Incidence and effect of bare suprarenal stent struts crossing renal ostia following EVAR.

OBJECTIVES: The incidence and effect of bare stent struts crossing the renal ostia following endovascular aortic aneurysm repair with the Talent stent-graft is not known. The study aims to establish the incidence in which bare stent struts cross the renal ostia and to assess any associated effects on renal function. METHODS: Fifty-five patients (51 men, mean age 73 years, range 57-90) who had endovascular repair of their abdominal aortic aneurysms with a Talent suprarenal stent-graft were included in the study. Patients were scanned at a variety of follow-up periods (median 24 months, range 3-102). The relationship between the bare stent struts and the renal ostia, together with renal function were retrospectively recorded. The presence and location of the bare stent struts was assessed using CT virtual intravascular endoscopy (CT VIE). Struts were defined as being absent, peripherally located or in the central channel of the renal ostia. Renal function was assessed from glomerular filtration rates (GFR) derived from serum creatinine levels and the Cockcroft and Gault formula. RESULTS: A total of 109 renal ostia were evaluated by CT VIE with one patient having a previous nephrectomy. Bare stent struts crossed 1 renal ostium in 22 (40%) patients and bilateral ostia in 5 (9%) patients. Of the 109 ostia assessed, 15 (14%) ostia were crossed centrally and 17 (16%) had struts crossing the ostium peripherally. There were no statistically significant differences in the change between pre-operative GFR and latest GFR in the group without any strut involvement (6 mLs/min +/- 7 mLs/min) and the group with struts crossing one or both renal ostia (2 mLs/min +/- 9 mLs/min; p > .05). CONCLUSION: Peripheral or central coverage of renal ostia by bare stent struts occurs in a third of all renal arteries following EVAR. Crossing of renal ostia by bare stent struts does not affect follow-up GFR.     

Suprarenal fixation of endovascular aortic stent grafts: assessment of medium-term to long-term renal function by analysis of juxtarenal stent morphology

OBJECTIVE: The effect of suprarenal stent fixation during endovascular aortic aneurysm repair (EVAR) on renal function remains unclear. A unique validated three-dimensional intraluminal imaging technique was used to analyze the effect of suprarenal stent position relative to renal artery orifices. Also analyzed was its medium-term to long-term effects on renal function. METHODS: The study cohort comprised 29 of 34 consecutive patients who underwent EVAR with the Zenith endograft system from September 1999 to March 2002 at a single institution. The precise locations of the uncovered suprarenal stent struts were assessed by a virtual endoscopic imaging technique. Anatomic and quantitative categorization of patients was made according to the configuration of uncovered stent struts across the renal artery ostia (RAO). The anatomic subgroups were defined as struts located centrally or peripherally across both RAO. The quantitative subgroups were defined as RAO crossed by multiple struts, a solitary strut, or no struts. The subgroups were compared for their renal function, as assessed by temporal measurements of serum creatinine concentration and creatinine clearance, and renal parenchymal perfusion defects, as assessed using contrast-enhanced computed tomography (CT). RESULTS: Mean follow-up was 52.7 months. Separate subgroup analysis for both anatomic and quantitative configurations did not demonstrate any significant difference in renal function between the different strut permutations (P > .05). Follow-up imaging confirmed one case of renal infarction secondary to an occluded accessory renal artery, although this patient had normal serum creatinine levels. CONCLUSION: RAO coverage by suprarenal uncovered stents does not appear to have a significant effect on renal function as evaluated by creatinine measurements in patients with normal preoperative renal function.     

The effects of crossing porcine renal artery ostia with various endovascular stents.

OBJECTIVES: To compare the effects of crossing renal artery ostia with various stents. METHODS: The renal artery ostia of 24 large white pigs were covered with a Wallstent (nine ostia), a Palmaz stent (nine ostia) and a Memotherm stent (13 ostia). After an interval of 6-15 weeks, aortography, renal pressure and blood samples were performed and the pigs then sacrificed for histological examination. RESULTS: Histological examination revealed an organised collagen matrix with endothelial cells covering the struts in contact with the aorta. This occurred with all stents but was most organised with the Wallstent. This matrix did not involve the renal artery ostia crossed by Wallstents, but in one Palmaz stent and in 12/13 Memotherm stents, a disorganised acellular matrix caused partial ostial occlusion. There was no mean fall in renal artery pressure but traces were damped in 8/13 cases of partial occlusion. There was a rise in serum creatinine in two cases using the Palmaz stent. CONCLUSIONS: Covering renal arteries with the Wallstent appears to be safe in the short-term. Placement of stents with larger struts across renal arteries will require imaging methods, such as intravascular ultrasound (IVUS) to ensure that the ostia are not obstructed.     

Computed tomography virtual intravascular endoscopy in the evaluation of fenestrated stent graft repair of abdominal aortic aneurysms

Background: This study aimed to investigate the diagnostic value of computed tomography virtual intravascular endoscopy (VIE) in the follow‐up of patients with abdominal aortic aneurysm (AAA) treated with fenestrated stent grafts. Methods: A total of 19 patients (17 males and 2 females; mean age: 75 years) with AAA undergoing fenestrated stent grafts were retrospectively studied. Pre‐ and post‐fenestration computed tomography data were reconstructed for the generation of VIE images of aortic ostia and fenestrated stents and compared with two‐dimensional axial and multiplanar reformation (MPR) images. Serum creatinine was measured pre and post fenestration to evaluate the renal function. Results: The mean intra‐aortic length measured by VIE, two‐dimensional axial and MPR were 4.7, 4.4 and 4.6 mm, respectively, for the right renal stent; 5.0, 4.9 and 5.0 mm, respectively, for the left renal stent; and 5.9, 6.0 and 6.0 mm, respectively, for the superior mesenteric artery stent. Comparisons of these measurements did not show significant difference (P > 0.05). The mean diameters of renal artery ostia measured on VIE visualization pre and post fenestration were 9.2 × 8.3 and 10 × 8.9 mm for the right renal ostium; 8.3 × 7.1 and 9.9 × 8.9 mm for the left renal ostium, with significant changes observed (P < 0.01). No renal dysfunction was observed in this group. Conclusion: VIE is a valuable visualization tool in the follow‐up of fenestrated stent graft repair of AAA by providing intraluminal appearance of fenestrated stents and measuring the length of stent protrusion.     

Revascularization for coronary ostial stenosis in Takayasu's disease with calcified aorta.

A case in which a patient with stenoses of the right and left coronary ostia and heavy calcification of the aorta caused by Takayasu's disease was successfully treated by coronary artery bypass grafting is presented. The aortic ends of the two grafts were attached to a xenopericardial patch, which was sutured into the ascending aorta. This technique can be done without fine sutures, which are required for proximal anastomosis of a vein graft, and may reduce the risk of ostial stenosis.     

Effect of suprarenal versus infrarenal aortic endograft fixation on renal function and renal artery patency: a comparative study with intermediate follow-up

PURPOSE: Suprarenal fixation of aortic endografts appears to be a safe option in patients with a short or conical proximal aortic neck. However, concern persists regarding the long-term effect on renal function when renal artery ostia are crossed by the uncovered stent. We investigated the effect of suprarenal versus infrarenal endograft fixation on renal function and renal artery patency after endovascular aortic aneurysm repair. METHODS: Records of 91 patients who underwent endovascular aortic aneurysm repair with a modular bifurcated stent graft between November 1999 and January 2002 were reviewed retrospectively. Two patients receiving dialysis because of chronic renal failure were excluded. Infrarenal fixation was used in 57 patients (group 1), and suprarenal fixation was used in 32 patients (group 2). In two patients in group 1 a Gianturco Z stent was inserted transrenally because of intraoperative proximal type I endoleak, and data for these patients were excluded from analysis. Follow-up evaluation was performed at 1, 6, and 12 months, and yearly thereafter, and included clinical assessment, measurement of serum creatinine concentration (SCr), and computed tomography angiography, per standard protocol. Median follow-up was 12 months (range, 1-36 months). RESULTS: There was no statistically significant difference in patient demographic data, aneurysm size, or preoperative risk factors. Median SCr was significantly higher in group 2 (suprarenal fixation) than in group 1 (infrarenal fixation) preoperatively (1.2 mg/dL [range, 0.6-2.3 mg/dL] vs 0.9 mg/dL [range, 0.6-1.9 mg/dL], P =.008) and at 1 month postoperatively (1.1 mg/dL [range, 0.8-5.6 mg/dL] vs 1.0 mg/dL [range, 0.6-2.1 mg/dL], P =.045). There was a significant increase in median SCr in both groups at 1 month postoperatively (group 1, 1.0 mg/dL [range, 0.6-2.1 mg/dL], P =.05; group 2, 1.1 mg/dL [range, 0.8-5.6 mg/dL] [mean SCr, 1.35 mg/dL vs 1.15 mg/dL, respectively], P <.05). In group 1 SCr was increased significantly at 6 and 12 months (P <.001), whereas in group 2 SCr also increased at 6 and 12 months, but not significantly. The change in SCr over time was not significantly different between the two groups. In two of 32 patients in group 2, renal artery occlusion developed, associated with perfusion defects in renal parenchyma and persistently elevated SCr. Analysis of renal artery patency did not demonstrate any association between patency and treatment. No patient developed hypertension during follow-up. CONCLUSIONS: Suprarenal endograft fixation does not lead to significant renal dysfunction, and renal artery occlusion is uncommon within 12 months. A larger study with longer follow-up is essential to determine overall effects on renal function and renal artery patency.     

Feasibility of renal artery stenting before, during, and after endovascular aneurysm repair with suprarenal fixation endograft

Suprarenal fixation by means of proximal bare stent may help prevent endograft migration and proximal endoleak. It seems not to compromise renal perfusion and function; however, it is still unclear whether its presence is in conflict with stenting of the renal arteries to treat associated renal stenosis. We report five cases of renal artery stenting performed before, at the same time, or after endovascular treatment of abdominal aortic aneurysm with a suprarenal fixation endograft (Zenith; Cook, Biaverskov, Denmark). Suprarenal fixation endograft seems not to affect renal artery stenting regardless the timing of the procedure.     

Endarterectomy and graft replacement of severely calcified (porcelain) ascending aorta with coronary ostial involvement in a patient requiring aortic valve replacement.

We report a successful aortic valve replacement within an extensively calcified (porcelain) aorta, involving the left coronary artery ostium. Clamping such an aorta can result in embolization, dissection, and mural laceration. A 72-year-old female presented with a severely calcified and stenotic aortic valve with a peak pressure gradient of 101 mmHg. Computed tomography demonstrated extensive calcification of the ascending aorta. Coronary angiogram showed a 50% ostial left coronary artery stenosis. Under deep hypothermic circulatory arrest, the aorta was transected at the proximal arch and distal graft anastomosis was performed. This was followed by endarterectomy of the porcelain ascending aorta and the left coronary ostium. Aortic valve replacement, proximal aortic graft anastomosis, and a coronary artery bypass grafting (CABG) with the left internal thoracic artery (LITA) anastomosed to the left anterior descending artery (LAD) were then performed in a sequential manner.     

Placement of a fenestrated Palmaz stent across the renal arteries. Feasibility and outcome in an animal study.

OBJECTIVES: To investigate the feasibility of placing stents across renal arteries. Design we have studied in pigs: (i) the feasibility of accurately placing a fenestrated stent in front of one renal ostium; (ii) the short-term effects on renal arteries and function after the placement of such a fenestrated stent. MATERIALS AND METHODS: Eight fenestrated Palmaz stents were placed over pigs' renal ostia under fluoroscopy. Five weeks later, angiograms were performed and the animals were sacrificed. Proliferation of the healing tissues over the ostia was measured and analysed by microscopy. Serum creatinine was measured prior to all angiograms and at 5 weeks. RESULTS: All eight stents were correctly placed. One stent later migrated and was excluded from the study. One pig died at day 1. Gross examination confirmed the correct placement of the fenestrations in four pigs out of seven (57%). In the six remaining pigs, at 5 weeks, there was no angiographic evidence of stent misplacement and all the kidneys were fully perfused. Nine renal ostia were covered by struts and neointima with a mean area of coverage of 38+/-5% altogether. No tissue proliferation was observed over the three renal ostia located in front of the fenestration. Serum creatinine did not significantly increase at 5 weeks. CONCLUSION: Creating a fenestration in a stent for renal arteries may be worth while in order to avoid neointimal covering of the renal ostia. However, accurate placement of such a fenestrated stent remains a difficult task.     

Surgical angioplasty of isolated left coronary ostial stenosis

A 42-year-old female had suffered from chest pain for approximately 1 month, and was admitted with unstable angina pectoris. Emergent coronary angiography showed an isolated 75% stenosis of the left coronary ostium. Repair of ostial stenosis by vein patch angioplasty was done by the transactional superior approach. Postoperative catheterization revealed an expanded left coronary orifice and the patient was discharged without any complications. We have experienced 2 other patients of isolated left coronary ostial stenosis, who had undergone double coronary artery bypass grafting. Long-term coronary angiography showed regression of ostial stenosis in 1 patient, and no progression of new lesions in either. These results suggest that direct vein patch angioplasty of the ostial lesion is an alternative procedure for isolated left coronary ostial stenosis.     

Renal interventions after abdominal aortic aneurysm repair using an aortic endograft with suprarenal fixation

BACKGROUND: Our aim was to determine whether suprarenal fixation in endografts compromises renal artery (RA) flow and whether subsequent RA intervention is precluded by the stent struts. METHODS: Prospectively acquired data from 104 patients with endovascular aneurysm repair (EVAR) of an abdominal aortic aneurysm using the Zenith endograft (Cook, Inc., Bloomington, IN) were analyzed. The Zenith device uses a 26-mm, uncovered, barbed Z stent for suprarenal function. RESULTS: No RA stenosis, occlusion, or infarction resulted from the suprarenal stent. In 3 of 104 (2.9%) patients, RA compromise (2 stenoses, 1 occlusion) was caused by impingement of graft material on the lowermost RA. The 2 RA stenoses were stented successfully at 1 and 7 months post-EVAR. Six of 104 (5.8%) patients developed late stenoses unrelated to the endograft: all were stented successfully from 19 to 36 months after EVAR. One patient with severe RA stenosis had balloon angioplasty pre-EVAR and then was stented electively 6 weeks post-EVAR. CONCLUSIONS: Our data show that the suprarenal fixation of the Zenith aortic endograft does not cause RA stenosis, occlusion, or infarction, nor does it preclude post-EVAR renal artery intervention.     

Mid-term outcome of surgical coronary ostial plasty: our experience

The conventional coronary artery bypass procedure that uses venous or arterial conduit for isolated critical stenosis of the left main coronary artery (LMCA) restores a less physiological perfusion of the myocardium and uses an appreciable length of bypass material. Coronary ostial plasty has been described as an alternative surgical technique in proximal obstructive coronary artery disease without calcifications. Here we report 23 patients (15 males and 8 females aged 37-78 years; mean age 57 years) who underwent surgical ostial plasty. Ostial reconstruction with fresh pericardial patch was performed in all patients: 15 patients with LMCA stenosis, 6 patients with right coronary (RC) ostial stenosis, and 2 patients with both RC artery and LMCA stenosis. In seven cases, coronary artery bypass grafting was added for contralateral distal stenosis with a total of five arterial conduits and six venous grafts. One patient died; the ostial plasty and grafts were patent at necropsy. Thallium-201 myocardial scintigraphy under stress at 30 days to 6 months after operation demonstrated good myocardial perfusion in 21 of 22 patients. Coronary angiography at follow-up (49 +/- 8 months) demonstrated good surgical ostial plasty results in 21 of 22 patients and good coronary flow in 19 of 22 patients; angiographic study at mid-term follow-up revealed only one failure of the surgical ostial plasty technique associated with venous graft obstruction. In 2 other patients CABG failure due to venous graft obstruction (1 patient) or distal stenotic lesions of the left coronary artery (1 patient) was noted. The overall successful outcome of the surgical ostial plasty was 22 of 23. We believe that surgical angioplasty of the coronary ostia may be used in the presence of proximal noncalcified obstructive lesions as an alternative technique, which offers a more physiological revascularization; it also spares grafting material and allows subsequent percutaneous transluminal angioplasty or coronary artery bypass surgery.     

Regression of left main coronary ostium stenosis after surgical revascularization and steroid therapy.

We describe a patient in whom stenosis of the left main coronary ostium completely regressed after steroid treatment following surgical revascularization. A 46-year-old woman with unstable angina underwent double coronary artery bypass grafting. Although she did not fulfill diagnostic criteria for Takayasu's disease, we began postoperative steroid therapy on postoperative day 14 based on clinical manifestations and histological findings. Coronary angiography 33 days after surgery showed the ostial stenosis of the left main coronary artery had disappeared. Steroid therapy for suspected Takayasu's disease should be considered even after surgical revascularization.     

Coronary ostial stenosis

From January 1970 to December 1986, 2.7% (228/8509) of all patients having coronary artery bypass grafting had atherosclerotic coronary ostial stenosis of 50% or more. There were 126 males (55%) and 102 females (45%) with mean ages of 60.2 +/- 9.0 and 59.2 +/- 10.2 years (P = NS), respectively. The left ostium was involved in 176 (77.2%) patients, the right in 41 (18.0%) and both in 11 (4.8%). Isolated ostial stenosis (no associated coronary disease of 50% or more) was present in 38/228 (17%) with females predominating (29/38, 76%). Isolated ostial stenosis occurred more frequently on the right (10/41, 25%) than on the left (18/176, 16%). Associated coronary disease occurred in a single vessel in 42 patients, in two vessels in 72 and in three vessels in 76 resulting in a mean of 2.0 diseased vessels per patient. If patients with isolated ostial stenosis are excluded there were 2.3 diseased arteries per patient. There were 687 grafts performed in these patients, an average of 2.3 grafts per patient. One month surgical mortality was 4.8% (11/228), but has been 2% (2/104) in the last 4 years. Nine of 27 late deaths were noncardiac with a mean follow-up of 49 +/- 44 months. Ostial stenosis is hemodynamically equivalent to left main disease when the left ostium is involved. Symptomatic ostial lesions, whether right or left, require operative therapy.     

Coronary revascularization after arterial switch operation.

We report two cases presenting bilateral coronary artery obstruction after arterial switch operation. The first patient underwent bilateral internal thoracic artery grafting to the left and right coronary arteries. The other patient, presenting a single coronary ostium, underwent surgical coronary ostial angioplasty in concomitance to proximal arterioplasty of both coronary arteries employing a single "pantaloon" shape autologous pericardial patch. Both patients survived and, at 1 year and 9 months after the coronary revascularization procedures, the coronary angiography demonstrated a good patency of the internal thoracic grafts and excellent ostial plasty results, respectively. A complete literature review of patients undergoing different coronary revascularization procedures after arterial switch operation is reported.     

Repair of an anomalous left coronary artery

We describe a patient with an anomalous single coronary artery who presented with a syndrome of atypical chest pain. Coronary angiography revealed a single right coronary ostium, with a narrowed left coronary artery originating at the right coronary ostium. The proximal portion of the left coronary artery that was narrowed was noted to run in the aortic wall. We describe the operative management of this patient using ostial remodeling.     

Bilateral coronary ostial stenoses with aortic regurgitation in a patient with syphilitic aortitis

Syphilitic aortitis is now rare in developed countries and is sometimes overlooked. A 61-year-old man with bilateral coronary ostial stenoses (#5:90%, #1:99%) and Sellers III/IV aortic regugitatioin (AR) induced by syphilitic aortitis presented with chest pain. Preoperative rapid plasma reagin titer and Treponema pallidum hemagglutination test were strongly positive, 256 fold and 191.25 C.O.I., respectively. Aortic valve replacement (AVR) and coronary artery bypass grafting (CABG) with bilateral internal thoracic arteries (ITA) was performed successfully. The angiographic features as follows: 1) coronary artery stenosis is generally limited to the ostia, 2) the grade of stenosis is almost always more than 90%, 3) AR is frequently associated with coronary ostial stenosis. CABG should be performed with ITA, not saphenous vein grafts, to avoid occlusion of the ostium of the saphenous vein graft by syphilitic aortitis. Retrograde cardioplegia should be performed if ostial stenosis is severe.     

Severe cardiomyopathy caused by a critically stenosed anomalous left coronary artery ostium originating in the left ventricle

We report a case of a 44‐year‐old patient presenting with new‐onset severe decompensated congestive heart failure, which was refractory to aggressive inpatient medical treatment. Left ventricular ejection fraction was 16%. Radiological investigations revealed the presence of an anomalous subannular origin of the left coronary artery, with an associated 95% ostial stenosis. The artery was supplied by collaterals from the right coronary system. This included a proximal collateral from the right marginal artery, which had its own separate ostium in the right aortic sinus. A diagnosis of ischemic dilated cardiomyopathy was made. The patient successfully underwent urgent coronary artery bypass grafting with a view to improve his left ventricular function and congestive heart failure symptoms.     

Aortic debranching for descending thoracic aortic aneurysm repair by stent grafts

Endovascular repair of a descending thoracic aortic aneurysm may result in covering the ostia of the left carotid or left subclavian artery for proper proximal landing zones, and the celiac artery or superior mesenteric artery ostia in the abdomen for distal landing zones. To prevent possible complications of occluding the ostia of these vessels, the authors performed an innominate to left common carotid and left subclavian artery bypass as the first procedure in one patient. In the second patient they performed an aortoceliac and aortomesenteric bypass before stent graft placement. The stent graft repair of the descending thoracic aortic aneurysm was performed subsequently in both patients. This aortic debranching provides subsequent proper placement of thoracic stent grafts.     

Successful treatment in a patient with Takayasu's arteritis and Marfan syndrome

We report an unusual case of concomitant Takayasu's arteritis and Marfan syndrome manifesting left main coronary ostial obstruction and annuloaortic ectasia. Simultaneous surgical treatment consisting of left coronary ostium endarterectomy, coronary artery bypass grafting, and Bentall operation was performed. This case is unique in that the cardiovascular manifestations of Takayasu's arteritis and Marfan syndrome were both simultaneously presented and surgically treated.