A Patient Centered Decision Making Dialysis Access Algorithm

Much controversy surrounds the establishment of proper planning, placement and management (the best practice pattern) of dialysis access. These include the dialysis type and modality selection, timing of access placement and who places the access. The lack of and the difficulty of performing randomized studies with multiple confounding factors, in an extremely heterogeneous and rapidly changing ESRD population demographics, only partly explains the dialysis access conundrum. Add to this the rapidly developing and competing technologies, the wide spectrum of the professional experience, bias and socio-economic forces to make the ESRD problems as multivariate and complex as life itself.

This overview describes a dialysis access algorithm approach to the patient needing renal replacement therapy, considering long-term improved patient outcome as the ultimate objective.

Duplex Ultrasound Evaluation for Dialysis access Selection and Maintenance: A Practical Guide

Detailed case directed history and examination is the mainstay of dialysis access modality selection, ie site and type of access, as well as for maintenance of dialysis access for longevity. As a logical step following history and physical examination, duplex ultrasound evaluation (DUE) is the most cost effective and non-invasive screening tool for evaluation for access placement and for assessment of an established access. Pre-operative vascular mapping allows selection of the optimal dialysis access modality and site. In established accesses, duplex ultrasound testing will diagnose the majority of vascular access complications and direct proper surgical or interventional radiology management. This review outlines a practical decision-making algorithm using DUE for choosing and managing the dialysis access.

Understanding the Dialysis access Steal Syndrome. A Review of the Etiologies, Diagnosis, Prevention and Treatment Strategies

Distal hypoperfusion ischemic syndrome (DHIS), commonly referred to as hand ischemia or “steal” after dialysis access placement, occurs in 5–10% of cases when the brachial artery is used, or 10 times that of wrist arteriovenous fistulas (AVFs) using the radial artery. It is typically seen in elderly women with diabetes, and may carry severe morbidity including tissue or limb loss if not recognized and treated. Three distinct etiologies include (1) blood flow restriction to the hand from arterial occlusive disease either proximal or distal to the AV access anastomosis, (2) excess blood flow through the AV fistula conduit (true steal), and (3) lack of vascular (arterial) adaptation or collateral flow reserve (ie atherosclerosis) to the increased flow demand from the AV conduit. These three causes of steal may occur alone or in concert. The diagnosis of steal is based on an accurate history and physical examination and confirmed with tests including an arteriogram, duplex Doppler ultrasound (DDU) evaluation with finger pressures and waveform analysis. Treatment of steal includes observation of developing symptoms in mild cases. Balloon angioplasty is the appropriate intervention for an arterial stenosis. At least three distinct surgical corrective procedures exist to counteract the pathophysiology of steal. The ultimate treatment strategy depends on severity of symptoms, the extent of patient co-morbidity, and the local dialysis access technical team support and skills available.

Understanding the dialysis access steal syndrome. A review of the etiologies, diagnosis, prevention and treatment strategies

Distal hypoperfusion ischemic syndrome (DHIS), commonly referred to as hand ischemia or 'steal' after dialysis access placement, occurs in 5-10% of cases when the brachial artery is used, or 10 times that of wrist arteriovenous fistulas (AVFs) using the radial artery. It is typically seen in elderly women with diabetes, and may carry severe morbidity including tissue or limb loss if not recognized and treated. Three distinct etiologies include (1) blood flow restriction to the hand from arterial occlusive disease either proximal or distal to the AV access anastomosis, (2) excess blood flow through the AV fistula conduit (true steal), and (3) lack of vascular (arterial) adaptation or collateral flow reserve (ie atherosclerosis) to the increased flow demand from the AV conduit. These three causes of steal may occur alone or in concert. The diagnosis of steal is based on an accurate history and physical examination and confirmed with tests including an arteriogram, duplex Doppler ultrasound (DDU) evaluation with finger pressures and waveform analysis. Treatment of steal includes observation of developing symptoms in mild cases. Balloon angioplasty is the appropriate intervention for an arterial stenosis. At least three distinct surgical corrective procedures exist to counteract the pathophysiology of steal. The ultimate treatment strategy depends on severity of symptoms, the extent of patient co-morbidity, and the local dialysis access technical team support and skills available.

Duplex ultrasound evaluation for dialysis access selection and maintenance: a practical guide

Detailed case directed history and examination is the mainstay of dialysis access modality selection, ie site and type of access, as well as for maintenance of dialysis access for longevity. As a logical step following history and physical examination, duplex ultrasound evaluation (DUE) is the most cost effective and non-invasive screening tool for evaluation for access placement and for assessment of an established access. Pre-operative vascular mapping allows selection of the optimal dialysis access modality and site. In established accesses, duplex ultrasound testing will diagnose the majority of vascular access complications and direct proper surgical or interventional radiology management. This review outlines a practical decision-making algorithm using DUE for choosing and managing the dialysis access.

A patient centered decision making dialysis access algorithm

Much controversy surrounds the establishment of proper planning, placement and management (the best practice pattern) of dialysis access. These include the dialysis type and modality selection, timing of access placement and who places the access. The lack of and the difficulty of performing randomized studies with multiple confounding factors, in an extremely heterogeneous and rapidly changing ESRD population demographics, only partly explains the dialysis access conundrum. Add to this the rapidly developing and competing technologies, the wide spectrum of the professional experience, bias and socio-economic forces to make the ESRD problems as multivariate and complex as life itself. This overview describes a dialysis access algorithm approach to the patient needing renal replacement therapy, considering long-term improved patient outcome as the ultimate objective.

Delayed onset of ascending paralysis after thoracic aortic stent graft deployment

Delayed spinal cord ischemia after thoracic aortic aneurysm repair is an infrequent but devastating complication. The use of stent grafts to exclude aortic aneurysms is thought to decrease the incidence of the neurologic deficit because there is no period of significant aortic occlusion. We report a case of paraplegia that progressed to quadriplegia occurring 48 hours after the apparently successful deployment of a thoracic aortic stent graft.

Comparison of the angiojet rheolytic catheter to surgical thrombectomy for the treatment of thrombosed hemodialysis grafts. Peripheral AngioJet Clinical Trial

PURPOSE

To compare the clinical effectiveness of the AngioJet F105 rheolytic catheter to that of surgical thrombectomy for the treatment of thrombosed hemodialysis grafts.

MATERIALS AND METHODS

This was a multicenter, prospective, randomized trial comparing technical success, primary patency, and complication rates. A total of 153 patients were enrolled: 82 patients in the AngioJet group and 71 patients in the surgical thrombectomy group. Patient follow-up was performed 24-48 hours, 1 month, and 6 months after the procedures.

RESULTS

Technical success, as defined by the patient's ability to undergo hemodialysis treatment, was 73.2% for the AngioJet group and 78.8% for the surgical thrombectomy group (P = .41). The primary patency rates of the AngioJet group were 32%, 21%, and 15% at 1, 2, and 3 months, respectively. The primary patency rates for the surgical group were 41%, 32%, and 26% at 1, 2, and 3 months, respectively. This difference approached statistical significance (P = .053). The groups had similar complication rates-14.6% in the AngioJet group and 14.1% in the surgery group-although the surgery group had more major complications (11.3%). In the AngioJet group, there was a transient increase in plasma-free hemoglobin, which normalized within 24-48 hours.

CONCLUSIONS

The AngioJet F105 catheter provides similar clinical results when compared to surgical thrombectomy for the treatment of thrombosed hemodialysis grafts. The difference in patency rates between these two techniques approached statistical significance. In addition, results of both thrombectomy methods were inferior to those suggested by the Dialysis Outcomes Quality Initiative guidelines.

Renal artery stent placement for the management of ischemic nephropathy

PURPOSE

To evaluate the angiographic and clinical results of percutaneously implanted renal artery endoprostheses (stents) for the treatment of patients with ischemic nephropathy.

MATERIALS AND METHODS

During a 52-month period, 45 patients with azotemia (serum creatinine > or = 1.5 mg/dL) and atheromatous renal artery stenosis untreatable by, or recurrent after, balloon angioplasty were treated by percutaneous placement of Palmaz stents. Stent implantation was unilateral in 32 cases and bilateral in 11 cases. Clinical results were determined by measurements of serum creatinine and follow-up angiography. Clinical benefit was defined as stabilization or improvement in serum creatinine level. Angiographic patency was defined as less than 50% diameter recurrent arterial stenosis.

RESULTS

Stent placement was technically successful in 51 of 54 (94%) renal arteries. Technical failures were stent misdeployment requiring percutaneous stent retrieval (n = 2) and inadvertent placement distal to the desired position (n = 1). Complications included acute stent thrombosis (n = 1) and early initiation of hemodialysis (within 30 days; n = 1). There were two periprocedural deaths. With use of life-table analysis, clinical benefit was seen in 78% of patients at 6 months (n = 36), 72% at 1 year (n = 24), 62% at 2 years (n = 12), and 54% at 3 years (n = 3). In patients with clinical benefit, average creatinine level was reduced from 2.21 mg/dL +/- 0.91 before treatment to 2.05 mg/dL +/- 1.05 after treatment (P = .018). Lower initial serum creatinine level was associated with a better chance of clinical benefit (P = .05). No other variables affected outcome, including patient age, sex, diabetes, implanted stent diameter, unilateral versus bilateral stent placement, or ostial versus nonostial stent positioning. Conventional catheter angiography or spiral computed tomographic (CT) angiography performed in 19 patients (28 stents) at a mean interval of 12.5 months demonstrated primary patency in 75%. Maintained stent patency appeared to correlate with renal functional benefit.

CONCLUSIONS

Percutaneous renal artery stent placement for angioplasty failures or restenoses provides clinical benefit in most patients with ischemic nephropathy.

Transjugular core liver biopsy with a 19-gauge spring-loaded cutting needle

One hundred and five sequential transjugular core liver biopsies (TJLBx) were performed in 101 patients with coagulopathy and/or ascites using the 19-gauge Quick-Core Biopsy (QCB) needle. Two-hundred and seventy-three cores were obtained in 295 passes (92. 5%). One-hundred and two of the 105 procedures (97.1%) led to a histopathologic diagnosis. One of the three nondiagnostic biopsies was done because of severe autolysis of the liver. There was one subcapsular hematoma, one hepatic arteriovenous fistula, and one liver capsular puncture. Two minor neck hematomas occurred. One death was reported (unrelated to the procedure). QCB needle TJLBx is an effective and relatively safe way to obtain core liver samples.

Combination "sandwich" therapy for extensive renal calculi in 100 consecutive patients: immediate, long-term and stratified results from a 10-year experience

PURPOSE

We determined the immediate and long-term efficacy of combination "sandwich" therapy for management of large, extensively branched calculi in 100 consecutively treated patients.

MATERIALS AND METHODS

We treated 61 women and 39 men for stones ranging from 2.2 to 66 cm2 (mean 20.8) with percutaneous debulking followed by shock wave lithotripsy and, when necessary, secondary nephroscopy via the mature tract. The primary debulking was performed via 1 to 3 tracts (total 106, mean 1.06 per patient), following which 1 to 3 shock wave treatments (total 127, mean 1.3 per patient) were administered. Subsequently, 62 patients underwent 71 secondary or tertiary percutaneous procedures (mean 1.1 per patient).

RESULTS

Total hospital stay ranged from 3 to 44 nights (mean 12.2) and decreased with experience. In 34 patients 40 complications developed, the most frequent of which were bleeding requiring transfusion in 14 patients and fever or sepsis delaying a planned procedure or hospital discharge in 20 patients. For patients with struvite stones the transfusion rate and fever/sepsis rate was 20 and 33%, respectively, compared to only 10 and 12%, respectively, for those patients with noninfection related stones. Of 87 patients available for 1-month radiographic followup 55 (63%) were stone-free, while 32 (37%) had discrete residual gravel. With time and experience, the stone-free rate improved from 52 to 70%. Of 55 patients followed for a mean of 40.5 months ipsilateral stones recurred in 13 (22.8%). Of 39 patients with struvite calculi 11 (28%) had recurrent bacteriuria or infection. Renal function, defined by serum creatinine, ranged from 0.6 to 3.9 mg./dl. (mean 1.3) before treatment and from 0.5 to 6.4 mg./dl. (mean 1.4) 1 to 101 months (mean 31) after treatment.

CONCLUSIONS

This combined sandwich approach offers immediate and long-term results comparable to other forms of management currently available for these challenging cases. Furthermore, this approach may be applied successfully to virtually any patient with large, extensively branched or otherwise complex stones.

Combination "sandwich" therapy for extensive renal calculi in 100 consecutive patients: immediate, long-term and stratified results from a 10-year experience

PURPOSE

We determined the immediate and long-term efficacy of combination "sandwich" therapy for management of large, extensively branched calculi in 100 consecutively treated patients.

MATERIALS AND METHODS

We treated 61 women and 39 men for stones ranging from 2.2 to 66 cm2 (mean 20.8) with percutaneous debulking followed by shock wave lithotripsy and, when necessary, secondary nephroscopy via the mature tract. The primary debulking was performed via 1 to 3 tracts (total 106, mean 1.06 per patient), following which 1 to 3 shock wave treatments (total 127, mean 1.3 per patient) were administered. Subsequently, 62 patients underwent 71 secondary or tertiary percutaneous procedures (mean 1.1 per patient).

RESULTS

Total hospital stay ranged from 3 to 44 nights (mean 12.2) and decreased with experience. In 34 patients 40 complications developed, the most frequent of which were bleeding requiring transfusion in 14 patients and fever or sepsis delaying a planned procedure or hospital discharge in 20 patients. For patients with struvite stones the transfusion rate and fever/sepsis rate was 20 and 33%, respectively, compared to only 10 and 12%, respectively, for those patients with noninfection related stones. Of 87 patients available for 1-month radiographic followup 55 (63%) were stone-free, while 32 (37%) had discrete residual gravel. With time and experience, the stone-free rate improved from 52 to 70%. Of 55 patients followed for a mean of 40.5 months ipsilateral stones recurred in 13 (22.8%). Of 39 patients with struvite calculi 11 (28%) had recurrent bacteriuria or infection. Renal function, defined by serum creatinine, ranged from 0.6 to 3.9 mg./dl. (mean 1.3) before treatment and from 0.5 to 6.4 mg./dl. (mean 1.4) 1 to 101 months (mean 31) after treatment.

CONCLUSIONS

This combined sandwich approach offers immediate and long-term results comparable to other forms of management currently available for these challenging cases. Furthermore, this approach may be applied successfully to virtually any patient with large, extensively branched or otherwise complex stones.

Preoperative radiological evaluation of the liver by computerized tomographic portography in patients with hepatic tumors

The main objective of preoperative imaging studies is to define as accurately as possible the number, size, location, and relationship of tumor masses in the liver to pertinent portal and hepatic venous vasculature. Computerized tomographic portography images hepatic veins and segmental portal vein branches and identifies the anatomical location of tumor nodules with excellent sensitivity and a low false-positive rate. The intraoperative correlation of computerized tomographic portography on 30 patients in the last 20 months at this institution shows a sensitivity of 88 per cent with a low rate of false-positivity. The ability to detect metastatic lesions in the liver by computerized tomographic portography diminishes when the lesions are noted to be less than 1 cm. The authors conclude that the preoperative interpretation of the computerized tomographic portogram provides valuable information not previously available to the surgeon operating on the liver.

Formyl peptide chemotactic receptor. Evidence for an active proteolytic fragment

We have developed a radioiodinated photoaffinity label, N-formyl-Nle-Leu-Phe-Nle-125I-Tyr-Lys-N-6-(4'-azido-2'-nitrophenylamino) hexanoate (where Nle represents norleucine) (125I-PAL), which forms a covalent complex with the formyl peptide chemotactic receptor of living human neutrophils. Labeling was 12 to 16% efficient and did not alter cell viability. The receptor on live neutrophils and neutrophil membranes has an apparent molecular weight of 50,000 to 70,000 by sodium dodecyl sulfate-polyacrylamide electrophoresis. The receptor on intact cells possesses one predominant papain cleavage site, yielding a 35,000-Da fragment. This receptor fragment retains an affinity for N-formyl-Nle-Leu-Phe-Nle-125I-Tyr-Lys indistinguishable from the receptor on control cells (KD = 1.9 and 1.8 nM, respectively). The 35,000-Da papain fragment was biologically active as evidenced by an unchanged dose-response curve for peptide-stimulated beta-glucuronidase release and fluorescent peptide uptake. Papain treatment of 125I-PAL-labeled neutrophil membranes or of digitonin-soluble 125I-PAL-labeled receptors produced a predominant 28,000-Da fragment without evidence of the 35,000-Da fragment seen with whole cells. Pronase, which did not cleave the receptor on intact cells, produced multiple receptor fragments when used to treat 125I-PAL-labeled membranes.