Glomerular filtration rate is superior to serum creatinine for prediction of mortality after thoracoabdominal aortic surgery

Outcomes of open repair for descending thoracic and thoracoabdominal aortic aneurysm in recent 10 years: experience of a high-volume centre in Korea

OBJECTIVES

Although recent studies and guidelines suggest the preferred outcomes after surgical repair of thoracic aortic aneurysm (TAA) and thoracoabdominal aortic aneurysm (TAAA), published results are limited to those from high-volume hospitals and based on old data gathered before optimal management was established. Here, we analysed our outcomes over the previous 10 years from cases of open TAA and TAAA repair to offer updated and real-world results of those complex procedures performed in a high-volume centre.

METHODS

From November 2013 to April 2022, 212 consecutive adult patients who underwent open TAA and TAAA repair were enrolled. We analysed early and late outcomes after surgery, including postoperative complications and mortality.

RESULTS

There were 154 (73%) men, and the median age at surgery was 61 years. Intraoperative death occurred in 1 patient due to uncontrolled bleeding. Nine patients (4%) died during follow-up, and the survival estimates at 5 years were 94 ± 3% and 95 ± 3% after descending TAA and TAAA repair, respectively. Ten patients (4%) suffered from spinal cord ischaemic injury (9 with paraplegia and 1 with paresthesia), but permanent paraplegia persisted in only 1 case.

CONCLUSIONS

We report very low postoperative complication rates and excellent early and late survival rates after open TAA and TAAA repair from our recent 10-year data analysis. These findings may assist when choosing treatment options for these complicated diseases.

Open Treatments for Thoracoabdominal Aortic Aneurysm Repair

Thoracoabdominal aortic aneurysms (TAAA) represent a unique pathology that is associated with considerable mortality if untreated. While the advent of endovascular technologies has introduced new modalities for consideration, the mainstay of TAAA treatment remains open surgical repair. However, the optimal conduct of open TAAA repair requires careful consideration of patient risk factors and a collaborative team effort to mitigate the risk of perioperative complications. In this chapter, we briefly outline the history of treating TAAA, preoperative preparation and postoperative care, and our operative techniques for treatment.

Effectiveness of a new cardiac risk scoring model reclassified by QRS fragmentation as a predictor of postoperative cardiac event in patients with severe renal dysfunction

Background

It is difficult to evaluate the risk of patients with severe renal dysfunction before surgery due to various limitations despite high postoperative cardiac events. This study aimed to investigate the value of a newly reclassified Revised Cardiac Risk Index (RCRI) that incorporates QRS fragmentation (fQRS) as a predictor of postoperative cardiac events in patients with severe renal dysfunction.

Methods

Among the patients with severe renal dysfunction, 256 consecutive patients who underwent both a nuclear stress test and noncardiac surgery were evaluated. We reclassified RCRI as fragmented RCRI (FRCRI) by integrating fQRS on electrocardiography. We defined postoperative major adverse cardiac event (MACE) as a composite of cardiac death, nonfatal myocardial infarction, and pulmonary edema.

Results

Twenty-eight patients (10.9%) developed postoperative MACE, and this was significantly frequent in patients with myocardial perfusion defect (41.4% vs. 28.0%, p = 0.031). fQRS was observed 84 (32.8%) patients, and it was proven to be an independent predictor of postoperative MACE after adjusting for the RCRI (odds ratio 3.279, 95% confidence interval (CI) 1.419–7.580, p = 0.005). Moreover, fQRS had an incremental prognostic value for the RCRI (chi-square = 7.8, p = 0.005), and to the combination of RCRI and age (chi-square = 9.1, p = 0.003). The area under curve for predicting postoperative MACE significantly increased from 0.612 for RCRI to 0.667 for FRCRI (p = 0.027) and 23 patients (32.4%) originally classified as RCRI 2 were reclassified as FRCRI 3.

Conclusions

A newly reclassified FRCRI that incorporates fQRS, is a valuable predictor of postoperative MACE in patients with severe renal dysfunction undergoing noncardiac surgery.

Long-term outcomes of intervention between open repair and endovascular aortic repair for descending aortic pathologies: a propensity-matched analysis

BACKGROUND

The long-term complication rates of open repair and thoracic endovascular aortic repair (TEVAR) have not yet been determined. Therefore, this study aimed to compare the long-term outcomes and aortic reintervention rates between open repair and TEVAR in patients with descending thoracic aortic pathologies.

METHODS

Between January 2002 and December 2017, 230 patients with descending thoracic aortic pathologies underwent surgery. Of these, 136 patients were included in this retrospective study: 45 patients (10, 2, and 33 with dissection, penetrating atherosclerotic ulcer, and pseudoaneurysm, respectively) underwent open repair and 91 patients (27, 1, and 63 with dissection, penetrating atherosclerotic ulcer, and pseudoaneurysm, respectively) underwent TEVAR. The primary end points were in-hospital mortality, and short-term complications. The secondary end points were long-term mortality and reintervention rates. Based on the propensity score matching (PSM), 35 patients who underwent open repair were matched to 35 patients who underwent TEVAR (ratio = 1:1).

RESULTS

The mean follow-up period was 70.2 ± 51.9 months. Shorter intensive care unit and hospital stay were seen in the TEVAR group than in the open repair group before and after PSM (p < 0.001 and p < 0.001, respectively). However, in-hospital mortality, and spinal cord ischemia were not significantly different among the two groups (before PSM: p = 0.068 and p = 0.211, respectively; after PSM: p = 0.303 and p = 0.314, respectively). The cumulative all-cause death and aorta-related death showed no significant differences between the two groups (before PSM: p = 0.709 and p = 0.734, respectively; after PSM: p = 0.888 and p = 0.731, respectively). However, aortic reintervention rates were higher in the TEVAR group than in the open repair group before and after PSM (p = 0.006 and p = 0.013, respectively).

CONCLUSION

The TEVAR group was superior in short-term recovery outcomes but had higher reintervention rates compared to the open repair group. However, there were no significant differences in long-term survival between the two groups.

Preoperative Glomerular Filtration Rate and Outcome Following Open Abdominal Aortic Aneurysm Repair

Estimated glomerular filtration rate (eGFR) can be readily calculated from serum creatinine values. It is a more sensitive prognostic indicator than serum creatinine alone in patients undergoing thoracoabdominal or endovascular abdominal aortic aneurysm repair. The value of eGFR in patients undergoing open abdominal aortic aneurysm repair remains unclear. The preoperative eGFR was calculated for patients undergoing elective open infrarenal aortic aneurysm repair. Postoperative complications, perioperative mortality, and long-term survival were compared across eGFR and serum creatinine quartiles. The eGFR identified preoperative renal dysfunction in 33% of patients, whereas serum creatinine identified renal impairment in only 11%. The eGFR correlated with perioperative morbidity and long-term survival. Serum creatinine did not correlate with perioperative mortality or long-term survival. However, it did correlate with postoperative morbidity. The eGFR is a more sensitive index of preoperative renal function than serum creatinine and correlates with survival. It should replace serum creatinine as the standard index of renal function before open abdominal aortic aneurysm repair.

Preoperative Laboratory Testing

Obtaining routine preoperative laboratory tests increases health care costs and has been listed, by the Choosing Wisely Campaign, as one of the top 5 practices anesthesiologists should avoid. Routine testing without clinical indication is not cost-effective and could cause harm and unnecessary delays. Abnormal findings are more likely to be false positive and costly to pursue, introduce new risks, and increase anxiety for the patient. Preoperative testing need to be performed only following a targeted history and physical examination, factoring severity of surgery, and comorbidities such that the benefit of the test outweighs risk.

Outcomes Following Non-operative Management of Thoracic and Thoracoabdominal Aneurysms

BACKGROUND

Surgical decision making remains difficult in several patients with aneurysmal disease of the descending thoracic (DT) or thoracoabdominal (TA) aorta. Despite previous studies that have investigated aneurysms treated non-operatively using a prospective growth analysis, completeness and accuracy of follow-up were inconsistent. We aim to describe the survival and freedom from adverse aortic events in patients with DT and TA who did not undergo operative repair.

METHODS

This is a single-center retrospective analysis of all patients with either a descending degenerative atherosclerotic or dissection-related DT or TA aortic lesion who were treated non-operatively from April 2002 to December 2016. We studied patients who did not undergo operative repair of descending degenerative atherosclerotic or dissection-related DT or TA aortic lesion. Primary end points were overall survival and freedom from aortic-related mortality (ARM).

RESULTS

Of the 315 patients diagnosed with DT or TA disease, 56 (18%) did not undergo surgical repair. Mean aneurysm diameter was 65 mm ± 15 (range 50-120; IQR 5.4-7.15). Extent of the aortic aneurysms was DT in 36 (11%) patients and TA in 20 (6%). Median duration of follow-up was 12 months (range 1-108; IQR 3-36). Over the course of the study, 41 (73%) patients died for an overall survival rate of 53% ± 7 at 1 year (95% CI 40-65) and 23% ± 7 at 3 year (95% CI 17-42.5). Aortic-related mortality was 27% (n = 15), significantly higher in patients with aneurysms ≥ 60 mm [n = 13, (39%) vs. n = 2, (9%); P = 0.025; OR = 5.04]. Overall, estimated freedom from ARM was 81% ± 5.5 at 1 year (95% CI 68-89) and 66.5% ± 9 at 3 year (95% CI 48-81). Only TA extent was independently associated with freedom from ARM during the follow-up (P = 0.005; HR: 5.74; 95% CI 1.711-19.729).

CONCLUSIONS

Thoracoabdominal extent of the aneurysmal aortic disease is the most important predictor of ARM in unrepaired DT or TA aortic diseases. Mortality from aortic-related events was significantly more premature than mortality from non-aortic-related mortality.

State-of the-art review on the renal and visceral protection during open thoracoabdominal aortic aneurysm repair

During open thoracoabdominal aortic aneurysm repair (OTAAAR), there is an inevitable organ ischemic period that occurs when the abdominal arteries are being reattached to the aortic graft. Despite various protective techniques, the incidence of renal and visceral complications remains substantial. This state-of-the-art review gives an overview of the current and most evidence-based organ protection methods during OTAAAR, based on the most recent publications and personal experience. An electronic search was performed in four medical databases, using the following MeSH terms: thoracoabdominal aneurysm, TAAAR, visceral protection, renal protection, kidney, perfusion, and intestines. Every publication type was considered. The literature search was ended on August 31st, 2017. The left heart bypass (LHB) is currently the most frequent adjunct to provide distal aortic perfusion (DAP) during aortic clamping. Together with systemic hypothermia, it forms the cornerstone in organ protection during aortic clamping. Further renal protection can be obtained by selective renal perfusion (SRP) with cold blood or cold crystalloid solution, the latter enriched with mannitol. The perfusion should be administered in a volume- and pressure-controlled way and, if possible, by use of a pulsatile pump. Selective visceral perfusion (SVP) is not routinely used, as it does not provide adequate blood flow for visceral protection. The best way to protect the intestines is by minimizing the ischemic time. The preservation of renal and visceral function after OTAAAR can only be obtained with specific strategies before, during, and after the operation. This involves a series of measures, including selective digestive decontamination (SDD), avoidance of nephrotoxic drugs, minimizing the renal and intestinal ischemic time, systemic cooling, avoidance of hemodynamic instability, and regional protective perfusion of the kidneys. Future innovations in catheters, cardiac bypass flow types, mechanical components, hybrid vascular grafts, and pharmaceutical protection measures will hopefully further reduce organ complications.

Early Outcomes of the t-Branch Off-the-Shelf Multibranched Stent-Graft in Urgent Thoracoabdominal Aortic Aneurysm Repair

Purpose: To assess the short-term outcomes of the multibranched off-the-shelf t-Branch stent-graft for urgent thoracoabdominal aortic aneurysm (TAAA) repair and to evaluate the impact on outcomes of the learning curve and adherence to the instruction for use (IFU). Methods: Between 2014 and 2017, 42 patients (mean age 73.3±7 years; 26 men) underwent urgent TAAA treatment using the t-Branch stent-graft [18 in the early (2014–2015) period and 24 in the late (2016–2017) period]. Nearly half the patients were symptomatic (n=18) and 12 had contained rupture. Aneurysm diameter >80 mm was present in 12 (mean diameter 77.7±13.2 mm). Nineteen patients did not meet the IFU for the t-Branch due to target vessel anatomy. The primary endpoints were spinal cord ischemia (SCI), renal function impairment, and 30-day mortality. Target vessel patency and endoleak incidence were assessed at 30 days. Multivariate analyses examined associations between perioperative variables and outcomes; the results are presented as the odds ratio (OR) and 95% confidence interval (CI). Results: The technical success rate was 93% (39/42). Successful catheterization was achieved in 150/155 target vessels (97%). The postoperative SCI rate was 21% (5 paraplegia/4 transient paraparesis) and was correlated with age (OR 1.26, 95% CI 1.01 to 1.56, p=0.04). The renal function impairment rate was 23% (10/42; 2 temporary, 2 permanent dialysis) and was correlated with early experience (OR 7.74, 95% CI 1.3 to 43.9, p=0.019). The 30-day mortality was 14% (no intraoperative deaths); no factor was associated with mortality. During the first month, the incidences of type I, II, and III endoleaks were 0%, 43%, and 0%, respectively; branch patency was 99% (150/151). Procedure time decreased in the later experience (479±333 vs 407±25 minutes, p=0.09), though it was increased in cases outside the IFU (497±135 vs 389±118 minutes, p=0.009), along with fluoroscopy time (121±48 vs 92±33 minutes, p=0.036). Conclusion: Endovascular repair of urgent TAAA using the t-Branch is a feasible treatment option with acceptable 30-day mortality and morbidity in terms of SCI and renal function impairment. Adherence to the IFU prolonged procedure time but had no effect on outcomes. Increased experience of such cases over time may improve outcomes.

Renal protection in thoracoabdominal aortic aneurysm surgery

It is indisputable that open thoracoabdominal aortic aneurysm (TAAA) repair remains a highly complex and sophisticated surgical intervention. Despite advancements in the imaging modality, evolution of our understanding of the pathology afflicting the aorta, intraoperative brain and spinal cord monitoring, intraoperative organ protection, postoperative critical care and organ support, monitoring and the close follow-up of affected patients, this type of surgery remains a challenge to the surgeon and the patient. In this review, we will illustrate the recent evidence on renal protection and prediction during TAAA.

Preoperative Laboratory Testing

Routine preoperative testing is not cost-effective, because it is unlikely to identify significant abnormalities. Abnormal findings from routine testing are more likely to be false positive, are costly to pursue, introduce a new risk, increase the patient's anxiety, and are inconvenient to the patient. Abnormal findings rarely alter the surgical or anesthetic plan, and there is usually no association between perioperative complications and abnormal laboratory results. Incidental findings and false positive results may lead to increased hospital visits and admissions. Preoperative testing needs to be done based on a targeted history and physical examination and the type of surgery.

Endovascular Repair versus Open Repair for Isolated Descending Thoracic Aortic Aneurysm

PURPOSE

To compare the outcomes of thoracic endovascular aortic repair (TEVAR) with those of open repair for descending thoracic aortic aneurysms (DTAA).

MATERIALS AND METHODS

We compared the outcomes of 114 patients with DTAA and proximal landing zones 3 or 4 after TEVAR to those of 53 patients after conventional open repairs. Thirty-day and late mortality were the primary endpoints, and early morbidities, aneurysm-related death, and re-intervention were the secondary endpoints.

RESULTS

The TEVAR group was older and had more incidences of dissecting aneurysm. The mean follow-up was 36±26 months (follow-up rate, 97.8%). The 30-day mortality in the TEVAR and open repair groups were 3.5% and 9.4% (p=0.11). Perioperative stroke and paraplegia incidences were similar between the groups [5.3% vs. 7.5% (p=0.56) and 7.5% vs. 3.5% (p=0.26), respectively]. Respiratory failure occurred more in the open repair group (1.8% vs. 26.4%, p<0.01). The incidence of acute kidney injury requiring dialysis was higher in the open repair group (1.8% vs. 9.4%, p<0.01). The cumulative survival rate was higher in the TEVAR group at 2 to 5 years (79.6% vs. 58.3%, p=0.03). The free from re-intervention was lower in the TEVAR group (65.3% vs. 100%, p=0.02), and the free from aneurysm-related death in the TEVAR and open repair groups were 88.5% and 86.1% (p=0.45).

CONCLUSION

TEVAR is safe and effective for treating DTAAs with improved perioperative and long-term outcomes compared with open repair.

Cohort comparison of thoracic endovascular aortic repair with open thoracic aortic repair using modern end-organ preservation strategies

BACKGROUND

Pivotal trials showed that thoracic endovascular aortic repair (TEVAR) has improved outcomes compared with open surgery for treating descending thoracic aortic aneurysms. However, those trials included historical open controls in which modern end-organ preservation strategies were not routinely employed. To create a more level assessment, we compared our outcomes of elective TEVAR with modern open thoracic aortic repair (OTAR) controls.

METHODS

A retrospective review of thoracic aortic aneurysm patients undergoing TEVAR was compared with a contemporaneous cohort of OTAR patients. Partial bypass or hypothermic circulatory arrest was used in all OTAR patients. Cerebrospinal fluid drain placement was attempted in all patients. Preoperative characteristics, operative variables, and outcomes were recorded, and the Kaplan-Meier method was used for survival estimates.

RESULTS

The main outcome was mortality. Secondary outcomes included postoperative spinal cord ischemia (SCI) or stroke, and any persistent neurologic deficit 30 days following the operation. During the study period, 62 patients underwent TEVAR and 56 underwent OTAR with median follow-up of 23.7 months and 36.4 months, respectively. No difference existed between the TEVAR and OTAR with respect to overall neurologic complications (8.1% vs. 12.5%, P = 0.55) as well as any residual neurologic deficit at 30 days (0% vs. 5.4%, P = 0.10). TEVAR patients had fewer complications including pneumonia (P = 0.02), rebleeding (P = 0.02), and acute kidney injury (P = 0.001). There was no difference in 30-day mortality (1.6% vs. 8.9%, P = 0.10), 1-year mortality (12.2% vs. 14%, P = 0.80), or 5-year mortality (53.9% vs. 44%, P = 0.48) between TEVAR and OTAR, respectively.

CONCLUSIONS

TEVAR continues to show improved perioperative outcomes with a trend toward decreased 30-day mortality and fewer major adverse events compared with OTAR. However, with the routine use of end-organ preservation strategies during OTAR, neurologic deficits, particularly SCI, can be safely reduced to comparable levels with those of TEVAR and 1-year all-cause mortality rates are similar between the groups. These OTAR results may serve as a benchmark as TEVAR is increasingly applied for other aortic pathologies, such as chronic dissection, wherein long-term efficacy is not proven.

Thoracoabdominal aortic aneurysm repair: current endovascular perspectives

Thoracoabdominal aneurysms account for roughly 3% of identified aneurysms annually in the United States. Advancements in endovascular techniques and devices have broadened their application to these complex surgical problems. This paper will focus on the current state of endovascular thoracoabdominal aneurysm repair, including specific considerations in patient selection, operative planning, and perioperative complications. Both total endovascular and hybrid options will be considered.

The impact of acute renal failure on early and late outcomes after thoracic aortic endovascular repair

BACKGROUND

The incidence of acute kidney injury (AKI) after thoracic aortic endovascular repair (TEVAR) is variably reported at 1% to 34%. This study utilized the RIFLE (risk, injury, failure) criteria to evaluate the incidence, risk factors, and late implications of AKI after TEVAR.

METHODS

In all, 350 patients without prior dialysis requirement underwent TEVAR (1993 to 2013). The mean age was 68.7 years (54% male). The mean preoperative glomerular filtration rate was 76.5 ± 37.6 mL/min, with 39 patients (11.7%) in chronic kidney stage 3 or 4. The TEVAR was performed for rupture in 20.6%. The mean contrast volume administered was 95.7 ± 52.9 mL.

RESULTS

Early mortality was seen in 17 patients (4.9%). Acute kidney injury defined as RIFLE classes risk, injury, or failure was seen in 59 patients (17%; risk = 36, injury = 14, failure = 9). Independent predictors of AKI included history of saccular aneurysm, presentation with rupture, or need for arch repair or red blood cell transfusion (all p < 0.05). Only 2 patients (0.6%) needed dialysis, with none requiring permanent dialysis. Importantly, 10-year freedom from dialysis was 97.7%. Development of AKI predicted early mortality (p < 0.001, odds ratio 9.8). Ten-year survival was 38.1%. Both injury and failure AKI classes independently predicted late mortality (p < 0.05).

CONCLUSIONS

The prevalence of AKI after TEVAR as assessed by RIFLE criteria is higher than seen in previous reports. Despite its infrequent progression to permanent dialysis dependence, AKI remains an important risk factor for both early and late mortality. Future studies should evaluate strategies to reduce the incidence of AKI after TEVAR to improve both early and late outcomes.

Preoperative estimates of glomerular filtration rate as predictors of outcome after surgery: a systematic review and meta-analysis

BACKGROUND

Kidney dysfunction is a strong determinant of prognosis in many settings.

METHODS

A systematic review and meta-analysis was undertaken to explore the relationship between estimated glomerular filtration rate (eGFR) and adverse outcomes after surgery. Cohort studies reporting the relationship between eGFR and major outcomes, including all-cause mortality, major adverse cardiovascular events, and acute kidney injury after cardiac or noncardiac surgery, were included.

RESULTS

Forty-six studies were included, of which 44 focused exclusively on cardiac and vascular surgery. Within 30 days of surgery, eGFR less than 60 m l · min · 1.73 m(-2) was associated with a threefold increased risk of death (multivariable adjusted relative risk [RR] 2.98; 95% confidence interval [CI] 1.95-4.96) and acute kidney injury (adjusted RR 3.13; 95% CI 2.22-4.41). An eGFR less than 60 ml · min · 1.73(-2) m was associated with an increased risk of all-cause mortality (adjusted RR 1.61; 95% CI 1.38-1.87) and major adverse cardiovascular events (adjusted RR 1.49; 95% CI 1.32-1.67) during long-term follow-up. There was a nonlinear association between eGFR and the risk of early mortality such that, compared with patients having an eGFR more than 90 ml · min · 1.73m(-2) the pooled RR for death at 30 days in those with an eGFR between 30 and 60 ml · min · 1.73 m(-2) was 1.62 (95% CI 1.43-1.80), rising to 2.85 (95% CI 2.49-3.27) in patients with an eGFR less than 30 ml · min · 1.73 m(-2) and 3.75 (95% CI 3.44-4.08) in those with an eGFR less than 15 ml · min · 1.73 m(-2).

CONCLUSION

: There is a powerful relationship between eGFR, and both short- and long-term prognosis after, predominantly cardiac and vascular, surgery.

Effectiveness of non-cardiac preoperative testing in non-cardiac elective surgery: a systematic review

Elective surgery is usually preceded by preoperative diagnostics to minimize risk. The results are assumed to elicit preventive measures or even cancellation of surgery. Moreover, physicians perform preoperative tests as a baseline to detect subsequent changes. This systematic review aims to explore whether preoperative testing leads to changes in management or reduces perioperative mortality or morbidity in unselected patients undergoing elective, non-cardiac surgery. We systematically searched all relevant databases from January 2001 to February 2011 for studies investigating the relationship between preoperative diagnostics and perioperative outcome. Our methodology was based on the manual of the Ludwig Boltzmann Institute for Health Technology Assessment, the Scottish Intercollegiate Guidelines Network (SIGN) handbook, and the PRISMA statement for reporting systematic reviews. One hundred and one of the 25 281 publications retrieved met our inclusion criteria. Three test grid studies used a randomized controlled design and 98 studies used an observational design. The test grid studies show that in cataract surgery and ambulatory surgery, there are no significant differences between patients with indicated preoperative testing and no testing regarding perioperative outcome. The observational studies do not provide valid evidence that preoperative testing is beneficial in healthy adults undergoing non-cardiac surgery. There is no evidence derived from high-quality studies that supports routine preoperative testing in healthy adults undergoing non-cardiac surgery. Testing according to pathological findings in a patient's medical history or physical examination seems justified, although the evidence is scarce. High-quality studies, especially large randomized controlled trials, are needed to explore the effectiveness of indicated preoperative testing.

Predictors and outcomes of acute kidney injury after thoracic aortic endograft repair

BACKGROUND

This study analyzed the incidence and the predictive factors of postoperative acute kidney injury (AKI) after thoracic endovascular aortic repair (TEVAR) and evaluated the effect of AKI on postoperative survival.

METHODS

Between November 2000 and April 2011, all consecutive patients undergoing TEVAR of the descending thoracic or thoracoabdominal aorta were enrolled at four teaching hospitals. Estimated glomerular filtration rate (eGFR) was evaluated during the entire hospitalization. AKI was defined by the RIFLE (Risk, Injury, Failure, Loss of function, End-stage renal disease) consensus criteria.

RESULTS

The study included 171 patients (80% men) who were a mean age of 69±14 years (range, 18-87 years). AKI occurred in 24 patients (14%). Independent predictors of postoperative AKI were preoperative depressed eGFR, thoracoabdominal extent, and postoperative transfusion. Patients with AKI experienced major postoperative complications (P=.001), longer hospitalization (P=.008), and higher hospital mortality (29% vs 4%; P<.001). Kaplan-Meier analysis showed a survival of 82%, 51%, and 51% at 1, 3, and 5 years for patients who developed AKI, which was significantly worse than the 99%, 89%, and 80% for patients who did not experience AKI (P=.001).

CONCLUSIONS

Preoperative poor renal function, blood transfusions, and the thoracoabdominal extent of the aortic disease were the most important predictors for AKI.

Continued favorable results with open surgical repair of type IV thoracoabdominal aortic aneurysms

OBJECTIVES

Type IV thoracoabdominal aortic aneurysm (TAAA) repair, despite low risk of spinal cord ischemia (SCI), is reported to have significant morbidity and mortality. This has led some to apply adjuncts (eg, extracorporeal circulation) used in more extensive TAAA repair or to consider alternative approaches, such as hybrid operations. We have used a consistent, simplified surgical approach to type IV TAAA, and the goal of the present study is to review experience over 2 decades with such treatment and to identify correlates of surgical morbidity.

METHODS

All type IV repairs at Massachusetts General Hospital from January 1989 through September 2009 were evaluated for clinical features, technical operative details, and 30-day outcomes. Logistic regression identified predictors of morbidity. Survival was assessed using Kaplan-Meier analysis.

RESULTS

A total of 179 patients underwent type IV repair, with elective repair in 156 (87%) and urgent in 23 (13%). The clamp-and-sew technique was used for all operations, with routine hypothermic renal perfusion. Clinical features were age 73 ± 8 years, coronary artery disease in 89 (50%), and creatinine level >1.8 mg/dL defining chronic renal insufficiency (CRI) in 32 (18%). Operative reconstruction in 166 (93%) consisted of one beveled proximal anastomosis incorporating the descending thoracic aorta, celiac, superior mesenteric artery, and right renal arteries origins (mean visceral clamp time, 36 ± 12 minutes) and a side-arm graft to the left renal artery. Technical details included previous abdominal aortic aneurysm (AAA) repair in 52 (29%), operative time of 290 ± 90 min, estimated blood loss of 2.7 ± 1.4 L, and splenectomy in 57 (32%). The 30-day outcomes were death in 5 (2.8%), myocardial infarction in 6 (3.4%), hemodialysis in 5 (2.8%), and any degree of SCI in 4 (2.2%). Regression analysis identified a history of CRI as an independent predictor of postoperative complication or death (odds ratio, 3.4; 95% confidence interval, 1.4-8). Survival rates at 1, 5, and 10 years were 89% ± 2%, 62% ± 4%, and 36% ± 5%, respectively.

CONCLUSIONS

A simplified operative approach for type IV TAAA repair is associated with favorable perioperative results. These data refute the need for surgical adjuncts commonly applied in more extensive TAAA and indicate that the hybrid operation is an illogical posture. CRI should figure prominently in clinical decision making. Long-term survival equates that observed after routine AAA repair.

Endovascular treatment of thoracoabdominal aneurysm

OPINION STATEMENT

The use of endovascular modalities for the treatment of simple descending thoracic aneurysms has become standard of care. Expanding endovascular techniques for the treatment of thoracoabdominal aneurysms is now possible with the evolution of branched and fenestrated grafts.

The use of early intervention to prevent postoperative complications

PURPOSE OF REVIEW

The incidence of complications following major surgery is surprisingly high. Patients who develop complications suffer a reduction in long-term survival. This review aims to explore recent advances in the management of surgical patients aimed at preventing postoperative complications.

RECENT FINDINGS

Identifying patients prior to surgery who are at risk of a poor outcome remains challenging. There are a number of scoring systems to assist clinical risk assessment. Recent work has investigated the use of plasma biomarkers for perioperative risk prediction. Therapies aimed at reducing complication rates by attempting to improve tissue oxygen delivery include goal-directed haemodynamic therapy and postoperative noninvasive ventilation. The role of perioperative beta-adrenoceptor antagonists remains unclear. Other important measures include the use of a surgical safety checklist and thromboprophylaxis.

SUMMARY

Current systems for the identification and treatment of high-risk surgical patients are inadequate. Further research is required to establish the optimal approach to the identification and management of the high-risk surgical patient.

Chronic kidney disease classification stratifies mortality risk after elective stent graft repair of the thoracic aorta

OBJECTIVE

Risk factors for perioperative and late mortality after thoracic endovascular aortic repair (TEVAR) remain ill-defined. In this study, we examined the prognostic significance of chronic kidney disease (CKD), a well-known predictor of death after thoracic aorta open repair, employing a stratification based on CKD stages derived from glomerular filtration rate (GFR) values.

METHODS

A prospective database was evaluated for 179 consecutive patients electively submitted to TEVAR between 1999 and 2007. Preoperative GFR was estimated by using the Cockcroft-Gault equation. Patient groups were stratified into four quartiles by baseline serum creatinine (SC) and GFR values, with quartile I being the lowest, and quartile IV the highest, and into the five CKD stages in reverse order (I GFR >or= 90 ml/min/1.73 m(2); II 60-89; III 30-59; IV 15-29; V < 15). Prognostic significance of preoperative GFR values and CKD stages were investigated by means of univariate and multivariate analyses, and the Kaplan-Meier log-rank method.

RESULTS

A primary technical success was achieved in 166 of 179 patients (92.7%), and an initial clinical success in 158 (88.3%). Thirty-day mortality was 5% (nine cases). Paraplegia or paraparesis were observed in 11 (6.1%) patients, and completely resolved in six cases after cerebrospinal fluid drainage. Preoperative GFR quartiles and CKD stages were significant predictors of 30-day mortality (P = .004 and P < .0001 respectively), whereas SC quartiles did not affect the outcome (P = .12). In particular, GFR quartile I (<60 ml/min/1.73 m(2)) was associated with a ten-fold greater risk of perioperative death compared with the other three quartiles (Odds Ratio 11.4, 95% Confidence Interval 2.3-57.0, P = .003). Midterm survival was 88.8% (159 of 179) at a mean follow-up of 35.6 +/- 23.7 months. Actuarial survival at 60 months was 57.8%, 81.1%, 92.3%, and 100% for GFR quartiles I to IV respectively (P < .0001), and 0.0%, 66.7%, 59.2%, 88.6%, and 100% (P < .0001) for CKD stage V to I respectively. At univariate analyses, age (P = .019), preoperative SC quartiles (P = .001), GFR quartiles (P = .0002), and CKD stages (P < .0001) were all predictive of mid-term mortality. At multivariate Cox proportional hazards regression analysis, only CKD stages remained independently associated with the outcome (P = .008).

CONCLUSIONS

GFR is an accurate prognostic predictor in patients submitted to TEVAR. Also, perioperative and midterm mortality directly correlate with the severity of CKD stages, allowing a risk stratification model to be employed both for risk-adjusted preoperative evaluation, and to establish accurate matching criteria for comparative studies.

Comparison of the effects of open and endovascular aortic aneurysm repair on long-term renal function using chronic kidney disease staging based on glomerular filtration rate

OBJECTIVE

It has been suggested that endovascular aneurysm repair (EVAR) in concert with serial contrast-enhanced computed tomography (CT) surveillance adversely impacts renal function. Our primary objectives were to assess serial renal function in patients undergoing EVAR and open repair (OR) and to evaluate the relative effects of method of repair on renal function.

METHODS

A thorough retrospective chart review was performed on 223 consecutive patients (103 EVAR, 120 OR) who underwent abdominal aortic aneurysm (AAA) repair. Demographics, pertinent risk factors, CT scan number, morbidity, and mortality were recorded in a database. Baseline, 30- and 90-day, and most recent glomerular filtration rate (GFR) were calculated. Mean GFR changes and renal function decline (using Chronic Kidney Disease [CKD] staging and Kaplan-Meier plot) were determined. EVAR and OR patients were compared. CKD prevalence (>or=stage 3, National Kidney Foundation) was determined before repair and in longitudinal follow-up. Observed-expected (OE) ratios for CKD were calculated for EVAR and OR patients by comparing observed CKD prevalence with the expected, age-adjusted prevalence.

RESULTS

The only baseline difference between EVAR and OR cohorts was female gender (4% vs 12%, P = .029). Thirty-day GFR was significantly reduced in OR patients (P = .047), but it recovered and there were no differences in mean GFR at a mean follow-up of 23.2 months. However, 18% to 39% of patients in the EVAR and OR groups developed significant renal function decline over time depending on its definition. OE ratios for CKD prevalence were greater in AAA patients at baseline (OE 1.28-3.23, depending upon age group). During follow-up, the prevalence and severity of CKD increased regardless of method of repair (OE 1.8-9.0). Deterioration of renal function was independently associated with age >70 years in all patients (RR 2.92) and performance of EVAR compared with OR (RR 3.5) during long-term follow-up.

CONCLUSIONS

Compared with EVAR, OR was associated with a significant but transient fall in GFR at 30 days. Renal function decline after AAA repair was common, regardless of method, especially in patients >70 years of age. However, the renal function decline was significantly greater by Kaplan-Meier analysis in EVAR than OR patients during long-term follow-up. More aggressive strategies to monitor and preserve renal function after AAA repair are warranted.

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.

β-Blockers improve outcomes in kidney disease patients having noncardiac vascular surgery

Beta-blockers are known to improve postoperative outcome after major vascular surgery. We studied the effects of beta-blockers in 2126 vascular surgery patients with and without kidney disease followed for 14 years. Creatinine clearance was calculated using the Cockcroft-Gault equation, and kidney function was categorized as Stage 1 for a reference group of 550 patients, Stage 2 with 808 patients, Stage 3 with 627 patients, and combined Stages 4 and 5 with 141 patients. Outcome measures were 30-day and long-term all-cause mortality with a mean follow-up of 6 years. Cox proportional hazards models were used to control cardiovascular risk factors, including propensity for beta-blocker use. In all, 129 (6%) and 1190 (56%) patients died respectively. Mortality rates were three- and two-fold higher, respectively, for patients at Stages 3-5 compared to the reference group for the two outcomes. beta-Blocker use was significantly associated with a lower risk of mortality after surgery. The overall adjusted hazard ratio was 0.35 and 0.62, respectively, for individuals at Stages 3-5 compared to the reference group for 30-day and long-term mortality. This study shows that kidney function is a predictor of all-cause mortality and beta-blocker use is associated with a lower risk of death in kidney disease patients undergoing elective vascular surgery.

Targeted renal therapy and contrast-induced nephropathy during endovascular abdominal aortic aneurysm repair: results of a feasibility pilot trial

PURPOSE

To evaluate the feasibility of targeted renal therapy (TRT) to decrease the rate of contrast-induced nephropathy (CIN) during endovascular aortic aneurysm repair (EVAR) in patients at risk for CIN.

METHODS

A prospective nonrandomized analysis of TRT was performed in 10 high-risk patients (8 men; median age 66.5 years, range 56-80) with pre-existing renal insufficiency. TRT involved high-dose intrarenal artery infusions of fenoldopam (FEN), a short acting selective dopamine-1 agonist and renal arteriolar vasodilator, delivered percutaneously via a left brachial access using the 5-F Benephit PV Infusion System during EVAR.

RESULTS

There were no device-related complications. TRT infusion duration ranged from 3.5 to 6.0 hours (median 4.5). Median contrast dosage was 120 mL (range 50-200). At 24 and 72 hours after EVAR, creatinine clearance (CrCl) had improved in 7 (70%) patients, remained unchanged in 2 (20%), and declined >25% in 1 (10%); the latter returned to baseline on day 5. At 30 days, 7 (70%) patients had improved CrCl and 3 (30%) remained unchanged.

CONCLUSION

TRT is feasible during EVAR in high-risk patients. Further investigation is warranted to determine the safety and efficacy of TRT in preserving renal function during EVAR.

Early Results after Staged Hybrid Repair of Thoracoabdominal Aortic Aneurysms

BACKGROUND

The morbidity and mortality rates associated with open thoracoabdominal aortic aneurysm (TAAA) repair are substantial. This study was designed to review our early experience with the hybrid endovascular and, or open approach for TAAA repair.

STUDY DESIGN

Patients undergoing elective hybrid repair of their TAAAs were retrospectively reviewed.

RESULTS

Seventeen patients (mean age 69+/-15 years, male, 76%) underwent visceral and renal revascularization as the first stage of their hybrid repair. The Crawford extent included: II, 2; III, 8; and IV, 7. Perioperative mortality and complication rates after the first stage were 24% and 25%, respectively; the mean intensive care unit stay and total length of stay were 7+/-12 days (range 1 to 45 days) and 22+/-33 days (range 3 to 100 days), respectively. The endovascular aneurysm repair or second stage procedure was performed in 12 of 13 (92%) of the surviving patients, with a mean of 27+/-27 days (range 6 to 99 days) between the procedures. Two patients experienced intraoperative complications during the second stage, but there were no deaths or additional postoperative complications. Patients did not require the intensive care unit, and the overall mean length of stay after the second stage was 2+/-2 days (range 1 to 5 days). The mean postoperative followup among the 11 patients completing both stages was 8+/-12 months (range 1 to 15 months). The primary patency rate for the visceral and renal bypasses was 96% (54 of 56).

CONCLUSIONS

The hybrid approach for patients with TAAAs may reduce complications in the average, low-risk patient and may extend the indications for repair to patients considered higher risk based on age, comorbidities, or anatomic considerations.

Role of Somatosensory Evoked Potentials in Predicting Outcome During Thoracoabdominal Aortic Repair

BACKGROUND

Clinical utility of somatosensory evoked potentials (SSEP) in descending thoracic and thoracoabdominal aortic repair is debated. We reviewed our practical experience with SSEP in descending thoracic and thoracoabdominal aortic repairs.

METHODS

Between January 2000 and April 2005, we used SSEP monitoring in 444 patients (270 thoracoabdominal aorta and 174 descending thoracic aorta). Median age was 68 years; 36% were female. Only changes of spinal origin were analyzed. Changes were classified as (1) no change, (2) transient changes that returned to baseline by the end of the procedure, or (3) persistent changes that did not return to baseline by the end of the procedure.

RESULTS

Somatosensory evoked potential changes occurred in 87 (19.6%) patients; 22 (25%) of these did not return to baseline. Immediate neurologic deficit occurred in 8 of 444 patients (1.8%); five deficits (5 of 87; 5.8%) occurred in patients with SSEP changes, compared with three deficits (3 of 357; 0.8%) in patients without changes. Odds ratio for this comparison was 7.2 (p < 0.002). Somatosensory evoked potential was a poor screening tool for neurologic deficit, with a sensitivity of 62.5% and specificity 81.2%. Negative predictive value was 99.2%, indicating a very low event probability in the absence of SSEP changes. Delayed neurologic deficit occurred in 3.2% and was not related to SSEP changes. Somatosensory evoked potential changes were also associated with increased 30-day mortality and low glomerular filtration rate.

CONCLUSIONS

Intraoperative SSEP monitoring was reliable in ruling out spinal injury in descending thoracic and thoracoabdominal aortic repair, but had a low sensitivity. It did not predict delayed neurologic deficit. Spinal SSEP change was an independent predictor of mortality and correlated with low preoperative glomerular filtration rate.