Analysis of 855 Upper Extremity Fistulas Created Using a Standard Protocol: The Role of Graft Extension to Achieve Functional Status

The Fistula First Breakthrough Initiative (FFBI) has been one of the most important national programs to help achieve considerable improvements in the care of patients on chronic hemodialysis. FFBI has helped place guidelines to push practitioners to reduce the use of tunneled central venous catheters and to increase the rate of arteriovenous fistula use in patients requiring chronic hemodialysis access. However, despite current guidelines, no specific protocols exist for the creation and management of autogenous arteriovenous fistulas and outcomes at most centers are below national benchmarks. In this study, we examine the effectiveness of a standard protocol used at our institution for the creation of autogenous upper extremity fistulas for hemodialysis access in achieving early cannulation and early removal of tunneled dialysis catheters. Our review encompasses 855 consecutive autogenous fistulas created over a 10-year period. Our findings suggest that the use of a standard protocol for creation and management of autogenous fistulas can help increase the rate of functional accesses over national benchmarks. Additionally, extension/conversion of malfunctioning fistulas to grafts appears to be an excellent method to expedite removal of a tunneled dialysis catheter with concomitant preservation of a fistula

Clinical results of argon laser tissue fusion

Tissue fusion by laser energy is an intriguing arxi very promising new application for laser technology. In coniparison to using high laser energy to ablate tissue as in the aricplasty application, laser tissue fusion is possible in any soft tissue by deliverir appropriate lc levels of energy to the cppose tissue surfaces. This technology is particularly appealing for vascular applications in inakir sutureless blood vessel anastornosis and for securir the endpOints of erxarterect:amies ani dissection planes. Although there have been limitel evaluations of this technology the preliminary experimental ar1 clinical data is very promisir for continu development arid application

Potential of intraluminal ultrasound for angioplasty guidance

The manifestation of atherosclerotic lesions in arteries can vary from asymptomatic thickening in the vessel wall to complete occlusion. Experimental studies on non-human primates and on human subjects indicate that atherosclerotic lesions may progress without a reduction in luminal diameter because of dilatation of the arterial wall . Although angiography has been considered the "gold standard" for visualization of the arterial tree ar1 detection of luminal narrowing, it does not demonstrate arterial wall thickening or morphology. Moreover, the measurement of luminal diameter of the sane lesion can vary considerably depending on the plane of projection of the x-ray beam. This is attributed to the eccentric nature of the residual lumen in an atherosclerotic vessel . Extraluminal B-mode real time imaging has the feasibility of demonstrating arterial lumen and arterial wall thickness. However, it is still in some instances limited by inadequate resolution and image quality. Intraluminal ultrasound using a phased array or rotating transducer gives better definition of the vessel wall and luminal diameter as it is not limited by the tissue interposed between the vessel and the probe in transcutaneous devices. This paper demonstrates further experience with intravascular ultrasound as a diagnostic tool using B-mode real time imaging

In-vivo intravascular ultrasound in human ileo-femoral vessels

This study evaluates the ability of intravascular ultrasound (IUS) to image normal and mildly diseased human ileo-femoral vessels during angioplasty or vascular bypass procedures. Five Fr. and 8Fr. rotating A scan IUS catheters were used to obtain 43 images in 4 superficial femoral arteries, and 5 iliac arteries in 8 vascular surgery patients. Luminal cross sectional (LCS) areas measured by IUS were compared to LCS areas calculated by uniplanar angiography (ANGIO) at the same location in the vessel. The correlation between the areas (IUS vs ANGIO) for all images was significant (n = 43, r = 0.90, P<0.05). Mean LCS area calculated from ANGIO (33.7 +/- 21 mm ) was greater than LCS area measured by IUS (30.6 +/- 19.5 mm ) with n = 43; P = 0.02. In addition to providing accurate luminal determinations, IUS images displayed transmural morphology, the location of the atherosclerotic lesions and the thickness of the vessel wall. We conclude that IUS imaging provides accurate, novel information regarding human vessel wall anatomy and luminal dimensions. This technology may play a significant role in future diagnostic and interventional therapies

Continuous Piezoelectric Pulse-Sensor Monitoring of Peripheral Vascular Reconstructions

Postoperative assessment of vascular surgical reconstructive procedures is most commonly performed by means of Doppler flowmetry or manual pulse palpation. Because these techniques are intermittent and can be subjective, the authors have investigated the application of a piezoelectric pulse sensor in monitoring distal pulses continuously in patients undergoing limb revascularization. By placing a piezoelectric sensor on the skin overlying an artery, systolic displacement of the underlying vessel wall and tissue is converted into a graphically displayed real-time waveform. Hardcopies of the waveforms (n = 90) were obtained at hourly postoperative intervals from a total of 10 patients undergoing vascular surgery for occlusive disease. In all cases, continuous monitoring confirmed ongoing patency of the reconstructions, despite impalpable distal pulses in 60% of the patients. The amplitudes of the waveforms increased (mean = 18%, range = 6% to 33%) during the first eight postoperative hours. Because of the small size and sensitivity of the sensor, this technique was especially useful in patients with foot lesions requiring occlusive dressings, or where sequential stenoses prevented accurate assessment of postoperative circulation by manual palpation or Doppler examination. The authors conclude that continuous postoperative piezoelectric pulse monitoring allows accurate, continuous assessment of limb revascularization and alleviates the subjective, time-consuming observations by physicians and ancillary personnel

Intravascular Ultrasonography

Intravascular ultrasonography is developing rapidly as a method for defining the transmural anatomy of vascular structures, with diagnostic and therapeutic applications. The ultrasound technology not only has unique diagnostic capabilities by defining the distribution and character of lesions, but also provides accurate control information regarding efficacy of angioplasty methods. An exciting recent development is the three-dimensional reconstruction of two-dimensional images which permits global examination of luminal and transmural vessel morphology. This technology may enable improved guidance of intraluminal devices to enhance lesion removal without damaging adjacent normal wall structure and appropriate device selection by differentiating specific plaque characteristics

Surgical Management of Infected PTFE Hemodialysis Grafts: Analysis of a 15-Year Experience

The records of 52 consecutive patients who underwent surgical treatment for 57 episodes of hemodialysis graft infection (HGI) from 1977 to 1993 were reviewed to determine the mortality and morbidity associated with this complication and to clarify guidelines for its management. The study group consisted of 35 women and 17 men whose mean age was 57 years at initial graft placement. Thirty-three (58%) HGIs involved straight grafts in the upper arm, 12 (21%) straight forearm grafts, 11 (19%) loop forearm grafts, and 1 (2%) a loop groin fistula. All of these grafts were constructed with polytetrafluoroethylene (PTFE). All 57 cases of HGI showed at least local evidence and 41 (72%) caused systemic symptoms. Thirty-seven (65%) HGIs were associated with positive blood cultures. The predominant infecting organism was Staphylococcus, which was isolated alone or in combination with other organisms from 40 (70%) graft or wound sites. Seventy-eight percent (31/40) of the staphylococcal infections involved Staphylococcus aureus. The median time from graft implantation to diagnosis of HGI was 7 months (mean 16 months, range 0 to 77 months) and from diagnosis to surgical treatment, 4 days (mean 6 days, range 0 to 26 days). Initial surgical management consisted of complete excision of all prosthetic material in 43 (75%) cases and partial excision in 14. The 30-day mortality rate following the last operation for the treatment of HGI was 12% (6/52) and was not significantly increased by incomplete excision. Six (86%) of the early deaths were related to sepsis and each of these patients had positive blood cultures. None of the infected grafts could be salvaged without removal of at least part of the original graft. None of the 43 complete excisions was complicated by recurrent infection at the same time, whereas this complication did occur following six (43%) of the 14 procedures during which residual prosthetic material was left in place ( p = 0.00008, Fisher's exact test). Prosthetic HGI is a serious complication that is optimally treated by excision of all infected PTFE. Complete removal of synthetic material offers a significantly reduced risk of recurrent graft sepsis at the same site

Intraluminal Ultrasound Assessment of Vascular Stent Deployment

This study assessed the utility of intraluminal ultrasound imaging during deployment of a self-expanding vascular stent and quantitated changes in arterial morphology produced by the stent. Cross-sectional images of arterial lumens (n = 50) were obtained before stenting, in-vitro (n = 35) from formalin-preserved human superficial femoral arteries and in-vivo (n = 15) from canine iliac arteries containing laser-induced eccentric stenoses. Comparison of ultrasound-derived vessel dimensions (minimum and maximum diameter and cross-sectional area) with histological morphometric analysis of corresponding vessel sites showed good correlation by linear regression analysis (r = 0.930–0.987, p = 0.001–0.005). Following stent placement, 23 intraluminal ultrasound images were obtained from the stented vessel sites (in-vitro n = 15, in-vivo n = 8) and were compared to prestented cross-sectional areas. In the in-vitro vessels there was a small increase (p = 0.023) in area, but there was no change in the in-vivo arteries (p = 0.6). To assess the effect of stenting on luminal shape (ellipticity), minimum/ maximum diameter ratios were compared before and after stent deployment. There was an increase in this ratio in the in-vitro vessels (p = 0.001) but no change in the in-vivo arteries (p = 0.2). We conclude that intraluminal ultrasound produces clear and accurate images of the location, shape and degree of arterial pathology, ensuring good stent: vessel size matching and immediate quantitative assessment of the effects of arterial stent placement