Mechanical Device Failure Research Articles

Is it safe to implant a penile prosthesis in a solid organ transplant recipient? A systematic review.

Solid organ transplant recipients exhibit an elevated incidence of erectile dysfunction, attributed to comorbidities and specific factors associated with organ failure. While treatment mirrors the general population's, response rates are lower, and there is a heightened concern about implanting a penile prosthesis in immunocompromised patients due to the potential occurrence of severe complications. The aim of this study was to assess the safety of penile prostheses in this population. Among fourteen included studies, ten were case reports or series of cases, and four were non randomized case-control studies with non-transplanted patients as controls. Complications affected 34 patients (11.15%), with mechanical device failures in 18 cases (5.9%) and infections in 13 cases (4.26%). Most infections required hospitalization, antibiotic treatment, and prosthesis removal, with two cases of life-threatening Fournier's gangrene. Case-control studies revealed no differences in overall reoperation rates between transplant recipients and controls. However, pelvic organ transplant recipients undergoing three-piece prosthesis implantation showed higher complications rates related to reservoir issues. Despite limited evidence, case-control studies demonstrated a generally low/moderate risk of bias within each specific domain, although overall bias was moderate/severe. As a result, clinicians may mitigate concerns regarding penile prosthesis implantation in solid organ transplant recipients.

(414) Double Distal Fixation Stitch

Abstract Introduction Distal cylinder extrusion is not a common complication of penile prothesis surgery when compared to mechanical device failure but can have very serious complications if not addressed properly. Reported revision surgery for IPP implantation is more commonly required for cosmetic and erosion problems as opposed to mechanical failure. Complications such as distal crossovers, delayed distal crossovers, and impending lateral extrusion can be treated with a double distal fixation stitch. This technique addresses stabilization issues and keeps penile implant secure and in place. Objective We demonstrate the Double Distal Fixation Stitch for the meandering distal cylinder Methods 62 y/o white male Hx of erectile dysfunction and Penile implant No significant past medical history Presents with pending left lateral cylinder extrusion Implant functional Patient underwent a corporoplasty and double distal fixation stich in order to ensure distal aspect of cylinder remains in place Results A lateral sub-coronal incision is used on the affected side where cylinder should be positioned. Dissection is carried through the Buck fascia, followed by a transverse incision of the tunica albuginea, where the distal aspect of the affected cylinder is delivered. Two 2-0 Ethibon sutures are threaded through the distal cylinder islet of the implant. A new, properly positioned intracorporal channel is created using a longitudinal capsulotomy and dilation with a 9 Hagar. Two 2-0 Ethibon sutures are passed through the distal islet of the implant cylinder. The first suture is passed through the glans with the cylinder in the native corpora position, a second suture is passed through about .25cm apart from first suture creating a small bridge. A small incision is made connecting the two suture exit sites. Both sutures are then tied down individually leaving one suture on each side to be tied across the bridge. The knots are then buried in the glans by elevating the skin and closing the skin with 3-0 chromic. Conclusions This technique ensured that the cylinder remained in the newly created, appropriately positioned channel. The double distal fixation stitch is safe and effective in securing the distal cylinder of an inflatable penile prosthesis and preventing recurrence. This technique is a useful surgical adjunct to treating patients with prosthetic lateral extrusions or crossovers that can be applied in almost all cases and can ensure distal stabilization of a migrating distal cylinder in weak tunica. Disclosure Any of the authors act as a consultant, employee or shareholder of an industry for: coloplast, boston scientific.

Evaluation of Satisfaction and Outcomes of Patients Who Underwent Two-Piece Inflatable Penile Prosthesis Implantation.

IntroductionThe aim of this study was to evaluate patient and partner satisfaction, device reliability, and complications in patients who underwent two-piece inflatable penile prosthesis (IPP) implantation.Patients and methodsThe data of 22 patients who underwent two-piece inflatable penile prosthesis implantation in our department between 2015 and 2018 were retrospectively analyzed, and a detailed review of all clinical reports was performed. Phone or face-to-face interviews were undertaken to assess the satisfaction rates of the patients and their partners using the modified Erectile Dysfunction Inventory of Treatment Satisfaction (EDITS) questionnaire.ResultsThe mean patient age and partner age were 57.95 ± 6.16 and 58.12 ± 6.66 years, respectively. The mean erectile dysfunction (ED) period was 5.33 ± 2.16 years, and the etiologies of erectile dysfunction were radical pelvic surgery (41%), diabetes mellitus (37%), and vascular disorders (22%). The mean operative time and postoperative hospital stay were 102 ± 29 minutes and 1.8 ± 0.66 days, respectively. Over a mean follow-up period of 29.04 ± 14.48 months, two (9%) cases underwent revision surgery due to mechanical device failure in one and infection in the other. The overall patient and partner satisfaction rates were 73% and 59%, respectively.ConclusionsThe two-piece inflatable penile prosthesis is an effective, reliable, and user-friendly prosthesis with acceptable complication and revision rates and provides a high level of patient and partner satisfaction in selected and fully informed patients.

Technical and Mechanical Problems and Failures of HeartMate II versus HeartMate 3: The Rotterdam Experience

<h3>Purpose</h3> Long-term durability and incidence of potential mechanical device failure (MDF) is a known issue in medical devices. In this study, we investigated the incidence of MDF in continuous flow left ventricular assist device (CF-LVAD) patients comparing Heartmate II versus Heartmate 3. <h3>Methods</h3> We conducted a retrospective study of all CF-LVADs (type HeartMate II en 3) implanted in our center. MDF was defined as a failure of driveline, inflow-outflow graft, electrical power, drive unit, or motor failure, excluding device failure because of a biologic complication (<i>e.g.</i>, device thrombosis, hemolysis, or infections). <h3>Results</h3> A total of 70 CF-LVADs Heartmate II were implanted in 63 patients (median support time 21.4 months [interquartile range (IQR), 8.7 to 34.4 months], mean age 49.6 ± 12.3 years, 73% male) and 101 Heartmate 3 devices were implanted in 101 patients. (median support time 24 months [IQR: 6.6 to 39.8 months], mean age 56.5 ± 10.3 years, 77% male). During follow up in total 24 MDFs occurred in 23 patients (24% in HMII and 8% in HM 3 patients). (log-rank = 0.03) (Figure 1). The main reason for MDF in the Heartmate II was a damaged or fractured driveline (n=8, 42% of MDF's). In 2 patients, sudden death was in all probability related to MDF. The main reason for MDF in the Heartmate 3 was an occluded outflow graft (n=3, 38%). In both Heartmate II and Heartmate 3, a common MDF reason were patients unnecessarily exchanging their system controller at home (n=3, 16%, resp n=2, 25%). Technical problems not resulting in MDF were common in both HM II (n=35, 56% of patients) and Heartmate 3 (n=46, 46%). <h3>Conclusion</h3> Various technical problems are common in patients with ongoing HeartMate II and 3 LVAD support, but mechanical failure occurred significantly less in patients with HeartMate 3. Periodical assessment of the technical integrity of the device remains of uttermost importance during long-term LVAD.

Biocompatibility of the fiberoptic microneedle device chronically implanted in the rat brain

The fiberoptic microneedle device (FMD) is a fused-silica microcatheter capable of co-delivery of fluids and light that has been developed for convection-enhanced delivery and photothermal treatments of glioblastoma. Here we investigate the biocompatibility of FMD fragments chronically implanted in the rat brain in the context of evaluating potential mechanical device failure. Fischer rats underwent craniectomy procedures for sham control (n = 16) or FMD implantation (n = 16) within the brain. Rats were examined daily after implantation, and at 14, 30, 90, and 180 days after implantation were evaluated via computed tomography of the head, hematologic and blood biochemical profiling, and necropsy examinations. Clinical signs of illness and distant implant migration were not observed, and blood analyses were not different between control and FMD implanted groups at any time. Mild inflammatory and astrogliotic reactions localized to the treatment sites within the brain were observed in all groups, more robust in FMD implanted groups compared to controls at days 30 and 90, and decreased in severity over days 90–180 of the study. One rat developed a chronic, superficial surgical site pyogranuloma attributed to the FMD silica implant. Chronically implanted FMD fragments were well tolerated clinically and resulted in anticipated mild, localized brain tissue responses that were comparable with other implanted biomaterials in the brain.

Clinical Outcomes of 3D Printed Titanium Cage Implantation for Foot and Ankle Surgery

CategoryAnkle; TraumaIntroduction/Purpose:Critical Sized Defects (CSD) defined as bone loss greater than 1-2 cm in length or greater than 50% loss in circumference of bone remains a significant challenge in orthopaedic surgery. Patients can acquire these defects through trauma, nonunion post fracture, tumor removal, avascular necrosis, and congenital abnormalities. Custom 3D printed porous Titanium scaffolds are increasingly being used to treat CSD in Foot and Ankle Surgery. Implantation of 3D printed cages is considered a salvage procedure offered after the patient has failed other procedures. Implants fill the space of the defect, provide mechanical strength and provide opportunity for osseous integration. As implementation of this surgical technique is relatively new, further research is needed to assess surgical outcomes and inform future surgical decision making.Methods:This is a retrospective chart review study which examines surgical outcomes after using 3D printed Titanium cages. Patients who received a 3D printed Titanium cage between 1/1/2013 and 11/01/2018 with at least 1 year follow-up were included in this study. Primary outcome is device failure defined as removal of implant for any reason. If applicable, mechanism of failure was recorded for each case. Patient specific factors such as age, gender, race, BMI, diabetes status, Charlson Comorbidity Index, tobacco use, number of foot and ankle surgeries, prior limb infections and laterality of defect were recorded in addition to surgical variables including geometry of implant, duration of surgery, and perioperative antibioticsResults:18 patients who received custom 3D printed Titanium cages were included in this study. Of the 18 patients, 5 patients (27.8%) had device failure, defined as removal of implant. Of the 5 failures, 2 were removed due to infection while the other 3 were removed due to hardware failure including fractured cage, broken screw and loose fixation.Conclusion:Custom 3D printed Titanium was successfully implemented in 72.2% of patients. Implants were only removed due to infection (2 patients) or mechanical failure of device (3 patients). Future studies need to be powered to determine if certain patient specific factors are associated with device failure. Data from this study and subsequent studies can be used to design better implants, decide who is a good surgical candidate, and create preoperative therapies to improve modifiable risk factors

Improving biocompatibility of cobalt based alloy using chemical etching and mechanical treatment

AbstractBiomedical grade of cobalt based alloy have found a plethora of applications as medical devices especially in dental and articulation joints like in total ankle, knee and hip arthroplasty. However, the long‐term performance of this material is highly dependent on their ability to withstand in harsh aqueous environment effects such as corrosion and wear once they are used inside a human body. Loss of surface integrity and subsequent leaching of toxic metal ions as well as particles to the surrounding tissues may undermine biocompatibility of metallic implants, also potentially causing untimely loss of mechanical function and device failure. In this study, a biomedical grade of Co−Cr−Mo alloy surface was treated with various surface modification techniques such as chemical etching and mechanical roughening in order to improve its biocompatibility. Investigation was done to study which surface modification techniques possesses the positive effect in cell growth and exhibit excellent cell response on Co−Cr−Mo alloy. In‐vitro study showed that human osteoblast cells grown with good adherence and spread out with an intimate contact on the chemical treated surface after 14 days of incubation. It is believed that porous structure with grooves owned by chemical treated surface helps in anchoring the cells to the substrate surface and facilitates cells growth since more protein molecules expected to have more sites on this surface. Whilst on mechanical roughened surface, the cells appeared to show slightly less extended cell membranes and the cells remained retarded.

Fracture in drug-eluting stents increases focal intimal hyperplasia in the atherosclerosed rabbit iliac artery.

Drug-eluting stent (DES) strut fracture (SF) is associated with higher incidence of In-stent restenosis (ISR)-return of blockage in a diseased artery post stenting-than seen with bare metal stents (BMS). We hypothesize that concomitance of drug and SF leads to greater neointimal response. Controlled release of therapeutic agents, such as sirolimus and its analogs, or paclitaxel from has reduced tissue based DES failure modes compared to BMS. ISR is dramatically reduced and yet the implications of mechanical device failure is magnified. Bilateral Xience Everolimus-eluting stents (EES) were implanted in 20 New Zealand White rabbits on normal (n = 7) or high fat (HF)/high cholesterol (HC) (n = 13) diets. Implanted stents were intact or mechanically fractured. Everolimus concentration was as packaged or pre-eluted. After 21 days, stented vessels were explanted, resin embedded, MicroCT scanned, and analyzed histomorphometrically. Fractured EES were associated with significant (P < 0.05) increases in arterial stenosis and neointimal formation and lower lumen-to-artery area ratios compared to intact EES. Hyperlipidemic animals receiving pre-eluted EES revealed no significant difference between intact and fracture groups. SF increases intimal hyperplasia, post EES implant, and worse with more advanced disease. Pre-eluted groups, reflective of BMS, did not show significant differences, suggesting a synergistic effect of everolimus and mechanical injury, potentially explaining the lack of SF reports for BMS. Here, we report that ISR has a higher incidence with SF in EES, the clinical implication is that patients with SF after DES implantation merit careful follow-up.

Long-Term Mechanical Durability of Left Ventricular Assist Devices: An Urgent Call for Periodic Assessment of Technical Integrity.

Long-term durability and incidence of potential mechanical device failure (MDF) are largely unknown. In this study, we investigated the incidence and potential predictors of MDF in continuous flow left ventricular assist device (CF-LVAD) patients. We conducted a retrospective study of all CF-LVADs (type HeartMate II) implanted in our center. MDF was defined as a failure of driveline, inflow-outflow graft, electrical power, drive unit, or motor failure, excluding device failure because of a biologic complication (e.g., device thrombosis, hemolysis, or infections). A total of 69 CF-LVADs were implanted in 59 patients (median support time 344 days [interquartile range {IQR}, 149-712 days], mean age 50.1 ± 10.7 years, 75% male). MDF occurred in 9 (13%) CF-LVAD patients at a median follow-up time of 846 (IQR, 708-1337) days after implantation. Freedom of MDF through the first, second, and third year after LVAD implantation was 100%, 85%, and 64%, respectively. Patients who experienced MDF were significantly longer supported by their LVAD (median 846 [IQR, 708-1337] vs 268 [IQR, 103-481] days; p = 0.001) and were more frequently readmitted because of LVAD-related technical problems (p = 0.002), including a higher rate of LVAD controllers exchange (44% vs 12%, respectively; p = 0.03). The main reason for MDF was a damaged or fractured driveline (n=8, 89%). In 2 patients, sudden death was related to MDF. Patients needing extended CF-LVAD support are at increasing risk for MDF. Various technical problems precede the onset of MDF. Periodical extensive assessment of the technical integrity of the device is urgently needed during long-term LVAD support.

(1290) - Unexpected Mechanical Device Failures of Left Ventricular Assist Devices: An Urgent Call for More Intensive Regular Inspections

(1290) - Unexpected Mechanical Device Failures of Left Ventricular Assist Devices: An Urgent Call for More Intensive Regular Inspections

SUDDEN AND FATAL MALFUNCTION AFTER CONTINUOUS-FLOW LEFT VENTRICULAR ASSIST DEVICES: AN URGENT CALL FOR REGULAR INSPECTIONS

Background: Device failure can occur due to mechanical or biological complications. In this study, we investigated the incidence and predictors of Mechanical Device Failure (MDF) in Continuous-Flow Left Ventricular Assist Device (CF-LVAD) patients. Methods: We conducted a retrospective study of all

Mixture of Clustered Bayesian Neural Networks for Modeling Friction Processes at the Nanoscale

Friction and wear are the source of every mechanical device failure, and lubricants are essential for the operation of the devices. These physical phenomena have a complex nature so that no model capable of accurately predicting the behavior of lubricants exists. Thus, lubricants cannot be designed from scratch but have to be screened through expensive trial-error tests. In this study we propose a machine learning (ML) method that infers the relationship between chemical composition of lubricants and their performance from a database. Because no such database of desirable size and completeness is publicly available, we compiled one from molecular dynamics (MD) simulations of toy-model fluids nanoconfined between shearing surfaces. The fluid-friction relation is modeled by a Bayesian neural network (BNN), trained to reproduce the results for a training set of fluids. Due to the inhomogeneous data distribution it was necessary to carefully pick fluids for training and validation from the database with advanced clustering algorithms, rather than using the standard random selection. Different BNNs were then trained on the data clusters and their predictions combined into a mixture of experts. The model provides a prediction of lubricants performance as well as an error bar, at a fraction of the cost of MD. Because most values agree with the actual MD simulations within the estimated error σ, we conclude that the model is satisfactory. This method addresses the challenges brought by noisy, badly distributed, high-dimensional data that are likely to appear in reality as well, and it can be extended to real fluids, if a database could be provided.

Postoperative Complications Associated with rhBMP2 use in Posterior Lumbar Fusion

Introduction The growing number of degenerative conditions in aging population has contributed to the increased rates of lumbar posterior spinal fusion (PLF). While PLF has been shown to be effective for the treatment of various different spinal disorders, variations in surgical technique (such as bone graft used) for PLF have potential for different complication profiles. Human recombinant bone morphogenetic protein 2 (rhBMP2) is a bone graft material commonly used in the US to enhance spinal fusion rates after PLF. There are some reports of complications related to the use of rhBMP-2 in PLF arising from relatively small case series. Aim of our study was to quantify the frequency of various complications in elderly patients undergoing PLF with and without rhBMP2. Material and Methods We queried the orthopaedic subset of the Medicare database (PearlDiver) between 2005 and 2011. Current Procedure Terminology (CPT) codes were used to identify patients undergoing PLF procedures with and without rhBMP2, and International Statistical Classifcation of Diseases 9 (ICD-9) codes were used for complications. Complication and re-operation rates were analyzed within 1 year after the index procedure. Complications included: Acute Renal Failure, Deep Vein Thrombosis, Dural Tear, Hematoma, Heterotopic Ossification, Incision and Drainage, Myocardial Infarction or other cardiac complication, Nerve, Osteolysis, PLF Reoperation, Pneumonia, Pseudoarthrosis, Pulmonary Embolism, Radiculopathy, Respiratory Complications, Sepsis, Urinary Retention, Urinary Tract Infection, Mechanical (failure of other internal orthopedic device, implant, and graft) and Wound Complications. Chi-square analysis was used to calculate the complication differences between the groups. Results There were 20,143 patients who underwent a PLF from 2005–2011, and 27% (5421) of those cases received rhBMP2, while 73% (14722) had the PLF procedure without it. The majority of PLF cases were female (62%) and 65–69 years of age (27%) patients. The overall complication rate was similar between the rhBMP2 and no-rhBMP2 groups, 78.8% and 76.4%, respectively. However, most of the complications had a significantly lower rate in the rhBMP2 group compared with the no-rhBMP2 group (Dural tear 2.2% versus 3%; Incision and Drainage 6.9% vs 7.8%; Myocardial Infraction 3.8% vs 4.4%; Nerve 1.1% vs 2%; Pulmonary Embolism 2.2% vs 2.8%; Radiculopathy 9.4% vs 11.1%; Sepsis 3% vs 3.9%; Wound 8.2% vs 9.6%, respectively). Complications that were in the rhBMP2 group were Mechanical 8% vs 6.2%; Pseudoarthrosis 3% vs 1.8%; Urinary retention 9.9% vs 8.7% ( p &lt; 0.05) and Urinary Tract Infection 30.30% vs 29.60%. Interestingly, heterotopic ossification, demonstrated less than 11 patients in both groups.

MP59-18 SYNCHRONOUS IPSILATERAL HIGH SUBMUSCULAR PLACEMENT OF PROSTHETIC BALLOONS AND RESERVOIRS

You have accessJournal of UrologyTrauma/Reconstruction/Diversion: External Genitalia Reconstruction and Urotrauma1 Apr 2016MP59-18 SYNCHRONOUS IPSILATERAL HIGH SUBMUSCULAR PLACEMENT OF PROSTHETIC BALLOONS AND RESERVOIRS Nicholas Kavoussi, Ryan Mooney, Jeremy Scott, Billy Cordon, Matthias Hofer, and Allen Morey Nicholas KavoussiNicholas Kavoussi More articles by this author , Ryan MooneyRyan Mooney More articles by this author , Jeremy ScottJeremy Scott More articles by this author , Billy CordonBilly Cordon More articles by this author , Matthias HoferMatthias Hofer More articles by this author , and Allen MoreyAllen Morey More articles by this author View All Author Informationhttps://doi.org/10.1016/j.juro.2016.02.837AboutPDF ToolsAdd to favoritesDownload CitationsTrack CitationsPermissionsReprints ShareFacebookTwitterLinked InEmail INTRODUCTION AND OBJECTIVES Synchronous ipsilateral placement of artificial urinary sphincter (AUS) pressure regulating balloons (PRB) and inflatable penile prosthesis (IPP) reservoirs in a single submuscular tunnel is a novel strategy which may be advantageous for prosthetic urology patients who have had previous major pelvic surgery. We report our initial experience with ipsilateral versus bilateral placement of the AUS PRBs and IPP reservoirs in men having synchronous implant surgery. METHODS We retrospectively reviewed all patients having synchronous AUS and IPP placement from 2007-2015 by the senior author at our tertiary center. Patients were grouped according to the whether they had ipsilateral versus contralateral placement of the AUS PRB and IPP reservoir. Among the 47 patients who underwent synchronous AUS/IPP implantation during the study period, we compared the reoperation rates due to infectious/erosive complications or mechanical failure in each group. The Fisher's exact test was used for all comparisons. RESULTS Among the 968 men who underwent implant surgery during the study period, we identified 47 who having synchronous device placement, 17 of whom (36%) underwent ipsilateral placement of the PRB/reservoir. With a median follow up of 24 months (range 3-73 months), reoperations were necessary in 12/47 (26%) and were similar between groups (ipsilateral: 5/17, 29%; bilateral: 7/30, 23%; p=0.73). Indications for reoperation included mechanical device failure in 5/47 (ipsilateral: 1/17, 6%; bilateral: 4/30, 13%; p=0.56) devices, cuff erosion in 4/47 (ipsilateral: 1/17, 6%; bilateral: 3/30, 10%; p=0.99), and infections in 3/47 (ipsilateral: 2/17, 12%; bilateral: 1/30, 3.3%; p=0.54). Nearly all reoperation patients (11/12, 92%) had compromised urethras, defined by prior implant or urethral surgery (7/12, 58%) or radiation (4/12, 33%). CONCLUSIONS Synchronous ipsilateral high submuscular placement of urologic prosthetic balloons and reservoirs can be done without an increase in infectious/erosive complications or device failure. © 2016FiguresReferencesRelatedDetails Volume 195Issue 4SApril 2016Page: e791-e792 Advertisement Copyright & Permissions© 2016MetricsAuthor Information Nicholas Kavoussi More articles by this author Ryan Mooney More articles by this author Jeremy Scott More articles by this author Billy Cordon More articles by this author Matthias Hofer More articles by this author Allen Morey More articles by this author Expand All Advertisement Advertisement PDF downloadLoading ...

Surgical Energy-Based Device Injuries and Fatalities Reported to the Food and Drug Administration

Energy-based devices are used in virtually every operation. Our purposes were to describe causes of energy-based device complications leading to injury or death, and to determine if common mechanisms leading to injury or death can be identified. The FDA's Manufacturer and User Facility Device Experience (MAUDE) database was searched for surgical energy-based device injuries and deaths reported over 20 years (January 1994 to December 2013). Device-related complications were recorded and analyzed. We analyzed 178 deaths and 3,553 injuries. Common patterns of complications were: thermal burns, 63% (n = 2,353); hemorrhage, 17% (n = 642); mechanical failure of device, 12% (n = 442); and fire, 8% (n = 294). Events were identified intraoperatively in 82% (3,056), inpatient postoperatively in 9% (n = 351), and after discharge in 9% (n = 324). Of the deaths, 12% (n = 22) occurred after discharge home. Common mechanisms for thermal burn injuries were: direct application, 30% (n = 694); dispersive electrode burn, 29% (n = 657); and insulation failure, 14% (n = 324). Thermal injury was the most common reason for death (39%, n = 70). The mechanism for these thermal injuries was most frequently direct application (84%, n = 59, p < 0.001 vs all other mechanisms). Fires were most common with monopolar "Bovie" instruments (88%, n = 258, p < 0.001 vs all other devices) when they were used in head and neck operations (66%, n = 193, p < 0.001 vs all other locations). Complications due to energy-based devices occur from 4 main causes: thermal burn, hemorrhage, mechanical failure, and fire. Thermal direct application injuries are the most common reason for both injury and death.

Outcomes and Costs of Reverse Shoulder Arthroplasty in the Morbidly Obese: A Case Control Study.

The rising number of morbidly obese patients has important consequences for the health-care system. We investigated the effect of morbid obesity on outcomes, complications, discharge disposition, and costs in patients undergoing reverse shoulder arthroplasty. Our joint registry was searched for all patients who had undergone primary reverse shoulder arthroplasty for a reason other than fracture from 2003 to 2010 and had a minimum of twenty-four months of follow-up. Twenty-one patients with a body mass index (BMI) of ≥40 kg/m2 were identified (follow-up, 45 ± 16 months; sex, seventeen female and four male; age, 69 ± 7 years) and were compared with sixty-three matched control patients with a BMI of <30 kg/m2 (follow-up, 48 ± 20 months; sex, fifty female and thirteen male; age, 71 ± 6 years) after an a priori sample size calculation. Outcome instrument data were obtained preoperatively and postoperatively. The Charlson-Deyo comorbidity index (CDI) score, total comorbidities, operative time, blood loss, duration of hospital stay, discharge disposition, costs, and complications were recorded. Compared with nonobese patients, morbidly obese patients had similar improvements in functional outcomes (e.g., American Shoulder and Elbow Surgeons score, 32 to 69 compared with 40 to 78) and in shoulder motion (e.g., forward flexion, 61° to 140° compared with 74° to 153°); all improvements were significant (p < 0.05). Morbidly obese patients had a similar rate of scapular notching (odds ratio [OR] = 0.58, p = 0.63), more total comorbidities excluding obesity (six compared with four, p = 0.001), a higher CDI (2 compared with 1, p = 0.025), and a higher rate of obstructive sleep apnea (OR = 27.7, p = 0.0001). Their operative time was thirteen minutes longer (p = 0.014) and their blood loss was 40 mL greater (p = 0.008). Morbidly obese patients had a similar duration of stay (3.1 compared with 2.6 days, p = 0.823) and hospital readmission rate (OR = 16.3, p = 0.08) but a sixfold higher rate of discharge to rehabilitation facilities rather than to home (OR = 8, p < 0.0001). Hospital costs were higher by $2974 (p = 0.009). The rates of major complications (n = 4 compared with 8, p = 0.479) and of minor complications (n = 3 compared with 14, p = 0.440) were similar. No intraoperative complications or mechanical device failures were noted in either group. Reverse shoulder arthroplasty appears to be as safe and effective in morbidly obese patients, although it has an increased cost and patients have a lower rate of discharge to home and greater care needs after discharge. Prognostic Level III. See Instructions for Authors for a complete description of levels of evidence.

Complications of the Intramedullary Skeletal Kinetic Distractor (ISKD) in Distraction Osteogenesis

The Intramedullary Skeletal Kinetic Distractor (ISKD) (Orthofix Inc, Lewisville, TX, USA) is an intramedullary device designed for more comfortable limb lengthening than that with external fixators; lengthening is achieved with this nail using rotational oscillation between two telescoping sections. However, the degree to which this device achieves this goal and its complication rate have not been fully documented. We determined (1) the frequency with which distraction was not achieved at the desired rate, (2) whether pain differed between patients with normally and abnormally distracting nails, (3) risk factors for abnormal nails, and (4) other complications. We analyzed 35 lengthening segments (26 femurs, nine tibias) in 19 patients. Mean length achieved was 47mm. Femoral nails were categorized into four groups according to distraction rate: normal, runaway (unintentionally faster rate [>1.5mm/day]), difficult-to-distract (slower rate [<0.8mm/day] requiring manual manipulation but not requiring general anesthesia), and nondistracting (slower rate [<0.8mm/day] requiring manual manipulation under general anesthesia or reosteotomy). Possible risk factors, including age, BMI, preoperative thigh circumferences, degree of intramedullary overreaming, and length of the thicker portion of the nail within the distal fragment, were compared among groups. VAS pain scores were compared among groups under three conditions: rest, physiotherapy, and distraction motion. Complications were also analyzed. Minimum followup was 15months (mean, 26months; range, 15-38months) after first-stage surgery. Abnormal distraction rate was observed in 21 of 35 segments (60%; 17 femurs, four tibias). VAS pain scores showed no differences among groups during rest or physiotherapy but were higher (p=0.02) in the problematic nails (7-8 points) versus normal nails (3 points) during distraction. Only mean length of the thicker portion of the nail within the distal fragment differed between normally and abnormally distracting nails (95mm versus 100mm; p=0.03), although this was unlikely to be clinically important. Complications occurred in 10 patients (53%), including five with decreased ankle ROM during distraction, four with delayed bone healing, and one with mechanical device failure during distraction. Rate control was difficult to achieve with the ISKD nail for femoral and tibial lengthenings, complications were relatively common, and among patients in whom rate control was not achieved, pain levels were high. Based on our findings, we believe that surgeons should avoid use of this nail. Level IV, therapeutic study. See Instructions for Authors for a complete description of levels of evidence.

Reoperation After Sacral Neuromodulation Therapy

Sacral neuromodulation has become an accepted treatment for various types of lower urinary tract dysfunction. However, despite technologic advances in device implantation and a trial stimulation period, sacral neuromodulation still has a significant reoperation rate. We report our single-institution experience of reoperation rates. We performed a retrospective review of our patients who had undergone the implantation of the InterStim device from April 1999 to December 2011 for lower urinary tract dysfunction. A total of 155 InterStim devices were implanted by 2 surgeons. Of the 142 patients with complete follow-up, 55 (38.2%) patients required reoperation, for either revision or explantation of the device. Revisions were performed in 30 (21.1%) patients, most commonly for mechanical failure of device, battery end-of-service, and pain, either at the site of the implanted pulse generator or with stimulation. Of the 30 patients who underwent revision, 14 had successful results, 6 had persistent symptoms, and 10 progressed to eventual explantation.The overall explantation rate was 24.6% (35 of 142 patients), and the average time to removal was 44 months. Most of the explantations were performed for poor symptom control and failure to maintain response (74.3%).Reoperation was not associated with age, sex, obesity, diabetes, chronic pain, use of the tined lead, or type of lower urinary tract dysfunction. Sacral neuromodulation has a substantial revision and explantation rate, without any clear predictors for these complications. Patients should be counseled to these complications before surgery.

DuraHeart&lt;sup&gt;TM&lt;/sup&gt; Magnetically Levitated Left Ventricular Assist Device

The DuraHeart left ventricular assist device (LVAD) is the world's first approved magnetically levitated implantable centrifugal pump. We report our initial experience with the DuraHeart as a bridge to heart transplantation. Between 2008 and 2011, 23 patients (17 males; mean age 35 years, range 16-53 years) with endstage heart failure underwent implantation with the DuraHeart LVAD at Osaka University Hospital. Of those, 7 underwent conversion surgery from a Nipro paracorporeal LVAD to the DuraHeart. There were no deaths during the mean support period of 559±241 days (176-999 days). In total, 17 patients (74%) remain with the LVAD and 5 (22%) underwent heart transplantation after 580±302 days (176-982 days) of support. Major adverse events included 8 (34%) driveline/pocket infections, 4 (17%) cerebrovascular accidents, 4 (17%) right heart failures requiring mechanical support, and 3 (13%) mechanical device failures (magnetic levitation failure caused by driveline fracture). Of the 5 patients who developed pump pocket infection, 3 underwent previous conversion surgery from the Nipro LVAD. Our initial experience with the DuraHeart LVAD in Japan demonstrated excellent long-term survival with acceptable rates of adverse events. With refinement of the system, including mechanical durability, this pump will further enhance the quality of life for patients who require long-term mechanical circulatory support.

Clinical Experience With HeartWare Left Ventricular Assist Device in Patients With End-Stage Heart Failure

The gold standard treatment for end-stage heart failure is cardiac transplantation. Because of the increasing number of heart failure patients and the limited supply of donor hearts, a ventricular assist device (VAD) is used as a bridge to transplantation, recovery, or decision. Newer generation VADs have lower risk of fatal adverse events and are also smaller in size. We present our experience with the intrapericardial HeartWare VAD (HeartWare, Framingham, MA) and its clinical outcome. The clinical outcome of HeartWare VAD implantations for end-stage heart failure patients performed at Harefield Hospital from March 2007 to June 2011 was studied. The study design was a retrospective review of the prospectively collected data. Thirty-four patients with a mean age of 51±10 years were included in this study. Twenty-nine patients were male (85%). The mean duration of mechanical support was 261±64 days. Five patients (15%) were successfully bridged to heart transplantation. The overall mortality was 24% (8 patients). There were 1 case of mechanical device failure (2%) and 3 cases of device failure due to thrombus formation (8%). Postoperative complications included 5 reoperations for bleeding (15%), 12 acute renal failures (36%), 7 respiratory failures (21%), 2 hepatic dysfunctions (6%), 3 neurologic dysfunctions (9%), 7 right-side heart failures (21%), and 5 driveline infections (15%). Although cardiac transplantation remains the gold standard for treatment of end-stage heart failure patients, the HeartWare VAD can be used as a safe alternative with a satisfactory clinical outcome.