Security and reliability of CUSTOMBONE cranioplasties: A prospective multicentric study.

BACKGROUND: Repairing bone defects generated by craniectomy is a major therapeutic challenge in terms of bone consolidation as well as functional and cognitive recovery. Furthermore, these surgical procedures are often grafted with complications such as infections, breaches, displacements and rejections leading to failure and thus explantation of the prosthesis. OBJECTIVE: To evaluate cumulative explantation and infection rates following the implantation of a tailored cranioplasty CUSTOMBONE prosthesis made of porous hydroxyapatite. One hundred and ten consecutive patients requiring cranial reconstruction for a bone defect were prospectively included in a multicenter study constituted of 21 centres between December 2012 and July 2014. Follow-up lasted 2 years. RESULTS: Mean age of patients included in the study was 42±15 years old (y.o), composed mainly by men (57.27%). Explantations of the CUSTOMBONE prosthesis were performed in 13/110 (11.8%) patients, significantly due to infections: 9/13 (69.2%) (p<0.0001), with 2 (15.4%) implant fracture, 1 (7.7%) skin defect and 1 (7.7%) following the mobilization of the implant. Cumulative explantation rates were successively 4.6% (SD 2.0), 7.4% (SD 2.5), 9.4% (SD 2.8) and 11.8% (SD 2.9%) at 2, 6, 12 and 24 months. Infections were identified in 16/110 (14.5%): 8/16 (50%) superficial and 8/16 (50%) deep. None of the following elements, whether demographic characteristics, indications, size, location of the implant, redo surgery, co-morbidities or medical history, were statistically identified as risk factors for prosthesis explantation or infection. CONCLUSION: Our study provides relevant clinical evidence on the performance and safety of CUSTOMBONE prosthesis in cranial procedures. Complications that are difficulty incompressible mainly occur during the first 6 months, but can appear at a later stage (>1 year). Thus assiduous, regular and long-term surveillances are necessary.

Covered vs bare stent for distal malignant biliary obstruction due to primary common biliary cancer.

ABSTRACT: This study was designed as a means of comparing the clinical efficacy and long-term outcomes of covered vs bare stent insertion as a treatment for distal malignant biliary obstruction (DMBO) caused by primary common biliary cancer (PCBC).This retrospective study was designed using data collected between January 2012 and December 2019 to assess the short- and long-term outcomes in patients with DMBO caused by PCBC treated by inserting either bare or covered stents were compared.Ninety two patients with DMBO caused by PCBC were divided between bare (n = 51) or covered (n = 41) stent groups. Technical success rates in both groups were 100%. Clinical success of bare vs covered stent use were 96.1% and 97.6% (P = 1.00). Stent dysfunction was seen in 17 and 6 patients in the bare and covered stent groups, respectively (P = .04). The median stent patency for bare and covered stents was 177 and 195 days, respectively (P = .51). The median survival was 188 and 200 days in the bare and covered stent groups, respectively (P = .85).For patients with DMBO caused by PCBC, using bare vs covered stents yields similar clinical efficacy and long term outcomes.

Society of Interventional Radiology Clinical Practice Guideline for Inferior Vena Cava Filters in the Treatment of Patients with Venous Thromboembolic Disease: Developed in collaboration with the American College of Cardiology, American College of Chest Physicians, American College of Surgeons Committee on Trauma, American Heart Association, Society for Vascular Surgery, and Society for Vascular Medicine.

PURPOSE: To provide evidence-based recommendations on the use of inferior vena cava (IVC) filters in the treatment of patients with or at substantial risk of venous thromboembolic disease. MATERIALS AND METHODS: A multidisciplinary expert panel developed key questions to address in the guideline, and a systematic review of the literature was conducted. Evidence was graded based on a standard methodology, which was used to inform the development of recommendations. RESULTS: The systematic review identified a total of 34 studies that provided the evidence base for the guideline. The expert panel agreed on 18 recommendations. CONCLUSIONS: Although the evidence on the use of IVC filters in patients with or at risk of venous thromboembolic disease varies in strength and quality, the panel provides recommendations for the use of IVC filters in a variety of clinical scenarios. Additional research is needed to optimize care for this patient population.

Ureteral stents: the good the bad and the ugly.

PURPOSE OF REVIEW: Ureteral stents are necessary in the routine practice of an urologist. Choosing the correct stent and being aware of the options available will allow urologists to provide the best possible care for patients and value to the healthcare system. This review seeks to educate urologists regarding improvements in stent technology currently available or in development. RECENT FINDINGS: Research from around the world is underway to discover an ideal stent - one that is comfortable for patients, resists infection and encrustation and is affordable for hospital systems. Stent design alterations and stent coatings are revealing reductions in encrustation and bacterial colonization. Biodegradable stents and magnetic stents are being tested to prevent the discomfort of cystoscopic removal. Intraureteral stents are proving efficacious while eliminating an irritating coil from the bladder and the symptoms associated with it. SUMMARY: The studies highlighted in this review provide encouraging results in the pursuit of the ideal stent while opening discussion around new concepts and further areas of research.

Training and Transfer Effect of FluoroSim, an Augmented Reality Fluoroscopic Simulator for Dynamic Hip Screw Guidewire Insertion: A Single-Blinded Randomized Controlled Trial.

BACKGROUND: FluoroSim, a novel fluoroscopic simulator, can be used to practice dynamic hip screw (DHS) guidewire insertion in a high-fidelity clinical scenario. Our aim was to demonstrate a training effect in undergraduate medical students who are not familiar with this operation and its simulation. METHODS: Forty-five undergraduate medical students were recruited and randomized to either training (n = 23) or control (n = 22) cohorts. The training cohort had more exposure to FluoroSim (5 attempts each week) over a 2-week period (with a 1-week washout period in between) compared with the control cohort (a single attempt 1 week apart) over a 2-week period. Five real-time objective performance metrics were recorded: (1) tip-apex distance (TAD) (mm), (2) predicted cut-out rate (%), (3) total procedural time (sec), (4) total number of radiographs (n), and (5) total number of guidewire retries (n). RESULTS: At baseline, there was no significant difference in the performance metrics, which confirmed the absence of a selection bias. The intragroup training effect demonstrated a significant improvement in all metrics for the training cohort only. A significant difference between groups was demonstrated as the training cohort significantly outperformed the control cohort in 3 metrics (procedural time [25%], number of radiographs [57%], and number of guidewire retries [100%]; p < 0.001). A learning curve showed an inversely proportional correlation between frequency of attempts and procedural time as well as the number of digital fluoroscopic radiographs that were made, indicating the development of psychomotor skills. There was also an improved baseline of the learning curve after the 1-week washout period, suggesting skill retention. CONCLUSIONS: Skill acquisition with the FluoroSim system was demonstrated with repeat exposure in a safe, radiation-free high-fidelity clinical simulation with actual operating room equipment. The task of DHS guidewire insertion requires cognitive and psychomotor skills that take a variable number of attempts to acquire, as demonstrated on the learning curve. Additional work is required to demonstrate that the skill tested by the FluoroSim is the same skill that is required for intraoperative DHS guidewire insertion. However, use of the FluoroSim provides improvement in skills with extra-clinical training opportunities for orthopaedic trainees. CLINICAL RELEVANCE: FluoroSim has demonstrated validity and training effect. It has the potential to be approved for possible use on patients in the operating room to help surgeons with the operation. Consequently, operating time, accuracy of TAD, and surgical outcomes may all be improved.

Radiographic assessment of overlengthening of the MoPyC radial head prosthesis: a cadaveric study.

INTRODUCTION: The aim of this study was to evaluate a radiographic measurement method for assessment of overlengthening of the MoPyC radial head prosthesis. MATERIALS AND METHODS: Seven cadaver specimens were studied in ten stages: native specimen (1), radial head resection (2), and implantation of the MoPyC radial head prostheses (Bioprofile, Tornier, Montbonnot-Saint-Martin, France) in four increasing length (correct length, overlengthening of 1.5 mm, 3 mm, and 5 mm) with an intact medial collateral ligament (MCL 3-6) and following transection of the MCL (7-10). The radiographic measurement method according to Athwal et al. was evaluated to detect overlengthening. Statistical analysis included calculation of the diagnostic accuracy of the radiographic method. RESULTS: The radiographic measurement method correctly determined the size of the radial head prosthesis within ± 1 mm in 224 of 336 scenarios (67%) and within ± 2 mm in 320 of 336 scenarios (95%). With a threshold value of ≥ 1 mm, the overall diagnostic sensitivity for detecting overlengthening when it was present and was 90% and the specificity was 79%. The sensitivity was higher with increasing size of the prosthesis: in cases with overlengthening of 1.5 mm, the sensitivity was 76%, with an overlengthening of 3 mm, the sensitivity was 95%, and with an overlengthening of 5 mm, the sensitivity was 100%. CONCLUSION: The radiographic measurement method of Athwal et al. can be used to estimate and to diagnose the magnitude overlengthening of the MoPyC radial head prosthesis. However, the sensitivity is limited (76%) in cases with a small amount of overlengthening of 1.5 mm.

HeartWare Ventricular Assist Device Implantation for Pediatric Heart Failure-A Single Center Approach.

While pediatric HeartWare HVAD application has increased, determining candidacy and timing for initiation of pediatric VAD support has remained a challenge. We present our experience with a systematic approach to HVAD implantation as a bridge to pediatric heart transplantation. We performed a retrospective, single center review of pediatric patients (n = 11) who underwent HVAD implantation between September 2014 and January 2018. Primary endpoints evaluated were survival to heart transplantation, need for right ventricular assist device (RVAD) at any point, ongoing HVAD support, or death. Median patient age was 11 years (range: 3-16). Median BSA was 1.25 m2 (range: 0.56-2.1). Heart failure etiologies requiring support were dilated cardiomyopathy (n = 8), myocarditis (n = 1), congenital mitral valve disease (n = 1), and single ventricle heart failure (n = 1). Median time from cardiac ICU admission for heart failure to HVAD placement was 15 days (range 3-55), based on standardized VAD implantation criteria involving imaging assessment and noncardiac organ evaluation. The majority of patients (91%) were INTERMACS Level 2 at time of implant. Three patients (27%) had CentriMag RVAD placement at time of HVAD implantation. Two of these three patients had successful RVAD explanation within 2 weeks. Median length of HVAD support was 60 days (range 6-405 days). Among the 11 patients, survival during HVAD therapy to date is 91% (10/11) with 9 (82%) bridged to heart transplantation and one (9%) continuing to receive support. Posttransplant survival has been 100%, with median follow-up of 573 days (range 152-1126). A systematic approach to HVAD implantation can provide excellent results in pediatric heart failure management for a variety of etiologies and broad BSA range.

A Pilot Study Comparing 2- and 3-dimensional Ultrasound Imaging for Confirmation of Essure Fallopian Tube Pregnancy Prevention Implants.

STUDY OBJECTIVE: To show the feasibility of 2-dimensional (2D) ultrasound (US) imaging compared with 3-dimensional (3D) US to identify the location of implants and assess if the classification developed by Simorre et al in 2016 was applicable to the 2 types of US imaging (i.e., 2D and 3D). DESIGN: A prospective study (Canadian Task Force classification II-2). SETTING: The department of obstetrics and gynecology in a teaching hospital. PATIENTS: One hundred fifty patients who had undergone hysteroscopic sterilization with Essure (Bayer Pharma AG Laboratory, Lyon, France) fallopian tube pregnancy prevention implants were invited by letter to participate in the study; 50 replied positively between January and August 2017. INTERVENTIONS: An initial 2D US was performed followed by 3D US reconstruction. The primary end point was to compare the identification of device placement with 2D and 3D US imaging procedures according to this new classification. Secondary considerations were to evaluate the difficulty of attaining images, the quality of implant curvature, the duration of each imaging procedure, and the number of images performed for each technique. MEASUREMENTS AND MAIN RESULTS: Ninety-six percent of tubal implants were observed via 3D US compared with 100% via 2D US. The mean time of 2D US was 14.64 seconds for the right fallopian tube and 15.25 seconds for the left fallopian tube compared with 25.11 seconds for the right and 31.57 seconds for the left fallopian tube in 3D US (p <.01). The mean number of image acquisitions per patient was 1.02 (±0.14 standard deviation) for 2D US compared with 1.37 (±0.64 standard deviation) for 3D US (p <.01). The sonographer had no difficulty performing 2D US in 88% of cases compared with 58% of 3D US cases. CONCLUSIONS: Two-dimensional ultrasound appears to be an acceptable alternative to 3D US. We propose a 2D classification for cross section device localization to facilitate image interpretation.

Is the New Infant Jarvik 2015 Suitable for Patients<8 kg? In Vitro Study Using a Hybrid Simulator.

Our aim was to study the feasibility of implanting the Infant Jarvik 2015 in patients weighing less than 8 kg. The Infant Jarvik 2015 left ventricular assist device (LVAD) was tested in a hybrid simulator of the cardiovascular system reproducing specific patients' hemodynamics for different patient weights (2-7 kg). For each weight, the sensitivity of the pump to different circulatory parameters (peripheral resistance, left ventricular elastance, right ventricular elastance, heart rate, and heart filling characteristics) has been tested repeating for each experiment a pump ramp (10 000-18 000 rpm). The increase in the pump speed causes a decrease (increase) in the left (right) atrial pressure, an increase (decrease) in the arterial systemic (pulmonary) pressure, an increase in the right ventricular pressure, a decrease (increase) in the left (right) ventricular volume, a decrease in the left ventricular cardiac output, an increase in the LVAD output and an increase in the right ventricular cardiac output (total cardiac output). Suction was observed for lower weight patients and for higher pump speed in the case of vasodilation, left ventricular recovery, bradycardia, right ventricular failure, and left ventricular hypertrophy. Backflow was observed in the case of left ventricular recovery at lower pump speed. In the hybrid simulator, the Infant Jarvik 2015 could be suitable for the implantation in patients lower than 8 kg because of the stability of the device respect to the cardio/circulatory changes (low frequency of suction and backflow) and because of the capability of the device to maintain adequate patient hemodynamics.

The 2018 ISHLT/APM/AST/ICCAC/STSW Recommendations for the Psychosocial Evaluation of Adult Cardiothoracic Transplant Candidates and Candidates for Long-term Mechanical Circulatory Support.

The psychosocial evaluation is well-recognized as an important component of the multifaceted assessment process to determine candidacy for heart transplantation, lung transplantation, and long-term mechanical circulatory support (MCS). However, there is no consensus-based set of recommendations for either the full range of psychosocial domains to be assessed during the evaluation, or the set of processes and procedures to be used to conduct the evaluation, report its findings, and monitor patients' receipt of and response to interventions for any problems identified. This document provides recommendations on both evaluation content and process. It represents a collaborative effort of the International Society for Heart and Lung Transplantation (ISHLT) and the Academy of Psychosomatic Medicine, American Society of Transplantation, International Consortium of Circulatory Assist Clinicians, and Society for Transplant Social Workers. The Nursing, Health Science and Allied Health Council of the ISHLT organized a Writing Committee composed of international experts representing the ISHLT and the collaborating societies. This Committee synthesized expert opinion and conducted a comprehensive literature review to support the psychosocial evaluation content and process recommendations that were developed. The recommendations are intended to dovetail with current ISHLT guidelines and consensus statements for the selection of candidates for cardiothoracic transplantation and MCS implantation. Moreover, the recommendations are designed to promote consistency across programs in the performance of the psychosocial evaluation by proposing a core set of content domains and processes that can be expanded as needed to meet programs' unique needs and goals.

Direct comparison of the novel automated screening tool (AST) versus the manual screening tool (MST) in patients with already implanted subcutaneous ICD.

BACKGROUND: The subcutaneous implantable cardioverter-defibrillator (S-ICD) has evolved as a valuable alternative to the transvenous ICD, especially in young patients. Unfortunately, some of these patients are ineligible for S-ICD implantation due to specific electrocardiographic features. So far, these patients were identified by mandatory pre-implantation screening using the manual screening tool (MST), which lacks objective value. Therefore, a novel automated screening tool (AST) has been introduced recently for objective screening, which has not been evaluated yet. METHODS/RESULTS: We here first investigate the novel AST, in direct comparison to MST, in 33 consecutive patients with already implanted S-ICD system to compare predicted eligibility by screening tools with true sensing of the S-ICD system. Both screening tools reliably predicted true ineligible single vectors, but also suggested overall ineligibility in a similar fraction of patients (MST: 3.0%; AST: 6.1%), albeit the implanted S-ICD worked flawlessly in these patients. AST did not predict the finally selected sensing vector better than MST. There was a surprising mismatch between AST and MST for the predicted eligibility of single vectors; only in 49% of patients did both screening tools predict eligibility for the same vectors. CONCLUSIONS: The novel AST predicted overall eligibility approximately similar to MST. Both tools predicted ineligibility in a few patients, who were actually eligible. There was a striking mismatch between both screening tools when eligibility of single vectors was predicted. Thus, the AST seems to be a valuable advance, due to its standardized and objective process, but it still lacks specificity.

Hospitalization metrics associated with hospital-level variation in inferior vena cava filter utilization for patients with venous thromboembolism in the United States: Implications for quality of care.

Variation in the use of inferior vena cava filters (IVCFs) across hospitals has been observed, suggesting differences in quality of care. Hospitalization metrics associated with venous thromboembolism (VTE) patients have not been compared based on IVCF utilization rates using a national sample. We conducted a descriptive retrospective study using the Nationwide Readmissions Database (NRD) to delineate the variability of hospitalization metrics across the hospital quartiles of IVCF utilization for VTE patients. The NRD included all-payer administrative inpatient records drawn from 22 states. Adult (≥ 18 years) patients with VTE hospitalizations with or without IVCF were identified from January 1, 2013 through December 31, 2014 and hospitals were divided into quartiles based on the IVCF utilization rate as a proportion of VTE patients. Primary outcome measures were observed rates of in-hospital mortality, 30-day all-cause readmissions and VTE-related readmissions, cost, and length of stay. Patient case-mix characteristics and hospital-level factors by hospital quartiles of IVCF utilization rates, were compared. Overall, 12.29% of VTE patients had IVCF placement, with IVCF utilization ranging from 0% to 46.84%. The highest quartile had fewer pulmonary embolism patients relative to deep vein thrombosis patients, and older patient ages were present in higher quartiles. The highest quartile of hospitals placing IVCFs were more often private, for-profit, and non-teaching. Patient and hospital characteristics and hospitalization metrics varied by IVCF utilization rates, but hospitalization outcomes for non-IVCF patients varied most between quartiles. Future work investigating the implications of IVCF utilization rates as a measure of quality of care for VTE patients is needed.

Optimization of pillar electrodes in subretinal prosthesis for enhanced proximity to target neurons.

OBJECTIVE: High-resolution prosthetic vision requires dense stimulating arrays with small electrodes. However, such miniaturization reduces electrode capacitance and penetration of electric field into tissue. We evaluate potential solutions to these problems with subretinal implants based on utilization of pillar electrodes. APPROACH: To study integration of three-dimensional (3D) implants with retinal tissue, we fabricated arrays with varying pillar diameter, pitch, and height, and implanted beneath the degenerate retina in rats (Royal College of Surgeons, RCS). Tissue integration was evaluated six weeks post-op using histology and whole-mount confocal fluorescence imaging. The electric field generated by various electrode configurations was calculated in COMSOL, and stimulation thresholds assessed using a model of network-mediated retinal response. MAIN RESULTS: Retinal tissue migrated into the space between pillars with no visible gliosis in 90% of implanted arrays. Pillars with 10 µm height reached the middle of the inner nuclear layer (INL), while 22 µm pillars reached the upper portion of the INL. Electroplated pillars with dome-shaped caps increase the active electrode surface area. Selective deposition of sputtered iridium oxide onto the cap ensures localization of the current injection to the pillar top, obviating the need to insulate the pillar sidewall. According to computational model, pillars having a cathodic return electrode above the INL and active anodic ring electrode at the surface of the implant would enable six times lower stimulation threshold, compared to planar arrays with circumferential return, but suffer from greater cross-talk between the neighboring pixels. SIGNIFICANCE: 3D electrodes in subretinal prostheses help reduce electrode-tissue separation and decrease stimulation thresholds to enable smaller pixels, and thereby improve visual acuity of prosthetic vision.

Immediate, short-, and long-term changes in tracheal stent diameter, length, and positioning after placement in dogs with tracheal collapse syndrome.

BACKGROUND: Intraluminal tracheal stenting is a minimally invasive procedure shown to have variable degrees of success in managing clinical signs associated with tracheal collapse syndrome (CTCS) in dogs. OBJECTIVES: Identify immediate post-stent changes in tracheal diameter, determine the extent of stent migration, and stent shortening after stent placement in the immediate-, short-, and long-term periods, and evaluate inter-observer reliability of radiographic measurements. ANIMALS: Fifty client-owned dogs. METHODS: Retrospective study in which medical records were reviewed in dogs with CTCS treated with an intraluminal tracheal stent. Data collected included signalment, location, and type of collapse, stent diameter and length, and post-stent placement radiographic follow-up times. Radiographs were used to obtain pre-stent tracheal measurements and post-stent placement measurements. RESULTS: Immediate mean percentage change was 5.14%, 5.49%, and 21.64% for cervical, thoracic inlet, and intra-thoracic tracheal diameters, respectively. Ultimate mean follow-up time was 446 days, with mean percentage change of 2.55%, 15.09%, and 8.65% for cervical, thoracic inlet, and intra-thoracic tracheal diameters, respectively. Initial mean stent length was 26.72% higher than nominal length and ultimate long-term tracheal mean stent shortening was only 9.90%. No significant stent migration was identified in the immediate, short-, or long-term periods. Good inter-observer agreement of radiographic measurements was found among observers of variable experience level. CONCLUSIONS AND CLINICAL IMPORTANCE: Use of an intraluminal tracheal stent for CTCS is associated with minimal stent shortening with no clinically relevant stent migration after fluoroscopic placement. Precise stent sizing and placement techniques likely play important roles in avoiding these reported complications.

[Long-term efficacy of percutaneous mechanical thrombectomy combined with stent implantation in treatment of acute iliofemoral venous thrombosis].

OBJECTIVE: To evaluate the long-term efficacy of percutaneous mechanical thrombectomy (PMT) combined with stent implantation in treatment of acute iliofemoral vein thrombosis. METHODS: Seventy patients with acute iliac vein thrombosis were treated with PMT combined stent implantation in Ningbo No.2 Hospital from November 2015 to November 2017. During the follow-up, the improvement of blood flow was evaluated, the occurrence of post-thrombotic syndrome was assessed by the Villalta rating scale, and the stent patency was examined with lower extremity ultrasound or angiography. RESULTS: The blood flow was significantly improved after procedure in all 70 patients, including 62 cases (88.6%) of grade Ⅲ clearance, 5 cases (7.1%) of grade Ⅱ clearance, and 3 cases (4.3%) of grade Ⅰ clearance. No significant complications occurred during the treatment. The patients were followed up for (15.0±2.5) months. During the follow-up, 64 patients (91.4%) had unobstructed stents, and 9 patients (12.8%) had post-thrombotic syndrome. CONCLUSIONS: PMT combined with stent implantation is effective in the treatment of acute iliac vein thrombosis with a high medium-and long-term stent patency rate.

Accuracy of screw fixation using the O-arm® and StealthStation® navigation system for unstable pelvic ring fractures.

PURPOSE: Screw fixation for unstable pelvic ring fractures is generally performed using the C-arm. However, some studies reported erroneous piercing with screws, nerve injuries, and vessel injuries. Recent studies have reported the efficacy of screw fixations using navigation systems. The purpose of this retrospective study was to investigate the accuracy of screw fixation using the O-arm® imaging system and StealthStation® navigation system for unstable pelvic ring fractures. METHODS: The participants were 10 patients with unstable pelvic ring fractures, who underwent screw fixations using the O-arm StealthStation navigation system (nine cases with iliosacral screw and one case with lateral compression screw). We investigated operation duration, bleeding during operation, the presence of complications during operation, and the presence of cortical bone perforation by the screws based on postoperative CT scan images. We also measured the difference in screw tip positions between intraoperative navigation screen shot images and postoperative CT scan images. RESULTS: The average operation duration was 71 min, average bleeding was 12 ml, and there were no nerve or vessel injuries during the operation. There was no cortical bone perforation by the screws. The average difference between intraoperative navigation images and postoperative CT images was 2.5 ± 0.9 mm, for all 18 screws used in this study. CONCLUSION: Our results suggest that the O-arm StealthStation navigation system provides accurate screw fixation for unstable pelvic ring fractures.

An optimized content-aware image retargeting method: toward expanding the perceived visual field of the high-density retinal prosthesis recipients.

OBJECTIVE: Retinal prosthesis devices have shown great value in restoring some sight for individuals with profoundly impaired vision, but the visual acuity and visual field provided by prostheses greatly limit recipients' visual experience. In this paper, we employ computer vision approaches to seek to expand the perceptible visual field in patients implanted potentially with a high-density retinal prosthesis while maintaining visual acuity as much as possible. APPROACH: We propose an optimized content-aware image retargeting method, by introducing salient object detection based on color and intensity-difference contrast, aiming to remap important information of a scene into a small visual field and preserve their original scale as much as possible. It may improve prosthetic recipients' perceived visual field and aid in performing some visual tasks (e.g. object detection and object recognition). To verify our method, psychophysical experiments, detecting object number and recognizing objects, are conducted under simulated prosthetic vision. As control, we use three other image retargeting techniques, including Cropping, Scaling, and seam-assisted shrinkability. MAIN RESULTS: Results show that our method outperforms in preserving more key features and has significantly higher recognition accuracy in comparison with other three image retargeting methods under the condition of small visual field and low-resolution. SIGNIFICANCE: The proposed method is beneficial to expand the perceived visual field of prosthesis recipients and improve their object detection and recognition performance. It suggests that our method may provide an effective option for image processing module in future high-density retinal implants.