Explainable Machine Learning Model to Preoperatively Predict Postoperative Complications in Inpatients With Cancer Undergoing Major Operations

PURPOSE

Preoperative prediction of postoperative complications (PCs) in inpatients with cancer is challenging. We developed an explainable machine learning (ML) model to predict PCs in a heterogenous population of inpatients with cancer undergoing same-hospitalization major operations.

METHODS

Consecutive inpatients who underwent same-hospitalization operations from December 2017 to June 2021 at a single institution were retrospectively reviewed. The ML model was developed and tested using electronic health record (EHR) data to predict 30-day PCs for patients with Clavien-Dindo grade 3 or higher (CD 3+) per the CD classification system. Model performance was assessed using area under the receiver operating characteristic curve (AUROC), area under the precision recall curve (AUPRC), and calibration plots. Model explanation was performed using the Shapley additive explanations (SHAP) method at cohort and individual operation levels.

RESULTS

A total of 988 operations in 827 inpatients were included. The ML model was trained using 788 operations and tested using a holdout set of 200 operations. The CD 3+ complication rates were 28.6% and 27.5% in the training and holdout test sets, respectively. Training and holdout test sets' model performance in predicting CD 3+ complications yielded an AUROC of 0.77 and 0.73 and an AUPRC of 0.56 and 0.52, respectively. Calibration plots demonstrated good reliability. The SHAP method identified features and the contributions of the features to the risk of PCs.

CONCLUSION

We trained and tested an explainable ML model to predict the risk of developing PCs in patients with cancer. Using patient-specific EHR data, the ML model accurately discriminated the risk of developing CD 3+ complications and displayed top features at the individual operation and cohort level.

Recurrence patterns after complex multimodality therapy and hepatic arterial infusion for colorectal liver metastases: A reflection of biology and technique

BACKGROUND AND METHODS

We characterized colorectal liver metastasis recurrence and survival patterns after surgical resection and intraoperative ablation ± hepatic arterial infusion pump (HAIP) placement. We estimated patterns of recurrence and survival in patients undergoing contemporary multimodal treatments. Between 2017 and 2021, patient, tumor characteristics, and recurrence data were collected. Primary outcomes included recurrence patterns and survival data based on operative intervention.

RESULTS

There were 184 patients who underwent hepatectomy and intraoperative ablation. Sixty patients (32.6%) underwent HAIP placement. A total of 513 metastases were ablated, median total of 2 ablations per patient. Median time to recurrence was 31 [22-40] months. Recurrence patterns included tumor at ablative margin on first scheduled postoperative imaging (8, 4.3%), local tumor recurrence at ablative site (69, 37.5%), and non-ablated liver tumor recurrence (38, 20.6%). In patients who underwent HAIP placement, the rate of liver recurrence was reduced (45% vs 70.9%, p = 0.0001). Median overall survival was 64 [41-58] months and prolonged survival was associated with HAIP treatment (85 [66-109] vs 60 [51-70] months.

CONCLUSIONS AND DISCUSSION

Hepatic recurrence is common and combination of intraoperative ablation and HAIP treatments were associated with prolonged survival. These data may reflect patient selection however, future work will clarify preoperative tumor and patient characteristics that may better predict recurrence expectations.

Pilot study of HER2 targeted 64 Cu-DOTA-tagged PET imaging in gastric cancer patients

OBJECTIVE

Human epidermal growth factor receptor 2 (HER2) is an important biomarker for targeted gastric cancer (GC) immunotherapy. However, heterogeneous HER2 overexpression in GC, loss of HER2 expression during therapy, and inability to non-invasively identify HER2 overexpressing tumors impede effective targeting therapies. Improved HER2-specific functional imaging can address these challenges. Trastuzumab is a HER2-directed mAb to treat HER2 overexpressing cancers. The 64 Cu-DOTA-trastuzumab radiotracer is used to detect HER2+ metastatic breast cancer. We aimed to develop 64 Cu-DOTA-trastuzumab PET-CT to detect and characterize tumor uptake in HER2+ or - GC patients.

METHODS

We conducted a single-arm phase II pilot study exploring the feasibility of 64 Cu-DOTA-trastuzumab for PET imaging of HER2 overexpressing GC compared to HER2 non-expressing tumors. Eight patients with biopsy-confirmed gastric adenocarcinoma were included. Immunohistochemistry was used to evaluate primary tumor biopsies for HER2 overexpression. Patients were injected with 45 mg of cold trastuzumab followed by 5 mg of 64 Cu-DOTA-trastuzumab. PET-CT scans were performed 24-48 h post radiotracer injection and compared to standard staging CT scans.

RESULTS

We observed limited toxicity following 64 Cu-DOTA-trastuzumab injections. While there was uptake of the radiotracer in portions of HER2+ lesions, there was no statistically significant distinction between tumor and background by standardized uptake value analysis.

CONCLUSION

Despite the potential of 64 Cu-DOTA-trastuzumab PET imaging of HER2+ metastatic breast cancer, a 5 mg dose of this radiotracer injected 24-48 h before imaging was insufficient to identify HER2+ GC. These results inform future GC imaging studies to optimize biomarker-targeted therapies based on dosage and timing for more clinically relevant imaging.

Therapeutic Efficacy of Temsirolimus in a Patient-derived Model of Metastatic Fibrolamellar Hepatocellular Carcinoma

BACKGROUND/AIM

Fibrolamellar hepatocellular carcinoma (FLHCC) is a rare tumor presenting in younger patients without chronic liver disease. Up to 80-100% develop recurrent disease, necessitating additional surgery or systemic treatment. Systemic options and pre-clinical treatment studies are lacking. We previously described patient-derived xenograft (PDX) development, allowing for pre-clinical studies. Herein, we develop FLHCC PDX models and utilize these to define tumor characteristics and determine the efficacy of systemic agents.

MATERIALS AND METHODS

Primary and lymph node metastatic tumor tissues were obtained at the time of FLHCC resection in two patients. Tumor lysates were screened for protein upregulation. Cell lines were generated from metastatic and primary tumor tissue. The viability of the cell lines was assessed after treatment with temsirolimus, gemcitabine/oxaliplatin, and FOLFIRINOX. Two PDX models were developed from metastatic tissue. For in vivo studies, tumor-bearing mice were treated with temsirolimus, FOLFIRINOX, and Gemcitabine/oxaliplatin.

RESULTS

PDX models were successfully generated from metastatic FLHCC, which closely recapitulated the original tumor. Upregulation of mTOR was seen in metastatic tissue compared to primary tumors. Cell lines from metastatic tissue demonstrated significant sensitivity to temsirolimus. In vivo testing of PDX models demonstrated a significant response to single-agent temsirolimus with minimal toxicity.

CONCLUSION

Herein, we demonstrate the feasibility of developing PDX models that closely recapitulate FLHCC. Upregulation of mTOR was seen in metastatic tissue compared to primary tissue. The efficacy of mTOR inhibition with temsirolimus treatment suggests that the upregulation of the mTOR pathway may be a significant mechanism for growth in metastatic lesions and a potential target for therapeutics.

Low anterior resection syndrome

Low anterior resection syndrome represents a clinical state wherein a constellation of gastrointestinal symptoms is a direct result of anatomic changes to the rectum. Patients who undergo operations to create a neorectum often develop persistent symptoms of increased frequency, urgency, diarrhea, and these symptoms are debilitating and impact patients' quality of life. A stepwise approach to treatment can improve many patients' symptoms with the most invasive options reserved for highly refractory symptoms.

Legal Firearm Sales at State Level and Rates of Violent Crime, Property Crime, and Homicides

INTRODUCTION

The effects of firearm sales and legislation on crime and violence are intensely debated, with multiple studies yielding differing results. We hypothesized that increased lawful firearm sales would not be associated with the rates of crime and homicide when studied using a robust statistical method.

METHODS

National and state rates of crime and homicide during 1999-2015 were obtained from the United States Department of Justice and the Centers for Disease Control and Prevention. National Instant Criminal Background Check System background checks were used as a surrogate for lawful firearm sales. A general multiple linear regression model using log event rates was used to assess the effect of firearm sales on crime and homicide rates. Additional modeling was then performed on a state basis using an autoregressive correlation structure with generalized estimating equation estimates for standard errors to adjust for the interdependence of variables year to year within a particular state.

RESULTS

Nationally, all crime rates except the Centers for Disease Control and Prevention-designated firearm homicides decreased as firearm sales increased over the study period. Using a naive national model, increases in firearm sales were associated with significant decreases in multiple crime categories. However, a more robust analysis using generalized estimating equation estimates on state-level data demonstrated increases in firearms sales were not associated with changes in any crime variables examined.

CONCLUSIONS

Robust analysis does not identify an association between increased lawful firearm sales and rates of crime or homicide. Based on this, it is unclear if efforts to limit lawful firearm sales would have any effect on rates of crime, homicide, or injuries from violence committed with firearms.

Validation of the American Association for the Surgery of Trauma Emergency General Surgery Grading System for Colorectal Resection: An EAST Multicenter Study

BACKGROUND

The American Association for the Surgery of Trauma (AAST) has developed a grading system for emergency general surgery (EGS) conditions. We sought to validate the AAST EGS grades for patients undergoing urgent/emergent colorectal resection.

METHODS

Patients enrolled in the "Eastern Association for the Surgery of Trauma Multicenter Colorectal Resection in EGS-to anastomose or not to anastomose" study undergoing urgent/emergent surgery for obstruction, ischemia, or diverticulitis were included. Baseline demographics, comorbidity severity as defined by Charlson comorbidity index (CCI), procedure type, and AAST grade were prospectively collected. Outcomes included length of stay (LOS) in-hospital mortality, and surgical complications (superficial/deep/organ-space surgical site infection, anastomotic leak, stoma complication, fascial dehiscence, and need for further intervention). Multivariable logistic regression models were used to describe outcomes and risk factors for surgical complication or mortality.

RESULTS

There were 367 patients, with a mean (± SD) age of 62 ± 15 years. 39% were women. The median interquartile range (IQR) CCI was 4 (2-6). Overall, the pathologies encompassed the following AAST EGS grades: I (17, 5%), II (54, 15%), III (115, 31%), IV (95, 26%), and V (86, 23%). Management included laparoscopic (24, 7%), open (319, 87%), and laparoscopy converted to laparotomy (24, 6%). Higher AAST grade was associated with laparotomy (P = .01). The median LOS was 13 days (8-22). At least 1 surgical complication occurred in 33% of patients and the mortality rate was 14%. Development of at least 1 surgical complication, need for unplanned intervention, mortality, and increased LOS were associated with increasing AAST severity grade. On multivariable analysis, factors predictive of in-hospital mortality included AAST organ grade, CCI, and preoperative vasopressor use (odds ratio (OR) 1.9, 1.6, 3.1, respectively). The American Association for the Surgery of Trauma emergency general surgery grade was also associated with the development of at least 1 surgical complication (OR 2.5), while CCI, preoperative vasopressor use, respiratory failure, and pneumoperitoneum were not.

CONCLUSION

The American Association for the Surgery of Trauma emergency general surgery grading systems display construct validity for mortality and surgical complications after urgent/emergent colorectal resection. These results support incorporation of AAST EGS grades for quality benchmarking and surgical outcomes research.

Small bowel obstruction managed without hospital admission: A safe way to reduce both cost and time in the hospital?

BACKGROUND

Small bowel obstruction management has evolved to incorporate the Gastrografin challenge. We expanded its use to the emergency department observation unit, potentially avoiding hospital admission for highly select small bowel obstruction patients. We hypothesized that the emergency department observation unit small bowel obstruction protocol would reduce admissions, costs, and the total time spent in the hospital without compromising outcomes.

METHODS

We reviewed patients who presented with small bowel obstruction from January 2015 to December 2018. Patients deemed to require urgent surgical intervention were admitted directly and excluded. The emergency department observation unit small bowel obstruction guidelines were introduced in November 2016. Patients were divided into pre and postintervention groups based on this date. The postintervention group was further subclassified to examine the emergency department observation unit patients. Cost analysis for each patient was performed looking at number of charges, direct costs, indirect cost, and total costs during their admission.

RESULTS

In total, 125 patients were included (mean age 69 ± 14.3 years). The preintervention group (n = 62) and postintervention group (n = 63) had no significant difference in demographics. The postintervention group had a 51% (36.7 hours, P < .001) reduction in median duration of stay and a total cost reduction of 49% (P < .001). The emergency department observation unit subgroup (n = 46) median length of stay was 23.6 hours. The readmission rate was 16% preintervention compared to 8% in the postintervention group (P = .18).

CONCLUSION

Management of highly selected small bowel obstruction patients with the emergency department observation unit small bowel obstruction protocol was associated with decreased length of stay and total cost, without an increase in complications, surgical intervention, or readmissions.

Association of scooter-related injury and hospitalization with electronic scooter sharing systems in the United States

INTRODUCTION

We used interrupted time series (ITS) analysis to determine whether e-scooter shares' introduction in September 2017 increased serious scooter-related injury across the United States.

METHODS

Using the National Electronic Injury Surveillance System, we queried emergency department visits involving motorized scooter-related injuries from January 2010-December 2019. Cases originating where e-scooter shares launched between September 1, 2017-December 1, 2019 (intervention period) were considered exposed. The first month of launch (September 2017) was chosen as the time point for pre- and post-intervention analysis. The primary outcome was change in hospitalizations following scooter injury in association with the month/year launch.

RESULTS

This analysis includes 2754 unweighted encounters, representing 102614 estimated injuries involving motorized scooters nationwide. Hospitals within 20 miles of e-scooter shares also experienced a significant monthly increase of 0.24 scooter-related injury hospitalizations/1000 product-related injury hospitalizations ([0.17,0.31]) compared to a non-significant change in hospitalizations of 0.02 [-0.05,0.09] for control hospitals.

CONCLUSION

An increase in serious motorized scooter injuries coincides with e-scooter shares' introduction in the US. Future works should explore effective polices to improve public safety.

Surgical stabilization of rib fractures in octogenarians and beyond-what are the outcomes?

BACKGROUND

Prospective studies of surgical stabilization of rib fractures (SSRF) have excluded elderly patients, and no study has exclusively addressed the ≥80-year-old subgroup. We hypothesized that SSRF is associated with decreased mortality in trauma patients 80 years or older.

METHODS

Multicenter retrospective cohort study involving eight centers. Patients who underwent SSRF from 2015 to 2020 were matched to controls by study center, age, injury severity score, and presence of intracranial hemorrhage. Patients with chest Abbreviated Injury Scale score less than 3, head Abbreviated Injury Scale score greater than 2, death within 24 hours, and desire for no escalation of care were excluded. A subgroup analysis compared early (0-2 days postinjury) to late (3-7 days postinjury) SSRF. Poisson regression accounting for clustered data by center calculated the relative risk (RR) of the primary outcome of mortality for SSRF versus nonoperative management.

RESULTS

Of 360 patients, 133 (36.9%) underwent SSRF. Compared with nonoperative patients, SSRF patients were more severely injured and more likely to receive locoregional analgesia. There were 31 hospital deaths among the entire sample (8.6%). Multivariable regression demonstrated a decreased risk of mortality for the SSRF group, as compared with the nonoperative group (RR, 0.41; 95% confidence interval, 0.24-0.69; p < 0.01). However, SSRF patients were more likely to develop pneumonia, and had an increased duration of both mechanical ventilation and intensive care unit stay. There were no differences in discharge destination, although the SSRF group was less likely to be discharged on narcotics (RR, 0.66; 95% confidence interval, 0.48-0.90; p = 0.01). There was no difference in adjusted mortality between the early and late SSRF subgroups.

CONCLUSION

Patients selected for SSRF were substantially more injured versus those managed nonoperatively. Despite this, SSRF was independently associated with decreased mortality. With careful patient selection, SSRF may be considered a viable treatment option in octogenarian/nonagenarians.

LEVEL OF EVIDENCE

Therapeutic, Level IV.

CT-derived sarcopenia should not preclude surgical stabilization of traumatic rib fractures

BACKGROUND

Rib fractures are associated with considerable morbidity and mortality. Surgical stabilization of rib fractures (SSRF) can be performed to mitigate complications. Sarcopenia is in general known to be associated with poor clinical outcomes. We investigated if sarcopenia impacted number of days of mechanical ventilation, intensive care unit (ICU) stay, and total hospital stay in patients who underwent SSRF.

METHODS

A retrospective single institutional review was performed including patients who underwent SSRF (2009-2017). Skeletal muscle index (SMI) was semiautomatically calculated at the L3 spinal level on computed tomography (CT) images and normalized by patient height. Sarcopenia was defined as SMI < 55 cm²/m² in males and < 39 cm²/m² in females. Demographics, operative details, and postoperative outcomes were reviewed. Univariate and multivariate analyses were performed.

RESULTS

Of 238 patients, 88 (36.9%) had sarcopenia. There was no significant difference in number of days of mechanical ventilation (2.8 ± 4.9 versus 3.1 ± 4.3, p = 0.304), ICU stay (5.9 ± 6.5 versus 4.9 ± 5.7 days, p = 0.146), or total hospital stay (13.3 ± 7.2 versus 12.9 ± 8.2 days, p = 0.183) between sarcopenic and nonsarcopenic patients. Sarcopenic patients demonstrated increased modified frailty index scores (1.5 ± 1.1 versus 0.9 ± 0.9, p < 0.001) compared to nonsarcopenic patients.

CONCLUSIONS

For patients who underwent SSRF for rib fractures, sarcopenia did not increase the number of days of mechanical ventilation, ICU stay, or total hospital stay. Sarcopenia should not preclude the utilization of SSRF in these patients.

Comparison of the Pediatric Resuscitation and Trauma Outcome (PRESTO) Model and Pediatric Trauma Scoring Systems in a Middle-Income Country

BACKGROUND

The pediatric resuscitation and trauma outcome (PRESTO) model was developed to aid comparisons of risk-adjusted mortality after injury in low- and middle-income countries (LMICs). We sought to validate PRESTO using data from a middle-income country (MIC) trauma registry and compare its performance to the Pediatric Trauma Score (PTS), Revised Trauma Score, and pediatric age-adjusted shock index (SIPA).

METHODS

We included children (age < 15 years) admitted to a single trauma center in South Africa from December 2012 to January 2019. We excluded patients missing variables necessary for the PRESTO model-age, systolic blood pressure, pulse, oxygen saturation, neurologic status, and airway support. Trauma scores were assigned retrospectively. PRESTO's previously high-income country (HIC)-validated optimal threshold was compared to MIC-validated threshold using area under the receiver operating characteristic curves (AUROC). Prediction of in-hospital death using trauma scoring systems was compared using ROC analysis.

RESULTS

Of 1160 injured children, 988 (85%) had complete data for calculation of PRESTO. Median age was 7 (IQR: 4, 11), and 67% were male. Mortality was 2% (n = 23). Mean predicted mortality was 0.5% (range 0-25.7%, AUROC 0.93). Using the HIC-validated threshold, PRESTO had a sensitivity of 26.1% and a specificity of 99.7%. The MIC threshold showed a sensitivity of 82.6% and specificity of 89.4%. The MIC threshold yielded superior discrimination (AUROC 0.86 [CI 0.78, 0.94]) compared to the previously established HIC threshold (0.63 [CI 0.54, 0.72], p < 0.0001). PRESTO showed superior prediction of in-hospital death compared to PTS and SIPA (all p < 0.01).

CONCLUSION

PRESTO can be applied in MIC settings and discriminates between children at risk for in-hospital death following trauma. Further research should clarify optimal decision thresholds for quality improvement and benchmarking in LMIC settings.

North American pediatric surgery fellows' preparedness for humanitarian surgery

INTRODUCTION

The overwhelming burden of pediatric surgical need in humanitarian settings has prompted mutual interest between humanitarian organizations and pediatric surgeons. To assess adequate fit, we correlated pediatric surgery fellowship case mix and load with acute pediatric surgical relief efforts in conflict and disaster zones.

METHODS

We reviewed pediatric (age < 18) cases logged by the Médecins Sans Frontières Operational Centre Brussels (MSF-OCB) from a previously validated and published database spanning 2008-2014 and cases performed by American College of Graduate Medical Education (ACGME) pediatric surgery graduates from 2008 to 2018. Non-operative management for trauma, endoscopic procedures, and basic wound care were excluded as they were not tracked in either dataset. ACGME procedures were classified under 1 of 32 MSF pediatric surgery procedure categories and compared using chi-squared tests.

RESULTS

ACGME fellows performed procedures in 44% of tracked MSF-OCB categories. Major MSF-OCB pediatric cases were comprised of 62% general surgery, 23% orthopedic surgery, 9% obstetrical surgery, 3% plastic/reconstructive surgery, 2% urogynecologic surgery, and 1% specialty surgery. In comparison, fellows' cases were 95% general surgery, 0% orthopedic surgery, 0% obstetrical surgery, 5% urogynecologic surgery, and 1% specialty surgery. Fellows more frequently performed abdominal, thoracic, other general surgical, urology/gynecologic, and specialty procedures, but performed fewer wound and burn procedures (all p < 0.05). Fellows received no experience in Cesarean section or open fracture repair. Fellows performed a greater proportion of surgeries for congenital conditions (p < 0.05).

CONCLUSION

While ACGME pediatric surgical trainees receive significant training in general and urogynecologic surgical techniques, they lack sufficient case load for orthopedic and obstetrical care - a common need among children in humanitarian settings. Trainees and program directors should evaluate the fellow's role and scope in a global surgery rotation or provide advanced preparation to fill these gaps. Upon graduation, pediatric surgeons interested in humanitarian missions should seek out additional orthopedic and obstetrical training, or select missions that do not require such skillsets.

LEVEL OF EVIDENCE

III.

Genomic and Epigenomic Landscaping Defines New Therapeutic Targets for Adenosquamous Carcinoma of the Pancreas

Adenosquamous cancer of the pancreas (ASCP) is a subtype of pancreatic cancer that has a worse prognosis and greater metastatic potential than the more common pancreatic ductal adenocarcinoma (PDAC) subtype. To distinguish the genomic landscape of ASCP and identify actionable targets for this lethal cancer, we applied DNA content flow cytometry to a series of 15 tumor samples including five patient-derived xenografts (PDX). We interrogated purified sorted tumor fractions from these samples with whole-genome copy-number variant (CNV), whole-exome sequencing, and Assay for Transposase-Accessible Chromatin using sequencing (ATAC-seq) analyses. These identified a variety of somatic genomic lesions targeting chromatin regulators in ASCP genomes that were superimposed on well-characterized genomic lesions including mutations in TP53 (87%) and KRAS (73%), amplification of MYC (47%), and homozygous deletion of CDKN2A (40%) that are common in PDACs. Furthermore, a comparison of ATAC-seq profiles of three ASCP and three PDAC genomes using flow-sorted PDX models identified genes with accessible chromatin unique to the ASCP genomes, including the lysine methyltransferase SMYD2 and the pancreatic cancer stem cell regulator RORC in all three ASCPs, and a FGFR1-ERLIN2 fusion associated with focal CNVs in both genes in a single ASCP. Finally, we demonstrate significant activity of a pan FGFR inhibitor against organoids derived from the FGFR1-ERLIN2 fusion-positive ASCP PDX model. Our results suggest that the genomic and epigenomic landscape of ASCP provide new strategies for targeting this aggressive subtype of pancreatic cancer. SIGNIFICANCE: These data provide a unique description of the ASCP genomic and epigenomic landscape and identify candidate therapeutic targets for this dismal cancer.

Damage Control Laparotomy: High-Volume Centers Display Similar Mortality Rates Despite Differences in Country Income Level

BACKGROUND

Comprehensive analysis of trauma care between high-, middle-, and low-income countries (HIC/MIC/LIC) is needed to improve global health. Comparison of HIC and MIC outcomes after damage control laparotomy (DCL) for patients is unknown. We evaluated DCL utilization among patients treated at high-volume trauma centers in the USA and South Africa, an MIC, hypothesizing similar mortality outcomes despite differences in resources and setting.

METHODS

Post hoc analysis of prospectively collected trauma databases from participating centers was performed. Injury severity, physiologic, operative data and post-operative outcomes were abstracted. Univariate and multivariable analyses were performed to assess differences between HIC/MIC for the primary outcome of mortality.

RESULTS

There were 967 HIC and 602 MIC patients who underwent laparotomy. DCL occurred in 144 MIC patients (25%) and 241 HIC (24%) patients. Most sustained (58%) penetrating trauma with higher rates in the MIC compared to the HIC (71 vs. 32%, p = 0.001). Between groups, no differences were found for admission physiology, coagulopathy, or markers of shock except for increased presence of hypotension among patients in the HIC. Crystalloid infusion volumes were greater among MIC patients, and MIC patients received fewer blood products than those in the HIC. Overall mortality was 30% with similar rates between groups (29 in HIC vs. 33% in MIC, p = 0.4). On regression, base excess and penetrating injury were independent predictors of mortality but not patient residential status.

CONCLUSION

Use and survival of DCL for patients with severe abdominal trauma was similar between trauma centers in HIC and MIC settings despite increased penetrating trauma and less transfusion in the MIC center. While the results overall suggest no gap in care for patients requiring DCL in this MIC, it highlights improvements that can be made in damage control resuscitation.

Disease Severity and Cost in Adhesive Small Bowel Obstruction

BACKGROUND

Adhesive small bowel obstruction (ASBO) severity has been associated with important clinical outcomes. However, the impact of ASBO severity on hospitalization cost is unknown. The American Association for the Surgery of Trauma (AAST) developed an Emergency General Surgery (EGS) disease severity grading system for ASBO. We stratified patients' ASBO severity and captured hospitalization costs hypothesizing that increased disease severity would correlate with greater costs.

METHODS

This was a single-center study of hospitalized adult patients with SBO during 2015-2017. Clinical data and estimated total cost (direct + indirect) were abstracted. AAST EGS grades (I-IV) stratified disease severity. Costs were normalized to the median grade I cost. Univariate and multivariate analyses evaluated the relationship between normalized cost and AAST EGS grade, length of hospital and ICU stay, operative time, and Charlson comorbidity index.

RESULTS

There were 214 patients; 119 (56%) were female. AAST EGS grades included: I (62%, n = 132), II (23%, n = 49), III (7%, n = 16), and IV (8%, n = 17). Relative to grade I, median normalized cost increased by 1.4-fold for grade II, 1.6-fold for grade III, and 4.3-fold for grade IV disease. No considerable differences in patient comorbidity between grades were observed. Pair-wise comparisons demonstrated that grade I disease cost less than higher grades (corrected p < 0.001). Non-operative management was associated with lower normalized cost compared to operative management (1.1 vs. 4.5, p < 0.0001). In patients who failed non-operative management, normalized cost was increased 7.2-fold. Collectively, the AAST EGS grade correlated well with cost (Spearman's p = 0.7, p < 0.0001). After adjustment for covariates, AAST EGS grade maintained a persistent relationship with cost.

CONCLUSION

Increasing ASBO severity is independently associated with greater costs. Efforts to identify and mitigate costs associated with this burdensome disease are warranted.

LEVEL OF EVIDENCE

III, economic/decision.

Reduced Opioid Prescription Practices and Duration of Stay after TAP Block for Laparoscopic Appendectomy

BACKGROUND

We evaluated whether TAP blocks performed at the time of appendectomy resulted in reduced total oral morphine equivalent (OME) prescribed and fewer 30-day opioid prescription (OP) refills.

STUDY DESIGN

Single institution review of historical data (2010-2016) was performed. Adults (≥ 18 years) that underwent appendectomy for appendicitis with uniform disease severity (AAST EGS grades I, II) were included. Opioid tolerance was defined as any preoperative OP ordered 1-3 months prior to appendectomy or < 1 month unrelated to appendicitis; opioid naïve patients were without OP. Intraoperative TAP blocks (admixture of liposomal/regular bupivacaine) were performed at surgeon discretion. Risk factors for discharge prescription > 200 OME were assessed using logistic regression and quantified using odds ratios (OR) and 95% confidence intervals (CI).

RESULT

There were 960 patients with uniform appendicitis severity. During appendectomy, 145 (15%) patients received TAP blocks. There were 46 patients that were opioid tolerant (5%) and the majority of the cohort received discharge OP (n = 914, 95%) with a median prescription OME volume of 225 [150-300]. Only 76 patients required 30-day opioid prescription refill. On regression, factors associated with a discharge prescription > 200 OME included ≥ 65 years of age (OR 0.64 (95%CI 0.41-0.98)) and no TAP block (OR 1.7 (95%CI 1.2-2.5)) but not preoperative opioid utilization.

CONCLUSIONS

TAP blocks in low-grade appendicitis were associated with reduced OME prescribed, hospital duration of stay, and fewer refills without impacting operative time or total hospital costs.

Surgical Considerations for Pediatric Snake Bites in Low- and Middle-Income Countries

BACKGROUND

Snake envenomation is associated with major morbidity especially in low- and middle-income countries and may require fasciotomy. We determined patient factors associated with the need for fasciotomy after venomous snake bites in children located in KwaZulu-Natal, South Africa.

METHODS

Single institutional review of historical data (2012-2017) for children (<18 years) sustaining snake envenomation was performed. Clinical data, management, and outcomes were abstracted. Syndromes after snake bite were classified according to Blaylock nomenclature: progressive painful swelling (PPS), progressive weakness (PW), or bleeding (B), as it is difficult to reliably identify the species of snake after a bite. Comparative and multivariable analyses to determine factors associated with fasciotomy were performed.

RESULTS

There were 72 children; mean age was 7 (±3) years, 59% male. Feet were most commonly affected (n = 27, 38%) followed by legs (n = 18, 25%). Syndromes (according to Blaylock) included PPS (n = 63, 88%), PW (n = 5, 7%), and B (n = 4, 5%). Eighteen patients underwent fasciotomy, and one required above knee amputation. Nine patients received anti-venom. Few patients (15%) received prophylactic beta-lactam antibiotics. Hemoglobin < 11 mg/dL, leukocytosis, INR >1.2, and age-adjusted shock index were associated with fasciotomy. On regression, age-adjusted shock index and hemoglobin concentration < 11 mg/dL, presentation >24 h after snake bite, and INR >1.2 were independently associated with fasciotomy. Model sensitivity was 0.89 and demonstrated good fit.

CONCLUSIONS

Patient factors were associated with the fasciotomy. These factors, coupled with clinical examination, may identify those who need early operative intervention. Improving time to treatment and the appropriate administration of anti-venom will minimize the need for surgery.

LEVEL OF EVIDENCE

III.

Survey of medical center employees' willingness and availability to donate blood in support of a civilian warm fresh whole blood program

OBJECTIVES

In military settings, utilizing warm fresh whole blood (WFWB) was associated with reduced mortality; however, there are multiple challenges for administering WFWB to civilians. The authors aimed to determine barriers to hospital employees emergently donating to civilian WFWB programs.

METHODS

We surveyed hospital employee willingness to donate emergently, familiarity with blood donation, and queried baseline demographics. The electronic survey was disseminated to a random sample of employees. Descriptive and univariate analyses were performed.

RESULTS

Three thousand surveys were sent; 883 were returned (28 percent). The majority of respondents were female (n = 630, 71 percent). Respondent familiarity with WFWB donation included very/somewhat familiar (n = 381, 43 percent) and somewhat-not/not-at-all familiar (n = 356, 40 percent). Most were definitely or somewhat willing to emergently donate (n = 660, 75 percent). Four hundred and sixty would drive from home to donate (52 percent). The majority worked day-time shifts (n = 754, 85 percent). In regards to donation history, 366 (41 percent) had donated blood more than ten times, but 138 (16 percent) had never donated. Barriers to emergent donation were identified (55 percent), with the most common being childcare responsibilities (n = 242; 27 percent).

CONCLUSIONS

Hospital employees are willing to donate WFWB emergently, but program implementation must address donor availability and logistical barriers. Future research should assess feasibility of a civilian WFWB program by determining regulatory challenges, development of a quality system for emergency donations, assessment of optimal workforce structure, potential impact to the general blood inventory, as well as patient and community perspectives regarding untested blood units.

Vaccination and splenectomy in Olmsted County

OBJECTIVES

To determine the long-term impact of vaccination on any postoperative infection in adults who underwent splenectomy.

METHODS

All adults (≥18 years) who underwent splenectomy from 1965 to 2011 in Olmsted County, MN were identified using the Rochester Epidemiology Project. Descriptive statistics, Kaplan-Meier estimates, and Cox proportional hazard ratios were performed.

RESULTS

There were 724 patients who underwent splenectomy; 47% were female with a median age of 55 (35-69) years. Overall vaccination rate (pneumococcal, H influenza, meningococcal) was 62% (n = 449). There were 268 (36%) patients who developed a post-splenectomy infection; most presented with sepsis 148 (55%). The 3 most common infections included pneumonia (124, 17%), bloodstream (67, 9%), and urinary tract infection (49, 7%). Median time to infection was quicker in non-vaccinated compared with vaccinated patients (1.5 [0.1-4.3] vs 3.3 [1.9-9.8] years, P = .01).

CONCLUSION

In this population-based study, the highest risk of infection after splenectomy was in patients who did not receive complete vaccination. Lack of complete vaccination was associated with a reduced time to infection and increased rates of bloodstream infections at 5 years. Infectious complication risk reduced as vaccination protocols improved for all indications except for malignancy. Adults who underwent a splenectomy should continue to receive booster vaccines.

Trauma registry data as a tool for comparison of practice patterns and outcomes between low- and middle-income and high-income healthcare settings

PURPOSE

There is a lack of data-driven, risk-adjusted mortality estimates for injured children outside of high-income countries (HIC). To inform injury prevention and quality improvement efforts, an upper middle-income country (UMIC) pediatric trauma registry was compared to that of a HIC.

METHODS

Clinical data, injury details, and mortality of injured children (< 18 years) hospitalized in two centers (USA and South African (SA)) from 2013 to 2017 were abstracted. Univariate and multivariable analyses evaluated risk of mortality and were expressed as odds ratios (OR) with 95% confidence intervals (CI).

RESULTS

Of 2089 patients, SA patients had prolonged transfer times (21.1 vs 3.4 h) and were more likely referred (78.2% vs 53.9%; both p < 0.001). Penetrating injuries were more frequent in SA (23.2% vs 7.4%, p < 0.001); injury severity (9 vs 4) and shock index (0.90 vs 0.80) were greater (both p < 0.001). SA utilized cross-sectional imaging more frequently (66.4% vs 37.3%, p < 0.001). In-hospital mortality was similar (1.9% SA, 1.3% USA, p = 0.31). Upon multivariable analysis, ISS > 25 [210.50 (66.0-671.0)] and penetrating injury [5.5 (1.3-23.3)] were associated with mortality, while institution [1.7 (0.7-4.2)] was not.

CONCLUSIONS

Despite transfer time, the centers demonstrated comparable survival rates. Comparison of registry data can alert clinicians to problematic practice patterns, assisting initiatives to improve trauma systems.

Outcomes after splenectomy in children: a 48-year population-based study

PURPOSE

In children who have undergone splenectomy, there may be impaired immunologic function and an increased risk of infection. We aimed to define the long-term rate of and risk factors for post-splenectomy infection using a population-based cohort study.

METHODS

All children (< 18 years) who underwent splenectomy from 1966 to 2011 in Olmsted County, MN were identified using the Rochester Epidemiology Project (REP). Descriptive statistics, Kaplan-Meier estimates, and Cox Proportional hazard ratios were performed to evaluate for risk factors associated with developing infection.

RESULTS

Ninety patients underwent splenectomy and 46% were female. Indications included trauma (42%), benign hematologic disease (33%), malignancy (13%), and other (11%). Most were performed open. Vaccination was completed in (72%) for pneumococcal, H. influenza, and meningococcal vectors. Nineteen patients developed infection, and associated factors included non-traumatic, non-malignant disease [HR 4.83 (1.18-19.85)], and performance of multiple surgical procedures [HR 2.80 (1.09-7.21)]. Estimated survival free of infection rates at 15 and 20 years following surgery was both 97%.

CONCLUSIONS

After splenectomy in children, most patients do not develop infection. Nearly three-quarters of patients were vaccinated with the lowest rates in patients that underwent a splenectomy for trauma. In patients who received multiple procedures during a splenectomy, the infection risk was higher.

Patient-Derived Xenografts Can Be Reliably Generated from Patient Clinical Biopsy Specimens

BACKGROUND

Patient-derived xenografts (PDX) are clinically relevant human cancer models that can be used to guide individualized medicine. We aimed to generate PDX models from clinically obtained biopsy specimens (surgical or image-guided) hypothesizing that low volume biopsy specimens could provide sufficient viable tissue to successfully engraft PDX models from patients with unresectable or metastatic disease.

MATERIALS AND METHODS

We maintain a prospective high volume gastrointestinal malignancy PDX program. With informed consent and institutional approval, biopsy specimens (surgical or image-guided) were obtained from patients with unresectable or metastatic tumors: pancreatic adenocarcinoma (PDAC), cholangiocarcinoma, gastric and gallbladder carcinoma. Biopsies were implanted into immunodeficient mice. Tumor growth was monitored, viable tumor was passed into subsequent generations, and histopathology was confirmed.

RESULTS

In this study, biopsy specimens from 29 patients were used for PDX engraftment. Successful PDX engraftment was variable with highest engraftment rates in gastric and gallbladder carcinoma specimens (100%) compared to engraftment rates of 33% and 29% in PDAC and cholangiocarcinoma respectively. PDX models created from metastasis biopsies compared to unresectable primary tumor tissue demonstrated higher engraftment rates (69% versus 15.4%, p = 0.001). PDX models demonstrated higher engraftment rates when biopsies were obtained during surgical operations (n = 15) compared to image-guided (n = 14) (73% versus 14%, p = 0.003). Patient age, pretreatment status, or ischemic time was not different between biopsy methods.

CONCLUSIONS

PDX models can be successfully created from clinical biopsy specimens in patients with metastatic or unresectable GI cancers. The use of clinical biopsy specimens for PDX engraftment can expand the repertoire of stage-specific PDX models for downstream basic/translational research.

Defining an intra-operative blunt mesenteric injury grading system and its use as a tool for surgical-decision making

BACKGROUND

The mesentery may be injured in trauma and few grading systems describe mesenteric injury severity. We aimed to develop and validate an intra-operative mesenteric injury grading system.

METHODS

A modified Delphi technique was used to generate an intraoperative grading system for blunt mesenteric injury called the mesenteric injury score (MIS). We performed a retrospective review (2010-2016) of patients >15 years old with blunt abdominal trauma. Patient demographics, injury severity score (ISS) and mechanism, clinical, operative, and outcome data were abstracted. The intraoperative grading system was used to describe patient outcomes including duration of stay and management approach. We compared the correlation of abdominal abbreviated injury score, Blunt Injury Prediction Score (BIPS) and the MIS with clinical outcomes using Spearman's rho.

RESULTS

There were fifty-one patients of which 86% were male. Injury mechanisms included motor vehicle accidents (n = 37, 73%), pedestrian vehicle accidents (n = 7, 13%), assaults (n = 4, 8%), falls (n = 2, 4%), and a single airplane crash (2%). Median [IQR] ISS was 16 [10-25] and GCS at hospital admission was 15 [15-15]. The median [IQR] international normalized ratio was 1.2 [1.1-1.5], lactate was 2.7 [1.7-4.9], and hemoglobin was 11.4 [8.6-12.2]. The distributions of MIS included Grade I (3, 5%), Grade II (10, 20%), Grade III (10, 20%), Grade IV, 5 (10%), and Grade V (23, 45%). Increasing mesenteric injury grade was associated with longer duration of stay, need for bowel resection, and damage control laparotomy.

CONCLUSIONS

We developed an intra-operative mesenteric injury grading system (MIS) and provided an initial retrospective validation using a series of patients with blunt abdominal trauma. The proposed MIS corresponded with both the AIS and the BIPS. Future study comparing cross sectional imaging and operative findings based on MIS criteria is needed.

Application of the AAST EGS Grade for Adhesive Small Bowel Obstruction to a Multi-national Patient Population

BACKGROUND

The American Association for the Surgery of Trauma (AAST) anatomic severity grading system for adhesive small bowel obstruction (ASBO) has demonstrated to be a valid tool in North American patient populations. Using a multi-national patient cohort, we retrospectively assessed the validity the AAST ASBO grading system and estimated disease severity in a global population in order to correlate with several key clinical outcomes.

METHODS

Multicenter retrospective review during 2012-2016 from four centers, Minnesota USA, Bologna Italy, Pietermaritzburg South Africa, and Bucharest Romania, was performed. Adult patients (age ≥ 18) with ASBO were identified. Baseline demographics, physiologic parameters, laboratory results, operative and imaging details, outcomes were collected. AAST ASBO grades were assigned by independent reviewers. Univariate and multivariable analyses with odds ratio (OR) and 95% confidence intervals (CIs) were performed.

RESULTS

There were 789 patients with a median [IQR] age of 58 [40-75] years; 47% were female. The AAST ASBO grades were I (n = 180, 23%), II (n = 443, 56%), III (n = 87, 11%), and IV (n = 79, 10%). Successful non-operative management was 58%. Conversion rate from laparoscopy to laparotomy was 33%. Overall mortality and complication and temporary abdominal closure rates were 2, 46, and 4.7%, respectively. On regression, independent predictors for mortality included grade III (OR 4.4 95%CI 1.1-7.3), grade IV (OR 7.4 95%CI 1.7-9.4), pneumonia (OR 5.6 95%CI 1.4-11.3), and failing non-operative management (OR 2.4 95%CI 1.3-6.7).

CONCLUSION

The AAST EGS grade can be assigned with ease at any surgical facility using operative or imaging findings. The AAST ASBO severity grading system has predictive validity for important clinical outcomes and allows for standardization across institutions, providers, and future research. Disease severity and outcomes varied between countries.

LEVEL OF EVIDENCE III

Study type Retrospective multi-institutional cohort study.

Pediatric Appendicitis Severity in KwaZulu-Natal, South Africa: A Retrospective Cohort Analysis

BACKGROUND

Acute appendicitis is a common pediatric surgical emergency; however, there are few grading systems to assign disease severity. The American Association for the Surgery of Trauma (AAST) recently developed a grading system for a variety of emergency surgical conditions, including appendicitis. The severity of acute appendicitis in younger patients in KwaZulu-Natal (South Africa) is unknown. We aimed to describe the disease severity in this patient population using the AAST grading system hypothesizing that the AAST grade would correlate with morbidity, management type, and duration of stay.

MATERIALS

Single institutional review of patients <18 years old with a final diagnosis of acute appendicitis during 2010-2016 in KwaZulu-Natal, South Africa, was performed. Demographics, physiologic and symptom data, procedural details, postoperative complications, and Clavien-Dindo classification were abstracted. AAST grades were generated based on intraoperative findings. Summary, univariate, and nominal logistic regression analyses were performed to compare AAST grade and outcomes.

RESULTS

A total of 401 patients were identified with median [IQR] age of 11 [5-13], 65% male. Appendectomy was performed in all patients; 2.4% laparoscopic, 37.6% limited incision, and 60% midline laparotomy. Complications occurred in 41.6%, most commonly unplanned relaparotomy (22.4%), surgical site infection (8.9%), pneumonia (7.2%), and acute renal failure (2.9%). Complication rate and median length of stay increased with greater AAST grade (all p < 0.001). AAST grade was independently associated with increased risk of complications.

CONCLUSION

Pediatric appendicitis is a morbid disease in a developing middle-income country. The AAST grading system is generalizable and accurately corresponds with management strategies as well as key clinical outcomes.

LEVEL OF EVIDENCE

Retrospective study, Level IV.

STUDY TYPE

Retrospective single institutional study.

Prothrombin Complex Concentrate Reversal of Coagulopathy in Emergency General Surgery Patients

BACKGROUND

Coagulopathy can delay or complicate surgical diseases that require emergent surgical treatment. Prothrombin complex concentrates (PCC) provide concentrated coagulation factors which may reverse coagulopathy more quickly than plasma (FFP) alone. We aimed to determine the time to operative intervention in coagulopathic emergency general surgery patients receiving either PCC or FFP. We hypothesize that PCC administration more rapidly normalizes coagulopathy and that the time to operation is diminished compared to FFP alone.

METHODS

Single institution retrospective review was performed for coagulopathic EGS patients during 2/1/2008 to 8/1/2016. Patients were divided into three groups (1) PCC alone (2) FFP alone and (3) PCC and FFP. The primary outcome was the duration from clinical decision to operate to the time of incision. Summary and univariate analyses were performed.

RESULTS

Coagulopathic EGS patients (n = 183) received the following blood products: PCC (n = 20, 11%), FFP alone (n = 119, 65%) and PCC/FFP (n = 44, 24%). The mean (± SD) patient age was 71 ± 13 years; 60% were male. The median (IQR) Charlson comorbidity index was similar in all three groups (PCC = 5(4-6), FFP = 5(4-7), PCC/FFP = 5(4-6), p = 0.33). The mean (± SD) dose of PCC administered was similar in the PCC/FFP group and the PCC alone group (2539 ± 1454 units vs. 3232 ± 1684, p = .09). The mean (±SD) time to incision in the PCC alone group was significantly lower than the FFP alone group (6.0 ± 3.6 vs. 8.8 ± 5.0 h, p = 0.01). The mean time to incision in the PCC + FFP group was also significantly lower than the FFP alone group (7.1 ± 3.6 vs. 8.8 ± 5.0, p = 0.03). The incidence of thromboembolic complications was similar in all three groups.

CONCLUSIONS

PCC, alone or in combination with FFP, reduced INR and time to surgery effectively and safely in coagulopathic EGS patients without an apparent increased risk of thromboembolic events, when compared to FFP use alone.

LEVEL OF EVIDENCE

IV single institutional retrospective review.

Appendicitis: Rural Patient Status is Associated with Increased Duration of Prehospital Symptoms and Worse Outcomes in High- and Low-Middle-Income Countries

INTRODUCTION

Appendicitis is a significant economic and healthcare burden in low-, middle-, and high-income countries. We aimed to determine whether urban and rural patient status would affect outcomes in appendicitis in a combined population regardless of country of economic status. We hypothesize that patients from rural areas and both high- and low-middle-income countries would have disproportionate outcomes and duration of symptoms compared to their urban counterparts.

METHODS

Adults (≥18 years) with appendicitis during 2010-2016 in South Africa and USA were reviewed using multi-institutional data. Baseline demographic, operative details, durations of stay, and complications (Clavien-Dindo index) were collected. AAST grades were assigned by two independent reviewers based on operative findings. Summary, univariate, and multivariable analyses of rural and urban patients in both countries were performed.

RESULTS

There were 2602 patients with a median interquartile range [IQR] of 26 [18-40] years; 45% were female. Initial management included McBurney incisions (n = 458, 18%), laparotomy (n = 915, 35%), laparoscopic appendectomy (n = 1185, 45%), and laparoscopy converted to laparotomy (n = 44, 2%). Comparing rural versus urban patient status, there were increased overall median [IQR] AAST grades (3 [1-5] vs. 2 [1-3], p = 0.001), prehospital duration of symptoms (2 [1-5] vs. 2 [1-3], p = 0.001), complications (44.3 vs. 23%, p = 0.001), and need for temporary abdominal closure (20.3 vs. 6.9%, p = 0.001).

CONCLUSION

Despite socioeconomic status and country of origin, patients from more rural environments demonstrate poorer outcomes notwithstanding significant differences in overall disease severity. The AAST grading system may serve a potential benchmark to recognize areas with disparate disease burdens. This information could be used for strategic improvements for surgeon placement and availability.

Transversus abdominis plane blocks with liposomal bupivacaine after open major hepatectomy is associated with reduced early patient-reported pain scores and opioid administration

BACKGROUND

Opioid overprescription can contribute to suboptimal patient outcomes. Surgeon-performed transversus abdominis plane blocks appear to be associated with pain reduction. We compared the analgesic efficacy of surgeon-performed transversus abdominis plane blocks for major hepatectomy with or without concurrent neuraxial analgesia.

METHODS

We performed a single-institution review, assessing surgeon-performed transversus abdominis plane blocks for major hepatectomy during 2013-2016. The primary outcome was patient-reported pain (11-point numeric pain-rating scale) and the secondary outcome was opioid consumption. Independent factors predictive of pain control were identified using logistic regression and reported as odds ratios with 95% confidence intervals.

RESULTS

A total of 232 patients with a mean (± SD) age of 56.5 (±13.9) years; 51.7% were female. Operative duration, incision type, and American Society of Anesthesiologists score were similar between groups. The 24-hour pain score was decreased substantially in patients who received a transversus abdominis plane block compared with those who did not (3 [2-4] versus 5 [4-6], P = .001) and this decrease in pain sscore persisted at 48 hours (2 [1-2] versus 4 [4-5], P = .001). In patients who received a transversus abdominis plane block, there were decreasess in consumption of oral morphine equivalents at 24 hours (322 [± 18] versus 183 [± 15], P = .0001) and 48 hours (100 [± 11] versus 33 [± 9.4], P = .03) compared with those without transversus abdominis plane block respectively.

CONCLUSION

In patients receiving a transversus abdominis plane block, early patient opioid consumption was decreased and utilization was predictive for improved pain control. Routine transversus abdominis plane block administration should be considered during major hepatectomy as a step toward curbing systematic reliance on opioids for pain management. A prospective study on the utility of transversus abdominis plane block in hepatectomy is warranted.

Validation of the AAST EGS grading system for perforated peptic ulcer disease

INTRODUCTION

Perforated peptic ulcer disease (PPUD) including both duodenl and gastric ulcers is a severe disease and outcomes are influenced by comorbidities and physiology. We validated the AAST EGS grading system at two diverse centers (Mayo Clinic, USA and Pietermaritzburg, South Africa).

METHODS

Dual-center review of historic data (2010-2016) of adults with PPUD was performed. Preoperative, procedural, and postoperative data were abstracted. ASA, Boey, PULP and AAST EGS grades were generated. Comparative, multivariable, and pairwise analyses were performed.

RESULTS

There were 306 patients, 42% female with a mean (±SD) age of 56 ±20 years. Overall, the patints were categorized into the following AAST EGS grades: I (30, 10%), II (38, 12%), III (104, 34%), IV (76, 2e%), V (58, 18.9%). Initial management included: midline laparotomy (51%, n=157), laparoscopy (18%, n=58), laparoscopy converted to laparotomy (1%, n=3), and endoscopy (30%, n=88). Duration of stay increased with AAST EGS grade. In United States cohort, factors predictive for 30-day mortality included AAST EGS grade and patient comorbidity status. The AAST EGS grade was comparable to other scoring systems (Boey, PULP, and ASA).

CONCLUSIONS

Differences exist between centers for management of PPUD and their outcomes; however, the AAST EGS grade can be utilized to stratify thedisease severity of the patient and this demonstrates initial construct validity in a United States but not in a South African population.

YAP Tyrosine Phosphorylation and Nuclear Localization in Cholangiocarcinoma Cells Are Regulated by LCK and Independent of LATS Activity

The Hippo pathway effector, Yes-associated protein (YAP), is a transcriptional coactivator implicated in cholangiocarcinoma (CCA) pathogenesis. YAP is known to be regulated by a serine/threonine kinase relay module (MST1/2-LATS1/2) culminating in phosphorylation of YAP at Serine 127 and cytoplasmic sequestration. However, YAP also undergoes tyrosine phosphorylation, and the role of tyrosine phosphorylation in YAP regulation remains unclear. Herein, YAP regulation by tyrosine phosphorylation was examined in human and mouse CCA cells, as well as patient-derived xenograft (PDX) models. YAP was phosphorylated on tyrosine 357 (Y357) in CCA cell lines and PDX models. SRC family kinase (SFK) inhibition with dasatinib resulted in loss of YAPY357 phosphorylation, promoted its translocation from the nucleus to the cytoplasm, and reduced YAP target gene expression, including cell lines expressing a LATS1/2-resistant YAP mutant in which all serine residues were mutated to alanine. Consistent with these observations, precluding YAPY357 phosphorylation by site-directed mutagenesis (YAPY357F) excluded YAP from the nucleus. Targeted siRNA experiments identified LCK as the SFK that most potently mediated YAPY357 phosphorylation. Likewise, inducible CRISPR/Cas9-targeted LCK deletion decreased YAPY357 phosphorylation and its nuclear localization. The importance of LCK in CCA biology was demonstrated by clinical observations suggesting LCK expression levels were associated with early tumor recurrence following resection of CCA. Finally, dasatinib displayed therapeutic efficacy in PDX models. Mol Cancer Res; 16(10); 1556-67. ©2018 AACR.

Fibroblast growth factor receptor inhibition induces loss of matrix MCL1 and necrosis in cholangiocarcinoma

BACKGROUND & AIMS

Myeloid cell leukemia 1 (MCL1), a prosurvival member of the BCL2 protein family, has a pivotal role in human cholangiocarcinoma (CCA) cell survival. We previously reported that fibroblast growth factor receptor (FGFR) signalling mediates MCL1-dependent survival of CCA cells in vitro and in vivo. However, the mode and mechanisms of cell death in this model were not delineated.

METHODS

Human CCA cell lines were treated with the pan-FGFR inhibitor LY2874455 and the mode of cell death examined by several complementary assays. Mitochondrial oxidative metabolism was examined using a XF24 extracellular flux analyser. The efficiency of FGFR inhibition in patient-derived xenografts (PDX) was also assessed.

RESULTS

CCA cells expressed two species of MCL1, a full-length form localised to the outer mitochondrial membrane, and an N terminus-truncated species compartmentalised within the mitochondrial matrix. The pan-FGFR inhibitor LY2874455 induced non-apoptotic cell death in the CCA cell lines associated with cellular depletion of both MCL1 species. The cell death was accompanied by failure of mitochondrial oxidative metabolism and was most consistent with necrosis. Enforced expression of N terminus-truncated MCL1 targeted to the mitochondrial matrix, but not full-length MCL1 targeted to the outer mitochondrial membrane, rescued cell death and mitochondrial function. LY2874455 treatment of PDX-bearing mice was associated with tumour cell loss of MCL1 and cell necrosis.

CONCLUSIONS

FGFR inhibition induces loss of matrix MCL1, resulting in cell necrosis. These observations support a heretofore unidentified, alternative MCL1 survival function, namely prevention of cell necrosis, and have implications for treatment of human CCA.

LAY SUMMARY

Herein, we report that therapeutic inhibition of a cell receptor expressed by bile duct cancer cells resulted in the loss of a critical survival protein termed MCL1. Cellular depletion of MCL1 resulted in the death of the cancer cells by a process characterised by cell rupture. Cell death by this process can stimulate the immune system and has implications for combination therapy using receptor inhibition with immunotherapy.

Bone Autograft Coupled with Locking Plates Repairs Symptomatic Rib Fracture Nonunions

Symptomatic rib nonunions are a rare complication after rib fractures. Methods used to address these nonunions range from pain management, rib resection, and rib fixation with plates and occasional autologous bone grafting. Given potential complications associated with rib resections such as pulmonary hernia, we hypothesized that plate fixation and autologous bone grafting would yield satisfactory long-term outcomes and a high union rate. Patients (aged ≥18 years) at a single institution with a symptomatic rib nonunion who underwent surgical rib stabilization of the nonunion coupled with bone autograft were evaluated (2010-2014). Pertinent clinical, operative, radiologic, and follow-up data were abstracted. Univariate analyses to assess the relationship of clinical outcomes were performed. Six patients underwent nonunion repair with autograft and plating. The mean time from injury to surgical repair of nonunion was 15 (±6.1) months. A median of 3 [1-3] ribs were repaired with surgery. Postoperative radiographic union was demonstrated on cross-sectional imaging at three months in four patients (57%) and in all patients at five months postoperatively. No patients developed postoperative pulmonary hernia during follow-up. All patients had a significant reduction in median patient-reported pain at follow-up. Surgical rib fixation and bone autograft can provide acceptable outcomes for patients with rib fracture nonunion. This method provides pain relief and promotes healing of the nonunion gap without pulmonary hernia development. Operative fixation and bone autograft should be considered as a viable technical alternative to resection alone for rib nonunion.

Bone Autograft Coupled with Locking Plates Repairs Symptomatic Rib Fracture Nonunions

Symptomatic rib nonunions are a rare complication after rib fractures. Methods used to address these nonunions range from pain management, rib resection, and rib fixation with plates and occasional autologous bone grafting. Given potential complications associated with rib resections such as pulmonary hernia, we hypothesized that plate fixation and autologous bone grafting would yield satisfactory long-term outcomes and a high union rate. Patients (aged ≥18 years) at a single institution with a symptomatic rib nonunion who underwent surgical rib stabilization of the nonunion coupled with bone autograft were evaluated (2010–2014). Pertinent clinical, operative, radiologic, and follow-up data were abstracted. Univariate analyses to assess the relationship of clinical outcomes were performed. Six patients underwent nonunion repair with autograft and plating. The mean time from injury to surgical repair of nonunion was 15 (66.1) months. A median of 3 [1–3] ribs were repaired with surgery. Postoperative radiographic union was demonstrated on cross-sectional imaging at three months in four patients (57%) and in all patients at five months postoperatively. No patients developed postoperative pulmonary hernia during follow-up. All patients had a significant reduction in median patient-reported pain at follow-up. Surgical rib fixation and bone autograft can provide acceptable outcomes for patients with rib fracture nonunion. This method provides pain relief and promotes healing of the nonunion gap without pulmonary hernia development. Operative fixation and bone autograft should be considered as a viable technical alternative to resection alone for rib nonunion.

Weekend woodsmen: Overview and comparison of injury patterns associated with power saw and axe utilization in the United States

INTRODUCTION

Power saw and axe injuries are associated with significant morbidity and are increasingly managed in the emergency department (ED). However, these injuries have not been summarily reported in the literature. We aim to evaluate and compare the common injury patterns seen with use of power saws and axes.

MATERIALS AND METHODS

Data from the National Electronic Injury Surveillance System- All Injury Program (NEISS-AIP) database was analyzed during 2006 to 2016. All patients with nonfatal injuries relating to the use of power saws or axes were included. Baseline demographics type and location of injuries were collected. Descriptive statistical analyses were performed using Chi Square or Fisher's exact test.

RESULTS

Information on (n = 18,250) patients was retrieved from the NEISS-AIP database. Injuries were caused by power saw n = 16,384 (89%) and axe n = 1866 (11%) use, and mostly involved males (95%). The most frequently encountered injury was laceration axe n = 1166 (62.5%); power saw n = 11,298 (68.9%). Approximately half of all injuries in both groups involved the fingers and hand. Most injuries occurred at home (65%) and were attributed to power saw use (89%).

CONCLUSIONS

Power saws and axes can cause significant injuries, the majority of which occurred at home and were primarily associated with power saw use. Lacerations and injuries to the finger and hand were prevalent in both study groups. Further research into power saw and axe injuries should place emphasis on preventative measures and personal protective equipment (PPE).

LEVEL OF EVIDENCE

IV Study type: Retrospective review.

Validation of the American Association for the Surgery of Trauma's emergency general surgery breast infection grading system

BACKGROUND

The American Association for the Surgery of Trauma (AAST) developed emergency general surgery (EGS) grading systems for multiple diseases to standardize classification of disease severity. The grading system for breast infections has not been validated. We aimed to validate the AAST breast infection grading system.

METHODS

Multi-institutional retrospective review of all adult patients with a breast infection diagnosis at Mayo Clinic Rochester 1/2015-10/2015 and Pietermaritzburg South African Hospital 1/2010-4/2016 was performed. AAST EGS grades were assigned by two independent reviewers. Inter-rater reliability was measured using the agreement statistic (kappa). Final AAST grade was correlated with patient and treatment factors using Pearson's correlation coefficient.

RESULTS

Two hundred twenty-five patients were identified: grade I (n = 152, 67.6%), II (n = 44, 19.6%), III (n = 25, 11.1%), IV (n = 0, 0.0%), and V (n = 4, 1.8%). At Mayo Clinic Rochester, AAST grades ranged from I-III. The kappa was 1.0, demonstrating 100% agreement between reviewers. Within the South African patients, grades included II, III, and V, with a kappa of 0.34, due to issues of the grading system application to this patient population. Treatment received correlated with AAST grade; less severe breast infections (grade I-II) received more oral antibiotics (correlation [-0.23, P = 0.0004]), however, higher AAST grades (III) received more intravenous antibiotics (correlation 0.29, P <0.0001).

CONCLUSIONS

The AAST EGS breast infection grading system demonstrates reliability and ease for disease classification, and correlates with required treatment, in patients presenting with low-to-moderate severity infections at an academic medical center; however, it needs further refinement before being applicable to patients with more severe disease presenting for treatment in low-/middle-income countries.

Definitive airway management after prehospital supraglottic rescue airway in pediatric trauma

INTRODUCTION

Supraglottic airway (SGA) use and outcomes in pediatric trauma are poorly understood. We compared outcomes between patients receiving prehospital SGA versus bag mask ventilation (BVM).

METHODS

We reviewed pediatric multisystem trauma patients (2005-2016), comparing SGA and BVM. Primary outcome was adequacy of oxygenation and ventilation. Additional measures included tracheostomy, mortality and abbreviated injury scores (AIS).

RESULTS

Ninety patients were included (SGA, n=17 and BVM, n=73). SGA patients displayed increased median head AIS (5 [4-5] vs 2 [0-4], p=0.001) and facial AIS (1 [0-2] vs 0 [0-0], p=0.03). SGA indications were multiple failed intubation attempts (n=12) and multiple failed attempts with poor visualization (n=5). Median intubation attempts were 2 [1-3] whereas BVM patients had none. Compared to BVM, SGA patients demonstrated inadequate oxygenation/ventilation (75% vs 41%), increased tracheostomy rates (31% vs 8.1%), and increased 24-h (38% vs 10.8%) and overall mortality (75% vs 14%) (all p<0.05).

CONCLUSIONS

Escalating intubation attempts and severe facial AIS were associated with tracheostomy. Inadequacy of oxygenation/ventilation was more frequent in SGA compared to BVM patients. SGA patients demonstrate poor clinical outcomes; however, SGAs may be necessary in increased craniofacial injury patterns. These factors may be incorporated into a management algorithm to improve definitive airway management after SGA.

Measuring Anatomic Severity in Pediatric Appendicitis: Validation of the American Association for the Surgery of Trauma Appendicitis Severity Grade

OBJECTIVE

To assess whether the American Association for the Surgery of Trauma (AAST) grading system accurately corresponds with appendicitis outcomes in a US pediatric population.

STUDY DESIGN

This single-institution retrospective review included patients <18 years of age (n = 331) who underwent appendectomy for acute appendicitis from 2008 to 2012. Demographic, clinical, procedural, and follow-up data (primary outcome was measured as Clavien-Dindo grade of complication severity) were abstracted. AAST grades were generated based on intraoperative findings. Summary, univariate, and multivariable regression analyses were performed to compare AAST grade and outcomes.

RESULTS

Overall, 331 patients (46% female) were identified with a median age of 12 (IQR, 8-15) years. Appendectomy was laparoscopic in 90% and open in 10%. AAST grades included: Normal (n = 13, 4%), I (n = 152, 46%), II (n = 90, 27%), III (n = 43, 13%), IV (n = 24 7.3%), and V (n = 9 2.7%). Increased AAST grade was associated with increased Clavien-Dindo severity, P =.001. The overall complication rate was 13.6% and was comprised by superficial surgical site infection (n = 13, 3.9%), organ space infection (n = 15, 4.5%), and readmission (n = 17, 5.1%). Median duration of stay increased with AAST grade (P < .0001). Nominal logistic regression identified the following as predictors of any complication (P < .05): AAST grade and febrile temperature at admission.

CONCLUSIONS

The AAST appendicitis grading system is valid in a single-institution pediatric population. Increasing AAST grade incrementally corresponds with patient outcomes including increased risk of complications and severity of complications. Determination of the generalizability of this grading system is required.

Platelet-derived growth factor regulates YAP transcriptional activity via Src family kinase dependent tyrosine phosphorylation

The Hippo pathway effector YAP is implicated in the pathogenesis of cholangiocarcinoma (CCA). The Hippo pathway relies on signaling cross talk for its regulation. Given the importance of platelet derived growth factor receptor (PDGFR) signaling in CCA biology, our aim was to examine potential YAP regulation by PDGFR. We employed human and mouse CCA specimens and cell lines for these studies. Initially, we confirmed upregulation of PDGFRβ and PDGFR ligands in human and mouse CCA specimens and cell lines. YAP, a transcriptional co-activator, was localized to the nucleus in human CCA specimens and a cell line, as well as patient derived xenografts (PDX). PDGFR pharmacologic inhibition led to a redistribution of YAP from the nucleus to cytosol and downregulation of YAP target genes in a human CCA cell line. siRNA silencing of PDGFR-β similarly downregulated YAP target genes. YAP activation (nuclear localization and target gene expression) was regulated by Src family kinases (SFKs) downstream of PDGFR. SFK activity resulted in phosphorylation of YAP on tyrosine³⁵⁷ (YAP^Y357 ). The importance of YAP^Y357 phosphorylation in regulating YAP activation was confirmed utilizing the SB-1 cell line, a mouse cell line expressing YAP S127A precluding canonical serine phosphorylation. PDGFR inhibition decreased cellular abundance of the survival protein Mcl-1, a known YAP target gene, and accordingly increased cell death in CCA cells in vitro and in vivo. These preclinical data demonstrate that a PDGFR-SFK cascade regulates YAP activation via tyrosine phosphorylation in CCA. Inhibiting this cascade may provide a viable therapeutic strategy for this human malignancy.

Needle Decompression of Tension Pneumothorax with Colorimetric Capnography

BACKGROUND

The success of needle decompression for tension pneumothorax is variable, and there are no objective measures assessing effective decompression. Colorimetric capnography, which detects carbon dioxide present within the pleural space, may serve as a simple test to assess effective needle decompression.

METHODS

Three swine underwent traumatically induced tension pneumothorax (standard of care, n = 15; standard of care with needle capnography, n = 15). Needle thoracostomy was performed with an 8-cm angiocatheter. Similarly, decompression was performed with the addition of colorimetric capnography. Subjective operator assessment of decompression was recorded and compared with true decompression, using thoracoscopic visualization for both techniques. Areas under receiver operating curves were calculated and pairwise comparison was performed to assess statistical significance (P < .05).

RESULTS

The detection of decompression by needle colorimetric capnography was found to be 100% accurate (15 of 15 attempts), when compared with thoracoscopic assessment (true decompression). Furthermore, it accurately detected the lack of tension pneumothorax, that is, the absence of any pathologic/space-occupying lesion, in 100% of cases (10 of 10 attempts). Standard of care needle decompression was detected by operators in 9 of 15 attempts (60%) and was detected in 3 of 10 attempts when tension pneumothorax was not present (30%). True decompression, under direct visualization with thoracoscopy, occurred 15 of 15 times (100%) with capnography, and 12 of 15 times (80%) without capnography. Areas under receiver operating curves were 0.65 for standard of care and 1.0 for needle capnography (P = .002).

CONCLUSIONS

Needle decompression with colorimetric capnography provides a rapid, effective, and highly accurate method for eliminating operator bias for tension pneumothorax decompression. This may be useful for the treatment of this life-threatening condition.

Visually guided tube thoracostomy insertion comparison to standard of care in a large animal model

INTRODUCTION

Tube thoracostomy (TT) is a lifesaving procedure for a variety of thoracic pathologies. The most commonly utilized method for placement involves open dissection and blind insertion. Image guided placement is commonly utilized but is limited by an inability to see distal placement location. Unfortunately, TT is not without complications. We aim to demonstrate the feasibility of a disposable device to allow for visually directed TT placement compared to the standard of care in a large animal model.

METHODS

Three swine were sequentially orotracheally intubated and anesthetized. TT was conducted utilizing a novel visualization device, tube thoracostomy visual trocar (TTVT) and standard of care (open technique). Position of the TT in the chest cavity were recorded using direct thoracoscopic inspection and radiographic imaging with the operator blinded to results. Complications were evaluated using a validated complication grading system. Standard descriptive statistical analyses were performed.

RESULTS

Thirty TT were placed, 15 using TTVT technique, 15 using standard of care open technique. All of the TT placed using TTVT were without complication and in optimal position. Conversely, 27% of TT placed using standard of care open technique resulted in complications. Necropsy revealed no injury to intrathoracic organs.

CONCLUSION

Visual directed TT placement using TTVT is feasible and non-inferior to the standard of care in a large animal model. This improvement in instrumentation has the potential to greatly improve the safety of TT. Further study in humans is required.

LEVEL OF EVIDENCE

Therapeutic Level II.

Injury patterns and outcomes of ice-fishing in the United States

INTRODUCTION

Fishing is a common pastime. In the developed world, it is commonly performed as a recreational activity. We aim to determine injury patterns and outcomes among patients injured while ice fishing.

METHODS

Data on initial emergency department visits from the National Electronic Injury Surveillance System-All Injury Program (NEISS-AIP) from 2009-2014 were analyzed. All patients with fishing related injuries were included. Primary endpoint was rate of admission or transfer. Secondary endpoints were defined a priori anatomical injury categories and patients were assigned into groups. Descriptive and power analysis was performed between patients with ice-fishing and traditional fishing related injuries.

RESULTS

We identified 8220 patients who sustained fishing related injuries, of which n=85 (1%) involved ice fishing. Ice fishing injuries occurred primarily in males (88%) with a mean age of 39.4years ±17.5 (std dev). The most common injuries related to ice fishing were: orthopedic/musculoskeletal (46%), minor trauma (37%), and major trauma (6%). Hot thermal injuries (burns) were the fourth most common type of ice-fishing injury (5%) but rarely occurred in warmer fishing months (<1%, P=.004). Cold thermal injuries (1%) and hypothermia (0%) were rare among ice-fishing injuries and immersion/drowning occurred in 5% of cases. The rate of admission/transfer was significantly greater in ice-fishing (11%) than the traditional fishing patients 3%, (P<.001), power was 90%.

CONCLUSION

Ice fishing is associated with more severe injury patterns and more thermal injuries and immersion injuries than traditional fishing. Providers and participants should be aware of the potential risks and benefits and counseled appropriately.

Characterization of RO4583298 as a novel potent, dual antagonist with in vivo activity at tachykinin NK₁ and NK₃ receptors

BACKGROUND AND PURPOSE

Clinical results of osanetant and talnetant (selective-NK₃ antagonists) indicate that blocking the NK₃ receptor could be beneficial for the treatment of schizophrenia. The objective of this study was to characterize the in vitro and in vivo properties of a novel dual NK₁/NK₃ antagonist, RO4583298 (2-phenyl-N-(pyridin-3-yl)-N-methylisobutyramide derivative).

EXPERIMENTAL APPROACH

RO4583298 in vitro pharmacology was investigated using radioligand binding ([³H]-SP, [³H]-osanetant, [³H]-senktide), [³H]-inositol-phosphate accumulation Schild analysis (SP- or [MePhe⁷]-NKB-induced) and electrophysiological studies in guinea-pig substantia nigra pars compacta (SNpc). The in vivo activity of RO4583298 was assessed using reversal of GR73632-induced foot tapping in gerbils (GFT; NK₁) and senktide-induced tail whips in mice (MTW; NK₃).

KEY RESULTS

RO4583298 has a high-affinity for NK₁ (human and gerbil) and NK₃ (human, cynomolgus monkey, gerbil and guinea-pig) receptors and behaves as a pseudo-irreversible antagonist. Unusually it binds with high-affinity to mouse and rat NK₃, yet with a partial non-competitive mode of antagonism. In guinea-pig SNpc, RO4583298 inhibited the senktide-induced potentiation of spontaneous activity of dopaminergic neurones with an apparent non-competitive mechanism of action. RO4583298 (p.o.) robustly blocked the GFT response, and inhibited the MTW.

CONCLUSIONS AND IMPLICATIONS

RO4583298 is a high-affinity, non-competitive, long-acting in vivo NK₁/NK₃ antagonist; hence providing a useful in vitro and in vivo pharmacological tool to investigate the roles of NK₁ and NK₃ receptors in psychiatric disorders.