Standardization of Intraoperative Neuromonitoring of Recurrent Laryngeal Nerve in Thyroid Operation

Background  

The lack of standardized procedures of intraoperative neuromonitoring (IONM) during thyroid operations may lead to highly variable results, and many of these results can cause misleading information and, conversely, increase the risk of recurrent laryngeal nerve (RLN) injury. Therefore, standardization of IONM procedures is necessary.     

Platelets in Early Antibody-Mediated Rejection of Renal Transplants

Antibody-mediated rejection is a major complication in renal transplantation. The pathologic manifestations of acute antibody-mediated rejection that has progressed to functional impairment of a renal transplant have been defined in clinical biopsy specimens. However, the initial stages of the process are difficult to resolve with the unavoidable variables of clinical studies. We devised a model of renal transplantation to elucidate the initial stages of humoral rejection. Kidneys were orthotopically allografted to immunodeficient mice. After perioperative inflammation subsided, donor-specific alloantibodies were passively transferred to the recipient. Within 1 hour after a single transfer of antibodies, C4d was deposited diffusely on capillaries, and von Willebrand factor released from endothelial cells coated intravascular platelet aggregates. Platelet-transported inflammatory mediators platelet factor 4 and serotonin accumulated in the graft at 100- to 1000-fold higher concentrations compared with other platelet-transported chemokines. Activated platelets that expressed P-selectin attached to vascular endothelium and macrophages. These intragraft inflammatory changes were accompanied by evidence of acute endothelial injury. Repeated transfers of alloantibodies over 1 week sustained high levels of platelet factor 4 and serotonin. Platelet depletion decreased platelet mediators and altered the accumulation of macrophages. These data indicate that platelets augment early inflammation in response to donor-specific antibodies and that platelet-derived mediators may be markers of evolving alloantibody responses.     

Can Machine Learning Methods Produce Accurate and Easy-to-Use Preoperative Prediction Models of One-Year Improvements in Pain and Functioning After Knee Arthroplasty?

BackgroundApproximately 15%-20% of total knee arthroplasty (TKA) patients do not experience clinically meaningful improvements. We sought to compare the accuracy and parsimony of several machine learning strategies for developing predictive models of failing to experience minimal clinically important differences in patient-reported outcome measures (PROMs) 1 year after TKA.MethodsPatients (N = 587) in 3 large Veteran Health Administration facilities completed PROMs before and 1 year after TKA (92% follow-up). Preoperative PROMs and electronic health record data were used to develop and validate models to predict failing to experience at least a minimal clinically important difference in Knee Injury and Osteoarthritis Outcome Score (KOOS) Total, KOOS JR, and KOOS subscales (Pain, Symptoms, Activities of Daily Living, Quality of Life, and recreation). Several machine learning strategies were used for model development. Ten-fold cross-validation and bootstrapping were used to produce measures of overall accuracy (C-statistic, Brier Score). The sensitivity and specificity of various predicted probability cut-points were examined.ResultsThe most accurate models produced were for the Activities of Daily Living, Pain, Symptoms, and Quality of Life subscales of the KOOS (C-statistics 0.76, 0.72, 0.72, and 0.71, respectively). Strategies varied substantially in terms of the numbers of inputs required to achieve similar accuracy, with none being superior for all outcomes.ConclusionModels produced in this project provide estimates of patient-specific improvements in major outcomes 1 year after TKA. Integrating these models into clinical decision support, informed consent and shared decision making could improve patient selection, education, and satisfaction.Level of EvidenceLevel III, diagnostic study.     

Osteopontin inhibits macrophage nitric oxide synthesis to enhance tumor proliferation

BACKGROUND: Interactions between tumor cells and their host environment can play a major role in regulating survival programs required for tumor progression. Osteopontin (OPN) is a glycophosphoprotein overexpressed by tumors, and is a key molecule for tumor progression and metastasis. OPN also inhibits expression of autocrine and paracrine inducible nitric oxide synthase (iNOS). Given the cytotoxic effects of macrophage NO expression, we hypothesized that tumor-derived OPN inhibits expression of local macrophage iNOS to potentiate tumor survival. METHODS: We used a coculture system of murine CT26 colorectal cancer cells with RAW264.7 murine macrophage cells. CT26 expresses OPN at high levels. RNA interference was utilized to produce long-term specific silencing of OPN in CT26. RESULTS: Inhibition of constitutive OPN synthesis in CT26 upregulates local NO production with inhibition of CT26 proliferation and promotion of CT26 apoptosis. Macrophage iNOS expression is accompanied by increased binding activity of nuclear factor-kappaB DNA. When the CT26 culture media were examined for a panel of proinflammatory cytokines, elevated concentrations of granulocyte colony-stimulating factor (G-CSF) were found. Subsequently, in CT26 cells treated with antisense-G-CSF, NO levels in CT26-RAW cocultures were significantly decreased. CONCLUSION: In our system of CT26-RAW264.7 coculture, we conclude that inhibition of OPN synthesis in CT26 results in G-CSF-mediated induction of macrophage iNOS expression with resultant inhibition of CT26 proliferation via increased apoptosis. Our results suggest that tumor-derived OPN may enhance tumor survival by down regulating expression of NO in the local microenvironment. This is one mechanism by which OPN may potentiate cancer survival and progression.     

Evaluation of mandibular block using a standardized method.

The purpose of this prospective randomized study was to investigate the manifestations and efficiency of mandibular block (MB) using a standardized method. In this study, 123 patients requiring MB were randomly assigned to receive MB using a repeated measures design. Mandibular block was administered in each patient by using 2.1 mL of 2% lidocaine with 1:100 000 epinephrine for the inferior alveolar nerve, lingual nerve, and/or buccal nerve. Clinical parameters including the electric pulp test and test for soft tissue sensation using a sharp dental explorer were assessed on both the operated side and contralateral side before and 5, 10, and 15 minutes after injection, and at the end of surgical procedure. Results of the test of the contralateral tooth served as the control group. No response to the electric pulp test at a maximum output (80 readings) was used as the criterion for pulpal anesthesia. Results obtained with electric pulp test and sharp explorer test were not significantly different during various intervals on the contralateral side, indicating the reliability of this standardized method for assessing MB. The MB technique achieved a high rate of subjective numbness (100%) according to the perception of the patients of overall numbness and lip numbness. Overall anesthetic success rates of pulpal anesthesia were 5.7% for the central incisor, 38.2% for the canine, 55.3% for the first premolar, and 90.2% for the first molar. No significant difference was found in the efficiency of anesthesia related to sex or age of the patients. A slower onset of pulpal anesthesia after MB was found for the anterior teeth than for the posterior teeth. This study suggests that the use of a standardized method might produce a clearer and more comprehensive evaluation of the efficiency and manifestations of MB.     

Urinary nerve growth factor but not prostaglandin E2 increases in patients with interstitial cystitis/bladder pain syndrome and detrusor overactivity

Study Type – Aetiology (case series)
Level of Evidence 4

OBJECTIVE

To compare urinary nerve growth factor (NGF) and prostaglandin E2 (PGE2) levels among patients with detrusor overactivity (DO), increased bladder sensation (ISB), interstitial cystitis/bladder pain syndrome(IC/BPS) and controls.

PATIENTS, SUBJECTS AND METHODS

Urine samples were collected from 40 women with IC/BPS, 54 with overactive bladder (OAB) and 27 normal women as controls, all with a full bladder. Patients with OAB were further classified into subgroups of DO or IBS by urodynamic results. Urinary NGF and PGE2 levels were measured using an enzyme‐linked immunosorbent assay. Urinary NGF and PGE2 levels were normalized by urinary creatinine (Cr) levels and compared among all subgroups.

RESULTS

Urinary NGF levels were increased in the 40 women with IC/BPS and 23 with DO but not in 31 with IBS and the 27 controls. Mean (sd ) urinary NGF/Cr levels were not significantly different between patients with IC/BPS, at 1.35 (0.36), and DO, at 1.93 (0.77). Urinary NGF/Cr levels were significantly higher in women with IC/BPS than in women with IBS, at 0.25 (0.10) (P = 0.01). Using receiver operating characteristic curves for assessing urinary NGF/Cr levels in patients with IC/BPS and IBS, IC/BPS was diagnosed with a sensitivity and specificity of 75% and 65.5%, respectively, based on a urinary NGF/Cr threshold of 0.015. However, urinary PGE2/Cr levels were not significantly different among all subgroups.

CONCLUSIONS

Urinary NGF/Cr levels are elevated in women with IC/BPS or DO, but not in those with IBS. The differential diagnosis of women with IC/BPS from those with frequency‐urgency syndrome is possible based on urinary NGF/Cr levels but not urinary PGE2/Cr level.     

Comparison of video urodynamic results after the pubovaginal sling procedure using rectus fascia and polypropylene mesh for stress urinary incontinence

PURPOSE: Video urodynamic changes were compared after the pubovaginal sling procedure using rectus fascia or polypropylene mesh in women with stress urinary incontinence. MATERIALS AND METHODS: A total of 50 women with various types of stress urinary incontinence were treated with the pubovaginal sling procedure using randomly abdominal rectus fascia in 24 or polypropylene mesh in 26. The sling was placed at the level of the bladder neck and tied with sufficient tension to prevent urinary leakage without obstructing the bladder outlet. Video urodynamics were performed preoperatively, and 7 to 14 days and 3 to 6 months postoperatively in all cases. Surgical results and urodynamic changes after the pubovaginal sling procedure were compared in the 2 groups. Long-term results were evaluated at a mean followup of 2 years. RESULTS: Complete continence was achieved in 23 patients (95.8%) in the rectus fascia group and 26 (100%) in the polypropylene mesh group, including 1 initial failure with reoperation, at a median followup of 24 and 23 months, respectively. The subjective success rate was 91.6% for rectus fascia and 92.3% for polypropylene mesh. The main cause of dissatisfaction was persistent urge incontinence and dysuria in 2 cases each. In each group video urodynamics revealed a mild but nonsignificant decrease in maximum urinary flow and a significant increase in bladder neck opening time at 7 to 14 days versus baseline. However, these parameters returned to baseline within 3 to 6 months postoperatively. Voiding pressure, cystometric capacity and post-void residual urine also showed no significant change in either group after the pubovaginal sling procedure. Patients treated with a polypropylene mesh sling had a shorter operative time and hospital stay, a higher spontaneous voiding rate after catheter removal and a lower incidence of wound pain after surgery. One patient treated with polypropylene mesh had sling margin extrusion. The incidence of new onset detrusor instability and persistent dysuria was similar in the 2 groups. Transrectal sonography of the sling showed that it was located beneath the bladder neck and proximal urethra in all patients in each group. CONCLUSIONS: The results of this study show that the pubovaginal sling procedure using rectus fascia or polypropylene mesh as the sling material had similar effectiveness for treating female stress incontinence but the polypropylene group had more rapid recovery. Postoperatively video urodynamics demonstrated that the pubovaginal sling using either sling material did not cause bladder outlet obstruction with proper surgical technique.     

Crash severity, injury patterns, and helmet use in adolescent motorcycle riders

BACKGROUND: This study examined crash severity and injury patterns between helmeted and unhelmeted adolescent motorcycle riders. METHODS: Among an initial population of 4,721 junior college students, 1,284 students were involved in 1,889 motorcycle crashes during a 20-month follow-up period. Crash severity was measured by both the type of collision object and the repair cost of motorcycle damage. RESULTS: The incidence rates of crash, injury, hospitalization, and deaths per 1,000 person-years in the cohort were 358, 104, 14, and 1.3, respectively. Compared with helmeted riders, unhelmeted riders had more noncollisions and fewer collisions with a moving car but there was no significant difference in repair cost of motorcycle damage between these groups. More injuries to the external skin, face, and head and more severe injuries occurred in unhelmeted than in helmeted riders. Among crashes resulting in hospitalization/death, more injuries to the face and head occurred in unhelmeted riders than in helmeted riders. CONCLUSION: Crashes involving unhelmeted riders were not more severe but more frequently involved face and head injuries than crashes involving helmeted riders.     

Virtual reality: current urologic applications and future developments

The concept of virtual reality (VR) involves the computer generation of environments with which a user can interact directly. Virtual reality is now being used for medical applications, especially in the area of surgical simulation. As technology advances, VR simulation will play an important training role for both residents and urologists already in practice. This paper examines the history of VR, current developments, and its future implications for the field of urology.     

Concomitant ipsilateral pedicled fibular transfer and free muscle flap for compound tibial defect reconstruction.

Three patients with compound injuries of the lower extremities were treated with pedicle fibular grafts and a free muscle flap concomitantly. There were 1 female and 2 male patients, all of whom sustained high-energy trauma in a motor vehicle accident. The bone defect of the tibia ranged from 8 to 12 cm. The size of the soft-tissue defect ranged from 24 x 15 cm to 28 x 15 cm. All patients underwent preoperative angiography to ensure the patency of the peroneal artery and to avoid its use by risking viability of the leg. All patients were treated with an antegrade-flow pedicle fibular graft. The fibular graft was inserted as a single strut in 2 patients and as a double-barrel strut in 1 patient. The pedicle of the free muscle flap was anastomosed to the distal runoff of the fibular bone flap. All free muscle flap transfers succeeded without complication. Bone scans performed on postoperative day 7 showed viability of transferred bone. The average time to radiological union was 9 months, and the average time to full weight bearing was 12 months. Screw loosening occurred in 2 patients and osteomyelitis was noted in another patient who was treated successfully with sequestrectomy and antibiotics. Indications for this technique are a large segmental bone defect with a huge soft-tissue defect, and patency of the peroneal artery and at least one other major artery. This method provides the advantages of one-stage reconstruction, avoidance of contralateral donor site morbidity, easy control of infection, and chance for early weight bearing. When selected carefully, this technique can be considered when one wants to avoid a two-stage, two free flap transfer.