Citations

Clinical treatments of skeletal muscle weakness are hindered by a lack of an approach to evaluate individual muscle force. Intramuscular pressure (IMP) has shown a correlation to muscle force in vivo, but patient to patient and muscle to muscle variability results in difficulty of utilizing IMP to estimate muscle force. The goal of this work was to develop a finite element model of whole skeletal muscle that can predict IMP under passive and active conditions to further investigate the mechanisms of IMP variability. A previously validated hypervisco-poroelastic constitutive approach was modified to incorporate muscle activation through an inhomogeneous geometry. Model parameters were optimized to fit model stress to experimental data, and the resulting model fluid pressurization data were utilized for validation. Model fitting was excellent (root-mean-square error or RMSE <1.5 kPa for passive and active conditions), and IMP predictive capability was strong for both passive (RMSE 3.5 mmHg) and active (RMSE 10 mmHg at in vivo lengths) conditions. Additionally, model fluid pressure was affected by length under isometric conditions, as increases in stretch yielded decreases in fluid pressurization following a contraction, resulting from counteracting Poisson effects. Model pressure also varied spatially, with the highest gradients located near aponeuroses. These findings may explain variability of in vivo IMP measurements in the clinic, and thus help reduce this variability in future studies. Further development of this model to include isotonic contractions and muscle weakness would greatly benefit this work.

Purpose The purpose of this study is to identify radiographic risk factors (RRFs) and radiographic signs of abductor tendon tears. Methods Between April 2008 and October 2015, patients with intraoperative diagnosis of partial‐ or full‐thickness abductor tear noted at the time of open or endoscopic treatment were included in this study. Exclusion criteria included lack of preoperative standard supine pelvic radiograph, lack of preoperative magnetic resonance imaging (MRI), or abductor tear not present at the time of operative intervention. Patients were matched by age ±5 years, gender, and body mass index ±5 with patients with no abductor pathology by clinical exam and MRI. A standardized supine anterior‐posterior pelvis radiograph was performed on all patients. The radiographs were evaluated for RRF (pelvic width, body weight moment arm, abductor moment arm, abductor angle, pelvic height) and signs of abductor tendon pathology (greater trochanteric enthesophyte). Femoral version was measured on MRI when images were available. Statistical analysis was performed and included bivariate and multivariate analyses. Results There were 152 patients with abductor tears identified at the time of surgery out of 2,838 eligible patients matched with 125 patients without abductor tendon pathology. The study institution was unable to perform a 1:1 match because of the advanced age of the abductor tendon group, which led to a greater age in the abductor group ( n = 58) versus the control group ( n = 54; P = .01. In abductor group the average age was 58, and 137 of 152 (90%) patients were female; in the control group the average age was 54, with 111 of 125 (89%) patients being female. Abductor tear patients were treated with surgical repair. The RRFs found with bivariate analysis were an increased pelvic width (14.8 cm for abductor tears vs 14.3 cm for control; P < .001), body weight moment arm (11.1 cm vs 10.9 cm; P < .001), and abductor moment arm (7.8 cm vs 7.6 cm; P < .001); decreased femoral anteversion (7.6° vs 10.6°; P = .045); and enthesophyte presence (41% vs 3%; P < .001). Multivariate regression analysis of all variables showed that teardrop distance and enthesophyte presence were the 2 variables most predictive of abductor tears, and other variables did not significantly increase or decrease the likelihood of tear when these 2 variables were considered. The presence of an enthesophyte on the greater trochanter was notable for an odds ratio of 20.7 of having an abductor tear. Conclusions Patients with abductor tears have a wider pelvis, longer abductor moment arm, and longer body weight moment arm and have greater trochanteric enthesophyte as noted on nearly half of patients with an abductor tear. Presence of an enthesophyte was noted to have an odds ratio of 20.7 and a positive predictive value of 94% for having an abductor tendon tear. The 2 variables predictive of abductor tendon tear when controlling for all variables were enthesophyte presence and teardrop distance, with no other variables significantly increasing or decreasing the likelihood of tear when these 2 variables were considered. Level of Evidence Level III, retrospective comparative study.

OBJECTIVE Although it is still early in its application, laser interstitial thermal therapy (LiTT) has increasingly been employed as a surgical option for patients with mesial temporal lobe epilepsy. This study aimed to describe mesial temporal lobe ablation volumes and seizure outcomes following LiTT across the Mayo Clinic’s 3 epilepsy surgery centers. METHODS This was a multi-site, single-institution, retrospective review of seizure outcomes and ablation volumes following LiTT for medically intractable mesial temporal lobe epilepsy between October 2011 and October 2015. Pre-ablation and post-ablation follow-up volumes of the hippocampus were measured using FreeSurfer, and the volume of ablated tissue was also measured on intraoperative MRI using a supervised spline-based edge detection algorithm. To determine seizure outcomes, results were compared between those patients who were seizure free and those who continued to experience seizures. RESULTS There were 23 patients who underwent mesial temporal LiTT within the study period. Fifteen patients (65%) had left-sided procedures. The median follow-up was 34 months (range 12–70 months). The mean ablation volume was 6888 mm 3 . Median hippocampal ablation was 65%, with a median amygdala ablation of 43%. At last follow-up, 11 (48%) of these patients were seizure free. There was no correlation between ablation volume and seizure freedom (p = 0.69). There was also no correlation between percent ablation of the amygdala (p = 0.28) or hippocampus (p = 0.82) and seizure outcomes. Twelve patients underwent formal testing with computational visual fields. Visual field changes were seen in 67% of patients who underwent testing. Comparing the 5 patients with clinically noticeable visual field deficits to the rest of the cohort showed no significant difference in ablation volume between those patients with visual field deficits and those without (p = 0.94). There were 11 patients with follow-up neuropsychological testing. Within this group, verbal learning retention was 76% in the patients with left-sided procedures and 89% in those with right-sided procedures. CONCLUSIONS In this study, there was no significant correlation between the ablation volume after LiTT and seizure outcomes. Visual field deficits were common in formally tested patients, much as in patients treated with open temporal lobectomy. Further studies are required to determine the role of amygdalohippocampal ablation.

Medication reconciliation (MedRec) is a mission-critical process which can serve to reduce adverse drug events (ADEs) in surgical settings. However, providing quality care is limited by current health information technology (IT), which is often inefficient and unintuitive due to poor usability, resulting in high cognitive burden. We have been characterizing EHR mediated workflow in the Mayo Clinic enterprise prior to a system-wide electronic health records (EHR) conversion in order to harmonize workflows. We compared and evaluated MedRec processes in pre-operative nursing assessments across two different EHRs in place in different locales at baseline. The interfaces differed both in their modes of interaction and cognitive support. Analyses surfaced interface elements that were unintuitive and inefficient, creating unnecessary complexities in clinicians’ interactive behavior. Keystroke level models (KLM), a modeling tool for predicting task completion time, showed that to access medication lists required a different series of operations across the two systems. Different designs can differentially mediate task performance, which can aid in the mitigation of errors for complex cognitive tasks. Identification of barriers in EHR-mediated workflow and barriers to interface usability could lead to system redesigns that minimize cognitive load while improving patient safety and efficiency.

BACKGROUND: Revisional and reconstructive surgery for IPAA is rare given the high success of pouch surgery for chronic ulcerative colitis. Limited data exist on both surgical and functional outcomes in patients with chronic ulcerative colitis who undergo IPAA revision or reconstruction. OBJECTIVE: This study aimed to determine the surgical and functional outcome in patients with chronic ulcerative colitis who undergo IPAA revision or reconstruction. DESIGN: A prospectively collected surgical database was accessed for this study. SETTING: This study was conducted at an IBD referral center. PATIENTS: Patients with chronic ulcerative colitis who underwent IPAA revision or reconstruction were selected. MAIN OUTCOME MEASURES: The primary outcomes measured were 30-day postoperative outcomes and long-term pouch function. RESULTS: Eighty-one patients were identified. Original IPAA was performed for chronic ulcerative colitis (n = 71; 88%) and indeterminate colitis (n = 11; 12.%), and the most common configuration was a J-pouch (n = 69; 86%) with handsewn anastomosis (n = 41;68%). No independent predictors of 30-day postoperative complications following reconstructive/revisional surgery were identified. Pelvic abscesses and Crohn’s disease of the pouch were independently associated with ultimate pouch excision. Median follow-up following revision/reconstruction was 40 months (range, 1–292 months) during which 15 patients (23%) had pouch failure. The 5- and 10-year pouch survival rates following revision were 85 ± 5% and 65 ± 9% by Kaplan-Meier estimation; age <30 years was significantly associated with pouch survival. Long-term function (n = 30; 35%) compared with a matched control cohort of primary IPAA was characterized by significantly increased daytime bowel incontinence (p = 0.0119), liquid stool (p = 0.0062), and medication to thicken stools (p = 0.0452). LIMITATIONS: This was a single-center series, and response rate for functional data was 35%. CONCLUSIONS: In properly selected patients with a failing pouch, originally made for chronic ulcerative colitis or indeterminate colitis, revisional and reconstructive surgery is associated with low complication rates, high pouch salvage, and acceptable long-term pouch function. See Video Abstract at http://links.lww.com/DCR/A640.

The PREVENtion of HeartMate II pump Thrombosis through clinical management (PREVENT) study was a multicenter, prospective investigation to evaluate the rate of pump thrombosis (PT) with adoption of a uniform set of surgical and medical practices for left ventricular assist device implantation. We sought to quantify pump position at baseline and retrospectively define a pump position associated with poor clinical outcomes. Chest x-rays at baseline were prospectively obtained per protocol. Pump pocket depth, inflow cannula (IC) angle relative to the pump, and IC angle relative to the vertical were measured. Pumps falling in the tail-ends of the IC angle and pump pocket depth distributions were categorized as having an extreme pump position within the PREVENT study. Patients with extreme pump position had a significantly higher risk of confirmed and suspected PT, hemolysis, and elevated lactate dehydrogenase. In a multivariable analysis of survival free of confirmed PT, extreme pump position was an independent risk factor (hazard ratio = 3.6; 95% confidence interval = 1.5–8.9; p = 0.006) when adjusting for differences in pump speed and anticoagulation level. Our analysis shows that HeartMate II pump position at implant can significantly impact event-free survival and the incidence of adverse events at 6 months.

Small intestinal biopsy interpretation has been the cornerstone for the diagnosis of celiac disease for over 50 years. Despite the existence of sensitive and specific serological tests, duodenal mucosal biopsies continue to be obtained in the vast majority of patients in whom a diagnosis of celiac disease is being considered. The accurate evaluation of these biopsies requires coordination and information sharing between the gastroenterologist, laboratory, and pathologist in order to optimize tissue sampling, preparation and interpretation. This document, a collaboration between the Rodger C. Haggitt Gastrointestinal Pathology Society and the North American Association for the Study of Celiac Disease, is intended to provide clinicians and pathologists with a summary of best practices in the use of endoscopy and biopsy for patients with suspected celiac disease. The authors present a comprehensive and critical appraisal of the literature with respect to the topics of endoscopic findings, best methods for the obtaining biopsies, completing the pathology form and pathologic assessment, including evaluating intraepithelial lymphocytes and villous architecture. A discussion of conditions with overlapping pathologic findings in duodenal mucosal biopsies is presented. In order to provide additional guidance for challenging situations, the authors include an appendix containing practical suggestions. This review may be utilized in interdisciplinary discussions to optimize care for patients with possible celiac disease.

Objective: Determine the safety of overlapping surgery in a tertiary care colorectal surgery practice. Summary: Although overlapping surgery is common in academic centers, reports on outcomes of this practice are limited. The primary aim of this study was to investigate the safety of overlapping surgery in a dedicated tertiary care academic colorectal practice by comparing groups of patients who did or did not have their surgery performed in an overlapping fashion. Methods: Retrospective review of 1270 colorectal patients undergoing inpatient colorectal surgery at our institution. Eligible participants were all patients undergoing elective inpatient colorectal surgery by one of the colorectal surgeons at the Mayo Clinic Rochester between January 1, 2012 and December 31, 2015. Patients under the age of 18 or who underwent an emergent procedure were excluded. Data were abstracted using the American College of Surgeons National Quality Improvement Program (ACS-NSQIP) database. Additionally, each subject's chart was reviewed and further abstracted. The safety of overlapping surgery on outcomes was assessed using multiple multivariable models. Results: One thousand two hundred seventy patients were included in the study cohort of whom 50.7% were female and the average age was 55.4 years. Overlapping surgery occurred in 576 patients (45%). There were no significant differences in demographic, surgical indications, procedures, or operative complexity between patients undergoing overlapping surgery and those who did not. Overall adverse events were significantly less likely in patients undergoing overlapping surgery compared with those who did not (18.4% vs 23.6%, P = 0.02). We found that overlapping surgery was associated with significantly less adverse events compared with patients not undergoing overlapping surgery using a model that controlled for the effect of the individual surgeon (OR 0.7, 95% CI 0.6 – 0.96; P = .02) and a multivariable propensity score (OR 0.7, 95% CI 0.5– 0.9; P = 01). Conclusions: Overlapping surgery in a tertiary care colorectal practice is safe and not associated with adverse patient outcomes.