Superior two-year results of externally unsupported polyester compared to supported grafts in above-knee bypass grafting: a multicenter randomised trial.

OBJECTIVES: The aim of this study was to compare externally supported thin wall knitted polyester (P-EXS) and externally unsupported thin wall knitted polyester (P-non-EXS) for above-knee (AK) femoro-popliteal bypass grafting. DESIGN: A prospective multicenter randomised clinical trial. MATERIAL AND METHODS: Between 1999 and 2008, 265 AK femoro-popliteal bypass grafts (6 mm in diameter) were performed, including 136 P-EXS and 129 P-non-EXS. The selection of patients was based on the presence of disabling claudication or critical ischaemia. Follow-up took place at 3, 6, 12, 18, and 24 months and included clinical examination and duplex ultrasonography. The main end points of this study were primary patency rates at one and two years. Secondary end points were mortality, and primary assisted and secondary patency rates. Cumulative patency rates were calculated with life-table analysis and log-rank testing. RESULTS: The 1-year primary, primary assisted and secondary patency rates were 65%, 70% and 84%, respectively, for P-EXS and 76% (p = 0.05), 82% (p = 0.03) and 88% (p = 0.35), respectively, for P-non-EXS. Two-year primary, primary assisted and secondary patency rates were 45%, 57% and 70%, respectively, for P-EXS and 62% (p = 0.003), 75% (p = 0.005) and 84% (p = 0.02), respectively, for P-non-EXS. The overall mortality rate after two years was 11.3%. CONCLUSION: In above-knee femoro-popliteal bypass grafting patency rates of externally supported knitted polyester grafts were inferior to their unsupported counterpart. ISRCTN: At the time this study started this number was not the standard.

Dacron or ePTFE for femoro-popliteal above-knee bypass grafting: short- and long-term results of a multicentre randomised trial.

OBJECTIVES: To compare expanded polytetrafluoroethylene (ePTFE) prosthesis and collagen-impregnated knitted polyester (Dacron) for above-knee (AK) femoro-popliteal bypass grafts. DESIGN: A prospective multicentre randomised clinical trial. PATIENTS AND METHODS: Between 1992 and 1996, 228 AK femoro-popliteal bypass grafts were randomly allocated to either an ePTFE (n=114) or a Dacron (n=114) vascular graft (6mm in diameter). Patients were eligible for inclusion if presenting with disabling claudication, rest pain or tissue loss. Follow-up was performed and included clinical examination and duplex ultrasonography at all scheduled intervals. All patients were treated with warfarin. The main end-point of this study was primary patency of the bypass graft at 2, 5 and 10 years after implantation. Secondary end-points were mortality, primary assisted patency and secondary patency. Cumulative patency rates were calculated with life-table analysis and with log-rank test. RESULTS: After 5 years, the primary, primary assisted and secondary patency rates were 36% (confidence interval (CI): 26-46%), 46% (CI: 36-56%) and 51% (CI: 41-61%) for ePTFE and 52% (CI: 42-62%) (p=0.04), 66% (CI: 56-76%) (p=0.01) and 70% (CI: 60-80%) (p=0.01) for Dacron, respectively. After ten years these rates were respectively 28% (CI:18-38%), 31% (CI:19-43%) and 35% (CI: 23-47%) for ePTFE and 28% (CI: 18-38%), 49% (CI: 37-61%) and 49% (CI: 37-61%) for Dacron. CONCLUSION: During prolonged follow-up (10 years), Dacron femoro-popliteal bypass grafts have superior patency compared to those of ePTFE grafts. Dacron is the graft material of choice if the saphenous vein is not available.

Randomized clinical trial of continuous sutures or non-penetrating clips for radiocephalic arteriovenous fistula.

BACKGROUND: Despite several modifications to the original design, patency rates of radiocephalic arteriovenous fistulas have changed little since the first report in 1966. The use of non-penetrating clips for vascular anastomosis on the outcome of such fistulas was studied. METHODS: Between January 2000 and August 2003, 107 primary radiocephalic fistulas were constructed in 98 patients. The vascular anastomoses were performed at random with either sutures (n = 56) or clips (n = 51). RESULTS: Although there were trends for better primary and primary assisted patency of clipped fistulas, the differences were not statistically significant. The 6-month primary patency rate was 61 per cent with sutures and 69 per cent with clips (P = 0.393). The mean(s.d.) primary patency was 315(306) and 285(285) days for clipped and sutured fistulas respectively. With regard to secondary patency, clipped fistulas were better (P = 0.009). The mean(s.d.) secondary patency was 435(376) and 344(316) days for clipped and sutured fistulas, respectively. There were no significant differences in flow characteristics, number of revisions or other morbidity. CONCLUSION: This randomized clinical trial provided further evidence that the use of vascular clips may improve the patency rate of radiocephalic arteriovenous fistulas for haemodialysis.

Outcome of abdominal aortic aneurysm repair in the era of endovascular treatment.

BACKGROUND: The effect on outcome of the introduction of endovascular techniques for the exclusion of abdominal aortic aneurysm (AAA) is largely unknown. The aim of the study was to contrast the early and mid-term outcome after open and endovascular AAA repair. METHODS: Consecutive patients who underwent transfemoral endovascular aneurysm repair (EVAR; n = 93) between April 1998 and January 2003, or conventional open aneurysm repair in the time intervals before (n = 113) and after (n = 82) the introduction of EVAR were studied. All data were collected prospectively. All patients underwent elective and primary repair. Patient survival was calculated by the Kaplan-Meier method and the possible predictive value of more than 25 perioperative variables on five outcome variables (length of intensive care unit stay, morbidity, and 30-day, 6-month and overall mortality) was assessed by multivariate analysis. RESULTS: There were no differences in risk profiles between the three groups. Selection for EVAR was based on anatomical grounds only. All five outcome variables were significantly better with EVAR than either former or recent open repair. The only significant predictors of failure were advanced age and the need to perform an additional procedure for former open repair; hypertension and the preoperative use of anticoagulants for recent open repair; and renal insufficiency and pulmonary insufficiency for EVAR. CONCLUSION: EVAR offered considerable benefits compared with conventional open repair at early and mid-term follow-up, which was not explained by selection of patients with a favourable risk profile. In the current era, in which patients are selected for open repair as a consequence of unfavourable anatomy, morbidity and mortality rates following conventional open treatment of AAA have increased at early and mid-term, but not at long-term, follow-up.

Ruptured abdominal aortic aneurysm: endovascular repair is feasible in 40% of patients.

INTRODUCTION: Open repair of ruptured abdominal aortic aneurysm (rAAA) still has a high mortality. Endovascular aortic repair (EVAR) may be the way to improve survival rates. However, it is not clear how many patients with rAAA will be suitable for acute EVAR. METHODS: Between October 2000 and April 2002 all patients with acute symptomatic or ruptured AAA were assessed for EVAR on an intention-to-treat basis with emergency computed tomographic angiography (CTA). Patient and logistic characteristics were analysed. We used two commercially available aorto uni-iliac devices with a maximum proximal diameter of 28 and 34 mm. RESULTS: Five out of 26 patients were excluded for CTA and EVAR because of severe and persistent hypotension (3 pts) or logistic reasons (2 pts, both eligible). Twelve patients were found not eligible for EVAR due to unsuitable infrarenal aortic neck length (3 pts), neck diameter (1 pt) or a combination of both (8 pts). The remaining six patients were treated with EVAR. After 6 months no graft failure or aneurysm related deaths were recorded in the EVAR group. CONCLUSION: A total of 28% of patients with symptomatic or ruptured AAA was treated with EVAR. A potential 42% of patients could have been suitable for EVAR, if the correct devices had been in stock and all patients had been properly assessed.

Effects of a venous cuff at the venous anastomosis of polytetrafluoroethylene grafts for hemodialysis vascular access.

INTRODUCTION AND METHODS: The most frequent complication of polytetrafluoroethylene (PTFE) arteriovenous grafts for hemodialysis is thrombotic occlusion due to stenosis caused by intimal hyperplasia. This complication is also known for peripheral bypass grafts. Because the use of a venous cuff at the distal anastomosis improves the patency of peripheral bypass grafts, we considered that it might also improve the patency of PTFE arteriovenous grafts. Therefore, a randomized multicenter trial was carried out to study the effect of a venous cuff at the venous anastomosis of PTFE arteriovenous grafts on the development of stenoses and the patency rates. RESULTS: Of the 120 included patients, 59 were randomized for a venous cuff. The incidence of thrombotic occlusion was lower in the cuff group (0.68 per patient-year) than in the no-cuff group (0. 88 per patient-year; P =.0007). However, the primary and secondary patency rates were comparable. The cuff group tended to have fewer stenoses at the venous and arterial anastomoses when examined with duplex scan. Graft failure was higher in patients with an initial anastomosing vein diameter smaller than 4 mm (7 of 18 [39%]) than in those with a vein diameter of 4 mm or larger (16 of 88 [18%]; P =. 052). Local edema, skin atrophy, and obesity yielded a higher risk on graft failure (23% vs 11%). CONCLUSION: A venous cuff at the venous anastomosis of PTFE arteriovenous grafts for hemodialysis reduced the incidence of thrombotic occlusions; stenosis at the venous anastomosis was reduced. However, this did not result in a better patency rate. Therefore, the venous cuff should not be used routinely. Initial vein diameter and local problems (edema, obesity, or skin atrophy) appear to be the most important risk factors for graft failure.

[The number of carotid artery operations in the Twente Medical Spectrum before and after the publication of relevant international research on the benefits of the relief of carotid stenosis]. / Het aantal carotisoperaties in het Medisch Spectrum Twente vóór en na de publicatie van belangrijk internationaal onderzoek naar het nut van A.-carotisdesobstructie.

OBJECTIVE: To determine the effect of adequate scientific research on the treatment of extracranial stenosis of the internal carotid artery. DESIGN: Retrospective and comparative. SETTING: Twenty Medical Spectrum, Enschede, the Netherlands. METHOD: A comparison was made of the relevant data from 2 years of carotid artery surgery before (1989-1990; period I) and after the publication of two randomized multicentre studies (1994-1995; period II). RESULTS: The number of patients treated surgically and the number of carotid artery desobstructions had increased during period II by 339% and 319%, respectively. In period I, 25% of the patients had an asymptomatic ipsilateral stenosis of the internal carotid artery; in period II, this had decreased to 11%. In period I, 65% of the patients had a stenosis in excess of 70% of the diameter of the vessel; in period II this was 85%. The combined mortality and permanent disabling morbidity after 30 days was 6% in period I and 3% in period II. CONCLUSION: After the publication of two high-quality studies in 1991, the number of carotid artery operations increased by over 300%. The indications for the surgical treatment of stenosis were stricter rather than less strict in period II. The increase of the number of carotid desobstructions can be explained by the fact that GPs' and neurologists' referral to the vascular surgeon has changed. This change in the referring pattern may be the consequences of use of 'evidence-based' medicine.

The renal and perirenal abscess: the role of ultrasound and computed tomography in its diagnosis, localization and treatment.

Perirenal abscesses are difficult to diagnose by clinical examination and traditional radiographic techniques. Four cases are reported in which ultrasound and computed tomography were very helpful in this respect. The role in the diagnosis and management of such abscesses with these two new technics of renal and perirenal imaging is discussed.

The obturator foramen bypass: an alternative procedure in iliofemoral artery revascularization.

The obturator foramen bypass has been described as an alternative procedure to solve complicated vascular problems in the groin. This extra-anatomic bypass has been used successfully in cases of infection, mycotic aneurysms, traumatic lesions, irradiation ulcers, and excessive scar tissue in the femoral triangle. With this technique, the vascular continuity can be restored immediately. Although data on the long-term results of this operative procedure are not yet available, out report and a review of the literature suggest that the obturator foramen bypass is a very useful technique for saving a patient's leg and in some cases his life.