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Year : 2012  |  Volume : 60  |  Issue : 6  |  Page : 604--607

Intraoperative assessment of STA-MCA bypass patency using near-infrared indocyanine green video-angiography: A preliminary study

Sudheer Ambekar, Arun Babu, Paritosh Pandey, Indira B Devi 
 Department of Neurosurgery, National Institute of Mental Health and Neurosciences, Bangalore, Karnataka, India

Correspondence Address:
Paritosh Pandey
Department of Neurosurgery, NIMHANS, Hosur Road, Bangalore, Karnataka


Background: Bypass patency is critical for patients undergoing superficial temporal artery-middle cerebral artery (STA-MCA) anastomosis. Near-infrared indocyanine green video-angiography (ICGA) is an excellent method to assess vessels during cerebrovascular surgery. Objective: The aim of the present study is to analyze the effectiveness of ICGA in patients undergoing STA-MCA anastomosis for moyamoya disease. Materials and Methods: This study was a retrospective review of case records and operation records of patients who underwent STA-MCA bypass for moyamoya disease at our institute. Concordance of ICGA with intraoperative micro-Doppler and postoperative angiography, whenever available, was assessed. Results: In all, 22 STA-MCA anastomoses were performed in 13 patients. ICGA was used to assess patency in 14 surgeries (10 patients). No patient required revision of anastomosis following ICGA. Postoperative angiography was done in five anastomoses (three patients) at three months follow-up and correlated well with ICGA findings in all cases. Conclusion: ICGA is an effective technique to assess bypass patency during cerebrovascular surgery. Routine use of ICGA in cerebral bypass surgery improves graft patency and minimizes complications due to graft occlusion.

How to cite this article:
Ambekar S, Babu A, Pandey P, Devi IB. Intraoperative assessment of STA-MCA bypass patency using near-infrared indocyanine green video-angiography: A preliminary study.Neurol India 2012;60:604-607

How to cite this URL:
Ambekar S, Babu A, Pandey P, Devi IB. Intraoperative assessment of STA-MCA bypass patency using near-infrared indocyanine green video-angiography: A preliminary study. Neurol India [serial online] 2012 [cited 2021 Sep 27 ];60:604-607
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Full Text


Near-infrared indocyanine green video-angiography (ICGA) is being used increasingly in neurosurgery since its first application by Feindel et al., [1] in 1967 to visualize vessels during aneurysm surgery. Besides aneurysm surgery, ICGA is being used for assessment of bypass patency, planning arteriovenous malformation (AVM) surgery, planning dural opening during tumor surgery, assessing cross-circulation during surgery and when contemplating cortical venous sacrifice during surgery. [2] The limitation of ICGA in not being able to visualize unexposed vessels has been partially overcome by using an endoscope to visualize these vessels. [2] The use of ICGA has been reported in aneurysm surgery and spinal vascular malformations by Misra et al. [3] However, the use of ICGA in India to assess bypass patency in superficial temporal artery-middle cerebral artery (STA-MCA) anastomosis has not been reported earlier. We present our experience with ICGA during STA-MCA anastomosis surgery for moyamoya disease.

 Materials and Methods

We started performing ICGA at our institute from May 2011 after procurement of the microscopes compatible with ICG. We retrospectively reviewed our data for patients undergoing end-to-side STA-MCA anastomosis for Moyamoya disease. Demographic profile, clinical manifestations and follow-up status were noted from the case records. Patients were grouped according to the Suzuki and Takaku classification. [4] Assessment of bypass patency was done by visual inspection, intraoperative micro-Doppler and ICGA. Routine postoperative computed tomography (CT) scan was performed to look for any postoperative infarcts secondary to occluded anastomosis. We do not perform routine postoperative angiography, and it was done at follow-up at three months.

Indocyanine green video-angiography technique

After STA-MCA anastomosis, bypass patency is first assessed visually by filling of the proximal and distal middle cerebral artery. ICG, which is available in India under the trade name Aurogreen (Aurogreen® , Aurolab, Madurai, Tamil Nadu) is reconstituted using 5-ml sterile water and injected intravenously in a dose of 0.3 mg/kg. The fluorescence microscope should be turned on during this procedure. Care must be taken that no blood clots or surgical patties obstruct the view. The recommended dose of ICG is 0.2-0.5 mg/kg with a maximum dose not exceeding 5 mg/kg. The assessment of bypass patency is done with a single injection of the dye. In case the anastomosis needs revision, repeat ICGA may be done till a maximum dose of 5 mg/kg.


Over the past one year, 22 STA-MCA anastomoses were done in 13 patients with moyamoya disease at our institution. ICGA has been used to assess patency of anastomosis in 14 surgeries (10 patients). The patients' age ranged from 5-32 years (median 11 years). There were six patients in the pediatric age group (less than 18 years). Majority of our patients presented with ischemic symptoms such as recurrent strokes and seizures. Only one patient presented with a past history of bleed [Table 1]. There were two patients in Suzuki Stage II and four patients each in Stages III and IV [Table 2].{Table 1}{Table 2}

In all the patients, bypass patency was assessed by visual inspection. Following the completion of the anastomosis and hemostasis, ICG was injected as a bolus, and the pattern of filling of the anastomosis was analyzed. In a patent anastomosis, the donor artery (in this case, STA) should fill first, followed by distal and proximal segments of the recipient artery (in this case, M4 segment of MCA). All the anastomoses were patent. The patency of the anastomosis was also checked with intraoperative micro-Doppler, and all the anastomoses were patent. Revision of anastomosis was not required in any patient and a single injection of ICG was done in all the patients to assess the patency of anastomosis. There were no adverse reactions due to use of ICG.

There were no complications following STA-MCA bypass. Postoperative CT scan done after two days did not show evidence of any fresh infarcts in any patient, indirectly indicating that the anastomoses were patent. There was no recurrence of stroke or transient ischemic attacks in any patient during follow-up. There was mild improvement in hemiparesis in two patients. Postoperative digital subtraction angiography (DSA) was done in five anastomoses (three patients) at three months follow-up. It typically showed filling of the STA followed by flow across bypass to the MCA and the cortical branches. The internal carotid artery (ICA) was visualized with faint filling. All the bypasses were patent, with good revascularization to the hemispheres.

Illustrative case

A 34-year-old male presented with partially improved left hemiplegia of six months' duration. He also had episodes of transient right hemiparesis and speech difficulty for the past three months. On examination, he had left hemiparesis, motor power of 3/5 in the upper limbs and 4/5 in the lower limbs. Magnetic resonance imaging (MRI) showed old infarct in the right subcortical white matter as well as watershed infarcts. He also had small infarcts on the left side. DSA revealed complete occlusion of both the supraclinoid ICAs just distal to the origin of the posterior communicating arteries, along with formation of multiple leptomeningeal collaterals suggestive of moyamoya disease. He underwent cerebral revascularization with bilateral STA-MCA bypass for moyamoya disease. Parietal branch of STA was anastomosed to a M4 cortical branch of MCA [Figure 1]a-d, and ICG was performed after the anastomosis, which revealed patent anastomosis. [Figure 2]a and b show the intraoperative photograph and ICG angiogram of STA-MCA bypass in another patient with moyamoya disease.{Figure 1}{Figure 2}


Moyamoya disease is a chronic disorder characterized by progressive occlusion of bilateral supraclinoid ICA and the development of leptomeningeal collaterals along the base of the brain. The spectrum of clinical manifestations varies from ischemic stroke and seizures due to stenosis of ICAs on one end to bleed from rupture of the leptomeningeal collaterals on the other. The progression of the disease process was elucidated by Suzuki and Takaku in 1969 and they divided the patients into six stages [4] based on their angiographic appearance [Table 2]. To date, medical management has not been successful to prevent the progression of the disease or to restore blood flow to the ischemic areas and hence, surgery has been the mainstay in the management of these patients. Numerous direct and indirect revascularization procedures have been described to restore blood flow to the brain. STA-MCA bypass for moyamoya disease was first reported by Karasawa et al., [5] in 1978 and since then has been used widely for the treatment of moyamoya disease.

The efficacy of STA-MCA bypass surgery for treatment of moyamoya disease, and in patients with complex aneurysms or tumors where parent vessel sacrifice is necessary is well established. Intraoperative assessment of anastomosis is an important issue in bypass surgery. Occlusion of graft leads to infarcts and fresh neurological deficits, and hence peri-operative assessment of graft patency is of utmost importance in intracranial anastomosis. Visual inspection may fail to detect graft occlusion as the postoperative bypass patency rate is reported to be between 90-96%. [6],[7] Hence there is a need for adjuncts to assess bypass patency. Intraoperative micro-Doppler and ICGA are useful alternatives to angiography which is the gold standard for assessing bypass patency. Micro-Doppler has limitations with respect to image quality and spatial resolution. Intraoperative angiography is time-consuming, cumbersome and requires personnel. ICG video angiography has the advantage of excellent visualization, as well as speed and ease of administration. ICG is available in India at an affordable cost (Rs.1300 per vial) and offers an excellent alternative to intraoperative angiography. The adverse effects of ICGA are minimal as it has a short plasma half-life of 3 to 4 min and is not metabolized by the body. The use of ICG video angiography has been reported from India in patients with aneurysms, high-flow bypass and spinal vascular malformations. [3] This is the first large report from India describing the use of ICGA in patients undergoing STA-MCA bypass. Woitzik et al., [8] reported 40 patients with varied diagnoses undergoing extracranial and intracranial (EC-IC) bypass who underwent ICGA. They reported four patients with non-functioning STA-MCA anastomoses and two patients with saphenous vein high-flow bypass which were detected during ICGA and required revision. In all the cases ICGA findings correlated with postoperative angiography findings as in our series. In another study, Schuette et al., [9] reported four suboptimal anastomoses detected by ICGA which required revision. In our series, ICGA did not result in revision of anastomosis in any case.

There are certain limitations to our study. This is a preliminary observation and experience. The lack of postoperative angiography for patients is a major limitation. The duration of follow-up is short and the number of patients is small. Long-term follow-up and larger number of patients is needed to assess the efficacy of direct revascularization. In conclusion we feel that ICGA is an excellent technique to assess intraoperative bypass patency.


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