OBJECTIVETo investigate the application value of colonic transit test (CTT) combined with anorectal manometry (ARM), barium enema (BE) and defecography (DFG) in accurately evaluating colonic lesions of slow transit constipation complicated with adult megacolon.

METHODSClinical data of 47 above patients admitted between October 2007 and February 2015 in the People's Hospital of Hunan Province were analyzed retrospectively. All the patients were examined with≥2 times of CTT combined with ARM and BE, and 42 cases received additional DFG at the same time, to evaluate colonic lesions before operation. Operative biopsy pathology was used as the standard. The sensitivity, specificity, positive predictive value(PPV) and negative predictive value(NPV) of positioning in the ascending colon and caecum, transverse colon and descending colon were calculated, and the consistency was represented by Kappa test(Kappa value≥0.75 indicates good consistency, meanwhile higher Kappa value indicates better consistency). The Heikkinen score was used to evaluate defecation function at postoperative 6 months.

RESULTSThe age of 47 patients was from 18 to 56 years old. Compared with intraoperative findings and biopsy pathology, the diagnostic coincidence rate was 89.4% by CTT combined with BE and DFG positioning, which suggested pathology-changed colonic segment locating in the ascending colon and cecum (n=12), transverse colon (n=26) and descending colon (n=9), while intraoperative findings and biopsy pathology suggested pathology-changed colonic segment locating in the ascending colon and cecum (n=11), transverse colon (n=23) and descending colon (n=13). The sensitivity was 88.3%, specificity 93.5%, PPV 92.1%, NPV 94.9% and Kappa value was 0.827(P<0.001). Procedures performed included segmental colectomy (n=8), subtotal colectomy (n=29), total colectomy (n=10). There was no serious complication during and after operation. Defecatory function was excellent in 24 cases (60.0%), good in 10 (25.0%), and moderate in 6 (15.0%) evaluated by Heikkinen score at postoperative 6 months. A total of 40 patients were followed up from 1 to 7 years (median 3 years) and there was no long-term diarrhea and recurrence of constipation or giant colon after operation.

CONCLUSIONPreoperative detection of CTT combined with ARM, BE and DFG in patients with slow transit constipation complicated with adult megacolon can make a more precise assessment of the extent of colonic lesions in advance, which has a good clinical predictive value.