Advancing indocyanine green fluorescence flap perfusion assessment via near infrared signal quantification.

Introduction: Intraoperative indocyanine green fluorescence angiography (ICGFA) perfusion assessment has been demonstrated to reduce complications in reconstructive surgery. This study sought to advance ICGFA flap perfusion assessment via quantification methodologies. Method: Patients undergoing pedicled and free flap reconstruction were subjected to intraoperative ICGFA flap perfusion assessment using either an open or endoscopic system. Patient demographics, clinical impact of ICGFA and outcomes were documented. From the ICGFA recordings, fluorescence signal quality, as well as inflow/outflow milestones for the flap and surrounding (control) tissue were computationally quantified post hoc and compared on a region of interest (ROI) level. Further software development intended full flap quantification, metric computation and heatmap generation. Results: Fifteen patients underwent ICGFA assessment at reconstruction (8 head and neck, 6 breast and 1 perineum) including 10 free and 5 pedicled flaps. Visual ICGFA interpretation altered on-table management in 33.3% of cases, with flap edges trimmed in 4 and a re-anastomosis in 1 patient. One patient suffered post-operative flap dehiscence. Laparoscopic camera use proved feasible but recorded a lower quality signal than the open system.Using established and novel metrics, objective ICGFA signal ROI quantification permitted perfusion comparisons between the flap and surrounding tissue. Full flap assessment feasibility was demonstrated by computing all pixels and subsequent outputs summarisation as heatmaps. Conclusion: This trial demonstrated the feasibility and potential for ICGFA with operator based and quantitative flap perfusion assessment across several reconstructive applications. Further development and implementation of these computational methods requires technique and device standardisation.

Anestesia libre de opioides en hemicolectomía abierta derecha extendida. Reporte de un caso y revisión / Opiod Free Anesthesia (OFA) for Open extended right colectomy. A case report and review

Opioid free anesthesia (OFA) is defined as an anesthesiologic technique where opioids are not used in the intraoperative and postoperative period. Although the mainstay of intra-operative analgesia may be opioids, current challenges are focus on reducing them and preventing the adverse effects of opioids, by rationalizing and even suspending their perioperative use, specifically at risk populations such as Obstructive Sleep Apnea Syndrome (OSAHS), obesity, Chronic Obstructive Pulmonary Disease (COPD) and cancer surgery. We present this case of OFA in a susceptible patient with complications from the use of opioids undergoing an extended right hemicolectomy. Multimodal analgesia was performed with a thoracic peridural and subanesthetic doses of intravenous agents including dexmedetomidine, ketamine and propofol, accompanied by short and long-lasting local periglotic anesthetics. The patient had given an intraand postoperative analgesia without presenting any adverse events, good recovery, early deambulation and extubation.

La anestesia libre de opioides (OFA) es una técnica anestésica donde no hay administración de opioides, tanto en el intraoperatorio como en el postoperatorio. Aunque una de las bases de la analgesia intraoperatoria podrían ser los opioides, los desafíos actuales están enfocados en reducir su uso perioperatorio, previniendo sus efectos adversos, racionalizando y limitando su empleo específicamente en poblaciones de riesgo como síndrome de apnea obstructiva del sueño (SAHOS), obesidad, enfermedad pulmonar obstructiva crónica (EPOC) y cirugía oncológica. Presentamos este caso de OFA en un paciente susceptible de complicaciones por uso de opioides sometido a una hemicolectomía derecha extendida. Se realizó analgesia multimodal con peridural torácica y dosis subanestésicas de agentes endovenosos como dexmedetomidina, ketamina y propofol, acompañado de anestésicos locales periglóticos de corta y larga duración. Se otorgó una adecuada analgesia intra y postoperatoria, el paciente no tuvo eventos adversos, presentando una buena recuperación, deambulación y extubación precoz.

Set-up error validation with EPID images: Measurements vs Egs_cbct simulation.

AIM: In this study, the egs_cbct code's ability to replicate an electronic portal imaging device (EPID) is explored. BACKGROUND: We have investigated head and neck (H&N) setup verification on an Elekta Precise linear accelerator. It is equipped with an electronic portal imaging device (EPID) that can capture a set of projection images over different gantry angles. METHODS AND MATERIALS: Cone-beam computed tomography (CBCT) images were reconstructed from projection images of two different setup scenarios. Projections of an Anthropomorphic Rando head phantom were also simulated by using the egs_cbct Monte Carlo code for comparison with the measured projections.Afterwards, CBCT images were reconstructed from this data. Image quality was evaluated against a metric defined as the image acquisition interval (IAI). It determines the number of projection images to be used for CBCT image reconstruction. RESULTS: From this results it was established that phantom shifts could be determined within 2 mm and rotations within one degree accuracy using only 20 projection images (IAI = 10 degrees). Similar results were obtained with the simulated data. CONCLUSION: In this study it is demonstrated that a head and neck setup can be verified using substantially fewer projection images. Bony landmarks and air cavities could still be observed in the reconstructed Rando head phantom. The egs_cbct code can be used as a tool to investigate setup errors without tedious measurements with an EPID system.

C-reactive protein as a predictor of anastomotic leak in the first week after anterior resection for rectal cancer.

AIM: Anastomotic leak (AL) after anterior resection results in increased morbidity, mortality and local recurrence. The aim of this study was to assess the ability of C-reactive protein (CRP) to predict AL in the first week after anterior resection for rectal cancer. METHOD: A retrospective review of a prospectively maintained database that included all patients undergoing anterior resection between January 2008 and December 2013 was performed. The ability of CRP to predict AL was assessed using area under the receiver-operating characteristics (AUC) curves. The severity of AL was defined using the International Study Group of Rectal Cancer (ISREC) grading system. RESULTS: Two-hundred and eleven patients were included in the study. Statistically significant differences in mean CRP values were found between those with and without an AL on postoperative days 5, 6 and 7. A CRP value of 132 mg/l on postoperative day 5 had an AUC of 0.75, corresponding to a sensitivity of 70%, a specificity of 76.6%, a positive predictive value of 16.3% and a negative predictive value of 97.5%. Multivariable analysis found that a CRP of > 132 mg/l on postoperative day 5 was the only statistically significant patient factor that was linked to an increased risk of AL (HR = 8.023, 95% CI: 1.936-33.238, P = 0.004). CONCLUSION: Early detection of AL may minimize postoperative complications. CRP is a useful negative predictive test for the development of AL following anterior resection.

Monte carlo electron source model validation for an Elekta Precise linac.

PURPOSE: Electron radiation therapy is used frequently for the treatment of skin cancers and superficial tumors especially in the absence of kilovoltage treatment units. Head-and-neck treatment sites require accurate dose distribution calculation to minimize dose to critical structures, e.g., the eye, optic chiasm, nerves, and parotid gland. Monte Carlo simulations can be regarded as the dose calculation method of choice because it can simulate electron transport through any tissue and geometry. In order to use this technique, an accurate electron beam model should be used. METHODS: In this study, a two point-source electron beam model developed for an Elekta Precise linear accelerator was validated. Monte Carlo data were benchmarked against measured water tank data for a set of regular and circular fields and at 95, 100, and 110 cm source-to-skin-distance. EDR2 Film dose distribution data were also obtained for a paranasal sinus treatment case using a Rando phantom and compared with corresponding dose distribution data obtained from Monte Carlo simulations and a CMS XiO treatment planning system. A partially shielded electron field was also evaluated using a solid water phantom and EDR2 film measurements against Monte Carlo simulations using the developed source model. RESULTS: The major findings were that it could accurately replicate percentage depth dose and beam profile data for water measurements at source-to-skin-distances ranging between 95 and 110 cm over beam energies ranging from 4 to 15 MeV. This represents a stand-off between 0 and 15 cm. Most percentage depth dose and beam profile data (better than 95%) agreed within 2%/2 mm and nearly 100% of the data compared within 3%/3 mm. Calculated penumbra data were within 2 mm for the 20 x 20 cm2 field compared to water tank data at 95 cm source-to-skin-distance over the above energy range. Film data for the Rando phantom case showed gamma index map data that is similar in comparison with the treatment planning system and the Monte Carlo source model. The gamma index showed good agreement (2%/2 mm) between the Monte Carlo source model and the film data. CONCLUSIONS: Percentage depth dose and beam profile data were in most cases within a tolerance of 2%/2 mm. The biggest discrepancies were in most cases recorded in the first 6 mm of the water phantom. Circular fields showed local dose agreement within 3%/3mm. Good agreement was found between calculated dose distributions for a paranasal sinus case between Monte Carlo, film measurements and a CMS XiO treatment planning system. The electron beam model can be easily implemented in the BEAMnrc or DOSXYZnrc Monte Carlo codes enabling quick calculation of electron dose distributions in complex geometries.

Meningitis neonatal por Streptococcus pneumoniae atípico: Reporte de un caso y revisión / Neonatal meningitis caused by atypical Streptococcus pneumoniae: Case report and review

Streptococcus pneumoniae is a rarely recognized cause of neonatal sepsis and/or meningitis, but it is associated with substantial morbidity and mortality. Traditionally, S. pneumoniae is identified in the laboratory by demonstrating susceptibility to optochin. However, the emergence of optochin-resistant organisms makes definite identification difficult when only phenotypic tests are taken as markers. We present the case of a severe early-onset neonatal meningitis due to an atypical strain of S. pneumoniae. Laboratory methods utilized to certify this species diagnosis are discussed.

Streptococcus pneumoniae es una causa infrecuente de infección en el recién nacido y se caracteriza por gran capacidad invasora (sepsis, meningitis) y alta mortalidad. Tradicionalmente, esta bacteria se diagnostica en base a su susceptibilidad a optoquina. Sin embargo, la emergencia de cepas de S. pneumoniae resistentes a optoquina (atípicas) dificulta el diagnóstico sin utilizar varias pruebas diagnósticas, incluyendo las de biología molecular. Se describe el caso de una neonata con infección invasora causada por una cepa de S. pneumoniae atípico y se discuten los métodos empleados para certificar el diagnóstico de esta especie.

Microphthalmia transcription factor immunohistochemistry: a useful diagnostic marker in the diagnosis and detection of cutaneous melanoma, sentinel lymph node metastases, and extracutaneous melanocytic neoplasms.

BACKGROUND: Melanoma is the most lethal form of skin cancer. Diagnosis of amelanotic melanoma and detection of micrometastases in sentinel lymph nodes pose diagnostic and therapeutic dilemmas for the dermatopathologist and clinician. OBJECTIVE: The purpose of this article is to determine the utility of immunohistochemistry using antibodies specific for microphthalmia in the identification of melanocytic lesions in the skin, eye, central nervous system, and sentinel lymph nodes. METHODS: Paraffin-embedded, formalin-fixed specimens of cutaneous melanoma, including amelanotic melanoma and lentigo maligna melanoma, were stained with antibodies specific for microphthalmia. In addition, paraffin sections of extracutaneous lesions, including sentinel lymph nodes, uveal melanoma, and central nervous system melanocytomas, were stained with the specific microphthalmia antibody. RESULTS: All cutaneous melanomas stained positively with microphthalmia, as did uveal melanomas and central nervous system melanocytomas. These findings confirm the melanocytic origin of melanocytomas and uveal melanomas and demonstrate that microphthalmia staining can be used to establish melanocytic origin of neoplasms. In addition, micrometastases were easily detected in sentinel lymph nodes. CONCLUSION: Microphthalmia transcription factor immunohistochemistry is a valuable tool in the identification of melanocytic lesions in numerous sites. Use of this stain may facilitate detection of micrometastases in sentinel lymph nodes.

Screening of patients with iron overload to identify hemochromatosis and porphyria cutanea tarda.

OBJECTIVE: To assess the importance of iron overload as a risk factor for porphyria cutanea tarda (PCT). DESIGN: Prospective study during a 4-month period. SETTING: Departments of emergency care, gastroenterology, and dermatology in a tertiary referral center. PATIENTS: Patients were deemed eligible for inclusion in the study if serum ferritin levels were greater than 500 micrograms/L (normal range: females, < 125 micrograms/L; males, < 325 micrograms/L). MAIN OUTCOME MEASURES: Porphyrin excretion profiles were analyzed on all patients included in the study, where clinically relevant. A diagnosis of PCT was confirmed biochemically in all cases. The HLA typing was then performed on newly diagnosed cases of PCT. RESULTS: Of 4127 patients tested, 240 patients with an elevated serum ferritin level were identified, of whom 74 had an elevated serum ferritin level of more than 500 micrograms/L. Of the latter group, 17.5% had hemochromatosis and 6.7% had PCT. The incidence of PCT in the hemochromatosis group was 23%; HLA typing revealed the presence of at least 1 of the hemochromatosis markers. CONCLUSIONS: A high serum ferritin level in the absence of evident cause should prompt investigation for both hemochromatosis and PCT. The HLA heterozygosity for hemochromatosis in some patients with PCT may be a cause of hepatic siderosis.

Innervation and vascular pharmacodynamics of the mouse spleen.

Neurohistochemical and in vivo and electron microscopic methods demonstrated alpha-and beta-adrenergic receptors and adrenergic innervation in arterioles and "arterial" capillaries of the mouse spleen. Such innervation and receptors in venules and channels within the red pulp were sparse. Cholinergic innervation and receptors were judged to be absent in the microvasculature. Histamine elicited arteriolar dilation which was blocked by metiamide suggesting the presence of H2 receptors. However, following blockade of H2 receptors, histamine produced arteriolar constriction. Serotonin elicited only venular constriction. Lactic acid caused arteriolar constriction; bradykinin and prostaglandins (PG) E2 and PGF2 alpha triggered arteriolar constriction, but only at higher concentrations. The vasoconstriction evoked by cholinergic agonists, histamine, lactic acid, or PGs was partially or completely antagonized by alpha-adrenoceptor blockade or by reserpine, and the vasoconstrictor responses to histamine, lactic acid, PGs, bradykinin were enhanced in the presence of functional adrenergic nerves. In the latter case higher doses of phentolamine provoked arteriolar vasospasm. Although adenine nucleotides, guanosine, inosine, sodium phosphate, and sodium chloride elicited no response, adenosine was a potent vasodilator. This dilation was not blocked by beta-adrenergic antagonists, and it was enhanced in the presence of functional adrenergic nerves. The data suggest that: (1) cholinergic agonists, lactic acid, histamine, and PGE2 and PGF2 alpha cause alpha-mediated arteriolar constriction by releasing stored neurotransmitter(s) from splenic nerves, and (2) subthreshold quantities of neurotransmitter(s) may modulate microvascular sensitivity to vasoactive agents which act directly upon the vascular wall.