Effect of Obesity on Risk of Hospitalization, Surgery, and Serious Infection in Biologic-Treated Patients With Inflammatory Bowel Diseases: A CA-IBD Cohort Study

INTRODUCTION

Obesity is variably associated with treatment response in biologic-treated patients with inflammatory bowel diseases (IBD). We evaluated the association between obesity and risk of hospitalization, surgery, or serious infections in patients with IBD in new users of biologic agents in a large, multicenter, electronic health record (EHR)-based cohort (CA-IBD).

METHODS

We created an EHR-based cohort of adult patients with IBD who were new users of biologic agents (tumor necrosis factor [TNF-α] antagonists, ustekinumab, and vedolizumab) between January 1, 2010, and June 30, 2017, from 5 health systems in California. Patients were classified as those with normal body mass index (BMI), overweight, or obese based on the World Health Organization classification. We compared the risk of all-cause hospitalization, IBD-related surgery, or serious infections among patients with obesity vs those overweight vs those with normal BMI, using Cox proportional hazard analyses, adjusting for baseline demographic, disease, and treatment characteristics.

RESULTS

Of 3,038 biologic-treated patients with IBD (69% with Crohn's disease and 76% on TNF-α antagonists), 28.2% (n = 858) were overweight, and 13.7% (n = 416) were obese. On a follow-up after biologic initiation, obesity was not associated with an increased risk of hospitalization (adjusted hazard ratio [aHR] vs normal BMI, 0.90; [95% confidence interval, 0.72-1.13]); IBD-related surgery (aHR, 0.62 [0.31-1.22]); or serious infection (aHR, 1.11 [0.73-1.71]). Similar results were observed on stratified analysis by disease phenotype (Crohn's disease vs ulcerative colitis) and index biologic therapy (TNF-α antagonists vs non-TNF-α antagonists).

DISCUSSION

In a multicenter, EHR-based cohort of biologic-treated patients with IBD, obesity was not associated with hospitalization, surgery, or serious infections. Further studies examining the effect of visceral obesity on patient-reported and endoscopic outcomes are needed.

Current trends in nonoperative management for rectal adenocarcinoma: An unequal playing field?

BACKGROUND AND OBJECTIVES

Increasing evidence suggests patient-oriented benefits of nonoperative management (NOM) for rectal cancer. However, vigilant surveillance requires excellent access to care. We sought to examine patient, socioeconomic, and facility-level factors associated with NOM over time.

METHODS

Using the National Cancer Database (2006-2017), we examined patients with Stage II-III rectal adenocarcinoma, who received neoadjuvant chemoradiation and received NOM versus surgery. Factors associated with NOM were assessed using multivariable logistic regression with backward stepwise selection.

RESULTS

There were 59,196 surgical and 8520 NOM patients identified. NOM use increased from 12.9% to 15.9% between 2006 and 2017. Patients who were Black (adjusted odds ratio [aOR]: 1.36, 95% confidence interval [CI]: 1.26-1.47), treated at community cancer centers (aOR: 1.22, 95% CI: 1.12-1.30), without insurance (aOR: 1.87, 95% CI: 1.68-2.09), and with less education (aOR: 1.53, 95% CI: 1.42-1.65) exhibited higher odds of NOM. Patients treated at high-volume centers (aOR: 0.79, 95% CI: 0.74-0.84) and those who traveled >25.6 miles for care (aOR: 0.59, 95% CI: 0.55-0.64) had lower odds of NOM.

CONCLUSIONS

Vulnerable groups who traditionally have difficulty accessing comprehensive cancer care were more likely to receive NOM, suggesting that healthcare disparities may be driving utilization. More research is needed to understand NOM decision-making in rectal cancer treatment.

Factors associated with refusing surgery versus planned nonoperative management for rectal cancer

BACKGROUND

Increasingly, patients with rectal cancer receive nonoperative management. A growing body of retrospective evidence supporting the safety of this approach has likely contributed to its growing popularity. However, patients may also undergo nonoperative management because of refusal of surgical resection. We hypothesize that patients who refuse surgery are more likely to be from groups who traditionally face barriers accessing care.

METHODS

We used the National Cancer Database (2006-2017) to analyze patients with nonmetastatic rectal adenocarcinoma who underwent nonoperative management following radiation. We identified 2 groups: (1) planned nonoperative management and (2) nonoperative management because of refusal of surgery. We performed logistic regression to compare the groups along patient, socioeconomic, and facility-level factors.

RESULTS

In total, 9,613 and 2,039 patients were included in the planned nonoperative management and refused nonoperative management groups, respectively. Of the total study cohort (ie, planned nonoperative management + refused nonoperative management), 21% of these patients diagnosed in 2017 underwent refused nonoperative management, versus 12% in 2006. Patients who were Black (adjusted odds ratio 1.47, 95% confidence interval 1.26-1.71) or Asian/Pacific Islander (adjusted odds ratio 1.51, 95% confidence interval 1.18-1.92), age ≥65 years (adjusted odds ratio 1.55, 95% confidence interval 1.37-1.77), with more advanced disease stage (stage III adjusted odds ratio 1.30, 95% confidence interval 1.10-1.53), and government insurance (adjusted odds ratio 1.19, 95% confidence interval 1.04-1.36) were associated with increased utilization of refused nonoperative management. Conversely, lower education (adjusted odds ratio 0.62, 95% confidence interval 0.50-0.76) and female sex (adjusted odds ratio 0.88, 95% confidence interval 0.79-0.97) were associated with planned nonoperative management.

CONCLUSION

Our findings suggest that the refused nonoperative management group is demographically distinct. Outreach efforts to better understand the rationale behind patient decision making in rectal cancer will be paramount to ensuring appropriate implementation of nonoperative management.

Robotic left-stapled total intracorporeal bowel anastomosis versus stapled partial extracorporeal anastomosis: operative technical description and outcomes

Background

Although there is extensive literature on robotic total intracorporeal anastomosis (TICA) for right colon resection, left total ICA using the da Vinci Xi robotic platform has only been described in short case series previously. In this study, we report on the largest cohort of robotic left total ICA, provide a description of our institution’s techniques, and compare outcomes to robotic left partial extracorporeal anastomosis (PECA).

Methods

Patients who underwent robotic left colectomy for any underlying pathology from July 1, 2016 through April 30, 2020 were identified by procedure code. A technical description is provided for two unique techniques performed at our institution. Outcomes included operative time, length of stay, supply cost, post-operative ileus, post-operative morbidity and mortality and need for complete mobilization of the splenic flexure.

Results

From a review of our institution’s data, 83 robotic TICA cases were identified and 76 robotic PECA cases were identified. Common procedures included low anterior resection, sigmoidectomy, left hemicolectomy, and rectopexy with resection. TICA was associated with significantly shorter intraoperative time compared to PECA.

Conclusions

Our series shows that TICA is a safe and feasible technique that does not increase the risk of adverse outcomes. Using either the anvil-forward or anvil-backward technique, we were able to reliably reproduce this method in a total of 83 patients undergoing left colon resection for either benign or malignant diseases.

Supplementary Information

The online version contains supplementary material available at 10.1007/s00464-022-09048-6.

Venous Thromboembolism and Pulmonary Embolism: Strategies for Prevention and Management

Perioperative venous thromboembolism (VTE) is a common complication within the surgical patient population. Perioperative mechanical and chemoprophylaxis have been shown to reduce the incidence of both deep venous thrombosis and pulmonary embolism. Prophylactic regimen must be tailored to the patient's individual risk factors as well as the nature of the procedure. In the event of VTE, treatment most commonly includes long-term anticoagulation, whereas more severe cases may require lytic or mechanical interventions.

Cost Effectiveness of Watch and Wait Versus Resection in Rectal Cancer Patients with Complete Clinical Response to Neoadjuvant Chemoradiation

BACKGROUND

Watch and wait (WW) protocols have gained increasing popularity for patients diagnosed with locally advanced rectal cancer and presumed complete clinical response after neoadjuvant chemoradiation. While studies have demonstrated comparable survival and recurrence rates between WW and radical surgery, the decision to undergo surgery has significant effects on patient quality of life. We sought to conduct a cost-effectiveness analysis comparing WW with abdominoperineal resection (APR) and low anterior resection (LAR) among patients with stage II/III rectal cancer.

METHODS

In this comparative-effectiveness study, we built Markov microsimulation models to simulate disease progression, death, costs, and quality-adjusted life-years (QALYs) for WW or APR/LAR. We assessed cost effectiveness using the incremental cost-effectiveness ratio (ICER), with ICERs under $100,000/QALY considered cost effective. Probabilities of disease progression, death, and health utilities were extracted from published, peer-reviewed literature. We assessed costs from the payer perspective.

RESULTS

WW dominated both LAR and APR at a willingness to pay (WTP) threshold of $100,000. Our model was most sensitive to rates of distant recurrence and regrowth after WW. Probabilistic sensitivity analysis demonstrated that WW was the dominant strategy over both APR and LAR over 100% of iterations across a range of WTP thresholds from $0-250,000.

CONCLUSIONS

Our study suggests WW could reduce overall costs and increase effectiveness compared with either LAR or APR. Additional clinical research is needed to confirm the clinical efficacy and cost effectiveness of WW compared with surgery in rectal cancer.

State-of-the-art surgery for ulcerative colitis

Ulcerative colitis (UC) is an autoimmune-mediated colitis which can present in varying degrees of severity and increases the individual’s risk of developing colon cancer. While first-line treatment for UC is medical management, surgical treatment may be necessary in up to 25–30% of patients. With an increasing armamentarium of biologic therapies, patients are presenting for surgery much later in their course, and careful understanding of the complex interplay of the disease, its management, and the patient’s overall health is necessary when considering he appropriate way in which to address their disease surgically. Surgery is generally a total proctocolectomy either with pelvic pouch reconstruction or permanent ileostomy; however, this may need to be spread across multiple procedures given the complexity of the surgery weighed against the overall state of the patient’s health. Minimally invasive surgery, employing either laparoscopic, robotic, or transanal laparoscopic approaches, is currently the preferred approach in the elective setting. There is also some emerging evidence that appendectomy may delay the progression of UC in some individuals. Those who treat these patients surgically must also be familiar with the numerous potential pitfalls of surgical intervention and have plans in place for managing problems such as pouchitis, cuffitis, and anastomotic complications.

Local excision versus radical resection in patients with rectal neuroendocrine tumours: a propensity score match analysis

BACKGROUND

The rectum is a common site for neuroendocrine tumours of the gastrointestinal tract. Diagnosis of these tumours has been increasing in recent years, highlighting the need to better define treatment options for patients with rectal neuroendocrine tumours (rNETs).

METHODS

We performed a retrospective analysis using the National Cancer Database (2004-2014) to compare overall survival (OS) between local excision (LE) and radical resection (RR). To minimize bias, we performed three propensity score-matched comparisons stratified by tumour size: <10 mm, 10-20 mm, >20 mm. We compared OS by Kaplan-Meier analysis. We also examined margin status and postoperative outcomes for each comparison.

RESULTS

A total of 12 996 patients underwent surgical treatment for rNET. There was no significant difference in probability of 10-year OS between LE and RR for patients with tumours <10 mm (88.6% versus 83.8%, P = 0.631, respectively) and tumours 10-20 mm (69.5% versus 69.3%, P = 0.226, respectively). In patients with tumours >20 mm, probability of 10-year OS was significantly longer in the LE group (76.5% versus 37.0%, P < 0.001). For all tumour sizes <10 mm and >20 mm, RR had significantly higher rates of 30-day readmission and negative margins. In subset analysis, there was no difference in OS for patients with positive margins after LE versus negative margins after RR for all tumour size groups.

CONCLUSIONS

Our findings suggest that LE is a reasonable treatment option in patients with rNETs, especially for patients with high perioperative risk. Limitations to this study include its retrospective nature and inability to analyse surgeon decision-making.

Synchronous metastatic colon cancer and the importance of primary tumor laterality - A National Cancer Database analysis of right- versus left-sided colon cancer

BACKGROUND

The role of laterality for patients with synchronous metastatic colon cancer (SMCC) is not well-defined.

METHODS

Using the National Cancer Database (2010-2015), we compared patients with metastatic right- (RCC) versus left-sided colon cancer (LCC). We performed Kaplan-Meier analysis to compare overall survival (OS) for each metastatic site and utilized adjusted Cox proportional hazard analysis to identify predictors of OS.

RESULTS

Patients with RCCs were more likely to be older, female, and have more comorbidities. LCCs were more likely to metastasize to liver and lung, whereas RCCs were more likely to metastasize to peritoneum and brain. There was equal likelihood to metastasize to bone. OS was significantly longer for LCCs for all metastatic sites. After controlling for multiple variables, RCC (HR 1.426, p < 0.001) remained an independent predictor of worse OS compared to LCC.

CONCLUSIONS

Laterality of the primary tumor plays an important role in outcomes for patients with SMCC.

Using machine learning to construct nomograms for patients with metastatic colon cancer

AIM

Patients with synchronous colon cancer metastases have highly variable overall survival (OS), making accurate predictive models challenging to build. We aim to use machine learning to more accurately predict OS in these patients and to present this predictive model in the form of nomograms for patients and clinicians.

METHODS

Using the National Cancer Database (2010-2014), we identified right colon (RC) and left colon (LC) cancer patients with synchronous metastases. Each primary site was split into training and testing datasets. Nomograms predicting 3- year OS were created for each site using Cox proportional hazard regression with lasso regression. Each model was evaluated by both calibration (comparison of predicted vs observed OS) and validation (degree of concordance as measured by the c-index) methodologies.

RESULTS

A total of 11 018 RC and 8346 LC patients were used to construct and validate the nomograms. After stratifying each model into five risk groups, the predicted OS was within the 95% CI of the observed OS in four out of five risk groups for both the RC and LC models. Externally validated c-indexes at 3 years for the RC and LC models were 0.794 and 0.761, respectively.

CONCLUSIONS

Utilization of machine learning can result in more accurate predictive models for patients with metastatic colon cancer. Nomograms built from these models can assist clinicians and patients in the shared decision-making process of their cancer care.

Better characterization of operation for ulcerative colitis through the National surgical quality improvement program: A 2-year audit of NSQIP-IBD

INTRODUCTION

There is little consensus of quality measurements for restorative proctocolectomy with ileal pouch-anal anastomosis(RPC-IPAA) performed for ulcerative colitis(UC). The National Surgical Quality Improvement Program(NSQIP) cannot accurately classify RPC-IPAA staged approaches. We formed an IBD-surgery registry that added IBD-specific variables to NSQIP to study these staged approaches in greater detail.

METHODS

We queried our validated database of IBD surgeries across 11 sites in the US from March 2017 to March 2019, containing general NSQIP and IBD-specific perioperative variables. We classified cases into delayed versus immediate pouch construction and looked for independent predictors of pouch delay and postoperative Clavien-Dindo complication severity.

RESULTS

430 patients received index surgery or completed pouches. Among completed pouches, 46(28%) and 118(72%) were immediate and delayed pouches, respectively. Significant predictors for delayed pouch surgery included higher UC surgery volume(p = 0.01) and absence of colonic dysplasia(p = 0.04). Delayed pouch formation did not significantly predict complication severity.

CONCLUSIONS

Our data allows improved classification of complex operations. Curating disease-specific variables allows for better analysis of predictors of delayed versus immediate pouch construction and postoperative complication severity.

SHORT SUMMARY

We applied our previously validated novel NSIP-IBD database for classifying complex, multi-stage surgical approaches for UC to a degree that was not possible prior to our collaborative effort. From this, we describe predictive factors for delayed pouch formation in UC RPC-IPAA with the largest multicenter effort to date.

Predicting Overall Survival in Patients with Metastatic Rectal Cancer: a Machine Learning Approach

BACKGROUND

A significant proportion of patients with rectal cancer will present with synchronous metastasis at the time of diagnosis. Overall survival (OS) for these patients are highly variable and previous attempts to build predictive models often have low predictive power, with concordance indexes (c-index) less than 0.70.

METHODS

Using the National Cancer Database (2010-2014), we identified patients with synchronous metastatic rectal cancer. The data was split into a training dataset (diagnosis years 2010-2012), which was used to build the machine learning model, and a testing dataset (diagnosis years 2013-2014), which was used to externally validate the model. A nomogram predicting 3-year OS was created using Cox proportional hazard regression with lasso penalization. Predictors were selected based on clinical significance and availability in NCDB. Performance of the machine learning model was assessed by c-index.

RESULTS

A total of 4098 and 3107 patients were used to construct and validate the nomogram, respectively. Internally validated c-indexes at 1, 2, and 3 years were 0.816 (95% CI 0.813-0.818), 0.789 (95% CI 0.786-0.790), and 0.778 (95% CI 0.775-0.780), respectively. External validated c-indexes at 1, 2, and 3 years were 0.811, 0.779, and 0.778, respectively.

CONCLUSIONS

There is wide variability in the OS for patients with metastatic rectal cancer, making accurate predictions difficult. However, using machine learning techniques, more accurate models can be built. This will aid patients and clinicians in setting expectations and making clinical decisions in this group of challenging patients.

General surgery training in the era of robotic surgery: a qualitative analysis of perceptions from resident and attending surgeons

BACKGROUND

The use of the surgical robot has increased annually since its introduction, especially in general surgery. Despite the tremendous increase in utilization, there are currently no validated curricula to train residents in robotic surgery, and the effects of robotic surgery on general surgery residency training are not well defined. In this study, we aim to explore the perceptions of resident and attending surgeons toward robotic surgery education in general surgery residency training.

METHODS

We performed a qualitative thematic analysis of in-person, one-on-one, semi-structured interviews with general surgery residents and attending surgeons at a large academic health system. Convenient and purposeful sampling was performed in order to ensure diverse demographics, experiences, and opinions were represented. Data were analyzed continuously, and interviews were conducted until thematic saturation was reached, which occurred after 20 residents and seven attendings.

RESULTS

All interviewees agreed that dual consoles are necessary to maximize the teaching potential of the robotic platform, and the importance of simulation and simulators in robotic surgery education is paramount. However, further work to ensure proper access to simulation resources for residents is necessary. While most recognize that bedside-assist skills are essential, most think its educational value plateaus quickly. Lastly, residents believe that earlier exposure to robotic surgery is necessary and that almost every case has a portion that is level-appropriate for residents to perform on the robot.

CONCLUSIONS

As robotic surgery transitions from novelty to ubiquity, the importance of effective general surgery robotic surgery training during residency is paramount. Through in-depth interviews, this study provides examples of effective educational tools and techniques, highlights the importance of simulation, and explores opinions regarding the role of the resident in robotic surgery education. We hope the insights gained from this study can be used to develop and/or refine robotic surgery curricula.

Making the Jump: A Qualitative Analysis on the Transition From Bedside Assistant to Console Surgeon in Robotic Surgery Training

OBJECTIVE

To determine barriers associated with the transition from bedside assistant to console surgeon for general surgery residents in the era of robotic surgery in general surgery training.

DESIGN

Qualitative thematic analysis using one-on-one interviews of general surgery residents and attendings conducted between June 2018 and February 2019.

SETTING

An urban, academic, multihospital general surgery residency program with a robust robotic surgery program.

PARTICIPANTS

Convenient and purposeful sampling was performed to ensure a variety of resident graduate-years and attending subspecialties were represented. Sample size was determined by data saturation, which occurred after 20 resident and 7 attending interviews.

RESULTS

Residents identified the low volume of general surgery robotic cases, the infrequency of exposure to robotic surgery, and attending comfort with robotic surgery (and with teaching on the robot) as potential barriers in the transition from bedside assistant to console surgeon. Residents had to find a replacement bedside assistant in order to be the console surgeon, which was challenging. In addition, residents felt that the current culture surrounding robotic surgery is very hierarchal, limiting their exposure. Attendings' trust in the residents' console skills was a major determining factor in allowing residents on the console.

CONCLUSIONS

Most robotic surgery education curricula are sequential, requiring the resident to progress from bedside assistant to console surgeon. Unfortunately, there are many potential barriers for residents in the transition from bedside assistant to console surgeon. Some barriers apply to general surgery training overall, but are amplified in robotic surgery, while others are unique to robotic surgery education. Recognition of, and rectifying, these barriers may increase resident participation as the console surgeon.

The ACS National Surgical Quality Improvement Program-Inflammatory Bowel Disease Collaborative: Design, Implementation, and Validation of a Disease-specific Module

BACKGROUND

Surgery for inflammatory bowel disease (IBD) involves a complex interplay between disease, surgery, and medications, exposing patients to increased risk of postoperative complications. Surgical best practices have been largely based on single-institution results and meta-analyses, with multicenter clinical data lacking. The American College of Surgeons National Surgical Quality Improvement Project (ACS-NSQIP) has revolutionized the way in which large-volume surgical outcomes data have been collected. Our aim was to employ the ACS-NSQIP to collect disease-specific variables relevant to surgical outcomes in IBD.

STUDY DESIGN

A collaborative of 13 high-volume IBD surgery centers was convened to collect 5 IBD-specific variables in NSQIP. Variables included biologic and immunomodulator medications usage, ileostomy utilization, ileal pouch anastomotic technique, and colonic dysplasia/neoplasia. A sample of the Surgical Clinical Reviewer collected data was validated by a colorectal surgeon at each institution, and kappa's agreement statistics generated.

RESULTS

Over 1 year, data were collected on a total of 956 cases. Overall, 41.4% of patients had taken a biologic agent in the 60 days before surgery. The 2 most commonly performed procedures were laparoscopic ileocolic resections (159 cases) and subtotal colectomies (151 cases). Overall, 56.8% of cases employed an ileostomy, and 134 ileal pouches were constructed, of which 92.4% used stapled technique. A sample of 214 (22.4%) consecutive cases was validated from 8 institutions. All 5 novel variables were shown to be reliably collected, with excellent agreement for 4 variables (kappa ≥ 0.70) and very good agreement for the presence of colonic dysplasia (kappa = 0.68).

CONCLUSION

We report the results of the initial year of implementation of the first disease-specific collaborative within NSQIP. The selected variables were demonstrated to be reliably collected, and this collaborative will facilitate high-quality, large case-volume research specific to the IBD patient population.