Comparison of IMD and ICG videoangiography in combined bypass surgery: a single-center study.

BACKGROUND: Superficial temporal artery-middle cerebral artery (STA-MCA) bypass combined with an encephaloduromyosynangiosis (EDMS) had gained significant role in treating chronic cerebral ischemia. Invasiveness and costs of intraoperative digital subtraction angiography (DSA) limited its application in operations. OBJECTIVE: To find the reliable parameters for determining bypass patency with intraoperative micro-Doppler (IMD) sonography and compare the diagnostic accuracy of indocyanine green (ICG) videoangiography with IMD in combined bypass. METHOD: One hundred fifty bypass procedures were included and divided into patent and non-patent groups according to postoperative computed tomography angiography (CTA) within 72 h. The surgical process was divided into four phases in the following order: preparation phase (phase 1), anastomosis phase (phase 2), the temporalis muscle closure phase (phase 3), and the bone flap closure phase (phase 4). The IMD parameters were compared between patent and non-patent groups, and then compared with the patency on CTA by statistical analyses. IMD with CTA, ICG videoangiography with CTA, IMD with ICG videoangiography were performed to assess bypass patency. The agreement between methods was evaluated using kappa statistics. RESULTS: No significant differences of baseline characteristics were found between patent and non-patent group. Parameters in the STA were different between patent and non-patent groups in phases 2, 3, and 4. In patent group, Vm was apparently higher and PI was lower in phases 2, 3, and 4 compared with phase 1 (P < .001). In non-patent group, no differences of Vm and PI were found within inter-group. The best cutoff value of IMD in the STA to distinguish patent from non-patent bypasses was Vm in phase 4 > 17.5 cm/s (sensitivity 94.2%, specificity 100%). In addition, the agreement for accessing bypass patency was moderate between ICG videoangiography and CTA (kappa = 0.67), IMD and ICG videoangiography (kappa = 0.73), and good between IMD and CTA (kappa = 0.86). CONCLUSION: ICG videoangiography could directly display morphology changes of bypass. IMD could be used for providing half-quantitative parameters to assess bypass patency. Vm in phase 4 > 17.5 cm/s suggesting the patency of bypass on CTA would be good. Also, compared with ICG videoangiography, IMD had more accuracy.

How I do it? Basilar bifurcation and left anterior choroidal artery aneurysms clipping.

BACKGROUND: Despite advancements in endovascular techniques, microsurgical treatment for posterior circulation aneurysms remains challenging. METHOD: This report highlights the successful clipping surgery of a 17-year-old female patient with an aneurysm located at the basilar artery (BA) bifurcation and left anterior choroidal artery (AChoA). To improve exposure, the posterior communicating artery was transected. A straight fenestrated clip was then placed to repair the BA bifurcation aneurysm, followed by a curved mini clip for the AChoA aneurysm. CONCLUSION: This report demonstrates the nuances of microsurgery in the treatment of select complex cases, which can benefit from microsurgery to achieve optimal treatment outcomes.

The value of intraoperative indocyanine green angiography in microvascular decompression for hemifacial spasm to avoid brainstem ischemia.

PURPOSE: Despite being rarely reported, ischemic insults resulting from compromising small brainstem perforators following microvascular decompression (MVD) remain a potential devastating complication. To avoid this complication, we have been using indocyanine green (ICG) angiography intraoperatively to check the flow within the small brainstem perforators. We aim to evaluate the safety and usefulness of ICG videoangiography in MVD. METHODS: We extracted retrospective data of patients who received ICG videoangiography from our prospectively maintained database for microvascular decompression. We noted relevant data including demographics, offending vessels, operative technique, outcome, and complications. RESULTS: Out of the 438 patients, 15 patients with a mean age (SD) of 53 ± 10.5 years underwent intraoperative ICG angiography. Male:female was 1:1.14. The mean disease duration prior to surgery was 7.7 ± 5.3 years. The mean follow-up (SD) was 50.7 ± 42.0 months. In 14 patients, the offending vessel was an artery, and in one patient, a vein. Intraoperative readjustment of the Teflon pledget or sling was required in 20% (3/15) of the cases. No patient had any sort of brainstem ischemia. Eighty percent of the patients (12/15) experienced complete resolution of the spasms. 86.7% (13/15) of the patients reported a satisfactory outcome with marked improvement of the spasms. Three patients experienced slight hearing affection after surgery, which improved in two patients later. There was no facial or lower cranial nerve affection. CONCLUSION: Intraoperative ICG is a safe tool for evaluating the flow within the brain stem perforators and avoiding brainstem ischemia in MVD for hemifacial spasm.

How I do it: the surgical resection of a middle third parasagittal meningioma with venous preservation strategy.

BACKGROUND: The surgical resection of the middle third parasagittal meningioma (PSM) is difficult, where the challenge is to systematically protect the eloquent parenchyma and collateral venous drainage. METHOD: We report a case of PSM that eroded the skull, wholly occluded the superior sagittal sinus at the middle third segment, underwent radical resection with evaluation and preservation of the collateral venous drainage by preoperative venography, and intraoperative indocyanine green videoangiography (ICGVA) that aimed to avoid postoperative complications. CONCLUSION: This case demonstrates the importance of venous preservation strategy and the value of ICGVA in the intraoperative assessment of collateral venous drainage function.

Safety and completeness of using indocyanine green videoangiography combined with digital subtraction angiography for aneurysm surgery in a hybrid operating theater.

This study aimed to evaluate the safety and completeness of using intraoperative indocyanine green videoangiography (ICGV) combined with intraoperative angiography (IOA) for aneurysm clipping in a hybrid operating room (hOR). All patients who underwent microsurgical clipping in the hOR were identified from prospectively maintained neurosurgical databases. Medical charts and operative videos with ICGV and IOA were reviewed to determine the adequacy of clipping, and clinical and angiographic outcomes were retrospectively analyzed. Fifty-four cerebral aneurysms (ruptured, 31; unruptured, 23) in 50 patients (mean age, 59.4 ± 10.9 y; M:F, 22:28) were evaluated with ICGV and IOA during clipping. Additional IOA led to a clip adjustment during surgery in 9/54 (16.7%) aneurysms for which ICGV had been initially performed. Post-clip perforator compromise occurred in two (3.7%) cases, with a patient with an unruptured aneurysm experiencing permanent injury (grade 3 hemiparesis) and patient with a ruptured aneurysm experiencing transient deficit. Post-clip parent vessel stenosis occurred in one (1.9%) case; however, an ischemic event did not occur because the flow patency was identified by IOA. No other patients with unruptured aneurysms developed new neurologic deficits at discharge. Favorable outcomes (Glasgow Outcome Score [GOS], 4 or 5) were observed in 26/31 patients with ruptured aneurysms. Five patients had unfavorable outcomes (GOS, 2 or 3) from the initial insult. Post-treatment angiography within 1 week showed complete occlusion in 52 (96.3%) aneurysms and minor remnants in two (3.7%) aneurysms. Using combined ICGV and IOA in a hOR may improve the safety and completeness of microsurgical aneurysm clipping.

Application of the selective indocyanine green videoangiography in microsurgical treatment of a craniocervical junction dural arteriovenous fistula.

Craniocervical junction dural arteriovenous fistula (CCJDAVF) is a rare and unique type of intracranial DAVF with complex neurovascular anatomy, making it difficult to identify the arterialized vein during operation. The authors report the case of a 50-year-old male who presented with symptoms of venous hypertensive myelopathy. Angiography demonstrated a left CCJDAVF. The fistula was successfully disconnected via a suboccipital midline approach. The selective indocyanine green videoangiography (SICG-VA) technique was applied to distinguish the fistula site and arterialized vein from adjacent normal vessels. Favorable clinical and angiographic outcomes were attained. The detailed operative technique, surgical nuances, and utility of SICG-VA are illustrated in this video atlas.The video can be found here: https://youtu.be/GJYl_jOJQqU.

Multimodal use of indocyanine green endoscopy in neurosurgery: a single-center experience and review of the literature.

During the last 10 years, microscope-integrated indocyanine green fluorescence (m-ICG) has been widely used for assessing real-time blood flow during aneurysm surgery. More recently, an endoscope-integrated indocyanine green fluorescence (e-ICG) has been adopted as a versatile tool during different endoscopic neurosurgical procedures. The purpose of the present report is to evaluate multimodal applications of e-ICG during different endonasal, intraventricular, aneurysm and brain tumor surgeries and provide technical nuances. In addition, we reviewed the literature and identified and compare several overlapping case series of patients treated via an endoscopic integrated indocyanine green fluorescence technique. A total of 40 patients were retrospectively evaluated. Patients were divided into four main groups: (1) endoscopic endonasal approaches (n = 14); (2) ventricular endoscopic approach including patients undergoing third ventriculostomy (n = 8) and tumor biopsy (n = 1); (3) aneurysms surgery (n = 9); and (4) brain parenchymal tumors (n = 8). All patients were successfully treated using the e-ICG dynamic endoscopic visualization, and there were no perioperative complications. Such unique features open up a promising field of applications beyond the use of m-ICG in different surgical field due to the longer duration of e-ICG fluorescence up to 35 ± 7 min. E-ICG represents a new and effective technique for longer real-time visualization of vascular structures preserving normal tissues and functions during different transcranial and endonasal approaches. As the technology and e-ICG resolution improves, the technique has the potential to become a critical tool for different applications in neurosurgery.

Role of Indocyanine Green Videoangiography in Identification of Donor and Recipient Arteries in Cerebral Bypass Surgery.

The identification and preparation of a very good quality donor artery is a crucial step in every superficial temporal artery to middle cerebral artery (STA-MCA) bypass.For flow-preservation bypass performed for trapping of complex MCA aneurysms, the key element is the correct target of the recipient artery. When a cortical recipient artery (M4 segment of the MCA) is selected, this vessel must be a terminal branch of the artery whose sacrifice is necessary for definitive aneurysmal treatment.In this chapter we report on two techniques for (1) intraoperative mapping and preparation of good quality STA branch as the donor artery for STA-MCA bypass (mostly in the case the frontal branch of the STA needs to be used) and (2) selective identification of the correct superficial (M4 cortical) "recipient" artery in flow-preservation STA-MCA bypass performed for managing complex MCA aneurysms.Both techniques are based on the use of microscope-integrated indocyanine green videoangiography (ICG-VA), an intraoperative tool allowing observation and real-time assessment of blood flow in large and small vessels, with distinct evaluation of arterial, capillary, and venous phases.The two techniques contribute, respectively, to (1) reduce the risk of erroneous identification or injury of the donor artery in STA-MCA bypass procedures and (2) eliminate the risk of erroneous revascularization of a non-involved arterial territory in flow-preservation bypass surgery for managing complex MCA aneurysms.

Use of ICG videoangiography and FLOW 800 analysis to identify the patient-specific venous circulation and predict the effect of venous sacrifice: a retrospective study of 172 patients.

OBJECTIVE The best management of veins encountered during the neurosurgical approach is still a matter of debate. Even if venous sacrifice were to lead to devastating consequences, under certain circumstances, it might prove to be desirable, enlarging the surgical field or increasing the extent of resection in tumor surgery. In this study, the authors present a large series of patients with vascular or oncological entities, in which they used indocyanine green videoangiography (ICG-VA) with FLOW 800 analysis to study the patient-specific venous flow characteristics and the management workflow in cases in which a venous sacrifice was necessary. METHODS Between May 2011 and December 2017, 1972 patients were admitted to the authors' division for tumor and/or neurovascular surgery. They retrospectively reviewed all cases in which ICG-VA and FLOW 800 were used intraoperatively with a specific target in the venous angiographic phase or for the management of venous sacrifice, and whose surgical videos and FLOW 800 analysis were available. RESULTS A total of 296 ICG-VA and FLOW 800 studies were performed intraoperatively. In all cases, the venous structures were clearly identifiable and were described according to the flow direction and speed. The authors therefore defined different patterns of presentation: arterialized veins, thrombosed veins, fast-draining veins with anterograde flow, slow-draining veins with anterograde flow, and slow-draining veins with retrograde flow. In 16 cases we also performed a temporary clipping test to predict the effect of the venous sacrifice by the identification of potential collateral circulation. CONCLUSIONS ICG-VA and FLOW 800 analysis can provide complete and real-time intraoperative information regarding patient-specific venous drainage pattern and can guide the decision-making process regarding venous sacrifice, with a possible impact on reduction of surgical complications.

The role of indocyanine green videoangiography with FLOW 800 analysis for the surgical management of central nervous system tumors: an update.

OBJECTIVE Indocyanine green videoangiography (ICG-VA) is an intraoperative technique used to highlight vessels in neurovascular surgery. Its application in the study of the vascular pathophysiology in CNS tumors and its role in their surgical management are still rather limited. A recent innovation of ICG-VA (i.e., the FLOW 800 algorithm integrated in the surgical microscope) allows a semiquantitative evaluation of cerebral blood flow. The aim of this study was to evaluate for the first time the systematic application of ICG-VA and FLOW 800 analysis during surgical removal of CNS tumors. METHODS Between May 2011 and December 2017, all cases in which ICG-VA and FLOW 800 analysis were used at least one time before, during, or after the tumor resection, and in which surgical videos were available, were retrospectively reviewed. Results of the histological analysis were analyzed together with the intraoperative ICG-VA with FLOW 800 in order to investigate the tumor-related videoangiographic features. RESULTS Seventy-one patients who underwent surgery for cerebral and spinal tumors were intraoperatively analyzed using ICG-VA with FLOW 800, either before or after tumor resection, for a total of 93 videoangiographic studies. The histological diagnosis was meningioma in 25 cases, glioma in 14, metastasis in 7, pineal region tumor in 5, hemangioblastoma in 4, chordoma in 3, and other histological types in 13 cases. The authors identified 4 possible applications of ICG-VA and FLOW 800 in CNS tumor surgery: extradural surveys allowed exploration of sinus patency and the course of veins before dural opening; preresection surveys helped in identifying pathological vascularization (arteriovenous fistulas and neo-angiogenesis) and regional venous outflow, and in performing temporary venous clipping tests, when necessary; postresection surveys were conducted to evaluate arterial and venous patency and parenchymal perfusion after tumor removal; and a premyelotomy survey was conducted in intramedullary tumors to highlight the posterior median sulcus. CONCLUSIONS The authors found ICG-VA with FLOW 800 to be a useful method to monitor blood flow in the exposed vessels and parenchyma during microsurgical removal of CNS tumors in selected cases. In particular, a preresection survey provides useful information about pathophysiological changes of brain vasculature related to the tumor and aids in the individuation of helpful landmarks for the surgical approach, and the postresection survey helps to prevent potential complications associated with the resection (such as local hypoperfusion or venous infarction).

Trapping and resection of cortical MCA mycotic aneurysm in eloquent area.

BACKGROUND: Mycotic aneurysms, although well recognized, are relatively rare intracranial vascular pathology. These aneurysms are typically located in distal cortical vessels. When these aneurysms are located in eloquent cerebral territories, they may become challenging to treat. Eloquent location may necessitate intraoperative angiographic evaluation to verify complete aneurysmal occlusion/obliteration and preservation of normal adjacent vasculture. Recently, ICG videoangiography has become a widely used intra-operative adjunct and is an important tool used to assess complete occlusion and vessel patency at the conclusion of clip reconstruction. In this report, we outline the comprehensive and concurrent utilization of both vascular imaging modalities to ensure safe and complete occlusion of a mycotic aneurysm. METHODS: We describe our experience with a patient with left M4, Rolandic, enlarging mycotic aneurysm that was treated in a comprehensive fashion with microsurgery and intra-operative angiography (IA). CONCLUSIONS: ICG videoangiography, in combination with concurrent intraoperative angiography in the setting of complex vascular lesions, may support intraoperative decision-making and provide demonstration of complete occlusion in an immediate fashion. A hybrid operative suite allows for high-quality imaging confirming complete resection.

Repair of damaged cortical artery by direct micro-suture in surgical treatment of acute subdural hematoma: technical note.

BACKGROUND: In surgical treatment of acute subdural hematoma (ASDH), neurosurgeons frequently encounter bleeding from cortical arteries, which is usually controlled with bipolar coagulation. However, bipolar coagulation is associated with a risk of sacrificing the cortical artery, which may affect the prognosis of neurological symptoms when these cortical arteries supply critical areas. In this article, we describe microsurgical repair of damaged cortical arteries using a 10-0 nylon micro-suture in patients with arterial-origin ASDH. METHODS: After removal of the subdural hematoma, the exact bleeding point of the cortical artery was identified, and the 10-0 nylon suture stitches were placed on the arterial tear under a microscope. After completion of the micro-suture, vascular patency was confirmed by indocyanine green (ICG) videoangiography. RESULTS: From June 2015 through February 2017, microsurgical repair was performed for seven cortical arteries in six patients. All damaged arteries were located near the Sylvian fissure, and all tears were pinhole tears. The average blood flow occlusion time was 8 min (range, 0-15 min). The patency of all seven repaired arteries was successfully confirmed by ICG videoangiography. Postoperative cerebral infarction was not observed except in one patient with cerebral contusion and a history of severe head trauma. CONCLUSIONS: The present report demonstrates that repair of a cortical artery by the 10-0 nylon micro-suture is a simple and safe method with a low risk of sacrificing the artery. This technique may be a good option in the surgical treatment of arterial-origin ASDH, especially when the accompanying cerebral contusion is minimal.

Utility of indocyanine green videoangiography in subcortical arteriovenous malformation resection.

Subcortical arteriovenous malformations (AVMs) are surgically challenging. Localization is crucial for eloquent areas, and complete resection evaluation is uncertain. Indocyanine green videoangiography (ICG-VA) can assist this surgery. An illustrative video of a subcortical frontoparietal bleeding AVM resection assisted by ICG-VA is presented. A bleeding arterial feeder aneurysm was embolized in the acute phase to protect against rebleeding. ICG-VA helped to detect the AVM's superficial arterialized draining vein, distinguishing it from normal cortical veins. This enabled a customized sulcus approach. ICG-VA showed normalized flow through the previously arterialized vein, confirming the AVM's complete resection. This applies when there is a single drainage remaining. The video can be found here: https://youtu.be/L7yJEE66kV0 .

Partial wrap-clipping of the entrance of the pseudolumen of a fusiform aneurysm in the posterior inferior cerebellar artery: a technical note.

BACKGROUND: Fusiform aneurysms in the posterior inferior cerebellar artery (PICA) are rare and challenging to treat. Surgical treatment options for a fusiform aneurysm in the PICA include trapping with/without bypass and wrap-clipping, when elimination of the pathological wall from the systemic circulation and prevention of perforator injury are important. In addition, lower cranial nerve impairment due to surgical manipulation should also be avoided. METHOD: A fusiform-shaped aneurysm was found in a proximal part of the PICA by magnetic resonance angiography undertaken for evaluation of repeated vertigo in a 36-year-old man. The patient underwent direct surgery via a lateral suboccipital transcondylar fossa approach. The entrance of the pseudolumen was the only part to be wrapped and obstructed by clip application, through the corridor between the acoustic and glossopharyngeal nerves to avoid lower cranial nerve injury. RESULTS: Indocyanine green (ICG) videoangiography demonstrated obliteration of pseudolumen and patency of peripheral PICA and perforator contributing to the medulla oblongata. The postoperative course was uneventful without periprocedural complications, including dysphagia and hoarseness. CONCLUSIONS: Partial wrap-clipping technique for obstruction of the entrance into a pseudolumen is one of alternatives for dissecting fusiform-shaped aneurysm in the PICA. ICG videoangiography was helpful to confirm the obliteration of the pseudolumen and patency of parent vessel and perforators.

Early retreatment after surgical clipping of ruptured intracranial aneurysms.

BACKGROUND: Although a rerupture after surgical clipping of ruptured intracranial aneurysms is rare, it is associated with high morbidity and mortality. The causes for retreatment and rupture after surgical clipping are not clearly defined. METHODS: From a prospectively maintained database of 244 patients who had undergone surgical clipping of ruptured intracranial aneurysms, we selected patients who experienced retreatment or rerupture within 30 days after surgical clipping. Aneurysm occlusions were examined by microvascular Doppler ultrasonography and indocyanine green video-angiography. Indications for retreatment included rerupture and partial occlusion. We analyzed the characteristics and causes of early retreatment. RESULTS: Six patients (2.5%, 95% CI 0.9 to 5.3%) were retreated within 30 days after surgical clipping, including two patients (0.8%, 95% CI 0.1 to 2.9%) who experienced a rerupture. The retreated aneurysms were found in the anterior communicating artery (AcomA) (n = 5) and basilar artery (n = 1). Retreatment of the AcomA (7.5%) was performed significantly more frequently than that of other arteries (0.56%) (p < 0.01). A laterally projected AcomA aneurysm (17.4%) was more frequently retreated than were other aneurysm types (2.3%). Cases of laterally projecting AcomA aneurysms tended to result from an incomplete clip placed using a pterional approach from the opposite side of the aneurysm projection. CONCLUSIONS: Despite developments, the rates of retreatment and rerupture after surgical clipping remain similar to those reported previously. Retreatment of the AcomA was significantly more frequent than was retreatment of other arteries. Patients underwent retreatment more frequently when they were originally treated for lateral type aneurysms using a pterional approach from the opposite side of the aneurysm projection. The treatment method and evaluation modalities should be considered carefully for AcomA aneurysms in particular.

Multimodal Flow-Assisted Resection of Brain AVMs.

OBJECT: The authors report their personal experience with brain arterio-venous malformations (bAVMs) surgery with a multimodal flow-assisted approach. METHODS: Data from patients who consecutively underwent bAVM resection with the assistance of indocyanine green video-angiography (ICG-VA), micro-flow probe flowmetry, and temporary arterial clipping test under intra-operative monitoring, were retrospectively analyzed. RESULTS: Twenty seven patients were enrolled in the study. Re-operation for residual nidus was needed in one case (3 %). Average mRS change 1 month after surgery was +0.02. In our experience, the multimodal flow-assisted approach enabled surgeons to shift from one technique to another, according to the stage of resection, AVM location, or specific issues to be addressed. Before resection, the value of ICG-VA and flowmetry in showing AVM angio-architecture and guiding surgical strategy was related to AVM features. The temporary arterial clipping-test presented a 100 % sensitivity to differentiate between an AVM feeder and a transit artery to the sensi-motor area. At the final stage of resection, flowmetry was more effective than ICG-VA in detecting residual nidus missed at dissection. CONCLUSIONS: Multimodal flow-assisted approach in AVM surgery proved a feasible, safe, and reliable methodology to achieve AVM resection with high radicality and low morbidity rate.

Indocyanine green videoangiography for the identification of superficial temporal artery branches in EC-IC bypass surgery.

BACKGROUND: Superficial temporal artery-to-middle cerebral artery (STA-MCA) bypass remains an essential tool for managing complex cerebrovascular conditions. A crucial surgical step is the identification and safe dissection of the bypass donor artery. If the frontal branch of the STA is used, a curvilinear fronto-temporal scalp flap generally allows for a clean dissection from the underside of the scalp flap. This dissection is sometimes tedious, since the frontal branch is not always easily visible and due to variability of its anatomy. With this article, we report on the feasibility and effectiveness of a simple indocyanine green videoangiography (ICG-VA)-assisted technique for the identification of the STA branches from the underside of a fronto-temporal scalp flap in bypass surgery. METHODS: The technique is based on the analysis of the difference in timing of filling of scalp vessels illuminated via ICG-VA from the underside of a scalp flap. Three illustrative cases are reported. RESULTS: ICG-VA permitted the correct identification and safe dissection of the donor vessels (STA branches) in all three patients. There were no complications due to the ICG-VA. CONCLUSIONS: This technique allows reliable visualization of the STA and its branches at once before microsurgical dissection. The information provided by ICG-VA enables precise mapping and preparation of the STA. The simplicity and safety of this technique make it an effective tool for intraoperative identification of the STA and its branches.

Complete removal of a cavernous malformation in the dorsal pons, in contact with the expanded transpontine vein: illustrative case.

BACKGROUND: Craniotomy is required for the removal of brainstem cavernous malformations (CMs) with repeated hemorrhage, and this condition is often complicated by an accompanying developmental venous anomaly (DVA). However, a DVA of the brainstem or cerebellum with drainage penetrating the pons is an exceptional finding. OBSERVATIONS: A 57-year-old man presented with double vision. Computed tomography revealed progressive enlargement of the hemorrhage in the dorsal pons. Contrast-enhanced magnetic resonance angiography revealed an expanded transverse vessel penetrating the center of the pons in contact with the CM. Digital subtraction angiography revealed that the DVA, comprising the expanded transpontine vein and some cerebellar medullary veins acting as normal venous drainage, coexisted with the CM. By utilizing the angioarchitecture and intraoperative neuronavigation system data, electrophysiological mapping, and indocyanine green videoangiography, complete removal of the CM was accomplished while preserving the DVA and brain function. LESSONS: This study presents the intraoperative images of an expanded transpontine vein as a DVA, which has never been depicted in a live patient before, accompanied by a CM in the dorsal portion of the pons. https://thejns.org/doi/10.3171/CASE24314.

Preoperative Angiographic Protocol for the Surgical Management of Spinal Dural Arteriovenous Fistulas: A Technical Nuance for Safe Minimally Invasive Surgery.

BACKGROUND: Interruption of the fistulous point is the goal of treatment of spinal dural arteriovenous fistulas (dAVFs). Microsurgery remains a highly efficient treatment in terms of complete occlusion with the lowest risk of recurrence rate. It is reported that the hardest step involves finding the fistulous site itself, potentially extending surgical access and time and increasing potential postoperative surgical-related complications. The accurate preoperative detection of the shunt and spinal level together is crucial for guiding optimal, fast, and safe microsurgical treatment. METHODS: We describe a preoperative angiographic protocol for achieving a safe and simple resection of spinal dural arteriovenous fistulas based on a 6-year institutional experience of 42 patients who underwent minimally invasive procedures. Two illustrative cases are included to support the technical descriptions. RESULTS: The suspected artery associated with the vascular malformation of interest is studied in our angiographic protocol through nonsubtracted selective acquisitions in lateral projection. The resulting frames are reconstructed with three-dimensional rotational angiography. The implementation of the preoperative angiographic protocol allowed 100% of intraoperative identification of the fistulous point in all cases with the use of a minimally invasive approach. CONCLUSIONS: Nowadays, neurosurgeons advocate for minimally invasive procedures and procedures with low morbidity risk for treatment of spinal dural arteriovenous fistulas. Our preoperative approach for accurate angiographic localization of the fistulous point through nonsubtracted and three-dimensional reconstructed angiography allowed us to achieve safe and definitive occlusion of the shunt.

Cost-Effectiveness of Forgoing Postoperative Catheter Angiography After Microsurgical Occlusion of Spinal Dorsal Intradural Arteriovenous Fistulas.

OBJECTIVE: Spinal dorsal intradural arteriovenous fistulas (DI-AVFs) represent 70% of all spinal vascular lesions. Diagnostic tools include pre- and postoperative digital subtraction angiography (DSA) and intraoperative indocyanine green videoangiography (ICG-VA). ICG-VA has a high predictive value in DI-AVF occlusion, but postoperative DSA remains a core component of postoperative protocols. The aim of this study was to evaluate the potential cost reduction of forgoing postoperative DSA after microsurgical occlusion of DI-AVFs. METHODS: Cohort-based cost effectiveness study of all DI-AVFs within a prospective, single-center cerebrovascular registry from January 1, 2017, to December 31, 2021. RESULTS: Complete data including intraoperative ICG-VA and costs were available for 11 patients. Mean (SD) age was 61.5 (14.8) years. All DI-AVFs were treated with microsurgical clip ligation of the draining vein. ICG-VA showed complete obliteration in all patients. Postoperative DSA was performed for 6 patients and confirmed complete obliteration. Mean (SD) cost contributions for DSA and ICG-VA were $11,418 ($4,861) and $12 ($2), respectively. Mean (SD) total costs were $63,543 ($15,742) and $53,369 ($27,609) for patients who did and did not undergo postoperative DSA, respectively. Comorbidity status was identified as the main driver of total cost (P = 0.01 after adjusting for postoperative DSA status). CONCLUSIONS: ICG-VA is a powerful diagnostic tool in demonstrating microsurgical cure of DI-AVFs, with a negative predictive value of 100%. Eliminating postoperative DSA in patients with confirmed DI-AVF obliteration on ICG-VA may yield substantial cost savings, in addition to sparing patients the risk and inconvenience of a potentially unnecessary invasive procedure.