John Ligush

An aortic aneurysm model for the evaluation of endovascular exclusion prostheses

PURPOSE The purpose of this study was to develop an aortic aneurysm (AA) model with a predictable tendency for rupture for the evaluation of the efficacy of endovascular prostheses in preventing rupture and their long-term outcome after implantation. METHODS An infrarenal AA measuring two to three times the diameter of the proximal aorta was created in 18 dogs with a full-thickness patch of jejunum. Seven dogs were allowed to survive without aneurysm exclusion. In 11 dogs the aneurysm was immediately excluded with a stented 8 mm Dacron graft mounted in a 14F delivery system introduced through the femoral artery with aortographic guidance. The pressure differential between the aorta and the excluded aneurysm was measured, and angiography, necropsy, and histologic examination were performed at 3- and 6-month survival. RESULTS All animals survived aneurysm implantation. Without aneurysm exclusion, six dogs died of rupture within 1 to 6 days of surgery. In three dogs the exclusion failed because of graft-to-aorta size mismatch or misplacement demonstrated on angiography and by a low pressure differential between the aorta and the aneurysm (< 5 mm Hg); all three dogs died of rupture within 4 days. In eight dogs the aneurysm was successfully excluded on the basis of angiography results, with a mean aorta-to-aneurysm pressure differential of 51 mm Hg. Two dogs were killed at 1 and 6 days after surgery because of paraplegia produced by graft thrombosis because of kinking but without evidence of aneurysm rupture. Six dogs survived on a long-term basis, and angiography and necropsy performed at 3 and 6 months revealed patent grafts without migration, reduction in aneurysm size, no flow in the excluded lumbar arteries in five of six animals, and complete incorporation of Dacron graft and stents. No evidence of graft infection was found in any animal. The survival rate was significantly better (p < 0.023) in dogs with successfully excluded aneurysms (n = 6) compared with that in dogs without exclusion or with failed aneurysm exclusion (n = 7). CONCLUSION This aneurysm model demonstrates that without effective aneurysm exclusion all animals die of rupture and that successfully placed endovascular prostheses can prevent AA rupture with long-term graft patency and stability. Endovascular aortic Dacron grafts in dogs undergo complete incorporation at 3 months from implantation. This aneurysm model is useful for the evaluation of endovascular devices designed for the treatment of AAs.

Duplex ultrasound scanning defines operative strategies for patients with limb-threatening ischemia

PURPOSE To characterize the accuracy of color-flow duplex ultrasound (DUS) in planning lower extremity revascularization procedures, we prospectively compared operations predicted by means of DUS arterial scanning (DUSAS) and operations predicted by means of conventional angiography (CA) with actual operations performed in 36 patients undergoing 40 vascular reconstructions for critical (grade II/III) lower extremity ischemia. METHODS All patients were examined with lower extremity DUSAS followed by CA. DUSAS was performed from the aorta to the pedal vessels of the affected extremity. Adequacy of inflow was assessed, and the best distal target vessel with continuous, unobstructed flow was defined. An operative prediction was made and recorded based upon the DUSAS findings, and in a blinded fashion, based upon subsequent CA. The McNemar test for comparing correlated proportions was applied to test for the statistical significance of the difference (P < .05) between correct operations predicted by DUSAS and CA. RESULTS Of the actual operations performed, 83% were correctly predicted by means of DUSAS (95% CI; range, 77% to 89%). Seven operations were incorrectly predicted with DUSAS. Of the actual operations performed, 90% were correctly predicted by means of CA (95% CI; range, 81% to 99%). Four operations were incorrectly predicted with CA. The McNemar test determined that the difference between correct operations predicted by means of DUSAS and correct operations predicted by means of CA was not statistically significant (P = .50). CONCLUSIONS With few exceptions, DUSAS can be used to reliably predict infrainguinal reconstruction strategies. Vessels defined as adequate with DUSAS are rarely unfit for bypass. Prospective investigation of lower extremity revascularization based solely upon DUSAS is warranted.

Surgery after failed percutaneous renal artery angioplasty

PURPOSE This retrospective review describes the surgical management of 51 patients after failed percutaneous renal artery angioplasty (F-PTRA). METHODS From January 1987 through June 1998, 51 consecutive patients underwent surgical repair of either atherosclerotic (32 patients) or fibromuscular dysplastic (FMD; 19 patients) renovascular vascular disease after F-PTRA. These patients form the basis of this report. Surgical repair was performed for hypertension (29 patients with atherosclerosis: mean blood pressure, 205 +/- 34/110 +/- 23 mm Hg; 18 patients with FMD: mean blood pressure, 194 +/- 24/118 +/- 18 mm Hg) or ischemic nephropathy (20 patients with atherosclerosis: mean serum creatinine level, 2.0 +/- 0.8 mg/dL; three patients with FMD: mean serum creatinine level, 2.0 +/- 1.1 mg/dL). Emergency operation was required in four patients for acute renal artery thrombosis (one patient with atherosclerosis, one patient with FMD), renal artery rupture (one patient with atherosclerosis), or infected pseudoaneurysm (one patient with atherosclerosis). Operative management, blood pressure and renal function response to operation, and dialysis-free survival rate were examined and compared with 487 patients (441 patients with atherosclerosis, 46 patients with FMD) treated by operation alone. RESULTS Among the patients with atherosclerotic renovascular disease, there were three postoperative deaths (9.4%) after repair for F-PTRA. Secondary operative repair was associated with emergent repair or nephrectomy in 16% of cases, while more extensive renal artery exposure and more complex operative management was required in 50% of patients with atherosclerosis and 65% of patients with FMD repaired electively. Among the 28 operative survivors with hypertension and atherosclerotic renovascular disease, blood pressure benefit after F-PTRA was significantly lower when compared with patients with atherosclerosis who underwent treatment with operation only (57% vs 89%; P <.001). However, blood pressure benefit in the 19 patients with FMD did not differ (89% vs 96%). Among the 28 patients with atherosclerosis, preoperative estimated glomerular filtration rate (EGFR) as compared with postoperative EGFR was significantly increased (47.4 +/- 4.2 mL/min/1.73m(2) vs 56. 6 +/- 5.1 mL/min/1.73m(2); P =.002). However, EGFR prior to PTRA was not significantly different from postoperative EGFR (51.6 +/- 3.4 mL/min/1.73m(2) vs 56.6 +/- 4.9 mL/min/1.73m(2); P =.121). As compared with patients with atherosclerosis who underwent treatment with operation alone, there was no difference in the dialysis-free survival rate. CONCLUSION Operative repair after F-PTRA was altered in 59% of the patients with atherosclerosis and in 68% of patients with FMD. Blood pressure benefit for patients with FMD was unchanged after F-PTRA. However, the blood pressure benefit was significantly decreased among patients with atherosclerosis. Decreased EGFR after F-PTRA was recovered with operative renal artery repair. However, postoperative EGFR as compared with EGFR prior to PTRA was unchanged. Blood pressure and renal function response after F-PTRA for atherosclerotic renovascular disease warrants further study.

Infected renal artery pseudoaneurysm and mycotic aortic aneurysm after percutaneous transluminal renal artery angioplasty and stent placement in a patient with a solitary kidney

Endovascular infections after percutaneous transluminal renal angioplasty with stenting (PTRAS) are rarely reported. Because strict longitudinal follow-up of patients undergoing PTRAS is lacking, the true incidence of such complications remains obscure. We report the first case of a patient with an infected renal artery pseudoaneurysm and de novo mycotic aortic aneurysm after PTRAS. This case serves to illustrate several important points, including (1) the retrieval of renal function in patients with renal artery occlusion, (2) the pathogenesis of infection after PTRAS, (3) the diagnosis and management of endovascular infection after percutaneous vascular intervention, and (4) recommendations for periprocedural antibiotic prophylaxis during PTRAS.

Management and outcome of chronic atherosclerotic infrarenal aortic occlusion

PURPOSE To evaluate the management and outcome of chronic atherosclerotic infrarenal aortic occlusion (IRAO), a review of 48 patients who were treated for angiographically documented IRAO between January 1980 and December 1994 was undertaken. Mean follow-up was 45 months. Mean age was 57 years (range, 33 to 88 years). Forty-seven patients were heavy smokers. Symptoms included claudication in 81%, rest pain in 25%, and tissue loss in 15%. Impotence was documented in 73% of men. Associated arterial disease included inferior mesenteric artery occlusion in 31 patients, renal artery stenosis or occlusion in 12, superior mesenteric artery stenosis in two, and celiac artery stenosis in one. METHODS Forty inflow procedures were performed, including 17 thoracobifemoral bypass (TBF) procedures, 15 aortobifemoral/iliac bypass (ABFI) procedures, and eight axillobifemoral bypass (AXBF) procedures. Eight patients were managed without surgery. The thoracic aorta was chosen as the inflow source in 17 patients because of previous abdominal aortic surgery in eight, poor status of the abdominal aorta in eight, and horseshoe kidney in one. RESULTS The overall operative mortality rate was 5%, and the perioperative morbidity rate was 18%. There was no statistical difference in perioperative mortality and morbidity rates among the operative groups. The five-year survival rate (life-table) for all IRAO patients was 67%. TBF and ABFI revascularization procedures yielded 5-year patency rates of 71% and 79%, respectively (p < 0.05). All eight patients who underwent AXBF died or had occluded grafts at 3 years after surgery. Two-year patency rates (life-table) for TBF, ABFI, and AXBF were 92%, 92%, and 44%, respectively. The AXBF patency rate was significantly inferior to those of TBF and ABFI (p < 0.05). Changes in ankle-brachial indexes after TBF or ABFI were similar, but were significantly greater than changes after AXBF (p < 0.05). Three patients in the nonoperative group died, and two underwent major amputation. Acute renal failure did not occur in our study population. Follow-up creatinine levels > 2.0 mg/dl were documented in three operative patients and in one nonoperative patient, and none required dialysis. CONCLUSIONS In patients who have IRAO, aorta-based inflow procedures are superior to AXBF both in hemodynamic outcome and in patency rates. Treatment of IRAO with TBF or ABFI yields similar long-term results; the descending thoracic aorta represents an excellent inflow alternative to the abdominal aorta. Clinically significant renal impairment is rarely associated with IRAO. Nonoperative management of IRAO is associated with an increased mortality rate and a high rate of limb loss.

Renal artery repair: consequence of operative failures.

OBJECTIVE This report examines the blood pressure and renal function response in 20 consecutive patients after secondary renal revascularization following failed operative repair. SUMMARY BACKGROUND DATA Most reports describing operative failure of renal artery (RA) repair emphasize the technical aspects of redo RA reconstruction and the immediate blood-pressure response to secondary operation. This report examines the eventual renal function and estimated survival after secondary intervention. METHODS Primary methods of RA reconstruction, primary blood pressure and renal function responses, and causes of failed RA repair were defined for 20 patients requiring reoperation for recurrent hypertension or renal insufficiency. These parameters were compared with secondary procedures and eventual blood pressure and renal function response. The eventual outcome for these 20 patients was compared with 514 patients managed by primary renal revascularization during the same period. RESULTS Failure of primary RA repair correlated with complex fibromuscular dysplasia requiring branch ex vivo reconstruction (p = 0.020). RA thrombosis frequently required nephrectomy (83%), whereas RA stenosis was successfully reconstructed (91 %; p = 0.001). Primary and secondary blood-pressure responses were equivalent (94% vs. 95% cured or improved); however, primary and eventual renal function responses differed significantly (p = 0.015), with seven patients dialysis-dependent on follow-up. Eventual dialysis dependence was associated with preoperative azotemia (p = 0.022), bilateral failure of primary RA repair (p = 0.007), and an increased risk of follow-up death (p = 0.002). Considering all 534 patients, failed RA repair demonstrated a significant and independent association with eventual dialysis dependence and decreased dialysis-free survival. CONCLUSIONS Contemporary rates of reoperation after surgical RA repair are low. In properly selected patients, beneficial blood-pressure response is reliably observed after both primary and secondary operative procedures. However, secondary procedures are associated with a significant and independent risk of eventual dialysis dependence.

Innominate artery occlusive disease: Management with central reconstructive techniques

BACKGROUND The purpose of this study was to review our experience with central vascular reconstruction for innominate artery occlusive disease. Eighteen patients underwent central reconstruction for innominate artery (IA) occlusive disease during an 8-year period (1986 to 1994). Mean age was 59 years (range, 36 to 77 years). Women outnumbered men 12 to 6. All patients had symptoms including amaurosis fugax 55%, transient ischemic attacks 44%, vertebrobasilar insufficiency 44%, and arm claudication 33%. The IA was occluded in three patients and stenotic in 15. Three patients underwent previous extrathoracic bypass procedures for IA lesions that failed. METHODS Operations performed through a median sternotomy included aortocarotid bypass with reimplantation of the subclavian (n = 10) and aortoinnominate bypass (n = 7). Transection and oversewing of the IA was performed in all but one patient, in whom ligation of the IA was performed. One patient with severe chronic obstructive pulmonary disease and previous coronary artery bypass grafting underwent retrograde-transluminal IA angioplasty with endovascular stent placement via a carotid approach. Four patients underwent concomitant carotid endarterectomy). Two patients underwent concomitant coronary artery bypass grafting at the time of IA reconstruction. RESULTS There was one operative death from myocardial infarction. Perioperative morbidity included dysrrhythmia (three), respiratory insufficiency (three), subendocardial myocardial infarction (two), cerebrovascular accident with complete recovery (two), hemorrhage (one), and acute graft occlusion (one). All grafts remained patient at a mean follow-up of 21 months (range, 8 to 60 months). The only patient who underwent ligation of the IA required a subsequent revision of the IA to transection and oversewing for an embolic event at 4 months status-post aortocarotid bypass. The patient who underwent angioplasty remained asymptomatic with a patient IA at 12 months. Average length of stay for transthoracic repair was 14 days and for transluminal angioplasty 2 days. CONCLUSIONS Innominate artery bypass based on the ascending aorta is effective in providing relief of symptoms and has a high patency rate. Because of the significant morbidity, these procedures should be reserved for patients with symptoms. The IA should be transected and oversewn to prevent recurrent embolism. Transcarotid, retrograde angioplasty provides an alternative approach to stenotic lesions located in the IA or proximal common carotid artery. An aggressive approach directed at defining coronary artery disease is an invaluable adjunct to the proper treatment of this patient population.

Cryptococcal aortitis presenting as a ruptured mycotic abdominal aortic aneurysm

Mycotic processes occasionally complicate atherosclerotic aortic disease and usually require aggressive surgical therapy to control sepsis and prevent arterial rupture. Rarely, fungal organisms are responsible for primary infection of the abdominal aorta. We report the first case of Cryptococcal aortitis presenting as a ruptured abdominal aortic aneurysm. The surgical, pathologic, and microbiologic aspects of fungal aortitis are discussed.

Infected Renal Artery Pseudoaneurysm and Mycotic Aortic Aneurysm After Percutaneous Transluminal Renal Artery Angioplasty and Stent Placement in a Patient With a Solitary Kidney

Endovascular infections after percutaneous transluminal renal angioplasty with stenting (PTRAS) are rarely reported. Because strict longitudinal follow-up of patients undergoing PTRAS is lacking, the true incidence of such complications remains obscure. We report the first case of a patient with an infected renal artery pseudoaneurysm and de novo mycotic aortic aneurysm after PTRAS. This case serves to illustrate several important points, including (1) the retrieval of renal function in patients with renal artery occlusion, (2) the pathogenesis of infection after PTRAS, (3) the diagnosis and management of endovascular infection after percutaneous vascular intervention, and (4) recommendations for periprocedural antibiotic prophylaxis during PTRAS.