Z. Irani

The Impact of Transvenous Cardiac Devices on Vascular Access Patency in Hemodialysis Patients

Creating a vascular access in the presence of a cardiovascular implantable electronic device (CIED) in a patient with or approaching end‐stage renal disease can be challenging. In this study, we aimed to evaluate the impact of a CIED on the outcomes of vascular access creation in hemodialysis patients and determine their effects on vascular access patency. This is a single‐center retrospective review of hemodialysis patients who underwent vascular access creation after CIED placement. Outcomes of vascular access creation and need for endovascular interventions were compared between patients with vascular access created ipsilateral and contralateral to the site of CIED. Comparing patients with arteriovenous (AV) access created ipsilateral to CIED placement (n = 19) versus the contralateral side (n = 17), the primary failure rate was 78.9% versus 35.3% (p = 0.02). For AV accesses that were matured, the median primary patency durations for AV accesses created ipsilateral to the CIED was 11.2 months compared to 7.8 months for AV accesses created contralateral to the CIED (p = 1.00). AV accesses created ipsilateral to a CIED have a higher primary failure rate compared with the contralateral arm and should be avoided as much as possible.

Endovascular removal of a permanent "TrapEase" inferior vena cava filter.

Inferior vena cava (IVC) filter placement has seen a rising trend over the past decade. Although effective in the prevention of future pulmonary emboli, filters are associated with several long-term complications including deep venous thrombosis, filter migration, filter fracture, and caval thrombosis. The IVC filters have evolved over the years to minimize these unwarranted sequelae. We describe a technique to remove a permanent IVC filter in a patient who no longer required mechanical protection.

Catheter-Directed Intraarterial Thrombolysis as Part of a Multidisciplinary Management Protocol of Frostbite Injury

PURPOSE To evaluate intraarterial catheter-directed thrombolysis for prediction and prevention of delayed surgical amputation as part of multidisciplinary management of frostbite injury. MATERIALS AND METHODS A retrospective review was performed of 13 patients (11 men, 2 women; median age, 33.4 y; range, 8-62 y) at risk of tissue loss secondary to frostbite injury and treated with catheter-directed tissue plasminogen activator (t-PA) thrombolysis. Amputation data were assessed on follow-up (mean, 23 mo; range, 9-83 mo). Angiographic findings were classified into complete, partial, and no angiographic response and assessed for association with follow-up amputation rates. Correlation between amputation outcome and duration of cold exposure (mean, 23 h; range, 5-96 h), time between exposure and rewarming therapy (mean, 25.5 h; range, 7-95 h), and time between exposure and t-PA thrombolysis (mean, 32 h; range, 12-96 h) was assessed. Complications were recorded. RESULTS Of 127 digits at risk on baseline angiography that were treated with catheter-directed thrombolysis, complete recovery was seen in 106 (83.4%). Total mean t-PA dose per extremity was 27.5 mg (range, 12-48 mg) over a mean period of 34 hours (range, 12-72 h). Patients with complete angiographic response (8 patients; 79.5% of digits) did not require amputations; 4 of 5 patients (80%) with partial angiographic response (20.5% of digits) underwent amputation (P = .007). There was no significant correlation between amputation rates and duration of cold exposure (P = .9), time to rewarming therapy (P = .88), and time to thrombolysis (P = .56). Femoral access site bleeding in 2 patients was managed conservatively. One patient underwent surgical exploration for brachial artery hematoma. CONCLUSIONS Intraarterial catheter-directed thrombolysis should be included in initial management of frostbite injury, as it may prevent delayed amputations. The degree of angiographic response to thrombolysis can potentially predict amputation outcomes.

Aspiration thrombectomy using the penumbra catheter.

Editor: Thromboembolic diseases are among the most prevalent medical problems today and cause stroke, myocardial ischemia, acute limb ischemia, and pulmonary embolism. Various treatment modalities exist, ranging from medical therapy to endovascular techniques. In the management of a thromboembolic condition causing a threatened limb, common options for treatment include surgical thromboembolectomy, percutaneous thrombectomy, and/or thrombolysis. In recent decades, many mechanical thromboembolectomy devices have become commercially available and have proven to be useful in the treatment of acute thrombi. These devices are often limited in efficacy when treating a chronic, organized thrombus. We recently encountered two cases in which an aspiration thrombectomy device (Penumbra, Alameda, California), which is typically used in the treatment of acute stroke, was used to aspirate chronic thrombi in a patient with a cold hand and in a patient with a chronically thrombosed common iliac vein stent. A 59-year-old man with a 20-year history of poorly controlled diabetes and hypertension presented to the emergency department with left hand pain, numbness, and tingling in the dorsal and palmar surfaces of the fingers. On examination, the left hand was cold, with a weak radial pulse and a delayed capillary refill in the fingers. There was limited range of motion, particularly in the third and fourth digits, during active and passive movement. The forearm compartments were soft with no tenderness. A sensory examination had normal findings, and a Spurling test was negative. Doppler ultrasonography and left upper extremity arteriography demonstrated a focal occlusion of the radial artery at the level of the wrist and severely atherosclerotic ulnar

Stenoses in the surgically manipulated segment have better angioplasty response compared to the surgically naive segment in fistulas

Purpose Balloon angioplasty is the standard treatment for dysfunctional hemodialysis fistulas, but angioplasty response of stenotic lesions located in different segments of the dialysis circuit has not been explicitly evaluated. The purpose of this study is to describe the distribution of stenotic lesions in the most common types of arteriovenous fistulas and to investigate the response to balloon angioplasty of stenotic lesions located in various segments of the fistula circuit. Materials and Methods This single-center, retrospective study was approved by the Institutional Review Board. A total of 263 fistulograms performed between January, 2014 and June, 2015 were reviewed. Stenotic lesion response to angioplasty was analyzed based on lesion location using a Kaplan-Meier analysis. Results Juxta-anastomotic stenoses (48%) were the most common lesions in radiocephalic fistulas, while the cephalic arch (30%) and venous outflow tract (24%) were the most common locations of stenotic lesions in brachiocephalic fistulas and basilic vein transposition fistulas, respectively. Primary patency after balloon angioplasty was significantly higher in lesions located in the venous segments manipulated during surgeries compared to the lesions located in the surgically naive zone (p = 0.001). The 6-month and 12-month primary patency of lesions post-angioplasty in the surgical zone were 76% and 71% compared to 58% and 43% in the surgically naive segments. Conclusions The distribution of stenotic lesions differs among each type of fistula. The primary patency of balloon angioplasty of stenotic lesions located in the surgically manipulated venous segment was significantly better than lesions located in the rest of the fistula circuit.

Catheter‐directed Thrombolysis in Acute Superior Vena Cava Syndrome Caused by Central Venous Catheters

Indwelling central venous catheters have been reported to increase the risk of superior venous cava (SVC) syndrome. This case report describes the development of acute SVC syndrome in a 28‐year‐old woman with end‐stage renal disease implanted with a left‐side hemodialysis reliable outflow graft and a right‐side double lumen hemodialysis catheter via internal jugular veins. Her symptoms were not alleviated after catheter removal and systemic anticoagulation therapy. She was eventually treated with catheter‐directed thrombolysis and a predischarge computer tomographic venogram on postthrombolytic procedure day 7 showed patent central veins and patient remained asymptomatic. This case demonstrates that catheter‐directed thrombolysis can be safely employed to treat refractory catheter‐induced acute SVC syndrome in end‐stage renal disease patients.

Parapedicular vertebral augmentation with polymethylmetacrylate for pedicle screw loosening

A 71-year-old man who had a L1/S1 posterior fusion revision surgery complained of increasing back pain 5 weeks after the open surgical procedure. The pain was initially estimated at 9/10 on the visual analog scale (VAS) and thought to be related to a right-sided L2 screw loosening. A right parapedicular vertebroplasty was performed and polymethylmethacrylate cement was instilled around the right pedicle screw, filling the anterior two-thirds of the vertebral body. On postvertebroplasty day 1, the patient had significant improvement in his low back pain. The pain further decreased at 1 and 3 months after the intervention (2/10 on the VAS). Vertebroplasty is a minimally invasive, accessible, effective, and long lasting treatment for compression fractures. We believe that this technique could also be indicated to treat pain related to low grade screw loosening in properly selected patients.

Incrementally Expandable Transjugular Intrahepatic Portosystemic Shunts: Single-Center Experience

OBJECTIVE The purpose of this study is to investigate the long-term safety and efficacy of a small-diameter expandable transjugular intrahepatic portosystemic shunt (TIPS) in the management of portal hypertension. MATERIALS AND METHODS This single-center retrospective study included 28 patients (12 women and 16 men; mean age, 56.9 years) who underwent small-diameter expandable TIPS creation between 2008 and 2010 for refractory ascites (n = 15; mean [± SD] model for end-stage liver disease [MELD] score, 15.5 ± 5.3) or gastrointestinal variceal bleeding (n = 13; mean MELD score, 15.2 ± 8.4). An expandable TIPS was created by deploying a covered stent inside a balloon expandable stent. For patients with recurrent symptoms, TIPS adjustment was made by balloon expandable stent balloon dilation. The TIPS diameter was defined as the diameter of the final angioplasty balloon. TIPS patency and efficacy and the rate of post-TIPS hepatic encephalopathy were evaluated. RESULTS The median diameter of the initial TIPS was 8 mm in the group with variceal bleeding compared with 6 mm in the group with ascites (p = 0.003). The primary patency rate at 1 and 5 years was 90.8% and 73.3%, respectively. Eighty percent of patients with ascites required no or less-frequent large-volume paracentesis. The clinical success rate for patients with acute variceal bleeding was 92.3%. Six patients with ascites (initial TIPS diameter, 6 mm) and two patients with variceal bleeding (initial diameter, 6 mm and 8 mm) required subsequent TIPS adjustment. Of the 22 patients with no prior history of enecphalophy, seven patients (31.8%) experienced new hepatic encephalopathy within 90 days. CONCLUSION A small-diameter expandable TIPS is technically feasible and safe, with efficacy falling within the range of that of conventional TIPS. This technique offers the possibility of individualizing the degree of portal decompression.

Interrupting Rivaling Access-flow with Nonsurgical Image-guided ligation: the “IRANI” Procedure

The presence of collateral veins is one of the most common causes of fistula failure to mature. The traditional approach to eliminate collateral vessel flow is coil embolization under fluoroscopy or surgical cut down and branch vessel ligation. However, both approaches are expensive and time consuming. Here, we described an image‐guided nonsurgical method to ligate collateral veins. The collateral veins were ligated using Hawkins‐Akins needle under ultrasound guidance. The average time for one ligation procedure was 17 minutes. There was a significant increase of blood flow in the venous outflow postligation procedure. Four weeks postprocedure ultrasound demonstrated occlusion of the target vessels. This procedure was well tolerated without major complications. In summary, the novel procedure described here offers an image‐guided nonsurgical approach for collateral vein occlusion.

Novel Lead-Free Drape Applied to the X-Ray Detector Protects against Scatter Radiation in the Angiography Suite

PURPOSE To evaluate a sterile, disposable lead-free drape for reducing scatter radiation exposure during fluoroscopy-guided procedures. MATERIALS AND METHODS Computer-aided design software was used to model a procedure room with a thoracic anthropomorphic phantom on the angiography table. Using this model, measurements of scatter radiation were made from the phantom before and after the application of the drape using a collimated and full field of view in low-output conditions (70 kVp, 48 mA) and high-output conditions (125 kVp, 156 mA). Transmission of x-rays through the drape and entrance exposure rates were also measured. Statistical significance was measured using a Student t test. RESULTS Scatter radiation was attenuated throughout the procedure room when the drape was applied. The highest level of scatter radiation was detected in the expected position of the operator, adjacent to the phantom. Radioprotection by the drape was the greatest in this position: 71.5% attenuation at waist level and 89% at neck level (P < .0001). The use of the drape did not result in an increase of backscatter radiation to the phantom. CONCLUSIONS The use of this drape significantly reduces scatter radiation in the procedure room; this effect is maximal in close proximity to the phantom.