Artificial lens replacement in own experiences. What determines the success of this procedure?

The article describes the author’s experiences related to the replacement of an artificial lens with a different model. Reasons for the procedure are described and attention is paid to the stages of lens removal that may affect the final result of the procedure. Lens replacement procedures were performed by one surgeon in the period from one month to over 6 years from the initial implantation procedure. Calcification, glistening and subsequent opacification of the artificial lens are among the main reasons for removing an artificial lens after several years. Removal of the lens in a short time, up to 15 months, resulted from the desire to see without glasses to far and near distances, the presence of a residual defect, and the quality of vision unacceptable to the patient related to the implantation of a premium class lens. The presence of secondary cataract greatly facilitates the lens replacement process.

Experience with periprosthetic infection after limb salvage surgery for patients with osteosarcoma

Background The rate of postoperative infection developing is higher after limb salvage surgery (LSS) following sarcoma resection compared with conventional arthroplasty. The goal of this study is to summarize our experience in management of periprosthetic joint infection (PJI) and the risk factors of early PJI after LSS. Methods Between January 2010 and July 2019, 53 patients with osteosarcoma in the lower extremities who encountered periprosthetic infection after segmental tumor endoprosthetic replacement in our center were analyzed. Detailed patient characteristics and therapeutic information were collected from database of our institution or follow-up data and we divided patients according to the interval time between infection and tumor resection (surgery-infection interval) and investigate potential risk factors. Results A total of 53 (5.08%) patients were suffered postoperative infection. The average interval between surgery and clinical signs of deep infections are 27.5 days. For the drainage culture, positive results were only presented in 11 patients (20.8%). Almost half of this study’s (47.2%) patients underwent a traditional two-stage revision, that was, after the removal of the infected prosthesis, we applied antibiotic-loaded bone cements as a spacer. The mean blood loss during initial implantation surgery and operation time both correlated with interval period between PJI and initial implantation significantly (P = 0.028, P = 0.046). For several patients which infection marker was hardly back to normal after spacer implantation, we conservatively introduced an improved combination of bone cement and prosthesis for the second-stage surgery (5.6%). There were six patients needing re-operation, of which three were due to the aseptic loosening of the prosthesis, one developed periprosthetic infection again, and two patients encountered local recurrence and underwent amputation. Two patients were dead from distal metastasis. Conclusions A two-stage revision strategy remains effective and standardized methods for PJI patients. Total operation time and blood loss during LSS of osteosarcoma are the main risk factors of early PJI. For the patients without confirmed eradiation of microorganisms, an improved combination of bone cement and prosthesis applied in the second-stage surgery could achieve satisfied functional and oncologic results.

Case series of late lead dislodgement of Medtronic SelectSecure 3830 pacing leads in growing paediatric patients

Background The SelectSecure lumenless 3830 pacing lead is often considered to be the pacing lead of choice for transvenous pacing in children because of its small diameter, lead strength, and reliable long-term sensing and pacing characteristics. One of the potential long-term pitfalls of a sturdy pacing lead is relative retraction with growth in children resulting in late lead dislodgement.Case summary We report two cases of late SelectSecure 3830 lead dislodgement at 11.8 years (Case 1) and 8.8 years (Case 2), respectively, post the initial implantation. Case 1 was diagnosed with congenital complete heart block (CHB) at 9 months old when he presented with unconfirmed diphtheria infection. Case 2 was diagnosed with CHB at 14 weeks of age with positive maternal anti-Ro antibodies. Both patients underwent implantation of a transvenous permanent pacemaker implantation with Medtronic SelectSecure 3830 lead due to symptomatic bradycardia. Apart from a pulse generator change at 8.5 years (Case 1) and 7 years (Case 2), respectively, post-implant due to normal battery depletion, both patients are well in the interim.Discussion As part of the pacemaker follow-up for rapidly growing children, we recommend more frequent surveillance of lead ‘tautness’ by chest radiography especially in children with CHB with no underlying heart rhythm.

The Half-Century Mark: Explant of Ball and Cage Valve after 50 Years

This is a case report of a 69-year-old man with chronic hemolysis and worsening diastolic heart failure, secondary to known periprosthetic leak, who underwent a reoperative mitral valve replacement 50 years following initial implantation of a Starr–Edwards ball and cage valve.

Removable cranial window for sustained wide-field optical imaging in mouse neocortex

Attempts to image neocortical regions on the surface of mouse brain typically use a small glass disc attached to the cranial surface. This approach, however, is often challenged by progressive deterioration in optical quality and permits limited tissue access after its initial implantation. Here we describe a design and demonstrate a two-stage cranial implant device developed with a remarkably versatile material, polydimethylsiloxane, which facilitates longitudinal imaging experiments in mouse cortex. The system was designed considering biocompatibility and optical performance. This enabled us to achieve sustained periods of optical quality, extending beyond a year in some mice, and allows imaging at high spatio-temporal resolution using wide-field microscopy. Additionally, the two-part system, consisting of a fixed headplate with integrated neural access chamber and optical insert, allowed flexible access to the underlying tissue offering an expansive toolbox of neuromanipulation possibilities. Finally, we demonstrate the technical feasibility of rapid adaptation of the system to accommodate varying applications requiring long-term ability to visualize and access neural tissue. This capability will drastically reduce wasted time and resources for experiments of any duration, and will facilitate previously infeasible studies requiring long-term observation such as for research in aging or the progression chronic neurological disorders.

Mean 6-Year Follow-up of Magnetically Controlled Growing Rod Patients With Early Onset Scoliosis: A Glimpse of What Happens to Graduates

BACKGROUNDThere is no agreement on frequency of distractions of magnetically controlled growing rods (MCGRs) but more frequent and smaller amounts of distractions mimic physiological spine growth. The mid- to long-term follow-up and management at skeletal maturity is unknown.OBJECTIVETo analyze patients with mean 6 yr of follow-up and describe the fate of MCGR graduates.METHODSEarly onset scoliosis (EOS) patients treated with MCGRs with minimum 4 yr of follow-up and/or at graduation were studied. Parameters under study included Cobb angle, spine and instrumented lengths, and rod distraction gains. Relationship between timing of rod exchanges with changes in rate of lengthening was studied.RESULTSTen EOS patients with mean 6.1 yr of follow-up were studied. The greatest Cobb angle correction occurred at the initial implantation surgery and was stable thereafter. Consistent gains in T1-12, T1-S1, and instrumented segment were observed. Rate of lengthening reduced after the first year of use but improved back to initial rates after rod exchange. Seven of the ten patients experienced complications with reoperation rate of 40% for rod distraction failure and proximal foundation problems. Only mild further improvements in all radiological parameters were observed pre- and postfinal surgery. No clinically significant curve progression was observed for rod removal only. All postfinal surgery parameters remained similar at postoperative 2 yr.CONCLUSIONThis study provides an outlook of the end of MCGR treatment. Although this is a fusionless procedure, instrumented segments do experience stiffness limiting further correction and length gain during final surgery whether fusion or rod removal is performed.

Quantification of Subdural Electrode Shift Between Initial Implantation, Postimplantation Computed Tomography, and Subsequent Resection Surgery

BACKGROUND Subdural electrodes are often implanted for localization of epileptic regions. Postoperative computed tomography (CT) is typically acquired to locate electrode positions for planning any subsequent surgical resection. Electrodes are assumed to remain stationary between CT acquisition and resection surgery. OBJECTIVE To quantify subdural electrode shift that occurred between the times of implantation (Crani 1), postoperative CT acquisition, and resection surgery (Crani 2). METHODS Twenty-three patients in this case series undergoing subdural electrode implantation were evaluated. Preoperative magnetic resonance and postoperative CT were acquired and coregistered, and electrode positions were extracted from CT. Intraoperative positions of electrodes and the cortical surface were digitized with a coregistered stereovision system. Movement of the exposed cortical surface was also tracked, and change in electrode positions was calculated relative to both the skull and the cortical surface. RESULTS In the 23 cases, average shift of electrode positions was 8.0 ± 3.3 mm between Crani 1 and CT, 9.2 ± 3.7 mm between CT and Crani 2, and 6.2 ± 3.0 mm between Crani 1 and Crani 2. The average cortical shift was 4.7 ± 1.4 mm with 2.9 ± 1.0 mm in the lateral direction. The average shift of electrode positions relative to the cortical surface between Crani 1 and Crani 2 was 5.5 ± 3.7 mm. CONCLUSION The results show that electrodes shifted laterally not only relative to the skull, but also relative to the cortical surface, thereby displacing the electrodes from their initial placement on the cortex. This has significant clinical implications for resection based upon seizure activity and functional mapping derived from intracranial electrodes.