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.

Immediate transcatheter embolization of Swan-Ganz catheter-induced pulmonary artery pseudoaneurysm.

Digital subtraction angiography is an indispensable complement to cut film studies for the detection of pulmonary artery injury. Immediate transcatheter embolization of catheter-induced pulmonary artery pseudoaneurysm is a safe, minimally invasive, fast, and cost-effective alternative to surgical treatment.

Hyperkalemia secondary to concurrent pharmacotherapy in a patient receiving home parenteral nutrition.

We report a case of probable combined octreotide- and heparin-induced hyperkalemia. The patient had been receiving home parenteral nutrition, enoxaparin, and octreotide for 10 months. She required very little potassium in her PN solution to maintain serum potassium concentrations in the normal range. The patient reportedly did not receive other medications or have clinical conditions that, to our knowledge, cause hyperkalemia. She maintained normal renal function throughout the hospitalization and did not appear to have any significant acid-base disorders. Practitioners should be aware of the potential for octreotide and heparin to cause hyperkalemia. Regular monitoring of serum potassium concentrations should be done for patients receiving octreotide and heparin to avoid hyperkalemia.

The CT findings in pseudomembranous colitis.

The authors present their experience with the CT appearance of pseudomembranous colitis in 6 patients. In addition to the previously reported thickened colon wall, pericolonic inflammation was also noted in 5 of the patients.

Impaired sensorimotor gating in Fmr1 knock out and Fragile X premutation model mice.

Fragile X syndrome (FXS) is a common inherited cause of intellectual disability that results from a CGG repeat expansion in the FMR1 gene. Large repeat expansions trigger both transcriptional and translational suppression of Fragile X protein (FMRP) production. Fragile X-associated Tremor/Ataxia Syndrome (FXTAS) is an allelic neurodegenerative disease caused by smaller "pre-mutation" CGG repeat expansions that enhance FMR1 transcription but lead to translational inefficiency and reduced FMRP expression in animal models. Sensorimotor gating as measured by pre-pulse inhibition (PPI) is altered in both FXS patients and Fmr1 knock out (KO) mice. Similarly, FXTAS patients have demonstrated PPI deficits. Recent work suggests there may be overlapping synaptic defects between Fmr1 KO and CGG knock-in premutation mouse models (CGG KI). We therefore sought to interrogate PPI in CGG KI mice. Using a quiet PPI protocol more akin to human testing conditions, we find that Fmr1 KO animals have significantly impaired PPI. Using this same protocol, we find CGG KI mice demonstrate an age-dependent impairment in PPI compared to wild type (WT) controls. This study describes a novel phenotype in CGG KI mice that can be used in future therapeutic development targeting premutation associated symptoms.

Older adults and their families in a community mental health center: strategies for intervention.

Clinicians at a geriatric evaluation and treatment clinic include the patient's family in all stages of assessment and intervention so that the family can ultimately assume much of the responsibility for care. The family's strengths and weaknesses and its potential as a caretaker are assessed through a questionnaire and interviews. The major intervention techniques include explaining the patient's impairment and capabilities to the family, coordinating needed community resources, encouraging respite activities, allowing relatives to work through their own feelings, and taking responsibility for decision-making when necessary. A case history illustrates the assessment and intervention techniques.

Retinal dialysis.

Whether idiopathic or the result of ocular trauma, retinal dialysis is one of the least understood causes of retinal detachment. Dialyses are a common cause of retinal detachment and are the leading cause of traumatic retinal detachment in children and young adults. A dialysis is a disinsertion of the retina found at the ora serrata, generally involving less than 3 clock hours. Because a patient may be asymptomatic, a dialysis may be missed during ophthalmoscopic examination of the ocular fundus unless scleral indentation is used. Anatomical reattachment of detachments from retinal dialysis is highly successful for dialyses of both traumatic and idiopathic origin, with good visual results obtained postoperatively.

Radiologic evaluation of continent urinary reservoirs.

A variety of methods are currently used for urinary diversion after cystectomy in adults. Radiologists are generally familiar with ileal and colonic conduits but are less familiar with the recently popularized continent urinary reservoirs. We describe and illustrate the surgical technique, normal anatomy, and normal radiographic appearance of a variety of urinary reservoirs, including the Kock pouch, Camey procedure, and various ileocecal reservoirs. Complications of various reservoirs are also discussed and illustrated.

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.

Acute repair of aorta-innominate vein fistulas.

Penetrating wounds of the central vasculature are highly lethal. Ten cases of aorta-left innominate vein fistulas have been reported in the past, but most have presented late after injury. We report three successfully managed cases that had a short interval between injury and repair, and where we used cardiopulmonary bypass with total circulatory arrest. Preoperative arteriography facilitated planning the operative approach. The ready availability of complete radiologic and surgical resources at a trauma center were responsible for the successful outcome of these highly lethal central vascular injuries.

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.