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Arif Asif

Publications and source records attributed to Arif Asif.

29 records · Page 2Linked to original sources
PubMedDate not supplied

Peritoneal dialysis access-related procedures by nephrologists.

Traditionally the placement of a peritoneal dialysis (PD) catheter in a patient with end-stage renal disease (ESRD) has been accomplished by a surgeon and using general anesthesia. This approach often introduces delays in starting PD, incurs additional costs in utilizing an operating room as well as anesthesia services, and introduces the mortality risk associated with general anesthesia. Recent data have emphasized that interventional nephrologists can safely and successfully perform PD access procedures. In this context, operating room facilities and staff and anesthesia services are not required and catheter insertion can be performed in a procedure room using local anesthesia, thereby reducing costs and completely bypassing the mortality risk associated with general anesthesia. When performed by a nephrologist, the catheter insertion can be accomplished swiftly and dialysis therapy initiated in a timely manner. Once begun, the success of PD hinges on reliable and long-term access to the peritoneal cavity. Prospective randomized and nonrandomized studies have shown that PD catheters peritoneoscopically placed by nephrologists have fewer complications (infection, exit site leak) and longer catheter survival rates than those inserted surgically. Although PD offers a variety of advantages, it remains an underutilized form of renal replacement therapy. To counteract PD underutilization, at least two separate centers have demonstrated a positive impact on the growth of the PD population when catheter insertion is performed by nephrologists. This article presents PD access-related procedures currently performed by interventional nephrologists. Furthermore, some of the complicating issues (bowel perforation, catheter migration, prior abdominal surgery) related to PD catheter insertion and management are also discussed.

Catheterization↗
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Hemodialysis vascular access: percutaneous interventions by nephrologists.

Traditionally hemodialysis vascular access-related procedures have been almost exclusively performed by surgeons and interventional radiologists. In recent years, nephrologists have taken the initiative of performing these procedures themselves. Because of their unique clinical perspective on dialysis access and better understanding of the intricacies of renal replacement therapy, nephrologists are ideally suited for this activity. This approach has minimized delays, decreased hospitalizations, and decreased the use of temporary catheters, thereby improving medical care, decreasing costs, and increasing patient convenience. Vascular access-related procedures commonly performed by nephrologists include percutaneous balloon angioplasty, thrombectomy, and tunneled hemodialysis catheter-related procedures. In addition, using vein obliteration and percutaneous balloon angioplasty techniques, nephrologists have recently documented successful salvage of arteriovenous fistulas that had failed to mature, whereas traditionally these fistulas have frequently been abandoned. While the performance of these procedures by nephrologists offers many advantages, appropriate training in order to develop the necessary procedural skills is critical. Recent data have emphasized that a nephrologist can be successfully trained to become a competent interventionalist. In addition to documenting excellent outcome data, multiple reports have demonstrated the safety and success of interventional nephrology. This review focuses on hemodialysis access-related procedures performed by nephrologists and calls for a proactive approach in optimizing this aspect of patient care.

Angioplasty, Balloon↗
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Creation of secondary arteriovenous fistulas: maximizing fistulas in prevalent hemodialysis patients.

National Kidney Foundation Dialysis Outcomes Quality Initiative (NKF-DOQI) guideline 29 suggests that a patient should be evaluated for a secondary arteriovenous fistula (AVF) following each episode of dialysis access failure. Regretfully, it does not appear that this approach is used, even though recent data have emphasized that veins suitable for the creation of a secondary AVF can be identified in dialysis patients who are receiving dialysis via a synthetic arteriovenous graft (AVG) or other type of potentially dysfunctional vascular access. In this study nine patients (five with an AVG and four with an AVF) with vascular access dysfunction undergoing percutaneous interventions were evaluated for secondary AVF creation. All were found to have suitable vascular anatomy and had the AVF created. The secondary fistula was successful in all nine patients with a mean follow-up of 4.8 +/- 1.4 months in post-AVG cases and 5.6 +/- 1.7 months in the post-AVF patients. In addition, it was possible to continue uninterrupted dialysis without the use of a tunneled dialysis catheter in three of the patients with AVGs. This experience demonstrates the validity and success of this approach to the management of dialysis access dysfunction. In the ongoing effort to optimize vascular health status, we suggest that during percutaneous interventions, patients should routinely have identification of vessels suitable for creation of a secondary AVF.

Adult↗
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Does catheter insertion by nephrologists improve peritoneal dialysis utilization? A multicenter analysis.

In contrast to hemodialysis (HD), peritoneal dialysis (PD) remains an underutilized form of renal replacement therapy in the United States. Although a variety of factors have been deemed responsible, timely insertion of a PD catheter may also be a contributory factor. We conducted a multicenter analysis to examine whether the establishment of a program for PD catheter insertion by nephrologists has a positive impact on the growth in the number of patients using PD. Data for catheter insertion performed by nephrologists were collected from three centers. Any change in the prevalent PD population at each respective center was compared to the number of PD patients during the period having the traditional surgical approach. Nephrologists at the three centers used the peritoneoscopic technique and performed catheter insertion under local anesthesia. In center 1, the PD population remained stable at between 38 and 45 patients (approximately 16% of the total end-stage renal disease [ESRD] population) from 1993 to 2001. Nephrologists initiated a program for PD catheter insertion in 2001. The number of PD patients has increased to 101 (32% of the ESRD population). In center 2, the PD population remained stable at between 70 and 78 patients (approximately 17%) between 1988 and 1990. Catheter insertion by interventional nephrologists began in 1991. The number of PD patients has increased to 125 (22%). In center 3, the PD population remained at 20-30 patients (approximately 18%) between 1988 and 1991. Catheter placement by nephrologists was initiated in 1991. The number of PD patients increased to 97 (27%). Catheter insertion by interventional nephrologists was suspended in 2001. The number of PD patients has gradually declined to 25 (6%). This study suggests that catheter insertion by the nephrologist can have a positive impact on the utilization of PD.

Catheters, Indwelling↗
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Venous mapping using venography and the risk of radiocontrast-induced nephropathy.

Venous mapping using venography has been considered to be the gold standard for identifying veins suitable for arteriovenous fistula (AVF) creation. By utilizing a radiocontrast medium, however, venography introduces the risk of radiocontrast-induced nephropathy. The risk of this complication in the chronic kidney disease (CKD) population has not been previously studied. Twenty-five consecutive patients (CKD stage 4 and 5) undergoing venography were enrolled in this study. Patients were advised not to fast for the procedure and were encouraged to take oral fluids. Radiocontrast-induced nephropathy was defined as a 20% decrease in the estimated glomerular filtration rate (GFR) from the baseline value at 48 hours after contrast administration. Weekly telephone calls were made for a total of 4 weeks to assess the need for dialysis. Venography was performed by interventional nephrology using 10-20 cc of low osmolarity contrast medium. Data were collected prospectively. Median age was 48.9 +/- 7.8 years and 52% of the patients had diabetes. Complete sets of pre- and postprocedure GFRs were available in 21 patients. At 48 hours, there were no differences between the pre- and postprocedure GFRs. At the third week, one patient developed flu-like symptoms with severe gastroenteritis and was hospitalized for volume depletion. This patient initiated dialysis during the hospital stay. We conclude that at 48 hours, our cohort did not develop radiocontrast-induced nephropathy. During the 4-week phone call follow-up, only one patient needed dialysis. Large-scale studies with a longer follow-up using GFR estimation are needed to confirm these preliminary findings.

Acute Kidney Injury↗
PubMedDate not supplied

Salvage of problematic peritoneal dialysis catheters.

Peritoneal dialysis (PD) is a markedly underutilized modality for permanent renal replacement therapy in the United States owing to a low rate of patient referral and high rate of patient dropout or transfer to hemodialysis. One cause for patient loss from PD is problematic PD catheters that often are removed rather than being subjected to simple surgical salvage procedures. We report three patients with problematic catheters and our approach to their management. The first patient developed erosion of the skin overlying the portion of the catheter between the deep and superficial cuffs after 6 months of PD. The second patient developed extrusion of the superficial cuff after 4 years of PD. The third patient demonstrated a localized abscess at the incision site for catheter insertion after 3 years of PD. Other than a mild superficial exit site infection and localized abscess in the second and third patient, respectively, there were no associated infections of the catheter tunnel and cuff or of the peritoneal cavity as determined by either clinical examination, ultrasound evidence of fluid collection, or cultures and white blood cell counts. All three cases were managed successfully by interventional nephrology on an outpatient basis and under local anesthesia without either catheter removal or placement of a new PD catheter. It was possible to continue uninterrupted PD in the first and third patients, while the second patient had temporary hemodialysis to allow for complete healing of the surgical wound. We conclude that in selected cases simple interventions can salvage problematic PD catheters and maintain patients on PD.

Aged↗
PubMedDate not supplied

Optimal timing for secondary arteriovenous fistula creation: devastating effects of delaying conversion.

A chronic hemodialysis patient was referred to interventional nephrology for evaluation of arteriovenous access dysfunction. The patient had been receiving hemodialysis using a left forearm brachiobasilic loop graft for the past 3 years. Physical examination revealed a hyperpulsatile graft. Angiography documented a critical stenosis at the vein-graft anastomosis and a well-developed basilic vein from the elbow to the axillary region. Central veins were patent all the way to the right atrium. All attempts to navigate the wire across the stenosis failed. The patient was educated and counseled regarding the possibility of surgical creation of a secondary arteriovenous fistula (AVF). The images obtained were shared and discussed with the surgeon. A plan to create a secondary AVF using the basilic vein in the arm was made. A few months later the patient was referred to interventional nephrology, this time for thrombectomy of the same left arm loop graft. Thrombectomy could not be performed and a right internal jugular tunneled catheter was inserted. The patient again was referred to the surgeon for AVF creation. Six weeks later the patient was seen in the interventional laboratory for removal of the right internal jugular tunneled catheter. It was noted that instead of a fistula, the patient had received a right forearm brachiocephalic loop graft. Devastating consequences, such as the lost opportunity to create a fistula, insertion of a tunneled dialysis catheter, arteriovenous graft placement, exhaustion of available sites for fistula creation, and exposure to increased morbidity and mortality associated with grafts and catheters, can result if the opportunity to create a secondary AVF is not availed in a timely manner. This concept must be understood by every member of the vascular access team.

Aged↗
PubMedDate not supplied

Overutilization of central venous catheters in incident hemodialysis patients: reasons and potential resolution strategies.

Even after adjusting for comorbidities, the outcomes in hemodialysis (HD) patients using a central venous catheter (CVC) as dialysis access are worse than in those with a permanent vascular access. In spite of this, nationwide data suggest that only about 25% of incident HD patients initiate dialysis with an arteriovenous fistula. We conducted a retrospective study to identify reasons and resolution strategies for CVC use in patients who initiated HD at an academic medical center with a well-established chronic kidney disease (CKD) clinic and a dedicated vascular surgeon. Estimated glomerular filtration rate (eGFR) loss over time to record progression of patients to HD was also examined. The charts of 170 consecutive patients were reviewed. Ninety-two percent were found to initiate HD using a CVC. Three factors explained 93% of all CVC in our cohort: absence of adequate predialysis care (45%), acute illness with failure to recover from an episode of acute renal failure (31%), and patient's failure to adhere to scheduled clinic or surgical appointments (17%). In addition, analyses of eGFR suggest that the velocity of GFR loss rather than a defined degree of renal function might be a better trigger for vascular access referral. We conclude that early referral, a close follow up of CKD patients who initiate dialysis due to acute illness, and patient education may have a positive impact to counteract overutilization of CVCs for dialysis. The rate in eGFR decline might also be used to calculate the referral time adequate for fistula creation.

Acute Kidney Injury↗
PubMedDate not supplied

Utility of static pressure ratio recording during angioplasty of arteriovenous graft stenosis.

Intra-access static pressure ratio (SPR) (intra-access pressure/mean arterial pressure) can be measured during angioplasty (PTA) to assess the functional importance of an arteriovenous graft (AVG) stenosis. We used SPR in 70 patients with AVGs who underwent 98 angioplasty procedures. SPR was measured during angioplasty by placing a catheter tip at mid-access. Inflow stenosis (IF) = stenosis proximal to the tip of the catheter. Outflow stenosis (OF) = stenosis distal to the tip of the catheter up to the superior vena cava-atrial junction. Post PTA, access flow (Qa) was assessed within 2 weeks. Complete data sets for both SPR and Qa were available in 83 procedures. Using a normal SPR ratio of 0.3-0.4 at mid-graft, three patterns of SPR were noted. In 63 of 83 (76%) cases SPR was elevated prior to PTA (0.71 +/- 0.13 SD). PTA reduced SPR toward normal range (0.44 +/- 0.12) in 53 cases (84%). In the remaining 10 (16%), SPR decreased to a low value (0.22 +/- 0.03) and normalized (0.40 +/- .0.11) only after PTA of a coexisting inflow stenosis. In 12 of 83 (14%) procedures, the initial SPR was low (0.18 +/- 0.04) and increased toward normal (0.3 +/- 0.08) following IF stenosis PTA in seven (58%) cases. For the remaining five (42%) cases SPR increased to a high value (0.70 +/- 0.21) and decreased toward normal range (0.33 +/- 0.07) only after OF stenosis angioplasty. In 8 of 83 (10%) procedures, initial SPR was normal (0.33 +/- 0.02). Angiography revealed coexisting IF and OF stenoses. SPR remained within the normal range after PTA of these lesions (0.33 +/- 0.02). Qa increased significantly in 74 of 83 (89%) procedures (before = 572 +/- 201, after = 1109 +/- 368 ml/min; p < 0.001). SPR measurements can assist in hemodynamic assessment of an AVG during angioplasty procedure.

Aged↗
PubMedDate not supplied

Nephrology nurses in a new role: diagnostic and interventional nephrology.

Diagnostic and interventional nephrology is a growing subspecialty of nephrology. Increasingly, procedural care of nephrology patients is being managed by nephrologists trained in this area. As a result, new opportunities have been created for nephrology nurses as they assist these interventionists in the administration of care in diagnostic and interventional nephrology. This article describes the components of a diagnostic and interventional nephrology program, the initiation of such a program at a university center, and the role of nephrology nursing personnel in this rapidly developing area.

Academic Medical Centers↗