Gallbladder volvulus, or torsion of the gallbladder, is a condition in which the organ twists on its long axis to the point where its vascular supply is compromised.[1, 2, 3] First recognized in the late 19th century, this condition remains a rare entity that seldom is diagnosed preoperatively.[4] It is encountered most frequently in patients who are fragile and elderly. A delay in the diagnosis and treatment of gallbladder volvulus may result in life-threatening consequences.[5]
Torsion of the gallbladder should be treated by means of prompt cholecystectomy. Operative intervention is necessary to avoid a fatal outcome due to nonresected gallbladder volvulus.
Torsion of the gallbladder can be complete (ie, >180º) or incomplete (ie, <180º). Complete torsion of a mobile gallbladder on its pedicle interferes with the blood supply to the organ, and if this condition is unrelieved, gangrene develops.
Two anatomic variants of the gallbladder might undergo torsion. In one type, the gallbladder has a mesentery that is prone to torsion.[6] In the other type, the mesentery supports only the cystic duct, allowing a completely peritonealized gallbladder to hang freely. Intermediate forms with a partial mesentery of the gallbladder and a mesentery of the cystic duct also are described.
In adults, a mesentery of the gallbladder can be acquired. The more frequent occurrence of torsion in elderly persons may be explained by the loss of fat and the atrophy of the tissues that may occur with advancing age, leaving the gallbladder hanging freely.
The precipitating factors for the final event of torsion have been cited as follows:
The role of gallstones is debatable. Approximately 20-33% of patients with torsion have gallstones.
Intense peristalsis of the stomach or the duodenum has been implicated in clockwise rotation, whereas the transverse colon is implicated in counterclockwise rotation.
Between 1898, when Wendell first described gallbladder volvulus, and the early 21st century, only about 300 cases of gallbladder torsion were reported. Since the first few years of the 21st century, however, the incidence appears to have increased, possibly because of an increase in life expectancy. As of 2014, about 500 cases had been reported.[4] The peak incidence of gallbladder volvulus occurs in persons aged 65-75 years; 84% of patients are elderly women.
Morbidity and mortality reportedly are low among cases of gallbladder torsion that have been diagnosed and treated early.[7] Delayed or missed diagnosis and treatment increase patient mortality.
The clinical features of gallbladder volvulus can be grouped into three triads, as follows[6] :
Incomplete torsion usually is associated with recurrent episodes of slowly progressive pain, whereas complete torsion has an acute presentation.
At the beginning of the presentation, the white blood cell (WBC) count invariably is within the reference range, but as vascular compromise develops and gangrene sets in, the WBC count climbs to abnormal values.[6]
The results of liver function tests usually are normal because the common bile duct (CBD) is not obstructed; however, patients may have some mild increases in these values.[6]
A preoperative diagnosis can be made by means of imaging techniques (eg, ultrasonography [US] or computed tomography [CT][8, 9] ).
US appears to be the most reliable diagnostic imaging modality in this setting. A large, anteriorly floating gallbladder without gallstones and a conical appearance of the neck with discontinuity of the lumen suggest torsion. Thumbprinting of the gallbladder wall is an indirect sign of a gangrenous process. Nonspecific findings of gross wall thickening, gallbladder distention, and absence of calculi can be present in torsion and in calculus cholecystitis. The so-called cystic duct knot sign has been suggested as a potentially useful ultrasonographic sign for identifying gallbladder volvulus preoperatively.[10]
A floating gallbladder sign (ie, a large, anteriorly floating gallbladder without gallstones) on US or CT is observed most commonly in patients with torsion of the gallbladder.[11] Whirl sign from gallbladder torsion has been found on contrast-enhanced multidetector CT scans.[12]
Depending on the degree of torsion, a hepatoiminodiacetic acid (HIDA) scan may aid in visualizing the gallbladder.[13] The scintigraphic appearance of gallbladder torsion includes a bull's eye and a fusiform CBD as a result of the superimposed floating gallbladder apposed against the anterior abdominal wall.
Magnetic resonance cholangiopancreatography (MRCP) may be useful in diagnosing gallbladder torsion.[14] MRCP can show a V-shaped distortion of the extrahepatic bile ducts due to traction by the cystic duct, tapering and twisting interruption of the cystic duct, a distended gallbladder, and a difference in intensity between the gallbladder and extrahepatic bile ducts and the cystic duct. Diffusion-weighted magnetic resonance imaging (MRI) may help rule out a malignant process.[15]
Findings consistent with an acute hemorrhagic infarct are present in gallbladder volvulus.
Gallbladder volvulus, or torsion of the gallbladder, should be treated with prompt cholecystectomy. Laparoscopic cholecystectomy is feasible and safe in the treatment of gallbladder volvulus, allowing a faster patient recovery and a shorter hospital stay than open cholecystectomy does.[16, 17, 18]
Preoperative diagnosis of gallbladder torsion usually is difficult.[6] The most important differential diagnosis is acute cholecystitis. Advances in diagnostic imaging, chiefly abdominal ultrasonography and computed tomography (see Workup), have been accompanied by increases in the number of cases reported to have been diagnosed preoperatively.
Evacuation of the gallbladder may be necessary to allow grasping with instruments. Detorsion of the gallbladder must be accomplished first. This avoids tenting of and possible injury to the common bile duct (CBD).
The CBD may be injured during ligation of the cystic duct.[19] The twisted gallbladder can tent the CBD, making it vulnerable to injury.