Abstract
Objective:
Characterize the determinants, all-cause mortality risk, and healthcare costs associated with common bile duct injury (CBDI) following cholecystectomy in a contemporary patient population.
Background:
Retrospective cohort study using nationwide patient-level commercial and Medicare Advantage claims data, 2003–2019. Beneficiaries ≥18 years who underwent cholecystectomy were identified using Current Procedure Terminology (CPT) codes. CBDI was defined by a second surgical procedure for repair within one year of cholecystectomy.
Methods:
We estimated the association of common surgical indications and comorbidities with risk of CBDI using logistic regression; the association between CBDI and all-cause mortality using Cox proportional hazards regression; and calculated average healthcare costs associated with CBDI repair.
Results:
Among 769,782 individuals with cholecystectomy, we identified 894 with CBDI (0.1%). CBDI was inversely associated with biliary colic (odds ratio [OR] = 0.82; 95% confidence interval [CI]: 0.71–0.94) and obesity (OR = 0.70, 95% CI: 0.59–0.84), but positively associated with pancreas disease (OR = 2.16, 95% CI: 1.92–2.43) and chronic liver disease (OR = 1.25, 95% CI: 1.05–1.49). In fully adjusted Cox models, CBDI was associated with increased all-cause mortality risk (hazard ratio = 1.57, 95% CI: 1.38–1.79). The same-day CBDI repair was associated with the lowest mean overall costs, with the highest mean overall costs for repair within 1 to 3 months.
Conclusions:
In this retrospective cohort study, calculated rates of CBDI are substantially lower than in prior large studies, perhaps reflecting quality-improvement initiatives over the past two decades. Yet, CBDI remains associated with increased all-cause mortality risks and significant healthcare costs. Patient-level characteristics may be important determinants of CBDI and warrant ongoing examination in future research.
Keywords: cholecystectomy, common bile duct injury, survival analysis
Mini-Abstract Common bile duct injury (CBDI) is a serious complication of cholecystectomy, necessitating technically demanding repair with associated reductions in survival and quality of life. This analysis examines potential determinants, all-cause mortality, and total healthcare costs associated with CBDI in a contemporary patient population.
INTRODUCTION
Cholecystectomy is the most common abdominal operation worldwide, with >750,000 operations performed in the United States each year.1,2 Laparoscopic techniques were first introduced in 1988, and anticipated reductions in postoperative pain and recovery time quickly established laparoscopic surgery as the standard of care for symptomatic cholecystitis.3–5 However, rates of biliary injury were noted to be substantially increased in laparoscopic versus open surgery.6–10 Whereas an injury to the common bile duct occurs in an estimated 0.1% to 0.2% of open cholecystectomies, the incidence in laparoscopic cholecystectomy was estimated in early series to be as high as 0.5%.11–13
Concerted quality-improvement initiatives have since reduced the incidence of CBDI in laparoscopic cholecystectomy.14,15 Yet, it remains a feared and devastating complication, often necessitating technically demanding repair and rehospitalization.16–18 CBDI is further associated with decreased life expectancy,17,19–22 diminished quality of life,23–26 delayed return to work, and decreased productivity.27 Litigation related to CBDI comprises 20% of all general surgery malpractice claims and roughly half of general surgery laparoscopic claims.12,14,28–31 Although numerous studies have focused on the incidence, costs, and mortality risk associated with CBDI, many are limited by small sample sizes given the relatively low numbers of CBDI that occur each year.14,32
Motivated by its profound consequences for both patients and practitioners, the present study aims to provide a detailed and comprehensive examination of CBDI requiring operative repair in a contemporary patient population. We leverage administrative data comprised of healthcare claims for >85 million privately insured individuals followed from 2003 to 2020. We specifically examine secular trends in the incidence of CBDI over the study period, demographic, and health-related determinants of CBDI, all-cause mortality risk associated with CBDI, and the relationship between time-to-repair and total cost among >700,000 patients who underwent cholecystectomy during the study period.
METHODS
Optum’s Clinformatics Data Mart Database is a large, de-identified commercial and Medicare Advantage claims database. Patient-level commercial claims data are available from January 1, 2003, to June 30, 2020. Member enrollment data; diagnostic codes from outpatient, emergency department, and inpatient visits; and pharmacy claims are deterministically linked across file types with a unique patient identifier.33 This study was approved by the Institutional Review Board at Stanford University (IRB-58527). This study is reported as per the Strengthening the Reporting of Observational Studies in Epidemiology (STROBE) guideline for cohort studies.
Study Design and Participants
We conducted a retrospective cohort study in which individuals were followed from 6 weeks before cholecystectomy (ie, their index surgery) until death, their last month of insurance eligibility, or the end of the study period on June 30, 2020. Individuals eligible for the present study were over the age of 18 years at the time they underwent cholecystectomy. We identified cholecystectomies using Current Procedure Terminology (CPT) codes 47562, 47563, 47564, 47600, 47605, 47610, 47612, and 47620. Individuals with history of hepatobiliary cancer, liver transplant, and Kasai procedure were excluded.
Common Bile Duct Injury
We identified common bile duct injury (CBDI) requiring operative repair using the following CPT codes: anastomosis of extrahepatic biliary ducts and gastrointestinal tract (47760); anastomosis of intrahepatic ducts and gastrointestinal tract, anastomosis (47765); anastomosis, Roux-en-Y of extrahepatic biliary ducts and gastrointestinal tract (47780); anastomosis, Roux-en-Y of intrahepatic biliary ducts and gastrointestinal tract (47785); and reconstruction of extrahepatic biliary ducts with end-to-end anastomosis (47800). Consistent with prior analysis by Flum and colleagues, we restricted our analysis to individuals who underwent repair within 1 year of the index surgery.13
All-Cause Mortality
We ascertained all-cause mortality using the date of death table, which contained month and year of death for deceased individuals ascertained through internal records and external sources. External sources included the Death Master File maintained by the Social Security Office and records from the Center for Medicare and Medicaid Services (CMS).34,35 We assigned date of death as the last day of the month.
Time-to-Repair, Total Cost, and Postoperative Costs
Time-to-repair was calculated as the number of days elapsed between the index surgery and repair of the common bile duct. We categorized time-to-repair as a same-day repair; occurring within 1 week; greater than 1 week but within 1 month; greater than 1 month but within 3 months; and more than 3 months after the index surgery. We calculated costs associated with repair of the common bile ducts using standard prices, which reflect allowed payments across all provider services and account for differences in pricing across health plans and provider contracts.36 We first calculated the sum of unique charges incurred from 7 days before the index surgery until 30 days after repair (total cost). This measure includes preoperative charges as well as costs incurred between cholecystectomy and subsequent repair of the common bile duct (ie, laboratory and radiologic studies, costs associated with inpatient hospitalizations). Second, we calculated the number of unique charges incurred from the date of repair until 30 days after (postoperative costs). We created an alternative measure of total costs in which we extended our calculations to the 90-day window after repair.
Patient-Level Covariates
We used diagnostic codes from the International Classification of Diseases, Ninth Revision (ICD-9) through October of 2015 and from the ICD-10 thereafter. We created a set of indicator variables that equaled one if members of the study population were diagnosed with any of the following in the 2 years before their surgery and zero otherwise: obesity, coronary artery disease, atrial fibrillation, chronic kidney disease, and chronic liver disease. We created a set of indicator variables that equaled one if members of the study population were diagnosed with any of the following surgical indications and zero otherwise: biliary colic, cholecystitis, other gallbladder disease, diseases of the pancreas, or cancers of the liver and biliary tree. We included indications for surgery diagnosed in the 3 weeks following surgery because in some cases conditions that existed before the index surgery may only have become apparent afterwards. By using indicator variables, we were able to identify multiple concurrent comorbid conditions and surgical indications for members of the study population. Diagnostic codes used to identify comorbidities and indications are included in Supplemental Table 1, http://links.lww.com/AOSO/A203.
We identified additional patient-level demographic characteristics from insurance eligibility files. These included sex (female or male), age, race/ethnicity, and calendar year. We used state of residence to assign US census regions (northeast, midwest, south, west).
Statistical Analysis
Our statistical analysis proceeded in four stages. First, we estimated the incidence of CBDI for each year of the study period. Next, we examined determinants of CBDI by estimating the associations of common indications for surgery and common comorbidities with CBDI among individuals undergoing cholecystectomy. We then examined the associations between CBDI and all-cause mortality. Finally, among individuals with CBDI, we examined the relationship between time-to-repair and average costs.
All statistical analyses were conducted using R version 4.0.0 (R Foundation for Statistical Computing, Vienna, Austria). We calculated 95% confidence intervals (CIs) with robust standard errors to account for repeated observations within states over time. Statistical inferences are presented based on alpha = 0.05.
Determinants of Bile Duct Injuries
We used generalized logistic regression to estimate adjusted odds ratios (ORs) for the association of indications for cholecystectomy and comorbidities of interest with CBDI. All models were adjusted for sex, race/ethnicity, age category, procedure type (open vs laparoscopic), and included a set of indicator variables for year of surgery and US Census region to account for secular trends and regional differences in provider networks, respectively. We first specified separate models for each indication and comorbidity in which we controlled for the above specified covariates. Next, we specified a single model that included all indications and comorbidities as well as sex, age category, procedure type, year, and region.
All-Cause Mortality and Bile Duct Injuries
We modeled time-to-death among individuals with and without CBDI using Cox proportional hazards regression. In survival analysis, follow-up extended from the date of cholecystectomy until death, loss-to-follow-up (ie, the end of insurance eligibility) or administrative censoring at the end of the study period on June 30, 2020. We first estimated the crude association between CBDI and all-cause mortality. Next, we estimated the association between CBDI and all-cause mortality controlling for sex, age category, race/ethnicity, region, and procedure type. Finally, we estimated the association between CBDI and all-cause mortality in which we further controlled for surgical indications and comorbidities. We conducted subgroup analyses by sex, race/ethnicity, age category, and region.
Time-to-Repair and Costs
Among individuals with injury to common bile duct, we estimated the mean 30- and 90-day costs by time-to-repair, accounting for sex, age category, race/ethnicity, US Census region, cholecystectomy, indications for surgery, and comorbidities.37,38
RESULTS
From 86,819,207 unique individuals, we identified 785,665 that underwent cholecystectomy during the study period. We excluded 122 individuals with unknown sex; 7715 individuals under the age of 18 at the time of cholecystectomy; 7919 individuals with history of Kasai procedure, liver transplant, or hepatobiliary cancer; and 137 individuals for whom more than 1 year elapsed between cholecystectomy and CBDI repair. This yielded a final sample size of 769,782 individuals (Supplemental Figure 1, http://links.lww.com/AOSO/A203).
Approximately two-thirds of the study population was female (68.5%) and white (65.9%), and more than half resided in the South (53.4%). Most procedures were performed laparoscopically (94.6%). The most common indication for surgery was cholecystitis (95.2%) and the most frequently diagnosed comorbidity was obesity (22.5%). We identified 894 individuals with CBDI, approximately 0.1% of individuals who underwent cholecystectomy. Among individuals with CBDI, nearly half were age 65 and older (43.3%) and male (48%), and more than half (54.6%) underwent open surgery (Table 1). The incidence of CBDI by year is depicted in Table 2. We observe the lowest incidence of CBDI in 2009 (0.09%) with a peak incidence in 2014 (0.15%). The incidence of cholecystectomy and the proportion of individuals with CBDI by state are depicted in Supplemental Figures 2 and 3, http://links.lww.com/AOSO/A203. Approximately half of CBDI were repaired on the same day as the cholecystectomy (50.4%) and more than two-thirds (72.9%) underwent repair within 3 weeks of cholecystectomy.
TABLE 1.
Demographic and Health Characteristics of Individuals Undergoing Cholecystectomy, 2003–2020*
| Overall | Bile Duct Injury | No Bile Duct Injury | |
|---|---|---|---|
| (N = 769,782) | (N = 894) | (N = 768,888) | |
| Sex | |||
| Female | 241,370 (31.4) | 465 (52.0) | 527,518 (68.6) |
| Male | 527,983 (68.6) | 429 (48.0) | 241,370 (31.4) |
| Age, y | |||
| 18–34 | 145,075 (18.8) | 87 (9.7) | 144,988 (18.9) |
| 35–44 | 138,540 (18.0) | 105 (11.7) | 138,435 (18.0) |
| 45–54 | 149,866 (19.5) | 140 (15.7) | 149,726 (19.5) |
| 55–64 | 128,805 (16.7) | 175 (19.6) | 128,630 (16.7) |
| 65+ | 207,496 (27.0) | 387 (43.3) | 207,109 (26.9) |
| Race/ethnicity† | |||
| Asian | 15,482 (2.0) | 29 (3.2) | 15,453 (2.0) |
| Black | 64,708 (8.4) | 85 (9.5) | 64,623 (8.4) |
| Hispanic | 94,577 (12.3) | 111 (12.4) | 94,466 (12.3) |
| White | 507,103 (65.9) | 565 (63.2) | 506,538 (65.9) |
| Region‡ | |||
| Midwest | 198,759 (25.8) | 183 (20.5) | 198,576 (25.8) |
| Northeast | 19,423 (2.5) | 23 (2.6) | 19,400 (2.5) |
| South | 410,746 (53.4) | 460 (51.5) | 410,286 (53.4) |
| West | 139,970 (18.2) | 226 (25.3) | 139,744 (18.2) |
| Type | |||
| Open | 36,667 (4.5) | 488 (54.6) | 36,179 (4.7) |
| Laparoscopic | 733,115 (95.2) | 406 (45.4) | 732,709 (95.3) |
| Indications for surgery§ | |||
| Biliary colic | 550,159 (71.5) | 553 (61.9) | 549,606 (71.4) |
| Cholecystitis | 698,948 (90.8) | 826 (92.4) | 698,122 (90.8) |
| Other gallbladder disease | 304,582 (39.6) | 500 (55.9) | 304,082 (39.5) |
| Diseases of the pancreas | 51,816 (6.7) | 182 (20.4) | 51,634 (6.7) |
| Comorbidities§ | |||
| Obesity | 173,797 (22.6) | 159 (17.8) | 173,638 (22.6) |
| Coronary artery disease | 103,940 (13.5) | 191 (21.4) | 103,749 (13.5) |
| Atrial fibrillation | 39,610 (5.1) | 106 (11.8) | 39,504 (5.1) |
| Chronic kidney disease | 48,446 (6.3) | 99 (11.1) | 48,347 (6.3) |
| Chronic liver disease | 116,367 (15.1) | 170 (19.0) | 116,367 (15.1) |
*Cholecystectomies were identified using CPT codes 47562, 47563, 47564, 47600, 47605, 47610, and 47620. Bile duct injuries were identified using CPT codes 47760, 47765, 47780, 47785, 47790, and 47800.
†Race/ethnicity was missing for 87,912 subjects (11.4%).
‡We defined US Census Regions as the Northeast (Connecticut, Massachusetts, Maine, New Hampshire, New Jersey, New York, Pennsylvania, Rhode Island, Vermont,); the South (Alabama, Arkansas, Delaware, District of Columbia, Florida, Georgia, Kentucky, Louisiana, Maryland, Mississippi, North Carolina, Oklahoma, South Carolina, Tennessee, Texas, Virginia, and West Virginia); the Midwest (Illinois, Indiana, Iowa, Kansas, Michigan, Minnesota, Missouri, Nebraska, North Dakota, Ohio, South Dakota, Wisconsin); and the West (Alaska, Arizona, California, Colorado, Hawaii, Idaho, Montana, Nevada, New Mexico, Oregon, Washington, and Wyoming).
§Common indications were identified in the six weeks prior and three weeks after the date of cholecystectomy. Comorbidities identified within the 365 days that preceded the date of cholecystectomy.
TABLE 2.
Number of Cholecystectomies Performed and CBDI Incidence, 2003–2020
| Year | Cholecystectomies | Laparoscopic | Open | CBDI | CBDI Incidence* |
|---|---|---|---|---|---|
| N | N (%) | N (%) | N | (95% CI) | |
| 2003 | 30,311 | 27,742 (91.5) | 2569 (8.5) | 36 | 0.119 (0.086–0.164) |
| 2004 | 30,997 | 28,766 (92.8) | 2231 (7.2) | 30 | 0.097 (0.068–0.138) |
| 2005 | 35862 | 33,575 (93.6) | 2287 (6.4) | 37 | 0.103 (0.075–0.142) |
| 2006 | 41,573 | 39,261 (94.4) | 2312 (5.6) | 41 | 0.099 (0.073–0.134) |
| 2007 | 43,285 | 41,056 (94.9) | 2229 (5.1) | 47 | 0.109 (0.082–0.144) |
| 2008 | 45,336 | 43,006 (94.9) | 2330 (5.1) | 43 | 0.095 (0.070–0.128) |
| 2009 | 48,230 | 45,817 (95.0) | 2413 (5.0) | 44 | 0.091 (0.068–0.122) |
| 2010 | 47,044 | 44,731 (95.1) | 2313 (4.9) | 51 | 0.108 (0.082–0.143) |
| 2011 | 46,751 | 44,594 (95.4) | 2157 (4.6) | 57 | 0.122 (0.094–0.158) |
| 2012 | 46,817 | 44,794 (95.7) | 2023 (4.3) | 52 | 0.111 (0.085–0.146) |
| 2013 | 45,315 | 43,401 (95.8) | 1914 (4.2) | 59 | 0.130 (0.101–0.168) |
| 2014 | 40,165 | 38,374 (95.5) | 1791 (4.5) | 59 | 0.147 (0.112–0.185) |
| 2015 | 43,028 | 41,265 (95.9) | 1763 (4.1) | 62 | 0.144 (0.112–0.185) |
| 2016 | 49,566 | 47,680 (96.2) | 1886 (3.8) | 70 | 0.141 (0.112–0.178) |
| 2017 | 51,871 | 49,925 (96.2) | 1946 (3.8) | 56 | 0.108 (0.083–0.140) |
| 2018 | 51,262 | 49,327 (96.2) | 1935 (3.8) | 53 | 0.103 (0.079–0.135) |
| 2019 | 51,948 | 50,088 (96.4) | 1860 (3.6) | 71 | 0.137 (0.108–0.172) |
| 2020† | 20,421 | 19,713 (96.5) | 708 (3.5) | 26 | 0.127 (0.083–0.187) |
*CBDI incidence is calculated as the proportion of CBDI divided by the total number of cholecystectomies (open and laparoscopic combined) for each year of the study period, with 95% CI calculated using the exact binomial method.
†Follow-up for 2020 extends only through June 30.
Determinants of Bile Duct Injuries
The associations of common indications for surgery and comorbidities with CBDI are illustrated in Table 3. In fully adjusted models, biliary colic was inversely associated with CBDI (OR = 0.82; 95% CI: 0.71–0.94), whereas odds of CBDI was increased among individuals with cholecystitis (OR = 1.14; 95% CI: 0.89–1.47), other gallbladder disease (OR = 1.90, 95% CI: 1.66–2.43), and diseases of the pancreas (OR = 2.16, 95% CI: 1.92–2.43). We observed decreased odds of CBDI among individuals diagnosed with obesity (OR = 0.70, 95% CI: 0.59–0.84) and increased odds among individuals diagnosed with atrial fibrillation (OR = 1.15, 95% CI: 0.92–1.43) and chronic liver disease (OR = 1.25, 95%C I: 1.05–1.49).
TABLE 3.
| Model 1* | Model 2†,§ | |
|---|---|---|
| OR (95% CI) | OR (95% CI) | |
| Indications for surgery | ||
| Biliary colic | 0.82 (0.71–0.94) | 0.82 (0.71–0.94) |
| Cholecystitis | 1.26 (0.98–1.62) | 1.14 (0.89–1.47) |
| Other gallbladder disease | 1.99 (1.75–2.84) | 1.90 (1.66–2.17) |
| Diseases of the pancreas | 2.53 (2.14–2.98) | 2.16 (1.92–2.43) |
| Comorbidities | ||
| Obesity | 0.70 (0.59–0.84) | 0.70 (0.59–0.84) |
| Coronary artery disease | 0.97 (0.82–1.16) | 0.97 (0.81–1.15) |
| Atrial fibrillation | 1.15 (0.93–1.42) | 1.15 (0.92–1.43) |
| Chronic kidney disease | 0.94 (0.76–1.17) | 0.92 (0.74–1.16) |
| Chronic liver disease | 1.26 (1.07–1.49) | 1.25 (1.05–1.49) |
*Bile duct injuries were identified using CPT codes 47720, 47721, 47740, 47760, 47765, 47780, 47785, 47790, and 47800.
†Generalized logistic regression was used to estimate ORs for the association between indications for surgery and bile duct injuries, and the association between comorbidities and bile duct injuries.
‡Each model includes each indication for surgery and comorbidity separately while adjusting for gender, age category, procedure type (open vs laparoscopic), and indicator variables for calendar year and US state.
§Model includes all indicators for surgery and comorbidities simultaneously, while adjusting for gender, age category, procedure type (open vs laparoscopic), and indicator variables for calendar year and region.
All-Cause Mortality and Bile Duct Injuries
In the unadjusted model, the hazard of all-cause mortality among individuals with CBDI was 3.44 times the hazard among those without CBDI (95% CI: 3.02–3.91). The magnitude of this association was attenuated after control for demographic characteristics (hazard ratio [HR] = 1.58, 95% CI: 1.39–1.81). In fully adjusted models that further included common indications for surgery and comorbidities, the hazard of all-cause mortality among individuals with CBDI was 1.57 times the hazard among those without BCDI (95% CI: 1.38–1.79) (Table 4, Supplemental Figure 3, http://links.lww.com/AOSO/A203). In subgroup analyses, the association was strongest among those ages 35–54 (HR = 2.62, 95% CI: 1.85–3.71), white patients (HR = 1.68, 95% CI: 1.43–1.97), and in the Northeast (HR = 2.43, 95% CI: 1.09–4.42). Among those who underwent laparoscopic cholecystectomy, the hazard of all-cause mortality among those with CBDI was 3.02 times the hazard of those without CBDI (95% CI: 2.48–3.68). By contrast, we observed limited evidence of an association between CBDI and all-cause mortality among those who underwent open surgery (HR = 1.09, 95% CI: 0.94–1.05) (Supplemental Table 1, http://links.lww.com/AOSO/A203).
TABLE 4.
Adjusted Hazard Ratios for All-Cause Mortality Associated With Bile Duct Injury in Patients Undergoing Cholecystectomy, 2003–2020 (N = 777,486)*,†,‡
| Model 1 | Model 2 | Model 3 | |
|---|---|---|---|
| HR (95% CI) | HR (95% CI) | HR (95% CI) | |
| Bile duct injury‡ | |||
| No | 1.00 | 1.00 | 1.00 |
| Yes | 3.44 (3.02–3.91) | 1.58 (1.39–1.81) | 1.57 (1.38–1.79) |
| Sex | |||
| Female | 1.00 | 1.00 | |
| Male | 1.45 (1.42–1.47) | 1.19 (1.17–1.21) | |
| Age, y | |||
| 18–34 | 1.00 | 1.00 | |
| 35–44 | 1.83 (1.68–1.99) | 1.82 (1.67–1.98) | |
| 45–54 | 4.31 (3.99–4.65) | 4.12 (3.82–4.45) | |
| 55–64 | 10.2 (9.47–11.0) | 8.85 (8.22–9.53) | |
| 65+ | 33.2 (30.9–35.6) | 22.3 (20.8–23.9) | |
| Race/ethnicity | |||
| White | 1.00 | 1.00 | |
| Asian | 0.79 (0.74–0.84) | 0.81 (0.76–0.86) | |
| Black | 1.17 (1.34–1.20) | 1.14 (1.11–1.18) | |
| Hispanic | 0.79 (0.77–0.82) | 0.82 (0.79–0.84) | |
| Missing | 1.13 (1.10–1.16) | 1.16 (1.12–1.19) | |
| Region | |||
| Midwest | 1.00 | 1.00 | |
| Northeast | 1.15 (1.10–1.20) | 1.16 (1.11–1.22) | |
| South | 1.05 (1.03–1.07) | 1.04 (1.02–1.06) | |
| West | 1.06 (1.03–1.08) | 1.05 (1.03–1.07) | |
| Type | |||
| Laparoscopic | 1.00 | 1.00 | |
| Open | 2.13 (2.08–2.18) | 1.98 (1.94–2.02) | |
| Indications for surgery | |||
| Biliary colic | 0.92 (0.90–0.93) | ||
| Cholecystitis | 1.08 (1.04–1.12) | ||
| Other gallbladder disease | 0.98 (0.97–1.00) | ||
| Diseases of the pancreas | 1.21 (1.18–1.23) | ||
| Comorbidities | |||
| Obesity | 0.83 (0.81–0.85) | ||
| Coronary artery disease | 1.63 (1.60–1.66) | ||
| Atrial fibrillation | 1.88 (1.85–1.92) | ||
| Chronic kidney disease | 2.10 (2.06–2.14) | ||
| Chronic liver disease | 1.08 (1.05–1.10) | ||
*Bile duct injuries were identified using CPT codes 47701, 47720, 47721, 47740, 47760, 47765, 47780, 47785, 47790, and 47800.
†All-cause mortality was defined using date of death extracted from National Death Index files.
‡Multivariable Cox proportional hazards regression analysis was used to examine the association between bile duct injury and all-cause mortality among patients who underwent cholecystectomy. The model was simultaneously adjusted for gender, age category, race/ethnicity, procedure type (laparoscopic vs open), and select indications for surgery and comorbidities identified in the 3 years preceding date of surgery.
Time-to-Repair and Costs
Among individuals with CBDI, the mean overall cost—calculated from seven days prior to cholecystectomy through 30 days after CBDI repair—was lowest among individuals with same-day repair ($63,524, 95% CI: 27,694–99,355) and highest among individuals with repair between 1 and 3 months following cholecystectomy ($176,581, 95% CI: 132,637–220,525). We additionally calculated mean postoperative costs for the 30-day period after CBDI repair. Consistent with our overall cost estimates, we observed the lowest mean postoperative cost among individuals who underwent same-day repair ($9,075, 95% CI: $1717–16,432). However, we observed the highest mean postoperative costs among individuals who underwent repair within 1 week of cholecystectomy ($21,743, 95% CI: 13,011–30,476) with decreases in mean postoperative costs thereafter (Fig. 1, Supplemental Table 2, http://links.lww.com/AOSO/A203). This overall pattern was consistent when we extended the window for calculating overall and postoperative costs to 90 days after BDI repair (Supplemental Table 3, http://links.lww.com/AOSO/A203).
FIGURE 1.
Average 30-day costs associated with BDI by time elapsed between injury and repair. A, The total average costs accrued between seven days prior to the index surgery and 30 days after BDI repair (total cost). B, The total average costs accrued in the 30-day period after the BDI repair (postoperative cost) among 1657 patients with BDI followed for at least 30 days after repair. We calculated the time elapsed in days between the index surgery in which the injury to the common bile duct occurred and the date of repair. We categorized timing of the repair as a same day repair; occurring within 1 week; >1 week but within 1 month; >1 month but within 3 months; and <3 months after the index surgery. We calculated the sum of all unique standard costs in the time-period of interest. To account for differences in pricing across health plans and provider contracts, Optum applies standard pricing algorithms claims data to produce standard prices that reflect allowed payments across all provider services. Average costs represent the marginal mean cost within each group adjusting for sex, age category, race/ethnicity, US Census region, open vs laparoscopic cholecystectomy, indications for cholecystectomy, and common comorbidities.
DISCUSSION
Although prior research has been limited by small sample sizes given the relatively infrequent nature of this complication, there are some notable exceptions. Among the first systematic examinations of CBDI is the retrospective nationwide cohort analysis of Medicare patients undergoing cholecystectomy conducted by Flum et al from 1992 to 1999. This study identified 1,570,361 cholecystectomies and 7911 CBDI (0.5% of operations), and further demonstrated a nearly 3-fold increase in the risk of death for patients with CBDI as compared to those without.13 Earlier large-scale analyses of patients undergoing cholecystectomy in Italy and Sweden demonstrated similar rates of CBDI.39,40 More recent analyses of the New York State Planning and Research Cooperate System (SPARCS) and of nationwide claims data demonstrate reduced rates of CBDI during cholecystectomy that ranged from 0.8% to 0.23%,41–44 with some evidence of increased all-cause mortality risk particularly among key population subgroups including older patients, men, and those with pre-existing conditions such as diabetes and hypertension.41,43
In this study, we leveraged nationwide claims data gathered over a 17-year study period to systematically characterize the determinants, mortality risk, and cost associated with CBDI. We identified 769,782 individuals who underwent cholecystectomy and 894 operatively managed CBDI, which yields an overall incidence of 0.1%. This estimate is notably reduced as compared with the incidence of 0.5% cited by Flum and colleagues in their analysis of Medicare beneficiaries and more comparable to the incidence reported in more recent analyses. The apparent reduction in CBDI incidence over time may reflect the inclusion of adults under the age of 65 in our analysis, but is also potentially consistent with the notion that concerted efforts to improve surgeons’ recognition of key anatomical landmarks during laparoscopic surgery have yielded the intended reduction in the occurrence of CBDI.4,45,46
The present study provides a natural complement to more recent studies of CBDI by including a detailed examination of individual-level determinants. We observed that CBDI occurred more frequently in older patients, but in contrast with prior research individuals with CBDI were more likely to be female as compared to patients who underwent cholecystectomy uncomplicated by CBDI. In multivariable adjusted analyses, other gallbladder disease (including obstruction of the gallbladder, hydrops of the gallbladder, perforation of the gallbladder, fistula of the gallbladder and perforation of the bile duct), diseases of the pancreas, and chronic liver disease were associated with increased odds of CBDI. By contrast, we observed decreased odds of CBDI associated obesity, a seemingly paradoxical finding may reflect selection of healthier patients with elevated BMI for surgery. Overall, our results suggest that individual-level characteristics may be important drivers of residual CBDI risk. Additional research that explicitly considers the mechanisms by which patient-level characteristics pattern CBDI risk in populations may yield further reductions in its incidence.
After adjusting for patient demographics and comorbid illness, all-cause mortality risk among individuals with CBDI was 1.5 times the risk among individuals without CBDI. By contrast, Flum et al. estimated a 2.79-fold increase in all-cause mortality associated with CBDI among Medicare beneficiaries from 1992 to 1999. One potential explanation for the attenuated magnitude of association is that advances in management of CBDI in tandem with more general improvements postoperative management and critical care in the intervening years have improved survival. In subgroup analysis by age, the association with all-cause mortality is stronger in younger adults (ages 18–54) as compared with individuals over the age of 65. This finding may again reflect the fact that mortality risk is generally increased among older adults making those with and without CBDI more similar, whereas among younger adults who experience CBDI, there is a significant change in their health status and therefore mortality risk.
Finally, this study includes an analysis of total cost and postoperative costs by time elapsed between CBDI and repair. Previous studies have concluded that overall delays in surgical repair decrease the risk of postoperative complications,22,47–50 whereas other studies find similar results for early versus delayed repair.27,51,52 In our analysis, the average total cost and postoperative cost (ie, costs accrued after CBDI repair) were the lowest among individuals who underwent same-day repair. This should not be surprising as these patients had a rapid diagnosis and were treated promptly. However, for many patients, this scenario will not be realistic as the subspecialist expertise required to definitively manage CBDI is not present at most hospitals where cholecystectomy is performed.53,54 The total cost associated with repair was generally increased with longer delays between cholecystectomy repair, reflecting the costs associated with prolonged hospitalization, re-admission, and the performance of biliary drainage or diversion procedures to temporize these patients.55 Delays in repair only yielded savings post-operatively, perhaps by allowing for adequate sepsis control, clarification of biliary anatomy, and restoration/repair or collateralization of vascular damage as has been previously theorized.54
LIMITATIONS
The study population was comprised 770,000 privately insured individuals who underwent cholecystectomy from 2003 to 2020, which represents approximately 6% of national procedures. Generalizability of our findings is further limited by the exclusion of individuals with Medicaid. In our analysis of all-cause mortality risk, we aimed to minimize bias due to confounding by controlling for individual-level demographics as well as comorbid conditions and indications for surgery that could plausibly increase risk for CBDI during cholecystectomy and influence survival. Previous studies have further included physician-level covariates, using number of repair procedures as a proxy for surgeon experience. We did not control for physician-level covariates in our analysis, which may represent a potential source of unmeasured confounding. However, we suspect that using the number of repair procedures as a proxy for surgical experience may ultimately introduce measurement error as it is does not reflect the surgeon’s skill level, whether they completed subspecialty training in hepatobiliary surgery, or whether the procedure was completed by a surgical trainee. Although our analysis includes fixed effects for US census region, the authors were unable to account for potential nonindependence of outcomes for patients treated in the same hospital or hospital system.
Potential sources of measurement error in this analysis include inaccuracy of diagnostic codes used to identify indications for surgery and comorbid illness. For example, cholecystitis was identified as an indicator for over 95% of cholecystectomies, which may overestimate the true prevalence of cholecystitis due to physician upcoding We do not suspect that these inaccuracies are systematically different among patients with and without CBDI or based on vital status. Cost data are subject to differences across geographic regions, health plans, and provider contracts. Therefore, we utilized standard costs derived using pricing algorithms that reflect allowed payments across all provider services in these data. Data on BDI repair success, a likely determinant of both survival and overall costs, were not available for our analysis. Finally, although we examine the healthcare costs associated with CBDI, it must be stated that this underestimates the true cost of this morbid, and potentially devastating complication as it does not reflect the additional losses in productivity, absenteeism, disability, and quality of life.
CONCLUSION
Building on prior research, the present study aims to provide a detailed and comprehensive examination of CBDI requiring operative in a contemporary patient population. Among 769,782 individuals who underwent cholecystectomy, we identified 894 (0.1%) with CBDI—a rate which is substantially lower than prior large studies and suggests an impact of quality-improvement initiatives over the past 2 decades. CBDI remains associated with increased all-cause mortality risk and significant healthcare costs, although savings may be realized with early repair when safe and feasible. Finally, our analysis suggests a potentially important role for individual-level demographic and health characteristics as determinants of CBDI risk, and additional research that explicitly considers the mechanisms by which patient-level characteristics influence CBDI risk that may yield further reductions in its incidence.
Supplementary Material
Footnotes
Published online 2 February 2023
Disclosure: The authors declare that they have nothing to disclose.
Supplemental digital content is available for this article. Direct URL citations appear in the printed text and are provided in the HTML and PDF versions of this article on the journal’s Web site (www.annalsofsurgery.com).
REFERENCES
- 1.Vollmer CM, Callery MP. Biliary injury following laparoscopic cholecystectomy: why still a problem? Gastroenterology. 2007;133:1039–1041. [DOI] [PubMed] [Google Scholar]
- 2.Wadhwa V, Jobanputra Y, Garg SK, et al. Nationwide trends of hospital admissions for acute cholecystitis in the United States. Gastroenterology report. 2017;5:36–42. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 3.Flum DR, Koepsell T, Heagerty P, et al. Common bile duct injury during laparoscopic cholecystectomy and the use of intraoperative cholangiography: adverse outcome or preventable error? Arch Surg. 2001;136:1287–1292. [DOI] [PubMed] [Google Scholar]
- 4.Kohn JF, Trenk A, Kuchta K, et al. Characterization of common bile duct injury after laparoscopic cholecystectomy in a high-volume hospital system. Surg Endosc. 2018;32:1184–1191. [DOI] [PubMed] [Google Scholar]
- 5.Soper NJ, Stockmann PT, Dunnegan DL, et al. Laparoscopic cholecystectomy the new’gold standard’? Arch Surg. 1992;127:917–923. [DOI] [PubMed] [Google Scholar]
- 6.Bernard HR, Hartman TW. Complications after laparoscopic cholecystectomy. Am J Surg. 1993;165:533–535. [DOI] [PubMed] [Google Scholar]
- 7.Caputo L, Aitken D, Mackett M, et al. Iatrogenic bile duct injuries. The real incidence and contributing factors—implications for laparoscopic cholecystectomy. Am Surg. 1992;58:766–771. [PubMed] [Google Scholar]
- 8.Fletcher DR, Hobbs MS, Tan P, et al. Complications of cholecystectomy: risks of the laparoscopic approach and protective effects of operative cholangiography: a population-based study. Ann Surg. 1999;229:449–457. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 9.Törnqvist B, Strömberg C, Persson G, et al. Effect of intended intraoperative cholangiography and early detection of bile duct injury on survival after cholecystectomy: population based cohort study. BMJ. 2012;345:e6457–e6457. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 10.Morgenstern L, McGrath MF, Carroll BJ, et al. Continuing hazards of the learning curve in laparoscopic cholecystectomy. Am Surg. 1995;61:914–918. [PubMed] [Google Scholar]
- 11.Halbert C, Pagkratis S, Yang J, et al. Beyond the learning curve: incidence of bile duct injuries following laparoscopic cholecystectomy normalize to open in the modern era. Surg Endosc. 2016;30:2239–2243. [DOI] [PubMed] [Google Scholar]
- 12.Archer SB, Brown DW, Smith CD, et al. Bile duct injury during laparoscopic cholecystectomy: results of a national survey. Ann Surg. 2001;234:549–559. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 13.Flum DR, Cheadle A, Prela C, et al. Bile duct injury during cholecystectomy and survival in medicare beneficiaries. JAMA. 2003;290:2168–2173. [DOI] [PubMed] [Google Scholar]
- 14.Strasberg SM, Brunt LM. Rationale and use of the critical view of safety in laparoscopic cholecystectomy. J Am Coll Surg. 2010;211:132–138. [DOI] [PubMed] [Google Scholar]
- 15.Vettoretto N, Saronni C, Harbi A, et al. Critical view of safety during laparoscopic cholecystectomy. JSLS. 2011;15:322. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 16.Murr MM, Gigot J-F, Nagorney DM, et al. Long-term results of biliary reconstruction after laparoscopic bile duct injuries. Arch Surg. 1999;134:604–610. [DOI] [PubMed] [Google Scholar]
- 17.Sicklick JK, Camp MS, Lillemoe KD, et al. Surgical management of bile duct injuries sustained during laparoscopic cholecystectomy: perioperative results in 200 patients. Ann Surg. 2005;241:786–795. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 18.Nuzzo G, Giuliante F, Giovannini I, et al. Advantages of multidisciplinary management of bile duct injuries occurring during cholecystectomy. Am J Surg. 2008;195:763–769. [DOI] [PubMed] [Google Scholar]
- 19.Savader SJ, Lillemoe KD, Prescott CA, et al. Laparoscopic cholecystectomy-related bile duct injuries: a health and financial disaster. Ann Surg. 1997;225:268–273. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 20.Moossa A, Mayer AD, Stabile B. Iatrogenic injury to the bile duct: who, how, where? Arch Surg. 1990;125:1028–1031. [DOI] [PubMed] [Google Scholar]
- 21.Walsh RM, Henderson JM, Vogt DP, et al. Long-term outcome of biliary reconstruction for bile duct injuries from laparoscopic cholecystectomies. Surgery. 2007;142:450–457. [DOI] [PubMed] [Google Scholar]
- 22.Ismael HN, Cox S, Cooper A, et al. The morbidity and mortality of hepaticojejunostomies for complex bile duct injuries: a multi-institutional analysis of risk factors and outcomes using NSQIP. HPB. 2017;19:352–358. [DOI] [PubMed] [Google Scholar]
- 23.de Reuver PR, Rauws EA, Bruno MJ, et al. Survival in bile duct injury patients after laparoscopic cholecystectomy: a multidisciplinary approach of gastroenterologists, radiologists, and surgeons. Surgery. 2007;142:1–9. [DOI] [PubMed] [Google Scholar]
- 24.Moore DE, Feurer ID, Holzman MD, et al. Long-term detrimental effect of bile duct injury on health-related quality of life. Arch Surg. 2004;139:476–482. [DOI] [PubMed] [Google Scholar]
- 25.Gouma D, Rauws E, Keulemans Y, et al. Bile duct injuries after a laparoscopic cholecystectomy. Ned Tijdschr Geneeskd. 1999;143:606–611. [PubMed] [Google Scholar]
- 26.Landman MP, Feurer ID, Moore DE, et al. The long-term effect of bile duct injuries on health-related quality of life: a meta-analysis. Hpb. 2013;15:252–259. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 27.Booij KA, de Reuver PR, van Dieren S, et al. Long-term impact of bile duct injury on morbidity, mortality, quality of life, and work related limitations. Ann Surg. 2018;268:143–150. [DOI] [PubMed] [Google Scholar]
- 28.Roy PG, Soonawalla ZF, Grant HW. Medicolegal costs of bile duct injuries incurred during laparoscopic cholecystectomy. HPB. 2009;11:130–134. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 29.Francoeur JR, Wiseman K, Buczkowski AK, et al. Surgeons’ anonymous response after bile duct injury during cholecystectomy. Am J Surg. 2003;185:468–475. [DOI] [PubMed] [Google Scholar]
- 30.Kern KA. Medicolegal analysis of bile duct injury during open cholecystectomy and abdominal surgery. Am J Surg. 1994;168:217–222. [DOI] [PubMed] [Google Scholar]
- 31.Carroll B, Birth M, Phillips E. Common bile duct injuries during laparoscopic cholecystectomy that result in litigation. Surg Endosc. 1998;12:310–314. [DOI] [PubMed] [Google Scholar]
- 32.van de Graaf FW, Zaïmi I, Stassen LP, et al. Safe laparoscopic cholecystectomy: a systematic review of bile duct injury prevention. Int J Surg. 2018;60:164–172. [DOI] [PubMed] [Google Scholar]
- 33.Gunaseelan V, Kenney B, Lee JS-J, et al. Databases for surgical health services research: Clinformatics Data Mart. Surgery. 2019;165:669–671. [DOI] [PubMed] [Google Scholar]
- 34.Schisterman EF, Whitcomb BW. Use of the Social Security Administration Death Master File for ascertainment of mortality status. PHM. 2004;2:1–6. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 35.Medicare Cf, Services M. CMS manual system: pub 100–03 Medicare national coverage determinations. transmittal 120. Publication Date: May 6, 2010. Change Request 6632. Subject: FDG PET for Solid Tumors and Myeloma. 2020. [Google Scholar]
- 36.Optum Insight. Clinformatics ® Data Mart User Manual. Accessed July 1, 2021, 2019. https://www.optum.com/content/dam/optum/resources/productSheets/Clinformatics_for_Data_Mart.pdf.
- 37.Searle SR, Speed FM, Milliken GA. Population marginal means in the linear model: an alternative to least squares means. Am Stat. 1980;34:216–221. [Google Scholar]
- 38.Lenth R, Buerkner P, Herve M, Love J, Riebl H, Singmann H. Package “emmeans”. Available at: https://cran.r-project.org/web/packages/emmeans/emmeans.pdf. 2021. Accessed July 1, 2021.
- 39.Nuzzo G, Giuliante F, Giovannini I, et al. Bile duct injury during laparoscopic cholecystectomy: results of an Italian national survey on 56 591 cholecystectomies. Arch Surg. 2005;140:986–992. [DOI] [PubMed] [Google Scholar]
- 40.Waage A, Nilsson M. Iatrogenic bile duct injury: a population-based study of 152 776 cholecystectomies in the Swedish Inpatient Registry. Arch Surg. 2006;141:1207–1213. [DOI] [PubMed] [Google Scholar]
- 41.Halbert C, Altieri MS, Yang J, et al. Long-term outcomes of patients with common bile duct injury following laparoscopic cholecystectomy. Surg Endosc. 2016;30:4294–4299. [DOI] [PubMed] [Google Scholar]
- 42.Altieri MS, Yang J, Obeid N, et al. Increasing bile duct injury and decreasing utilization of intraoperative cholangiogram and common bile duct exploration over 14 years: an analysis of outcomes in New York State. Surg Endosc. 2018;32:667–674. [DOI] [PubMed] [Google Scholar]
- 43.Barrett M, Asbun HJ, Chien H-L, et al. Bile duct injury and morbidity following cholecystectomy: a need for improvement. Surg Endosc. 2018;32:1683–1688. [DOI] [PubMed] [Google Scholar]
- 44.Fong ZV, Pitt HA, Strasberg SM, et al. Diminished survival in patients with bile leak and ductal injury: management strategy and outcomes. J Am Coll Surg. 2018;226:568–576e1. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 45.Strasberg SM, Hertl M, Soper N J. An analysis of the problem of biliary injury during laparoscopic cholecystectomy. J Am Coll Surg. 1995;180:101–125. [PubMed] [Google Scholar]
- 46.Strasberg SM. A three-step conceptual roadmap for avoiding bile duct injury in laparoscopic cholecystectomy: an invited perspective review. J Hepatobiliary Pancreat Sci. 2019;26:123–127. [DOI] [PubMed] [Google Scholar]
- 47.Kapoor VK. Bile duct injury repair: when? what? who?. J Hepatobiliary Pancreat Surg. 2007;14:476–479. [DOI] [PubMed] [Google Scholar]
- 48.de Reuver PR, Grossmann I, Busch OR, et al. Referral pattern and timing of repair are risk factors for complications after reconstructive surgery for bile duct injury. Ann Surg. 2007;245:763–770. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 49.Iannelli A, Paineau J, Hamy A, et al. Primary versus delayed repair for bile duct injuries sustained during cholecystectomy: results of a survey of the Association Francaise de Chirurgie. HPB. 2013;15:611–616. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 50.Dominguez-Rosado I, Sanford DE, Liu J, et al. Timing of surgical repair after bile duct injury impacts postoperative complications but not anastomotic patency. Ann Surg. 2016;264:544–553. [DOI] [PubMed] [Google Scholar]
- 51.Kirks RC, Barnes T, Lorimer PD, et al. Comparing early and delayed repair of common bile duct injury to identify clinical drivers of outcome and morbidity. HPB. 2016;18:718–725. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 52.Felekouras E, Petrou A, Neofytou K, et al. Early or delayed intervention for bile duct injuries following laparoscopic cholecystectomy? A dilemma looking for an answer. Gastroenterol Res Pract. 2015;2015:1–10. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 53.Stewart L, Way LW. Laparoscopic bile duct injuries: timing of surgical repair does not influence success rate. A multivariate analysis of factors influencing surgical outcomes. Hpb. 2009;11:516–522. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 54.Schreuder AM, Busch OR, Besselink MG, et al. Long-term impact of iatrogenic bile duct injury. Dig Surg. 2020;37:10–21. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 55.Dageforde LA, Landman MP, Feurer ID, et al. A cost-effectiveness analysis of early vs late reconstruction of iatrogenic bile duct injuries. J Am Coll Surg. 2012;214:919–927. [DOI] [PubMed] [Google Scholar]
Associated Data
This section collects any data citations, data availability statements, or supplementary materials included in this article.