Intraoperative Factors Affecting Renal Outcome After Open Repair of Suprarenal Aortic Aneurysms

Emergency Repair of a Ruptured Para-Renal Abdominal Aortic Aneurysm in a Patient with a Functional Renal Graft: A Case Report and Review of the Literature

INDRODUCTION

Rupture of and abdominal aortic aneurysm (AAA) in a kidney transplant patient is a rare and rarely reported event. Emergent treatment can be challenging and should achieve effective aortic repair while minimizing ischemic damage to the renal graft during aortic cross-clamping. Several renal protective measures have been proposed such as permanent or temporary shunts, renal cold perfusion and general hypothermia.

CASE REPORT

We report the effective treatment of a para-renal AAA in a patient with a functional renal allograft. A temporary extra-corporeal axillofemoral shunt was constructed to maintain graft's perfusion during open surgical repair. EVAR was not an option due to a short aortic neck. The postoperative period was complicated by colon ischemia and aortic graft infection. At 3 years follow-up the patient was well and graft's function was unchanged.

CONCLUSION

This case is a reminder that renal graft protection must be accounted for when AAA rupture occurs in kidney transplant patients. We reviewed the literature to find previously reported cases and how they were managed.

Cold Renal Perfusion During Simulation of Juxtarenal Aortic Aneurysm Repair Reduces Systemic Oxidative Stress and Sigmoid Damage in Rats

OBJECTIVES

Juxtarenal aortic surgery induces renal ischaemia reperfusion, which contributes to systemic inflammatory tissue injury and remote organ damage. Renal cooling during suprarenal cross clamping has been shown to reduce renal damage. It is hypothesised that renal cooling during suprarenal cross clamping also has systemic effects and could decrease damage to other organs, like the sigmoid colon.

METHODS

Open juxtarenal aortic aneurysm repair was simulated in 28 male Wistar rats with suprarenal cross clamping for 45 min, followed by 20 min of infrarenal aortic clamping. Four groups were created: sham, no, warm (37 °C saline), and cold (4 °C saline) renal perfusion during suprarenal cross clamping. Primary outcomes were renal damage and sigmoid damage. To assess renal damage, procedure completion serum creatinine rises were measured. Peri-operative microcirculatory flow ratios were determined in the sigmoid using laser Doppler flux. Semi-quantitative immunofluorescence microscopy was used to measure alterations in systemic inflammation parameters, including reactive oxygen species (ROS) production in circulating leukocytes and leukocyte infiltration in the sigmoid. Sigmoid damage was assessed using digestive enzyme (intestinal fatty acid binding protein - I-FABP) leakage, a marker of intestinal integrity.

RESULTS

Suprarenal cross clamping caused deterioration of all systemic parameters. Only cold renal perfusion protected against serum creatinine rise: 0.45 mg/dL without renal perfusion, 0.33 mg/dL, and 0.14 mg/dL (p = .009) with warm and cold perfusion, respectively. Microcirculation in the sigmoid was attenuated with warm (p = .002) and cold renal perfusion (p = .002). A smaller increase of ROS production (p = .034) was seen only after cold perfusion, while leukocyte infiltration in the sigmoid colon decreased after warm (p = .006) and cold perfusion (p = .018). Finally, digestive enzyme leakage increased more without (1.5AU) than with warm (1.3AU; p = .007) and cold renal perfusion (1.2AU; p = .002).

CONCLUSIONS

Renal ischaemia/reperfusion injury after suprarenal cross clamping decreased microcirculatory flow, increased systemic ROS production, leukocyte infiltration, and I-FABP leakage in the sigmoid colon. Cold renal perfusion was superior to warm perfusion and reduced renal damage and had beneficial systemic effects, reducing sigmoid damage in this experimental study.

Open aortic repair up to previous abdominal aortic surgery

BACKGROUND

To determine whether direct open repair of thoracoabdominal aortic aneurysms after previous abdominal aortic surgery is a safe option.

METHODS

Ten patients were operated between January 2006 and January 2012. Mean age was 70 years (62-78 years). Four aneurysms (Crawford type III) were treated by firstly performed bypasses from the upper thoracic aorta to the celiac trunk, the superior mesenteric artery, and the left renal artery. Secondly performed aortic repair included revascularization of intercostal arteries identified as critical for spinal cord and the right renal artery. Similarly, the 6 aneurysms (Crawford type IV) were treated by firstly performed bypass from the upper thoracic aorta to the left renal artery before aortic repair.

RESULTS

The overall mortality and paraplegia rates were nil. The maximal creatinin sera variation was 48 ± 16% with return to the baseline level before discharge. Five patients presented with pulmonary complications. The duration of stay was 9.3 days (2-29) in the intensive care unit and 24 days (10-40) in the surgical unit. The mean follow-up was 35 months. No patient died during the follow-up.

CONCLUSIONS

In our experience, open redo aortic surgery appears to be safe. The main relevant point is the sequential reconstruction of the aorta including bypasses of the visceral branches that lowered the visceral ischemic damage because of high level aortic cross-clamping.

Temporary extracorporeal axillo-iliac vascular prosthesis shunt in open repair of a pararenal aortic aneurysm

INTRODUCTION

When a long aortic clamp time is expected or when upper body to lower body collateral arteries are sparse, temporary lower body perfusion may be needed to reduce ischemic injury during supraceliac clamping in open repair of pararenal aortic aneurysms. The use of conventional extracorporeal perfusion techniques carry extra risks and is not in the armamentarium of most vascular surgeons. An axillo-femoral or -iliac shunt using a vascular prosthesis does not require the same degree of anticoagulation and causes less activation of blood components.

PRESENTATION OF CASE

A patient, who had extensive vascular stenotic disease and large bowel ischemia, was operated on for a pararenal aortic aneurysm while the lower body was perfused via a temporary extracorporeal vascular prosthesis axillo-iliac shunt. Copious backbleeding encountered while suturing the proximal anastomosis testified to the efficacy of the temporary shunt. A left hemicolectomy had to be performed for gangrene of the sigmoid colon and he needed 2 days of respiratory support; otherwise the postoperative course was uneventful.

DISCUSSION

In our case more ischemic injury than that observed might have been expected without the temporary bypass but significant backbleeding may have negated some of the beneficial effect of the shunt.

CONCLUSION

A temporary axillo-femoral or -iliac shunt prevents lower limb ischemia and provides an ample amount of collateral blood flow to the torso. It does not need to be buried subcutaneously as previously described. Occlusive balloons should be used where possible to prevent backbleeding and to further increase available collateral blood supply.