Intraoperative Indocyanine Green Fluorescence Angiography Research Articles

Microscope-Integrated Quantitative Analysis of Intraoperative Indocyanine Green Fluorescence Angiography for Blood Flow Assessment

Intraoperative measurements of cerebral blood flow are of interest during vascular neurosurgery. Near-infrared indocyanine green (ICG) fluorescence angiography was introduced for visualizing vessel patency intraoperatively. However, quantitative information has not been available. To report our experience with a microscope with an integrated dynamic ICG fluorescence analysis system supplying semiquantitative information on blood flow. We recorded ICG fluorescence curves of cortex and cerebral vessels using software integrated into the surgical microscope (Flow 800 software; Zeiss Pentero) in 30 patients undergoing surgery for different pathologies. The following hemodynamic parameters were assessed: maximum intensity, rise time, time to peak, time to half-maximal fluorescence, cerebral blood flow index, and transit times from arteries to cortex. For patients without obvious perfusion deficit, maximum fluorescence intensity was 177.7 arbitrary intensity units (AIs; 5-mg ICG bolus), mean rise time was 5.2 seconds (range, 2.9-8.2 seconds; SD, 1.3 seconds), mean time to peak was 9.4 seconds (range, 4.9-15.2 seconds; SD, 2.5 seconds), mean cerebral blood flow index was 38.6 AI/s (range, 13.5-180.6 AI/s; SD, 36.9 seconds), and mean transit time was 1.5 seconds (range, 360 milliseconds-3 seconds; SD, 0.73 seconds). For 3 patients with impaired cerebral perfusion, time to peak, rise time, and transit time between arteries and cortex were markedly prolonged (>20, >9 , and >5 seconds). In single patients, the degree of perfusion impairment could be quantified by the cerebral blood flow index ratios between normal and ischemic tissue. Transit times also reflected blood flow perturbations in arteriovenous fistulas. Quantification of ICG-based fluorescence angiography appears to be useful for intraoperative monitoring of arterial patency and regional cerebral blood flow.

Letter to the editor: multimodal treatment of co-existent callosal cavernous malformation and anterior communicating artery aneurysm associated with an infraoptic anterior cerebral artery

Dear Sir, We wish to bring to your attention the neuroradiological findings in a 40-year-old woman who presented with a sentinel headache. Neuroimaging revealed a hemorrhagic cavernous malformation in the body of the corpus callosum and an anterior communicating artery (ACoA) aneurysm (Fig. 1a and b). Aneurysmal subarachnoid hemorrhage was excluded on the basis of computed tomography and lumbar puncture. The aneurysm measured 1.2 cm on a catheterbased angiogram; an early carotid bifurcation at the level of the ophthalmic artery (OA) origin and a horizontal course of the right A1 segment (the only A1) were also noted (Fig. 2a and b). Given the higher risk of rupture of the aneurysm, the patient underwent coil embolization of the aneurysm. The patient did well, but significant aneurysm recurrence was documented on the follow-up angiogram. She underwent microsurgical clipping through a right-sided transsylvian approach. Intraoperatively, the right A1 was seen to originate from the carotid artery at the level of the OA, coursing beneath the optic nerve to supply the ACoA aneurysm (Fig. 3). Intraoperative indocyanine green fluorescence angiography (Fig. 4) and postoperative conventional angiography revealed total aneurysm occlusion. To our knowledge, the present report is the first case of an infraoptic anterior cerebral artery (ACA) in association with a cavernous malformation. This is also the first reported case of multimodal treatment of an infraoptic ACoA aneurysm variant. The origin of an infraoptic ACA remains speculative. Enlargement of the prechiasmal arterial plexus, persistence and enlargement of an anastomotic loop between the primitive dorsal and ventral OAs and persistence of a fetal anastomosis between the primitive maxillary artery, and the ACA have all been implicated [1–3]. The aberrant anastomosis often leads to agenesis of ipsilateral and contralateral A1 segments [4]. Infraoptic ACAs are classified according to local vascular anatomy [5]. The type I configuration has a normal ACoA complex with an additional infraoptic vessel P. Kan : P. Yashar :A. J. Chamczuk : E. I. Levy : L. N. Hopkins : A. H. Siddiqui (*) Department of Neurosurgery, University at Buffalo, State University of New York, 3 Gates Circle, Buffalo, NY 14209, USA e-mail: asiddiqui@ubns.com

Preliminary evaluation of the role of surgical microscope-integrated intraoperative FLOW 800 colored indocyanine fluorescence angiography in arteriovenous malformation surgery

To discuss the role of FLOW 800 innovative software for analytical color visualization and objective evaluation of fluorescence videos obtained by microscope-integrated intraoperative indocyanine green (ICG) fluorescence angiography in arteriovenous malformations (AVM) surgery. Microscope-integrated intraoperative FLOW 800 was used and evaluated in three consecutive AVM surgeries over a period of two months. The role of FLOW 800 to distinguish feeding arteries from arterialized veins and other arteries was evaluated. Its advantages and limitations over conventional intraoperative ICG angiography were evaluated. This software was found to be useful in identifying arterial feeders, arterialized veins and other arteries in all the three patients and it gives additional information on the status of AVM before and after clipping suspected feeders which is sometimes difficult to interpret on conventional ICG angiography. Flow 800 is a reliable and useful addition to microscope-integrated color ICG video angiography. Although its role is limited in deep-seated AVMs, if properly dissected and exposed it can give useful information which can be easily interpretable and reproducible.

The Role of Intraoperative Indocyanine Green Fluorescence Angiography in Pediatric Cardiac Surgery

In surgical reconstructions for congenital heart defects, vessel and anastomotic site patency is critical to success. Indocyanine green fluorescence angiography offers potential for a reliable and rapid method of intraoperative assessment. We sought to determine its feasibility in congenital heart surgery. Patients undergoing the following repairs were eligible for imaging: (1) coronary artery reimplantation, (2) coarctation, (3) palliative shunts, and (4) pulmonary artery reconstruction. Adequate postoperative images were obtained in 18 of 30 (60%) patients. Image adequacy was highest for Blalock-Taussig shunts (100%), coarctation repairs (86%), coronary reimplantations (66%), lowest for the hemi-Fontan (0%), Fontan (40%), and pulmonary artery reconstructions (33%). All adequate images showed vessel or anastomotic site patency, which corresponded to the subsequent postoperative echocardiograms and cineangiograms. There were no adverse events or mortalities. Indocyanine green fluorescence imaging may provide an additional intraoperative imaging modality. Ultimately, the surgical procedure may be assessed and revised, if necessary, prior to leaving the operating room. This potentially will reduce the need for subsequent postoperative interventions, along with their associated morbidity and mortality.

Abstract: P1418 GRAPE FLAVONOIDS, IN PROVEX CV® DECREASE THE INFLAMMATORY RESPONSE CAUSED BY SECRETORY PHOSPHOLIPASE A2 ACTIVITY IN RATS

Because the fluorescent light intensity on an indocyanine green fluorescence angiography reflects the blood perfusion within a focused area, the fluorescent light intensity in the remaining in situ parathyroid glands may predict postoperative hypocalcemia risk after total thyroidectomy.Seventy patients underwent intraoperative indocyanine green fluorescence angiography after total thyroidectomy. Any parathyroid glands with a vascular pedicle was left in situ while any parathyroid glands without pedicle or inadvertently removed was autotransplanted. After total thyroidectomy, an intravenous 2.5 mg indocyanine green fluorescence angiography was given and real-time fluorescent images of the thyroid bed were recorded using the SPY imaging system (Novadaq, Ontario, Canada). The fluorescent light intensity of each indocyanine green fluorescence angiography as well as the average and greatest fluorescent light intensity in each patient were calculated. Postoperative hypocalcemia was defined as adjusted calcium <2.00 mmol/L within 24 hours.The fluorescent light intensity between discolored and normal-looking indocyanine green fluorescence angiographies was similar (P = .479). No patients with a greatest fluorescent light intensity >150% developed postoperative hypocalcemia while 9 (81.8%) patients with a greatest fluorescent light intensity ≤150% did. Similarly, no patients with an average fluorescent light intensity >109% developed PH while 9 (30%) with an average fluorescent light intensity ≤109% did. The greatest fluorescent light intensity was more predictive than day-0 postoperative hypocalcemia (P = .027) and % PTH drop day-0 to 1 (P < .001).Indocyanine green fluorescence angiography is a promising operative adjunct in determining residual parathyroid glands function and predicting postoperative hypocalcemia risk after total thyroidectomy.

The Application of Laser-Assisted Indocyanine Green Fluorescent Dye Angiography in Microsurgical Breast Reconstruction

The benefits of laser-assisted indocyanine green fluorescence angiography have previously been demonstrated in cardiac surgery. The purpose of this study was to determine the value of this technology in microsurgical breast reconstruction. Intraoperative laser-assisted indocyanine green fluorescence angiography was performed on all microsurgical breast reconstruction cases (deep inferior epigastric perforator flap or free transverse rectus abdominus muscle flap) during the study period. Ten consecutive free tissue transfer autologous breast reconstructions were performed on 8 women. In four cases, imaging demonstrated flow or perfusion deemed "marginal" or "poor" by the operating surgeons. In three of these cases, one involving poor arterial inflow, one of poor venous outflow, and one of poor perfusion of a mastectomy flap, the intraoperative plan was adjusted accordingly and follow-up imaging demonstrated improvement. In the fourth case, no adjustment was made at operation. However this patient required a return to the operating room for venous congestion of the flap, which was corrected without sequela. Overall flap survival was 100%. We concluded that laser-assisted indocyanine green fluorescence angiography appears to provide important information that has helped guide intraoperative decision making in our series.

Intraoperative use of dynamic infrared thermography and indocyanine green fluorescence video angiography to predict partial skin flap loss

Inadequate perfusion is the most common cause of partial flap loss in reconstructive surgery. Intraoperative monitoring of flap perfusion may prevent such loss. This study compared indocyanine green fluorescence angiography (ICG-FA) and dynamic infrared thermography (DIRT) in their ability to predict intraoperatively the percentage of flap survival in a caudally based McFarlane flap in 10 male Wistar rats. The intraoperative images of both techniques were subjectively and objectively analysed. The percentage of flap survival, as judged from the digital colour photographs 7 days post-operatively, was 69 ± 3%. Objective analysis of flap survival based on intraoperative DIRT and ICG-FA (74 vs 63%, respectively) correlated quite well with the subjective measurements (75 ± 2 vs 59 ± 4%, respectively). However, intraoperative ICG-FA images underestimated flap survival by 6–10%, while intraoperative DIRT images overestimated the flap survival by 5–6%. The authors conclude that intraoperative use of ICG-FA and DIRT can provide valuable information on areas with inadequate perfusion as long as their limitations are respected.