Para-aortic Lymph Node Dissection for Colorectal Cancer: Predicting Pathologic Lymph Node Positivity and Optimizing Outcomes.

INTRODUCTION: In colorectal cancer, the presence of para-aortic lymph nodes (PALN) indicates extraregional disease. Appropriately selecting patients for whom PALN dissection will provide oncologic benefit remains challenging. This study identified factors to predict survival among patients undergoing PALN dissection for colorectal cancer. METHODS: An institutional database was queried for patients who underwent curative-intent resection of clinically positive PALN for colorectal cancer between 2007 and 2020. Preoperative radiologic images were reviewed, and patients who did and did not have positive PALN on final pathology were compared. Survival analysis was performed to evaluate the impact of pathologically positive PALN on recurrence-free (RFS) and overall survival (OS). RESULTS: Of 74 patients who underwent PALN dissection, 51 had PALN metastasis at the time of primary tumor diagnosis, whereas 23 had metachronous PALN disease. Preoperative chemotherapy ± radiotherapy was given in 60 cases (81.1%), and 28 (37.8%) had pathologically positive PALN. Independent factors associated with positive PALN pathology included metachronous PALN disease and pretreatment and posttreatment radiographically abnormal PALN. On multivariable analysis, pathologically positive PALN was significantly associated with decreased RFS (hazard ratio 3.90) and OS (HR 4.49). Among patients with pathologically positive PALN, well/moderately differentiated histology was associated with better OS, and metachronous disease trended toward an association with better OS. CONCLUSIONS: Pathologically positive PALN are associated with poorer RFS and OS after PALN dissection for colorectal cancer. Clinicopathologic factors may predict pathologic PALN positivity. Curative-intent surgery may provide benefit, especially in patients with well-to-moderately differentiated primary tumors and possibly metachronous PALN disease.

Early Postoperative Prediction of Complications and Readmission After Colorectal Cancer Surgery Using an Artificial Neural Network.

BACKGROUND: Early predictors of postoperative complications can risk-stratify patients undergoing colorectal cancer surgery. However, conventional regression models have limited power to identify complex nonlinear relationships among a large set of variables. We developed artificial neural network models to optimize the prediction of major postoperative complications and risk of readmission in patients undergoing colorectal cancer surgery. OBJECTIVE: The aim of this study was to develop an artificial neural network model to predict postoperative complications using postoperative laboratory values, and compare these models' accuracy to standard regression methods. DESIGN: This retrospective study included patients who underwent elective colorectal cancer resection between January 1, 2016, and July 31, 2021. Clinical data, cancer stage, and laboratory data from postoperative day 1 to 3 were collected. Models of complications and readmission risk were created using multivariable logistic regression and single-layer neural networks. SETTING: National Cancer Institute-Designated Comprehensive Cancer Center. PATIENTS: Adult colorectal cancer patients. MAIN OUTCOME MEASURES: Accuracy of predicting postoperative major complication, readmission and anastomotic leak using the area under the receiver-operating characteristic curve. RESULTS: Neural networks had larger areas under the curve for predicting major complications compared to regression models (neural network 0.811; regression model 0.724, p < 0.001). Neural networks also showed an advantage in predicting anastomotic leak (p = 0.036) and readmission using postoperative day 1-2 values (p = 0.014). LIMITATIONS: Single-center, retrospective design limited to cancer operations. CONCLUSIONS: In this study, we generated a set of models for early prediction of complications after colorectal surgery. The neural network models provided greater discrimination than the models based on traditional logistic regression. These models may allow for early detection of postoperative complications as soon as postoperative day 2. See Video Abstract.

Perioperative and oncological outcomes following robotic en bloc multivisceral resection for colorectal cancer.

AIM: As multidisciplinary treatment strategies for colorectal cancer have improved, aggressive surgical resection has become commonplace. Multivisceral and extended resections offer curative-intent resection with significant survival benefit. However, limited data exist regarding the feasibility and oncological efficacy of performing extended resection via a minimally invasive approach. The aim of this study was to determine the perioperative and long-term outcomes following robotic extended resection for colorectal cancer. METHOD: We describe the population of patients undergoing robotic multivisceral resection for colorectal cancer at our single institution. We evaluated perioperative details and investigated short- and long-term outcomes, using the Kaplan-Meier method to analyse overall and recurrence-free survival. RESULTS: Among the 86 patients most tumours were T3 (47%) or T4 (47%) lesions in the rectum (78%). Most resections involved the anterior compartment (72%): bladder (n = 13), seminal vesicle/vas deferens (n = 27), ureter (n = 6), prostate (n = 15) and uterus/vagina/adnexa (n = 27). Three cases required conversion to open surgery; 10 patients had grade 3 complications. The median hospital stay was 4 days. Resections were R0 (>1 mm) in 78 and R1 (0 to ≤1 mm) in 8, with none being R2. The average nodal yield was 26 and 48 (55.8%) were pN0. Three-year overall survival was 88% and median progression-free survival was 19.4 months. Local recurrence was 6.1% and distant recurrence was 26.1% at 3 years. CONCLUSION: Performance of multivisceral and extended resection on the robotic platform allows patients the benefit of minimally invasive surgery while achieving oncologically sound resection of colorectal cancer.

Prospective Study of Perioperative Circulating Tumor DNA Dynamics in Patients Undergoing Hepatectomy for Colorectal Liver Metastases.

OBJECTIVE: To evaluate the association of perioperative ctDNA dynamics on outcomes after hepatectomy for CLM. SUMMARY BACKGROUND DATA: Prognostication is imprecise for patients undergoing hepatectomy for CLM, and ctDNA is a promising biomarker. However, clinical implications of perioperative ctDNA dynamics are not well established. METHODS: Patients underwent curative-intent hepatectomy after preoperative chemotherapy for CLM (2013-2017) with paired prehepatectomy/postoperative ctDNA analyses via plasma-only assay. Positivity was determined using a proprietary variant classifier. Primary endpoint was recurrence-free survival (RFS). Median follow-up was 55 months. RESULTS: Forty-eight patients were included. ctDNA was detected before and after surgery (ctDNA+/+) in 14 (29%), before but not after surgery (ctDNA+/-) in 19 (40%), and not at all (ctDNA-/-) in 11 (23%). Adverse tissue somatic mutations were detected in TP53 (n = 26; 54%), RAS (n = 23; 48%), SMAD4 (n = 5; 10%), FBXW7 (n = 3; 6%), and BRAF (n = 2; 4%). ctDNA+/+ was associated with worse RFS (median: ctDNA+/+, 6.0 months; ctDNA+/-, not reached; ctDNA-/-, 33.0 months; P = 0.001). Compared to ctDNA+/+, ctDNA+/- was associated with improved RFS [hazard ratio (HR) 0.24 (95% confidence interval (CI) 0.1-0.58)] and overall survival [HR 0.24 (95% CI 0.08-0.74)]. Adverse somatic mutations were not associated with survival. After adjustment for prehepatectomy chemotherapy, synchronous disease, and ≥2 CLM, ctDNA+/- and ctDNA-/- were independently associated with improved RFS compared to ctDNA+/+ (ctDNA+/-: HR 0.21, 95% CI 0.08-0.53; ctDNA-/-: HR 0.21, 95% CI 0.08-0.56). CONCLUSIONS: Perioperative ctDNA dynamics are associated with survival, identify patients with high recurrence risk, and may be used to guide treatment decisions and surveillance after hepatectomy for patients with CLM.

Insurance Disparities in Access to Robotic Surgery for Colorectal Cancer.

BACKGROUND: The use of the robotic approach is increasing for colorectal cancer operations, but the added cost of the platform has the potential to introduce challenges in its dissemination. We hypothesized that adoption of the robot is introducing new disparities in access to minimally invasive surgery (MIS) for colorectal cancer, especially across patient insurance groups. METHODS: This cross-sectional study analyzed surgical cases of stage I-III colorectal cancer from the National Cancer Database (NCDB) between 2010 and 2019. The primary outcome was surgical approach (robotic, laparoscopic, or the composite "MIS"). The predictor was a patient's primary payor. Potential confounders included sociodemographics, tumor characteristics, and the facility. Hierarchical multivariable models were generated, and sensitivity analyses were performed. RESULTS: For colorectal cancer operations, the MIS approach increased from 39% in 2010 to 73% in 2019, driven predominantly by an increase in the robotic approach from 2 to 24%. For laparoscopy, the size of the disparity between patients with Private insurance and Medicaid shrank from 11% (2010) to 4% (2019), whereas this disparity increased for the robotic approach from 1% (2010) to 5% (2019). On adjusted analysis, patients with Medicaid (odds ratio [OR] 0.86 [CI 0.79-0.95]) and the Uninsured (OR 0.67 [CI 0.56-0.79]) had lower odds of receiving a robotic operation than those with Private insurance in 2019. This disparity remained consistent across five sensitivity analyses. CONCLUSIONS: As the field of colorectal cancer surgery shifts away from laparoscopy and toward robotics, new inequities across patient insurance are emerging. Proactive efforts are needed to ensure all patients benefit from a minimally invasive approach.

Peritoneal recurrence after resection for Stage I-III colorectal cancer: A population analysis.

BACKGROUND: Colorectal cancer (CRC) often recurs in the peritoneum, although the pattern of peritoneal recurrence (PR) has received less attention. We sought to describe the presentation and risk factors for PR following CRC resection. METHODS: We performed a cohort study of patients undergoing resection of Stage I-III CRC from 2006 to 2007 using merged data from a Commission on Cancer Special Study and the National Cancer Database. We estimated the timing, method of detection, and risk factors for isolated PR. RESULTS: Here, 8991 patients were included and isolate PR occurred in 77 (0.9%) patients. The median time to PR was 16.2 months (intrquartile range = 9.3-28.0 months) and most patients were identified via new symptoms (36.4%). Pathologic factors associated with increased odds of PR included higher T stage (T3 vs. T2, odds ratio [OR] = 4.8, 95% confidence interval [CI] = 1.5-15.7), N stage (N1 vs. N0, OR = 2.00, CI = 1.1-3.7), and signet ring (OR = 8.2, CI = 3.0-22.3) or mucinous histology (OR = 2.6, CI = 1.5-4.7). CONCLUSIONS: The majority of PR was detected within 18 months and few were identified by surveillance. Advanced T/N stage and signet ring/mucinous histology were associated with increased odds of PR.

Impact of cumulative operative time on postoperative complication risk in simultaneous resections of colorectal liver metastases and primary tumors.

BACKGROUND: Simultaneous resection of colorectal liver metastases (CLM) and primary colorectal cancers (CRC) is nuanced without firm rules for selection. This study aimed to identify factors associated with morbidity after simultaneous resection. METHODS: Using a prospective database, patients undergoing simultaneous CLM-CRC resection from 1/1/2017-7/1/2020 were analyzed. Regression modeling estimated impact of colorectal resection type, Kawaguchi-Gayet (KG) hepatectomy complexity, and perioperative factors on 90-day complications. RESULTS: Overall, 120 patients underwent simultaneous CLM-CRC resection. Grade≥2 complications occurred in 38.3% (n = 46); these patients experienced longer length of stay (median LOS 7.5 vs. 4, p < 0.001) and increased readmission (39% vs. 1.4%, p < 0.001) compared to patients with zero or Grade 1 complications. Median OR time was 298 min. Patients within highest operative time quartile (>506 min) had higher grade≥2 complications (57%vs. 23%, p = 0.04) and greater than 4-fold increased odds of grade≥2 morbidity (OR 4.3, 95% CI (Confidence Interval) 1.41-13.1, p = 0.01). After adjusting for Pringle time, KG complexity and colorectal resection type, increasing operative time was associated with grade≥2 complications, especially for resections in highest quartile of operative time (OR 7.28, 95% CI 1.73-30.6, p = 0.007). CONCLUSION: In patients undergoing simultaneous CLM-CRC resection, prolonged operative time is independently associated with grade≥2 complications. Awareness of cumulative operative time may inform intraoperative decision-making by surgical teams.

What is the Risk for Peritoneal Metastases and Survival Afterwards in T4 Colon Cancers?

BACKGROUND: Patients with T4 colon adenocarcinomas have an increased risk of peritoneal metastases (PM) but the histopathologic risk factors for its development are not well-described. OBJECTIVE: The purpose of this study was to determine factors associated with PM, time to recurrence, and survival after recurrence among patients with T4 colon cancer. PATIENTS AND METHODS: Patients with pathologic T4 colon cancer who underwent curative resection from 2005 to 2017 were identified from a prospectively maintained institutional database and classified by recurrence pattern: (a) none - 68.8%; (b) peritoneal only - 7.9%; (c) peritoneal and extraperitoneal - 9.9%; and (d) extraperitoneal only - 13.2%. Associations between PM development and patient, primary tumor, and treatment factors were assessed. RESULTS: Overall, 151 patients were analyzed, with a median follow-up of 66.2 months; 27 patients (18%) developed PM (Groups B and C) and 20 (13%) patients recurred at non-peritoneal sites only (Group D). Median time to developing metastases was shorter for Groups B and C compared with Group D (B and C: 13.7 months; D: 46.7 months; p = 0.022). Tumor deposits (TDs) and nodal stage were associated with PM (p < 0.05), and TDs (p = 0.048) and LVI (p = 0.015) were associated with additional extraperitoneal recurrence. Eleven (41%) patients with PM underwent salvage surgery, and median survival after recurrence was associated with the ability to undergo cytoreduction (risk ratio 0.20, confidence interval 0.06-0.70). CONCLUSION: PM risk after resection of T4 colon cancer is independently associated with factors related to lymphatic spread, such as N stage and TDs. Well-selected patients can undergo cytoreduction with long-term survival. These findings support frequent postoperative surveillance and aggressive early intervention, including cytoreduction.

Oncologic Outcomes of Multi-Institutional Minimally Invasive Inguinal Lymph Node Dissection for Melanoma Compared with Open Inguinal Dissection in the Second Multicenter Selective Lymphadenectomy Trial (MSLT-II).

BACKGROUND: Minimally invasive inguinal lymphadenectomy (MILND) is safe and feasible, but limited data exist regarding oncologic outcomes. METHODS: This study performed a multi-institutional retrospective cohort analysis of consecutive MILND performed for melanoma between January 2009 and June 2016. The open ILND (OILND) comparative cohort comprised patients enrolled in the second Multicenter Selective Lymphadenectomy Trial (MSLT-II) between December 2004 and March 2014.The pre-defined primary end point was the same-basin regional nodal recurrence, calculated using properties of binomial distribution. Time to events was calculated using the Kaplan-Meier method. The secondary end points were overall survival, progression-free survival, melanoma-specific survival (MSS), and distant metastasis-free survival (DMFS). RESULTS: For all the patients undergoing MILND, the same-basin regional recurrence rate was 4.4 % (10/228; 95 % confidence interval [CI], 2.1-7.9 %): 8.2 % (4/49) for clinical nodal disease and 3.4 % (6/179) for patients with a positive sentinel lymph node (SLN) as the indication. For the 288 patients enrolled in MSLT-II who underwent OILND for a positive SLN, 17 (5.9 %) had regional node recurrence as their first event. After controlling for ulceration, positive LN count and positive non-SLNs at the time of lymphadenectomy, no difference in OS, PFS, MSS or DMFS was observed for patients with a positive SLN who underwent MILND versus OILND. CONCLUSION: This large multi-institutional experience supports the oncologic safety of MILND for melanoma. The outcomes in this large multi-institutional experience of MILND compared favorably with those for an OILND population during similar periods, supporting the oncologic safety of MILND for melanoma.

Surgical Outcomes in Cancer Patients Undergoing Elective Surgery After Recovering from Mild-to-Moderate SARS-CoV-2 Infection.

BACKGROUND: An increasing number of patients with cancer diagnoses and prior SARS-CoV-2 infection will require surgical treatment. The objective of this study was to determine whether a history of SARS-CoV-2 infection increases the risk of adverse postoperative events following surgery in patients with cancer. METHODS: This was a propensity-matched cohort study from April 6, 2020 to October 31, 2020 at the UT MD Anderson Cancer Center. Cancer patients were identified who underwent elective surgery after recovering from SARS-CoV-2 infection and matched to controls based on patient, disease, and surgical factors. Primary study outcome was a composite of the following adverse postoperative events that occurred within 30 days of surgery: death, unplanned readmission, pneumonia, cardiac injury, or thromboembolic event. RESULTS: A total of 5682 patients were included for study, and 114 (2.0%) had a prior SARS-CoV-2 infection. The average time from infection to surgery was 52 (range 20-202) days. Compared with matched controls, there was no difference in the rate of adverse postoperative outcome (14.3% vs. 13.4%, p = 1.0). Patients with a SARS-CoV-2-related inpatient admission before surgery had increased odds of postoperative complication (adjusted odds ratio [aOR] 7.4 [1.6-34.3], p = 0.01). CONCLUSIONS: A minimal wait time of 20 days after recovering from minimally symptomatic SARS-CoV-2 infection appears to be safe for cancer patients undergoing low-risk elective surgery. Patients with SARS-CoV-2 infections requiring inpatient treatment were at increased risk for adverse events after surgery. Additional wait time may be required in those with more severe infections.

New Technologies to Prevent Anastomotic Leak.

Leaks from anastomoses can be a serious complication of any gastrointestinal resection. Leaks lead to increased morbidity, delayed postoperative recovery, and potential delays in adjuvant treatment in cancer cases. Prevention of anastomotic leak has been an area of ongoing research for decades. Methods of assessing bowel perfusion have been developed that may provide forewarning of anastomotic compromise. Physical reinforcement of the anastomosis with buttressing material is an available method employed with the goal of preventing leaks. Liquid-based sealants have also been explored. Lastly, interactions between the gut microbiome and anastomotic healing have been investigated as a mean of manipulating the microenvironment to reduce leak rates. Though no single technology has been successful in eliminating leaks, an understanding of these developing fields will be important for all surgeons who operate on the gastrointestinal tract.

Facilities that service economically advantaged neighborhoods perform surgical metastasectomy more often for patients with colorectal liver metastases.

BACKGROUND: Metastasectomy of isolated colorectal liver metastases (CRLM) requires significant clinical expertise and may not be readily available or offered. The authors hypothesized that hospitals that treat a greater percentage of patients from higher income catchment areas are more likely to perform metastasectomies regardless of patient or tumor characteristics. METHODS: Using the National Cancer Data Base, the authors classified facilities into facility income quartiles (FIQs) based on the percentage of patients from the wealthiest neighborhoods (by zip code). Quartile 1 included facilities with <2.1% of the patients residing within the highest income zip codes, quartile 2 included facilities with 2.2% to 15.6% of patients residing within the highest income zip codes, quartile 3 included facilities with 15.7% to 40.2% of patients residing within the highest income zip codes, and quartile 4 included facilities with 40.3% to 90.5% of patients residing within the highest income ZIP codes. Patient, tumor, and facility characteristics were analyzed using a multivariate logistic regression to identify associations between metastasectomy and FIQ. RESULTS: Patients with CRLM were more likely to undergo metastasectomy at facilities in the highest FIQ compared with the lowest FIQ (18% vs 11% in FIQ4; P = .001). This trend was not observed in the resection of primary tumors for nonmetastatic CRLM (rates of 95% vs 93%; P = .94). After adjusting for individual insurance status, distance traveled, zip code-level individual income, tumor, and host, patients who were treated at the highest FIQ facilities were found to be more likely to undergo metastasectomy (odds ratio, 1.29; 95% CI, 1.02-1.72 [P = .03]). CONCLUSIONS: Metastasectomy for CRLM is more likely to occur at facilities that serve a greater percentage of patients from high-income catchment areas, regardless of individual patient characteristics. This disparity uniquely affects those patients with advanced cancers for which specialized expertise for therapy is necessary.

Regional Node Basin Recurrence in Melanoma Patients: More Common After Node Dissection for Macroscopic Rather than Clinically Occult Nodal Disease.

BACKGROUND: Recommended treatment for patients with sentinel lymph node (SLN)-positive melanoma has recently changed. Randomized trials demonstrated equivalent survival with close observation versus completion lymph node dissection (CLND), but increased regional node recurrence. We evaluated factors related to in-basin nodal recurrence after lymphadenectomy (LND) for SLN-positive or macroscopic nodal metastases. METHODS: An institutional database and the first Multicenter Selective Lymphadenectomy Trial (MSLT-I) were analyzed independently. Exclusions were multiple primaries, multi-basin involvement, or in-transit metastases. Patient demographics, primary tumor thickness and ulceration, lymph nodes retrieved, and use of adjuvant radiotherapy were analyzed. Multivariate analyses were performed to determine factors predicting in-basin nodal recurrence (significance p ≤ 0.05). RESULTS: The retrospective cohort (577 patients) showed an in-basin failure rate of 6.6% after CLND for a positive SLN and 13.1% after LND for palpable disease (p = 0.001). This recurrence risk persisted after adjustment for patient, tumor, and LND factors [hazard ratio (HR) 2.32; p = 0.004]. In the MSLT-I cohort (326 patients), the failure rate after CLND following SLNB was 6.2%, but 10.1% after LND for palpable recurrence in observation patients. After adjustment for other factors, macroscopic disease was associated with an increased risk of recurrence after LND (HR 2.24; p = 0.05). CONCLUSION: After LND for melanoma, in-basin recurrence is infrequent, but a clinically significant fraction will fail. Failure is less likely if dissection is performed for clinically occult disease. Further research is warranted to evaluate the long-term regional control and quality of life associated with nodal basin observation, which has now become standard practice.

Inaccurate pretreatment staging can impact survival in early stage esophageal adenocarcinoma.

BACKGROUND: Given the survival advantage of neoadjuvant treatment for locally advanced esophageal cancer, accurate clinical staging is necessary. The aim of this study was to assess the clinical (c) and pathologic (p) staging concordance rates for presumably early stage esophageal adenocarcinoma patients that had upfront esophagectomy (UFE) and evaluate if survival (OS) was negatively affected by inaccurate preoperative staging and subsequent treatment selection. METHODS: An NCDB retrospective review of nonmetastatic esophageal adenocarcinoma patients that had UFE. The rates of concordance between c and p staging system and OS were calculated. RESULTS: Of 2775 patients, most patients presented with cN0 (82.8%) and cT1 tumors (53.6%). The overall concordance between c and p staging was 78.8% for T-classification (moderate agreement; weighted κ = 0.729; P < .001) and 78.8% for N-classification (weak agreement; weighted κ = 0.448; P < .001). Patients that were upstaged due to a lack of concordance between T-classification had decreased 5- and 10-year OS (30% and 16%, P < .001) and those upstaged due to discordant N-classification had decreased 5- and 10-year OS (28% and 23%, P < .001)." CONCLUSIONS: Preoperative staging of esophageal adenocarcinoma has moderate reliability and accuracy for predicting pT and pN classification. Up to 25% of patients have discordant clinical and pathological staging, which impacts OS.

Duodenal GI stromal tumors: Is radical resection necessary?

BACKGROUND AND OBJECTIVES: Duodenal gastrointestinal stromal tumors (GISTs) are rare tumors that pose a surgical challenge, and long-term outcomes after resection have not been detailed outside of small case series. This study uses the National Cancer Database (NCDB) to examine the determinants of radical resection for duodenal GISTs as well as the impact of local vs radical resection on overall survival (OS). METHODS: The NCDB was queried for nonmetastatic duodenal GISTs from 2004 to 2014. Predictors of radical resection were determined using multivariate logistic regression stratified by extent of tumor involvement. Factors associated with OS were identified with Cox proportional regression analysis. RESULTS: Treatment at an academic center, size >5 cm, and extra-duodenal extension were associated with radical resection. On multivariate analysis, radical resection was associated with decreased OS (HR, 1.93; P < .03). Systemic therapy, extra-duodenal extension, grade, stage, mitoses, and receipt of systemic therapy did not impact OS. CONCLUSION: Local resection of duodenal GISTs is associated with improved OS compared to radical resection after controlling for tumor factors and systemic treatment. Traditional indicators of tumor aggressiveness were associated with radical resection, but not OS. When feasible, local resection should be considered for resection of duodenal GISTs.

Can high-volume teams of anesthesiologists and surgeons decrease perioperative costs for pancreatic surgery?

BACKGROUND: Pancreatic surgery outcomes are associated with surgeon and center experience. Anesthesiologists as potential value drivers for pancreatic surgery have not been explored. We sought to evaluate whether anesthesiologists impact perioperative costs for pancreatic surgery. METHODS: Within an integrated health care system, 796 pancreatic surgeries (526 PDs and 270 DPs) were performed from January 2014 to June 2017. Mean direct operative and anesthesia costs driven by anesthesiologists (operating room (OR) time, anesthesia billing and anesthesia procedures) were determined for each case. The volumes of pancreatic cases per anesthesiologist were calculated, and those above the 75th percentile for volume (4 cases) were considered high-volume. A multivariable analysis of OR/anesthesia costs was performed. RESULTS: Mean OR and anesthesia costs for PD were $7064 for low-volume anesthesiologists (LVA), higher than $5968 for high-volume anesthesiologists (HVA) (p < 0.001). By multivariable analysis, HVA were associated with decreased costs of $2278 (p < 0.001). Teams of HVA and high-volume surgeons (HVS) were also associated with decreased mean costs of $1790 (p = 0.04). CONCLUSION: These data suggest that anesthesiologists experienced in the management of complex pancreatic operations such as PDs may contribute to improved efficiencies in care by reducing perioperative costs.

In Vivo Delivery and Therapeutic Effects of a MicroRNA on Colorectal Liver Metastases.

Multiple therapeutic agents are typically used in concert to effectively control metastatic tumors. Recently, we described microRNAs that are associated with the oligometastatic state, in which a limited number of metastatic tumors progress to more favorable outcomes. Here, we report the effective delivery of an oligometastatic microRNA (miR-655-3p) to colorectal liver metastases using nanoscale coordination polymers (NCPs). The NCPs demonstrated a targeted and prolonged distribution of microRNAs to metastatic liver tumors. Tumor-targeted microRNA miR-655-3p suppressed tumor growth when co-delivered with oxaliplatin, suggesting additive or synergistic interactions between microRNAs and platinum drugs. This is the first known example of systemically administered nanoparticles delivering an oligometastatic microRNA to advanced metastatic liver tumors and demonstrating tumor-suppressive effects. Our results suggest a potential therapeutic strategy for metastatic liver disease by the co-delivery of microRNAs and conventional cytotoxic agents using tumor-specific NCPs.