Patients who underwent lower extremity amputations secondary to diabetes or peripheral vascular disease often have medical comorbidities and a high perioperative mortality rate. 1
The effect of anesthesia type on postoperative mortality has been studied in various types of surgery. 2
However, there is little data to guide the clinicians with selecting the most appropriate anesthetic method for lower extremity amputations. 3,4
After obtaining approval from the institutional review board (IRB protocol no. 4-2017-0979), we reviewed the medical records of patients who underwent lower extremity amputation at a single center between September 2012 and August 2017.
The study population was divided into two groups according to the type of anesthesia used: General anesthesia (GA) or regional anesthesia (RA; spinal anesthesia or peripheral nerve block).
Primary outcomes were 30- and 90-day mortalities.
Secondary outcomes were postoperative morbidities, including myocardial infarction, cardiac arrest, pneumonia, sepsis, renal failure, stroke, and wound complications.
Additionally, intraoperative events (hypotension, vasopressor usage, transfusion, and hypoxia), postoperative intensive care unit (ICU) admission, and the postoperative hospital stay duration were also included as secondary outcomes.
We identified 292 patients, 142 of which underwent amputation under GA and 150 under RA.
When comparing patients based on demographics and comorbidities, patients undergoing GA were more likely to be administered anticoagulation therapy (aspirin, 64% vs. 52%, p=0.036; clopidogrel, 66% vs. 44%, p<0.001); further, they also received more interventional management for peripheral arterial occlusive disease less than 1 year before amputation (58.9% vs.42%, p=0.004).
Compared to the RA group, the GA group had longer operative time (72.6 ± 48.9 vs. 57.4 ± 38.7, p=0.001) and anesthetic time (117.1 ± 56.4 vs. 93.2 ± 45.2, p=0.001). Moreover, major amputations, such as above- and below-knee amputations, were performed more in the GA group than in the RA group (29.6% vs. 13.3%, p=0.001). Additionally, compared with the GA group, the RA group was also associated with lower incidences of intraoperative hypotension (60.6% vs. 15.3%, p<0.001), vasopressor usage (55.6% vs.14%, p<0.001), and transfusion (17.6% vs. 8%, p=0.014). (Table 1)
There was no significant difference with respect to the 30-day (2.82% vs. 2.67%, p>0.999) and 90-day (2.11% vs. 1.33%, p=0.6771) mortalities and postoperative morbidities. However, postoperative ICU admission rates (20.4% vs.8%, p=0.002) and postoperative length of hospital stay (14.17 ± 17.31 vs.11.33 ± 12.8, p=0.017) were lower in the RA group than in the GA group. (Table 2)
The type of anesthesia did not significantly affect postoperative mortality and morbidity after lower extremity amputation.
However, intraoperative hypotension, vasopressor usage, transfusion, postoperative ICU admission rates, and postoperative length of hospital stay were lower in the RA group than in the GA group.
1.Stern JR, Wong CK, Yerovinkina M, Spindler SJ, See AS, Panjaki S, Loven SL, D’Andrea RF Jr, Nowygrod R. A meta-analysis of long-term mortality and associated risk factors following lower extremity amputation. Ann Vasc Surg, 2017. 42: 322-327.
2.Perlas A, Chan VWS, Beattie S. Anesthesia technique and mortality after total hip or knee arthroplasty : a retrospective, propensity score-matched cohort study. Anesthesiology, 2016. 125: 724-31.
3.Chery J, Semaan E, Darji S, Briggs WT, Yarmush J, D’Ayala M. Impact of regional versus general anesthesia on the clinical outcomes of patients undergoing major lower extremity amputation. Ann Vasc Surg, 2014. 28: 1149-56.
4.Moreira CC, Farber A, Kalish JA, Eslami MH, Didato S, Rybin D, Doros G, Siracuse JJ. The effect of anesthesia type on major lower extremity amputation in functionally impaired elderly patients. J Vasc Surg, 2016. 63: 696-701.