Search

Purpose: To determine whether implementation of an easily accessible electronic database promotes significant reporting of magnetic resonance imaging (MRI) acquisition errors. Additionally, we wanted to see if analysis of the error reports could be used to create a comprehensive checklist to avoid the most common errors., Methods: A new, simple, and efficient electronic database reporting system was written in-house and implemented at our institution. Over the course of 4 months, the use of this database enabled collection and analysis of sufficient data for trend analysis. A simple 4-point checklist for MRI technologist use was developed based on the most commonly reported errors. Reported MRI acquisition error rates were collected and analyzed thereafter., Results: By the first full month of implementation, MRI scan error reporting increased from a previous negligible baseline rate to 3.03%. The comprehensive checklist was based on the 4 most common issues reported. Verification of checklist use showed that adherence to this requirement averaged greater than 94%. Immediately following roll out of the checklist, the percentage of errors reported fell to 1.7% with a continued decline in error reports thereafter. An approximately 60% reduction in errors in the last month of the study was evident as compared to the first month of data collection., Conclusions: The use of an efficient error reporting system and implementation of a checklist based on the most common MRI acquisition errors results in a substantial decrease in the baseline MRI acquisition error rates., (Copyright © 2018 Elsevier Inc. All rights reserved.)

Purpose: To demonstrate the feasibility of reversible vessel embolization with angiographic guidance for delivery of a rapid reverse-thermosensitive polymer to provide hemostasis as an aid for minimally invasive renal surgery in a porcine model., Materials and Methods: After isolation of the left kidney of seven anesthetized pigs (50-70 kg) with a surgical robot, a renal angiogram of both kidneys was obtained. A 5-F angiographic catheter was used to selectively embolize a lower-pole segmental artery of the right and left kidney with a thermosensitive polymer (LeGoo-XL). Distal and proximal embolization of the target vessel was compared. Degree and duration of hemostasis and reversibility was determined. After complete hemostasis was obtained angiographically, a partial robotic lower-pole nephrectomy was performed on the left kidney only., Results: Only proximal embolization provided controllable hemostasis. A 20% polymer concentration in a buffer solution of 40% saline solution and 40% iodine contrast medium by weight injected at room temperature resulted in a reproducible embolus for more than 30 minutes, the time needed to perform a partial nephrectomy. The radiographic appearance of the embolus was used to determine the total amount of polymer needed. Cold saline solution completely dissolved any residual polymer at the end of surgery., Conclusions: Proximal arterial occlusion with a thermosensitive polymer can be rapidly reversed with selective intraarterial infusion of chilled saline solution. Preceding nephron-sparing surgery with transcatheter embolization of the relevant branch of the renal artery with the polymer can facilitate the procedure and ought to be investigated further.

Purpose: Renal vascular clamping with ensuing warm ischemia is typically needed during robotic or laparoscopic partial nephrectomy. We developed a technique for angiographic delivery of the novel intra-arterial reverse thermoplastic polymer LeGoo-XL that allows temporary selective vascular occlusion with normal perfusion of the remaining kidney., Materials and Methods: Eight pigs underwent a total of 16 selective angiographic occlusions of the lower pole segmental artery using gel polymer. The technical feasibility of 2 hemostatic techniques, perfusion hemostasis and local plug formation, was assessed in 4 pigs each. Selective ischemia time was recorded and the vascular occlusion site was noted radiographically and laparoscopically. The feasibility of reversing the polymer from solid back to liquid state to allow reperfusion was determined. Pathological analysis of the kidney was completed in these acute model pigs. In the last 2 cases lower pole robotic partial nephrectomy was done using the da Vinci surgical system., Results: Selective lower pole ischemia was achieved in all 8 cases. Perfusion hemostasis yielded an inconsistent duration of occlusion (zero to greater than 60 minutes). Vascular occlusion time using local plug formation was more reliable (17 to 30 minutes) with consistent ability to reverse the plug to liquid state by cold saline flush. Two lower pole robotic partial nephrectomies were completed with minimal blood loss., Conclusions: We developed a reliable technique of angiographic delivery of gel polymer for temporary vascular occlusion of selective renal artery branches using local plug formation. Ongoing studies are under way to assess technique consistency and the long-term effects of the polymer.

Purpose: The clinical literature describing the use of alteplase in the treatment of peripheral arterial occlusive (PAO) disease is reviewed., Materials and Methods: The literature database was acquired by a MEDLINE search using the Boolean keyword string: tissue plasminogen activator and/or rt-PA and peripheral not animal. A review was performed to identify the dose range of alteplase, technique of infusion, use of anticoagulation, clinical success rates, and risk of complications., Results: Forty-six clinical studies were identified. There are few prospective, randomized clinical trials and a lack of standardized protocols and endpoints. Use of catheter-directed infusions of recombinant tissue plasminogen activator (rt-PA) may be beneficial versus surgery in the initial management of acute limb ischemia (< 14 days) and in reducing the magnitude of subsequent surgical or percutaneous revascularization. For patients with chronic limb ischemia (> 14 days), irreversible acute limb ischemia, or advanced diabetic arteriopathy, catheter-directed infusion of rt-PA or other plasminogen activators may be unsuitable. The risk of adverse bleeding appears related to the overall dose and duration of infusion. These risks appear similar to those of urokinase. The role of heparin in increasing adverse bleeding during rt-PA therapy is unclear., Conclusions: There is no generally accepted dose or technique for administering catheter-directed thrombolysis using alteplase; however, several studies have demonstrated its clinical safety and efficacy. Formal studies will be required to determine the optimal dose, technique of infusion, the role of anticoagulation, and complication rates when alteplase is used for PAO disease.

Purpose: Significant disease or occlusion of the common femoral artery may preclude percutaneous therapy for aorto-iliac occlusive disease. In addition, aorto-iliac angioplasty may not reverse the ischemic symptoms when common femoral artery disease exists. The authors describe the feasibility of endoluminal stent-grafts to treat multilevel aortoiliofemoral occlusive disease., Materials and Methods: The authors placed 18 stent-grafts for aorto-iliac occlusive disease in 17 patients with limb-threatening ischemia and significant common femoral artery disease. These procedures were performed as a joint effort between vascular surgery and interventional radiology staff in the operating room. The common femoral artery was occluded in 10 or severely diseased in eight, necessitating endoluminal bypass to the superficial femoral or popliteal artery (n = 7) or to the deep femoral artery (n = 7), or necessitating patch angioplasty of the common femoral artery (n = 4). Stent-grafts were fabricated from 6-mm polytetrafluoroethylene and 29-mm Palmaz stents., Results: All 18 grafts were placed successfully. Follow-up ranged from 3 to 38 months (mean, 21 months). Seven patients died of myocardial infarction; two grafts occluded and one required angioplasty during follow-up, resulting in a primary patency rate of 81% at 2 years., Conclusion: Endoluminal stent-graft placement is a useful method of treatment for advanced atherosclerotic aorto-iliac disease, particularly in the presence of common femoral artery disease. This approach avoids an extra-anatomic bypass or a major transabdominal aortic bypass procedure. Longer follow-up with a larger series is needed to ensure the safety and late graft patency comparable to the traditional aortofemoral and iliofemoral bypass grafts.