Effects of Superselective Embolization for Renal Vascular Injuries on Renal Parenchyma and Function

The Implications of Acute Anatomic Injury After Percutaneous Renal Intervention

PURPOSE

Percutaneous renal artery revascularization for hypertension and renal dysfunction remains common. The frequency, cause, and outcomes of anatomic injury associated with renal intervention are poorly delineated. This study aims to determine the frequency of acute anatomic renal injury after renal artery interventions, identify factors associated with anatomic renal injury, and determine whether anatomic renal injury related to renal intervention is associated with late adverse clinical events.

METHODS

A retrospective analysis of patients undergoing renal artery interventions for atherosclerotic renal artery disease between 2002 and 2022 was performed. Acute anatomic renal injury encompassed renal artery dissection, renal artery perforation, acute occlusion, renal parenchymal infarction, and renal parenchymal perforation. Freedom from renal-related morbidity (increase in persistent creatinine >20% of baseline, progression to hemodialysis, death from renal-related causes) and patient survival were measured.

RESULTS

A total of 968 patients underwent 1309 renal artery interventions: 47% for hypertension, 25% for hypertension associated with chronic renal dysfunction, and 28% for chronic renal dysfunction. An acute anatomic renal injury occurred in 5.9% of the patients. The occurrence of an anatomic injury was associated with a significant decrement in freedom from renal-related morbidity (79±2% vs 55±8%, no-injury vs injury group, mean±standard error of the mean; p=0.003) and markedly decreased survival at 5 year follow-up (78±3% vs 48±8%; p=0.002). No factor was identified that predicted anatomic injury. In those patients with anatomic injury, perforation was associated with decreased survival, while estimated glomerular filtration rate <60, resistive index >0.8, and dissection were associated with a lack of retained renal benefit.

CONCLUSION

Acute anatomic renal injury occurs in approximately 6% of patients undergoing percutaneous renal artery intervention and is a negative predictor of survival and is associated with subsequent renal failure, need for dialysis, and death from renal-related causes.

CLINICAL IMPACT

Acute anatomic renal injury occurs in approximately 5% of patients undergoing percutaneous renal artery intervention. Modern endovascular interventions allow for the control and remediation of injuries in the majority of cases with an overall low mortality and morbidity. There is a significant early occlusion of renal arteries following the injury within 1 month. In the long term, the occurrence of injury is a negative predictor of survival and is associated with subsequent renal failure, the need for dialysis, and death from renal-related causes.

Hemorrhagic complicationes after percutaneous nephrolithotomy: The importance of an early endovascular management

INTRODUCTION AND OBJECTIVES

Hemorrhage due to arteriovenous fistula (AVF) or pseudoaneurysm (PA) is a rare complication after percutaneous nephrolithotomy (PCNL). The objective of this study is to evaluate hemorrhagic complications (HC) after PCNL and the results of their endovascular treatment.

MATERIALS AND METHODS

Between May 2009 and December 2019, 1335 PCNL were performed in our center for kidney stone disease. We analyzed the incidence of early and late HC, their management, the need for subsequent embolization, as well as clinical and analytical data of these patients.

RESULTS

A total of 59 (4.4%) patients presented HC. Bleeding was managed with arteriography and selective embolization (ASE). Perirenal hematoma was seen in 38 patients (64%). Regarding angiographic findings, there were 32 (54%) PA, 8 (14%) AVF, 4 (7%) extravasations due to vascular laceration and 15 (25%) PA combined with AVF. In one case, 3 procedures were required to control the bleeding. In 30 patients (51%) blood transfusions were not necessary, while in 29 (49%), a mean of 1.3 units were transfused. Median follow-up was 24 ± 21 months. Mean time interval between PCNL and ASE was 7.3 ± 4.9 days. A total of 24 (41%) patients were readmitted after discharge due to late HC requiring ASE. Delay between readmission and ASE was 4.8 ± 4.6 h in average.

CONCLUSION

Early and late HC after PCNL can be severe. Rapid identification and treatment with ASE is an effective and minimally invasive and avoids multiple blood transfusions which in many cases constitute an insufficient treatment.

N-Butyl Cyanoacrylate Embolization in Management of Iatrogenic Renal Hemorrhages—Single-Center Study Evaluating Safety and Efficacy

Objectives: The aim of the study was to evaluate the efficacy of endovascular N-butyl cyanoacrylate (NBCA)/glue embolization alone in the management of iatrogenic renal injuries and its effect on renal function.

Methods: Thirty-one patients who presented with significant iatrogenic renal injuries over a time period ranging from June 2013 to June 2018 were evaluated. The clinical features, lab parameters, and imaging findings were recorded. The embolizing agent used was exclusively NBCA. The success rate was calculated along with the effect of glue embolization on kidney in the form of postembolization ischemia and change in the serum creatinine levels in immediate pre- and postembolization period. The time between the iatrogenic injury and angioembolization as well as the time from angioembolization to discharge was also calculated. Recurrence was evaluated at 1 and 6 months follow-up.

Results: NBCA embolization showed 100% technical and clinical success in our study and no recurrence was noted at follow-up. Glue was also able to achieve complete embolization in patients with coagulopathy (n = 14, 45.1%). Percentage area deficit of normal renal blush in the postembolization check angiogram varied from 4 to 15.7% with a mean deficit of 7.65%. No significant difference in the serum creatinine was noted in immediate postembolization period.

Conclusions: We conclude that glue is an effective embolizing agent for management of iatrogenic renal injuries even in coagulopathy patients with minimal area of parenchymal loss, no significant effect on renal functions, and no recurrence on 6 months follow-up.

Hemorrhagic complicationes after percutaneous nephrolithotomy: The importance of an early endovascular management

INTRODUCTION AND OBJECTIVES

Hemorrhage due to arteriovenous fistula (AVF) or pseudoaneurysm (PA) is a rare complication after percutaneous nephrolithotomy (PCNL). The objective of this study is to evaluate hemorrhagic complications (HC) after PCNL and the results of their endovascular treatment.

MATERIALS AND METHODS

Between May 2009 and December 2019, 1335 PCNL were performed in our center for kidney stone disease. We analyzed the incidence of early and late HC, their management, the need for subsequent embolization, as well as clinical and analytical data of these patients.

RESULTS

A total of 59 (4.4%) patients presented HC. Bleeding was managed with arteriography and selective embolization (ASE). Perirenal hematoma was seen in 38 patients (64%). Regarding angiographic findings, there were 32 (54%) PA, 8 (14%) AVF, 4 (7%) extravasations due to vascular laceration and 15 (25%) PA combined with AVF. In one case, 3 procedures were required to control the bleeding. In 30 patients (51%) blood transfusions were not necessary, while in 29 (49%), a mean of 1.3 units were transfused. Median follow-up was 24±21 months. Mean time interval between PCNL and ASE was 7.3±4.9 days. A total of 24 (41%) patients were readmitted after discharge due to late HC requiring ASE. Delay between readmission and ASE was 4.8±4.6hours in average.

CONCLUSION

Early and late HC after PCNL can be severe. Rapid identification and treatment with ASE is an effective and minimally invasive and avoids multiple blood transfusions which in many cases constitute an insufficient treatment.

Impact of Superselective Renal Artery Embolization on Renal Function and Blood Pressure

Objectives:

To evaluate the effect of superselective renal artery embolization in terms of renal function and blood pressure, to compare the results between groups with different embolization extents, and to analyze risk factors of entire study population for postprocedural acute kidney injury (AKI).

Materials and Methods:

The inclusion criteria were patients who underwent renal artery embolization from January 2009 to December 2019, with available serum creatinine and blood pressure data. The exclusion criteria were non-selective embolization of main renal artery, AKI before embolotherapy, and follow-up of less than one month. According to the extent of embolization, the patients were divided into two groups: Group A (1 segment) and Group B (2–4 segments).

Results:

A total of 48 patients were enrolled. There was a significant difference between pre- and postprocedural estimated glomerular filtration rate (p = 0.030). There were no significant difference between pre- and postprocedural blood pressure. The incidence of postprocedural AKI in group B was significantly higher than that in group A (p = 0.044). There was no significant difference in the incidence of the worsening of hypertension between the two groups. Chronic kidney disease and high embolization grade were predictive for postprocedural AKI (p = 0.012, 0.021).

Conclusion:

Superselective embolization appears to be a safe procedure, but meticulous attention for AKI is required for patients who underwent embolization of more than one segmental artery. An attempt to minimize the extent of devascularization should be pursued to avoid postprocedural complications.

Arteriovenous fistulas after ultrasound-guided needle biopsy of kidney allografts and treatment outcomes after transcatheter embolization: A single-center experience in Japan

BACKGROUND

Arteriovenous fistula (AVF) is one of the vascular complications after allograft biopsy, and their reported incidence rates range widely. Transcatheter embolization (TE) is a common AVF treatment in kidney allografts. However, information on AVF incidence and features and TE outcomes in Japanese kidney transplant (KT) recipients is lacking.

METHODS

This study investigated 270 protocol or clinically indicated kidney allograft biopsies in 129 KT recipients during 2010-2016 at a single-center using standardized methods (16-gauge needle and ultrasound guidance). We recorded the incidence and clinical features of AVF using currently recommended standardized methods of allograft biopsy and TE outcomes regarding allograft function up to 12 months after the procedure in Japanese KT recipients.

RESULTS

AVF incidence was 2.6% (seven cases). The time from biopsy to AVF diagnosis was 7 (median, interquartile range: 5-117, range: 1-318) days. The time from biopsy to AVF diagnosis was significantly shorter in symptomatic cases (gross hematuria) than in asymptomatic cases (median 6 vs. 117 days, p = 0.034). Symptomatic patients underwent TE within a shorter time (0-6 days) than asymptomatic patients (25-104 days). There were no complications, and allograft function was stable up to 12 months after TE despite using contrast media and partial renal infarction.

CONCLUSIONS

AVF does occur in certain probabilities. AVF formation can occur without apparent bleeding and exist for a long time after allograft biopsy. TE is a safe and immediate treatment for AVF in kidney allograft.

Initial Experience With the Microvascular Plug in Selective Renal Artery Embolization

Purpose:

To evaluate the safety and efficacy of the microvascular plug (MVP) for selective renal artery embolization.

Methods:

Retrospective review was performed on a cohort of 6 patients undergoing renal artery embolization using the MVP between July 2015 and August 2018. Patients’ demographics, indication for embolization, technical details of the embolization procedure, and clinical events were gathered from the patients’ electronic medical records.

Results:

The patients underwent selective renal artery embolization with a MVP for iatrogenic vascular injuries (n = 3), traumatic vascular injuries (n = 2), and for elective embolization of an angiomyolipoma (n = 1), in native kidneys (n = 4) or in renal allografts (n = 2). Immediate occlusion of the feeding artery was achieved with 1 MVP device in 4 patients. In 1 patient, a second MVP was needed, and in another patient, additional 0.018-inch microcoils were used to completely occlude the injured artery. Technical success was achieved in all patients. The volume of the resulting renal infarction was estimated less than 5% of the renal volume. No other procedure-related complications occurred.

Conclusion:

The MVP is a safe and effective device allowing superselective renal artery embolization. Therefore, we recommend the MVP as a valuable embolic in superselective renal artery embolization. Additionally, a single device is sufficient in most cases, potentially reducing the cost, duration, and radiation exposure of the procedure.

Prolonged international normalized ratio and vascular injury at divisional level predict embolization failures of patients with iatrogenic renal vascular injuries

Transcatheter arterial embolization (TAE), as an alternative to surgery for iatrogenic renal vascular injury (IRVI), may have unsatisfactory outcomes. Nonetheless, there is inadequate information regarding the predictors of TAE outcomes for IRVI in the literature. The aim of this retrospective study was to investigate the predictors of TAE outcomes for IRVI. Of 47 patients, none had major complications, 17 (36.2%) patients had minor complications, and none suffered significant renal function deterioration after TAE. Technical success and clinical success were 91.5% and 93.6%, respectively. Technical failure was associated with older age, thrombocytopenia, prolonged international normalized ratio (INR) and divisional IRVI. Clinical failure was associated with kidney failure, use of steroids, prolonged INR, and divisional IRVI. In addition, prolonged INR was a significant predictor of technical failure. This implies that aggressive measures to control the INR prior to TAE are warranted to facilitate technical success, and technical success could then be validated on post-TAE images. Furthermore, divisional IRVI was a predictor of clinical failure. Thus, divisional IRVI should undergo surgery first since TAE is prone to clinical failure. The avoidance of clinical failure is validated if divisional IRVI does not need further intervention.

The associations between initial radiographic findings and interventions for renal hemorrhage after high-grade renal trauma: Results from the Multi-Institutional Genitourinary Trauma Study

BACKGROUND

Indications for intervention after high-grade renal trauma (HGRT) remain poorly defined. Certain radiographic findings can be used to guide the management of HGRT. We aimed to assess the associations between initial radiographic findings and interventions for hemorrhage after HGRT and to determine hematoma and laceration sizes predicting interventions.

METHODS

The Genitourinary Trauma Study is a multicenter study including HGRT patients from 14 Level I trauma centers from 2014 to 2017. Admission computed tomography scans were categorized based on multiple variables, including vascular contrast extravasation (VCE), hematoma rim distance (HRD), and size of the deepest laceration. Renal bleeding interventions included angioembolization, surgical packing, renorrhaphy, partial nephrectomy, and nephrectomy. Mixed-effect Poisson regression was used to assess the associations. Receiver operating characteristic analysis was used to define optimal cutoffs for HRD and laceration size.

RESULTS

In the 326 patients, injury mechanism was blunt in 81%. Forty-seven (14%) patients underwent 51 bleeding interventions, including 19 renal angioembolizations, 16 nephrectomies, and 16 other procedures. In univariable analysis, presence of VCE was associated with a 5.9-fold increase in risk of interventions, and each centimeter increase in HRD was associated with 30% increase in risk of bleeding interventions. An HRD of 3.5 cm or greater and renal laceration depth of 2.5 cm or greater were most predictive of interventions. In multivariable models, VCE and HRD were significantly associated with bleeding interventions.

CONCLUSION

Our findings support the importance of certain radiographic findings in prediction of bleeding interventions after HGRT. These factors can be used as adjuncts to renal injury grading to guide clinical decision making.

LEVEL OF EVIDENCE

Prognostic and Epidemiological Study, Level III and Therapeutic/Care Management, Level IV.

Hypertension Caused by Renal Arteriovenous Fistula with Multiple Renal Artery Aneurysms

Renal arteriovenous fistula with renal artery aneurysms and dilated renal veins presents as an infrequent lesion. Endovascular therapy has recently been considered the first-line treatment for these conditions. We report a case of a patient with idiopathic renal arteriovenous fistula concomitant with multiple renal artery aneurysms that was successfully treated by the placement of a covered stent.

Renal Arterial Pseudoaneurysm After Partial Nephrectomy: Literature Review and Single-Center Analysis of Predictive Factors and Renal Functional Outcomes

INTRODUCTION AND OBJECTIVE

Partial nephrectomy (PN) represents the current surgical standard for T1 tumors. Renal arterial pseudoaneurysm is a rare but potentially life-threatening complication reported after PN. The aim of this study was to identify the factors associated with the occurrence of pseudoaneurysm after PN, specifically focusing on those requiring management with selective embolization. A literature review of the topic was performed.

METHODS

A retrospective review of the institutional PN database was performed from January 2011 to December 2016. Patients who underwent embolization for pseudoaneurysm represented a separated cohort to be compared with other patients (controls). Patients' and tumors' characteristics were considered. Univariable and multivariable analyses were used to test their eventual association with the occurrence of pseudoaneurysm.

RESULTS

A total of 1417 cases were evaluated. At a median of 21 days (interquartile range = 10-34), 20 patients (1.4%) developed postoperative pseudoaneurysm. The majority of patients (70%) presented with gross hematuria. The clinical suspicion was confirmed by contrast-enhanced computed tomography scan with angiography. Selective embolization was performed using endovascular coils. Technical success and clinical success rates were 100% and 95%, respectively. No difference was found in percentage estimated glomerular filtration rate (eGFR) preserved between patients who underwent embolization versus controls (median 82.6% versus 86.3%, P = .35). No differences in age, baseline renal function (as assessed by glomerular filtration rate [GFR]), tumor size, and R.E.N.A.L. were found between patients who reported and did not report pseudoaneurysm. In patients who developed pseudoaneurysm, longer operative time (225.6 minutes versus 193 minutes, P = .04), and cold ischemia time (48 minutes versus 29 minutes, P = .03) were reported.

CONCLUSION

In our series, the occurrence of pseudoaneurysm was associated with longer operative and cold ischemia times. In patients who underwent selective embolization, renal function remained comparable with that of controls.

Changing etiology and management patterns for spontaneous renal hemorrhage: a systematic review of contemporary series

OBJECTIVE

To conduct a systematic literature review on spontaneous renal hemorrhage (SRH) in a contemporary cohort describing patterns in etiology and treatment.

METHODS

A systematic search of MEDLINE and CENTRAL databases was conducted to include articles, including case reports and case series on SRH published from 2000 to 2016. Full-text manuscripts were reviewed for clinical parameters which were collated and analyzed with univariate methods.

RESULTS

Seventy-nine publications met inclusion criteria, reporting on 102 cases. Renal neoplasms (56.9%) and polyarteritis nodosa (PAN) (11.8%) remained as the most common overall and vascular causes of SRH, respectively. Angiomyolipoma (AML) was the most common causative renal neoplasm (74.1%), and patients were more likely to be female and present with macroscopic hematuria than those with vasculitis, while malignant neoplasms were more common in men. Proportions of SRH due to malignant neoplasms (specifically renal cell carcinoma, RCC) were reported less than PAN. Among this contemporary series, transarterial embolization (TAE) was most commonly used for acute SRH (42.2%).

CONCLUSIONS

Renal neoplasms remain as the most common cause of SRH, of which AML predominates, while PAN is currently the second most common etiology in acute SRH, replacing RCC. Minimally invasive approaches, such as TAE and conservative/medical management, were preferred to initial surgery.

SYSTEMATIC REVIEW REGISTRATION

PROSPERO registration number CRD42017069222.

Analysis of repeated renal arteriography after percutaneous nephrolithotomy

To review the clinical data of the patients who required repeated renal arteriography following initial super-selective renalartery embolization (SRAE) after Percutaneous Nephrolithotomy (PCNL) and to analyze the reasons for the failure. We retrospectively reviewed the data of the patients who underwent repeat renal arteriography after PCNL for persistent or recurrent severe hemorrhage from August 2001 through August 2015 at our hospital. Total of 427 SRAEs were performed in 369 patients who had undergone PCNL. 21 patients had repeated renal arteriography. Among them, 12 required 2 sessions, 5 required 3 sessions, 1 required 4 sessions, and 3 required 5 sessions. In those 37 repeated renal arteriography, 7 were due to missed pseudoaneurysm, 5 for recanalization of the embolized vessels, and finding of new renal vascular lesions in 22. These new findings included new pseudoaneurysm in sixteen, new arterio-venous fistula (AVF) in two, combination of new pseudoaneurysm and AVF in four, and no identifiable abnormity in three. Except for the missed pseudoaneurysm and the recanalization of the embolized vessels, new renal vascular lesion was the major reason for the repeated arteriography in our hospital. The cause of these new renal vascular lesions was unknown. The lesion might be missed during the initial arteriography due to arterial spasm. Progressive deterioration of the injured vessel integrity could be the other possibility.

The epidemiology of renal trauma

Introduction

Nonoperative and minimally invasive management techniques for both blunt and penetrating renal trauma have become standard of care over the past decades. We sought to examine the modern epidemiology of renal trauma over the past decade.

Methods

A systematic review of PubMed from the past decade was conducted to examine adult and pediatric renal trauma. A total of 605 articles were identified. Of these, 15 adult and 5 pediatric articles met our a priori search criteria.

Results

There is a lack of uniform reporting of the renal trauma demographics precluding accurate assessment. Despite this, we were able to elucidate the following details. Renal trauma predominately affects young adult males, and the etiology is predominantly blunt. Among blunt injuries, motor vehicle crashes are most common among adult and pediatric patients. Nonoperative care was utilized in 94.8% of reviewed manuscripts with a 5.4% nephrectomy rate.

Discussion

There do not appear to be any startling changes in the presentation of adult and pediatric renal trauma over the past decade. Nonoperative care continues to be utilized as primary therapy. Increased attention on the reporting of renal trauma demographics is necessary to improve detection of trends.

Conclusions

Increased reporting of the presenting demographics of adult and pediatric renal trauma is encouraged to assist future assessment of epidemiology.

The role of interventional radiology in abdominopelvic trauma

The management of trauma patients has evolved in recent decades owing to increasing availability of advanced imaging modalities such as CT. Nowadays, CT has replaced the diagnostic function of angiography. The latter is considered when a therapeutic option is hypothesized. Arterial embolization is a life-saving procedure in abdominopelvic haemorrhagic patients, reducing relevant mortality rates and ensuring haemodynamic stabilization of the patient. Percutaneous transarterial embolization has been shown to be effective for controlling ongoing bleeding for patients with high-grade abdominopelvic injuries, thereby reducing the failure rate of non-operative management, preserving maximal organ function. Surgery is not always the optimal solution for stabilization of a patient with polytrauma. Mini-invasivity and repeatability may be considered as relevant advantages. We review technical considerations, efficacy and complication rates of hepatic, splenic, renal and pelvic embolization to extrapolate current evidence about transarterial embolization in traumatic patients.

Experience of renal artery embolization in patients with blunt kidney trauma

Introduction

The ren is considered as the most commonly damaged genitourinary organ. In general, blunt kidney traumas (BKT) are mild and can be managed conservatively. We aimed to analyze our own experiences of selective renal artery embolization (RAE) in BKT patients and compare obtained results with other reports.

Material and methods

We analyzed the medical and technical outcomes of RAE in 20 patients with grades II-IV blunt kidney traumas. Indications for RAE were blunt kidney trauma combined with a gross hematuria that could not be stopped conservatively. For evaluating the functioning of kidneys we used radioisotope renography.

Results

According to the American Association for the Surgery of Trauma classification, grade II blunt kidney injury was registered at 2 (10.0%) pts, grade III – at 11 (55.0%) pts and grade IV – at 7 (35.0%) pts. In all patients, the bleeding was stopped with the embolization procedure. 18 (90.0%) patients were treated in a single interventional session and 2 (10.0%) needed further intervention. Different complications were registered as 5 (25%) pts: two or more complications were often combined in each individual case. The function in damaged kidneys was preserved at the 3^rd month after RAE sessions.

Conclusions

RAE is an effective, minimally invasive treatment for blunt kidney injury that ensures the cessation of gross hematuria and kidney function preserving.

Iatrogenic urinary tract injuries: etiology, diagnosis, and management

Iatrogenic injury to the urinary tract, including the kidneys, ureters, bladder, and urethra, is a potential complication of surgical procedures performed in or around the retroperitoneal abdominal space or pelvis. While both diagnostic and interventional radiologists often play a central and decisive role in the identification and initial management of a variety of iatrogenic injuries, discussions of these injuries are often directed toward specialists such as urologists, obstetricians, gynecologists, and general surgeons whose procedures are most often implicated in iatrogenic urinary tract injuries. Interventional radiologic procedures can also be a source of an iatrogenic urinary tract injury. This review describes the clinical presentation, risk factors, imaging findings, and management of iatrogenic renal vascular and urinary tract injuries, as well as the radiologist's role in the diagnosis, treatment, and cause of these injuries.

Gelatin-thrombin hemostatic matrix injection to salvage refractory post-renal graft biopsy bleed

Post-renal biopsy bleeding refractory to angioembolization usually requires graft nephrectomy as a life-saving measure. Gelatin-thrombin hemostatic matrix injection in the needle tract is a novel attempt to control bleeding in such cases and to salvage the allograft. We hereby describe two cases of post-graft biopsy bleed. Both these patients continued to bleed even after angioembolization. They were shifted to the operating room upon developing hypotension, having received multiple blood transfusions with the intention of performing graft nephrectomy to save their lives. However, bleeding was successfully controlled by using Gelatin-thrombin hemostatic matrix injection in the biopsy needle tract. Patients improved hemodynamically after the procedure. Graft function returned to normal in both the cases. At an average follow-up of 10.4 months, both the patients have shown stable graft functions.

Interventional radiology in renal trauma

Injury to the kidney is relatively common in significant abdominal trauma with the majority of injuries being secondary to a blunt rather than penetrating mechanism. Iatrogenic injury is an important additional cause of renal vascular damage. Multidetector computed tomography (CT) is the reference imaging modality in patients with suspected blunt, penetrating or iatrogenic injury. It allows rapid acquisition of images that accurately identify and stage injury to the kidneys and other major organs. This review addresses clinical indications for imaging, injury classification and the subsequent management of renal trauma, focusing on the important role of the interventional radiology team, particularly in stopping life-threatening haemorrhage by transcatheter embolisation techniques.

Percutaneous embolization of iatrogenic arterial kidney injuries: safety, efficacy, and impact on blood pressure and renal function

PURPOSE

To evaluate the efficacy and safety of percutaneous renal artery embolization (RAE) of iatrogenic vascular kidney injuries and the effects of RAE on renal function and arterial blood pressure (BP).

MATERIALS AND METHODS

Over a 12-year period, 50 consecutive patients with severe hemorrhage after iatrogenic arterial kidney injuries underwent RAE. Technical success was defined as occlusion of the bleeding site, and clinical success was defined as complete bleeding cessation. The effects on renal function and arterial BP were assessed by comparing the estimated glomerular filtration rate (eGFR), renal function stage (National Kidney Foundation scale), systolic BP, and BP stage (European Society of Hypertension classification) before and after RAE.

RESULTS

RAE was technically successful in 49 patients (98%). Two patients were lost to follow-up after RAE. Clinical success was obtained in 40 (83%), 45 (94%), and 47 patients (98%), respectively, at 24, 48, and 96 hours after RAE. Three patients (6%) had minor complications, and one patient (2%) died within 30 days after RAE. Follow-up renal function data (mean, 4 mo) were available for 33 patients (66%). No statistically significant differences in eGFR (P = .186) or renal function stage (P = .183) were apparent after RAE. Follow-up BP data (mean, 3 mo) were available for 28 patients (56%). There were no significant differences in systolic BP (P = .233) or BP stage (P = .745) after RAE.

CONCLUSIONS

Embolization of iatrogenic renal artery injuries is safe and associated with high technical and clinical success rates. It is not associated with a significant worsening of renal function or increase in BP.

Angiointervention: high rates of failure following blunt renal injuries

BACKGROUND

Nonoperative management (NOM) of solid organ injury after blunt trauma is now standard. Recently, angioembolization (AE) has been used to extend NOM. Few data exist on evaluating NOM of blunt renal injuries (BRIs). We sought to determine the overall efficacy of NOM as well as the outcome of AE in patients with BRI.

METHODS

The trauma registry was used to identify all patients with BRI between January 2002 and December 2008. Medical records were reviewed for demographics, grade of injury, use of angiographic intervention, and outcome.

RESULTS

A total of 434 patients with BRI were identified, 416 of whom had planned NOM; 337 (81%) patients were successfully managed without further intervention for their BRI. In all, 79 (19%) patients underwent angiography; 22 (27.8%) of these patients underwent AE, and 6 (27.2%) failed 1.2 ± 0.8 days after AE. Patients who failed AE had a significantly higher blood transfusion requirement during the first 24 h of admission (p = 0.01). Seven patients not embolized failed 1.9 ± 1.9 days after angiography. Thus, of the 79 patients having angiography, 13 (16.5%) failed and required laparotomy to treat their BRIs. Overall failure rate of NOM was 3.1% (13/416). Patients who failed angiography, with or without AE, required more blood during the first 24 h after admission (p = 0.03).

CONCLUSIONS

NOM of BRI is safe and effective, with an overall failure rate of 3.1%. However, angiography with or without AE has substantial failure rates. Patients with higher-grade injuries and active vascular extravasation on admission computed tomography scan also fail NOM regardless of therapy. The blood transfusion requirement during the first 24 h may indicate who will require operative intervention following angiography. Close observation and/or early laparotomy are wise for these high-risk patients.

Renal artery pseudoaneurysm following laparoscopic partial nephrectomy

OBJECTIVES

To present our experience with the management of renal artery pseudoaneurysms following laparoscopic partial nephrectomy (LPN).

METHODS

Our bi-institutional LPN database of 259 patients from July 2001 to April 2008 was queried for patients diagnosed with a postoperative renal artery pseudoaneurysm. Demographic data, perioperative course, complications, and follow-up studies in identified subjects were analyzed. Postembolization success was defined as symptomatic relief, resolution of hematuria, and a stable hematocrit and serum creatinine.

RESULTS

We identified 6 patients (2.3%) who were diagnosed with a renal artery pseudoaneurysm after LPN. The mean age of our cohort was 61.2 years (49-76), mean operative time was 208 minutes (140-265), and mean estimated blood loss was 408 mL (50-800). Patients presented at a mean of 12.6 days (5-23) after the initial surgery. Five patients had gross hematuria and a decreased hematocrit, with 1 patient presenting with clinical symptoms of hypovolemia. The sixth patient was incidentally diagnosed. The diagnosis of a renal artery pseudoaneurysm was confirmed in all cases by angiography. Selective angioembolization was successfully performed in all patients. At a median follow-up of 8.3 months all patients (100%) remained without any evidence of recurrence.

CONCLUSIONS

Although pseudoaneuryms are a rare postoperative complication of LPN, they are potentially life-threatening. Early identification and proper management can help reduce the potential morbidity associated with pseudoaneurysms. Our experience demonstrates the feasibility and supports the use of selective angioembolization as an excellent first-line option for patients who present with this form of delayed bleeding.

Renal trauma

Urinary tract injury occurs in 10% of all abdominal trauma patients, and the kidney is the most commonly injured organ in the urinary tract. CT with contrast enhancement is the modality of choice for cross-sectional imaging of renal trauma because it quickly and accurately can demonstrate injury to the renal parenchyma, renal pedicles, and associated abdominal or retroperitoneal organs. This article reviews the mechanism, clinical features, imaging modalities, and CT imaging findings according to the classification of the renal trauma. Trauma to underlying abnormal kidneys, iatrogenic renal injuries, and complications of renal trauma are reviewed also.

Visceral trauma: principles of management and role of embolotherapy

Interventional radiology for the treatment of traumatic visceral hemorrhage has emerged as an important adjunct to modern trauma care. This article outlines the general surgical concepts of the acute care of trauma patients as a guideline for catheter-based therapy. Specific considerations are presented for embolizing visceral injuries in the liver, spleen, and kidney. Expected outcomes and follow-up are reviewed.

Spontaneous occlusion of splenic and renal pseudoaneurysm after blunt abdominal trauma: a case report and literature review

Pseudoaneurysms caused by blunt abdominal trauma are rarely observed in solid organs. The preferred therapy for pseudoaneurysm after blunt abdominal trauma is often angiography and embolization. Here, we report a case of a spontaneous occlusion of splenic pseudoaneurysm and renal pseudoaneurysm after blunt abdominal trauma. Angiography and embolization were not required, and contrast-enhanced multi-detector computed tomography was used to monitor the patient. This case shows that spontaneous occlusion can be one of the possible outcomes of intraparenchymal splenic pseudoaneurysm and renal pseudoaneurysm after blunt abdominal trauma.

Superselective Embolization as First Step of Laparoscopic Partial Nephrectomy

OBJECTIVES

Laparoscopic partial nephrectomy is currently very hard to perform because of the great difficulty in obtaining renal parenchymal hemostasis during tumor excision and the consequent high risk of bleeding. The aim of this study was to propose a method to decrease the risk of bleeding, consisting of the superselective embolization of tumor vessels before performing the laparoscopic partial nephrectomy.

METHODS

Fifty patients with small, solitary, enhancing, predominantly exophytic renal tumors underwent a superselective radiographically guided embolization of tumor vessels. An average of 6 hours after embolization, the patients underwent partial laparoscopic nephrectomy, with transperitoneal access and three trocars placed, under balanced general anesthesia. The mean operative time was measured, as was the mean estimated blood loss.

RESULTS

The mean operative time was 90 minutes, the mean estimated blood loss was 200 mL, and the average hospital stay was 6 days. Complications were reported in only 2 patients. The final pathologic evaluation confirmed the diagnosis of renal cell carcinoma in 43 cases. The median follow-up was 11 months and, to date, the examinations have revealed no recurrences in any of the cases.

CONCLUSIONS

Superselective embolization is a valid option for laparoscopic partial nephrectomy. The procedure does not require any regional vascular control or clamping, reduces the estimated blood loss, and reduces the operative time.

Posttraumatic giant renal pseudoaneurysm

Renal artery pseudoaneurysms secondary to blunt abdominal trauma are uncommon. We report a giant renal pseudoaneurysm, diagnosed by computerized tomography 5 months after a blunt trauma, which was confirmed by catheter angiography and treated with selective embolization.

Percutaneous nephrostomy and antegrade ureteral stenting: technique-indications-complications

In this review the technique, indication for and complications of percutaneous nephrostomy (PCN) and antegrade ureter stent insertion are described. In the majority of the cases PCN is performed to relieve urinary obstruction, which can be of benign or malignant nature. Another indication for PCN is for treatment of urinary fistulas. PCN can be performed under ultrasound and/or fluoroscopic guidance, with a success rate of more than 90%. The complication rate is approximately 10% for major and minor complications together and 4-5% for major complications only. Percutaneous antegrade double-J stent insertion usually is performed if retrograde ureter stenting has not been successful. However, especially in malignant obstructions, the success rate for antegrade stenting is higher than for retrograde transvesical double-J stent insertion. In the case of severe infection and bleeding after PCN JJ-stent insertion may be contraindicated so long as there is no sufficient concomitant drainage via a PCN . Lower urinary tract dysfunction should be excluded before stent placement. The complication rate is 2-4%. Consequent stent surveillance with regular stent exchange is mandatory.

Complications of Renal Trauma

Renal trauma is rare, and significant complications from renal trauma are generally rarer still occurring in less than 5% in modern series. Close follow-up of injured patients and scrupulous use of imaging, including computed tomography scan, arteriogram, or retro-grade pyelogram when appropriate, increase detection rates and establish the diagnosis in most patients. Treatment varies by etiology and may range from watchful waiting to percutaneous drainage to, in rare cases, nephrectomy.

Renal artery pseudoaneurysm after laparoscopic partial nephrectomy

Delayed bleeding from a renal artery pseudoaneurysm is a rare occurrence after partial nephrectomy. We present 2 cases of renal artery pseudoaneurysm after laparoscopic partial nephrectomy. One patient presented with gross hematuria and flank pain and the other presented with flank pain and a decreasing hematocrit. The patients were treated with selective angioembolization of the pseudoaneurysm. The etiology and management of this potentially life-threatening condition are discussed.