Management of Postbiopsy Arteriovenous Fistulas in Transplanted Kidneys and Effectiveness of Endovascular Treatment: A Single-center Experience

Emergency endovascular and percutaneous urological interventions: A pictorial review

Emergency endovascular and percutaneous urological interventions encompass various diagnostic and therapeutic procedures to address various genitourinary conditions. These urological interventions are life-saving in addressing complications following biopsy, post-nephrectomy, post-transplant, and post-trauma. Compared to other surgical fields, there are relatively fewer urological emergencies. However, they require prompt radiological diagnosis and urgent interventions. This pictorial essay emphasizes various urological emergencies and urgent interventional management.

Arteriovenous fistula in a renal allograft with gross hematuria and subsequent acute kidney injury due to urinary tract obstruction: a case report

BACKGROUND

Arteriovenous fistula (AVF) due to renal allograft biopsy is mechanical trauma resulting from the penetration of small arteries and veins by a core needle. Most AVFs are reported to resolve asymptomatically and spontaneously. This report presents a patient with acute kidney injury (AKI) due to urinary tract obstruction caused by a bleeding AVF in a renal allograft.

CASE PRESENTATION

A 22-year-old Japanese woman who underwent living-donor kidney transplantation (KT) at 3 years due to end-stage renal disease caused by focal segmental glomerulosclerosis (FSGS) presented with a renal transplant AVF (gourd-shaped; 42 × 19 × 20 mm). The AVF was unexpectedly discovered by ultrasound before a surveillance biopsy at 10 years after KT. The patient had a history of recurrent FSGS, had undergone several renal allograft biopsies after KT, and did not experience symptoms or growth of the AVF for years. Nineteen years after KT, the patient developed AKI with sudden, asymptomatic, gross hematuria and anuria. Plain computed tomography revealed a hematoma in the pelvis of the renal allograft and bladder tamponade. The AVF was successfully treated by coil embolization. Hemodialysis was performed for AKI, and graft function was gradually recovered.

CONCLUSIONS

Unexpected bleeding from a renal transplant AVF may lead to transplant dysfunction. Angiographic embolization against the ruptured renal transplant AVF may prevent rebleeding and rescue the renal allograft.

Postoperative and Recurrent Hematuria after Pretransplant Core Needle Biopsy in Living Donor Kidney Transplant

Background

Core needle and wedge biopsies are the two main pathologic ways to determine the suitability of a kidney allograft and to have a baseline allograft biopsy in case of future rejection. Case Presentation. A 57-year-old patient developed a renal arteriovenous fistula causing postoperative and recurrent hematuria after allograft pretransplant renal core needle biopsy and treated with selective Interventional radiology coil embolization.

Conclusion

Delayed profound hematuria can be seen after pretransplant core needle renal biopsies and can recur again even after complete resolution, due to arteriovenous fistula formation in the renal calyceal system.

Treatment of Post-biopsy Arteriovenous Fistula of a Renal Graft by Selective Embolization

The development of an arteriovenous fistula (AVF) after renal graft biopsy is a rare complication, it is associated in most cases with spontaneous resolution. However, interventional therapies are required in some cases, to prevent graft loss. Selective embolization has been described as an alternative treatment. In the present study, we describes our experience on AVF after biopsy in kidney transplant patients, which was managed with selective embolization. From 2005 to 2015, a total of 452 kidney transplant biopsies were performed, 12 had an AVF requiring embolization. In 92% of cases, this was successful. Beforehand, mean serum creatinine levels were 2.45 mg/dL, after the procedure, that increased to 3.05, however, 3 months later, mean creatinine levels dropped to 1.85 mg/dL. Graft survival after 2 follow-up years was 72%. Our experience demonstrates that selective embolization of the AVF after kidney transplant biopsy is a safe procedure, and that transplant function can be maintained in patients with this complication.

ACR Appropriateness Criteria® Renal Transplant Dysfunction

Renal transplantation is the treatment of choice in patients with end-stage renal disease because the 5-year survival rates range from 72% to 99%. Although graft survival has improved secondary to the introduction of newer immunosuppression drugs and the advancements in surgical technique, various complications still occur. Ultrasound is the first-line imaging modality for the evaluation of renal transplants in the immediate postoperative period and for long-term follow-up. In addition to depicting many of the potential complications of renal transplantation, ultrasound can also guide therapeutic interventions. Nuclear medicine studies, CT, and MRI are often helpful as complementary examinations for specific indications. Angiography remains the reference standard for vascular complications and is utilized to guide nonsurgical intervention. The American College of Radiology Appropriateness Criteria are evidence-based guidelines for specific clinical conditions that are reviewed annually by a multidisciplinary expert panel. The guideline development and revision include an extensive analysis of current medical literature from peer-reviewed journals and the application of well-established methodologies (RAND/UCLA Appropriateness Method and Grading of Recommendations Assessment, Development, and Evaluation or GRADE) to rate the appropriateness of imaging and treatment procedures for specific clinical scenarios. In those instances where evidence is lacking or equivocal, expert opinion may supplement the available evidence to recommend imaging or treatment.

Hemodynamic characteristics and the occurrence of renal biopsy-related arteriovenous fistulas in native kidneys

Purpose

Renal biopsy-related arteriovenous fistula (RB-AVF), although usually asymptomatic, may sometimes result in serious clinical implications. The aim of the study was to prospectively evaluate the incidence of RB-AVF in native kidneys, together with the assessment of hemodynamic characteristics and the impact of the histopathological results of biopsy.

Methods

The study included 138 patients (age 46.2 ± 15.2; 70 F, 68 M), who underwent percutaneous renal biopsy (PRB) of the native kidney. In all patients, 2D and color Doppler ultrasound was performed 24 h after PRB in order to exclude RB-AVF.

Results

Bleeding complications in the form of hematomas were found in 136 patients (98.55 %), and 23 cases of RB-AVF were observed (16.67 %). RB-AVF group had an increased maximal hematoma diameter and reduced number of glomeruli in PRB. The segmental arteries supplying the fistulas are characterized by higher maximum flow velocity (FV) and a lower resistance index (RI) compared to the normal segmental arteries (difference 45.9 ± 20.0 cm/s and 0.252 ± 0.104, respectively). In the ROC analysis, RI ≤ 0.524 allowed to detect RB-AVF with a sensitivity of 91 % and specificity of 100 % (AUC 0.998, p < 0.001). In approximately 39 % of RB-AVF cases, 2D ultrasound detected a hyperechogenic ischemic area between the fistula and the renal capsule.

Conclusions

Arteriovenous fistula is a quite frequent complication of native renal biopsy and can cause ischemia in the renal parenchyma detected by ultrasound. The arteries supplying the fistula are characterized by an increased flow velocity and reduced resistance index.

Endovascular interventions for managing vascular complication of renal transplantation

Renal transplantation is a well-established treatment for patients with end-stage renal disease. Although the procedure is commonly undertaken with a high rate of initial technical success, a low but significant risk of vascular complications can develop and ultimately threaten the transplanted kidney. Complications include transplant renal artery stenosis, extraparenchymal and intraparenchymal pseudoaneurysm and arteriovenous fistula formation, and stenosis of native iliac arteries due to aortoiliac occlusive disease. Historically, open surgical correction of these complications has been associated with high morbidity and the risk of graft loss. Endovascular approaches are better tolerated by renal transplantation patients and are used increasingly for management of vascular complications associated with kidney transplantation. We review the contemporary diagnosis and treatment of these complications using endovascular techniques.