Stenting Surgery Research Articles

Utility of CT Perfusion Imaging in Patients With Vertebral Artery Stenosis Treated With Balloon Expandable Stent.

Objective: To investigate the clinical value of CT perfusion (CTP) imaging in vertebral artery stenosis stenting, so as to provide the basis for preoperative and postoperative evaluation. Ninety-seven patients with vertebral artery stenosis were accepted for endovascular stenting between Jan 2016 and Jan 2020. CT angiography, Digital Subtraction Angiography, and CTP were performed pre-operation and post-operation. The cerebral blood volume (CBV), cerebral blood flow (CBF), and mean transmit time (MTT) between the health and affected sides were analyzed statistically, and the imaging results pre- and post-operation were evaluated. The stenosis was relieved by endovascular stents in all 97 patients without serious complications. The abnormal perfusion was observed in 66 patients (68%). The differences in CBF and MTT between the diseased side and healthy side were statistically significant (P < 0.05). Compared with the preoperative imaging, the postoperative CTP was improved in 59 patients (89%). The differences in CBF and MTT between pre-operation and post-operation were statistically significant (P < 0.05). But there was no significant difference in CBV. CTP can sensitively reflect the perfusion of brain, and can also be used for preoperative and postoperative evaluation of vertebral artery stenting. It may be helpful as an adequate indicator of vertebral artery stenosis stent surgery.

Research on 3D Modeling Software Maya Digital Media Animation Assisted Brain Surgery Technology

Abstract This article uses the three-dimensional (3D) modeling software Maya and the 3D interactive software Unity3D to develop an interactive teaching system that integrates the display of the human brain, the display of the principle pathology of cerebral thrombosis, and the simulation of stent surgery in the brain. The use of this system can result in unlimited learning by multiple people, avoiding shortcomings such as insufficient resources, and strengthening the characteristics of interaction. For human brain models, functions such as zoom-in, rotation, and observation of a single part can be implemented, and text descriptions are provided. For the demonstration of cerebral thrombosis, animation is provided for simulation. For intra-brain stent surgery, the system can automatically demonstrate the surgical process, and it can be actually operated by the user, thereby enhancing the convenience and fun of student learning. This system uses Unity3D software as the main development tool. It uses the software’s advanced lighting system, particle system, and algorithms such as edge detection and screen post effects to establish the main frame of the system. It utilizes C # language for programming, thus enriching the functions of the system. On testing, the virtual interactive teaching system realized by the above method exhibits high interactivity, fun, and practicability.

Idiopathic intracranial hypertension: a review of diagnosis and management

With the increasing prevalence of obesity, the incidence of idiopathic intracranial hypertension (IIH) is rising. Headache and threat to vision are the predominant features and the principal cause of morbidity and reduced quality of life. Identification of papilloedema must prompt urgent investigation to exclude any underlying cause and management should be multi-disciplinary, focusing on protecting vision and reducing headache burden. Weight loss is the most effective and only disease modifying treatment for IIH but surgical interventions may need to be considered in some patients. Whilst optic nerve sheath fenestration and CSF diversion have established roles in protecting vision, there is increasing interest in venous sinus stenting and bariatric surgery as additional interventions that may have efficacy in the treatment of this condition.

Learning Curve and One-Year Outcome of XEN 45 Gel Stent Implantation in a Swedish Population.

PurposeEvaluation of 1-year-outcome of XEN 45 gel stent surgery in a Swedish cohort with regard to clinical success, complications, and learning curve.Patients and MethodsThis was a retrospective study of glaucoma patients undergoing glaucoma XEN-stent surgery alone or combined with phacoemulsification between December 2015 and May 2017. Intraocular pressure (IOP), number of medical agents, and adverse events were assessed. Clinical success rate was defined as achieving individual target pressure with/without medication.ResultsA total of 113 eyes were included in the final statistics. Mean age was 70.8±11.8 years. Primary open angle glaucoma (POAG) accounted for 46.9% and exfoliative glaucoma (PEXG) for 40.7%. Mean preoperative IOP was 23.8±6.2 mmHg and mean number of agents 3.4. After 1 year, mean IOP was reduced to 16.1±4.7 mmHg and medication to 1.34 substances on average. Failure rate at 1-year follow-up was 34% with no significant difference between POAG and PEXG. There was a trend of higher success rate for combined cases (P=0.116). Stents with malpositioned or curved appearance had significantly worse outcome. The failure rate of the most productive surgeon dropped from 33% to 10% from the first implantations. Temporary hypotony (19.5%) and choroidal detachment (9.7%) were the most common complications. Blockage of the inner stent lumen was common (8.8%), with a high proportion of failure.ConclusionXEN-stent surgery is a surgical option in uncontrolled glaucoma in both POAG and PEXG. A XEN-stent can reduce both IOP and the number of antiglaucoma medications needed. The learning curve is significant and stent positioning is crucial for optimal results. Combined XEN-cataract surgery is not inferior to stand-alone procedures. The long-time effectiveness is still to be proven.

Effect of Educational Intervention for Nurses about Pre and Post-Operative Care on Clinical Outcomes of Patients Undergoing Ureteral Stent Surgery

Effect of Educational Intervention for Nurses about Pre and Post-Operative Care on Clinical Outcomes of Patients Undergoing Ureteral Stent Surgery

The optimal time interval between the placement of self-expandable metallic stent and elective surgery in patients with obstructive colon cancer

A bridge to surgery (BTS) after a colonic stent for obstructive colon cancer has not been accepted as a standard treatment strategy. Also, there is no consensus regarding the optimal time interval for BTS. We aimed to identify the optimal timing for BTS after stent placement to decrease the oncologic risk. We retrospectively collected data of 174 patients who underwent BTS after stent placement for stage II or III obstructive colon cancer from five hospitals. We divided the patients into three groups based on the time interval for BTS after stent placement: within 7 days (Group 1), from 8 to 14 days (Group 2), and after 14 days (Group 3). The primary outcome was to compare the oncologic outcomes including overall survival (OS), disease-free survival (DFS), and recurrence rate (RR) among the three groups. Groups 1, 2, and 3 involved 75, 56, and 43 patients, respectively. Postoperative morbidity rates were 17.3%, 10.8%, and 9.3% in Groups 1, 2, and 3, respectively (P = 0.337). RRs were 16.0%, 35.7%, and 30.2% in Groups 1, 2, and 3, respectively (P = 0.029). In multivariate analysis, the time interval for BTS was an independent risk factor for DFS (P < 0.001; HR, 14.463; 95% CI, 1.458–3.255) and OS (P = 0.027; HR, 4.917; 95% CI, 1.071–3.059). In conclusion, the perioperative short-term outcome was not affected by the time interval of BTS. However, elective surgery within 7 days after colonic stent might be suggested to balance the short-term benefits and long-term oncologic risks.

Lamellar sclerectomy augmented XEN gel stent glaucoma surgery.

To describe a surgical technique to optimize XEN gel stent position and its outflow. A small 1- to 1.5-mm square lamellar sclerectomy was created at the external tip of the XEN gel stent implant. The lamellar scleral tissue, served as a patch graft, was secured at the gel stent insertion site. Four sequential, unselected, patients with failed primary XEN gel stent surgeries underwent bleb revisions with the technique described. These four patients achieved unmedicated intraocular pressures between 10 and 12 mmHg and a favourable bleb morphology despite repeated mitomycin C applications at 6months. Lamellar sclerectomy with auto-scleral graft augmented XEN gel stent surgery deliver successful short-term outcomes without major complications observed.

Pulmonary Artery Reconstruction After Failed Pulmonary Artery Stents

Pulmonary artery stents are widely deployed in patients with stenoses in the branch pulmonary arteries. However, stents do not address more peripheral sites of stenosis and invariably develop in-stent restenosis. The purpose of this study was to review our experience with pulmonary artery reconstruction after failed pulmonary artery stents. This was a retrospective study of 56 patients who underwent pulmonary artery reconstruction after failed pulmonary artery stents. These patients had undergone a median of 2 (range, 0-5) previous surgical procedures and 2 (range, 1-4) pulmonary artery stents. The median age at stent surgery was 5 (range, 0.3-23.6) years. The majority of stents (79%) were completely removed and patch augmented. The minority of stents (21%) were felt to be unremovable and thus were split longitudinally and reconstructed using a pulmonary artery homograft. There was 1 (1.8%) operative mortality. The mean pulmonary artery-to-aortic pressure ratio decreased from a preoperative value of 0.91 ± 0.21 to a postoperative value of 0.31 ± 0.07 (P < .001). The median hospital length of stay was 10 days. The median durationof follow-up was 1.8 years. There has been no midterm mortality. Six patients have undergone balloon dilation postoperatively for residual pulmonary artery stenosis. Pulmonary artery reconstruction resulted in a significant decrease in pulmonary artery-to-aortic pressure ratios. The subsequent need for reintervention on the pulmonary arteries has been relatively low (11% to date). These results suggest that patients with pulmonary artery stents can be successfully treated with surgical reconstruction.

Our experience with graft stents in the treatment of diseases of the main arteries of the brain

Objective – to study the efficacy and safety of stent grafts in the treatment of diseases of the cerebral arteries.Materials and methods. It was analysed results of treatment of 6 patients (3 men and 3 women) with disease of the main arteries of the brain, where stent graft was used. The youngest patient was 35 years old, the oldest was 60. Results were evaluated by data of somatic and neurological examination, selective cerebral angiography, computer and magnetic resonance imaging. Surgery performed within 1 to 3 months from the onset of the disease. On a modified Rankin scale four patients have 0 point, two have 1 point. All patients received double disaggregant therapy, clopidogrel 75 mg, and aspirin 100 mg per day before the intervention. Sensitivity to clopidogrel was determined by the method of light transmission aggregate. All interventions were performed under general anesthesia; the duration of the intervention ranged from 25 to 90 minutes, average mean was 45 minutes. Used for stent surgery Atrium Advanta V12 and Graftmaster.Results. In four cases, stent implantation had no technical difficulties. In two cases, technical difficulties arose due to the structural features of the stent system, in particular, the rigid system distal to the stent itself, which limits the stent navigation in curved areas. In one case, due to the use of rigid delivery system and implantation of the stent by the method of retrograde opening from the guide catheter was able to implant at the level of the aneurysm. In one case, the stent was implanted without covering the distal part of the artery, after stent implantation a stasis of contrast fluid in the aneurysm cavity was noted. Control angiography after 6 months to demonstrate total exclusion of an aneurysm from the bloodstream. Using the features of the stent, it was possible to separate the arteriovenous complicity between the vertebral artery and the paravertebral venous plexus with complete reconstruction of the artery. There were no intraoperative and postoperative complications. Duration of stay of patients in hospital 3–5 days. In all cases, reconstruction of the artery was achieved with the exception of an aneurysm from the bloodstream or disconnection of the arteriovenous shunt.Conclusions. The preliminary accumulated results of the use of stent grafts in the aneurysms of the extracranial carotid section indicate that this technique has advantages over “conservative surgical treatment” by reducing surgical trauma, no risk of damage to the cranial nerves, shorter stay time. In case of erosive bleeding and arteriovenous joints, the use of stent graft should be considered as a method of choice.

Outcomes of trabecular microbypass surgery: Comparison of resident trainees and attending surgeons

To determine the efficacy, safety, and surgical outcomes of trabecular microbypass stent (iStent) surgery performed by resident trainees and attending surgeons. Wills Eye Hospital, Philadelphia, Pennsylvania, USA. Retrospective case series. Records of all patients who had microbypass stent surgery by a resident at Wills Eye Hospital were retrospectively reviewed. The attending-performed group included any patient who had a microbypass stent implanted by an attending surgeon on the same day a resident case was performed. Between 2016 and 2018, 31 microbypass stents were implanted by a resident supervised by an attending and 93 microbypass stents were implanted by an attending surgeon on the day a resident case was performed. The mean follow-up was 16.2months±17.9 (SD). The mean intraocular pressure (IOP) decreased from 16.0±4.6mm Hg at baseline to 14.0±3.1mm Hg at most recent follow-up visit in the resident group (P=.02) and from 17.5±4.8mm Hg to 15.1±4.3mm Hg, respectively, in the attending group (P<.001). The final mean IOP and mean number of hypotensive medications were similar between the 2 groups (P=.83 and P=.12, respectively). Self-resolving hyphema occurred in 1 resident case and 2 attending cases. The resident group had 1 case of iridodialysis, which did not require additional surgery. One eye in the attending group ultimately required a trabeculectomy. Microbypass stent implantation by resident trainees with attending supervision had similar efficacy and safety as surgery performed by attending surgeons.

Myocardial infarction complicating blunt chest trauma: Case report and literature review

Myocardial infarction represents a mechanical complication of blunt chest trauma, a rare but life-threatening condition in which careful evaluation is mandatory. Early intervention is crucial, and coronary stenting or bypass graft surgery is described with generally satisfactory long-term outcomes. We present a 28-year-old man who developed extensive myocardial infarction and circulatory arrest after a blunt chest trauma in a professional water polo game. The cardiac computed tomography and the coronary angiography demonstrated left main artery dissection; the echocardiogram revealed anterior myocardial infarction with a severely decreased left ventricular ejection fraction, and the patient underwent coronary angioplasty with stent implantation. Six days later, he complained about chest pain due to acute stent thrombosis, and coronary artery bypass grafting was performed. Left ventricular heart failure was treated with specific heart failure drug therapy and a biventricular pacemaker and defibrillator. Ten years later, the patient has a good quality of life, is asymptomatic and works as a water polo coach under heart failure drug therapy and regular follow-up.

Possible Intraluminal Obstruction of the XEN45 Gel Stent Observed With Anterior Segment Optical Coherence Tomography.

We herein describe possible intraluminal obstruction because of a hyperreflective material found in anterior segment optical coherence tomography (AS-OCT) in 16 of 46 cases with XEN45 gel stent. This is a retrospective case series of 46 eyes of 39 patients with noncomplicated XEN45 gel stent surgery, analyzed with AS-OCT and slit-lamp photography after at least 6 postoperative months. Possible luminal obstruction in the subconjunctival segment of the implant was observed in 16 eyes of 15 patients, characterized by hyperreflective material on AS-OCT, which was not visible in slit-lamp photography. This was found in 15 eyes following combined procedures and in 1 eye following XEN45 alone. None showed signs of filtering bleb on AS-OCT or slit-lamp photography. In 1 case, the discontinuity between the hyperreflective material and subconjunctival opening of the implant tube was evidenced, and in another case, a focal deposit in the intracameral end of the implant was seen. We have successfully described the lumen implant deposit of material as a possible cause of late failure of the implant. AS-OCT allows the identification of such cases and may be useful to plan further postoperative interventions for better patient outcomes.

Two-Year Outcomes of XEN Gel Stent Surgery in Patients with Open-Angle Glaucoma

To evaluate the 2-year treatment outcomes of the XEN gel stent (Allergan, Inc, Irvine, CA) in glaucoma patients. Prospective, single-center interventional study. One hundred forty-nine eyes of 113 patients with open-angle glaucoma. Consecutive eyes with uncontrolled intraocular pressure (IOP) or signs of disease progression despite medical treatment were included to undergo either standalone XEN implantation or combined XEN implantation plus phacoemulsification surgery, both with mitomycin C injections. Primary efficacy outcome was success, defined as complete when the unmedicated IOP was 12 mmHg or less, 15 mmHg or less, or 18 mmHg or less and 20% lower than at baseline over the 2-year period and defined as qualified when the IOP fulfilled the same conditions with fewer medications than at baseline. Secondary measures were mean reduction in IOP and in the number of medications and the rates of reoperations. One hundred nine eyes (84 patients; mean age, 74.3 years) underwent XEN plus phacoemulsification surgery and 40 eyes (29 patients; mean age, 74.7 years) underwent standalone XEN surgery. Overall, 129 eyes (86.6%; 96 eyes of 75 XEN plus phacoemulsification patients and 33 eyes of 24 XEN standalone surgery patients) completed the study. Mean medicated IOP was 20.0±7.5 mmHg at baseline and 14.1±3.7 mmHg at 2 years (P < 0.01), a 29.3% IOP reduction. Mean number of medications dropped from 2.0±1.3 before surgery to 0.6±0.9 at 2 years (P < 0.001). Complete success was achieved in 18.2% of eyes using the 12 mmHg or less and 20% reduction criteria and in 44.4% using the 15 mmHg or less threshold. Needling with mitomycin C was performed in 58 eyes (45%). In all, 11.4% underwent reoperations. After 2 years, XEN gel stent surgery achieved a clinically and statistically significant reduction both in IOP and the number of antiglaucoma medications, while requiring a high rate of needling interventions.

Secondary interventions after iliac vein stenting for chronic proximal venous outflow obstruction

ObjectiveIliac vein stent placement is an increasingly common procedure in the treatment of chronic proximal venous outflow obstruction (PVOO), but secondary interventions after vein stent placement remain poorly characterized. Our goal was to identify the incidence, indications, operative findings, and outcomes of secondary interventions after the primary iliac vein stent procedure at a single institution. MethodsWe retrospectively reviewed the clinical history of 490 patients (57.6% female, 42.4% male; mean age, 60.77 years [range, 18-92 years]; 93.28% follow-up, with a mean follow-up of 308.59 days) who underwent iliac vein stent placement for PVOO between October 2013 and January 2016. We evaluated the clinical presentation, intraoperative findings, and outcomes of those patients requiring a secondary intervention after an initial iliac vein stent procedure. ResultsSecondary interventions after an initial stent placement were identified in 50 of 490 patients (10.2%; mean age, 61.54 years [range, 19-92 years]; 58% female [n = 29]). At the time of each individual intervention, 1, 18, 17, 1, and 13 patients had Clinical, Etiology, Anatomy, and Pathophysiology class 2, 3, 4, 5, and 6 disease, respectively. Of these 50 patients, 58% (n = 29) of secondary interventions were due to recurrence of symptoms after the initial stent surgery, 18% (n = 9) were due to the development of new symptoms, and 24% (n = 12) were due to persistence of symptoms. The primary cause of PVOO in the patient cohort was 52% (n = 26) extrinsic iliac vein compression, 28% post-thrombotic, and 20% mixed. Intraoperative findings during the secondary intervention included malposition or angulation of the stent (6% [n = 3]); acute deep venous thrombosis/thrombosis (14% [n = 7]); an additional lesion, that is, stenosis in a native iliac vein proximal or distal to the original lesion (68% [n = 34]); stenosis within the stent, that is, stent stenosis without finding of thrombus or isolated, focal intrastent thrombosis (38% [n = 19]); and impairment of flow of the contralateral vessel from the previously placed stent (6% [n = 3]). The types of secondary interventions included placement of a new stent (86% [n = 43]), isolated balloon angioplasty alone (10% [n = 5]), and catheter pharmacomechanical thrombectomy (14% [n = 7]). Symptomatic improvement was observed after the secondary intervention in 90% of patients (n = 45), whereas only 2% (n = 1) of patients experienced only a transient improvement, and 8% of patients (n = 4) reported no improvement in their symptoms after the secondary interventions. ConclusionsThis study establishes a secondary intervention rate of 10.2% after iliac vein stent placement for chronic PVOO and identifies discrete and definable intraoperative findings as targets for quality improvement. The very good results strongly suggest that an aggressive approach to treatment of these complications is warranted.

Recommendations for the management of elevated intraocular pressure due to bleb fibrosis after XEN gel stent implantation.

Surgical management of glaucoma offers a means of effective disease control. A gel stent that facilitates drainage to the subconjunctival space offers intraocular pressure (IOP) reduction similar to traditional glaucoma filtering surgeries in a less invasive manner. However, like all subconjunctival filtering procedures that result in a bleb, fibrosis can present as a cause of elevated IOP. The following proposed techniques and recommendations for managing elevated IOP due to bleb fibrosis after gel stent implantation are based on the clinical experience of the authors. The goal of this paper is to improve outcomes following gel stent surgery by providing guidance on assessment of bleb function and strategies for bleb enhancement.

Is a Day 1 postoperative review following ab interno Xen gel stent surgery for glaucoma needed?

PurposeTo assess whether a first day review is needed following Xen surgery in glaucoma patients.Patients and methodsWe performed a retrospective case note review of all Xen surgeries performed across four centers between August 2015 and May 2017. Intraocular pressure (IOP), number of medications, complications, and all further procedures were recorded.ResultsTwo hundred and fifty-nine cases from 226 patients were analyzed, 78 of 259 cases (30.1%) had numerical hypotony (<6 mmHg) on Day 1, but 60 had resolved by Week 1. Zero cases of hypotony required intervention at Day 1. Two of 259 cases (0.8%) had transient IOP of ≥20 mmHg due to air bubble/iris blockage on Day 1 with one case (0.4%) requiring iris manipulation at the slit-lamp. One case (0.4%) required IOP lowering medications at Day 1. All other complications and interventions in our series occurred at 1 week or beyond. Day 1 IOP was not shown to be a reliable indicator for outcomes at Week 1 (r2=0.2155), Month 1 (r2=0.0574), or Month 12 (r2=0.1580).ConclusionThe presence of significant complications requiring intervention at Day 1 was 0%. Only one case (0.4%) required topical IOP lowering medication and one case (0.4%) needed stent manipulation at Day 1. Day 1 IOP is not a reliable indicator of long-term outcomes in Xen surgeries. Removing Day 1 follow-up would have been safe in our series and it may be more effective to perform the first postoperative review of Xen surgery at Week 1.

Intracellular activation of complement C3 in Paneth cells improves repair of intestinal epithelia during acute injury.

To explore whether Paneth cells (PCs) and complement system collaborate in the repair of enteric epithelia during acute gastrointestinal injury (AGI). Wild-type C57BL/6 mice were employed to induce AGI by performing colon ascendens stent surgery, with sham-operated as control. Exogenous C3 treatment was applied at 6-h postsurgery. After 48 h, overall survival, intestinal damage severity, and C3 intracellular activation were assessed in both epithelial cells and PCs. AGI caused a high mortality, while C3 therapy significantly attenuated epithelial damages and improved survival. Besides, exogenous C3 in vitro enhanced the proliferation and activity of PCs. Importantly, intracellular C3 activation was observed inside of PCs under C3 co-stimulation in vitro. C3 immunotherapy might play a valuable role in turnover of gut epithelia through intracellular activation in PCs.

PATIENT-SPECIFIC BIOFIDELIC HUMAN CORONARY ARTERY SURROGATES

Coronary artery disease (CAD) is the number one killer for both men and women in the United States. To date, unavailability of human coronary arteries due to ethical and biosafety issues has not allowed for many experimental studies on understanding the pathophysiology of CAD. Also, patient-specific arterial blockage conditions are very difficult to estimate using 2D imaging, which prevents the development of effective surgical mitigation steps. Additionally, to date, a majority of stent surgery failures (over 50%), mainly attributed to poor stent design (such as an oversized stent causing local damage of arterial wall and subsequent growth of scar tissue through the stent leading to re-blocking the artery, or in-stent restenosis), are impossible to evaluate. In the current work, a methodology to fabricate patient-specific three-layer biofidelic coronary artery surrogates was developed. This novel method involves the generation of a true-scale MRI-based patient-specific 3D arterial lumen model, which is 3D printed. A four-part silicone material system is developed, which precisely mimics the nonlinear biomechanical behavior of arterial layers, namely the intima (innermost), media (middle) and adventitia (outer). Using the 3D printed arterial lumen model as a positive mold, thin layers ([Formula: see text][Formula: see text]mm) of the layer-specific silicone-based materials are deposited, and subsequently pulled out once cured. The final product is a three-layer coronary artery model which is exactly of the same size and dimensions, and similar mechanical property as that of the actual coronary artery of a patient. Such surrogate models would be extremely helpful for cardiologists and heart surgeons to understand patient-specific atherosclerotic conditions (based on the location and size of blockages), simulate CAD-based surgeries and also evaluate stent implantation procedures. Additionally, these coronary artery surrogate models will allow stent manufacturers to design better and more reliable stents in the future to avoid stent oversizing-based arterial damage conditions and improve stent deployment techniques.

How Much is the Value of Genomic Test Information? Evidence from Post-Cardiac-Stent Care Decisions

Personalized medicine aided by new genomic and molecular diagnostic technologies can improve the quality of care. However, these new technologies are often expensive and the value they offer to any individual patient are uncertain. We propose a data-driven approach to identify patients who would benefit the most from these new diagnostic technologies in the specific context of cardiac stent surgery. Our approach is based on a structural econometric model of how physicians choose medication by balancing various risk factors. We estimate the proposed model from a dataset containing patient attributes, physicians’ choice of medications, and test results of 427 stent surgery patients, 175 of whom received a new genomic test. The estimated model reveals that patient’s medical and socioeconomic conditions play a significant role in the physician’s choice of medication after the surgery. Through out-of-sample prediction on a set of matched parallel patient groups — one receiving genomic testing and the other not — we show that our proposed model can be used to estimate the value a patient will receive from such testing based on patient attributes more accurately than existing popular statistical models. Policy simulations show that identifying and testing of the patients likely to benefit the most can reduce the patient disutility by 7.6% and provide benefit from the test sooner to those who need it the most. Finally, we show that the model can be used to design a revenue-neutral subsidy for those at low socioeconomic status to further reduce the population disutility.

P494Long-term outcome of drug-eluting stent versus bypass surgery in hemodialysis patients with coronary artery disease

P494Long-term outcome of drug-eluting stent versus bypass surgery in hemodialysis patients with coronary artery disease