Abstract

Background: Sphincter of Oddi (SO) manometry (SOM) was considered as the gold standard for evaluating SO motility [1]. It is hard to endure pain for patients just given diazepam sedation instead of analgesics during SOM. However, there are controversial for analgesics to alleviate biliary pain. Therefore, it is necessary to further study the mechanism of analgesics on SO. Previous studies [2,3] have used some regular indexes during SOM to assess effects of analgesics on SO. However, none of these indexes is specific or permanent. Among these indexes, SO wave propagation direction can also be important. However, it has rarely been calculated.

Aim: To investigate the effects of analgesics and M-cholinoceptor blocking drugs on SO wave propagation direction.

Methods: Patients with placement of T-tube after cholecystectomy and choledochotomy from 2011 to 2015 were retrospectively reviewed. They were divided into the morphine, Ap-237, pethidine, tramadol and control group. The morphine group was divided into three subgroups on the basis of the effects of M-cholinoceptor blocking drugs against morphine: buscopan, atropine and anisodamine group. The following data were collected for all patients: demographic details, time of T-tube drainage, SO wave propagation data and use of corresponding analgesic drugs. Percentages of antegrade, retrograde and indeterminate waves were scored and analyzed by means of choledochoscopic manometry.

Results: A total of 140 patients were included. Median age was 55.5 years, 45% were male. All patients underwent cholecystectomy and choledochotomy, at least 1.5 months (mean 2.5 months) after T-tube drainage. The percentage of antegrade waves decreased at 10(10.97±1.62 vs 74.09±8.55, 14.17±2.80 vs 74.09±8.55, P<0.001) and 20min(16.25±1.17 vs 74.09±8.55, 22.90±1.40 vs 74.09±8.55,P<0.001) after injection of morphine and Ap-237, respectively. The percentage of indeterminate waves increased at 10(72.91±12.60 vs 19.11±2.25, 58.33±3.63 vs 19.11±2.25, P<0.001) and 20min (64.82±9.66 vs 19.11±2.25, 42.76±3.47 vs 19.11±2.25, P<0.001) after injection of morphine and Ap-237, respectively. The percentage of retrograde waves also increased markedly at 10(27.50±3.15 vs 7.94±1.19, P<0.01) and 20 min (30.05±2.42 vs 7.94±1.19, P<0.001) after injection of Ap-237. Buscopan and anisodamine blocked wave propagation abnormalities induced by morphine. The percentage of antegrade waves decreased and percentage of indeterminate waves increased 10min after injection of tramadol, but 20min later, these changes were not significant. Changes in percentages of antegrade, indeterminate and retrograde waves were not significant 10min after injection of pethidine.

Conclusion: SO, wave propagation with choledochoscopic manometry is an accurate method to investigate SO motility. Pethidine and tramadol rather than morphine and Ap-237 are better choices to alleviate biliary pain.

Core tip: This study investigated the effects of analgesics and M-cholinoceptor blocking drugs against morphine on SO wave propagation direction. We found that wave propagation is disturbed after injection of morphine and Ap-237. Buscopan and anisodamine can block wave propagation abnormalities induced by morphine. Pethidine and tramadol rather than morphine and Ap-237 appear to be the choice to alleviate biliary pain. In addition, as an important index during SOM, percentage of SO wave propagation can be more accurate than other indexes to investigate SO motility.

Keywords: Narcotic analgesics; Sphincter of Oddi; Wave propagation; Manometry; Choledochoscopy