Incidence and risk factors of renal dysfunction after thoracic endovascular aortic repair

Hybrid type II and frozen elephant trunk in acute Stanford type A aortic dissections

Objectives. Composite frozen elephant trunk is an increasingly popular solution for complex aortic pathologies. This review aims to compare outcomes of zone 0 type II hybrid (hybrid II) with the composite frozen elephant trunk (FET) technique in managing acute Stanford type A aortic dissections. Methods. PubMed and Embase were systematically searched using PRISMA protocol. 11 relevant studies describing the outcomes of hybrid II arch repair and FET techniques in patients with type A aortic dissection were included in the meta-analysis. The study focused on early post-operative 30-day outcomes analysing mortality, stroke, spinal cord injury, renal impairment requiring dialysis, bleeding and lung infection. Results. 1305 patients were included in the analysis - 343 receiving hybrid II repair and 962 treated with the FET. Meta-analysis of proportions showed Hybrid II was associated with less early mortality [5.0 (CI 3.1-7.8) vs 8.1 (CI 6.5-10.0) %], stroke [2.3 (CI 1.1-4.6) vs 7.0 (CI 5.5-8.8) %], spinal cord injury [2.0 (CI 0.9-4.3) vs 3.8 (CI 2.8-5.3) %], renal impairment requiring dialysis [7.9 (CI 5.5-11.2) vs 11.8 (CI 9.8-14.0) %], reoperation for bleeding [3.9 (CI 1.8-8.4) vs 10.6 (CI 8.1-13.8) %] and lung infection [14.8 (CI 10.8-20.0) vs 20.7 (CI 16.9-25.1) %]. Conclusion. Hybrid II should be considered in favour of FET technique in acute Stanford type A dissection patients who are at higher risk due to age and comorbidities.

Perioperative management of patients undergoing thoracic endovascular repair

Thoracic endovascular aortic repair (TEVAR) is a less invasive method for treating thoracic and some thoracoabdominal aortic aneurysms, dissections of the thoracic aorta and blunt traumatic aortic injury, compared with conventional open surgery. Maximizing the likelihood of a successful outcome requires diligent multidisciplinary (surgical, critical care, nursing, pharmacy, nutrition and physical therapy) perioperative care. In this article, we discuss fundamentals for managing patients after endovascular aortic aneurysm repair. These principles focus on the transition between the operating room and the intensive care unit, prevention and management of spinal cord deficits (SCD), and vital neurological, respiratory, cardiovascular, renal, gastrointestinal and hematological concerns. The better the care team understands the expected postoperative course, the earlier that deviations can be recognized and the more likely that successful rescue can be achieved to reduce the incidence and severity of adverse outcomes. Achieving optimal results after TEVAR requires attention to detail across the preoperative, intraoperative and postoperative phases of care.

Influence of baseline kidney dysfunction on perioperative renal outcomes after endovascular aneurysm repair with suprarenal fixation

BACKGROUND

Conflicting evidence exists regarding the comparative effects of endovascular aneurysm repair (EVAR) with and without suprarenal fixation. We compare outcomes in patients treated by EVAR with baseline normal kidney function and moderate and severe chronic kidney disease.

METHODS

Patients with normal kidney function (glomerular filtration rate [GFR] ≥60 mL/min/1.73 m²) or moderate (GFR = 30-59 mL/min/1.73 m²) or severe (GFR <30 mL/min/1.73 m²) kidney disease who underwent EVAR (N = 5534) were identified from the American College of Surgeons National Surgical Quality Improvement Program targeted database (2011-2015). Groups were determined by the presence (Cook Zenith [Cook Medical, Bloomington, Ind] or Medtronic Endurant [Medtronic, Minneapolis, Minn]) or absence (Gore Excluder [W. L. Gore & Associates, Flagstaff, Ariz]) of a suprarenal fixation system. Postoperative renal complications, defined as rise in creatinine concentration of >2 mg/dL without dialysis or new dialysis requirements, were analyzed within the first 30 days with results stratified by degree of kidney disease.

RESULTS

A total of 5534 patients underwent EVAR, with 3225 (58.3%) receiving a device using a suprarenal fixation system. Suprarenal fixation systems were less commonly used for symptomatic patients (11.0% vs 13.7%; P = .002) and patients with ruptured abdominal aortic aneurysm (4.5% vs 6.3%; P = .01). There was no difference in baseline kidney function between groups. EVAR with suprarenal fixation was associated with more renal complications (1.40% vs 0.65%; P = .008). In subgroup analysis, patients with moderate kidney dysfunction (n = 1780) had more renal complications (2.2% vs 0.8%; P = .02) with suprarenal fixation systems. No differences were seen in patients with normal kidney function (0.4% vs 0.2%; P = .32; n = 3597) or severe kidney dysfunction (14.3% vs 10.2%; P = .45; n = 157). This difference was driven mostly by postoperative elevation of creatinine concentration (0.6% vs 0.2%; P = .03) without requirements for new dialysis (0.8% vs 0.4%; P = .08). After adjustments with multivariate logistic regression models, EVAR with suprarenal fixation was associated with more renal complications (odds ratio, 2.65; 95% confidence interval, 1.32-5.34).

CONCLUSIONS

In our study, EVAR with suprarenal fixation devices was associated with more perioperative renal complications in patients with moderate kidney dysfunction. Long-term evaluation of these patients undergoing EVAR should be considered.

The Clinical Utility and Assessment of Renal Biomarkers in Acute Kidney Injury After Abdominal Endovascular Aneurysm Repair. A Systematic Review

The widespread adoption of endovascular aneurysm repair (EVAR) for abdominal aortic aneurysms (AAA) is due to the obvious advantages of the procedure compared to the traditional open repair. However, these advantages have to be weighed against the increased risk of renal dysfunction with EVAR. The evaluation of the perioperative renal function after EVAR has been hampered by the lack of sensitive and specific biochemical markers of acute kidney injury (AKI). The purpose of this study was to summarize all novel renal biomarkers and to evaluate their clinical utility for the assessment of the kidney function after EVAR. A systematic review of the current literature, as the Preferred Reporting Items for Systematic Reviews and Meta-Analyses statement guidelines, was performed to identify relevant studies with novel renal biomarkers and EVAR. Pubmed and Scopus databases were systemically searched. Studies reporting on thoracic endovascular aortic repair (TEVAR), case reports, case series, letters to the editor, and systematic reviews were excluded. Neutrophil-Gelatinase-Associated Lipocalin, Cystatin C, Liver-type fatty-acid-binding protein were the most common among the eligible studies while Interleukin-18, Retinol binding protein, N-acetyle-b-D-glucosaminidase and microalbumin have a sparse appearance in the literature. These biomarkers have been assessed in plasma as well as urine samples with each sample material having its own advantages and drawbacks. Which of these biomarkers has the most potential for assessing postoperative renal failure after EVAR, remains to be proved. The few studies presented in the literature show the potential clinical utility of these biomarkers, but larger studies with longer follow-up are required to determine the precise relationship between these biomarkers and postoperative acute kidney injury.

Impact of renal dysfunction on surgical outcomes in patients with aortic dissection

Preoperative renal dysfunction is associated with mortality in patients who undergo coronary artery bypass graft and valve surgery. However, the role of preoperative renal dysfunction in type A aortic dissection (TAAD) remains unclear. This study aimed to evaluate the impact of preoperative renal dysfunction on the outcome of surgical intervention in patients with TAAD.We retrospectively studied the outcomes of 159 patients with TAAD who were treated at a tertiary referral hospital between 2005 and 2010. The demographics and surgical details of patients were analyzed according to their renal function. Risk factors for outcomes were analyzed using multivariable logistic regression. Thirty-two of the patients (20.1%) had preoperative serum creatinine of 1.5 mg/dL or more. The multivariable logistic regression model revealed independent risk factors of in-hospital mortality to be renal dysfunction (odds ratio [OR], 3.79; 95% confidence interval [CI], 1.64-8.77), preoperative shock (OR, 8.75; 95% CI, 2.83-27.02), and bypass time (OR, 1.008; 95% CI, 1.003-1.013). In addition, patients with renal dysfunction exhibited a lower 90-day survival rate than did patients without the condition (P of log-rank test = .005).Preoperative renal dysfunction may have a critical role in the surgical outcomes of patients with TAAD. Additional large-scale investigations are warranted.

Repair of abdominal aortic aneurysms: preoperative imaging and evaluation

Imaging is a critical component of the pre-procedure evaluation and planning of endovascular aneurysm repair (EVAR). Imaging is the mainstay for proper assessment of procedural candidacy, relevant vascular anatomy, device selection, and surgical approach. Computed tomography angiography (CTA) has long been considered the preferred modality for pre-operative imaging and evaluation prior to EVAR. Recently, advances in image quality and software technology have further enhanced the proceduralist's ability to plan and perform EVAR. In this review, we highlight the current state of the art to provide interventionalists a contemporary assessment of the available tools for pre-operative imaging and evaluation prior to EVAR.

Risk factors and early outcomes of acute renal injury after thoracic aortic endograft repair for type B aortic dissection

Background

Thoracic endovascular aortic repair (TEVAR) has become an emerging treatment modality for acute type B aortic dissection (TBAD) patients in recent years. The risk factors and impacts of acute kidney injury (AKI) after percutaneous TEVAR, however, have not been widely established.

Methods

We retrospectively studied the clinical records of 305 consecutive patients who admitted to our institution and had TEVAR for TBAD between December 2009 and June 2013. The patients were routinely monitored for their renal functions preoperatively until 7 days after TEVAR. The Kidney Disease Improving Global Guidelines (KDIGO) criteria were used for AKI.

Results

Of the total 305 consecutive patients, 84 (27.5%) developed AKI after TEVAR, comprising 66 (21.6%) patients in KDIGO stage 1, 6 (2.0%) patients in stage 2 and 12 (3.9%) patients in stage 3. From the logistic regression analysis, systolic blood pressure (SBP) on admission >140 mmHg (odds ratio [OR], 2.288; 95% CI, 1.319–3.969) and supra-aortic branches graft bypass hybrid surgery (OR, 3.228; 95% CI, 1.526–6.831) were independent risk factors for AKI after TEVAR. Local anesthesia tended to be a protective factor (OR, 0.563; 95% CI, 0.316–1.001). The preoperative renal function, angiotensin-converting enzyme inhibitor/angiotensin receptor blocker or statin administration, volume of contrast agent, range of TBAD and false lumen involving renal artery were not associated with post-operation AKI. The in-hospital mortality and major adverse events were markedly increased with the occurrence of AKI (7.1% vs 0.9%, P=0.006; 14.3% vs 3.2%, P<0.001, respectively).

Conclusions

TEVAR for TBAD has a high incidence of AKI, which is associated with worse in-hospital outcomes. SBP on admission and supra-aortic branches graft bypass hybrid surgery were the most significant risk factors. Renopreventive measures should be considered in high-risk patients.

Progression to stage 3 and 4 chronic kidney disease and risk factor stratification following endovascular aortic aneurysm repair

Background

Risk of progression to various stages of chronic kidney disease (CKD) after endovascular aortic aneurysm repair (EVAR) is unknown. This study estimates progression rates to stage 3 and 4 CKD after EVAR and identifies potential predictors for progression.

Methods

EVAR cases (2006–2012) were retrospectively reviewed. Freedom of progression to CKD was estimated using Kaplan–Meier analysis, and predictors for progression were identified using Cox proportional hazards model.

Results

Two hundred and twelve consecutive patients at a single academic institution underwent EVAR for infrarenal aneurysms. Estimated freedom from progression to stage 3 CKD was 80%, 76%, and 63% at 6, 12, and 18 months, respectively, and for stage 4, 97%, 96%, and 93% at 6, 12, and 18 months, respectively. Stage 3 CKD predictors of progression included age (odds ratio (OR): 1.106, p = 0.001), diabetes (OR: 3.052, p = 0.04), perioperative use of angiotensin converting enzyme inhibitors or angiotensin receptor blockers (OR: 3.249, p = 0.02), and operative blood loss (OR: 1.002, p < 0.01). Stage 4 predictors included preoperative hemoglobin (OR: 0.473, p = 0.04) and baseline renal function (OR: 0.928, p = 0.001). Intraoperative contrast administration did not impact CKD development.

Conclusions

Progression to stage 3 CKD after EVAR occurs more frequently and at a higher rate compared with progression to stage 4. Different risk factors are associated with progression to each of those stages of CKD.

The Risk Factors and Outcomes of Acute Kidney Injury after Thoracic Endovascular Aortic Repair

Background

We aimed to evaluate the incidence, predictive factors, and impact of acute kidney injury (AKI) after thoracic endovascular aortic repair (TEVAR).

Methods

A total of 53 patients who underwent 57 TEVAR operations between 2008 and 2015 were reviewed for the incidence of AKI as defined by the RIFLE (risk, injury, failure, loss, and end-stage kidney disease risk) consensus criteria. The estimated glomerular filtration rate was determined in the perioperative period. Comorbidities and postoperative outcomes were retrospectively reviewed.

Results

Underlying aortic pathologies included 21 degenerative aortic aneurysms, 20 blunt traumatic aortic injuries, six type B aortic dissections, five type B intramural hematomas, three endoleaks and two miscellaneous diseases. The mean age of the patients was 61.2±17.5 years (range, 15 to 85 years). AKI was identified in 13 (22.8%) of 57 patients. There was an association of preoperative stroke and postoperative paraparesis and paraplegia with AKI. The average intensive care unit (ICU) stay in patients with AKI was significantly longer than in patients without AKI (5.3 vs. 12.7 days, p=0.017). The 30-day mortality rate in patients with AKI was significantly higher than patients without AKI (23.1% vs. 4.5%, p=0.038); however, AKI did not impact long-term survival.

Conclusion

Preoperative stroke and postoperative paraparesis and paraplegia were identified as predictors for AKI. Patients with AKI experienced longer average ICU stays and greater 30-day mortality than those without AKI. Perioperative identification of high-risk patients, as well as nephroprotective strategies to reduce the incidence of AKI, should be considered as important aspects of a successful TEVAR procedure.

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.

Potentially modifiable risk factors for acute kidney injury after surgery on the thoracic aorta: a propensity score matched case-control study

Perioperative risk factors were identified for acute kidney injury (AKI) defined by the RIFLE criteria (RIFLE = risk, injury, failure, loss, end stage) after surgery on the thoracic aorta with cardiopulmonary bypass (CPB) in this case-control study. A retrospective review was completed for 702 patients who underwent surgery on the thoracic aorta with CPB. A total of 183 patients with AKI were matched 1:1 with patients without AKI by a propensity score. Matched variables included age, gender, body-mass index, preoperative creatinine levels, estimated glomerular filtration rate, a history of hypertension, diabetes mellitus, cerebrovascular accident, smoking history, or chronic obstructive pulmonary disease to exclude the influence of patient demographics, preoperative medical status, and baseline renal function. Multivariate logistic regression analysis was used to evaluate for independent risk factors in the matched sample of 366 patients. The incidence of AKI was 28.6% and 5.9% of patients from the entire sample required renal replacement therapy. AKI was associated with a prolonged postoperative hospital stay and a higher one-month and one-year mortality both in the entire and matched sample set. Independent risk factors for AKI were a left ventricular ejection fraction <55%, preoperative hemoglobin level <10 g/dL, albumin <4.0 g/dL, diagnosis of dissection, operation time >7 hours, deep hypothermic circulatory arrest (DHCA) time >30 min, pRBC transfusion >1000 mL, and FFP transfusion >500 mL. Although the incidence of poor glucose control (blood glucose >180 mg/dL) was higher in patients with AKI in matched sample, it was not an independent risk factor.AKI was still associated with a poor clinical outcome in the matched sample. Potentially modifiable risk factors included preoperative anemia and hypoalbuminemia. Efforts to minimize operation time and DHCA time along with transfusion amount may protect patients undergoing aortic surgery against AKI.

Early prediction of acute kidney injury biomarkers after endovascular stent graft repair of aortic aneurysm: a prospective observational study

BACKGROUND

Acute kidney injury (AKI) is a common and serious condition usually detected some time after onset by changes in serum creatinine (sCr). Although stent grafting to repair aortic aneurysms is associated with AKI caused by surgical procedures or the use of contrast agents, early biomarkers for AKI have not been adequately examined in stent graft recipients. We studied biomarkers including urinary neutrophil gelatinase-associated lipocalin (NGAL), blood NGAL, N-acetyl-β-d-glucosaminidase (NAG), microalbumin (Alb), and liver fatty acid-binding protein (L-FABP) as prospective early biomarkers for AKI in patients who had received stent graft repairs of aortic aneurysms.

METHODS

In addition to pre-surgical sampling, at 2 to 6 h and at 1, 3 to 4, and 5 days or later (until stable) after surgery, urine and serum biomarkers were sampled from 47 patients who underwent stent graft repair of aortic aneurysms.

RESULTS

Using Acute Kidney Injury Network criteria, 6 (14%) of 42 retained patients developed AKI. NGAL corrected with urine Cr (NGAL/Cr) values demonstrated the best predictive value for AKI (97% specificity, 83% sensitivity at a 65.1 μg/gCr cutoff). The area under the receiver-operator characteristic curve of NGAL/Cr value 2 h after surgery was 0.9. Although NGAL/Cr, L-FABP corrected with urine Cr (L-FABP/Cr), L-FABP, NAG, and Alb corrected by urine Cr (Alb/Cr) all reached peak values before AKI detection by sCr in AKI patients, all biomarkers reached the cutoff value before AKI detection after adaption of cutoff value.

CONCLUSIONS

After stent graft repair of aortic aneurysm, NGAL/Cr is a potentially useful early biomarker for AKI.

Acute renal injury after thoracic endovascular aortic repair of Stanford type B aortic dissection: incidence, risk factors, and prognosis

BACKGROUND/PURPOSE

Acute kidney injury (AKI) significantly increases the risk of mortality in patients following cardiovascular intervention procedures. This study was carried out to investigate the incidence, predictors, and prognostic implications of AKI after thoracic endovascular aortic repair (TEVAR) of Stanford type B aortic dissection.

METHODS

A total of 156 patients with Stanford type B aortic dissection who underwent TEVAR were retrospectively analyzed between February 1, 2004 and October 31, 2011. Multivariable regression was used to predict risk factors for AKI. Association between baseline characteristics, postoperative AKI, and mortality during follow up was evaluated.

RESULTS

AKI was identified in 48 (30.8%) of 156 patients, with seven (14.5%) patients requiring continuous renal replacement therapy. The in-hospital mortality rate was 0% in patients without AKI and 12.5% in those with AKI (p = 0.001). Univariate analysis identified preoperative chronic kidney disease, acute dissection, complicated dissection, malperfusion complications with comprehensive complications, and postoperative minimum estimated glomerular filtration rate within 48 hours as associated with AKI. Malperfusion complications [odds ratio (OR) = 4.828; 95% confidence interval (CI) = 1.163-20.03] were the only independent predictor of AKI. Patients suffering from AKI had a 14-fold increased risk for 30-day mortality (OR = 14.3; 95% CI = 1.7-118.4; p = 0.014) and a 10-fold increased risk for 1-year mortality (OR = 9.5; 95% CI = 2.02-44.9; p = 0.004).

CONCLUSION

A significant rate of AKI was observed following TEVAR and was associated with an increase in 30-day and 1-year mortality. Malperfusion complications were identified as an independent predictor of AKI.

The role of mandatory lifelong annual surveillance after thoracic endovascular repair

Thoracic endovascular aortic repair (TEVAR) has become an attractive and well-accepted option for the management of the various thoracic aortic pathologies that vascular surgeons are confronted with. As in the abdominal aorta, current management trends include the treatment of younger patients with longer life expectancies, raising the issue of postoperative surveillance. There are several relevant differences between these anatomic areas when it comes to surveillance, including the relative inaccessibility of the thoracic aorta to ultrasound interrogation and the increased variability of thoracic aortic pathologies and post-TEVAR complications. In addition, concerns regarding radiation-induced carcinogenesis and contrast-induced nephropathy reduce the enthusiasm of many surgeons for regular computed tomography surveillance. Most agree that surveillance is important after TEVAR, but the method, duration, and frequency of that surveillance is much less clear and is the topic of this debate.

Risk factors and impact of proximal fixation on acute and chronic renal dysfunction after endovascular aortic aneurysm repair using glomerular filtration rate criteria

BACKGROUND

The incidence of renal impairment relevant to proximal fixation of aortic endograft devices remains unclear.

METHODS

Retrospective cohort of 208 consecutive patients that underwent EVAR from 2006 to 2011. Estimated glomerular filtration rate (eGFR) was based on MDRD study equation. Acute kidney injury (AKI) and chronic kidney disease (CKD) were classified with ADIQ/RIFLE criteria and National Kidney Foundation criteria, respectively. Kaplan-Meier curve was applied to evaluate progression to CKD. Multivariate regression model was fit to identify predictors for developing AKI and CKD.

RESULTS

Suprarenal fixation group (SF) included 110 patients and infrarenal fixation group (IF) included 98 patients. Both groups had similar demographics, baseline eGFR, and renal-protection protocols. There was a trend for decreased use of contrast in IF group (median: 93.5 vs. 103 cc, P = 0.07). AKI occurred in 15% of patients in SF group and 19% of patients in IF group (RR: 1.24, P = 0.47). The freedom from progression to stage 3 or 4 CKD in the SF group was 0.76, 0.72, and 0.49 at 6, 12, and 18 months, respectively, while for IF group was 0.8, 0.73, and 0.68, respectively (P = 0.4). Increasing age (P = 0.07), lengthy procedures (P < 0.001), and baseline renal dysfunction (P < 0.001) were significant predictors for developing CKD. Contrast volume (P < 0.001) and ace-inhibitors (P = 0.07) were predictors for AKI.

CONCLUSION

Proximal fixation type has no significant effect on both acute and chronic renal function. Identification of modifiable perioperative risk factors may be used to improve renal function outcomes.

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.

Descending thoracic aortic surgery: update on mortality, morbidity, risk assessment and management

PURPOSE OF REVIEW

The purpose of this review is to summarize the literature on thoracic aortic surgery, as well as key management guidelines in the perioperative period. This is particularly timely, as endovascular techniques continue to evolve and become more available.

RECENT FINDINGS

Endovascular treatment of thoracic aortic disease is expanding in applications and case complexity.

SUMMARY

With the expanded use of endovascular techniques to treat aortic disease, midterm and long-term outcome studies and comparisons to open surgical approach are now being published with increasing frequency. This review analyzes the available literature on preventing adverse outcomes after descending thoracic aortic surgery, with specific attention to mortality, morbidity, risk assessment and management in the perioperative setting.

Hyperglycaemia emerging during general anaesthesia induces rat acute kidney injury via impaired microcirculation, augmented apoptosis and inhibited cell proliferation

AIM

Major surgery under general anaesthesia frequently triggers acute kidney injury by yet unknown mechanisms. We investigated the role of anaesthesia-triggered systemic hyperglycaemia in impairment of renal functioning, renal tissue injury, intra-renal Angiotensin-II synthesis and endogenous insulin production in anaesthetized rats.

METHODS

Eighty-eight Sprague-Dawley rats underwent general anaesthesia for 1 h by different anaesthetic compounds. Some of the animals were either injected with high glucose, or received insulin prior to anaesthesia. Blood pressure, renal functioning estimated by cystatin-C and urea, renal perfusion evaluated by laser Doppler technique, blood glucose and insulin were surveyed. Subsequently, rat kidneys were excised, to be used for immunohistochemical examinations or preparation of renal extracts for intra-renal Angiotensin-II measurements.

RESULTS

Elevated blood sugar was observed 5 min following induction of anaesthesia, concurrently with deterioration of renal functioning, drop of systemic blood pressure and decreased renal blood flow. Blood insulin concentrations positively correlated with glucose levels. Intra-renal Angiotensin-II was significantly augmented. Immunohistochemical examinations demonstrated enhanced staining for pro-apoptotic proteins and negligible cell proliferation in tubular tissues. Renal damage resultant from anaesthesia-induced hyperglycaemia could be attenuated by insulin injections. Rats challenged with glucose prior to anaesthesia demonstrated cumulative hyperglycaemia, further increase in insulin secretion, drop of renal blood flow and increased apoptosis. The effects were specific, since they could not be mimicked by replacing glucose with mannose.

CONCLUSION

Anaesthesia-induced hyperglycaemia affects intra-renal auto-regulation via decreased renal perfusion, thus triggering renal function deterioration and tubular injury. Increased intra-renal Angiotensin-II aggravates the damage. Tight hypoglycaemic control might prevent or, at least, attenuate anaesthesia-induced renal injury.

Renal dysfunction and fluid and electrolyte disturbances

PURPOSE OF REVIEW

To examine recent developments in preventing and treating postoperative acute renal dysfunction. To review contemporary issues concerning perioperative fluid and electrolyte management.

RECENT FINDINGS

Renal dysfunction remains a major postoperative morbidity despite the advent of intermittent and continuous renal replacement therapies. It is also associated with increased mortality. Newer techniques, such as off-pump coronary artery bypass surgery, which promised to reduce the incidence of postoperative renal injury, have failed to do so. In addition, newer techniques such as endovascular repair of aortic disorder and the transcutaneous insertion of aortic valves are associated with substantial degrees of kidney injury partially due to the use of much intravenous contrast material. Therefore, the present-day approach to preventing contrast-induced nephropathy is reviewed. Electrolyte disturbances are especially problematic after certain types of surgery, such as trans-sphenoidal adenomectomy and surgeries requiring the use of large volumes of irrigating solutions.

SUMMARY

Renal dysfunction, along with fluid and electrolyte disturbances, is a major issue that needs to be considered as part of perioperative management. Moreover, it is the prevention of clinically significant renal injury and electrolyte disturbances that is the cornerstone of contemporary anesthetic and surgical care.