Prolonged renal artery occlusion after endovascular aneurysm repair: Endovascular rescue and renal function salvage

Rapid endovascular bailout revascularization of the renal arteries with a steerable guiding sheath after endovascular abdominal aortic aneurysm repair

Advancements in endovascular therapy have made it increasingly available for patients with complex cases but not without complications. Unintentional coverage of the renal arteries is a rare occurrence during endovascular aortic aneurysm repair. Given the potentially devastating repercussions, it is important that surgeons understand the suitability and the risks and benefits of the available revascularization options. We have described two cases of unintentional renal coverage, with subsequent successful bailout via direct manipulation of the stent-graft with a steerable sheath. We also conducted a review of the reported data, discussed the breadth of management options and their technical aspects, and provided several distinct solutions.

T Branch Repair of Ruptured a Type IV Thoracoabdominal Aortic Aneurysm Complicated by Renal Branch Occlusion

A 60-year male patient presented with a thoracoabdominal aortic aneurysm rupture, which was treated emergently with a modified off-the-shelf t-Branch stent-graft (COOK Medical Inc). The sole renal branch occluded 1 month after TEVAR due to branch compression, and the patient became anuric and temporarily dialysis-dependent. Despite the prolonged renal ischemia time, the occluded renal branch was successfully opened with thrombolysis and reinforced with a bare-metal stent. The patient recovered his renal function and came off dialysis.

Renal Function Salvage After Delayed Endovascular Revascularization of Acute Renal Artery Occlusion in Patients With Fenestrated-Branched Endovascular Aneurysm Repair or Visceral Debranching

Purpose: To analyze the renal function and outcome after delayed (>6 hours) endovascular revascularization of acute renal artery occlusion (RAO) in patients with fenestrated-branched endovascular aneurysm repairs (EVARs) or open visceral debranching. Methods: A single-center retrospective analysis was conducted involving 7 patients (mean age 61 years, range 49–72; 5 women) with 9 RAOs treated with endovascular revascularization between December 2014 and March 2017. Three patients had a solitary kidney with chronic renal insufficiency; 1 patient had bilateral occlusions as the acute event. Initial aortic surgery included 5 branched and 1 fenestrated EVAR as well as 1 open visceral debranching operation. Revascularization of the RAO was performed using aspiration thrombectomy, local lysis therapy, and stent-graft relining. The median time between initial aortic surgery and RAO was 10 months (range 0.5–17). Results: Median renal ischemic time to revascularization was 24 hours (range 7–168). Technical success was 100%, with 1 procedure-related access complication. Temporary dialysis dependency occurred in 4 patients. Mean in-hospital stay was 17 days (range 7–32) with 1 postoperative death at day 10 due to cardiac arrest of unknown cause. Mean follow-up was 10.3 months (range 1.5–27) in 5 of 6 discharged patients. During follow-up, 1 reintervention for recurrent occlusion was performed. At follow-up imaging, all renal arteries were patent. No permanent dialysis dependency occurred. Conclusion: Renal function can be salvaged by delayed revascularization for RAO with prolonged renal ischemia. The endovascular approach with aspiration thrombectomy, local lysis, and stent-graft relining is a feasible technique for revascularization after RAO in patients with fenestrated-branched EVAR or open visceral debranching.

Does lower limb exercise worsen renal artery hemodynamics in patients with abdominal aortic aneurysm?

Renal artery stenosis (RAS) and renal complications emerge in some patients after endovascular aneurysm repair (EVAR) to treat abdominal aorta aneurysm (AAA). The mechanisms for the causes of these problems are not clear. We hypothesized that for EVAR patients, lower limb exercise could negatively influence the physiology of the renal artery and the renal function, by decreasing the blood flow velocity and changing the hemodynamics in the renal arteries. To evaluate this hypothesis, pre- and post-operative models of the abdominal aorta were reconstructed based on CT images. The hemodynamic environment was numerically simulated under rest and lower limb exercise conditions. The results revealed that in the renal arteries, lower limb exercise decreased the wall shear stress (WSS), increased the oscillatory shear index (OSI) and increased the relative residence time (RRT). EVAR further enhanced these effects. Because these parameters are related to artery stenosis and atherosclerosis, this preliminary study concluded that lower limb exercise may increase the potential risk of inducing renal artery stenosis and renal complications for AAA patients. This finding could help elucidate the mechanism of renal artery stenosis and renal complications after EVAR and warn us to reconsider the management and nursing care of AAA patients.

Accidental Coverage of Both Renal Arteries during Infrarenal Aortic Stent-Graft Implantation: Cause and Treatment

The purpose of this paper is to report a salvage maneuver for accidental coverage of both renal arteries during endovascular aneurysm repair (EVAR) of an infrarenal abdominal aortic aneurysm (AAA). A 72-year-old female with a 6 cm infrarenal abdominal aortic aneurysm was treated by endovascular means with a standard bifurcated graft. Upon completing an angiogram, both renal arteries were found to be accidentally occluded. Through a left percutaneous brachial approach, the right renal artery was catheterized and a chimney stent was deployed; however this was not possible for the left renal artery. A retroperitoneal surgical approach was therefore carried out with a retrograde chimney stent implanted to restore blood flow. After three months, both renal arteries were patent and renal function was not different from the baseline. Both endovascular with percutaneous access via the brachial artery and open retroperitoneal approaches with retrograde catheterization are feasible rescue techniques to recanalize the accidentally occluded renal arteries during EVAR.

Postoperative "Chimney" for Unintentional Renal Artery Occlusion after EVAR

Renal artery obstruction during endovascular repair of abdominal aortic aneurysm using standard device is a rare but life-threatening complication and should be recognized and repaired rapidly in order to maintain renal function. Both conventional surgery and endovascular stenting have been reported. We report a case of late postoperative bilateral “chimney” to resolve a bilateral thrombosis of the renal artery following an uncomplicated endovascular aortic repair.

Successful reversal of acute kidney failure by ultrasound-accelerated thrombolysis of an occluded renal artery

Purpose. To describe the treatment of renal artery thrombosis with ultrasound-accelerated thrombolysis and discuss the management of prolonged renal ischemia. Case. A 76-year-old patient with a single functional kidney, mild chronic renal impairment, and a recent history of endovascular repair of a thoracoabdominal aneurysm with an aortic branch graft presented with acute flank pain, anuria, and renal failure. The side branch from the aortic stent graft to his single, right, functional kidney appeared to be completely thrombosed. Symptoms had started after cessation of oral anticoagulants because of a planned mastectomy for breast cancer. After identification of the occlusion, ultrasound-accelerated thrombolysis was started 19 hours after the onset of anuria. Angiography, 4 hours after beginning of therapy, already showed partial dissolution of the thrombus and angiographic control after 18 hours showed complete patency of the renal artery side branch. Despite a long period of ischemia, renal function was completely recovered. Conclusion. In patients with acute renal ischemia due to thrombosis of the renal artery, complete recovery of function can be achieved with ultrasound-accelerated thrombolysis, even after prolonged periods of ischemia.

A reversible cause of 'end-stage renal disease': discrepant findings in serial duplex ultrasonograms in a suspected occlusion of a renal arterial bypass graft

Duplex ultrasonography may be inaccurate due to a number of variables in operator and patient characteristics. We describe a 40-year-old woman who presented with acute kidney injury after prior complex abdominal aortic surgery that had left her with an essentially solitary functional kidney. On the basis of normal Doppler findings, she was started on dialysis. Owing to high clinical suspicion and a failure of renal function to return, a second Doppler study was performed 3 weeks after the first, revealing the characteristic tardus-parvus waveform of renal artery stenosis. The patient underwent urgent renal arterial angioplasty and stent placement. She experienced an immediate increase in urinary output, required no further dialysis, and the creatinine improved to 1.7 mg/dL (her prior renal baseline). The case illustrates an important complication of abdominal aortic aneurysm repair, draws attention to a potential source of error in the Doppler measurement, and underscores the limitations of duplex ultrasonography for excluding renal artery stenosis in the presence of high pretest probability.

A case of percutaneous transluminal renal angioplasty for partial coverage of a renal artery by a stent graft after endovascular aneurysm repair

An elderly woman was admitted to our hospital for evaluation of an abdominal aortic aneurysm (AAA) and we decided to treat her AAA with endovascular aneurysm repair. Her renal function became worse after the operation and a renogram suggested flow disturbance of her right renal artery. We performed angiography and checked her right renal artery using intravascular ultrasound. The ultrasound revealed thrombus formation and severe stenosis caused by the stent graft. We performed percutaneous transluminal renal angioplasty at the ostium of her right renal artery. After this procedure, her renal function rapidly improved.

First application of the ‘lasso technique’ on an endograft with suprarenal fixation stent

The authors report the use of the ‘lasso technique’ for the preservation of bilateral renal artery patency, following the intraoperative proximal migration of an aortic endograft with suprarenal bare metal fixation and anchoring barbs, due to device delivery failure.During an emergency endovascular repair of a ruptured mycotic abdominal aortic aneurysm using the Zenith Flex device, the main body of the graft migrated proximally to cover both renal arteries. Attempts to pull down the graft using balloons were not effective.Finally, the ‘lasso technique’ using a guidewire over the aortic bifurcation was employed and successfully adjusted the graft below the level of the renal arteries. No procedure-related complications were noted. The endovascular repair was used as a bridging procedure and two months following the primary endovascular procedure, open surgical repair of the infected aneurysm with excision of the stent graft was performed. The patient is alive after eight months follow-up.

[Treatment of abdominal aortic aneurysms]

The treatment of abdominal aortic aneurysms (AAA) has changed significantly since the introduction of endovascular aortic repair (EVAR). In terms of perioperative morbidity and mortality, randomized multicenter trials revealed results in favour of EVAR compared to open reconstruction. However, EVAR is associated with possible late complications caused by endoleaks, stent migration, kinking and/or overstenting of side branches, making life-long follow-up necessary. Since the majority of patients requiring therapy are elderly and exhibit attendant comorbidities, EVAR has become the procedure of choice in those patients with favourable anatomy. Medicamentous and conservative treatment may be relevant in patients with small to medium-sized aneurysms. Since smoking is one of the major risk factors for the development of AAA, all patients should be advised to stop smoking. Studies on long-term statin therapy in patients following surgical AAA repair showed a reduction in both overall and cardiovascular mortality; AAA patients should therefore receive statins for secondary prevention.

Strategies to tackle unrecognized bilateral renal artery occlusion after endovascular aneurysm repair

BACKGROUND

Unintentional renal artery occlusion after endovascular aortic aneurysm repair (EVAR) is an uncommon phenomenon. The sequelae from this specific complication are severe; consequently, the topic of renal artery coverage is a pertinent issue. We present a case series of patients undergoing EVAR with unintentional renal artery coverage, review the treatment options available, and suggest a treatment algorithm for this scenario based on the evidence.

METHODS AND RESULTS

We report four patients who were found to have renal artery occlusion after EVAR detected up to 5 weeks postoperatively. Renal revascularization was achieved using endovascular renal artery stenting in two patients, and open hepato-spleno-renal bypass in the remaining two cases. Treatment strategies used led to symptom resolution and recovery of renal function in all cases.

CONCLUSIONS

Both open and endovascular techniques may be used as procedures to treat this condition-the choice of procedure is primarily determined by accessibility of the renal orifice.