Pathological Findings of Donor Vessels in Bypass Surgery

(1) Background Cerebral revascularization is necessary to treat intracranial arterial stenosis caused by moyamoya disease, atherosclerosis, or large complex aneurysms. Although various donor vascular harvesting methods have been reported safe, there are no reports on the histological evaluation of donor vessels for each disease, despite the variety of diseases wherein vascular anastomosis is required. (2) Methods Pathological findings of the superficial temporal artery (STA), radial artery (RA), occipital artery (OA), and saphenous vein (SV) harvested at the institution were analyzed. Patients classified according to aneurysm, atherosclerosis, and moyamoya disease were assessed for pathological abnormalities, medical history, age, sex, smoking, and postoperative anastomosis patency. (3) Results There were 38 cases of atherosclerosis, 15 cases of moyamoya disease, and 30 cases of aneurysm in 98 donor vessels (mean age 57.2) taken after 2006. Of the 84 STA, 11 RA, 2 OA, and 1 SV arteries that were harvested, 71.4% had atherosclerosis, 11.2% had dissection, and 10.2% had inflammation. There was no significant difference in the proportion of pathological findings according to the disease. A history of hypertension is associated with atherosclerosis in donor vessels. (4) Conclusions This is the first study to histologically evaluate the pathological findings of donor vessels according to disease. The proportion of dissection findings indicative of vascular damage due to surgical manipulation was not statistically different between the different conditions.

Experience Using Gentian Violet-Free Dyes for Tissue Visualization

BACKGROUND

 Gentian violet ink is used as a skin marker in various surgical procedures, including neurosurgery. The dye is also used to visualize the edges of blood vessels during bypass surgery. However, gentian violet ink carries the risks of carcinogenicity and venous injury, which causes microvascular thrombosis. In this study, we compare the gentian violet-free dye C.I. Basic Violet 4 (BV4) and gentian violet. The usefulness, in terms of color, and formation of microvascular thrombosis in anastomosis were compared.

METHODS

 We used the gentian violet-free dye in 20 cases involving 3 vascular anastomoses. The bone cutting lines on the bone surface, superior temporal artery, and middle cerebral artery were drawn using BV4 and gentian violet ink.

RESULTS

 The colors of BV4 and gentian violet ink were similar. No thrombus formation was observed at the vascular anastomosis when using BV4.

CONCLUSION

 BV4 can be used similarly to gentian violet ink. No adverse effects such as thrombus formation in microvascular anastomosis were experienced when BV4 was used.

Spontaneous middle cerebral artery dissection: a series of six cases and literature review

Middle cerebral artery (MCA) dissection is rare, and various clinical presentations, including hemorrhage, ischemia, or comorbidities, and the changes in imaging findings over time hinder treatment decisions. The European Stroke Organization guidelines exclude MCA dissection. Few cases have been reported with no review of the relevant literature. Therefore, we reviewed the relevant literature and our own experience with non-traumatic MCA dissection cases to determine appropriate treatment strategies. At our institution and affiliated institutions, we encountered six cases of MCA dissection-five with infarction and one with hemorrhage. Two patients underwent revascularization, and one underwent an aneurysmectomy. We reviewed English and Japanese articles in PubMed and Medical Journal Web and summarized the results based on the relationships among age, sex, location, the presence of an aneurysm, the presence of angiography, history, treatment, and mode of onset. The clinical course, changes in imaging, treatment strategies, and prognosis were discussed. Eighty cases were included in the review. Cerebral aneurysms were more common distal to the M2 area (p = 0.00) and were correlated with hemorrhage (p < 0.001). Most hemorrhagic cases with aneurysms were treated surgically, while ischemic cases were treated with antithrombotic agents, and both had a similar neurological prognosis. There were some cases of rebleeding after antithrombotic therapy, especially in older adults.Surgical treatment is recommended in cases of hemorrhage and confirmed aneurysms, particularly for lesions distal to the M2 area. Patients with aneurysm-associated ischemia should be followed up, and antithrombotic treatment should be considered with particular care in older adults.

Evaluation of Ethyl Violet as an Alternative Dye to Crystal Violet to Visualize the Vessel Wall during Vascular Anastomosis

Crystal violet (CV) ink has been used as a skin marker worldwide. It has been reported to be useful for vessel wall visualization of microvascular anastomoses. Contrastingly, it has been found to be carcinogenic and inhibit migration and proliferation of venous cells. In some countries, its use in the medical field has been restricted. Therefore, it is necessary to consider alternatives to CV. In this present study, we compared the time required for the anastomosis of a 0.8-1 mm diameter vessel in the chicken wrist artery using CV and a CV-free dye (ethyl violet; EV). The surgeon, microscope, and anastomosis microsurgical tools were standardized for comparison. CV and EV were changed for each anastomosis. The same surgeon performed 30 anastomoses using each dye. No visually obvious differences were noted in the vascular transections with CV and EV. As per the results, no statistically significant difference was observed in the time required for anastomosis using CV and EV. EV conforming to California Proposition 65 may be an effective alternative to CV for vascular visualization of microvascular anastomoses. However, further studies on the effectiveness of the EV in clinical cases are needed.