Topographical control of cells

We review the literature on the reaction of cells to their surrounding topography. The topography may be that of surrounding cells, intercellular materials or biomaterials. The reactions include cell orientation, rates of movement, and activations of the cells. We concentrate on those papers where quantitative measurements of the reactions have been made and largely ignore those on subjective impressions. A wide range of topographies are considered but special attention is given to results on groove-ridge topographies. The question of whether the cells are reacting to the topography directly or to patterned substratum chemistry formed on the topography is discussed. The review ends with a summary of the types of prosthesis where advantage has been taken of the ability to fabricate topography.

Percutaneous left atrial appendage closure vs warfarin for atrial fibrillation: a randomized clinical trial

IMPORTANCE

While effective in preventing stroke in patients with atrial fibrillation (AF), warfarin is limited by a narrow therapeutic profile, a need for lifelong coagulation monitoring, and multiple drug and diet interactions.

OBJECTIVE

To determine whether a local strategy of mechanical left atrial appendage (LAA) closure was noninferior to warfarin.

DESIGN, SETTING, AND PARTICIPANTS

PROTECT AF was a multicenter, randomized (2:1), unblinded, Bayesian-designed study conducted at 59 hospitals of 707 patients with nonvalvular AF and at least 1 additional stroke risk factor (CHADS2 score ≥1). Enrollment occurred between February 2005 and June 2008 and included 4-year follow-up through October 2012. Noninferiority required a posterior probability greater than 97.5% and superiority a probability of 95% or greater; the noninferiority margin was a rate ratio of 2.0 comparing event rates between treatment groups.

INTERVENTIONS

Left atrial appendage closure with the device (n = 463) or warfarin (n = 244; target international normalized ratio, 2-3).

MAIN OUTCOMES AND MEASURES

A composite efficacy end point including stroke, systemic embolism, and cardiovascular/unexplained death, analyzed by intention-to-treat.

RESULTS

At a mean (SD) follow-up of 3.8 (1.7) years (2621 patient-years), there were 39 events among 463 patients (8.4%) in the device group for a primary event rate of 2.3 events per 100 patient-years, compared with 34 events among 244 patients (13.9%) for a primary event rate of 3.8 events per 100 patient-years with warfarin (rate ratio, 0.60; 95% credible interval, 0.41-1.05), meeting prespecified criteria for both noninferiority (posterior probability, >99.9%) and superiority (posterior probability, 96.0%). Patients in the device group demonstrated lower rates of both cardiovascular mortality (1.0 events per 100 patient-years for the device group [17/463 patients, 3.7%] vs 2.4 events per 100 patient-years with warfarin [22/244 patients, 9.0%]; hazard ratio [HR], 0.40; 95% CI, 0.21-0.75; P = .005) and all-cause mortality (3.2 events per 100 patient-years for the device group [57/466 patients, 12.3%] vs 4.8 events per 100 patient-years with warfarin [44/244 patients, 18.0%]; HR, 0.66; 95% CI, 0.45-0.98; P = .04).

CONCLUSIONS AND RELEVANCE

After 3.8 years of follow-up among patients with nonvalvular AF at elevated risk for stroke, percutaneous LAA closure met criteria for both noninferiority and superiority, compared with warfarin, for preventing the combined outcome of stroke, systemic embolism, and cardiovascular death, as well as superiority for cardiovascular and all-cause mortality.

TRIAL REGISTRATION

clinicaltrials.gov Identifier: NCT00129545.

Macrophage phenotype and remodeling outcomes in response to biologic scaffolds with and without a cellular component

Recently, macrophages have been characterized as having an M1 or M2 phenotype based on receptor expression, cytokine and effector molecule production, and function. The effects of macrophage phenotype upon tissue remodeling following the implantation of a biomaterial are largely unknown. The objectives of this study were to determine the effects of a cellular component within an implanted extracellular matrix (ECM) scaffold upon macrophage phenotype, and to determine the relationship between macrophage phenotype and tissue remodeling. Partial-thickness defects in the abdominal wall musculature of Sprague-Dawley rats were repaired with autologous body wall tissue, acellular allogeneic rat body wall ECM, xenogeneic pig urinary bladder tissue, or acellular xenogeneic pig urinary bladder ECM. At 3, 7, 14, and 28 days the host tissue response was characterized using histologic, immunohistochemical, and RT-PCR methods. The acellular test articles were shown to elicit a predominantly M2 type response and resulted in constructive remodeling, while those containing a cellular component, even an autologous cellular component, elicited a predominantly M1 type response and resulted in deposition of dense connective tissue and/or scarring. We conclude that the presence of cellular material within an ECM scaffold modulates the phenotype of the macrophages participating in the host response following implantation, and that the phenotype of the macrophages participating in the host response appears to be related to tissue remodeling outcome.

Long-term complications associated with prosthetic repair of incisional hernias

OBJECTIVE

To determine whether the type of prosthetic material and technique of placement influenced long-term complications after repair of incisional hernias.

DESIGN

Retrospective cohort analytic study.

SETTING

University-affiliated hospital.

PATIENTS

Two hundred patients undergoing open repair of abdominal incisional hernias with prosthetic material between 1985 and 1994.

INTERVENTIONS

Four types of prosthetic material were used and placed either as an onlay, underlay, sandwich, or finger interdigitation technique. The materials were monofilamented polypropylene mesh (Marlex, Davol Inc, Cranston, RI), double-filamented mesh (Prolene, Ethicon Inc, Somerville, NJ), expanded polytetrafluroethylene patch (Gore-Tex, WL Gore & Associates, Phoenix, Ariz) or multifilamented polyester mesh (Mersilene, Ethicon Inc).

MAIN OUTCOME MEASURES

The incidence of recurrence and complications such as enterocutaneous fistula, bowel obstruction, and infection with each type of material and technique of repair were compared with univariate and multivariate analysis.

RESULTS

On univariate analysis, multifilamented polyester mesh had a significantly higher mean number of complications per patient (4.7 vs 1.4-2.3; P<.002), a higher incidence of fistula formation (16% vs 0%-2%; P<.001), a greater number of infections (16% vs 0%-6%; P<.05), and more recurrent hernias (34% vs 10%-14%; P<.05) than the other materials used. The additional mean length of stay to treat complications was also significantly longer (30 vs 3-7 days; P<.001) when polyester mesh was used. The deleterious effect of polyester mesh on long-term complications was confirmed on multiple logistic regression (P=.002). The technique of placement had no influence on outcome.

CONCLUSION

Polyester mesh should no longer be used for incisional hernia repair.

Corneal transplantation

Corneal transplantation or keratoplasty has developed rapidly in the past 10 years. Penetrating keratoplasty, a procedure consisting of full-thickness replacement of the cornea, has been the dominant procedure for more than half a century, and successfully caters to most causes of corneal blindness. The adoption by specialist surgeons of newer forms of lamellar transplantation surgery, which selectively replace only diseased layers of the cornea, has been a fundamental change in recent years. Deep anterior lamellar keratoplasty is replacing penetrating keratoplasty for disorders affecting the corneal stromal layers, while eliminating the risk of endothelial rejection. Endothelial keratoplasty, which selectively replaces the corneal endothelium in patients with endothelial disease, has resulted in more rapid and predictable visual outcomes. Other emerging therapies are ocular surface reconstruction and artificial cornea (keratoprosthesis) surgery, which have become more widely available because of rapid advances in these techniques. Collectively, these advances have resulted in improved outcomes, and have expanded the number of cases of corneal blindness, which can now be treated successfully. Femtosecond-laser-assisted surgery, bioengineered corneas, and medical treatment for endothelial disease are also likely to play a part in the future.

Brain responses to micro-machined silicon devices

Micro-machined neural prosthetic devices can be designed and fabricated to permit recording and stimulation of specific sites in the nervous system. Unfortunately, the long-term use of these devices is compromised by cellular encapsulation. The goals of this study were to determine if device size, surface characteristics, or insertion method affected this response. Devices with two general designs were used. One group had chisel-shaped tips, sharp angular corners, and surface irregularities on the micrometer size scale. The second group had rounded corners, and smooth surfaces. Devices of the first group were inserted using a microprocessor-controlled inserter. Devices of the second group were inserted by hand. Comparisons were made of responses to the larger devices in the first group with devices from the second group. Responses were assessed 1 day and 1, 2, 4, 6, and 12 weeks after insertions. Tissues were immunochemically labeled for glial fibrillary acidic protein (GFAP) or vimentin to identify astrocytes, or for ED1 to identify microglia. For the second comparison devices from the first group with different cross-sectional areas were analyzed. Similar reactive responses were observed following insertion of all devices; however, the volume of tissue involved at early times, <1 week, was proportional to the cross-sectional area of the devices. Responses observed after 4 weeks were similar for all devices. Thus, the continued presence of devices promotes formation of a sheath composed partly of reactive astrocytes and microglia. Both GFAP-positive and -negative cells were adherent to all devices. These data indicate that device insertion promotes two responses-an early response that is proportional to device size and a sustained response that is independent of device size, geometry, and surface roughness. The early response may be associated with the amount of damage generated during insertion. The sustained response is more likely due to tissue-device interactions.

Nitinol stent implantation versus balloon angioplasty for lesions in the superficial femoral artery and proximal popliteal artery: twelve-month results from the RESILIENT randomized trial

BACKGROUND

Controversy still exists regarding the best endovascular treatment strategy for patients with symptomatic disease of the superficial femoral artery. There are conflicting data regarding the benefits of superficial femoral artery stenting and the role of primary stenting compared with balloon angioplasty with provisional stent implantation.

METHODS AND RESULTS

A total of 206 patients from 24 centers in the United States and Europe with obstructive lesions of the superficial femoral artery and proximal popliteal artery and intermittent claudication were randomized to implantation of nitinol stents or percutaneous transluminal angioplasty. The mean total lesion length was 71 mm for the stent group and 64 mm for the angioplasty group. Acute lesion success (<30%residual stenosis) was superior for the stent group compared with the angioplasty group (95.8% versus 83.9%; P<0.01). Twenty-nine (40.3%) patients in the angioplasty group underwent bailout stenting because of a suboptimal angiographic result or flow-limiting dissection. Bailout stenting was treated as a target lesion revascularization and loss of primary patency in the final analysis. At 12 months, freedom from target lesion revascularization was 87.3% for the stent group compared with 45.1% for the angioplasty group (P<0.0001). Duplex ultrasound-derived primary patency at 12 months was better for the stent group (81.3% versus 36.7%; P<0.0001). Through 12 months, fractures occurred in 3.1% of stents implanted. No stent fractures resulted in loss of patency or target lesion revascularization.

CONCLUSIONS

In this multicenter trial, primary implantation of a self-expanding nitinol stent for moderate-length lesions in the superficial femoral artery and proximal popliteal artery was associated with better acute angiographic results and improved patency compared with balloon angioplasty alone.

CLINICAL TRIAL REGISTRATION

URL: http://www.clinicaltrials.gov. Unique identifier: NCT00673985.

Evaluation of the biocompatibility of a chitosan scaffold in mice

Chitosan scaffolds appear to be suitable for a variety of tissue engineering applications. This study addressed the biocompatibility of chitosan in a mouse implantation model. Porous chitosan scaffolds were implanted in mice, and animals were sacrificed after 1, 2, 4, 8, or 12 weeks. Macroscopic inspection of the implantation site revealed no pathological inflammatory responses. Histological assessment indicated marked neutrophil accumulation within the implant, which resolved with increasing implantation time. Gram staining and limulus assays revealed no evidence of infection or endotoxin. Collagen was observed within the chitosan pore spaces, indicating that connective tissue matrix was deposited within the implant. Angiogenic activity associated with the external implant surface was also observed. Cellular immune responses were determined by lymphocyte proliferation assays, and antibody responses were measured using ELISA techniques. These assays indicated a very low incidence of chitosan-specific reactions. Although there was a large migration of neutrophils into the implantation area, there were minimal signs of any inflammatory reaction to the material itself. This preliminary study demonstrates that chitosan has a high degree of biocompatibility in this animal model. Overall, the findings suggest that chitosan may be suitable for the development of implantable materials.

The Reverse Shoulder Prosthesis for glenohumeral arthritis associated with severe rotator cuff deficiency. A minimum two-year follow-up study of sixty patients

BACKGROUND

Patients who have pain and dysfunction from glenohumeral arthritis associated with severe rotator cuff deficiency have few treatment options. The goal of this study was to retrospectively evaluate the short-term results of arthroplasty with use of the Reverse Shoulder Prosthesis in the management of this problem.

METHODS

We report the results for sixty patients (sixty shoulders) with a rotator cuff deficiency and glenohumeral arthritis who were followed for a minimum of two years. Thirty-five patients had no previous shoulder surgery, whereas twenty-three had had either an open or arthroscopic rotator cuff repair, one had had a subacromial decompression, and one had had a biceps tendon repair. All patients were assessed preoperatively and postoperatively with the American Shoulder and Elbow Surgeons scoring system for pain and function and with visual analog scales for pain and function. They were also asked to rate their satisfaction with the outcome. The shoulder range of motion was measured preoperatively and postoperatively.

RESULTS

The average age of the patients was seventy-one years. The average duration of follow-up was thirty-three months. All measures improved significantly (p < 0.0001). The mean total score on the American Shoulder and Elbow Surgeons system improved from 34.3 to 68.2; the mean function score, from 16.1 to 29.4; and the mean pain score, from 18.2 to 38.7. The score for function on the visual analog scale improved from 2.7 to 6.0, and the score for pain on the visual analog scale improved from 6.3 to 2.2. Forward flexion increased from 55.0 degrees to 105.1 degrees, and abduction increased from 41.4 degrees to 101.8 degrees. Forty-one of the sixty patients rated the outcome as good or excellent; sixteen were satisfied, and three were dissatisfied. There were a total of thirteen complications in ten patients (17%). Seven patients (12%) had eight failures, requiring revision surgery to another Reverse Shoulder Prosthesis in five patients (one shoulder had two revisions) and revision to a hemiarthroplasty in two patients because of deep infection.

CONCLUSIONS

The data from this study suggest that arthroplasty with the Reverse Shoulder Prosthesis may be a viable treatment for patients with glenohumeral arthritis and a massive rotator cuff tear. However, future studies will be necessary to determine the longevity of the implant and whether it will provide continued improvement in function.

United States Food and Drug Administration clinical trial of the Implantable Collamer Lens (ICL) for moderate to high myopia

PURPOSE

To report on 3-year postoperative safety and efficacy outcomes with the Myopic Implantable Collamer Lens (ICL).

DESIGN

Prospective nonrandomized clinical trial.

PARTICIPANTS

Five hundred twenty-six eyes of 294 patients with between 3.0 and 20.0 diopters (D) of myopia participating in the United States Food and Drug Administration clinical trial of the ICL for myopia.

INTERVENTION

Implantation of the ICL.

MAIN OUTCOME MEASURES

Uncorrected visual acuity (VA), refraction, best spectacle-corrected VA (BSCVA), adverse events, operative and postoperative complications, lens opacity analysis, subjective satisfaction, and patient symptoms.

RESULTS

At 3 years, 59.3% had 20/20 or better VA, and 94.7% had 20/40 or better uncorrected VA if BSCVA was 20/20 and patients were targeted for emmetropia; 67.5% of patients were within 0.5 D and 88.2% were within 1.0 D of predicted refraction. The mean improvement in BSCVA ranged between 0.5 and 0.6 lines. At 3 years postoperatively, 3 eyes (0.8%) decreased by >or=2 lines of BSCVA, in contrast to 40 eyes (10.8%) that improved by a similar amount. Contrast sensitivity improved postoperatively. Cumulative 3-year corneal endothelial cell loss was under 10%. Early largely asymptomatic, presumably surgically induced anterior subcapsular opacities (trace or greater) were seen in 14 eyes (2.7%), with only 2 being clinically significant. Five eyes (0.9%) of 3 patients developed nuclear opacities of grade >2 at 2 to 3 years postoperatively. Three (0.6%) ICL removals with cataract extraction and IOL implantation have been performed. Only 0.6% reported dissatisfaction; 97.1% of patients reported they would choose ICL implantation again. Incidences of patient symptoms, glare, halos, double vision, night vision problems, and night driving difficulties decreased or remained unchanged after ICL surgery.

CONCLUSION

Three-year results from this standardized, multicenter clinical investigation support the safety, efficacy, and predictability of ICL surgery to treat moderate to high myopic refractive errors.

Vagus nerve stimulation

Left vagus nerve stimulation (VNS) is a promising new treatment for epilepsy. In 1997, VNS was approved in the United States as an adjunctive treatment for medically refractory partial-onset seizures in adults and adolescents. For some patients with partial-onset seizures, the adverse effects of antiepileptic drugs (AEDs) are intolerable; for others, no single AED or combination of anticonvulsant agents is effective. Cerebral resective surgery is an option to pharmacotherapy in some cases, but many patients with partial-onset seizures are not optimal candidates for intracranial surgery. VNS entails implantation of a programmable signal generator--the Neuro-cybernetic Prosthesis (NCP)--in the chest cavity. The stimulating electrodes of the NCP carry electrical signals from the generator to the left vagus nerve. Although the mechanism of action of VNS is not known, controlled studies have shown that it is safe and well-tolerated by patients with long-standing partial-onset epilepsy. Side effects, which are generally of mild to moderate severity, almost always disappear after the stimulation settings are adjusted. Encouraging results have also been reported in pediatric patients.

The Artificial Silicon Retina Microchip for the Treatment of VisionLoss From Retinitis Pigmentosa

OBJECTIVE

To determine the safety and efficacy of the artificial silicon retina (ASR) microchip implanted in the subretinal space to treat vision loss from retinitis pigmentosa.

METHODS

The ASR microchip is a 2-mm-diameter silicon-based device that contains approximately 5000 microelectrode-tipped microphotodiodes and is powered by incident light. The right eyes of 6 patients with retinitis pigmentosa were implanted with the ASR microchip while the left eyes served as controls. Safety and visual function information was collected.

RESULTS

During follow-up that ranged from 6 to 18 months, all ASRs functioned electrically. No patient showed signs of implant rejection, infection, inflammation, erosion, neovascularization, retinal detachment, or migration. Visual function improvements occurred in all patients and included unexpected improvements in retinal areas distant from the implant.

MAIN OUTCOME MEASURES

Subjective improvements included improved perception of brightness, contrast, color, movement, shape, resolution, and visual field size.

CONCLUSIONS

No significant safety-related adverse effects were observed. The observation of retinal visual improvement in areas far from the implant site suggests a possible generalized neurotrophic-type rescue effect on the damaged retina caused by the presence of the ASR. A larger clinical trial is indicated to further evaluate the safety and efficacy of a subretinally implanted ASR.

A classification system and algorithm for reconstruction of maxillectomy and midfacial defects

Maxillectomy defects become more complex when critical structures such as the orbit, globe, and cranial base are resected, and reconstruction with distant tissues becomes essential. This study reviews all maxillectomy defects reconstructed immediately using pedicled and free flaps to establish (1) a classification system and (2) an algorithm for reconstruction of these complex problems. Over a 5-year period, 60 flaps were used to reconstruct defects classified as the following: type I, limited maxillectomy (n = 7); type II, subtotal maxillectomy (n = 10); type IIIa, total maxillectomy with preservation of the orbital contents (n = 13); type IIIb, total maxillectomy with orbital exenteration (n = 18); and type IV, orbitomaxillectomy (n = 10). Free flaps (45 rectus abdominis and 10 radial forearm) were used in 55 patients (91.7 percent), and the temporalis muscle was transposed in five elderly patients who were not free-flap candidates. Vascularized (radial forearm osteocutaneous) bone flaps were used in four of the 60 patients (6.7 percent) and nonvascularized bone grafts in 17 (28.3 percent). Simultaneous reconstruction of the oral commissure using an Estandler procedure was performed in 10 patients with maxillectomy and through-and-through soft-tissue defects. Free-flap survival was 100 percent, with reexploration in five of 55 patients (9.1 percent) and partial-flap necrosis in one patient. Seven of the 60 patients (11.7 percent) had systemic complications, and four died within 30 days of hospitalization. Fifty patients had more than 6 months of follow-up with a mean time of 27.7 (+/- 15.6) months. Postoperative radiotherapy was administered in 32 of these patients (64.0 percent). Chewing and speech functions were assessed in 36 patients with type II, IIIa, and IIIb defects. A prosthetic denture was fixed in 15 of 36 patients (41.7 percent). Return to an unrestricted diet was seen in 16 patients (44.4 percent), a soft diet in 17 (47.2 percent), and a liquid diet in three (8.3 percent). Speech was assessed as normal in 14 of 36 patients (38.9 percent), near normal in 15 (41.7 percent), intelligible in six (16.7 percent), and unintelligible in one patient (2.8 percent). Globe and periorbital soft-tissue position was assessed in 14 patients with type I and IIIa defects. There were no cases of enophthalmos, and one patient had a mild vertical dystopia. Ectropion was observed in 10 of 14 patients (71.4 percent). Oral competence was considered good in all 10 patients with excision/reconstruction of the oral commissure; however, two patients (20 percent) developed microstomia after receiving radiotherapy. Aesthetic results were evaluated at least 6 months after reconstruction in 50 patients. They were good to excellent in 29 patients (58 percent) for whom cheek skin and lip were not resected, and poor to fair (42 percent) when the external skin or orbital contents were excised. Secondary procedures were required in 16 of 50 patients (32.0 percent). Free-tissue transfer provides the most effective and reliable form of immediate reconstruction for complex maxillectomy defects. The rectus abdominis and radial forearm flaps in combination with immediate bone grafting or as osteocutaneous flaps reliably provide the best aesthetic and functional results. An algorithm based on the type of maxillary resection can be followed to determine the best approach to reconstruction.

13 years of experience with artificial urinary sphincter implantation at Baylor College of Medicine

PURPOSE

We reviewed 13 years of experience with artificial urinary sphincter implantation (narrow backed cuff) at a single institution.

MATERIALS AND METHODS

Between 1992 and 2005, 270 patients underwent artificial urinary sphincter implantation, as performed by a single surgeon at Baylor College of Medicine, and followup data were available on 218 of them. Mean followup was 36.5 months (maximum 151.4). Of the 218 patients 60 underwent prostatectomy and pelvic radiation, 116 underwent prostatectomy without radiotherapy, 11 had neurogenic bladder and 31 underwent secondary artificial urinary sphincter implantation.

RESULTS

The complication rate did not differ among the 4 treatment groups. Complication rates were infection in 5.5% of cases, erosion in 6.0%, urethral atrophy in 9.6%, mechanical failure in 6.0% and surgical removal or revision in 27.1%. Median time to complications was 3.7 months for infection, 19.8 months for erosion, 29.6 months for atrophy, 68.1 months for failure and 14.4 months for surgery. At 5 years 75% of patients were free from revision or removal. A history of failed injectable or male sling, or of Valsalva voiding did not adversely impact the outcome. The rate of bladder neck contracture was high in artificial urinary sphincter candidates, especially in irradiated patients (36% and 57%, respectively). Patients with prior pelvic radiation continued to be at higher risk for contracture recurrence after artificial urinary sphincter implantation (12%). Two-stage UroLume stent and artificial urinary sphincter placement offered long-term contracture and continence control in 8 of 11 patients with recurrent anastomotic contractures.

CONCLUSIONS

An artificial urinary sphincter is durable treatment for sphincter deficiency even in patients with a history of complications, neurogenic bladder, pelvic radiation, bladder neck contracture, Valsalva voiding, or failed injectables or slings.

Results from the Multicenter Boston Type 1 Keratoprosthesis Study

PURPOSE

To report indications, practices, complications, and outcomes from the first multicenter study on the Boston Type 1 keratoprosthesis.

DESIGN

Prospective, noncomparative, interventional case series.

PARTICIPANTS

We analyzed 141 Boston Type 1 keratoprosthesis surgical procedures, from 17 surgical sites, done from January 2003 through September 2005 in 136 eyes of 133 patients.

METHODS

Forms reporting 70 preoperative, intraoperative, and postoperative parameters were collected and analyzed at a central data collection site (Cornea Consultants of Albany, Albany Medical College, Albany, New York).

MAIN OUTCOME MEASURES

Visual acuity (VA) and keratoprosthesis survival.

RESULTS

Common preoperative diagnoses were graft rejection, in 73 eyes (54%) (average prior grafts, 2.24); chemical injury (20 eyes [15%]); bullous keratopathy (19 eyes [14%]); and herpes simplex virus keratitis (9 eyes [7%]). Additionally, 82 eyes (60%) had preoperative glaucoma. Preoperative best-corrected VA ranged from 20/100 to light perception, and was <20/200 in 96% of eyes. At an average follow-up of 8.5 months (range, 0.03-24; standard deviation, 6.1; median, 12), postoperative vision improved to > or =20/200 in 57%. Among eyes at least 1 year after the operation (62 eyes), vision was > or =20/200 in 56% of eyes and > or =20/40 in 23%. At an average follow-up of 8.5 months, graft retention was 95%. Severe visual loss or failure to improve from keratoprosthesis was usually secondary to comorbidities such as advanced glaucoma, macular degeneration, or retinal detachment.

CONCLUSIONS

The Boston Type 1 keratoprosthesis seems, based on early follow-up, to be a viable option after multiple failed corneal grafts or in some situations of a poor prognosis for primary penetrating keratoplasty.

Management of infection associated with prosthetic joints

In orthopedic implant surgery, infection is rare, but difficult to eradicate. Neither diagnosis nor treatment of such infections is standardized. A MEDLINE search with the keywords "orthopedic implant-related infection" and "joint replacement and infection" identified studies published from 1982-2002. One single randomized controlled trial could be found. In addition, larger retrospective case series and observational studies with clear definition of the observed intervention were also selected for inclusion. A rational algorithm based on clinical experience in orthopedic implant-related infections, observational studies and the controlled trial is presented. The conditions for the different therapeutic options (debridement with retention, one-stage exchange, two-stage exchange, removal without reimplantation or suppressive antibiotic treatment) are presented. The proposed algorithm is based on the interval after implantation (early, delayed, late), the type of infection (exogenous vs hematogenous), the condition of the implant and the soft tissue, as well as comorbidity of the patient. Considering both surgical and antimicrobial therapy, our algorithm facilitates either retrospective evaluation of case series or the planning of well-defined prospective studies.

Treatment outcomes in the tube versus trabeculectomy study after one year of follow-up

PURPOSE

To report one-year results of the Tube Versus Trabeculectomy (TVT) Study.

DESIGN

Multicenter randomized clinical trial.

METHODS

SETTING

17 Clinical Centers.

STUDY POPULATION

Patients 18 to 85 years of age who had previous trabeculectomy and/or cataract extraction with intraocular lens implantation and uncontrolled glaucoma with intraocular pressure (IOP) > or =18 mm Hg and < or =40 mm Hg on maximum tolerated medical therapy.

INTERVENTIONS

350 mm(2) Baerveldt glaucoma implant or trabeculectomy with mitomycin C (MMC).

MAIN OUTCOME MEASURES

IOP, visual acuity, and reoperation for glaucoma.

RESULTS

A total of 212 eyes of 212 patients were enrolled, including 107 in the tube group and 105 in the trabeculectomy group. At one year, IOP (mean +/- SD) was 12.4 +/- 3.9 mm Hg in the tube group and 12.7 +/- 5.8 mm Hg in the trabeculectomy group (P = .73). The number of glaucoma medications (mean +/- SD) was 1.3 +/- 1.3 in the tube group and 0.5 +/- 0.9 in the trabeculectomy group (P < .001). The cumulative probability of failure during the first year of follow-up was 3.9% in the tube group and 13.5% in the trabeculectomy group (P = .017).

CONCLUSIONS

Nonvalved tube shunt surgery was more likely to maintain IOP control and avoid persistent hypotony or reoperation for glaucoma than trabeculectomy with MMC during the first year of follow-up in the TVT Study. Both surgical procedures produced similar IOP reduction at one year, but there was less need for supplemental medical therapy following trabeculectomy with MMC.

The safety and efficacy of the artificial bowel sphincter for fecal incontinence: results from a multicenter cohort study

PURPOSE

The aim of this trial was to evaluate the safety, efficacy, and impact on quality of life of the Acticon trade mark artificial bowel sphincter for fecal incontinence.

METHODS

A multicenter, prospective, nonrandomized clinical trial was conducted under a common protocol. Patients were evaluated with anal physiology, endoanal ultrasonography, a fecal incontinence scoring system, fecal incontinence quality of life assessment, and overall health evaluation. Patients with a fecal incontinence score of 88 or greater (scale, 1-120) were considered candidates for the study. Implanted patients underwent identical reevaluation at 6 and 12 months postimplant.

RESULTS

One hundred twelve of 115 patients (86 females) enrolled were implanted. Mean age was 49 (range, 18-81) years. A total of 384 device-related or potentially device-related adverse events were reported in 99 enrolled patients. Of these events, 246 required no intervention or only noninvasive intervention. Seventy-three revisional operations were required in 51 (46 percent) of the 112 implanted patients. Infection rate necessitating surgical revision was 25 percent. Forty-one patients (37 percent) have had their devices completely explanted, of which 7 have had successful reimplantations. In patients with a functioning neosphincter, improvement in quality of life and anal continence was documented. Mean matched fecal incontinence scores in 63 patients at 6 months follow-up was improved from 105 preimplant to 51 postimplant. In 55 patients at 12 months follow-up, mean matched fecal incontinence scores were 105 preimplant 48 postimplant. A successful outcome was achieved in 85 percent of patients with a functioning device. Intention to treat success rate was 53 percent.

CONCLUSIONS

Although morbidity and the need for revisional surgery are high, the artificial bowel sphincter can improve anal incontinence and quality of life in patients with severe fecal incontinence.

Retinal prosthesis

Retinal prostheses represent the best near-term hope for individuals with incurable, blinding diseases of the outer retina. On the basis of the electrical activation of nerves, prototype retinal prostheses have been tested in blind humans and have demonstrated the capability to elicit the sensation of light and to give test subjects the ability to detect motion. To improve the visual function in implant recipients, a more sophisticated device is required. Simulations suggest that 600-1000 pixels will be required to provide visual function such as face recognition and reading. State-of-the-art implantable stimulator technology cannot produce such a device, which mandates the advancement of the state of the art in areas such as analog microelectronics, wireless power and data transfer, packaging, and stimulating electrodes.

Treatment outcomes in the Ahmed Baerveldt Comparison Study after 1 year of follow-up

PURPOSE

To determine the relative efficacy and complications of the Ahmed glaucoma valve (AGV) model FP7 (New World Medical, Ranchos Cucamonga, CA) and the Baerveldt glaucoma implant (BGI) model 101-350 (Abbott Medical Optics, Abbott Park, IL) in refractory glaucoma.

DESIGN

Multicenter, randomized, controlled clinical trial.

PARTICIPANTS

Two hundred seventy-six patients, including 143 in the AGV group and 133 in the BGI group.

METHODS

Patients 18 to 85 years of age with refractory glaucoma having intraocular pressure (IOP) of 18 mmHg or more in whom an aqueous shunt was planned were randomized to undergo implantation of either an AGV or a BGI.

MAIN OUTCOME MEASURES

The primary outcome was failure, defined as IOP >21 mmHg or not reduced by 20% from baseline, IOP ≤5 mmHg, reoperation for glaucoma or removal of implant, or loss of light perception vision. Secondary outcomes included mean IOP, visual acuity, use of supplemental medical therapy, and complications.

RESULTS

Preoperative IOP (mean±standard deviation [SD]) was 31.2±11.2 mmHg in the AGV group and 31.8±12.5 mmHg in the BGI group (P = 0.71). At 1 year, mean±SD IOP was 15.4±5.5 mmHg in the AGV group and 13.2±6.8 mmHg in the BGI group (P = 0.007). The mean±SD number of glaucoma medications was 1.8±1.3 in the AGV group and 1.5±1.4 in the BGI group (P = 0.071). The cumulative probability of failure was 16.4% (standard error [SE], 3.1%) in the AGV group and 14.0% (SE, 3.1%) in the BGI group at 1 year (P = 0.52). More patients experienced early postoperative complications in the BGI group (n = 77; 58%) compared with the AGV group (n = 61; 43%; P = 0.016). Serious postoperative complications associated with reoperation, vision loss of ≥2 Snellen lines, or both occurred in 29 patients (20%) in the AGV group and in 45 patients (34%) in the BGI group (P = 0.014).

CONCLUSIONS

Although the average IOP after 1 year was slightly higher in patients who received an AGV, there were fewer early and serious postoperative complications associated with the use of the AGV than the BGI.

U.S. Food and Drug Administration clinical trial of the Implantable Contact Lens for moderate to high myopia

PURPOSE

To assess the safety and efficacy of the Implantable Contact Lens (ICL) to treat moderate to high myopia.

DESIGN

Prospective nonrandomized clinical trial.

PARTICIPANTS

Five hundred twenty-three eyes of 291 patients with between 3 and 20.0 diopters (D) of myopia participating in the U. S. Food and Drug Administration clinical trial of the ICL for myopia.

INTERVENTION

Implantation of the ICL.

MAIN OUTCOME MEASURES

Uncorrected visual acuity (UCVA), refraction, best spectacle-corrected visual acuity (BSCVA), adverse events, operative and postoperative complications, lens opacity analysis (Lens Opacity Classification System III), subjective satisfaction, and symptoms.

RESULTS

Twelve months postoperatively, 60.1% of patients had a visual acuity of 20/20 or better, and 92.5% had an uncorrected visual acuity of 20/40 or better. Patients averaged a 10.31-line improvement in UCVA, 61.6% of patients were within 0.5 D, and 84.7% were within 1.0 D of predicted refraction. Only one case (0.2%) lost > 2 lines of BSCVA. Gains of 2 or more lines of BSCVA occurred in 55 cases (11.8%) at 6 months and 41 cases (9.6%) at 1 year after ICL surgery. Early and largely asymptomatic, presumably surgically induced anterior subcapsular (AS) opacities were seen in 11 cases (2.1%); an additional early AS opacity (0.2%) was seen because of inadvertent anterior chamber irrigation of preservative-containing solution at surgery. Two (0.4%) late (> or = 1 year postoperatively) AS opacities were observed. Two (0.4%) ICL removals with cataract extraction and intraocular lens implantation have been performed. Patient satisfaction (very/extremely satisfied) was reported by 92.4% of subjects on the subjective questionnaire; only four patients (1.0%) reported dissatisfaction. Slightly more patients reported an improvement at 1 year over baseline values for the following subjective symptoms: quality of vision, glare, double vision, and night driving difficulties. Only a 3% difference between pre-ICL and post-ICL surgery was reported for haloes.

CONCLUSIONS

The results support the safety, efficacy, and predictability of ICL implantation to treat moderate to high myopia.

Results of Chest Wall Resection and Reconstruction With and Without Rigid Prosthesis

BACKGROUND

Chest wall resections are associated with significant morbidity, with respiratory failure in as many as 27% of patients. We hypothesized that our selective use of a rigid prosthesis for reconstruction reduces respiratory complications.

METHODS

The records of all patients undergoing chest wall resection and reconstruction were reviewed. Patient demographics, use of preoperative therapy, the location and size of the chest wall defect, performance of lung resection if any, the type of prosthesis, and postoperative complications were recorded. Predictor of complications were identified by chi2 and logistic regression analyses.

RESULTS

From January 1, 1995, to July 1, 2003, 262 patients (median age, 60 years) underwent chest wall resection for tumor in 251 (96%), radiation necrosis in 7 (2.7%); and infection in 4 patients (1.3%). The median defect size was 80 cm2 (range, 2.7 to 1,200 cm2) and the median number of ribs resected was 3 (range, 1 to 8). Major lung resection was performed in 85 patients (34%). Prosthetic reconstruction was rigid (polypropylene mesh/methylmethacrylate composite) in 112 (42.7%), nonrigid (polytetrafluoroethylene or polypropylene mesh) in 97 (37%), and none in 53 patients. Postoperatively, 10 patients died (3.8%), 4 of whom had pneumonectomy plus chest wall resection. Respiratory failure occurred in 8 patients (3.1%). By multivariate analysis, the size of the chest wall defect was the most significant predictor of complications.

CONCLUSIONS

Our incidence of respiratory failure is lower than previously reported and may relate to our use of rigid repair for defects likely to cause a flail segment. Pneumonectomy plus chest wall resection should be performed only in highly selected patients.

A transcatheter intracardiac shunt device for heart failure with preserved ejection fraction (REDUCE LAP-HF): a multicentre, open-label, single-arm, phase 1 trial

BACKGROUND

Heart failure with preserved ejection fraction (HFPEF) is a common, globally recognised, form of heart failure for which no treatment has yet been shown to improve symptoms or prognosis. The pathophysiology of HFPEF is complex but characterised by increased left atrial pressure, especially during exertion, which might be a key therapeutic target. The rationale for the present study was that a mechanical approach to reducing left atrial pressure might be effective in HFPEF.

METHODS

The REDUCe Elevated Left Atrial Pressure in Patients with Heart Failure (REDUCE LAP-HF) study was an open-label, single-arm, phase 1 study designed to assess the performance and safety of a transcatheter interatrial shunt device (IASD, Corvia Medical, Tewkesbury, MA, USA) in patients older than 40 years of age with symptoms of HFPEF despite pharmacological therapy, left ventricular ejection fraction higher than 40%, and a raised pulmonary capillary wedge pressure at rest (>15 mm Hg) or during exercise (>25 mm Hg). The study was done at 21 centres (all departments of cardiology in the UK, Netherlands, Belgium, France, Germany, Austria, Denmark, Australia, and New Zealand). The co-primary endpoints were the safety and performance of the IASD at 6 months, together with measures of clinical efficacy, including functional capacity and clinical status, analysed per protocol. This study is registered with ClinicalTrials.gov, number NCT01913613.

FINDINGS

Between Feb 8, 2014, and June 10, 2015, 68 eligible patients were entered into the study. IASD placement was successful in 64 patients and seemed to be safe and well tolerated; no patient had a peri-procedural or major adverse cardiac or cerebrovascular event or need for cardiac surgical intervention for device-related complications during 6 months of follow-up. At 6 months, 31 (52%) of 60 patients had a reduction in pulmonary capillary wedge pressure at rest, 34 (58%) of 59 had a lower pulmonary capillary wedge pressure during exertion, and 23 (39%) of 59 fulfilled both these criteria. Mean exercise pulmonary capillary wedge pressure was lower at 6 months than at baseline, both at 20 watts workload (mean 32 mm Hg [SD 8] at baseline vs 29 mm Hg [9] at 6 months, p=0·0124) and at peak exercise (34 mm Hg [8] vs 32 [8], p=0·0255), despite increased mean exercise duration (baseline vs 6 months: 7·3 min [SD 3·1] vs 8·2 min [3·4], p=0·03). Sustained device patency at 6 months was confirmed by left-to-right shunting (pulmonary/systemic flow ratio: 1·06 [SD 0·32] at baseline vs 1·27 [0·20] at 6 months, p=0·0004).

INTERPRETATION

Implantation of an interatrial shunt device is feasible, seems to be safe, reduces left atrial pressure during exercise, and could be a new strategy for the management of HFPEF. The effectiveness of IASD compared with existing treatment for patients with HFPEF requires validation in a randomised controlled trial.

FUNDING

Corvia Medical Inc.

Intermediate-term clinical experience with the Ahmed Glaucoma Valve implant

PURPOSE

We studied the intermediate-term clinical experience with the Ahmed Glaucoma Valve implant (New World Medical, Inc, Rancho Cucamonga, California).

METHODS

In this multicenter, retrospective case series, we studied 159 eyes (144 patients) treated with the Ahmed Glaucoma Valve with a mean +/- SEM (standard error of mean) follow-up of 13.4 +/- 0.7 months (range, 4 to 44 months). The mean +/- SEM age was 60.9 +/- 1.9 years (range, 0.1 to 103 years). Surgical success was defined as intraocular pressure less than 22 mm Hg and greater than 5 mm Hg without additional glaucoma surgery and without loss of light perception. Postoperative use of antiglaucoma medications was not a criterion for success or failure. The definition of hypotony was intraocular pressure of 5 mm Hg or less in two consecutive visits.

RESULTS

Intraocular pressure was reduced from a mean of 32.7 +/- 0.8 mm Hg before surgery to 15.9 +/- 0.6 mm Hg (P < .0001) at the most recent follow-up after surgery. The number of antiglaucoma medications was decreased from 2.7 +/- 0.1 before surgery to 1.1 +/- 0.1 after surgery (P < .0001). The cumulative probability of success was 87% at 1 year and 75% at 2 years after surgery (Kaplan-Meier life-table analysis). Postoperatively, 24 (15%) of 159 eyes had intraocular pressure greater than or equal to 22 mm Hg. The visual acuity was improved or within one Snellen line in 131 eyes (82%). Complications occurred in 75 eyes (47%), the majority of which did not affect surgical outcome. The most common complication was obstruction of the tube, which was observed in 17 eyes (11%). Transient postoperative hypotony was found in 13 eyes (8%).

CONCLUSIONS

The Ahmed Glaucoma Valve implant is effective in lowering intraocular pressure, and postoperative hypotony is not commonly associated with this implant.

Validation of three-dimensional model-based tibio-femoral tracking during running

The purpose of this study was to determine the accuracy of a radiographic model-based tracking technique that measures the three-dimensional in vivo motion of the tibio-femoral joint during running. Tantalum beads were implanted into the femur and tibia of three subjects and computed tomography (CT) scans were acquired after bead implantation. The subjects ran 2.5m/s on a treadmill positioned within a biplane radiographic system while images were acquired at 250 frames per second. Three-dimensional implanted bead locations were determined and used as a "gold standard" to measure the accuracy of the model-based tracking. The model-based tracking technique optimized the correlation between the radiographs acquired via the biplane X-ray system and digitally reconstructed radiographs created from the volume-rendered CT model. Accuracy was defined in terms of measurement system bias, precision and root-mean-squared (rms) error. Results were reported in terms of individual bone tracking and in terms of clinically relevant tibio-femoral joint translations and rotations (joint kinematics). Accuracy for joint kinematics was as follows: model-based tracking measured static joint orientation with a precision of 0.2 degrees or better, and static joint position with a precision of 0.2mm or better. Model-based tracking precision for dynamic joint rotation was 0.9+/-0.3 degrees , 0.6+/-0.3 degrees , and 0.3+/-0.1 degrees for flexion-extension, external-internal rotation, and ab-adduction, respectively. Model-based tracking precision when measuring dynamic joint translation was 0.3+/-0.1mm, 0.4+/-0.2mm, and 0.7+/-0.2mm in the medial-lateral, proximal-distal, and anterior-posterior direction, respectively. The combination of high-speed biplane radiography and volumetric model-based tracking achieves excellent accuracy during in vivo, dynamic knee motion without the necessity for invasive bead implantation.