Clinical risk factors for anastomotic leakage after laparoscopic anterior resection for rectal cancer: a systematic review and meta-analysis.

BACKGROUND: Anastomotic leakage (AL) is a serious complication in laparoscopic rectal cancer surgery, and risk factors for AL are not well defined. Herein, we conducted a systematic review to quantify the clinicopathologic factors predictive for AL in patients who underwent laparoscopic anterior resection (LAR) for rectal cancer. METHODS: A systematic search of electronic databases (PubMed, Embase, Cochrane CENTRAL, Scopus Database, and Wanfang Database) for studies published until August 2014 was performed. Cohort, case-control studies, and randomized controlled trials that examined clinical risk factors for AL were included. RESULTS: Fourteen studies (seven prospective and seven retrospective studies) involving 4580 patients met final inclusion criteria. From the pooled analyses, five demographic factors were found to be significantly associated with the development of AL, including male gender (OR 2.04, 95% CI 1.50-2.77), BMI ≥25 kg/m(2) (OR 1.46, 95% CI 1.00-2.14), ASA score >2 (OR 1.74, 95% CI 1.04-2.93, P = 0.04), tumor size >5 cm (OR 1.63, 95% CI 1.01-2.64, P = 0.05), and preoperative chemotherapy (OR 1.67, 95% CI 1.10-2.55, P = 0.02). Four operative factors were significantly associated with increased risk of AL, including longer operative time (95% CI 1.71-5.77, P = 0.0002), number of stapler firings ≥3 (OR 0.17, 95% CI 0.07-0.41, P < 0.001), intra-operative transfusions/blood loss >100 mL (OR 3.79, 95% CI 2.48-5.49, P < 0.001), and anastomosis level within 5 cm from the anal verge (OR 9.63, 95% CI 3.05-30.43, P = 0.0001), while pelvic drain (OR 0.43, 95% CI 0.19-0.94, P = 0.04) was significantly associated with a lower AL rate. CONCLUSION: Our analysis identified several clinicopathologic factors associated with AL in patients who underwent LAR. The knowledge of these risk factors may influence treatment- and procedure-related decisions and possibly reduce the leakage rate.

The parasympathetic supply to the distal colon-one marker for precisely locating the posterior dissection plane in the operation of TME.

BACKGROUND: It is important for surgeons to locate the reliable surgical planes in the operation of total mesorectal excision (TME); we observe the parasympathetic nerve to the distal colon can be served as one of useful markers for precisely locating the posterior dissection plane in TME. MATERIALS AND METHODS: From October 2006 to January 2008, 26 patients underwent TME for rectal cancer. The dissections of the parasympathetic nerves to the distal colon were performed and the relationship of these nerves to the prehypogastric nerve fascia was observed. RESULTS: Some parasympathetic nerves ran upwards and lay anteromedial to the hypogastric nerves. In the avascular space between prehypogastric nerve fascia and the fascia propria of the rectum, the prehypogastric nerve fascia enveloped parasymphathetic nerve up to the fascia propria of rectum. CONCLUSIONS: The parasympathetic nerve to the distal colon is evident between the fascia propria of the rectum and the prehypogastric nerve fascia. As the precise dissection plane of TME lay between the fascia propria of the rectum and the prehypogastric nerve fascia, these nerves could be served as useful marker for precisely locating the posterior dissection plane in TME.

Preservation of the continence function after intersphincteric resection using a prolapsing technique in the patients with low rectal cancer and its clinical prognosis.

BACKGROUND: The technique of intersphincteric resection of tumors combined with coloanal anastomosis has been used to avoid permanent colostomy for patients with a rectal cancer located < 5 cm from the anal verge. This study aimed at assessing the preservation of continence function of the residual rectum and the clinical prognosis of patients with lower rectal cancer after intersphincteric resection using a prolapsing technique. METHODS: This study included patients with the following inclusion criteria: (1) pathological evidence of rectal cancer and the tumors within distal margins located 5 cm or less from the anus by preoperative endoscopic examination; (2) no evidence by MRI of infiltration of either the external sphincter, puborectalis or the levator muscle; (3) the patients are eligible for intersphincteric resection and lower coloanal anastomosis with a preoperative biopsy showing the tumors with well-to-moderate differentiation. From January 2000 to June 2004, 23 patients with low rectal cancer were included in this study. We used the standard abdominoperineal approach to perform radical resection of tumors with excision of the mesorectum and total or part of the internal sphincters. The patients were followed for assessment of the function of the residual rectum and of cancer recurrence after the operations. RESULTS: The median tumor distance from the anal margin was 4.5 (range 3.5 - 5.0) cm and the mean distal surgical margin 1.6 (range 1.0 - 2.0) cm. Cancer was classified into Stage I (30.4%), Stage II (47.8%), and Stage III (21.7%) according to the TNM classification. Two patients developed anastomotic fistula after the surgical resection and 2 patients (8.7%) developed later stages of anastomotic stricture at the site of coloanal anastomosis. The median follow-up period was 31.5 months (range 12 - 54) and 2 patients (8.7%) developed local recurrence. Three deaths were associated with distal organ metastasis. Twenty patients (87.0%) have maintained competence to control solid or liquid stool and the capacity of flatus continence after the surgery. Among these patients, 2 patients were able to control solid stool and occasionally lose continence of liquid stool. And only 1 patient (4.4%) has retained partial rectum function with good continence of solid stool but not liquid after the operations. Average times of defecation per day of 3, 6, 12, 24 and 36 months after the surgery were 13.1, 4.7, 3.1, 2.9, and 3.2 times/day. Anal manometer measurements showed a decrease of pressure during the resting time after intersphincteric resection and this change remained during the period of follow-up. The maximum squeeze pressure was improved after an initial decrease after the surgery. CONCLUSIONS: More residual rectum function after the surgery may be preserved by intersphincteric resection of low rectum cancer. At the same time this technique is safe with few postoperative complication and low tumor recurrence after the surgery.

Vascular anatomy of inferior mesenteric artery in laparoscopic radical resection with the preservation of left colic artery for rectal cancer.

AIM: To investigate the vascular anatomy of inferior mesenteric artery (IMA) in laparoscopic radical resection with the preservation of left colic artery (LCA) for rectal cancer. METHODS: A total of 110 patients with rectal cancer who underwent laparoscopic surgical resection with preservation of the LCA were retrospectively reviewed. A 3D vascular reconstruction was performed before each surgical procedure to assess the branches of the IMA. During surgery, the relationship among the IMA, LCA, sigmoid artery (SA) and superior rectal artery (SRA) was evaluated, and the length from the origin of the IMA to the point of branching into the LCA or common trunk of LCA and SA was measured. The relationship between inferior mesenteric vein (IMV) and LCA was also evaluated. RESULTS: Three vascular types were identified in this study. In type A, LCA arose independently from IMA (46.4%, n = 51); in type B, LCA and SA branched from a common trunk of the IMA (23.6%, n = 26); and in type C, LCA, SA, and SRA branched at the same location (30.0%, n = 33). The difference in the length from the origin of IMA to LCA was not statistically significant among the three types. LCA was located under the IMV in 61 cases and above the IMV in 49 cases. CONCLUSION: The vascular anatomy of the IMA and IMV is essential for laparoscopic radical resection with preservation of the LCA for rectal cancer. To recognize different branches of the IMA is necessary for the resection of lymph nodes and dissection of vessels.

[Application of single stapler combined with prolapsing technique in anterior resection of ultra-low rectal cancer].

OBJECTIVE: Evaluation of single stapler combined with prolapsing technique for anus-preserving of ultra-low rectal cancer and its indication as well as surgical procedure. METHODS: Forty-three patients with ultra-low low rectal cancer suitable for anterior resection were divided into two groups, single stapler combined with prolapsing technique was applied for experiment group, conventional double stapler technique was applied for control group. To compare the distal margin, local recurrence rate, complications, anal continence function and expenses. RESULTS: The distal margin of experimental group is significantly longer than that of control group (2.2 cm +/- 0.2 cm VS 1.9 cm +/- 0.4 cm, P = 0.006). The distance between dentate line and distal incision line of control group is much longer than experimental group (1.9 cm +/- 0.5 cm VS 1.3 cm +/- 0.3 cm, P < 0.001). There is no recurrence in experimental group but 3 cases recurrence within 1 year in control group. The anastomose fistula rate, instrument expenses of experimental group are less than those of control group. There is no distinct in anal continence between two groups. Occasional minor soiling is present in 1 case of experimental group. CONCLUSION: Single stapler combined with prolapsing technique is superior to double stapler technique for anus-preserving of ultra-low rectal cancer.

[Accuracy of preoperative magnetic resonance imaging in prediction of pathological stage and circumferential resection margin in rectal cancer].

OBJECTIVE: To evaluate the accuracy of preoperative magnetic resonance imaging (MRI) in prediction of pathological staging and involvement of circumferential resection margin (CRM) in rectal cancer. METHODS: Fifty-three patients undergoing total mesorectal excision for biopsy-proven rectal cancer were assessed prospectively using high-resolution MRI for tumour (T) and mesorectal nodal (N) staging as well as CRM status using the depth of tumour spread, tumour node metastasis and CRM involvement. Preoperative MRI assessment of these prognostic factors was compared with the histopathological findings in carefully matched whole-mount sections of the specimen. RESULTS: MRI correctly staged the tumor in 41 patients, understaged in 8, and overstaged in 4. The accuracy of T stage was 77.4% (41/53). There was ageneric correlation between pathologic and MRI tumor staging (Kappa = 0.602, P < 0.001). Node status was correctly staged in 37 patients, overstaged in 10, and understaged in 6. The accuracy of node staging was 69.8% (37/53), sensitivity was 75% (18/24), and specificity was 65.5% (19/29). The correlation between pathologic and MRI node staging was poor (Kappa = 0.399, P = 0.003). The CRM status was correctly reported in 51 patients, overstaged in 1, and understaged in 1. The accuracy of CRM status was 96.2% (51/53), sensitivity was 80% (1/5), and specificity was 97.9% (47/48). There was a good correlation between pathologic and MRI CRM involvement (Kappa = 0.779, P < 0.001). CONCLUSION: Preoperative MRI provides poor predictive data as to subsequent pathologic tumor and mesorectal node stage, but does produce reliable prediction of clear CRM.

[Status of estrogen receptor affects the drug sensitivity of drug-resistant MCF-7/Adr human breast cancer cells to droloxifene and Adriamycin].

BACKGROUND & OBJECTIVE: Loss or decreased expression of estrogen receptor (ER) and decreased growth rate regularly occur in drug-resistant breast cancer cells. This study was designed to investigate the effect of estrogen receptor status on the drug resistance to droloxifene (Dro) and Adriamycin (Adr) of drug-resistant MCF-7/Adr human breast cancer cells. METHODS: The expression of ER in MCF-7 and MCF-7/Adr cells was determined using Western blot analysis. ER expression plasmid was constructed and introduced into MCF-7/Adr cells using LipofectAMINE. After G418 screening, the positive clone (MTER/Adr) was obtained. The integration and expression of ER gene were analyzed by polymerase chain reaction (PCR) and Western blot. The cell cycle distribution was investigated by flow cytometry. The effects of droloxifene and Adriamycin on the growth of cells were investigated by MTT assay. RESULTS: Western blot analysis showed that ER was positive in MCF-7 cells, but was negative in MCF-7/Adr cells. The ER expression plasmid was constructed and introduced into MCF-7/Adr cells. The integration and expression of ER gene were successful in positive clone -MTER/Adr cells. Droloxifene inhibited the growth of MCF-7 at the concentration of 10-20 micromol/L and the MCF-7/Adr only at concentration of 20 micromol/L. Droloxifene inhibited the growth of MTER/Adr at the concentration of 15 micromol/L, and the percentage of MTER/Adr cells increased in G0/G1 phase. The sensitivity of MTER/Adr cells to Adriamycin increased. CONCLUSION: The insensitivity of MCF-7/Adr human breast cancer cells to droloxifene was associated with the loss of ER. MTER/Adr cells partially restore the sensitivity to droloxifene and Adriamycin.