Self-expanding Mesh Research Articles

BHSeP36 Laparoscopic mesh repair of sciatic hernia containing ureter and small bowel: a case report

Abstract Sciatic hernia is one of the rarest forms of pelvic hernia, accounting for around 0.01% of all abdominal wall hernias. They are more common in females, and the presentation can vary depending on the hernia contents. The literature initially suggested repair with open trans-gluteal or trans-abdominal approaches, though in more recent years there has been a shift towards laparoscopic techniques. We report our experience of performing laparoscopic mesh repair of a sciatic hernia in a 79 year old woman. The patient was experiencing abdominal pain and subsequent investigations revealed an off-baseline eGFR and a CT scan showing hydroureteronephrosis secondary to a sciatic hernia containing ureter and non-obstructed small bowel. Laparoscopic repair of the sciatic hernia was performed using placement of a self-expanding polypropylene mesh patch; cyanoacrylate glue was used to fix the mesh in place and to close the peritoneum. The patient made a good post-operative recovery and was discharged home the same day. In conclusion, this rare form of hernia was successfully treated using a laparoscopic approach with placement of a mesh patch and cyanoacrylate glue.

In-Vitro Model-Based Performance Testing Of A SelfExpanding Clot Retrieval Device

The Clot Retrieval Device is designed to restore blood flow in patients suffering from acute ischemic stroke by effectively removing thrombus in neuro vasculature. This research article presents an in-vitro simulation test methodology aimed at evaluating the performance, safety, and efficiency of this thrombectomy device. The simulation replicates clinical conditions, offering insights into device performance before clinical application. The device's self-expanding mesh structure, designed with giant-baby cells, has demonstrated superior thrombus retrieval efficiency while minimizing damage to vascular tissue. The test methodology involves creating blood clot analogs that mimic human thrombi, followed by testing the device's retrieval efficacy under controlled simulated conditions. Research results indicate that the device demonstrates high retrieval success rates, contributing to improved clinical outcomes for stroke patients

Aortoesophageal fistula after endoscopic stenting of the esophageal tumor

This article describes 2 clinical cases of aorto-esophageal fistula (AEF) in patients after endoscopic stenting of the esophagus with a self-expanding mesh stent, which we encountered in our institution (City Clinical Oncology Center, St. Petersburg). In addition, a review of the available literature on this issue was carried out with a special focus on the risk factors for the development of AEF.

Primary upper lumbar hernia repaired by transabdominal preperitoneal approach technique using a self-expanding mesh with a memory-recoil ring, report of a case

BackgroundUpper lumber hernia is a rare entity which can cause obstruction and strangulation. Laparoscopic technique has been considered effective for such hernia repairs; however, there is no report of use of the self-expanding mesh.Case presentationA 77-year-old woman visited to our hospital complaining of a bulge of about 5 cm in the left lumbar dorsal region while standing. Abdominal CT and MRI scans showed a fascial defect in the left lumbar abdominal wall and confirmed the presence of a hernia, in which retroperitoneal fatty tissue and the descending colon protruded. Transabdominal preperitoneal repair (TAPP) was performed and the operative findings revealed the hernia orifice, 3 × 2.5 cm in diameter, between two intercostal nerves. To avoid nerve injury or entrapment, the number of mesh fixation was desirable minimum; therefore, a self-expanding mesh with a memory-recoil ring was used. The mesh, 9.5 × 13 cm in diameter, was placed and tacked to the abdominal wall at two points, 1 cm ventral and dorsal to the hernia orifice. The postoperative course was uneventful and no pain or recurrence was observed with follow-up of 6 months.ConclusionWe herein present a case of upper lumber hernia successfully repaired by TAPP with a self-expanding mesh.

Ventral Hernia Repair Using Ventralex® ST Patch: A Single-Center Study of Clinical Outcomes and Complications.

BackgroundVentralex® ST (Bard Davol Inc, Warwick, RI) patch is a composite self-expanding and non-absorbable mesh used to reinforce ventral hernia repair. This study was conducted to assess the efficacy, post-operative clinical outcomes, the duration of operation, and complications deciding the post-operative duration/need of hospitalization in patients of small ventral hernia after their open surgical repair using Ventralex ST hernia patch.Materials and methodsWe included 36 patients diagnosed with a small (<2 cm defect size) ventral hernia who underwent open mesh repair following strict surgical methodology using Ventralex® ST hernia patch between September 2018 and April 2020. It was a prospective observational study. Clinically relevant characteristics, along with operative and post-operative data collected through direct interview, clinical examination, and a pretested proforma, were analyzed prospectively.ResultsThirty-four patients (94.5%) were observed to have an operative time of fewer than 60 minutes, with an average duration of 30-40 minutes. Thirty-one patients (86%) were discharged within 48 hours of surgery, out of which 17 patients (47.2%) were discharged within 24 hours of surgery and 14 patients (38.8%) within 48 hours. Only five patients (13.88%) had a prolonged hospital stay for more than 48 hours due to post-operative complications. Three patients (8.33%) acquired post-surgical wound infection, whereas two (5.55%) developed seroma. Nevertheless, just one patient (2.7%) reportedly developed both infection and seroma after surgery. No cases of mesh infection or recurrences were noted.ConclusionThis study demonstrates that open repair of small (<2 cm defect size) ventral hernia using the Ventralex® ST hernia patch can be an extremely safe and effective method. Furthermore, it has excellent clinical outcomes when meticulously used with an easily reproducible surgical technique, which requires less intra-operative time, has minimal post-operative complications and negligible recurrence rate, along with reduced post-op hospital stay (86% of patients being discharged within 48 hours).

The Woven EndoBridge (WEB) device: feasibility, techniques, and outcomes after FDA approval.

Wide-neck bifurcation cerebral aneurysms have historically required either clip ligation or stent- or balloon-assisted coil embolization. This predicament led to the development of the Woven EndoBridge (WEB) aneurysm embolization system, a self-expanding mesh device that achieves intrasaccular flow disruption and does not require antithrombotic medications. The authors report their operative experience and 6-month follow-up occlusion outcomes with the first 115 aneurysms they treated via WEB embolization. The authors reviewed the first 115 cerebral aneurysms they treated by WEB embolization after FDA approval of the WEB embolization device (from February 2019 to January 2021). Data were collected on patient demographics and clinical presentation, aneurysm characteristics, procedural details, postembolization angiographic contrast stasis, and functional outcomes. A total of 110 patients and 115 aneurysms were included in our study (34 ruptured and 81 unruptured aneurysms). WEB embolization was successful in 106 (92.2%) aneurysms, with a complication occurring in 6 (5.5%) patients. Contrast clearance was seen in the arterial phase in 14 (12.2%) aneurysms, in the capillary phase in 16 (13.9%), in the venous phase in 63 (54.8%), and no contrast was seen in 13 (11.3%) of the aneurysms studied. Follow-up angiography was performed on 60 (52.6%) of the aneurysms, with complete occlusion in 38 (63.3%), neck remnant in 14 (23.3%), and aneurysmal remnant in 8 (13.3%). Six (5.5%) patients required re-treatment for persistent aneurysmal residual on follow-up angiography. The WEB device has been successfully used for the treatment of both unruptured and ruptured wide-neck bifurcation aneurysms by achieving intrasaccular flow diversion. Here, the authors have shared their experience with its unique technical considerations and device size selection, as well as critically reviewed complications and aneurysm occlusion rates.

Self-expanding intestinal expansion sleeves (IES) for short gut syndrome.

Many disease processes (necrotizing enterocolitis, caustic esophageal injury, malrotation with volvulus), can result in short-gut syndrome (SGS), where remnant intestinal segments may dilate axially, but rarely elongate longitudinally. Here we mechanically characterize a novel model of a self-expanding mesh prototype intestinal expanding sleeve (IES) for use in SGS. Gut lengthening was achieved using a proprietary cylindrical layered polyethylene terephthalate IES device with helicoid trusses with isometric ends. The IES is pre-contracted by diametric expansion, deployed into the gut and anchored with bioabsorbable sutures. IES expansion to its equilibrium dimension maintained longitudinal gut tension, which may permit remodeling, increased absorptive surface area while preserving vascular and nervous supplies. We performed mechanical testing to obtain the effective force-displacement characterization achieved on these prototypes and evaluated minimal numbers of sutures needed for its anchoring. Furthermore, we deployed these devices in small and large intestines of New Zealand White rabbits, measured IES length-tension relationships and measured post-implant gut expansion ex vivo. Histology of the gut before and after implantation was also evaluated. Longitudinal tension using IES did not result in suture failure. Maximum IES suture mechanical loading was tested using 4-6 sutures; we found similar failure loads of 2.95 ± 0.64, 4 ± 1.9 and 3.16 ± 0.24 Newtons for 4, 6 and 8 sutures, respectively (n = 3, n.s). Pre-contracted IES tubes were deployed at 67 ± 4% of initial length (i.l.); in the large bowel these expanded significantly to 81.5 ± 3.7% of i.l. (p = 0.014, n = 4). In the small bowel, pre-contracted IES were 61 ± 3.8% of i.l.; these expanded significantly to 82.7 ± 7.4% of i.l. (p = 0.0009, n = 6). This resulted in an immediate 24 ± 7.8% and 36.2 ± 11% increase in gut length when deployed in large and small bowels, respectively, with maintained longitudinal tension. Maintained IES induced tension produced gut wall thinning; gut histopathological evaluation is currently under evaluation. IES is a versatile platform for gaining length in SGS, which may be simply deployed via feeding tubes. Our results need further validation for biocompatibility and mechanical characterization to optimize use in gut expansion.

EP.TH.652Use of the Proceed Ventral Patch (PVP) Mesh for Small to Medium sized defects in Ventral Hernia Repair over 10 years – Simple, Safe and Secure

Abstract Aims The Proceed Ventral Patch (PVP) has been in use since the late 2000s and is a self-expanding lightweight mesh patch comprised of multiple layers of absorbable and non-absorbable materials including polypropylene and polydioxanone. It is intended for use in all ventral hernias. We report our single-centre experience of using the mesh with primary outcomes being recurrence and reoperation for recurrence, readmission within 21 days for post-operative complications and discharge as day-case. Methods Retrospective review of case notes from 54 patients who were operated between October 2010 and November 2020 was undertaken. Patient characteristics were of a 2.1: 1 Male:Female ratio with a median age of 56 years old. 3 epigastric hernias and 51 paraumbilical hernias were repaired using either a 4.3cm or 6.4cm Proceed Ventral Patch. The size of the hernia defect ranged from 0.5cm to 4cm with a median defect size of 2cm for the 54 patients. Results There were no intraoperative complications. Two patients (0.04%) underwent laparoscopic reoperation for recurrence. Only one (0.02%) patient was readmitted within 21 days for a wound abscess which was drained and treated with a VAC dressing with satisfactory healing. The operations were split between nine different surgeons of varying expertise from ST5 level to Consultant level. Conclusions Ventral hernia repair with PVP is intuitive to learn and has low recurrence/complication rates.

Self-Expanding Anchors for Stabilizing Percutaneously Implanted Microdevices in Biological Tissues.

Percutaneously implanted miniaturized devices such as fiducial markers, miniaturized sensors, and drug delivery devices have an important and expanding role in diagnosing and treating a variety of diseases. However, there is a need to develop and evaluate anchoring methods to ensure that these microdevices remain secure without dislodgement, as even minimal migration within tissues could result in loss of microdevice functionality or clinical complications. Here we describe two anchoring methods made from biocompatible materials: (1) a self-expanding nitinol mesh anchor and (2) self-expanding hydrogel particles contained within pliable netting. We integrate these anchors into existing drug-screening microdevices and experimentally measure forces required to dislodge them from varying tissues. We report similar dislodgement forces of 738 ± 37, 707 ± 40, 688 ± 29, and 520 ± 28 mN for nitinol-anchored microdevices, and 735 ± 98, 702 ± 46, 457 ± 47, and 459 ± 39 mN for hydrogel-anchored microdevices in liver, kidney, fat, and muscle tissues, respectively—significantly higher compared with 13 ± 2, 15 ± 3, 15 ± 2, and 15 ± 3 mN for non-anchored microdevices (p < 0.001 in all tissues). The anchoring methods increased resistance to dislodgement by a factor of 30–50× in all tissues, did not increase the required needle gauge for insertion, and were compatible with percutaneous implantation and removal. These results indicate that anchoring significantly improves microdevice stability and should reduce migration risk in a variety of biological tissues.

Single Center Observational Study to Evaluate the Safety and Efficacy of Self-expanding Composite Mesh for Repair of Small Umbilical Hernias

Background: There is evidence that mesh repair for umbilical hernias results in fewer recurrences. Early and late complication rates of mesh repair are variable with different techniques of mesh repair. In recent years, several mesh device for the repair of small ventral hernias have been developed, but some reports have been published reporting some adverse outcomes like high recurrences or wound related complications encountered with those mesh devices. The purpose of this study was to evaluate the safety and efficacy of small umbilical hernia(&lt;3cm) repair using self expanding dual mesh.&#x0D; Methods: In this study we used a composite self-expanding mesh with Polypropylene(PP) on one side and expanded polytetrafleuroethylene(ePTFE) on the other side. We introduced this technique in our department at BIRDEM General Hospital and IMC in March 2017 and collected patients data and outcome in an observational study of 25 consecutive patients matching our inclusion criteria until February 2019. In addition to the routine 1st week postoperative follow-up, We did a prospective follow-up at 1 month,6 month and 1 year which included a questionnaire, clinical examination and ultra sonogram after 12 months.&#x0D; Results: The study included 15 female and 10 male patients with age ranging from 25-62 years(Mean- 47) having 16 primary umbilical hernia and 9 umbilical port hernias. The size of gap was &lt;3cm and all except 2 hernias were reducible. In all patients a self expanding dual mesh was used with a diameter of 8cm(18 patients) or 6.4(7 patients) cm. Early complications included superficial wound infection-1(4%), seroma-1(4%), serosanguinous discharge-1(4%) and ecchymosis-1(4%). No major wound problems were noted in 1 month or 6 month follow-up except 1 patient reporting hypertrophied scar. At 1st month follow up 21 patientswere pain free, after 6 month only 1 patient reported mild pain, after 1 year 100% patients were pain free. 24 out of 25 patients ie 96% were very satisfied with the result of their repair. There was no recurrence after one year.&#x0D; Conclusion: Umbilical and umbilical port hernia repair with Self expanding dual mesh is effective and is cosmetically very appreciated by patients as good as laparoscopic repair. Therefore, we recommend using these meshes only for umbilical and umbilical port hernias smaller than 3 cm. For larger or incisional hernias other techniques allowing the use of larger meshes is advocated.&#x0D; Journal of Surgical Sciences (2020) Vol. 24 (2) : 43-50

Large-Bore Aspiration Thrombectomy: Catalyst for a Revolution in Treating Pulmonary Embolism

Large-Bore Aspiration Thrombectomy: Catalyst for a Revolution in Treating Pulmonary Embolism

Indications and Usage of New Devices such as PulseRider and W-EB for Bifurcation-type Aneurysms

Bifurcation-type aneurysms located at the basilar tip, anterior communicating artery, and middle cerebral artery are difficult to treat by endovascular coil embolization. One reason for this is that it is impossible to completely cover the aneurysm neck with a single stent because of the branching of two large vessels at the location. Moreover, the parent artery blood flows directly into the aneurysm dome and induces recanalization of the placed coils. In 2020, new devices for bifurcation aneurysms, such as PulseRider and W-EB, were approved in Japan. PulseRider has been in use since September, and W-EB is expected to be available by the end of the year. PulseRider has unique leaflets, which easily cover the broad neck of bifurcation aneurysms and prevent the coil from protruding into the parent artery. W-EB is a nitinol self-expandable mesh ball implant that can prevent blood flow into the aneurysm and subsequent induced thrombosis by deployment in the aneurysm sac. Although we do not yet completely know the features and advantages of either, we expect these two new devices to improve endovascular treatment of bifurcation-type aneurysms that thus far have been difficult to treat.

Low profile vascular plug for transarterial occlusion of patent ductus arteriosus in small dogs.

BackgroundMinimally invasive transcatheter occlusion using Amplatz canine duct occluder (ACDO) is the treatment of choice for dogs with left‐to‐right shunting patent ductus arteriosus (PDA). However, in small dogs the femoral artery diameter is often too small to accommodate the guiding catheter required for ACDO deployment.ObjectiveDescribe the effectiveness of transarterial implantation of Amplatzer Vascular Plug 4 (AVP‐4), the only self‐expandable nitinol mesh occlusion device which can be implanted through a 4 French diagnostic catheter, in small dogs with left‐to‐right shunting PDA.AnimalsSeven client‐owned dogs.MethodsDescriptive case series. Dogs with hemodynamically relevant left‐to‐right shunting PDA and a femoral artery diameter less than 2.0 mm measured preoperatively with ultrasonography were prospectively enrolled.ResultsAngiography after releasing the device showed complete immediate PDA closure in 5 dogs, where the manufacturers' recommendation were strictly followed (30%‐50% device oversizing of the ductal ampulla's diameter). Trivial residual flow on angiography in the 6th dog, whose device was slightly undersized, had resolved on echocardiography within 2 hours after placement. Marked device undersizing in the 7th dog resulted in severe residual shunting, which necessitated the addition of a coil. In this dog, the AVP‐4 embolized into the pulmonary artery within 2 weeks after placement.Conclusions and Clinical ImportanceTransarterial implantation of AVP‐4 is a safe, effective and technically easy procedure for PDA occlusion in small dogs and offers a valuable alternative to coil implantation. Accurate PDA measurement and device sizing is essential to prevent residual shunting, inadvertent device embolization, and protrusion of the device into the aorta.

Robotic-assisted pulley technique for the ventral hernia.

When approaching complex abdominal wall hernias at either index operation or a subsequent reoperation for recurrent incarcerated abdominal wall hernias, a majority of surgeons consider mesh placement a key step in the prevention of a future recurrence. While the laparoscopic and open approaches show no significant difference in hernia recurrence, the laparoscopic approach to complex abdominal wall hernias does reduce surgical-site infection, postoperative ileus, improves short-term quality-of-life scores, and reduces hospital length of stay (Davies et al. in Am Surg 78(8):888-892, https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3500604/ , 2012, McGreevy et al. in Surg Endosc 17(11):1778-1780, https://www.ncbi.nlm.nih.gov/pubmed/12958679 , 2003, Bittner et al. in Surg Endosc 33:3069-3139, https://doi.org/10.1007/s00464-019-06907-7 , 2019). In this paper, we describe a robotic approach with a pulley technique to the fixation of polypropylene mesh in complex abdominal wall reconstruction. Our primary aim is to offer a new perspective to the re-creation of challenging abdominal walls and to encourage other surgeons to gain proficiency in the robotic approach. Additionally, the material cost to the technique is lower than that of self-expanding or deployable mesh reinforcements used in other laparoscopic approaches. Over time, as an institution breaks even on the cost of a robot with their return on investment, this technique offers potential cost-saving.

Basilar artery fenestration aneurysm treated with the Woven EndoBridge device

Arterial fenestrations are anomalies in embryonic vascular development and considered rare congenital variations. The management of fenestration aneurysms of the lower third of the basilar artery is challenging because of complex morphology. Given its relationship with the skull base and critical neurovascular structures, endovascular treatment is preferred over microsurgery, and allows the use of a range of different endovascular devices and techniques. The Woven EndoBridge (WEB) device was specifically developed for treating wide-neck aneurysms in arterial bifurcations and is a self-expanding braided mesh of nitinol with platinum core. The devicés dense metal mesh disrupts intra-aneurysmal blood flow and promotes intrassacular thrombosis, while the mesh and neck together create a surface favorable to neo-endothelialization. The WEB allows solely endosaccular treatment, without the need for further implants in the lumen of parent vessels, thereby reducing the risk of complications and dispensing with the need for antiplatelet therapy. The present study reports the successful treatment of a basilar artery fenestration aneurysm using the WEB device.

Treatment of Acutely Ruptured Cerebral Aneurysms With the Woven EndoBridge Device: Experience Post-FDA Approval.

Coil embolization of ruptured bifurcation aneurysms is challenging and often necessitates adjunctive stenting, which requires antiplatelet therapy in the setting of subarachnoid hemorrhage (SAH). The Woven EndoBridge (WEB; Terumo) device is an alternative self-expanding 3D mesh that does not require antiplatelet agents. However, its use has been mostly reserved for unruptured aneurysms. To assess the safety and feasibility of ruptured aneurysm treatment with the WEB. Retrospective analysis of 9 SAH patients with 11 aneurysms that were treated with the WEB device at 2 institutions after FDA approval. Hunt and Hess grades were III and IV in 4 (44%) each and V in 1 (11%). All patients were treated within 24 h of hospitalization, and a single WEB was used in all but one aneurysm. Aneurysms treated were 3 basilar tip, 2 anterior communicating artery, 2 posterior inferior cerebellarartery, 1 middle cerebral artery, 1 carotid-ophthalmic artery, 1 posterior communicating artery, and 1 vertebrobasilar junction. Mean aneurysm height and width were 6.2±2.2mm (range: 3-10) and 5.6±3.0mm (range: 3.3-14), respectively. Mean dome-to-neck ratio was 1.7±0.8 (range: 1.0-3.8). There was one intraoperative rupture that occurred because of device dislodgement and was managed with embolization. There were no treatment-related mortalities and no re-rupture after securement of the aneurysms with the WEB. Our preliminary experience indicates that the WEB device can be used safely for ruptured aneurysms of various sizes in the anterior and posterior circulation. Larger series with long-term follow-up are necessary to confirm our findings.

Abstract WP33: Early Lessons Learned From the WEB Device: Feasibility, Technique and Complications—A Real Life Experience

Introduction: Wide-neck bifurcation cerebral aneurysms have always posed a treatment challenge and have historically required either clip ligation, or stent vs. balloon-assisted coil embolization. This predicament led to the development of the newly FDA-approved Woven EndoBridge (WEB) aneurysm embolization system (Sequent Medical Inc, Aliso Viejo, CA) Which is a self-expanding mesh that achieves intrasaccular flow disruption and does not require antithrombotic medications. In this study, we report our experience with the first 64 consecutive aneurysms treated via WEB embolization at two high-volume institutions. Methods: We reviewed our first 61 consecutive patients with 64 cerebral aneurysms who underwent WEB embolization from February-August 2019. We collected data on patient demographics and clinical presentation, aneurysm characteristics, device and procedural details, and functional outcomes. Results: A total of 64 aneurysms were included in our study. Fifteen patients (24.1%) presented with acutely ruptured aneurysm while the rest were unruptured. The majority of patients (82.8%) required only one attempt for successful device deployment, while a stent was necessary as an adjunct treatment in 4 patients (6.3%) due to WEB herniation. Two patients had residual aneurysm that had to undergo additional treatment; one of them underwent second WEB embolization and one underwent clip ligation. One patient with a PICA aneurysm had device dislodgment with injury to the parent vessel—Onyx and coils were used to deconstruct the vertebral artery. Conclusions: The advent of the WEB device has significantly impacted the surgical decision-making for the treatment of bifurcation, wide-neck aneurysms. We discuss in detail the lessons learned from patient selection, device size selection, technique, and complications from two institutions with high-volume endovascular and microsurgical aneurysm treatment experience.

Early Lessons Learned From the WEB Device: Feasibility, Technique and Complications—A Real-Life Experience

Abstract INTRODUCTION Wide-neck bifurcation cerebral aneurysms have always posed a treatment challenge and have historically required either clip ligation, or stent vs balloon-assisted coil embolization. This predicament led to the development of the newly FDA-approved Woven EndoBridge (WEB) Aneurysm Embolization System (Sequent Medical Inc, Aliso Viejo, California), which is a self-expanding mesh that achieves intrasaccular flow disruption and does not require antithrombotic medications. In this study, we report our experience with the first 29 consecutive aneurysms treated via WEB embolization at 2 high-volume institutions. METHODS We reviewed our first 27 consecutive patients with 29 cerebral aneurysms who underwent WEB embolization from February to April 2019. We collected data on patient demographics and clinical presentation, aneurysm characteristics, device and procedural details, and functional outcomes. RESULTS A total of 29 aneurysms were included in our study. Seven patients (24.1%) presented with acutely ruptured aneurysm while the rest were unruptured. The majority of patients (82.8%) required only 1 attempt for successful device deployment, while a stent was necessary as an adjunct treatment in 4 patients (13.7%) due to WEB herniation. Two patients had residual aneurysm that had to undergo additional treatment; one of them underwent second WEB embolization and one underwent clip ligation. One patient with a PICA aneurysm had device dislodgment with injury to the parent vessel Onyx and coils were used to deconstruct the vertebral artery. CONCLUSION The advent of the WEB device has significantly impacted the surgical decision-making for the treatment of bifurcation, wide-neck aneurysms. We discuss in detail the lessons learned from patient selection, device size selection, technique, and complications from 2 institutions with a high-volume endovascular and microsurgical aneurysm treatment experience.

Change in the angle of the anterior genu is associated with occlusion rate after Pipeline flow diversion.

The Pipeline embolization device (PED) is a self-expanding mesh stent that diverts blood flow away from an aneurysm; it has been successfully used to treat aneurysms of the proximal internal carotid artery (ICA). PEDs have a remarkable ability to alter regional blood flow along the tortuous segments of the ICA and were incidentally found to alter the angle of the anterior genu after treatment. The authors quantified these changes and explored their implications as they relate to treatment effect. The authors retrospectively reviewed cases of aneurysms treated with a PED between the ophthalmic and posterior communicating arteries from 2012 through 2015. The angles of the anterior genu were measured on the lateral projections of cerebral angiograms obtained before and after treatment with a PED. The angles of the anterior genu of patients without aneurysms were used as normal controls. Thirty-eight patients were identified who had been treated with a PED; 34 (89.5%) had complete obliteration and 4 (10.5%) had persistence of their aneurysm at last follow-up (mean 11.3 months). After treatment, 32 patients had an increase, 3 had a decrease, and 3 had no change in the angle of the anterior genu. The average measured angle of the anterior genu was 36.7° before treatment and 44.3° after treatment (p < 0.0001). The average angle of the anterior genu of control patients was 43.32° (vs 36.7° for the preoperative angle in the patients with aneurysms, p < 0.057). The average change in the angle of patients with postoperative Raymond scores of 1 was 9.10°, as compared with 1.25° in patients with postoperative Raymond scores > 1 (p < 0.001). Treatment with a PED significantly changes the angle of the anterior genu. An average change of 9.1° was associated with complete obliteration of treated aneurysms. These findings have important implications for the treatment and management of cerebral aneurysm.

Invited commentary

Invited commentary