SS16. 30 Day Mortality From Reintervention or Readmission Following Endovascular and Open Repair of Abdominal Aortic Aneurysms in the United States Medicare Population
Late survival is similar after EVAR and open AAA repair (OAR) despite a perioperative benefit with EVAR. AAA-related reinterventions are more common after EVAR while laparotomy related reinterventions are more common after OAR. The impact of reinterventions on survival, however, is unknown.
Methods
Using propensity score matched Medicare beneficiaries (n=45,652) undergoing EVAR and OAR from 2001-2004, AAA and laparotomy-related reinterventions through 2006 were identified. A hierarchical severity scheme was utilized within each hospitalization to avoid counting multiple adjunctive procedures. Hospitalizations for ruptured AAA without repair and for bowel obstruction or ventral hernia without abdominal surgery as well as amputations were also recorded. 30 day mortality was calculated for each reintervention or readmission.
Results
Overall reinterventions or readmissions were similar between repair methods but slightly more common after EVAR (Table). EVAR patients had more ruptures (mortality 27%). EVAR patients also had more AAA-related reinterventions (mortality 5.6%), the majority of which were minor endovascular reinterventions (mortality 3.0%). However, minor open (mortality 6.9%) and major reinterventions (mortality 12.1 %) were also more common after EVAR than open repair. OAR patients had more laparotomy related reinterventions (mortality 8.1%) and readmissions without surgery (mortality 10.9%). Overall 30 day mortality after any reintervention or readmission was higher after EVAR than OAR (9.8% vs 7.5%, p<0.001).
Follow-up year
Annual reinterventions or readmissions per patient-year
30 day mortality
Year 1
Year 2
Year 3
Year 4
Year 5
Year 6
Overall
Endo /open
Endo /open
Endo /open
Endo /open
Endo /open
Endo /open
Endo /open
All Reinterventions or Readmissions
7.6%/8.2%
6.2%/6.3%
5.8%/4.5%
4.6%/4.3%
4.4%/4.3%
3.1%/2.4%
5.9%/5.7%
8.6%
- Rupture Readmission
0.2%/0.1%
0.4%/0.1%
0.5%/0.1%
0.5%/0.0%
0.5%/0.1%
0.4%/0.0%
0.4%/0.1%
26.8%
- AAA-related Reintervention
4.0%/1.2%
2.8%/0.7%
3.0%/0.6%
2.2%/0.8%
2.2%/0.5%
1.6%/0.3%
3.0%/0.8%
5.6%
- Rupture Repair
0.0%/0.0%
0.1%/0.0%
0.2%/0.0%
0.1%/0.0%
0.2%/0.0%
0.2%/0.0%
0.1%/0.0%
30.2%
- Major Reintervention
0.5%/0.3%
0.4%/0.1%
0.4%/0.1%
0.3%/0.2%
0.3%/0.1%
0.2%/0.0%
0.4%/0.1%
12.1%
- Minor Reintervention
3.8%/1.0%
2.5%/0.6%
2.5%/0.5%
1.9%/0.7%
2.0%/0.4%
1.4%/0.3%
2.7%/0.7%
4.4%
- Open
1.4%/0.8%
0.5%/0.4%
0.4%/0.3%
0.5%/0.5%
0.3%/0.2%
0.3%/0.2%
0.7%/0.5%
6.9%
- Endovascular
2.4%/0.2%
2.0%/0.2%
2.1%/0.2%
1.5%/0.2%
1.6%/0.2%
1.0%/0.1%
2.0%/0.2%
3.0%
- Laparotomy-Related Reinterventions
1.8%/4.0%
1.3%/3.6%
1.2%/2.0%
1.0%/1.8%
0.8%/1.9%
0.4%/1.0%
1.3%/2.8%
8.1%
- Readmission for Bowel Obstruction or Ventral Hernia without Surgery
2.3%/3.8%
2.3%/2.6%
1.9%/2.4%
1.6%/2.4%
1.6%/2.7%
1.0%/1.4%
2.0%/2.8%
10.9%
- Amputation
0.2%/0.4%
0.2%/0.2%
0.1%/0.1%
0.1%/0.1%
0.1%/0.1%
0.1%/0.0%
0.2%/0.2%
7.2%
Conclusion
Overall reintervention and readmission, and their associated 30 day mortality, are higher after EVAR with up to 6 years of follow-up which likely contributes to loss of late survival benefit after EVAR.