Expert laparoscopist performance on virtual reality simulation tasks with and without haptic features.

BACKGROUND: Virtual reality (VR) simulation for laparoscopic training is available with and without haptic feedback features. Currently, there is limited data on haptic feedback's effect on skill development. Our objective is to compare expert laparoscopists' skills characteristics using VR delivered laparoscopic tasks via haptic and nonhaptic laparoscopic surgical interfaces. METHODS: Five expert laparoscopists performed seven skills tasks on two laparoscopic simulators, one with and one without haptic features. Tasks consisted of 2-handed instrument navigation, retraction and exposure, cutting, electrosurgery, and complicated object positioning. Laparoscopists alternated platforms at default difficulty settings. Metrics included time, economy of movement, completed task elements, and errors. Progressive change in performance for the final three iterations were determined by repeated measures ANOVA. Iteration quartile means were determined and compared using paired t-tests. RESULTS: No change in performance was noted in the last three iterations for any metric. There were no significant differences between platforms on the final two quartiles for most metrics except avoidance of over-stretch error for retraction; and cutting task was significantly better with haptics on all iteration quartiles (p < 0.03). Economy of movement was significantly better with haptics for both hands for clip application (p < 0.01) and better for right hand on complex object positioning (p < 0.05). Accuracy was better with haptics for retraction and cutting (p < 0.05) and clip application (p < 0.05). CONCLUSION: Results showed higher performance in accuracy, efficient instrument motion, and avoidance of excessive traction force on selected tasks performed on VR simulator with haptic feedback compared to those performed without haptics feedback. Laparoscopic surgeons interpreted machine-generated haptic cues appropriately and resulted in better performance with VR task requirements. However, our results do not demonstrate an advantage in skills acquisition, which requires additional study.

Evaluation of Gastroesophageal Reflux Disease.

INTRODUCTION: Gastroesophageal reflux disease (GERD) may present with heartburn, regurgitation, dysphagia, chronic cough, laryngitis, or even asthma. The clinical presentation of GERD is therefore varied and poses certain challenges to the physician, especially given the limitations of the diagnostic testing. DISCUSSION: The evaluation of patients with suspected GERD might be challenging. It is based on the evaluation of clinical features, objective evidence of reflux on diagnostic testing, correlation of symptoms with episodes of reflux, evaluation of anatomical abnormalities, and excluding other causes that might account for the presence of the patient's symptoms. CONCLUSIONS: The diagnostic evaluation should include multiple tests, in addition to a thorough clinical examination.

Results of a Tailored Approach to Zenker's Diverticulum: A Single VA Experience.

The transoral division of the esophageal-diverticula septum with a linear stapler, with CO2 laser, or with harmonic scalpel under rigid endoscopy has revolutionized the surgical management of Zenker's diverticula. Nevertheless, the open approach still plays a role in select cases. Our goals are to illustrate the techniques and the results of our tailored approach to the surgical management of Zenker's diverticula in U.S. veterans.

The surgical management of achalasia in the morbid obese patient.

INTRODUCTION: Morbid obesity and achalasia may coexist in the same patient. The surgical management of the morbidly obese patient with achalasia is complex, and the most effective treatment still remains controversial. The goal of our report is to provide our evidence-based approach for the surgical management of the patient with achalasia and morbid obesity. RESULTS: Three main surgical approaches have been used for the concomitant treatment of morbid obesity and achalasia: 1) a laparoscopic Heller myotomy and a laparoscopic Roux-en-Y gastric bypass (LRYGB); 2) a laparoscopic Heller myotomy with bilio-pancreatic diversion; and 3) a laparoscopic Heller myotomy with a sleeve gastrectomy. Our approach of choice is the first one discussed, that is the laparoscopic Heller myotomy with a LRYGB, as this approach can provide excellent relief of symptoms and control of reflux while at the same time treating obesity and its comorbidities. CONCLUSIONS: Achalasia and obesity can coexist, albeit infrequently. A laparoscopic Heller myotomy with a LRYGB allows the simultaneous treatment of both diseases. When a morbidly obese patient with achalasia chooses to have a myotomy alone and not a LRYGB, a thorough discussion of the risks and benefits should occur and the autonomy of the patient's decision-making should be respected.

Capsular switching as a strategy to increase pneumococcal virulence in experimental otitis media model.

We hypothesized that capsular switch event, in which pneumococcus acquires a new capsule operon by horizontal gene transfer, may result in emergence of strains with increased virulence in acute otitis media. Using serotype 6A strain from a patient with invasive pneumococcal disease and clonally distant serotype 6C strain isolated from asymptomatic carrier we created 6A:6C (6A background with 6C capsule) capsular transformants and applied whole genome macro-restriction analysis to assess conservation of the 6A chassis. Next, we assessed complement (C3) and antibodies deposition on surface of pneumococcal cells and tested capsule recipient, capsule donor and two 6A:6C transformants for virulence in chinchilla experimental otitis media model. Both 6A:6C(1 or 2) transformants bound less C3 compared to 6C capsule-donor strain but more compared to serotype 6A capsule-recipient strain. Pneumococci were present in significantly higher proportion of ears among animals challenged with either of two 6A:6C(1 or 2) transformants compared to chinchillas infected with 6C capsule-donor strain [p < 0.001] whereas a significantly decreased proportion of ears were infected with 6A:6C(1 or 2) transformants as compared to 6A capsule-recipient strain. Our observations though limited to two serotypes demonstrate that capsular switch events can result in Streptococcus pneumoniae strains of enhanced virulence for respiratory tract infection.

Gunshot wounds to the face: emergency interventions and outcomes.

BACKGROUND: Gunshot wounds to the face (GSWF) may produce life-threatening injuries. Our objective is to describe outcomes of and factors related to interventions for urgent airway control (UAC) and urgent bleeding control (UBC) as well as to analyze complications associated with GSWF. METHODS: This was a retrospective study of 155 GSWF patients who were admitted to two Level 1 academic trauma centers over an 11-year period. Demographic details, injuries sustained, interventions performed, and timing of the interventions were recorded. Morbidity and mortality data were evaluated. RESULTS: Overall, 115 (74 %) patients suffered isolated GSWF, and none died. Of the 90 (58 %) patients requiring UAC, only three had a cricothyroidotomy. Of the 41 (26 %) patients requiring UBC, only four had angiographic embolization. Intraoral involvement and extrafacial injuries were associated with both UAC and UBC. Overall, 75 patients (48 %) required operations on the bones, eyes, or both. Complications developed in 14 and were treated successfully. CONCLUSIONS: UAC and UBC are required frequently after GSWF and are associated with intraoral involvement and injuries beyond the face. Simple methods, such as orotracheal intubation and packing, are typically sufficient for successful management. About half of the patients need further surgery, with infrequent morbidity.

The effect of 23-valent pneumococcal polysaccharide vaccine on immunological priming induced by 7-valent conjugate vaccine in asplenic subjects with beta-thalassemia.

The effect of the 23-valent pneumococcal polysaccharide vaccine (PPV) on the 7-valent conjugate (PCV) vaccine-induced priming was evaluated in 35 splenectomised beta-thalassemics [median (range) age: 30 (12-41) years] vaccinated with either PCV/PPV or two PCVs 1 month apart, followed by a PPV booster 12 months later. 28/35 had already received 1-3 PPVs in the past. Different schedules induced similar anamnestic responses; however priming for 3/5 serotypes induced by one or two PCVs, was inferior in subjects who had received > or =2 PPVs in the past when compared with 23 aged-matched PPV-naïve beta-thalassemics. One PPV following PCV does not affect PCV priming; multiple PPVs induce hyporesponsiveness for some serotypes in splenectomised subjects with beta-thalassemia.

TLR8 and TLR7 are involved in the host's immune response to human parechovirus 1.

Toll-like receptors (TLR) have a key role in regulating immunity against microbial agents. Engagement of TLR by bacterial, viral or fungal components leads to the production and release of inflammatory cytokines. In this study we show that mainly TLR8 and also TLR7 act as the host sensors for human parechovirus 1, a single-stranded RNA (ssRNA) virus. Furthermore, we see that the viral ssRNA genome is detected in endosomal compartments by these TLR, which activate signalling that lead to the synthesis of pro-inflammatory molecules by the host.

Human cardiac inflammatory responses triggered by Coxsackie B viruses are mainly Toll-like receptor (TLR) 8-dependent.

The group B coxsackieviruses are single-stranded RNA viruses that have been implicated in viral myocarditis. Viral infection of the myocardium, as well as the associated inflammatory response are important determinants of the virus-associated myocardial damage. Although these viruses are known as cytopathic viruses that cause death of the host cell, their viral RNA has been shown to persist in cardiac muscle contributing to a chronic inflammatory cardiomyopathy. Thus, it is essential that we understand the mechanism by which Coxasckie B viruses (CBVs) trigger this inflammatory response. In this study we investigated the involvement of Toll-like receptors (TLRs) in the recognition of CBV virions as well as CBV single-stranded RNA. Here we report that the CBV-induced inflammatory response is mediated through TLR8 and to a lesser extent through TLR7.

Coxsackie B viruses use multiple receptors to infect human cardiac cells.

Viral myocarditis is an inflammatory disease of the heart muscle that can be fatal. The primary viruses that have been linked to myocarditis and dilated cardiomyopathy are the human enteroviruses. The most common viruses associated with this disease are the Coxsackie B viruses and in particular Coxsackievirus B3 and Coxsackievirus B5. Early events in viral infection include attachment of the virus onto cell surface receptors. Even though, CD55 and Coxsackievirus adenovirus receptor protein (CAR) have been identified as receptors for Coxsackievirus B3, the exact mechanisms that Coxsackievirus B3 and B5 use to infect the cardiac muscle are not yet known. In this study, attempts were made to inhibit Coxsackievirus B3 and Coxsackievirus B5 infectivity of cardiac cells by using CAR and CD55 specific antibodies. The results show that these antibodies could not completely inhibit Coxsackievirus B3 and Coxsackievirus B5 binding or infectivity. Furthermore five new proteins have been identified that are used by Coxsackieviruses for binding to cardiac tissue and are distinct from CAR or CD55, leading us to believe that these viruses may use a different set of receptors for infection of cardiac muscle.