Pseudoaneurysm after arterial reconstruction in kidney transplant nephrectomy: A case report and literature review

Background Pseudoaneurysm formation sometimes complicates transplant nephrectomy. We report a case of bleeding from a pseudoaneurysm after transplantation nephrectomy that resulted in shock and emergency endovascular treatment. Case presentation A 56‐year‐old man underwent transplant nephrectomy 3 years and 9 months following transplantation for pyelonephritis‐related infection control. On postoperative day 7, he developed sudden pain in the lower abdomen and subsequently went into shock. A pseudoaneurysm at the anastomosis was detected, and urgent endovascular treatment was performed to stem the bleeding. Conclusion Vascular complications, including pseudoaneurysms, following transplant nephrectomy can be life‐threatening, and comprehensive awareness is needed in careful postoperative management.


Introduction
TN is commonly performed in patients with dysfunctional TKs with infection, pain, bleeding, graft malignancy, or anemia associated with inflammation.TN is sometimes complicated with life-threatening pseudoaneurysms.2][3] Here, we describe a patient who had a good immediate post-TN course but who developed bleeding from a pseudoaneurysm when abdominal pressure was applied, resulting in shock and emergency endovascular treatment.

Case presentation
A 52-year-old man who had undergone regular hemodialysis for 12 months for kidney failure secondary to ADPKD underwent ABO blood type-incompatible living KT.The donor's three renal arteries were reconstructed to form two arteries, which were anastomosed with the recipient's EIA (Fig. 1a).Post-KT, renal function did not improve, and a TK biopsy indicated acute tubular necrosis.Additional immunosuppressive drugs were administered, with minimal improvement.One month later, a nephrostomy tube was placed at the TK for stenosis at the uretero-bladder anastomosis.At 10 months post-KT, he developed recurrent pyelonephritis and was treated with antibiotics, but carbapenem-resistant bacteria appeared among the causative organisms, and infection control was challenging.His kidney function continued to gradually deteriorate, and he was reintroduced to dialysis 17 months after KT.TN was performed 3 years and 9 months after KT because the patient requested retransplantation, and infection control was a priority.During surgery, the arteries around the transplanted kidney were resected as they appeared vulnerable owing to the effects of infection.The EIA was terminally anastomosed using a noninfected artery (Fig. 1b-d).The central and distal sides of the EIA were sufficiently peeled off to perform tension-free anastomoses.The patient was placed on bed rest until postoperative day 4 because of the high risk of postoperative VC.On postoperative day 7, when abdominal pressure was applied to defecate, the patient became aware of severe pain in the lower abdomen and subsequently went into shock.Emergency CT revealed a pseudoaneurysm at the anastomosis site and bleeding from the abdominal cavity into the pelvic cavity (Fig. 2a,b).Emergency endovascular treatment was performed, and the pseudoaneurysm disappeared after stenting (Fig. 2c,d).Postoperatively, red blood cell transfusion was performed until the hemoglobin levels stabilized.He was discharged 23 days after resection following CT confirmation that the hematoma had diminished in size and that there was no further source of infection.At 12 months post-TN, our patient continued to progress without anemia or infection and was being prepared for re-transplantation.

Discussion
The British Transplantation Society reported indications for TN in 2014, and TN is used in many centers, 4 with decisions on whether to perform TN based on perceived benefits and risks.The indications, advantages, and disadvantages of TN are listed in Table 1. 5,6N-related complications such as bleeding, hematoma, and infection have been reported, with incidence rates ranging from 5% to 48%. 7 The incidence of VC has been reported to be 5.6%, with most reported cases being life-threatening. 1 Risk factors include infection of the anastomotic site, 1 with the risk reported to be higher when TN is performed following 12 months of dialysis resumption. 2 Chronic rejection may also be a risk factor for pseudoaneurysm.3 For our patient, underlying disease was also a risk factor for pseudoaneurysm, and patients with ADPKD are known to be prone to pseudoaneurysm during other common surgical procedures.[8][9][10] Table 2 lists the relevant studies identified following a PubMed search relating to VC after TN.Pseudoaneurysms are common in VC, and the risk of mortality is high. Pophylactic methods for VC include immediate vascular reconstruction through bypassing artificial vessels or the saphenous vein at the time of TN, whereas non-immediate vascular reconstruction involves ligation of the EIA, followed by antibiotic treatment and two-phase bypass surgery. 1 Eng et al. reported on two patients for whom artificial vessels or saphenous veins were used during TN.However, one patient died of MRSA wound infection and the other patient had a severe hemorrhage stemming from the site of the vein graft owing to MRSA infection.1 Immediate vascular reconstruction is associated with VCs in cases where reconstruction occurs in the presence of local infection.Non-immediate vascular reconstruction is performed when local infection has resolved; therefore, VCs are unlikely to occur.According to this report, ligation of the EIA without reconstruction at the time of TN is not uniformly associated with limb ischemia. 1f the ipsilateral lower limb is deemed critically ischemic preoperatively, an extra-anatomical bypass, such as a femoralfemoral bypass graft employing antibiotics, is the preferred reconstruction method.However, this report appears not to have been updated as a search of more recent literature did not identify any reports on ligation of the EIA. Lgation of  the EIA was not a treatment option at our hospital because of the risk of lower limb ischemia.In addition, care must be taken postoperatively as bleeding can occur a week after surgery, as in this case.A sufficient period of postoperative rest and thorough evaluation using imaging studies are necessary before discharge from the hospital.

Fig. 1
Fig. 1 Illustration of operation techniques.(a) The transplanted kidney had three renal arteries, and the upper pole renal artery was short.The internal iliac artery was harvested as a graft and anastomosed end-to-end to the upper pole renal artery.Two main arteries were anastomosed and conjoined side-to-side. (b) The TK artery was very fragile and had severe adhesions to the surrounding area due to infection.Vascular suturing after severing the TK artery was extremely challenging.(c) The vessels were resected because the risk of VCs was high as the vessels had become fragile due to infection or other factors.(d) The uninfected EIA was used because of insufficient vessel length.

Fig. 2
Fig. 2 Contrast test to identify the bleeding site.(a) CT showing a pseudoaneurysm at the anastomosis of the EIA (b) The contrast material is also exposed to the abdominal cavity (c) Angiography showing the pseudoaneurysm (d) Covered stent placement (thickness, 8 mm; length, 10 cm).

Table 1
Indications, advantages, and disadvantages of TN Advantage DisadvantageLocalizing symptoms (pain, infection, bleeding) that are resistant to medical therapy in a failed graft Reduction in chronic rejection Decreased GSR

Table 2
Indications, advantages and disadvantages of TN