Biomedical subjects

T Hagenaars

Publications and source records attributed to T Hagenaars.

12 recordsLinked to original sources

PubMed2003

Remote endarterectomy: first choice in surgical treatment of long segmental SFA occlusive disease?

OBJECTIVES: to report the long term results of remote superficial femoral artery endarterectomy (RSFAE) with the MollRing Cutter for the treatment of long segmental SFA occlusive disease. DESIGN: retrospective open study. PATIENTS AND METHODS: from March 1994 to August 2000 183 RSFAEs were performed in 164 selected patients (105 males, 120 procedures) with a median age of 63 years (43-84 years). Indications for operation were disabling intermittent claudication in 129 procedures (70%), rest pain in 20 procedures (11%), and limb salvage in 34 procedures (19%). Follow up consisted of clinical evaluation, ankle-brachial index measurements and duplex scanning. RESULTS: the mean follow-up time was 29.3 months. The mean length of the endarterectomised SFAs was 31 cm (range, 17-45cm). The five year cumulative primary patency rate by means of life table analysis was 37.8+/-6.67% (SE). Percutaneous transluminal balloon angioplasty and surgical re-intervention were performed in twenty-nine and four patients respectively resulting in a primary assisted patency rate of 47.9+/-6.27%. Limb salvage was achieved in 30 of the 34 patients. Females had a statistically significant lower primary patency rate, i.e., 26 vs 45% (p -value=0.01). CONCLUSIONS: the long term results of remote SFA endarterectomy show that it is a safe, effective and durable, minimally invasive procedure. It also leaves open all other options for conventional bypass procedures. The five-year primary patency rate is at least similar to prosthetic above-knee bypass surgery.

Adult↗

PubMed2002

Gamma radiation induces positive vascular remodeling after balloon angioplasty: a prospective, randomized intravascular ultrasound scan study.

BACKGROUND: Endovascular brachytherapy (EBT) has been shown to prevent restenosis after percutaneous transluminal coronary angioplasty (PTA) in both animal and clinical studies. However, as yet, the effect of EBT on peripheral arteries is unknown. OBJECTIVE: This intravascular ultrasound scan (IVUS) study evaluates the effect of EBT on the extent of plaque growth and vascular remodeling after PTA of the femoropopliteal artery. METHODS: Twenty-four patients with obstructive disease of the femoropopliteal artery underwent standard PTA. Patients were randomized to receive no additional therapy or additional EBT (192-Iridium) after PTA. IVUS investigation was performed after PTA and at 6-month follow-up. A comparison was made between patients without EBT (n = 16) and with EBT (n = 8) in the change in lumen, vessel, and plaque area and plaque dissections seen with IVUS at 6-month follow-up. RESULTS: At follow-up, IVUS revealed a significant difference in lumen area change between patients without and with EBT (-9% and +23%, respectively; P =.03). This difference was the result of a significant difference in vessel area change (+2% and +19%, respectively; P =.05). In both groups of patients, a similar increase in plaque area (+12% and +16%, respectively; P =.80) was encountered. Plaque dissections encountered immediately after PTA were absent at follow-up in patients without EBT, whereas in four of the eight patients with EBT, a persistent dissection was encountered. CONCLUSION: This randomized IVUS study showed that gamma-radiation after PTA has a positive effect on lumen dimensions at 6-month follow-up by inducing positive vascular remodeling (ie, vascular dilatation); gamma-radiation seemed not to affect plaque growth. In addition, gamma-radiation has an effect on the healing process of dissections after PTA.

Adult↗

PubMed2002

Management of aortic graft infection.

BACKGROUND: The optimal method of operative treatment of prosthetic aortic graft infection (PAGI) has been the subject of debate; incidence rates of PAGI are low. Diagnosis of PAGI can be difficult. The aim of this retrospective study is to evaluate our results in treating PAGI in order to try and optimize the treatment of this grave problem. METHODS: Thirty-eight patients (median age 68.5 years) were treated for PAGI between 1991 and 2000. Management of PAGI was performed with total graft excision and simultaneous extra-anatomic bypass (n=18), total graft excision and in situ repair with a Rifampicin-soaked gelatin-impregnated prosthetic aortic graft (n=8), or a partial excision with in situ repair (n=11). In 1 patient, only local irrigation was performed. The median follow-up was 45 months. RESULTS: Clinical presentation of PAGI (median interval 3 years) was: discomfort/pain (n=14), gastro-intestinal bleeding (n=11), persisting fever (n=8), or a non-healing wound (n=5). The primary patency rate in patients with extra-anatomic bypass was 67% at 6 months follow-up. In patients with other surgical reconstructions no graft occlusion was encountered. Overall amputation rate was 5%. Recurrent infection of the graft was 15%. The overall early mortality rate in this study was 21%. CONCLUSIONS: The diagnosis of PAGI is difficult and should be based on a combination of clinical symptoms, laboratory findings and imaging techniques. There are several treatment options that should be tailored to the extent of infection and the patients' physical condition. In a selected group of patients partial excision of the infected graft only can be justified.

Aged↗

PubMed2001

Rationale and design for the SARIS trial; effect of statin on atherosclerosis and vascular remodeling assessed with intravascular sonography. Effect of Statin on Atherosclerosis and vascular Remodeling assessed with Intravascular Sonography.

PURPOSE: The SARIS study (effect of Statin on Atherosclerosis and vascular Remodeling assessed with Intravascular Sonography) is a prospective randomized multicenter trial designed to assess both morphological and functional cardiovascular effects of atorvastatin. METHODS: Participating centers will include 50 patients with normal to mildly elevated cholesterol levels eligible for balloon angioplasty and/or stent placement of the common iliac artery. Patients will be randomized to 1-year treatment with either low-dose (10 mg) or high-dose (80 mg) atorvastatin. The morphological effects of atorvastatin will be studied using intravascular ultrasound (IVUS); the effect of atorvastatin on both plaque volume and vascular remodeling seen at 1-year follow-up will be investigated. The functional cardiovascular effects of atorvastatin will be studied using dobutamine stress echocardiography (DSE); the effect of atorvastatin on myocardial coronary flow reserve at 6-months and 1-year follow-up will be investigated. The aims of the present study are noteworthy in respect that (1) IVUS is the only available technique to sensitively measure the effect of atorvastatin on both intimal hyperplasia and vascular remodeling, and (2) DSE is a non-invasive test to objectively quantify the effect of atorvastatin on the functionality of the coronary artery.

Anticholesteremic Agents↗

PubMed2001

Intravascular ultrasound evidence for stabilization of compensatory enlargement of the femoropopliteal segment after endograft placement.

PURPOSE: To document whether the vasodilatory response seen at the anastomotic segment 6 months after placement of a balloon-expandable endograft in the femoropopliteal segment progresses between 6 and 24 months. METHODS: Twelve patients (9 men; median age 65 years, range 47-75) treated with an investigational polytetrafluoroethylene (PTFE) endograft for obstructive disease of the femoropopliteal segment were studied with intravascular ultrasound (IVUS) immediately after placement and at 6 months (first follow-up period) and 24 months (second follow-up period). Matched IVUS cross sections derived from the endograft and the anastomotic segment were analyzed for changes in lumen (LA), vessel (VA), and plaque areas (PLA). RESULTS: Five patients had complete IVUS surveillance at both the first (mean 8 months, range 7-9) and second (mean 25 months, range 23-26) follow-up periods; 1 patient was lost to follow-up during the second interval, and another 6 were excluded owing to graft occlusion (n = 4) or no IVUS surveillance available (n = 2) during the second follow-up period. Matched IVUS cross sections derived from the endograft showed no significant change in LA during both follow-up periods (-8% and +1%, respectively). There was no evidence for intimal hyperplasia or endograft recoil. During both follow-up periods, IVUS cross sections derived from the anastomotic segment revealed significant increases in LA (+37% and +8%, respectively) and VA (+26% and +6%, respectively) (both p < 0.05). The change in PLA during both follow-up periods was not significant (+13% and +3%, respectively). CONCLUSIONS: The PTFE endograft seems to inhibit both intimal hyperplasia and constrictive remodeling. The short-term (6-month) vascular dilatory response seen at the anastomotic segment tends to stabilize at 2 years. Therefore, this endovascular anastomosis acts as an "ideal" end-to-end anastomosis.

Aged↗

PubMed2000

Effect of simvastatin on restenosis after percutaneous transluminal angioplasty of femoropopliteal arterial obstruction.

This retrospective observational intravascular ultrasound study evaluated whether simvastatin therapy limits lumen area reduction 1-year after percutaneous transluminal angioplasty (PTA) by reducing reactive plaque growth, reducing reactive vasoconstriction, or both. This study showed that plaque growth is a general response 1 year after PTA regardless of the use of simvastatin; simvastatin has the potential to induce positive vascular remodeling, thereby reducing the occurrence of restenosis.

Adult↗

PubMed2000

Progression of atherosclerosis at one-year follow-up seen with volumetric intravascular ultrasound in femoropopliteal arteries.

Volume measurements derived from intravascular ultrasound (IVUS) images assessed with an automated contour analysis system are accurate and reproducible. However, it is unknown to what extent plaque volume may change at follow-up. Therefore, the purpose of this longitudinal study is to examine whether IVUS is a sensitive means to identify progression of atherosclerosis and its derived primary end point plaque volume at 1-year follow-up. Patients (n = 11) undergoing percutaneous transluminal angioplasty (PTA) of the femoropopliteal artery were studied with IVUS immediately after PTA in the same session and at 1-year follow-up. Matched, well-identified vascular segments (3 to 4 cm in length), not subjected to PTA, imaged at baseline and after 1-year follow-up, were used for calculation of the longitudinal change in lumen, vessel and plaque volume, and mean plaque thickness. The median length of the selected vascular segments was 4 cm. At follow-up (12+/-2 months) a nonsignificant increase in lumen volume (2.3+/-11%), vessel volume (2.0+/-7.0%), and plaque volume (3.0+/-5.1%) was seen; the mean plaque thickness increase was 2.2+/-5.6%. In conclusion, progression of atherosclerosis implies changes in plaque and vessel volume, resulting in lumen volume change. This observation has important implications for future clinical trials aimed at monitoring the effect of pharmacologic agents on the progression and/or regression of atherosclerosis.

Adult↗

PubMed2000

Reproducibility of calcified lesion quantification: a longitudinal intravascular ultrasound study.

In view of a prospective intravascular ultrasound (IVUS) study, the reproducibility of the extent of the calcified lesion in IVUS images derived from separate pull-back maneuvers was assessed. Patients (n = 34) were imaged with IVUS before and after percutaneous transluminal angioplasty (PTA) and at 1-y follow-up. In the presence of a calcified lesion, the largest arc and the length of the matched calcified lesions was assessed. Interobserver differences in arc measurements were low (< or = 0.7%), with low coefficients of variation (< or = 5.8%). Similarly, interexamination differences in arc and length measurements were small (< or = 1.1%), with low coefficients of variation (< or = 3.2%). At follow-up, a nonsignificant increase in both the arc (1.9%) and length (1.7%) of the calcified lesion was observed. This study showed that measurements of the calcified lesion are highly reproducible; changes seen at 1-y follow-up were not significant. We conclude that IVUS may be used to monitor the effect of medical intervention on the extent of the calcified lesion in a longitudinal study.

Adult↗

PubMed2000

Reproducibility of volumetric quantification in intravascular ultrasound images.

The reproducibility of volume measurements in intravascular ultrasound (IVUS) images derived from separate pull-back manoeuvres remains to be elucidated. Patients (n = 23) were imaged with IVUS prior to (first series) and following percutaneous transluminal angioplasty (PTA) (second series). In 15 patients, one matched vascular segment (3-4 cm in length), not subjected to PTA, was used for analysis of lumen, vessel and plaque volume using an automated contour analysis system. Volume measurements assessed by two independent observers and in the two separate series were compared. Interobserver differences in volume measurements were small (< or =0.4%), with low coefficients of variation (< or =1.7%) and high correlation coefficients (r = 1.00). Differences in volume measurements obtained in the two separate series were small (< or =2.6%), with low coefficients of variation (< or = 8.6%) and high correlation coefficients (r = 0.97-0.99). In conclusion, volume measurements derived from IVUS images are highly reproducible. Therefore, IVUS may be used to monitor the progression/regression of atherosclerotic plaque volume in a longitudinal study.

Aged↗

PubMed2000

Early experience with intravascular ultrasound in evaluating the effect of statins on femoropopliteal arterial disease: hypothesis-generating observations in humans.

The purpose of this study was to compare the vascular response seen with intravascular ultrasound (IVUS) at 1-year follow-up between statin-treated and non-statin-treated patients. Patients (n = 10) undergoing percutaneous transluminal angioplasty (PTA) of the femoropopliteal artery were studied with IVUS immediately after PTA and at 1-year follow-up. In nondilated matched vascular segments, the change in lumen, vessel, and plaque volume was assessed. In balloon-dilated matched vascular segments, the change in lumen, vessel, and plaque area was assessed. A comparison was made between statintreated (n = 5) and non-statin-treated patients (n = 5) in lumen, vessel, and plaque changes. At follow-up, both statin-treated and non-statin-treated patients showed a similar increase in plaque volume at the nondilated segment (+4% and +2%, respectively). In statin-treated patients the plaque volume increase was compensated by an increase in vessel volume (+2%), resulting in an increase in lumen volume (+1%). In non-statin-treated patients, on the other hand, the increase in plaque volume was associated with a decrease in vessel volume (-2%), resulting in a decrease in lumen volume (-4%). At the balloon-dilated segment a similar trend in changes of lumen, vessel, and plaque was encountered. Differences between both groups of patients were not statistically significant. Despite the nonsignificant nature of the observation, this small retrospective IVUS study may generate the hypothesis that statin therapy may contribute to superior long-term lumen dimensions by inducing positive vascular remodeling both in nondilated and balloon-dilated vascular segments.

Adult↗

PubMed2000

Vascular response in the femoropopliteal segment after implantation of an ePTFE balloon-expandable endovascular graft: an intravascular ultrasound study.

PURPOSE: To use intravascular ultrasound (IVUS) to document changes in vascular dimensions after placement of a balloon-expandable endograft. METHODS: Thirteen patients (9 men; mean age 62 years, range 47-75) treated with an investigational polytetrafluoroethylene endograft for obstructive disease of the femoropopliteal segment were studied with IVUS immediately after endograft implantation and at follow-up. Corresponding IVUS cross sections were analyzed for changes in lumen, vessel, and plaque areas seen inside the endograft, in the anastomotic segment, and in the remote arterial segment. RESULTS: A mean 6-month (range 1.5-9) follow-up was completed in 12 patients. Matched IVUS cross sections derived from within the endograft (n = 12) and at the endograft edges (n = 23) showed no change in lumen area (LA) in 17, reduction in 11, and dilatation in 7. Median changes within the endograft (+3%) were not significant (p = 0.28) and no neointima was found. Cross sections obtained at the anastomotic segment revealed a significant increase in LA (85%, p < 0.001), which was associated with a significant increase in both vessel area (VA) (42%, p < 0.001) and plaque area (PLA) (15%, p = 0.003) area. In the remote arterial segment, the change in LA was minimal (6%, p = 0.07), as were changes in the VA (9%, p = 0.04) and PLA (10%, p = 0.07). CONCLUSIONS: Following endograft placement, luminal changes within the endograft, at the endograft edges, and at the remote arterial segments were minimal. Intimal hyperplasia was not observed in the endograft. The distinct LA increase at the anastomotic segments was determined by the extent of VA and PLA change.

Aged↗

PubMed2000

Peripheral vascular brachytherapy: an introduction.

The response of cells to ionising radiation has been extensively studied for the past 30 years. When radiation is absorbed in biological material, it can directly ionise a critical site (direct effect) or interact with other molecules to produce reactive free radicals, which can subsequently damage critical biological molecules (indirect effect). DNA is considered the critical target damaged by ionising radiation by both direct and indirect processes. Since radiotherapy had proven to be effective in the treatment of non-malignant proliferative processes, it was assumed that this adjunctive treatment would also inhibit vascular restenosis. The major difference between external and intravascular radiation is dose distribution. Intravascular delivery results in extremely high doses to the lumen with a fall-off in dose as a function of distance from the source; whereas, external beam would deliver a uniform dose over the entire volume of tissue treated. Unlike in the coronary circulation most of the peripheral vessels treated are greater than 3 mm in diameter; in fact many are 7 to 10 mm in diameter. Since beta radiation is related to lower penetration properties and more heterogeneous distribution of radiation in comparison to gamma radiation, it is therefore necessary to use a gamma radiation source because it would be difficult to irradiate the sub-intimal tissue with a beta source centred in a large vessel. Radiation can and does have the potential to destroy blood vessels. The challenge in vascular brachytherapy is to treat blood vessels to a point where restenosis is inhibited; yet the vessel is not irreparably damaged.

Animals↗