Impact of 3-second rule for high confidence assignment on the performance of endoscopists for the real-time optical diagnosis of colorectal polyps.

BACKGROUND: Confusion between high and low confidence decisions in optical diagnosis hinders the implementation of real-time optical diagnosis in clinical practice. We evaluated the effect of a 3-second rule (decision time limited to 3 seconds for a high confidence assignment) in expert and nonexpert endoscopists. METHODS: This single-center prospective study included eight board-certified gastroenterologists. A 2-month baseline phase used standard real-time optical diagnosis for colorectal polyps < 10 mm and was followed by a 6-month intervention phase using optical diagnosis with the 3-second rule. Performance, including high confidence accuracy, and Preservation and Incorporation of Valuable Endoscopic Innovations (PIVI) and Simple Optical Diagnosis Accuracy (SODA) thresholds, was measured. RESULTS: Real-time optical diagnosis was performed on 1793 patients with 3694 polyps. There was significant improvement in high confidence accuracy between baseline and intervention phases in the nonexpert group (79.2 % vs. 86.3 %; P = 0.01) but not in the expert group (85.3 % vs. 87.5 %; P = 0.53). Using the 3-second rule improved the overall performance of PIVI and SODA in both groups. CONCLUSIONS: The 3-second rule was effective in improving real-time optical diagnosis performance, especially in nonexperts.

Efficacy of oral sulfate tablets for bowel preparation and adenoma detection rate.

BACKGROUND AND AIM: The adenoma detection rate (ADR), which is closely related to bowel preparation, is the most important factor for colonoscopy quality assessment. New oral sulfate tablets (OSTs) have been developed to improve bowel preparation compliance. This study evaluated the efficacy of OSTs in terms of the ADR and bowel preparation status. METHODS: Medical records of subjects under the age of 65 who underwent colonoscopy from March 2019 to February 2021 were retrospectively reviewed. Polyethylene glycol with ascorbic acid (PEG-A) was used as a bowel preparation for the first half of the study period, and OSTs were used for the second half. In total, 16 971 subjects were included in the study: 9199 (54.2%) used PEG-A, and 7772 (45.8%) used OSTs. Bowel cleansing quality was assessed by the Boston Bowel Preparation Scale (BBPS). RESULTS: The average age was 50 years. The rate of adequate bowel preparation was higher in the OST group than in the PEG-A group (97.2% vs 95.0%, P < 0.001). The mean BBPS was also higher in the OST group (8.02 vs 7.75, P < 0.001). The adenomas per colonoscopy (APC), the ADR and the sessile serrated polyp detection rate (SSPDR) were higher in the OST group than in the PEG-A group (APC 0.56 ± 1.01 vs 0.48 ± 0.91, P < 0.001; ADR 34.5% vs 30.7%, P < 0.001; SSPDR 5.2% vs 3.3%, P < 0.001). CONCLUSIONS: Compared with PEG-A, OSTs yielded superior APC, ADRs, SSPDRs, and better bowel cleanliness. Therefore, OSTs are a good alternative for patients who have difficulty taking large-volume bowel preparation formulations.

Chronic intermittent hypoxia impacts the olfactory nervous system in an age-dependent manner: pilot study.

PURPOSE: Obstructive sleep apnea (OSA) is characterized by repetitive upper airway collapse during sleep, which induces chronic intermittent hypoxia (CIH). CIH results in low-grade inflammation, sympathetic overactivity, and oxidative stress. Nevertheless, it remains unclear how exposure to CIH affects olfaction. The purpose of this study was, therefore, to investigate the cytotoxic effects of CIH exposure on mouse olfactory epithelium and the underlying pathophysiology involved. METHODS: Mice were randomly divided into four groups: Youth mouse (You) + room air (RA), You + intermittent hypoxia (IH), Elderly mouse (Eld) + RA, and Eld + IH (n = 6 mice/group). Mice in the two hypoxia groups were exposed to CIH. The control condition involved exposure to room air (RA) for 4 weeks. Olfactory neuroepithelium was harvested for histologic examination, gene ontology analysis, quantitative real-time polymerase chain reaction (qRT-PCR), and western blotting. RESULTS: Based on qRT-PCR analysis, olfactory marker protein (OMP), Olfr1507, ADCY3, and GNAL mRNA levels were lower, whereas NGFR, CNPase, NGFRAP1, NeuN, and MAP-2 mRNA levels were higher in the You + IH group than in the You + RA group. Olfactory receptor-regulated genes, neurogenesis-related genes and immunohistochemical results were altered in nasal neuroepithelium under CIH exposure. CONCLUSIONS: Based on genetic and cytologic analysis, CIH impacted the olfactory neuroepithelium in an age-dependent manner. Our findings suggest that CIH-induced damage to the olfactory neuroepithelium may induce more severe change in the youth than in the elderly.

Small sessile serrated polyps might not be at a higher risk for future advanced neoplasia than low-risk adenomas or polyp-free groups.

BACKGROUND: Polypectomy surveillance colonoscopy is recommended according to the risk stratification of initially removed polyps. This study aimed to evaluate the risk of advanced neoplasia following low-risk SSPs compared with that following LRAs and polyp-free groups. MATERIALS AND METHODS: From September 2013 to August 2017, asymptomatic Koreans aged 50-75 years who underwent surveillance colonoscopy post-baseline colonoscopy were enrolled. The 1314 participants who met the study design criteria were stratified into three groups according to the presence of LRAs or low-risk SSPs. The rate of advanced neoplasia was then compared between groups by surveillance colonoscopy. RESULTS: A total of 1314 participants were classified according to baseline colonoscopy findings: no polyp (n = 551), LRA (n = 707), and low-risk SSP (n = 56). All participants underwent surveillance colonoscopy after an average of 28.1 ± 8.7 months. The rate of advanced neoplasia at surveillance was not different between groups: no polyp group (13/551, 2.4%), LRA group (27/707, 3.8%), and low-risk SSP group (0/56, 0%). The LRA group exhibited a significantly higher rate of low- and high-risk polyps (47.5, 13.4%) than did the no polyp (35.6, 7.4%, p < .001, p = .001), but no significant differences to the low-risk SSP group (35.7, 7.1%, p = .117, p = .253), respectively. CONCLUSIONS: Patients with low-risk SSPs were not at a higher risk of advanced neoplasia than LRA patients, even in the polyp-free group. We suggest that surveillance colonoscopy after the removal of low-risk SSPs is not required more often than for LRAs.

Impact of comprehensive optical diagnosis training using Workgroup serrAted polypS and Polyposis classification on detection of adenoma and sessile serrated lesion.

OBJECTIVES: Many interventions have been attempted to improve adenoma detection rate (ADR) and sessile serrated lesion detection rate (SDR), and one of these interventions is educational training to recognize polyp characteristics. This study aimed to investigate the change in polyp detection rates of endoscopists before and after comprehensive training through the Gangnam-Real Time Optical Diagnosis (Gangnam-READI) program. METHODS: Fifteen gastroenterologists participated in a 1-year comprehensive training program that consisted of ex vivo and in vivo training that encompasses knowledge and skills in endoscopic characterization of colonic polyps using the Workgroup serrAted polypS and Polyposis (WASP) classification. We evaluated the impact of the training program by comparing the overall and individual ADR and SDR 6 months before and after the training. RESULTS: Overall, 18,280 polyps (9337 adenomas and 855 sessile serrated lesion) were collected. The optical diagnosis training had no significant impact on the difference in ADR after training compared to before training (47.7% vs. 46.5%, P = 0.608). A tendency for a decrease in ADR variance was noted among the endoscopists after training (74.9 vs. 32.7, P = 0.121). The overall pre-training period SDR was 4.5% and showed a statistically significant increase to 5.6%, 8.0%, and 7.1% in the first and second half of the training period, and post-training period, respectively (P = 0.003). The optical diagnosis training did not decrease variance in SDR (8.9 vs. 8.8, P = 0.985). CONCLUSION: Comprehensive optical diagnosis training with WASP classification has a significant impact on increasing the overall SDR of expert endoscopists.

Improved Accuracy in Optical Diagnosis of Colorectal Polyps Using Convolutional Neural Networks with Visual Explanations.

BACKGROUND & AIMS: Narrow-band imaging (NBI) can be used to determine whether colorectal polyps are adenomatous or hyperplastic. We investigated whether an artificial intelligence (AI) system can increase the accuracy of characterizations of polyps by endoscopists of different skill levels. METHODS: We developed convolutional neural networks (CNNs) for evaluation of diminutive colorectal polyps, based on efficient neural architecture searches via parameter sharing with augmentation using NBIs of diminutive (≤5 mm) polyps, collected from October 2015 through October 2017 at the Seoul National University Hospital, Healthcare System Gangnam Center (training set). We trained the CNN using images from 1100 adenomatous polyps and 1050 hyperplastic polyps from 1379 patients. We then tested the system using 300 images of 180 adenomatous polyps and 120 hyperplastic polyps, obtained from January 2018 to May 2019. We compared the accuracy of 22 endoscopists of different skill levels (7 novices, 4 experts, and 11 NBI-trained experts) vs the CNN in evaluation of images (adenomatous vs hyperplastic) from 180 adenomatous and 120 hyperplastic polyps. The endoscopists then evaluated the polyp images with knowledge of the CNN-processed results. We conducted mixed-effect logistic and linear regression analyses to determine the effects of AI assistance on the accuracy of analysis of diminutive colorectal polyps by endoscopists (primary outcome). RESULTS: The CNN distinguished adenomatous vs hyperplastic diminutive polyps with 86.7% accuracy, based on histologic analysis as the reference standard. Endoscopists distinguished adenomatous vs hyperplastic diminutive polyps with 82.5% overall accuracy (novices, 73.8% accuracy; experts, 83.8% accuracy; and NBI-trained experts, 87.6% accuracy). With knowledge of the CNN-processed results, the overall accuracy of the endoscopists increased to 88.5% (P < .05). With knowledge of the CNN-processed results, the accuracy of novice endoscopists increased to 85.6% (P < .05). The CNN-processed results significantly reduced endoscopist time of diagnosis (from 3.92 to 3.37 seconds per polyp, P = .042). CONCLUSIONS: We developed a CNN that significantly increases the accuracy of evaluation of diminutive colorectal polyps (as adenomatous vs hyperplastic) and reduces the time of diagnosis by endoscopists. This AI assistance system significantly increased the accuracy of analysis by novice endoscopists, who achieved near-expert levels of accuracy without extra training. The CNN assistance system can reduce the skill-level dependence of endoscopists and costs.

Longer Withdrawal Time Is More Important than Excellent Bowel Preparation in Colonoscopy of Adequate Bowel Preparation.

BACKGROUND: Adequate bowel preparation is crucial for effective screening colonoscopy. However, it is unclear whether higher bowel preparation scores correspond to beneficial effects on the adenoma and polyp detection rate (ADR and PDR) in the adequate bowel preparation group. AIMS: This study aimed to evaluate the effects of bowel preparation, according to the Boston Bowel Preparation Scale (BBPS), and colonoscopy withdrawal time (CWT) on ADR and PDR in the adequate bowel preparation group. METHODS: Healthy examinees between 50 and 75 years old who underwent colonoscopy between September 2015 and August 2016 were included. BBPS scores, CWT, ADR, and PDR were reviewed retrospectively. Predictors of ADR and PDR were analyzed with a generalized linear mixed model. RESULTS: A total of 5073 cases with adequate bowel preparation (BBPS ≥ 6) were analyzed. Examinees with good (BBPS = 6, 7) and excellent (BBPS = 8, 9) bowel preparation were 1898 (37.4%) and 3175 (62.6%), respectively. Both ADR and PDR were higher in the good bowel preparation group than in the excellent bowel preparation group (ADR 47.3% vs. 45.0%, P = 0.035; PDR 73.7% vs. 69.5%, P = 0.004, respectively). In the multivariate analysis, CWT, rather than BBPS, was significantly associated with both ADR (OR 1.04; 95% CI 1.02-1.06; P < 0.001) and PDR (OR 1.05; 95% CI 1.02-1.07; P = 0.002). CONCLUSIONS: Both ADR and PDR were lower when bowel preparation was excellent rather than good. However, CWT, not BBPS, was significantly associated with ADR and PDR in the adequate bowel preparation group. Therefore, meticulous inspection is important for high-quality colonoscopy regardless of the BBPS score in examinees with adequate bowel preparation.

Medication-related osteonecrosis of the maxilla: Prognosis of oral surgery combined with endoscopic sinus surgery.

OBJECTIVES: To evaluate the effect of functional endoscopic sinus surgery (FESS) on the resolution of maxillary medication-related osteonecrosis of the jaw (MRONJ). PATIENTS AND METHODS: This study included 62 patients diagnosed with MRONJ in the maxillary posterior area with or without maxillary sinusitis (MS). All patients underwent oral surgery. The concomitant MS was evaluated, and if indicated, FESS was performed on the same operation. Follow-up included clinical and radiological examinations at 4 months postoperation. RESULTS: Of the 62 patients, 24 (38.7%) showed no evidence of MS and 38 (61.3%) showed MS. Advanced MRONJ (stage 3), which has bony destruction of the sinus floor and signs of MS according to its definition, was seen in 27 patients (43.5%). In stage 3 MRONJ, patients with combined treatment of oral surgery and FESS compared to those treated with oral surgery alone showed higher percentage of resolution (84.2%, 37.5%, respectively) at 4 months postoperatively, and the results were statistically significant. CONCLUSION: Simultaneous management of MRONJ and sinusitis with combined treatment of oral surgery and FESS for the treatment of maxillary MRONJ can be an effective method, especially for advanced cases, to address its associated lesions.

Multidirectional Colonoscopy Quality Improvement Increases Adenoma Detection Rate: Results of the Seoul National University Hospital Healthcare System Gangnam Center Colonoscopy Quality Upgrade Project (Gangnam-CUP).

BACKGROUND: To prevent colorectal cancer, high-quality colonoscopy is advocated, undertaken by endoscopists with high adenoma detection rates (ADRs). Despite reports that various factors may impact ADRs, the significance of such factors is still unclear. AIMS: The analysis was aimed at quality-oriented interventions for boosting ADRs. METHODS: Study enrollees were adults subjected to screening colonoscopy between September 2013 and August 2016 at the Gangnam Center of Seoul National University Hospital Healthcare System. The investigation entailed six periods (P1-6) of 6 months each, during which serial multidirectional quality improvement efforts were instituted. In particular, we sought to further educate endoscopists, provide feedback on individual ADRs, and introduce a split-dose regimen, gauging results via the Boston Bowel Preparation Score. Changes in polyp detection rates (PDRs) and ADRs were then analyzed. RESULTS: A total of 13,430 colonoscopies were undertaken by 15 experienced endoscopists. Overall, the ADR increased from 45.6% (P1) to 48.2% (P6, p < 0.001). The PDR, ADR, and advanced adenoma detection rate (AdvADR) showed the greatest increases between P3 and P4 [PDR 67.8% → 71.2% (p < 0.001); ADR 44.1% → 47.7% (p = 0.001); AdvADR 2.3% → 3.3% (p = 0.028)] in keeping with the introduction of a split-dose regimen. The sessile serrated adenoma detection rate (SSADR) increased substantially from 2.1% (P1) to 7.9% (P6, p < 0.001), with the largest gain between P1 and P2, just after education (p = 0.023). CONCLUSIONS: Successful quality improvement in colonoscopy was achieved through comprehensive multidirectional efforts in education, feedback, and enhanced bowel preparation. Achieving high-level bowel preparation was paramount in ADR improvement. The SSADR was improved through education.

Epidemiological Characterization of a Directed and Weighted Disease Network Using Data From a Cohort of One Million Patients: Network Analysis.

BACKGROUND: In the past 20 years, various methods have been introduced to construct disease networks. However, established disease networks have not been clinically useful to date because of differences among demographic factors, as well as the temporal order and intensity among disease-disease associations. OBJECTIVE: This study sought to investigate the overall patterns of the associations among diseases; network properties, such as clustering, degree, and strength; and the relationship between the structure of disease networks and demographic factors. METHODS: We used National Health Insurance Service-National Sample Cohort (NHIS-NSC) data from the Republic of Korea, which included the time series insurance information of 1 million out of 50 million Korean (approximately 2%) patients obtained between 2002 and 2013. After setting the observation and outcome periods, we selected only 520 common Korean Classification of Disease, sixth revision codes that were the most prevalent diagnoses, making up approximately 80% of the cases, for statistical validity. Using these data, we constructed a directional and weighted temporal network that considered both demographic factors and network properties. RESULTS: Our disease network contained 294 nodes and 3085 edges, a relative risk value of more than 4, and a false discovery rate-adjusted P value of <.001. Interestingly, our network presented four large clusters. Analysis of the network topology revealed a stronger correlation between in-strength and out-strength than between in-degree and out-degree. Further, the mean age of each disease population was related to the position along the regression line of the out/in-strength plot. Conversely, clustering analysis suggested that our network boasted four large clusters with different sex, age, and disease categories. CONCLUSIONS: We constructed a directional and weighted disease network visualizing demographic factors. Our proposed disease network model is expected to be a valuable tool for use by early clinical researchers seeking to explore the relationships among diseases in the future.

Improved Real-Time Optical Diagnosis of Colorectal Polyps Following a Comprehensive Training Program.

BACKGROUND & AIMS: The optimal training method for endoscopic characterization of colorectal polyps using narrow-band imaging is uncertain, and sessile serrated lesions (SSLs) optical diagnosis data are lacking. We aimed to evaluate a comprehensive training program for real-time optical diagnosis of colorectal polyps, including SSLs. METHODS: We performed a single-institution prospective study of 15 endoscopists trained with the Workgroup Serrated Polyps and Polyposis classification system. After the first phase of in vivo optical diagnosis, their performances were evaluated. After re-education for insufficient competency, they began the second phase. The learning curves and performance on 2 preservation and incorporation of valuable endoscopic innovations benchmarks were assessed. RESULTS: A total of 7294 polyps, including 486 SSLs, were diagnosed in real-time. The overall accuracy improved from 73.5% in the first phase to 77.1% in the second. The accuracy with high confidence was 79.4% and 85.1% in the first and second phases, respectively. In the first and second phases, the negative predictive values for diminutive neoplastic polyps were 82.1% and 92.5%, respectively, and concordances of the surveillance intervals were 80.7% and 89.7%, respectively. Eight endoscopists achieved the preservation and incorporation of valuable endoscopic innovations benchmarks after the second phase compared with none after the first. In contrast, the high confidence rate decreased from 74.6% to 70.2% as training progressed. CONCLUSION: A comprehensive training program for real-time optical diagnosis significantly improved performance and reduced individual variability in less-experienced endoscopists. ClinicalTrials.gov no: NCT02516748.

Treatment outcomes and recurrence following standard cold forceps polypectomy for diminutive polyps.

BACKGROUND: The recurrence rate after standard cold forceps polypectomy (CFP) of diminutive polyps of ≤5 mm has not been fully determined. The aim of this study was to analyze the long-term follow-up results and recurrence rate after CFP of diminutive polyps. METHODS: We retrospectively reviewed the medical records of 884 (738 men; age 53 years) asymptomatic subjects who underwent surveillance colonoscopy after CFP of 1-2 diminutive adenomatous polyps. Cumulative recurrence at the CFP site and risk factors for recurrence were analyzed. RESULTS: Overall recurrence over 59.7 months was 17 % after CFP of 1111 diminutive polyps. The rate of definite recurrence was 4 %, and probable recurrence was 13 %. Recurrence as advanced adenoma was 0.5 % (5/1111). The cumulative probabilities of recurrence at 3, 5, and 7 years after CFP were 10.0, 16.0, and 21.1 %, respectively. Multivariate analysis revealed that polyp 4-5 mm in size and right colonic polyp were risk factors for recurrence (hazard ratio [HR] 1.37; 95 % confidence interval [CI] 1.01-1.86 and HR 1.49; 95 % CI 1.08-2.04, respectively). The recurrence rate for 10 endoscopists who performed at least 50 CFPs ranged from 11.0 to 25.2 %; the probability of recurrence in those in the top half in terms of recurrence rate was 1.6-fold higher than that of those in the bottom half (95 % CI 1.17-2.19). CONCLUSIONS: Although recurrence may develop after standard CFP of diminutive polyps, recurrence as advanced adenoma is rare. Large polyp size, right colon polyp, and endoscopist are risk factors for recurrence after standard CFP.

Optimized hybrid endoscopic submucosal dissection for colorectal tumors: a randomized controlled trial.

BACKGROUND AND AIMS: Colorectal endoscopic submucosal dissection (ESD) is difficult and time consuming. Optimization of ESD with snaring (optimized hybrid ESD) may shorten the procedure time. The purpose of this study was to prospectively compare ESD and optimized hybrid ESD in the colorectum. METHODS: We prospectively enrolled 70 patients with colorectal neoplasia ≥20 mm. The patients were randomized to receive either ESD (36 patients) or optimized hybrid ESD (34 patients). In the optimized hybrid ESD group, snare resection was performed after an adequate amount of submucosal dissection. The primary outcome was procedure time. Secondary outcomes were en bloc and complete resection rates and adverse event rates. RESULTS: ESD could not be completed in 5 patients (13.9%) in the ESD group because of technical difficulties. We tried hybrid ESD to finish the resection, and en bloc resection was achieved in 4 patients (80%). The mean procedure time was shorter in the optimized hybrid ESD group compared with the ESD group (27.4 vs 40.6 minutes; P = .005). The en bloc resection rates were similar (94.1% vs 100%; P = .493), as were the complete resection rates (91.2% vs 93.5%; P > .999) and perforation rates (3 patients [8.8%] vs 2 patients [6.5%]; P > .999). CONCLUSIONS: Optimized hybrid ESD achieves shorter procedure times than ESD, with similar en bloc resection rates and adverse event rates. Optimized hybrid ESD in the colorectum may offer an easy alternative to colorectal ESD and a rescue method for failed ESD cases. ( CLINICAL TRIAL REGISTRATION NUMBER: NCT01944540.).

Clinical outcomes of endoscopic submucosal dissection for large colorectal neoplasms: a comparison of protruding and laterally spreading tumors.

BACKGROUND AND AIMS: The therapeutic outcome of endoscopic submucosal dissection (ESD) for large protruding tumors has not yet been evaluated. We aimed to compare the outcomes of ESD in protruding tumors with those of laterally spreading tumors (LSTs). METHODS: Endoscopic submucosal dissection was attempted in 218 patients with 220 colorectal tumors ≥30 mm in diameter (67, protruding tumors; 153, LSTs) from July 2007 to June 2014. We retrospectively reviewed patient medical records, therapeutic outcomes, and procedure-related adverse events. This study defined lesions with a height of 10 mm or more as protruding tumors and those with a height under 10 mm as LSTs. RESULTS: The mean lesion diameter, height, and volume were 43.8, 9.5 mm, and 13.6 cm(3), respectively. The mean procedure time was 75.5 min. Deep submucosal cancer was more frequent in protruding tumors than in LSTs (11.9 vs. 2.6%, P = 0.005). Severe fibrosis was more common in protruding tumors than in LSTs (19.4 vs. 3.9%, P < 0.001). En bloc resection and complete resection rates were lower in protruding tumors than in LSTs (en bloc resection, 76.1 vs. 92.8%, P = 0.001; complete resection, 64.2 vs. 79.1%, P = 0.020). Intra- and post-procedural bleeding were more frequent in protruding tumors than in LSTs (22.4 vs. 2.6%, P < 0.001; 6.0 vs. 0.7%, P = 0.031, respectively). By multivariate analysis, protruding tumor morphology (odds ratio 1.919, P = 0.048) and tumor size ≥60 mm (odds ratio 2.490, P = 0.030) were associated with incomplete resection. CONCLUSIONS: Endoscopic submucosal dissection for protruding tumors is less effective than ESD for LSTs, with lower rate of complete resection occurring with protruding tumors.

Clinical features and treatment outcomes of dental implant-related paranasal sinusitis: A 2-year prospective observational study.

OBJECTIVES: As dental implant-related paranasal sinusitis has different pathophysiology and clinical features from primarily rhinogenic paranasal sinusitis, the standard treatment protocol for dental implant-related paranasal sinusitis has not yet been established. The aim of this study was to analyze the clinical characteristics and treatment results of dental implant-related paranasal sinusitis. MATERIAL AND METHODS: We conducted a prospective single-center study of 19 patients who were treated for odontogenic sinusitis developing in relation to dental implant from September 2008 through May 2012. The age of the patients ranged from 33 to 78 years, with the mean age of 54.5 years. Foul odor and postnasal dripping were the two most common complaints. All patients underwent nasal endoscopic examination and paranasal sinus CT before treatment, and initial conservative treatment for 1 week. Patients unresponsive to medical treatment underwent endoscopic sinus surgery (ESS). All patients were classified into the conservative and surgical groups for analysis and followed up for 2 years after initial diagnosis. RESULTS: Four patients (21%) were successfully treated conservatively, while 15 patients (79%) underwent surgical treatment. One of these 15 patients required revision surgery. After 2 years, all patients were successfully treated, so there were no more clinical signs of recurrent sinusitis in any patients. The survival rate of implants was 100%. Compared to those of the conservative group, symptom duration, the Lund-MacKay CT score, status of the ostiomeatal unit (OMU), and the condition of the maxillary sinus floor were significantly more severe in the surgical group. CONCLUSION: In our study, the majority of patients who once developed paranasal sinusitis associated with dental implants required surgical treatment. Findings of paranasal sinus CT may be important in determining treatment option.

Coblation nasal septal swell body reduction for treatment of nasal obstruction: a preliminary report.

In this paper, we present the results of coblation nasal septal swell body (NSB) reduction for the treatment of nasal obstruction in patients with abnormally thickened NSB. The study design was a retrospective clinical series conducted at a single tertiary medical center. Eight patients underwent coblation NSB reduction. Pre-operative and post-operative nasal functions were evaluated by acoustic rhinometry and subjective symptom scales. We also analyzed pre-operative CT scan images and nasal endoscopic findings. The mean maximal NSB width was 16.4 ± 2.2 mm on pre-operative coronal CT scan images. The mean visual analog scale score for nasal obstruction was decreased from preoperative 7.63 ± 0.99 points to 3.88 ± 0.92 points (postoperative 3 months), 4.16 ± 0.78 points (postoperative 6 months), and 4.63 ± 0.69 points (postoperative 1 year). Six out of the eight patients were satisfied with the clinical outcome at 1 year after the procedure. To the best of our knowledge, coblation NSB reduction has not yet been reported in the medical literature. Our results show that it can be an effective treatment modality for nasal valve narrowing in patients with abnormally thickened NSB.

The diagnostic value of a digital rectal examination compared with high-resolution anorectal manometry in patients with chronic constipation and fecal incontinence.

OBJECTIVES: Digital rectal examination (DRE) is a simple clinical method to diagnose anorectal disorders. High-resolution antorectal manometry (HRAM) based on a spatiotemporal plot is expected to promote improved diagnostic accuracy. However, there are no reports comparing the effectiveness of DRE and HRAM. The aim of our study was therefore to evaluate the diagnostic value of DRE compared with HRAM. METHODS: A total of 309 consecutive patients with chronic constipation (n=268) or fecal incontinence (n=41) who underwent a standardized DRE, HRAM, and balloon expulsion test were enrolled in this study. The diagnostic yield of DRE compared with HRAM was determined, and agreement between DRE and HRAM data was evaluated. RESULTS: Of the constipated patients, 207 (77.2%) were diagnosed with dyssynergia using HRAM. The sensitivity, specificity, and positive predictive value of DRE in the diagnosis of dyssynergia were 93.2%, 58.7%, and 91.0%, respectively, and moderate agreement was seen between the two modalities (κ-coefficient =0.542, P<0.001). In patients with fecal incontinence, there was moderate agreement in terms of anal squeeze pressure between the two modalities (κ-coefficient =0.418, P=0.006); however, there was poor agreement for anal resting tone (κ-coefficient =0.079, P=0.368). CONCLUSIONS: DRE shows high sensitivity and positive predictive value in detecting dyssynergia compared with HRAM, and could therefore be used as a bedside screening test for the diagnosis of this disorder. Further studies are warranted to evaluate the correlation between DRE and HRAM in assessing anal sphincter pressure.

Factors associated with the outcomes of endoscopic submucosal dissection in pyloric neoplasms.

BACKGROUND: Pyloric neoplasms are one of the most technically difficult lesions to remove by endoscopic submucosal dissection (ESD). OBJECTIVE: To evaluate the therapeutic outcomes of ESD in pyloric neoplasms according to clinicopathologic characteristics and to assess predictive factors for incomplete resection. DESIGN: A retrospective, single-center study. PATIENTS: A total of 110 cases of pyloric adenomas and early cancers treated with ESD from January 2007 to May 2013 were included. INTERVENTION: ESD procedures with or without retroflexion maneuver were used in all qualifying cases. MAIN OUTCOME MEASUREMENTS: Therapeutic outcomes of ESD and procedure-related adverse events. RESULTS: Complete resection rates differed significantly in relation to location (pylorus vs pylorus with duodenal extension, 79% vs 58%), directional distribution (upper hemisphere vs lower hemisphere of the pylorus, 67% vs 90%), tumor size (≤ 10 mm vs > 10 mm, 84% vs 67%), and circumferential extent of pyloric mucosal resection (≤ 1/2 vs > 1/2, 92% vs 62%). On multivariate analysis, tumor location (pylorus with duodenal extension; odds ratio 5.747), hemispheric distribution (upper hemisphere; odds ratio 4.906), and circumferential extent of resection (> 1/2; odds ratio 3.960) were independent factors associated with incomplete resection. The rates of procedure-related bleeding, stenosis, and perforation were 8%, 1%, and 1%, respectively; none of the adverse events required surgical intervention. LIMITATIONS: Single-center, retrospective study. CONCLUSIONS: ESD is a safe, effective, and feasible treatment for pyloric neoplasms. However, the complete resection rate decreases for tumors that have duodenal extension, are located in the upper hemisphere, and have large circumferential extent of resection.

The risk of colorectal cancer in inflammatory bowel disease: a hospital-based cohort study from Korea.

OBJECTIVE: Limited data are available on the incidence and risk factors of colorectal cancer (CRC) in Asian patients with inflammatory bowel disease (IBD). MATERIAL AND METHODS: Information on 5212 Korean patients with IBD (2414 with Crohn's disease [CD] and 2798 with ulcerative colitis [UC]) was retrieved from the IBD registry of Asan Medical Center. Data on CRC incidence for the entire Korean population were derived from the Korean Statistical Information Service. RESULTS: During 39,951 person-years of follow-up (17,679 for CD and 22,272 for UC), 30 patients (12 with CD and 18 with UC) developed CRC. The standardized incidence ratio (SIR) of CRC was 6.0 (95% confidence interval [CI], 3.10-10.48) for CD and 1.68 (95% CI, 1.00-2.66) for UC; it was 9.69 (95% CI, 5.01-16.93) for CD with colonic involvement and 4.31 (95% CI, 2.46-7.00) for extensive UC. The SIR was also increased in patients diagnosed with IBD at younger than 30 years old. CRC location was the low rectum in 11 of 12 CD patients (91.7%). The cumulative probability of rectal cancer was higher in CD patients with a perianal fistula than in those without a perianal fistula (p = 0.02). CONCLUSIONS: A high prevalence of perianal fistulas in Korean CD patients may be the cause of the predominance of low rectal cancer in this population and the higher SIR of CRC in Koreans than in Westerners. In contrast, the SIR of CRC in Korean UC patients may be similar to that in Western UC patients.

Appendectomy and the clinical course of ulcerative colitis: a retrospective cohort study and a nested case-control study from Korea.

BACKGROUND AND AIM: Appendectomy protects against the development of ulcerative colitis (UC). However, the relationship between appendectomy and the clinical course of UC is complex, and could be impacted by a number of variables. The aim of this study was to compare the clinical course of UC between appendectomized patients and nonappendectomized patients in Korea. METHODS: Data on 2648 UC patients were retrieved from the Inflammatory Bowel Disease registry at Asan Medical Center. This retrospective cohort study compared the clinical course of UC in 68 patients who received an appendectomy before their UC diagnosis and 2544 patients who did not receive this procedure. A nested case-control study was also conducted to compare the disease course before and after appendectomy in 36 patients who received this surgery after UC diagnosis. To control for potential confounders, 144 matched controls were retrieved from among 2544 nonappendectomized patients RESULTS: In the retrospective cohort study, an appendectomy before UC diagnosis demonstrated no influence on disease extent at diagnosis, rates of medication use, proximal disease extension, or colectomy. The 10- and 20-year probabilities of receiving a colectomy were 12.7% and 20.6%, respectively, in appendectomized patients, in comparison with 8.9% and 16.4%, respectively, in nonappendectomized patients (P = 0.81). According to the nested case-control study, an appendectomy after UC diagnosis did not change the subsequent disease course in terms of medication use, proximal disease extension, or hospital admission rate. The adjusted ratio of hospital admissions after appendectomy versus before appendectomy was 1.01 (95% confidence interval = 0.46-2.23; P = 0.97). CONCLUSIONS: Appendectomies performed before or after UC diagnosis do not affect its clinical course in the Korean population.