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Published on: June 8, 2019
Patency and limb salvage after infrainguinal bypass with severely compromised ("blind") outflow
T R Desai1, S L Meyerson, C L Skelly
1University of Chicago, MC 5028, 5841 S Maryland Ave, Chicago, IL 60637, USA. tdesai@surgery.bsd.uchicago.edu
Insights
Infrainguinal bypass grafts with "blind outflow" had similar patency rates to those with patent outflow. However, blind outflow was associated with worse limb salvage outcomes in patients undergoing bypass surgery.
Area of Science:
- Vascular Surgery
- Reconstructive Surgery
Background:
- Severely compromised outflow negatively impacts infrainguinal graft patency and limb salvage.
- Effective surgical strategies are crucial for improving outcomes in patients with critical limb ischemia.
Purpose of the Study:
- To evaluate the outcomes of infrainguinal bypass grafts with "blind outflow" compared to those with at least one patent outflow vessel.
- To determine if "blind outflow" affects graft patency and limb salvage rates.
Main Methods:
- Retrospective review of 351 infrainguinal bypass procedures in 274 patients over 5 years at a university teaching hospital.
- Grafts were categorized into those with at least one patent outflow vessel (n=279) and "blind bypass" grafts with only collateral outflow (n=72).
- Outcomes assessed included perioperative morbidity/mortality, graft patency, limb salvage, and survival.
Main Results:
- Patients undergoing "blind bypass" were older and had more comorbidities (hypertension, end-stage renal disease).
- No significant difference was found in 2-year secondary graft patency between "blind bypass" (67%) and patent outflow grafts (64%).
- However, 2-year limb salvage rates were significantly lower for "blind bypass" (67%) compared to patent outflow grafts (76%).
Conclusions:
- Infrainguinal bypass grafts with "blind outflow" can achieve acceptable long-term patency rates.
- "Blind outflow" serves as a significant predictor of subsequent limb loss in patients with chronic limb ischemia.
- Careful patient selection and surgical planning are essential when considering bypass for "blind outflow" scenarios.
Hypothesis:
Infrainguinal graft patency and limb salvage are adversely affected by severely compromised outflow.
Design:
Retrospective review of all infrainguinal bypass procedures performed at a single institution during a 5-year period.
Setting:
University teaching hospital.
Patients:
Two hundred seventy-four patients underwent infrainguinal bypass for limb salvage (351 grafts in 307 limbs).
Interventions:
All infrainguinal bypasses originated from a femoral artery. The distal anastomosis in 279 grafts was located in an artery with at least 1 patent outflow vessel with anatomically normal end-artery runoff (Society for Vascular Surgery/International Society for Cardiovascular Surgery ad hoc committee runoff score, 1-9). The distal anastomosis of 72 grafts was located in an artery with only collateral outflow ("blind bypass"; runoff score, 10).
Main Outcome Measures:
Perioperative morbidity and mortality, primary-assisted and secondary graft patency, limb salvage, and survival.
Results:
All data are presented as mean +/- SEM. Patients undergoing blind bypass were older (age, 70 +/- 2 vs. 66 +/- 1 years; P <.05) and had a higher incidence of hypertension (90% vs 70%; P <.05) and end-stage renal disease (24% vs. 13%; P <.05). Comparing patients undergoing blind bypass to bypass with at least 1 patent outflow vessel, there were no differences in the use of nonautogenous conduits (50% vs 59%; P =.21) or postoperative warfarin (30% vs 32%; P =.69), or in perioperative mortality rates (2.7% vs 3.2%; P =.79). After a median follow-up of 13 months (range, 0-60 months), 2-year secondary graft patency for the entire group was 63% +/- 4%. The secondary patency rate of blind bypass grafts was no different from that of grafts with at least 1 patent outflow vessel (67% +/- 7% vs. 64% +/- 4%; P was not significant). However, the 2-year limb salvage rate in limbs with blind outflow was significantly worse than in limbs with at least 1 patent outflow vessel (67% +/- 7% vs. 76% +/- 3%; P =.04).
Conclusion:
Acceptable long-term patency rates can be achieved in infrainguinal bypass grafts with blind outflow, although blind outflow remains a marker for subsequent limb loss in the chronically ischemic leg.
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