Normal values for sincalide cholescintigraphy: comparison of two methods

Sincalide-Stimulated Cholescintigraphy: A Retrospective Study and Proposal of a Modified Workflow

PURPOSE

Current guidelines for sincalide-stimulated cholescintigraphy (SSC) call for a 60-minute sincalide infusion, and a gallbladder ejection fraction (GBEF) ≥38% is considered normal. In this retrospective study, we hypothesize that most patients reach a normal GBEF by 30 minutes.

METHODS

Eligible patients had undergone a 60-minute SSC from January to December 2019. The clinical SSC data were previously processed on a Xeleris workstation (GE Healthcare). In subjects with GBEF ≥38% based on standard SSC, the GBEF at 20 minutes and 30 minutes were retrospectively calculated using manual pixel height measurements. Receiving operating characteristic was analyzed to determine the best GBEF cutoff at 30 minutes.

RESULTS

Of 302 subjects, mean age of 46 ± 17 years, 33 (10.9%) showed an abnormal GBEF <38% suggestive of functional gallbladder disorder. In the remaining 269 patients (89.1%) with a normal GBEF, 60.6% and 86.6% reached a normal GBEF at 20 minutes and 30 minutes, respectively. Moreover, a GBEF threshold >29.1% at 30 minutes was associated with a negative predictive value of 99.6%, indicating that a 60-minute SSC was not necessary. The GBEF values were not associated with sex, age, patient symptoms, or type of referral. Manually calculated GBEFs on the time-activity curve showed excellent correlation with the primary values. We propose a modified workflow that splits the 60-minute SSC into two 30-minute image sets to allow for a screening GBEF at 30 minutes. If GBEF is >29.1% at 30 minutes, the second image set may be stopped, and the examination is complete.

CONCLUSIONS

The majority of patients (77.2%) undergoing the standard 60-minute SSC reach a normal GBEF already by 30 minutes. The proposed workflow shortens the SCC procedure by 30 minutes, while maintaining high diagnostic accuracy and contributing to improved procedure efficiency and reduced patient discomfort as well as symptoms.

Optimal hepatobiliary scintigraphy for gallbladder dyskinesia

Background

The accuracy of hepatobiliary scintigraphy to assess gallbladder function remains controversial. National supply shortages of pharmaceutical-grade cholecystokinin led to the use of an oral fatty meal to stimulate gallbladder contraction during hepatobiliary scintigraphy. The goal of this study was to compare the predictive indices of cholecystokinin and fatty meal ingestion for stimulation of gallbladder contraction.

Methods

Patients evaluated with hepatobiliary iminodiacetic acid scan from 2014 to 2017 were reviewed and grouped based on testing stimulant (fatty meal versus cholecystokinin). Patients who later underwent cholecystectomy were selected for analysis. Hepatobiliary iminodiacetic acid results were correlated with surgical pathology and postoperative resolution of symptoms. Two-way statistical analysis was performed.

Results

A total of 359 patients underwent hepatobiliary iminodiacetic acid scan followed by cholecystectomy for biliary dyskinesia. Patients who received fatty meal stimulant (n = 86) were compared to those that received cholecystokinin (n = 273). Mean gallbladder ejection fraction during hepatobiliary iminodiacetic acid was 38% and 44% for the cholecystokinin and fatty meal groups, respectively, P = .073. Predictive metrics were not statistically different between groups with regard to pathology, symptomatic improvement, or accuracy. Symptomatic resolution (cholecystokinin–hepatobiliary iminodiacetic acid 78%, fatty meal–hepatobiliary iminodiacetic acid 68%; P = 0.058) and specificity (cholecystokinin–hepatobiliary iminodiacetic acid 26%, fatty meal–hepatobiliary iminodiacetic acid 44%, P = 0.417) were comparable in both testing groups.

Conclusion

Stimulation of gallbladder contraction with a fatty meal during hepatobiliary iminodiacetic acid testing is a more affordable and reliable alternative to cholecystokinin for patients undergoing evaluation for gallbladder dysmotility.

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Use of a fatty meal as a stimulant for hepatobiliary iminodiacetic acid scan.

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Affordable alternative to cholecystokinin for a hepatobiliary iminodiacetic acid scan.

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Comparison of 2 stimulants used for hepatobiliary iminodiacetic acid scan.

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Reliable alternative to IV cholecystokinin for hepatobiliary iminodiacetic acid scans.

Sincalide: A Review of Clinical Utility, Proper Infusion Methodology, and Alternative Cholecystogogues

Sincalide (Kinevac) is widely used in conjunction with cholescintigraphy for a variety of clinical indications. Over the years, numerous publications have verified the optimal infusion methodology. Published data and consensus recommendations emphasize that sincalide, 0.02 μg/kg, should be infused over 60 min. Production problems sometimes limit the availability of sincalide. In that case, non-Food and Drug Administration pharmacy-compounded sincalide may serve as an alternative. Fatty meals have also been used. Various illnesses and drugs may inhibit gallbladder contraction. Thus, these drugs should be withheld for 48 h before the study. Sincalide cholescintigraphy is most commonly used to diagnose or exclude chronic acalculous gallbladder disease. The study should preferably be performed as an outpatient procedure.

Prospective study on changes in the donor gallbladder contraction function after left lateral lobe hepatectomy

This study aimed to evaluate the feasibility of donor gallbladder preservation in liver transplantation. Conventional removal of the donor gallbladder is applied in a majority of pediatric liver transplantation. A total of 42 donors who underwent gallbladder preservation in liver transplantation from October 2013 to December 2015 at the Beijing Friendship Hospital, China, were enrolled for the study. The changes in gallbladder volume and the gallbladder EF of donors before and after surgery were measured through ultrasound, and the changes in the donor gallbladder contraction function before and after surgery were evaluated to help verify the feasibility of gallbladder preservation in living donor left lateral lobe hepatectomy. The gallbladder emptying index dropped to 42.67% in 2 weeks after surgery and gradually increased with the length of recovery time, which could reach 69.14% in 3 months after surgery. At that time, 97.6% of the donors were considered to have recovered their gallbladder contraction function. The gallbladder contraction function at an early stage after gallbladder preservation in liver transplantation is not obviously improved, but it can recover to a normal level in 1 month after surgery, indicating that the gallbladder preservation in hepatectomy of living donor can effectively guarantee the gallbladder contraction function.

Decision-making patterns in managing children with suspected biliary dyskinesia

AIM

To explore and to analyze the patterns in decision-making by pediatric gastroenterologists in managing a child with a suspected diagnosis of functional gallbladder disorder (FGBD).

METHODS

The questionnaire survey included a case history with right upper quadrant pain and was sent to pediatric gastroenterologists worldwide via an internet list server called the PEDGI Bulletin Board.

RESULTS

Differences in decision-making among respondents in managing this case were observed at each level of investigations and management. Cholecystokinin-scintigraphy scan (CCK-CS) was the most common investigation followed by an endoscopy. A proton pump inhibitor was most commonly prescribed treating the condition. The majority of respondents considered a referral for a surgical evaluation when CCK-CS showed a decreased gallbladder ejection fraction (GBEF) value with biliary-type pain during CCK injection.

CONCLUSION

CCK infusion rate in CCK-CS-CS and GBEF cut-off limits were inconsistent throughout practices. The criteria for a referral to a surgeon were not uniform from one practitioner to another. A multidisciplinary team approach with pediatric gastroenterologists and surgeons is required guide the decision-making managing a child with suspected FGBD. ​

Cholecystectomy for biliary dyskinesia: how did we get there?

BACKGROUND

The focus of biliary dyskinesia (BD) shifted within the last 30 years, moving from symptoms after cholecystectomy (CCY) to symptoms with morphological normal gallbladder, but low gallbladder ejection fraction.

METHODS

We searched the pubmed database to systematically review studies focusing on the diagnosis and treatment of gallbladder dysfunction.

RESULTS

Impaired gallbladder contraction can be found in about 20% of healthy controls and an even higher number of patients with various other disorders. Surgery for BD increased after introduction of laparoscopic CCY, with BD now accounting for >20% of CCY in adults and up to 60% in pediatric patients. The majority of cases reported were operated in the USA, which differs from surgical series for cholelithiasis. Postoperative outcomes do not differ between groups with abnormal or normal gallbladder function.

CONCLUSION

Functional gallbladder testing should not be seen as an indicator of relevant biliary tract disease or prognostic marker to identify patients who may benefit from operative intervention. Instead biliary dyskinesia should be considered as a part of a spectrum of functional disorders, which are generally managed conservatively. Small proof of concept studies have demonstrated effects of medical therapy on biliary dysfunction and should thus be never tested in appropriately designed trials.

Nuclear medicine tests for acute gastrointestinal conditions

Acute cholecystitis (AC) and lower-gastrointestinal (GI) bleeding are 2 emergencies commonly encountered in nuclear medicine. Evidence of AC on hepatobiliary scintigraphy (HBS) allows for confident diagnosis and provides support for definitive surgical treatment. Proper patient preparation is essential for HBS including fasting and the use of pharmacologic adjuncts is sometimes required. Pharmacologic adjuncts may also be administered during HBS to shorten the length of the examination and increase its specificity. In the interpretation of HBS, there are several sources of false-positive results to be aware of, most commonly chronic cholecystitis. False-negative results on HBS are usually the result of mistaking another structure, such as a dilated cystic duct, for the gallbladder. Abdominal ultrasound is the appropriate initial test in patients with suspected AC, but HBS is an excellent second tier test for the diagnosis of AC in the work-up of indeterminate cases by sonography. GI bleeding scintigraphy plays an important role in the evaluation and management of patients with acute lower-GI bleeding. Scintigraphy serves to localize sites of active GI bleeding and stratify those patients who would benefit from aggressive treatment (surgery or arteriography) vs those who can be managed medically. Pretest involvement of respective services is critical for successful bleeding site confirmation and therapy by interventional radiology or surgery or both. Single photon emission computed tomography/computed tomography erythrocyte scintigraphy has demonstrated superior accuracy and precision over planar scintigraphy in the diagnosis of acute GI bleeding. Additionally, single photon emission computed tomography/computed tomography scintigraphy of GI bleeding provides useful supplemental anatomical information that benefits patient management.

Role of cholescintigraphy in management of acute acalculous cholecystitis

Aim:

This study is aimed to evaluate the role of cholescintigraphy in management of acute acalculous cholecystitis.

Materials and Methods:

A total of thirty two patients who had presented to the surgical out-patient department or referred from in-patient department or intensive care unit between February 2008 and February 2010 were studied. All patients with Ultrasonography abdomen findings of acalculous cholecystitis were included in the study and they underwent cholescintigraphy. Gall bladder ejection fraction (GBEF) was calculated 30 min after fatty meal. Patients who either had non-visualization of gall bladder or GBEF less than 40% were considered to have acalculous cholecystitis on cholescintigraphy. The patients were followed-up for a period of 3 months after the commencement of treatment.

Results:

Eleven patients had either non-visualization of gall bladder or GBEF < 40%. Of these, six patients underwent cholecystectomy and the rest were medically managed, as patients deferred surgery. 83.33% of post-cholecystectomy patients as against 40% of medically treated patients were symptom free. Twenty one patients had GBEF > 40%, 90.74% of these patients were symptom free at the end of 3 months, with medical management.

Conclusion:

Cholescintigraphy is an important adjunct in management of patients with acalculous cholecystitis by guiding the course of therapy-surgical management versus medical management.

Sincalide cholescintigraphy--32 years later: evidence-based data on its clinical utility and infusion methodology

Sincalide cholescintigraphy was first reported to have clinical utility in 1980. Since then, many publications have found that a reduced gallbladder ejection fraction (GBEF) can confirm the clinical diagnosis of acalculous chronic gallbladder disease and predict symptomatic relief with cholecystectomy. However, some publications had not found the test clinically predictive. Many different sincalide infusion methods and normal values have been used. It had been suspected that the different infusion methods and normal values might account for the variability in reported utility. Furthermore, clinical review articles have raised questions about the evidence-based quality of the published data on the diagnostic utility of sincalide cholescintigraphy. A recently published multicenter trial has established the optimal methodology for sincalide infusion and normal values. A subsequent multispecialty consensus publication has recommended that this method be the standard method for sincalide infusion, specifically, a 60-minute infusion of 0.02 μg/kg (abnormal GBEF, <38%). The consensus publication also recommended that a large, multicenter, randomized, prospective trial was needed to confirm the utility of a low GBEF to predict acalculous chronic gallbladder disease and the patient's response to cholecystectomy.

Normokinetic biliary dyskinesia: a novel diagnosis

BACKGROUND

Biliary dyskinesia diagnosed with CCK-HIDA scan and ejection fraction less than 35 % has been successfully treated by laparoscopic cholecystectomy. However, a population of patients with symptomatic biliary pain and a normal CCK-HIDA scan never receive a diagnosis, and thus no definitive treatment. Some of these patients report a reproducible pain during their CCK-HIDA scan. It is hypothesized that these patients have a novel diagnosis, normokinetic biliary dyskinesia, and may have resolution of pain when treated with cholecystectomy.

METHODS

A retrospective chart review was completed looking for patients with biliary pain in accordance with the ROME III criteria. Additional inclusion criteria were (1) greater than age 18 years, (2) reproducible biliary symptoms during the CCK-HIDA scan, and (3) an ejection fraction greater than 35 %. Treatment modality was laparoscopic cholecystectomy. Descriptive statistics were preformed, and data were reported as mean ± standard deviation and range.

RESULTS

Nineteen patients met the inclusion criteria for this study from August 2008 to July 2011. There were 15 women and 4 men with a mean age of 48.4 ± 13.0 years. The mean ejection fraction was 75.1 ± 19.4 %. The average duration of preoperative symptoms was 6.8 ± 5.9 months and postoperative follow-up was 21.8 ± 10.6 months. Seventeen patients had complete resolution of symptoms, one had partial resolution, and one had no change. There was a complete resolution rate of 89.5 % and an improvement rate of 94.7 %.

CONCLUSIONS

We suggest that patients who present with biliary pain, a normal CCK-HIDA scan with an ejection fraction greater than 35 %, and with reproducible symptoms on infusion of CCK could have a novel diagnosis: normokinetic biliary dyskinesia. Currently, these patients are excluded from the diagnosis of biliary dyskinesia and thus treatment. We hypothesize a potential new diagnosis, suggest cholecystectomy as treatment, and recommend a prospective study design for further evaluation.

Cholecystokinin-cholescintigraphy in adults: consensus recommendations of an interdisciplinary panel

BACKGROUND AND AIMS

Cholecystokinin-cholescintigraphy (CCK-CS) provides a physiologic, noninvasive, and quantitative method for assessing gallbladder contraction and calculation of a gallbladder ejection fraction (GBEF). At present, it is used most commonly to identify patients with suspected functional gallbladder disorder. However, the methodology of CCK infusion and normal values differ markedly among imaging centers.

METHODS

This document represents the consensus opinion of an interdisciplinary panel that gathered to assess the current optimal method for performing CCK-CS in adults, potential uses and limitations of CCK-CS, and questions that require further investigation.

RESULTS

The panel recommended the use of a single, standardized, recently described CCK-CS protocol that involves infusion of 0.02 μg/kg of sincalide over 60 minutes with a normal GBEF defined as ≥38%. The panel emphasized the need for a large, multicenter, prospective clinical trial to establish the utility of CCK-CS in the diagnosis of functional gallbladder disease. Although not without controversy regarding its clinical utility, the primary indication for CCK-CS at present is the well-selected patient with suspected functional gallbladder disorder.

CONCLUSION

Agreement was reached that the adoption of this standardized protocol is critical to improve how CCK-CS is used to direct patient care and will represent an improvement over the diverse methods currently in use by eliminating the current lack of uniformity and adding both reliability and credibility to the results.

Variabilities of gallbladder contraction indices and a simple regression model for gallbladder and gastric emptying ratio

Introduction

The objective of this study was to assess the variabilities of gallbladder contraction indices (GBCI) and derive a predictive model for gallbladder and gastric motility.

Methods

The gallbladder volume and gastric antral measurements were obtained from 24 healthy male volunteers in preprandial and post-milk ingestion states. After preprandial measurement of the gallbladder volume and gastric antral area, each subject ingested 157 ml of full cream milk and 30 cl of ion -free water. In supine position, the gallbladder volume and the gastric antral area were obtained every five minutes for 40 minutes. For the gallbladder while only the 5 ^th, 10 ^th and 15 ^th measurement of gastric antral area were obtained. Gallbladder contraction indices were calculated and gastric emptying ratio obtained at the fifteenth minute is the indication of gastric motility. Statistical analyses were conducted using SPSS version 16.0 with p<0.05 as criterion of statistical significance.

Results

The GBCIs followed Gaussian response at some stages and did not at some other stages. The least variability occurred at the 35th measurement of GBCI. A cut- off value for the 35th minute GBCI value was established with the mean±2 SD (80.79±11.5%). Obvious gallbladder refilling was noted after 35minutes. A positive relationship was noted between gallbladder and gastric motilities.

Conclusion

With milk dilution, the variability of gall bladder motility is least at the 35th minute. A significant positive relationship between gastric emptying and gallbladder contraction index was also observed.

Cholecystokinin-cholescintigraphy in adults: consensus recommendations of an interdisciplinary panel

BACKGROUND & AIMS

Cholecystokinin-cholescintigraphy (CCK-CS) provides a physiologic, noninvasive, and quantitative method for assessing gallbladder contraction and calculation of a gallbladder ejection fraction (GBEF). At present, it is used most commonly to identify patients with suspected functional gallbladder disorder. However, the methodology of CCK infusion and normal values differ markedly among imaging centers.

METHODS

This document represents the consensus opinion of an interdisciplinary panel that gathered to assess the current optimal method for performing CCK-CS in adults, potential uses and limitations of CCK-CS, and questions that require further investigation.

RESULTS

The panel recommended the use of a single, standardized, recently described CCK-CS protocol that involves infusion of 0.02 μg/kg of sincalide over 60 minutes with a normal gallbladder ejection fraction defined as ≥38%. The panel emphasized the need for a large, multicenter, prospective clinical trial to establish the utility of CCK-CS in the diagnosis of functional gallbladder disease. Although not without controversy regarding its clinical utility, the primary indication for CCK-CS at present is the well-selected patient with suspected functional gallbladder disorder.

CONCLUSIONS

Agreement was reached that the adoption of this standardized protocol is critical to improve how CCK-CS is used to direct patient care and will represent an improvement over the diverse methods currently in use by eliminating the current lack of uniformity and adding both reliability and credibility to the results.

Gallbladder dyskinesia: fact or fiction?

Gallbladder dyskinesia is a functional (motility) disorder of the gallbladder resulting in episodic abdominal pain that, in carefully selected cases, resolves with cholecystectomy. It is a diagnosis of exclusion: several functional and organic disorders have to be excluded, and confounding factors addressed, before a diagnosis of gallbladder dyskinesia can be entertained. The combination of high clinical suspicion and an abnormally low gallbladder ejection fraction on cholecystokinin stimulated-cholescintigraphy predict benefit from removing the gallbladder.

Nuclear medicine hepatobiliary imaging

Nuclear medicine hepatobilary imaging (HIDA) is a time proven imaging methodology that uses radioactive drugs and specialized cameras to make imaging diagnoses based on physiology. HIDA radiopharmaceuticals are extracted by hepatocytes in the liver and cleared through the biliary system similar to bilirubin. The most common indication for HIDA imaging is acute cholecystitis, diagnosed by nonfilling of the gallbladder due to cystic duct obstruction. HIDA can detect high grade biliary obstruction prior to ductal dilatation; images reveal a persistent hepatogram without biliary clearance due to the high backpressure. HIDA also aids in the diagnosis of partial biliary obstruction due to stones, biliary stricture, and sphincter of Oddi obstruction. It can confirm biliary leakage postcholecystectomy and hepatic transplantation. Calculation of a gallbladder ejection fraction after cholecystokinin infusion is commonly used to diagnose chronic acalculous gallbladder disease. Diseased gallbladders do not contract. There are many other less common but valuable diagnostic indications for HIDA imaging.

HIDA scan ejection fraction does not predict sphincter of Oddi hypertension or clinical outcome in patients with suspected chronic acalculous cholecystitis

BACKGROUND

Hepatobiliary iminodiacetic scan with ejection fraction (HIDA EF) is used to evaluate chronic acalculous cholecystitis (CAC). A presumed etiology of CAC is sphincter of Oddi hypertension (SOH). In this study, we evaluated the value of HIDA EF to predict patient response to laparoscopic cholecystectomy and to identify SOH.

METHODS

A prospective study of 93 patients with biliary pain but without gallstones (CAC) who underwent preoperative HIDA EF was conducted. At laparoscopic cholecystectomy, transcystic antegrade biliary manometry was performed to determine the SO pressure. Patients were evaluated postoperatively for response to cholecystectomy. The sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) were calculated. The outcomes were compared with the clinical impression.

RESULTS

Of the 93 patients with both HIDA EF and SOP measurements, 50 had abnormal EF (< 35%); of these, 29 had SOH (SO pressure > or = 40 mmHg). Of the 43 patients with normal HIDA EF, 30 had SOH. The sensitivity was 49%, specificity 38%, PPV 58%, and NPV 30%. Eighty-six of the 93 patients returned for follow-up evaluation. Follow-up ranged from 0 to 99 months, with a mean of 26.4 months. Overall, 73 patients (85%) improved. Of the 46 with abnormal HIDA EF, 42 (91%) improved. Of the 40 patients with normal HIDA EF, 31 (77.5%) improved. The sensitivity was 57.7%, specificity 69.2%, PPV 91.3%, and NPV 22.5%.

CONCLUSION

Although the PPV of abnormal HIDA EF is high, it is not much better than the clinical impression. The sensitivity and specificity are marginal. The NPV is poor. Based on the review of these 93 patients, HIDA EF is not reliable for identifying CAC. We recommend that patients with normal HIDA EF have additional testing or consultation before ruling out CAC. HIDA EF does not predict SOH.

Segmentation of the gallbladder: Effect on bile entry and exit and its clinical relevance in a patient with abdominal pain

BACKGROUND

The effects of folds or septa on gallbladder filling and emptying are not known.

METHODS

Gallbladder filling and emptying were measured in seven patients with two chambers (segmental) and compared with 10 subjects with a single chamber (control). Percent bile flow into gallbladder, and percent ejection fraction from the proximal and distal segments, and entire gallbladder were measured with cholecystokinin.

RESULTS

Bile entry into gallbladder was similar in both groups. In patients with segmentation, overall emptying was low mostly due to poor emptying of the distal segment.

CONCLUSION

Segmentation of the gallbladder does not affect bile entry, but acting as a one-way valve, a fold or septum lowers emptying significantly, mostly from the distal segment.

Functional hepatobiliary disease: chronic acalculous gallbladder and chronic acalculous biliary disease

Chronic acalculous gallbladder and chronic acalculous biliary disease are considered functional hepatobiliary diseases. Cholescintigraphy provides physiologic imaging of biliary drainage, making it ideally suited for their noninvasive diagnosis. For chronic acalculous gallbladder disease, calculation of a gallbladder ejection fraction during sincalide cholescintigraphy can confirm the clinical diagnosis and has become a common routine procedure in many nuclear medicine clinics. Published data generally confirm a high overall accuracy for predicting relief of symptoms with cholecystectomy. However, data also exist suggesting it is not useful. The discrepant results probably are caused by the various different methodologies that have been used for sincalide infusion. Proper methodology of sincalide infusion is critical for providing accurate reproducible results, minimizing false positive studies, and preventing adverse side effects. The most common causes for the postcholecystectomy pain syndrome are partial biliary obstruction secondary to stones or tumor and sphincter of Oddi dysfunction. The latter is a partial biliary obstruction at the level of the sphincter. This has long been considered a functional hepatobiliary disease because of the lack of anatomical abnormalities. Sphincterotomy is the present treatment; however, diagnosis requires invasive procedures, such as endoscopic retrograde cholangiopancreatography and sphincter of Oddi manometry, which has a high complication rate and is not widely available. The unique ability of cholescintigraphy to image biliary drainage allows noninvasive diagnosis. Different methodologies have been reported, many with good overall accuracy. Various pharmacologic interventions and quantitative methodologies have been used in conjunction with cholescintigraphy to enhance its diagnostic capability. Further investigations are needed determine the optimal methodology; however, cholescintigraphic methods have already a clinical role in the diagnosis of sphincter of Oddi dysfunction and will be used increasingly in the future.

Determination of the biliary excretion of piperacillin in humans using a novel method

AIM

To evaluate the applicability of a novel method to determine the biliary excretion of piperacillin.

METHODS

Healthy volunteers were administered piperacillin i.v. Duodenal aspirates were collected via a custom-made oroenteric catheter; blood and urine also were collected. Gallbladder ejection fraction (EF) was determined by gamma scintigraphy and pharmacokinetic parameters were calculated using noncompartmental analysis.

RESULTS

The fraction of the piperacillin dose excreted unchanged into bile was 1.1 +/- 0.3% (biliary clearance corrected for EF was 0.032 +/- 0.008 ml min(-1) kg(-1)).

CONCLUSIONS

This methodology can be used to determine reliably the biliary clearance of drugs that are excreted only marginally into bile. Normalization of biliary clearance for EF significantly reduces intersubject variability of this parameter.

Methods to evaluate biliary excretion of drugs in humans: an updated review

Determining the biliary clearance of drugs in humans is very challenging because bile is not readily accessible due to the anatomy of the hepatobiliary tract. The collection of bile usually is limited to postsurgical patients with underlying hepatobiliary disease. In healthy subjects, feces typically are used as a surrogate to quantify the amount of drug excreted via nonurinary pathways. Nevertheless, it is very important to characterize hepatobiliary elimination because this is a potential site of drug interactions that might result in significant alterations in systemic or hepatic exposure. In addition to the determination of in vivo biliary clearance values of drugs, the availability of in vitro models that can predict the extent of biliary excretion of drugs in humans may be a powerful tool in the preclinical stages of drug development. In this review, recent advances in the most commonly used in vivo methods to estimate biliary excretion of drugs in humans are outlined. Additionally, in vitro models that can be employed to investigate the molecular processes involved in biliary excretion are discussed to present an updated picture of the new tools and techniques that are available to study the complex processes involved in hepatic drug transport.

Cholecystokinin and gastrin receptors

Cholecystokinin and gastrin receptors (CCK1R and CCK2R) are G protein-coupled receptors that have been the subject of intensive research in the last 10 years with corresponding advances in the understanding of their functioning and physiology. In this review, we first describe general properties of the receptors, such as the different signaling pathways used to exert short- and long-term effects and the structural data that explain their binding properties, activation, and regulation. We then focus on peripheral cholecystokinin receptors by describing their tissue distribution and physiological actions. Finally, pathophysiological peripheral actions of cholecystokinin receptors and their relevance in clinical disorders are reviewed.

Surgical Therapy for Biliary Dyskinesia: A Meta-analysis and Review of the Literature

BACKGROUND

Although biliary dyskinesia is treated commonly with cholecystectomy, the supporting literature is limited. A review and meta-analysis of the literature were performed to assess the efficacy of surgical therapy for biliary dyskinesia.

MATERIALS AND METHODS

A MEDLINE search for the period 1965 to 2003, using the search strings "biliary," "acalculous," "dyskinesia," "cholecystitis," "cholecystectomy," and "therapy" returned 187 articles. Inclusion criteria required a study design that placed patients with biliary dyskinesia into one of two treatment groups, cholecystectomy or nonoperative therapy, and a follow-up assessment of symptomatic improvement.

RESULTS

Five studies met the inclusion criteria, representing a total of 274 patients. Surgical therapy resulted in 98% symptomatic relief compared to 32% with nonoperative management (P<0.0001). Patients undergoing surgical therapy for biliary dyskinesia were 2.79 times more likely to have symptomatic relief versus nonoperative therapy (95% confidence interval, 2.05-3.79).

CONCLUSION

Based on this meta-analysis, cholecystectomy for biliary dyskinesia is an effective therapy and offers significant symptomatic relief over nonoperative therapy.

Controversies concerning pathophysiology and management of acalculous biliary-type abdominal pain

Acalculous biliary-type abdominal pain is a commonly encountered clinical problem whose pathophysiology is unclear and evaluation and management are controversial. Cholecystokinin cholescintigraphy to measure the gallbladder ejection fraction (GEF) has been advocated as a criterion for cholecystectomy. However, there is no consensus regarding the dose and rate of infusion of cholecystokinin, both of which can alter the GEF, and the definition of an abnormal ejection fraction varies among studies. Many but not all studies have concluded that a low GEF predicts good outcomes after cholecystectomy, but most studies suffer from poor methodology and there is only one prospective randomized controlled trial. Also, some patients with a normal GEF have responded to cholecystectomy. Another controversial area has been the role of sphincter of Oddi dysfunction (SOD) in patients with biliary-type pain and gallbladder in situ. Some reports suggest an overlap between SOD and low GEF, although a causal relationship has not been established. Yet another subject of interest is the role of visceral hyperalgesia in patients with acalculous biliary-type pain. We have reviewed the relevant literature relating to these issues and have highlighted the controversial aspects. In the absence of high-quality studies, an evidence-based treatment algorithm is difficult to design but will be proposed. More prospective controlled trials are warranted to better define the appropriate evaluation and management of patients with this syndrome.

Functional biliary-type pain: update and controversies

Recurrent biliary-type abdominal pain is a perplexing clinical dilemma that occurs in patients with an acalculous gallbladder in situ or in patients who have undergone a previous cholecystectomy. The pathogenesis of functional biliary-type pain is often unclear; therefore, evaluation and management remain controversial. In patients with an acalculous gallbladder in situ, critical importance has been given to delayed gallbladder emptying using cholescintigraphy (CCK-CS) to determine if gallbladder dysfunction is present. However, several issues remain unresolved, including methodology, definition of delayed emptying, and the absence of high-quality studies to determine if CCK-CS can predict who will do well with cholecystectomy. In patients with previous cholecystectomy, the main area of controversy is the evaluation of patients with sphincter of Oddi Type III, including the role of endoscopic retrograde cholangiopancreatography with SO manometry and sphincterotomy in these patients. Suggested algorithms for management of both clinical scenarios are provided.

A novel method for the determination of biliary clearance in humans

Biliary excretion is an important route of elimination and the biliary tract is a potential site of toxicity for many drugs and xenobiotics. Quantification of biliary excretion in healthy human volunteers is logistically challenging and is rarely defined during drug development. The current study uses a novel oroenteric tube coupled with a specialized clinical protocol to examine the pharmacokinetics of 99mTechnetium (Tc-99m) mebrofenin, a compound that undergoes rapid hepatic uptake and extensive biliary excretion. A custom-made multilumen oroenteric tube was positioned in the duodenum of healthy human volunteers. Subjects were positioned under a gamma camera and 2.5 mCi of Tc-99m mebrofenin was administered intravenously. Duodenal aspirates, blood samples, and urine were collected periodically for 3 hours. Two hours after Tc-99m mebrofenin administration, the gallbladder was contracted with an intravenous infusion of cholecystokinin-8. Gamma scintigraphy was used to determine the gallbladder ejection fraction in each subject. Total systemic clearance of Tc-99m mebrofenin approximated liver blood flow (Cl(total) 17.3 degrees 1.7 mL/min/kg), and 35% to 84% of the Tc-99m mebrofenin dose was recovered in bile. However, when the data were corrected for the gallbladder ejection fraction, 71% to 92% of the excreted Tc-99m mebrofenin dose was recovered. This novel oroenteric tube and clinical protocol provide a useful method to quantify biliary excretion of xenobiotics in healthy human volunteers.

Does gallbladder ejection fraction predict outcome after cholecystectomy for suspected chronic acalculous gallbladder dysfunction? A systematic review

The clinical utility of cholecystokinin-cholescintigraphy with calculation of a gallbladder ejection fraction (GBEF) in patients with suspected chronic acalculous gallbladder dysfunction (CAGD) remains controversial. It was our aim to critically evaluate the literature on the utility of the GBEF to predict outcome of patients with suspected CAGD. We performed an electronic search of the MEDLINE database for articles published between 1980 and 2002 and a manual search of references from bibliographies of identified articles. Only articles in English that concerned adults were screened. Data extracted included both qualitative and quantitative data reported on the study groups, cholescintigraphic technique, interventions, treatment outcomes, and trial methodologic characteristics. Twenty-three publications met the inclusion criteria. All were considered of poor methodologic quality. All but three studies were retrospective case series, only one was randomized, and none were adequately blinded, used adequate controls, or enrolled a sufficient number of patients. Five studies used a cut-off value for an abnormal GBEF that was different than the value used by the others, one study did not provide a cut-off value, and several did not report details of the cholescintigraphic technique (namely, the rate of cholecystokinin infusion). Studies varied in their outcome measures and the criteria for success. The overall assessment of outcome in 19 studies concluded that calculation of a GBEF was useful in patients with suspected CAGD. The low methodologic quality of the studies precluded a meta-analysis approach to the data. Use of a calculated GBEF to diagnose and predict treatment outcome in suspected CAGD has not been adequately studied. Although most studies report utility of GBEF in predicting symptom outcome after cholecystectomy in patients with suspected CAGD, quality evidence is lacking, thereby precluding a definitive recommendation regarding its use. More high quality trials are needed.

Acute cholecystitis, biliary obstruction, and biliary leakage

The use of cholescintigraphy to diagnose acute cholecystitis, biliary obstruction, and biliary leakage dates back to the late 1970s. Today, despite the many advances in imaging instrumentation, radiopharmaceuticals, and methodology over these years, cholescintigraphy still plays an important role in confirming or excluding these diagnoses in acutely ill patients. Acute calculous and acalculous cholecystitis, gallbladder perforation, biliary obstruction, and biliary leakage often present as acute abdominal pain, and must be differentiated from other surgical and nonsurgical etiologies with similar symptoms and presentation. Understanding the pathophysiology of acute hepatobiliary diseases is vital for deciding on the most advantageous imaging work-up and for interpretation of the studies. To optimize the value of cholescintigraphy, up-to-date methology, proper use of appropriate pharmacologic interventions, and recognition of characteristic image findings are critical.

Systematic review and meta-analysis: does gall-bladder ejection fraction on cholecystokinin cholescintigraphy predict outcome after cholecystectomy in suspected functional biliary pain?

BACKGROUND

Patients with suspected functional biliary pain often undergo cholecystectomy if a decreased gall-bladder ejection fraction (GBEF <35%) is demonstrated by cholecystokinin cholescintigraphy. However, the validity of GBEF in predicting which patients will have symptomatic relief following cholecystectomy is unclear.

AIM

To determine whether patients with suspected functional biliary pain with decreased GBEF have a better symptomatic outcome after cholecystectomy than those with normal GBEF.

METHODS

Systematic review and meta-analysis of the published literature through MEDLINE and EMBASE databases.

RESULTS

We included nine studies with a total of 974 patients with suspected functional biliary pain; 362 patients underwent cholecystectomy. Most studies assessed outcome by direct patient interview. Mean ages across the studies ranged from 35 to 47 years; 78% of all patients were female. Mean duration of follow-up after surgery ranged from 1 to 2.5 years. After cholecystectomy, 94% of the patients with reduced GBEF had a positive outcome compared to 85% among those with normal GBEF. The pooled Mantel-Haenszel odds ratio for positive outcome was 1.37 (95% confidence interval 0.56-3.34), P=0.56.

CONCLUSION

These data do not support the use of GBEF to select patients with suspected functional biliary pain for cholecystectomy. Prospective randomized trials are required if this practice is to be evidence-based.

Methods of measuring gallbladder motor functions--the need for standardization: scintigraphy

Emptying the gallbladder is part of the complex process of food digestion. The gallbladder interacts with other gastrointestinal organs and its movements are coordinated and modified by functions of the stomach, intestine and pancreas. Many factors can modify gallbladder motility, for example, sex and age of the subject, their body mass, the kinds of food ingested and stimulus used. The assumption that the gallbladder progressively empties during meals and refills during fasting is incorrect. Using a combination of ultrasonography and cholescintigraphy, it is possible to measure absolute and net gallbladder emptying. In this way we demonstrated that the gallbladder begins to refill immediately after emptying begins, and the difference between net and absolute emptying of the gallbladder indicates the refilling of bile and provides a measure of bile turnover rate, an accurate index to assess gallbladder motility.

Involvement of cholecystokinin/gastrin-related peptides and their receptors in clinical gastrointestinal disorders

In this paper the possible roles of cholecystokinin (CCK), gastrin, or gastrin-related peptides and their receptors in human gastrointestinal diseases are reviewed. For CCK/CCK(A) receptors (CCK(A)-R), the evidence for their proposed involvement in diseases caused by impaired CCK release or CCK(A)-R mutations, pancreatic disorders (acute/chronic pancreatitis), gastrointestinal motility disorders (gallbladder disease, irritable bowel syndrome), pancreatic tumor growth and satiety disorders, is briefly reviewed. The evidence that has established the involvement of gastrin/CCK(B)-R in mediating the action of hypergastrinaemic disorders, mediating hypergastrinaemic effects on the gastric mucosa (ECL hyperplasia, carcinoids, parietal cell mass), and acid-peptic diseases, is reviewed. The evidence for their possible involvement in mediating growth of gastric and pancreatic tumours and possible involvement of gastrin-related peptides in colon cancers, is reviewed briefly.