Jonathan A. Laryea

Venous thromboembolism prophylaxis.

Venous thromboembolism (VTE) can occur after major general surgery. Pulmonary embolism is recognized as the most common identifiable cause of death in hospitalized patients in the United States. The risk of deep venous thrombosis (DVT) and pulmonary embolism (PE) is higher in colorectal surgical procedures compared with general surgical procedures. The incidence of venous thromboembolism in this population is estimated to be 0.2 to 0.3%. Prevention of VTE is considered a patient-safety measure in most mandated quality initiatives. The measures for prevention of VTE include mechanical methods (graduated compression stockings and intermittent pneumatic compression devices) and pharmacologic agents. A combination of mechanical and pharmacologic methods produces the best results. Patients undergoing surgery should be stratified according to their risk of VTE based on patient risk factors, disease-related risk factors, and procedure-related risk factors. The type of prophylaxis should be commensurate with the risk of VTE based on the composite risk profile.

Racial disparity in colorectal cancer: the role of equal treatment.

BACKGROUND: Racial disparity exists in colorectal cancer outcomes. The reasons for this are multifactorial. OBJECTIVE: The aim of this study was to evaluate the role of equal treatment of blacks and whites in the elimination of racial disparity in colorectal cancer outcomes. DESIGN: A retrospective cohort study of 878 patients with colorectal cancer diagnosed between 1998 and 2008 was done at a University tertiary referral center. Demographic variables including age, sex, and race were abstracted. Tumor-specific variables including American Joint Committee on Cancer stage, anatomic tumor location, vital status, and survival were obtained. Treatment-specific variables including surgery, chemotherapy, radiotherapy, and follow-up were also obtained. Racial differences in these variables were studied and their effect on overall survival was determined by using univariate and multivariate analyses. The findings were then compared with previous data from our institution. SETTING: University tertiary referral center. MAIN OUTCOME MEASURES: The primary outcomes measured were overall survival and cancer-specific mortality. RESULTS: A total of 878 patients met the inclusion criteria, 186 (21.2%) of whom were black. Blacks were significantly younger at diagnosis in comparison with whites, with a median (quartiles) age of 55 years (28–87) compared with 59 years (23–94) (p = 0.0012). Equal proportions of blacks (78.5%) and whites (79.2%) underwent surgery (p = 0.84), similar proportions of blacks (55.4%) and whites (60.8%) received chemotherapy (p = 0.18), and similar proportions of blacks (17.2%) and whites (20.5%) received radiation therapy (p = 0.31). There was no difference in overall survival or cancer-specific mortality between the 2 racial groups. Univariate analysis showed American Joint Committee on Cancer stage and surgery as the only statistically significant factors for overall survival. On multivariate analysis, stage, surgery, and chemotherapy were the only statistically significant factors. Race was not an independent determinant of survival. CONCLUSIONS: There were no differences in overall survival and cancer-related mortality between blacks and whites, and this may have resulted from identical treatment. The previously noted disparities in treatment and overall survival at our institution have disappeared.

Ipilimumab-induced colonic perforation

Biologic immune modulators such as ipilimumab have demonstrated the efficacy against metastatic melanoma. We present a recent case of a 52-year-old male who initially developed mild colitis following the initiation of ipilimumab treatment for metastatic melanoma. Despite initial improvement with immediate cessation of drug and initiation of high-dose steroid therapy his clinical condition worsened and the patient presented to our facility in extremis from colonic perforation. Following an extended right hemicolectomy his postoperative period was extended due to continued symptomatic enteritis. After 3 weeks colonoscopy revealed that the autoimmune event had begun to subside; his condition improved, resulting in discharge. We discuss this particular side effect with respect to ipilimumab adjuvant therapy in melanoma.

MR Evaluation of Rectal Cancer: Current Concepts

Magnetic resonance imaging has become more frequently utilized for staging, preoperative planning, and post-neoadjuvant evaluation of rectal cancer. It offers detailed resolution of the layers of the rectal wall, visualization of the mesorectal fascia, and identification of locoregional nodal involvement. Many advances have been made since the original protocols and include the use of phased-array coils, orthogonally obtained images and 3-dimensional sequences, the use of diffusion-weighted and perfusion protocols to better evaluate the tumor before and after neoadjuvant therapy, and the development of techniques to better evaluate metastatic nodes. Magnetic resonance imaging shows similar accuracy to endorectal ultrasound when staging and offers a less invasive technique that is not limited by patient discomfort or decreased luminal size. This article is meant to provide an update on the recent advances in rectal cancer imaging while addressing the controversial issues that exist in staging, technique, and imaging protocol.

Peritoneal seeding following incomplete resection of mixed epithelial stromal tumor of the kidney: First case report

Mixed epithelial stromal tumor (MEST) is rare and typically benign renal cystic neoplasm that cannot be clinically distinguished from cystic renal cell carcinoma. Its mainstay course of diagnosis and treatment remains surgical excision. Recurrence and malignant transformation is rare but has previously been described. To our best knowledge, we present the first case of peritoneal seeding resulting in a paracolonic MEST following incomplete resection in a patient with benign MEST. This signifies a new pathological behavior for MEST, predominantly, a benign kidney tumor. In addition, documentation with more cases of MEST is needed to further understand its pathogenesis, clinical behavior, malignant potential, and optimal management.

Staple Line/Anastomotic Reinforcement and Other Adjuncts: Do They Make a Difference?

Since the development of the stapled intestinal anastomosis, efforts have been aimed at reducing complications and standardizing methods. The main complications associated with stapled anastomoses include bleeding, device failure, and anastomotic failure (leaks and strictures). These complications are associated with increased cost of care, increase in cancer recurrence, decreased overall survival, poor quality of life, and in some cases the need for further procedures including a diverting ostomy. Reducing these complications therefore has important implications. To this end, techniques to reduce the incidence of anastomotic complications have been the focus of many investigators. In this review, we summarize the current staple line reinforcement technology as well as other adjunctive measures, and specifically discuss the role of biologic materials in this realm.

Quantitative analysis of ex vivo colorectal epithelium using an automated feature extraction algorithm for microendoscopy image data

Abstract. Qualitative screening for colorectal polyps via fiber bundle microendoscopy imaging has shown promising results, with studies reporting high rates of sensitivity and specificity, as well as low interobserver variability with trained clinicians. A quantitative image quality control and image feature extraction algorithm (QFEA) was designed to lessen the burden of training and provide objective data for improved clinical efficacy of this method. After a quantitative image quality control step, QFEA extracts field-of-view area, crypt area, crypt circularity, and crypt number per image. To develop and validate this QFEA, a training set of microendoscopy images was collected from freshly resected porcine colon epithelium. The algorithm was then further validated on ex vivo image data collected from eight human subjects, selected from clinically normal appearing regions distant from grossly visible tumor in surgically resected colorectal tissue. QFEA has proven flexible in application to both mosaics and individual images, and its automated crypt detection sensitivity ranges from 71 to 94% despite intensity and contrast variation within the field of view. It also demonstrates the ability to detect and quantify differences in grossly normal regions among different subjects, suggesting the potential efficacy of this approach in detecting occult regions of dysplasia.

Abdominal Approaches to Rectal Prolapse

Abstract Rectal prolapse is a debilitating condition with a complex etiology. Symptoms are most commonly prolapse of the rectum and pain with bowel movements or straining, with worsening fecal incontinence over time due to progressive stretching of the anal sphincters. Physical findings are fairly consistent from patient to patient—most notably diastasis of the levator ani muscles, deep pouch of Douglas, redundant sigmoid colon, a mobile mesorectum, and occasionally a solitary rectal ulcer. Evaluation includes a physical exam or imaging demonstrating the prolapse, and evaluating for other causes of pelvic floor dysfunction. Multiple surgical repairs are available, but treatment must be individualized based on patient symptoms and the presence or absence of constipation or other pelvic floor disorders. Mesh repairs have shown promising results, but carry the added risks of mesh erosion, infection, and mesh migration. The optimal repair has not been clearly demonstrated at this time.

The Role of Educational Research in the Global Setting

Given that most global surgery efforts have focused on service rather than education, there is very little written about educational research in the global surgery setting. As the focus of global surgery rotations shift from a purely volunteerism-driven effort to an educational experience for surgical trainees as well as providers in host institutions, there is a need to evaluate different ways education initiatives can be tailored and adapted to meet the needs of both sides. Academic institutions can partner with institutions in resource-limited countries to facilitate bridging the gap in surgical workforce, as well as help with training needs of these countries. It is in this educational environment that educational research can flourish.

Qualitative and quantitative comparison of colonic microendoscopy image features to histopathology

Colorectal cancer is the second leading cause of cancer deaths in the United States, affecting more than 130,000 Americans every year1. Determining tumor margins prior to surgical resection is essential to providing optimal treatment and reducing recurrence rates. Colorectal cancer recurrence can occur in up to 20% of cases, commonly within three years after curative treatment. Typically, when colorectal cancers are resected, a margin of normal tissue on both sides of the tumor is required. The minimum margin required for colon cancer is 5 cm and for the lower rectum 2 cm. However, usually more normal tissue is taken on both sides of the tumor because the blood supply to the entire segment is removed with the surgery and therefore the entire segment must be removed. Anastomotic recurrences may result from inadequate margins. Pathologists look at the margins to ensure that there is no residual tumor and this is usually documented in the pathology report. We have developed a portable, point-of-care fiber bundle microendoscopy imaging system for detection of abnormalities in colonic epithelial microstructure. The system comprises a laptop, a modified fiber bundle image guide with a 1mm active area diameter and custom LabVIEW interface, and is approved for imaging surgically resected colon tissue at the University of Arkansas for Medical Sciences. The microendoscopy probe provides high-resolution images of superficial epithelial histology in real-time to assist surgical guidance and to localize occult regions of dysplasia which may not be visible. Microendoscopy images of freshly resected human colonic epithelium were acquired using the microendoscopy device and subsequently mosaicked using custom post-processing software. Architectural changes in the glands were mapped to histopathology H&E slides taken from the precise location of the microendoscopy images. Qualitatively, glandular distortion and placement of image guide was used to map normal and dysplastic areas of the colonic tumor and surrounding region from microendoscopy images to H&E slides. Quantitative metrics for correlating images were also explored and were obtained by analyzing glandular diameter and spatial distribution as well as image texture.