Intraoperative assessment of esophagogastric junction distensibility during per oral endoscopic myotomy (POEM) for esophageal motility disorders

Background

Per oral endoscopic myotomy (POEM) is a novel treatment for esophageal motility disorders such as achalasia. To date, the extent of the myotomy has been determined based on the subjective assessment of the endoscopist. We hypothesized that the real-time measurement of esophagogastric junction (EGJ) distensibility using a novel functional lumen-imaging probe would enable objective evaluation of POEM.

Methods

Patients diagnosed with achalasia disorders electively underwent POEM. Using impedance planimetry with a transorally inserted functional lumen-imaging probe (EndoFLIP^®), cross-sectional areas (CSA) and distensibilities at the EGJ were measured intraoperatively immediately before and after the transoral myotomy (n = 4). All patients completed their 6-month follow-up and two patients had repeat distensibility tests at this time. Four healthy volunteers served as a control group.

Results

POEM was successfully performed in all patients (4/4). Premyotomy measurements (40-ml fill mode) showed a median diameter of 6.5 mm (range = 5.2–7.9 mm) at the narrowest location of the EGJ and was 10.1 mm (7.3–13.2 mm) following POEM. CSA increased from 41.5 mm² (20–49 mm²) to 86 mm² (41–137 mm²) at a similar median intraballoon pressure (40.3 vs. 38.6 mmHg). The increased EGJ distensibility (DI, 1.0 vs. 2.4 mm²/mmHg) was comparable to that of healthy volunteers (2.7 mm²/mmHg).

Conclusion

Functional lumen distensibility measures show that POEM can result in an immediate correction of the nonrelaxing lower esophageal sphincter, which appears similar to that of healthy controls. Intraoperative EGJ profiling may be an important tool to objectively guide the needed extent and completeness of the myotomy during POEM.     

Relationship of Alignment and Tibial Cortical Coverage to Hypertrophic Bone Formation in Salto Talaris® Total Ankle Arthroplasty

A retrospective analysis of 107 Salto Talaris^® total ankle replacements was performed to determine the effect of alignment and tibial cortical coverage on the formation of heterotopic bone. The radiographic parameters were studied for at least 18 months to detect any changes over time. The angle of insertion of the implant was most often in varus and with a positive anterior slope. A slight increase was seen in the slope over time (p < .0001) but was not clinically relevant. The mean percentage of cortical coverage of the tibial component was 89%, and only 7 patients had complete coverage of both the anterior and the posterior cortices. The percentage of patients who had hypertrophic bone growth increased over time (p < .0001). As the slope of the implant increased, there was a negative correlation with the degree of tibial coverage (p = .007). There was also an increase in the extent of hypertrophic bone as the tibial coverage decreased. None of the patients had symptoms that required an additional surgical procedure. The results of the present study indicate a high incidence of hypertrophic bone proliferation when the dimensions of the tibial component do not match the anteroposterior depth of the tibia at the plane of resection. Despite the high occurrence rate, the clinical relevance of hypertrophic bone is obscure.     

The role of the dentate gyrus in the formation of contextual representations

The hippocampus is involved in encoding and integrating contextual information. Recently, it has been suggested that the dorsal dentate gyrus (dDG) hippocampal subregion may mediate the formation of contextual representations of the spatial environment through a conjunctive encoding process whereby incoming multimodal information is integrated into a single higher‐order representation. Despite anatomical evidence in support of this claim, behavioral evidence is limited. Therefore, a contextual associative learning paradigm was used to determine whether the dDG supports the formation of integrated contextual representations. Male Long‐Evans rats were randomly assigned as controls or to receive bilateral intracranial infusions of colchicine into the dDG. Following recovery from surgery, each rat was tested on an appetitive task that required animals to form an association between a cue (odor) and a context to receive a food reward. Each rat received 10 trials per day and was tested for 10 consecutive days. Upon completion of testing, animals were tested on an additional two‐choice olfactory and contextual discrimination task. The testing order was counterbalanced across animals. Results showed that control animals successfully acquired the contextual associative learning task for olfactory stimuli as indicated by improved performance across the 10 testing days. In contrast, animals with dDG lesions were impaired in the ability to acquire the odor‐context associations. Results from follow‐up odor and context discrimination tests indicated that both groups acquired the discriminations at similar rates. Therefore, it is unlikely that deficits in performance on the contextual associative learning task were due to an inability to discriminate between odors or contexts. The present findings provide further support for DG involvement in the formation of conjunctive contextual representations. © 2012 Wiley Periodicals, Inc.     

Personality and Psychological Factors as Predictors of Disordered Eating Among Female Collegiate Athletes

This article examined the relationship of perfectionism, psychological well-being (self-esteem and optimism), reasons for exercising and appearance orientation to eating disorder classification among 204 female collegiate athletes. Multivariate analyses showed that only self-esteem, exercising to improve appearance and be more attractive, and appearance orientation differentiated significantly between the symptomatic/eating disordered athletes and those who were asymptomatic. No differences existed between the two groups of athletes on perfectionism, optimism, or exercising for fitness/health. For athletes, self-esteem, appearance orientation and exercising to be attractive and improve appearance were most important for understanding their level of disordered eating.     

Immunization with heat-killed Francisella tularensis LVS elicits protective antibody-mediated immunity

Francisella tularensis (FT) has been classified by the CDC as a category A pathogen because of its high virulence and the high mortality rate associated with infection via the aerosol route. Because there is no licensed vaccine available for FT, development of prophylactic and therapeutic regimens for the prevention/treatment of infection is a high priority. In this report, heat-killed FT live vaccine strain (HKLVS) was employed as a vaccine immunogen, either alone or in combination with an adjuvant, and was found to elicit protective immunity against high-dose FT live vaccine strain (FTLVS) challenge. FT-specific antibodies produced in response to immunization with HKLVS alone were subsequently found to completely protect naive mice against high-dose FT challenge in both infection-interference and passive immunization experiments. Additional passive immunization trials employing serum collected from mice immunized with a heat-killed preparation of an O-antigen-deficient transposon mutant of FTLVS (HKLVS-OAg(neg)) yielded similar results. These findings demonstrated that FT-specific antibodies alone can confer immunity against high-dose FTLVS challenge, and they reveal that antibody-mediated protection is not dependent upon production of LPS-specific antibodies.