Navigation with the StealthStation™ in Skull Base Surgery: An Otolaryngological Perspective

The introduction of computer-assisted navigation systems has played a significant role in assuring the integration and consistent intraoperative use of radiological information. We used a frameless stereotactic navigation system to treat 62 patients with a variety of skull base pathologies. The optoelectric appliance uses digital imaging information to locate surgical instruments in the operative area. The aim of this study was to evaluate the clinical accuracy, practicality, and impact of this navigation system on otolaryngological procedures. In conjunction with rigid head fixation and bone-anchored registration markers, the precision of registration was 0.8 mm and the accuracy of clinical measurements was less than 2 mm. With conventional fiducials and flexible head positioning, deviations were as large as 4.5 mm. The additional use of surface registration increased the precision of registration. Preoperative preparations took 15 to 35 minutes, depending on the complexity of the planning. Intraoperative computer support is an important aid to a surgeon's orientation, especially when a patient's anatomy is atypical. Navigation systems will likely improve the quality of surgery and facilitate training.     

Percutaneous video choledochoscopic treatment of retained biliary stones via dilated T-tube tract

Background: Retained biliary stones is a common clinical problem in patients after surgery for complicated gallstone disease. When postoperative endoscopic retrograde cholangiopancreatography (ERCP) and endoscopic sphincterotomy are unsuccessful, several percutaneous procedures for stone removal can be applied as alternatives to relaparotomy. These procedures are performed either under fluoroscopic control or with the use of choledochoscopy, but it is also possible to combine these methods. Methods: Since 1994, we have used the percutaneous video choledochoscopic technique for the removal of difficult retained biliary stones via dilated T-tube tract in 17 patients, applying the technique of percutaneous stone extraction used in urology. While waiting for the T-tube tract to mature and after the removal of the T-tube, the dilatation of its tract was 26--30 Fr. Stone removal was carried out using a flexible video choledochoscope and a rigid renoscope under fluoroscopic control, with the aid of Dormia baskets, rigid forceps, and high-pressure irrigation. Results: We performed 23 operative procedures, and the clearance of the biliary ducts was successful in all cases. There were no major complications or deaths. Conclusion: Percutaneous video choledochoscopic--assisted removal of large retained biliary stones via the T-tube tract is a highly effective and safe procedure. Its advantages over other procedures include the ability to visualize the stones and noncalculous filling defects; it also guarantees that the stones can be removed under visual video endoscopic control. It has no problems related to tract or stone size. apd: 21 December 2000     

Immediate root canal disinfection with ultraviolet light: an ex vivo feasibility study.

OBJECTIVE: The study was designed to test application of ultraviolet light to root canal walls, as a mean of complementary immediate disinfection after the use of sodium hypochlorite. STUDY DESIGN: Root canals were infected ex vivo with Enterococcus faecalis for 48 hours. Non-attached bacteria were washed away, and the remaining attached bacteria were subjected to disinfection, with 5% sodium hypochlorite alone or followed by exposure to ultraviolet light (254 nm, 300 mJ/cm(2)). Root canals were then tested for remaining viable bacteria. Canals were obturated and tested again after 14 days. RESULTS: Sodium hypochlorite alone achieved negative cultures in only 47% of the cases, but 96% was achieved with sodium hypochlorite followed by ultraviolet light (P < .001). This status was also maintained after 14 days. CONCLUSIONS: Illumination of root canals with ultraviolet light may be an effective supplementary means to achieve immediate disinfection of infected root canals.     

Emergency room management of patients with blunt major trauma: evaluation of the multislice computed tomography protocol exemplified by an urban trauma center

BACKGROUND: The early clinical management of patients with major trauma still represents a challenge. To clinically evaluate the full extent of a patient's injuries is difficult, especially when the patient is unconscious. Before December 2002, trauma patients admitted to our emergency room (ER) underwent a diagnostic protocol including physical examination, conventional radiography (CR), sonography and further procedures if necessary. After the installation of a MSCT scanner, all trauma patients underwent the "MSCT protocol" immediately after admission. The aim of the study was to compare the "MSCT-protocol" as it is performed at our institution, with the "Pre-MSCT-protocol". METHODS: We compared 185 patients undergoing the "Pre MSCT-protocol" with 185 patients undergoing "MSCT protocol". We evaluated the efficacy, speed and accuracy of the "MSCT protocol" using several variables. Time periods from admission to the ER to admission to the intensive care unit were compared as well as outcome parameters such as length of ICU stay, ventilation period and rates of organ. Dichotomous data were analyzed by Chi-square analysis; continuous data were analyzed by Student's t test. Any values of p < 0.05 were considered significant for any test. RESULTS: No significant differences were found regarding demographic data. The full extent of injuries was definitively diagnosed after 12 +/- 9 minutes in 92.4% of the "MSCT protocol" cohort. In only 76.2% of "Pre-MSCT protocol" cohort definitive diagnosis was possible after 41 +/- 27 minutes. Total ER time was 104 +/- 21 minutes with the "Pre-MSCT protocol" and 70 +/- 17 minutes with "MSCT protocol" (p < 0.05). "Pre-MSCT protocol" patients had a significantly longer ICU stay than "MSCT protocol" patients (p < 0.05). "MSCT protocol" patients had significantly fewer ventilation days (14.3 vs. 10.9 days). Furthermore, rates of organ failure were lower in patients undergoing the "MSCT protocol". CONCLUSION: We could demonstrate that immediate MSCT in patients with blunt major trauma leads to more accurate and faster diagnosis, and reduction of early clinical time intervals. We also observed a reduction in ventilation, ICU, and hospital days, and in organ failure rates, though this might have been partly due to small differences in case mix. The "MSCT protocol" algorithm seems to be safe and effective.     

Quantitative analysis of EBV-specific CD4/CD8 T cell numbers, absolute CD4/CD8 T cell numbers and EBV load in solid organ transplant recipients with PLTD

Post transplant lymphoproliferative disease (PTLD) in solid organ transplant (SOT) recipients is assumed to be the result of impaired Epstein-Barr Virus (EBV)-specific cellular immunity. We analyzed the absolute CD4 and CD8 T cell counts as well as the EBV-specific CD4 and CD8 T cell responses in relation to EBV load in SOT recipients with PTLD. A prospective, single center study was initiated and 10 immunosuppressed patients with diagnosis of PTLD were analyzed and compared to 3 patients without PTLD (2 SOT recipients with EBV-reactivation, 1 patient with Infectious Mononucleosis) and 6 healthy EBV positive controls. EBV-specific CD8 T cells were enumerated using HLA class I tetramers and the IFN-gamma cytokine secretion assay. EBNA1-specific CD4 T cells were analyzed after protein stimulation and EBV load was quantified by real-time PCR. Absolute CD8 T cell counts were highly variable in all 19 cases analyzed. In contrast, the absolute EBV-specific CD8 T cell count was found to be low in 7/9 patients with PTLD (<5/microl whole blood). These frequencies were similar to absolute EBV-specific CD8 T cell numbers observed in healthy EBV positive donors, but much lower compared to patients with EBV reactivation but no PTLD. Absolute CD4 T cell counts were significantly lower in PTLD patients (mean: 336/microl+/-161 vs. controls 1008/microl+/-424, p=0.0001), with EBNA1-specific CD4 T cell responses being also low, but highly variable. Moreover, low absolute CD4 T cell counts (<230/microl) were associated with an elevated EBV load (>1000 copies/microg DNA). We conclude that SOT recipients with PTLD have an inadequate functional EBV-specific T cell response. Our data suggest that the frequency and function of circulating EBV-specific CD8 T cells are dependent on absolute CD4 T cell counts. Further studies are needed to verify if a low absolute CD4 T cell count presents a risk factor for the development of PTLD in SOT recipients.     

Cervical spine computed tomography utilization in pediatric trauma patients

Background

Guidelines for evaluating the cervical spine in pediatric trauma patients recommend cervical spine CT (CSCT) when plain radiographs suggest an injury. Our objective was to compare usage of CSCT between a pediatric trauma center (PTC) and referral general emergency departments (GEDs).

Methods

Patient data from a pediatric trauma registry from 2002 to 2011 were analyzed. Rates of CSI and CSCT of patients presenting to the PTC and GED were compared. Factors associated with use of CSCT were assessed using multivariate logistic regression.

Results

5148 patients were evaluated, 2142 (41.6%) at the PTC and 3006 (58.4%) at the GED. Groups were similar with regard to age, gender, GCS, and triage category. GED patients had a higher median ISS (14 vs. 9, p < 0.05) and more frequent ICU admissions (44.3% vs. 26.1% p < 0.05). CSI rate was 2.1% (107/5148) and remained stable. CSCT use increased from 3.5% to 16.1% over time at the PTC (mean 9.6% 95% CI = 8.3, 10.9) and increased from 6.8% to 42.0% (mean 26.9%, CI = 25.4, 28.4) at the GED. Initial care at a GED remained strongly associated with CSCT.

Conclusions

Despite a stable rate of CSI, rate of CSCT increased significantly over time, especially among patients initially evaluated at a GED.     

Treatment and outcome of traumatic biliary injuries in children

Background/Purpose

Traumatic biliary tract injuries in children are rare but may result in significant morbidity. The objective of this study was to review the occurrence of traumatic biliary tract injuries in children, management strategies, and outcome.

Methods

We conducted a retrospective review of patients with biliary tract injury using the trauma registry at our level 1 pediatric trauma center from 2002–2012.

Results

Twelve out of 13,582 trauma patients were identified, representing 0.09% of all trauma patients. All were secondary to blunt trauma. Mean age was 9.7 years [range 4–15], and mean Injury Severity Score was 31 ± 14, with overall survival of 92%. Biliary injuries included major ductal injury (6), minor ductal injury with biloma (4), gallbladder injury (2), and intrahepatic ductal injury (1). Major ductal injuries were managed by endoscopic retrograde cholangiopancreatography (ERCP) and biliary stent (5) and Roux-en-Y hepaticojejunostomy (1). Associated gallbladder injury was managed by cholecystectomy. In addition, the associated biloma was managed with percutaneous drainage (7), laparoscopic drainage (2), or during laparotomy (3). Two patients with ductal injuries developed late strictures after initial management with ERCP and stent placement. One of the two patients ultimately required a left hepatectomy, and the other has been managed conservatively without evidence of cholangitis. Two patients required placement of additional drains and prolonged antibiotics for superinfection following biloma drainage.

Conclusion

Biliary tract injuries are rare in children, and many are amenable to adjunctive therapy, including ERCP and biliary stent placement with or without placement of a peritoneal drain. Patients with a discrete ductal injury are at higher risk for stricture and require close follow up. Hepaticojejunostomy remains the definitive repair for large extrahepatic biliary tract injuries or transections.     

Cellular and molecular functions of hepatic stellate cells in inflammatory responses and liver immunology

The liver is a central immunological organ. Liver resident macrophages, Kupffer cells (KC), but also sinusoidal endothelial cells, dendritic cells (DC) and other immune cells are involved in balancing immunity and tolerance against pathogens, commensals or food antigens. Hepatic stellate cells (HSCs) have been primarily characterized as the main effector cells in liver fibrosis, due to their capacity to transdifferentiate into collagen-producing myofibroblasts (MFB). More recent studies elucidated the fundamental role of HSC in liver immunology. HSC are not only the major storage site for dietary vitamin A (Vit A) (retinol, retinoic acid), which is essential for proper function of the immune system. This pericyte further represents a versatile source of many soluble immunological active factors including cytokines [e.g., interleukin 17 (IL-17)] and chemokines [C-C motif chemokine (ligand) 2 (CCL2)], may act as an antigen presenting cell (APC), and has autophagy activity. Additionally, it responds to many immunological triggers via toll-like receptors (TLR) (e.g., TLR4, TLR9) and transduces signals through pathways and mediators traditionally found in immune cells, including the Hedgehog (Hh) pathway or inflammasome activation. Overall, HSC promote rather immune-suppressive responses in homeostasis, like induction of regulatory T cells (Treg), T cell apoptosis (via B7-H1, PDL-1) or inhibition of cytotoxic CD8 T cells. In conditions of liver injury, HSC are important sensors of altered tissue integrity and initiators of innate immune cell activation. Vice versa, several immune cell subtypes interact directly or via soluble mediators with HSC. Such interactions include the mutual activation of HSC (towards MFB) and macrophages or pro-apoptotic signals from natural killer (NK), natural killer T (NKT) and gamma-delta T cells (γδ T-cells) on activated HSC. Current directions of research investigate the immune-modulating functions of HSC in the environment of liver tumors, cellular heterogeneity or interactions promoting HSC deactivation during resolution of liver fibrosis. Understanding the role of HSC as central regulators of liver immunology may lead to novel therapeutic strategies for chronic liver diseases.     

Left subclavian artery stenting: an option for the treatment of the coronary-subclavian steal syndrome

Introduction

The subclavian steal syndrome is characterized by the vertebral artery flow inversion, due to a stenotic lesion in the origin of the subclavian artery. The Coronary-subclavian Steal Syndrome is a variation of the Subclavian Steal Syndrome and is characterized by inversion of flow in the Internal Thracic artery that has been used as conduct in a myocardial revascularization. Its diagnosis must be suspected in patients with difference in pulse and arterial pressure in the upper limbs, that present with angina pectoris and that have done a myocardial revascularization. Its treatment must be a surgical bypass or a transluminal angioplasty.

Objective

The objective is to show the left subclavian artery stenting as a safe and effective method to treat the coronary-subclavian steal syndrome.

Methods

Historical prospective, non-randomized trial, through revision of the hospital records of the patients treated with the stenting of the left subclavian artery, from January 2006 to September 2012.

Results

In the mentioned period, 4.291 miocardial revascularizations were performed with the use of the left mammary artery, and 16 patients were identified to have the Coronary-subclavian steal syndrome. All of them were submitted to endovascular treatment. The success rate was 100%; two patients experienced minor complications; none of them presented with major complications. Eleven of the 16 patients had ultrassonographic documentation of patent stent for at least one year; two patients lost follow up and other two died.

Conclusion

The stenting of the left subclavian artery is a good option for the treatment of the Coronary-subclavian Steal Syndrome, with high level of technical and clinical success.