[Topographic study of the parietal region for the elaboration of revascularized cranium vault autograft]. / Izuchenie topografo-anatomicheskikh osobennostei temennoi oblasti pri razrabotke revaskulyariziruemogo kostno-fastsial'nogo temennogo autotransplantata.

OBJECTIVE: Topographic and blood vessel architecture study of the parietal area and distal regional pool of the superficial temporal artery (STA) to assess the possibility of revascularized cranium vault bone autograft formation. MATERIAL AND METHODS: For the topographic and anatomical study, 30 non-fixed corpses (17 male and 13 female) were selected, the average age of which was 59±5 years. In the anamnesis and catamnesis, there were no indications of trauma or other pathology of the head and neck, including vascular. STA was contrasted with a non-radiocontrast dye (brilliant green) with the introduction of the dye into the STA with preliminary ligation of the frontal branch of the STA. The area of blood supply to soft tissue and bone structures was studied. The angioarchitectonics of the parietal region was studied, the feeding vessel of the studied flap was identified. RESULTS: The obtained anatomical landmarks for the collection of CPFP flap make it possible to form a flap with high accuracy and minimize the morbidity of the donor area.

Scalp necrosis following preoperative endovascular embolisation of the superficial temporal artery for meningioma.

A woman in her late 50s with a left frontal lobe convexity meningioma underwent an elective endovascular embolisation of the left middle meningeal artery and distal branches of the left superficial temporal artery prior to surgical resection of the tumour. On postoperative day 46, she developed scalp necrosis, leading to poor wound healing requiring wound debridement and a complex plastic surgery reconstruction with a rotational flap. Endovascular embolisation of vascular tumours prior to surgical resection does not come without risks. The lack of consistency in the literature regarding indication, technique and outcomes makes it difficult to define the exact role of preoperative meningioma embolisation.

Surgical Treatment of Spontaneous Superficial Temporal Artery Arteriovenous Malformation: A Case Report.

BACKGROUND An arteriovenous malformation (AVM) is an abnormal connection between an artery and a vein, bypassing the capillary network. An AVM of the superficial temporal artery (STA) can occur after trauma, iatrogenic injury, infection, or spontaneously. Spontaneous, or iatrogenic, presentations of STA AVM are thought to be rare, with very few reported cases. Symptoms include local pain, headache, tinnitus, or paresthesia, in addition to a palpable mass associated with thrill on palpation. Options for diagnosis include intra-arterial angiography, doppler ultrasound, magnetic resonance angiography (MRA), and computed tomography angiography (CTA). Current management options include surgical excision, ligation, and embolization; however, it is unknown which treatment is superior in terms of recurrence and which carries a lower risk of complications. CASE REPORT We present a case of a spontaneous STA AVM in a 76-year-old woman with past medical history significant for seasonal allergies and hyperlipidemia, who presented with pulsatile tinnitus and a palpable, tender mass located to the left temporal area. The mass had been present for several years, with gradual increase in size two to three years prior to presentation. She denied any history of trauma or procedure prior to presentation of the pulsatile mass. She underwent open excision with complete resolution of symptoms and no recurrence at 11-month follow-up. CONCLUSIONS AVM of the STA is a condition that can occur secondary to trauma, infection, iatrogenic injury, or spontaneously. Spontaneous, or iatrogenic, presentations of STA AVM are thought to be rare, with very few cases documented in the literature. Surgical treatment remains the standard of management, with options including surgical excision, ligation, or embolization.

Development of the external carotid artery system including the middle temporal artery after direct-indirect revascularization surgery for moyamoya disease.

BACKGROUND: The aim of this study was to clarify when and from which blood vessels indirect revascularization develops after combined revascularization surgery for moyamoya disease and how the donor vessels that undergo direct revascularization change in the medium to long term. In particular, we focused on the middle temporal artery (MTA), which has not received much attention in indirect revascularization surgery for moyamoya disease until now. METHODS: We targeted 20 sides that were suitable for evaluating the diameter of the external carotid artery system involved in combined revascularization surgery among moyamoya disease patients who underwent a composite revascularization procedure utilizing a 'U'-shaped skin incision encircling the parietal branch of the superficial temporal artery (STA) at our institution from 2018 to 2023. We identified the STA parietal branch, MMA, DTA, and MTA in the TOF source MR images acquired preoperatively and three and six months after surgery; measured the long and short diameters of each blood vessel; approximated the blood vessel shape as an ellipse, and calculated its cross-sectional area. RESULTS: The cross-sectional areas of the MMA, DTA, and MTA involved in indirect revascularization significantly increased compared to presurgery three months after surgery, and this trend continued six months after surgery, but no significant change was observed between three and six months after surgery. There were no cases in which the MTA was clearly confirmed before surgery in the TOF reconstructed images, but the MTA was clearly confirmed in 55% (11/20 cases) of hemispheres three months after surgery and in 85% (17/20 cases) of hemispheres six months after surgery. The crosssectional area of the STA parietal branch, which was the donor for direct revascularization, had increased by more than 150% compared to before surgery in 55% (11/20 cases) of hemispheres three months after surgery. CONCLUSIONS: Indirect revascularization can be expected three months after combined revascularization surgery for moyamoya disease. The MTA, which has not received much attention in terms of indirect revascularization for moyamoya disease patients thus far, was found to be a useful blood flow source for indirect revascularization in combined revascularization surgery for patients with moyamoya disease. Whether or not the cross-sectional area of the superficial temporal artery used as a donor for direct revascularization increased in the medium to long term varied on a case-by-case basis.

Angiographic measurement of the superficial temporal artery for potential use in cerebral bypass surgery: a combined radiological and cadaveric study.

PURPOSE: This study aims to investigate the microsurgical anatomy of the superficial temporal artery (STA), explore the relationship between STA length and lumen diameter, and develop a reliable radiologic method for selecting STA segments for bypass surgery. METHODS: This study used 10 cadaveric dissections (20 STAs, both sides) and 20 retrospective radiological examinations (40 STAs, both sides), employing curved multiplanar reformation and flow color lookup table (CLUT) DICOM processing. Measurements included vessel lumen diameters and luminal cross-sectional thicknesses 3 mm proximal to the STA bifurcation, 3 mm distal to the frontal branch, 5 cm distal to the frontal branch, 3 mm distal to the parietal branch, and 5 cm distal to the parietal branch. The distance between the STA bifurcation and the superior zygomatic border (SZB) was also measured. In our analysis, descriptive statistics encompassed mean, standard deviation (SD), standard error, minimum and maximum values, and distributions. Comparative statistics were performed using Student's t-test, with statistical significance set at p < 0.05. RESULTS: There were no statistically significant differences between STA measurements of bifurcation distances (p = 0.88) and lumen diameters (p = 0.46) between cadavers and radiological measures. However, lumen thicknesses were larger in frontal branches than parietal branches at the seventh and eighth centimeter (p = 0.012, p = 0.039). Branches became thinner distally from the zygoma in both cadavers and radiological image measurements. CONCLUSION: The CLUT DICOM processing radiological measures provided the high-precision required to enable pre-surgical vessel selection for extracranial-intracranial bypass. The results show that STA vessel luminal diameters are sufficient (> 1 mm) for bypass surgery in the first 9 cm but gradually decrease after that. Also shown is that the choice of frontal versus parietal branches depends on individual anatomical features; therefore, careful preoperative radiological examination is critical.

Anatomical variant of the superficial temporal artery in temporoparietal fascia flap for microtia reconstruction.

BACKGROUND: Single-stage microtia auricular reconstruction is becoming more relevant. The determining factor is a temporoparietal fascia flap (TPF) with both branches of the superficial temporal artery (STA). There are not many studies regarding vascular branching in people with microtia. METHODS: We conducted an anatomical study on the TPF flap harvested during single-stage endoscopic-assisted microtia auricular reconstruction from May 2018 to July 2021. We observed the flaps under endoscopic and surgical microscopes to determine several variables (vascular size, number of frontal/parietal branches, distance from the branching location to the estimated external ear canal, distance from the frontal artery to projected course of facial nerve's frontal branch, etc.). RESULTS: The study included 55 flaps from 54 patients. Of the 55 flaps, 50 (90.9%) had a parietal branch, and all 55 (100%) had a frontal branch with a mean diameter of 0.98 and 0.91 mm, respectively. Regarding the frontal artery, 1.8%, 25.5%, 50.9%, 16.35% and 5.45% had 0-4 traverse frontal branch(es), respectively. The mean distance from the frontal artery to the estimated course of the frontal nerve was 10.56 mm. Parietal artery absence is more likely in patients with severe hemifacial microsomia or STA trunk go under the auricular cartilage remnants (p < 0.05). Either frontal or parietal artery absence or small diameter can cause necrosis. Frontal arteries travelling near the frontal nerve may result in post-operative nerve palsy. CONCLUSIONS: Microtia auricular reconstructive surgery is always a big challenge for plastic surgeons. Anatomical variants are common. A detailed anatomical description of the STA, with the help of microsurgery and endoscopy, allows arterial-based flap designing and harvest, which tremendously improves surgical success rate by diminishing flap necrosis and nerve damage. CLINICAL QUESTION/LEVEL OF EVIDENCE: Therapeutic, IV.

Superficial Temporal Artery Posterior Branch Flap for Reconstruction of Composite Oral/Perioral Defects.

PURPOSE: Defects involving total lower and/or upper lip often extend to intraoral and/or perioral areas. Flaps based on superficial temporal artery, either as pedicled or free flaps, can be used for reconstruction of various head and neck defects. In this clinical study, we tried to demonstrate the application of a pedicled flap based on the posterior branch of superficial temporal artery in 3-dimensional reconstruction of these composite oral/perioral defects as a successful alternative in cases where microvascular tissue transfer cannot be performed. PATIENTS AND METHODS: Six male patients with composite perioral/oral defects who underwent reconstruction with a pedicled flap based on the posterior branch of the superficial temporal artery between April 2020 and December 2020 were evaluated retrospectively. Demographic data, topographic data of defects, and the dimensions of the flaps were gathered from patient files. All patients required reconstruction after tumor resection. RESULTS: All flaps survived without any signs of partial or total necrosis. Postoperatively, the patients did not report any oral incompetence or drooling, and they were able to fully close their mouths. CONCLUSIONS: Pedicled flaps based on the posterior branch of superficial temporal artery provide reliable results in composite perioral/oral reconstruction.

Usefulness of STA ultrasonography parameters after STA-MCA bypass in patients with moyamoya disease: A short review.

STA bypass assessment by ultrasonography after bypass surgery in patients with moyamoya disease is minimally invasive and can be performed repeatedly. With STA bypass assessment by ultrasonography, it was shown that in the short term, blood flow that passes through the STA peaks approximately 5 days after the bypass surgery and then gradually decreases over 7 days. In the medium and long terms, it has been shown that the blood flow through the bypass decreases, compared with that during the first postoperative week, and continues for approximately half a year. The ultrasonographic STA parameters can also clearly indicate bypass patency, but there remains some discussion regarding bypass function. Although some reports have tried to show that these parameters are also useful for predicting acute-phase TNEs and predicting the future of bypass function, no studies have yet examined these parameters in detail in relation to the state of cerebral circulation or degree of residual antegrade flow, and additional studies are needed in the future.

The clinical outcome of emergency superficial temporal artery-to-middle cerebral artery bypass in acute ischemic stroke with large vessel occlusion.

The role of superficial temporal artery-to-middle cerebral artery (STA-MCA) bypass in acute ischemic stroke (AIS) is contentious, with no evidence in patients with AIS and large vessel occlusion (AIS-LVO). We conducted a cohort study to assess emergency STA-MCA outcomes in AIS-LVO and a meta-analysis to evaluate STA-MCA outcomes in early AIS treatment. From January 2018 to March 2021, we consecutively recruited newly diagnosed AIS-LVO patients, dividing them into STA-MCA and non-STA-MCA groups. To evaluate the neurological status and outcomes, we employed the National Institutes of Health Stroke Scale (NIHSS) during the acute phase and the modified Rankin Scale (mRS) during the follow-up period. Additionally, we conducted a meta-analysis encompassing all available clinical studies to assess the impact of STA-MCA on patients with AIS. In the cohort study (56 patients), we observed more significant neurological improvement in the STA-MCA group at two weeks (p = 0.030). However, there was no difference in the clinical outcomes between the two groups. Multivariable logistic regression identified the NIHSS at two weeks (OR: 0.840; 95% CI: 0.754-0.936, p = 0.002) as the most critical predictor of a good outcome. Our meta-analysis of seven studies indicated a 67% rate for achieving a good outcome (mRS < 3) at follow-up points (95% CI: 57%-77%, I2 = 44.1%). In summary, while the meta-analysis suggested the potential role of STA-MCA bypass in mild to moderate AIS, our single-center cohort study indicated that STA-MCA bypass does not seem to improve the prognosis of patients who suffer from AIS-LVO.

The Early Postoperative Course of Cognitive Function and Preoperative Cerebrovascular Reserve.

BACKGROUND: Patients with severe steno-occlusive disease of a main cerebral artery without causative lesions on magnetic resonance imaging (MRI) often develop cognitive impairment. However, the effects of revascularization surgery and the source of the cognitive impairment remain unclear. Therefore, we investigated the early postoperative course of cognitive function and its association with cerebral blood flow (CBF), cerebrovascular reserve (CVR), white matter disease (WMD), lacunar infarction, and cerebrovascular risk factors. METHODS: Cognitive function was examined using neurobehavioral cognitive status examination (COGNISTAT) in 52 patients with steno-occlusive disease of a main cerebral artery before and at 6 months after superficial temporal artery-middle cerebral artery (STA-MCA) anastomosis. We examined how cognition changed before and at 1, 3, and 6 months after STA-MCA anastomosis in 27 of 52 patients. CVR and CBF were calculated from 123I-N-isopropyl-p-iodoamphetamine single photon emission computed tomography, in addition to other cerebrovascular risk factors in 34 of 52 patients. Cerebral infarction and WMD (periventricular hyperintensity [PVH] and deep subcortical white matter hyperintensity) were also evaluated preoperatively by MRI. RESULTS: COGNISTAT scores improved at 1 month after STA-MCA anastomosis in patients with severe steno-occlusive disease of a main cerebral artery. Multiple stepwise regression analysis revealed that CVR (regression coefficient = -2.237, p = 0.0020) and PVH (regression coefficient = 2.364, p = 0.0029) were the best predictors of postoperative improvement in COGNISTAT scores (R 2 = 0.415; p = 0.0017). CONCLUSION: Cognitive function improves in relation to preoperative CVR and PVH early after STA-MCA anastomosis in patients with steno-occlusive disease of a main cerebral artery.

Arterial Bypass in the Treatment of Complex Middle Cerebral Artery Aneurysms: Lessons Learned from Forty Patients.

OBJECTIVE: Complex middle cerebral artery (MCA) aneurysms incorporating parent or branching vessels are often not amenable to standard microsurgical clipping or endovascular embolization treatments. We aim to discuss the treatment of such aneurysms via a combination of surgical revascularization and aneurysm exclusion based on our institutional experience. METHODS: Thirty-four patients with complex MCA aneurysms were treated with bypass and aneurysm occlusion, 5 with surgical clipping or wrapping only, and 1 with aneurysm excision and primary reanastomosis. Bypasses included superficial temporal artery (STA)-MCA, double-barrel STA-MCA, occipital artery-MCA, and external carotid artery-MCA. After bypass, aneurysms were treated by surgical clipping, Hunterian ligation, trapping, or coil embolization. RESULTS: The average age at diagnosis was 46 years. Of the aneurysms, 67% were large and most involved the MCA bifurcation. Most bypasses performed were STA-MCA bypasses, 12 of which were double-barrel. There were 2 wound-healing complications. All but 2 of the aneurysms treated showed complete occlusion at the last follow-up. There were 3 hemorrhagic complications, 3 graft thromboses, and 4 ischemic insults. The mean follow-up was 73 months. Of patients, 83% reported stable or improved symptoms from presentation and 73% reported a functional status (Glasgow Outcome Scale score 4 or 5) at the latest available follow-up. CONCLUSIONS: Cerebral revascularization by bypass followed by aneurysm or parent artery occlusion is an effective treatment option for complex MCA aneurysms that cannot be safely treated by standard microsurgical or endovascular techniques. Double-barrel bypass consisting of 2 STA branches to 2 MCA branches yields adequate flow replacement in most cases.

Optimizing the Approach to STA-MCA Bypass Surgery and Reducing Wound Complications.

BACKGROUND AND OBJECTIVES: The treatment of complex intracranial aneurysms with bypass surgery using 2 branches of the superficial temporal artery (STA) proves to be an effective surgical option. However, the harvest of these 2 STA branches, combined with a pterional craniotomy, carries the potential risk of delayed wound healing of the skin flap. This study undertook a retrospective analysis to examine and identify the factors associated with this delayed wound healing. METHODS: A total of 56 consecutive cases, including both ruptured and unruptured complex intracranial aneurysms, that underwent bypass surgery with 2 branches of the STA, were analyzed retrospectively. RESULTS: Major delayed wound healing was observed in 6 (10.7%) cases. Univariate analysis demonstrated significant associations with the following factors: rupture (P = 0.023), presence of diabetes mellitus (P = 0.028), large craniotomy size (P = 0.012), and the type of skin incision (P ≤ 0.001). Age (P = 0.283), sex (P = 0.558), body mass index (P = 0.221), and other blood test parameters did not demonstrate any statistical significance. Similarly, the presence of a dominant frontal branch (P = 0.515) or a low-positioned frontal branch (P = 0.622) did not reveal statistically significant results. CONCLUSIONS: In the treatment of complex intracranial aneurysms, where harvesting of the 2 STA branches is involved with a pterional craniotomy, producing a smaller skin flap (L- or T-shaped incision) is effective in minimizing the risk of delayed wound healing. The process of harvesting the STA and closing the wound demands meticulous care, taking into consideration the normal anatomical structures and the subdermal vascular plexus of the scalp.

Superficial temporal artery interposition bypass for the treatment of complex intracranial aneurysms: Flexible and creative options for flow preservation bypass.

PURPOSE: Flow-preservation bypass is a treatment option for complex intracranial aneurysms (IAs) that cannot be managed with microsurgical clipping or endovascular treatment. Various bypass methods are available, including interposition grafts such as the radial artery or saphenous vein. Size discrepancy, invasiveness, and procedure complexity must be considered when using interposition grafts. We describe our experience of treating complex IAs using a superficial temporal artery (STA) interposition bypass. METHODS: We retrospectively reviewed the medical records and operative videos of all patients who were treated for complex IAs at our center from January 2009 to December 2021 using cerebral revascularization. Clinical, radiological, and surgical findings of the cases that underwent STA interposition bypass were investigated. RESULTS: Seventy-six bypass procedures were performed of which seven (9.2%) complex IAs were managed using STA interposition bypass. Of these 5 cases were of anterior cerebral artery, 1 of middle cerebral artery, and 1 of posterior inferior cerebellar artery aneurysm. There were no postoperative ischemic complications. Revision surgery for postoperative pseudomeningocele was performed in one case. The long-term bypass patency rate was 85.7% (6 out of 7) and good long-term aneurysm control was achieved in all cases, with a mean follow-up of 64 months. CONCLUSIONS: When treating complex IAs, creative revascularization strategies are needed in selective cases for favorable outcomes. STA interposition graft bypass which can reduce the size discrepancy between the donor and recipient may be a less invasive, flexible, and practical option for treating complex IAs.

[Application of indocyanine green angiography in repair of facial soft tissue defect using superficial temporal artery based forehead flap].

Objective: To explore the feasibility of using indocyanine green angiography in mapping the superficial temporal vessels and assisting design and harvesting of the superficial temporal artery based forehead flap. Methods: A clinical data of 14 patients with facial soft tissue defects repaired with superficial temporal artery based forehead flaps between October 2015 and November 2022 was retrospectively analyzed. There were 9 males and 5 females with a median age of 9.5 years (range, 3-38 years). The forehead flaps were used to reconstruct facial soft tissue defects following excision of facial scar (8 cases) or congenital melanocyte nevus (6 cases). The size of defects ranged from 3 cm×2 cm to 24 cm×9 cm. Before operation, the indocyanine green angiography was used to map the superficial temporal artery and vein, and to analyze the relationship of the arteries and veins. The forehead flaps with unilateral superficial temporal fascia as the pedicle was transferred to repair the small facial defect in 2 cases. The facial pedicle contained the frontal branch of the superficial temporal artery and 2 cm of the superficial temporal fascia around the vessel, and the tiny accompanying vein of the frontal branch of the superficial temporal artery was used as the outflow of the flap. The forehead flaps with the skin pedicle including bilateral or unilateral superficial temporal fascia and the overlying skin was pre-expanded and transferred to repair the large facial defect in 12 cases. The skin pedicle contained the frontal branch of superficial temporal artery and one of main branches of superficial temporal vein. Among the 12 cases, the frontal branch of superficial temporal vein was used as the outflow in 4 cases, and the parietal branch was used as the outflow in 8 cases. The size of the flaps ranged from 3 cm×2 cm to 30 cm×13 cm. The skin pedicles were divided at 3 weeks after the flap transfer. Results: Indocyanine green angiography could clearly showed the course and branching of the superficial temporal artery and vein. Individual differences existed in the location where the frontal branch of the superficial temporal artery entered the forehead. The superficial temporal vein had great variability and did not follow the artery. One patient had expander-related complication, which resulted in 3-cm flap necrosis. The necrotic tissue was debrided and repaired with skin grafting. The other flaps totally survived and the incisions healed by first intention. All patients were followed up 2-24 months, with a median of 11.5 months. The color, texture, and thickness of the flaps matched well with those of recipient sites. Hypertrophic scar was not observed in recipient or donor site. All patients were satisfied with the reconstructive outcomes. Conclusion: Indocyanine green angiography can clearly visualize the course and the branches of the superficial temporal arteries and veins, which can help surgeons understand the position, distribution, and concomitant relationship of the superficial temporal vessels, and make a rational surgical plan of the forehead flap.

[Clinical effects of superficial temporal artery lobulated perforator flaps in repairing skin and soft tissue defects after temporal tumor resection].

Objective: To explore the feasibility and clinical effects of using superficial temporal artery lobulated perforator flaps in repairing skin and soft tissue defects after tumor resection in the temporal region. Methods: A retrospective observational study method was used. From March 2017 to October 2022, ten patients with temporal skin tumors were admitted to the Affiliated Hospital of Zunyi Medical University, including six women and four men, with age ranging from 42 to 87 years. Among them, three patients had squamous cell carcinoma and seven patients had basal cell carcinoma, with disease duration ranging from 6 months to 5 years. All temporal tumors underwent expanded resection, leaving wound areas of 5.4 cm×4.2 cm to 7.0 cm×4.0 cm after tumor resection. Superficial temporal artery frontal branch flaps with areas of 5.5 cm×1.2 cm to 7.0 cm×1.5 cm, superficial temporal artery descending branch flaps with areas of 4.2 cm×3.5 cm to 5.0 cm×4.0 cm, and superficial temporal artery parietal branch flaps with areas of 4.2 cm×1.0 cm to 5.0 cm×1.0 cm were designed to repair the wounds and reconstruct the hairline. The donor areas of the flaps were closed and sutured directly. The survival of the flaps was observed on 3 to 5 days after surgery, and the healing of wounds on the donor and recipient sites was observed when the stitches were removed on 5 to 7 days after surgery. During follow-up after surgery, the appearance of the temporal area, scar hyperplasia, hairline reconstruction, and tumor recurrence were observed in the temporal region on the affected side. Results: All the flaps survived well on 3 to 5 days after surgery, and all the donor and recipient site wounds healed well on 5 to 7 days after surgery. During follow-up of 3 to 6 months after surgery, the surgical incisions were concealed; the flaps were not swollen, with a consistent color to the surrounding skin; there were no obvious hypertrophic scars; the reconstructed hairline on the affected side was not significantly different from that of the healthy side; there was no tumor recurrence in the local area. Conclusions: For large areas of skin and soft tissue defects in the temporal region, the use of superficial temporal artery lobulated perforator flaps can repair the wounds in different regions and suture the donor sites in the primary stage simultaneously. The surgical operation is simple, and the facial appearance conforms to the aesthetic requirement after surgery with no tumor recurrence in the local area but a good repair effect. This method is particularly suitable for repairing large areas of skin and soft tissue defects in the temporal region in elderly patients.

Flow volume mismatch dramatically affects transient neurologic symptoms after direct bypass in Moyamoya disease.

Transient neurological events (TNEs) occur after bypass surgery in Moyamoya disease (MMD); however, their pathology remains unknown. To elucidate the pathophysiology of TNEs, we investigated their relationship with perioperative superficial temporal artery (STA) blood flow volume, which was evaluated using ultrasonography. Forty-nine patients with MMD, who underwent direct bypass surgery, were included and stratified into TNE and non-TNE groups, respectively. The STA blood flow volume was evaluated at four time points (preoperatively and 2-4, 7, and 10-14 days postoperatively), and a change in volume during the postoperative period was defined as a flow volume mismatch. We investigated the association between ultrasonographic findings of flow volume mismatch and TNEs and magnetic resonance imaging findings, such as the cortical hyperintensity belt (CHB) sign, using univariate and path analyses. The STA blood flow volume increased immediately postoperatively, gradually decreasing over time, in both groups. The TNE group showed a significant increase in blood flow volume 2-4 days postoperatively (P = 0.042). Flow volume mismatch was significantly larger in the TNE group than in the non-TNE group (P = 0.020). In the path analysis, STA flow volume mismatch showed a positive association with the CHB sign (P = 0.023) and TNEs (P = 0.000). Additionally, the CHB sign partially mediated the association between STA flow volume mismatch and TNEs. These results suggest that significantly high STA blood flow volume changes occurring during the acute postoperative period after direct bypass surgery in MMD are correlated with TNEs and the CHB sign, suggesting involvement in the pathophysiology of TNEs.

The value of indocyanine green-FLOW800 in microvasculature for predicting cerebral hyperperfusion syndrome in moyamoya disease patients.

Among the notable complications of direct hemodynamic reconstruction for moyamoya disease (MMD) is cerebral hyperperfusion syndrome (CHS). In this study, we evaluated hemodynamic changes in small regional microvasculature (SRMV) around the anastomosis site by using indocyanine green (ICG)-FLOW800 video angiography and verified that it better predicted the onset of CHS. Intraoperative ICG-FLOW800 analysis was performed on 31 patients (36 cerebral hemispheres) with MMD who underwent superficial temporal artery-middle cerebral artery (MCA) bypass grafting at our institution. The regions of interest were established in the SRMV and thicker MCA around the anastomosis. Calculations were made for half-peak to time (TTP1/2), cerebral blood volume (CBV), and cerebral blood flow (CBF). According to the presence or absence of CHS after surgery, CHS and non-CHS groups of patients were separated. The results showed that ΔCBV and ΔCBF were substantially greater in SRMV than in MCA (p < 0.001). Compared with the non-CHS group, ΔCBF and ΔCBV of SRMV and MCA were considerably greater in the CHS group (p < 0.001). ΔCBF and ΔCBV on the ROC curve for both SRMV and MCA had high sensitivity and specificity (SRMV: ΔCBF, AUC = 0.8586; ΔCBV, AUC = 0.8158. MCA: ΔCBF, AUC = 0.7993; ΔCBV, AUC = 0.8684). ICG-FLOW800 video angiography verified the differential hemodynamic changes in the peri-anastomotic MCA and SRMV before and after bypass surgery in patients with MMD.

Effects of superficial temporal artery to middle cerebral artery (STA-MCA) anastomosis on the cerebrospinal fluid gas tensions and pH in hemodynamically compromised patients.

PURPOSE: This study was aimed to directly measure cerebrospinal fluid (CSF) gas tensions and pH before and after STA-MCA anastomosis for occlusive carotid artery diseases to investigate its direct effects on the ischemic brain. METHODS: This study included 9 patients who underwent STA-MCA anastomosis on the basis of CBF studies. About 1 mL of CSF was collected before and after bypass procedures, and CSF pH, CSF PO2, and CSF PCO2 were measured with a blood gas analyzer. As the controls, the CSF was collected from 6 patients during surgery for unruptured cerebral aneurysm. CSF PO2 and CSF PCO2 were expressed as the ratio to PaO2 and PaCO2, respectively. RESULTS: Before bypass procedure, CSF PO2/PaO2 was 0.88 ± 0.16, being lower than the controls (1.10 ± 0.09; P = 0.005). CSF PCO2/PaCO2 was 0.93 ± 0.13, being higher than the controls (0.84 ± 0.06; P = 0.039). Ipsilateral-to-contralateral CBF ratio had a positive correlation with CSF PO2/PaO2 (P = 0.0028) but a negative correlation with the CSF PCO2/PaCO2 (P = 0.0045). STA-MCA anastomosis increased CSF pH from 7.402 ± 0.133 to 7.504 ± 0.126 (P = 0.0011) and CSF PO2/PaO2 from 0.88 ± 0.16 to 1.05 ± 0.26 (P = 0.018) but decreased CSF PCO2/PaCO2 from 0.93 ± 0.13 to 0.70 ± 0.17 (P = 0.0006). CONCLUSION: The severity of cerebral ischemia before surgery is intensely reflected in the gas tensions and pH of the CSF. STA-MCA anastomosis carries dramatic effects on CSF gas tensions and pH in hemodynamically compromised patients. CSF would be a valuable surrogate biomarker to monitor the severity of cerebral ischemia.