Endovascular treatment of cerebral aneurysm after renal transplantation in polycystic kidney disease

Abstract

Background

Patients with polycystic kidney disease have a higher prevalence of intracranial aneurysms and may progress to renal failure requiring transplantation. The endovascular treatment of intracranial aneurysms may improve prognosis, since rupture often causes premature death or disability, but the nephrotoxicity risk associated with contrast medium must be always considered in cases of renal impairment.

Methods

A 55-year-old female patient with polycystic kidney disease and grafted kidney associated with anterior communicant artery aneurysm was successfully treated by embolization.

Results

The renal function remained normal after the procedure. To the authors’ knowledge, this is the first case of endovascular treatment of brain aneurysm in a transplanted patient reported in the medical literature.

Conclusions

The endovascular procedure in renal transplant patients is feasible and can be considered to treat this population. Further studies and cases are needed to confirm its safety.

Introduction

Patients with polycystic kidney disease (PKD) have a higher prevalence of intracranial aneurysms and may progress to chronic renal failure requiring transplantation.¹ The progressive increase of kidney transplants has created a group of transplanted patients with normal renal function and pre-existing aneurysms. Nephrotoxicity risk due to contrast medium should always be considered in cases of renal impairment, and may represent a challenge for endovascular treatment. We report a case of aneurysm in a patient with PKD and renal graft transplantation successfully treated by embolization.

Case report

A 55-year-old female patient was diagnosed with PKD at age of 37 years, having a significant family history of PKD: mother, three uncles and five brothers, three died of the disease. Progression to chronic kidney failure required daily peritoneal dialysis during a period of one year and four months, then she underwent kidney transplantation with serum creatinine 11.84 mh/dl and blood urea nitrogen (BUN) 135 mg/dl. Four years later she complained of one-year moderate continuous left hemicranial headache, investigated by her nephrologist with brain magnetic resonance angiography (MRA), which revealed a saccular aneurysm at the anterior communicating artery complex measuring 9 mm (Figure 1). Blood tests showed creatinine 0.67 mh/dl and BUN 23 mg/dl. After multidisciplinary discussion, including nephrology, neurosurgery, and neuroradiology, the risks associated with observation and intervention were clarified to the patient, likewise treatment options including endovascular and microsurgical clipping. She then elected to have embolization by personal choice.

Figure 1.

Magnetic resonance angiography is the initial screening test to diagnose aneurysm in patients with polycystic kidney disease; in this case it showed a saccular aneurysm (arrow) filling by the left anterior cerebral artery (small arrows).

Technical notes

The patient underwent cerebral angiography, using 200 ml of low osmolarity iodinated non-ionic contrast iohexol (Omnipaque, GE Healthcare Inc., Marlborough, Massachusetts, USA). At the same surgical time, under general anesthesia and full anticoagulation, a guiding catheter (Neuron 6F, Penumbra Inc., Alameda, California, USA) was positioned into the distal segment of the left internal carotid artery. A balloon (Hyperform 4 × 7 mm, Medtronic, Irvine, California, USA) was placed into the anterior communicant artery crossing the aneurysm neck, followed by introduction of a microcatheter (Echelon 10, Medtronic) over a microguidewire (Silverspeed 0.010, Medtronic) into the aneurysm. Embolization was performed using detachable coils (Axium, Medtronic), nevertheless, the aneurysm ruptured causing small bleeding, promptly controlled with balloon insufflation, protamine reversal of heparin and coiling, achieving total aneurysm occlusion (Figure 2).

Figure 2.

Angiogram showing (a) saccular aneurysm (arrow) in the anterior communicant complex; (b) it was embolized with coils (arrow) and remodeling balloon (small arrows); (c) a transprocedural rupture occurred (arrows) being controlled through balloon insufflation, protamine reversal of heparin, and coiling; (d) achieving aneurysm occlusion.

Post-procedural evaluation and follow-up

Despite the bleeding, the patient evolved asymptomatic postoperatively, creatinine 0.70 mh/dl and BUN 28 mg/dl. The control computed tomography CT scan on the first postoperative day did not show hemorrhage. Renal function remained normal during hospitalization, with creatinine 0.77 mh/dl and BUN 26 mg/dl on postoperative day 3, when she was discharged.

Discussion

PKD is an autosomal dominant genetic disorder affecting 1:1000 people worldwide.² The prevalence relating cerebral aneurysm to PKD varies in the literature, ranging from 4% to 41.2%.^3–9 In the literature, the prevalence among those with PKD and family history of cerebral aneurysm is also shown, with variation between the studies from 22% to 27.3%.^3–9 The preclinical phase between the formation and development of symptoms/rupture is variable, with the clinical phase between symptoms and subarachnoid hemorrhage/death being short or non-existent.²

Individuals with PKD, particularly those with family history of aneurysm should be screened, preferably before the development of end-stage renal disease.^10,11 MRA and computed angiotomography (CTA) have great accuracy, being recommended to detect intracranial aneurysms.¹¹ MRA is the first choice due to lack of allergen contrast or ionizing radiation and this screening can avoid gadolinium and nephrogenic systemic fibrosis.^2,11 CTA has the disadvantage of similarity of the attenuation coefficients of bone and contrast, interfering with precise lesion delineation between these two interfaces, and should be avoided in patients with renal impairment due to nephrotoxicity risk.¹¹ Digital subtraction angiography (DSA) provides high definition images with temporal resolution and is still the gold standard method to diagnose aneurysms. Nevertheless, DSA has been reserved to therapeutic procedures, considering its invasive nature, possibility of stroke, and high cost.¹¹ Its also requires the use of iodinated contrast media, which is contraindicated in patients with underlying decreased renal function.¹²

The risk of contrast-induced nephropathy (CIN) is increased in patients with diabetes mellitus, impaired renal function, shock, acute injuries, and in the elderly.¹³ One-third of hospitalized patients with acute kidney injury are attributable to CIN. While prophylactic and transprocedural hydration is unequivocal, the use of N-acetylcysteine ​​is not based on strong evidence.¹³ Aminophylline, calcium channel blockers, natriuretic peptide, and diuretics have also not been shown to play a significant role in attenuating the incidence of CIN.¹³ There is clear evidence that CIN does not occur if the patient undergoing contrast examination has normal renal function.¹⁴ The stress with contrast in a transplanted patient with a single kidney definitely affects allograft function, since this solitary kidney has several hemodynamic changes and has been exposed to immunosuppressive agents.¹³ While there is a high incidence of CIN in early transplant recipients, it is low in transplanted patients after 120 days,¹⁵ as in our patient.

The most devastating extrarenal complication or PKD is aneurysm rupture resulting in subarachnoid hemorrhage (SAH), always requiring treatment.¹⁶ Recommendations of therapeutics for unruptured aneurysms include those large, growing, symptomatic, with daughter sacs or located in higher risk locations (posterior communicant artery, posterior circulation), as well as family history of SAH.^11,16 Treatment options include conservative, coiling, and surgical clipping and should be personalized, considering also factors such as age, medical history, and general patient conditions.^1,11,16 Preferably, this is done in a multidisciplinary setting in high-volume vascular centers, with expertise in endovascular treatment and microsurgery.^1,11,16 Coiling is preferable to clipping for aneurysms equal or greater than 10 mm, likewise previous subarachnoid hemorrhage or symptomatic aneurysms.¹⁰ Surgical treatment is associated with longer hospital stays, higher costs, more adverse effects, and in-hospital deaths.¹⁰ In addition to the lack of consensus about treatment of PKD aneurysms, the better option after transplantation, as in our patient, is still unknown. Contrast-less therapeutic alternatives have been published,^12,17 besides endovascular treatment of pseudoaneurysm of the arterial anastomosis in renal transplant,¹⁸ but this is the first case of intracranial aneurysm treated after renal transplantation to the authors’ knowledge. Considering the growing numbers of kidney transplantation cases, the options for treatment in post-transplant PKD need to be better studied.

Conclusions

Endovascular treatment has evolved rapidly, with progressive levels of safety and resolution. Embolization in post-renal transplant patients seems to be safe and represents an alternative to be considered in the therapy of these patients.

Declaration of conflicting interests

The authors declared no potential conflicts of interest with respect to the research, authorship, and/or publication of this article.

Funding

The authors received no financial support for the research, authorship, and/or publication of this article.