Jeffrey P. Cohen

Practice parameters for the management of rectal cancer (revised).

The American Society of Colon and Rectal Surgeons is dedicated to assuring high-quality patient care by advancing the science, prevention, and management of disorders and diseases of the colon, rectum, and anus. The Standards Committee is composed of Society members who are chosen because they have demonstrated expertise in the specialty of colon and rectal surgery. This Committee was created to lead international efforts in defining quality care for conditions related to the colon, rectum, and anus. This is accompanied by developing Clinical Practice Guidelines based on the best available evidence. These guidelines are inclusive, and not prescriptive. Their purpose is to provide information on which decisions can be made, rather than dictate a specific form of treatment. These guidelines are intended for the use of all practitioners, health care workers, and patients who desire information about the management of the conditions addressed by the topics covered in these guidelines. It should be recognized that these guidelines should not be deemed inclusive of all proper methods of care or exclusive of methods of care reasonably directed to obtaining the same results. The ultimate judgment regarding the propriety of any specific procedure must be made by the physician in light of all of the circumstances presented by the individual patient.

Public Infrastructure Investment, Interstate Spatial Spillovers, and Manufacturing Costs

Effects of public infrastructure investment on the costs and productivity of private enterprises have proven difficult to quantify empirically. One piece of this puzzle that has received little attention is spatial spillovers. We apply a cost-function model to 1982-1996 state-level U.S. manufacturing data, to untangle the private cost-saving effects of inter- and intrastate public infrastructure investment. We implement two spatial adaptations-including a spatial spillover index in the theoretical model, and allowing for spatial autocorrelation in the stochastic structure. Recognizing such spillovers both increases the estimated magnitude and significance of cost savings from intrastate public infrastructure, and augments these productive effects.

Cyclosporine for the treatment of fulminant ulcerative colitis in children: Immediate response, long-term results, and impact on surgery

PURPOSE: Emergency surgery for fulminant colitis is often complicated by high-dose steroid therapy, poor nutrition, and psychologic maladjustment. Cyclosporine is effective for fulminant ulcerative colitis in adults, resulting in avoidance of immediate surgery in 75 percent of patients and a 55 percent long-term remission rate. Over the last five years, we studied the effectiveness of cyclosporine in children with fulminant colitis. METHODS: Fourteen patients with ulcerative colitis (age, 7–20 years) received cyclosporine after satisfying the following criteria: 1) greater than five bloody diarrheal stools per day; 2) severe abdominal pain; 3) no improvement after ten days of bowel rest, 4) intravenous methylprednisolone (1–2 mg/kg/day); and 5) parenteral nutrition. Treatment was begun with oral cyclosporine (4.6–9.6 mg/kg/day), and the dose was adjusted to achieve whole blood trough levels measured with a monoclonal radioimmunoassay between 150 and 300 ng/ml. If improved, patients were discharged on oral cyclosporine, prednisone, and a regular diet. RESULTS: Eleven of 14 patients (78 percent) responded within two to nine days and were able to consume a normal diet, had three or less soft stools per day, and had no pain. One did not respond after ten days and underwent an ileal pouch-anal anastomosis procedure. Two patients elected surgery after 20 days of therapy and a partial response. Of 11 patients who left the hospital, 4 had recurrent symptoms after 2 to 11 months of taking therapeutic doses of cyclosporine and 3 flare ups while weaning from cyclosporine after 4 to 8 months. Three patients have been weaned from cyclosporine after 8 to 13 months and have remained in remission from six months to five years. One patient is about to complete a six-month course of cyclosporine. Overall ten (72 percent) have undergone surgery, including 7 of 11 who responded initially to cyclosporine and left the hospital. Weight (P<0.001), albumin (P<0.01), erythrocyte sedimentation rate (P>0.05), and prednisone dose (P<0.001) improved significantly in the seven patients on cyclosporine who responded initially, left the hospital, and subsequently underwent surgery. CONCLUSIONS: Cyclosporine is effective in achieving clinical remission in 80 percent of children with refractory fulminant colitis; however, within one year, most initial responders will require colectomy because of a flare up of the disease. In a majority of patients, the role of cyclosporine therapy is to rapidly ameliorate symptoms and prevent precipitous colectomy, improve nutrition and psychologic adaptation, and reduce the steroid dose leading to surgery in a well-prepared patient.

The changing paradigm for the treatment of colonic hemorrhage: Superselective angiographic embolization

AbstractPURPOSE: Colonic bleeding has historically been controlled by the use of localization procedures and surgery. Since our initial experience with superselective embolization of colonic bleeding, it has become our preferred method for the control of lower gastrointestinal hemorrhage. This follow-up study evaluates the Hartford Hospital experience using angiographic methods as the primary modality for the treatment of colonic bleeding. METHODS: From March 1993 to September 1999, 27 patients who had angiographically visualized colonic hemorrhage underwent arterial embolization procedures. Diagnostic arteriography was performed in all patients using digital subtraction imaging and selective contrast injections into the superior and inferior mesenteric arteries. Once the bleeding site was identified, superselective arteriogram and embolization was performed. Platinum-fibered coils, Hilal coils, or polyvinyl alcohol particle emboli were then fluoroscopically guided into the bleeding vessel. A repeat arteriogram was performed to confirm occlusion and the absence of any collateral channels. RESULTS: All 27 patients were initially controlled with arterial embolization; 6 patients rebled (22.2 percent), and 5 of these patients required surgery. Two patients demonstrated ischemia (7.4 percent), one of which required surgical intervention. The other patient was followed up by colonoscopy. There was no mortality in this study. CONCLUSION: Superselective embolization is effective in controlling colonic hemorrhage and is associated with a low rate of postembolization ischemia. Our experience with angiography reinforces the paradigm shift from its use as a diagnostic tool to the primary method for the control of colonic bleeding. Because patients have been followed up for as long as seven years, this approach remains effective for the long-term treatment of colonic bleeding.

THE IMPACTS OF TRANSPORTATION INFRASTRUCTURE ON PROPERTY VALUES: A HIGHER‐ORDER SPATIAL ECONOMETRICS APPROACH

We evaluate the impacts of enhanced transportation systems on property values for U.S. manufacturing firms, allowing for higher-order spatial error correlation. We use a state-level model of production cost and input demand that recognizes the productive contribution of public transportation infrastructure stocks. Our findings include significant impacts on property shadow values and input composition from both public highway and airport investment. We also find that these effects have a spatial dimension that depends on the proximity of the transport system; at least one and as many as three spatial error lags are significant in our estimating equations. Further, recognizing production growth from transportation system improvements augments the associated incentives for private capital investment.

Preoperative immunosuppression is not associated with increased postoperative complications following colectomy in children with colitis.

Objectives: The aim of the present study was to review postoperative complications of pediatric patients undergoing colectomy for ulcerative colitis (UC) or inflammatory bowel disease-unspecified (IBD-U) with a focus on preoperative immunosuppression including exposure to infliximab. Methods: We performed a retrospective chart review of all of the children with UC or IBD-U undergoing colectomy at our institution from 1996 to 2010. Data collected included indication for colectomy, immunosuppressive medications taken within 30 to 90 days of colectomy, surgical techniques and staging, and early and late postoperative complications. Results: A total of 51 patients underwent colectomy (45 UC, 6 IBD-U) (55% male, 63% pancolitis at diagnosis, mean age at diagnosis 10.8 ± 3.8 years, mean age at colectomy 13.1 ± 3.8 years). Indications for colectomy were fulminant colitis in 26% and medically refractory chronic disease in 74%. Patient exposure to immunosuppression in the 30 days before colectomy included corticosteroids (88%), thiopurines (51%), and calcineurin inhibitors (4%). Within 90 days before colectomy, 65% of patients were exposed to infliximab. Small bowel obstruction was the most common postoperative complication, occurring in 19% (treated surgically in 30%), followed by wound infection in 8% and intraabdominal abscess in 6%. One patient developed postoperative sepsis. There was no increased incidence of early or late infectious or noninfectious complications in those patients taking or not taking thiopurines or calcineurin inhibitors (within 30 days), or infliximab (within 90 days). Conclusions: Preoperative exposure to thiopurines or calcineurin inhibitors (within 30 days) or infliximab (within 90 days) was not associated with increased postoperative complications in our cohort undergoing colectomy for UC or IBD-U.

Preoperative Colonoscopy Decreases the Need for Laparoscopic Management of Colonic Polyps

PURPOSEPatients are commonly referred to surgeons for surgical resection of polyps that cannot be excised colonoscopically. Repeating the colonoscopy may be met with resistance by both the patient and the referring endoscopist. However, there are two distinct benefits. First, if the lesion was not marked, tattooing facilitates laparoscopic resection. Second, and more importantly, many of these polyps can be removed endoscopically by an experienced colorectal surgeon, avoiding unnecessary colon resection. Over a period of five years, we have reviewed preoperative colonoscopy in patients who were referred for surgical treatment of benign polyps.METHODSFrom January 1999 through September 2003 all patients referred for surgical resection of a benign polyp were consecutively entered into a database by a single group of colorectal surgeons. All patients underwent preoperative colonoscopy on the day before the planned colon resection. Patient charts were reviewed, and demographics were recorded. The referral and preoperative colonoscopy reports and all pathology results were reviewed to record the polyp size, location, histology, and subsequent treatment.RESULTSAltogether, 71 patients were included in this study. The average size of the polyps was 24 mm (range, 10–60 mm). The location of the polyp as determined by preoperative colonoscopy differed from the location noted on referral colonoscopy in nine patients (13 percent). Surgery was canceled in 23 patients (32 percent), primarily because of complete polypectomy at preoperative colonoscopy. Of the 48 who underwent surgery, 23 (47 percent) had a colonic tattoo placed, at the discretion of the surgeon. Lesions clearly located in the cecum were not tattooed routinely. Of the 48 patients who underwent surgery, 45 (94 percent) underwent laparoscopic colon resection.CONCLUSIONSWe concluded that patients referred for surgical resection of a polyp should undergo repeat colonoscopy preoperatively, given that in our study one-third of patients were spared unnecessary colectomy. In addition, repeat endoscopy by the operating surgeon offers an opportunity to confirm the location of the lesion and place a colonic tattoo to facilitate laparoscopic resection.

Agglomeration, Productivity and Regional Growth: Production Theory Approaches

Agglomeration Economies, or production cost savings due to geographic clustering of firms and industries, can enhance the growth and development of firms, industries, regions and cities. We provide an overview of the theory and empirical literature of agglomeration, and highlight several applications from the cost function perspective. These applications include cost savings from density in the U.S. food manufacturing industry (Cohen and Morrison Paul, 2005); transportation infrastructure and costs for the overall manufacturing sector in the U.S. (Cohen and Morrison Paul, 2007); and hospital locations and costs in the State of Washington (Cohen and Morrison Paul, forthcoming). In all of these applications, the authors find significant evidence of various forms of agglomeration economies.

Ports and Highways Infrastructure: An Analysis of Intra- and Interstate Spillovers

U.S. ports serve a vital role in the nations supply chain and international trade. While the areas surrounding these ports bear the external costs of port expansion (congestion, air and noise pollution), neighboring regions feel the benefits and additional costs from port activity. Given the current debate over external costs from port activity, it is important to quantify the costs and benefits of ports on industry in the home state and neighboring states. This study assesses the role that transportation infrastructure plays in production and employment in the manufacturing industry. Using state-level data from the 48 contiguous states, the authors model manufacturing production and cost, incorporating state and local investment in port and highway infrastructure as variables. The authors find lower manufacturing costs in states with increased ports infrastructure. However manufacturing firms experience higher costs if a neighboring state increases its ports infrastructure, perhaps because productive resources (firms and workers) are drawn to states that increase ports infrastructure.

Spatial and supply/demand agglomeration economies: State- and industry-linkages in the U.S. food system

Cost-impacts of spatial and industrial spillovers on economic performance are evaluated by incorporating activity level measures for nearby states and related industries into a cost function model. We focus on localization and urbanization economies for state level food processing industries, from activity levels of similar industries in neighboring states, agricultural input suppliers, and final product demand. We find significant cost-savings from proximity to other food manufacturing centers, and areas with high purchasing power. Cost savings from locating near an agricultural area are also evident, although it seems costly to be located within a rural agricultural state, implying thin market diseconomies. Marginal production costs instead appear higher in more urban, and lower in more rural, areas. These spillover patterns also have input composition implications; materials demand responses are the most closely tracked by the agglomeration cost effects, and capital and labor impacts vary.