Anatomic Suitability of Ruptured Abdominal Aortic Aneurysms for Endovascular Repair
Article Outline
Mortality from ruptured abdominal aortic aneurysms (rAAAs) remains high despite improvements in anesthesia, postoperative intensive care, and surgical techniques. Recent small series and single-center experiences suggest that endovascular aneurysm repair (EVAR) for rAAAs is feasible and may improve short-term survival. However, the applicability of EVAR to all cases of rAAA is unknown. The purpose of this study was to investigate the anatomical suitability of ruptured aneurysms for EVAR as determined by preoperative cross-sectional imaging. A contemporary consecutive series of rAAAs presenting to a tertiary academic center was retrospectively reviewed. Preoperative radiographic imaging was reviewed and assessed for endovascular compatibility based on currently available EVAR devices. Patients with aneurysm morphology demonstrating neck diameter >32 mm, neck length <10 mm, neck angulation >60 degrees, severe iliac tortuosity, or external iliac diameter <6 mm were deemed noncandidates for EVAR. Forty-seven rAAAs were treated over a 10-year period, with 47% of patients presenting with free rupture and 60% of patients transferred from outside hospitals. Five (11%) patients were treated with EVAR, all over the past 2 years, while the remaining 42 patients underwent open repair. Preoperative imaging was available for review in 43 (91%) patients, and morphological measurements indicated that 49% would have been candidates for EVAR with currently available devices. Criteria precluding EVAR in this cohort were inadequate neck length in 73%, unsuitable iliac access in 23%, large neck diameter in 18%, and severe neck angulation in 14%. Overall 30-day mortality was 34%, and 1-year mortality was 42%. Candidates for EVAR were more likely than non-EVAR candidates to be male (95% vs. 68%, p = 0.046) and to have smaller sac diameters (7.0 vs. 8.5 cm, p = 0.02) and longer neck lengths (24.1 vs. 8.6 mm, p < 0.0001); less likely to have a >60 degree angulated neck (10% vs. 45%, p = 0.0002), larger external iliac diameter (8.9 vs. 7.3 mm, p = 0.015), and less blood loss during surgical repair (2.4 vs. 6.0 L, p = 0.02); and more likely to be discharged home (71% vs. 25%, p = 0.05). There were no differences in 30-day, 1-year, or overall mortality between candidates for EVAR and noncandidates. Only 49% of patients with rAAAs in this consecutive series were found to be candidates for EVAR with conventional stent-graft devices. Differences in demographics, aneurysm morphology, and outcomes between candidates and noncandidates undergoing open repair suggest that differential risks apply to ruptured aneurysm patients. Protocols and future reports of EVAR for rAAAs should be tailored to these results. Device and technique modifications are necessary to increase the applicability of EVAR for rAAAs.
Introduction
Despite improvements in anesthetic management, surgical technique, and postoperative care, the mortality of patients with ruptured abdominal aortic aneurysms (rAAAs) remains high and has not significantly improved over the past three decades.1, 2 Open surgical repair has long been the traditional strategy to treat patients with rAAAs, resulting in mortality rates of approximately 50% after surgical intervention.3 Endovascular repair of aneurysms (EVAR) has emerged as a minimally invasive technique for elective repair of asymptomatic aneurysms.4, 5 Wide adoption of EVAR in many centers as well as improved endovascular techniques, devices, and availability have led to considerable enthusiasm for the endovascular approach to rAAAs.
A number of trials have evaluated EVAR versus conventional open surgical repair for the treatment of rAAA, with the majority consisting of small, retrospective, and nonrandomized case series.6 In these studies, EVAR for ruptured aneurysms (rEVAR) has been shown to be feasible and to reduce perioperative complications and short-term mortality compared to open repair in selected patients.7, 8, 9, 10 There has only been one randomized control study comparing the two techniques in rAAAs, which actually showed no significant difference in outcomes.11 The improvement in outcomes shown in the smaller, nonrandomized studies has been demonstrated in selected patients and generally compared to historical controls in the same institution for open repair. Strategies for generalized adoption of EVAR for rAAAs continue to be refined and will depend on factors such as morphological suitability, surgeon comfort, device availability, and device improvements.
The purpose of the current study was to investigate the anatomical suitability of ruptured aneurysms for endovascular repair in a contemporary consecutive series of patients treated mainly with open repair. We hoped to determine if there were demographic, morphological, or outcome differences in patients who would have been candidates for endovascular repair.
Materials and Methods
Institutional review board approval was obtained for review of patients' records. We performed a retrospective chart review of all consecutive patients who underwent repair of an rAAA at a tertiary academic institution from July 1997 to November 2007. Preoperative cross-sectional radiographic imaging, when available, was retrospectively reviewed in a blinded fashion to patient treatment, course, and outcome in order to assess the anatomical suitability of the patient's aneurysm for EVAR. Criteria for EVAR were based on devices currently available and used routinely in our institution as of January 2008. Neck diameter >32 mm, neck length <10 mm, neck angulation >60 degrees, severe iliac tortuosity, or external iliac diameter <6 mm were designated as reasons that a patient would not be a candidate for EVAR. Standard reporting standards for EVAR characteristics were utilized as outlined by the Society for Vascular Surgery.12 Other demographic, morphological, and outcome data collected for the cohort included age, gender, presence of free rupture, type of operation, length of stay, estimated blood loss, postoperative complications, 30-day and 1-year mortality, long-term follow-up, and disposition on discharge (home or skilled nursing facility).
Descriptive statistics were calculated for all variables. Continuous data are reported as mean ± standard deviation, and categorical data are reported as percentages. Bivariate statistical techniques, including the Wilcoxon rank sum test and Fisher's exact test, were used when appropriate. Independent group t-tests were used to test mean differences in outcomes between candidates and noncandidates for rEVAR. Statistical significance was defined by p ≤ 0.05. Kaplan-Meier analysis was performed to determine overall survival after surgical intervention. Statistical analyses were performed using MedCalc version 9.2.1.0 (MedCalc Software, Mariakerke, Belgium).
Results
Forty-seven patients (83% male) with rAAA underwent repair over a 10-year period. The demographic characteristics of the patients and morphological features of their AAAs are listed in Table I. In this cohort of patients, 47% presented with free rupture and 60% were transferred from an outside hospital. The main study cohort consisted of the 43 patients who had cross-sectional imaging prior to operation that was available for this retrospective review. Four patients did not have imaging that was reviewable or did not undergo cross-sectional imaging prior to their surgery, and all underwent open repair. Five patients (11%) who had preoperative imaging were treated with EVAR, all within the last 2 years, while the remainder of the patients underwent open repair via transperitoneal incision. Over the 10-year study period, the annual number of rAAA patients did not fluctuate significantly (three to six per year).
Table I. Demographic characteristics and morphological features of 47 consecutive rAAAs
| Mean | SD | Range | |
|---|---|---|---|
| Patient demographics | |||
 Age at presentation (years) | 72.2 | 10.8 | |
| % Over 80 years old | 23% | ||
| % Male | 83% | ||
| % Free rupture | 47% | ||
| % EVAR | 11% | ||
| % Transferred from outside hospital | 60% | ||
| AAA morphological features | |||
| AAA sac diameter (mm) | 76.9 | 19.5 | 40-130 |
| Neck diameter (mm) | 24.1 | 6.4 | 16-35 |
| Neck length (mm) | 16.3 | 11.4 | 0-41 |
| % Neck angulation >60 degrees | 25% | ||
| Common iliac diameter (mm) | 16.5 | 7.4 | 7-41 |
| External iliac diameter (mm) | 8.2 | 2.0 | 3-13 |
| % Severe iliac tortuosity | 6% | ||
| Outcomes | |||
| Length of stay (days) | 14.1 | 9.1 | 4-40 |
| Estimated blood loss (mL) | 3,945 | 4,181 | 100-15,000 |
| 30-day mortality (%) | 34% | ||
| 1-year mortality (%) | 42% | ||
| Overall mortality (%) | 57% | ||
| % Discharged home | 50% | ||
| % Complications (major and minor) | 45% | ||
| Mean length of follow-up (months) | 27.6 | 33.6 | 1-105 |
Overall 30-day mortality of the entire cohort was 34%, and 1-year mortality was 42%. At a mean follow-up time of 27.6 ± 33.6 months (range 1-105), 43% are still alive. Of the 29 patients who survived their surgical intervention for rAAA and were discharged from the hospital, mean follow-up time was 42.2 months. Kaplan-Meier survival curves for overall mortality rates are shown in Figure 1. Median survival time for the entire cohort was 34 months. Perioperative complications for those who survived 30 days included renal compromise (21%), renal failure (14%), pulmonary failure (14%), lower extremity ischemia (14%), myocardial infarction (10%), and ischemic bowel (10%).
Fig. 1
A Kaplan-Meier survival curve showing freedom from all-cause mortality and overall survival after rAAA for the entire patient cohort (n = 47). Standard errors of the mean are shown in the table out to 8-year follow-up. B Kaplan-Meier survival curves comparing candidates for EVAR and nonsuitable candidates with available preoperative cross-sectional imaging (n = 43). There is no statistically significant difference in overall survival between candidates and noncandidates (p = 0.99).
Of the 43 patients who had preoperative imaging and were therefore classified as candidates versus noncandidates for EVAR, 49% could have been treated using devices available currently. The other half of the patients with preoperative imaging would not have been candidates for EVAR, and Table II delineates the reasons for this classification. The most common exclusion criterion from being an EVAR candidate was a short neck length <10 mm (73%). Other reasons for unsuitability for EVAR included prohibitively small external iliac artery access (23%), wide neck diameter >32 mm (18%), and severe neck angulation >60 degrees (14%).
Table II. Reasons for unsuitability of EVAR in 22 patients deemed noncandidates for endovascular repair of rAAA
| Individual morphological criteria | |
|---|---|
| Neck length <10 mm | 73% |
| External iliac diameter <6 mm | 23% |
| Neck diameter >32 mm | 18% |
| Neck angulation >60 degrees | 14% |
| Total number of factors | |
| 1 | 77% |
| 2 | 18% |
| 3 | 4% |
There were several important differences between the groups of candidates and noncandidates for EVAR, which are depicted in Table III. From a demographic standpoint, age, percentage of patients presenting with free rupture, and percentage of patients transferred from an outside institution had no bearing on candidacy for EVAR. Candidates for EVAR were much more likely to be male (95% vs. 68%, p = 0.046). Obviously, those who were candidates included the five patients who did undergo EVAR in the past 2 years, making that statistically significant.
Table III. Comparison of demographics, aneurysm morphology, and outcomes of entire cohort of 43 patients treated who had cross-sectional imaging available for review
| Candidates (n = 21) | Noncandidates (n = 22) | p | |
|---|---|---|---|
| Patient demographics | |||
| Age at presentation (years) | 71.7 | 71.7 | 0.98 |
| % over 80 years old | 33% | 14% | 0.16 |
| % Male | 95% | 68% | 0.046 |
| % Free rupture | 33% | 54% | 0.22 |
| % EVAR | 24% | 0% | 0.02 |
| % Transferred from outside hospital | 57% | 64% | 0.76 |
| AAA morphological features | |||
| AAA sac diameter (mm) | 69.9 | 84.9 | 0.02 |
| Neck diameter (mm) | 24 | 25.7 | 0.34 |
| Neck length (mm) | 24.1 | 8.6 | <0.0001 |
| % Neck angulation >60 degrees | 10% | 45% | 0.0002 |
| Common iliac diameter (mm) | 17.3 | 15.6 | 0.50 |
| External iliac diameter (mm) | 8.9 | 7.3 | 0.015 |
| % Severe iliac tortuosity | 5% | 9% | 0.96 |
| Outcomes | |||
| Length of stay (days) | 12.1 | 15.3 | 0.37 |
| Estimated blood loss (mL) | 2,456 | 6,055 | 0.02 |
| 30-day mortality (%) | 29% | 36% | 0.75 |
| 1-year mortality (%) | 38% | 45% | 0.76 |
| Overall mortality (%) | 62% | 54% | 1.0 |
| % Discharged home | 71% | 25% | 0.05 |
| % Complications (major and minor) | 43% | 45% | 1.0 |
| Mean length of follow-up (months) | 27 | 28 | 0.89 |
From a morphological standpoint, candidates versus noncandidates had a significantly smaller AAA sac diameter (7.0 vs. 8.5 cm, p = 0.02), longer neck length (24.1 vs. 8.6 mm, p < 0.0001), less neck angulation, and larger external iliac diameters (8.9 vs. 7.3 mm, p = 0.015). Mean neck diameter, common iliac diameter, and iliac tortuosity were not different between the groups.
Peri- and postoperative outcomes were different between the candidate and noncandidate groups (Table III). Although there was a trend toward slightly decreased 30-day and 1-year mortality in the candidate group, it was not statistically significantly. Figure 1B shows Kaplan-Meier survival analysis between the two groups for overall survival, with no difference in long-term outcomes between the groups (p = 0.99). However, estimated blood loss was reduced (2.4 vs. 6.0 L, p = 0.02), and the percentage of patients discharged home (71% vs. 25%, p = 0.05) was significantly greater among patients who were considered candidates. After reanalyzing the data excluding the five patients who had undergone EVAR and having a cohort of 38 patients with preoperative imaging who underwent open repair, most of the above differences still held true (Table IV). With the exclusion of the EVAR patients, estimated blood loss was similar statistically between candidates and noncandidates but the percentage of patients discharged home remained significantly higher in the candidate group. Major and minor postoperative complications were similar between the groups including rates of postoperative cardiac events, infection, renal insufficiency, and renal failure.
Table IV. Comparison of demographics, aneurysm morphology, and outcomes of cohort of 38 patients treated with open repair of rAAA with cross-sectional imaging available for review
| Candidates (n = 16) | Noncandidates (n = 22) | p | |
|---|---|---|---|
| % Free rupture | 31% | 54% | 0.27 |
| AAA sac diameter (mm) | 68.7 | 84.9 | 0.02 |
| Neck length (mm) | 24.5 | 8.2 | <0.0001 |
| % Neck angulation >60 degrees | 6% | 45% | 0.02 |
| External iliac diameter (mm) | 9.2 | 7.3 | 0.01 |
| Length of stay (days) | 12.2 | 15.3 | 0.4 |
| Estimated blood loss (mL) | 3,246 | 6,055 | 0.11 |
| 30-day mortality (%) | 19% | 36% | 0.42 |
| 1-year mortality (%) | 31% | 45% | 0.59 |
| Overall mortality (%) | 56% | 54% | 1.0 |
| % Discharged home | 75% | 25% | 0.04 |
| % Complications (major and minor) | 44% | 45% | 1.0 |
Discussion
In this contemporary single-institution study we report the anatomical suitability of EVAR for rAAAs to be 49%. This suggests that approximately one-half of patients presenting with rAAAs are not good endovascular candidates with currently approved devices and highlights the need for refinement of protocols, devices, and techniques to optimize the care of these patients. These results confirm the findings of several retrospective studies conducted in Europe.13, 14
Several differences in terms of demographics, AAA morphology, and peri- and postoperative outcomes are also demonstrated when we separate rAAA patients into groups based on whether they would have been candidates for EVAR. This suggests that patients with rAAA who are endovascular candidates are potentially less challenging open surgical cases than those who are not candidates for EVAR. Potential explanations for this finding relate to those patients having aneurysms with smaller AAA diameters, longer necks, and larger iliac anatomy. The presence of these particular morphological factors intuitively would make open repair easier.
Because of these particular morphological factors in the candidate group, blood loss is likely to be slightly less and there would be less need for suprarenal or supraceliac control. Even after removing those patients who did undergo EVAR in our series, the percentage of patients discharged to home after open repair remained significantly higher in the candidate group. This finding related to postoperative course further corroborates the hypothesis that candidates for EVAR, even if undergoing open repair, may have a more benign course. This will have to be considered in future studies that compare endovascular treatment of rAAAs to historical controls since it may be most accurate to compare to historical controls that would have been candidates for EVAR. There is an abundance of literature to suggest that even for elective EVAR smaller aneurysms do better in terms of freedom from rupture, secondary intervention, and sac shrinkage rates.6, 13, 14
Mortality from rAAAs certainly remains high, with reported rates if untreated of approximately 80-90%, and strategies for the future need to be adopted to improve on this morbid condition.15 Traditionally, open surgical repair was the only option for effective treatment of rAAAs. However, open repair results in substantial mortality, ranging 40-70%, and morbidity, primarily from hemorrhage, operative insults, and aortic cross-clamping leading to ischemic injury.16 The high mortality associated with open repair of rAAA coupled with enthusiasm for EVAR certainly led to the “endo-exuberance” for treatment of rAAAs.
In addition, there are decreased physiological adverse effects with EVAR, particularly to the cardiac, respiratory, and renal systems, as well as a reduced inflammatory response.17, 18, 19, 20 Thus, with the progressively improved outcomes using this technique as well as technological enhancements in endovascular devices, utilization of EVAR has been expanded for treatment of rAAAs. It has been theorized that the decreased hemodynamic and metabolic stresses shown with elective EVAR will translate into improved outcomes for patients with rAAA treated with EVAR.21
Feasibility of EVAR for rAAAs has been established in a number of studies.7, 8, 9, 10 In a metanalysis by Harkin et al.6 of 33 nonrandomized studies, the authors summarized that EVAR for rAAAs is possible in selected patients, with a trend toward reductions in blood loss, duration of intensive care treatment, early complications, and mortality. The limitation of the majority of current studies in the literature is that they compare the mortality rate of EVAR for rAAAs to that of historical open repair controls. There has only been one randomized control study of EVAR versus open repair for rAAA.11 In this study, the authors found that there was no significant difference in mortality or postoperative complication rates in the open and endovascular groups, differing from their own initial selected series and others' previous experience with endovascular repair.
The favorable results in the literature for rEVAR may therefore be primarily due to the fact that the comparisons of mortality and complication rates are made from a very select group undergoing EVAR to historical controls of all rAAAs in the same institution, many of whom would not have been candidates for EVAR and probably would have fared worse. These comparisons may not be as valid, and more data and reports from high-volume centers will be necessary to truly determine if EVAR will become the new standard for treatment of rAAAs.
The very reasons that some patients are not candidates for EVAR may be the same reasons that they are at significantly increased risk for open operative repair. This is evidenced by both the previous findings of more challenging aneurysm morphology in ruptured aneurysms as well as the fact that high-risk patients had no advantage with EVAR in elective repair.22 This theory is also supported by the results of a study by Lee et al.,23 in which the authors compared AAA morphology from patients with ruptured or symptomatic aneurysms to patients undergoing elective asymptomatic repair. This study found that the anatomical eligibility of EVAR for patients presenting with ruptured/symptomatic AAA was significantly smaller than for patients with asymptomatic AAA due to unfavorable proximal neck anatomy. This hypothesis is corroborated by our current findings.
Other factors besides anatomy have been studied to assess the applicability of EVAR to rAAAs. In a recent meta-analysis it was found that the mortality benefit from EVAR compared to open surgery for rAAA was directly related to the patient's hemodynamic condition at presentation.24 This seems to indicate that the selection bias for patients undergoing EVAR, typically only when hemodynamically stable, would favor results after EVAR compared to open repair in the same institution. Logistic reasons, such as availability of endovascular equipment and staff, are often cited as the reasons that open surgery is performed on the hemodynamically unstable patient. Development of emergency room protocols for the rapid assessment and triage of rAAA patients can potentially increase the utilization of EVAR and ultimately improve patient outcomes. This has been reported in several series that have instituted a multidisciplinary approach for rAAA, including vascular surgeons, emergency room physicians, anesthesiologists, radiologists, operating room staff, and technicians.25, 26 Once this standardized protocol was established, significant improvement in mortality was achieved.
There are several limitations to the current study. This was a retrospective study which relied upon the accuracy of the data recording and collection. In addition, the eligibility for rEVAR of patients in this cohort was based on current suitability criteria for endovascular techniques in 2008. Certainly, we have improved our own endovascular techniques over the years so that many times we are able to treat patients without ideal anatomy due to accumulated experience with elective EVAR. Thus, the knowledge gained as well as device improvements were retrospectively applied to patients with rAAAs presenting over 10 years. It is possible that the suitability of EVAR for this decade-long experience of rAAAs is slightly over estimated due to advances in surgeon experience and device improvements.
Conclusions
Although there is significant enthusiasm for utilizing EVAR for ruptured aneurysms, fueled in part by favorable results from initial, small studies, caution must be used before this technique is widely adopted. In this study, only one-half of the patients were suitable candidates for EVAR by today's standard available devices. Modification of stent-graft systems that allow deployment in patients with shorter necks and more difficult iliac access should improve the applicability of EVAR for rAAAs in the future. Differences in demographics, aneurysm morphology, and outcomes between candidates and noncandidates undergoing open repair suggest that differential risks apply to ruptured aneurysm patients. Protocols and future reports of EVAR for rAAAs should be tailored to these results.
References
- Two decades of abdominal aortic aneurysm repair: have we made any progress?. J Vasc Surg. 2000;32:1091–1100
- . In-hospital operative mortality of ruptured abdominal aortic aneurysm: a population-based analysis of 5593 patients in The Netherlands over a 10-year period. Eur J Vasc Endovasc Surg. 2005;30:359–364
- . A meta-analysis of 50 years of ruptured abdominal aortic aneurysm repair. Br J Surg. 2002;89:714–730
- Comparison of endovascular aneurysm repair with open repair in patients with abdominal aortic aneurysm (EVAR trial 1), 30-day operative mortality results: randomised controlled trial. Lancet. 2004;364:843–848
- A randomized trial comparing conventional and endovascular repair of abdominal aortic aneurysms. N Engl J Med. 2004;351:1607–1618
- Endovascular ruptured abdominal aortic aneurysm repair (EVRAR): a systematic review. Eur J Vasc Endovasc Surg. 2007;34:673–681
- Impact of endovascular repair on early outcomes of ruptured abdominal aortic aneurysms. J Vasc Surg. 2004;40:211–215
- Ruptured abdominal aortic aneurysm: endovascular treatment. Abdom Imaging. 2005;30:263–269
- Early and mid-term results of ruptured abdominal aortic aneurysms in the endovascular era in a community hospital. J Vasc Surg. 2007;46:898–905
- Endograft treatment of ruptured abdominal aortic aneurysms using the Talent aortouniiliac system: an international multicenter study. J Vasc Surg. 2006;43:1111–1123
- . A randomised trial of endovascular and open surgery for ruptured abdominal aortic aneurysm—results of a pilot study and lessons learned for future studies. Eur J Vasc Endovasc Surg. 2006;32:506–514
- Reporting standards for infrarenal endovascular abdominal aortic aneurysm repair. J Vasc Surg. 1997;25:405–410
- Comparison of morphologic features of intact and ruptured aneurysms of infrarenal abdominal aorta. J Vasc Surg. 2003;38:88–92
- Ruptured abdominal aortic aneurysm: endovascular repair is feasible in 40% of patients. Eur J Vasc Endovasc Surg. 2003;26:479–486
- . Ruptured abdominal aortic aneurysm: a population-based study. J Vasc Surg. 1993;18:74–80
- Endovascular treatment for ruptured abdominal aortic aneurysm. Cochrane Database Syst Rev. 2007;CD005261-CD005261
- Randomized study comparing cardiac response in endovascular and open abdominal aortic aneurysm repair. Br J Surg. 2001;88:1059–1065
- Haemodynamic and metabolic response to endovascular repair of infra-renal aortic aneurysms. Br J Anaesth. 1996;77:581–585
- Improved respiratory function and analgesia control after endovascular AAA repair. J Endovasc Surg. 1997;4:62–65
- Endovascular AAA repair attenuates the inflammatory and renal responses associated with conventional surgery. J Endovasc Ther. 2000;7:359–371
- . The endovascular management of ruptured abdominal aortic aneurysms. Eur J Vasc Endovasc Surg. 2003;25:191–201
- EVAR Trial Participants Endovascular aneurysm repair and outcome in patients unfit for open repair of abdominal aortic aneurysm (EVAR trial 2): randomised controlled trial. Lancet. 2005;365:2187–2192
- Eligibility rates of ruptured and symptomatic AAA for endovascular repair. J Endovasc Ther. 2002;9:436–442
- Ruptured abdominal aortic aneurysms: endovascular repair versus open surgery—systematic review. Radiology. 2007;245:122–129
- Establishing a protocol for endovascular treatment of ruptured abdominal aortic aneurysms: outcomes of a prospective analysis. J Vasc Surg. 2006;44:1–8
- Improved survival after introduction of an emergency endovascular therapy protocol for ruptured abdominal aortic aneurysms. J Vasc Surg. 2007;45:443–450
Presented at the Annual Winter Meeting of the Peripheral Vascular Surgical Society, Snowmass, CO, February 1-3, 2008.
PII: S0890-5096(08)00194-5
doi:10.1016/j.avsg.2008.06.001
© 2008 Annals of Vascular Surgery Inc. Published by Elsevier Inc All rights reserved.
