of open repair included acute kidney injury in two patients, but no cardiac, pulmonary, or neurologic morbidity. Median time between TEVAR and open repair was 14 weeks. Most importantly, no deaths or neurologic deficits occurred after either procedure during a median follow-up of 35 weeks.

CONCLUSIONS

A staged hybrid approach to extensive TAAAs combining proximal TEVAR, followed by interval open distal TAAA repair, is safe and appears to be an effective alternative to traditional open repair. This approach may decrease the significant morbidity associated with single-stage open extent I and II TAAA repairs and may be applicable to multiple TAAA etiologies.

Risk factors, outcomes, and clinical manifestations of spinal cord ischemia following thoracic endovascular aortic repair

OBJECTIVE

The purpose of this study was to assess the incidence, risk factors, and clinical manifestations of spinal cord ischemia (SCI) after thoracic endovascular aortic repair (TEVAR).

METHODS

A retrospective review of a prospectively collected database was performed for all patients undergoing TEVAR at a single academic institution between July 2002 and June 2010. Preoperative demographics, procedure-related variables, and clinical details related to SCI were examined. Logistic regression analysis was performed to identify risk factors for the development of SCI.

RESULTS

Of the 424 patients who underwent TEVAR during the study period, 12 patients (2.8%) developed SCI. Mean age of this cohort with SCI was 69.6 years (range, 44-84 years), and 7 were women. One-half of these patients had prior open or endovascular aortic repair. Indication for surgery was either degenerative aneurysm (n = 8) or dissection (n = 4). Six TEVARs were performed electively, with the remaining done either urgently or emergently due to contained rupture (n = 2), dissection with malperfusion (n = 2), or severe back pain (n = 2). All 12 patients underwent extent C endovascular coverage. Multivariate regression analysis demonstrated chronic renal insufficiency to be independently associated with SCI (odds ratio [OR], 4.39; 95% confidence interval [CI], 1.2-16.6; P = .029). Onset of SCI occurred at a median of 10.6 hours (range, 0-229 hours) postprocedure and was delayed in 83% (n = 10) of patients. Clinical manifestations of SCI included lower extremity paraparesis in 9 patients and paraplegia in 3 patients. At SCI onset, average mean arterial pressure (MAP) and lumbar cerebrospinal fluid (CSF) pressure was 77 mm Hg and 10 mm Hg, respectively. Therapeutic interventions increased blood pressure to a significantly higher average MAP of 99 mm Hg (P = .001) and decreased lumbar CSF pressure to a mean of 7 mm Hg (P = .30) at the time of neurologic recovery. Thirty-day mortality was 8% (1 of 12 patients). The single patient who expired, never recovered any lower extremity neurologic function. All patients surviving to discharge experienced either complete (n = 9) or incomplete (n = 2) neurologic recovery. At mean follow-up of 49 months, 7 of 9 patients currently alive continued to exhibit complete, sustained neurologic recovery.

CONCLUSION

Spinal cord ischemia after TEVAR is an uncommon, but important complication. Preoperative renal insufficiency was identified as a risk factor for the development of SCI. Early detection and treatment of SCI with blood pressure augmentation alone or in combination with CSF drainage was effective in most patients, with the majority achieving complete, long-term neurologic recovery.

Contemporary results for open repair of suprarenal and type IV thoracoabdominal aortic aneurysms

Background

Endovascular and hybrid procedures are not yet widely established in the management of type IV thoracoabdominal aortic aneurysm (TAAA). Open surgery remains the treatment of choice until the long-term outcomes of these novel techniques are known.

Methods

This study reviewed a 10-year experience of open repair of non-ruptured type IV and suprarenal TAAA. All procedures were performed using a totally abdominal approach with supracoeliac clamping of the aorta.

Results

There were 53 patients (31 men; 58 per cent) of median age 69 (range 54–82) years. Forty-four patients had a type IV TAAA and nine a suprarenal aneurysm. Three patients (6 per cent) died within 30 days and the 12-month mortality rate for patients followed for at least 1 year was 6 per cent (three of 49). Ten patients (19 per cent) had a cardiac complication, 20 (38 percent) a respiratory complication, three (6 percent) required early reoperation, and one patient (2 percent) developed permanent paraplegia. There was one late death resulting from an aneurysm-related complication.

Conclusion

Open repair of suprarenal aneurysms and type IV TAAA may be undertaken using a totally abdominal approach with acceptable levels of morbidity and mortality.

Neurologic outcomes from high risk descending thoracic and thoracoabdominal aortic operations in the era of endovascular repair

INTRODUCTION

Spinal cord ischemia and stroke are recognized complications of descending thoracic (DTA) and thoracoabdominal aortic (TAA) operations. However, there are limited data available on outcomes since the advent of thoracic endovascular aortic repair (TEVAR).

METHODS

We reviewed charts from consecutive patients who underwent open DTA and TAA operations, excluding type IV repair, from January, 2000 through April, 2005.

RESULTS

A total of 224 open DTA and TAA operations were included in the analysis. During this period 108 additional patients received TEVAR, accounting for 66% of all DTA repairs. Among the 224 patients who underwent open surgery, 63 patients (28%) developed spinal ischemia postprocedure, 13 (6%) had a stroke, and 9 (4%) had both. The 30 day in-hospital mortality was 18%. Neurologic complications were strongly associated with mortality: 64% of patients with stroke died compared to 17% without (P < 0.001) and 39% of patients with spinal ischemia died compared to 14% without (P < 0.001). At discharge, 29% had a poor outcome from surgery, defined as death or moderate-to-severe neurologic disability. A multivariable logistic regression incorporating characteristics known prior to surgery resulted in a score to stratify risk of poor outcome by giving one point each for age > or =60, history of cerebrovascular disease, Crawford extent II or III repair, and acute rupture. Patients with score > or =3 had an estimated 60% risk for poor outcome, while those with score < or =1 had an estimated risk of 7-11%.

CONCLUSIONS

Ischemic neurologic complications were frequent and strongly associated with poor outcomes after open DTA and TAA repair among patients not eligible for TEVAR. Risk of death or neurologic disability can be estimated based on factors known prior to surgery.

Impact of mild acute kidney injury (AKI) on outcome after open repair of aortic aneurysms

Recently, mild AKI has been considered as a risk factor for mortality in different scenarios. We conducted a retrospective analysis of the risk factors for two distinct definitions of AKI after elective repair of aortic aneurysms. Logistic regression was carried out to identify independent risk factors for AKI (defined as $25% or $50% increase in baseline SCr within 48 h after surgery, AKI 25% and AKI 50%, respectively) and for mortality. Of 77 patients studied (mean age 68 +/- 10, 83% male), 57% developed AKI 25% and 33.7% AKI 50%. There were no differences between AKI and control groups regarding comorbidities and diameter of aneurysms. However, AKI patients needed a supra-renal aortic cross-clamping more frequently and were more severely ill. Overall in-hospital mortality was 27.3%, which was markedly higher in those requiring a supra-renal aortic cross-clamping. The risk factors for AKI 25% were supra-renal aortic cross-clamping (odds ratio 5.51, 95% CI 1.05-36.12, p = 0.04) and duration of operation for AKI 25% (OR 6.67, 95% CI 2.23-19.9, p < 0.001). For AKI 50%, in addition to those factors, post-operative use of vasoactive drugs remained as an independent factor (OR 6.13, 95% CI 1.64-22.8, p = 0.005). The risk factors associated with mortality were need of supra-renal aortic cross-clamping (OR 9.6, 95% CI 1.37-67.88, p = 0.02), development of AKI 50% (OR 8.84, 95% CI 1.31-59.39, p = 0.02), baseline GFR lower than 49 mL/min (OR 17.07, 95% CI 2.00-145.23, p = 0.009), and serum glucose > 118 mg/dL in the post-operative period (OR 19.99, 95% CI 2.32-172.28, p = 0.006). An increase of at least 50% in baseline SCr is a common event after surgical repair of aortic aneurysms, particularly when a supra-renal aortic cross-clamping is needed. Along with baseline moderate chronic renal failure, AKI is an independent factor contributing to the high mortality found in this scenario.