案例報告: 在達文西部分腎臟切除7個月後，似腎臟腫瘤復發的假性腎動脈瘤

葉星佐、羅浩倫

高雄長庚紀念醫院泌尿科

Case Report: Renal artery pseodoaneurysm resembling renal tumor recurrence 7 months after robotic assisted partial nephrectomy

Hsing-Tsuo, Yeh, Hao-Lun Luo

Kaohsiung Chang Gung Memorial Hospital, Department of Urology

Introduction: A renal artery pseudoaneurysm is a rare complication of percutaneous renal procedures, renal trauma, or partial nephrectomy. Studies suggests that most cases present within 15 days post operatively with classic symptoms of: gross hematuria, flank pain, and anemia. However, there are a limited number of reports in the literature regarding delayed renal artery pseudoaneurysm (≥4 months). Here, we present a case who was thought to have renal cell carcinoma recurrence after 7 months of image follow up, but then turned out to be a renal artery pseudoaneurysm after biopsy.

Case Report:  This 58-year-old man has underlying disease of left renal papillary renal cell carcinoma, pT1b with suspicious left periaortic lymph nodes metastasis, status post robot-assisted laparoscopic partial left nephrectomy on 2023/07/25, nephrolithiasis, hypertension, diabetes mellitus, chronic kidney disease stage V, and history of laparascopic cholecystectomy. He had received adjuvant radiotherapy and 10 courses of Cabozantinib + Nivolumab, and was under regular outpatient department follow up with only symptoms of adverse effect from tyrosine kinase inhibitor and immunotherapy, such as amylase elevation and diarrhea.

After 7 months of follow up, CT of abdomen without enhancement showed increased size of the mass-like lesion in the left lower kidney (62mm). Contrast agent wasn’t given for his poor renal function, but recurrence of renal cell carcinoma was highly suspected. Physical exams were unremarkable. Blood tests reported chronic anemia (Hb 9.5 g/dL) and chronic kidney disease (Creatinine 5.28 mg/dL). After discussing with patient and family, they agreed on CT-guided biopsy for tissue proof.

CT-guided biopsy was arranged on the second day of admission. Thin-section CT localization for access route avoiding vital or vascular structures were taken. After insertion of coaxial needle (17G) to the lesion, pulsatile bleeding from needle was noted. Thus, immediate transcatheter arterial embolization (TAE) was discussed and arranged under stable vital signs. Contrast medium injection via the coaxial needle confirmed pseudoaneurysm formation. Gelform cube embolization was performed first but in vain. After selective catheterization of the pseudoaneurysm supplying branches from left renal artery, TAE was performed until optimal decreasing blood flow. Patient tolerated the procedure well, and was soon discharged from ward few days after without further events. During next 6 months of image follow up, no local recurrence or metastasis was noted.

Discussion: Renal artery pseudoaneurysm is a potentially life threatening complication after partial nephrectomy. Its etiology is thought to be due to partially transected artery during tumor resection that bleeds into a contained hematoma cavity, particularly near the apex of wedge resection or due to a false puncture made into a vessel during tumor bed closure with the need for needle redirection.

    The typical clinical presentation is usually with acute bleeding episode, but patient’s symptoms can vary from flank pain to acute shock to asymptomatic. It can occur within the early postoperative period, but delayed presentation beyond 7 days after surgery is frequently observed as well. There are a limited number of reports in the literature regarding delayed renal artery pseudoaneurysm (2–4 months).

    Angiography ± embolization is the gold standard diagnostic and therapeutic procedure, and some were diagnosed with contrast-enhanced CT scan, Ultrasound, or MRI. Selective embolization is the most common and preferable approach to preserve renal function while achieving symptom resolution in 96% of cases. Various technical maneuvers have been described to decrease pseudoaneurysm formation. Placing the running suture more tightly to oversew any transected vessels at the nephrectomy bed is one example. During hemostatic renorrhaphy, one should try to avoid unnecessary renal parenchymal puncture. Avoidance of hemostatic material over the resection bed that may separate the cut edges of the renal parenchyma and delay close tissue approximation has also been described. We should always be aware of renal artery pseudoaneurysm after partial nephrectomy, and arrange angiography for both diagnosis and treatment if highly suspected.