R Dodd’s research while affiliated with Stanford University and other places

( Reg Anesth Pain Med . 2024;49:293–297. doi:10.1136/rapm-2023-105197) Unintended dural puncture (UDP) is a possible complication of epidural catheter placement, which can cause acute postdural puncture headache (PDPH). The resulting cerebrospinal fluid (CSF) leak can heal without treatment, but the third most common cause of lawsuits against anesthesiologists by obstetric patients was headache (HA), showing that the impact of these symptoms is not benign and can be long-term. This article is a case report focused on a patient with UDP that reported persistent severe symptoms despite treatment with epidural blood patch (EBP) triggering further investigation and the confirmation of a persistent ventral dural puncture.

Background Postdural puncture headache has been traditionally viewed as benign, self-limited, and highly responsive to epidural blood patching (EBP) when needed. A growing body of data from patients experiencing unintended dural puncture (UDP) in the setting of attempted labor epidural placement suggests a minority of patients will have more severe and persistent symptoms. However, the mechanisms accounting for the failure of EBP following dural puncture remain obscure. An understanding of these potential mechanisms is critical to guide management decisions in the face of severe and persistent cerebrospinal fluid (CSF) leak. Case presentation We report the case of a peripartum patient who developed a severe and persistent CSF leak unresponsive to multiple EBPs following a UDP during epidural catheter placement for labor analgesia. Lumbar MRI revealed a ventral rather than dorsal epidural fluid collection suggesting that the needle had crossed the thecal sac and punctured the ventral dura, creating a puncture site not readily accessible to blood injected in the dorsal epidural space. The location of this persistent ventral dural defect was confirmed with digital subtraction myelography, permitting a transdural surgical exploration and repair of the ventral dura with resolution of the severe intracranial hypotension. Conclusions A ventral rather than dorsal dural puncture is one mechanism that may contribute to both severe and persistent spinal CSF leak with resulting intracranial hypotension following a UDP.

Introduction Micro-arteriovenous malformations (microAVMs) are a subtype of cerebral AVM characterized by an arterial nidus less than 1 cm in diameter. Due to their small size, these lesions may be difficult to identify on conventional MRI. They can also be missed or occult on cerebral angiography. Arterial spin labeling (ASL) is an MRI sequence which acts as a surrogate marker for arterial perfusion and which may be useful in the identification of small arterial lesions such as microAVMs. Materials and Methods We conducted a retrospective cohort study of 34 microAVMs in 19 patients, diagnosed at a single academic medical center from 1996 to 2020. Inclusion criteria were presence of microAVM confirmed by either cerebral angiogram or surgery. Patients without ASL-MRI were excluded. An electronic medical record was queried for patient demographics, diagnostic work-up, results of ASL-MRI, and surgical pathology when available. Two experienced neuroradiologists counted the number and location of lesions seen on ASL-MRI in a blinded fashion. Cohen’s kappa was calculated for inter-rater reliability. Results 22 patients with microAVMs were initially selected. 3 patients were excluded due to lack of ASL imaging. 12 males and 7 females were included with a total of 34 microAVMs. Mean patient age was 39.8 years (SD ± 19.0 years). Among 34 microAVMs, 27 lesions had positive findings on ASL (79.4%). Inter-rater agreement was substantial (Cohen’s kappa = 0.70) with raters agreeing in 88.6% of cases. 9 patients were initially diagnosed with one or more microAVMs due to the presence of positive ASL signal (47.4%). 3 patients with ASL findings suggestive of a microAVM had angiographically occult lesions which were confirmed at the time of surgery (15.8%). • Download figure • Open in new tab • Download powerpoint Abstract O-023 Figure 1 Conclusion ASL assists in the identification of cerebral microAVMs. This sequence can be used to suggest an initial diagnosis of microAVM. It can also identify angiographically occult microAVMs confirmed at the time of surgical excision. Disclosures V. Mayercik None. R. Taiwo None. M. Marks None. R. Dodd None. J. Heit None. H. Do None. N. Telischak None.

Introduction The vasa vasorum are small vessels in the adventitial and medial layers of larger vessels which nourish their walls. When large vessels are occluded, the vasa vasorum may reconstitute them. We hypothesize that their hypertrophy is associated with a hypoplastic or aplastic circulus arteriosus which may be unable to meet the ischemic demands of the tissue perfused by the occluded vessel. Materials and Methods We conducted a retrospective cohort study of patients with occlusion of the internal carotid artery and reconstitution of the vessel by vasa vasorum as confirmed by cerebral angiography. An electronic medical record was queried for patient demographics. The presence and caliber of an anterior communicating artery (AComm)and a posterior communicating artery (PComm) on the ipsilateral side of the lesion were measured by two experienced neurointerventionalists. Results We reported 11 cases in 11 patients. Patients were predominantly female (n=7) and older (mean age 63.7 years, SD 15.6 years). 100% of patients had either an aplastic or hypoplastic circulus arteriosus. 81.8% of patients had either an aplastic AComm or ipsilateral PComm. When these vessels were present, 63.6% were hypoplastic with a mean diameter of 0.85 mm (SD ± 0.34 mm) and 0.82 mm (SD ± 0.22 mm), respectively. • Download figure • Open in new tab • Download powerpoint Abstract E-032 Figure 1 Conclusion Reconstitution of an occluded internal carotid artery by the vasa vasorum is associated with an aplastic or hypoplastic circulus arteriosus, which may fail to compensate for the ischemic demand of the tissue initially perfused by the occluded vessel. Disclosures V. Mayercik None. M. Marks None. R. Dodd None. J. Heit None. H. Do None. N. Telischak None.

Introduction Anterior cranial fossa dural arteriovenous fistulas (dAVFs) represent up to 10% of all dAVFs and have traditionally been treated surgically. These lesions derive their arterial supply from the bilateral anterior ethmoidal arteries (ophthalmic artery branches) in nearly all cases. Embolization via the ophthalmic artery poses unique technical challenges due to its small caliber and risk of vision loss. To date, there is a paucity of literature regarding the safety and efficacy of performing endovascular embolizations via the ophthalmic artery. Advances in endovascular therapy, including highly trackable microcatheters and balloon microcatheters, offer the potential for safe and successful embolization via the ophthalmic artery. Here we describe our experience of anterior cranial fossa dAVF treatment by endovascular embolization via the ophthalmic artery. Materials and Methods We conducted a retrospective cohort study of consecutive patients with anterior cranial fossa dAVF treated by ophthalmic artery embolization at two neurovascular centers from 2012 to 2020. Primary outcome was angiographic cure of the dAVF. Secondary outcome measures included vision loss, modified Rankin Scale at 90-days, mortality, and any other iatrogenic treatment complications. Results 10 patients met inclusion criteria, which included 8 male and 2 females. Mean patient age was 61.9 (SD 8.0) years. DAVF Cognard grades were: II (1 patient), III (5 patients), and IV (4 patients). 4 patients presented with cerebral hemorrhage due to the dAVF. 6 patients presented with headache, aphasia, amaurosis fugax, or were asymptomatic and incidentally discovered. The most commonly embolized arterial feeding vessels were the anterior and posterior ethmoidal arteries (n=8) and the recurrent meningeal artery (n=2). Embolysates included Onyx (8 cases), nBCA glue (1 case), and a combination of coils and Onyx (1 case). 4 cases were performed with balloon microcatheters. Complete dAVF cure was achieved in 9 patients (90%). Two patients had delayed washout of the ophthalmic artery after embolization which was treated with aspirin without subsequent visual defect. No patients experienced vision loss, death, or permanent disability. One patient experienced a minor complication of blurry vision in the left hemi-field suggestive of posterior ischemic optic neuropathy. 90 day mRS was 0 (7 patients), 1 (2 patients), and not yet available for one patient. Conclusions Anterior cranial fossa dAVF embolization can be safely performed through the ophthalmic artery with high angiographic cure rates and a low risk of vision loss or other complications. Disclosures V. Mayercik None. N. Telischak None. E. Sussman None. B. Pulli None. R. Dodd None. M. Marks None. H. Do None. J. Heit None.

Introduction Recent landmark randomized clinical trials have demonstrated that endovascular thrombectomy (EVT) leads to improved outcomes in patients with acute ischemic stroke (AIS) due to large vessel occlusion (LVO). Although elderly patients were excluded from several of these initial trials, the available data suggests a benefit of EVT in octogenarian patients with AIS due to LVO. However, the efficacy of EVT in the nonagenarian patient population remains uncertain. Methods We performed a retrospective cohort study of a prospectively-maintained stroke database at a single comprehensive stroke center. Inclusion criteria were: age 80–99 years, LVO, core infarct <70mL on perfusion imaging, and presence of a salvageable penumbra. Patients were stratified based on age into octogenarian (age 80–89) and nonagenarian (age 90–99) cohorts. Primary outcome was ordinal score on the modified Rankin Scale (mRS) at 90 days. Secondary outcomes included dichotomized functional outcome (mRS≤2 versus mRS≥3), successful revascularization, symptomatic reperfusion hemorrhage and mortality. Results 108 patients met inclusion criteria, including 79 octogenarians (73%) and 29 nonagenarians (27%). Mean octogenarian age was 84.2 years (SD 2.8) versus 92 years (SD 2.3) in nonagenarians. Nonagenarians were more likely to be female (86% versus 58%; p<0.01); there were no other differences between the groups in terms of demographics, medical comorbidities, pre-treatment clinical variables, or endovascular treatment characteristics. Median mRS at 90 days was 5 (IQR 3–6) in octogenarians and 6 (IQR 4–6) in nonagenarians (p=0.09). Independent functional status (mRS≤2) at 90 days was achieved in 13% of nonagenarians and in 20% of octogenarians (p=0.54). Successful revascularization (TICI 2b-3) was achieved in 79% in both the octogenarian and nonagenarian cohorts (p=1). Symptomatic reperfusion hemorrhage occurred in 21% of nonagenarians and in 6% of octogenarians (p=0.03). The 90-day mortality rate was 63% in nonagenarians versus 41% in octogenarians (p=0.07). Conclusions Nonagenarian patients undergoing EVT for AIS due to LVO are at significantly higher risk of symptomatic reperfusion hemorrhage compared with octogenarians, despite similar stroke- and treatment-related factors. While there was a strong trend towards higher mortality rates and worse long-term functional outcomes in nonagenarians, the difference was not statistically significant in this relatively small retrospective study. Additional prospective and randomized studies are necessary to evaluate the efficacy of EVT in elderly patients, including nonagenarians. Disclosures E. Sussman None. B. Martin None. M. Mlynash None. M. Marks None. D. Marcellus None. G. Albers None. M. Lansberg None. R. Dodd None. H. Do None. J. Heit None.

Introduction/purpose MRI offers potential benefits over CT in selection for endovascular stroke thrombectomy. Despite this, only one-fourth of patients in the recently published DAWN and Defuse-3 trials were selected with MRI. Often, the major concern with MR utilization involves possibility of delayed treatment given the time associated with acquisition. Moreover, many patients being evaluated for acute ischemic stroke treatment will already have CT with CTA and possibly CTP and it is unclear whether additional information gleaned from an MR would change management. We present our single center experience in utilization of MRI for acute stroke. Materials and methods We retrospectively reviewed all stroke interventional radiology (SIR) activations at Stanford from February 2017 to February 2018. We assessed our breakdown of preprocedure imaging selection, the amount of time associated with obtaining imaging (looking at the arrival time to hospital, time of first image acquisition, and time to entering the angiography suite for each case). We paid particular attention to cases where patients had an outside CT and received an MR upon arrival to Stanford to see how often the MR acquisition changed management. We then selected a few representative cases for discussion. Results We identified 193 patients from February 2017 to February 2018 to be included in this study. In keeping with our practice pattern, the vast majority of cases (almost 85%) were through interfacility transfers from outside hospitals. Only a minority of our cases came through our institution’s emergency department. Almost all patients coming through interfacility transfers had CT and CTA prior to transfer.Patients who underwent mechanical thrombectomy who had preprocedure MRIs did not experience delay in treatment. Door to first image time did not vary between CT and MR as expected. The average time from first image acquisition to cath lab arrival time also did not differ significantly (27 min with MRI versus 21 with CT/CTA/CTP). Approximately 38% of cases underwent endovascular treatment. Moreover, in cases where outside CT, CTA and/or CTP were available, MR at our institution often was helpful assessing for size of core infarct (which not infrequently hanged from time of initial outside CT imaging acquisition), provided better assessment of collaterals over CTA, and thereby frequently influenced management. Conclusion MRI offers advantages over CT in endovascular stroke therapy selection, particularly with regards to assessing size of core infarction (which does not infrequently change from the time a transfer is called to the time a patient arrives at a comprehensive stroke center) and determining collateral status. MRI selection also does not necessarily confer a delay in treatment if key stroke systems of care are in place. Disclosures A. Patel None. U. Manzoor None. A. Iyer None. H. Do None. M. Wintermark None. M. Marks None. R. Dodd None.

Introduction Endovascular therapy of acute ischemic stroke is the standard of care, but controversy exists regarding how the size of the pre-treatment infarction and patient age should influence patient selection for endovascular treatment. Magnetic resonance imaging (MRI) with diffusion-weighted imaging (DWI) or computed tomography perfusion (CTP) can estimate the pre-treatment infarct volume (core). Studies have examined the interplay between core and patient age, however to date sufficient data do not exist to guide decision making in octogenarians with stroke. We undertook this study to examine the influence of infarct core and age on clinical outcome. Methods Patients treated between July 2008 and September 2011 from a previously reported study (DEFUSE2) and all patients treated at our institution between September 2012 and June 2015 who underwent endovascular therapy for anterior circulation stroke using available devices were included. Patient demographic data, stroke risk factors, and treatment details were recorded. Core infarct volumes were determined with either DWI MRI or CBF CTP. The primary outcome was good functional outcome of modified Rankin score 0–2 at 90 days; a secondary measure was TICI 2 B/3 reperfusion. ROC analysis was performed for lesion size and age to determine values above which there was <10% chance of a good clinical outcome. Results 154 patients (mean 69 years (SD 14), 85 (55%) female) met inclusion criteria and had clinical follow-up. Forty-two (27%) were ≥ 80 years. Median time to imaging was 4.5 hours (IQR 2.9–6.7). 136 patients had pre-treatment MRI and 18 had CTP. TICI 2 B/3 reperfusion was achieved in 91 patients (59%). In univariate analysis, TICI 2 B/3 reperfusion (p 45 ml core and TICI 2 b/3 had a good outcome (p = 0.030). This threshold remained an independent predictor when adjusted for age, NIHSS and TICI 2 B/3 reperfusion (OR = 6.7, 95% CI 1.2–36). In ROC analysis for age, 80 years showed a core of ≤16 mL yielded positive predictive value of 10% or better for a good outcome, but the differences in the rates of good outcome at this threshold were not significant. Conclusion This study found TICI 2 B/3 reperfusion, core volume, age, and baseline NIHSS were independent predictors for good outcome. ROC analysis demonstrated a core infarct volume of 80 years the ROC analysis demonstrated that a core infarct volume of <16 ml had a PPV of 10% or better of yielding a good outcome, suggesting that older patients tolerate a smaller core. However, the current study was underpowered to identify the significance of this threshold. Disclosures N. Telischak: None. A. Faisal: None. J. Wong: None. A. Moraff: None. H. Do: None. R. Dodd: None. J. Heit: None. M. Mlynash: None. M. Lansberg: None. G. Albers: None. M. Marks: None.

Introduction Reperfusion to TICI 2 B/3 with stent retrievers has significantly improved when compared with intravenous tPA in several recent randomized controlled trials. However, at least 20% of patients did not achieve this degree of reperfusion. In prior studies, recanalization rates with tPA and early-generation thrombectomy devices (e.g. MERCI) correlated with erythrocyte-rich clots represented by hyperdense MCA (HDMCA) on CT or blooming artifact (BA) on susceptibility-weighted MRI. We hypothesize that clot characteristics, such as clot length, and the presence of HDMCA or BA, may influence the rate of full (TICI 3) reperfusion and the number of passes to achieve reperfusion with stent retrievers. Methods We retrospectively identified all patients with anterior circulation strokes treated with stent retrievers between January 2015 and March 2016 from our institutional stroke database. All patients underwent a pre-procedural CT or MRI, and revascularization using combined mechanical and aspiration thrombectomy (Solumbra) technique. Patient demographics, risk factors, stroke presentation data, and endovascular treatment details (equipment, number of thrombectomy passes, final TICI reperfusion score, and complications) were recorded. Recorded clot characteristics included the presence of HDMCA and BA on CT and MRI, clot length and Hounsfield Unit density on CT or clot signal intensity on susceptibility-weighted MRI compared to corresponding contralateral artery. Primary outcomes of full reperfusion (TICI 3) and corresponding number of passes were correlated with clot characteristics. Univariate and multivariate analyzes were performed to identify any significant associations. Results Sixty-four patients with anterior circulation proximal vessel occlusion were treated using stent retrievers. There were 23 (36%) females with a mean age of 73 ± 14 years (Range 28–92 years). Median NIHSS on presentation was 14 (IQR 10–19). Vessel occlusion was localized to the ICA terminus (10 patients, 16%), M1 (41 patients, 64%) and M2 (13 patients, 20%) segments. Intravenous tPA was administered in 44 patients (69%). TICI 2 B/3 reperfusion was achieved in 57 patients (89%) and TICI 3 in 27 (42%). Among HDMCA patients, TICI 3 rate was 50% (vs 36% without HDMCA, p = 0.71); 47% with BA (vs 23% without, p = 0.27); and 49% with HDMCA or BA (vs 29% without, p = 0.13). No statistical difference was detected between the TICI 3 score and other clot characteristics (clot length, absolute and relative clot density or signal intensity). TICI 3 was significantly associated with single pass revascularization (74% vs 41%, p = 0.008), and time from access to revascularization (30 vs 54 minutes, p = 0.004). Longer clot length on CT correlated to a greater number of passes (Spearman’s rho = 0.7, p = 0.001) and longer time from access to revascularization (rho = 0.47, p = 0.036). Conclusion A greater percentage of patients with HMDCA or BA will have full (TICI 3) reperfusion compared to patients without HDMCA or BA, however this study was underpowered to demonstrate these differences were significant. Longer clot length is correlated with a greater number of passes and longer time to revascularization. Disclosures J. Wong None. M. Mlynash None. N. Telischak None. A. Moraff None. H. Do None. R. Dodd None. J. Heit None. M. Marks None.

Introduction High flow vascular lesions of the anterior cranial fossa and orbit (HFVL) include arteriovenous malformations and dural arteriovenous fistulae located within the orbit, periorbital region, ethmoid sinuses, the anteroinferior frontal lobes, or within the dura of the anterior cranial fossa. Rupture of HFVL may result in intracranial hemorrhage, so these lesions typically undergo treatment even when discovered for other reasons. HFVL may be treated by trans-arterial endovascular embolization, surgical ligation, radiosurgery, or a combination of these approaches, but the most optimal treatment is not well defined. We determined patient outcomes and HFVL obliteration after treatment. Methods We retrospectively reviewed all patients referred for diagnostic angiography or endovascular embolization of HFVL at our neurovascular referral center over an 8 year period. Patient demographic, treatment, and outcome data were deterred from the medical record. DSA, CT, and MRI studies were reviewed for HFVL characteristics and obliteration after treatment. Results HFVL were identified in 11 patients (five females and six males) ranging in age from 8 to 76 years (mean 53 years). Presenting symptoms included headaches (nine patients; 82%), visual symptoms (five patients; 45%), intracranial hemorrhage (two patients; 18%), tinnitus (one patient; 9%), or no symptoms (one patient; 9%). Nine patients (81%) had medical comorbidities, but none had a hypercoagulable disorder or prior trauma. The HFVL were comprised of seven dural arteriovenous fistulae (64%) and four arteriovenous malformations (36%). The ophthalmic artery was the dominant feeding vessel in 10 patients (91%). 10 patients (91%) were treated, including embolization via the ophthalmic artery (four patients; 36%), embolization followed by surgical ligation (3 patients; 27%), embolization followed by radiosurgery (one patient; 9%), surgical ligation alone (one patient; 9%), or radiosurgery alone (one patient; 9%). Endovascular embolization was performed with Onyx (six patients; 75%) or n-BCA (two patients; 25%) HFVL cure was achieved in six patients (55%), including three patients treated by embolization alone, two treated by embolization and surgical ligation, and one by surgery alone. One patient treated by embolization alone developed a post-treatment partial visual deficit, but there were no other complications related to treatment. No patient deaths occurred. Conclusions HFVL are uncommon lesions that are challenging to treat. Endovascular embolization alone or in combination with surgery results in HFVL obliteration in 50% of patients with an acceptable safety profile. Further studies should determine whether radiosurgery alone or in combination with endovascular embolization results in high rates of HFVL cure. ![Abstract E-008 Figure 1][1] Abstract E-008 Figure 1 Disclosures A. Moraff: None. R. Dodd: None. M. Marks: None. H. Do: None. G. Steinberg: None. S. Chang: None. J. Heit: None. [1]: pending:yes