Cholecystolithiasis: lithotherapy for the 1990s

Gallstones

Gallstone disease is a worldwide medical problem, but the incidence rates show substantial geographical variation, with the lowest rates reported in African populations. Publications in English language on gallstones which were obtained from reprint requests and PubMed database formed the basis for this paper. Data extracted from these sources included authors, country, year of publication, age and sex of patients, pathogenesis, risk factors for development of gallstones, racial distribution, presenting symptoms, complications and treatment. Gallstones occur worldwide, however it is commonest among North American Indians and Hispanics but low in Asian and African populations. High biliary protein and lipid concentrations are risk factors for the formation of gallstones, while gallbladder sludge is thought to be the usual precursor of gallstones. Biliary calcium concentration plays a part in bilirubin precipitation and gallstone calcification. Treatment of gallstones should be reserved for those with symptomatic disease, while prophylactic cholecystectomy is recommended for specific groups like children, those with sickle cell disease and those undergoing weight-loss surgical treatments. Treatment should be undertaken for a little percentage of patients with gallstones, as majority of those who harbor them never develop symptoms. The group that should undergo cholecystectomy include those with symptomatic gallstones, sickle cell disease patients with gall stones, and patients with morbid obesity who are undergoing laparotomy for other reasons.

Fibroblast growth factor receptor 4 Gly388Arg polymorphism associated with severity of gallstone disease in a Chinese population

The etiology of gallstone disease is multifactorial; supersaturation of bile with cholesterol is a primary cause for gallstone formation. In previous studies, we found that fibroblast growth factor receptor 4 (FGFR4) plays an important role in maintaining bile acid homeostasis by regulating the expression of cholesterol 7α-hydroxylase (CYP7A1), a rate-limiting enzyme for bile acid biosynthesis. The Gly388Arg (G-388R) polymorphism of FGFR4 affects stabilization and activation of FGFR4. Consequently, we studied the FGFR4 gene as a candidate gene for genetic susceptibility to gallstone disease. We found that overexpression of FGFR4, especially the G-388R mutant of FGFR4, inhibits luciferase activity of CYP7A1 reporter in HepG2 cells, indicating that the G-388R mutant of FGFR4 may have greater inhibitory activity against bile acid biosynthesis. To investigate the association of FGFR4 polymorphism with gallstone disease, 117 patients with gallstone disease and 457 controls were genotyped for FGFR4 polymorphism G-388R by PCR-RFLP. Although the incidence of gallstone disease was not greater in patients with the FGFR4 RR genotype, the ratio of gallstone patients with acute cholecystitis in the FGFR4 RR genotype (42%) was significantly higher than that in other genotypes of FGFR4 (P = 0.019). In conclusion, the FGFR4 polymorphism is a genetic risk factor contributing to aggravation of gallstone disease.

Gallstone disease: from genes to evidence-based therapy

The number of gallstone patients is increasing in ageing populations with a high prevalence of metabolic syndrome and obesity. Recently variants of hepatic ATP binding cassette transporters have been identified as genetic susceptibility factors for gallstone disease, pointing to novel means for risk assessment and prevention. Although laparoscopic cholecystectomy is the mainstay of therapy for symptomatic gallbladder stones, the clinical management of gallstone disease is changing rapidly, with an increase in day case surgery and the advent of transluminal endoscopic surgery. Here, we summarize the molecular and genetic mechanisms of gallstone formation as well as the current evidence-based algorithms for diagnosis and therapy of gallbladder and bile duct stones.

Effect of oophorectomy and exogenous estrogen replacement on liver injury in experimental obstructive jaundice

AIM: To investigate the role of estrogen on liver injury in an experimental obstructive jaundice model.

METHODS: Three groups of female rats were constituted; group 1 was oophorectomized and given E2 (n = 14), group 2 was oophorectomized and given placebo (n = 14), and group 3 was sham operated (n = 14). Fourteen days following constitution of bile duct ligation, all groups were compared in terms of serum tests, histopathologic parameters, and tissue levels of IFN-γ and IL-6.

RESULTS: The parameters representing both the injury and/or the reactive response and healing were more pronounced in groups 1 and 2 (χ² = 17.2, χ² = 10.20; χ² = 12.4, P < 0.05). In the sham operated or E2 administered groups significantly lower tissue levels of IFN-γ and higher IL-6 levels were found. In contrast, high IFN-γ and low IL-6 tissue levels were found in the oophorectomized and placebo group (P < 0.001). Kupffer cell alterations were observed to be more pronounced in the groups 1 and 3 (χ² = 6.13, P < 0.05).

CONCLUSION: Our study indicates that E2 impaired liver functions, accelerated both the liver damage and healing. In the conditions of bile duct obstruction, estrogen significantly changed the cytokine milieu in the liver.

Management of cholelithiasis in Italian children: A national multicenter study

AIM: To evaluate the management of Italian children with cholelithiasis observed at Pediatric and Surgical Departments linked to Italian Society of Pediatric Gastroenterology Hepatology and Nutrition.

METHODS: One-hundred-eighty children (90 males, median age at diagnosis 7.3 years; range, 0-18 years) with echographic evidence of cholelithiasis were enrolled in the study; the data were collected by an anonymous questionnaire sent to participating centers.

RESULTS: One hundred seventeen patients were treated with ursodeoxycholic acid; in 8 children dissolution of gallstones was observed, but the cholelithiasis recurred in 3 of them. Sixty-five percent of symptomatic children treated became asymptomatic. Sixty-four patients were treated with cholecystectomy and in only 2 cases a postoperative complication was reported. Thirty-four children received no treatment and were followed with clinical and echographic controls; in no case the development of complications was reported.

CONCLUSION: The therapeutic strategies were extremely heterogeneous. Ursodeoxycholic acid was ineffective in dissolution of gallstones but it had a positive effect on the symptoms. Laparoscopic cholecystectomy was confirmed to be an efficacy and safe treatment for pediatric gallstones.

A questionnaire for the assessment of biliary symptoms

OBJECTIVES

Gallstone disease is common and causes high health care costs, but a measure of symptomatic biliary disease for outcome studies is lacking. We aimed to develop a reproducible, valid, discriminative, disease-specific measure of biliary symptoms.

METHODS

We created the self-report Biliary Symptoms Questionnaire (BSQ) by combining possible biliary symptoms with validated items for gastroesophageal reflux disease (GERD), irritable bowel syndrome (IBS), and other disorders. We developed the final version through an iterative process and assessed reproducibility by the test-retest method, concurrent validity by comparing BSQ responses with symptoms obtained by structured interview, and discriminative validity by comparing BSQ-based diagnoses of biliary symptoms, GERD, and IBS with patients' final diagnoses. A shortened version (sBSQ) also underwent reproducibility testing.

RESULTS

A total of 245 outpatients (mean age, 55.2 yr; 61% female) participated. Median completion times for the BSQ and sBSQ were 36 and 10 min, respectively. For the BSQ, median kappa values were 0.65 (range -0.03 to 0.95) for reproducibility and 0.61 (range 0.15-0.95) for concurrent validity. Using BSQ responses, investigators distinguished IBS and GERD 79-90% of the time. For the sBSQ, the median kappa value for reproducibility was 0.72 (range 0.32-0.86).

CONCLUSIONS

The BSQ is reproducible and has good concurrent and discriminative validity for biliary symptoms. The abridged sBSQ has good reproducibility. These instruments may be useful in future outcome studies.

Clinical manifestations of gallstone disease: evidence from the multicenter Italian study on cholelithiasis (MICOL)

Despite the many efforts to delineate the clinical manifestations of gallbladder disease, the precise symptom complex associated with gallstones is still a matter of debate, and even the existence of gallstone-specific symptoms has been questioned. We carried out a large population-based cross-sectional study (MICOL) to identify symptoms significantly related to gallstones. Fourteen centers throughout Italy enrolled 29,504 subjects aged 30 to 69 years. All subjects were administered an ultrasonographic examination of the upper abdomen and a precoded questionnaire. All subjects were divided into 4 groups: 25,374 (86.0%) gallstone-free subjects (GF), 1,832 (6.2%) patients with gallstones not previously diagnosed (GNPD), 638 (2.2%) patients with gallstones previously diagnosed (GPD), 1,660 (5.6%) patients with a history of cholecystectomy for gallstones (CC). In logistic regression analysis, pain at epigastrium and, even more, pain at right hypocondrium were significantly associated with gallstones. For pain at right hypocondrium, this association progressively increased from GNPD (OR = 1.60, 95% CI = 0.97-2.65) to GPD (OR = 8.77, 95% CI = 5.27-14.61) to CC (OR = 59.40, 95% CI = 43.87-80.42). Absence of heartburn combined with right hypocondrium or epigastrium pain and intolerance to fried or fatty food were also significantly related to gallstones. We also found some pain characteristics significantly associated with gallstones, i.e., pain radiated to the right shoulder, forcing the patient to rest, occurring soon after meals or unrelated to meals, not relieved by bowel movements, and frequently accompanied by gallstone-related morbidities. We developed a probability tree reporting the cumulative probability of having gallstones for each combination of those symptoms and characteristics of pain significantly associated with gallstones. In conclusion, we have identified symptoms and signs significantly associated with gallstones. We have shown that there is an increase in frequency and severity of these symptoms and signs across the different stages of gallstone disease. We have proposed a complex of symptoms and signs significantly associated with gallstones that might help physicians in clinical decision making.

Long-term ursodeoxycholic acid therapy is associated with reduced risk of biliary pain and acute cholecystitis in patients with gallbladder stones: a cohort analysis

Whether ursodeoxycholic acid (UDCA) therapy alters the long-term clinical course of gallstones (GS) without stone dissolution remains unknown. We aimed to clarify the relationship between long-term UDCA therapy and risks of biliary pain or acute cholecystitis in GS patients. We also aimed to identify factors affecting the natural course, and to explore a simple patient selection criteria for UDCA therapy. A cohort of 527 uncomplicated GS patients with or without UDCA (600 mg/d) followed for up to 18 years was analyzed. Patients who had frequent attacks or were complicated with cholecystitis were converted to cholecystectomy. History and UDCA therapy were identified on Cox analysis as 2 factors affecting the long-term clinical course. In patients without therapy, history was the only predictor of biliary pain among various patient or stone characteristics; biliary pain was rare in asymptomatic patients, while frequent in symptomatic patients (P <.001). UDCA therapy was associated with reduced risk for biliary pain in both symptomatic (62% vs. 92% in untreated patients at 10 years; P <.001; relative risk, 0.19; 95% CI, 0.10-0.34) and asymptomatic patients (6% vs. 12% in untreated patients at 10 years; P =.037; relative risk, 0.19; 95% CI, 0.04-0.91). Risk for the conversion was also reduced in UDCA-treated symptomatic patients (26% vs. 88% in untreated patients at 10 years, P <.001; relative risk, 0.08; 95% CI, 0.03-0.22). These effects were independent of stone dissolution. Three factors were identified on Cox analysis as affecting GS dissolution: radiolucency, small size (<10 mm) of stones, and visualized gallbladder (GB) on cholecystogram. A selection criteria based on these appears to exhibit high sensitivity (74%) and specificity (95%) for dissolution. UDCA therapy might be considered in symptomatic patients fulfilling these criteria, and also in patients who have significant surgical risk, because the longterm therapy is clearly associated with reduced risk of biliary pain and acute cholecystitis.

Laparoscopic biliary surgery

Treatment of gallstones by laparoscopic cholecystectomy has become standard therapy over the past decade and has received wide patient acceptance. Problems are infrequent but those such as biliary injury may be serious and continue to be a cause of concern. Biliary injury is more likely when surgery is performed in the presence of acute inflammation. Laparoscopic bile duct exploration is becoming standardized and the results are good. The role of other laparoscopic biliary procedures such as biliary bypass is still uncertain.

Costs and effectiveness of extracorporeal gallbladder stone shock wave lithotripsy versus laparoscopic cholecystectomy. A randomized clinical trial. McGill Gallstone Treatment Group

Thirty-five patients were randomized to extracorporeal shock-wave lithotripsy (ESWL) and 25 to laparoscopic cholecystectomy (LC). Stone disappearance occurred in only 12 of 32 ESWL patients [38% (95% CI: 21-56%)] during a 15-month follow-up. Greater incremental gains in quality of life after 6 months were observed among LC patients (p < .01). Total duration of disability was 6.8 +/- 8.5 days for ESWL, and 22.7 +/- 16.6 days for LC (p < .01). Nine (28%) patients crossed over electively to the LC group, but only 44% of these underwent LC within the next 3 years. ESWL cost Can $58.9/ day of disability saved. ESWL is limited by its selective applicability and modest stone disappearance rate. Its cost-effectiveness is largely dependent on patient acceptance of recurrent episodes of biliary colic due to the persistence of stone fragments.

Cholelithiasis and acute cholecystitis

Although much is still to be learned about the pathogenesis of cholelithiasis, recent investigations have greatly advanced our knowledge regarding the mechanisms of cholesterol supersaturation and nucleation. Laparoscopic cholecystectomy has lessened the usual peri-operative morbidity of cholecystectomy, but is associated with a higher bile duct injury rate. Acute cholecystitis, the commonest complication of cholelithiasis, is a chemical inflammation usually requiring cystic duct obstruction and supersaturated bile. The treatment of this condition in the laparoscopic era is controversial. Early operation may lessen hospital stay but an increased risk of biliary injury has been reported.

Percutaneous transhepatic endoscopic electrohydraulic lithotripsy of biliary tract calculi after orthotopic liver transplantation

The development of biliary tract calculi after orthotopic liver transplantation presents a unique clinical problem. Previously described techniques for removing biliary stones by shock wave lithotripsy, litholytic therapy with oral bile acids, and endoscopic mechanical extraction may be ineffective or contraindicated in liver transplant patients. For this reason, percutaneous transhepatic electrohydraulic lithotripsy (EHL) was performed using an 11 French flexible ureteroscope in two pediatric patients who developed biliary tract calculi following orthotopic liver transplant. There were no complications and postoperative follow-up over 4 years has been uneventful. To our knowledge, these represent the first reported cases of percutaneous transhepatic endoscopic EHL to fragment biliary tract stones in a transplanted liver, which for us has been a safe and effective therapeutic option.

Changing indications for laparoscopic cholecystectomy. Stones without symptoms and symptoms without stones

In less than a decade, laparoscopic methods have dramatically improved the safety and convenience of cholecystectomy. As a result, the number of cholecystectomies performed nationwide has increased significantly. Whether this increase is a reflection of any major change in operative indications is unclear; the actual answer may vary from community to community. Silent gallstones continue to represent a sometimes contentious therapeutic dilemma. Because their natural history is unlikely to have changed, the management guidelines previously established for open cholecystectomy continue to have relevance today. Thus, it can be agreed that the majority of patients with silent gallstones do not require a cholecystectomy. The changing risk-benefit ratio suggests that some liberalization of these guidelines may now be in order. Already a number of transplantation surgeons have begun to recommend pretransplant cholecystectomy for asymptomatic patients who are found to have gallstones during screening. Available evidence also appears to support the use of pre-emptive laparoscopic cholecystectomy for other indications such as in selected women of childbearing age, young children, and patients with very large gallstones. The problem of silent gallstones in diabetics continues to be more enigmatic, but some complicated diabetics are probably best managed with operation. Other patient groups who are at high risk of having adverse outcomes from expectant management will be more precisely identified by future research efforts. Laparoscopic cholecystectomy should also be helpful in patients with various forms of acalculous biliary disease. However, special caution is advisable in approaching chronic acalculous cholecystitis until more specific and reproducible diagnostic methods are further validated.

Percutaneous cholecystolithotomy: risks, benefits, and long-term outcome

BACKGROUND

For symptomatic patients with gallbladder stones and a patent cystic duct who wish to retain their 'functioning' gallbladders, percutaneous cholecystolithotomy (PCCL) offers an alternative to open or laparoscopic cholecystectomy. However, there are few data on the risks and benefits of this approach or on the long-term outcome.

METHODS AND RESULTS

In 21 patients with symptomatic calcified gallstones, PCCL was successful (gallstone clearance) in 17 (81%). Four to 62 (median, 35) months after clearance 9 of the 17 remained symptom-free and stone-free, whereas 4 developed biliary sludge at 7, 30, 32, and 35 months, 2 of whom subsequently developed gallstones. In four other patients gallstones recurred without evidence of preceding biliary sludge at 9, 16, 19, and 27 months, corresponding to an actuarial gallstone recurrence rate at 36 months of 53.4 +/- SEM 15.1%, and a combined stone/sludge recurrence rate of 63.4 +/- 13.5%.

CONCLUSIONS

PCCL is moderately effective but, because of the frequency of complications and sludge/stone recurrence, is likely to have only a limited residual role in the era of laparoscopic cholecystectomy.

Definition and classification of negative outcomes in solid organ transplantation. Application in liver transplantation

OBJECTIVE

This study defined negative outcomes of solid organ transplantation, proposed a new classification of complications by severity, and applied the classification to evaluate the results of orthotopic liver transplantation (OLT).

SUMMARY AND BACKGROUND DATA

The lack of uniform reporting of negative outcomes has made reports of transplantation procedures difficult to interpret and compare. In fact, only mortality is well reported; morbidity rates and severity of complications have been poorly described.

METHODS

Based on previous definition and classification of complications for general surgery, a new classification for transplantation in four grades is proposed. Results including risk factors of the first 215 OLTs performed at the University of Toronto have been evaluated using the classification.

RESULTS

All but two patients (99%) had at least one complication of any kind, 92% of patients surviving more than 3 months had grade 1 (minor) complications, 74% had grade 2 (life-threatening) complications, and 30% had grade 3 (residual disability or cancer) complications. Twenty-nine per cent of patients had grade 4 complications (retransplantation or death). The most common grade 1 complications were steroid responsive rejection (69% of patients) and infection that did not require antibiotics or invasive procedures (23%). Grade 2 complications primarily were infection requiring antibiotics or invasive procedures (64%), postoperative bleeding requiring > 3 units of packed red cells (35%), primary dysfunction (26%), and biliary disease treated with antibiotics or requiring invasive procedures (18%). The most frequent grade 3 complication was renal failure, which is defined as a permanent rise in serum creatinine levels > or = twice the pretransplantation values (11%). Grade 4 complications (retransplantation or death) mainly were infection (14%) and primary dysfunction (11%). Comparison between the first and last 50 OLTs of the series indicates a significant decrease in the mean number of grade 1 and 2 complications. This was partially a result of better medical status of patients at the time of transplantation. Using univariate and multivariate analyses of risk factors, the best predictor of grade 1 complications was donor obesity; for grade 2 complications, the best predictor was a donor liver rewarming time of > 90 minutes, and for grade 3 and 4 complications, the best predictor was the APACHE II scoring system and donor cardiac arrest.

CONCLUSIONS

Standardized definitions and classifications of complications of transplantation will allow us to better evaluate and compare results of transplantation among centers and over time, and better compare effectiveness of new therapies. Orthotopic liver transplantation still is a procedure with high morbidity that requires careful analysis of risk factors to optimize selection of patients and organ sharing.

Recent advances in the management of gallstones

Demands for less invasive, more cost-effective therapy have revolutionized the management of gallstones over the past 10 years. There are no reliable methods of permanently reversing the pathophysiologic defects that cause gallstones. Open cholecystectomy (OC), the gold standard for managing symptomatic cholelithiasis, has been largely replaced by laparoscopic cholecystectomy (LC), which has the advantages of a minimal hospital stay and quicker return to work. Other adjunctive therapies, limited in applicability to selected patients, include oral bile acid therapy (BAT), dissolutional agents, and extracorporeal shock wave lithotripsy. Choledocholithiasis (CDL), formerly managed exclusively with surgical common duct exploration, is increasingly treated with therapeutic biliary endoscopy. Methods of laparoscopic common bile duct exploration are being developed. Optimal algorithms for applying these techniques to patients undergoing LC are evolving. In a sense, the solution to all, or certainly most, gallstones now can be seen through a scope.

Overview of therapeutic modalities for the treatment of gallstone diseases

The management of gallstone diseases has been revolutionized in less than 2 years by the advent of laparoscopic cholecystectomy (LC). However, the rapid adoption of LC has occurred without comparative randomized trials with other available therapies. Thus, the evaluation of LC versus other therapies can only be based on case series. The criteria used for this evaluation are clinical effectiveness, cost-effectiveness, and the patient's level of acceptance and satisfaction with the procedure. The techniques of both LC and open cholecystectomy (OC) have the advantage over other approaches, such as extracorporeal shock-wave lithotripsy or bile acid therapy, of eliminating not only the gallstones but also the gallbladder, thereby preventing recurrence of the disease. Additionally, medical therapies are effective in only a subgroup of patients. Since the complications of surgery are more frequent and more severe in older patients and, due to life expectancy, the risk of recurrence is lower in this population, cost-effectiveness analyses have shown that medical therapies may be preferable in older patients in the subgroup eligible for the respective medical therapies. Compared with OC, LC results in a reduction in hospital stay and time to return to work, in lower cost, and in higher patient satisfaction with the procedure. However, a major concern with the laparoscopic approach has been an increase in the incidence of bile duct injury, particularly during the learning phase of the procedure. Clearly, this problem must be solved. The development of training courses in laparoscopy and the adoption of rigorous criteria for ductal identification are critical in preventing such injuries. Bile duct injury can probably be reduced at least to the level of OC (about 1 in 1,000). Acute cholecystitis may also be treated by LC, but the safety and timing of surgery should be conclusively evaluated. Patients with gallbladder stones and choledocholithiasis are usually treated by endoscopic sphincterotomy either before or soon after laparoscopic surgery. Laparoscopic techniques of common bile duct exploration that will obviate the need for endoscopic sphincterotomy are in the developmental stages. When such a technique is available, comparative trials with endoscopic sphincterotomy will be necessary to assess the best approach.

Primary and secondary prevention of gallstone disease: implications for patient management and research priorities

Primary prevention is defined as the prevention of gallstone formation; secondary prevention is defined as the prevention of clinical manifestations of gallstones--symptoms or more severe complications. For primary prevention, general "wellness" measures can be recommended from a theoretic standpoint. These include elimination of obesity (to decrease excessive cholesterol biosynthesis or mobilization of tissue cholesterol during rapid weight loss); a high-fiber, high-calcium diet (to diminish input of deoxycholic acid); ingestion of meals at regular intervals (to diminish gallbladder storage and interruption of the enterohepatic circulation of bile acids); and vigorous exercise (to permit frequent meals without excessive caloric intake). In addition, based on animal studies, intake of low saturated fatty acids may diminish the nucleation of supersaturated bile. Secondary prevention is recommended only when gallstones become symptomatic because of the benign natural history of asymptomatic gallstones, the intrinsic limitations of medical therapy, and the absence of predictors that would enable selection of asymptomatic patients at high risk for becoming symptomatic. Secondary prevention involves nonsurgical approaches (dissolution with ursodiol, extracorporeal shock-wave lithotripsy plus adjuvant bile acids, and, rarely, contact dissolution with organic solvents). For patients with symptomatic gallstones, nonsurgical therapy will be used by those patients who cannot or will not have surgery, as well as those patients who wish to explore a trial of nonsurgical therapy before having surgery. Because of the intrinsic limitations of nonsurgical therapy in comparison to the efficacy and safety of surgery, most patients will undergo surgery. Future research priorities include elucidation of factors responsible for: (1) bile that is supersaturated in cholesterol; (2) elevated biliary deoxycholic acid levels in patients with cholesterol gallstones; (3) rapid nucleation in patients with multiple cholesterol gallstones; (4) precipitation of calcium bilirubinate; and (5) impaired gallbladder motility in gallbladder stone disease.

Efficacy of bile acid therapy for gallstone dissolution: a meta-analysis of randomized trials

To define better the efficacy of bile acid therapy for dissolution of radiolucent gallstones, we performed a meta-analysis of published trials from January 1966 to September 1992. Studies were identified using a MEDLINE computer search followed by an extensive manual search. The inclusion criteria used were: randomized trial, radiolucent gallstones in a visualizing gallbladder on oral cholecystography, and complete stone dissolution confirmed by oral cholecystography or ultrasound. Study results were pooled into 6 groups: placebo: high- and low-dose chenodeoxycholic acid (CDCA) (> or = 10 mg.kg/day and < 10 mg.kg/day); high- and low-dose ursodeoxycholic acid (UDCA) (> or = 7 mg.kg/day and < 7 mg.kg/day) and combined CDCA plus UDCA. Homogeneity calculations were performed and the percentage of complete stone dissolution calculated for each group with 95% confidence intervals. Of 66 trials identified, 23 comprising 1949 patients met the inclusion criteria. A total of 1062 patients were treated with CDCA, 819 with UDCA and 78 combination therapy. In studies > 6 months' duration, high-dose UDCA completely dissolved stones in 37.3% of patients (95% C.I. 33-42%), low-dose UDCA in 20.6%) and high-dose CDCA 18.2% (95% C.I. 15-21%). Based on only two studies, combination therapy achieved dissolution in 62.8% (95% C.I. 51-74%) of patients. Stones less than 10 mm dissolved significantly more frequently than stones larger than 10 mm. This analysis shows that UDCA in doses greater than 7 mg.kg/day taken for greater than 6 months will dissolve radiolucent gallstones in 38% of patients. The combination of UDCA and CDCA may be more efficacious but this observation is based upon only 78 patients and requires confirmation in further randomized trials.

Recent results of elective open cholecystectomy in a North American and a European center. Comparison of complications and risk factors

Results of elective open cholecystectomy in 1252 patients treated in a North American and a European center were examined using a recent standardized classification of complications. Although there were significant differences between centers in population age, rate of concomitant disorders, and numbers of operators, the frequency and severity of complications were comparable. There were no deaths, but 12% and 14% of the patients developed complications in the two centers. About 6% of the patients developed grade I complications. Grade II complications were noted in 6% and 8%, and grade III in 0% and 0.3%. Using univariate and multivariate analysis, individual risk factors for developing complications were found to be different in the two centers. Two preoperative scoring systems, ASA and a simplified APACHE II, were predictive for complications in both centers, but did not account for all risk in these patients. Data from the two centers could not be combined because of significant interaction between risk factors and center. Elective open cholecystectomy is a safe procedure, particularly in terms of highly morbid complications and death. Generalization of risk factors identified in a particular center may be misleading because local conditions may significantly affect risk factors for complications. The data also demonstrate the advantages of a uniform way of reporting surgical complications, which may permit meaningful comparisons among centers.