Preliminary Evaluation of Hemodynamic Effects of Fontan Palliation on Renal Artery Using Computational Fluid Dynamics

Background:The assessment of renal function is important to the prognosis of patients needing Fontan palliation due to the reconstructed compromised circulation.To know the relationship between the kidney perfusion and hemodynamic characteristics during surgical design could reduce the risk of acute kidney injury(AKI)and the postoperative complications.However,the issue is still unsolved because the current clinical evaluation methods are unable to predict the hemodynamic changes in renal artery(RA).Methods:We reconstructed a three-dimensional(3D)vascular model of a patient requiring Fontan palliation.The technique of computational fluid dynamics(CFD)was utilized to explore the changes of RA hemodynamics under different possible blood flow rates.The relationship between the kidney perfusion and hemodynamic characteristics was investigated.Results:The calculated results indicated the declined tendency of the pressure and pressure drop as the flow rate decreased.When the flow rate decreased to two-thirds of its baseline,both the pressure of left renal artery(LRA)and the pressure of right renal artery(RRA)dipped below 50%,and the pressure of RRA fell more quickly than that of LRA.Uneven distribution of WSS was observed on the trunk of RA,and the lowest WSS was found at the distal of RA.The average WSS in RA dropped to around 50%as the flow rate reached one-third of its baseline.Conclusions:As a promising approach,CFD can be utilized to quantitatively evaluate the hemodynamic characteristics of RA and contribute to offsetting the drawbacks of clinical assessments of renal function,to help realize better prognosis for the patients with Fontan palliation.

Renal function after renal artery stenting

Atherosclerotic renal artery stenosis (ARAS), a common clinical finding, is increasing in prevalence as the population ages. ARAS is seen in ～ 7% of persons over 65 years of age1 and in ～ 20% of patients at the time of coronary angiography.2 It is an important cause of chronic kidney disease and may result in 11-14% of cases of end stage renal disease.

Main Renal Artery Plus Branch Ablation in the Treatment of Resistant Hypertension with Renal Denervation

Objective:To study the safety and effi cacy of denervation of renal artery branches in the treatment of resistant hy-pertension.Methods:Sixty patients with resistant hypertension were enrolled.The patients were randomly assigned to the main renal artery plus branch ablation group or the main renal artery ablation group.The clinical data and operation-related parameters,including number of ablation points,temperature,and average energy,were recorded.Ambulatory blood pressure was taken for all patients at the baseline and at 6 months after treatment.Offi ce blood pressure was recorded before treatment and after treatment every 3 months for 2 years.Results:Sixty patients with resistant hypertension were enrolled in this study.There were 30 patients in each group.Angiography was performed after ablation.No renal artery complications,such as stenosis and dissection,occurred in the two groups.There was no signifi cant difference in age,sex,BMI,comorbid disease,and medication between the two groups(P>0.05).The number of ablation points for the main renal artery plus branch ablation group was greater than that for the main renal artery ablation group.The offi ce blood pressure and 24-hour blood pressure were signifi cantly lower 6 months after treatment than before treatment in both groups(P<0.05).Offi ce blood pressure in the main renal artery plus branch ablation group was lower than that in the main renal artery ablation group during the 3-12-month follow-up period,with a statistical difference.However,as the follow-up time increased,the difference disappeared.Conclusion:The results of this study show that main renal artery plus branch ablation is a safe interventional method,but there was no obvious advantage on long-term follow-up compared with only main renal artery ablation.

Risk factors of renal artery pseudoaneurysm following partial nephrectomy

Objective To study the risk factors of renal artery pseudoaneurysm ( RAP) following partial nephrectomy. Methods Open partial nephrectomhy was performed on a total of 464 cases of renal cell cancer from July 2003 to May 2010. Five patients ( 1. 1% ) had postoperative hem-

Response of blood pressure after percutaneous transluminal renal artery angioplasty and stenting

AIM: To evaluate the short and intermediate term out-come of percutaneous transluminal renal artery angioplasty (PTRA) and stenting particularly on blood pressure (BP) control and renal function and to evaluate predictors of poor BP response after successful PTRA and stenting. METHODS: We conducted a prospective analysis of all patients who underwent PTRA and stenting in our institute between August 2010 to September 2012. A total number of 86 patients were underwent PTRA and renal stenting. Selective angiography was done to confirm at least 70% angiographic stenosis. The predilatation done except few cases with critical stenosis, direct stenting was done in the rest of cases. All patients received aspirin 325 mg orally, and clopidogrel 300 mg orally within 24 h before the procedure. Heparin was used as the procedural anticoagulant agent. Optimal results with TIMI-Ⅲ flow obtained in all cases. Following stent placement, aspirin 150 mg orally once daily was continued for a minimum of 12 mo and clopidogrel 75 mg orally once daily for at least 4 wk. The clinical, radiological, electrocardiography, echocardiography and treatment data of all patients were recorded. The BP measurement, serum creatinine and glomerular filtration rate (GFR) were recorded before the procedure and 1 and 6 mo after PTRA. RESULTS: A total of 86 patients were included in the study. The mean age of study population was 55.87±11.85 years old and 67 (77.9%) of patients were male. There was a significant reduction in both systolic and diastolic BP at 1 mo after the procedure: 170.15±20.10 mmHg vs 146.60±17.32 mmHg and 98.38±10.55 mmHg vs 89.88±9.22 mmHg respectively (P=0.0000). The reduction in BP was constant throughout the follow-up period and was evident 6 mo after the procedure: 144.23±18.19 and 88.26±9.79 mmHg respectively (P=0.0000). However, no improvement in renal function was observed at any time during the follow-up period. After multivariate analysis, we found male sex, low GFR (<60 mL/min) and higher baseline mean BP as a poor predictors of successful outcome on BP response after PTRA and stenting. CONCLUSION: The PTRA and stenting can be considered as an effective therapeutic intervention for improving BP control with minimal effect on renal function. The male sex, higher baseline BP and low GFR are associated with poor BP response after successful PTRA and stenting.

Successful endovascular treatment of endoscopically unmanageable hemorrhage from a duodenal ulcer fed by a renal artery: A case report

A 52-year-old woman was admitted with hypovolemic shock. Emergency endoscopy revealed three hemorrhagic duodenal ulcers(all stage A1) with exposed vessels. Two ulcers were successfully treated by endoscopic clipping; however, the remaining ulcer on the posterior wall of the horizontal portion of the duodenum could not be clipped. Because her vital signs were rapidly worsening, we performed transcatheter arterial embolization(TAE) as it is less invasive than surgery. Computed tomography aortography showed that the duodenal hemorrhage was sourced from the lower branch of the right renal artery. In general, the duodenum is fed by branches from the gastroduodenal artery or superior mesenteric artery. However, this patient had three right renal arteries. The lower branch of the right renal artery at the L3 vertebral level was at the same level as the horizontal portion of the duodenum. Complete hemostasis was achieved by TAE using metallic coils and n-butyl-2-cyanoacrylate. After TAE, she recovered from the hypovolemic shock and was discharged from hospital. She has had no recurrence of the hemorrhagic duodenal ulcer for over 1 yr, and followup endoscopy showed no necrosis or stricture of the duodenum. Although she developed a small infarct of her right kidney, her renal function was satisfactory. In summary, the present case is the first reported case of hemorrhagic duodenal ulcer in which the culprit vessel was a renal artery that was successfully treated by TAE. Computed tomography aortography before TAE provides valuable information regarding the source of a duodenal hemorrhage.

Drug coated balloon angioplasty for renal artery stenosis due to Takayasu arteritis: Report of five cases

BACKGROUND Takayasu arteritis is a rare but intractable chronic disease in young female patients. Percutaneous transluminal angioplasty of the involved renal arteries has been reported;however, few studies have reported the use of drug coated balloon angioplasty in the treatment of Takayasu arteritis. We aimed to demonstrate five young female patients who presented with a history of hypertension due to Takayasu arteritis. CASE SUMMARY From April 2017 to October 2018, five female patients were diagnosed with hypertension due to Takayasu arteritis by computed tomography angiography (CTA) and laboratory tests. Four patients had a complaint of headache with or without dizziness, and one patient showed no symptom. There was no significant family or past history of hypertension or kidney disease, and the physical examinations were almost normal on admission. We performed a treatment by drug coated balloon angioplasty. Blood pressure decreased dramatically in all patients after balloon angioplasty, and the patency of treated renal artery was demonstrated with CTA over 5 months after the angioplasty procedure. CONCLUSION Drug coated balloon angioplasty is safe and effective for renal artery stenosis due to Takayasu arteritis. A prospective study with a larger sample size is necessary to further demonstrate the effectiveness of the treatment.

Effects of renal artery stenosis on realistic model of abdominalaorta and renal arteries incorporating fluid-structureinteraction and pulsatile non-Newtonian blood flow

The effects of the renal artery stenosis （RAS） on the blood flow and vessel walls are investigated. The pulsatile blood flow through an anatomically realistic model of the abdominal aorta and renal arteries reconstructed from CT-scan images is simulated, which incorporates the fluid-structure interaction （FSI）. In addition to the investigation of the RAS effects on the wall shear stress and the displacement of the vessel wall, it is determined that the RAS leads to decrease in the renal mass flow. This may cause the activation of the renin-angiotension system and results in severe hypertension.

Ex vivo revascularization of renal artery aneurysms in a patient with solitary kidney: A case report

BACKGROUND Multiple renal artery aneurysms (RAAs) involving multiple branches in a solitary kidney are rare and present a major challenge to surgeons.Ex vivo or in situ repair combined with renal artery revascularization is the classical procedure for these complicated cases,which are not suitable for endovascular repair.The choice of bypass graft remains controversial because of the risk of aneurysmal degeneration for autologous graft.CASE SUMMARY A 39-year-old female patient presented with left lumbar pain for more than 3 mo.Computed tomography angiography showed congenital absence of the right kidney and three left RAAs involving multiple distal branches.This patient met the criteria for surgical repair due to symptoms of threatened rupture.According to the anatomy and location of multiple RAAs,ex vivo revascularization with saphenous vein graft (SVG) was performed.At the 3-year follow-up,computed tomography angiography demonstrated the aneurysmal degeneration of the Yshaped SVG.The patient remained asymptomatic and follow-up ultrasound showed no continuous growth of SVG aneurysm.CONCLUSION SVG aneurysm in RAA revascularization causes us to reflect on the choice of graft,especially for solitary kidney patients.

Laparoscopic Partial Nephrectomy With Segmental Renal Artery Clamping:Technique and Clinical Outcomes

Background:Warm ischemic injury is one of the most important factors affecting renal function in partial nephrectomy(PN).The technique of segmental renal artery clamping emerges as an alternative to conventional renal artery clamping for renal hilar control.Objective:To evaluate the feasibility and efficiency of laparoscopic PN(LPN) with segmental renal artery clamping in comparison with the conventional technique.Design,setting,and participants:A total of 75 patients underwent LPN from June 2007 to November 2009.All patients had T1a or T1b tumor in one kidney and a normal contralateral kidney.Thirty-seven patients underwent surgeries with main renal artery clamping,and 38 underwent surgeries with segmental artery clamping.Intervention:All procedures were performed by the same laparoscopic surgeon.Measurements:Blood loss,operation time,warm ischemia(WI) time,and complications affected renal function before and after operation were recorded.Results and limitations:All LPNs were completed without conversion to open surgery or nephrectomy.The novel technique slightly increased WI time(p < 0.001) and intraoperative blood loss(p = 0.006),while it provided better postoperative affected renal function(p < 0.001) compared with the conventional technique.The total complication rate was 12%.Among the 38 cases where segmental renal artery clamping was performed,7 had to convert to the conventional method.Tumor size and location influenced the number of clamped segmental arteries.Long-term postoperative renal function is still awaited.Conclusions:LPN with segmental artery clamping is safe and feasible in clinical practice.It minimizes the intraoperative WI injury and improves early postoperative affected renal function compared with main renal artery clamping.(C) 2010 European Association of Urology.Published by Elsevier B.V.All rights reserved.

Retrieval of dislodged coronary stent from left renal artery by gooseneck snare

A rapamycin-eluting stent was dislodged during attempt of implantation at the proximal right coronary artery,which was found by fluoroscopy to have migrated into the anterior trunk of the left renal artery.We chose a 5 mm diameter Amplatz gooseneck snare and successfully retrieved the lost stent from the lodging vessel.

Terutroban, a TP receptor antagonist, restores renal artery tone, but not renal function in mouse with 5/6 nephrectomy

Aim Thromboxane A2（TXA2） is assumed to contribute to the process of renal dysfunction. The pres- ent study was designed to investigate whether terutroban, a specific antagonist of thromboxane/prostaglandin？ （TP） receptor, protects against renal damage in 5/6 nephrectomy. Methods C57/BL6 mice were randomly grouped into sham-operated （2K）, 5/6 nephroectomy groups （5/6K-off） and 5/6 nephroectomy treated with ter- utroban （10 mg · kg^-1 · d^-l） groups （Yerutroban）. Renal artery and kidney were collected for vascular function study, Western blot, immunohistochemistry （IHC） assay and enzyme-linked immunosorbent assay （ELISA）, re- spectively. Results Four weeks after the surgery, arterial blood pressure was comparable among the three groups. However mice in terutroban group had higher levels of serum creatinine and lower survival. Compared with 2K groups, 5/6K-off mice had significantly higher levels of renal blood flow as well as a blunted relaxation to acetyl- choline. Production of prostacyclin （PGI2） and thromboxane B2 （ TXB2）, but no prostaglandin E2 （ PGE2）, were significantly increased in the renal artery of 5/6K-off group. Terutroban restored the renal blood flow, but not the acetylcholine-induced relaxation in the renal artery. It is probably due to the blockade effect of terutroban on the smooth muscle since terutroban treatment significantly reduced U46619-induced vasconstriction in renal arteries. Interestingly, terutroban increased the production of TXB2, but not PGI2 or PGE2, in the renal artery. This proba-bly is a compensatory effect on prostaglandins production. In kidney cortex, 5/6K-off group had significantly lower levels of PGE2 and TXB2 when compared with 2 K group. Terutroban markedly increased all three prostaglandins levels. Conclusion Terutroban restores renal artery function, but not renal function in mouse with 5/6 nephrecto- my. It suggests that kidney has more complicated regulations than renal artery. High levels of prostanoids in kid- neys may contribute to renal damage in terutroban group. Further experiments will focus on examining the underly- ing mechanisms.

Rotarex mechanical thrombectomy in renal artery thrombosis:A case report

BACKGROUND Acute renal artery thrombosis is a relatively rare disease.Early diagnosis and emergent treatment can prevent the loss of renal function and the development of hypertension.CASE SUMMARY We report a patient with acute renal artery thrombosis who presented to our hospital with acute-onset right flank pain and was treated by percutaneous mechanical thrombectomy using the Rotarex device.After 2 mo,right kidney function had recovered slightly.CONCLUSION Renal artery thrombosis may lead to loss of renal function and the development of hypertension.Rotarex mechanical thrombectomy may be a viable treatment option for rapid recanalization of the renal artery in patients with renal artery thrombosis.

Optical coherence tomography-guided percutaneous transluminal angioplasty in renal artery fibromuscular dysplasia

A 40-year-old woman was referred for resistant hypertension despite three anti-hypertensive medications including a diuretic at maximum tolerated dose.She has no family history of fibromuscular dysplasia(FMD).Contrast-enhanced computed tomography showed right renal artery stenosis suspicious of FMD.

Early Surgical Correction of Transplant Renal Artery Stenosis (Tras)—A Case Report

Saphenous vein graft (SVG) bypass of the renal artery from the aorta has been well documented, though bypass of the internal iliac artery to the individual renal arteries is not yet described. We herewith present a case of early TRAS detected 6 hours after a successful renal transplant. Renal angiography showed complete stenosis of the internal iliac to renal artery anastomosis. Percutaneous transplant artery angioplasty was attempted, but was not successful;hence the surgical correction of the same was done. This is to demonstrate the use of saphenous vein bypass of anastomotic obstruction of the previous anastomosis, in case of short renal artery.

Treatment of transplant renal artery pseudoaneurysm using expandable hydrogel coils: A case report and review of literature

Transplant renal artery(TRA) pseudoaneurysm can result in bleeding, infection, graft dysfunction and graft loss. We report the management of a renal transplant recipient who presented five months after renal transplantation with deterioration of renal function, who was found to have TRA pseudoaneurysm and TRA stenosis. Both were treated radiologically by using expandable hydrogel coils(EHC) in combination with stenting. Improvement in clinical, biochemical and radiological parameters were observed after the intervention. To our knowledge, this is the first report in the transplant literature on the use of EHC for the treatment of a TRA pseudoaneurysm.

Endovascular Repair for Abdominal Aortic Aneurysm with an Ectopic Pelvic Kidney: Case Report and Procedural Consideration of the Aberrant Renal Artery

A 91-year-old female presented with a pulsatile abdominal mass. Her past medical history included hypertension and hyperlipidemia. A 6.9 cm infrarenal abdominal aortic aneurysm, with a left ectopic pelvic kidney and two aberrant renal arteries, one each from the left and right common iliac arteries was found on computed tomography. Because of the high risk of rupture, surgery was recommended and an endovascular aneurysm repair was performed. The antegrade flow of the aberrant renal artery from the left common iliac artery was preserved. The right aberrant renal artery was covered with stent graft. The patient’s serum creatinine level remained unchanged throughout the postoperative course, with an uneventful postoperative recovery.

Common trunk of the right accessory renal artery and right inferior phrenic artery originating from the thoracic artery:An unreported variation

Accessory renal arteries(ARAs)are common and usually originate from the abdominal aorta and the renal artery.Inferior phrenic arteries(IPAs)can also arise from the abdominal aorta or its branches.In this paper,we present the first case of a common trunk of the right ARA and right IPA arising from the thoracic artery at the level of T10,which was discovered by multidetector-row computed tomography in pretherapeutic evaluation and clearly confirmed by selective angiography.It is important to recognize this anatomical variation when performing cardiovascular and interventional radiological procedures.

Endovascular treatment of traumatic renal artery pseudoaneurysm with a Stanford type A intramural haematoma:A case report

BACKGROUND Aortic intramural hematoma(IMH) associated with aortic branch tear and intramurally located pseudoaneurysm after blunt trauma has not been reported.Here,we report a case of progressive type A aortic IMH associated with a pseudoaneurysm arising from the injured proximal renal artery after blunt trauma.CASE SUMMARY During logging operations,a 66-year-old man experienced blunt force trauma after being injured by a fallen tree.He arrived at our trauma center with a left flank pain complaint.Computed tomography(CT) revealed a pseudoaneurysm arising from the proximal renal artery(localized within the aortic media) and Stanford type A IMH.A covered stent was deployed along the left main renal artery,bridging the pseudoaneurysm and covering the parent artery,successfully excluding the pseudoaneurysm as confirmed using aortography.However,although the degree of the pseudoaneurysm decreased,follow-up CT revealed remnant pseudoaneurysm,likely caused by an endoleak.Subsequently,a covered stent was additionally installed through the previously deployed covered stent.Successful exclusion of the pseudoaneurysm was confirmed using final aortography.In the 7-mo follow-up CT scan,the IMH and pseudoaneurysm completely disappeared with no evidence of stent-related complications.CONCLUSION Endovascular treatment such as stent-graft placement can be an effective and safe treatment for traumatic renal artery injury.

Giant Calcified Renal Artery Aneurysm: Traditional RX versus Three-Dimensional Computed Tomography

A 65-year-old woman with no history of previous flank trauma, renal stone or upper urinary tract infections, presented for flank pain and left hydro-uretero-nephrosis seven days after hysterectomy. Percutaneous pielography revealed narowing of the distal ureter, without endoureteral mass. The plain abdomen film incidentally showed a 3-cm calcified ring on the left renal shadow, who resulted external to the collecting system at pielography. A 3-dimensional-CT scan with angiographic reconstruction revealed a 3-cm calcified renal artery aneurysm. The vascular surgeon suggested a watchful waiting. The patient underwent ureteral reimplantation with ureteral stenting, allowing a complete recovery of iatrogenic stenosis two months postoperatively.