Presence Of Deep Venous Drainage Research Articles

Influence of preoperative embolisation on resection of brain arteriovenous malformations: cohort study

PurposePreoperative endovascular embolisation is a widely used adjunct for the surgical treatment of brain arteriovenous malformations (AVMs). However, whether this improves completeness of AVM resection is unknown, as previous analyses have not adjusted for potential confounding factors. We aimed to determine if preoperative endovascular embolisation was associated with increased rate of complete AVM resection at first surgery, following adjustment for Spetzler-Martin grade items.MethodsWe identified a cohort of all patients undergoing first ever AVM resection in a specialist neurosciences unit in the NHS Lothian Health Board region of Scotland between June 2004 and June 2022. Data was prospectively extracted from medical records. Our primary outcome was completeness of AVM resection. We determined the odds of complete AVM resection using binomial logistic regression with adjustment for Spetzler-Martin grading system items: maximum nidus diameter, eloquence of adjacent brain and the presence of deep venous drainage.Results88 patients (median age 40y [IQR 19–53], 55% male) underwent AVM resection. 34/88 (39%) patients underwent preoperative embolisation and complete resection was achieved at first surgery in 74/88 (84%). Preoperative embolisation was associated with increased adjusted odds of complete AVM resection (adjusted odds ratio [aOR] 8.6 [95% confidence interval (95% CI) 1.7–67.7]; p = 0.017). The presence of deep venous drainage was associated with reduced chance of complete AVM resection (aOR 0.18 [95% CI 0.04–0.63]; p = 0.009).ConclusionsPreoperative embolisation is associated with improved chances of complete AVM resection following adjustment for Spetzler-Martin grade, and should therefore be considered when planning surgical resection of AVMs.

Surgery in Intracerebral Arteriovenous Malformations: The Role of Preoperative Embolization.

The optimal treatment of cerebral arteriovenous malformations (AVMs) is still debated. Microsurgery and endovascular embolization can be utilized separately and in combination. However, each of these modalities harbor their own risks. In this study, we compared the outcomes of microsurgery only versus combined microsurgery+embolization approach in the treatment of AVMs. A total of 62 patients (34 men, 28 women) were recruited harboring Spetzler&Martin Grade-3 (n=44) and Grade-4 (n=18) AVMs. Among these, 37 were treated with combined microsurgery+embolization and 25 were treated with microsurgery alone. Their clinical features (ruptured/unruptured, eloquency, Modifed Rankin Scores, duration of surgery, pre- and post-op hemoglobin levels, usage of blood products) were compared. Higher number of patients with ruptured or eloquently-localized AVMs was treated with the combined approach. Duration of surgeries, pre- versus postoperative hemoglobin levels and usage of blood products did not differ between combined approach versus microsurgery alone. As eloquently located AVMs may possess higher surgical risks due to the presence of deep venous drainage or nidus size, combined treatment was more preferred. Other differences regarding selection of combined versus single approach were not associated with the lesion anatomo-physiology. Rather, we thought combined therapy was more appropriate in our initial clinical practice and planned our clinical strategy accordingly. Nonetheless, now, we found no superiority of the combined treatment in management of AVMs in parallel to recent meta-analyses. Hence, embolization before surgery is not generally advisable in the treatment of AVMs, yet some exceptions shall be considered in a patient-tailored approach.

Does Endovascular Treatment with Curative Intention Have Benefits for Treating High-Grade Arteriovenous Malformation versus Radiosurgery? Efficacy, Safety, and Cost-Effectiveness Analysis

The treatment of high-grade arteriovenous malformations (AVMs) remains challenging. Microsurgery provides a rapid and complete occlusion compared with other options but is associated with undesirable morbidity and mortality. The aim of this study was to compare the occlusion rates, incidence of unfavorable outcomes, and cost-effectiveness of embolization and stereotactic radiosurgery (SRS) as a curative treatment for high-grade AVMs. A retrospective series of 57 consecutive patients with high-grade AVM treated with embolization or SRS, with the aim of achieving complete occlusion, was analyzed. Demographic, clinical, and angioarchitectonic variables were collected. Both treatments were compared for the occlusion rate and procedure-related complications. In addition, a cost-effectiveness analysis was performed. Thirty patients (52.6%) were men and 27 (47.4%) were women (mean age, 39 years). AVMs were unruptured in 43 patients (75.4%), and ruptured in 14 patients (24.6%). The presence of deep venous drainage, nidus volume, perforated arterial supply, and eloquent localization was more frequent in the SRS group. Complications such as hemorrhage or worsening of previous seizures were more frequent in the embolization group. No significant differences were observed in the occlusion rates or in the time necessary to achieve occlusion between the groups. The incremental cost-effectiveness ratio for endovascular treatment versus SRS was $53.279. Both techniques achieved similar occlusion rates, but SRS carried a lower risk of complications. Staged embolization may be associated with a greater risk of hemorrhage, whereas SRS was shown to have a better cost-effectiveness ratio. These results support SRS as a better treatment option for high-grade AVMs.

Usefulness of CT angiography for characterizing cerebral arteriovenous malformations presenting as hemorrhage: Comparison with digital subtraction angiography

ObjectiveTo compare the usefulness of CT angiography against the gold standard, digital subtraction angiography (DSA), in the characterisation of cerebral arteriovenous malformations (AVM) that present with bleeding. Material and methodsWe retrospectively analysed patients with intracranial bleeding due to an AVM who were included in a prospective database in the period comprising January 2007 through December 2012. We reviewed radiologic variables such as the characteristics of the AVM (size, location, presence of deep venous drainage), involvement of eloquent areas, and the presence of associated aneurysms. Two neuroradiologists blinded to clinical and radiological information analysed the CT and DSA in consensus. ResultsA total of 22 patients were included in the study. CT angiography correctly classified 15 of the 16 cases of AVM measuring less than 3cm (93.75% sensitivity). All cases of deep venous drainage and all those located in eloquent areas were correctly detected (100% sensitivity). The presence of any type of aneurysm related with the AVM was detected in 13 of 15 cases (86.6% sensitivity); 7 of 9 of the intranidal aneurysms were detected (77.78% sensitivity), as were 6 of the 9 flow aneurysms (66.67% sensitivity). ConclusionCT angiography is highly sensitive in the characterisation of cerebral AVMs measuring less than 3cm, of those located in eloquent areas, and of those with deep venous drainage; it is also highly sensitive in detecting aneurysms related with AVMs. However, CT angiography is less sensitive in detecting intranidal and flow aneurysms related with AVMs.

Utilidad de la angio-TC para la caracterización de malformaciones arteriovenosas cerebrales con presentación hemorrágica comparada con la angiografía por sustracción digital

ObjectiveTo compare the usefulness of CT angiography against the gold standard, digital subtraction angiography (DSA), in the characterization of cerebral arteriovenous malformations (AVM) that present with bleeding. Material and methodsWe retrospectively analyzed patients with intracranial bleeding due to an AVM who were included in a prospective database in the period comprising January 2007 through December 2012. We reviewed radiologic variables such as the characteristics of the AVM (size, location, presence of deep venous drainage), involvement of eloquent areas, and the presence of associated aneurysms. Two neuroradiologists blinded to clinical and radiological information analyzed the CT and DSA in consensus. ResultsA total of 22 patients were included in the study. CT angiography correctly classified 15 of the 16 cases of AVM measuring less than 3cm (93.75% sensitivity). All cases of deep venous drainage and all those located in eloquent areas were correctly detected (100% sensitivity). The presence of any type of aneurysm related with the AVM was detected in 13 of 15 cases (86.6% sensitivity); 7 of 9 of the intranidal aneurysms were detected (77.78% sensitivity), as were 6 of the 9 flow aneurysms (66.67% sensitivity). ConclusionCT angiography is highly sensitive in the characterization of cerebral AVMs measuring less than 3cm, of those located in eloquent areas, and of those with deep venous drainage; it is also highly sensitive in detecting aneurysms related with AVMs. However, CT angiography is less sensitive in detecting intranidal and flow aneurysms related with AVMs.

Critical review of brain AVM surgery, surgical results and natural history in 2017.

An understanding of the present standing of surgery, surgical results and the role in altering the future morbidity and mortality of untreated brain arteriovenous malformations (bAVMs) is appropriate considering the myriad alternative management pathways (including radiosurgery, embolization or some combination of treatments), varying risks and selection biases that have contributed to confusion regarding management. The purpose of this review is to clarify the link between the incidence of adverse outcomes that are reported from a management pathway of either surgery or no intervention with the projected risks of surgery or no intervention. A critical review of the literature was performed on the outcomes of surgery and non-intervention for bAVM. An analysis of the biases and how these may have influenced the outcomes was included to attempt to identify reasonable estimates of risks. In the absence of treatment, the cumulative risk of future hemorrhage is approximately 16% and 29% at 10 and 20years after diagnosis of bAVM without hemorrhage and 35% and 45% at 10 and 20years when presenting with hemorrhage (annualized, this risk would be approximately 1.8% for unruptured bAVMs and 4.7% for 8years for bAVMs presenting with hemorrhage followed by the unruptured bAVM rate). The cumulative outcome of these hemorrhages depends upon whether the patient remains untreated and is allowed to have a further hemorrhage or is treated at this time. Overall, approximately 42% will develop a new permanent neurological deficit or death from a hemorrhagic event. The presence of an associated proximal intracranial aneurysm (APIA) and restriction of venous outflow may increase the risk for subsequent hemorrhage. Other risks for increased risk of hemorrhage (age, pregnancy, female) were examined, and their purported association with hemorrhage is difficult to support. Both the Spetzler-Martin grading system (and its compaction into the Spetzler-Ponce tiers) and Lawton-Young supplementary grading system are excellent in predicting the risk of surgery. The 8-year risk of unfavorable outcome from surgery (complication leading to a permanent new neurological deficit with a modified Rankin Scale score of greater than one, residual bAVM or recurrence) is dependent on bAVM size, the presence of deep venous drainage (DVD) and location in critical brain (eloquent location). For patients with bAVMs who have neither a DVD nor eloquent location, the 8-year risk for an unfavorable outcome increases with size (increasing from 1cm to 6cm) from 1% to 9%. For patients with bAVM who have either a DVD or eloquent location (but not both), the 8-year risk for an unfavorable outcome increases with the size (increasing from 1cm to 6cm) from 4% to 35%. For patients with bAVM who have both a DVD and eloquent location, the 8-year risk for unfavorable outcome increases with size (increasing from 1cm to 3cm) from 12% to 38%. Patients with a Spetzler-Ponce A bAVM expecting a good quality of life for the next 8years are likely to do better with surgery in expert centers than remaining untreated. Ongoing research is urgently required on the outcome of management pathways for bAVM.

Multimodal Treatment Strategy for Spetzler-Martin Grade III Arteriovenous Malformations of the Brain.

The Spetzler–Martin (S–M) grading scale was developed to assess the risk of postoperative neurological complications after the surgical treatment of arteriovenous malformations (AVMs) of the brain. Treatment-associated morbidity and poor outcomes are particularly relevant to Grade III AVMs and improving the safety while attaining acceptable cure rates still poses a challenge. A multimodal treatment strategy combining surgery, embolization, and radiosurgery is recommended for S–M Grade III AVMs because of the surgical risk. Grade III AVMs are the heterogeneous group that has been further divided into subgroups according to the size, the location in eloquent cortex, and the presence of deep venous drainage. The risks associated with different treatment modalities vary depending on the subgroup, and the rating scales have been further refined to predict the risk more accurately and help determine the most appropriate treatment choice. Previous results for the treatment of S–M Grade III AVMs vary widely among studies, and the treatment modalities are also different in each study. Being familiar with previous treatment results is essential for improving treatment outcomes.

Role of surgery in the management of brain arteriovenous malformations: prospective cohort study.

Management of brain arteriovenous malformation (bAVM) is controversial. We have analyzed the largest surgical bAVM cohort for outcome. Both operated and nonoperated cases were included for analysis. A total of 779 patients with bAVMs were consecutively enrolled between 1989 and 2014. Initial management recommendations were recorded before commencement of treatment. Surgical outcome was prospectively recorded and outcomes assigned at the last follow-up visit using modified Rankin Scale. First, a sensitivity analyses was performed to select a subset of the entire cohort for which the results of surgery could be generalized. Second, from this subset, variables were analyzed for risk of deficit or near miss (intraoperative hemorrhage requiring blood transfusion of ≥2.5 L, hemorrhage in resection bed requiring reoperation, and hemorrhage associated with either digital subtraction angiography or embolization). A total of 7.7% of patients with Spetzler-Ponce classes A and B bAVM had an adverse outcome from surgery leading to a modified Rankin Scale >1. Sensitivity analyses that demonstrated outcome results were not subject to selection bias for Spetzler-Ponce classes A and B bAVMs. Risk factors for adverse outcomes from surgery for these bAVMs include size, presence of deep venous drainage, and eloquent location. Preoperative embolization did not affect the risk of perioperative hemorrhage. Most of the ruptured and unruptured low and middle-grade bAVMs (Spetzler-Ponce A and B) can be surgically treated with a low risk of permanent morbidity and a high likelihood of preventing future hemorrhage. Our results do not apply to Spetzler-Ponce C bAVMs.

Influence of the combination of patient age and deep venous drainage on brain arteriovenous malformation recurrence after surgery

Case reports suggest that young age is a critical factor in determining recurrence of brain arteriovenous malformations (AVMs) after surgery. However, other factors that may contribute to the increased risk of recurrence have not been considered. In this study, the authors' goal was to ascertain the risk and risk factors of recurrence after resection of AVMs of the brain. A consecutive case series (prospectively collected data) of 600 cases of resection of brain AVMs was retrospectively analyzed. Radiological evidence of recurrence or nonrecurrence, as well as clinical evidence of recurrence, could be established in 427 of these cases that underwent follow-up for more than 350 days after initial surgery. These cases were analyzed using Kaplan-Meier curves and Cox regression with respect to age and the presence of deep venous drainage. Nine recurrent AVMs were found in 8 patients. By analysis of the Kaplan-Meier curves, the 10-year recurrence rate was 14% for those with deep venous drainage, compared with 4% for those without deep venous drainage. Stratifying by age, in the 0- to 20-year age group, the 10-year recurrence rates were 63% and 13% for those with and without deep venous drainage, respectively. In the 20- to 39-year age group, the rates were 5% and 0% respectively, and in the 40-year and older age group they were 0% and 3%, respectively. The hazard ratio for deep venous drainage, adjusted for age, was 5.97 (95% CI 1.20-29.69, p = 0.029). The risk of recurrence after AVM resection is significant for young patients with deep venous drainage.

Outcome after hemorrhage following Gamma Knife surgery for cerebral arteriovenous malformations

Although the effects of Gamma Knife surgery (GKS) on the risk of hemorrhage are poorly understood, a certain subset of patients does suffer bleeding after GKS. This study was undertaken to analyze the outcome of patients sustaining hemorrhage after GKS; it is the most feared complication of radiosurgical management of cerebral arteriovenous malformations (AVMs). Between May 1997 and June 2006, 494 cerebral AVMs in 489 patients were treated using a Leksell Gamma Knife Model B, and follow-up evaluations were conducted until June 2007 at the All India Institute of Medical Sciences in New Delhi. Fourteen patients who sustained a hemorrhage after GKS formed the study group. In most of these patients conservative management was chosen. The mortality rate was 0% and there was a 7% risk of sustaining a severe deficit following rebleeding after GKS. None of the patients sustained rebleeding after complete obliteration. Patients with Spetzler-Martin Grade III or less had increased chances of hemorrhage after GKS (p < 0.002). The presence of deep venous drainage, aneurysm, venous hypertension, or periventricular location on angiography was common in patients with hemorrhage after GKS. The risk of hemorrhage that remains following GKS for cerebral AVMs is highest in the 1st year after treatment. The present study showed a relatively good outcome even in cases with hemorrhage following GKS, with no deaths and minimal morbidity, further substantiating the safety and efficacy of the procedure.

Neurologic Complications of Arteriovenous Malformation Embolization Using Liquid Embolic Agents

Embolization of arteriovenous malformations (AVMs) is commonly used to achieve nidal volume reduction before microsurgical resection or stereotactic radiosurgery. The purpose of this study was to examine the overall neurologic complication rate in patients undergoing AVM embolization and analyze the factors that may determine increased risk. We performed a retrospective review of all patients with brain AVMs embolized at 1 center from 1995 through 2005. Demographics, including age, sex, presenting symptoms, and clinical condition, were recorded. Angiographic factors including maximal nidal size, presence of deep venous drainage, and involvement of eloquent cortex were also recorded. For each embolization session, the agent used, number of pedicles embolized, the percentage of nidal obliteration, and any complications were recorded. Complications were classified as the following: none, non-neurologic (mild), transient neurologic deficit, and permanent nondisabling and permanent disabling deficits. The permanent complications were also classified as ischemic or hemorrhagic. Modified Rankin Scale (mRS) scores were collected pre- and postembolization on all patients. Univariate regression analysis of factors associated with the development of any neurologic complication was performed. Four hundred eighty-nine embolization procedures were performed in 192 patients. There were 6 Spetzler-Martin grade I (3.1%), 26 grade II (13.5%), 71 grade III (37.0%), 57 grade IV (29.7%), and 32 grade V (16.7%) AVMs. Permanent nondisabling complications occurred in 5 patients (2.6%) and permanent disabling complications or deaths occurred in 3 (1.6%). In addition, there were non-neurologic complications in 4 patients (2.1%) and transient neurologic deficits in 22 (11.5%). Five of the 8 permanent complications (2.6% overall) were ischemic, and 3 of 8 (1.6% overall) were hemorrhagic. Of the 178 patients who were mRS 0-2 pre-embolization, 4 (2.3%) were dependent or dead (mRS >2) at follow-up. Univariate analysis of risk factors for permanent neurologic deficits following embolization showed that basal ganglia location was weakly associated with a new postembolization neurologic deficit. Embolization of brain AVMs can be performed with a high degree of technical success and a low rate of permanent neurologic complications.

Small AVMs

Small arteriovenous malformations (AVMs) of the brain are typically categorized as smaller than 3 cm. Using this definition, we consider small AVMs to include typical AVMs with nidus size <3 cm, pial single-channel AV fistulas, and so-called “micro”-AVMs. Small AVMs are believed to have a higher risk of hemorrhage than larger AVMs. Because their size (<3 cm) accrues only one point for size in the Spetzler-Martin Grading System, small AVMs are all Spetzler-Martin Grades I–III, depending on the presence of deep venous drainage and/or eloquent location (each given an additional point). Thus, many believe direct surgical extirpation should be the preferred treatment for small AVMs because several series have demonstrated excellent surgical outcomes for Spetzler-Martin Grades I–III AVMs. However, stereotactic radiosurgery offers an alternative therapeutic option. The best radiosurgical clinical outcomes and obliteration rates have been associated with small AVMs with diameters <3 cm or volumes <10 cm 3. At the Massachusetts General Hospital, a multidisciplinary neurovascular unit treats AVMs with surgery, radiosurgery, and embolization. From 1991 to 1999, this multidisciplinary neurovascular unit treated 424 AVMs, of which 216 (51%) were small AVMs: 105 by surgery alone, 29 by surgery with preoperative embolization, 39 by radiosurgery, 6 by radiosurgery with preradiosurgical embolization, 35 by embolization alone, and 2 by surgery after incomplete radiosurgical obliteration. This article discusses aspects of our operative techniques for treating these small AVMs.

Arteriovenous Malformation Draining Vein Physiology and Determinants of Transnidal Pressure Gradients

Arteriovenous malformation (AVM) draining vein pressure (DVP) may have an influence on both the natural history of the disease and treatment outcome. The purposes of this study were to assess the relationship between DVP and other clinical and physiological variables and to characterize the transmission of arterial pressure across the AVM nidus. DVP measurements were carried out during elective AVM resection with isoflurane/nitrous oxide anesthesia with arterial carbon dioxide pressure of approximately 30 mm Hg. The gradient between the right atrium and operative measurement site was noted. Pre-excision feeding mean arterial pressure and DVP were measured with a 26-gauge needle simultaneously with systemic mean arterial pressure and central venous pressure (CVP). DVP was tested with systemic mean arterial pressure increased to approximately 20 mm Hg with phenylephrine or CVP increased with a Valsalva maneuver. Finally, preresection and postresection DVP values were compared. Relative to the site of measurement, DVP was 7 +/- 5 mm Hg at a CVP of -4 +/- 5 mm Hg (n = 45). There was no influence of presentation, presence of deep venous drainage, size, location, or prior embolization on DVP. In 19 patients, DVP decreased (8 +/- 4 to 5 +/- 3; P < 0.05) whereas CVP increased from pre- to postresection (-4 +/- 5 to -2 +/- 5; P < 0.05). For the phenylephrine challenge (n = 11), there was no difference (P = 0.84) between the delta DVP (2 +/- 1 mm Hg) and the delta CVP (2 +/- 3 mm Hg).(ABSTRACT TRUNCATED AT 250 WORDS)