Renal artery aneurism and renal autotransplantation: review of surgical technique, preoperative complementary examinations and postoperative follow-up protocol

Abstract

Introduction: Renal artery aneurysm (RAA) is a rare pathology; however, its incidental diagnosis is increasingly frequent due to the increasing use of imaging techniques. Complex (hilar) RAAs, dependent on the distal renal artery and its branches, constitute a subset of RAAs that present a therapeutic challenge due to their anatomical location and may require extracorporeal arterial repair and autotransplantation. Material and methods: A bibliographic review is carried out to homogenize the management of this pathology, analyzing the indications for surgical treatment, the recommended surgical technique step by step, as well as post-surgical monitoring. Two clinical cases of RAA treated in our center by hand-assisted laparoscopic nephrectomy, ex vivo bench repair and renal autotransplantation are presented. Results: In both cases, a postoperative Doppler ultrasound of the graft was performed 24 hours later, in which a renal graft was observed in the iliac fossa, of normal size and cortical thickness within normality with normal color Doppler signal, and spectral curves without alterations. Both patients presented oligoanuric acute renal failure (injury) during the immediate postoperative period (first 24 hours) with complete resolution at discharge, which occurred on the 11th and 12th postoperative day, respectively. In both patients a diuretic renogram with MAG3 was performed. In case 1, it was performed the third postoperative month and a slightly ectatic right kidney was observed with less perfusion and parenchymal incorporation of the radiotracer, with a reduction in relative renal function (39.47%) and MAG3 clearance (indeterminate renographic pattern). In this patient, a CT scan with the excretory phase was performed simultaneously, in which a grafted right kidney was seen at the level of the right iliac fossa with good contrast elimination in the excretory phase bilaterally and symmetrically. A small non-perfused area is observed in the upper pole. In the second patient, the renogram was performed on the 14th postoperative day, finding the morphofunctional study of the graft within normal parameters without detecting areas of hypoperfusion. The levels of creatinine and glomerular filtration were, respectively, in the first case: 0.86mg/dl and 90.19ml/min/1.73m2 preoperatively and 0.83mg/dl and 90.96ml/min/ 1.73m2 per postoperative month. In the second case, the values were: preoperatively creatinine of 0.66mg/dl and glomerular filtration rate of 97.96ml/min/1.73m2 and 0.81mg/dl and 89ml/min/1.73m2 one month postoperatively. Conclusion: After reviewing the literature, there is no consensus regarding the imaging techniques to be performed after renal autotransplantation and the optimal time frames for performing these for the evaluation of the postoperative graft. There is also no homogeneity in the imaging techniques to be performed in the preoperative assessment. In our experience, open ex vivo surgical repair of complex distal hilar RAAs has been successful with low morbidity and mortality and an acceptable rate of preservation of renal function.