Management of Central Venous Stenosis and Occlusion in Dialysis Patients.

Central venous occlusions (CVOs) of the major intrathoracic veins (jugular, subclavian, brachiocephalic, superior vena cava) can cause debilitating symptoms, negatively impact arteriovenous fistula/graft function, or limit potential access creation options in end-stage kidney disease (ESKD) utilizing hemodialysis (HD). This review summarizes the incidence, pathophysiology, indications/contraindications, and management options of CVOs in the ESKD on HD population and concludes with considerations and examples when planning endovascular central recanalization procedures, which have risen as the first-line management when appropriate.

HeRO Graft: Indications, Technique, Outcomes, and Secondary Intervention.

The Hemodialysis Reliable Outflow (HeRO) graft is a nontraditional, surgical, and endovascularly placed access that offers options in failing arteriovenous fistula/arteriovenous graft or catheter-dependent patients. The HeRO graft provides a unique option and is specifically referred to in the 2019 Kidney Disease Outcomes Quality Initiative (KDOQI) vascular access update. The interventional radiologist has a role and opportunity to work collaboratively with surgeons in assisting with (1) the identification, selection, preparation for, and placement of HeRO grafts and (2) providing post-placement maintenance to ensure long-term patency.

Conception rates after fluoroscopy-guided fallopian tubal cannulation: an alternative to in vitro fertilization for patients with tubal occlusion.

OBJECTIVE: Previous studies show good technical success rates for fallopian tube recanalization. Scarce literature exists regarding advance techniques currently used by interventional radiologists during fallopian tube recanalization procedures. This study investigates the level of intervention and tubal patency and its association with technical success and associated pregnancy outcomes. METHODS: We retrospectively evaluated fallopian tube recanalization procedures performed at a single center in a 24-year period. A total of 160 couples undergoing a basic infertility evaluation were included. Hysterosalpingography with high pressure contrast injection followed by selective contrast, guidewire catheterization at the tubal ostium, and/or microcatheter/microwire recanalization were performed. Comparisons of the tubal fertilization rate by relevant characteristics were tested for statistical significance with t tests for continuous data or with Pearson chi-square tests for categorical data. RESULTS: Technical success rate was 94% (319 of 341 tubes). High pressure contrast injection alone (184 of 341, 54%), selective catheterization (40%), and microcatheter/microwire (6%) interventions yielded technical success rates of 98%, 90%, and 73%, respectively. The overall rate of conception was 35% (17 of 48). CONCLUSION: Current techniques of fallopian tube recanalization offer a desirable and safe option with high technical success for patients seeking treatment for infertility due to proximal fallopian tube obstruction.

Laser Recanalization of a Chronically Occluded Transjugular Intrahepatic Portosystemic Shunt (TIPS).

Transjugular intrahepatic portosystemic shunt (TIPS) dysfunction is conventionally managed with balloon angioplasty, stent extension, and sharp recanalization when necessary. We describe percutaneous transjugular recanalization and neointimal excision of a chronically occluded 17-year-old TIPS using excimer laser after conventional techniques were unsuccessful. Patient clinical improvement and shunt patency were documented three weeks post-intervention.

Transportal Radioembolization as Salvage Hepatocellular Carcinoma Therapy to Maintain Liver Transplant Candidacy.

A 53-year-old woman with chronic hepatitis B and multifocal hepatocellular carcinoma was unable to receive transarterial radioembolization and had disease progression despite multiple chemoembolizations and systemic chemotherapy. Transportal radioembolization (TPRE) to maintain transplant candidacy was performed. Two lesions (1.7 cm, 1.4 cm) were treated with a single session of TPRE. Imaging performed at 4 months after TPRE demonstrated complete response in one lesion and stable disease in the other. This case illustrates TPRE as a salvage therapy for hepatocellular carcinoma in select patients.

Improving Performance During Image-Guided Procedures.

OBJECTIVE: Image-guided procedures have become a mainstay of modern health care. This article reviews how human operators process imaging data and use it to plan procedures and make intraprocedural decisions. METHODS: A series of models from human factors research, communication theory, and organizational learning were applied to the human-machine interface that occupies the center stage during image-guided procedures. RESULTS: Together, these models suggest several opportunities for improving performance as follows: 1. Performance will depend not only on the operator's skill but also on the knowledge embedded in the imaging technology, available tools, and existing protocols. 2. Voluntary movements consist of planning and execution phases. Performance subscores should be developed that assess quality and efficiency during each phase. For procedures involving ionizing radiation (fluoroscopy and computed tomography), radiation metrics can be used to assess performance. 3. At a basic level, these procedures consist of advancing a tool to a specific location within a patient and using the tool. Paradigms from mapping and navigation should be applied to image-guided procedures. 4. Recording the content of the imaging system allows one to reconstruct the stimulus/response cycles that occur during image-guided procedures. CONCLUSIONS: When compared with traditional "open" procedures, the technology used during image-guided procedures places an imaging system and long thin tools between the operator and the patient. Taking a step back and reexamining how information flows through an imaging system and how actions are conveyed through human-machine interfaces suggest that much can be learned from studying system failures. In the same way that flight data recorders revolutionized accident investigations in aviation, much could be learned from recording video data during image-guided procedures.

Objective assessment of operator performance during ultrasound-guided procedures.

PURPOSE: Simulation permits objective assessment of operator performance in a controlled and safe environment. Image-guided procedures often require accurate needle placement, and we designed a system to monitor how ultrasound guidance is used to monitor needle advancement toward a target. The results were correlated with other estimates of operator skill. METHODS: The simulator consisted of a tissue phantom, ultrasound unit, and electromagnetic tracking system. Operators were asked to guide a needle toward a visible point target. Performance was video-recorded and synchronized with the electromagnetic tracking data. A series of algorithms based on motor control theory and human information processing were used to convert raw tracking data into different performance indices. Scoring algorithms converted the tracking data into efficiency, quality, task difficulty, and targeting scores that were aggregated to create performance indices. After initial feasibility testing, a standardized assessment was developed. Operators (N = 12) with a broad spectrum of skill and experience were enrolled and tested. Overall scores were based on performance during ten simulated procedures. Prior clinical experience was used to independently estimate operator skill. RESULTS: When summed, the performance indices correlated well with estimated skill. Operators with minimal or no prior experience scored markedly lower than experienced operators. The overall score tended to increase according to operator's clinical experience. Operator experience was linked to decreased variation in multiple aspects of performance. The aggregated results of multiple trials provided the best correlation between estimated skill and performance. A metric for the operator's ability to maintain the needle aimed at the target discriminated between operators with different levels of experience. CONCLUSIONS: This study used a highly focused task model, standardized assessment, and objective data analysis to assess performance during simulated ultrasound-guided needle placement. The performance indices were closely related to operator experience.