Nevin Manimala

J Reconstr Microsurg. 2021 Dec 17. doi: 10.1055/s-0041-1740925. Online ahead of print.

ABSTRACT

BACKGROUND: Evidence in literature about the best reconstructive approach after melanoma resection is controversial, with some authors advocating that tissue rearrangement flap techniques might hinder the early detection of local relapses. The aim of the present study is to evaluate oncological, aesthetic, and functional outcomes following melanoma reconstruction using pedicled perforator-based flaps.

METHODS: The authors reviewed all patients affected by melanoma treated during a 6-year period. Demographic data, tumor characteristics, and operative variables were evaluated. Locoregional recurrence was assessed with clinical and radiological follow-up. One-year postoperatively patients rated on a 5-point Likert scale the aesthetic and functional outcomes of the procedure. Three blind observers examined preoperative and 1-year postoperative photographs and rated the aesthetic outcome of the reconstructive procedure.

RESULTS: One-hundred sixty-five patients were treated with wide excision and delayed reconstruction, including pedicled perforator-based flaps in 70 patients (group A) and primary closure in 95 patients (group B). Mean Breslow thickness was 2.972 and 2.189 mm in group A and B, respectively. There was no statistically significant difference in locoregional recurrence (chi-squared test, p = 0.8333; Fisher’s exact test, p > 0.9999) between the two groups. Group A reported a higher satisfaction with both the aesthetic (mean rating 4.390 in group A and 4.094 in group B) and functional (mean rating 4.732 in group A and 4.170 in group B) outcomes of the procedure, the latter being statistically significant (p = 0.0006).

CONCLUSION: This series suggests that pedicled perforator-based flaps provide optimal aesthetic and functional outcomes in melanoma reconstruction without impairing the locoregional control of the disease.

PMID:34921368 | DOI:10.1055/s-0041-1740925

Cardiovasc Intervent Radiol. 2021 Dec 17. doi: 10.1007/s00270-021-03024-8. Online ahead of print.

ABSTRACT

PURPOSE: In this in vitro study, the effectiveness and safety of four aspiration-based techniques for thrombectomy are evaluated for three types of thrombi in a flow model simulating the femoropopliteal segment.

MATERIAL AND METHODS: Red, white, and mixed thrombi were produced in a standardized manner and used to simulate occlusion of a superficial femoral artery using a pulsatile flow model. Four techniques were compared: aspiration alone, aspiration + stent retriever, exposing thrombus to laser by an excimer laser system and a laser catheter + aspiration, and aspiration + mechanical fragmentation by a separator. Rate of first-pass recanalization, embolic events, and number of embolized fragments > 1 mm were compared.

RESULTS: Aspiration alone, stent retriever, laser, and separator differed in rates of first-pass recanalization (53.3%; 86.6%; 20%; and 100%) and embolic events (40%; 93.3%; 73.3%; and 60%). Number of embolized fragments was lowest with aspiration and higher with separator, laser, and stent retriever. Rates of first-pass-recanalization (75%; 75%; and 45%) and embolic events (65%; 60%; and 75%) differed for red, white, and mixed thrombi. The mixed thrombus caused the highest number of embolized fragments, which was particularly high using the stent retriever.

CONCLUSION: Additional use of mechanical techniques significantly enhances the effectiveness of thrombectomy but simultaneously provokes more embolism. Laser seems to negatively alter the structure of a thrombus and thus diminishes the effectiveness, while provoking embolism. All techniques had lowest effectiveness, but highest embolism with the mixed thrombus. This was particularly striking when a stent retriever was used with the mixed thrombus.

PMID:34921347 | DOI:10.1007/s00270-021-03024-8

Atten Percept Psychophys. 2021 Dec 17. doi: 10.3758/s13414-021-02418-7. Online ahead of print.

ABSTRACT

Adults’ ability to attain and retain nonnative speech sound categories vary substantially among individuals. While we know that speech-perceptual skills play a role, we know less about how consolidation-related changes in acoustic-phonetic memory contribute to perceptual tasks. The goal of this investigation was to examine contributions of memory and perceptual skills to the perceptual performance on a trained nonnative speech contrast over two days. Twenty-one adult participants (ages 18-24) completed four different experiments. Three of these assessed learning and memory: visual statistical learning (implicit), visual object recognition (explicit), and nonnative (Hindi dental-retroflex) speech-sound training. Participants completed the learning tasks around 8 p.m., and performance was measured shortly after learning and again 12 hours later. On a separate day, participants completed a categorical perception task on a native (/a/-/e/) vowel continuum. Nonnative speech perception was associated with implicit learning performance when both were assessed shortly after learning, and associated with the retention of explicit memory when both were assessed after an overnight delay. Native speech-sounds were at least marginally associated with nonnative speech perception performance on both days, but with a stronger association observed with performance assessed on Day 2. These findings provide preliminary support for the interpretation that speech-sounds are encoded by at least two memory systems in parallel, but that perceptual performance may reflect acoustic-phonetic knowledge learned by different memory systems over time since exposure. Moreover, performance on speech perception tasks in both native and nonnative speech-sounds may rely on similar retrieval mechanisms for long-term storage of speech-sound information.

PMID:34921334 | DOI:10.3758/s13414-021-02418-7

Int Health. 2021 Dec 17:ihab084. doi: 10.1093/inthealth/ihab084. Online ahead of print.

ABSTRACT

BACKGROUND: Most infants in southeastern Ethiopia are either born at home or discharged from the health facility early and families should be able to recognize signs of newborn illnesses and bring the sick newborn to a health facility to receive care. However, studies are limited and the available studies were conducted in urban areas and/or at an institution level. This study aimed to assess the determinants of maternal knowledge of neonatal danger signs and care-seeking practices.

METHODS: A community-based cross-sectional study was conducted on 520 post-natal mothers using a multistage sampling method from 1 to 30 March 2019. The data were analysed using SPSS version 20 using binary logistic regression. Statistical significance was declared at p<0.05.

RESULTS: Mothers’ level of knowledge of neonatal danger signs was 50.2% (95% confidence interval [CI] 46.3 to 54.3) and 61% of them sought healthcare when they noticed danger signs. Maternal education level (adjusted odds ratio [AOR] 2.15 [95% CI 1.11 to 4.17]), husband’s education level (AOR 2.05 [95% CI 1.07 to 3.94]), residency (AOR 5.83 [95% CI 2.77 to 12.24]), antenatal visits (AOR 2.10 [95% CI 1.13 to 3.90]), antenatal care (ANC) counselling (AOR 4.33 [95% CI 1.88 to 9.98]) and knowledge about essential newborn care (AOR 3.91 [95% CI 2.05 to 7.48]) were the determining factors.

CONCLUSION: The mothers’ level of knowledge of neonatal danger signs was low and unsafe care-seeking practices were identified. The mothers’ education level, husbands’ education level, residence, ANC visits, counselling during ANC and knowledge about essential newborn care were found to be statistically significant determinants. Most of the mothers take their sick neonates to traditional healers and provide home remedies. Intervention modalities focusing on maternal counselling on the most common symptoms of illness in neonates are essential to increase mothers’ recognition of illness and improve care-seeking practices.

PMID:34921316 | DOI:10.1093/inthealth/ihab084

J Am Med Inform Assoc. 2021 Dec 17:ocab258. doi: 10.1093/jamia/ocab258. Online ahead of print.

ABSTRACT

OBJECTIVE: The purpose of this study was to measure the association between neighborhood deprivation and cesarean delivery following labor induction among people delivering at term (≥37 weeks of gestation).

MATERIALS AND METHODS: We conducted a retrospective cohort study of people ≥37 weeks of gestation, with a live, singleton gestation, who underwent labor induction from 2010 to 2017 at Penn Medicine. We excluded people with a prior cesarean delivery and those with missing geocoding information. Our primary exposure was a nationally validated Area Deprivation Index with scores ranging from 1 to 100 (least to most deprived). We used a generalized linear mixed model to calculate the odds of postinduction cesarean delivery among people in 4 equally-spaced levels of neighborhood deprivation. We also conducted a sensitivity analysis with residential mobility.

RESULTS: Our cohort contained 8672 people receiving an induction at Penn Medicine. After adjustment for confounders, we found that people living in the most deprived neighborhoods were at a 29% increased risk of post-induction cesarean delivery (adjusted odds ratio = 1.29, 95% confidence interval, 1.05-1.57) compared to the least deprived. In a sensitivity analysis, including residential mobility seemed to magnify the effect sizes of the association between neighborhood deprivation and postinduction cesarean delivery, but this information was only available for a subset of people.

CONCLUSIONS: People living in neighborhoods with higher deprivation had higher odds of postinduction cesarean delivery compared to people living in less deprived neighborhoods. This work represents an important first step in understanding the impact of disadvantaged neighborhoods on adverse delivery outcomes.

PMID:34921313 | DOI:10.1093/jamia/ocab258

Neuropsychopharmacology. 2021 Dec 17. doi: 10.1038/s41386-021-01250-9. Online ahead of print.

ABSTRACT

Exposure to early-life adversity (ELA) is associated with several neuropsychiatric conditions, including major depressive disorder, yet causality is difficult to establish in humans. Recent work in rodents has implicated impaired reward circuit signaling in anhedonic-like behavior after ELA exposure. Anhedonia, the lack of reactivity to previously rewarding stimuli, is a transdiagnostic construct common to mental illnesses associated with ELA. Here, we employed an assay of reward responsiveness validated across species, the Probabilistic Reward Task (PRT). In the PRT, healthy participants reliably develop a response bias toward the more richly rewarded stimulus, whereas participants with anhedonia exhibit a blunted response bias that correlates with current and future anhedonia. In a well-established model of ELA that generates a stressful, chaotic, and unpredictable early-life environment, ELA led to blunted response biases in the PRT in two separate cohorts, recapitulating findings in humans with anhedonia. The same ELA rats had blunted sucrose preference, further supporting their anhedonic-like phenotypes. Probing the aspects of ELA that might provoke these deficits, we quantified the unpredictability of dam/pup interactions using entropy measures and found that the unpredictability of maternal care was significantly higher in the ELA groups in which PRT and sucrose preference reward deficits were present later in life. Taken together, these data position the PRT, established in clinical patient populations, as a potent instrument to assess the impact of ELA on the reward circuit across species. These findings also implicate the unpredictability of maternal signals during early life as an important driver of reward sensitivity deficits.

PMID:34921225 | DOI:10.1038/s41386-021-01250-9

J Neurosurg. 2021 Dec 17:1-8. doi: 10.3171/2021.8.JNS211321. Online ahead of print.

ABSTRACT

OBJECTIVE: Retrospective patient cohort studies have identified risk factors associated with recurrent focal neurological events in patients with symptomatic cerebral cavernous malformations (CCMs). Using a prospectively maintained database of patients with CCMs, this study identified key risk factors for recurrent neurological events in patients with symptomatic CCM. A simple scoring system and risk stratification calculator was then created to predict future neurological events in patients with symptomatic CCMs.

METHODS: This was a dual-center, prospectively acquired, retrospectively analyzed cohort study. Adult patients who presented with symptomatic CCMs causing focal neurological deficits or seizures were uniformly treated and clinically followed from the time of diagnosis onward. Baseline variables included age, sex, history of intracerebral hemorrhage, lesion multiplicity, location, eloquence, size, number of past neurological events, and duration since last event. Stepwise multivariable Cox regression was used to derive independent predictors of recurrent neurological events, and predictive accuracy was assessed. A scoring system based on the relative magnitude of each risk factor was devised, and Kaplan-Meier curve analysis was used to compare event-free survival among patients with different score values. Subsequently, 1-, 2-, and 5-year neurological event rates were calculated for every score value on the basis of the final model.

RESULTS: In total, 126 (47%) of 270 patients met the inclusion criteria. During the mean (interquartile range) follow-up of 54.4 (12-66) months, 55 patients (44%) experienced recurrent neurological events. Multivariable analysis yielded 4 risk factors: bleeding at presentation (HR 1.92, p = 0.048), large size ≥ 12 mm (HR 2.06, p = 0.016), eloquent location (HR 3.01, p = 0.013), and duration ≤ 1 year since last event (HR 9.28, p = 0.002). The model achieved an optimism-corrected c-statistic of 0.7209. All factors were assigned 1 point, except duration from last event which was assigned 2 points. The acronym BLED2 summarizes the scoring system. The 1-, 2-, and 5-year risks of a recurrent neurological event ranged from 0.6%, 1.2%, and 2.3%, respectively, for patients with a BLED2 score of 0, to 48%, 74%, and 93%, respectively, for patients with a BLED2 score of 5.

CONCLUSIONS: The BLED2 risk score predicts prospective neurological events in symptomatic CCM patients.

PMID:34920431 | DOI:10.3171/2021.8.JNS211321

J Neurosurg Pediatr. 2021 Dec 17:1-8. doi: 10.3171/2021.9.PEDS21242. Online ahead of print.

ABSTRACT

OBJECTIVE: Ventriculoperitoneal shunts (VPSs) for hydrocephalus in patients with achondroplasia are known to have a higher failure rate than in other hydrocephalus populations. However, the etiology of hydrocephalus in this group is considered “communicating,” and, therefore, potentially not amenable to endoscopic third ventriculostomy (ETV). ETV has, nonetheless, been reported to be successful in a small number of patients with achondroplasia. The authors aimed to investigate the long-term results of ETV in this population.

METHODS: Patients with achondroplasia who had undergone surgical treatment for hydrocephalus (ETV or VPS placement) were identified. In patients who had undergone ETV, medical records and neuroimages were reviewed to determine ventricular volumes and frontal and occipital horn ratios (FOHRs) pre- and postoperatively, as well as the incidence of surgical complications and reoperation. Patients who underwent VPS placement were included for historical comparison, and their medical records were reviewed for basic demographic information as well as the incidence of surgical complications and reoperation.

RESULTS: Of 114 pediatric patients with achondroplasia referred for neurosurgical consultation, 19 (17%) were treated for hydrocephalus; 10 patients underwent ETV only, 7 patients underwent VPS placement only, and 2 patients had a VPS placed followed by ETV. In patients treated with ETV, ventricular volume and FOHRs were normal, if measured at birth, and increased significantly until the time of the ETV. After ETV, all patients demonstrated significant and sustained decreases in ventricular measurements with surveillance up to 15 years. There was a statistically significant difference in rates of repeat CSF surgery between the ETV and VPS cohorts (0/12 vs 7/9, p < 0.001).

CONCLUSIONS: ETV was efficacious, safe, and durable in the treatment of hydrocephalus in patients with achondroplasia. Although many studies have indicated that hydrocephalus in these patients is “communicating,” a subset may develop an “obstructive” component that is progressive and responsive to ETV.

PMID:34920430 | DOI:10.3171/2021.9.PEDS21242

J Neurosurg. 2021 Dec 17:1-7. doi: 10.3171/2021.9.JNS21510. Online ahead of print.

ABSTRACT

OBJECTIVE: The objective of this study is to quantify the navigational accuracy of an advanced augmented reality (AR)-based guidance system for neurological surgery, biopsy, and/or other minimally invasive neurological surgical procedures.

METHODS: Five burr holes were drilled through a plastic cranium, and 5 optical fiducials (AprilTags) printed with CT-visible ink were placed on the frontal, temporal, and parietal bones of a human skull model. Three 0.5-mm-diameter targets were mounted in the interior of the skull on nylon posts near the level of the tentorium cerebelli and the pituitary fossa. The skull was filled with ballistic gelatin to simulate brain tissue. A CT scan was taken and virtual needle tracts were annotated on the preoperative 3D workstation for the combination of 3 targets and 5 access holes (15 target tracts). The resulting annotated study was uploaded to and launched by VisAR software operating on the HoloLens 2 holographic visor by viewing an encrypted, printed QR code assigned to the study by the preoperative workstation. The DICOM images were converted to 3D holograms and registered to the skull by alignment of the holographic fiducials with the AprilTags attached to the skull. Five volunteers, familiar with the VisAR, used the software/visor combination to navigate an 18-gauge needle/trocar through the series of burr holes to the target, resulting in 70 data points (15 for 4 users and 10 for 1 user). After each attempt the needle was left in the skull, supported by the ballistic gelatin, and a high-resolution CT was taken. Radial error and angle of error were determined using vector coordinates. Summary statistics were calculated individually and collectively.

RESULTS: The combined angle of error of was 2.30° ± 1.28°. The mean radial error for users was 3.62 ± 1.71 mm. The mean target depth was 85.41 mm.

CONCLUSIONS: The mean radial error and angle of error with the associated variance measures demonstrates that VisAR navigation may have utility for guiding a small needle to neural lesions, or targets within an accuracy of 3.62 mm. These values are sufficiently accurate for the navigation of many neurological procedures such as ventriculostomy.

PMID:34920422 | DOI:10.3171/2021.9.JNS21510

Phys Med. 2021 Dec 14;93:38-45. doi: 10.1016/j.ejmp.2021.12.005. Online ahead of print.

ABSTRACT

PURPOSE: This study aimed to determine the optimal initial electron beam parameters of a Linac for radiotherapy with a multivariate approach using statistical and machine-learning tools.

METHODS: For MC beam commissioning, a 6 MV Varian Clinac was simulated using the Geant4 toolkit. The authors investigated the relations between simulated dose distribution and initial electron beam parameters, namely, mean energy (E), energy spread (ES), and radial beam size (RS). The goodness of simulation was evaluated by the slope of differences between the simulated and the golden beam data. The best-fit combination of the electron beam parameters that minimized the slope of dose difference was searched through multivariate methods using conventional statistical methods and machine-learning tools of the scikit-learn library.

RESULTS: Simulation results with 87 combinations of the electron beam parameters were analyzed. Regardless of being univariate or multivariate, traditional statistical models did not recommend a single parameter set simultaneously minimizing slope of dose differences for percent depth dose (PDD) and lateral dose profile (LDP). Two machine learning classification modules, RandomForestClassifier and BaggingClassifier, agreed in recommending (E = 6.3 MeV, ES = ±5.0%, RS = 1.0 mm) for predicting simultaneous acceptance of PDD and LDP.

CONCLUSIONS: The machine learning with random-forest and bagging classifier modules recommended a consistent result. It was possible to draw an optimal electron beam parameter set using multivariate methods for MC simulation of a radiotherapy 6 MV Linac.

PMID:34920381 | DOI:10.1016/j.ejmp.2021.12.005