Figure 1. Distribution of disease process by surgical method used in 2009 (percentage). NIS indicates Nationwide Inpatient Sample.
Figure 2. Use of laparoscopy according to disease type in 2007 and 2009.
Figure 3. The use of laparoscopy according to procedure type in 2007 and 2009. APR indicates abdominoperineal resection.
Figure 4. Surgical methods used in colorectal surgery in 2007 and 2009 (percentage).
Kang CY, Halabi WJ, Luo R, Pigazzi A, Nguyen NT, Stamos MJ. Laparoscopic Colorectal SurgeryA Better Look Into the Latest Trends. Arch Surg. 2012;147(8):724-731. doi:10.1001/archsurg.2012.358
Author Affiliations: From the Department of Surgery, University of California, Irvine School of Medicine, Irvine.
Background The latest trends of laparoscopic colorectal surgery (LCRS) after the introduction of International Classification of Diseases, Ninth Revision laparoscopic procedure codes in 2008 remains unknown. This study evaluates LCRS trends before and after the application of specific codes for LCRS.
Design Retrospective analysis of elective surgery for colon cancer, rectal cancer, and diverticulitis using Nationwide Inpatient Sample data from 2007 and 2009.
Main Outcome Measure Primary outcome measures included in-hospital mortality, length of stay, and total charge.
Results A total of 126 921 patients in 2007 and 117 177 patients in 2009 underwent colorectal surgery. Laparoscopic colorectal surgery increased dramatically from 13.8% in 2007 to 42.6% in 2009 (P < .01). This trend was disease and procedure specific. When compared with 2007, patients who underwent LCRS in 2009 had lower conversion rates (14.8% vs 32.1%, P < .001). In 2009, LCRS had lower in-hospital mortality (0.5% vs 1.1%, P < .001) and a shorter length of hospital stay (5 vs 6 days, P < .001) compared with open surgery. In 2009, when compared with successful LCRS, conversion to open surgery was associated with a longer length of hospital stay (6 vs 5 days, P < .01), increased hospital charges, and increased mortality (0.7% vs 0.5%, P < .01).
Conclusion The marked increase in LCRS when comparing these 2 years is unlikely only due to the changing practice of colorectal surgery but brings into question the accuracy of data prior to 2009. Our report of Nationwide Inpatient Sample 2009 data represents the most accurate reflection of the use of LCRS in the United States. These data can serve as a benchmark for future comparative studies.
Laparoscopic colorectal surgery (LCRS) dates back to 19911,2; however, this technique was not readily accepted by the surgical community because of concerns regarding safety and efficacy. Around the same time, laparoscopic cholecystectomy, introduced in 1987,3 rapidly became the standard of care for symptomatic gallstone disease.4,5 Several factors led to the slow adoption of laparoscopy in colorectal surgery: the technical difficulty of the procedure,6 the lack of standardized technique,7 but most important, the adequacy of oncologic resection, including lymphadenectomy,8,9 and concerns about early local and port site recurrences.10- 12 Longer operative times13- 15 and increased cost15- 18 also hindered the use of laparoscopy.
Retrospective medical record reviews and small prospective series looked at short-term outcomes of LCRS, particularly in treating cancer. Later, large randomized controlled trials in the 1990s showed that laparoscopy was associated with an earlier return of bowel function,14,19- 23 shorter length of hospital stay,14,20,23- 27 decreased morbidity,14,26,28,29 and less postoperative pain.21,23- 25,27,30 Tumor margins were clear, and there was no difference in local recurrence rates compared with open surgery.21,26,27,31- 33 Laparoscopy had short-term survival rates similar to open surgery.24,34,35 Furthermore, the long-term results of those randomized trials revealed similar disease-free rates, recurrence rates, and overall survival.19,36,37 Large population-based studies in the early 2000s demonstrated favorable outcomes of laparoscopy, further supporting the use of laparoscopy in colorectal surgery.38- 45
Data from the Nationwide Inpatient Sample (NIS) and other large databases have provided nationwide estimates of the overall use of laparoscopy in colorectal surgery. These data rely heavily on the International Classification of Diseases, Ninth Revision (ICD-9) procedure codes. Before 2008, no specific codes for laparoscopic colorectal procedures existed, and previous data were extrapolated using open procedure codes linked with a laparoscopic modifier to identify laparoscopic cases. This may have affected the accuracy of previous data; however, this assumption has not been proved. The objective of the current study is to examine the latest trends in LCRS from 2007 and 2009, before and after the introduction of laparoscopic-specific codes, to provide accurate and up-to-date information on the use of laparoscopy in colorectal surgery.
Using the Healthcare Cost and Utilization Project's NIS database, a retrospective comparison of elective laparoscopic and open colorectal resections was performed for 2007 and 2009. The NIS is the largest all-payer inpatient care database in the United States, containing information from almost 8 million hospital stays each year. The data set approximates a 20% stratified sample of US community hospitals, resulting in a sampling frame of approximately 90% of all hospital discharges in the United States. Data elements are drawn from hospital discharge abstracts. Approval for the use of the NIS patient-level data was obtained from the Institutional Review Board of the University of California, Irvine School of Medicine and the NIS.
Patients who underwent elective surgery for colon cancer, rectal cancer, and diverticulitis were included in our study. Using ICD-9 codes, hospitalizations associated with a colorectal resection were identified. Procedures used are based on procedures reviewed in previous randomized controlled trials and meta-analyses. The ICD-9 codes used are listed in Table 1.
Patients admitted emergently were excluded to prevent bias favoring open procedures. Inflammatory bowel disease (Crohn and ulcerative colitis) and benign neoplasm were also excluded. Specific ICD-9 codes for laparoscopic surgery were published during 2008; therefore, data from 2008 were excluded.
Because no distinct ICD-9 procedure codes existed for laparoscopic colon resection in 2007, we identified procedures that were performed laparoscopically by using an open code with additional ICD-9 modifier codes for laparoscopy (54.21) or laparoscopic lysis of adhesions (54.51). The ICD-9 code V64.4 was used to identify laparoscopic surgery converted to open surgery. These were included in the LCRS group on an intent-to-treat basis.
In 2009, the specific International Classification of Diseases, Ninth Revision, Clinical Modification(ICD-9-CM) codes for laparoscopic colorectal procedures were used. Procedure codes with the ICD-9-CM code of V64.4 indicated laparoscopic surgery converted to open procedures. Converted cases were included in the LCRS group on an intent-to-treat basis. A specific code for laparoscopic anterior resection (AR) is not available, so the code for open AR with a laparoscopic modifier code was used to identify laparoscopic ARs as performed in 2007.
The overall use of laparoscopy in 2007 and 2009, the rate of laparoscopy according to disease type, hospital type (teaching vs nonteaching), procedure type, and conversion rate from laparoscopic surgery to open surgery were examined. Data such as age, sex, race/ethnicity, primary payer type, length of hospital stay, hospital charge, and in-hospital mortality were examined.
Race/ethnicity classification was missing from 28.8% of our patients. Total hospital charge was missing from 2.4% of our patients. Data on age, sex, payer type, teaching hospital status, and in-house mortality were missing in <0.3% of patients included in the present study.
All statistical analyses were conducted using SPSS, version 17.0 (SPSS Inc). The number of LCRSs performed was quantified. Age was described by mean (SD), and the t test was used to compare the difference between 2 groups. The χ2 test was used to compare laparoscopic surgery with open surgery for sex, race/ethnicity, primary payer type, in-house mortality, disease process, procedure type, hospital type, and conversion rate. The length of hospital stay and total hospital charge were described by median and full range. The Mann-Whitney test was used to compare the difference between the 2 groups. Statistical significance was set at a P < .05.
In 2007, a total of 126 921 patients underwent colorectal resection; of these, only 13.8% were performed laparoscopically. Outcomes are outlined in Table 2 and Table 3. Laparoscopic colorectal surgery was more frequently performed in slightly younger patients (mean age, 62.6 vs 64.4 years for laparoscopic vs open procedures, respectively; P < .001) who were white (P < .001). Females accounted for 50.9% of the total patients. Patients with private insurance and health maintenance organization (HMO) coverage most commonly (50.7%) underwent LCRS, followed by Medicare patients (43.5%). This was the opposite for open surgery, in which the most common payer type was Medicare (49.2%) followed by private insurance and HMO (43.2%) coverage. About half the patients (49.6%) received care from a teaching hospital, in which LCRS was more likely to be performed (Table 3). In teaching hospitals, laparoscopy was used in only 14.5% of all colorectal procedures; however, this was still higher than the 13.3% for nonteaching hospitals.
The conversion rate from laparoscopic surgery to open surgery constituted 32.1% of all LCRS cases. The conversion rate was highest for rectal cancer cases and was similar among teaching and nonteaching hospitals (Table 4). The median length of hospital stay was shorter for patients undergoing LCRS compared with those undergoing open surgery (5 vs 6 days, respectively; P < .001). Laparoscopy was also associated with lower mortality rates than open surgery (0.6% vs 1.2%, respectively; P < .001). Diverticulitis was the most common indication for laparoscopy, accounting for 51.4% of the LCRS cases performed in 2007. However, only 18.0% of the surgical procedures done for diverticulitis were performed laparoscopically. Open surgery was more commonly performed for malignant tumors, with the lowest utilization of laparoscopy for rectal cancer patients (7.6%). Sigmoidectomy was the most commonly performed laparoscopic procedure, accounting for 42.2% of LCRS, followed by right hemicolectomy at 24.5%.
In 2009, a total of 117 177 patients underwent colorectal resection. Outcomes are outlined in Tables 2 and 3. In 2009, laparoscopy was performed in a slightly younger population. The average age of patients undergoing laparoscopy was 62.4 years compared with those aged 64.8 years in the open surgery group. Laparoscopy was performed slightly more in whites, but the disparity among ethnicities was not statistically significant. Distribution of disease processes by surgical method, including laparoscopy, is shown in Figure 1. Similar to 2007, patients undergoing LCRS were more likely to have private insurance coverage, including HMO coverage (50.8%), as their primary payer type, followed by Medicare (42.7%). This trend, again, was reversed in the open surgery group, in which Medicare (49.9%) was found to be the most common primary payer type, followed by HMO coverage (41.4%).
In 2009, almost half (49.6%) of cases performed for diverticulitis were done laparoscopically. This translates into laparoscopic sigmoidectomy surpassing open surgery for sigmoid resections in 2009, with 54.5% of sigmoid resections performed laparoscopically in this year. Laparoscopic sigmoidectomy was the most common colorectal operation performed in 2009.
The 2009 data also confirmed that laparoscopic surgery is associated with a shorter hospital stay compared with open surgery (5 days vs 6 days, respectively; P < .001) and a significantly lower in-house mortality rate when compared to open surgery (0.5% vs 1.1%, respectively; P < .001). Hospital charges were also significantly lower in patients undergoing laparoscopic vs open surgery ($38 715.4 vs $40 412.2, respectively; P < .001; Table 2). Conversion rates were much lower in 2009 than in 2007 (Table 4). There were 14.8% of laparoscopic cases converted to open surgery in 2009 compared with 32.1% in 2007 (P < .001). In-house mortality rates increased for patients who were converted to open surgery from 2007 to 2009 (0.5% vs 0.7%, P < .01). Converted cases were also associated with the highest hospital charge despite the same duration of hospital stay as open surgery. Conversion rates were similar between teaching and nonteaching hospitals. In 2009, among the different pathologic features, the conversion rate was highest in rectal cancer at 28.8%. Among procedures, the conversion rate was highest in the more technically challenging operations, such as transverse colectomy and total colectomy. Laparoscopic right hemicolectomy had the lowest conversion rate at 10.6%, followed by laparoscopic sigmoidectomy (12.5%). The conversion rate was surprisingly low for laparoscopic abdominoperineal resection (ARP) at 12.1%.
The most prominent finding from NIS 2009 data revealed was an apparent dramatic increase in the use of laparoscopy. Laparoscopic colorectal surgery accounted for 42.6% of all colorectal resections performed that year (up from 13.8% in 2007). This increase was seen with teaching hospitals performing almost half (45.9%) their colorectal caseload laparoscopically. Nonteaching hospitals also showed a similar increase, with 39.9% of colorectal cases performed laparoscopically (up from 13.3% in 2007).
The use of LCRS has had a slow upward trend in the early years, mainly because of concerns in the adequacy of oncologic resections and fear of port site recurrences.8- 12 These concerns, along with the technical complexity of the procedures,6 has led to a slow adoption of LCRS. The trend, however, has started to change. Data from 2007 show that 13.8% of colorectal resections were performed laparoscopically. This is higher than previously published NIS data in which only 3% of colon resections were performed laparoscopically in 2000 and 6.5% by 2004.46 The NIS 2007 data show that 11.7% of surgical procedures performed for colorectal cancer were done laparoscopically, which is a significant increase from the 1.4% of laparoscopic surgical procedures for colorectal cancer in 2000 and 4.3% in 2004.46 When looking at procedures types, the use of laparoscopic sigmoidectomy was only 3.8% from the period of 1998 to 2000.41 In 2007, the use of laparoscopic sigmoidectomy increased markedly to 17.5%. Furthermore, this increase is seen across disease processes and procedure types (Figure 2 and Figure 3). Other databases, such as Premier Inc,40 National Cancer Database,39 and National Surgical Quality Improvement Program (NSQIP),44 show this upward trend.
Certainly, randomized controlled trials showing both short- and long-term benefits of LCRS for malignant and benign conditions have contributed to this upward trend in the adoption of laparoscopy. Looking at the use of LCRS before and after the publication of the Clinical Outcomes of Surgical Therapy (COST) trial, the prevalence of laparoscopy after COST for malignant diseases had increased 4.55-fold compared with before COST. This was also seen for benign diseases but to a lesser extent.47 The increasing adoption of LCRS may also occur because of the increase in number of laparoscopic colorectal surgery fellowships along with increased public awareness and demand for laparoscopy.
An overall decrease in the total number of elective colorectal cancer resections was seen in 2009 (Table 5). This can be explained by the total decrease in hospital admissions for colon and rectal cancer for this year (Table 6). According to the National Cancer Institute Surveillance Epidemiology and End Results data, the overall incidence of colorectal cancer has been decreasing from 2000 to 2008.48 Also, total hospital admissions for diverticulitis had increased by 14% during our study period; however, the number of elective sigmoidectomies increased by only 2.4%. These data suggest that most patients with diverticulitis are treated nonoperatively and fewer are being treated by elective sigmoid resection. This may reflect the current trends in the treatment of diverticulitis. Chapman et al49 indicate that multiple episodes of diverticulitis are not associated with poorer outcome, and elective resection may be unwarranted.49- 51
Another interesting finding is the difference in application of LCRS in teaching and nonteaching hospitals. Despite the increased adoption of LCRS in both hospital types, LCRS is still used more often in teaching hospitals. A different trend was observed during the adoption of laparoscopic cholecystectomy. Kemp et al52 found that surgeons in small rural hospitals (nonteaching hospitals according to the NIS) adopted laparoscopic cholecystectomy at similar rates as their colleagues in urban hospitals. This suggested that rural surgeons were successful in overcoming professional isolation in learning a new procedure.52 The difference in the adoption of LCRS may be explained by the technical complexity of LCRS procedures compared with laparoscopic cholecystectomy and may also be attributed to laparoscopic fellowships offered at teaching hospitals that would translate into a greater number of trained assistants.
Despite the increased adoption of LCRS, disparities still exist. Patients who undergo LCRS are slightly younger and have private insurance, whereas Medicare patients more commonly undergo open surgery. Recent data suggest that laparoscopy is not only safe in the elderly, but it is also associated with improved outcomes.53 Medicare patients are older, and perhaps more effort should be made to use laparoscopy in this population because the overall US population is aging.
By 2007, we saw that even though the prevalence of LCRS had increased, it still remained low. Until 2008, all data, including our own, were categorized by using an open procedure code with a laparoscopic modifier, which may have underestimated the true use of LCRS. With the introduction of new ICD-9-CM codes specific for laparoscopic procedures in 2008,54 the 2009 data show that LCRS has increased tremendously. Figure 4 shows the surgical methods used in 2007 and 2009. Table 7 shows the breakdown of methods used by disease type. These marked increases cannot be attributed solely to the increased adoption of laparoscopy.
The disparity in the number of LCRSs between the 2 years can best be explained by improved precision in coding. This explanation is bolstered by looking at the raw numbers of laparoscopic AR for the 2 years. Unlike other resection types, including APR, a specific code for laparoscopic AR is unavailable. In 2009, laparoscopic AR was identified using the old method of identification used in 2007. The percentage of laparoscopic AR is minimally changed when comparing the 2 years using the old identification method (Table 8), while using the specific code for laparoscopic APR, the number of laparoscopic APRs increased 7-fold in 2009 compared with 2007 for rectal cancer. All other procedures with a specific laparoscopic code yielded a 2- to 8-fold increase in the number of laparoscopic cases in 2009. This indicates that previous data using an open-procedure ICD-9 code with a laparoscopic modifier underestimated the true incidence of use of laparoscopy in colorectal surgery. Now, with the advent of new ICD-9-CM laparoscopic procedure codes, a more accurate reflection of the use of laparoscopy can be seen. Unlike other databases, such as NSQIP, that represent data from large teaching hospitals, NIS 2009 offers the most accurate reflection of the prevalence of laparoscopic colorectal surgery in the United States, where the practice is mostly rural.
Study limitations include the use of a large database for the collection of data. The NIS does not provide information on surgeons' laparoscopic experience or fellowship training. The NIS does not provide data on long-term follow-up, as it represents data from only 1 hospital admission. Readmissions due to complications from the initial procedure are unknown. This can underestimate the morbidity and mortality rate, which is conventionally reported 30 days after a procedure. This limitation, however, is likely to affect both groups. Also, our data were obtained for elective admissions only, which likely favors the use of laparoscopy. Inflammatory bowel disease was excluded from our data, which might lead to an underestimate of the true incidence of total colectomies for ulcerative colitis and segmental resections for Crohn disease (most commonly ileocolic). The most important limitation in our study is the (intentional) use of data from years when different procedural codes where used. In 2007, open procedure ICD-9 codes linked with laparoscopic modifiers identified LCRS. This same method was used in prior studies utilizing nationwide data from the NIS,46 NSQIP,44 and the National Cancer Database.39 Coding errors can occur, as reported in previous studies using nationwide samples; however, they are likely to occur in both the open and laparoscopic group. Our 2009 data, despite these limitations, have less coding errors.
In conclusion, the use of laparoscopy is gaining widespread acceptance and is used more frequently to manage both benign and malignant colorectal conditions. However, the marked increase during a 2-year period we found is unlikely entirely due to changing trends in the practice of colorectal surgery, but brings into question the accuracy of previously reported data using the prior procedure codes. Data prior to 2009, including previous data from the NIS, are likely not an accurate representation of laparoscopic colorectal surgery. This present study using the NIS 2009 data is the most accurate reflection of the utilization of laparoscopic colorectal surgery in the United States. These data will hopefully serve as a benchmark for future comparative studies.
Correspondence: Michael J. Stamos, MD, FASCRS, Department of Surgery, 333 City Blvd, W Ste 700, Orange, CA 92868 (firstname.lastname@example.org).
Accepted for Publication: February 1, 2012.
Published Online: April 16, 2012. doi:10.1001 /archsurg.2012.358
Author Contributions:Study concept and design: Kang, Halabi, and Stamos. Acquisition of data: Luo. Analysis and interpretation of data: Kang, Halabi, Pigazzi, Nguyen, and Stamos. Drafting of the manuscript: Kang, Halabi, Luo, and Pigazzi. Critical revision of the manuscript for important intellectual content: Kang, Halabi, Nguyen, and Stamos. Statistical analysis: Kang, Halabi, and Luo. Administrative, technical, and material support: Stamos. Study supervision: Pigazzi, Nguyen, and Stamos.
Financial Disclosure: None reported.
Conflict of Interest: There is no conflict of interest or financial disclosures to be made for all authors involved in this study.