Clinicopathological features and prognosis of synchronous and metachronous colorectal cancer: a retrospective cohort study.

BACKGROUND: To investigate the clinicopathological features and prognosis of synchronous and metachronous multiple primary colorectal cancer. MATERIALS AND METHODS: Patients who underwent operation for synchronous and metachronous colorectal cancer at the colorectal surgery department of Shanghai Changhai Hospital between January 2000 and December 2021 were included. Perioperative indicators were comprehensively compared and included in the survival analyses. RESULTS: In total, 563 patients with synchronous ( n =372) and metachronous ( n =191) colorectal cancer were included. Patients with synchronous colorectal cancer were more likely to have a long onset time, positive carcinoembryonic antigen, advanced TNM stage, large tumor, perineural invasion, p53 high expression, and mismatch repair proficient. Compared with metachronous colorectal cancer, patients with synchronous colorectal cancer showed worse 5-year overall survival (68.6±3.0% vs 81.9±3.5%, P =0.018) and 5-year disease-free survival (61.2±3.1% vs 71.0±3.9%, P =0.022). In the subgroup analysis, segmental resection was an independent risk factor for the long-term outcomes of bilateral synchronous colorectal cancer. CONCLUSIONS: Clinicopathological and molecular features were different between synchronous and metachronous colorectal cancer. Patients with synchronous colorectal cancer showed a worse prognosis than those with metachronous colorectal cancer. Bilateral synchronous colorectal cancer requires extended resection to achieve improved long-term outcomes.

Comparison of functional and oncological outcome of conformal sphincter preservation operation, low anterior resection, and abdominoperineal resection in very low rectal cancer: a retrospective comparative cohort study with propensity score matching.

PURPOSE: Conformal sphincter preservation operation (CSPO) procedure is a sphincter preservation procedure for preserving the anal canal function for very low rectal cancers. This study investigated the functional and oncological outcome of conformal sphincter preservation operation by comparing with low anterior resection (LAR) and abdominoperineal resection (APR). METHODS: This is a retrospective comparative study. Patients who received conformal sphincter preservation operation (n = 52), low anterior resection (n = 54), or abdominoperineal resection (n = 69) were included between 2011 and 2016 in a tertiary referral hospital. Propensity score matching was applied to adjust the baseline characteristics which may influence the choice of the surgical procedure. RESULTS: Twenty-one pairs of conformal sphincter preservation operation vs. low anterior resection and 29 pairs of conformal sphincter preservation operation vs. abdominoperineal resection were selected. The first group had a higher tumor location than the second group. Compared with the low anterior resection group, the conformal sphincter preservation operation group had shorter distal resection margins; however, no significant differences were identified in daily stool frequency, Wexner incontinence score, local recurrence, distant metastasis, overall survival, and disease-free survival between both groups. Compared with the abdominoperineal resection group, the conformal sphincter preservation operation group had shorter operative time and shorter postoperative hospital stay. No significant differences were identified in local recurrence, distant metastasis, overall survival, and disease-free survival. CONCLUSION: Conformal sphincter preservation operation is oncologically safe compared to APR and LAR, and has similar functional findings to LAR. Studies comparing CSPO with intersphincteric resection should be performed.

Predictive value of modified MRI-based split scar sign (mrSSS) score for pathological complete response after neoadjuvant chemoradiotherapy for patients with rectal cancer.

PURPOSE: To measure the diagnostic performance of modified MRI-based split scar sign (mrSSS) score for the prediction of pathological complete response (pCR) after neoadjuvant chemoradiotherapy (nCRT) for patients with rectal cancer. METHODS: The modified MRI-based split scar sign (mrSSS) score, which consists of T2-weighted images (T2WI)-based score and diffusion-weighted images (DWI)-based score. The sensitivity, specificity, and accuracy of modified mrSSS score, endoscopic gross type, and MRI-based tumor regression grading (mrTRG) score, in the prediction of pCR, were compared. The prognostic value of the modified mrSSS score was also studied. RESULTS: A total of 189 patients were included in the study. The Kendall's coefficient of interobserver concordance of modified mrSSS score, T2WI -based score, and DWI-based score were 0.899, 0.890, and 0.789 respectively. And the maximum and minimum k value of the modified mrSSS score was 0.797 (0.742-0.853) and 0.562 (0.490-0.634). The sensitivity, specificity, and accuracy of prediction of pCR were 0.66, 0.97, and 0.90 for modified mrSSS score; 0.37, 0.89, and 0.78 for endoscopic gross type (scar); and 0.24, 0.92, and 0.77 for mrTRG score (mrTRG = 1). The modified mrSSS score had significantly higher sensitivity than the endoscopic gross type and the mrTRG score in predicting pCR. Patients with lower modified mrSSS scores had significantly longer disease-free survival (P < 0.05). CONCLUSION: The modified mrSSS score showed satisfactory interobserver agreement and higher sensitivity in predicting pCR after nCRT in patients with rectal cancer. The modified mrSSS score is also a predictor of disease-free survival.

Trends of sphincter-preserving surgeries for low lying rectal cancer: A 20-year experience in China.

Background: Over the last 2 decades, patients with low rectal cancer have had better outcomes from improvements in surgical techniques in sphincter preservation. We aimed to quantify the trends in sphincter-preserving surgeries for low rectal cancer over 20 years in a top tertiary hospital in China. Methods: Between 1999 and 2021, a cohort of patients with primary malignant rectal tumor ≤5cm from the anal verge and who received elective surgeries at Changhai Hospital, Shanghai, China, was identified. Data were extracted from electronic medical records. A Joinpoint Regression Model was used to analyze trends in surgical procedures by average annual percentage change (AAPC). Adjusted Cox proportional hazards regression model was used to assess overall survival. Results: Among a total of 4,172 patients during the study period, 3,111 (74.6%) underwent a sphincter-preserving surgery and 1,061 (25.4%) received APR. Sphincter-preserving surgery increased 3.6% per year (95%CI, 2.3-4.9). Low anterior resection was the most performed procedure (86.3%) and maintained a steady trend, while intersphincteric resection increased 49.4% annually (95%CI, 19.5-86.7) after initiation. Laparoscopic techniques increased 15.1% per year (95%CI, 8.4-43.4) after initiation. Sphincter-preserving surgery increased annually for tumors ≤2cm, 2-≤3cm and 3-≤4cm from the anal verge (AAPC 7.1, 4.5-9.8; 4.7, 3.1-6.3; 2.7, 1.7-3.6, respectively). Furthermore, patients with sphincter-preserving surgery had a better overall survival than abdominoperineal resection (APR) patients (adjusted HR 0.78, 95% CI, 0.65-0.93, p=.01). Conclusions: Utilization of sphincter-preserving surgeries increased significantly over the last 20 years. Patients with low rectal cancer who underwent sphincter preservation had better survival than similar patients who underwent APR.

The Classification and Surgical Treatments in Adult Hirschsprung's Disease: A Retrospective Study.

Purpose: To explore the treatments and short-term effects of different types of adult Hirschsprung's disease. Methods: 89 patients treated in Shanghai Changhai Hospital were retrospectively analyzed. According to the patient's medical history, clinical manifestations, auxiliary examination and postoperative pathological results, the patients were divided into adult congenital megacolon, adult idiopathic megacolon, ganglion cell deficiency (types I and II), toxic megacolon and iatrogenic megacolon, The Treatment methods and short-term prognosis of patients in each group were summarized. Results: 41 cases of Hirschsprung's disease in adults and low anterior resection or pull-out low anterior resection was performed, and 35 patients with idiopathic Megacolon were treated with one-stage subtotal colon resection under the condition of adequate preoperative preparation. Some patients admitted for emergency intestinal obstruction received conservative treatment first or underwent elective surgery after colonoscopic decompression was improved; two patients with ganglion cell deficiency subtotal colectomy were performed to remove the dilated proximal bowel segment and the narrow distal bowel segment; three patients with toxic Hirschsprung's disease underwent colostomy in mild cases, while subtotal colorectal resection was required in severe cases; Iatrogenic megacolon was diagnosed in eight cases and the optimum operation should be selected according to the specific conditions of patients. Conclusion: Adult Hirschsprung's diseases were divided into adult congenital hirschsprung's disease, idiopathic Hirschsprung's disease, ganglion cell deficiency, toxic hirschsprung's disease, and iatrogenic Hirschsprung's disease. Different types of surgical treatments for Hirschsprung's disease in adults should be selected according to the specific diagnosis. All patients with adult Hirschsprung's diseases have good short-term outcomes after surgical treatment.

A novel 9-gene signature for the prediction of postoperative recurrence in stage II/III colorectal cancer.

Background: Individualized recurrence risk prediction in patients with stage II/III colorectal cancer (CRC) is crucial for making postoperative treatment decisions. However, there is still a lack of effective approaches for identifying patients with stage II and III CRC at a high risk of recurrence. In this study, we aimed to establish a credible gene model for improving the risk assessment of patients with stage II/III CRC. Methods: Recurrence-free survival (RFS)-related genes were screened using Univariate Cox regression analysis in GSE17538, GSE39582, and GSE161158 cohorts. Common prognostic genes were identified by Venn diagram and subsequently subjected to least absolute shrinkage and selection operator (LASSO) regression analysis and multivariate Cox regression analysis for signature construction. Kaplan-Meier (K-M), calibration, and receiver operating characteristic (ROC) curves were used to assess the predictive accuracy and superiority of our risk model. Single-sample gene set enrichment analysis (ssGSEA) was employed to investigate the relationship between the infiltrative abundances of immune cells and risk scores. Genes significantly associated with the risk scores were identified to explore the biological implications of the 9-gene signature. Results: Survival analysis identified 347 RFS-related genes. Using these genes, a 9-gene signature was constructed, which was composed of MRPL41, FGD3, RBM38, SPINK1, DKK1, GAL3ST4, INHBB, CTB-113P19.1, and FAM214B. K-M curves verified the survival differences between the low- and high-risk groups classified by the 9-gene signature. The area under the curve (AUC) values of this signature were close to or no less than the previously reported prognostic signatures and clinical factors, suggesting that this model could provide improved RFS prediction. The ssGSEA algorithm estimated that eight immune cells, including regulatory T cells, were aberrantly infiltrated in the high-risk group. Furthermore, the signature was associated with multiple oncogenic pathways, including cell adhesion and angiogenesis. Conclusion: A novel RFS prediction model for patients with stage II/III CRC was constructed using multicohort validation. The proposed signature may help clinicians better manage patients with stage II/III CRC.

Rectal cancer patients with downstaging after neoadjuvant chemoradiotherapy and radical resection do not benefit from adjuvant chemotherapy.

BACKGROUND: Whether adjuvant chemotherapy is beneficial for rectal cancer patients who respond well to neoadjuvant chemoradiotherapy (NCRT) and undergo radical resection is controversial. This study aimed to assess the effect of adjuvant chemotherapy on the oncological outcomes of ypT0-2N0 rectal cancer patients after NCRT and radical resection, and identify the prognostic factors. METHODS: The clinical and pathological data of rectal cancer patients with ypT0-2N0 who underwent NCRT and radical resection between January, 2010 and June, 2018 were collected and retrospectively analyzed. The oncological outcomes of the chemotherapy (chemo) group and the non-chemotherapy (non-chemo) group were compared. Multivariate analysis, using a Cox proportional hazard model, was performed to identify independent predictors of oncological outcome. RESULTS: Of the 121 rectal cancer patients enrolled, 90 patients received postoperative adjuvant chemotherapy with no fewer than 3 cycles (the chemo group), and the other 31 patients with fewer than 3 cycles (the non-chemo group). There was no significant difference in the 5-year disease-free survival (DFS) or overall survival (OS) rates between the two groups (DFS: 79.1% vs. 82.9%, P=0.442; OS: 87.5% vs. 78.2%, P=0.667). cT4 is an independent risk factor for OS (HR =4.227, 95% CI: 1.128-15.838, P=0.02) and DFS (HR =4.878, 95% CI: 1.752-13.578). Preoperative consolidation chemotherapy with Capeox or FOLFOX after NCRT significantly improved the DFS rate (HR =0.212, 95% CI: 0.058-0.776, P=0.019). CONCLUSIONS: Rectal cancer patients with ypT0-2N0 who underwent NCRT and radical resection did not benefit significantly from postoperative adjuvant chemotherapy. For these patients, cT4 was an independent risk factor for OS and DFS. Preoperative consolidation chemotherapy with Capeox or FOLFOX after NCRT can significantly improve DFS.

[A single center retrospective study on surgical efficacy of T3NxM0 middle-low rectal cancer without neoadjuvant therapy].

OBJECTIVE: To investigate the surgical efficacy and prognostic factors of T3NxM0 middle-low rectal cancer without neoadjuvant therapy. METHODS: Clinical data of patients with middle-low rectal cancer undergoing TME surgery with T3NxM0 confirmed by postoperative pathology at Colorectal Surgery Department of Changhai Hospital from January 2008 to December 2010 were analyzed retrospectively. INCLUSION CRITERIA: (1)no preoperative neoadjuvant chemoradiotherapy (nCRT); (2) complete preoperative evaluation, including medical history, preoperative colonoscopy or digital examination, blood tumor marker examination, and imaging examination; (3) distance between tumor lower margin and anal verge was ≤ 10 cm; (4) negative circumferential resection margin (CRM-). Finally, a total of 331 patients were included in this study. According to the number of metastatic lymph node confirmed by postoperative pathology, the patients were divided into N0 group without regional lymph node metastasis (190 cases) and N+ group with regional lymph node metastasis (141 cases). The perioperative conditions, local recurrence, distant metastasis and prognostic factors were analyzed. RESULTS: Compared to N0 group in the perioperative data, N+ group had higher ratio of tumor deposit [29.8%(42/141) vs. 0, χ²=64.821, P<0.001] and vascular invasion [7.1%(10/141) vs. 0.5%(1/190),χ²=10.860, P<0.001]. There were no significant differences in tumor diameter, number of lymph nodes detected, positive nerve invasion, degree of tumor differentiation, morbidity of postoperative complication and postoperative adjuvant chemotherapy rate between the two groups (all P>0.05). The median follow-up period was 73.4 months. The merged 5-year local recurrence rate was 2.7%(9/331), 5-year distant metastasis rate was 23.3% (77/331), 5-year disease-free survival (DFS) rate was 73.4%, and 5-year overall survival (OS) rate was 77.2%. Multivariate analysis showed that lymph node metastasis (HR=3.120, 95%CI: 1.918 to 5.075, P<0.001), nerve invasion (HR=0.345, 95%CI: 0.156 to 0.760, P=0.008) and vascular invasion (HR=0.428, 95%CI: 0.189 to 0.972, P=0.043) were independent risk factors for DFS in patients with T3NxM0 rectal cancer after operation. Preoperative carcinoembryonic antigen level (HR=1.858, 95%CI:1.121 to 3.079, P=0.016), lymph node metastasis (HR=3.320, 95%CI: 1.985 to 5.553, P<0.001) and nerve invasion (HR=0.339, 95%CI: 0.156 to 0.738, P=0.006) were independent risk factors for OS in patients with T3NxM0 rectal cancer after operation. CONCLUSIONS: Optimal local control rate of middle-low rectal cancer patients with T3NxM0 and CRM- can be achieved by standard TME surgery alone. For patients with preoperative elevated blood carcinoembryonic antigen level, regional lymph node metastasis, or neurovascular invasion confirmed by pathology after surgery, adjuvant chemoradiotherapy should be actively applied after surgery to improve prognosis.

[Study on the relationship between tumor regression grade and lymph node regression grade].

OBJECTIVE: To investigate the relationship between tumor regression grade (TRG) and lymph node regression grade (LRG) after neoadjuvant chemoradiotherapy (CRT) for rectal cancer and its clinical implication. METHODS: Clinicopathological data of 176 rectal cancer patients undergoing radical excision after neoadjuvant CRT from January 2005 to December 2013 in our department were retrospectively analyzed. INCLUSION CRITERIA: (1) Radiology indicated locally advanced low rectal cancer and patients had strong desire to preserve the sphincter before neoadjuvant CRT; (2) there was no definite metastatic lesion before neoadjuvant CRT; (3) patients received whole course of neoadjuvant CRT (regular radiotherapy plus synchronous fluorouracil-like drugs chemotherapy); (4) patients underwent radical operation after neoadjuvant CRT. Patients with short-course CRT and emergency surgery were excluded. TRG and LRG of postoperative specimens (including tumor and lymph nodes) were carried out based on the percentage of the fibrosis and the cancer residue. No cancer residue was defined as TRG1 and LRG1; rare cancer cell residue as TRG2 and LRG2; fibrosis growth over residual cancer as TRG3 and LRG3; residual cancer growth over fibrosis as TRG4 and LRG4; absence of regressive changes as TRG5 and LRG5; and normal lymph nodes as LRG0. Spearman correlation test was used to assess the correlation between TRG and LRG. RESULTS: Of 176 patients, 111 were men and 65 were women. The mean age was (53.9±13.0) years. The number of patients with stage I(, II(, and III( before operation was 10, 49 and 62 while other 55 patients were unknown. Transabdominal low anterior resection (LAR) was performed in 118 cases and abdominal-perineal resection(APR) in 47 cases following the principle of total mesorectal excision (TME). Postoperative pathology of specimens revealed that the number of patients from TRG1 to TRG5 was 19 (10.8%), 25 (14.2%), 66 (37.5%), 47 (26.7%), 19 (10.8%), and from LRG0 to LRG5 was 35 (19.9%), 68 (38.6%), 10 (5.7%), 14 (8.0%), 15(8.5%), 34 (19.3%), respectively. TRG was correlated to LRG (P=0.005) while the Spearman correlation coefficient was only 0.24. The analysis of subgroup without LRG1 also showed that TRG was correlated to LRG(P=0.0005) and the Spearman correlation coefficient was 0.40. CONCLUSIONS: TRG can not represent LRG. Therefore, both TRG and LRG should be assessed when evaluating the response of rectal cancer to neoadjuvant CRT.

Multicenter analysis of risk factors for anastomotic leakage after middle and low rectal cancer resection without diverting stoma: a retrospective study of 319 consecutive patients.

PURPOSE: The purpose of this study was to evaluate the risk factors for anastomotic leakage (AL) after anterior resection for middle and low rectal cancer in order to help surgeons to decide which patients could benefit from a diverting stoma. METHODS: Data on 319 patients having a middle and low rectal cancer resection with anastomosis between May 2011 and October 2015 from two hospitals were included in the study. The analysis included the following variables: patient-related variables (gender, age, diabetes mellitus, ASA score, preoperative radiochemotherapy, body mass index, blood hemoglobin, and serum albumin level), tumor-related variables (K-ras status, distance of tumor from the anal verge, histopathologic grade, pathological T stage, pathological N stage, pathological M stage, TNM stage, and tumor size), and surgery-related variables (laparoscopic or open surgery, blood loss, and operative time). Univariate and multivariate regression analysis were carried out to identify risk factors for AL. RESULTS: The AL rate was 11.91% (38/319). Male (OR 2.898, 95% CI 1.265-6.637, p = 0.012), diabetes mellitus (OR 2.482, 95% CI 1.004-6.134, p = 0.049), K-ras mutation (OR 2.544, 95% CI 1.210-5.348, p = 0.014), distance of tumor from the anal verge (OR 3.445, 95% CI 1.631-7.279, p = 0.001), and preoperative radiochemotherapy (OR 2.790, 95% CI 1.056-7.372, p = 0.039) were independent risk factors of AL. One (2.63%) in 38 patients with AL presented with no risk factor of AL, 6 (15.8%) in 38 patients with 1 risk factor, 16 (42.1%) in 38 patients with 2 risk factors, 9 (23.7%) in 38 patients with 3 risk factors, and 6 (15.7%) in 38 patients with 4 risk factors. No patient with 5 risk factors in our study. AL rate increased with the elevated number of risk factors clustering in individuals. CONCLUSIONS: K-ras mutation is first reported to be an independent risk factor for AL after sphincter-preserving surgery without diverting stoma. A diverting stoma should be performed in sphincter-preserving surgery for middle and low rectal cancer patients with 2 or more risk factors identified in this analysis.

[Preliminary investigation of intramural lateral spread distance in pull-through conformal resection of low rectal cancer].

OBJECTIVE: To investigate the intramural lateral spread distance in low rectal cancer in order to provide basis for safety lateral resection margin of pull-through conformal resection (PTCR). METHODS: The patients with low rectal cancer who received low anterior resection or abdominal-perineal resection in Changhai Hospital from December 2015 to March 2016 were enrolled and Surgical specimens were collected. After the specimens were fixed in 10% formaldehyde for 24 hours, a piece of tissue that was 1.5 cm in length and 0.5 cm in width from the edge of tumor was cut. The tissue was obtained in the direction of 3, 5, 7 and 9 o'clock clockwise. The distance of intramural lateral spread was measured in the specimens and the risk factors were analyzed. RESULTS: A total of 83 specimens were collected and the overall proportion of intramural lateral spread was 71.1%(59/83). The rate of lateral spread from 3 to 9 o'clock was 34.9%(29/83), 26.5%(22/83), 32.5%(27/83) and 37.3%(31/83) respectively, and the difference was not statistically significant(χ2=2.444 9, P=0.485 3). The median distance of lateral spread in each direction was all 0 mm and the quartile range was 1 mm, 0.5 mm, 0.55 mm and 1 mm respectively. The 5th percentile (P5) of each direction was all 0 mm and the 95th percentile(P95) of each direction was 2.5 mm, 1.6 mm, 2.6 mm, 2.5 mm, respectively and the difference was not statistically significant either(χ2=5.331 0, P=0.148 9). The rate of lateral spread of T1, T2, T3 and T4 was 0/4, 58.3%(14/24), 83.0%(44/53) and 1/2 respectively, and there was significant difference(P=0.005 0). The multivariate analysis indicated that T stage (P=0.002 2, OR=3.741, 95% CI: 1.606-8.716) was the risk factor of intramural lateral spread. CONCLUSIONS: The intramural lateral spread does exist in low rectal cancer and T stage is the risk factor of lateral spread. The lateral resection margin should be 5 mm from the tumor edge at least when PTCR is performed.

[Assessment of the risk factors relating to lymph node metastasis in rectal cancer after neoadjuvant chemoradiotherapy and the clinical significance].

OBJECTIVE: To identify the risk factors associated with lymph node metastasis in rectal cancer after neoadjuvant chemoradiotherapy (CRT). METHODS: From January 2005 to December 2013, the clinical data of 178 patients with advanced rectal cancer undergoing radical excision after neoadjuvant CRT in our department were reviewed retrospectively. A total of 11 clinicopathologic factors relating to lymph node metastasis were studied using univariate and multivariate Logistic regression analyses. RESULTS: There were 74(41.6%) cases with lymph node metastasis, while 104 cases without lymph node metastasis. Univariate analysis showed that age(P=0.000 2), post-CRT CEA level(P=0.011 2), ypT stage(P=0.000 0), pathologic type(P=0.004 0), and tumor regression grade(TRG)(P=0.033 8) were significantly associated with lymph node metastasis. Multivariate analysis showed that age(OR=2.385, 95% CI:1.372 ~ 4.147, P=0.002 1), post-CRT CEA level(OR=2.310, 95% CI:1.005 ~ 5.307, P=0.048 6) and ypT stage(OR=2.592, 95% CI:1.236 ~ 5.432, P=0.011 7) were independent risk factors. However, 15.8% of the patients who achieved TRG1 had lymph node metastasis and TRG failed to independently correlate with lymph node metastasis in rectal cancer after neoadjuvant CRT. CONCLUSIONS: There was a higher ratio of lymph node metastasis in rectal cancer patients who were young, CEA≥5 µg/L or deep invasion after neoadjuvant CRT. Therefore, neoadjuvant CRT should be carefully considered in these patients.

Endoscopic submucosal dissection versus transanal local excision for rectal carcinoid: a comparative study.

AIM: The aim of this study is to compare the short-term clinical outcomes between endoscopic submucosal dissection and transanal local excision for rectal carcinoid tumors. METHODS: Between 2007 and 2012, 31 patients with rectal carcinoid underwent endoscopic submucosal dissection at our hospital. They were compared with a matched cohort of 23 patients who underwent transanal local excision for rectal carcinoid between 2007 and 2012. Short-term clinical outcomes including surgical parameters, postoperative recovery, and oncologic outcomes were compared between the two groups. RESULTS: The mean size of tumors was significantly bigger in the transanal local excision group (0.8 ± 0.2 versus 1.1 ± 0.5 cm; P = 0.018). En bloc resection was achieved for 30 patients (97 %) in the endoscopic submucosal dissection group and all the patients in the transanal local excision group. The operation time was longer in the transanal local excision than that in the endoscopic submucosal dissection group (40.0 ± 22.7 min versus 12.2 ± 5.3 min; P < 0.001). Complications in the transanal local excision group were five cases of acute retention of urine. There was no local recurrence or distant metastasis in either group during the follow-up period. CONCLUSION: For the treatment of rectal carcinoid tumors with diameter <1 cm, endoscopic submucosal dissection has better short-term clinical outcomes than transanal local excision in terms of faster recovery and possibly a lower morbidity rate. Transanal local excision may be the first therapeutic choice of scar-embedded rectal carcinoid tumors.

Influence of neoadjuvant chemoradiotherapy on the anal sphincter: ultrastructural damage may be critical.

BACKGROUND: Neoadjuvant chemoradiotherapy (nCRT) in addition to the curative surgery has been the first of treatment for local advanced rectal cancer because of its benefits in local recurrence and sphincter-saving. However, its side effects on anorectal function have been recognized. The histopathological changes on internal anal sphincter (IAS) have been reported, but ultrastructure changes of external anal sphincter (EAS) are unknown. The aim of this study is to detect the alterations on the gross morphology of IAS and ultrastructure of EAS after nCRT. METHODS: We collected 34 anal canal specimens of patients undergoing abdominoperineal resection (APR) prospectively. The length and thickness of IAS were measured with vernier caliper. The EAS was dissected for observation with transmission electron microscope (TEM). RESULTS: Ten patients received nCRT (nCRT group) before surgery and 24 underwent APR directly (control group). The length and thickness of IAS in nCRT group were 22.68 ± 3.56 and 5.39 ± 0.74 mm, respectively. These parameters were 21.28 ± 3.62 and 5.35 ± 1.12 mm in control group, respectively. There were no significant differences in the length and thickness of IAS between the two groups (P>0.05). In nCRT group, the sarcomere and myofibril were arranged disorderly and parts of them that were filled with collagenous fiber, triads, and mitochondria were destroyed severely and the glycogenosome also distributed disorderly. Such alterations of EAS did not occur in control group. CONCLUSIONS: The nCRT cannot change the gross morphology of IAS, while it induces serious damages to the ultrastructures of EAS which may adversely affect the anorectal function.

[Analysis of risk factors associate with lymph node metastasis of T1 and T2 rectal cancer].

OBJECTIVE: To investigate the risk factors associated with lymph node metastasis of T1 and T2 rectal cancer. METHODS: Clinicopathological data of 576 patients with stage T1 to T2 rectal cancer without serosal invasion confirmed by pathology undergoing curative resection in Changhai Hospital from January 1999 to December 2013 were analyzed retrospectively. The relationship of clinicopathological factors of overall patients and stage T1 patients with lymph node metastasis was analyzed by univariate or multivariate analysis. RESULTS: The lymph node metastasis rate of stage T2 rectal cancer was significantly higher than that of stage T1[22.9% (108/463) vs. 9.7%(11/113), P=0.002], and the difference of stage T2a and T2b was not significant[22.0%(38/173) vs. 23.4% (68/290), P=0.733]. Multivariate analysis showed that poor differentiation(HR=1.54, 95% CI:1.12 to 2.13), abnormal carbohydrate antigen (CA) 199 level (HR=2.05, 95% CI:1.16 to 3.62), ulcerative mass (HR=1.58, 95% CI:1.05 to 2.39) and invasion of muscle (of inner ring muscle HR=3.55, 95% CI:1.79 to 7.02; of outer longitudinal muscle, HR=2.35, 95% CI:1.21 to 4.60) were independent risk factors of lymph node metastasis in patients with stage T1-T2 rectal cancer(all P<0.05). Meanwhile poor differentiation(HR=4.43, 95% CI:1.51 to 13.03), abnormal carcinoembryonic antigen(CEA) level (HR=4.66, 95% CI:1.18 to 20.11) and ulcerative mass (HR=6.23, 95% CI:1.51 to 25.66) were risk factors of lymph node metastasis in patients with stage T1 rectal cancer. CONCLUSION: Poor differentiation, preoperative high CA199, ulcerated tumor, invasion of inner ring muscle or outer longitudinal muscle are risk factors of lymph node metastasis in patients with stage T1-T2 rectal cancer, while the invasion depth of muscularis propria is not risk factor. Besides, poor differentiation, abnormal CEA level, ulcerated tumor are risk factors of lymph node metastasis in stage T1 rectal cancer patients, which can be used as reference for local excision in patients with stage T1 rectal cancer.

Predictive Factors for Surgical Intervention in Patients over the Age of 80 with Adhensive Small-Bowel Obstruction.

Adhensive small-bowel obstruction (SBO) remains a common cause of admission to surgical wards around the world. Given the growing elderly population, the number of elderly patients with adhensive SBO can be expected to increase substantially. Timely and appropriate treatment would improve morbidity and mortality rates in elderly patients with adhensive SBO. However, accurately determining which patients should undergo surgical treatment during the hospitalization remains difficult. The aim of this study was to identify predictive factors for surgical intervention in patients aged over 80 years presenting with SBO due to postoperative adhesions. A clinical and radiological data for the assessment of patients presenting with adhensive SBO were collected. A logistic regression model was applied to identify risk factors that would predict the need of surgical intervention. A total of 21 patients (13 males, 8 females) were treated during a 3.5-year period. The mean age was 85.5 ± 4.7 years, ranging from 80 to 97 years. There is no significant difference in age (group 1 87.6 ± 5.9 years vs. group 2 84.8 ± 4.3 years, p = 0.262) between two groups. Serious coexisting diseases were noted in 13 (61.9 %, 13/21) patients. Primary hypertension, cardiac diseases, and diabetes mellitus were common coexisting conditions. However, there is no significant difference in comorbidities (40 vs. 68.8 %, p = 0.325) between group 1 and group 2. Adhensive SBO was successfully treated with conservative treatment in 16 patients (76.2 %, 16/21, group 2), whereas conservative treatment failed in 5 patients (23.8 %, 5/21, group 1), who subsequently underwent laparotomy. Postoperative complication rate was 14.3 % (wound infection, 1/5) and mortality was 0 % (0/5) in group 1. One patient death was recorded in group 2 (1/16, 6.3 %). The overall mean hospital stay was 10.0 ± 5.9 days (range 3-27 days). Group 1 had a longer hospital stay than group 2. However, the difference did not reach the significant level (12.8 ± 8.2 vs. 9.1 ± 5.9 days, p = 0.274). On univariate analysis, the need for surgical intervention was significantly associated with granulocyte percentage (2.768, 0.961-7.975, p = 0.059), CT findings of free intraabdominal fluid (28.000, 1.988-394.405, p = 0.014), and level of albumin (0.265, 0.073-0.970, p = 0.045). On multivariate analysis, the predictive factor was free intraabdominal fluid (28.000, 1.988-394.405, p = 0.014). Conservative treatment remains a major consideration in patients over the age of 80. Although major cases of adhensive SBO are successfully treated with conservative methods, some fail to respond, and the independent risk factor for surgical indication is free intraabdominal fluid.

Colonoscopy is the first choice for early postoperative rectal anastomotic bleeding.

BACKGROUND: Anastomotic bleeding is rare but is one of the dangerous complications, with associated morbidity and mortality, at the early stage of rectal cancer surgery. The aim of this study was to report our experiences in the treatment of this emergency condition. METHODS: We retrospectively analyzed the general characteristics, treatment and outcome of patients with severe anastomotic bleeding after undergoing rectal cancer resection with stapled anastomosis at the Department of Colorectal Surgery of Changhai Hospital (China) between January 2011 and December 2013. RESULTS: Anastomotic bleeding occurred in six out of 2,181 patients (0.3%) who underwent anterior resection with stapled anastomosis due to rectal cancer. All patients' bleeding was stopped with colonoscopic techniques. There were no anastomotic leakages or strictures in these six patients. CONCLUSIONS: Anastomotic bleeding was a very rare complication after rectal cancer resection with stapled anastomosis. Colonoscopic treatment, including electrocoagulation and clipping, were both safely and effectively used in the early postoperative period to cease persistent anastomotic bleeding.

Lower rate of colonoscopic perforation: 110,785 patients of colonoscopy performed by colorectal surgeons in a large teaching hospital in China.

BACKGROUND: Colonoscopic perforation (CP) has a low incidence rate. However, with the extensive use of colonoscopy, even low incidence rates should be evaluated to identify and address risks. Information on CP is quite limited in China. OBJECTIVE: Our study aimed to determine the frequency of CP in colonoscopies performed by surgeons at a large teaching hospital in China over a 12-year period. METHODS: A retrospective review of medical records was performed for all patients who had CPs from 1 January 2000 to 31 December 2012. Iatrogenic perforations were identified mainly by abdominal X-ray or computed tomography scan. Follow-up information of adverse events post-colonoscopy was identified from the colorectal surgery database of our hospital. Patients' demographic data, colonoscopy procedure information, location of perforation, treatment, and outcome were recorded. RESULTS: A total of 110,785 diagnostic and therapeutic colonoscopy procedures were performed (86,800 diagnostic cases and 23,985 therapeutic cases) within the 12-year study period. A total of 14 incidents (0.012%) of CP were reported (seven males and seven females), of which nine cases occurred during diagnostic colonoscopy (0.01%) and five after therapeutic colonoscopy (three polypectomy cases, one endoscopic mucosal resection, and one endoscopic mucosal dissection). Mean patient age was 67.14 years. One case of CP (7.14%) after colonoscopy polypectomy was treated using curative colonoscopy endoclips. Other patients underwent operations: six cases (46.15%) of primary repair, four cases (28.57%) of resection with anastomosis, and two cases (15.38%) of resection without anastomosis. No obvious perforation was found in one patient (7.69%). Surgeons attempted to treat one case laparoscopically but eventually resorted to open surgery. The postoperative course was uncomplicated in eight cases (57.14%) and complicated in six cases (42.86%) but without mortality. CONCLUSION: CP is a serious but rare complication of colonoscopy. A perforation risk of 0.012% was found in our study. The optimal management of CP remains controversial. Treatment for CP should be individualized according to the patient's condition, related devices, and surgical skills of endoscopists or surgeons. Selective measures such as colonoscopy without intravenous sedation and decrease of loop formation can effectively reduce rates of perforation.

Appropriate treatment of acute sigmoid volvulus in the emergency setting.

AIM: To investigate an appropriate strategy for the treatment of patients with acute sigmoid volvulus in the emergency setting. METHODS: A retrospective review of 28 patients with acute sigmoid volvulus treated in the Department of Colorectal Surgery, Changhai Hospital, Shanghai from January 2001 to July 2012 was performed. Following the diagnosis of acute sigmoid volvulus, an initial colonoscopic approach was adopted if there was no evidence of diffuse peritonitis. RESULTS: Of the 28 patients with acute sigmoid volvulus, 19 (67.9%) were male and 9 (32.1%) were female. Their mean age was 63.1 ± 22.9 years (range, 21-93 years). Six (21.4%) patients had a history of abdominal surgery, and 17 (60.7%) patients had a history of constipation. Abdominal radiography or computed tomography was performed in all patients. Colonoscopic detorsion was performed in all 28 patients with a success rate of 92.8% (26/28). Emergency surgery was required in the other two patients. Of the 26 successfully treated patients, seven (26.9%) had recurrent volvulus. CONCLUSION: Colonoscopy is the primary emergency treatment of choice in uncomplicated acute sigmoid volvulus. Emergency surgery is only for patients in whom nonoperative treatment is unsuccessful, or in those with peritonitis.

Massive presacral bleeding during rectal surgery: from anatomy to clinical practice.

AIM: To investigate control of two different types of massive presacral bleeding according to the anatomy of the presacral venous system. METHODS: A retrospective review was performed in 1628 patients with middle or low rectal carcinoma who were treated surgically in the Department of Colorectal Surgery, Changhai Hospital, Shanghai, China from January 2008 to December 2012. In four of these patients, the presacral venous plexus (n = 2) or basivertebral veins (n = 2) were injured with massive presacral bleeding during mobilization of the rectum. The first two patients with low rectal carcinoma were operated upon by a junior associate professor and the source of bleeding was the presacral venous plexus. The other two patients with recurrent rectal carcinoma were both women and the source of bleeding was the basivertebral veins. RESULTS: Two different techniques were used to control the bleeding. In the first two patients with massive bleeding from the presacral venous plexus, we used suture ligation around the venous plexus in the area with intact presacral fascia that communicated with the site of bleeding (surrounding suture ligation). In the second two patients with massive bleeding from the basivertebral veins, the pelvis was packed with gauze, which resulted in recurrent bleeding as soon as it was removed. Following this, we used electrocautery applied through one epiploic appendix pressed with a long Kelly clamp over the bleeding sacral neural foramen where was felt like a pit Electrocautery adjusted to the highest setting was then applied to the clamp to "weld" closed the bleeding point. Postoperatively, the blood loss was minimal and the drain tube was removed on days 4-7. CONCLUSION: Surrounding suture ligation and epiploic appendices welding are effective techniques for controlling massive presacral bleeding from presacral venous plexus and sacral neural foramen, respectively.