Miss rate of colorectal neoplastic polyps and risk factors for missed polyps in consecutive colonoscopies

BACKGROUND/AIMS: Colonoscopic polypectomy is the best diagnostic and therapeutic tool to detect and prevent colorectal neoplasms. However, previous studies have reported that 17% to 28% of colorectal polyps are missed during colonoscopy. We investigated the miss rate of neoplastic polyps and the factors associated with missed polyps from quality-adjusted consecutive colonoscopies. METHODS: We reviewed the medical records of patients who were found to have colorectal polyps at a medical examination center of the Kangbuk Samsung Hospital between March 2012 and February 2013. Patients who were referred to a single tertiary academic medical center and underwent colonoscopic polypectomy on the same day were enrolled in our study. The odds ratios (ORs) associated with polyp-related and patient-related factors were evaluated using logistic regression analyses. RESULTS: A total of 463 patients and 1,294 neoplastic polyps were analyzed. The miss rates for adenomas, advanced adenomas, and carcinomas were 24.1% (312/1,294), 1.2% (15/1,294), and 0% (0/1,294), respectively. Flat/sessile-shaped adenomas (adjusted OR, 3.62; 95% confidence interval [CI], 2.40–5.46) and smaller adenomas (adjusted OR, 5.63; 95% CI, 2.84– 11.15 for ≤5 mm; adjusted OR, 3.18; 95% CI, 1.60–6.30 for 6–9 mm, respectively) were more frequently missed than pedunculated/sub-pedunculated adenomas and larger adenomas. In patients with 2 or more polyps compared with only one detected (adjusted OR, 2.37; 95% CI, 1.55–3.61 for 2–4 polyps; adjusted OR, 11.52; 95% CI, 4.61–28.79 for ≥5 polyps, respectively) during the first endoscopy, the risk of missing an additional polyp was significantly higher. CONCLUSIONS: One-quarter of neoplastic polyps was missed during colonoscopy. We encourage endoscopists to detect smaller and flat or sessile polyps by using the optimal withdrawal technique.

Factors Predictive of High-Risk Adenomas at the Third Colonoscopy after Initial Adenoma Removal

Evaluating predictive factors for high-risk adenomas at the third colonoscopy based on two prior colonoscopies may help evaluate high-risk adenoma at the third colonoscopy. We analyzed clinical data of 131 patients at Severance Hospital from January 1997 to January 2011. All of them underwent two subsequent colonoscopies after removal of adenomas during an initial colonoscopy. Among 20 patients with high-risk adenoma at the first and second colonoscopies, 10 (50%) patients had high-risk adenoma at the third colonoscopy. Among the 67 patients who had high-risk adenoma only once at the first or second colonoscopy, 15 (22.4%) patients had high-risk adenoma at the third colonoscopy but among the 44 patients without high-risk adenoma at the first and second colonoscopies, only 1 (2.3%) patient had high-risk adenoma at the third colonoscopy (P < 0.001). A multivariate time dependent covariate Cox regression analysis confirmed that high-risk adenoma at the first and/or second colonoscopy (HR, 9.56; 95% CI, 2.37-38.54; P = 0.002) was independent predictor of high-risk adenoma at the third colonoscopy. Given these findings, data from two prior colonoscopies, not one prior examination, may help identify high-risk populations at the third colonoscopy who require careful colonoscopic surveillance.

Anestesia para colonoscopia diagnóstica y terapéutica. Resultados de 9 años de trabajo / Anesthesia for diagnostic and therapeutic colonoscopy. Results of nine years' work

Introducción: la colonoscopia consiste en la exploración endoscópica del intestino grueso, proceder que generalmente se realiza de forma ambulatoria y resulta desagradable y doloroso. Objetivos: identificar las complicaciones de la anestesia general endovenosa para la realización de colonoscopias diagnósticas o terapéuticas y el nivel de satisfacción de los pacientes. Métodos: se realizó una investigación prospectiva, longitudinal, de corte transversal en una serie de pacientes programados de forma electiva para colonoscopia ambulatoria diagnóstica y terapéutica, durante un período de 9 años en el Centro Nacional de Cirugía de Mínimo Acceso. Todos se sedaron con midazolam a 0,01 mg/kg y 0,5 mg de sulfato de atropina por la vía endovenosa (IV). Se les realizó anestesia general endovenosa con propofol 2 a 2,5 mg/kg-1 y 50 µg de fentanil. El mantenimiento se realizó con propofol en infusión continua. La recuperación anestésica se evaluó en rápida, intermedia y tardía, de acuerdo al tiempo de recobro. Las complicaciones se evaluaron de forma dicotómica, presentes o ausentes y se cuantificó su frecuencia. Resultados: se estudiaron 3 854 pacientes. De ellos 3 833 electivos y 21 de urgencia. Fueron diagnósticas 2 984 y terapéuticas 870. Se aplicó anestesia a 3 854 y en 16 pacientes (0,41 %), no se aplicó por negativa del paciente. La recuperación fue rápida en 99 % del total. Solo 25,8 % de los pacientes presentaron alguna complicación. De ellas fueron leves 889 y solo 2 fueron severas. La depresión respiratoria ligera y transitoria fueron las complicaciones más frecuentes (22,3 %). El nivel de satisfacción fue bueno en todos los pacientes. Conclusión: la aplicación de anestesia general endovenosa para la realización de colonoscopia garantiza la seguridad del paciente, sin aumento de la morbilidad y la mortalidad, y permite brindar al paciente un procedimiento sin dolor con aumento de su satisfacción por el proceder.

Introduction: colonoscopy is the endoscopic examination of the large intestine. It is a painful, unpleasant procedure generally carried out on an outpatient basis. Objectives: identify the complications caused by general intravenous anesthesia in diagnostic or therapeutic colonoscopies and determine the degree of patient satisfaction. Methods: a cross-sectional prospective longitudinal study was conducted of a series of patients scheduled for elective outpatient diagnostic/therapeutic colonoscopy at the National Center for Minimal Access Surgery in a period of nine years. All patients were sedated with midazolam at a dose of 0.01 mg/kg and 0.5 mg atropine sulfate intravenously. General intravenous anesthesia was used which consisted of 2 to 2.5 mg/kg-1 propofol and 50 µg fentanyl. Maintenance was provided with a continuous infusion of propofol. Anesthetic recovery was classified as rapid, intermediate or late based on recovery time. Complications were classified dichotomically as present or absent, and quantification was conducted of their frequency. Results: 3 854 patients were studied, of whom 3 833 were elective and 21 emergency. 2 984 colonoscopies were diagnostic and 870 therapeutic. Anesthesia was given to 3 854 patients. In 16 cases (0.41 %) it was not administered due the patients' refusal. Recovery was rapid in 99 % of the cases. Only 25.8 % of the patients had complications. Of these 889 were mild and only 2 severe. Slight and transient respiratory depression was the most common complication (22.3 %). Patient satisfaction was high in all cases. Conclusion: the use of general intravenous anesthesia for colonoscopy ensures patient safety without a rise in morbidity and mortality, and constitutes a painless procedure raising patient satisfaction.