Requirement of drainage strategy for acute cholecystitis in patients with high surgical risk.

Abstract

According to the Tokyo Guidelines 2018 (TG18), the standard treatment strategy for acute cholecystitis is laparoscopic cholecystectomy.1 However, gallbladder drainage is indicated when the risk of emergency surgery is deemed high based on the Charlson Comorbidity Index and the American Society of Anesthesiologists Physical Status scores. The standard recommended drainage technique is percutaneous transhepatic gallbladder drainage (PTGBD) owing to its high technical success rate and high clinical success rate; however, long-term outcomes have not been considered in this recommendation. In some cases, elective cholecystectomy can also be high risk, due to the patient's general condition or their wish to avoid surgical treatment after gallbladder drainage has resolved acute cholecystitis. In such cases, the strategy for gallbladder drainage must consider long-term management, including prevention of recurrence. In terms of long-term management, endoscopic drainage techniques are promising, such as endoscopic transpapillary gallbladder drainage (ETGBD) or endoscopic ultrasound-guided gallbladder drainage (EUS-GBD), which allows for internal drainage.2 Although ETGBD is a safe and useful treatment for acute cholecystitis, obstruction of the cystic duct due to tortuosity and inflammation makes the procedure technically challenging, and a systematic review reported a pooled technical success rate of 80–83%, which is lower than that for PTGBD or EUS-GBD.3 In terms of long-term outcomes, some studies have reported that endoscopic placement of a long-term stent in the gallbladder of high-risk surgical patients after ETGBD was associated with lower recurrence of cholecystitis compared with PTGBD. However, a recent long-term comparative study highlighted that longer indwelling periods after ETGBD were associated with a higher occurrence of other late adverse events such as common bile duct stone, cholangitis, or gallbladder perforation.4 Many recent studies have reported the efficacy of EUS-GBD, including long-term outcomes, yet serious adverse events such as biliary peritonitis caused by technical failure are a concern. The development of devices such as the one-step deployment system for lumen-apposing metal stents (LAMS) and the accumulation of technical experience have led to EUS-GBD becoming more widely used in high-volume centers. In a recent meta-analysis comparing EUS-GBD with PTGBD for the management of acute cholecystitis, in a total of 495 patients, EUS-GBD was associated with a significantly lower adverse events rate, shorter hospital stays, and a lower re-intervention rate, with no significant difference in relation to technical and clinical success rates.5 Based on these clinical data, recent European Society of Gastrointestinal Endoscopy guidelines recommend that EUS-GBD should be favored over PTGBD for patients with high surgical risk when both techniques are available, owing to the lower rates of adverse events and need for re-intervention associated with EUS-GBD.6 The efficacy and safety of conversion from PTGBD to EUS-GBD in patients with high surgical risk has also been reported.7 Certainly, long-term management of the percutaneous drainage tube after PTGBD has disadvantages such as discomfort, pain, and skin problems. However, in clinical practice, the drainage tube can be removed early in some cases if a tube cholecystogram shows a patent cystic duct following the resolution of gallstone impaction. This is an important point because it affects long-term clinical outcomes, but it has not been taken into consideration in previous studies. In this issue of Digestive Endoscopy, Cho et al.8 retrospectively compared the short- and long-term clinical outcomes of EUS-GBD when using a fully covered metal stent with antimigration function and PTGBD categorized into an ex situ group (tube removal group) and in situ group (tube remaining group). They report similar technical and clinical success rates between the EUS-GBD and PTGBD groups, although early adverse events were less common in the EUS-GBD group. Furthermore, the recurrence rate of cholecystitis in the EUS-GBD group (6.0%) was similar to that in the PTGBD ex situ group (9.6%) but significantly lower than that in the PTGBD in situ group (23.5%). These results support the following treatment strategies for acute cholecystitis in patients with high surgical risk at institutions where EUS-GBD cannot be performed. First, PTGBD is performed, and after the cholecystitis improves, tube cholecystography is performed. If the cystic duct is patent, the percutaneous drainage tube is removed. If the cholecystic duct is obstructed, the patient is transferred to institutions where EUS-GBD can be performed. For long-term management, conversion to EUS-GBD targets the prevention of recurrence. Many studies have reported on optimal strategies for gallbladder drainage in patients with high surgical risk, but several issues remain to be resolved. The risk factors for emergency cholecystectomy have been well investigated, and TG18 provides clear criteria for this procedure depending on the severity of cholecystitis and the patient's general condition. However, there are no clear criteria for elective cholecystectomy after gallbladder drainage. For patients at high risk for emergency cholecystectomy, a comparative study of elective cholecystectomy after drainage vs. drainage treatment strategies is warranted to examine long-term outcomes, including prevention of recurrence. Furthermore, despite increasing reports of the usefulness of EUS-GBD, including its long-term outcomes, a standard technique has not been established and varies among studies. In particular, the type of drainage stents placed often differ. EUS-GBD most commonly uses fully covered biliary metal stents, but some have additional antimigration features or other novel design advantages (e.g., the novel tornado metal stent9), and it should be noted that there is currently insufficient evidence about long-term outcomes.2 LAMS show promise for EUS-GBD for acute cholecystitis, with a delivery system that allows for one-step deployment, a high drainage capacity, and a strong lumen-apposing function, which makes them highly effective in preventing stent migration. However, there are concerns about the safety of their long-term placement (i.e., buried stent syndrome), especially in the case of the transgastric approach. When LAMS are placed for EUS-GBD, it is possible to treat gallstones (the cause of cholecystitis) through the lumen of the LAMS after drainage. One recent randomized controlled trial reported better long-term outcomes, including recurrence of cholecystitis, with a treatment strategy of EUS-GBD with LAMS followed by additional treatment of gallstones and finally LAMS removal than with PTGBD.10 It is necessary to establish a standard treatment strategy for acute cholecystitis with EUS-GBD that considers long-term outcomes, and then compare the strategy with that of elective cholecystectomy after emergency drainage or other drainage treatment strategies in patients with high surgical risk. Author T.I. is a consultant for Boston Scientific Japan. The other author declares no conflict of interest for this article. None.