Torsion of the gallbladder: a rare but important differential to consider when treating acute cholecystitis non-operatively
- 1 Blacktown Hospital, Blacktown, New South Wales, Australia
- 2 Department of Surgery, Westmead Hospital, Westmead, New South Wales, Australia
- Correspondence to Dr Arun Ahluwalia; arun.ahluwalia@health.nsw.gov.au
Abstract
A 79-year-old woman presented with postprandial epigastric pain. She had normal vital signs, inflammatory markers and liver function tests. Ultrasound and CT of the abdomen demonstrated features consistent with acute cholecystitis. Her medical comorbidities and extensive abdominal surgical history prompted the decision to treat non-operatively. Despite optimal medical management, worsening abdominal pain and uptrending inflammatory markers developed. She underwent an emergency laparoscopy which revealed a necrotic gallbladder secondary to an anticlockwise complete gallbladder torsion; a rare condition associated with significant morbidity and mortality if managed non-operatively. Laparoscopic cholecystectomy was achieved without complication and the patient had an uneventful recovery. Preoperative diagnosis of torsion of the gallbladder is difficult. However, there are certain patient demographics and imaging characteristics that can help surgeons differentiate it from acute cholecystitis; a condition which can be safely managed non-operatively in selected patients. The differentiating features are elaborated on in this case report.
Background
Torsion, or volvulus, of the gallbladder is defined as an axial twisting of the organ on its longitudinal axis causing compromise to its vascular supply.1 2 The exact mechanism is poorly understood but requires a free-floating gallbladder outside of the gallbladder fossa, either sitting on a mesentery or connecting to a cystic duct and artery sitting on a mesentery of its own.3
Torsion of the gallbladder occurs predominantly in a geriatric, female population with a median age of 77 and a female:male ratio of 4:1.4 Gallbladder torsion will lead to eventual ischaemic necrosis, gangrene of the gallbladder, perforation and biliary peritonitis if not promptly diagnosed and operatively managed with an overall mortality rate of 6%.4 Preoperative diagnosis is difficult however due to similarities in imaging and presentation to the more common acute cholecystitis. This is a clinical predicament as many elderly patients with acute cholecystitis are managed conservatively with antibiotics and gut rest rather than urgent surgery. Preoperative diagnosis remains a challenge despite advances in imaging and new modalities with only 26% of cases diagnosed before reaching the operating room.4
Our case involved a 79-year-old woman with suspected acute cholecystitis. The patient deteriorated clinically and biochemically despite optimal conservative management and was promptly taken for emergency laparoscopic cholecystectomy, where an intraoperative diagnosis of gallbladder torsion was made. Despite the rarity of gallbladder torsion as a condition, preoperative diagnosis is achievable and important. Increased clinician awareness of epidemiological risk factors and imaging features may result in earlier diagnosis and reduce delays to operative management. While our patient had an uneventful recovery, there were certain patient characteristics and imaging findings which may have prompted earlier diagnosis and operative intervention.
Case presentation
A 79-year-old female patient presented with a 3-hour history of epigastric pain and peri-umbilical pain radiating to both flanks. The pain started after lunch and was associated with nausea. Bowels had last opened the day previous to presentation and she had been passing flatus. There were no other associated symptoms. The patient had an extensive abdominal surgical history including a diverticular perforation managed with a Hartmann’s operation (subsequently reversed), open appendicectomy, an open right inguinal hernia repair and one adhesional small bowel obstruction that was treated conservatively. She had also had a laparotomy for mesh repair of an incisional hernia which required extensive adhesiolysis. Relevant medical history included atrial fibrillation, right bundle branch block and hypertension. She was therapeutically anticoagulated on apixaban (factor Xa inhibitor). She was a non-smoker, independent with her activities of daily livings and lived at home alone.
Her vital signs were all within normal limits and she had a body mass index (BMI) of 23.5. On examination her abdomen was soft with a tender epigastrium and localised percussion tenderness. Bowel sounds were absent and there was no palpable mass or other abnormality.
Investigations
Initial laboratory blood results were essentially unremarkable with C reactive protein (CRP) <4 mg/L, white cell count (WCC) 8.6×109/L and normal liver function tests. There was a mild acute kidney injury with estimated glomerular filtration rate reduced to 67 mL/min/1.73 m from baseline 90 mL/min/1.73 m.
Due to diagnostic uncertainty, a CT scan was performed with oral and intravenous constrast (portal venous phase). The CT demonstrated findings equivocal for cholecystitis, including a distended gallbladder, minor wall thickening and some adjacent fat stranding (see figure 1). Abdominal ultrasound (US) showed a thickened gallbladder wall of up to 6 mm with focal anterior pericholecystic fluid. There was no identified cholelithiasis and the common bile duct was normal in diameter fot the patients age, measuring 5–6 mm.
Coronal slice of CT scan abdomen demonstrating below the inferior liver border (A) a free-floating gallbladder (B). It is distended, in a transverse lie with minor gallbladder wall thickening.
Differential diagnosis
Given the imaging findings of pericholecystic fluid, gallbladder wall thickening and a lack of identified cholelithiasis, the working diagnosis was acute acalculous cholecystitis. Acalculous cholecystitis represents approximately between 5% and 10% of all acute cholecystitis cases and is associated with higher morbidity and mortality rates as compared with calculous cholecystitis.5 Of note, there was no evidence of pancreatitis with a normal lipase of 74 U/L and normal radiographic appearance of the pancreas.
Treatment
The patient’s therapeutic anticoagulation in conjunction with her medical comorbidities and extensive surgical history contributed to the decision to treat non-operatively with intravenous antibiotics, analgesia and gut rest. On day 3 of admission the patient had symptom of severe 10/10 abdominal pain despite receiving increased doses of analgesia. There was worsening right upper quadrant tenderness with worsening localised peritonism. CRP increased to 138 mg/L and WCC to 18.1×109/L. She remained haemodynamically stable and afebrile.
These clinical and biochemical findings prompted the decision for urgent emergency laparoscopic cholecystectomy. Operative findings included extensive adhesions in the right upper quadrant with an underlying large, distended, dusky and necrotic gallbladder. On further dissection it was clear that the patient had a free-floating gallbladder which had undergone an anticlockwise 3600 torsion (see figure 2.). The axis of rotation was based on the cystic duct and artery within a mesentery of their own, at the level of the inferior liver border.
Laparoscopic view of anticlockwise complete torsion of the gallbladder. The necrotic gallbladder is seen at (A) and the liver at (B). The arrow shows the twisted pedicle of the gallbladder.
The gallbladder was first decompressed using a concord needle and 20 mL of bile-stained fluid was drained. This decompression facilitated safe grasping of the gallbladder and enabled it to be rotated in a clockwise fashion to be detorted. Careful dissection was then performed and a critical view of safety achieved prior to cannulation of the cystic duct and completion of an intraoperative cholangiogram which was normal. A laparoscopic cholecystectomy was then completed in the standard fashion with the only exception being the insertion of a 15 French Blake drain to the gallbladder fossa.
Outcome and follow-up
There were no surgical or anaesthetic complications during the procedure and the patient was transferred to the surgical ward postoperatively. A low-fat diet was tolerated on postoperative day 1 and the drain was removed on postoperative day 2. The patient was medically cleared for discharge on postoperative day 2 but required an additional 2 days of in-hospital physiotherapy. She was discharged on postoperative day 4 with no in-hospital complications. She was subsequently seen in the operating surgeon’s outpatient clinic 6 weeks later. Again, no postoperative issues or complications were identified. Pathology results demonstrated haemorrhagic infarction of the gallbladder with active inflammation consistent with effects secondary to torsion of the gallbladder. There was no histopathological evidence of malignancy.
Discussion
Patients with suspected gallbladder torsion should be taken for urgent operative detorsion and cholecystectomy. Distortion of relevant anatomy secondary to the torsion is common. Careful dissection, often starting at the gallbladder body, is recommended after first detorting the gallbladder in order to avoid extrahepatic biliary duct iatrogenic injury.6 The first laparoscopic cholecystectomy for an acute gallbladder torsion was performed in in 1994.4 On review of the literature, including search terms for both gallbladder volvulus and torsion, only 61 cases of treatment with laparoscopic cholecystectomy have been reported. Due to the rarity of gallbladder torsion and subsequent difficulties in recruitment, it has proved difficult to produce randomised control trials or large group studies that compare laparoscopic to open cholecystectomy approaches. Although, small cohort studies and numerous case reports have shown favourable surgical outcomes in those treated with laparoscopic cholecystectomy and conclude that this is a safe and feasible treatment.6 7 Delays in diagnosis may mandate open cholecystectomy due to the sequelae of gallbladder necrosis; such as perforation, billious peritonitis and haemodynamic instability.6 The first case of robotic surgical management of gallbladder torsion involving the use of Indocyanine Green (ICG) fluorescence to identify biliary structures was reported in 2019 and had a favourable outcome.8
Only 26% of patients with gallbladder torsion receive an accurate diagnosis based on clinical and imaging findings before reaching the operating room.4 For the remainder of cases, the most common working diagnosis is acute cholecystitis. A diagnostic dilemma remains for the majority of cases in which this misdiagnosis occurs as emergency cholecystectomy may not be prioritised. This is especially true for the geriatric population, of which gallbladder torsion primarily effects, whereby non-operative management is common due to the more likely presence of medical comorbidities and higher anaesthetic risk. This was the case for our patient, and as such the patient failed to show serological or clinical improvement despite optimal medical management, which is a principal feature of gallbladder torsion.6 Delay to operative detorsion results in progression of gallbladder wall necrosis to gangrene, perforation and biliary peritonitis with subsequent clinical deterioration. Mortality and morbidity are therefore lower in those diagnosed early.4 Torsion of the gallbladder involves an overall mortality rate of approximately 6% usually occurring in the elderly population with multiple comorbidities.4 With increased clinician awareness of the pathophysiology, epidemiological risk factors and imaging findings associated with gallbladder torsion, higher rates of preoperative diagnosis and resultingly lower mortality and morbidity can be achieved.
For torsion of the gallbladder to occur, certain anatomical variants must be present. Notably the gallbladder has to be free floating outside of the gallbladder fossa of the liver dependant on a mesentery that connects it to the inferior surface of the liver. Such variations are estimated to occur in only 5% of the population.9 Gross described a classification of free-floating gallbladders into type I and type II. Type I involves the gallbladder sitting on a mesentery of its own. A type II free-floating gallbladder involves only the cystic duct and artery attached to a mesentery with the gallbladder dependant on this attachment.3 This case demonstrates torsion in a type II free-floating gallbladder.
In addition to the anatomical variations mentioned above, there are various factors that then lead to increased chance of twisting and subsequent torsion. With increasing age comes the loss of visceral fat and elastic tissue and in many cases liver atrophy. This exacerbates the mobility of the gallbladder and is thought to explain the increased incidence of gallbladder torsion in the elderly.1 Low BMI is thought to similarly contribute through decreasing visceral fat. Kyphoscoliosis is thought to place the gallbladder in a more dependant and thus vulnerable position to twist. It is also postulated that atherosclerosis, with subsequent hardening of the cystic artery, as well as a tortuous cystic duct provides a firmer axis for the gallbladder to twist on.1 6 Clinicians should keep a higher suspicion for gallbladder torsion for patients with multiple of the following risk factors: geriatric, female, low BMI, kyphoscoliosis and atherosclerosis.
A major factor in the mechanism of twisting itself is thought to be peristalsis of neighbouring organs. Clockwise rotation may be secondary to duodenal and gastric peristalsis while anti-clockwise rotation from peristalsis of the transverse colon. This can cause incomplete torsion defined as <1800 and complete torsion which is defined as >1800.1 4 In cases reported that describe the direction of torsion, clockwise rotation occurred approximately 53% of the time with anticlockwise rotation occurring the remaining 47% of the time. There has been no demonstrated relationship between direction of torsion and whether it was an incomplete or complete torsion.4
US and CT abdomen are the most common imaging modalities used in the workup of gallbladder torsion. Gallstones have been found to be present in approximately 32% of reported cases.4 As such, imaging showing inflammation of a free-floating gallbladder without presence of gallstones should raise suspicion of gallbladder torsion.
The sonographic findings of a distended gallbladder with hyperechoic wall thickening are common but are non-specific in differentiating from acute cholecystitis. More specific findings include a gallbladder free from its fossa and inferior to the liver, transverse orientation and a conical structure connecting the gallbladder to the liver representing the twisted pedicle.10 These specific features were not appreciable for our patient in both the report and through retrospective analysis.
On CT abdomen, findings that are non-specific in differentiating acute cholecystitis from gallbladder torsion include features of gallbladder wall inflammation, fluid collection in the gallbladder fossa and a hyperenhancing cystic duct on the right of the gallbladder. More specific findings include the abrupt angulation of the gallbladder neck as a ‘beak’ sign, twisting of the vascular pedicle on a post contrast study as a ‘swirl’ sign and a gallbladder in a transverse lie free from the gallbladder fossa.11 Our patient’s CT had reported minor gallbladder wall thickening with some surrounding fat stranding. However, retrospective analysis showed a gallbladder which was free floating out of its fossa and in a transverse lie (see figure 1). The identification of such features may have helped make torsion a more likely preoperative diagnosis.
Magnetic resonance cholangiopancreatography (MRCP) has been found to be useful as a supplement or alternative imaging modality. Findings may show a V shaped distortion of extrahepatic bile ducts, a twisted cystic duct, distended and enlarged gallbladder deviated to midline and different intensities of gallbladder wall, extrahepatic ducts and cystic ducts. MRI is very useful for detecting gallbladder wall necrosis.12–14 Hepatobiliary iminodiacetic acid (HIDA) scintigraphy has also been reported to be a useful diagnostic tool showing exclusion of the gallbladder and in some cases a characteristic bullseye sign representing cystic duct obstruction.1 15
In order to avoid misdiagnosis, we recommend surgeons carefully consider patients that have risk factors for gallbladder torsion. This specifically includes geriatric females with low BMI or kyphoscoliosis.
Careful review of CT and US imaging for a free-floating gallbladder out of the gallbladder fossa, transverse lie of the gallbladder and a ‘beak’ or ‘swirl’ sign should be conducted. If there remains diagnostic doubt then further imaging with MRCP or HIDA scintigraphy may be of use. As misdiagnosis is not always avoidable, a lack of clinical or biochemical improvement despite optimal medical management should prompt surgical intervention before consequences such as perforation, biliary peritonitis and haemodynamic instability develop.
Patient’s perspective
I was in the most pain I had ever experienced the night before and the day of my operation. But I was surprised and relieved by how little pain I had immediately after my surgery. My recovery was much faster than my previous surgeries which had not been laparoscopic.
Learning points
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Epidemiological and patient risk factors include: geriatric population, female, low body mass index and kyphoscoliosis.
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Imaging findings important in the diagnosis of gallbladder torsion include: a transverse lie of the gallbladder, free-floating gallbladder out of the gallbladder fossa beneath the inferior liver, a ‘swirl’ or ‘beak’ sign on CT, a V shaped distortion of extrahepatic vessels on magnetic resonance cholangiopancreatography or a ‘bullseye’ sign on Hepatobiliary iminodiacetic acid (HIDA) scintigraphy.
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While there is currently no ‘gold standard’ operative approach, laparoscopic cholecystectomy has been shown to be both safe and effective.
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If torsion of the gallbladder is suspected, prompt operative intervention is required in order to avoid the imminent complications of gallbladder wall necrosis, gangrene, perforation and biliary peritonitis.
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With a diagnosis of a patient with acute cholecystitis in a population meeting epidemiological factors and risk factors for gallbladder torsion, a clinician should keep a low index of suspicion for torsion of the gallbladder and closely monitor for lack of improvement biochemically or clinically despite optimal medical management.
Acknowledgments
We would like to acknowledge Dr George Larcos (Clinical Associate Professor of Medical Imaging, Westmead Clinical School) who contributed to retrospective analysis of radiological imaging presented in this case report.
Footnotes
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Contributors AA is the guarantor for the completed case report. He involved in planning the case report, literature search, writing of the report and editing the report. He involved in obtaining patient consent. MGRA was involved in writing and planning the case report, literature search and editing the case report. He was involved with in hospital management of the case. SG was involved with writing, editing the case report and the literature search. RJC was involved with writing and editing the case report. He was directly involved with the in hospital management of the case including the patients operation and peri-operative treatment.
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Funding The authors have not declared a specific grant for this research from any funding agency in the public, commercial or not-for-profit sectors.
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Competing interests None declared.
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Patient consent for publication Obtained.
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Provenance and peer review Not commissioned; externally peer reviewed.
- © BMJ Publishing Group Limited 2020. No commercial re-use. See rights and permissions. Published by BMJ.
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