Objective assessment of remnant pancreatic perfusion using intraoperative indocyanine green angiography: a novel technique to predict postoperative pancreatic fistula.

Objective To investigate the hemodynamic monitoring and clinical significance of transcranial Doppler (TCD) combined with indocyanine green (ICG) fluorescence angiography and FLOW 800 in carotid endarterectomy (CEA). Methods Forty-eight patients with extracranial carotid atherosclerotic stenosis underwent CEA in our hospital from October 2015 to September 2018 were chosen to our study. The mean blood flow velocity (Vm) of the middle cerebral artery (MCA) was monitored by TCD throughout the operation. The intraoperative blood pressures were adjusted according to the monitoring results, and the average blood Vm of the narrowed arteries was measured using TCD probe before and after artery temporary occlusion. ICG fluorescence angiography and FLOW 800 were used to monitor vascular morphology and patency simultaneously. Results One patient, who was observed to have severe stenosis by TCD, ICG fluorescence angiography, and FLOW 800 after arteries temporary occlusion, showed significantly improved by multimodal monitoring after re-suture; one patient showed external carotid artery occlusion by ICG fluorescence angiography and FLOW 800 had no external carotid artery occlusion; other 46 patients showed no carotid artery stenosis and good intracranial perfusion by TCD, ICG fluorescence angiography, and FLOW 800 after initial suture. Two patients developed ischemic stroke (IS) after CEA, and both of them were recovered after conservative medical treatment for two weeks without any neurological dysfunction; two patients had cerebral hyperperfusion syndrome (CHS), and both of them relieved after blood pressure control three d after treatment; one patient had subcutaneous hematoma in the operation area, and the hematoma was gradually absorbed after conservative treatment; the rest patients recovered well. All patients were followed up for 4-6 months after CEA, and CT angiography showed that carotid artery stenosis was relieved; CT perfusion imaging and TCD examinations showed that cerebral perfusion was significantly improved as compared with those before operation. Conclusion Intraoperative TCD combined with ICG fluorescence angiography and FLOW 800 can effectively monitor the intracranial and extracranial blood flow of intraoperative carotid artery, which is of great significance in reducing the risk of IS and CHS during carotid endarterectomy. Key words: Carotid stenosis; Carotid endarterectomy; Transcranial Doppler; Indocyanine green fluorescence angiography; FLOW 800

Introduction: Esophageal cancer ranks among the most aggressive neoplasms worldwide and is a significant contributor to cancer-related mortality. Surgical intervention through esophagectomy with radical lymph node dissection remains a cornerstone in the curative treatment of mid and lower esophageal and gastroesophageal junction tumors, often preceded by neoadjuvant therapy tailored to histological type. Anastomotic leak (AL) following gastroesophageal anastomosis is a major complication associated with substantial morbidity and mortality. Methods: A prospective study was conducted on 30 patients undergoing esophagectomy with gastric conduit reconstruction from May 2023 to April 2024. Gastroesophageal anastomosis was placed at neck. Intraoperatively, indocyanine green (ICG) fluorescence angiography was employed to assess gastric conduit perfusion. The anastomosis site was selected based on ICG fluorescence dynamics, aiming for anastomosis within 45 seconds of ICG enhancement. Results: The study cohort comprised predominantly male patients (60%) with a mean age of 60.67 years. Most patients presented with squamous cell carcinoma (66.67%), primarily located in the lower esophagus and minimally invasive surgery was predominantly performed. Mean ICG fluorescence angiography time was 32.1 seconds. Anastomotic leak occurred in 23.3% of patients, correlating with significantly longer hospital stays (p=0.005). Although ICG fluorescence angiography was used to guide anastomosis based on perfusion assessment, there was no statistically significant reduction in AL rates observed in this study (p=0.471). Conclusion: In conclusion, while ICG fluorescence angiography represents an innovative approach to evaluating gastric conduit perfusion during esophagectomy, its direct impact on reducing AL in our study was not statistically significant.

In thyroid surgery, autofluorescence allows the parathyroid glands (PTGs) to be located very early to protect them. Moreover, indocyanine green (ICG) fluorescence angiography (ICG-FA) allows for assessing the viability of the PTGs and identifying blood vessels to preserve them. The main limitation of using ICG-FA is that once ICG has been injected, it is no longer possible to observe PTG autofluorescence using existing devices. This study aimed to describe an approach that allows for visualization of the PTGs by autofluorescence, even after ICG injection. We redesigned the FLUOBEAM® LX system to excite fluorescence at 685 nm and detect fluorescence between 700 and 900 nm. This device had short-pass filters at 775 nm that helped to split the contributions of the PTG autofluorescence and ICG fluorescence. Tests were performed on extemporaneous PTG preparations placed next to ICG droplets to assess for rejection of the ICG signal. A low-pass filter at 775 nm detected 60% of the autofluorescence signals and 10% of the ICG signals. These findings support the possibility of visualizing PTG autofluorescence despite multiple ICG injections and measuring the balance between ICG and autofluorescence signals.

Indocyanine green (ICG) fluorescence angiography has been used in the assessment of vascular flow. ICG emits nearinfrared fluorescence when it is excited with near-infrared light. Thus, ICG fluorescence is highly transmittable through biological tissues compared with visible light fluorescence. ICG fluorescence was first applied to retinal angiography. In the field of neurosurgery, ICG fluorescence angiography has been used to confirm successful aneurysm clipping during surgery. ICG angiography has also been used for the intraoperative assessment of bypass patency in EC-IC bypass surgery. In the present study, we used ICG angiography to evaluate patency of the bypass graft, as well as blood supply via the bypass to the cortex during superficial temporal artery-middle cerebral artery (STA-MCA) anastomosis in moyamoya disease and non-moyamoya ischemic diseases. We compared changes in cortical perfusion by bypass blood flow between these patients. We compared the cortical areas that were fed by the bypass moyamoya disease and non-moyamoya ischemic diseases. ICG angiography clearly demonstrated bypass blood flow from the anastomosed STA to the cortical vessels, including the arteries, capillaries, and veins in both moyamoya disease and non-moyamoya ischemic diseases. Interestingly, the anastomosed STA supplied blood flow to a larger cortical area in moyamoya disease than non-moyamoya ischemic diseases. The bypass supplied a greater extent of blood flow to the ischemic brain in moyamoya disease than in non-moyamoya ischemic diseases. This difference might be due to the fact that the perfusion pressure was lower in moyamoya disease than that in non-moyamoya ischemic diseases.

BackgroundThere is insufficient evidence on whether indocyanine green (ICG) fluorescence angiography can reduce the incidence of anastomotic leakage (AL). This retrospective cohort study aimed to evaluate the effect of ICG fluorescence angiography on AL rates in laparoscopic rectal cancer surgery at a single institution.MethodsPatients who underwent laparoscopic low anterior resection or intersphincteric resection with ICG fluorescence angiography (ICG group; n = 73) and patients who underwent a similar surgical procedure for rectal cancer without ICG fluorescence (non-ICG group; n = 114) were enrolled consecutively in this study. ICG fluorescence angiography was performed prior to transection of the proximal colon, and anastomosis was performed with sufficient perfusion using ICG fluorescence imaging. AL incidence was compared between both groups, and the risk factors for AL were analyzed.ResultsAL occurred in 3 (4.1%) and 14 (12.3%) patients in the ICG and non-ICG groups, respectively. In the ICG group, the median perfusion time from ICG injection was 34 s, and 5 patients (6.8%) required revision of the proximal transection line. None of the patients requiring revision of the proximal transection line developed AL. In univariate analysis, longer operating time (odds ratio: 2.758; 95% confidence interval: 1.023–7.624) and no implementation of ICG fluorescence angiography (odds ratio: 3.266; 95% confidence interval: 1.038–11.793) were significant factors associated with AL incidence, although the creation of a diverting stoma or insertion of a transanal tube was insignificant.ConclusionICG fluorescence angiography was associated with a significant reduction in AL during laparoscopic rectal cancer surgery. Changes in the surgical plan due to ICG fluorescence visibility may help improve the short-term outcomes of patients with rectal cancer.

Our aim was to evaluate the efficacy of indocyanine green (ICG) fluorescence angiography (FA) in reducing the incidence of anastomotic leakage (AL) following colorectal anastomosis. A single-centre randomized trial was undertaken between 2018 and 2019. Those patients who underwent a stapled colorectal anastomosis were randomized 1:1 for ICG FA versus visual clinical assessment of blood perfusion of the anastomosed colon and rectal stump (non-ICG FA group). The primary end-point was to assess whether ICG FA was associated with a reduction in the incidence of AL. Secondary outcomes were the rate of postoperative complications and change in the level of bowel resection. A total of 380 patients undergoing sigmoid and rectal resection were enrolled. After randomization, three patients were excluded. The results of 377 cases were available for analysis; 187 had ICG FA and 190 were in the non-ICG FA group. ICG FA identified impaired blood perfusion of the colon in 36 (19%) cases. An AL (grade A, B or C) developed in 48 patients: 17 (9.1%) in the ICG FA group and 31 (16.3%) in the non-ICG FA group (P=0.04). ICG FA did not decrease the rate of AL of high anastomoses (9-15cm from the anal verge), at 1.3% vs 4.6% in the non-ICG FA group (P=0.37). In contrast, a decrease in AL rate was found for low (4-8cm) colorectal anastomoses (14.4% in ICG FA vs 25.7% in the non-ICG FA group; P=0.04). ICG FA is associated with a reduction in AL following low anterior resection.

Nonocclusive mesenteric ischemia (NOMI) has a very poor prognosis. It is often difficult to determine the extent to which the necrotic intestine should be resected. We herein report a case in which indocyanine green (ICG) fluorescence angiography was found to be a useful method for diagnosis of NOMI and determination of the extent to which the necrotic intestinal tissue should be resected. A 65-year-old man underwent a second-look operation followed by surgical repair of strangulation of the ileum. A noncontinuous segmental ischemic lesion was detected in the remnant small intestine and cecum. Whether necrotic changes had occurred in the small intestine was difficult to discern. Thus, intraoperative ICG fluorescence angiography was performed with a near-infrared camera system to visualize the blood flow in the intestines and mesentery. ICG fluorescence angiography revealed insufficient blood flow in some parts of the intestine. Based on these findings, ileocecal resection and enterectomy were carried out. Histopathologic examination revealed necrotic changes in all layers of the resected specimens, but no thrombi in the associated blood vessels. The patient received a diagnosis of NOMI based on the findings of intraoperative ICG fluorescence angiography and subsequent histopathologic examination. Intraoperative ICG angiography appears to have the potential to be one of the convenient and useful modalities for the diagnosis and treatment of NOMI.

In surgery for strangulated bowel obstruction, intestinal blood flow (IBF) is usually evaluated by observing bowel colour, peristalsis, intestinal temperature and arterial pulsations in the mesentery. We investigated whether indocyanine green (ICG) fluorescence angiography (ICG-FA) is an effective alternative to palpation. Thirty-eight patients who underwent emergency surgery for strangulated bowel obstruction from January 2017 to April 2021 were divided into two groups: (i) the ICG + group, in which ICG was used during laparoscopic surgery (n = 16), and (ii) the ICG - group, in which palpation without ICG was used during open surgery (n = 22). Starting in July 2019, ICG and laparoscopic surgery were applied in all cases except emergency cases when the fluorescence laparoscope was not ready. Surgical outcomes and patient characteristics were compared. Patient characteristics, theoperative duration and postoperative hospitalization duration did not significantly differ between the groups. Bowel resection was performed in 4 cases (25%) among ICG + patients and 11 cases (50%) among ICG - patients. The ratios of pathological findings (ischaemia:mucosal necrosis:transmural necrosis) were 0:2:2 and 1:6:4 in the two groups, respectively. Blood loss was measured with gauze and suction tubes and was 1 (0-5) mL in the ICG + group and 12.5 (0-73) mL in the ICG - group (p = 0.002). Postoperative complications occurred in 1 case (6.3%) in the ICG + group and 9 cases (40.9%) in the ICG - group (p = 0.025). Although there were few intestinal resections in the ICG + group, the rate of pathological necrosis tended to be high, and no complications due to ineligibility were noted in the intestinal preservation group. During laparoscopic surgery, ICG-FA is useful as a substitute for palpation and has the potential to improve surgical outcomes. Research Ethics Committee of the Kawaguchi Municipal Medical Center (Saitama, Japan) approval number: 2019-40.

The cholecystic veins are thought to be an important metastatic route of gallbladder carcinoma to the liver. In the present study we evaluated the cholecystic venous drainage area, utilizing a novel method, indocyanine green (ICG) fluorescence angiography after superselective catheterization of the cholecystic artery, to detect and elucidate cholecystic venous flow. Cannulation of the cholecystic artery was performed under laparotomy in nine patients who required a cholecystectomy. After ICG injection into the cholecystic artery, the cholecystic venous flow images were visualized with a near-infrared camera system and were analyzed according to site, shape, and time of fluorescence. Fluorescence images of the cholecystic venous flow could be viewed as real-time images in all patients. We demonstrated that the route of the cholecystic venous flow could be classified into two patterns: type 1, in which the cholecystic veins flowed directly into the hepatic parenchyma adjacent to the gallbladder; and type 2, in which the veins flowed into sites separate from the gallbladder. In the type 1 pattern, fluorescence was observed in segment (S; defined according to Couinaud's nomenclature) 4a or S5 adjacent to the gallbladder in all cases. On the other hand, in the type-2 pattern, fluorescence was observed in S4a (6/9), S5 (8/9), S4b (2/9), S3 (2/9), S1 (1/9), S2 (1/9), and S8 (1/9) distant from the gallbladder. Overall, two-thirds of the cases showed fluorescence in segments other than S4a or S5. Indocyanine green (ICG) fluorescence angiography is considered to be a useful method to detect and elucidate cholecystic venous flow in real time. This study showed that the cholecystic venous flow spread to the liver through two different pathways, one that flowed directly into the hepatic parenchyma adjacent to the gallbladder, while the other flowed into sites separate from the gallbladder. Taking these findings into consideration, we may therefore need to reconsider the preventive effects of a hepatic resection.

Indocyanine green (ICG) fluorescence angiography is a new technique that help surgeons to assess the blood perfusion of the anastomotic intestine. The aim of this study is to evaluate whether ICG fluorescence angiography can reduce the anastomotic leakage (AL) rate after colorectal anastomoses for rectal cancer (RC) patients. Studies comparing AL rates between use and nonuse of ICG fluorescence angiography up to April 2020 were systematically searched from PubMed, Embase, Web of Science, Cochrane Library, and China National Knowledge Infrastructure. A pooled analysis was performed for the available data regarding the baseline features, AL rate, and other surgical outcomes. ReMan 5.3 software was used to perform the statistical analysis. Quality evaluation and publication bias were also conducted. Thirteen studies with a total of 2593 patients (1121 in the ICG group and 1472 in the control group) undergoing colorectal anastomoses after RC surgery were included. In the pooled analysis, the baseline data, operation time, and intraoperative blood loss in 2 groups were all comparable and without significant heterogeneity. However, the AL rate in the ICG group was significantly lower (OR .31; 95% CI .22-.44; P < .00001) than that in the control group. Additionally, ICG fluorescence angiography was associated with a decreased overall complication rate (OR .60; 95% CI .47-.76; P < .0001) in patients who undergo RC surgery. The present study revealed that ICG fluorescence angiography reduced AL rate after colorectal anastomoses for RC patients. However, more high-quality randomized controlled trials are needed to confirm this benefit.

The potential utility of intraoperative microscope-integrated indocyanine green (ICG) fluorescence angiography in the surgery of brain arteriovenous malformations (AVMs) and evaluation of the completeness of resection is debatable. Postoperative catheter angiography is considered the gold standard. We evaluated the value of ICG and intraoperative catheter angiography in this setting. Between January 2009 and July 2013, 37 patients with brain AVMs underwent surgical resection of their vascular lesions. ICG videoangiography and an intraoperative catheter angiography were performed in 32 cases, and a routine postoperative angiogram was performed within 48 h to 2 weeks after surgery. The usefulness of ICG findings and the ability to confirm total resection and to identify residual nidus or persistent shunt were assessed and compared to intraoperative and postoperative digital subtraction angiography, respectively. There were 7 grade 1, 11 grade 2, 11 grade 3 and 3 grade 4 Spetzler-Martin classification AVMs. ICG angiography helped to distinguish AVM vessels in 26 patients. In 31 patients, it demonstrated that there was no residual shunting. In one patient, a residual AVM was identified and further resected. Intraoperative catheter angiography detected two additional small residuals that were missed by ICG angiography, both deep in the surgical cavity. Further resection of the AVM was performed, and total resection was confirmed by a repeat intraoperative angiogram. Postoperative angiography in a patient with a grade 4 lesion revealed one additional small deep residual AVM nidus with persistent late shunting missed on both ICG and intraoperative angiography. Overall ICG angiography missed three out of four residual AVMs after initial resection, while the intraoperative angiogram missed one. Although ICG angiography is a helpful adjunct in the surgery of some brain AVMs, it's yield in detecting residual AVM nidus or shunt is low, especially for deep-seated lesions and higher grade AVMs. ICG angiography should not be used as a sole and/or reliable technique. High-resolution postoperative angiography must be performed in brain AVM surgery and remains the best test to confidently confirm complete AVM resection.

Intraoperative fluorescence angiography with indocyanine green to prevent anastomotic leak in rectal cancer surgery (IntAct): an unblinded randomised controlled trial.

Indocyanine green (ICG) fluorescence angiography has been introduced to assess parathyroid perfusion intraoperatively. This study aimed to evaluate whether the number of well-vascularized parathyroid glands identified using ICG fluorescence could predict the maintenance of adequate parathyroid hormone (PTH) levels in the immediate postoperative period. A retrospective study was conducted on 150 consecutive patients who underwent total thyroidectomy for papillary thyroid cancer between March 2021 and December 2023. Parathyroid perfusion was assessed using ICG fluorescence angiography, and glands were classified on a scale from 0 (no vascularization) to 2 (good vascularization). PTH levels were measured 1 h postoperatively, and biochemical hypoparathyroidism was defined as PTH < 15 pg/dL. Statistical analyses were performed using Fisher's exact test and Chi-square test, with p < 0.05 considered significant. Transient biochemical hypoparathyroidism occurred in 34.7% of patients. Among patients with two or more well-vascularized parathyroid glands (score 2), 70.2% did not experience a decrease in parathyroid hormone levels below 15 pg/mL (NPV 70.2%, 95% CI: 62.4-78.1%). However, 29.8% of patients with two or more well-vascularized glands still developed hypoparathyroidism, highlighting the limitations of using this metric alone to predict postoperative outcomes. The overall accuracy for predicting hypoparathyroidism was 70% (95% CI: 62.7-77.3%). No patient developed permanent hypoparathyroidism. ICG fluorescence angiography is a reliable tool for assessing parathyroid gland perfusion during thyroidectomy. However, the identification of two or more well-vascularized parathyroid glands does not completely exclude the risk of transient hypoparathyroidism, indicating that additional factors must be considered in predicting postoperative outcomes.

Indocyanine Green (ICG) fluorescence angiography of gastric conduit after transhiatal thoracic esophagectomy with proximal gastrectomy for esophagogastric junction adenocarcinoma: A case report and initial experience at a tertiary government hospital in the Philippines

Bone perfusion evaluation methods in cadaver studies have yet to be established. The aim of this report was to introduce and validate the feasibility of indocyanine green (ICG) fluorescence angiography for evaluation of bone perfusion in the femoral medial condyle in cadavers. In 4 fresh nonembalmed cadavers (2 female), the descending genicular artery was dissected and carefully cannulated bilaterally. A 10 mL solution containing 5 mL ICG solution and 5 mL methylene blue solution was injected into the descending genicular artery. After the injection, the medial femoral condyle was cut with an oscillating saw. A photograph was taken of the cut ends of the bone. The cut ends of the bones were observed using a near-infrared camera. Images corresponding to the previously taken photographs of the cut ends were captured for comparative analysis. After injection of methylene blue and ICG, the blue dye could be seen in the periosteum in all specimens, but not inside the cortex or the cancellous region of the bone. When observed with ICG fluorescence angiography, however, the cancellous region was highlighted through small perforators penetrating the periosteum. Perfusion inside the medial femoral condyle in cadavers was confirmed using ICG fluorescence angiography. Our method can be especially beneficial in confirming the bone perfusion of a new bone flap based on a particular artery, both in cadavers as well as in patients, because ICG can be injected into specific arteries.