49.01 Robotic Natural orifice IntraCorporeal anastomosis and transrectal Extraction (NICE) procedure

Posted on January 31, 2019

R. O. Minjares-Granillo1, B. Dimas1, J. P. LeFave1,2, E. M. Haas1,2  1University of Texas Medical School at Houston,Department Of Surgery, Division Of Minimally Invasive Colon And Rectal Surgery,Houston, TEXAS, USA 2Houston Methodist Hospital,Division Of Colon And Rectal Surgery,Houston, TEXAS, USA

Introduction: Numerous studies have confirmed significant benefits of intracorporeal anastomosis (ICA) following colorectal procedures however technical challenges have limited this approach following conventional laparoscopic surgery.

The robotic Xi platform serves as an enabling technology and has resulted in a surge of reports for right-sided intracorporeal anastomosis, however, there are no reports involving more complex left-sided procedures such as for diverticulitis. Furthermore, there are no reports of natural orifice assisted techniques using robotic Xi in which the specimen can be removed and the anvil can be placed thereby completely eliminating the need for an abdominal wall incision other than the port sites. 

We present a pilot study to investigate the safety, feasibility and short term outcomes of robotic Natural orifice-assisted IntraCorporeal anastomosis with transrectal Extraction of specimen, called the robotic NICE procedure.

Methods:  Consecutive patients presenting for elective resection for diverticulitis with formation of a colorectal anastomosis were entered into an IRB database.  All patients underwent the robotic NICE procedure.  Demographic data, intraoperative data and outcomes data were assessed and analyzed.  

Results: Ten patients (5 male and 5 female) underwent resection. The mean age, ASA and BMI was 56 (range 43-66), II (I-III) and 29 (21-35).  All procedures were successfully completed including transrectal extraction of the specimen and formation of an ICA.  The mean operative time was 198 min (146–338) and mean EBL was 35 ml (15 –50). Mean time to first flatus was 16 hours (10-22) and mean length of stay was 1.9 days (1.6 – 2.6).  There were no intraoperative or post-operative complications.  There were no unexpected ICU stay, reoperation or readmission. 

Conclusion:  Colorectal left-sided resections such as for diverticulitis can be safely accomplished using natural-orifice assisted extraction of the specimen as well as complete intracorporeal anastomosis in this pilot study.  The NICE procedure resulted in early return of bowel function, short length of stay and low complications. The complete elimination of abdominal wall incision likely accounts for these findings and larger cohorts of patients are to be investigated to explore this promising approach afforded by robotic technology.

44.20 Cartilage Oligomeric Matrix Protein (COMP): A Potential Biomarker in Early Onset Colon Cancer.

Posted on January 31, 2019

N. P. Omesiete1, J. Jandova1, K. Memeh1, V. Nfonsam1  1University of Arizona,Surgery,Tucson, AZ, USA 2University of Arizona,Surgery,Tucson, AZ, USA

Introduction:
There has been a steady rise in the incidence of early onset colon cancer (EOCC); age <50. Recent studies suggest that EOCC may be a biologically distinct disease from late onset CC (LOCC). Our previous study showed COMP is upregulated in EOCC compared to LOCC patients and its elevation is associated with tumor aggressiveness and poor survival. The aim of this study was to evaluate COMP as a potential plasma biomarker and to assess its correlation with carcinoembryonic antigen (CEA) level in patients with EOCC.

Methods:

Fresh frozen plasma samples were obtained from our Colorectal biorepository belonging to 16 patients with early and late onset CC (8 patients in each cohort). The samples were matched for stage of disease. An ELISA assay using Human COMP Quantikine ELISA Kit purchased from R&D Systems was performed using 50 ul of 100X diluted plasma sample according to the manufacturer’s protocol. COMP was detected in all the samples of patients with colon cancer.  A quantitative analysis was performed to determine the levels of COMP in each sample by normalizing the COMP protein to total protein. This was accomplished using A Pierce BCA protein assay kit from Thermo scientific. Analysis was performed to compare the levels of COMP between both groups and their CEA levels pre-treatment.

Results:

There were a total of 16 patients (8 males and 8 females). Mean age was 42 years for EOCC and 70 years for LOCC. The patients were propensity matched for stages. There was 1 stage I; 2 stage II; 3 stage III and 2 stage IV in each cohort. COMP was detected in all 16 serum samples. Mean COMP levels was 140 pg of COMP/ug of total protein in EOCC and 20 pg of COMP/ug of total protein in LOCC, indicating a seven fold difference between the cohorts, p <0.005. There was also a positive correlation between COMP and the pre-treatment CEA levels for each stage of disease in each cohort. This was however not statistically significant. 

Conclusion:
Our findings suggest that COMP is differentially and significantly elevated in EOCC with good correlation with an established biomarker CEA. COMP may be useful as a biomarker in EOCC.

44.19 Anti-Claudin-1 Conjugated to a Near Infrared Fluorophore Targets Colon Cancer in Nude Mouse Models

Posted on January 31, 2019

H. M. Hollandsworth1,2,5, T. M. Lwin1,2,5, S. Amirfakhri1,2,5, F. Filemoni1,2,5, D. Stupack2, S. K. Batra3, R. M. Hoffman1,2,4,5, P. Dhawan3, M. Bouvet1,2,5  1University Of California – San Diego,Department Of Surgery,San Diego, CA, USA 2University Of California – San Diego,Moores Cancer Center,San Diego, CA, USA 3University of Nebraska Medical Center,Department Of Biochemistry,Omaha, NE, USA 4AntiCancer, Inc.,San Diego, CA, USA 5VA San Diego Healthcare System,Surgical Services,San Diego, CA, USA

Introduction:
Colorectal cancer remains one of the most prevalent cancers in the United States and is the third leading cause of cancer related death. Claudins are tight junction proteins which maintain an epithelial barrier in normal colon cells. Overexpression of Claudin-1 has been implicated in the development of colon cancer. Tumor cells express a significantly higher amount of Claudin when compared with normal colonic mucosa.   We postulated that Claudin-1 may be a useful target in near infrared imaging and fluorescence guided surgery for colorectal cancers.

Methods:
We conjugated Claudin-1 antibody to LI-COR IR800DyeCW (Claudin-1-IRDye800CW). Western blotting of 9 different human colon cancer lysates was performed with Claudin-1-IRDye800CW. Animal imaging was initially performed with LI-COR Pearl Trilogy imaging system on subcutaneous and orthotopic colon tumors with 75 mcg Claudin-1-IRDye800CW 72 hours after injection. A dose-response study was then completed on subcutaneous cell line models. Subcutaneous implantation of LS174T on the bilateral flanks of nude mice was performed. Three groups of mice were administered increasing doses of Claudin-1-IRDye800CW: 12.5, 25, and 50 micrograms reconstituted in 100 microliters PBS, via tail vein injection. 3 mice were used as controls (no treatment, antibody alone, and 1 dye alone). In vivo imaging was performed at 24, 48, and 72 hours after administration of the conjugated dye. The mice were then euthanized and laparotomy was performed to assess for enhancement of internal organs.

Results:
Western blotting revealed that 9 out of 10 colon cancer xenografts expressed varying amounts of Claudin-1.  All tumors demonstrated strong and specific fluorescence labeling at 800 nm wavelength, even with the lowest dose of 12.5 micrograms. A representative image of mouse with an orthotopic LS174T colon tumor treated with 75 mcg of Claudin-1-IRDye800CW is shown in the Figure below. The control mice that did not receive treatment and received Claudin-1 antibody alone did not have any signal on the colon or tumor. The mouse that received IRDye800CW alone had diffuse signal that did not localize to tumors.

Conclusion:
Claudin-1 is a useful target for near infrared antibody-based imaging for visualization of colorectal tumors for future use in fluorescence-guided surgery.  
 

44.17 Intestinal Alkaline Phosphatase Protects Against Radiation Induced Gut Barrier Dysfunction

Posted on January 31, 2019

P. Cavallaro1, F. Adiliaghdam1, Y. Liu1, M. Kaleko1, C. Furlan Freguia1, R. Hodin1  1Massachusetts General Hospital,General Surgery,Boston, MA, USA

Introduction: Radiation injury induces gut barrier dysfunction and local intestinal inflammation, a clinical entity known as radiation enteritis/colitis. The brush border enzyme intestinal alkaline phosphatase (IAP) has been shown to maintain the gut mucosal barrier and attenuate local and systemic inflammation in multiple mouse models of colitis. We wanted to determine if supplemental IAP can prevent radiation induced gut barrier dysfunction and local inflammation, and therefore be a potential therapy for radiation enteritis/colitis.

 

Methods: Adult WT C57BL/6J mice were subjected to whole body irradiation (IR) to a total of 850 or 1400 rads. Mice were administered either 100 U/mL IAP or vehicle in their drinking water starting 4 days prior to IR injury and then continued until mice were sacrificed 4 days after injury. Control “sham” mice received no IR injury. Gut barrier function, tissue and systemic inflammation were measured.

 

Results:There were no difference in food and water intake among any of the groups. Gut barrier function was first measured by FITC-dextran flux from intestinal lumen to systemic blood. Vehicle treated IR mice had a radiation dose dependent increase in FITC flux across the gut barrier compared to sham (10-fold increase in 850 rad group, 30-fold increase in 1400 rad group). Permeability to FITC was almost completely attenuated in IAP treated mice in both groups (p < 0.001). Quantitative PCR of tight junction proteins demonstrated a significant decrease in ileal ZO1, ZO3, and occludin that was partially restored by IAP supplementation in both IR groups. Quantitative PCR also showed a significant decrease in colonic ZO1, ZO3, and occludin, again partially restored by IAP. Similarly, Western blot analysis showed a significant decrease in TJPs in IR treated mice, restored with IAP therapy. Next, local inflammation was assessed by measuring cytokine expression. Relative ileal and colonic TNF-α expression was increased 10-fold in the 850 rad group and 30-fold in the 1400 rad group compared to sham mice and was decreased by 50-70% when treated with IAP (p <0.001). Systemic inflammation was measured by serum ELISA which showed a two-fold increase in TNF-α and IL-6. Again, this response was attenuated by IAP. Interestingly, there was no difference in serum LPS between groups.

 

Conclusion:Radiation-induced gut barrier dysfunction and both local and systemic inflammation can be attenuated with supplemental IAP. This may be a novel approach to the treatment and prevention of radiation enteritis/colitis.

44.15 Genetic sub-clones in rectal cancer respond differentially to neoadjuvant therapy

Posted on January 31, 2019

L. Frydrych1, L. H. Maguire2, P. Ulintz3, A. Bankhead4,8, J. K. Greenson5, C. J. Sifuentes3, E. Fearon6,7, K. M. Hardiman2  1University Of Michigan,Department of Surgery,Ann Arbor, MI, USA 2University Of Michigan,Colorectal Surgery,Ann Arbor, MI, USA 3University Of Michigan,Bioinformatics Core,Ann Arbor, MI, USA 4University Of Michigan,Biostatistics,Ann Arbor, MI, USA 5University Of Michigan,Pathology,Ann Arbor, MI, USA 6University Of Michigan,Internal Medicine,Ann Arbor, MI, USA 7University Of Michigan,Human Genetics,Ann Arbor, MI, USA 8University Of Michigan,Computational Medicine And Bioinformatics,Ann Arbor, MI, USA

Introduction:  Recommendations for treatment of locally advanced rectal cancer include chemotherapy, radiation and surgery. Response to neo-adjuvant therapy is variable. We have previously shown rectal cancers are made up of multiple genetically distinct sub-clones.  Unique sub-clones within primary tumors may harbor mutations which contribute to treatment resistance, relapse, and inter-patient variations in response to standard-of-care neo-adjuvant therapy. Analysis of the influence of neoadjuvant therapy on the molecular evolution of rectal cancer may provide insight about mechanisms of resistance and highlight new therapeutic approaches for patients.

Methods: Rectal cancer patients with an indication for neo-adjuvant chemoradiotherapy were identified at a tertiary referral center. Primary tumor biopsies from multiple discrete geographic locations were obtained prior to treatment. At the time of surgical intervention after standard-of-care chemoradiotherapy, tissue from the treated tumor was obtained and analyzed. Pre- and post- treatment specimens were subjected to whole exome sequencing followed by confirmatory deep sequencing to define somatic mutations. Copy number variation was assessed in all samples using Oncoscan SNP arrays. Genomic data were analyzed using Pyclone to identify sub-clonal tumor populations that differed in frequency after neo-adjuvant chemoradiotherapy. Recurrent drivers of resistance were identified in the sub-clones across tumors. Using Hotnet2, pathway analysis was performed on integrated resistant gene mutation and copy number alteration data.

Results: 32 samples were obtained from 10 patients. Pyclone identified 2-9 individual subclonal populations per tumor. Neoadjuvant therapy resulted in substantial change in the relative proportions of individual sub-clones within the primary tumor. Resistant sub-clones recurrently (>30%) contained mutations in TP53, APC, ABCA13, ITIH5, MUC16, PTEN, THSD4, and TNS1. Recurrent copy number variations for selected chromosome regions were seen in cancers after therapy. Pathway analysis revealed significantly altered pathways in resistant tumor specimens associated with RNA splicing and processing, regulation of transcription, APC-mediated pathways, mTOR signaling, fatty acid biosynthesis, and histone modification.

Conclusion: Intra-tumoral heterogeneity is evident in pre-treatment rectal cancer and sub-clonal populations are selectively modified by treatment. Resistant sub-clones demonstrate high frequencies of somatic mutation in multiple known tumorigenesis driver genes, and intra-tumoral heterogeneity persists post-treatment. Our analyses reveal complex and dynamic genomic architectures in pre- and post-treatment rectal cancers. These data indicate that novel treatment strategies must take into account a changing and heterogeneous tumor mutational profile when attempting to target rectal cancers.
 

44.14 Penicillin Prevents Rat Colonic Ischemia, Validating its Use in Ischemic Gastrointestinal Disease

Posted on January 31, 2019

T. M. Gisinger1,2, V. M. Baratta2, M. Barahona2, J. Ollodart2, D. Mulligan2, J. P. Geibel2,3  1Paracelsus Medical University,Department Of Medicine,Salzburg, SALZBURG, Austria 2Yale University School of Medicine,Department Of Surgery,New Haven, CT, USA 3Yale University School of Medicine,Department Of Cellular And Molecular Physiology,New Haven, CT, USA

Introduction: Ischemic colitis (IC) is the most common type of intestinal ischemia and arises when the colonic blood supply does not meet cellular metabolic demands. Though clinical evidence is lacking, many patients with IC are nonoperatively managed with empiric antibiotics. It has been proposed that antibiotics mitigate ischemia by reducing bacterial translocation and preventing breakdown of the epithelial barrier. In this study, we demonstrate that colonic tissue perfused with Penicillin G is more resilient to ischemic injury than tissues not exposed to the drug. These findings suggest a new clinical management paradigm of preventing ischemic conditions of the gastrointestinal tract.

Methods: Colon segments from rats were obtained and perfused with an ex-vivo intestinal perfusion device. The perfusion device consists of concentric chambers that contain the bowel segments perfused at 37°C. FITC-Inulin, fluorescein isothiocyanate, was used to assess the ischemic conditions of the intestinal grafts in real-time; a drop in fluorescence (FITC-Inulin concentration) is indicative of cellular ischemic injury. Intestinal segments were perfused with 4-(2-hydroxyethyl)-1-piperazineethanesulfonic acid, HEPES-Ringer. To create an ischemic environment, the HEPES-Ringer was pre-saturated with 100% N2 and perfused on extraluminal surface of all rat colonic segments. The intraluminal components of experimental colons were perfused with 5 mM Penicillin G, whereas control segments were not.  

Results: Control (without Penicillin G) distal colon samples showed a significant decrease in FITC-inulin fluorescence compared with experimental (with Penicillin G) distal colons, (26.98 ±  5.035 μM FITC vs 43.62 ± 1.569 μM FITC, respectively p 0.0083, Figure 1). This indicates that Penicillin G minimizes colonic fluid secretion, which is a marker for cell death. A similar trend was seen with proximal colon rat segments (42.7 ± 1.984 μM vs. 33.28 ± 3.455 μM FITC, p 0.0356).

Conclusion: Patients with ischemic colitis are often clinically treated with antibiotics, though the pathophysiological basis of their use is not well-proven. Our study shows that Penicillin G exposure prolongs colonic viability under ischemic conditions. This result will help further guide clinical management of ischemia in the gastrointestinal tract. Further investigation of the precise mechanism by which Penicillin G mitigates ischemia needs to be conducted.

 

44.12 Penicillin’s Protective Effect on Colonic Ischemia is Mediated by H,KATPase

Posted on January 31, 2019

T. M. Gisinger1,2, V. M. Baratta1, M. J. Barahona1, J. Ollodart1, D. Mulligan1, J. P. Geibel1,3  1Yale University School Of Medicine,Department of Surgery,New Haven, CT, USA 2Paracelsus Medical University,Department of Medicine,Salzburg, SALZBURG, Austria 3Yale University School Of Medicine,Department of Cellular and Molecular Physiology,New Haven, CT, USA

Introduction: Ischemic colitis is one of the most common types of intestinal ischemia. Currently, many patients with ischemic colitis are treated with empiric antibiotics, even though the mechanism of action is not fully understood. Previously, we established that Penicillin G has a protective effect from ischemia in the rat colon. In this study, we demonstrate that the protective effect is mediated through stimulation of the colonic H,KATPase, independent of the Nitric Oxide (NO) pathway.

Methods:  The colonic segments were harvested from Sprague Dawley male rats and perfused with an ex-vivo intestinal perfusion device. Each colon was maintained at 37°C and perfused both from the luminal and basolateral side. FITC-Inulin, fluorescein isothiocyanate, was used to assess the ischemic conditions of the colonic grafts in real-time. Colonic segments were perfused with 4-(2-hydroxyethyl)-1-piperazineethanesulfonic acid, HEPES-Ringer solution. To create an ischemic environment, HEPES-Ringer was pre-saturated with 100% N2 and exposed to the extraluminal components of all colonic segments. For the experimental colonic tissues, the intraluminal compartments were perfused with 5 mM Penicillin G and 10 μM SCH-28080, a known colonic H,KATPase inhibitor. The intraluminal components of the control group were exposed to 5 mM Penicillin G. To test the NO-dependent mechanism, we used L-NAME, N(ω)-nitro-L-arginine methyl ester, a NO synthesis inhibitor. The intraluminal compartments of the experimental tissue were exposed to 30 μM L-NAME with 5 mM Penicillin G, while control tissues were exposed to 5 mM Penicillin G.

Results: The colon samples exposed to Penicillin G and SCH-28080 exhibited a significant decrease in FITC-Inulin fluorescence, compared with the control colonic tissue exposed to Penicillin G, (36.39 ± 2.721 μM FITC-Inulin vs 43.62 ± 1.569 μM FITC-Inulin, respectively, p 0.0401, Figure 1). We observed no statistically significant difference in the FITC-Inulin concentration between tissues exposed to L-NAME with Penicillin G versus tissues exposed to only Penicillin G.

Conclusion: Our study unveils the mechanism of Penicillin G’s protective effect from ischemia. Our results indicate that Penicillin G’s protective effect against ischemia acts by stimulating the colonic H,KATPase and is not NO-dependent. Therefore, Penicillin G not only has its well-known antimicrobial properties, but also appears to modulate a transport protein on the colonic cell membrane. A better understanding of Penicillin G’s effects on colonic tissue may help further guide the clinical management of ischemia in the gastrointestinal tract.

 

44.09 Mechanisms mediating stress-induced vulnerability to gastrointestinal inflammation

Posted on January 31, 2019

B. Vickers1, C. Graham2, A. Chakraborti2, A. Moon2, J. Bibb2, G. Kennedy2  1Rhodes College,Memphis, TN, USA 2University Of Alabama at Birmingham,Gastrointestinal Surgery,Birmingham, Alabama, USA

Introduction:  Inflammatory bowel disease (IBD), including ulcerative colitis and Crohn's disease, is a chronic and relapsing inflammatory disorder of the intestine. Approximately 1 million Americans are currently diagnosed with IBD and as many as 70,000 new cases are diagnosed each year. One of the main factors contributing to IBD is stress, which has become a rampant problem in America and is considered a high-ranking health concern. Unfortunately, the relationship between IBD and stress has not been thoroughly investigated and the contributions of stress to IBD pathology are not well understood. We hypothesize that stress decreases susceptibility to intestinal inflammation.

Methods:  To better understand the pathways that connect stress and IBD, C57Bl/6 mice were administered a Chronic Unpredictable Stress (CUS) regimen followed by 7 consecutive days of  a subthreshold dose of  Dextran Sodium Sulfate (DSS), a chemical inducer of colitis. After completion of CUS +/- DSS, animals were sacrificed, fecal samples were collected, and RNA was isolated from the proximal colon.  

Results: To assess the effects of CUS and/or DSS on colon inflammation, an Enzyme-Linked Immunosorbent Assay (ELISA) was performed to quantify Lipocalin-2 (LCN-2) protein levels in fecal samples. We found that the LCN-2 levels in the CUS + DSS mice were significantly higher than control. Additionally, Quantitative Real Time Polymerase Chain Reaction (qRT-PCR) was used to quantify mRNA transcript levels of three pro-inflammatory cytokines (IL-1β, IL-6, TNFα) in the proximal colon. Interestingly, CUS + DSS mice showed a significant increase in TNFα over control or either treatment alone.  

Conclusion: We found that CUS and DSS alone failed to induce inflammation, but the combination of CUS and DSS showed a significant increase in colon inflammatory mediators suggesting that chronic stress may lower gut inflammatory threshold thereby increasing susceptibility to colitis.  In the future, we plan to assess CUS in an IL10-/- colitis model as well as in the context of high fat/high carbohydrate diet. 

44.08 Increased expression of long Non-coding RNA H19 is Associated with Colon Adenocarcinoma Recurrence

Posted on January 31, 2019

S. J. O’Brien1, C. Fiechter1, M. Paas1, A. Rochet1, S. Galandiuk1  1University Of Louisville,Price Institute Of Surgical Research, The Hiram C. Polk Jr. M.D. Department Of Surgery,Louisville, KY, USA

Introduction:

Colorectal adenocarcinoma is the fourth leading cause of cancer-related death in the United States. Non-coding RNAs have recently been identified as critical mediators of tumor biology. Long non-coding RNAs (lncRNAs) are diverse in their mechanisms but are known mediators of tumor progression; H19 is a well characterized lncRNA involved in the regulation of P53 and in cancer progression. The aim of this study was to identify the association of tumor H19 expression with recurrence-free and overall survival in a colon cancer data set.

Methods:

The clinical dataset from The Cancer Genome Atlas colon adenocarcinoma data set was downloaded using FirebrowseR. The normalized expression of H19 from the associated RNA-seq data set was downloaded using cBioportal. Univariable and multivariable cox proportional regression analysis were used to identify an association between H19 expression in cancer tissue at the time of resection and recurrence-free, and overall survival. 

Results:

Four hundred and eighteen patients were included in this study. Median age was 69 years (IQR 58-75) Two hundred and nineteen patients (52%) were men. Most tumors were located in the sigmoid colon (135/418- 32%).  Two hundred and thirty-nine patients (57%) had stage 1 or 2 cancers. Lymphatic invasion was present in 36% patients (152/418). The median expression of H19 in the data set defined high or low expression groups. The only difference between groups was that high H19 expression was associated with stage 3 and 4 disease (p=0.048). There was no difference in the overall survival between the low and high H19 groups (Log Rank=0.481). High H19 expression was associated with reduced recurrence-free survival (Log-Rank=0.007) (Figure 1). On univariable regression analysis, high H19 expression, stage 3 or 4 disease, and lymphatic invasion were associated with disease recurrence (Hazard ratio=1.861, 95%CI:1.181-2.932, p=0.007, HR=2.498, 95%CI: 1.622-3.847, P<0.001, and HR= 1.928, 95%CI: 1.233-3.014, p=0.004 respectively). On multivariable regression analysis, only high H19 expression (HR=1.686, 95%CI: 1.046-2.720, p=0.032) and stage 3 or 4 disease (HR=2.888, 95%CI: 1.317-3.976, P=0.003) remained statistically significant predictors of disease recurrence.

Conclusion: 

H19 was associated with advanced stage of tumor disease and is a significant predictor of recurrent cancer on multivariable analysis. The results of this study are in keeping with in vitro studies in that H19 has a number of oncogenic mechanisms of action, including increased proliferation and mediation of epithelial-mesenchymal transition. As it is a critical molecule in cell regulation, it may have both prognostic and therapeutic uses in the future.

 

44.04 NOD2 polymorphism is associated with stricutring phentotype in Crohn's disease

Posted on January 31, 2019

J. Hallion1, S. O’Brien1, C. Fiechter1, M. B. Ekman1, J. Burton1, M. Eichenberger1, S. Galandiuk1  1Price Institute of Surgical Research,University Of Louisville,Louisville, KENTUCKY, USA

Introduction: Crohn’s disease is a common inflammatory disorder of the gastrointestinal tract. It has a multifactorial etiology with immunological, environmental, and genetic factors. Phenotypically, Crohn’s disease was classified (Montreal Classification) using age of onset, disease location, and disease behavior. Single nucleotide polymorphisms (SNPs) are common single base pair genetic variants between individuals and are associated with disease phenotype in a number of diseases. Recent genome wide exploratory studies have identified SNPs that are associated with a stricturing phenotype in Crohn’s disease. The aim of this study was to determine if SNP allele frequencies truly correlate with stricturing Crohn’s disease phenotype in a mid-western Caucasian United States population.

 

Methods:  Patients with Crohn’s disease were selected from a prospectively maintained university surgical digestive practice database. Blood samples were drawn during clinic appointments. Patients with stricturing (Montreal B2) and non-stricturing (Montreal B1) phenotypes were eligible for inclusion. Clinical data were extracted from an electronic database and patients were matched for gender and race. Genomic DNA was extracted from the blood sample, and 4 SNPs (NOD2 rs2066844 R702W, FUT2 rs601338, IL23-R rs1004819, ATG16L1 rs2241880 T300A) were assessed using a TaqMan genotyping assay.

Results: One hundred and sixty-three patients with Crohn’s disease were included in this study; 65% (106/163) were female. Age of onset (Montreal A) was equally distributed between the stricturing and non-stricturing groups (p=0.408). There was no difference in disease location (p=0.814), or the presence of upper GI disease (p=0.274) between the groups. There was no difference in allele frequency or genotype frequency between the stricturing and non-stricturing groups for FUT2, ATG16L1, or IL23-R (Table 1). The T allele (p=0.004) and the TT genotype (p=0.035) in the NOD2 R702W SNP were significantly associated with a non-stricturing phenotype.

Conclusion: We confirmed a significant association between a non-stricturing phenotype and the TT genotype and the T allele in the NOD2 R702W SNP. NOD2 is a well characterized gene that is involved in Crohn’s disease pathophysiology and the results of this study validate the results of large genome wide association studies in a United States population. Further study is required to determine if the NOD2 R702W T allele is a protective factor against stricturing disease.
 

44.03 The Other Side of the Sword: The Role of Autophagy in Survival and Tumor Cell Growth

Posted on January 31, 2019

B. L. Rademacher1, T. Steeno1, K. A. Matkowskyj2, A. Auyeung1, E. H. Carchman1  1University Of Wisconsin,Surgery,Madison, WI, USA 2University Of Wisconsin,Pathology And Laboratory Medicine,Madison, WI, USA

Introduction:  Autophagy is thought to have a dual role in cancer; protective against carcinogenesis, while an important pro-survival mechanism for tumor cells, especially in the setting of treatment (chemotherapy or radiation). We have previously been shown, both pharmacologically and genetically, that autophagy is important in preventing anal carcinogenesis. However, the role of autophagy in already established cancer, in terms of tumor growth and “patient” survival, has yet to be examined. We hypothesized that autophagy is a protective mechanism used by tumor cells to address their increased metabolic needs and that by knocking out autophagy we would decrease tumor growth rates and improve survival. 

Methods:  We generated a conditional, genetic knockout mouse model for the essential autophagic protein Atg7. The generated mice carry Atg7f/f gene globally. They also carry an inducible CreER transgene is expressed from an epithelial-specific K14 transcriptional promotor, and its activity is induced by topical exposure to 4-OH tamoxifen (4-OH TAM), resulting in the knockout of the essential autophagic protein Atg7. For this study, the anuses of the mice were treated with the carcinogen, 7,12 dimethylbenz[a]anthracene (DMBA), until anal cancer developed (2-5 mm in diameter upon entry into the study). Fourteen of the mice were then treated with 4-OH TAM to knockout autophagy locally while twelve were not. Tumor sizes were then measured weekly until euthanasia requirements were met or the mouse died. Tumor volumes were then calculated and normalized to day 0 (date of treatment with 4-OH TAM or not). These tumor volumes were then log transformed, then regressed linearly against time in days, resulting in a slope that equates to the tumor growth rate. Differences in tumor growth rates and mouse survival between the two treatment groups were then examined via independent samples t-test and Kaplan-Meier statistics with Log-Rank comparison, respectively. 

Results: Mice treated with 4-OH TAM had a statistically significant longer mean survival compared to control mice not treated with tamoxifen (98 days vs 49 days, p-value 0.018). In terms of tumor growth rates, there was a trend to decreased mean tumor growth rates in the 4-OH Tam treated group compared to the control group (0.00167 mm/day +/- 0.003 vs 0.00129 mm/day+/-, p-value 0.725).

Conclusion: The localized knockout of autophagy in anal tumors resulted in a trend in decreased growth rates with a significant increase in mouse survival. Increased sample sizes are needed to reduce the variance in tumor growth rates to further elucidate the role of autophagy in tumor growth. 

 

31.10 Variability Between Lateral and Anterior-Posterior (AP) Sacral Ratios in Anorectal Malformations

Posted on January 31, 2019

H. Ahmad1, D. R. Halleran1, A. Akers1, V. Alexander1, M. Levitt1, R. J. Wood1  1Nationwide Childrens Hospital,Center For Colorectal And Pelvic Reconstruction,Columbus, OH, USA

Introduction: The sacral ratio (SR) has been used as a tool to evaluate sacral development in patients with anorectal malformations (ARM) and to help (along with the type of ARM and spinal status) to predict future bowel control. Although the ratio can be calculated using images from either the AP or lateral planes, lateral images are believed to produce more reliable ratios, given that the calculation is not influenced by the tilt of the pelvis. The congruency of the sacral ratio in the AP and lateral planes has not been previously investigated. We therefore aimed to assess the variability in the AP and lateral sacral images.

Methods: We reviewed all patients with ARM treated at our institution  between 2014 and 2018 who had both an AP and lateral image of their sacrum. The SR was calculated using the ratio of the distance from the sacroiliac joint to the tip of the coccyx to the distance from the top of the iliac crest to the sacroiliac joint. All ratios were calculated by a pediatric radiologist. Variation between the SRs as determined by the AP and lateral images were compared across all patients and by ARM type using sacral ratio categories (0-0.39, 0.40-0.69, >0.70)  that were developed for the purpose of counseling families.

Results: 561 patients were included in the study. SRs in the AP plane varied by an average of 17% (IQR 4,25, range 0-154). The AP SR overestimated the lateral SR in 23% (N=128) and underestimated the lateral SR in 63% (N=354) of patients. The variability in measurements decreased with increasing sacral development, as patients with a severe hypodevelopment (SR <0.4, N=39) demonstrated a variation of 27%, patients with moderate hypodevelopment (SR 0.4-0.69, N=193) demonstrated a variation of 18%, and patients with normal sacral development (SR >0.7, N=329) demonstrated a variation of 15%. The difference in these groups was statistically significant (p=0.03).

Conclusion: The SR determined by images in the AP plane varied significantly from that measured using lateral images. These results demonstrate that the AP sacral ratio can lead to a significant misinterpretation of the degree of sacral development which would impair the ability to accurately counsel families on their child’s future continence potential. Based on these data, we recommend the lateral SR to be used as the preferred measure. The AP view remains valuable to assess for hemisacrum. 

 

31.09 Predicting Crohn's Disease Surgery Complications: Harvey Bradshaw Index vs ACS NSQIP Risk Calculator

Posted on January 31, 2019

K. R. McMahon1, C. Cordero-Caballero1, A. Afzali3, S. Husain2  1The Ohio State University Wexner Medical Center,College Of Medicine,Columbus, OHIO, USA 2The Ohio State University Wexner Medical Center,Division Of Colon & Rectal Surgery,Columbus, OHIO, USA 3The Ohio State University Wexner Medical Center,Division Of Gastroenterology, Hepatology, And Nutrition,COLUMBUS, OHIO, USA

Introduction: Gastroenterologists commonly use the Harvey-Bradshaw Index (HBI) to assess the severity of Crohn’s disease (CD) and to guide medical therapy. Surgeons, on the other hand, often use the ACS NSQIP Surgical Risk Calculator to determine surgical risk when treating patients with CD. However, the ACS NSQIP calculator does not account for CD as a risk factor even though it has been shown to be an independent predictor of poor postoperative outcomes. The utility of the HBI to predict surgical complications has not been studied. The aim of our study was to compare the ability of HBI and ACS NSQIP Surgical Risk Calculator to predict surgical complications in patients with Crohn’s disease. We hypothesized that HBI is a superior method of predicting surgical complications in this patient population.

Methods: A retrospective chart review was done to identify patients who underwent surgery for CD and the post-operative complications. Patients who had an HBI calculated prior to, but within one month of surgery, were identified. The ACS NSQIP Surgical Risk Calculator was used to calculate each patient's predicted risk. The group was divided into high and low risk based on the calculator’s listed probability for any complication. Patients were also divided into a low disease activity and high disease activity based on their HBI. Fisher’s exact test, unpaired t-test, and chi-square distribution were used for statistical analysis.

Results: 

A total of 61 patients were included. The average age was 37 years old. 40% were male and 60% female. The overall complication rate was 33%.

There was no significant difference between the high disease activity and low disease activity HBI groups in age, gender, ASA class, steroid use, or NSQIP calculated risk of any complication. There was no significant difference between the NSQIP calculated high and low-risk groups in age, gender, steroid use, or HBI. The higher risk group did correspond to a higher ASA class; this relationship achieved statistical significance (p=0.0113).

The high disease activity HBI group had significantly more surgical complications than the low disease activity group. Additionally, the high disease activity group also had a significantly longer length of hospital stay (table 1). There was no significant difference between the NSQIP calculated high and low-risk groups for surgical complications or length of hospital stay (table 1).     

Conclusion: HBI score appears to be a better predictor of postoperative outcomes than the commonly used ACS NSQIP Surgical Risk Calculator. Further study is needed to examine the relationship between HBI and surgical risk prospectively and in a larger population of patients.   
 

31.08 Do Prolonged Operative Times Obviate the Potential Benefits Associated with Laparoscopic Colectomy?

Posted on January 31, 2019

P. J. Sweigert1, E. Eguia1, A. N. Kothari1, K. A. Ban1, M. H. Nelson1, M. S. Baker1, M. A. Singer1  1Loyola University Medical Center,Department Of Surgery,Maywood, IL, USA

Introduction:
Prior studies have demonstrated that minimally invasive (MIS) approaches to colectomy are oncologically equivalent and associated with shorter lengths of stay, and reduced morbidity in comparison to open approaches to colectomy. There is also increasing evidence that prolonged operative time, especially that greater than 3 hours, is associated with increased rates of postoperative morbidity. Few studies examine the impact of operative time (OT) on the potential benefits afforded by MIS colectomy. We sought to determine if benefits associated with MIS colectomy are maintained in cases where OT is significantly prolonged. 

Methods:
The American College of Surgeons National Surgical Quality Improvement Program (ACS NSQIP) procedure targeted colectomy database was queried to identify adult patients who underwent elective left (LC) and right (RC) colectomy with anastomosis between 2011 and 2016. Emergent or converted cases, patients with preoperative infections, and observations with missing OT data were excluded. Forward stepwise multivariable logistic regression adjusting for demographic and clinical risk factors was used to compare outcomes for prolonged (4th quartile) MIS cases to average (2nd-3rd quartile) open cases with 30-day mortality or serious morbidity as the primary outcome of interest. Secondary 30-day outcomes included any morbidity, mortality, anastomotic leak, surgical site infection (SSI), and prolonged length of stay (LOS). 

Results:
18,274 patients underwent RC and 54,550 LC during the study period. RC was most commonly performed for colon cancer (48.6%). Median OT for open RC was 132 min (IQR 92-189).  That for MIS RC was 135 min (IQR 103-175), p=0.010. LC was also most commonly performed for colon cancer (44.9%). Median OT for open LC was 171 min (IQR 119-242). That for MIS LC was 173 min (IQR 129-231), p=0.001. No difference was seen in the adjusted primary outcome when prolonged MIS cases were compared to average open RC (OR 0.818, 95% CI: [0.660, 1.014]).  Prolonged MIS cases did, however, show a significant benefit in comparison to average length open procedures for adjusted mortality or serious morbidity in LC (OR 0.824, 95% CI: [0.729-0.931]). Prolonged MIS approach was associated with significantly lower morbidity, SSI and LOS for both RC and LC relative to average open colectomy (Table 1). 

Conclusion:
MIS approaches to colectomy are associated with improved rates of postoperative complications, serious morbidity and 30-day mortality relative to open approaches to colectomy.  These benefits are maintained even with OT that extends beyond 3 hours.  Surgeons performing elective MIS colectomy are justified in persisting with prolonged attempts at MIS colectomy. 
 

31.07 Postoperative Length of Stay Following Colorectal Surgery Impact Readmissions

Posted on January 31, 2019

X. L. Baldwin1, P. D. Strassle1, S. Lumpkin1, K. Stitzenberg1  1University Of North Carolina At Chapel Hill,Chapel Hill, NC, USA

Introduction:
Enhanced recovery pathways have led to shorter lengths of stay (LOS) after colorectal surgery. There continues to be controversy about the relationship between LOS and readmission following colorectal surgery. The purpose of this study was to evaluate the association between LOS and readmissions in a nationally representative sample. We hypothesized that shorter LOS would increase readmission rate. 

Methods:
Hospitalizations of adult patients aged 18 – 85 years old, who underwent colon and/or rectal resection between January 2010 and August 2015 in the National Readmission Database were eligible for inclusion. Patients who were treated in December, who were not residents of the state in which they underwent surgery, who died, or who had a LOS <1 day were excluded. Multivariable logistic regression was used to assess the effect of LOS on 30-day readmission, adjusting for patient demographics, comorbidities, hospital characteristics, and inpatient complications.

Results:
We assessed 376,376 hospitalizations. Median LOS was 5 days (IQR 4-8) and 14% of patients (n=51,087) were readmitted within 30 days. As LOS increased, the incidence of readmissions also increased (7% patients with 1 day LOS to 29% in patients with LOS ≥20 days, p<0.0001), Figure 1. After adjustment for patient demographics, comorbidities, inpatient complications, and hospital characteristics, a 5-8 day LOS was associated with a 50% increase in odds of 30-day readmission (OR 1.53, 95% CI 1.05, 1.14, p<0.0001), a 9-12 day LOS was associated with a 100% increase in odds (OR 2.06 95% CI 1.99, 2.13, p<0.0001), and a LOS ≥13 days was associated with an almost 150% increase in odds (OR 2.45 95% CI 2.36, 2.55, p<0.0001), compared to a 1-4 day LOS.

Conclusion:
Contrary to our hypothesis, we found that an increased length of stay resulted in increased readmission rates following colorectal surgery. Shorter LOS decreased the odds of 30-day readmission, regardless of a patient’s pre-existing comorbidities and inpatient complications. Future studies should examine factors associated with prolonged hospitalization and identify possible interventions to decrease readmission in these patients.
 

31.06 Effect of Elective Sigmoidectomy for Diverticulitis on Bowel Function Patient-Reported Outcomes

Posted on January 31, 2019

J. L. Goldwag1,2, R. V. Lyn3, L. R. Wilson1,2, M. Z. Wilson1,2, S. J. Ivatury1,2  1Dartmouth Hitchcock Medical Center,The Department Of Surgery,Lebanon, NH, USA 2Dartmouth Medical School,Lebanon, NH, USA 3Dartmouth College,Hanover, NH, USA

Introduction:
Diverticular disease is common worldwide. A subset of these patients will choose to undergo elective surgical resection due to symptoms or complicated disease. The effect of elective sigmoid colon resection for diverticular disease on bowel function is unclear. The aim of this study is to evaluate changes in bowel function following elective sigmoid resection for diverticular disease.

Methods:
This is a prospective, observational study. We included all patients seen at our institution from May 2015 to July 2018 who underwent elective sigmoid resection for diverticular disease. We used the Colorectal Functional Outcome Questionnaire (COREFO), a validated bowel function questionnaire that assesses bowel function in five domains and a global function score. Scores range from zero to 100 with a higher score indicating worse function. We obtained questionnaire data at baseline as well as at postoperative follow-up. Patients were included if they completed both questionnaires and underwent elective sigmoid resection.  Patients were excluded if they remained in bowel discontinuity or did not complete both questionnaires. A paired t-test was used to compare baseline and post-intervention scores.

Results:
49 patients met criteria for inclusion in this study. The median time between questionnaire completion was 70 days (IQR: 56 to 85). The mean age was 60 ± 12 years with 57% female patients. 36 (73%) patients underwent sigmoidectomy alone and 13 (27%) underwent sigmoidectomy with fistula repair. Six patients (12%) had a diverting loop ileostomy in addition to sigmoidectomy and underwent a subsequent reversal. Overall, there was no difference in Total COREFO score from baseline to post-intervention.  There were also no differences in any of the five COREFO domains (Figure 1).

Conclusion:
Bowel function does not change in the postoperative period following elective sigmoid resection for diverticular disease. Surgeons should counsel patients, especially symptomatic ones, that bowel function will be no different at time of postoperative follow-up.
 

31.05 Opioid Tolerance Impacts Major Abdominal Surgery Outcomes in Patients on Enhanced Recovery Pathway.

Posted on January 31, 2019

M. H. Zaman1, O. P. Owodunni2, M. Ighani2, M. Grant3, D. Bettick4, S. Sateri3, T. Magnuson2, S. Gearhart2  1The Johns Hopkins University School Of Medicine,Urology,Baltimore, MD, USA 2The Johns Hopkins University School Of Medicine,Surgery,Baltimore, MD, USA 3The Johns Hopkins University School Of Medicine,Anesthesia,Baltimore, MD, USA 4The Johns Hopkins Bayview Medical Center,Quality,Baltimore, MD, USA

Introduction: Chronic opioid exposure can lead to a state of tolerance in patients where increasing doses of opioids are necessary to reduce pain; this can make postoperative management difficult. An Enhanced Recovery Pathway (ERP) is an evidence-based intervention that focuses on optimizing recovery and postoperative outcomes. The effectiveness of an ERP depends on the degree of compliance with the pathway. We wish to determine the effects of opioid tolerance in patients undergoing abdominal surgery on an ERP and its impact on compliance and postoperative outcomes. 

Methods:  From January 2013 to June 2017, patients undergoing major abdominal surgery prior to and following ERP-implementation were included. Patients <18 years and having emergency surgery were excluded. Compliance was measured to 14 perioperative pathway variables and high-compliance was defined as achieving ≥75%. Opioid tolerance was defined as any patient taking a prescribed opioid medication equivalent to 60 mg of Morphine per day for one week prior to surgery.  CR-POSSUM scores were used for risk-adjusted analyses. Outcomes of interest include length of stay (LOS), major-complications (Clavien-Dindo“CD”≥2), and 30-day readmission rates. 

Results: 1251 patients (605 pre-ERP and 646 ERP patients) were included. A total of 221 patients were opioid tolerant. Opioid tolerant patients were more likely to be younger (56 vs. 59 years, P=0.002), have disseminated cancer (11% vs. 5 %, P=0.003) and have an open procedure (69% vs. 60%, P=0.01) than non-tolerant patients. When comparing opioid-tolerant patients prior to (107 patients) and following EPR implementation (114 patients), there was no difference in demographic and clinical characteristics; however, more opioid-tolerant patients following ERP implementation had a laparoscopic procedure (42% vs. 19%, P<0.001).  In a multivariable analysis, opioid tolerance was associated with an increase in major complications (OR 1.24, p=0.032) and in readmissions (OR 1.42, p=0.005).  Among the ERP cohort, opioid-tolerant patients were less likely to be highly compliant with ERP variables than non-tolerant patients (35% vs. 54%; p<.001). Opioid tolerance was associated with a higher median LOS (5 days vs. 4 days; p<0.02) and a higher readmission rate (24% vs. 13%; p<0.01) than non-opioid tolerant ERP patients. In opioid-tolerant patients, high compliance with ERP was associated with a decreased odds of major complications (OR: 0.10, p<.001) and a reduction in the readmission rate (OR: 0.7, p=0.003). Opioid tolerance was an independent predictor of non-compliance with ERP (OR: 0.44, p<.001).

Conclusion: We provide evidence that opioid tolerance is associated with less favorable outcomes in patients undergoing major abdominal surgery and on an ERP; this is likely due to lack of pathway compliance.  Minimizing opioid use prior to elective major abdominal surgery may improve compliance and postoperative outcomes.

31.04 Transverse Abdominis Plane Block Vs Intrathecal Analgesia in Colorectal Surgery: A Randomized Trial

Posted on January 31, 2019

D. Colibaseanu1, O. Osagiede2, A. Merchea1, C. Thomas6, E. Bojaxhi3, J. Panchamia5, A. Jacob5, S. Kelley4, K. Mathis4, A. Lightner4, J. Naessens6, D. W. Larson4  1Mayo Clinic – Florida,Section Of Colon And Rectal Surgery,Jacksonville, FL, USA 2Mayo Clinic – Florida,Health Sciences Research,Jacksonville, FL, USA 3Mayo Clinic – Florida,Department Of Anesthesiology,Jacksonville, FL, USA 4Mayo Clinic,Division Of Colon And Rectal Surgery,Rochester, MN, USA 5Mayo Clinic,Department Of Anesthesiology,Rochester, MN, USA 6Mayo Clinic,Health Sciences Research,Rochester, MN, USA

Introduction: Transversus abdominis plane (TAP) block is an effective alternative to neuraxial analgesia in abdominal surgery; however, limited evidence supports its use over traditional analgesic modalities in colorectal surgery. We compared the analgesic efficacy of liposomal bupivacaine TAP block and intrathecal (IT) opioids in a prospective randomized trial. The primary outcomes were the mean pain score and morphine milligram equivalents (MME) used within the first 48 hours post-surgery. Secondary outcomes included length of stay, standardized costs, postoperative ileus, and intravenous patient-controlled analgesia use. 

Methods: Patients were recruited from two campuses of a single institution. Two hundred and nine patients undergoing elective small bowel or colorectal resections were enrolled. They were randomized to receive either bilateral TAP block or single-injection IT analgesia with hydromorphone. Patients were assessed at 4, 8, 16, 24, and 48 hours post-surgery.

Results: Two hundred patients completed the trial (TAP =102, IT N=98). The TAP group had a mean pain score 1.7 points higher than the IT group 4 hours post-surgery, persisting up to 16 hours post-surgery. There was evidence of higher MME use < 24 hours post-surgery in the TAP group compared to IT (median difference: 10.0 MME, 95% CI 3.0 – 20.5 MME). No difference in MME was observed between the two groups at 24 and 48 hours, or in secondary outcomes.

Conclusions: Intrathecal opioids provided better immediate postoperative pain control compared to liposomal bupivacaine TAP block, lasting up to 16 hours post-surgery. Both modalities provided adequate pain control in patients enrolled in this study, and should be considered as part of a multimodal postoperative analgesic plan for patients undergoing elective colorectal surgery.

 

 

31.03 Postoperative Biologics Reduce the Risk of Recurrent Ileocolectomy

Posted on January 31, 2019

B. P. Kline1, T. Weaver1, A. Berg2, W. Koltun1  1Penn State University College Of Medicine,Deparment Of Surgery, Division Of Colon And Rectal Surgery,Hershey, PA, USA 2Penn State University College Of Medicine,Department Of Public Health Sciences,Hershey, PA, USA

Introduction:
Biologic medications are often prescribed to patients with Crohn’s disease after ileocolectomy to decrease the incidence of recurrent disease. Previous studies have focused primarily on their effect on recurrence of clinical symptoms or on endoscopic recurrence. There has been relatively little data on whether these biologics actually increase the time to a recurrent ileocolectomy or protect against the need for repeat surgery.

Methods:
A 28 year retrospective chart review was performed on 409 patients with Crohn’s disease who had undergone ileocolectomy and had been prospectively recruited into the Colorectal Diseases Biobank at our institution. The study cohort was made up of 241 of these patients who were biologic therapy naive prior to their initial ileocolectomy. 106 patients received biologics (infliximab, adalimumab, certolizumab pegol, vedolizumab, or ustekinumab) after their initial surgery (ICB group) and were compared to 135 patients who did not receive biologics (IC group). Clinical characteristics including sex, race, family history of IBD, smoking history, age of onset, date of diagnosis, Montreal classification, number of ileocolectomies, date of each ileocolectomy, and date of last visit were documented. Multivariate Cox proportional-hazards was used to model time to recurrent ileocolectomy after initial surgery. Covariates included the presence of biologics, smoking, sex, family history, and Montreal classification.

Results:
There was no significant difference in sex, race, family history, smoking history, age of diagnosis, or Montreal classification between the two groups. The mean follow up time was 11.8 years in the ICB group vs 14.8 years in the IC group. Only 34 of the 106 patients in the ICB group had subsequent surgeries compared to 65 of the 135 in the IC group (32% vs 48%, p = 0.017). On multivariate analysis, the presence of biologics reduced the hazard ratio (risk of a second surgery) by 40% (confidence interval: 7%-61%, p = 0.023). No other covariates had a significant impact on risk of recurrent surgery. The probability of a 2nd ileocolectomy over time is shown in the attached time to event figure.

Conclusion:
Patients who were placed on biologics after an initial ileocolectomy had a 40% decreased risk of requiring a second surgery. This led to both a lower number of subsequent ileocolectomies and an extended interval between surgeries in those patients that received biologics. This study confirms the effect of biologics in increasing the interval to a second ileocolectomy in patients with Crohn’s disease.

31.02 Patient Engagement with Mobile Applications Does Not Differ by Level of Health Literacy

Posted on January 31, 2019

K. E. Hudak1, M. F. Gleason1, S. J. Baker1, L. N. Wood2, J. A. Cannon2, M. S. Morris2, G. D. Kennedy2, D. I. Chu2  1University Of Alabama at Birmingham,Birmingham, Alabama, USA 2University Of Alabama at Birmingham,Department Of Gastrointestinal Surgery,Birmingham, Alabama, USA

Introduction: Patient engagement applications provide an electronic platform to guide patients recovering from surgery. From self-monitoring to quality of life surveys, these applications promote patient engagement through the surgical journey. It is unclear, however, whether patients with low health literacy have similar levels of engagement compared to those with adequate health literacy. Our objective was to characterize the utilization of a patient engagement application with patients with low health literacy. We hypothesized that differences in utilization measures would exist based on differences in health literacy.  

Methods:  Patients undergoing elective colorectal surgery at our institution from January to June 2018 were sequentially enrolled in a patient engagement application. A pre-operative survey was given which included a validated 3-question self-reported health literacy instrument. Patients were stratified by health literacy scores to four levels (high, intermediate high, intermediate, and low). Patients underwent surgery and were followed 30-days post-operatively. The primary outcomes were utilization measures which were defined as the number of days using the application, response rate to five individual surveys, and days to completion of each survey. Comparisons were made using ANOVA and chi-squared tests.

Results: A total of 78 patients enrolled in a patient engagement platform and underwent elective colorectal surgery with 30-day follow-up. The mean age was 59 years (IQR 15-83), 43.6% were female (n=34), and 17.9% were African American (n=14) with the remainder being white (82.1%, n=64).  On assessment of health literacy level, 43.6%  (n=34) of patients had high health literacy, 23.1% (n=18) had intermediate high, 19.2% (n=15) had intermediate, and 14.1% (n=11) had low health literacy.  Of low health literacy patients, 18.2% were female (n=2), compared to 53.3% (n=8) of intermediate, 44.4% (n=8) of intermediate high, and 47.1% (n=16) high health literacy (p=0.02).  There were no statistical differences in age or race by health literacy. The average number of days spent using the application was 8.5 days with a range of 7.9 to 9.2 days. The average response rate to the first five individual surveys was 100% for survey 1, 57.7% for survey 2, 52.6% for survey 3, 33.3% for survey 4, and 47.4% for survey 5. The average days to survey completion was 29.8 days with a range of 3.1 to 59.4 days.  On comparison by health literacy levels, there was no significant difference in utilization rates by number of days using the application, survey response rate, or days to completion of survey (p>0.05).

Conclusion: Patients with all levels of health literacy, including those with low health literacy, had similar engagement with a patient engagement platform after major surgery. These results suggest a potential role for such technology in caring for postoperative patients of all health literacy levels.

 

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