Renal Stenting Research Articles

Left Renal Vein Stenting in Nutcracker Syndrome: Outcomes and Implications

Nutcracker syndrome refers to the symptomatic extrinsic compression of the left renal vein presenting most commonly as flank pain and haematuria. While surgery remains the first-line treatment, stenting is gaining more acceptance and there are now several published case series. This article highlights the outcomes of left renal vein stenting in the setting of nutcracker syndrome.

Renal Stent Complications and Impact on Renal Function after Standard Fenestrated Endovascular Aneurysm Repair

To report renal outcomes including long-term patency, secondary interventions, and related renal function after fenestrated endovascular aortic repair (fEVAR). Single-center retrospective review of patients undergoing fEVAR between 2012 and 2018 using the Cook ZFEN device. Renal stent complications, defined as any stenosis, occlusion, kink, renal stent-related endoleak, and reinterventions were tabulated. Estimated glomerular filtration rate (eGFR) was estimated using the Modification of Diet in Renal Disease formula. During the study period, 114 patients underwent elective fEVAR. Of 329 total target vessels, 193 renal arteries were stented (133 Atrium iCAST, 60 Gore VBX). Technical success was achieved in 97.4%, and the mean follow-up was 23.3months. Seventeen renal complications occurred in 14 patients (12.3%), including 4 occlusions, 9 stenosis, 3 dislocations, and 1 type III endoleak. All stent complications underwent endovascular reintervention with a median hospital stay of 1day (0-10) and a technical success of 94.2%. One patient suffered renal hemorrhage that warranted embolization. Patients with occlusion were treated the day of diagnosis, and mean time from diagnosis to intervention for stenosis was 21.5days. Estimated primary patency was 92.1 % and 81.5% at 24 and 48months, respectively. On multivariate analysis, larger native renal artery diameter was the only independent protective factor against patency loss (HR 0.23 (0.09-0.59)). Secondary patency at latest follow-up was 99.4%. Mean eGFR was not significantly different at latest follow-up between patients with renal complications versus those without (43.75 vs. 55.58mL/min/1.73m2, P=0.09). Comparing patients with and without renal stent complications, 81.4% and 72.7% of patients had stable or improved renal disease by chronic kidney disease staging compared with baseline (P=0.51). fEVAR is a durable option for the treatment of juxtarenal aortic aneurysms and is associated with excellent secondary patency. Renal stent complications have no significant impact on renal function, but smaller native renal arteries are at higher risk of stent-graft complications.

Manejo endovascular de la estenosis de la arteria renal en el trasplante renal

INTRODUCCIÓN: La estenosis de la arteria renal es la complicación vascular más frecuente del trasplante renal y una de las principales causas de pérdida del injerto y muerte prematura en los pacientes trasplantados. A pesar de ser potencialmente tratable, es frecuentemente infradiagnosticada, por lo que su diagnóstico precoz y manejo terapéutico adecuado resulta fundamental para evitar la pérdida de función renal. MATERIAL Y MÉTODOS: Analizamos retrospectivamente el caso de dos pacientes de 72 años trasplantados en nuestro centro en 2017. Ambos pacientes, con antecedentes de hipertensión arterial, cardiopatía isquémica crónica y enfermedad renal crónica terminal secundaria a nefroangioesclerosis y glomerulonefritis membranosa, respectivamente; presentaron un empeoramiento de la creatinina en el postoperatorio inmediato del trasplante renal. Ante este hallazgo y la evidencia de velocidades pico sistólicas >200 cm/s en la ecografía-doppler se sospechó una estenosis de la arteria del injerto, posteriormente confirmada con angiografía y angio-TC, respectivamente. Por lo que se realizó una revascularización percutánea e implante de stent. RESULTADOS: Se realizó la angioplastia con balón y colocación de stent, bajo anestesia local, obteniendo un buen resultado morfológico, sin complicaciones inmediatas. Tras el procedimiento ambos pacientes presentaron una mejoría progresiva de la función renal manteniendo un buen ritmo de diuresis, siendo dados de alta a los 8 y 11 días del mismo. Desde entonces, la función renal de ambos pacientes se ha mantenido estable presentando a los 12 meses un filtrado glomerular alrededor de 67 mL/min/1.73m2 y 60 mL/min/1.73m2, respectivamente. Sin evidencia de complicaciones tras 14 meses del procedimiento. CONCLUSIONES: La angioplastia con balón y colocación de stent en la estenosis de la arteria renal en el trasplante es una técnica segura y efectiva. Sin embargo, es necesaria una elevada experiencia para disminuir el número de complicaciones y optimizar los resultados de esta técnica. Palabras clave: trasplante renal, estenosis arterial, manejo mínimamente invasivo, cirugía endovascular.

Emergent Chimney Endovascular Repair of an Aortoenteric Fistula in the Setting of a Solitary Kidney

Open surgery remains the definitive therapy for secondary aortoenteric fistula, but mortality is as high as 40%. Endovascular repair has emerged as a viable option, particularly in the critically ill. We present a case of an emergent chimney endovascular repair of a juxtarenal secondary aortocolonic fistula complicated by septic and hemorrhagic shock in a patient with a solitary kidney. A 68-year-old morbidly obese man with a history of myocardial infarction, peripheral artery disease, and a solitary kidney (prior kidney donation to wife) underwent an open tube graft repair of a ruptured abdominal aortic aneurysm at an outside facility. His recovery was complicated by a large proximal anastomotic pseudoaneurysm with an aortocolonic fistula. On postoperative day 30, he was transferred to our institution for worsening hemodynamic status and evolving sepsis. Shortly after arrival, superimposed hemorrhagic shock developed after 1 L of lower gastrointestinal bleed. Imaging had demonstrated a fistula at the level of the left renal artery ostium with a broad-based communication with the mid-transverse colon (Fig, A). Given the patient’s acutely deteriorating clinical status and hostile anatomy, we decided to pursue the least invasive treatment option. A left renal artery chimney stent graft was delivered through the left brachial artery while an Endurant II (Medtronic, Santa Rosa, Calif) proximal aortic cuff was deployed to promptly seal the fistula. To exclude the entire tube graft from the systemic circulation, to avoid the need for contralateral gate cannulation, and to concomitantly address bilateral iliac occlusive disease, the AFX platform (Endologix, Irvine, Calif) was deployed with adequate overlap with the proximal cuff (Fig, B and C). The patient then underwent laparotomy for an extended left hemicolectomy and transverse colostomy. We noted prompt postoperative improvement in sepsis and hemodynamic status. Serial postoperative imaging up to 9 months has shown near-resolution of periaortic inflammatory changes and widely patent aortic and left renal artery repairs. Suppressive oral antibiotics are maintained. Chimney endovascular aortic repair is a viable option for emergent repair of secondary aortoenteric fistula in a select group of high-risk patients.

Revascularization of occluded renal artery stent grafts after complex endovascular aortic repair and its impact on renal function

BackgroundAcute occlusion of renal bridging stent grafts after fenestrated/branched endovascular aortic repair (F/B-EVAR) is an acknowledged complication with high morbidity that often results in chronic dialysis dependence. The feasibility and effect of timely or late (≥6 hours of ischemia) renal artery revascularization has not been adequately reported. MethodsWe performed a retrospective, multicenter study across 11 tertiary institutions of all consecutive patients who had undergone revascularization of renal artery stent graft occlusions after complex EVAR. The end points were technical success, association between ischemia time and renal function salvage, interventional complications, mortality, and mid-term outcomes. ResultsFrom 2009 to 2019, 38 patients with 46 target vessels (TVs; eight bilateral occlusions) were treated for renal artery occlusions after complex EVAR (mean age, 63.5 ± 10 years; 63.2% male). Six patients had a solitary kidney (15.8%). Of the 38 patients, 16 (42.1%) had undergone FEVAR and 22 (57.9%) had undergone BEVAR. The technical success rate was 95.7% (44 of 46 TVs). The recanalization technique used was sole aspiration thrombectomy in 5.3%, aspiration thrombectomy and stent graft relining in 52.6%, and sole stent graft relining in 36.8%. The median renal ischemia time was 27.5 hours (range, 4-720 hours; interquartile range, 4-36 hours). Most patients (94.4%) had been treated after ≥6 hours of renal ischemia time, and 55.6% had been treated after 24 hours. In 14 patients (36.8%), renal function had improved after intervention (mean glomerular filtration rate improvement, 14.2 ± 9 mL/min/1.73 m2). However, 24 patients (63.2%) showed no improvement. Improvement of renal function did not correlate with the length of renal ischemia time. Of the 14 patients with bilateral renal artery occlusion or a solitary kidney, 9 experienced partial recovery of renal function and no longer required hemodialysis. In-hospital mortality was 2.6%. The cause of renal stent graft occlusion could not be identified in 50% of the TVs (23 of 46). However, in 19 (41.3%), significant stenosis or a kink of the renal stent graft was found. The median follow-up was 11 months (interquartile range, 0-28 months). The estimated 1-year patient survival and patency rate of the renal stent grafts was 97.4% and 83.8%, respectively. ConclusionsRevascularization of occluded renal bridging stent grafts after F/B-EVAR is a safe and feasible technique and can lead to significant improvement of renal function, even after long ischemia times (>24 hours) of the renal parenchyma or bilateral occlusion, as long as residual perfusion of the renal parenchyma has been preserved. Also, the long-term patency rates justify aggressive management of renal artery occlusion after F/B-EVAR.

Final 5-year results of the United States Zenith Fenestrated prospective multicenter study for juxtarenal abdominal aortic aneurysms

PurposeTo report 5-year results of the prospective, multicenter study designed to evaluate the Zenith Fenestrated AAA Endovascular Graft (William A. Cook Australia, Brisbane, Australia) for juxtarenal abdominal aortic aneurysms (AAAs). MethodsSixty-seven patients (54 male, mean age 74 ± 8 years) were prospectively enrolled at 14 U.S. centers from 2005 to 2012. Fenestrated stent grafts were used in patients with infrarenal aortic neck lengths of 4 to 14 mm to target 178 renal-mesenteric arteries with a mean of 2.7 vessels per patient. At 5 years, 42 of the 67 patients completed the final study follow-up, with clinical examination obtained in 41 and computed tomography imaging in 39. Outcomes adjudicated by a clinical events committee included all-cause and aneurysm-related mortality, major adverse events, renal stent occlusion/stenosis, renal function changes and renal infarcts, aneurysm sac enlargement (>5 mm), device migration (≥10 mm), type I/III endoleak, and secondary interventions. ResultsMedian follow-up was 59.8 months (range, 0.1-67.5 months). There were seven deaths, including one (1.5%) within 30 days (procedure-related) and six beyond 30 days (not procedure-related in five, indeterminate in one). At 5 years, freedom from all-cause mortality was 88.8 ± 4.2% and freedom from aneurysm-related mortality was 96.8 ± 2.3%. There were no aneurysm ruptures or conversions to open surgery. Of the 129 renal arteries targeted by fenestrations, five (4%) occluded and 14 (11%) developed in-stent stenosis. Treatment included redo stenting/angioplasty in 13 vessels, renal artery bypass in 2 vessels, and failed thrombectomy in 1 vessel. Primary and secondary renal target patency was 82.7 ± 4.1% and 95.7 ± 2.1% at 5 years, respectively. Dialysis was required in one patient who had pre-existing chronic kidney disease. During the 5 years, there was 1 type IA endoleak (1.5%), 1 type IB endoleak (1.5%), 2 device migrations (3%), and 4 aneurysm sac enlargements (6%). Overall, 81% of patients had sac shrinkage at 5 years. Of 20 patients who underwent secondary interventions, 12 were for renal in-stent stenosis or occlusion, 7 were for endoleak, and 1 was for both indications. Freedom from secondary intervention was 63.5 ± 7.2% at 5 years. ConclusionsThese 5-year results confirm the safety and effectiveness of the Zenith Fenestrated AAA stent graft with no late graft- or aneurysm-related deaths. In-stent stenosis of bare metal renal stents was the most frequent indication for secondary intervention. The low rate of type IA endoleak, sac enlargement, and device migration support its use in patients with juxtarenal AAAs.

Renal Artery Outcomes After Open Repair of Suprarenal or Type IV Thoraco-abdominal Aortic Aneurysms

The aim of this study was to evaluate the mid and long term patency of elective renal artery reconstructions during open surgical repair of suprarenal aortic aneurysms (SRAA) and type 4 thoraco-abdominal aortic aneurysms (T4AAA). This retrospective, single centre study included all consecutive patients who underwent surgery for SRAA or T4AAA between January 2009 and December 2019at Toulouse University Hospital. All patients underwent strict pre-operative planning with computed tomography angiography (CTA) and 3D reconstruction of the aortic aneurysm, visceral and renal artery anatomy to choose the most appropriate surgical technique for each case. Primary patency, primary assisted patency, and rates of re-intervention were calculated using the Kaplan-Meier method. In total, 103 patients, having undergone 159 renal artery revascularisation procedures, were enrolled in the study. Fifty-five patients presented with a type T4AAA and 48 patients with a SRAA. In hospital mortality was 2.9%. In association with aortic surgery, 100 direct re-implantation (62.8%), 48 retrograde bypasses (30.1%), and 11 anterograde bypasses (6.9%) of the renal arteries were performed. Median follow up was 45.9±36 months. Renal artery primary patency rates were 99.4%, 96.4%, and 93.1% at one, three, and five years, respectively. Assisted primary patency rates were 99.4%, 97.7%, and 97.7% at one, three, and five years, respectively, with five cases of renal stenosis > 70% successfully treated by renal stenting. No significant difference in patency was found regarding the type of renal revascularisation. This retrospective study suggests that the mid term patency of elective open renal artery reconstruction during SRAA and type T4AAA surgery preceded by pre-operative planning with 3D-CTA reconstruction, yields excellent outcomes whatever the technique used.

Long-term Results of Renal Artery Patency in Physician-modified Endografts for Juxtarenal Aneurysms

Renal artery stents are commonly placed in physician-modified fenestrated endografts for juxtarenal aortic aneurysms, but long-term outcomes of these stents is unknown. The purpose of this study was to identify the long-term outcome of stented renal arteries in patients who undergo a physician-modified endovascular graft (PMEG) for repair of juxtarenal aortic aneurysms. Data were prospectively collected on patients treated with PMEG from August 2011 to September 2019 in a prospective, consecutively enrolling investigational device exemption clinical trial (NCT #01538056). Anatomic criteria, including native renal artery stenosis and angulation, were systematically measured using preoperative computed tomography. The primary outcome of renal artery reintervention after PMEG was assessed with Kaplan-Meier survival estimation. Cox proportional hazard models were used to predict renal artery reintervention after PMEG, adjusting for preoperative demographic and patient risk factors, antiplatelet use prestent and poststent placement, and evidence of preoperative stenosis by duplex criteria. We studied 141 patients who underwent PMEG during the study period, representing 282 renal arteries. During the study period, 246 out of 282 (87%) renal arteries were stented. Inability to cannulate the renal artery as the most common cause (n = 9) of inability to stent the artery. However in 25% (n = 9) of these situations, the renal artery was preserved and in 25% (n = 9) an effective proximal seal zone was obtained without renal stenting. Preoperative ostial stenosis was present in 23% (n = 62) of renal arteries by diameter reduction and 22% (n = 58) by duplex criteria. Over a follow-up period of 5 years, 15 renal arteries in 13 patients required reintervention, for an overall reintervention rate of 6.1%. All stented renal arteries remained patent. Median follow-up was 2 years (interquartile range, 0.5-4 years). The most common cause for reintervention during the first 6 months was failure to cannulate during the initial PMEG (15%, n = 2). In-stent restenosis was the reason for reinterventions for 30% (n = 4). Long-term follow-up revealed stent separation (15%, n = 2) and type IIIc endoleak (15%, n = 2) as the most common cause for reintervention. The predicted reintervention free survival of the renal artery at 5 years is 90% (95% confidence interval, 82%-95%) (Figure). Using a Cox proportional hazard model, no significant anatomic or patient-based predictors of reintervention were identified. Renal artery stents placed during physician-modified endografts show excellent long-term durability with a low rate of reintervention. No preoperative renal artery measurements are predictive of either renal stent patency or reintervention.

Comparison of Renal Artery Bridging Stents During Fenestrated Endovascular Aneurysm Repair

Fenestrated endovascular aneurysm repair (FEVAR) has expanded treatment options for complex abdominal aortic aneurysms. Viabahn balloon-expandable stent grafts (VBX; W. L. Gore & Associates, Flagstaff, Ariz) may provide a more flexible bridging stent alternative than traditional iCAST stent grafts (Maquet, Rastatt, Germany). The purpose of this study was to compare VBX with iCAST when used as renal artery bridging stents during FEVAR.

Patient-Specific Computational Flow Modelling for Assessing Hemodynamic Changes Following Fenestrated Endovascular Aneurysm Repair

Abstract Objective This study aimed to develop an accessible patient-specific computational flow modelling pipeline for evaluating the hemodynamic performance of fenestrated endovascular aneurysm repair (fEVAR), with the hypothesis that computational flow modelling can detect aortic branch hemodynamic changes associated with fEVAR graft implantation. Methods Patients who underwent fEVAR for juxtarenal aortic aneurysms with the Cook ZFEN were retrospectively selected. Using open-source SimVascular software, preoperative and postoperative visceral aortic anatomy was manually segmented from computed tomography angiograms. Three-dimensional geometric models were then discretized into tetrahedral finite element meshes. Patient-specific pulsatile in-flow conditions were derived from known supraceliac aortic flow waveforms and adjusted for patient body surface area, average resting heart rate, and blood pressure. Outlet boundary conditions consisted of three-element Windkessel models approximated from physiologic flow splits. Rigid wall flow simulations were then performed on preoperative and postoperative models with the same inflow and outflow conditions. We used SimVascular's incompressible Navier-Stokes solver to perform blood flow simulations on a cluster using 72 cores. Results Preoperative and postoperative flow simulations were performed for 10 patients undergoing fEVAR with a total of 30 target vessels (20 renal stents, 10 mesenteric scallops). Postoperative models required a higher mean number of mesh elements to reach mesh convergence (3.2 ± 1.8 × 106 vs 2.6 ± 1.1 × 106; P = .005) with a longer mean computational time (10.3 ± 6.3 hours vs 7.8 ± 3.5 hours; P = .04) compared with preoperative models. fEVAR was associated with small but statistically significant increases in mean peak proximal aortic arterial pressure (140.3 ± 11.0 mm Hg vs 136.9 ± 8.7 mm Hg; P = .02) and peak renal artery pressure (131.6 ± 14.8 mm Hg vs 128.9 ± 11.8 mm Hg; P = .04) compared with preoperative simulations. No differences were observed in peak pressure in the celiac, superior mesenteric, or distal aortic arteries (P = .17-.96). When measuring blood flow, the only observed difference was an increase in peak renal flow rate after fEVAR (17.5 ± 3.8 mL/s vs 16.9 ± 3.5 mL/s; P = .04). fEVAR was not associated with changes in the mean pressure or the mean flow rate in the celiac, superior mesenteric, or renal arteries (P = .06-.98). Stenting of the renal arteries did not induce significant changes time-averaged wall shear stress in the proximal renal artery (23.4 ± 8.1 dynes/cm2 vs 23.2 ± 8.4 dynes/cm2; P = .98) or distal renal artery (32.7 ± 13.9 dynes/cm2 vs 29.6 ± 11.8 dynes/cm2; P = .23). In addition, computational visualization of cross-sectional velocity profiles revealed low flow disturbances associated with protrusion of renal graft fabric into the aortic lumen. Conclusions In a pilot study involving a selective cohort of patients who underwent uncomplicated fEVAR, patient-specific flow modelling was a feasible method for assessing the hemodynamic performance of various two-vessel fenestrated device configurations and revealed subtle differences in computationally derived peak branch pressure and blood flow rates. Structural changes in aortic flow geometry after fEVAR do not seem to affect computationally estimated renovisceral branch perfusion or wall shear stress adversely. Additional studies with invasive angiography or phase contrast magnetic resonance imaging are required to clinically validate these findings. (JVS–Vascular Science 2021;▪:1-17.) Clinical Relevance Using a computational flow modelling for assessing the hemodynamic performance of fenestrated endovascular aneurysm repair (fEVAR), this real-world, patient-specific study included 10 participants and found that structural changes in aortic flow geometry after fEVAR did not seem to adversely impact estimated renal or visceral branch perfusion metrics (eg, peak and mean arterial pressure and flow rates) or wall shear stress. These findings overall support the ongoing clinical use of commercially available fEVAR devices for repair of juxtarenal aortic aneurysms, and provides a computational framework for future evaluation of fEVAR configurations in a preoperative or postoperative settings.

Contrast-Enhanced Ultrasound Evaluation of Renal Blood Perfusion Changes After Percutaneous Transluminal Renal Angioplasty and Stenting for Severe Atherosclerotic Renal Artery Stenosis

This study used contrast-enhanced ultrasound (CEUS) to evaluate changes in renal cortical blood perfusion after percutaneous transluminal renal angioplasty and stenting (PTRAS) for severe renal artery stenosis (RAS) (≥70%). CEUS was performed in 21 patients with 24 severe RASs that underwent PTRAS. Renal cortical perfusion was quantitatively evaluated by comparing time intensity curve (TIC) parameters for SonoVue (Bracco, Milan, Italy) contrast enhancement, including peak intensity (PI), time to peak (TTP), mean transmit time (MTT), curve ascending slope (S), area under the curve (AUC), AUC-wash-in and AUC-wash-out. The parameters PI, TTP, MTT and S differed significantly between the pre-intervention and post-intervention TIC analysis (p < 0.05). Of the 24 pre-intervention curve appearances, 58.3% (14/24) improved after operation. The PI difference correlated positively with the estimated glomerular filtration rate difference (r = 0.433, p < 0.05). In conclusion, changes in some ultrasound perfusion parameters on CEUS and the shape of the TIC can be used to quantitatively and intuitively evaluate renal cortical blood perfusion change after PTRAS.

Quantification of suprarenal aortic neck dilation after fenestrated endovascular aneurysm repair

ObjectiveSuprarenal aortic neck dilation (AND) after fenestrated endovascular aneurysm repair (FEVAR) with commercially available devices has not yet been well characterized. The aim of this study was to measure diameter changes in the supravisceral aorta after FEVAR. MethodsThis is a single-center retrospective review involving patients with juxtarenal aneurysms treated with Cook ZFEN devices (Cook Medical, Bloomington, Ind). Patients with at least 1 year of cross-sectional radiologic follow-up were included. AND was defined as ≥3 mm at any measured location. Aortic diameter, defined as the average outer to outer diameter on three-dimensional centerline imaging, was measured at seven locations along the length of the ZFEN device from the proximal fixation struts to the bottom of the second seal stent. The first postoperative CT scan (≤1 month) served as a baseline from which subsequent measurements at annual intervals were compared. ResultsA total of 43 patients who underwent FEVAR from 2012 to 2018 met inclusion criteria, with a total of 119 target vessels (83 renal stents, 41 superior mesenteric artery scallops or large fenestrations). Mean follow-up time was 30.3 months. Any AND was found to occur in 32 (74.4%) patients. Aortic diameter dilation at latest follow-up was found to occur at all measured locations from the top of the fixation struts (1.9 ± 2.4 mm; P < .0001) to the middle of the second seal stent (1.3 ± 3.8 mm; P < .01). Diameter growth was most pronounced in the middle of the first seal stent, with mean AND of 3.6 ± 3.2 mm. At this location, the aorta experienced nearly linear annual growth of 0.99 mm (95% confidence interval, 0.7-1.28 mm) per year. Increasing device oversizing relative to the native visceral aorta was the strongest predictor of postoperative neck diameter growth (1.34 mm per 10% increase in oversizing; P = .02), whereas increasing proximal seal length was protective of growth (−1.82 mm per 10-mm increase in seal length; P = .016). Proximal seal lengths ≥3 cm were associated with less neck dilation compared with <3 cm (2.6 mm vs 4.9 mm; P = .022). Type IA endoleak in this cohort was rare (n = 1) and not associated with AND (P = .256). ConclusionsDilation of the suprarenal aorta is a common finding in midterm follow-up after FEVAR and not associated with proximal endoleak. Aggressive device oversizing is predictive of dilation, whereas longer seal lengths are associated with less dilation along the suprarenal seal zone. These results support the continued use of FEVAR for juxtarenal aneurysms, particularly in patients in whom ≥3 cm of healthy seal length can be obtained.

Safety and Feasibility of Performing Fenestrated Endovascular Abdominal Aneurysm Repair Using a Portable C-arm Without Fusion Technology: A Single-Center Experience.

ObjectiveMost centers performing fenestrated endovascular aneurysm repair (F-EVAR) use hybrid rooms with fusion technology for mapping. We present our experience of successfully performing F-EVAR using C-arm without fusion technology.MethodsDuring the period of January 2016 to October 2018, data were collected from a prospectively maintained F-EVAR database at our tertiary care institute. The primary endpoint was technical success, and the secondary outcomes measured were short- and midterm clinical success (both defined by the Society for Vascular Surgery reporting standards), blood loss, radiation dose, operative time, postoperative endoleaks, aneurysm rupture, endograft patency, and complications.ResultsWe performed 11 F-EVARs during the study period in five (45.5%) males and six (54.5%) females, with a mean age of 75+8 years. All procedures were performed under general anesthesia using OEC 9900 Elite Mobile C-arm (GE Healthcare, Chicago, IL, USA) without the use of fusion technology. Three patients had planned preoperative open procedures for access due to prior cutdown or bypass. Technical success was achieved in all 11 (100%) cases. The mean length of stay was 5+2 days, and the mean follow-up was 7.5+6.5 months. The mean procedure time was 301+167 minutes, and the mean blood loss was 361+233 mL. Mean fluoroscopy time was 72+31 minutes, and the mean radiation exposure time was 2,160+930 mGy. No patients required intraoperative transfusion. Thirty-day (short term) clinical success was achieved in 10 (90.0%), cases whereas six-month (midterm) clinical success was achieved in 7 (77.7%) patients. Branch vessel patency was 11 (100%) at 30 days and 9 (81.8%) at six months, and primary endograft patency was 100% (11) at six months. We had no perioperative mortality or major adverse cardiac event at 30 days. Thirty-day postoperative morbidity included readmission for pulmonary edema from cardiac failure in one patient. Two patients had clinically insignificant silent cardiac enzyme elevation. Three patients had re-interventions performed during the mean follow-up period. Two patients developed renal stent thrombosis resulting in renal insufficiency, which is defined as an increase in creatinine concentration ≥0.5 mg/dL, without the need for dialysis. One type II endoleak was identified postoperatively that required trans-lumbar embolization. No type I or III endoleaks were identified during the study period. Asymptomatic common femoral artery thrombosis was seen on follow-up imaging in one patient.ConclusionsWe conclude that F-EVAR can be safely performed using C-arm without the use of fusion technology. Its utility can be expanded to centers with appropriate skill set but no hybrid technology

V05-02 ROBOTIC ASSISTED LAPAROSCOPIC PLACEMENT OF EXTRAVASCULAR STENT FOR NUTCRACKER SYNDROME

You have accessJournal of UrologyUpper-Tract Reconstruction (V05)1 Apr 2020V05-02 ROBOTIC ASSISTED LAPAROSCOPIC PLACEMENT OF EXTRAVASCULAR STENT FOR NUTCRACKER SYNDROME Buddima Ranasinghe*, Sohrab Arora, Amit Patel, Judith Lin, and Craig Rogers Buddima Ranasinghe*Buddima Ranasinghe* More articles by this author , Sohrab AroraSohrab Arora More articles by this author , Amit PatelAmit Patel More articles by this author , Judith LinJudith Lin More articles by this author , and Craig RogersCraig Rogers More articles by this author View All Author Informationhttps://doi.org/10.1097/JU.0000000000000874.02AboutPDF ToolsAdd to favoritesDownload CitationsTrack CitationsPermissionsReprints ShareFacebookLinked InTwitterEmail Abstract INTRODUCTION AND OBJECTIVE: Renal nutcracker syndrome (NCS) is a venous entrapment caused by compression of the left renal vein (LRV) between the aorta and superior mesenteric artery (SMA). Surgical options for treatment of NCS include LRV transposition, gonadal vein transposition, renocaval bypass, and renal autotransplantation. Endovascular left renal vein stenting may lead to stent migration and fracture. Thus, we present an alternative, unique, minimally invasive treatment option. METHODS: A 20-year-old man presents with intermittent, debilitating left flank pain for 6 months. He developed an episode of gross hematuria without hypertension, oliguria, dysuria, or fever. CT venogram showed compression of the LRV between the aorta and SMA with an acute, aortomesenteric angle of 25 degrees. Venogram with pressure measurement showed a gradient of 3 mmHg across the compression. Intravascular ultrasound showed 94.4% luminal compression of the LRV. After discussion of all surgical and endovascular options, the patient decided to proceed with robotic-assisted laparoscopic resection of fibrous ring and placement of extravascular graft. The patient was positioned with right lateral decubitus. Six ports were used via transperitoneal technique. After the retroperitoneal space was incised along the inner margin of the descending colon, the LRV was mobilized. The pancreas and the left adrenal vein was identified. Tissue surrounding the left gonadal vein was excised. The fibrous bundles were excised around the outflow end between the aorta and SMA to release the renal vein compression. An externally reinforced, expanded PTFE, 16 mm in diameter, was introduced and bound to the surface of the renal vein along the long axis to prevent blood vessel compression. The PTFE cuff was sutured and tacked to the surface of the aorta and retroperitoneal tissues. SMA was lowered and stabilized over the graft. RESULTS: The operative time was 3 hours. Estimated blood loss of 10 ml. Length of stay was 1 day with no complications. At 4-week postop visit, he was doing well with full resolution of the left flank pain. Post-op intravascular ultrasound showed patent left renal vein with no evidence of elevated flow velocities. Renal vein cuff visualized at SMA with PSV of 67 cm/sec. Left gonadal vein patent with retrograde flow noted. CONCLUSIONS: Robotic-assisted laparoscopic resection of a fibrous ring and placement of an extravascular cuff around the left renal vein is an effective, minimally invasive approach for treatment of nutcracker syndrome with no warm ischemic injury and no venous anastomosis. Magnification and stability of the dual-lens robotic camera offer excellent visibility and substantially lower blood loss compared to open surgery. Source of Funding: NONE © 2020 by American Urological Association Education and Research, Inc.FiguresReferencesRelatedDetails Volume 203Issue Supplement 4April 2020Page: e470-e470 Advertisement Copyright & Permissions© 2020 by American Urological Association Education and Research, Inc.MetricsAuthor Information Buddima Ranasinghe* More articles by this author Sohrab Arora More articles by this author Amit Patel More articles by this author Judith Lin More articles by this author Craig Rogers More articles by this author Expand All Advertisement PDF downloadLoading ...

AIUM Practice Parameter for the Performance of Duplex Sonography of Native Renal Vessels

AIUM Practice Parameter for the Performance of Duplex Sonography of Native Renal Vessels

Robotic assisted extravascular stent placement for nutcracker phenomenon of the left renal vein: a case series.

Nutcracker phenomenon of the left renal vein is a rare anatomic anomaly that can present with chronic flank/pelvic pain, pelvic congestion, and hematuria. Conventional treatment options (superior mesenteric artery transposition, endovascular stent placement, auto-transplantation) involve substantial risk, morbidity, or the need for chronic anti-coagulation. We now report our institution's robotic experience with extravascular left renal vein stent placement. A retrospective, single surgeon series from December 2016 to May 2019 was reviewed. After positioning and port placement (three robotic ports, one assistant), the left renal vein was exposed and dissected free circumferentially down to the inferior vena cava insertion. The distance between the renal vein ostium and adrenal vein was measured and a 1cm-diameter ringed polytetrafluoroethylene vascular stent of this length placed. The stent edges were secured to itself with 3-0 polyglactin sutures. Demographics, surgical, and functional outcomes were collected. Six patients with mean age of 45 ± 6years and body mass index of 20.3 ± 3.3g underwent the procedure. Mean operative time was 143 ± 20min. Estimated blood loss was minimal. Mean graft length utilized was 2.25 ± 0.3cm. Median day of discharge was 1.5days (range 1-3). No high-grade complications occurred. All patients received immediate pain relief and 50% also saw other symptomatic improvements. Robotic assisted extravascular left renal vein stent placement appears safe and effective in a small cohort with short follow-up. Further long-term follow-up for pain relief and graft-related complications are needed.

Fenestrated-branched endovascular aortic repair in patients with chronic kidney disease

ObjectiveRenal function impairment is a common complication after open repair of complex abdominal aortic aneurysms and thoracoabdominal aortic aneurysms (TAAAs). The purpose of this study was to assess renal perioperative outcomes and renal function deterioration after fenestrated-branched endovascular aneurysm repair (F/BEVAR) in patients with chronic kidney disease (CKD). MethodsThe study included 186 patients who underwent F/BEVAR between 2013 and 2018 for suprarenal, juxtarenal, and type I to type IV TAAAs. Glomerular filtration rate (GFR) was calculated using the Modification of Diet in Renal Disease (MDRD) study equation. Postoperative acute kidney injury (AKI) and CKD were defined using RIFLE criteria (Risk, Injury, Failure, Loss, and End-stage renal disease) and CKD staging system (stage ≥3, GFR <60 mL/min/1.73 m2), respectively. For those without baseline CKD, renal decline was defined as a drop in GFR <60 mL/min/1.73 m2 (ie, progression to CKD stage 3 or higher). For patients with baseline renal dysfunction, GFR decline ≥20% or progression in CKD stage (ie, from stage 3 to stage 4) was considered renal decline. ResultsCKD was present in 83 patients (44.6%). Postoperative AKI was diagnosed in 27 patients (14.5%); 13 (48.1%) had history of CKD and 14 (51.9%) had adequate renal function preoperatively (P = .8). None of these patients required permanent renal replacement therapy. Intraoperative technical success was 100%. Overall 30-day mortality was 1.1%. There was no difference in 30-day mortality in patients with (1.2%) and without (1.0%) CKD (P = .5). During a median follow-up time of 12 months (interquartile range, 6-23 months), renal decline was observed in 21 patients (25.3%) with previous CKD and in 11 patients (10.6%) without CKD (P = .01). Among patients with previous CKD, 18 patients (9%) progressed from stage 3 CKD to stage 4. In patients with progression in CKD stage, two (5%) had renal stent stenosis requiring restenting. Among patients with renal decline, 13 had juxtarenal aneurysms (21.3%), 27 had suprarenal aneurysms (44.3%), and 21 had TAAAs (34.3%; P = .4). Subset analysis of patients who developed AKI in the immediate postoperative period found that patients with a history of CKD were less likely to experience freedom from renal decline. ConclusionsF/BEVAR is an effective and safe procedure for patients with complex abdominal aortic aneurysms and TAAAs, even among patients with CKD. The frequency of AKI was not affected by pre-existing CKD. Midterm outcomes demonstrated that progression of CKD was more frequent among patients with pre-existing CKD, but permanent renal replacement therapy was not required. Anatomic extent of aneurysms did not affect CKD progression. CKD patients are susceptible to renal decline over time if they experience AKI in the postoperative period. Therefore, preventing AKI in the postoperative period should be regarded as a priority. Long-term effects of CKD after F/BEVAR remain to be elucidated.

Percutaneous coronary intervention of the large right coronary artery using a renal stent – An off-label device for an on-label indication

Percutaneous coronary intervention of large ectatic coronary arteries is always challenging for the interventional cardiologist. Large coronary arteries, also called as “dilated coronaropathy,” have heterogeneous etiology that angiographically manifests as localized or diffuse ectasia. The large caliber of the coronary artery poses many challenges such as the choice of type of the stent whether to use coronary versus noncoronary stent or drug-eluting versus bare-metal stent. Furthermore, the size of the stent and complete expansion after its deployment can be addressed using intracoronary imaging techniques such as intravascular ultrasound and optical coherence tomography in the setting of coronary artery ectasia. Different types of peripheral vascular or nonvascular stents were used for the percutaneous treatment of large native coronary arteries or saphenous vein graft lesions. We report a case, where a renal stent for a large coronary artery was used successfully to treat the clinical situation. Furthermore, we have discussed the various options of the percutaneous therapy available in the setting of large coronary arteries as described in the literature.

Alternative urgent management for iatrogenic dissection of a large left-main coronary artery: Renal stent implantation.

Alternative urgent management for iatrogenic dissection of a large left-main coronary artery: Renal stent implantation.

Feasibility of Using Fusion Techniques in the Follow Up of Complex Aneurysm Repair

Introduction - Fusion imaging is becoming standard for the endovascular treatment of complex aortic aneurysms, but its role in follow up has not been explored. A critical issue in post operative surveillance is renal functional deterioration over time. Renal volume, stent angulation and stenosis have all been used as a marker of renal impairment (1)(2), however combined assessment of these variables is not always reproducible and remains a complex and resource-intensive procedure. The aim of this study is to determine the accuracy of a fusion-based software to automatically calculate the renal volume changes during follow-up (FU) and standardise its use.