OBJECTIVETo explore the effect of arterial infusion with methylene blue during total mesorectal excision (TME) for better preservation of pelvic autonomic nerve on urination function and sexual function in male patients with rectal cancer.

METHODSA total of 68 male rectal cancer patients from Zhejiang Xiaoxing People's Hospital and 44 male rectal cancer patients from Guangdong Zhongshan Chenxinghai Hospital between June 2013 and June 2015 were prospectively enrolled. Patients were randomly divided into the trial group receiving arterial infusion with 8 ml of 1% methylene blue and the control group without artery infusion, with 56 cases in each group. All the patients underwent TME. Intra-operational lymph node removal and postoperative urination and sexual function (erection and ejaculation) were compared between two groups.

RESULTSThe baseline data of the two groups were not significantly different (all P>0.05). As compared to the control group, the trial group had shorter operation time [(3.28±0.63) hours vs. (4.01±0.94) hours, P<0.01], less blood loss[(92.5±36.4) ml vs. (174.1±61.4) ml, P<0.01], and more lymph nodes harvested per patient (15.8±7.6 vs. 11.9±4.3, P<0.01). One year after operation, classI(, II(, III(, IIII( of urination was observed in 33 cases (58.9%), 15 cases (26.8%), 6 cases (10.7%), 2 cases (3.6%) in the trial group, while 24 (42.9%), 15 (26.8%), 12 (21.4%), 5 (8.9%) in the control group, which indicated that trial group was superior to control group(P<0.05). ClassI(, II(, III( of erection was observed in 36 cases (64.3%), 18 cases (32.1%), 2 cases(3.6%) in the trial group, while 25(44.6%), 23(41.1%), 8(14.3%) in the control group, which indicated that trial group was superior to the control group (P<0.05). ClassI(, II(, III( of ejaculation was found in 36 cases (62.5%), 18 cases (32.1%), 3 cases (5.4%) in the trial group, while 24 (42.9%), 22 (39.3%), 10(17.9%) in the control group, which also indicated that trial group was superior to the control group(P<0.05).

CONCLUSIONSIn the treatment of male rectal cancer patients, TME combined with arterial infusion with methylene blue can facilitate the distinction of operation scope, which is beneficial to reduce damages to the pelvic nerve, leading to the protection of urinary function and sexual function. In addition, this procedure can result in shorter operation time, less operational blood loss and more lymph nodes harvested.