The physiology of intraoperative error: using electrokardiograms to understand operator performance during robot-assisted surgery simulations.

BACKGROUND: No platform for objective, synchronous and on-line evaluation of both intraoperative error and surgeon physiology yet exists. Electrokardiogram (EKG) metrics have been associated with cognitive and affective features that are known to impact surgical performance but have not yet been analyzed in conjunction with real-time error signals using objective, real-time methods. METHODS: EKGs and operating console point-of-views (POVs) for fifteen general surgery residents and five non-medically trained participants were captured during three simulated robotic-assisted surgery (RAS) procedures. Time and frequency-domain EKG statistics were extracted from recorded EKGs. Intraoperative errors were detected from operating console POV videos. EKG statistics were synchronized with intraoperative error signals. RESULTS: Relative to personalized baselines, IBI, SDNN and RMSSD decreased 0.15% (S.E. 3.603e-04; P = 3.25e-05), 3.08% (S.E. 1.603e-03; P < 2e-16) and 1.19% (S.E. 2.631e-03; P = 5.66e-06), respectively, during error. Relative LF RMS power decreased 1.44% (S.E. 2.337e-03; P = 8.38e-10), and relative HF RMS power increased 5.51% (S.E. 1.945e-03; P < 2e-16). CONCLUSIONS: Use of a novel, on-line biometric and operating room data capture and analysis platform enabled detection of distinct operator physiological changes during intraoperative errors. Monitoring operator EKG metrics during surgery may help improve patient outcomes through real-time assessments of intraoperative surgical proficiency and perceived difficulty as well as inform personalized surgical skills development.

The neurophysiology of intraoperative error: An EEG study of trainee surgeons during robotic-assisted surgery simulations.

Surgeons operate in mentally and physically demanding workspaces where the impact of error is highly consequential. Accurately characterizing the neurophysiology of surgeons during intraoperative error will help guide more accurate performance assessment and precision training for surgeons and other teleoperators. To better understand the neurophysiology of intraoperative error, we build and deploy a system for intraoperative error detection and electroencephalography (EEG) signal synchronization during robot-assisted surgery (RAS). We then examine the association between EEG data and detected errors. Our results suggest that there are significant EEG changes during intraoperative error that are detectable irrespective of surgical experience level.

Computing SARS-CoV-2 Infection Risk From Symptoms, Imaging, and Test Data: Diagnostic Model Development.

BACKGROUND: Assigning meaningful probabilities of SARS-CoV-2 infection risk presents a diagnostic challenge across the continuum of care. OBJECTIVE: The aim of this study was to develop and clinically validate an adaptable, personalized diagnostic model to assist clinicians in ruling in and ruling out COVID-19 in potential patients. We compared the diagnostic performance of probabilistic, graphical, and machine learning models against a previously published benchmark model. METHODS: We integrated patient symptoms and test data using machine learning and Bayesian inference to quantify individual patient risk of SARS-CoV-2 infection. We trained models with 100,000 simulated patient profiles based on 13 symptoms and estimated local prevalence, imaging, and molecular diagnostic performance from published reports. We tested these models with consecutive patients who presented with a COVID-19-compatible illness at the University of California San Diego Medical Center over the course of 14 days starting in March 2020. RESULTS: We included 55 consecutive patients with fever (n=43, 78%) or cough (n=42, 77%) presenting for ambulatory (n=11, 20%) or hospital care (n=44, 80%). In total, 51% (n=28) were female and 49% (n=27) were aged <60 years. Common comorbidities included diabetes (n=12, 22%), hypertension (n=15, 27%), cancer (n=9, 16%), and cardiovascular disease (n=7, 13%). Of these, 69% (n=38) were confirmed via reverse transcription-polymerase chain reaction (RT-PCR) to be positive for SARS-CoV-2 infection, and 20% (n=11) had repeated negative nucleic acid testing and an alternate diagnosis. Bayesian inference network, distance metric learning, and ensemble models discriminated between patients with SARS-CoV-2 infection and alternate diagnoses with sensitivities of 81.6%-84.2%, specificities of 58.8%-70.6%, and accuracies of 61.4%-71.8%. After integrating imaging and laboratory test statistics with the predictions of the Bayesian inference network, changes in diagnostic uncertainty at each step in the simulated clinical evaluation process were highly sensitive to location, symptom, and diagnostic test choices. CONCLUSIONS: Decision support models that incorporate symptoms and available test results can help providers diagnose SARS-CoV-2 infection in real-world settings.

Application of Indocyanine Green in Flap Surgery: A Systematic Review.

BACKGROUND: The vascularization of the distal portions of transferred tissue represents the most critical factor in the success of reconstructive surgery. In recent years, indocyanine green (ICG) fluorescence imaging techniques have been applied during surgery to evaluate flap perfusion. However, this investigation has found that there is little consensus regarding the standard dose of ICG as well as the pre-operative requirements of ICG allergy testing. The aim of this study is to summarize the applications of ICG to tissue transfers and safe dosing practices and to provide insight to the possible adverse effects of ICG on flap surgery with the goal of helping clinicians apply ICG safely and efficiently to tissue transfer procedures. METHODS: A literature search was performed using, Wiley InterScience, and Springer with the key words, 'Flap,' 'indocyanine green,' 'surgery,' and related mesh words for all publications between 2005 and 2015. Title and abstract screening was performed using predefined in- and exclusion criteria. RESULTS: Seventy-three articles were included. These were classified as "application of ICG in flap surgery" and "the security of applying ICG in flap surgery". CONCLUSIONS: ICG fluorescence imaging preoperatively facilitates the detection of perforators in tissue flaps with thickness <20 mm, aids in the evaluation of flap microcirculation and perfusion, and allows surgeons to select dominant cutaneous nerves while evaluating the quality of vascular anastomoses and locating thromboses. The literature also concluded that potential allergic reactions to ICG should be taken into consideration.

Microsurgical dissection of facial nerve in parotidectomy: a discussion of techniques and long-term results.

BACKGROUND: Parotidectomy has well-documented post-operative complications. Dissection of the facial nerve branches can be challenging even under loupe magnification, and partial, or complete injury of the nerve branches can occur during surgery. To reduce this risk and the associated complications, we propose a number of microsurgical best practices, which can be performed during parotidectomy. METHODS: A retrospective survey was conducted on 109 patients (45 males and 64 females, average age 46.2 years, range of 6 to 74 years) who underwent parotidectomy in two different institutions. RESULTS: Our data showed no permanent injury to the facial nerve, and 17% of neuroapraxia that had resolved with time. Post-operative complications have occurred in 33 cases (30% rate). In the superficial parotidectomy cohort (78 patients), the number of complications was 17 (21%). In the total parotidectomy cohort (31 patients), the number of complications was 16 (51%). CONCLUSIONS: Based on our results, we believe that the use of microsurgical techniques during parotidectomy may represent a useful tool in improving accuracy and minimising local tissue trauma that can affect nerve recovery. This is particularly true in situations such as tumor recurrence, tissue fibrosis or in case of sizeable tumors around the facial nerve branches. We believe that the decreased risk of facial nerve post-operative symptoms outweigh the disadvantage of increased operative time of this procedure.

Far infrared ray (FIR) therapy: An effective and oncological safe treatment modality for breast cancer related lymphedema.

BACKGROUND: The incidence of breast cancer related lymphedema is approximately 5%. Far infrared ray (FIR) treatment can potentially reduce fluid volume and extremity circumference as well as the frequency of dermato-lymphangitis (DLA). However, there is no published data on the oncological safety of FIR and the potential for activation of any residual breast cancer cells. The aim of this study is to investigate the safety of far infrared ray (FIR) treatment of postmastectomy lymphedema, clinically and in vitro. METHODS: Patients who underwent mastectomy more than 5years ago complicated by upper extremity lymphedema for more than 1year were included. The enrolled patients were divided into an FIR treatment group and a control group (conservative treatment using bandage compression). Outcome measures included tumor markers (CA153, CA125), ultrasonography of relevant structures and monitoring for adverse reactions 1year after treatment. For the in vitro part of the study, the effects of FIR on human breast adenocarcinoma cell lines (MCF7, MDA-MB231) compared to the effects of FIR on human dermal fibroblasts as a control were considered. The viability, proliferation, cell cycle and apoptotic statistics of the adenocarcinoma and human dermal fibroblast cell lines were analyzed and compared. RESULTS: Results demonstrated that after treatment with FIR, tumor marker (CA153, CA125) concentrations in both the FIR and control groups were not elevated. There was no statistically significant difference between FIR and control group marker expression (p>0.05). Furthermore, no patients were diagnosed with lymphadenectasis or newly enlarged lymph nodes in these two groups. Importantly, there were no adverse events in either group. The in vitro experiment indicated that FIR radiation does not affect viability, proliferation, cell cycle and apoptosis of fibroblasts, MCF-7 and MDA-MB-231 cells. CONCLUSIONS: FIR should be considered as feasible and safe for the treatment of breast cancer related lymphedema patients 5years after mastectomy. FIR does not promote recurrence or metastasis of breast cancer and is a well-tolerated therapy with no adverse reactions.

Malnutrition Increases With Obesity and Is a Stronger Independent Risk Factor for Postoperative Complications: A Propensity-Adjusted Analysis of Total Hip Arthroplasty Patients.

BACKGROUND: Obesity is frequently associated with complications after total hip arthroplasty (THA) and is often concomitant with malnutrition. The purpose of this study was to investigate the independent morbidity risk of malnutrition relative to obesity. METHODS: The National Surgical Quality Improvement Program from 2005 to 2013 was queried for elective primary THA cases. Malnutrition was defined as albumin <3.5 g/dL. Propensity scores for having preoperative albumin data were determined from demographics, body mass index, and overall comorbidity burden. Patients were classified as nonobese (body mass index 18.5-29.9), obese I (30-34.9), obese II (35-39.9), or obese III (≥40). Complications were compared across nutritional and obesity classes. Multivariable propensity-adjusted logistic regressions were used to examine associations between obesity and malnutrition with 30-day outcomes. RESULTS: A total of 40,653 THA cases were identified, of which 20,210 (49.7%) had preoperative albumin measurements. Propensity score adjustment successfully reduced potential selection bias, with P > .05 for differences between those with and without albumin data. Malnutrition incidence increased from 2.8% in obese I to 5.7% in obese III patients. With multivariable propensity-adjusted logistic regression, malnutrition was a more robust predictor than any obesity class for any postoperative complication(s) (odds ratio [OR] 1.61, 95% confidence interval [CI] 1.25-2.08), major complications (OR 1.63, 95% CI 1.21-2.19), respiratory complications (OR 2.35, 95% CI 1.27-4.37), blood transfusions (OR 1.71, 95% CI 1.44-2.03), and extended length of stay (OR 1.35, 95% CI 1.14-1.59). CONCLUSION: Malnutrition incidence increased significantly from obese I to obese III patients and was a stronger and more consistent predictor than obesity of complications after THA.

Potential Use of Transferred Lymph Nodes as Metastasis Detectors after Tumor Excision.

Due to the fact that it reliably results in positive outcomes, lymph node flap transfer is becoming an increasingly popular surgical procedure for the prevention and treatment of lymphedema. This technique has been shown to stimulate lymphoangiogenesis and restore lymphatic function, as well as decreasing infection rates, minimizing pain, and preventing the recurrence of lymphedema. In this article, we investigate possible additional benefits of lymph node flap transfer, primarily the possibility that sentinel lymph nodes may be used to detect micro-metastasis or in-transit metastasis and may function as an additional lymphatic station after the excision of advanced skin cancer.