Accuracy of Full-Guided and Half-Guided Surgical Templates in Anterior Immediate and Delayed Implantation: A Retrospective Study

Computer-aided implantology has developed rapidly in recent years, this study aimed to compare the accuracy of guided-surgery between anterior immediate and delayed implantation, and simultaneously assess the effect of full-guided and half-guided templates on accuracy values. Seventy-six implants were inserted in 63 patients using full-guided or half-guided template in the anterior zone. Postoperative cone beam computed tomography (CBCT) was matched with preoperative planning to evaluate the deviation between actual and planned implants. No statistical difference was found in any deviation between immediate and delayed implantation (p > 0.05). In anterior immediate implantation, the global coronal, apical, depth and angular deviations of full-guided templates were all significantly lower than those of half-guided templates (0.66 ± 0.26 vs. 1.10 ± 0.76 mm, 0.96 ± 0.41 vs. 1.43 ± 0.70 mm, 0.46 ± 0.24 mm vs. 0.93 ± 0.79 mm and 1.69° ± 0.94° vs. 2.57° ± 1.57°). While in delayed implantation, full-guided templates only perform better with statistical significance on global apical and depth deviation (1.01 ± 0.42 vs. 1.51 ± 0.55 mm and 0.32 ± 0.26 vs. 0.71 ± 0.47 mm). After excluding the influence of depth deviation, the coronal and apical deviations between the two systems in immediate implantation and the apical deviations in delayed implantation had no statistical difference. Within the limit of this study, the results suggested the accuracy of guided-surgeries for anterior immediate and delayed implantations was comparable, and full-guided template was more accurate for immediate and delayed implantation.     

Un cas,une revue : thromboaspiration dans la prise en charge du SCA ST+

Routine manual thrombectomy during primary percutaneous coronary intervention might be intuitively justified. While older registers reported contradictory results, interventional cardiologists remained interested in using such devices during the mechanical treatment of acute myocardial infarction. The first studies were congruent to demonstrate a significant relationship between thromboaspiration and significant improvement of ST-segment elevation, lower distal embolization, despite TAPAS was the only to significantly reduce the mortality. Later studies were unable to confirm these promising data, avoiding routine manual thrombectomy prior to primary angioplasty to decrease cardiovascular mortality, recurrent myocardial infarction, cardiogenic shock or severe heart failure. Moreover, thrombectomy was associated with an increased rate of stroke. Should thrombectomy therefore be conclusively overlooked? It is presumably required to define which patient is eligible for thrombectomy, to define how to perfectly perform manual thrombectomy, to specify how to gently move towards the thrombus, the optimal pharmacological environment, the number of aspirations and the criterion to stop or to repeat aspiration. Indeed, while thrombectomy is nowadays scientifically downgraded, it remains of potential interest in numerous interventional cardiologists.     

Mechanical comparative analysis of stents for colorectal obstruction

The goal of this work is the mechanical comparison of different types of stents for colorectal obstructions. We consider self‐expanding and balloon‐expanding stents made of two different materials such as stainless steel and shape memory NiTi alloy. The mechanical parameters are expansion rate, shortening, radial compression resistance, longitudinal and perimetral adaptability, and buckling resistance. This analysis results in a better understanding of global mechanical behavior and also allows better design and device selection for colonic lesions.     

Influence of stent design on clinical outcome

Placement of a stent in a vessel involves damage to the endothelial cells (ECs) at the site of deployment as a result of the stent's radial and shearing forces, and by the obliteration of the vessel surface by the device itself. Part of the healing of the stent by the vessel wall involves restoration of the endothelial cover by migration and proliferation of ECs from adjacent patches of endothelium that survive the placement of the device. When the migrating ECs arrive at the device boundaries, physicochemical and topographical characteristics of the prosthetic surface influence interactions between the device and the ECs. The physicochemical characteristics of the material largely influence protein binding and molecular mechanisms involved in cell migration and attachment. The topographical characteristics influence ECs by altering local rheology, and by presenting a physical obstacle to the path of migrating cells. This paper focuses on the latter effect.     

Awake vs. Asleep Placement of Spinal Cord Stimulators: A Cohort Analysis of Complications Associated With Placement

Introduction: Patients will typically undergo awake surgery for permanent implantation of spinal cord stimulation (SCS) in an attempt to optimize electrode placement using patient feedback about the distribution of stimulation‐induced paresthesia. The present study compared efficacy of first‐time electrode placement under awake conditions with that of neurophysiologically guided placement under general anesthesia. Methods: A retrospective review was performed of 387 SCS surgeries among 259 patients which included 167 new stimulator implantation to determine whether first time awake surgery for placement of spinal cord stimulators is preferable to non‐awake placement. Results: The incidence of device failure for patients implanted using neurophysiologically guided placement under general anesthesia was one‐half that for patients implanted awake (14.94% vs. 29.7%). Conclusion: Non‐awake surgery is associated with fewer failure rates and therefore fewer re‐operations, making it a viable alternative. Any benefits of awake implantation should carefully be considered in the future.     

Subcutaneous Stimulation: How to Assess Optimal Implantation Depth

Introduction: Subcutaneous stimulation (peripheral nerve field stimulation) is a novel neuromodulation modality that has increased in its utilization during the last 10 years. It consists of introducing a lead in the subdermal level to stimulate the small nerve fibers in that layer. Unlike other neuromodulation techniques including direct peripheral nerve stimulation, spinal cord stimulation, or deep brain stimulation, the precise target is not identified. Materials and Methods: To date, there is no clear guideline on the appropriate depth or a method to achieve reproducibility of the appropriate depth to place these leads. From clinical experience, we have found that when electrodes are placed in a layer that is too superficial, stimulation is often painful or lacks efficacy. Further, if they are too deep, the patient may not feel adequate paresthesia or get uncomfortable stimulation including, in some circumstances, muscle contractions. Results: In this small series, we demonstrate a novel concept using a radiofrequency stimulation probe to identify the appropriate depth to place the lead. Reproducibility of results will add clarity to the accumulating data and hopefully increase the chances of adequate stimulation coverage and pain relief.