Measurement protocols and determinants of peak oxygen consumption in adults with Down syndrome: a systematic review

This systematic review aimed to provide an overview of test protocols used to measure peak oxygen uptake (VO2peak) in adults with Down syndrome (DS) and to determine how generalisable the outcomes are for the entire population of adults with DS by describing the sample characteristics of these studies and their impact on VO2peak. A literature search (PROSPERO CRD42022309560) was performed (18 July 2023) using the following databases: PubMed, CINAHL, APA PsycINFO, Web of Science, Embase and SPORTDiscus. For articles to be included, they had to be peer-reviewed pubications, reporting VO2peak or VO2max for individuals with DS separately, with a sample of n ≥ 5 and a mean age ≥18 years. Systematic reviews and meta-analyses were excluded but their reference lists were searched for additional papers to include. Studies were evaluated for risk of bias following the guidelines of Kmet et al. The results were summarised with frequency statistics. Forty-three studies were included in this systematic review. Sample sizes of included adults with DS ranged from n = 4-226, with a total of n = 1498 adults with DS being included. Most studies (29/43) used the same standardised maximal exercise treadmill protocol to measure VO2peak in adults with DS, and 33 out of 43 studies used at least one objective criterion to determine a valid maximal effort. Participants were predominantly male, under 40 years old, and overweight or obese. Additionally, the diversity of study samples was lacking or not reported. The most widely used, standardised, maximal exercise test treadmill protocol is recommended for future use in research and practice, including objective criteria to determine valid maximal effort. The current study samples are not representative of the population of adults with DS in terms of sex, age and diverse backgrounds and therefore likely overestimate VO2peak of this population.

The FLARE intraoperative near-infrared fluorescence imaging system: a first-in-human clinical trial in breast cancer sentinel lymph node mapping

BACKGROUND

Invisible NIR fluorescent light can provide high sensitivity, high-resolution, and real-time image-guidance during oncologic surgery, but imaging systems that are presently available do not display this invisible light in the context of surgical anatomy. The FLARE imaging system overcomes this major obstacle.

METHODS

Color video was acquired simultaneously, and in real-time, along with two independent channels of NIR fluorescence. Grayscale NIR fluorescence images were converted to visible "pseudo-colors" and overlaid onto the color video image. Yorkshire pigs weighing 35 kg (n = 5) were used for final preclinical validation of the imaging system. A six-patient pilot study was conducted in women undergoing sentinel lymph node (SLN) mapping for breast cancer. Subjects received (99m)Tc-sulfur colloid lymphoscintigraphy. In addition, 12.5 microg of indocyanine green (ICG) diluted in human serum albumin (HSA) was used as an NIR fluorescent lymphatic tracer.

RESULTS

The FLARE system permitted facile positioning in the operating room. NIR light did not change the look of the surgical field. Simultaneous pan-lymphatic and SLN mapping was demonstrated in swine using clinically available NIR fluorophores and the dual NIR capabilities of the system. In the pilot clinical trial, a total of nine SLNs were identified by (99m)Tc- lymphoscintigraphy and nine SLNs were identified by NIR fluorescence, although results differed in two patients. No adverse events were encountered.

CONCLUSIONS

We describe the successful clinical translation of a new NIR fluorescence imaging system for image-guided oncologic surgery.

Image-guided near-infrared fluorescent sentinel lymph node mapping in human breast cancer

e11591

Background: Breast cancer surgery is presently performed without real-time image-guidance. We have developed a novel optical imaging system for image-guided surgery that uses invisible near-infrared (NIR) fluorescent light to highlight structures on the surgical field with high sensitivity, specificity, and contrast. We have also performed the first human clinical trial of the imaging system in women undergoing SLN mapping for breast cancer. Methods: We used a portable imaging system with an articulating arm that has 6 degrees of freedom, high power LED light source, custom optics, custom software, and sterile drape. The imaging system provided simultaneous and real-time imaging of color video and NIR fluorescence at up to 15 frames per second. N = 6 women with biopsy- confirmed breast cancer undergoing SLN mapping gave informed consent. All subjects received conventional mapping with Tc-99m sulfur colloid using a handheld gamma probe as well as NIR fluorescence-guided SLN mapping using a mixture of indocyanine green (ICG) diluted to a final concentration of 10 μM in human serum albumin (ICG:HSA). Results: The imaging system was easy to position in the operating room, with the articulating arm providing 50” horizontal reach and 70” vertical reach. Working distance to the patient was 18”. NIR fluorescence excitation was 20 mW/cm2 at 760 nm. NIR-depleted white light was 40,000 lux. A total of 1.6 ml of ICG:HSA was injected intra-tumorally and peri-tumorally and the site massaged for 5 min. 8 of 9 SLNs identified by Tc- 99m sulfur colloid were also identified by NIR fluorescence. However, NIR fluorescence identified an SLN, confirmed to have cancer in it, that was not identified by Tc-99m sulfur colloid. These differences were consistent with asynchrony in the injection techniques. Unlike the gamma-ray probe, NIR fluorescence provided high-resolution, large area optical imaging of the surgical field, and helped guide surgical resection. Conclusions: In this 6-patient pilot study, a novel NIR fluorescence optical imaging system was used for the first time, and provided real-time image-guided surgery for SLN mapping of breast cancer.

No significant financial relationships to disclose.

Comparison of diffuse optical tomography of human breast with whole-body and breast-only positron emission tomography

We acquire and compare three-dimensional tomographic breast images of three females with suspicious masses using diffuse optical tomography (DOT) and positron emission tomography (PET). Co-registration of DOT and PET images was facilitated by a mutual information maximization algorithm. We also compared DOT and whole-body PET images of 14 patients with breast abnormalities. Positive correlations were found between total hemoglobin concentration and tissue scattering measured by DOT, and fluorodeoxyglucose (18F-FDG) uptake. In light of these observations, we suggest potential benefits of combining both PET and DOT for characterization of breast lesions.

An Augmented Reality system for MRI-guided needle biopsies

A navigation system can increase the speed and accuracy of MR guided interventions that make use of scanners with high-field closed magnets. We report on first needle placement experiments performed with an Augmented Reality (AR) navigation system. AR visualization provides very intuitive guidance, resulting in a faster procedure. The accuracy of the needle placement depends on the registration accuracy of the system. In the present trials, the needle was placed as good as 1mm close to the target center, however in a small number of cases substantially larger errors occurred and were most likely caused by needle bending.

Subtrochanteric fracture after fixation of slipped capital femoral epiphysis: a complication of unused drill holes

Subtrochanteric fracture of the femur has been infrequently reported after in situ fixation of slipped capital femoral epiphysis, and this occurred in only 1.4% of our patients over a 10-year period. As this technique is used more frequently, however, the incidence of this complication is likely to rise. All four subtrochanteric fractures occurred through unused drill holes, and avoiding extraneous screw holes seems to be the best way to prevent postoperative subtrochanteric fracture. Once subtrochanteric fracture occurs, immediate open reduction and internal fixation with a compression hip screw device is the recommended treatment.

Bausch & Lomb CW 79 aphakic extended wear contact lens: multi-year follow-up

We undertook a follow-up case study of 126 patients (146 eyes) to determine success rate and replacement rate of the Bausch & Lomb CW 79 aphakic extended wear contact lens. One hundred eighteen eyes (81%) were successful in wearing the contact lens, and 16 eyes (11%) were reported as contact lenses dropouts. Twelve eyes (8%) elected to receive intraocular lenses (IOLs). A total of 134 lenses were replaced, yielding a replacement rate of 0.3 lenses per eye per year. The average length of follow-up for successful patients was 3.7 years.

Osteoporotic correlates of alcoholism in young males

A group of 22 white males (ages, 28 to 40 years) with histories of chronic alcohol abuse ranging from 1 to 21 years were evaluated for trabecular bone mineral density in the left femoral neck area. A group of age and weight-matched white males with no history of alcoholism served as controls. All participants completed medical history questionnaires regarding fracture history, dietary habits, medications, and physical activity. Singh femoral trabecular indices also were measured for the alcoholic participants. Analysis of bone mineral data as measured by dual photon absorptiometry revealed no statistically significant reduction in the bone mineral densities of the alcoholic group when compared to the controls. No differences were seen in the areas of the femoral neck, Ward's triangle, and greater trochanter. Duration of alcoholism also was not correlated with the degree of osteopenia. Singh index measurements of right and left femoral heads were compared and revealed no significant differences within individual patients. Left femoral Singh index values averaged 5.5 (range, 4 to 6) for the alcoholic group and were not indicative of decreased bone mineral density. It is concluded from this study that chronic alcoholism associated with heavy smoking most likely has a debilitating effect on the trabecular bone density of white males, yet clinical and radiographic evidence is not widely manifested in men under the age of 40 years.