ABSTRACT
BACKGROUND AND OBJECTIVES: Accurate needle control during ultrasound (US)-guided nerve blocks may be an elusive goal for the anesthesiologist. Despite modifications to increase echogenicity, needle visibility still requires precise alignment within the transducer beam. In this study, we evaluated a magnetically guided ultrasound (MGU) system that produces a real-time, graphic display of the needle position and trajectory that is independent of the US beam. METHODS: The MGU system was compared with echogenic needles and conventional ultrasound (CU) by anesthesiologists with and without prior experience performing US-guided nerve blocks. Participants were asked to perform tasks to quantify accuracy with respect to needle direction (directional accuracy) and needle tip position (positional accuracy). These evaluations were performed in a porcine tissue model. RESULTS: Regarding directional accuracy, inexperienced subjects were able to contact a target capsule with a single needle pass during both in-plane (IP) and out-of-plane (OOP) approaches using the magnetic guidance system. By contrast, using CU, subjects required redirection 3.8 ± 2.4 (P = 0.02), and 4.5 ± 3.9 (P = 0.04) times, respectively, for IP and OOP approaches. Experienced subjects contacted the target capsule with a single pass for both IP and OOP approaches when using the magnetic guidance system. With CU, experienced subjects were able to contact the target with a single pass using an IP approach but required redirection 3.4 ± 2.8 (P = 0.046) times during OOP approaches. Positional accuracy was also superior for both inexperienced (P = 0.04) and experienced (P = 0.02) users during an OOP approach. CONCLUSIONS: In a tissue model, the MGU system improved control of needle trajectory and needle tip position for both inexperienced and experienced subjects.
Subject(s)
Magnetics/instrumentation , Nerve Block/instrumentation , Ultrasonography, Interventional/instrumentation , Animals , Clinical Competence , Equipment Design , Humans , Learning Curve , Magnetics/methods , Materials Testing , Models, Animal , Motor Skills , Needles , Nerve Block/methods , Prospective Studies , Swine , Ultrasonography, Interventional/methods , UtahABSTRACT
There are no established prognostic factors or standardized therapies for hepatocellular carcinoma (HCC) recurrence in liver transplantation (LT). The aim of this study was to investigate impact of underlying patient condition on treatment and outcomes of recurrence of HCC after LT. The medical records of 268 LT patients with HCC were evaluated. Potential prognostic factors for survival after recurrence were evaluated, including recurrent tumor characteristics, medical/radiological/surgical therapies for recurrence, and an inflammatory marker (neutrophil/lymphocyte ratio). Laboratory tests at recurrence, including albumin, absolute lymphocyte count (ALC), prognostic nutritional index (PNI: ALC(/µL) × 0.005 + Albumin(g/dL) × 10), were evaluated as surrogate markers for underlying patient conditions. A total of 51 (19%) patients developed HCC recurrence. The use of sirolimus and sorafenib significantly improved outcome (p = 0.007 and 0.04), and better nutritional status (PNI ≥ 40) enhanced their efficacy. On multivariate analysis, low ALC (<500/µL) and albumin (<2.8 g/L) remained independent prognostic factors (p = 0.03 and 0.02; hazard ratio = 3.61 [Ref. >1000/µL] and 4.97 [Ref. >3.5 g/dL], respectively). Low PNI (<40) showed significantly lower survival rate after adjusting the risk (p = 0.006, hazard ratio = 3.29). Underlying patient conditions and nutritional status, represented by ALC and albumin, are important to successful cancer treatment and strong prognostic markers for survival after HCC recurrence.
