Sex disparities in popliteal artery aneurysms.

OBJECTIVE: Only 5% of patients with popliteal artery aneurysms (PAAs) are female. Evidence on PAA treatment and outcomes in women is therefore scarce. The POPART Registry provides one of Europe's largest data collections regarding PAA treatment. Data on clinical presentation, aneurysm morphology, and perioperative outcomes after open surgical PAA repair in women will be presented. METHODS: POPART is a multicenter, noninterventional registry for open and endovascular PAA repair, with 42 participating centers in Germany and Luxembourg. All patients aged >18 years who have been treated for PAA since 2010 are eligible for study inclusion. Data collection is based on an online electronic case report form. RESULTS: Of the 1236 PAAs, 58 (4.8%) were in women. There were no significant differences in age or cardiopulmonary comorbidities. However, female patients had a lower prevalence of contralateral PAAs and abdominal aortic aneurysms (P < .05). PAAs in women were more likely to be symptomatic before surgery (65.5% vs 49.4%; P = .017), with 19% of women presenting with acute limb ischemia (vs 11%; P = .067). Women had smaller aneurysm diameters than men (22.5 mm vs 27 mm; P = .004) and became symptomatic at smaller diameters (20 mm vs 26 mm; P = .002). Only 8.6% of women and 11.6% of men underwent endovascular aneurysm repair (P > .05); therefore, the perioperative outcome analysis focused on open surgical repair. In total, 23.5% of women and 16.9% of men developed perioperative complications (P > .05). There were no differences in major cardiovascular events (P > .05), but women showed a higher incidence of impaired wound healing (15.7% vs 7.2%; P = .05) and major amputation (5.9% vs 1.1%; P = .027). Female sex was significantly associated with the need for nonvascular reinterventions within 30 days after surgery (odds ratio: 2.48, 95% confidence interval: 1.26-4.88), whereas no significant differences in the odds for vascular reinterventions were observed (odds ratio: 1.98, 95% confidence interval: 0.68-5.77). In the multiple logistic regression model, female sex, symptomatic PAAs, poor quality of outflow vessels, and graft material other than vein graft were independently associated with perioperative reinterventions. CONCLUSIONS: Women have smaller PAAs, are more likely to be symptomatic before treatment, and are more often affected by nonvascular reinterventions in the perioperative course. As our understanding of aneurysmatic diseases in women continues to expand, sex-specific treatment strategies and screening options for women in well-selected cohorts with modified screening protocols should be continuously re-evaluated.

Long-term dilatation of polyester and expanded polytetrafluoroethylene tube grafts after open repair of infrarenal abdominal aortic aneurysms.

OBJECTIVES: Since 1995, expanded polytetrafluoroethylene (ePTFE) grafts have been implemented in open surgical repair (OSR) of abdominal aortic aneurysms (AAA) and are supposed to show less dilatation than polyester grafts. This study examined differences in graft dilatation and clinical outcome. METHODS: This single-center long-term, prospective randomized study monitored 99 consecutive patients after OSR of AAA. Implanted were 90 tube ePTFE Gore-Tex Stretch grafts, 56 tube Dacron grafts (Uni-Graft KDV, polyester, B. Braun, knitted), and 51 tube Dacron grafts (Gelseal Plus, polyester, Vascutek, triaxial knitted). Follow-up with ultrasound examination was performed at discharge, at 12 months, and at 6 years. RESULTS: Patients were a mean age of 67 years. Thirty-day mortality was 2.5% (n = 5 of 199), without significant differences among the groups. The Kaplan-Meier analysis showed 5-year survivals of 0.82 (ePTFE/Gore), 0.81 (polyester/Braun), and 0.83 (polyester/Vascutek). Mean ± standard deviation dilatation of the midgraft segment was 1% ± 5% (ePTFE/Gore), 10% ± 9% (polyester/Braun), and 7% ± 8% (polyester/Vascutek) (P ≤ .001) at discharge; 8% ± 11% (ePTFE/Gore), 24% ± 7% (polyester/Braun), and 20% ± 13% (polyester/Vascutek; P ≤ .001) after 12 months; and 19% ± 21% (ePTFE/Gore), 33% ± 22% (polyester/Braun), and 23% ± 19% (polyester/Vascutek; (P ≤ .001) after 6 years. No graft failure or rupture occurred. Graft patency was 100%. CONCLUSIONS: After a mean implantation of 6 years, the ePTFE/Gore, polyester/Braun, and polyester/Vascutek tube grafts presented with significant differences. The ePTFE grafts showed a stronger resistance against dilatation than the two types of polyester grafts. Owing to similar perioperative and postoperative courses, no advantage could be identified in any group concerning the overall outcome. Vascular implants for OSR of AAA made of ePTFE and polyester are safe, even after a long implantation time. Therefore, the choice of the suitable graft does not depend on its postimplantation dilative characteristics. The outcome is not likely to be connected with dilatation of the implanted graft, because a causal connection between graft dilatation and death cannot be made. The study does not offer a basis for the preference of one of the three graft types. Nevertheless, continuous ultrasound examinations should be performed after implantation of an aortic tube graft to identify possible problems arising from changes in the graft and the residual vascular branches over time.

Prospective randomized trial of operative vs interventional treatment for renal artery ostial occlusive disease (RAOOD).

INTRODUCTION AND OBJECTIVES: Patients with either renovascular hypertension (RVH) and/or renal insufficiency (RI) due to renal artery ostial occlusive disease (RAOOD) can successfully undergo an open surgical reconstruction procedure (OSRP), but since the publication of Blum et al(1) percutaneous balloon stent angioplasty (PTRA + stent) leaving a small part of the stent within the aorta has become very popular. However, balloon dilatation and stenting does not remove the atherosclerotic plaque, which is often heavily calcified but leads to disruption of the plaque causing myointimal hyperplasia and recurrent stenosis. Therefore, a comparison of the two treatment modalities concerning complications and durability in a prospective randomized design was felt to bring more insight to the discussion. METHODS: From 1998 to 2004, we performed OSRP in 330 patients with RVH and/or RI for various locations of RAOOD. During this time period, 50 patients (female 18, male 32, mean age 64.4 years) with RAOOD of at least 70% stenosis (DSA and duplex criteria) in one or both renal arteries, who did not require other aorto/mesenteric/iliac reconstructive procedures agreed and were randomized to either OSRP (n = 25 patients, 49 arteries) or PTRA + stent (n = 25 patients, 28 arteries). Two patients crossed over to surgical treatment. Patients were followed on a regular basis for 4 years and longer. Endpoints were re-occurrence of RAOOD and impairment of either kidney function or RVH. RESULTS: We approached 77 arteries. There was no early mortality in either group, but directly procedure-related morbidity was 13% in the interventional group and 4% in the surgical group. Four-year follow-up mortality was 18% in the interventional group and 25% in the surgical group. Both groups showed significant improvement of RVH (P < .001 in each group) as well as improvement or stabilization in patients with insufficient renal function. Freedom from recurrent RAOOD (>70%) was achieved in 90.1% of the surgical group and 79.9% of the interventional group. CONCLUSION: Both treatment modalities showed good early results concerning RVH, kidney function, and renal perfusion. Despite a higher number of bilateral renal artery reconstructions in patients undergoing OSRP, which was probably due to the preferred technique of transaortic endarterectomy eliminating the plaque originating in the aorta and usually extending into both renal arteries, mortality was not higher and procedure-related morbidity was even lower compared to PTRA + stent. These findings and also longer durability of OSRP imply that surgical reconstruction remains the gold standard for patients with RAOOD before PTRA + stent may be considered.

Duplex ultrasound and renin ratio predict treatment failure after revascularization for renal artery stenosis.

BACKGROUND: The aim of this study was to find predictors to identify patients with hypertension who will not improve after removal of renal artery stenosis (RAS). METHODS: Prospective study of patients with unilateral stenosis (>60% diameter reduction) and hypertension in 24-h measurements despite antihypertensive drugs, who underwent revascularization (surgery/angioplasty). Examinations were performed before treatment and after 3 and 6 months after exclusion of restenosis. Studies included 24-h blood pressure, creatinine clearance, 99Tc MAG3 scintigraphy, and measurements of renal vein plasma renin activity (PRA). Intrarenal resistance indices (RI) were determined with duplex ultrasound before and 30 min after administration of intravenous enalaprilat. Improvement of hypertension was defined by a score consisting of 24-h mean arterial pressure and the number of antihypertensive drugs. RESULTS: From December 2000 to December 2003, 50 patients completed the study. Improvement of hypertension was observed in 18 patients (36%). Comparison between responders (n = 18) and nonresponders (n = 32) revealed significant differences only for RI and PRA measurements. The largest area under the curve in receiver-operating characteristic (ROC) analysis for prediction of no improvement of hypertension was found for RI (stenosis side), which was nearly identical for measurements before and after administration of angiotensin-converting enzyme (ACE) inhibitor. The highest sensitivities and specificities predicting which patients will not improve were found for RIs > or = 0.55. The highest univariate odds ratio (OR 44, confidence interval [CI] 4.8-404) was found for the parameters of RI > or = 0.55 and a renin ratio of <1:1.5. CONCLUSIONS: Resistance indices of the poststenotic kidney above 0.55 and a negative renin ratio can predict a poor outcome concerning arterial blood pressure response after restoration of renal blood flow for unilateral renal artery stenosis.

Lipoplex gene transfer of inducible nitric oxide synthase inhibits the reactive intimal hyperplasia after expanded polytetrafluoroethylene bypass grafting.

OBJECTIVE: Intimal hyperplasia (IH) is most commonly the cause of graft occlusion in infrainguinal bypass grafting for arterial occlusive disease. We investigated the influence of nitric oxide on the IH of the arterial vessel wall at the region of prosthetic bypass anastomoses. METHODS: Experiments were performed in 10 Foxhound dogs. We used a technique of inducible nitric oxide synthase (iNOS) overexpression by a non-virus-mediated, liposome-based iNOS gene transfer. The plasmid pSCMV-iNOS, which drives the expression of iNOS under control of the cytomegalovirus promoter, was complexed with cationic liposomes (lipoplexes). Segments of both carotid arteries were pretreated by intramural injection of a lipoplex solution by using an infiltrator balloon catheter (Infiltrator Drug Delivery Balloon System). In each dog, iNOS was administered at one side, and a control vector (pSCMV2) was administered at the contralateral side. Carotid arteries were ligated, and bypass grafts (expanded polytetrafluoroethylene, 6-mm, ring enforced) were implanted on both sides. The proximal and distal anastomoses (end-to-side fashion; running nonabsorbable sutures) were placed in the pretreated regions. After 6 months, the prostheses were excised, and the intimal thicknesses of 50 cross sections (orcein staining) of each anastomosis were measured planimetrically. RESULTS: The average reduction of the neointima thickness of the iNOS side in proximal anastomoses at the prosthetic wall, suture region, and arterial wall was 43%, 52%, and 81%, respectively. In distal anastomoses, the average reduction was 40%, 47%, and 52%, respectively. All differences of neointima thickness between the iNOS and control sides were statistically significant (Wilcoxon test; P < or = .05). CONCLUSIONS: Inducible NOS expression is an efficient approach for inhibition of IH. In contrast to earlier studies, which investigated the efficacy of gene therapeutic NOS expression at 3 to 4 weeks after intervention, the novelty of our findings is that a single local lipoplex-mediated transfection of the vascular wall with iNOS-expressing plasmids leads to a reduction of IH in a prosthetic in vivo model even after 6 months. Because all components can be manufactured under Good Manufacturing Practice conditions (the quality-management system of the European pharmaceutical industry based on ISO 9000), this approach is also amenable to human therapy.

[Management of patients with renal artery stenosis. Reappraisal of operative treatment]. / Therapie der Nierenarterienstenosen. Pro Operation.

Arterial hypertension is most often the first symptom of renal artery stenosis (RAS). Appropriate screening methods for the diagnostic workup of hypertension are colour-coded duplex ultrasound and captopril scintigraphy. Angiography (intraarterial digital subtraction angiography) represents the diagnostic "gold standard", which is the prerequisite for the selection of the most suitable therapeutic method. Atherosclerosis is the most common disease in elderly patients presenting with RAS. In younger patients, fibromuscular dysplasia is more frequent. Five main types with different prognosis and therapeutic indications can be classified. Rare causes of RAS are dissection, renal artery aneurysm with combined stenosis, and especially in children and adolescents middle aortic syndrome with hypoplasia of the visceral arteries. Every patient with RAS of hemodynamic relevance in the presence of hypertension should be treated, whereas therapeutic risk and benefit must be weighed up individually. Aims are the improvement of hypertension and the maintenance of renal function. Surgical techniques, which are described subsequently, are indicated in all patients who need further simultaneous treatment of the abdominal vessels (abdominal aortic aneurysm, aortoiliac or visceral artery stenosis or aneurysm, respectively). In atherosclerotic ostial stenoses, angioplasty (PTA) and open surgery (normally transaortic endarterectomy) are concurrent methods. In our experience, the long-term results of surgical reconstruction seem to be superior. Both procedures are subject to an ongoing randomized study in our department. The outcome of surgical treatment for RAS is satisfying, the operative risk especially in isolated renal artery lesions is negligible.

Iliac artery stenosis proximal to a kidney transplant: clinical findings, duplex-sonographic criteria, treatment, and outcome.

BACKGROUND: Stenosis of the iliac segment proximal to the transplant renal artery (Prox-TRAS) is an uncommon cause of graft dysfunction and hypertension. We assessed the role of duplex sonography (DS) in regard to clinical and angiographic findings and followed the patients after percutaneous transluminal angioplasty (PTA), PTA stenting (PTAS), or surgery. METHODS: From January 1988 to August 2001, 97 of 1,064 kidney recipients underwent angiography for clinical or Doppler-sonographic suspicion of vascular problems. Kidney function, blood pressure, medication, and DS findings after renal transplantation (RTx) at the time of diagnosis of Prox-TRAS and after treatment were evaluated. RESULTS: Prox-TRAS was diagnosed in 16 patients (1.5%) (49.6+/-6.9 years). Four patients demonstrated early presentation of Prox-TRAS 1 to 7 days after RTx (group A), leading to acute renal failure but without hypertension. In all patients, DS revealed pulsus parvus et tardus, low pulsatility index (PI) (<1.0), and a pathologic flow profile in the iliac artery proximal and distal to the graft. After treatment (surgery in two patients, PTA in one patient, PTAS in one patient), all patients developed good renal function (creatinine 1.7+/-0.9 mg/dL). PI increased from 0.9+/-0.1 to 1.2+/-0.1 (P=0.04), and flow profile within the iliac artery distal to the graft normalized. Late presentation (3-209 months after RTx) of Prox-TRAS was observed in 12 patients (group B), causing an increase of creatinine in 11 patients (two patients receiving dialysis treatments), impairment of blood pressure (141+/-15 and 80.7+/-7 to 160+/-18 and 85+/-7 mm Hg, P=0.009), and an increase in antihypertensive drugs (2.1+/-1.1 and 4.3+/-1, P=0.003) in all patients. The PI was decreased when compared with values early after RTx (1.6+/-0.4 to 1.2+/-0.3, P=0.007), and flow profile in the iliac artery was pathologic. All patients except one were managed by surgery (n=6), PTA (n=1), or PTAS (n=4). Creatinine (2.7+/-1.4 to 1.8+/-0.4 mg/dL, P=0.02) and blood pressure (160+/-18/85+/-7 mm Hg to 138+/-7/82+/-9, P=0.018) improved. Antihypertensive drugs were reduced to 2.8+/-0.8 (P=0.01). PI increased from 1.2+/-0.3 to 1.9+/-0.5 (P=0.01). Flow profile within the iliac artery distal to the graft anastomosis normalized. Kidney function, blood pressure, and PI remained unchanged during follow-up (82+/-69.9 months) in both groups. CONCLUSIONS: Prox-TRAS is rare. Because clinical symptoms are similar to those of transplant renal artery stenosis, DS is a valuable tool for diagnosis and follow-up for this type of vascular lesion. Selective treatment with PTA, PTAS, or surgery improves kidney function and hypertension.

Surgical treatment of renal artery dissection in 25 patients: indications and results.

OBJECTIVE: Results of surgical revascularization in 25 patients with renal artery dissection (RAD) over 14 years, with mean follow-up of 55.3 months (range, 10-111 months), were analyzed. Indications for surgery were renovascular hypertension and preservation or improvement of kidney function. PATIENTS AND METHODS: Two patients (both 20 years of age) underwent emergency surgery after severe trauma; 23 patients (mean age, 41 years) underwent elective surgery in a chronic stage of disease. Preoperative, postoperative, and follow-up examinations included duplex ultrasound scanning, determination of serum creatinine and urea concentrations, and evaluation of blood pressure control. All long-term patients underwent digital subtraction angiography preoperatively and postoperatively. All histologic specimens of resected renal arteries were re-evaluated by two independent pathologists. RESULTS: Histologic re-evaluation confirmed the traumatic origin in 2 patients who underwent emergency surgery and 1 who underwent elective surgery. Renal artery dissection developed spontaneously, with no histologic signs of trauma or fibromuscular dysplasia, in 22 patients. In 17 revascularized kidneys (61%) a kidney infarction had already developed preoperatively, and the kidneys were diminished in size or function. Results of revascularization and improvement of hypertension depended on preoperative extent of renal infarction. Hypertension resolved or improved in 86% of patients without preoperative kidney damage, but in only 38% with preoperatively damaged kidneys. Kidney function was preserved in 23 of 28 revascularized kidneys (82%). During follow-up, late renal artery occlusion developed in 3 kidneys. CONCLUSIONS: Renal artery dissection can be effectively treated with surgical revascularization. Primary nephrectomy should be considered only in patients with a large ischemic kidney infarction, with significant deterioration of kidney function, to effectively cure or improve severe renovascular hypertension.

Reconstruction for renal artery aneurysm: operative techniques and long-term results.

BACKGROUND: Ninety-four patients (37 male, 57 female; mean age, 51.0 years) underwent reconstruction for renal artery aneurysm (RAA) between 1980 and 2001. RAAs were present in 52 patients in the right kidney, in 29 patients in the left kidney, and in 13 patients in both kidneys. Eighty-three aneurysms were located in the mainstem, 49 in a branch artery, and four in an accessory artery. Additional ipsilateral renal artery stenoses (RAS) occurred in 26 patients, bilateral RAS in 18, and contralateral RAS in six. The causes of RAA were fibromuscular dysplasia (n = 48), atherosclerosis (n = 28), dissection (n = 7), aortic coarctation (n = 5), arteritis (n = 3), giant cell arteritis (n = 1), Marfan's syndrome (n = 1), and trauma (n = 1). Seventy-five patients had hypertension, 14 were asymptomatic, and five had rupture. Indications for RAA repair concerned aneurysms with 1 cm or more diameter in combination with risk factors of hypertension, ipsilateral and contralateral stenosis, and childbearing age in women. Without risk factors, aneurysm size eligible for reconstruction was limited to 2 cm or more. METHODS: Methods applied for reconstruction in 107 kidneys and 136 aneurysms included aneurysm resection with tailoring (n = 37), saphenous vein graft interposition (n = 40), tailoring and saphenous vein graft interposition (n = 7), resection and reanastomosis (n = 14), saphenous vein graft interposition and resection and reanastomosis (n = 3), polytetrafluoroethylene bypass (n = 5), and homologous vein graft interposition (n = 1). Four reconstructions had to be performed ex situ because of multiple branch involvement in three patients and rupture in one. In all patients, the concerned kidney was protected with hypothermic flush perfusion with addition of heparin and prostaglandin E1. RESULTS: The overall morbidity rate was 17%, including one early graft occlusion, one partial thrombosis of the renal artery that necessitated fibrinolytic therapy, and a branch artery stenosis after tailoring managed with aortorenal bypass. The mortality in elective cases was null; one patient died of myocardial infarction 2 days after an emergency operation for ruptured RAA. The technical primary success rate was 96.8%; the secondary success rate was 98.9%. After a follow-up period from 1 to 143 months (mean, 46 months) in 83 patients (88%), 67 (81%) had patent renal arteries free of stenoses. Among six patients with RAS, four underwent successful reoperation, five had mainstem occlusions, three had segmental artery occlusions, and two underwent nephrectomy. Concerning the patients who underwent reoperation, percutaneous transluminal angioplasty was considered seriously but assessed as inappropriate because of long extension of stenosis or involvement of branch arteries. Hypertension was cured in 19 patients (25%) and improved in 17 (22%). CONCLUSION: Surgical reconstruction of RAA is a safe procedure that provides good long-term results, prevents aneurysm rupture, cures or improves hypertension in about half of the cases, and can be achieved with autogenous reconstruction in 96%.