Atelocollagen Scaffold Enhances Cartilage Regeneration in Osteochondral Defects: A Study in Rabbits.

BACKGROUND: To enhance articular cartilage healing, microfractures (Mfx) and bone marrow aspirate concentrate (BMAC) are commonly used, and some form of scaffold is often used together to increase its efficacy. Herein, we compared the efficacy of atelocollagen scaffold to that of collagen scaffold when used with Mfx or BMAC on osteochondral defect of animal. METHODS: This experiment was designed in two stages, and therapeutic effects of Mfx and BMAC were respectively evaluated when used with atelocollagen or collagen scaffold. Femoral condyle defects were artificially created in male New Zealand White rabbits, and in each stage, 12 rabbits were randomly allocated into three treatment groups: test group with additional atelocollagen scaffold, the positive control group with collagen scaffold, and the negative control group. Then, for 12 weeks, macroscopic and histological evaluations were performed. RESULTS: At 12 weeks, defects in the test group were fully regenerated with normal cartilage-like tissue, and were well integrated with the surrounding cartilage at both stages experiment, whereas defects in the control groups were not fully filled with regenerated tissue, and the tissue appeared as fibrous tissue. Histologically, the regenerated tissue in the test group showed a statistically significant improvement compared to the positive and negative control groups, achieving a similar structure as normal articular cartilage. CONCLUSION: The results showed that implantation of the atelocollagen scaffold enhanced cartilage regeneration following osteochondral defects in rabbits. This suggests that the atelocollagen scaffold can be used with Mfx or BMAC for effective regeneration of osteochondral defects.

Intra-Articular Atelocollagen Injection for the Treatment of Articular Cartilage Defects in Rabbit Model.

BACKGROUND: Atelocollagen is widely recognized as a biomaterial for regenerative medicine because of its good compatibility and low antigenicity. Injury of the outermost layer of articular cartilage, known as the lamina splendens, can lead to osteoarthritis (OA) and eventually full-thickness cartilage loss. The intra-articular injection of atelocollagen has been designed to restore the cartilage layer and cartilage defects in OA joints. In this study, we investigated the efficacy of atelocollagen as a cartilage supplement for joint defects. METHODS: In this study, we evaluated the therapeutic effects of atelocollagen in animals with cartilage defects. Femoral groove defects were artificially created in 12 male New Zealand white rabbits, which were treated with intra-articular injection of either atelocollagen (experimental) or normal saline (control). The results were observed 3, 6, 9, and 12 weeks following macroscopic and histological evaluations. RESULTS: At 3 weeks, cartilage tissue was restored in the experimental group, whereas the control group did not show signs of restoration. At 12 weeks, defects in both groups were filled with regenerated tissue, but the experimental group displayed a morphologically better appearance. Histologically, the regenerated tissue in the experimental group showed statistically significant improvement compared to the control group, with a structure similar to that of normal articular cartilage. CONCLUSION: The results showed that the intra-articular injection of atelocollagen enhanced cartilage regeneration following rabbit patellar groove defects. Therefore, intra-articular injection of atelocollagen can be used as an effective supplement for joint defects.

The Effect of Faster Reporting Speed for Imaging Studies on the Number of Misses and Interpretation Errors: A Pilot Study.

PURPOSE: The purpose of the study was to determine if increasing radiologist reading speed results in more misses and interpretation errors. METHODS: We selected a sample set of 53 abdomen-pelvis CT scans of variable complexity performed at a teaching hospital during the study period. We classified the CT scans into 4 categories based on their level of difficulty, with level 4 representing the most-complex cases. Five attending radiologists participated in the study. We initially established an average baseline reporting time for each radiologist. Radiologists were randomly assigned a set of 12 studies, of varying complexity, to dictate at their normal speed, and a separate set of 12 studies, of similar complexity, to read at a speed that was twice as fast as their normal speed. The major and minor misses were recorded and analyzed. A χ(2) analysis was used to compare the results. RESULTS: Reading at the faster speed resulted in more major misses for 4 of the 5 radiologists. The total number of major misses for the 5 radiologists, when they reported at the faster speed, was 16 of 60 reported cases, versus 6 of 60 reported cases at normal speed; P = .032. The average interpretation error rate of major misses among the 5 radiologists reporting at the faster speed was 26.6%, compared with 10% at normal speed. CONCLUSIONS: Our pilot study found a significant positive correlation between faster reading speed and the number of major misses and interpretation errors.

Job satisfaction of program directors in radiology: a survey of current program directors.

OBJECTIVE: Informal conversations and anecdotal evidence suggest that the job turnover rate among radiology residency program directors is disproportionately high. The purpose of our study was to assess the characteristics of current program directors and determine factors that may be affecting overall job satisfaction and job turnover rate. SUBJECTS AND METHODS: A survey that combined facet-specific measurements and global assessment was sent to current program directors in Accreditation Council for Graduate Medical Education (ACGME)-approved diagnostic radiology programs. An optional free response section was included. Results were collected over 4 weeks. RESULTS: Most of the program directors responded. The mean tenure of current program directors was 6.9 ± 6.7 years (range, 0.5-30 years). Fifty-three percent rated global job satisfaction high, and 6% reported low satisfaction. Sixty-four percent of the respondents were not considering resignation, compared with 13% who were definitely resigning. Program directors in larger programs reported a higher level of satisfaction. Positive interactions with residents and feeling valued by colleagues increased job satisfaction. The greatest source of dissatisfaction from all respondents seemed to be ACGME regulations, which were considered excessive and to change too frequently. The changing format of the board examination and structure of a residency were not the major factors in determining job satisfaction. CONCLUSION: The job satisfaction rate among current program directors is high, likely owing to feelings of fulfillment in working with residents and feeling valued by colleagues. The major source of dissatisfaction appears to stem from ACGME oversight, which is perceived as excessive and having requirements that change too frequently.

The biceps muscle from shoulder to elbow.

The biceps brachii plays an integral role in movement of the shoulder and elbow, and pathology can occur in athletes of all ages. Injuries of the proximal biceps tendon can be seen in overhead athletes as a result of chronic impingement, tendon instability, or tensile overload, often with accompanying lesions of the labrum or rotator cuff. Presentation may be insidious or can be precipitated by an acute event. Injuries to the distal biceps are more common in athletes involved in strength training such as weightlifters, or occasionally in contact sports. Although injury to the proximal and distal biceps can often be diagnosed clinically, MRI is an excellent imaging modality to evaluate the extent of disease and involvement of adjacent structures. This article reviews the anatomy of the biceps brachii from the shoulder to elbow and discusses commonly occurring pathology of the biceps and adjacent anatomical structures.

Nonoperative thoracic duct embolization for traumatic thoracic duct leak: experience in 109 patients.

OBJECTIVE: To demonstrate the efficacy of a minimally invasive, nonoperative, catheter-based approach to the treatment of traumatic chyle leak. METHODS: A retrospective review of 109 patients was conducted to assess the efficacy of thoracic duct embolization or interruption for the treatment of high-output chyle leak caused by injury to the thoracic duct. RESULTS: A total of 106 patients presented with chylothorax, 1 patient presented with chylopericardium, and 2 patients presented with cervical lymphocele. Twenty patients (18%) had previous failed thoracic duct ligation. In 108 of 109 patients, a lymphangiogram was successful. Catheterization of the thoracic duct was achieved in 73 patients (67%). In 71 of these 73 patients, embolization of the thoracic duct was performed. Endovascular coils or liquid embolic agent was used to occlude the thoracic duct. In 18 of 33 cases of unsuccessful catheterization, thoracic duct needle interruption was attempted below the diaphragm. Resolution of the chyle leak was observed in 64 of 71 patients (90%) post-embolization. Needle interruption of the thoracic duct was successful in 13 of 18 patients (72%). In 17 of the 20 patients who had previous attempts at thoracic duct ligation, embolization or interruption was attempted and successful in 15 (88%). The overall success rate for the entire series was 71% (77/109). There were 3 (3%) minor complications. CONCLUSION: Catheter embolization or needle interruption of the thoracic duct is safe, feasible, and successful in eliminating a high-output chyle leak in the majority (71%) of patients. This minimally invasive, although technically challenging, procedure should be the initial approach for the treatment of a traumatic chylothorax.

Embryonic inbreeding depression varies among populations and by mating system in Witheringia solanacea (Solanaceae).

PREMISE OF THE STUDY: Embryonic inbreeding depression is a key influence on mating system evolution and can be difficult to estimate in self-incompatible species. A pollen chase experiment was used to estimate the magnitude of embryonic inbreeding depression in Costa Rican Witheringia solanacea, a species polymorphic for self-incompatibility (SI). In a pollen chase experiment, bud self-pollinations are followed after anthesis by outcross pollinations, with a comparable pair of outcross pollinations used as a control. Lowered seed set for the self-precedence treatment indicates embryonic inbreeding depression. • METHODS: Embryonic inbreeding depression was assayed for self-compatible (SC) individuals and for SI plants from two populations that differ quantitatively in the onset and enzymatic activity of their SI response. Microsatellite markers were used to assay the selfing rate of a sample of surviving progeny from the prior self-pollination treatment. • KEY RESULTS: SC individuals showed no evidence of embryonic inbreeding depression. In SI plants, prior self-pollination reduced seed number by 28-70%, depending on population. Microsatellite genotyping revealed that embryonic inbreeding depression was even more severe than estimated by the phenotypic data: for mature fruits resulting from self-pollination precedence, the majority of the progeny were the result of outcross fertilization. • CONCLUSIONS: Lineage-specific purging of recessive lethals has accompanied the evolution of SC in this species. SI populations show contrasting levels of embryonic inbreeding depression, with nearly complete embryonic lethality upon selfing in the Monteverde population. In the face of high embryonic inbreeding depression, an increase in selfing rate can evidently occur only under severe pollen limitation.

The case for primary placement of tunneled hemodialysis catheters in acute kidney injury.

PURPOSE: Nontunneled hemodialysis catheters (NTDCs) are widely used for initial hemodialysis access in new-onset renal failure. The National Kidney Foundation recommends NTDC use for hemodialysis duration of less than 1 week in acute kidney injury because of the increased infection risk compared with tunneled hemodialysis catheters (TDCs) with longer use. The present study was performed to determine whether primary placement of TDCs in this setting is more appropriate, and whether there are predictors of recovery of renal function in less than 1 week. MATERIALS AND METHODS: In the authors' practice, patients referred to the interventional radiology unit in whom no contraindications exist receive a TDC; 76 patients who received a primary TDC for acute kidney injury and who eventually recovered renal function were retrospectively reviewed herein. Causes of renal failure, various renal function parameters, and demographics were collected, as were TDC dwell times, in an effort to determine predictors of recovery and/or extended duration of use. RESULTS: Mean TDC dwell time in patients who eventually recovered from acute kidney injury was 34 days; only 15 of 76 (20%) recovered within 1 week. At TDC placement, there were no significant differences between patients who recovered in less than (vs greater than) 1 week. CONCLUSIONS: The present results support primary placement of TDCs in patients with acute kidney injury who require hemodialysis and in whom no contraindications exist, as no predictors of recovery of renal function in less than 1 week were identified.

Incidence and management of percutaneous transluminal angioplasty-induced venous rupture in the "fistula first" era.

PURPOSE: Percutaneous transluminal angioplasty (PTA)-induced venous rupture is a common complication of hemodialysis access interventions. The authors sought to determine if venous rupture rates and management differed between grafts and fistulas, and in the fistula subset, between transposed and nontransposed fistulas. MATERIALS AND METHODS: Patients experiencing venous rupture during hemodialysis PTA over a 5-year period were identified. Of 1,985 hemodialysis interventions, 75 ruptures occurred in 69 patients (46 women) with a mean age of 63 years (range, 31-88 y). Rupture rates, proportion of successful treatments, and treatment type and number (ie, balloon tamponade, stent, covered stent) were determined. RESULTS: Rupture was more common in fistulas overall (5.6%, 39 of 693) compared with grafts (2.8%, 36 of 1,292; P = .002), in transposed (10.7%, 20 of 187) compared with nontransposed fistulas (3.8%, 19 of 506; P = .001), and in transposed fistulas compared with grafts (P = .0001). There was no significant difference between nontransposed fistulas and grafts. Treatment success (ie, resolution of extravasation) was the same among groups: 69% (27 of 39) in fistulas overall, 70% (14 of 20) in transposed fistulas, 68% (13 of 19) in nontransposed fistulas, and 72% (26 of 36) in grafts. There was a greater need for stents in grafts (38.9%, 14 of 36) compared with fistulas (12.8%, five of 39; P = .003). CONCLUSIONS: PTA-induced rupture is more common in fistulas than grafts, and this effect seems nearly entirely driven by transposed fistulas. Although rupture treatment in fistulas of all types yielded similar success to grafts, and graft ruptures were more difficult to treat than fistula ruptures, the high rupture rates in transposed fistulas attest to the increased difficulty of treating this subset of fistulas.

Angiographic changes following the use of a purse-string suture hemostasis device in hemodialysis access interventions.

PURPOSE: To evaluate late angiographic changes at the puncture site with use of a suture lock device for hemostasis after hemodialysis access interventions. MATERIALS AND METHODS: Thirty-five patients who underwent percutaneous intervention of a failing or thrombosed access had 76 puncture sites (58 grafts, 15 fistulas, three composite) managed with a purse-string suture lock device. All patients had follow-up fistulograms available for analysis. Fistulograms at the site of sheath insertion were retrospectively compared with those obtained during subsequent hemodialysis access procedures to assess for changes in access lumen diameter. Access type, sheath size, and heparin dose were examined as predictors of access diameter change at the puncture site. RESULTS: The mean time to follow-up fistulography was 4.7 months; the cumulative observation time of the patient cohort was 30.5 dialysis years. The mean change in access diameter at the previous puncture site was -0.3%. No puncture sites became aneurysmal or stenotic during follow-up. Two of the 76 puncture sites (both grafts) developed mild (+28%) and moderate (+43%) bulging at the sheath site. The remaining 74 puncture sites (97%) showed no significant change in access diameter. The mean change in access diameter among fistulas was -6.2%, and that among grafts was +1.5% (P = .06). Neither sheath size (P = .26) nor heparin dose (P = .48) had an effect on access diameter. CONCLUSIONS: No patients developed aneurysms or stenosis at the puncture site after use of a suture lock device for hemostasis. This technique is consistent, safe, and effective in obtaining hemostasis after dialysis access interventions of fistulas and grafts.

The written clinical diagnosis board examination: survey of program director and resident opinions.

OBJECTIVE: The purpose of our study was to assess the perceived value of the American Board of Radiology written clinical diagnosis board examination. MATERIALS AND METHODS: Two online surveys were distributed to diagnostic radiology programs approved by the Accreditation Council for Graduate Medical Education. Program directors were asked about the importance of the examination, and residents were asked about the importance and composition (proportion of repeated questions, known as recalls) of the examination and about preparation strategies. RESULTS: Most of the program directors (122 of 178, 69%) responded. Most of the respondents believed that the examination correlated with their assessment of residents' knowledge, that passing was indicative of a qualified radiologist, and that the examination should not be eliminated. Although most of the program directors believed preparation increased residents' knowledge, they also believed that preparation detracted from reading assignments. Opinion was divided whether the examination should be continued in its present form. The majority of the 171 resident respondents spent most of their time studying recalls, which they believed made up 40-60% of the examination. One half of the residents believed that preparing helped in mastering the body of radiology knowledge, although most believed that core material made up only 20-60% of the examination. A minority of the residents considered passing the examination indicative of a qualified radiologist. Opinion was divided on continuing the examination in its present form. CONCLUSION: Program directors and residents perceived value in the written clinical diagnosis board examination. The American Board of Radiology may need to reevaluate question content when restructuring the new examination.

Preoperative mapping venography in patients who require hemodialysis access: imaging findings and contribution to management.

PURPOSE: To analyze the use of preoperative venographic mapping in patients who require permanent hemodialysis access. MATERIALS AND METHODS: Ninety-one patients underwent 108 preoperative studies. Sixty-eight (75%) were documented to have ongoing or previous hemodialysis at the time of the study. A total of 154 arms were assessed with venograms (75 right, 79 left); 74 of the patients (81%) had previous access. Venographic mapping was not performed in patients with clearly usable veins as determined by the referring surgeon. RESULTS: A total of 170 veins were suitable for access creation (ie, continuous vein of suitable caliber). Of these, 78 were used (40 fistulas [51%] and 38 grafts [49%]), and 87% of accesses were successfully used for dialysis (73% primarily, 14% after additional intervention). Anatomic variants included early brachial-basilic confluence (44%), double terminal cephalic arch (4%), and brachial-basilic "ladders" (7%). Significant central venous stenosis was found in 10% of studies, limiting the ability to use the affected side for access. There were significant associations between (i) the number of previous accesses and access type created (P = .002, Fisher exact test) and (ii) the number of veins visualized and access type created (P < .001, Fisher exact test). A greater number of previous access attempts correlated with graft rather than fistula placement for permanent access, and increased numbers of veins seen on venography correlated with an increased chance of permanent access placement. CONCLUSIONS: Venography may identify clinically occult veins usable for hemodialysis access. Anatomic variants are common and may affect choice of access site.

Large or small bore, push or pull: a comparison of three classes of percutaneous fluoroscopic gastrostomy catheters.

PURPOSE: To compare the tube performance and complication rates of small-bore, large-bore push-type, and large-bore pull-type gastrostomy catheters. MATERIALS AND METHODS: A total of 160 patients (74 men, 86 women; mean age, 66.9 years, range, 22-95 y) underwent percutaneous fluoroscopic gastrostomy placement between January 2004 and March 2006. Choice of catheter was based on the preference of the attending radiologist. Data were collected retrospectively with institutional review board approval. Radiology reports provided information on the catheter, indication for gastrostomy, technical success, and immediate outcome. Chart review provided data on medical history, postprocedural complications, progress to feeding goal, and clinical outcomes. Statistical analysis was performed to compare the three classes of gastrostomy catheters. RESULTS: All 160 catheters were placed successfully. Patients who received small-bore catheters (14 F; n = 88) had significantly more tube complications (17% vs 5.6%) and were less likely to meet their feeding goal (P = .035) compared with patients with large-bore catheters (20 F; n = 72). No difference was observed in terms of major or minor complications. Large-bore push-type (n = 14) and pull-type catheters (n = 58) were similar in terms of complication rates. Patients who received large-bore push-type catheters achieved their feeding goals in significantly less time than those with large-bore pull-type catheters (average, 3.8 days vs 6.0 days; P = .04). CONCLUSIONS: Patients who received small-bore gastrostomy catheters are significantly more prone to tube dysfunction. Large-bore catheters should be preferentially used, with push-type catheters performing better with regard to the time to achieve feeding goal.

Salvage of nonmaturing native fistulas by using angioplasty.

PURPOSE: To retrospectively review outcomes following angioplasty of nonmaturing autogenous hemodialysis fistulas. MATERIALS AND METHODS: Institutional review board exemption was received for this HIPAA-compliant retrospective study; informed consent was waived. During 48 months, 101 patients underwent fistulography for percutaneous salvage of nonmaturing native fistulas. Clinical and technical success, need for secondary interventions, and complications were recorded according to consensus definitions. Patency following angioplasty was estimated with the Kaplan-Meier technique. Patient age, sex, ethnicity, fistula age, fistula type, number of stenoses, maximal angioplastic balloon diameter used, and presence of palpable thrill following angioplasty were examined as predictors of primary patency of the fistula following intervention by using Cox proportional hazards model. RESULTS: Mean patient age was 58 years; 35% were women. Median time from fistula creation to fistulography was 2.5 months. Hemodynamically significant (>50%) stenoses were identified in 88% (89 of 101) of patients; angioplasty was attempted in 96% (85 of 89). Technical success was achieved in 92% (78 of 85) of fistulas following angioplasty; clinical success of normal hemodialysis with total access blood flow of more than 500 mL/min occurred following 88% (75 of 85) of angioplastic interventions. No major and two minor complications occurred. Mean primary unassisted patency at 3, 6, and 12 months was 60%+/-6% (95% confidence interval), 45%+/-6%, and 34%+/-6%, respectively. Additional angioplasty (n=12), stent placement (n=1), or thrombectomy (n=1) during subsequent interventions resulted in mean secondary patency at 3, 6, and 12 months of 82%+/-4%, 79%+/-5%, and 75%+/-6%, respectively. Patients without thrill following angioplasty were more than twice as likely to lose patency as patients with thrill (P=.035). No relationship was seen between primary patency and other predictors examined. CONCLUSION: Early fistulography enables identification of underlying areas of stenosis in nonmaturing fistulas, which can be safely and effectively treated with angioplasty. With continued surveillance and repeat interventions, functional patency can be sustained in the majority of fistulas.

Role of ultrasound surveillance of transjugular intrahepatic portosystemic shunts in the covered stent era.

PURPOSE: To assess ultrasound (US) surveillance of expanded polytetrafluoroethylene (ePTFE)-covered stents in transjugular intrahepatic portosystemic shunts (TIPS). MATERIALS AND METHODS: Procedural data, including stent size and portosystemic gradients (PSG) before and after creation of TIPS, were obtained retrospectively in 55 patients (33 men, 22 women). Chart review provided clinical information, including etiology of liver disease, indication for TIPS creation, and Child-Pugh class. Radiology reports provided US venography data and pathology reports confirmed shunt status in transplant recipients. Patients had baseline US examinations 3-7 days after TIPS creation with scheduled follow-up at 1, 3, 6, and 12 months after the procedure. Clinical and radiology reports were compared to evaluate US surveillance of Viatorr stents. RESULTS: One hundred fifty-nine US examinations were performed on 52 patients, for an average 3.1 studies per patient (range, 1-7) over a mean follow-up duration of 173 days (range, 0-1,013 d). Sixty-four US studies (40%) were baseline studies, 88 studies (55%) were routine follow-up studies, and seven (4%) were interval studies. US predicted TIPS abnormalities in 30 of 159 studies (19%); venography followed 15 of 30 abnormal US findings (50%) and clinical examinations complemented 10 of 15 venograms (67%). Venography and US were concordant in eight of 15 paired studies (53%); clinical examinations, when conducted, accurately predicted shunt status in all but one case. US findings changed management in six of 159 studies (4%): five of six (83%) were baseline evaluations and the other one (17%) was a routine follow-up examination. A total of five baseline US examinations (8%) and one surveillance examination (1%) altered patient management. CONCLUSIONS: A single US examination after a TIPS procedure to confirm immediate function may be valuable, but routine US is not effective for long-term surveillance of ePTFE-covered stents.

Asymptomatic central venous stenosis in hemodialysis patients.

PURPOSE: To retrospectively evaluate the natural history of high-grade (>50%) asymptomatic central venous stenosis (CVS) in hemodialysis patients and the outcome of serial treatment of CVS with percutaneous transluminal angioplasty (PTA). MATERIALS AND METHODS: The institutional review board granted exemption for this retrospective study, the need for informed consent was waived, and all data collection was in compliance with HIPAA. Patients with hemodialysis access requiring maintenance procedures between 1998 and 2004 and incidentally found to have ipsilateral (> or =50%) CVS were identified from a departmental database. Thirty-five patients (19 men, 16 women; mean age, 58.7 years) with 38 grafts met inclusion criteria, and 86 venograms were reviewed. CVS was measured by using venograms obtained before and after PTA, if performed. Patients with arm swelling, multiple CVS, indwelling catheters, and stents at the first encounter were excluded. CVS progression was calculated by dividing the change in the degree of stenosis by the time between venographic examinations. Wilcoxon rank sum test was used to evaluate differences in rate of CVS progression between treated and nontreated patients. RESULTS: Mean degree of CVS before intervention was 71% (range, 50%-100%). Sixty-two percent (53 of 86) of lesions had associated collateral vessels; 28% (24 of 86) of CVSs were not treated. Mean degree of stenosis in this group was 72% (range, 30%-100%); mean progression was -0.08 percentage point per day. No untreated CVS progressed to symptoms, stent placement, or additional CVS. Seventy-two percent (62 of 86) of CVSs were treated with PTA. Mean degree of stenosis in this group was 74% (range, 50%-100%) before and 40% (range, 0%-75%) after treatment; mean progression was 0.21 percentage point per day after treatment (P = .03). Six (8%) of 62 treatments were followed by CVS escalation; one patient developed arm swelling, four required stents, and four developed additional CVS. CONCLUSION: PTA of asymptomatic CVS greater than 50% in the setting of hemodialysis access maintenance procedures was associated with more rapid stenosis progression and escalation of lesions, compared with a nontreatment approach.

Single-center experience with the Arrow-Trerotola Percutaneous Thrombectomy Device in the management of thrombosed native dialysis fistulas.

PURPOSE: The present study sought to evaluate the performance of the Arrow-Trerotola Percutaneous Thrombolytic Device (PTD) in the treatment of native fistula thrombosis in a U. S. hemodialysis population. Specifically, the technical success, clinical success, complication rate and type, primary and secondary patency rates, effect of adjunctive thrombolytic therapy, and any variables that affected outcomes of procedures in which this device was used were analyzed. MATERIALS AND METHODS: Forty-two patients with 44 thrombosed native fistulas (17 radiocephalic, 10 brachiocephalic, 10 transposed or superficialized, five graft/fistula hybrids, and two leg fistulas) were treated with 62 mechanical thrombolysis procedures with use of the PTD. All patients had large clot burden. The device type was recorded in 43 procedures: standard (n = 21), over-the-wire (OTW; n = 19), or both (n = 3). No device was used in two cases because of inability to cross the anastomosis. Adjunctive therapies (n = 18) included the use of tissue plasminogen activator (tPA; n = 16) and deployment of the AngioJet device with (n = 1) or without tPA (n = 1). Stents were inserted in four procedures. Outcome variables included technical and clinical success, complications, and primary and secondary patency. Cox proportional-hazards regression and Kaplan-Meier analyses were performed. RESULTS: The technical success rate was 87% (54 of 62) and the clinical success rate was 79% (49 of 62). Percutaneous transluminal angioplasty was performed in all but two procedures. Complications occurred in 13% of procedures (n = 8); three resulted in technical failure. The primary patency rates were 38% at 6 months and 18% at 12 months; secondary patency rates were 74% and 69%, respectively. Outcomes were not affected by adjunctive techniques, fistula type, age of fistula, device type (ie, OTW vs standard), or patient sex. Secondary patency was superior when no residual clot or stenosis was present (P = .003). CONCLUSIONS: The PTD is effective for percutaneous treatment of thrombosed hemodialysis fistulas, with good short- and long-term outcomes in a U.S. population. Within the limitations of a retrospective study with a small sample size, use of an adjunctive thrombolytic agent did not appear to improve results compared with the use of the device alone.

Prospective study of balloon inflation pressures and other technical aspects of hemodialysis access angioplasty.

PURPOSE: Balloon angioplasty is a mainstay in the treatment of failing or thrombosed hemodialysis access grafts and fistulas. A sizable body of outcomes data exists concerning percutaneous transluminal angioplasty (PTA) in hemodialysis access, yet there is a relative paucity of technical information available, especially regarding dilation pressures. The aim of the present study was to compile such information, which can be critical to the choice of devices for PTA and to the design of future clinical trials seeking to improve outcomes in this area. MATERIALS AND METHODS: Technical data were collected prospectively for 102 PTA procedures (66 prophylactic PTA procedures and 36 PTA procedures performed during access thrombectomy). Demographic data concerning the access were collected. Technical data were collected individually for each lesion treated, including lesion location; degree of stenosis (in quartiles); lesion length; PTA balloon brand, size, and length; pressure at which the waist of the balloon was effaced; residual stenosis; and reason for additional balloons or inflations if used. Outcomes data other than residual stenosis were not collected, but the endpoint for all interventions was a thrill in the access. RESULTS: A total of 230 lesions were treated. Two (1%) could not be successfully treated with PTA despite the use of "ultra high" pressure (approximately 40 atm); one was treated successfully with parallel wire technique and the other was revised surgically after the use of a cutting balloon also failed. Overall, 55% of lesions required pressures greater than 15 atm to efface the waist. Excluding initial failures, 20% of lesions in native fistulas and 9% in grafts required very high pressure (>20 atm) to efface the waist (P = .02). High pressure was needed less frequently in PTA procedures performed in the setting of thrombectomy procedures than in prophylactic PTA procedures (P = .0001). Residual stenosis was positively correlated with severity of initial stenosis and negatively correlated with duration of inflation. CONCLUSIONS: Conventional angioplasty balloons are inadequate for the treatment of most hemodialysis access stenoses. High pressures (>15 atm) are commonly needed for PTA in hemodialysis access. Very high pressures (>20 atm) are more frequently needed in native fistulas.

Relationship between chest port catheter tip position and port malfunction after interventional radiologic placement.

PURPOSE: The relationship between catheter tip position of implanted subcutaneous chest ports and subsequent port malfunction was investigated. Tip movement from initial supine position to subsequent erect position was also evaluated. MATERIALS AND METHODS: Patients who underwent imaging-guided internal jugular chest port placement between July 2001 and May 2003 were identified with use of a quality-assurance database. Sixty-two patients were included in the study (22 men and 40 women), with a mean age of 58 years (range, 27-81 years). Catheter tip location on the intraprocedural chest radiograph was determined with use of two methods. First, the distance from the right tracheobronchial angle (TBA) was recorded (TBA distance). Second, tip location was classified into six anatomic regions: 1, internal jugular veins; 2, brachiocephalic veins; 3, superior vena cava (SVC; n = 11); 4, SVC/right atrial junction (n = 22); 5, upper half of right atrium (n = 25); and 6, lower half of right atrium (n = 4). For the duration of follow-up, catheter tip location was documented, as were all episodes of catheter malfunction. RESULTS: Patients with catheter tips initially placed in position 3 had a higher risk of port malfunction (four of 11; 36%) than patients with catheter tips located in position 5 (two of 25; 8%). This difference narrowly fell short of statistical significance (P =.057). When comparing intraprocedural chest radiographs to the first erect chest radiographs, significant upward tip movement was noted. The tips migrated cephalad an average of 20 mm (P =.003) and 1.0 position units (P =.001). DISCUSSION: Catheter tips placed in the SVC tended to have a greater risk of port malfunction compared with those positioned in the right atrium. Chest ports migrated cephalad between the supine and erect positions.