Negative renal angiography with subsequent denied angioembolization: findings in a series of 180 patients at a tertiary interventional uroradiology unit

Background Renal arterial embolization (RAE) is considered to be a safe and effective method for treating a variety of renal lesions and pathology. It is the optimal method not only to stop bleeding, but to preserve renal parenchyma and renal function. Patients who are scheduled to RAE who showed negative catheter angiography with the procedure subsequently denied have a special concern because they are subjected to unnecessary procedure with its complications and didn’t get its benefits. This circumstance is infrequently reported in the literature, and that compelled us to identify the predictors of negative renal angiography findings that would result in a failure to undertake RAE. Results The study included 180 patients (126 males; 70%) with a mean ± SD age of 44 ± 14 years. Iatrogenic causes were the most common indication for RAE (108 of 180; 60%), while spontaneous unknown reasons constituted (17 of 180 patients; 9%). Angiography showed various lesions in 148 patients: pseudoaneurysm (80 of 148; 54%), tumours (28 of 148; 19%), arteriovenous (AV) fistulas (22 of 148; 15%) and both pseudoaneurysm and AV fistulas (18 of 148; 12%). However, in the remaining 32 of 180 patients (18%) no lesions were identified on renal angiography and RAE procedures were not undertaken. On bivariate analysis, neither gender, side of the lesions, haematuria prior to RAE, or renal artery anatomy were predictors for negative angiography. However, the indication for RAE (spontaneous unknown reasons) of renal haemorrhage was the only predictor for negative angiography (9/17 (53%), P = 0.001). Conclusion Patients scheduled for RAE may show negative findings with no lesions on renal angiography. Among the different indications for RAE, patients with spontaneous (unknown) have the highest probability (53%) of being associated with negative renal angiography findings, however, those with renal tumours and post-traumatic causes have a low probability. In those patients with spontaneous (unknown), conservative management should be the initial treatment of choice in order to avoid unnecessary RAE and its associated complications.

Cadaveric Study of Anatomical Variations of Renal Arteries

Introduction: Anatomical variations of renal artery are important to prevent complications during renal transplant surgery or renal angiography. Of this additional renal artery is the most common. Materials and methods: The present study was conducted in 80 kidneys of 40 adult human cadavers in Department of Anatomy, Siddhartha Medical College, Vijayawada over a period of 4 years (2017 to 2021) during educational dissections. Results: Accessory renal arteries are observed in the present study. Origins of these accessory renal arteries are noted along with their entry point into the kidneys. These results were compared with previous studies. Conclusion: Prior knowledge of these variations is important to prevent complications during surgical and angiographic interventions. Keywords: Renal arteries, Accessory renal artery, Aberrant renal artery, Upper pole, Lower pole, Hilum.

Magnetic resonance imaging with gradient sound respiration guide

Respiratory motion management is crucial for high-resolution MRI of the heart, lung, liver and kidney. In this article, respiration guide using acoustic sound generated by pulsed gradient waveforms was introduced in the pulmonary ultrashort echo time (UTE) sequence and validated by comparing with retrospective respiratory gating techniques. The validated sound-guided respiration was implemented in non-contrast enhanced renal angiography. In the sound-guided respiration, breathe−in and–out instruction sounds were generated with sinusoidal gradient waveforms with two different frequencies (602 and 321 Hz). Performance of the sound-guided respiration was evaluated by measuring sharpness of the lung-liver interface with a 10–90% rise distance, w10-90, and compared with three respiratory motion managements in a free-breathing UTE scan: without respiratory gating (w/o gating), 0-dimensional k-space navigator (k-point navigator), and image-based self-gating (Img-SG). The sound-guided respiration was implemented in stack-of-stars balanced steady-state free precession with inversion recovery preparation for renal angiography. No subjects reported any discomfort or inconvenience with the sound-guided respiration in pulmonary or renal MRI scans. The lung-liver interface of the UTE images for sound-guided respiration (w10-90 = 6.99 ± 2.90 mm), k-point navigator (8.51 ± 2.71 mm), and Img-SG (7.01 ± 2.06 mm) was significantly sharper than that for w/o gating (17.13 ± 2.91 mm; p < 0.0001 for all of sound-guided respiration, k-point navigator and Img-SG). Sharpness of the lung-liver interface was comparable between sound-guided respiration and Img-SG (p = 0.99), but sound-guided respiration achieved better visualization of pulmonary vasculature. Renal angiography with the sound-guided respiration clearly delineated renal, segmental and interlobar arteries. In conclusion, the gradient sound guided respiration can facilitate a consistent diaphragm position in every breath and achieve performance of respiratory motion management comparable to image-based self-gating.

Renal Artery Pseudo-aneurysms: Do All of Them Require Endovascular Management?

Purpose: Our study examines the etiological profile, clinical and imaging features of renal artery pseudo aneurysms (RAPs), as well as the efficacy and need for the angioembolization of RAPs in a resource-constrained setting. Materials and Methods: A total of 36 patients with RAPs were included in our study. Initial diagnosis was made by Doppler Ultrasonography (USG) followed by CT renal angiography in all cases. DSA was performed in 28 patients, as eight patients showed spontaneous resolution by thrombosis on immediate pre-procedure Doppler study. Angioembolization with a microcoil was performed for 30 aneurysms in 28 patients. Technical success was confirmed at the end of the procedure by a renal angiogram. To assess clinical success, we followed up with patients (with clinical and Doppler USG) for a period of six months. Results: The most common cause of RAPs in our study was percutaneous nephrolithotomy (PCNL), seen in 21 patients (58.3%), followed by trauma (25%), and partial nephrectomy (11%). All patients presented to us were within 21 days of the etiological event of hematuria or flank pain. USG was able to detect the RAP in 22 cases (61%). CT renal angiography was diagnostic in all patients but failed to demonstrate two additional aneurysms in one patient. RAP size ≤ 4 mm and absence of brisk filling on CT renal angiography was associated with spontaneous resolution in eight patients, probably an indication of the beginning of spontaneous thrombosis. Angioembolization was done using microcoils and showed 100% technical and clinical success. Conclusion: PCNL is the most common etiological factor for RAPs in our setting. Such patients should have a Doppler USG done prior to discharge from the hospital. CT angiographic flow dynamics (delayed peak enhancement) may be helpful in the identification of RAPs with a high probability of subsequent spontaneous resolution. Angiography followed by embolization using microcoils is the most effective and safe treatment for RAPs with no significant loss of renal parenchyma, although cost remains a limiting factor in our setting.

Subcostal artery bleeding after percutaneous nephrolithotomy: a case report and literature review

Postoperative bleeding is a dangerous complication after percutaneous nephrolithotomy (PCNL). Pseudoaneurysm, arteriovenous fistula, and arterial laceration are the three most common causes of post-PCNL bleeding. Subcostal artery bleeding is a rare cause. We herein present a clinical case involving a 43-year-old man who presented with right renal complex calculi and was managed by PCNL in the prone position using an inferior calyceal puncture approach. Intermittent extreme bleeding occurred 1 day postoperatively, and immediate renal angiography was performed. However, we found no sign of a pseudoaneurysm, arteriovenous fistula, or arterial laceration. Another well-trained and experienced doctor also found no pseudoaneurysm, arteriovenous fistula, or arterial laceration. After adjusting the catheter position, subcostal artery bleeding finally appeared and was successfully controlled by coils. This finding indicates that subcostal artery damage is one cause of post-PCNL bleeding. We suggest that clinicians should carefully and patiently perform angiography and/or embolization to avoid misdiagnosis and mistreatment.