Surg Endosc DOI 10.1007/s00464-014-3798-x
and Other Interventional Techniques
The utilization of laparoscopy in ventral hernia repair: an update of outcomes analysis using ACS-NSQIP data Chetan V. Aher • John C. Kubasiak • Shaun C. Daly • Imke Janssen • Daniel J. Deziel • Keith W. Millikan • Jonathan A. Myers • Minh B. Luu
Received: 5 April 2014 / Accepted: 3 August 2014 Ó Springer Science+Business Media New York 2014
Abstract Background Numerous prospective studies and randomized controlled trials have demonstrated shorter length of stay, lower morbidity rates, and similar recurrence rates with laparoscopic ventral hernia repair (VHR) when compared to open VHR. Despite these promising results, previous data showed low utilization of laparoscopic VHR. The aim of our study was to evaluate the utilization of laparoscopic VHR using the most updated information from the American College of Surgeons—National Surgical Quality Improvement Project (NSQIP) dataset. The secondary aim was to evaluate the outcomes from NSQIP for patients undergoing open versus laparoscopic VHR for the outcome of 30-day mortality and the peri-operative morbidities listed in the NSQIP dataset. Methods We performed this study using 2009–2012 data from the ACS-NSQIP database. The study population included patients who had undergone an open or laparoscopic ventral hernia repair as their primary procedure based on CPT codes. Demographic characteristics, overall Presented at the SAGES 2014 Annual Meeting, April 2–5, 2014, Salt Lake City, Utah C. V. Aher (&) J. C. Kubasiak S. C. Daly D. J. Deziel K. W. Millikan J. A. Myers M. B. Luu Department of General Surgery, Professional Building, Suite 810, Rush University Medical Center, 1725 West Harrison Street, Chicago, IL 60612, USA e-mail: [email protected] M. B. Luu e-mail: [email protected] I. Janssen Department of Preventative Medicine, Triangle Office Building, Suite 470, Rush Graduate College, 1700 W. Van Buren Street, Chicago, IL 60612, USA
morbidity, and complications were compared using Chi-square tests for categorical variables and two-sided t tests for continuous variables. Secondary outcomes (mortality and any complications) were further analyzed using logistic regression. Results Utilization of laparoscopic VHR was 22 %. While adjusted mortality was similar, overall morbidity was increased in the open VHR group (OR 1.63; CI 95 % 1.38–1.92). The open group had a higher rate of return to the OR, pneumonia, re-intubation, ventilator requirement, renal failure/insufficiency, transfusion, DVT, sepsis, and superficial and deep incisional wound infections. Conclusions The utilization of laparoscopic VHR remained low from 2009 to 2012 and continued to lag behind the use of laparoscopy in other complex surgical procedures. The mortality rate between laparoscopic and open VHR was similar, but laparoscopic repair was associated with lower overall complication rates. Keywords Ventral hernia repair Laparoscopic surgery NSQIP Mesh hernia repair More than 100,000 ventral hernia repairs (VHR) are performed in the United States each year, resulting in significant economic effects in the form of healthcare cost and lost productivity. Laparoscopic VHR was first described by LeBlanc et al. in 1993 with the goal of shortening recovery time and improving outcomes [1]. Early case series reported shorter length of stay (LOS) than open techniques, low conversion rates, and low recurrence rates [2, 3]. More recently, numerous prospective studies and randomized controlled trials have demonstrated shorter LOS, lower morbidity rates, and similar recurrence rates with laparoscopic VHR when compared to open VHR [4–11]. Pooled
123
Surg Endosc
case series data demonstrated fewer wound infections and lower recurrence in laparoscopic VHR [12], and in 2008, a review by Misiakos et al. reported advantages of laparoscopic VHR including less post-operative pain, shorter recovery period, and better cosmetic results [13]. Two 2009 metaanalyses of the available randomized controlled trials showed that laparoscopic VHR decreased LOS and wound infection rate [14, 15]. Despite these promising results, a Cochrane review showed no difference in complication or recurrence rates between the two techniques [16]. Nationwide data from the American College of Surgeons—National Surgical Quality Improvement Project (ACS-NSQIP) database from 2005 to 2006 were first published by Hwang et al. [17], and then subsequently Mason et al. reported 2005–2009 data. With a larger dataset than any previous study, Mason et al. noted a significant decrease in overall morbidity with laparoscopic VHR. Also noted was a significant decrease in surgical site infections (superficial, deep, and organ/space), pulmonary embolism, and the development of sepsis in both their aggregate dataset and matched cohort. The data showed a 17 % utilization rate of laparoscopic VHR [18]. The aim of our study was to evaluate the utilization of laparoscopic VHR using the most updated information from the NSQIP dataset. The secondary aim was to evaluate the outcomes from NSQIP for patients undergoing open versus laparoscopic VHR for the outcome of 30-day mortality and the peri-operative morbidities were listed in the NSQIP dataset.
CPT codes including 49652, 49653, 49654, 49655, 49656, and 49657. The laparoscopic VHR group consisted of patients with CPT codes including 49560, 49561, 49565, 49570, 49572, 49585, 49587, and 49590. Outcomes The primary outcome was laparoscopic VHR utilization. Secondary outcomes included 30-day mortality and morbidity, which was defined as one of the following ACSNSQIP complications: respiratory (pneumonia, unplanned intubation, pulmonary embolism, or ventilator for [48 h), urinary tract (acute renal failure and progressive renal insufficiency), central nervous system (cerebral vascular accident, coma[24 h, and peripheral nerve injury), cardiac (cardiac arrest requiring CPR and myocardial infarction) and others (transfusion intraoperative/or with in 72 h, vein thrombosis, sepsis, and septic shock). Statistical analyses Demographic characteristics, overall morbidity, and complications were compared using Chi-square tests for categorical variables and two-sided t-tests for continuous variables. Secondary outcomes (mortality and any complications) were Table 1 CPT codes utilized by type of approach Laparoscopic repairs
N
49652
Laparoscopy, surgical, repair, ventral, umbilical, spigelian or epigastric hernia; reducible
9,134
49653
Laparoscopy, surgical, repair, ventral, umbilical, spigelian or epigastric hernia; incarcerated or strangulated
4,195
Data acquisition
49654
Laparoscopy, surgical, repair, incisional hernia; reducible
7,149
The ACS-NSQIP is a national, validated program for measuring risk-adjusted surgical outcomes with the goal of improving the quality of surgical care. The NSQIP database is populated with the information about patient demographics, pre-operative risk factors, pre-operative laboratory values, operative information, and peri-operative and post-operative 30-day outcomes. The ACS-NSQIP program then uses a systematic sampling strategy to create a mixture of patients [19–21]. We performed this study using 2009–2012 data from the ACS-NSQIP database. The study population included patients who had undergone an open or laparoscopic ventral hernia repair as their primary procedure based on CPT codes. Patients with the following CPT codes were included: 49652, 49653, 49654, 49655, 49656, 49657, 49560, 49561, 49565, 49570, 49572, 49585, 49587, and 49590 (Table 1). Emergent cases were excluded. We derived two treatment groups from the above patient selection. The open VHR group consisted of patients with
49655
Laparoscopy, surgical, repair, incisional hernia; incarcerated or strangulated
2,738
49556
Laparoscopy, surgical, repair, recurrent incisional hernia; reducible
2,029
49657
Laparoscopy, surgical, repair, recurrent incisional hernia; incarcerated or strangulated
1,041
Methods
123
Open repairs 49560
Repair initial incisional or ventral hernia; reducible
41,422
49561
Repair initial incisional or ventral hernia; incarcerated or strangulated
15,525
49565
Repair recurrent incisional or ventral hernia; reducible
11,987
49570
Repair epigastric hernia, reducible
3,175
49572
Repair epigastric hernia, incarcerated or strangulated
1,776
49585
Repair umbilical hernia, reducible [5 yrs.
36,528
49587
Repair umbilical hernia, incarcerated or strangulated [5 yrs. Repair spigelian hernia
16,111
49590
879
Surg Endosc
further analyzed using logistic regression. We report odds ratio (OR) with 95 % confidence intervals for unadjusted analyses as well as those adjusted for covariates. Covariates included were those significantly related to outcome at level 0.05 in univariate analyses. Backward and forward selection algorithms included the same variables in all cases. The significance was set at p \ 0.05. All calculations were performed using SAS version 9.2 software (SAS Institute Inc, Cary, NC).
Results Of the patients queried from the dataset, only those with complete records were used for analysis. Between 2009 and 2012, 117,007 patients were identified using NSQIP; 90,721 (77.5 %) patients underwent open VHR and the remaining 26,286 (22.5 %) underwent laparoscopic VHR. Pre-operative characteristics are shown in Table 2. Open cases had more overall pre-operative medical conditions, were more likely to be male, have a history of congestive heart failure, ascites, esophageal varices, and be on dialysis. Laparoscopic cases were more likely to have shortness of breath and hypertension. Table 3 shows pre-operative continuous variables. Open surgery was more likely to be performed on younger patients with a lower BMI. In unadjusted analysis, 30-day mortality was higher in the open VHR group with an odds ratio (OR) of 1.59 (CI 95 % 1.21–2.09); however, mortality did not remain statistically significant in the adjusted model (OR 0.67; CI 95 % 0.39–1.15). The open group had a higher rate of return to the OR, pneumonia, re-intubation, ventilator requirement, renal failure/insufficiency, transfusion, DVT, sepsis, and superficial and deep incisional wound infections (Table 4). In the adjusted model (Table 5), increased overall morbidity in the open VHR group remained statistically significant (OR 1.63; CI 95 % 1.38–1.92). Preoperative patient characteristics that carried an increased rate of morbidity in the adjusted model included current pneumonia (OR 2.48; CI 95 % 1.28–4.81), wound infection (OR 2.69; CI 95 % 2.11–3.43), and transfusion (OR 3.08; CI 95 % 1.62–5.83), as shown in Table 5.
Discussion Ventral hernia remains a common problem encountered in surgical practice. The early reports of laparoscopic repair showed the technique to be safe with similarity in recurrence to open techniques. As methods improved, numerous case series, randomized controlled trials, and meta-analyses began to demonstrate shorter hospital stays, fewer wound infections, better quality of life scores, and longterm durability of laparoscopic repair compared with open
approaches. The first NSQIP data published showed fewer total and infectious complications in the laparoscopic group compared with open repair [17]. Subsequent analyses using 2005–2009 data from NSQIP again demonstrated benefits of laparoscopic repair with a low utilization rate of 17 % [18]. In the current study, we found a utilization rate of laparoscopic VHR of 22 %, up only slightly from the previously reported 17 %. The 30-day mortality was higher in open cases than laparoscopic, although there was no significant increase in the adjusted analysis. The adjusted Table 2 Pre-operative categorical patient characteristics Variables
Laparoscopic
Open
Prob
N
%
N
%
12,209
46.5
47730
52.7 \0.0001
Minority
4,871
18.7
19,474
21.7 \0.0001
Alcohol Shortness of breath
404 2,017
2.4 7.7
1,595 6,386
COPD
Male
2.6 7.0
0.118 0.001
1,123
4.3
3,951
4.4
0.561
Current pneumonia
12
0.1
79
0.1
0.050
Ascites
63
0.2
913
1.0 \0.0001
Esophageal varices
16
0.1
181
0.3 \0.0001
History of CHF
61
0.2
302
0.3
0.010
History of MI
22
0.1
74
0.1
0.760
History of PCI
731
4.3
2,609
4.3
0.717
History of cardiac surgery
693
4.1
2,475
4.1
0.736
49
0.3
209
0.3
0.302
12,870
49.0
40,312
172
1.0
636
1.0
0.810
9
0.1
29
0.0
0.759
166
0.6
917
1.0 \0.0001
8 57
0.0 0.3
74 231
0.1 0.4
0.009 0.447 0.051
History of angina HTN History of PVD Rest pain On dialysis Impaired sensorium Hemiplegia
44.4 \0.0001
History of TIA
305
1.8
973
1.6
History of CVA
160
1.0
640
1.1
0.259
CNS tumor
5
0.0
22
0.0
0.694
Paraplegia
17
0.1
104
0.2
0.043
9
0.1
32
0.1
0.961
0.5
0.902
Quadriplegia Disseminated cancer
119
0.5
416
Wound infection
176
0.7
1,446
1.6 \0.0001
Steroid use
608
2.3
2,340
2.6
0.015
Weight loss
96
0.4
353
0.4
0.581
622
2.4
2,652
Transfusion
27
0.1
153
0.2
Chemotherapy
56
0.3
218
0.4
0.630
Radiotherapy
11
0.1
64
0.1
0.143
2
0.0
85
0.2 \0.0001
84 14,651
0.5 55.7
496 47,417
0.8 \0.0001 52.3 \0.0001
Bleeding disorder
Pregnant Previous operation Any preop condition
2.9 \0.0001 0.016
123
Surg Endosc Table 3 Pre-operative continuous characteristics
Variables
Laparoscopic N
N
26,286
Age
26,286
Mean
SD
N
55.0
13.9
90,721
Mean
SD
equal
53.9
14.8
\0.0001
90,721
Variances
BMI
26,011
33.4
7.9
89,450
32.0
7.9
\0.0001
20,314
139.3
2.7
65,393
139.2
2.9
\0.0001
Pre-operative BUN
19,580
16.0
8.2
62,947
16.6
9.4
\0.0001
Pre-operative serum creatinine
20,327
1.0
0.7
65,380
1.0
0.9
\0.0001
Pre-operative serum albumin
11,229
4.0
0.5
37,235
4.0
0.6
\0.0001
Pre-operative total bilirubin
11,251
0.6
0.6
37,910
0.7
0.7
\0.0001
Pre-operative SGOT
11,360
27.3
23.0
38,596
28.3
25.4
0.000
Pre-operative alkaline phosphatase
11260
82.2
35.7
37,959
84.8
44.2
\0.0001
Pre-operative WBC Pre-operative hematocrit
20,367 21,122
7.5 40.6
2.5 4.5
66,097 68,945
7.6 40.5
3.0 4.9
\0.0001 0.000
Pre-operative platelet count
\0.0001
20,320
244.3
71.7
65,949
240.7
75.9
Pre-operative PTT
5,664
29.6
5.9
20,678
29.8
6.4
0.046
Pre-operative INR
6,750
1.1
0.3
24,938
1.1
0.3
\0.0001
Pre-operative PT
4,104
12.5
3.2
15,516
12.8
3.3
\0.0001
Laparoscopic
Open
N
N
%
Prob
Table 5 Predictive pre-operative characteristics associated with increased morbidity Odds ratio estimates
%
Effect Mortality
p-values
Pre-operative serum sodium
Table 4 Post-operative morbidity Variable
Open
Return to OR
365
1.4
1,803
2.0
\0.0001
Pneumonia
141
0.5
639
0.7
0.0032
Open
1.63
1.38
1.92
Re-intubation
135
0.5
592
0.7
0.0116
Age
1.01
1.01
1.01
57
0.2
222
0.2
0.4148
BMI
1.03
1.02
1.03
5
0.0
94
0.1
\0.0001
BUN
1.01
1.01
1.02
Renal failure
25
0.1
198
0.2
\0.0001
Albumin
0.61
0.55
0.67
Renal insufficiency
35
0.1
208
0.2
0.0026
AST
1.00
1.00
1.00
217 39
0.8 0.1
757 133
0.8 0.1
0.8889 0.9476
WBC
1.06
1.04
1.07
HCT
0.97
0.96
0.98
MI
50
0.2
140
0.2
0.2031
PT
1.03
1.01
1.05
Transfusion
27
0.1
153
0.2
0.0163
Male
0.87
0.77
0.99
0
0.0
9
0.0
0.1063
SOB
1.37
1.17
1.62
DVT
62
0.2
300
0.3
0.0148
Pneumonia
2.48
1.28
4.81
Sepsis
135
0.5
789
0.9
\0.0001
CHF
1.98
1.25
3.14
Ventilator
Urinary tract infection Cardiac arrest
Graft
Septic shock Superficial incisional infection Deep incisional infection Organ space infection No complication
0.37
95 % Wald
0.23
Pulmonary embolism
334
Point estimate
61
0.0008
72
0.3
311
0.3
0.0851
168
0.6
2,173
2.4
\0.0001
52
0.2
788
0.9
\0.0001
102
0.4
434
0.5
0.056
25,108 95.5
83,757 92.3
\0.0001
analysis also showed less overall morbidity associated with laparoscopic repair. Our logarithmic regression analysis of pre-operative factors found that existing pneumonia,
123
Confidence limits
Wound infection
2.69
2.11
3.43
Transfusion
3.08
1.62
5.83
congestive heart failure, wound infection, and pre-operative need for transfusion were associated with increased post-operative complication rates. This suggests that sicker patients with significant medical comorbidities develop more post-operative complications with open VHR. Our findings are consistent with a growing body of literature examining laparoscopic versus open VHR. In a variety of different study designs, fewer complications and
Surg Endosc
decreased LOS have been described. Newer randomized controlled trials have shown positive results but suffer from small sample sizes. Despite these promising reports and an overall movement toward less invasive techniques in the treatment of surgical diseases, our study suggests that the overall utilization of laparoscopic approaches to VHR remains low. Low utilization of laparoscopic VHR is in contrast with the wide use of laparoscopic techniques in many other complex surgical procedures. Ahad et al. reported a 66 % utilization of laparoscopy in splenectomy from 2005 to 2010 NSQIP data [22]. Analysis of adrenalectomy NSQIP data over the same time period by Elfenbein et al. showed a 79 % laparoscopic utilization [23]. In 2012, Simorov et al. reported the utilization of laparoscopic colon resection using the University Health System Consortium administrative database [24]. They found the rate of laparoscopic resection to be 40 % using data from 2008 to 2011. Interestingly, the use of laparoscopy was as high as 18 % in the urgent setting. All of these studies found advantages of laparoscopy similar to ours, including less morbidity and shorter LOS. Taken together, these data demonstrate the use of laparoscopy, even in complex operations, remains significantly higher than in VHR. The 18 % utilization of laparoscopic colectomy in the urgent setting alone was similar to the total use of laparoscopic VHR. The slight increase from 17 to 22 % we found over previous NSQIP data is not on par with other laparoscopic operations. Use of the NSQIP dataset allows for a cross-sectional analysis with large numbers of patients nationwide, and it is validated as a repository of 30-day outcomes. There are a number of limitations of analyses using this dataset. Sampling bias is possible since only three procedures are entered in every 8-day period. Given the prevalence of VHR, it is likely that some cases performed over the study period were not included. Currently, the NSQIP dataset does not include procedure-specific variables such as hernia size, exact location, type, and contents. It is not possible to comment on how those variables would affect the surgeon’s subsequent operative approach. NSQIP only tracks 30-day morbidity and mortality, meaning that we cannot comment on late complications or long-term recurrence. Finally, the dataset only includes patients from those hospitals participating in the ACS-NSQIP program, which may limit our ability to generalize the results. In conclusion, we found that the utilization of laparoscopic VHR remained low from 2009 to 2012 and continued to lag behind the use of laparoscopy in other complex surgical procedures. The mortality rate between laparoscopic and open VHR was similar, but laparoscopic repair was associated with lower overall complication rates. Additionally, we found that some high-risk patients,
as identified by several pre-operative factors, have fewer complications with laparoscopic VHR. Disclosures Chetan V Aher, John C Kubasiak, Shaun C Daly, Imke Janssen, Daniel J Deziel, Keith W Millikan, Jonathan A Myers, and Minh B Luu have no financial ties to disclose.
References 1. LeBlanc KA, Booth WV (1993) Laparoscopic repair of incisional abdominal hernias using expanded polytetrafluoroethylene: preliminary findings. Surg Laparosc Endosc 3:39–41 2. Heniford BT, Park A, Ramshaw BJ, Voeller G (2000) Laparoscopic ventral and incisional hernia repair in 407 patients. J Am Coll Surg 190:645–650 3. Heniford BT, Park A, Ramshaw BJ, Voeller G (2003) Laparoscopic repair of ventral hernias: nine years’ experience with 850 consecutive hernias. Ann Surg 238:391–399 discussion 399–400 4. Park A, Birch DW, Lovrics P (1998) Laparoscopic and open incisional hernia repair: a comparison study. Surgery 124:816–821 discussion 821–812 5. McGreevy JM, Goodney PP, Birkmeyer CM, Finlayson SR, Laycock WS, Birkmeyer JD (2003) A prospective study comparing the complication rates between laparoscopic and open ventral hernia repairs. Surg Endosc 17:1778–1780 6. Lomanto D, Iyer SG, Shabbir A, Cheah WK (2006) Laparoscopic versus open ventral hernia mesh repair: a prospective study. Surg Endosc 20:1030–1035 7. Carbajo MA, Martin del Olmo JC, Blanco JI, de la Cuesta C, Toledano M, Martin F, Vaquero C, Inglada L (1999) Laparoscopic treatment vs open surgery in the solution of major incisional and abdominal wall hernias with mesh. Surg Endosc 13:250–252 8. Pring CM, Tran V, O’Rourke N, Martin IJ (2008) Laparoscopic versus open ventral hernia repair: a randomized controlled trial. ANZ J Surg 78:903–906 9. Asencio F, Aguilo J, Peiro S, Carbo J, Ferri R, Caro F, Ahmad M (2009) Open randomized clinical trial of laparoscopic versus open incisional hernia repair. Surg Endosc 23:1441–1448 10. Itani KM, Hur K, Kim LT, Anthony T, Berger DH, Reda D, Neumayer L (2010) Comparison of laparoscopic and open repair with mesh for the treatment of ventral incisional hernia: a randomized trial. Arch Surg 145:322–328 discussion 328 11. Rogmark P, Petersson U, Bringman S, Eklund A, Ezra E, Sevonius D, Smedberg S, Osterberg J, Montgomery A (2013) Shortterm outcomes for open and laparoscopic midline incisional hernia repair: a randomized multicenter controlled trial: the ProLOVE (prospective randomized trial on open versus laparoscopic operation of ventral eventrations) trial. Ann Surg 258:37–45 12. Pierce RA, Spitler JA, Frisella MM, Matthews BD, Brunt LM (2007) Pooled data analysis of laparoscopic vs. open ventral hernia repair: 14 years of patient data accrual. Surg Endosc 21:378–386 13. Misiakos EP, Machairas A, Patapis P, Liakakos T (2008) Laparoscopic ventral hernia repair: pros and cons compared with open hernia repair. JSLS 12:117–125 14. Forbes SS, Eskicioglu C, McLeod RS, Okrainec A (2009) Metaanalysis of randomized controlled trials comparing open and laparoscopic ventral and incisional hernia repair with mesh. Br J Surg 96:851–858 15. Sajid MS, Bokhari SA, Mallick AS, Cheek E, Baig MK (2009) Laparoscopic versus open repair of incisional/ventral hernia: a meta-analysis. Am J Surg 197:64–72
123
Surg Endosc 16. Sauerland S, Walgenbach M, Habermalz B, Seiler CM, Miserez M (2011) Laparoscopic versus open surgical techniques for ventral or incisional hernia repair. Cochrane Database Syst Rev 3:Cd007781 17. Hwang CS, Wichterman KA, Alfrey EJ (2009) Laparoscopic ventral hernia repair is safer than open repair: analysis of the NSQIP data. J Surg Res 156:213–216 18. Mason RJ, Moazzez A, Sohn HJ, Berne TV, Katkhouda N (2011) Laparoscopic versus open anterior abdominal wall hernia repair: 30-day morbidity and mortality using the ACS-NSQIP database. Ann Surg 254:641–652 19. Khuri SF, Daley J, Henderson W, Hur K, Demakis J, Aust JB, Chong V, Fabri PJ, Gibbs JO, Grover F, Hammermeister K, Irvin G 3rd, McDonald G, Passaro E Jr, Phillips L, Scamman F, Spencer J, Stremple JF (1998) The Department of Veterans Affairs’ NSQIP: the first national, validated, outcome-based, riskadjusted, and peer-controlled program for the measurement and enhancement of the quality of surgical care. National VA Surgical Quality Improvement Program. Ann Surg 228:491–507
123
20. Khuri SF (2005) The NSQIP: a new frontier in surgery. Surgery 138:837–843 21. Khuri SF, Henderson WG, Daley J, Jonasson O, Jones RS, Campbell DA Jr, Fink AS, Mentzer RM Jr, Steeger JE (2007) The patient safety in surgery study: background, study design, and patient populations. J Am Coll Surg 204:1089–1102 22. Ahad S, Gonczy C, Advani V, Markwell S, Hassan I (2013) True benefit or selection bias: an analysis of laparoscopic versus open splenectomy from the ACS-NSQIP. Surg Endosc 27:1865–1871 23. Elfenbein DM, Scarborough JE, Speicher PJ, Scheri RP (2013) Comparison of laparoscopic versus open adrenalectomy: results from American College of Surgeons-National Surgery Quality Improvement Project. J Surg Res 184:216–220 24. Simorov A, Shaligram A, Shostrom V, Boilesen E, Thompson J, Oleynikov D (2012) Laparoscopic colon resection trends in utilization and rate of conversion to open procedure: a national database review of academic medical centers. Ann Surg 256:462–468
and Other Interventional Techniques
The utilization of laparoscopy in ventral hernia repair: an update of outcomes analysis using ACS-NSQIP data Chetan V. Aher • John C. Kubasiak • Shaun C. Daly • Imke Janssen • Daniel J. Deziel • Keith W. Millikan • Jonathan A. Myers • Minh B. Luu
Received: 5 April 2014 / Accepted: 3 August 2014 Ó Springer Science+Business Media New York 2014
Abstract Background Numerous prospective studies and randomized controlled trials have demonstrated shorter length of stay, lower morbidity rates, and similar recurrence rates with laparoscopic ventral hernia repair (VHR) when compared to open VHR. Despite these promising results, previous data showed low utilization of laparoscopic VHR. The aim of our study was to evaluate the utilization of laparoscopic VHR using the most updated information from the American College of Surgeons—National Surgical Quality Improvement Project (NSQIP) dataset. The secondary aim was to evaluate the outcomes from NSQIP for patients undergoing open versus laparoscopic VHR for the outcome of 30-day mortality and the peri-operative morbidities listed in the NSQIP dataset. Methods We performed this study using 2009–2012 data from the ACS-NSQIP database. The study population included patients who had undergone an open or laparoscopic ventral hernia repair as their primary procedure based on CPT codes. Demographic characteristics, overall Presented at the SAGES 2014 Annual Meeting, April 2–5, 2014, Salt Lake City, Utah C. V. Aher (&) J. C. Kubasiak S. C. Daly D. J. Deziel K. W. Millikan J. A. Myers M. B. Luu Department of General Surgery, Professional Building, Suite 810, Rush University Medical Center, 1725 West Harrison Street, Chicago, IL 60612, USA e-mail: [email protected] M. B. Luu e-mail: [email protected] I. Janssen Department of Preventative Medicine, Triangle Office Building, Suite 470, Rush Graduate College, 1700 W. Van Buren Street, Chicago, IL 60612, USA
morbidity, and complications were compared using Chi-square tests for categorical variables and two-sided t tests for continuous variables. Secondary outcomes (mortality and any complications) were further analyzed using logistic regression. Results Utilization of laparoscopic VHR was 22 %. While adjusted mortality was similar, overall morbidity was increased in the open VHR group (OR 1.63; CI 95 % 1.38–1.92). The open group had a higher rate of return to the OR, pneumonia, re-intubation, ventilator requirement, renal failure/insufficiency, transfusion, DVT, sepsis, and superficial and deep incisional wound infections. Conclusions The utilization of laparoscopic VHR remained low from 2009 to 2012 and continued to lag behind the use of laparoscopy in other complex surgical procedures. The mortality rate between laparoscopic and open VHR was similar, but laparoscopic repair was associated with lower overall complication rates. Keywords Ventral hernia repair Laparoscopic surgery NSQIP Mesh hernia repair More than 100,000 ventral hernia repairs (VHR) are performed in the United States each year, resulting in significant economic effects in the form of healthcare cost and lost productivity. Laparoscopic VHR was first described by LeBlanc et al. in 1993 with the goal of shortening recovery time and improving outcomes [1]. Early case series reported shorter length of stay (LOS) than open techniques, low conversion rates, and low recurrence rates [2, 3]. More recently, numerous prospective studies and randomized controlled trials have demonstrated shorter LOS, lower morbidity rates, and similar recurrence rates with laparoscopic VHR when compared to open VHR [4–11]. Pooled
123
Surg Endosc
case series data demonstrated fewer wound infections and lower recurrence in laparoscopic VHR [12], and in 2008, a review by Misiakos et al. reported advantages of laparoscopic VHR including less post-operative pain, shorter recovery period, and better cosmetic results [13]. Two 2009 metaanalyses of the available randomized controlled trials showed that laparoscopic VHR decreased LOS and wound infection rate [14, 15]. Despite these promising results, a Cochrane review showed no difference in complication or recurrence rates between the two techniques [16]. Nationwide data from the American College of Surgeons—National Surgical Quality Improvement Project (ACS-NSQIP) database from 2005 to 2006 were first published by Hwang et al. [17], and then subsequently Mason et al. reported 2005–2009 data. With a larger dataset than any previous study, Mason et al. noted a significant decrease in overall morbidity with laparoscopic VHR. Also noted was a significant decrease in surgical site infections (superficial, deep, and organ/space), pulmonary embolism, and the development of sepsis in both their aggregate dataset and matched cohort. The data showed a 17 % utilization rate of laparoscopic VHR [18]. The aim of our study was to evaluate the utilization of laparoscopic VHR using the most updated information from the NSQIP dataset. The secondary aim was to evaluate the outcomes from NSQIP for patients undergoing open versus laparoscopic VHR for the outcome of 30-day mortality and the peri-operative morbidities were listed in the NSQIP dataset.
CPT codes including 49652, 49653, 49654, 49655, 49656, and 49657. The laparoscopic VHR group consisted of patients with CPT codes including 49560, 49561, 49565, 49570, 49572, 49585, 49587, and 49590. Outcomes The primary outcome was laparoscopic VHR utilization. Secondary outcomes included 30-day mortality and morbidity, which was defined as one of the following ACSNSQIP complications: respiratory (pneumonia, unplanned intubation, pulmonary embolism, or ventilator for [48 h), urinary tract (acute renal failure and progressive renal insufficiency), central nervous system (cerebral vascular accident, coma[24 h, and peripheral nerve injury), cardiac (cardiac arrest requiring CPR and myocardial infarction) and others (transfusion intraoperative/or with in 72 h, vein thrombosis, sepsis, and septic shock). Statistical analyses Demographic characteristics, overall morbidity, and complications were compared using Chi-square tests for categorical variables and two-sided t-tests for continuous variables. Secondary outcomes (mortality and any complications) were Table 1 CPT codes utilized by type of approach Laparoscopic repairs
N
49652
Laparoscopy, surgical, repair, ventral, umbilical, spigelian or epigastric hernia; reducible
9,134
49653
Laparoscopy, surgical, repair, ventral, umbilical, spigelian or epigastric hernia; incarcerated or strangulated
4,195
Data acquisition
49654
Laparoscopy, surgical, repair, incisional hernia; reducible
7,149
The ACS-NSQIP is a national, validated program for measuring risk-adjusted surgical outcomes with the goal of improving the quality of surgical care. The NSQIP database is populated with the information about patient demographics, pre-operative risk factors, pre-operative laboratory values, operative information, and peri-operative and post-operative 30-day outcomes. The ACS-NSQIP program then uses a systematic sampling strategy to create a mixture of patients [19–21]. We performed this study using 2009–2012 data from the ACS-NSQIP database. The study population included patients who had undergone an open or laparoscopic ventral hernia repair as their primary procedure based on CPT codes. Patients with the following CPT codes were included: 49652, 49653, 49654, 49655, 49656, 49657, 49560, 49561, 49565, 49570, 49572, 49585, 49587, and 49590 (Table 1). Emergent cases were excluded. We derived two treatment groups from the above patient selection. The open VHR group consisted of patients with
49655
Laparoscopy, surgical, repair, incisional hernia; incarcerated or strangulated
2,738
49556
Laparoscopy, surgical, repair, recurrent incisional hernia; reducible
2,029
49657
Laparoscopy, surgical, repair, recurrent incisional hernia; incarcerated or strangulated
1,041
Methods
123
Open repairs 49560
Repair initial incisional or ventral hernia; reducible
41,422
49561
Repair initial incisional or ventral hernia; incarcerated or strangulated
15,525
49565
Repair recurrent incisional or ventral hernia; reducible
11,987
49570
Repair epigastric hernia, reducible
3,175
49572
Repair epigastric hernia, incarcerated or strangulated
1,776
49585
Repair umbilical hernia, reducible [5 yrs.
36,528
49587
Repair umbilical hernia, incarcerated or strangulated [5 yrs. Repair spigelian hernia
16,111
49590
879
Surg Endosc
further analyzed using logistic regression. We report odds ratio (OR) with 95 % confidence intervals for unadjusted analyses as well as those adjusted for covariates. Covariates included were those significantly related to outcome at level 0.05 in univariate analyses. Backward and forward selection algorithms included the same variables in all cases. The significance was set at p \ 0.05. All calculations were performed using SAS version 9.2 software (SAS Institute Inc, Cary, NC).
Results Of the patients queried from the dataset, only those with complete records were used for analysis. Between 2009 and 2012, 117,007 patients were identified using NSQIP; 90,721 (77.5 %) patients underwent open VHR and the remaining 26,286 (22.5 %) underwent laparoscopic VHR. Pre-operative characteristics are shown in Table 2. Open cases had more overall pre-operative medical conditions, were more likely to be male, have a history of congestive heart failure, ascites, esophageal varices, and be on dialysis. Laparoscopic cases were more likely to have shortness of breath and hypertension. Table 3 shows pre-operative continuous variables. Open surgery was more likely to be performed on younger patients with a lower BMI. In unadjusted analysis, 30-day mortality was higher in the open VHR group with an odds ratio (OR) of 1.59 (CI 95 % 1.21–2.09); however, mortality did not remain statistically significant in the adjusted model (OR 0.67; CI 95 % 0.39–1.15). The open group had a higher rate of return to the OR, pneumonia, re-intubation, ventilator requirement, renal failure/insufficiency, transfusion, DVT, sepsis, and superficial and deep incisional wound infections (Table 4). In the adjusted model (Table 5), increased overall morbidity in the open VHR group remained statistically significant (OR 1.63; CI 95 % 1.38–1.92). Preoperative patient characteristics that carried an increased rate of morbidity in the adjusted model included current pneumonia (OR 2.48; CI 95 % 1.28–4.81), wound infection (OR 2.69; CI 95 % 2.11–3.43), and transfusion (OR 3.08; CI 95 % 1.62–5.83), as shown in Table 5.
Discussion Ventral hernia remains a common problem encountered in surgical practice. The early reports of laparoscopic repair showed the technique to be safe with similarity in recurrence to open techniques. As methods improved, numerous case series, randomized controlled trials, and meta-analyses began to demonstrate shorter hospital stays, fewer wound infections, better quality of life scores, and longterm durability of laparoscopic repair compared with open
approaches. The first NSQIP data published showed fewer total and infectious complications in the laparoscopic group compared with open repair [17]. Subsequent analyses using 2005–2009 data from NSQIP again demonstrated benefits of laparoscopic repair with a low utilization rate of 17 % [18]. In the current study, we found a utilization rate of laparoscopic VHR of 22 %, up only slightly from the previously reported 17 %. The 30-day mortality was higher in open cases than laparoscopic, although there was no significant increase in the adjusted analysis. The adjusted Table 2 Pre-operative categorical patient characteristics Variables
Laparoscopic
Open
Prob
N
%
N
%
12,209
46.5
47730
52.7 \0.0001
Minority
4,871
18.7
19,474
21.7 \0.0001
Alcohol Shortness of breath
404 2,017
2.4 7.7
1,595 6,386
COPD
Male
2.6 7.0
0.118 0.001
1,123
4.3
3,951
4.4
0.561
Current pneumonia
12
0.1
79
0.1
0.050
Ascites
63
0.2
913
1.0 \0.0001
Esophageal varices
16
0.1
181
0.3 \0.0001
History of CHF
61
0.2
302
0.3
0.010
History of MI
22
0.1
74
0.1
0.760
History of PCI
731
4.3
2,609
4.3
0.717
History of cardiac surgery
693
4.1
2,475
4.1
0.736
49
0.3
209
0.3
0.302
12,870
49.0
40,312
172
1.0
636
1.0
0.810
9
0.1
29
0.0
0.759
166
0.6
917
1.0 \0.0001
8 57
0.0 0.3
74 231
0.1 0.4
0.009 0.447 0.051
History of angina HTN History of PVD Rest pain On dialysis Impaired sensorium Hemiplegia
44.4 \0.0001
History of TIA
305
1.8
973
1.6
History of CVA
160
1.0
640
1.1
0.259
CNS tumor
5
0.0
22
0.0
0.694
Paraplegia
17
0.1
104
0.2
0.043
9
0.1
32
0.1
0.961
0.5
0.902
Quadriplegia Disseminated cancer
119
0.5
416
Wound infection
176
0.7
1,446
1.6 \0.0001
Steroid use
608
2.3
2,340
2.6
0.015
Weight loss
96
0.4
353
0.4
0.581
622
2.4
2,652
Transfusion
27
0.1
153
0.2
Chemotherapy
56
0.3
218
0.4
0.630
Radiotherapy
11
0.1
64
0.1
0.143
2
0.0
85
0.2 \0.0001
84 14,651
0.5 55.7
496 47,417
0.8 \0.0001 52.3 \0.0001
Bleeding disorder
Pregnant Previous operation Any preop condition
2.9 \0.0001 0.016
123
Surg Endosc Table 3 Pre-operative continuous characteristics
Variables
Laparoscopic N
N
26,286
Age
26,286
Mean
SD
N
55.0
13.9
90,721
Mean
SD
equal
53.9
14.8
\0.0001
90,721
Variances
BMI
26,011
33.4
7.9
89,450
32.0
7.9
\0.0001
20,314
139.3
2.7
65,393
139.2
2.9
\0.0001
Pre-operative BUN
19,580
16.0
8.2
62,947
16.6
9.4
\0.0001
Pre-operative serum creatinine
20,327
1.0
0.7
65,380
1.0
0.9
\0.0001
Pre-operative serum albumin
11,229
4.0
0.5
37,235
4.0
0.6
\0.0001
Pre-operative total bilirubin
11,251
0.6
0.6
37,910
0.7
0.7
\0.0001
Pre-operative SGOT
11,360
27.3
23.0
38,596
28.3
25.4
0.000
Pre-operative alkaline phosphatase
11260
82.2
35.7
37,959
84.8
44.2
\0.0001
Pre-operative WBC Pre-operative hematocrit
20,367 21,122
7.5 40.6
2.5 4.5
66,097 68,945
7.6 40.5
3.0 4.9
\0.0001 0.000
Pre-operative platelet count
\0.0001
20,320
244.3
71.7
65,949
240.7
75.9
Pre-operative PTT
5,664
29.6
5.9
20,678
29.8
6.4
0.046
Pre-operative INR
6,750
1.1
0.3
24,938
1.1
0.3
\0.0001
Pre-operative PT
4,104
12.5
3.2
15,516
12.8
3.3
\0.0001
Laparoscopic
Open
N
N
%
Prob
Table 5 Predictive pre-operative characteristics associated with increased morbidity Odds ratio estimates
%
Effect Mortality
p-values
Pre-operative serum sodium
Table 4 Post-operative morbidity Variable
Open
Return to OR
365
1.4
1,803
2.0
\0.0001
Pneumonia
141
0.5
639
0.7
0.0032
Open
1.63
1.38
1.92
Re-intubation
135
0.5
592
0.7
0.0116
Age
1.01
1.01
1.01
57
0.2
222
0.2
0.4148
BMI
1.03
1.02
1.03
5
0.0
94
0.1
\0.0001
BUN
1.01
1.01
1.02
Renal failure
25
0.1
198
0.2
\0.0001
Albumin
0.61
0.55
0.67
Renal insufficiency
35
0.1
208
0.2
0.0026
AST
1.00
1.00
1.00
217 39
0.8 0.1
757 133
0.8 0.1
0.8889 0.9476
WBC
1.06
1.04
1.07
HCT
0.97
0.96
0.98
MI
50
0.2
140
0.2
0.2031
PT
1.03
1.01
1.05
Transfusion
27
0.1
153
0.2
0.0163
Male
0.87
0.77
0.99
0
0.0
9
0.0
0.1063
SOB
1.37
1.17
1.62
DVT
62
0.2
300
0.3
0.0148
Pneumonia
2.48
1.28
4.81
Sepsis
135
0.5
789
0.9
\0.0001
CHF
1.98
1.25
3.14
Ventilator
Urinary tract infection Cardiac arrest
Graft
Septic shock Superficial incisional infection Deep incisional infection Organ space infection No complication
0.37
95 % Wald
0.23
Pulmonary embolism
334
Point estimate
61
0.0008
72
0.3
311
0.3
0.0851
168
0.6
2,173
2.4
\0.0001
52
0.2
788
0.9
\0.0001
102
0.4
434
0.5
0.056
25,108 95.5
83,757 92.3
\0.0001
analysis also showed less overall morbidity associated with laparoscopic repair. Our logarithmic regression analysis of pre-operative factors found that existing pneumonia,
123
Confidence limits
Wound infection
2.69
2.11
3.43
Transfusion
3.08
1.62
5.83
congestive heart failure, wound infection, and pre-operative need for transfusion were associated with increased post-operative complication rates. This suggests that sicker patients with significant medical comorbidities develop more post-operative complications with open VHR. Our findings are consistent with a growing body of literature examining laparoscopic versus open VHR. In a variety of different study designs, fewer complications and
Surg Endosc
decreased LOS have been described. Newer randomized controlled trials have shown positive results but suffer from small sample sizes. Despite these promising reports and an overall movement toward less invasive techniques in the treatment of surgical diseases, our study suggests that the overall utilization of laparoscopic approaches to VHR remains low. Low utilization of laparoscopic VHR is in contrast with the wide use of laparoscopic techniques in many other complex surgical procedures. Ahad et al. reported a 66 % utilization of laparoscopy in splenectomy from 2005 to 2010 NSQIP data [22]. Analysis of adrenalectomy NSQIP data over the same time period by Elfenbein et al. showed a 79 % laparoscopic utilization [23]. In 2012, Simorov et al. reported the utilization of laparoscopic colon resection using the University Health System Consortium administrative database [24]. They found the rate of laparoscopic resection to be 40 % using data from 2008 to 2011. Interestingly, the use of laparoscopy was as high as 18 % in the urgent setting. All of these studies found advantages of laparoscopy similar to ours, including less morbidity and shorter LOS. Taken together, these data demonstrate the use of laparoscopy, even in complex operations, remains significantly higher than in VHR. The 18 % utilization of laparoscopic colectomy in the urgent setting alone was similar to the total use of laparoscopic VHR. The slight increase from 17 to 22 % we found over previous NSQIP data is not on par with other laparoscopic operations. Use of the NSQIP dataset allows for a cross-sectional analysis with large numbers of patients nationwide, and it is validated as a repository of 30-day outcomes. There are a number of limitations of analyses using this dataset. Sampling bias is possible since only three procedures are entered in every 8-day period. Given the prevalence of VHR, it is likely that some cases performed over the study period were not included. Currently, the NSQIP dataset does not include procedure-specific variables such as hernia size, exact location, type, and contents. It is not possible to comment on how those variables would affect the surgeon’s subsequent operative approach. NSQIP only tracks 30-day morbidity and mortality, meaning that we cannot comment on late complications or long-term recurrence. Finally, the dataset only includes patients from those hospitals participating in the ACS-NSQIP program, which may limit our ability to generalize the results. In conclusion, we found that the utilization of laparoscopic VHR remained low from 2009 to 2012 and continued to lag behind the use of laparoscopy in other complex surgical procedures. The mortality rate between laparoscopic and open VHR was similar, but laparoscopic repair was associated with lower overall complication rates. Additionally, we found that some high-risk patients,
as identified by several pre-operative factors, have fewer complications with laparoscopic VHR. Disclosures Chetan V Aher, John C Kubasiak, Shaun C Daly, Imke Janssen, Daniel J Deziel, Keith W Millikan, Jonathan A Myers, and Minh B Luu have no financial ties to disclose.
References 1. LeBlanc KA, Booth WV (1993) Laparoscopic repair of incisional abdominal hernias using expanded polytetrafluoroethylene: preliminary findings. Surg Laparosc Endosc 3:39–41 2. Heniford BT, Park A, Ramshaw BJ, Voeller G (2000) Laparoscopic ventral and incisional hernia repair in 407 patients. J Am Coll Surg 190:645–650 3. Heniford BT, Park A, Ramshaw BJ, Voeller G (2003) Laparoscopic repair of ventral hernias: nine years’ experience with 850 consecutive hernias. Ann Surg 238:391–399 discussion 399–400 4. Park A, Birch DW, Lovrics P (1998) Laparoscopic and open incisional hernia repair: a comparison study. Surgery 124:816–821 discussion 821–812 5. McGreevy JM, Goodney PP, Birkmeyer CM, Finlayson SR, Laycock WS, Birkmeyer JD (2003) A prospective study comparing the complication rates between laparoscopic and open ventral hernia repairs. Surg Endosc 17:1778–1780 6. Lomanto D, Iyer SG, Shabbir A, Cheah WK (2006) Laparoscopic versus open ventral hernia mesh repair: a prospective study. Surg Endosc 20:1030–1035 7. Carbajo MA, Martin del Olmo JC, Blanco JI, de la Cuesta C, Toledano M, Martin F, Vaquero C, Inglada L (1999) Laparoscopic treatment vs open surgery in the solution of major incisional and abdominal wall hernias with mesh. Surg Endosc 13:250–252 8. Pring CM, Tran V, O’Rourke N, Martin IJ (2008) Laparoscopic versus open ventral hernia repair: a randomized controlled trial. ANZ J Surg 78:903–906 9. Asencio F, Aguilo J, Peiro S, Carbo J, Ferri R, Caro F, Ahmad M (2009) Open randomized clinical trial of laparoscopic versus open incisional hernia repair. Surg Endosc 23:1441–1448 10. Itani KM, Hur K, Kim LT, Anthony T, Berger DH, Reda D, Neumayer L (2010) Comparison of laparoscopic and open repair with mesh for the treatment of ventral incisional hernia: a randomized trial. Arch Surg 145:322–328 discussion 328 11. Rogmark P, Petersson U, Bringman S, Eklund A, Ezra E, Sevonius D, Smedberg S, Osterberg J, Montgomery A (2013) Shortterm outcomes for open and laparoscopic midline incisional hernia repair: a randomized multicenter controlled trial: the ProLOVE (prospective randomized trial on open versus laparoscopic operation of ventral eventrations) trial. Ann Surg 258:37–45 12. Pierce RA, Spitler JA, Frisella MM, Matthews BD, Brunt LM (2007) Pooled data analysis of laparoscopic vs. open ventral hernia repair: 14 years of patient data accrual. Surg Endosc 21:378–386 13. Misiakos EP, Machairas A, Patapis P, Liakakos T (2008) Laparoscopic ventral hernia repair: pros and cons compared with open hernia repair. JSLS 12:117–125 14. Forbes SS, Eskicioglu C, McLeod RS, Okrainec A (2009) Metaanalysis of randomized controlled trials comparing open and laparoscopic ventral and incisional hernia repair with mesh. Br J Surg 96:851–858 15. Sajid MS, Bokhari SA, Mallick AS, Cheek E, Baig MK (2009) Laparoscopic versus open repair of incisional/ventral hernia: a meta-analysis. Am J Surg 197:64–72
123
Surg Endosc 16. Sauerland S, Walgenbach M, Habermalz B, Seiler CM, Miserez M (2011) Laparoscopic versus open surgical techniques for ventral or incisional hernia repair. Cochrane Database Syst Rev 3:Cd007781 17. Hwang CS, Wichterman KA, Alfrey EJ (2009) Laparoscopic ventral hernia repair is safer than open repair: analysis of the NSQIP data. J Surg Res 156:213–216 18. Mason RJ, Moazzez A, Sohn HJ, Berne TV, Katkhouda N (2011) Laparoscopic versus open anterior abdominal wall hernia repair: 30-day morbidity and mortality using the ACS-NSQIP database. Ann Surg 254:641–652 19. Khuri SF, Daley J, Henderson W, Hur K, Demakis J, Aust JB, Chong V, Fabri PJ, Gibbs JO, Grover F, Hammermeister K, Irvin G 3rd, McDonald G, Passaro E Jr, Phillips L, Scamman F, Spencer J, Stremple JF (1998) The Department of Veterans Affairs’ NSQIP: the first national, validated, outcome-based, riskadjusted, and peer-controlled program for the measurement and enhancement of the quality of surgical care. National VA Surgical Quality Improvement Program. Ann Surg 228:491–507
123
20. Khuri SF (2005) The NSQIP: a new frontier in surgery. Surgery 138:837–843 21. Khuri SF, Henderson WG, Daley J, Jonasson O, Jones RS, Campbell DA Jr, Fink AS, Mentzer RM Jr, Steeger JE (2007) The patient safety in surgery study: background, study design, and patient populations. J Am Coll Surg 204:1089–1102 22. Ahad S, Gonczy C, Advani V, Markwell S, Hassan I (2013) True benefit or selection bias: an analysis of laparoscopic versus open splenectomy from the ACS-NSQIP. Surg Endosc 27:1865–1871 23. Elfenbein DM, Scarborough JE, Speicher PJ, Scheri RP (2013) Comparison of laparoscopic versus open adrenalectomy: results from American College of Surgeons-National Surgery Quality Improvement Project. J Surg Res 184:216–220 24. Simorov A, Shaligram A, Shostrom V, Boilesen E, Thompson J, Oleynikov D (2012) Laparoscopic colon resection trends in utilization and rate of conversion to open procedure: a national database review of academic medical centers. Ann Surg 256:462–468
