Risk factors for readmission after open abdominal aortic aneurysms repair and its outcome in chronic kidney disease patients

Abstract

Objective

Readmission after vascular procedures is a burden to hospitals and the Medicare system. Therefore, identifying risk factors leading to readmission is vital. We examined the frequency of and risk factors for 30-day readmission after open aneurysm repair (OAR) and explored post-operative outcomes with special attention for those with preexisting chronic kidney disease (CKD).

Methods

Patients who underwent OAR were identified in the National Readmission Database (2016–2018). Demographic information and comorbidities were collected. Patients readmitted within 30 days after their index hospitalization were identified and compared to patients without readmission records.

Results

A total of 5090 patients underwent OAR during the study timeframe with 488 patients (9.6%) were readmitted within 30 days. Females were more readmitted than males (F = 11.1% vs M = 9.0%, P < 0.001). Readmitted patients had more comorbidities (median ECI 12, P < 0.05), were on Medicare (73.7%, P < 0.001), had higher surgery admission cost ($146,844, P < 0.001), longer length of stay (8 days, P < 0.001), and were discharged to a lower level care facility (62.7%, P < 0.001). Comorbidities that predisposed patients for readmission include: peripheral arterial disease (OR 2.15, P < 0.01), asthma (OR 1.87, P < 0.01), chronic heart failure (OR 1.74, P < 0.05). On readmission visit, acute renal failure (23.8%) was the most common diagnosis, while intestinal surgery (13.7%) was the most common procedure. Patients with CKD (n = 968, 18.9% of total population) had double the mortality rate compared to non-CKD patients on surgery admission (10.4%, P < 0.001) and readmission (10.1%, P < 0.001).

Conclusion

Certain factors were noted to increase readmission rate, special attention need to be paid when dealing with such group of patients requiring OAR. Vascular surgeons should meticulously weigh benefits and risks when considering OAR in patients with CKD who are not a candidate for endovascular repair, and optimize their kidney function before considering such approach.

Keywords

Open aneurysm repair risk factors readmissions unplanned chronic kidney disease nationwide

Introduction

Abdominal aortic aneurysms (AAA) affect approximately 5% of men and 0.7% of women.^1,2 Indications for repair are well established.³ Traditional aneurysm repair was done using open surgical techniques. Endovascular aneurysm repair (EVAR) was described in the early 1990s.⁴ Since that time, there has been an exponential increase in aneurysms repaired with endovascular techniques.^5,6 This is largely explained by the reduced hospital length of stay, short term morbidity and mortality associated with endovascular repair.⁷ The 2-year survival is comparable with both repair techniques.^8–10 However, recent reports in the literature have questioned the long-term durability of EVAR. Over the long run, the endovascular group had more aneurysm-related secondary interventions,¹¹ and more delayed aneurysm-related mortality.¹² Open aneurysm repair (OAR) is a salvage technique for failure of endovascular aneurysm repair.^13–15

The outcomes of aneurysm repair in patients with impaired renal function are an area of continuous investigation. OAR is associated with a higher risk of acute kidney injury when compared to EVAR.¹⁶ Retrospective studies have shown that patients with chronic kidney disease (CKD) who undergo aneurysm repair experience a decline in their creatinine clearance after several years.¹⁷ This decline is greater in patients undergoing EVAR and is more pronounced in those undergoing suprarenal fixation.¹⁸ It is well known that post-operative renal complication is associated with increased odds of readmission after elective aneurysm repair.¹⁹ Post-operative readmission to the hospital is a known risk factor for increased mortality.¹⁹ Our goal in this study is to examine the frequency of and risk factors for 30-day readmission after OAR and explore post-operative outcomes with special attention to those with preexisting CKD.

Methods

Data collection

This study utilized the most recent 3-year release (2016–2018) of U.S. Healthcare Utilization Project’s (HCUP) Nationwide Readmission Database (NRD) for study candidates. Nationwide Readmission Database data includes 28 geographically dispersed States, accounting for 60% of the total U.S. resident population and 59% of all U.S. hospitalizations.²⁰ The database can capture all readmissions despite where the patients present post procedure as long as the readmission is within the same state of first admission.²⁰ However, the database would not track the patients readmitted in another state, or readmitted cross calendar years.²⁰ The International Classification of Diseases 10th edition Clinical Modification (ICD-10-CM) diagnosis and procedure codes, Diagnosis Related Group (DRG) codes, Major Diagnostic Category (MDC) codes, are used in this study. Standard coding criterion from Charlson Comorbidity Index (CCI)²¹ and Elixhauser Comorbidity Index (ECI)²² comorbidity measures were applied to determine the patients’ comorbidities, outcomes, and demographic information. Other specific abdominal aortic aneurysm-related comorbidities were selected based on physicians’ medical expertise. Institutional Review Board approval was waived because this was a database study that used deidentified data. Informed consent was not required due to the nature of the study. The specific codes used for each of these parameters are provided in (Supplemental Table 1).

Patient selection

Patients 18 years and older, with diagnosis of AAA without rupture (ICD-10-CM, I714) were preselected. Since we aimed to study 30-day readmission after intervention, patients admitted in December were excluded from this study due to the database limitation of being unable to track patients across years.²⁰ Patients were assigned to readmission (RA) group and non-readmission (Non-RA) group based on readmission records. This study focused on patients who underwent OAR. Patients who underwent endovascular repair and cases that were converted to open procedures were excluded.

Statistical analysis

All analysis was prepared by statistical software SPSS and R, database related work was done by SQL under “sqldf” R package. Empirical cumulative distribution function of readmission day was made by R. Numerical variables including age, length of stay (LOS), total charge, Charlson Comorbidity Index and Elixhauser Comorbidity Index, were described by median and interquartile ranges (IQR). These variables were not normally distributed, and differences between non-RA and RA group were analyzed by Wilcoxon signed-rank test without assumption of parametric distribution. Total charges at patient discharge day from each year have been adjusted to medical care Consumer Price Index (CPI) 2020 before analysis. Binary variables gender, admission type, ER admission, disposition, and all the comorbidity status were analyzed by chi-square test. Information of primary payer, household income, and hospital characteristics were analyzed by chi-square test for independence. For all statistical tests in this study, P < 0.05 is deemed to be significant.

Results

General population demographics and characteristics

Patients who underwent open or endovascular repair for unruptured AAA totaled to 56,905. However, patients who were admitted in December of each year or had an endovascular repair, were excluded from the study. A total of 5090 patients were analyzed in this study with 488 patients (9.6%) readmitted within 30 days after discharge (Figure 1). Baseline characteristics of patients admitted for OAR are shown in (Table 1).

Figure 1.

Diagram of candidate selection and study design.

Table 1.

Characteristics of patients admitted for open repair of abdominal aortic aneurysm.

	Open AAA repair	Non-RA	RA	% RA	PP
	(n = 5090)	(n = 4602)	(n = 488)	9.6%
Age (years)	70 (64–76)	70 (64–76)	70 (65–76)		NS
Gender					<0.05
Male	3664 (72.0%)	3334	330	9.0%
Female	1426 (28.0%)	1268	158	11.1%
CCI^a	2 (1–3)	2 (1–3)	2 (2–4)		<0.05
1–2	2967 (58.3%)	2715	252
3–4	1643 (32.3%)	1375	268
≥5	580 (11.4%)	512	68
ECI^a	11 (2–19)	11 (2–19)	12 (4.75–21.25)		<0.001
≤0	252 (5%)	231	21
1–4	1124 (22.1%)	1041	83
≥5	3714 (73%)	3330	384
Length of stay (LOS)^c	7 (5–10)	7 (5–10)	8 (6–12)		<0.001
Primary payer					<0.001
Medicare	3588 (70.5%)	3230	358	10.0%
Private insurance	1041 (20.5%)	966	75	7.2%
Other (medicaid or self-pay)	452 (8.9%)	399	53	11.7%
Admission cost	$129,095 (85,580–2127,14)	$127,442 (84,986–2101,64)	$146,844 (92,408–2348,08)		<0.001
Household income					NS
0–25th percentile	1313 (26.2%)	1179	134	10.2%
26th to 50th percentile	1409 (28.2%)	1259	150	10.6%
51st to 75th percentile	1343 (26.8%)	1231	112	8.3%
76th to 100th percentile	938 (18.7%)	853	85	9.1%
Admission type					NS
Non-elective	1164 (22.9%)	1037	127	10.9%
Elective	3901 (76.6%)	3543	358	9.2%
Admission					NS
Non-ED	4348 (85.4%)	3945	403	9.3%
Emergency department (ED)	742 (14.6%)	657	85	11.5%
Discharge					<0.001
Home	2441 (48%)	2259	182	7.5%
Other^b	2649 (52%)	2343	306	11.6%
Hospital size					NS
Small	409 (8%)	375	34	8.3%
Medium	1145 (22.5%)	1017	128	11.2%
Large	3536 (69.5%)	3210	326	9.2%
Hospital ownership					NS
Government	393 (7.7%)	355	38	9.7%
Private, not-profit	4215 (82.8%)	3821	394	9.3%
Private, for-profit	482 (9.5%)	426	56	11.6%
Hospital area/teaching status					NS
Metropolitan, non-teaching	824 (16.2%)	753	71	8.6%
Metropolitan, teaching	4104 (80.6%)	3706	398	9.7%
Rural hospital	162 (3.2%)	143	19	11.7%

^aCharlson ME, Pompei PP, Ales KL, et al. A new method of classifying prognostic comorbidity in longitudinal studies: development and validation. J Chronic Dis 1987; 40: 373–383Moore BJ, White S, Washington R, Coenen N, and Elixhauser A. Identifying increased risk of readmission and in-hospital mortality using hospital administrative data: the AHRQ Elixhauser comorbidity index. Med Care 2017; 55(7): 698–705.

^bOther discharge: Short-term facility, Skilled Nurse Facility, Intermediate Care Facility, and against medical advice.

^cAge, CCI, ECI, LOS represented as Median (Interquartile Range).

NS: Not significant (P > 0.05).

Comparing the 30-day readmitted group to the non-readmitted group

Female patients had higher readmission rate compared to males (F = 11.1% vs M = 9.0%, P < 0.001). Readmitted patients were distinguished by several characteristics. They were on Medicare (73.7%, P < 0.001), higher cost of surgery admission ($146,844, P < 0.001), longer stay (8 days, P < 0.001), and were discharged to a lower level care facility (62.7%, P < 0.001). Interestingly, the RA and non-RA groups were similar in age, household income, type of admission, and hospital characteristics. These factors did not reach a statistical significance (P > 0.05) (Table 1).

Comorbidities and reasons for readmission

The most common comorbidities of the RA group include: hypertension (83.8%, P > 0.05), chronic pulmonary disease (44.9%, P < 0.001), coronary artery disease (43.6%, P < 0.05). The complete list of comorbidities is shown in (Table 2). Readmission group had more comorbidities (median ECI = 12, P < 0.001). Patients who scored higher (>5) on the comorbidity index were readmitted more often than those with a lower score (P < 0.001) (Table 2).

Table 2.

Comorbidities of patients admitted for open repair of abdominal aortic aneurysm.

Comorbidities	Non-RA	%	RA	%	OR	CI95 L	CI95U	P value
Hypertension	3764	81.8%	409	83.8%				NS
Chronic pulmonary disease	1623	35.3%	219	44.9%	1.49	1.24	1.80	<0.001
Coronary artery disease	1755	38.1%	213	43.6%	1.26	1.04	1.52	<0.05
Diabetes	784	17.0%	96	19.7%				NS
Anemia	429	9.3%	66	13.5%	1.52	1.15	2.01	<0.01
Atrial fibrillation	387	8.4%	60	12.3%	1.53	1.14	2.04	<0.01
Asthma	140	3.0%	27	5.5%	1.87	1.22	2.85	<0.01
Chronic heart failure	99	2.2%	18	3.7%	1.74	1.04	2.90	<0.05
Peripheral arterial disease	76	1.7%	17	3.5%	2.15	1.26	3.67	<0.01
Complications
Acute post-hemorrhagic anemia	1726	37.5%	208	42.6%	1.24	1.02	1.50	<0.05
Acute renal failure	883	19.2%	120	24.6%	1.37	1.10	1.71	<0.01

NS: Not significant (P > 0.05).

The most common diagnoses and procedures at readmission are listed in (Table 3). On readmission visit, acute renal failure (23.8%) was the most common diagnosis, while intestinal surgery (13.7%) was the most common procedure. Notably, 20 patients (4.1%) of the RA underwent a redo AAA repair, mainly for thrombosis/embolism or graft leakage.

Table 3.

Most common diagnoses/procedures on readmission visit.

Diagnosis and procedures	(n = 488)	%
Kidney and urinary tract
Acute renal failure	116	23.8%
Digestive system
Stomach/Small intestine surgery	47	9.6%
Large intestine surgery	20	4.1%
Circulatory system
Redo AAA repair	20	4.1%
Infra-inguinal (bypass/endarterectomy/aneurysm)	11	2.3%
Cardiac surgery (CABG/PCI/Valve)	6	1.2%
Amputation	6	1.2%
Respiratory system
Pulmonary embolism/Acute respiratory failure	58	11.9%
Pneumonia	52	10.7%
COPD exacerbation	37	7.6%
Infectious diseases
Post-op infection	57	11.7%
Sepsis	56	11.5%

Mortality and readmission rates throughout the years

In-hospital mortality rate during surgery admission was (n = 293, 6.4%). while during readmission was (n = 23, 4.7%). Readmission rates remained steady through the targeted timeframe with slight increase in 2018. The median (range) number of days from discharge to readmission was 9 (4–17) days (Figure 2).

Figure 2.

Days to readmission for patients with 25th, 50th, and 75th percentile.

Univariate analysis of risk factors for readmission

Certain comorbidities predisposed patients for readmission including peripheral arterial disease (OR 2.15, P < 0.01), asthma (OR 1.87, P < 0.01), chronic heart failure (OR 1.74, P < 0.05), atrial fibrillation (OR 1.53, P < 0.01), anemia (OR 1.52, P < .01), chronic pulmonary disease (OR 1.49, P < 0.001), and coronary artery disease (OR 1.26, P < 0.05). Furthermore, having certain complications such as acute renal failure (OR 1.37, P < 0.01), and acute post-hemorrhagic anemia (OR 1.24, P < 0.05) increased the likelihood of readmission (Table 2).

Chronic kidney disease and open aneurysm repair

Patients with CKD and OAR were identified (n = 968, 18.9% of total population). This cohort had in-hospital mortality rate of (n = 100, 10.4%) during the first admission and (n = 97, 10.1%) during readmission.

Patients with CKD were divided into three groups based on their CKD status (Table 4). CKD Stage 1–2 (n = 73, 7.6%), had 30-days readmission rate of (8.2%), and in-hospital mortality rate of (12.3%). CKD Stage 3–4 were the majority (n = 532, 55.2%) with 30-day readmission rate of (9.4%) and in-hospital mortality rate of (9.4%). CKD Stage 5-ESRD (n = 74, 7.7%) had the highest 30-day readmission rate (16.2%) and in-hospital mortality rate (21.6%). Infection was the most common diagnosis at readmission for patients with CKD stage 1–2 and 5-ESRD, and acute renal failure in patients with CKD stage 3–4.

Table 4.

Chronic Kidney Disease cohort.

	Count	Mortality^a	%	Readmitted	%	Reason for readmission
CKD 1–2	73	9	12.3	6	8.2	Infection
CKD 3–4	532	50	9.4	50	9.4	Acute renal failure
CKD 5-ESRD	74	16	21.6	12	16.2	Infection
CKD unknown	284	25	8.8	29	10.2	Acute renal failure
Total	963	100	10.4	97	10.1	Acute renal failure

^aduring surgery admission.

Discussion

Readmission after OAR totaled to 9.6%. Readmitted patients had more comorbidities, were on Medicare, had a higher surgery admission cost, longer hospital stay, and were discharged to a lower level care facility. Comorbidities that predisposed patients for readmission include: Peripheral arterial disease, asthma, and chronic heart failure. On readmission visit, acute renal failure was the most common diagnosis, while lower intestinal surgery was the most common procedure. Patients with CKD (18.9% of total population) had double the mortality rate compared to non-CKD patients on surgery admission and readmission.

During this study’s timeframe (2016–2018), only 11.3% of AAA repairs were done by open approach, which reflects the current trend favoring EVAR for AAA repair. This study 30-days readmission rate is lower than the previous years.^23,24 Aridi et al. performed a retrospective analysis of the Premier Healthcare Database from 2009 to 2015 and found a rate of (12.9%).²³ Casey et al. used the State Inpatient Database (SID) in California from 2003 to 2008 and found a rate of (20.0%).²⁴ This suggests that 30-days readmission rates after OAR have been on the decline for the past 20 years. This can be credited to the progress in post-operative patient care and advancement in surgical technologies.

Although females only constituted a quarter (28.0%) of the total OAR population, they had a higher readmission rate compared to males. This is not an uncommon result since previous literature had reported higher readmission rates and odds for female patients.²² Females have been reported to be statistically protected from the development of AAA,^23–25 but if they do, they suffer more complications that lead to their readmission. Underlying pathophysiology behind that is not well understood. However, differences between males and females including hormonal influences, vessels anatomy and others could have some contribution to this.²⁶ Furthermore, a sub-analysis of the database revealed that female patients presented to the surgery with more comorbidities compared to men. This could also be the reason behind the higher readmission rate.

Patients who were on Medicare, as their primary payer, had a higher readmission rate compared to the rest of the population. Meanwhile, patients who had private insurance had a noticeably lower rate. Perlstein et al. reported that patients on Medicare and Medicaid have a higher readmission rate compared to patients on private insurance.²⁷ This can be a consequence of the difficulties older Medicare patients face on a regular basis compared to others who have a premium private insurance regarding treatment options, risk factors modifications, optimization of comorbid conditions, and insurance coverage. Another point worth to highlight and investigate is the after-hospital placement and its impact on readmission rate. As private insurance patients may have different access to this service compared to Medicare patients.

Readmitted patients stayed longer at the hospital during surgery admission. Bath et al. conducted a retrospective cohort study (2009–2016) of 30-days readmission after elective AAA repair. They reported that readmitted patients have also longer stay.²⁸ Multiple studies have reported a similar finding.^24,29,30 Additionally, the RA had a higher cost of surgery admission. The Medicare Payment Advisory Commission (MedPAC), tasked with reporting the number of avoidable hospital readmissions, found that vascular surgery readmissions have costed the Medicare program $182,000,000 in 2005.³¹ Vascular pathology among six other conditions (i.e. heart failure, chronic obstructive pulmonary disease, pneumonia, coronary artery bypass graft, acute myocardial infarction, and percutaneous transluminal coronary angioplasty), defined by MedPAC, make up almost 30% of spending on readmissions nationally. Medicare spending on these potentially preventable readmissions is substantial; $12 billion for cases readmitted within 30 days.³¹ This creates the need to implement initiatives to prevent and reduce readmission post-operatively.

Patients discharged to a lower level care facility after their surgery were likely to be readmitted than those who had a routine discharge to their homes. Current literature considers non-routine discharge (i.e. lower level care facility) to be a significant risk factor for readmission.^19,23,29 Greenblatt et al. reported that patients who were not discharged routinely to their homes were more likely to be readmitted, especially those who were transferred to a skilled nursing facility (SNF) or had home health care.¹⁹ Patients who do not receive the option to be routinely discharged usually belong to a high-risk population that need continuous medical attention post-discharge, which might explain the higher readmission rate. Additionally, they had significantly higher surgery visit cost than those discharged directly to home. This does reflect complexity and significant comorbidities of this group of patients needed the nursing home stay after discharge. However, it is very important to put into consideration the liberal and unnecessary usage of SNF at discharge can put a large financial burden on the healthcare system.

Readmitted patients had more comorbidities. Therefore, comorbidities that affect the risk of readmission were analyzed. Peripheral arterial disease appears to have the strongest influence on the risk of 30-day readmission, followed by other comorbidities such as asthma, chronic heart failure, atrial fibrillation, anemia, chronic pulmonary disease, and coronary artery disease. Aridi et al. reported similar patients’ comorbidities as risk factors of 30-days readmission after AAA repair.²³ Another study reported that diabetes, chronic lung disease, and renal failure are associated with readmission.³² It is always of significant importance to optimize modifiable risk factors before proceeding with surgery to improve outcome.

Post-operative complications such as acute renal failure, and acute post-hemorrhagic anemia increased the likelihood of readmission. Certain in-hospital complications, such as bleeding and renal complications, influence readmissions.²³ Screening these patients more carefully before discharge might help in combating readmissions.²³ Martinez et al. reported the same finding that renal failure was one of the common diagnoses at readmission.²⁹ Importantly, intestinal surgery was very common among readmitted patients. Majority of these cases involved small or large bowel resection. Various gastrointestinal complications following aneurysm repair has been reported in the literature.^33–36 Large bowel ischemia at the watershed area is a known complication after AAA repair specially after excluding the blood flow to the inferior mesenteric artery (IMA). That is why it is important to obtain good surgical history, images review and consider IMA reimplantation in high-risk patients. Small bowel ischemia on the other hand can develop from atheromatous emboli or superior mesenteric artery (SMA) dissection/injury during the AAA repair. Careful handling of the SMA and small bowel evaluation at completion are crucial. Patients with greater cardiovascular comorbidity may have more atherosclerotic disease in all vascular bed including the mesenteric vessels, which increases the risk of SMA dissection/injury during the procedure or more commonly colonic ischemia from disconnecting the IMA in the setting of a diseased SMA. Preoperative planning, paying extra attention intraoperatively and meticulous perioperative fluid management in this group of patients could have a beneficial effect.

The incidence of peptic ulcer disease (PUD) directly related to AAA repair is rare to begin with (0.9%) and its incidence has been further reduced by the routine incorporation of proton pump inhibitors (PPI’s) into the management protocols of patients following AAA surgery.³⁷ In this study, 18 of the readmitted patients after OAR were diagnosed with complicated peptic ulcer requiring surgical intervention. Hypothesis behind PUD following OAR include: a decrease in gastric mucosal blood flow, the consumptive coagulopathy that can occur due to blood loss and the systemic inflammatory response that results from AAA.³⁸ This is more prominent following ruptured OAR or in patients with comorbidities.

Patients with CKD had double the mortality rate on surgery admission and readmission compared to non-CKD patients. Considering the annual risk of aortic aneurysm rupture is approximately 9.4% for AAA of 5.5–5.9 cm, 10.2% for AAA of 6.0–6.9 cm (19.1% for the subgroup of 6.5–6.9 cm), and 32.5% for AAA of 7.0 cm or more,³⁹ this finding urges vascular surgeons to further optimize patients with CKD before considering OAR for those who are not candidate for EVAR. Patients with CKD Stage 5-ESRD had the highest mortality rate (21.6%) in this study, which provide an important information to consider when counseling this group of patients for OAR.

This study was designed and analyzed within the scope of the general population. It has a large sample size with comprehensive analysis that shows novel contemporary results that focus more directly on the relationship between patients’ characteristics and factors toward readmissions after OAR. Previous studies have examined readmission rates, but they suffer from small patient populations, geographically constrained databases, or short study timeframes. Our large-scale study aims to add to the current literature by including national-level data over a 3-year period. Utilizing the NRD has its strengths and weaknesses. One of its strengths as compared to a single facility study design is the capacity to capture patients readmitting to a different hospital than their index admission. Though the NRD is not a perfect system to incorporate every readmission, it allows for more of these patients to be accounted for among the readmitted population. The limitations of our study include its retrospective nature, the use of an administrative database with a potential reporting bias, and a lack of long-term outcomes. Also, excluding data from the December month due to database limitation might create some bias, potentially for patients presenting during the holiday season.

Conclusion

The 30-day readmission rate after OAR during this study timeframe is lower than the previous years. Readmissions were higher in those who have multiple comorbidities, female patients, on Medicare insurance, and those discharged to a lower level care facility, or had a long hospital stay. Specific comorbidities such as peripheral arterial disease had the strongest influence on the risk of 30-day readmission, followed by asthma and heart failure. Readmission rates remained steady throughout the study timeframe, with slight increase in 2018. Patients with CKD who underwent OAR had double the mortality rate compared to non-CKD patients on surgery admission and readmission. Bearing in mind the risk of aortic aneurysm rupture, vascular surgeons should further optimize patients with CKD before considering OAR especially in those with CKD Stage 5-ESRD.

Supplemental Material

Supplemental Material - Risk factors for readmission after open abdominal aortic aneurysms repair and its outcome in chronic kidney disease patients

Supplemental Material for Risk factors for readmission after open abdominal aortic aneurysms repair and its outcome in chronic kidney disease patients by Abdullah Nasif, Gang Ren, Amin Mohamed Ahmed, Ali Mahmoud, Munier Nazzal, Mohamed Osman and Ayman Ahmed in Vascular

Footnotes

Declaration of conflicting interests

The author(s) declared no potential conflicts of interest with respect to the research, authorship, and/or publication of this article.

Funding

The author(s) received no financial support for the research, authorship, and/or publication of this article.

ORCID iD

Abdullah Nasif

Supplemental Material

Supplemental material for this article is available online.

References

Ashton

Buxton

Day

, et al. The Multicentre Aneurysm Screening Study (MASS) into the effect of abdominal aortic aneurysm screening on mortality in men: a randomised controlled trial. Lancet 2002; 360(9345): 1531–1539.

Derubertis

Trocciola

Ryer

, et al. Abdominal aortic aneurysm in women: prevalence, risk factors, and implications for screening. J Vasc Surg 2007; 46(4): 630–635.

Mortality results for randomised controlled trial of early elective surgery or ultrasonographic surveillance for small abdominal aortic aneurysms. The UK Small Aneurysm Trial Participants. Lancet 1998; 352(9141): 1649–1655.

Parodi

Palmaz

Barone

. Transfemoral intraluminal graft implantation for abdominal aortic aneurysms. Ann Vasc Surg 1991; 5(6): 491–499.

Suckow

Goodney

Columbo

, et al. National trends in open surgical, endovascular, and branched-fenestrated endovascular aortic aneurysm repair in Medicare patients. J Vasc Surg 2018; 67(6): 1690–1697.e1.

Salata

Hussain

de Mestral

, et al. Trends in elective and ruptured abdominal aortic aneurysm repair by practice setting in Ontario, Canada, from 2003 to 2016: a population-based time-series analysis. CMAJ Open 2019; 7(2): E379–E384.

Schermerhorn

Buck

O'Malley

, et al. Long-term outcomes of abdominal aortic aneurysm in the medicare population. N Engl J Med 2015; 373(4): 328–338.

United Kingdom EVAR Trial Investigators Greenhalgh

Brown

Powell

, et al. Endovascular versus open repair of abdominal aortic aneurysm. N Engl J Med 2010; 362(20): 1863–1871.

De Bruin

Baas

Buth

, et al. Long-term outcome of open or endovascular repair of abdominal aortic aneurysm. N Engl J Med 2010; 362(20): 1881–1889.

10.

Lederle

Freischlag

Kyriakides

, et al. Long-term comparison of endovascular and open repair of abdominal aortic aneurysm. N Engl J Med 2012; 367(21): 1988–1997.

11.

van Schaik

Yeung

Verhagen

, et al. Long-term survival and secondary procedures after open or endovascular repair of abdominal aortic aneurysms. J Vasc Surg 2017; 66(5): 1379–1389.

12.

Patel

Sweeting

Powell

, et al. Endovascular versus open repair of abdominal aortic aneurysm in 15-years' follow-up of the UK endovascular aneurysm repair trial 1 (EVAR trial 1): a randomised controlled trial. Lancet 2016; 388(10058): 2366–2374.

13.

Turney

Steenberge

Lyden

, et al. Late graft explants in endovascular aneurysm repair. J Vasc Surg 2014; 59(4): 886–893.

14.

Kouvelos

Koutsoumpelis

Lazaris

, et al. Late open conversion after endovascular abdominal aortic aneurysm repair. J Vasc Surg 2015; 61(5): 1350–1356.

15.

Zerwes

Kiessling

Liebetrau

, et al. Open conversion after endovascular aneurysm sealing: technical features and clinical outcomes in 44 patients. J Endovasc Ther 2021; 28(2): 332–341.

16.

Tang

Chen

Huang

, et al. The incidence, risk factors and in-hospital mortality of acute kidney injury in patients after abdominal aortic aneurysm repair surgery. BMC Nephrol 2017; 18(1): 184.

17.

Mills

Sr Duong

Leon

Jr , et al. Comparison of the effects of open and endovascular aortic aneurysm repair on long-term renal function using chronic kidney disease staging based on glomerular filtration rate. J Vasc Surg 2008; 47(6): 1141–1149.

18.

Saratzis

Bath

Harrison

, et al. Long-term renal function after endovascular aneurysm repair. Clin J Am Soc Nephrol 2015; 10(11): 1930–1936.

19.

Greenblatt

Greenberg

Kind

, et al. Causes and implications of readmission after abdominal aortic aneurysm repair. Ann Surg 2012; 256(4): 595–605.

20.

Overview of the Nationwide Readmissions Database (NRD), https://www.hcup-us.ahrq.gov/nrdoverview.jsp#about (2022, accessed January 19 2022).

21.

Charlson

Pompei

Ales

, et al. A new method of classifying prognostic comorbidity in longitudinal studies: development and validation. J Chronic Dis 1987; 40: 373–383.

22.

Moore

White

Washington

, et al. Identifying increased risk of readmission and in-hospital mortality using hospital administrative data: the AHRQ Elixhauser comorbidity index. Med Care 2017; 55(7): 698–705.

23.

Dakour Aridi

Locham

Nejim

, et al. Indications, risk factors, and outcomes of 30-day readmission after infrarenal abdominal aneurysm repair. J Vasc Surg 2018; 67(3): 747–758.e7.

24.

Casey

Hernandez-Boussard

Mell

, et al. Differences in readmissions after open repair versus endovascular aneurysm repair. J Vasc Surg 2013; 57(1): 89–95.

25.

Hannawa

Eliason

Upchurch

Jr . Gender differences in abdominal aortic aneurysms. Vascular 2009; 17(Suppl 1): S30–S39.

26.

Joh

Ahn

Park

. Reference diameters of the abdominal aorta and iliac arteries in the Korean population. Yonsei Med J 2013; 54(1): 48–54.

27.

Perlstein

Gupta

, et al. Abdominal aortic aneurysm repair readmissions and disparities of socioeconomic status: a multistate analysis, 2007-2014. J Cardiothorac Vasc Anesth 2019; 33(10): 2737–2745.

28.

Bath

Smith

Kruse

, et al. Cohort study of risk factors for 30-day readmission after abdominal aortic aneurysm repair. Vasa 2019; 48(3): 251–261.

29.

Martinez

Gaffney

Parreco

, et al. Nationally representative readmission factors associated with endovascular versus open repair of abdominal aortic aneurysm. Ann Vasc Surg 2018; 53: 105–116.

30.

Gupta

Fernandes-Taylor

Ramanan

, et al. Unplanned readmissions after vascular surgery. J Vasc Surg 2014; 59(2): 473–482.

31.

Hackbarth

Reischauer

Miller

. Report to the Congress: Promoting Greater Efficiency in Medicare. Washington DC: Medicare Payment Advisory Commission. https://www.ruralhealthinfo.org/assets/4544-19961/Jun07_EntireReport.pdf (2007).

32.

Bath

Dombrovskiy

Vogel

. Impact of Patient Safety Indicators on readmission after abdominal aortic surgery. J Vasc Nurs 2018; 36(4): 189–195. Epub 2018 Oct 2. PMID: 30458941; PMCID: PMC6857707.

33.

Malinzak

Long

Bove

, et al. Gastrointestinal complications following infrarenal endovascular aneurysm repair. Vasc Endovascular Surg 2004; 38(2): 137–142.

34.

Bernatz

. Necrosis of the colon following resection for abdominal aortic aneurysms. Arch Surg 1960; 81(3): 373–378.

35.

DeWeese

Fry

. Small-bowel erosion following aortic resection. JAMA 1962; 179(11): 882–886.

36.

Zhang

Kulaylat

Anain

, et al. Embolization as cause of bowel ischemia after endovascular abdominal aortic aneurysm repair. J Vasc Surg 2004; 40(5): 867–872. PMID: 15557898.

37.

Achouh

Madsen

Miller

3rd , et al. Gastrointestinal complications after descending thoracic and thoracoabdominal aortic repairs: a 14-year experience. J Vasc Surg 2006; 44(3): 442–446.

38.

Konno

Sakaguchi

Hachiya

. Bleeding peptic ulcer after abdominal aortic aneurysm surgery. Arch Surg 1991; 126(7): 894–897.

39.

Lederle

Johnson

Wilson

, et al. Rupture rate of large abdominal aortic aneurysms in patients refusing or unfit for elective repair. JAMA 2002; 287(22): 2968–2972.

Supplementary Material

Please find the following supplemental material available below.

For Open Access articles published under a Creative Commons License, all supplemental material carries the same license as the article it is associated with.

For non-Open Access articles published, all supplemental material carries a non-exclusive license, and permission requests for re-use of supplemental material or any part of supplemental material shall be sent directly to the copyright owner as specified in the copyright notice associated with the article.

0.00 MB

0.22 MB