Richard L. Nelson

Dietary iron and colorectal cancer risk.

Intestinal exposure to ingested iron may be a principal determinant of human colorectal cancer risk. Evidence exists associating iron with both the initiating and promoting phases of carcinogenesis as well as somatic defenses against early cancers through hypoferremia (progression or proliferation). Iron intake and the ingestion of associated foods that greatly affect iron bioavailability and absorption (phytate, tannin, ascorbate, and alcohol) vary widely between high-risk and low-risk countries as well as within the United States. These variances in intake may explain not only the gradients in risk between populations, but the crossover in risk between sexes related to age within the United States. Human and rodent studies support the above hypothesis and are reviewed herein, however they are few in number and in many cases lack key data.

Repair of fistulas-in-ano using fibrin adhesive

PURPOSE: Fibrin adhesive has been successfully used to treat fistulas-in-ano, but long-term data have been lacking. We report the results of our 18-month study examining the repair of fistulas-in-ano using autologous and commercial fibrin adhesive. METHODS: A 79-patient, prospective, nonrandomized clinical trial was performed in which fibrin adhesive was used to repair fistulas-in-ano. Twenty-six patients were treated with autologous fibrin tissue adhesive made from their own blood, and 53 patients were treated with commercial fibrin sealant. In the operating room the patient underwent an examination under anesthesia, with an attempt to identify the primary and secondary fistula tract openings. The fistula tract was then curetted. Fibrin adhesive was injected into the secondary fistula tract opening until adhesive was seen coming from the primary opening. A petroleum jelly gauze was then applied over both the primary and secondary openings, and the patient was sent home. Follow-up visits occurred one week, one month, three months, and one year later. RESULTS: Fourteen of 26 (54 percent) patients treated with autologous fibrin tissue adhesive made from their own blood had complete closure of their fistulas after a one-year follow-up, whereas 34 of 53 (64 percent) patients treated with commercial fibrin sealant had closure of their fistulas. Most treatment failures occurred within the first 3 months, but late failures were seen as far as 11 months postoperative. CONCLUSIONS: Fibrin tissue adhesive offers a unique mode of managing fistulas-in-ano, which is surgically less invasive, but recurrences up to one year later are being seen. Longer follow-up and further research is recommended for improvement.

Repair of fistulas-in-ano using autologous fibrin tissue adhesive

PURPOSE: Our goal was to determine if autologous fibrin tissue adhesive derived from the precipitation of fibrinogen using a combination of ethanol and freezing, could be used to completely close both simple and complex fistulas-inano. METHODS: A 26-patient pilot study was performed in which 100 ml of a patients blood was drawn 90 minutes before surgery. Autologous fibrin tissue adhesive was prepared. In the operating room the patient underwent an examination under anesthesia, and the primary and secondary fistula tract openings were attempted to be identified. The fistula tract was curetted, and autologous fibrin tissue adhesive was injected into the secondary fistula tract opening until fibrin glue was seen coming from the primary opening. A petroleum jelly gauze was then applied over the secondary opening, and the patient was sent home. Follow-up visits were scheduled for one week, one month, three months, and one year later. RESULTS: Twenty-six patients received autologous fibrin tissue adhesive fistula injections, with a mean follow-up of 3.5 months. Initial results were encouraging. Twenty-one of 26 patients (81 percent) had successful initial closure of their fistulas. Two of five failures were injected a second time, and one closed, giving an overall successful closure rate of 85 percent (22/26 patients). Of five patients who failed, mean time to failure was 3.8 weeks. In addition, there was no evidence of infection or complications related to the procedure. CONCLUSION: Our initial results are optimistic and require further support through longer follow-up data. Fibrin glue treatment of anorectal fistulas offers a unique mode of management that is safe, simple, and easy for the surgeon to perform. By using autologous fibrin tissue adhesive the patient avoids the risk of anal incontinence and the discomfort of prolonged wound healing which may be associated with fistulotomy.

A systematic review of the efficacy of cesarean section in the preservation of anal continence

PurposeElective primary cesarean section is performed largely to avoid maternal pelvic trauma that may result in anal incontinence, although its efficacy in this regard has not been thoroughly assessed. We perform a systematic review of published reports that compare anal incontinence risk by mode of delivery.MethodsPubMed was searched from 1966 through August 2005. Authors were contacted for missing data or analyses. Both randomized and nonrandomized reports were included. Eligible studies included females having vaginal delivery or cesarean section, fecal and/or flatal incontinence was reported as an outcome, and risk was calculable from the reported data. Crude data were extracted from the reports, as well as reported odds ratios and confidence intervals. In the nonrandomized studies, adjusted odds ratios also were extracted and additional data obtained from authors to adjust risks for age and parity if not originally done. Sensitivity analyses were performed using quality indicators: age and parity adjustment, time to continence assessment, and mode of previous delivery.ResultsFifteen studies were found eligible, encompassing 3,010 cesarean sections and 11,440 vaginal deliveries. The summary relative risk for fecal incontinence was 0.91 (95 percent confidence interval, 0.74–1.14). For flatus the relative risk was 0.98 (range, 0.86–1.13). The number needed to treat by cesarean section was 167 to prevent a single case of fecal incontinence. Five studies were judged to be of high quality. In these studies, the summary relative risk was 0.94 (range, 0.72–1.22) and number needed to treat was 198.ConclusionsThe best evidence to assess the efficacy of cesarean section in the prevention of anal incontinence would be in randomized trials of average-risk pregnancies with few crossovers. In the absence of such trials and based on this review, cesarean section does not prevent anal incontinence. This implies that incontinence associated with delivery may be more likely incontinence caused by pregnancy.

Time trends in distal colorectal cancer subsite location related to age and how it affects choice of screening modality

A time trend analysis of colorectal cancer (CRC) incidence in the distal colorectum as a proportion of total CRC is presented for the period 1977–1994 as a function of age, to determine the age at which Americans might best be served by screening fiberoptic sigmoidoscopy.

Technical manual for manufacturing autologous fibrin tissue adhesive

PURPOSE: The aim of this article is to provide a concise and simple technical manual for manufacturing autologous fibrin tissue adhesive derived from the precipitation of fibrinogen using a combination of ethanol and freezing for surgery. METHODS: All materials and equipment needed to manufacture ethanol-based autologous fibrin tissue adhesive are listed. In addition, step-by-step instructions are provided to allow for easy and rapid fibrin adhesive production. RESULTS: Ethanol-based autologous fibrin tissue adhesive can be manufactured in under 60 minutes. Furthermore, at our institution the startup cost for manufacturing ethanol-based autologous fibrin tissue adhesive was under

A Systematic Review of Hepatic Artery Chemotherapy After Hepatic Resection of Colorectal Cancer Metastatic to the Liver

2,500.00. CONCLUSION: Ethanol-based autologous fibrin tissue adhesive is a safe, reliable, and easily manufactured autologous fibrin tissue adhesive that can be made by a trained technician in any blood bank, pharmacy, or surgical laboratory.

The association of carcinoid tumors of the rectum with myelofibrosis: Report of two cases

PURPOSEColorectal cancer metastatic to the liver, when technically feasible, is resected with a moderate chance of cure. The most common site of failure after resection is in the remaining liver. To enhance survival, chemotherapy has been delivered directly to the liver postresection via the hepatic artery. This study was designed to assess the effect of posthepatic resection, hepatic artery chemotherapy on overall survival.METHODSTrials were sought in Medline, the Cochrane Controlled Trial Register, The Cochrane Hepatobiliary Group Trials Register, and through contact of trial authors and reference lists using key words: colorectal, cancer, hepatic metastases, hepatic artery, chemotherapy, and randomized. Trials were chosen in which patients having resection of colorectal cancer metastatic to the liver were randomized to hepatic artery chemotherapy or any alternative treatment. Survival data were obtained principally from abstraction from survival curves in published studies using the method of Parmar to calculate a study-specific, log-hazard ratio and then combined-effect, log-hazard ratio, as well as a combined Kaplan-Meier survival probability curve.RESULTSOverall survival at five years in the hepatic artery group was 45 percent and 40 percent in the control group. Forty-three individuals developed recurrent liver metastases in the hepatic artery chemotherapy group, and 97 developed liver recurrence in the control group. However, no significant advantage was found in the meta-analysis for hepatic artery chemotherapy measuring overall survival and calculating survival based on “intention to treat” (log-hazard ratio = 0.0848, favoring the control group; 95 percent confidence interval = ±0.2037). Adverse events related to hepatic artery therapy were common, including five therapy-related deaths.CONCLUSIONSAlthough recurrence in the remaining liver happened less frequently in the hepatic artery chemotherapy group, overall survival was not improved. The log-hazard ratio even favored the control group, although not significantly. This added intervention for the treatment of metastatic colorectal cancer cannot be recommended at this time.

Primary repair of penetrating colonic injuries1

Two patients with myelofibrosis, a primary malignancy of the hematopoietic system, have developed carcinoid tumors of the rectum. This development is rare, as rectal carcinoids are more often associated with other carcinomas of the gastrointestinal tract. Rectal carcinoid tumors are, in general, less commonly associated with second malignancies than are carcinoid tumors of foregut and midgut origin

Fistula Surgery in the Era of Evidence-Based Medicine

PURPOSE: Primary repair of penetrating colon injuries is an appealing management option; however, uncertainty about its safety persists. This study was conducted to compare the morbidity and mortality of primary repair with fecal diversion in the management of penetrating colon injuries by use of a meta-analysis of randomized, prospective trials. METHODS: We searched for prospective, randomized trials in MEDLINE (1966 to November 2001), the Cochrane Library, and EMBase using the terms colon, penetrating, injury, colostomy, prospective, and randomized. Studies were included if they were randomized, controlled trials that compared the outcomes of primary repair with fecal diversion in the management of penetrating colon injuries. Five studies were included. Reviewers performed data extraction independently. Outcomes evaluated from each trial included mortality, total complications, infectious complications, intra-abdominal infections, wound complications, penetrating abdominal trauma index, and length of stay. Peto odds ratios for combined effect were calculated with a 95 percent confidence interval for each outcome. Heterogeneity was also assessed for each outcome. RESULTS: The penetrating abdominal trauma index of included subjects did not differ significantly between studies. Mortality was not significantly different between groups (odds ratio, 1.70; 95 percent confidence interval, 0.51–5.66). However, total complications (odds ratio, 0.28; 95 percent confidence interval, 0.18–0.42), total infectious complications (odds ratio, 0.41; 95 percent confidence interval, 0.27–0.63), abdominal infections including dehiscence (odds ratio, 0.59; 95 percent confidence interval, 0.38–0.94), abdominal infections excluding dehiscence (odds ratio, 0.52; 95 percent confidence interval, 0.31–0.86), wound complications including dehiscence (odds ratio, 0.55; 95 percent confidence interval, 0.34–0.89), and wound complications excluding dehiscence (odds ratio, 0.43; 95 percent confidence interval, 0.25–0.76) all significantly favored primary repair. CONCLUSION: Meta-analysis of currently published randomized, controlled trials favors primary repair over fecal diversion for penetrating colon injuries.