The secondary CBD stone may cause many clinical symptoms and signs, including abdominal pain, obstructive jaundice, cholangitis, and biliary pancreatitis, etc [2]. Like patients in this article, there were as many as 52 patients diagnosed as obstructive jaundice. The ideal management remains a matter of debate [5]. As far as LCBDE is concerned, the problems are mainly related to T-tube placement, such as patient discomfort, biliary peritonitis, T-tube displacement, etc [15-16]. In view of this, some surgeons tried to make full use of the natural cystic duct with micro-incision on CBD or confluence followed by primarily suture [13-14]. Inspired by this, we further speculate: could we use the natural orifices comprising of cystic duct and its confluence at the CBD with no incision? Therefore, LTD-CBDE was designed for CBD exploration and stones extraction via laparoscopic transcystic approach by dilating the confluence. Dilation of the confluence making the insertion of the choledochoscope and stones extraction easier, because is it not only overcomes the problems that the cystic duct is thin and the spiral valve acts as a barrier in exploration, but also enlarges the inlet diameter of the CBD greater or equal to the outer diameter of the largest stone. CBD blood supply is not affected by incision so that CBD stenosis may be prevented. The operations were performed smoothly. Success rate was 91.2% (may be higher with careful perioperative identification of the indications), clearance rate of CBDS was 100%, and retained stones were not identified on postoperative follow-up.
The success rate of 91.2% with present method coincides with 88.1% reported in meta-analysis of eleven randomized trials for LCBDE [5]. By using a slightly different approach with a micro-incision at the confluence, Chen et al. and Niu et al reported a success rate of 100% [13-14]. The 6 failed patients in our work were associated with anatomical problems, suggesting the importance of a carefully selected surgical strategy. Special attention should be paid to the following aspects: Firstly, it is crucial to maintain the cystic duct intact, so as to facilitate the incision, dilation, choledochoscope insertion, observation, stones extraction and primary closure. Secondly, identify the confluence correctly and avoid its damage. Finally, limiting factors of success with LTD-CBDE include anatomic features related to the cystic duct and confluence, such as fibrosis and anatomical abnormality of the Calot’s triangle, small-size or atretic or tortuous duct, and low level of or posterior insertion of the cystic duct on the CBD, etc.
The operation time reported in the literatures varies widely depending on the surgical method, ranging from 104 to 194 minutes [2, 13, 17, 18]. The mean operating time was 105 minutes in our series. However, we don’t think it is reasonable to directly compare the operation time, because any new modality requires more operation time, and is technically difficult with a clear learning curve. In the future, along with technical improvement and more effective logistic organization, the operation time will be further reduced. Patients in our study were discharged after a mean postoperative hospital stay of 5.9 days, which is not longer than other reports with mini-incision (mean 8 days) or LCBDE [5, 17, 18]. Mortality is also in accordance with the findings of other surgical modality [13-14]. Forty-three cases were followed up one year after LTD-CBDE operation (25 patients lost to follow up) and none of them presented with evidence of retained or recurrent CBDS and stenosis of CBD.
Our LTD-CBDE is safe and effective, but a carefully selected surgical strategy should be especially emphasized as suggested by Gigot et al. [18]. Firstly, for patients with anatomical abnormalities or intraperitoneal adhesions as 6 patients shown in our series, the traditional open operation or laparoscopic choledochotomy should be considered as soon as possible. Secondly, despite careful suturing of the confluence with stump wall, there were still 3 cases suffering postoperative bile leakage. This is not higher than the incidence of LCBDE (5.6% with experienced surgeons vs 17.1% with inexperienced surgeons) reported by liu et al. [19]. As analyzed by liu. et al. [19], it is clear that postoperative bile leakage (and the like) can be reduced with gaining of experience in the technique [20]. Thirdly, in our series, the separation forceps, rather than the balloons, were used in most patients. It is undeniable that the latter provides a quantitative and accurate degree of expansion, thus improving safety accordingly. However, Yunnan is a poor province in China, and most patients cannot afford the expensive balloon. Therefore, we chose the separation forceps rather than the balloons to dilate the confluence,and fortunately, the majority of patients, who used the separation forceps to dilate the confluence have achieved successfully surgery with LTD-CBDE technique. Fourthly, this is a retrospective analysis. The surgical method was selected subjectively rather than randomly, and that’s why we did not take the remaining 114 patients with LCBDE as a control. Robust RCT research will be our next goal. Finally, although we hypothesized that LTD-CBDE has the potential to reduce postoperative bile duct stricture, this is currently not confirmed and further research is needed. The optimal management of CBDS depends on the skills and techniques of the surgical team available. In any case, minimally invasive or non-invasive procedures should be the direction of our efforts.