Accuracy of magnetic resonance imaging in defining dentate line in anal fistula.

PURPOSE: To retrospectively assess the accuracy of magnetic resonance imaging (MRI) in defining dentate line in anal fistula. MATERIALS AND METHODS: Seventy patients with anal fistulas were assessed by dynamic contrast-enhanced MRI. The distance from the dentate line to the anal verge for all patients was measured by MRI. To mitigate interference, 35 patients with anal fistulas whose internal openings were located on the dentate line were excluded from this study. Two observers independently judged the positional relationship between the internal opening and the MRI-defined dentate line, and compared with the results observed by surgeon to assess the accuracy. RESULTS: The distance between the MRI-defined dentate line and the anal verge depended on the location of the internal opening and the morphology of the anal canal mucosa. The distance based on the location the internal opening and the morphology of the anal canal mucosa was 18.2 ± 8.1 mm and 20.0 ± 5.3 mm on oblique coronal T2WI, respectively. Compared with the results observed by the surgeon, the accuracy of evaluating the positional relationship between the internal opening and the dentate line from the morphology of the anal canal mucosa on MRI exceeded 89.9%. Taking 18.2-20.0 mm as the distance between the dentate line and the anal verge on the MRI image, the accuracy of evaluating the relationship between the position of the internal opening and the dentate line was over 85.7%. Considering both the dentate line and the anal canal mucosa, the accuracy of evaluating the relationship between the internal opening and the dentate line was over 91.5%. The results of MRI-defined dentate line were in good agreement with the results of intraoperative surgeon evaluation, and the κ values were 0.70, 0.63, and 0.78, respectively. CONCLUSION: MRI has high accuracy in defining the dentate line in anal fistulas.

Dentate line invasion as a predictive factor of poor distant relapse-free survival in locally advanced lower rectal cancer with anal sphincter involvement.

BACKGROUND: While an important surgical landmark of the dentate line has been established for locally advanced lower rectal cancer (LALRC), the prognostic significance of dentate line invasion (DLI) has not been well defined. This study aimed to explore the impact of DLI on prognosis in LALRC patients with anal sphincter involvement after neoadjuvant chemoradiotherapy followed by surgery. METHODS: We analyzed 210 LALRC patients and classified them into DLI group (n = 45) or non-DLI group (n = 165). The exact role of DLI in survival and failure patterns was assessed before and after propensity-score matching(PSM). Finally, 50 patients were matched. RESULTS: Before matching, patients in the DLI group had poorer 5-year distant relapse-free survival (DRFS) (P < 0.001), disease-free survival (DFS) (P < 0.001), and overall survival (OS) (P = 0.022) than those in the non-DLI group, with the exception of local recurrence-free survival (LRFS) (P = 0.114). After PSM, the 5-year DRFS, DFS, OS, and LRFS were 51.7% vs. 79.8%(P = 0.026), 51.7% vs. 79.8%(P = 0.029), 71.6% vs. 85.4%(P = 0.126), and 85.7% vs. 92.0%(P = 0.253), respectively, between the two groups. DLI was also an independent prognostic factor for poor DRFS with (Hazard ratio [HR] 3.843, P = 0.020) or without matching (HR 2.567, P = 0.001). The DLI group exhibited a higher rate of distant metastasis before (44.4% vs. 19.4%, P < 0.001) and after matching (48.0% vs. 20.0%, P = 0.037) and similar rates of locoregional recurrence before (13.3% vs.7.9%, P = 0.729) and after matching (16.0% vs.12.0%, P = 1.000). CONCLUSIONS: DLI may portend worse DRFS and distant metastasis in LALRC patients with anal sphincter involvement, and this may be an important variable to guide clinicians.

Forty-Year Experience Alleviating Postoperative Hirschsprung-Associated Enterocolitis by Complete Full-Thickness Posterior Rectal Cuff Excision. The Anorectal Line Eliminates Problematic Anastomoses.

Introduction: A modified pull-through (PT) distinguished by complete full-thickness removal of the posterior rectal cuff, initially developed as an open procedure in 1980, has been performed with laparoscopic assistance since 1997. Postoperative bowel dysfunction improved when the anatomic landmark for PT surgery was revised from the dentate line (DL) to the anorectal (or Herrmann's) line (ARL) in 2007. A 40-year (1980-2019) review of 153 consecutive rectal/rectosigmoid type Hirschsprung's disease (HD) patients is presented. Methods: Data for postoperative bowel dysfunction and Hirschsprung-associated enterocolitis (HAEC) classified according to the American Pediatric Surgical Association (APSA) scale were obtained retrospectively. Results: PT was open (n = 43) and laparoscopic (n = 110). Dissection was DL (n = 57) and ARL (n = 96). Over 40 years, 5/153 patients (3.3%) had postoperative obstructive symptoms (POS), and 10/153 patients (6.5%) had 13 episodes of postoperative HAEC; APSA grades were: I (n = 4); II (n = 8); and III: (n = 1) presenting with explosive diarrhea (10/13; 76.9%), fever (10/13; 76.9%), abdominal distension (9/13; 69.2%), or bloody stools/shock (1/13 with grade III; 7.7%). The grade III case had histologically-proven transitional zone PT. Postoperative HAEC developed in 3/5 (60.0%) POS+ patients and 7/148 (4.7%) POS- patients (P = .002). Symptom duration and treatment were not correlated with APSA grades. Conclusions: Complete full-thickness posterior rectal cuff excision and using the ARL reduced postoperative HAEC significantly in this series. Despite being anatomically distinct, the DL is inadequate as a precise landmark for PT surgery because it lacks functional relevance. The APSA scale could benefit from timely review to improve its clinical and prognostic value.

A technique to reconstruct the anal sphincters following iatrogenic stretching related to a pull-through for Hirschsprung disease.

Soiling and fecal incontinence are troubling complications which can occur after a pull-through for Hirschsprung disease. They can usually be improved with proper medical management, but in some cases are the result of an anatomic defect related to overstretching of the sphincters and/or damage of the anal canal. For such patients the treatment of this true fecal incontinence is limited to a structured bowel management program with ante- or retrograde enemas to achieve social continence. Herein we report two such patients with overstretched sphincters and loss of the dentate line after an initial pull-through and describe a sphincter tightening technique to improve bowel control.

Rectal neoplasia extending to the dentate line: clinical outcomes of endoscopic submucosal dissection.

BACKGROUND: The European Society of Gastrointestinal Endoscopy (ESGE) and the Japan Gastroenterological Endoscopy Society (JGES) give no specific recommendations on the best treatment for colorectal neoplasia involving the dental line (DLCN). OBJECTIVE: Aim of this study was to analyse efficacy and safety of Endoscopic Submucosal Dissection in the treatment of colorectal neoplasia involving the dentate line (DLCN) compared to non-DLCN. DESIGN: Retrospective study. PATIENTS: We retrospectively evaluated all consecutive patients undergoing ESD for rectal neoplasia at two endoscopical tertiary referral centers (Italy and Japan) from January 2008 to December 2019. MAIN OUTCOME MEASURES: Anthropometric, clinical, procedural, and follow-up data was collected, analysed, and compared between patients with DLCN and patients with non-DLCN. RESULTS: Overall, 314 patients were enrolled (163 female, 51.9%). Mean age was 68 years (range, 32-92 years). En-bloc resection was achieved in 311/314 (99%) patients. Lesion size was higher in DLCN group than in the non-DLCN group (46.1 vs 38.9 mm; p = .03). Submucosal invasion rate was also higher in the DLCN group (29.6 vs 18.4%, p = .04). Procedure time was significantly longer in the DLCN group, (89.6 vs. 73.1 min; p = .002). Hospitalization length following ESD was similar in both groups. LIMITATIONS: Retrospective study design. CONCLUSIONS: ESD seems to be safe and effective in the treatment of colorectal neoplasia involving the dentate line and can be considered the best therapeutic strategy.

Accuracy of magnetic resonance imaging in predicting dentate line invasion in low rectal cancer.

PURPOSE: To retrospectively assess the accuracy of magnetic resonance imaging (MRI) in predicting dentate line invasion in low rectal cancer. MATERIALS AND METHODS: Eighty-one patients with primary rectal cancer were assessed by dynamic contrast-enhanced MRI. The location of the dentate line was assessed on MRI in 27 patients with upper-mid rectal cancer. Two observers independently evaluated the distance between the distal tumor edge and the MRI-defined dentate line in 54 patients with low rectal cancer, and the imaging and histological findings were compared. RESULTS: The MRI-defined dentate line was 24.0 ± 3.8 mm above the anal verge in patients with upper-mid rectal cancer. The dentate line invasion status agreed with the histological findings in 49/54 (91%) patients (κ = 0.72 [95% CI 0.50-0.95]) for observer 1, and in 51/54 (94%) patients (κ = 0.83 [0.65-1.00]) for observer 2 in patients with low rectal cancer. Interobserver agreement was good (κ = 0.83 [0.65-1.00]). The MRI-derived distance between the distal tumor edge and the dentate line had significant correlation with the histological distance (r = 0.86 for reader 1 and 0.75 for observer 2). CONCLUSION: MRI demonstrates high accuracy in predicting dentate line invasion in low rectal cancer.

Clinical outcomes of endoscopic submucosal dissection for laterally spreading tumors involving the dentate line.

OBJECTIVE: Endoscopic submucosal dissection (ESD) for laterally spreading tumors (LST) involving the dentate line (LST-DL) is challenging because of the specific anatomical features of the anorectum. This study aimed to evaluate the efficacy and safety of ESD for LST-DL. METHODS: Consecutive patients with LST-DL who had undergone ESD at our hospital between January 2010 and December 2015 were retrospectively enrolled in this study. Rates of en bloc resection, R0 resection, and complications, pathological characteristics, and tumor recurrence were analyzed and compared with those of LST in the rectum not involving the dentate line (LST-NDL). RESULTS: Altogether 49 patients with LST-DL (median age 63 years; 39 women; median lesion size 57 mm; median follow-up period of 24 months) and 96 patients with LST-NDL (median age 67 years; 31 women; median lesion size 47 mm; median follow-up period of 31 months) were enrolled. En bloc resection (93.9% [46/49] vs 94.8% [91/96]) and en bloc R0 resection rates (83.7% [41/49] vs 88.5% [85/96]), respectively, for LST-DL and LST-NDL, with no significant differences. However, ESD for LST-DL had a longer procedure time (77 min vs 54 min, P = 0.02), a greater postprocedural perianal pain rate (28.6% vs 0%, P < 0.001), and more anal strictures (4.1% vs 0%, P = 0.04). The complication rates of perforation, bleeding and fever, recurrence rate, and pathological characteristics did not differ between the two groups. CONCLUSIONS: ESD is a safe and effective therapeutic modality for LST-DL. However, this procedure should be performed by experienced endoscopists and the difficulty needs to be fully considered.

Minimally Invasive Neonatal Surgery: Hirschsprung Disease.

Transanal pull-through (TAPT) is the procedure of choice for treating Hirschsprung disease and should be performed with laparoscopic assistance using the anorectal line (ARL) to ensure optimum postoperative bowel function (POBF). The dentate line (DL) has traditionally been used as the landmark for commencing dissection during TAPT, but we prefer the ARL because the DL is too subjective and can be associated with risk for injury to delicate sensory innervation required for normal defecation in the anal transition zone. An intact anal transition zone and total excision of the posterior rectal cuff are crucial for normal defecation. Objective assessment of POBF is essential for thorough follow-up and early detection of potential late complications that may arise.

The efficacy of endoscopic submucosal dissection for colorectal tumors extending to the dentate line.

PURPOSE: Although endoscopic submucosal dissection (ESD) is becoming the mainstay of the treatment strategies, rather than surgical treatment, for colorectal tumors extending to the dentate line, ESD is technically more difficult. This study was aimed at assessing the usefulness of ESD for the treatment of colorectal tumors extending to the dentate line. METHODS: This study included 531 patients with colorectal tumors who underwent colorectal ESD between 2008 and 2015. They were divided into three groups: rectal tumors extending to the dentate line (anorectal group), those not extending to the dentate line (proximal rectal group), and colonic tumors (colonic group), and a retrospective comparative analysis was carried out. RESULTS: Of the total patients, 18 (3.4%) had lesions extending to the dentate line area. The procedure times were 103.4 ± 84.0, 80.4 ± 64.3, and 71.8 ± 52.3 min, respectively (P = 0.0318). All the patients in the anorectal group were operated by operators who had performed at least 20 colorectal ESDs (P < 0.0001). No significant difference among the three groups was found in the en bloc resection rate, complete resection rate, or curative resection rate. Although no significant difference in the incidence of perforation was observed among the three groups, intraoperative bleeding was observed in 61% of the patients in the anorectal group (P < 0.0001). CONCLUSIONS: ESD is an effective treatment strategy for colorectal tumors extending to the dentate line. However, it seems that anorectal ESD, which is technically more difficult than colorectal ESD, should be performed by operators with ample experience in performing ESD.

Endoscopic submucosal dissection for anorectal tumor with hemorrhoids close to the dentate line: a multicenter study of Hiroshima GI Endoscopy Study Group.

BACKGROUND: The lower rectum close to the dentate line has distinct characteristics, making endoscopic submucosal dissection (ESD) of tumors challenging. We assessed clinical outcomes of ESD for such patients with hemorrhoids. METHODS: Sixty-four patients (mean age, 68 years) underwent ESD for anorectal tumors close to the dentate line. We divided patients into those with (Group A, 45 patients) and without hemorrhoids (Group B, 19 patients). We examined en bloc and histological en bloc resection rates, procedure time, complication rates, and postoperative prognosis after ESD. RESULTS: The mean tumor size was 43 mm. Histologic diagnoses were adenoma (42 %, 27/64), carcinoma in situ (44 %, 28/64), and T1 carcinoma (14 %, 9/64). There was no significant difference in en bloc resection (93 %, 42/45 vs. 95 %, 18/19) or postoperative bleeding rates (16 %, 7/45 vs. 11 %, 2/19) between Groups A and B, respectively. The mean procedural durations were 120 and 124 min, respectively, in Groups A and B. No perforations occurred. There was no significant difference in postoperative anal pain rate between Groups A (18 %, 8/45) and B (16 %, 3/19), and it resolved within a few days in all cases. There was one case of stricture in Group B. Two patients with T1 carcinoma underwent additional surgery, one underwent chemotherapy, and five had no additional treatment. No recurrence occurred during the follow-up period of 38 months. CONCLUSIONS: ESD is safe and effective for anorectal tumors close to the dentate line in patients with hemorrhoids.

Removal of Anorectal Cancer by Endoscopic Submucosal Dissection / 대한내과학회지

Anorectal cancer is traditionally treated via abdominoperineal resection and/or chemoradiation. Currently, endoscopic submucosal dissection (ESD) is widely used to treat early gastrointestinal epithelial neoplasias. However, the use of ESD to treat lesions of the anal canal raises concerns that do not arise when treating lesions of the stomach and colorectum. Therefore, particular care is needed when treating lesions in the anal area. We recently treated a 75-year-old woman who was scheduled for surgical resection to treat anorectal cancer. The lesion was successfully removed using ESD. This is the first report of the use of ESD to treat anorectal cancer in Korea. Here, we present our case report and review the relevant literature.

Rectal mucosal dissection commencing directly on the anorectal line versus commencing above the dentate line in laparoscopy-assisted transanal pull-through for Hirschsprung's disease: Prospective medium-term follow-up.

BACKGROUND: In 2007, we began using the anorectal line (ARL) as the landmark for commencing rectal mucosal dissection (RMD) instead of the dentate line (DL) during laparoscopy-assisted transanal pull-through (L-TAPT) for Hirschsprung's disease (HD). We conducted a medium-term prospective comparison of postoperative fecal continence (POFC) between DL and ARL cases to follow our short-term study. METHODS: POFC is assessed by scoring frequency of motions, severity of staining, severity of perianal erosions, anal shape, requirement for medications, sensation of rectal fullness, and ability to distinguish flatus from stool on a scale of 0 to 2 (maximum: 14). RESULTS: Patient demographics were similar for ARL (2007-2014: n=33) and DL (1997-2006: n=41). There were no intraoperative complications and 2 cases of postoperative colitis in both ARL (6.1%) and DL (4.9%). Mean annual medium-term POFC scores for the 4-7 term of this study were consistently better in ARL: 9.7±1.4*, 10.1±1.6*, 10.6±1.6, and 11.3±1.4* in ARL and 8.6±1.5, 9.1±1.6, 9.8±1.9, 10.0±1.6 in DL (*: p<0.05). CONCLUSIONS: Medium-term POFC is better when the ARL is used as the landmark for RMD during L-TAPT for HD.

Transanal Suture Rectopexy for Haemorrhoids: Chivate's Painless Cure for Piles.

The aim of the study was to evaluate Chivate's new procedure of transanal suture rectopexy for haemorroids for pain, bleeding, hospital stay, recurrence and complications. During the period between January 2006 and December 2008, the procedure was used for 166 cases symptomatic of grade II, III and IV haemorrhoids, at six different institutes by five different colorectal surgeons. In the series, 92 cases were males and 74 cases were females; average age was 49.5 years; youngest patient was 23 years of age and eldest was of 82 years of age. According to the gradation, II-52 cases, III-86 cases and IV-28 cases were enrolled for the procedure. The piles mass was reduced by head low and manually. The mucosa and submucosa were transfixed to muscle of the rectum by 0.5-1.0 cm long stitches. Similar stitching was continued all along the complete circumference of the rectum, 2 and 4 cm distal to the dentate line. In all cases, antibiotics and anti-inflammatory medicines were prescribed for 5 days. No pain was noticed in 162 cases; in 4 cases a pain dull in nature was described by the patients. All the 166 cases were discharged after 24 h. Intraoperative bleeding from the suture line was observed in 15 cases, which required temporary compression. On proctoscopy, in 3 cases intra-anal grade I, protrusion of piles cushion without bleeding was noticed. No incontinence, no recurrent bleeding, no frequency of stool, or no tenusmus was observed. In 2 cases, 6 months after operation, residual external piles were observed, which required excision. The procedure requires no special costly instruments or any disposables. Patients require short stay for 24 h. The procedure is a painless cure for haemorrhoids.

Stapled haemorrhoidectomy in the choice of anastomosis site in patients with severe circumferential prolapsed haemorrhoids / 国际外科学杂志

Objective To explore the correlation of the distance between anastomosis and dentate line in patients with severe circumferential prolapsed haemorrhoids treated by stapled haemorrhoidectomy with the patients' postoperative clinical manufestival score, and assess its value in the choice of anastomosis site in stapled haemorrhoidectomy. Methods One hundred and six patients with severe circumferential prolapsed haemorrhoids was treated by stapled haemorrhoidectomy. The distance between anastomosis and dentate line was documented during the operation, effect of the treatment and complications were also documented postoperatively. All above-mentioned data were analysed statisticaly by one-way ANOVA and ridit test.Results Four groups were established in 106 patients according to the distance between anastomosis and dentate line. Patients with distance less than 1.0cm were defined as group A, between 1.0 cm and 1.5 cm as group B, between 1.5 cm and 2.0 cm as group C, more than 2.0 cm as group D. Concerning the postoperative incontinence score, satisfaction index and complications such as haemorrhage,ederma of anal everage,residal skin-tags, there was no significant difference between all groups. But there was significant difference between four groups in score of pain. Conclusions Patients with severe circumferential prolapsed haemorrhoids treated by Stapled haemorrhoidectomy tend to have good clinical outcome. The appropriate distance between anastomosis and dentate line should be chosed by the status of prolapsed haemorrhoids.

Anal canal dentate line: the important anatomic maker in prostate apical biopsy pain control / 中华泌尿外科杂志

Objective To explore the causes of more frequently happened painful prostate biopsy at the prostatic apex rather than at other areas of the gland and develop maneuvers to avoid this painful apical prostate biopsy. Methods The prostate apical biopsy needle ptmeture sites in the rectum were recorded and accessed. Two maneuvers were developed to avoid the pain. There were 3 groups in this clinical trail. Ten patients in the control group were performed the apical biopsies routinely without any maneuver. Ten patients in the anal canal local anesthesia group were exposed to local anesthesia with 1% lidocaine injected into anal canal ventral hemieyele prior inserting the ultrasound probe, then the ultrasound guided apical biopsies were performed. Fifteen patients were assigned to the rectal pain sensation test group. In this group, the dentate line ot anal canal was detected before the biopsy needle was aimed at apex and touched the rectal mucosa lightly. There would be no painful sensation if the puncture was above the dentate line and the painful sensation would be sharp if the puncture was below the dentate line. Then the apical biopsy was performed above the dentate line. All patients were offered apical prostate biopsies and then other areas of prostate would be biopsied. Patients were asked to score the visual analog scale (VAS) immediately after the prostate apical biopsy. Results The VAS score of apical biopsy in 3 groups were 4. 46±1.24 in control group, 1.84± 0. 75 in anal canal local anesthesia group, 1.98±0. 67 in rectal pain sensation test group (P<0.05), respectively. So, patient would have painful sensation if the prostate apical biopsy puncture site was below the rectal dentate line. The VAS score of patient was 5.24±0.83 at the time of applying the anal canal local anes thesia. There was no significant difference comparing to the control group (P>0. 05). In this study, there was 1 patient with crissum pain after biopsy in control group and 1 patient in anal canal local anesthesia group, separately. 1 patient suffered high fever (38.4 ℃) in rectal pain sensation test group. Conclusions The prostate biopsy puncture site below or above the dentate line decides if it will be a painful prostate apical biopsy or not. We can significantly decrease the painful sensation by aim the puncture sites above the anal canal dentate line. The application of anal canal anesthesia can decrease pain score caused by prostate biopsy. However, this application itself can provoke obvious pain. So the application of anal canal anesthesia has limited role in patient's pain control during the prostate biopsy.

AN INITIAL STUDY ON ESOPHAEEAL LENGTH OF THE CHINES PEOPLE BY ENDOSCOPIC MEASUREMENT / 西安交通大学学报(医学版)

The lenght from incisor to dentate line of the cardia was measured by watching esophageal cavity by means of endoscope Studying a total of 644 cases (380 males and 264 females) we found ①The average length from incisor to dentate line of the cardia was 41.084?2.032 cm for male, 38.24?2.08 cm for female and the difference between male and female was statistically significant (P