Adjunctive renal artery revascularization during juxtarenal and suprarenal abdominal aortic aneurysm repairs

Effects of Transfusion of Stored Red Blood Cells on Renal Ischemia-Reperfusion–Induced Hepatic Injury in Rats

BACKGROUND

Renal ischemia-reperfusion (IR) injures the liver as well as the kidneys. Transfusion of stored red blood cells (RBCs) triggers inflammatory responses, oxidative stress, and activation of innate immunity. In the present study, we investigated the effect of transfusion of stored RBCs on renal IR-induced hepatic injury.

METHODS

Sprague-Dawley rats were randomly divided into 3 groups based on the following treatments: rats subjected to sham operation (sham group), rats subjected to the induction of renal IR only (RIR group), and rats transfused with stored RBCs 1 hour after the start of reperfusion (RIR-TF group). Renal ischemia was induced for 1 hour, and reperfusion was allowed for 24 hours. After reperfusion, blood and liver tissue samples were obtained.

RESULTS

Serum levels of aspartate and alanine aminotransferase were increased in the RIR-TF group compared with those in the RIR and sham groups. The hepatic mRNA expression levels of heme oxygenase-1 and neutrophil gelatinase-associated lipocalin were increased in the RIR-TF group compared with those in the RIR and sham groups. The mRNA expression level of high mobility group box-1 was also increased in the RIR-TF group compared with that in the RIR group.

CONCLUSION

The transfusion of stored RBCs exacerbates renal IR-induced liver damage. Oxidative stress may be responsible for hepatic injury.

Is Mini-Invasive Surgery an Alternative for the Treatment of Juxtarenal Aortic Aneurysms?

INTRODUCTION

Aim of our study is to evaluate the outcomes of mini-laparotomy, suprarenal cross-clamping, and enhanced recovery after elective open surgical repair for juxta-renal abdominal aortic aneurysms (JAAA) in a tertiary referral center.

METHODS

Data of all consecutive patients with abdominal aortic aneurysms (AAA) electively treated with left sub-costal mini-laparotomy requiring infrarenal or suprarenal cross-clamping between 2013 and 2018 were retrospectively collected. Patients were divided into two groups: infra-renal cross-clamping (group A) and JAAA requiring supra-renal cross-clamping (group B). Early and mid-term mortality, postoperative renal dysfunction according to RIFLE criteria and factors affecting postoperative outcome were analysed.

RESULTS

Four hundred one patients, 356 (88.8%) men, mean age 70.8 yrs, underwent open surgical repair (OSR), 343 (85.5%) AAA in group A, 58 (14.5%) JAAA in group B. Mean diameter of the aneurysms was 54 ± 11.4 mm vs. 52 ± 9 mm and mean time of intervention 154.9 ± 56.3 min vs. 180.1 ± 65.7 min respectively. Total clamp time was 72.27 ± 31.4 vs. 75 ± 33.1 and suprarenal clamp time in group B 27.82 ± 14.1 min. Mean hospital length of stay was 5.1 ± 2.8 vs. 5.37 ± 3.4 days respectively. At 30 days, 3 (0.9%) patients died in group A and no one in group B; at 24 months 7 (2%) deaths in group A and 4 (6.9%) in group B. Preoperative, postoperative and discharge serum creatinine mean value, in group B, were 1.07 ± 0.32, 1.31 ± 0.36 and 1.83 ± 1.24 respectively. Based on RIFLE criteria for renal function, we observed Risk in 14.2% and Injury in 12.7% of patients after suprarenal cross clamping.

CONCLUSIONS

Our results show that mini-invasive open repair for JAAA with a suprarenal cross-clamping can be performed with acceptable morbidity and mortality rates similar to traditional surgical approach without significant modifications of renal functions.

Development of a Magnetic Kissing Guidewire and Animal Experiment: a Preliminary Study

Endovascular therapy has been the first option for many vascular diseases. Due to the increasing development of endovascular devices and techniques in recent decades, endovascular procedures could be applied in treating those cases with complex anatomy. Two or three vascular access routes are required to establish through-and-through access in endovascular therapy for arterial occlusive disease and complex aortic aneurysm. Guidewire snaring with a snare kit is essential but sometimes time-consuming in the establishment of through-and-through access. To simplify the procedure, we design the magnetic kissing guidewire (MKG) with a magnetic tip that attracts each other to establish a guidewire route that meets the needs of clinical practice. We conducted the in vitro test to evaluate its magnetic force and the in vivo test to assess its performance in the arteries of twelve sheep. The results revealed that this novel guidewire significantly simplified the establishment of through-and-through access.

The Effect of Nitric Oxide on Remote Ischemic Preconditioning in Renal Ischemia Reperfusion Injury in Rats

Although remote ischemic preconditioning (RIPC) is an organ-protective maneuver from subsequent ischemia reperfusion injury (IRI) by application of brief ischemia and reperfusion to other organs, its mechanism remains unclear. However, it is known that RIPC reduces the heart, brain, and liver IRI, and that nitric oxide (NO) is involved in the mechanism of this effect. To identify the role of NO in the protective effect of RIPC in renal IRI, this study examined renal function, oxidative status, and histopathological changes using N-nitro-L-arginine methyl ester (L-NAME), an NO synthase inhibitor. Remote ischemic preconditioning was produced by 3 cycles of 5 minutes ischemia and 5 minutes reperfusion. Blood urea nitrogen, creatinine (Cr), and renal tissue malondialdehyde levels were lower, histopathological damage was less severe, and superoxide dismutase level was higher in the RIPC + IRI group than in the IRI group. The renoprotective effect was reversed by L-NAME. Obtained results suggest that RIPC before renal IRI contributes to improvement of renal function, increases antioxidative marker levels, and decreases oxidative stress marker levels and histopathological damage. Moreover, NO is likely to play an important role in this protective effect of RIPC on renal IRI.

Effects of Allopurinol and Apocynin on Renal Ischemia-Reperfusion Injury in Rats

BACKGROUND

This study evaluated the effects of allopurinol (ALP), a xanthine oxidase inhibitor, and apocynin (APC), a NADPH oxidase inhibitor, administered alone or together, on kidney damage caused by renal ischemia-reperfusion (IR) in rats.

METHODS

Thirty rats were randomly assigned to 5 groups. Group 1 was a sham group. Group 2 was the renal IR control group (30-min ischemia followed by 24-h reperfusion). In groups 3 and 4, ALP or APC, respectively, was administered 1 h before the ischemia. In group 5, ALP and APC were co-administered. Blood urea nitrogen (BUN) and serum creatinine (Cr), renal tissue malondialdehyde (MDA) and superoxide dismutase (SOD), and histological changes were evaluated.

RESULTS

A significant increase in BUN and Cr level, and histological damage was seen in the IR control group, indicating renal injury. Elevated MDA and decreased SOD levels in the IR control group demonstrated that renal damage occurred through oxidative stress. Pretreatment with ALP or APC alone or together prevented IR-induced renal damage. However, there was no significant difference between treatment with a single drug and co-administration of ALP and APC.

CONCLUSIONS

The use of ALP and/or APC before ischemia may be beneficial to ameliorate renal IR injury.

Protective effects of tirofiban on ischemia/reperfusion-induced renal injury in vivo and in vitro

Tirofiban, a glycoprotein IIb/IIIa receptor inhibitor, is widely used in the management of patients with unstable angina or myocardial infarction, and shows protective effects on ischemia/reperfusion (I/R) injured heart. Whether or not it has protective effect on I/R injured kidney is not known. The present in vivo and in vitro study found that serum creatinine (SCR) and blood urea nitrogen (BUN) were significantly increased in I/R rats, accompanied by histopathological damage of the kidney. Apoptotic cells, leukocyte infiltration and ROS production were increased in I/R rats. Pretreatment by intravenous injection of tirofiban (200μg/kg) reduced SCR and BUN levels, ameliorated renal histopathological changes, and decreased ROS production, cell apoptosis and leukocyte infiltration in I/R injured kidney. Our further study showed that the protection of tirofiban might be associated with the restoration of eNOS/iNOS balance, since inhibition of NO production blocked the tirofiban-mediated renal protection on I/R injury. The present in vivo and in vitro study indicated that tirofiban pretreatment exerts a protective effect on I/R injury in kidney through regulation of eNOS/iNOS balance.

Protective effects of aliskiren on ischemia-reperfusion-induced renal injury in rats

The protective effect of aliskiren on ischemia-reperfusion (I/R) injury in the heart and brain has been reported. Whether or not this protective effect extends into the alleviation of renal I/R injury is not known. Therefore, we investigated the protective effect of aliskiren in the kidney in this study. Sprague-Dawley rats were randomly divided into four groups: sham control group; sham control with aliskiren pretreatment; I/R group and I/R with aliskiren pretreatment. Aliskiren (3mg/kg) or vehicle was administrated intravenously via vena cava. Blood samples and the left kidneys were then collected to check for renal function, angiotensin II (Ang II), apoptosis and oxidative stress levels. Compared with the sham rats, serum creatinine (SCR) and blood urea nitrogen (BUN) were significantly increased in the I/R rats, accompanied by histopathological damage to the kidney, which included tubular cell swelling, desquamation, and cast formation. There were also more apoptotic cells and leukocyte infiltration in the I/R rats than in the sham rats. Pretreatment with aliskiren ameliorated I/R induced renal injury, i.e. reduced SCR and BUN levels, ameliorated renal histopathological changes, and decreased the apoptosis of cells and leukocyte infiltration in kidney. I/R injury also decreased superoxide dismutase (SOD) and glutathione (GSH-reduced form) levels, which were blocked with the aliskiren pretreatment. Aliskiren pretreatment exerts a protective effect on ischemia/reperfusion injury in the kidney, via amelioration of oxidative stress, and reduction in leukocyte infiltration and cellular apoptosis.

The protective effects of apocynin on kidney damage caused by renal ischemia/reperfusion

PURPOSE

This experimental study was designed to explore the protective effect of apocynin, the NADPH-oxidase inhibitor, on kidney damage induced by ischemia/reperfusion (I/R) in a rat model.

METHODS

Thirty-two rats were randomly divided into a control group and three I/R groups (1-hour ischemia followed by 23-hour reperfusion). Three I/R groups were treated by apocynin (20 mg/kg, i.p.) at two different time points (before ischemia and during ischemia). The histopathological findings, including apoptotic changes, and also tissue malondialdehyde (MDA), superoxide dismutase (SOD), catalase (CAT), glutathion peroxidase (GPX), reduced glutathione (GSH), myeloperoxidase (MPO), blood urea nitrogen (BUN), and serum creatinine (Cr) levels, were determined.

RESULTS

Kidney tissue MDA and MPO, and serum BUN and Cr levels were found to be significantly higher in the I/R group, but there was no statistically significant difference in the levels of SOD, CAT, GPX, and GSH between the I/R and the control groups. Although apocynin significantly reduced MDA and MPO in group 3 and increased GPX in both treatment groups when compared to the I/R group, the elevated BUN and Cr levels were significantly reduced in treatment groups. Renal I/R injury also induced extensive tubular necrosis, glomerular damage, and apoptosis in the histological evaluation. Apocynin, especially when used during ischemia, ameliorated these histological damages in different amounts in treatment groups.

CONCLUSION

The beneficial effects of apocynin on renal I/R injury were evaluated for the first time.

Comparable mortality with open repair of complex and infrarenal aortic aneurysm

BACKGROUND

A consequence of endovascular aneurysm repair (EVAR) of anatomically straightforward infrarenal abdominal aortic aneurysm repair cohort (AAA) is that open aneurysm repair is more commonly performed for complex anatomy. Complex aneurysm repair with visceral vessel involvement (CAA) or combined aneurysm repair and visceral vessel reconstruction (VVR) has traditionally been considered to increase morbidity and mortality compared with repair of infrarenal AAA. This study evaluated contemporary outcomes of open abdominal aneurysm surgery, including AAA, CAA, and VVR using the National Surgical Quality Improvement Program (NSQIP) database.

METHODS

The NSQIP Participant Use File was queried by CPT code to identify patients undergoing AAA, CAA, and VVR (2005-2008). Comparative analysis of clinical features, technical details and 30-day outcomes was performed using univariate methods. Logistic regression analysis was used to identify predictors of morbidity and mortality.

RESULTS

A total of 2820 patients underwent AAA and 592 CAA. Renal insufficiency (ie, creatinine >1.4 mg/dL) rates were similar in AAA and CAA patients, however, more frequent in patients with VVR (51% vs 31% [no bypass]; P < .01). CAA was less likely to be performed urgently (6.3% vs 9.1%; P < .05) and was associated with increased operative time (254 ± 100 vs 224 ± 93; P < .01) compared with AAA. Univariate analysis showed that CAA did not increase mortality (5.7% vs 5.1%; P = .5). CAA slightly increased overall complications (32% vs 27%; P = .01) compared with AAA. 73 (2.5%) AAA and 84 (12%) CAA patients had simultaneous VVR and these patients exhibited a trend toward increased mortality (8.9% vs 5.2%; P = .07). VVR increased complications (43% (VVR) vs 26% [no bypass]; P < .01), including ventilation >48 hours (21% [VVR] vs 12% [no bypass]; P < .01), renal failure (7.6% [VVR] vs 4.1% [no bypass]; P = .04), and sepsis (13% [VVR] vs 6.3% ([no bypass]; P < .01). Multivariate analysis demonstrated that CAA (odds ratio [OR], 1.3 [95% confidence interval (CI), 1.1-1.6]; P = .01) and VVR (OR, 2.2 [95% CI, 1.8-3.6]; P < .01) increased the odds of any complication. Independent predictors of mortality included dependent functional status (OR, 3.6 [95% CI, 2.3-5.4]; P < .01), elevated pre-op creatinine (OR, 2.9 [95% CI, 2.2-4.0]; P < .01), type II diabetes (OR, 1.6 [95% CI, 1.05-2.4]; P = .03), and age (OR, 1.06 [95% CI, 1.03-1.08]; P < .01). Neither CAA (OR, 1.2 [95% CI, 0.84-1.8]; P = .3) nor VVR (OR, 1.6 [95% CI, 0.89-2.9]; P = .11) were associated with increased mortality compared with AAA.

CONCLUSION

In contemporary practice the migration of open repair to increasingly complex cases has been achieved with 30-day mortality essentially equivalent to open repair of infrarenal AAA. Patients who require VVR do sustain increased complications, in particular renal failure. These data also emphasize the importance of baseline renal insufficiency in clinical decision making. CAA and VVR are associated with increased morbidity in comparison to AAA repair; however, both procedures can be safely performed in patients without increased risk of operative mortality.