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Biomedical subjects

S Saddekni

Publications and source records attributed to S Saddekni.

At least 19 recordsLinked to original sources

Predictors of arteriovenous graft patency after radiologic intervention in hemodialysis patients.

Arteriovenous grafts in hemodialysis patients are prone to recurrent stenosis and thrombosis, requiring frequent radiologic and surgical interventions to optimize their long-term patency. Little is known about the factors that determine graft outcome after a radiologic intervention. The present study examined the clinical and radiologic predictors of intervention-free graft survival after elective angioplasty or thrombectomy. A prospective computerized database was used to determine the outcomes subsequent to all graft angioplasties (n = 330) and thrombectomies (n = 326) performed at the University of Alabama at Birmingham between April 1, 1996, and June 30, 1999. Primary graft survival rates after angioplasty and thrombectomy were 86% versus 43% at 1 month, 71% versus 30% at 3 months, 51% versus 19% at 6 months, and 28% versus 8% at 12 months, respectively. The median intervention-free graft survival time was substantially longer after angioplasty than thrombectomy (6.7 versus 0.6 months; P < 0.001). The superior outcome of angioplasty over thrombectomy was observed even for the subset of procedures with no residual stenosis (median survival, 6.9 versus 2.5 months; P < 0.001). The median graft survival was inversely related to the magnitude of residual stenosis for both elective angioplasty and thrombectomy. Median intervention-free graft survival after angioplasty was inversely related to the postangioplasty intragraft to systemic systolic pressure ratio (7.6, 6.9, and 5.6 months for ratios <0.4, 0.4 to 0.6, and >0.6, respectively; P < 0.001). Intervention-free graft survival after angioplasty or thrombectomy was not affected by graft location (forearm versus upper arm), number of stenotic sites, or presence of diabetes. In conclusion, graft survival is substantially longer after elective angioplasty than thrombectomy, even when the radiologic appearance after the procedure suggests complete resolution of the stenotic lesion. Moreover, the risk for requiring a subsequent graft intervention can be predicted from two simple radiologic measurements: grade of stenosis and intragraft to systemic systolic blood pressure ratio. These parameters may help determine the frequency of monitoring for recurrent stenosis in a given graft.

Aged↗

Bacteremia associated with tunneled dialysis catheters: comparison of two treatment strategies.

BACKGROUND: Tunneled dialysis catheters are often used for temporary vascular access in hemodialysis patients, but are complicated by frequent systemic infections. The treatment of bacteremia associated with infected tunneled catheters requires both antibiotic therapy and catheter replacement. We compared the outcomes of two treatment strategies for catheter-associated bacteremia: exchange of the existing catheter with a new one over a guidewire versus catheter removal with delayed replacement. METHODS: We retrospectively analyzed the outcomes of all cases of tunneled dialysis catheter-associated bacteremia during a two-year period. The infection-free survival time of the subsequent catheter was evaluated in two groups of patients: group A (31 catheters), exchange of the existing infected catheter with a new catheter over a guidewire, and group B (38 catheters), removal of the infected catheter followed by delayed catheter replacement 3 to 10 days later. Patients in both groups received three weeks of systemic antibiotic therapy. Cox proportional hazard models were used to evaluate the factors predictive of infection-free survival time of the replacement catheter. RESULTS: On univariate proportional hazard regression analysis, the infection-free survival time of the replacement catheter was similar for groups A and B (P = 0.72), whereas the hazard of infection was significantly greater for patients with hypoalbuminemia (serum albumin < 3.5 g/dL), as compared with patients with a normal serum albumin (hazard ratio 2.81, 95% CI, 1. 21, 6.53, P = 0.016). The infection-free survival time was not affected by patient age, sex, diabetic status, or type of organism (gram-positive coccus vs. gram-negative rod). CONCLUSIONS: The infection-free survival time associated with the subsequent catheter is similar for the two treatment strategies. However, exchanging the catheter for a new one over a guidewire minimizes the number of separate procedures required by the patient. Hypoalbuminemia is the major risk factor for recurrent bacteremia in the replacement catheter.

Adult↗

A multidisciplinary approach to hemodialysis access: prospective evaluation.

Dialysis access procedures and complications represent a major cause of morbidity, hospitalization and cost for chronic dialysis patients. To improve outcomes and reduce the cost of hemodialysis access procedures we developed a multidisciplinary approach, involving nephrologists, access surgeons, and radiologists. A full-time dialysis access coordinator scheduled all access procedures with the surgeons and radiologists, and tracked outcomes. A computerized database was developed for prospective documentation of procedures and complications. Confidential, detailed analyses and recommendations for improvements were provided periodically to the surgeons and radiologists. The major changes arising from the multidisciplinary approach were as follows: (1) The approach to clotted grafts evolved from an inpatient surgical procedure to an outpatient radiologic procedure. The immediate technical success rate of graft declots increased from 48% to 69%. (2) Elective placement of arteriovenous (A-V) grafts evolved from a three-day inpatient hospitalization to a largely outpatient procedure. The proportion of A-V grafts placed as same day surgery or outpatient surgery increased from 16% to 81%. (3) Surgical complications of new A-V graft surgery decreased from 25% to 11%. (4) Aggressive detection and correction of graft stenosis decreased the incidence of graft thrombosis by 60%, from 0.70 to 0.28 events per patient-year. (5) The proportion of native A-V fistula construction in new dialysis patients increased from 33% to 69%. In conclusion, an integrated multidisciplinary approach markedly reduced surgical complications of access surgery and decreased access failures. These improvements occurred despite a marked decrease in hospitalization for access procedures, with a substantial cost saving.

Aged↗

Hemodialysis access graft stenosis: US detection.

PURPOSE: To prospectively evaluate the sensitivity of ultrasonography (US) in diagnosing stenosis of hemodialysis access grafts and their drainage veins in patients clinically suspected of having graft dysfunction. MATERIALS AND METHODS: Thirty-eight patients in whom dysfunction of their hemodialysis access grafts was suspected underwent both Doppler US and angiography. Gray-scale and color US were combined with spectral analysis of the graft, anastomoses, and venous outflow. Flow velocity at anastomoses and suspected stenotic areas was measured. The volume of flow in the graft was also measured. The prospective US criterion for diagnosis of stenosis was a focal twofold or higher elevation of peak systolic velocity (PSV) compared with the PSV immediately upstream. A blinded angiographic evaluation of the graft and drainage veins followed US. Angiographic diagnosis of stenosis required at least 50% narrowing in luminal diameter. US and angiographic results were then compared. RESULTS: Angiography allowed diagnosis of 43 stenoses in 34 patients. US depicted 92% (37 of 40) of these stenoses, with a 94% positive predictive value for any individual patient. Focal 2- to 2.9-times PSV elevation was associated with 75% or greater stenosis. Graft flow volume and resistive index change did not correlate with stenosis. CONCLUSION: US reliably depicts stenoses of hemodialysis access grafts and drainage veins in a clinically selected population when PSV criteria are used.

Adult↗

Closure of an iatrogenic femoral artery pseudoaneurysm by transcutaneous coil embolization.

Pseudo-aneurysm following diagnostic or interventional procedures is a well-recognized complication. Ultrasound guided compression repair is routinely used to close an uncomplicated pseudo-aneurysm. We describe a patient with a femoral artery pseudo-aneurysm following iliac angioplasty and stenting in which ultrasound guided compression repair failed. Pseudoaneurysm was successfully closed by transcutaneous coil embolization technique.

Aged↗

Translumbar inferior vena cava catheter for long-term hemodialysis.

Vascular access failure is a major cause of morbidity and even mortality in patients on chronic hemodialysis. The failure of conventional vascular access and thrombosis of the superior vena cava in a patient with ESRD was successfully treated by the percutaneous insertion of a hemodialysis catheter directly into the inferior vena cava. The translumbar access to the inferior vena cava has been used successfully in bone marrow transplant recipients and may also be used as a last choice for long-term hemodialysis when conventional access is difficult.

Arteriosclerosis↗

Percutaneous laser disc decompression. A new therapeutic modality.

The authors present a new advance in the treatment of herniated disc disease using percutaneous Nd:YAG laser to vaporize a small portion of nucleus pulposus, thereby decompressing the disc. In vitro and in vivo animal data are presented. Three hundred seventy-seven magnetic resonance imaging or computed tomography scan-documented, herniated, nonsequestered lumbar intervertebral discs with corresponding clinical findings in 333 patients were so treated in an outpatient setting. The longest follow-up was 62 months, with a mean of 26 months. According to the Macnab criteria, there was a good to fair response in 261 patients (78.4%), and a poor response in 72 (21.6%); 166 patients experienced relief of pain during the procedure. One-third of repeat magnetic resonance imaging scans at 4-6 months postlaser treatment showed modest to moderate decrease of disc herniation.

Adult↗

Gastric and hepatic infarction following embolization of the left gastric artery: case report.

The authors report an initially successful left gastric artery embolization performed because of massive upper gastrointestinal bleeding; the procedure was complicated by focal gastric and hepatic infarctions. These complications occurred in the absence of underlying factors known to predispose to ischemia. Low-grade gastric bleeding persisting after seemingly successful embolization of the left gastric artery may indicate ischemic gastritis and is an indication for endoscopy. In addition, the presence of a left hepatic artery completely replaced to the left gastric artery should alert one to the potential for hepatic necrosis.

Aged↗

Percutaneous transluminal angioplasty of infrapopliteal vessels: preliminary results and technical considerations.

Infrapopliteal balloon angioplasty was performed in 11 patients facing reconstructive surgery for limb salvage. Twelve separate sessions of angioplasty were performed, during which 15 of 16 diseased tibial runoff vessels were successfully dilated. Three complications occurred during percutaneous transluminal angioplasty (PTA). One was related to the concomitant use of a thrombolytic agent to open a femoropopliteal bypass graft and not related to the angioplasty itself. No limbs were lost as a result of complications. The procedure was a technical success in nine of 12 cases (75%) and an initial clinical success in eight of the nine that were technically successful (89%). Follow-up ranged from 1 to 22 months. Six of the nine cases (67%) remained clinically successful during this period. Preliminary results suggest that infrapopliteal PTA is a safe and effective alternative to surgical reconstruction in selected patients.

Aged↗

Aortic dissection: a statistical analysis of the usefulness of plain chest radiographic findings.

Findings on plain chest radiographs of patients with aortic dissection are variable and often overlap those of patients without dissection. To determine which findings were most useful in predicting aortic dissection, plain chest radiographs from 36 patients with aortographically proven aortic dissection and 36 patients from a control population were randomized and analyzed independently by five radiologists for the presence of various radiographic features associated with this condition. A widened aortic knob, widened descending aorta, and widened mediastinum showed the greatest interobserver agreement (p less than .001) although the overall interobserver agreement was poor. The final conclusion of the radiologists was a better predictor of dissection than any of the individual radiographic features alone. Widening of the mediastinum (p less than .001) and widening of the aortic knob (p less than .012) were the only two radiographic features of significance in predicting dissection. In a stepwise multiple logistic regression model, the radiologists achieved an overall accuracy of 85%, a sensitivity of 81%, and a specificity of 89%. Although this illustrates the usefulness of plain chest radiographs in diagnosing aortic dissection, poor interobserver agreement dictates that further definitive investigation be undertaken.

Adolescent↗

Percutaneous transluminal renal angioplasty in the treatment of renovascular hypertension in children.

We report five young patients who underwent percutaneous transluminal renal angioplasty (PTRA) for the treatment of hypertension related to renal artery stenosis. Four had fibromuscular disease and one had probable Takajasu's arteritis; two had solitary kidneys. Following PTRA, a prompt decrease in blood pressure was observed in all patients. Further, four of five patients long after PTRA remained normotensive, and in all patients plasma renin levels declined. These results indicate that PTRA can be a safe and effective alternative to surgery in the treatment of renovascular hypertension in childhood.

Adult↗

Antegrade catheterization of the superficial femoral artery.

A simple method of selective catheterization of the superficial femoral artery (SFA) following antegrade puncture of the common femoral artery is described. The method entails using a Cope-type dilator introducer, which directs the guide wire from its side hole into the SFA while the tip is secured in the deep femoral artery.

Angioplasty, Balloon↗

Intimal fibromuscular dysplasia and Takayasu arteritis: delayed response to percutaneous transluminal renal angioplasty.

Percutaneous transluminal renal angioplasty has been shown to be an effective technique to dilate renal artery lesions, particularly those due to fibromuscular dysplasia. However, four of 70 patients in this study experienced atypical responses to angioplasty. Their lesions initially resisted dilation and had incomplete dilatation immediately after angioplasty. Long-term follow-up (1 week to 2 years) angiograms, however, demonstrated fully dilated arteries. In cases of focal nonatherosclerotic lesions from intimal or adventitial fibroplasia, initial incomplete dilatation may be satisfactory in the long term whereas repeated inflations may result in undesirable complications.

Adolescent↗

The oblique coronal view in sonography of the retroperitoneum.

The abdominal aorta and inferior vena cava can be seen easily from the right flank on a longitudinal coronal-oblique sonogram, using the liver as an acoustic window. With this view, tortuosity of the abdominal aorta can be shown, just as it appears on frontal aortography in 70% of cases, and similar to aortography in 27% of cases. The proximal renal and common iliac arteries can be demonstrated in 73% and 82% of cases, respectively, when aneurysms are absent, and in 45% and 82% of patients when aortic aneurysms are present. Enlarged posterior abdominal lymph nodes may be detected with accuracy, sensitivity, and specificity of 90% when compared to computed tomography (CT). Prominent gonadal vessels and anomalous or duplicated venae cavae can be displayed longitudinally, just as they might appear on venography. The coronal oblique view from the right flank, and occasionally from the left flank, can be a valuable addition to the standard views obtained during abdominal sonography. It is also a valuable supplement to CT in the differentiation of paraaortic vessels from enlarged lymph nodes.

Abdomen↗