Juxtarenal abdominal aortic aneurysm: combined endovascular and open repair with right iliorenal bypass to create adequate proximal neck

Abstracts

Homem de 78 anos de idade, portador de múltiplas morbidades clínicas deu entrada na emergência com um aneurisma de aorta abdominal justa-renal em condições hemodinâmicas estáveis. A tomografia computadorizada caracterizou aneurisma de 6 cm de diâmetro, e a distância do colo proximal do aneurisma era de 5 mm em relação à artéria renal direita e 28 mm à esquerda. Em virtude das condições clínicas do paciente, optou-se pelo reparo endovascular, mas previamente fez-se uma derivação ilíaco-renal direita com enxerto de politetrafluoretileno, via retroperitoneal para se criar um colo proximal adequado. Após quatro dias, o aneurisma de aorta abdominal foi corrigido colocando-se uma endoprótese Excluder® sem intercorrências. O seguimento pós-operatório evidenciou boa perfusão do rim esquerdo e ausência de migração ou endoleak da endoprótese. Este caso ilustra a combinação de técnicas para tornar possível o reparo de aneurisma de aorta abdominal justa-renal em pacientes de alto risco cirúrgico e anatomia desfavorável.

Aneurisma da aorta abdominal; cirurgia; prótese vascular; endovascular; artéria renal

CASE REPORT

Juxtarenal abdominal aortic aneurysm: combined endovascular and open repair with right iliorenal bypass to create adequate proximal neck

Matheus Bredarioli^I; Marcelo Bellini Dalio^I; Cleber Aparecido Pita Bezerra^II; Carlos Eli Piccinato^III; Jesualdo Cherri^IV

^IVascular surgeons and graduate students, Surgical Clinic, Department of Surgery and Anatomy, Faculdade de Medicina de Ribeirão Preto — Universidade de São Paulo (FMRP-USP), Ribeirão Preto, SP, Brazil

^IIResident, Vascular Surgery, Department of Surgery and Anatomy, FMRP-USP, Ribeirão Preto, SP, Brazil

^IIIProfessor, Vascular Surgery, Department of Surgery and Anatomy, FMRP-USP, Ribeirão Preto, SP, Brazil

^IVAssociate professor, Vascular Surgery, Department of Surgery and Anatomy, FMRP-USP, Ribeirão Preto, SP, Brazil

^{Correspondence}

ABSTRACT

A 78-year-old man with a juxtarenal abdominal aortic aneurysm and several comorbid conditions was admitted at the emergency room in hemodynamically stable conditions. Computed tomography revealed an aneurysm measuring 6 cm in diameter beginning 28 mm below the left renal artery and 5 mm below the right renal artery. Because of the patient's clinical status, a bypass from the right iliac artery to the right renal artery was performed through a retroperitoneal approach using a polytetrafluoroethylene vascular graft. Four days later, an endovascular aneurysm repair was successfully performed using an Excluder^® stent-graft. Postoperative follow-up showed good left renal perfusion and no migration or endoleak. This case illustrates the effectiveness of combining open and endovascular techniques to repair juxtarenal abdominal aortic aneurysm in high-risk patients with unfavorable anatomy.

Keywords: Abdominal aortic aneurysm, surgery, vascular graft, endovascular, renal artery.

Introduction

Nowadays, conventional surgery is still the gold standard for the treatment of abdominal aortic aneurysm (AAA). The advent of endovascular repair (EVAR), however, has brought great benefits to patients with multiple clinical comorbid conditions and high surgical risk, as long as they present compatible anatomy to available grafts.

To guarantee an adequate graft proximal fixation, most manufacturers recommend an infrarenal aortic neck of at least 15 mm. Patients selected according to that recommendation progress with lower migration rates or endoleak.¹ Implantation of grafts in AAA with infrarenal neck lower than 15 mm, despite being successfully described by many authors, is not a consensual procedure.² In selected patients, it is possible to create a favorable proximal neck through surgical revascularization of the renal artery.

This report describes a case of AAA whose endovascular procedure was performed after creation of favorable anatomical conditions by widening the proximal neck length through surgical reallocation of the right renal artery.

Case description

A 78-year-old male patient was admitted to the emergency room complaining of low back pain. Computed tomography (CT) diagnosed lumbar vertebra fracture with the finding of a juxtarenal AAA measuring 6 cm in its largest cross-sectional diameter, with no signs of rupture or dissection. Three-dimensional reconstruction of CT showed that the left renal artery originated 28 mm above the aneurysmal sac, and the right renal artery only at 5 mm (Figure 1). Both kidneys apparently had normal dimensions and symmetrically excreted contrast. The patient's clinical history included diabetes mellitus, hypertension, compensated coronary disease, chronic myeloid leukemia (myelodysplastic syndrome), chronic obstructive pulmonary disease, non-dialytic chronic renal insufficiency (creatinine = 2.5 mg/dL) and obesity (102 kg). The patient was referred to the discipline of Vascular Surgery at FMRP-USP for EVAR planning, since he could not tolerate an aortic clamping using open surgery, due to his clinical conditions. Since he presented a short infrarenal neck at the right side (5 mm), an open approach without aortic clamping before EVAR was performed, with the aim of creating an adequate proximal neck. Using a right retroperitoneal approach, a bypass with 6 mm polytetrafluoroethylene (PTFE) was performed, connecting the external iliac artery (latero-terminal anastomosis) to the right renal artery (termino-terminal anastomosis). The proximal stump of the right renal artery was ligated.

After the procedure, the patient was sent to intensive care unit (ICU). Four days later, EVAR was performed with an Excluder^® graft (W.L. Gore, Inc, Flagstaff, Arizona, USA), using bilateral inguinotomy. Final arteriography showed that the iliac and renal bypass was patent and that the graft was well placed and with noendoleak. There was a slight increase in serum creatinine levels, which returned to values lower than those before the surgery after some days (Cr = 1.5 mg/dL). Due to the patient's clinical conditions and obesity, his recovery was slow and there were complications in the operative wound. In spite of that, he was discharged 12 days after the second procedure. Control CT, performed 1 month later, showed good graft placement and absence of endoleak (Figure 2). Magnetic resonance angiography (MRA), used in the postoperative follow-up after 6 months, revealed that the right iliac and renal bypass was patent and that renal perfusion was normal. There was no endoleak or migration (Figure 3). At the return visit for annual follow-up, the patient was completely recovered from the procedure. His new MRA did not show changes compared with the previous one.

Discussion

The concept of combining open and endovascular repair is not new. In the literature, there are reports describing EVAR associated with visceral revascularization in the treatment of infrarenal³ and suprarenal AAA.^4,5 This technique is based on the theoretical principle of associating the advantages of both repair modalities, thus allowing treatment of high-risk patients, such as the case described herein.

Open repair, which is also the gold standard, requires aortic clamping, which could cause fatal complications in high-risk patients. Parodi et al.⁶ introduced the EVAR technique in the 1980's, whose main advantage was avoiding aortic clamping. However, to release grafts safely and have as few complications as possible, certain anatomical conditions are recommended by manufacturers, including presence of an infrarenal neck of at least 15 mm. With the aim of making EVAR safer in patients with short infrarenal neck, new grafts have been studied and tested.⁷ However, presence of an infrarenal neck of at least 15 mm is still required for most products. Short necks are associated with complications such as migration and type I endoleak .⁸

Our patient had an AAA with 6 cm in diameter, which justified its repair. Suprarenal aortic clamping could not be tolerated due to the patient's multiple comorbid conditions. For that reason, surgical procedure was contraindicated. EVAR alone was not advisable due to inadequate infrarenal neck. The solution was to create an adequate proximal neck using surgical revascularization of the right renal artery with an iliac and renal bypass using PTFE. Occlusion of the right renal artery was not considered, due to renal insufficiency with symmetrical kidneys.

Right retroperitoneal approach was chosen for the bypass procedure because it provides adequate exposure of renal and iliac vessels and avoids manipulation of the bowel. The right external iliac artery was used as donating artery in the bypass to avoid aortic clamping and leave common iliac arteries free for distal graft anchoring. The whole procedure was performed in two separate interventions to avoid additional effects of right renal clamping and infusion of iodinated contrast in a patient with chronic renal insufficiency.

During the first days after the procedure, there were increased creatinine levels in the patient, which were reduced after adequate hydration at the ICU. There were no difficulties during EVAR by presence of gas image in the bowel at fluoroscopy due to adynamic ileus. Despite this difficulty, the graft was well placed without image suggesting endoleak. On the 30th postoperative day, CT revealed good graft placement and absence of endoleak. Six months and 1 year after the procedure, follow-up was performed using MRA, with the aim of avoiding iodinated contrast.

An emergent technology in the treatment of juxtarenal AAA is the use of grafts with branches and fenestrations to the visceral arteries.⁹ There are many reports in the literature describing successful experiences of independent cases using this new technology,^10,11 but long-term follow-up studies are needed to consolidate it.

In summary, this case is an example of how it is possible to combine surgical and endovascular techniques to allow treatment of juxtarenal AAA in high-risk patients for surgery and with unfavorable anatomy. For a successful combination, vascular surgeons should master both techniques.

References

Manuscript received March 8, 2007, accepted May 21, 2007.

This study was carried out for the Discipline of Vascular Surgery of the Department of Surgery and Anatomy at FMRP-USP and presented as poster at VII SOBRICE, held in São Paulo from November 3 to 5, 2005.

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Publication Dates

• Publication in this collection
  20 Sept 2007
• Date of issue
  June 2007

History

• Accepted
  21 May 2007
• Received
  08 Mar 2007