Prospective Randomized Trial of Routine versus Selective Shunting in Carotid Endarterectomy Based on Stump Pressure

BACKGROUND:
The use of shunting in carotid endarterectomy (CEA) is controversial. Only a few randomized trials have compared routine versus selective shunting, however none were based on stump pressure (SP). This is the first randomized trial to compare the results of routine (RS) versus selective shunting (SS) based on SP.
METHODS:
200 CEA patients under general anesthesia were randomized into RS (n=98) and SS (n=102) where shunting was used only if systolic SP was <40 mmHg (SSP). All patients had immediate and 30-day postoperative duplex ultrasound follow-up. Analysis was done based on intention to treat.
RESULTS:
Shunting was used in 29/102 (28%) SS patients. Clinical/demographic characteristics were comparable in both groups. Indications for CEA were also similar (42% symptomatic for RS versus 47% for SS, p=0.458). The mean internal carotid artery diameter was also comparable (5.5 versus 5.5, p=0.685). The mean preoperative ipsilateral and contralateral stenosis was 76% and 38% for RS versus 78% and 40% for SS (p=0.268 and 0.528, respectively). The mean preoperative ipsilateral and contralateral stenosis were 79% and 56% in the shunted versus 78% and 34% in the non-shunted subgroup of SS patients (p=0.634 and 0.002, respectively). The mean SSP was 55.9 in RS versus 56.2 mmHg for SS (p=0.915). The mean SSP in the shunted versus non-shunted subgroup of SS was 33 versus 65 mmHg (p<0.0001). Mean clamp time in the non-shunted subgroup of SS was 32 minutes. Mean shunt time was 35 minutes in RS versus 33 minutes in SS (p=0.354). Mean operative time was 113 minutes for RS and 109 for SS (p=0.252), while it was 111 minutes in shunted and 108 in the non-shunted subgroup (p=0.586). Mean arteriotomy length was 4.4 for RS and 4.2 cm for SS (p=0.213). Perioperative stroke rate was 0% for RS versus 2% for SS (one major and one minor stroke - neither were shunted, p=0.498). There were no perioperative deaths. The combined perioperative transient ischemic attack and stroke rates were 2% in RS versus 2.9% in SS (p=1). The overall perioperative complication rates were 8.3% in RS ( 2 TIA, 3 bleed, and 1 myocardial infarction, and 1 asymptomatic carotid thrombosis) versus 7.8% in SS (2 strokes, 1 TIA, 3 bleed, 1 MI, and 1 congestive heart failure) (p=0.917).
CONCLUSIONS:
Perioperative stroke/overall complication rates were somewhat similar for RS and SS based on SSP of <40 mmHg.