Javier E. Anaya-Ayala

Efficacy of covered stent placement for central venous occlusive disease in hemodialysis patients

OBJECTIVES Covered stents have been proposed as an endovascular option for recalcitrant cases of hemodialysis-related central venous occlusive disease (CVOD). This study evaluated the efficacy and durability of covered stents in treating CVOD to preserve a functional dialysis access circuit. METHODS A retrospective review was performed of all patients with clinically significant CVOD who were treated by placement of covered stents from April 2007 to September 2010. Demographics, lesion locations and anatomic characteristics, stent graft, and access patency rates were determined. Complications, reinterventions, and factors influencing their outcomes were examined. RESULTS In 25 patients (56% men; mean age, 57 ± 29 years) with CVOD, covered stents were used in 20 to treat symptomatic venous hypertension or in 5 at the time of access creation to enable functionality. The target lesion was accessed via the dialysis access site or the common femoral vein. The Viabahn endoprosthesis (W. L. Gore and Associates, Flagstaff, Ariz) was used in 24 patients (average size and length, 11 mm × 5 cm) and a 13-mm × 5-cm Fluency covered stent (Bard Peripheral Vascular, Tempe, Ariz) was implanted in 1 patient. Technical success was 100%, and resolution of arm edema occurred after covered stent deployment in symptomatic patients. Two postprocedural cases (8%) of thrombosis occurred, one within 30 days and another at 3 months. Both required percutaneous thrombectomy and percutaneous transluminal angioplasty (PTA). Three additional patients (12%) required PTA due to restenosis in one of the ends of the device. Covered stent primary patency (PP), assisted primary patency (APP), and secondary patency (SP) were 56%, 86%, and 100% at 12 months, respectively. Access patency rates at 12 months were 29%, 85%, and 94% for PP, APP, and SP, respectively, in patients that received a covered stent for access salvage; patency rates were 74%, 85%, and 94% for PP, APP, and SP, respectively, in patients in whom the access was created after the venous outflow restoration. CONCLUSIONS Placement of covered stents for hemodialysis-related CVOD is safe, effective in relieving symptoms, and enabled functionality of new dialysis access circuits. Further prospective and randomized studies are necessary to determine whether covered stents provide superior long-term results to those achieved with PTA and bare metal stents.

Surgical management of hemodialysis-related central venous occlusive disease: A treatment algorithm

BACKGROUND Creation and preservation of dialysis access in patients with central venous occlusive disease (CVOD) is a complex problem. The surgical approach and decision-making process remains poorly defined. We evaluated our experience in the surgical management of hemodialysis-related CVOD. Surgical technique, demographics, complications, reinterventions, access function rates, and factors influencing morbidity and mortality were examined. METHODS From January 2006 to May 2010, we performed a total of 1,703 dialysis access-related procedures, 1,021 arteriovenous fistulas (AVFs), 335 arteriovenous grafts (AVGs), and 314 access revisions including endovascular salvage procedures. Seventeen patients (10 women [58%] with a mean age of 44 ± 27 years) with CVOD who were not suitable for peritoneal dialysis or kidney transplant underwent 20 complex vascular access procedures. The indications were need for access creation in 14 cases (70%) and preservation in the remaining 6 (30%). Polytetrafluoroethylene (PTFE) was used for all surgical bypass grafts (BPG). All patients had previously undergone multiple access surgeries and had failed percutaneous interventions for CVOD. RESULTS The surgical planning centered on finding venous outflow for an arteriovenous (AV) access; central venous reconstructions were necessary in 10 (50%) cases (seven [35%] in the thoracic central venous system and three [15%] in infradiaphragmatic vessels) and extracavitary venous BPG in two (10%) cases. Non-venous access options included axillary arterial-arterial chest wall BPG in five (25%) cases and brachial artery to right atrium BPG in three (15%). Technical success was achieved in all cases (100%). Mean follow-up was 14.1 months, both BPG and AV access patency rates were 66% at 6 months and overall average AV access function time was 9.2 months. Of these, 85% of patients were discharged home and following 19 (95%) cases they returned or improved their baseline functional status. One death occurred from multiorgan failure during the 30-day postoperative period. Four additional patients died within 3 years of the procedure secondary to nonsurgical-related comorbidities. CONCLUSION The need for complex vascular accesses will continue as the number of patients with end-stage renal disease increases. CVOD is an access surgical challenge and with this article we propose a decision-making algorithm.

Transcranial Doppler findings during thoracic endovascular aortic repair

OBJECTIVE Thoracic endograft placement has become an acceptable treatment alternative to open repair of the thoracic aorta. Cerebral embolization when manipulating the aortic arch during cardiac catheterization is well described, but the influence of thoracic endovascular aortic repair (TEVAR) on this event remains poorly studied. Our aim was to quantify the number of microembolic signals (MES) detected by transcranial Doppler (TCD) during different stages of TEVAR and correlate them with landing zones, subclavian revascularization, and postoperative morbidity and mortality. METHODS TCD was used to monitor 20 patients during TEVAR for the treatment of thoracic aortic aneurysms (TAAs) in 17 (85%) patients, followed by three (15%) with chronic type B aortic dissection and one (5%) Crawford type I thoracoabdominal aortic aneurysm (TAAA). Imaging and medical parameters were entered into a combined database. TCD signals were recorded digitally for the entire case. MES, velocities, and pulsatility index values were entered into a combined database. RESULTS The total number of MES calculated for the diagnostic phase before TEVAR placement and during the treatment phase for all cases combined was 1081 and 1141, respectively. The highest MES counts were generated by the pigtail catheter placement during the diagnostic phase and by device placement during the treatment phase. Embolic count to right/left sides was equal overall. In the diagnostic phase, an average of nine MES were seen right/left, whereas during the treatment phase, 45 and 43 MES were seen, respectively, for right/left. A significant association was found between the total number of MES and postoperative stroke, transient ischemic attack (P = .0055), and death (P = .0053). CONCLUSIONS TCD can detect microemboli during TEVAR and is able to identify the procedural aspects most associated with cerebral microemboli.

Impact of metabolic syndrome on the outcomes of superficial femoral artery interventions

BACKGROUND Metabolic syndrome (MetSyn) is an epidemic in the United States and is associated with early onset of atherosclerosis, increased thrombotic events, and increased complications after cardiovascular intervention. MetSyn is found in ∼50% of patients with peripheral vascular disease. However, its impact on peripheral interventions is unknown. The aim of this study is to determine the outcomes of superficial femoral artery (SFA) interventions in patients with and without MetSyn. METHODS A database of patients undergoing endovascular treatment of SFA disease between 1999 and 2009 was retrospectively queried. MetSyn was defined as the presence of ≥3 of the following criteria: blood pressure ≥130 mm Hg/≥85 mm Hg; triglycerides ≥150 mg/dL; high-density lipoprotein ≤50 mg/dL for women and ≤40 mg/dL for men; fasting blood glucose ≥110 mg/dL; or body mass index ≥30 kg/m(2). Kaplan-Meier survival analyses were performed to assess time-dependent outcomes. Factor analyses were performed using a Cox proportional hazard model for time-dependent variables. RESULTS A total of 1018 limbs in 738 patients (64% male, average age 67 years) underwent endovascular treatment for symptomatic SFA disease with 45% of patients meeting the criteria for MetSyn. MetSyn patients were more likely to be female (P = .001), to present with critical ischemia (rest pain/tissue loss: 55% MetSyn vs 45% non-MetSyn; P = .001), have poorer ambulatory status (P = .001), and have more advanced SFA lesions (TransAtlantic Inter-Society Consensus II C/D: 51% vs 11%; P = .001) and worse tibial runoff (P = .001). MetSyn patients required more complex interventions (P = .0001). There was no difference in mortality and major adverse cardiac events, but systemic complications (4% vs 1%; P = .001) and major adverse limb events (12% vs 7%; P = .0009) were significantly higher in the MetSyn group. Immediate postprocedural hemodynamic improvement, resolved or improved symptoms, and restoration of impaired ambulation were equivalent in both groups. Early failure (<6 months) was more common in those with MetSyn. At 5 years, primary, assisted primary, and secondary patencies were not affected by the presence of MetSyn. The presence of MetSyn was associated with a decrease in clinical efficacy, decreased freedom from recurrent symptoms, and decreased freedom from major amputation at 5 years. CONCLUSIONS MetSyn is present in nearly half of the patients presenting with SFA disease. These patients present with more advanced disease and have poorer symptomatic and functional outcomes compared with those patients without MetSyn.

Robot-Assisted Stenting of a High-Grade Anastomotic Pulmonary Artery Stenosis Following Single Lung Transplantation

Purpose: To report robot-assisted stenting of a stenosis at the pulmonary artery anastomosis following lung transplantation, a rare complication that conveys poor prognosis even after surgical correction. Technique: The technique is illustrated in a 72-year-old man with end-stage lung disease who received a left single lung transplant. On postoperative day 54, he was evaluated for recurrent dyspnea on exertion that was due to a severe stenosis at the site of the pulmonary artery anastomosis. Balloon angioplasty was performed, and a 10-mm stent was deployed, with marked clinical improvement. Fourteen months later, he presented with recurrent symptoms due to in-stent restenosis. Multiple attempts at catheterization and balloon angioplasty of the stent failed. Due to the technical difficulty involved in maneuvering the balloon while maintaining stability, it was decided to repeat the angioplasty with the assistance of a Hansen Sensei remote robotic navigation system. The robotic arm markedly enhanced stability and facilitated successful navigation of the stented site. A 16-mm-diameter Wallstent was placed through the previously placed balloon-expandable stent and postdilated. Conclusion: A remote robotic catheter navigation system was able to assist stenting of an anastomotic pulmonary artery stenosis following failure of conventional interventional techniques.

Management of dialysis access-associated "steal" syndrome with DRIL procedure: Challenges and clinical outcomes

Purpose The Distal Revascularization Interval-Ligation (DRIL) procedure has demonstrated efficacy in the management of Dialysis Access-associated Steal Syndrome (DASS); however, this has not been widely used because of concerns about complexity, risk of ligating a native artery, and lack of long-term outcomes. Methods Retrospective review of all patients with DASS who underwent DRIL procedure from March 2005 to August 2011. Indications, clinical considerations, bypass grafts, and patency rates were determined; complications, reinterventions, and factors influencing their outcomes were studied. Results 33 patients, (70% women, mean age of 56 ± 13) with DASS underwent a DRIL. Indications were ischemic pain alone in 12 (36%) patients, loss of neurologic function in 7 (21%), both ischemic pain and loss of neurologic function in 4 (12%) tissue loss in 7 (21%), pain during hemodialysis in one (3%), and “prophylactic” DRIL during a Femoral Vein transposition (FVt) fistula in two (6%). Technical success was 100%; Ischemic symptoms fully resolved by DRIL in 24 of the 31 symptomatic patients (77%) and during the follow up period DASS did not develop in the subjects we judged at high risk and underwent DRIL during FVt. One serious complication occurred because of early bypass thrombosis causing worsening hand gangrene requiring transmetacarpal amputation. The primary, assisted-primary, and secondary patency rates of the arterial bypass at 12 months were 65%, 75%, and 95% respectively. AV access primary, assisted-primary, and secondary patency were 29%, 85%, and 94% at 12 months. Conclusions DRIL procedure is effective at relieving symptoms in carefully selected patients, but does have potential complications such as bypass failure and worsened ischemia. DASS remains a complex clinical entity in that it is not fully understood, and deserves further study.

Comparison of Outcomes of One-Stage Basilic Vein Transpositions and Two-Stage Basilic Vein Transpositions

BACKGROUND Basilic vein transpositions (BVTs) provide autologous hemodialysis access in the upper extremity. We report and compare our experience using the two techniques that are commonly performed to create BVTs: the one-stage and the two-stage technique. METHODS A retrospective review was performed on patients who underwent BVT from June 2006 to June 2010 from a database of all patients undergoing dialysis access procedures. One hundred six patients, mean age of 54 years (41% male), who received upper-arm basilic vein-only transposition were identified and were stratified based on one-stage and two-stage BVTs. Anatomic outcomes and functionality were determined and compared between stages. RESULTS Seventy-seven patients underwent two-stage BVT, and 29 underwent one-stage BVT. Fifty-one percent and 79% of the two-stage group and the one-stage group, respectively, had had a previous failed ipsilateral permanent access. Catheter dialysis at time of surgery was 14% in one-stage BVT and 43% in two-stage BVT. Immediate technical success was obtained in all cases. The rate of primary failure was 21% in the one-stage group and 18% in the two-stage group. Reintervention rates for the one-stage group and the two-stage group were 62% and 66%, respectively. Primary patency for the one-stage group and the two-stage group at 1 year was 82% and 67%, at 2 years was 81% and 27%, and at 3 years was 51% and 18%, respectively. Secondary patency for the one-stage group and the two-stage group at 1 year was 91% and 81%, at 2 years was 80% and 61%, and at 3 years was 58% and 45%, respectively. Thirty-day mortality was 0% in both groups, and all-cause morbidity was 12% in both groups (counting all stages). CONCLUSION One-stage BVTs have a similar number of initial failures and secondary interventions as two-stage BVTs. One-stage BVTs achieved better primary and cumulative patencies. There appears to be no advantage to a two-stage BVT in equally matched patients.

Successful Emergency Endovascular Treatment for Superior Vena Cava Injury

Superior vena cava (SVC) hemorrhage due to iatrogenic injury is an infrequent but important event. We report the case of a 56-year-old woman with a history of right pneumonectomy for lung cancer with iatrogenic SVC injury and hemorrhage. After unsuccessful attempts at suture repair of the defect, an endovascular approach using a stent graft succeeded in controlling hemorrhage while maintaining vessel patency. To our knowledge, this is the third report of SVC hemorrhage control using this technique, and it supports the experience of other authors that endovascular stenting is an effective means of treating emergent venous hemorrhage.

Preliminary findings in quantification of changes in septal motion during follow-up of type B aortic dissections

OBJECTIVE To quantify longitudinal changes in intra-arterial septum (IS) motion with two-dimensional (2D) phase-contrast magnetic resonance imaging (2D pcMRI) in type B aortic dissections (AD) to improve the understanding of AD and its midterm development. METHODS From a database of 42 patients who underwent a dynamic magnetic resonance imaging (MRI) examination at the Acute Aortic Treatment Center of The Methodist DeBakey Heart & Vascular Center, 2D pcMRI image data was available from 10 patients with type B AD for both short-term (mean, 6.6 days; range, 1-10 days; n = 7) and midterm follow-up (mean, 155 days; range, 60-324; n = 5). IS motion was quantified as motion of IS boundary points averaged over the cardiac cycle. Relative change in IS motion was expressed as percent change compared with initial presentation. Maximum IS extension (true lumen [TL] expansion) and contraction (TL compression), IS fraction in phase with aortic flow and correlation of IS motion with aortic flow (IS compliance) were quantified. RESULTS IS motion at initial presentation was 0.68 ± 0.2 mm and was reduced at short-term (0.48 ± 0.3 mm; P = .07) and midterm (0.5 ± 0.2 mm; P = .1) follow-up. Trend in relative change of IS motion was variable during short-term follow-up: reduced in three subjects (-75% ± 6%) and elevated in four subjects (48% ± 23%). During midterm follow-up, relative change in IS motion was reduced in four subjects (28% ± 19%) and slightly elevated in one (6.2%). IS contraction decreased with follow-up while IS extension slightly increased. Fraction of IS moving in phase with aortic flow increased but IS compliance decreased, suggesting increasing IS stiffness. CONCLUSIONS Reduction of IS motion in AD is seen with short-term and midterm follow-up. Intersubject variability of this trend is high at short-term follow-up but low at midterm follow-up. Detailed analysis of IS motion parameters indicate reduction of IS contraction and IS compliance with time. This has potential implications for endovascular management of type B aortic dissections, as expansion of aortic stent grafts can be limited by a stiff IS.

Impact of tear location on hemodynamics in a type B aortic dissection investigated with computational fluid dynamics

Stanford type B aortic dissections (TB-AD), which split the descending aorta in a true and false lumen, have better in-hospital survival than type A dissections affecting the ascending aorta. However, short-term and long-term prognosis for the individual patient remains challenging, with one in four patients not surviving after 3 years.