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Kelly, Michael

https://orcid.org/0000-0002-3278-2620

Mayo Clinic

LGDA Alliance, Saint Petersburg, Florida, USA

Citations 6

Sirolimus for Venous Malformations: A Systematic Review of Efficacy and Safety
Teng, Joyce , Martini, Jeffrey, Tollefson, Megha M. , Martini, Jeff , Kelly, Michael , Greer, Alexander

Lymphatic Research and Biology | October 7, 2025 | Volume: 23 | Issue: 6 | Pages: 311-319

10.1177/15578585251377562 Get It

Background: Venous malformations can cause substantial morbidity and long-term complications. There are no Food and Drug Administration (FDA)-approved therapies for the treatment of venous malformations. However, off-label use of sirolimus has demonstrated clinical benefit in these patients. This systematic review evaluates the efficacy and safety of sirolimus in the management of venous malformations. Methods and Results: A systematic literature search identified 26 studies comprising 98 patients treated with sirolimus for venous malformations. Most studies were case reports or case series (77%), with 15% prospective trials and 8% retrospective analyses. Sirolimus, primarily administered orally, yielded some level of clinical improvement in 72% of reported patients, with consistent symptomatic relief observed in coagulopathy, bleeding, anemia, pain, and improved function. However, reduction in the size of the malformation varied and treatment-limiting side effects were observed. Conclusions: Oral sirolimus is a promising treatment option for venous malformations, especially for those with deep venous malformations. A direct, targeted topical treatment could provide clinical benefit for the cutaneous manifestation without the risk of off-target effects as occur with oral sirolimus. Further prospective, controlled studies are warranted to elucidate sirolimus’s role in managing venous malformations.
Response to sirolimus in capillary lymphatic venous malformations and associated syndromes: Impact on symptomatology, quality of life, and radiographic response
Engel, Elissa , Hammill, Adrienne M. , Adams, Denise M. , Phillips, Roderic J. , Jeng, Michael , Tollefson, Megha M. , Iacobas, Ionela , Schiff, Deborah , Greenberger, Shoshana , Frieden, Ilona J. , Zaghloul, Nibal, Drolet, Beth A. , Geddis, Amy E., Engel, Elissa R , Hammill, Adrienne , Ricci, Kiersten , Jeng, Michael , Kelly, Michael , Goldenberg, Dov Charles

Pediatric Blood & Cancer | January 18, 2023 | Volume: 70 | Issue: 4 | Pages: No page available

10.1002/pbc.30215 Get It

Abstract Background Capillary lymphatic venous malformations (CLVM) and associated syndromes, including Klippel–Trenaunay syndrome (KTS) and congenital lipomatous overgrowth, vascular malformation, epidermal nevi, skeletal, and spinal syndrome (CLOVES), are underrecognized disorders associated with high morbidity from chronic pain, recurrent infections, bleeding, and clotting complications. The rarity of these disorders and heterogeneity of clinical presentations make large‐scale randomized clinical drug trials challenging. Identification of PIK3CA (phosphatidylinositol‐4,5‐bisphosphate 3‐kinase catalytic subunit alpha [gene]) mutations in CLVM has made targeted medications, such as sirolimus, attractive treatment options. The aim of this study was to investigate the safety and efficacy of sirolimus therapy in CLVM. Procedure A combined prospective and retrospective cohort of pediatric and young adult patients with CLVM treated with sirolimus was evaluated for disease response, including symptom improvement, quality of life (QOL), and radiologic response. Sirolimus dosing regimens and toxicities were also assessed. Results Twenty‐nine patients with CLVM, including KTS and CLOVES, were included. Ninety‐three percent of patients reported improved QOL, and 86% had improvement in at least one symptom. Most significantly, improvement was noted in 100% of patients with bleeding and 89% with thrombotic complications with corresponding decreases in mean D‐dimer ( p = .008) and increases in mean fibrinogen ( p = .016). No patients had progressive disease on sirolimus. Most common side effects included neutropenia, lymphopenia, infection, and aphthous ulcers/stomatitis. No toxicities were life‐threatening, and none required long‐term discontinuation of sirolimus. Conclusion Sirolimus appears to be effective at reducing complications and improving QOL in patients with CLVM and associated syndromes. In this patient cohort, sirolimus was well tolerated and resulted in few treatment‐related toxicities.
Abstract W MP34: Safety and Efficacy of Hydrosoft Coils in the Treatment of the Aneurysm Neck: Preliminary Results From the GEL THE NEC Registry
Brinjikji, Waleed , Connelly, Beth B, Tubman, D, Jensen, Mary E. , Chaudry, I, Kallmes, David F. , Hoh, Brian L. , Kelly, Michael , Jabbour, Pascal , Hui, Ferdinand

Stroke | March 20, 2022 | Volume: 45 | Issue: suppl_1 | Pages: No page available

10.1161/str.45.suppl_1.wmp34 Get It

Background and Purpose: The HydroSoft coil was developed to be placed along the aneurysm neck to enhance intracranial aneurysm healing. In order to better understand the safety and efficacy of Hydrosoft coils in treating the aneurysm neck, the GEL THE NEC multicenter registry was developed. We report immediate angiographic and clinical results of this prospective registry. Methods: The GEL THE NEC study was undertaken at 30 centers in 5 countries. Patients aged 21-90 years with a ruptured or unruptured aneurysm 3-15 mm in size were eligible for enrollment. For each patient the following data were obtained: demographics and comorbidities, aneurysm geometry, use of adjunctive devices, immediate angiographic outcomes, and early (<30 days) adverse events. Postoperative anatomic results were graded by on-site neuroradiologists using the Modified Raymond Scale (Raymond 1=complete obliteration of aneurysm including the neck, Raymond 2=contrast filling the neck of the aneurysm without opacification of the aneurysm sac, Raymond 3=contrast filling the sac of the aneurysm). Predictors of good angiographic outcome were studied using chi-squared and t-tests. Results: A total of 571 patients with 571 aneurysms have been treated thus far in the study (196 ruptured, 375 unruptured). HydroSoft coils were successfully deployed in 549 (96.3%) of these patients. Adjunctive devices were used in 307 cases (53.8%) (212 balloon assistance, 89 stent). Aneurysmal occlusion rates were the following: 261 patients (47.3%) exhibited Raymond 1 occlusion, 257 patients (47.0%) had Raymond 2, and 29 patients (5.3%) had Raymond 3. Early post-operative stroke occurred in 10 patients (1.8%). Aneurysm perforation occurred in 11 patients (1.9%). Coil prolapse/migration occurred in 8 patients (1.4%). Early post-operative death occurred in 3 patients, all of whom presented with SAH (0.5%). Small aneurysm neck size was a significant predictor of good angiographic outcome (P=0.0003). Conclusions: Endovascular treatment of intracranial aneurysms with HydroSoft coils resulted in high rates of satisfactory occlusion (94.3%) and low rates of major clinical complications. Aneurysm neck size was a significant predictor of angiographic outcomes.
The Hydrogel Endovascular Aneurysm Treatment Trial (HEAT): A Randomized Controlled Trial of the Second-Generation Hydrogel Coil
Bendok, Bernard R. , Abi-Aad, Karl R., Ward, Jennifer , Kniss, Jason F , Kwasny, Mary , Rahme, Rudy J. , Aoun, Salah G. , Tecle, Najib E. El , Zammar, Samer G. , Aoun, Rami James N. , Patra, Devi Prasad, Raymond, Jean , Woo, Henry H. , Dabus, Guilherme , Milot, Geneviève , Scott, John A. , DeNardo, Andrew , Investigators, HEAT Study, Lavine, Sean D., Bozorgchami, Hormozd, Veznedaroglu, Erol, Albuquerque, Felipe C. , Fiorella, David, Boulos, Alan S. , Cortes, Maria, Kanaan, Hilal, Jindal, Gaurav , Klucznik, Richard , Kalmes, David, Xavier, Andrew, Hussain, Muhammad , Moran, Christopher J. , Adel, Brian van , Milot, Genevieve, Hirsch, Joshua A , Carpenter, Jeffrey , Powers, Ciarán J. , Luh, George, Tummala, Ramanchandra, Evans, Avery J. , Garg, Ankur, James, Roberts, Sauvageau, Eric , Fields, Jeremy D. , Grobelny, Thomas, Hartman, J., Patra, Devi P. , Bendok, Bernard R , Ward, Jennifer D, Ahmadieh, Tarek Y. El , Ansari, Sameer A. , Fiorella, David , Dabus, Guilherme C. , Almandoz, Josser E Delgado , Dashti, Shervin R , Investigators, HEAT Study, Deshaies, Eric Michael , Fiorella, David, Tawk, Rabih G. , Romero, Charles, Kelly, Michael , Chaudry, Imran , Pandey, Aditya S , Wang, Dennis Y.Q. , Milot, Genevieve, Jabbour, Pascal , Shankar, Jai , Patsalides, Athos T , Lee, Sung , James, Robert F. , Jayaraman, Mahesh V. , Satti, Sudhakar R

Neurosurgery | February 10, 2020 | Volume: 86 | Issue: 5 | Pages: 615-624

10.1093/neuros/nyaa006 Get It

Abstract BACKGROUND Aneurysm recurrence after coiling has been associated with aneurysm growth, (re)hemorrhage, and a greater need for follow-up. The second-generation HydroCoil Embolic System (HES; MicroVention, Inc) consists of a platinum core with integrated hydrogel and was developed to reduce recurrence through enhancing packing density and healing within the aneurysm. OBJECTIVE To compare recurrence between the second-generation HES and bare platinum coil (BPC) in the new-generation Hydrogel Endovascular Aneurysm Treatment Trial (HEAT). METHODS HEAT is a randomized, controlled trial that enrolled subjects with ruptured or unruptured 3- to 14-mm intracranial aneurysms amenable to coiling. The primary endpoint was aneurysm recurrence using the Raymond-Roy scale. Secondary endpoints included minor and major recurrence, packing density, adverse events related to the procedure and/or device, mortality, initial complete occlusion, aneurysm retreatment, hemorrhage from target aneurysm during follow-up, aneurysm occlusion stability, and clinical outcome at final follow-up. RESULTS A total of 600 patients were randomized (HES, n = 297 and BPC, n = 303), including 28% with ruptured aneurysms. Recurrence occurred in 11 (4.4%) subjects in the HES arm and 44 (15.4%) subjects in the BPC arm ( P = .002). While the initial occlusion rate was higher with BPC, the packing density and both major and minor recurrence rates were in favor of HES. Secondary endpoints including adverse events, retreatment, hemorrhage, mortality, and clinical outcome did not differ between arms. CONCLUSION Coiling of small-to-medium aneurysms with second-generation HES resulted in less recurrence when compared to BPC, without increased harm. These data further support the use of the second-generation HES for the embolization of intracranial aneurysms. Video Abstract
GEL THE NEC: a prospective registry evaluating the safety, ease of use, and efficacy of the HydroSoft coil as a finishing device
Brinjikji, Waleed , Amar, Arun Paul , Almandoz, Josser E Delgado , Díaz, Orlando , Jabbour, Pascal , Kelly, Michael , Layton, Kennith D, Miller, Jeffrey W. , Levy, Elad, Moran, Christopher J. , Woo, Henry H. , Sellar, Robin, Ho, Brian , Evans, Avery J. , Kallmes, David F. , Suh, Dae C , Jabbour, Pascal , Hanel, Ricardó A. , Hui, Ferdinand , Levy, E, Ho, Brian, Miller, Jeffrey

Journal of NeuroInterventional Surgery | January 30, 2017 | Volume: 10 | Issue: 1 | Pages: 83-87

10.1136/neurintsurg-2016-012915 Get It

Background and purpose The HydroSoft coil was developed as a finishing coil, ideally to be placed along the aneurysm neck to enhance intracranial aneurysm healing. The GEL THE NEC (Gaining Efficacy Long Term: Hydrosoft, an Emerging, New, Embolic Coil) multicenter registry was developed to assess the safety and efficacy of HydroSoft coils in treating intracranial aneurysms. We report angiographic and clinical results of this prospective registry. Materials and methods GEL THE NEC was performed at 27 centers in five countries. Patients aged 21–90 years with a ruptured or unruptured aneurysm 3–15 mm in size were eligible for enrollment. The following variables were obtained: demographics/comorbidities, aneurysm geometry, adjunctive devices used, proportion of patients in whom HydroSoft coils were successfully placed, and long-term angiographic outcomes (graded by an independent core laboratory using the Modified Raymond Scale), and procedure-related adverse events. Predictors of good angiographic outcome were studied using χ2 and t-tests. Results A total of 599 patients with 599 aneurysms were included in this study. HydroSoft coils were successfully deployed in 577 (96.4%) patients. Procedure-related major morbidity and mortality were 0.5% (3/599) and 1.3% (8/599), respectively. The most common perioperative complications were iatrogenic vasospasm (30/599, 5.0%), thromboemboli (27/599, 4.5%), and aneurysm perforation (16/599, 2.7%). At last angiographic follow-up (mean 9.0±6.3 months), the complete occlusion rate was 63.2% (280/442) and near complete occlusion rate was 25.2% (107/442). The core laboratory read recanalization rate was 10.8% (46/425) and the retreatment rate was 3.4% (20/599). Conclusions Endovascular treatment of intracranial aneurysms with HydroSoft coils resulted in complete/near complete occlusion rates of 88% and a major complication rate of 1.8%. Trial registration number NCT01000675.
Histopathological findings following pipeline embolization in a human cerebral aneurysm at the basilar tip
Kelly, Michael , Kadirvel, Ramanathan , Kallmes, David F. , Dai, Daying , Kallmes, David, Ding, Yonghong

Interventional Neuroradiology | February 3, 2016 | Volume: 22 | Issue: 2 | Pages: 153-157

10.1177/1591019915622165 Get It

We report histopathological findings from a human cerebral aneurysm following treatment with a flow diverter. A 75-year-old male underwent flow diversion treatment (Pipeline Embolization Device (PED)) and coil embolization for treatment of an aneurysm at the basilar tip. At four months, angiography showed complete aneurysm occlusion; at 12 months angiography demonstrated that the aneurysm had reopened. The patient expired from brainstem compression. The aneurysm cavity was primarily filled with unorganized thrombus. Thick, interrupted neointima crossed the neck interface indicating blood flow into aneurysm through small channels. Along the parent artery the PED was covered by neointima having a measured thickness of 0.19 ± 0.01 mm; the maximal stenosis of the proximal parent artery was 27%. The perforating arteries that were crossed by the PED remained patent. Findings in this human case are similar to those in the elastase-induced aneurysms in rabbits.