Inferior Renal Artery Research Articles

Real-time laser speckle contrast imaging measurement during normothermic machine perfusion in pretransplant kidney assessment.

Normothermic machine perfusion (NMP) provides a platform for pre-transplant kidney quality assessment that is essential for the use of marginal donor kidneys. Laser speckle contrast imaging (LSCI) presents distinct advantages as a real-time and noncontact imaging technique for measuring microcirculation. In this study, we aimed to assess the value of LSCI in visualizing renal cortical perfusion and investigate the additional value of dual-side LSCI measurements compared to single aspect measurement during NMP. Porcine kidneys were obtained from a slaughterhouse and then underwent NMP. LSCI was used to measure one-sided cortical perfusion in the first 100 min of NMP. Thereafter, the inferior renal artery branch was occluded to induce partial ischemia and LSCI measurements on both ventral and dorsal sides were performed. LSCI fluxes correlated linearly with the renal blood flow (R2 = 0.90, p < 0.001). After renal artery branch occlusion, absence of renal cortical perfusion could be visualized and semiquantified by LSCI. The overall ischemic area percentage of the ventral and dorsal sides was comparable (medianinterquartile range[IQR], 38 [24-43]% vs. 29 [17-46]%, p = 0.43), but heterogenous patterns between the two aspects were observed. There was a significant difference in oxygen consumption (mean ± standard deviation [SD], 2.57 ± 0.63 vs. 1.83 ± 0.49 mLO2 /min/100 g, p < 0.001), urine output (median [IQR], 1.3 [1.1-1.7] vs. 0.8 [0.6-1.3] mL/min, p < 0.05), lactate dehydrogenase (mean ± SD, 768 ± 370 vs. 905 ± 401 U/L, p < 0.05) and AST (mean ± SD, 352 ± 285 vs. 462 ± 383 U/L, p < 0.01) before and after renal artery occlusion, while no significant difference was found in creatinine clearance, fractional excretion of sodium, total sodium reabsorption and histological damage. LSCI fluxes correlated linearly with renal blood flow during NMP. Renal cortical microcirculation and absent perfusion can be visualized and semiquantified by LSCI. It provides a relative understanding of perfusion levels, allowing for a qualitative comparison between regions in the kidney. Dual-side LSCI measurements are of added value compared to single aspect measurement and renal function markers.

Variations in the Drainage Pattern of Testicular and Renal Veins, and Bilateral Duplication of Renal Arteries with Prehilar Divisions

The dissection of a 76-year-old male donor with a consent for research and publication, revealed variations of the renal and testicular vasculature where the right testicular vein joined a right accessory renal vein to form a common trunk that opened into the right renal vein. The left renal vein descended obliquely to the left ventral to the pair of left renal arteries, under crossed the prehilar branches of the arteries dorsally as it approaches the left kidney and entered the hilum posterior to the arterial branches. Both kidneys were supplied by two renal arteries (superior and inferior). The left superior renal artery followed the course of the left renal vein, crossed inferiorly ventral to the inferior renal artery, and then the last part of the left renal vein to enter the lower corner of the hilum of the left kidney. The bilaterally duplicated renal arteries broke up into anterior and posterior prehilar (early) divisions that entered the respective kidney. The co-occurrence of such multiple and complex a variation is of nephron-urological importance and can complicate nephro-surgeries, interventional radiologic procedures and the management of abdominal aortic aneurysm.

Risk factors and adverse events related to supra- and infra-renal aortic dilation at twelve months after endovascular abdominal aortic aneurysm repair.

Aortic remodeling and its effect on adverse events after endovascular abdominal aneurysm repair (EVAR) remain under investigation. This study aimed to assess aortic diameter alterations after EVAR, related risk factors and consequences to proximal sealing at 12 months. A single-center retrospective analysis of consecutive EVAR patients was undertaken. All patients underwent computed tomography angiography, preoperatively, at 1st and 12th month. The infrarenal diameter was measured just below the inferior renal artery, at 7 mm and 15 mm while the suprarenal, just above the superior renal artery (SRA), superior mesenteric artery (SMA) and just below the celiac trunk. Neck-related adverse events included migration and endoleak Ia. A hundred fifty patients were included. At 1st month, no significant diameter alteration was recorded at any level. At 12th month, all infra-renal diameters increased (P<0.001) and diameters at SRA and SMA also augmented (P=0.024 and P=0.007, respectively). Neck diameter >29 mm, supra-renal fixation and oversizing >20% were associated to dilation at 12th month. Neck adverse events were related to diameter alterations below the inferior renal artery (P=0.017), SRA (P=0.007) and SMA (P=0.05). During the 12-month follow-up, aortic dilation may be detected from the supra-renal aorta to the total neck length. Neck dilation may be attributed to large neck diameter, supra-renal fixation, and aggressive oversizing. Neck-related adverse events are more common in patients with aortic dilation at 12 months.

LBODP015 A Pheochromocytoma Presenting With Hypertensive Emergency With A Rare Complication Of Unilateral Adrenal Hemorrhage

Abstract Introduction Adrenal hemorrhage is an uncommon finding in patients and is estimated to be present in 0.14-1.8% of postmortem examinations. Clinical diagnosis is challenging due to its non-specific presentation and most cases are diagnosed incidentally on imaging. Here we discuss the clinical presentation, diagnostic procedures, and outcome of this rare case. Clinical Case A 74-year-old Asian female presented to the ED with a sudden onset of severe epigastric pain with 9/10 intensity, radiating to her upper back while walking on the street. She was found in severe distress with a blood pressure of 214/80 mmHg, heart rate of 72 bpm, respiratory rate of 20 breaths/min, and oxygen saturation of 98% on room air. The physical exam was unremarkable. Laboratory findings were significant for elevated troponin of 1. 040 ng/ml (0. 00-0. 03 ng/ml), lactate 2.36mmol/L (0.70-2. 00 mmol/L), and lipase 481U/L (23-300 U/L). Chest X-ray was within normal limits. A CT angiogram of the chest and abdomen were negative for aortic dissection, however, a retroperitoneal hemorrhage measuring 6×8.5×6.5 cm was seen but an underlying adrenal gland mass could not be excluded. The patient was started on nitroglycerine drip for blood pressure control. Hemoglobin trend showed an acute drop, requiring 2 units of red blood cell transfusion. This raised concerns of worsening hemorrhage. Repeat imaging showed no significant change in the left adrenal hematoma, but arterial phase imaging still suggested active bleeding. Interventional radiology was consulted, and embolization of the left superior and inferior renal artery was done with stabilization of the patients hemodynamics. Laboratory work for secondary causes of hypertension was done. It showed elevated normetanephrines 1281 mcg/24hr (122 - 676 mcg/24hr) and total 24-hour urine metanephrines, 114 mcg/24hr (224-832 mcg/24 hr). The patients blood pressure was controlled and therefore asked for follow-up as an outpatient. Conclusion The majority of adrenal hemorrhages diagnosed are found incidentally, but initial symptoms of abdominal or loin pain are very important. Early acute findings may include tachycardia, hypotension, and severe abdominal pain. Subacute symptoms include flank tenderness, diarrhea, malaise, nausea, and vomiting. Unilateral adrenal hemorrhage may be the initial presentation of an underlying adrenal mass, cyst, coagulopathy or metastasis. Elevated cortisol and catecholamines released by an expanding hematoma are often seen along with elevated blood pressure, suggesting pheochromocytoma. The Hormonal analysis includes urine metanephrine and vanillylmandelic acid to rule out active pheochromocytoma. In our case, the patient had elevated urine metanephrines and normetanephrines suggestive of pheochromocytoma. Presentation: No date and time listed

Horseshoe Kidney with Surplus Renal Arteries, Veins, and Roots of the Ureters

We report the anatomical findings of a kidney discovered in a 92‐year‐old male during a routine dissection of the abdominal viscera performed by medical students at the Oakland University William Beaumont School of Medicine. The lower poles of the kidney are fused together, forming an isthmus anterior to the aorta and inferior vena cava at the L3‐L4 vertebral level. The right and left kidneys ascend past the isthmus, forming a “U” shape, the defining feature of a horseshoe kidney. The left kidney stops prematurely, approximately 3.2 cm below the inferior mesenteric artery at the level of the left inferior renal artery. The right kidney drains into superior, inferior, and middle renal arteries which have three, two, and one branches respectively. Due to the size and position of the hilum, five separate roots extend outside the kidney into the right ureter. The left side is supplied by a superior and inferior renal artery, each dividing into two branches. The left inferior renal artery branches off the ventral face of the descending aorta. The left renal vein notably has three prominent tributaries from the kidney and an additional branch of the left adrenal vein. Six roots extend from the left hilum and drain into the left ureter. In total, the kidney has nine veins, six arteries, and eleven ureteric branches draining into the left and right ureters. These findings will be useful in regard to research and surgery on other horseshoe kidneys.

Intravascular ultrasound-supported percutaneous angioplasty of post-kidney transplant renal artery bifurcation stenosis.

Transplant renal artery stenosis (TRAS) is an uncommon complication following renal transplantation. Its usual clinical presentation includes worsening hypertension and/or renal function, without any evidence of graft rejection. Bifurcation renal artery stenosis of the transplanted renal artery is rarely encountered. Percutaneous transluminal renal angioplasty (PTRA) with or without stenting is the procedure of choice to treat TRAS. We hereby describe a patient, who presented with impaired renal functions, four months following the renal transplantation. He underwent intravascular ultrasound-guided PTRA of the bifurcation lesion of TRAS.Results and conclusion: Superior renal artery had coronary drug-eluting stent implantation, while inferior renal artery and side branch of the superior renal artery had balloon angioplasty, alone. Post-intervention, the raised serum creatinine level decreased from 2.9 mg% to 1.7 mg%. The index case described the successful PTRA and stenting of the bifurcation lesion of TRAS, the technical results of which was optimized with the use of intravascular ultrasound.

Treatment Results of Endovascular Aneurysm Repair Using the Parallel Stent-Graft Double D Technique for Distal Saccular Abdominal Aortic Aneurysms and Common Iliac Aneurysms

Endovascular aneurysm repair (EVAR) using a bifurcated stent graft may involve technical challenges when aortic disease (aneurysm or dissection) consists of a length <70mm between the inferior renal artery and aortic bifurcation or narrow aortic bifurcation that is common in asymmetric distal abdominal aortic aneurysms (AAAs) or iliac artery aneurysms (IAAs). We use EVAR with the double D technique (DDT-EVAR) for such cases, which involves straight type of stent grafts with same diameter in left and right that are deployed parallel to an aortic cuff that has been previously placed. In addition, DDT-EVAR can preserve the inferior mesenteric artery (IMA) for IAA. DDT-EVAR was performed for 21 of 910 (2%) cases from April 2007 to April 2019 at our institution. The median patient age was 74years (range, 52-85). Nineteen patients (90%) were men. Six patients (all saccular; 1 rupture) had AAAs, 12 had IAAs, and 3 had chronic type B aortic dissociation (TBAD) for re-entry closure. AAA and IAA had diameters of 45mm (range, 34-71) and 34mm (range, 25-58), respectively. An aortic cuff was used for 19 (90%) cases. Endurant II (Medtronic, Santa Rosa, CA) was used for 12 cases. The Excluder (W.L. Gore & Associates, Inc, Flagstaff, AZ) was used for 7 cases. Endurant II was used for 20 cases, and the VBX (W.L. Gore & Associates, Inc) was used for 1 case as stent-graft limbs. The procedural success rate was 100%. The median operative time was 146min (range, 88-324). IMA planned for preservation was successful for all 12 cases. Type I and type III endoleaks were not observed. With TBAD, flow to the false lumen decreased or disappeared, and no complications during the hospital stay were associated with the procedure. For 2 patients whose procedure involved Endurant II stent-graft limb, limb occlusions were observed postoperatively, and reintervention was required. No other patients required additional treatment at a median follow-up of 18months (range, 4-50). DDT-EVAR is a safe and straightforward technique for the treatment of distal AAA, common iliac artery aneurysm, and TBAD. It may help preserve the IMA and internal iliac artery, even when it is impossible to preserve them with a bifurcated stent graft.

Treatment Results of Endovascular Aneurysm Repair Using the Parallel Stent Graft Double D Technique for Distal Aortic and Common Iliac Aneurysms

Endovascular aneurysm repair (EVAR) using a bifurcated stent graft may involve technical challenges when asymmetric distal abdominal aortic aneurysms (AAAs) and iliac artery aneurysms (IAAs) are encountered, especially with inferior renal artery aortic bifurcation <70 mm or narrow aortic bifurcation. We use EVAR with the double D technique (DDT-EVAR) for such cases. This involves a stent graft limb with the same diameter as the left and right diameters that is deployed parallel to an aortic cuff that has been previously placed (Fig).

Long-Term Implantability of Resorbable Carboxymethyl Cellulose/Chitosan Microspheres in a Rabbit Renal Arterial Embolization Model.

To determine the physiologic response to resorbable carboxymethyl cellulose/chitosan (CMC/CN) microspheres in a long-term rabbit model, including the clinical response, gross pathology, and histopathology. Six rabbits were embolized with CMC/CN microspheres (300-500µm) in one kidney via an inferior renal artery branch. Angiography was performed immediately before and after embolization and prior to killing at 6months (180 ± 7days, n = 3) and 12months (365 ± 10days, n = 3). A complete necropsy was performed on each animal with dissection of the kidneys and harvesting of additional tissues as per ISO-10993-part 6 and ISO-10993-part 11 guidelines. All tissues were processed and stained for pathological analysis. The caudal third of target kidneys was successfully embolized with CMC/CN microspheres. Over the course of the study, there were neither notable clinical signs in either embolization group nor significant changes in the tissue/body weight ratio between 6- and 12-month time points. Gross examination revealed that all embolized kidneys had morphologic features consistent with infarction resulted from microsphere delivery. The percentage of infarction decreased from 9.1% ± 5.7% at 6months to 1.9% ± 0.4% at 12months. Microscopically, infarcted areas demonstrated evidence of chronic injury and repair, including loss of renal parenchyma with replacement fibrosis, tubular regeneration, and minimal to mild lymphoplasmacytic inflammation without any active changes such as necrosis or neutrophilic inflammation. No systemic toxicity was observed in the animals 6 and 12months after CMC/CN microspheres delivery. The local tissue response was mild.

Real-Life Experience with Ovation Stent Graft: Lesson Learned from the First One Hundred Fifty Treated Patients

The objective of the study was to report immediate and midterm results of an unselected population of patients treated for abdominal aortic aneurysms (AAAs) by endovascular aneurysm repair (EVAR) using the Ovation stent graft. A double-center retrospective study was conducted on a prospectively collected database between 2012 and 2015. One hundred fifty-six elective patients were included. The outcome measures considered for analysis were primary technical success, 30-day and midterm reinterventions, and all-cause and AAA-related mortality rates. The presence of an aortic neck ≤10 mm, and of a noncylindrical aortic neck, as well as a narrowed aortic bifurcation was defined as an aortic bifurcation average diameter (ABaverage) ≤ 18mm or an ABarea ≤ 20mm2, and an external iliac artery diameter ≤5mm was considered as independent factors potentially influencing the outcome. Male patients totaled 128 (82.1%), and mean age was 74.83±6.76years (range: 56-91). Mean aortic diameter was 57.15±8.77mm, mean diameter at inferior renal artery level + 13 was 24.44±3.31mm, and mean aortic neck length was 18.77±8.45mm. Fifty-four patients (34.6%) had an aortic neck ≤10mm, and cylindrical aortic neck shape was presentin34 patients (21.8%). Regarding the aortic bifurcation (AB), 31 patients (19.9%) presented ABaverage ≤ 18mm, and 35 (22.4%) an ABarea ≤ 20mm2. Technical success was achieved in all cases. At 30-day follow-up, 2 type I endoleaks (1.3%) were detected. One patient was successfully treated endovascularly by proximal aortic cuff implantation, while the other patient refused further treatment. Three-month unscheduled computed tomographic angiography shows endoleak resolution and complete aneurysm seal. One patient suffered from a limb graft occlusion, managed by medical treatment. At a mean follow-up time of 20.4±8.8 (1-60) months, 6 reinterventions were reported, including 2 embolizations for type II endoleak and 4 for iliac and femoral vessel occlusive disease. Log-rank test on preoperative anatomical features showedno significant differences in terms of freedom from reinterventions, and P values were 0.653 for aortic neck length ≤10mm, 0.309 for noncylindrical aortic neck length shape, 0.520 for ABaverage ≤ 18mm, 0.604 for ABarea ≤ 20mm2, and 0.421 for external iliac artery diameter ≤5mm. Our initial experience suggests that in an unselected patient population undergoing AAA repair, EVAR by Ovation stent graft can be performed safely with satisfactory immediate and midterm outcomes.

SEGMENTATION OF RENAL PARENCHYMA IN THE CASE OF PRESENCE OF ADDITIONAL RENAL ARTERIES

The presence of additional renal additional arteries represents the most often renal vascular variation. The analysis of the segmentation of the renal parenchyma renal in the case of the presence of additional renal arteries was performed on a number of 75 renal corrosion casts. The renal corrosion casts with the presence of additional renal arteries represented 20% from the whole studied trial (375 renal corrosion casts). The corrosion casts were realized by injecting the renal vasculo‐ductal systems with plastic mass, followed by the corrosion of the renal parenchyma with hydrochloric acid. There have been revealed 66 corrosion casts (88%) with 2 renal arteries and 9 casts with 3 renal arteries (12%). 68% of the corrosion casts presented 5 renal segments; 25.33% presented 6 renal segments; 4% of the casts presented 7 segments, 2.67% presented 8 renal segments. The main renal artery of the kidney is: the superior renal artery in 64% of the cases; the middle renal artery in 5.33% of the cases and the inferior renal artery in 30.67%. The knowledge of these morphological aspects is important for the urologic surgery of resection and transplantation (Supported by UEFISCDI 42097/2008).

Long-term follow-up of neck expansion after endovascular aortic aneurysm repair

This study determined the rate, extent, and clinical significance of neck dilatation after endovascular aneurysm repair (EVAR). The study included 46 patients who underwent elective EVAR using bifurcated Zenith stent grafts (Cook, Bloomington, Ind) and had at least 48 months of clinical and radiographic follow-up. Computed tomography images were analyzed on a 3-dimensional workstation (TeraRecon, San Mateo, Calif). Neck diameter was measured 10 mm below the most inferior renal artery in planes orthogonal to the aorta. Nominal stent graft diameter was obtained from implantation records. Median follow-up was 59 months (range, 48-120 months). Neck dilation occurred in all 46 patients. The rate of neck dilation was greatest at early follow-up intervals. At 48 months, median neck dilation was 5.3 mm (range, 2.3-9.8 mm). The extent of neck dilation at 48 months correlated with percentage of stent graft oversizing (Spearman rho = 0.61, P < .001). No type I endoleak or migration >5 mm occurred. After EVAR with the Zenith stent graft, the neck dilates until its diameter approximates the diameter of the stent graft. Neck dilation was not associated with type I endoleak or migration of the stent graft.

Treatment of Renal Artery Aneurysm With the Multilayer Stent

To describe a new type of stent consisting of a 3-dimensional (3D) braided tube made of 2 interconnected layers without any covering to treat a renal artery aneurysm. A 78-year-old hypertensive man with multiple comorbidities was incidentally found to have a large (28- x 30 mm) saccular aneurysm in the main right renal artery involving the inferior renal artery. Via a percutaneous femoral approach, a 6- x 30-mm Multilayer stent was deployed easily in front of the aneurysm neck covering the inferior renal artery. Blood flow inside the sac was immediately and significantly reduced. All the renal artery branches remained patent. Blood pressure returned to normal after the procedure. At 6 months, angiography showed complete shrinkage of the aneurysm wall; all the inferior renal artery branches remained patent. The 3D multilayer fluid modulating stent concept appears to be a viable alternative for renal aneurysm exclusion. A larger study is underway to evaluate this new stent in other peripheral aneurysms.

Duplication of the inferior vena cava associated with other variations

Multiple vascular variations, including duplication of the inferior vena cava, double renal arteries and anomalies of the testicular blood vessels, were observed during dissection of the retroperitoneal region of a cadaver of an 87-year-old Japanese man. The right inferior vena cava arose from the union of right common iliac veins and a thinner interiliac vein. This interiliac vein ascended obliquely from right to left and joined the left common iliac veins to form the left inferior vena cava. The right and left inferior venae cavae were of approximately equal width. The right testicular vein consisted of medial and lateral venous trunks. The two venous trunks coalesced to form a single vein, which drained into the confluence of the right inferior vena cava and right renal vein. The left testicular vein was composed of the medial and lateral testicular veins, which drained into the left renal vein. Double renal arteries were seen bilaterally, which originated from the lateral aspects of the abdominal aorta. The right testicular artery arose from the right inferior renal artery and accompanied the lateral trunk of the right testicular vein running downwards. The left testicular artery arose from the ipsilateral inferior renal artery and ran downwards accompanied by the left lateral testicular vein. In addition, the bilateral kidneys showed multicystic changes.

Endovascular Aortic Aneurysm Repair in a Patient With Coronary Artery Disease

A 72-year-old man with adenocarcinoma of the prostate treated in 1988 with prostatectomy presented for evaluation of chest pain. Computed tomography of the chest (upper left) revealed coronary artery calcification that was above the 90th percentile for ageand sex-matched controls, associated with at least 1 major coronary arterial stenotic lesion. Computed tomographic angiography of the abdominal aorta showed a 55 × 51-mm infrarenal abdominal aortic aneurysm. The aorta measured less than 25 mm at the level of the single renal arteries and less than 25 mm at a distance of 15 mm distal to the most inferior renal artery. The common iliac and external iliac arteries were normal with minimal atheromatous changes. Catheter-guided coronary angiography identified occlusion of the mid right coronary artery, which was the dominant coronary artery supplying the heart. Additional stenotic lesions were noted in the proximal left anterior descending artery, the posterior descending artery, and the marginal branch of the circumflex artery. A radioactive sestamibi scan with adenosine showed large reversible myocardial perfusion defects. Cardioprotective medical therapy was initiated, including β-blockade. The β-blocker therapy decreased the perfusion defects considerably, as noted on follow-up sestamibi scan. In view of the patient’s age and comorbidities, including coronary artery disease, endograft repair of the abdominal aortic aneurysm was recommended. An aortobi-iliac stent graft was placed in May 2002 (lower left). Annual follow-up computed tomography through May 2005 has revealed a progressive decrease in the size of the excluded aneurysm sac with no endovascular stent migration or endoleak (upper right and lower right).

Endoluminal repair of abdominal aortic aneurysm prevents enlargement of the proximal neck: a 9-year life-table and 5-year longitudinal study.

Endoluminal repair of abdominal aortic aneurysm (AAA) is predicated on stability of the proximal neck of the aneurysm. Reports on morphologic changes in the proximal neck after endoluminal repair of AAA have thus far been limited in duration to 3 years or less. The aim of this study was to document changes in diameter of the proximal neck of AAA in a group of patients who had undergone endoluminal repair between 5 and 9 years previously. Between May 1992 and December 1996, 61 patients with AAA were treated with endoluminal repair by the senior author. The following patients were excluded from the study group: those requiring primary conversion to open repair at the original operation (n = 8), those with false aneurysm (n = 1), and those with dissection in the proximal neck (n = 1). Fifty-one patients (48 men and three women) with a mean age of 71 years remained in the study group. The endoprostheses used were modified Parodi (n = 4), Endovascular Technologies (n = 14), White-Yu (n = 10), Stentor/Vanguard (n = 21), and Bard 1996 prototype (n = 2). Morphologic changes in the proximal aortic neck were studied with contrast computed tomographic scan with the methodology recommended by the Ad Hoc Committee for Standardized Reporting Practices for Endovascular AAA Repair (revised version). The maximum transverse diameter of the proximal neck was measured 1 cm below the most inferior renal artery. A Kaplan-Meier analysis was performed showing the proportion of patients at risk with a demonstrated enlargement of the neck at each interval of time compared with the predischarge computed tomographic scan. A longitudinal study of morphologic changes in the proximal aortic neck was also undertaken in 28 patients with successful endoluminal repair who survived 5 years. The Kaplan-Meier curve showed a probability of no dilatation of the proximal neck of 0.943 at 7 years after endoluminal AAA repair. Of 28 patients with 5 years of follow-up after discharge, only two had increases in the diameter of the proximal neck greater than 2 mm. The endograft in both patients had undergone migration before any proximal neck dilation. A paired t test showed that the overall average increase of 0.4 mm (standard error, 0.3 mm) in these 28 patients was not statistically significant (P =.23). A high probability (0.943 at 7 years) exists of no enlargement of the proximal neck of AAA after endoluminal repair. We hypothesize that endografts positioned correctly immediately below the renal arteries protect the proximal neck from dilatation in a manner that does not occur after open repair of AAA.