The viscoelasticity of high concentration monoclonal antibodies using particle tracking microrheology.

The viscoelasticity of monoclonal antibodies (mAbs) is important during their production, formulation, and drug delivery. High concentration mAbs can provide higher efficacy therapeutics (e.g., during immunotherapy) and improved efficiency during their production (economy of scale during processing). Two humanized mAbs were studied (mAb-1 and mAb-2) with differing isoelectric points. Using high speed particle tracking microrheology, we demonstrated that the mAb solutions have significant viscoelasticities above concentrations of 40 mg/ml. Power law viscoelasticity was observed over the range of time scales (10-4-1 s) probed for the high concentration mAb suspensions. The terminal viscosity demonstrated an exponential dependence on mAb concentration (a modified Mooney relationship) as expected for charged stabilized Brownian colloids. Gelation of the mAbs was explored by lowering the pH of the buffer and a power law scaling of the gelation transition was observed, i.e., the exponent of the anomalous diffusion of the probe particles scaled inversely with the gelation time.

A modular and multi-functional purification strategy that enables a common framework for manufacturing scale integrated and continuous biomanufacturing.

Biopharmaceutical manufacture is transitioning from batch to integrated and continuous biomanufacturing (ICB). The common framework for most ICB, potentially enables a global biomanufacturing ecosystem utilizing modular and multi-function manufacturing equipment. Integrating unit operation hardware and software from multiple suppliers, complex supply chains enabled by multiple customized single-use flow paths, and large volume buffer production/storage make this ICB vision difficult to achieve with commercially available manufacturing equipment. Thus, we developed SymphonX™, a downstream processing skid with advanced buffer management capabilities, a single disposable generic flow path design that provides plug-and-play flexibility across all downstream unit operations and a single interface to reduce operational risk. Designed for multi-product and multi-process cGMP facilities, SymphonX™ can perform stand-alone batch processing or ICB. This study utilized an Apollo™ X CHO-DG44 mAb-expressing cell line in a steady-state perfusion bioreactor, harvesting product continuously with a cell retention device and connected SymphonX™ purification skids. The downstream process used the same chemistry (resins, buffer composition, membrane composition) as our historical batch processing platform, with SymphonX™ in-line conditioning and buffer concentrates. We used surge vessels between unit operations, single-column chromatography (protein A, cation and anion exchange) and two-tank batch virus inactivation. After the first polishing step (cation exchange), we continuously pooled product for 6 days. These 6 day pools were processed in batch-mode from anion exchange to bulk drug substance. This manufacturing scale proof-of-concept ICB produced 0.54 kg/day of drug substance with consistent product quality attributes and demonstrated successful bioburden control for unit-operations undergoing continuous operation.

Surgical Site Infection Prevention Using "Strike Teams": The Experience of an Academic Colorectal Surgical Department.

ABSTRACT: Surgical site infections (SSIs) are healthcare-acquired infections with substantial morbidity. Surgical site infection persist because of low adherence to prevention bundles comprising multiple infection control elements. We propose the "Strike Team" as an implementation strategy to improve adherence and reduce SSI in colorectal surgery. At an academic medical center, a multidisciplinary Strike Team met monthly to review colorectal SSI cases, audit and discuss barriers to adherence to SSI prevention bundle, and propose actionable feedback. The latter was shared with frontline clinicians by the Strike Team's surgical leaders in everyday practice. Colorectal SSI rates and bundle adherence data were disseminated quarterly via the hospital intranet and reviewed with surgeons at departmental meetings. Trends in adherence and SSI rates were analyzed by regression analysis using a time series model. While the Strike Team was active, adherence to antibiotic prophylaxis, maintenance of normoglycemia, and standardized intraoperative skin preparation significantly increased (p < .05). There was a trend toward statistically significant reduction in SSI (p = .07), although it was not maintained once the Strike Team activity was disrupted by the COVID-19 pandemic. Colorectal SSI prevention requires a resource-intensive, multidisciplinary approach with numerous strategies to improve adherence to infection control bundles, as illustrated by our SSI Strike Team experience.

Treating acute diverticulitis in pre- and post-solid-organ transplant patients: a single-institution cohort study.

AIM: Immunosuppressed patients are more likely to fail nonoperative management of acute diverticulitis and have more postoperative complications than the immunocompetent. Transplant recipients form a subcategory among the immunosuppressed with unique challenges. The aim of this work is to report 30-day postoperative complications after colectomy for acute diverticulitis and success rates of nonoperative management in pre- and post-transplant patients. METHOD: This is a retrospective cohort study at a single-institution tertiary referral centre. Patients with a history of acute diverticulitis were extracted from a database of 6152 recipients of solid-organ abdominal transplant between 2000 and 2015 and stratified by the index episode of diverticulitis: before or after solid-organ transplant surgery. Outcomes included 30-day postoperative complications and failure of nonoperative management. RESULTS: Acute diverticulitis occurred in 93 patients, 69 (74%) posttransplant. Postcolectomy complications were higher posttransplant than pretransplant (43% vs. 13%, p = 0.04). Posttransplant status was not an independent risk factor for complications (odds ratio 3.59, 95% CI 0.79-16.31) when adjusting for sex and surgical acuity. Immediate urgent colectomy (29% vs. 31%, p = 0.84) and failure of nonoperative management (7% vs. 9%, p = 0.82) were similar. Complications occurred equally in those requiring urgent colectomy after nonoperative management and those undergoing immediate urgent colectomy. CONCLUSION: Urgent colectomy rates are similar in solid-organ abdominal transplant recipients pre- and posttransplant. Posttransplant complication rates appear to be increased but transplant status as an independent factor is not significantly associated with an increased risk in this study cohort. These findings should be considered when counselling patients on the relative risks and benefits of surgical intervention for diverticulitis before versus after solid-organ transplantation.

Surgeons' mental models of surgical site infection: Insights into adherence with complex prevention bundles.

Of 10 surgeons interviewed in a descriptive qualitative study, 6 believed that surgical site infections are inevitable. Bundle adherence was felt to be more likely with strong evidence-based measures developed by surgical leaders. The intrinsic desire to excel was viewed as the main adherence motivator, rather than "pay-for-performance" models.

Prevalence of High-Grade Anal Dysplasia and Anal Cancer in Veterans Living With HIV and CD4/CD8 Ratio as a Marker For Increased Risk: A Regional Retrospective Cohort Study.

BACKGROUND: The Department of Veterans Affairs cares for the largest population of patients with HIV of any healthcare system in the United States. Screening for anal dysplasia/cancer is recommended for all veterans with HIV. Exams are invasive, burdensome, and resource intensive. We currently lack markers of disease to tailor screening. OBJECTIVE: The purpose of this study was to establish the prevalence of advanced anal disease (high-grade dysplasia and anal cancer) and to determine whether CD4/CD8 ratio correlates with risk. DESIGN: This was a retrospective regional cohort study of veterans with HIV. SETTINGS: The study was conducted at eight medical centers between 2001 and 2019. PATIENTS: Patients with advanced disease were compared with patients with nonadvanced anal pathology. MAIN OUTCOME MEASURES: Logistic regression modeling was used to estimate adjusted odds of disease as a function of CD4/CD8. Lowest (nadir) CD4/CD8 and nearest CD4/CD8 ratio in each cohort were evaluated. RESULTS: A total of 2267 veterans were included. Fifteen percent had anal pathology (112 with advanced disease (37 cancer and 75 high-grade), 222 with nonadvanced disease). Nadir and nearest ratio were lower in patients with advanced disease versus nonadvanced (0.24 vs 0.45 (p < 0.001) and 0.50 vs 0.88 (p < 0.001)). In adjusted models, a 1-unit increase in nadir or nearest ratio conferred decreased risk of advanced disease (OR = 0.19 (95% CI, 0.07-0.53); p < 0.001; OR = 0.22 (95% CI, 0.12-0.43); p < 0.001). Using a minimum sensitivity analysis, a cutoff nadir ratio of 0.42 or nearest ratio of 0.76 could be used to risk stratify. LIMITATIONS: This was a retrospective analysis with a low screening rate. CONCLUSIONS: In a regional cohort of veterans with HIV, 15% were formally assessed for anal dysplasia. Advanced anal disease was present in 33% of those screened, 5% of the HIV-positive population. A strong predictor of advanced disease in this cohort is the CD4/CD8 ratio, which is a promising marker to stratify screening practices. Risk stratification using CD4/CD8 has the potential to decrease burdensome invasive examinations for low-risk patients and to intensify examinations for those at high risk. See Video Abstract at http://links.lww.com/DCR/B528. PREVALENCIA DE DISPLASIA ANAL DE ALTO GRADO Y CNCER ANAL EN VETERANOS QUE VIVEN CON EL VIH Y LA RELACIN CD / CD COMO MARCADOR DE MAYOR RIESGO UN ESTUDIO DE COHORTE REGIONAL RETROSPECTIVE: ANTECEDENTES:El Departamento de Asuntos de Veteranos atiende a la población más grande de pacientes con el virus de inmunodeficiencia humana (VIH) de cualquier sistema de salud en los Estados Unidos. Se recomienda la detección de displasia / cáncer anal para todos los veteranos con VIH. Los exámenes son invasivos, onerosos y requieren muchos recursos. Actualmente carecemos de marcadores de enfermedad para adaptar la detección.OBJETIVO:Establecer la prevalencia de enfermedad anal avanzada (displasia de alto grado y cáncer anal) y determinar si la relación CD4 / CD8 se correlaciona con el riesgo.DISEÑO:Estudio de cohorte regional retrospectivo de veteranos con VIH.AJUSTE:Ocho centros médicos entre 2001-2019.PACIENTES:Se comparó a pacientes con enfermedad avanzada con pacientes con patología anal no avanzada.PRINCIPALES MEDIDAS DE RESULTADO:Se utilizó un modelo de regresión logística para estimar las probabilidades ajustadas de enfermedad en función de CD4 / CD8. Se evaluó la relación CD4 / CD8 más baja (nadir) y la relación CD4 / CD8 más cercana en cada cohorte.RESULTADOS:Se incluyeron un total de 2267 veteranos. El 15% tenía patología anal (112 enfermedad avanzada (37 cáncer, 75 de alto grado), 222 enfermedad no avanzada). El nadir y el cociente más cercano fueron menores en los pacientes con enfermedad avanzada frente a los no avanzados (0,24 frente a 0,45 (p <0,001) y 0,50 frente a 0,88 (p <0,001)), respectivamente. En modelos ajustados, el aumento de una unidad en el nadir o el cociente más cercano confirió una disminución del riesgo de enfermedad avanzada (OR 0,19 (IC del 95%: 0,07, 0,53, p <0,001)) y (OR 0,22 (IC del 95%: 0,12, 0,43, p <0,001))), respectivamente. Utilizando un análisis de sensibilidad mínima, se podría utilizar un cociente del nadir de corte de 0,42 o el cociente más cercano de 0,76 para estratificar el riesgo.LIMITACIONES:Análisis retrospectivo con una tasa de detección baja.CONCLUSIONES:En una cohorte regional de veteranos con VIH, el 15% fueron evaluados formalmente por displasia anal. La enfermedad anal avanzada estuvo presente en el 33% de los examinados, el 5% de la población VIH +. Un fuerte predictor de enfermedad avanzada en esta cohorte es la relación CD4 / CD8, que es un marcador prometedor para estratificar las prácticas de detección. La estratificación del riesgo usando CD4 / CD8 tiene el potencial de disminuir los exámenes invasivos onerosos para los pacientes de bajo riesgo e intensificar los exámenes para los de alto riesgo. Consulte Video Resumen en http://links.lww.com/DCR/B528.

The Optimal Ileal Pouch: Physiologic Parameters Significantly Correlate with Overall Pouch Function.

BACKGROUND: Ileal pouch function is affected by several patient factors and pouch physiology. The significance of pouch physiology on optimal pouch function has not been well characterized. The purpose of this study was to examine specific post-ileal pouch anal anastomosis (IPAA) physiologic parameters to determine impact on pouch function and quality of life. METHODS: Patients undergoing proctocolectomy with IPAA for ulcerative colitis were examined. Post-IPAA compliance, pouch anal pressure gradient (PAPG), and function were assessed 6-8 months postoperatively. Compliance was calculated as change in volume divided by change in pressure. PAPG was calculated as the difference between anal pressure and intra-pouch pressure at a fixed volume. Pouch function evaluation included stool frequency and episodes of incontinence. Quality of life was evaluated using the Rockwood Fecal Incontinence Quality of Life Scale. RESULTS: A total of 125 patients were investigated. Post-IPAA resting anal pressure averaged 58.1 ± 15 mmHg. Mean volume and intra-pouch pressure at evacuation were 245 mL and 33.9 mmHg, respectively. Compliance averaged 11.2 mmHg/mL with a mean PAPG of - 29.3 mmHg. Compliance and PAPG correlated with 24-h (p = 0.003, p = 0.004) and nighttime stool frequency (p = 0.04, p = 0.03). Daytime continence was impacted by compliance (p = 0.04), PAPG (p = 0.02), and resting anal pressure (p = 0.02). CONCLUSION: This unique evaluation reveals a significant correlation between IPAA physiologic properties and function. Optimal function and quality of life depend in part on maintaining optimal pouch compliance and pressure differentials between the pouch and anal canal, defined by the pouch anal pressure gradient.

Gaining momentum in colorectal surgical site infection reduction through a human factors engineering approach.

Surgical site infection (SSI) prevention requires multiple interventions packaged into "bundles." The implementation of all bundle elements is key to the bundle's efficacy. A human-factors engineering approach can be used to identify key barriers and facilitators to implementing elements and develop recommendations for bundle implementation within the clinical work system.

Colorectal bundles for surgical site infection prevention: A systematic review and meta-analysis.

OBJECTIVE: In colorectal surgery, the composition of the most effective bundle for prevention of surgical site infections (SSI) remains uncertain. We performed a meta-analysis to identify bundle interventions most associated with SSI reduction. METHODS: We systematically reviewed 4 databases for studies that assessed bundles with ≥3 elements recommended by clinical practice guidelines for adult colorectal surgery. The main outcome was 30-day postoperative SSI rate (overall, superficial, deep, and/or organ-space). RESULTS: We included 40 studies in the qualitative review, and 35 studies (54,221 patients) in the quantitative review. Only 3 studies were randomized controlled trials. On meta-analyses, bundles were associated with overall SSI reductions of 44% (RR, 0.57; 95% CI, 0.48-0.65); superficial SSI reductions of 44% (RR, 0.56; 95% CI, 0.42-0.75); deep SSI reductions of 33% (RR, 0.67; 95% CI, 0.46-0.98); and organ-space SSI reductions of 37% (RR, 0.63; 95% CI, 0.50-0.81). Bundle composition was heterogeneous. In our meta-regression analysis, bundles containing ≥11 elements, consisting of both standard of care and new interventions, demonstrated the greatest SSI reduction. Separate instrument trays, gloves with and without gown change for wound closure, and standardized postoperative dressing change at 48 hours correlated with the highest reductions in superficial SSIs. Mechanical bowel preparation combined with oral antibiotics, and preoperative chlorhexidine showers correlated with highest organ-space SSI reductions. CONCLUSIONS: Preventive bundles emphasizing guideline-recommended elements from both standard of care as well as new interventions were most effective for SSI reduction following colorectal surgery. High clinical-bundle heterogeneity and low quality for most observational studies significantly limit our conclusion.

Large-Field-of-View Visualization with Small Blind Spots Utilizing Tilted Micro-Camera Array for Laparoscopic Surgery.

Existing laparoscopic surgery systems use a single laparoscope to visualize the surgical area with a limited field of view (FoV), necessitating maneuvering the laparoscope to search a target region. In some cases, the laparoscope needs to be moved from one surgical port to another one to detect target organs. These maneuvers would cause longer surgical time and degrade the efficiency of operation. We hypothesize that if an array of cameras can be deployed to provide a stitched video with an expanded FoV and small blind spots, the time required to perform multiple tasks at different sites can be significantly reduced. We developed a micro-camera array that can enlarge the FoV and reduce blind spots between the cameras by optimizing the angle of cameras. The video stream of this micro-camera array was designed to be processed in real-time to provide a stitched video with the expanded FoV. We mounted this micro-camera array to a Fundamentals of Laparoscopic Surgery (FLS) laparoscopic trainer box and designed an experiment to validate the hypothesis above. Surgeons, residents, and a medical student were recruited to perform a modified bean drop task, and the completion time was compared against that measured using a traditional single-camera laparoscope. It was observed that utilizing the micro-camera array, the completion time of the modified bean drop task was 203 ± 55 s while using the laparoscope, the completion time was 245 ± 114 s, with a p-value of 0.00097. It is also observed that the benefit of using an FoV-expanded camera array does not diminish for subjects who are more experienced. This test provides convincing evidence and validates the hypothesis that expanded FoV with small blind spots can reduce the operation time for laparoscopic surgical tasks.

Large-Field-of-View Visualization Utilizing Multiple Miniaturized Cameras for Laparoscopic Surgery.

The quality and the extent of intra-abdominal visualization are critical to a laparoscopic procedure. Currently, a single laparoscope is inserted into one of the laparoscopic ports to provide intra-abdominal visualization. The extent of this field of view (FoV) is rather restricted and may limit efficiency and the range of operations. Here we report a trocar-camera assembly (TCA) that promises a large FoV, and improved efficiency and range of operations. A video stitching program processes video data from multiple miniature cameras and combines these videos in real-time. This stitched video is then displayed on an operating monitor with a much larger FoV than that of a single camera. In addition, we successfully performed a standard and a modified bean drop task, without any distortion, in a simulator box by using the TCA and taking advantage of its FoV which is larger than that of the current laparoscopic cameras. We successfully demonstrated its improved efficiency and range of operations. The TCA frees up a surgical port and potentially eliminates the need of physical maneuvering of the laparoscopic camera, operated by an assistant.

A tertiary care hospital's 10 years' experience with rectal ultrasound in early rectal cancer.

BACKGROUND AND OBJECTIVES: Rectal endoscopic ultrasound (RUS) has become an essential tool in the management of rectal adenocarcinoma because of the ability to accurately stage lesions. The aim of this study was to identify the staging agreement of early RUS-staged rectal adenocarcinoma with surgical resected pathology and ultimately determine how this impacts the management of early rectal cancer (T1-T2). METHODS: Retrospective chart review was performed from November 2002 to November 2013 to identify procedure indication, RUS staging data, surgical management, and postoperative surgical pathology data. RESULTS: There were a total of 693 RUS examinations available for review and 282 of these were performed for a new diagnosis of rectal adenocarcinoma. There was staging agreement between RUS and surgical pathology in 19 out of 20 (95%) RUS-staged T1 cases. There was staging agreement between RUS and surgical pathology in 3 out of 9 (33%) RUS-staged T2 cases. There was significantly better staging agreement for RUS-staged T1 lesions compared to RUS staged T2 lesions (P = 0.002). Nearly 60% of T1N0 cancers were referred for transanal excisions (TAEs), and 78% of T2N0 cancers underwent low anterior resection. CONCLUSIONS: This study identified only a small number of T1-T2 adenocarcinomas. There was good staging agreement between RUS and surgical pathology among RUS-staged T1 lesions whereas poor staging agreement among RUS-staged T2 lesions. Although TAE is largely indicated by the staging of a T1 lesion, this approach may be less appropriate for T2 lesions due to high reported local recurrence.

Associations of Specific Postoperative Complications With Outcomes After Elective Colon Resection: A Procedure-Targeted Approach Toward Surgical Quality Improvement.

Importance: Numerous quality initiatives have been implemented in an effort to minimize the onus of postoperative complications on clinical and economic outcomes after major surgery. It is unknown which complications have the greatest overall effect on these outcomes. Objective: To quantify the associations of specific postoperative complications with outcomes after elective colon resection. Design, Setting, and Participants: Patients undergoing elective colon resection between January 1, 2012, and December 31, 2013, who were included in the Colectomy-Targeted American College of Surgeons National Surgical Quality Improvement Program were assessed for the development of specific types of postoperative complications. The overall contributions of these complications to subsequent clinical and resource use outcomes were assessed. Main Outcomes and Measures: The main outcomes were 30-day mortality, end-organ dysfunction, reoperation, prolonged hospitalization, nonroutine discharge status, and hospital readmission. Risk-adjusted population attributable fractions were estimated for each complication-outcome pair. The population attributable fractions for a specific complication represented the percentage reduction in a given outcome that would be expected if exposure to that complication was completely eliminated. Results: A total of 26 682 patients undergoing elective colon resection were included for analysis; 13 870 patients were women (52.0%) and 15 088 (56.5%) were younger than 65 years. The most common index complications were ileus (n = 3140; 11.8%), bleeding (n = 2032; 7.6%), and incisional surgical site infection (n = 1873; 7.0%). Anastomotic leak was associated with the incidence of end-organ dysfunction, mortality, reoperation, and hospital readmission, with estimated population attributable fractions of 33.3% (95% CI, 29.6-36.8), 20.0% (95% CI, 14.0-25.7), 48.4% (95% CI, 45.7-51.0), and 20.6% (95% CI, 19.1-22.1) for each of these respective outcomes. The effect of complications, such as urinary tract infection, venous thromboembolism, and myocardial infarction, on these outcomes was comparatively small. Conclusions and Relevance: Anastomotic leak has a large overall effect on 30-day clinical and economic outcomes after elective colon resection. The findings of our study support the adoption of a procedure-targeted approach to surgical quality improvement and describe a practical method for assessing complication effect.

Short-term outcomes of minimally invasive versus open colectomy for colon cancer.

BACKGROUND: Laparoscopic and open approaches to colon resection have equivalent long-term outcomes and oncologic integrity for the treatment of colon cancer. Differences in short-term outcomes should therefore help to guide surgeons in their choice of operation. We hypothesized that minimally invasive colectomy is associated with superior short-term outcomes compared to traditional open colectomy in the setting of colon cancer. MATERIALS AND METHODS: Patients undergoing nonemergent colectomy for colon cancer in 2012 and 2013 were selected from the American College of Surgeons National Surgical Quality Improvement Program (ACS-NSQIP) targeted colectomy participant use file. Patients were divided into two cohorts based on operative approach-open versus minimally invasive surgery (MIS). Univariate, multivariate, and propensity-adjusted multivariate analyses were performed to compare postoperative outcomes between the two groups. RESULTS: A total of 11,031 patients were identified for inclusion in the study, with an overall MIS rate of 65.3% (n = 7200). On both univariate and multivariate analysis, MIS approach was associated with fewer postoperative complications and lower mortality. In the risk-adjusted multivariate analysis, MIS approach was associated with an odds ratio of 0.598 for any postoperative morbidity compared to open (P < 0.001). CONCLUSIONS: This retrospective study of patients undergoing colectomy for colon cancer demonstrates significantly improved outcomes associated with a MIS approach, even when controlling for baseline differences in illness severity. When feasible, minimally invasive colectomy should be considered gold standard for the surgical treatment of colon cancer.

Does Anastomotic Leak Contribute to High Failure-to-rescue Rates?

OBJECTIVE: Our aim was to evaluate failure-to-rescue (FTR) after anastomotic leak (AL) in colectomy patients. BACKGROUND: In the era of pay for performance, it is imperative that we understand the quality measures under which we are scrutinized. FTR has been proposed as a marker of surgical quality. We investigated the role of complications in FTR rates in colectomy patients. METHODS: Patients who underwent nonemergent colectomy from 2012 to 2013 were identified from the The American College of Surgeons National Quality Improvement Program (ACS NSQIP database). Mortality after AL was assessed and stratified in relation to mortality after other postoperative complications. χ and logistic regression analysis were used to assess the effect of AL on mortality. RESULTS: We identified 30,101 patients who met inclusion criteria, 1127 suffered an AL (3.7%). FTR was increased in patients with AL compared with those without AL (6% vs 1%, P < 0.001). The mortality rate after leak was similar to mortality after other major complications. Independent risk factors for death after AL included older age (odds ratio [OR] 3.140; 95% confidence interval [CI], 1.744-5.651), cancer diagnosis (OR 2.032; 95% CI, 1.177-3.507), and open approach (OR 2.124; 95% CI, 1.194-3.776) while preoperative bowel preparation was protective (OR 0.563; 95% CI, 0.328-0.969). CONCLUSIONS: AL is a common complication after colectomy with a relatively high FTR rate. As hospitals are penalized for not reaching specific rates of FTR, we must better understand these complex relationships to improve quality and safety of patient care.

Postoperative Ileus--More than Just Prolonged Length of Stay?

PURPOSE: Given that postoperative ileus is common in colectomy patients, we sought to examine the association of ileus with adverse events in this patient population. METHODS: The ACS NSQIP puf file from 2012 to 2013 was queried for non-emergent colectomy cases. Predictors of other poor postoperative outcomes in patients who experienced postoperative ileus were assessed using chi-squared and multivariable regression analyses. Chi-squared analysis was used to assess for additive effects of ileus and other postoperative complications on mortality. p Values <0.05 were considered significant. RESULTS: We identified 32,392 patients who underwent non-emergent colectomy. Longer length of stay, higher complication, reoperation, readmission, and mortality rates were identified in patients with ileus (p < 0.001 for all). Overall, 59% of patients with ileus had at least one adverse outcome, compared with 25% of patients without ileus (p < 0.001). Patients who developed ileus in the absence of other complications had an identical mortality rate to patients without ileus (1%). Additional complications led to incremental increases in mortality rates. CONCLUSIONS: Patients with ileus and multiple complications are at significantly increased risk for adverse outcomes. Older patients with more comorbidity were found to be at risk for adverse outcomes in addition to ileus, begging the question of whether these patients may benefit from preoperative optimization.

Characterizing readmission in ulcerative colitis patients undergoing restorative proctocolectomy.

BACKGROUND: Postoperative readmissions increase costs and affect patient quality of life. Ulcerative colitis (UC) patients are at a high risk for hospital readmission following restorative proctocolectomy (RP). OBJECTIVE: The objective of this study is to characterize UC patients undergoing RP and identify causes and risk factors for readmission. DESIGN: A retrospective review of a prospectively maintained institutional database was performed. Postoperative readmission rates and reasons for readmission were examined following RP. Univariate and multivariate analyses were performed to evaluate for risk factors associated with readmission. RESULTS: Of 533 patients who met our inclusion criteria, 18.2 % (n = 97) were readmitted within 30 days while 22.7 % (n = 121) were readmitted within 90 days of stage I of RP. Younger patient age (OR 1.825, 95 % CI 1.139-2.957), laparoscopic approach (OR 1.943, 95 % CI 1.217-3.104), and increased length of initial stay (OR 1.155, 95 % CI 1.090-1.225) were all associated with 30-day readmission. The most common reason for readmission was dehydration/ileus/partial bowel obstruction, with 10 % of patients readmitted for this reason within 30 days. CONCLUSIONS: Patients undergoing restorative proctocolectomy are at high risk for readmission, particularly following the first stage of the operation. Novel treatment pathways to prevent ileus and dehydration as an outpatient may decrease the rates of readmission following RP.