ObjectiveTo evaluate the reasonableness of total mesorectal excision (TME) in the management of rectal cancer. Methods The carcinoembryonic antigen (CEA) level of surgically removed distal mesorectum (3?cm below the tumor),tumor tissue and normal mesocolon was detected by microparticle enzyme immunoassay in 26 rectal cancer patients. Results The CEA level in normal mesocolon was (1.6?1.0)?ng/g, and (62.5?85.2)?ng/g in distal mesorectum(P1?000?ng/g).ConclusionsIn patients with rectal cancer, much higher CEA level in distal mesorectum than in normal mesocolon might indicate distal mesorectal dissemination. It is necessary to routinely perform TME in the surgical management of middle and lower rectal cancer.

ObjectiveTo investigate the relationship between surgical manipulation and hematogenous spreading micrometastasis in patients with colorectal carcinoma.MethodsNested RT-PCR was used to detect the expression of cytokeratin 20 (CK20) mRNA in the peripheral blood of 37 colorectal cancer patients without distal metastasis (experimental group) undergoing radical resection which were subdivided into group A (tumor drainage veins were first ligated) and group B (without precedent ligation of the veins).Results CK20 mRNA was positive by nested RT-PCR in the peripheral blood in 9 out of 10 colorectal cancer patients with known distant metastasis,while it was negative in all 10 volunteers and all 10 patients with benign colorectal lesions. CK20 mRNA was detected in 14 of 37 (37 8%) cases in the peripheral blood sampled preoperatively, while the positive ratio rose to 59 5% (22/37) during surgical procedures (? 2=4 900, P0 05). ConclusionCK20 mRNA by nested RT-PCR was highly sensitive and specific for the determination of circulating micrometastasis in colorectal cancer patients. Surgical manipulation significantly increased the incidence of hematogenous spreading micrometastasis, which can′t be prevented by precedent ligation of the refluent veins of the tumor during operation.

Objective To evaluate transanal endoscopic microsurgery (TEM) for the resection of rectal neoplasms. Methods In order to analyze the therapeutic effect of TEM in the management of rectal tumors, clinical data of 110 patients with rectal neoplasms treated by TEM between April 2006 and August 2009 were summarized and analyzed retrospectively. Result The mean diameter of rectal lesions was 1.7±0.8 (range, 0.5 ～5.5)cm. The average distance of lesions from the anal verge was 7.4 ±2.6(range, 4 ～20) cm. 40 lesions were located at the anterior wall of the rectum, 29 on the posterior wall,22 on the left wall and 19 on the right. Surgical procedures included the transmural excision (98 cases) and the submucosal excision with partial muscular layer excision (12 cases). The average operating time was 73.5 ±31.1 (range, 25 ～180) min. The mean operative blood loss was 10.8 ±7.8 (range, 3 ～60) ml.The postoperative pathological examination identified 41 rectal adenomas、 35 rectal adenocarcinomas or carcinomatous changes of adenomas (21 Tis, 6 T1, and 8 T2 cases), 14 rectal carcinoids, 1 stromal tumor、1 leiomyoma and 18 cases of inflammatory polyps or others. Surgical margins of all specimens were negative.Postoperative complications included 2 cases of anal hemorrhage, one case of pulmonary infection and one urinary infection with a postoperative morbidity of 3.6%. The average postoperative stay was 3.4 ± 1.3( range, 2 ～ 8 ) d. With a mean follow-up period of 12. 5 (3 ～ 40) months, no tumor recurrence or metastasis was found. Conclusions TEM shows advantages of decreased blood loss, good therapeutic effect, and fast recovery of the patients, which can be adopted as the choice of therapy for small and well confined rectal neoplasms.

Objective To evaluate transsphincteric operation (Mason operation) for rectal tumors.Methods Retrospective study was used to analyze the experience of Mason operation for 150 patients with mid and lower rectal tumors between Aug 1990 to Dee 2008. Results There were villous adenoma in 75 cases,early rectal cancer in 48 and advanced rectal cancer in 9,submucosal carcinoid nodule in 23.Of the 126 rectal tumor patients,120 underwent partial rectectomy,6 underwent segmental rectectomy.Seventeen out of the 21 rectovaginal fistula or rectourethral fistula cases underwent successful one-stage repair.Six patients(4%)developed wound infection.Five patients(3.3%)were complicated with recto-cutaneous fistula.Two patients(4.3%) suffered from local recurrence in 46 followed up early staged rectal carcinoma with a five-year survival rate of 84.5%(39/46).On discharge from hospital no patient suffered from incontinence.Conclusion Mason operation is satisfactory with good exposure and simple access to the rectum,which Was suitable for those lesions that could be locally resected on mid and lower rectum.

Objective To investigate the causes and outcome of different treatment methods of iatrogenic rectovaginal fistula. Methods Clinical data of 52 patients with iatrogenic rectovaginal fistula were analyzed retrospectively. Results Twenty-two fistulae occurred after gynecological operation (42.3%), fourteen after obstetric injury (26.9%), thirteen after colorectal operation (25.0%) and three due to miscellaneous causes (5.8%). The fistulae were located in the lower rectum in 27 cases(51.9%), mid rectum in 10 cases(19.2%) and upper rectum in 15 cases(28.9%). They were treated by non-surgical treatment in 9 cases(17.3%), permanent diverting stoma(loop transverse colostomy) in 8 cases(15.4%), and surgical repair by various approaches in 35 cases(67.3%). The fistulae of all nine patients who received non-surgical treatment failed to heal. Eight patients who received permanent diverting stoma had symptomatic improvement without fistula healing. The overall cure rate of surgical repairs in 35 cases was 77.1%(27/35). The cure rates of trans-sphincteric (Mason′s operation), transanal, transabdominal, transperineal and transvaginal approaches were 100%(8/8), 100%(2/2), 83.3%(5/6), 0%(0/1) and 66.7%(12/18), respectively. The cure rate of Mason′s operation for the mid and lower rectovaginal fistulae was higher than that of transvaginal approach (100% vs 66.7%). Conclusions Iatrogenic rectovaginal fistula is caused by obstetric injury or injury of rectovaginal septum due to surgical mismanagement. Surgical repair is the only method that can cure rectovaginal fistulae. Mason′s operation is a favorable treatment method for the mid and lower (especially mid) rectovaginal fistulae.

Objective To investigate outcomes of transanal endoscopic microsurgery(TEM) for the treatment of rectal villous adenoma and early-stage rectal carcinoma.Methods A series of 31 patients with rectal tumors underwent TEM from November 1995 to December 2003.The operation was performed under general anesthesia.The patients were placed in a dependent position dictated by the location of the tumor.A special rectoscope was inserted into the anus with CO_2 insufflation to keep the rectum open.Under the stereoscope and laparoscopic-type instruments,the tumor was completely resected(submucosal or full-thickness excision) using a needle diathermy or a 5-mm ultrasonic dissector.The operative wound was closed with intra-lumen continuous sutures.Results The rectal tumor was completely removed with negative resection margins in all the 31 patients.The operating time was 45~220 min(mean,95 min) and the intraoperative blood loss was 0~180 ml(mean,40 ml).Complications included temporary flatus incontinence in 2 patients,acute retention of urine in 1 patient,exacerbation of chronic obstructive airway disease in 1,and secondary hemorrhage following Aspirin taking in 1.The postoperative pathological stages were pT_0 in 16 patients,pT_(is) in 2 patients,pT_1 in 7,pT_2 in 3,and pT_3 in 3.Follow-up checkups in the 31 patients for 2~92 months(mean,23 months) revealed no local recurrence.Conclusions TEM is a safe and effective minimally invasive surgical technique for the treatment of rectal villous adenoma and early rectal carcinoma.

Objective:To evaluate the clinical efficacy of transanal total mesorectal excision (taTME) on transanal endoscopic microsurgery (TEM) platform in the treatment of middle and low rectal cancer.Methods:The retrospective and descriptive study was conducted. The clinico-pathological data of 28 patients with middle and low rectal cancer who underwent taTME on TEM platform in the Peking Union Medical College Hospital of Chinese Academy of Medical Science from October 2014 to October 2017 were collected. There were 21 males and 7 females, aged 59 years (51 years, 68 years). Observation indicators: (1) surgical and postoperative situations; (2) follow-up. Follow-up was conducted using outpatient examination or telephone interview to detect post-operative defecation function and survival of patients up to October 2020. Patients underwent physical examination, examination of tumor markers including carcinoembryonic antigen and CA19-9, colonoscopy, rectal magnetic resonance imaging, thoracoabdominal and pelvic enhanced computed tomography (CT) and (or) PET-CT examination during the follow-up. Measurement data with normal distribution were represented as Mean±SD, and comparison between groups was analyzed using the independent sample t test. Measurement data with skewed distribution were represented as M( P25,P75) or M (range), and comparison between groups was analyzed using the non parameter Mann-Whitney U test. Count data were described as absolute numbers or percentages, and comparison between groups was analyzed using the chi-square test or Fisher exact probability. Results:(1) Surgical and postoperative situations: 28 patients underwent successful surgery, without intra-operative conversion to laparotomy. Of 28 patients, 24 cases underwent colorectal anastomosis and 4 cases underwent colon-anal anastomosis. Twenty-six cases underwent primary protective enterostomy and 2 cases didn't undergo primary protective enterostomy. The operation time of 28 patients was (182±37)minutes and the volume of intraoperative blood loss was 40mL(30 mL, 55 mL). One patient with intraoperative presacral hemorrhage received compression hemostasis. Eleven patients had postoperative complications, including 4 cases with anastomotic leakage, 2 cases with alteration of intestinal flora, 2 cases with paralytic ileus, 2 cases with urinary retention, 2 cases with urinary infection, 1 case with prolapse necrosis of small intestinal stoma, 1 case with anal hemorrhage, 1 case with rectovaginal fistula, 1 case with pelvic infection; some patients had multiple complications. Three patients had non-planned reoperation. One case without primary protective enterostomy had anastomotic leakage at postoperative 3 days, and was improved after emergency transversostomy. One case had prolapse necrosis of small intestinal stoma at postoperative 3 days and was improved after emergency enterostomy and reconstruction. One case with anal hemorrhage was stopped hemorrhage under anoscopy. Patients with other complications were cured after conservative treatments. The duration of postoperative hospital stay of 28 patients was 8 days(7 days, 9 days). Results of pathological examination in 28 patients showed 16 cases of moderately differentiated adenocarcinoma, 3 cases of moderately to highly differentiated adenocarcinoma, 5 cases of highly differentiated adenocarcinoma, 1 case of mucinous adenocarcinoma, 3 cases of pathological complete response. TNM staging of 28 patients showed 3 cases in stage T0N0, 4 cases in stage T1N0, 6 cases in stage T2N0, 4 cases in stage T2N1, 7 cases in stage T3N0, 3 cases in stage T3N1, 1 case in stage T4N1. The distance from tumor to distal margin was (2.2±1.7)cm. The surgical specimens of 28 patients showed negative for proximal, distal and circumferential margins. The number of lymph node dissection was 15±7. The complete rate of total mesorectal excision was 100%(28/28). Eleven of 28 patients underwent neoadjuvant therapy and 17 patients didn't receive neoadjuvant therapy. The tumor diameter, distance from tumor to anal margin, operation time, volume of intraoperative blood loss, duration of postoperative hospital stay were 2 cm(1 cm, 4 cm), 5 cm(4 cm, 6 cm), (187±25)minutes, 45 mL(38 mL, 53 mL), 8 days(7 days, 12 days) for patients with neoadjuvant therapy, respectively, versus 3 cm(2 cm, 4 cm), 5 cm(4 cm, 6 cm), (177±35)minutes, 40 mL(30 mL, 60 mL), 8 days(7 days, 8 days) for patients without neoadjuvant therapy, showing no significant difference between the two groups ( Z=-1.127, -0.293, t=0.590, Z=-0.790, -0.876, P>0.05). (2) Follow-up: 23 of 28 patients were followed up for (44±14)months. Of the 23 patients,11 cases were classified as grade A of Williams score for defecation function at postoperative 6 months, 8 cases were classified as grade B and 4 cases were classified as grade C. Eighteen of 23 patients with follow-up had disease-free survival, 1 of whom didn't undergo stoma closure due to anastomotic stenosis at postoperative 6 months. Three patients had distant metastasis, including 1 case with parastomal implantation metastasis, 1 case with sacral metastasis, 1 case with pulmonary metastasis. Two patients died, 1 case of whom died of urinary obstruction and 1 case with mucinous adenocarcinoma died at postoperative 24 months. Conclusion:TaTME based on TEM platform is feasible for middle and low rectal cancer, which has the advantages of preserving anus and negative circumferential margin.

Laparoscopic-assisted colon surgery is an alternative to open surgery. Furthermore, complete mesocolic excision (CME) as a new concept in colon cancer surgery was first proposed by Hohenberger from Germany, which follows the oncological principle of the tumor and is based on the embryology and anatomy. Some researches about CME showed that this procedure could improve the prognosis, decrease the local recurrence of the tumor without increased complications. Although a laparoscopic approach for right colon cancer is performed frequently, identifying an adequate dissection plane is not always easy. The surgeons need to know well about local anatomy of laparoscopic-assisted radical right hemicolectomy, and to master the right surgical plane in operation process, then to reduce the incidence of conversion to laparotomy and side injury. The superior mesenteric vein (SMV) is the key landmark. The fusion fascia space is the right surgical plane, as well as a series of peripheral peritoneal attachments are important fixations in laparoscopic right hemicolectomy by medial access. Identifying the anatomical location of the SMV and performing meticulous dissection along the SMV is an essential procedure to dissect all potential lymphatic drainage during laparoscopic CME for right colon cancer.
Colectomy ; Colonic Neoplasms ; Humans ; Laparoscopy ; Mesenteric Veins ; Mesocolon ; Prognosis

The development of transanal endoscopic microsurgery (TEM) during the last 30 years has led to the evolution of the treatment in rectal neoplasms. TEM has revolutionized the technique and outcomes of transanal surgery. To our knowledge, this technique is currently the only one-port system in endoscopic surgery by which a direct endoluminal approach to the target organ by using a natural opening of the body become available. TEM affords the advantage of a less invasive transanal approach with low recurrence rates secondary to a more precise dissection due to enhanced visualization of the surgical field. Currently, TEM represents the standard treatment modality for large rectal adenomas and a surgical option in selected early rectal cancers. Its potential role in the treatment of more invasive cancer in combination with neoadjuvant therapies, and other rectal localized tumors are currently under evaluation. The current trend of TEM is favorable in China. TEM has also been increasingly used in the treatment of rectal neoplasms, but there are many problems in the development of TEM, for example, preoperative assessment is inadequate, patient selection is not precise enough, the surgical procedure is not standardized, etc. These problems require the majority of surgical colleagues to work together to make the standards scientifically and objectively in accordance with the actual situation of our country, so as to promote the healthy development and popularity of TEM in China.
Adenoma ; China ; Humans ; Neoadjuvant Therapy ; Patient Selection ; Rectal Neoplasms ; Transanal Endoscopic Microsurgery

Precision medicine is to customize the treatment options for individual patient based on the personal genome information. Colorectal cancer (CRC) is one of the most common cancer worldwide. Molecular heterogeneity of CRC, which includes the MSI phenotype, hypermutation phenotype, and their relationship with clinical preferences, is believed to be one of the main factors responsible for the considerable variability in treatment response. The development of powerful next-generation sequencing (NGS) technologies allows us to further understand the biological behavior of colorectal cancer, and to analyze the prognosis and chemotherapeutic drug reactions by molecular diagnostic techniques, which can guide the clinical treatment. This paper will introduce the new findings in this field. Meanwhile we integrate the new progress of key pathways including EGFR, RAS, PI3K/AKT and VEGF, and the experience in selective patients through associated molecular diagnostic screening who gain better efficacy after target therapy. The technique for detecting circulating tumor DNA (ctDNA) is introduced here as well, which can identify patients with high risk for recurrence, and demonstrate the risk of chemotherapy resistance. Mechanism of tumor drug resistance may be revealed by dynamic observation of gene alteration during treatment.
Colorectal Neoplasms ; Drug Resistance, Neoplasm ; Humans ; Molecular Diagnostic Techniques ; Mutation ; Patient Selection ; Phenotype ; Phosphatidylinositol 3-Kinases ; Precision Medicine ; Prognosis ; Recurrence