Search Results

You are looking at 1 - 8 of 8 items for

  • Author or Editor: Patrick Nicholson x
  • Refine by Access: all x
Clear All Modify Search
Full access

Stéphanie Lenck, Fabrice Vallée, Vittorio Civelli, Jean-Pierre Saint-Maurice, Patrick Nicholson, Alex Hong, and Emmanuel Houdart

Lateral venous sinus stenoses have been associated with idiopathic intracranial hypertension and venous pulsatile tinnitus. Venous pressure measurement is traditionally performed to assess the indications for stenting in patients with idiopathic intracranial hypertension. However, its reliability has recently been questioned by many authors. The dual-sensor guidewire was first developed for advanced physiological assessment of fractional and coronary flow reserves in coronary artery stenoses. It allows measurement of both venous pressure and blood flow velocities. The authors used this device in 14 consecutively treated patients to explore for symptomatic lateral sinus stenosis. They found that venous blood flow was significantly accelerated inside the stenotic lesion. This acceleration, as well as the pulsatile tinnitus, resolved in all patients following stent placement. According to the authors’ results, this guidewire can be helpful for establishing an indication for stenting in patients with pulsatile tinnitus and idiopathic intracranial hypertension.

Open access

Laura-Nanna Lohkamp, Nandan Marathe, Patrick Nicholson, Richard I. Farb, and Eric M. Massicotte

BACKGROUND

Cerebrospinal fluid–venous fistulas (CVFs) may cause cerebrospinal fluid leaks resulting in spontaneous intracranial hypotension (SIH). Surgical treatment of CVFs aims to eliminate abnormal fistulous connections between the subarachnoid space and the epidural venous plexus at the level of the nerve root sleeve. The authors propose a percutaneous minimally invasive technique for surgical ligation of CVF as an alternative to the traditional open approach using a tubular retractor system.

OBSERVATIONS

Minimally invasive surgical (MIS) ligation of spinal CVF was performed in 5 patients for 6 CVFs. The definite disconnection of the CVF was achieved in all patients by clipping and additional silk tie ligation of the fistula. None of the patients experienced surgical complications or required transition to an open procedure. One patient underwent 2 MIS procedures for 2 separate CVFs. Postoperative clinical follow-up and cranial magnetic resonance imaging confirmed resolution of symptoms and radiographic SIH stigmata.

LESSONS

MIS ligation of CVFs is safe and efficient. It represents an elegant and less invasive procedure, reducing the risk of wound infections and time to recovery. However, preparedness for open ligation is warranted within the same surgical setting in cases of complications and difficult accessibility.

Restricted access

Vitor Mendes Pereira, Patrick Nicholson, Nicole M. Cancelliere, Xiao Yu Eileen Liu, Ronit Agid, Ivan Radovanovic, and Timo Krings

OBJECTIVE

Geographic factors prevent equitable access to urgent advanced neuroendovascular treatments. Robotic technologies may enable remote endovascular procedures in the future. The authors performed a translational, benchtop-to-clinical study to evaluate the in vitro and clinical feasibility of the CorPath GRX Robotic System for robot-assisted endovascular neurointerventional procedures.

METHODS

A series of bench studies was conducted using patient-specific 3D-printed models to test the system’s compatibility with standard neurointerventional devices, including microcatheters, microwires, coils, intrasaccular devices, and stents. Optimal baseline setups for various procedures were determined. The models were further used to rehearse clinical cases. Subsequent to these investigations, a prospective series of 6 patients was treated using robotic assistance for complex, wide-necked intracranial saccular aneurysms between November 2019 and February 2020. The technical success, incidence of periprocedural complications, and need for conversion to manual procedures were evaluated.

RESULTS

The ideal robotic setup for treatment of both anterior and posterior circulation aneurysms was determined to consist of an 80-cm guide catheter with a 115-cm-long intermediate catheter, a microcatheter between 150 and 170 cm in length, and a microwire with a minimum length of 300 cm. All coils, intrasaccular devices, and stents tested were compatible with the system and could be advanced or retracted safely and placed accurately. All 6 clinical procedures were technically successful, with all intracranial steps being performed robotically with no conversions to manual intervention or failures of the robotic system. There were no procedure-related complications or adverse clinical outcomes.

CONCLUSIONS

This study demonstrates the feasibility of robot-assisted neurointerventional procedures. The authors’ results represent an important step toward enabling remote neuroendovascular care and geographic equalization of advanced endovascular treatments through so-called telestroke intervention.

Restricted access

Nitin Mukerji, Alistair Jenkins, Claire Nicholson, and Patrick Mitchell

Object

The pediatric neurosurgery practice over 2 years was reviewed at a tertiary neurosciences center. The intention was to establish the frequency of unplanned reoperations at the center, investigate the factors responsible, and consider using unplanned reoperations as a quality indicator.

Methods

All pediatric neurosurgical operations done between January 2008 and January 2010 were reviewed using data from operation theater logs and hospital records. Data were recorded as per the standard requirements of the Society of British Neurological Surgeons for incorporation into the national database. “Unplanned reoperation” was defined as any unscheduled secondary procedure required for a complication resulting directly or indirectly from the index operation or as an unscheduled return to the operating theater for the same condition. Operations were defined as “urgent” if they had to be performed out of hours (that is, outside the hours of 8:00 a.m. to 5:00 p.m.), “emergency elective” if they were included on the emergency list but within working hours, and “routine elective” if they were on the scheduled operations list. Both overall and 30-day unplanned reoperation rates were considered. Factors influencing unplanned reoperations were explored using a logistic regression model.

Results

Four hundred ten operations were analyzed. The overall unplanned reoperation rate was 28%. The median time to an unplanned reoperation was 9 days. Risk factors for unplanned reoperations included a CSF diversion procedure (OR 7, p < 0.0001) and an urgent procedure (OR 2.5, p = 0.02, higher unplanned reoperations for urgent procedures relative to routine electives). The 30-day unplanned reoperation rate was 17%. Urgent cases composed 32% of all operations. Trainees performed 52% of the urgent operations. Forty-four percent of all operations were related to CSF diversion. Sixty-four percent of patients had reoperations during the course of the study period, and 44% of these reoperations were unplanned.

Conclusions

An unplanned return to the operation theater is common in the authors' pediatric neurosurgical practice and is procedure specific. Unplanned reoperation rates may be useful for monitoring quality across hospitals and identifying opportunities for quality improvement. The authors propose the use of this index as a quality indicator and advocate its validation in a prospective multicenter study.

Restricted access

Stephanie Lenck, Aurelien Nouet, Eimad Shotar, Samiya Abi Jaoudé, Patrick Nicholson, Kevin Premat, Celine Corcy, Anne-Laure Boch, Nader Antoine Sourour, Frederic Tankere, Alexandre Carpentier, and Frederic Clarençon

OBJECTIVE

Based on their clinical and radiological patterns, idiopathic CSF rhinorrhea and idiopathic intracranial hypertension can represent different clinical expressions of the same underlying pathological process. Transverse sinus stenoses are associated with both diseases, resulting in eventual restriction of the venous CSF outflow pathway. While venous sinus stenting has emerged as a promising treatment for idiopathic intracranial hypertension, its efficiency on idiopathic CSF leaks has not been very well addressed in the literature so far. The purpose of this study was to report the results of transverse sinus stenting in patients with spontaneous CSF rhinorrhea associated with transverse sinus stenoses.

METHODS

From a prospectively collected database, the authors retrospectively collected the clinical and radiological features of the patients with spontaneous CSF leakage who were treated with venous sinus stenting.

RESULTS

Five female patients were included in this study. Transverse sinus stenoses were present in all patients, and other radiological signs of idiopathic intracranial hypertension were present in 4 patients. The median transstenotic pressure gradient was 6.5 mm Hg (range 3–9 mm Hg). Venous stenting resulted in the disappearance of the leak in 4 patients with no recurrence and no subsequent meningitis during the follow-up (median 12 months, range 6–63 months).

CONCLUSIONS

According to the authors’ results, venous sinus stenting may result in the disappearance of the leak in many cases of idiopathic CSF rhinorrhea. Larger comparative studies are needed to assess the efficiency and safety of venous stenting as a first-line approach in patients with spontaneous CSF rhinorrhea associated with transverse sinus stenoses.

Restricted access

Sean T. O’Reilly, Eef Jacobus Hendriks, Marie-Christine Brunet, Ze’ev Itsekson, Rabab Al Shahrani, Ronit Agid, Patrick Nicholson, Karel terBrugge, Ivan Radovanovic, and Timo Krings

OBJECTIVE

Spinal dural arteriovenous fistulas (SDAVFs) typically represent abnormal shunts between a radiculomeningeal artery and radicular vein, with the point of fistulization classically directly underneath the pedicle of the vertebral body, at the dural sleeve of the nerve root. However, SDAVFs can also develop in atypical locations or have more than one arterial feeder, which is a variant of SDAVF. The aim of this study was to describe the incidence and multidisciplinary treatment of variant SDAVFs in a single-center case series.

METHODS

Following institutional review board approval, the authors retrospectively analyzed their prospectively maintained database of patients with SDAVFs who presented between 2008 and 2020. For all patients, spinal digital subtraction angiograms were reviewed and variant SDAVFs were identified. Variant types of SDAVFs were defined as cases in which the fistulous point was not located underneath the pedicle. Patient demographics, angiographic features, clinical outcomes, and treatment modalities were assessed.

RESULTS

Of 59 patients with SDAVFs treated at the authors’ institution, 4 patients (6.8%) were identified as having a variant location of the shunt zone, pinpointed on the dura mater at the intervertebral level, further posteriorly within the spinal canal. In 3 cases (75%), a so-called bimetameric arterial supply was demonstrated.

CONCLUSIONS

Recognition of the variant type of SDAVF is crucial for management, as correct localization of the fistulous point and bimetameric supply are critical for successful surgical disconnection, preventing delay in achieving definitive treatment.

Free access

Adam A. Dmytriw, Anish Kapadia, Alejandro Enriquez-Marulanda, Carmen Parra-Fariñas, Anna Luisa Kühn, Patrick J. Nicholson, Muhammad Waqas, Leonardo Renieri, Caterina Michelozzi, Paul M. Foreman, Kevin Phan, I-Hsiao Yang, Vincent M. Tutino, Christopher S. Ogilvy, Ivan Radovanovic, Mark R. Harrigan, Adnan H. Siddiqui, Elad I. Levy, Nicola Limbucci, Christophe Cognard, Timo Krings, Vitor Mendes Pereira, Ajith J. Thomas, Thomas R. Marotta, and Christoph J. Griessenauer

OBJECTIVE

Coverage of the anterior spinal artery (ASA) ostia is a source of considerable consternation regarding flow diversion (FD) in vertebral artery (VA) aneurysms due to cord supply. The authors sought to assess the association between coverage of the ASA, posterior spinal artery (PSA), or lateral spinal artery (LSA) ostia when placing flow diverters in distal VAs and clinical outcomes, with emphasis on cord infarction.

METHODS

A multicenter retrospective study of 7 institutions in which VA aneurysms were treated with FD between 2011 and 2019 was performed. The authors evaluated the risk of ASA and PSA/LSA occlusion, associated thromboembolic complication, complications overall, aneurysm occlusion status, and functional outcome.

RESULTS

Sixty patients with 63 VA and posterior inferior cerebellar artery aneurysms treated with FD were identified. The median aneurysm diameter was 7 mm and fusiform type was the commonest morphology (42.9%). During a procedure, 1 (61.7%) or 2 (33.3%) flow diverters were placed. Complete occlusion was achieved in 71.9%. Symptomatic thromboembolic complications occurred in 7.4% of cases and intracranial hemorrhage in 10.0% of cases. The ASA and PSA/LSA were identified in 51 (80.9%) and 35 (55.6%) complications and covered by the flow diverter in 29 (56.9%) and 13 (37.1%) of the procedures, respectively. Patency after flow diverter coverage on last follow-up was 89.2% for ASA and 100% for PSA/LSA, not significantly different between covered and noncovered groups (p = 0.5 and p > 0.99, respectively). No complications arose from coverage.

CONCLUSIONS

FD aneurysm treatment in the posterior circulation with coverage of ASA or PSA/LSA was not associated with higher rates of occlusion of these branches or any instances of cord infarction.

Free access

Adam A. Dmytriw, Anish Kapadia, Alejandro Enriquez-Marulanda, Carmen Parra-Fariñas, Anna Luisa Kühn, Patrick J. Nicholson, Muhammad Waqas, Leonardo Renieri, Caterina Michelozzi, Paul M. Foreman, Kevin Phan, I-Hsiao Yang, Vincent M. Tutino, Christopher S. Ogilvy, Ivan Radovanovic, Mark R. Harrigan, Adnan H. Siddiqui, Elad I. Levy, Nicola Limbucci, Christophe Cognard, Timo Krings, Vitor Mendes Pereira, Ajith J. Thomas, Thomas R. Marotta, and Christoph J. Griessenauer

OBJECTIVE

Coverage of the anterior spinal artery (ASA) ostia is a source of considerable consternation regarding flow diversion (FD) in vertebral artery (VA) aneurysms due to cord supply. The authors sought to assess the association between coverage of the ASA, posterior spinal artery (PSA), or lateral spinal artery (LSA) ostia when placing flow diverters in distal VAs and clinical outcomes, with emphasis on cord infarction.

METHODS

A multicenter retrospective study of 7 institutions in which VA aneurysms were treated with FD between 2011 and 2019 was performed. The authors evaluated the risk of ASA and PSA/LSA occlusion, associated thromboembolic complication, complications overall, aneurysm occlusion status, and functional outcome.

RESULTS

Sixty patients with 63 VA and posterior inferior cerebellar artery aneurysms treated with FD were identified. The median aneurysm diameter was 7 mm and fusiform type was the commonest morphology (42.9%). During a procedure, 1 (61.7%) or 2 (33.3%) flow diverters were placed. Complete occlusion was achieved in 71.9%. Symptomatic thromboembolic complications occurred in 7.4% of cases and intracranial hemorrhage in 10.0% of cases. The ASA and PSA/LSA were identified in 51 (80.9%) and 35 (55.6%) complications and covered by the flow diverter in 29 (56.9%) and 13 (37.1%) of the procedures, respectively. Patency after flow diverter coverage on last follow-up was 89.2% for ASA and 100% for PSA/LSA, not significantly different between covered and noncovered groups (p = 0.5 and p > 0.99, respectively). No complications arose from coverage.

CONCLUSIONS

FD aneurysm treatment in the posterior circulation with coverage of ASA or PSA/LSA was not associated with higher rates of occlusion of these branches or any instances of cord infarction.