Team-Based, Multidisciplinary, and Patient-Centric Aneurysm Management at UPMC

At UPMC, surgical care for intracranial aneurysms is structured around precision, collaboration, and an individualized decision-making process that puts the patient and their clinical picture at the center of the process. The program is co-led by Bradley Gross, MD, associate professor of Neurological Surgery, and director of Endovascular Neurosurgery and the Endovascular Neurosurgery Fellowship, and Michael Lang, MD, assistant professor of Neurological Surgery, and director of Cerebrovascular Neurosurgery. Together, Dr. Lang and Dr. Gross oversee one the largest high-volume referral centers for aneurysm care in the United States, and also one of the most productive research programs working to improve outcomes of clinical management and surgical care for these often-complex cerebrovascular conditions.

Dr. Gross and Dr. Lang bring collaborative and complementary expertise in cerebrovascular neurosurgery to treat the full spectrum of brain aneurysms and co-manage many of the most complex patients together. This close partnership, built during the last six years working together, has created a model of care in which every patient receives the benefit of a real-time second opinion, access to the full range of procedural options, and a customized treatment plan. The integrated clinical infrastructure of aneurysm management and research at UPMC is built upon shared operating teams, fellows, technologists, and nursing staff which ensures consistent delivery of care in all cases but is of particular benefit to those with high degrees of clinical complexity.

Rather than adopting a one-size-fits-all approach to clinical decision making and procedural intervention, the team is focused on identifying when to treat patients operatively and, equally if not more important, when not to treat an unruptured aneurysm.

"We strive to do an excellent job at identifying which aneurysms need to be treated and which do not," says Dr. Gross. “One, if not the most, important decision we make with our patients is actually not to do anything but to observe and monitor, avoiding overtreatment in cases that present with a low risk of rupture.”

When to Treat and When to Watch: Patient Selection, Risk Stratification, and Avoiding Overtreatment

The majority of aneurysms in individuals are unruptured and discovered incidentally during imaging for unrelated health issues. This clinical scenario, common to aneurysms in general, has led to increased scrutiny in the field about the risks of overtreating patients. At UPMC, determining whether an aneurysm requires intervention is a highly structured process that considers the natural history of the patient’s lesion and their unique clinical and anatomic profile.

“We try to separate the concept of identifying an aneurysm from the assumption that it needs to be treated,” Dr. Gross says.

The team conducts comprehensive reviews of each case, incorporating established risk stratification tools, as well as additional evidence-based factors that have been shown to affect rupture risk and treatment safety. These characteristics include:

• Aneurysm size and location.
• Morphology (e.g., the presence of daughter sacs).
• Patient age.
• Smoking status.
• Family history of aneurysmal rupture.
• Other comorbidities or patient-specific factors like goals of care.

“Aneurysms in certain locations, such as the posterior circulation or anterior communicating artery, carry a higher risk of rupture even when small. Others, like in the cavernous internal carotid artery, tend to be more benign,” says Dr. Lang. “When necessary, we employ high-resolution vessel imaging to assess the morphology and dynamic behavior of complex aneurysms to determine if, and how, they need to be treated.”

The approach used by Dr. Lang and Dr. Gross guiding these kinds of assessments is conservative and patient centered. With access to, and expertise in the full spectrum of surgical and endovascular options, there is no procedural bias at UPMC when it comes to treating aneurysms. Instead, the focus is on long-term durability and safety for the patient.

“Our goal is to give every patient a treatment or surveillance plan that we would choose for ourselves or our families,” Dr. Gross says. “It’s much less about favoring coiling or clipping and more about what will benefit the individual in front of us the most.”

When observation of an aneurysm is the recommended clinical path, it is not a passive approach to care. Patients are enrolled in a structured follow-up program with periodic imaging that looks for aneurysm growth or morphological changes that might trigger a clinical shift or decision toward surgical intervention.

“We are always available and open to reassessment should a patient’s clinical status or preferences evolve over time,” Dr. Lang says. “What we’re talking about is a dynamic decision-making process that changes if, and as, the patient changes.”

Therapeutic Options Matched to the Right Patient

When a decision is made to treat an aneurysm, the choice of therapeutic approach taken by Drs. Lang and Gross is driven by anatomical characteristics, patient-specific risk factors, and long-term management considerations. The overall approach maintains a treatment-neutral stance, with every modality at their disposal.

“We don’t have a default pathway for patients,” says Dr. Gross. “Each plan is built around achieving the safest and most durable outcome.”

For saccular aneurysms with narrow necks, coiling is a common approach. It is favored for its relative simplicity and safety profile, particularly in the setting of a rupture, where rapid occlusion without brain manipulation is ideal. When aneurysm morphology makes standard coiling impossible or too difficult, other endovascular options are used, including balloon-assisted and stent-assisted coiling, as well as intrasaccular devices. 

These are selected to minimize the risk of coil herniation and to avoid covering branch vessels in the case of bifurcation aneurysms.

For unruptured aneurysms along sidewall segments of the internal carotid or vertebrobasilar arteries, flow diversion offers a highly durable treatment by reconstructing the parent vessel and redirecting flow away from the aneurysm sac. However, this technique requires that patients tolerate dual antiplatelet therapy and is not suitable for bifurcation aneurysms or in the setting of rupture, with selected exceptions.

“When we’re considering flow diversion, we’re thinking about anatomy, but we’re also thinking about the patient’s ability to be on antiplatelet therapy, the long-term healing process, and what our retreatment options would be if the device does not work as planned,” says Dr. Lang.

Microsurgical clipping is selected for aneurysms in locations like the middle cerebral artery, or those with complex branch patterns that make endovascular access problematic. Clipping is also considered in younger patients seeking long-term durability without the need for imaging surveillance or long-term medication use. Minimally invasive craniotomy techniques are used to reduce operative morbidity and facilitate recovery.

“We’re not just choosing the safest option in the moment,” says Dr. Gross. “We’re matching the treatment to the aneurysm, to the patient’s lifestyle, and to their long-term goals of care.”

This individualized matching of technique to anatomy and patient profile is the foundation of UPMC’s aneurysm care. Every decision is made with a focus on long-term success, minimizing the need or potential for retreatment, and preserving options for future care should an aneurysm return, or a new one develops.

“We try to avoid putting patients in a position where one treatment today limits our ability to retreat or reintervene in the future,” says Dr. Lang.

Combined, Hybrid, and Staged Interventions Expand the Clinical Options for Patients

For aneurysms that present clinical challenges for conventional interventions, including fusiform, giant, thrombotic, or branch-incorporating aneurysms, advanced revascularization and hybrid procedures may be employed.

Dr. Lang performs a high volume of bypass procedures for complex aneurysms, including extracranial-to-intracranial (EC-IC) and intracranial-to-intracranial (IC-IC) techniques. His practice includes superficial temporal artery-middle cerebral artery (STA-MCA) bypasses, high-flow grafts, and vessel reimplantation strategies with consistently high patency and low complication rates.

These techniques allow the team to trap or occlude an aneurysm and preserve blood flow. For example, in cases where a fusiform aneurysm involves a major trunk or when flow diversion is not safe or effective, bypass may be used to reroute circulation and safely exclude the aneurysm.

“In cases where the aneurysm incorporates eloquent branches and cannot be clipped or treated endovascularly without sacrificing flow, bypass is the only option that offers a cure and preservation of function,” says Dr. Lang.

Dr. Lang has pioneered combined procedures in which a bypass is performed first, followed by an endovascular occlusion or flow diversion. This kind of multi-step approach expands the types of aneurysms that can be successfully treated. These combined procedures are chosen to isolate the benefits of each component while minimizing the risks associated with pure microsurgical or endovascular opportunities. These combined techniques have been used to treat aneurysms otherwise deemed incurable.

“We used to treat some of these most demanding aneurysms with techniques such as hypothermic cardiac arrest. But now we’re able to tackle these challenges through a two-step approach that is less taxing on the patient,” says Dr. Lang.

Patients undergoing these procedures benefit from the team-based, multidisciplinary approach of the aneurysm program at UPMC that combines neurosurgery, neuro-intervention, neurocritical care, and advanced imaging support, making it one of the few centers nationally able to offer this level of surgical care with a high level of consistency and good outcomes.

“Our ability to offer these types of hybrid interventions for our patients reflects our program’s expertise and commitment to getting durable, safe, and personalized care, and in particular for patients who were previously told there were no viable treatment options for their aneurysm,” says Dr. Lang.

Management of Ruptured Aneurysms

In the acute setting of a ruptured cerebral aneurysm, Dr. Gross and Dr. Lang prioritize rapid stabilization, early diagnosis, and timely triage to endovascular therapy.

“In the ruptured setting, we tend to favor endovascular coiling-based approaches even though they’re less durable because of the speed and safety profile they afford,” says Dr. Gross.

If initial treatment is not fully durable, it is tailored to be safely followed by delayed definitive therapy, such as flow diversion or clipping, once the patient has stabilized and the team has a more complete clinical picture at their disposal.

Likewise, some ruptured aneurysms are still treated with primary clipping procedures when this is deemed safest for the patient. Dr. Lang and Dr. Gross coordinate closely across neurocritical care, neurosurgery, and endovascular disciplines to manage complications and optimize recovery for patients who experience an acute rupture.

Post-Treatment Follow Up and Long-Term Monitoring

Surveillance is tailored to the chosen treatment. Coiled aneurysms are followed with angiography at six months and periodically thereafter. In contrast, clipped or successfully flow-diverted aneurysms with complete occlusion may require minimal long-term imaging.

UPMC’s outpatient infrastructure provides centralized support for imaging coordination, medication management, and re-entry into care if needed.

Leadership in Aneurysm Research

UPMC has consistently played a leadership role in advancing aneurysm care through active participation in multicenter trials and investigator-initiated outcomes research. The program was the leading enroller in the ATLAS trial, which evaluated the safety and effectiveness of the Neuroform Atlas stent for stent-assisted coiling of wide-necked intracranial aneurysms. Findings from ATLAS have helped shape national guidelines for the endovascular treatment of both ruptured and unruptured aneurysms.

UPMC continues to participate in ongoing multicenter studies of intrasaccular devices, including the NECC/Contour trial, which is investigating novel intrasaccular implants designed to disrupt intra-aneurysmal flow and promote thrombosis while preserving adjacent branch vessels.

Additionally, the multicenter SEAL-IT trial is examining newer-generation intrasaccular flow diverters designed to improve occlusion rates in anatomically challenging aneurysms and reduce procedural risks.

Beyond device trials, Drs. Gross, Lang, and colleagues have published numerous retrospective and prospective studies comparing microsurgical clipping and flow diversion, focusing on treatment durability, complication rates, and patient-reported outcomes.

Dr. Lang also has contributed significantly to the literature on bypass and hybrid strategies, presenting this work on novel techniques for complex aneurysm repair at national and international neurosurgical forums.

For Referring Physicians – When to Refer a Patient for Aneurysm Consultation

UPMC’s multidisciplinary cerebrovascular team encourages referring physicians to seek consultation for any patient with an intracranial aneurysm, regardless of size, complexity, or treatment history. Early evaluation by a center with comprehensive surgical and endovascular capabilities can help ensure accurate risk assessment, avoid unnecessary interventions, and preserve future treatment options.

“Even when an aneurysm appears stable or low risk, subtle anatomical features can change the recommendation. That is where our combined expertise really makes a difference,” says Dr. Lang.

“Our goal is to give patients clarity and confidence in their plan, even if that means confirming that no treatment is needed. That reassurance can be just as important as the intervention itself,” says Dr. Gross.

Referral is appropriate in the following situations:

• A newly discovered aneurysm, particularly in a patient with multiple comorbidities or with an unclear risk profile.
• Aneurysms that involve branching vessels or present with complex morphology.
• Patients who have had prior treatment failure or recurrence.
• Cases where previous providers have deemed the aneurysm inoperable or untreatable.

In all cases, the goal is to collaborate in patient care to achieve optimal results. Patients referred to UPMC for an unruptured aneurysm receive individualized counseling, and comprehensive recommendations are shared with the referring provider. If treatment is indicated, referring physicians remain integral partners throughout the process.

“Our program is designed to extend the capabilities of the broader community. We want our colleagues to feel confident that when they send a patient here, they are getting options and expertise that may not be available elsewhere,” says Dr. Lang.

Referrals and Consultations

To refer a patient for consultation, please call 412-647-3658 or use the department’s online contact form.

References and Further Reading

Below is a selection of published research on cerebral aneurysm from Drs. Gross, Lang and colleagues at UPMC.

Hoz SS, Ma L, Agarwal P, Jacobs RC, Al-Bayati AR, Nogueira RG, Zenonos GA, Gardner PA, Friedlander RM, Lang MJ, Gross BA. Clinical Comparison of Flow Diversion and Microsurgery for Retreatment of Intracranial Aneurysms. J Clin Neurosci. 2025; 136: 111296.

Ma L, Hoz SS, Al-Bayati AR, Nogueira RG, Lang MJ, Gross BA. Flow Diverters With Surface Modification in Patients With Intracranial Aneurysms: A Systematic Review and Meta-Analysis.  World Neurosurg. 2024 185: 320-326.

Belkhir JR, Pease M, McCarthy DJ, Legarretta A, Mittal AM, Crago EA, Gross BA, Lang MJ. Subarachnoid Hemorrhage Outcomes in an Endovascular Right of First Refusal Neurosurgical Environment. World Neurosurg. 2024; 181: e524-e532.

Kim S, Nowicki KW, Kohyama K, Mittal A, Ye S, Wang K, Fujii T, Rajesh S, Cao C, Mantena R, Barbuto M, Jung Y, Gross BA, Friedlander RM, Wagner WR. Development of an Injectable, ECM-Derivative Embolic for the Treatment of Cerebral Saccular Aneurysms. Biomacromolecules. 2024; 25(8): 4879-4890.

Hoz SS, Hudson JS, Ma L, Lang MJ, Gross BA. Medications and “Risk” of Aneurysm Rupture Based on Presentation: Setting the Record Straight. World Neurosurg. 2024; 188: e573-577.

Hoz SS, Ma L, Muthana A, Al-Zaidy MF, Ahmed FO, Ismail M, Jacobs RC, Agarwal P, Al-Bayati AR, Nogueira RG, Lang MJ, Gross BA. Cranial Nerve Palsies and Intracranial Aneurysms: A Narrative Review of Patterns and Outcomes. Surg Neurol Int. 2024;15: 277.

Ma L, Hoz SS, Al-Bayati AR, Nogueira RG, Lang MJ, Gross BA. Sustained Efficacy of Angioplasty for Cerebral Vasospasm After Aneurysmal Subarachnoid Hemorrhage: Risk Features and Device Comparison. J Clin Neurosci. 2024; 128: 110784.

Ma L, Hoz SS, Al-Bayati AR, Nogueira RG, Lang MJ, Gross BA. Improved Outcomes Among Octogenarians With Ruptured Aneurysms: Endovascular Treatment as Right of First Refusal in the 2^nd Post-Trial Decade. World Neurosurg. 2024; 190: e883-890.

Hudson JS, McCarthy DJ, Alattar A, Mehdi Z, Lang MJ, Gardner PA, Zenonos GA, Friedlander RM, Gross BA. Increased Prevalence of Blister Aneurysm Formation During the COVID-19 Pandemic.  Clin Neurol Neurosurg. 2023; 226: 107613.

Mittal AM, Pease M, McCarthy D, Legarretta A, Belkhir R, Crago EA, Lang MJ, Gross BA. Hunt-Hess Score at 48 Hours Improves Prognostication in Grade 5 Aneurysmal Subarachnoid Hemorrhage.  World Neurosurg. 2023; 171: e874-e878.

Bata A, Al Qudah A, Algarni S, Al Ta’ani O, Balzer JR, Crammond DJ, Shandal V, Gross BA, Lang MJ, Anetakis KM, Narayanan S, Mina A, Thirumala PD. Diagnostic Accuracy of Somatosensory Evoked Potentials and EEG During Endovascular Treatment of Unruptured Cerebral Aneurysms. World Neurosurg. 2023; 177: e513-522.

Jankowitz BT, Jadhav AP, Gross B, et al. Pivotal Trial of the Neuroform Atlas Stent for Treatment of Posterior Circulation Aneurysms: One-Year Outcomes. J Neurointerv Surg. 2022; 14: 143-148.

Hudson JS, Lang MJ, Gross BA. Novel Innovation in Flow Diversion: Surface Modifications.  Neurosurg Clin N Am. 2022; 33: 215-218.

Gross BA, Ares WJ, Ducruet AF, Jadhav AP, Jovin TG, Jankowitz BT. A Clinical Comparison of Atlas and LVIS Jr Stent-assisted Aneurysm Coiling. J Neurointerv Surg. 11: 171-174, 2019.

Tonetti DA, Jankowitz BT, Gross BA. Antiplatelet Therapy in Flow Diversion. Neurosurgery. 2020; 86(Suppl 1): S47-52.