Laparoscopic Cholecystectomy in a Single,Non-teaching Hospital: An Analysis of 1557 Patients

Abstract

Background:

Laparoscopic cholecystectomy may lead to serious complications, although it is the gold standard treatment for gallstones. In this article, the aim was to review our experience with laparoscopic cholecystectomies.

Subjects and Methods:

All laparoscopic cholecystectomies were performed in a single, non-teaching hospital between January 2000 and October 2010 and were reviewed retrospectively to analyze the effect of preoperative risk factors on outcome and the associated major complications.

Results:

This study included 1557 laparoscopic cholecystectomies, and the mean age of the patients was 54.1±12.3 years. The mean duration of the operation and the mean length of stay were 43.4 minutes and 1.2 days, respectively. Conversion to an open cholecystectomy was necessary in 39 patients, and thus the conversion rate was 2.5%. In total, 57 (3.7%) complications occurred in 51 patients. Serious common bile duct injury was seen in 4 (0.27%) cases. The other common complications included bile leakage in 10 (0.64%) and postoperative bleeding in 7 (0.45%) patients. The mortality rate was 0.13%. Risk factors for conversion to open surgery were male gender, age >55 years, emergency admission due to acute cholecystitis, and a history of previous acute cholecystitis attacks. Factors that increased the morbidity rate were male gender, an American Society of Anesthesiologists score of III, emergency admission due to acute cholecystitis, and a history of previous acute cholecystitis attacks.

Conclusions:

Our results may serve as a baseline for comparison with future studies done at single, non-teaching hospitals where surgical teams perform laparoscopic cholecystectomies over a long period of time.

Introduction

Laparoscopic cholecystectomy (LC) is considered to be the gold standard for the treatment of gallstones.^1–3 In the previous literature, the rate of bile duct injuries, conversion rates, length of stay (LOS), and morbidity and mortality rates have been used as measurements of LC outcome.^4,5 The outcome usually depends on preoperative risk factors such as age, gender, body weight, clinical presentation, previous upper abdominal surgery, hospital and surgeon volumetric data, and whether the surgery was performed at a teaching or non-teaching hospital.^3,6–11

Despite numerous clinical studies on several aspects of LC, most reports either have been collective reviews of different studies performed by many surgeons and institutions or single-institution reports with many different surgeons.^3,12–18 Thus, clinical studies from one institution and a single general surgery group with homogeneous surgeon volumetric data would be beneficial because this type of study would decrease the effect that some uncontrolled parameters, such as varations in technique, personal preferences, equipment, and operating room/hospital settings, have on outcomes.^3,7,12

The higher complication rate of LC performed in non-teaching hospitals is a cause for speculation in the previous literature.^6,8 It has been suggested that the lower complication rate in teaching hospitals, particularly the lower rate of bile duct injuries, is due to the presence of a second surgeon. As a result, these studies suggested that it is safer to perform LC at hospitals with surgical residency programs.¹¹ However, in a recent cohort analysis, it was found that the bile duct injury rates were not influenced by the presence of such programs.⁹ So, there is a need for further clarification of this issue by future studies.

In this article, we retrospectively reviewed our cumulative experience performing LC in a non-teaching hospital and analyzed the effect of preoperative risk factors on outcome and the associated major complications.

Subjects and Methods

All LC operations were performed at The Religious Foundation of Turkey, 29 May Hospital, Istanbul, Turkey, between January 2000 and October 2010 and were reviewed retrospectively. Institutional Review Board approval was obtained from the hospital.

The data used in this study were retrieved from medical records kept in the hospital information system by searching using the appropriate codes found in the International Classification of Diseases, 9^th revision, Clinical Modification, and included “laparoscopic cholecystectomy (51.23),” “laparoscopic partial cholecystectomy (51.24),” or “open cholecystectomy (51.22) with laparoscopic surgical procedure converted to open (V 64, V64.41).” Patients with incomplete data were excluded.

Preoperatively, all patients had undergone at least one abdominal ultrasound (LOGIQ^® 9, GE Healthcare, Milwaukee, WI), performed by one of the radiologists at the hospital, to confirm the presence of gallstones and the biliary origin of the symptoms. After the diagnosis of cholelithiasis was made and patients were scheduled for surgical removal of the gallbladder, an anesthesiology consultation was performed, and the American Society of Anesthesiologists (ASA) Physical Status Classification score was recorded preoperatively for each patient.

Prior to the surgery, the patient's history was obtained, and routine tests, including chest radiography, and standard laboratory blood tests (complete blood count, urea and creatinine levels, electrolytes, and liver function tests) were carried out. The data collected included patient demographics (age, gender, and body mass index [in kg/m²]), history of previous acute cholecystitis (AC), acute biliary pancreatitis, upper abdominal surgeries, the preoperative ASA score, and whether admission to the hospital was elective or emergency.

A diagnosis of previous AC required an intraoperative finding of a thick-walled fibrotic gallbladder with adhesions in patients who were hospitalized and treated with antibiotics due to AC. These diagnostic criteria for AC were based on the Tokyo diagnostic criteria.¹⁹ We adopted a policy of immediate surgery during initial hospitalization in all patients who presented with AC.

In order to be classified as having previous, acute, biliary pancreatitis, patients had to be hospitalized within 3 months prior to LC and have had findings of upper abdominal pain of biliary origin and elevated serum amylase levels after the exclusion of other possible diagnoses.

Preoperative endoscopic retrograde cholangiopancreatography (ERCP) with sphincterotomy and stone extraction were performed when the presence of common bile duct (CBD) stones was confirmed by imaging. Intraoperative cholangiography was not used because of the selective use of ERCP. In cases in which there were elevated serum bilirubin levels without documented CBD stones, conservative management was used first, and further, more invasive management decisions were made based on laboratory findings.

Each LC operation was performed by one of the surgeons (M.H. and M.U.), who had already completed almost 100 LC operations prior to the study. During the operation, the surgeon held the dissector and grasper, and a scrub nurse held the camera that was an end-viewing 0° laparoscope and the retracting grasper. Thus, the surgeries included in this study were performed by a solo operator with a scrub nurse. A pneumoperitoneum was established using the closed method with a Veress needle, except for in patients who had undergone previous upper abdominal surgery via midline incision. In these patients, the open technique was used. In cases of gallbladder perforation and/or spillage of stones, extensive peritoneal lavage was performed.

Antibiotic prophylaxis was only used in patients with AC. Prophylaxis for venous thromboembolism was used in patients with a moderate or higher risk according to the Caprini risk assessment scale.²⁰

The outcome measures were conversion to open surgery, duration of the operation, LOS, and complications that occurred during the same admission or over a period of 3 months. The duration of the operation was calculated from the time of insertion of the first trocar to the time of skin closure with the last trocar. The LOS was defined as the number of days from the day of the operation until hospital discharge or death. The Strasberg classification was used for bile duct injuries^4,7,21,22 (Table 1).

Table 1.

Strasberg Classification of Bile Duct Injuries

Type	Definition
Type A	Bile leak from cystic duct or liver bed without injury
Type B	Partial occlusion of the biliary tree, most frequently from an aberrant right hepatic duct
Type C	Bile leak from duct (aberrant right hepatic duct) that is not communicating with the common bile duct
Type D	Lateral injury of the biliary system, without loss of continuity
Type E	Circumferential injury of the biliary tree with loss of continuity

Postoperatively, all patients were followed up for at least 3 months. After that interval, the patient was instructed to contact our department, if necessary.

Statistical calculations were performed using NCSS (Number Cruncher Statistical System) (2007) and PASS (Power Analysis and Sample Size) (2008) statistical software (both from NCSS, LLC, Kaysville, UT). Normally distributed continuous variables were expressed as mean±standard deviation values, and variables without a normal distribution were expressed as median and ranges. Categorical variables were expressed as frequencies and percentages. Student's t test was used for comparison of continuous parametric variables. In order to analyze the probability of complications according to gender, a chi-squared test was used. A multiple regression analysis for dichotomous variables (conversion and complications) and a linear regression model for continous variables (duration of the operation and LOS) were used. The statistical results were presented as an odds ratio (OR) with a 95% confidence interval. The differences were considered statistically significant if the P value was ≤.05.

Results

During the study period, LC was attempted in 1676 patients. Because of incomplete data, 119 cases were excluded. Thus, the total number of LC patients included in the study was 1557 (mean age, 54.1±12.3 years; range, 14–97 years). The demographic characteristics of the patients are given in Table 2.

Table 2.

Characteristics of Patients Undergoing Laparoscopic Cholecystectomy According to Gender

Characteristic	Total	Female	Male
Number	1557	1222	335
Age (years)	54.1±12.3	53.4±12.2	56.7±12.4
Female/male ratio	3.65
BMI (kg/m²)
<25	195 (12)	141	54
25–29.99	589 (38)	381	208
30–34.99	586 (38)	530	56
35–39.99	142 (9)	127	15
>40	45 (3)	43	2
ASA score
I	642 (41)	512	130
II	868 (56)	685	183
III	47 (3)	25	22
Mode of admission
Elective	1401 (90)	1114	287
Emergency	156 (10)	108	48
Previous AC attack	191 (12)	125	66
Previous acute biliary pancreatitis	34 (2)	25	9
Previous upper abdominal surgery	66 (4)	39	27

Data are number of patients, number of patients (%), or mean±standard deviation values as shown.

AC, acute cholecystitis; ASA, American Society of Anesthesiologists; BMI, body mass index.

Conversion to open cholecystectomy was necessary in 39 patients, and thus there was a conversion rate of 2.5%. Severe inflammation due to AC and previous AC attacks were the most common reasons for conversion and were found in 17 (43.5%) and 15 (38.5%) of the 39 patients who needed conversion, respectively. The other reasons for conversion included bile duct injury (n=3), dense adhesions due to previous surgery (n=2), and equipment failure (n=2).

The mean duration of operation was 43.4 minutes and ranged from 10 to 200 minutes. In 85.8% of the patients, the operation was completed in less than 60 minutes. The mean LOS was 1.2 (median, 1; range, 1–19) days. Within 1 day of the surgery, 93.1% of patients were discharged; within 2 days of the surgery, 94.8% were discharged.

In total, 57 (3.7%) complications occurred in 51 patients, and of these patients, 35 were female, and 17 were male (Table 3).

Table 3.

Postoperative Complications and Their Management

Complication	n (%) or n	Management
Bile duct injury	4 (0.27)
Complete transection of CBD	1	Conversion, Roux-en-Y hepaticojejunostomy
Injury to right aberrant hepatic duct	1	Conversion, primary suture
Cystic duct–CBD junctional injury	2	Conversion, primary suture over a T-tube
Biliary leakage	10 (0.64)
Controlled	3	Conservative
From liver bed	3	Laparotomy due to peritonitis, primary suture
From cystic stump	4	Laparotomy due to peritonitis, ERCP in one case
Retained stones in CBD	6 (0.39)	Endoscopic stone removal via ERCP
Bleeding	7 (0.45)
From liver bed	6	Laparotomy in 4, conservative in 2
From umblical trocar port	1	Primary hemostasis
Postoperative paralytic ileus	6 (0.39)	Conservative
Postoperative ascites	4 (0.27)	Conservative
Infection-related complications	11 (0.7)
Subdiaphragmatic infection	5	Percutaneous abscess drainage
Wound infection	5	Local treatment
Urinary tract infection	1	Medical treatment
Trocar injury to small bowel mesentery	1	Ischemic changes, resection and anastomosis via umbilical incision
Port sinus	1	Local treatment
Duodenal fistula	1	Conservative
Cardiopulmonary complications	4	Pulmonary embolism in 2, cardiac arrhythmias in 2
Others	2	Endoscopic treatment for upper GI bleeding, surgery for perforation of peptic ulcer

CBD, common bile duct; ERCP, endoscopic retrograde cholangiopancreatography; GI, gastrointestinal.

Of the 1557 attempted LC procedures, there were 4 (0.27%) cases of serious CBD injury that were discovered intraoperatively. A complete bile duct transection (Strasberg type E) was performed in 1 case. The injury, which was located just above the junction of the cystic and common hepatic duct, was discovered intraoperatively. After conversion to open surgery, the injury was managed with a Roux-en-Y hepaticojejunostomy. The patient was discharged on postoperative Day 7 without any further complication. In another case, after conversion to open surgery because of chronic severe inflammation, a small injury to the right aberrant hepatic duct was noticed (Strasberg type D) and repaired with a primary suture. Cystic duct–CBD junctional injury (Strasberg type D) occurred intraoperatively in another 2 cases; both cases were repaired primarily using a T-tube after conversion to open surgery. The patients were discharged uneventfully.

In 10 patients (0.64%), bile leakage was detected in the first week following LC. The leak spontaneously resolved without any intervention in 3 patients. However, 7 patients had to receive a laparotomy because of peritonitis. The origin of the bile leakage was the liver bed (Strasberg type A) in 3 patients, and a primary suture was enough to stop the leakage. In 4 patients, leakage from the cystic duct stump (Strasberg type A) was seen due to ischemic necrosis in an AC patient causing disruption of the stump (n=1) and slippage of the clips (n=3). Sutures were sufficient to initially control the cystic duct leakage in all patients, but an endoscopic sphincterotomy and biliary stent insertion were required because of a persistent bile fistula 2 weeks later in 1 patient. The mean LOS for these patients was 3.4 days with a range of 1–9 days.

Postoperative bleeding was detected in 7 (0.45%) cases. Four patients underwent a laparotomy to control bleeding, whereas the remaining 3 patients were managed conservatively. There was retention of the CBD stones in 6 (0.39%) patients. The diagnosis was made in the first 2 postoperative months, and an ERCP with sphincterotomy was successful in all patients.

There was one in-hospital and one perioperative death (0.13%) among the patients in this study. The former case received an operation due to AC, and on postoperative Day 3, the patient died because of severe respiratory distress secondary to pulmonary embolism. The latter patient was hypertensive and was first treated for post-ERCP pancreatitis, and an LC was performed for an AC 1 week later. He was discharged at postoperative Day 3 uneventfully; 2 days later, he died of a sudden myocardial infarction.

Analysis of the perioperative risk factors revealed that body mass index, history of previous upper abdominal surgery, and a history of previous acute biliary pancreatitis were not associated with conversion to open surgery and development of complications. However, male gender (OR=4.473, P<.001), age >55 years (OR=2.478, P<.01), emergency admission due to AC (OR=558.263, P<.001), and a history of previous AC attacks (OR=4.766, P<.001) were associated with a higher probability of conversion to open surgery. Male gender (OR=1.813, P<.046), an ASA score of III (OR=3.706, P<.005), emergency admission due to AC (OR=7.034, P<.001), and a history of previous AC attacks (OR=3.378, P<.001) were associated with a higher risk of morbidity.

The mean duration of the operation and the LOS in the patients in whom LC was converted to open surgery (n=39, 83.7 minutes) and in patients who experienced any complication (n=51, 60.8 minutes) were significantly higher than in patients in whom LC was completed (n=1518, 41.5 minutes) and no complication developed (n=1506, 60.8 minutes), respectively (P<.001 for all comparisons).

Discussion

Since the technique was first introduced by Muhe in 1985, LC has now been accepted as the standard surgical treatment for gallstones.^3,12 Although there are some controversies about the safety and applicability of LC in complicated gallstone diseases such as AC and in patients with a previous AC attack and previous upper abdominal surgery, LC can be safely used in these circumstances by experienced surgeons.^3,23–26

Many studies concerning LC are from institutions, specialized centers, or teaching hospitals in which LC operations were performed by many different surgeons.^3,12–18 Although these studies have the advantage of an abundant availability of specific clinical information, within the study there are often significant variations in several aspects such as technique, personal preferences, equipment, and operating room/hospital settings.^3,7,12 Also, there are some reports that question the use of LC in non-teaching hospitals because of the high rates of conversion and complication.^6–9,11 This is one of the largest studies on LC coming from a single, non-teaching hospital.

The complication rate after LC varies from 1.5% to 17%, depending on several factors such as the presence of complicated gallstone disease, an ASA score of 3 or more, male gender, advanced age, acute admission, conversion to open surgery, operations lasting more than 2 hours, and LC performed in non-teaching hospitals.^{3,4,6,8,12,14,24,27,28} It has been suggested that it is impossible to compare the overall complication rates because of the tremendous variability in the previous literature.⁶ Our 3.7% complication rate may be considered a favorable result compared with the 1.5–17% complication rate found in the past literature.^{3,8,12,14,27,28}

It was speculated that major CBD injuries were due to faulty visual perception and that CBD injuries could be prevented by a second set of critical eyes in the operating room (by using a first assistant surgeon, for instance).^7,15 Thus, one might expect to see an increased rate of CBD injury with the use of single-incision LC since it has been promoted as a way to minimize the surgical team.⁷ In the present study, in which most of the operations were performed by a solo operator with a scrub nurse, there was a 0.27% CBD injury rate. Thus, our results may serve as a baseline for comparison for future single incision operations.

The presence of specific features of laparoscopic operations such as conversion to open surgery and the possible high complication rates, especially CBD injury, in comparison with open cholecystectomy are important issues that should be clarified. It has been accepted that conversion from LC to open surgery is not a complication and is instead a safe completion of a surgical procedure for both the surgeon and the patient.^3,8 The etiology for conversion includes severe inflammation and/or dense adhesions causing difficulty in dissecting the Calot triangle.^8,13,15,20 There are many risk factors for conversion that have been previously reported, including advanced age, male gender, severe AC, previous upper abdominal surgery, obesity, CBD stones with previous endoscopic sphincterotomy and severe cardiopulmonary diseases, or a high ASA score.^{4,10,16,18,23,24,28–30} The rate of conversion in patients with AC, previous upper abdominal surgery, and a high ASA score has been reported to be almost 25%, according to the national database of some countries.^12,18 In the literature, the overall rates for conversion vary between 1.5% and 19% depending on the target patient populations and the associated risk factors for conversion.^{3,4,6,14,18,23,24,29} However, in the current study, severe AC and previous AC attacks were associated with conversion rates of 9% and 7.9%, respectively, which is in accordance with one study coming from a single center.³ Our overall conversion rate of 2.5% was a favorable outcome considering that the AC rate was 10% and the rate of previous AC attacks was 12% in the patients in this study. These favorable results may be due to the fact that only consultant surgeons were involved in the operations described in this study, whereas in many studies, the operations are performed by both consultant and training surgeons.

Bile duct injury during LC is the most serious procedure-related complication with an incidence rate of between 0.1% to 2.35%.^{13,14,29–32} The incidence decreases to 0.17%–0.3% as surgical experience increases.^3,30,33,34 It is associated with significant perioperative morbidity and mortality, reduced long-term survival and quality of life, and high rates of subsequent litigation.²² Immediate detection and repair primarily with an appropriate surgical technique either laparoscopically or after conversion to open surgery are the most important steps to prevent ongoing morbidity.^15,29,33 When complete transection of the CBD occurs, the Roux-en-Y choledocho- or hepaticojejunostomy is the operation of choice and was used in one of the cases in the current study.^{13,20,29–31} When partial defects in the duct are present, primary closure with subhepatic drainage is the best treatment option. However, it is also possible to close the defects using a T-tube.²² In this study, we performed primary closure in 1 patient with a small injury to the right aberrant hepatic duct and primary closure using a T-tube in 2 patients with cystic duct–CBD junctional injury. Although postoperative bile leakages from the liver bed or the stump of the cystic duct has not been defined as bile duct injury,^10,13,30,31 the usage of classification systems that include all injuries may be helpful in order to simplify the categorization of injuries and comparison with other results.^4,22

Bile leakage usually occurs from the liver bed or the stump of the cystic duct (Strasberg type A) and is one of the most common complications directly related to LC.^1,15 The incidence of bile leakage varies from 0.2% to 4%.^{13–15,34,35} The cystic duct stump and small peripheral right hepatic ducts within the liver bed account for most of this type of injury.^26,34 Cystic duct leaks can occur from faulty clip application, slippage of the clips, or necrosis of the cystic duct stump proximal to the clip and are probably related to thermal injury or acute or chronic inflammation.^22,34,36 Although drainage and endoscopic sphincterotomy with a biliary stent insertion are succesful in most cases, the development of biliary peritonitis with a high output fistula may necessitate a laparoscopy or a laparotomy.^15,22,34,35 In this study, the leakage resolved spontaneously without any intervention in 3 of the 6 patients who had drains placed intraoperatively. In the remaining 3 patients with the intraoperative drain as well as 4 patients without a drain, the leakage did not resolve spontaneously. A laparotomy was necessary in these 7 patients, who had a Strasberg type A injury, in order to treat biliary peritonitis caused by a high-output fistula. Because ERCP is not available in our center and because the patients presented with severe biliary peritonitis, laparotomy was necessary rather than endoscopic sphincterotomy with a biliary stent insertion and percutaneous drainage.

With regard to safety, in this study there was a 0.27% incidence of CBD injury, a 3.7% overall complication rate, and a 0.13% incidence of mortality, and these findings are compatible with similar, previous studies.³

There are several limitations in this study, including the retrospective design and inability to obtain complete data on almost 10% of patients who received an LC by the same surgical team in this hospital.

In conclusion, our results may serve as a baseline for comparison for future studies that involve LC performed by surgical teams in a single, non-teaching institution over a long period of time.

Footnotes

Disclosure Statement

Each author certifies that he has no competing financial or commercial associations (e.g., consultancies, stock ownership, equity interest, patent/licensing arrangements, etc.) or other relationships with commercial parties that might pose a conflict of interest in connection with the submitted article.

References

Palanivelu

, Jani

, Maheshkumar

. Single-center experience of laparoscopic cholecystectomy. J Laparoendosc Adv Surg Tech A, 2007; 17:608–614.

Lirici

, Califano

. Management of complicated gallstones: Results of an alternative approach to difficult cholecystectomies. Minim Invasive Ther Allied Technol, 2010; 19:304–315.

Konstadoulakis

, Antonakis

, Karatzikos

, Alexakis

, Leandros

. Intraoperative findings and postoperative complications in laparoscopic cholecystectomy: The Greek experience with 5,539 patients in a single center. J Laparoendosc Adv Surg Tech A, 2004; 14:31–36.

Veen

, Bik

, Janssen-Heijnen

, De Jongh

, Roukema

. Outcome measurement in laparoscopic cholecystectomy by using a prospective complication registry: Results of an audit. Int J Qual Health Care, 2008; 20:144–151.

Kanakala

, Borowski

, Pellen

, Dronamraju

, Woodcock

, Seymour

, Attwood

, Horgan

. Risk factors in laparoscopic cholecystectomy: A multivariate analysis. Int J Surg, 2011; 9:318–323.

Murphy

, Shah

, Simons

, Csikesz

, McDade

, Bodnari

, Ng

, Zhou

, Tseng

. Predicting major complications after laparoscopic cholecystectomy: A simple risk score. J Gastrointest Surg, 2009; 13:1929–1936.

Martin

, Earle

. Does a surgeon as first assistant reduce the incidence of common bile duct injuries during laparoscopic cholecystectomy? Am Surg, 2010; 76:287–291.

Murphy

, Ng

, Simons

, Csikesz

, Shah

, Tseng

. Predictors of major complications after laparoscopic cholecystectomy: Surgeon, hospital, or patient? J Am Coll Surg, 2010; 211:73–80.

Harrison

, Dolan

, Pham

, Diggs

, Greenstein

, Sheppard

, Hunter

. Bile duct injury after laparoscopic cholecystectomy in hospitals with and without surgical residency programs: Is there a difference? Surg Endosc, 2011; 25:1969–1974.

10.

Al-Mulhim

. Male gender is not a risk factor for the outcome of laparoscopic cholecystectomy: A single surgeon experience. Saudi J Gastroenterol, 2008; 14:73–79.

11.

Massarweh

, Devlin

, Symons

, Broeckel Elrod

, Flum

. Risk tolerance and bile duct injury: Surgeon characteristics, risk-taking preference, and common bile duct injuries. J Am Coll Surg, 2009; 209:17–24.

12.

Giger

, Michel

, Opitz

, Th Inderbitzin

, Kocher

, Krähenbühl

. Swiss Association of Laparoscopic and Thoracoscopic Surgery (SALTS) Study Group. Risk factors for perioperative complications in patients undergoing laparoscopic cholecystectomy: Analysis of 22,953 consecutive cases from the Swiss Association of Laparoscopic and Thoracoscopic Surgery database. J Am Coll Surg, 2006; 203:723–728.

13.

Mahatharadol

. Bile duct injuries during laparoscopic cholecystectomy: An audit of 1522 cases. Hepatogastroenterology, 2004; 51:12–14.

14.

Marakis

, Pavlidis

, Ballas

, Aimoniotou

, Psarras

, Karvounaris

, Rafailidis

, Demertzidis

, Sakantamis

. Major complications during laparoscopic cholecystectomy. Int Surg, 2007; 92:142–146.

15.

Triantafyllidis

, Nikoloudis

, Sapidis

, Chrissidou

, Kalaitsidou

, Chrissidis

. Complications of laparoscopic cholecystectomy: Our experience in a district general hospital. Surg Laparosc Endosc Percutan Tech, 2009; 19:449–458.

16.

Kaafarani

, Smith

, Neumayer

, Berger

, Depalma

, Itani

. Trends, outcomes, and predictors of open and conversion to open cholecystectomy in Veterans Health Administration hospitals. Am J Surg, 2010; 200:32–40.

17.

Ying

, Shuodong

, Hong

, Yang

, Jing

, Yu

, Amos

. Lessons learnt after 12 years experience in laparoscopic cholecystectomy at a single center. Hepatogastroenterology, 2010; 57:202–206.

18.

Harboe

, Bardram

. The quality of cholecystectomy in Denmark: Outcome and risk factors for 20,307 patients from the national database. Surg Endosc, 2011; 25:1630–1641.

19.

Hirota

, Takada

, Kawarada

, Nimura

, Miura

, Hirata

, Mayumi

, Yoshida

, Strasberg

, Pitt

, Gadacz

, de Santibanes

, Gouma

, Solomkin

, Belghiti

, Neuhaus

, Büchler

, Fan

, Ker

, Padbury

, Liau

, Hilvano

, Belli

, Windsor

, Dervenis

. Diagnostic criteria and severity assessment of acute cholecystitis: Tokyo Guidelines. Hepatobiliary Pancreat Surg, 2007; 14:78–82.

20.

Pannucci

, Bailey

, Dreszer

, Fisher Wachtman

, Zumsteg

, Jaber

, Hamill

, Hume

, Rubin

, Neligan

, Kalliainen

, Hoxworth

, Pusic

, Wilkins

. Validation of the Caprini risk assessment model in plastic and reconstructive surgery patients. J Am Coll Surg, 2011; 212:105–112.

21.

Fischer

. Is damage to the common bile duct during laparoscopic cholecystectomy an inherent risk of the operation? Am J Surg, 2009; 197:829–832.

22.

Lau

, Lai

, Lau

. Management of bile duct injury after laparoscopic cholecystectomy: A review. ANZ J Surg, 2010; 80:75–81.

23.

Thesbjerg

, Harboe

, Bardram

, Rosenberg

. Sex differences in laparoscopic cholecystectomy. Surg Endosc, 2010; 24:3068–3072.

24.

Botaitis

, Polychronidis

, Pitiakoudis

, Perente

, Simopoulos

. Does gender affect laparoscopic cholecystectomy? Surg Laparosc Endosc Percutan Tech, 2008; 18:157–161.

25.

Chang

, Lee

, Huang

, Chen

, Chiang

, Kuo

, Chuang

, Wang

, Ker

. The impact of body mass index on laparoscopic cholecystectomy in Taiwan: An Oriental experience. J Hepatobiliary Pancreat Surg, 2009; 16:648–654.

26.

Kholdebarin

, Boetto

, Harnish

, Urbach

. Risk factors for bile duct injury during laparoscopic cholecystectomy: A case-control study. Surg Innov, 2008; 15:114–119.

27.

Cheng

, Chang

, Liu

, Yang

, Jeng

, Lee

, Liu

. Factors associated with prolonged stay after laparoscopic cholecystectomy in elderly patients. Surg Endosc, 2008; 22:1283–1289.

28.

Chang

, Yu

, Hsieh

, Huang

, Lee

, Chen

, Kuo

, Chuang

, Wang

, Ker

. Laparoscopic cholecystectomy in aged patients. Hepatogastroenterology, 2009; 56:950–955.

29.

Chun

, Han

, Yoon

, Cho

, Kim

, Ahn

. Overcoming the difficulties encountered when performing laparoscopic cholecystectomy: Review of over one thousand laparoscopic cholecystectomies. Hepatogastroenterology, 2010; 57:398–402.

30.

Diamantis

, Tsigris

, Kiriakopoulos

, Papalambros

, Bramis

, Michail

, Felekouras

, Griniatsos

, Rosenberg

, Kalahanis

, Giannopoulos

, Bakoyiannis

, Bastounis

. Bile duct injuries associated with laparoscopic and open cholecystectomy: An 11-year experience in one institute. Surg Today, 2005; 35:841–845.

31.

Sicklick

, Camp

, Lillemoe

, Melton

, Yeo

, Campbell

, Talamini

, Pitt

, Coleman

, Sauter

, Cameron

. Surgical management of bile duct injuries sustained during laparoscopic cholecystectomy: Perioperative results in 200 patients. Ann Surg, 2005; 241:786–792.

32.

Downing

, Datoo

, Oyetunji

, Fullum

, Chang

, Ahuja

. Asian race/ethnicity as a risk factor for bile duct injury during cholecystectomy. Arch Surg, 2010; 145:785–787.

33.

Al-Kubati

. Bile duct injuries following laparoscopic cholecystectomy: A clinical study. Saudi J Gastroenterol, 2010; 16:100–104.

34.

Panpimanmas

, Ratanachuek

, Chantawiboon

. Endoscopic management of cystic duct stump leakage after cholecystectomy. Hepatogastroenterology, 2008; 55:1962–1964.

35.

Shaikh

, Thomas

, Joga

, Amin

, Daniel

. Post-cholecystectomy cystic duct stump leak: a preventable morbidity. J Dig Dis, 2009; 10:207–212.

36.

Tzovaras

, Peyser

, Kow

, Wilson

, Padbury

, Toouli

. Minimally invasive management of bile leak after laparoscopic cholecystectomy. HPB (Oxford), 2001; 3:165–168.