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Navarro, Ramón

Mayo Clinic

Cleveland Clinic Abu Dhabi

Citations 2

Clinical and radiographic characteristics of sacral arteriovenous fistulas: a multicenter experience
Biase, Gaetano De , Navarro, Ramón, Santos, Jaime L. Martínez , Rivas, Gabriella , Miller, David A. , Brinjikji, Waleed , Huynh, Thien J, De Biase, Gaetano , Domingo, Ricardo A. , Gupta, Vivek , Bendok, Bernard R. , Fox, W Christopher , Huynh, Thien , Tawk, Rabih G.

Journal of Neurosurgery: Spine | October 22, 2021 | Volume: 36 | Issue: 3 | Pages: 487-497

10.3171/2021.5.spine21119 Get It

OBJECTIVE Available data on management of sacral arteriovenous fistulas (sAVFs) are limited to individual case reports and small series. Management includes observation, endovascular embolization, or surgical ligation, with no clear guidelines on the optimal treatment modality. The authors’ objective was to report their multiinstitutional experience with management of sAVF patients, including clinical and radiographic characteristics and postprocedural outcomes. METHODS The electronic medical records of patients with a diagnosis of spinal arteriovenous fistula treated from January 2004 to December 2019 at the authors’ institutions were reviewed, and data were summarized using descriptive statistics, including percentage and count for categorical data, median as a measure of central tendency for continuous variables, and interquartile range (IQR) as a measure of dispersion. RESULTS A total of 26 patients with sAVFs were included. The median (IQR) age was 65 (57–73) years, and 73% (n = 19) of patients were male. Lower-extremity weakness was the most common presenting symptom (n = 24 [92%]), and half the patients (n = 13 [50%]) reported bowel and bladder sphincter dysfunction. The median (IQR) time from symptom onset to treatment was 12 (5.25–26.25) months. Radiographically, all patients had T2 hyperintensity at the level of the conus medullaris (CM) (n = 26 [100%]). Intradural flow voids were identified in 85% (n = 22) of patients. The majority of the lesions had a single identifiable arterial feeder (n = 19 [73%]). The fistula was located most commonly at the S1 level (n = 13 [50%]). The site where the draining vein connects to the pial venous plexus was seen predominantly at the lumbar level (n = 16 [62%]). In total, 29 procedures were performed: 10 open surgeries and 19 endovascular embolization procedures. Complete occlusion was achieved in 90% (n = 9) of patients after open surgery and 79% (n = 15) after endovascular embolization. Motor improvement was seen in 68% of patients (n = 15), and bladder and bowel function improved in 9 patients (41%). At last follow-up, 73% (n = 16) of patients had either resolution or improvement of the pretreatment intramedullary T2 signal hyperintensity. CONCLUSIONS T2 hyperintensity of the CM and a dilated filum terminale vein are consistent radiographic signs of sAVF, and delayed presentation is common. Complete occlusion was achieved in almost all patients after surgery, and endovascular embolization was effective in 70% of the patients. Further studies are needed to determine the best treatment modality based on case-specific characteristics.
Flow diversion for complex intracranial aneurysms in young children
Navarro, Ramón, Brown, Benjamin L. , Beier, Alexandra D., Ranalli, Nathan J., Aldana, Philipp R. , Hanel, Ricardó A.

Journal of Neurosurgery: Pediatrics | January 2, 2015 | Volume: 15 | Issue: 3 | Pages: 276-281

10.3171/2014.9.peds14333 Get It

Pediatric intracranial aneurysms are exceedingly rare and account for less than 5% of all intracranial aneurysms. Open surgery to treat such aneurysms has been shown to be more durable than endovascular techniques, and durability of treatment is particularly important in the pediatric population. Over the past 2 decades, however, a marked shift in aneurysm treatment from open surgery toward endovascular procedures has occurred for adults. The authors describe their early experience in treating 3 unruptured pediatric brain aneurysms using the Pipeline embolization device (PED). The first patient, a girl with Majewski osteodysplastic primordial dwarfism Type II who was harboring multiple intracranial aneurysms, underwent two flow diversion procedures for a vertebrobasilar aneurysm and a supraclinoid internal carotid artery aneurysm. The second patient underwent PED placement on a previously coiled but enlarging posterior communicating artery aneurysm. All procedures were uneventful, with no postsurgical complications, and led to complete angiographic obliteration of the aneurysms. To the authors' knowledge, this is the first series of flow diversion procedures in children reported in the medical literature. While flow diversion is a new and relatively untested technology in children, outcomes in adults have been promising. For challenging lesions in the pediatric population, flow diversion may have a valuable role as a well-tolerated, safe treatment with durable results. Many issues remain to be addressed, such as the durability of flow diverters over a very long follow-up and vessel response to growth in the presence of an endoluminal device.