Endoscopic retrograde appendicitis therapy combined with electrohydraulic lithotripsy for stump appendicitis with abscess and fecalith: A case report

Abstract

BACKGROUND

Stump appendicitis is a rare long-term complication after appendectomy. When complicated by intra-abdominal abscess and giant fecalith impaction, conventional treatment relies on secondary surgery, which is technically challenging and carries a high risk. Endoscopic retrograde appendicitis treatment (ERAT) and electrohydraulic lithotripsy (EHL) offer a novel minimally invasive option for such complex cases.

CASE SUMMARY

We report the case of a 42-year-old woman who presented with a 15-day history of right lower abdominal pain 8 years after appendectomy. Physical examination revealed right lower quadrant tenderness, and routine blood tests showed mild elevations in white blood cell count, neutrophil percentage, and procalcitonin levels. Abdominal computed tomography revealed stump appendicitis with intra-abdominal abscess and a giant impacted fecalith within the abscess cavity. Following the failure of anti-infective therapy, the patient underwent cholangioscope-assisted ERAT combined with EHL after providing informed consent. During the procedure, a large amount of purulent discharge was observed at the appendiceal orifice. The cholangioscopy was advanced into the residual appendiceal lumen and the adjacent abscess cavity, confirming giant fecalith impaction. Repeated attempts at basket extraction failed, and EHL was subsequently used to fragment the giant fecalith, followed by piecemeal basket retrieval. A plastic biliary stent was deployed for internal drainage. The patient experienced marked relief of abdominal pain. Two months later, the stent was removed, and the remaining fecalith fragments were completely retrieved. No recurrence has been observed to date.

CONCLUSION

For stump appendicitis complicated by intra-abdominal abscess and giant fecalith impaction, ERAT combined with EHL may be a safe, effective, and feasible minimally invasive treatment alternative.

Key Words: Endoscopic retrograde; Electrohydraulic lithotripsy; Stump appendicitis; Abscess; Fecalith; Case report

Core Tip: This case reports the first use of endoscopic retrograde appendicitis treatment combined with electrohydraulic lithotripsy for stump appendicitis complicated by intra-abdominal abscess and giant fecalith impaction. Under cholangioscopic guidance, endoscopic retrograde appendicitis treatment combined with electrohydraulic lithotripsy enabled fecalith removal and internal stent drainage, avoiding high-risk secondary surgery. This innovative endoscopic strategy provides a novel, minimally invasive option, with the key benefit of avoiding highrisk reoperation.

INTRODUCTION

Stump appendicitis is a rare long-term complication following appendectomy, with an incidence of approximately 1 in 50000[1]. However, stump appendicitis complicated by intra-abdominal abscess and giant fecalith impaction is exceedingly rare, and its optimal management remains undefined. When such abscesses occur, conventional treatment typically relies on surgical intervention, including open or laparoscopic abscess debridement, drainage, and stump removal[2]. However, secondary surgery is not only technically more challenging but also carries risks of intestinal adhesions, bowel injury, incision infection, and prolonged postoperative recovery[2].

As a minimally invasive technique, endoscopic retrograde appendicitis treatment (ERAT) has been widely adopted for acute uncomplicated appendicitis due to its advantages of noninvasiveness, rapid recovery, and preservation of intestinal anatomy[3,4]. In recent years, several studies have reported that ERAT can effectively manage selected cases of periappendiceal abscess, thereby avoiding surgery[5,6]. Nevertheless, no published reports have described the use of ERAT for stump appendicitis accompanied by intra-abdominal abscess and giant fecalith impaction, and evidence regarding electrohydraulic lithotripsy (EHL) for appendiceal fecaliths remains lacking.

Here, we report a 42-year-old woman diagnosed with stump appendicitis complicated by intra-abdominal abscess and giant fecalith impaction 8 years after appendectomy. After the failure of anti-infective therapy, she underwent choledochoscope-assisted ERAT combined with EHL. Successful lithotripsy enabled fecalith removal and placement of a plastic biliary stent for internal drainage of the abscess, avoiding repeat surgery.

CASE PRESENTATION

Chief complaints

A 42-year-old woman was admitted to our hospital with a 15-day history of right lower abdominal pain.

History of present illness

The abdominal pain was characterized by a persistent dull ache. The patient presented to the Department of Gastrointestinal Surgery and was diagnosed with stump appendicitis. Following anti-infective treatment, the symptoms improved but subsequently recurred.

History of past illness

The patient underwent an appendectomy for acute appendicitis 8 years ago.

Personal and family history

The patient’s personal and family history was unremarkable.

Physical examination

The patient’s vital signs were stable. Physical examination revealed right lower quadrant tenderness, without rebound tenderness or guarding.

Laboratory examinations

Routine blood tests showed mild elevations in white blood cell count, neutrophil percentage, and procalcitonin levels.

Imaging examinations

Abdominal computed tomography (CT) revealed poor delineation of the appendix, with associated thickening of the adjacent bowel wall, surrounding exudative fluid, and a small amount of gas, suggestive of abscess formation (Figure 1A). Within the abscess cavity, a hyperdense lesion measuring approximately 1.5 cm in diameter was observed, likely representing an impacted appendicolith (Figure 1A).

Figure 1 Representative computed tomography and endoscopic images of the patient across the treatment timeline. A: Abdominal computed tomography revealed an abscess at the appendectomy site, containing a small amount of gas and a giant fecalith; B: Colonoscopy revealed a substantial amount of whitish purulent discharge adherent to the appendiceal orifice; C: Cholangioscopy revealed a large fecalith embedded within an abscess cavity adjacent to the appendiceal stump, and removal of the fecalith using a retrieval basket was unsuccessful; D: The electrohydraulic lithotripter successfully performed fecalith fragmentation; E: Most fragmented fecaliths were removed using a basket; F: A plastic stent was implanted into the abscess cavity; G: Two months later, the stent was removed via colonoscopy; H: Choledochoscopy enabled removal of the remaining few fecaliths, with marked improvement in the absorption of the abscess cavity.

FINAL DIAGNOSIS

Stump appendicitis with intra-abdominal abscess and a giant fecalith impaction.

TREATMENT

Following the failure of anti-infection therapy and the surgeon’s determination that surgical re-intervention was inadvisable, the patient underwent cholangioscope-ERAT combined with EHL after providing informed consent. Because the patient’s appendix had been previously resected, conventional X-ray-assisted ERAT may fail to precisely locate the appendiceal stump, leading to procedural failure. Therefore, we ultimately chose cholangioscope-assisted ERAT, which allows treatment under direct visualization (Video). Colonoscopy revealed a substantial amount of whitish purulent discharge adherent to the appendiceal orifice (Figure 1B). A cholangioscopy was advanced into the residual appendiceal lumen, where the mucosa appeared congested and edematous, and a suspected retained surgical suture was visualized at the blind end. A giant abscess cavity with a narrowed orifice was identified adjacent to the appendiceal stump. Within the abscess cavity, a giant appendicolith was found impacted. Due to the large size and hard consistency of the appendicolith, repeated attempts at fragmentation and retrieval using a basket were unsuccessful (Figure 1C). Subsequently, an EHL probe was introduced into the abscess cavity, and an EHL procedure (OOD mode, energy: 0.4 J) was performed under direct visualization (Figure 1D). The giant appendicolith was successfully fragmented into smaller pieces, most of which were retrieved via repeated basket passes (Figure 1E). A small number of residual stone fragments were intentionally left for planned retrieval in a subsequent procedure. Following thorough irrigation of the abscess cavity, a plastic biliary stent (8.5 Fr, 7 cm) was successfully deployed (Figure 1F).

OUTCOME AND FOLLOW-UP

The patient’s abdominal pain was markedly alleviated, with no recurrence. At the 2-month follow-up, CT demonstrated substantial resolution of the abscess cavity. The appendiceal stent was subsequently removed (Figure 1G), and the cholangioscopy enabled removal of the remaining few fecaliths, with marked improvement in abscess cavity absorption (Figure 1H). Four months after stent removal, the patient has remained free of recurrence.

DISCUSSION

The diagnosis of stump appendicitis was based on the patient’s typical symptoms, along with a history of prior appendectomy and abdominal CT findings. Most cases of stump appendicitis can be effectively managed with anti-infective therapy. However, this case is unique in that stump appendicitis was accompanied by an intra-abdominal abscess and giant fecalith impaction, an extremely rare occurrence in clinical practice[7]. The pathological basis of stump appendicitis is primarily a long residual appendiceal stump resulting from the initial appendectomy, combined with postoperative local anatomical adhesions, which, under chronic inflammatory stimulation, leads to recurrent congestion and edema of the stump mucosa[8]. Based on this pathological substrate, fecalith stagnation and displacement of the intestinal bacterial flora further induce infection of the residual cavity, gradually leading to peripheral exudation, tissue swelling, and ultimately progression to stump appendicitis complicated by abdominal abscess and giant fecalith impaction - exactly as observed in the present case. This constituted the underlying cause of the failure of anti-infective treatment in our patient. Conventional treatment primarily relies on secondary surgery[1]; however, surgical consultation indicated that postoperative intra-abdominal adhesions, anatomical displacement of the bowel, and inflammatory edema would significantly elevate surgical risk, potentially causing injury to the surrounding bowel and ileocecal vessels. Consequently, managing this patient posed a substantial challenge.

ERAT achieves etiological treatment of the preserved appendix primarily through endoscopic irrigation, fecalith removal, drainage, and decompression. Currently, it is mainly indicated for uncomplicated appendicitis, chronic appendicitis, and selected cases of periappendiceal abscess[9,10]. In the present case, ERAT was ultimately adopted for the following reasons. First, from an anatomical and pathological perspective, stump appendicitis with intra-abdominal abscess formation remains fundamentally a condition of appendiceal stump obstruction and infection, thereby providing a logical basis for ERAT. Second, in recent years, choledochoscope-assisted ERAT has enabled precise treatment of appendiceal lesions under direct visualization, which enhances procedural safety[11]. To the best of our knowledge, this case represents the first report of ERAT for stump appendicitis complicated by intra-abdominal abscess. During the procedure, after identifying the appendiceal orifice via colonoscopy, the choledochoscopy was successfully advanced into the residual lumen and the adjacent abscess cavity, allowing detailed assessment of mucosal engorgement of the residual stump, extent of the abscess, and fecalith impaction. This underscores the unique advantage of direct visualization afforded by the choledochoscope. Following confirmation of stenosis at the abscess cavity opening under direct vision, the choledochoscopy was able to traverse the stenotic site, thereby creating favorable conditions for subsequent fecalith extraction and drainage. Importantly, ERAT effectively circumvents the various challenges posed by surgical re-intervention. By accessing the appendiceal stump via the natural colonic lumen, it avoids external dissection through postoperative adhesions. Direct cholangioscopic visualization overcomes anatomical displacement, enabling precise navigation into the residual lumen and abscess.

Another innovative aspect of this case is the first reported use of EHL for the management of a large impacted fecalith within the abscess cavity of an appendiceal stump. The fecalith measured 1.5 cm in diameter and was of hard consistency, and repeated attempts at retrieval with a basket were unsuccessful. EHL is well established for endoscopic treatment of pancreaticobiliary stones[12], but its application to appendiceal fecaliths has rarely been reported. Zou et al[13] described the successful use of EHL for appendicitis complicated by a giant appendiceal fecalith, providing preliminary evidence supporting the safety of EHL in uncomplicated appendicitis. In the present case, EHL was combined with ERAT to achieve precise fragmentation of the giant impacted fecalith within the lumen of the appendiceal stump abscess under direct visualization, without complications such as perforation or bleeding, thereby demonstrating favorable safety and efficacy. Key technical points included reducing the pump pressure to ensure fluid filling of the abscess cavity, initiating lithotripsy with low energy, contacting the tip of the electrohydraulic probe with the fecalith under direct vision while avoiding the mucosa, and performing piecemeal basket retrieval after fragmentation.

Given the prolonged endoscopic procedural time, a staged fecalith extraction strategy was adopted to ensure safety. After removal of most of the impacted fecalith via lithotripsy, a plastic stent was placed in the abscess cavity to facilitate continuous dilation and drainage. The stent was retained for 2 months and subsequently removed, after which a choledochoscopy was reinserted into the residual cavity to retrieve all remaining fecalith fragments. No recurrence was observed during short-term follow-up, confirming the feasibility and efficacy of this protocol for complex appendiceal stump lesions.

The limitations of this case were as follows. First, this was a single case report, and prospective studies are warranted to verify long-term outcomes. Second, no standardized protocol currently exists for EHL parameters, and further optimization is required to enhance lithotripsy efficiency while minimizing the risk of mucosal injury.

CONCLUSION

For stump appendicitis complicated by intra-abdominal abscess and giant fecalith impaction, ERAT combined with EHL may be a safe, effective, and feasible minimally invasive treatment alternative. Longer-term follow-up is needed to confirm these findings.