Telehealth Follow-Up After Inguinal Hernia Repair in Veterans.

INTRODUCTION: Telehealth has been increasingly utilized with a renewed interest by surgical specialties given the COIVD-19 pandemic. Limited data exists evaluating the safety of routine postoperative telehealth follow-up in patients undergoing inguinal hernia repair, especially those who present urgent/emergently. Our study sought to evaluate the safety and efficacy of postoperative telehealth follow-up in veterans undergoing inguinal hernia repair. METHODS: Retrospective review of all Veterans who underwent inguinal hernia repair at a tertiary Veterans Affairs Medical Center over a 2-year period (9/2019-9/2021). Outcome measures included postoperative complications, emergency department (ED) utilization, 30-day readmission, and missed adverse events (ED utilization or readmission occurring after routine postoperative follow-up). Patients undergoing additional procedure(s) requiring intraoperative drains and/or nonabsorbable sutures were excluded. RESULTS: Of 338 patients who underwent qualifying procedures, 156 (50.6%) were followed-up by telehealth and 152 (49.4%) followed-up in-person. There were no differences in age, sex, BMI, race, urgency, laterality nor admission status. Patients with higher American Society of Anesthesiologists (ASA) classification [ASA class III 92 (60.5%) versus class II 48 (31.6%), P = 0.019] and open repair [93 (61.2%) versus 67 (42.9%), P = 0.003] were more likely to follow-up in-person. There was no difference in complications, [telehealth 13 (8.3%) versus 20 (13.2%), P = 0.17], ED visits, [telehealth 15 (10%) versus 18 (12%), P = 0.53], 30-day readmission [telehealth 3 (2%) versus 0 (0%), P = 0.09], nor missed adverse events [telehealth 6 (33.3%) versus 5 (27.8%), P = 0.72]. CONCLUSIONS: There were no differences in postoperative complications, ED utilization, 30-day readmission, or missed adverse events for those who followed-up in person versus telehealth after elective or urgent/emergent inguinal hernia repair. Veterans with a higher ASA class and who underwent open repair were more likely to be seen in person. Telehealth follow-up after inguinal hernia repair is safe and effective.

Telehealth follow-up after cholecystectomy is safe in veterans.

BACKGROUND: The COVID-19 pandemic has brought many challenges including barriers to delivering high-quality surgical care and follow-up while minimizing the risk of infection. Telehealth has been increasingly utilized for post-operative visits, yet little data exists to guide surgeons in its use. We sought to determine safety and efficacy of telehealth follow-up in patients undergoing cholecystectomy during the global pandemic at a VA Medical Center (VAMC). METHODS: This was a retrospective review of patients undergoing cholecystectomy at a level 1A VAMC over a 2-year period from August 2019 to August 2021. Baseline demographics, post-operative complications, readmissions, emergency department (ED) visits and need for additional procedures were reviewed. Patients who experienced a complication prior to discharge, underwent a concomitant procedure, had non-absorbable skin closure, had new diagnosis of malignancy or were discharged home with drain(s) were ineligible for telehealth follow-up and excluded. RESULTS: Over the study period, 179 patients underwent cholecystectomy; 30 (17%) were excluded as above. 20 (13%) missed their follow-up, 52 (35%) were seen via telehealth and 77 (52%) followed-up in person. There was no difference between the two groups regarding baseline demographics or intra-operative variables. There was no significant difference in post-operative complications [4 (8%) vs 6 (8%), p > 0.99], ED utilization [5 (10%) vs 7 (9%), p = 0.78], 30-day readmission [3 (6%) vs 6 (8%), p = 0.74] or need for additional procedures [2 (4%) vs 4 (5%), p = 0.41] between telehealth and in-person follow-up. CONCLUSION: Telehealth follow-up after cholecystectomy is safe and effective in Veterans. There were no differences in outcomes between patients that followed up in-person vs those that were seen via phone or video. Routine telehealth follow-up after uncomplicated cholecystectomy should be considered for all patients.

A dedicated feeding tube clinic reduces emergency department utilization for gastrostomy tube complications.

INTRODUCTION: Enteral access is required for a variety of reasons from neuromuscular disorders to dysphagia. Gastrostomy tubes (GTs) can be placed endoscopically, surgically, or radiographically and complications include infection, bleeding, leakage and unintentional removal. Routine post-procedural follow-up is limited by inconsistent guidelines and management by different specialty teams. We established a dedicated GT clinic to provide continuity of care and prophylactic GT exchange. We hypothesized that patients followed in the GT clinic would have reduced Emergency Department (ED) utilization. METHODS: A retrospective review of patients who underwent GT placement from January 2010 to January 2020 was conducted. Baseline demographics, indications for GT placement, number and reason for ED visits and utilization of a multidisciplinary GT clinic were studied. RESULTS: A total of 97 patients were included. The most common indication for placement was dysphagia (88, 91%) and the most common primary diagnosis was head and neck malignancy (51, 51%). The GT clinic is a multidisciplinary clinic staffed by surgeons and residents, dieticians, and wound care specialists and cared for 16 patients in this study. Three patients (19%) in the GT clinic group required ED visits compared to 44 (54%) in the standard of care (SOC) group (p < 0.05). There was an average of 0.9 ED visits per patient (range 0-7) in the GT clinic group vs 1.6 ED visits per patient (range 0-20) in the SOC group (p = 0.34). Feeding tubes were prophylactically exchanged an average of 7 times per patient in the GT clinic group vs 3 times per patient in the SOC group (p < 0.05). CONCLUSION: A multidisciplinary clinic dedicated to GT care limits ED visits for associated complications by more than 50%. Follow-up in a dedicated clinic with prophylactic tube exchange decreases ED visits and should be considered at facilities that care for patients with GTs.

Hepatic thermal injury promotes colorectal cancer engraftment in C57/black 6 mice.

Treatment options for liver metastases (primarily colorectal cancer) are limited by high recurrence rates and persistent tumor progression. Surgical approaches to management of these metastases typically use heat energy including electrocautery, argon beam coagulation, thermal ablation of surgical margins for hemostasis, and preemptive thermal ablation to prevent bleeding or to effect tumor destruction. Based on high rates of local recurrence, these studies assess whether local effects of hepatic thermal injury (HTI) might contribute to poor outcomes by promoting a hepatic microenvironment favorable for tumor engraftment or progression due to induction of procancer cytokines and deleterious immune infiltrates at the site of thermal injury. To test this hypothesis, an immunocompetent mouse model was developed wherein HTI was combined with concomitant intrasplenic injection of cells from a well-characterized MC38 colon carcinoma cell line. In this model, HTI resulted in a significant increase in engraftment and progression of MC38 tumors at the site of thermal injury. Furthermore, there were local increases in expression of messenger ribonucleic acid (mRNA) for hypoxia-inducible factor-1α (HIF1α), arginase-1, and vascular endothelial growth factor α and activation changes in recruited macrophages at the HTI site but not in untreated liver tissue. Inhibition of HIF1α following HTI significantly reduced discreet hepatic tumor development (P = 0.03). Taken together, these findings demonstrate that HTI creates a favorable local environment that is associated with protumorigenic activation of macrophages and implantation of circulating tumors. Discrete targeting of HIF1α signaling or inhibiting macrophages offers potential strategies for improving the outcome of surgical management of hepatic metastases where HTI is used.

Monopolar stray energy in robotic surgery.

INTRODUCTION: Stray energy transfer from monopolar radiofrequency energy during laparoscopy can be potentially catastrophic. Robotic surgery is increasing in popularity; however, the risk of stray energy transfer during robotic surgery is unknown. The purpose of this study was to (1) quantify stray energy transfer using robotic instrumentation, (2) determine strategies to minimize the transfer of energy, and (3) compare robotic stray energy transfer to laparoscopy. METHODS: In a laparoscopic trainer, a monopolar instrument (L-hook) was activated with DaVinci Si (Intuitive, Sunnyvale, CA) robotic instruments. A camera and assistant grasper were inserted to mimic a minimally invasive cholecystectomy. During activation of the L-hook, the non-electric tips of the camera and grasper were placed adjacent to simulated tissue (saline-soaked sponge). The primary outcome was change in temperature from baseline (°C) measured nearest the tip of the non-electric instrument. RESULTS: Simulated tissue nearest the robotic grasper increased an average of 18.3 ± 5.8 °C; p < 0.001 from baseline. Tissue nearest the robotic camera tip increased (9.0 ± 2.1 °C; p < 0.001). Decreasing the power from 30 to 15 W (18.3 ± 5.8 vs. 2.6 ± 2.7 °C, p < 0.001) or using low-voltage cut mode (18.3 ± 5.8 vs. 3.1 ± 2.1 °C, p < 0.001) reduced stray energy transfer to the robotic grasper. Desiccating tissue, in contrast to open air activation, also significantly reduced stray energy transfer for the grasper (18.3 ± 5.8 vs. 0.15 ± 0.21 °C, p < 0.001) and camera (9.0 ± 2.1 vs. 0.24 ± 0.34 °C, p < 0.001). CONCLUSIONS: Stray energy transfer occurs during robotic surgery. The assistant grasper carries the highest risk for thermal injury. Similar to laparoscopy, stray energy transfer can be reduced by lowering the power setting, utilizing a low-voltage cut mode instead of coagulation mode and avoiding open air activation. These practical findings can aid surgeons performing robotic surgery to reduce injuries from stray energy.

Stray energy transfer in single-incision robotic surgery.

INTRODUCTION: Stray energy transfer from surgical monopolar radiofrequency energy instruments can cause unintended thermal injuries during laparoscopic surgery. Single-incision laparoscopic surgery transfers more stray energy than traditional laparoscopic surgery. There is paucity of published data concerning stray energy during single-incision robotic surgery. The purpose of this study was to quantify stray energy transfer during traditional, multiport robotic surgery (TRS) compared to single-incision robotic surgery (SIRS). METHODS: An in vivo porcine model was used to simulate a multiport or single-incision robotic cholecystectomy (DaVinci Si, Intuitive Surgical, Sunnyvale, CA). A 5 s, open air activation of the monopolar scissors was done on 30 W and 60 W coag mode (ForceTriad, Covidien-Medtronic, Boulder, CO) and Swift Coag effect 3, max power 180 W (VIO 300D, ERBE USA, Marietta, GA). Temperature of the tissue (°C) adjacent to the tip of the assistant grasper or the camera was measured with a thermal camera (E95, FLIR Systems, Wilsonville, OR) to quantify stray energy transfer. RESULTS: Stray energy transfer was greater in the SIRS setup compared to TRS setup at the assistant grasper (11.6 ± 3.3 °C vs. 8.4 ± 1.6 °C, p = 0.013). Reducing power from 60 to 30 W significantly reduced stray energy transfer in SIRS (15.3 ± 3.4 °C vs. 11.6 ± 3.3 °C, p = 0.023), but not significantly for TRS (9.4 ± 2.5 °C vs. 8.4 ± 1.6 °C, p = 0.278). The use of a constant voltage regulating generator also minimized stray energy transfer for both SIRS (0.7 ± 0.4 °C, p < 0.001) and TRS (0.7 ± 0.4 °C, p < 0.001). CONCLUSIONS: More stray energy transfer occurs during single-incision robotic surgery than multiport robotic surgery. Utilizing a constant voltage regulating generator minimized stray energy transfer for both setups. These data can be used to guide robotic surgeons in their use of safe, surgical energy.

Carbon dioxide can eliminate operating room fires from alcohol-based surgical skin preps.

INTRODUCTION: Surgical fires are a rare event that still occur at a significant rate and can result in severe injury and death. Surgical fires are fueled by vapor from alcohol-based skin preparations in the presence of increased oxygen concentration and a spark from an energy device. Carbon dioxide (CO2) is used to extinguish electrical fires, and we sought to evaluate its effect on fire creation in the operating room. We hypothesize that CO2 delivered by the energy device will decrease the frequency of surgical fires fueled by alcohol-based skin preparations. METHODS: An ex vivo model with 15 × 15 cm section of clipped, porcine skin was used. A commercially available electrosurgical pencil with a smoke evacuation tip was connected to a laparoscopic CO2 insufflation system. The electrosurgical pencil was activated for 2 s at 30 watts coagulation mode immediately after application of alcohol-based surgical skin preparations: 70% isopropyl alcohol with 2% chlorhexidine gluconate (CHG-IPA) or 74% isopropyl alcohol with 0.7% iodine povacrylex (Iodine-IPA). CO2 was infused via the smoke evacuation pencil at flow rates from 0 to 8 L/min. The presence of a flame was determined visually and confirmed with a thermal camera (FLIR Systems, Boston, MA). RESULTS: Carbon dioxide eliminated fire formation at a flow rate of 1 L/min with CHG-IPA skin prep (0% vs. 60% with no CO2, p < 0.0001). Carbon dioxide reduced fire formation at 1 L/min (25% vs. 47% with no CO2, p = 0.1) with Iodine-IPA skin prep and fires were eliminated at 2 L/min of flow with Iodine-IPA skin prep (p < 0.0001). CONCLUSION: Carbon dioxide can eliminate surgical fires caused by energy devices in the presence of alcohol-based skin preps. Future studies should determine the optimal technique and flow rate of carbon dioxide in these settings.

Hepatic Ablation Promotes Colon Cancer Metastases in an Immunocompetent Murine Model.

OBJECTIVE: To determine the impact of radiofrequency (RF) and microwave (MW) energy compared to direct cautery on metatstatic colon cancer growth. BACKGROUND: Hepatic ablation with MW and RF energy creates a temperature gradient around a target site with temperatures known to create tissue injury and cell death. In contrast, direct heat application (cautery) vaporizes tissue with a higher site temperature but reduced heat gradient on surrounding tissue. We hypothesize that different energy devices create variable zones of sublethal injury that may promote tumor recurrence. To test this hypothesis we applied MW, RF, and cautery to normal murine liver with a concomitant metastatic colon cancer challenge. METHODS: C57/Bl6 mice received hepatic thermal injury with MW, RF, or cautery to create a superficial 3-mm lesion immediately after intrasplenic injection of 50K MC38 colon cancer cells. Thermal imaging recorded tissue temperature during ablation and for 10 seconds after energy cessation. Hepatic tumor location and volume was determined at day 7. RESULTS: Cautery demonstrated the highest maximum tissue temperatures (129°C) with more rapid return to baseline compared to MW or RF energy. All mice had metastasis at the ablation site. Mean tumor volume was significantly greater in the MW (95.3 mm; P = 0.007) and RF (55.7 mm; P = 0.015) than cautery (7.13 mm). There was no difference in volume between MW and RF energy (P = 0.2). CONCLUSIONS: Hepatic thermal ablation promotes colon cancer metastasis at the injury site. MV and RF energy result in greater metastatic volume than cautery. These data suggest that the method of energy delivery promotes local metastasis.

Wearable Technology-A Pilot Study to Define "Normal" Postoperative Recovery Trajectories.

BACKGROUND: Emerging wearable technology has the potential to quantify both preoperative and postoperative patient activity. The purpose of this study was to characterize postoperative recovery trajectories for 1 mo after common surgical procedures. MATERIALS AND METHODS: Patients included were scheduled for common elective operations. A wearable activity device was worn for at least 3 d preoperatively and 28 d postoperatively. Postoperative steps per day were compared with preoperative baseline steps, with recovery trajectories reported as a percentage of patients' baseline values. Recovery trajectories were compared between groups based on admission type and operation type. RESULTS: Two hundred ten patients were enrolled, and 143 patients (68%) completed follow-up. Patients took a median 5342 steps per day preoperatively and had significantly decreased steps on the first postoperative day, including those undergoing inguinal hernia repair (22% of baseline steps, P < 0.001). Four weeks postoperatively, steps per day had not returned to baseline in patients undergoing minimally invasive abdominal (88% of baseline, P = 0.035), open abdominal (64% of baseline, P = 0.002), and thoracic (32% of baseline, P = 0.002) operations. All groups of patients showed a rapid recovery of steps during the first postoperative week, followed by a slower return to baseline. Recovery trajectories differed based on both admission type and operation type. CONCLUSIONS: Wearable activity monitors provide useful technology for quantification of postoperative activity recovery trajectories of steps per day in comparison to preoperative activity levels, with internal validity differentiating recovery trajectories grouping by broad categorization of operation type and by admission type. Activity recovery is a patient-centered outcome that can be used for counseling as well as for intervening to improve activity levels after surgery.

Hand-to-hand coupling and strategies to minimize unintentional energy transfer during laparoscopic surgery.

BACKGROUND: Energy-based devices are used in nearly every laparoscopic operation. Radiofrequency energy can transfer to nearby instruments via antenna and capacitive coupling without direct contact. Previous studies have described inadvertent energy transfer through bundled cords and nonelectrically active wires. The purpose of this study was to describe a new mechanism of stray energy transfer from the monopolar instrument through the operating surgeon to the laparoscopic telescope and propose practical measures to decrease the risk of injury. METHODS: Radiofrequency energy was delivered to a laparoscopic L-hook (monopolar "bovie"), an advanced bipolar device, and an ultrasonic device in a laparoscopic simulator. The tip of a 10-mm telescope was placed adjacent but not touching bovine liver in a standard four-port laparoscopic cholecystectomy setup. Temperature increase was measured as tissue temperature from baseline nearest the tip of the telescope which was never in contact with the energy-based device after a 5-s open-air activation. RESULTS: The monopolar L-hook increased tissue temperature adjacent to the camera/telescope tip by 47 ± 8°C from baseline (P < 0.001). By having an assistant surgeon hold the camera/telescope (rather than one surgeon holding both the active electrode and the camera/telescope), temperature change was reduced to 26 ± 7°C (P < 0.001). Alternative energy devices significantly reduced temperature change in comparison to the monopolar instrument (47 ± 8°C) for both the advanced bipolar (1.2 ± 0.5°C; P < 0.001) and ultrasonic (0.6 ± 0.3°C; P < 0.001) devices. CONCLUSIONS: Stray energy transfers from the monopolar "bovie" instrument through the operating surgeon to standard electrically inactive laparoscopic instruments. Hand-to-hand coupling describes a new form of capacitive coupling where the surgeon's body acts as an electrical conductor to transmit energy. Strategies to reduce stray energy transfer include avoiding the same surgeon holding the active electrode and laparoscopic camera or using alternative energy devices.

Goal-directed Hemostatic Resuscitation of Trauma-induced Coagulopathy: A Pragmatic Randomized Clinical Trial Comparing a Viscoelastic Assay to Conventional Coagulation Assays.

BACKGROUND: Massive transfusion protocols (MTPs) have become standard of care in the management of bleeding injured patients, yet strategies to guide them vary widely. We conducted a pragmatic, randomized clinical trial (RCT) to test the hypothesis that an MTP goal directed by the viscoelastic assay thrombelastography (TEG) improves survival compared with an MTP guided by conventional coagulation assays (CCA). METHODS: This RCT enrolled injured patients from an academic level-1 trauma center meeting criteria for MTP activation. Upon MTP activation, patients were randomized to be managed either by an MTP goal directed by TEG or by CCA (ie, international normalized ratio, fibrinogen, platelet count). Primary outcome was 28-day survival. RESULTS: One hundred eleven patients were included in an intent-to-treat analysis (TEG = 56, CCA = 55). Survival in the TEG group was significantly higher than the CCA group (log-rank P = 0.032, Wilcoxon P = 0.027); 20 deaths in the CCA group (36.4%) compared with 11 in the TEG group (19.6%) (P = 0.049). Most deaths occurred within the first 6 hours from arrival (21.8% CCA group vs 7.1% TEG group) (P = 0.032). CCA patients required similar number of red blood cell units as the TEG patients [CCA: 5.0 (2-11), TEG: 4.5 (2-8)] (P = 0.317), but more plasma units [CCA: 2.0 (0-4), TEG: 0.0 (0-3)] (P = 0.022), and more platelets units [CCA: 0.0 (0-1), TEG: 0.0 (0-0)] (P = 0.041) in the first 2 hours of resuscitation. CONCLUSIONS: Utilization of a goal-directed, TEG-guided MTP to resuscitate severely injured patients improves survival compared with an MTP guided by CCA and utilizes less plasma and platelet transfusions during the early phase of resuscitation.

Intercellular adhesion molecule-1 mediates murine colon adenocarcinoma invasion.

BACKGROUND: Intercellular adhesion molecule-1 (ICAM-1) modulates cell-cell adhesion and is a receptor for cognate ligands on leukocytes. Upregulation of ICAM-1 has been demonstrated in malignant transformation of adenomas and is associated with poor prognosis for many malignancies. ICAM-1 is upregulated on the invasive front of pancreatic metastases and melanomas. These data suggest that the upregulated ICAM-1 expression promotes malignant progression. We hypothesize that the downregulation of ICAM-1 will mitigate tumor progression. METHODS: Mouse colon adenocarcinoma cells (MC38) were evaluated for the expression of ICAM-1 using Western immunoblot analysis. Short hairpin RNA (shRNA) transduction was used to downregulate ICAM-1. Tumor invasion determined via a modified Boyden chamber was used as a surrogate of tumor progression examining MC38 cells, MC38 ICAM-1 knockdowns, and MC38 transduced with vehicle control. The cells were cultured in full media for 24 h and serum-starved for 24 h. A total of 5 × 10(4) cells were plated and allowed to migrate for 24 h using full media with 10% fetal bovine serum as a chemoattractant. Inserts were fixed and stained with crystal violet. Blinded investigators counted the cells using a stereomicroscope. Statistical analysis was performed by analysis of variance with Fischer protected least significant difference and a P value of <0.05 was considered statistically significant. RESULTS: ICAM-1 was constitutively expressed on MC38 cells. Transduction with anti-ICAM-1 shRNA vector downregulated ICAM-1 protein expression by 30% according to the Western blot analysis (P < 0.03) and decreased ICAM-1 messenger RNA expression by 70% according to the reverse transcription-polymerase chain reaction. shRNA knockdown cells had a significant reduction in invasion >45% (P < 0.03). There were no significant differences between the invasion rates of MC38 and MC38 vehicle controls. CONCLUSIONS: Downregulation of ICAM-1 mitigates MC38 invasion. These data suggest that targeted downregulation of tumor ICAM-1 is a potential therapeutic target.

Telehealth for general surgery postoperative care.

BACKGROUND: Telehealth utilization rapidly increased following the pandemic. However, it is not widely used in the Veteran surgical population. We sought to evaluate postoperative telehealth in patients undergoing general surgery. METHODS: Retrospective review of Veterans undergoing general surgery at a level 1A VA Medical Center from June 2019 to September 2021. Exclusions were concomitant procedure(s), discharge with drains or non-absorbable sutures/staples, complication prior to discharge or pathology positive for malignancy. RESULTS: 1075 patients underwent qualifying procedures, 124 (12 â€‹%) were excluded and 162 (17 â€‹%) did not have follow-up. 443 (56 â€‹%) patients followed-up in-person (56 â€‹%) vs 346 (44 â€‹%) via telehealth. Telehealth patients had a lower rate of complications, 6 â€‹% vs 12 â€‹%, p â€‹= â€‹0.013. There were no significant differences in ED visits, 30-day readmission, postoperative procedures or missed adverse events. CONCLUSION: Telehealth follow-up after general surgical procedures is safe and effective. Postoperative telehealth care should be considered after low-risk general surgery procedures.

Hemoglobin-based oxygen carrier mitigates transfusion-mediated pancreas cancer progression.

BACKGROUND: Perioperative blood transfusion in pancreatic cancer patients is linked to decreased survival; however, a causal mechanism has not been determined. Previously we have shown that the plasma fraction of stored packed red blood cells (pRBCs) promotes pancreas cancer progression and associated morbidity. We hypothesize these untoward effects will be mitigated by use of a hemoglobin-based oxygen carrier (HBOC). METHODS: Cytokines and growth factors were measured in the plasma fraction from stored pRBCs and in an HBOC via cytokine array followed by formal enzyme-linked immunosorbent assay (ELISA). In an immunocompetent murine model, pancreas cancer progression was determined in vivo by bioluminescence, tumor weight, and number of metastases. RESULTS: Elevated levels of epidermal growth factor (EGF), platelet-derived growth factor BB (PDGF-BB), and regulated upon activation, normal T cell expressed and secreted (RANTES) were present in the plasma fraction of stored pRBCs, but were not found in the HBOC. Intravenous delivery of plasma fraction to mice with pancreatic cancer resulted in increased bioluminescence activity compared with mice that received HBOC. Metastatic events and pancreatic primary tumor weights were significantly higher in animals receiving plasma fraction from stored pRBCs compared with animals receiving HBOC. CONCLUSIONS: Intravenous receipt of the acellular plasma fraction of stored pRBCs promotes pancreatic cancer progression in an immunocompetent mouse model. These untoward events are mitigated by use of an HBOC.

Chest computed tomography imaging for blunt pediatric trauma: not worth the radiation risk.

INTRODUCTION: A child's risk of developing cancer from radiation exposure associated with computed tomography (CT) imaging is estimated to be as high as 1/500. Chest CT (CCT), often as part of a "pan-scan," is increasingly performed after blunt trauma in children. We hypothesized that routine CCT for the initial evaluation of blunt injured children does not add clinically useful information beyond chest radiograph (CXR) and rarely changes management. METHODS: Pediatric (<15 y) trauma team evaluations over 6 y at an academic Level I trauma center were reviewed. Demographic data, injuries, imaging, and management were identified for all patients undergoing CT. Effective radiation dose in milliSieverts (mSv) was calculated using age-adjusted scales. RESULTS: Fifty-seven of 174 children (33%) undergoing CT imaging had a CCT; 55 (97%) of these had a CXR. Pathology was identified in significantly fewer CXRs compared with CCTs (51% versus 83%, P < 0.001). All 7/57 (12%) emergent or urgent chest interventions were based on information from CXR. In 53 children (93%), the CCT was ordered as part of a pan-scan, resulting in a radiation dose of 37.69 ± 7.80 mSv from initial CT scans. Radiation dose was significantly greater from CCT than from CXR (8.7 ± 1.1 mSv versus 0.017 ± 0.002 mSv, P < 0.001). CONCLUSIONS: Clinically useful information found on CCT had good correlation to information obtained from CXR and did not change patient management, however, did add significantly to the radiation exposure of initial imaging. We recommend selective use of CCT, particularly in the presence of an abnormal mediastinal silhouette on CXR after a significant deceleration injury.

Activation state of stromal inflammatory cells in murine metastatic pancreatic adenocarcinoma.

The histologic presence of macrophages (tumor-associated macrophages, TAMs) and neutrophils (tumor-associated neutrophils, TANs) has been linked to poor clinical outcomes for solid tumors. The exact mechanism for this association with worsened prognosis is unclear. It has been theorized that TAMs are immunomodulated to an alternatively activated state and promote tumor progression. Similarly, TANs have been shown to promote angiogenesis and tumor detachment. TAMs and TANs were characterized for activation state and production of prometastatic mediators in an immunocompetent murine model of pancreatic adenocarcinoma. Specimens from liver metastases were evaluated by immunofluorescence and immunoblotting. TAMS have upregulated expression of CD206 and CD163 markers of alternative activation, (4.14 ± 0.55-fold and 7.36 ± 1.13-fold over control, respectively, P < 0.001) but do not have increased expression of classically activated macrophage markers CCR2 and CCR5. TAMs also express oncostatin M (OSM). We found that TANs, not TAMs, predominantly produce matrix metalloproteinase-9 (MMP-9) in this metastatic tumor microenvironment, while MMP-2 production is pan-tumoral. Moreover, increased expression of VEGF colocalized with TAMs as opposed to TANs. TAMs and TANs may act as distinct effector cells, with TAMs phenotypically exhibiting alternative activation and releasing OSM and VEGF. TANs are localized at the invasive front of the metastasis, where they colocalize with MMP-9. Improved understanding of these interactions may lead to targeted therapies for pancreas adenocarcinoma.

Effect of damage control surgery on major abdominal vascular trauma.

BACKGROUND: In 1982, we reported our experience with abdominal vascular trauma, highlighting the critical role of hypothermia, acidosis, and coagulopathy. Damage control surgery was subsequently introduced to address this "lethal triad." The purpose of the present study was to evaluate the outcomes from our most recent 6-year experience compared with a cohort from 30 years ago. METHODS: Patients with major abdominal vascular injuries were examined, and the most recent 6-year period was compared with archived data from a similar 6-year period three decades ago. RESULTS: The number of patients with major abdominal vascular injuries decreased from 123 patients in 1975 to 1980 to 64 patients in 2004 to 2009. The mean initial pH decreased from 7.21 to 6.96 (1975 to 1980 versus 2004 to 2009) for patients with overt coagulopathy. Despite increasingly protracted acidosis, mortality attributable to refractory coagulopathy decreased from 46% to 19% (1975 to 1980 versus 2004 to 2009, chi-square = 4.36, P = 0.04). No significant difference was found in mortality from exsanguinating injuries (43% versus 62%, 1975 to 1980 versus 2004 to 2009, chi-square = 1.96, P = 0.16). The prehospital transport times were unchanged (22 versus 20 min, 1975 to 1980 versus 2004 to 2009). Despite the administration of additional clotting factors and the advent of damage control surgery, the overall mortality remained largely unchanged (37% versus 33%, 1975 to 1980 versus 2004 to 2009, chi-square = 0.385, P = 0.53). CONCLUSIONS: The adoption of damage control surgery, including the implementation of a massive transfusion protocol, was associated with a reduction in mortality for abdominal vascular injuries due to coagulopathy; however, patients have continued to die of exsanguination.

Decreases in daily ambulation forecast post-surgical re-admission.

BACKGROUND: Surgical readmissions are clinically and financially problematic. Our purpose is to determine if a decrease in postoperative ambulation (steps/day) is associated with hospital readmission. METHODS: In this prospective cohort study, patients undergoing elective operations wore an accelerometer activity tracker to measure steps/day for 28 consecutive postoperative days. The primary outcome was hospital readmission. The change in steps/day over two consecutive days prior to the day of the readmission were examined. Predetermined thresholds for decreases of consecutive daily ambulation levels were used to calculate sensitivity and specificity for the outcome of hospital readmission. RESULTS: 215 patients (aged 63 ± 12 years) were included. Readmission occurred in 10% (n = 21). For each of the first 28-postoperative days, the entire cohort had an average daily step increase of 136 ± 146 steps/day (Spearman correlation rho = 0.990; p < 0.001). A decrease in steps for two consecutive days of >50% from the prior day had a 79% sensitivity and 90% specificity for hospital readmission. CONCLUSIONS: A decrease of >50% daily ambulation (steps/day) over two consecutive post-discharge days accurately forecasts hospital readmission. The implications of these findings are that monitoring daily ambulation could serve as a form of outpatient telemetry aiding to forecast post-surgical readmissions.

Post-discharge venous thromboembolism after cancer surgery: extending the case for extended prophylaxis.

OBJECTIVE: To (1) define the frequency of overall and postdischarge venous thromboembolism (VTE) after cancer surgery, (2) identify VTE risk for individual cancer operations, and (3) assess mortality rates in patients who experienced a VTE. SUMMARY AND BACKGROUND DATA: Cancer is a known risk factor for VTE but less is known about VTE risk after specific cancer operations. Moreover, most cancer patients routinely receive VTE prophylaxis postoperatively while in the hospital, but few receive prolonged prophylaxis despite strong evidence it reduces postdischarge events. METHODS: From 211 ACS NSQIP hospitals, 44,656 patients undergoing surgery for 9 cancers were identified (2006-2008). The frequency of VTE within 30-days of surgery was evaluated by cancer site and categorized as occurring before or after discharge. Multivariable logistic regression models were constructed to assess risk factors associated with VTE. RESULTS: VTE occurred in 1.6% of all patients, most frequently after esophagogastric (4.2%) and hepatopancreaticobiliary (3.6%) surgery. Overall, 33.4% of VTEs occurred postdischarge (from 17.9% for esophagogastric to 100% for endocrine operations). Factors associated with VTE were age (≥65 years), cancer/procedure type, metastatic disease, congestive heart failure, body mass index (BMI; ≥25 kg/m(2)), ascites, thrombocytosis (>400,000 cells/mm(3)), albumin (<3.0 g/dL), and operation duration (>2 hours; all P < 0.001). Overall VTE was significantly more likely after gastrointestinal, lung, prostate, and ovarian/uterine operations (all P < 0.001). In those experiencing a VTE, mortality increased over 6-fold (8.0% vs. 1.3%; P < 0.001). CONCLUSION: One-third of VTE events in cancer surgery patients occurred postdischarge. Postoperative VTE was associated with operation type. Routine postdischarge VTE prophylaxis should be considered for high-risk patients.

Perioperative blood transfusions promote pancreas cancer progression.

Complex abdominal procedures to extirpate malignancies are often associated with blood transfusion. In particular, perioperative transfusion rates for pancreaticoduodenectomy can be as high as 75%. In the early 1970s it was shown that blood transfusions likely had immunomodulating effects as renal allografts were found to have longer survival in patients who received multiple transfusions. Subsequently, it has been suggested that blood transfusions may promote cancer progression. Many retrospective series have supported this hypothesis, and recent studies examining long-term survival in patients undergoing "Whipple" procedures suggests that transfusion is a negative prognostic factor. Despite these studies, the claim that transfusion is a simple surrogate for patient health, tumor size, location, and biology are difficult to refute. The use of syngeneic murine models has allowed many confounding variables to be controlled, and suggest that transfusion does indeed promote pancreas cancer progression. Based on these findings, as well as the continued need for blood transfusion, alternate strategies in transfusion management are warranted.