6 0 rounded tip nylon suture

Focal cerebral ischemia was induced in male KLF11 knockout mice (kindly provided by Dr. Eugene Chen [16 (link)]) and wild-type mice on C57BL/6J background (8–10w, 23–25g) by intraluminal middle cerebral artery occlusion (MCAO) as described previously [22 (link),23 (link),13 (link)]. Briefly, mice were anesthetized with 1.5–3% isoflurane (Henry Schein Animal Health). A 2-cm length of a 6–0 rounded tip nylon suture (Doccol Corporation, Sharon, MA) was gently advanced from the internal carotid artery up to the origin of the middle cerebral artery (MCA) until regional cerebral blood flow (CBF) was reduced to less than 25% of baseline. After 1h of MCA occlusion, blood flow was restored by removing the suture, and the mice were allowed to recover for 1–7 days. In sham-operated mice, the same surgical procedure was performed but no suture insertion. Changes in CBF, mean arterial pressure, and heart rate were monitored in animals 15 min before, during, and after MCAO. Animals that did not show a CBF reduction of at least 75% over baseline levels were excluded from further experimentation. Approximate 90% survival rate was observed in KLF11 knockout or wild-type mice at 1–7 d after MCAO. Animals that died after ischemia induction were also excluded. The rectal temperature was controlled at 37.0 ± 0.5°C during surgery.

The MCAO model was established using filament insertion as reported previously.(4 (link)) Mice were anesthetized with ketamine, xylazine and acepromazine. After local infiltration with bupivacaine, the right common carotid artery was isolated and its branches were electrocoagulated. The proximal middle cerebral artery was occluded for 120 minutes by a 6-0 rounded tip nylon suture with length of 2-cm (Doccol corporation, Sharon, MA, USA) and blood flow was restored by removing the suture. During the procedure, the animals were placed over a feedback-controlled heating pad (Model TC-1000 Temperature Controller, CWE Inc.) to maintain the body temperature. After the surgery, mice were allowed to recover for 24 hours with adequate post-operative analgesia with meloxicam (5 mg/kg). In sham control animals, the carotid arteries were exposed without occlusion of the middle cerebral artery.