Abdominal aortic aneurysms (AAA) with mesenteric artery stenosis or obstructive lesions are occasionally recognized. While performing the graft replacement operation in such cases, if the collateral circulation supplying the gastrointestinal tract is well developed, it is necessary that this collateral circulation should be well perfused during aortic cross-clamping. A 72-year-old woman was admitted because of expansion of AAA. Computed tomography (CT) scan examination revealed occlusion at the origin of the superior mesenteric artery (SMA) and the development of a collateral circulatory pathway via the inferior mesenteric artery (IMA). During this operation, a vein cannula was placed in the IMA, through which blood was supplied with an extension tube for the protection of the intra-abdominal organs. The IMA was reimplanted after the graft replacement. Previous reports indicate that intestinal ischemia may be successfully prevented by supplying blood to the collateral circulation using various techniques. We report the surgical approach for treatment of AAA using a simple and convenient method to maintain intra-operative blood supply to vital organs.
Based on the previous reports, narrowing in the branches of the abdominal aorta ranges between 12.5% and 21% at the celiac artery (CA) and 3.4% and 37% at the SMA [
A 73-year-old woman, previously diagnosed with AAA, was referred because expansion of AAA was detected on follow-up CTscan. She was 160 cm tall and weighed 52 kg, with previous history of hypertension, hepatitis C, and hyperlipidemia. She had no recent weight loss or symptoms of abdominal ischemia. Despite a daily dose of 1800 mg of ethyl icosapentate, her hyperlipidemia was uncontrolled, and she had been a smoker for more than 45 years. Computed tomographic angiography (CTA) revealed occlusion (
She was hospitalized to undergo surgery because the aneurysm had expanded by approximately 4 mm in 6 months.
Chest radiography was unremarkable, and cardiac catheterization revealed
normal coronary arteries. In this patient, there was a high index of suspicion that if abdominal aortic clamping were to be performed in the infra-renal portion of the AAA in the usual manner, there would be a high risk of ischemic injury to the intra-abdominal organs. Therefore, the IMA supplying blood to the developed collateral blood vessels was perfused during the aortic reconstruction, to avoid ischemic injury to the intra-abdominal organs.
General and lumbar anesthesia were used for the operation, which was performed using a midline abdominal incision.
Laparotomy confirmed the presence of an AAA, and a thick IMA appeared meandering. The periphery of the IMA was appropriately peeled off and exposed to enable anastomosis, and the central side of the AAA was exposed and freed from surrounding tissues. After administration of heparin (100 units/kg), an 8-Fr sheath was placed centrally through the neck of the AAA with a vein cannula for the extension tube, and the vein cannula for coronary artery bypass grafting (CABG) was placed inside the vein cannula for the extension tube. The vein cannula for CABG was connected to the IMA and a syringe. We measured the maximum diameter of the vessel in the central part of the AAA to be approximately 18 mm, and a Y-shaped knitted Dacron graft (16 × 8 mm) manufactured by MAQUET was chosen. After completion of the central anastomosis of the AAA, the IMA was anastomosed to the left leg of the Y-shaped knitted Dacron graft using 6-0 prolene RB-1. The vessel was unclamped, and blood flow to the IMA was resumed. Next, the left and right legs of the artificial blood vessel were sequentially anastomosed to the common iliac arteries (CIAs) with 6-0 Prolene. After sufficient de-airing of the artificial blood vessel, we unclamped and restored blood flow to the lower limbs. The procedure was completed after ensuring adequate hemostasis and closure. Duration of intestinal ischemia (time period between the clamping of the aorta and completion of the IMA anastomosis) was approximately 40 minutes. The patient recovered well postoperatively except for the development of systemic eczema that required a brief hospital stay. Postoperative CTA was performed (
She was followed up to 25 months and no further adverse events noticed. CT scan and ultrasound examination showed regular results with a patent IMA branch.
Patients developing ischemic colitis often follow a fatal course [
have been reported wherein blood needed to be delivered to the collateral circulation to prevent ischemic injury to intra-abdominal organs [
Angioplasty was considered risky in the presence of occlusion of the SMA. Having understood the risk and benefits of the procedure, which were explained to her, the patient herself chose to undergo a laparotomy.
The neck of the AAA was noted to be relatively long, IMA of the aorta immediately under the kidney, which is collateral, is reimplanted as the first step, and the AAA operation was then performed. However, there was an arteriosclerotic lesion in the arterial wall, and we did not select it considering the possibility to skip debris by executing side clamp.
Neglen and colleagues [
In this case, though the use of the femoral artery (FA) indwelling kit was simple, and convenient, a disadvantage was that if the 8-Fr sheath is used, it is difficult to maintain the rate of blood flow or sufficient flow pressure. We placed a syringe with a 20- or 30-cc chip on a three-way tube as a stand-by option for pumping blood manually if the infusion to the IMA could not be maintained. We also considered blood infusion into the IMA using a pump for blood transfusion. However, we were able to maintain a good rate of blood flow infusion (about 180 mL/min) and adequate blood pressure throughout the operation, which could be attributed to the shorter length of the circuit compared to a bypass operation using artificial blood vessels.
This simple method could minimize the time required for an anastomosis using artificial blood vessels during an AAA repair procedure.
We propose that this technique of ensuring a transiently sufficient blood flow to the intestinal tract is a minimally invasive method that can be easily performed without involving an elaborate vascular anastomosis surgery. A simple procedure that prevents ischemia of abdominal organs during surgery, it seems to be a feasible option for cases requiring perfusion to the collateral circulation.
The authors declare no conflicts of interest regarding the publication of this paper.
Kobayashi, Y., Yamaguchi, T. and Yoshida, J. (2018) Abdominal Aortic Aneurysm Repair in a Patient with Superior Mesenteric Artery Occlusion with Transient Intraoperative Infusion of the Inferior Mesenteric Artery: A Surgical Case Report. World Journal of Cardiovascular Surgery, 8, 213-218. https://doi.org/10.4236/wjcs.2018.811021