Beyond the end: a cholangioscope in the appendix – a new tool for the management of acute appendicitis?

As endoscopy fellows, each of us has been taught that the identification of the appendiceal orifice is the goal of colonoscope progression, ensuring examination of the entire colon. In this issue of Endoscopy, Kong et al. push the boundaries and propose examination of the appendiceal lumen with a single-operator cholangioscope (SOC) to provide tailored endoscopic retrograde appendicitis therapy (ERAT) [1]. This new application of an SOC is adapted from the fluoroscopic-guided ERAT technique, a minimally invasive treatment first described in 2012 [2].

“Endoscopic retrograde appendicitis therapy, with or without single-operator cholangioscopy, can be considered in the emergency toolbox for the management of uncomplicated acute appendicitis, especially in patients with appendicolith, but further studies are necessary to determine its place compared with antibiotics alone or standard surgery.”

In the “conventional” ERAT technique, a colonoscope with a transparent cap is advanced to the cecum and the appendiceal orifice, and the appendix cavity is catheterized with a guidewire and filled with contrast through a canula, allowing visualization of stenosis or appendicolith and endoscopic treatment with basket or balloon extraction, or stenting.

In the King et al. study, 14 patients were diagnosed with uncomplicated appendicitis based on clinical and biological examinations, and computed tomography or ultrasonography findings. All of them were successfully treated with ERAT, with direct visualization of the appendix cavity using an SOC passed through the operative channel of a standard colonoscope. Half of the patients presented appendicolith, which was removed in all cases (four with irrigation, two with basket, and one requiring laser lithotripsy). A plastic stent was placed in four cases. The mean procedure time was 37.8 (SD 22) minutes, abdominal pain was relieved immediately after ERAT in all patients, and the mean length of hospitalization after endoscopy was 1.9 (SD 0.7) days. In one case of a pregnant women, no X-rays were used. For the authors, the main advantages of the cholangioscope-assisted ERAT procedure were the accurate diagnosis of appendicitis, the certainty of removing all appendicoliths, and the possibility of avoiding X-rays, especially in patients who were pregnant.

Although acute appendicitis is the most common cause of acute abdominal pain, its management is still debated, especially in cases of uncomplicated appendicitis, which accounts for approximately 80 % of cases. For decades, the standard treatment was open surgical appendectomy, which was progressively replaced by laparoscopic appendectomy, resulting in lower morbidity, shorter length of hospitalization, and less postoperative pain, despite being more costly [3]. More recently, a conservative treatment with antibiotics has been studied through several trials, leading to the acknowledgment of a nonoperative strategy as a safe alternative to surgery in patients without appendicolith, according to the latest World Society of Emergency Surgery guidelines [4].

In the Comparison of Outcomes of Antibiotic Drugs and Appendectomy (CODA) trial, a multicenter randomized controlled trial (RCT) comparing a 10-day antibiotic course with appendectomy (mostly laparoscopic), 414 /1552 included patients had an appendicolith. Overall, antibiotics were shown to be noninferior to surgery regarding the main judgment criteria, the 30-day health status based on the European Quality of Life–5 Dimensions (EQ-5 D) questionnaire [5]. However, patients with an appendicolith treated conservatively were at high risk of complications and 41 % of them underwent surgery by 90 days. The Appendicitis Acuta (APPAC) trial, a multicenter RCT of 530 adult patients without appendicolith randomized to surgery (mostly open appendectomy) or antibiotic therapy, failed to demonstrate noninferiority of the nonoperative strategy but did not show increasing risk of delayed surgery for the patients in the antibiotics group who required appendectomy by 1-year follow-up (27.3 %) [6].

To date, the place of ERAT remains undefined. Most publications originate from China, and this strategy has not been studied in other countries. A few comparative studies with small samples have been published, and a recent review and meta-analysis from Wang et al. suggests that ERAT could reduce operative time and recovery time with fewer complications than laparoscopic appendectomy, despite low quality of methodology for the included studies [7]. Most of the studies had short-term outcomes such as the length of stay or the duration of the procedure. Data on long-term outcomes such as appendicitis recurrence and the need for subsequent appendectomy are sorely lacking. Some well-designed, large, randomized studies are needed to determine the place of ERAT, and regarding the recent advances in the care of acute appendictis, comparative studies versus both surgery and antibiotic therapy without intervention should be carried out. In the study from Kong et al., the seven patients without appendicolith could probably have been treated with antibiotics alone.

The advanced technique using SOC with ERAT is interesting as it might improve outcomes, providing a more accurate evaluation and allowing more tailored treatment, just as cholangioscopy has expanded the diagnosis and therapeutic options in the biliary tract. However, there are some limitations that need to be considered. First, ERAT requires bowel cleansing or enemas, which can cause additional pain for patients. Second, a new indication added to the list of endoscopic emergency procedures requires availability of endoscopists with skills in the new procedure, and ERAT can be tricky for less-experienced on-call physicians, even more so if an SOC is indicated. Compared with appendectomy, ERAT that requires stent placement also implies the need for a further colonoscopy. Conversely, compared with surgery, ERAT can be performed without general anesthesia, as was the case in 80 % of patients in the Kong et al. study. Finally, a cost-effectiveness analysis is essential to determine the role of the strategy in routine practice. Although the cholangioscope is a really expensive device, this could be balanced by a shorter hospital stay, a faster recovery time and return to work, and, compared with “standard” ERAT, fewer reinterventions if clearing of all appendicolith is certain, without stent placement.

To conclude, Kong et al. present an innovative minimally invasive strategy providing targeted treatment for a common condition. ERAT and SOC-ERAT can be considered in the emergency toolbox for the management of uncomplicated acute appendicitis, especially in patients with appendicolith, but further studies are necessary to determine its place compared with antibiotics alone or standard surgery. Would this be the time for Western countries to get started?

Publication History

Article published online:
16 February 2022

• References

• 1 Kong LJ, Liu D, Zhang JY. et al. Digital single-operator cholangioscope for endoscopic retrograde appendicitis therapy. Endoscopy 2022; 54: 396-400
• 2 Liu BR, Song JT, Han FY. et al. Endoscopic retrograde appendicitis therapy: a pilot minimally invasive technique (with videos). Gastrointest Endosc 2012; 76: 862-866
• 3 Jaschinski T, Mosch CG, Eikermann M. et al. Laparoscopic versus open surgery for suspected appendicitis. Cochrane Database Syst Rev 2018; 11: CD001546
• 4 Di Saverio S, Podda M, De Simone B. et al. Diagnosis and treatment of acute appendicitis: 2020 update of the WSES Jerusalem guidelines. World J Emerg Surg 2020; 15: 27
• 5 Flum DR, Davidson GH. The CODA Collaborative. et al. A randomized trial comparing antibiotics with appendectomy for appendicitis. N Engl J Med 2020; 383: 1907-1919
• 6 Salminen P, Paajanen H, Rautio T. et al. Antibiotic therapy vs appendectomy for treatment of uncomplicated acute appendicitis: the APPAC randomized clinical trial. JAMA 2015; 313: 2340-2348
• 7 Wang Y, Sun CY, Liu J. et al. Is endoscopic retrograde appendicitis therapy a better modality for acute uncomplicated appendicitis? A systematic review and meta-analysis. World J Clin Cases 2021; 9: 10208-10221