Robotic-Assisted Endovascular Treatment for Transplant Renal Artery Stenosis: A Feasibility Study.

PURPOSE: To describe a single-center experience with robotic-assisted endovascular treatment for transplant renal artery stenosis. MATERIALS AND METHODS: This is a single-center, retrospective, feasibility study of 4 consecutive cases of robotic-assisted endovascular surgery for transplant renal artery stenosis from October 2021 to August 2022. RESULTS: All lesions were identified, and stenting was performed with no complications. Conversion to manual control was not necessary. The mean fluoroscopy time was 25.25 min (range 12-60.9). A control Doppler ultrasound was routinely performed, demonstrating no residual lesions in all cases. There was no reintervention during the follow-up period. The operator learning curve was felt to be acceptable. CONCLUSION: Robotic-assisted endovascular treatment is a feasible technique for transplant renal artery stenosis.

Acute kidney injury in children undergoing cardiac surgery: predictive value of kidney arterial Doppler-based variables.

BACKGROUND: Acute kidney injury (AKI) is a common condition in critically ill children and is associated with increased morbidity and mortality. This study aimed to assess the performance of point-of-care ultrasonography to predict AKI in children undergoing cardiac surgery. METHODS: In this prospective study, consecutive children underwent kidney Doppler ultrasound examination within 24 h following cardiac surgery, and an experienced operator obtained both renal resistive index (RRI) and renal pulsatility index (RPI). AKI was defined by the Kidney Disease Improving Global Outcome (KDIGO) criteria. The primary outcome was the diagnosis of severe AKI (KDIGO stage 2 or 3) on day 3. RESULTS: A total of 58 patients were included. Median age and weight were 12.9 months (IQR 6.0-37.9) and 7.36 kg (IQR 5.19-11.40), respectively. On day 3, 13 patients were classified as having AKI, of which 11 were severe. RRI could effectively predict AKI (area under the ROC curve [AUC] 0.83, 95% CI 0.71-0.92; p < 0.001) as well as RPI (AUC 0.81, 95% CI 0.69-0.90; p < 0.001). The optimal cutoff value for RRI was 0.85 (sensitivity, 73%; specificity, 83%; positive predictive value [PPV], 50%; and negative predictive value [NPV], 93%), while for RPI was 1.95 (sensitivity, 73%; specificity, 78%; PPV, 44%; and NPV, 92%). Similar results were found in the analysis for prediction on day 5. Significant correlations were found between Doppler-based variables and estimated GFR and furosemide dose on day 3. CONCLUSIONS: Kidney Doppler ultrasound may be a promising tool for predicting AKI in children undergoing cardiac surgery.

Takayasu's arteritis presenting as acute STEMI.

An 18-year-old man with past medical history of secondary arterial hypertension diagnosed at age 15 presented with an abdominal magnetic resonance imaging (MRI) that exhibited left renal artery stenosis.

Resistivity and pulsatility indexes in feline kidney disease: a systematic review.

Doppler ultrasonography is used in the evaluation of hemodynamics, and the resistivity (RI) and pulsatility (PI) indexes provide information about resistance to blood flow within a vessel. This systematic review was carried out to evaluate renal RI and PI in clinically healthy and nonsedated cats and as well as their usefulness in the evaluation of kidney disease in cats. An electronic search in the PubMed, Scopus, and Web of Science databases was carried out using the terms "resistive index" or "resistivity index" or "pulsatility index;" "Doppler;" "renal" or "kidney;" and "cat" or "feline" in titles, abstracts, and keywords. Variables of interest related to experimental model features, research methods, and technical resources were extracted from the studies. The methodological quality was assessed with SYRCLE's risk of bias tool. Thus, 14 studies involving healthy and sick cats were selected. Interestingly, the upper limits estimated for both RI and PI varied among studies. The upper limits of renal RI for healthy cats varied between 0.64 and 0.72, while for PI, the values varied from 1.06 to 1.29. A limited number of studies evaluated cats with kidney disease. In most studies, RI values of kidneys with different conditions were significantly different from kidneys of healthy animals, indicating that RI values increase with kidney disease. The parameters body weight, heart rate, and age seem to influence the RI values. Standardized studies regarding its realization and description are still necessary to define normal values and analyze its applicability in the clinical diagnostic routine.

Spontaneous renal artery dissection: angioplasty with stent implantation in one-year follow-up.

Spontaneous renal artery dissection is an unusual and idiopathic condition in most cases. In young, mildly symptomatic patients, diagnosis may be difficult, frequently culminating in delay in treatment. This report presents the case of a 40-year-old male patient, with severe hypertension of sudden onset, and difficult management of oral medication. In etiological investigation, Echo-Doppler of renal arteries showed signs of hemodynamically relevant right renal artery stenosis. Arteriography showed presence of double-lumen and thrombus in the vessel lumen, indicating dissection. The proposed treatment was endovascular approach after failure of isolated medical treatment, option which included the aspiration of the thrombus by Penumbra System® device and balloon angioplasty, followed by right renal artery stenting. Improvement of immediate sonographic control of peak systolic velocity and renal-aortic ratio was shown, with a consequent reduction of systemic arterial blood pressure and stabilization of renal function. Within the following year, the patient presented in-stent stenosis and was successfully treated with balloon angioplasty.

Multilayer stents affect the final diameter of aortic aneurysms and maintain renal artery patency for a short time in a swine experimental model.

OBJECTIVES: We sought to analyze the hemodynamic effects of the multilayer flow-modulated stent (MFMS) in Thoracoabdominal aortic aneurysms (TAAAs). METHODS: The hemodynamic effects of MFMS were analyzed in aortic thoracoabdominal aneurysms in experimental swine models. We randomly assigned 18 pigs to the stent or control groups and underwent the creation of an artificial bovine pericardium transrenal aneurysm. In the stent group, an MFMS (Cardiatis, Isnes, Belgium) was immediately implanted. After 4 weeks, we evaluated aneurysm sac thrombosis and renal branch patency by angiography, duplex scan, and morphological analysis. RESULTS: All the renal arteries remained patent after re-evaluation in both groups. Aneurysmal sac thrombosis was absent in the control group, whereas in the stent group it was present in 66.7% of aneurysmal sacs (p=0.061).The mean final aneurysm sac diameter was significantly lower in the stent group (mean estimated reduction, 6.90 mm; p=0.021). The proximal neck diameter decreased significantly in the stent group (mean difference, 2.51 mm; p=0.022) and grew significantly in the control group (mean difference, 3.02 mm; p=0.007). The distal neck diameter increased significantly in the control group (mean difference, 3.24 mm; p=0.017). There were no significant findings regarding distal neck measurements in the stent group. CONCLUSION: The MFMSs remained patent and did not obstruct the renal arteries within 4 weeks. In the stent group, the device was also associated with a significant decrease in aneurysmal sac diameter and a large proportion (albeit non-significant) of aneurysmal sac thrombosis.

Multilayer stents affect the final diameter of aortic aneurysms and maintain renal artery patency for a short time in a swine experimental model

OBJECTIVES: We sought to analyze the hemodynamic effects of the multilayer flow-modulated stent (MFMS) in Thoracoabdominal aortic aneurysms (TAAAs). METHODS: The hemodynamic effects of MFMS were analyzed in aortic thoracoabdominal aneurysms in experimental swine models. We randomly assigned 18 pigs to the stent or control groups and underwent the creation of an artificial bovine pericardium transrenal aneurysm. In the stent group, an MFMS (Cardiatis, Isnes, Belgium) was immediately implanted. After 4 weeks, we evaluated aneurysm sac thrombosis and renal branch patency by angiography, duplex scan, and morphological analysis. RESULTS: All the renal arteries remained patent after re-evaluation in both groups. Aneurysmal sac thrombosis was absent in the control group, whereas in the stent group it was present in 66.7% of aneurysmal sacs (p=0.061). The mean final aneurysm sac diameter was significantly lower in the stent group (mean estimated reduction, 6.90 mm; p=0.021). The proximal neck diameter decreased significantly in the stent group (mean difference, 2.51 mm; p=0.022) and grew significantly in the control group (mean difference, 3.02 mm; p=0.007). The distal neck diameter increased significantly in the control group (mean difference, 3.24 mm; p=0.017). There were no significant findings regarding distal neck measurements in the stent group. CONCLUSION: The MFMSs remained patent and did not obstruct the renal arteries within 4 weeks. In the stent group, the device was also associated with a significant decrease in aneurysmal sac diameter and a large proportion (albeit non-significant) of aneurysmal sac thrombosis.

[Congenital renal arteriovenous fistula: a rare cause of acute abdomen and a review of its literature]. / Fístula arteriovenosa renal congénita: una causa rara de abdomen agudo y revisión de la literatura.

Introduction: Congenital renal arteriovenous fistula is an abnormal connection between the arterial and venous system. Since the first case described in 1928 by Varela et al, no more than 200 cases have been published. Material and methods: A 45-year-old woman consulted for severe abdominal and low-back pain associated with arterial hypertension. The CT scan showed an infrarenal retroperitoneal lesion with invasion of neighboring structures. Results: During the abdominal exploration, a vascular-looking lesion of 60 x 34 x 41 mm was identified. It was associated with right nephrectomy. Discussion: The etiology of congenital fistulas remains unknown; it is believed that a congenital arterial aneurysm erodes into an adjacent vein and gradually increases its size. Other authors believe that the fistula exists since birth and gradually increases its size until it causes symptoms. Conclusion: Congenital arteriovenous fistulas are rare entities, representing less than 25% of all renal arteriovenous malformations.

Introducción: La fístula arteriovenosa renal congénita es una conexión anómala entre el sistema arterial y venoso. Desde el primer caso descrito en 1928 por Varela y cols, no más de 200 casos han sido publicados. Material y Método: Mujer de 45 años consultó por dolor abdominal y lumbar severo, asociado a hipertensión arterial. En tomografía computada se observó lesión retroperitoneal infrarrenal con invasión de estructuras vecinas. Resultados: En exploración abdominal se identificó lesión de aspecto vascular de 60 x 34 x 41 mm. Se asoció a nefrectomía derecha. Discusión: La etiología de las fístulas congénitas sigue siendo desconocida, se cree que un aneurisma arterial congénito erosiona hacia una vena adyacente y aumenta su tamaño lentamente. Otros autores creen que la fístula existe desde el nacimiento e incrementa progresivamente de tamaño hasta producir síntomas. Conclusión: Las fístulas arteriovenosas congénitas son entidades raras, representando menos del 25% del total de las malformaciones arteriovenosas renales.

Complex Aortic, Visceral and Renal Arteries Reconstruction with a Four-Branch Dacron Graft for Middle Aortic Syndrome Secondary to Takayasu's Arteritis.

The middle aortic syndrome (MAS) is an uncommon clinical expression as a result of isolated stenosis or complete occlusion of the descending thoracic and/or abdominal aorta; Takayasu's arteritis (TA) is a rare vasculitis and a recognized etiology of MAS. We herein present the case of a 52-year-old woman with refractory renovascular hypertension and progressive bilateral lower extremity claudication; she had known history of TA. A computed tomography angiography demonstrated an aortic occlusive lesion compromising the origin of the celiac trunk, superior mesenteric, and bilateral renal arteries. The patient underwent a complex aortic reconstruction with visceral and renal vessels revascularization utilizing a back-table hand-crafted 4-branch Dacron graft through a left thoracoabdominal approach. The patient recovered uneventfully and was discharged on postoperative day 5, and at 36 months from her surgery, she remains symptoms-free and without antihypertensive agents.

Descripción anatómica de la arteria polar renal accesoria y su relación con la hipertensión arterial / Anatomical description of accessory renal polar artery and its relationship with arterial hypertension

La irrigación renal incluye la arteria renal y las arterias renales accesorias. Uno de estos vasos accesorios es la arteria polar renal superior o inferior. Estos vasos tienen un desarrollo embrionario y un origen anatómico similar a la arteria renal, tanto en la aorta abdominal como en sus ramas. Irrigan los segmentos renales correspondientes y se ha observado que su obliteración puede ser causa de aumento de la presión arterial, al estimular un aumento de renina circulante. El objetivo de este trabajo, es presentar un reporte de caso clínico de paciente masculino de 24 años, sin antecedentes mórbidos. Consulta por un cuadro de cefalea y mareos de 2 semanas de evolución. Clínicamente se pesquisó aumento de presión arterial y obesidad, sin fiebre ni otros hallazgos significativos. Los exámenes complementarios arrojan las siguientes alteraciones: triglicéridos (aumentados), presión arterial (aumentada), renina (aumentada) y AngioTac de abdomen evidenció una arteria renal polar accesoria superior izquierda, con estenosis vascular. La literatura indica que la hipertensión arterial esta correlacionada con la obstrucción parcial o total de una arteria renal o de una rama accesoria. Esta alteración en la disminución del flujo sanguíneo podría estimular la liberación de renina al torrente sanguíneo, afectando la presión arterial. Nuestros hallazgos concuerdan con lo descrito en la literatura y requieren ser considerados en el diagnóstico de hipertensión arterial. Este caso evidencia la necesidad de realizar una revisión exhaustiva de la base anatómica de la medicina con un enfoque integrativo, lo que permitirá mejorar el diagnóstico, el tratamiento y el pronóstico de patologías donde esta información es poco clara o inexistente.

The kidney irrigation includes the renal artery and the accessory renal arteries. One of these accessory vessels is the superior or inferior renal polar artery. These vessels have an embryonic development and an anatomical origin similar to the renal artery, both in the abdominal aorta but also of its branches. Irrigate the corresponding renal segments and it has been observed that their obliteration may cause increased blood pressure, by stimulating an increase in circulating renin. The objective of this work is to present a clinical case report of a 24year-old male patient, with no morbid history. Consultation due to headache and dizziness symptoms with 2 weeks of evolution. Clinically increased blood pressure and obesity, without fever or other significant findings. Corresponding exams showed the following changes: triglycerides (increased), blood pressure (increased), renin (increased) and abdominal AngioTac showed a left upper accessory polar renal artery with vascular stenosis. The literature indicates that arterial hypertension is correlated with partial or total obstruction of a renal artery or an accessory branch. This alteration in the decrease in blood flow could stimulate the release of renin into the bloodstream, affecting blood pressure. Our findings agree with what is described in the literature and need to be considered in the diagnosis of arterial hypertension. This case demonstrates the need for an exhaustive review of the anatomical basis of medicine with an integrative approach. This would improve diagnosis, treatment and prognosis of pathologies where this information is unclear or non-existent.

Cocaine-Induced Renal Artery Dissection as a Cause of Secondary Hypertension: A Rare Presentation.

BACKGROUND Cocaine abuse is a globally recognized problem with great socioeconomic and health impacts on society. We report a case of dissection of vertebral arteries and right renal artery after cocaine abuse that clinically presented as atypical headache and hypertension. CASE REPORT A 36-year-old male sought emergency care due to cervical pain after cocaine abuse. The pain was located to the right cervical side with irradiation to the homolateral temporal region. He had no previous comorbidities, except for cocaine abuse on a weekly basis. Angiotomography showed alterations compatible with recent arterial dissection of the right vertebral artery, confirmed on angioresonance. The patient received double anti-aggregation and antihypertensive drugs and was discharged. He was readmitted 5 days later due to hypertensive crisis and mild abdominal pain. Abdominal ultrasound with a Doppler of renal arteries showed signs right renal artery stenosis. Magnetic resonance angiography confirmed dissection of the same vessel. The patient underwent arteriography with stent implantation in the right renal artery. During outpatient follow-up, he progressed with gradual reduction of antihypertensive drugs. CONCLUSIONS There is only 1 case report correlating renal artery dissection with cocaine use and none with concomitant presentation of dissection in the vertebral and renal arterial beds. The scarcity of reports is a consequence of many problems. Therefore, young patients presenting with new-onset hypertension or abdominal pain and cocaine abuse history should raise suspicion for renal artery dissection.

Left renal artery thrombosis in a 78-year-old patient with atrial fibrillation.

Renal artery thrombosis is a rare clinical condition. Often, there is a delay in diagnosis due to non-specific clinical complaints. We presented a woman with an elderly atrial fibrillation who developed thrombosis of the left renal artery. Despite the anticoagulant treatment given, patient did not benefit and the kidney was fully damaged.

An augmented patient-specific approach to administration of contrast agent for CT renal angiography

ABSTRACT Purpose This hybrid retrospective and prospective study performed on 200 consecutive patients undergoing renal CTA, investigates the opacification of renal vasculature, radiation dose, and reader confidence. Materials and Methods 100 patients were assigned retrospectively to protocol A and the other 100 were allocated prospectively to protocol B. Both protocols implemented a contrast material and saline flow rate of 4.5 mL/sec. Protocol A utilized a 100 mL of low-osmolar nonionic IV contrast material (Ioversol 350 mg I/mL) while protocol B employed a patient-tailored contrast media formula using iso-osmolar non-ionic (Iodixanol 320 mg I/mL). Results Arterial opacification in the abdominal aorta and in the bilateral main proximal renal arteries demonstrated no statistical significance (p>0.05). Only the main distal renal artery of the left kidney in protocol B was statistically significant (p<0.046). In the venous circulation, the IVC demonstrated a significant reduction in opacification in protocol B (59.39 HU ± 19.39) compared to A (87.74 HU ± 34.06) (p<0.001). Mean CNR for protocol A (22.68 HU ± 13.72) was significantly higher than that of protocol B (14.75 HU ± 5.76 p< 0.0001). Effective dose was significantly reduced in protocol B (2.46 ± 0.74 mSv) compared to A (3.07 ± 0.68 mSv) (p<0.001). Mean contrast media volume was reduced in protocol B (44.56 ± 14.32 mL) with lower iodine concentration. ROC analysis demonstrated significantly higher area under the ROC curve for protocol B (p< 0.0001), with inter-reader agreement increasing from moderate to excellent in renal arterial visualization. Conclusion Employing a patient-tailored contrast media injection protocol shows a significant refinement in the visualization of renal vasculature and reader confidence during renal CTA.

Anterior spinal artery syndrome and aortic dissection.

BACKGROUND: Anterior spinal artery syndrome, usually resulting in flaccid paraplegia, is a rare but disastrous complication that can occur after surgery of aortic aneurysms and aortic dissections. Spinal cord infarct as the initial clinical presentation of aortic dissection is a very rare finding. CASE REPORT: A 42-year-old male patient who comes to the emergency department due to severe chest pain associated with presyncope and paraplegia of the lower limbs in the context of type A aortic dissection. CONCLUSIONS: Recognizing this atypical clinical presentation of aortic dissection and knowing how to approach it is critical for an early diagnosis and to minimize the risk of spinal cord ischemia during surgery.

ANTECEDENTES: La lesión de la médula espinal, generalmente resultante en paraplejia flácida, es una complicación rara, pero desastrosa, que puede ocurrir tras intervenciones quirúrgicas de aneurismas o disecciones de aorta. La presentación clínica inicial de una disección de aorta como un síndrome de la arteria espinal anterior es un hallazgo muy infrecuente. CASO CLÍNICO: Varón de 42 años que acude al servicio de urgencias hospitalario por dolor torácico intenso asociado a cuadro presincopal y paraplejia de miembros inferiores en el contexto de una disección de aorta tipo A. CONCLUSIONES: Reconocer esta forma de presentación clínica y saber cómo realizar un abordaje adecuado es fundamental para el diagnóstico precoz y para minimizar el riesgo quirúrgico de presentar isquemia medular.

An augmented patient-specific approach to administration of contrast agent for CT renal angiography.

PURPOSE: This hybrid retrospective and prospective study performed on 200 consecutive patients undergoing renal CTA, investigates the opacification of renal vasculature, radiation dose, and reader confidence. MATERIALS AND METHODS: 100 patients were assigned retrospectively to protocol A and the other 100 were allocated prospectively to protocol B. Both protocols implemented a contrast material and saline flow rate of 4.5 mL/sec. Protocol A utilized a 100 mL of low-osmolar nonionic IV contrast material (Ioversol 350 mg I/mL) while protocol B employed a patient-tailored contrast media formula using iso-osmolar non-ionic (Iodixanol 320 mg I/mL). RESULTS: Arterial opacification in the abdominal aorta and in the bilateral main proximal renal arteries demonstrated no statistical significance (p>0.05). Only the main distal renal artery of the left kidney in protocol B was statistically significant (p<0.046). In the venous circulation, the IVC demonstrated a significant reduction in opacification in protocol B (59.39 HU ± 19.39) compared to A (87.74 HU ± 34.06) (p<0.001). Mean CNR for protocol A (22.68 HU ± 13.72) was significantly higher than that of protocol B (14.75 HU ± 5.76 p<0.0001). Effective dose was significantly reduced in protocol B (2.46 ± 0.74 mSv) compared to A (3.07 ± 0.68 mSv) (p<0.001). Mean contrast media volume was reduced in protocol B (44.56 ± 14.32 mL) with lower iodine concentration. ROC analysis demonstrated significantly higher area under the ROC curve for protocol B (p<0.0001), with inter-reader agreement increasing from moderate to excellent in renal arterial visualization. CONCLUSION: Employing a patient-tailored contrast media injection protocol shows a significant refinement in the visualization of renal vasculature and reader confidence during renal CTA.