Ulcerative colitis (UC) is an inflammatory condition that generally affects the rectum and extends proximally into the colon in a continuous, distal-to-proximal pattern. Surgical resection (total proctocolectomy) is the only cure for UC and is often necessary in managing complicated or refractory disease. However, recent advances in biologically targeted therapies have resulted in improved disease control, and surgery is required in only a fraction of cases. This ever-increasing array of options for medical management has added complexity to surgical decision-making. In some circumstances, the added time required to ensure failure of medical therapy can delay colectomy in patients who will ultimately need it. Indeed, many patients with severe disease undergo trials of multiple medical therapies prior to considering surgery. In severe cases of UC, continued medical management has been associated with a delay to surgical intervention and higher rates of morbidity and mortality. Biomarkers represent a burgeoning field of research, particularly in inflammatory bowel disease and cancer. This review seeks to highlight the different possible settings for surgery in UC and the role various biomarkers might play in each.

Introduction

The discovery of activating KIT and PDGFRα mutations in gastrointestinal stromal tumors (GISTs) represented a milestone as it allowed clinicians to use tyrosine kinase inhibitors, like imatinib, to treat this sarcoma. Although surgery remains the only potentially curative treatment, patients who undergo complete resection may still experience local recurrence or distant metastases. Therapeutic strategies that combine surgical resection and adjuvant imatinib may represent the best treatment to maximize patient outcomes. In addition to the use of imatinib in the adjuvant and metastatic settings, neoadjuvant imatinib, employed as a cytoreductive therapy, can decrease tumor volume, increase the probability of complete resection, and may reduce surgery-related morbidities. Thus, selected patients with metastatic disease may be treated with a combination of preoperative imatinib and metastasectomy. However, it is critical that patients with GIST be evaluated by a multidisciplinary team to coordinate surgery and targeted therapy in order to maximize clinical outcomes.

Discussion

Following a systematic literature review, we describe the presentation, diagnosis, and treatment of GIST, with a discussion of the risk assessment for imatinib therapy. The application of surgical options, combined with adjuvant/neoadjuvant or perioperative imatinib, and their potential impact on survival for patients with primary, recurrent, or metastatic GIST are discussed.

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.

Background

We identified recently esophageal cancer related gene-4 (ECRG4) as a candidate cytokine that is expressed on the surface of quiescent polymorphonuclear leukocytes (PMNs) and shed in response to ex vivo treatment with lipopolysaccharide. To investigate the potential biologic relevance of changes in cell surface ECRG4 in human samples, we performed a pilot study to examine a population of burn patients in whom blood could be analyzed prospectively. We hypothesized that cutaneous burn injury would alter cell surface expression of ECRG4 on PMNs.

Methods

Patients admitted with more than 20% total burn surface area (TBSA) (n = 10) had blood collected at the time of admission and weekly thereafter. For comparison, blood was obtained from a control group of healthy human volunteers (n = 4). We used flow cytometry to measure changes in ECRG4(+) PMNs from patients during recovery from injury. Esophageal cancer related gene-4 expression at each time point was compared with the patient's clinical status based on a Multiple Organ Dysfunction (MOD) score.

Results

Esophageal cancer related gene-4 was detected on the PMN surface of cells collected from healthy volunteers, however, within 48 h of admission after burn injury (n = 10 patients), the number of PMNs with cell surface ECRG4 was decreased. Esophageal cancer related gene-4 expression in PMNs was re-established over the course of patient recovery, unless complications occurred. In this case, the decrease in cell surface ECRG4(+) PMNs preceded the clinical diagnosis of infectious complications and was reflected by increased organ injury scores.

Conclusion

From a small sample set, we were able to determine that PMN cell surface ECRG4 expression was decreased after burn injury and returned to baseline during recovery from injury. Although larger studies are needed to define the role of ECRG4 in human PMNs further, this report is the first assessment of cell surface ECRG4 protein in a patient population to support analogous findings in animal studies.

Background

Common colorectal procedures that require access to all quadrants of the abdomen are subtotal colectomy (STC) and total proctocolectomy (TPC). These are frequently performed with a surgical robot, but multiquadrant operations have unique challenges during robot-assisted surgery.

Methods

Patients who underwent robotic STC or TPC with the da Vinci Xi surgical robot at our institution from July 1, 2016 through June 30, 2019 were identified by diagnosis and procedure codes. A technical description is provided for the techniques utilized at our institution. Outcomes included operative times (OT), supply cost and length of stay. Associated morbidity and mortality was also analyzed.

Results

From a review of our institution's robotic surgery data, 37 cases were identified that utilized the described technique. Of these cases, 21 were robotic STC and 16 were TPC. Total mean OT was 276.86 min (SD ± 119.49). Mean OT was further analyzed by year, which demonstrated an overall decrease in OT from 350.91 min (SD ± 46.38) in 2016 to 221.43 min (SD ± 16.46) in 2018 (p = 0.008). A total of 21 cases were performed prior to 2018. Overall OT for STC was 222.81 min (SD ± 14.54) compared to overall TPC OT 347.81 min (SD ± 34.35). Median length of stay was 5 days [25th and 75th percentiles 4, 6, respectively]. There was no 30-day mortality and only one return to operating room for mesenteric bleeding. There was a low risk of mortality associated with this technique.

Conclusions

The current study provides the largest cohort of patients assessed who have undergone multiquadrant robotic STC or TPC. The study provides a detailed description of the technique utilized at our institution. There was no associated 30-day mortality and a low risk of morbidity. The data suggest that the learning curve for improved operative time is between 15 and 20 cases.

Background

Rectal neuroendocrine tumors comprise 20% of neuroendocrine tumors in the alimentary tract, but there is controversy surrounding the optimal management of this disease. The purpose of this study is to better define treatment for patients with rectal neuroendocrine tumors.

Methods

Using the National Cancer Database, we analyzed patients with rectal neuroendocrine tumors between 2004 and 2015. Patients with metastatic disease and missing treatment data were excluded. We examined overall survival stratified by tumor size, treatment type, and presence of positive lymph nodes using Kaplan-Meier analysis with log-rank test. Cox proportional hazard regression model was performed to identify factors associated with overall survival.

Results

In total, 17,448 patients with rectal neuroendocrine tumors were identified; 16,531 of these patients met inclusion criteria. The majority of patients had tumors ≤ 10 mm (9216 patients, 79.8%), and approximately 90% underwent local excision. The probability of 5-year overall survival was significantly higher for patients with smaller tumors (≤ 10 mm: 94.1% 11-20 mm: 85.7%, > 20 mm: 71.8%; p < 0.001) and those with no positive lymph nodes (91.4% versus 53.3%, p < 0.001). The probability of 5-year overall survival differed based on treatment modality (local excision: 93.6%, radical resection: 79.1%, observation alone: 77.1%; p < 0.001). On multivariable Cox regression, when compared to local excision, radical resection was not associated with a difference in overall survival but observation alone was associated with significantly worse OS (HR = 2.750, p < 0.001).

Conclusions

There is a significant difference in overall survival between patients who underwent local excision versus observation alone. Excision of the tumor should be offered to all patients with rectal neuroendocrine tumors who are appropriate surgical candidates, regardless of the tumor size.

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.

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.

Purpose

Colorectal cancer (CRC) is a leading cause of international morbidity and is the second highest cause of cancer-related mortality in the world. The purpose of this study was to investigate the relationship between international health care spending on CRC mortality over time.

Methods

This is a retrospective study using a publicly available data from the WHO Global Health Observatory database. General estimating equations were used to analyze the relationship between total health care expenditure per capita (THEpc) and CRC mortality at the country level. The primary predictors of interest were quartiles of THEpc. Other exposure variables included gross domestic product per capita (GDPpc), smoking (% of adult population smoking), physician density (per 10,000), and time.

Results

Mortality decreased significantly from 2000 to 2016 (coefficient [95% CI], -2.2 [-3.3 to -1.1]; P < .001). THEpc, GDPpc, time, and percentage of adult population smoking were significant predictors of CRC mortality. Patients in the top two quartiles of THEpc had 3% higher rates of CRC mortality compared with countries in Q1 THEpc (Q3: 3.4 [1.9-4.8], P < .001; Q4: 3.2 [1.4-5.0], P = .001). Similar trends were seen in GDPpc (Q4: 3.2 [1.4-5.0], P = .001; Q3: 3.4 [1.9-4.8], P < .001; Q2: 1.7 [0.7-2.6], P < .001; Q1: reference).

Conclusion

Overall, mortality decreased significantly over the study period. Countries with higher health expenditures and higher gross domestic products experienced higher rates of CRC mortality. Further research will be necessary to determine the cause for this, but we postulate that it may be a result of more robust diagnostic and follow-up methods in countries with more resources.

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.