MRI-Based Apparent Diffusion Coefficient for Predicting Pathologic Response of Rectal Cancer After Neoadjuvant Therapy: Systematic Review and Meta-Analysis.

OBJECTIVE: The purpose of this study was to assess the use of apparent diffusion coefficient (ADC) during DWI for predicting complete pathologic response of rectal cancer after neoadjuvant therapy. MATERIALS AND METHODS: A systematic review of available literature was conducted to retrieve studies focused on the identification of complete pathologic response of locally advanced rectal cancer after neoadjuvant chemoradiation, through the assessment of ADC evaluated before, after, or both before and after treatment, as well as in terms of the difference between pretreatment and posttreatment ADC. Pooled mean pretreatment ADC, posttreatment ADC, and Δ-ADC (calculated as posttreatment ADC minus pretreatment ADC divided by pretreatment ADC and multiplied by 100) in complete responders versus incomplete responders were calculated. For each parameter, we also pooled sensitivity and specificity and calculated the area under the summary ROC curve. RESULTS: We found 10 prospective and eight retrospective studies. Overall, pathologic complete response was observed in 22.2% of patients. Pooled mean pretreatment ADC in complete responders was 0.84 × 10-3 mm2/s versus 0.89 × 10-3 mm2/s in incomplete responders (p = 0.33). Posttreatment ADC values were 1.51 × 10-3 mm2/s and 1.29 × 10-3 mm2/s, in complete and incomplete responders, respectively (p = 0.00001). The Δ-ADC percentages were also significantly higher in complete responders than in incomplete responders (59.7% vs 29.7%, respectively, p = 0.016). Pooled sensitivity, specificity, and AUC were 0.743, 0.755, and 0.841 for pretreatment ADC; 0.800, 0.737, and 0.782 for posttreatment ADC; and 0.832, 0.806, and 0.895 for Δ-ADC. CONCLUSION: Use of ADC during DWI is a promising technique for assessment of results of neoadjuvant treatment of rectal cancer.

Safety of Propofol Used as a Rescue Agent During Colonoscopy.

GOAL: The goal of this study was to evaluate the safety of propofol when used by gastroenterologists in patients who have an inadequate response to standard sedation (narcotics and benzodiazepines). BACKGROUND: Many patients fail to achieve adequate sedation from narcotics and benzodiazepines during colonoscopy. The administration of propofol for colonoscopy is increasing, although its use by gastroenterologists is controversial. STUDY: We performed a retrospective review of our hospital's colonoscopy records from January 2006 to December 2009 to identify 403 subjects undergoing screening colonoscopies who required propofol (20 to 30 mg every 3 min as needed) because of inadequate response to standard sedation. We also randomly selected 403 controls undergoing screening colonoscopies from the same time period that only required standard sedation. The incidence of adverse effects was then compared. RESULTS: There were no major adverse events in either group. The rates of minor adverse events in the propofol and control group were 0.02 and 0.01, respectively (P=0.56). Adverse effects in the propofol group included: transient hypotension (n=1), nausea/vomiting (n=3), agitation (n=2), and rash (n=1). Adverse effects seen with standard sedation included: transient hypotension (n=2), nausea/vomiting (n=1), and oversedation (n=2). Patients who received propofol were more likely to be younger, had a history of illicit drug use, and a longer procedure time (P<0.05). CONCLUSIONS: Adjunctive propofol administered by gastroenterologist for conscious sedation was not associated with increased incidence of adverse events. It may be of value in patients who do not respond to conventional sedation.

Neostigmine Administered With MoviPrep Improves Bowel Preparation for Elective Colonoscopy in Patients With Spinal Cord Injury: A Randomized Study.

BACKGROUND: Poor preparation for elective colonoscopy is exceedingly common in persons with spinal cord injury (SCI). This unsatisfactory outcome is likely due to long-standing difficulty with evacuation and decreased colonic motility, which may result in inadequate responses to conventional bowel preparation regimens. We determined whether the addition of neostigmine to MoviPrep before elective colonoscopy produced a higher percentage of acceptable bowel preparations in patients with SCI. METHODS: Twenty-seven SCI subjects were prospectively randomized to 1 of 2 arms: low-volume polyethylene glycol-electrolyte lavage with ascorbic acid (MoviPrep) or MoviPrep plus neostigmine methylsulfate and glycopyrrolate (MoviPrep+NG); 28 able-bodied subjects received MoviPrep alone. The quality of the cleansing preparation for colonoscopy was determined by gastroenterologists "calibrated" to use the Ottawa Scoring System, with an acceptable Ottawa Score (OS) considered to be ≤3. RESULTS: The administration of MoviPrep alone resulted in suboptimal bowel cleansing in the SCI group compared with the able-bodied group (50% vs. 89% of subjects had an acceptable OS; χ=7.94, P=0.05). However, when NG was added to MoviPrep in the SCI group, it markedly improved the quality of the bowel preparation, with 85% of patients then having an acceptable OS. The use of NG resulted in minimal bloating and distention before bowel evacuation (P=0.0005), and eye and muscle twitching; these were resolved within 1 hour after NG administration. No significant differences were noted among the preparation groups for adenoma detection rate (P=0.41). CONCLUSIONS: The combination of MoviPrep+NG was safe, well tolerated, and an effective approach to prepare the bowel for elective colonoscopy in patients with SCI. The side effects of this preparation were significant compared with the other treatment groups but were considered mild and anticipated.

Complete pathologic response after combined modality treatment for rectal cancer and long-term survival: a meta-analysis.

BACKGROUND: Complete pathologic response (CPR) after neoadjuvant chemoradiotherapy (combined modality treatment, CMT) for rectal cancer seems associated with improved survival compared to partial or no response (NPR). However, previous reports have been limited by small sample size and single-institution design. METHODS: A systematic literature review was conducted to detect studies comparing long-term results of patients with CPR and NPR after CMT for rectal cancer. Variables were pooled only if evaluated by 3 or more studies. Study end points included rates of CPR, local recurrence (LR), distant recurrence (DR), 5-year overall survival (OS), and disease-free survival (DFS). RESULTS: Twelve studies (1,913 patients) with rectal cancer treated with CMT were included. CPR was observed in 300 patients (15.6%). CPR and NPR patient groups were similar with respect to age, sex, tumor size, distance of tumor from the anus, and stage of disease before treatment. Median follow-up ranged from 23 to 46 months. CPR patients had lower rates of LR [0.7% vs. 2.6%; odds ratio (OR) 0.45, 95% confidence interval (CI) 0.22-0.90, P = 0.03], DR (5.3% vs. 24.1%; OR 0.15, 95% CI 0.07-0.31, P = 0.0001), and simultaneous LR + DR (0.7% vs. 4.8%; OR 0.32, 95% CI 0.13-0.79, P = 0.01). OS was 92.9% for CPR versus 73.4% for NPR (OR 3.6, 95% CI 1.84-7.22, P = 0.002), and DFS was 86.9% versus 63.9% (OR 3.53, 95% CI 1.62-7.72, P = 0.002). CONCLUSIONS: CPR after CMT for rectal cancer is associated with improved local and distal control as well as better OS and DFS.

Meta-analysis of trials comparing minimally-invasive and open liver resections for hepatocellular carcinoma.

BACKGROUND: Recent literature suggests that minimally-invasive hepatectomy (MIH) for hepatocellular carcinoma (HCC) is associated with better perioperative results and similar oncologic outcomes compared to open hepatectomy (OH). However, previous reports have been limited by small sample size and single-institution design. METHODS: To overcome these limitations, we performed a meta-analysis of studies comparing MIH and OH in patients with HCC using a random-effects model. RESULTS: Nine eligible studies were identified that included 227 patients undergoing MIH and 363 undergoing OH. Patients were similar respect to age, gender, rates of cirrhosis, hepatitis C infection, tumour size, and American Society of Anesthesiology classification. The MIH group had lower rates of hepatitis B infection. There were no differences in type of resection (anatomic or non-anatomic), use of Pringle's maneuver, and operative time. Patients undergoing MIH had less blood loss [difference -217 mL; 95% confidence interval (CI), -314 to -121], lower rates of transfusion [odds ratio (OR), 0.38; 95% CI, 0.24 to 0.59], shorter postoperative stay (difference -5 days; 95% CI, -7.84 to -2.25), lower rates of positive margins (OR, 0.30; 95% CI, 0.12 to 0.69) and perioperative complications (OR, 0.45; 95% CI, 0.31 to 0.66). Survival outcomes were similar in the two groups. CONCLUSIONS: Although patient selection might have influenced some of the observed outcomes, MIH was associated with decreased blood loss, transfusions, rates of positive resection margins, overall and specific morbidity, and hospital stay. Survival outcomes did not differ between MIH and OH, although further studies are needed to evaluate the impact of MIH on long-term results.

A meta-analysis of prospective randomized trials comparing minimally invasive and open distal gastrectomy for cancer.

Current literature suggests that minimally invasive distal gastrectomy (MIDG) may enhance post-operative recovery and decrease morbidity compared to open surgery (ODG) in patients with gastric cancer. A meta-analysis of six Prospective Randomized Trials comparing MIDG (343 patients) and ODG (323 patients) for gastric cancer was conducted. MIDG was associated with increased operative time, reduced blood loss and overall morbidity. There was not sufficient data to draw solid conclusions about the oncologic quality of MIDG.

Metaanalysis of trials comparing minimally invasive and open distal pancreatectomies.

BACKGROUND: The current literature suggests that minimally invasive distal pancreatectomy (MIDP) is associated with faster recovery and less morbidity than open surgery. However, most studies have been limited by a small sample size and a single-institution design. To overcome this problem, the first metaanalysis of studies comparing MIDP and open distal pancreatectomy (ODP) has been performed. METHODS: A systematic literature review was conducted to identify studies comparing MIDP and ODP. Perioperative outcomes (e.g., morbidity and mortality, pancreatic fistula rates, blood loss) constituted the study end points. Metaanalyses were performed using a random-effects model. RESULTS: For the metaanalysis, 10 studies including 349 patients undergoing MIDP and 380 patients undergoing ODP were considered suitable. The patients in the two groups were similar with respect to age, body mass index (BMI), American Society of Anesthesiology (ASA) classification, and indication for surgery. The rate of conversion from full laparoscopy to hand-assisted procedure was 37%, and that from minimally invasive to open procedure was 11%. Patients undergoing MIDP had less blood loss, a shorter time to oral intake, and a shorter postoperative hospital stay. The mortality and reoperative rates did not differ between MIDP and ODP. The MIDP approach had fewer overall complications [odds ratio (OR), 0.49; 95% confidence interval (CI), 0.27-0.89], major complications (OR, 0.57; 95% CI, 0.34-0.96), surgical-site infections (OR, 0.32; 95% CI, 0.19-0.53), and pancreatic fistulas (OR, 0.68; 95% CI, 0.47-0.98). CONCLUSIONS: The MIDP procedure is feasible, safe, and associated with less blood loss and overall complications, shorter time to oral intake, and shorter postoperative hospital stay. Furthermore, the minimally invasive approach reduces the rate of pancreatic leaks and surgical-site infections after ODP.

Effect of verification bias on the sensitivity of fecal occult blood testing: a meta-analysis.

OBJECTIVES: There is controversy regarding the sensitivity of fecal occult blood tests (FOBT) for detecting colorectal cancer. Many of the published studies failed to correct for verification bias which may have increased the sensitivity. METHODS: A meta-analysis of published studies evaluating the sensitivity and specificity of chemical-based FOBT for colorectal cancer was performed. Studies were included if both cancer and control subjects underwent confirmatory testing. We also included studies that attempted to correct for verification bias by either performing colonoscopy on all subjects regardless of the FOBT result or by using longitudinal follow-up. We then compared the sensitivity, specificity, and other diagnostic characteristics of the studies that attempted to correct for verification (n=10) vs. those that did not correct for this bias (n=19). RESULTS: The pooled sensitivity of guaiac-based FOBT for colorectal cancer of studies without verification bias was significantly lower than those studies with this bias [0.36 (95% CI 0.25-0.47) vs. 0.70 (95% CI 0.60-0.80), p=0.001]. The pooled specificity of the studies without verification bias was higher [0.96 (95% CI 0.94-0.97) vs. 0.88 (95% CI 0.84-0.91), p<0.005]. There was no significant difference in the area under the summary receiver operating characteristic curves. More sensitive chemical-based FOBT methods (e.g., Hemoccult® SENSA®) had a higher sensitivity but a lower specificity than standard guaiac methods. CONCLUSIONS: The sensitivity of guaiac-based FOBT for colorectal cancer has been overestimated as a result of verification bias. This test may not be sensitive enough to serve as an effective screening option for colorectal cancer.

Anorectal stimulation causes increased colonic motor activity in subjects with spinal cord injury.

BACKGROUND: Difficulty with evacuation (DWE) is a major problem after spinal cord injury (SCI). Stimulation of the anal canal and lower rectum, accomplished using a gloved finger (so-called digital rectal stimulation or DRS) is often used as an adjunct to laxatives and enemas to facilitate bowel evacuation. However, the basis for the efficacy of DRS is not known. This study assessed the effect of DRS on colonic motility. METHODS: Six subjects with SCI were studied several hours after a bowel care session. Colonic motility was assessed using a manometric catheter (affixed endoscopically to the splenic flexure) at baseline, during DRS, and after DRS. In addition, evacuation of barium oatmeal paste (with the consistency of stool and introduced into the rectum and descending colon) was assessed simultaneously using fluoroscopic techniques. RESULTS: The mean number (+/- SEM) of peristaltic waves per minute increased from 0 at baseline to 1.9 (+/- 0.5/min) during DRS and 1.5 (+/- 0.3/min) during the period immediately after cessation of DRS (P < 0.05). The mean amplitude (+/- SEM) of the peristaltic contractions was 43.4 (+/- 2.2) mmHg. The frequency of contractions, as well as amplitude of contractions, during or immediately after DRS was not significantly different. These manometric changes in response to DRS were accompanied by expulsion of barium oatmeal paste in every subject by the fifth DRS. CONCLUSIONS: DRS causes left-sided colonic activity in subjects with SCI. At least in part, an anorectal colonic reflex that results in enhanced contractions of the descending colon and rectum may contribute to bowel evacuation in individuals with SCI.

Use of the surgical Apgar score to enhance Veterans Affairs Surgical Quality Improvement Program surgical risk assessment in veterans undergoing major intra-abdominal surgery.

BACKGROUND: We investigated whether the surgical Apgar score (SAS) may enhance the Veterans Affairs Surgical Quality Improvement Program (VASQIP) risk assessment for prediction of early postoperative outcomes. METHODS: We retrospectively evaluated demographics, medical history, procedure, SAS, VASQIP assessment, and postoperative data for patients undergoing major/extensive intra-abdominal surgery at the Manhattan Veterans Affairs between October 2006 and September 2011. End points were overall morbidity and 30-, 60- , and 90-day mortality. Pearson's chi-square, ANOVA, and multivariate regression modeling were employed. RESULTS: Six hundred twenty-nine patients were included. Apgar groups did not differ in age, sex, and race. Low SASs were associated with worse functional status, increased postoperative morbidity, and 30-, 60- , and 90-day mortality rates. SAS did not significantly enhance VASQIP prediction of postoperative outcomes, although a trend was detected. Multivariate analysis confirmed SAS as an independent predictor of morbidity and mortality. CONCLUSIONS: SAS effectively identifies veterans at high risk for poor postoperative outcome. Additional studies are necessary to evaluate the role of SAS in enhancing VASQIP risk prediction.

Comparison between pulsed irrigation enhanced evacuation and polyethylene glycol-electrolyte lavage solution for bowel preparation prior to elective colonoscopy in veterans with spinal cord injury.

BACKGROUND: Poor preparation for elective colonoscopy is common in persons with spinal cord injury (SCI). This unsatisfactory outcome is likely due to long-standing difficulty with evacuation and decreased colonic motility. Our objective was to determine the most effective preparation for elective colonoscopy applying a novel and traditional approach to bowel cleansing. METHODS: Twenty-four subjects with SCI were consented and scheduled to receive one of the two possible arms: pulsed irrigation enhanced evacuation (PIEE) or polyethylene glycol-electrolyte lavage solution (PEG; CoLyte(®)). The quality of the preparation was scored during the colonoscopy by applying the Ottawa scoring system. RESULTS: Patients with SCI who received PIEE tended to have lower Ottawa scores and a higher percentage of acceptable preparations than did those who received PEG; however, the results were not statistically different. CONCLUSION: In this preliminary study in subjects with SCI, neither PIEE nor PEG produced acceptable bowel preparation for elective colonoscopy. Future studies should confirm our findings and consider studying alternative, more efficacious approaches to bowel cleansing prior to colonoscopic procedures in patients with SCI, which should provide better outcomes. Registration number for clinicaltrials.gov: NCT00745095.

Validation of the Surgical Apgar Score in a veteran population undergoing general surgery.

BACKGROUND: The Surgical Apgar Score (SAS, a 10-point score calculated using limited intraoperative data) can correlate with postoperative morbidity and mortality after general surgery. We evaluated reliability of SAS in a veteran population. STUDY DESIGN: We prospectively collected demographics, medical history, type of surgery, and postoperative outcomes for any veteran undergoing general surgery at our institution (2006-2011). We categorized patients in 4 SAS groups and compared differences in morbidity and mortality. RESULTS: Our study population included 2,125 patients (SAS ≤4: n = 29; SAS 5-6: n = 227; SAS 7-8: n = 797; SAS 9-10: n = 1,072). Low-SAS patients were likely to have significant preoperative comorbidities and to undergo major surgery, and had increased postoperative morbidity and 30-day mortality. CONCLUSIONS: The SAS is easily calculated from 3 routinely available intraoperative measurements, correlates with fixed preoperative risk (acute conditions, pre-existing comorbidities, operative complexity), and effectively identifies veterans at high risk for postoperative complications.

Meta-analysis of trials comparing laparoscopic transperitoneal and retroperitoneal adrenalectomy.

BACKGROUND: Laparoscopic adrenalectomies are being performed increasingly, either with transperitoneal or retroperitoneal approaches. Studies comparing the 2 approaches have not shown the superiority of either technique, but these studies are limited by small sample sizes and single-institution designs. To overcome these limitations, we performed a meta-analysis of studies comparing lateral transperitoneal adrenalectomy and retroperitoneal adrenalectomy. METHODS: A systematic review of studies comparing lateral transperitoneal adrenalectomy and retroperitoneal adrenalectomy was conducted. Study endpoints included perioperative outcomes and measures of postoperative recovery. Meta-analysis was performed using a random effects model, pooling variables evaluated by more than 3 studies. RESULTS: Twenty-one studies comparing a total of 1,205 lateral transperitoneal adrenalectomies and 688 retroperitoneal adrenalectomies were suitable for meta-analysis. Patients in the 2 groups were similar in term of age, sex, body mass index, lesion size and location, and rates of malignancy. There were no statistically significant differences between lateral transperitoneal adrenalectomy and retroperitoneal adrenalectomy in terms of operative time, blood loss, hospital stay, time to oral intake, overall and major morbidity, and mortality. CONCLUSION: Both lateral transperitoneal adrenalectomy and retroperitoneal adrenalectomy are associated with very low rates of perioperative complications. According to our meta-analysis, clinical outcomes after either technique are similar. For most adrenal lesions requiring operation, minimally invasive adrenalectomy can be performed safely and effectively with either transperitoneal or the retroperitoneal approach. Additional studies may be needed to analyze if any difference in long-term results exist.

Safety of hepatic resections in obese veterans.

OBJECTIVE: To determine the effects of body mass index (BMI; calculated as weight in kilograms divided by height in meters squared) on outcomes after liver resection performed at Veterans Affairs medical centers. DESIGN, SETTING, AND PATIENTS: We queried the Veterans Affairs Surgical Quality Improvement Program database for liver resections (2005-2008) and grouped the patients into 5 BMI categories: normal weight (BMI 18.5-24.9), overweight (BMI 25.0-29.9), obese class 1 (BMI 30.0-34.9), obese class 2 (BMI 35.0-39.9), and obese class 3 (BMI ≥ 40.0). Differences in risk factors and perioperative complications across groups were analyzed in univariate and multivariate analyses. RESULTS: Of 403 patients who underwent hepatectomy, 106 (26%) were normal weight, 161 (40%) were overweight, 94 (23%) were obese class 1, 31 (8%) were obese class 2, and 11 (3%) were obese class 3. Among these groups, higher BMI was associated with increased rates of hypertension (52%, 61%, 77%, 77%, and 73%, respectively; P = .002) and diabetes (18%, 27%, 36%, 39%, and 45%, respectively; P = .04) and lower incidence of smokers (53%, 35%, 30%, 16%, and 9%, respectively; P < .001). The BMI groups were similar in demographic characteristics and metrics correlating with preexisting liver disease. There were no differences across BMI groups in overall and specific morbidity or in length of stay. Compared with the other groups, obese class 3 patients received more blood transfusions (mean [SD], 4.3 [2.7] in obese class 3 patients vs 1.1 [0.2] in normal-weight patients; P = .02) and had a higher 30-day mortality (27% in obese class 3 patients vs 6% in normal-weight patients; P = .05). Multivariate analyses confirmed obese class 3 as an independent predictor of postoperative mortality. CONCLUSIONS: Obesity did not increase postoperative complications after liver resection in veterans. After adjusting for other clinical factors, extreme obesity (BMI ≥ 40.0) was an independent risk factor for increased mortality.

Absence of high amplitude propagating contractions in subjects with chronic spinal cord injury.

AIM: To investigate the presence or absence of high amplitude propagating contractions (HAPC), as well as the other measures of colonic motility, in persons with spinal cord injury (SCI). METHODS: Prolonged colonic ambulatory manometric studies were performed on 14 male volunteers: 8 with SCI (mean age, 59 ± 13 years; mean duration of injury, 13 ± 4 years) and 6 healthy able-bodied controls (mean age, 57 ± 10 years). A solid-state manometry catheter was endoscopically clipped to the splenic flexure. Recording was performed for > 24 h after manometric catheter placement. RESULTS: HAPC were absent in individuals with SCI during pre-sleep, sleep, and post-sleep phases. HAPC were significantly increased after awakening in non-SCI controls (0.8 ± 0.2 HAPC/h vs 10.5 ± 2.0 HAPC/h, P < 0.005). The motility index was lower in those with SCI than in controls pre- and post-sleep (SCI vs non-SCI: Pre-sleep, 2.4 ± 0.4 vs 8.8 ± 1.9, P < 0.01; Post-sleep, 4.3 ± 0.8 vs 16.5 ± 4.5, P < 0.05). However, a sleep-induced depression of colonic motility was observed in both the SCI and non-SCI groups (Pre-sleep vs Sleep, non-SCI: 8.8 ± 1.9 vs 2.1 ± 0.9, P < 0.002; SCI: 2.4 ± 0.4 vs 0.2 ± 0.03, P < 0.001), with the motility index of those with SCI during sleep not significantly different than that of the controls. CONCLUSION: HAPC were not observed in individuals with SCI pre- or post-sleep. A sleep-induced depression in general colonic motility was evident in SCI and control subjects.

Intramuscular neostigmine and glycopyrrolate safely accelerated bowel evacuation in patients with spinal cord injury and defecatory disorders.

Difficulty with evacuation after spinal cord injury (SCI) may be due to a lack of parasympathetic stimulation of the colon. Prior studies in persons with spinal cord injury have suggested that intravenous administration of neostigmine stimulates colonic motility while glycopyrrolate attenuates some of the cholinergic side effects of neostigmine. We thus performed a double-blind, cross-over study to evaluate the effect of neostigmine/glycopyrrolate injections in patients with SCI and defecatory difficulties. Seven subjects received active treatment (neostigmine 2 mg and glycopyrrolate 0.4 mg intramuscularly) during three consecutive bowel evacuation sessions and were crossed-over to placebo injections for three consecutive sessions. Compared with placebo, neostigmine/glycopyrrolate reduced the total bowel evacuation time from 98.1 +/- 7.2 to 74.8 min +/- 5.8 (p < 0.05). The lowest heart rate or blood pressure was not significantly different between the treatment and placebo groups. In conclusion, neostigmine/glycopyrrolate may improve bowel evacuation in patients with SCI-related defecatory disorders.

Meta-analysis comparing CT colonography, air contrast barium enema, and colonoscopy.

INTRODUCTION: Published studies have reported a wide range of sensitivities and specificities for computed tomographic (CT) colonography for polyp detection, generating controversy regarding its diagnostic accuracy. METHODS: A meta-analysis of published studies comparing the accuracies of CT colonography and colonoscopy for polyp detection was performed. The pooled per-patient sensitivities and specificities were calculated at various thresholds for polyp size. Summary receiver operating characteristic (sROC) curves were also constructed. RESULTS: Thirty studies were included in the meta-analysis of CT colonography. The pooled per-patient sensitivity of CT colonography was higher for polyps greater than 10 mm (0.82, 95% confidence interval [CI], 0.76-0.88) compared with polyps 6 to 10 mm (0.63, 95% CI, 0.52-0.75) and polyps 0 to 5 mm (0.56, 95% CI, 0.42-0.70). Similarly, the exact area under the sROC curve (area +/- standard error) was higher using a threshold greater than 10 mm (0.898 +/- 0.063) compared with thresholds of greater than 5 mm and any size (0.884 +/- 0.033 and 0.822 +/- 0.059, respectively). There were no significant differences in the diagnostic characteristics of 2-dimensional versus 3-dimensional CT colonography. At a threshold greater than 5 mm, the exact area under the sROC curve was significantly higher for endoscopic colonoscopy compared with CT colonography (0.998 +/- 0.006 vs 0.884 +/- 0.033, P < .005). CONCLUSIONS: CT colonography has a reasonable sensitivity and specificity for detecting large polyps but was less accurate than endoscopic colonoscopy for smaller polyps. Thus, CT colonography may not be a reasonable alternative in situations in which a small polyp may be clinically relevant.

Infusion of neostigmine-glycopyrrolate for bowel evacuation in persons with spinal cord injury.

Defecatory complications are common after spinal cord injury (SCI) and have been attributed, in part, to an imbalance of the autonomic nervous system between parasympathetic and sympathetic effects on the colon. Because parasympathetic (i.e., cholinergic) input to the bowel may be downregulated after SCI, it was hypothesized that neostigmine, a medication that increases cholinergic tone by blocking the metabolism of acetylcholine, might promote bowel evacuation in these persons. Since neostigmine is known to cause bradycardia and bronchoconstriction, we also assessed whether these side-effects could be prevented by coadministration of neostigmine with glycopyrrolate, an anticholinergic agent that has limited activity on the muscarinic receptors of the colon. The hypothesis was tested in 13 persons with SCI in whom videofluoroscopy was carried out after instillation of a barium oatmeal paste into the rectum and descending colon. On separate days, subjects received, in a randomized, blinded design, one of three intravenous infusates (normal saline, 2 mg neostigmine, or 2 mg neostigmine + 0.4 mg glycopyrrolate). The effect of these infusates on bowel evacuation of the barium paste, heart rate, and airway resistance was determined. Both neostigmine and neostigmine + glycopyrrolate resulted in prompt bowel evacuation. The nadir heart rate was lower after neostigmine alone than with the combination. Neostigmine administration increased both total and central airway resistance, an effect that was not observed with the coadministration of glycopyrrolate. Other side-effects of neostigmine and the combination of drugs included muscle fasciculations and dry mouth, both of which were mild and short-lived. Abdominal cramping was noted in subjects with spinal cord lesions below thoracic level 10. These results indicated that neostigmine/glycopyrrolate administration is safe and well tolerated in persons with chronic SCI.