Assessment of microcirculatory changes in local tissue oxygenation after revascularization for peripheral arterial disease with the Hyperview®, a portable hyperspectral imaging device.

OBJECTIVES: The Hyperview® is a hyperspectral camera, which can be used to assess the microcirculation of patients with peripheral arterial disease (PAD) and/or diabetes mellitus (DM). It measures local tissue oxygenation in concentrations of oxyhemoblobin (OXY), deoxyhemoglobin (DEOXY), and O2-saturation (O2-SAT) in arbitrary units. The aim of this validation study is to assess whether the Hyperview® is able to monitor microcirculatory changes after revascularization in patients with PAD. METHODS: In this prospective observational cohort study, 50 patients with PAD were included who were scheduled for endovascular, hybrid, or open revascularization. The ankle-brachial index (ABI), systolic toe pressure (TP) (in case of DM), and a set of Hyperview® measurements of the plantar region were recorded before and after treatment. Changes in pre- and postoperative measurements were assessed with the paired t-test. RESULTS: Some 38 patients underwent endovascular revascularization and eight patients underwent hybrid or open vascular surgical revascularization. After revascularization, the ABI improved from 0.58 to 0.80 (p < 0.001). OXY increased from 72.6 to 77.8 (p = 0.134). DEOXY decreased from 69.1 to 55.0 (p < 0.001). O2-SAT increased from 51.3 to 58.1 (p < 0.001). TP improved from 50.6 to 61.9 mmHg (p = 0.065) but was measured in only 16 patients. CONCLUSION: The Hyperview® is able to observe changes in the microcirculation after revascularization in terms of DEOXY and O2-SAT. The results of this study are a promising step into the validation of the Hyperview®.

High inter- and intra-observer agreement for measuring tissue oxygenation of the plantar surface of the foot in healthy participants with the Hyperview®: A pilot study.

OBJECTIVES: The Hyperview® is a novel camera that applies hyperspectral imaging to project local concentrations of oxyhaemoglobin (OXY), deoxyhaemoglobin (DEOXY) and O2-saturation (O2-SAT) in a map. In this pilot validation study, we assessed inter - and intra-observer agreement for measuring OXY, DEOXY and O2-SAT in healthy participants. METHODS: The plantar region of the right foot was assessed with the Hyperview® in 50 healthy participants. Two consecutive pictures were taken by the same observer, followed by two images by a second observer. Measurements were performed without and with standardization (a static device for both the foot and the Hyperview camera). Inter- and intra-observer agreements were expressed as Intraclass Correlation coefficients (ICC) with their 95% confidence interval (CI). A score <0.40 indicates poor agreement, 0.40-0.59 fair, 0.60-0.74 good and 0.75-1.00 excellent agreement. Bland and Altman plots were also generated. RESULTS: Without standardization, the ICC values between the observers for OXY, DEOXY and O2-SAT ranged from 0.70 to 0.83. The intra-observer agreement of both observers ranged from 0.36 to 0.83. With standardization, the ICC values between the observers ranged from 0.80 to 0.82 and intra-observer agreement varied from 0.75 to 0.92. Four Bland and Altman plots were generated of the measurements of OXY by observers 1 and 2. CONCLUSIONS: When standardization is used, the Hyperview® camera is a reliable device with excellent intra- and inter-observer agreements for the assessment of OXY, DEOXY and O2-SAT. In future research, the inter- and intra-observer agreements of the camera should be investigated in patients with diabetes and/or peripheral arterial disease.

Effects of study methodology on adverse outcome occurrence and mortality.

PURPOSE: To assess the impact of variables related to setting, study design and definition on adverse outcome occurrence and mortality in hospitalized patients. DATA SOURCES: Pubmed and Embase. STUDY SELECTION: Articles in English from 1980 onwards, in non-selected patients or surgical patients only. DATA EXTRACTION: Data were extracted independently by two authors using a predefined form. Included study methodology variables were general variables such as setting, patient variables like age, study variables like number of reviewers and definition and the resulting adverse outcome occurrence and mortality. RESULTS: Eleven studies reporting on 76 617 non-selected patients and 18 studies representing 136 292 surgical patients were included. Adverse outcomes were estimated to occur in 16% (12-19%) of non-selected patients and in 18% (14-22%) of surgical patients, taking into account the heterogeneity between studies. The study methodology variables were not statistically significant in explaining variation in adverse outcome occurrence, but the individual studies, when used as a random effect variable, were significant. Conversely, the study variable was not significant to explain variation in mortality rates, whereas the study methodology variables were: having more than one reviewer increased mortality by 30-80%, older study populations resulted in higher mortality and including a cause in the definition halved the mortality rate. CONCLUSION: Study methodology variables do not explain differences in adverse outcome occurrence between studies. Other inter-study differences are more important. However, study methodology is an important predictor for mortality differences and should be taken into account when interpreting differences between studies.

Accessory thyroid gland at carotid bifurcation presenting as a carotid body tumor: case report and review of the literature.

Patients with carotid body tumors referred to vascular surgeons usually undergo magnetic resonance imaging (MRI) as part of the workup. We present a case report of a 39-year-old woman with a presumed carotid body tumor, as was expected from clinical and MRI findings. At surgery, the ectopic thyroid tissue was suspected, and resection was performed. Histologic examination showed normal thyroid tissue with no sign of malignancy. Postoperative thyroid analysis showed a normally located, properly functioning thyroid gland. Ectopic thyroid glands are generally found in the midline, as a result of abnormal median migration. Their presence lateral to the midline with a proper functioning thyroid gland in its normal position is extremely rare. Although several submandibular thyroid glands have been reported, a close relation with the carotid arteries was described only once. When MRI scans of a presumed carotid body tumor show tumor characteristics that are not fully specific for a carotid body tumor, the possibility of ectopic thyroid tissue should be entertained, which can be the patient's only properly functioning thyroid tissue. In such cases, additional assessment, including thyroid tests, should be considered before surgery.