Colonoscopy Quality Control:a Single Center Study

Background:Colorectal cancer is one of the most common malignant tumors, whose incidence increasing continuously. It is a major clinical assignment to find efficient methods to reduce the morbidity and mortality of colorectal cancer in China. At present, colorectal cancer screening with endoscopic management of early colorectal cancers and precancerous lesions is an effective approach to fulfill these goals.Regardless of screening strategies, colonoscopy and subsequent endoscopic resection of detected lesions are the core steps of management. At the beginning of the 21st century, USA started to evaluate the quality of colonoscopy and gradually established a colonoscopy quality control system with several important quality indicators such as adenoma detection rate, cercal intubation rate and withdrawal time. The quality control system had improved the total quality of colonoscopy around America and guaranteed the high-efficiency operation of colorectal cancer screening programme. Some European counties also pay attention to colonoscopy quality followed fecal occult blood test (FOBT) colorectal cancer screening, which contain three domains of colonoscopy quality assessment:colonoscopy technical, patient safety and patient experience. These multiple-dimensional quality control strategy is worthwhile being referred and studied by Chinese scholars.According to recent digestive endoscopic technique census of China, there were 5.832 million colonoscopies estimated to be performed per year, which account for nearly 20% of total endoscopic procedures. The volume of colonoscopy is expected to further increase accompany to rising up of colorectal cancer incidence. As colonoscopy quality was rarely reported in China, we aimed to study colonoscopy quality from a macro standpoint and through two entry points to have a restricted view of colonoscopy qualities based on an endoscopic database of tertiary affiliated teaching hospitals.Part1. Colonoscopy quality measures for the FOBT-positive patients in Shanghai Bowel Cancer Screening Programme:a single center study.Objective:Using international quality indicators to measure quality of colonoscopy in our hospital for FOBT-positive patients in Shanghai bowel cancer screening programme in order to provide baseline data and analyze influence factors associated with colonoscopy quality.Methods:It is a retrospective single center study. We colected and quantitatively analysis colonoscopic data of FOBT-positive patients between July 2013 and July 2014 in Changhai digestive endoscopy center.Results:From July,2013 to July,2014, there were 222 cases met the inclusion criteria. Cecum intubation rate was 97.7%,mean withdrawal time was 3.3min,total polyp detection rate was 46.4%, total detection rate of adenoma and advanced adenoma was 19.8% and 9.9% respectively. Most lesions associated indicators in men were higher than women. The higher proportion of women(63.5%) may result in a significate underestimate of total adenoma detection rate. Complication rates of therapeutic colonoscopy was 2.8%. Total polyp retrieval rate was 64.0%. Diminutive polyp size (OR=15.256,95%CI 4.159-55.957), rectal location (OR=3.663,95%CI 1.427-9.398) and polyps amount more than 2 (OR=3.988,95%CI 1.562-10.187) were found to be independent factors related to polpys resection without retrieval. An unnegligible porpotion of patients did not receive endoscopic resection without delay.Conclusions:Our endoscopy center provides a relatively reliable colonoscopy for colorectal cancer screening program in Shanghai, and most quality indicators meet international standards. Some deficiencies are disclosed:(1) Withdrawal time is relatively short, which may lead to significant polyps miss rate; (2) Relatively low polyp retrieval rate may hinder the accurate caculation of ADR; (3) Some patients did not get endoscopy therapy in time. (4) Using retired age as inclusion criteria for both genders may reduce efficiency of screening. Our results provide baseline data and rational counter-measures for colonoscopy quality and screening programme improvement. Part 2. Survey on Clinical Manifestations, Prognosis and Differential Diagnosis of Post-polypectomy Syndome Objective:Based on digestive endoscopy database and PACS image system, we analysis the incidence, clinical manifestations, prognosis and differential diagnosis of Post-polypectomy Syndome (PPS).Methods:It is a retrospective single center study. We collect therapeutic colonoscopy data of in-patients in our center between January 2011 and July 2014 and make diagnosis according to definition of PPS based on clinical and image data.Results:our center finished 9407 cases of colonoscopy polypectomy (exclude those involved special electric knives).21 patients were diagnosed PPS, that is, the incidence of PPS in common polypectomy (including hot biopsy forceps, polypectomy with electric snare and EMR) is 2.23/1000(21/9407). All the 21 patients showed fever and abdominal pain, 73.7%(14/19) for leukocytosis. Typical images are air in the bowel wall but not within the peritoneum, focal thickening of the colonic wall and peri-luminal fat stranding. The differential diagnoses include acute abdominal conditions, such as perforation, acute appendicitis, urinary calculi, etc. All the patients recovered after conservative managements such as fasting, rehydration, antibiotics without surgical intervention.Conclusions:In our endoscopy center, incidence of PPS is 2.23/1000(21/9407). PPS is a rare complication. When make diagnosis, we should rule out other acute abdominal conditions. Patients usually recovered after conservative treatments without surgery, prognosis of these patients is excellent.Part 3. Risk factors of Post-polypectomy Syndome:single center matched case-control studyObjective:Identify risk factors of PPS by matched case-control study in order to predict and prevent PPS in clinical setting.Methods:Triple as many controls as cases were randomly selected from the remaining study cohort and matched with each case for age (± 2 years) and sex (3:1 matching), The following retrospective data were collected for each PPS patient and control:age, sex, alcohol consumption, smoking, co-morbid diseases, body mass index (BMI), laboratory data, clinical presentations, clinical outcomes, medical treatment, endoscopic data and histopathology, use conditional multivariate logistic regression model to identify independent risk factors for PPS.Results:Univariate analysis results show that PPS group may contain hypertension (p=0.008), longer operation time (p=0.004), piecemeal resection (p=0.012), larger diameter (p=0.018), the largest lesion located in the right-side colon (p=0.008), nonpolypoid feature (p=0.008)and laterally spreading tumor (p=0.005). Conditional multivariate logistic regression results show that hypertension (OR=4.406,95%CI 1.086-17.877), lesion≥ 15mm (OR=5.300,95%CI 1.171-23.992) and nonpolypoid lesions (OR=3.632,95%CI 1.092-12.079) are independent risk factors of PPS, largest lesion located in the right-side colon might have trend associated with PPS.Conclusion:Hypertension, lesion≥15mm and nonpolypoid lesions are independent risk factors of PPS. More attention should be taken to the patients with one or more risk factors of PPS and post-procedure observation should be more cautiously.Part 4. A single center retrospective study of serrated polyposis syndrome in Chinese.Objective:Estimate the possible incidence of serrated polyposis syndrome(SPS) in Chinese based on database of Changhai Digestive Endoscopy Center and describe the characters of SPS.Methods:Search the database of Changhai digestive endoscopy center between January 1984 and July 2014 for any procedure which contain at least one pathologically confirmed serrated lesion, cumulate the total number of serrated lesions and diagnose SPS based on WHO criteria. If any case of SPS were identified, telephone call were make in order to get exact family history of suspected hereditary polyposis, colorectal cancer or any other extrocolonic cancers.Results:There were 18687 records with at least one pathological confirmed serrated lesion. Upon rigorous calculation,36 cases of SPS were found, in whom 31 cases (86.1%) meet the WHO criteria 1. Ten cases (27.8%) fulfill the WHO criteria 3 and 5 cases (5/36,13.9%) meet both the WHO criteria 1 and 3. Total polyp retrieval rate of these 36 cases was 54.1% (710/1312). There were 12 cases of colorectal cancers occurred in this group of patients. Among them,9 colorectal cancers took place before fulfill any of the WHO criteria. One cancer were diagnosed just the same time when the patient was confirmed SPS. Three cancers were identified during the surveillance period after colorectal polyps removed. Three cases with colorectal cancer also found concomitant extrocolonic cancer. Among SPS patients who can get exact family history,46.2%(6/13) offered positive family history. Four of their first-degree relatives (4/13,30.8%) contain colorectal cancers and 2 have extracolonic cancer (2/13,15.4%).Conclusion:SPS is a very rare polyposis syndrome in Chinese (1.2/year or 1case per 0.8)。 SPS cases and their first degree relatives may suffer from increased colorectal and extrocolonic cancer risks,. "Resect and discard" strategy, which directly lead to low polyp retrieval rate, may delay the diagnosis of SPS and even miss an unnegligible porpotion of SPS, especially who should have met WHO criteria 3. Improving clinicians’ and pathologists’ recognition of SPS is an organic component of colonoscopy quality continuous improving programme.