Wrong preoperative marking on the scalp vein complicating the cutdown of the cerebrovascular bypass: Two case reports

Background: The cutdown procedure in cerebrovascular bypass requires incising the scalp along the preoperative marking identifying the arteries. We present two patients in whom preoperative marking on the scalp misidentified veins as arteries and thus complicated the surgical procedure. Case description: A 46-year-old male with Moyamoya disease (Case 1) and a 73-year-old male with atherosclerotic occlusion of the internal carotid artery (Case 2) were scheduled for bypass surgery using a scalp artery, the superficial temporal artery and the posterior auricular artery, respectively. The candidate scalp arteries were preoperatively marked using a handheld Doppler ultrasonic flowmeter. Cutdowns were made along the markings, however, the arteries were not found. In Case 1 the superficial temporal vein was exposed at the cutdown site; posterior extension of the incision revealed the donor artery. In Case 2 we were unable to identify the intended donor artery and a thin branch of the superficial temporal artery was used instead. Although the donor vessels were successfully anastomosed in both patients they developed partial alopecia. Postoperative radiological review revealed that the cutdowns were made on scalp veins, i.e. the veins were misidentified as donor arteries by the Doppler ultrasonic flowmeter. Conclusion: As such misidentification hampers the success of the cutdown method for preventing cutaneous ischemia and complicates the operation, preoperative marking of the donor arteries must consider the possibility of their misidentification.