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

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.

[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.

Prevalence and outcomes of patients receiving implantable cardioverter-defibrillators for primary prevention not based on guidelines

Implantable cardioverter-defibrillator (ICD) implantation outside practice guidelines remains contentious, particularly during the mandated waiting periods in patients with recent cardiac events. We assessed the prevalence and outcomes of non-guideline-based (NGB) ICD implantations in a tertiary academic medical center, with a specific focus on adjudication of arrhythmia events. All patients who underwent initial primary prevention ICD implantation at our institution from 2004 to 2012 were categorized as having received guideline-based (GB) or NGB implants and were retrospectively assessed for first episode of appropriate ICD therapy and total mortality. Of 807 patients, 137 (17.0%) received NGB implants. During a median follow-up of 2.9 years, patients with NGB implants had similar times to first appropriate ICD therapy (median time to event 1.94 vs 2.17 years in patients with GB implants, p = 0.20). After multivariable analysis, patients with NGB implants remained at higher risk for death (hazard ratio 1.54, 95% confidence interval 1.1 to 2.2, p = 0.03) but not appropriate ICD therapy (hazard ratio 0.83, 95% confidence interval 0.5 to 1.3, p = 0.51). Furthermore, only 1 of 125 patients who underwent implant within the 40-day waiting period after myocardial infarction or 3-month waiting period after revascularization or cardiomyopathy diagnosis received an appropriate therapy within this period. In conclusion, few patients received NGB ICD implants in our academic medical center. Although these patients have similar long-term risk of receiving appropriate ICD therapy compared with patients with GB implants, this risk is very low during the waiting periods mandated by clinical practice guidelines. These results suggest that there is little need to rush into implanting ICDs during these waiting periods.

Intra- and inter-observer reliability of combined segmental measurement techniques for predicting immediate post-deployment intraluminal tracheal stent length in dogs

This study evaluated segmental measurement techniques for predicting immediate post-deployment intraluminal tracheal stent length in dogs with naturally occurring tracheal collapse. Radiographs of 12 client-owned dogs that underwent intraluminal tracheal stent placement were retrospectively reviewed. Tracheal lengths were divided into 1, 2, 3, or 4 equal segments. Stent lengths were predicted using the widest dorsoventral height of each segment, with and without the addition of 10%, and an accompanying foreshortening chart. Techniques were compared for intra- and inter-observer reliability, and post-deployment stent length predictability. There was good to high intra- and inter-observer reliability for all segmental measurements; median intra-class correlation coefficients were 0.98 and 0.92, respectively. Measuring 2 segments without the addition of 10% to the widths was significantly more accurate in predicting immediate post-deployment stent length in terms of percent (P = 0.03) and absolute difference (P = 0.02). Segmental measuring techniques are repeatable amongst observers and may help guide stent selection.

Mechanical endurance and in vivo radiographic analysis of a flexible, mono-unit cervical disc implant in intermediate follow-up period

AIM

The flexible artificial disc may create a system with a biomimetic structure that has the potential to tolerate dynamic motion in a way similar to a normal intervertebral disc over a long period. The objective was to evaluate the mechanical feasibility and clinical and radiological findings with a mono-unit and flexible artificial disc at intermediate-term follow-up.

METHODS

Fifty-six patients with degenerative disc disease were selected to participate in the study. They underwent discectomy with a flexible artificial disc with a mean follow-up period of 24.8 months. Outcomes were evaluated with the visual analogue scale (VAS) and Oswestry Disability Index (ODI). Mechanical endurance was evaluated by a dynamic testing.

RESULTS

Fifty one-levels and six bi-levels were included in the study (average age 41.8 years). VAS improved from 6.8 ± 2.2 to 1.5 ± 1.7 (P<0.05) and ODI improved from 43.1 ± 10.4 to 18.2 ± 10.2 (P<0.05). Disc height before mechanical testing was 8.9 mm, and decreased to 8.4 mm after six million cycles with no mechanical failure.

CONCLUSION

Our results indicate that flexible and mono-unit cervical disc provides favorable mechanical performance and clinical outcomes for at least a relatively intermediate-term follow up period. It is indicated that the flexible cervical disc maintains mobility at the level of the prosthesis that is comparable with preoperative ranges of motion. Further evaluation will be completed once long-term results have been obtained.

[Prosthetic rehabilitation: needs in Senegalese dental offices]

Knowledge of dental prosthetic needs will develop strategies for prevention and treatment through a package of individual, community and professional policies. The aim of this study was to evaluate prosthetic needs in Senegalese dental offices. The survey was conducted among people aged 15 years and more attending Senegalese dental clinics. The mean number of missing teeth was 4.4. Only 55.3% of the sample expressed the need for dentures and 81.8% had a diagnosed need for prosthesis. A statistically significant difference was noticed between the needs diagnosed and the expressed needs (p < 0.0001). Finally, this study reveals that the need for prosthetic treatment is real in the Senegalese dental offices.

Stent implantation into the interatrial septum in patients with univentricular heart and a secondary restriction of interatrial communication

BACKGROUND

Presence of a restrictive interatrial communication in patients with univentricular anatomy significantly affects surgical outcomes. In patients with univentricular hearts, wide open atrial communication leads to lower pulmonary artery pressure, which is one of the most important factors influencing the success of bidirectional Glenn and Fontan operations. In some patients, recurrence of restricted interatrial communication can be observed despite initially successful interventional or surgical creation of unrestrictive interatrial communication.

AIM

To evaluate efficacy of stent implantation into the interatrial septum in patients with univentricular heart and a secondary restriction of interatrial communication.

METHODS

In 2006-2010, we created unrestrictive interatrial communication by stent implantation into the interatrial septum in 7 children with univentricular anatomy with systemic right ventricle (4 patients with hypoplastic left heart syndrome and 3 patients with mitral atresia). In all patients we diagnosed recurrent restriction of interatrial communication despite prior surgical or interventional creation of unrestrictive interatrial communication. Patient age at stent implantation was 3 to 30 months. Maximal systolic pressure gradient between the left and the right atrium was 6-29 mm Hg and left atrial pressure ranged from 20/17/19 mm Hg to 40/29/32 mm Hg. In all patients, we implanted a Palmaz-Genesis stent (length 18-29 mm) with subsequent balloon redilatation.

RESULTS

In all 7 patients, we created unrestrictive interatrial communication with mean pressure gradient reduction from 13.14 mm Hg to 0.86 mm Hg (p < 0.006). Mean interatrial communication diameter increased from 4.14 mm to 10.57 mm (p < 0.0001).

CONCLUSIONS

Percutaneous stent implantation into the interatrial septum in children with univentricular heart and secondary restriction of interatrial communication is a safe and effective method. Kardiol Pol 2011; 69, 11: 1137-1141.

[Choice of the surgical approach for implantation of a left ventricular lead by the data of prolonged coronaroangiography]

Effectiveness of prolonged coronarography was assessed for investigation of venous heart anatomy with reference to etiology of the disease and heart chamber sizes. It was shown that lesions of the coronary arteries and morphometrical indices of the heart did not influence the heart venous anatomy. A detailed analysis of patients with ischemic heart disease and anamnesis of myocardial infarction has revealed the absence of the heart vein in the zone of old myocardial infarction. At the preoperative stage the placement of a cardiac resyncronising device the integration of data of EchoKG, prolonged coronaroangiography and others allows determination of the possible surgical method of placing the lead to the left ventricle of the heart. The algorithm of the method of decision on the placement of the left ventricular lead has been developed, investigated and introduced into clinical practice.

The Ahmed glaucoma valve in neovascular glaucoma (An AOS Thesis)

PURPOSE

To evaluate the results of Ahmed glaucoma valve surgery in neovascular glaucoma and control patients.

METHODS

In this retrospective comparative study, we reviewed 76 eyes of 76 patients, comparing the surgical outcomes in control patients (N=38) to matched neovascular glaucoma patients (N=38). Success was defined as intraocular pressure (IOP) > or =6 mm Hg and < or =21 mm Hg, without further glaucoma surgery, and without loss of light perception.

RESULTS

Average follow-up for control and neovascular glaucoma patients was 18.4 and 17.4 months, respectively (P = .550). At last follow-up, mean IOP was 16.2 +/- 5.2 mm Hg and 15.5 +/- 12.5 mm Hg (P = .115) in control and neovascular glaucoma patients, respectively. Life-table analysis showed a significantly lower success for neovascular glaucoma patients compared with controls (P = .0096), with success at 1 year of 89.2% and 73.1%, at 2 years of 81.8% and 61.9%, and at 5 years of 81.8% and 20.6% for control and neovascular glaucoma eyes, respectively. Cox proportional hazards regression analysis showed neovascular glaucoma as a risk factor for surgical failure (odds ratio, 5.384, 95% CI, 1.22-23.84, P = .027). Although IOP control and complications were comparable between the two groups, visual outcomes were worse in neovascular glaucoma patients, with 9 eyes (23.7%) with neovascular glaucoma compared with no controls losing light perception vision (P = .002). The majority with loss of vision (5 of 9) had successful control of IOP during the postoperative period.

CONCLUSION

Neovascular glaucoma patients have greater risk of surgical failure after Ahmed glaucoma valve surgery compared with controls. Despite improved mean IOP with drainage implants, visual outcomes may be poor, possibly due to progression of underlying disease.

Association of physician certification and outcomes among patients receiving an implantable cardioverter-defibrillator

CONTEXT

Allowing nonelectrophysiologists to perform implantable cardioverter-defibrillator (ICD) procedures is controversial. However, it is not known whether outcomes of ICD implantation vary by physician specialty.

OBJECTIVE

To determine the association of implanting physician certification with outcomes following ICD implantation.

DESIGN, SETTING, AND PATIENTS

Retrospective cohort study using cases submitted to the ICD Registry performed between January 2006 and June 2007. Patients were grouped by the certification status of the implanting physician into mutually exclusive categories: electrophysiologists, nonelectrophysiologist cardiologists, thoracic surgeons, and other specialists. Hierarchical logistic regression models were developed to determine the independent association of physician certification with outcomes.

MAIN OUTCOME MEASURES

In-hospital procedural complication rates and the proportion of patients meeting criteria for a defibrillator with cardiac resynchronization therapy (CRT-D) who received that device.

RESULTS

Of 111,293 ICD implantations included in the analysis, 78,857 (70.9%) were performed by electrophysiologists, 24,399 (21.9%) by nonelectrophysiologist cardiologists, 1862 (1.7%) by thoracic surgeons, and 6175 (5.5%) by other specialists. Compared with patients whose ICD was implanted by electrophysiologists, patients whose ICD was implanted by either nonelectrophysiologist cardiologists or thoracic surgeons were at increased risk of complications in both unadjusted (electrophysiologists, 3.5% [2743/78,857]; nonelectrophysiologist cardiologists, 4.0% [970/24,399]; thoracic surgeons, 5.8% [108/1862]; P < .001) and adjusted analyses (relative risk [RR] for nonelectrophysiologist cardiologists, 1.11 [95% confidence interval {CI}, 1.01-1.21]; RR for thoracic surgeons, 1.44 [95% CI, 1.15-1.79]). Among 35,841 patients who met criteria for CRT-D, those whose ICD was implanted by physicians other than electrophysiologists were significantly less likely to receive a CRT-D device compared with patients whose ICD was implanted by an electrophysiologist in both unadjusted (electrophysiologists, 83.1% [21 303/25,635]; nonelectrophysiologist cardiologists, 75.8% [5950/7849]; thoracic surgeons, 57.8% [269/465]; other specialists, 74.8% [1416/1892]; P < .001) and adjusted analyses (RR for nonelectrophysiologist cardiologists, 0.93 [95% CI, 0.91-0.95]; RR for thoracic surgeons, 0.81 [95% CI, 0.74-0.88]; RR for other specialists, 0.97 [95% CI, 0.94-0.99]).

CONCLUSIONS

In this registry, nonelectrophysiologists implanted 29% of ICDs. Overall, implantations by a nonelectrophysiologist were associated with a higher risk of procedural complications and lower likelihood of receiving a CRT-D device when indicated compared with patients whose ICD was implanted by an electrophysiologist.

A cross validation study of deep brain stimulation targeting: from experts to atlas-based, segmentation-based and automatic registration algorithms

Validation of image registration algorithms is a difficult task and open-ended problem, usually application-dependent. In this paper, we focus on deep brain stimulation (DBS) targeting for the treatment of movement disorders like Parkinson's disease and essential tremor. DBS involves implantation of an electrode deep inside the brain to electrically stimulate specific areas shutting down the disease's symptoms. The subthalamic nucleus (STN) has turned out to be the optimal target for this kind of surgery. Unfortunately, the STN is in general not clearly distinguishable in common medical imaging modalities. Usual techniques to infer its location are the use of anatomical atlases and visible surrounding landmarks. Surgeons have to adjust the electrode intraoperatively using electrophysiological recordings and macrostimulation tests. We constructed a ground truth derived from specific patients whose STNs are clearly visible on magnetic resonance (MR) T2-weighted images. A patient is chosen as atlas both for the right and left sides. Then, by registering each patient with the atlas using different methods, several estimations of the STN location are obtained. Two studies are driven using our proposed validation scheme. First, a comparison between different atlas-based and nonrigid registration algorithms with a evaluation of their performance and usability to locate the STN automatically. Second, a study of which visible surrounding structures influence the STN location. The two studies are cross validated between them and against expert's variability. Using this scheme, we evaluated the expert's ability against the estimation error provided by the tested algorithms and we demonstrated that automatic STN targeting is possible and as accurate as the expert-driven techniques currently used. We also show which structures have to be taken into account to accurately estimate the STN location.

Evaluation of an automated seed loader for seed calibration in prostate brachytherapy

Automated seed loaders for permanent prostate implants are now commercially available. Besides improved radiation safety, these systems offer seed assay capability and ease of needle loading, making preplanned as well as intra‐operative implant procedures more time‐efficient. The Isoloader (Mentor Corp., CA) uses individual I125 seeds (SL‐125 ProstaSeed) loaded in up to 199 chambers inside a shielded cartridge. The unit performs seed counting and calibration using a built‐in solid‐state detector. In order to evaluate the reproducibility and accuracy of the calibration process, two test cartridges were measured with the Isoloader itself and compared with a well‐type ionization chamber (HDR‐1000Plus, Standard Imaging).

The air kerma strength measurements for all seeds using the Isoloader had a standard deviation of about 2.7%. For the eight seeds assayed more intensively using both the Isoloader and well chamber, the standard deviations of the measurements for each seed were in the range of 0.8% to 2.8% and 0.6% to 1.3%, respectively. The variation in the Isoloader calibration is attributed to small detector solid angle and bead geometry within seed capsules (verified by radiographs). The reproducibility of the air kerma strength measured by the Isoloader was comparable to that from the well chamber and was clinically acceptable. Seed strength measured with the Isoloader was on average 1%~2% larger than that measured with the well chamber, indicating that the accuracy of the Isoloader was clinically acceptable.

PACS numbers: 87.53.Jw, 87.53.Xd, 87.56.Fc

Facteurs de risque des expositions prothétiques après cure de prolapsus génital par voie vaginale

OBJECTIVES

Prosthetic reinforcement in the surgical repair of pelvic prolapse by the vaginal approach is currently on the increase. However, this technique is not without tolerance-related problems. The most frequently described complication is prosthesis exposure, including erosion and delayed healing. It is independent of a granuloma and a major infection as pelvic cellulitis. Its mechanism is associated with defective vaginal healing. The purpose of our study is to define the risk factors for exposure of the prosthetic material.

PATIENTS AND METHODS

Two hundred and seventy-seven medical records relating to patients undergoing surgery due to pelvic prolapse were included in our study. The treatment of genital prolapse was managed via the vaginal approach with polypropylene mesh. This is a continuous, retrospective study conducted over a period of 24 months.

RESULTS

Thirty-four cases of prosthesis exposure were observed in the 2 months following surgery, which represents an incidence of 12.27%. The risk factors are concomitant hysterectomy [odds ratio 5.17 (P = 0.001)] and inverted T colpotomy [odds ratio 6.06 (P = 0.01)]. The protective factors are preservation of the uterus and the performance of a minor colpotomy in patients who had already undergone a hysterectomy or in those whose uterus had been preserved [odds ratio 5.16 (P = 0.0001)].

DISCUSSION AND CONCLUSION

In our study, we have only found risk factors of operative protocol. In fact, other information as age, menopause status or medical history of the patient is not significant. The uterus must be preserved and the number and extent of colpotomies needed to insert the prosthesis must be limited.

Standards for Modified Osteoodontokeratoprosthesis (OOKP) Surgery According to Strampelli and Falcinelli

PURPOSE

To establish a time-proven "gold standard" in modified osteoodontokeratoprosthesis (OOKP) surgery.

METHODS

The OOKP is the procedure of choice for restoring sight in patients with corneal blindness caused by end-stage ocular surface disease not amenable to penetrating keratoplasty. Members of the OOKP Study Group met in Rome, Italy in 2001 and Vienna, Austria in 2002 to discuss indications and contraindications, patient selection, surgical technique, postoperative care, and recognition and management of complications of OOKP surgery according to Strampelli and modified by Falcinelli.

RESULTS

Falcinelli's modification of Strampelli's technique of OOKP surgery remains the gold standard as far as visual and keratoprosthesis-retention results are concerned. The agreement on indications and contraindications, patient selection, surgical technique, postoperative care, and recognition and management of complications of this technique of OOKP surgery is summarized in the text of this manuscript.

CONCLUSION

This standard technique of modified OOKP surgery, where adequately performed, is capable of providing excellent anatomic and functional results even in the long term. In patients with corneal blindness untreatable by other approaches, we strongly recommend this technique for visual rehabilitation. Students of OOKP surgery should become familiar with the protocol described in this paper before subjecting the technique to further modifications.

A prospective, randomized, multicenter Food and Drug Administration investigational device exemption study of lumbar total disc replacement with the CHARITE artificial disc versus lumbar fusion: part II: evaluation of radiographic outcomes and correlation of surgical technique accuracy with clinical outcomes

STUDY DESIGN

A prospective, randomized, multicenter, Food and Drug Administration-regulated, investigational device exemption clinical trial.

OBJECTIVES

To compare the safety and effectiveness of lumbar total disc replacement (TDR) with the CHARITE artificial disc (DePuy Spine, Raynham, MA) to anterior lumbar interbody fusion for the treatment of single-level degenerative disc disease from L4-S1 unresponsive to nonoperative treatment. In addition, to evaluate the radiographic outcomes of lumbar artificial disc replacement at either L4-L5 or L5-S1 with the CHARITE artificial disc as compared to anterior lumbar interbody fusion with cylindrical cages and iliac crest bone graft; and to determine if a correlation exists between clinical outcomes and surgical accuracy of TDR placement within the disc space.

SUMMARY OF BACKGROUND DATA

Prior investigators have reported excellent radiographic results with the CHARITE artificial disc for the treatment of lumbar degenerative disc disease. These encouraging results are the product of retrospective reviews without a control. Very few studies have reported on the segmental motion of an intervertebral level implanted with an artificial disc, and no studies have reported a correlation of radiographic and clinical outcomes.

METHODS

A prospective, randomized, multicenter, US Food and Drug Administration, investigational device exemption study with 24-month follow-up was performed at 14 centers throughout the United States. A total of 304 subjects were randomized in a 2:1 ratio, with 205 in the investigational group (TDR with the CHARITE artificial disc) and 99 in the control group (anterior lumbar interbody fusion with BAK cages and iliac crest bone graft). A total of 71 TDR training cases were performed (up to 5 at each site) before randomization beginning at each site. Plain radiographs were analyzed for each subject in both groups regarding range of motion (ROM) in flexion/extension, restoration of disc space height, and subsidence. Prosthesis placement in the coronal and midsagittal planes was analyzed for the 276 patients with TDR. Correlations were performed between prosthesis placement and clinical outcomes.

RESULTS

Patients in the investigational group had a 13.6% mean increase, and those in the control group an 82.5% decrease in mean flexion/extension ROM at 24 months postoperatively compared to baseline. Patients in the investigational group had significantly better restoration of disc height than the control group (P < 0.05). There was significantly less subsidence in the investigational group compared to the control group (P < 0.05). The surgical technical accuracy of CHARITE artificial disc placement was divided into 3 groups: I, ideal (83%); II, suboptimal (11%); and III, poor (6%), and correlated with clinical outcomes. The flexion/extension ROM and prosthesis function improved with the surgical technical accuracy of radiographic placement (P = 0.003).

CONCLUSIONS

Preoperative ROM in flexion/extension was restored and maintained in patients receiving a TDR. TDR with the CHARITE artificial disc resulted in significantly better restoration of disc space height, and significantly less subsidence than anterior interbody fusion with BAK cages. Clinical outcomes and flexion/extension ROM correlated with surgical technical accuracy of CHARITE artificial disc placement. In the majority of cases, placement of the CHARITE artificial disc was ideal.

Delivery of stents to target lesions: techniques of intraoperative stent implantation and intraoperative angiograms

Mullins et al. [6] reported the first use of stent implantation to treat stenotic branch pulmonary arteries in 1988. In the early to mid-1990s, numerous reports confirmed its safety and efficacy, but there were limited stent and balloon designs and stent implantations were performed using relatively large delivery systems (10- to 12-Fr sheaths) [7, 8]. The general accepted patient size was limited to those weighing 12 kg or greater. Intraoperative stent implantation for branch pulmonary artery stenosis was reported in the early to mid-1990s [1-3, 5, 9]. Indications in these early reports included small patient size or difficult anatomy or patients who had additional cardiac lesions and needed surgery independent of the branch stenosis. The idea was to take advantage of the open-heart exposure provided in the operating room to permit direct access to the stenotic segment. Hence, all intraoperative stent implants were performed under direct visualization on bypass. There were no discussions on advantages over the routine percutaneous approach. Currently, with advances in stent and balloon technology as well as increased operator experience, many of those reported cases probably would have undergone cardiac catheterization for a percutaneous stent implant rather than open-heart surgery. The purpose of this report is to review the current indications, advantages, and disadvantages of intraoperative stent implantation as well as to discuss the techniques that are helpful to optimize intraoperative stent positioning. The role and advantages of intraoperative angiography will also be presented.

Incomplete Stent Apposition After Implantation of Paclitaxel-Eluting Stents or Bare Metal Stents

BACKGROUND

The clinical impact of late incomplete stent apposition (ISA) for drug-eluting stents is unknown. We sought to prospectively investigate the incidence and extent of ISA after the procedure and at 6-month follow-up of paclitaxel-eluting stents in comparison with bare metal stents (BMS) and survey the clinical significance of ISA over a period of 12 months.

METHODS AND RESULTS

TAXUS II was a randomized, double-blind study with 536 patients in 2 consecutive cohorts comparing slow-release (SR; 131 patients) and moderate-release (MR; 135 patients) paclitaxel-eluting stents with BMS (270 patients). This intravascular ultrasound (IVUS) substudy included patients who underwent serial IVUS examination after the procedure and at 6 months (BMS, 240 patients; SR, 113; MR, 116). The qualitative and quantitative analyses of ISA were performed by an independent, blinded core laboratory. More than half of the instances of ISA observed after the procedure resolved at 6 months in all groups. No difference in the incidence of late-acquired ISA was observed among the 3 groups (BMS, 5.4%; SR, 8.0%; MR, 9.5%; P=0.306), with a similar ISA volume (BMS, 11.4 mm3; SR, 21.7 mm3; MR, 8.5 mm3; P=0.18). Late-acquired ISA was the result of an increase of vessel area without change in plaque behind the stent. Predictive factors of late-acquired ISA were lesion length, unstable angina, and absence of diabetes. No stent thrombosis occurred in the patients diagnosed with ISA over a period of 12 months.

CONCLUSIONS

The incidence and extent of late-acquired ISA are comparable in paclitaxel-eluting stents and BMS. ISA is a pure IVUS finding without clinical repercussions.

A technical evaluation of the Nucletron FIRST system: conformance of a remote afterloading brachytherapy seed implantation system to manufacturer specifications and AAPM Task Group report recommendations

The Fully Integrated Real‐time Seed Treatment (FIRST™) system by Nucletron has been available in Europe since November 2001 and is being used more and more in Canada and the United States. Like the conventional transrectal ultrasound implant procedure, the FIRST system utilizes an ultrasound probe, needles, and brachytherapy seeds. However, this system is unique in that it (1) utilizes a low‐dose‐rate brachytherapy seed remote afterloader (the seedSelectron), (2) utilizes 3D image reconstruction acquired from electromechanically controlled, nonstepping rotation of the ultrasound probe, (3) integrates the control of a remote afterloader with electromechanical control of the ultrasound probe for integrating the clinical procedure into a single system, and (4) automates the transfer of planning information and seed delivery to improve quality assurance and radiation safety. This automated delivery system is specifically intended to address reproducibility and accuracy of seed positioning during implantation. The FIRST computer system includes two software environments: SPOT PRO™ and seedSelectron™; both are used to facilitate treatment planning and brachytherapy seed implantation from beginning to completion of the entire procedure. In addition to these features, the system is reported to meet certain product specifications for seed delivery positioning accuracy and reproducibility, seed calibration accuracy and reliability, and brachytherapy dosimetry calculations. Consequently, a technical evaluation of the FIRST system was performed to determine adherence to manufacturer specifications and to the American Association of Physicists in Medicine (AAPM) Task Group Reports 43, 53, 56, 59, and 64 and recommendations of the American Brachytherapy Society (ABS). The United States Nuclear Regulatory Commission (NRC) has recently added Licensing Guidance for the seedSelectron system under 10 CFR 35.1000. Adherence to licensing guidance is made by referencing applicable AAPM Task Group recommendations. In general, results of this evaluation indicated that the system met its claimed specifications as well as the applicable recommendations outlined in the AAPM and ABS reports.

PACS number(s): 87.53.Xd, 87.53.Jw

Operative treatment of massive ventral hernia using polypropylene mesh: A challenge for surgeon and anesthesiologist

OBJECTS

Surgical repair of very large ventral hernias has become feasible after the introduction of synthetic meshes and developments in intensive-care treatment. In addition to the operative challenges, postoperative disorders in the cardiovascular system, tissue oxygenation, increased intra-abdominal pressure, and pulmonary embolism expose the patient to severe risks.

METHODS

From 1997-2002 we operated on ten patients with giant ventral incisional or umbilical hernia (mean defect size 240 cm(2)) by using retromuscular polypropylene mesh. All patients were morbidly obese [mean Body Mass Index (BMI) 39+/-7.2 kg/m(2)]. Four of the operations were emergencies because of an acute intestinal occlusion, bowel gangrene, and skin complications. The patients were reinvestigated after the mean follow-up of 2.5 years to find out the frequency of recurrence and degree of disability.

RESULTS AND CONCLUSION

There was no intraoperative mortality, but one patient died at home after 5 weeks because of myocardial infarct and prolonged wound infection. She had mild stable coronary heart disease preoperatively. Although minor wound complications were observed in three patients, there was no need to remove the meshes. One small recurrent hernia was observed in the follow-up, but it was too small to be repaired. The quality of life after surgery was good for all patients, and they were satisfied with the operation. Retromuscular mesh hernioplasty associated with careful patient monitoring in intensive care is safe and feasible in the selected patients with massive ventral hernia.

Factors influencing surgeons’ choice of method for hernia repair technique

Tension-free hernioplasty is performed using prosthetic material in one-half of hernia repair procedures in Poland but in 85% of those in the region of Pomerania. This questionnaire study of surgeons in Pomerania examined their sources of knowledge about and the factors influencing their choice of groin hernia surgery. The questionnaire was sent to surgeons from 19 hospitals and was answered by 109 (83% of hernia surgeons in the region). We analyzed their reported knowledge of particular operative techniques, factors important in selecting the technique (personal experience, trends in surgical center), and the available sources of information (e.g., medical literature, internet, information from teachers, sales representatives). All respondents reported being familiar with and able to perform tension-free techniques, but only 44% are influenced by their individual professional skills in selecting the technique. Another 44% base their decision on trends in their hospital, and only 22% consider the patient's preferences. The most frequently quoted sources of scientific information are articles in the medical literature and conference reports (90%). Only 8% of the respondents are governed in their professional work by information from pharmaceutical company representatives. Most surgeons (70%) would prefer to make a decision about using a new surgical technique after practical training sessions or workshops led by experienced colleagues. In contrast to common opinion, the information from sales representatives are of only minor importance compared to that of evidence-based data and attendance at workshops and courses.

Tension-free vaginal tape and laparoscopic mesh colposuspension in the treatment of stress urinary incontinence: immediate outcome and complications--a randomized clinical trial

BACKGROUND

The purpose of the study was to evaluate the immediate outcome and complications of the tension-free vaginal tape (TVT) and laparoscopic mesh colposuspension (LC) procedures in the treatment of female stress urinary incontinence (SUI).

METHODS

One hundred and twenty-eight patients suffering from urodynamically confirmed SUI were recruited to this multicenter, randomized clinical trial. After randomization there were seven drop-outs--121 patients were operated upon: 70 patients in the TVT group and 51 in the LC group. The patients were evaluated according to the study protocol before operation and 6 weeks after it. The independent sample t-test and the Mann-Whitney U-test were used to calculate statistical differences between the study groups.

RESULTS

Immediate cure rates, defined as negative stress test with 300 mL saline in the bladder, were similar (92.9% in the TVT group and 88.2% in the LC group; p = ns). Return to normal voiding was faster in the TVT group (9.2 h in the TVT group vs. 24.4 h in the LC group; p = 0.004). Fewer analgesics were used in the TVT group and hospital stay was shorter in this group. Complication rates associated with the procedures were similar and the number of complications was small.

CONCLUSIONS

The immediate outcome of both procedures is the same. The rates of complications were similar. However, the TVT procedure seems to be less invasive and requires fewer hospital resources than LC.

[Surgical treatment of genital prolapse with a new lateral prosthetic hysteropexia technique combining vaginal and laparoscopic methods]

We describe a new surgical treatment of pelvic organ prolapse. The anterior and medium compartments are treated by a transversal hysteropexy by means of an anterior prosthesis fixed by vaginal route and by laparoscopy. The principle is based on the operative technique described by Kapandji but the prosthesis is fixed to the fascia of the external oblique muscle in a subperitoneal path. The posterior compartment is treated by a vaginal route exclusively. A posterior prosthesis is placed in the rectovaginal space and fixed to the elevator muscles. Further studies are necessary to evaluate this new operative technique.

Transvaginal bone anchors in female stress urinary incontinence: poor results

OBJECTIVE

This study evaluates the results of a minimally invasive technique for correcting female stress urinary incontinence by transvaginal implantation of pubic bone anchors.

PATIENTS AND METHODS

Female stress urinary incontinence was treated by fixing a gelatin-coated Dacron sling between two miniature titanium anchors with Prolene sutures.

RESULTS

A total of 26 patients (median age 57.2 years) underwent the sling procedure. The follow-up examination was performed after 11.4 months on average. Stress incontinence showed a median improvement from grade 2 to grade 0.5 (p = 0.01), although only 16 of the 26 patients were completely continent. Urethral pressure and functional length were not significantly influenced. Impaired vaginal wound healing was seen in 14 of the 26 patients (53.8%), and 13 of them underwent revision. All patients affected (15/26, 57.7%) as well as 1 with uneventful healing showed sensory urge symptoms or detrusor instability (7/26, 26.9%). The correlation between impaired wound healing and detrusor instability was highly significant (p < 0.003). 17 of the 26 patients (65.3%) were dissatisfied or very dissatisfied with the intervention. The unfavorable results did not significantly correlate with the patients' age, the number of previous operations, or the surgeon's skill.

CONCLUSION

In view of the poor vaginal wound healing and the resultant irritative symptoms, transvaginal bone anchoring with fixation of a Dacron sling must be regarded as an unsuitable technique.

Chronic, preclinical assessment of the Medtronic Advantage aortic valve prosthesis

BACKGROUND AND AIMS OF THE STUDY

Medtronic, Inc. has designed and developed a new bileaflet, aortic prosthesis (Advantage) and, following an in-vitro analysis, a chronic in-vivo 20-week evaluation was performed in sheep.

METHODS

Fourteen adult male and female sheep underwent implantation of either a 19 mm Advantage or St. Jude Medical (SJM) aortic prosthetic valve for chronic in-vivo evaluation, using a previously reported aortic model technique.

RESULTS

There were two operative deaths, and the remaining sheep (eight with Advantage, four with SJM prostheses) underwent chronic hemodynamic and pathologic evaluations at approximately 140 days. One sheep (SJM prosthesis) died unexpectedly at 122 days; postmortem evaluation revealed valvular thrombosis, though the valve was well seated with no excessive pannus formation or paravalvular leaks. Hemodynamic and hematologic data in the remaining sheep were comparable. Pathologic examination of the remaining implanted valves revealed well-seated prostheses, with no evidence of thrombosis, no excessive pannus formation, and no evidence of paravalvular leaks.

CONCLUSION

This preclinical animal study showed that the Advantage prosthesis has acceptable features, including equivalent hemodynamic and hematologic data, and a lack of pathological abnormalities when compared with a commercially available prosthetic bileaflet mechanical valve.

[Intracorneal ring segments for the correction of myopia--suggestions to ensure a high standard of quality]

INTRODUCTION

The implantation of intracorneal ring segments (ICR-S) is the first reversible refractive surgical technique for the correction of low myopia. It is an effective and safe technique with a low rate of complications. Despite numerous publications it is a relatively new technique and its long-term tolerance cannot yet be assessed. Hence, it is recommendable to examine operated patients according to a standardised protocol for a longer period of time postoperatively. In this paper we present appropriate documentation forms.

MATERIAL AND METHODS

Based on experience gained in more than 100 ring implantations and a follow-up of three years, suggestions for follow-up dates and methods were developed.

RESULTS

Follow-up dates are recommended before surgery, on the day of surgery, on the 1 st postoperative day, after the first postoperative week and the first, third, sixth and twelfth postoperative months and thereafter annually. The examination methods are listed in nine different documentation forms adapted to each follow-up date. In the Ophthalmological Department of the Clinic of Neubrandenburg, Germany, anonymous data are recorded by electronic data processing continuously and analyzed every three months. This guarantees to continually ensure the standard of quality. Other centres implanting intracorneal ring segments are welcome to make use of this system.

SUMMARY

The documentation forms are a suggestion for standardisation of the follow-up after implantation of intracorneal ring segments. The adaptation of the forms to the further development is necessary and planned. It allows a comparison and early feedback on own results and is a contribution to long-term observation and to ensure a high standard of quality in a patient-oriented standard of care.

[Outcome of punctal plug occlusion therapy for severe dry eye syndrome]

PURPOSE

Punctal occlusion using a silicone plug is one way of treating tear-deficient dry eye and it has been reported to be effective. We studied the outcome of punctal plug occlusion therapy for severe dry eye syndrome at our dry eye clinic.

SUBJECTS AND METHODS

Subjects were 76 eyes of 51 patients [6 eyes of 5 males, 70 eyes of 46 females, mean age: 58.6 +/- 13.4 (mean +/- standard deviation), 49 eyes of 30 patients with Sjögren's syndrome, 27 eyes of 21 patients without Sjögren's syndrome] with severe tear-deficient dry eye who underwent punctal occlusion using a silicone plug (Punctal plug, FCI Co. Ltd, France) during the period of Nov. 1996 to Mar. 2000 at our dry eye clinic. They were under observation for 632 +/- 405 days (mean +/- standard deviation). We studied if there is difference in tolerance between the sizes of punctal plug, compared epithelial damage before and after plug insertion, and studied relief in symptoms using self-assessment.

RESULTS

In tolerance of punctal plugs, 55.9% of all plugs were lost during our follow up, but there was no difference in time to loss between the sizes. Epithelial damage was reduced (p < 0.001). Dryness was the most reduced symptom: 26 patients (79%) got better, and only epiphora was increased, with 12 patients (36%) complaining slightly.

CONCLUSION

Punctal plug occlusion therapy for tear-deficient dry eye is conclusively very effective.

Efficacy of a bifurcated endograft versus open repair of abdominal aortic aneurysms: a reappraisal

OBJECTIVE

Late complications and graft failures have recently cast serious doubts on the durability of endovascular repair of abdominal aortic aneurysms (AAA). The results of a multicenter trial comparing a bifurcated endograft (AB) with standard open repair (OR) were reviewed to assess the late findings of both methods of AAA treatment.

PATIENTS AND METHODS

In a multicenter study of AB versus OR conducted from December 1995 to February 1998, 242 patients with AAA successfully treated with an AB and 111 control patients treated concurrently with OR were followed up at least yearly. Twenty-five immediate conversions were excluded from late follow-up. All imaging modalities obtained during follow-up were reviewed by a core laboratory for AAA size, endoleaks, migration, and device integrity. Clinical outcomes at the yearly visits were compared. All death reports were reviewed to classify the cause of death.

RESULTS

Average follow-up for the AB group was 36 months, with 194 patients at 3 years and 55 patients at 4 years. The cumulative mortality rate was similar between the AB (15.7%) and OR groups (12.6%; P =.59). The significant early benefit to the AB group in cardiopulmonary complications was no longer evident by 3 years. However, the AB advantage in total and bowel complications, as well as the higher renal complication rates, persisted. At 3 years, 73.7% of patients showed a significant reduction of their AAA size, whereas 25.7% still had an endoleak. One migration and two single hook fractures were noted. Graftrelated reinterventions were performed in 50 patients (20%) without any deaths. Twenty-eight patients (11.6%) underwent interventions for limb flow compromise, whereas 25 were treated for endoleak. Late conversion to OR was required in five patients (2%). No AAA ruptures were encountered in either group.

CONCLUSIONS

Rupture-free survival rates after treatment of AAA with the bifurcated AB are similar to those of the OR group. Notably the proximal attachment system is relatively stable and the AAA shrinks in three of four patients treated. Reinterventions are nonetheless required in nearly one of five patients. Although most late procedures are percutaneous, counseling regarding possible future interventions is necessary.

Multicentre retrospective analysis of the outcome of artificial anal sphincter implantation for severe faecal incontinence

BACKGROUND

A new prosthetic device, the Action artificial anal sphincter, has recently been introduced for treating severe faecal incontinence. The results of this procedure in 28 patients are presented.

METHODS

The patients underwent operation for severe faecal incontinence in four Italian university hospitals and patients were reviewed after a median follow-up of 19 (range 7-41) months.

RESULTS

Early infections occurred in four patients, requiring removal of the device in three. Dehiscence of the perineal wound occurred in nine patients. After activation of the device, the cuff had to be removed in a further four patients (for rectal erosion in two, anal pain in one and late infection in one). The cuff was accidentally broken in one patient. A new anal cuff was repositioned successfully in two patients. Overall, five patients had complete removal of the device and two removal of the cuff only. Twenty-one patients available for long-term evaluation had a major improvement in faecal continence. Median resting anal pressure increased from 27 mmHg before surgery to 32 mmHg after operation. Preoperative squeeze pressure was 42 mmHg while maximum postoperative anal pressure with the activated device was 67 mmHg. The median American Medical System incontinence score decreased significantly from 98.5 to 5.5 (P < 0.001). Similar figures were observed using the Continence Grading Scale (from 14.9 to 2.6; P < 0.001). Twelve patients developed symptoms of obstructed defaecation while two patients complained of anal pain.

CONCLUSION

Improved continence was achieved after neosphincter implantation in three-quarters of the patients. Early infection and rectal erosion, together with difficulty in evacuating, are still major concerns with this technique.

Continued benefit of coronary stenting versus balloon angioplasty: five-year clinical follow-up of Benestent-I trial

OBJECTIVES

This study sought to establish whether the early favorable results in the Benestent-I randomized trial comparing elective Palmaz-Schatz stent implantation with balloon angioplasty in 516 patients with stable angina pectoris are maintained at 5 years.

BACKGROUND

The size of the required sample was based on a 40% reduction in clinical events in the stent group. Seven months and one-year follow-up in this trial showed a decreased incidence of restenosis and clinical events in patients randomized to stent implantation.

METHODS

Data at five years were collected by outpatient visit, via telephone and via the referring cardiologist. Three patients in the stent group and one in the percutaneous transluminal coronary angioplasty (PTCA) group were lost to follow-up at five years. Major clinical events, anginal status and use of cardiac medication were recorded according to the intention to treat principle.

RESULTS

No significant differences were found in anginal status and use of cardiac medication between the two groups. In the PTCA group, 27.3% of patients underwent target lesion revascularization (TLR) versus 17.2% of patients in the stent group (p = 0.008). No significant differences in mortality (5.9% vs. 3.1%), cerebrovascular accident (0.8% vs. 1.2%), myocardial infarction (9.4% vs. 6.3%) or coronary bypass surgery (11.7% vs. 9.8%) were found between the stent and PTCA groups, respectively. At five years, the event-free survival rate (59.8% vs. 65.6%; p = 0.20) between the stent and PTCA groups no longer achieved statistical significance.

CONCLUSIONS

The original 10% absolute difference in TLR in favor of the stent group has remained unchanged at five years, emphasizing the long-term stability of the stented target site.

Pre-MRI procedure screening: recommendations and safety considerations for biomedical implants and devices

Maintaining a safe MR environment is a daily challenge for MR healthcare workers, especially in consideration of the increasing number of clinical MR applications and the large and growing variety of biomedical implants and devices that are currently used in patients. This review article presents policies and procedures that should be used to screen all patients and individuals before allowing them to enter the magnetic resonance (MR) environment. Information pertaining to MR safety and the relative risk factors for implants, devices and materials is discussed. A comprehensive pre-MRI procedure screening form that is recommended for use by MR facilities is also included.

Deformation of femoral nails with intramedullary insertion

Current methods of distal interlocking of intramedullary femoral nails are dependent on image intensification. However, radiation exposure to the patient, the operating room staff, and the surgeon remains a concern. Proximally mounted, radiation-free aiming systems for distal interlocking of femoral nails have reportedly failed because of nail deformation with insertion. To better understand this deformation, a three-dimensional magnetic motion tracking system was used to determine the position of the distal interlocking hole following nail insertion. The amount and direction of deformation of commercially available small-diameter implants (unslotted 9-mm nails inserted without reaming) and large-diameter implants (slotted 13-mm nails inserted with reaming) from a single manufacturer were analyzed. Measurements of deformation (three translations and three angles), based on the center of the distal transverse locking hole, were performed on 10 paired intact human cadaveric femora before and after insertion. The technique produced the following results for the small and large-diameter nails, respectively: lateral translations of 18.1+/-10.0 mm (mean+/-SD, range: 47.8 mm) and 21.5+/-7.9 mm (range: 26.4 mm), dorsal translations of -3.1+/-4.3 mm (range: 15.2 mm) and 0.4+/-9.8 mm (range: 30.1 mm), and rotation about the longitudinal axes of -0.1+/-0.2 degrees (range: 0.7 degrees) and 10.0+/-3.1 degrees (range: 7.8 degrees). This technique is useful for measuring insertion-related femoral nail deformation. The data for the nails tested suggest that a simple aiming arm, mounted on the proximal end of the femoral nail alone, will not sufficiently provide accurate distal aiming.

Factors associated with implantation of single- versus dual-chamber pacemakers in 1992

Characteristics of hospitalized patients receiving initial pacemaker implantation were determined using a multistate inpatient discharge database. Analysis revealed a significant association of pacemaker type with patient age and income level, even after controlling for diagnostic factors.

Medical devices; retention in class III and effective date of requirement for premarket approval for three preamendments class III devices--FDA. Proposed rule; opportunity to request a change in classification

The Food and Drug Administration (FDA) is proposing to retain in class III, three preamendments class III medical devices, and is proposing to require the filing of a premarket approval application (PMA) or a notice of completion of a product development protocol (PDP) for these devices. FDA believes that the suction antichoke device, the tongs antichoke device, and the implanted neuromuscular stimulator device should remain in class III because insufficient information exists to determine that special controls would provide reasonable assurance of their safety and effectiveness, and/or these devices present a potential unreasonable risk of illness or injury. The agency is summarizing its proposed findings regarding the degree of risk of illness or injury designed to be eliminated or reduced by requiring the devices to meet the statute's approval requirements and the benefits to the public from the use of the devices. In addition, FDA is announcing the opportunity for interested persons to request the agency to change the classification of any of the devices based on new information.