Computer simulation as a component of catheter-based training

IntroductionComputer simulation has been used in a variety of training programs, ranging from airline piloting to general surgery. In this study we evaluate the use of simulation to train novice and advanced interventionalists in catheter-based techniques.MethodsTwenty-one physicians underwent evaluation in a simulator training program that involved placement of a carotid stent. Five participants were highly experienced in catheter-based techniques (>300 percutaneous cases), including carotid angioplasty and stenting (CAS); the remaining 16 participants were interventional novices (<5 percutaneous cases). The Procedicus VIST simulator, composed of real-time vascular imaging simulation software and a tactile interface coupled to angiographic catheters and guide wires, was used. After didactic instruction regarding CAS and use of the simulator, each participant performed a simulated CAS procedure. The participant's performance was supervised and evaluated by an expert interventionalist on the basis of 50 specific procedural steps with a maximal score of 100. Specific techniques of guide wire and catheter manipulation were subjectively assessed on a scale of 0 to 5 points based on ability. After evaluation of the initial simulated CAS procedure, each participant received a minimum of 2 hours of individualized training by the expert interventionalist, with the VIST simulator. Each participant then performed a second simulated CAS procedure, which was graded with the same scale. After completion, participants assessed the training program and its utility via survey questionnaire.ResultsThe average simulated score for novice participants after the training program improved significantly from 17.8 ± 15.6 to 69.8 ± 9.8 (P < .01), time to complete simulation decreased from 44 ± 10 minutes to 30 ± 8 minutes (P < .01), and fluoroscopy time decreased from 31 ± 7 minutes to 23 ± 7 minutes (P < .01). No statistically significant difference in score, total time, or fluoroscopy time was noted for experienced interventionalists. Improvement was noted in guide wire and catheter manipulation skills in novices.. Analysis of survey data from experienced interventionalists indicated that the simulated clinical scenarios were realistic and that the simulator could be a valuable tool if clinical and tactile feedback were improved. Novices also thought the simulated training was a valuable experience, and desired further training time.ConclusionsAn endovascular training program using the Procedicus VIST haptic simulator resulted in significant improvement in trainee facility with catheter-based techniques in a simulated clinical setting. Novice participants derived the greatest benefit from simulator training in a mentored program, whereas experienced interventionalists did not seem to derive significant benefit

The RATIONS (Reducing Activation of Tuberculosis by Improvement of Nutritional Status) study: a cluster randomised trial of nutritional support (food rations) to reduce TB incidence in household contacts of patients with microbiologically confirmed pulmonary tuberculosis in communities with a high prevalence of undernutrition, Jharkhand, India

Introduction India has the largest burden of cases and deaths related to tuberculosis (TB). Undernutrition is the leading risk factor accounting for TB incidence, while severe undernutrition is a common risk factor for mortality in patients with TB in India. The impact of nutritional supplementation on TB incidence is unknown, while few underpowered studies have assessed its impact on TB mortality. We designed an open-label, field-based cluster randomised trial to assess the impact of nutritional supplementation (with food rations) on TB incidence in a group at higher risk of TB infection and disease, viz household contacts (HHC) of patients with microbiologically confirmed pulmonary TB (PTB) in Jharkhand, a state with a high prevalence of undernutrition.Methods and analysis We shall enrol 2800 adult patients with PTB of the national TB programme, across 28 treatment units in 4 districts, and their approximately 11 200 eligible contacts. The sample size has 80% power to detect the primary outcome of 50% reduction in incidence of active TB in HHC over 2 years of follow-up. Patients and HHC in both the arms will undergo nutritional assessment and counselling. Patients will receive monthly food rations (supplying 1200 kcal and 52 g proteins/day) and multivitamins along with antitubercular treatment. The HHC in the intervention arm will receive food rations (supplying 750 kcal and 23 g proteins/day) and multivitamins while HHC in control arm will be on usual diet. The secondary outcomes in HHC will include effects on nutritional status, non-TB infections. Secondary outcomes in patients are effects on TB mortality, adherence, adverse effects, nutritional and performance status. Substudies will examine micronutrient status and effects on dietary intake, body composition, muscle strength and immune function.Ethics and dissemination The institutional ethics committee of ICMR-NIRT, Chennai, approved the study (289/NIRT-IEC/2018). The results will be disseminated in publications and presentations.Trial registration number Clinical Trial Registry of India: CTRI/2019/08/020490

The Use of Gadolinium for Arterial Interventions

Gadolinium (Gd) has been traditionally used as a non-nephrotoxic alternative to iodinated contrast for digital subtraction angiography (DSA) in patients with chronic renal insufficiency. However, its use has been questioned on the basis of reports of nephrotoxicity and its recent association with nephrogenic systemic fibrosis (NSF), a potentially lethal complication. Recently available data are conflicting with respect to the true safety profile of intra-arterial Gd. The purpose of this study was to examine the risk of contrast nephropathy and NSF after Gd exposure in a large population of azotemic patients undergoing DSA. A comprehensive database encompassing data on all patients who underwent DSA between June 2003 and December 2007 at the New York Presbyterian Hospital was retrospectively reviewed. Patients receiving Gd either alone or in combination with iodinated contrast during DSA were identified and further analyzed. Acute renal failure (ARF) was defined as an elevation in serum creatinine (Cr) by >0.5 mg/dL within 48 hours of exposure. Clinical follow-up was conducted through chart reviewing as well as telephonic interviews with patients and their primary care physicians. A total of 153 patients underwent 179 exposures to Gd either alone (33%) or in combination (67%) with iodinated contrast. Mean follow-up duration was 27.1 months. The mean Cr level was 1.94 ± 0.78 mg/dL and 1.96 ± 1.1 mg/dL before and after DSA, respectively. There were 20 (11.2%) instances of ARF. The mean Cr level before DSA was higher in patients who developed ARF versus those in the non-ARF group (2.7 ± 1.1 mg/dL vs. 1.9 ± 0.7 mg/dL, p = 0.004). In the ARF group, 12 patients had a return to baseline renal function, four experienced irreversible renal deterioration, and four needed dialysis (4.5% incidence of irreversible renal failure). There were 19 deaths at the time of this study (12.4%). The highest risk for the development of ARF after Gd exposure occurred in patients with Cr levels of >3.0 mg/dL before DSA and in those receiving >0.4 mmol/kg of Gd. For patients who received iodinated contrast in combination with Gd, there was a trend toward a higher risk for developing ARF as compared with those receiving only Gd. Finally, there were no instances of NSF identified in any of the patients who received intra-arterial Gd. Although Gd has the potential to cause kidney injury similar to iodinated contrast, the risk of irreversible renal failure and the requirement for dialysis is low. Life- or limb-threatening interventions should not be avoided in this patient cohort because of preexisting elevations in Cr. These data should help guide the use of Gd in patients with chronic renal insufficiency

Midterm outcomes after treatment of type II endoleaks associated with aneurysm sac expansion

To examine the outcomes following interventions for type II endoleaks in patients with aneurysm sac expansion after endovascular aneurysm repair (EVAR). A retrospective review was conducted of all patients who underwent treatment for type II endoleak from July 2001 to September 2010 in a single center. In this time period, 29 (4.7%) patients (22 men; mean age 78.6 years, range 54-87) were identified as having a type II endoleak and enlargement of the aneurysm sac, meeting the criterion for treatment. All patients had at least one attempted percutaneous intervention. Patients were followed both clinically and radiographically, with computed tomographic angiography every 3 to 12 months, over a follow-up period that ranged from 1 to 10 years (mean 3.5). Forty-eight interventions were performed on the 29 patients. Of these, 15 (56%) patients underwent multiple (2-4) procedures. Of the 11 endoleaks with an isolated inferior mesenteric artery identified as the source, initial success for transarterial embolization at 2 years was 72%, with 2 of the failures having successful secondary interventions. For the 18 endoleaks with a lumbar source, the success of the initial intervention was 17% at 2 years; repeated embolization attempts produced a 40% secondary success rate. Seven (24%) patients had continued endoleak despite multiple treatment attempts; 3 ultimately required elective aortic graft explantation. There were no ruptures or deaths during the study period. In a comparison of type II endoleak patients who had stable aneurysm sacs and those who had persistent sac expansion, the only significant differences in preoperative anatomical characteristics were a lower prevalence of mural thrombus (p = 0.036) and longer right iliac arteries (p = 0.012) in the group with sac expansion. Independent predictors of type II endoleak were mural thrombus (p<0.001), patent lumbar arteries (p = 0.004), aneurysm length (p = 0.011), and iliac artery length (p = 0.004). This study demonstrates that most patients require multiple reinterventions to treat type II endoleaks; specifically, lumbar artery embolization carries a low midterm success rate

Carotid angioplasty and stent-induced bradycardia and hypotension: Impact of prophylactic atropine administration and prior carotid endarterectomy

ObjectiveWe compared the physiologic effect of selective atropine administration for bradycardia with routine prophylactic administration, before balloon inflation, during carotid angioplasty and stenting (CAS). We also compared the incidence of procedural bradycardia and hypotension for CAS in patients with primary stenosis vs those with prior ipsilateral carotid endarterectomy (CEA).MethodsA total of 86 patients were treated with CAS at 3 institutions. Complete periprocedural information was available for 75 of these patients. The median degree of stenosis was 90% (range, 60%-99%). Indications for CAS were severe comorbidities (n = 49), prior CEA (n = 21), and prior neck radiation (n = 5). Twenty patients with primary lesions were treated selectively with atropine only if symptomatic bradycardia occurred (nonprophylactic group). Thirty-four patients with primary lesions received routine prophylactic atropine administration before balloon inflation or stent deployment (prophylactic group). The 21 patients with prior CEA received selective atropine treatment only if symptomatic bradycardia occurred (prior CEA group) and were analyzed separately. Mean age and cardiac comorbidities did not vary significantly either between the prophylactic and nonprophylactic atropine groups or between the primary and prior CEA patient groups. Outcome measures included bradycardia (decrease in heart rate >50% or absolute heart rate <40 bpm), hypotension (systolic blood pressure <90 mm Hg or mean blood pressure <50 mm Hg), requirement for vasopressors, and cardiac morbidity (myocardial infarction or congestive heart failure).ResultsThe overall incidence of hypotension and bradycardia in patients treated with CAS was 25 (33%) of 75. A decreased incidence of intraoperative bradycardia (9% vs 50%; P < .001) and perioperative cardiac morbidity (0% vs 15%; P< .05) was observed in patients with primary stenosis who received prophylactic atropine as compared with patients who did not receive prophylactic atropine. CAS after prior CEA was associated with a significantly lower incidence of perioperative bradycardia (10% vs 33%; P < .05), hypotension (5% vs 32%; P < .05), and vasopressor requirement (5% vs 30%; P < .05), with a trend toward a lower incidence of cardiac morbidity (0% vs 6%; not significant) as compared with patients treated with CAS for primary carotid lesions. There were no significant predictive demographic factors for bradycardia and hypotension after CAS.ConclusionsThe administration of prophylactic atropine before balloon inflation during CAS decreases the incidence of intraoperative bradycardia and cardiac morbidity in primary CAS patients. Periprocedural bradycardia, hypotension, and the need for vasopressors occur more frequently with primary CAS than with redo CAS procedures. On the basis of our data, we recommend that prophylactic atropine administration be considered in patients with primary carotid lesions undergoing CAS