Short-term Arterial Blood Reperfusion of Normothermic Kidney in Renal Artery and Abdominal Aorta Reconstructive Surgery

The Role of Vaccinium Myrtillus in the Prevention of Renal Injury in an Experimental Model of Ruptured Abdominal Aortic Aneurysm

Objective

To examine the biochemical and histopathological renal effects of ischemia/reperfusion (I/R) injury using a ruptured abdominal aortic aneurysm (RAAA) model in rats and to investigate the potential protective effects of whortleberry (Vaccinium myrtillus).

Methods

Thirty-two male Sprague-Dawley rats were randomly assigned into four groups - control, sham (I/R+glycerol), I/R, and I/R+whortleberry. Midline laparotomy alone was performed in the control group. Atraumatic abdominal clamps were attached under anesthesia to the abdominal aorta beneath the level of the renal artery in the groups subjected to I/R. Sixty-minute reperfusion was established one hour after ischemia. The sham group received five intraperitoneal doses of glycerol five days before I/R. The I/R+whortleberry group received a single intraperitoneal 50 mg/kg dose diluted with saline solution five days before I/R. All animals were finally euthanized by cervical dislocation following 60-min reperfusion.

Results

Increases were observed in malondialdehyde (MDA) levels and tubular necrosis scores (TNS) in thin kidney tissues and in numbers of apoptotic renal tubule cells, together with a decrease in glutathione (GSH) levels, in sham and I/R groups. In contrast, we observed a decrease in MDA levels, TNS, and numbers of apoptotic renal tubule cells, and an increase in GSH levels with whortleberry treatment compared to the I/R group.

Conclusion

Our findings suggest that whortleberry may be effective against acute kidney injury by reducing oxidative stress and apoptosis.

In Situ Treatment of Branch Renal Artery Aneurysms With Pantaloon Vein Graft

Introduction:

The optimal method of operative management of complex renal artery aneurysms (RAAs) involving distal branches (BRAAs) remains unclear. When more than 1 artery is involved within the BRAA, endovascular techniques are not advisable and an ex vivo approach is often preferred. In this study, we introduce an alternative surgical in situ technique to treat BRAAs.

Methods and Surgical Technique:

Five aneurysms involving the main or second-order bifurcation of the renal artery (RA) were treated in 4 patients at our institute between November 2012 and January 2017. The treatment of the BRAAs was based on resection of the aneurysm wall and reconstruction with autologous Pantaloon vein graft (PVG): a “Y-shaped” bypass created on-bench with autogenous great saphenous vein. Sequential clamping/reperfusion of the kidney allows to reduce renal function impairment.

Results:

No perioperative mortality or morbidity was observed, including none nephrectomy. In all the cases, aneurysms were treated with an in situ technique as previously planned. All the grafts were patent at the follow-up time (mean 64.1 ± 11.7 months). Renal function was preserved in all the cases. Vascularization of the renal parenchyma was satisfactory both on arterial echo Doppler and contrast-medium ultrasound in all the cases. Average cross-clamping times of the main RA and of a single branch RA were 15.8 ± 1.7 and 17.7 ± 4.6 minutes, respectively. Mean total operating time was 266.3 ± 18.9 minutes.

Conclusion:

The PVG with sequential clamping applied in the surgical treatment of BRAAs permits to reduce the ischemic effects to the renal parenchyma. To our knowledge, these are the first cases described in which BRAAs are treated with a PVG and our experience suggests that it is a feasible technique, with good long-term results and without severe adverse events recorded.

Effects of intrarenal administration of the cox-2 inhibitor parecoxib during porcine suprarenal aortic cross-clamping

The aim of this study was to investigate the effects of intrarenal administration of the cyclooxygenase-2 inhibitor parecoxib during suprarenal aortic cross-clamping. In a prospective, controlled, blinded, randomized manner, 16 anesthetized and mechanically ventilated pigs were instrumented to measure systemic and right kidney hemodynamics, oxygen exchange, and metabolism. During 45 min of suprarenal aortic cross-clamping, animals received 40 mg of parecoxib (n = 8) or vehicle (n = 8) infused continuously into the right renal artery. Hemodynamic and metabolic data, right kidney venous blood, as well as urine samples were obtained before clamping, as well as before and 75 and 195 min after declamping. Clamping transiently increased mean arterial pressure in both groups. Systemic and renal blood flow did not differ between the pre- and postclamping measurements or between groups. Parecoxib attenuated the otherwise significant fall in right kidney creatinine clearance (controls: from 45 [7;111] to 17 [9;22] mL/min; parecoxib: from 39 [3;59] to 27 [11;45] mL/min, P = 0.039 and P = 0.297, respectively versus before clamping, P = 0.021 versus controls at 195 min) and prevented the impairment of renal lactate balance observed in the control group (controls: from 0.5 [-0.8;3.5] to 0.2 [-0.2;0.6] mumol/kg/min; parecoxib: from 0.6 [-1.0;2.0] to 0.4 [-1.2;0.6] mumol/kg/min, P = 0.038 and P = 0.285, respectively, versus before clamping). In conclusion, intrarenal parecoxib infusion beneficially influenced kidney function in this clinically relevant model of suprarenal aortic cross-clamping.

Renal dysfunction after vascular surgery

PURPOSE OF REVIEW

The purpose of this review is to focus on the static incidence of renal dysfunction, the lack of evidence of benefit of traditional renoprotective strategies, and newer techniques that may provide an insight into the mechanisms of acute perioperative renal injury associated with vascular surgery.

RECENT FINDINGS

Recent studies that have investigated the long-term results of aortic surgery still report a significant incidence of postoperative renal dysfunction. This finding remains consistent in several reports. However, less invasive techniques such as endovascular repair seem to be associated with reduced inflammation and postoperative renal dysfunction. The possible association between genetic heterogeneity and renal dysfunction in vascular surgical patients is an exciting new area of research.

SUMMARY

Renal dysfunction after major vascular surgery remains a significant problem. New insights into the mechanisms of acute renal injury and less invasive techniques of vascular repair may help reduce the incidence of renal dysfunction in this patient population. The lack of a truly 'renoprotective' agent has hampered our efforts in preventing this major complication of vascular surgery.