A new stretch polytetrafluoroethylene (PTFE) aortic graft became available for clinical use in early 1991. We prospectively evaluated our first 107 stretch aortic PTFE grafts by means of serial CT imaging and compared them with a cohort of concurrently placed Dacron grafts. Stretch PTFE requires no preclotting and is claimed to resist long-term dilation and conform well to anastomoses. Consecutive patients undergoing placement of stretch PTFE grafts were seen at least yearly. Within the first 2 years after implantation, contrast-enhanced CT scans of the abdomen and pelvis were obtained. Caliper measurements were made of the native arteries and the body and any limbs of the aortic grafts. Graft elongation was assessed by noting distortions from the normally circular or minimally ovoid configuration of the grafts on transverse CT images. Indications for grafting were elective repair of abdominal aortic aneurysm in 60 patients, aortoiliac occlusive disease in 31, both aneurysm and occlusive disease in eight, and ruptured abdominal aortic aneurysm in eight. The overall operative mortality rate was 6.5%. There were two early postoperative graft limb thromboses resulting from hypercoagulable states, and there was one graft infection. Mean follow-up was 14.1 months (range 1 to 34 months). CT scans were obtained from 61 patients with stretch PTFE grafts and 10 with concomitantly placed Dacron grafts. Ten patients had two or more postoperative CT scans. Primary stretch PTFE patency was 98% and secondary patency, 100%. There was significantly less dilation of both the graft body and limbs in the stretch PTFE group (body mean 16.5%, range 6.3% to 28.1%; limb mean 19.3%, range 10% to 43%) compared to the Dacron group (body mean 33%, range 22% to 78%; limb mean 62%, range 12.5% to 88.9%) (p < 0.01, unpaired t test).(ABSTRACT TRUNCATED AT 250 WORDS)

Download full-text PDF

Source
http://dx.doi.org/10.1007/BF02143857DOI Listing

Publication Analysis

Top Keywords

stretch ptfe
20
ptfe grafts
12
stretch
8
stretch polytetrafluoroethylene
8
aortic graft
8
dacron grafts
8
body limbs
8
abdominal aortic
8
aortic aneurysm
8
occlusive disease
8

Similar Publications

PTFE Stent Membrane Based on the Electrospinning Technique and Its Potential for Replacing ePTFE.

ACS Appl Bio Mater

December 2024

National Engineering Laboratory for Modern Silk, College of Textile and Clothing Engineering, Soochow University, No. 199 Ren'ai Road, Industrial Park, Suzhou 215123, PR China.

Expanded poly(tetrafluoroethylene) (ePTFE), obtained by the paste extrusion-stretching method, is a commonly used stent membrane material for the treatment of arterial stenosis or aneurysm in clinical practice. However, the structure of ePTFE is nonfibrous, which is not friendly to cells, and the equipment consumes a lot of energy and often requires the use of flammable and toxic lubricants. In this study, electrospinning was used to prepare PTFE vascular stent membranes, following plasma treatment, dopamine, and heparin grafting to obtain an anticoagulant surface.

View Article and Find Full Text PDF

Despite offering several potential benefits over standard prosthetic aortic valve replacement, the use of the pulmonary autograft has been limited to date due to concerns over the risk of pulmonary autograft expansion and the need for reintervention. Several techniques using materials with biomimetic potential have been developed to reduce this complication. The incidence, risk factors, and pathophysiology of pulmonary autograft dilatation are discussed in this article.

View Article and Find Full Text PDF

Flexible zeolite membranes are promising for scalable and adaptable separation of critical gases such as helium; however, the synthesis of such membranes remains a significant challenge. In this study, we report the successful fabrication of crack-free ZSM-5 zeolite membranes on polytetrafluoroethylene (PTFE) supports using a seeded growth method. PTFE-supported membranes exhibit unprecedented helium permeance of over 6.

View Article and Find Full Text PDF

Molecular symmetry change of perfluoro-n-alkanes in 'Phase I' monitored by infrared spectroscopy.

Anal Sci

September 2024

Laboratory of Chemistry for Functionalized Surfaces, Division of Environmental Chemistry, Institute for Chemical Research, Kyoto University, Gokasho, Uji, Kyoto, 611-0011, Japan.

Article Synopsis
  • The phase diagram of polytetrafluoroethylene (PTFE) consists of four distinct regions, with Phases II and IV displaying twisted R chains at specific twisting rates, while Phase III features a planar trans-zigzag structure.
  • Phase I remains an unresolved area, as it does not correlate to a single structure and is characterized by a complex helical arrangement that untwists as temperature rises above 30 ºC.
  • To better understand the transition and disorder in Phase I, vibrational spectroscopy techniques, particularly infrared spectroscopy, are proposed as an effective alternative for analyzing molecular symmetry changes linked to the twisting rate of PTFE chains.
View Article and Find Full Text PDF

-Extremely-Low Frequencies (ELF, 30∼300Hz) transmitting antennas in wireless communications are often limited by antenna size and complex impedance matching networks. In this paper, we propose an ultra-small Artificial Electret Type Mechanical Antenna (AETMA), which is composed of a single charge electret and a driving structure, with high radiation efficiency and small size. In order to improve the electric dipole moment of the mechanical antenna, we employ a pin-plate corona polarization technique and a unidirectional stretching treatment to obtain a porous thin-film electret that can stably store a large amount of charge.

View Article and Find Full Text PDF

Want AI Summaries of new PubMed Abstracts delivered to your In-box?

Enter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!