Richard J. Gray

Reporting Standards for Percutaneous Interventions in Dialysis Access

THE traditional treatment for failing arteriovenous dialysis access has been thrombectomy and/or surgical revision as needed (1–3). Over the past 2 decades, percutaneous methods for thrombus dissolution and/or correction of anatomic abnormalities have become accepted alternate treatment modalities (4). The results of thrombolysis (5–9), angioplasty (10–14), directional atherectomy (15,16), and endoluminal stent deployment (17–22) have been reported widely; nevertheless, comparison and interpretation of results are difficult because of differing methods of patient selection, treatment, and follow-up. For example, some thrombolysis series report success as establishment of flow immediately after the procedure (5), whereas others require at least three dialysis sessions after treatment for success (8). In addition, different reporting methods (life-table mean patency, life-table 50% patency, arithmetic mean patency, etc) applied to the exact same database can result in dramatically different conclusions; Hodges et al (23) showed that autogenous fistulas could be interpreted to have patencies equal to those of polytetrafluoroethylene (PTFE) grafts, shorter than PTFE grafts, or twice as long as PTFE grafts, depending on the method of data analysis. Suggested standards for reporting the results of arterial revascularization have been published previously by the Journal of Vascular Surgery (24,25) and the Journal of Vascular and Interventional Radiology (26,27). Reporting standards for acute and chronic thromboembolic venous disease have also been suggested (28). These reporting standards are obviously an imperfect fit for dialysis access interventions. To our knowledge, there has been no publication suggesting uniform reporting standards for dialysis access revascularization despite calls for their establishment (23,29). The purpose of this document is to recommend standards to be used for study design and reporting of percutaneous interventions for permanent hemodialysis access. The Table summarizes these standards in an abbreviated format.

Quality Improvement Guidelines for Percutaneous Management of the Thrombosed or Dysfunctional Dialysis Access

John E. Aruny, MD, Curtis A. Lewis, MD, John F. Cardella, MD, Patricia E. Cole, PhD, MD, Andrew Davis, MD, Alain T. Drooz, MD, Clement J. Grassi, MD, Richard J. Gray, MD, James W. Husted, MD, Michael Todd Jones, MD, Timothy C. McCowan, MD, Steven G. Meranze, MD, A. Van Moore, MD, Calvin D. Neithamer, MD, Steven B. Oglevie, MD, Reed A. Omary, MD, Nilesh H. Patel, MD, Kenneth S. Rholl, MD, Anne C. Roberts, MD, David Sacks, MD, Orestes Sanchez, MD, Mark I. Silverstein, MD, Harjit Singh, MD, Timothy L. Swan, MD, Richard B. Towbin, MD, Scott O. Trerotola, MD, Curtis W. Bakal, MD, MPH, for the Society of Interventional Radiology Standards of Practice Committee

Percutaneous Fibrin Sheath Stripping versus Transcatheter Urokinase Infusion for Malfunctioning Wellpositioned Tunneled Central Venous Dialysis Catheters: A Prospective, Randomized Trial

PURPOSE To compare central dialysis catheter patency rates after stripping procedures with those after urokinase (UK) infusion. MATERIALS AND METHODS Fifty-seven tunneled catheters with either (i) flow rates less than 250 mL/min and established baseline flow rates > or = 300 mL/min or (ii) flow rates 50 mL/min less than higher established baseline flows were prospectively randomized to undergo stripping procedures (n = 28) or UK infusion (n = 29) at 30,000 U/h via each port concurrently, for a total 250,000 U. Success and patency were determined by dialysis at normal flow rates (> or = 300 mL/min) or at the previously established higher baseline rate. Flow rates were monitored weekly. Primary patency ended with catheter malfunction or removal. Kaplan-Meier survival analysis was used to construct survival curves. RESULTS In the stripping group, initial clinical success was 89% (25 of 28). The 15-, 30-, and 45-day primary patency rates were 75% (n = 20), 52% (n = 13), and 35% (n = 8), respectively. The median duration of additional function was 32 days (95% CI: 18-48 d). In the UK group, initial clinical success was 97% (28 of 29). The 15-, 30-, and 45-day primary patency rates were 86% (n = 21), 63% (n = 13), and 48% (n = 9), respectively. The median duration of additional patency was 42 days (95% CI: 22-153 d). The Wilcoxon test for equality detected no significant difference in the survival curves for the two treatment groups (P = .236). CONCLUSION There is no significant difference in time to primary patency between the two methods. Both allow temporary catheter salvage in most patients.

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.

SIR Reporting Standards for the Treatment of Acute Limb Ischemia with Use of Transluminal Removal of Arterial Thrombus

ACUTE limb ischemia is any sudden decrease or worsening in limb perfusion that causes a potential threat to limb viability (1). Acute peripheral arterial occlusion may be caused by in situ thrombosis or embolus. In this article, the term “thrombus” will be used to describe arterial occlusion caused by in situ thrombosis or embolus. Percutaneous or “open” surgical techniques can be used to remove the thrombus. Current percutaneous methods for transluminal removal of thrombus (TRT) include thrombolytic therapy (ie, catheter-directed, pharmacomechanic), percutaneous aspiration thrombectomy (PAT), and percutaneous mechanical thrombectomy (PMT). These methods may be used in combination. Surgical techniques entail an “open” procedure that necessitates an arteriotomy for the removal of thrombus. Of the various TRT methods used to treat acute limb ischemia, catheterdirected thrombolytic therapy with urokinase has been the most widely studied. Catheter-directed thrombolytic therapy has at least three theoretical and practical advantages over surgical thromboembolectomy: less endothelial trauma, angiographic visualization of the underlying lesion(s) and runoff vessels, and, in many cases, ready access for definitive transluminal therapies that address the underlying lesion (1,2). In addition, it has been suggested that gradual, lowpressure reperfusion may offer certain advantages over sudden, high-pressure reperfusion associated with surgical revascularization (1,3,4). Recently, the Food and Drug Administration recalled urokinase (Abbokinase; Abbott Laboratories, Abbott Park, IL). As a result, a critical evaluation of alternate methods to treat acute limb ischemia with use of other thrombolytic drug strategies, PAT and/or PMT, will be needed. Reporting standards for the treatment of peripheral arterial disease (PAD) and practice guidelines for thrombolytic therapy for acute limb ischemia have been published (1,2,5– 7). However, there is insufficient evidence in the literature to determine the best therapy in a given case of acute limb ischemia. This is because the literature is replete with individual or institutional reports of surgical and thrombolytic therapy that are either biased or lack concurrent controls and standardized reporting practices (1). The purpose of this document is to establish reporting standards for subsequent studies pertaining to TRT in the treatment of acute limb ischemia. Consistent data reporting is needed to help precisely define the safety, efficacy, and long-term outcome of TRT procedures (1,8,9). Only then can the appropriate treatment be determined for patients presenting with acute limb ischemia.

Directional Atherectomy Treatment for Hemodialysis Access: Early Results☆

The Simpson atherectomy device was used to treat 12 intragraft stenoses, six complete subclavian vein occlusions, and 14 venous outflow stenoses in 24 patients undergoing hemodialysis. Patients were followed up clinically and by means of venography at approximately 1, 3, 6, 9, and 12 months after treatment. Twenty-eight atherectomy specimens were examined histologically. Twenty-six (81%) of 32 lesions were treated with initial technical success. Including technical failures, seven (58%) of 12 intragraft stenoses are angiographically patent at a mean of 5.0 months and five (50%) of 10 are clinically patent at 6 months. Three (50%) of six subclavian veins are angiographically patent at a mean of 5.6 months, and four (67%) of six are clinically patent at 6 months. Three (21%) of 14 venous outflow stenoses are angiographically patent at a mean of 5.0 months and five (38%) of 13 are clinically patent at 6 months. Histologic examination showed neointimal fibromuscular hyperplasia in 26 of 28 lesions. When 30% or less angiographic residual stenosis is used as the criterion for initial technical success, directional atherectomy appears to be effective therapy for intragraft stenoses and, with balloon angioplasty, for some catheter insertion-related subclavian occlusions. Directional atherectomy appears to have a recurrence rate for venous outflow stenoses similar to that for balloon angioplasty when the same criterion is used.

Treatment of Anastomotic Bypass Graft Stenosis with Directional Atherectomy: Short-term and Intermediate-term Results☆

PURPOSE Areas of anastomotic stenosis in lower-extremity bypass grafts (BPGs) were treated by means of directional atherectomy (DA) in hopes of achieving better patency rates than have been reported with percutaneous transluminal angioplasty (PTA). MATERIALS AND METHODS During a 4-year period, 17 patients (11 men and six women) with 23 areas of anastomotic stenosis in 18 lower-extremity BPGs were selected for treatment with DA. Urokinase thrombolysis was initially performed in eight BPGs that were thrombosed at the time of presentation. Adjunctive preatherectomy PTA was performed in six lesions, and postatherectomy PTA was performed in three lesions. RESULTS The technical success rate for DA was 92% (23 of 25 sites). There was less than 50% restenosis at 74% of the areas of stenosis (14 of 19 sites), with a mean follow-up time for the sites of 13 months. The graft patency rate was 88% (14 of 16 grafts), with a mean follow-up time for the grafts of 14 months. Areas of stenosis treated with DA alone had the same patency rates as those treated with DA and PTA. CONCLUSIONS DA is an effective treatment method for anastomotic peripheral arterial BPG stenosis. The intermediate-term patency rates following DA are superior to those reported for PTA and similar to those reported for surgical revision.

Interventional care of the hemodialysis patient: it's about quality.

OVER the past two decades, Interventional Radiology has developed into an essential provider of percutaneous creation and management of access in hemodialysis patients. The role of interventional radiology in this patient population has developed into a broad range of procedures, including catheter placement and management, preoperative imaging for access, screening of and prophylactic intervention for failing hemodialysis conduits and fistulas, treatment of thrombosed conduits and fistulas, and salvage procedures designed to enhance the maturation of native fistulas. The development and proliferation of these interventions has been accomplished almost exclusively by interventional radiologists. These interventions are so integral to the care of the patient receiving hemodialysis treatment that they are strongly supported by the Dialysis Outcomes Quality Initiative (DOQI) Vascular Access Guidelines, published in 1997 (1) and updated in 2001 (2). Undoubtedly, the last thing interventional radiologists want to hear is the rumbling of another turf battle, but that is precisely what is happening in the area of hemodialysis access interventions. For many years, a very small group of nephrologists “borrowed” from our well-recognized name and began calling themselves “interventional nephrologists.” Until recently, the “interventional nephrology” movement was a small blip on the radar screen, but now, for a variety of reasons discussed herein, there is increased interest in this area from the nephrology community. Gradually, throughout the late 1990s, manuscripts published by “interventional nephrologists” became more frequent, billing for percutaneous procedures by the same specialists increased, and attention to this subject at nephrology meetings increased dramatically. In fact, there has been a hands-on course in “interventional nephrology” at the American Society of Nephrology meeting for the past three years. The year 2000 marked a turning point, and arguably the true onset of the “turf battle” over hemodialysis access interventions. In January of that year, the American Society of Nephrology and Renal Physicians Association published a document outlining training guidelines for nephrology fellowships, which include “interventional nephrology,” clearly defined and covering the entire spectrum of interventions currently performed by interventional radiologists in this patient population (3). Later in the year, the formation of the American Society of Interventional Nephrology was announced. Also during 2000, a proliferation of freestanding “interventional nephrology” centers, largely Baxter’s RMS Lifelines, allowed nephrologists to bypass hospital credentials committees by performing interventions outside of the hospital setting. Until this point, nephrologists had largely been unable to receive credentials for percutaneous interventions precisely because of their lack of training, which was obvious to even the most liberal credentials committee. “Training centers” are now available to nephrologists in several places throughout the country (4,5) where a 2-week course is considered “acceptable training” to allow performance of these procedures. The quote at the beginning of this Commentary reflects this sentiment. To make matters worse, medical device manufacturers are promoting the concept, offering 1and 2-day “training courses” to nephrologists, cardiologists, and surgeons; one of the authors of this article has been approached repeatedly to provide such “training.” If this sounds far-fetched, or if the reader is thinking, “this won’t happen here,” consider the following: Late this year, the Society of Cardiovascular & Interventional Radiology (SCVIR) From the Department of Radiology (S.O.T.), University of Pennsylvania Medical Center, Philadelphia, Pennsylvania; Department of Radiology (R.D.G.), Washington Hospital Center, Washington, DC; Department of Radiology (M.B.), Swedish Covenant Hospital, Chicago, Illinois, and Department of Radiology (S.A.), Open Access Vascular Access Center, Miami, Florida. Address correspondence to S.O.T., Department of Radiology, Hospital of the University of Pennsylvania, 1 Silverstein, 3400 Spruce St., Philadelphia, PA 19104; E-mail: streroto@uphs.upenn.edu

Phase I Results of Pullback Atherectomy for Hemodialysis Access

PURPOSE Balloon angioplasty and directional atherectomy frequently have short-lived results for stenoses associated with hemodialysis. Results are reported for a phase I trial of the pullback atherectomy catheter (PAC) for treatment of hemodialysis access-related stenoses. PATIENTS AND METHODS Six intragraft and six venous stenoses in nine patients were treated with the PAC. Two lesions were treated with adjunctive balloon angioplasty, and two were treated with adjunctive directional atherectomy. Clinical and angiographic follow-up were obtained for all patients. All specimens were examined histologically. RESULTS Initial procedural success was achieved in 83% of stenoses (10 of 12). For intragraft stenoses, the 6-month primary patency was 60% (three of five) and the 6-month secondary patency was 80% (four of five). All six venous stenoses restenosed or thrombosed within 3 months. All specimens contained fibrous plaque or intimal hyperplasia. In addition, all six venous stenosis specimens contained media and two contained adventitia. Significant complications during treatment of venous stenoses included severe venous spasm in three and venous pseudoaneurysms in two. One PAC tip fracture occurred during treatment of an intragraft stenosis. CONCLUSION Pullback atherectomy is potentially safe and effective for intragraft stenoses; however, it is not safe or effective for venous stenoses.

Fluoroscopically guided peritoneal catheter placement for intraperitoneal chemotherapy.

PURPOSE Surgical placement of intraperitoneal catheters for intraperitoneal chemotherapy is associated with bowel perforation, peritonitis, and catheter occlusion. The authors evaluated the safety and efficacy of fluoroscopically guided placement of temporary intraperitoneal catheters for chemotherapy. PATIENTS AND METHODS Two hundred one intraperitoneal catheter placements were attempted in 88 patients with peritoneal carcinomatosis or sarcomatosis. The peritoneum was punctured with 22-gauge needles and exchange was made with use of Seldinger technique and liberal injections of contrast material at each step for 8.3- or 8.5-F multiple-side-hole catheters. Placement sites included all four quadrants and the midline. Computed tomographic (CT) peritoneography was performed prior to chemotherapy. RESULTS One hundred ninety (94.5%) of 201 attempted catheter insertions were technically successful. Results of CT peritoneography were available in 175 cases and showed free distribution of peritoneal contrast material in 39% (n = 69), partial loculation in 38% (n = 67), and extensive loculation in 22% (n = 39). Catheters remained in place for a median of 5 days (range, 2-6 days). Significant complications occurred in 11 procedures (5.5%). There were seven unintended bowel intubations; all were treated conservatively except one that required surgical repair. One other patient developed necrotizing fasciitis requiring surgical débridement. Three other patients (1.5%) developed mild peritonitis responsive to antibiotics. Technical success, complications, and peritoneal distribution of contrast material did not correlate with the site of catheter placement. CONCLUSION Percutaneous catheter placement with use of small-gauge needles for initial puncture is safe and efficacious in patients requiring short-term peritoneal access for chemotherapy.