A 30-year-old lady underwent an uncomplicated living related renal transplant in 2006 at the age of 17 years old. She initially presented with uremia and hypertensive urgency. She was diagnosed with End Stage Renal Disease (ESRD) and was subsequently started on hemodialysis in that same admission. She then received a Living Donor Kidney Transplant (LDKT) from her mother 4 months later. Post-transplant, she was asymptomatic, and her estimated glomerular filtration rate (eGFR) was 57ml/min. She was a non-smoker with no other significant past medical history. There was no history of intravenous drug abuse or atherosclerosis of blood vessels.
Clinical Findings
She was on regular follow up and during a routine follow up ultrasound in 2018, we incidentally detected a saccular TRAA (Fig. 1).
She was asymptomatic, and abdominal examination was unremarkable.
Timeline :
A timeline of her clinical course is as follows.
March 2006 – Presented with uremia and hypertensive urgency (ESRD)
July 2006 – LDKT from her mother
2018 – TRAA incidentally detected on Doppler Ultrasound Screening
Diagnostic Assessment:
Doppler ultrasound of the renal vessels yearly is routinely used for follow-up. At the time of transplantation, pre operative imaging did not detect any TRAA in the donor kidney. There were no kidney biopsies performed for cause until TRAA was detected. After suspicion of a TRAA on doppler ultrasound (Fig. 1), a multi-sliced computed tomography angiogram with 3D reconstruction is essential to assess TRAA anatomy and for surgical planning, as seen in our patient (Fig. 2).
Computed Tomography (CT) angiogram with a detailed 3D reconstruction was then done, which showed a 2.6 x 2.2 cm wide neck saccular TRAA arising from the anterior segmental branch of the graft renal artery (Figs. 2 & 3). Intrarenal vasculature was noted to be normal.
Her eGFR was 57ml/min before the repair of the TRAA.
Therapeutic Intervention:
A multidisciplinary meeting was held with a radiologist, vascular surgeon and urologist and discussed treatment options for TRAA including endovascular stenting, percutaneous thrombin injection and surgical repair. Endovascular stenting is often used in renal artery pseudoaneurysm and it requires adequate proximal and distal landing zone [3]. Endovascular approach was excluded due to the short take off of the renal artery and lack of proper landing zone (Fig. 3). With percutaneous approach deemed not feasible, the decision for open surgical approach with in vivo repair was made. Involving a multidisciplinary team is a key step in successful management of TRAA.
During the surgical planning, the saphenous vein was identified as an appropriate conduit. It is a commonly used autologous graft for various vascular reconstruction. Although there are some reports on delayed saphenous vein graft aneurysms[4], the saphenous vein’s caliber, length, ease of exploration and little venous drainage consequences when sacrificed has made it a versatile autologous graft. [4]
A midline laparotomy was performed for direct access to the anteriorly placed aneurysm and iliac vessels. A midline transperitoneal approach provided direct access to the renal transplant graft hilum and TRAA. The Right common iliac artery (CIA) and right external iliac artery (EIA) were isolated for possible emergency clamping. We planned not to mobilize the allograft to reduce risk of injury to the graft.
TRAA was dissected down to the neck and the branches were carefully dissected to gain adequate length (Fig. 4). Renal vein was identified and isolated. Saphenous vein graft was harvested and prepared.
Partial nephrectomy segmental clamping principles were followed to isolate the aneurysm. The proximal end of the anterior segmental artery was ligated and the distal branch of the anterior segmental artery was clamped. The posterior segmental artery and renal vein were left unclamped to ensure perfusion to the remaining kidney. (Fig. 5).
The proximal end of the saphenous vein was anastomosed to the common iliac artery. (Fig. 6)
In-vivo excision of the TRAA was performed.
The saphenous vein graft was trimmed to the desired length, and anastomosed to the distal divided end of the anterior segmental branch of the renal artery. The saphenous vein was thus used as a bypass from the right CIA to the distal end of the anterior segmental branch of the renal artery. (Fig. 7)
Hemostasis was secured followed by careful inspection of the anastomosis before closure.
The total operative time was 148 minutes, with an estimated blood loss of 500 ml. The warm ischemic time of the allograft was 20 minutes.
Follow Up Outcomes:
There was no clinical evidence of a mycotic aneurysm. Grocott methenamine silver stain and Ziehl-Neelsen stain were performed on the aneurysm and both stains were negative for fungal organisms and acid fast bacilli.
Since the repair, there has not been a recurrence. A CT Angiogram 6 months post TRAA Repair as well as the latest Doppler ultrasound in 2021 did not demonstrate new aneurysms.
Her renal function has been stable post TRAA repair. Her latest eGFR and Creatinine levels in 2023 are 54ml/min and 114 µmol/L respectively.
There were no adverse and unanticipated events.