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.

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.

Long-lasting hyporesponsivenss induced by the 23-valent pneumococcal polysaccharide vaccine (PPV23) in asplenic patients with β-thalassemia major

We have previously shown that multiple vaccinations with 23-valent pneumococcal polysaccharide vaccine (PPV23s) resulted in attenuated antibody responses to subsequent 7-valent conjugate vaccine (PCV7) in asplenic adults with β-thalassemia major (Orthopoulos et al. Vaccine 2009; 27:350). However, there is evidence that PPV23-induced immune hyporesponsiveness could be overcome with time (Papadatou et al. Clin Infect Dis 2014; 59:862). In the current study we investigate the duration of hyporesponsiveness in the same cohort seven years after the original study vaccinations. Patients received one dose of 13-valent conjugate vaccine (PCV13) and antibody levels were measured before and one month after vaccination. Antibodies increased significantly after vaccination with PCV13, but were lower than post-PCV7 seven years earlier. Lower pre-vaccination antibody levels were associated with more robust response to PCV13. Our findings suggest that PPV23 should be used cautiously in asplenic adults vaccinated with multiple PPV23s in the past. Measurement of anti-pneumococcal antibodies before and after vaccination could be used to optimise timing of vaccinations and certify vaccine immunogenicity in such individuals.

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.

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.

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.

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.