Beyond biliary causes, fish bone perforation as a rare etiology of recurrent fever in a post-Whipple patient: A case report

Abstract

BACKGROUND

Patients who have undergone pancreaticoduodenectomy (Whipple procedure) often develop complex late complications that may be diagnostically challenging. We report a rare cause of recurrent fever and abdominal pain in such a patient: Fish bone-induced jejunal perforation. This case emphasizes the importance of maintaining suspicion for atypical, non-biliary causes in post-Whipple patients with recurrent symptoms, particularly when conventional tests suggest no biliary obstruction. A thorough linear diagnostic approach and multidisciplinary collaboration are essential. The delay in diagnosis highlights the challenges of interpreting subtle imaging findings and correlating them with clinical symptoms mimicking cholangitis.

CASE SUMMARY

A 55-year-old female with a Whipple procedure history 10 years earlier presented with recurrent fever and severe abdominal pain. An initial extensive workup, including imaging and laboratory tests, was inconclusive. Only after detailed re-evaluation of the computed tomography images revealed a subtle linear hyperdensity and subsequent deep push enteroscopy was an embedded fish bone in the efferent jejunal limb identified and removed endoscopically.

CONCLUSION

Clinicians should consider gastrointestinal foreign body perforation in the differential diagnosis of recurrent fever and abdominal pain in patients with altered anatomy after Whipple procedure. Critical image review and advanced enteroscopic techniques are invaluable for diagnosing obscure causes in complex cases.

Key Words: Pancreaticoduodenectomy; Fish bone perforation; Cholangitis; Post-surgical complications; Case report

Core Tip: This case highlights the importance of considering atypical causes like gastrointestinal foreign body perforation in patients with altered postoperative anatomy presenting with recurrent fever and abdominal pain. Despite extensive workup, the cause remained elusive until deep push enteroscopy identified an embedded fish bone in the efferent jejunal limb of a post-Whipple patient. This was only possible after a thorough review of the computed tomography imaging, which showed a subtle linear hyperdensity. This case demonstrates the value of critical image review and advanced endoscopic techniques in diagnosing obscure gastrointestinal pathology in complex post-surgical patients.

INTRODUCTION

Pancreaticoduodenectomy, commonly referred to as the Whipple procedure, is frequently performed to address neoplastic or premalignant conditions of the pancreas and periampullary regions. Despite favorable long-term outcomes, patients may experience late-onset complications such as hepaticojejunostomy strictures, cholangitis, or intrahepatic lithiasis, which can pose diagnostic challenges, particularly in the context of surgically altered anatomy[1,2]. Hepaticojejunostomy strictures are particularly challenging because of the limitations of endoscopic techniques and often necessitate multiple percutaneous cholangiography procedures. Commonly employed methods for managing postoperative anastomotic strictures include balloon or bougie dilatation, which is successful in approximately 70% of cases (ref). However, the introduction of biodegradable stents has significantly improved the treatment outcomes. A case report by Elsayed et al[3] demonstrated a successful outcome with biodegradable hepaticojejunostomy stenting, further confirming the favorable outcomes of this novel approach in terms of stent patency and reduction of recurrent cholangitis. Identifying the cause of recurring abdominal pain and fever in these patients often raises questions regarding the patency of the hepaticojejunostomy anastomosis. However, a comprehensive diagnostic approach and collaboration across multiple medical disciplines are essential, as other unusual causes can lead to similar symptoms[4]. We report a rare case of a 55-year-old woman with a history of Whipple procedure for side-branch intraductal papillary mucinous neoplasm in the head of the pancreas, who presented nearly a decade later with recurrent febrile episodes and severe abdominal pain. Despite extensive work-up, including multiple imaging modalities and laboratory evaluations, the cause remained elusive until deep push enteroscopy identified an embedded fish bone in the efferent limb of the jejunum. This was only possible after a thorough review of recent images [computed tomography (CT) scan], which demonstrated a subtle hyperenhancing linear shadow penetrating the small bowel loops into the mesenteric structures (Figure 1). This case underscores the importance of considering atypical causes, such as gastrointestinal foreign body perforation, in patients with altered postoperative anatomy and non-specific symptoms. However, this report focuses on a rare non-biliary cause of recurrent fever and abdominal pain, fish bone perforation in the efferent jejunal limb, rather than biliary strictures or their management.

Figure 1 Computed tomography kidneys, ureters, and bladder showing a linear hyperdense structure traversing the efferent jejunal limb near the right renal vein.

CASE PRESENTATION

Chief complaints

Fever and severe abdominal pain.

History of present illness

Recurrent fever up to 39 °C, severe abdominal pain, and progressive weight loss over the past year. These symptoms have developed gradually and are causing significant concern, potentially indicating a complication related to her previous pancreatic surgery or a recurrence of her original condition.

History of past illness

Whipple surgery in 2015.

Personal and family history

No family history of a similar condition. No other clinical history.

Physical examination

Apart from abdominal pain, surgical scars of the previous surgeries and recorded high temperatures, nothing else was remarkable.

Laboratory examinations

The results of the laboratory examinations indicate cholangitis, Table 1.

Table 1 Blood tests throughout the clinical review.

Test parameter	Reference range	January 25, 2025	March 24, 2025	April 28, 2025
AST (SGOT)	0-35 U/L	51	21	29.60
ALT (SGPT)	0-45 U/L	45	38	32.90
ALP	30-120 U/L	83	21	99
Total bilirubin	> 21 (μmol/L)	5	8	4.55
Direct bilirubin	> 7 (μmol/L)	2	3	1.68
Albumin	40-60 g/L	47	46	43.20
Total protein	64-83 g/L	76	80	85.700

ALP: Alkaline phosphatase; AST: Aspartate aminotransferase; ALT: Alanine aminotransferase; SGOT: Serum glutamic-oxaloacetic transaminase; SGPT: Serum glutamic-pyruvic transaminase.

Imaging examinations

Magnetic resonance cholangiopancreatography (MRCP) showed no hepatico-jejunostomy stricture or biliary dilatation but revealed a 37-mm linear filling defect in the right intrahepatic duct, initially suspected as intrahepatic lithiasis. Percutaneous transhepatic cholangiography was planned but abandoned after ultrasound revealed no ductal dilation. An incidental right hydronephrosis prompted CT kidneys, ureters, and bladder (KUB), which, upon careful second review, demonstrated a subtle, linear hyperdense structure traversing the efferent jejunal limb toward the right renal vein, consistent with a fish bone (Figure 1). This clarified the previously ambiguous intrahepatic filling defect, which likely represented inflammatory changes secondary to jejunal perforation. Deep push enteroscopy using an Olympus PCFPH190 L pediatric colonoscope revealed a fish bone deeply embedded in the jejunal wall of the efferent limb (Figure 2A). The specimen was meticulously extracted intact using biopsy forceps (Figure 2B and C) (Video).

Figure 2 Showing endoscopic pictures of the fish-bone. A: Endoscopic view of the fish bone penetrating the jejunal wall; B: Extraction of fish bones using biopsy forceps; C: Extracted intact fishbone.

FINAL DIAGNOSIS

Recurrent cholangitis due to a fishbone perforation.

TREATMENT

Endoscopic extraction of the fishbone and intravenous antibiotics.

OUTCOME AND FOLLOW-UP

Intravenous piperacillin-tazobactam was administered. The patient markedly improved with resolution of fever and abdominal pain. Subsequent outpatient follow-up demonstrated stable recovery with no further complications.

DISCUSSION

The present case illustrates the complexities involved in diagnosing recurrent abdominal pain and infection in individuals with altered gastrointestinal anatomy following extensive hepatopancreatobiliary surgical procedures. Nearly a decade later, she experienced recurrent episodes of abdominal pain radiating posteriorly, accompanied by low-grade fever and bacteremia.

The delay in diagnosis can be attributed to several factors. First, the non-specific symptoms mimicked those of a biliary tract infection (cholangitis), which is a common post-Whipple complication. This similarity in presentation led to an initial misdiagnosis and delayed identification of the true cause. Second, normal liver function test results contradicted the clinical suspicion of biliary obstruction, leading to diagnostic uncertainty. This discrepancy between the clinical presentation and laboratory findings further complicates the diagnostic process.

The initial imaging interpretation focused on biliary pathology, overlooking subtle signs of gastrointestinal foreign bodies. The linear filling defect on MRCP was misinterpreted as intrahepatic lithiasis instead of localized inflammation and fistulization caused by a penetrating fish bone. This misinterpretation highlights the importance of considering non-biliary causes in patients with persistent symptoms, despite normal liver test results.

The pathophysiology linking jejunal perforation to the clinical picture provides insight into the patient presentation. The embedded fish bone caused localized perforation in the efferent jejunal limb with adjacent inflammation. This likely resulted in bacterial translocation, causing recurrent episodes of low-grade bacteremia and fever, clinically mimicking cholangitis. These inflammatory changes led to a pseudo-filling defect in the right intrahepatic duct due to extrinsic compression or inflammatory infiltration, accounting for the ambiguous imaging signs.

Lin et al[5] emphasized that "such complications may manifest months to years post-operatively and are often challenging to identify in the early stages due to their non-specific or intermittent nature". Recently, Kihara et al[6] highlighted that late postoperative cholangitis can develop even in the absence of strictures and may present with vague recurrent febrile episodes, further complicating the diagnosis.

The eventual discovery and extraction of a fish bone during enteroscopy, following an intensive review of recent imaging, was exceptionally useful in this case. This foreign object was located deeply embedded within the small bowel wall of the efferent limb, presumably inducing localized inflammation and contributing to recurrent episodes of bacteremia. Goh et al. reviewed a cohort of patients who experienced gastrointestinal perforations secondary to ingested foreign objects, "noting that fish bones were among the most frequently reported culprits"[7].

This case shows several important clinical implications. Maintaining a high index of suspicion for non-biliary causes is crucial when postoperative patients exhibit normal liver test results but persistent symptoms. A critical re-evaluation of imaging by experienced radiologists is necessary, especially in patients with anatomical alterations. Advanced endoscopic techniques, such as deep push enteroscopy, enable direct visualization and therapeutic interventions in challenging cases. Finally, multidisciplinary teamwork among gastroenterology, radiology, and surgery enhances diagnostic accuracy.

Successful endoscopic extraction resulted in clinical improvement, suggesting that the foreign body played a more pivotal role in her clinical presentation than initially presumed. This case highlights the efficacy of deep enteroscopy techniques and critical image reviews in cases of altered anatomy, leading to the identification of a non-biliary source of infection in complex postoperative scenarios. Balloon-assisted and double-balloon enteroscopy approaches have been shown to significantly enhance the diagnostic and therapeutic capabilities in patients with surgically altered gastrointestinal anatomy[8].

CONCLUSION

Our case emphasizes that, beyond common biliary complications, rare causes such as gastrointestinal foreign body perforations must be considered in post-Whipple patients with recurrent fever and abdominal pain. Meticulous imaging reviews and the utilization of advanced endoscopic techniques are indispensable. This case reinforces the importance of a broad differential diagnosis, early multidisciplinary evaluation, and vigilance for subtle imaging signs to avoid delayed diagnosis and optimize patient outcomes.