Surgical Placement Research Articles

Abstract 12264: A Rare Case of Penetrating Aortic Ulcer Causing Hemopericardium and Its Management

Introduction: Penetrating Aortic Ulcer (PUA) is an atherosclerotic lesion with ulceration that penetrates the internal elastic lamina and allows hematoma formation within the medial layer of the aortic wall. As per our literature review, only one case of PUA causing hemopericardium has been reported. Case Presentation 66-year-old male with an unknown past medical history was bought in by the emergency medical services following a cardiac arrest. Initial rhythm was pulseless electrical activity and return of spontaneous circulation was achieved after ten mins of cardio-pulmonary resuscitation on the field. Initial echocardiogram was significant for a 4.6 cm ascending aorta with large hemopericardium causing tamponade physiology. CT chest with contrast revealed an ectatic ascending aorta with mild irregularity along the posteromedial wall, concerning for aortic leak secondary to a penetrating aortic ulcer (as indicated by the yellow arrow in the image below). Controlled pericardiocentesis was planned as a bridging therapy while awaiting transfer to a specialized cardiothoracic unit. But, the systolic blood pressure (SBP) rose to 170 mmHg when the chest tube was first inserted, worsening the hemopericardium. The patient's condition rapidly deteriorated, causing another cardiac arrest and death. Discussion The recommended treatment for Type A and B PUA-associated Intra Mural Hematoma is urgent surgical aortic graft placement. For hemodynamically unstable patients who cannot be taken for urgent surgery, The 2015 European Society of Cardiology guidelines recommend controlled pericardiocentesis to maintain a target SBP of 90 mmHg as a temporary measure. Conclusion In addition to aortic dissection, PAU should be considered in the differentials of patients with dilated ascending aorta and hemopericardium. An acute rise in blood pressure above 90 mmHg during pericardiocentesis is associated with worsening tamponade.

Surgical and Image-Guided Percutaneous Peritoneal Dialysis Catheter Placement Associated With Similar Outcomes: A Single-Center Retrospective Study in Canada

Surgical and Image-Guided Percutaneous Peritoneal Dialysis Catheter Placement Associated With Similar Outcomes: A Single-Center Retrospective Study in Canada

Percutaneous vs. Surgical Catheter Placement in Subjects With ESKD Referred Late to Start of Peritoneal Dialysis

Percutaneous vs. Surgical Catheter Placement in Subjects With ESKD Referred Late to Start of Peritoneal Dialysis

Breast Fat Grafting: 10-Year Learned Clinical Experience

Our being strives for staying youthful and being beautiful. Beauty for woman encompasses the entire body from the face, down to the breasts, the torso, buttocks, and extremities. Breast enhancement using implants is consistently ranked as one of the most common aesthetic surgical procedure undertaken by woman. However, as alloplastic implants suffer numerous potential complications and revision surgery, some practitioners and patients seek alternative treatment. Autologous fat grafting has gained popularity due to its safety and scientific advances yielding increased adipocyte survival. The low complication rate and valuable cosmetic outcomes will continue to have patients request natural breast augmentation. The authors’ more than 12 years of clinical experience with autologous fat transfer to the breast is presented. Advances in fat processing, enrichment, and administration are highlighted. The addition of stem cells, stromal vascular fraction, and platelet-rich plasma (PRP) is elucidated during the clinical experience. Laboratory evaluation of fat survival comparing ultrasound- and suction-assisted fat harvesting is presented. A comparison of 2 distinct fat processing methods is done using both clinical evaluation by the patients and surgeon, and the use of diagnostic ultrasound to assess fat thickness before and after surgical placement. The filtration device (Puregraft, Solana Beach, California) was compared with the Lipokit or filtration, centrifugation device (Medi-Khan USA, Inc., Los Angeles, California). Breast fat grafting was used for sole breast augmentation, after silicone breast implant surgery, in conjunction with mammopexy surgery, and reconstruction after breast cancer surgery or explantation. The authors’ observation with breast fat grafting volumetric outcomes has seen an increase from about 30% to almost 80%. This increased volume is related to the placement of a purer fat graft with less wetting solution fluid with less blood and oil. Minimizing ultrasound energy during the harvesting, lower suction levels, short fat storage times of 1 to 2 hours prior to administration, purification of fat without washing away growth factors, and the enrichment of fat with fat-derived autologous stem cells and blood-derived PRP have been observed techniques to optimize fat survival. Breast fat grafting using much of the current knowledge of harvesting, processing, enrichment, and administration has yielded superior adipocyte survival. This increased survival has provided more consistent breast enhancement results.

Anaesthesia for vascular emergencies - a state of the art review.

In this state-of-the-art review, we discuss the presenting symptoms and management strategies for vascular emergencies. Although vascular emergencies are best treated at a vascular surgical centre, patients may present to any emergency department and may require both immediate management and safe transport to a vascular centre. We describe the surgical and anaesthetic considerations for management of aortic dissection, aortic rupture, carotid endarterectomy, acute limb ischaemia and mesenteric ischaemia. Important issues to consider in aortic dissection are extent of the dissection and surgical need for bypasses in addition to endovascular repair. From an anaesthetist's perspective, aortic dissection requires infrastructure for massive transfusion, smooth management should an endovascular procedure require conversion to an open procedure, haemodynamic manipulation during stent deployment and prevention of spinal cord ischaemia. Principles in management of aortic rupture, whether open or endovascular treatment is chosen, include immediate transfer to a vascular care centre; minimising haemodynamic changes to reduce aortic shear stress; permissive hypotension in the pre-operative period; and initiation of massive transfusion protocol. Carotid endarterectomy for carotid stenosis is managed with general or regional techniques, and anaesthetists must be prepared to manage haemodynamic, neurological and airway issues peri-operatively. Acute limb ischaemia is a result of embolism, thrombosis, dissection or trauma, and may be treated with open repair or embolectomy, under either general or local anaesthesia. Due to hypercoagulability, there may be higher numbers of acutely ischaemic limbs among patients with COVID-19, which is important to consider in the current pandemic. Mesenteric ischaemia is a rare vascular emergency, but it is challenging to diagnose and associated with high morbidity and mortality. Several peri-operative issues are common to all vascular emergencies: acute renal injury; management of transfusion; need for heparinisation and reversal; and challenging postoperative care. Finally, the important development of endovascular techniques for repair in many vascular emergencies has improved care, and the availability of transoesophageal echocardiography has improved monitoring as well as aids in surgical placement of endovascular grafts and for post-procedural evaluation.

Noninvasive and Invasive Renal Hypoxia Monitoring in a Porcine Model of Hemorrhagic Shock.

Up to 50% of patients with trauma develop acute kidney injury (AKI), in part due to poor renal perfusion after severe blood loss. AKI is currently diagnosed based on a change in serum creatinine concentration from baseline or prolonged periods of decreased urine output. Unfortunately, baseline serum creatinine concentration data is unavailable in most patients with trauma, and current estimation methods are inaccurate. In addition, serum creatinine concentration may not change until 24-48 h after the injury. Lastly, oliguria must persist for a minimum of 6 h to diagnose AKI, making it impractical for early diagnosis. AKI diagnostic approaches available today are not useful for predicting risk during the resuscitation of patients with trauma. Studies suggest that urinary partial pressure of oxygen (PuO2) may be useful for assessing renal hypoxia. A monitor that connects the urinary catheter and the urine collection bag was developed to measure PuO2 noninvasively. The device incorporates an optical oxygen sensor that estimates PuO2 based on luminescence quenching principles. In addition, the device measures urinary flow and temperature, the latter to adjust for confounding effects of temperature changes. Urinary flow is measured to compensate for the effects of oxygen ingress during periods of low urine flow. This article describes a porcine model of hemorrhagic shock to study the relationship between noninvasive PuO2, renal hypoxia, and AKI development. A key element of the model is the ultrasound-guided surgical placement in the renal medulla of an oxygen probe, which is based on an unsheathed optical microfiber. PuO2 will also be measured in the bladder and compared to the kidney and noninvasive PuO2 measurements. This model can be used to test PuO2 as an early marker of AKI and assess PuO2 as a resuscitative endpoint after hemorrhage that is indicative of end-organ rather than systemic oxygenation.

Adapting a simple surgical manual tool to a 3D printed implantology protocol: the use of a universal screwdriver for fixation of custom-made laser sintered titanium subperiosteal implants

PurposeCurrent paper aims to describe a simple technique used for the fixation of the screws of a customized implant via a universal screw driver (BoneTrust® Easy Screw according to Dr. Bayer, Medical Instinct®, GmbH, Germany) to simplify the surgical placement of the customized implants.MethodsThe insertion of the drilling screws for the retention of the implant with angulated handpiece into the palatinal region or zygomatic buttress were performed with universal screw driver.ResultsThe retention screws could be inserted with a proper angulation without interfering with the surrounding tissues. The technique described herein has significantly simplified the surgical intervention.ConclusionThe insertion of the drilling screws for the retention of the implant with angulated handpiece into the palatinal region or zygomatic buttress could be challenging, thus the anatomical structures and the insufficient length of the handpiece could interfere with the placement of the screw with a proper angulation. This problem could be easily managed with the use of universal screw driver.

Bicruciate-Retaining Total Knee Arthroplasty: State of the Art for the Younger and Active Population? A Systematic Review and Future Prospective

(1) Background: Total knee arthroplasty (TKA) is a well-established surgical treatment for end-stage osteoarthritis. While no leading factor can be identified, the high frequency of patient dissatisfaction (20%) pertains to several key features such as preoperative expectations and postoperative improvement in knee function. Bicruciate-retaining total knee arthroplasty (BCR-TKA) may improve kinematics and lead to improved clinical outcome in the higher-demanding patients. (2) Methods: A systematic review of the literature was performed to assess the best available preclinical and clinical literature on BCR-TKA for kinematics and clinical outcome and adverse events such as implant loosening. Articles were screened using predefined in- and exclusion criteria. The guidelines for Preferred Reporting Items for Systematic Reviews and Meta-analysis (PRISMA) were used. (3) Results: The literature search resulted in 352 articles which were screened for title and abstract. After application of the in- and exclusion criteria, 13 preclinical and 30 clinical articles were included. The methodological quality of studies was low, including mainly level IV studies. (4) Conclusions: This is the first report that provides a systematic description of the broad available preclinical and clinical literature on BCR-TKA. It underlines the current interest in improving kinematics and clinical outcome based on a more anatomical TKA design. The current review demonstrates the low methodological quality of clinical trials that have investigated BCR-TKA. Currently, there are insufficient data to support broad (“state of the art”) implantation of BCR-TKA. Preclinical and clinical research suggest, however, that the design has a potential benefit to achieve improved kinematics in the young and active arthroplasty patient and warrants future research for new-generation designs with optimal (tibial) fixation and reproducible (robot or navigated) surgical placement.

Propensity Score-Matched Analysis of Revisional/Conversional Roux-en-Y Gastric Bypass vs Sleeve Gastrectomy in Patients with Hypoalbuminemia

INTRODUCTION: Hypalbuminemia (HA) may place patients at increased risk when undergoing revisional/conversional bariatric surgery. The primary aim of this study was to assess complication in patients with HA undergoing Roux-en-Y gastric bypass (RYGB) and sleeve gastrectomy as revisional/conversional bariatric surgery. METHODS: Revisional/conversional bariatric procedures were extracted from the MBSAQIP database from 2015 to 2019. Nearest neighbor 1:1 propensity score matching (PSM) was performed on 23 covariates with E analysis to assess point estimate confounding. Outcomes were assessed via bivariate analysis and univariate regression. RESULTS: There were 4,825 revisional/conversional patients with HA who underwent the RYGB (n = 2,636) or sleeve gastrectomy (n = 2,189) procedure. PSM yielded 1,928 patient pairs with no difference in perioperative demographics. Matched patients who underwent the RYGB procedure were more likely to be readmitted within 30 days (9.18% vs 5.45%; p < 0.001, E = 2.07), have longer procedure time (137 minutes, interquartile range [IQR] 101–185] vs 93 minutes IQR [68–130]; p < 0.001), a reoperation (3.58% vs 1.61%; p < 0.001, E = 2.32), unplanned ICU admission (2.39% vs 0.99%; p = 0.001, E = 2.22), nonadmitting emergency room visit (8.04% vs 5.08%; p < 0.001, E = 1.83), and anastomotic leak complication (2.70% vs 1.40%; p = 0.007, E = 1.74). Patients who underwent RYGB procedure also had a higher incidence of surgical drain placement (36.10% vs 24.43%; p < 0.001, E = 2.41) and postoperative organ space infection (1.30% vs 0.57%; p = 0.03, E = 1.50). (Figure) CONCLUSION: Patients with HA who undergo a revisional/conversional operation are at increased risk of serious postoperative complication, and RYGB revisional/conversional procedures represent a higher-risk group for certain complications.Figure

Mouse models and human islet transplantation sites for intravital imaging.

Human islet transplantations into rodent models are an essential tool to aid in the development and testing of islet and cellular-based therapies for diabetes prevention and treatment. Through the ability to evaluate human islets in an in vivo setting, these studies allow for experimental approaches to answer questions surrounding normal and disease pathophysiology that cannot be answered using other in vitro and in vivo techniques alone. Intravital microscopy enables imaging of tissues in living organisms with dynamic temporal resolution and can be employed to measure biological processes in transplanted human islets revealing how experimental variables can influence engraftment, and transplant survival and function. A key consideration in experimental design for transplant imaging is the surgical placement site, which is guided by the presence of vasculature to aid in functional engraftment of the islets and promote their survival. Here, we review transplantation sites and mouse models used to study beta cell biology in vivo using intravital microscopy and we highlight fundamental observations made possible using this methodology.

Trainee doctors’ perceptions of the surgeon stereotype and its impact on professional identification: a qualitative study

BackgroundThe demography of the medical profession is changing as more women join the workforce. Traditional assumptions about the personal qualities required to be a successful surgeon may change as more women join the specialty. While exploring the attitudes and beliefs of doctors in their second ‘Foundation’ year of post-graduate training (FY2) about their choice of specialty, evidence emerged about how the stereotype of the surgeon influences professional identification and beliefs about person-specialty fit.MethodsQualitative telephone interviews with 24 FY2 doctors, 17 women and 7 men, in South-West England.ResultsMany participants reported exposure to stereotypes about the personal qualities desirable in a surgeon. Senior doctors and other trainees were the primary source of these stereotypical views. Experience on surgical placements could either reinforce stereotypes or challenge them, the latter particularly where senior surgeons provided positive role models. As more women enter the surgical specialties, they are increasingly challenging the traditional stereotype and sub-culture.ConclusionGendered stereotypes about surgical roles persist, and for some this can hinder professional identification with the role. Positive role models and mentoring can encourage and support women who are interested a surgical career to identify with the role, but there is a need for a broader debate encompassing job redesign and surgical identities.

Incidence and risk factors of bacterial sepsis and invasive fungal infection in neonates and infants requiring major surgery: an Italian multicentre prospective study

Limited data are currently available on the incidence rates and risk factors for bacterial sepsis and invasive fungal infections (IFIs) among neonates and infants undergoing major surgery. To assess the incidence of bacterial sepsis and IFI, fungal colonization, risk factors for sepsis, and mortality in neonates and infants aged <3 months undergoing major surgery. A multicentre prospective study was conducted involving 13 level-3 neonatal intensive care units in Italy, enrolling all infants aged ≤3 months undergoing major surgery. From 2018 to 2021, 541 patients were enrolled. During hospitalization, 248 patients had a bacterial infection, and 23 patients had a fungal infection. Eighty-four patients were colonized by fungal strains. Overall, in-hospital mortality was 2.8%, but this was higher in infected than in uninfected infants (P= 0.034). In multivariate analysis, antibiotic exposure before surgery, ultrasound-guided or surgical placement of vascular catheters, vascular catheterization duration, and gestational age ≤28 weeks were all associated with bacterial sepsis. The risk of IFI was markedly higher in colonized infants (odds ratio (OR): 8.20; P < 0.001) and was linearly associated with the duration of vascular catheterization. Fungal colonization in infants with abdominal surgery increased the probability of IFI 11-fold (OR: 11.1; P < 0.001). Preventive strategies such as early removal of vascular catheters and the fluconazole prophylaxis should be considered to prevent bacterial and fungal sepsis in infants undergoing abdominal surgery, and even more so in those with fungal colonization.

Combining Awake Anesthesia with Minimal Invasive Surgery Optimizes Intraoperative Surgical Spinal Cord Stimulation Lead Placement.

Spinal cord stimulation (SCS) is an effective and validated treatment to address chronic refractory neuropathic pain in persistent spinal pain syndrome-type 2 (PSPS-T2) patients. Surgical SCS lead placement is traditionally performed under general anesthesia due to its invasiveness. In parallel, recent works have suggested that awake anesthesia (AA), consisting of target controlled intra-venous anesthesia (TCIVA), could be an interesting tool to optimize lead anatomical placement using patient intra-operative feedback. We hypothesized that combining AA with minimal invasive surgery (MIS) could improve SCS outcomes. The goal of this study was to evaluate SCS lead performance (defined by the area of pain adequately covered by paraesthesia generated via SCS), using an intraoperative objective quantitative mapping tool, and secondarily, to assess pain relief, functional improvement and change in quality of life with a composite score. We analyzed data from a prospective multicenter study (ESTIMET) to compare the outcomes of 115 patients implanted with MIS under AA (MISAA group) or general anesthesia (MISGA group), or by laminectomy under general anesthesia (LGA group). All in all, awake surgery appears to show significantly better performance than general anesthesia in terms of patient pain coverage (65% vs. 34–62%), pain surface (50–76% vs. 50–61%) and pain intensity (65% vs. 35–40%), as well as improved secondary outcomes (quality of life, functional disability and depression). One step further, our results suggest that MISAA combined with intra-operative hypnosis could potentialize patient intraoperative cooperation and could be proposed as a personalized package offered to PSPS-T2 patients eligible for SCS implantation in highly dedicated neuromodulation centers.

Evaluating the role of subacromial impingement in rotator cuff tendinopathy: development and analysis of a novel rat model.

Subacromial impingement of the rotator cuff caused by variations in acromial anatomy or altered glenohumeral kinematics leads to inflammation and degeneration of the rotator cuff, ultimately contributing to the development of tendinopathy. However, the underlying cellular and molecular changes in the impinged tendon remain poorly understood. Because the rat is an accepted model for rotator cuff studies, we have developed a rat model to study rotator cuff tendinopathy. Forty-four adult male Sprague-Dawley rats were allocated to one of 4 study groups: intact control group (group 1, n=11); bilateral subacromial surgical clip placement to induce supraspinatus impingement for 2 weeks (group 2, n=11), 4 weeks (group 3, n=11), and 8 weeks (group 4, n=11). Bilateral shoulder specimens were harvested for biomechanical testing, histology, and quantitative real-time polymerase chain reaction (qRT-PCR) analysis. Radiography confirmed that all microvascular clips remained in stable position in the subacromial space. Gross inspection of supraspinatus tendon specimens in the impingement groups revealed changes in tendon morphology at the enthesis and midsubstance. Biomechanical evaluation demonstrated decreased supraspinatus tendon failure force and tissue stiffness at all time points compared with control tendons. Semiquantitative scoring of histologic specimens demonstrated significant, persistent tendinopathic changes over 8 weeks. qRT-PCR analysis of impinged tendon specimens demonstrated upregulation of gene expression for Col3 and Mmp14 in the impingement groups compared with control groups. In muscle samples, significant upregulation was seen in the expression of genes that are commonly associated with muscle atrophy (MuRF1 and Ube2b) and fatty infiltration (Fabp4, Pparg2, and Klf15). This newrat subacromial impingement model creates cellular and molecular changes consistent with the development of rotator cuff tendinopathy. The results of this study may serve as a baseline for future investigation.

Outcomes of Transcatheter Pulmonary Valve Replacement and Surgical Pulmonary Valve Replacement: A Cohort Analysis.

Transcatheter pulmonary valve replacement (TPVR) has become an alternative to surgical pulmonary valve placement (SPVR) for patients after tetralogy of Fallot repair. This study compared the outcomes of TPVR with those of SPVR. We reviewed data from patients who underwent pulmonary valve replacement with a median of 2 years of follow-up. Between 2010 and 2021, 215 patients underwent pulmonary valve replacement (72 TPVR and 143 SPVR). The median size of the right ventricular end-diastolic volume index in the TPVR group was 165 mL/m2 (IQR, 136-190) and 184 mL/m2 (IQR, 163-230) in the SPVR group (P = .001). The median value of the maximum landing zone at the right ventricular outflow tract (RVOT) in patients with native RVOT was 26 mm (IQR, 24-28) in the 43 patients in the TPVR group and 31 mm (IQR, 28-34) in the 101 patients in the SPVR group (P < .001). The median size of the pulmonary valve implant for the native RVOT in the TPVR group was 29.0 mm (IQR, 26.0-29.0) and 24.0 mm (IQR, 24.0-24.0) in the SPVR group (P < .001). There were no deaths in the TPVR group and 8 deaths in the SPVR group (P = .041). Major complications and the length of hospitalization were lower in the TPVR group (P = .001). After 2 years, the mean decrease in QRS duration was 5 milliseconds (IQR, 1-14) in the TPVR group and 1 millisecond (IQR, -4 to 10) in the SPVR group (P = .006). TPVR allows for larger implants, resulting in lower mortality, shorter hospital stays, and fewer major cardiac events. SPVR may be preferable in patients with larger (>30 mm) native RVOT and in those who require concomitant surgical procedures.

520 Augmented Reality (AR) Presents a Novel Approach to Improving Surgical Training for Medical Students

Abstract Aim Surgical specialities are underrepresented in medical schools with students often feeling that anatomy teaching is suboptimal. Augmented reality (AR) presents a novel approach of improving anatomical knowledge. This study aims to evaluate AR as a method of preparing students for their surgical placements through a series of surgeon-led anatomy tutorials. Method The Microsoft HoloLens 2 was used to project a 3D anatomical model and deliver small group renal anatomy tutorials, with a focus on transplant surgery. Questionnaires and MCQs were completed by participants before and after tutorials, assessing key themes of anatomical knowledge, self-perception of renal anatomy knowledge and a comparison of AR to traditional methods. All responses were anonymised, and qualitative feedback evaluated u­­sing a 5-point Likert scale. Results Nineteen medical students, from a variety of year groups, were recruited from a single medical school. 63% were in their 4th year of study. Average MCQ results improved by 18% before and after the tutorial. Self-perceived confidence regarding renal anatomy improved from 2/10 pre-tutorial to 8/10 post-tutorial. 95% of students preferred AR teaching ­to traditional methods such as slide-based teaching. 85% preferred it over dissection-based methods. Technical limitations of the HoloLens were discovered during the study and nearly half of participants reported some symptoms of cybersickness. Conclusions AR based anatomy tutorials offer a more interactive and engaging experience than traditional methods and are positively received by medical students. As an adjunct alongside traditional methods, AR offers innovative opportunities of improving anatomy education and surgical training within medical schools.

1002 Improving the Medical Student Experience of Trauma and Orthopaedic Education – a Quality Improvement Project

Abstract Aim The medical student experience of clinical placements is closely linked with quality of teaching, varied educational opportunities and sense of belonging within the team. Surgical rotations such as Trauma and Orthopaedics (T&amp;O) have a stereotype for being challenging. At a London teaching hospital student satisfaction of T&amp;O placements was low (8% satisfaction) as assessed by feedback. This quality improvement (QI) project aimed to improve the quality of educational experiences and overall student satisfaction in T&amp;O. Method Student feedback from end of placement evaluation forms from academic years 2016–19 was reviewed. A QI driver diagram was created based on the themes raised in the feedback. These were 1) formal teaching, 2) structure and organisation, 3) curriculum content and 4) student engagement and belonging. Each theme was subdivided into multiple achievable strategies to improve student experience while on T&amp;O placements. This included allocated clinic and theatre sessions, bedside teaching, named tutors, curriculum map, WhatsApp communication and a dedicated clinical teaching fellow in the department. Results As a result of the implemented QI strategies, student satisfaction improved over the subsequent semesters to 100%, 89%, 100% and 75%, with a greater number of students providing feedback. Conclusions The project achieved greater student satisfaction of T&amp;O education and improved the student experience of surgical placements. It also validates student feedback as a valuable tool in developing surgical education.

Surgical guides for flapless dental implant placement and immediate definitive prosthesis installation by using selective laser melting and sintering for 3D metal and polymer printing: A clinical report

Integration between the phases of computer-based guided dental implant surgery can be used to optimize oral rehabilitation. Two new surgical guides prepared by using the 3D metal and polymer printing technology are presented for immediate implant loading and definitive fixed prosthesis construction in flapless dental implant surgery. Nine implants and 2 fixed prostheses were installed in 2 completely edentulous adult patients by using a metallopolymer surgical guide with a metal central bar attached to a polymer seal or a metal guide. Virtual planning was used to design the 3D printed surgical guides, which were then constructed by using selective laser sintering (SLM) and selective laser melting (SLS). The 3D printed surgical guides oriented the surgical placement of the implants and were welded to the abutments and attached to the denture framework. The technique allowed implants and prostheses to be installed on the same day.

Success rates and safety of a modified percutaneous PD catheter placement technique: Ultrasound-guided percutaneous placement of peritoneal dialysis catheters using a multifunctional bladder paracentesis trocar.

Background:We modified the blind Seldinger technique by incorporating ultrasound guidance and the use of a multifunctional bladder paracentesis trocar for PD catheter (PDC) placement, which can be easily performed by a nephrologist and is a feasible technique. To compare success rates and safety of our modified percutaneous PD catheter placement technique to open surgery.Methods:Two hundred and twelve stage-5 chronic kidney disease(CKD) patients receiving PD therapy from June 2016 to June 2019 were included, 105 patients treated by ultrasound-guided percutaneous placement of peritoneal dialysis catheters using a multifunctional bladder paracentesis trocar (Group A) and 107 patients receiving open surgical placement (Group B). Outcomes of patients via either catheter placement technique were retrospectively compared. The clinical success rate as defined by proper catheter drainage within 4 weeks after placement, complication rates (both technical complications and infections), and 1-year catheter survival were compared.Results:There was no significant difference in sex ratio, age, or previous abdominal surgery history between groups (P > .05). Both surgical time and incision length were significantly shorter in Group A than in Group B (P < .05). Clinical success rate was also higher inGroup A (P < .05). Moreover, Group A demonstrated lower overall complication rates (P < .05) and lower incidence rates of early peritonitis, initial drainage disorder, and peritubular leakage (all P < .05). One-year catheter survival was also higher in Group A (P < .05).Conclusion:Percutaneous placement of PD catheters using our modified technique demonstrates superior success rates and safety compared to open surgery. In addition, our modified technique can be a better alternative to traditional Seldinger percutaneous catheterization for its higher success rate and safety, more accurate positioning.

Monitoring orthodontic tooth movement in rats after piezocision by bone scintigraphy.

Piezocision, corticocision of mineralized tissue by ultrasound showed promising results in accelerating tooth movement induced by orthodontic appliances although the biologic effects of this procedure are not well-understood so far. The aim of this study was to investigate the impact of piezocision on bone remodeling in rats by bone SPECT imaging. Ten male Wistar rats underwent surgical placement of orthodontic appliances on each side of the maxilla followed by piezocision on one side only. Each rat underwent 99mTc-MDP bone SPECT/CT imaging before surgery (T0), and 2 (T1) and 4 weeks (T2) after surgery. Bone uptake is expressed as median [IQR] min-max in percentage of the injected activity per ml computed from the 10 voxels with the highest uptake (%IAmax10/ml). Pooled data regardless of the piezocision showed a significant increase in bone uptake from T0 (3.2 [2.8-3.9] 2.6-4.9) to T1 (4.4 [3.8-4.6] 3.4-4.8; p = 0.001). Thereafter, the uptake decreased to T2 (3.8 [3.1-4.4] 2.8-4.8; p = 0.116). No significant differences in bone uptake were found between the maxilla sides without and with piezocision: T1: without (4.3 [3.8-4.5] 3.4-4.8) vs. with (4.5 [3.7-4.6] 3.5-4.7; p=0.285), T2: without (4.0 [3.1-4.5] 2.8-4.8) vs. with (3.7 [3.0-4.4] 2.8-4.8; p=0.062). 99mTc-MDP bone SPECT imaging in rats was able to reproduce changes in bone uptake in the maxilla after placement of orthodontic appliances inducing measurable tooth movement. An additional effect of piezocision on bone remodeling in terms of bone uptake was not detectable which is probably due to the pronounced and significant effects induced by the orthodontic appliances per se, which may mask the potential effects of additional piezocision.