Cassius Iyad Ochoa Chaar, MD, MS, RPVI

Assistant Professor of Surgery (Vascular)

Research Departments & Organizations

Surgery: Vascular & Endovascular Surgery

Office of Cooperative Research

Research Interests

Aortic Aneurysm; Thrombolytic Therapy; Varicose Veins; Vascular Diseases; Vascular Surgical Procedures; Venous Thrombosis

Research Summary

Dr Chaar’s research focuses on clinical outcomes using large national database analysis such as the ACS-NSQIP and the NIS. He also leads multiple clinical trials at Yale New Haven Hospital. He studies and publishes on various aspects of vascular disease including peripheral artery disease, varicose veins, venous thromboembolism, and aortic aneurysms. The work of his research team is regularly presented in several regional and national vascular societies scientific meetings including the New England Society of Vascular Surgery (NESVS), the Eastern Vascular Society (EVS), the Vascular and Endovascular Surgery Society (VESS), the American Venous Forum (AVF), the Society of Clinical Vascular Surgery (SCVS), and the Society of Vascular Surgery (SVS).

Dr. Chaar has mentored several trainees in conducting research projects and helped them prepare and present their work at national meetings. He formulates a research project in vascular disease based on the student's interests and the knowledge gap in the literature. His philosophy in research relies on engaging the trainees and making sure they are genuinely interested in the questions they are trying to answer. "That is the key to success", states Dr. Chaar. As such the trainees can chose between a retrospective study based on clinical work done at Yale, a database analysis based on the ACS-NSQIP or NIS, or even can design a small prospective study to examine specific treatments or outcomes of interest. Last, there are always opportunities to write and publish case reports of patients treated nontraditionally.

Extensive Research Description

                                                        Research Projects for Students and Residents

Project 1:

Title: The significance of reinterventions in the treatment of peripheral artery disease (PAD)

Description: Patients treated with open or endovascular revascularization of the lower extremities undergo frequently repeated intervention to sustain patency and to provide limb salvage in patients with critical limb ischemia. This project studies the impact and costs of reinterventions on patient outcomes.

Project 2:

Title: Management of vascular disease in the very old

Description: As the population ages, vascular surgeons increasingly face complex patients in their 80s and 90s requiring treatment. This project aims to study the trends in treatment of vascular disease in the elderly, as well as the outcomes and focus on the impact on quality of life.

Project 3:

Title: Effect of loco/regional anesthesia on outcomes of vascular surgery

Description:  Advances in anesthesia technique as well as the introduction of longer acting local anesthetics allows vascular surgery specially hybrid procedures to be effectively performed on patients while minimizing pain in the perioperative period. This project studies the impact of these anesthesia techniques on patient outcome and satisfaction.

Project 4:

Title: Universal Algorithm for venous disease

Description: Our understanding of venous disease and its treatment has evolved and there are several structural anomalies that can be surgically treated that can improve patient symptoms. However, there is no recommended and well defined protocol for the approach to the patient. This project studies the effect of the Yale Vascular Surgery protocol on the evaluation and outcomes of patients with venous disease affecting the lower extremities.

Project 5:

Title: Iliofemoral DVT and post phlebetic syndrome in the DOAC era

Description: This study aims to study the risk of postphlebetic syndrome after iliofemoral DVT in patients on DOAC compared to coumadin

Project 6:

Title: Inferior vena cava position and its relation to complications

Description: IVC filters are still commonly inserted and carry long-term risks of complications. The ideal position for IVC filters is still controversial. This study examines the position of the filters in the cava and correlates it with possible complications.

Project 7:

Title: Predictors of success after stenting iliac vein compression

Description: Iliac vein compression remains a challenging condition to diagnose as there is a good percentage of asymptomatic patients that are found incidentally to have compression of the iliac veins. This study examines the predictors of success after iliac vein stenting in order to enhance patient selection and optimize outcomes.

Project 8:

Title: Smoking cessation in vascular patients

Description: Smoking is very prevalent in patients with vascular disease. Patients get advised about smoking cessation all the time. This study looks at different means to enhance cessation in vascular patients in the inpatient as well as the outpattient settings.

Clinical Trials

Conditions Study Title
Diseases of the Cardiovascular System ANCHOR (Aneurysm Treatment Using the Heli-FX Aortic Securement System Global Registry) (ANCHOR)
Diseases of the Cardiovascular System Predicting the Safety and Effectiveness of Inferior Vena Cava Filters (PRESERVE)

Selected Publications

See list of PubMed publications

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Contact Info

Cassius Iyad Ochoa Chaar, MD, MS, RPVI
Office Location
Yale Vascular SurgeryBoardman Building
330 Cedar Street

New Haven, CT 06510
Mailing Address
Vascular & Endovascular Surgery330 Cedar Street - Boardman Building 204
PO Box 208062

New Haven, CT 06520-8062

Curriculum Vitae