Stenting of a renal artery compressed by the diaphragm

Renal Artery Stenosis Due to Entrapment ()

BACKGROUND

Common etiologies of renovascular occlusive disease include atherosclerosis disease, developmental fibrotic conditions such as fibromuscular dysplasia (FMD), vasculitis. Extrinsic compression of the renal artery is a rarely reported phenomenon but can lead to similar clinical manifestations.

METHODS

We report recent experience with two patients who presented with extrinsic renal artery compression due to entrapment. Diagnosis was made with a constellation of findings on computed tomography angiography, dynamic duplex sonography, and catheter angiography. Both patients had hypertension and one had downstream subsegmental renal infarcts. The patients, both with right sided renal artery entrapment, were treated with open surgical decompression. Exposure was achieved via extended Kocher maneuver followed by mobilization of the right kidney and, in one patient, detachment of the right lobe of liver to allow circumferential exposure of the proximal right renal artery to the aorta. All entrapping tissue was circumferentially released.

RESULTS

Both operations were uncomplicated. Intraoperative sonography was used to confirm luminal patency of the released segments. Follow-up renal artery duplex in both patients demonstrated resolution of dynamic compression. Renal artery peak systolic velocity and accelerations indices were all within normal limits. In both patients, improvement in blood pressure control was noted and discontinuation of anticoagulation was possible in the patient who had recurrent episodes of renal infarct.

CONCLUSION

Extrinsic compression of renal artery by diaphragmatic crura is rare but should be considered in younger patients or otherwise any patients with no vascular risk factors when renovascular hypertension workup yields no demonstrable intrinsic disease. A high index of suspicion should be raised when an anomalously high origin of the renal artery or proximity to the diaphragmatic crura are seen on cross sectional imaging. Work-up should include dynamic imaging to assess compression of renal arteries during expiration. Open surgical or laparoscopic decompression of the involved renal arteries can be curative.

Renovascular hypertension secondary to renal artery compression by diaphragmatic crura

Median arcuate ligament syndrome is the result of celiac axis compression by the diaphragmatic crura. Although the celiac artery is the most common vessel to have compression, the renal arteries may also rarely be compressed by the crural fibers of the diaphragm, which may cause secondary hypertension. We present two cases of renovascular hypertension secondary to renal artery compression by the diaphragmatic crura. The first patient was treated with open decompression and wide resection of the crural fibers, and the second patient was decompressed laparoscopically. Neither case required renal artery reconstruction. Antihypertensives were discontinued in both patients postoperatively.

An unusual case of left renal artery compression: a rare type of median arcuate ligament syndrome

Compression from median arcuate ligament was observed during multidetector 64-row computed tomography in a Caucasian 30-year-old female. The patient was referred for examination to exclude anatomical pathologies causing hypertension. The examination demonstrated that left renal artery, which had its origin in the chest (at the level of upper one-third of Th12), was compressed as it passed by median arcuate ligament of the diaphragm. In addition, aortic compression and kinked shape was also revealed.

Fracture of a sirolimus-eluting stent in renal artery stenosis

Atherosclerosis accounts for most adult cases of renal artery stenoses (RAS). Revascularization of atherosclerotic RAS is beneficial in terms of improved blood pressure control, preservation of renal function and overall decrease of cardiovascular risk, in particular in mononephric patients. Endovascular stenting has been proven superior to percutaneous transluminal angioplasty (PTA) alone in terms of initial success and restenosis rates in atherosclerotic RAS. In this case report revascularization of atherosclerotic RAS in a mononephric patient is presented and the long-term follow-up and complications of PTA and stenting are illustrated. Our case is the first report of fracture of a sirolimus-eluting stent overlapped to a previously implanted Palmaz-Schatz in the left renal artery. The mechanisms and possible remedies of this complication are discussed.

Respiration-induced deformations of the superior mesenteric and renal arteries in patients with abdominal aortic aneurysms

PURPOSE

To quantify respiration-induced deformations of the superior mesenteric artery (SMA), left renal artery (LRA), and right renal artery (RRA) in patients with small abdominal aortic aneurysms (AAAs).

MATERIALS AND METHODS

Sixteen men with AAAs (age 73 y ± 7) were imaged with contrast-enhanced magnetic resonance angiography during inspiratory and expiratory breath-holds. Centerline paths of the aorta and visceral arteries were acquired by geometric modeling and segmentation techniques. Vessel translations and changes in branching angle and curvature resulting from respiration were computed from centerline paths.

RESULTS

With expiration, the SMA, LRA, and RRA bifurcation points translated superiorly by 12.4 mm ± 9.5, 14.5 mm ± 8.8, and 12.7 mm ± 6.4 (P < .001), and posteriorly by 2.2 mm ± 2.7, 4.9 mm ± 4.2, and 5.6 mm ± 3.9 (P < .05), respectively, and the SMA translated rightward by 3.9 mm ± 4.9 (P < .01). With expiration, the SMA, LRA, and RRA angled upward by 9.7° ± 6.4, 7.5° ± 7.8, and 4.9° ± 5.3, respectively (P < .005). With expiration, mean curvature increased by 0.02 mm(-1) ± 0.01, 0.01 mm(-1) ± 0.01, and 0.01 mm(-1) ± 0.01 in the SMA, LRA, and RRA, respectively (P < .05). For inspiration and expiration, RRA curvature was greater than in other vessels (P < .025).

CONCLUSIONS

With expiration, the SMA, LRA, and RRA translated superiorly and posteriorly as a result of diaphragmatic motion, inducing upward angling of vessel branches and increased curvature. In addition, the SMA exhibited rightward translation with expiration. The RRA was significantly more tortuous, but deformed less than the other vessels during respiration.

Respiratory-induced 3D deformations of the renal arteries quantified with geometric modeling during inspiration and expiration breath-holds of magnetic resonance angiography

PURPOSE

To quantify renal artery deformation due to respiration using magnetic resonance (MR) image-based geometric analysis.

MATERIALS AND METHODS

Five males were imaged with contrast-enhanced MR angiography during inspiratory and expiratory breath-holds. From 3D models of the abdominal aorta, left and right renal arteries (LRA and RRA), we quantified branching angle, curvature, peak curve angle, axial length, and locations of branch points.

RESULTS

With expiration, maximum curvature changes were 0.054 ± 0.025 mm(-1) (P < 0.01), and curve angle at the most proximal curvature peak increased by 8.0 ± 4.5° (P < 0.05) in the LRA. Changes in maximum curvature and curve angles were not significant in the RRA. The first renal bifurcation point translated superiorly and posteriorly by 9.7 ± 3.6 mm (P < 0.005) and 3.5 ± 2.1 mm (P < 0.05), respectively, in the LRA, and 10.8 ± 6.1 mm (P < 0.05) and 3.6 ± 2.5 mm (P < 0.05), respectively, in the RRA. Changes in branching angle, axial length, and renal ostia locations were not significant.

CONCLUSION

The LRA and RRA deformed and translated significantly. Greater deformation of the LRA as compared to the RRA may be due to asymmetric anatomy and mechanical support by the inferior vena cava. The presented methodology can extend to quantification of deformation of diseased and stented arteries to help renal artery implant development.

Surgical treatment of renal artery compression by diaphragmatic crus

Symptomatic compression of the renal artery by the diaphragmatic crus is a rare disorder. To our knowledge, renal artery compression by the diaphragmatic crus complicated with poststenosis aneurysm has not been reported. We present the case of a 28-year-old man with refractory hypertension. Extrinsic compression of the bilateral renal arteries and celiac artery and the aneurysm were proven by surgical exploration. We successfully performed left renal artery revascularization and renal autotransplantation in situ. Normal perfusion of the two bypass graft vessels was proven by computed tomography angiography.

Renal autotransplantation in a child following renal artery stent fracture

We report an 8-year-old child who underwent percutaneous transluminal renal angioplasty (PTRA) and stenting for renal artery stenosis (RAS) and later presented with stent fracture. Ex vivo renal artery repair and renal autotransplantation were successfully done.

Renal artery thrombosis caused by stent fracture: the risk of undiagnosed renal artery entrapment

We report a case of renal artery thrombosis resulting from a stent fracture in a patient with a solitary functional kidney. It was successfully revascularized by surgical repair despite renal ischemia lasting more than 48 hours. This article illustrates the danger of generalizing endovascular stenting in renal artery disease regardless of the etiology. Renal artery entrapment must be kept in mind as a possible cause of renal artery stenosis. Treatment of compressive pathologies with stenting can lead to stent failure. Surgery remains the best approach for the treatment of this type of lesion.

Laparoscopic treatment of renal artery entrapment

Renal artery entrapment by the diaphragmatic crus is a very infrequent cause of renovascular hypertension. We present the case of a young man who was assigned to our hospital with arterial hypertension and stenosis of the left renal artery. Extrinsic compression was diagnosed by duplex ultrasound and magnetic resonance angiography. We performed laparoscopic decompression using the transperitoneal retrorenal approach. Antihypertensive medication could be stopped thereafter and duplex ultrasound revealed a normal blood flow to the left renal artery. We therefore propose laparoscopic treatment of left renal artery entrapment as a minimally-invasive alternative to open surgery.

Left main renal artery entrapment by diaphragmatic crura: spiral CT angiography

Entrapment of renal artery by the diaphragmatic crus is a rare cause of renal artery stenosis. Spiral computed tomography angiography provides a definitive diagnosis and shows the precise relationship of the artery to the diaphragmatic crus. The authors present a case of hypertension developing in a young 20-year-old female due to entrapment of the left renal artery by the diaphragmatic crus. This condition should be considered in young hypertensive patients with renal artery stenosis without cardiovascular risk factors.

Compression of the left renal artery and celiac trunk by diaphragmatic crura

Symptomatic compression of the celiac trunk by crura of the diaphragm is a rare disorder. Even more infrequent external compression of renal arteries is found. Although the indication for surgical therapy is controversially discussed in the literature for celiac artery compression syndrome, it is unequivocally for renal artery entrapment. We present the case of a young woman who was assigned to our hospital with arterial hypertension and stenosis of the left renal artery. After percutaneous transluminal angioplasty was performed, immediate recoil occurred. Therefore, the suspicion of entrapment by diaphragmatic crura was expressed. Additionally performed diagnostic procedures including computed tomography (CT)-angiography verified our suspicion. Surgical decompression of both vessels was successfully performed.

Treatment of hypertension from renal artery entrapment by percutaneous CT-guided botulinum toxin injection into diaphragmatic crus as alternative to surgery and stenting

OBJECTIVE

Our objective was to describe the technique and outcome of CT-guided injection of botulinum toxin into the diaphragmatic crus in a patient with hypertension caused by left diaphragmatic crus compression of the left renal artery.

CONCLUSION

After the procedure, the patient's hypertension disappeared. We propose this technique, which directly targets inhibition of overactivity of the diaphragmatic crus, for treatment of hypertension caused by diaphragmatic compression of the renal artery as an alternative to surgery and renal artery stenting.

Bilateral Renal Artery Entrapment by Diaphragmatic Crura

We present the case of a young man with compression of both renal arteries by the crura of the diaphragm. Correct diagnosis of renal artery entrapment is difficult but crucial. The investigations rely on an high index of suspicion and include Doppler ultrasound and spiral computed tomography angiography, which permits visualization of the diaphragm and its relationships with the aorta. This pathology, unlike common renal artery stenoses, requires surgical decompression and sometimes aortorenal bypass graft.

In vivo MR angiographic quantification of axial and twisting deformations of the superficial femoral artery resulting from maximum hip and knee flexion

PURPOSE

The goal of this study was to quantify in vivo deformations of the superficial femoral artery (SFA) during maximum knee and hip flexion with use of magnetic resonance (MR) angiography to improve description of the complex, dynamic SFA environment.

MATERIALS AND METHODS

Contrast medium-enhanced MR angiography was performed on the leg vasculature of eight healthy adults in the supine and fetal positions. The SFA was defined as the centerline path of the iliofemoral segment from the profunda femoris to the descending genicular artery. Deformations that resulted from flexion from the supine position to the fetal position were quantified with the SFA path and its branches.

RESULTS

Fourteen SFAs shortened from the supine position to fetal position, whereas two lengthened. Six of eight left SFAs twisted counterclockwise, and seven of eight right SFAs twisted clockwise. Straightness percentages for supine and fetal SFAs were 99.1%+/-0.4% and 98.7%+/-0.6%, respectively. From the supine position to the fetal position, the SFA shortened 13%+/-11% (P<.001) and twisted 60 degrees+/-34 degrees (P<.001). SFA arc length and percent shortening were strongly correlated (r>.8) between left and right limbs; however, no significant correlation existed for SFA twist angle.

CONCLUSIONS

Complex and varying vascular and muscular anatomy among study participants made SFA lengths and deformations from the supine position to the fetal position unpredictable a priori; however, there were strong symmetries between left and right SFAs in terms of arc length, length change, and direction of twist. The data show that, from the supine position to the fetal position, the SFA tended to shorten and twist substantially, suggesting these as possible fracture mechanisms and also providing important parameters for stent design.

Renal artery entrapment by the diaphragmatic crus

The aim of this study is to describe renal artery entrapment (RAE) by the diaphragmatic crus and to elucidate the diagnostic and therapeutic approach to this entity. From 1995 to 2002, 15 patients (mean age 65) were found to have a RAE. They were investigated by CT scan (n=14) and/or MRA (n=2) for hypertension (n=7), chronic renal insufficiency (n=4) or aneurysms (n=4). The right (n=11) or the left (n=4) renal artery (RA) was involved. The compression was ostial (n=8) or truncal (n=7), and was > or = 50% in eight cases. The course of the RA along the aorta on angiographic views (n=8) or a concentric ostial stenosis in a patient free of atheromatous lesions (n=7) were two findings suggestive of an RAE. Seven RAEs were indicated for treatment but only three were treated, by mean of stenting. Among the latter, two stents were patent at 6-month follow-up and one evolved to restenosis because of a stent fracture. RAEs may be suspected on angiographic views and proved by cross-sectional imaging because of specific imaging features. It is of importance to detect this etiology of RA stenosis because angioplasty with stenting is probably not always advisable.