PEPE II--a multicenter study with an end-point heparin-bonded expanded polytetrafluoroethylene vascular graft for above and below knee bypass surgery: determinants of patency.

AIM: The Propaten European Product Evaluation (PEPE II) study was a product evaluation intended to characterize the performance of the GORE PROPATEN vascular graft in above-knee (AK) and below-knee bypass (BK) surgery. METHODS: This prospective multicenter trial enrolled 142 patients with peripheral arterial disease. In 87 patients AK and in 52 patients BK bypasses (including 15 femorocrural) were implanted (67.6% males, 32.4% females). RESULTS: The one-year overall primary and secondary patency rates were 80% and 84.7%, respectively. Overall limb salvage rate at 12-months was 96.2%. The primary patency rate for AK bypasses was 82.7%, for BK femoro-popliteal bypasses 74.2% and for BK tibial-peroneal bypasses 79.4%. Secondary patency rates were 87.3%, 78.8% and 85.1%, respectively. Primary patency rates decreased depending on the number of patent run-off vessels (three 84.3%, two 80.8%, one 73.3%). Subgroup analysis showed that female patients had a significantly higher primary patency rate for BK bypasses (95.5% vs. 67.8%, P=0.037 ) compared to male patients. Subgroup analysis comparing patients younger and older than 70 years did not show a statistically significant difference in patency rates. Twenty-one patients underwent 42 reinterventions after bypass surgery. CONCLUSIONS: Present data show that the end-point heparin-bonded polytetrafluoroethylene graft yields patency rates comparable to those obtained with other graft material in above-knee locations. The encouraging results for BK bypasses suggests that this graft is an excellent option for small diameter vascular reconstructions when autologous vein is unavailable.

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.

Cervical mediastinoscopy in The Netherlands: past or present? A retrospective analysis of 218 procedures.

BACKGROUND: Cervical mediastinoscopy (CM) has been considered the gold standard for the evaluation of mediastinal lymph nodes in the staging of non-small cell lung cancer (NSCLC) for many years. Recent publications on the value of PET scanning might reduce the use of CM in the near future. The aim of this study was to analyse the data of our CM procedures for their reliability and contribution in the assessment of mediastinal lymph nodes. METHODS: In the period 1995-1999, 219 patients underwent CM. Data were available on 218 procedures and were analysed retrospectively. CM was performed in 162 men and 56 women with a median age of 56 years [range 29 to 80 years]. RESULTS: Median hospitalisation time was three days. There was no mortality and morbidity was 6%. In 96% of procedures representative lymphoid tissue was obtained. In 24%, biopsies contained malignancy. CONCLUSIONS: CM is a relatively safe procedure with a high diagnostic yield. As long as PET scanning remains available at a limited level, CM remains the gold standard in The Netherlands for patients with apparently operable NSCLC.

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.

[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.

Pharmacokinetics of low-molecular-weight heparin and unfractionated heparin during elective aortobifemoral bypass grafting.

Perioperative monitoring has demonstrated that administration of heparin on an empirical basis is associated with a wide variation in patient response and elimination rate. This problem may be overcome by intervention on the basis of perioperative monitoring or by using forms of heparin with different pharmacokinetic properties. When compared with unfractionated heparin, low-molecular-weight heparin has a higher bioavailability after subcutaneous administration, a linear clearance mechanism with a prolonged half-life, and is at least as effective in preventing postoperative vein thrombosis. Theoretically these characteristics of low-molecular-weight heparin could lead to more predictable levels of heparin activity. In this study we compared the pharmacokinetics of low-molecular-weight heparin and unfractionated heparin after an intravenous injection in patients undergoing aortic graft surgery. Heparin activity was measured before heparin administration and at 5, 20, 35, 50, 65, 80, 95, and 110 minutes after administration. The anti-Xa activity in the low-molecular-weight heparin group showed less variation and was more sustained when compared to the unfractionated heparin group. Fibrin degradation products were moderately correlated with the anti-factor Xa levels of the low-molecular-weight heparin group, but no correlation was found in the unfractionated heparin group. The anti-factor Xa activity of low-molecular-weight heparin was, in contrast to that of unfractionated heparin, not completely reversible by protamine administration. The blood loss was comparable in both groups. In contrast to what was expected, the pharmacokinetic profiles of low-molecular-weight heparin and unfractionated heparin showed a similarity after intravenous injection in patients undergoing aortobifemoral bypass grafting. Factors that could have influenced the pharmacokinetic behavior of heparin are discussed.

[A patient with a wide aorta and 2 wide kidney pelves: retroperitoneal fibrosis]. / Een patiënt met een wijde aorta en twee wijde nierbekkens: retroperitoneale fibrose.

The case is discussed of a patient with renal insufficiency due to severe stenosis of both ureters brought about by a periaortic inflammatory process. Such periaortitis is seen in severe atherosclerosis; the condition allegedly occurs in 5 to 23% of all patients with an abdominal aortic aneurysm. The literature on this form of retroperitoneal fibrosis is reviewed.

Diagnosis and management of graft-enteric fistulae.

During a 7-year period 20 patients underwent operation for a graft-enteric fistula after implantation of an intra-abdominal vascular prosthesis months or years before. Eighteen patients had gastrointestinal blood loss as their first symptom; 12 were in shock on admission. Fourteen patients had a fistula between the proximal anastomosis and the duodenum. Graft excision followed by axillobifemoral bypass was performed in 10 patients and four patients underwent local repair. A fistula between the distal anastomosis and the bowel was found in the remaining six patients and a local repair was carried out. Proximal graft-enteric fistula carries a particularly high postoperative mortality rate of more than 50 per cent.