From the simulation center to the bedside: Validating the efficacy of a dynamic haptic robotic trainer in internal jugular central venous catheter placement.

BACKGROUND: The objective of this study was to validate the transfer of ultrasound-guided Internal Jugular Central Venous Catheterization (US-IJCVC) placement skills from training on a Dynamic Haptic Robotic Trainer (DHRT), to placing US-IJCVCs in clinical environments. DHRT training greatly reduces preceptor time by providing automated feedback, standardizes learning experiences, and quantifies skill improvements. METHODS: Expert observers evaluated DHRT-trained (N = 21) and manikin-trained (N = 36) surgical residents on US-IJCVC placement in the operating suite using a US-IJCVC evaluation form. Performance and errors by DHRT-trained residents were compared to traditional manikin-trained residents. RESULTS: There were no significant training group differences between unsuccessful insertions (p = 0.404), assistance on procedure (p = 0.102), arterial puncture (p = 0.998), and average number of insertion attempts (p = 0.878). Regardless of training group, previous central line experience significantly predicted whether residents needed assistance on the procedure (p = 0.033). CONCLUSION: The results failed to show a statistical difference between DHRT- and manikin-trained residents. This study validates the transfer of skills from training on the DHRT system to performing US-IJCVC in clinical environments.

Morbidity after tonsillectomy in children with autism spectrum disorders.

OBJECTIVES: As the incidence of autism spectrum disorder (ASD) increases, otolaryngologists are more likely to encounter patients from this population during tonsillectomy. The purpose of this study was to examine whether outcomes differ between pediatric patients with and without ASD in a national cohort of children undergoing tonsillectomy. Understanding these differences may be used to inform future approaches to improve clinical outcomes and healthcare costs. METHODS: Data for this study were obtained from the Kids Inpatient Database (KID) of the Healthcare Cost Utilization Project. We studied pediatric patients who underwent tonsillectomy during 2003, 2006, 2009, and 2012. Tonsillectomy was identified using ICD-9-CM diagnosis codes 28.2 (tonsillectomy without adenoidectomy) and 28.3 (tonsillectomy with adenoidectomy). ASD was identified using ICD-9-CM diagnosis code 299 (autism). Outcomes including complications, length of hospital stay, and total hospitalization costs. Analyses were performed using multivariable models. Propensity score matching was used to control for covariate imbalance between patients with and without ASD. RESULTS: In our sample of 27,040 patients, 322 (1.2%) had a diagnosis of ASD. After controlling for potential confounders, multivariable modeling suggested patients with ASD had a shorter LOS of 0.50 days (p < 0.0001), were less likely to experience complications (odds ratio 0.57, p = 0.001), and had lower associated costs of $1308 less (p < 0.0001). Propensity score matching confirmed the findings of the multivariable modeling. CONCLUSION: Although ASD alone does not appear to confer additional costs or morbidity, differences between children with and without ASD suggest the need for providers to address patients with ASD uniquely.

Peritoneal encapsulation: a rare cause of small bowel obstruction.

Peritoneal encapsulation syndrome (PES) is a rare cause of small bowel obstruction (SBO) in patients with no prior history of abdominal surgery. First described by Cleland in 1868, PES is a congenital condition characterised by small bowel encasement in an accessory, but otherwise normal peritoneal membrane. 1 2 A result of abnormal rotation of the midgut during early development, the condition causes fibrous encapsulation of the intestines, thus preventing bowel distention.3 While preoperative diagnosis is difficult, several case reports have described clinical and imaging signs that can help clinicians with not only recognising the condition but also preparing appropriately for perioperative discovery of anatomical variants. 3 4.

Can Haptic Simulators Distinguish Expert Performance? A Case Study in Central Venous Catheterization in Surgical Education.

INTRODUCTION: High-tech simulators are gaining popularity in surgical training programs because of their potential for improving clinical outcomes. However, most simulators are static in nature and only represent a single anatomical patient configuration. The Dynamic Haptic Robotic Training (DHRT) system was developed to simulate these diverse patient anatomies during Central Venous Catheterization (CVC) training. This article explores the use of the DHRT system to evaluate objective metrics for CVC insertion by comparing the performance of experts and novices. METHODS: Eleven expert surgeons and 13 first-year surgical residents (novices) performed multiple needle insertion trials on the DHRT system. Differences between expert and novice performance on the following five metrics were assessed using a multivariate analysis of variance: path length, standard deviation of deviations (SDoD), average velocity, distance to the center of the vessel, and time to complete (TtC) the needle insertion. A regression analysis was performed to identify if expertise could be predicted using these metrics. Then, a curve fit was conducted to identify whether learning curves were present for experts or novices on any of these five metrics. RESULTS: Time to complete the insertion and SDoD of the needle tip from an ideal path were significantly different between experts and novices. Learning curves were not present for experts but indicated a significant decrease in path length and TtC for novices. CONCLUSIONS: The DHRT system was able to identify significant differences in TtC and SDoD between experts and novices during CVC needle insertion procedures. In addition, novices were shown to improve their skills through DHRT training.

Prognostic Significance of Tumor Deposits in Stage III Colon Cancer.

BACKGROUND: The American Joint Committee on Cancer includes extranodal tumor deposits in the tumor-node-metastasis classification of colon cancer. However, it is unclear how tumor deposits compare with lymph node metastases in prognostic significance. This study evaluated the survival impact of tumor deposits relative to lymph node metastases in stage III colon cancer. METHODS: The US National Cancer Database (2010-2012) was reviewed for resectable stage III adenocarcinoma of the colon, and stratified by presence of tumor deposits and lymph node metastases. Univariate and multivariate survival analyses were performed. RESULTS: Of 6424, 10.1% had both tumor deposits and lymph node metastases [5-year survival (5YS) 40.2%], 2.5% had tumor deposits alone (5YS 68.1%), and 87.4% had lymph node metastases alone (5YS 55.4%). Patients with lymph node metastases alone tended to have a greater number of lymph nodes retrieved (20.9 versus 18.8, p = 0.0126) and were more likely to receive adjuvant therapy (66.9 vs 58.0%, p = 0.003) than those with only tumor deposits. Patients with both had significantly worse survival at all T stages (p < 0.05, all). There was no significant difference in survival between tumor deposits alone and lymph node metastases alone at any T stage (p > 0.8, all). After controlling for patient, disease, and treatment characteristics, patients with tumor deposits alone [hazard ratio (HR) 0.56, p = 0.001] or only lymph node metastases (HR 0.64, p < 0.001) were associated with improved survival relative to patients with both. CONCLUSIONS: Concomitant presence of tumor deposits and lymph node invasion carries poor prognostic significance. Tumor deposits alone appear to have prognostic implications similar to lymph node invasion alone.

Robotic versus standard laparoscopic elective colectomy: where are the benefits?

BACKGROUND: Robotic approaches for colorectal surgery have been growing in popularity as experience with the new technology develops, but are frequently associated with longer operative time. It is unclear whether prolonged operative duration in robotic cases translates to increased morbidity. This study aims to compare the outcomes of non-emergent laparoscopic and robotic colon resections. METHODS: Patients undergoing non-emergent laparoscopic (LC) or robotic (RC) colon resections were identified in National Surgical Quality Improvement Project (2013-2015). Patients were matched 1:1 between cohorts using propensity score matching. To account for the prolonged operative time associated with robotic cases, operative times were stratified into approach-specific (LC or RC) tertiles (low, medium, and high) as covariates in the matching algorithm. RESULTS: RC increased significantly over time and had lower conversion rates (6.0% among RC versus 11.5% among LC, P < 0.001). RC cases were longer (226 min versus 178 min, P < 0.001). Unadjusted complication rates were higher in the LC cohort (17.5% versus 15.2%, P < 0.001). After propensity score matching, RC was not associated with a significant difference in postoperative morbidity (15.2% among RC versus 15.9% among LC, P = 0.434). The robotic approach was associated with a one-half day shorter length of stay (4.6 d versus 5.2 d, P < 0.001), but similar 30-day readmission rates (8.9% versus 8.3%, P = 0.368). CONCLUSIONS: After controlling for operative duration and patient covariates, RC was associated with similar rates of postoperative morbidity, but decreased conversion rates and shorter length of stay. Further studies examining costs are needed to evaluate whether these benefits offset the increased costs associated with robotic approaches.

Time to Surgery: a Misguided Quality Metric in Early Stage Pancreatic Cancer.

BACKGROUND: Longer time to surgery is associated with worse outcomes in several cancers. We sought to identify disparities in time from diagnosis to surgery in pancreatic cancer and whether delays to surgery correlated with worse survival. METHODS: The US National Cancer Database (2003-2011) was reviewed for patients with clinical stages I-II pancreatic adenocarcinoma who underwent surgical resection. Patients who received neoadjuvant therapy were excluded. Linear regression, Kaplan-Meier analyses, and Cox regression were performed as 3-month landmark analyses. RESULTS: Of the 14,807 patients included, 37.8% underwent resection ≤ 1 week, 13.7% 1-2 weeks, 25.4% 2-4 weeks, 19.5% 4-8 weeks, and 3.7% 8-12 weeks. Older age, Medicare coverage, greater distance from hospital, treatment at an academic center, and greater comorbidities were associated with increased time. After excluding patients treated within 1 week of diagnosis and controlling for patient, disease, and treatment characteristics, greater time was not associated with worse survival (2-4, HR 1.03, P = 0.399; 4-8, HR 0.98, P = 0.529; 8-12, P = 0.123). CONCLUSIONS: For patients with stages I-II pancreatic adenocarcinoma, there are disparities in surgical wait times. However, earlier initiation of surgical resection within 12 weeks of diagnosis is not associated with a survival benefit. This suggests that allowing time for confirmatory testing and optimization in preparation for surgery may not negatively impact survival.

Investigating the Effect of Simulator Functional Fidelity and Personalized Feedback on Central Venous Catheterization Training.

OBJECTIVE: To compare the effect of simulator functional fidelity (manikin vs a Dynamic Haptic Robotic Trainer [DHRT]) and personalized feedback on surgical resident self-efficacy and self-ratings of performance during ultrasound-guided internal jugular central venous catheterization (IJ CVC) training. In addition, we seek to explore how self-ratings of performance compare to objective performance scores generated by the DHRT system. DESIGN: Participants were randomly assigned to either manikin or DHRT IJ CVC training over a 6-month period. Self-efficacy surveys were distributed before and following training. Training consisted of a pretest, 22 practice IJ CVC needle insertion attempts, 2 full-line practice attempts, and a posttest. Participants provided self-ratings of performance for each needle insertion and were presented with feedback from either an upper level resident (manikin) or a personalized learning system (DHRT). SETTING: A study was conducted from July 2016 to February 2017 through a surgical skills training program at Hershey Medical Center in Hershey, Pennsylvania. PARTICIPANTS: Twenty-six first-year surgical residents were recruited for the study. Individuals were informed that IJ CVC training procedures would be consistent regardless of participation in the study and that participation was optional. All recruited residents opted to participate in the study. RESULTS: Residents in both groups significantly improved their self-efficacy scores from pretest to posttest (p < 0.01). Residents in the manikin group consistently provided higher self-ratings of performance (p < 0.001). Residents in the DHRT group recorded more feedback on errors (228 instances) than the manikin group (144 instances). Self-ratings of performance on the DHRT system were able to significantly predict the objective score of the DHRT system (R2 = 0.223, p < 0.001). CONCLUSION: Simulation training with the DHRT system and the personalized learning feedback can improve resident self-efficacy with IJ CVC procedures and provide sufficient feedback to allow residents to accurately assess their own performance.

Correlation of clinical and pathological staging and response to neoadjuvant therapy in resected pancreatic cancer.

BACKGROUND: Neoadjuvant therapy (NAT) has been increasingly employed to optimize outcomes in pancreatic cancer; however, little is known about its pathologic impact. METHODS: The National Cancer Data Base (2003-2011) was retrospectively reviewed for patients with pancreatic carcinoma who underwent initial surgery or NAT followed by resection. Response to NAT, determined by comparing clinical and pathologic stage, and survival were evaluated. RESULTS: 16,087 patients underwent initial pancreatectomy and 2307 patients received NAT. Clinical stage correlated poorly with pathological stage in patients who received initial surgery (κ = 0.2865, p < 0.001). With NAT, 21.9% were downstaged, 47.9% had no stage change, and 30.3% progressed. In clinical stage II disease, patients downstaged with neoadjuvant chemotherapy or multimodality therapy demonstrated improved survival over patients who did not respond or who progressed (P = 0.0022, P = 0.0012, respectively). This benefit was not preserved in stage III disease (P = 0.7380, P = 0.0726, respectively). In multivariable analysis, downstage in disease was associated with a 19% lower hazard of mortality (HR 0.81, 95% CI: 0.7-0.92, P = 0.002). CONCLUSIONS: Clinical stage correlates poorly with pathological stage in resectable pancreatic cancer. The majority of patients do not experience a change in stage with NAT. Those with early stage disease, responsive to NAT, experience a survival benefit.

Integrating Cadaver Needle Forces Into a Haptic Robotic Simulator.

Accurate force simulation is essential to haptic simulators for surgical training. Factors such as tissue inhomogeneity pose unique challenges for simulating needle forces. To aid in the development of haptic needle insertion simulators, a handheld force sensing syringe was created to measure the motion and forces of needle insertions. Five needle insertions were performed into the neck of a cadaver using the force sensing syringe. Based on these measurements a piecewise exponential needle force characterization, was implemented into a haptic central venous catheterization (CVC) simulator. The haptic simulator was evaluated through a survey of expert surgeons, fellows, and residents. The maximum needle insertion forces measured ranged from 2.02 N to 1.20 N. With this information, four characterizations were created representing average, muscular, obese, and thin patients. The median survey results showed that users statistically agreed that "the robotic system made me sensitive to how patient anatomy impacts the force required to advance needles in the human body." The force sensing syringe captured force and position information. The information gained from this syringe was able to be implemented into a haptic simulator for CVC insertions, showing its utility. Survey results showed that experts, fellows, and residents had an overall positive outlook on the haptic simulator's ability to teach haptic skills.

Robotic versus laparoscopic colectomy for stage I-III colon cancer: oncologic and long-term survival outcomes.

BACKGROUND: While short-term data suggest that robotic resections are safe for oncologic operations, long-term outcomes remain uncertain. This study evaluates the impact of robotic and laparoscopic approaches on oncologic and survival outcomes in partial and total colectomies for colon cancer. METHODS: The US National Cancer Database (2010-2012) was reviewed for patients with stage I-III adenocarcinoma of the colon, who underwent robotic and laparoscopic partial or total colectomies. Lymph node retrieval, surgical margins, and survival were compared between surgical approaches with linear and logistic regressions. Propensity score matching was then used to create comparable laparoscopic and robotic cohorts and compare survivor functions. RESULTS: Of 15,112 patients, 5.1% underwent robotic approaches (n = 765, conversion rate 10.6%), and 94.9% laparoscopic (n = 14,347, conversion rate 15.1%). Robotic approach was associated with Hispanic race (p = 0.009), private insurance (p = 0.001), and earlier stage (p = 0.028). There was no difference in number of lymph nodes retrieved (p = 0.6200) or negative surgical margins (p = 0.6700). In multivariate analysis, robotic approaches were associated with an improved hazard of mortality (HR 0.79, p = 0.027). Linear regression found no difference in lymph node retrieval (- 0.39, p = 0.285). Logistic regression found no difference in rates of positive margins (OR 1.09, p = 0.649). After propensity score matching, robotic approaches were associated with improved survival in stage II (5YS 66.9% vs. 56.8%, p = 0.0189) and III disease (5YS 78.6% vs. 64.9%, p = 0.0241). CONCLUSION: Robotic approaches to partial and total colectomies for stage I-III colon cancer offer comparable oncologic outcomes as laparoscopic approaches. Relative to laparoscopic approaches, robotic approaches appear to offer improved long-term survival.

Minimally invasive surgical approaches offer earlier time to adjuvant chemotherapy but not improved survival in resected pancreatic cancer.

BACKGROUND: Pancreatic surgery encompasses complex operations with significant potential morbidity. Greater experience in minimally invasive surgery (MIS) has allowed resections to be performed laparoscopically and robotically. This study evaluates the impact of surgical approach in resected pancreatic cancer. METHODS: The National Cancer Data Base (2010-2012) was reviewed for patients with stages 1-3 resected pancreatic carcinoma. Open approaches were compared to MIS. A sub-analysis was then performed comparing robotic and laparoscopic approaches. RESULTS: Of the 9047 patients evaluated, surgical approach was open in 7511 (83%), laparoscopic in 992 (11%), and robotic in 131 (1%). The laparoscopic and robotic conversion rate to open was 28% (n = 387) and 17% (n = 26), respectively. Compared to open, MIS was associated with more distal resections (13.5, 24.3%, respectively, p < 0.0001), shorter hospital length of stay (LOS) (11.3, 9.5 days, respectively, p < 0.0001), more margin-negative resections (75, 79%, p = 0.038), and quicker time to initiation of chemotherapy (TTC) (59.1, 56.3 days, respectively, p = 0.0316). There was no difference in number of lymph nodes obtained based on surgical approach (p = 0.5385). When stratified by type of resection (head, distal, or total), MIS offered significantly shorter LOS in all types. Multivariate analysis demonstrated no survival benefit for any MIS approach relative to open (all, p > 0.05). When adjusted for patient, disease, and treatment characteristics, TTC was not an independent prognostic factor (HR 1.09, p = 0.084). CONCLUSION: MIS appears to offer comparable surgical oncologic benefit with improved LOS and shorter TTC. This effect, however, was not associated with improved survival.

Prognostic impact of carbohydrate antigen 19-9 level at diagnosis in resected stage I-III pancreatic adenocarcinoma: a U.S. population study.

BACKGROUND: Pancreatic adenocarcinoma is a highly aggressive cancer, with surgical resection and systemic therapy offering the only hope for long-term survival. Carbohydrate antigen 19-9 (CA 19-9) has been used as a prognostic marker after resection; however, the relationship between survival and pre-treatment CA 19-9 level remains unclear. This study evaluates pre-treatment serum CA 19-9 level as a predictor for long-term survival. METHODS: The U.S. National Cancer Data Base [2004-2012] was reviewed for patients with clinical stages I-III resected pancreatic adenocarcinoma with recorded pre-treatment CA 19-9 levels (U/mL). Kaplan Meier and Weibull survival analyses were performed. RESULTS: Four thousand seven hundred and one patients were included: 12.6% received neoadjuvant therapy (NAT), 27.4% underwent surgery, and 60.1% underwent surgery and adjuvant therapy. Amongst those who underwent initial surgery, there was no association between CA 19-9 levels ≤800 (≤100, 101-300, 301-500, 501-800) with survival (stage I P=0.7592, stage II P=0.5088, stage III P=0.9037). Levels >800 were associated with significantly worse survival in all stages (P≤0.0001, all). Amongst those who received NAT, levels >800 were associated with worse survival in early (stage I P=0.0001), but not advanced stage disease (stage II P=0.1891, stage III P=0.9316). In multivariable analyses, levels >800 demonstrated a 3.29 greater hazard of mortality with respect to patients with levels ≤100 (P<0.0001). CONCLUSIONS: Pre-treatment CA 19-9 levels >800 appear to be associated with advanced disease, and are negatively associated with long-term survival. However, levels ≤800 had no significant association with survival. Although this study suggests an association, further study is needed to evaluate whether patients with CA 19-9 levels >800 benefit from NAT.

Greater lymph node retrieval and lymph node ratio impacts survival in resected pancreatic cancer.

BACKGROUND: Surgical resection is the mainstay of pancreatic cancer treatment; however, the ideal lymphadenectomy remains unsettled. This study sought to determine whether number of examined lymph nodes (eLNs) and lymph node ratio (LNR) impact survival. METHODS: The U.S. National Cancer Data Base (2003-2011) was reviewed for patients who underwent initial resection for clinical stage I and II pancreatic adenocarcinoma. Univariate and multivariate survival analyses were performed. RESULTS: Of 14,007 patients, 15.6% had 0-6 eLN, 27.1% 7-12, 13.4% 13-15, and 38.6% > 15 eLN. Median eLN was 11 for pancreaticoduodenectomy, and 14 for distal, total pancreatectomy, or other procedure. ELN >15 was associated with significantly improved survival in both node negative and positive disease (P < 0.001, both). In multivariable analysis, 7-12, 13-15, and >15 eLN had improved survival relative to 0-6 eLN (HR 0.87, P < 0.001, HR 0.89, P = 0.002, HR 0.82, P < 0.001, respectively). A total of 34.5% of patients had an LNR of 0, 31.5% ≤ 0.2, 20.3% 0.2-0.4, 11.7% 0.4-0.8, and 2.0% had an LNR >0.8. Patients with LNR 0 had improved survival in T1-T3 disease (P < 0.01). In multivariable analysis, higher LNR was negatively associated with survival (LNR 0-0.2: HR 1.44, P < 0.001, LNR 0.2-0.4: HR 1.82, P < 0.001, LNR 0.4-0.8: 2.03, P < 0.001, LNR >0.8, P < 0.001). Even with suboptimal eLN (eLN ≤6 or ≤12), higher LNR remained an independent predictor of mortality. CONCLUSIONS: Greater lymph node retrieval in stage I & II pancreatic adenocarcinoma may have prognostic value, even in node-negative disease. Lymph node ratio is inversely related to survival and may be useful with suboptimal eLN.

Utilization and trends in palliative therapy for stage IV pancreatic adenocarcinoma patients: a U.S. population-based study.

BACKGROUND: Pancreatic adenocarcinoma is an aggressive malignancy, with most patients diagnosed with advanced or metastatic disease. Palliative therapies comprise an important, but underutilized, aspect of care. This aim of this study was to characterize the trends, factors, and outcomes associated with utilization of palliative therapies. METHODS: Patients with stage IV pancreatic adenocarcinoma from the 2003-2011 U.S. National Cancer Database were identified and stratified by receipt of palliative therapy. Linear regression, multivariable logistic regression, and survival analyses using multivariate proportional hazards models were performed. RESULTS: Sixty-eight thousand and seventy-five patients with stage IV disease were identified, of which only 11,449 (16.8%) underwent designated palliative therapy. The majority received systemic chemotherapy (37.2%), followed by surgery (19.0%), pain management alone (15.3%), radiation (8.1%), referral alone (11.7%), or a combination thereof (8.7%). Utilization of palliative therapies increased from 12.9% in 2003 to 19.2% in 2011 (P<0.001). Patients were less likely to undergo palliation when older than 60 (OR 0.89, P<0.001), or of black or Hispanic race (OR 0.83, P<0.001; OR 0.80, P<0.001, respectively, vs. Caucasians). Presence of comorbidities increased the use of palliative therapy (OR 1.16 per comorbidity, P<0.001). Survival was improved in those receiving palliative systemic chemotherapy (HR 0.55, P<0.001) and palliative surgery (HR 0.94, P<0.001), although this may be due to selection bias. CONCLUSIONS: Despite the continued dismal prognosis of pancreatic cancer, palliation of symptoms remains underutilized in this country, particularly in non-Caucasian, older patients. Increased awareness of palliative options may help increase its utilization.

Risk factors for 30-day readmission in patients with congestive heart failure.

BACKGROUND: Risk of readmission is elevated in patients congestive heart failure (CHF), and clinical decision makers need to better understand risk factors for 30-day readmissions. OBJECTIVE: To identify risk factors for readmission in patients with CHF. METHODS: We studied all admissions for patients with CHF during 2011 using a statewide discharge data set from Pennsylvania. The primary outcome was readmission to any Pennsylvania hospital within 30 days of discharge. RESULTS: Of 155,146 CHF patients admitted, 35,294 (22.8%) were readmitted within 30 days. Male sex, black race, coverage by Medicare, comorbidities, discharge to a skilled nursing facility or with a home nurse, a longer length of stay (LOS), admission from another facility, and emergent admission (all p < 0.001) were significant risk factors. CONCLUSIONS: Comorbidities, sociodemographic factors including male sex, age, black race and Medicare coverage, and prolonged length of stay are associated with increased risk of readmission in patients with CHF.

Sarcopenia related to neoadjuvant chemotherapy and perioperative outcomes in resected gastric cancer: a multi-institutional analysis.

BACKGROUND: This study's objective was to evaluate the change in sarcopenia score following neoadjuvant chemotherapy (NAC) and to correlate both sarcopenia and change in score with perioperative outcomes in patients with advanced resected gastric cancer. METHODS: Multi-institutional analysis of patients with gastric cancer who underwent NAC and resection from 2000-2015 was performed. Demographic and perioperative data were included. Sarcopenia score was defined as CT measurement of total psoas muscle at L3, stratified by height (m). Sarcopenia was defined as a score <385 mm2/m2 in women and <545 mm2/m2 in men. RESULTS: Of 36 patients, 19% were sarcopenic prior to NAC. Following NAC, 31% were sarcopenic, with 14% developing sarcopenia during NAC. One patient (3%) became non-sarcopenic. There were no significant differences in patient, disease, or surgery characteristics between patients who were sarcopenic vs. not. Patients with sarcopenia were more likely to have post-operative complications (P=0.05). There was no significant difference in hospital stay (P=0.7402) or survival (P=0.2317). CONCLUSIONS: A significant number of patients with gastric cancer become sarcopenic during NAC. Although patients with sarcopenia were nearly twice as likely to develop post-operative complications, this did not appear to impact length of stay (LOS) or survival.

Training Surgical Residents With a Haptic Robotic Central Venous Catheterization Simulator.

OJECTIVE: Ultrasound guided central venous catheterization (CVC) is a common surgical procedure with complication rates ranging from 5 to 21 percent. Training is typically performed using manikins that do not simulate anatomical variations such as obesity and abnormal vessel positioning. The goal of this study was to develop and validate the effectiveness of a new virtual reality and force haptic based simulation platform for CVC of the right internal jugular vein. DESIGN: A CVC simulation platform was developed using a haptic robotic arm, 3D position tracker, and computer visualization. The haptic robotic arm simulated needle insertion force that was based on cadaver experiments. The 3D position tracker was used as a mock ultrasound device with realistic visualization on a computer screen. Upon completion of a practice simulation, performance feedback is given to the user through a graphical user interface including scoring factors based on good CVC practice. The effectiveness of the system was evaluated by training 13 first year surgical residents using the virtual reality haptic based training system over a 3 month period. RESULTS: The participants' performance increased from 52% to 96% on the baseline training scenario, approaching the average score of an expert surgeon: 98%. This also resulted in improvement in positive CVC practices including a 61% decrease between final needle tip position and vein center, a decrease in mean insertion attempts from 1.92 to 1.23, and a 12% increase in time spent aspirating the syringe throughout the procedure. CONCLUSIONS: A virtual reality haptic robotic simulator for CVC was successfully developed. Surgical residents training on the simulation improved to near expert levels after three robotic training sessions. This suggests that this system could act as an effective training device for CVC.

Impact of perineural invasion on survival in node negative colon cancer.

Perineural invasion (PNI) has been implicated as a poor prognostic indicator in many cancers. The National Comprehensive Cancer Network recommends consideration of observation or adjuvant therapy in the presence of PNI in early colon cancer. These recommendations are based on single institutional studies that fail to evaluate PNI within the context of adjuvant chemotherapy. The US National Cancer Database (2004-2012) was reviewed for patients with node negative colon cancer, and stratified by PNI and receipt of chemotherapy. Of 21,488 patients evaluated, 55.2% had T3 disease (n = 11,852), 23.1% had T2 (n = 4,971), 14.4% had T1 (n = 3,088), and 7.3% had T4 disease (n = 1,577); 4.6% (n = 987) had PNI. Most patients (86.8%, n = 18,641) did not have PNI and did not receive chemotherapy; 8.7% (n = 1,860) did not have PNI but received chemotherapy; 3.7% (n = 785) had PNI and did not receive chemotherapy, and 0.9% (n = 202) had PNI and received chemotherapy. Among those with PNI, patients who received chemotherapy tended to be younger (P<0.001), covered by private insurance (P<0.001), with fewer comorbidities (P<0.001), and greater T stage disease (P<0.001). Those with PNI who received chemotherapy had significantly improved survival over those who did not in T3-4 disease (P<0.001), but not in T1-2 disease. On multivariate analysis, those with PNI had a 38% greater hazard of mortality (HR 1.38, P<0.001). Additionally, chemotherapy decreased the hazard of mortality by 43% (HR 0.57, P<0.001). PNI appears to be an independent poor prognostic indicator in stage T3-4 node negative colon cancer. Chemotherapy administered to this patient population is associated with improved survival.

Impact of chromogranin A, differentiation, and mitoses in nonfunctional pancreatic neuroendocrine tumors ≤ 2 cm.

BACKGROUND: Small pancreatic neuroendocrine tumors (PNETs) are a unique subset of pancreatic neoplasms. Chromogranin A (CgA) levels, mitotic rate, and histologic differentiation are often used to characterize PNET behavior. This study evaluates the impact of these factors on survival in patients with PNETs. METHODS: The US National Cancer Data Base (1998-2012) was reviewed for patients with stages I-III, nonfunctional PNETs ≤2 cm. Clinicopathologic characteristics were collected, and univariate and multivariate survival analyses were performed. RESULTS: Of 1159 patients, 872 had tumor differentiation recorded, 403 had mitotic rate, and 217 patients had CgA. Mitotic rate >20 mitoses per 10 high-power microscopic fields was significantly associated with survival (hazard ratio [HR] = 10.6, P = 0.002) in multivariate analysis. Of those who underwent resection, there was no significant difference in positive lymph nodes between high (>100 ng/mL) and low (≤100 ng/mL) CgA levels (0.27 versus 0.37, P = 0.4440). Multivariate analyses of patients with both grade and CgA recorded found poorly differentiated tumors and very high CgA (>400 ng/mL) negatively impacted survival (HR = 2.99, P < 0.0001, HR = 3.47, P < 0.0001, respectively). Propensity score matching demonstrated improved 5-y survival in patients who underwent surgical resection, P < 0.0001. CONCLUSIONS: Poorly differentiated disease should be considered an indicator of worse prognosis in nonfunctional PNETs ≤2 cm. Surgical resection appears to improve survival in these patients.