Ruptured de novo aneurysm arising at a site remote from the anastomosis 14 years after superficial temporal artery-middle cerebral artery bypass: a case report

Recipient artery dissection during extracranial-intracranial bypass surgery: Two case reports

BACKGROUND

Superficial temporal artery to middle cerebral artery (STA-MCA) bypass is a valuable treatment for preventing ischemia and hemorrhage in occlusive cerebrovascular disease. Anastomosis site dissection is rarely reported among the various bypass-related complications.

CASE SUMMARY

In this case report, we describe two patients, who were 63- and 59-years-old with middle cerebral artery occlusion treated by STA-MCA bypass. During bypass surgery, the recipient M4 artery intima was dissected. We sacrificed the dissecting portion, and no complications occurred during the follow-up period. Postoperative brain imaging revealed improved brain perfusion. We report rare cases of recipient artery dissection located in the extracranial to intracranial bypass site, and we suggest atherosclerotic changes in the recipient artery and insufficient puncture as the causes.

CONCLUSION

Appropriate recipient artery selection is critical, and if dissection occurs, it is essential to sacrifice the dissecting portion quickly.

Newly Developed Aneurysm at the Anastomosis Site of a Superficial Temporal Artery to Middle Cerebral Artery Bypass Successfully Treated by Endovascular Embolization

BACKGROUND

The superficial temporal artery (STA) to middle cerebral artery (MCA) bypass is an effective treatment procedure for steno-occlusive severe ischemic disease of the anterior circulation. The formation of an aneurysm at the anastomosis site is a rare complication, and the mechanism underlying this condition and the appropriate treatment strategy, have not yet been established. We describe a case of an unruptured anastomosis aneurysm that was treated by endovascular embolization 7 years after bypass surgery.

CASE DESCRIPTION

A 62-year-old woman presented with slurred speech, with magnetic resonance imaging and angiography showing multiple infarctions in her left cerebral hemisphere and severe stenosis in the left internal carotid artery and left MCA. An STA-MCA anastomosis was performed without neurologic sequelae. Five years later, follow-up magnetic resonance imaging showed that an aneurysm had formed at the MCA side of the anastomosis site. After 2 years, the saccular aneurysm had grown and was embedded in the brain parenchyma. Because the patient had experienced repeated problems with surgical wound healing, an endovascular intervention was performed, achieving obliteration of the aneurysm by coil embolization.

CONCLUSIONS

Endovascular treatment is a feasible and efficacious treatment option for an aneurysm at the anastomosis site of an STA-MCA bypass.

Rapid Development of an Aneurysm at the Anastomotic Site of a Superficial Temporal Artery to Middle Cerebral Artery Bypass: Case Report and Literature Review

BACKGROUND

Direct extracranial to intracranial (EC-IC) bypass is a valuable treatment option for symptomatic occlusive cerebrovascular disease and complex intracranial aneurysms. Aneurysm formation at or near the anastomotic site is a rarely reported phenomenon, and the pathophysiology and appropriate management of such de novo aneurysms are not clear.

CASE DESCRIPTION

Here we present the case of a superficial temporal to middle cerebral artery (STA-MCA) anastomosis that was complicated by aneurysm formation at the anastomotic site. This was treated with microsurgical clipping with preservation of the bypass. Pathologic analysis of the lesion was consistent with a pseudoaneurysm. We provide a literature review of this phenomenon, which is most often associated with low-flow STA-MCA bypasses, including review of the pathologic findings associated with it.

CONCLUSION

Pseudoaneurysm formation at the site of an EC-IC bypass is a rare phenomenon that should be recognized and treated to prevent further growth and rupture.

Endovascular treatment of middle cerebral artery aneurysm with a (LVIS) device: Comparison of LVIS stent and non-LVIS stent

Middle cerebral artery (MCA) aneurysm is a serious medical condition mainly occurring in the proximal and bifurcation tracts. Evidence has indicated that endovascular treatment is an effective surgical method for patients with MCA aneurysm. In the present study, the efficacy of endovascular treatment with low-profile visualized intraluminal support (LVIS) stent for MCA aneurysms was evaluated in comparison with that using a non-LVIS stent device. A total of 92 patients who underwent endovascular treatment of MCA aneurysms with LVIS stent or non-LVIS stent were included in the present study. The clinical presentation, aneurysmal characteristics, technical feasibility, procedural complications, as well as angiographic and clinical follow-up results were analyzed. The computed tomography scan demonstrated that endovascular treatment with LVIS stent markedly reduced pre-operative and intra-operative ruptures. It was indicated that endovascular treatment with LVIS stent resulted in less post-operative symptoms and cases of disability according to the modified Rankin scale score. In conclusion, the present outcomes provide evidence that endovascular treatment with an LVIS stent is an efficient method for the treatment of MCA aneurysm.

De Novo Aneurysm Associated with Superficial Temporal Artery to Middle Cerebral Artery Bypass: Report of Two Cases and Review of Literature

BACKGROUND

De novo aneurysm formation has been reported as a rare complication of superficial temporal artery (STA) to middle cerebral artery (MCA) bypass surgery.

CASE DESCRIPTION

The first patient with intracerebral hemorrhage had a ruptured de novo aneurysm arising from the recipient MCA at 6 years after undergoing STA-MCA bypass for hemispheric hemodynamic insufficiency. In the second case, an enlarging unruptured STA aneurysm was detected by follow-up magnetic resonance angiography at 8 years after the patient underwent STA-MCA bypass for moyamoya disease. Both patients were successfully treated by surgical clipping.

CONCLUSIONS

Persistent hemodynamic stress with hypertension in an artificial T-shaped vasculature and traumatic injury during surgical manipulation are the most important causes for de novo aneurysms after STA-MCA bypass. Follow-up magnetic resonance and computed tomography angiography examinations, along with appropriate blood pressure control, are recommended for patients who have undergone STA-MCA bypass surgery.

Progress on Complications of Direct Bypass for Moyamoya Disease

Moyamoya disease (MMD) involves progressive occlusion of the intracranial internal carotid artery resulting in formation of moyamoya-like vessels at the base of the brain. It can be characterized by hemorrhage or ischemia. Direct vascular bypass is the main and most effective treatment of MMD. However, patients with MMD differ from those with normal cerebral vessels. MMD patients have unstable intracranial artery hemodynamics and a poor blood flow reserve; therefore, during the direct bypass of superficial temporal artery (STA)-middle cerebral artery (MCA) anastomosis, perioperative risk factors and anesthesia can affect the hemodynamics of these patients. When brain tissue cannot tolerate a high blood flow rate, it becomes prone to hyperperfusion syndrome, which leads to neurological function defects and can even cause intracranial hemorrhage in severe cases. The brain tissue is prone to infarction when hemodynamic equilibrium is affected. In addition, bypass vessels become susceptible to occlusion or atrophy when blood resistance increases. Even compression of the temporalis affects bypass vessels. Because the STA is used in MMD surgery, the scalp becomes ischemic and is likely to develop necrosis and infection. These complications of MMD surgery are difficult to manage and are not well understood. To date, no systematic studies of the complications that occur after direct bypass in MMD have been performed, and reported complications are hidden among various case studies; therefore, this paper presents a review and summary of the literature in PubMed on the complications of direct bypass in MMD.

Repeated de novo aneurysm formation after anastomotic surgery: Potential risk of genetic variant RNF213 c.14576G>A

Background:

De novo aneurysm formation after intracranial anastomotic surgery is a relatively rare complication with fewer than 20 reported cases, and the mechanism is still unclear.

Case Description:

A 63-year-old male treated for symptomatic internal carotid artery occlusion developed de novo aneurysms twice after anastomoses first of the superficial temporal artery-middle cerebral artery and second of the external carotid artery-radial artery-middle cerebral artery over a 10-year period. The first de novo aneurysm was successfully resected with pathological diagnosis of true aneurysm. The second de novo aneurysm thrombosed naturally after gradual growth. Genetic testing of the patient revealed the c.14576G>A (p.R4859K) variant in ring finger protein 213, which is a susceptibility gene for moyamoya disease.

Conclusions:

This genetic variant was probably involved in the repeated de novo aneurysm formation, and this case represents a rare phenotype of the genetic variant.